Eva Luna: Writing as History

Directory of Open Access Journals (Sweden)

Lynne Diamond-Nigh

1995-01-01

Full Text Available The Bildungsroman of Eva Luna's development as a writer reflects—in a somewhat fragmented manner—important developments in Latin American literary history. Her personal quest was paralleled by an aesthetic quest, manifested in the trying on and taking off of various genres, literary movements and myths characteristic of Latin America; she even goes so far as to allude explicitly to specific authors and their individual works. Although some of these are simply lightheartedly parodied, others are reworked and reinterpreted in the light of the feminist enterprise of the past twenty-five years. Eva Luna transgresses fundamentally by having an intellectually strong, sexual, nurturing, very feminine protagonist, setting up an initial rupture with the dichotomy so clearly demarcated by Octavio Paz between "the mother and the whore." Four primary categories suggest themselves: myth and the mythic consciousness; magical realism; Boom writers; and then a miscellaneous grouping that subsumes a host of other significant literatures and literary themes: the picaresque, the neo-romantic, novels of the dictators, the ever-present conflict between civilization and barbarism, and testimonial literature.

Development of compact synchrotron light source LUNA for x-ray lithography

International Nuclear Information System (INIS)

Takahashi, M.; Mandai, S.; Hoshi, Y.; Kohno, Y.

1992-01-01

A compact synchrotron light source LUNA has been developed by Ishikawajima-Harima Heavy Industries Co., Ltd. (IHI), especially for x-ray lithography. It consists of a 45-MeV linac as an electron injector and an 800-MeV synchrotron. The peak wavelength of synchrotron radiation is around 10 A. The installation of LUNA was completed in April 1989 at the Tsuchiura Facility of IHI. The synchrotron radiation was first observed in December 1989. A stored beam current of 50 mA at 800 MeV and a lifetime over 1 h have been achieved. At present, experiments are still continuing to increase the stored current and the lifetime. X-ray lithography testing is scheduled to begin in a clean room in this facility. This paper describes the outline of LUNA and the present status

Features of the Gravity Probe B Space Vehicle

Science.gov (United States)

Reeve, William; Green, Gaylord

2007-04-01

Space vehicle performance enabled successful relativity data collection throughout the Gravity Probe B mission. Precision pointing and drag-free translation control was maintained using proportional helium micro-thrusters. Electrical power was provided by rigid, double sided solar arrays. The 1.8 kelvin science instrument temperature was maintained using the largest cryogenic liquid helium dewar ever flown in space. The flight software successfully performed autonomous operations and safemode protection. Features of the Gravity Probe B Space Vehicle mechanisms include: 1) sixteen helium micro-thrusters, the first proportional thrusters flown in space, and large-orifice thruster isolation valves, 2) seven precision and high-authority mass trim mechanisms, 3) four non-pyrotechnic, highly reliable solar array deployment and release mechanism sets. Early incremental prototyping was used extensively to reduce spacecraft development risk. All spacecraft systems were redundant and provided multiple failure tolerance in critical systems. Lockheed Martin performed the spacecraft design, systems engineering, hardware and software integration, environmental testing and launch base operations, as well as on-orbit operations support for the Gravity Probe B space science experiment.

X-LUNA: Extending Free/Open Source Real Time Executive for On-Board Space Applications

Science.gov (United States)

Braga, P.; Henriques, L.; Zulianello, M.

2008-08-01

In this paper we present xLuna, a system based on the RTEMS [1] Real-Time Operating System that is able to run on demand a GNU/Linux Operating System [2] as RTEMS' lowest priority task. Linux runs in user-mode and in a different memory partition. This allows running Hard Real-Time tasks and Linux applications on the same system sharing the Hardware resources while keeping a safe isolation and the Real-Time characteristics of RTEMS. Communication between both Systems is possible through a loose coupled mechanism based on message queues. Currently only SPARC LEON2 processor with Memory Management Unit (MMU) is supported. The advantage in having two isolated systems is that non critical components are quickly developed or simply ported reducing time-to-market and budget.

Some future projects in space activities. Centering around utilization of moon and satellite; Uchu kaihatsu no mirai koso ni tsuite. Tsuki/wakusei no riyo wo chushin ni

Energy Technology Data Exchange (ETDEWEB)

Saito, T [Obayashi Corp., Osaka (Japan); Kobayashi, H [Taisei Corp., Tokyo (Japan); Takagi, K [Shimizu Corp., Tokyo (Japan)

1994-09-05

Imagining a space in the middle of the 21st century, a space station installed with the artificial gravity generation facility is constructed, and a space factory utilizing a gravity free environment is also constructed. The construction materials for the space structures of this kind are prepared from the resources of the Luna. A solar power generation satellite being arranged with the solar cells manufactured from a silicon of the Luna is allocated on a geostationary orbit, and a power generated is supplied to the earth by the microwave. In such a time, a regular liner to the Luna and a ferry boat to the Mars will have come to fly, and furthermore an oxygen used for the propellant to them as well will be supplied from the Luna. In order to realize such a conception, there are various problems to be overcome such as a transportation problem first of all, a long life problem in the Luna and Mars bases and so forth. Furthermore a consideration to the environmental conservation of the Luna and Mars is also required. The nature of the Luna without a crustal alteration, meteorological phenomena, and organisms has no force to restore an environmental destruction. As for a space development in the future, it is desired that it should not damage a nature of the space and should be a field to chase a possibility of the human beings for a long time. 30 refs., 14 figs., 1 tab.

LUNA: Status and prospects

Science.gov (United States)

Broggini, C.; Bemmerer, D.; Caciolli, A.; Trezzi, D.

2018-01-01

The essential ingredients of nuclear astrophysics are the thermonuclear reactions which shape the life and death of stars and which are responsible for the synthesis of the chemical elements in the Universe. Deep underground in the Gran Sasso Laboratory the cross sections of the key reactions responsible for the hydrogen burning in stars have been measured with two accelerators of 50 and 400 kV voltage right down to the energies of astrophysical interest. As a matter of fact, the main advantage of the underground laboratory is the reduction of the background. Such a reduction has allowed, for the first time, to measure relevant cross sections at the Gamow energy. The qualifying features of underground nuclear astrophysics are exhaustively reviewed before discussing the current LUNA program which is mainly devoted to the study of the Big-Bang nucleosynthesis and of the synthesis of the light elements in AGB stars and classical novae. The main results obtained during the study of reactions relevant to the Sun are also reviewed and their influence on our understanding of the properties of the neutrino, of the Sun and of the Universe itself is discussed. Finally, the future of LUNA during the next decade is outlined. It will be mainly focused on the study of the nuclear burning stages after hydrogen burning: helium and carbon burning. All this will be accomplished thanks to a new 3.5 MV accelerator able to deliver high current beams of proton, helium and carbon which will start running under Gran Sasso in 2019. In particular, we will discuss the first phase of the scientific case of the 3.5 MV accelerator focused on the study of 12C+12C and of the two reactions which generate free neutrons inside stars: 13C(α,n)16O and 22Ne(α,n)25Mg.

Un asteroide proveniente de la Luna

Science.gov (United States)

Tancredi, G.

El descubrimiento de un débil objeto en movimiento por el telescopio Spacewatch (un instrumento dedicado a la búsqueda de Asteroides Cercanos a la Tierra) en 1991, ha generado una gran controversia en la comunidad planetaria. El objeto, denominado 1991 VG, tiene elementos orbitales llamativamente similares a los de la Tierra, lo que ha llevado a B. G. Marsden a aventurar:``El objeto podría ser una nave espacial en retorno (IAUC 5387)". Luego de analizar las características dinámicas de 1991 VG y las diferentes hipótesis sobre su origen, favorecemos la alternativa de que el objeto es un gran fragmento de material eyectado de la Luna durante un reciente impacto (en las últimas decenas de miles de años). El hallazgo en 1983 en la Antártida de meteoritos con composición tipo lunar, confirma la posibilidad de que material de la superficie del satélite puede ser eyectado a velocidades superiores a la de escape del sistema Tierra-Luna y alcance órbitas heliocéntricas. Los elementos orbitales de 1991 VG corresponden a los valores alcanzados por partículas que apenas escapan de la gravedad lunar y entran en órbitas heliocéntricas a través del punto Lagrangiano exterior del sistema Tierra-Sol.

Twin probes for space geodesy

International Nuclear Information System (INIS)

Bertotti, B.

1978-01-01

The twin probe method, proposed by Bertotti and Colombo (1972) to get rid of nongravitational forces in interplanetary space, can be applied to a near-Earth orbit to eliminate the atmospheric drag. Two equal pairs of probes, each pair consisting of two passive, small and dense spheres of equal surface and different masses, are flown on a circular orbit at an altitude of about 300 km. Each pair determines the motion of an ideal point which feels only the gravitational forces. They are separated by a distance d of (100/200) km and are tracked from a spacecraft or the Space Shuttle, flying at the same altitude. The relative motion of the two ideal points is reconstructed and yields a measurement of the fine structure of the Earth gravitational field, corresponding to a harmonic order l approximately a/d (a is the radius of the Earth). The tracking can be done by laser ranging to the four spheres, covered by corner reflectors; Doppler ranging is more convenient for higher values of l and can also be used. The accuracy in the compensation of the non-gravitational forces and in the measurements one needs for a given l are discussed in detail. (author)

Identity Theft: Gentrification, Latinidad, and American Girl Marisol Luna

Science.gov (United States)

Rudolph, Jennifer Domino

2009-01-01

Released by Mattel in 2005, American Girl doll Marisol Luna quickly provoked controversy. The doll's accompanying narrative depicts her Chicago neighborhood of Pilsen as "dangerous" and recounts her family's move to the suburbs. Pilsen, located just south and west of downtown Chicago, has a long history as a Mexican (im)migrant port of…

Nuclear astrophysics at Gran Sasso Laboratory: the LUNA experiment

Science.gov (United States)

Cavanna, Francesca

2018-05-01

LUNA is an experimental approach for the study of nuclear fusion reactions based on an underground accelerator laboratory. Aim of the experiment is the direct measurement of the cross section of nuclear reactions relevant for stellar and primordial nucleosynthesis. In the following the latest results and the future goals will be presented.

Automatic emissive probe apparatus for accurate plasma and vacuum space potential measurements

Science.gov (United States)

Jianquan, LI; Wenqi, LU; Jun, XU; Fei, GAO; Younian, WANG

2018-02-01

We have developed an automatic emissive probe apparatus based on the improved inflection point method of the emissive probe for accurate measurements of both plasma potential and vacuum space potential. The apparatus consists of a computer controlled data acquisition card, a working circuit composed by a biasing unit and a heating unit, as well as an emissive probe. With the set parameters of the probe scanning bias, the probe heating current and the fitting range, the apparatus can automatically execute the improved inflection point method and give the measured result. The validity of the automatic emissive probe apparatus is demonstrated in a test measurement of vacuum potential distribution between two parallel plates, showing an excellent accuracy of 0.1 V. Plasma potential was also measured, exhibiting high efficiency and convenient use of the apparatus for space potential measurements.

Continuidad y cambio en la organización de los espacios arquitectónicos de Huaca de la Luna y Plataforma A de Galindo, costa norte del Perú

Directory of Open Access Journals (Sweden)

2005-01-01

change in the organization of the architectural spaces of Huaca de la Luna and Platform A of Galindo, northern coast of Peru Abstract: Traditional perspectives concerning the series of events marking the transition between the Early Intermediate Period and the Middle Horizon in the Moche Valley indicate a rapid abandonment of the Huacas del Sol y Luna site, related to the development of the new urban center of Galindo. Archaeological evidence gathered during the last decade indicates a much longer occupation of the Huacas del Sol y Luna site. Moreover, architectural compound of Platform A at Galindo is reminiscent of a public plaza adjacent to Huaca de la Luna. The article examines architectural similarities and differences between these monumental compounds, in the framework of the contemporaneity between the two pre-Hispanic urban centers of the North Coast of Peru.

Eduardo Umaña Luna

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Mario Aguilera Peña

2008-01-01

Full Text Available El maestro Eduardo Umaña Luna será recordado como uno de los connotados exponentes del pensamiento crítico de los académicos de la segunda mitad del siglo xx colombiano. Junto con Orlando Fals Borda fue fundador de la Facultad de Sociología de la Universidad Nacional de Colombia y por muchos años se desempeñó como docente de la Facultad de Derecho y Ciencias Políticas y Sociales, en donde formó varias generaciones de abogados en la necesidad de pensar y aplicar el derecho con un sentido de justicia social y de defensa de los derechos de los sectores más desprotegidos de nuestra sociedad.

Gravity Probe B Space Vehicle

Science.gov (United States)

2003-01-01

The space vehicle for Gravity Probe B (GP-B) arrives at the launch site at Vandenburg Air Force Base. GP-B is the relativity experiment being developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies that are already enlivening other branches of science and engineering. Scheduled for launch in 2003 and managed for NASA by the Marshall Space Flight Center, development of the GP-B is the responsibility of Stanford University, with major subcontractor Lockheed Martin Corporation.

La introducción del arte flamígero en Castilla: Pedro Jalopa, maestro de los Luna

OpenAIRE

Yuste Galán, Amalia María

2004-01-01

Don Alvaro de Luna, at the height of his power, decided to build a funerary chapel in Toledo Cathedral. In relation to this project Pedro Jalopa appears, possibly the same master who some years earlier had directed the construction of Huesca Cathedral under the patronage of Pope Benedict XIII, great-uncle of Don Alvaro. After his work in Toledo, Jalopa was contracted as master builder at Palencia Cathedral. The powerful Luna family and the close relationship between bishoprics may well have i...

Integrated Structural Health Sensors for Inflatable Space Habitats, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Luna proposes to continue development of integrated high-definition fiber optic sensors (HD-FOS) and carbon nanotube (CNT)-graphene piezoresistive sensors for...

On the occurrence of Lampris luna, Gmel. on the Dutch coast

NARCIS (Netherlands)

Lidth de Jeude, van Th.W.

1889-01-01

On Dec. 8th 1888 a large fish was washed ashore near Scheveningen, and was captured by two fishermen, who brought it to the Leyden Museum. They told us nobody in Scheveningen ever saw such a fish, and were very much surprised as we showed them a stuffed specimen of Lampris luna, captured at

Study of the 2H(p,γ)3He reaction in the BBN energy range at LUNA

Science.gov (United States)

Trezzi, Davide; LUNA Collaboration

2018-01-01

Using Big Bang Nucleosynthesis with the recent cosmological parameters obtained by the Planck collaboration, a primordial deuterium abundance value D/H = (2.65 ± 0.07) × 10-5 is obtained. This one is a little bit in tension with astronomical observations on metal- poor damped Lyman alpha systems where D/H = (2.53 ± 0.04) × 105. In order to reduce the BBN calculation uncertainty, a measurement of the 2H(p,γ)3He cross section in the energy range 10-300 keV with a 3% accuracy is thus desirable. Thanks to the low background of the underground Gran Sasso Laboratories, and to the experience accumulated in more than twenty years of scientific activity, LUNA (Laboratory for Underground Nuclear Astrophysics) planned to measure the 2H(p,γ)3He fusion cross section at the BBN energy range in 2015-2016. A feasibility test of the measurement has been recently performed at LUNA. In this paper, the results obtained will be shown. Possible cosmological outcomes from the future LUNA data will be also discussed.

An Analysis of MARSIS Radar Flash Memory Data from Lunae Planum, Mars: Searching for Subsurface Structures.

Science.gov (United States)

Caprarelli, G.; Orosei, R.; Mastrogiuseppe, M.; Cartacci, M.

2017-12-01

Lunae Planum is a Martian plain measuring approximately 1000 km in width and 2000 km in length, centered at coordinates 294°E-11°N. MOLA elevations range from +2500 m to +500 m in the south, gently sloping northward to -500 m. The plain is part of a belt of terrains located between the southern highlands and the northern lowlands, that are transitional in character (e.g., by elevation, age and morphology). These transitional terrains are poorly understood, in part because of their relative lack of major geomorphological features. They record however a very significant part of Mars's geologic history. The most evident features on Lunae Planum's Hesperian surface are regularly spaced, longitudinally striking, wrinkle ridges. These indicate the presence of blind thrust faults cutting through thick stacks of layers of volcanic or sedimentary rocks. The presence of fluidized ejecta craters scattered all over the region suggests also the presence of ice or volatiles in the subsurface. In a preliminary study of Lunae Planum's subsurface we used the Mars Express ground penetrating radar MARSIS dataset [1], in order to detect reflectors that could indicate the presence of fault planes or layering. Standard radargrams however, provided no evidence of changes in value of dielectric constant that could indicate possible geologic discontinuities or stratification of physically diverse materials. We thus started a new investigation based on processing of raw MARSIS data. Here we report on the preliminary results of this study. We searched the MARSIS archive for raw data stored in flash memory. When operating with flash storage, the radar collects 2 frequency bands along-track covering a distance = 100-250 km, depending on the orbiter altitude [2]. We found flash memory data from 24 orbits over the area. We processed the data focusing radar returns in off-nadir directions, to maximize the likelihood of detecting sloping subsurface structures, including those striking parallel

Chemical Equilibrium and Mineral Saturation in Waters from Oil Wells of the Activo Luna Field, Tabasco, Mexico; Equilibrio quimico y grado de saturacion de minerales en aguas de pozos petroleros de Activo Luna, Tabasco, Mexico

Energy Technology Data Exchange (ETDEWEB)

Barragan R, Rosa Maria; Arellano G, Victor M.; Portugal M, Enrique; Torres R, Vicente [Instituto de Investigaciones Electricas (Mexico); Torres Alvarado, Ignacio [Universidad Nacional Autonoma de Mexico (Mexico); Ascencio C, Fernando; Martinez A; Ana E [Petroleos Mexicanos (Mexico)

2001-09-01

Chemical equilibrium of formation waters from seven oil wells of the Activo Luna field (Tabasco, Mexico) was modelled. Saturation indices of characteristic hydrothermal minerals were calculated at ambient and reservoir conditions in order to predict scaling potential of deep and surface installations. The salinity of waters was found to be in the range from 43,000 (well Escuintle 2) to 250,000 (well Lune 3B) mg/kg as total dissolved solids. The water samples were classified as sodium-chioride type. Ionic strength for the solutions was found to be between 0.75 and 6.5. Activity coefficients were estimated by virial (Pitzer equations) methods using the GEOCHEMIST WORKENCH (GWB) software. Minerals such as anhydrite, halite, alunite, fluorite and barite were found to be supersaturated at reservoir conditions. A solid scale sample obtained from well Luna-3B was analysed. Analysis indicate the presence of calcite, anhydrite, fluorite and sphalerite which suggest the occurrence of temperatures of at least 180 Celcius degrees with acidic conditions and high chemical corrosion potential. [Spanish] Se modelo el equilibrio quimico de aguas de formacion producidas por siete pozos petroleros pertenecientes al Activo Luna, en el estado de Tabasco, Mexico, se calcularon los indices de saturacion de minerales caracteristicos tanto en las condiciones ambiente como en las de yacimiento, con el proposito de apoyar el control de incrustaciones en las instalaciones superficiales y profundas. La salinidad de las salmueras se encontro en el rango de 43,000 (pozos Escuintle 2) a 250,000 (pozos Luna 3B) mg/kg de solidos disueltos totales y las muestras se clasificaron como del tipo clorurado-sodico. La fuerza ionica de las soluciones varia entre 0.75 y 6.5 molar, por lo que los coeficientes de actividad de la modelacion de equilibrio quimico se estimaron por metodos viriales empleando las ecuaciones de Pitzer mediante el programa GEOCHEMIST WORKBENCH (GWB). Minerales como anhidrita, halita

A randomised controlled trial to assess the efficacy of Laparoscopic Uterosacral Nerve Ablation (LUNA in the treatment of chronic pelvic pain: The trial protocol [ISRCTN41196151

Directory of Open Access Journals (Sweden)

2003-12-01

Full Text Available Abstract Background Chronic pelvic pain is a common condition with a major impact on health-related quality of life, work productivity and health care utilisation. The cause of the pain is not always obvious as no pathology is seen in 40–60% of the cases. In the absence of pathology there is no established treatment. The Lee-Frankenhauser sensory nerve plexuses and parasympathetic ganglia in the uterosacral ligaments carry pain from the uterus, cervix and other pelvic structures. Interruption of these nerve trunks by laparoscopic uterosacral nerve ablation (LUNA may alleviate pain. However, the balance of benefits and risks of this intervention have not been reliably assessed. LUNA has, nevertheless, been introduced into practice, although there remains controversy regarding indications for LUNA. Hence, there is an urgent need for a randomised controlled trial to confirm, or refute, any worthwhile effectiveness. The principal hypothesis is that, in women with chronic pelvic pain in whom diagnostic laparoscopy reveals either no pathology or mild endometriosis (AFS score ≤ 5 LUNA alleviates pain and improves life quality at 12 months. Methods/Design The principal objective is to test the hypothesis that in women with chronic pelvic pain in whom diagnostic laparoscopy reveals either no pathology or mild endometriosis (AFS score ≤ 5 LUNA alleviates pain and improves life quality at 12 months. A multi-centre, prospective, randomised-controlled-trial will be carried out with blind assessment of outcomes in eligible consenting patients randomised at diagnostic laparoscopy to LUNA (experimental group or to no pelvic denervation (control group. Postal questionnaires including visual analogue scale for pain (primary outcome, an index of sexual satisfaction and the EuroQoL 5D-EQ instrument (secondary outcomes will be administered at 3, 6 and 12 months. The primary assessment of the effectiveness of LUNA will be from comparison of outcomes at the one

Space Weather Operation at KASI With Van Allen Probes Beacon Signals

Science.gov (United States)

Lee, Jongkil; Kim, Kyung-Chan; Giuseppe, Romeo; Ukhorskiy, Sasha; Sibeck, David; Kessel, Ramona; Mauk, Barry; Giles, Barbara; Gu, Bon-Jun; Lee, Hyesook; Park, Young-Deuk; Lee, Jaejin

2018-02-01

The Van Allen Probes (VAPs) are the only modern National Aeronautics and Space Administration (NASA) spacecraft broadcasting real-time data on the Earth's radiation belts for space weather operations. Since 2012, the Korea Astronomy and Space Science Institute (KASI) has contributed to the receipt of these data via a 7 m satellite-tracking antenna and used these beacon data for space weather operations. An approximately 15 min period is required from measurement to acquisition of Level-1 data. In this paper, we demonstrate the use of VAP data for monitoring space weather conditions at geostationary orbit (GEO) by highlighting the Saint Patrick's Day storm of 2015. During that storm, Probe-A observed a significant increase in the relativistic electron flux at 3 RE. Those electrons diffused outward resulting in a large increase of the electron flux >2 MeV at GEO, which potentially threatened satellite operations. Based on this study, we conclude that the combination of VAP data and National Oceanic and Atmospheric Administration-Geostationary Operational Environmental Satellite (NOAA-GOES) data can provide improved space environment information to geostationary satellite operators. In addition, the findings obtained indicate that more data-receiving sites would be necessary and data connections improved if this or a similar system were to be used as an operational data service.

Luna-Glob project in the context of the past and present lunar ...

Indian Academy of Sciences (India)

seen before. In 1962–1965 America sent several spacecrafts of the Ranger series to the Moon. A significant achievement came when Luna 9 made the first soft landing and provided a TV-panorama of the lunar surface. In 1968, Zond 5 and Zond 6 were the first lunar flyby with biological objects and safely returned to Earth.

Watervogels en fecale bacteriën in de plassen van het Park van Luna

NARCIS (Netherlands)

Kleijn, D.; Meerburg, B.G.

2011-01-01

Het in dit rapport beschreven onderzoek heeft tot doel om vast te stellen of de slechte zwemwaterkwaliteit (te hoge concentraties door watervogels uitgescheiden fecale bacteriën) in de plassen van het Park van Luna, Heerhugowaard, gerelateerd is aan de hoge concentraties onopgeloste bestanddelen in

Birth and death of the Late Cretaceous ``La Luna Sea'', and origin of the Tres Esquinas phosphorites

Science.gov (United States)

Erlich, R. N.; Macsotay I., O.; Nederbragt, A. J.; Lorente, M. Antonieta

2000-05-01

Deposition of organic carbon-rich intervals of the La Luna and Navay formations of northwestern Venezuela was governed by the development of key paleobathymetric barriers (Santa Marta and Santander massifs, Paraguana Block, and ancestral Mérida Andes). These enhanced the development of anoxia in the "La Luna Sea" by causing poor circulation and limited ventilation. Anoxia was also promoted by high evaporation and low precipitation rates (high salinity bottom water), and high levels of marine algal productivity (high organic matter flux). Nutrient supply was augmented by infrequent fluvial sources. Bottom water oxygen levels increased from the Late Santonian through the end of the Cretaceous. Ventilation of anoxic bottom waters may have been enhanced by more frequent or intense seasonal upwelling (caused by higher wind stress) and catastrophic overturn, as well as the removal of a key paleobathymetric barrier. Common byproducts of overturn events were massive phytoplankton blooms, which produced red tides. Fish and marine reptile bone beds within the Tres Esquinas Member (La Luna Formation) are attributed to massive mortality during these events, and are correlative with similar Campanian units in eastern Colombia. During the Maastrichtian, increasing ventilation, combined with siliciclastic dilution, ultimately produced sediments with lower total organic carbon (TOC) content.

Evidencias de grandes precipitaciones en diversas etapas constructivas de la Huaca de la Luna, costa norte del Perú

Directory of Open Access Journals (Sweden)

1993-01-01

Full Text Available ÉVIDENCES DE GRANDES PRECIPITATIONS AU COURS DE DIFFERENTES ETAPES DE LA CONSTRUCTION DE LA HUACA DE LA LUNA, COTE NORD DU PEROU. Les recherches en cours à la Huaca de La Luna - Vallée de Moche ont permis d’établir une séquence de quatre événements constructifs majeurs, ainsi que diverses modifications à l’intérieur de chaque événement. Des sédiments contenant des fines couches de peinture blanche ont été trouvés sur les sols de ces divers événements constructifs et sont interprétés comme le résultat des pluies intenses. Celles-ci ont été produites par le Phénomène du El Niño. Ces nouvelles données permettront de réévaluer les interprétations historiques du site. Las investigaciones que venimos realizando en la Huaca de La Luna - Valle de Moche, han permitido establecer cuatro etapas constructivas, así como diversas modificaciones al interior de cada etapa. Capas de sedimentos conteniendo lentes de pintura, que han sido halladas sobre los pisos arquitectónicos, las interpretamos como el resultado de fuertes lluvias que han lavado el enlucido y la pintura de las paredes. Grandes precipitaciones en la costa norte sólo se dan cuando aparece el Fenómeno de El Niño. Estos nuevos datos permitirán reevaluar las interpretaciones históricas del sitio. EVIDENCES OF HEAVY RAINFALL IN SEVERAL BUILDING STAGES OF HUACA DE LA LUNA, COAST OF NORTHERN PERU. On-going research studies on the Huaca de La Luna (valle of Moche archaeological site lead us to distinguish four episodes of building, as well as several modification stages within each episode. Layers of sediment with remnants of paint that were found on successive floors of this site, are interpreted as evidence of intense rainfall events which were able to wash off the walls. This kind of heavy precipitation seems to be closely related to the El Niño phenomenon. These observations should help to re-calculate former historical interpretations o the site.

Luna : [luuletused] / Kristjan Jaak Peterson ; lühibiograafia: S. S. [Svetlan Semenenko

Index Scriptorium Estoniae

Peterson, Kristian Jaak, 1801-1822

1999-01-01

Sisu: Luna / tlk. Vs. Rozhdestvenski; Druzhba ; Pesnja, slozhennaja v kortshme Tuule po doroge iz Tartu v Rigu, kuda ja otpravilsja navestit rodnõh ; Pesnja Jaaka (on sidit v odinotshestve na gore) / tlk. A. Sokolov ; V den Martina Lutera / tlk. Vs. Rozhdestvenski. Orig.: Kuu ; Sõprus ; Laul, kui ma Tartust läksin Riia poole oma vanemaid vaatama... ; Mardi Lutheruse päeval ; Jaagu laul. Ta istub üksi mäe peal

Sol, Tierra y Luna. Movimientos relativos y sus consecuencias

Directory of Open Access Journals (Sweden)

Sebastián Cardenete García

2011-01-01

Full Text Available Cuando se pregunta a los estudiantes por la causa de las estaciones suelen responder: "en verano estamos más próximos al Sol y en invierno estamos más lejos del Sol". La persistencia de esta idea y el hecho de su generalización entre los estudiantes y muchos adultos me ha inducido a escribir este artículo, en el cual se trata de explicar, de una forma clara y simple, el motivo de este y otros fenómenos debidos al movimiento de la Luna alrededor de la Tierra y de ésta alrededor del Sol.

Investigation of element distributions in Luna-16 regolith

Science.gov (United States)

Kuznetsov, R. A.; Lure, B. G.; Minevich, V. Ia.; Stiuf, V. I.; Pankratov, V. B.

1981-03-01

The concentrations of 32 elements in fractions of different grain sizes in the samples of the lunar regolith brought back by Luna-16 are determined by means of neutron activation analysis. Four groups of elements are distinguished on the basis of the variations of their concentration with grain size, and concentration variations of the various elements with sample depth are also noted. Chemical leaching of the samples combined with neutron activation also reveals differences in element concentrations in the water soluble, metallic, sulphide, phosphate, rare mineral and rock phases of the samples. In particular, the rare earth elements are observed to be depleted in the regolith with respect to chondritic values, and to be concentrated in the phase extracted with 14 M HNO3.

LUNA: low-flying UAV-based forest monitoring system

Science.gov (United States)

Keizer, Jan Jacob; Pereira, Luísa; Pinto, Glória; Alves, Artur; Barros, Antonio; Boogert, Frans-Joost; Cambra, Sílvia; de Jesus, Cláudia; Frankenbach, Silja; Mesquita, Raquel; Serôdio, João; Martins, José; Almendra, Ricardo

2015-04-01

The LUNA project is aiming to develop an information system for precision forestry and, in particular, the monitoring of eucalypt plantations that is first and foremost based on multi-spectral imagery acquired using low-flying uav's. The presentation will focus on the first phase of image acquisition, processing and analysis for a series of pot experiments addressing main threats for early-stage eucalypt plantations in Portugal, i.e. acute , chronic and cyclic hydric stress, nutrient stress, fungal infections and insect plague attacks. The imaging results will be compared with spectroscopic measurements as well as with eco-physiological and plant morphological measurements. Furthermore, the presentation will show initial results of the project's second phase, comprising field tests in existing eucalypt plantations in north-central Portugal.

Curanderas a la sombra de la Huaca de la Luna

Directory of Open Access Journals (Sweden)

2004-01-01

Full Text Available Dans ce travail nous présentons des informations archéologiques sur les représentations de femmes guérisseuses sur des poteries trouvées dans le complexe archéologique des Huacas del Sol et de la Luna. Le métier des femmes guérisseuses est un sujet peu étudié dans l’anthropologie culturelle andine, et la présence de représentations de celles-ci à l’époque Moche démontre une continuité culturelle entre le passé préhispanique et le temps présent. Nous suggérons dans ce travail que l’information recueillie sur la symbolique de “las mesas” de ces femmes guérisseuses est un excellent apport pour les archéologues et historiens des cultures préhispaniques, pour pouvoir comprendre les significations des contextes archélogiques, ou reconstruire la pensée ou l’idéologie de ces dernières. En este trabajo se presenta información arqueológica sobre representaciones de mujeres curanderas en ceramios Moche halladas en el complejo arqueológico Huacas del Sol y de la Luna. El oficio de mujeres curanderas es un tema poco estudiado en la antropología cultural andina, y la presencia de representaciones de estas en época Moche demuestra una continuidad cultural entre el pasado prehispánico y el presente. Sugerimos que la información recopilada sobre la simbología de las mesas de estas mujeres curanderas en este trabajo es una excelente ayuda para los arqueólogos e historiadores de las culturas prehispánicas, cuando buscan comprender los significados de contextos arqueológicos o reconstruir el pensamiento o ideología de ellas. This paper presents archaeological information about female healers or curanderas that are represented on Moche ceramics discovered in the archaeological complex of the Huaca del Sol and the Huaca de la Luna. The work of female healers is a little-studied topic in Andean cultural anthropology and the presence of these curanderas in the Moche period demonstrates cultural continuity between the pre

A randomised controlled trial to assess the efficacy of Laparoscopic Uterosacral Nerve Ablation (LUNA) in the treatment of chronic pelvic pain: The trial protocol [ISRCTN41196151].

Science.gov (United States)

2003-12-08

BACKGROUND: Chronic pelvic pain is a common condition with a major impact on health-related quality of life, work productivity and health care utilisation. The cause of the pain is not always obvious as no pathology is seen in 40-60% of the cases. In the absence of pathology there is no established treatment. The Lee-Frankenhauser sensory nerve plexuses and parasympathetic ganglia in the uterosacral ligaments carry pain from the uterus, cervix and other pelvic structures. Interruption of these nerve trunks by laparoscopic uterosacral nerve ablation (LUNA) may alleviate pain. However, the balance of benefits and risks of this intervention have not been reliably assessed. LUNA has, nevertheless, been introduced into practice, although there remains controversy regarding indications for LUNA. Hence, there is an urgent need for a randomised controlled trial to confirm, or refute, any worthwhile effectiveness. The principal hypothesis is that, in women with chronic pelvic pain in whom diagnostic laparoscopy reveals either no pathology or mild endometriosis (AFS score life quality at 12 months. METHODS/DESIGN: The principal objective is to test the hypothesis that in women with chronic pelvic pain in whom diagnostic laparoscopy reveals either no pathology or mild endometriosis (AFS score life quality at 12 months. A multi-centre, prospective, randomised-controlled-trial will be carried out with blind assessment of outcomes in eligible consenting patients randomised at diagnostic laparoscopy to LUNA (experimental group) or to no pelvic denervation (control group). Postal questionnaires including visual analogue scale for pain (primary outcome), an index of sexual satisfaction and the EuroQoL 5D-EQ instrument (secondary outcomes) will be administered at 3, 6 and 12 months. The primary assessment of the effectiveness of LUNA will be from comparison of outcomes at the one-year follow-up, although the medium-term and longer-term risks and benefits of LUNA will also be

Detecting 3D Vegetation Structure with the Galileo Space Probe: Can a Distant Probe Detect Vegetation Structure on Earth?

Science.gov (United States)

Doughty, Christopher E; Wolf, Adam

2016-01-01

Sagan et al. (1993) used the Galileo space probe data and first principles to find evidence of life on Earth. Here we ask whether Sagan et al. (1993) could also have detected whether life on Earth had three-dimensional structure, based on the Galileo space probe data. We reanalyse the data from this probe to see if structured vegetation could have been detected in regions with abundant photosynthetic pigments through the anisotropy of reflected shortwave radiation. We compare changing brightness of the Amazon forest (a region where Sagan et al. (1993) noted a red edge in the reflectance spectrum, indicative of photosynthesis) as the planet rotates to a common model of reflectance anisotropy and found measured increase of surface reflectance of 0.019 ± 0.003 versus a 0.007 predicted from only anisotropic effects. We hypothesize the difference was due to minor cloud contamination. However, the Galileo dataset had only a small change in phase angle (sun-satellite position) which reduced the observed anisotropy signal and we demonstrate that theoretically if the probe had a variable phase angle between 0-20°, there would have been a much larger predicted change in surface reflectance of 0.1 and under such a scenario three-dimensional vegetation structure on Earth could possibly have been detected. These results suggest that anisotropic effects may be useful to help determine whether exoplanets have three-dimensional vegetation structure in the future, but that further comparisons between empirical and theoretical results are first necessary.

Detecting 3D Vegetation Structure with the Galileo Space Probe: Can a Distant Probe Detect Vegetation Structure on Earth?

Directory of Open Access Journals (Sweden)

Christopher E Doughty

Full Text Available Sagan et al. (1993 used the Galileo space probe data and first principles to find evidence of life on Earth. Here we ask whether Sagan et al. (1993 could also have detected whether life on Earth had three-dimensional structure, based on the Galileo space probe data. We reanalyse the data from this probe to see if structured vegetation could have been detected in regions with abundant photosynthetic pigments through the anisotropy of reflected shortwave radiation. We compare changing brightness of the Amazon forest (a region where Sagan et al. (1993 noted a red edge in the reflectance spectrum, indicative of photosynthesis as the planet rotates to a common model of reflectance anisotropy and found measured increase of surface reflectance of 0.019 ± 0.003 versus a 0.007 predicted from only anisotropic effects. We hypothesize the difference was due to minor cloud contamination. However, the Galileo dataset had only a small change in phase angle (sun-satellite position which reduced the observed anisotropy signal and we demonstrate that theoretically if the probe had a variable phase angle between 0-20°, there would have been a much larger predicted change in surface reflectance of 0.1 and under such a scenario three-dimensional vegetation structure on Earth could possibly have been detected. These results suggest that anisotropic effects may be useful to help determine whether exoplanets have three-dimensional vegetation structure in the future, but that further comparisons between empirical and theoretical results are first necessary.

Means to remove electrode contamination effect of Langmuir probe measurement in space

Energy Technology Data Exchange (ETDEWEB)

Oyama, K.-I.; Lee, C. H.; Fang, H. K.; Cheng, C. Z. [Plasma and Space Science Center, National Cheng Kung University, No.1 Ta-Hsueh Rd., Tainan 70101, Taiwan (China)

2012-05-15

Precaution to remove the serious effect of electrode contamination in Langmuir probe experiments has not been taken in many space measurements because the effect is either not understood or ignored. We stress here that one should pay extra attention to the electrode contamination effect to get accurate and reliable plasma measurements so that the long time effort for sounding rocket/satellite missions does not end in vain or becomes less fruitful. In this paper, we describe two main features of voltage-current characteristic curves associated with the contaminated Langmuir probe, which are predicted from the equivalent circuit model, which we proposed in 1970's. We then show that fast sweeping dc Langmuir probes can give reliable results in the steady state regime. The fast sweeping probe can also give reliable results in transient situations such as satellite moves through plasma bubble in the ionosphere where the electron density drastically changes. This fact was first confirmed in our laboratory experiment.

A 3D Resistivity Model of the Pyramid of La Luna (Teotihuacan, Mexico) Subsoil by Employing Non-Conventional ERT Arrays

Science.gov (United States)

Chavez, R. E.; Tejero, A.; Cifuentes, G.; Garcia-Serrano, A.; Argote-Espino, D. L.; HernaNdez-Quintero, J. E.; Ortega, V.

2017-12-01

The Pyramid of La Luna is found within the archaeological site of Teotihuacan, located to the NE of Mexico City. This pre-Hispanic city was developed between 250 AD and 450 AD, with a population of 100,000 people. The most important edifices are the pyramids of El Sol and La Luna. The pyramid of El Sol is one of the largest pre-Hispanic structures found nowadays in Mexico (a square basement of approximately 200m X 225 m). The pyramid of La Luna (with a base of 140m X 150m), smaller in size is located towards the northern portion of this ancient city. At its front, a big plaza is found surrounded by pyramids of different ages. Previous archaeological studies carried out within the plaza, discovered small shallow pipes for water discharge. Then, it is possible to find deeper structures within the Square. A geophysical work was carried out in the Plaza of La Luna employing the ERT-3D to build a 3D resistivity model. Four ERT profiles were deployed in the area in the E-W direction, with a length of 80 m each; electrodes were inserted 3 m apart. A roll-along technique was employed to obtain a 3D view of the plaza subsoil. Gradient (G), Equatorial (Eq), and Minimum Coupling (MC) arrays were applied. A total of 2,600 apparent resistivity observations were acquired. Also, the pyramid was surrounded with 105 electrodes to illuminate this structure subsoil, employing the 'L' and 'Corner' arrays and the already mentioned settings. Electrodes were separated 5 m for the E and N sides, and 6 m for the W and S sides, topographic correction was added to the interpretation. 7,200 apparent resistivity values were obtained. Processing of the data included noise filtering, real electrode position and removing of spikes. Finally, the data were inverted to compute a 3D resistivity distribution of the subsoil. Preliminary results obtained indicate the presence of high resistivity anomalies probably associated to infill or archaeological features. However, an interesting resistivity

Probing electron correlation and nuclear dynamics in Momentum Space

International Nuclear Information System (INIS)

Deleuze, M S; Hajgato, B; Morini, F; Knippenberg, S

2010-01-01

Orbital imaging experiments employing Electron Momentum Spectroscopy are subject to many complications, such as distorted wave effects, conformational mobility in the electronic ground state, ultra-fast nuclear dynamics in the final state, or a dispersion of the ionization intensity over electronically excited (shake-up) configurations of the cation. The purpose of the present contribution is to illustrate how a proper treatment of these complications enables us to probe in momentum space the consequences of electron correlation and nuclear dynamics in neutral and cationic states.

Il volto della Luna da Plutarco a Newton. Storia di una teoria ellenistica della gravità

Science.gov (United States)

Cappi, Alberto

2013-03-01

In his dialogue "De Facie quae in Orbe Lunae apparet", Plutarch includes a discussion on a non-Aristotelian theory of gravity. I describe how this theory could be developed during the Hellenistic period and its influence on the cosmological debate along the centuries until the beginning of modern science. (Text in Italian)

The RF Probe: providing space situational awareness through broad-spectrum detection and characterization

Science.gov (United States)

Zenick, Raymond; Kohlhepp, Kimberly; Partch, Russell

2004-09-01

AeroAstro's patented RF Probe is a system designed to address the needs of spacecraft developers and operators interested in measuring and analyzing near-field RF emissions emanating from a nearby spacecraft of interest. The RF Probe consists of an intelligent spectrum analyzer with digital signal processing capabilities combined with a calibrated, wide-bandwidth antenna and RF front end that covers the 50 kHz to 18 GHz spectrum. It is capable of acquiring signal level and signal vector information, classifying signals, assessing the quality of a satellite"s transponders, and characterizing near-field electromagnetic emissions. The RF Probe is intended for either incorporation as part of a suite of spacecraft sensors, or as a stand-alone sensor on spacecraft or other platforms such as Unmanned Aerial Vehicles (UAVs). The RF Probe was initially conceived as a tool to detect and aid in diagnosis of malfunctions in a spacecraft of interest. However, the utility of the RF Probe goes far beyond this initial concept, spanning a wide range of military applications. Most importantly, the RF Probe can provide space situational awareness for critical on-orbit assets by detecting externally induced RF fields, aiding in protection against potentially devastating attacks.

Space Systems Failures Disasters and Rescues of Satellites, Rockets and Space Probes

CERN Document Server

Harland, David M

2005-01-01

In the 1960s and 1970s deep space missions were dispatched in pairs in case one was lost in launch or failed during its journey. Following the triumphs of the Viking landings on Mars in 1976 and both Voyagers spacecraft successfully surveying the outer giant planets of the Solar System, it was decided by NASA to cut costs and send out just a single probe. Although Magellan successfully mapped Venus by radar, it suffered from problems during the flight. Then came the loss of Mars Observer, whose engine exploded as it was preparing to enter Mars’ orbit because it was using technology designed for Earth’s satellites and the engine was not suited to spending several months in space. Later came the high-profile losses of Mars Climate Observer and Mars Polar Lander - a consequence of the faster, better, cheaper philosophy introduced by Dan Goldin in 1993. Even the highly successful Galileo mission suffered a major setback when its high-gain antenna (also based on satellite mission suffered a major setback when ...

The Luna stain, an improved selective stain for detection of microsporidian spores in histologic sections

Science.gov (United States)

Peterson, Tracy S.; Spitsbergen, Jan M.; Feist, Stephen W.; Kent, Michael L.

2014-01-01

Microsporidia in histologic sections are most often diagnosed by observing spores in host tissues. Spores are easy to identify if they occur in large aggregates or xenomas when sections are stained with hematoxylin and eosin (H&E). However, individual spores are not frequently detected in host tissues with conventional H&E staining, particularly if spores are scattered within the tissues, areas of inflammation or small spores in nuclei (i.e., Nucleospora salmonis). Hence, a variety of selective stains that enhance visualization of spores are recommended. We discovered that the Luna stain, used to highlight eosinophils, red blood cells and chitin in arthropods and other invertebrates, also stains spores of Pseudoloma neurophilia. We compared this stain to the Gram, Fite’s acid fast, Giemsa, and H&E stains on eight aquatic microsporidian organisms that were readily available in our two laboratories: Loma salmonae, Glugea anomala, Pseudoloma neurophilia, Pleistophora hyphessobryconis, Pleistophora vermiformis, Glugea sp., Steinhausia mytilovum and an unidentified microsporidian from E. sinensis, UK. Based on tinctorial properties and background staining, the Luna stain performed better for detection of 6 of the 8 microsporidia. Gram stain was superior for the two microsporidia from invertebrates, Steinhausia mytilovum and the unidentified microsporidian from E. sinensis. PMID:21848126

Thermogravimetric and x-ray diffraction analyses of Luna-24 regolith samples

International Nuclear Information System (INIS)

Deshpande, V.V.; Dharwadkar, S.R.; Jakkal, V.S.

1979-01-01

Two samples of Luna-24 were analysed by X-ray diffraction and thermogravimetric (TG) techniques. The sample 24123.12 shows a weight loss of nearly 0.85 percent between 23O-440deg C and followed by 1.16 percent weight gain from 500 to 800deg C. The sample 23190.13 showed only a weight gain of about 1.5 percent from 5O0deg C to 900deg C. X-ray diffraction analyses show the presence of olivine, plagioclase, pigeonite, enstatite, and native iron in both the virgin samples. The heated samples, however, show that only the native iron got oxidized to iron oxide. The other constituents remain unaltered. (auth.)

The Power of Love: Rewriting the Romance in Isabel Allende's The House of the Spirits and Eva Luna

Directory of Open Access Journals (Sweden)

Frances Jane P. Abao

2000-12-01

Full Text Available Despite its ongoing popularity with women readers, romantic fiction has traditionally been regarded as an instrument of women's oppression, largely due to its reinforcement and even glorification of sexual stereotypes and bourgeois values. Latin American writer Isabel Allende's novels The House of the Spirits and Eva Luna both contain a number of the elements and conventions of romantic fiction, including distinct similarities to the two acknowledged foundations of this genre: Charlotte Brontë's Jane Eyre and Emily Brontë's Wuthering Heights.However, The House of the Spirits and Eva Luna can also be read as rewritings of the genre of romantic fiction. In these two texts, Isabel Allende appropriates and then reworks certain conventions of romantic fiction in order to portray her notion of "fulfilling egalitarian relationships" between men and women. Nevertheless, despite these feminist revisions, Allende's rewritten romances do retain the "wish-fulfillment" element-or ideal-of romantic fiction, its depiction of women's fantasy of feminine values being appreciated and validated within heterosexual romantic relationships in the real world.

Las Lunas (Yuncler, Toledo. A Bronze Age hoard with metallic materials from the southern Iberian Meseta

Directory of Open Access Journals (Sweden)

Urbina Martínez, Dionisio

2010-06-01

Full Text Available Here we present the results of the preliminary study carried out on a new group of metallic materials of the Final Bronze Age, recovered at the end of 2008 in the archaeological excavations at the settlement of Las Lunas (Yuncler, Toledo, Spain. Its geographical situation far away from the main zones of distribution of this type of finds, the singularity of the materials, and the evidence of Atlantic and Mediterranean relations make these materials a remarkable sample for the study of the Final Bronze Age in the centre of the Iberian Peninsula.

Se exponen los resultados del primer estudio realizado sobre un nuevo conjunto de materiales metálicos del Bronce Final recuperado a finales de 2008 en las excavaciones arqueológicas del yacimiento de Las Lunas (Yuncler, Toledo, España. La localización geográfica del hallazgo, lejos de las principales zonas de dispersión conocidas para este tipo de conjuntos, la singularidad de los objetos que integra, y las relaciones atlánticas y mediterráneas que evidencian sus materiales, lo convierten en un ejemplo destacado para el estudio de este período en el centro de la Península Ibérica.

Pratiques sacrificielles et funéraires au site Moche de la Huaca de La Luna, côte nord du Pérou

Directory of Open Access Journals (Sweden)

1998-01-01

Full Text Available De récentes recherches archéologiques au site Moche de la Huaca de la Luna ont conduit à la découverte d’un important site sacrificiel et d’une plate-forme funéraire. Dans une enceinte située vers l’arrière du temple et jointe à la plate-forme principale, plusieurs individus auraient été sacrifiés lors de pluies torrentielles (phénomène de El Niño. Dans une structure attenante au site sacrificiel, des tombes ont également été localisées dont celles de deux officiants religieux. Des artefacts retrouvés dans ces sépultures semblent indiquer que ceux-ci étaient des spécialistes du sacrifice. Certains résultats préliminaires seront présentés ici. Il appert d’ores et déjà que ce site exceptionnel permettra de mieux comprendre les dimensions funéraires et sacrificielles du système idéologique et religieux Moche. PRÁCTICAS SACRIFICIALES Y FUNERARIAS EN EL SITIO MOCHE DE LA HUACA DE LA LUNA, COSTA NORTE DEL PERÚ. Investigaciones arqueológicas realizadas en el sitio Moche de la Huaca de la Luna han conducido al descubrimiento de un importante sitio sacrificial y de una plataforma funeraria. En primer lugar, en una plaza de la Huaca, numerosos individuos habrían sido sacrificados durante lluvias torrenciales (fenómeno de El Niño. En segundo lugar, en una plataforma asociada a la plaza, cuatro tumbas elaboradas han sido localizadas. Algunos elementos descubiertos en dos de estas tumbas parecen indicar que serían las de dos especialistas de los sacrificios. Solamente los resultados preliminares estarán presentados aquí, pero parece que este sitio excepcional permitirá comprender mejor las dimensiones funerarias y sacrificiales del sistema ideológico y religioso Moche. SACRIFICIAL AND FUNERARY PRACTICES AT THE MOCHE SITE HUACA DE LA LUNA, NORTH COAST OF PERU. Archaeological research carried out at the Moche site of Huaca de la Luna has led to the discovery of a sacrificial site and a funerary platform. A number

Nuclear power in space. Use of reactors and radioactive substances as power sources in satellites and space probes

International Nuclear Information System (INIS)

Hoestbaeck, Lars

2008-11-01

Today solar panels are the most common technique to supply power to satellites. Solar panels will work as long as the power demand of the satellite is limited and the satellite can be equipped with enough panels, and kept in an orbit that allows enough sunlight to hit the panels. There are various types of space missions that do not fulfil these criteria. With nuclear power these types of missions can be powered regardless of the sunlight and as early as 1961 the first satellite with a nuclear power source was placed in orbit. Out of seventy known space missions that has made use of nuclear power, ten have had some kind of failure. In no case has the failure been associated with the nuclear technology used. This report discusses to what degree satellites with nuclear power are a source for potential radioactive contamination of Swedish territory. It is not a discussion for or against nuclear power in space. Neither is it an assessment of consequences if radioactive material from a satellite would reach the earth's surface. Historically two different kinds of Nuclear Power Sources (NPS) have been used to generate electric power in space. The first is the reactor where the energy is derived from nuclear fission of 235 U and the second is the Radioisotope Thermoelectric Generator (RTG) where electricity is generated from the heat of naturally decaying radionuclides. NPS has historically only been used in space by United States and the Soviet Union (and in one failing operation Russia). Nuclear Power Sources have been used in three types of space objects: satellites, space probes and moon/Mars vehicles. USA has launched one experimental reactor into orbit, all other use of NPS by the USA has been RTG:s. The Soviet Union, in contrast, only launched a few RTG:s but nearly forty reactors. The Soviet use of NPS is less transparent than the use in USA and some data published on Soviet systems are more or less well substantiated assessments. It is likely that also future

Mobile Probing and Probes

DEFF Research Database (Denmark)

Duvaa, Uffe; Ørngreen, Rikke; Weinkouff Mathiasen, Anne-Gitte

2013-01-01

Mobile probing is a method, developed for learning about digital work situations, as an approach to discover new grounds. The method can be used when there is a need to know more about users and their work with certain tasks, but where users at the same time are distributed (in time and space......). Mobile probing was inspired by the cultural probe method, and was influenced by qualitative interview and inquiry approaches. The method has been used in two subsequent projects, involving school children (young adults at 15-17 years old) and employees (adults) in a consultancy company. Findings point...... to mobile probing being a flexible method for uncovering the unknowns, as a way of getting rich data to the analysis and design phases. On the other hand it is difficult to engage users to give in depth explanations, which seem easier in synchronous dialogs (whether online or face2face). The development...

Mobile Probing and Probes

DEFF Research Database (Denmark)

Duvaa, Uffe; Ørngreen, Rikke; Weinkouff, Anne-Gitte

2012-01-01

Mobile probing is a method, which has been developed for learning about digital work situations, as an approach to discover new grounds. The method can be used when there is a need to know more about users and their work with certain tasks, but where users at the same time are distributed (in time...... and space). Mobile probing was inspired by the cultural probe method, and was influenced by qualitative interview and inquiry approaches. The method has been used in two subsequent projects, involving school children (young adults at 15-17 years old) and employees (adults) in a consultancy company. Findings...... point to mobile probing being a flexible method for uncovering the unknowns, as a way of getting rich data to the analysis and design phases. On the other hand it is difficult to engage users to give in depth explanations, which seem easier in synchronous dialogs (whether online or face2face...

Probe Techniques. Introductory Remarks

Energy Technology Data Exchange (ETDEWEB)

Emeleus, K. G. [School of Physics and Applied Mathematics, Queen' s University, Belfast (United Kingdom)

1968-04-15

In this brief introduction to the session on probes, the history of theii development is first touched on briefly. Reference is then made to the significance of the work to be described by Medicus, for conductivity and recombination calculations, and by Lam and Su, for a wide range of medium and higher pressure plasmas. Finally, a number of other probe topics are mentioned, including multiple probes; probes in electronegative plasmas; resonance probes; probes in noisy discharges; probes as oscillation detectors; use of probes where space-charge is not negligible. (author)

New SRDN-3 probes with a semi-conductor detector for measuring radon activity concentration in underground spaces

International Nuclear Information System (INIS)

Przylibski, T.A.; Lidia Fijalkowska-Lichwa; Elzbieta Kochowska; Krzysztof Kozak; Jadwiga Mazur

2010-01-01

The article presents new Polish probes SRDN-3, developed at the Institute of Nuclear Chemistry and Technology in Warsaw, equipped with a semi-conductor detector used for continuous measurements of 222 Rn activity concentration. Due to a relatively high lower detection limit, the device is dedicated for use in underground spaces-caves, adits, mines, tourist routes in strongholds, pyramids, etc. Its structure allows for difficult conditions in which the device is transported to the measurement site, as well as hard operating conditions caused chiefly by large ambient relative humidity, reaching up to 100%. The authors present calibration results of these appliances, as well as the results of their work in a cave and an adit in the Sudetes (SW Poland). After almost 2 years of working in difficult conditions, the probes displayed high reliability. No defects of the semi-conductor detectors or the electronics were observed, which ensured problem-free communication of the probe-programmer-PC set. Thanks to this, the authors have a 2 year stock of data, recorded hourly by five probes, at their disposal. The only element that did not withstand the test of extreme operating conditions was one of the combined relative humidity and temperature sensors. No powering problems were observed either, and the batteries were replaced once a year, before the winter season. Also the programmer functioned faultlessly, enabling data transmission to a PC, which, being much more sensitive to operating conditions, had been placed away from the site of probe exposure. After using more sensitive temperature, relative humidity and pressure sensors, SRDN-3 probes will certainly prove an excellent tool for microclimate measurements (including measurement of air-atmosphere exchange) in caves and other underground sites. Even nowadays they are already a satisfactory tool for monitoring 222 Rn concentration in underground spaces. (author)

Facies and diagenesis of the Devonian Portilla limestone formation between the river Esla and the Embalse de la Luna, Cantabrian Mountains, Spain

NARCIS (Netherlands)

Reijers, T.J.A.

1972-01-01

In the central part of the Cantabrian Mountains, between the artificial lake in the rivei Luna in the west and the river Esla in the east, outcrops of the Portilla Limestone Formation were investigated. A fairly uniform development could be observed in four structurally different areas. Six

Galactically inertial space probes for the direct measurement of the metric expansion of the universe

International Nuclear Information System (INIS)

Cagnani, Ivan

2011-01-01

Astrometric data from the future GAIA and OBSS missions will allow a more precise calculation of the local galactic circular speed, and better measurements of galactic movements relative to the CMB will be obtained by post-WMAP missions (ie Planck). Contemporary development of high specific impulse electric propulsion systems (ie VASIMIR) will enable the development of space probes able to properly compensate the galactic circular speed as well as the resulting attraction to the centre of our galaxy. The probes would appear immobile to an ideal observer fixed at the centre of the galaxy, in contrast of every other galactic object, which would appear moving according to their local galactic circular speed and their proper motions. Arranging at least three of these galactically static probes in an extended formation and measuring reciprocal distances of the probes over time with large angle laser ranges could allow a direct measurement of the metric expansion of the universe. Free-drifting laser-ranged targets released by the spacecrafts could also be used to measure and compensate solar system's induced local perturbations. For further reducing local effects and increase the accuracy of the results, the distance between the probes should be maximized and the location of the probes should be as far as possible from the Sun and any massive object (ie Jupiter, Saturn). Gravitational waves could also induce random errors but data from GW observatories like the planned LISA could be used to correct them.

Van Allen Probes Mission Space Academy: Educating middle school students about Earth's mysterious radiation belts

Science.gov (United States)

Butler, L.; Turney, D.; Matiella Novak, A.; Smith, D.; Simon, M.

2013-12-01

How's the weather in space? Why on Earth did NASA send two satellites above Earth to study radiation belts and space weather? To learn the answer to questions about NASA's Van Allen Probes mission, 450 students and their teachers from Maryland middle schools attended Space Academy events highlighting the Van Allen Probes mission. Sponsored by the Applied Physics Laboratory (APL) and Discovery Education, the events are held at the APL campus in Laurel, MD. Space Academies take students and teachers on behind-the-scenes exploration of how spacecraft are built, what they are designed to study, and introduces them to the many professionals that work together to create some of NASA's most exciting projects. Moderated by a public relations representative in the format of an official NASA press conference, the daylong event includes a student press conference with students as reporters and mission experts as panelists. Lunch with mission team members gives students a chance to ask more questions. After lunch, students don souvenir clean room suits, enjoy interactive science demonstrations, and tour APL facilities where the Van Allen Probes were built and tested before launch. Students may even have an opportunity to peek inside a clean room to view spacecraft being assembled. Prior to the event, teachers are provided with classroom activities, lesson plans, and videos developed by APL and Discovery Education to help prepare students for the featured mission. The activities are aligned to National Science Education Standards and appropriate for use in the classroom. Following their visit, student journalists are encouraged to write a short article about their field trip; selections are posted on the Space Academy web site. Designed to engage, inspire, and influence attitudes about space science and STEM careers, Space Academies provide an opportunity to attract underserved populations and emphasize that space science is for everyone. Exposing students to a diverse group of

Space-time electrostatic probing of low-pressure discharge lamps during the early stages of electrical breakdown

NARCIS (Netherlands)

Gendre, M.F.; Bowden, M.D.; Haverlag, M.; Nieuwenhuizen, van den H.C.M.; Gielen, J.W.A.M.; Kroesen, G.M.W.

2005-01-01

The lime and space evolution of the electrostatic potential of a low-pressure lamp is investigated during ignition with a special capacitive probe. Observations show that ionisation waves propagate back and forth in the lamp, coinciding with the displacement of a local region of strong potential

Post Process Characterization of Friction Stir Welded Components, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Luna Innovations Incorporated proposes in this STTR Phase II project to continue development and validation of Luna's amplitude-dependent, nonlinear ultrasonic...

Nuclear astrophysics deep underground the case of the 15N(p,γ)16O reaction at LUNA

CERN Document Server

Mazzocchi, Chiara

2010-01-01

Measuring nuclear reactions of astrophysical interest at the relevant energies is not always possible on the Earth’s surface because of the cosmic-ray background that dominates the spectra. The LUNA collaboration exploits the lowbackground enviroment of Gran Sasso National Laboratory to study these reactions at or close to the Gamow peak. The latest experimental efforts included the measurement of the 15N(p,γ)16O at beam energies between 77 and 350 keV. The status of these measurements is summarised in this contribution.

On the over-collection of electrons by high voltage probes in space

International Nuclear Information System (INIS)

Cooke, D.L.; Katz, I.; Jongeward, G.; Mandell, M.

1988-01-01

It has been two decades since Parker and Murphy proposed a theory to place a rigorous upper bound on the current to an electron collecting probe in space, due to the influence of the geomagnetic field. Any greater current is then thought to involve some form of anomalous cross field transport to explain over-collection. Over-collection is commonly observed and is usually explained by invoking turbulence as a source of collisions. Although the turbulence hypothesis has some theoretical basis, no compelling kinetic theory or model has been put forth. Another possible explanation for over-collection is the ionization of the neutral gas within the charge sheath. Recently, in support of the SPEAR I rocket experiment, the three dimensional code POLAR has been used to model electron collection in a low earth orbit plasma. SPEAR I was a sounding rocket experiment that exposed to the space plasma, a pair of 10cm spherical probes biased to 44kV positive. The POLAR runs included single sphere, two sphere, and two sphere plus rocket modes. The single sphere model did not predict collection in excess of the Parker-Murphy limit. Models of two sphere collection, and of the entire experiment do however show that increased collection is possible as a result of asymetries introduced by geometry and a negative rocket body potential. These models were in close agreement with the experiment. In addition to the symmetry factor, sheath ionization is reviewed. A discussion of the role and kinetic nature of collisionless turbulence is presented

Gravity Probe B Inspection

Science.gov (United States)

2000-01-01

The space vehicle Gravity Probe B (GP-B) is the relativity experiment developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies that are already enlivening other branches of science and engineering. In this photograph, engineer Gary Reynolds is inspecting the inside of the probe neck during probe thermal repairs. GP-B is scheduled for launch in April 2004 and managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Russ Leese, Gravity Probe B, Stanford University)

Electrical resistivity probes

Science.gov (United States)

Lee, Ki Ha; Becker, Alex; Faybishenko, Boris A.; Solbau, Ray D.

2003-10-21

A miniaturized electrical resistivity (ER) probe based on a known current-voltage (I-V) electrode structure, the Wenner array, is designed for local (point) measurement. A pair of voltage measuring electrodes are positioned between a pair of current carrying electrodes. The electrodes are typically about 1 cm long, separated by 1 cm, so the probe is only about 1 inch long. The electrodes are mounted to a rigid tube with electrical wires in the tube and a sand bag may be placed around the electrodes to protect the electrodes. The probes can be positioned in a borehole or on the surface. The electrodes make contact with the surrounding medium. In a dual mode system, individual probes of a plurality of spaced probes can be used to measure local resistance, i.e. point measurements, but the system can select different probes to make interval measurements between probes and between boreholes.

Modelado, Simulación y Control de Satélites en los Puntos de Lagrange del Sistema Tierra - Luna

Directory of Open Access Journals (Sweden)

F. Alonso Zotes

2011-07-01

Full Text Available Resumen: El objetivo de este artículo es modelar, analizar y controlar una constelación de cinco satélites, situados en los puntos de Lagrange del sistema Tierra – Luna. El modelo se ha desarrollado incluyendo efectos complejos no considerados habitualmente, como el viento solar, la no esfericidad de los planetas y la deriva de la órbita lunar, para hacerlo más realista. Sobre los satélites se ejerce una propulsión continua, calculada por medio de controladores tipo PD, tanto convencionales como borrosos, y cuya finalidad es situar y mantener a cada satélite en su punto de Lagrange frente a las inestabilidades y derivas inherentes al sistema. El sistema completo se ha implementado en el lenguaje de modelado Modelica, para el que se han creado una serie de elementos aeroespaciales, y las simulaciones se han desarrollado con el software Dymola. Tanto con los controladores clásicos como con los borrosos se han obtenido muy buenos resultados. Palabras clave: modelado, simulación, control borroso, satélites, puntos de Lagrange, sistema Tierra-Luna

Getting together in deep space - The Rosetta space probe's long trek to Comet 67/P Churyumov-Gerasimenko

Science.gov (United States)

2004-02-01

The countdown to Rosetta’s rendezvous in space began on 1 March 1997. At the end of February 2004, seven years and not a few headaches later, the European Space Agency (ESA) probe will at last be setting off on its journey to meet Comet Churyumov-Gerasimenko. The long-planned get-together will not however take place until the middle of 2014. A few months after arriving at the comet, Rosetta will release a small lander onto its surface. Then, for almost two years it will investigate Churyumov-Gerasimenko from close up. Dr Gerhard Schwehm, lead scientist for the Rosetta project, explains that, “With this mission we will be breaking new ground - this will be the first protracted cometary encounter.” The trip to the meeting place in space will certainly be a long one, located as it is some 4.5 astronomical units from the Sun, which translates into something like 675 million kilometres. Rosetta will be on the road for ten years, during which time it will clock up in excess of five billion kilometres. Launch in February 2004 Rosetta will be waved off on 26 February when it lifts off from the space centre in Kourou, French Guiana, aboard an Ariane 5 launcher. Shortly after the spacecraft’s release, its solar panels will be deployed and turned towards the Sun to build up the necessary power reserves. Its various systems and experiments will be gradually brought into operation and tested. Just three months into the mission the first active phase will be over, followed by final testing of the experiments in October 2004. Rosetta will then spend the following years flying a lonely path to the comet, passing by the Earth, Mars, the Earth and the Earth again. There is no alternative to this detour, for even Ariane 5, the most powerful launcher on the market today, lacks the power to hurl the probe on a direct route to the comet. To get the required momentum, it will rely on swing-by manœuvres, using the gravitation pull of Mars (in 2007) and the Earth (three times, in

THE 2H(alpha, gamma6LI REACTION AT LUNA AND BIG BANG NUCLEOSYNTHETIS

Directory of Open Access Journals (Sweden)

Carlo Gustavino

2013-12-01

Full Text Available The 2H(α, γ6Li reaction is the leading process for the production of 6Li in standard Big Bang Nucleosynthesis. Recent observations of lithium abundance in metal-poor halo stars suggest that there might be a 6Li plateau, similar to the well-known Spite plateau of 7Li. This calls for a re-investigation of the standard production channel for 6Li. As the 2H(α, γ6Li cross section drops steeply at low energy, it has never before been studied directly at Big Bang energies. For the first time the reaction has been studied directly at Big Bang energies at the LUNA accelerator. The preliminary data and their implications for Big Bang nucleosynthesis and the purported 6Li problem will be shown.

DC Langmuir Probe for Measurement of Space Plasma: A Brief Review

Directory of Open Access Journals (Sweden)

Koichiro Oyama

2015-09-01

Full Text Available Herein, we discuss the in situ measurement of the electron temperature in the ionosphere/plasmasphere by means of DC Langmuir probes. Major instruments which have been reported are a conventional DC Langmuir probe, whose probe voltage is swept; a pulsed probe, which uses pulsed bias voltage; a rectification probe, which uses sinusoidal signal; and a resonance cone probe, which uses radio wave propagation. The content reviews past observations made with the instruments above. We also discuss technical factors that should be taken into account for reliable measurement, such as problems related to the contamination of electrodes and the satellite surface. Finally, we discuss research topics to be studied in the near future.

Active Probing of Space Plasmas

Science.gov (United States)

1989-09-01

ft. shuttle wake mlay also a kect the optration (if mi’:nc di.tg. Ibk Prwwattr of ,frttirw 844 I. %rvaom ’itbi h" $od iy radlet 6�va of IkeA dtm t...probe had a specially designed inner shaft caused by the existence of some ballistic electrons after made with .pring sleel tubing. By externally...potential to the electron thermal energy i(s distances downstream of the body (see Fig. 1). This (e OIT,) was on the order of 10 in steady state. design

Interaction of a ballistic probe with gaseous media

International Nuclear Information System (INIS)

Kucerovsky, Zden; Greason, William D

2008-01-01

Free-flying metal probes are used to determine charge densities in gaseous media containing free charge or low density plasma. The trajectory of the probe is ensured either by gravity or by propelling the probe to a certain velocity at the launch site. While travelling, the probe charge changes from its launch-site magnitude to that related to the space charge density existing along the trajectory. The degree to which the probe's arrival-site charge magnitude matches the space charge density in the area of interest depends on the probe shape and on the charge exchange processes between the probe body and the medium. The paper studies a probe acting as a free-flying charge carrier in air, and discusses the problems that may lead to an imbalance between the charge collected by the probe in the area of interest and the charge measured at the arrival site. The analysis and the described experiments are of the ballistic type: a small, triboelectrically pre-charged metal probe was propelled on a horizontal path, and the charge carried by the probe was measured at several points along the trajectory by means of contact-free induction rings; the initial and final charges were determined by static Faraday cups. A charge disparity was found under certain conditions, and its degree explained by the effects of the charge carrier potential. The studied probe charges ranged from 10 to 50 nF, and the fly-times needed to cross a one-meter path ranged from 20 to 40 ms. The probe to gas charge exchange experiments and their analysis yielded conditions under which the probe lost approximately 10 % of its charge. The results of our study may be of interest to those who intend to use the free-flying probe technique for the determination of space charge density.

Science with the space-based interferometer LISA. IV: Probing inflation with gravitational waves

CERN Document Server

Bartolo, Nicola; Domcke, Valerie; Figueroa, Daniel G.; Garcia-Bellido, Juan; Guzzetti, Maria Chiara; Liguori, Michele; Matarrese, Sabino; Peloso, Marco; Petiteau, Antoine; Ricciardone, Angelo; Sakellariadou, Mairi; Sorbo, Lorenzo; Tasinato, Gianmassimo

2016-01-01

We investigate the potential for the LISA space-based interferometer to detect the stochastic gravitational wave background produced from different mechanisms during inflation. Focusing on well-motivated scenarios, we study the resulting contributions from particle production during inflation, inflationary spectator fields with varying speed of sound, effective field theories of inflation with specific patterns of symmetry breaking and models leading to the formation of primordial black holes. The projected sensitivities of LISA are used in a model-independent way for various detector designs and configurations. We demonstrate that LISA is able to probe these well-motivated inflationary scenarios beyond the irreducible vacuum tensor modes expected from any inflationary background.

Science with the space-based interferometer LISA. IV: probing inflation with gravitational waves

International Nuclear Information System (INIS)

Bartolo, Nicola; Guzzetti, Maria Chiara; Liguori, Michele; Matarrese, Sabino

2016-01-01

We investigate the potential for the LISA space-based interferometer to detect the stochastic gravitational wave background produced from different mechanisms during inflation. Focusing on well-motivated scenarios, we study the resulting contributions from particle production during inflation, inflationary spectator fields with varying speed of sound, effective field theories of inflation with specific patterns of symmetry breaking and models leading to the formation of primordial black holes. The projected sensitivities of LISA are used in a model-independent way for various detector designs and configurations. We demonstrate that LISA is able to probe these well-motivated inflationary scenarios beyond the irreducible vacuum tensor modes expected from any inflationary background.

Probing the Solar System

Science.gov (United States)

Wilkinson, John

2013-01-01

Humans have always had the vision to one day live on other planets. This vision existed even before the first person was put into orbit. Since the early space missions of putting humans into orbit around Earth, many advances have been made in space technology. We have now sent many space probes deep into the Solar system to explore the planets and…

Probe-holding apparatus for holding a probe for checking steam generator tubes particularly in a nuclear reactor installation

International Nuclear Information System (INIS)

Adamowski, A.; Gagny; Gallet, G.; Lhermitte, J.; Monne, M.; Vautherot, G.

1984-01-01

Probe-holding apparatus for holding a probe for checking steam generator tubes particularly in a nuclear reactor installation. The apparatus comprises a telescopic arm supported via a ball and socket joint from a support mounted in or near an access aperture in a chamber at one end of the steam generator. A probe guide is carried by a carriage pivotally mounted at the other end of the telescopic arm. The carriage includes an endless belt having a series of spaced projections which engage into the ends of the tubes, the projections being spaced by a distance equal to the tube pitch or a multiple thereof. The belt is driven by a stepping motor in order to move the carriage and place the probe guide opposite different ones of the tubes

Giotto: the european space probe

International Nuclear Information System (INIS)

Berner, C.; Vandenbussche, F.C.

1986-01-01

The Giotto mission is an in situ exploration of the comet Halley. It will be the European Space Agency's first operational deep-space mission, with a spacecraft-Earth distance at comet encounter of approximately 1 AU (150 000 000 km). This paper gives a summary of the mission profile, of the spacecraft design with its associated payload and ground segment [fr

Electrical conduction through surface superstructures measured by microscopic four-point probes

DEFF Research Database (Denmark)

Hasegawa, S.; Shiraki, I.; Tanabe, F.

2003-01-01

For in-situ measurements of the local electrical conductivity of well-defined crystal surfaces in ultra-high vacuum, we have developed two kinds of microscopic four-point probe methods. One involves a "four-tip STM prober," in which four independently driven tips of a scanning tunneling microscope...... (STM) are used for measurements of four-point probe conductivity. The probe spacing can be changed from 500 nm to 1 mm. The other method involves monolithic micro-four-point probes, fabricated on silicon chips, whose probe spacing is fixed around several mum. These probes are installed in scanning...

Scanning microscopic four-point conductivity probes

DEFF Research Database (Denmark)

Petersen, Christian Leth; Hansen, Torben Mikael; Bøggild, Peter

2002-01-01

A method for fabricating microscopic four-point probes is presented. The method uses silicon-based microfabrication technology involving only two patterning steps. The last step in the fabrication process is an unmasked deposition of the conducting probe material, and it is thus possible to select...... the conducting material either for a silicon wafer or a single probe unit. Using shadow masking photolithography an electrode spacing (pitch) down to 1.1 mum was obtained, with cantilever separation down to 200 run. Characterisation measurements have shown the microscopic probes to be mechanically very flexible...

Gravity Probe B: final results of a space experiment to test general relativity.

Science.gov (United States)

Everitt, C W F; DeBra, D B; Parkinson, B W; Turneaure, J P; Conklin, J W; Heifetz, M I; Keiser, G M; Silbergleit, A S; Holmes, T; Kolodziejczak, J; Al-Meshari, M; Mester, J C; Muhlfelder, B; Solomonik, V G; Stahl, K; Worden, P W; Bencze, W; Buchman, S; Clarke, B; Al-Jadaan, A; Al-Jibreen, H; Li, J; Lipa, J A; Lockhart, J M; Al-Suwaidan, B; Taber, M; Wang, S

2011-06-03

Gravity Probe B, launched 20 April 2004, is a space experiment testing two fundamental predictions of Einstein's theory of general relativity (GR), the geodetic and frame-dragging effects, by means of cryogenic gyroscopes in Earth orbit. Data collection started 28 August 2004 and ended 14 August 2005. Analysis of the data from all four gyroscopes results in a geodetic drift rate of -6601.8±18.3  mas/yr and a frame-dragging drift rate of -37.2±7.2  mas/yr, to be compared with the GR predictions of -6606.1  mas/yr and -39.2  mas/yr, respectively ("mas" is milliarcsecond; 1  mas=4.848×10(-9)  rad).

Eclipse parcial de Luna - 23-24 de Marzo de 1997

Science.gov (United States)

Arquiola, A. P.; Arquiola, F. E.

Luego de varios años en que las condiciones climáticas no nos permitían registrar el fenómeno, pudimos observar y realizar secuencias fotográficas del eclipse parcial Luna. Siendo de una magnitud de 0.92 (muy cercano a la totalidad) se obtuvo una serie de fotografías muy claras y preferentemente con gran contraste a fin de destacar las tonalidades de las sombras, en especial la penumbra, que desde ya el clima nos favoreció. Los métodos fotográficos fueron, en primer lugar, con telezoom de 210mm a f/4.5 con película color de 1600 ASA; y el ya clásico método a foco primario en el Telescopio Schmidt - Cassegrain de 200mm a f/10. Paralelamente a la observación del eclipse, estábamos al instante comunicados por correo electrónico con otros observadores desde diferentes lugares del mundo intercambiando reportes, y también usuarios en general de la red, de esta forma se hizo muy especial el fenómeno. Instrumentos utilizados : Telescopio Schmidt-Cassegrain 200mm f/10, Cámara fotográfica Minolta con Telezoom 210mm f/4.5, Película 1600 ASA color, Telescopio Refractor 80mm a f/15

Conductivity Probe

Science.gov (United States)

2008-01-01

The Thermal and Electrical Conductivity Probe (TECP) for NASA's Phoenix Mars Lander took measurements in Martian soil and in the air. The needles on the end of the instrument were inserted into the Martian soil, allowing TECP to measure the propagation of both thermal and electrical energy. TECP also measured the humidity in the surrounding air. The needles on the probe are 15 millimeters (0.6 inch) long. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

Astronaut James Lovell checks body temperature with oral temperature probe

Science.gov (United States)

1965-01-01

Gemini 7 pilot Astronaut James A. Lovell Jr. has temperature check with oral temperature probe attached to his space suit during final preflight preparations for the Gemini 7 space mission. The temperature probe allows doctors to monitor astronauts body temperature at any time during the mission.

Laser-pump/X-ray-probe experiments with electrons ejected from a Cu(111) target: space-charge acceleration.

Science.gov (United States)

Schiwietz, G; Kühn, D; Föhlisch, A; Holldack, K; Kachel, T; Pontius, N

2016-09-01

A comprehensive investigation of the emission characteristics for electrons induced by X-rays of a few hundred eV at grazing-incidence angles on an atomically clean Cu(111) sample during laser excitation is presented. Electron energy spectra due to intense infrared laser irradiation are investigated at the BESSY II slicing facility. Furthermore, the influence of the corresponding high degree of target excitation (high peak current of photoemission) on the properties of Auger and photoelectrons liberated by a probe X-ray beam is investigated in time-resolved pump and probe measurements. Strong electron energy shifts have been found and assigned to space-charge acceleration. The variation of the shift with laser power and electron energy is investigated and discussed on the basis of experimental as well as new theoretical results.

Is a linear probe helpful in diagnosing diseases of pulmonary interstitial spaces?

Directory of Open Access Journals (Sweden)

Natalia Buda

2017-06-01

Full Text Available In a lung ultrasound examination, interstitial lung lesions are visible as numerous B-line artifacts, and are best recorded with the use of a convex probe. Interstitial lung lesions may result from many conditions, including cardiogenic pulmonary oedema, non-cardiogenic pulmonary oedema, or interstitial lung disease. Hence difficulties in the differential diagnostics of the above clinical conditions. This article presents cases of patients suffering from interstitial lung lesions discovered in the course of lung ultrasound examination. The patients were examined with a 3.5–5.0 MHz convex probe and a 7.0–11.0 MHz linear probe. Ultrasound images have been analysed, and differences in the imaging with both probes in patients with interstitial lung lesions have been detailed. The use of a linear probe in patients with interstitial lung lesions (discovered with a convex or a micro-convex probe provides additional information on the source of the origin of the lesions.

The Van Allen Probes mission

CERN Document Server

Burch, James

2014-01-01

This collection of articles provides broad and detailed information about NASA’s Van Allen Probes (formerly known as the Radiation Belt Storm Probes) twin-spacecraft Earth-orbiting mission. The mission has the objective of achieving predictive understanding of the dynamic, intense, energetic, dangerous, and presently unpredictable belts of energetic particles that are magnetically trapped in Earth’s space environment above the atmosphere. It documents the science of the radiation belts and the societal benefits of achieving predictive understanding. Detailed information is provided about the Van Allen Probes mission design, the spacecraft, the science investigations, and the onboard instrumentation that must all work together to make unprecedented measurements within a most unforgiving environment, the core of Earth’s most intense radiation regions.
 This volume is aimed at graduate students and researchers active in space science, solar-terrestrial interactions and studies of the up...

Surface-sensitive conductivity measurement using a micro multi-point probe approach

DEFF Research Database (Denmark)

Perkins, Edward; Barreto, Lucas; Wells, Justin

2013-01-01

An instrument for microscale electrical transport measurements in ultra-high vacuum is presented. The setup is constructed around collinear lithographically-created multi-point probes with a contact spacing down to 500 nm. Most commonly, twelve-point probes are used. These probes are approached...... measurements with an equidistant four-point probe for a wide range of contact spacings. In this way, it is possible to distinguish between bulk-like and surface-like conduction. The paper describes the design of the instrument and the approach to data and error analysis. Application examples are given...

Neutron-based portable drug probe

International Nuclear Information System (INIS)

Womble, P. C.; Vourvopoulos, G.; Ball Howard, J.; Paschal, J.

1999-01-01

Based on previous measurements, a probe prototype for contraband detection utilizing the neutron technique of Pulsed Fast-Thermal Neutron Analysis (PFTNA) is being constructed. The prototype weighs less than 45 kg and is composed of a probe (5 cm diameter), a power pack and a data acquisition and display system. The probe is designed to be inserted in confined spaces such as the boiler of a ship or a tanker truck filled with liquid. The probe provides information on a) the elemental content, and b) the density variations of the interrogated object. By measuring elemental content, the probe can differentiate between innocuous materials and drugs. Density variations can be found through fast neutron transmission. In all cases, hidden drugs are identified through the measurement of the elemental content of the object, and the comparison of expected and measured elemental ratios

Very High Specific Energy, Medium Power Li/CFx Primary Battery for Launchers and Space Probes

Science.gov (United States)

Brochard, Paul; Godillot, Gerome; Peres, Jean Paul; Corbin, Julien; Espinosa, Amaya

2014-08-01

Benchmark with existing technologies shows the advantages of the lithium-fluorinated carbon (Li/CFx) technology for use aboard future launchers in terms of a low Total Cost of Ownership (TCO), especially for high energy demanding missions such as re-ignitable upper stages for long GTO+ missions and probes for deep space exploration.This paper presents the new results obtained on this chemistry in terms of electrical and climatic performances, abuse tests and life tests. Studies - co-financed between CNES and Saft - looked at a pure CFx version with a specific energy up to 500 Wh/kg along with a medium power of 80 to 100 W/kg.

The Interstellar Ethics of Self-Replicating Probes

Science.gov (United States)

Cooper, K.

Robotic spacecraft have been our primary means of exploring the Universe for over 50 years. Should interstellar travel become reality it seems unlikely that humankind will stop using robotic probes. These probes will be able to replicate themselves ad infinitum by extracting raw materials from the space resources around them and reconfiguring them into replicas of themselves, using technology such as 3D printing. This will create a colonising wave of probes across the Galaxy. However, such probes could have negative as well as positive consequences and it is incumbent upon us to factor self-replicating probes into our interstellar philosophies and to take responsibility for their actions.

Study of the 2H(p,γ)3He reaction in the Big Bang Nucleosynthesis energy range at LUNA

Science.gov (United States)

Mossa, Viviana

2018-01-01

Deuterium is the first nucleus produced in the Universe, whose accumulation marks the beginning of the so called Big Bang Nucleosynthesis (BBN). Its primordial abundance is very sensitive to some cosmological parameters like the baryon density and the number of the neutrino families. Presently the main obstacle to an accurate theoretical deuterium abundance evaluation is due to the poor knowledge of the 2H(p,γ)3He cross section at BBN energies. The aim of the present work is to describe the experimental approach proposed by the LUNA collaboration, whose goal is to measure, with unprecedented precision, the total and the differential cross section of the reaction in the 30 < Ec.m. [keV] < 300 energy range.

Probing planetary pollution from space

International Nuclear Information System (INIS)

Fishman, J.

1991-01-01

This paper will review the data sets obtained from instruments that have measured carbon monoxide and tropospheric ozone from space. In addition, an example of the capability of Differential Absorption Lidar (DIAL) systems will be shown and the current plans for monitoring pollution from spaceborne platforms will be discussed. As a result of these studies, scientists now know that pollution is a widespread phenomenon that has impacted the composition of the atmosphere on continental and hemispheric scales. Such perturbations will have far-reaching consequences for global atmospheric chemistry and climate. New measurement techniques using active remote sensors have already produced exciting data sets from aircraft platforms, and should provide an entirely new capability when used from space sometime in the 21st century

Scanning vector Hall probe microscopy

International Nuclear Information System (INIS)

Cambel, V.; Gregusova, D.; Fedor, J.; Kudela, R.; Bending, S.J.

2004-01-01

We have developed a scanning vector Hall probe microscope for mapping magnetic field vector over magnetic samples. The microscope is based on a micromachined Hall sensor and the cryostat with scanning system. The vector Hall sensor active area is ∼5x5 μm 2 . It is realized by patterning three Hall probes on the tilted faces of GaAs pyramids. Data from these 'tilted' Hall probes are used to reconstruct the full magnetic field vector. The scanning area of the microscope is 5x5 mm 2 , space resolution 2.5 μm, field resolution ∼1 μT Hz -1/2 at temperatures 10-300 K

Probes, Moons, and Kinetic Plasma Wakes

Science.gov (United States)

Hutchinson, I. H.; Malaspina, D.; Zhou, C.

2017-10-01

Nonmagnetic objects as varied as probes in tokamaks or moons in space give rise to flowing plasma wakes in which strong distortions of the ion and electron velocity distributions cause electrostatic instabilities. Non-linear phenomena such as electron holes are then produced. Historic probe theory largely ignores the resulting unstable character of the wake, but since we can now simulate computationally the non-linear wake phenomena, a timely challenge is to reassess the influence of these instabilities both on probe measurements and on the wakes themselves. Because the electron instability wavelengths are very short (typically a few Debye-lengths), controlled laboratory experiments face serious challenges in diagnosing them. That is one reason why they have long been neglected as an influence in probe interpretation. Space-craft plasma observations, by contrast, easily obtain sub-Debye-length resolution, but have difficulty with larger-scale reconstruction of the plasma spatial variation. In addition to surveying our developing understanding of wakes in magnetized plasmas, ongoing analysis of Artemis data concerning electron holes observed in the solar-wind lunar wake will be featured. Work partially supported by NASA Grant NNX16AG82G.

Radial space potential measurements in the central cell of the tandem mirror experiment with a heavy-ion-beam probe

Energy Technology Data Exchange (ETDEWEB)

Hallock, G.A.

1983-04-11

Spatial and temporal profiles of the space potential in the central-cell midplane of TMX have been obtained with a heavy-ion-beam probe. The absolute accuracy of measurements is +- 25 volts (with respect to the machine vacuum walls) with a resolution of approx. 2 volts. During moderate fueling with the gas boxes (i/sub gas/ approx. = 1200 Atom-Amperes D/sub 2/), the plasma potential is parabolic to at least 25 cm radius, with phi/sub e/ approx. = phi/sub max/(1-(r/32)/sup 2/) and 300 < phi/sub max/ <450 volts. With puffer-valve fueling, the space potential is relatively flat to at least 27 cm radius, with 250 < phi/sub e/ < 350 volts.

Radial space potential measurements in the central cell of the tandem mirror experiment with a heavy-ion-beam probe

International Nuclear Information System (INIS)

Hallock, G.A.

1983-01-01

Spatial and temporal profiles of the space potential in the central-cell midplane of TMX have been obtained with a heavy-ion-beam probe. The absolute accuracy of measurements is +- 25 volts (with respect to the machine vacuum walls) with a resolution of approx. 2 volts. During moderate fueling with the gas boxes (i/sub gas/ approx. = 1200 Atom-Amperes D 2 ), the plasma potential is parabolic to at least 25 cm radius, with phi/sub e/ approx. = phi/sub max/[1-(r/32) 2 ] and 300 < phi/sub max/ <450 volts. With puffer-valve fueling, the space potential is relatively flat to at least 27 cm radius, with 250 < phi/sub e/ < 350 volts

LECTURA DEL GUIÓN VIAJE A LA LUNA DE FEDERICO GARCÍA LORCA Y DE LA ADAPTACIÓN FÍLMICA DE FREDERIC AMAT

OpenAIRE

Roca Leiva,Macarena

2010-01-01

El presente estudio establece las divergencias producidas en la recepción del guión Viaje a la luna (1929) de Federico García Lorca y la adaptación cinematográfica realizada por Frederic Amat (1998). Tanto el guión como la película presentan disparidades en su actualización, debido a las diferencias entre lector y observador, desplazamientos que serán analizados a partir de los conceptos esenciales de la teoría de la lectura de W. Iser y los niveles estructurales de R. Barthes.

An experimental study of simultaneous ablation with dual probes in radiofrequency thermal ablation

International Nuclear Information System (INIS)

Jang, Il Soo; Rhim, Hyun Chul; Koh, Byung Hee; Cho, On Koo; Seo, Heung Suk; Kim, Yong Soo; Kim, Young Sun; Heo, Jeong Nam

2003-01-01

To determine the differences between sequential ablation with a single probe and simultaneous ablation with dual probes. Using two 14-gauge expandable probes (nine internal prongs with 4-cm deployment), radiofrequency was applied sequentially (n=8) or simultaneously (n=8) to ten ex-vivo cow livers. Before starting ablation, two RF probes with an inter-probe space of 2 cm (n=8) or 3 cm (n=8) were inserted. In the sequential group, switching the connecting cable to an RF generator permitted ablation with the second probe just after ablation with the first probe had finished. In the simultaneous group, single ablation was performed only after connecting the shafts of both RF probes using a connection device. Each ablation lasted 7 minutes at a target temperature of 105-110 .deg. C. The size and shape of the ablated area, and total ablation time were then compared between the two groups. With 2-cm spacing, the group, mean length and overlapping width of ablated lesions were, respectively, 5.20 and 5.05 cm in the sequential group (n=4), and 5.81 and 5.65 cm in the simultaneous group (n=4). With 3-cm spacing, the corresponding figures were 4.99 and 5.60 cm in the sequential group (n=4), and 6.04 and 6.78 cm in the simultaneous group (n=4). With 2-cm spacing, the mean depth of the proximal waist was 0.58 cm in the sequential (group and 0.28 cm in the simultaneous group, while with 3-cm spacing, the corresponding figures were 1.65 and 1.48 cm. In neither group was there a distal waist. Mean total ablation time was 23.4 minutes in the sequential group and 14 minutes in the simultaneous group. In terms of ablation size and ablation time, simultaneous radiofrequency ablation with dual probes is superior to sequential ablation with a single probe. A simultaneous approach will enable an operator to overcome difficulty in probe repositioning during overlapping ablation, resulting in complete ablation with a successful safety margin

Solar Probe: Humanity's First Visit to a Star

Science.gov (United States)

Hassler, D. M.; Solar Probe Science; Technology Definition Team

Solar Probe will experience first hand the processes and conditions in the solar atmosphere that ultimately impact our planet and shape the harsh solar system environment It will be humanity s first visit to a star and will explore a previously inaccessible region of the inner heliosphere The 2003 Space Science Enterprise Strategy called for study of a Solar Probe to fly through the solar atmosphere to answer fundamental questions that can be answered in no other way The mission received highest priority in the National Academy of Sciences decadal research strategy in solar and space physics in 2002 Significant advances have been made in the areas of solar and solar wind science instrument technology mission resources and the mission environment since the previous Solar Probe Science Definition Team reports of 1989 1995 and 1999 The 2004-05 Solar Probe Science and Technology Definition Team STDT recently completed a detailed study of the Solar Probe Mission based on an earliest launch date of October 2014 The report and its Executive Summary were published by NASA in September 2005 and can be found at the website http solarprobe gsfc nasa gov This talk provides an overview of the Solar Probe mission and a summary of the efforts of the STDT

Space engineering

Science.gov (United States)

Alexander, Harold L.

1991-01-01

Human productivity was studied for extravehicular tasks performed in microgravity, particularly including in-space assembly of truss structures and other large objects. Human factors research probed the anthropometric constraints imposed on microgravity task performance and the associated workstation design requirements. Anthropometric experiments included reach envelope tests conducted using the 3-D Acoustic Positioning System (3DAPS), which permitted measuring the range of reach possible for persons using foot restraints in neutral buoyancy, both with and without space suits. Much neutral buoyancy research was conducted using the support of water to simulate the weightlessness environment of space. It became clear over time that the anticipated EVA requirement associated with the Space Station and with in-space construction of interplanetary probes would heavily burden astronauts, and remotely operated robots (teleoperators) were increasingly considered to absorb the workload. Experience in human EVA productivity led naturally to teleoperation research into the remote performance of tasks through human controlled robots.

Space, time, matter

CERN Document Server

Weyl, Hermann

1922-01-01

Excellent introduction probes deeply into Euclidean space, Riemann's space, Einstein's general relativity, gravitational waves and energy, and laws of conservation. "A classic of physics." - British Journal for Philosophy and Science.

Development of the temperature measurement device for the positive ion insensitive to the probe contamination

International Nuclear Information System (INIS)

Minami, Shigeyuki; Tsutsumi, Shiro; Takeya, Yoshio

1978-01-01

The contamination effect to the d.c. probe in the plasma diagnostics is quite serious in the low density plasma. It causes the distortion or hysterisis curves on the probe characteristics. In order to escape it, for the Langmuir probe measurements, methods of high speed sweeping of probe voltage and using the cleaned probe are reported. In this paper, we dealed with the results of experimental examinations of the possibilities and the limitation of the application of above sweeping to the ion temperature measurement. The essential difficulties of the ion parameter measurements to the d.c. probe of the electrons that very small signal currents and the strong capacitance of the electrodes makes the large time constant, is solved by the use of the neutralization circuits. By this neutralization, high speed voltage sweeping can be possible, and high time resolution of the parameters can be obtained. Using this merits, when the probe is boarded on the space craft, this high space resolution of this probe has additive merits about the possibilities of the aspect measurements of plasma flow and the probe. It is concluded that the high scan rate ion trap is useful of the space craft to the erronious probing by the use of uncleaned probe. (author)

Influence of unharmonic changes of plasma potential on the Langmuir probe characteristics for a grounded probe

International Nuclear Information System (INIS)

Surda, V.

1990-01-01

A theory is presented of the deformation of Langmuir probe characteristics by the presence of a.c. plasma potential oscillations at the space charge layer around the probe, making allowance for the fundamental frequency and the second harmonic. It is applicable particularly to the determination of the electron temperature in actual high-frequency discharges with a Maxwellian electron energy distribution. The effect of an a.c. signal on the ion current is also treated. (author). 8 figs., 14 refs

Probing of flowing electron plasmas

International Nuclear Information System (INIS)

Himura, H.; Nakashima, C.; Saito, H.; Yoshida, Z.

2001-01-01

Probing of streaming electron plasmas with finite temperature is studied. For the first time, a current-voltage characteristic of an electric probe is measured in electron plasmas. Due to the fast flow of the electron plasmas, the characteristic curve spreads out significantly and exhibits a long tail. This feature can be explained calculating the currents collected to the probe. In flowing electron plasmas, the distribution function observed in the laboratory frame is non-Maxwellian even if the plasmas come to a state of thermal equilibrium. Another significant feature of the characteristic is that it determines a floating potential where the current equals zero, despite there being very few ions in the electron plasma. A high impedance probe, which is popularly used to determine the space potential of electron plasmas, outputs the potential. The method is available only for plasmas with density much smaller than the Brillouin limit

Scanning probe microscopy experiments in microgravity

International Nuclear Information System (INIS)

Drobek, Tanja; Reiter, Michael; Heckl, Wolfgang M.

2004-01-01

The scanning probe microscopy setups are small, lightweight and do not require vacuum or high voltage supply. In addition, samples can be investigated directly without further preparation. Therefore, these techniques are well-suited for applications in space, in particular, for operation on the International Space Station (ISS) or for high resolution microscopy on planetary missions. A feasibility study for a scanning tunneling microscopy setup was carried out on a parabolic flight campaign in November 2001 in order to test the technical setup for microgravity applications. With a pocket-size design microscope, a graphite surface was imaged under ambient conditions. Atomic resolution was achieved although the quality of the images was inferior in comparison to laboratory conditions. Improvements for future scanning probe microscopy experiments in microgravity are suggested

Resonance strengths in the {sup 17,18}O(p, α){sup 14,15}N reactions and background suppression underground. Commissioning of a new setup for charged-particle detection at LUNA

Energy Technology Data Exchange (ETDEWEB)

Bruno, C.G.; Scott, D.A.; Aliotta, M.; Davinson, T.; Griffin, C.J. [University of Edinburgh, SUPA, School of Physics and Astronomy, Edinburgh (United Kingdom); Formicola, A.; Best, A.; Junker, M. [Laboratori Nazionali del Gran Sasso, INFN, Assergi (Italy); Anders, M.; Bemmerer, D.; Szuecs, T. [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden (Germany); Broggini, C.; Menegazzo, R. [INFN, Padova (Italy); Caciolli, A.; Depalo, R. [INFN, Padova (Italy); Universita di Padova, Dipartimento di Fisica e Astronomia, Padova (Italy); Cavanna, F.; Corvisiero, P.; Prati, P. [INFN, Genova (Italy); Dipartimento di Fisica, Universita di Genova, Genova (Italy); Di Leva, A.; Imbriani, G. [Universita di Napoli ' ' Federico II' ' , Dipartimento di Scienze Fisiche, Napoli (Italy); Elekes, Z.; Fueloep, Zs.; Gyuerky, Gy.; Somorjai, E. [MTA Atomki, Institute of Nuclear Research, Debrecen (Hungary); Gervino, G. [Universita degli Studi di Torino, Dipartimento di Fisica Sperimentale, Torino (Italy); Guglielmetti, A.; Trezzi, D. [Universita degli Studi di Milano (Italy); INFN, Milano (Italy); Gustavino, C. [INFN, Roma (Italy); Napolitani, E. [Universita di Padova, Dipartimento di Fisica e Astronomia, Padova (Italy); Straniero, O. [Laboratori Nazionali del Gran Sasso, INFN, Assergi (Italy); Osservatorio Astronomico di Collurania, Teramo (Italy); Strieder, F. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Collaboration: LUNA Collaboration

2015-08-15

We report on measurements of resonance strengths and energies for the E{sub p} = 151 and 193 keV resonances in the {sup 18}O(p, α){sup 15}N and {sup 17}O(p, α){sup 14}N reactions, respectively, obtained during commissioning of a new setup for alpha-particle detection studies at the LUNA underground laboratory. Our values, ωγ(151) = 164.2 ± 0.9{sub stat-11.7}{sup +12.1}{sub syst} meV and ωγ (193) = 1.68 ± 0.03{sub stat} ± 0.12{sub syst} meV, are in excellent agreement with those reported in the literature. New values of resonance energies are E{sub p} = 151.2 ± 0.3 keV and E{sub p} = 194.8 ± 0.3 keV, respectively, this latter with the highest precision to date. Comparative background measurements in silicon detectors overground and underground were also carried out, yielding up to a factor of 15 in background suppression at LUNA at energies around 200 keV. This clearly demonstrates the usefulness of underground measurements in charged-particles experiments, especially at low detection energies. (orig.)

Las residencias Moches: un primer análisis de la sintaxis espacial en las huacas del Sol y de la Luna, Perú

Directory of Open Access Journals (Sweden)

Castillo Luján, Feren Alexard

2015-12-01

Full Text Available This paper presents a first approximation obtained from the use of space syntax in residential households in the ancient Moche city (s. VII-IX AD. Studies in the site of Temples of the Sun and Moon have elucidated that during the last centuries of occupation, the theocratic system collapsed and a change began towards a new political and ideological system by the new ruling elites. The analyses have allowed us to understand the logic of built space in three households’ complex and show a high understanding of hierarchy and spatial distribution by its former inhabitants. Obviously, the use of Archaeology of architecture in societies like the Moche requires more studies, because these households have very complex internal divisions, where the spatial unit does not always work independently, but in many cases are linked with other constituting a complex functional space.Este trabajo muestra las primeras aproximaciones obtenidas del uso de la sintaxis espacial en viviendas del tipo residencial en la antigua ciudad Moche (s. VII-IX d. C.. Los estudios realizados en el sitio de huacas del Sol y de la Luna han permitido entender que durante los últimos siglos de ocupación, el sistema teocrático colapsó y se inició un cambio hacia un nuevo sistema político e ideológico por parte de las nuevas elites gobernantes. Los análisis realizados han permitido entender la lógica del espacio construido en tres viviendas complejas y que muestran un alto entendimiento de jerarquía y distribución espacial por parte de sus antiguos habitantes. Evidentemente el uso de la Arqueología de la Arquitectura en sociedades como la Moche necesita mayores estudios, puesto que, estas viviendas presentan divisiones internas muy complejas, donde la unidad espacial no siempre funciona de manera independiente, sino que en muchos casos se articulan con otras constituyendo un espacio funcional complejo.

Sub-micron opto-chemical probes for studying living neurons

Science.gov (United States)

Hossein-Zadeh, M.; Delgado, J.; Schweizer, F.; Lieberman, R.

2017-02-01

We have fabricated sub-micron opto-chemical probes for pH, oxygen and calcium monitoring and demonstrated their application in intracellular and extracellular monitoring of neurons (cortical neuronal cultures and acute hippocampal slices). Using these probes, we have measured extracellular pH in the stratum radiatum of the CA1 region of mouse hippocampus upon stimulation of presynaptic Schaffer collateral axons. Synaptic transmission was monitored using standard electrophysiological techniques. We find that the local pH transiently changes in response to synaptic stimulation. In addition, the geometry of the functionalized region on the probe combined with high sensitivity imaging enables simultaneous monitoring of spatially adjacent but distinct compartments. As proof of concept we impaled cultured neurons with the probe measured calcium and pH inside as well as directly outside of neurons as we changed the pH and calcium concentration in the physiological solution in the perfusion chamber. As such these probes can be used to study the impact of the environment on both cellular and extra-cellular space. Additionally as the chemical properties of the surrounding medium can be controlled and monitored with high precision, these probes enable differential measurement of the target parameter referenced to a stable bath. This approach eliminates the uncertainties associated with non-chemical fluctuations in the fluorescent emission and result in a self-calibrated opto-chemical probe. We have also demonstrated multifunctional probes that are capable of measuring up to three parameters in the extracellular space in brain slices.

Isotropic Broadband E-Field Probe

Directory of Open Access Journals (Sweden)

Béla Szentpáli

2008-01-01

Full Text Available An E-field probe has been developed for EMC immunity tests performed in closed space. The leads are flexible resistive transmission lines. Their influence on the field distribution is negligible. The probe has an isotropic reception from 100 MHz to 18 GHz; the sensitivity is in the 3 V/m–10 V/m range. The device is an accessory of the EMC test chamber. The readout of the field magnitude is carried out by personal computer, which fulfils also the required corrections of the raw data.

Preliminary results of a gamma-ray burst study in the Konus experiment on the Venera-11 and Venera-12 space probes

International Nuclear Information System (INIS)

Mazets, Y.P.; Golentskii, S.V.; Ilinskii, V.N.; Panov, V.N.; Aptekar, R.L.

Twenty-one gamma-ray bursts and 68 solar flares in the hard X-ray range were detected on Venera-11 and Venera-12 space probes during the initial 50-day observation period. Major characteristics of the equipment used and preliminary data on the temporal structure and energy spectra of the gamma-ray bursts are considered. The pattern of gamma-ray burst frequency distribution vs. intensity, N(S), is established

Correlation of propagation characteristics of solar cosmic rays detected onboard the spatially separated space probes Mars-7 and Prognoz-3

International Nuclear Information System (INIS)

Gombosi, T.; Somogyi, A.J.; Kolesov, G.Ya.; Kurt, V.G.; Kuzhevskii, B.M.; Logachev, Yu.I.; Savenko, I.A.

1977-01-01

Solar flare generated particle fluxes during the period 3-5 November, 1973 are analysed using the data of the Mars 7 and Prognoz-3 spacecrafts. The intensity profiles registrated onboard these satellites were quite similar, although the space probes were spatially separated by 0.3 AU. The general characteristics of the event can well be understood in terms of the effect of a corotating streat-stream interaction region on the general behaviour of energetic charged particles. (author)

Project for the Space Science in Moscow State University of Geodesy and Cartography (MIIGAiK)

Science.gov (United States)

Semenov, M.; Oberst, J.; Malinnikov, V.; Shingareva, K.; Grechishchev, A.; Karachevtseva, I.; Konopikhin, A.

2012-04-01

Introduction: Based on the proposal call of the Government of Russian Federation 40 of international scientists came to Russia for developing and support-ing research capabilities of national educational institutions. Moscow State University of Geodesy and Cartography (MIIGAiK) and invited scientist Prof. Dr. Jurgen Oberst were awarded a grant to establish a capable research facility concerned with Planetary Geodesy, Cartography and Space Exploration. Objectives: The goals of the project are to build laboratory infrastructure, and suitable capability for MIIGAiK to participate in the planning, execution and analyses of data from future Russian planetary mis-sions and also to integrate into the international science community. Other important tasks are to develop an attractive work place and job opportunities for planetary geodesy and cartography students. For this purposes new MIIGAiK Extraterrestrial Laboratory (MExLab) was organized. We involved professors, researchers, PhD students in to the projects of Moon and planets exploration at the new level of Russian Space Science development. Main results: MExLab team prepare data for upcom-ing Russian space missions, such as LUNA-GLOB and LUNA-RESOURSE. We established cooperation with Russian and international partners (IKI, ESA, DLR, and foreign Universities) and actively participated in international conferences and workshops. Future works: For the future science development we investigated the old Soviet Archives and received the access to the telemetry data of the Moon rovers Lunokhod-1 and Lunokhod-2. That data will be used in education purposes and could be the perfect base for the analysis, development and support in new Russian and international missions and especially Moon exploration projects. MExLab is open to cooperate and make the consortiums for science projects for the Moon and planets exploration. Acknowledgement: Works are funded by the Rus-sian Government (Project name: "Geodesy, cartography and the

The TMX heavy ion beam probe

International Nuclear Information System (INIS)

Hallock, G.A.

1994-01-01

A heavy ion beam probe has been used to measure the radial space potential distribution in the central cell of TMX. This was the first beam probe system to utilize computer control, CAMAC instrumentation, and fast time response for broadband fluctuation capabilities. The fast time response was obtained using off-line processing of the energy analyzer detector signals and wideband transimpedance amplifiers. The on-axis space potential was found to be 300--400 V, with φ e /T ec ∼8. The radial potential profile is parabolic when gas box fueling is used. The frequency of observed fluctuations was found to agree with the E x B plasma rotation frequency during the discharge. The measured Tl ++ secondary ion current level is consistent with calculations, given reasonable assumptions for beam attenuation

Validation of double Langmuir probe in-orbit performance onboard a nano-satellite

Science.gov (United States)

Tejumola, Taiwo Raphael; Zarate Segura, Guillermo Wenceslao; Kim, Sangkyun; Khan, Arifur; Cho, Mengu

2018-03-01

Many plasma measurement systems have been proposed and used onboard different satellites to characterize space plasma. Most of these systems employed the technique of Langmuir probes either using the single or double probes methods. Recent growth of lean satellites has positioned it on advantage to be used for space science missions using Langmuir probes because of its simplicity and convenience. However, single Langmuir probes are not appropriate to be used on lean satellites because of their limited conducting area which leads to spacecraft charging and drift of the instrument's electrical ground during measurement. Double Langmuir probes technique can overcome this limitation, as a measurement reference in relation to the spacecraft is not required. A double Langmuir probe measurement system was designed and developed at Kyushu Institute of Technology for HORYU-IV satellite, which is a 10 kg, 30 cm cubic class lean satellite launched into Low Earth Orbit on 17th February 2016. This paper presents the on-orbit performance and validation of the double Langmuir probe measurement using actual on-orbit measured data and computer simulations.

Tools to probe the universe

International Nuclear Information System (INIS)

Lagage, P.O.; Augueres, J.L.; Amiaux, J.; Cara, Ch.; Fontignie, J.; Rio, Y.; Fermon, C.; Pannetier-Lecoeur, M.; De Vismes, A.; Cordier, B.; Fesquet, M.; Ferrando, Ph.; Authier, M.; Pantin, E.; Glicenstein, J.F.; Boulade, O.; Refregier, A.; Stolarczyk, Th.; Agnese, P.; Rodriguez, L.; Agnese, P.; Pigot, C.; Duband, L.; Limousin, O.; Delagnes, E.; Turck-Chieze, S.; Carton, P.H.; Starck, J.L.; Bournaud, F.; Teyssier, R.; Audit, E.; Brun, A.S.; Leca, P.; Menache, Ch.; Pomarede, D.; Thooris, B.; Meis, C.

2009-01-01

This special issue of Clefs CEA journal is entirely devoted to astrophysics and to the exploration and probing of the Universe. The second part of this dossier, described here, makes a status of the tools used to probe the universe: telescopes, imaging spectrometers, data processing and simulation. Content: A - Telescopes of the future: 1. Seeing further out: JWST: looking back on a past 13 billion years old, Space specifics: the learning curve to know-how, Fabricating a corona-graph mask, SVOM, a satellite to detect the explosions of the first stars to be formed in the Universe; 2. Seeing more precisely: SIMBOL-X, pioneering formation flying, ELT/METIS, a 42-meter giant, One hundred telescopes for the CTA arrays; 3. Seeing wider: Euclid, mapping the extragalactic sky, ANTARES: the neutrino, another cosmic messenger; B - The new generation of imaging spectrometers: Observing the Universe in the submillimeter spectral region, The X-ray Universe, Space cryo-coolers, Out in the extreme, tumultuous Universe, Probing the Sun with GOLF-NG, Focus: From light to imagery; C - Data analysis in astrophysics; D - Numerical simulation in astrophysics: Information technology and theoretical predictions in astrophysics, Supercomputers for a better understanding of the Universe, The visualization of astrophysical simulations, Godunov, a numerical platform for education and research

Gravitational wave as probe of superfluid dark matter

Science.gov (United States)

Cai, Rong-Gen; Liu, Tong-Bo; Wang, Shao-Jiang

2018-02-01

In recent years, superfluid dark matter (SfDM) has become a competitive model of emergent modified Newtonian dynamics (MOND) scenario: MOND phenomenons naturally emerge as a derived concept due to an extra force mediated between baryons by phonons as a result of axionlike particles condensed as superfluid at galactic scales; Beyond galactic scales, these axionlike particles behave as normal fluid without phonon-mediated MOND-like force between baryons, therefore SfDM also maintains the usual success of Λ CDM at cosmological scales. In this paper, we use gravitational waves (GWs) to probe the relevant parameter space of SfDM. GWs through Bose-Einstein condensate (BEC) could propagate with a speed slightly deviation from the speed-of-light due to the change in the effective refractive index, which depends on the SfDM parameters and GW-source properties. We find that Five hundred meter Aperture Spherical Telescope (FAST), Square Kilometre Array (SKA) and International Pulsar Timing Array (IPTA) are the most promising means as GW probe of relevant parameter space of SfDM. Future space-based GW detectors are also capable of probing SfDM if a multimessenger approach is adopted.

Pico Reentry Probes: Affordable Options for Reentry Measurements and Testing

Science.gov (United States)

Ailor, William H.; Kapoor, Vinod B.; Allen, Gay A., Jr.; Venkatapathy, Ethiraj; Arnold, James O.; Rasky, Daniel J.

2005-01-01

It is generally very costly to perform in-space and atmospheric entry experiments. This paper presents a new platform - the Pico Reentry Probe (PREP) - that we believe will make targeted flight-tests and planetary atmospheric probe science missions considerably more affordable. Small, lightweight, self-contained, it is designed as a "launch and forget" system, suitable for experiments that require no ongoing communication with the ground. It contains a data recorder, battery, transmitter, and user-customized instrumentation. Data recorded during reentry or space operations is returned at end-of-mission via transmission to Iridium satellites (in the case of earth-based operations) or a similar orbiting communication system for planetary missions. This paper discusses possible applications of this concept for Earth and Martian atmospheric entry science. Two well-known heritage aerodynamic shapes are considered as candidates for PREP: the shape developed for the Planetary Atmospheric Experiment Test (PAET) and that for the Deep Space II Mars Probe.

Microfour-point probe for studying electronic transport through surface states

DEFF Research Database (Denmark)

Petersen, Christian Leth; Grey, Francois; Shiraki, I.

2000-01-01

Microfour-point probes integrated on silicon chips have been fabricated with probe spacings in the range 4-60 mum. They provide a simple robust device for electrical transport measurements at surfaces, bridging the gap between conventional macroscopic four-point probes and scanning tunneling...... transport through surface states, which is not observed on the macroscopic scale, presumably due to scattering at atomic steps. (C) 2000 American Institute of Physics....

Three-way flexible cantilever probes for static contact

International Nuclear Information System (INIS)

Wang, Fei; Petersen, Dirch H; Hansen, Christian; Mortensen, Dennis; Friis, Lars; Hansen, Ole; Jensen, Helle V

2011-01-01

In micro four-point probe measurements, three-way flexible L-shaped cantilever probes show significant advantages over conventional straight cantilever probes. The L-shaped cantilever allows static contact to the sample surface which reduces the frictional wear of the cantilever tips. We analyze the geometrical design space that must be fulfilled for the cantilevers to obtain static contact with the test sample. The design space relates the spring constant tensor of the cantilevers to the minimal value of the static tip-to-sample friction coefficient. Using an approximate model, we provide the analytical calculation of the compliance matrix of the L-shaped cantilever. Compared to results derived from finite element model simulations, the theoretical model provides a good qualitative analysis while deviations for the absolute values are seen. From a statistical analysis, the deviation is small for cantilevers with low effective spring constants, while the deviation is significant for large spring constants where the quasi one-dimensional approximation is no longer valid

Preliminary Geophysical Survey for Assessing the Geotechnical Conditions and Geohazards at Huaca de La Luna, Peru

Science.gov (United States)

Zavala, G. J.; Lopez, S.; Ebinger, C. J.; Pando, M. A.; Lambert, C.; Morales, R.; Uceda, S.; Perucchio, R.; Castaneda, B.; Aguilar, R.

2014-12-01

This paper presents results of near surface geophysical tests to help assess the geotechnical conditions of the archaeological complex of Huaca de la Luna located near the coastal city of Trujillo, Peru. This area of Peru has experienced damaging earthquakes and tsunamis in historic time. The huaca complex is a massive adobe temple progressively built by the Moche civilization from 100 AD to 650 AD. The geophysical tests carried out included Ground Penetrating Radar (GPR), magnetic gradiometer, and Multichannel Analysis of Surface Waves (MASW) to help assess geotechnical conditions such as buried cavities and hallways, thickness and elastic properties of sand sediments, and the depth to the underlying granitic bedrock. The tests were performed to help with the investigation of structural damage observed along a massive adobe wall (north façade) which has shown signs of distress including fissures, settlements, and other damage. The geophysical results together with detailed Lidar surveying are being used as part of this investigation and highlight the usefulness of these non-destructive techniques for archaeological and historical sites.

Imaging optical probe for pressurized steam-water environment

International Nuclear Information System (INIS)

Donaldson, M.R.; Pulfrey, R.E.

1979-01-01

An air-cooled imaging optical probe, with an outside diameter of 25.4 mm, has been developed to provide high resolution viewing of flow regimes in a steam-water environment at 343 0 C and 15.2 MPa. The design study considered a 3-m length probe. A 0.3-m length probe prototype was fabricated and tested. The optical probe consists of a 3.5-mm diameter optics train surrounded by two coaxial coolant flow channels and two coaxial insulating dead air spaces. With air flowing through the probe at 5.7 g/s, thermal analysis shows that no part of the optics train will exceed 93 0 C when a 3-m length probe is immersed in a 343 0 C environment. Computer stress analysis plus actual tests show that the probe can operate successfully with conservative safety factors. The imaging optical probe was tested five times in the design environment at the semiscale facility at the INEL. Two-phase flow regimes in the high temperature, high pressure, steam-water blowdown and reflood experiments were recorded on video tape for the first time with the imaging optical probe

Cronología radiocarbónica de Las Lunas (Yuncler, Toledo, un gran poblado de fines de la Prehistoria en la Meseta Sur

Directory of Open Access Journals (Sweden)

Urbina Martinez, Dionisio

2013-12-01

Full Text Available We present five radiocarbon dates for the Late Bronze and Early Iron Age phases of Las Lunas (Yuncler, Toledo site. Three of them correspond to the initial moments of the settlement –which is associated with an important bronze hoard– and another two to the final moments of the prehistoric occupation of the village. The coincidence of the first three dates allow us to place fairly accurately the bronze hoard in the mid-tenth century BC, providing interesting information for the study of long-distance contacts in the centre of the Iberian Peninsula during this period. The set of dating evidence shows the existence of large sites in a cultural horizon after Cogotas I and before the Early Iron Age. This horizon is virtually unknown in the region.Presentamos cinco fechas radiocarbónicas correspondientes a las fases del Bronce Final e inicios de la Edad del Hierro del asentamiento de Las Lunas (Yuncler, Toledo. Tres de ellas corresponden a los momentos iniciales del poblamiento y se asocian con un destacado depósito de objetos de bronce. Las otras dos remiten a los momentos finales de la ocupación prehistórica del poblado. La coincidencia de las tres primeras fechas sitúa con bastante exactitud la deposición del conjunto metálico a mediados del siglo X a.C., aportando nueva información para el estudio de los contactos a larga distancia de la población del centro de la Península Ibérica durante este período. El conjunto de dataciones evidencia que ya había poblados de gran extensión en un horizonte cultural posterior a Cogotas I y anterior al Hierro I. Este horizonte es prácticamente desconocido en la región.

Venus Interior Probe Using In-situ Power and Propulsion (VIP-INSPR), Phase I

Data.gov (United States)

National Aeronautics and Space Administration — We envision a novel architecture for Venus Interior Probes based on in-situ resources for power generation (VIP-INSPR). Proposed Venus probe is based on the...

Theoretical analysis of a dual-probe scanning tunneling microscope setup on graphene.

Science.gov (United States)

Settnes, Mikkel; Power, Stephen R; Petersen, Dirch H; Jauho, Antti-Pekka

2014-03-07

Experimental advances allow for the inclusion of multiple probes to measure the transport properties of a sample surface. We develop a theory of dual-probe scanning tunneling microscopy using a Green's function formalism, and apply it to graphene. Sampling the local conduction properties at finite length scales yields real space conductance maps which show anisotropy for pristine graphene systems and quantum interference effects in the presence of isolated impurities. Spectral signatures in the Fourier transforms of real space conductance maps include characteristics that can be related to different scattering processes. We compute the conductance maps of graphene systems with different edge geometries or height fluctuations to determine the effects of nonideal graphene samples on dual-probe measurements.

Preliminary results of the Vega-1 and Vega-2 space probes rendezvous with the Halley comet

International Nuclear Information System (INIS)

Anon.

1986-01-01

Preliminary results of the Halley comet investigation using the Vega-1 and Vega-2 space probes which passed on the 6th and 9th of March, 1986 the comet nucleus at a distance of 9000 and 8200 respectively, are presented. The comet nucleus appeared to be one of the darkest bodies of the Solar system: its albedo is just about 4%. The IR spectrum analysis has shown, that water and carbon dioxide appear to be the main components of the comet material. Mass analysis points out to the presence in the comet dust of iron, oxygen and silicon. It is ascertained, that about 30 t of water vapors and about 5-10 t of dust are evaporated from the comet nucleus surface in one second. Solar wind interaction with the comet streched atmosphere was investigated

Technology Development and Demonstration Concepts for the Space Elevator

Science.gov (United States)

Smitherman, David V., Jr.

2004-01-01

space elevator systems in general; and that the critical technologies required for the Earth to GEO space elevator are not required for similar systems at the Moon, Mars, Europa, or for orbital tether systems at GEO, Luna, and other locations.

Nuclear power in space. Use of reactors and radioactive substances as power sources in satellites and space probes; Kaernkraft i rymden. Anvaendningen av reaktorer och radioaktiva aemnen som kraftkaellor i satelliter och rymdsonder

Energy Technology Data Exchange (ETDEWEB)

Hoestbaeck, Lars

2008-11-15

Today solar panels are the most common technique to supply power to satellites. Solar panels will work as long as the power demand of the satellite is limited and the satellite can be equipped with enough panels, and kept in an orbit that allows enough sunlight to hit the panels. There are various types of space missions that do not fulfil these criteria. With nuclear power these types of missions can be powered regardless of the sunlight and as early as 1961 the first satellite with a nuclear power source was placed in orbit. Out of seventy known space missions that has made use of nuclear power, ten have had some kind of failure. In no case has the failure been associated with the nuclear technology used. This report discusses to what degree satellites with nuclear power are a source for potential radioactive contamination of Swedish territory. It is not a discussion for or against nuclear power in space. Neither is it an assessment of consequences if radioactive material from a satellite would reach the earth's surface. Historically two different kinds of Nuclear Power Sources (NPS) have been used to generate electric power in space. The first is the reactor where the energy is derived from nuclear fission of 235U and the second is the Radioisotope Thermoelectric Generator (RTG) where electricity is generated from the heat of naturally decaying radionuclides. NPS has historically only been used in space by United States and the Soviet Union (and in one failing operation Russia). Nuclear Power Sources have been used in three types of space objects: satellites, space probes and moon/Mars vehicles. USA has launched one experimental reactor into orbit, all other use of NPS by the USA has been RTG:s. The Soviet Union, in contrast, only launched a few RTG:s but nearly forty reactors. The Soviet use of NPS is less transparent than the use in USA and some data published on Soviet systems are more or less well substantiated assessments. It is likely that also future

Trajectory Design for the Lunar Polar Hydrogen Mapper Mission

Science.gov (United States)

Genova, Anthony L.; Dunham, David W.

2017-01-01

The presented trajectory was designed for the Lunar Polar Hydrogen Mapper (LunaH-Map) 6U CubeSat, which was awarded a ride on NASAs Space Launch System (SLS) with Exploration Mission 1 (EM-1) via NASAs 2015 SIMPLEX proposal call. After deployment from EM-1s upper stage (which is planned to enter heliocentric space via a lunar flyby), the LunaH-Map CubeSat will alter its trajectory via its low-thrust ion engine to target a lunar flyby that yields a Sun-Earth-Moon weak stability boundary transfer to set up a ballistic lunar capture. Finally, the orbit energy is lowered to reach the required quasi-frozen science orbit with periselene above the lunar south pole.

Solar Probe Plus: Report of the Science and Technology Definition Team

Science.gov (United States)

2008-01-01

Solar Probe+ will be an extraordinary and historic mission, exploring what is arguably the last region of the solar system to be visited by a spacecraft, the Sun s outer atmosphere or corona as it extends out into space. Approaching as close as 9.5 RS* (8.5 RS above the Sun s surface), Solar Probe+ will repeatedly sample the near-Sun environment, revolutionizing our knowledge and understanding of coronal heating and of the origin and evolution of the solar wind and answering critical questions in heliophysics that have been ranked as top priorities for decades. Moreover, by making direct, in-situ measurements of the region where some of the most hazardous solar energetic particles are energized, Solar Probe+ will make a fundamental contribution to our ability to characterize and forecast the radiation environment in which future space explorers will work and live.

WORKSHOP: Inner space - outer space

International Nuclear Information System (INIS)

Anon.

1984-01-01

During the first week of May, the Fermilab theoretical astrophysics group hosted an international conference on science at the interface of particle physics and cosmology/astrophysics. The conference (Inner Space-Outer Space) was attended by a very diverse group of more than 200 physical scientists, including astronomers, astrophysicists, cosmologists, low-temperature physicists, and elementary particle theorists and experimentalists. The common interest which brought this diverse group to gether is the connection between physics on the smallest scale probed by man - the realm of elementary particle physics - and physics on the largest scale imaginable (the entire Universe) - the realm of cosmology

WORKSHOP: Inner space - outer space

Energy Technology Data Exchange (ETDEWEB)

Anon.

1984-09-15

During the first week of May, the Fermilab theoretical astrophysics group hosted an international conference on science at the interface of particle physics and cosmology/astrophysics. The conference (Inner Space-Outer Space) was attended by a very diverse group of more than 200 physical scientists, including astronomers, astrophysicists, cosmologists, low-temperature physicists, and elementary particle theorists and experimentalists. The common interest which brought this diverse group to gether is the connection between physics on the smallest scale probed by man - the realm of elementary particle physics - and physics on the largest scale imaginable (the entire Universe) - the realm of cosmology.

Small Probes for Orbital Return of Experiments Mission Design

Data.gov (United States)

National Aeronautics and Space Administration — Currently the Georgia Tech Small Probes for Orbital Return of Experiments (SPORE) team is collaborating with Aurora Flight Sciences to provide a launch, re-entry,...

Historical Reveiw of Interstellar Probe Concepts and Examination of Payload Mass Considerations for Different System Architectures

Science.gov (United States)

Long, K.

2017-12-01

The ability to send a space probe beyond the Voyager probes, through the interstellar medium and towardsthe distant stars, has long been the ambition of both the science ction literature but also a small community ofadvocates that have argued for a broader and deeper vision of space exploration that goes outside of our SolarSystem. In this paper we discuss some of the historical interstellar probe concepts which are propelled usingdierent types of propulsion technology, from energetic reaction engines to directed energy beaming, and considerthe payload mass associated with such concepts. We compare and contrast the dierent design concepts, payloadmass fractions, powers and energies and discuss the implications for robotic space exploration within the stellarneighbourhood. Finally, we consider the Breakthrough Starshot initiative, which proposes to send a Gram-scalelaser driven spacecraft to the Alpha Centauri system in a 20 year mission travelling at v 0.2c. We show howthis is a good start in pushing our robotic probes towards interstellar destinations, but also discuss the potentialfor scaling up this systems architecture to missions closer at home, or higher mass missions wider aeld. This is apresentation for the American Geophysical Union at the AGU Fall meeting, New Orleans, 11-15 December 2017,Special Session on the Interstellar Probe Missions.Keywords: Interstellar Probe, Breakthrough Starshot

Gamma Ray Bursts as Cosmological Probes with EXIST

Science.gov (United States)

Hartmann, Dieter; EXIST Team

2006-12-01

The EXIST mission, studied as a Black Hole Finder Probe within NASA's Beyond Einstein Program, would, in its current design, trigger on 1000 Gamma Ray Bursts (GRBs) per year (Grindlay et al, this meeting). The redshift distribution of these GRBs, using results from Swift as a guide, would probe the z > 7 epoch at an event rate of > 50 per year. These bursts trace early cosmic star formation history, point to a first generation of stellar objects that reionize the universe, and provide bright beacons for absorption line studies with groundand space-based observatories. We discuss how EXIST, in conjunction with other space missions and future large survey programs such as LSST, can be utilized to advance our understanding of cosmic chemical evolution, the structure and evolution of the baryonic cosmic web, and the formation of stars in low metallicity environments.

An Adaptive Langmuir Probe for CubeSats and Explorers

Data.gov (United States)

National Aeronautics and Space Administration — We propose to build an Adaptive Langmuir Probe (ALP) for CubeSats designed to mitigate spacecraft charging unique to small platforms. This project builds a new...

Ultrasonic Derivative Measurements of Bone Strain During Exercise, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Luna Innovations, Inc., in collaboration with the SUNY Stony Brook, proposes to extend ultrasonic pulsed phase locked loop (PPLL) derivative measurements to the...

Advanced Technology Cloud Particle Probe for UAS, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — In Phase II SPEC will design, fabricate and flight test a state-of-the-art combined cloud particle probe called the Hawkeye. Hawkeye is the culmination of two...

Rapid In-Place Composite Rotor Damage Detection, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Luna Innovations is proposing to further develop the Rapid In-Place Composite Rotor Damage Detection (RIPCoRDD) System for determining and tracking the structural...

Rapid In-Place Composite Rotor Damage Detection, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Luna Innovations is proposing to develop the Rapid In-Place Composite Rotor Damage Detection (RIPCoRDD) for determining and tracking the structural health of...

Fiber Optic Microcantilever Sensor Coupled with Reactive Polymers for Vapor Phase Detection of Ammonia, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Luna Innovations proposes to adapt its current aqueous-based, fiber-optic microcantilever sensor technology for real-time, monitoring of ammonia in air. Phase I...

X-Ray Diffraction and Fluorescence Instrument for Mineralogical Analysis at the Lunar Surface, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — We propose to develop LUNA, a compact and lightweight X-Ray Diffraction (XRD) / X-Ray Fluorescence (XRF) instrument for mineralogical analysis of regolith, rock...

Ge Quantum Dot Infrared Imaging Camera, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Luna Innovations Incorporated proposes to develop a high performance Ge quantum dots-based infrared (IR) imaging camera on Si substrate. The high sensitivity, large...

High-Frequency Flush Mounted Miniature LOX Fiber-Optic Pressure Sensor II, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Luna Innovations has teamed with the University of Alabama, Huntsville, to develop a miniature flush-mounted fiber-optic pressure sensor that will allow accurate,...

High-Frequency Flush Mounted Miniature LOX Fiber-Optic Pressure Sensor, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Luna Innovations is teaming with the University of Alabama, Huntsville, to develop a miniature flush-mounted fiber-optic pressure sensor that will allow accurate,...

Fiber-Optic Shape Sensing for Intelligent Solar Sail Deployment, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Luna Innovations proposes to develop a distributed fiber-optic shape sensor to provide a control system for the deployment of ultra-lightweight inflatable support...

Direct measurement of surface-state conductance by microscopic four-point probe method

DEFF Research Database (Denmark)

Hasegawa, S.; Shiraki, I.; Tanikawa, T.

2002-01-01

For in situ measurements of local electrical conductivity of well defined crystal surfaces in ultrahigh vacuum, we have developed microscopic four-point probes with a probe spacing of several micrometres, installed in a scanning-electron - microscope/electron-diffraction chamber. The probe...... is precisely positioned on targeted areas of the sample surface by using piezoactuators. This apparatus enables conductivity measurement with extremely high surface sensitivity, resulting in direct access to surface-state conductivity of the surface superstructures, and clarifying the influence of atomic steps...

The Gravity Probe B Flight Dewar

Science.gov (United States)

2001-01-01

Gravity Probe B (GP-B) is the relativity experiment developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. This photograph is of the Gravity Probe B flight dewar, a metal container made like a vacuum bottle that is used especially for storing liquefied gases, that will maintain the experiment at a temperature just above absolute zero, staying cold for two years. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies -- technologies that are already enlivening other branches of science and engineering. Launched in 2004 and managed for NASA by the Marshall Space Flight Center, development of the GP-B is the responsibility of Stanford University, with major subcontractor Lockheed Martin Corporation. (Photo Credit: Lockheed Martin Corporation/R. Underwood)

Heterogeneous Silicon Photonics OFDR Sensing System, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Luna will team with Dr. John Bowers of UCSB to develop an Optical Frequency Domain Reflectometry (OFDR) system-on-chip using heterogeneous silicon photonics to...

Embedded Structural Integrity Sensor, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — In this work Luna Innovations in partnership with Pennsylvania State University proposes to develop a new thermo-ultrasonic technology for the real-time in-situ...

Distributed Anemometry via High-Definition Fiber Optic Sensing, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Luna is developing a distributed anemometer that can directly measure flow field velocity profiles using high-definition fiber optic sensing (HD-FOS). The concept is...

High-Speed Thermal Characterization of Cryogenic Flows, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Luna proposes to continue development on a high-speed fiber optic sensor and readout system for cryogenic temperature measurements in liquid oxygen (LOX) and liquid...

Quantum-Limited Amplifiers for Detector Arrays on NASA's Inflation Probe

Data.gov (United States)

National Aeronautics and Space Administration — Recently, a NASA satellite mission, the Inflation Probe, has been proposed to search for B-mode polarization in the Cosmic Microwave Background (CMB) the "smoking...

Test and Evaluation of Fiber Optic Sensors for High-Radiation Space Nuclear Power Applications

International Nuclear Information System (INIS)

Klemer, Daniel; Fielder, Robert S.; Stinson-Bagby, Kelly L.

2004-01-01

Fiber optic sensors can be used to measure a number of parameters, including temperature, strain, pressure and flow, for instrumentation and control of space nuclear power systems. In the past, this technology has often been rejected for use in such a high-radiation environment based on early experiments that revealed a number of degradation phenomena, including radiation-induced fiber attenuation, or 'graying', and Fiber Bragg Grating (FBG) fading and wavelength shift. However, this paper reports the results of recent experimental testing that demonstrates readability of fiber optic sensors to extremely high levels of neutron and gamma radiation. Both distributed Fiber Bragg Grating (FBG) sensors and single-point Extrinsic Fabry Perot Interferometer (EFPI) sensors were continuously monitored over a 2-month period, during which they were exposed to combined neutron and gamma radiation in both in-core and ex-core positions within a nuclear reactor. Total exposure reached approximately 2 x 10 19 cm -2 fast neutron (E > 1 MeV) fluence and 8.7 x 10 8 Gy gamma for in-core sensors. FBG sensors were interrogated using a standard Luna Innovations FBG measurement system, which is based on optical frequency-domain reflectometer (OFDR) technology. Approximately 74% of the 19 FBG sensors located at the core centerline in the in-core position exhibited sufficient signal-to-noise ratio (SNR) to remain readable even after receiving the maximum dose. EFPI sensors were spectrally interrogated using a broadband probe source operating in the 830 nm wavelength region. While these single-point sensors failed early in the test, important additional fiber spectral transmission data was collected, which indicates that interrogation of EFPI sensors in alternate wavelength regions may allow significant improvement in sensor longevity for operation in high-radiation environments. This work was funded through a Small Business Innovative Research (SBIR) contract with the Nasa Glenn Research

Tribological behavior of micro/nano-patterned surfaces in contact with AFM colloidal probe

International Nuclear Information System (INIS)

Zhang Xiaoliang; Wang Xiu; Kong Wen; Yi Gewen; Jia Junhong

2011-01-01

In effort to investigate the influence of the micro/nano-patterning or surface texturing on the nanotribological properties of patterned surfaces, the patterned polydimethylsiloxane (PDMS) surfaces with pillars were fabricated by replica molding technique. The surface morphologies of patterned PDMS surfaces with varying pillar sizes and spacing between pillars were characterized by atomic force microscope (AFM) and scanning electron microscope (SEM). The AFM/FFM was used to acquire the friction force images of micro/nano-patterned surfaces using a colloidal probe. A difference in friction force produced a contrast on the friction force images when the colloidal probe slid over different regions of the patterned polymer surfaces. The average friction force of patterned surface was related to the spacing between the pillars and their size. It decreased with the decreasing of spacing between the pillars and the increasing of pillar size. A reduction in friction force was attributed to the reduced area of contact between patterned surface and colloidal probe. Additionally, the average friction force increased with increasing applied load and sliding velocity.

Tribological behavior of micro/nano-patterned surfaces in contact with AFM colloidal probe

Energy Technology Data Exchange (ETDEWEB)

Zhang Xiaoliang; Wang Xiu; Kong Wen [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Yi Gewen [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Jia Junhong, E-mail: jhjia@licp.cas.cn [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

2011-10-15

In effort to investigate the influence of the micro/nano-patterning or surface texturing on the nanotribological properties of patterned surfaces, the patterned polydimethylsiloxane (PDMS) surfaces with pillars were fabricated by replica molding technique. The surface morphologies of patterned PDMS surfaces with varying pillar sizes and spacing between pillars were characterized by atomic force microscope (AFM) and scanning electron microscope (SEM). The AFM/FFM was used to acquire the friction force images of micro/nano-patterned surfaces using a colloidal probe. A difference in friction force produced a contrast on the friction force images when the colloidal probe slid over different regions of the patterned polymer surfaces. The average friction force of patterned surface was related to the spacing between the pillars and their size. It decreased with the decreasing of spacing between the pillars and the increasing of pillar size. A reduction in friction force was attributed to the reduced area of contact between patterned surface and colloidal probe. Additionally, the average friction force increased with increasing applied load and sliding velocity.

PROBES, POPULATIONS, SAMPLES, MEASUREMENTS AND RELATIONS IN STEREOLOGY

Directory of Open Access Journals (Sweden)

Robert T Dehoff

2011-05-01

Full Text Available This summary paper provides an overview of the content of stereology. The typical problem at hand centers around some three dimensional object that has an internal structure that determines its function, performance, or response. To understand and quantify the geometry of that structure it is necessary to probe it with geometric entities: points, lines, planes volumes, etc. Meaningful results are obtained only if the set of probes chosen for use in the assessment is drawn uniformly from the population of such probes for the structure as a whole. This requires an understanding of the population of each kind of probe. Interaction of the probes with the structure produce geometric events which are the focus of stereological measurements. In almost all applications the measurement that is made is a simple count of the number of these events. Rigorous application of these requirements for sample design produce unbiased estimates of geometric properties of features in the structure no matter how complex are the features or what their arrangement in space. It is this assumption-free characteristic of the methodology that makes it a powerful tool for characterizing the internal structure of three dimensional objects.

Reading Intermediality: Lorca’s Viaje a la luna (“Journey to the Moon,” 1929 and Un chien andalou (Buñuel/Dalí, 1929

Directory of Open Access Journals (Sweden)

Paul Julian Smith

2014-10-01

Full Text Available This article will treat two experimental short films, the first one of the most famous in cinema history; the second a little known script, lost for many years and brought to the screen only sixty years after it was written. The former is Un chien andalou of 1929, generally attributed to both director Luis Buñuel and Catalan painter Salvador Dalí (who claims first screenwriting credit in the film itself. The latter is Viaje a la luna, written also in 1929 by poet and dramatist Federico García Lorca and filmed by Frederic Amat, a contemporary Catalan painter, in 1998, the centenary of Lorca’s birth. Normal 0 false false false EN-US JA X-NONE

Fiber Optic Shape Sensing for Tethered Marsupial Rovers, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Building upon the successful proof of concept work in Phase I, Luna Innovations Incorporated is proposing to design, build, and test a sensing tether for marsupial...

Measurements of plasma density fluctuations and electric wave fields using spherical electrostatic probes

International Nuclear Information System (INIS)

Eriksson, A.I.; Bostroem, R.

1995-04-01

Spherical electrostatic probes are in wide use for the measurements of electric fields and plasma density. This report concentrates on the measurements of fluctuations of these quantities rather than background values. Potential problems with the technique include the influence of density fluctuations on electric field measurements and vice versa, effects of varying satellite potential, and non-linear rectification in the probe and satellite sheaths. To study the actual importance of these and other possible effects, we simulate the response of the probe-satellite system to various wave phenomena in the plasma by applying approximate analytical as well as numerical methods. We use a set of non-linear probe equations, based on probe characteristics experimentally obtained in space, and therefore essentially independent of any specific probe theory. This approach is very useful since the probe theory for magnetized plasmas is incomplete. 47 refs

ATLAS Probe: Exploring Frontiers in Galaxy Evolution, Cosmology, and Milky Way Science

Science.gov (United States)

Wang, Yun; Robberto, Massimo; Dickinson, Mark; Ferguson, Henry C.; Hillenbrand, Lynne; Hirata, Christopher M.; Cimatti, Andrea; Bartlett, James; Barkhouser, Robert; Benjamin, Robert A.; Brinchmann, Jarle; Chary, Ranga-Ram; Conroy, Charlie; Daddi, Emanuele; Donahue, Megan; Dore, Olivier; Eisenhardt, Peter; Fraser, Wesley C.; Helou, George; Kirkpatrick, J. Davy; Malhotra, Sangeeta; Moscardini, Lauro; Ninkov, Zoran; Ressler, Michael; Rhoads, James; Rhodes, Jason; Shapley, Alice; Smee, Stephen; ATLAS Probe Team

2018-01-01

ATLAS (Astrophysics Telescope for Large Area Spectroscopy) Probe is a concept for a NASA probe-class space mission that leverages WFIRST imaging for targeted spectroscopy. ATLAS Probe will obtain spectra of 90% of all galaxies imaged by the WFIRST High Latitude Survey at z > 0.5, with slit spectra of 300 million galaxies to z = 7. ATLAS Probe and WFIRST together will produce a 3D map of the Universe with Mpc resolution over 2200 sq deg, the definitive data sets for studying galaxy evolution, probing dark matter, dark energy and modification of general relativity, and quantifying the 3D structure and stellar content of the Milky Way.ATLAS Probe science spans four broad categories: (1) Revolutionize galaxy evolution studies by tracing the relation between galaxies and dark matter from the local group to cosmic voids and filaments, from the epoch of reionization through the peak era of galaxy assembly. (2) Open a new window into the Universe by mapping the dark matter filaments using 3D weak lensing with spectroscopic redshifts to unveil the nature of the dark Universe, and obtaining definitive measurements of dark energy and possible modification of general relativity using cosmic large-scale structure. (3) Probe the Milky Way's dust-shrouded regions, reaching the far side of our Galaxy. (4) Characterize asteroids and comets in the outer Solar System.ATLAS Probe is a 1.5m telescope with a field of view (FoV) of 0.4 sq deg, and uses Digital Micromirror Devices (DMDs) as slit selectors. It has a spectroscopic resolution of R = 600, and a wavelength range of 1-4μm. The lack of slit spectroscopy from space over a wide FoV is the obvious gap in current and planned future space missions; ATLAS fills this big gap with an unprecedented spectroscopic capability (with an estimated spectroscopic multiplex factor of 5000-10000). It has an estimated cost under $1B, with a single instrument, a telescope aperture that allows for a lighter launch vehicle, and mature technology

On the retrieval of crystallographic information from atom probe microscopy data via signal mapping from the detector coordinate space.

Science.gov (United States)

Wallace, Nathan D; Ceguerra, Anna V; Breen, Andrew J; Ringer, Simon P

2018-06-01

Atom probe tomography is a powerful microscopy technique capable of reconstructing the 3D position and chemical identity of millions of atoms within engineering materials, at the atomic level. Crystallographic information contained within the data is particularly valuable for the purposes of reconstruction calibration and grain boundary analysis. Typically, analysing this data is a manual, time-consuming and error prone process. In many cases, the crystallographic signal is so weak that it is difficult to detect at all. In this study, a new automated signal processing methodology is demonstrated. We use the affine properties of the detector coordinate space, or the 'detector stack', as the basis for our calculations. The methodological framework and the visualisation tools are shown to be superior to the standard method of crystallographic pole visualisation directly from field evaporation images and there is no requirement for iterations between a full real-space initial tomographic reconstruction and the detector stack. The mapping approaches are demonstrated for aluminium, tungsten, magnesium and molybdenum. Implications for reconstruction calibration, accuracy of crystallographic measurements, reliability and repeatability are discussed. Copyright © 2018 Elsevier B.V. All rights reserved.

Imaging optical probe for pressurized 6200K steam-water environment

International Nuclear Information System (INIS)

Donaldson, M.R.; Pulfrey, R.E.; Merrill, S.K.

1979-01-01

An air-cooled imaging optical probe, 0.3 m long with a 25.4-mm outside diameter, has been built to provide high resolution viewing of flow regimes in a steam-water environment at 620 0 K and 15.5 MPa. The probe consists of a 3.5-mm-diameter rod lens borescope, surrounded by two coaxial coolant flow channels and two coaxial insulating dead air spaces. With air flowing through the probe at 5.7 g/s, thermal analysis shows that no part of the optical borescope will exceed 366 0 K when the probe is immersed in a 620 0 K environment. The objective lens is protected by a sapphire window which tests have shown can survive over 200 hours in 620 0 K water or steam with negligible loss of resolution and contrast. Condensation on the protective window is boiled off by electrically heating the window. Computer stress analysis, plus actual tests, shows that the probe can operate successfully with conservative safety factors

Advanced characterization of carrier profiles in germanium using micro-machined contact probes

DEFF Research Database (Denmark)

Clarysse, T.; Konttinen, M.; Parmentier, B.

2012-01-01

of new concepts based on micro machined, closely spaced contact probes (10 μm pitch). When using four probes to perform sheet resistance measurements, a quantitative carrier profile extraction based on the evolution of the sheet resistance versus depth along a beveled surface is obtained. Considering...... the properties of both approaches on Al+ implants in germanium with different anneal treatments....

Science with the space-based interferometer eLISA. III: probing the expansion of the universe using gravitational wave standard sirens

Energy Technology Data Exchange (ETDEWEB)

Tamanini, Nicola; Caprini, Chiara [Institut de Physique Théorique, CEA-Saclay, CNRS UMR 3681, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France); Barausse, Enrico [Sorbonne Universités, UPMC Université Paris 6, UMR 7095, Institut d' Astrophysique de Paris, 98 bis Bd Arago, 75014 Paris (France); Sesana, Alberto [School of Physics and Astronomy, The University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Klein, Antoine [Department of Physics and Astronomy, The University of Mississippi, University, MS 38677 (United States); Petiteau, Antoine, E-mail: nicola.tamanini@cea.fr, E-mail: chiara.caprini@cea.fr, E-mail: barausse@iap.fr, E-mail: asesana@star.sr.bham.ac.uk, E-mail: aklein@physics.montana.edu, E-mail: antoine.petiteau@apc.univ-paris7.fr [APC, Université Paris Diderot, Observatoire de Paris, Sorbonne Paris Cité, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France)

2016-04-01

We investigate the capability of various configurations of the space interferometer eLISA to probe the late-time background expansion of the universe using gravitational wave standard sirens. We simulate catalogues of standard sirens composed by massive black hole binaries whose gravitational radiation is detectable by eLISA, and which are likely to produce an electromagnetic counterpart observable by future surveys. The main issue for the identification of a counterpart resides in the capability of obtaining an accurate enough sky localisation with eLISA. This seriously challenges the capability of four-link (2 arm) configurations to successfully constrain the cosmological parameters. Conversely, six-link (3 arm) configurations have the potential to provide a test of the expansion of the universe up to z ∼ 8 which is complementary to other cosmological probes based on electromagnetic observations only. In particular, in the most favourable scenarios, they can provide a significant constraint on H{sub 0} at the level of 0.5%. Furthermore, (Ω{sub M}, Ω{sub Λ}) can be constrained to a level competitive with present SNIa results. On the other hand, the lack of massive black hole binary standard sirens at low redshift allows to constrain dark energy only at the level of few percent.

The interactions of the HELIOS probe with the solar wind plasma

International Nuclear Information System (INIS)

Voigt, G.H.; Isensee, U.; Maassberg, H.

1981-08-01

HELIOS solar probe disturbs the solar wind plasma in the near vicinity. Around the probe, a space charge cloud is formed due to strong photoelectron emission and fade out of solar wind particles. The conducting and isolating parts of the surface are differently charged. These effects result in a very complex potential structure in the vicinity of the probe and on the surface. The interactions of the HELIOS probe with the solar wind plasma are described by models based on kinetic theory of plasma. The combination of these models yields an entire and consistent representation of the spacecraft charging and the potential structure. Electron spectra measured by plasma experiment E1 are analysed and compared with results of the theoretical models. (orig.) [de

Dual-probe near-field fiber head with gap servo control for data storage applications.

Science.gov (United States)

Fang, Jen-Yu; Tien, Chung-Hao; Shieh, Han-Ping D

2007-10-29

We present a novel fiber-based near-field optical head consisting of a straw-shaped writing probe and a flat gap sensing probe. The straw-shaped probe with a C-aperture on the end face exhibits enhanced transmission by a factor of 3 orders of magnitude over a conventional fiber probe due to a hybrid effect that excites both propagation modes and surface plasmon waves. In the gap sensing probe, the spacing between the probe and the disk surface functions as an external cavity. The high sensitivity of the output power to the change in the gap width is used as a feedback control signal. We characterize and design the straw-shaped writing probe and the flat gap sensing probe. The dual-probe system is installed on a conventional biaxial actuator to demonstrate the capability of flying over a disk surface with nanometer position precision.

Probing early universe cosmology and high energy physics through space-borne interferometers

International Nuclear Information System (INIS)

Ungarelli, C.; Vecchio, A.

2001-01-01

We discuss the impact of space-borne laser interferometric experiments operating in the low-frequency window (∼ 1 μHz - 1 Hz), with the goal of identifying the fundamental issues that regard the detection of a primordial background of GW predicted by slow-roll inflationary models, corresponding to h 100 2 Ω ∼ 10 -16 - 10 -15 . We analyse the capabilities of the planned single-instrument LISA mission and the sensitivity improvements that could be achieved by cross-correlating the data streams from a pair of detectors of the LISA-class. We show that the two-detectors configuration is extremely powerful, and leads to the detection of a stochastic background as weak as h 100 2 Ω ∼ 10 -14 . However, such instrumental sensitivity cannot be exploited to achieve a comparable performance for the detection of the primordial component of the background, due to the overwhelming power of the stochastic signal produced by short-period solar-mass binary systems of compact objects, that cannot be resolved as individual sources. We estimate that the primordial background can be detected only if its fractional energy density h 100 2 Ω is greater than a few times 10 -12 . The key conclusion of our analysis is that the typical mHz frequency band, regardless of the instrumental noise level, is the wrong observational window to probe slow-roll inflationary models. We discuss possible follow-on missions with optimal sensitivity in the ∼ μHz-regime and/or in the ∼ 0.1Hz-band specifically aimed at gravitational wave cosmology. (author)

Thin Cu film resistivity using four probe techniques: Effect of film thickness and geometrical shapes

Science.gov (United States)

Choudhary, Sumita; Narula, Rahul; Gangopadhyay, Subhashis

2018-05-01

Precise measurement of electrical sheet resistance and resistivity of metallic thin Cu films may play a significant role in temperature sensing by means of resistivity changes which can further act as a safety measure of various electronic devices during their operation. Four point probes resistivity measurement is a useful approach as it successfully excludes the contact resistance between the probes and film surface of the sample. Although, the resistivity of bulk samples at a particular temperature mostly depends on its materialistic property, however, it may significantly differ in the case of thin films, where the shape and thickness of the sample can significantly influence on it. Depending on the ratio of the film thickness to probe spacing, samples are usually classified in two segments such as (i) thick films or (ii) thin films. Accordingly, the geometric correction factors G can be related to the sample resistivity r, which has been calculated here for thin Cu films of thickness up to few 100 nm. In this study, various rectangular shapes of thin Cu films have been used to determine the shape induced geometric correction factors G. An expressions for G have been obtained as a function of film thickness t versus the probe spacing s. Using these expressions, the correction factors have been plotted separately for each cases as a function of (a) film thickness for fixed linear probe spacing and (b) probe distance from the edge of the film surface for particular thickness. Finally, we compare the experimental results of thin Cu films of various rectangular geometries with the theoretical reported results.

Validating experimental and theoretical Langmuir probe analyses

Science.gov (United States)

Pilling, L. S.; Carnegie, D. A.

2007-08-01

Analysis of Langmuir probe characteristics contains a paradox in that it is unknown a priori which theory is applicable before it is applied. Often theories are assumed to be correct when certain criteria are met although they may not validate the approach used. We have analysed the Langmuir probe data from cylindrical double and single probes acquired from a dc discharge plasma over a wide variety of conditions. This discharge contains a dual-temperature distribution and hence fitting a theoretically generated curve is impractical. To determine the densities, an examination of the current theories was necessary. For the conditions where the probe radius is the same order of magnitude as the Debye length, the gradient expected for orbital-motion limited (OML) is approximately the same as the radial-motion gradients. An analysis of the 'gradients' from the radial-motion theory was able to resolve the differences from the OML gradient value of two. The method was also able to determine whether radial or OML theories applied without knowledge of the electron temperature, or separation of the ion and electron contributions. Only the value of the space potential is necessary to determine the applicable theory.

Causality and associative holography of time-and-space domain events

International Nuclear Information System (INIS)

Rebane, Aleksander

2014-01-01

We consider reference-free associative recall of time-and-space domain holograms of arbitrary non-stationary optical object amplitudes or events. We show that if the probe fragment correlates with the recorded event either in space or in time coordinates or in both, then the hologram faithfully reproduces those missing parts (sub-events) that occur simultaneously or later in time with respect to the probe fragment. However, if a missing sub-event occurred before the fragment used as associative probe, then the hologram will not play this information back due to the time arrow imposed by causality. (paper)

Dr. Harry Whelan With the Light Emitting Diode Probe

Science.gov (United States)

1999-01-01

The red light from the Light Emitting Diode (LED) probe shines through the fingers of Dr. Harry Whelan, a pediatric neurologist at the Children's Hospital of Wisconsin in Milwaukee. Dr. Whelan uses the long waves of light from the LED surgical probe to activate special drugs that kill brain tumors. Laser light previously has been used for this type of surgery, but the LED light illuminates through all nearby tissues, reaching parts of tumors that shorter wavelengths of laser light carnot. The new probe is safer because the longer wavelengths of light are cooler than the shorter wavelengths of laser light, making the LED less likely to injure normal brain tissue near the tumor. Also, it can be used for hours at a time while still remaining cool to the touch. The probe was developed for photodynamic cancer therapy under a NASA Small Business Innovative Research Program grant. The program is part of NASA's Technology Transfer Department at the Marshall Space Flight Center.

The space adventure comes to a conference at CERN

CERN Multimedia

CERN Bulletin

2012-01-01

From 5 to 7 November, CERN will host the 4th International Conference on Particle and Fundamental Physics in Space (SpacePart12). Special talks open to the general public will be given by two of the biggest names in space exploration: Edward Stone, project scientist for the Voyager probes, and William Gerstenmaier, former Manager of the International Space Station (ISS) programme.     Launched at Isola d’Elba (Italy) in 2002, then continued in Washington D.C. (USA) in 2003 and Beijing (China) in 2006, the SpacePart conferences are an opportunity for researchers and space policy makers from across the world to exchange opinions on the developments of space-related science and technology programmes. This year, SpacePart coincides with the centenary of the discovery of cosmic rays and will be held at CERN. On 5 November, Edward Stone, professor at the California Institute of Technology and project scientist for the Voyager probes since 1972, will give a talk on the extraordin...

Fácies Orgânica da Formação La Luna, Bacia do Valle Superior del Magdalena, Colômbia:Implicações para a Geração de Petróleo e Caracterização Paleoambiental.

Directory of Open Access Journals (Sweden)

Juliana Andrade Iemini

2007-08-01

Full Text Available Upper Cretaceous pelitic rocks generate most of the oil reserves in Colombia. In Del Magdalena Upper Valley (MUV, the existenceof good quality outcrops and thermal evolution levels that vary from immaturity to the end of the oil generation “window” makes it one of themost appropriate regions for the study of primary migration and generation of oil in Upper Cretaceous. The main objectives of this work wereto study the organic facies of La Luna Formation in an outcrop section called Riacho Bambuca (Bambuca Creek, determine the oil generationpotential and characterize the paleoenvironment. For this research, 24 samples were used in palynofacies analysis (characterization ofthe kerogen components assembly and in organic geochemistry analysis (Total Organic Carbon – TOC analysis and Rock-Eval pyrolysis,provided by Colombia Oil Institute – ECOPETROL. The palynofacies analysis included the use of microscopy techniques (transmitted whitelight and incident blue light. Furthermore, a Spore Coloration Index (SCI analysis was made in order to determine the thermal maturationstage. The studied material was composed mainly of an amorphous organic substance, with its fluorescent coloration varying from yellow tobright orange. The palynomorph group is represented by spore morph and dinoflagellate cysts. The ligneous material are present in very lowpercentages; they are mainly opaque phytoclasts. The results of geochemical analysis showed TOC contents ranging from medium to high,excellent potential for the generation of hydrocarbons (PG > 4 mg HC/g of rock, hydrogen index ranging from 329 to 589 mg HC/g, andlow values of oxygen index, characterizing type II kerogen. The low degree of thermal maturation was determined by Spore Coloration Indexvalues ranging from 2,5 to 3,0, Tmax values below 440°C and Hydrocarbon Production Index inferior to 0,2. According to the organic faciesdata, La Luna Formation deposited in a marine environment with facies from

Jumbo Space Environment Simulation and Spacecraft Charging Chamber Characterization

Science.gov (United States)

2015-04-09

probes for Jumbo. Both probes are produced by Trek Inc. Trek probe model 370 is capable of -3 to 3kV and has an extremely fast, 50µs/kV response to...changing surface potentials. Trek probe 341B is capable of -20 to 20kV with a 200 µs/kV response time. During our charging experiments the probe sits...unlimited. 12 REFERENCES [1] R. D. Leach and M. B. Alexander, "Failures and anomalies attributed to spacecraft charging," NASA RP-1375, Marshall Space

NAMMA TWO-DIMENSIONAL STEREO PROBE AND CLOUD PARTICLE IMAGER V1

Data.gov (United States)

National Aeronautics and Space Administration — This Cloud Microphysics dataset consists of data from two probes used to measure the size, shape, and concentration of cloud particles; the two-dimensional stereo...

A record of long- and short-term environmental and climatic change during OAE3: La Luna Formation, Late Cretaceous (Santonian-early Campanian), Venezuela

Science.gov (United States)

Rey, O.; Simo (Toni), J. A.; Lorente, M. A.

2004-08-01

The La Luna Formation was deposited under anoxic/dysoxic conditions in a tropical epicontinental sea on the northwest South America margin. Sedimentological, micropaleontological and geochemical evidence provides insights into factors that influenced the sedimentation and controlled the accumulation of organic-rich deposits at decimeter and meter scales during the youngest of the Cretaceous oceanic anoxic events (OAE). The La Luna Formation consists of an alternation of black marlstones interbedded with black limestones and black marly limestones. The benthic foraminifera assemblages indicate sedimentation in the upper neritic to upper bathyal environment. These rocks contain large amounts of organic matter. It is interpreted that a combination of warm global and rainy climate and the presence of bathymetric barriers caused poor circulation and low rates of water column ventilation during a high sea level in the early Santonian leading to the preservation of carbon-rich deposits in this region. During the late Santonian, a cooling-trend in global climate increased wind strength and upwelling; this change probably reduced runoff causing a weakening of the pycnocline and destabilized the stratification in the water column providing a progressive increase in oxygen in the water column and on the sea floor and a decrease in total organic carbon preservation in a shallower basin. These changes and the establishment of full mid- and deep-water exchange in response to the deepening and widening of the Equatorial Atlantic Gateway could have been important mechanisms for ending the epeiric sea anoxia. Changes through time in the vanadium-nickel fraction, planktonic and benthic foraminifera assemblages, productivity proxy elements, and lithological characteristics support this model. Superimposed on the general trend, variations in calcium carbonate and total organic carbon percentages at the scale of tens of centimeters reveal high frequency cyclic variations, which

RESULTS OF THE EXAMINATION OF ELECTROCHEMICAL NOISE PROBE SPECIMENS REMOVED FROM TANK 241-AN-107, JUNE, 2010

International Nuclear Information System (INIS)

Cooke, G.A.; Wyrwas, R.B.; Duncan, J.B.

2010-01-01

An Integrated Multi-function Corrosion Probe (IMCP) was installed in Tank 241-AN-107 on September 20, 2006. A portion of the probe was retrieved on June 8, 2010 and the sections holding the detectors were delivered to the 222-S Laboratory for analysis. The examination and disassembly of the probe sections encountered a number of challenges. However, disassembly and relevant analyses were successfully completed. The following summarizes our observations. Brittle failure of the fiberglass probe in the middle of detector 2 resulted in the recovery of only three vapor space C-rings and six supernatant bullet specimens. The design of the bullets and how they were attached to the probe made the recovery of the components more difficult. The use of glue/epoxy on the bullets and the attachment of the flat bottom of the bullets to the curved surface of the fiberglass probe body meant that weight loss on cleaning and surface area of the specimens could not be determined with acceptable accuracy. Macrophotography of all specimens reveals that corrosion was slight in the vapor space and extremely slight in the supernatant. The one pre-cracked C-ring recovered from the vapor space still had the stress bulge visible on the polished surface, indicating that crack propagation had not occurred in the tank. No photographs were taken of the C-ring before deployment. No further analysis was conducted on this specimen. A detailed discussion and photographic documentation are provided in this report.

Estudio crítico de los índices de severidad y la superficie afectada por el incendio de Sierra de Luna (Zaragoza

Directory of Open Access Journals (Sweden)

R. Guillem-Cogollos

2017-12-01

Full Text Available Para la determinación del área quemada y la severidad asociada del incendio de Sierra de Luna (Zaragoza, ocurrido el 4 de julio de 2015, se han calculado tres índices espectrales derivados de Landsat-8: NDVI, NBR y BAI. Comparando los resultados obtenidos por cada uno de ellos, en un incendio con extensas zonas de cultivo entre zonas arboladas, se ha determinado que la combinación de ΔNBR y BAI mejora sustancialmente la determinación del área realmente quemada, tanto en su perímetro exterior como en las zonas aisladas no quemadas de su interior. Para el cálculo de la severidad, se propone una metodología basada en el análisis de las diferencias de NBR, antes y después del incendio, y su combinación con el BAI, en función del valor previo al incendio de los índices NBR y de NDVI.

Micro-four-point probes in a UHV scanning electron microscope for in-situ surface-conductivity measurements

DEFF Research Database (Denmark)

Shiraki, I.; Nagao, T.; Hasegawa, S.

2000-01-01

For in-situ measurements of surface conductivity in ultrahigh vacuum (UHV), we have installed micro-four-point probes (probe spacings down to 4 mum) in a UHV scanning electron microscope (SEM) combined with scanning reflection-high-energy electron diffraction (RHEED). With the aid of piezoactuators...

Detection of Active Topology Probing Deception

Science.gov (United States)

2015-09-01

the probing host and day, which contain traceroute data across all /24 prefixes in the routed IPv4 address space. Luckie [21] designed Scam - per to be...1 0 4067 0 0 0 0 1 69 THIS PAGE INTENTIONALLY LEFT BLANK 70 List of References [1] ATIS Committee PRQC. (2015). ATIS Telecom Glossary. [ Online ...Werber. (2013, Feb). Star Wars Traceroute. [ Online ]. Available: http: //beaglenetworks.net/post/42707829171/star-wars-traceroute [4] (2015). Virtual

High-spatial-resolution electron density measurement by Langmuir probe for multi-point observations using tiny spacecraft

Science.gov (United States)

Hoang, H.; Røed, K.; Bekkeng, T. A.; Trondsen, E.; Clausen, L. B. N.; Miloch, W. J.; Moen, J. I.

2017-11-01

A method for evaluating electron density using a single fixed-bias Langmuir probe is presented. The technique allows for high-spatio-temporal resolution electron density measurements, which can be effectively carried out by tiny spacecraft for multi-point observations in the ionosphere. The results are compared with the multi-needle Langmuir probe system, which is a scientific instrument developed at the University of Oslo comprising four fixed-bias cylindrical probes that allow small-scale plasma density structures to be characterized in the ionosphere. The technique proposed in this paper can comply with the requirements of future small-sized spacecraft, where the cost-effectiveness, limited space available on the craft, low power consumption and capacity for data-links need to be addressed. The first experimental results in both the plasma laboratory and space confirm the efficiency of the new approach. Moreover, detailed analyses on two challenging issues when deploying the DC Langmuir probe on a tiny spacecraft, which are the limited conductive area of the spacecraft and probe surface contamination, are presented in the paper. It is demonstrated that the limited conductive area, depending on applications, can either be of no concern for the experiment or can be resolved by mitigation methods. Surface contamination has a small impact on the performance of the developed probe.

Conceptual design of a Langmuir probe system for the tokamak ASDEX-UPGRADE

International Nuclear Information System (INIS)

Anastassiadis, A.; Tsingas, A.C.; Tsois, N.N.; Zoumbos, G.A.

1985-05-01

The conceptual design of a Langmuir probe system for the tokamak ASDEX-UPG is presented. This system is intended to carry out electrostatic measurements, in space and time, on the boundary layer plasma over the largest possible volume of the divertor plasma during discharges. Conducted by preset design requirements a fast probe system is proposed. During discharges signal measurements will be performed by means of a data-acquisition system and the motion will be controlled by a real-time computer. The desired information concerning plasma parameters and the motion of the probe system will be available to the diagnostician via a video display unit. (author)

Development of a combined OCT-Raman probe for the prospective in vivo clinical melanoma skin cancer screening

Science.gov (United States)

Mazurenka, M.; Behrendt, L.; Meinhardt-Wollweber, M.; Morgner, U.; Roth, B.

2017-10-01

A combined optical coherence tomography (OCT)-Raman probe was designed and built into a spectral domain OCT head, and its performance was evaluated and compared to the most common Raman probe setups, based on a fiber bundle and confocal free space optics. Due to the use of the full field of view of an OCT scanning lens, the combined probe has a superior performance within maximum permissible exposure limits, compared to the other two probes. Skin Raman spectra, recorded in vivo, further prove the feasibility of the OCT-Raman probe for the future in vivo clinical applications in skin cancer screening.

Downhole instrument including a flexible probe which can travel freely around bends in a borehole

International Nuclear Information System (INIS)

Dickinson III, B. W. O.

1985-01-01

Bore hole instrument and methods of manufacturing and using the same. The instrument includes an elongated flexible probe which is inserted into a bore hole and can travel freely around bends of relatively short radius in the hole. The probe includes a plurality of sensors, explosive charges or the like which are spaced apart and embedded in a flexible body comprising a mass of cushioning material, with a flexible outer casing of fabric having a high tensile strength. The probe is driven into a bore hole in piston-like fashion, and the flexible body enables the probe to travel freely around bends of relatively short radius. Instrumentation for processing signals from the probe is located at the surface of the earth, and a flexible cable interconnects the instrumentation with the probe

Gravity Probe B Encapsulated

Science.gov (United States)

2004-01-01

In this photo, the Gravity Probe B (GP-B) space vehicle is being encapsulated atop the Delta II launch vehicle. The GP-B is the relativity experiment developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies that are already enlivening other branches of science and engineering. Launched April 20, 2004 , the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Russ Underwood, Lockheed Martin Corporation).

Probing Higgs-radion mixing in warped models through complementary searches at the LHC and the ILC

Science.gov (United States)

Frank, Mariana; Huitu, Katri; Maitra, Ushoshi; Patra, Monalisa

2016-09-01

We consider the Higgs-radion mixing in the context of warped space extradimensional models with custodial symmetry and investigate the prospects of detecting the mixed radion. Custodial symmetries allow the Kaluza-Klein excitations to be lighter and protect Z b b ¯ to be in agreement with experimental constraints. We perform a complementary study of discovery reaches of the Higgs-radion mixed state at the 13 and 14 TeV LHC and at the 500 and 1000 GeV International Linear Collider (ILC). We carry out a comprehensive analysis of the most significant production and decay modes of the mixed radion in the 80 GeV-1 TeV mass range and indicate the parameter space that can be probed at the LHC and the ILC. There exists a region of the parameter space which can be probed, at the LHC, through the diphoton channel even for a relatively low luminosity of 50 fb-1 . The reach of the four-lepton final state in probing the parameter space is also studied in the context of 14 TeV LHC, for a luminosity of 1000 fb-1 . At the ILC, with an integrated luminosity of 500 fb-1 , we analyze the Z -radion associated production and the W W fusion production, followed by the radion decay into b b ¯ and W+W-. The W W fusion production is favored over the Z -radion associated channel in probing regions of the parameter space beyond the LHC reach. The complementary study at the LHC and the ILC is useful both for the discovery of the radion and the understanding of its mixing sector.

Influence of probe motion on laser probe temperature in circulating blood.

Science.gov (United States)

Hehrlein, C; Splinter, R; Littmann, L; Tuntelder, J R; Tatsis, G P; Svenson, R H

1991-01-01

The purpose of this study was to evaluate the effect of probe motion on laser probe temperature in various blood flow conditions. Laser probe temperatures were measured in an in vitro blood circulation model consisting of 3.2 nm-diameter plastic tubes. A 2.0 mm-diameter metal probe attached to a 300 microns optical quartz fiber was coupled to an argon laser. Continuous wave 4 watts and 8 watts of laser power were delivered to the fiber tip corresponding to a 6.7 +/- 0.5 and 13.2 +/- 0.7 watts power setting at the laser generator. The laser probe was either moved with constant velocity or kept stationary. A thermocouple inserted in the lateral portion of the probe was used to record probe temperatures. Probe temperature changes were found with the variation of laser power, probe velocity, blood flow, and duration of laser exposure. Probe motion significantly reduced probe temperatures. After 10 seconds of 4 watts laser power the probe temperature in stagnant blood decreased from 303 +/- 18 degrees C to 113 +/- 17 degrees C (63%) by moving the probe with a velocity of 5 cm/sec. Blood flow rates of 170 ml/min further decreased the probe temperature from 113 +/- 17 degrees C to 50 +/- 8 degrees C (56%). At 8 watts of laser power a probe temperature reduction from 591 +/- 25 degrees C to 534 +/- 36 degrees C (10%) due to 5 cm/sec probe velocity was noted. Probe temperatures were reduced to 130 +/- 30 degrees C (78%) under the combined influence of 5 cm/sec probe velocity and 170 ml/min blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)

Towards a National Space Weather Predictive Capability

Science.gov (United States)

Fox, N. J.; Ryschkewitsch, M. G.; Merkin, V. G.; Stephens, G. K.; Gjerloev, J. W.; Barnes, R. J.; Anderson, B. J.; Paxton, L. J.; Ukhorskiy, A. Y.; Kelly, M. A.; Berger, T. E.; Bonadonna, L. C. M. F.; Hesse, M.; Sharma, S.

2015-12-01

National needs in the area of space weather informational and predictive tools are growing rapidly. Adverse conditions in the space environment can cause disruption of satellite operations, communications, navigation, and electric power distribution grids, leading to a variety of socio-economic losses and impacts on our security. Future space exploration and most modern human endeavors will require major advances in physical understanding and improved transition of space research to operations. At present, only a small fraction of the latest research and development results from NASA, NOAA, NSF and DoD investments are being used to improve space weather forecasting and to develop operational tools. The power of modern research and space weather model development needs to be better utilized to enable comprehensive, timely, and accurate operational space weather tools. The mere production of space weather information is not sufficient to address the needs of those who are affected by space weather. A coordinated effort is required to support research-to-applications transition efforts and to develop the tools required those who rely on this information. In this presentation we will review the space weather system developed for the Van Allen Probes mission, together with other datasets, tools and models that have resulted from research by scientists at JHU/APL. We will look at how these, and results from future missions such as Solar Probe Plus, could be applied to support space weather applications in coordination with other community assets and capabilities.

A seven harmonic actively compensated Langmuir probe for the GEC Cell

Science.gov (United States)

Goodyear, A.; Nolle, L.; Hopgood, A. A.; Picton, P. D.; Braithwaite, N.

2001-10-01

The uncertainty of Langmuir probe measurements in capacitively coupled discharges depends to a great extent on how well harmonic components in the plasma potential are accounted for. The extent to which individual harmonics distort a probe characteristic has been determined across power and pressure parameter-space in the GEC cell. Langmuir probe current-voltage measurements are distorted by RF components across the probe sheath. A seven harmonic waveform was applied to the probe tip to actively match that generated by the plasma. In some circumstances harmonics above the 3rd contributed RF components of the order of the electron temperature in magnitude. Measurement of the EEDF was found to be particularly sensitive to these components. Optimization of the applied waveform (seven amplitudes and seven phases) was achieved using artificially intelligent control. This is advantageous given the large number of (possibly interacting) parameters and permits tracking of changes in plasma conditions. An algorithm utilizing simulated annealing determines the optimum waveform in a far shorter time than a skilled human operator can.

Behavior of Triple Langmuir Probes in Non-Equilibrium Plasmas

Science.gov (United States)

Polzin, Kurt A.; Ratcliffe, Alicia C.

2018-01-01

The triple Langmuir probe is an electrostatic probe in which three probe tips collect current when inserted into a plasma. The triple probe differs from a simple single Langmuir probe in the nature of the voltage applied to the probe tips. In the single probe, a swept voltage is applied to the probe tip to acquire a waveform showing the collected current as a function of applied voltage (I-V curve). In a triple probe three probe tips are electrically coupled to each other with constant voltages applied between each of the tips. The voltages are selected such that they would represent three points on the single Langmuir probe I-V curve. Elimination of the voltage sweep makes it possible to measure time-varying plasma properties in transient plasmas. Under the assumption of a Maxwellian plasma, one can determine the time-varying plasma temperature T(sub e)(t) and number density n(sub e)(t) from the applied voltage levels and the time-histories of the collected currents. In the present paper we examine the theory of triple probe operation, specifically focusing on the assumption of a Maxwellian plasma. Triple probe measurements have been widely employed for a number of pulsed and timevarying plasmas, including pulsed plasma thrusters (PPTs), dense plasma focus devices, plasma flows, and fusion experiments. While the equilibrium assumption may be justified for some applications, it is unlikely that it is fully justifiable for all pulsed and time-varying plasmas or for all times during the pulse of a plasma device. To examine a simple non-equilibrium plasma case, we return to basic governing equations of probe current collection and compute the current to the probes for a distribution function consisting of two Maxwellian distributions with different temperatures (the two-temperature Maxwellian). A variation of this method is also employed, where one of the Maxwellians is offset from zero (in velocity space) to add a suprathermal beam of electrons to the tail of the

Long-life mission reliability for outer planet atmospheric entry probes

Science.gov (United States)

Mccall, M. T.; Rouch, L.; Maycock, J. N.

1976-01-01

The results of a literature analysis on the effects of prolonged exposure to deep space environment on the properties of outer planet atmospheric entry probe components are presented. Materials considered included elastomers and plastics, pyrotechnic devices, thermal control components, metal springs and electronic components. The rates of degradation of each component were determined and extrapolation techniques were used to predict the effects of exposure for up to eight years to deep space. Pyrotechnic devices were aged under accelerated conditions to an equivalent of eight years in space and functionally tested. Results of the literature analysis of the selected components and testing of the devices indicated that no severe degradation should be expected during an eight year space mission.

New developments at Hunveyor and Husar space probe model constructions in Hungarian Universities and Colleges: status report of 2008

Science.gov (United States)

Hegzi, S.; Bérczi, Sz.; Hudoba, Gy.; Magyar, I.; Lang, A.; Istenes, Z.; Weidinger, T.; Tepliczky, I.; Varga, T.; Hargitai, H.

2008-09-01

Introduction Hunveyor and Husar space probe models are the main school robotics program in Hungary in the last decade initiated by our Cosmic Materials Space research Group (CMSRG). As a new form of planetary science education in Hungary students build their lander and rover robots and test them on test tables, carry out simulations, and go with their instruments to field works of planetary geology analog sites. Recently 10 groups work in this program and here is a status report about the new results. Planetary robot construction and simulations steps We summarized in 10 steps the main "constructional and industrial research and technology" description of planetary material studying and collecting by space probes (landers, rovers). We focused on the activity we began and teach to carry out at those steps. (Main planets considered were the Moon and Mars): 1. Reconnaissance and survey of the surface of a planet by orbital space probes (i.e. Lunar Orbiter, MGS, MRO etc.) Our studies: photogeology, geomorphology, preparations to cartography. 2. Mapping of the surface of the selected planet with geographical and stratigraphical methods. We (CMSRG) prepared thematic maps on Moon, Mercury, Mars, Venus [1] and Atlas (3) in the series [2,3]. 3. Identification of various surface materials by albedo, spectroscopic [4], thermal IR, identification and selection of the target sites. (in terrestrial analog sites during field works) 4. Planning the space probe system lander and rover working together (MPF-Sojourner type assembly). Planning of the Hunveyor and Husar models. 5. Construction and manufacturing lander and rover units. All Hunveyor groups built their models [5]. 6. Launching and traveling the space probes to the planetary surface. (No rocket building, we simulate [6] some events during the voyage only). 7. Measuring the planetary surface environment on the surface of target planet [7]. (CMSRG) groups carry out test-table measurements [8] and simulations, and later they

Supersymmetric probes on the conifold

International Nuclear Information System (INIS)

Arean, Daniel; Crooks, David E.; Ramallo, Alfonso V.

2004-01-01

We study the supersymmetric embeddings of different D-brane probes in the AdS 5 xT 1,1 geometry. The main tool employed is kappa symmetry and the cases studied include D3-, D5- and D7-branes. We find a family of three-cycles of the T 1,1 space over which a D3-brane can be wrapped supersymmetrically and we determine the field content of the corresponding gauge theory duals. Supersymmetric configurations of D5-branes wrapping a two-cycle and of spacetime filling D7-branes are also found. The configurations in which the entire T 1,1 space is wrapped by a D5-brane (baryon vertex) and a D7-brane are also studied. Some other embeddings which break supersymmetry but are nevertheless stable are also determined. (author)

Mastering the Master Space

CERN Document Server

Forcella, Davide; He, Yang-Hui; Zaffaroni, Alberto

2008-01-01

Supersymmetric gauge theories have an important but perhaps under-appreciated notion of a master space, which controls the full moduli space. For world-volume theories of D-branes probing a Calabi-Yau singularity X the situation is particularly illustrative. In the case of one physical brane, the master space F is the space of F-terms and a particular quotient thereof is X itself. We study various properties of F which encode such physical quantities as Higgsing, BPS spectra, hidden global symmetries, etc. Using the plethystic program we also discuss what happens at higher number N of branes. This letter is a summary and some extensions of the key points of a longer companion paper arXiv:0801.1585.

A new planetary mapping for future space missions

Science.gov (United States)

Karachevtseva, Irina; Kokhanov, Alexander; Rodionova, Janna; Zubarev, Anatoliy; Nadezhdina, Irina; Kreslavsky, Mikhail; Oberst, Jürgen

2015-04-01

The wide studies of Solar system, including different planetary bodies, were announced by new Russian space program. Their geodesy and cartography support provides by MIIGAiK Extraterrestrial Laboratory (http://mexlab.miigaik.ru/eng) in frames of the new project "Studies of Fundamental Geodetic Parameters and Topography of Planets and Satellites". The objects of study are satellites of the outer planets (satellites of Jupiter - Europa, Calisto and Ganymede; Saturnine satellite Enceladus), some planets (Mercury and Mars) and the satellites of the terrestrial planets - Phobos (Mars) and the Moon (Earth). The new research project, which started in 2014, will address the following important scientific and practical tasks: - Creating new three-dimensional geodetic control point networks of satellites of the outer planets using innovative photogrammetry techniques; - Determination of fundamental geodetic parameters and study size, shape, and spin parameters and to create the basic framework for research of their surfaces; - Studies of relief of planetary bodies and comparative analysis of general surface characteristics of the Moon, Mars, and Mercury, as well as studies of morphometric parameters of volcanic formations on the Moon and Mars; - Modeling of meteoritic bombardment of celestial bodies and the study of the dynamics of particle emissions caused by a meteorite impacts; - Development of geodatabase for studies of planetary bodies, including creation of object catalogues, (craters and volcanic forms, etc.), and thematic mapping using GIS technology. The significance of the project is defined both by necessity of obtaining fundamental characteristics of the Solar System bodies, and practical tasks in preparation for future Russian and international space missions to the Jupiter system (Laplace-P and JUICE), the Moon (Luna-Glob and Luna-Resource), Mars (Exo-Mars), Mercury (Bepi-Colombo), and possible mission to Phobos (project Boomerang). For cartographic support of

Gravity Probe B data system description

International Nuclear Information System (INIS)

Bennett, Norman R

2015-01-01

The Gravity Probe B data system, developed, integrated, and tested by Lockheed Missiles and Space Company, and later Lockheed Martin Corporation, included flight and ground command, control, and communications software. The development was greatly facilitated, conceptually and by the transfer of key personnel, through Lockheed’s earlier flight and ground test software development for the Hubble Space Telescope (HST). Key design challenges included the tight mission timeline (17 months, 9 days of on-orbit operation), the need to tune the system once on-orbit, and limited 2 Kbps real-time data rates and ground asset availability. The result was a completely integrated space vehicle and Stanford mission operations center, which successfully collected and archived 97% of the ‘guide star valid’ data to support the science analysis. Lessons learned and incorporated from the HST flight software development and on-orbit support experience, and Lockheed’s independent research and development effort, will be discussed. (paper)

Gamma-Ray Imaging Probes.

Science.gov (United States)

Wild, Walter James

1988-12-01

External nuclear medicine diagnostic imaging of early primary and metastatic lung cancer tumors is difficult due to the poor sensitivity and resolution of existing gamma cameras. Nonimaging counting detectors used for internal tumor detection give ambiguous results because distant background variations are difficult to discriminate from neighboring tumor sites. This suggests that an internal imaging nuclear medicine probe, particularly an esophageal probe, may be advantageously used to detect small tumors because of the ability to discriminate against background variations and the capability to get close to sites neighboring the esophagus. The design, theory of operation, preliminary bench tests, characterization of noise behavior and optimization of such an imaging probe is the central theme of this work. The central concept lies in the representation of the aperture shell by a sequence of binary digits. This, coupled with the mode of operation which is data encoding within an axial slice of space, leads to the fundamental imaging equation in which the coding operation is conveniently described by a circulant matrix operator. The coding/decoding process is a classic coded-aperture problem, and various estimators to achieve decoding are discussed. Some estimators require a priori information about the object (or object class) being imaged; the only unbiased estimator that does not impose this requirement is the simple inverse-matrix operator. The effects of noise on the estimate (or reconstruction) is discussed for general noise models and various codes/decoding operators. The choice of an optimal aperture for detector count times of clinical relevance is examined using a statistical class-separability formalism.

Nonlinear realization of supersymmetric AdS space isometries

International Nuclear Information System (INIS)

Clark, T. E.; Love, S. T.

2006-01-01

The isometries of AdS 5 space and supersymmetric AdS 5 xS 1 space are nonlinearly realized on four-dimensional Minkowski space. The resultant effective actions in terms of the Nambu-Goldstone modes are constructed. The dilatonic mode governing the motion of the Minkowski space probe brane into the covolume of supersymmetric AdS 5 space is found to be unstable and the bulk of the AdS 5 space is unable to sustain the brane. No such instability appears in the nonsupersymmetric case

A new Langmuir probe concept for rapid sampling of space plasma electron density

International Nuclear Information System (INIS)

Jacobsen, K S; Pedersen, A; Moen, J I; Bekkeng, T A

2010-01-01

In this paper we describe a new Langmuir probe concept that was invented for the in situ investigation of HF radar backscatter irregularities, with the capability to measure absolute electron density at a resolution sufficient to resolve the finest conceivable structure in an ionospheric plasma. The instrument consists of two or more fixed-bias cylindrical Langmuir probes whose radius is small compared to the Debye length. With this configuration, it is possible to acquire absolute electron density measurements independent of electron temperature and rocket/satellite potential. The system was flown on the ICI-2 sounding rocket to investigate the plasma irregularities which cause HF backscatter. It had a sampling rate of more than 5 kHz and successfully measured structures down to the scale of one electron gyro radius. The system can easily be adapted for any ionospheric rocket or satellite, and provides high-quality measurements of electron density at any desired resolution

GPM GROUND VALIDATION NCAR CLOUD MICROPHYSICS PARTICLE PROBES MC3E V1

Data.gov (United States)

National Aeronautics and Space Administration — The GPM Ground Validation NCAR Cloud Microphysics Particle Probes MC3E dataset was collected during the Midlatitude Continental Convective Clouds Experiment (MC3E),...

Cinco tesis histórico-políticas de Efraín González Luna: inhibición política; régimen; representación; ciudadanía; nación

OpenAIRE

López-Mijares, Antonio

2011-01-01

El autor interpreta el pensamiento de Efraín González Luna mediante el análisis de sus planteamientos sobre inhibición política, régimen político, representación, ciudadanía y nación. Dichos planteamientos incorporan elementos descriptivos y prescriptivos en una explicación coherente de la historia de México, mediante el recurso a las polaridades o antinomias entre los temas "positivos" de su refl exión, como son la representación, la identidad entre nación y Estado, el ejercicio legítimo ...

Numerical model of operation of the Langmuir probe under intermediate pressure

International Nuclear Information System (INIS)

Dudin, S.V.

1996-01-01

The technique of a Langmuir probe is known reasonably well. However, despite plenty of work devoted to calculation of currents on the probe inserted into plasma, a theory does not at present exist which would allow calculation of plasma parameters at any size of the probe and pressure of the working gas. While the theory of a probe in absence of collisions is developed rather in detail by Bernstain and Rabinovich, Laframboise, Allen, and others, there is no rigorous theory which describes a probe under high pressure of a gas. As for intermediate pressure, the theories are absent. Solution of the problem is in this case considerably complicated because of non-local dependence of density of charged particles on potential or electric field strength that means unusability of hydrodynamic approach and necessity of application of the kinetic theory. To fill in this gap the author has developed a numerical model of ion kinetics in a near-boundary layer of a Langmuir probe, inserted into a weakly-ionized gas-discharge plasma, in a range of intermediate pressure of a neutral gas as well as at any ratio between thickness of the layer of space charge and radius of the probe. On the base of results of modeling, practical technique of processing of pore characteristics at intermediate pressure is developed: (i) a technique of calculation of density of ions; (2) a technique of division of a probe current on electron and ion part

A complementary metal-oxide-semiconductor compatible monocantilever 12-point probe for conductivity measurements on the nanoscale

DEFF Research Database (Denmark)

Gammelgaard, Lauge; Bøggild, Peter; Wells, J.W.

2008-01-01

and a probe pitch of 500 nm. In-air four-point measurements have been performed on indium tin oxide, ruthenium, and titanium-tungsten, showing good agreement with values obtained by other four-point probes. In-vacuum four-point resistance measurements have been performed on clean Bi(111) using different probe...... spacings. The results show the expected behavior for bulk Bi, indicating that the contribution of electronic surface states to the transport properties is very small. (C) 2008 American Institute of Physics....

Gravity Probe B Assembled

Science.gov (United States)

2000-01-01

In this photo, the Gravity Probe B (GP-B) space vehicle is being assembled at the Sunnyvale, California location of the Lockheed Martin Corporation. The GP-B is the relativity experiment developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies that are already enlivening other branches of science and engineering. Launched April 20, 2004 , the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Russ Underwood, Lockheed Martin Corporation).

Theory of a spheroidal probe in low-density continuum plasmas

International Nuclear Information System (INIS)

Kamitsuma, M.; Teii, S.

1982-01-01

A spheroidal probe theory for a low-density continuum plasma, i.e., one where the electron density is N/sub e/ 8 cm -3 and the gas pressure is P> or approx. =1 Torr has been developed using a spheroidal coordinate system in order to properly take into account the effect of the finite length of the probe. The numerical results of both the electron- and the ion-current characteristics are obtained for various values of R/sub p//lambda/sub D/ ranging from 0 to 1, epsilon = T/sub i//T/sub e/ from 0.1 to 1, and C/sub p/ = L/sub p//2R/sub p/ from 1 to 100, where lambda/sub D/ is the Debye length, R/sub p/ and L/sub p/ are the probe radius and the probe length, T/sub i/ and T/sub e/ are the ion and the electron temperature, respectively. Using these results, new methods to determine the electron temperature and the plasma space potential (consequently, the electron density) by practical measurements are also proposed and discussed

The Gravity Probe B Experiment

Science.gov (United States)

Kolodziejczak, Jeffrey

2008-01-01

This presentation briefly describes the Gravity Probe B (GP-B) Experiment which is designed to measure parts of Einstein's general theory of relativity by monitoring gyroscope orientation relative to a distant guide star. To measure the miniscule angles predicted by Einstein's theory, it was necessary to build near-perfect gyroscopes that were approximately 50 million times more precise than the best navigational gyroscopes. A telescope mounted along the central axis of the dewar and spacecraft provided the experiment's pointing reference to a guide star. The telescope's image divide precisely split the star's beam into x-axis and y-axis components whose brightness could be compared. GP-B's 650-gallon dewar, kept the science instrument inside the probe at a cryogenic temperature for 17.3 months and also provided the thruster propellant for precision attitude and translation control. Built around the dewar, the GP-B spacecraft was a total-integrated system, comprising both the space vehicle and payload, dedicated as a single entity to experimentally testing predictions of Einstein's theory.

Four-probe measurements with a three-probe scanning tunneling microscope

International Nuclear Information System (INIS)

Salomons, Mark; Martins, Bruno V. C.; Zikovsky, Janik; Wolkow, Robert A.

2014-01-01

We present an ultrahigh vacuum (UHV) three-probe scanning tunneling microscope in which each probe is capable of atomic resolution. A UHV JEOL scanning electron microscope aids in the placement of the probes on the sample. The machine also has a field ion microscope to clean, atomically image, and shape the probe tips. The machine uses bare conductive samples and tips with a homebuilt set of pliers for heating and loading. Automated feedback controlled tip-surface contacts allow for electrical stability and reproducibility while also greatly reducing tip and surface damage due to contact formation. The ability to register inter-tip position by imaging of a single surface feature by multiple tips is demonstrated. Four-probe material characterization is achieved by deploying two tips as fixed current probes and the third tip as a movable voltage probe

Four-probe measurements with a three-probe scanning tunneling microscope

Energy Technology Data Exchange (ETDEWEB)

Salomons, Mark [National Institute for Nanotechnology, National Research Council of Canada, Edmonton, Alberta T6G 2M9 (Canada); Martins, Bruno V. C.; Zikovsky, Janik; Wolkow, Robert A., E-mail: rwolkow@ualberta.ca [National Institute for Nanotechnology, National Research Council of Canada, Edmonton, Alberta T6G 2M9 (Canada); Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1 (Canada)

2014-04-15

We present an ultrahigh vacuum (UHV) three-probe scanning tunneling microscope in which each probe is capable of atomic resolution. A UHV JEOL scanning electron microscope aids in the placement of the probes on the sample. The machine also has a field ion microscope to clean, atomically image, and shape the probe tips. The machine uses bare conductive samples and tips with a homebuilt set of pliers for heating and loading. Automated feedback controlled tip-surface contacts allow for electrical stability and reproducibility while also greatly reducing tip and surface damage due to contact formation. The ability to register inter-tip position by imaging of a single surface feature by multiple tips is demonstrated. Four-probe material characterization is achieved by deploying two tips as fixed current probes and the third tip as a movable voltage probe.

Four-probe measurements with a three-probe scanning tunneling microscope.

Science.gov (United States)

Salomons, Mark; Martins, Bruno V C; Zikovsky, Janik; Wolkow, Robert A

2014-04-01

We present an ultrahigh vacuum (UHV) three-probe scanning tunneling microscope in which each probe is capable of atomic resolution. A UHV JEOL scanning electron microscope aids in the placement of the probes on the sample. The machine also has a field ion microscope to clean, atomically image, and shape the probe tips. The machine uses bare conductive samples and tips with a homebuilt set of pliers for heating and loading. Automated feedback controlled tip-surface contacts allow for electrical stability and reproducibility while also greatly reducing tip and surface damage due to contact formation. The ability to register inter-tip position by imaging of a single surface feature by multiple tips is demonstrated. Four-probe material characterization is achieved by deploying two tips as fixed current probes and the third tip as a movable voltage probe.

Open heavy flavor and other hard probes in ultra-relativistic heavy-ion collisions

OpenAIRE

Uphoff, Jan

2014-01-01

In this thesis hard probes are studied in the partonic transport model BAMPS (Boltzmann Approach to MultiParton Scatterings). Employing Monte Carlo techniques, this model describes the 3+1 dimensional evolution of the quark gluon plasma phase in ultra-relativistic heavy-ion collisions by propagating all particles in space and time and carrying out their collisions according to the Boltzmann equation. Since hard probes are produced in hard processes with a large momentum transfer, the value of...

Precision probes of a leptophobic Z{sup Prime} boson

Energy Technology Data Exchange (ETDEWEB)

Buckley, Matthew R., E-mail: mbuckley@fnal.gov [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Ramsey-Musolf, Michael J. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States)

2012-06-06

Extensions of the Standard Model that contain leptophobic Z{sup Prime} gauge bosons are theoretically interesting but difficult to probe directly in high-energy hadron colliders. However, precision measurements of Standard Model neutral current processes can provide powerful indirect tests. We demonstrate that parity-violating deep inelastic scattering of polarized electrons off of deuterium offer a unique probe leptophobic Z{sup Prime} bosons with axial quark couplings and masses above 100 GeV. In addition to covering a wide range of previously uncharted parameter space, planned measurements of the deep inelastic parity-violating eD asymmetry would be capable of testing leptophobic Z{sup Prime} scenarios proposed to explain the CDF W plus dijet anomaly.

Gravity Probe B spacecraft description

International Nuclear Information System (INIS)

Bennett, Norman R; Burns, Kevin; Katz, Russell; Kirschenbaum, Jon; Mason, Gary; Shehata, Shawky

2015-01-01

The Gravity Probe B spacecraft, developed, integrated, and tested by Lockheed Missiles and Space Company and later Lockheed Martin Corporation, consisted of structures, mechanisms, command and data handling, attitude and translation control, electrical power, thermal control, flight software, and communications. When integrated with the payload elements, the integrated system became the space vehicle. Key requirements shaping the design of the spacecraft were: (1) the tight mission timeline (17 months, 9 days of on-orbit operation), (2) precise attitude and translational control, (3) thermal protection of science hardware, (4) minimizing aerodynamic, magnetic, and eddy current effects, and (5) the need to provide a robust, low risk spacecraft. The spacecraft met all mission requirements, as demonstrated by dewar lifetime meeting specification, positive power and thermal margins, precision attitude control and drag-free performance, reliable communications, and the collection of more than 97% of the available science data. (paper)

Mobile Game Probes

DEFF Research Database (Denmark)

Borup Lynggaard, Aviaja

2006-01-01

This paper will examine how probes can be useful for game designers in the preliminary phases of a design process. The work is based upon a case study concerning pervasive mobile phone games where Mobile Game Probes have emerged from the project. The new probes are aimed towards a specific target...... group and the goal is to specify the probes so they will cover the most relevant areas for our project. The Mobile Game Probes generated many interesting results and new issues occurred, since the probes came to be dynamic and favorable for the process in new ways....

Using Pre-Melted Phase Change Material to Keep Payloads in Space Warm for Hours without Power

Science.gov (United States)

Choi, Michael

2013-01-01

Adding phase change material (PCM) to a mission payload can maintain its temperature above the cold survival limit, without power, for several hours in space. For the International Space Station, PCM is melted by heaters just prior to the payload translation to the worksite when power is available. When power is cut off during the six-hour translation, the PCM releases its latent heat to make up the heat loss from the radiator(s) to space. For the interplanetary Probe, PCM is melted by heaters just prior to separation from the orbiter when power is available from the orbiter power system. After the Probe separates from the orbiter, the PCM releases its latent heat to make up the heat loss from the Probe exterior to space. Paraffin wax is a good PCM candidate.

Studying the sensitivity of monotop probes to compressed supersymmetric scenarios at the LHC

CERN Document Server

Fuks, Benjamin; Wilcock, Alexandra

2015-01-01

We investigate the sensitivity of the Large Hadron Collider to supersymmetric setups using monotop probes in which the signal is a single top quark produced in association with missing transverse energy. Our prospective study relies on Monte Carlo simulations of 300 invfb of proton- proton collisions at a centre-of-mass energy of 14 TeV and considers both leptonic and hadronic monotop decays. We present analysis strategies sensitive to regions of the supersymmetric parameter space which feature small superparticle mass splittings and illustrate their strengths in the context of a particular set of benchmark scenarios. Finally, we compare the regions of parameter space expected to be accessible with monotops probes during the next run of the LHC to the reach of more traditional search strategies employed by the ATLAS and CMS collaborations, where available.

Traversing probe system

Science.gov (United States)

Mashburn, Douglas N.; Stevens, Richard H.; Woodall, Harold C.

1977-01-01

This invention comprises a rotatable annular probe-positioner which carries at least one radially disposed sensing probe, such as a Pitot tube having a right-angled tip. The positioner can be coaxially and rotatably mounted within a compressor casing or the like and then actuated to orient the sensing probe as required to make measurements at selected stations in the annulus between the positioner and compressor casing. The positioner can be actuated to (a) selectively move the probe along its own axis, (b) adjust the yaw angle of the right-angled probe tip, and (c) revolve the probe about the axis common to the positioner and casing. A cam plate engages a cam-follower portion of the probe and normally rotates with the positioner. The positioner includes a first-motor-driven ring gear which effects slidable movement of the probe by rotating the positioner at a time when an external pneumatic cylinder is actuated to engage the cam plate and hold it stationary. When the pneumatic cylinder is not actuated, this ring gear can be driven to revolve the positioner and thus the probe to a desired circumferential location about the above-mentioned common axis. A second motor-driven ring gear included in the positioner can be driven to rotate the probe about its axis, thus adjusting the yaw angle of the probe tip. The positioner can be used in highly corrosive atmosphere, such as gaseous uranium hexafluoride.

Traversing probe system

International Nuclear Information System (INIS)

Mashburn, D.N.; Stevens, R.H.; Woodall, H.C.

1977-01-01

This invention comprises a rotatable annular probe-positioner which carries at least one radially disposed sensing probe, such as a Pitot tube having a right-angled tip. The positioner can be coaxially and rotatably mounted within a compressor casing or the like and then actuated to orient the sensing probe as required to make measurements at selected stations in the annulus between the positioner and compressor casing. The positioner can be actuated to (a) selectively move the probe along its own axis, (b) adjust the yaw angle of the right-angled probe tip, and (c) revolve the probe about the axis common to the positioner and casing. A cam plate engages a cam-follower portion of the probe and normally rotates with the positioner. The positioner includes a first-motor-driven ring gear which effects slidable movement of the probe by rotating the positioner at a time when an external pneumatic cylinder is actuated to engage the cam plate and hold it stationary. When the pneumatic cylinder is not actuated, this ring gear can be driven to revolve the positioner and thus the probe to a desired circumferential location about the above-mentioned common axis. A second motor-driven ring gear included in the positioner can be driven to rotate the probe about its axis, thus adjusting the yaw angle of the probe tip. The positioner can be used in highly corrosive atmosphere, such as gaseous uranium hexafluoride. 10 claims, 6 figures

Influence of probe geometry on the response of an electrostatic probe

DEFF Research Database (Denmark)

Johansson, Torben; Crichton, George C; McAllister, Iain Wilson

1999-01-01

The response of an electrostatic probe is examined with reference to the probe geometry. The study involves the evaluation of the probe lambda function, from which response-related characteristic parameters can be derived. These parameters enable the probe detection sensitivity Se and spatial...

The Oxford Probe: an open access five-hole probe for aerodynamic measurements

Science.gov (United States)

Hall, B. F.; Povey, T.

2017-03-01

The Oxford Probe is an open access five-hole probe designed for experimental aerodynamic measurements. The open access probe can be manufactured by the end user via additive manufacturing (metal or plastic). The probe geometry, drawings, calibration maps, and software are available under a creative commons license. The purpose is to widen access to aerodynamic measurement techniques in education and research environments. There are many situations in which the open access probe will allow results of comparable accuracy to a well-calibrated commercial probe. We discuss the applications and limitations of the probe, and compare the calibration maps for 16 probes manufactured in different materials and at different scales, but with the same geometrical design.

The Oxford Probe: an open access five-hole probe for aerodynamic measurements

International Nuclear Information System (INIS)

Hall, B F; Povey, T

2017-01-01

The Oxford Probe is an open access five-hole probe designed for experimental aerodynamic measurements. The open access probe can be manufactured by the end user via additive manufacturing (metal or plastic). The probe geometry, drawings, calibration maps, and software are available under a creative commons license. The purpose is to widen access to aerodynamic measurement techniques in education and research environments. There are many situations in which the open access probe will allow results of comparable accuracy to a well-calibrated commercial probe. We discuss the applications and limitations of the probe, and compare the calibration maps for 16 probes manufactured in different materials and at different scales, but with the same geometrical design. (paper)

Construction of the Hunveyor-Husar space probe model system for planetary science education and analog studies and simulations in universities and colleges of Hungary.

Science.gov (United States)

Bérczi, Sz.; Hegyi, S.; Hudoba, Gy.; Hargitai, H.; Kokiny, A.; Drommer, B.; Gucsik, A.; Pintér, A.; Kovács, Zs.

Several teachers and students had the possibility to visit International Space Camp in the vicinity of the MSFC NASA in Huntsville Alabama USA where they learned the success of simulators in space science education To apply these results in universities and colleges in Hungary we began a unified complex modelling in planetary geology robotics electronics and complex environmental analysis by constructing an experimental space probe model system First a university experimental lander HUNVEYOR Hungarian UNiversity surVEYOR then a rover named HUSAR Hungarian University Surface Analyser Rover has been built For Hunveyor the idea and example was the historical Surveyor program of NASA in the 1960-ies for the Husar the idea and example was the Pathfinder s rover Sojouner rover The first step was the construction of the lander a year later the rover followed The main goals are 1 to build the lander structure and basic electronics from cheap everyday PC compatible elements 2 to construct basic experiments and their instruments 3 to use the system as a space activity simulator 4 this simulator contains lander with on board computer for works on a test planetary surface and a terrestrial control computer 5 to harmonize the assemblage of the electronic system and instruments in various levels of autonomy from the power and communication circuits 6 to use the complex system in education for in situ understanding complex planetary environmental problems 7 to build various planetary environments for application of the

Heat transfer probe

Science.gov (United States)

Frank, Jeffrey I.; Rosengart, Axel J.; Kasza, Ken; Yu, Wenhua; Chien, Tai-Hsin; Franklin, Jeff

2006-10-10

Apparatuses, systems, methods, and computer code for, among other things, monitoring the health of samples such as the brain while providing local cooling or heating. A representative device is a heat transfer probe, which includes an inner channel, a tip, a concentric outer channel, a first temperature sensor, and a second temperature sensor. The inner channel is configured to transport working fluid from an inner inlet to an inner outlet. The tip is configured to receive at least a portion of the working fluid from the inner outlet. The concentric outer channel is configured to transport the working fluid from the inner outlet to an outer outlet. The first temperature sensor is coupled to the tip, and the second temperature sensor spaced apart from the first temperature sensor.

Probe-diverse ptychography

Energy Technology Data Exchange (ETDEWEB)

Peterson, I., E-mail: isaac.russellpeterson@rmit.edu.au [ARC Centre of Excellence for Coherent X-ray Science, the University of Melbourne, School of Physics, Victoria 3010 (Australia); Harder, R. [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States); Robinson, I.K. [Research Complex at Harwell, Didcot, Oxfordshire OX11 0DE (United Kingdom); London Centre for Nanotechnology, University College London, London WC1H 0AH (United Kingdom)

2016-12-15

We propose an extension of ptychography where the target sample is scanned separately through several probes with distinct amplitude and phase profiles and a diffraction image is recorded for each probe and each sample translation. The resulting probe-diverse dataset is used to iteratively retrieve high-resolution images of the sample and all probes simultaneously. The method is shown to yield significant improvement in the reconstructed sample image compared to the image obtained using the standard single-probe ptychographic phase-retrieval scheme.

The Huygens probe is prepared for transport from the Skid Strip, CCAS

Science.gov (United States)

1997-01-01

The Huygens probe, which will study the clouds, atmosphere and surface of Saturn's largest moon, Titan, as part of the Cassini mission to Saturn, is prepared for transport from the Skid Strip, Cape Canaveral Air Station (CCAS), after being off-loaded from a plane. The probe was designed and developed for the European Space Agency (ESA) by a European industrial consortium led by Aerospatiale as prime contractor. Over the past year, it was integrated and tested at the facilities of Daimler Benz Aerospace Dornier Satellitensysteme in Germany. The probe will be mated to the Cassini orbiter, which was designed and assembled at NASA's Jet Propulsion Laboratory in California. The Cassini launch is targeted for October 6 from CCAS aboard a Titan IVB/Centaur expendable launch vehicle. After arrival at Saturn in 2004, the probe will be released from the Cassini orbiter to slowly descend through the Titan atmosphere to the moon's surface.

Hard photons a probe of the heavy ion collision dynamics

International Nuclear Information System (INIS)

Schutz, Y.

1994-01-01

Heavy-ion collisions have proven to be a unique tool to study the nucleus in extreme states, with values of energy, spin and isospin far away from those encountered in the nucleus in its ground state. Heavy-ion collisions provide also the only mean to form and study in the laboratory nuclear matter under conditions of density and temperature which could otherwise only be found in stellar objects like neutron stars and super-novae. the goal of such studies is to establish the equation of state of nuclear matter and the method consist in searching the collective behaviour in which heavy-ion collisions differ from a superposition of many nucleon-nucleon collisions. Among the various probes of collective effects, like flow, multifragmentation, or subthreshold particles, we have selected hard photons because they provide, together with dileptons, the only unperturbed probe of a phase of the collision well localized in space and time. The origin of hard photons, defined as the photons building up the spectrum beyond the energy of the giant dipole resonance (E γ > 30∼MeV), is attributed predominantly to the bremsstrahlung radiation emitted incoherently in individual neutron-proton collisions. Their energy reflects the combination of the beam momentum and the momenta induced by the Fermi motion of the nucleons within the collision zone. Therefore, at intermediate energies, hard photons probe the dynamical phase space distribution of participant nucleons and they convey information on the densities reached in heavy-ion collisions, the size and life time of the dense photon source and the compressibility of nuclear matter. The techniques we have developed include intensity interferometry and exclusive measurements scanning with high resolution the whole range of impact parameters. The interpretation of our data is guided by dynamical phase space calculations of the BUU type

Space Weather Monitoring for ISS Geomagnetic Storm Studies

Science.gov (United States)

Minow, Joseph I.; Parker, Linda Neergaard

2013-01-01

The International Space Station (ISS) space environments community utilizes near real time space weather data to support a variety of ISS engineering and science activities. The team has operated the Floating Potential Measurement Unit (FPMU) suite of plasma instruments (two Langmuir probes, a floating potential probe, and a plasma impedance probe) on ISS since 2006 to obtain in-situ measurements of plasma density and temperature along the ISS orbit and variations in ISS frame potential due to electrostatic current collection from the plasma environment (spacecraft charging) and inductive (vxB) effects from the vehicle motion across the Earth s magnetic field. An ongoing effort is to use FPMU for measuring the ionospheric response to geomagnetic storms at ISS altitudes and investigate auroral charging of the vehicle as it passes through regions of precipitating auroral electrons. This work is challenged by restrictions on FPMU operations that limit observation time to less than about a third of a year. As a result, FPMU campaigns ranging in length from a few days to a few weeks are typically scheduled weeks in advance for ISS engineering and payload science activities. In order to capture geomagnetic storm data under these terms, we monitor near real time space weather data from NASA, NOAA, and ESA sources to determine solar wind disturbance arrival times at Earth likely to be geoeffective (including coronal mass ejections and high speed streams associated with coronal holes) and activate the FPMU ahead of the storm onset. Using this technique we have successfully captured FPMU data during a number of geomagnetic storm periods including periods with ISS auroral charging. This presentation will describe the strategies and challenges in capturing FPMU data during geomagnetic storms, the near real time space weather resources utilized for monitoring the space weather environment, and provide examples of auroral charging data obtained during storm operations.

Gravitational waves as a new probe of Bose–Einstein condensate Dark Matter

Directory of Open Access Journals (Sweden)

P.S. Bhupal Dev

2017-10-01

Full Text Available There exists a class of ultralight Dark Matter (DM models which could give rise to a Bose–Einstein condensate (BEC in the early universe and behave as a single coherent wave instead of individual particles in galaxies. We show that a generic BEC-DM halo intervening along the line of sight of a gravitational wave (GW signal could induce an observable change in the speed of GWs, with the effective refractive index depending only on the mass and self-interaction of the constituent DM particles and the GW frequency. Hence, we propose to use the deviation in the speed of GWs as a new probe of the BEC-DM parameter space. With a multi-messenger approach to GW astronomy and/or with extended sensitivity to lower GW frequencies, the entire BEC-DM parameter space can be effectively probed by our new method in the near future.

High-resolution disruption halo current measurements using Langmuir probes in Alcator C-Mod

Science.gov (United States)

Tinguely, R. A.; Granetz, R. S.; Berg, A.; Kuang, A. Q.; Brunner, D.; LaBombard, B.

2018-01-01

Halo currents generated during disruptions on Alcator C-Mod have been measured with Langmuir ‘rail’ probes. These rail probes are embedded in a lower outboard divertor module in a closely-spaced vertical (poloidal) array. The dense array provides detailed resolution of the spatial dependence (~1 cm spacing) of the halo current distribution in the plasma scrape-off region with high time resolution (400 kHz digitization rate). As the plasma limits on the outboard divertor plate, the contact point is clearly discernible in the halo current data (as an inversion of current) and moves vertically down the divertor plate on many disruptions. These data are consistent with filament reconstructions of the plasma boundary, from which the edge safety factor of the disrupting plasma can be calculated. Additionally, the halo current ‘footprint’ on the divertor plate is obtained and related to the halo flux width. The voltage driving halo current and the effective resistance of the plasma region through which the halo current flows to reach the probes are also investigated. Estimations of the sheath resistance and halo region resistivity and temperature are given. This information could prove useful for modeling halo current dynamics.

Studying the sensitivity of monotop probes to compressed supersymmetric scenarios at the LHC

International Nuclear Information System (INIS)

Fuks, Benjamin; Richardson, Peter; Wilcock, Alexandra

2015-01-01

We investigate the sensitivity of the Large Hadron Collider to supersymmetric setups using monotop probes in which the signal is a single top quark produced in association with missing transverse energy. Our prospective study relies on Monte Carlo simulations of 300 fb -1 of proton-proton collisions at a centre-of-mass energy of 14 TeV and considers both leptonic and hadronic monotop decays. We present analysis strategies sensitive to regions of the supersymmetric parameter space which feature small superparticle mass splittings and illustrate their strengths in the context of a particular set of benchmark scenarios. Finally, we compare the regions of parameter space expected to be accessible with monotops probes during the next run of the LHC to the reach of more traditional search strategies employed by the ATLAS and CMS collaborations, where available. (orig.)

Tools to probe the universe; Des outils pour sonder l'univers

Energy Technology Data Exchange (ETDEWEB)

Lagage, P.O.; Augueres, J.L.; Amiaux, J.; Cara, Ch.; Fontignie, J.; Rio, Y.; Fermon, C.; Pannetier-Lecoeur, M.; De Vismes, A.; Cordier, B.; Fesquet, M.; Ferrando, Ph.; Authier, M.; Pantin, E.; Glicenstein, J.F.; Boulade, O.; Refregier, A.; Stolarczyk, Th.; Agnese, P.; Rodriguez, L.; Agnese, P.; Pigot, C.; Duband, L.; Limousin, O.; Delagnes, E.; Turck-Chieze, S.; Carton, P.H.; Starck, J.L.; Bournaud, F.; Teyssier, R.; Audit, E.; Brun, A.S.; Leca, P.; Menache, Ch.; Pomarede, D.; Thooris, B.; Meis, C.

2009-07-01

This special issue of Clefs CEA journal is entirely devoted to astrophysics and to the exploration and probing of the Universe. The second part of this dossier, described here, makes a status of the tools used to probe the universe: telescopes, imaging spectrometers, data processing and simulation. Content: A - Telescopes of the future: 1. Seeing further out: JWST: looking back on a past 13 billion years old, Space specifics: the learning curve to know-how, Fabricating a corona-graph mask, SVOM, a satellite to detect the explosions of the first stars to be formed in the Universe; 2. Seeing more precisely: SIMBOL-X, pioneering formation flying, ELT/METIS, a 42-meter giant, One hundred telescopes for the CTA arrays; 3. Seeing wider: Euclid, mapping the extragalactic sky, ANTARES: the neutrino, another cosmic messenger; B - The new generation of imaging spectrometers: Observing the Universe in the submillimeter spectral region, The X-ray Universe, Space cryo-coolers, Out in the extreme, tumultuous Universe, Probing the Sun with GOLF-NG, Focus: From light to imagery; C - Data analysis in astrophysics; D - Numerical simulation in astrophysics: Information technology and theoretical predictions in astrophysics, Supercomputers for a better understanding of the Universe, The visualization of astrophysical simulations, Godunov, a numerical platform for education and research

MIMO OTA Testing in Small Multi-Probe Anechoic Chamber Setups

DEFF Research Database (Denmark)

Llorente, Ines Carton; Fan, Wei; Pedersen, Gert F.

2016-01-01

OTA testing of MIMO capable terminals is often performed in large anechoic chambers, where planar waves impinging the test area are assumed. Furthermore, reflections from the chamber, and probe coupling are often considered negligible due to the large dimensions of the chamber. This paper...... investigates the feasibility of reducing the physical dimension of 2D multi-probe anechoic chamber setups for MIMO OTA testing, with the purpose of reducing the cost and space of the setup. In the paper, a channel emulation algorithm and chamber compensation technique are proposed for MIMO OTA testing in small...... anechoic chambers. The performance deterioration in a small anechoic chamber, i.e., with a ring radius of 0.5 m, is demonstrated via simulations....

Gravity Probe-B (GP-B) Mission and Tracking, Telemetry and Control Subsystem Overview

Science.gov (United States)

Kennedy, Paul; Bell, Joseph L. (Technical Monitor)

2001-01-01

The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) in Huntsville, Alabama will launch the Gravity Probe B (GP-B) space experiment in the Fall of 2002. The GP-B spacecraft was developed to prove Einstein's theory of General Relativity. This paper will provide an overview of the GPB mission and will discuss the design, and test of the spacecraft Tracking, Telemetry and Control (TT&C) subsystem which incorporates NASA's latest generation standard transponder for use with the NASA Tracking and Data Relay Satellite System (TDRSS).

High spatial resolution Kelvin probe force microscopy with coaxial probes

International Nuclear Information System (INIS)

Brown, Keith A; Westervelt, Robert M; Satzinger, Kevin J

2012-01-01

Kelvin probe force microscopy (KPFM) is a widely used technique to measure the local contact potential difference (CPD) between an AFM probe and the sample surface via the electrostatic force. The spatial resolution of KPFM is intrinsically limited by the long range of the electrostatic interaction, which includes contributions from the macroscopic cantilever and the conical tip. Here, we present coaxial AFM probes in which the cantilever and cone are shielded by a conducting shell, confining the tip–sample electrostatic interaction to a small region near the end of the tip. We have developed a technique to measure the true CPD despite the presence of the shell electrode. We find that the behavior of these probes agrees with an electrostatic model of the force, and we observe a factor of five improvement in spatial resolution relative to unshielded probes. Our discussion centers on KPFM, but the field confinement offered by these probes may improve any variant of electrostatic force microscopy. (paper)

A computational geometry framework for the optimisation of atom probe reconstructions

Energy Technology Data Exchange (ETDEWEB)

Felfer, Peter [Australian Centre for Microscopy and Microanalysis, The University of Sydney, NSW 2006 (Australia); Institute for General Materials Properties, Department of Materials Science, Friedrich-Alexander University Erlangen-Nürnberg, 91058 Erlangen (Germany); Cairney, Julie [Australian Centre for Microscopy and Microanalysis, The University of Sydney, NSW 2006 (Australia)

2016-10-15

In this paper, we present pathways for improving the reconstruction of atom probe data on a coarse (>10 nm) scale, based on computational geometry. We introduce a way to iteratively improve an atom probe reconstruction by adjusting it, so that certain known shape criteria are fulfilled. This is achieved by creating an implicit approximation of the reconstruction through a barycentric coordinate transform. We demonstrate the application of these techniques to the compensation of trajectory aberrations and the iterative improvement of the reconstruction of a dataset containing a grain boundary. We also present a method for obtaining a hull of the dataset in both detector and reconstruction space. This maximises data utilisation, and can be used to compensate for ion trajectory aberrations caused by residual fields in the ion flight path through a ‘master curve’ and correct for overall shape deviations in the data. - Highlights: • An atom probe reconstruction can be iteratively improved by using shape constraints. • An atom probe reconstruction can be inverted using barycentric coordinate transforms. • Hulls for atom probe datasets can be obtained from 2D detector outlines that are co-reconstructed with the data. • Ion trajectory compressions caused by instrument-specific residual fields in the drift tube can be corrected.

Artist's Concept of Gravity Probe-B

Science.gov (United States)

2002-01-01

Gravity Probe-B (GP-B) is the relativity experiment being developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies -- technologies that are already enlivening other branches of science and engineering. Scheduled for launch in 2003 and managed for NASA by Marshall Space Flight Center, development of GP-B is the responsibility of Stanford University, with major subcontractor Lockheed Martin Corporation.

Tests of Hadronic Probes of GT Strength

CERN Multimedia

2002-01-01

There are many important problems where one wishes to know the distribution of Gamow-Teller (GT) strength in circumstances where it cannot be measured directly (for example, because of energy-release limitations). Then one must rely on hadronic probes to infer the GT strength. It is therefore essential to test these probes as extensively as possible. The isospin-analog transitions in $^{37}$Ca $\\beta^{+}$ -decay and $^{37}$Cl$(p, n)$ provide an excellent ground for such a test. Recent $^{37}$Cl$ (p, n) $ studies, while qualitatively in agreement with our previous ISOLDE work on $^{37}$Ca $\\beta^{+} $ -decay, show quantitative discrepancies that appear to grow as the excitation energy in the residual nuclei increases. Because of the bulk of the GT strengh appears at these high excitation energies, it is important to extend the $\\beta$-decay data to even higher excitation energies where, because of rapidly diminishing phase-space, strong GT transitions correspond to very weak $\\beta$ -branches. We propose to do...

Comparison of Simulated PEC Probe Performance for Detecting Wall Thickness Reduction

International Nuclear Information System (INIS)

Shin, Young Kil; Choi, Dong Myung; Jung, Hee Sung

2009-01-01

In this paper, four different types of pulsed eddy current(PEC) probe are designed and their performance of detecting wall thickness reduction is compared. By using the backward difference method in time and the finite element method in space, PEC signals from various thickness and materials are numerically calculated and three features of the signal are selected. Since PEC signals and features are obtained by various types and sizes of probe, the comparison is made through the normalized features which reflect the sensitivity of the feature to thickness reduction. The normalized features indicate that the shielded reflection probe provides the best sensitivity to wall thickness reduction for all three signal features. Results show that the best sensitivity to thickness reduction can be achieved by the peak value, but also suggest that the time to peak can be a good candidate because of its linear relationship with the thickness variation.

Advanced development of particle-beam-probe diagnostic systems. Technical progress report, 1 July 1980-30 April 1981

International Nuclear Information System (INIS)

Hickok, R.L.; Jennings, W.C.; Woo, J.T.; Connor, K.A.

1981-05-01

The heavy ion beam probe system on the RENTOR tokamak has been reinstalled with considerably improved performance. The heavy neutral beam probe system on the ALEX baseball facility has demonstrated the capability of measuring space potential in minimum-B geometry. A large amount of data were obtained from the highly successful TMX beam probe system and are presently being analyzed. Technological improvements were made on both the RENTOR and ALEX diagnostic systems, new ion sources and extraction configurations were investigated, and the superiority of off-line processing techniques for beam probe data has been demonstrated. The development of high energy probing beams for application to major confinement experiments has been initiated and cross-over sweep systems to improve spatial resolution, differential pumping, and reduce energy requirements have been designed

Resolution enhancement of scanning four-point-probe measurements on two-dimensional systems

DEFF Research Database (Denmark)

Hansen, Torben Mikael; Stokbro, Kurt; Hansen, Ole

2003-01-01

A method to improve the resolution of four-point-probe measurements of two-dimensional (2D) and quasi-2D systems is presented. By mapping the conductance on a dense grid around a target area and postprocessing the data, the resolution can be improved by a factor of approximately 50 to better than 1....../15 of the four-point-probe electrode spacing. The real conductance sheet is simulated by a grid of discrete resistances, which is optimized by means of a standard optimization algorithm, until the simulated voltage-to-current ratios converges with the measurement. The method has been tested against simulated...

Space activity impact on science and technology. Proceedings of the twenty-fourth international astronautical congress, Baku, USSR, October 7--13, 1973

Energy Technology Data Exchange (ETDEWEB)

Napolitano, L G; Contensou, P; Hilton, W F [eds.

1976-01-01

Topics covered include: Soviet automatic vehicles for lunar exploration and their influence on the progress of automatics and control theory; the problems of space technology and their influence on science and technics; industrial use of aerospace technology; development of liquid-propellant rocket engine engineering and its influence on science and technology in the USSR; space medicine and public health; impact of space activity on technology in a country the size of France; astronautics as a stimulus for celestial mechanics; space activity impact on the science and technology of rotating bodies; skylab systems flight performance, an interim report; the design and utilization of a spacelab for sortie missions; the spacelab program; man and the environment, remote sensing from space; EOLE application program for meteorological experiments, complementary experiences; machine processing methods for earth observational data; recent advances in geologic applications of remote sensing from space; infrared scanning for meteorological purposes; spatial antartic glaciology; reflection spectra usage in recognition of plant covers; experimental investigation of aeronautical and maritime communications and surveillance using satellites; the ESRO MAROTS program; the problem of habitability in spaceships; atmosphere revitalization for manned spacecraft; prospects of international cooperation in medical sciences; developing a technology base in planetary entry aerothermodynamics; scientific results of the automatic ionospheric laboratory Yantar 4 flight; nonlinear unsteady motions in solid propellant rockets with application to large motors; investigation of the physical and mechanical properties of the lunar sample brought by Luna 20 and along the route of motion of Lunokhod 2; orbiting astronomical observatory Copernicus; the delta launch vehicle model 2914 series; space tug mission and program planning; space and education; and safety in youth rocket experiments. (GHT)

Using thermal phase curves to probe the climate of potentially habitable planets

Science.gov (United States)

Kataria, Tiffany

2018-01-01

Thermal phase-curve observations probe the variation in emitted flux of a planet with phase, or longitude. When conducted spectroscopically, they allow us to probe the two-dimensional temperature structure in both longitude and altitude, which directly relate to the planet’s circulation and chemistry. In the case of small, potentially habitable exoplanets, spectroscopic phase-curve observations can provide us with direct evidence that the planet is capable of sustaining liquid water from measurements of its brightness temperature, and allow us to distinguish between a ‘airless’ body and one that has an appreciable atmosphere. In this talk I will summarize efforts to characterize exoplanets smaller than Neptune with phase-curve observations and emission spectroscopy using the Spitzer and Hubble Space Telescopes. I will then discuss how these ‘lessons learned’ can be applied to future efforts to characterize potentially habitable planets with phase-curve observations using JWST and future facilities such as the Origins Space Telescope (OST).

12th Reinventing Space Conference

CERN Document Server

2017-01-01

The 2014 Reinventing Space conference presented a number of questions in the context of a constantly innovating space industry, from addressing the future of global cooperation, investigating the impact of cuts in US government spending on the private space sector, and probing the overall future of the commercial launch sector. Space tourism and new technology promise the revival of interest in space development (the Apollo Era was the first period of intense space activity and growth). The need to create dramatically lower cost, responsive and reliable launch systems and spacecraft has never been more vital. Advances in technology are allowing smaller and cheaper satellites to be orbited - from cubesats to nanosatellites to femtosatellites. Thanks to more efficient new launch possibilities, low cost access to space is becoming ever more achievable. Commercial companies and countries are targeting the industry with new funding. Organised by the British Interplanetary Society, the presentations at this confere...

Characterizing the performance of an affordable, multichannel conductivity probe for density measurements in stratified flows

Science.gov (United States)

Subramanian, Balaji; Carminati, Marco; Luzzatto-Fegiz, Paolo

2017-11-01

In stratified flows, conductivity (combined with temperature) is often used to measure density. The conductivity probes typically used can resolve very fine spatial scales, but on the downside they are fragile, expensive, sensitive to environmental noise and have only single channel capability. Recently a low-cost, robust, arduino-based probe called Conduino was developed, which can be valuable in a wide range of applications where resolving extremely small spatial scales is not needed. This probe uses micro-USB connectors as actual conductivity sensors with a custom designed electronic board for simultaneous acquisition from multiple probes, with conductivity resolution comparable to commercially available PME conductivity probe. A detailed assessment of performance of this Conduino probe is described here. To establish time response and sensitivity as a function of electrode geometry, we build a variety of shapes for different kinds of applications, with tip spacing ranging from 0.5-2.5 mm, and with electrode length ranging from 2.3-6 mm. We set up a two-layer density profile and traverse it rapidly, yielding a time response comparable to PME. The Conduino's multi-channel capability is used to operate probe arrays, which helps to construct density fields in stratified flows.

Characterization of wake region by using and emissive probe

International Nuclear Information System (INIS)

Jeong, Yong Ho

1993-02-01

An emissive probe was designed and manufactured to measure the floating and the space potentials of plasma in the wake region. The floating potential method' among various schemes was used for the measurement and analysis. To generate the wake, a plane artificial satellite with circular shape was introduced in a simply discharged argon plasma without the magnetic field. Potentials along the radial direction in and out of the wake regions of artificial satellite were measured, and plasma parameters were compared in the both regions. In the wake region, the floating potential was higher than that out of the wake, the space potential was approximately equal to that out of the wake, when the positive voltage was applied to artificial satellite, the floating and the space potentials were lower than that out of the wake and when the negative voltage was applied to artificial satellite, the floating potential was higher, the space potential was lower than that out of the wake

DNA probes

International Nuclear Information System (INIS)

Castelino, J.

1992-01-01

The creation of DNA probes for detection of specific nucleotide segments differs from ligand detection in that it is a chemical rather than an immunological reaction. Complementary DNA or RNA is used in place of the antibody and is labelled with 32 P. So far, DNA probes have been successfully employed in the diagnosis of inherited disorders, infectious diseases, and for identification of human oncogenes. The latest approach to the diagnosis of communicable and parasitic infections is based on the use of deoxyribonucleic acid (DNA) probes. The genetic information of all cells is encoded by DNA and DNA probe approach to identification of pathogens is unique because the focus of the method is the nucleic acid content of the organism rather than the products that the nucleic acid encodes. Since every properly classified species has some unique nucleotide sequences that distinguish it from every other species, each organism's genetic composition is in essence a finger print that can be used for its identification. In addition to this specificity, DNA probes offer other advantages in that pathogens may be identified directly in clinical specimens

Counting probe

International Nuclear Information System (INIS)

Matsumoto, Haruya; Kaya, Nobuyuki; Yuasa, Kazuhiro; Hayashi, Tomoaki

1976-01-01

Electron counting method has been devised and experimented for the purpose of measuring electron temperature and density, the most fundamental quantities to represent plasma conditions. Electron counting is a method to count the electrons in plasma directly by equipping a probe with the secondary electron multiplier. It has three advantages of adjustable sensitivity, high sensitivity of the secondary electron multiplier, and directional property. Sensitivity adjustment is performed by changing the size of collecting hole (pin hole) on the incident front of the multiplier. The probe is usable as a direct reading thermometer of electron temperature because it requires to collect very small amount of electrons, thus it doesn't disturb the surrounding plasma, and the narrow sweep width of the probe voltage is enough. Therefore it can measure anisotropy more sensitively than a Langmuir probe, and it can be used for very low density plasma. Though many problems remain on anisotropy, computer simulation has been carried out. Also it is planned to provide a Helmholtz coil in the vacuum chamber to eliminate the effect of earth magnetic field. In practical experiments, the measurement with a Langmuir probe and an emission probe mounted to the movable structure, the comparison with the results obtained in reverse magnetic field by using a Helmholtz coil, and the measurement of ionic sound wave are scheduled. (Wakatsuki, Y.)

The 100th anniversary of the four-point probe technique: the role of probe geometries in isotropic and anisotropic systems

International Nuclear Information System (INIS)

Miccoli, I; Edler, F; Pfnür, H; Tegenkamp, C

2015-01-01

The electrical conductivity of solid-state matter is a fundamental physical property and can be precisely derived from the resistance measured via the four-point probe technique excluding contributions from parasitic contact resistances. Over time, this method has become an interdisciplinary characterization tool in materials science, semiconductor industries, geology, physics, etc, and is employed for both fundamental and application-driven research. However, the correct derivation of the conductivity is a demanding task which faces several difficulties, e.g. the homogeneity of the sample or the isotropy of the phases. In addition, these sample-specific characteristics are intimately related to technical constraints such as the probe geometry and size of the sample. In particular, the latter is of importance for nanostructures which can now be probed technically on very small length scales. On the occasion of the 100th anniversary of the four-point probe technique, introduced by Frank Wenner, in this review we revisit and discuss various correction factors which are mandatory for an accurate derivation of the resistivity from the measured resistance. Among others, sample thickness, dimensionality, anisotropy, and the relative size and geometry of the sample with respect to the contact assembly are considered. We are also able to derive the correction factors for 2D anisotropic systems on circular finite areas with variable probe spacings. All these aspects are illustrated by state-of-the-art experiments carried out using a four-tip STM/SEM system. We are aware that this review article can only cover some of the most important topics. Regarding further aspects, e.g. technical realizations, the influence of inhomogeneities or different transport regimes, etc, we refer to other review articles in this field. (topical review)

NASA and international studies of the Solar Probe Mission

Science.gov (United States)

Randolph, James E.

1992-01-01

A review is presented summarizing the history and current status of the studies of the Solar Probe Mission by NASA and other space agencies. The technology and scientific challenges of the mission are addressed in these studies and can be met with current instrument and technology capabilities. The specific set of experiments recommended by a scientific advisory group to the NASA study for integration into the design concept is discussed.

Gravity Probe B Gyroscope Rotor

Science.gov (United States)

2003-01-01

The Gravity Probe B (GP-B) is the relativity experiment developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. This photograph is a close up of a niobium-coated gyroscope motor and its housing halves. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies that are already enlivening other branches of science and engineering. Launched April 20, 2004 , the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Don Harley.)

Pump laser-induced space-charge effects in HHG-driven time- and angle-resolved photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Oloff, L.-P., E-mail: oloff@physik.uni-kiel.de; Hanff, K.; Stange, A.; Rohde, G.; Diekmann, F.; Bauer, M.; Rossnagel, K., E-mail: rossnagel@physik.uni-kiel.de [Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, D-24098 Kiel (Germany)

2016-06-14

With the advent of ultrashort-pulsed extreme ultraviolet sources, such as free-electron lasers or high-harmonic-generation (HHG) sources, a new research field for photoelectron spectroscopy has opened up in terms of femtosecond time-resolved pump-probe experiments. The impact of the high peak brilliance of these novel sources on photoemission spectra, so-called vacuum space-charge effects caused by the Coulomb interaction among the photoemitted probe electrons, has been studied extensively. However, possible distortions of the energy and momentum distributions of the probe photoelectrons caused by the low photon energy pump pulse due to the nonlinear emission of electrons have not been studied in detail yet. Here, we systematically investigate these pump laser-induced space-charge effects in a HHG-based experiment for the test case of highly oriented pyrolytic graphite. Specifically, we determine how the key parameters of the pump pulse—the excitation density, wavelength, spot size, and emitted electron energy distribution—affect the measured time-dependent energy and momentum distributions of the probe photoelectrons. The results are well reproduced by a simple mean-field model, which could open a path for the correction of pump laser-induced space-charge effects and thus toward probing ultrafast electron dynamics in strongly excited materials.

Mobile probes

DEFF Research Database (Denmark)

Ørngreen, Rikke; Jørgensen, Anna Neustrup; Noesgaard, Signe Schack

2016-01-01

A project investigating the effectiveness of a collection of online resources for teachers' professional development used mobile probes as a data collection method. Teachers received questions and tasks on their mobile in a dialogic manner while in their everyday context as opposed...... to in an interview. This method provided valuable insight into the contextual use, i.e. how did the online resource transfer to the work practice. However, the research team also found that mobile probes may provide the scaffolding necessary for individual and peer learning at a very local (intra-school) community...... level. This paper is an initial investigation of how the mobile probes process proved to engage teachers in their efforts to improve teaching. It also highlights some of the barriers emerging when applying mobile probes as a scaffold for learning....

The determination of maturity levels in source rocks of the La Luna Formation, Maracaibo Basin, Venezuela, based on convention geochemical parameters and asphaltenes; Determinacao do grau de maturacao em rochas geradoras de petroleo, formacao La Luna, Bacia de Maracaibo, Venezuela: parametros geoquimicos convencionais e asfaltenos

Energy Technology Data Exchange (ETDEWEB)

Castro, L.P. de [Pontificia Universidade Catolica (PUC-RS), Porto Alegre, RS (Brazil). Centro de Excelencia em Pesquisas sobre o Armazenamento de Carbono; Franco, N. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Dept. de Geologia; Lopez, L.; Lo Monaco, S.; Escobar, G. [Universidad Central de Venezuela (UCV), Caracas (Venezuela); Kalkreuth, W. [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Centro de Excelencia em Analises de Carvao e Rochas Geradoras de Petroleo

2008-07-01

The La Luna Formation, main source rock of the Maracaibo Basin was studied by conventional geochemical parameters, used to determine the maturity, and they were compared with the physic-chemical and molecular properties of the asphaltenes present in the bitumen of the rocks. Three wells were studied (A, B and C) with a total of 13 samples. Based on Rock-Eval results the organic matter in well A (455 deg C Tmax) shows a relatively high level of maturation (top of the oil window), whereas the organic matter in well B (435 - 436 deg C Tmax) is in the beginning of the oil window. Tmax values in well C (438 - 446 deg C) and well C suggest an intermediate maturity level. The biomarkers identified in well B and C show ratios indicating an equilibrium state in the maturity level. A good correlation was found comparing the conventional analytical data with the determination of maturity level obtained from the asphaltenes precipitated from the bitumen of the samples. With increased maturity levels the H1 NMR analysis showed enrichment in aromatic molecules in relation to aliphatic, due to the bitumen aromatization process. Similarly, the asphaltenes molecular weight has higher values in samples characterized by elevated maturity levels. This confirms earlier studies that showed that asphaltenes may be utilized as maturity parameter of organic matter. (author)

Estimating Highway Volumes Using Vehicle Probe Data - Proof of Concept: Preprint

Energy Technology Data Exchange (ETDEWEB)

Hou, Yi [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Young, Stanley E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sadabadi, Kaveh [University of Maryland; SekuBa, PrzemysBaw [University of Maryland; Markow, Denise [I95 Corridor Coalition

2018-03-13

This paper examines the feasibility of using sampled commercial probe data in combination with validated continuous counter data to accurately estimate vehicle volume across the entire roadway network, for any hour during the year. Currently either real time or archived volume data for roadways at specific times are extremely sparse. Most volume data are average annual daily traffic (AADT) measures derived from the Highway Performance Monitoring System (HPMS). Although methods to factor the AADT to hourly averages for typical day of week exist, actual volume data is limited to a sparse collection of locations in which volumes are continuously recorded. This paper explores the use of commercial probe data to generate accurate volume measures that span the highway network providing ubiquitous coverage in space, and specific point-in-time measures for a specific date and time. The paper examines the need for the data, fundamental accuracy limitations based on a basic statistical model that take into account the sampling nature of probe data, and early results from a proof of concept exercise revealing the potential of probe type data calibrated with public continuous count data to meet end user expectations in terms of accuracy of volume estimates.

Results of the space shuttle vehicle ascent air data system probe calibration test using a 0.07-scale external tank forebody model (68T) in the AEDC 16-foot transonic wind tunnel (IA-310), volume 2

Science.gov (United States)

Collette, J. G. R.

1991-01-01

A recalibration of the Space Shuttle Vehicle Ascent Air Data System probe was conducted in the Arnold Engineering and Development Center (AEDC) transonic wind tunnel. The purpose was to improve on the accuracy of the previous calibration in order to reduce the existing uncertainties in the system. A probe tip attached to a 0.07-scale External Tank Forebody model was tested at angles of attack of -8 to +4 degrees and sideslip angles of -4 to +4 degrees. High precision instrumentation was used to acquire pressure data at discrete Mach numbers ranging from 0.6 to 1.55. Pressure coefficient uncertainties were estimated at less than 0.0020. Additional information is given in tabular form.

Results of the space shuttle vehicle ascent air data system probe calibration test using a 0.07-scale external tank forebody model (68T) in the AEDC 16-foot transonic wind tunnel (IA-310), volume 1

Science.gov (United States)

Collette, J. G. R.

1991-01-01

A recalibration of the Space Shuttle Vehicle Ascent Air Data System probe was conducted in the Arnold Engineering Development Center (AEDC) transonic wind tunnel. The purpose was to improve on the accuracy of the previous calibration in order to reduce the existing uncertainties in the system. A probe tip attached to a 0.07-scale External Tank Forebody model was tested at angles of attack of -8 to +4 degrees and sideslip angles of -4 to +4 degrees. High precision instrumentation was used to acquire pressure data at discrete Mach numbers ranging from 0.6 to 1.55. Pressure coefficient uncertainties were estimated at less than 0.0020. Data is given in graphical and tabular form.

Accuracy of probing attachment levels using a new computerized cemento-enamel junction probe.

Science.gov (United States)

Deepa, R; Prakash, Shobha

2012-01-01

The assessment of clinical attachment level (CAL) represents the gold standard for diagnosing and monitoring periodontal disease. The aim of the present study was to evaluate the performance of the newly introduced cemento-enamel junction (CEJ) probe in detecting CAL, using CEJ as a fixed reference point, and to compare the CEJ probe with the Florida stent probe (FSP) as well as with a standard manual probe, University of North Carolina-15 (UNC-15). Three examiners recorded the probing attachment level in 384 sites in case group (chronic periodontitis), and in 176 sites, in control group (healthy periodontal status), using the three probes. Subjects included both the sexes and ranged from 35 to 45 years. The experimental design was structured to balance the intra- and inter-examiner consistency at the same site during the two visits. CEJ probe showed higher intra-and inter-examiner consistency over both FSP and UNC-15 in both the case and control groups. Frequency distribution of differences of various magnitudes of repeated measurements ≤1 mm was in the higher range of 86.8% to 87.5% for CEJ probe. The FSP was more reproducible than UNC-15 in detecting relative attachment level (RAL). CEJ automated probe was found to have greatest potential for accuracy and consistency in detecting CAL than FSP and UNC-15. The automated probes appeared to be more reproducible than manual probes.

DNA probes

Energy Technology Data Exchange (ETDEWEB)

Castelino, J

1993-12-31

The creation of DNA probes for detection of specific nucleotide segments differs from ligand detection in that it is a chemical rather than an immunological reaction. Complementary DNA or RNA is used in place of the antibody and is labelled with {sup 32}P. So far, DNA probes have been successfully employed in the diagnosis of inherited disorders, infectious diseases, and for identification of human oncogenes. The latest approach to the diagnosis of communicable and parasitic infections is based on the use of deoxyribonucleic acid (DNA) probes. The genetic information of all cells is encoded by DNA and DNA probe approach to identification of pathogens is unique because the focus of the method is the nucleic acid content of the organism rather than the products that the nucleic acid encodes. Since every properly classified species has some unique nucleotide sequences that distinguish it from every other species, each organism`s genetic composition is in essence a finger print that can be used for its identification. In addition to this specificity, DNA probes offer other advantages in that pathogens may be identified directly in clinical specimens 10 figs, 2 tabs

Strongly emissive plasma-facing material under space-charge limited regime: Application to emissive probes

Czech Academy of Sciences Publication Activity Database

Cavalier, Jordan; Lemoine, N.; Bousselin, G.; Plihon, N.; Ledig, J.

2017-01-01

Roč. 24, č. 1 (2017), č. článku 013506. ISSN 1070-664X Institutional support: RVO:61389021 Keywords : plasma * tokamak * emissive probes Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.115, year: 2016 http://dx.doi.org/10.1063/1.4973557

Ion beam probe diagnostic system. Technical progress report, 1 January 1979-30 June 1980. RPDL report No. 80-17

International Nuclear Information System (INIS)

Hickok, R.L.; Jennings, W.C.; Woo, J.T.; Connor, K.A.

1980-07-01

Tokomak plasmas suitable for diagnostic development were produced during this period in RENTOR following technological improvements in the vacuum chamber and discharge cleaning systems. Secondary ion signals were obtained from the heavy ion beam probe on RENTOR leading to initial estimates of the plasma space potential, which appears to vary by several hundred volts during the plasma pulse. The principle of measuring space potential in a minimum-B geometry was established using an ion gun mounted at the center of the ALEX baseball coil. The neutral beam probe was installed for measuring the space potential using actual secondary ion signals from a hollow cathode arc in ALEX and preliminary tests have begun. The ion beam test stand was significantly altered to allow more flexibility in testing energy analyzers, ion guns, and ion focusing concepts

Women in Space — Following Valentina

CERN Document Server

Shayler, David J

2005-01-01

Space exploration has developed from early, unmanned space probes through the pioneering years of the ‘Manned’ Mercury, Gemini, and Apollo missions, to missions that now include women in the crew as a matter of course. Dave Shayler tells the story of the first woman balloonist in 1784 to their breakthrough as astronauts and cosmonauts in a range of professional roles. He covers the contribution women have made to space exploration and draws on interviews with Shuttle and Mir crew members who were women. These interviews detail the achievements of the first female Shuttle commander and the first female resident crew member of the International Space Station. These and many other events are presented in a detailed and highly readable account that recalls the difficult path to space exploration by women.

Estimation of a melting probe's penetration velocity range to reach icy moons' subsurface ocean

Science.gov (United States)

Erokhina, Olga; Chumachenko, Eugene

2014-05-01

In modern space science one of the actual branches is icy satellites explorations. The main interest is concentrated around Jovian's moons Europa and Ganymede, Saturn's moons Titan and Enceladus that are covered by thick icy layer according to "Voyager1", "Voyager2", "Galileo" and "Cassini" missions. There is a big possibility that under icy shell could be a deep ocean. Also conditions on these satellites allow speculating about possible habitability, and considering these moons from an astrobiological point of view. One of the possible tasks of planned missions is a subsurface study. For this goal it is necessary to design special equipment that could be suitable for planetary application. One of the possible means is to use a melting probe which operates by melting and moves by gravitational force. Such a probe should be relatively small, should not weight too much and should require not too much energy. In terrestrial case such kind of probe has been successfully used for glaciers study. And it is possible to extrapolate the usage of such probe to extraterrestrial application. One of the tasks is to estimate melting probe's penetration velocity. Although there are other unsolved problems such as analyzing how the probe will move in low gravity and low atmospheric pressure; knowing whether hole will be closed or not when probe penetrate thick enough; and considering what order could be a penetration velocity. This study explores two techniques of melting probe's movement. One of them based on elasto-plastic theory and so-called "solid water" theory, and other one takes phase changing into account. These two techniques allow estimating melting probe's velocity range and study whole process. Based on these technique several cases of melting probe movement were considered, melting probe's velocity range estimated, influence of different factors studied and discussed and an easy way to optimize parameters of the melting probe proposed.

Ex vivo imaging of early dental caries within the interproximal space

Science.gov (United States)

Choo-Smith, Lin-P'ing; Hewko, Mark D.; Dufour, Marc L.; Fulton, Crystal; Qiu, Pingli; Gauthier, Bruno; Padioleau, Christian; Bisaillon, Charles-Etienne; Dong, Cecilia; Cleghorn, Blaine M.; Lamouche, Guy; Sowa, Michael G.

2009-02-01

Optical coherence tomography (OCT) is emerging as a technology that can potentially be used for the detection and monitoring of early dental enamel caries since it can provide high-resolution depth imaging of early lesions. To date, most caries detection optical technologies are well suited for examining caries at facial, lingual, incisal and occlusal surfaces. The approximal surfaces between adjacent teeth are difficult to examine due to lack of visual access and limited space for these new caries detection tools. Using a catheter-style probe developed at the NRC-Industrial Materials Institute, the probe was inserted into the interproximal space to examine the approximal surfaces with OCT imaging at 1310 nm. The probe was rotated continuously and translated axially to generate depth images in a spiral fashion. The probe was used in a mock tooth arch model consisting of extracted human teeth mounted with dental rope wax in their anatomically correct positions. With this ex vivo model, the probe provided images of the approximal surfaces revealing morphological structural details, regions of calculus, and especially regions of early dental caries (white spot lesions). Results were compared with those obtained from OCT imaging of individual samples where the approximal surfaces of extracted teeth are accessible on a lab-bench. Issues regarding access, regions of interest, and factors to be considered in an in vivo setting will be discussed. Future studies are aimed at using the probe in vivo with patient volunteers.

Probe Storage

NARCIS (Netherlands)

Gemelli, Marcellino; Abelmann, Leon; Engelen, Johannes Bernardus Charles; Khatib, M.G.; Koelmans, W.W.; Zaboronski, Olog; Campardo, Giovanni; Tiziani, Federico; Laculo, Massimo

2011-01-01

This chapter gives an overview of probe-based data storage research over the last three decades, encompassing all aspects of a probe recording system. Following the division found in all mechanically addressed storage systems, the different subsystems (media, read/write heads, positioning, data

Creative environments for design education and practice : A typology of creative spaces

NARCIS (Netherlands)

Thoring, K.C.; Desmet, P.M.A.; Badke-Schaub, P.G.

2018-01-01

This article presents a typology of creative spaces that is relevant to facilitating creative working and learning processes for designers. Drawing on qualitative user research with cultural probes in a design thinking institution, this typology identifies five different types of creative spaces

The space-age solar system

International Nuclear Information System (INIS)

Baugher, J.F.

1988-01-01

This book is a description of the sun, planets, moons, asteroids, and comets in the solar system. Discussion is based heavily on results obtained from recent space probes to Mercury, Venus, Mars Jupiter, Saturn, and Uranus. Offers detailed descriptions of the moons of Jupiter and Saturn, and the results of the recent probes of Halley's comet. A discussion of meteorites leads to a description of the current models of the solar system. Introductory chapters present theories of the solar system from the ancient Greeks to the present day. Other topics covered include the sun, its structure, and how it generates energy; the surfaces, internal structures, and histories of the planets, from innermost Mercury to farthest Pluto, and their moons

Tailored Trustworthy Spaces: Solutions for the Smart Grid

Data.gov (United States)

Networking and Information Technology Research and Development, Executive Office of the President — The NITRD workshop on Tailored Trustworthy Spaces: Solutions for the Smart Grid was conceived by the Federal government to probe deeper into how Tailored Trustworthy...

Modular Rake of Pitot Probes

Science.gov (United States)

Dunlap, Timothy A.; Henry, Michael W.; Homyk, Raymond P.

2004-01-01

The figure presents selected views of a modular rake of 17 pitot probes for measuring both transient and steady-state pressures in a supersonic wind tunnel. In addition to pitot tubes visible in the figure, the probe modules contain (1) high-frequency dynamic-pressure transducers connected through wires to remote monitoring circuitry and (2) flow passages that lead to tubes that, in turn, lead to remote steady-state pressure transducers. Prior pitot-probe rakes were fabricated as unitary structures, into which the individual pitot probes were brazed. Repair or replacement of individual probes was difficult, costly, and time-consuming because (1) it was necessary to remove entire rakes in order to unbraze individual malfunctioning probes and (2) the heat of unbrazing a failed probe and of brazing a new probe in place could damage adjacent probes. In contrast, the modules in the present probe are designed to be relatively quickly and easily replaceable with no heating and, in many cases, without need for removal of the entire rake from the wind tunnel. To remove a malfunctioning probe, one first removes a screw-mounted V-cross-section cover that holds the probe and adjacent probes in place. Then one removes a screw-mounted cover plate to gain access to the steady-state pressure tubes and dynamicpressure wires. Next, one disconnects the tube and wires of the affected probe. Finally, one installs a new probe in the reverse of the aforementioned sequence. The wire connections can be made by soldering, but to facilitate removal and installation, they can be made via miniature plugs and sockets. The connections between the probe flow passages and the tubes leading to the remote pressure sensors can be made by use of any of a variety of readily available flexible tubes that can be easily pulled off and slid back on for removal and installation, respectively.

Positioning Reduction of Deep Space Probes Based on VLBI Tracking

Science.gov (United States)

Qiao, S. B.

2011-11-01

) Investigate the application of Kalman filter to the positioning reduction of deep space probes and develop related software systems. In summary, the progress in this dissertation is made in the positioning reduction of deep space probes tracked by VLBI concerning the algorithm study, software development, real observation processing and so on, while a further study is still urgent and arduous.

STM-SQUID probe microscope

International Nuclear Information System (INIS)

Hayashi, Tadayuki; Tachiki, Minoru; Itozaki, Hideo

2007-01-01

We have developed a STM-SQUID probe microscope. A high T C SQUID probe microscope was combined with a scanning tunneling microscope for investigation of samples at room temperature in air. A high permeability probe needle was used as a magnetic flux guide to improve the spatial resolution. The probe with tip radius of less than 100 nm was prepared by microelectropolishing. The probe was also used as a scanning tunneling microscope tip. Topography of the sample surface could be measured by the scanning tunneling microscope with high spatial resolution prior to observation by SQUID microscopy. The SQUID probe microscope image could be observed while keeping the distance from the sample surface to the probe tip constant. We observed a topographic image and a magnetic image of Ni fine pattern and also a magnetically recorded hard disk. Furthermore we have investigated a sample vibration method of the static magnetic field emanating from a sample with the aim of achieving a higher signal-to-noise (S/N) ratio

Characterization of coating probe with Ti-DLC for electrical scanning probe microscope

International Nuclear Information System (INIS)

Shia Xiaolei; Guo Liqiu; Bai Yang; Qiao Lijie

2011-01-01

In electrical scanning probe microscope (ESPM) applications, the wear and conductivity of the probe are undoubtedly serious concerns since they affect the integrity of the measurements. This study investigates the characterization of Ti doped diamond-like-carbon (DLC) as coating material on a silicon cantilever for ESPM. We deposited a layer of Ti-DLC thin film on the surface of Si cantilever by magnetron sputtering. The morphology and composition of the Ti-DLC films were characterized by scanning electron microscopy and Raman spectroscopy, respectively. We also compared the wear resistance, electric conductivity and scanning image quality of the Ti-DLC-coated probes with those of commercially available conductive probes. The results showed that the electric conductivity and the scanning image quality of the Ti-DLC-coated probes were the same as the commercial conductive probes, while the wear resistance and service life was significantly better.

Design of triads for probing the direct through space energy transfers in closely spaced assemblies.

Science.gov (United States)

Camus, Jean-Michel; Aly, Shawkat M; Fortin, Daniel; Guilard, Roger; Harvey, Pierre D

2013-08-05

Using a selective stepwise Suzuki cross-coupling reaction, two trimers built on three different chromophores were prepared. These trimers exhibit a D(^)A1-A2 structure where the donor D (octa-β-alkyl zinc(II)porphyrin either as diethylhexamethyl, 10a, or tetraethyltetramethyl, 10b, derivatives) through space transfers the S1 energy to two different acceptors, di(4-ethylbenzene) zinc(II)porphyrin (A1; acceptor 1) placed cofacial with D, and the corresponding free base (A2; acceptor 2), which is meso-meso-linked with A1. This structure design allows for the possibility of comparing two series of assemblies, 9a,b (D(^)A1) with 10a,b (D(^)Â1-A2), for the evaluation of the S1 energy transfer for the global process D*→A2 in the trimers. From the comparison of the decays of the fluorescence of D, the rates for through space energy transfer, kET for 10a,b (kET ≈ 6.4 × 10(9) (10a), 5.9 × 10(9) s(-1) (10b)), and those for the corresponding cofacial D(^)A1 systems, 9a,b, (kET ≈ 5.0 × 10(9) (9a), 4.7 × 10(9) s(-1) (9b)), provide an estimate for kET for the direct through space D*→A2 process (i.e., kET(D(^)A1-A2) - kET(D(^)A1) = kET(D*→A2) ∼ 1 × 10(9) s(-1)). This channel of relaxation represents ∼15% of kET for D*→A1.

Emerging Space Powers The New Space Programs of Asia, the Middle East, and South America

CERN Document Server

Harvey, Brian; Pirard, Théo

2010-01-01

This work introduces the important emerging space powers of the world. Brian Harvey describes the origins of the Japanese space program, from rocket designs based on WW II German U-boats to tiny solid fuel 'pencil' rockets, which led to the launch of the first Japanese satellite in 1970. The next two chapters relate how Japan expanded its space program, developing small satellites into astronomical observatories and sending missions to the Moon, Mars, comet Halley, and asteroids. Chapter 4 describes how India's Vikram Sarabhai developed a sounding rocket program in the 1960s. The following chapter describes the expansion of the Indian space program. Chapter 6 relates how the Indian space program is looking ahead to the success of the moon probe Chandrayan, due to launch in 2008, and its first manned launching in 2014. Chapters 7, 8, and 9 demonstrate how, in Iran, communications and remote sensing drive space technology. Chapter 10 outlines Brazil's road to space, begun in the mid-1960's with the launch of th...

Probing the dispersion properties of 1D nanophotonic waveguides with far-field Fourier optics

DEFF Research Database (Denmark)

Le Thomas, N.; Jágerská, J.; Houdré, R.

2008-01-01

We present an advanced Fourier space imaging technique to probe guided light in nanophotonic structures with an effective numerical aperture of 2.5. This superresolution technique allows us to successfully investigate the dispersive properties of 1D nanowaveguides such as photonic crystal W1...

Proximal Probes Facility

Data.gov (United States)

Federal Laboratory Consortium — The Proximal Probes Facility consists of laboratories for microscopy, spectroscopy, and probing of nanostructured materials and their functional properties. At the...

Image correlation spectroscopy: mapping correlations in space, time, and reciprocal space.

Science.gov (United States)

Wiseman, Paul W

2013-01-01

This chapter presents an overview of two recent implementations of image correlation spectroscopy (ICS). The background theory is presented for spatiotemporal image correlation spectroscopy and image cross-correlation spectroscopy (STICS and STICCS, respectively) as well as k-(reciprocal) space image correlation spectroscopy (kICS). An introduction to the background theory is followed by sections outlining procedural aspects for properly implementing STICS, STICCS, and kICS. These include microscopy image collection, sampling in space and time, sample and fluorescent probe requirements, signal to noise, and background considerations that are all required to properly implement the ICS methods. Finally, procedural steps for immobile population removal and actual implementation of the ICS analysis programs to fluorescence microscopy image time stacks are described. Copyright © 2013 Elsevier Inc. All rights reserved.

A single-probe heat pulse method for estimating sap velocity in trees.

Science.gov (United States)

López-Bernal, Álvaro; Testi, Luca; Villalobos, Francisco J

2017-10-01

Available sap flow methods are still far from being simple, cheap and reliable enough to be used beyond very specific research purposes. This study presents and tests a new single-probe heat pulse (SPHP) method for monitoring sap velocity in trees using a single-probe sensor, rather than the multi-probe arrangements used up to now. Based on the fundamental conduction-convection principles of heat transport in sapwood, convective velocity (V h ) is estimated from the temperature increase in the heater after the application of a heat pulse (ΔT). The method was validated against measurements performed with the compensation heat pulse (CHP) technique in field trees of six different species. To do so, a dedicated three-probe sensor capable of simultaneously applying both methods was produced and used. Experimental measurements in the six species showed an excellent agreement between SPHP and CHP outputs for moderate to high flow rates, confirming the applicability of the method. In relation to other sap flow methods, SPHP presents several significant advantages: it requires low power inputs, it uses technically simpler and potentially cheaper instrumentation, the physical damage to the tree is minimal and artefacts caused by incorrect probe spacing and alignment are removed. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

DESTINY, The Dark Energy Space Telescope

Science.gov (United States)

Pasquale, Bert A.; Woodruff, Robert A.; Benford, Dominic J.; Lauer, Tod

2007-01-01

We have proposed the development of a low-cost space telescope, Destiny, as a concept for the NASA/DOE Joint Dark Energy Mission. Destiny is a 1.65m space telescope, featuring a near-infrared (0.85-1.7m) survey camera/spectrometer with a moderate flat-field field of view (FOV). Destiny will probe the properties of dark energy by obtaining a Hubble diagram based on Type Ia supernovae and a large-scale mass power spectrum derived from weak lensing distortions of field galaxies as a function of redshift.

Intra-albumin migration of bound fatty acid probed by spin label ESR

International Nuclear Information System (INIS)

Gurachevsky, Andrey; Shimanovitch, Ekaterina; Gurachevskaya, Tatjana; Muravsky, Vladimir

2007-01-01

Conventional ESR spectra of 16-doxyl-stearic acid bound to bovine and human serum albumin were recorded at different temperatures in order to investigate the status of spin-labeled fatty acid in the interior of the protein globule. A computer spectrum simulation of measured spectra, performed by non-linear least-squares fits, clearly showed two components corresponding to strongly and weakly immobilized fatty acid molecules. The two-component model was verified on spectra measured at different pH. Thermodynamic parameters of the spin probe exchange between two spin probe states were analyzed. It was concluded that at physiological conditions, fatty acid molecules permanently migrate in the globule interior between the specific binding sites and a space among albumin domains

Development of conductivity probe and temperature probe for in-situ measurements in hydrological studies

International Nuclear Information System (INIS)

Chandra, U.; Galindo, B.J.; Castagnet, A.C.G.

1981-05-01

A conductivity probe and a temperature probe have been developed for in-situ measurements in various hydrological field studies. The conductivity probe has platinum electrodes and is powered with two 12 volt batteries. The sensing element of the temperature probe consists of a resistor of high coefficient of temperature. Response of the conductivity probe is measured in a milliampere mater while the resistance of the thermistor is read by a digital meter. The values of conductivity and temperature are derived from respective calibration. The probes are prototype and their range of measurement can be improved depending upon the requirement of the field problem. (Author) [pt

Helix probe areas for the utilization of geothermal power. A practical example; Helix-Sondenfelder zur Nutzung von Erdwaerme. Ein Praxisbeispiel

Energy Technology Data Exchange (ETDEWEB)

Kuebert, Markus; Walker-Hertkorn, Simone [tewag Technologie - Erdwaermeanlagen - Umweltschutz GmbH, Starzach (Germany); Tietz, Jan [REHAU AG und Co., Erlangen-Eltersdorf (Germany); Riepold, Markus; Gloeckl, Andreas [MR Tiefbau GmbH, Brunnen (Germany)

2013-02-01

Thanks to their spiral shape so-called helix probes with a tube length of 40 meter have a height of only three meter: A lot of heat exchange area in a small space. Thus, helix probes are an ideal solution for the utilization of geothermal energy at places at which one cannot drill deeply due to geothermal reasons. Under this aspect, the contribution under consideration reports on the planning of a helix probe area being sustainably adapted to the user requirements for the new construction of a production facility.

Laser-heated emissive plasma probe.

Science.gov (United States)

Schrittwieser, Roman; Ionita, Codrina; Balan, Petru; Gstrein, Ramona; Grulke, Olaf; Windisch, Thomas; Brandt, Christian; Klinger, Thomas; Madani, Ramin; Amarandei, George; Sarma, Arun K

2008-08-01

Emissive probes are standard tools in laboratory plasmas for the direct determination of the plasma potential. Usually they consist of a loop of refractory wire heated by an electric current until sufficient electron emission. Recently emissive probes were used also for measuring the radial fluctuation-induced particle flux and other essential parameters of edge turbulence in magnetized toroidal hot plasmas [R. Schrittwieser et al., Plasma Phys. Controlled Fusion 50, 055004 (2008)]. We have developed and investigated various types of emissive probes, which were heated by a focused infrared laser beam. Such a probe has several advantages: higher probe temperature without evaporation or melting and thus higher emissivity and longer lifetime, no deformation of the probe in a magnetic field, no potential drop along the probe wire, and faster time response. The probes are heated by an infrared diode laser with 808 nm wavelength and an output power up to 50 W. One probe was mounted together with the lens system on a radially movable probe shaft, and radial profiles of the plasma potential and of its oscillations were measured in a linear helicon discharge.

Laser-heated emissive plasma probe

International Nuclear Information System (INIS)

Schrittwieser, Roman; Ionita, Codrina; Balan, Petru; Gstrein, Ramona; Grulke, Olaf; Windisch, Thomas; Brandt, Christian; Klinger, Thomas; Madani, Ramin; Amarandei, George; Sarma, Arun K.

2008-01-01

Emissive probes are standard tools in laboratory plasmas for the direct determination of the plasma potential. Usually they consist of a loop of refractory wire heated by an electric current until sufficient electron emission. Recently emissive probes were used also for measuring the radial fluctuation-induced particle flux and other essential parameters of edge turbulence in magnetized toroidal hot plasmas [R. Schrittwieser et al., Plasma Phys. Controlled Fusion 50, 055004 (2008)]. We have developed and investigated various types of emissive probes, which were heated by a focused infrared laser beam. Such a probe has several advantages: higher probe temperature without evaporation or melting and thus higher emissivity and longer lifetime, no deformation of the probe in a magnetic field, no potential drop along the probe wire, and faster time response. The probes are heated by an infrared diode laser with 808 nm wavelength and an output power up to 50 W. One probe was mounted together with the lens system on a radially movable probe shaft, and radial profiles of the plasma potential and of its oscillations were measured in a linear helicon discharge

Laser-heated emissive plasma probe

Science.gov (United States)

Schrittwieser, Roman; Ionita, Codrina; Balan, Petru; Gstrein, Ramona; Grulke, Olaf; Windisch, Thomas; Brandt, Christian; Klinger, Thomas; Madani, Ramin; Amarandei, George; Sarma, Arun K.

2008-08-01

Emissive probes are standard tools in laboratory plasmas for the direct determination of the plasma potential. Usually they consist of a loop of refractory wire heated by an electric current until sufficient electron emission. Recently emissive probes were used also for measuring the radial fluctuation-induced particle flux and other essential parameters of edge turbulence in magnetized toroidal hot plasmas [R. Schrittwieser et al., Plasma Phys. Controlled Fusion 50, 055004 (2008)]. We have developed and investigated various types of emissive probes, which were heated by a focused infrared laser beam. Such a probe has several advantages: higher probe temperature without evaporation or melting and thus higher emissivity and longer lifetime, no deformation of the probe in a magnetic field, no potential drop along the probe wire, and faster time response. The probes are heated by an infrared diode laser with 808nm wavelength and an output power up to 50W. One probe was mounted together with the lens system on a radially movable probe shaft, and radial profiles of the plasma potential and of its oscillations were measured in a linear helicon discharge.

Gravity Probe B Completed With Solar Arrays

Science.gov (United States)

2004-01-01

In this photo, the Gravity Probe B (GP-B) space vehicle is completed during the solar array installation. The GP-B is the relativity experiment developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies that are already enlivening other branches of science and engineering. GP-B is scheduled for launch in April 2004 and managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Russ Underwood, Lockheed Martin Corporation).

Interstellar Probe: First Step to the Stars

Science.gov (United States)

McNutt, R. L., Jr.

2017-12-01

The idea of an "Interstellar Probe," a robotic spacecraft traveling into the nearby interstellar medium for the purpose of scientific investigation, dates to the mid-1960s. The Voyager Interstellar Mission (VIM), an "accidental" 40-year-old by-product of the Grand Tour of the solar system, has provided initial answers to the problem of the global heliospheric configuration and the details of its interface with interstellar space. But the twin Voyager spacecraft have, at most, only another decade of lifetime, and only Voyager 1 has emerged from the heliosheath interaction region. To understand the nature of the interaction, a near-term mission to the "near-by" interstellar medium with modern and focused instrumentation remains a compelling priority. Imaging of energetic neutral atoms (ENAs) by the Ion Neutral CAmera (INCA) on Cassini and from the Interstellar Boundary Explorer (IBEX) in Earth orbit have provided significant new insights into the global interaction region but point to discrepancies with our current understanding. Exploring "as far as possible" into "pristine" interstellar space can resolve these. Hence, reaching large heliocentric distances rapidly is a driver for an Interstellar Probe. Such a mission is timely; understanding the interstellar context of exoplanet systems - and perhaps the context for the emergence of life both here and there - hinges upon what we can discover within our own stellar neighborhood. With current spacecraft technology and high-capability launch vehicles, such as the Space Launch System (SLS), a small, but extremely capable spacecraft, could be dispatched to the near-by interstellar medium with at least twice the speed of the Voyagers. Challenges remain with payload mass and power constraints for optimized science measurements. Mission longevity, as experienced by, but not designed into, the Voyagers, communications capability, and radioisotope power system performance and lifetime are solvable engineering challenges. Such

Innovative SPM Probes for Energy-Storage Science: MWCNT-Nanopipettes to Nanobattery Probes

Science.gov (United States)

Larson, Jonathan; Talin, Alec; Pearse, Alexander; Kozen, Alexander; Reutt-Robey, Janice

As energy-storage materials and designs continue to advance, new tools are needed to direct and explore ion insertion/de-insertion at well-defined battery materials interfaces. Scanned probe tips, assembled from actual energy-storage materials, permit SPM measures of local cathode-anode (tip-sample) interactions, including ion transfer. We present examples of ``cathode'' MWCNT-terminated STM probe tips interacting with Li(s)/Si(111) anode substrates. The MWCNT tip functions as both SPM probe and Li-nanopipette,[1] for controlled transport and manipulation of Li. Local field conditions for lithium ionization and transfer are determined and compared to electrostatic models. Additional lithium metallic and oxide tips have been prepared by thin film deposition on conventional W tips, the latter of which effectively functions as a nanobattery. We demonstrate use of these novel probe materials in the local lithiation of low-index Si anode interfaces, probing local barriers for lithium insertion. Prospects and limitations of these novel SPM probes will be discussed. U.S. Department of Energy Award Number DESC0001160.

Theory of NMR probe design

International Nuclear Information System (INIS)

Schnall, M.D.

1988-01-01

The NMR probe is the intrinsic part of the NMR system which allows transmission of a stimulus to a sample and the reception of a resulting signal from a sample. NMR probes are used in both imaging and spectroscopy. Optimal probe design is important to the production of adequate signal/moise. It is important for anyone using NMR techniques to understand how NMR probes work and how to optimize probe design

Van Allen Probes Science Gateway: Single-Point Access to Long-Term Radiation Belt Measurements and Space Weather Nowcasting

Science.gov (United States)

Romeo, G.; Barnes, R. J.; Ukhorskiy, A. Y.; Sotirelis, T.; Stephens, G.

2017-12-01

The Science Gateway gives single-point access to over 4.5 years of comprehensive wave and particle measurements from the Van Allen Probes NASA twin-spacecraft mission. The Gateway provides a set of visualization and data analysis tools including: HTML5-based interactive visualization of high-level data products from all instrument teams in the form of: line plots, orbital content plots, dynamical energy spectra, L-shell context plots (including two-spacecraft plotting), FFT spectra of wave data, solar wind and geomagnetic indices data, etc.; download custom multi-instrument CDF data files of selected data products; publication quality plots of digital data; combined orbit predicts for mission planning and coordination including: Van Allen Probes, MMS, THEMIS, Arase (ERG), Cluster, GOES, Geotail, FIREBIRD; magnetic footpoint calculator for coordination with LEO and ground-based assets; real-time computation and processing of empirical magnetic field models - computation of magnetic ephemeris, computation of adiabatic invariants. Van Allen Probes is the first spacecraft mission to provide a nowcast of the radiation environment in the heart of the radiation belts, where the radiation levels are the highest and most dangerous for spacecraft operations. For this purpose, all instruments continuously broadcast a subset of their science data in real time. Van Allen Probes partners with four foreign institutions who operate ground stations that receive the broadcast: Korea (KASI), the Czech republic (CAS), Argentina (CONAE), and Brazil (INPE). The SpWx broadcast is then collected at APL and delivered to the community via the Science Gateway.

Ciudadanía y sustentabilidad ambiental en la ciudad: la recuperación del humedal Angachilla y la organización local en la Villa Claro de Luna, Valdivia, Chile

Directory of Open Access Journals (Sweden)

Juan C Skewes

2012-01-01

Full Text Available La recuperación del humedal Angachilla por la junta de vecinos de la Villa Claro de Luna en la ciudad de Valdivia constituye un ejercicio donde se yuxtaponen la preocupación ambiental y el ejercicio de la soberanía ciudadana. Por medio de su organización, los residentes logran, por una parte, contribuir a la protección del medio ambiente; y por la otra, incrementar su participación en los procesos urbanos de una ciudad intermedia. A partir del redescubrimiento de las relaciones con la naturaleza, la comunidad amplía sus repertorios de significación y elabora nuevas formas de valorización del territorio basadas en la extensión de su cotidianidad y en las dinámicas de vida asociadas al paisaje n atural, las cuales permiten la incorporación de la naturaleza a la ciudad.

Holography, probe branes and isoperimetric inequalities

Directory of Open Access Journals (Sweden)

Frank Ferrari

2015-07-01

Full Text Available In many instances of holographic correspondences between a d-dimensional boundary theory and a (d+1-dimensional bulk, a direct argument in the boundary theory implies that there must exist a simple and precise relation between the Euclidean on-shell action of a (d−1-brane probing the bulk geometry and the Euclidean gravitational bulk action. This relation is crucial for the consistency of holography, yet it is non-trivial from the bulk perspective. In particular, we show that it relies on a nice isoperimetric inequality that must be satisfied in a large class of Poincaré–Einstein spaces. Remarkably, this inequality follows from theorems by Lee and Wang.

Cultural probes

DEFF Research Database (Denmark)

Madsen, Jacob Østergaard

The aim of this study was thus to explore cultural probes (Gaver, Boucher et al. 2004), as a possible methodical approach, supporting knowledge production on situated and contextual aspects of occupation.......The aim of this study was thus to explore cultural probes (Gaver, Boucher et al. 2004), as a possible methodical approach, supporting knowledge production on situated and contextual aspects of occupation....

RADIO-FREQUENCY MASS SPECTROMETERS AND THEIR APPLICATIONS IN SPACE

Energy Technology Data Exchange (ETDEWEB)

Gilmour, Jr., A. S.

1963-08-15

The operation of three common radio-frequency mass spectrometers is described, and their performances are compared. Their limitations are pointed out. It is concluded that the quadrupole spectrometer has fewer limitations and is more generally useful in space probes than the other devices. Some present and proposed uses of spectrometers in space are discussed, and the problem of contamination of the atmosphere being sampled by the spectrometer is reviewed. (auth)

Probing a dark photon using rare leptonic kaon and pion decays

Directory of Open Access Journals (Sweden)

Cheng-Wei Chiang

2017-04-01

Full Text Available Rare leptonic kaon and pion decays K+(π+→μ+νμe+e− can be used to probe a dark photon of mass O(10 MeV, with the background coming from the mediation of a virtual photon. This is most relevant for the 16.7-MeV dark photon proposed to explain a 6.8σ anomaly recently observed in 8Be transitions by the Atomki Collaboration. We evaluate the reach of future experiments for the dark photon with vectorial couplings to the standard model fermions except for the neutrinos, and show that a great portion of the preferred 16.7-MeV dark photon parameter space can be decisively probed. We also show the use of angular distributions to further distinguish the signal from the background.

Invited Review Article: Pump-probe microscopy

Science.gov (United States)

Wilson, Jesse W.; Robles, Francisco E.; Warren, Warren S.

2016-01-01

Multiphoton microscopy has rapidly gained popularity in biomedical imaging and materials science because of its ability to provide three-dimensional images at high spatial and temporal resolution even in optically scattering environments. Currently the majority of commercial and home-built devices are based on two-photon fluorescence and harmonic generation contrast. These two contrast mechanisms are relatively easy to measure but can access only a limited range of endogenous targets. Recent developments in fast laser pulse generation, pulse shaping, and detection technology have made accessible a wide range of optical contrasts that utilize multiple pulses of different colors. Molecular excitation with multiple pulses offers a large number of adjustable parameters. For example, in two-pulse pump-probe microscopy, one can vary the wavelength of each excitation pulse, the detection wavelength, the timing between the excitation pulses, and the detection gating window after excitation. Such a large parameter space can provide much greater molecular specificity than existing single-color techniques and allow for structural and functional imaging without the need for exogenous dyes and labels, which might interfere with the system under study. In this review, we provide a tutorial overview, covering principles of pump-probe microscopy and experimental setup, challenges associated with signal detection and data processing, and an overview of applications. PMID:27036751

Invited Review Article: Pump-probe microscopy

Energy Technology Data Exchange (ETDEWEB)

Fischer, Martin C., E-mail: Martin.Fischer@duke.edu; Wilson, Jesse W.; Robles, Francisco E. [Department of Chemistry, Duke University, Durham, North Carolina 27708 (United States); Warren, Warren S. [Departments of Chemistry, Biomedical Engineering, Physics, and Radiology, Duke University, Durham, North Carolina 27708 (United States)

2016-03-15

Multiphoton microscopy has rapidly gained popularity in biomedical imaging and materials science because of its ability to provide three-dimensional images at high spatial and temporal resolution even in optically scattering environments. Currently the majority of commercial and home-built devices are based on two-photon fluorescence and harmonic generation contrast. These two contrast mechanisms are relatively easy to measure but can access only a limited range of endogenous targets. Recent developments in fast laser pulse generation, pulse shaping, and detection technology have made accessible a wide range of optical contrasts that utilize multiple pulses of different colors. Molecular excitation with multiple pulses offers a large number of adjustable parameters. For example, in two-pulse pump-probe microscopy, one can vary the wavelength of each excitation pulse, the detection wavelength, the timing between the excitation pulses, and the detection gating window after excitation. Such a large parameter space can provide much greater molecular specificity than existing single-color techniques and allow for structural and functional imaging without the need for exogenous dyes and labels, which might interfere with the system under study. In this review, we provide a tutorial overview, covering principles of pump-probe microscopy and experimental setup, challenges associated with signal detection and data processing, and an overview of applications.

In-Space Propulsion Engine Architecture based on Sublimation of Planetary Resources: From Exploration Robots to NEO Mitigation

Data.gov (United States)

National Aeronautics and Space Administration — The sources of power used for deep space probe missions are usually derived from either solar panels for electrical energy, radioisotope thermal generators for...

Dual-probe decoherence microscopy: probing pockets of coherence in a decohering environment

International Nuclear Information System (INIS)

Jeske, Jan; Cole, Jared H; Müller, Clemens; Marthaler, Michael; Schön, Gerd

2012-01-01

We study the use of a pair of qubits as a decoherence probe of a nontrivial environment. This dual-probe configuration is modelled by three two-level systems (TLSs), which are coupled in a chain in which the middle system represents an environmental TLS. This TLS resides within the environment of the qubits and therefore its coupling to perturbing fluctuations (i.e. its decoherence) is assumed much stronger than the decoherence acting on the probe qubits. We study the evolution of such a tripartite system including the appearance of a decoherence-free state (dark state) and non-Markovian behaviour. We find that all parameters of this TLS can be obtained from measurements of one of the probe qubits. Furthermore, we show the advantages of two qubits in probing environments and the new dynamics imposed by a TLS that couples to two qubits at once. (paper)

Sensor probes and phantoms for advanced transcranial magnetic stimulation system developments

Science.gov (United States)

Meng, Qinglei; Patel, Prashil; Trivedi, Sudhir; Du, Xiaoming; Hong, Elliot; Choa, Fow-Sen

2015-05-01

Transcranial magnetic stimulation (TMS) has become one of the most widely used noninvasive method for brain tissue stimulation and has been used as a treatment tool for various neurological and psychiatric disorders including migraine, stroke, Parkinson's disease, dystonia, tinnitus and depression. In the process of developing advanced TMS deep brain stimulation tools, we need first to develop field measurement devices like sensory probes and brain phantoms, which can be used to calibrate the TMS systems. Currently there are commercially available DC magnetic or electric filed measurement sensors, but there is no instrument to measure transient fields. In our study, we used a commercial figure-8 shaped TMS coil to generate transient magnetic field and followed induced field and current. The coil was driven by power amplified signal from a pulse generator with tunable pulse rate, amplitude, and duration. In order to obtain a 3D plot of induced vector electric field, many types of probes were designed to detect single component of electric-field vectors along x, y and z axis in the space around TMS coil. We found that resistor probes has an optimized signal-to-noise ratio (SNR) near 3k ohm but it signal output is too weak compared with other techniques. We also found that inductor probes can have very high output for Curl E measurement, but it is not the E-field distribution we are interested in. Probes with electrical wire wrapped around iron coil can directly measure induced E-field with high sensitivity, which matched computer simulation results.

An Experimental Concept for Probing Nonlinear Physics in Radiation Belts

Science.gov (United States)

Crabtree, C. E.; Ganguli, G.; Tejero, E. M.; Amatucci, B.; Siefring, C. L.

2017-12-01

A sounding rocket experiment, Space Measurement of Rocket-Released Turbulence (SMART), can be used to probe the nonlinear response to a known stimulus injected into the radiation belt. Release of high-speed neutral barium atoms (8- 10 km/s) generated by a shaped charge explosion in the ionosphere can be used as the source of free energy to seed weak turbulence in the ionosphere. The Ba atoms are photo-ionized forming a ring velocity distribution of heavy Ba+ that is known to generate lower hybrid waves. Induced nonlinear scattering will convert the lower hybrid waves into EM whistler/magnetosonic waves. The escape of the whistlers from the ionospheric region into the radiation belts has been studied and their observable signatures quantified. The novelty of the SMART experiment is to make coordinated measurement of the cause and effect of the turbulence in space plasmas and from that to deduce the role of nonlinear scattering in the radiation belts. Sounding rocket will carry a Ba release module and an instrumented daughter section that includes vector wave magnetic and electric field sensors, Langmuir probes and energetic particle detectors. The goal of these measurements is to determine the whistler and lower hybrid wave amplitudes and spectrum in the ionospheric source region and look for precipitated particles. The Ba release may occur at 600-700 km near apogee. Ground based cameras and radio diagnostics can be used to characterize the Ba and Ba+ release. The Van Allen Probes can be used to detect the propagation of the scattering-generated whistler waves and their effects in the radiation belts. By detecting whistlers and measuring their energy density in the radiation belts the SMART mission will confirm the nonlinear generation of whistlers through scattering of lower hybrid along with other nonlinear responses of the radiation belts and their connection to weak turbulence.

Enhanced fluorescence imaging of live cells by effective cytosolic delivery of probes.

Directory of Open Access Journals (Sweden)

Marzia Massignani

Full Text Available BACKGROUND: Microscopic techniques enable real-space imaging of complex biological events and processes. They have become an essential tool to confirm and complement hypotheses made by biomedical scientists and also allow the re-examination of existing models, hence influencing future investigations. Particularly imaging live cells is crucial for an improved understanding of dynamic biological processes, however hitherto live cell imaging has been limited by the necessity to introduce probes within a cell without altering its physiological and structural integrity. We demonstrate herein that this hurdle can be overcome by effective cytosolic delivery. PRINCIPAL FINDINGS: We show the delivery within several types of mammalian cells using nanometre-sized biomimetic polymer vesicles (a.k.a. polymersomes that offer both highly efficient cellular uptake and endolysomal escape capability without any effect on the cellular metabolic activity. Such biocompatible polymersomes can encapsulate various types of probes including cell membrane probes and nucleic acid probes as well as labelled nucleic acids, antibodies and quantum dots. SIGNIFICANCE: We show the delivery of sufficient quantities of probes to the cytosol, allowing sustained functional imaging of live cells over time periods of days to weeks. Finally the combination of such effective staining with three-dimensional imaging by confocal laser scanning microscopy allows cell imaging in complex three-dimensional environments under both mono-culture and co-culture conditions. Thus cell migration and proliferation can be studied in models that are much closer to the in vivo situation.

The Gravity Probe B experiment and early results

Energy Technology Data Exchange (ETDEWEB)

Conklin, John W [Stanford University (United States)], E-mail: johnwc@stanford.edu

2008-11-01

The NASA Gravity Probe B orbiting gyroscope test of General Relativity, launched from Vandenberg Air Force Base on 20 April, 2004 tests two consequences of Einstein's theory: 1) the predicted 6.6 arcs/yr geodetic effect due to the motion of the gyroscope through the curved space-time around the Earth; 2) the predicted 0.039 arcs/yr frame-dragging effect due to the rotating Earth. The mission required the development of many technologies that did not exist when experiment was conceived in 1960. Cryogenic gyroscopes with drift-rates 7 orders of magnitude better than the best inertial navigation gyroscopes, a < 1 marcs star tracking telescope, and other essential technologies were developed as a result of an intensive collaboration between Stanford physicists and engineers, NASA and industry. Gravity Probe B collected science data from August 27, 2004 through September 29, 2005. Analysis of the data began during the mission and is on-going. This paper describes the main features and challenges of the experiment and presents the preliminary results to date.

The Gravity Probe B experiment and early results

International Nuclear Information System (INIS)

Conklin, John W

2008-01-01

The NASA Gravity Probe B orbiting gyroscope test of General Relativity, launched from Vandenberg Air Force Base on 20 April, 2004 tests two consequences of Einstein's theory: 1) the predicted 6.6 arcs/yr geodetic effect due to the motion of the gyroscope through the curved space-time around the Earth; 2) the predicted 0.039 arcs/yr frame-dragging effect due to the rotating Earth. The mission required the development of many technologies that did not exist when experiment was conceived in 1960. Cryogenic gyroscopes with drift-rates 7 orders of magnitude better than the best inertial navigation gyroscopes, a < 1 marcs star tracking telescope, and other essential technologies were developed as a result of an intensive collaboration between Stanford physicists and engineers, NASA and industry. Gravity Probe B collected science data from August 27, 2004 through September 29, 2005. Analysis of the data began during the mission and is on-going. This paper describes the main features and challenges of the experiment and presents the preliminary results to date.

Model for resonant plasma probe.

Energy Technology Data Exchange (ETDEWEB)

Warne, Larry Kevin; Johnson, William Arthur; Hebner, Gregory Albert; Jorgenson, Roy E.; Coats, Rebecca Sue

2007-04-01

This report constructs simple circuit models for a hairpin shaped resonant plasma probe. Effects of the plasma sheath region surrounding the wires making up the probe are determined. Electromagnetic simulations of the probe are compared to the circuit model results. The perturbing effects of the disc cavity in which the probe operates are also found.

Ex Luna Scientia: The Lunar Occultation Explorer (LOX)

Science.gov (United States)

Miller, Richard

2017-01-01

The Lunar Occultation Explorer (LOX) is a next-generation mission concept that provides new capabilities for time-domain astrophysics and established the Moon as a platform for nuclear astrophysics. Performance requirements are driven by Type-Ia supernova (SNeIa) science goals that seek to revel details of these profoundly radioactive objects, including their diversity. Primary science objectives include, but are not limited to, probing the fundamental thermonuclear physics processes, performing a census of progenitors and their explosion mechanisms, and evaluating the environmental conditions and intrinsic systematics of these enigmatic objects. LOX provides new capabilities for all-sky, continuous monitoring in the MeV regime (0.1-10 MeV) by leveraging the Lunar Occultation Technique (LOT). Key benefits of the LOX/LOT approach include maximizing the ratio of sensitive-to-total deployed mass, low implementation risk, and demonstrated operational simplicity that leverages extensive experience with planetary orbital geochemistry investigations; LOX also enables long-term monitoring of MeV gamma-ray sources, a critical capability for SNeIa science. Proof-of-principle efforts validated all aspects of the mission using previously deployed lunar science assets, and led to the first high-energy gamma-ray source detected at the Moon. LOX mission performance, development progress, and expectations for science investigations will be presented.

Quantum space and quantum completeness

Science.gov (United States)

Jurić, Tajron

2018-05-01

Motivated by the question whether quantum gravity can "smear out" the classical singularity we analyze a certain quantum space and its quantum-mechanical completeness. Classical singularity is understood as a geodesic incompleteness, while quantum completeness requires a unique unitary time evolution for test fields propagating on an underlying background. Here the crucial point is that quantum completeness renders the Hamiltonian (or spatial part of the wave operator) to be essentially self-adjoint in order to generate a unique time evolution. We examine a model of quantum space which consists of a noncommutative BTZ black hole probed by a test scalar field. We show that the quantum gravity (noncommutative) effect is to enlarge the domain of BTZ parameters for which the relevant wave operator is essentially self-adjoint. This means that the corresponding quantum space is quantum complete for a larger range of BTZ parameters rendering the conclusion that in the quantum space one observes the effect of "smearing out" the singularity.

Characterization of near-field optical probes

DEFF Research Database (Denmark)

Vohnsen, Brian; Bozhevolnyi, Sergey I.

1999-01-01

Radiation and collection characteristics of four different near-field optical-fiber probes, namely, three uncoated probes and an aluminium-coated small-aperture probe, are investigated and compared. Their radiation properties are characterized by observation of light-induced topography changes...... in a photo-sensitive film illuminated with the probes, and it is confirmed that the radiated optical field is unambigiously confined only for the coated probe. Near-field optical imaging of a standing evanescent-wave pattern is used to compare the detection characteristics of the probes, and it is concluded...... that, for the imaging of optical-field intensity distributions containing predominantly evanescent-wave components, a sharp uncoated tip is the probe of choice. Complementary results obtained with optical phase-conjugation experiments with he uncoated probes are discussed in relation to the probe...

Gas chromatography in space

Science.gov (United States)

Akapo, S. O.; Dimandja, J. M.; Kojiro, D. R.; Valentin, J. R.; Carle, G. C.

1999-01-01

Gas chromatography has proven to be a very useful analytical technique for in situ analysis of extraterrestrial environments as demonstrated by its successful operation on spacecraft missions to Mars and Venus. The technique is also one of the six scientific instruments aboard the Huygens probe to explore Titan's atmosphere and surface. A review of gas chromatography in previous space missions and some recent developments in the current environment of fiscal constraints and payload size limitations are presented.

Evaluation of the Gen-Probe DNA probe for the detection of legionellae in culture

International Nuclear Information System (INIS)

Edelstein, P.H.

1986-01-01

A commercial DNA probe kit designed to detect rRNA from legionellae was evaluated for its ability to correctly discriminate between legionellae and non-legionellae taken from culture plates. The probe kit, made by the Gen-Probe Corp. (San Diego, Calif.), was radiolabeled with 125 I, and probe bacterial RNA hybridization, detected in a simple one-tube system hybridization assay, was quantitated with a gamma counter. A total of 156 Legionella sp. strains were tested, of which 125 were Legionella pneumophila and the remainder were strains from 21 other Legionella spp. A total of 106 gram-negative non-legionellae, isolated from human respiratory tract (81%) and other body site (19%) specimens, were also tested; 14 genera and 28 species were represented. The probe easily distinguished all of the legionellae from the non-legionellae. The average legionellae/non-legionellae hybridization ratio was 42:1, and the lowest ratio was 2:1; a minor modification in the procedure increased the lowest ratio to 5:1. In addition to correctly identifying all Legionella species, the probe was able to separate some of the various species of Legionella. L. pneumophila strains hybridized more completely to the probe than did the other Legionella spp.; L. wadsworthii and L. oakridgensis hybridized only about 25% of the probe relative to L. pneumophila. Some strains of phenotypically identified L. pneumophila had much lower hybridization to the probe than other members of the species and may represent a new Legionella species. The simplicity of the technique and specificity of the probe make it a good candidate for confirming the identity of legionellae in culture

Where do pulse oximeter probes break?

Science.gov (United States)

Crede, S; Van der Merwe, G; Hutchinson, J; Woods, D; Karlen, W; Lawn, J

2014-06-01

Pulse oximetry, a non-invasive method for accurate assessment of blood oxygen saturation (SPO2), is an important monitoring tool in health care facilities. However, it is often not available in many low-resource settings, due to expense, overly sophisticated design, a lack of organised procurement systems and inadequate medical device management and maintenance structures. Furthermore medical devices are often fragile and not designed to withstand the conditions of low-resource settings. In order to design a probe, better suited to the needs of health care facilities in low-resource settings this study aimed to document the site and nature of pulse oximeter probe breakages in a range of different probe designs in a low to middle income country. A retrospective review of job cards relating to the assessment and repair of damaged or faulty pulse oximeter probes was conducted at a medical device repair company based in Cape Town, South Africa, specializing in pulse oximeter probe repairs. 1,840 job cards relating to the assessment and repair of pulse oximeter probes were reviewed. 60.2 % of probes sent for assessment were finger-clip probes. For all probes, excluding the neonatal wrap probes, the most common point of failure was the probe wiring (>50 %). The neonatal wrap most commonly failed at the strap (51.5 %). The total cost for quoting on the broken pulse oximeter probes and for the subsequent repair of devices, excluding replacement components, amounted to an estimated ZAR 738,810 (USD $98,508). Improving the probe wiring would increase the life span of pulse oximeter probes. Increasing the life span of probes will make pulse oximetry more affordable and accessible. This is of high priority in low-resource settings where frequent repair or replacement of probes is unaffordable or impossible.

The (n,p) reaction as a probe of nuclear structure

International Nuclear Information System (INIS)

Jackson, K.P.; Celler, A.

1988-08-01

An account is given of some results of studies of the (n,p) reaction on nuclear targets at TRIUMF. The (n,p) reaction, inducing spin flip transitions in isospin space, appears to exhibit a unique sensitivity to certain aspects of nuclear structure. The TRIUMF facility is the first to exploit the (n,p) reaction as a detailed probe of nuclear structure at energies above 65 MeV. In the (n,p) reaction Fermi transitions are absent, but there is a dramatic impact on Gamow-Teller and other collective transactions. Some nuclear transition matrix elements can be estimated on the basis of (n,p) measurements. Experiments have been carried out at TRIUMF on Li 6 , Fe 5 4, and Zr 9 0 targets. The calibration of the (n,p) reaction as a probe of the Gamow-Teller strength B + GT has been achieved for three targets. (L.L.) (45 refs., 10 figs.)

Exact dimension estimation of interacting qubit systems assisted by a single quantum probe

Science.gov (United States)

Sone, Akira; Cappellaro, Paola

2017-12-01

Estimating the dimension of an Hilbert space is an important component of quantum system identification. In quantum technologies, the dimension of a quantum system (or its corresponding accessible Hilbert space) is an important resource, as larger dimensions determine, e.g., the performance of quantum computation protocols or the sensitivity of quantum sensors. Despite being a critical task in quantum system identification, estimating the Hilbert space dimension is experimentally challenging. While there have been proposals for various dimension witnesses capable of putting a lower bound on the dimension from measuring collective observables that encode correlations, in many practical scenarios, especially for multiqubit systems, the experimental control might not be able to engineer the required initialization, dynamics, and observables. Here we propose a more practical strategy that relies not on directly measuring an unknown multiqubit target system, but on the indirect interaction with a local quantum probe under the experimenter's control. Assuming only that the interaction model is given and the evolution correlates all the qubits with the probe, we combine a graph-theoretical approach and realization theory to demonstrate that the system dimension can be exactly estimated from the model order of the system. We further analyze the robustness in the presence of background noise of the proposed estimation method based on realization theory, finding that despite stringent constrains on the allowed noise level, exact dimension estimation can still be achieved.

Integer Representations towards Efficient Counting in the Bit Probe Model

DEFF Research Database (Denmark)

Brodal, Gerth Stølting; Greve, Mark; Pandey, Vineet

2011-01-01

Abstract We consider the problem of representing numbers in close to optimal space and supporting increment, decrement, addition and subtraction operations efficiently. We study the problem in the bit probe model and analyse the number of bits read and written to perform the operations, both...... in the worst-case and in the average-case. A counter is space-optimal if it represents any number in the range [0,...,2 n  − 1] using exactly n bits. We provide a space-optimal counter which supports increment and decrement operations by reading at most n − 1 bits and writing at most 3 bits in the worst......-case. To the best of our knowledge, this is the first such representation which supports these operations by always reading strictly less than n bits. For redundant counters where we only need to represent numbers in the range [0,...,L] for some integer L bits, we define the efficiency...

NeuroMEMS: Neural Probe Microtechnologies

Directory of Open Access Journals (Sweden)

Sam Musallam

2008-10-01

Full Text Available Neural probe technologies have already had a significant positive effect on our understanding of the brain by revealing the functioning of networks of biological neurons. Probes are implanted in different areas of the brain to record and/or stimulate specific sites in the brain. Neural probes are currently used in many clinical settings for diagnosis of brain diseases such as seizers, epilepsy, migraine, Alzheimer’s, and dementia. We find these devices assisting paralyzed patients by allowing them to operate computers or robots using their neural activity. In recent years, probe technologies were assisted by rapid advancements in microfabrication and microelectronic technologies and thus are enabling highly functional and robust neural probes which are opening new and exciting avenues in neural sciences and brain machine interfaces. With a wide variety of probes that have been designed, fabricated, and tested to date, this review aims to provide an overview of the advances and recent progress in the microfabrication techniques of neural probes. In addition, we aim to highlight the challenges faced in developing and implementing ultralong multi-site recording probes that are needed to monitor neural activity from deeper regions in the brain. Finally, we review techniques that can improve the biocompatibility of the neural probes to minimize the immune response and encourage neural growth around the electrodes for long term implantation studies.

A statistical method for estimating wood thermal diffusivity and probe geometry using in situ heat response curves from sap flow measurements.

Science.gov (United States)

Chen, Xingyuan; Miller, Gretchen R; Rubin, Yoram; Baldocchi, Dennis D

2012-12-01

The heat pulse method is widely used to measure water flux through plants; it works by using the speed at which a heat pulse is propagated through the system to infer the velocity of water through a porous medium. No systematic, non-destructive calibration procedure exists to determine the site-specific parameters necessary for calculating sap velocity, e.g., wood thermal diffusivity and probe spacing. Such parameter calibration is crucial to obtain the correct transpiration flux density from the sap flow measurements at the plant scale and subsequently to upscale tree-level water fluxes to canopy and landscape scales. The purpose of this study is to present a statistical framework for sampling and simultaneously estimating the tree's thermal diffusivity and probe spacing from in situ heat response curves collected by the implanted probes of a heat ratio measurement device. Conditioned on the time traces of wood temperature following a heat pulse, the parameters are inferred using a Bayesian inversion technique, based on the Markov chain Monte Carlo sampling method. The primary advantage of the proposed methodology is that it does not require knowledge of probe spacing or any further intrusive sampling of sapwood. The Bayesian framework also enables direct quantification of uncertainty in estimated sap flow velocity. Experiments using synthetic data show that repeated tests using the same apparatus are essential for obtaining reliable and accurate solutions. When applied to field conditions, these tests can be obtained in different seasons and can be automated using the existing data logging system. Empirical factors are introduced to account for the influence of non-ideal probe geometry on the estimation of heat pulse velocity, and are estimated in this study as well. The proposed methodology may be tested for its applicability to realistic field conditions, with an ultimate goal of calibrating heat ratio sap flow systems in practical applications.

Unparticles: Scales and high energy probes

International Nuclear Information System (INIS)

Bander, Myron; Feng, Jonathan L.; Rajaraman, Arvind; Shirman, Yuri

2007-01-01

Unparticles from hidden conformal sectors provide qualitatively new possibilities for physics beyond the standard model. In the theoretical framework of minimal models, we clarify the relation between energy scales entering various phenomenological analyses. We show that these relations always counteract the effective field theory intuition that higher dimension operators are more highly suppressed, and that the requirement of a significant conformal window places strong constraints on possible unparticle signals. With these considerations in mind, we examine some of the most robust and sensitive probes and explore novel effects of unparticles on gauge coupling evolution and fermion production at high energy colliders. These constraints are presented both as bounds on four-fermion interaction scales and as constraints on the fundamental parameter space of minimal models

Completed Gravity Probe B Undergoes Thermal Vacuum Testing

Science.gov (United States)

2000-01-01

The Gravity Probe B (GP-B) is the relativity experiment developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. In this photograph, the completed space vehicle is undergoing thermal vacuum environment testing. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies that are already enlivening other branches of science and engineering. Launched April 20, 2004 , the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Russ Underwood, Lockheed Martin Corporation.)

Preventing probe induced topography correlated artifacts in Kelvin Probe Force Microscopy

NARCIS (Netherlands)

Polak, L.; Wijngaarden, Rinke J.

2016-01-01

Kelvin Probe Force Microscopy (KPFM) on samples with rough surface topography can be hindered by topography correlated artifacts. We show that, with the proper experimental configuration and using homogeneously metal coated probes, we are able to obtain amplitude modulation (AM) KPFM results on a

Gravity Probe B Number 4 Gyro Inspected

Science.gov (United States)

2000-01-01

The Gravity Probe B (GP-B) is the relativity experiment developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. In this photograph, Stanford engineer, Chris Gray, is inspecting the number 4 gyro under monochromatic light. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies that are already enlivening other branches of science and engineering. Launched April 20, 2004 , the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Russ Leese, Stanford University.)

Current-Voltage and Floating-Potential characteristics of cylindrical emissive probes from a full-kinetic model based on the orbital motion theory

Science.gov (United States)

Chen, Xin; Sánchez-Arriaga, Gonzalo

2018-02-01

To model the sheath structure around an emissive probe with cylindrical geometry, the Orbital-Motion theory takes advantage of three conserved quantities (distribution function, transverse energy, and angular momentum) to transform the stationary Vlasov-Poisson system into a single integro-differential equation. For a stationary collisionless unmagnetized plasma, this equation describes self-consistently the probe characteristics. By solving such an equation numerically, parametric analyses for the current-voltage (IV) and floating-potential (FP) characteristics can be performed, which show that: (a) for strong emission, the space-charge effects increase with probe radius; (b) the probe can float at a positive potential relative to the plasma; (c) a smaller probe radius is preferred for the FP method to determine the plasma potential; (d) the work function of the emitting material and the plasma-ion properties do not influence the reliability of the floating-potential method. Analytical analysis demonstrates that the inflection point of an IV curve for non-emitting probes occurs at the plasma potential. The flat potential is not a self-consistent solution for emissive probes.

Arboreas voces solis luneque loquentes: la visita de Alejandro Magno a los árboles del sol y de la luna en las crónicas del siglo XII

Directory of Open Access Journals (Sweden)

José Miguel De Toro Vidal

2016-08-01

Full Text Available El encuentro de Alejandro Magno con los árboles parlantes del Sol y de la Luna en un bosque sagrado de la India, constituye uno de los muchos episodios maravillosos de la leyenda alejandrina difundida en la Edad Media. El objetivo del presente artículo es estudiar el momento en que los cronistas deciden incorporar este pasaje en sus obras e indagar en las causas de esta decisión. Para ello se han revisado las crónicas universales del siglo XII y principios del XIII, cotejándolas con otras obras producidas en la época. Se aprecia que tanto la Historia Scholastica de Pedro Coméstor como los mapamundis contribuyeron a la aceptación del episodio. No obstante, la inclusión del pasaje en las crónicas no obedece tanto a la afirmación del encuentro con los árboles como un hecho cierto de la historia, sino al proyecto histórico-literario previsto por el autor de cada crónica.

Eddy-current probe design

International Nuclear Information System (INIS)

Kincaid, T.G.; McCary, R.O.

1983-01-01

This paper describes theoretical and experimental work directed toward finding the optimum probe dimensions and operating frequency for eddy current detection of half-penny surface cracks in nonmagnetic conducting materials. The study applies to probes which excite an approximately uniform spatial field over the length of the crack at the surface of the material. In practical terms, this means that the probe is not smaller than the crack length in any of its critical dimensions. The optimization of a simple coil probe is first analyzed in detail. It is shown that signal-to-noise ratio and lift-off discrimination are maximized by a pancake coil with mean radius not greater than the crack length, operated at a frequency which gives a skin depth equal to the crack depth. The results obtained for the simple coil are then used as a basis for discussion of the design of coils with ferrite cores and shields, and for the design of recording head type probes

Wearable probes for service design

DEFF Research Database (Denmark)

Mullane, Aaron; Laaksolahti, Jarmo Matti; Svanæs, Dag

2014-01-01

Probes are used as a design method in user-centred design to allow end-users to inform design by collecting data from their lives. Probes are potentially useful in service innovation, but current probing methods require users to interrupt their activity and are consequently not ideal for use...... by service employees in reflecting on the delivery of a service. In this paper, we present the ‘wearable probe’, a probe concept that captures sensor data without distracting service employees. Data captured by the probe can be used by the service employees to reflect and co-reflect on the service journey......, helping to identify opportunities for service evolution and innovation....

Aspheric surface measurement using capacitive probes

Science.gov (United States)

Tao, Xin; Yuan, Daocheng; Li, Shaobo

2017-02-01

With the application of aspheres in optical fields, high precision and high efficiency aspheric surface metrology becomes a hot research topic. We describe a novel method of non-contact measurement of aspheric surface with capacitive probe. Taking an eccentric spherical surface as the object of study, the averaging effect of capacitive probe measurement and the influence of tilting the capacitive probe on the measurement results are investigated. By comparing measurement results from simultaneous measurement of the capacitive probe and contact probe of roundness instrument, this paper indicates the feasibility of using capacitive probes to test aspheric surface and proposes the compensation method of measurement error caused by averaging effect and the tilting of the capacitive probe.

Theoretical study of cylindrical energy analyzers for MeV range heavy ion beam probes

International Nuclear Information System (INIS)

Fujisawa, A.; Hamada, Y.

1993-07-01

A cylindrical energy analyzer with drift spaces is shown to have a second order focusing for beam incident angle when the deflection angle is properly chosen. The analyzer has a possibility to be applied to MeV range heavy ion beam probes, and will be also available for accurate particle energy measurements in many other fields. (author)

Surface topography acquisition method for double-sided near-right-angle structured surfaces based on dual-probe wavelength scanning interferometry.

Science.gov (United States)

Zhang, Tao; Gao, Feng; Jiang, Xiangqian

2017-10-02

This paper proposes an approach to measure double-sided near-right-angle structured surfaces based on dual-probe wavelength scanning interferometry (DPWSI). The principle and mathematical model is discussed and the measurement system is calibrated with a combination of standard step-height samples for both probes vertical calibrations and a specially designed calibration artefact for building up the space coordinate relationship of the dual-probe measurement system. The topography of the specially designed artefact is acquired by combining the measurement results with white light scanning interferometer (WLSI) and scanning electron microscope (SEM) for reference. The relative location of the two probes is then determined with 3D registration algorithm. Experimental validation of the approach is provided and the results show that the method is able to measure double-sided near-right-angle structured surfaces with nanometer vertical resolution and micrometer lateral resolution.

Space- and ground-based particle physics meet at CERN

CERN Multimedia

CERN Bulletin

2012-01-01

The fourth international conference on Particle and Fundamental Physics in Space (SpacePart12) will take place at CERN from 5 to 7 November. The conference will bring together scientists working on particle and fundamental physics in space and on ground, as well as space policy makers from around the world.   One hundred years after Victor Hess discovered cosmic rays using hot air balloons, the experimental study of particle and fundamental physics is still being pursued today with extremely sophisticated techniques: on the ground, with state-of-the-art accelerators like the LHC; and in space, with powerful observatories that probe, with amazing accuracy, the various forms of cosmic radiation, charged and neutral, which are messengers of the most extreme conditions of matter and energy. SpacePart12 will be the opportunity for participants to exchange views on the progress of space-related science and technology programmes in the field of particle and fundamental physics in space. SpacePar...

Cantilevered probe detector with piezoelectric element

Science.gov (United States)

Adams, Jesse D; Sulchek, Todd A; Feigin, Stuart C

2013-04-30

A disclosed chemical detection system for detecting a target material, such as an explosive material, can include a cantilevered probe, a probe heater coupled to the cantilevered probe, and a piezoelectric element disposed on the cantilevered probe. The piezoelectric element can be configured as a detector and/or an actuator. Detection can include, for example, detecting a movement of the cantilevered probe or a property of the cantilevered probe. The movement or a change in the property of the cantilevered probe can occur, for example, by adsorption of the target material, desorption of the target material, reaction of the target material and/or phase change of the target material. Examples of detectable movements and properties include temperature shifts, impedance shifts, and resonant frequency shifts of the cantilevered probe. The overall chemical detection system can be incorporated, for example, into a handheld explosive material detection system.

The time domain triple probe method

International Nuclear Information System (INIS)

Meier, M.A.; Hallock, G.A.; Tsui, H.Y.W.; Bengtson, R.D.

1994-01-01

A new Langmuir probe technique based on the triple probe method is being developed to provide simultaneous measurement of plasma temperature, potential, and density with the temporal and spatial resolution required to accurately characterize plasma turbulence. When the conventional triple probe method is used in an inhomogeneous plasma, local differences in the plasma measured at each probe introduce significant error in the estimation of turbulence parameters. The Time Domain Triple Probe method (TDTP) uses high speed switching of Langmuir probe potential, rather than spatially separated probes, to gather the triple probe information thus avoiding these errors. Analysis indicates that plasma response times and recent electronics technology meet the requirements to implement the TDTP method. Data reduction techniques of TDTP data are to include linear and higher order correlation analysis to estimate fluctuation induced particle and thermal transport, as well as energy relationships between temperature, density, and potential fluctuations

Transmit-receive eddy current probes

International Nuclear Information System (INIS)

Obrutsky, L.S.; Sullivan, S.P.; Cecco, V.S.

1997-01-01

In the last two decades, due to increased inspection demands, eddy current instrumentation has advanced from single-frequency, single-output instruments to multifrequency, computer-aided systems. This has significantly increased the scope of eddy current testing, but, unfortunately, it has also increased the cost and complexity of inspections. In addition, this approach has not always improved defect detectability or signal-to-noise. Most eddy current testing applications are still performed with impedance probes, which have well known limitations. However, recent research at AECL has led to improved eddy current inspections through the design and development of transmit-receive (T/R) probes. T/R eddy current probes, with laterally displaced transmit and receive coils, present a number of advantages over impedance probes. They have improved signal-to-noise ratio in the presence of variable lift-off compared to impedance probes. They have strong directional properties, permitting probe optimization for circumferential or axial crack detection, and possess good phase discrimination to surface defects. They can significantly increase the scope of eddy current testing permitting reliable detection and sizing of cracks in heat exchanger tubing as well as in welded areas of both ferritic and non-ferromagnetic components. This presentation will describe the operating principles of T/R probes with the help of computer-derived normalized voltage diagrams. We will discuss their directional properties and analyze the advantages of using single and multiple T/R probes over impedance probes for specific inspection cases. Current applications to surface and tube testing and some typical inspection results will be described. (author)

Water cooled static pressure probe

Science.gov (United States)

Lagen, Nicholas T. (Inventor); Eves, John W. (Inventor); Reece, Garland D. (Inventor); Geissinger, Steve L. (Inventor)

1991-01-01

An improved static pressure probe containing a water cooling mechanism is disclosed. This probe has a hollow interior containing a central coolant tube and multiple individual pressure measurement tubes connected to holes placed on the exterior. Coolant from the central tube symmetrically immerses the interior of the probe, allowing it to sustain high temperature (in the region of 2500 F) supersonic jet flow indefinitely, while still recording accurate pressure data. The coolant exits the probe body by way of a reservoir attached to the aft of the probe. The pressure measurement tubes are joined to a single, larger manifold in the reservoir. This manifold is attached to a pressure transducer that records the average static pressure.

Gramáticas de la memoria. Variaciones en torno a la transición española en cuatro novelas recientes (1985-2000: Luna de lobos, Beatus ille, Corazón tan blanco y La caída de Madrid

Directory of Open Access Journals (Sweden)

José Manuel López de Abiada

2014-06-01

Full Text Available Nos proponemos abordar aspectos relacionados con la memoria histórica en novelas recientes de cuatro autores españoles significativos para considerarlas y analizarlas desde criterios consustanciales a la transición española. Las obras elegidas son Luna de lobos (de Julio Llamazares, Beatus ille (de Antonio Muñoz Molina, Corazón tan blanco (de Javier Marías y La caída de Madrid (de Rafael Chirbes. No se nos escapa la ausencia de novelas de autores de la envergadura y el significado de Juan Marsé, Manuel Vázquez Montalbán, Juan Iturralde, José Luis Cebrián o Juan Eduardo Zúñiga.

Quality control devices for intraoperative gamma probes: physical, technical and radiation protection aspects

International Nuclear Information System (INIS)

Varela, C.; Diaz, M.; Salvador, F.J.; Hernandez, M.; Jimenez, P.

2008-01-01

Now a day, radio guided surgery -a novelty in Nuclear Medicine- is increasingly used. The clinical efficiency of these procedures requires the existence of well-trained professionals and implementation of quality assurance programs. It is essential for achieving the main objective, which is an effective and safe surgical procedure, a reliable performance of the detection device. Probes' parameters must remain within the acceptance limits, so they should be checked periodically. NEMA Standards Publication NU 3-2004 'Performance Measurement and Quality Control Guidelines for Non-Imaging Intraoperative Gamma Probes' recommends 13 tests; although only 3 of them -sensibility in air, visual inspection and power source check- are considered as steadiness tests. Space resolution in a scatter medium is also a test that needs to be carried out. These tests are considerably complex since open radioactive sources are used into a liquid medium in most of the procedures. The immersion of the probe and of the radioactive sources in each case represents both risks of radioactive contamination, and of damages to the equipment. On the other hand, tests in air demand a good reproducibility. Since they are recommended be carried out before any surgery procedure, they also should be easy and quick. This paper presents 3 devices with its accessories for acceptance and quality control tests of intraoperative gamma probes. They were designed and built taking into consideration important aspects of radiological protection to handle the calibration sources and probes, both in air and into a scatter medium. These devices are designed to fit any kind of probe. Regulatory bodies as part of their instrument audits can also use them. (author)

The AMEMIYA probe. Theoretical background

International Nuclear Information System (INIS)

Belitz, Hans Joahim; Althausen, Bernhard; Uehara, Kazuya; Amemiya, Hiroshi

2010-01-01

The present probe was developed in order to measure the temperature T i of positive ions in the scrape-off layer (SOL) of tokamak where T i is usually larger than the electron temperature Ti so that the presheath in front of the probe need not be considered and the ions reach the probe with the thermal velocity. The axis of the cylindrical probe is placed parallel to the magnetic field. The important parameter are L/a, the ratio of the length to the radius of the cylindrical probe and κ, the ratio of the probe radius to (π/4) 1/2 , where is the mean ion Larmor radius. The ion current densities to the side and the end surfaces are expressed by the double integral, which can give an analytical formula with respect to the value of κ. If two electrodes with different lengths are placed parallel to the magnetic field, the difference of current densities can be reduced to κ and hence to Ti. Some examples of the application of the probe to tokamaks, JFT-2M and Textor, are demonstrated. (author)

Computer modelling of eddy current probes

International Nuclear Information System (INIS)

Sullivan, S.P.

1992-01-01

Computer programs have been developed for modelling impedance and transmit-receive eddy current probes in two-dimensional axis-symmetric configurations. These programs, which are based on analytic equations, simulate bobbin probes in infinitely long tubes and surface probes on plates. They calculate probe signal due to uniform variations in conductor thickness, resistivity and permeability. These signals depend on probe design and frequency. A finite element numerical program has been procured to calculate magnetic permeability in non-linear ferromagnetic materials. Permeability values from these calculations can be incorporated into the above analytic programs to predict signals from eddy current probes with permanent magnets in ferromagnetic tubes. These programs were used to test various probe designs for new testing applications. Measurements of magnetic permeability in magnetically biased ferromagnetic materials have been performed by superimposing experimental signals, from special laboratory ET probes, on impedance plane diagrams calculated using these programs. (author). 3 refs., 2 figs

Synthesis and characterization of time-resolved fluorescence probes for evaluation of competitive binding to melanocortin receptors.

Science.gov (United States)

Alleti, Ramesh; Vagner, Josef; Dehigaspitiya, Dilani Chathurika; Moberg, Valerie E; Elshan, N G R D; Tafreshi, Narges K; Brabez, Nabila; Weber, Craig S; Lynch, Ronald M; Hruby, Victor J; Gillies, Robert J; Morse, David L; Mash, Eugene A

2013-09-01

Probes for use in time-resolved fluorescence competitive binding assays at melanocortin receptors based on the parental ligands MSH(4), MSH(7), and NDP-α-MSH were prepared by solid phase synthesis methods, purified, and characterized. The saturation binding of these probes was studied using HEK-293 cells engineered to overexpress the human melanocortin 4 receptor (hMC4R) as well as the human cholecystokinin 2 receptor (hCCK2R). The ratios of non-specific binding to total binding approached unity at high concentrations for each probe. At low probe concentrations, receptor-mediated binding and uptake was discernable, and so probe concentrations were kept as low as possible in determining Kd values. The Eu-DTPA-PEGO-MSH(4) probe exhibited low specific binding relative to non-specific binding, even at low nanomolar concentrations, and was deemed unsuitable for use in competition binding assays. The Eu-DTPA-PEGO probes based on MSH(7) and NDP-α-MSH exhibited Kd values of 27±3.9nM and 4.2±0.48nM, respectively, for binding with hMC4R. These probes were employed in competitive binding assays to characterize the interactions of hMC4R with monovalent and divalent MSH(4), MSH(7), and NDP-α-MSH constructs derived from squalene. Results from assays with both probes reflected only statistical enhancements, suggesting improper ligand spacing on the squalene scaffold for the divalent constructs. The Ki values from competitive binding assays that employed the MSH(7)-based probe were generally lower than the Ki values obtained when the probe based on NDP-α-MSH was employed, which is consistent with the greater potency of the latter probe. The probe based on MSH(7) was also competed with monovalent, divalent, and trivalent MSH(4) constructs that previously demonstrated multivalent binding in competitive binding assays against a variant of the probe based on NDP-α-MSH. Results from these assays confirm multivalent binding, but suggest a more modest increase in avidity for these

Contamination-free sounding rocket Langmuir probe

Science.gov (United States)

Amatucci, W. E.; Schuck, P. W.; Walker, D. N.; Kintner, P. M.; Powell, S.; Holback, B.; Leonhardt, D.

2001-04-01

A technique for removing surface contaminants from a sounding rocket spherical Langmuir probe is presented. Contamination layers present on probe surfaces can skew the collected data, resulting in the incorrect determination of plasma parameters. Despite following the usual probe cleaning techniques that are used prior to a launch, the probe surface can become coated with layers of adsorbed neutral gas in less than a second when exposed to atmosphere. The laboratory tests reported here show that by heating the probe from the interior using a small halogen lamp, adsorbed neutral particles can be removed from the probe surface, allowing accurate plasma parameter measurements to be made.

Feasibility study of parallel conduction cooling of NbTi magnet and sample probe in a cryogen-free magnet system

Science.gov (United States)

Catarino, I.; Soni, V.; Barreto, J.; Martins, D.; Kar, S.

2017-02-01

The conduction cooling of both a 6 T superconducting magnet along with a sample probe in a parallel configuration is addressed in this work. A Gifford-McMahon (GM) cryocooler is directly cooling the NbTi magnet, which aims to be kept at 4 K, while a gas-gap heat switch (GGHS) manages the cooling power to be diverted to the sample probe, which may be swept from 4 K up to 300 K. A first prototype of a GGHS was customized and validated for this purpose. A sample probe assembly has been designed and assembled with the existing cryogen-free magnet system. The whole test setup and components are described and the preliminary experimental results on the integration are presented and discussed. The magnet was charged up to 3 T with a 4 K sample space and up to 1 T with a sweeping sample space temperature up to 300 K while acting on the GGHS. Despite some identified thermal insulation problems that occurred during this first test, the overall results demonstrated the feasibility of the cryogen-free parallel conduction cooling on study.

Lunar dusty plasma: A result of interaction of the solar wind flux and ultraviolet radiation with the lunar surface

International Nuclear Information System (INIS)

Lisin, E A; Tarakanov, V P; Petrov, O F; Popel, S I

2015-01-01

One of the main problems of future missions to the Moon is associated with lunar dust. Solar wind flux and ultraviolet radiation interact with the lunar surface. As a result, there is a substantial surface change and a near-surface plasma sheath. Dust particles from the lunar regolith, which turned in this plasma because of any mechanical processes, can levitate above the surface, forming dust clouds. In preparing of the space experiments “Luna-Glob” and “Luna-Resource” particle-in-cell calculations of the near-surface plasma sheath parameters are carried out. Here we present some new results of particle-in-cell simulation of the plasma sheath formed near the surface of the moon as a result of interaction of the solar wind and ultraviolet radiation with the lunar surface. The conditions of charging and stable levitation of dust particles in plasma above the lunar surface are also considered. (paper)

Laser-based ultrasonics by dual-probe interferometer detection and narrow-band ultrasound generation

Science.gov (United States)

Huang, Jin

1993-01-01

Despite the advantages of laser-based ultrasonic (LBU) systems, the overall sensitivity of LBU systems needs to be improved for practical applications. Progress is reported to achieve better LBU detection accuracy and sensitivity for applications with surface waves and Lamb waves. A novel dual-probe laser interferometer has been developed to measure the same signal at two points. The dual-probe interferometer is a modification of a conventional single-probe interferometer in that the reference beam is guided to a second detecting point on the specimen surface to form a differential measurement mode, which measure the difference of the displacements at the two points. This dual-probe interferometer is particularly useful for accurate measurements of the speed and attenuation of surface waves and Lamb waves. The dual-probe interferometer has been applied to obtain accurate measurements of the surface wave speed and attenuation on surfaces of increasing surface roughness. It has also been demonstrated that with an appropriate signal processing method, namely, the power cepstrum method, the dual-probe interferometer is applicable to measure the local surface wave speed even when the probe separation is so small that the two waveforms in the interferometer output signal overlap in the time domain. Narrow-band signal generation and detection improve the sensitivity of LBU systems. It is proposed to use a diffraction grating to form an array of illuminating strips which form a source of narrowband surface and Lamb waves. The line-array of thermoelastic sources generates narrow-band signals whose frequency and bandwidth can be easily controlled. The optimum line-array parameters, such as width, spacing and the number of lines in the array have been derived theoretically and verified experimentally. Narrow-band signal generation with optimum parameters has been demonstrated. The enhanced LBU system with dual-probe detection and narrowband signal generation has been

Dynamic pressure probe response tests for robust measurements in periodic flows close to probe resonating frequency

Science.gov (United States)

Ceyhun Şahin, Fatma; Schiffmann, Jürg

2018-02-01

A single-hole probe was designed to measure steady and periodic flows with high fluctuation amplitudes and with minimal flow intrusion. Because of its high aspect ratio, estimations showed that the probe resonates at a frequency two orders of magnitude lower than the fast response sensor cut-off frequencies. The high fluctuation amplitudes cause a non-linear behavior of the probe and available models are neither adequate for a quantitative estimation of the resonating frequencies nor for predicting the system damping. Instead, a non-linear data correction procedure based on individual transfer functions defined for each harmonic contribution is introduced for pneumatic probes that allows to extend their operating range beyond the resonating frequencies and linear dynamics. This data correction procedure was assessed on a miniature single-hole probe of 0.35 mm inner diameter which was designed to measure flow speed and direction. For the reliable use of such a probe in periodic flows, its frequency response was reproduced with a siren disk, which allows exciting the probe up to 10 kHz with peak-to-peak amplitudes ranging between 20%-170% of the absolute mean pressure. The effect of the probe interior design on the phase lag and amplitude distortion in periodic flow measurements was investigated on probes with similar inner diameters and different lengths or similar aspect ratios (L/D) and different total interior volumes. The results suggest that while the tube length consistently sets the resonance frequency, the internal total volume affects the non-linear dynamic response in terms of varying gain functions. A detailed analysis of the introduced calibration methodology shows that the goodness of the reconstructed data compared to the reference data is above 75% for fundamental frequencies up to twice the probe resonance frequency. The results clearly suggest that the introduced procedure is adequate to capture non-linear pneumatic probe dynamics and to

Calibration, field-testing, and error analysis of a gamma-ray probe for in situ measurement of dry bulk density

International Nuclear Information System (INIS)

Bertuzzi, P.; Bruckler, L.; Gabilly, Y.; Gaudu, J.C.

1987-01-01

This paper describes a new gamma-ray probe for measuring dry bulk density in the field. This equipment can be used with three different tube spacings (15, 20 and 30 cm). Calibration procedures and local error analyses are proposed for two cases: (1) for the case where the access tubes are parallel, calibration equations are given for three tube spacings. The linear correlation coefficient obtained in the laboratory is satisfactory (0.999), and a local error analysis shows that the standard deviation in the measured dry bulk density is small (+/- 0.02 g/cm 3 ); (2) when the access tubes are not parallel, a new calibration procedure is presented that accounts for and corrects measurement bias due to the deviating probe spacing. The standard deviation associated with the measured dry bulk density is greater (+/- 0.05 g/cm 3 ), but the measurements themselves are regarded as unbiased. After comparisons of core samplings and gamma-ray probe measurements, a field validation of the gamma-ray measurements is presented. Field validation was carried out on a variety of soils (clay, clay loam, loam, and silty clay loam), using gravimetric water contents that varied from 0.11 0.27 and dry bulk densities ranging from 1.30-1.80 g°cm -3 . Finally, an example of dry bulk density field variability is shown, and the spatial variability is analyzed in regard to the measurement errors

TOMS/Earth Probe UV Reflectivity Daily L3 Global 1x1.25 deg Lat/Lon Grid V008

Data.gov (United States)

National Aeronautics and Space Administration — This data product contains TOMS/Earth Probe UV Reflectivity Daily L3 Global 1x1.25 deg Lat/Lon Grid Version 8 data in ASCII format. (The shortname for this Level-3...

Bottom-quark fusion processes at the LHC for probing Z' models and B -meson decay anomalies

Science.gov (United States)

Abdullah, Mohammad; Dalchenko, Mykhailo; Dutta, Bhaskar; Eusebi, Ricardo; Huang, Peisi; Kamon, Teruki; Rathjens, Denis; Thompson, Adrian

2018-04-01

We investigate models of a heavy neutral gauge boson Z' coupling mostly to third generation quarks and second generation leptons. In this scenario, bottom quarks arising from gluon splitting can fuse into Z' allowing the LHC to probe it. In the generic framework presented, anomalies in B -meson decays reported by the LHCb experiment imply a flavor-violating b s coupling of the featured Z' constraining the lowest possible production cross section. A novel approach searching for a Z'(→μ μ ) in association with at least one bottom-tagged jet can probe regions of model parameter space existing analyses are not sensitive to.

Gravity waves as a probe of the Hubble expansion rate during an electroweak scale phase transition

International Nuclear Information System (INIS)

Chung, Daniel J. H.; Zhou Peng

2010-01-01

Just as big bang nucleosynthesis allows us to probe the expansion rate when the temperature of the Universe was around 1 MeV, the measurement of gravity waves from electroweak scale first order phase transitions may allow us to probe the expansion rate when the temperature of the Universe was at the electroweak scale. We compute the simple transformation rule for the gravity wave spectrum under the scaling transformation of the Hubble expansion rate. We then apply this directly to the scenario of quintessence kination domination and show how gravity wave spectra would shift relative to Laser Interferometer Space Antenna and Big Bang Observer projected sensitivities.

Multi-point probe for testing electrical properties and a method of producing a multi-point probe

DEFF Research Database (Denmark)

2011-01-01

A multi-point probe for testing electrical properties of a number of specific locations of a test sample comprises a supporting body defining a first surface, a first multitude of conductive probe arms (101-101'''), each of the probe arms defining a proximal end and a distal end. The probe arms...... of contact with the supporting body, and a maximum thickness perpendicular to its perpendicular bisector and its line of contact with the supporting body. Each of the probe arms has a specific area or point of contact (111-111''') at its distal end for contacting a specific location among the number...... of specific locations of the test sample. At least one of the probe arms has an extension defining a pointing distal end providing its specific area or point of contact located offset relative to its perpendicular bisector....

NASA's Parker Solar Probe and Solar Orbiter Missions: Discovering the Secrets of our Star

Science.gov (United States)

Zurbuchen, T.

2017-12-01

This session will explore the importance of the Parker Solar Probe and Solar Orbiter missions to NASA Science, and the preparations for discoveries from these missions. NASA's Parker Solar Probe and Solar Orbiter Missions have complementary missions and will provide unique and unprecedented contributions to heliophysics and astrophysics overall. These inner heliospheric missions will also be part of the Heliophysics System Observatory which includes an increasing amount of innovative new technology and architectures to address science and data in an integrated fashion and advance models through assimilation and system-level tests. During this talk, we will briefly explore how NASA Heliophysics research efforts not only increase our understanding and predictive capability of space weather phenomena, but also provide key insights on fundamental processes important throughout the universe.

Solar Probe Plus: Mission design challenges and trades

Science.gov (United States)

Guo, Yanping

2010-11-01

NASA plans to launch the first mission to the Sun, named Solar Probe Plus, as early as 2015, after a comprehensive feasibility study that significantly changed the original Solar Probe mission concept. The original Solar Probe mission concept, based on a Jupiter gravity assist trajectory, was no longer feasible under the new guidelines given to the mission. A complete redesign of the mission was required, which called for developing alternative trajectories that excluded a flyby of Jupiter. Without the very powerful gravity assist from Jupiter it was extremely difficult to get to the Sun, so designing a trajectory to reach the Sun that is technically feasible under the new mission guidelines became a key enabler to this highly challenging mission. Mission design requirements and challenges unique to this mission are reviewed and discussed, including various mission scenarios and six different trajectory designs utilizing various planetary gravity assists that were considered. The V 5GA trajectory design using five Venus gravity assists achieves a perihelion of 11.8 solar radii ( RS) in 3.3 years without any deep space maneuver (DSM). The V 7GA trajectory design reaches a perihelion of 9.5 RS using seven Venus gravity assists in 6.39 years without any DSM. With nine Venus gravity assists, the V 9GA trajectory design shows a solar orbit at inclination as high as 37.9° from the ecliptic plane can be achieved with the time of flight of 5.8 years. Using combined Earth and Venus gravity assists, as close as 9 RS from the Sun can be achieved in less than 10 years of flight time at moderate launch C3. Ultimately the V 7GA trajectory was chosen as the new baseline mission trajectory. Its design allowing for science investigation right after launch and continuing for nearly 7 years is unprecedented for interplanetary missions. The redesigned Solar Probe Plus mission is not only feasible under the new guidelines but also significantly outperforms the original mission concept

Biodistance analysis of the Moche sacrificial victims from Huaca de la Luna plaza 3C: Matrix method test of their origins.

Science.gov (United States)

Sutter, Richard C; Verano, John W

2007-02-01

The purpose of this study is to test two competing models regarding the origins of Early Intermediate Period (AD 200-750) sacrificial victims from the Huacas de Moche site using the matrix correlation method. The first model posits the sacrificial victims represent local elites who lost competitions in ritual battles with one another, while the other model suggests the victims were nonlocal warriors captured during warfare with nearby polities. We estimate biodistances for sacrificial victims from Huaca de la Luna Plaza 3C (AD 300-550) with eight previously reported samples from the north coast of Peru using both the mean measure of divergence (MMD) and Mahalanobis' distance (d2). Hypothetical matrices are developed based upon the assumptions of each of the two competing models regarding the origins of Moche sacrificial victims. When the MMD matrix is compared to the two hypothetical matrices using a partial-Mantel test (Smouse et al.: Syst Zool 35 (1986) 627-632), the ritual combat model (i.e. local origins) has a low and nonsignificant correlation (r = 0.134, P = 0.163), while the nonlocal origins model is highly correlated and significant (r = 0.688, P = 0.001). Comparisons of the d2 results and the two hypothetical matrices also produced low and nonsignificant correlation for the ritual combat model (r = 0.210, P = 0.212), while producing a higher and statistically significant result with the nonlocal origins model (r = 0.676, P = 0.002). We suggest that the Moche sacrificial victims represent nonlocal warriors captured in territorial combat with nearby competing polities. Copyright 2006 Wiley-Liss, Inc.

Probing the Locality of Excited States with Linear Algebra.

Science.gov (United States)

Etienne, Thibaud

2015-04-14

This article reports a novel theoretical approach related to the analysis of molecular excited states. The strategy introduced here involves gathering two pieces of physical information, coming from Hilbert and direct space operations, into a general, unique quantum mechanical descriptor of electronic transitions' locality. Moreover, the projection of Hilbert and direct space-derived indices in an Argand plane delivers a straightforward way to visually probe the ability of a dye to undergo a long- or short-range charge-transfer. This information can be applied, for instance, to the analysis of the electronic response of families of dyes to light absorption by unveiling the trend of a given push-pull chromophore to increase the electronic cloud polarization magnitude of its main transition with respect to the size extension of its conjugated spacer. We finally demonstrate that all the quantities reported in this article can be reliably approximated by a linear algebraic derivation, based on the contraction of detachment/attachment density matrices from canonical to atomic space. This alternative derivation has the remarkable advantage of a very low computational cost with respect to the previously used numerical integrations, making fast and accurate characterization of large molecular systems' excited states easily affordable.

Human MLPA Probe Design (H-MAPD: a probe design tool for both electrophoresis-based and bead-coupled human multiplex ligation-dependent probe amplification assays

Directory of Open Access Journals (Sweden)

Hatchwell Eli

2008-09-01

Full Text Available Abstract Background Multiplex ligation-dependent probe amplification (MLPA is an efficient and reliable technique for gene dosage analysis. Currently MLPA can be conducted on two platforms: traditional electrophoresis-based, and FlexMAP bead-coupled. Since its introduction in 2002, MLPA has been rapidly adopted in both clinical and research situations. However, MLPA probe design is a time consuming process requiring many steps that address multiple criteria. There exist only one or two commercial software packages for traditional electrophoresis-based MLPA probe design. To our knowledge, no software is yet available that performs bead-coupled MLPA probe design. Results We have developed H-MAPD, a web-based tool that automates the generation and selection of probes for human genomic MLPA. The software performs physical-chemical property tests using UNAFold software, and uniqueness tests using the UCSC genome browser. H-MAPD supports both traditional electrophoresis-based assays, as well as FlexMAP bead-coupled MLPA. Conclusion H-MAPD greatly reduces the efforts for human genomic MLPA probe design. The software is written in Perl-CGI, hosted on a Linux server, and is freely available to non-commercial users.

Mobile Probes in Mobile Learning

DEFF Research Database (Denmark)

Ørngreen, Rikke; Blomhøj, Ulla; Duvaa, Uffe

In this paper experiences from using mobile probes in educational design of a mobile learning application is presented. The probing process stems from the cultural probe method, and was influenced by qualitative interview and inquiry approaches. In the project, the mobile phone was not only acting...... as an agent for acquiring empirical data (as the situation in hitherto mobile probe settings) but was also the technological medium for which data should say something about (mobile learning). Consequently, not only the content of the data but also the ways in which data was delivered and handled, provided...... a valuable dimension for investigating mobile use. The data was collected at the same time as design activities took place and the collective data was analysed based on user experience goals and cognitive processes from interaction design and mobile learning. The mobile probe increased the knowledge base...

Adjustable Pitot Probe

Science.gov (United States)

Ashby, George C., Jr.; Robbins, W. Eugene; Horsley, Lewis A.

1991-01-01

Probe readily positionable in core of uniform flow in hypersonic wind tunnel. Formed of pair of mating cylindrical housings: transducer housing and pitot-tube housing. Pitot tube supported by adjustable wedge fairing attached to top of pitot-tube housing with semicircular foot. Probe adjusted both radially and circumferentially. In addition, pressure-sensing transducer cooled internally by water or other cooling fluid passing through annulus of cooling system.

The Antartic Ice Borehole Probe

Science.gov (United States)

Behar, A.; Carsey, F.; Lane, A.; Engelhardt, H.

2000-01-01

The Antartic Ice Borehole Probe mission is a glaciological investigation, scheduled for November 2000-2001, that will place a probe in a hot-water drilled hole in the West Antartic ice sheet. The objectives of the probe are to observe ice-bed interactions with a downward looking camera, and ice inclusions and structure, including hypothesized ice accretion, with a side-looking camera.

Gravity Probe B Detector Mount Assembly

Science.gov (United States)

2004-01-01

In this photo, the Gravity Probe B (GP-B) detector mount assembly is shown in comparison to the size of a dime. The assembly is used to detect exactly how much starlight is coming through different beams from the beam splitter in the telescope. The measurements from the tiny chips inside are what keeps GP-B aimed at the guide star. The GP-B is the relativity experiment developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies that are already enlivening other branches of science and engineering. Launched April 20, 2004 , the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Paul Ehrensberger, Stanford University.)

Radio Remote Sensing of Coronal Mass Ejections: Implications for Parker Solar Probe and Solar Orbiter

Science.gov (United States)

Kooi, J. E.; Thomas, N. C.; Guy, M. B., III; Spangler, S. R.

2017-12-01

Coronal mass ejections (CMEs) are fast-moving magnetic field structures of enhanced plasma density that play an important role in space weather. The Solar Orbiter and Parker Solar Probe will usher in a new era of in situ measurements, probing CMEs within distances of 60 and 10 solar radii, respectively. At the present, only remote-sensing techniques such as Faraday rotation can probe the plasma structure of CMEs at these distances. Faraday rotation is the change in polarization position angle of linearly polarized radiation as it propagates through a magnetized plasma (e.g. a CME) and is proportional to the path integral of the electron density and line-of-sight magnetic field. In conjunction with white-light coronagraph measurements, Faraday rotation observations have been used in recent years to determine the magnetic field strength of CMEs. We report recent results from simultaneous white-light and radio observations made of a CME in July 2015. We made radio observations using the Karl G. Jansky Very Large Array (VLA) at 1 - 2 GHz frequencies of a set of radio sources through the solar corona at heliocentric distances that ranged between 8 - 23 solar radii. These Faraday rotation observations provide a priori estimates for comparison with future in situ measurements made by the Solar Orbiter and Parker Solar Probe. Similar Faraday rotation observations made simultaneously with observations by the Solar Orbiter and Parker Solar Probe in the future could provide information about the global structure of CMEs sampled by these probes and, therefore, aid in understanding the in situ measurements.

Multimegawatt Space Reactor Safety

International Nuclear Information System (INIS)

Stanley, M.L.

1989-01-01

The Multimegawatt (MMW) Space Reactor Project supports the Strategic Defense Initiative Office requirement to provide reliable, safe, cost-effective, electrical power in the MMW range. Specifically, power may be used for neutral particle beams, free electron lasers, electromagnetic launchers, and orbital transfer vehicles. This power plant technology may also apply to the electrical power required for other uses such as deep-space probes and planetary exploration. The Multimegawatt Space Reactor Project, the Thermionic Fuel Element Verification Program, and Centaurus Program all support the Multimegawatt Space Nuclear Power Program and form an important part of the US Department of Energy's (DOE's) space and defense power systems activities. A major objective of the MMW project is the development of a reference flight system design that provides the desired levels of public safety, health protection, and special nuclear material (SNM) protection when used during its designated missions. The safety requirements for the MMW project are a hierarchy of requirements that consist of safety requirements/regulations, a safety policy, general safety criteria, safety technical specifications, safety design specifications, and the system design. This paper describes the strategy and philosophy behind the development of the safety requirements imposed upon the MMW concept developers. The safety organization, safety policy, generic safety issues, general safety criteria, and the safety technical specifications are discussed

Neutrons as a probe

International Nuclear Information System (INIS)

Iizumi, Masashi

1993-01-01

As an introduction to the symposium a brief overview will be given about the features of neutrons as a probe. First it will be pointed out that the utilization of neutrons as a probe for investigating the structural and dynamical properties of condensed matters is a benign gift eventuated from the release of atomic energy initiated by Enrico Fermi exactly half century ago. Features of neutrons as a probe are discussed in accordance with the four basic physical properties of neutrons as an elementary particle; (1) no electric charge (the interaction with matter is nuclear), (2) the mass of neutron is 1 amu, (3) spin is 1/2 and (4) neutrons have magnetic dipole moment. Overview will be given on the uniqueness of neutrons as a probe and on the variety in the way they are used in the wide research area from the pure science to the industrial applications. (author)

TOMS/Earth Probe UV Aerosol Index Monthly L3 Global 1x1.25 deg Lat/Lon Grid V008

Data.gov (United States)

National Aeronautics and Space Administration — This data product contains TOMS/Earth Probe UV Aerosol Index Monthly L3 Global 1x1.25 deg Lat/Lon Grid Version 8 data in ASCII format. (The shortname for this...

TOMS/Earth Probe Total Column Ozone Daily L3 Global 1x1.25 deg Lat/Lon Grid V008

Data.gov (United States)

National Aeronautics and Space Administration — This data product contains TOMS/Earth Probe Total Column Ozone Daily L3 Global 1x1.25 deg Lat/Lon Grid Version 8 data in ASCII format. (The shortname for this...

Density-space potential phase difference in a Kelvin--Helmholtz instability

International Nuclear Information System (INIS)

Glowienka, J.C.; Jennings, W.C.; Hickok, R.L.

1974-01-01

The low-frequency instability found in a hollow cathode discharge in helium was studied using an ion beam probe as a primary diagnostic tool. Three aspects of the instability are discussed: the location and amplitude of the oscillation and its correlation with the shape of the space potential; the phase angle between density and space potential oscillations; and the comparison of the data with three known instability models: Kelvin--Helmholtz, Rayleigh--Taylor, and drift waves--for mode identification. (U.S.)

Defects in electron irradiated vitreous SiO2 probed by positron annihiliation

International Nuclear Information System (INIS)

Uedono, Akira; Tanigawa, Shoichiro; Kawano, Takao; Itoh, Hisayoshi

1994-01-01

Defects in 3 MeV electron irradiated vitreous SiO 2 (v-SiO 2 ) were probed by the positron annihilation technique. For unirradiated v-SiO 2 specimens, almost all positrons were found to annihilate from positronium (Ps) states. This high formation probability of Ps was attributed to the trapping of positrons by open-space defects. The formation probability of Ps was decreased by the electron irradiation. The observed inhibition of the Ps formation was attributed to the trapping of positrons by point defects introduced and/or activated by the irradiation. From measurements of the lifetime distribution of Ps, it was found that, by the electron irradiation, the mean size of open-space defects was decreased and the size distribution of such defects was broadened. (Author)

Probe tests microweld strength

Science.gov (United States)

1965-01-01

Probe is developed to test strength of soldered, brazed or microwelded joints. It consists of a spring which may be adjusted to the desired test pressure by means of a threaded probe head, and an indicator lamp. Device may be used for electronic equipment testing.

Non-inductive current probe

DEFF Research Database (Denmark)

Bak, Christen Kjeldahl

1977-01-01

The current probe described is a low-cost, shunt resistor for monitoring current pulses in e.g., pulsed lasers. Rise time is......The current probe described is a low-cost, shunt resistor for monitoring current pulses in e.g., pulsed lasers. Rise time is...

Probing the core structure and evolution of red giants using gravity-dominated mixed modes observed with Kepler

NARCIS (Netherlands)

Mosser, B.; Goupil, M.J.; Belkacem, K.; Michel, E.; Stello, D.; Marques, J.P.; Elsworth, Y.; Barban, C.; Beck, P.G.; Bedding, T.R.; De Ridder, J.; García, R.A.; Hekker, S.; Kallinger, T.; Samadi, R.; Stumpe, M.C.; Barclay, T.; Burke, C.J.

2012-01-01

Context. There are now more than 22 months of long-cadence data available for thousands of red giants observed with the Kepler space mission. Consequently, we are able to clearly resolve fine details in their oscillation spectra and see many components of the mixed modes that probe the stellar core.

NASA SMART Probe: Breast Cancer Application

Science.gov (United States)

Mah, Robert W.; Norvig, Peter (Technical Monitor)

2000-01-01

There is evidence in breast cancer and other malignancies that the physiologic environment within a tumor correlates with clinical outcome. We are developing a unique percutaneous Smart Probe to be used at the time of needle biopsy of the breast. The Smart Probe will simultaneously measure multiple physiologic parameters within a breast tumor. Direct and indirect measurements of tissue oxygen levels, blood flow, pH, and tissue fluid pressure will be analyzed in real-time. These parameters will be interpreted individually and collectively by innovative neural network techniques using advanced intelligent software. The goals are 1) develop a pecutaneous Smart Probe with multiple sensor modalities and applying advanced Information Technologies to provide real time diagnostic information of the tissue at tip of the probe, 2) test the percutaneous Smart Probe in women with benign and malignant breast masses who will be undergoing surgical biopsy, 3) correlate probe sensor data with benign and malignant status of breast masses, 4) determine whether the probe can detect physiologic differences within a breast tumor, and its margins, and in adjacent normal breast tissue, 5) correlate probe sensor data with known prognostic factors for breast caner, including tumor size, tumor grade, axillary lymph node metastases, estrogen receptor and progesterone receptor status.

D-instantons and closed string tachyons in Misner space

International Nuclear Information System (INIS)

Hikida, Yasuaki; Tai, T.-S.

2006-01-01

We investigate closed string tachyon condensation in Misner space, a toy model for big bang universe. In Misner space, we are able to condense tachyonic modes of closed strings in the twisted sectors, which is supposed to remove the big bang singularity. In order to examine this, we utilize D-instanton as a probe. First, we study general properties of D-instanton by constructing boundary state and effective action. Then, resorting to these, we are able to show that tachyon condensation actually deforms the geometry such that the singularity becomes milder

Probing the recreational home –The cultural probe as a communicative tool for researcher and user

OpenAIRE

Kristav, Per

2005-01-01

How can qualitative, ethnographic and emotional aspects from probe users be mapped at the same time as they get something meaningful in return? The emphasis is here on intellectual rewards during probe work rather than future good designs that in a long term perspective can be beneficial for the probe user. This case study has elaborated the traditional use of cultural probes [1] with a selection of ten families with small children in the Öresund region. The idea was to evoke thoughts abou...

Development and testing of an ion probe for tightly-bunched particle beams

Energy Technology Data Exchange (ETDEWEB)

Ngo, M.; Pasour, J.

1996-06-01

Many high-energy physics experiments require a high-quality and well-diagnosed charged-particle beam (CPB). Precise knowledge of beam size, position, and charge distribution is often crucial to the success of the experiment. It is also important in many applications that the diagnostic used to determine the beam parameters be nonintercepting and nonperturbing. This requirement rules out many diagnostics, such as wire scanners, thin foils which produce Cerenkov or transition radiation, and even some rf cavity diagnostics. Particularly difficult to diagnose are tightly-focused (r{sub b} << 1 mm), short-duration (psec) beams, such as those in state-of-the-art or next-generation particle colliders. In this paper we describe an ion probe that is capable of penetrating the space-charge field of densely bunched CPBs without perturbation, thereby enabling the measurement of the microstructure of the bunch. This diagnostic probe uses a finely-focused stream of ions to interact with the CPB. Related techniques have been discussed in the literature. In fact, the present work evolved from an electron deflection diagnostic for CPBs that we previously described. A similar electron probe was tested even earlier at TRIUMF and in the Former Soviet Union. Electron probes have also been used to measure plasma sheaths and potentials and the neutralization of heavy ion beams. Also, Mendel has used an ion beam (22 keV He{sup +}) to probe rapidly varying fields in plasmas. The probe ions are injected across the beam tube and into the path of the high-energy CPB. The ions are deflected by the CPB, and the direction and magnitude of the deflection are directly related to the spatial and temporal charge distribution of the CPB. Easily-resolved deflections can be produced by microbunches having total charge on the order of a nCoul and pulse durations of a few psec. The deflected ions are monitored with a suitable detector, in this case a microchannel plate capable of detecting single ions.

Errors of first-order probe correction for higher-order probes in spherical near-field antenna measurements

DEFF Research Database (Denmark)

Laitinen, Tommi; Nielsen, Jeppe Majlund; Pivnenko, Sergiy

2004-01-01

An investigation is performed to study the error of the far-field pattern determined from a spherical near-field antenna measurement in the case where a first-order (mu=+-1) probe correction scheme is applied to the near-field signal measured by a higher-order probe.......An investigation is performed to study the error of the far-field pattern determined from a spherical near-field antenna measurement in the case where a first-order (mu=+-1) probe correction scheme is applied to the near-field signal measured by a higher-order probe....

Plasma density measurement with ring-type cutoff probe

International Nuclear Information System (INIS)

Kim, D.W.; You, S.J.; Na, B.K.; Kim, J.H.; Shin, Y.H.; Chang, H.Y.; Oh, W.Y.

2013-01-01

We proposed a cutoff probe with a ring-type detection tip enclosing a bar-type radiation tip. A comparative study between a proposed ring-type cutoff (RTC) probe and a conventional bar-type cutoff (BTC) probe showed that the RTC probe solved the problem of the BTC probe, the large measurement uncertainty of the electron density in a capacitively coupled plasma source. This improved characteristics of the RTC probe might have originated from the geometrical structure of the RTC probe concerning the monopole antennae radiation. This proposed cutoff probe can be expected to expand the applicable diagnostic range and to enhance the sensitivity of the cutoff probe. - Highlights: ► A cutoff probe with a ring type detection tip is proposed. ► Comparative experiment and simulation were conducted. ► The proposed probe showed a small uncertainty of measured plasma density. ► Improved characteristics might be originated from the geometrical structure

Nuclear borehole probes - theory and experiments

International Nuclear Information System (INIS)

Joergensen, J.L.; Korsbech, U.; Gynther Nielsen, K.; Oelgaard, P.L.

1985-06-01

The report gives a summary of the theoretical and expeimental work on borehole probes that has been performed since 1971 at The Department of Electrophysics, The Technical University of Denmark. The first part of the report concerns the use of a spectral natural gamma-ray probe (SNG-probe), which is used for measurements of the spectral distribution of the gamma-rays of the geological strata around a borehole. In general the spectrum is divided into three parts - the gamma-rays from potassium-40, from thorium-232 and daughters, and from uranium-238 and daughters. A set of curves showing the intensities of the gamm-radiation from K, Th, and U versus depth is called a SNG-log. If proper calibrated, the SNG-log gives the concentration of Th, U, and K in the formation surrounding the borehole. Initially the basis for an interpretation of SNG-logs is discussed. Then follows a description og some SNG-problems designed and built by The Department of Electrophysics, and a discussion of the calibration of SNG-probes. Some examples of SNG-logs are presented, and some general comments on the use of SNG-logs are given. The second part of the report concerns mainly the development of theoretical models for neutron-neutron probes, gamma-gamma probes, and pulsed-neutron probes. The purpose of this work has been to examine how well the models correlate with measured results and - where reasonable agreement is found - to use the models in studies of the factors that affect the probe responses in interpretation of experimental results and in probe design. (author)

TORE SUPRA fast reciprocating radio frequency probe

International Nuclear Information System (INIS)

Thomas, C.E. Jr.; Harris, J.H.; Haste, G.R.; Kwon, M.; Goulding, R.H.; Hoffman, D.J.; Saoutic, B.; Becoulet, A.; Fraboulet, D.; Beaumont, B.; Kuus, H.; Ladurelle, L.; Pascal, J.Y.

1995-01-01

A fast reciprocating ion cyclotron range of frequencies (ICRF) probe was installed and operated on TORE SUPRA during 1992/1993. The body of the probe was originally used on the ATF experiment at Oak Ridge National Laboratory. The probe was adapted for use on TORE SUPRA, and mounted on one of the two fast reciprocating probe mounts. The probe consists of two orthogonal single-turn wire loops, mounted so that one loop senses toroidal rf magnetic fields and the other senses poloidal rf magnetic fields. The probe began operation in June, 1993. The probe active area is approximately 5 cm long by 2 cm, and the reciprocating mount has a slow stroke (5 cm/s) of 30 cm and a fast stroke (1.5 m/s) of about 10 cm. The probe was operated at distances from the plasma edge ranging from 30 to -5 cm (i.e., inside the last closed flux surface). The probe design, electronics, calibration, data acquisition, and data processing are discussed. First data from the probe are presented as a function of ICRF power, distance from the plasma, loop orientation, and other plasma parameters. Initial data show parametric instabilities do not play an important role for ICRF in the TORE SUPRA edge and scrape-off-layer (SOL) plasmas. Additionally it is observed that the probe signal has little or no dependence on position in the SOL/plasma edge

Hyperpolarized NMR Probes for Biological Assays

Directory of Open Access Journals (Sweden)

Sebastian Meier

2014-01-01

Full Text Available During the last decade, the development of nuclear spin polarization enhanced (hyperpolarized molecular probes has opened up new opportunities for studying the inner workings of living cells in real time. The hyperpolarized probes are produced ex situ, introduced into biological systems and detected with high sensitivity and contrast against background signals using high resolution NMR spectroscopy. A variety of natural, derivatized and designed hyperpolarized probes has emerged for diverse biological studies including assays of intracellular reaction progression, pathway kinetics, probe uptake and export, pH, redox state, reactive oxygen species, ion concentrations, drug efficacy or oncogenic signaling. These probes are readily used directly under natural conditions in biofluids and are often directly developed and optimized for cellular assays, thus leaving little doubt about their specificity and utility under biologically relevant conditions. Hyperpolarized molecular probes for biological NMR spectroscopy enable the unbiased detection of complex processes by virtue of the high spectral resolution, structural specificity and quantifiability of NMR signals. Here, we provide a survey of strategies used for the selection, design and use of hyperpolarized NMR probes in biological assays, and describe current limitations and developments.

Cosmic microwave background anisotropies in multiconnected flat spaces

International Nuclear Information System (INIS)

Riazuelo, Alain; Weeks, Jeffrey; Uzan, Jean-Philippe; Lehoucq, Roland; Luminet, Jean-Pierre

2004-01-01

This article investigates the signature of the seventeen multiconnected flat spaces in cosmic microwave background (CMB) maps. For each such space it recalls a fundamental domain and a set of generating matrices, and then goes on to find an orthonormal basis for the set of eigenmodes of the Laplace operator on that space. The basis eigenmodes are expressed as linear combinations of eigenmodes of the simply connected Euclidean space. A preceding work, which provides a general method for implementing multiconnected topologies in standard CMB codes, is then applied to simulate CMB maps and angular power spectra for each space. Unlike in the 3-torus, the results in most multiconnected flat spaces depend on the location of the observer. This effect is discussed in detail. In particular, it is shown that the correlated circles on a CMB map are generically not back to back, so that negative search of back-to-back circles in the Wilkinson Microwave Anisotropy Probe data does not exclude a vast majority of flat or nearly flat topologies

Laboratory simulation of space plasma phenomena*

Science.gov (United States)

Amatucci, B.; Tejero, E. M.; Ganguli, G.; Blackwell, D.; Enloe, C. L.; Gillman, E.; Walker, D.; Gatling, G.

2017-12-01

Laboratory devices, such as the Naval Research Laboratory's Space Physics Simulation Chamber, are large-scale experiments dedicated to the creation of large-volume plasmas with parameters realistically scaled to those found in various regions of the near-Earth space plasma environment. Such devices make valuable contributions to the understanding of space plasmas by investigating phenomena under carefully controlled, reproducible conditions, allowing for the validation of theoretical models being applied to space data. By working in collaboration with in situ experimentalists to create realistic conditions scaled to those found during the observations of interest, the microphysics responsible for the observed events can be investigated in detail not possible in space. To date, numerous investigations of phenomena such as plasma waves, wave-particle interactions, and particle energization have been successfully performed in the laboratory. In addition to investigations such as plasma wave and instability studies, the laboratory devices can also make valuable contributions to the development and testing of space plasma diagnostics. One example is the plasma impedance probe developed at NRL. Originally developed as a laboratory diagnostic, the sensor has now been flown on a sounding rocket, is included on a CubeSat experiment, and will be included on the DoD Space Test Program's STP-H6 experiment on the International Space Station. In this presentation, we will describe several examples of the laboratory investigation of space plasma waves and instabilities and diagnostic development. *This work supported by the NRL Base Program.

Results of an investigation to determine local flow characteristics at the air data probe locations using an 0.030-scale model (45-0) of the space shuttle vehicle orbiter configuration 140A/B (modified) in the NASA Ames Research Center unitary plan wind tunnel (OA161, A, B, C), volume 1

Science.gov (United States)

Nichols, M. E.

1976-01-01

Results are presented of wind tunnel test 0A161 of a 0.030-scale model 45-0 of the configuration 140A/B (modified) space shuttle vehicle orbiter in the NASA Ames Research Center Unitary Plan Wind Tunnel facilities. The purpose of this test was to determine local total and static pressure environments for the air data probe locations and relative effectiveness of alternate flight-test probe configurations. Testing was done in the Mach number range from 0.30 to 3.5. Angle of attack was varied from -8 to 25 degrees while sideslip varied between -8 and 8 degrees.

Convective heat flow probe

Science.gov (United States)

Dunn, James C.; Hardee, Harry C.; Striker, Richard P.

1985-01-01

A convective heat flow probe device is provided which measures heat flow and fluid flow magnitude in the formation surrounding a borehole. The probe comprises an elongate housing adapted to be lowered down into the borehole; a plurality of heaters extending along the probe for heating the formation surrounding the borehole; a plurality of temperature sensors arranged around the periphery of the probe for measuring the temperature of the surrounding formation after heating thereof by the heater elements. The temperature sensors and heater elements are mounted in a plurality of separate heater pads which are supported by the housing and which are adapted to be radially expanded into firm engagement with the walls of the borehole. The heat supplied by the heater elements and the temperatures measured by the temperature sensors are monitored and used in providing the desired measurements. The outer peripheral surfaces of the heater pads are configured as segments of a cylinder and form a full cylinder when taken together. A plurality of temperature sensors are located on each pad so as to extend along the length and across the width thereof, with a heating element being located in each pad beneath the temperature sensors. An expansion mechanism driven by a clamping motor provides expansion and retraction of the heater pads and expandable packer-type seals are provided along the probe above and below the heater pads.

Deep-space probes

CERN Document Server

Matloff, Gregory L

2000-01-01

This excellent book by Dr Gregory Matloff could be viewed as a large multi­ disciplinary compendium of past research, current investigations and future research in astronautics. However, unlike conventional works that are usually closed, this book is an open guide in three main respects: it contains progressive exercises as the chapter and section topics evolve, it provides the reader with many updated references, and it clearly indicates projected research areas that could become current research in the near future. For a student, the included exercises could be transformed into small worksheets or notebooks featuring many modern symbolic or algebraic computation systems that run on desktop or laptop computers. Thus, rapid and progressive study is possible - a sort of learning library driven by the author and by the bibliography at the end of each chapter. More than 340 references for both professionals and students have been selected to provide the reader with a sound basis for expanding his or her knowled...

Imaging the Surfaces of Stars from Space

Science.gov (United States)

Carpenter, Kenneth; Rau, Gioia

2018-04-01

Imaging of Stellar Surfacess has been dominated to-date by ground-based observations, but space-based facilities offer tremendous potential for extending the wavelength coverage and ultimately the resolution of such efforts. We review the imaging accomplished so far from space and then talk about exciting future prospects. The earliest attempts from space indirectly produced surface maps via the Doppler Imaging Technique, using UV spectra obtained with the International Ultraviolet Explorer (IUE). Later, the first direct UV images were obtained with the Hubble Space Telescope (HST), of Mira and Betelgeuse, using the Faint Object Camera (FOC). We will show this work and then investigate prospects for IR imaging with the James Webb Space Telescope (JWST). The real potential of space-based Imaging of Stellar Surfacess, however, lies in the future, when large-baseline Fizeau interferometers, such as the UV-optical Stellar Imager (SI) Vision Mission, with a 30-element array and 500m max baseline, are flown. We describe SI and its science goals, which include 0.1 milli-arcsec spectral Imaging of Stellar Surfacess and the probing of internal structure and flows via asteroseismology.

The measurement of gas–liquid two-phase flows in a small diameter pipe using a dual-sensor multi-electrode conductance probe

International Nuclear Information System (INIS)

Zhai, Lu-Sheng; Bian, Peng; Han, Yun-Feng; Gao, Zhong-Ke; Jin, Ning-De

2016-01-01

We design a dual-sensor multi-electrode conductance probe to measure the flow parameters of gas–liquid two-phase flows in a vertical pipe with an inner diameter of 20 mm. The designed conductance probe consists of a phase volume fraction sensor (PVFS) and a cross-correlation velocity sensor (CCVS). Through inserting an insulated flow deflector in the central part of the pipe, the gas–liquid two-phase flows are forced to pass through an annual space. The multiple electrodes of the PVFS and the CCVS are flush-mounted on the inside of the pipe wall and the outside of the flow deflector, respectively. The geometry dimension of the PVFS is optimized based on the distribution characteristics of the sensor sensitivity field. In the flow loop test of vertical upward gas–liquid two-phase flows, the output signals from the dual-sensor multi-electrode conductance probe are collected by a data acquisition device from the National Instruments (NI) Corporation. The information transferring characteristics of local flow structures in the annular space are investigated using the transfer entropy theory. Additionally, the kinematic wave velocity is measured based on the drift velocity model to investigate the propagation behavior of the stable kinematic wave in the annular space. Finally, according to the motion characteristics of the gas–liquid two-phase flows, the drift velocity model based on the flow patterns is constructed to measure the individual phase flow rate with higher accuracy. (paper)

Flow of Energy through the Inner Magnetosphere during the March 17, 2015 solar storm as observed by the Van Allen Probes Radiation Belt Storm Probes Ion Composition Experiment (RBSPICE)

Science.gov (United States)

Manweiler, J. W.; Madanian, H.; Gerrard, A. J.; Patterson, J. D.; Mitchell, D. G.; Lanzerotti, L. J.

2017-12-01

On March 17, 2015, a large solar storm impacted the Earth's magnetosphere with a maximum negative Dst of -232 nT. We report on the temporal and spatial evolution of the proton energetic particle distributions in phase space during this storm, as measured by the Radiation Belt Storm Probes Ion Composition Experiment (RBSPICE) instrument on board each of the Van Allen Probes. We characterize the distribution prior to onset of the storm to provide a definition of quiet time conditions. We then show how the distribution evolves during the storm noting key changes of the distribution as a function of L and MLT and showing how the pitch angle distributions change throughout the storm. These observations displayed a number of interesting features of the storm including high beta plasma conditions and multiple injections of protons into the inner magnetosphere. We present the radial changes of the distribution at storm onset and following the evolution of the distribution during storm recovery. We compare observations of the East/West asymmetry in the proton distribution before versus after onset using both Van Allen Probes A and B spacecraft observations. Finally, we note interesting changes in the distribution showing an anomalous dropout in mid-energies of the distribution and observe an outward radial propagation of this dropout during recovery.

Probing Zeolite Crystal Architecture and Structural Imperfections using Differently Sized Fluorescent Organic Probe Molecules.

Science.gov (United States)

Hendriks, Frank C; Schmidt, Joel E; Rombouts, Jeroen A; Lammertsma, Koop; Bruijnincx, Pieter C A; Weckhuysen, Bert M

2017-05-05

A micro-spectroscopic method has been developed to probe the accessibility of zeolite crystals using a series of fluorescent 4-(4-diethylaminostyryl)-1-methylpyridinium iodide (DAMPI) probes of increasing molecular size. Staining large zeolite crystals with MFI (ZSM-5) topology and subsequent mapping of the resulting fluorescence using confocal fluorescence microscopy reveal differences in structural integrity: the 90° intergrowth sections of MFI crystals are prone to develop structural imperfections, which act as entrance routes for the probes into the zeolite crystal. Polarization-dependent measurements provide evidence for the probe molecule's alignment within the MFI zeolite pore system. The developed method was extended to BEA (Beta) crystals, showing that the previously observed hourglass pattern is a general feature of BEA crystals with this morphology. Furthermore, the probes can accurately identify at which crystal faces of BEA straight or sinusoidal pores open to the surface. The results show this method can spatially resolve the architecture-dependent internal pore structure of microporous materials, which is difficult to assess using other characterization techniques such as X-ray diffraction. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Messengers from outer space

International Nuclear Information System (INIS)

Jockers, K.

1981-01-01

In connection with the planned ESA space probe to Halley's Comet, a survey of our current knowledge of comets, and of open questions concerning them. The coma and the plasma and dust tail arise from the nucleus of the comet. Comets contain large amounts of water ice, and are surrounded by a gigantic cloud of hydrogen that is not visible to ground observation. The plasma tail arises by interaction with the solar wind. The cometary dust probably contains the most significant information on the origins of the solar system. Comets may contain prebiotic complex molecules. (orig.)

Novel Acoustic Feedback Cancellation Approaches In Hearing Aid Applications Using Probe Noise and Probe Noise Enhancement

DEFF Research Database (Denmark)

Guo, Meng; Jensen, Søren Holdt; Jensen, Jesper

2012-01-01

. In many cases, this bias problem causes the cancellation system to fail. The traditional probe noise approach, where a noise signal is added to the loudspeaker signal can, in theory, prevent the bias. However, in practice, the probe noise level must often be so high that the noise is clearly audible...... and annoying; this makes the traditional probe noise approach less useful in practical applications. In this work, we explain theoretically the decreased convergence rate when using low-level probe noise in the traditional approach, before we propose and study analytically two new probe noise approaches...... the proposed approaches much more attractive in practical applications. We demonstrate this through a simulation experiment with audio signals in a hearing aid acoustic feedback cancellation system, where the convergence rate is improved by as much as a factor of 10....

Solar flare X-radiation and energetic particles by the observation data from the Venera-13,14 space probes

International Nuclear Information System (INIS)

Belyakov, S.A.; Dajbog, E.I.; D'yachkov, A.P.

1984-01-01

The relationship between bursts of solar hard X-radiation quanta (Esub(x) > 0.055 MeV) and flares of solar cosmic rays (SCR) was considered on the basis of the data from the Venera-13, 14 space probes. The data on solar flares in Hsub(α) and thermal X-radiation range as well as radio-frequency radiation of the 3d type were used for analysis. It was established that the intensity amplitude of flare electrons (Esub(e) > 0.025 and > 0.07 MeV) and protons (Esub(p) > 1.0 MeV) correlates best with the flare importance in the thermal X-radiation range (r approximately 0.8+-0.03). The use of flare importance in thermal X-radiation range was independent measure of flare power in which SCR particles were generated enabled to construct heliolongitudinal dependences of the flare electron fluxes and to obtain the idea of the heliolongitudinal flare interval in which the effects of coronal propagation could be ignored. It is shown that the flux of the flare nonrelativistic electrons is related with the total energy release in the burst of hard X-radiation better than with the amplitude of this burst. Distributions of the solar events were studied with respect to the amplitudes of the intensity of electrons of SCR, thermal and hard X-radiation. It is shown that in the most part of the varying amplitude ranqe the distribution functions are approximated according to the power law. It is shown that the distribution function factor depends both on the parameter used for its construction and the type of events being used for analysis

The TORE SUPRA fast reciprocating RF probe

International Nuclear Information System (INIS)

Thomas, C.E. Jr.; Harris, J.H.; Haste, G.R.

1994-01-01

A fast reciprocating ICRF (Ion Cyclotron Range of Frequencies) probe was installed and operated on TORE SUPRA during 1992/1993. The body of the probe was originally used on the ATF experiment at ORNL. The probe was adapted for use on TORE SUPRA, and mounted on one of the two fast reciprocating probe mounts. The probe consists of two orthogonal single-turn wire loops, mounted so that one loop senses toroidal RF magnetic fields and the other senses poloidal RF magnetic fields. The probe began operation in June, 1993. The probe active area is approximately 5 cm long by 2 cm, and the reciprocating mount has a slow stroke (5 cm/sec) of 30 cm by 2 cm, and the reciprocating mount has a slow stroke (5 cm/sec) of 30 cm and a fast stroke (1.5 m/sec) of about 10 cm. The probe was operated at distances from the plasma edge ranging from 30 cm to -5 cm (i.e., inside the last closed flux surface). The probe design, electronics, calibration, data acquisition and data processing are discussed. First data from the probe are presented as a function of ICRF power, distance from the plasma, loop orientation, and other plasma parameters. Initial data shows parametric instabilities do not play an important role for ICRF in the TORE SUPRA edge and scrape-off-layer (SOL) plasmas. Additionally it is observed that the probe signal has little or no dependence on position in the SOL/plasma edge

Personifying space: how the public learned to care for Rosetta and Philae

Science.gov (United States)

Mignone, Claudia; Baldwin, Emily; O'Flaherty, Karen; Homfeld, Anne-Mareike; Bauer, Markus; McCaughrean, Mark

2015-04-01

One of the aspects in the communications campaign promoted by the European Space Agency (ESA) and its partner institutions throughout 2014 to raise awareness about the comet-chasing mission, Rosetta, was the development of two anthropomorphic characters depicting the Rosetta probe and the lander Philae. The two characters were featured in a series of short cartoons with a fairy-tale flair that were distributed on the internet with the aim of breaking into new audience groups. The cartoon series, named "Once upon a time", tells the adventures of Rosetta and Philae, depicted as two bold and friendly explorers on a pioneering journey across the Solar System. The episodes cover the mission milestones, from Rosetta's wake-up from deep-space hibernation to its rendezvous with the comet and Philae's landing. They were promoted through the mission's dedicated social media accounts (mainly Twitter and Facebook) and through ESA's existing social media channels as part of the broader Rosetta communications campaign. We discuss how visual storytelling was used to make the mission's scientific goals more accessible, allowing the audience to share both its excitement and risks. We describe the development of the cartoon series and the level of engagement it generated, using estimates based on the response received through our social media channels. Other tools were also used to help the public identify with the two space probes. In particular, the Twitter accounts @ESA_Rosetta (managed by ESA) and @philae2014 (managed by DLR) were run in first person, as to give the impression that the probes were writing the tweets themselves, and even interacting with one another - as is often done in the case of spacecraft Twitter accounts. All these elements added a personal feel to the comet landing, with members of the public empathising with the two space probes and caring for their well-being. This wave of interest culminated in the last few hours of Philae's operations on the comet

Forførende melankoli

DEFF Research Database (Denmark)

Bonde, Lisbeth

2016-01-01

Interview med billedkunstneren Knud Odde til udstillingen 'Luna Convento' på Sophienholm og Vendsyssel Kunstmuseum......Interview med billedkunstneren Knud Odde til udstillingen 'Luna Convento' på Sophienholm og Vendsyssel Kunstmuseum...

Dark Energy Survey Year 1 Results: Multi-Probe Methodology and Simulated Likelihood Analyses

Energy Technology Data Exchange (ETDEWEB)

Krause, E.; et al.

2017-06-28

We present the methodology for and detail the implementation of the Dark Energy Survey (DES) 3x2pt DES Year 1 (Y1) analysis, which combines configuration-space two-point statistics from three different cosmological probes: cosmic shear, galaxy-galaxy lensing, and galaxy clustering, using data from the first year of DES observations. We have developed two independent modeling pipelines and describe the code validation process. We derive expressions for analytical real-space multi-probe covariances, and describe their validation with numerical simulations. We stress-test the inference pipelines in simulated likelihood analyses that vary 6-7 cosmology parameters plus 20 nuisance parameters and precisely resemble the analysis to be presented in the DES 3x2pt analysis paper, using a variety of simulated input data vectors with varying assumptions. We find that any disagreement between pipelines leads to changes in assigned likelihood $\\Delta \\chi^2 \\le 0.045$ with respect to the statistical error of the DES Y1 data vector. We also find that angular binning and survey mask do not impact our analytic covariance at a significant level. We determine lower bounds on scales used for analysis of galaxy clustering (8 Mpc$~h^{-1}$) and galaxy-galaxy lensing (12 Mpc$~h^{-1}$) such that the impact of modeling uncertainties in the non-linear regime is well below statistical errors, and show that our analysis choices are robust against a variety of systematics. These tests demonstrate that we have a robust analysis pipeline that yields unbiased cosmological parameter inferences for the flagship 3x2pt DES Y1 analysis. We emphasize that the level of independent code development and subsequent code comparison as demonstrated in this paper is necessary to produce credible constraints from increasingly complex multi-probe analyses of current data.

Plasma Decontamination of Space Equipment for Planetary Protection

Science.gov (United States)

Thomas, Hubertus; Barczyk, Simon; Rettberg, Petra; Shimizu, Satoshi; Shimizu, Tetsuji; Klaempfl, Tobias; Morfill, Gregor; Zimmermann, Julia; Weber, Peter

The search for extraterrestrial life is one of the most challenging science topics for the next decades. Space missions, like ExoMars, plan to land and search for biological remnants on planets and moons in our nearby Solar system. Planetary protection regulations defined by COSPAR prevent that during the mission biological contamination of the bodies occur through the space probes. Therefore decontamination of the probes and more general space equipment is necessary before the launch. The up-to-date accepted decontamination procedure originate from the old NASA Viking missions and use dry heat (T>110°C for 30h) - a technology not well suited for sensitive equipment nowadays. We investigated in a study financed by the German Space Agency* cold atmospheric plasma (CAP) as an alternative for such decontamination. It is well known that CAP can kill bacteria or spores within seconds or minutes, respectively, if the plasma is in direct contact with the treated sample. This procedure might also be quite aggressive to the treated surface materials. Therefore, we developed an afterglow CAP device specially designed for the soft treatment of space equipment. Afterglow plasma produced by a SMD device in air is transported into a “larger” treatment chamber where the samples are positioned. It could be shown that samples of different bacteria and spores, the latter defined by COSPAR as a means to show the effectiveness of the decontamination process, positioned on different materials (steel, Teflon, quartz) could be effectively inactivated. The surface materials were investigated after the plasma treatment to identify etching or deposition problems. The afterglow in the treatment chamber could even overcome obstacles (tubes of different height and diameter) which simulate more complicated structures of the relevant surfaces. Up to now, CAP looks like a quite promising alternative to decontaminate space equipment and need to be studied in greater detail in the near future

Chromosome-specific DNA Repeat Probes

Energy Technology Data Exchange (ETDEWEB)

Baumgartner, Adolf; Weier, Jingly Fung; Weier, Heinz-Ulrich G.

2006-03-16

In research as well as in clinical applications, fluorescence in situ hybridization (FISH) has gained increasing popularity as a highly sensitive technique to study cytogenetic changes. Today, hundreds of commercially available DNA probes serve the basic needs of the biomedical research community. Widespread applications, however, are often limited by the lack of appropriately labeled, specific nucleic acid probes. We describe two approaches for an expeditious preparation of chromosome-specific DNAs and the subsequent probe labeling with reporter molecules of choice. The described techniques allow the preparation of highly specific DNA repeat probes suitable for enumeration of chromosomes in interphase cell nuclei or tissue sections. In addition, there is no need for chromosome enrichment by flow cytometry and sorting or molecular cloning. Our PCR-based method uses either bacterial artificial chromosomes or human genomic DNA as templates with {alpha}-satellite-specific primers. Here we demonstrate the production of fluorochrome-labeled DNA repeat probes specific for human chromosomes 17 and 18 in just a few days without the need for highly specialized equipment and without the limitation to only a few fluorochrome labels.

The Gravity Probe B Payload Hoisted by Crane

Science.gov (United States)

2001-01-01

The Gravity Probe B (GP-B) payload was hoisted by crane to the transportation truck in the W.W. Hansen Experimental Physics Laboratory in Stanford, California for shipment to the launch site at Vandenburg Air Force Base. GP-B is the relativity experiment being developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies that are already enlivening other branches of science and engineering. Launched April 20, 2004, the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University, along with major subcontractor Lockheed Martin Corporation. (Photo Credit: Stanford University)

Inspecting Friction Stir Welding using Electromagnetic Probes

Science.gov (United States)

Kinchen, David G.

2004-01-01

A report describes the use of advanced electromagnetic probes to measure the dimensions, the spatial distribution of electrical conductivity, and related other properties of friction stir welds (FSWs) between parts made of the same or different aluminum alloy(s). The probes are of the type described in in another Tech Brief. To recapitulate: A probe of this type is essentially an eddy-current probe that includes a primary (driver) winding that meanders and multiple secondary (sensing) windings that meander along the primary winding. Electrical conductivity is commonly used as a measure of heat treatment and tempering of aluminum alloys, but prior to the development of these probes, the inadequate sensitivity and limited accuracy of electrical-conductivity probes precluded such use on FSWs between different aluminum alloys, and the resolution of those probes was inadequate for measurement of FSW dimensions with positions and metallurgical properties. In contrast, the present probes afford adequate accuracy and spatial resolution for the purposes of measuring the dimensions of FSW welds and correlating spatially varying electrical conductivities with metallurgical properties, including surface defects.

Book Review: Physics of the Space Environment

Science.gov (United States)

Holman, Gordon D.

1998-01-01

Space physics, narrowly defined as the study of Earth's plasma environment, has had an identity crisis throughout its relatively brief existence as a discipline. - The limited and often serendipitous nature of the data requires the research style of an astrophysicist. However, the in situ observations and instrumentation that are central to the field are quite different from the remote observations and instrumentation of astronomy. Compared to neutral gases, the wealth of additional phenomena and the complexity associated with magnetized plasmas and their interaction leaves little in common with the atmospheric scientist. Although the phenomena studied in space physics are ultimately important to astrophysics, the intimate measurements of plasma properties provide a greater commonality with the plasma physicist. Space physics has experienced something of a renaissance in the past few years. The interdisciplinary umbrella "Solar-Terrestrial Physics" or "Sun-Earth Connection" has stimulated an increasing interaction of space physicists, solar physicists and atmospheric scientists. Spectacular images of the Sun from Yohkoh and SOHO and solar-activity-related damage to communications satellites have increased the public's awareness of and interest in "space weather". The dangers of energetic particles and currents in space to technological systems and to future space exploration have elevated space physics observations from interesting scientific measurements that can be included on a space probe to critically important measurements that must be made.

Gamma-ray imaging probes

International Nuclear Information System (INIS)

Wild, W.J.

1988-01-01

External nuclear medicine diagnostic imaging of early primary and metastatic lung cancer tumors is difficult due to the poor sensitivity and resolution of existing gamma cameras. Nonimaging counting detectors used for internal tumor detection give ambiguous results because distant background variations are difficult to discriminate from neighboring tumor sites. This suggests that an internal imaging nuclear medicine probe, particularly an esophageal probe, may be advantageously used to detect small tumors because of the ability to discriminate against background variations and the capability to get close to sites neighboring the esophagus. The design, theory of operation, preliminary bench tests, characterization of noise behavior and optimization of such an imaging probe is the central theme of this work

Photon-assisted Beam Probes for Low Temperature Plasmas and Installation of Neutral Beam Probe in Helimak

Science.gov (United States)

Garcia de Gorordo, Alvaro; Hallock, Gary A.; Kandadai, Nirmala

2008-11-01

The Heavy Ion Beam Probe (HIBP) diagnostic has successfully measured the electric potential in a number of major plasma devices in the fusion community. In contrast to a Langmuir probe, the HIBP measures the exact electric potential rather than the floating potential. It is also has the advantage of being a very nonperturbing diagnostic. We propose a new photon-assisted beam probe technique that would extend the HIBP type of diagnostics into the low temperature plasma regime. We expect this method to probe plasmas colder than 10 eV. The novelty of the proposed diagnostic is a VUV laser that ionizes the probing particle. Excimer lasers produce the pulsed VUV radiation needed. The lasers on the market don't have a short enough wavelength too ionize any ion directly and so we calculate the population density of excited states in a NLTE plasma. These new photo-ionization techniques can take an instantaneous one-dimensional potential measurement of a plasma and are ideal for nonmagnitized plasmas where continuous time resolution is not required. Also the status of the Neutral Beam Probe installation on the Helimak experiment will be presented.

Probing extra dimension through gravitational wave observations of compact binaries and their electromagnetic counterparts

Energy Technology Data Exchange (ETDEWEB)

Yu, Hao; Gu, Bao-Min; Wang, Yong-Qiang; Liu, Yu-Xiao [Institute of Theoretical Physics, Lanzhou University, Lanzhou 730000 (China); Huang, Fa Peng [Theoretical Physics Division, Institute of High Energy Physics, Chinese Academy of Sciences, P.O. Box 918-4, Beijing 100049 (China); Meng, Xin-He, E-mail: yuh13@lzu.edu.cn, E-mail: gubm15@lzu.edu.cn, E-mail: huangfp@ihep.ac.cn, E-mail: yqwang@lzu.edu.cn, E-mail: xhm@nankai.edu.cn, E-mail: liuyx@lzu.edu.cn [School of Physics, Nankai University, Tianjin 300071 (China)

2017-02-01

The future gravitational wave (GW) observations of compact binaries and their possible electromagnetic counterparts may be used to probe the nature of the extra dimension. It is widely accepted that gravitons and photons are the only two completely confirmed objects that can travel along null geodesics in our four-dimensional space-time. However, if there exist extra dimensions and only GWs can propagate freely in the bulk, the causal propagations of GWs and electromagnetic waves (EMWs) are in general different. In this paper, we study null geodesics of GWs and EMWs in a five-dimensional anti-de Sitter space-time in the presence of the curvature of the universe. We show that for general cases the horizon radius of GW is longer than EMW within equal time. Taking the GW150914 event detected by the Advanced Laser Interferometer Gravitational-Wave Observatory and the X-ray event detected by the Fermi Gamma-ray Burst Monitor as an example, we study how the curvature k and the constant curvature radius l affect the horizon radii of GW and EMW in the de Sitter and Einstein-de Sitter models of the universe. This provides an alternative method for probing extra dimension through future GW observations of compact binaries and their electromagnetic counterparts.

Pneumatic probe with laser interferometer

International Nuclear Information System (INIS)

Wilkens, P.H.

1978-01-01

Improvements to upgrade the accuracy of Rotacon probes by a complete redesign of probe to include a Michelson interferometer to replace the existing long-range capacity transducer are described. This has resulted in a compact and interchangeable probe cartridge with a 3 μin. resolution and accuracy; the cartridge can be installed and replaced in the Rotacon gauge with the minimum of realignment, which should reduce our dependence on operator skill. In addition, the stylus contact force can be reduced to 750 mg for the contacting types, but an alternative feature, which we are still developing, will use a gas jet cushion in place of the stylus to provide a noncontacting version of the same basic probe cartridge. This device is very sensitive to external vibration effects because it is virtually frictionless

Homogeneous versus heterogeneous probes for microbial ecological microarrays.

Science.gov (United States)

Bae, Jin-Woo; Park, Yong-Ha

2006-07-01

Microbial ecological microarrays have been developed for investigating the composition and functions of microorganism communities in environmental niches. These arrays include microbial identification microarrays, which use oligonucleotides, gene fragments or microbial genomes as probes. In this article, the advantages and disadvantages of each type of probe are reviewed. Oligonucleotide probes are currently useful for probing uncultivated bacteria that are not amenable to gene fragment probing, whereas the functional gene fragments amplified randomly from microbial genomes require phylogenetic and hierarchical categorization before use as microbial identification probes, despite their high resolution for both specificity and sensitivity. Until more bacteria are sequenced and gene fragment probes are thoroughly validated, heterogeneous bacterial genome probes will provide a simple, sensitive and quantitative tool for exploring the ecosystem structure.

Zero voltage mass spectrometry probes and systems

Science.gov (United States)

Cooks, Robert Graham; Wleklinski, Michael Stanley; Bag, Soumabha; Li, Yafeng

2017-10-10

The invention generally relates to zero volt mass spectrometry probes and systems. In certain embodiments, the invention provides a system including a mass spectrometry probe including a porous material, and a mass spectrometer (bench-top or miniature mass spectrometer). The system operates without an application of voltage to the probe. In certain embodiments, the probe is oriented such that a distal end faces an inlet of the mass spectrometer. In other embodiments, the distal end of the probe is 5 mm or less from an inlet of the mass spectrometer.

A Survey of the Rapidly Emerging Field of Nanotechnology: Potential Applications for Scientific Instruments and Technologies for Atmospheric Entry Probes

Science.gov (United States)

Meyyappan, M.; Arnold, J. O.

2005-01-01

The field of Nanotechnology is well funded worldwide and innovations applicable to Solar System Exploration are emerging much more rapidly than thought possible just a few years ago. This presentation will survey recent innovations from nanotechnololgy with a focus on novel applications to atmospheric entry science and probe technology, in a fashion similar to that presented by Arnold and Venkatapathy at the previous workshop forum at Lisbon Portugal, October 6-9, 2003. Nanotechnology is a rapidly emerging field that builds systems, devices and materials from the bottom up, atom by atom, and in so doing provides them with novel and remarkable macro-scale performance. This technology has the potential to revolutionize space exploration by reducing mass and simultaneously increasing capability. Thermal, Radiation, Impact Protective Shields: Atmospheric probes and humans on long duration deep space missions involved in Solar System Exploration must safely endure 3 significant hazards: (i) atmospheric entry; (ii) radiation; and (iii) micrometeorite or debris impact. Nanostructured materials could be developed to address all three hazards with a single protective shield, which would involve much less mass than a traditional approach. The concept can be ready in time for incorporation into NASA s Crew Exploration Vehicle, and possible entry probes to fly on the Jupiter Icy Moons

Hi-tech in space - Rosetta - a space sophisticate

Science.gov (United States)

2004-02-01

The European Space Agency’s Rosetta mission will be getting under way in February 2004. The Rosetta spacecraft will be pairing up with Comet 67P/Churyumov-Gerasimenko and accompanying it on its journey, investigating the comet’s composition and the dynamic processes at work as it flies sunwards. The spacecraft will even deposit a lander on the comet. “This will be our first direct contact with the surface of a comet,” said Dr Manfred Warhaut, Operations Manager for the Rosetta mission at ESA's European Space Operations Centre (ESOC) in Darmstadt, Germany. The trip is certainly not short: Rosetta will need ten years just to reach the comet. This places extreme demands on its hardware; when the probe meets up with the comet, all instruments must be fully operational, especially since it will have been in “hibernation” for 2 and a half years of its journey. During this ‘big sleep’, all systems, scientific instruments included, are turned off. Only the on-board computer remains active. Twelve cubic metres of technical wizardry Rosetta’s hardware fits into a sort of aluminium box measuring just 12 cubic metres. The scientific payload is mounted in the upper part, while the subsystems - on-board computer, transmitter and propulsion system - are housed below. The lander is fixed to the opposite side of the probe from the steerable antenna. As the spacecraft orbits the comet, the scientific instruments will at all times be pointed towards its surface; the antenna and solar panels will point towards the Earth and Sun respectively. For trajectory and attitude control and for the major braking manœuvres, Rosetta is equipped with 24 thrusters each delivering 10 N. That corresponds to the force needed here on Earth to hold a bag containing 10 apples. Rosetta sets off with 1650 kg of propellant on board, accounting for more than half its mass at lift-off. Just 20% of total mass is available for scientific purposes. So when developing the research instruments

Primitive chain network simulations of probe rheology.

Science.gov (United States)

Masubuchi, Yuichi; Amamoto, Yoshifumi; Pandey, Ankita; Liu, Cheng-Yang

2017-09-27

Probe rheology experiments, in which the dynamics of a small amount of probe chains dissolved in immobile matrix chains is discussed, have been performed for the development of molecular theories for entangled polymer dynamics. Although probe chain dynamics in probe rheology is considered hypothetically as single chain dynamics in fixed tube-shaped confinement, it has not been fully elucidated. For instance, the end-to-end relaxation of probe chains is slower than that for monodisperse melts, unlike the conventional molecular theories. In this study, the viscoelastic and dielectric relaxations of probe chains were calculated by primitive chain network simulations. The simulations semi-quantitatively reproduced the dielectric relaxation, which reflects the effect of constraint release on the end-to-end relaxation. Fair agreement was also obtained for the viscoelastic relaxation time. However, the viscoelastic relaxation intensity was underestimated, possibly due to some flaws in the model for the inter-chain cross-correlations between probe and matrix chains.

Probing the Universe with Gravitational Waves: the Laser Interferometer Space Antenna (LISA)

NARCIS (Netherlands)

Prince, T.A.; Binetruy, P.; Centrella, J.; Finn, L.; Hogan, C.; Nelemans, G.A.; Phinney, S.

2007-01-01

- For the LISA International Science Team: LISA is a joint NASA/ESA space mission designed to measure gravitational waves in the band from 0.1 mHz to 0.1 Hz, a band that is richly populated by strong sources of gravitational waves. Signals will come from a wider range of sources: massive black holes

Designs of Langmuir probes for W7-X

International Nuclear Information System (INIS)

Laube, Ralph; Laux, Michael; Ye, Min You; Greuner, Henri; Lindig, Stefan

2011-01-01

Several designs of Langmuir probes for the stellarator Wendelstein 7-X (W7-X) are described. Different types of probes are proposed for the different divertors to be used during different operational phases of W7-X. Comb-like arrays of stiff probes, arrays of flexible probes, and fixed inlay probes are reviewed. For the initial phase of W7-X it was decided to install arrays of fixed inlay probes. Two mockups were manufactured and one of them was tested with success in the high heat flux test facility GLADIS. For long-pulse operation of W7-X different conceptual designs are proposed and are still developed further. This paper summarizes the different design constrains for the Langmuir probes in the different divertor surroundings, describes the design of the array of inlay probes for the initial phase and the result of the GLADIS test, and gives a preview of the conceptual designs of probes for the long-pulse operational phase of W7-X.

Observations of the Earth's magnetic field from the Space Station: Measurement at high and extremely low altitude using Space Station-controlled free-flyers

Science.gov (United States)

Webster, W., Jr.; Frawley, J. J.; Stefanik, M.

1984-01-01

Simulation studies established that the main (core), crustal and electrojet components of the Earth's magnetic field can be observed with greater resolution or over a longer time-base than is presently possible by using the capabilities provided by the space station. Two systems are studied. The first, a large lifetime, magnetic monitor would observe the main field and its time variation. The second, a remotely-piloted, magnetic probe would observe the crustal field at low altitude and the electrojet field in situ. The system design and the scientific performance of these systems is assessed. The advantages of the space station are reviewed.

Open heavy flavor and other hard probes in ultra-relativistic heavy-ion collisions

International Nuclear Information System (INIS)

Uphoff, Jan

2013-01-01

In this thesis hard probes are studied in the partonic transport model BAMPS (Boltzmann Approach to MultiParton Scatterings). Employing Monte Carlo techniques, this model describes the 3+1 dimensional evolution of the quark gluon plasma phase in ultra-relativistic heavy-ion collisions by propagating all particles in space and time and carrying out their collisions according to the Boltzmann equation. Since hard probes are produced in hard processes with a large momentum transfer, the value of the running coupling is small and their interactions should be describable within perturbative QCD (pQCD). This work focuses on open heavy flavor, but also addresses the suppression of light parton jets, in particular to highlight differences due to the mass. For light partons, radiative processes are the dominant contribution to their energy loss. For heavy quarks, we show that also binary interactions with a running coupling and an improved Debye screening matched to hard-thermal-loop calculations play an important role. Furthermore, the impact of the mass in radiative interactions, prominently named the dead cone effect, and the interplay with the Landau-Pomeranchuk-Migdal (LPM) effect are studied in great detail. Since the transport model BAMPS has access to all medium properties and the space time information of heavy quarks, it is the ideal tool to study the dissociation and regeneration of J/ψ mesons, which is also investigated in this thesis.

IVVS probe mechanical concept design

Energy Technology Data Exchange (ETDEWEB)

Rossi, Paolo, E-mail: paolo.rossi@enea.it; Neri, Carlo; De Collibus, Mario Ferri; Mugnaini, Giampiero; Pollastrone, Fabio; Crescenzi, Fabio

2015-10-15

Highlights: • ENEA designed, developed and tested a laser based In Vessel Viewing System (IVVS). • IVVS mechanical design has been revised from 2011 to 2013 to meet ITER requirements. • Main improvements are piezoceramic actuators and a step focus system. • Successful qualification activities validated the concept design for ITER environment. - Abstract: ENEA has been deeply involved in the design, development and testing of a laser based In Vessel Viewing System (IVVS) required for the inspection of ITER plasma-facing components. The IVVS probe shall be deployed into the vacuum vessel, providing high resolution images and metrology measurements to detect damages and possible erosion. ENEA already designed and manufactured an IVVS probe prototype based on a rad-hard concept and driven by commercial micro-step motors, which demonstrated satisfying viewing and metrology performances at room conditions. The probe sends a laser beam through a reflective rotating prism. By rotating the axes of the prism, the probe can scan all the environment points except those present in a shadow cone and the backscattered light signal is then processed to measure the intensity level (viewing) and the distance from the probe (metrology). During the last years, in order to meet all the ITER environmental conditions, such as high vacuum, gamma radiation lifetime dose up to 5 MGy, cumulative neutron fluence of about 2.3 × 10{sup 17} n/cm{sup 2}, temperature of 120 °C and magnetic field of 8 T, the probe mechanical design was significantly revised introducing a new actuating system based on piezo-ceramic actuators and improved with a new step focus system. The optical and mechanical schemes have been then modified and refined to meet also the geometrical constraints. The paper describes the mechanical concept design solutions adopted in order to fulfill IVVS probe functional performance requirements considering ITER working environment and geometrical constraints.

Varalica uzvraća pogled: rekonceptualizacija drugog u djelima suvremenog indijanskog umjetnika Jamesa Lune

Directory of Open Access Journals (Sweden)

Sanja Runtić

2013-12-01

Full Text Available The paper analyzes the use of humor in the work of Luiseno artist James Luna. Utilizing the media of performance, photography and installation, using himself as the object of representation, Luna has created a recognizable artistic style that addresses the complex issues of American Indian identity and representation. His installations The End of the Frail (1990-91 and The Artifact Piece (1987, 1990 both point at the constructed nature of Native identity. Whereas the former employs satire, self-stereotyping, parody and humor to expose and confront the colonial myths, distorted attitudes and pictographic representations of Native Americans, the latter addresses the issues of Native absence and invisibility in the dominant culture. Representing himself as an artifact to provoke laughter, shock and discomfort, in The Artifact Piece Luna clearly disclosed the relationship between Western institutions of knowledge and the culture of the spectacle. Both installations draw attention to the tie between imperialism and material forms of production and representation, indicating the still ongoing institutional investment in Native allegorization through commodification and scientific practices, the fact that even today Native American identity is compromised by the colonial discourse and its disciplinary practices and imagination. Using Bhabha’s concepts of mimicry and hybridity, Bakhtin’s theory of humor and Vizenor’s trickster holotrope, our analysis discusses the subversive potential of Luna’s auto-ethnographic project, its potential to deconstruct the meta-narratives of Otherness and colonization, and create new spaces for social dialogue and cultural survival.

A new scaling for the rotational diffusion of molecular probes in polymer solutions.

Science.gov (United States)

Qing, Jing; Chen, Anpu; Zhao, Nanrong

2017-12-13

In the present work, we propose a new scaling form for the rotational diffusion coefficient of molecular probes in semi-dilute polymer solutions, based on a theoretical study. The mean-field theory for depletion effect and semi-empirical scaling equation for the macroscopic viscosity of polymer solutions are properly incorporated to specify the space-dependent concentration and viscosity profiles in the vicinity of the probe surface. Following the scheme of classical fluid mechanics, we numerically evaluate the shear torque exerted on the probes, which then allows us to further calculate the rotational diffusion coefficient D r . Particular attention is given to the scaling behavior of the retardation factor R rot ≡ D/D r with D being the diffusion coefficient in pure solvent. We find that R rot has little relevance to the macroscopic viscosity of the polymer solution, while it can be well featured by the characteristic length scale r h /δ, i.e. the ratio between the hydrodynamic radius of the probe r h and the depletion thickness δ. Correspondingly, we obtain a novel scaling form for the rotational retardation factor, following R rot = exp[a(r h /δ) b ] with rather robust parameters of a ≃ 0.51 and b ≃ 0.56. We apply the theory to an extensive calculation for various probes in specific polymer solutions of poly(ethylene glycol) (PEG) and dextran. Our theoretical results show good agreements with the experimental data, and clearly demonstrate the validity of the new scaling form. In addition, the difference of the scaling behavior between translational and rotational diffusions is clarified, from which we conclude that the depletion effect plays a more significant role on the local rotational diffusion rather than the long-range translation diffusion.

Spatial averaging of streamwise and spanwise velocity measurements in wall-bounded turbulence using ∨- and ×-probes

International Nuclear Information System (INIS)

Philip, Jimmy; Baidya, Rio; Hutchins, Nicholas; Monty, Jason P; Marusic, Ivan

2013-01-01

The effect of finite dimensions of ∨- and ×-probes is investigated for the measurement of mean and variances of streamwise and spanwise velocities in wall-turbulence. The probes are numerically simulated using a Direct Numerical Simulation database of channel flow at a friction Reynolds number (Re τ ) of 934 by varying the probe parameters, namely, the wire-lengths (l), the angle between the wires (θ) and the spacing between the wires (Δs). A single inclined wire is first studied to isolate the effect of l and θ. Analytical expressions for the variances of the streamwise and spanwise velocities are derived by applying a linear-box-type filter to the unfiltered velocity field for both ∨- and ×-probes (at θ = 45°, and arbitrary l and Δs). A similar expression for the streamwise variance in the case of a single inclined wire (for arbitrary l and θ) is also derived. These analytical expressions, supplemented with a model for the correlation over the wire-length, compare favourably with the numerical simulation results, and more importantly explain various trends that are observed in the variances with varying parameters. Close to the wall (where the errors are generally higher) the errors in spanwise variances of the ×-probes are much lower than the ∨-probes, owing to an ‘error-cancelling’ mechanism present in ×-probes due to the effect of l and Δs, as well as due to the procedure of recovering the velocities from two wires. The errors in the streamwise variances are comparable for both ∨- and ×-probes. On the other hand, mean velocities are measured with almost no error by the ∨-probe, whereas the ×-probe induces finite errors in mean velocities due to the fact that the two wires experience different mean velocities in ×-probes unlike ∨-probes. These results are explained using the corresponding analytical results, which also show that under the effect of a linear filter, measured variances depend only on the fluctuating velocities

The JPL optical communications telescope laboratory (OCTL) test bed for the future optical Deep Space Network

Science.gov (United States)

Wilson, K. E.; Page, N.; Wu, J.; Srinivasan, M.

2003-01-01

Relative to RF, the lower power-consumption and lower mass of high bandwidth optical telecommunications make this technology extremely attractive for returning data from future NASA/JPL deep space probes.

On the truncation of the azimuthal mode spectrum of high-order probes in probe-corrected spherical near-field antenna measurements

DEFF Research Database (Denmark)

Pivnenko, Sergey; Laitinen, Tommi

2011-01-01

Azimuthal mode (m mode) truncation of a high-order probe pattern in probe-corrected spherical near-field antenna measurements is studied in this paper. The results of this paper provide rules for appropriate and sufficient m-mode truncation for non-ideal first-order probes and odd-order probes wi...

Objective, Quantitative, Data-Driven Assessment of Chemical Probes.

Science.gov (United States)

Antolin, Albert A; Tym, Joseph E; Komianou, Angeliki; Collins, Ian; Workman, Paul; Al-Lazikani, Bissan

2018-02-15

Chemical probes are essential tools for understanding biological systems and for target validation, yet selecting probes for biomedical research is rarely based on objective assessment of all potential compounds. Here, we describe the Probe Miner: Chemical Probes Objective Assessment resource, capitalizing on the plethora of public medicinal chemistry data to empower quantitative, objective, data-driven evaluation of chemical probes. We assess >1.8 million compounds for their suitability as chemical tools against 2,220 human targets and dissect the biases and limitations encountered. Probe Miner represents a valuable resource to aid the identification of potential chemical probes, particularly when used alongside expert curation. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Growth of Cosmic Structure: Probing Dark Energy Beyond Expansion

International Nuclear Information System (INIS)

Huterer, Dragan; Kirkby, David; Bean, Rachel; Connolly, Andrew; Dawson, Kyle; Dodelson, Scott; Evrard, August; Jain, Bhuvnesh; Jarvis, Michael; Linder, Eric; Mandelbaum, Rachel; May, Morgan; Raccanelli, Alvise; Reid, Beth; Rozo, Eduardo; Schmidt, Fabian; Sehgal, Neelima; Slosar, Anze; Van Engelen, Alex; Wu, Hao-Yi; Zhao, Gongbo

2014-01-01

The quantity and quality of cosmic structure observations have greatly accelerated in recent years, and further leaps forward will be facilitated by imminent projects. These will enable us to map the evolution of dark and baryonic matter density fluctuations over cosmic history. The way that these fluctuations vary over space and time is sensitive to several pieces of fundamental physics: the primordial perturbations generated by GUT-scale physics; neutrino masses and interactions; the nature of dark matter and dark energy. We focus on the last of these here: the ways that combining probes of growth with those of the cosmic expansion such as distance-redshift relations will pin down the mechanism driving the acceleration of the Universe

β-Isocyanoalanine as an IR probe: comparison of vibrational dynamics between isonitrile and nitrile-derivatized IR probes.

Science.gov (United States)

Maj, Michał; Ahn, Changwoo; Kossowska, Dorota; Park, Kwanghee; Kwak, Kyungwon; Han, Hogyu; Cho, Minhaeng

2015-05-07

An infrared (IR) probe based on isonitrile (NC)-derivatized alanine 1 was synthesized and the vibrational properties of its NC stretching mode were investigated using FTIR and femtosecond IR pump-probe spectroscopy. It is found that the NC stretching mode is very sensitive to the hydrogen-bonding ability of solvent molecules. Moreover, its transition dipole strength is larger than that of nitrile (CN) in nitrile-derivatized IR probe 2. The vibrational lifetime of the NC stretching mode is found to be 5.5 ± 0.2 ps in both D2O and DMF solvents, which is several times longer than that of the azido (N3) stretching mode in azido-derivatized IR probe 3. Altogether these properties suggest that the NC group can be a very promising sensing moiety of IR probes for studying the solvation structure and dynamics of biomolecules.

Theory of Langmuir probes in anisotropic plasmas

International Nuclear Information System (INIS)

Sudit, I.D.; Woods, R.C.

1994-01-01

A theory has been developed for electron retardation by Langmuir probes of several geometries in a general anisotropic plasma with arbitrary probe orientation and valid for any sheath thickness. Electron densities and electron velocity distribution functions (EVDFs) are obtained from the second derivative of probe I-V curves, as in Druyvesteyn's original method, which was developed for isotropic plasmas. Fedorov had extended the latter method in the context of a thin sheath approximation, to axisymmetric plasmas, in which the EVDF is expanded in a series of Legendary polynomials. In the present work an expansion in a series of spherical harmonics is employed, and the coordinate transformations are handled using the irreducible representation of the three dimensional rotation group. It is shown that the Volterra integral equations that must be solved to obtain the expansion coefficients of the EVDF from the second derivative data are no more complicated in the general case that hose for the axisymmetric plasma. Furthermore in the latter case the results can be shown to be equivalent to Fedrov's thin sheath expression. For the case of planar probes a formulation based on first derivatives of the I-V curves has been obtained. If data is obtained at enough different probe orientation of a one sided planar disc probe, any number of spherical harmonic coefficient functions may be obtained by inverting a set of linear equations and the complete EVDF deduced. For a cylindrical probe or a two-sided planar disc probe the integration of the second derivative of the probe current gives the exact electron density with any arbitrary probe orientation and any degree of plasma anisotropy

A scanning Hall probe microscope for high resolution magnetic imaging down to 300 mK

International Nuclear Information System (INIS)

Khotkevych, V. V.; Bending, S. J.; Milosevic, M. V.

2008-01-01

We present the design, construction, and performance of a low-temperature scanning Hall probe microscope with submicron lateral resolution and a large scanning range. The detachable microscope head is mounted on the cold flange of a commercial 3 He-refrigerator (Oxford Instruments, Heliox VT-50) and operates between room temperature and 300 mK. It is fitted with a three-axis slip-stick nanopositioner that enables precise in situ adjustment of the probe location within a 6x6x7 mm 3 space. The local magnetic induction at the sample surface is mapped with an easily changeable microfabricated Hall probe [typically GsAs/AlGaAs or AlGaAs/InGaAs/GaAs Hall sensors with integrated scanning tunnel microscopy (STM) tunneling tips] and can achieve minimum detectable fields ≥10 mG/Hz 1/2 . The Hall probe is brought into very close proximity to the sample surface by sensing and controlling tunnel currents at the integrated STM tip. The instrument is capable of simultaneous tunneling and Hall signal acquisition in surface-tracking mode. We illustrate the potential of the system with images of superconducting vortices at the surface of a Nb thin film down to 372 mK, and also of labyrinth magnetic-domain patterns of an yttrium iron garnet film captured at room temperature.

Molecular Imaging Probe Development using Microfluidics

Science.gov (United States)

Liu, Kan; Wang, Ming-Wei; Lin, Wei-Yu; Phung, Duy Linh; Girgis, Mark D.; Wu, Anna M.; Tomlinson, James S.; Shen, Clifton K.-F.

2012-01-01

In this manuscript, we review the latest advancement of microfluidics in molecular imaging probe development. Due to increasing needs for medical imaging, high demand for many types of molecular imaging probes will have to be met by exploiting novel chemistry/radiochemistry and engineering technologies to improve the production and development of suitable probes. The microfluidic-based probe synthesis is currently attracting a great deal of interest because of their potential to deliver many advantages over conventional systems. Numerous chemical reactions have been successfully performed in micro-reactors and the results convincingly demonstrate with great benefits to aid synthetic procedures, such as purer products, higher yields, shorter reaction times compared to the corresponding batch/macroscale reactions, and more benign reaction conditions. Several ‘proof-of-principle’ examples of molecular imaging probe syntheses using microfluidics, along with basics of device architecture and operation, and their potential limitations are discussed here. PMID:22977436

Contamination effects on fixed-bias Langmuir probes

Energy Technology Data Exchange (ETDEWEB)

Steigies, C. T. [Institut fuer Experimentelle und Angewandte Physik, Christian-Albrechts-Universitaet zu Kiel, 24098 Kiel (Germany); Barjatya, A. [Department of Physical Sciences, Embry-Riddle Aeronautical University, Daytona Beach, Florida 32114 (United States)

2012-11-15

Langmuir probes are standard instruments for plasma density measurements on many sounding rockets. These probes can be operated in swept-bias as well as in fixed-bias modes. In swept-bias Langmuir probes, contamination effects are frequently visible as a hysteresis between consecutive up and down voltage ramps. This hysteresis, if not corrected, leads to poorly determined plasma densities and temperatures. With a properly chosen sweep function, the contamination parameters can be determined from the measurements and correct plasma parameters can then be determined. In this paper, we study the contamination effects on fixed-bias Langmuir probes, where no hysteresis type effect is seen in the data. Even though the contamination is not evident from the measurements, it does affect the plasma density fluctuation spectrum as measured by the fixed-bias Langmuir probe. We model the contamination as a simple resistor-capacitor circuit between the probe surface and the plasma. We find that measurements of small scale plasma fluctuations (meter to sub-meter scale) along a rocket trajectory are not affected, but the measured amplitude of large scale plasma density variation (tens of meters or larger) is attenuated. From the model calculations, we determine amplitude and cross-over frequency of the contamination effect on fixed-bias probes for different contamination parameters. The model results also show that a fixed bias probe operating in the ion-saturation region is affected less by contamination as compared to a fixed bias probe operating in the electron saturation region.

Characteristics of short distance field of a source radiating at electronic frequencies in a ionospheric plasma. Applications to density and electron temperature measurement by mutual impedance probe

International Nuclear Information System (INIS)

Debrie, R.

1983-06-01

Realization of a new type of radio-frequency probe, the mutual-impedance probe (or the quadrupole probe) is developed. Theoretical results obtained with a cold plasma description of the ionized medium with static magnetic field. Transfer impedance between two dipoles in an homogeneous hot and isotope plasma is then calculated. In equatorial ionosphere, measurements made by the H.F. quadrupole probe, in the Veronique rocket, during the Cisaspe experiment, have been interpreted with this hot plasma theory. The influence of a plasma drift with respect to the emitter dipole is analyzed. The influence of a static magnetic field in hot and homogeneous plasma, on the frequency response curve of the mutual impedance is studied. For, in ionospheric plasmas of auroral and polar zones, the earth magnetic field is no more negligible and gives to the plasma dielectric, strongly anisotropic, properties well described by the microscopic theory in hot magnetoplasma. The space time fast evolution of characteristics of plasma encountered in space experiments has been shown up with a new method of measurement the self-oscillating quadrupole probe. The work synthesis is put in a concrete form on the polar satellite Aureol-3 the first results of which are presented. This satellite allows a precise study of ionosphere auroral zones. At last, it is shown that methods developed for electron density and temperature measurements can be transposed in low frequency. In this case, measurements with quadrupole probe allow to get the ion average mass by lower hybrid frequency excitation [fr

Experimentally probing topological order and its breakdown through modular matrices

Science.gov (United States)

Luo, Zhihuang; Li, Jun; Li, Zhaokai; Hung, Ling-Yan; Wan, Yidun; Peng, Xinhua; Du, Jiangfeng

2018-02-01

The modern concept of phases of matter has undergone tremendous developments since the first observation of topologically ordered states in fractional quantum Hall systems in the 1980s. In this paper, we explore the following question: in principle, how much detail of the physics of topological orders can be observed using state of the art technologies? We find that using surprisingly little data, namely the toric code Hamiltonian in the presence of generic disorders and detuning from its exactly solvable point, the modular matrices--characterizing anyonic statistics that are some of the most fundamental fingerprints of topological orders--can be reconstructed with very good accuracy solely by experimental means. This is an experimental realization of these fundamental signatures of a topological order, a test of their robustness against perturbations, and a proof of principle--that current technologies have attained the precision to identify phases of matter and, as such, probe an extended region of phase space around the soluble point before its breakdown. Given the special role of anyonic statistics in quantum computation, our work promises myriad applications both in probing and realistically harnessing these exotic phases of matter.

Intrauterine photoacoustic and ultrasound imaging probe

Science.gov (United States)

Miranda, Christopher; Barkley, Joel; Smith, Barbara S.

2018-04-01

Intrauterine photoacoustic and ultrasound imaging are probe-based imaging modalities with translational potential for use in detecting endometrial diseases. This deep-tissue imaging probe design allows for the retrofitting of commercially available endometrial sampling curettes. The imaging probe presented here has a 2.92-mm diameter and approximate length of 26 cm, which allows for entry into the human endometrial cavity, making it possible to use photoacoustic imaging and high-resolution ultrasound to characterize the uterus. We demonstrate the imaging probes' ability to provide structural information of an excised pig uterus using ultrasound imaging and detect photoacoustic signals at a radial depth of 1 cm.

Probing convex polygons with X-rays

International Nuclear Information System (INIS)

Edelsbrunner, H.; Skiena, S.S.

1988-01-01

An X-ray probe through a polygon measures the length of intersection between a line and the polygon. This paper considers the properties of various classes of X-ray probes, and shows how they interact to give finite strategies for completely describing convex n-gons. It is shown that (3n/2)+6 probes are sufficient to verify a specified n-gon, while for determining convex polygons (3n-1)/2 X-ray probes are necessary and 5n+O(1) sufficient, with 3n+O(1) sufficient given that a lower bound on the size of the smallest edge of P is known

Free radical scavenging properties of some wine probes

International Nuclear Information System (INIS)

Stasko, A.; Liptakova, M.; Malik, F.

1999-01-01

There are preliminary results of investigation of scavenging properties of 8 probes of Slovak wines (consisting of one reference, 3 probes of white wine and 4 probes of red wine). According to the literature so far, wine probes contain paramagnetic species (Mn 2+ , characterised with sextet spectrum, and a singlet line around g=2,00). In our probes we observed Mn 2+ signals, but no significant evidence for a single line of free radical was found. We can conclude that Mn 2+ content in the red wines is generally higher than in the white ones. Further, we investigated the scavenging activities of the probes adding solution of dinitropicryl hydrazyl (DPPH-stable radical) to them. Their ability to terminate free radicals resulted in the decrease of the final DPPH concentrations in the probes. The red wines have significantly higher capability to scavenge free radicals than the probes of white wines. (authors)

Application of the iterative probe correction technique for a high-order probe in spherical near-field antenna measurements

DEFF Research Database (Denmark)

Laitinen, Tommi; Pivnenko, Sergey; Breinbjerg, Olav

2006-01-01

An iterative probe-correction technique for spherical near-field antenna measurements is examined. This technique has previously been shown to be well-suited for non-ideal first-order probes. In this paper, its performance in the case of a high-order probe (a dual-ridged horn) is examined....

Beating of magnetic oscillations in a graphene device probed by quantum capacitance

KAUST Repository

Tahir, M.; Schwingenschlö gl, Udo

2012-01-01

We report the quantum capacitance of a monolayergraphene device in an external perpendicular magnetic field including the effects of Rashba spin-orbit interaction(SOI). The SOI mixes the spin up and spin down states of neighbouring Landau levels into two (unequally spaced) energy branches. In order to investigate the role of the SOI for the electronic transport, we study the density of states to probe the quantum capacitance of monolayergraphene.SOIeffects on the quantum magnetic oscillations (Shubnikov de Haas and de Hass-van Alphen) are deduced from the quantum capacitance.

Beating of magnetic oscillations in a graphene device probed by quantum capacitance

KAUST Repository

Tahir, M.

2012-07-05

We report the quantum capacitance of a monolayergraphene device in an external perpendicular magnetic field including the effects of Rashba spin-orbit interaction(SOI). The SOI mixes the spin up and spin down states of neighbouring Landau levels into two (unequally spaced) energy branches. In order to investigate the role of the SOI for the electronic transport, we study the density of states to probe the quantum capacitance of monolayergraphene.SOIeffects on the quantum magnetic oscillations (Shubnikov de Haas and de Hass-van Alphen) are deduced from the quantum capacitance.

Encapsulation method for atom probe tomography analysis of nanoparticles

International Nuclear Information System (INIS)

Larson, D.J.; Giddings, A.D.; Wu, Y.; Verheijen, M.A.; Prosa, T.J.; Roozeboom, F.; Rice, K.P.; Kessels, W.M.M.; Geiser, B.P.; Kelly, T.F.

2015-01-01

Open-space nanomaterials are a widespread class of technologically important materials that are generally incompatible with analysis by atom probe tomography (APT) due to issues with specimen preparation, field evaporation and data reconstruction. The feasibility of encapsulating such non-compact matter in a matrix to enable APT measurements is investigated using nanoparticles as an example. Simulations of field evaporation of a void, and the resulting artifacts in ion trajectory, underpin the requirement that no voids remain after encapsulation. The approach is demonstrated by encapsulating Pt nanoparticles in an ZnO:Al matrix created by atomic layer deposition, a growth technique which offers very high surface coverage and conformality. APT measurements of the Pt nanoparticles are correlated with transmission electron microscopy images and numerical simulations in order to evaluate the accuracy of the APT reconstruction. - Highlights: • Pt nanoparticles were analyzed using atom probe tomography and TEM. • The particles were prepared by encapsulation using atomic layer deposition. • Simulation of field evaporation near a void results in aberrations in ion trajectories. • Apparent differences between TEM and APT analyses are reconciled through simulation of field evaporation from a low-field matrix containing high-field NPs; ion trajectory aberrations are shown to lead to an apparent mixing of the matrix into the NPs.

Modeling the Insertion Mechanics of Flexible Neural Probes Coated with Sacrificial Polymers for Optimizing Probe Design

Directory of Open Access Journals (Sweden)

Sagar Singh

2016-03-01

Full Text Available Single-unit recording neural probes have significant advantages towards improving signal-to-noise ratio and specificity for signal acquisition in brain-to-computer interface devices. Long-term effectiveness is unfortunately limited by the chronic injury response, which has been linked to the mechanical mismatch between rigid probes and compliant brain tissue. Small, flexible microelectrodes may overcome this limitation, but insertion of these probes without buckling requires supporting elements such as a stiff coating with a biodegradable polymer. For these coated probes, there is a design trade-off between the potential for successful insertion into brain tissue and the degree of trauma generated by the insertion. The objective of this study was to develop and validate a finite element model (FEM to simulate insertion of coated neural probes of varying dimensions and material properties into brain tissue. Simulations were performed to predict the buckling and insertion forces during insertion of coated probes into a tissue phantom with material properties of brain. The simulations were validated with parallel experimental studies where probes were inserted into agarose tissue phantom, ex vivo chick embryonic brain tissue, and ex vivo rat brain tissue. Experiments were performed with uncoated copper wire and both uncoated and coated SU-8 photoresist and Parylene C probes. Model predictions were found to strongly agree with experimental results (<10% error. The ratio of the predicted buckling force-to-predicted insertion force, where a value greater than one would ideally be expected to result in successful insertion, was plotted against the actual success rate from experiments. A sigmoidal relationship was observed, with a ratio of 1.35 corresponding to equal probability of insertion and failure, and a ratio of 3.5 corresponding to a 100% success rate. This ratio was dubbed the “safety factor”, as it indicated the degree to which the coating

Gravity-assist engine for space propulsion

Science.gov (United States)

Bergstrom, Arne

2014-06-01

As a possible alternative to rockets, the present article describes a new type of engine for space travel, based on the gravity-assist concept for space propulsion. The new engine is to a great extent inspired by the conversion of rotational angular momentum to orbital angular momentum occurring in tidal locking between astronomical bodies. It is also greatly influenced by Minovitch's gravity-assist concept, which has revolutionized modern space technology, and without which the deep-space probes to the outer planets and beyond would not have been possible. Two of the three gravitating bodies in Minovitch's concept are in the gravity-assist engine discussed in this article replaced by an extremely massive ‘springbell' (in principle a spinning dumbbell with a powerful spring) incorporated into the spacecraft itself, and creating a three-body interaction when orbiting around a gravitating body. This makes gravity-assist propulsion possible without having to find suitably aligned astronomical bodies. Detailed numerical simulations are presented, showing how an actual spacecraft can use a ca 10-m diameter springbell engine in order to leave the earth's gravitational field and enter an escape trajectory towards interplanetary destinations.

The conductivity of Bi(111) investigated with nanoscale four point probes

DEFF Research Database (Denmark)

Wells, J.W.; Handrup, K.; Kallehauge, J.F.

2008-01-01

The room temperature conductance of Bi(111) was measured using microscopic four point probes with a contact spacing down to 500 nm. The conductance is remarkably similar to that of the bulk, indicating that surface scattering is not a major mechanism for restricting the mobility at this length...... scale. Also, the high density of electronic surface states on Bi(111) does not appear to have a major influence on the measured conductance. The lower limit for the resistivity due to electronic surface states is found to be around 5 Omega. With such a value for the surface resistivity, surface...

Dark-matter decay as a complementary probe of multicomponent dark sectors.

Science.gov (United States)

Dienes, Keith R; Kumar, Jason; Thomas, Brooks; Yaylali, David

2015-02-06

In single-component theories of dark matter, the 2→2 amplitudes for dark-matter production, annihilation, and scattering can be related to each other through various crossing symmetries. The detection techniques based on these processes are thus complementary. However, multicomponent theories exhibit an additional direction for dark-matter complementarity: the possibility of dark-matter decay from heavier to lighter components. We discuss how this new detection channel may be correlated with the others, and demonstrate that the enhanced complementarity which emerges can be an important ingredient in probing and constraining the parameter spaces of such models.

A Plasmonic Gold Nanostar Theranostic Probe for In Vivo Tumor Imaging and Photothermal Therapy

Science.gov (United States)

Liu, Yang; Ashton, Jeffrey R.; Moding, Everett J.; Yuan, Hsiangkuo; Register, Janna K.; Fales, Andrew M.; Choi, Jaeyeon; Whitley, Melodi J.; Zhao, Xiaoguang; Qi, Yi; Ma, Yan; Vaidyanathan, Ganesan; Zalutsky, Michael R.; Kirsch, David G.; Badea, Cristian T.; Vo-Dinh, Tuan

2015-01-01

Nanomedicine has attracted increasing attention in recent years, because it offers great promise to provide personalized diagnostics and therapy with improved treatment efficacy and specificity. In this study, we developed a gold nanostar (GNS) probe for multi-modality theranostics including surface-enhanced Raman scattering (SERS) detection, x-ray computed tomography (CT), two-photon luminescence (TPL) imaging, and photothermal therapy (PTT). We performed radiolabeling, as well as CT and optical imaging, to investigate the GNS probe's biodistribution and intratumoral uptake at both macroscopic and microscopic scales. We also characterized the performance of the GNS nanoprobe for in vitro photothermal heating and in vivo photothermal ablation of primary sarcomas in mice. The results showed that 30-nm GNS have higher tumor uptake, as well as deeper penetration into tumor interstitial space compared to 60-nm GNS. In addition, we found that a higher injection dose of GNS can increase the percentage of tumor uptake. We also demonstrated the GNS probe's superior photothermal conversion efficiency with a highly concentrated heating effect due to a tip-enhanced plasmonic effect. In vivo photothermal therapy with a near-infrared (NIR) laser under the maximum permissible exposure (MPE) led to ablation of aggressive tumors containing GNS, but had no effect in the absence of GNS. This multifunctional GNS probe has the potential to be used for in vivo biosensing, preoperative CT imaging, intraoperative detection with optical methods (SERS and TPL), as well as image-guided photothermal therapy. PMID:26155311

Space-Charge Experiments at the CERN Proton Synchrotron

CERN Document Server

Franchetti, Giuliano; Hofmann, I; Martini, M; Métral, E; Qiang, J; Ryne, D; Steerenberg, R; CFA Beam Dynamics Workshop “High Intensity and Brightness Hadron Beams”

2005-01-01

Benchmarking of the simulation codes used for the design of the next generation of high beam power accelerators is of paramount importance due to the very demanding requirements on the level of beam losses. This is usually accomplished by comparing simulation results against available theories, and more importantly, against experimental observations. To this aim, a number of well-defined test cases, obtained by accurate measurements made in existing machines, are of great interest. Such measurements have been made in the CERN Proton Synchrotron to probe three space-charge effects: (i) transverse emittance blow-up due to space-charge induced crossing of the integer or half-integer stop-band, (ii) space-charge and octupole driven resonance trapping, and (iii) intensity-dependent emittance transfer between the two transverse planes. The last mechanism is discussed in detail in this paper and compared to simulation predictions.

Sandwich hybridization probes for the detection of Pseudo-nitzschia (Bacillariophyceae) species: An update to existing probes and a description of new probes.

Science.gov (United States)

Bowers, Holly A; Marin, Roman; Birch, James M; Scholin, Christopher A

2017-12-01

New sandwich hybridization assay (SHA) probes for detecting Pseudo-nitzschia species (P. arenysensis, P. fraudulenta, P. hasleana, P. pungens) are presented, along with updated cross-reactivity information on historical probes (SHA and FISH; fluorescence in situ hybridization) targeting P. australis and P. multiseries. Pseudo-nitzschia species are a cosmopolitan group of diatoms that produce varying levels of domoic acid (DA), a neurotoxin that can accumulate in finfish and shellfish and transfer throughout the food web. Consumption of infected food sources can lead to illness in humans (amnesic shellfish poisoning; ASP) and marine wildlife (domoic acid poisoning; DAP). The threat of human illness, along with economic loss from fishery closures has resulted in the implementation of monitoring protocols and intensive ecological studies. SHA probes have been instrumental in some of these efforts, as the technique performs well in complex heterogeneous sample matrices and has been adapted to benchtop and deployable (Environmental Sample Processor) platforms. The expanded probe set will enhance future efforts towards understanding spatial, temporal and successional patterns in species during bloom and non-bloom periods. Copyright © 2017 Elsevier B.V. All rights reserved.

Short recovery time NMR probe

International Nuclear Information System (INIS)

Ramia, M.E.; Martin, C.A.; Jeandrevin, S.

2011-01-01

A NMR probe for low frequency and short recovery time is presented in this work. The probe contains the tuning circuit, diode expanders and quarter wavelength networks to protect the receiver from both the amplifier noise and the coil ringing following the transmitter power pulse. It also possesses a coil damper which is activated by of non active components. The probe performance shows a recovery time of about of 15μs a sensitive Q factor reduction and an increase of the signal to noise ratio of about 68% during the reception at a work frequency of 2 MHz. (author)

Study of probe-sample distance for biomedical spectra measurement

Directory of Open Access Journals (Sweden)

Li Lei

2011-11-01

Full Text Available Abstract Background Fiber-based optical spectroscopy has been widely used for biomedical applications. However, the effect of probe-sample distance on the collection efficiency has not been well investigated. Method In this paper, we presented a theoretical model to maximize the illumination and collection efficiency in designing fiber optic probes for biomedical spectra measurement. This model was in general applicable to probes with single or multiple fibers at an arbitrary incident angle. In order to demonstrate the theory, a fluorescence spectrometer was used to measure the fluorescence of human finger skin at various probe-sample distances. The fluorescence spectrum and the total fluorescence intensity were recorded. Results The theoretical results show that for single fiber probes, contact measurement always provides the best results. While for multi-fiber probes, there is an optimal probe distance. When a 400- μm excitation fiber is used to deliver the light to the skin and another six 400- μm fibers surrounding the excitation fiber are used to collect the fluorescence signal, the experimental results show that human finger skin has very strong fluorescence between 475 nm and 700 nm under 450 nm excitation. The fluorescence intensity is heavily dependent on the probe-sample distance and there is an optimal probe distance. Conclusions We investigated a number of probe-sample configurations and found that contact measurement could be the primary choice for single-fiber probes, but was very inefficient for multi-fiber probes. There was an optimal probe-sample distance for multi-fiber probes. By carefully choosing the probe-sample distance, the collection efficiency could be enhanced by 5-10 times. Our experiments demonstrated that the experimental results of the probe-sample distance dependence of collection efficiency in multi-fiber probes were in general agreement with our theory.

Why nano-oxidation with carbon nanotube probes is so stable: II. Bending behaviour of CNT probes during nano-oxidation

International Nuclear Information System (INIS)

Kuramochi, H; Tokizaki, T; Ando, K; Yokoyama, H; Dagata, J A

2007-01-01

Part I demonstrated that nano-oxidation in the dynamic-force mode was enhanced by the use of conductive carbon nanotube (CNT) probes. Fabrication of oxide nanostructures using CNT probes benefited not only from the smaller tip apex compared to conventional probes but from improved operational stability over a wide range of exposure conditions primarily due to the hydrophobic nature of the CNT. Here we investigate the bending response of CNT probes to electrostatic and meniscus forces during nano-oxidation. We conclude that bending of the CNT introduces an additional cushion in the combined cantilever-probe deflection system, thus improving overall stability of the tip-sample junction during nano-oxidation

Blinded Comparison between an In-Air Reverberation Method and an Electronic Probe Tester in the Detection of Ultrasound Probe Faults.

Science.gov (United States)

Dudley, Nicholas J; Woolley, Darren J

2017-12-01

The aim of this study was to perform a blinded trial, comparing the results of a visual inspection of the in-air reverberation pattern with the results of an electronic probe tester in detecting ultrasound probe faults. Sixty-two probes were tested. A total of 28 faults were found, 3 only by in-air reverberation assessment and 2 only by the electronic probe tester. The electronic probe tester provided additional information regarding the location of the fault in 74% of the cases in which both methods detected a fault. It is possible to detect the majority of probe faults by visual inspection and in-air reverberation assessment. The latter provides an excellent first-line test, easily performed on a daily basis by equipment users. An electronic probe tester is required if detailed evaluation of faults is necessary. Copyright © 2017 World Federation for Ultrasound in Medicine and Biology. All rights reserved.

TORE SUPRA fast reciprocating radio frequency probe (abstract)

International Nuclear Information System (INIS)

Thomas, C.E. Jr.; Harris, J.H.; Haste, G.R.; Kwon, M.; Goulding, R.H.; Hoffman, D.J.; Saoutic, B.; Becoulet, A.; Fraboulet, D.; Beaumont, B.; Kuus, H.; Ladurelle, L.; Pascal, J.Y.

1995-01-01

A fast reciprocating ion cyclotron range of frequencies (ICRF) probe was installed and operated on TORE SUPRA during 1992/1993. The body of the probe was originally used on the ATF experiment at Oak Ridge National Laboratory. The probe was adapted for use on TORE SUPRA, and mounted on one of the two fast reciprocating probe mounts. The probe consists of two orthogonal single-turn wire loops, mounted so that one loop senses toroidal rf magnetic fields and the other senses poloidal rf magnetic fields. The probe began operation in June, 1993. The probe active area is approximately 5 cm long by 2 cm, and the reciprocating mount has a slow stroke (5 cm/s) of 30 cm and a fast stroke (1.5 m/s) of about 10 cm. The probe was operated at distances from the plasma edge ranging from 30 to -5 cm (i.e., inside the last closed flux surface). The probe design, electronics, calibration, data acquisition, and data processing are discussed. First data from the probe are presented as a function of ICRF power, distance from the plasma, loop orientation, and other plasma parameters. Initial data show parametric instabilities do not play an important role for ICRF in the TORE SUPRA edge and scrape-off-layer (SOL) plasmas. Additionally it is observed that the probe signal has little or no dependence on position in the SOL/plasma edge

TOMS/Earth Probe UV-B Erythemal Local Noon Irradiance Monthly L3 Global 1x1.25 deg Lat/Lon Grid V008

Data.gov (United States)

National Aeronautics and Space Administration — This data product contains TOMS/Earth Probe UV-B Erythemal Local Noon Irradiance Monthly L3 Global 1x1.25 deg Lat/Lon Grid Version 8 data in ASCII format. (The...

Donated chemical probes for open science.

Science.gov (United States)

Müller, Susanne; Ackloo, Suzanne; Arrowsmith, Cheryl H; Bauser, Marcus; Baryza, Jeremy L; Blagg, Julian; Böttcher, Jark; Bountra, Chas; Brown, Peter J; Bunnage, Mark E; Carter, Adrian J; Damerell, David; Dötsch, Volker; Drewry, David H; Edwards, Aled M; Edwards, James; Elkins, Jon M; Fischer, Christian; Frye, Stephen V; Gollner, Andreas; Grimshaw, Charles E; IJzerman, Adriaan; Hanke, Thomas; Hartung, Ingo V; Hitchcock, Steve; Howe, Trevor; Hughes, Terry V; Laufer, Stefan; Li, Volkhart Mj; Liras, Spiros; Marsden, Brian D; Matsui, Hisanori; Mathias, John; O'Hagan, Ronan C; Owen, Dafydd R; Pande, Vineet; Rauh, Daniel; Rosenberg, Saul H; Roth, Bryan L; Schneider, Natalie S; Scholten, Cora; Singh Saikatendu, Kumar; Simeonov, Anton; Takizawa, Masayuki; Tse, Chris; Thompson, Paul R; Treiber, Daniel K; Viana, Amélia Yi; Wells, Carrow I; Willson, Timothy M; Zuercher, William J; Knapp, Stefan; Mueller-Fahrnow, Anke

2018-04-20

Potent, selective and broadly characterized small molecule modulators of protein function (chemical probes) are powerful research reagents. The pharmaceutical industry has generated many high-quality chemical probes and several of these have been made available to academia. However, probe-associated data and control compounds, such as inactive structurally related molecules and their associated data, are generally not accessible. The lack of data and guidance makes it difficult for researchers to decide which chemical tools to choose. Several pharmaceutical companies (AbbVie, Bayer, Boehringer Ingelheim, Janssen, MSD, Pfizer, and Takeda) have therefore entered into a pre-competitive collaboration to make available a large number of innovative high-quality probes, including all probe-associated data, control compounds and recommendations on use (https://openscienceprobes.sgc-frankfurt.de">https://openscienceprobes.sgc-frankfurt.dehttps://openscienceprobes.sgc-frankfurt.de/">/). Here we describe the chemical tools and target-related knowledge that have been made available, and encourage others to join the project. © 2018, Müller et al.

Atomic quantum superposition state generation via optical probing

DEFF Research Database (Denmark)

Nielsen, Anne E. B.; Poulsen, Uffe Vestergaard; Negretti, Antonio

2009-01-01

investigate cavity enhanced probing with continuous beams of both coherent and squeezed light. The stochastic master equations used in the analysis are expressed in terms of the Hamiltonian of the probed system and the interaction between the probed system and the probe field and are thus quite generally...

Defects in electron irradiated vitreous SiO[sub 2] probed by positron annihiliation

Energy Technology Data Exchange (ETDEWEB)

Uedono, Akira; Tanigawa, Shoichiro (Tsukuba Univ., Ibaraki (Japan). Inst. of Materials Science); Kawano, Takao (Tsukuba Univ., Ibaraki (Japan). Radioisotope Centre); Itoh, Hisayoshi (Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment)

1994-10-10

Defects in 3 MeV electron irradiated vitreous SiO[sub 2] (v-SiO[sub 2]) were probed by the positron annihilation technique. For unirradiated v-SiO[sub 2] specimens, almost all positrons were found to annihilate from positronium (Ps) states. This high formation probability of Ps was attributed to the trapping of positrons by open-space defects. The formation probability of Ps was decreased by the electron irradiation. The observed inhibition of the Ps formation was attributed to the trapping of positrons by point defects introduced and/or activated by the irradiation. From measurements of the lifetime distribution of Ps, it was found that, by the electron irradiation, the mean size of open-space defects was decreased and the size distribution of such defects was broadened. (Author).

Toward the Atomic-Level Mass Analysis of Biomolecules by the Scanning Atom Probe.

Science.gov (United States)

Nishikawa, Osamu; Taniguchi, Masahiro

2017-04-01

In 1994, a new type of atom probe instrument, named the scanning atom probe (SAP), was proposed. The unique feature of the SAP is the introduction of a small extraction electrode, which scans over a specimen surface and confines the high field, required for field evaporation of surface atoms in a small space, between the specimen and the electrode. Thus, the SAP does not require a sharp specimen tip. This indicates that the SAP can mass analyze the specimens which are difficult to form in a sharp tip, such as organic materials and biomolecules. Clean single wall carbon nanotubes (CNT), made by high-pressure carbon monoxide process are found to be the best substrates for biomolecules. Various amino acids and dipeptide biomolecules were successfully mass analyzed, revealing characteristic clusters formed by strongly bound atoms in the specimens. The mass analysis indicates that SAP analysis of biomolecules is not only qualitative, but also quantitative.

Holographic Reconstruction of Photoelectron Diffraction and Its Circular Dichroism for Local Structure Probing

Science.gov (United States)

Matsui, Fumihiko; Matsushita, Tomohiro; Daimon, Hiroshi

2018-06-01

The local atomic structure around a specific element atom can be recorded as a photoelectron diffraction pattern. Forward focusing peaks and diffraction rings around them indicate the directions and distances from the photoelectron emitting atom to the surrounding atoms. The state-of-the-art holography reconstruction algorithm enables us to image the local atomic arrangement around the excited atom in a real space. By using circularly polarized light as an excitation source, the angular momentum transfer from the light to the photoelectron induces parallax shifts in these diffraction patterns. As a result, stereographic images of atomic arrangements are obtained. These diffraction patterns can be used as atomic-site-resolved probes for local electronic structure investigation in combination with spectroscopy techniques. Direct three-dimensional atomic structure visualization and site-specific electronic property analysis methods are reviewed. Furthermore, circular dichroism was also found in valence photoelectron and Auger electron diffraction patterns. The investigation of these new phenomena provides hints for the development of new techniques for local structure probing.

Earthbound mission how UK funding fails to match enthusiasm for space exploration

CERN Multimedia

Nordling, L

2004-01-01

Article discussing the UK governments reluctance to fund space research projects. An example is the ESA Aurora programme which is aiming to put humans on Mars by 2030, with interim visits to the moon and a series of unmanned probes preparing the way for interplanetary manned missions (1 page)

Intrauterine photoacoustic and ultrasound imaging probe.

Science.gov (United States)

Miranda, Christopher; Barkley, Joel; Smith, Barbara

2018-04-01

Intrauterine photoacoustic and ultrasound imaging are probe-based imaging modalities with translational potential for use in detecting endometrial diseases. This deep-tissue imaging probe design allows for the retrofitting of commercially available endometrial sampling curettes. The imaging probe presented here has a 2.92-mm diameter and approximate length of 26 cm, which allows for entry into the human endometrial cavity, making it possible to use photoacoustic imaging and high-resolution ultrasound to characterize the uterus. We demonstrate the imaging probes' ability to provide structural information of an excised pig uterus using ultrasound imaging and detect photoacoustic signals at a radial depth of 1 cm. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Monitoring probe for groundwater flow

Science.gov (United States)

Looney, B.B.; Ballard, S.

1994-08-23

A monitoring probe for detecting groundwater migration is disclosed. The monitor features a cylinder made of a permeable membrane carrying an array of electrical conductivity sensors on its outer surface. The cylinder is filled with a fluid that has a conductivity different than the groundwater. The probe is placed in the ground at an area of interest to be monitored. The fluid, typically saltwater, diffuses through the permeable membrane into the groundwater. The flow of groundwater passing around the permeable membrane walls of the cylinder carries the conductive fluid in the same general direction and distorts the conductivity field measured by the sensors. The degree of distortion from top to bottom and around the probe is precisely related to the vertical and horizontal flow rates, respectively. The electrical conductivities measured by the sensors about the outer surface of the probe are analyzed to determine the rate and direction of the groundwater flow. 4 figs.

Future NASA mission applications of space nuclear power

International Nuclear Information System (INIS)

Bennett, G.L.; Mankins, J.; McConnell, D.G.; Reck, G.M.

1990-01-01

Recent studies sponsored by NASA show a continuing need for space nuclear power. A recently completed study considered missions such as a Jovian grand tour, a Uranus or Neptune orbiter and probe, and a Pluto flyby that can only be done with nuclear power. There are studies for missions beyond the outer boundaries of the solar system at distances of 100 to 1000 astronomical units. The NASA 90-day study on the space exploration initiative identified a need for nuclear reactors to power lunar surface bases and radioisotope power sources for use in lunar or Martian rovers, as well as considering options for advanced, nuclear propulsion systems for human missions to Mars

21 CFR 882.4725 - Radiofrequency lesion probe.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency lesion probe. 882.4725 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4725 Radiofrequency lesion probe. (a) Identification. A radiofrequency lesion probe is a device connected to a radiofrequency (RF...

In-vitro accuracy and reproducibility evaluation of probing depth measurements of selected periodontal probes

Directory of Open Access Journals (Sweden)

K.N. Al Shayeb

2014-01-01

Conclusion: Depth measurements with the Chapple UB-CF-15 probe were more accurate and reproducible compared to measurements with the Vivacare TPS and Williams 14 W probes. This in vitro model may be useful for intra-examiner calibration or clinician training prior to the clinical evaluation of patients or in longitudinal studies involving periodontal evaluation.

Determining frequentist confidence limits using a directed parameter space search

International Nuclear Information System (INIS)

Daniel, Scott F.; Connolly, Andrew J.; Schneider, Jeff

2014-01-01

We consider the problem of inferring constraints on a high-dimensional parameter space with a computationally expensive likelihood function. We propose a machine learning algorithm that maps out the Frequentist confidence limit on parameter space by intelligently targeting likelihood evaluations so as to quickly and accurately characterize the likelihood surface in both low- and high-likelihood regions. We compare our algorithm to Bayesian credible limits derived by the well-tested Markov Chain Monte Carlo (MCMC) algorithm using both multi-modal toy likelihood functions and the seven yr Wilkinson Microwave Anisotropy Probe cosmic microwave background likelihood function. We find that our algorithm correctly identifies the location, general size, and general shape of high-likelihood regions in parameter space while being more robust against multi-modality than MCMC.

Developing Wide-Field Spatio-Spectral Interferometry for Far-Infrared Space Applications

Science.gov (United States)

Leisawitz, David; Bolcar, Matthew R.; Lyon, Richard G.; Maher, Stephen F.; Memarsadeghi, Nargess; Rinehart, Stephen A.; Sinukoff, Evan J.

2012-01-01

Interferometry is an affordable way to bring the benefits of high resolution to space far-IR astrophysics. We summarize an ongoing effort to develop and learn the practical limitations of an interferometric technique that will enable the acquisition of high-resolution far-IR integral field spectroscopic data with a single instrument in a future space-based interferometer. This technique was central to the Space Infrared Interferometric Telescope (SPIRIT) and Submillimeter Probe of the Evolution of Cosmic Structure (SPECS) space mission design concepts, and it will first be used on the Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII). Our experimental approach combines data from a laboratory optical interferometer (the Wide-field Imaging Interferometry Testbed, WIIT), computational optical system modeling, and spatio-spectral synthesis algorithm development. We summarize recent experimental results and future plans.

SNAP: Small Next-generation Atmospheric Probe Concept

Science.gov (United States)

Sayanagi, K. M.; Dillman, R. A.; Atkinson, D. H.; Li, J.; Saikia, S.; Simon, A. A.; Spilker, T. R.; Wong, M. H.; Hope, D.

2017-12-01

We present a concept for a small, atmospheric probe that could be flexibly added to future missions that orbit or fly-by a giant planet as a secondary payload, which we call the Small Next-generation Atmospheric Probe (SNAP). SNAP's main scientific objectives are to determine the vertical distribution of clouds and cloud-forming chemical species, thermal stratification, and wind speed as a function of depth. As a case study, we present the advantages, cost and risk of adding SNAP to the future Uranus Orbiter and Probe flagship mission; in combination with the mission's main probe, SNAP would perform atmospheric in-situ measurements at a second location, and thus enable and enhance the scientific objectives recommended by the 2013 Planetary Science Decadal Survey and the 2014 NASA Science Plan to determine atmospheric spatial variabilities. We envision that the science objectives can be achieved with a 30-kg entry probe 0.5m in diameter (less than half the size of the Galileo probe) that reaches 5-bar pressure-altitude and returns data to Earth via the carrier spacecraft. As the baseline instruments, the probe will carry an Atmospheric Structure Instrument (ASI) that measures the temperature, pressure and acceleration, a carbon nanotube-based NanoChem atmospheric composition sensor, and an Ultra-Stable Oscillator (USO) to conduct a Doppler Wind Experiment (DWE). We also catalog promising technologies currently under development that will strengthen small atmospheric entry probe missions in the future. While SNAP is applicable to multiple planets, we examine the feasibility, benefits and impacts of adding SNAP to the Uranus Orbiter and Probe flagship mission. Our project is supported by NASA PSDS3 grant NNX17AK31G.

Study, design and manufacture eddy current probes for industry applications

International Nuclear Information System (INIS)

Nguyen Phuc; Nguyen Van Thuy; Vuong Binh Duong; Do Minh Duc; Trinh Dinh Truong; Tran Trong Duc; Do Tung Khanh; Dang Quang Trung

2016-01-01

This study is based on the studying, designing and manufacturing of eddy current probes for industry applications. The main tasks of this study include: i) Describes the overview and classification of eddy current probes (which can be classified into three categories based on the mode of operation: absolute eddy current probe, differential eddy current probe and reflect eddy current probe); ii) Describes the three methods of probe designing and manufacturing (including experimental, analytical and numerical designs); iii) Describes the designing and manufacturing of eddy current probes for industry applications, which based on experimental and analytical methods. Based on this study, we have successfully manufactured some current probes (including absolute eddy current probe, differential eddy current probe and reflect eddy current probe) for surface and tube inspections. (author)

Small-Scale Design Experiments as Working Space for Larger Mobile Communication Challenges

Science.gov (United States)

Lowe, Sarah; Stuedahl, Dagny

2014-01-01

In this paper, a design experiment using Instagram as a cultural probe is submitted as a method for analyzing the challenges that arise when considering the implementation of social media within a distributed communication space. It outlines how small, iterative investigations can reveal deeper research questions relevant to the education of…