Science.gov

Sample records for rich traditions bright

  1. Traditional cheeses: rich and diverse microbiota with associated benefits.

    PubMed

    Montel, Marie-Christine; Buchin, Solange; Mallet, Adrien; Delbes-Paus, Céline; Vuitton, Dominique A; Desmasures, Nathalie; Berthier, Françoise

    2014-05-02

    The risks and benefits of traditional cheeses, mainly raw milk cheeses, are rarely set out objectively, whence the recurrent confused debate over their pros and cons. This review starts by emphasizing the particularities of the microbiota in traditional cheeses. It then describes the sensory, hygiene, and possible health benefits associated with traditional cheeses. The microbial diversity underlying the benefits of raw milk cheese depends on both the milk microbiota and on traditional practices, including inoculation practices. Traditional know-how from farming to cheese processing helps to maintain both the richness of the microbiota in individual cheeses and the diversity between cheeses throughout processing. All in all more than 400 species of lactic acid bacteria, Gram and catalase-positive bacteria, Gram-negative bacteria, yeasts and moulds have been detected in raw milk. This biodiversity decreases in cheese cores, where a small number of lactic acid bacteria species are numerically dominant, but persists on the cheese surfaces, which harbour numerous species of bacteria, yeasts and moulds. Diversity between cheeses is due particularly to wide variations in the dynamics of the same species in different cheeses. Flavour is more intense and rich in raw milk cheeses than in processed ones. This is mainly because an abundant native microbiota can express in raw milk cheeses, which is not the case in cheeses made from pasteurized or microfiltered milk. Compared to commercial strains, indigenous lactic acid bacteria isolated from milk/cheese, and surface bacteria and yeasts isolated from traditional brines, were associated with more complex volatile profiles and higher scores for some sensorial attributes. The ability of traditional cheeses to combat pathogens is related more to native antipathogenic strains or microbial consortia than to natural non-microbial inhibitor(s) from milk. Quite different native microbiota can protect against Listeria monocytogenes in

  2. The International Society for Sexual Medicine: A Rich History and a Bright Future.

    PubMed

    Lewis, Ronald W

    2013-07-01

    Based upon physical presence at most of the historical moments of the development of the International Society for Sexual Medicine (ISSM), extensive personal records on meetings and correspondence associated with the business and the work of the International Society for Sexual and Impotence Research and the ISSM, and information provided by the business office of the ISSM, a review paper was created to present to the reader an accurate history of the ISSM. The article is divided into the early beginnings of the idea of the field of sexual medicine, followed by the organization of what was to become eventually the International Society for Sexual Medicine, description of the development of biennial meetings and some of the major events that occurred at these meetings, a description of officers and leaders of the society and some of their key contributions, other meetings that the ISSM was actively involved in in the field of sexual medicine, a detailed discussion of publications and communications of the organization, and finally a description of the involvement of the ISSM with the recognition of scientific achievement and research in the field. This history is indeed very rich and unique for the parallelism to the development of the entire field of sexual medicine as a true science. The author has spent a great deal of time in making sure that there is written material that substantiates the history that is outlined in this document. It is provided to the reader as a true historical perspective on the ISSM. Lewis RW. The International Society for Sexual Medicine: A rich history and a bright future. Sex Med Rev 2013; 1:65-75. Copyright © 2013 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

  3. A Spectroscopic Survey and Analysis of Bright, Hydrogen-rich White Dwarfs

    NASA Astrophysics Data System (ADS)

    Gianninas, A.; Bergeron, P.; Ruiz, M. T.

    2011-12-01

    We have conducted a spectroscopic survey of over 1300 bright (V <= 17.5), hydrogen-rich white dwarfs based largely on the last published version of the McCook & Sion catalog. The complete results from our survey, including the spectroscopic analysis of over 1100 DA white dwarfs, are presented. High signal-to-noise ratio optical spectra were obtained for each star and were subsequently analyzed using our standard spectroscopic technique where the observed Balmer line profiles are compared to synthetic spectra computed from the latest generation of model atmospheres appropriate for these stars. First, we present the spectroscopic content of our sample, which includes many misclassifications as well as several DAB, DAZ, and magnetic white dwarfs. Next, we look at how the new Stark broadening profiles affect the determination of the atmospheric parameters. When necessary, specific models and analysis techniques are used to derive the most accurate atmospheric parameters possible. In particular, we employ M dwarf templates to obtain better estimates of the atmospheric parameters for those white dwarfs that are in DA+dM binary systems. Certain unique white dwarfs and double-degenerate binary systems are also analyzed in greater detail. We then examine the global properties of our sample including the mass distribution and their distribution as a function of temperature. We then proceed to test the accuracy and robustness of our method by comparing our results to those of other surveys such as SPY and Sloan Digital Sky Survey. Finally, we revisit the ZZ Ceti instability strip and examine how the determination of its empirical boundaries is affected by the latest line profile calculations. Based on observations made with ESO Telescopes at the La Silla or Paranal Observatories under program ID 078.D-0824(A).

  4. A SPECTROSCOPIC SURVEY AND ANALYSIS OF BRIGHT, HYDROGEN-RICH WHITE DWARFS

    SciTech Connect

    Gianninas, A.; Bergeron, P.; Ruiz, M. T. E-mail: bergeron@astro.umontreal.ca

    2011-12-20

    We have conducted a spectroscopic survey of over 1300 bright (V {<=} 17.5), hydrogen-rich white dwarfs based largely on the last published version of the McCook and Sion catalog. The complete results from our survey, including the spectroscopic analysis of over 1100 DA white dwarfs, are presented. High signal-to-noise ratio optical spectra were obtained for each star and were subsequently analyzed using our standard spectroscopic technique where the observed Balmer line profiles are compared to synthetic spectra computed from the latest generation of model atmospheres appropriate for these stars. First, we present the spectroscopic content of our sample, which includes many misclassifications as well as several DAB, DAZ, and magnetic white dwarfs. Next, we look at how the new Stark broadening profiles affect the determination of the atmospheric parameters. When necessary, specific models and analysis techniques are used to derive the most accurate atmospheric parameters possible. In particular, we employ M dwarf templates to obtain better estimates of the atmospheric parameters for those white dwarfs that are in DA+dM binary systems. Certain unique white dwarfs and double-degenerate binary systems are also analyzed in greater detail. We then examine the global properties of our sample including the mass distribution and their distribution as a function of temperature. We then proceed to test the accuracy and robustness of our method by comparing our results to those of other surveys such as SPY and Sloan Digital Sky Survey. Finally, we revisit the ZZ Ceti instability strip and examine how the determination of its empirical boundaries is affected by the latest line profile calculations.

  5. Spectrum of Bright Transient ASASSN-13ax: Hydrogen-Rich Dwarf Nova in Outburst

    NASA Astrophysics Data System (ADS)

    Copperwheat, C. M.; Bersier, D. F.; Shappee, B. J.; Kochanek, C. S.; Stanek, K. Z.; Jencson, J.; Basu, U.; Beacom, J. F.; Prieto, J. L.; Szczygiel, D.; Pojmanski, G.; Dubberley, M.; Elphick, M.; Foale, S.; Hawkins, E.; Mullens, D.; Rosing, W.; Ross, R.; Walker, Z.; Brimacombe, J.

    2013-07-01

    We observed the bright transient ASASSN-13ax (ATEL #5186) on UT 2013 July 2.9 for 15 minutes with the FRODOspec spectrograph mounted on the robotic 2.0m Liverpool Telescope (LT). We obtained two simultaneous spectra, one covering the wavelength range 390-570 nm with R=2600, and one covering 580-900 nm with R=2200. We detect a blue continuum with broad Balmer absorption lines, as well as Helium absorption at 447 nm.

  6. Very deep spectroscopy of the bright Saturn nebula NGC 7009 - II. Analysis of the rich optical recombination spectrum

    NASA Astrophysics Data System (ADS)

    Fang, X.; Liu, X.-W.

    2013-03-01

    In Paper I, we presented a deep, long-slit spectrum of the bright Saturn nebula NGC 7009. Numerous permitted lines emitted by the C+, N+, O+ and Ne+ ions were detected. Gaussian profile fitting to the spectrum yielded more than 1000 lines, the majority of which are optical recombination lines (ORLs) of heavy-element ions. In the current paper, we present a critical analysis of the rich optical recombination spectrum of NGC 7009, in the context of the bi-abundance nebular model proposed by Liu et al. Transitions from individual multiplets are checked carefully for potential blended lines. The observed relative intensities are compared with the theoretical predictions based on high-quality effective recombination coefficients, now available for the recombination line spectrum of a number of heavy-element ions. The possibility of plasma diagnostics using the ORLs of various heavy-element ions is discussed in detail. The line ratios that can be used to determine electron temperature are presented for each ion, although there is still a lack of adequate atomic data and some of the lines are still not detected in the spectrum of NGC 7009 due to weakness and/or line blending. Plasma diagnostics based on the N II and O II recombination spectra both yield electron temperatures close to 1000 K, which is lower than those derived from the collisionally excited line (CEL) ratios (e.g. the [O III] and [N II] nebular-to-auroral line ratios; see Paper I for details) by nearly one order of magnitude. The very low temperatures yielded by the O II and N II ORLs indicate that they originate from very cold regions. The C2+/H+, N2+/H+, O2+/H+ and Ne2+/H+ ionic abundance ratios derived from ORLs are consistently higher, by about a factor of 5, than the corresponding values derived from CELs. In calculating the ORL ionic abundance ratios, we have used the newly available high-quality effective recombination coefficients, and adopted an electron temperature of ˜1000 K, as given by the ORL

  7. A global perspective of the richness and evenness of traditional crop-variety diversity maintained by farming communities

    PubMed Central

    Jarvis, Devra I.; Brown, Anthony H. D.; Cuong, Pham Hung; Collado-Panduro, Luis; Latournerie-Moreno, Luis; Gyawali, Sanjaya; Tanto, Tesema; Sawadogo, Mahamadou; Mar, Istvan; Sadiki, Mohammed; Hue, Nguyen Thi-Ngoc; Arias-Reyes, Luis; Balma, Didier; Bajracharya, Jwala; Castillo, Fernando; Rijal, Deepak; Belqadi, Loubna; Rana, Ram; Saidi, Seddik; Ouedraogo, Jeremy; Zangre, Roger; Rhrib, Keltoum; Chavez, Jose Luis; Schoen, Daniel; Sthapit, Bhuwon; De Santis, Paola; Fadda, Carlo; Hodgkin, Toby

    2008-01-01

    Varietal data from 27 crop species from five continents were drawn together to determine overall trends in crop varietal diversity on farm. Measurements of richness, evenness, and divergence showed that considerable crop genetic diversity continues to be maintained on farm, in the form of traditional crop varieties. Major staples had higher richness and evenness than nonstaples. Variety richness for clonal species was much higher than that of other breeding systems. A close linear relationship between traditional variety richness and evenness (both transformed), empirically derived from data spanning a wide range of crops and countries, was found both at household and community levels. Fitting a neutral “function” to traditional variety diversity relationships, comparable to a species abundance distribution of “neutral ecology,” provided a benchmark to assess the standing diversity on farm. In some cases, high dominance occurred, with much of the variety richness held at low frequencies. This suggested that diversity may be maintained as an insurance to meet future environmental changes or social and economic needs. In other cases, a more even frequency distribution of varieties was found, possibly implying that farmers are selecting varieties to service a diversity of current needs and purposes. Divergence estimates, measured as the proportion of community evenness displayed among farmers, underscore the importance of a large number of small farms adopting distinctly diverse varietal strategies as a major force that maintains crop genetic diversity on farm. PMID:18362337

  8. A global perspective of the richness and evenness of traditional crop-variety diversity maintained by farming communities.

    PubMed

    Jarvis, Devra I; Brown, Anthony H D; Cuong, Pham Hung; Collado-Panduro, Luis; Latournerie-Moreno, Luis; Gyawali, Sanjaya; Tanto, Tesema; Sawadogo, Mahamadou; Mar, Istvan; Sadiki, Mohammed; Hue, Nguyen Thi-Ngoc; Arias-Reyes, Luis; Balma, Didier; Bajracharya, Jwala; Castillo, Fernando; Rijal, Deepak; Belqadi, Loubna; Rana, Ram; Saidi, Seddik; Ouedraogo, Jeremy; Zangre, Roger; Rhrib, Keltoum; Chavez, Jose Luis; Schoen, Daniel; Sthapit, Bhuwon; De Santis, Paola; Fadda, Carlo; Hodgkin, Toby

    2008-04-08

    Varietal data from 27 crop species from five continents were drawn together to determine overall trends in crop varietal diversity on farm. Measurements of richness, evenness, and divergence showed that considerable crop genetic diversity continues to be maintained on farm, in the form of traditional crop varieties. Major staples had higher richness and evenness than nonstaples. Variety richness for clonal species was much higher than that of other breeding systems. A close linear relationship between traditional variety richness and evenness (both transformed), empirically derived from data spanning a wide range of crops and countries, was found both at household and community levels. Fitting a neutral "function" to traditional variety diversity relationships, comparable to a species abundance distribution of "neutral ecology," provided a benchmark to assess the standing diversity on farm. In some cases, high dominance occurred, with much of the variety richness held at low frequencies. This suggested that diversity may be maintained as an insurance to meet future environmental changes or social and economic needs. In other cases, a more even frequency distribution of varieties was found, possibly implying that farmers are selecting varieties to service a diversity of current needs and purposes. Divergence estimates, measured as the proportion of community evenness displayed among farmers, underscore the importance of a large number of small farms adopting distinctly diverse varietal strategies as a major force that maintains crop genetic diversity on farm.

  9. A Comparison of Simplified-Visually Rich and Traditional Presentation Styles

    ERIC Educational Resources Information Center

    Johnson, Douglas A.; Christensen, Jack

    2011-01-01

    Microsoft PowerPoint and similar presentation tools have become commonplace in higher education, yet there is very little research on the effectiveness of different PowerPoint formats for implementing this software. This study compared two PowerPoint presentation techniques: a more traditional format employing heavy use of bullet points with text…

  10. A Comparison of Simplified-Visually Rich and Traditional Presentation Styles

    ERIC Educational Resources Information Center

    Johnson, Douglas A.; Christensen, Jack

    2011-01-01

    Microsoft PowerPoint and similar presentation tools have become commonplace in higher education, yet there is very little research on the effectiveness of different PowerPoint formats for implementing this software. This study compared two PowerPoint presentation techniques: a more traditional format employing heavy use of bullet points with text…

  11. Polyphenolic rich traditional plants and teas improve lipid stability in food test systems.

    PubMed

    Ramsaha, Srishti; Aumjaud, B Esha; Neergheen-Bhujun, Vidushi S; Bahorun, Theeshan

    2015-02-01

    The deleterious effects of lipid autoxidation are of major concern to the food industry and can be prevented by food antioxidants. In this vein, the phenolic contents and antioxidant potential of traditional plants of Mauritius such as P. betle L. (Piperaceae), M. koenigii L. Sprengel. (Rutaceae), O. gratissimum L. (Lamiaceae), O. tenuiflorum L. (Lamiaceae), and commercially available Mauritian green and black teas were evaluated. Their ferric reducing antioxidant power (FRAP) were compared to that of butylated hydroxytoluene (BHT) with the following order of potency: BHT > "Natural" commercial green tea > "Black Label" commercial black tea > O. gratissimum > P. betle > O. tenuiflorum > M. koenigii. The trolox equivalent antioxidant capacity (TEAC) assay reflected a similar antioxidative order for BHT and "Natural" commercial green tea, with however P. betle, O. tenuiflorum and O. gratissimum exhibiting higher activities than "Black Label" commercial black tea and M. koenigii. Based on their potent antioxidant capacity, P. betle (0.2 % m/m) and O. tenuiflorum (0.2 % m/m) extracts, and green tea (0.1 % m/m) infusate were compared with BHT (0.02 % m/m) on their ability to retard lipid oxidation in unstripped sunflower oil and mayonnaise during storage at 40 °C. P. betle and green tea were more effective than BHT in both food systems. Moreover, odour evaluation by a sensory panel showed that the plant extracts and green tea infusate effectively delayed the development of rancid odours in unstripped sunflower oil and mayonnaise (p < 0.05).

  12. Role of human gut microbiota metabolism in the anti-inflammatory effect of traditionally used ellagitannin-rich plant materials.

    PubMed

    Piwowarski, Jakub P; Granica, Sebastian; Zwierzyńska, Marta; Stefańska, Joanna; Schopohl, Patrick; Melzig, Matthias F; Kiss, Anna K

    2014-08-08

    Ellagitannin-rich plant materials are widely used in traditional medicine as effective, internally used anti-inflammatory agents. Due to the not well-established bioavailability of ellagitannins, the mechanisms of observed therapeutic effects following oral administration still remain unclear. The aim of the study was to evaluate if selected ellagitannin-rich plant materials could be the source of bioavailable gut microbiota metabolites, i.e. urolithins, together with determination of the anti-inflammatory activity of the metabolites produced on the THP-1 cell line derived macrophages model. The formation of urolithins was determined by ex vivo incubation of human fecal samples with aqueous extracts from selected plant materials. The anti-inflammatory activity study of metabolites was determined on PMA differentiated, IFN-γ and LPS stimulated, human THP-1 cell line-derived macrophages. The formation of urolithin A, B and C by human gut microbiota was established for aqueous extracts from Filipendula ulmaria (L.) Maxim. herb (Ph. Eur.), Geranium pratense L. herb, Geranium robertianum L. herb, Geum urbanum L. root and rhizome, Lythrum salicaria L. herb (Ph. Eur.), Potentilla anserina L. herb, Potentilla erecta (L.) Raeusch rhizome (Ph. Eur.), Quercus robur L. bark (Ph. Eur.), Rubus idaeus L. leaf, Rubus fruticosus L. and pure ellagitannin vescalagin. Significant inhibition of TNF-α production was determined for all urolithins, while for the most potent urolithin A inhibition was observed at nanomolar concentrations (at 0.625 μM 29.2±6.4% of inhibition). Urolithin C was the only compound inhibiting IL-6 production (at 0.625 μM 13.9±2.2% of inhibition). The data obtained clearly indicate that in the case of peroral use of the examined ellagitannin-rich plant materials the bioactivity of gut microbiota metabolites, i.e. urolithins, has to be taken under consideration. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  13. Bright Enceladus

    NASA Image and Video Library

    2011-02-14

    Saturn moon Enceladus reflects sunlight brightly while the planet and its rings fill the background in this view from NASA Cassini spacecraft. Enceladus is one of the most reflective bodies in the solar system.

  14. Nutrient-rich versus nutrient-poor foods for depressed patients based on Iranian Traditional Medicine resources

    PubMed Central

    Tavakkoli-Kakhki, Mandana; Eslami, Saeid; Motavasselian, Malihe

    2015-01-01

    Objectives: Considering the positive effects of certain nutrients on depression, increasingly prevalent in the contemporary societies, we investigated the nutritional content of prescribed and prohibited foodstuffs for depressed patients in Iranian Traditional Medicine resources. Materials and Methods: In order to conduct the study, credible sources of Iranian Traditional Medicine were primarily reviewed for the prescribed and prohibited foodstuffs for depressed patients. USDA database, as a well-known and valuable source, was then visited to determine the amount of effective nutrients in each foodstuff. Finally, the obtained amounts were compared with each other in three food groups, namely vegetables, fruits and nuts and also high protein products. Results: In Iranian Traditional Medicine texts, the following are prescribed for depression management: basil, coriander, spinach, lettuce, squash, peppermint, dill, chicory, celery, chard, quince, cucumber, watermelon, grape, peach, pomegranate, banana, apple, currant, pistachio, dried fig, almond, egg, chicken, lamb, and trout; cabbage, eggplant, onion, garlic, broad beans, lentils, and beef, meanwhile, are prohibited. In this regard, the effective nutritional content of these foodstuffs was obtained and then compared in the three food groups. Conclusion: This study revealed that spinach, lettuce, chicory, and squash (vegetables), pomegranate and almond (fruits and nuts) and ultimately trout (high protein products) are the best effective foodstuffs on depressed patients from nutritional content aspect. PMID:26445711

  15. Traditional Practicing with Arsenic Rich Water in Fish Industries Leads to Health Hazards in West Bengal and North-Eastern States of India

    NASA Astrophysics Data System (ADS)

    Kashyap, C. A.

    2014-12-01

    The supply of good quality food is main necessity for economic and social health of urban and rural population throughout the globe. This study comes to know the severity of As in the west Bengal and north-eastern states of the India. Over the 75% large population of India lives in villages and associated with farming and its related work. West Bengal is the densest populated area of India, fish and rice is the staple food as well as in north-eastern states. For the fulfil demand of fish large population the area are used fisheries as the business. Arsenic contamination in ground water is major growing threat to worldwide drinking water resources. High As contamination in water have been reported in many parts of the world Chandrasekharam et al., 2001; Smedley and Kinniburgh, 2002; Farooq et al., 2010). In context to West Bengal and north-east states of India arsenic is main problem in the food chain. These areas are very rich in arsenic many fold higher concentrations of Arsenic than their respective WHO permissible limits have been reported in the water. Over the 36 million people in Bengal delta are at risk due to drinking of As contaminated water (Nordstrom, 2002). The highest concentration of arsenic (535 μg/L Chandrashekhar et al. 2012) was registered from Ngangkha Lawai Mamang Leikai area of Bishnupur district which is fifty fold of the WHO limit for arsenic and tenfold of Indian permissible limit. With the continuous traditional practicing (As rich water pond) and untreated arsenic rich water in fish industries leads to health hazards. A sustainable development in aquaculture should comprise of various fields including environmental, social, cultural and economic aspects. A scientific study has to be needed for the overcome on this problem and rain harvested water may be used for reduce the arsenic problems in fisheries.

  16. Hydrocarbon source potential and maturation in eocene New Zealand vitrinite-rich coals: Insights from traditional coal analyses, and Rock-Eval and biomarker studies

    USGS Publications Warehouse

    Newman, J.; Price, L.C.; Johnston, J.H.

    1997-01-01

    The results of traditional methods of coal characterisation (proximate, specific energy, and ultimate analyses) for 28 Eocene coal samples from the West Coast of New Zealand correspond well with biomarker ratios and Rock-Eval analyses. Isorank variations in vitrinite fluorescence and reflectance recorded for these samples are closely related to their volatile-matter content, and therefore indicate that the original vitrinite chemistry is a key controlling factor. By contrast, the mineral-matter content and the proportion of coal macerals present appear to have had only a minor influence on the coal samples' properties. Our analyses indicate that a number of triterpane biomarker ratios show peak maturities by high volatile bituminous A rank; apparent maturities are then reversed and decline at the higher medium volatile bituminous rank. The Rock-Eval S1 +S2 yield also maximizes by high volatile bituminous A rank, and then declines; however, this decline is retarded in samples with the most hydrogen-rich (perhydrous) vitrinites. These Rock-Eval and biomarker trends, as well as trends in traditional coal analyses, are used to define the rank at which expulsion of gas and oil occurs from the majority of the coals. This expulsion commences at high volatile A bituminous rank, and persists up to the threshold of medium volatile bituminous rank (c. 1.1% Ro ran. or 1.2% Ro max in this sample set), where marked hydrocarbon expulsion from perhydrous vitrinites begins to take place.

  17. The analogy between stereo depth and brightness.

    PubMed

    Brookes, A; Stevens, K A

    1989-01-01

    Apparent depth in stereograms exhibits various simultaneous-contrast and induction effects analogous to those reported in the luminance domain. This behavior suggests that stereo depth, like brightness, is reconstructed, ie recovered from higher-order spatial derivatives or differences of the original signal. The extent to which depth is analogous to brightness is examined. There are similarities in terms of contrast effects but dissimilarities in terms of the lateral inhibition effects traditionally attributed to underlying spatial-differentiation operators.

  18. Do Low Surface Brightness Galaxies Host Stellar Bars?

    NASA Astrophysics Data System (ADS)

    Cervantes Sodi, Bernardo; Sánchez García, Osbaldo

    2017-09-01

    With the aim of assessing if low surface brightness galaxies host stellar bars and by studying the dependence of the occurrence of bars as a function of surface brightness, we use the Galaxy Zoo 2 data set to construct a large volume-limited sample of galaxies and then segregate these galaxies as having low or high surface brightness in terms of their central surface brightness. We find that the fraction of low surface brightness galaxies hosting strong bars is systematically lower than that found for high surface brightness galaxies. The dependence of the bar fraction on the central surface brightness is mostly driven by a correlation of the surface brightness with the spin and the gas richness of the galaxies, showing only a minor dependence on the surface brightness. We also find that the length of the bars is strongly dependent on the surface brightness, and although some of this dependence is attributed to the gas content, even at a fixed gas-to-stellar mass ratio, high surface brightness galaxies host longer bars than their low surface brightness counterparts, which we attribute to an anticorrelation of the surface brightness with the spin.

  19. Brightness of Moonlight.

    ERIC Educational Resources Information Center

    Garstang, R. H.

    1985-01-01

    Measurement of the brightness of moonlight by comparison with lamp-light from a low wattage light bulb is an elementary project in astronomy which illustrates scientific principles for the freshman level. Two methods used for the comparison (shadow brightness method and grease spot method) are explained, with suggestions and expected answers. (DH)

  20. Bright Patches on Ariel

    NASA Image and Video Library

    1998-12-05

    Distinct bright patches are visible on Ariel, the brightest of Uranus five largest satellites. NASA Voyager 2 obtained this image Jan. 22, 1986, from a distance of 2.52 million kilometers 1.56 million miles.

  1. Bright Lights, Green City

    NASA Image and Video Library

    2010-07-28

    Two extremely bright stars illuminate a greenish mist in this image from the new GLIMPSE360 survey from NASA Spitzer Space Telescope. The fog is comprised of hydrogen and carbon compounds called polycyclic aromatic hydrocarbons.

  2. Beyond Bright Rings

    NASA Image and Video Library

    2009-12-30

    The tiny moon Pandora appears beyond the bright disk of Saturn rings in this image taken by NASA Cassini spacecraft. Pandora orbits outside the F ring and, in this image, is farther from Cassini than the rings are.

  3. [Bright light therapy].

    PubMed

    Poirrier, R; Cambron, L

    2007-01-01

    Bright light therapy is a treatment that emerged in the eighties of the last century. It can be used in different pathologies such as seasonal affective disorders, major depressions, and many disorders of the wake-sleep rhythm, whether they are of primary or secondary origin. Important progress made at the basic neuroscience levels, allows today a sound understanding of the bright light mode of action. Moreover, the main indications are now the subject of consensus reports and meta-analyses which show good levels of evidence-based medicine. Bright light therapy constitutes a first choice indication in seasonal affective disorder. It is also perfectly possible to prescribe bright light therapy in the major depression disorders. It has been demonstrated that the effect size is the same as with antidepressants of reference. It is admitted nowadays that bright light therapy may be at least, an adjunct to pharmacotherapy, in order to accelerate the antidepressant effect onset, or to prolong this effect after withdrawal of the drug. Bright light therapy can also be viewed as an alternative to the pharmacological approach especially when this one is impossible, not tolerated or not accepted by the patient. The contraindications are rare.

  4. Comparison of Traditional Instruction on Reflection and Rotation in a Nepalese High School with an ICT-Rich, Student-Centered, Investigative Approach

    ERIC Educational Resources Information Center

    Mainali, Bhesh Raj; Heck, André

    2017-01-01

    A teacher-centered, examination-driven instructional approach emphasizing knowledge of facts and standard methods through drill-and-practice without use of Information and Communications Technology (ICT) is still dominant in Nepalese high schools. In this article, we present a classroom study in which the traditional instructional approach has…

  5. Traditional medicine for the rich and knowledgeable: challenging assumptions about treatment-seeking behaviour in rural and peri-urban Nepal

    PubMed Central

    Thorsen, Rikke Stamp; Pouliot, Mariève

    2016-01-01

    Traditional medicine is commonly assumed to be a crucial health care option for poor households in developing countries. However, little research has been done in Asia to quantify the reliance on traditional medicine and its determinants. This research contributes to filling in this knowledge gap using household survey data collected from 571 households in three rural and peri-urban sites in Nepal in 2012. Questions encompassed household socioeconomic characteristics, illness characteristics, and treatment-seeking behaviour. Treatment choice was investigated through bivariate analyses. Results show that traditional medicine, and especially self-treatment with medicinal plants, prevail as treatment options in both rural and peri-urban populations. Contrarily to what is commonly assumed, high income is an important determinant of use of traditional medicine. Likewise, knowledge of medicinal plants, age, education, gender and illness chronicity were also significant determinants. The importance of self-treatment with medicinal plants should inform the development of health policy tailored to people’s treatment-seeking behaviour. PMID:26130610

  6. Bright Spokes, Dark Shadow

    NASA Image and Video Library

    2010-04-06

    Bright spokes and the shadow of a moon grace Saturn B ring in this NASA Cassini spacecraft image. Spokes are radial markings scientists continue to study, and they can be seen here stretching from the far left to upper right of the image.

  7. High Brightness OLED Lighting

    SciTech Connect

    Spindler, Jeffrey; Kondakova, Marina; Boroson, Michael; Hamer, John

    2016-05-25

    In this work we describe the technology developments behind our current and future generations of high brightness OLED lighting panels. We have developed white and amber OLEDs with excellent performance based on the stacking approach. Current products achieve 40-60 lm/W, while future developments focus on achieving 80 lm/W or higher.

  8. A Bright Shining Lesson

    ERIC Educational Resources Information Center

    Hurowitz, Amanda

    2010-01-01

    Sometimes students come up with crazy ideas. When this author first started teaching at Thomas Jefferson High School for Science and Technology in Virginia five years ago, she had a sophomore share such an idea with her. He wanted to put solar panels on the school's roof as a way to reduce the school's carbon footprint and set a bright clean…

  9. Bright Fireball Over Georgia

    NASA Image and Video Library

    A camera in Cartersville, Ga., captured this view of a bright fireball over Georgia on the night of Mar. 7, 2012, at approx. 10:19:11 EST. The meteor was first recorded at an altitude of 51.5 miles...

  10. A Bright Shining Lesson

    ERIC Educational Resources Information Center

    Hurowitz, Amanda

    2010-01-01

    Sometimes students come up with crazy ideas. When this author first started teaching at Thomas Jefferson High School for Science and Technology in Virginia five years ago, she had a sophomore share such an idea with her. He wanted to put solar panels on the school's roof as a way to reduce the school's carbon footprint and set a bright clean…

  11. Bright Streak on Amalthea

    NASA Technical Reports Server (NTRS)

    2000-01-01

    These two images of Jupiter's small, irregularly shaped moon Amalthea, obtained by the camera onboard NASA's Galileo spacecraft in August 1999(left) and November 1999 (right), form a 'stereo pair' that helps scientists determine this moon's shape and the topography of its surface features. Features as small as 3.8 kilometers (2.4 miles) across can be resolved in these images, making them among the highest-resolution images ever taken of Amalthea.

    The large impact crater visible in both images, near the right-hand edge of Amalthea's disk, is about 40 kilometers (about 29 miles) across; two ridges, tall enough to cast shadows, extend from the top of the crater in a V-shape reminiscent of a 'rabbit ears' television antenna. To the left of these ridges, in the top center portion of Amalthea's disk, is a second large impact crater similar in size to the first crater. To the left of this second crater is a linear 'streak' of relatively bright material about 50 kilometers (31 miles) long. In previous spacecraft images of Amalthea taken from other viewing directions, this bright feature was thought to be a small, round, bright 'spot' and was given the name Ida. These new images reveal for the first time that Ida is actually a long, linear 'streak.' This bright streak may represent material ejected during the formation of the adjacent impact crater, or it may just mark the crest of a local ridge. Other patches of relatively bright material can be seen elsewhere on Amalthea's disk, although none of these other bright spots has Ida's linear shape.

    In both images, sunlight is coming from the left and north is approximately up. Note that the north pole of Amalthea is missing in the right-hand image (it was cut off by the edge of the camera frame). The bright streak, Ida, is on the side of the moon that faces permanently away from Jupiter, and the crater near the right-hand edge of the disk is in the center of Amalthea's leading side (the side of the moon that 'leads

  12. Bright Streak on Amalthea

    NASA Technical Reports Server (NTRS)

    2000-01-01

    These two images of Jupiter's small, irregularly shaped moon Amalthea, obtained by the camera onboard NASA's Galileo spacecraft in August 1999(left) and November 1999 (right), form a 'stereo pair' that helps scientists determine this moon's shape and the topography of its surface features. Features as small as 3.8 kilometers (2.4 miles) across can be resolved in these images, making them among the highest-resolution images ever taken of Amalthea.

    The large impact crater visible in both images, near the right-hand edge of Amalthea's disk, is about 40 kilometers (about 29 miles) across; two ridges, tall enough to cast shadows, extend from the top of the crater in a V-shape reminiscent of a 'rabbit ears' television antenna. To the left of these ridges, in the top center portion of Amalthea's disk, is a second large impact crater similar in size to the first crater. To the left of this second crater is a linear 'streak' of relatively bright material about 50 kilometers (31 miles) long. In previous spacecraft images of Amalthea taken from other viewing directions, this bright feature was thought to be a small, round, bright 'spot' and was given the name Ida. These new images reveal for the first time that Ida is actually a long, linear 'streak.' This bright streak may represent material ejected during the formation of the adjacent impact crater, or it may just mark the crest of a local ridge. Other patches of relatively bright material can be seen elsewhere on Amalthea's disk, although none of these other bright spots has Ida's linear shape.

    In both images, sunlight is coming from the left and north is approximately up. Note that the north pole of Amalthea is missing in the right-hand image (it was cut off by the edge of the camera frame). The bright streak, Ida, is on the side of the moon that faces permanently away from Jupiter, and the crater near the right-hand edge of the disk is in the center of Amalthea's leading side (the side of the moon that 'leads

  13. Bright Solar Flare

    NASA Image and Video Library

    2017-09-27

    A bright solar flare is captured by the EIT 195Å instrument on 1998 May 2. A solar flare (a sudden, rapid, and intense variation in brightness) occurs when magnetic energy that has built up in the solar atmosphere is suddenly released, launching material outward at millions of km per hour. The Sun’s magnetic fields tend to restrain each other and force the buildup of tremendous energy, like twisting rubber bands, so much that they eventually break. At some point, the magnetic lines of force merge and cancel in a process known as magnetic reconnection, causing plasma to forcefully escape from the Sun. Credit: NASA/GSFC/SOHO/ESA To learn more go to the SOHO website: sohowww.nascom.nasa.gov/home.html To learn more about NASA's Sun Earth Day go here: sunearthday.nasa.gov/2010/index.php

  14. Little Bright Spot

    NASA Image and Video Library

    2015-01-12

    A bright spot can be seen on the left side of Rhea in this image. The spot is the crater Inktomi, named for a Lakota spider spirit. Inktomi is believed to be the youngest feature on Rhea (949 miles or 1527 kilometers across). The relative youth of the feature is evident by its brightness. Material that is newly excavated from below the moon's surface and tossed across the surface by a cratering event, appears bright. But as the newly exposed surface is subjected to the harsh space environment, it darkens. This is one technique scientists use to date features on surfaces. This view looks toward the trailing hemisphere of Rhea. North on Rhea is up and rotated 21 degrees to the left. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 29, 2013. The view was obtained at a distance of approximately 1.0 million miles (1.6 million kilometers) fro http://photojournal.jpl.nasa.gov/catalog/PIA18300

  15. Bright field illumination system

    NASA Technical Reports Server (NTRS)

    Huber, Edward D. (Inventor)

    1998-01-01

    A Bright Field Illumination system for inspecting a range of characteristically different kinds of defects, depressions, and ridges in a selected material surface. The system has an illumination source placed near a first focus of an elliptical reflector. In addition, a camera facing the inspected area is placed near the illumination source and the first focus. The second focus of the elliptical reflector is located at a distance approximately twice the elliptical reflector's distance above the inspected surface. The elliptical reflector directs the light from the source onto the inspected surface. Due to the shape of the elliptical reflector, light that is specularly reflected from the inspected surface is directed into the camera is which located at the position of the reflected second focus of the ellipse. This system creates a brightly lighted background field against which damage sites appear as high contrast dark objects which can be easily detected by a person or an automated inspection system. In addition, the Bright Field Illumination system and method can be used in combination with a vision inspection system providing for multiplexed illumination and data handling of multiple kinds of surface characteristics including abrupt and gradual surface variations and differences between measured characteristics of different kinds and prior instruments.

  16. Quasars in rich galaxy clusters

    NASA Technical Reports Server (NTRS)

    Ellingson, Erica; Yee, Howard K. C.

    1993-01-01

    The evolution of AGN activity in rich clusters of galaxies is found to be approximately 5 times more rapid than that in poor clusters. This rapid evolution may be driven by evolution in the dynamics of galaxy cluster cores. Results from our spectroscopic studies of galaxies associated with quasars are consistent with this scenario, in that bright AGN are preferentially found in regions of lower velocity dispersion. Alternately, the evolution may be driven by formation of a dense intra-cluster medium (ICM). Galaxies close to quasars in rich cluster cores are much bluer (presumably gas rich) than galaxies in the cores of other rich clusters, in support of this model.

  17. Easy way to estimate meteor brightness on TV frames

    NASA Astrophysics Data System (ADS)

    Leonov, V. A.; Bagrov, A. V.

    2016-01-01

    The traditional method of the meteor brightness measurements claims that the meteor brightness is equal to the stellar magnitude of a star that looks like a meteor in the brightest point of its track. This rule was convenient for the comparison of meteor observations by different observers and for the analysis of the brightness distributions of meteors from observed showers. This traditional method suffers from systematic errors, particularly those that arise from using stellar brightness measured in specific spectral wave bands different from the observer's ones, but mainly due to neglecting the influence of the meteor angular velocity on the real meteor brightness. To get a proper estimate of the meteor brightness that is a measure of the ground meteor illumination in the non-systematic units, an observer must take into account that the effective exposition of a meteor image in any resolution element of its track is a few times shorter than the corresponding exposition of a star image in the same frame. We propose a very simple method for improved estimations of meteor brightness by applying a correction to the meteor stellar magnitude obtained within the traditional framework.

  18. Kiloamp high-brightness beams

    SciTech Connect

    Caporaso, G.J.

    1987-01-01

    Brightness preservation of high-current relativistic electron beams under two different types of transport is discussed. Recent progress in improving the brightness of laser-guided beams in the Advanced Test Accelerator is reviewed. A strategy for the preservation of the brightness of space-charge-dominated beams in a solenoidal transport system is presented.

  19. Low surface brightness galaxies

    NASA Technical Reports Server (NTRS)

    Vanderhulst, J. M.; Deblok, W. J. G.; Mcgaugh, S. S.; Bothun, G. D.

    1993-01-01

    A program to investigate the properties of low surface brightness (LSB) galaxies involving surface photometry in U, B, V, R, I, and H-alpha, HI imaging with the Westerbork Synthesis Radio Telescope (WSRT) and the very large array (VLA) and spectrophotometry of H2 regions in LSB galaxies is underway. The goal is to verify the idea that LSB galaxies have low star formation rates because the local gas density falls below the critical density for star formation, and to study the stellar population and abundances in LSB galaxies. Such information should help understanding the evolutionary history of LSB galaxies. Some preliminary results are reported.

  20. Bright Loops at 171

    NASA Technical Reports Server (NTRS)

    2007-01-01

    STEREO was able to capture bright loops in exquisite detail as they were arcing above an active region (May 26, 2007) over an 18 hour period. What we are actually seeing are charged particles spinning along magnetic field lines that extend above the Sun's surface. Active regions are areas of intense magnetic activity and often the source of solar storms. In fact, the clip ends with a flourish in which a small coronal mass ejection (CME) blows out into space. This is from the STEREO Ahead spacecraft at the 171 Angstroms wavelength in extreme ultraviolet light.

  1. Large, Bright Wind Ripples

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-397, 20 June 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows large, relatively bright ripples of windblown sediment in the Sinus Sabaeus region south of Schiaparelli Basin. The surrounding substrate is thickly mantled by very dark material, possibly windblown silt that settled out of the atmosphere. The picture is located near 7.1oS, 343.7oW. Sunlight illuminates the scene from the left.

  2. Large Bright Ripples

    NASA Technical Reports Server (NTRS)

    2004-01-01

    3 February 2004 Wind is the chief agent of change on Mars today. Wind blows dust and it can move coarser sediment such as sand and silt. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows bright ripples or small dunes on the floors of troughs northeast of Isidis Planitia near 31.1oN, 244.6oW. The picture covers an area 3 km (1.9 mi) wide; sunlight illuminates the scene from the lower left.

  3. HI Surface brightness mapping

    NASA Astrophysics Data System (ADS)

    Pen, Ue-Li; Staveley-Smith, Lister; Chang, Tzu-Ching; Peterson, Jeff; Bandura, Kevin

    2008-04-01

    We propose to scan the 2dF survey field with Parkes multibeam in driftscan mode to make a map to cross correlate with galaxy redshifts. This allows a statistical detection of HI large scale structure out to z=0.15. In this cross correlation, the HI in ALL galaxies contributes, not only the bright ones, which significantly boosts the sensitivity. The proposed 40 hours on the fields result in a forecasted 20 sigma detection. The survey volume is 10 million cubic megaparsec, which contain 10^15 solar masses of hydrogen.

  4. Bright Loops at 171

    NASA Technical Reports Server (NTRS)

    2007-01-01

    STEREO was able to capture bright loops in exquisite detail as they were arcing above an active region (May 26, 2007) over an 18 hour period. What we are actually seeing are charged particles spinning along magnetic field lines that extend above the Sun's surface. Active regions are areas of intense magnetic activity and often the source of solar storms. In fact, the clip ends with a flourish in which a small coronal mass ejection (CME) blows out into space. This is from the STEREO Ahead spacecraft at the 171 Angstroms wavelength in extreme ultraviolet light.

  5. High brightness electron sources

    SciTech Connect

    Sheffield, R.L.

    1995-07-01

    High energy physics accelerators and free electron lasers put increased demands on the electron beam sources. This paper describes the present research on attaining intense bright electron beams using photoinjectors. Recent results from the experimental programs will be given. The performance advantages and difficulties presently faced by researchers will be discussed, and the following topics will be covered. Progress has been made in photocathode materials, both in lifetime and quantum efficiency. Cesium telluride has demonstrated significantly longer lifetimes than cesium antimonide at 10{sup {minus}8} torr. However, the laser system is more difficult because cesium telluride requires quadrupled YLF instead of the doubled YLF required for cesium antimonide. The difficulty in using photoinjectors is primarily the drive laser, in particular the amplitude stability. Finally, emittance measurements of photoinjector systems can be complicated by the non-thermal nature of the electron beam. An example of the difficulty in measuring beam emittance is given.

  6. High brightness electron accelerator

    DOEpatents

    Sheffield, Richard L.; Carlsten, Bruce E.; Young, Lloyd M.

    1994-01-01

    A compact high brightness linear accelerator is provided for use, e.g., in a free electron laser. The accelerator has a first plurality of acclerating cavities having end walls with four coupling slots for accelerating electrons to high velocities in the absence of quadrupole fields. A second plurality of cavities receives the high velocity electrons for further acceleration, where each of the second cavities has end walls with two coupling slots for acceleration in the absence of dipole fields. The accelerator also includes a first cavity with an extended length to provide for phase matching the electron beam along the accelerating cavities. A solenoid is provided about the photocathode that emits the electons, where the solenoid is configured to provide a substantially uniform magnetic field over the photocathode surface to minimize emittance of the electons as the electrons enter the first cavity.

  7. High brightness electron accelerator

    SciTech Connect

    Sheffield, R.L.; Carlsten, B.E.; Young, L.M.

    1992-12-31

    A compact high brightness linear accelerator is provided for use, e.g., in a free electron laser. The accelerator has a first plurality of acclerating cavities having end walls with four coupling slots for accelerating electrons to high velocities in the absence of quadrupole fields. A second plurality of cavities receives the high velocity electrons for further acceleration, where each of the second cavities has end walls with two coupling slots for acceleration in the absence of dipole fields. The accelerator also includes a first cavity with an extended length to provide for phase matching the electron beam along the accelerating cavities. A solenoid is provided about the photocathode that emits the electrons, where the solenoid is configured to provide a substantially uniform magnetic field over the photocathode surface to minimize emittance of the electrons as the electrons enter the first cavity.

  8. Luminescence in Sulfides: A Rich History and a Bright Future

    PubMed Central

    Smet, Philippe F.; Moreels, Iwan; Hens, Zeger; Poelman, Dirk

    2010-01-01

    Sulfide-based luminescent materials have attracted a lot of attention for a wide range of photo-, cathodo- and electroluminescent applications. Upon doping with Ce3+ and Eu2+, the luminescence can be varied over the entire visible region by appropriately choosing the composition of the sulfide host. Main application areas are flat panel displays based on thin film electroluminescence, field emission displays and ZnS-based powder electroluminescence for backlights. For these applications, special attention is given to BaAl2S4:Eu, ZnS:Mn and ZnS:Cu. Recently, sulfide materials have regained interest due to their ability (in contrast to oxide materials) to provide a broad band, Eu2+-based red emission for use as a color conversion material in white-light emitting diodes (LEDs). The potential application of rare-earth doped binary alkaline-earth sulfides, like CaS and SrS, thiogallates, thioaluminates and thiosilicates as conversion phosphors is discussed. Finally, this review concludes with the size-dependent luminescence in intrinsic colloidal quantum dots like PbS and CdS, and with the luminescence in doped nanoparticles.

  9. SILICA-RICH BRIGHT DEBRIS DISK AROUND HD 15407A

    SciTech Connect

    Fujiwara, Hideaki; Onaka, Takashi; Yamashita, Takuya; Takeda, Yoichi; Ishihara, Daisuke; Kataza, Hirokazu; Murakami, Hiroshi; Fukagawa, Misato

    2012-04-20

    We report an intriguing debris disk toward the F3V star HD 15407A in which an extremely large amount of warm fine dust ({approx}10{sup -7} M{sub Circled-Plus }) is detected. The dust temperature is derived as {approx}500-600 K and the location of the debris dust is estimated as 0.6-1.0 AU from the central star, a terrestrial planet region. The fractional luminosity of the debris disk is {approx}0.005, which is much larger than those predicted by steady-state models of the debris disk produced by planetesimal collisions. The mid-infrared spectrum obtained by Spitzer indicates the presence of abundant {mu}m-sized silica dust, suggesting that the dust comes from the surface layer of differentiated large rocky bodies and might be trapped around the star.

  10. Bright Comet ISON

    NASA Image and Video Library

    2017-09-27

    Comet ISON shines brightly in this image taken on the morning of 19 Nov. 2013. This is a 10-second exposure taken with the Marshall Space Flight Center 20" telescope in New Mexico. The camera there is black and white, but the smaller field of view allows for a better "zoom in" on the comet's coma, which is essentially the head of the comet. Credit: NASA/MSFC/MEO/Cameron McCarty -------- More details on Comet ISON: Comet ISON began its trip from the Oort cloud region of our solar system and is now travelling toward the sun. The comet will reach its closest approach to the sun on Thanksgiving Day -- 28 Nov 2013 -- skimming just 730,000 miles above the sun's surface. If it comes around the sun without breaking up, the comet will be visible in the Northern Hemisphere with the naked eye, and from what we see now, ISON is predicted to be a particularly bright and beautiful comet. Catalogued as C/2012 S1, Comet ISON was first spotted 585 million miles away in September 2012. This is ISON's very first trip around the sun, which means it is still made of pristine matter from the earliest days of the solar system’s formation, its top layers never having been lost by a trip near the sun. Comet ISON is, like all comets, a dirty snowball made up of dust and frozen gases like water, ammonia, methane and carbon dioxide -- some of the fundamental building blocks that scientists believe led to the formation of the planets 4.5 billion years ago. NASA has been using a vast fleet of spacecraft, instruments, and space- and Earth-based telescope, in order to learn more about this time capsule from when the solar system first formed. The journey along the way for such a sun-grazing comet can be dangerous. A giant ejection of solar material from the sun could rip its tail off. Before it reaches Mars -- at some 230 million miles away from the sun -- the radiation of the sun begins to boil its water, the first step toward breaking apart. And, if it survives all this, the intense radiation

  11. How Bright Is the Sun?

    ERIC Educational Resources Information Center

    Berr, Stephen

    1991-01-01

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

  12. Bright Basin on Tethys

    NASA Image and Video Library

    2015-07-27

    With the expanded range of colors visible to Cassini's cameras, differences in materials and their textures become apparent that are subtle or unseen in natural color views. Here, the giant impact basin Odysseus on Saturn's moon Tethys stands out brightly from the rest of the illuminated icy crescent. This distinct coloration may result from differences in either the composition or structure of the terrain exposed by the giant impact. Odysseus (280 miles, or 450 kilometers, across) is one of the largest impact craters on Saturn's icy moons, and may have significantly altered the geologic history of Tethys. Tethys' dark side (at right) is faintly illuminated by reflected light from Saturn. Images taken using ultraviolet, green and infrared spectral filters were combined to create this color view. North on Tethys (660 miles or 1,062 kilometers across) is up in this view. The view was acquired on May 9, 2015 at a distance of approximately 186,000 miles (300,000 kilometers) from Tethys. Image scale is 1.1 mile (1.8 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA18329

  13. Go with the (Bright) Flow

    NASA Image and Video Library

    2017-09-18

    NASA's Mars Reconnaissance Orbiter observes many slopes in the middle latitudes of Mars showing icy flows or glaciers. The region shown here, in the south-facing slope of a crater, is unusual because the flows have bright highlights. The color and brightness variations are likely due to surface coatings of bright dust and dark sand. There is no evidence that these flows are currently active, but they may have been active only millions of years ago. These flows may well contain ice today in their interiors, as confirmed in places by the subsurface radar experiment on MRO. https://photojournal.jpl.nasa.gov/catalog/PIA21953

  14. Bright solitons in non-equilibrium coherent quantum matter

    PubMed Central

    Pinsker, F.; Flayac, H.

    2016-01-01

    We theoretically demonstrate a mechanism for bright soliton generation in spinor non-equilibrium Bose–Einstein condensates made of atoms or quasi-particles such as polaritons in semiconductor microcavities. We give analytical expressions for bright (half) solitons as minimizing functions of a generalized non-conservative Lagrangian elucidating the unique features of inter and intra-competition in non-equilibrium systems. The analytical results are supported by a detailed numerical analysis that further shows the rich soliton dynamics inferred by their instability and mutual cross-interactions. PMID:26997892

  15. Oxygen abundances in low surface-brightness galaxies

    NASA Technical Reports Server (NTRS)

    Roennback, Jari

    1993-01-01

    Recent theories predict that some protogalaxies, in low-density environments of the field, are contracting and interacting so slowly that global star formation can be delayed until today. These systems should be gas rich and have low surface-brightness. Blue compact galaxies (BCG's) and other compact HII region galaxies currently experiencing a burst of star formation are good candidates of truly young galaxies (in the sense that global star formation recently has been initiated). If they really are young, they ought to have a recent phase when their brightness was much lower than in the bursting phase. No claims of observations of such proto-BCG's exist. Observations of galaxies in their juvenile phases would undoubtedly be of great interest, e.g. the determination of the primordial helium abundance would improve. A proper place to search for young nearby galaxies could be among blue low surface-brightness galaxies (BLSBG's) in the local field. The study of low surface-brightness galaxies (LSBG's) as a group began relatively recently. They are galaxies with extraordinary properties both as individuals and as a group. A few years ago we started an optical study of a sample of BLSBG's selected from the ESO/Uppsala catalogue. Results of spectroscopic observations obtained on a subsample - 8 galaxies - of our selection are reported. The HII region oxygen chemical abundances and its relation to the blue absolute magnitude and surface-brightness is investigated.

  16. The UV-Bright Stars of Omega Centauri

    NASA Astrophysics Data System (ADS)

    Landsman, Wayne B.

    During the first flight of the ASTRO observatory in 1990 December, we obtained a 1620 A image of the globular cluster Omega Centauri using the Ultraviolet Imaging Telescope (UIT). This image revealed that Omega Cen contains a rich population of "UV-bright" stars. We have previously obtained IUE spectra of six UV-bright stars discovered on the UIT image and have found a variety of spectra probably indicative of different evolutionary states. Two stars (ROA 5342 and Dk 3873) have sdO spectra indicative of very high temperatures, while the two core UV-bright stars have spectra similar to main-sequence B stars. Only one star (ROA 3596) appears have the luminosity expected of a classical post-AGB star. We now propose to obtain IUE low-dispersion spectra of four additional UV bright stars in Omega Cen. Three of the stars (UIT-151, UIT-1435 and Dickens 3089) are known from comparison of UIT and ground-based photometry to be quite hot (>> 20000 K) although such broad-band photometry can only set a lower limit on their effective temperature. We will use the IUE spectra to determine the effective temperature and luminosity of these stars, in order to help determine their evolutionary status. Our combined survey of 11 UV-bright stars in a single cluster should yield insights concerning the late evolution of low mass stars, and may provide clues to the origin of the ultraviolet light in elliptical galaxies.

  17. High brightness picosecond electron gun

    SciTech Connect

    Merano, M.; Collin, S.; Renucci, P.; Gatri, M.; Sonderegger, S.; Crottini, A.; Ganiere, J.D.; Deveaud, B.

    2005-08-15

    We have developed a high brightness picosecond electron gun. We have used it to replace the thermionic electron gun of a commercial scanning electron microscope (SEM) in order to perform time-resolved cathodoluminescence experiments. Picosecond electron pulses are produced, at a repetition rate of 80.7 MHz, by femtosecond mode-locked laser pulses focused on a metal photocathode. This system has a normalized axial brightness of 93 A/cm{sup 2} sr kV, allowing for a spatial resolution of 50 nm in the secondary electron imaging mode of the SEM. The temporal width of the electron pulse is 12 ps.

  18. In Situ Mosaic Brightness Correction

    NASA Technical Reports Server (NTRS)

    Deen, Robert G.; Lorre, Jean J.

    2012-01-01

    In situ missions typically have pointable, mast-mounted cameras, which are capable of taking panoramic mosaics comprised of many individual frames. These frames are mosaicked together. While the mosaic software applies radiometric correction to the images, in many cases brightness/contrast seams still exist between frames. This is largely due to errors in the radiometric correction, and the absence of correction for photometric effects in the mosaic processing chain. The software analyzes the overlaps between adjacent frames in the mosaic and determines correction factors for each image in an attempt to reduce or eliminate these brightness seams.

  19. Absolute brightness of fluorescent microspheres.

    PubMed

    Finger, Isaac; Phillips, Scott; Mobley, Elizabeth; Tucker, Robert; Hess, Henry

    2009-02-07

    The absolute brightness of fluorescent particles, such as dye-containing nano- and microspheres or quantum dots, is a critical design parameter for many applications relying on fluorescence detection. The absolute brightness, defined as the ratio of radiant intensity of emission to illumination intensity of excitation, of nile-red fluorescent microspheres with a 1 micrometre diameter is measured to be 4.2 +/- 1 x 10(-16) m(2)/sr, and the implications for the design of kinesin motor protein-powered "smart dust" devices and the remote detection of fluorescence are discussed.

  20. Bright Beginnings. WWC Intervention Report

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2009

    2009-01-01

    Bright Beginnings is an early childhood curriculum, based in part on High/Scope[R] and Creative Curriculum[R], with an additional emphasis on literacy skills. The curriculum consists of nine thematic units designed to enhance children's cognitive, social, emotional, and physical development, and each unit includes concept maps, literacy lessons,…

  1. Network based sky Brightness Monitor

    NASA Astrophysics Data System (ADS)

    McKenna, Dan; Pulvermacher, R.; Davis, D. R.

    2009-01-01

    We have developed and are currently testing an autonomous 2 channel photometer designed to measure the night sky brightness in the visual wavelengths over a multi-year campaign. The photometer uses a robust silicon sensor filtered with Hoya CM500 glass. The Sky brightness is measured every minute at two elevation angles typically zenith and 20 degrees to monitor brightness and transparency. The Sky Brightness monitor consists of two units, the remote photometer and a network interface. Currently these devices use 2.4 Ghz transceivers with a free space range of 100 meters. The remote unit is battery powered with day time recharging using a solar panel. Data received by the network interface transmits data via standard POP Email protocol. A second version is under development for radio sensitive areas using an optical fiber for data transmission. We will present the current comparison with the National Park Service sky monitoring camera. We will also discuss the calibration methods used for standardization and temperature compensation. This system is expected to be deployed in the next year and be operated by the International Dark Sky Association SKYMONITOR project.

  2. Bright Spot Locations on Ceres

    NASA Image and Video Library

    2015-12-10

    This map of Ceres, made from images taken by NASA's Dawn spacecraft, shows the locations of about 130 bright areas across the dwarf planet's surface, highlighted in blue. Most of these bright areas are associated with craters. Three insets zoom in on a few areas of interest. Occator Crater, containing the brightest area on Ceres, is shown at top left; Oxo Crater, the second-brightest feature on Ceres, is at top right. In a paper published in the Dec. 10, 2015, issue the journal Nature, Dawn mission scientists identify what they believe to be diffuse hazes at both Occator and Oxo. They believe the hazes appear when the sun shines on these craters, possibly from the sublimation of ice. A typical Ceres crater with bright material that does not appear to have remaining ice is shown at bottom. The bright material in this crater and others appears to originate from mineral salts that may have once been mixed with water ice, but dried up over time, scientists wrote in the same paper. http://photojournal.jpl.nasa.gov/catalog/PIA20183

  3. RICH MAPS

    EPA Science Inventory

    Michael Goodchild recently gave eight reasons why traditional maps are limited as communication devices, and how interactive internet mapping can overcome these limitations. In the past, many authorities in cartography, from Jenks to Bertin, have emphasized the importance of sim...

  4. RICH MAPS

    EPA Science Inventory

    Michael Goodchild recently gave eight reasons why traditional maps are limited as communication devices, and how interactive internet mapping can overcome these limitations. In the past, many authorities in cartography, from Jenks to Bertin, have emphasized the importance of sim...

  5. CONSECUTIVE BRIGHT PULSES IN THE VELA PULSAR

    SciTech Connect

    Palfreyman, Jim L.; Dickey, John M.; Hotan, Claire E.; Hotan, Aidan W.; Young, Timothy G.

    2011-07-01

    We report on the discovery of consecutive bright radio pulses from the Vela pulsar, a new phenomenon that may lead to a greater understanding of the pulsar emission mechanism. This results from a total of 345 hr worth of observations of the Vela pulsar using the University of Tasmania's 26 m radio telescope to study the frequency and statistics of abnormally bright pulses and sub-pulses. The bright pulses show a tendency to appear consecutively. The observations found two groups of six consecutive bright pulses and many groups of two to five bright pulses in a row. The strong radio emission process that produces the six bright pulses lasts between 0.4 and 0.6 s. The numbers of bright pulses in sequence far exceed what would be expected if individual bright pulses were independent random events. Consecutive bright pulses must be generated by an emission process that is long lived relative to the rotation period of the neutron star.

  6. High-Brightness Injector Modeling

    SciTech Connect

    Lewellen, John W.

    2004-12-07

    There are many aspects to the successful conception, design, fabrication, and operation of high-brightness electron beam sources. Accurate and efficient modeling of the injector are critical to all phases of the process, from evaluating initial ideas to successful diagnosis of problems during routine operation. The basic modeling tasks will vary from design to design, according to the basic nature of the injector (dc, rf, hybrid, etc.), the type of cathode used (thermionic, photo, field emitter, etc.), and 'macro' factors such as average beam current and duty factor, as well as the usual list of desired beam properties. The injector designer must be at least aware of, if not proficient at addressing, the multitude of issues that arise from these considerations; and, as high-brightness injectors continue to move out of the laboratory, the number of such issues will continue to expand.

  7. High-brightness injector modeling.

    SciTech Connect

    Lewellen, J. W.; Accelerator Systems Division

    2004-01-01

    There are many aspects to the successful conception, design, fabrication, and operation of high-brightness electron beam sources. Accurate and efficient modeling of the injector are critical to all phases of the process, from evaluating initial ideas to successful diagnosis of problems during routine operation. The basic modeling tasks will vary from design to design, according to the basic nature of the injector (dc, rf, hybrid, etc.), the type of cathode used (thermionic, photo, field emitter, etc.), and 'macro' factors such as average beam current and duty factor, as well as the usual list of desired beam properties. The injector designer must be at least aware of, if not proficient at addressing, the multitude of issues that arise from these considerations; and, as high-brightness injectors continue to move out of the laboratory, the number of such issues will continue to expand.

  8. Brightness-equalized quantum dots

    PubMed Central

    Lim, Sung Jun; Zahid, Mohammad U.; Le, Phuong; Ma, Liang; Entenberg, David; Harney, Allison S.; Condeelis, John; Smith, Andrew M.

    2015-01-01

    As molecular labels for cells and tissues, fluorescent probes have shaped our understanding of biological structures and processes. However, their capacity for quantitative analysis is limited because photon emission rates from multicolour fluorophores are dissimilar, unstable and often unpredictable, which obscures correlations between measured fluorescence and molecular concentration. Here we introduce a new class of light-emitting quantum dots with tunable and equalized fluorescence brightness across a broad range of colours. The key feature is independent tunability of emission wavelength, extinction coefficient and quantum yield through distinct structural domains in the nanocrystal. Precise tuning eliminates a 100-fold red-to-green brightness mismatch of size-tuned quantum dots at the ensemble and single-particle levels, which substantially improves quantitative imaging accuracy in biological tissue. We anticipate that these materials engineering principles will vastly expand the optical engineering landscape of fluorescent probes, facilitate quantitative multicolour imaging in living tissue and improve colour tuning in light-emitting devices. PMID:26437175

  9. Low-brightness quantum radar

    NASA Astrophysics Data System (ADS)

    Lanzagorta, Marco

    2015-05-01

    One of the major scientific thrusts from recent years has been to try to harness quantum phenomena to dramatically increase the performance of a wide variety of classical information processing devices. These advances in quantum information science have had a considerable impact on the development of standoff sensors such as quantum radar. In this paper we analyze the theoretical performance of low-brightness quantum radar that uses entangled photon states. We use the detection error probability as a measure of sensing performance and the interception error probability as a measure of stealthiness. We compare the performance of quantum radar against a coherent light sensor (such as lidar) and classical radar. In particular, we restrict our analysis to the performance of low-brightness standoff sensors operating in a noisy environment. We show that, compared to the two classical standoff sensing devices, quantum radar is stealthier, more resilient to jamming, and more accurate for the detection of low reflectivity targets.

  10. Brightness-equalized quantum dots.

    PubMed

    Lim, Sung Jun; Zahid, Mohammad U; Le, Phuong; Ma, Liang; Entenberg, David; Harney, Allison S; Condeelis, John; Smith, Andrew M

    2015-10-05

    As molecular labels for cells and tissues, fluorescent probes have shaped our understanding of biological structures and processes. However, their capacity for quantitative analysis is limited because photon emission rates from multicolour fluorophores are dissimilar, unstable and often unpredictable, which obscures correlations between measured fluorescence and molecular concentration. Here we introduce a new class of light-emitting quantum dots with tunable and equalized fluorescence brightness across a broad range of colours. The key feature is independent tunability of emission wavelength, extinction coefficient and quantum yield through distinct structural domains in the nanocrystal. Precise tuning eliminates a 100-fold red-to-green brightness mismatch of size-tuned quantum dots at the ensemble and single-particle levels, which substantially improves quantitative imaging accuracy in biological tissue. We anticipate that these materials engineering principles will vastly expand the optical engineering landscape of fluorescent probes, facilitate quantitative multicolour imaging in living tissue and improve colour tuning in light-emitting devices.

  11. Bright tunable ultraviolet squeezed light.

    PubMed

    Bell, A S; Riis, E; Ferguson, A I

    1997-04-15

    We have produced bright tunable squeezed light by second-harmonic generation in a singly resonant cavity. We have investigated the effect of input coupling and fundamental power on the squeezing. Up to 400 mW of continuous-wave mode-locked tunable squeezed light was produced at wavelengths as short as 389 nm, and more than 1.5 dB of squeezing was inferred.

  12. Iapetus Bright and Dark Terrains

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Saturn's outermost large moon, Iapetus, has a bright, heavily cratered icy terrain and a dark terrain, as shown in this Voyager 2 image taken on August 22, 1981. Amazingly, the dark material covers precisely the side of Iapetus that leads in the direction of orbital motion around Saturn (except for the poles), whereas the bright material occurs on the trailing hemisphere and at the poles. The bright terrain is made of dirty ice, and the dark terrain is surfaced by carbonaceous molecules, according to measurements made with Earth-based telescopes. Iapetus' dark hemisphere has been likened to tar or asphalt and is so dark that no details within this terrain were visible to Voyager 2. The bright icy hemisphere, likened to dirty snow, shows many large impact craters. The closest approach by Voyager 2 to Iapetus was a relatively distant 600,000 miles, so that our best images, such as this, have a resolution of about 12 miles. The dark material is made of organic substances, probably including poisonous cyano compounds such as frozen hydrogen cyanide polymers. Though we know a little about the dark terrain's chemical nature, we do not understand its origin. Two theories have been developed, but neither is fully satisfactory--(1) the dark material may be organic dust knocked off the small neighboring satellite Phoebe and 'painted' onto the leading side of Iapetus as the dust spirals toward Saturn and Iapetus hurtles through the tenuous dust cloud, or (2) the dark material may be made of icy-cold carbonaceous 'cryovolcanic' lavas that were erupted from Iapetus' interior and then blackened by solar radiation, charged particles, and cosmic rays. A determination of the actual cause, as well as discovery of any other geologic features smaller than 12 miles across, awaits the Cassini Saturn orbiter to arrive in 2004.

  13. Iapetus Bright and Dark Terrains

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Saturn's outermost large moon, Iapetus, has a bright, heavily cratered icy terrain and a dark terrain, as shown in this Voyager 2 image taken on August 22, 1981. Amazingly, the dark material covers precisely the side of Iapetus that leads in the direction of orbital motion around Saturn (except for the poles), whereas the bright material occurs on the trailing hemisphere and at the poles. The bright terrain is made of dirty ice, and the dark terrain is surfaced by carbonaceous molecules, according to measurements made with Earth-based telescopes. Iapetus' dark hemisphere has been likened to tar or asphalt and is so dark that no details within this terrain were visible to Voyager 2. The bright icy hemisphere, likened to dirty snow, shows many large impact craters. The closest approach by Voyager 2 to Iapetus was a relatively distant 600,000 miles, so that our best images, such as this, have a resolution of about 12 miles. The dark material is made of organic substances, probably including poisonous cyano compounds such as frozen hydrogen cyanide polymers. Though we know a little about the dark terrain's chemical nature, we do not understand its origin. Two theories have been developed, but neither is fully satisfactory--(1) the dark material may be organic dust knocked off the small neighboring satellite Phoebe and 'painted' onto the leading side of Iapetus as the dust spirals toward Saturn and Iapetus hurtles through the tenuous dust cloud, or (2) the dark material may be made of icy-cold carbonaceous 'cryovolcanic' lavas that were erupted from Iapetus' interior and then blackened by solar radiation, charged particles, and cosmic rays. A determination of the actual cause, as well as discovery of any other geologic features smaller than 12 miles across, awaits the Cassini Saturn orbiter to arrive in 2004.

  14. LSST Site: Sky Brightness Data

    NASA Astrophysics Data System (ADS)

    Burke, Jamison; Claver, Charles

    2015-01-01

    The Large Synoptic Survey Telescope (LSST) is an upcoming robotic survey telescope. At the telescope site on Cerro Pachon in Chile there are currently three photodiodes and a Canon camera with a fisheye lens, and both the photodiodes and Canon monitor the night sky continuously. The NIST-calibrated photodiodes directly measure the flux from the sky, and the sky brightness can also be obtained from the Canon images via digital aperture photometry. Organizing and combining the two data sets gives nightly information of the development of sky brightness across a swath of the electromagnetic spectrum, from blue to near infrared light, and this is useful for accurately predicting the performance of the LSST. It also provides data for models of moonlight and twilight sky brightness. Code to accomplish this organization and combination was successfully written in Python, but due to the backlog of data not all of the nights were processed by the end of the summer.Burke was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation Research Experiences for Undergraduates Program (AST-1262829).

  15. High-brightness rf linear accelerators

    SciTech Connect

    Jameson, R.A.

    1986-01-01

    The issue of high brightness and its ramifications in linacs driven by radio-frequency fields is discussed. A history of the RF linacs is reviewed briefly. Some current applications are then examined that are driving progress in RF linacs. The physics affecting the brightness of RF linacs is then discussed, followed by the economic feasibility of higher brightness machines. (LEW)

  16. Photometric monitoring of bright supernovae

    NASA Astrophysics Data System (ADS)

    Tsvetkov, D. Yu.; Pavlyuk, N. N.; Volkov, I. M.; Shugarov, S. Yu.

    2014-03-01

    The program of CCD photometric monitoring of bright supernovae (SNe) is carried out at 0.4 — 1.0 meter telescopes of the Sternberg Astronomical Institute, Crimean Astrophysical Observatory and Stará Lesná Observatory since 1998. We have observed more than 250 SNe of different types. We present the results of observations of SNe Ia 2003du, 2009nr and 2011fe, type IIb SNe 2008ax, 2011dh, type II SNe 2004ek and 2005kd and discuss physical parameters of the explosions. %

  17. Exceptionally bright, compact starburst nucleus

    SciTech Connect

    Margon, B.; Anderson, S.F.; Mateo, M.; Fich, M.; Massey, P.

    1988-11-01

    Observations are reported of a remarkably bright (V about 13) starburst nucleus, 0833 + 652, which has been detected at radio, infrared, optical, ultraviolet, and X-ray wavelengths. Despite an observed flux at each of these wavelengths which is comparable to that of NGC 7714, often considered the 'prototypical' example of the starburst phenomenon, 0833 + 652 appears to be a previously uncataloged object. Its ease of detectability throughout the electromagnetic spectrum should make it useful for a variety of problems in the study of compact emission-line galaxies. 30 references.

  18. High brightness beams and applications

    SciTech Connect

    Sheffield, R.L.

    1995-09-01

    This paper describes the present research on attaining intense bright electron beams. Thermionic systems are briefly covered. Recent and past results from the photoinjector programs are given. The performance advantages and difficulties presently faced by researchers using photoinjectors is discussed. The progress that has been made in photocathode materials, both in lifetime and quantum efficiency, is covered. Finally, a discussion of emittance measurements of photoinjector systems and how the measurement is complicated by the non-thermal nature of the electron beam is presented.

  19. The Nutritional Facts of Bamboo Shoots and Their Usage as Important Traditional Foods of Northeast India

    PubMed Central

    Nongdam, P.; Tikendra, Leimapokpam

    2014-01-01

    Bamboo shoots are considered as one of the useful health foods because of their rich contents of proteins, carbohydrates, vitamins, fibres, and minerals and very low fat. Though bamboo shoots provide lots of health benefits, their consumption is confined mostly to Southeast Asian and East Asian countries. The acceptability of bamboo shoots as popular vegetable crop is very less due to their high pungent smell and bitter acidic taste. The use of bamboo as food in India is mainly restricted to Northeastern part of the country where they form an indispensable part of several traditional speciality dishes. The different ethnic communities take fresh or fermented bamboo shoot as one of most preferred traditional food items. Some of the important bamboo based traditional foods are ushoi, soibum, rep, mesu, eup, ekhung, hirring, and so forth. Bamboo shoots should be properly processed before they are consumed as freshly harvested shoots have high content of toxic cyanogenic glycosides which may pose serious health problems. The prospect of bamboo shoot industry in Northeast India is bright due to its rich genetic resources of bamboos. However, habitat destruction and extensive use of bamboos for food, handicraft, and construction purposes have resulted in severe depletion of natural bamboo resources. This review stresses upon the high nutritive values and health benefits of bamboo shoots and their usage as important traditional foods in Northeast India. The bamboo market potential of the region and use of in vitro plant micropropagation methods as effective means of bamboo conservation are also emphasized in this paper. PMID:27433496

  20. The Nutritional Facts of Bamboo Shoots and Their Usage as Important Traditional Foods of Northeast India.

    PubMed

    Nongdam, P; Tikendra, Leimapokpam

    2014-01-01

    Bamboo shoots are considered as one of the useful health foods because of their rich contents of proteins, carbohydrates, vitamins, fibres, and minerals and very low fat. Though bamboo shoots provide lots of health benefits, their consumption is confined mostly to Southeast Asian and East Asian countries. The acceptability of bamboo shoots as popular vegetable crop is very less due to their high pungent smell and bitter acidic taste. The use of bamboo as food in India is mainly restricted to Northeastern part of the country where they form an indispensable part of several traditional speciality dishes. The different ethnic communities take fresh or fermented bamboo shoot as one of most preferred traditional food items. Some of the important bamboo based traditional foods are ushoi, soibum, rep, mesu, eup, ekhung, hirring, and so forth. Bamboo shoots should be properly processed before they are consumed as freshly harvested shoots have high content of toxic cyanogenic glycosides which may pose serious health problems. The prospect of bamboo shoot industry in Northeast India is bright due to its rich genetic resources of bamboos. However, habitat destruction and extensive use of bamboos for food, handicraft, and construction purposes have resulted in severe depletion of natural bamboo resources. This review stresses upon the high nutritive values and health benefits of bamboo shoots and their usage as important traditional foods in Northeast India. The bamboo market potential of the region and use of in vitro plant micropropagation methods as effective means of bamboo conservation are also emphasized in this paper.

  1. Engineering bright matter-wave solitons of dipolar condensates

    NASA Astrophysics Data System (ADS)

    Edmonds, M. J.; Bland, T.; Doran, R.; Parker, N. G.

    2017-02-01

    We present a comprehensive analysis of the form and interaction of dipolar bright solitons across the full parameter space afforded by dipolar Bose–Einstein condensates, revealing the rich behavior introduced by the non-local nonlinearity. Working within an effective one-dimensional description, we map out the existence of the soliton solutions and show three collisional regimes: free collisions, bound state formation and soliton fusion. Finally, we examine the solitons in their full three-dimensional form through a variational approach; along with regimes of instability to collapse and runaway expansion, we identify regimes of stability which are accessible to current experiments.

  2. Limb displacement and brightness seismology

    NASA Astrophysics Data System (ADS)

    Emilio, Marcelo; Cunnyngham, Ian; Kuhn, Jeff; Mehret, Leandro; Bush, Rock; Scholl, Isabelle

    2015-08-01

    The Helioseismic and Magnetic Imager (HMI) abord the Solar Dynamics Observatory (SDO) has been used to obtain the most sensitive spectrally resolved observation of individual p-modes at the extreme solar limb. Such oscillation observations of the limb displacement and brightness for some spatial and temporal regimes are even competitive in signal-to-noise to full-disk doppler measurements of the p-mode spectrum. Limb measurements of 5-min p-modes, while having many similarities to full-disk doppler observations, have significantly different sensitivities to the solar rotation and the 5-min mode solar atmospheric structure. These may provide information about the solar structure which is complementary to full-disk measurements. In this work we present results from Individual spherical harmonic p-modes that were detected around solar limb with amplitudes at the micro-arcsecond level.

  3. Bright diode laser light source.

    PubMed

    Lassila, Erkki; Hernberg, Rolf

    2006-05-20

    A simplified multiwavelength prototype of an axially symmetric diode laser device based on stacks made of single emitters has been made, and the performance of the device has been demonstrated experimentally. The results verify that kilowatt-level light power can be focused into a circular spot with a 1/e2 diameter of 360 microm, a focal length of 100 mm, and a numerical aperture of 0.24, thus producing an average power density in excess of 10 kW/mm2 and a brightness of 6x10(10) W m-2 sr-1. The experiments also predict that it will be possible to increase these values to more than 60 kW/mm2 and 3x10(11) W m-2 sr-1.

  4. How Bright Can Supernovae Get?

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-04-01

    Supernovae enormous explosions associated with the end of a stars life come in a variety of types with different origins. A new study has examined how the brightest supernovae in the Universe are produced, and what limits might be set on their brightness.Ultra-Luminous ObservationsRecent observations have revealed many ultra-luminous supernovae, which haveenergies that challenge our abilities to explain them usingcurrent supernova models. An especially extreme example is the 2015 discovery of the supernova ASASSN-15lh, which shone with a peak luminosity of ~2*1045 erg/s, nearly a trillion times brighter than the Sun. ASASSN-15lh radiated a whopping ~2*1052 erg in the first four months after its detection.How could a supernova that bright be produced? To explore the answer to that question, Tuguldur Sukhbold and Stan Woosley at University of California, Santa Cruz, have examined the different sources that could produce supernovae and calculated upper limits on the potential luminosities ofeach of these supernova varieties.Explosive ModelsSukhbold and Woosley explore multiple different models for core-collapse supernova explosions, including:Prompt explosionA stars core collapses and immediately explodes.Pair instabilityElectron/positron pair production at a massive stars center leads to core collapse. For high masses, radioactivity can contribute to delayed energy output.Colliding shellsPreviously expelled shells of material around a star collide after the initial explosion, providing additional energy release.MagnetarThe collapsing star forms a magnetar a rapidly rotating neutron star with an incredibly strong magnetic field at its core, which then dumps energy into the supernova ejecta, further brightening the explosion.They then apply these models to different types of stars.Setting the LimitThe authors show that the light curve of ASASSN-15lh (plotted in orange) can be described by a model (black curve) in which a magnetar with an initial spin period of 0.7 ms

  5. Night sky brightness measurement at PERMATApintar observatory

    NASA Astrophysics Data System (ADS)

    Azhar, A. D.; Gopir, G.; Kamil, W. M. A. Wan Mohd; Mohamad, N. S.; Azmi, N. Che

    2016-11-01

    One of the quality parameter of an astronomical site testing is sky brightness. We measure the night sky brightness over PERMATApintar Observatory to obtain the first preliminary sky brightness reading. The measurement is done by using an Unihedron Sky Quality Meter (SQM-LU) with a position pointing zenith. Six measurements have been done during the period of January to March 2016. The measurement is taken between approximately 7 p.m. to 11 p.m. on each of the night. The best (darken) night sky brightness reading is 19.54 mag/arcsec2 obtained on March 11th, 2016. The preliminary average reading of sky brightness is 17.20 mag/arcsec2. Comparison with previous similar measurement for the same type of area (suburban area) shows that our data is within the range of the sky brightness for suburban area, which is 19.5 to 20.7 mag/arcsec2.

  6. Quantum communication with macroscopically bright nonclassical states.

    PubMed

    Usenko, Vladyslav C; Ruppert, Laszlo; Filip, Radim

    2015-11-30

    We analyze homodyne detection of macroscopically bright multimode nonclassical states of light and propose their application in quantum communication. We observe that the homodyne detection is sensitive to a mode-matching of the bright light to the highly intense local oscillator. Unmatched bright modes of light result in additional noise which technically limits detection of Gaussian entanglement at macroscopic level. When the mode-matching is sufficient, we show that multimode quantum key distribution with bright beams is feasible. It finally merges the quantum communication with classical optical technology of visible beams of light.

  7. Loss of Bright/ARID3a Function Promotes Developmental Plasticity

    PubMed Central

    An, Guangyu; Miner, Cathrine A.; Nixon, Jamee C.; Kincade, Paul W.; Bryant, James; Tucker, Philip W.; Webb, Carol F.

    2010-01-01

    Bright (B cell regulator of immunoglobulin heavy chain transcription)/ARID3a, an A+T-rich interaction domain protein, was originally discovered in B lymphocyte lineage cells. However, expression patterns and high lethality levels in knockout mice suggested it had additional functions. Three independent lines of evidence show that functional inhibition of Bright results in increased developmental plasticity. Bright-deficient cells from two mouse models expressed a number of pluripotency-associated gene products, expanded indefinitely and spontaneously differentiated into cells of multiple lineages. Furthermore, direct knockdown of human Bright resulted in colonies capable of expressing multiple lineage markers. These data suggest that repression of this single molecule confers adult somatic cells with new developmental options. PMID:20680960

  8. Bright Times for an Ancient Star

    NASA Astrophysics Data System (ADS)

    Fuhrmann, K.; Chini, R.

    2017-01-01

    Field stars of Population II are among the oldest sources in the Galaxy. Most of their solar-type dwarfs are non-single and, given their extreme age, a significant fraction is accompanied by stellar remnants. Here we report the discovery of the bright F7V star 49 Lib as a massive and very metal-rich Population II field blue straggler, along with evidence for a white dwarf as its dark and unseen companion. 49 Lib is known as a relatively fast-rotating, single-lined spectroscopic binary in a 3 year orbit and with an apparent age of about τ ≃ 2.3 Gyr. Its chemistry and kinematics, however, both consistently imply that 49 Lib must be an ancient Population II star at τ ≃ 12 Gyr. With reference to the inclination from the astrometric orbit, leading to a {M}{WD}={0.50}-0.04+0.03 M⊙ low-mass white dwarf, and in view of the {M}{BS}={1.55}-0.13+0.07 M⊙ massive, evolved F-type blue straggler star, we demonstrate that 49 Lib must have been the subject of a mostly conservative mass transfer with a near-equal-mass M ≃ 1.06 + 1.00 M⊙ G-type binary at birth. For its future evolution, we point to the possibility as a progenitor system toward a type Ia supernova. Most importantly, however, we note that the remarkable metal enrichment of 49 Lib at [Mg/H] = +0.23 and [Fe/H] = ‑0.11 has principally very relevant implications for the early epoch when the Milky Way came into being.

  9. Spatial Brightness Perception of Trichromatic Stimuli

    SciTech Connect

    Royer, Michael P.; Houser, Kevin W.

    2012-11-16

    An experiment was conducted to examine the effect of tuning optical radiation on brightness perception for younger (18-25 years of age) and older (50 years of age or older) observers. Participants made forced-choice evaluations of the brightness of a full factorial of stimulus pairs selected from two groups of four metameric stimuli. The large-field stimuli were created by systematically varying either the red or the blue primary of an RGB LED mixture. The results indicate that light stimuli of equal illuminance and chromaticity do not appear equally bright to either younger or older subjects. The rank-order of brightness is not predicted by any current model of human vision or theory of brightness perception including Scotopic to Photopic or Cirtopic to Photopic ratio theory, prime color theory, correlated color temperature, V(λ)-based photometry, color quality metrics, linear brightness models, or color appearance models. Age may affect brightness perception when short-wavelength primaries are used, especially those with a peak wavelength shorter than 450 nm. The results suggest further development of metrics to predict brightness perception is warranted, and that including age as a variable in predictive models may be valuable.

  10. Bright Star Astrometry with URAT

    NASA Astrophysics Data System (ADS)

    Zacharias, N.

    2015-10-01

    The U.S. Naval Observatory Robotic Astrometric Telescope (URAT) is observing the northern sky since April 2012 for an astrometric survey. Multiple overlaps per year are performed in a single bandpass (680-750 nm) using the "redlens" 20 cm aperture astrograph and a mosaic of large CCDs. Besides the regular, deep survey to magnitude 18.5, short exposures with an objective grating are taken to access stars as bright as 3rd magnitude. A brief overview of the program, observing and reductions is given. Positions on the 8 to 20 mas level are obtained of 66,202 Hipparcos stars at current epochs. These are compared to the Hipparcos Catalog to investigate its accuracy. About 20% of the observed Hipparcos stars are found to have inconsistent positions with the Hipparcos Catalog prediction on the 3 sigma level or over (about 75 mas or more discrepant position offsets). Some stars are now seen at an arcsec (or 25 sigma) off their Hipparcos Catalog predicted position.

  11. Brightness alteration with interweaving contours

    PubMed Central

    Roncato, Sergio

    2012-01-01

    Chromatic induction is observed whenever the perceived colour of a target surface shifts towards the hue of a neighbouring surface. Some vivid manifestations may be seen in a white background where thin coloured lines have been drawn (assimilation) or when lines of different colours are collinear (neon effect) or adjacent (watercolour) to each other. This study examines a particular colour induction that manifests in concomitance with an opposite effect of colour saturation (or anti-spread). The two phenomena can be observed when a repetitive pattern is drawn in which outline thin contours intercept wider contours or surfaces, colour spreading appear to fill the surface occupied by surfaces or thick lines whereas the background traversed by thin lines is seen as brighter or filled of a saturated white. These phenomena were first observed by Bozzi (1975) and Kanizsa (1979) in figural conditions that did not allow them to document their conjunction. Here we illustrate various manifestations of this twofold phenomenon and compare its effects with the known effects of brightness and colour induction. Some conjectures on the nature of these effects are discussed. PMID:23483806

  12. Brightness alteration with interweaving contours.

    PubMed

    Roncato, Sergio

    2012-01-01

    Chromatic induction is observed whenever the perceived colour of a target surface shifts towards the hue of a neighbouring surface. Some vivid manifestations may be seen in a white background where thin coloured lines have been drawn (assimilation) or when lines of different colours are collinear (neon effect) or adjacent (watercolour) to each other. This study examines a particular colour induction that manifests in concomitance with an opposite effect of colour saturation (or anti-spread). The two phenomena can be observed when a repetitive pattern is drawn in which outline thin contours intercept wider contours or surfaces, colour spreading appear to fill the surface occupied by surfaces or thick lines whereas the background traversed by thin lines is seen as brighter or filled of a saturated white. These phenomena were first observed by Bozzi (1975) and Kanizsa (1979) in figural conditions that did not allow them to document their conjunction. Here we illustrate various manifestations of this twofold phenomenon and compare its effects with the known effects of brightness and colour induction. Some conjectures on the nature of these effects are discussed.

  13. Cortical processing of a brightness illusion

    PubMed Central

    Roe, Anna Wang; Lu, Haidong D.; Hung, Chou P.

    2005-01-01

    Several brightness illusions indicate that borders can affect the perception of surfaces dramatically. In the Cornsweet illusion, two equiluminant surfaces appear to be different in brightness because of the contrast border between them. Here, we report the existence of cells in monkey visual cortex that respond to such an “illusory” brightness. We find that luminance responsive cells are located in color-activated regions (cytochrome oxidase blobs and bridges) of primary visual cortex (V1), whereas Cornsweet responsive cells are found preferentially in the color-activated regions (thin stripes) of second visual area (V2). This colocalization of brightness and color processing within V1 and V2 suggests a segregation of contour and surface processing in early visual pathways and a hierarchy of brightness information processing from V1 to V2 in monkeys. PMID:15738406

  14. Cell-free measurements of brightness of fluorescently labeled antibodies

    PubMed Central

    Zhou, Haiying; Tourkakis, George; Shi, Dennis; Kim, David M.; Zhang, Hairong; Du, Tommy; Eades, William C.; Berezin, Mikhail Y.

    2017-01-01

    Validation of imaging contrast agents, such as fluorescently labeled imaging antibodies, has been recognized as a critical challenge in clinical and preclinical studies. As the number of applications for imaging antibodies grows, these materials are increasingly being subjected to careful scrutiny. Antibody fluorescent brightness is one of the key parameters that is of critical importance. Direct measurements of the brightness with common spectroscopy methods are challenging, because the fluorescent properties of the imaging antibodies are highly sensitive to the methods of conjugation, degree of labeling, and contamination with free dyes. Traditional methods rely on cell-based assays that lack reproducibility and accuracy. In this manuscript, we present a novel and general approach for measuring the brightness using antibody-avid polystyrene beads and flow cytometry. As compared to a cell-based method, the described technique is rapid, quantitative, and highly reproducible. The proposed method requires less than ten microgram of sample and is applicable for optimizing synthetic conjugation procedures, testing commercial imaging antibodies, and performing high-throughput validation of conjugation procedures. PMID:28150730

  15. Cell-free measurements of brightness of fluorescently labeled antibodies

    NASA Astrophysics Data System (ADS)

    Zhou, Haiying; Tourkakis, George; Shi, Dennis; Kim, David M.; Zhang, Hairong; Du, Tommy; Eades, William C.; Berezin, Mikhail Y.

    2017-02-01

    Validation of imaging contrast agents, such as fluorescently labeled imaging antibodies, has been recognized as a critical challenge in clinical and preclinical studies. As the number of applications for imaging antibodies grows, these materials are increasingly being subjected to careful scrutiny. Antibody fluorescent brightness is one of the key parameters that is of critical importance. Direct measurements of the brightness with common spectroscopy methods are challenging, because the fluorescent properties of the imaging antibodies are highly sensitive to the methods of conjugation, degree of labeling, and contamination with free dyes. Traditional methods rely on cell-based assays that lack reproducibility and accuracy. In this manuscript, we present a novel and general approach for measuring the brightness using antibody-avid polystyrene beads and flow cytometry. As compared to a cell-based method, the described technique is rapid, quantitative, and highly reproducible. The proposed method requires less than ten microgram of sample and is applicable for optimizing synthetic conjugation procedures, testing commercial imaging antibodies, and performing high-throughput validation of conjugation procedures.

  16. Bright Sparks of Our Future!

    NASA Astrophysics Data System (ADS)

    Riordan, Naoimh

    2016-04-01

    My name is Naoimh Riordan and I am the Vice Principal of Rockboro Primary School in Cork City, South of Ireland. I am a full time class primary teacher and I teach 4th class, my students are aged between 9-10 years. My passion for education has developed over the years and grown towards STEM (Science, Technology, Engineering and Mathematics) subjects. I believe these subjects are the way forward for our future. My passion and beliefs are driven by the unique after school programme that I have developed. It is titled "Sparks" coming from the term Bright Sparks. "Sparks" is an after school programme with a difference where the STEM subjects are concentrated on through lessons such as Science, Veterinary Science Computer Animation /Coding, Eco engineering, Robotics, Magical Maths, Chess and Creative Writing. All these subjects are taught through activity based learning and are one-hour long each week for a ten-week term. "Sparks" is fully inclusive and non-selective which gives all students of any level of ability an opportunity to engage into these subjects. "Sparks" is open to all primary students in County Cork. The "Sparks" after school programme is taught by tutors from the different Universities and Colleges in Cork City. It works very well because the tutor brings their knowledge, skills and specialised equipment from their respective universities and in turn the tutor gains invaluable teaching practise, can trial a pilot programme in a chosen STEM subject and gain an insight into what works in the physical classroom.

  17. Bright Streaks and Dark Fans

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The south polar region of Mars is covered every year by a layer of carbon dioxide ice. In a region called the 'cryptic terrain,' the ice is translucent and sunlight can penetrate through the ice to warm the surface below.

    The ice layer sublimates (evaporates) from the bottom. The dark fans of dust seen in this image come from the surface below the layer of ice, carried to the top by gas venting from below. The translucent ice is 'visible' by virtue of the effect it has on the tone of the surface below, which would otherwise have the same color and reflectivity as the fans.

    Bright streaks in this image are fresh frost. The CRISM team has identified the composition of these streaks to be carbon dioxide.

    Observation Geometry Image PSP_003113_0940 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 26-Mar-2007. The complete image is centered at -85.8 degrees latitude, 106.0 degrees East longitude. The range to the target site was 244.9 km (153.0 miles). At this distance the image scale is 49.0 cm/pixel (with 2 x 2 binning) so objects 147 cm across are resolved. The image shown here has been map-projected to 50 cm/pixel . The image was taken at a local Mars time of 06:20 PM and the scene is illuminated from the west with a solar incidence angle of 79 degrees, thus the sun was about 11 degrees above the horizon. At a solar longitude of 207.6 degrees, the season on Mars is Northern Autumn.

  18. Bright Streaks and Dark Fans

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The south polar region of Mars is covered every year by a layer of carbon dioxide ice. In a region called the 'cryptic terrain,' the ice is translucent and sunlight can penetrate through the ice to warm the surface below.

    The ice layer sublimates (evaporates) from the bottom. The dark fans of dust seen in this image come from the surface below the layer of ice, carried to the top by gas venting from below. The translucent ice is 'visible' by virtue of the effect it has on the tone of the surface below, which would otherwise have the same color and reflectivity as the fans.

    Bright streaks in this image are fresh frost. The CRISM team has identified the composition of these streaks to be carbon dioxide.

    Observation Geometry Image PSP_003113_0940 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 26-Mar-2007. The complete image is centered at -85.8 degrees latitude, 106.0 degrees East longitude. The range to the target site was 244.9 km (153.0 miles). At this distance the image scale is 49.0 cm/pixel (with 2 x 2 binning) so objects 147 cm across are resolved. The image shown here has been map-projected to 50 cm/pixel . The image was taken at a local Mars time of 06:20 PM and the scene is illuminated from the west with a solar incidence angle of 79 degrees, thus the sun was about 11 degrees above the horizon. At a solar longitude of 207.6 degrees, the season on Mars is Northern Autumn.

  19. Brightness of the solar F-corona

    NASA Astrophysics Data System (ADS)

    Kimura, Hiroshi; Mann, Ingrid

    1998-06-01

    We discuss our present knowledge about the brightness of the solar F-corona in the wavelength range from the visible to the middle infrared. From the general trend of the observational data, the F-corona is regarded as the continuous extension of the zodiacal light at smaller elongation of the line of sight. A contribution of thermal emission from dust is indicated by the increasing F-coronal brightness in comparison to the solar spectrum towards longer wavelength. As compared with the F-coronal brightness, the polarization and color in the visible regime are not well determined due to the high sensitivity of these quantities to the observational accuracy. Aside from observational problems, our present interpretation of the F-coronal brightness is also limited due to ambiguities in the inversion of the line of sight integral. Nevertheless, the measurements and model calculations of the brightness can be used to deduce some physical properties of dust grains. We show that the hump of the near-infrared brightness at 4 solar radii, which was sometimes observed in the corona, is related rather to the physical properties of dust grains along the line of sight than to the existence of a dust ring as previously discussed. We also show that the appearance or disappearance of the near-infrared peak in the coronal brightness cannot be described in any periodic cycle for each wavelength range.

  20. Galaxy Selection and the Surface Brightness Distribution

    NASA Astrophysics Data System (ADS)

    McGaugh, Stacy S.; Bothun, Gregory D.; Schombert, James M.

    1995-08-01

    Optical surveys for galaxies are biased against the inclusion of low surface brightness (LSB) galaxies. Disney [Nature, 263,573(1976)] suggested that the constancy of disk central surface brightness noticed by Freeman [ApJ, 160,811(1970)] was not a physical result, but instead was an artifact of sample selection. Since LSB galaxies do exist, the pertinent and still controversial issue is if these newly discovered galaxies constitute a significant percentage of the general galaxy population. In this paper, we address this issue by determining the space density of galaxies as a function of disk central surface brightness. Using the physically reasonable assumption (which is motivated by the data) that central surface brightness is independent of disk scale length, we arrive at a distribution which is roughly flat (i.e., approximately equal numbers of galaxies at each surface brightness) faintwards of the Freeman (1970) value. Brightwards of this, we find a sharp decline in the distribution which is analogous to the turn down in the luminosity function at L^*^. An intrinsically sharply peaked "Freeman law" distribution can be completely ruled out, and no Gaussian distribution can fit the data. Low surface brightness galaxies (those with central surface brightness fainter than 22 B mag arcsec^-2^) comprise >~ 1/2 the general galaxy population, so a representative sample of galaxies at z = 0 does not really exist at present since past surveys have been insensitive to this component of the general galaxy population.

  1. Just How Bright Is a Laser?

    ERIC Educational Resources Information Center

    Van Baak, David A.

    1995-01-01

    Attempts to quantify the subjective sensation of brightness of the spot projected by a helium-neon laser and compares this with conventional sources of light. Provides an exercise in using the blackbody radiation formulas. (JRH)

  2. Dark Lakes on a Bright Landscape

    NASA Image and Video Library

    2013-10-23

    Ultracold hydrocarbon lakes and seas dark shapes near the north pole of Saturn moon Titan can be seen embedded in some kind of bright surface material in this infrared mosaic from NASA Cassini mission.

  3. Just How Bright Is a Laser?

    ERIC Educational Resources Information Center

    Van Baak, David A.

    1995-01-01

    Attempts to quantify the subjective sensation of brightness of the spot projected by a helium-neon laser and compares this with conventional sources of light. Provides an exercise in using the blackbody radiation formulas. (JRH)

  4. New Observations of Subarcsecond Photospheric Bright Points

    NASA Technical Reports Server (NTRS)

    Berger, T. E.; Schrijver, C. J.; Shine, R. A.; Tarbell, T. D.; Title, A. M.; Scharmer, G.

    1995-01-01

    We have used an interference filter centered at 4305 A within the bandhead of the CH radical (the 'G band') and real-time image selection at the Swedish Vacuum Solar Telescope on La Palma to produce very high contrast images of subarcsecond photospheric bright points at all locations on the solar disk. During the 6 day period of 1993 September 15-20 we observed active region NOAA 7581 from its appearance on the East limb to a near-disk-center position on September 20. A total of 1804 bright points were selected for analysis from the disk center image using feature extraction image processing techniques. The measured Full Width at Half Maximum (FWHM) distribution of the bright points in the image is lognormal with a modal value of 220 km (0 sec .30) and an average value of 250 km (0 sec .35). The smallest measured bright point diameter is 120 km (0 sec .17) and the largest is 600 km (O sec .69). Approximately 60% of the measured bright points are circular (eccentricity approx. 1.0), the average eccentricity is 1.5, and the maximum eccentricity corresponding to filigree in the image is 6.5. The peak contrast of the measured bright points is normally distributed. The contrast distribution variance is much greater than the measurement accuracy, indicating a large spread in intrinsic bright-point contrast. When referenced to an averaged 'quiet-Sun' area in the image, the modal contrast is 29% and the maximum value is 75%; when referenced to an average intergranular lane brightness in the image, the distribution has a modal value of 61% and a maximum of 119%. The bin-averaged contrast of G-band bright points is constant across the entire measured size range. The measured area of the bright points, corrected for pixelation and selection effects, covers about 1.8% of the total image area. Large pores and micropores occupy an additional 2% of the image area, implying a total area fraction of magnetic proxy features in the image of 3.8%. We discuss the implications of this

  5. New Observations of Subarcsecond Photospheric Bright Points

    NASA Technical Reports Server (NTRS)

    Berger, T. E.; Schrijver, C. J.; Shine, R. A.; Tarbell, T. D.; Title, A. M.; Scharmer, G.

    1995-01-01

    We have used an interference filter centered at 4305 A within the bandhead of the CH radical (the 'G band') and real-time image selection at the Swedish Vacuum Solar Telescope on La Palma to produce very high contrast images of subarcsecond photospheric bright points at all locations on the solar disk. During the 6 day period of 15-20 Sept. 1993 we observed active region NOAA 7581 from its appearance on the East limb to a near-disk-center position on 20 Sept. A total of 1804 bright points were selected for analysis from the disk center image using feature extraction image processing techniques. The measured FWHM distribution of the bright points in the image is lognormal with a modal value of 220 km (0.30 sec) and an average value of 250 km (0.35 sec). The smallest measured bright point diameter is 120 km (0.17 sec) and the largest is 600 km (O.69 sec). Approximately 60% of the measured bright points are circular (eccentricity approx. 1.0), the average eccentricity is 1.5, and the maximum eccentricity corresponding to filigree in the image is 6.5. The peak contrast of the measured bright points is normally distributed. The contrast distribution variance is much greater than the measurement accuracy, indicating a large spread in intrinsic bright-point contrast. When referenced to an averaged 'quiet-Sun' area in the image, the modal contrast is 29% and the maximum value is 75%; when referenced to an average intergranular lane brightness in the image, the distribution has a modal value of 61% and a maximum of 119%. The bin-averaged contrast of G-band bright points is constant across the entire measured size range. The measured area of the bright points, corrected for pixelation and selection effects, covers about 1.8% of the total image area. Large pores and micropores occupy an additional 2% of the image area, implying a total area fraction of magnetic proxy features in the image of 3.8%. We discuss the implications of this area fraction measurement in the context of

  6. Achieving Peak Brightness in an Atom Laser

    SciTech Connect

    Robins, N.P.; Figl, C.; Haine, S.A.; Morrison, A.K.; Jeppesen, M.; Hope, J.J.; Close, J.D.

    2006-04-14

    In this Letter we present experimental results and a simple analytic theory on the first continuous (long pulse) Raman atom laser. We analyze the flux and brightness of a generic two state atom laser with an analytic model that shows excellent agreement with our experiments. We show that, for the same source size, the brightness achievable with a Raman atom laser is at least 3 orders of magnitude greater than achievable in any other demonstrated continuously outcoupled atom laser.

  7. Apparent brightness distribution of GRB host galaxies

    NASA Astrophysics Data System (ADS)

    Bagoly, Zsolt; Racz, Istvan; Gyorgy Balazs, Lajos; Toth, Viktor; Horvath, Istvan

    2015-08-01

    We studied the relationship between the Swift GRB data and the optical brightness of the host galaxy measured by the Keck telescope. We calculated the unbiased distribution of the host's optical brightness by making use the survival analysis. Based on the sample obtained from merging the Swift GRB table and the Keck optical data we studied also the dependence of this distribution on the GRB's data.

  8. Observations and diagnostics in high brightness beams

    NASA Astrophysics Data System (ADS)

    Cianchi, A.; Anania, M. P.; Bisesto, F.; Castellano, M.; Chiadroni, E.; Pompili, R.; Shpakov, V.

    2016-09-01

    The brightness is a figure of merit largely used in the light sources, like FEL (Free Electron Lasers), but it is also fundamental in several other applications, as for instance Compton backscattering sources, beam driven plasma accelerators and THz sources. Advanced diagnostics are essential tools in the development of high brightness beams. 6D electron beam diagnostics will be reviewed with emphasis on emittance measurement.

  9. Red-emission phosphor's brightness deterioration by x-ray and brightness recovery phenomenon by heating.

    PubMed

    Nakamura, Masaaki; Chida, Koichi; Inaba, Yohei; Kobayashi, Ryota; Zuguchi, Masayuki

    2017-06-26

    There are no feasible real-time and direct skin dosimeters for interventional radiology. One would be available if there were x-ray phosphors that had no brightness change caused by x-ray irradiation, but the emission of the Y2O3:Eu, (Y, Gd, Eu)BO3, and YVO4:Eu phosphors investigated in our previous study was reduced by x-ray irradiation. We found that the brightness of those phosphors recovered, and the purpose of this study is to investigate their recovery phenomena. It is expected that more kinds of phosphors could be used in x-ray dosimeters if the brightness changes caused by x-rays are elucidated and prevented. Three kinds of phosphors-Y2O3:Eu, (Y, Gd, Eu)BO3, and YVO4:Eu-were irradiated by x-rays (2 Gy) to reduce their brightness. After the irradiation, brightness changes occurring at room temperature and at 80 °C were investigated. The irradiation reduced the brightness of all the phosphors by 5%-10%, but the brightness of each recovered immediately both at room temperature and at 80 °C. The recovery at 80 °C was faster than that at room temperature, and at both temperatures the recovered brightness remained at 95%-98% of the brightness before the x-ray irradiation. The brightness recovery phenomena of Y2O3:Eu, (Y, Gd, Eu)BO3, and YVO4:Eu phosphors occurring after brightness deterioration due to x-ray irradiation were found to be more significant at 80 °C than at room temperature. More kinds of phosphors could be used in x-ray scintillation dosimeters if the reasons for the brightness changes caused by x-rays were elucidated.

  10. Energy-exchange collisions of dark-bright-bright vector solitons.

    PubMed

    Radhakrishnan, R; Manikandan, N; Aravinthan, K

    2015-12-01

    We find a dark component guiding the practically interesting bright-bright vector one-soliton to two different parametric domains giving rise to different physical situations by constructing a more general form of three-component dark-bright-bright mixed vector one-soliton solution of the generalized Manakov model with nine free real parameters. Moreover our main investigation of the collision dynamics of such mixed vector solitons by constructing the multisoliton solution of the generalized Manakov model with the help of Hirota technique reveals that the dark-bright-bright vector two-soliton supports energy-exchange collision dynamics. In particular the dark component preserves its initial form and the energy-exchange collision property of the bright-bright vector two-soliton solution of the Manakov model during collision. In addition the interactions between bound state dark-bright-bright vector solitons reveal oscillations in their amplitudes. A similar kind of breathing effect was also experimentally observed in the Bose-Einstein condensates. Some possible ways are theoretically suggested not only to control this breathing effect but also to manage the beating, bouncing, jumping, and attraction effects in the collision dynamics of dark-bright-bright vector solitons. The role of multiple free parameters in our solution is examined to define polarization vector, envelope speed, envelope width, envelope amplitude, grayness, and complex modulation of our solution. It is interesting to note that the polarization vector of our mixed vector one-soliton evolves in sphere or hyperboloid depending upon the initial parametric choices.

  11. Bright and Dark Polar Deposits on Mercury: Evidence for Surface Volatiles

    NASA Astrophysics Data System (ADS)

    Neumann, Gregory A.; Cavanaugh, John F.; Sun, Xiaoli; Mazarico, Erwan M.; Smith, David E.; Zuber, Maria T.; Mao, Dandan; Paige, David A.; Solomon, Sean C.; Ernst, Carolyn M.; Barnouin, Olivier S.

    2013-01-01

    Measurements of surface reflectance of permanently shadowed areas near Mercury’s north pole reveal regions of anomalously dark and bright deposits at 1064-nanometer wavelength. These reflectance anomalies are concentrated on poleward-facing slopes and are spatially collocated with areas of high radar backscatter postulated to be the result of near-surface water ice. Correlation of observed reflectance with modeled temperatures indicates that the optically bright regions are consistent with surface water ice, whereas dark regions are consistent with a surface layer of complex organic material that likely overlies buried ice and provides thermal insulation. Impacts of comets or volatile-rich asteroids could have provided both dark and bright deposits.

  12. Microwave Brightness Temperatures of Tilted Convective Systems

    NASA Technical Reports Server (NTRS)

    Hong, Ye; Haferman, Jeffrey L.; Olson, William S.; Kummerow, Christian D.

    1998-01-01

    Aircraft and ground-based radar data from the Tropical Ocean and Global Atmosphere Coupled-Ocean Atmosphere Response Experiment (TOGA COARE) show that convective systems are not always vertical. Instead, many are tilted from vertical. Satellite passive microwave radiometers observe the atmosphere at a viewing angle. For example, the Special Sensor Microwave/Imager (SSM/I) on Defense Meteorological Satellite Program (DMSP) satellites and the Tropical Rainfall Measurement Mission (TRMM) Microwave Imager (TMI) on the TRMM satellite have an incident angle of about 50deg. Thus, the brightness temperature measured from one direction of tilt may be different than that viewed from the opposite direction due to the different optical depth. This paper presents the investigation of passive microwave brightness temperatures of tilted convective systems. To account for the effect of tilt, a 3-D backward Monte Carlo radiative transfer model has been applied to a simple tilted cloud model and a dynamically evolving cloud model to derive the brightness temperature. The radiative transfer results indicate that brightness temperature varies when the viewing angle changes because of the different optical depth. The tilt increases the displacements between high 19 GHz brightness temperature (Tb(sub 19)) due to liquid emission from lower level of cloud and the low 85 GHz brightness temperature (Tb(sub 85)) due to ice scattering from upper level of cloud. As the resolution degrades, the difference of brightness temperature due to the change of viewing angle decreases dramatically. The dislocation between Tb(sub 19) and Tb(sub 85), however, remains prominent.

  13. The Sky Brightness Data Archive (SBDA)

    NASA Astrophysics Data System (ADS)

    Craine, Eric R.; Craine, Erin M.; Craine, Brian L.

    2011-05-01

    Although many astronomers have long been sensitive to issues of light pollution and deteriorating sky quality it is only in recent years that such interest has extended to other groups including, among others, ecologists, health professionals, and urban planners. Issues of light pollution and loss of dark skies are starting to appear in the scientific literature in the context of health and behavior impacts on both human and animal life. Nonetheless, a common deficiency in most such studies is the absence of historical or baseline data against which to compare sky brightness trends and temporal changes. To address this deficiency we have begun to collect a variety of types of quantitative sky brightness data for insertion in an international sky brightness archive that can be accessed for research projects which are dependent upon an understanding of the nature of local light pollution issues. To aid this process we have developed a mobile sky brightness meter which automatically logs sky brightness and observation location. The device can be stationary for long periods of time or can be easily transported for continuous sky brightness measurement from ground vehicles, boats, or aircraft. The sampling rate is typically about 0.25Hz. We present here examples of different modes of sky brightness measurement, various means of displaying and analyzing such data, ways to interpret natural astronomical phenomena apparent in the data, and suggest a number of complementary scientific projects that may capture the interest of both professional and amateur scientists. Finally, we discuss the status of the archive and ways that potential contributors may submit their observations for publication in the archive.

  14. Are supernovae recorded in indigenous astronomical traditions?

    NASA Astrophysics Data System (ADS)

    Hamacher, Duane W.

    2014-07-01

    Novae and supernovae are rare astronomical events that would have had an influence on the skywatching peoples who witnessed them. Although several bright novae/supernovae have been visible during recorded human history, there are many proposed but no confirmed accounts of supernovae in indigenous oral traditions or material culture. Criteria are established for confirming novae/supernovae in oral traditions and material culture, and claims from around the world are discussed to determine if they meet these criteria. Aboriginal Australian traditions are explored for possible descriptions of novae/supernovae. Although representations of supernovae may exist in Aboriginal traditions, there are currently no confirmed accounts of supernovae in Indigenous Australian oral or material traditions.

  15. Richness-based masses of rich and famous galaxy clusters

    NASA Astrophysics Data System (ADS)

    Andreon, S.

    2016-03-01

    We present a catalog of galaxy cluster masses derived by exploiting the tight correlation between mass and richness, i.e., a properly computed number of bright cluster galaxies. The richness definition adopted in this work is properly calibrated, shows a small scatter with mass, and has a known evolution, which means that we can estimate accurate (0.16 dex) masses more precisely than by adopting any other richness estimates or X-ray or SZ-based proxies based on survey data. We measured a few hundred galaxy clusters at 0.05 < z < 0.22 in the low-extinction part of the Sloan Digital Sky Survey footprint that are in the 2015 catalog of Planck-detected clusters, that have a known X-ray emission, that are in the Abell catalog, or that are among the most most cited in the literature. Diagnostic plots and direct images of clusters are individually inspected and we improved cluster centers and, when needed, we revised redshifts. Whenever possible, we also checked for indications of contamination from other clusters on the line of sight, and found ten such cases. All this information, with the derived cluster mass values, are included in the distributed value-added cluster catalog of the 275 clusters with a derived mass larger than 1014M⊙. Finally, in a technical appendix we illustrate with Planck clusters how to minimize the sensitivity of comparisons between masses listed in different catalogs to the specific overlapping of the considerd subsamples, a problem recognized but not solved in the literature. Full Table 1 is available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/587/A158A web front-end is available at the URL http://www.brera.mi.astro.it/~andreon/famous.html

  16. Solar Cycle 23 in Coronal Bright Points

    NASA Astrophysics Data System (ADS)

    Sattarov, Isroil; Pevtsov, Alexei A.; Karachik, Nina V.; Sherdanov, Chori T.; Tillaboev, A. M.

    2010-04-01

    We describe an automatic routine to identify coronal bright points (CBPs) and apply this routine to SOHO/EIT observations taken in the 195 Å spectral range during solar cycle 23. We examine the total number of CBPs and its change in the course of this solar cycle. Unlike some other recent studies, we do find a modest ≈30% decrease in the number of CBPs associated with maximum of sunspot activity. Using the maximum brightness of CBPs as a criterion, we separate them on two categories: dim CBPs, associated with areas of a quiet Sun, and bright CBPs, associated with an active Sun. We find that the number of dim coronal bright points decreases at the maximum of sunspot cycle, while the number of bright CBPs increases. The latitudinal distributions suggest that dim CBPs are distributed uniformly over the solar disk. Active Sun CBPs exhibit a well-defined two-hump latitudinal profile suggestive of enhanced production of this type of CBPs in sunspot activity belts. Finally, we investigate the relative role of two mechanisms in cycle variations of CBP number, and conclude that a change in fraction of solar surface occupied by the quiet Sun’s magnetic field is the primary cause, with the visibility effect playing a secondary role.

  17. Plasmonic EIT-like switching in bright-dark-bright plasmon resonators.

    PubMed

    Chen, Junxue; Wang, Pei; Chen, Chuncong; Lu, Yonghua; Ming, Hai; Zhan, Qiwen

    2011-03-28

    In this paper we report the study of the electromagnetically induced transparency (EIT)-like transmission in the bright-dark-bright plasmon resonators. It is demonstrated that the interferences between the dark plasmons excited by two bright plasmon resonators can be controlled by the incident light polarization. The constructive interference strengthens the coupling between the bright and dark resonators, leading to a more prominent EIT-like transparency window of the metamaterial. In contrary, destructive interference suppresses the coupling between the bright and dark resonators, destroying the interference pathway that forms the EIT-like transmission. Based on this observation, the plasmonic EIT switching can be realized by changing the polarization of incident light. This phenomenon may find applications in optical switching and plasmon-based information processing.

  18. A selective deficit in the appreciation and recognition of brightness: brightness agnosia?

    PubMed

    Nijboer, Tanja C W; Nys, Gudrun M S; van der Smagt, Maarten J; de Haan, Edward H F

    2009-01-01

    We report a patient with extensive brain damage in the right hemisphere who demonstrated a severe impairment in the appreciation of brightness. Acuity, contrast sensitivity as well as luminance discrimination were normal, suggesting her brightness impairment is not a mere consequence of low-level sensory impairments. The patient was not able to indicate the darker or the lighter of two grey squares, even though she was able to see that they differed. In addition, she could not indicate whether the lights in a room were switched on or off, nor was she able to differentiate between normal greyscale images and inverted greyscale images. As the patient recognised objects, colours, and shapes correctly, the impairment is specific for brightness. As low-level, sensory processing is normal, this specific deficit in the recognition and appreciation of brightness appears to be of a higher, cognitive level, the level of semantic knowledge. This appears to be the first report of 'brightness agnosia'.

  19. Brightness Discrimination in Budgerigars (Melopsittacus undulatus)

    PubMed Central

    Lind, Olle; Karlsson, Sandra; Kelber, Almut

    2013-01-01

    Birds have excellent spatial acuity and colour vision compared to other vertebrates while spatial contrast sensitivity is relatively poor for unknown reasons. Contrast sensitivity describes the detection of gratings of varying spatial frequency. It is unclear whether bird brightness discrimination between large uniform fields is poor as well. Here we show that budgerigars (Melopsittacus undulatus) need a Michelson contrast of 0.09 to discriminate between large spatially separated achromatic fields in bright light conditions. This is similar to the peak contrast sensitivity of 10.2 (0.098 Michelson contrast) for achromatic grating stimuli established in earlier studies. The brightness discrimination threshold described in Weber fractions is 0.18, which is modest compared to other vertebrates. PMID:23349946

  20. Dark Dunes Over-riding Bright Dunes

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Some martian sand dunes may be more active than others. In this picture, wind has caused the dark and somewhat crescent-shaped dunes to advance toward the lower left. While their movement cannot actually be seen in this April 1998snapshot, the location of their steepest slopes--their slip faces--on their southwestern sides indicates the direction of movement. Oddly, these dark dunes have moved across and partly cover sets of smaller, bright ridges that also formed by wind action.

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image illustrates an intriguing martian 'find.' Strangely, the two dune types have different shapes and a different relative brightness. There are two explanations for the relationship seen here, and neither can be distinguished as 'the answer'--(1) it is possible that the brighter dunes are old and cemented, and represent some ancient wind activity, whereas the dark dunes are modern and are marching across the older, 'fossilized' dune forms, or (2) the bright dunes are composed of grains that are much larger or more dense than those that compose the dark dunes. In the latter scenario, the bright dunes move more slowly and are over-taken by the dark dunes because their grains are harder to transport. An interpretation involving larger or denser grains is consistent with the small size and even-spacing of the bright dunes, as well, but usually on Earth such features occur on the surfaces of larger, finer-grained dunes, not under them. The actual composition of either the bright or dark materials are unknown. This example is located on the floor of an impact crater in western Arabia Terra at 10.7oN, 351.0oW. The picture is illuminated from the right.

  1. Richard Bright and his neurological studies.

    PubMed

    Pearce, J M S

    2009-01-01

    Richard Bright was one of the famous triumvirate of Guy's Hospital physicians in the Victorian era. Remembered for his account of glomerulonephritis (Bright's disease) he also made many important and original contributions to medicine and neurology. These included his work on cortical epileptogenesis, descriptions of simple partial (Jacksonian) seizures, infantile convulsions, and a variety of nervous diseases. Most notable were his reports of neurological studies including papers on traumatic tetanus, syringomyelia, arteries of the brain, contractures of spinal origin, tumours of the base of the brain, and narcolepsy. His career and these contributions are outlined.

  2. Diagnostics for high-brightness beams

    SciTech Connect

    Shafer, R.E.

    1990-01-01

    Special techniques are required for beam diagnostics on high-brightness particle beams. Examples of high-brightness beams include low-emittance proton linacs (either pulsed or CW), electron linacs suitable for free-electron-laser applications, and future linear colliders. Non-interceptive and minimally-interceptive techniques for measuring beam current, position, profile, and transverse and longitudinal emittance will be reviewed. Included will be stripline, wire scanner, laser neutralization, beam-beam scattering, interceptive microgratings, spontaneous emission, optical transition radiation, and other techniques. 24 refs.

  3. Comet brightness parameters: Definition, determination, and correlations

    NASA Technical Reports Server (NTRS)

    Meisel, D. D.; Morris, C. S.

    1976-01-01

    The power-law definition of comet brightness is reviewed and possible systematic influences are discussed that can affect the derivation of m sub o and n values from visual magnitude estimates. A rationale for the Bobrovnikoff aperture correction method is given and it is demonstrated that the Beyer extrafocal method leads to large systematic effects which if uncorrected by an instrumental relationship result in values significantly higher than those derived according to the Bobrovnikoff guidelines. A series of visual brightness parameter sets are presented which have been reduced to the same photometric system. Recommendations are given to insure that future observations are reduced to the same system.

  4. Kinematics of Low Surface Brightness Galaxies

    NASA Astrophysics Data System (ADS)

    Cardullo, A.; Pizzella, A.; Corsini, E. M.; Bertola, F.

    2008-10-01

    We analyzed the kinematic of 12 low surface-brightness (LSB) galaxies to study the correlation between the disk circular velocity V_{c} and the central velocity dispersion of the spheroidal component σ_{0}. This relation has been claimed to be either the same power-law relation tep{buy} or a different linear one tep{piz} with respect to high surface-brightness (HSB) galaxies. We confirm here that LSB and HSB galaxies follow two different linear V_{c}-σ_{0} relations.

  5. A new, bright and hard aluminum surface produced by anodization

    NASA Astrophysics Data System (ADS)

    Hou, Fengyan; Hu, Bo; Tay, See Leng; Wang, Yuxin; Xiong, Chao; Gao, Wei

    2017-07-01

    Anodized aluminum (Al) and Al alloys have a wide range of applications. However, certain anodized finishings have relatively low hardness, dull appearance and/or poor corrosion resistance, which limited their applications. In this research, Al was first electropolished in a phosphoric acid-based solution, then anodized in a sulfuric acid-based solution under controlled processing parameters. The anodized specimen was then sealed by two-step sealing method. A systematic study including microstructure, surface morphology, hardness and corrosion resistance of these anodized films has been conducted. Results show that the hardness of this new anodized film was increased by a factor of 10 compared with the pure Al metal. Salt spray corrosion testing also demonstrated the greatly improved corrosion resistance. Unlike the traditional hard anodized Al which presents a dull-colored surface, this newly developed anodized Al alloy possesses a very bright and shiny surface with good hardness and corrosion resistance.

  6. Brightness versus roughness: a multiscale approach

    NASA Astrophysics Data System (ADS)

    Bigerelle, M.; Marteau, J.; Paulin, C.

    2015-03-01

    A link between roughness and brightness is sought for brass specimens that were superfinished, sandblasted and brushed. Only the blasting conditions are varied in order to get different roughness and brightness. First, a relation between roughness and brightness is sought for specimens that were superfinished and sandblasted. The best relation is obtained using the mean height of the motifs, calculated using a low-pass filter and cut-off length equal to 30 μm, with a logarithmic-logarithmic model. Then, the same type of relation is determined after superfinishing sandblasting and brushing. The core material volume Vmc, computed using a high-pass filter with a cut-off length of 60 μm and a linear-logarithmic relationship, gives the best results. A relation between roughness and brightness that is common to both the pre-brushing state and post-brushing state is identified: the best roughness parameter is the arithmetic mean deviation Sa using a high-pass filter with a cut-off of 15 μm, with a logarithmic-logarithmic relationship. Finally, it is shown that the use of these filtering conditions enables us to verify the model of Beckmann and Spizzichino for the examined specimens. This scale corresponds to the end of the fractal regime and is close to the end of the signal correlation.

  7. Scattering amplitudes for dark and bright excitons

    NASA Astrophysics Data System (ADS)

    Shiau, Shiue-Yuan; Combescot, Monique; Combescot, Roland; Dubin, François; Chang, Yia-Chung

    2017-05-01

    Using the composite boson many-body formalism that takes single-exciton states rather than free carrier states as a basis, we derive the integral equation fulfilled by the exciton-exciton effective scattering from which the role of fermion exchanges can be unraveled. For excitons made of (+/-1/2) -spin electrons and (+/-3/2) -spin holes, as in GaAs heterostructures, one major result is that most spin configurations lead to brightness-conserving scatterings with equal amplitude Δ, despite differences in the carrier exchanges involved. A brightness-changing channel also exists when two opposite-spin excitons scatter: dark excitons (2,-2) can end either in the same dark states with an amplitude Δe , or in opposite-spin bright states (1,-1) , with a different amplitude Δo , the number of carrier exchanges involved in these scatterings being even or odd, respectively. Another major result is that these amplitudes are linked by a striking relation, Δ_e+Δ_o=Δ , which has decisive consequence on exciton Bose-Einstein condensation. By using Born values, we show that the exciton condensate can be optically observed through a bright part when excitons have large dipole only, that is, when the electrons and holes are in two well-separated layers, as in current experiments.

  8. Brightness and Darkness as Perceptual Dimensions

    PubMed Central

    Vladusich, Tony; Lucassen, Marcel P; Cornelissen, Frans W

    2007-01-01

    A common-sense assumption concerning visual perception states that brightness and darkness cannot coexist at a given spatial location. One corollary of this assumption is that achromatic colors, or perceived grey shades, are contained in a one-dimensional (1-D) space varying from bright to dark. The results of many previous psychophysical studies suggest, by contrast, that achromatic colors are represented as points in a color space composed of two or more perceptual dimensions. The nature of these perceptual dimensions, however, presently remains unclear. Here we provide direct evidence that brightness and darkness form the dimensions of a two-dimensional (2-D) achromatic color space. This color space may play a role in the representation of object surfaces viewed against natural backgrounds, which simultaneously induce both brightness and darkness signals. Our 2-D model generalizes to the chromatic dimensions of color perception, indicating that redness and greenness (blueness and yellowness) also form perceptual dimensions. Collectively, these findings suggest that human color space is composed of six dimensions, rather than the conventional three. PMID:18237226

  9. Surface brightness measurements for APM galaxies

    NASA Astrophysics Data System (ADS)

    Shao, Z.; Maddox, S. J.; Jones, J. B.; Coles, P.

    2003-01-01

    This paper considers some simple surface brightness (SB) estimates for galaxies in the Automated Plate Measuring machine (APM) catalogue in order to derive homogeneous SB data for a very large sample of faint galaxies. The isophotal magnitude and area are used to estimate the central surface brightness and total magnitude based on the assumption of an exponential SB profile. The SB measurements are corrected for field effects on each UK Schmidt plate and the zero-point of each plate is adjusted to give a uniform sample of SB and total magnitude estimates over the whole survey. Results are obtained for 2.4 million galaxies with blue photographic magnitudes brighter than bJ= 20.5 covering 4300 deg2 in the region of the South Galactic Cap. Almost all galaxies in our sample have central surface brightness in the range 20 to 24 bJ mag arcsec-2. The SB measurements we obtain are compared to previous SB measurements and we find an acceptable level of error of +/-0.2 bJ mag arcsec-2. The distribution of SB profiles is considered for different galaxy morphologies for the bright APM galaxies. We find that early-type galaxies have more centrally concentrated profiles.

  10. AMSR-E/Aqua Gridded Brightness Temperatures

    NASA Astrophysics Data System (ADS)

    Savoie, M.; Brodzik, M. J.; Knowles, K.

    2006-12-01

    Passive microwave brightness temperature data are a major component in many geophysical models and algorithms. For many researchers, a major difficulty in using these data is transforming the satellite swath data into a model-friendly, gridded format. Two new data sets and improvements to a toolkit at the National Snow and Ice Data Center (NSIDC) will help scientists incorporate these data into their research. We have produced "AMSR-E/Aqua Daily EASE-Grid Brightness Temperatures" from the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) instrument aboard NASA's Earth Observing System (EOS) Aqua satellite. This data set will complement and extend NSIDC's existing EASE-grid brightness temperature data sets, with new data beginning June 2002 and continuing throughout the life-cycle of the instrument. Additionally, in order to respond to user demand for quarter-degree data, we are distributing "AMSR-E/Aqua Daily Global Quarter-Degree Gridded Brightness Temperatures" also spanning the AMSR-E time period. Researchers whose needs are not met by the above data sets can create customized grids with our AMSR-E Swath to Grid Toolkit. Recent improvements to the toolkit allow subsetted swath data as input, greatly reducing the initial data volume required to produce customized grids.

  11. Bright Meteor Lights Up Atlanta Skies

    NASA Image and Video Library

    This video shows a very bright meteor that streaked over the skies of Atlanta, Ga., on the night of Aug. 28, 2011. The view is from an all sky camera in Cartersville, Ga., operated by NASA’s Mars...

  12. Simultaneous brightness contrast of foraging Papilio butterflies.

    PubMed

    Kinoshita, Michiyo; Takahashi, Yuki; Arikawa, Kentaro

    2012-05-22

    This study focuses on the sense of brightness in the foraging Japanese yellow swallowtail butterfly, Papilio xuthus. We presented two red discs of different intensity on a grey background to butterflies, and trained them to select one of the discs. They were successfully trained to select either a high intensity or a low intensity disc. The trained butterflies were tested on their ability to perceive brightness in two different protocols: (i) two orange discs of different intensity presented on the same intensity grey background and (ii) two orange discs of the same intensity separately presented on a grey background that was either higher or lower in intensity than the training background. The butterflies trained to high intensity red selected the orange disc of high intensity in protocol 1, and the disc on the background of low intensity grey in protocol 2. We obtained similar results in another set of experiments with purple discs instead of orange discs. The choices of the butterflies trained to low intensity red were opposite to those just described. Taken together, we conclude that Papilio has the ability to learn brightness and darkness of targets independent of colour, and that they have the so-called simultaneous brightness contrast.

  13. Two Views of Vesta Bright and Dark

    NASA Image and Video Library

    2013-09-27

    These two maps of the giant asteroid Vesta show patterns of brightness from NASA Hubble Space Telescope top and NASA Dawn spacecraft bottom. Hubble view is from an orbit around Earth. Dawn went into orbit around Vesta from 2011 to 2012.

  14. Sky brightness during eclipses: a review.

    PubMed

    Silverman, S M; Mullen, E G

    1975-12-01

    This paper is abstracted from the introductory section of "Sky Brightness During Eclipses: A Compendium from the Literature," AFCRL-TR-74-0363, Special Reports 180, Air Force Cambridge Research Laboratories, Hanscom AFB, Massachusetts 01731. This report should be consulted for fuller details and tables.

  15. Venus: A Map of Its Brightness Temperature.

    PubMed

    Murray, B C; Wildey, R L; Westphal, J A

    1963-04-26

    The 200-inch Hale telescope has been used to make high-resolution maps of the brightness temperature of Venus at wavelengths 8 to 14 microns. Resolution of about 1/30 of the disk reveals a general symmetry about the plane of the orbit, no daynight temperature effects, and a transient temperature anomaly in the southern hemisphere.

  16. Brightness of synchrotron radiation from wigglers

    NASA Astrophysics Data System (ADS)

    Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

    2016-01-01

    According to the literature, while calculating the brightness of synchrotron radiation from wigglers, one needs to account for the so-called 'depth-of-field' effects. In fact, the particle beam cross-section varies along the wiggler. It is usually stated that the effective photon source size increases accordingly, while the brightness is reduced. Here we claim that this is a misconception originating from an analysis of the wiggler source based on geometrical arguments, regarded as almost self-evident. According to electrodynamics, depth-of-field effects do not exist: we demonstrate this statement both theoretically and numerically, using a well-known first-principle computer code. This fact shows that under the usually accepted approximations, the description of the wiggler brightness turns out to be inconsistent even qualitatively. Therefore, there is a need for a well-defined procedure for computing the brightness from a wiggler source. We accomplish this task based on the use of a Wigner function formalism. We exemplify this formalism in simple limiting cases. We consider the problem of the calculation of the wiggler source size by means of numerical simulations alone, which play the same role of an experiment. We report a significant numerical disagreement between exact calculations and approximations currently used in the literature.

  17. Simultaneous brightness contrast of foraging Papilio butterflies

    PubMed Central

    Kinoshita, Michiyo; Takahashi, Yuki; Arikawa, Kentaro

    2012-01-01

    This study focuses on the sense of brightness in the foraging Japanese yellow swallowtail butterfly, Papilio xuthus. We presented two red discs of different intensity on a grey background to butterflies, and trained them to select one of the discs. They were successfully trained to select either a high intensity or a low intensity disc. The trained butterflies were tested on their ability to perceive brightness in two different protocols: (i) two orange discs of different intensity presented on the same intensity grey background and (ii) two orange discs of the same intensity separately presented on a grey background that was either higher or lower in intensity than the training background. The butterflies trained to high intensity red selected the orange disc of high intensity in protocol 1, and the disc on the background of low intensity grey in protocol 2. We obtained similar results in another set of experiments with purple discs instead of orange discs. The choices of the butterflies trained to low intensity red were opposite to those just described. Taken together, we conclude that Papilio has the ability to learn brightness and darkness of targets independent of colour, and that they have the so-called simultaneous brightness contrast. PMID:22179808

  18. Effects of tryptophan-rich breakfast and light exposure during the daytime on melatonin secretion at night.

    PubMed

    Fukushige, Haruna; Fukuda, Yumi; Tanaka, Mizuho; Inami, Kaoru; Wada, Kai; Tsumura, Yuki; Kondo, Masayuki; Harada, Tetsuo; Wakamura, Tomoko; Morita, Takeshi

    2014-11-19

    The purpose of the present study is to investigate effects of tryptophan intake and light exposure on melatonin secretion and sleep by modifying tryptophan ingestion at breakfast and light exposure during the daytime, and measuring sleep quality (by using actigraphy and the OSA sleep inventory) and melatonin secretion at night. Thirty three male University students (mean ± SD age: 22 ± 3.1 years) completed the experiments lasting 5 days and 4 nights. The subjects were randomly divided into four groups: Poor*Dim (n = 10), meaning a tryptophan-poor breakfast (55 mg/meal) in the morning and dim light environment (<50 lx) during the daytime; Rich*Dim (n = 7), tryptophan-rich breakfast (476 mg/meal) and dim light environment; Poor*Bright (n = 9), tryptophan-poor breakfast and bright light environment (>5,000 lx); and Rich*Bright (n = 7), tryptophan-rich breakfast and bright light. Saliva melatonin concentrations on the fourth day were significantly lower than on the first day in the Poor*Dim group, whereas they were higher on the fourth day in the Rich*Bright group. Creatinine-adjusted melatonin in urine showed the same direction as saliva melatonin concentrations. These results indicate that the combination of a tryptophan-rich breakfast and bright light exposure during the daytime could promote melatonin secretion at night; further, the observations that the Rich*Bright group had higher melatonin concentrations than the Rich*Dim group, despite no significant differences being observed between the Poor*Dim and Rich*Dim groups nor the Poor*Bright and Rich*Bright groups, suggest that bright light exposure in the daytime is an important contributor to raised melatonin levels in the evening. This study is the first to report the quantitative effects of changed tryptophan intake at breakfast combined with daytime light exposure on melatonin secretion and sleep quality. Evening saliva melatonin secretion changed significantly and indicated that a tryptophan-rich

  19. The nature of solar brightness variations

    NASA Astrophysics Data System (ADS)

    Shapiro, A. I.; Solanki, S. K.; Krivova, N. A.; Cameron, R. H.; Yeo, K. L.; Schmutz, W. K.

    2017-09-01

    Determining the sources of solar brightness variations1,2, often referred to as solar noise3, is important because solar noise limits the detection of solar oscillations3, is one of the drivers of the Earth's climate system4,5 and is a prototype of stellar variability6,7—an important limiting factor for the detection of extrasolar planets. Here, we model the magnetic contribution to solar brightness variability using high-cadence8,9 observations from the Solar Dynamics Observatory (SDO) and the Spectral And Total Irradiance REconstruction (SATIRE)10,11 model. The brightness variations caused by the constantly evolving cellular granulation pattern on the solar surface were computed with the Max Planck Institute for Solar System Research (MPS)/University of Chicago Radiative Magnetohydrodynamics (MURaM)12 code. We found that the surface magnetic field and granulation can together precisely explain solar noise (that is, solar variability excluding oscillations) on timescales from minutes to decades, accounting for all timescales that have so far been resolved or covered by irradiance measurements. We demonstrate that no other sources of variability are required to explain the data. Recent measurements of Sun-like stars by the COnvection ROtation and planetary Transits (CoRoT)13 and Kepler14 missions uncovered brightness variations similar to that of the Sun, but with a much wider variety of patterns15. Our finding that solar brightness variations can be replicated in detail with just two well-known sources will greatly simplify future modelling of existing CoRoT and Kepler as well as anticipated Transiting Exoplanet Survey Satellite16 and PLAnetary Transits and Oscillations of stars (PLATO)17 data.

  20. Cortical brightness adaptation when darkness and brightness produce different dynamical states in the visual cortex

    PubMed Central

    Xing, Dajun; Yeh, Chun-I; Gordon, James; Shapley, Robert M.

    2014-01-01

    Darkness and brightness are very different perceptually. To understand the neural basis for the visual difference, we studied the dynamical states of populations of neurons in macaque primary visual cortex when a spatially uniform area (8° × 8°) of the visual field alternated between black and white. Darkness evoked sustained nerve-impulse spiking in primary visual cortex neurons, but bright stimuli evoked only a transient response. A peak in the local field potential (LFP) γ band (30–80 Hz) occurred during darkness; white-induced LFP fluctuations were of lower amplitude, peaking at 25 Hz. However, the sustained response to white in the evoked LFP was larger than for black. Together with the results on spiking, the LFP results imply that, throughout the stimulus period, bright fields evoked strong net sustained inhibition. Such cortical brightness adaptation can explain many perceptual phenomena: interocular speeding up of dark adaptation, tonic interocular suppression, and interocular masking. PMID:24398523

  1. Cortical brightness adaptation when darkness and brightness produce different dynamical states in the visual cortex.

    PubMed

    Xing, Dajun; Yeh, Chun-I; Gordon, James; Shapley, Robert M

    2014-01-21

    Darkness and brightness are very different perceptually. To understand the neural basis for the visual difference, we studied the dynamical states of populations of neurons in macaque primary visual cortex when a spatially uniform area (8° × 8°) of the visual field alternated between black and white. Darkness evoked sustained nerve-impulse spiking in primary visual cortex neurons, but bright stimuli evoked only a transient response. A peak in the local field potential (LFP) γ band (30-80 Hz) occurred during darkness; white-induced LFP fluctuations were of lower amplitude, peaking at 25 Hz. However, the sustained response to white in the evoked LFP was larger than for black. Together with the results on spiking, the LFP results imply that, throughout the stimulus period, bright fields evoked strong net sustained inhibition. Such cortical brightness adaptation can explain many perceptual phenomena: interocular speeding up of dark adaptation, tonic interocular suppression, and interocular masking.

  2. Intermittent Episodes of Bright Light Suppress Myopia in the Chicken More than Continuous Bright Light

    PubMed Central

    Lan, Weizhong; Feldkaemper, Marita; Schaeffel, Frank

    2014-01-01

    Purpose Bright light has been shown a powerful inhibitor of myopia development in animal models. We studied which temporal patterns of bright light are the most potent in suppressing deprivation myopia in chickens. Methods Eight-day-old chickens wore diffusers over one eye to induce deprivation myopia. A reference group (n = 8) was kept under office-like illuminance (500 lux) at a 10∶14 light∶dark cycle. Episodes of bright light (15 000 lux) were super-imposed on this background as follows. Paradigm I: exposure to constant bright light for either 1 hour (n = 5), 2 hours (n = 5), 5 hours (n = 4) or 10 hours (n = 4). Paradigm II: exposure to repeated cycles of bright light with 50% duty cycle and either 60 minutes (n = 7), 30 minutes (n = 8), 15 minutes (n = 6), 7 minutes (n = 7) or 1 minute (n = 7) periods, provided for 10 hours. Refraction and axial length were measured prior to and immediately after the 5-day experiment. Relative changes were analyzed by paired t-tests, and differences among groups were tested by one-way ANOVA. Results Compared with the reference group, exposure to continuous bright light for 1 or 2 hours every day had no significant protective effect against deprivation myopia. Inhibition of myopia became significant after 5 hours of bright light exposure but extending the duration to 10 hours did not offer an additional benefit. In comparison, repeated cycles of 1∶1 or 7∶7 minutes of bright light enhanced the protective effect against myopia and could fully suppress its development. Conclusions The protective effect of bright light depends on the exposure duration and, to the intermittent form, the frequency cycle. Compared to the saturation effect of continuous bright light, low frequency cycles of bright light (1∶1 min) provided the strongest inhibition effect. However, our quantitative results probably might not be directly translated into humans, but rather need further amendments in clinical

  3. TURBULENT PAIR DISPERSION OF PHOTOSPHERIC BRIGHT POINTS

    SciTech Connect

    Lepreti, F.; Carbone, V.; Capparelli, V.; Vecchio, A.

    2012-11-01

    Observations of solar granulation obtained with the New Solar Telescope of Big Bear Solar Observatory are used to study the turbulent pair dispersion of photospheric bright points in a quiet-Sun area, a coronal hole, and an active region plage. In all the three magnetic environments, it is found that the pair mean-squared separation {Delta}{sup 2}(t) follows a power-law timescaling {Delta}{sup 2}(t) {approx} t {sup {eta}} in the range 10 s {approx}< t {approx}< 400 s. The power-law index is found to be {eta} {approx_equal} 1.5 for all the three investigated regions. It is shown that these results can be explained in the same framework as the classical Batchelor theory, under the hypothesis that the observed range of timescales corresponds to a non-asymptotic regime in which the photospheric bright points keep the memory of their initial separations.

  4. Bright Feature Appears in Titan Kraken Mare

    NASA Image and Video Library

    2014-11-10

    Two Synthetic Aperture Radar (SAR) images from the radar experiment on NASA's Cassini spacecraft show that, between May 2013 and August 2014, a bright feature appeared in Kraken Mare, the largest hydrocarbon sea on Saturn's moon Titan. Researchers think the bright feature is likely representative of something on the hydrocarbon sea's surface, such as waves or floating debris. A similar feature appeared in Ligea Mare, another Titan sea, and was seen to evolve in appearance between 2013 and 2014 (see PIA18430). The image at left was taken on May 23, 2013 at an incidence angle of 56 degrees; the image at right was taken on August 21, 2014 at an incidence angle of 5 degrees. Incidence angle refers to the angle at which the radar beam strikes the surface. http://photojournal.jpl.nasa.gov/catalog/PIA19047

  5. Image mosaic with color and brightness correction

    NASA Astrophysics Data System (ADS)

    Zhao, Yili; Xu, Dan; Pan, Zhigeng

    2004-03-01

    Image mosaic is comprised of building a large field of view from a sequence of smaller images. It can be performed by registering, projective warping, resampling and compositing a serials of images. Due to the many possible factors for color and brightness variations when taking images, it is possible to lead to misalignment and obtain poor stitching result. Despite image mosaic can be manually adjusted using some photo editors like PhotoShop, this is not only tedious but also requires skills, knowledge and experience. Automatic adjustment is therefore desirable. By converting images to lαβ space and applying a special statistical analysis, color and brightness correction can be done automatically and improved image mosaic can be obtained.

  6. Extreme Ultraviolet Explorer Bright Source List

    NASA Technical Reports Server (NTRS)

    Malina, Roger F.; Marshall, Herman L.; Antia, Behram; Christian, Carol A.; Dobson, Carl A.; Finley, David S.; Fruscione, Antonella; Girouard, Forrest R.; Hawkins, Isabel; Jelinsky, Patrick

    1994-01-01

    Initial results from the analysis of the Extreme Ultraviolet Explorer (EUVE) all-sky survey (58-740 A) and deep survey (67-364 A) are presented through the EUVE Bright Source List (BSL). The BSL contains 356 confirmed extreme ultraviolet (EUV) point sources with supporting information, including positions, observed EUV count rates, and the identification of possible optical counterparts. One-hundred twenty-six sources have been detected longward of 200 A.

  7. UV-bright stars in globular clusters

    NASA Technical Reports Server (NTRS)

    Landsman, Wayne B.

    1994-01-01

    This paper highlights globular cluster studies with Ultraviolet Imaging Telescope (UIT) in three areas: the discrepancy between observed ultraviolet HB magnitudes and predictions of theoretical HB models; the discovery of two hot subdwarfs in NGC 1851, a globular not previously known to contain such stars; and spectroscopic follow up of newly identified UV-bright stars in M79 and w Cen. I also present results of a recent observation of NGC 6397 with the Voyager ultraviolet spectrometer.

  8. Modular Zero Energy. BrightBuilt Home

    SciTech Connect

    Aldrich, Robb; Butterfield, Karla

    2016-03-01

    With funding from the Building America Program, part of the U.S. Department of Energy Building Technologies Office, the Consortium for Advanced Residential Buildings (CARB) worked with BrightBuilt Home (BBH) to evaluate and optimize building systems. CARB’s work focused on a home built by Black Bros. Builders in Lincolnville, Maine (International Energy Conservation Code Climate Zone 6). As with most BBH projects to date, modular boxes were built by Keiser Homes in Oxford, Maine.

  9. Nonlinear Brightness Optimization in Compton Scattering

    NASA Astrophysics Data System (ADS)

    Hartemann, Fred V.; Wu, Sheldon S. Q.

    2013-07-01

    In Compton scattering light sources, a laser pulse is scattered by a relativistic electron beam to generate tunable x and gamma rays. Because of the inhomogeneous nature of the incident radiation, the relativistic Lorentz boost of the electrons is modulated by the ponderomotive force during the interaction, leading to intrinsic spectral broadening and brightness limitations. These effects are discussed, along with an optimization strategy to properly balance the laser bandwidth, diffraction, and nonlinear ponderomotive force.

  10. Spectral Characterization of Bright Materials on Vesta

    NASA Technical Reports Server (NTRS)

    Capaccioni, Fabrizio; DeSanctis, M. C.; Ammannito, E.; Li, Jian-Yang; Longobardo, A.; Mittlefehldt, David W.; Palomba, E.; Pieters, C. M.; Schroeder, S. E.; Tosi, F.; hide

    2012-01-01

    The surface of Vesta, as observed by the camera and imaging spectrometer onboard the Dawn spacecraft, displays large surface diversity in terms of its geology and mineralogy with noticeably dark and bright areas on the surface often associated with various geological features and showing remarkably different forms. Here we report our initial attempt to spectrally characterize the areas that are distinctively brighter than their surroundings.

  11. Australia 31-GHz brightness temperature exceedance statistics

    NASA Technical Reports Server (NTRS)

    Gary, B. L.

    1988-01-01

    Water vapor radiometer measurements were made at DSS 43 during an 18 month period. Brightness temperatures at 31 GHz were subjected to a statistical analysis which included correction for the effects of occasional water on the radiometer radome. An exceedance plot was constructed, and the 1 percent exceedance statistics occurs at 120 K. The 5 percent exceedance statistics occurs at 70 K, compared with 75 K in Spain. These values are valid for all of the three month groupings that were studied.

  12. iPTF report of bright transients

    NASA Astrophysics Data System (ADS)

    Cannella, Chris; Kuesters, Daniel; Ferretti, Raphael; Blagorodnova, Nadejda; Adams, Scott; Kupfer, Thomas; Neill, James D.; Walters, Richard; Yan, Lin; Kulkarni, Shri

    2017-02-01

    The intermediate Palomar Transient Factory (iPTF; ATel #4807) reports the following bright ( Our automated candidate vetting to distinguish a real astrophysical source (1.0) from bogus artifacts (0.0) is powered by three generations of machine learning algorithms: RB2 (Brink et al. 2013MNRAS.435.1047B), RB4 (Rebbapragada et al. 2015AAS...22543402R), and RB5 (Wozniak et al. 2013AAS...22143105W).

  13. Nonlinear Brightness Optimization in Compton Scattering

    SciTech Connect

    Hartemann, Fred V.; Wu, Sheldon S. Q.

    2013-07-26

    In Compton scattering light sources, a laser pulse is scattered by a relativistic electron beam to generate tunable x and gamma rays. Because of the inhomogeneous nature of the incident radiation, the relativistic Lorentz boost of the electrons is modulated by the ponderomotive force during the interaction, leading to intrinsic spectral broadening and brightness limitations. We discuss these effects, along with an optimization strategy to properly balance the laser bandwidth, diffraction, and nonlinear ponderomotive force.

  14. Nonlinear brightness optimization in compton scattering.

    PubMed

    Hartemann, Fred V; Wu, Sheldon S Q

    2013-07-26

    In Compton scattering light sources, a laser pulse is scattered by a relativistic electron beam to generate tunable x and gamma rays. Because of the inhomogeneous nature of the incident radiation, the relativistic Lorentz boost of the electrons is modulated by the ponderomotive force during the interaction, leading to intrinsic spectral broadening and brightness limitations. These effects are discussed, along with an optimization strategy to properly balance the laser bandwidth, diffraction, and nonlinear ponderomotive force.

  15. Rich catalytic injection

    SciTech Connect

    Veninger, Albert

    2008-12-30

    A gas turbine engine includes a compressor, a rich catalytic injector, a combustor, and a turbine. The rich catalytic injector includes a rich catalytic device, a mixing zone, and an injection assembly. The injection assembly provides an interface between the mixing zone and the combustor. The injection assembly can inject diffusion fuel into the combustor, provides flame aerodynamic stabilization in the combustor, and may include an ignition device.

  16. Hydrogen rich gas generator

    NASA Technical Reports Server (NTRS)

    Houseman, J. (Inventor)

    1976-01-01

    A process and apparatus is described for producing a hydrogen rich gas by introducing a liquid hydrocarbon fuel in the form of a spray into a partial oxidation region and mixing with a mixture of steam and air that is preheated by indirect heat exchange with the formed hydrogen rich gas, igniting the hydrocarbon fuel spray mixed with the preheated mixture of steam and air within the partial oxidation region to form a hydrogen rich gas.

  17. Bright Ray Craters in Ganymede's Northern Hemisphere

    NASA Technical Reports Server (NTRS)

    1979-01-01

    GANYMEDE COLOR PHOTOS: This color picture as acquired by Voyager 1 during its approach to Ganymede on Monday afternoon (the 5th of March). At ranges between about 230 to 250 thousand km. The images show detail on the surface with a resolution of four and a half km. This picture is of a region in the northern hemisphere near the terminator. It shows a variety of impact structures, including both razed and unrazed craters, and the odd, groove-like structures discovered by Voyager in the lighter regions. The most striking features are the bright ray craters which have a distinctly 'bluer' color appearing white against the redder background. Ganymede's surface is known to contain large amounts of surface ice and it appears that these relatively young craters have spread bright fresh ice materials over the surface. Likewise, the lighter color and reflectivity of the grooved areas suggests that here, too, there is cleaner ice. We see ray craters with all sizes of ray patterns, ranging from extensive systems of the crater in the southern part of this picture, which has rays at least 300-500 kilometers long, down to craters which have only faint remnants of bright ejects patterns (such as several of the craters in the southern half of PIA01516; P21262). This variation suggests that, as on the Moon, there are processes which act to darken ray material, probably 'gardening' by micrometeoroid impact. JPL manages and controls the Voyager project for NASA's Office of Space Science.

  18. Search for bright stars with infrared excess

    SciTech Connect

    Raharto, Moedji

    2014-03-24

    Bright stars, stars with visual magnitude smaller than 6.5, can be studied using small telescope. In general, if stars are assumed as black body radiator, then the color in infrared (IR) region is usually equal to zero. Infrared data from IRAS observations at 12 and 25μm (micron) with good flux quality are used to search for bright stars (from Bright Stars Catalogues) with infrared excess. In magnitude scale, stars with IR excess is defined as stars with IR color m{sub 12}−m{sub 25}>0; where m{sub 12}−m{sub 25} = −2.5log(F{sub 12}/F{sub 25})+1.56, where F{sub 12} and F{sub 25} are flux density in Jansky at 12 and 25μm, respectively. Stars with similar spectral type are expected to have similar color. The existence of infrared excess in the same spectral type indicates the existence of circum-stellar dust, the origin of which is probably due to the remnant of pre main-sequence evolution during star formation or post AGB evolution or due to physical process such as the rotation of those stars.

  19. Dark and Bright Terrains of Pluto

    NASA Image and Video Library

    2015-07-10

    These circular maps shows the distribution of Pluto's dark and bright terrains as revealed by NASA's New Horizons mission prior to July 4, 2015. Each map is an azimuthal equidistant projection centered on the north pole, with latitude and longitude indicated. Both a gray-scale and color version are shown. The gray-scale version is based on 7 days of panchromatic imaging from the Long Range Reconnaissance Imager (LORRI), whereas the color version uses the gray-scale base and incorporates lower-resolution color information from the Multi-spectral Visible Imaging Camera (MVIC), part of the Ralph instrument. The color version is also shown in a simple cylindrical projection in PIA19700. In these maps, the polar bright terrain is surrounded by a somewhat darker polar fringe, one whose latitudinal position varies strongly with longitude. Especially striking are the much darker regions along the equator. A broad dark swath ("the whale") stretches along the equator from approximately 20 to 160 degrees of longitude. Several dark patches appear in a regular sequence centered near 345 degrees of longitude. A spectacular bright region occupies Pluto's mid-latitudes near 180 degrees of longitude, and stretches southward over the equator. New Horizons' closest approach to Pluto will occur near this longitude, which will permit high-resolution visible imaging and compositional mapping of these various regions. http://photojournal.jpl.nasa.gov/catalog/PIA19706

  20. Bright and Dark Slopes on Ganymede

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Ridges on the edge of Ganymede's north polar cap show bright east-facing slopes and dark west-facing slopes with troughs of darker material below the larger ridges. North is to the top. The bright slopes may be due to grain size differences, differences in composition between the original surface and the underlying material, frost deposition, or illumination effects. The large 2.4 kilometer (1.5 mile) diameter crater in this image shows frost deposits located on the north-facing rim slope, away from the sun. A smaller 675 meter (2200 foot) diameter crater in the center of the image is surrounded by a bright deposit which may be ejecta from the impact. Ejecta deposits such as this are uncommon for small craters on Ganymede. This image measures 18 by 19 kilometers (11 by 12 miles) and has a resolution of 45 meters (148 feet) per pixel. NASA's Galileo spacecraft obtained this image on September 6, 1996 during its second orbit around Jupiter.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  1. Brightness Changes in Sun-like Stars

    NASA Technical Reports Server (NTRS)

    Henry, Stephen M.; Henry, Gregory W.

    1998-01-01

    Does the Sun's energy output vary with time? Are observable climatic changes on the earth caused by changes in the Sun? Can we gain greater insight into this relation-ship by studying other stars with properties similar to the Sun's? In recent years, satellite observations have shown that the solar irradiance varies in phase with the 1 l-year sunspot cycle. The Sun is brighter by about O.l% at the peak of the sunspot cycle when solar magnetic activity is at its maximum. Over longer intervals, changes in the cart h's climate and solar magnetic activity seem to be correlated. We are using automatic photoelectric telescopes to measure brightness changes in a sample of 150 Sun-like stars. Lowell Observatory astronomers have also observed about 30 of these same stars with a manual telescope in a program that began 10 years before ours. Since these two data sets were acquired with different instruments and so have significant systematic differences, we developed software to combine them accurately and, therefore, extend our observational time coverage. We show sample results of brightness variations over 14 years in several Sun-like stars with different ages. Longitudinal studies like these, combined with cross-sectional studies of the larger sample of stars, may eventually allow us to infer with confidence the Sun's long-term brightness history and its impact on the earth's climate.

  2. Bright and Dark Slopes on Ganymede

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Ridges on the edge of Ganymede's north polar cap show bright east-facing slopes and dark west-facing slopes with troughs of darker material below the larger ridges. North is to the top. The bright slopes may be due to grain size differences, differences in composition between the original surface and the underlying material, frost deposition, or illumination effects. The large 2.4 kilometer (1.5 mile) diameter crater in this image shows frost deposits located on the north-facing rim slope, away from the sun. A smaller 675 meter (2200 foot) diameter crater in the center of the image is surrounded by a bright deposit which may be ejecta from the impact. Ejecta deposits such as this are uncommon for small craters on Ganymede. This image measures 18 by 19 kilometers (11 by 12 miles) and has a resolution of 45 meters (148 feet) per pixel. NASA's Galileo spacecraft obtained this image on September 6, 1996 during its second orbit around Jupiter.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  3. Personal audio with a planar bright zone.

    PubMed

    Coleman, Philip; Jackson, Philip J B; Olik, Marek; Pedersen, Jan Abildgaard

    2014-10-01

    Reproduction of multiple sound zones, in which personal audio programs may be consumed without the need for headphones, is an active topic in acoustical signal processing. Many approaches to sound zone reproduction do not consider control of the bright zone phase, which may lead to self-cancellation problems if the loudspeakers surround the zones. Conversely, control of the phase in a least-squares sense comes at a cost of decreased level difference between the zones and frequency range of cancellation. Single-zone approaches have considered plane wave reproduction by focusing the sound energy in to a point in the wavenumber domain. In this article, a planar bright zone is reproduced via planarity control, which constrains the bright zone energy to impinge from a narrow range of angles via projection in to a spatial domain. Simulation results using a circular array surrounding two zones show the method to produce superior contrast to the least-squares approach, and superior planarity to the contrast maximization approach. Practical performance measurements obtained in an acoustically treated room verify the conclusions drawn under free-field conditions.

  4. Brightness illusion in the guppy (Poecilia reticulata).

    PubMed

    Agrillo, Christian; Miletto Petrazzini, Maria Elena; Bisazza, Angelo

    2016-02-01

    A long-standing debate surrounds the issue of whether human and nonhuman species share similar perceptual mechanisms. One experimental strategy to compare visual perception of vertebrates consists in assessing how animals react in the presence of visual illusions. To date, this methodological approach has been widely used with mammals and birds, while few studies have been reported in distantly related species, such as fish. In the present study we investigated whether fish perceive the brightness illusion, a well-known illusion occurring when 2 objects, identical in physical features, appear to be different in brightness. Twelve guppies (Poecilia reticulata) were initially trained to discriminate which rectangle was darker or lighter between 2 otherwise identical rectangles. Three different conditions were set up: neutral condition between rectangle and background (same background used for both darker and lighter rectangle); congruent condition (darker rectangle in a darker background and lighter rectangle in a lighter background); and incongruent condition (darker rectangle in a lighter background and lighter rectangle in a darker background). After reaching the learning criterion, guppies were presented with the illusory pattern: 2 identical rectangles inserted in 2 different backgrounds. Guppies previously trained to select the darker rectangle showed a significant choice of the rectangle that appears to be darker by human observers (and vice versa). The human-like performance exhibited in the presence of the illusory pattern suggests the existence of similar perceptual mechanisms between humans and fish to elaborate the brightness of objects.

  5. Edge detection and reduction of brightness of students' bubble form images

    NASA Astrophysics Data System (ADS)

    Ilkin, Sümeyya; Şahin, Suhap

    2015-03-01

    Optical Mark Recognition (OMR) is a traditional data input technique and an important human computer interaction technique which is widely used in education testing. This paper proposes a new idea for grading multiple-choice test which is based on a camera on smartphone. The system key techniques and relevant implementations, which include the image scan, edge detection and reduction of brightness on colorful bubble form images, are presented.

  6. A nitrogen-rich nebula

    NASA Image and Video Library

    2015-06-29

    This NASA/ESA Hubble Space Telescope image shows a planetary nebula named NGC 6153, located about 4000 light-years away in the southern constellation of Scorpius (The Scorpion). The faint blue haze across the frame shows what remains of a star like the Sun after it has depleted most of its fuel. When this happens, the outer layers of the star are ejected, and get excited and ionised by the energetic ultraviolet light emitted by the bright hot core of the star, forming the nebula. NGC 6153 is a planetary nebula that is elliptical in shape, with an extremely rich network of loops and filaments, shown clearly in this Hubble image. However, this is not what makes this planetary nebula so interesting for astronomers. Measurements show that NGC 6153 contains large amounts of neon, argon, oxygen, carbon and chlorine — up to three times more than can be found in the Solar System. The nebula contains a whopping five times more nitrogen than the Sun! Although it may be that the star developed higher levels of these elements as it grew and evolved, it is more likely that the star originally formed from a cloud of material that already contained lots more of these elements. A version of this image was entered into the Hubble’s Hidden Treasures image processing competition by contestant Matej Novak. Links Matej Novak’s image on Flickr

  7. Bright and Dark at West Rim of Marcia Crater

    NASA Image and Video Library

    2012-03-21

    The interplay of bright and dark material at the rim of Marcia crater on Vesta is visible in this image mosaic taken by NASA Dawn spacecraft. The bright and dark material appear to be exposed from weathering.

  8. Apparent Brightness and Topography Images of Calpurnia and Minucia

    NASA Image and Video Library

    2012-03-13

    Located in the Marcia quadrangle, the left-hand image from NASA Dawn spacecraft shows the apparent brightness of asteroid Vesta surface. The right-hand image is based on this apparent brightness image.

  9. Research: Rags to Rags? Riches to Riches?

    ERIC Educational Resources Information Center

    Bracey, Gerald W.

    2004-01-01

    Everyone has read about what might be called the "gold gap"--how the rich in this country are getting richer and controlling an ever-larger share of the nation's wealth. The Century Foundation has started publishing "Reality Check", a series of guides to campaign issues that sometimes finds gaps in these types of cherished delusions. The guides…

  10. Active Processes: Bright Streaks and Dark Fans

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1Figure 2

    In a region of the south pole known informally as 'Ithaca' numerous fans of dark frost form every spring. HiRISE collected a time lapse series of these images, starting at Ls = 185 and culminating at Ls = 294. 'Ls' is the way we measure time on Mars: at Ls = 180 the sun passes the equator on its way south; at Ls = 270 it reaches its maximum subsolar latitude and summer begins.

    In the earliest image (figure 1) fans are dark, but small narrow bright streaks can be detected. In the next image (figure 2), acquired at Ls = 187, just 106 hours later, dramatic differences are apparent. The dark fans are larger and the bright fans are more pronounced and easily detectable. The third image in the sequence shows no bright fans at all.

    We believe that the bright streaks are fine frost condensed from the gas exiting the vent. The conditions must be just right for the bright frost to condense.

    Observation Geometry Image PSP_002622_0945 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 16-Feb-2007. The complete image is centered at -85.2 degrees latitude, 181.5 degrees East longitude. The range to the target site was 246.9 km (154.3 miles). At this distance the image scale is 49.4 cm/pixel (with 2 x 2 binning) so objects 148 cm across are resolved. The image shown here has been map-projected to 50 cm/pixel . The image was taken at a local Mars time of 05:46 PM and the scene is illuminated from the west with a solar incidence angle of 88 degrees, thus the sun was about 2 degrees above the horizon. At a solar longitude of 185.1 degrees, the season on Mars is Northern Autumn.

  11. Active Processes: Bright Streaks and Dark Fans

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1Figure 2

    In a region of the south pole known informally as 'Ithaca' numerous fans of dark frost form every spring. HiRISE collected a time lapse series of these images, starting at Ls = 185 and culminating at Ls = 294. 'Ls' is the way we measure time on Mars: at Ls = 180 the sun passes the equator on its way south; at Ls = 270 it reaches its maximum subsolar latitude and summer begins.

    In the earliest image (figure 1) fans are dark, but small narrow bright streaks can be detected. In the next image (figure 2), acquired at Ls = 187, just 106 hours later, dramatic differences are apparent. The dark fans are larger and the bright fans are more pronounced and easily detectable. The third image in the sequence shows no bright fans at all.

    We believe that the bright streaks are fine frost condensed from the gas exiting the vent. The conditions must be just right for the bright frost to condense.

    Observation Geometry Image PSP_002622_0945 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 16-Feb-2007. The complete image is centered at -85.2 degrees latitude, 181.5 degrees East longitude. The range to the target site was 246.9 km (154.3 miles). At this distance the image scale is 49.4 cm/pixel (with 2 x 2 binning) so objects 148 cm across are resolved. The image shown here has been map-projected to 50 cm/pixel . The image was taken at a local Mars time of 05:46 PM and the scene is illuminated from the west with a solar incidence angle of 88 degrees, thus the sun was about 2 degrees above the horizon. At a solar longitude of 185.1 degrees, the season on Mars is Northern Autumn.

  12. 7 CFR 51.2000 - Clean and bright.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Clean and bright. 51.2000 Section 51.2000 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing....2000 Clean and bright. Clean and bright means that the individual filbert and the lot as a whole...

  13. 7 CFR 51.2000 - Clean and bright.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Clean and bright. 51.2000 Section 51.2000 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing....2000 Clean and bright. Clean and bright means that the individual filbert and the lot as a whole...

  14. Two types of coronal bright points their characteristics, and evolution

    NASA Astrophysics Data System (ADS)

    Sattarov, Isroil; Karachik, Nina V.; Sherdanov, Chori T.; Tillaboev, Azlarxon M.; Pevtsov, Alexei A.

    2011-08-01

    Using maximum brightness of coronal bright point's (CBP) as a criterion, we separate them on two categories: dim CBPs, associated with areas of a quiet Sun, and bright CBPs, associated with an active Sun. This study reports on characteristics of two types of CBPs and their evolution.

  15. The Effect of Brightness of Lamps Teaching Based on the 5E Model on Students' Academic Achievement and Attitudes

    ERIC Educational Resources Information Center

    Guzel, Hatice

    2016-01-01

    The purpose of this research was to examine and compare the effect of teaching the brightness of lamps, which is a topic for grade 11 physics lesson, on student achievement and attitude according to the 5E model belonging to the constructivist learning theory and the traditional teaching method. The research was conducted on 62 11th grade students…

  16. Calculation of gyrosynchrotron radiation brightness temperature for outer bright loop of ICME

    NASA Astrophysics Data System (ADS)

    Sun, Weiying; Wu, Ji; Wang, C. B.; Wang, S.

    :Solar polar orbit radio telescope (SPORT) is proposed to detect the high density plasma clouds of outer bright loop of ICMEs from solar orbit with large inclination. Of particular interest is following the propagation of the plasma clouds with remote sensor in radio wavelength band. Gyrosynchrotron emission is a main radio radiation mechanism of the plasma clouds and can provide information of interplanetary magnetic field. In this paper, we statistically analyze the electron density, electron temperature and magnetic field of background solar wind in time of quiet sun and ICMEs propagation. We also estimate the fluctuation range of the electron density, electron temperature and magnetic field of outer bright loop of ICMEs. Moreover, we calculate and analyze the emission brightness temperature and degree of polarization on the basis of the study of gyrosynchrotron emission, absorption and polarization characteristics as the optical depth is less than or equal to 1.

  17. Dark and Bright Ridges on Europa

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This high-resolution image of Jupiter's moon Europa, taken by NASA's Galileo spacecraft camera, shows dark, relatively smooth region at the lower right hand corner of the image which may be a place where warm ice has welled up from below. The region is approximately 30 square kilometers in area. An isolated bright hill stands within it. The image also shows two prominent ridges which have different characteristics; youngest ridge runs from left to top right and is about 5 kilometers in width (about 3.1 miles). The ridge has two bright, raised rims and a central valley. The rims of the ridge are rough in texture. The inner and outer walls show bright and dark debris streaming downslope, some of it forming broad fans. This ridge overlies and therefore must be younger than a second ridge running from top to bottom on the left side of the image. This dark 2 km wide ridge is relatively flat, and has smaller-scale ridges and troughs along its length.

    North is to the top of the picture, and the sun illuminates the surface from the upper left. This image, centered at approximately 14 degrees south latitude and 194 degrees west longitude, covers an area approximately 15 kilometers by 20 kilometers (9 miles by 12 miles). The resolution is 26 meters (85 feet) per picture element. This image was taken on December 16, 1997 at a range of 1300 kilometers (800 miles) by Galileo's solid state imaging system.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://www.jpl.nasa.gov/ galileo.

  18. Dark and Bright Ridges on Europa

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This high-resolution image of Jupiter's moon Europa, taken by NASA's Galileo spacecraft camera, shows dark, relatively smooth region at the lower right hand corner of the image which may be a place where warm ice has welled up from below. The region is approximately 30 square kilometers in area. An isolated bright hill stands within it. The image also shows two prominent ridges which have different characteristics; youngest ridge runs from left to top right and is about 5 kilometers in width (about 3.1 miles). The ridge has two bright, raised rims and a central valley. The rims of the ridge are rough in texture. The inner and outer walls show bright and dark debris streaming downslope, some of it forming broad fans. This ridge overlies and therefore must be younger than a second ridge running from top to bottom on the left side of the image. This dark 2 km wide ridge is relatively flat, and has smaller-scale ridges and troughs along its length.

    North is to the top of the picture, and the sun illuminates the surface from the upper left. This image, centered at approximately 14 degrees south latitude and 194 degrees west longitude, covers an area approximately 15 kilometers by 20 kilometers (9 miles by 12 miles). The resolution is 26 meters (85 feet) per picture element. This image was taken on December 16, 1997 at a range of 1300 kilometers (800 miles) by Galileo's solid state imaging system.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://www.jpl.nasa.gov/ galileo.

  19. Rotation and macroturbulence in bright giants

    SciTech Connect

    Gray, D.F.; Toner, C.G.

    1986-11-01

    Spectral line profiles of 35 F, G, and K bright giants were analyzed to obtain rotation rates, v sin i, and macroturbulence dispersion. This sample indicates that rotation rates of cool class II giants is less than 11 km/s, in contrast with some recent periodicity measurements. Macroturbulence dispersion generally increases with effective temperature, but the range of values at a given effective temperature is much larger than seen for lower luminosity classes; this is interpreted in terms of red-giant and blue-loop evolution. No evidence is found for angular momentum dissipation on the first crossing of the H-R diagram. 57 references.

  20. Raman beam combining for laser brightness enhancement

    DOEpatents

    Dawson, Jay W.; Allen, Graham S.; Pax, Paul H.; Heebner, John E.; Sridharan, Arun K.; Rubenchik, Alexander M.; Barty, Chrisopher B. J.

    2015-10-27

    An optical source capable of enhanced scaling of pulse energy and brightness utilizes an ensemble of single-aperture fiber lasers as pump sources, with each such fiber laser operating at acceptable pulse energy levels. Beam combining involves stimulated Raman scattering using a Stokes' shifted seed beam, the latter of which is optimized in terms of its temporal and spectral properties. Beams from fiber lasers can thus be combined to attain pulses with peak energies in excess of the fiber laser self-focusing limit of 4 MW while retaining the advantages of a fiber laser system of high average power with good beam quality.

  1. Two-color bright squeezed vacuum

    SciTech Connect

    Agafonov, Ivan N.; Chekhova, Maria V.

    2010-07-15

    In a strongly pumped nondegenerate traveling-wave optical parametric amplifier, we produce a two-color squeezed vacuum with up to millions of photons per pulse. Our approach to registering this macroscopic quantum state is direct detection of a large number of transverse and longitudinal modes, which is achieved by making the detection time and area much larger than the coherence time and area, respectively. Using this approach, we obtain a record value of twin-beam squeezing for direct detection of bright squeezed vacuum. This makes direct detection of macroscopic squeezed vacuum a practical tool for quantum information applications.

  2. Apparent brightness distribution of GRB host galaxies

    NASA Astrophysics Data System (ADS)

    Bagoly, Zsolt; Rácz, István I.; Balázs, Lajos G.; Horváth, István; Tóth, L. Viktor

    We studied the unbiased optical brightness distribution which was calculated from the survival analysis of host galaxies (HGs) data and its relationship with the Swift GRB data of the host galaxies observed by the Keck telescope. Based on the sample obtained from merging the Swift GRB table and the Keck optical data we also studied the dependence of this distribution on the GRB's data. Finally, we compared the HGs distribution with standard galaxies distribution of the DEEP2 redshift survey and checked the result with the VIPERS catalogue too.

  3. Integrating spatial and temporal approaches to understanding species richness

    PubMed Central

    White, Ethan P.; Ernest, S. K. Morgan; Adler, Peter B.; Hurlbert, Allen H.; Lyons, S. Kathleen

    2010-01-01

    Understanding species richness patterns represents one of the most fundamental problems in ecology. Most research in this area has focused on spatial gradients of species richness, with a smaller area of emphasis dedicated to understanding the temporal dynamics of richness. However, few attempts have been made to understand the linkages between the spatial and temporal patterns related to richness. Here, we argue that spatial and temporal richness patterns and the processes that drive them are inherently linked, and that our understanding of richness will be substantially improved by considering them simultaneously. The species–time–area relationship provides a case in point: successful description of the empirical spatio-temporal pattern led to a rapid development and testing of new theories. Other areas of research on species richness could also benefit from an explicitly spatio-temporal approach, and we suggest future directions for understanding the processes common to these two traditionally isolated fields of research. PMID:20980312

  4. A Brightness-Referenced Star Identification Algorithm for APS Star Trackers

    PubMed Central

    Zhang, Peng; Zhao, Qile; Liu, Jingnan; Liu, Ning

    2014-01-01

    Star trackers are currently the most accurate spacecraft attitude sensors. As a result, they are widely used in remote sensing satellites. Since traditional charge-coupled device (CCD)-based star trackers have a limited sensitivity range and dynamic range, the matching process for a star tracker is typically not very sensitive to star brightness. For active pixel sensor (APS) star trackers, the intensity of an imaged star is valuable information that can be used in star identification process. In this paper an improved brightness referenced star identification algorithm is presented. This algorithm utilizes the k-vector search theory and adds imaged stars' intensities to narrow the search scope and therefore increase the efficiency of the matching process. Based on different imaging conditions (slew, bright bodies, etc.) the developed matching algorithm operates in one of two identification modes: a three-star mode, and a four-star mode. If the reference bright stars (the stars brighter than three magnitude) show up, the algorithm runs the three-star mode and efficiency is further improved. The proposed method was compared with other two distinctive methods the pyramid and geometric voting methods. All three methods were tested with simulation data and actual in orbit data from the APS star tracker of ZY-3. Using a catalog composed of 1500 stars, the results show that without false stars the efficiency of this new method is 4∼5 times that of the pyramid method and 35∼37 times that of the geometric method. PMID:25299950

  5. A brightness-referenced star identification algorithm for APS star trackers.

    PubMed

    Zhang, Peng; Zhao, Qile; Liu, Jingnan; Liu, Ning

    2014-10-08

    Star trackers are currently the most accurate spacecraft attitude sensors. As a result, they are widely used in remote sensing satellites. Since traditional charge-coupled device (CCD)-based star trackers have a limited sensitivity range and dynamic range, the matching process for a star tracker is typically not very sensitive to star brightness. For active pixel sensor (APS) star trackers, the intensity of an imaged star is valuable information that can be used in star identification process. In this paper an improved brightness referenced star identification algorithm is presented. This algorithm utilizes the k-vector search theory and adds imaged stars' intensities to narrow the search scope and therefore increase the efficiency of the matching process. Based on different imaging conditions (slew, bright bodies, etc.) the developed matching algorithm operates in one of two identification modes: a three-star mode, and a four-star mode. If the reference bright stars (the stars brighter than three magnitude) show up, the algorithm runs the three-star mode and efficiency is further improved. The proposed method was compared with other two distinctive methods the pyramid and geometric voting methods. All three methods were tested with simulation data and actual in orbit data from the APS star tracker of ZY-3. Using a catalog composed of 1500 stars, the results show that without false stars the efficiency of this new method is 4~5 times that of the pyramid method and 35~37 times that of the geometric method.

  6. Brightness preserving image enhancement based on a gradient and intensity histogram

    NASA Astrophysics Data System (ADS)

    Sun, Zebin; Feng, Wenquan; Zhao, Qi; Huang, Lidong

    2015-09-01

    We present a straightforward brightness preserving image enhancement technique. The proposed method is based on an original gradient and intensity histogram (GIH) which contains both gradient and intensity information of the image. This character enables GIH to avoid high peaks in the traditional intensity histogram and, thus alleviate overenhancement in our enhancement method, i.e., gradient and intensity histogram equalization (GIHE). GIHE can also enhance the gradient strength of an image, which is good for improving the subjective quality since the human vision system is more sensitive to the gradient than the absolute intensity of image. Considering that brightness preservation and dynamic range compression are highly demanded in consumer electronics, we manipulate the intensity of the enhanced image appropriately by amplifying the small intensities and attenuating the large intensities, respectively, using a brightness preserving function (BPF). The BPF is straightforward and universal and can be used in other image enhancement techniques. We demonstrate that the proposed method can effectively improve the subjective quality as well as preserve the brightness of the input image.

  7. Adaptive brightness transfer functions in echocardiography.

    PubMed

    Zwirn, Gil; Akselrod, Solange

    2005-05-01

    Despite the clear advantages of echocardiography as a diagnostic tool, its images tend to be noisy and unclear. This paper presents an innovative algorithm, called ABTF (adaptive brightness transfer function), designed to optimally adjust the gray-levels used in echocardiography. The algorithm is aimed at aiding in visual tissue classification and texture-based visual tissue tracking in echocardiographic images. The ABTF method is based on fitting the cine-loop's gray-level histogram to a sum of three Gaussian functions, each of which relates to a different region within the image, the left ventricular cavity, the relatively dark regions within the cardiac muscle and the bright regions within the cardiac muscle. The procedure's feasibility has been supported by a test-set, including 23 echocardiographic cine-loops from 10 different patients. The resulting image quality appears to be superior to that of the original images, tending to show better contrast and a higher dynamic range of gray-levels within the cardiac muscle. According to two expert cardiologists, who have blindly ranked the image quality of each cine-loop on a scale from 1 to 10, where 10 corresponds to the highest possible image quality, the mean score of the original cine-loops is 7.1 +/- 1.1, while the mean score of the cine-loops to which ABTF has been applied is 8.0 +/- 1.2.

  8. A high brightness field emission display

    SciTech Connect

    Palevsky, A.

    1996-12-31

    The military requirement for avionics display performance requires that displays be legible with 10,000 foot-candles (fc) bright light shining into the pilot`s eyes, or 10,000 fc shining directly on the display. The contrast ratio under these conditions must be at least 4.66:1. In addition, instant-on operation is sought for temperatures as low as {minus}54 C. Currently these specifications can barely be met by monochrome CRTs whose use is counter-indicated by other factors. No color display can achieve optimum performance in the areas mentioned, nor do any current contenders, primarily AMLCD`s, have any prospects of achieving full compliance. The FED being developed by Raytheon shows strong promise of being able to achieve the brightness and contrast ratios desired. The FED is also inherently able to provide instant-on functionality at any terrestrial temperature and does not require any heating at low temperatures. The technical objective of the Raytheon development program is to develop a high performance, full color, FED Panel that meets the performance and environmental operating condition requirements specified for military and other high performance display applications.

  9. At Bright Band Inside Victoria Crater

    NASA Technical Reports Server (NTRS)

    2007-01-01

    A layer of light-toned rock exposed inside Victoria Crater in the Meridiani Planum region of Mars appears to mark where the surface was at the time, many millions of years ago, when an impact excavated the crater. NASA's Mars Exploration Rover Opportunity drove to this bright band as the science team's first destination for the rover during investigations inside the crater.

    Opportunity's left front hazard-identification camera took this image just after the rover finished a drive of 2.25 meters (7 feet, 5 inches) during the rover's 1,305th Martian day, or sol, (Sept. 25, 2007). The rocks beneath the rover and its extended robotic arm are part of the bright band.

    Victoria Crater has a scalloped shape of alternating alcoves and promontories around the crater's circumference. Opportunity descended into the crater two weeks earlier, within an alcove called 'Duck Bay.' Counterclockwise around the rim, just to the right of the arm in this image, is a promontory called 'Cabo Frio.'

  10. Sublimation in bright spots on (1) Ceres.

    PubMed

    Nathues, A; Hoffmann, M; Schaefer, M; Le Corre, L; Reddy, V; Platz, T; Cloutis, E A; Christensen, U; Kneissl, T; Li, J-Y; Mengel, K; Schmedemann, N; Schaefer, T; Russell, C T; Applin, D M; Buczkowski, D L; Izawa, M R M; Keller, H U; O'Brien, D P; Pieters, C M; Raymond, C A; Ripken, J; Schenk, P M; Schmidt, B E; Sierks, H; Sykes, M V; Thangjam, G S; Vincent, J-B

    2015-12-10

    The dwarf planet (1) Ceres, the largest object in the main asteroid belt with a mean diameter of about 950 kilometres, is located at a mean distance from the Sun of about 2.8 astronomical units (one astronomical unit is the Earth-Sun distance). Thermal evolution models suggest that it is a differentiated body with potential geological activity. Unlike on the icy satellites of Jupiter and Saturn, where tidal forces are responsible for spewing briny water into space, no tidal forces are acting on Ceres. In the absence of such forces, most objects in the main asteroid belt are expected to be geologically inert. The recent discovery of water vapour absorption near Ceres and previous detection of bound water and OH near and on Ceres (refs 5-7) have raised interest in the possible presence of surface ice. Here we report the presence of localized bright areas on Ceres from an orbiting imager. These unusual areas are consistent with hydrated magnesium sulfates mixed with dark background material, although other compositions are possible. Of particular interest is a bright pit on the floor of crater Occator that exhibits probable sublimation of water ice, producing haze clouds inside the crater that appear and disappear with a diurnal rhythm. Slow-moving condensed-ice or dust particles may explain this haze. We conclude that Ceres must have accreted material from beyond the 'snow line', which is the distance from the Sun at which water molecules condense.

  11. Coronal Bright Points Associated with Minifilament Eruptions

    NASA Astrophysics Data System (ADS)

    Hong, Junchao; Jiang, Yunchun; Yang, Jiayan; Bi, Yi; Li, Haidong; Yang, Bo; Yang, Dan

    2014-12-01

    Coronal bright points (CBPs) are small-scale, long-lived coronal brightenings that always correspond to photospheric network magnetic features of opposite polarity. In this paper, we subjectively adopt 30 CBPs in a coronal hole to study their eruptive behavior using data from the Atmospheric Imaging Assembly (AIA) and the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory. About one-quarter to one-third of the CBPs in the coronal hole go through one or more minifilament eruption(s) (MFE(s)) throughout their lifetimes. The MFEs occur in temporal association with the brightness maxima of CBPs and possibly result from the convergence and cancellation of underlying magnetic dipoles. Two examples of CBPs with MFEs are analyzed in detail, where minifilaments appear as dark features of a cool channel that divide the CBPs along the neutral lines of the dipoles beneath. The MFEs show the typical rising movements of filaments and mass ejections with brightenings at CBPs, similar to large-scale filament eruptions. Via differential emission measure analysis, it is found that CBPs are heated dramatically by their MFEs and the ejected plasmas in the MFEs have average temperatures close to the pre-eruption BP plasmas and electron densities typically near 109 cm-3. These new observational results indicate that CBPs are more complex in dynamical evolution and magnetic structure than previously thought.

  12. Coronal bright points associated with minifilament eruptions

    SciTech Connect

    Hong, Junchao; Jiang, Yunchun; Yang, Jiayan; Bi, Yi; Li, Haidong; Yang, Bo; Yang, Dan

    2014-12-01

    Coronal bright points (CBPs) are small-scale, long-lived coronal brightenings that always correspond to photospheric network magnetic features of opposite polarity. In this paper, we subjectively adopt 30 CBPs in a coronal hole to study their eruptive behavior using data from the Atmospheric Imaging Assembly (AIA) and the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory. About one-quarter to one-third of the CBPs in the coronal hole go through one or more minifilament eruption(s) (MFE(s)) throughout their lifetimes. The MFEs occur in temporal association with the brightness maxima of CBPs and possibly result from the convergence and cancellation of underlying magnetic dipoles. Two examples of CBPs with MFEs are analyzed in detail, where minifilaments appear as dark features of a cool channel that divide the CBPs along the neutral lines of the dipoles beneath. The MFEs show the typical rising movements of filaments and mass ejections with brightenings at CBPs, similar to large-scale filament eruptions. Via differential emission measure analysis, it is found that CBPs are heated dramatically by their MFEs and the ejected plasmas in the MFEs have average temperatures close to the pre-eruption BP plasmas and electron densities typically near 10{sup 9} cm{sup –3}. These new observational results indicate that CBPs are more complex in dynamical evolution and magnetic structure than previously thought.

  13. Inverse relationship between surface brightness and polarization

    NASA Astrophysics Data System (ADS)

    Egan, Walter G.

    1999-10-01

    There is an inverse relationship between surface brightness and polarization in the wavelength range from the ultraviolet to the near infrared. This relationship was first observed by the French astronomers B. Lyot and A. Dollfus in the early 20th century for planetary surfaces and laboratory models. The relationship was later confirmed principally by Egan and his coworkers in the Grumman Research Department in lunar simulation experiments prior to the Lunar Module landing. The observations indicate that the percent polarization (The percent polarization is the ratio of the difference between two orthogonal polarized measurements ratioed to the sum multiplied by 100) is an inverse function of the surface brightness (albedo). The Grumman instrument was a unique large scale polarimeter/photometer that allowed measurements not only of coated surfaces, but of particulates or structural surfaces up to 10 centimeters in diameter. It was found that, for instance, a diffuse surface having a reflectance of 2% could have a percent polarization of nearly 100%. The polarization was found to be a function of the optical complex index of refraction of the surface and the surface structure, and the relationship was found to be true for farm soils, agricultural and forested areas and was useful to characterize them. Astronomical and recent laboratory data will be presented to illustrate the relationship. More recent polarimeters will be discussed that permit polarization measurements accurate to plus or minus 0.1% from 0 to 100%.

  14. At Bright Band Inside Victoria Crater

    NASA Technical Reports Server (NTRS)

    2007-01-01

    A layer of light-toned rock exposed inside Victoria Crater in the Meridiani Planum region of Mars appears to mark where the surface was at the time, many millions of years ago, when an impact excavated the crater. NASA's Mars Exploration Rover Opportunity drove to this bright band as the science team's first destination for the rover during investigations inside the crater.

    Opportunity's left front hazard-identification camera took this image just after the rover finished a drive of 2.25 meters (7 feet, 5 inches) during the rover's 1,305th Martian day, or sol, (Sept. 25, 2007). The rocks beneath the rover and its extended robotic arm are part of the bright band.

    Victoria Crater has a scalloped shape of alternating alcoves and promontories around the crater's circumference. Opportunity descended into the crater two weeks earlier, within an alcove called 'Duck Bay.' Counterclockwise around the rim, just to the right of the arm in this image, is a promontory called 'Cabo Frio.'

  15. Synchrotron brightness distribution of turbulent radio jets

    NASA Technical Reports Server (NTRS)

    Henriksen, R. N.; Bridle, A. H.; Chan, K. L.

    1981-01-01

    Radio jets are considered as turbulent mixing regions and it is proposed that the essential small scale viscous dissipation in these jets is by emission of MHD waves and by their subsequent strong damping due, at least partly, to gyro-resonant acceleration of supra-thermal particles. A formula relating the synchrotron surface brightness of a radio jet to the turbulent power input is deduced from physical postulates, and is tested against the data for NGC315 and 3C31 (NGC383). The predicted brightness depends essentially on the collimation behavior of the jet, and, to a lesser extent, on the CH picture of a 'high' nozzle with accelerating flow. The conditions for forming a large scale jet at a high nozzle from a much smaller scale jet are discussed. The effect of entrainment on the prediction is discussed with the use of similarity solutions. Although entrainment is inevitably associated with the turbulent jet, it may or may not be a dominant factor depending on the ambient density profile.

  16. Sublimation in bright spots on (1) Ceres

    NASA Astrophysics Data System (ADS)

    Nathues, A.; Hoffmann, M.; Schaefer, M.; Le Corre, L.; Reddy, V.; Platz, T.; Cloutis, E. A.; Christensen, U.; Kneissl, T.; Li, J.-Y.; Mengel, K.; Schmedemann, N.; Schaefer, T.; Russell, C. T.; Applin, D. M.; Buczkowski, D. L.; Izawa, M. R. M.; Keller, H. U.; O'Brien, D. P.; Pieters, C. M.; Raymond, C. A.; Ripken, J.; Schenk, P. M.; Schmidt, B. E.; Sierks, H.; Sykes, M. V.; Thangjam, G. S.; Vincent, J.-B.

    2015-12-01

    The dwarf planet (1) Ceres, the largest object in the main asteroid belt with a mean diameter of about 950 kilometres, is located at a mean distance from the Sun of about 2.8 astronomical units (one astronomical unit is the Earth-Sun distance). Thermal evolution models suggest that it is a differentiated body with potential geological activity. Unlike on the icy satellites of Jupiter and Saturn, where tidal forces are responsible for spewing briny water into space, no tidal forces are acting on Ceres. In the absence of such forces, most objects in the main asteroid belt are expected to be geologically inert. The recent discovery of water vapour absorption near Ceres and previous detection of bound water and OH near and on Ceres (refs 5, 6, 7) have raised interest in the possible presence of surface ice. Here we report the presence of localized bright areas on Ceres from an orbiting imager. These unusual areas are consistent with hydrated magnesium sulfates mixed with dark background material, although other compositions are possible. Of particular interest is a bright pit on the floor of crater Occator that exhibits probable sublimation of water ice, producing haze clouds inside the crater that appear and disappear with a diurnal rhythm. Slow-moving condensed-ice or dust particles may explain this haze. We conclude that Ceres must have accreted material from beyond the ‘snow line’, which is the distance from the Sun at which water molecules condense.

  17. Understanding traditional African healing

    PubMed Central

    MOKGOBI, M.G.

    2015-01-01

    Traditional African healing has been in existence for many centuries yet many people still seem not to understand how it relates to God and religion/spirituality. Some people seem to believe that traditional healers worship the ancestors and not God. It is therefore the aim of this paper to clarify this relationship by discussing a chain of communication between the worshipers and the Almighty God. Other aspects of traditional healing namely types of traditional healers, training of traditional healers as well as the role of traditional healers in their communities are discussed. In conclusion, the services of traditional healers go far beyond the uses of herbs for physical illnesses. Traditional healers serve many roles which include but not limited to custodians of the traditional African religion and customs, educators about culture, counselors, social workers and psychologists. PMID:26594664

  18. Understanding traditional African healing.

    PubMed

    Mokgobi, M G

    2014-09-01

    Traditional African healing has been in existence for many centuries yet many people still seem not to understand how it relates to God and religion/spirituality. Some people seem to believe that traditional healers worship the ancestors and not God. It is therefore the aim of this paper to clarify this relationship by discussing a chain of communication between the worshipers and the Almighty God. Other aspects of traditional healing namely types of traditional healers, training of traditional healers as well as the role of traditional healers in their communities are discussed. In conclusion, the services of traditional healers go far beyond the uses of herbs for physical illnesses. Traditional healers serve many roles which include but not limited to custodians of the traditional African religion and customs, educators about culture, counselors, social workers and psychologists.

  19. LARGER PLANET RADII INFERRED FROM STELLAR ''FLICKER'' BRIGHTNESS VARIATIONS OF BRIGHT PLANET-HOST STARS

    SciTech Connect

    Bastien, Fabienne A.; Stassun, Keivan G.; Pepper, Joshua

    2014-06-10

    Most extrasolar planets have been detected by their influence on their parent star, typically either gravitationally (the Doppler method) or by the small dip in brightness as the planet blocks a portion of the star (the transit method). Therefore, the accuracy with which we know the masses and radii of extrasolar planets depends directly on how well we know those of the stars, the latter usually determined from the measured stellar surface gravity, log g. Recent work has demonstrated that the short-timescale brightness variations ({sup f}licker{sup )} of stars can be used to measure log g to a high accuracy of ∼0.1-0.2 dex. Here, we use flicker measurements of 289 bright (Kepmag < 13) candidate planet-hosting stars with T {sub eff} = 4500-6650 K to re-assess the stellar parameters and determine the resulting impact on derived planet properties. This re-assessment reveals that for the brightest planet-host stars, Malmquist bias contaminates the stellar sample with evolved stars: nearly 50% of the bright planet-host stars are subgiants. As a result, the stellar radii, and hence the radii of the planets orbiting these stars, are on average 20%-30% larger than previous measurements had suggested.

  20. Does Stevens's Power Law for Brightness Extend to Perceptual Brightness Averaging?

    ERIC Educational Resources Information Center

    Bauer, Ben

    2009-01-01

    Stevens's power law ([Psi][infinity][Phi][beta]) captures the relationship between physical ([Phi]) and perceived ([Psi]) magnitude for many stimulus continua (e.g., luminance and brightness, weight and heaviness, area and size). The exponent ([beta]) indicates whether perceptual magnitude grows more slowly than physical magnitude ([beta] less…

  1. Does Stevens's Power Law for Brightness Extend to Perceptual Brightness Averaging?

    ERIC Educational Resources Information Center

    Bauer, Ben

    2009-01-01

    Stevens's power law ([Psi][infinity][Phi][beta]) captures the relationship between physical ([Phi]) and perceived ([Psi]) magnitude for many stimulus continua (e.g., luminance and brightness, weight and heaviness, area and size). The exponent ([beta]) indicates whether perceptual magnitude grows more slowly than physical magnitude ([beta] less…

  2. Larger Planet Radii Inferred from Stellar "Flicker" Brightness Variations of Bright Planet-host Stars

    NASA Astrophysics Data System (ADS)

    Bastien, Fabienne A.; Stassun, Keivan G.; Pepper, Joshua

    2014-06-01

    Most extrasolar planets have been detected by their influence on their parent star, typically either gravitationally (the Doppler method) or by the small dip in brightness as the planet blocks a portion of the star (the transit method). Therefore, the accuracy with which we know the masses and radii of extrasolar planets depends directly on how well we know those of the stars, the latter usually determined from the measured stellar surface gravity, log g. Recent work has demonstrated that the short-timescale brightness variations ("flicker") of stars can be used to measure log g to a high accuracy of ~0.1-0.2 dex. Here, we use flicker measurements of 289 bright (Kepmag < 13) candidate planet-hosting stars with T eff = 4500-6650 K to re-assess the stellar parameters and determine the resulting impact on derived planet properties. This re-assessment reveals that for the brightest planet-host stars, Malmquist bias contaminates the stellar sample with evolved stars: nearly 50% of the bright planet-host stars are subgiants. As a result, the stellar radii, and hence the radii of the planets orbiting these stars, are on average 20%-30% larger than previous measurements had suggested.

  3. Silica-Rich Soil in Gusev Crater

    NASA Technical Reports Server (NTRS)

    2007-01-01

    NASA's Mars Exploration Rover Spirit has found a patch of bright-toned soil so rich in silica that scientists propose water must have been involved in concentrating it.

    The silica-rich patch, informally named 'Gertrude Weise' after a player in the All-American Girls Professional Baseball League, was exposed when Spirit drove over it during the 1,150th Martian day, or sol, of Spirit's Mars surface mission (March 29, 2007). One of Spirit's six wheels no longer rotates, so it leaves a deep track as it drags through soil. Most patches of disturbed, bright soil that Spirit had investigated previously are rich in sulfur, but this one has very little sulfur and is about 90 percent silica.

    Spirit's panoramic camera imaged the bright patch through various filters on Sol 1,158 (April 6). This approximately true-color image combines images taken through three different filters. The track of disturbed soil is roughly 20 centimeters (8 inches) wide.

    Spirit's miniature thermal emission spectrometer, which can assess a target's mineral composition from a distance, examined the Gertrude Weise patch on Sol 1,172 (April 20). The indications it found for silica in the overturned soil prompted a decision to drive Spirit close enough to touch the soil with the alpha particle X-ray spectrometer, a chemical analyzer at the end of Spirit's robotic arm. The alpha particle X-ray spectrometer collected data about this target on sols 1,189 and 1,190 (May 8 and May 9) and produced the finding of approximately 90 percent silica.

    Silica is silicon dioxide. On Earth, it commonly occurs as the crystalline mineral quartz and is the main ingredient in window glass. The Martian silica at Gertrude Weise is non-crystalline, with no detectable quartz.

    In most cases, water is required to produce such a concentrated deposit of silica, according to members of the rover science team. One possible origin for the silica could have been interaction of soil with acidic steam

  4. Silica-Rich Soil in Gusev Crater

    NASA Technical Reports Server (NTRS)

    2007-01-01

    NASA's Mars Exploration Rover Spirit has found a patch of bright-toned soil so rich in silica that scientists propose water must have been involved in concentrating it.

    The silica-rich patch, informally named 'Gertrude Weise' after a player in the All-American Girls Professional Baseball League, was exposed when Spirit drove over it during the 1,150th Martian day, or sol, of Spirit's Mars surface mission (March 29, 2007). One of Spirit's six wheels no longer rotates, so it leaves a deep track as it drags through soil. Most patches of disturbed, bright soil that Spirit had investigated previously are rich in sulfur, but this one has very little sulfur and is about 90 percent silica.

    Spirit's panoramic camera imaged the bright patch through various filters on Sol 1,158 (April 6). This approximately true-color image combines images taken through three different filters. The track of disturbed soil is roughly 20 centimeters (8 inches) wide.

    Spirit's miniature thermal emission spectrometer, which can assess a target's mineral composition from a distance, examined the Gertrude Weise patch on Sol 1,172 (April 20). The indications it found for silica in the overturned soil prompted a decision to drive Spirit close enough to touch the soil with the alpha particle X-ray spectrometer, a chemical analyzer at the end of Spirit's robotic arm. The alpha particle X-ray spectrometer collected data about this target on sols 1,189 and 1,190 (May 8 and May 9) and produced the finding of approximately 90 percent silica.

    Silica is silicon dioxide. On Earth, it commonly occurs as the crystalline mineral quartz and is the main ingredient in window glass. The Martian silica at Gertrude Weise is non-crystalline, with no detectable quartz.

    In most cases, water is required to produce such a concentrated deposit of silica, according to members of the rover science team. One possible origin for the silica could have been interaction of soil with acidic steam

  5. Hyperthymic temperament and rapid reaction time in brightness preference.

    PubMed

    Kodama, Kensuke; Harada, Mayu; Terao, Takeshi; Hatano, Koji; Kohno, Kentaro; Araki, Yasuo; Mizokami, Yoshinori; Hoaki, Nobuhiko; Shimomura, Tsuyoshi; Fujiki, Minoru; Kochiyama, Takanori

    2013-12-01

    It is well-known that Type A behavior pattern is characterized by hard-driving, competitive behavior and time urgency. Also, people with hyperthymic temperament are known to have high energy levels and are full of plans. It is therefore hypothesized that hyperthymic temperament is associated with rapid processing and fast reaction time in making decisions. Using data from our previous experimental studies (N=58) examining brightness judgment and brightness preference, reaction time (RT) was investigated in relation to hyperthymic temperament scores and fMRI signal changes of the left inferior orbitofrontal cortex during brightness judgment. RT for brightness judgment was significantly shorter than RT for brightness preference. Significant associations were found between RT for brightness preference and hyperthymic temperament scores, and RT for brightness preference and fMRI signal changes of the left inferior orbitofrontal cortex whilst performing brightness preference task. Multiple regression analysis revealed that RT for brightness preference task was significantly and negatively associated with hyperthymic temperament scores, and significantly and positively associated with fMRI signal changes of the left inferior orbitofrontal cortex. It is uncertain whether the findings of RT (around 1s) can be extrapolated to routine life (around 24h) and whether RT for brightness preference can be generalized to a variety of daily activities. The present findings suggest that hyperthymic temperament is associated with rapid processing. Further studies are required to overcome the above limitations. © 2013 Elsevier B.V. All rights reserved.

  6. Brightness and transparency in the early visual cortex.

    PubMed

    Salmela, Viljami R; Vanni, Simo

    2013-06-24

    Several psychophysical studies have shown that transparency can have drastic effects on brightness and lightness. However, the neural processes generating these effects have remained unresolved. Several lines of evidence suggest that the early visual cortex is important for brightness perception. While single cell recordings suggest that surface brightness is represented in the primary visual cortex, the results of functional magnetic resonance imaging (fMRI) studies have been discrepant. In addition, the location of the neural representation of transparency is not yet known. We investigated whether the fMRI responses in areas V1, V2, and V3 correlate with brightness and transparency. To dissociate the blood oxygen level-dependent (BOLD) response to brightness from the response to local border contrast and mean luminance, we used variants of White's brightness illusion, both opaque and transparent, in which luminance increments and decrements cancel each other out. The stimuli consisted of a target surface and a surround. The surround luminance was always sinusoidally modulated at 0.5 Hz to induce brightness modulation to the target. The target luminance was constant or modulated in counterphase to null brightness modulation. The mean signal changes were calculated from the voxels in V1, V2, and V3 corresponding to the retinotopic location of the target surface. The BOLD responses were significantly stronger for modulating brightness than for stimuli with constant brightness. In addition, the responses were stronger for transparent than for opaque stimuli, but there was more individual variation. No interaction between brightness and transparency was found. The results show that the early visual areas V1-V3 are sensitive to surface brightness and transparency and suggest that brightness and transparency are represented separately.

  7. Surface brightness and intrinsic luminosity of ellipticals

    NASA Astrophysics Data System (ADS)

    Dhar, Barun Kumar; Williams, Liliya L. R.

    2012-11-01

    We show that the surface brightness profiles of elliptical galaxies can be parametrized using a linear superposition of two or three components, each of which is described by functions developed in Dhar & Williams as the 2D projections of a 3D Einasto density profile. For a sample of 23 ellipticals in and around the Virgo Cluster with total absolute V magnitude -24 < MVT < -15, our multicomponent models span a dynamic range up to 106 in surface brightness and up to 105 in radius down to the resolution limit of the Hubble Space Telescope, have a median rms of 0.032 mag arcsec-2 consistent with the rms of 0.03 from random errors of the data, and are statistically justified at >3σ. Our models indicate that (i) the central component is more concentrated than the outer component; and (ii) the central component of massive shallow-cusp ('core') galaxies is much more luminous, extended and concentrated than that of steep-cusp ('cuspy') galaxies, with their near exponential central profiles indicating disc-like systems, whose existence must be verified spectroscopically. Galaxy structure can thus be modelled extremely well with a central mass excess for all galaxies. This is not necessarily contrary to the notion of a mass deficit in 'core' galaxies, since mass ejection due to core scouring by a supermassive black hole (SMBH) binary could have affected the shape of the central components. However, we show that the existence, amount, radial extent and sign of such deficits disagree substantially in the literature, both for a given galaxy and on an average over a sample. We discuss possible implications and suggest that SMBH binaries are unlikely to be the sole mechanism for producing the large 'cores' of massive galaxies. Using results from the SAURON survey, we deduce that under certain conditions of symmetry, inclination angles and degree of triaxiality, the intrinsic (3D) density of light can be well described with a multicomponent Einasto model for both steep- and

  8. Traditional Agriculture and Permaculture.

    ERIC Educational Resources Information Center

    Pierce, Dick

    1997-01-01

    Discusses benefits of combining traditional agricultural techniques with the concepts of "permaculture," a framework for revitalizing traditions, culture, and spirituality. Describes school, college, and community projects that have assisted American Indian communities in revitalizing sustainable agricultural practices that incorporate…

  9. Traditional Agriculture and Permaculture.

    ERIC Educational Resources Information Center

    Pierce, Dick

    1997-01-01

    Discusses benefits of combining traditional agricultural techniques with the concepts of "permaculture," a framework for revitalizing traditions, culture, and spirituality. Describes school, college, and community projects that have assisted American Indian communities in revitalizing sustainable agricultural practices that incorporate…

  10. High brightness angled cavity quantum cascade lasers

    SciTech Connect

    Heydari, D.; Bai, Y.; Bandyopadhyay, N.; Slivken, S.; Razeghi, M.

    2015-03-02

    A quantum cascade laser (QCL) with an output power of 203 W is demonstrated in pulsed mode at 283 K with an angled cavity. The device has a ridge width of 300 μm, a cavity length of 5.8 mm, and a tilt angle of 12°. The back facet is high reflection coated, and the front facet is anti-reflection coated. The emitting wavelength is around 4.8 μm. In distinct contrast to a straight cavity broad area QCL, the lateral far field is single lobed with a divergence angle of only 3°. An ultrahigh brightness value of 156 MW cm{sup −2 }sr{sup −1} is obtained, which marks the brightest QCL to date.

  11. Visualizing individual microtubules by bright field microscopy

    NASA Astrophysics Data System (ADS)

    Gutiérrez-Medina, Braulio; Block, Steven M.

    2010-11-01

    Microtubules are slender (˜25 nm diameter), filamentous polymers involved in cellular structure and organization. Individual microtubules have been visualized via fluorescence imaging of dye-labeled tubulin subunits and by video-enhanced, differential interference-contrast microscopy of unlabeled polymers using sensitive CCD cameras. We demonstrate the imaging of unstained microtubules using a microscope with conventional bright field optics in conjunction with a webcam-type camera and a light-emitting diode illuminator. The light scattered by microtubules is image-processed to remove the background, reduce noise, and enhance contrast. The setup is based on a commercial microscope with a minimal set of inexpensive components, suitable for implementation in a student laboratory. We show how this approach can be used in a demonstration motility assay, tracking the gliding motions of microtubules driven by the motor protein kinesin.

  12. Bright Solitonic Matter-Wave Interferometer

    NASA Astrophysics Data System (ADS)

    McDonald, G. D.; Kuhn, C. C. N.; Hardman, K. S.; Bennetts, S.; Everitt, P. J.; Altin, P. A.; Debs, J. E.; Close, J. D.; Robins, N. P.

    2014-07-01

    We present the first realization of a solitonic atom interferometer. A Bose-Einstein condensate of 1×104 atoms of rubidium-85 is loaded into a horizontal optical waveguide. Through the use of a Feshbach resonance, the s-wave scattering length of the Rb85 atoms is tuned to a small negative value. This attractive atomic interaction then balances the inherent matter-wave dispersion, creating a bright solitonic matter wave. A Mach-Zehnder interferometer is constructed by driving Bragg transitions with the use of an optical lattice colinear with the waveguide. Matter-wave propagation and interferometric fringe visibility are compared across a range of s-wave scattering values including repulsive, attractive and noninteracting values. The solitonic matter wave is found to significantly increase fringe visibility even compared with a noninteracting cloud.

  13. Dark Skies, Bright Kids Year 8

    NASA Astrophysics Data System (ADS)

    Bittle, Lauren E.; Wenger, Trey; Johnson, Kelsey E.; Angell, Dylan; Burkhardt, Andrew; Davis, Blair; Firebaugh, Ariel; Hancock, Danielle; Richardson, Whitney; Rochford Hayes, Christian; Linden, Sean; Liss, Sandra; Matthews, Allison; McNair, Shunlante; Prager, Brian; Pryal, Matthew; Troup, Nicholas William

    2017-01-01

    We present activities from the eighth year of Dark Skies Bright Kids (DSBK), an entirely volunteer-run outreach organization based out of the Department of Astronomy at the University of Virginia. Our core mission is to enhance elementary science education and literacy in Central Virginia through fun, hands-on activities that introduce basic Astronomy concepts. Over the past seven years, our primary focus has been hosting an 8-10 week after-school astronomy club at underserved elementary and middle schools, and over the past several years, we have partnered with local businesses to host our Annual Central Virginia Star Party, a free event open to the community featuring star-gazing and planetarium shows. This past summer we expanded our reach through a new initiative to bring week-long summer day camps to south and southwest Virginia, home to some of the most underserved communities in the commonwealth.

  14. High brightness angled cavity quantum cascade lasers

    NASA Astrophysics Data System (ADS)

    Heydari, D.; Bai, Y.; Bandyopadhyay, N.; Slivken, S.; Razeghi, M.

    2015-03-01

    A quantum cascade laser (QCL) with an output power of 203 W is demonstrated in pulsed mode at 283 K with an angled cavity. The device has a ridge width of 300 μm, a cavity length of 5.8 mm, and a tilt angle of 12°. The back facet is high reflection coated, and the front facet is anti-reflection coated. The emitting wavelength is around 4.8 μm. In distinct contrast to a straight cavity broad area QCL, the lateral far field is single lobed with a divergence angle of only 3°. An ultrahigh brightness value of 156 MW cm-2 sr-1 is obtained, which marks the brightest QCL to date.

  15. Infrared Sky Brightness Monitors for Antarctica

    NASA Astrophysics Data System (ADS)

    Storey, J. W. V.; Ashley, M. C. B.; Boccas, M.; Phillips, M. A.; Schinckel, A. E. T.

    1999-06-01

    Two sky brightness monitors-one for the near-infrared and one for the mid-infrared-have been developed for site survey work in Antarctica. The instruments, which we refer to as the NISM (Near-Infrared Sky Monitor) and the MISM (Mid-Infrared Sky Monitor), are part of a suite of instruments being deployed in the Automated Astrophysical Site-Testing Observatory (AASTO). The chief design constraints include reliable, autonomous operation, low power consumption, and of course the ability to operate under conditions of extreme cold. The instruments are currently operational at the Amundsen-Scott South Pole Station, prior to deployment at remote, unattended sites on the high antarctic plateau.

  16. Dark Skies, Bright Kids Year 7

    NASA Astrophysics Data System (ADS)

    Bittle, Lauren E.; Johnson, Kelsey E.; Borish, H. Jacob; Burkhardt, Andrew; Firebaugh, Ariel; Hancock, Danielle; Rochford Hayes, Christian; Linden, Sean; Liss, Sandra; Matthews, Allison; Prager, Brian; Pryal, Matthew; Sokal, Kimberly R.; Troup, Nicholas William; Wenger, Trey

    2016-01-01

    We present updates from our seventh year of operation including new club content, continued assessments, and our fifth annual Star Party. Dark Skies, Bright Kids (DSBK) is an entirely volunteer-run outreach organization based out of the Department of Astronomy at the University of Virginia. Our core mission is to enhance elementary science education and literacy in Central Virginia through fun, hands-on activities that introduce basic Astronomy concepts. Our primary focus is hosting an 8-10 week after-school astronomy club at underserved elementary and middle schools. Each week, DSBK volunteers take the role of coaches to introduce astronomy-related concepts ranging from the Solar System to galaxies to astrobiology, and to lead students in interactive learning activities. Another hallmark of DSBK is hosting our Annual Central Virginia Star Party, a free event open to the community featuring star-gazing and planetarium shows.

  17. Extinction and Sky Brightness at Dome C

    NASA Astrophysics Data System (ADS)

    Faurobert, M.; Arnaud, J.; Vernisse, Y.

    2012-06-01

    We have installed a small telescope to monitor the sky brightness around the sun at the French-Italian station Concordia at Dome C in Antarctica. Previous campaigns have been performed with the same instrument at Haleakala in Hawai and Sunspot in New Mexico. We compare here the results of the first year of the campaign at Dome C (2008) to the purest sky observed at Haleakala. We show that Dome C is an outstanding site for coronal observations. Compared to Haleaka, it appears to be more transparent, and to contain less aerosols. Its water vapour content is also significantly smaller. These results still have to be confirmed by the analysis of the 2009 and 2010 data.

  18. Bioinspired bright noniridescent photonic melanin supraballs

    PubMed Central

    Xiao, Ming; Hu, Ziying; Wang, Zhao; Li, Yiwen; Tormo, Alejandro Diaz; Le Thomas, Nicolas; Wang, Boxiang; Gianneschi, Nathan C.; Shawkey, Matthew D.; Dhinojwala, Ali

    2017-01-01

    Structural colors enable the creation of a spectrum of nonfading colors without pigments, potentially replacing toxic metal oxides and conjugated organic pigments. However, significant challenges remain to achieve the contrast needed for a complete gamut of colors and a scalable process for industrial application. We demonstrate a feasible solution for producing structural colors inspired by bird feathers. We have designed core-shell nanoparticles using high–refractive index (RI) (~1.74) melanin cores and low-RI (~1.45) silica shells. The design of these nanoparticles was guided by finite-difference time-domain simulations. These nanoparticles were self-assembled using a one-pot reverse emulsion process, which resulted in bright and noniridescent supraballs. With the combination of only two ingredients, synthetic melanin and silica, we can generate a full spectrum of colors. These supraballs could be directly added to paints, plastics, and coatings and also used as ultraviolet-resistant inks or cosmetics. PMID:28929137

  19. Bioinspired bright noniridescent photonic melanin supraballs.

    PubMed

    Xiao, Ming; Hu, Ziying; Wang, Zhao; Li, Yiwen; Tormo, Alejandro Diaz; Le Thomas, Nicolas; Wang, Boxiang; Gianneschi, Nathan C; Shawkey, Matthew D; Dhinojwala, Ali

    2017-09-01

    Structural colors enable the creation of a spectrum of nonfading colors without pigments, potentially replacing toxic metal oxides and conjugated organic pigments. However, significant challenges remain to achieve the contrast needed for a complete gamut of colors and a scalable process for industrial application. We demonstrate a feasible solution for producing structural colors inspired by bird feathers. We have designed core-shell nanoparticles using high-refractive index (RI) (~1.74) melanin cores and low-RI (~1.45) silica shells. The design of these nanoparticles was guided by finite-difference time-domain simulations. These nanoparticles were self-assembled using a one-pot reverse emulsion process, which resulted in bright and noniridescent supraballs. With the combination of only two ingredients, synthetic melanin and silica, we can generate a full spectrum of colors. These supraballs could be directly added to paints, plastics, and coatings and also used as ultraviolet-resistant inks or cosmetics.

  20. Modelling Solar and Stellar Brightness Variabilities

    NASA Astrophysics Data System (ADS)

    Yeo, K. L.; Shapiro, A. I.; Krivova, N. A.; Solanki, S. K.

    2016-04-01

    Total and spectral solar irradiance, TSI and SSI, have been measured from space since 1978. This is accompanied by the development of models aimed at replicating the observed variability by relating it to solar surface magnetism. Despite significant progress, there remains persisting controversy over the secular change and the wavelength-dependence of the variation with impact on our understanding of the Sun's influence on the Earth's climate. We highlight the recent progress in TSI and SSI modelling with SATIRE. Brightness variations have also been observed for Sun-like stars. Their analysis can profit from knowledge of the solar case and provide additional constraints for solar modelling. We discuss the recent effort to extend SATIRE to Sun-like stars.

  1. Developing High Brightness and High Current Beams for HIF Injectors

    SciTech Connect

    Ahle, L; Kwan, J W

    2002-05-10

    The US Heavy Ion Fusion Virtual National Laboratory is continuing research into ion sources and injectors that simultaneously provide high current (0.5-1.0 Amps) and high brightness (normalized emittance better than 1.0 {pi}-mm-mr). The central issue of focus is whether to carry on the traditional approach of large surface ionization sources or to adopt a multi-aperture approach that transports many smaller ''beamlets'' separately at low energies before allowing them to merge. For the large surface source, the recent commissioning of the 2-MeV injector for the High Current experiment has increased our understanding of the beam quality limitations for these sources. We have also improved our techniques for fabricating large diameter aluminosilicate sources to improve lifetime and emission uniformity. For the multi-aperture approach we are continuing to study the feasibility of small surface sources and a RF induced plasma source in preparation for beamlet merging experiments, while continuing to run computer simulations for better understanding of this alternate concept. Experiments into both architectures will be performed on a newly commissioned ion source test stand at LLNL called the STS-500. This stand test provides a platform for testing a variety of ion sources and accelerating structures with 500 kV, 17-microsecond pulses. Recent progress in these areas will be discussed as well as plans for future experiments.

  2. Developing high brightness and high current beams for HIF injectors

    SciTech Connect

    Ahle, Larry; Grote, Dave; Kwan, Joe

    2002-05-24

    The US Heavy Ion Fusion Virtual National Laboratory is continuing research into ion sources and injectors that simultaneously provide high current (0.5-1.0 Amps) and high brightness (normalized emittance better than 1.0 {pi}-mm-mr). The central issue of focus is whether to continue pursuing the traditional approach of large surface ionization sources or to adopt a multiaperture approach that transports many smaller ''beamlets'' separately at low energies before allowing them to merge. For the large surface source concept, the recent commissioning of the 2-MeV injector for the High Current eXperiment has increased our understanding of the beam quality limitations for these sources. We have also improved our techniques for fabricating large diameter aluminosilicate sources to improve lifetime and emission uniformity. For the multiaperture approach, we are continuing to study the feasibility of small surface sources and a RF induced plasma source in preparation for beamlet merging experiments, while continuing to run computer simulations for better understanding of this alternate concept. Experiments into both architectures will be performed on a newly commissioned ion source test stand at LLNL called STS-500. This stand test provides a platform for testing a variety of ion sources and accelerating structures with 500 kV, 17-microsecond pulses. Recent progress in these areas will be discussed as well as plans for future experiments.

  3. Trailed Spectra of Bright Spectrophotometric Standard Stars

    NASA Astrophysics Data System (ADS)

    Pitts, Ronald E.

    The IUE archives is an extensive and growing database of UV spectra of a wide variety of astronomical objects. The usefulness of the archives will be greatly enhanced by the presence of a number of wellobserved standard stars including those which define the visual wavelength absolute flux calibrations. Observation of ground-based spectrophotometric standards by IUE will be useful for providing a selfconsistent flux calibration for bright stars and for permitting direct comparisons with fainter standards for future missions, already in the archives, on the IUE system. New observing techniques now make it possible for IUE to obtain well-exposed spectra of these bright stars. However, this observing method is one of the few which may not be possible if IUE were to lose another gyro and the backup control mode, now under development, were used. We propose to obtain short and long wavelength spectra for four of the brightest spectrophotometric standard stars which have either not been observed with with IUE or are poorly represented in the IUE archives. Over a number of years these stars have been observed and defined as standards by a number of ground based observers including Oke(1964), Breger (1976), Stone(1977), Oke and Gunn (1983), and Taylor (1984). The primary standard has been Vega with 109 Vir as an alternate (Davis Philip and Hayes 1984). By combining trailed and point source spectra, ultraviolet absolute flux distributions will be obtained for the 1200-3200 A interval. A comparison will be made of Alpha Lyr and 109 Vir with the nearby star Alpha CMA A, which has a well-determined distance and measured radius. The suspected low-level intermittent variability of Alpha Lyr is not believed to pose major problems for our analysis.

  4. Statistical Properties of Solar Coronal Bright Points

    NASA Astrophysics Data System (ADS)

    Alipour, N.; Safari, H.

    2015-07-01

    Here, we aim to study the statistical properties (i.e., spatial, temporal, and magnetic structures) of extreme ultraviolet coronal bright points (CBPs) observed by SDO during a 4.4 yr period (2010 June 1 to 2014 October 31). We developed the automatic detection method for CBPs based on the machine-learning technique and Zernike image moments. The average number and the mean density of CBPs are estimated to be about 572 (per full disk image taken at 193 Å) and 1.9× {10}-4 Mm-2, respectively. There is a negative correlation (-0.7) between the number of CBPs and the number of sunspots. The size and lifetime frequency distribution of CBPs show the lognormal and power-law (exponent equal to -1.6) behaviors, respectively. The relationship between the lifetime and size of CBPs is clearly treated by a power-law function with an exponent equal to 0.13. Around 1.3% of the solar surface is covered by the bright cores of CBPs and 2.6% of that is covered by their total area. About 52% of CBPs have lifetimes of less than 20 minutes and the remaining 48% have mean lifetimes of 6 hr. More than 95% of CBPs with lifetimes of less than 20 hr and nine CBPs with lifetimes of more than 72 hr are detected. The average number of the new CBPs emerging every 45 s in the whole of the Sun is about 27 ± 3. The temporal self-affinity of the time series of CBPs that emerged, indexed by the Hurst exponent determined using both detrended fluctuation analysis and R/S analysis, is 0.78. This long-temporal correlation suggests that CBPs form a system of self-organized criticality.

  5. The GPM Common Calibrated Brightness Temperature Product

    NASA Technical Reports Server (NTRS)

    Stout, John; Berg, Wesley; Huffman, George; Kummerow, Chris; Stocker, Erich

    2005-01-01

    The Global Precipitation Measurement (GPM) project will provide a core satellite carrying the GPM Microwave Imager (GMI) and will use microwave observations from a constellation of other satellites. Each partner with a satellite in the constellation will have a calibration that meets their own requirements and will decide on the format to archive their brightness temperature (Tb) record in GPM. However, GPM multi-sensor precipitation algorithms need to input intercalibrated Tb's in order to avoid differences among sensors introducing artifacts into the longer term climate record of precipitation. The GPM Common Calibrated Brightness Temperature Product is intended to address this problem by providing intercalibrated Tb data, called "Tc" data, where the "c" stands for common. The precipitation algorithms require a Tc file format that is both generic and flexible enough to accommodate the different passive microwave instruments. The format will provide detailed information on the processing history in order to allow future researchers to have a record of what was done. The format will be simple, including the main items of scan time, latitude, longitude, and Tc. It will also provide spacecraft orientation, spacecraft location, orbit, and instrument scan type (cross-track or conical). Another simplification is to store data in real numbers, avoiding the ambiguity of scaled data. Finally, units and descriptions will be provided in the product. The format is built on the concept of a swath, which is a series of scans that have common geolocation and common scan geometry. Scan geometry includes pixels per scan, sensor orientation, scan type, and incidence angles. The Tc algorithm and data format are being tested using the pre-GPM Precipitation Processing System (PPS) software to generate formats and 1/0 routines. In the test, data from SSM/I, TMI, AMSR-E, and WindSat are being processed and written as Tc products.

  6. The GPM Common Calibrated Brightness Temperature Product

    NASA Technical Reports Server (NTRS)

    Stout, John; Berg, Wesley; Huffman, George; Kummerow, Chris; Stocker, Erich

    2005-01-01

    The Global Precipitation Measurement (GPM) project will provide a core satellite carrying the GPM Microwave Imager (GMI) and will use microwave observations from a constellation of other satellites. Each partner with a satellite in the constellation will have a calibration that meets their own requirements and will decide on the format to archive their brightness temperature (Tb) record in GPM. However, GPM multi-sensor precipitation algorithms need to input intercalibrated Tb's in order to avoid differences among sensors introducing artifacts into the longer term climate record of precipitation. The GPM Common Calibrated Brightness Temperature Product is intended to address this problem by providing intercalibrated Tb data, called "Tc" data, where the "c" stands for common. The precipitation algorithms require a Tc file format that is both generic and flexible enough to accommodate the different passive microwave instruments. The format will provide detailed information on the processing history in order to allow future researchers to have a record of what was done. The format will be simple, including the main items of scan time, latitude, longitude, and Tc. It will also provide spacecraft orientation, spacecraft location, orbit, and instrument scan type (cross-track or conical). Another simplification is to store data in real numbers, avoiding the ambiguity of scaled data. Finally, units and descriptions will be provided in the product. The format is built on the concept of a swath, which is a series of scans that have common geolocation and common scan geometry. Scan geometry includes pixels per scan, sensor orientation, scan type, and incidence angles. The Tc algorithm and data format are being tested using the pre-GPM Precipitation Processing System (PPS) software to generate formats and 1/0 routines. In the test, data from SSM/I, TMI, AMSR-E, and WindSat are being processed and written as Tc products.

  7. CME Brightness at Large Elongations: Application to LASCO and SMEI Observations

    NASA Astrophysics Data System (ADS)

    Vourlidas, A.; Webb, D. F.; Morrill, J. S.; Jackson, B. V.

    2006-12-01

    The traditional analysis of the CME brightness relied on the assumption that all lines of sight through the CME were parallel due to the large distance between the observer and the event. However, this assumption is not correct when CME observations at large distances from the Sun are concerned. In a recent paper (Vourlidas & Howard 2006) we have outlined the proper geometry and presented a few theoretical predictions about the brightness evolution of CME launched at various angles relative to the Sun-observer line. In this talk, we use LASCO and SMEI observations of the same events to test our predictions and see how we can use our theoretical framework to interpret the observed CME structures.

  8. The night sky brightness at McDonald Observatory

    NASA Technical Reports Server (NTRS)

    Kalinowski, J. K.; Roosen, R. G.; Brandt, J. C.

    1975-01-01

    Baseline observations of the night sky brightness in B and V are presented for McDonald Observatory. In agreement with earlier work by Elvey and Rudnick (1937) and Elvey (1943), significant night-to-night and same-night variations in sky brightness are found. Possible causes for these variations are discussed. The largest variation in sky brightness found during a single night is approximately a factor of two, a value which corresponds to a factor-of-four variation in airglow brightness. The data are used to comment on the accuracy of previously published surface photometry of M 81.

  9. Investigation of the moving structures in a coronal bright point

    SciTech Connect

    Ning, Zongjun; Guo, Yang

    2014-10-10

    We have explored the moving structures in a coronal bright point (CBP) observed by the Solar Dynamic Observatory Atmospheric Imaging Assembly (AIA) on 2011 March 5. This CBP event has a lifetime of ∼20 minutes and is bright with a curved shape along a magnetic loop connecting a pair of negative and positive fields. AIA imaging observations show that a lot of bright structures are moving intermittently along the loop legs toward the two footpoints from the CBP brightness core. Such moving bright structures are clearly seen at AIA 304 Å. In order to analyze their features, the CBP is cut along the motion direction with a curved slit which is wide enough to cover the bulk of the CBP. After integrating the flux along the slit width, we get the spacetime slices at nine AIA wavelengths. The oblique streaks starting from the edge of the CBP brightness core are identified as moving bright structures, especially on the derivative images of the brightness spacetime slices. They seem to originate from the same position near the loop top. We find that these oblique streaks are bi-directional, simultaneous, symmetrical, and periodic. The average speed is about 380 km s{sup –1}, and the period is typically between 80 and 100 s. Nonlinear force-free field extrapolation shows the possibility that magnetic reconnection takes place during the CBP, and our findings indicate that these moving bright structures could be the observational outflows after magnetic reconnection in the CBP.

  10. The CBM RICH detector

    NASA Astrophysics Data System (ADS)

    Adamczewski-Musch, J.; Akishin, P.; Becker, K.-H.; Belogurov, S.; Bendarouach, J.; Boldyreva, N.; Chernogorov, A.; Deveaux, C.; Dobyrn, V.; Dürr, M.; Eschke, J.; Förtsch, J.; Heep, J.; Höohne, C.; Kampert, K.-H.; Kochenda, L.; Kopfer, J.; Kravtsov, P.; Kres, I.; Lebedev, S.; Lebedeva, E.; Leonova, E.; Linev, S.; Mahmoud, T.; Michel, J.; Miftakhov, N.; Niebur, W.; Ovcharenko, E.; Pauly, C.; Pfeifer, D.; Querchfeld, S.; Rautenberg, J.; Reinecke, S.; Riabov, Y.; Roshchin, E.; Samsonov, V.; Tarasenkova, O.; Traxler, M.; Ugur, C.; Vznuzdaev, E.; Vznuzdaev, M.

    2016-05-01

    The CBM RICH detector will use CO2 as radiator gas, focussing glass mirrors with Al+MgF2 reflective and protective coating and Hamamatsu H12700 MAPMTs as photon detectors. The detector will serve for electron to pion separation up to momenta of 8 GeV/c and thus enable in CBM the measurement of electromagnetic radiation from the early and dense fireball in A+A collisions at SIS 100. In this article, the current status of the CBM RICH development will be presented including new measurements of the radiation hardness of the H12700 MAPMT and WLS coatings with p-terphenyl, the new concept for the readout electronics, and optimizations ongoing with respect to the mirror mount structure and overall geometry. Prior to the usage in CBM, part of the already ordered MAPMTs will be used to upgrade the HADES RICH detector for a new measurement campaign at SIS 18 from 2018-2020.

  11. Hydrogen rich gas generator

    NASA Technical Reports Server (NTRS)

    Houseman, J.; Rupe, J. H.; Kushida, R. O. (Inventor)

    1976-01-01

    A process and apparatus is described for producing a hydrogen rich gas by injecting air and hydrocarbon fuel at one end of a cylindrically shaped chamber to form a mixture and igniting the mixture to provide hot combustion gases by partial oxidation of the hydrocarbon fuel. The combustion gases move away from the ignition region to another region where water is injected to be turned into steam by the hot combustion gases. The steam which is formed mixes with the hot gases to yield a uniform hot gas whereby a steam reforming reaction with the hydrocarbon fuel takes place to produce a hydrogen rich gas.

  12. Controlled formation and reflection of a bright solitary matter-wave

    PubMed Central

    Marchant, A. L.; Billam, T. P.; Wiles, T. P.; Yu, M. M. H.; Gardiner, S. A.; Cornish, S. L.

    2013-01-01

    Bright solitons are non-dispersive wave solutions, arising in a diverse range of nonlinear, one-dimensional systems, including atomic Bose–Einstein condensates with attractive interactions. In reality, cold-atom experiments can only approach the idealized one-dimensional limit necessary for the realization of true solitons. Nevertheless, it remains possible to create bright solitary waves, the three-dimensional analogue of solitons, which maintain many of the key properties of their one-dimensional counterparts. Such solitary waves offer many potential applications and provide a rich testing ground for theoretical treatments of many-body quantum systems. Here we report the controlled formation of a bright solitary matter-wave from a Bose–Einstein condensate of 85Rb, which is observed to propagate over a distance of ∼1.1 mm in 150 ms with no observable dispersion. We demonstrate the reflection of a solitary wave from a repulsive Gaussian barrier and contrast this to the case of a repulsive condensate, in both cases finding excellent agreement with theoretical simulations using the three-dimensional Gross–Pitaevskii equation. PMID:23673650

  13. The distribution of star formation and metals in the low surface brightness galaxy UGC 628

    NASA Astrophysics Data System (ADS)

    Young, J. E.; Kuzio de Naray, Rachel; Wang, Sharon X.

    2015-09-01

    We introduce the MUSCEL Programme (MUltiwavelength observations of the Structure, Chemistry and Evolution of LSB galaxies), a project aimed at determining the star-formation histories of low surface brightness galaxies. MUSCEL utilizes ground-based optical spectra and space-based UV and IR photometry to fully constrain the star-formation histories of our targets with the aim of shedding light on the processes that led low surface brightness galaxies down a different evolutionary path from that followed by high surface brightness galaxies, such as our Milky Way. Here we present the spatially resolved optical spectra of UGC 628, observed with the VIRUS-P IFU at the 2.7-m Harlen J. Smith Telescope at the McDonald Observatory, and utilize emission-line diagnostics to determine the rate and distribution of star formation as well as the gas-phase metallicity and metallicity gradient. We find highly clustered star formation throughout UGC 628, excluding the core regions, and a log(O/H) metallicity around -4.2, with more metal-rich regions near the edges of the galactic disc. Based on the emission-line diagnostics alone, the current mode of star formation, slow and concentrated in the outer disc, appears to have dominated for quite some time, although there are clear signs of a much older stellar population formed in a more standard inside-out fashion.

  14. Controlled formation and reflection of a bright solitary matter-wave.

    PubMed

    Marchant, A L; Billam, T P; Wiles, T P; Yu, M M H; Gardiner, S A; Cornish, S L

    2013-01-01

    Bright solitons are non-dispersive wave solutions, arising in a diverse range of nonlinear, one-dimensional systems, including atomic Bose-Einstein condensates with attractive interactions. In reality, cold-atom experiments can only approach the idealized one-dimensional limit necessary for the realization of true solitons. Nevertheless, it remains possible to create bright solitary waves, the three-dimensional analogue of solitons, which maintain many of the key properties of their one-dimensional counterparts. Such solitary waves offer many potential applications and provide a rich testing ground for theoretical treatments of many-body quantum systems. Here we report the controlled formation of a bright solitary matter-wave from a Bose-Einstein condensate of (85)Rb, which is observed to propagate over a distance of ∼1.1 mm in 150 ms with no observable dispersion. We demonstrate the reflection of a solitary wave from a repulsive Gaussian barrier and contrast this to the case of a repulsive condensate, in both cases finding excellent agreement with theoretical simulations using the three-dimensional Gross-Pitaevskii equation.

  15. Effects of Early Bright, Late Bright and Dim Illumination upon Circadian Neuroendocrine, Electrophysiological and Behavioral Responses

    DTIC Science & Technology

    1992-07-29

    Electrophysiological and Behavioral Measures. 19. on the Stanford Sleep Scale from 2400 hrs through 0500 hrs (light x time, F= 2.595, p=.02 3...scores on the Stanford Sleep Scale from 2400 hrs through 0500 hrs (light x time, F= 2.595, p=.023). Subjects under the bright light conditions performed...serious safety problem. Night shift personnel and task managers (eg. military officers and skilled military labor) who manage their sleep schedule

  16. The relation between isolated tree brightness temperature and grass background brightness temperature

    NASA Astrophysics Data System (ADS)

    Krusinger, A. E.

    1983-08-01

    This study involves thermal infrared measurement for the determination of the diurnal and seasonal aspects of the relations between isolated evergreen tress and a cut grass background and between a large truck brightness temperature and cut grass, uncut grass, and bare soil backgrounds. Seasonal changes in the tree brightness temperature-background brightness temperature contrast ranged from 4 to 5 C in February and March to 1 to 2 C in July. At night, the thermal contrast between trees and background was found to vary inversely with long wave incoming radiation, which is a measure of cloudiness. A study of the change in the thermal contrast during the night showed that, during clear weather, the contrast was at a peak a few hours after sundown and decreased the rest of the night. In overcast conditions, a reduced contrast peak occurred at sundown and very gradually diminished through the night. Isothermal conditions were found to occur in the early mornings, and the time of these occurrences changed seasonally, in a systematic manner.

  17. High Brightness Neutron Source for Radiography

    SciTech Connect

    Cremer, J. T.; Piestrup, Melvin, A.; Gary, Charles, K.; Harris, Jack, L. Williams, David, J.; Jones, Glenn, E.; Vainionpaa, J. , H.; Fuller, Michael, J.; Rothbart, George, H.; Kwan, J., W.; Ludewigt, B., A.; Gough, R.., A..; Reijonen, Jani; Leung, Ka-Ngo

    2008-12-08

    This research and development program was designed to improve nondestructive evaluation of large mechanical objects by providing both fast and thermal neutron sources for radiography. Neutron radiography permits inspection inside objects that x-rays cannot penetrate and permits imaging of corrosion and cracks in low-density materials. Discovering of fatigue cracks and corrosion in piping without the necessity of insulation removal is possible. Neutron radiography sources can provide for the nondestructive testing interests of commercial and military aircraft, public utilities and petrochemical organizations. Three neutron prototype neutron generators were designed and fabricated based on original research done at the Lawrence Berkeley National Laboratory (LBNL). The research and development of these generators was successfully continued by LBNL and Adelphi Technology Inc. under this STTR. The original design goals of high neutron yield and generator robustness have been achieved, using new technology developed under this grant. In one prototype generator, the fast neutron yield and brightness was roughly 10 times larger than previously marketed neutron generators using the same deuterium-deuterium reaction. In another generator, we integrate a moderator with a fast neutron source, resulting in a high brightness thermal neutron generator. The moderator acts as both conventional moderator and mechanical and electrical support structure for the generator and effectively mimics a nuclear reactor. In addition to the new prototype generators, an entirely new plasma ion source for neutron production was developed. First developed by LBNL, this source uses a spiral antenna to more efficiently couple the RF radiation into the plasma, reducing the required gas pressure so that the generator head can be completely sealed, permitting the possible use of tritium gas. This also permits the generator to use the deuterium-tritium reaction to produce 14-MeV neutrons with increases

  18. Discovery of a bright eclipsing cataclysmic variable

    NASA Astrophysics Data System (ADS)

    Sing, D. K.; Green, E. M.; Howell, S. B.; Holberg, J. B.; Lopez-Morales, M.; Shaw, J. S.; Schmidt, G. D.

    2007-11-01

    Aims:We report on the discovery of J0644+3344, a bright, deeply-eclipsing cataclysmic variable (CV) binary. Methods: Optical photometric and spectroscopic observations were obtained to determine the nature and characteristics of this CV. Results: Spectral signatures of both binary components and an accretion disk can be seen at optical wavelengths. The optical spectrum shows broad H I, He I, and He II accretion disk emission lines with deep narrow absorption components from H I, He I, Mg II, and Ca II. The absorption lines are seen throughout the orbital period, disappearing only during primary eclipse. These absorption lines are either the result of an optically-thick inner accretion disk or from the photosphere of the primary star. Radial velocity measurements show that the H I, He I, and Mg II absorption lines phase with the primary star, while weak absorption features in the continuum, between Hα and Hβ, phase with the secondary star. Radial velocity solutions give a 150±4 km s-1 semi-amplitude for the primary star and 192.8±5.6 km s-1 for the secondary, resulting in a primary to secondary mass ratio of q = 1.285. The individual stellar masses are 0.63-0.69 M⊙ for the primary and 0.49-0.54 M⊙ for the secondary, with the uncertainty largely due to the inclination. Conclusions: The bright eclipsing nature of this binary has helped provide masses for both components with an accuracy rarely achieved for CVs. This binary most closely resembles a nova-like UX UMa or SW Sex type of CV. J0644+3344, however, has a longer orbital period than most UX UMa or SW Sex stars. Assuming an evolution toward shorter orbital periods, J0644+3344 is therefore likely to be a young interacting binary. The secondary star is consistent with the size and spectral type of a K8 star, but has the mass of a M0.

  19. From Rags to Riches

    ERIC Educational Resources Information Center

    Sweet, Colleen

    2008-01-01

    In this article, the author presents the "Rags to Riches" design project she introduced to her students. She assigned each of her students one item from an array to thrift store goods which included old scarves, sweaters, jackets, and even evening gowns. The design problem was to imagine what a clothing tag might look like if the assigned item…

  20. From Rags to Riches

    ERIC Educational Resources Information Center

    Sweet, Colleen

    2008-01-01

    In this article, the author presents the "Rags to Riches" design project she introduced to her students. She assigned each of her students one item from an array to thrift store goods which included old scarves, sweaters, jackets, and even evening gowns. The design problem was to imagine what a clothing tag might look like if the assigned item…

  1. Mangrove bacterial richness

    PubMed Central

    Cleary, Daniel FR; Calado, Ricardo; Costa, Rodrigo

    2011-01-01

    Mangroves are complex and dynamic ecosystems varying in salinity, water level and nutrient availability; they also contain diverse and distinct microbial communities. Studies of microbes and their interactions with other ecosystem components (e.g., tree roots) are critical for our understanding of mangrove ecosystem functioning and remediation. Using a barcoding pyrosequencing approach, we previously noted the persistence of terrestrial bacterial populations on mangrove roots when nursery raised saplings were transplanted back to their natural environment. Here we go into further detail about the potential functional associations of bacterial guilds with distinct mangrove microhabitats including the rhizosphere. We also use a nonparametric richness estimator to show that estimated operational taxonomic unit (OTU) richness is more than twice that observed. In the transplant microhabitat, our estimate suggests that there are almost 7,000 OTU's for a sample size of 10,400 individual sequences with no sign of an asymptote, indicating that “true” richness for this microhabitat is substantially larger. Results on the number of bacterial OTU's should, however, be viewed with caution given that the barcoding pyrosequencing technique used can yield sequencing artifacts that may inflate richness estimates if not properly removed. PMID:21966560

  2. Thinking about "Rich" Tasks

    ERIC Educational Resources Information Center

    Box, Lorna; Watson, Anne

    2010-01-01

    This article presents an e-mail conversation between two teachers discussing how to have a "rich task" lesson in which they get to the heart of mathematical modeling and in which students are motivated into working on mathematics. One teacher emphasizes that the power of maths is in developing mathematical descriptions of situations by…

  3. Thinking about "Rich" Tasks

    ERIC Educational Resources Information Center

    Box, Lorna; Watson, Anne

    2010-01-01

    This article presents an e-mail conversation between two teachers discussing how to have a "rich task" lesson in which they get to the heart of mathematical modeling and in which students are motivated into working on mathematics. One teacher emphasizes that the power of maths is in developing mathematical descriptions of situations by…

  4. An Alternative Representation of the Ice Canopy for Calculating Microwave Brightness Temperatures over a Thunderstorm.

    NASA Astrophysics Data System (ADS)

    Muller, Bradley M.; Fuelberg, Henry E.; Smith, Eric A.

    1993-05-01

    Passive microwave brightness temperatures (TB's) at 92 and 183 GHz from an aircraft thunderstorm overflight are compared with values calculated from radar-derived hydrometer profiles and a modified proximity sounding. Two methods for modeling particles in the ice canopy are contrasted. The fist is a `traditional' approach employing Marshall Palmer ice spheres. The second, or `alternative,' method partitions 20% of the ice water content into a Marshall Palmer component for graupel and hail, and 80% into a modified gamma spherical particle size distribution function representing ice crystals.Results from the alternative approach are superior to those from the traditional method in the anvil and mature convective core. In the decaying convective region, the traditional approach yields better agreement with observed magnitude. Neither method, however, matches the geometry of the observed TB depression associated with the decaying convective core. This is likely due to the presence of graupel, which is not detected as a special signature in radar reflectivity, but does diminish TB's through scattering. Brightness temperatures at the relatively high microwave frequencies considered are shown to be very sensitive to the ice-particle size distribution.

  5. On the Classification of UGC 1382 as a Giant Low Surface Brightness Galaxy

    NASA Astrophysics Data System (ADS)

    Hagen, Lea M. Z.; Seibert, Mark; Hagen, Alex; Nyland, Kristina; Neill, James D.; Treyer, Marie; Young, Lisa M.; Rich, Jeffrey A.; Madore, Barry F.

    2016-08-01

    We provide evidence that UGC 1382, long believed to be a passive elliptical galaxy, is actually a giant low surface brightness (GLSB) galaxy that rivals the archetypical GLSB Malin 1 in size. Like other GLSB galaxies, it has two components: a high surface brightness disk galaxy surrounded by an extended low surface brightness (LSB) disk. For UGC 1382, the central component is a lenticular system with an effective radius of 6 kpc. Beyond this, the LSB disk has an effective radius of ˜38 kpc and an extrapolated central surface brightness of ˜26 mag arcsec-2. Both components have a combined stellar mass of ˜8 × 1010 M ⊙, and are embedded in a massive (1010 M ⊙) low-density (<3 M ⊙ pc-2) HI disk with a radius of 110 kpc, making this one of the largest isolated disk galaxies known. The system resides in a massive dark matter halo of at least 2 × 1012 M ⊙. Although possibly part of a small group, its low-density environment likely plays a role in the formation and retention of the giant LSB and HI disks. We model the spectral energy distributions and find that the LSB disk is likely older than the lenticular component. UGC 1382 has UV-optical colors typical of galaxies transitioning through the green valley. Within the LSB disk are spiral arms forming stars at extremely low efficiencies. The gas depletion timescale of ˜1011 years suggests that UGC 1382 may be a very-long-term resident of the green valley. We find that the formation and evolution of the LSB disk in UGC 1382 is best explained by the accretion of gas-rich LSB dwarf galaxies.

  6. 7 CFR 51.2000 - Clean and bright.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Clean and bright. 51.2000 Section 51.2000 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Standards for Grades of Filberts in the Shell 1 Definitions § 51.2000 Clean and bright. Clean and...

  7. 7 CFR 51.2000 - Clean and bright.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Clean and bright. 51.2000 Section 51.2000 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Standards for Grades of Filberts in the Shell 1 Definitions § 51.2000 Clean and bright. Clean and...

  8. 7 CFR 51.2000 - Clean and bright.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Clean and bright. 51.2000 Section 51.2000 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Standards for Grades of Filberts in the Shell 1 Definitions § 51.2000 Clean and bright. Clean and...

  9. Analysis of Bright Harvest Remote Analysis for Residential Solar Installations

    SciTech Connect

    Nangle, John; Simon, Joseph

    2015-06-17

    Bright Harvest provides remote shading analysis and design products for residential PV system installers. The National Renewable Energy Laboratory (NREL) through the NREL Commercialization Assistance Program, completed comparative assessments between on-site measurements and remotely calculated values to validate the accuracy of Bright Harvest’s remote shading and power generation.

  10. Spatial Model of Sky Brightness Magnitude in Langkawi Island, Malaysia

    NASA Astrophysics Data System (ADS)

    Redzuan Tahar, Mohammad; Kamarudin, Farahana; Umar, Roslan; Khairul Amri Kamarudin, Mohd; Sabri, Nor Hazmin; Ahmad, Karzaman; Rahim, Sobri Abdul; Sharul Aikal Baharim, Mohd

    2017-03-01

    Sky brightness is an essential topic in the field of astronomy, especially for optical astronomical observations that need very clear and dark sky conditions. This study presents the spatial model of sky brightness magnitude in Langkawi Island, Malaysia. Two types of Sky Quality Meter (SQM) manufactured by Unihedron are used to measure the sky brightness on a moonless night (or when the Moon is below the horizon), when the sky is cloudless and the locations are at least 100 m from the nearest light source. The selected locations are marked by their GPS coordinates. The sky brightness data obtained in this study were interpolated and analyzed using a Geographic Information System (GIS), thus producing a spatial model of sky brightness that clearly shows the dark and bright sky areas in Langkawi Island. Surprisingly, our results show the existence of a few dark sites nearby areas of high human activity. The sky brightness of 21.45 mag arcsec{}-2 in the Johnson-Cousins V-band, as the average of sky brightness equivalent to 2.8 × {10}-4{cd} {{{m}}}-2 over the entire island, is an indication that the island is, overall, still relatively dark. However, the amount of development taking place might reduce the number in the near future as the island is famous as a holiday destination.

  11. Spain 31-GHz observations of sky brightness temperatures

    NASA Technical Reports Server (NTRS)

    Gary, B. L.

    1988-01-01

    A water vapor radiometer was deployed at DSS 63 for 3 months of sky brightness temperature measurements at 31 GHz. An exceedance plot was derived from this data showing the fraction of time that 31 GHz 30 degree elevation angle brightness temperature exceeds specified values. The 5 percent exceedance statistics occurs at 75 K, compared with 70 K in Australia.

  12. Spatial Model of Sky Brightness Magnitude in Langkawi Island, Malaysia

    NASA Astrophysics Data System (ADS)

    Redzuan Tahar, Mohammad; Kamarudin, Farahana; Umar, Roslan; Khairul Amri Kamarudin, Mohd; Hazmin Sabri, Nor; Ahmad, Karzaman; Rahim, Sobri Abdul; Sharul Aikal Baharim, Mohd

    2017-03-01

    Sky brightness is an essential topic in the field of astronomy, especially for optical astronomical observations that need very clear and dark sky conditions. This study presents the spatial model of sky brightness magnitude in Langkawi Island, Malaysia. Two types of Sky Quality Meter (SQM) manufactured by Unihedron are used to measure the sky brightness on a moonless night (or when the Moon is below the horizon), when the sky is cloudless and the locations are at least 100 m from the nearest light source. The selected locations are marked by their GPS coordinates. The sky brightness data obtained in this study were interpolated and analyzed using a Geographic Information System (GIS), thus producing a spatial model of sky brightness that clearly shows the dark and bright sky areas in Langkawi Island. Surprisingly, our results show the existence of a few dark sites nearby areas of high human activity. The sky brightness of 21.45 mag arcsec{}-2 in the Johnson-Cousins V-band, as the average of sky brightness equivalent to 2.8 × {10}-4{cd} {{{m}}}-2 over the entire island, is an indication that the island is, overall, still relatively dark. However, the amount of development taking place might reduce the number in the near future as the island is famous as a holiday destination.

  13. Challenging Exceptionally Bright Children in Early Childhood Classrooms

    ERIC Educational Resources Information Center

    Gadzikowski, Ann

    2013-01-01

    Nearly every group of children includes at least one exceptionally bright child. From the especially creative child to the child who has already mastered learning outcomes to the "twice exceptional" child, exceptionally bright children have a wide range of talents and behaviors. This book will help you understand what it means to be…

  14. Challenging Exceptionally Bright Children in Early Childhood Classrooms

    ERIC Educational Resources Information Center

    Gadzikowski, Ann

    2013-01-01

    Nearly every group of children includes at least one exceptionally bright child. From the especially creative child to the child who has already mastered learning outcomes to the "twice exceptional" child, exceptionally bright children have a wide range of talents and behaviors. This book will help you understand what it means to be…

  15. The Two Intelligences of Bright, Average, and Retarded Children.

    ERIC Educational Resources Information Center

    DeVries, Rheta

    This study attempted to determine if performance on Piagetian tasks can be predicted from Stanford-Binet mental age or IQ. Subjects were 143 children of bright, average, and retarded abilities as measured by performance on the Stanford-Binet Intelligence Test. Bright and average children were chronologically aged five to seven years; retarded…

  16. Apparent Brightness and Topography Images of Vibidia Crater

    NASA Image and Video Library

    2012-03-09

    The left-hand image from NASA Dawn spacecraft shows the apparent brightness of asteroid Vesta surface. The right-hand image is based on this apparent brightness image, with a color-coded height representation of the topography overlain onto it.

  17. Broken Surface Brightness Profiles in Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Herrmann, Kimberly A.; Hunter, D. A.; Zhang, H. X.; LITTLE THINGS Team

    2011-01-01

    Recently it has been well shown that there are three different surface brightness profile types in spiral galaxies: (I) the minority, where the light falls off with a single exponential; (II) truncated, the majority, where the light falls off with one exponential to a break radius and then falls off more steeply; and (III) anti-truncated, where the light falls off with a more shallow exponential beyond the break radius. Additionally, Bakos, Trujillo, & Pohlen (2008) showed that each type has a characteristic color trend with respect to the break location. In dwarf disk galaxies, however, there is a fourth type which is perhaps a special Type II case: the light profile is flat on the inside and then falls off exponentially beyond the break radius. We will show the different color trends for these four profile types from a large photometric study of dwarf disk galaxies and explore the ramifications of the differences between spirals and dwarfs. We gratefully acknowledge funding for this research from the National Science Foundation (AST-0707563).

  18. Modular Zero Energy. BrightBuilt Home

    SciTech Connect

    Aldrich, Robb; Butterfield, Karla

    2016-03-01

    Kaplan Thompson Architects (KTA) has specialized in sustainable, energy-efficient buildings, and they have designed several custom, zero-energy homes in New England. These zero-energy projects have generally been high-end, custom homes with budgets that could accommodate advanced energy systems. In an attempt to make zero energy homes more affordable and accessible to a larger demographic, KTA explored modular construction as way to provide high-quality homes at lower costs. In the mid-2013, KTA formalized this concept when they launched BrightBuilt Home (BBH). The BBH mission is to offer a line of architect-designed, high-performance homes that are priced to offer substantial savings off the lifetime cost of a typical home and can be delivered in less time. For the past two years, CARB has worked with BBH and Keiser Homes (the primary modular manufacturer for BBH) to discuss challenges related to wall systems, HVAC, and quality control. In Spring of 2014, CARB and BBH began looking in detail on a home to be built in Lincolnville, ME by Black Bros. Builders. This report details the solution package specified for this modular plan and the challenges that arose during the project.

  19. Bright visible light emission from graphene

    NASA Astrophysics Data System (ADS)

    Kim, Young Duck; Kim, Hakseong; Cho, Yujin; Ryoo, Ji Hoon; Park, Cheol-Hwan; Kim, Pilkwang; Kim, Yong Seung; Lee, Sunwoo; Li, Yilei; Park, Seung-Nam; Shim Yoo, Yong; Yoon, Duhee; Dorgan, Vincent E.; Pop, Eric; Heinz, Tony F.; Hone, James; Chun, Seung-Hyun; Cheong, Hyeonsik; Lee, Sang Wook; Bae, Myung-Ho; Park, Yun Daniel

    2015-08-01

    Graphene and related two-dimensional materials are promising candidates for atomically thin, flexible and transparent optoelectronics. In particular, the strong light-matter interaction in graphene has allowed for the development of state-of-the-art photodetectors, optical modulators and plasmonic devices. In addition, electrically biased graphene on SiO2 substrates can be used as a low-efficiency emitter in the mid-infrared range. However, emission in the visible range has remained elusive. Here, we report the observation of bright visible light emission from electrically biased suspended graphene devices. In these devices, heat transport is greatly reduced. Hot electrons (˜2,800 K) therefore become spatially localized at the centre of the graphene layer, resulting in a 1,000-fold enhancement in thermal radiation efficiency. Moreover, strong optical interference between the suspended graphene and substrate can be used to tune the emission spectrum. We also demonstrate the scalability of this technique by realizing arrays of chemical-vapour-deposited graphene light emitters. These results pave the way towards the realization of commercially viable large-scale, atomically thin, flexible and transparent light emitters and displays with low operation voltage and graphene-based on-chip ultrafast optical communications.

  20. Intercomparisons of nine sky brightness detectors.

    PubMed

    den Outer, Peter; Lolkema, Dorien; Haaima, Marty; van der Hoff, Rene; Spoelstra, Henk; Schmidt, Wim

    2011-01-01

    Nine Sky Quality Meters (SQMs) have been intercompared during a night time measurement campaign held in the Netherlands in April 2011. Since then the nine SQMs have been distributed across The Netherlands and form the Dutch network for monitoring night sky brightness. The goal of the intercomparison was to infer mutual calibration factors and obtain insight into the variability of the SQMs under different meteorological situations. An ensemble average is built from the individual measurements and used as a reference to infer the mutual calibration factors. Data required additional synchronization prior to the calibration determination, because the effect of moving clouds combined with small misalignments emerges as time jitter in the measurements. Initial scatter of the individual instruments lies between ±14%. Individual night time sums range from -16% to +20%. Intercalibration reduces this to 0.5%, and -7% to +9%, respectively. During the campaign the smallest luminance measured was 0.657 ± 0.003 mcd/m(2) on 12 April, and the largest value was 5.94 ± 0.03 mcd/m(2) on 2 April. During both occurrences interfering circumstances like snow cover or moonlight were absent.

  1. The Bright Future of Gravitational Wave Astronomy

    NASA Astrophysics Data System (ADS)

    Gonzalez, Gabriela

    2008-04-01

    These are exciting times in the search for gravitational waves. Gravitational waves are expected from many different astrophysical sources: brief transients from violent events like supernova explosions and collisions of neutron stars and black holes, coalescence of compact binary systems, continuous waves from rotating systems, and stochastic signals from cosmological origin or unresolved transients. The LIGO gravitational wave detectors have achieved unprecedented sensitivity to gravitational waves, and other detectors around the world are expected to reach similar sensitivities. The LIGO Scientific Collaboration (LSC) has recently completed their most sensitive observation run to date with LIGO and GEO detectors, including several months of joint observations with the European VIRGO detector. The LIGO Laboratory and the LSC, as well as the Virgo Collaboration, are actively preparing for operating enhanced detectors in the very near future. The next decade will see the construction and commissioning of Advanced LIGO and VIRGO, and quite possibly the launch of the space-based LISA mission, starting for sure then, if not earlier, a new era for gravitational wave astronomy. Plans for a world-wide network of ground based detectors involving more detectors in Europe, Japan and Australia are becoming more concrete. The future of gravitational wave astronomy is bright indeed! In this talk, will briefly describe the present status of the ground and space based detector projects and discuss the science we may expect to do with the detectors (and detections!) we will have in the upcoming era of gravitational wave astronomy.

  2. NuSTAR Observations of Bright AGNs

    NASA Astrophysics Data System (ADS)

    Elvis, Martin; Ballantyne, D. R.; Blandford, R. D.; Boggs, S.; Boydstun, K.; Brenneman, L.; Cappi, M.; Christensen, F.; Craig, W.; Fabian, A.; Fuerst, F.; Guainazzi, M.; Hailey, C. J.; Harrison, F.; Madejski, G. M.; Marinucci, A.; Matt, G.; Nandra, K.; Reynolds, C. S.; Stern, D.; Walton, D.; Zhang, W.; NuSTAR Team

    2013-01-01

    The dramatically improved signal-to-noise provided by NuSTAR up to ~80 keV allows a qualitative change in our understanding of the X-ray emission of Active Galactic Nuclei (AGNs). Despite intensive investigation for over 30 years, during which the 0.1-10 keV spectra and variability of AGNs have been mapped out in detail, we do not know the origin of the X-ray source in AGNs. The "standard model" of supermassive black hole, accretion disk and relativistic jet does not predict an X-ray source in a straightforward way. It is usually assumed that the X-rays were UV photons from the accretion disk that have been Compton up-scattered in a "hot corona", but the temperature, optical depth and geometry of this corona are unknown - if it exists. NuSTAR enables the measurement of the high energy cut-off of the X-ray spectrum, and so the corona temperature, to be measured precisely for the first time, and tests the relativistic Fe-K line and Compton reflection models. If this model is correct then, with Suzaku and XMM-Newton, NuSTAR can measure black hole spins to high accuracy. We outline the NuSTAR GTO program on bright, unobscured, AGNs including simultaneous observations with Suzaku and XMM-Newton, and show early data.

  3. High output lamp with high brightness

    DOEpatents

    Kirkpatrick, Douglas A.; Bass, Gary K.; Copsey, Jesse F.; Garber, Jr., William E.; Kwong, Vincent H.; Levin, Izrail; MacLennan, Donald A.; Roy, Robert J.; Steiner, Paul E.; Tsai, Peter; Turner, Brian P.

    2002-01-01

    An ultra bright, low wattage inductively coupled electrodeless aperture lamp is powered by a solid state RF source in the range of several tens to several hundreds of watts at various frequencies in the range of 400 to 900 MHz. Numerous novel lamp circuits and components are disclosed including a wedding ring shaped coil having one axial and one radial lead, a high accuracy capacitor stack, a high thermal conductivity aperture cup and various other aperture bulb configurations, a coaxial capacitor arrangement, and an integrated coil and capacitor assembly. Numerous novel RF circuits are also disclosed including a high power oscillator circuit with reduced complexity resonant pole configuration, parallel RF power FET transistors with soft gate switching, a continuously variable frequency tuning circuit, a six port directional coupler, an impedance switching RF source, and an RF source with controlled frequency-load characteristics. Numerous novel RF control methods are disclosed including controlled adjustment of the operating frequency to find a resonant frequency and reduce reflected RF power, controlled switching of an impedance switched lamp system, active power control and active gate bias control.

  4. Dark Skies, Bright Kids Year 6

    NASA Astrophysics Data System (ADS)

    Liss, Sandra; Troup, Nicholas William; Johnson, Kelsey E.; Barcos-Munoz, Loreto D.; Beaton, Rachael; Bittle, Lauren; Borish, Henry J.; Burkhardt, Andrew; Corby, Joanna; Dean, Janice; Hancock, Danielle; King, Jennie; Prager, Brian; Romero, Charles; Sokal, Kimberly R.; Stierwalt, Sabrina; Wenger, Trey; Zucker, Catherine

    2015-01-01

    Now entering our sixth year of operation, Dark Skies, Bright Kids (DSBK) is an entirely volunteer-run outreach organization based out of the Department of Astronomy at the University of Virginia. Our core mission is to enhance elementary science education and literacy in central Virginia through fun, hands-on activities that introduce basic Astronomy concepts beyond Virginia's Standards of Learning. Our primary focus is hosting an 8-10 week after-school astronomy club at underserved elementary and middle schools. Each week, DSBK volunteers take the role of coaches to introduce astronomy-related concepts ranging from the Solar System to galaxies to astrobiology, and to lead students in interactive learning activities. Another hallmark of DSBK is hosting our Annual Central Virginia Star Party, a free event open to the community featuring star-gazing and planetarium shows.DSBK has amassed over 15,000 contact hours since 2009 and we continue to broaden our impact. One important step we have taken in the past year is to establish a graduate student led assessment program to identify and implement directed learning goals for DSBK outreach. The collection of student workbooks, observations, and volunteer surveys indicates broad scale success for the program both in terms of student learning and their perception of science. The data also reveal opportunities to improve our organizational and educational practices to maximize student achievement and overall volunteer satisfaction for DSBK's future clubs and outreach endeavors.

  5. MAGNETIC BRIGHT POINTS IN THE QUIET SUN

    SciTech Connect

    Sanchez Almeida, J.; Bonet, J. A.; Viticchie, B.

    2010-05-20

    We present a visual determination of the number of bright points (BPs) existing in the quiet Sun, which are structures though to trace intense kG magnetic concentrations. The measurement is based on a 0.''1 angular resolution G-band movie obtained with the Swedish Solar Telescope at the solar disk center. We find 0.97 BPs Mm{sup -2}, which is a factor 3 larger than any previous estimate. It corresponds to 1.2 BPs per solar granule. Depending on the details of the segmentation, the BPs cover between 0.9% and 2.2% of the solar surface. Assuming their field strength to be 1.5 kG, the detected BPs contribute to the solar magnetic flux with an unsigned flux density between 13 G and 33 G. If network and inter-network regions are counted separately, they contain 2.2 BPs Mm{sup -2} and 0.85 BPs Mm{sup -2}, respectively.

  6. Due process traditionalism.

    PubMed

    Sunstein, Cass R

    2008-06-01

    In important cases, the Supreme Court has limited the scope of "substantive due process" by reference to tradition, but it has yet to explain why it has done so. Due process traditionalism might be defended in several distinctive ways. The most ambitious defense draws on a set of ideas associated with Edmund Burke and Friedrich Hayek, who suggested that traditions have special credentials by virtue of their acceptance by many minds. But this defense runs into three problems. Those who have participated in a tradition may not have accepted any relevant proposition; they might suffer from a systematic bias; and they might have joined a cascade. An alternative defense sees due process traditionalism as a second-best substitute for two preferable alternatives: a purely procedural approach to the Due Process Clause, and an approach that gives legislatures the benefit of every reasonable doubt. But it is not clear that in these domains, the first-best approaches are especially attractive; and even if they are, the second-best may be an unacceptably crude substitute. The most plausible defense of due process traditionalism operates on rule-consequentialist grounds, with the suggestion that even if traditions are not great, they are often good, and judges do best if they defer to traditions rather than attempting to specify the content of "liberty" on their own. But the rule-consequentialist defense depends on controversial and probably false assumptions about the likely goodness of traditions and the institutional incapacities of judges.

  7. Modeling the formation of bright slope deposits associated with gullies in Hale Crater, Mars: Implications for recent liquid water

    NASA Astrophysics Data System (ADS)

    Kolb, Kelly Jean; Pelletier, Jon D.; McEwen, Alfred S.

    2010-01-01

    Our study investigates possible formation mechanisms of the very recent bright gully deposits (BGDs) observed on Mars in order to assess if liquid water was required. We use two models in our assessment: a one-dimensional (1D) kinematic model to model dry granular flows and a two-dimensional (2D) fluid-dynamic model, FLO-2D ( O'Brien et al., 1993, FLO Engineering), to model water-rich and wet sediment-rich flows. Our modeling utilizes a high-resolution topographic model generated from a pair of images acquired by the High Resolution Imaging Science Experiment (HiRISE) aboard the Mars Reconnaissance Orbiter. For the 1D kinematic modeling of dry granular flows, we examine a range of particle sizes, flow thicknesses, initial velocities, flow densities, and upslope initiation points to examine how these parameters affect the flow run-out distances of the center of mass of a flow. Our 1D modeling results show that multiple combinations of realistic parameters could produce dry granular flows that travel to within the observed deposits' boundaries. We run the 2D fluid-dynamic model, FLO-2D, to model both water-rich and wet sediment-rich flows. We vary the inflow volume, inflow location, discharge rate, water-loss rate (water-rich models only), and simulation time and examine the resulting maximum flow depths and velocities. Our 2D modeling results suggest that both wet sediment-rich and water-rich flows could produce the observed bright deposits. Our modeling shows that the BGDs are not definitive evidence of recent liquid water on the surface of Mars.

  8. The CBM RICH project

    NASA Astrophysics Data System (ADS)

    Adamczewski-Musch, J.; Akishin, P.; Becker, K.-H.; Belogurov, S.; Bendarouach, J.; Boldyreva, N.; Chernogorov, A.; Deveaux, C.; Dobyrn, V.; Dürr, M.; Eschke, J.; Förtsch, J.; Heep, J.; Höhne, C.; Kampert, K.-H.; Kochenda, L.; Kopfer, J.; Kravtsov, P.; Kres, I.; Lebedev, S.; Lebedeva, E.; Leonova, E.; Linev, S.; Mahmoud, T.; Michel, J.; Miftakhov, N.; Niebur, W.; Ovcharenko, E.; Patel, V.; Pauly, C.; Pfeifer, D.; Querchfeld, S.; Rautenberg, J.; Reinecke, S.; Riabov, Y.; Roshchin, E.; Samsonov, V.; Tarasenkova, O.; Traxler, M.; Ugur, C.; Vznuzdaev, E.; Vznuzdaev, M.

    2017-02-01

    The CBM RICH detector is an integral component of the future CBM experiment at FAIR, providing efficient electron identification and pion suppression necessary for the measurement of rare dileptonic probes in heavy ion collisions. The RICH design is based on CO2 gas as radiator, a segmented spherical glass focussing mirror with Al+MgF2 reflective coating, and Multianode Photomultipliers for efficient Cherenkov photon detection. Hamamatsu H12700 MAPMTs have recently been selected as photon sensors, following an extensive sensor evaluation, including irradiation tests to ensure sufficient radiation hardness of the MAPMTs. A brief overview of the detector design and concept is given, results on the radiation hardness of the photon sensors are shown, and the development of a FPGA-TDC based readout chain is discussed.

  9. Silica-Rich Soil Found by Spirit

    NASA Technical Reports Server (NTRS)

    2007-01-01

    NASA's Mars Exploration Rover Spirit has found a patch of bright-toned soil so rich in silica that scientists propose water must have been involved in concentrating it.

    The silica-rich patch, informally named 'Gertrude Weise' after a player in the All-American Girls Professional Baseball League, was exposed when Spirit drove over it during the 1,150th Martian day, or sol, of Spirit's Mars surface mission (March 29, 2007). One of Spirit's six wheels no longer rotates, so it leaves a deep track as it drags through soil. Most patches of disturbed, bright soil that Spirit had investigated previously are rich in sulfur, but this one has very little sulfur and is about 90 percent silica.

    This image is a approximately true-color composite of three images taken through different filters by Spirit's panoramic camera on Sol 1,187 (May 6). The track of disturbed soil is roughly 20 centimeters (8 inches) wide.

    Spirit's miniature thermal emission spectrometer, which can assess a target's mineral composition from a distance, examined the Gertrude Weise patch on Sol 1,172 (April 20). The indications it found for silica in the overturned soil prompted a decision to drive Spirit close enough to touch the soil with the alpha particle X-ray spectrometer, a chemical analyzer at the end of Spirit's robotic arm. The alpha particle X-ray spectrometer collected data about this target on sols 1,189 and 1,190 (May 8 and May 9) and produced the finding of approximately 90 percent silica.

    Silica is silicon dioxide. On Earth, it commonly occurs as the crystalline mineral quartz and is the main ingredient in window glass. The Martian silica at Gertrude Weise is non-crystalline, with no detectable quartz.

    In most cases, water is required to produce such a concentrated deposit of silica, according to members of the rover science team. One possible origin for the silica could have been interaction of soil with acidic steam produced by volcanic activity. Another could

  10. Silica-Rich Soil Found by Spirit

    NASA Technical Reports Server (NTRS)

    2007-01-01

    NASA's Mars Exploration Rover Spirit has found a patch of bright-toned soil so rich in silica that scientists propose water must have been involved in concentrating it.

    The silica-rich patch, informally named 'Gertrude Weise' after a player in the All-American Girls Professional Baseball League, was exposed when Spirit drove over it during the 1,150th Martian day, or sol, of Spirit's Mars surface mission (March 29, 2007). One of Spirit's six wheels no longer rotates, so it leaves a deep track as it drags through soil. Most patches of disturbed, bright soil that Spirit had investigated previously are rich in sulfur, but this one has very little sulfur and is about 90 percent silica.

    This image is a approximately true-color composite of three images taken through different filters by Spirit's panoramic camera on Sol 1,187 (May 6). The track of disturbed soil is roughly 20 centimeters (8 inches) wide.

    Spirit's miniature thermal emission spectrometer, which can assess a target's mineral composition from a distance, examined the Gertrude Weise patch on Sol 1,172 (April 20). The indications it found for silica in the overturned soil prompted a decision to drive Spirit close enough to touch the soil with the alpha particle X-ray spectrometer, a chemical analyzer at the end of Spirit's robotic arm. The alpha particle X-ray spectrometer collected data about this target on sols 1,189 and 1,190 (May 8 and May 9) and produced the finding of approximately 90 percent silica.

    Silica is silicon dioxide. On Earth, it commonly occurs as the crystalline mineral quartz and is the main ingredient in window glass. The Martian silica at Gertrude Weise is non-crystalline, with no detectable quartz.

    In most cases, water is required to produce such a concentrated deposit of silica, according to members of the rover science team. One possible origin for the silica could have been interaction of soil with acidic steam produced by volcanic activity. Another could

  11. Global Snow Mass Measurements and the Effect of Stratigraphic Detail on Inversion of Microwave Brightness Temperatures

    NASA Astrophysics Data System (ADS)

    Richardson, Mark; Davenport, Ian; Gurney, Robert

    2014-05-01

    Snow provides large seasonal storage of freshwater, and information about the distribution of snow mass as snow water equivalent (SWE) is important for hydrological planning and detecting climate change impacts. Large regional disagreements remain between estimates from reanalyses, remote sensing and modelling. Assimilating passive microwave information improves SWE estimates in many regions, but the assimilation must account for how microwave scattering depends on snow stratigraphy. Physical snow models can estimate snow stratigraphy, but users must consider the computational expense of model complexity versus acceptable errors. Using data from the National Aeronautics and Space Administration Cold Land Processes Experiment and the Helsinki University of Technology microwave emission model of layered snowpacks, it is shown that simulations of the brightness temperature difference between 19 and 37 GHz vertically polarised microwaves are consistent with advanced microwave scanning radiometer-earth observing system and special sensor microwave imager retrievals once known stratigraphic information is used. Simulated brightness temperature differences for an individual snow profile depend on the provided stratigraphic detail. Relative to a profile defined at the 10-cm resolution of density and temperature measurements, the error introduced by simplification to a single layer of average properties increases approximately linearly with snow mass. If this brightness temperature error is converted into SWE using a traditional retrieval method, then it is equivalent to ±13 mm SWE (7 % of total) at a depth of 100 cm. This error is reduced to ±5.6 mm SWE (3 % of total) for a two-layer model.

  12. Tradition and Innovation.

    ERIC Educational Resources Information Center

    Katter, Eldon, Ed.

    1995-01-01

    "The articles in this issue were selected because, in one way or another, they all touched on the notion of tradition and innovation." Storytelling and tribal dances are examples of past, traditional methods of passing cultural knowledge from elders to youth. Contemporary youth have replaced tradtional rites of passage with their own…

  13. Family Customs and Traditions.

    ERIC Educational Resources Information Center

    MacGregor, Cynthia

    Recognizing the importance of maintaining open communication with immediate and extended family members, this book provides a compilation of ideas for family traditions and customs that are grounded in compassion and human kindness. The traditions were gathered from families in the United States and Canada who responded to advertisements in…

  14. Family Customs and Traditions.

    ERIC Educational Resources Information Center

    MacGregor, Cynthia

    Recognizing the importance of maintaining open communication with immediate and extended family members, this book provides a compilation of ideas for family traditions and customs that are grounded in compassion and human kindness. The traditions were gathered from families in the United States and Canada who responded to advertisements in…

  15. Rethinking the "Western Tradition"

    ERIC Educational Resources Information Center

    Enslin, Penny; Horsthemke, Kai

    2015-01-01

    In recent years, the "Western tradition" has increasingly come under attack in anti-colonialist and postmodernist discourses. It is not difficult to sympathise with the concerns that underlie advocacy of historically marginalised traditions, and the West undoubtedly has a lot to answer for. Nonetheless, while arguing a qualified yes to…

  16. Traditional Native Poetry.

    ERIC Educational Resources Information Center

    Grant, Agnes

    1985-01-01

    While Native myths and legends were educational tools to transmit tribal beliefs and history, traditional American Indian poetry served a ritualistic function in everyday life. Few traditional Native songs, which all poems were, survive; only Mayan and Aztec poems were written, and most of these were burned by a Spanish bishop. In addition, many…

  17. Rethinking the "Western Tradition"

    ERIC Educational Resources Information Center

    Enslin, Penny; Horsthemke, Kai

    2015-01-01

    In recent years, the "Western tradition" has increasingly come under attack in anti-colonialist and postmodernist discourses. It is not difficult to sympathise with the concerns that underlie advocacy of historically marginalised traditions, and the West undoubtedly has a lot to answer for. Nonetheless, while arguing a qualified yes to…

  18. Traditional Native Poetry.

    ERIC Educational Resources Information Center

    Grant, Agnes

    1985-01-01

    While Native myths and legends were educational tools to transmit tribal beliefs and history, traditional American Indian poetry served a ritualistic function in everyday life. Few traditional Native songs, which all poems were, survive; only Mayan and Aztec poems were written, and most of these were burned by a Spanish bishop. In addition, many…

  19. Dark Skies, Bright Kids! Year 3

    NASA Astrophysics Data System (ADS)

    Whelan, David G.; Johnson, K. E.; Barcos-Munoz, L. D.; Beaton, R. L.; Borish, J.; Corby, J. F.; Dorsey, G.; Gugliucci, N. E.; Prager, B. J.; Ries, P. A.; Romero, C. E.; Sokal, K. R.; Tang, X.; Walker, L. M.; Yang, A. J.; Zasowski, G.

    2012-01-01

    Dark Skies, Bright Kids! (DSBK) is a program that brings astronomy education to elementary schools throughout central Virginia. In a relaxed, out-of-classroom atmosphere, we are able to foster the innate curiosity that young students have about science and the world around them. We target schools that are under-served due to their rural locale or special needs students, demonstrating that science is a fun and creative process to a segment of the population that might not otherwise be exposed to astronomy. Families are included in the learning experience during semi-annual `star parties'. Since last January, we have expanded the breadth and depth of our educational capabilities. We have developed new programs for use in our digital planetarium. We held the first Central Virginia Star Party, providing an atmosphere where local children from multiple schools were able to share their love for astronomy. Local government and University officials were also invited so that they could experience our focused science outreach. Most recently, we have become part of Ivy Creek School's Club Day activities, bringing our program to a new segment of the elementary school system in Albemarle County: those that have `low-incidence' disabilities, requiring special attention. We continue to develop a curriculum for after-school programs that functions as either a series of one-time activities or several months of focused outreach at one school. Many of these activities are provided on our website, http://www.astro.virginia.edu/dsbk/, for the wider astronomical community, including the new planetarium work. We have extended our book project to include two bilingual astronomy books called `Snapshots of the Universe,' one in Spanish and English, the other in French and English. These books introduce young people to some of the many wonders of the Universe through art and captions developed by DSBK volunteers.

  20. Dark Skies, Bright Kids! Year 4

    NASA Astrophysics Data System (ADS)

    Sokal, Kimberly R.; Johnson, K. E.; Barcos-Munoz, L. D.; Beaton, R.; Borish, J.; Crawford, S. B.; Corby, J.; Damke, G.; Dean, J.; Dorsey, G.; Jackson, L.; Liss, S.; Oza, A.; Peacock, S.; Prager, B.; Romero, C.; Sivakoff, G. R.; Walker, L.; Whelan, D. G.; Zucker, C.

    2013-01-01

    Aiming to engage young children's natural excitement and curiosity, the outreach group Dark Skies, Bright Kids (DSBK) brings a hands-on approach to astronomy to elementary schools in Virginia. We hope to enhance children's view and understanding of science while exploring the Universe using fun activities. DSBK focuses on rural and underserved schools in Albemarle County and offers a semester-long astronomy club for third through fifth grade students. We believe regular interactions foster personal relationships between students and volunteers that encourage a life-long interest in science. In our fourth year of hosting clubs, we returned to Ivy Creek Elementary School, where we saw wonderful responses from a special group of students with `low-incidence' disabilities. DSBK has grown to realize a broader reach beyond local astronomy clubs; we hope to ignite a spark of interest in astronomy and science more widely- in more children, their families, and their teachers. We also hosted the Second Annual Central Virginia Star Party with an open invitation to the community to encourage families to enjoy astronomy together. Throughout the year, DSBK now holds 'one-off' programs (akin to astronomy field days) for elementary schools and children's groups throughout Virginia. Furthermore, we are in the final stages of a project to create two bilingual astronomy books called "Snapshots of the Universe", in Spanish and French with English translations. This art book will be made available online and we are working to get a copy in every elementary school in the state. DSBK has begun to reach out to elementary school teachers in order to provide them with useful and engaging classroom material. We have adapted our volunteer-created activities into useful and ready-to-use lessons, available online. After improvements based on research through interactions and feedback from teachers, we have explicitly identified the learning goals in terms of Virginia's Standards of Learning

  1. Dark Skies, Bright Kids! Year 5

    NASA Astrophysics Data System (ADS)

    Prager, Brian; Johnson, K. E.; Barcos-Munoz, L. D.; Beaton, R.; Bittle, L.; Borish, H.; Burkhardt, A.; Corby, J.; Damke, G.; Dean, J.; Dorsey, G.; Graninger, D.; Lauck, T.; Liss, S.; Oza, A.; Peacock, S.; Romero, C.; Sokal, K. R.; Stierwalt, S.; Walker, L.; Wenger, T.; Zucker, C.

    2014-01-01

    Our public outreach group Dark Skies, Bright Kids! (DSBK) fosters science literacy in Virginia by bringing a hands-on approach to astronomy that engages children's natural excitement and curiosity. We are an entirely volunteer-run group based out of the Department of Astronomy at the University of Virginia and we enthusiastically utilize astronomy as a 'gateway science.' We create long-term relationships with students during an 8 to 10 week long, after-school astronomy club at under served elementary schools in neighboring counties, and we visited 3 different schools in 2013. Additionally, we organize and participate in science events throughout the community. The fifth year of DSBK was marked by surpassing 10,000 contact hours in Spring 2013 Semester and by ringing in the fall semester with our biggest, most successful star party to date. We hosted the Third Annual Central Virginia Star Party, free and open to the community to encourage families to enjoy astronomy together. Nearly four hundred people of all ages attended, double the number from previous years. Joining with local astronomical societies, we offered an enlightening and exciting night with resources rarely accessible to the public, such as an IR camera and a portable planetarium. With numerous telescopes pointed at the sky, and a beautifully clear night with views of the Milky Way, the International Space Station, and numerous meteors, the star party was a fantastic opportunity to introduce many of our guests to the natural wonders of our night sky and enjoy some of the darkest skies on the eastern seaboard.

  2. CO observations towards bright-rimmed clouds

    NASA Astrophysics Data System (ADS)

    Morgan, L. K.; Urquhart, J. S.; Thompson, M. A.

    2009-12-01

    Bright-rimmed clouds (BRCs) appear to be sites of triggered star formation induced through the propagation of shocks initiated by the expansion of nearby HII regions. Our main aim is to establish support for observations of star-forming activity within a sample of BRCs. A secondary aim is to establish a plausible link between such star formation and observed external influences. We have conducted CO (J = 2-1) observations using the James Clerk Maxwell Telescope to probe the environments of a sample of star-forming BRCs associated with embedded protostellar cores. Local thermodynamic equilibrium analysis allows the determination of the physical properties of these protostars and investigation of the structure and kinematic motions within the molecular gas. Using a combination of archival radio and mid-infrared data, and submillimeter observations, we have refined the Sugitani, Fukui and Ogura (SFO) catalogue, excluding 18 BRCs that do not show any evidence of photoionization induced collapse. Of the remaining 26 clouds that are being photoionized, we find 20 that are associated with embedded protostars. These 20 clouds are excellent candidates with which to further investigate the radiatively driven implosion mode of triggered star formation. Comparing the physical parameters of the triggered and untriggered samples, we find that the surface temperatures of the potentially triggered clouds are significantly higher (by ~10 K) than those in which triggering is considered unlikely. The higher surface temperatures found towards the sample of potentially triggered clouds are consistent with the hypothesis that these clouds are being externally heated through their exposure to the HII region.

  3. MAGNETIC FLUX SUPPLEMENT TO CORONAL BRIGHT POINTS

    SciTech Connect

    Mou, Chaozhou; Huang, Zhenghua; Xia, Lidong; Li, Bo; Fu, Hui; Jiao, Fangran; Hou, Zhenyong; Madjarska, Maria S.

    2016-02-10

    Coronal bright points (BPs) are associated with magnetic bipolar features (MBFs) and magnetic cancellation. Here we investigate how BP-associated MBFs form and how the consequent magnetic cancellation occurs. We analyze longitudinal magnetograms from the Helioseismic and Magnetic Imager to investigate the photospheric magnetic flux evolution of 70 BPs. From images taken in the 193 Å passband of the Atmospheric Imaging Assembly (AIA) we dermine that the BPs’ lifetimes vary from 2.7 to 58.8 hr. The formation of the BP MBFs is found to involve three processes, namely, emergence, convergence, and local coalescence of the magnetic fluxes. The formation of an MBF can involve more than one of these processes. Out of the 70 cases, flux emergence is the main process of an MBF buildup of 52 BPs, mainly convergence is seen in 28, and 14 cases are associated with local coalescence. For MBFs formed by bipolar emergence, the time difference between the flux emergence and the BP appearance in the AIA 193 Å passband varies from 0.1 to 3.2 hr with an average of 1.3 hr. While magnetic cancellation is found in all 70 BPs, it can occur in three different ways: (I) between an MBF and small weak magnetic features (in 33 BPs); (II) within an MBF with the two polarities moving toward each other from a large distance (34 BPs); (III) within an MBF whose two main polarities emerge in the same place simultaneously (3 BPs). While an MBF builds up the skeleton of a BP, we find that the magnetic activities responsible for the BP heating may involve small weak fields.

  4. Chromospheric evaporation in sympathetic coronal bright points

    NASA Astrophysics Data System (ADS)

    Zhang, Q. M.; Ji, H. S.

    2013-09-01

    Context. Chromospheric evaporation is a key process in solar flares that has been extensively investigated using spectroscopic observations. However, direct soft X-ray (SXR) imaging of the process is rare, especially in remote brightenings associated with the primary flares that have recently attracted a great deal of attention. Aims: We intend to find the evidence for chromospheric evaporation and figure out the cause of the process in sympathetic coronal bright points (CBPs), i.e., remote brightenings induced by the primary CBP. Methods: We utilised the high-cadence and high-resolution SXR observations of CBPs from the X-ray Telescope (XRT) aboard the Hinode spacecraft on 2009 August 23. Results: We discovered a thermal conduction front propagating from the primary CBP (hereafter BP1) to the first of the sympathetic CBPs (hereafter BP2) that is 60″ away from BP1. The apparent velocity of the thermal conduction is ~138 km s-1. Afterwards, hot plasma flowed upwards into the loop connecting BP1 and BP2 at a speed of ~76 km s-1, a clear signature of chromospheric evaporation. Similar upflow was also observed in the loop connecting BP1 and the other sympathetic CBP (hereafter BP3) that is 80″ away from BP1, though less significant than BP2. The apparent velocity of the upflow is ~47 km s-1. The thermal conduction front propagating from BP1 to BP3 was not well identified except for the jet-like motion also originating from BP1. Conclusions: We propose that the gentle chromospheric evaporation in the sympathetic CBPs were caused by thermal conduction originating from the primary CBP.

  5. [Bright light therapy in seasonal bipolar depressions].

    PubMed

    Geoffroy, P A; Fovet, T; Micoulaud-Franchi, J-A; Boudebesse, C; Thomas, P; Etain, B; Amad, A

    2015-12-01

    Bipolar disorders (BD) are frequent mood disorders associated with a poor prognosis mainly due to a high relapse rate. Depressive relapses may follow a seasonal cyclicality, and bright-light therapy (BLT) has been established as the treatment of choice for seasonal affective disorder (SAD). The use of BLT for seasonal unipolar depression is well known, but the scientific literature is much poorer on the management of seasonal depressive episodes in BD. In addition, some specificities related to BD must be taken into account. We conducted a comprehensive review using Medline and Google Scholar databases up to August 2014 using the following keywords combination: "bipolar disorder" and "light therapy" or "phototherapy". Papers were included in the review if (a) they were published in an English or French-language peer-reviewed journal; (b) the study enrolled patients with BD and SAD; and (c) the diagnosis was made according to the DSM or ICD criteria. BLT was considered among the first-line treatments for SAD with a size effect similar to antidepressants. Most of the studies did not distinguish between patients with unipolar and bipolar disorders. However, it has been demonstrated that the most significant risk of BLT in patients with BD is the mood shift. Thus, the most important therapeutic adaptation corresponds to the use of an effective mood stabilizer, as with any antidepressant. Another therapeutic adaptation in first intention is that the times of exposure to light should be shifted from morning to midday. This review also includes therapeutic guidelines regarding the management of BLT in seasonal bipolar depressive episodes. There are very few specific data on seasonal bipolar depressive episodes. This literature review has highlighted that BLT should be handled as a regular antidepressant treatment in patients suffering from seasonal bipolar depressive episodes. Copyright © 2015 L’Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

  6. Magnetic Flux Supplement to Coronal Bright Points

    NASA Astrophysics Data System (ADS)

    Mou, Chaozhou; Huang, Zhenghua; Xia, Lidong; Madjarska, Maria S.; Li, Bo; Fu, Hui; Jiao, Fangran; Hou, Zhenyong

    2016-02-01

    Coronal bright points (BPs) are associated with magnetic bipolar features (MBFs) and magnetic cancellation. Here we investigate how BP-associated MBFs form and how the consequent magnetic cancellation occurs. We analyze longitudinal magnetograms from the Helioseismic and Magnetic Imager to investigate the photospheric magnetic flux evolution of 70 BPs. From images taken in the 193 Å passband of the Atmospheric Imaging Assembly (AIA) we dermine that the BPs’ lifetimes vary from 2.7 to 58.8 hr. The formation of the BP MBFs is found to involve three processes, namely, emergence, convergence, and local coalescence of the magnetic fluxes. The formation of an MBF can involve more than one of these processes. Out of the 70 cases, flux emergence is the main process of an MBF buildup of 52 BPs, mainly convergence is seen in 28, and 14 cases are associated with local coalescence. For MBFs formed by bipolar emergence, the time difference between the flux emergence and the BP appearance in the AIA 193 Å passband varies from 0.1 to 3.2 hr with an average of 1.3 hr. While magnetic cancellation is found in all 70 BPs, it can occur in three different ways: (I) between an MBF and small weak magnetic features (in 33 BPs); (II) within an MBF with the two polarities moving toward each other from a large distance (34 BPs); (III) within an MBF whose two main polarities emerge in the same place simultaneously (3 BPs). While an MBF builds up the skeleton of a BP, we find that the magnetic activities responsible for the BP heating may involve small weak fields.

  7. All Bright Cold Classical KBOs are Binary

    NASA Astrophysics Data System (ADS)

    Noll, Keith S.; Parker, Alex H.; Grundy, William M.

    2014-11-01

    When sorted by absolute magnitude as seen in ground based observations, an extremely high fraction of the brightest Cold Classical (CC) Kuiper Belt objects (KBO) are, in fact resolved as binaries when observed at higher angular resolution. Of the 22 CCs brighter than H=6.1 observed by HST, 16 have been found to be binary yielding a binary fraction of 73±10%. When low inclination interlopers from the hot population and close binaries are considered, this very high fraction is consistent with 100% of bright CCs being binary. At fainter absolute magnitudes, this fraction drops to ~20%. Such a situation is a natural outcome of a broken size distribution with a steep drop-off in the number of CCs with individual component diameters larger than 150 km (for an assumed albedo of 0.15). A sharp cutoff in the size distribution for CCs is consistent with formation models that suggest that most planetesimals form at a preferred modal size of order 100 km.The very high fraction of binaries among the largest CCs also serves to limit the separation distribution of KBO binaries. At most, 27% of the brightest CCs are possible unresolved binaries. The apparent power law distribution of binary separation must cut off near the current observational limits of HST ( 1800 km at 43 AU). It is worth noting, however, that this observation does not constrain how many components of resolved binaries may themselves be unresolved multiples like 47171 1999 TC36. Finally, it is important to point out that, when sorted by the size of the primary rather than absolute magnitude of the unresolved pair, the fraction of binaries is relatively constant with size (Nesvorny et al. 2011, AJ 141, 159) eliminating observational bias as cause of the pile up of binaries among the brightest Cold Classical Kuiper Belt objects.The very high fraction of binaries among the brightest CCs appears to be an effect of the underlying CC size distribution.

  8. Impact of snow on surface brightness

    NASA Astrophysics Data System (ADS)

    Kukla, George J.; Brown, Jeffrey A.

    The snow-covered land surface has different albedo than the snow-free surface, depending primarily on the type and density of the vegetation, the relief, and the continuity and age of the snow blanket. This is clearly demonstrated by the winter mosaic of east central Asia shown on the front cover. It is a section of a larger composite assembled from cloud-free satellite images to portray the land surface under continuous snow cover. The mosaic is a valuable tool for distinguishing (from remote positions) snow from clouds and for charting snow cover where illumination is poor. It also can be used to determine relative sensitivity of surface albedo to the occurrence of snow.Segments with a minimum of clouds along the orbital subtrack were selected from the transparencies of the Defense Meteorological Satellite Program (DMSP). Satellite sensors record in the spectral band 0.4-1.2 µm. The satellite is in polar orbit at a mean altitude of 830 km (450 nm) and crosses the equator at approximately local noon. The spatial resolution along the orbital subtrack is about 0.6 km [Dickinson et al., 1974]. The mosaic is assembled from imagery taken between mid-January and mid-February of 1979. The original hard-copy transparencies (on loan from the DMSP library) were reproduced as contact negatives to preserve detail.The snow cover marks the land surface with a characteristic signature that depends on the distribution, density, and type of vegetation; relief; presence of water bodies; distribution and type of land use, etc. This signature can be readily utilized, among others, to distinguish snow-covered land from clouds and from snow-free land [Barnes et al., 1974; Lillesand et al., 1982]. We have compared the brightness fields in the imagery with the vegetation density and land-use patterns charted in the World Forestry Atlas [Wiebecke, 1971].

  9. Dark Skies, Bright Kids: Year 2

    NASA Astrophysics Data System (ADS)

    Carlberg, Joleen K.; Johnson, K.; Lynch, R.; Walker, L.; Beaton, R.; Corby, J.; de Messieres, G.; Drosback, M.; Gugliucci, N.; Jackson, L.; Kingery, A.; Layman, S.; Murphy, E.; Richardson, W.; Ries, P.; Romero, C.; Sivakoff, G.; Sokal, K.; Trammell, G.; Whelan, D.; Yang, A.; Zasowski, G.

    2011-01-01

    The Dark Skies, Bright Kids (DSBK) outreach program brings astronomy education into local elementary schools in central Virginia's Southern Albemarle County through an after-school club. Taking advantage of the unusually dark night skies in the rural countryside, DSBK targets economically disadvantaged schools that tend to be underserved due to their rural locale. The goals of DSBK are to foster children's natural curiosity, demonstrate that science is a fun and creative process, challenge students' conceptions of what a scientist is and does, and teach some basic astronomy. Furthermore, DSBK works to assimilate families into students' education by holding family observing nights at the school. Now in its third semester, DSBK has successfully run programs at two schools with very diverse student populations. Working with these students has helped us to revise our activities and to create new ones. A by-product of our work has been the development of lesson plans, complete with learning goals and detailed instructions, that we make publically available on our website. This year we are expanding our repertoire with our new planetarium, which allows us to visualize topics in novel ways and supplements family observing on cloudy nights. The DSBK volunteers have also created a bilingual astronomy artbook --- designed, written, and illustrated by UVa students --- that we will publish and distribute to elementary schools in Virginia. Our book debuted at the last AAS winter meeting, and since then it has been extensively revised and updated with input from many individuals, including parents, professional educators, and a children's book author. Because the club is currently limited to serving a few elementary schools, this book will be part of our efforts to broaden our impact by bringing astronomy to schools we cannot go to ourselves and reaching out to Spanish-speaking communities at the same time.

  10. Traditional food systems research with Canadian Indigenous Peoples.

    PubMed

    Kuhnlein, H V; Receveur, O; Chan, H M

    2001-04-01

    Traditional food systems research with Canadian Indigenous Peoples has revealed many aspects of benefits and risks of the use of this food. Traditions based in hunting, fishing and gathering contain a great variety of species of wildlife plants and animals that provide rich cultural and nutritional benefits. Dietary change for Indigenous Peoples in Canada has resulted in the use of traditional food to provide usually less than 30% of total dietary energy; however this portion of the total diet contributes significantly more of essential nutrients. It also results in exposure to organochlorine and heavy metal contaminants that exceed the tolerable intake levels for some areas. A successful research and education intervention program with one British Columbia community demonstrated that increasing traditional food use can improve health status for vitamin A, iron and folic acid. It is concluded that traditional food systems are rich with potential for research and public health education intervention programs for Indigenous Peoples.

  11. The lowest spatial frequency channel determines brightness perception.

    PubMed

    Perna, A; Morrone, M C

    2007-05-01

    This study investigates the role played by individual spatial scales in determining the apparent brightness of greyscale patterns. We measured the perceived difference in brightness across an edge in the presence of notch filtering and high-pass filtering for two stimulus configurations, one that elicits the perception of transparency and one that appears opaque. For both stimulus configurations, the apparent brightness of the surfaces delimited by the border decreased monotonically with progressive (ideal) high-pass filtering, with a critical cut-off at 1 c/deg. Using two octave ideal notch filtering, the maximum detrimental effect on apparent brightness was observed at about 1c/deg. Critical frequencies for apparent brightness did not vary with contrast, viewing distance, or surface size, suggesting that apparent brightness is determined by the channel tuned at 1 c/deg. Modelling the data with the local energy model [Morrone, M. C., & Burr, D. C. (1988). Feature detection in human vision: a phase dependent energy model. Proceedings of the Royal Society (London), B235, 221-245] at 1c/deg confirmed the suggestion that this channel mediates apparent brightness for both opaque and transparent borders, with no need for pooling or integration across spatial channels.

  12. Perceived brightness of incandescent and LED aviation signal lights.

    PubMed

    Bullough, John D; Yuan, Zongjie; Rea, Mark S

    2007-09-01

    Aviation signal lights using light emitting diodes (LEDs) are commonly perceived as brighter than those using incandescent sources, even at the same measured intensity. In general, saturated colors, like those produced by LEDs, appear brighter than less saturated lights, like those produced by incandescent sources. We describe a series of experiments quantifying the brightness of simulated blue, white, and green LED signal lights relative to incandescent signal lights of the same hue. Simulated signal lights and arrays were compared against dark and against dimly lighted backgrounds, and through simulated fog. The results confirm that LED signal lights are brighter than incandescent signals at matched luminous intensities. Brightness relationships were unaffected by background light level, and by the number of signals viewed, but the simulated fog reduced the brightness difference between the incandescent and LED signal lights. The present results could not be accurately predicted by several previously published models of brightness appearance, probably because of differences in experimental conditions. We present a new model that can be used to predict signal light brightness for blue, white, and green signal colors. Except for very short-wavelength blue signal lights, the model was able to accurately predict the present brightness data as well as those from previously published independent experiments. This validation lends confidence to the generality of the model for predicting blue, white, and green signal light brightness, but different colors (e.g., yellow or red) remain to be tested and modeled using this approach.

  13. Bright Building Blocks for Chemical Biology

    PubMed Central

    2014-01-01

    Small-molecule fluorophores manifest the ability of chemistry to solve problems in biology. As we noted in a previous review (Lavis, L. D.; Raines, R. T. ACS Chem. Biol.2008, 3, 142–155), the extant collection of fluorescent probes is built on a modest set of “core” scaffolds that evolved during a century of academic and industrial research. Here, we survey traditional and modern synthetic routes to small-molecule fluorophores and highlight recent biological insights attained with customized fluorescent probes. Our intent is to inspire the design and creation of new high-precision tools that empower chemical biologists. PMID:24579725

  14. Local health traditions.

    PubMed

    Shankar, D

    1988-03-01

    A very systematic study made in Karjat, Maharasht (a tribal area in India) has found that in comparison with the official health care and primary health centers, the traditional health practices are far more comprehensive. However, although the local traditions are comprehensive in their 'scope', they nevertheless reveal several weaknesses when subjected to critical evaluation by the science of Ayurveda. For example, whereas some remedies are found to be sound, there are others that are incomplete, and some appear to be totally distorted. Similarly, the diagnostic abilities of local practitioners, while sound in some cases, are in several others found to be inadequate. As to the use of local herbs, whereas the local tradition has an amazing knowledge of local flora--the knowledge about properties of plants is in many cases incomplete. There are several reasons that may explain how and why these weaknesses have set in. 1st, the local traditions are 'oral' and in the natural course of things, oral traditions the world over have been found to decay over time. A 2nd, external, reason for the current decay of local traditions is the derision, neglect, and oppression they have suffered due to the intolerance of western scientific tradition. A 3rd reason for weaknesses in the local health stream is the breakdown of active links, during the last few centuries, with the mainstream science of Ayurveda.

  15. Cosmological models and the brightness profile of distant galaxies

    NASA Astrophysics Data System (ADS)

    Olivares-Salaverri, I.; Ribeiro, Marcelo B.

    2010-11-01

    This work aims to determine the feasibility of an assumed cosmological model by means of a detailed analysis of the brightness profiles of distant galaxies. Starting from the theory of Ellis & Perry (1979) connecting the angular diameter distance obtained from a relativistic cosmological model and the detailed photometry of galaxies, we assume the presently most accepted cosmology with Λ ¬ = 0 and seek to predict the brightness profile of a galaxy in a given redshift z. To do so, we have to make assumptions concerning the galactic brightness structure and evolution, assuming a scenario where the specific emitted surface brightness Be,νe can be characterized as, Be,νe (r,z) = B0(z)J(νe,z)f[r(z)/a(z)]. Here r is the intrinsic galactic radius, νe the emitted frequency, B0(z) the central surface brightness, J(νe,z) the spectral energy distribution (SED), f[r(z)/a(z)] characterizes the shape of the surface profile distribution and a(z) is the scaling radius. The dependence on z is due to the galactic evolution. As spacetime curvature affects the received surface brightness, the reciprocity theorem (Ellis 1971) allows us to predict the theoretical received surface brightness. So, we are able to compare the theoretical surface brightness with its equivalent observational data already available for high redshift galaxies in order to test the consistency of the assumed cosmological model. The function f[r(z)/a(z)] is represented in the literature by various different shapes, like the Hubble, Hubble-Oemler and Abell-Mihalas single parameter profiles, characterizing the galactic surface brightness quite well when the disk or bulge dependence is dominant. Sérsic and core-Sérsic profiles use two or more parameters and reproduce the galactic profile almost exactly (Trujillo et al. 2004). If we consider all wavelengths, the theory tells us that the total intensity is equal to the surface brightness, so the chosen bandwidth should include most of the SED. In order to

  16. High-speed CuBr brightness amplifier beam profile

    NASA Astrophysics Data System (ADS)

    Evtushenko, G. S.; Torgaev, S. N.; Trigub, M. V.; Shiyanov, D. V.; Evtushenko, T. G.; Kulagin, A. E.

    2017-01-01

    This paper addresses the experimental study of the beam profile of the CuBr brightness amplifier operating at a wide range of pulse repetition frequencies. The use of a medium-size gas discharge tube (2 cm) ensures the operation of the brightness amplifier both at typical PRFs (520 kHz) and at higher PRFs (up to 100 kHz), either with or without HBr additive. The effect of the active additive on the beam profile is demonstrated. The testing results on kinetic modeling of radial processes in the laser (brightness amplifier) plasma are also discussed.

  17. Bright single photons for light-matter interaction

    NASA Astrophysics Data System (ADS)

    Wu, Chih-Hsiang; Wu, Tsung-Yao; Yeh, Yung-Chin; Liu, Po-Hui; Chang, Chin-Hsuan; Liu, Chiao-Kai; Cheng, Ting; Chuu, Chih-Sung

    2017-08-01

    Single photons of subnatural linewidth and high spectral brightness are necessary for efficient light-matter interaction at the single-photon level, which lies at the heart of many quantum photonic technologies. Here we demonstrate a bright source of single photons with subnatural linewidth, controllable waveforms, and a high spectral brightness of 3.67 ×105 s -1mW -1MHz -1. The interaction between the single photons and atoms is demonstrated by the controlled absorption of the single photons in an atomic vapor. Our work has potential applications in quantum information technologies.

  18. The 'Brightness Rules' alternative conception for light bulb circuits

    NASA Astrophysics Data System (ADS)

    Bryan, Joel A.; Stuessy, Carol

    2006-11-01

    An alternative conception for the observed differences in light bulb brightness was revealed during an unguided inquiry investigation in which prospective elementary teachers placed identical bulbs in series, parallel, and combination direct current circuits. Classroom observations, document analyses, and video and audio transcriptions led to the discovery of this alternative conception, appropriately christened 'Brightness Rules'. Assessments administered three weeks after the activity confirmed that several prospective teachers maintained the 'Brightness Rules' conception even after instructor-led intervention. Implications of the discovery of this alternative conception are discussed with respect to a previously administered assessment question that could not identify the presence of this alternative conception.

  19. ECR Ion Source for a High-Brightness Cyclotron

    NASA Astrophysics Data System (ADS)

    Comeaux, Justin; McIntyre, Peter; Assadi, Saeed

    2011-10-01

    New technology is being developed for high-brightness, high-current cyclotrons with performance benefits for accelerator-driven subcritical fission power, medical isotope production, and proton beam cancer therapy. This paper describes the design for a 65 kV electron cyclotron resonance (ECR) ion source that will provide high-brightness beam for injection into the cyclotron. The ion source is modeled closely upon the one that is used at the Paul Scherrer Institute. Modifications are being made to provide enhanced brightness and compatibility for higher-current operation.

  20. Traditional medicine and genomics

    PubMed Central

    Joshi, Kalpana; Ghodke, Yogita; Shintre, Pooja

    2010-01-01

    ‘Omics’ developments in the form of genomics, proteomics and metabolomics have increased the impetus of traditional medicine research. Studies exploring the genomic, proteomic and metabolomic basis of human constitutional types based on Ayurveda and other systems of oriental medicine are becoming popular. Such studies remain important to developing better understanding of human variations and individual differences. Countries like India, Korea, China and Japan are investing in research on evidence-based traditional medicines and scientific validation of fundamental principles. This review provides an account of studies addressing relationships between traditional medicine and genomics. PMID:21829298

  1. THE SLOAN BRIGHT ARCS SURVEY: DISCOVERY OF SEVEN NEW STRONGLY LENSED GALAXIES FROM z = 0.66-2.94

    SciTech Connect

    Kubo, Jeffrey M.; Allam, Sahar S.; Drabek, Emily; Lin, Huan; Tucker, Douglas; Buckley-Geer, Elizabeth J.; Diehl, H. Thomas; Soares-Santos, Marcelle; Hao Jiangang; Kubik, Donna; Annis, James; Frieman, Joshua A.; Wiesner, Matthew; West, Anderson

    2010-12-01

    We report the discovery of seven new, very bright gravitational lens systems from our ongoing gravitational lens search, the Sloan Bright Arcs Survey (SBAS). Two of the systems are confirmed to have high source redshifts z = 2.19 and z = 2.94. Three other systems lie at intermediate redshift with z = 1.33, 1.82, 1.93 and two systems are at low redshift z = 0.66, 0.86. The lensed source galaxies in all of these systems are bright, with i-band magnitudes ranging from 19.73 to 22.06. We present the spectrum of each of the source galaxies in these systems along with estimates of the Einstein radius for each system. The foreground lens in most systems is identified by a red sequence based cluster finder as a galaxy group; one system is identified as a moderately rich cluster. In total, SBAS has now discovered 19 strong lens systems in the SDSS imaging data, 8 of which are among the highest surface brightness z {approx_equal} 2-3 galaxies known.

  2. HUBBLE FINDS MANY BRIGHT CLOUDS ON URANUS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A recent Hubble Space Telescope view reveals Uranus surrounded by its four major rings and by 10 of its 17 known satellites. This false-color image was generated by Erich Karkoschka using data taken on August 8, 1998, with Hubble's Near Infrared Camera and Multi-Object Spectrometer. Hubble recently found about 20 clouds - nearly as many clouds on Uranus as the previous total in the history of modern observations. The orange-colored clouds near the prominent bright band circle the planet at more than 300 mph (500 km/h), according to team member Heidi Hammel (MIT). One of the clouds on the right-hand side is brighter than any other cloud ever seen on Uranus. The colors in the image indicate altitude. Team member Mark Marley (New Mexico State University) reports that green and blue regions show where the atmosphere is clear and sunlight can penetrate deep into Uranus. In yellow and grey regions the sunlight reflects from a higher haze or cloud layer. Orange and red colors indicate very high clouds, such as cirrus clouds on Earth. The Hubble image is one of the first images revealing the precession of the brightest ring with respect to a previous image [LINK to PRC97-36a]. Precession makes the fainter part of the ring (currently on the upper right-hand side) slide around Uranus once every nine months. The fading is caused by ring particles crowding and hiding each other on one side of their eight-hour orbit around Uranus. The blue, green and red components of this false-color image correspond to exposures taken at near-infrared wavelengths of 0.9, 1.1, and 1.7 micrometers. Thus, regions on Uranus appearing blue, for example, reflect more sunlight at 0.9 micrometer than at the longer wavelengths. Apparent colors on Uranus are caused by absorption of methane gas in its atmosphere, an effect comparable to absorption in our atmosphere which can make distant clouds appear red. Credit: Erich Karkoschka (University of Arizona) and NASA

  3. Data Rich, Information Poor

    SciTech Connect

    Kaplan, P.G.; Rautman, C.A.

    1998-11-09

    Surviving in a data-rich environment means understanding the difference between data and information. This paper reviews an environmental case study that illustrates that understanding and shows its importance. In this study, a decision problem was stated in terms of au economic-objective fimction. The function contains a term that defines the stochastic relationship between the decision and the information obtained during field chamctetition for an environmental contaminant. Data is defied as samples drawn or experimental realizations of a mudom fimction. Information is defined as the quantitative change in the value of the objective fiction as a result of the sample.

  4. Identifying Bright X-Ray Beasts

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2017-10-01

    Ultraluminous X-ray sources (ULXs) are astronomical sources of X-rays that, while dimmer than active galactic nuclei, are nonetheless brighter than any known stellar process. What are these beasts and why do they shine so brightly?Exceeding the LimitFirst discovered in the 1980s, ULXs are rare sources that have nonetheless been found in all types of galaxies. Though the bright X-ray radiation seems likely to be coming from compact objects accreting gas, theres a problem with this theory: ULXs outshine the Eddington luminosity for stellar-mass compact objects. This means that a stellar-mass object couldnt emit this much radiation isotropically without blowing itself apart.There are two alternative explanations commonly proposed for ULXs:Rather than being accreting stellar-mass compact objects, they are accreting intermediate-mass black holes. A hypothetical black hole of 100 solar masses or more would have a much higher Eddington luminosity than a stellar-mass black hole, making the luminosities that we observe from ULXs feasible.An example of one of the common routes the authors find for a binary system to become a ULX. In this case, the binary begins as two main sequence stars. As one star evolves off the main sequence, the binary undergoes a common envelope phase and a stage of mass transfer. The star ends its life as a supernova, and the resulting neutron star then accretes matter from the main sequence star as a ULX. [Wiktorowicz et al. 2017]They are ordinary X-ray binaries (a stellar-mass compact object accreting matter from a companion star), but they are undergoing a short phase of extreme accretion. During this time, their emission is beamed into jets, making them appear brighter than the Eddington luminosity.Clues from a New DiscoveryA few years ago, a new discovery shed some light on ULXs: M82 X-2, a pulsing ULX. Two more pulsing ULXs have been discovered since then, demonstrating that at least some ULXs contain pulsars i.e., neutron stars as the

  5. Black African Traditional Mathematics

    ERIC Educational Resources Information Center

    Zaslavsky, Claudia

    1970-01-01

    Discusses the traditional number systems and the origin of the number names used by several African peoples living south of the Sahara. Also included are limitations in African mathematical development, and possible topics for research. (RP)

  6. The "Natural Law Tradition."

    ERIC Educational Resources Information Center

    Finnis, John

    1986-01-01

    A discussion of natural law outlines some of the theory and tradition surrounding it and examines its relationship to the social science and legal curriculum and to the teaching of jurisprudence. (MSE)

  7. Traditional midwives in Botswana.

    PubMed

    Staugard, F

    1985-01-01

    Botswanan women tend to consciously opt for home deliveries, even in areas where modern maternity care facilities are easily accessible. Approximately 40% of deliveries in Botswana occur outside of institutions (55% in rural areas and 23% in urban areas) and are generally assisted by traditional midwives. To gain more information on this phenomenon, the 175 identified traditional midwives in 2 health regions of Botswana were interviewed. All midwives were female, the majority were over 50 years of age, and 80% were illiterate. 38% were married and 42% were widowed; 67% had 4 or more children. 59% practiced the traditional Tswana religion. 82% of the midwives interviewed indicated they had performed only 5-6 deliveries in the 1 year preceding the survey, suggesting a decline in their level of professional activity. Only 58% received a fee for their services; in most of these cases, the fee was minimal or in kind. Interestingly, 90% of traditional midwives expressed a positive attitude toward cooperation with the modern health care system. A more intensive interview with 59 of these traditional midwives indicated that 81% had no contact with their clients during the prenatal period. 95% showed a total lack of knowledge of the female reproductive system, yet all were able to identify signs of a high risk delivery and willing to refer these cases to a modern health facility. 76% were informed about family planning, although they indicated they refer clients to clinics for supplies, and all were supportive of breastfeeding for at least 1 year. As a group, Botswanan traditional midwives have specific conceptions regarding food taboos during pregnancy (e.g., avoidance of meat and eggs) that can place pregnant women at risk of protein deficiencies. Overall, these findings indicate that the traditional midwife in Tswana society cannot be regarded as a well-defined health worker, as is the case with traditional healers.

  8. Lithologic variation within bright material on Vesta revealed by linear spectral unmixing

    NASA Astrophysics Data System (ADS)

    Zambon, F.; Tosi, F.; Carli, C.; De Sanctis, M. C.; Blewett, D. T.; Palomba, E.; Longobardo, A.; Frigeri, A.; Ammannito, E.; Russell, C. T.; Raymond, C. A.

    2016-07-01

    Vesta's surface is mostly composed of pyroxene-rich lithologies compatible with howardite, eucrite and diogenite (HED) meteorites (e.g., McCord et al. [1970] Science, 168, 1445-1447; Feierberg & Drake [1980] Science, 209, 805-807). Data provided by the Visible and Infrared (VIR) spectrometer, onboard the NASA Dawn spacecraft, revealed that all Vesta reflectance spectra show absorption bands at ∼0.9 and ∼1.9 μm, which are typical of iron-bearing pyroxenes (De Sanctis et al. [2012] Science, 336, 697-700). Other minerals may be present in spectrally significant concentrations; these include olivine and opaque phases like those found in carbonaceous chondrites. These additional components modify the dominant pyroxene absorptions. We apply linear spectral unmixing on bright material (BM) units of Vesta to identify HEDs and non-HED phases. We explore the limits of applicability of linear spectral unmixing, testing it on laboratory mixtures. We find that the linear method is applicable at the VIR pixel resolution and it is useful when the surface is composed of pyroxene-rich lithologies containing moderate quantities of carbonaceous chondrite, olivine, and plagioclase. We found three main groups of BM units: eucrite-rich, diogenite-rich, and olivine-rich. For the non-HED spectral endmember, we choose either olivine or a featureless component. Our work confirms that Vesta's surface contains a high content of pyroxenes mixed with a lower concentration of other phases. In many cases, the non-HED endmember that gives the best fit is the featureless phase, which causes a reduction in the strength of both bands. The anticorrelation between albedo and featureless endmember indicates that this phase is associated with low-albedo, CC-like opaque material. Large amounts of olivine have been detected in Bellicia, Arruntia and BU14 BM units. Other sites present low olivine content (<30%) mostly with a high concentration of diogenite.

  9. Bright emission from a random Raman laser

    PubMed Central

    Hokr, Brett H.; Bixler, Joel N.; Cone, Michael T.; Mason, John D.; Beier, Hope T.; Noojin, Gary D.; Petrov, Georgi I.; Golovan, Leonid A.; Thomas, Robert J.; Rockwell, Benjamin A.; Yakovlev, Vladislav V.

    2014-01-01

    Random lasers are a developing class of light sources that utilize a highly disordered gain medium as opposed to a conventional optical cavity. Although traditional random lasers often have a relatively broad emission spectrum, a random laser that utilizes vibration transitions via Raman scattering allows for an extremely narrow bandwidth, on the order of 10 cm−1. Here we demonstrate the first experimental evidence of lasing via a Raman interaction in a bulk three-dimensional random medium, with conversion efficiencies on the order of a few percent. Furthermore, Monte Carlo simulations are used to study the complex spatial and temporal dynamics of nonlinear processes in turbid media. In addition to providing a large signal, characteristic of the Raman medium, the random Raman laser offers us an entirely new tool for studying the dynamics of gain in a turbid medium. PMID:25014073

  10. Detail of Bright Angel stone vault, containing condenser, Hoffman condensation ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of Bright Angel stone vault, containing condenser, Hoffman condensation pump, Jennings vacuum heating pump, and misc. pipes and valves. - Grand Canyon Village Utilities, Grand Canyon National Park, Grand Canyon Village, Coconino County, AZ

  11. Western Edge of Cape York, with Bright Vein

    NASA Image and Video Library

    2011-12-07

    NASA Mars Exploration Rover Opportunity recorded this view of the western edge of Cape York, a segment of the rim of Endeavour Crater. A bright vein, informally named Homestake, is visible on the right side of the image.

  12. Significant increase in the optical brightness of V2492 Cyg

    NASA Astrophysics Data System (ADS)

    Ibryamov, Sunay; Semkov, Evgeni

    2017-03-01

    We observed a recent increase in the optical brightness of the young eruptive star V2492 Cyg using the 2-m and the 50/70-cm Schmidt telescopes administered by National Astronomical Observatory Rozhen in Bulgaria.

  13. Dark Murky Clouds in the Bright Milky Way

    NASA Image and Video Library

    2011-08-24

    This infrared image from NASA Wide-field Infrared Survey Explorer shows exceptionally cold, dense cloud cores seen in silhouette against the bright diffuse infrared glow of the plane of the Milky Way galaxy.

  14. Yellow steam and electrical pipes across from Bright Angel Lodge. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Yellow steam and electrical pipes across from Bright Angel Lodge. Note control valve to right of control box, view E. - Grand Canyon Village Utilities, Grand Canyon National Park, Grand Canyon Village, Coconino County, AZ

  15. South and west elevations of Bright Angel boiler house. Red ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    South and west elevations of Bright Angel boiler house. Red Horse log cabin visible in background. - Grand Canyon Village Utilities, Grand Canyon National Park, Grand Canyon Village, Coconino County, AZ

  16. Perspective of Bright Angel stone vault, view south, with HAER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Perspective of Bright Angel stone vault, view south, with HAER field team measuring (Michael Lee and Dominic Duran foreground, Christopher Marston rear). - Grand Canyon Village Utilities, Grand Canyon National Park, Grand Canyon Village, Coconino County, AZ

  17. Bright Angel stone vault, with HAER field team members Dominic ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Bright Angel stone vault, with HAER field team members Dominic Duran, Christopher Marston, and Michael Lee (l to r). - Grand Canyon Village Utilities, Grand Canyon National Park, Grand Canyon Village, Coconino County, AZ

  18. Zernike analysis of all-sky night brightness maps.

    PubMed

    Bará, Salvador; Nievas, Miguel; Sánchez de Miguel, Alejandro; Zamorano, Jaime

    2014-04-20

    All-sky night brightness maps (calibrated images of the night sky with hemispherical field-of-view (FOV) taken at standard photometric bands) provide useful data to assess the light pollution levels at any ground site. We show that these maps can be efficiently described and analyzed using Zernike circle polynomials. The relevant image information can be compressed into a low-dimensional coefficients vector, giving an analytical expression for the sky brightness and alleviating the effects of noise. Moreover, the Zernike expansions allow us to quantify in a straightforward way the average and zenithal sky brightness and its variation across the FOV, providing a convenient framework to study the time course of these magnitudes. We apply this framework to analyze the results of a one-year campaign of night sky brightness measurements made at the UCM observatory in Madrid.

  19. Bright Particle in Hole Dug by Scooping of Martian Soil

    NASA Image and Video Library

    2012-10-18

    The mission science team assessed the bright particles in this scooped pit to be native Martian material rather than spacecraft debris as seen in this image from NASA Mars rover Curiosity as it collected its second scoop of Martian soil.

  20. Female butterflies prefer males bearing bright iridescent ornamentation

    PubMed Central

    Kemp, Darrell J

    2007-01-01

    Butterflies are among nature's most colourful animals, and provide a living showcase for how extremely bright, chromatic and iridescent coloration can be generated by complex optical mechanisms. The gross characteristics of male butterfly colour patterns are understood to function for species and/or sex recognition, but it is not known whether female mate choice promotes visual exaggeration of this coloration. Here I show that females of the sexually dichromatic species Hypolimnas bolina prefer conspecific males that possess bright iridescent blue/ultraviolet dorsal ornamentation. In separate field and enclosure experiments, using both dramatic and graded wing colour manipulations, I demonstrate that a moderate qualitative reduction in signal brightness and chromaticity has the same consequences as removing the signal entirely. These findings validate a long-held hypothesis, and argue for the importance of intra- versus interspecific selection as the driving force behind the exaggeration of bright, iridescent butterfly colour patterns. PMID:17284412

  1. Proposal for a High-Brightness Pulsed Electron Source

    SciTech Connect

    Zolotorev, Max; Commins, Eugene D.; Heifets, Sam; Sannibale,Fernando

    2006-03-15

    We propose a novel scheme for a high-brightness pulsedelectron source, which has the potential for many useful applications inelectron microscopy, inverse photo-emission, low energy electronscattering experiments, and electron holography. A description of theproposed scheme is presented.

  2. Brightness differences influence the evaluation of affective pictures.

    PubMed

    Lakens, Daniël; Fockenberg, Daniel A; Lemmens, Karin P H; Ham, Jaap; Midden, Cees J H

    2013-01-01

    We explored the possibility of a general brightness bias: brighter pictures are evaluated more positively, while darker pictures are evaluated more negatively. In Study 1 we found that positive pictures are brighter than negative pictures in two affective picture databases (the IAPS and the GAPED). Study 2 revealed that because researchers select affective pictures on the extremity of their affective rating without controlling for brightness differences, pictures used in positive conditions of experiments were on average brighter than those used in negative conditions. Going beyond correlational support for our hypothesis, Studies 3 and 4 showed that brighter versions of neutral pictures were evaluated more positively than darker versions of the same picture. Study 5 revealed that people categorised positive words more quickly than negative words after a bright picture prime, and vice versa for negative pictures. Together, these studies provide strong support for the hypotheses that picture brightness influences evaluations.

  3. A model function for ocean microwave brightness temperatures

    NASA Technical Reports Server (NTRS)

    Wentz, F. J.

    1983-01-01

    A relatively simple, yet accurate, relationship between the microwave brightness temperature of the ocean and conventional oceanographic and meteorological parameters is derived. The equation for the brightness temperature upwelling from the sea surface through the intervening atmosphere is obtained, considering radiative emission and scattering by the sea surface along with radiative absorption and emission by the atmosphere. A number of approximations are applied to the integral brightness temperature equation and its supporting equations in order to obtain a simple equation for the brightness temperature that does not contain integrals. Values for a number of atmospheric parameters are determined, including temperature sensitivities, oxygen opacity, water vapor and liquid water normalized absorption coefficients, and effective columnar height. The sea surface emissivity model is then considered, modelling the sea surface as a composite of foam-free rough water and foam patches.

  4. Visible Color and Photometry of Bright Materials on Vesta

    NASA Technical Reports Server (NTRS)

    Schroder, S. E.; Li, J. Y.; Mittlefehldt, D. W.; Pieters, C. M.; De Sanctis, M. C.; Hiesinger, H.; Blewett, D. T.; Russell, C. T.; Raymond, C. A.; Keller, H. U.

    2012-01-01

    The Dawn Framing Camera (FC) collected images of the surface of Vesta at a pixel scale of 70 m in the High Altitude Mapping Orbit (HAMO) phase through its clear and seven color filters spanning from 430 nm to 980 nm. The surface of Vesta displays a large diversity in its brightness and colors, evidently related to the diverse geology [1] and mineralogy [2]. Here we report a detailed investigation of the visible colors and photometric properties of the apparently bright materials on Vesta in order to study their origin. The global distribution and the spectroscopy of bright materials are discussed in companion papers [3, 4], and the synthesis results about the origin of Vestan bright materials are reported in [5].

  5. THE RELATION BETWEEN VISUAL ACUITY AND BRIGHTNESS DISCRIMINATION

    PubMed Central

    Hendley, Charles D.

    1948-01-01

    1. Visual acuity depends on the brightness contrast between test object and background; and conversely, brightness discrimination depends on the target size. Both functions vary with the brightness of the background. Measurements with rectangular targets of length-width ratio 2 were made over a range of sizes, contrasts, and brightnesses sufficient to determine the relations among these three variables. The rectangles were from 2' to 50' wide; the contrast fraction, ΔI/I, ranged from 0.01 to 40; the background brightness varied from 0.0001 to 2500 millilamberts. 2. When ΔI/I or visual acuity is plotted as a function of brightness the data do, in general, follow Hecht's equation. The departure from a simple photochemical theory which the larger targets show is probably due to changes in the functional retinal mosaic with changing brightness. 3. In general also, the relation between visual acuity and brightness, at selected contrasts, fits Hecht's derivation. At low contrasts, as the brightness is reduced a point is reached at which the test object becomes invisible at any size. 4. No simple relation emerges from the data relating visual acuity to contrast, at set levels of illumination. Over only a very short range are visual acuity and contrast directly related. At high contrasts, visual acuity reaches a maximum, whereas at low visual acuity, ΔI/I reaches a minimum which cannot be passed regardless of size. 5. The shape of the curves relating ΔI/I to brightness is not significantly altered by changing the exposure time. There is some evidence to show that a 3 second exposure of the target is equivalent to two looks of 0.2 second each. 6. In all these studies the thresholds were determined by a frequency of seeing method, and the data have been considered in terms of a quantum theory of threshold seeing. It was found that a threshold response involves between four and eight independent critical events, which are largely independent of size, brightness, and

  6. The sonographic "bright band sign" of splenic infarction.

    PubMed

    Llewellyn, Michael E; Jeffrey, R Brooke; DiMaio, Michael A; Olcott, Eric W

    2014-06-01

    To evaluate the frequency of the "bright band sign" in patients with splenic infarcts as well as control patients and to thereby assess whether the bright band sign has potential utility as a sonographic sign of splenic infarction. Using an electronic search engine and image review, 37 patients were retrospectively identified with noncystic parenchymal splenic infarcts on sonography. Nineteen abnormal control patients with noninfarcted splenic lesions on sonography and 100 normal control patients with sonographically normal spleens were also identified. The sonographic appearance of each splenic lesion was evaluated by 2 reviewers and assessed for the bright band sign, defined as thin specular reflectors perpendicular to the sound beam within hypoechoic parenchymal lesions, and for the presence or absence of the classic sonographic appearance of splenic infarction. Possible histologic counterparts of the bright band sign were assessed in archival infarct specimens. The bright band sign was present in 34 (91.9%; 95% confidence interval [CI], 78.1%-98.3%) of 37 patients with splenic infarcts on sonography, including 12 (85.7%; 95% CI, 57.2%-98.2%) of 14 with classic and 22 (95.7%; 95% CI, 78.1%-99.9%) of 23 with nonclassic infarct appearances. No normal or abnormal control patients had the bright band sign. Histologic sections suggested that preserved splenic trabeculae within infarcts may generate the bright band sign. The bright band sign is a potentially useful sonographic sign of splenic infarction, which may confer additional sensitivity and specificity and may be particularly helpful with infarcts having nonclassic appearances. © 2014 by the American Institute of Ultrasound in Medicine.

  7. Sky Brightness During Eclipses: A Compendium from the Literature

    DTIC Science & Technology

    1974-08-05

    Sky Brightness 90 Tables 29. Optical Dimensions o. 30. Data on Apparatus 31. Intensity of Emissions 32. Recordings Made During Eclipse and...Compendium From The Literature i. a:\\KR\\i. The brightness of the sky represents the optical ambient field in which objects are imbedded. Thus detection...instrument used was Pyranometer A. P. O. No. 5 (see 19) partially rebuilt by inserting a new thermopile, consisting of four tellurium-platinum thermo

  8. Sky Brightness Analysis using a Million GEODSS Observations

    NASA Astrophysics Data System (ADS)

    Mandeville, W. Jody; McLaughlin, Tim; Six, Steve; Hollm, Rick

    2012-09-01

    Brightness of the sky background due to lunar phase and location can dramatically affect the limiting magnitude of astronomical detectors. Formerly, theoretical models have attained limited data sets with 10-20% differences between model and observation. This paper compares and contrasts previous investigations with over a million data points collected from various GEODSS sites located around the world and attempts to refine predictive modeling of sky brightness for use in scheduling as well as modeling and simulation tools.

  9. Catalogue of Galactic globular-cluster surface-brightness profiles

    NASA Technical Reports Server (NTRS)

    Trager, S. C.; King, Ivan R.; Djorgovski, S.

    1995-01-01

    We present a catalogue of surface-brightness profiles (SBPs) of 125 Galactic globular clusters, the largest such collection ever gathered. The SPBs are constructed from generally inhomogeneous data, but are based heavily on the Berkeley Global Cluster Survey of Djorgovski & King. All but four of the SBPs have photometric zero points. We derive central surface brightness, King-model concentrations, core radii, half-light, and other fraction-of-light radii where data permit, and we briefly discuss their use.

  10. Laser-heated X-ray flashlamp brightness measurements

    SciTech Connect

    Matthews, D.L.; Campbell, E.M.; Hagelstein, P.; Halsey, W.; Kauffman, R.L.; Koppel, L.; Phillion, D.; Price, R.; Toor, A.

    1983-12-01

    The authors present measurements of the X-ray emission characteristics of laser-irradiated flashlamp foils which are candidates to produce by resonant photoexcitation a population inversion in either a neon or fluorine lasant gas. Using the Shiva 1.06 ..mu.. laser, the authors heated Fe, Cr, and Ni foils to study the brightness and centroid energies of X-ray lines stemming from L-M transitions. Results indicate that appropriately bright and uniform sources can be produced.

  11. Global View of the Bright Material on Vesta

    NASA Technical Reports Server (NTRS)

    Zambon, F.; DeSanctis, C.; Schroeder, S.; Tosi, F.; Li, J.-Y.; Longobardo, A.; Ammannito, E.; Blewett, D. T.; Palomba, E.; Capaccioni, F.; hide

    2014-01-01

    At 525 km in mean diameter, Vesta is the second-most massive and one of the brightest asteroids of the main-belt. Here we give a global view of the bright material (BM) units on Vesta. We classified the BMs according to the normal visual albedo. The global albedo map of Vesta allows to be divided the surface into three principal types of terrains: bright regions, dark regions and intermediate regions. The distribution of bright regions is not uniform. The mid-southern latitudes contain the most bright areas, while the northern hemisphere is poor in bright regions. The analysis of the spectral parameters and the normal visual albedo show a dependence between albedo and the strength (depth) of ferrous iron absorption bands, strong bands correspond with high albedo units. Vesta's average albedo is 0.38, but there are bright material whose albedo can exceed 0.50. Only the E-Type asteroids have albedos comparable to those of the BMs on Vesta. The Dawn mission observed a large fraction of Vesta's surface at high spatial resolution, allowing a detailed study of the morphology and mineralogy of it. In particular, reflectance spectra provided by the Visible and InfraRed spectrometer (VIR), confirmed that Vesta's mineralogy is dominated by pyroxenes. All Vesta spectra show two strong absorption bands at approx 0.9 and 1.9 micron, typical of the pyroxenes and associated with the howardite, eucrite and diogenite (HED) meteorites.

  12. An observational correlation between stellar brightness variations and surface gravity.

    PubMed

    Bastien, Fabienne A; Stassun, Keivan G; Basri, Gibor; Pepper, Joshua

    2013-08-22

    Surface gravity is a basic stellar property, but it is difficult to measure accurately, with typical uncertainties of 25 to 50 per cent if measured spectroscopically and 90 to 150 per cent if measured photometrically. Asteroseismology measures gravity with an uncertainty of about 2 per cent but is restricted to relatively small samples of bright stars, most of which are giants. The availability of high-precision measurements of brightness variations for more than 150,000 stars provides an opportunity to investigate whether the variations can be used to determine surface gravities. The Fourier power of granulation on a star's surface correlates physically with surface gravity: if brightness variations on timescales of hours arise from granulation, then such variations should correlate with surface gravity. Here we report an analysis of archival data that reveals an observational correlation between surface gravity and root mean squared brightness variations on timescales of less than eight hours for stars with temperatures of 4,500 to 6,750 kelvin, log surface gravities of 2.5 to 4.5 (cgs units) and overall brightness variations of less than three parts per thousand. A straightforward observation of optical brightness variations therefore allows a determination of the surface gravity with a precision of better than 25 per cent for inactive Sun-like stars at main-sequence to giant stages of evolution.

  13. The Influence of Microphysical Cloud Parameterization on Microwave Brightness Temperatures

    NASA Technical Reports Server (NTRS)

    Skofronick-Jackson, Gail M.; Gasiewski, Albin J.; Wang, James R.; Zukor, Dorothy J. (Technical Monitor)

    2000-01-01

    The microphysical parameterization of clouds and rain-cells plays a central role in atmospheric forward radiative transfer models used in calculating passive microwave brightness temperatures. The absorption and scattering properties of a hydrometeor-laden atmosphere are governed by particle phase, size distribution, aggregate density., shape, and dielectric constant. This study identifies the sensitivity of brightness temperatures with respect to the microphysical cloud parameterization. Cloud parameterizations for wideband (6-410 GHz observations of baseline brightness temperatures were studied for four evolutionary stages of an oceanic convective storm using a five-phase hydrometeor model in a planar-stratified scattering-based radiative transfer model. Five other microphysical cloud parameterizations were compared to the baseline calculations to evaluate brightness temperature sensitivity to gross changes in the hydrometeor size distributions and the ice-air-water ratios in the frozen or partly frozen phase. The comparison shows that, enlarging the rain drop size or adding water to the partly Frozen hydrometeor mix warms brightness temperatures by up to .55 K at 6 GHz. The cooling signature caused by ice scattering intensifies with increasing ice concentrations and at higher frequencies. An additional comparison to measured Convection and Moisture LA Experiment (CAMEX 3) brightness temperatures shows that in general all but, two parameterizations produce calculated T(sub B)'s that fall within the observed clear-air minima and maxima. The exceptions are for parameterizations that, enhance the scattering characteristics of frozen hydrometeors.

  14. Synthesizing SMOS Zero-Baselines with Aquarius Brightness Temperature Simulator

    NASA Technical Reports Server (NTRS)

    Colliander, A.; Dinnat, E.; Le Vine, D.; Kainulainen, J.

    2012-01-01

    SMOS [1] and Aquarius [2] are ESA and NASA missions, respectively, to make L-band measurements from the Low Earth Orbit. SMOS makes passive measurements whereas Aquarius measures both passive and active. SMOS was launched in November 2009 and Aquarius in June 2011.The scientific objectives of the missions are overlapping: both missions aim at mapping the global Sea Surface Salinity (SSS). Additionally, SMOS mission produces soil moisture product (however, Aquarius data will eventually be used for retrieving soil moisture too). The consistency of the brightness temperature observations made by the two instruments is essential for long-term studies of SSS and soil moisture. For resolving the consistency, the calibration of the instruments is the key. The basis of the SMOS brightness temperature level is the measurements performed with the so-called zero-baselines [3]; SMOS employs an interferometric measurement technique which forms a brightness temperature image from several baselines constructed by combination of multiple receivers in an array; zero-length baseline defines the overall brightness temperature level. The basis of the Aquarius brightness temperature level is resolved from the brightness temperature simulator combined with ancillary data such as antenna patterns and environmental models [4]. Consistency between the SMOS zero-baseline measurements and the simulator output would provide a robust basis for establishing the overall comparability of the missions.

  15. Where to Find Young Bright Stars in Geosciences: GGD, NSU

    NASA Astrophysics Data System (ADS)

    Rakhmenkoulova, I. F.; Sharapov, V. N.

    2004-12-01

    Geology and Geophysics Department (GGD) of Novosibirsk State University (NSU) can be regarded as infant, because it was founded in 1962. On the other hand, if to judge by what have been done - it is not only full-fledged, but well-known department. The unique location and specific educational and scientific traditions make GGD a famous school not only in Siberia, but in Russia, and all over the world. What are the tips to prepare bright stars in geosciences? 1.NSU is located in Academgorodok (Novosibirsk scientific center), unique place in Siberia, where more than 20 scientific institutions are located. This makes the University different from other schools in Russia. Famous Russian scientists, including members of RAS, together with foreign professors give lectures and seminars for NSU students. 2.The bright star hunting starts far below the NSU level. Each year in April there is a special event in Academgorodok -`Geologic Olympiad', where children of all Russian regions, as well as ex-Soviet republics are gathered together to submit their papers, to discuss most interesting geoscience problems and to win prizes for their knowledge. The youngest stars happen to be only 6-7 years old. The event is sponsored by NSU, UIGGM, and the Ministry of Natural Resources. The brightest geostars are grown from `Geologic Olympiad' participants. 3.There is special physics-mathematical high school in Academgorodok. Each summer this school gathers young stars from farthest Siberian and Far East regions and gives classes and seminars in mathematics, physics, chemistry and geology. As the result the most talented children become the students of this school (for two years). The school in turn supplies GGD with the students. 4.NSU has the study curriculum different from other universities in Russia. That is why the entrance examinations are much more difficult as compared to other schools and are taken in July (a month earlier then at other universities). However the entrance

  16. Results of Satellite Brightness Modeling Using Kringing Optimized Interpolation

    NASA Astrophysics Data System (ADS)

    Weeden, C.; Hejduk, M.

    At the 2005 AMOS conference, Kriging Optimized Interpolation (KOI) was presented as a tool to model satellite brightness as a function of phase angle and solar declination angle (J.M Okada and M.D. Hejduk). Since November 2005, this method has been used to support the tasking algorithm for all optical sensors in the Space Surveillance Network (SSN). The satellite brightness maps generated by the KOI program are compared to each sensor's ability to detect an object as a function of the brightness of the background sky and angular rate of the object. This will determine if the sensor can technically detect an object based on an explicit calculation of the object's probability of detection. In addition, recent upgrades at Ground-Based Electro Optical Deep Space Surveillance Sites (GEODSS) sites have increased the amount and quality of brightness data collected and therefore available for analysis. This in turn has provided enough data to study the modeling process in more detail in order to obtain the most accurate brightness prediction of satellites. Analysis of two years of brightness data gathered from optical sensors and modeled via KOI solutions are outlined in this paper. By comparison, geo-stationary objects (GEO) were tracked less than non-GEO objects but had higher density tracking in phase angle due to artifices of scheduling. A statistically-significant fit to a deterministic model was possible less than half the time in both GEO and non-GEO tracks, showing that a stochastic model must often be used alone to produce brightness results, but such results are nonetheless serviceable. Within the Kriging solution, the exponential variogram model was the most frequently employed in both GEO and non-GEO tracks, indicating that monotonic brightness variation with both phase and solar declination angle is common and testifying to the suitability to the application of regionalized variable theory to this particular problem. Finally, the average nugget value, or

  17. Systematic variations in the spectral properties of bright regions on Mars

    NASA Technical Reports Server (NTRS)

    Murchie, Scott; Mustard, John; Bishop, Janice; Head, James; Pieters, Carle; Erard, Stephane

    1992-01-01

    The color and albedo of the martian surface define two basic surface units, dark gray material interpreted as relatively unaltered 'rock' and bright reddish material interpreted as weathered 'soil'. Understanding the processes contributing to soil formation first requires assessment of the soil's composition and compositional diversity. We report first results of an investigation of the character and variability of Fe- and water-bearing phases in bright reddish materials using ISM data. We also explore implications of these results for chemical evolution of martian soil. Information on the composition and distribution of bright reddish material comes from three major sources: Viking images, measurements by the XRF and GCMS instruments on the Viking Landers, and spectroscopic data. The XRF experiment found nearly identical, Fe-rich major-element compositions comparable to weathered basalt. Soil water, amounting to approximately 1-3 wt. percent as measured by the GCMS, was liberated mostly by heating to greater than or equal to 350 C, suggesting that it is present in a chemically bound form. Spectroscopic studies have detected ferric oxide, probably hematite, as well as molecular water. However, the identities of major silicate phases have been controversial, with conflicting evidence regarding phyllosilicates. Two main interpretations of this evidence have been proposed: Weathering of basaltic glasses by H2O and CO2 formed a mixture of oxides, salts, and metastable phyllosilicates such as montmorillonite and 'palagonite' formed when basaltic melt contacted ground ice or water. Palagonite is a hydrated basaltic glass containing dispersed ferric oxide, recrystallized in varying degrees to phyllosilicates. Typically it is aphanitic, although some examples contain phenocrysts. In either case, eolian redistribution is thought to have resulted in the material's global homogenization. Imaging spectroscopic data returned by the ISM instrument on Phobos 2 provide a powerful

  18. Constraining Models of Evolved UV-Bright Stars in the M31 Bulge

    NASA Astrophysics Data System (ADS)

    Rosenfield, Philip

    2014-10-01

    We aim to use HST observations of M31 to generate the definitive data set for modeling the population of the UV-bright stars that contribute to the UV flux in old stellar populations (i.e., the "UV excess" seen in some elliptical galaxies and spiral bulges).We propose to place stringent observational constraints on the post-AGB (P-AGB) and post-early AGB (PE-AGB) phases of stellar evolution using a UV survey of M31's bulge. M31 is a critical laboratory for testing these models, as it hosts an old, metal-rich stellar population with high stellar densities such that even rare evolutionary phases are well-represented.We will (1) assemble a catalog of UV-bright stars in the center of M31 in F336W and F225W, extending out to ~0.7 kpc, to sample stellar populations with different metallicities; and (2) image a smaller 0.9 sqr-arcmin strip with ACS/SBC in F140LP, to image the regions with the highest density of rapidly-evolving P-AGB stars. The FUV imaging will allow us to separate the P-AGB from the PE-AGB. These observations will include thousands of UV-bright stars, increasing the size of existing samples by orders of magnitude.These new observations will drive revisions in models for post-HB evolution, which we will merge into new isochrone libraries and stellar population synthesis codes. The revisions will have important implications for AGB evolution, spectral evolution models of galaxies, and for mass loss on the RGB. The observations will also have a direct impact on interpreting (1) the UV flux from old stellar populations; (2) the emission line flux from M31's nuclear spiral; and (3) models of dust heating by old stellar populations.

  19. Systematic variations in the spectral properties of bright regions on Mars

    NASA Astrophysics Data System (ADS)

    Murchie, Scott; Mustard, John; Bishop, Janice; Head, James; Pieters, Carle; Erard, Stephane

    1993-09-01

    The color and albedo of the martian surface define two basic surface units, dark gray material interpreted as relatively unaltered 'rock' and bright reddish material interpreted as weathered 'soil'. Understanding the processes contributing to soil formation first requires assessment of the soil's composition and compositional diversity. We report first results of an investigation of the character and variability of Fe- and water-bearing phases in bright reddish materials using ISM data. We also explore implications of these results for chemical evolution of martian soil. Information on the composition and distribution of bright reddish material comes from three major sources: Viking images, measurements by the XRF and GCMS instruments on the Viking Landers, and spectroscopic data. The XRF experiment found nearly identical, Fe-rich major-element compositions comparable to weathered basalt. Soil water, amounting to approximately 1-3 wt. percent as measured by the GCMS, was liberated mostly by heating to greater than or equal to 350 C, suggesting that it is present in a chemically bound form. Spectroscopic studies have detected ferric oxide, probably hematite, as well as molecular water. However, the identities of major silicate phases have been controversial, with conflicting evidence regarding phyllosilicates. Two main interpretations of this evidence have been proposed: Weathering of basaltic glasses by H2O and CO2 formed a mixture of oxides, salts, and metastable phyllosilicates such as montmorillonite and 'palagonite' formed when basaltic melt contacted ground ice or water. Palagonite is a hydrated basaltic glass containing dispersed ferric oxide, recrystallized in varying degrees to phyllosilicates. Typically it is aphanitic, although some examples contain phenocrysts. In either case, eolian redistribution is thought to have resulted in the material's global homogenization. Imaging spectroscopic data returned by the ISM instrument on Phobos 2 provide a powerful

  20. Coming to terms with lightness and brightness: effects of stimulus configuration and instructions on brightness and lightness judgments.

    PubMed

    Blakeslee, Barbara; Reetz, Daniel; McCourt, Mark E

    2008-08-06

    To recover surface reflectance and illuminance from the raw luminance signal, the visual system must use prior assumptions and strategies that make use of additional sources of information. Indeed, it has been found that depending on experimental conditions, lightness (apparent reflectance) may refer to judgments that are similar to brightness judgments (apparent luminance), that are similar to local brightness-contrast judgments, or that represent an independent third dimension of achromatic experience which exists only when the illumination across regions of the display is visibly non-uniform (L. E. Arend & B. Spehar, 1993a, 1993b). This means that lightness data generated in one experimental condition may not be comparable to lightness data measured in other conditions. We investigate this problem with regard to a history of data on simultaneous brightness-contrast by measuring brightness, brightness-contrast, and lightness in stimuli similar to those used in Gilchrist's edge-substitution studies (A. Gilchrist, S. Delman, & A. Jacobsen, 1983) and in stimuli similar to those used to test Gilchrist's intrinsic-image model against his newer anchoring model (A. Gilchrist, 2006). Our results clarify confusions that appear to stem from comparing different types of lightness judgments and from inadvertently using brightness as an index of lightness under conditions where independent lightness judgments are possible.

  1. Traditional Chinese Biotechnology

    NASA Astrophysics Data System (ADS)

    Xu, Yan; Wang, Dong; Fan, Wen Lai; Mu, Xiao Qing; Chen, Jian

    The earliest industrial biotechnology originated in ancient China and developed into a vibrant industry in traditional Chinese liquor, rice wine, soy sauce, and vinegar. It is now a significant component of the Chinese economy valued annually at about 150 billion RMB. Although the production methods had existed and remained basically unchanged for centuries, modern developments in biotechnology and related fields in the last decades have greatly impacted on these industries and led to numerous technological innovations. In this chapter, the main biochemical processes and related technological innovations in traditional Chinese biotechnology are illustrated with recent advances in functional microbiology, microbial ecology, solid-state fermentation, enzymology, chemistry of impact flavor compounds, and improvements made to relevant traditional industrial facilities. Recent biotechnological advances in making Chinese liquor, rice wine, soy sauce, and vinegar are reviewed.

  2. Traditional Chinese biotechnology.

    PubMed

    Xu, Yan; Wang, Dong; Fan, Wen Lai; Mu, Xiao Qing; Chen, Jian

    2010-01-01

    The earliest industrial biotechnology originated in ancient China and developed into a vibrant industry in traditional Chinese liquor, rice wine, soy sauce, and vinegar. It is now a significant component of the Chinese economy valued annually at about 150 billion RMB. Although the production methods had existed and remained basically unchanged for centuries, modern developments in biotechnology and related fields in the last decades have greatly impacted on these industries and led to numerous technological innovations. In this chapter, the main biochemical processes and related technological innovations in traditional Chinese biotechnology are illustrated with recent advances in functional microbiology, microbial ecology, solid-state fermentation, enzymology, chemistry of impact flavor compounds, and improvements made to relevant traditional industrial facilities. Recent biotechnological advances in making Chinese liquor, rice wine, soy sauce, and vinegar are reviewed.

  3. A bright attosecond x-ray pulse train generation in a double-laser-driven cone target

    NASA Astrophysics Data System (ADS)

    Hu, Li-Xiang; Yu, Tong-Pu; Shao, Fu-Qiu; Luo, Wen; Yin, Yan

    2016-06-01

    By using full three-dimensional particle-in-cell and Monte Carlo simulations, we investigate the generation of a high-brightness attosecond x-ray pulse train in a double-laser-driven cone target. The scheme makes use of two lasers: the first high-intensity laser with a laser peak intensity 1.37 × 1020 W/cm2 irradiates the cone and produces overdense attosecond electron bunches; the second counterpropagating weakly relativistic laser with a laser peak intensity 4.932 × 1017 W/cm2 interacts with the produced electron bunches and a bright x-ray pulse train is generated by Thomson backscattering of the second laser off the attosecond electron bunches. It is shown that the photon flux rises by 5 times using the cone target as compared with a normal channel. Meanwhile, the x-ray peak brightness increases significantly from 1.4 × 1021/(s mm2 mrad2 0.1 keV) to 6.0 × 1021/(s mm2 mrad2 0.1 keV), which is much higher than that of the Thomson x-ray source generated from traditional accelerators. We also discuss the influence of the laser and target parameters on the x-ray pulse properties. This compact bright x-ray source may have diverse applications, e.g., the study of electric dynamics and harmonics emission in the atomic scale.

  4. Perinatal Practices & Traditions Among Asian Indian Women.

    PubMed

    Goyal, Deepika

    2016-01-01

    As the population in the United States grows more diverse, nurses caring for childbearing women must be aware of the many cultural traditions and customs unique to their patients. This knowledge and insight supports women and their families with the appropriate care, information, and resources. A supportive relationship builds trust, offers guidance, and allows for the new family to integrate information from nurses and other healthcare providers with the practice of certain perinatal cultural traditions. The Asian Indian culture is rich in tradition, specifically during the perinatal period. To support the cultural beliefs and practices of Asian Indian women during this time, nurses need to be aware of and consider multiple factors. Many women are navigating the new role of motherhood while making sense of and incorporating important cultural rituals. The purpose of this article is to provide an overview of perinatal cultural practices and traditions specific to the Asian Indian culture that perinatal nurses may observe in the clinical setting. Cultural traditions and practices specific to the pregnancy and postpartum period are described together with symbolism and implications for nursing practice. It is important to note that information regarding perinatal customs is provided in an effort to promote culturally sensitive nursing care and may not pertain to all Asian Indian women living in the United States.

  5. Family traditions and generations.

    PubMed

    Schneiderman, Gerald; Barrera, Maru

    2009-01-01

    Currently, traditional family values that have been passed down through generations appear to be at risk. This has significant implications for the stability and health of individuals, families, and communities. This article explores selected issues related to intergenerational transmission of family values and cultural beliefs, with particular reference to Western culture and values that are rooted in Jewish and Christian traditions. It also examines family values and parenting styles as they influence the developing perspective of children and the family's adaptation to a changing world.

  6. IRAS variables as galactic structure tracers - Classification of the bright variables

    NASA Technical Reports Server (NTRS)

    Allen, L. E.; Kleinmann, S. G.; Weinberg, M. D.

    1993-01-01

    The characteristics of the 'bright infrared variables' (BIRVs), a sample consisting of the 300 brightest stars in the IRAS Point Source Catalog with IRAS variability index VAR of 98 or greater, are investigated with the purpose of establishing which of IRAS variables are AGB stars (e.g., oxygen-rich Miras and carbon stars, as was assumed by Weinberg (1992)). Results of the analysis of optical, infrared, and microwave spectroscopy of these stars indicate that, out of 88 stars in the BIRV sample identified with cataloged variables, 86 can be classified as Miras. Results of a similar analysis performed for a color-selected sample of stars, using the color limits employed by Habing (1988) to select AGB stars, showed that, out of 52 percent of classified stars, 38 percent are non-AGB stars, including H II regions, planetary nebulae, supergiants, and young stellar objects, indicating that studies using color-selected samples are subject to misinterpretation.

  7. CPD -20 1123 (Albus 1) Is a Bright He-B Subdwarf

    NASA Astrophysics Data System (ADS)

    Vennes, Stéphane; Kawka, Adéla; Smith, J. Allyn

    2007-10-01

    Based on photometric and astrometric data it has been proposed that Albus 1 (also known as CPD -20 1123) might be a hot white dwarf similar to G191-B2B or, alternatively, a hot subdwarf. We obtained a series of optical spectra showing that CPD -20 1123 is a bright He-B subdwarf. We analyzed the H I Balmer and He I line spectra and measured Teff = 19,800 +/- 400 K, logg=4.55+/-0.10, and logN(He)/N(H)=0.15+/-0.15. This peculiar object belongs to a family of evolved helium-rich stars that may be the products of double-degenerate mergers, or, alternatively, the products of post horizontal- or giant-branch evolution.

  8. [Preparation of reactive bright blue praseodymium dyestuff and its spectral properties].

    PubMed

    Liu, Xiao-Zhen; Yuan, Ya-Qin; Cai, Yu; Zhu, Xian; Wang, Yan-Hong

    2004-08-01

    Reactive bright blue praseodymium dyestuff was prepared by using reactive bright blue and praseodymium oxide. The spectra of reactive bright blue praseodymium and dyed silk cloth by reactive bright blue praseodymium dyestuff were studied by UV-Vis and IR spectra respectively. In the range of 200-800 nm, reactive bright blue has four absorption peaks, and lambda(max) is 259 nm; reactive bright blue praseodymium has three absorption peaks, while lambda(max), is 264.00 nm. In the range of 420-760 nm, reactive bright blue has two absorption peaks at 661.50 and 625.50 nm, respectively, and lambda(max) is 661.50 nm; reactive bright blue praseodymium has only one absorption peak at 618.00 nm. Coordinate bond links reactive bright blue to praseodymium ion. Reactive bright blue praseodymium increases linking radicals as compared with reactive bright blue.

  9. FORCAST Observations of a Bright ToO Comet

    NASA Astrophysics Data System (ADS)

    Wooden, Diane

    2013-10-01

    We propose to measure the dust and organics of a bright unknown comet or comet outburst with this CY2 Target-of-Opportunity (ToO) proposal. A 5-39 micron spectrum of a ToO bright comet with FORCAST will address our two primary goals: 1) characterize the coma dust mineralogy; and 2) identify organics in the critical 5-8 micron region. The crystalline fraction of comet dust has become a benchmark for models of heating and radial transport in our protoplanetary disk. In addition, by measuring the wavelengths, relative intensities, and feature asymmetries of crystalline peaks at 11.2, 19, 23.5, 27.5, and 33 micron, the shapes of forsterite crystals can be constrained and their condensation temperatures inferred by comparison with theoretical and experimental data. Observations of cometary organics probe the unknown precursor materials that were transformed by heat into 'macromolecular carbon' found ubiquitously in carbonaceous chondrite samples from primitive asteroids. Thermal models fitted to FORCAST observations of a bright ToO comet determine the dust properties and the comet's dust properties links to the physical and chemical conditions in the solar nebula, and help to fulfill the SOFIA Science Case for Evolution of Our Solar System. We define a CY2 ToO bright comet as an unpredictable cometary outburst event or a comet discovered after the CY2 submission deadline that produces a naked-eye comet that is observable within CY2. From 1995 through 2013, there are eight bright comet apparitions where five out of eight are ToO comets. For CY1, the likelihood was low for a ToO bright comet but comet ISON was discovered and activated. FORCAST 5-39 micron observations of a bright comet will enable the study of dust mineral compositions and organic materials, will enable the search for controversial species including PAHs, phyllosilicates and carbonates, and will add to 17 comets with known silicate crystalline fractions.

  10. Brightness of synchrotron radiation from undulators and bending magnets.

    PubMed

    Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

    2015-03-01

    The maximum of the Wigner distribution (WD) of synchrotron radiation (SR) fields is considered as a possible definition of SR source brightness. Such a figure of merit was originally introduced in the SR community by Kim [(1986), Nucl. Instrum. Methods Phys. Res. A, 246, 71-76]. The brightness defined in this way is always positive and, in the geometrical optics limit, can be interpreted as the maximum density of photon flux in phase space. For undulator and bending magnet radiation from a single electron, the WD function can be explicitly calculated. In the case of an electron beam with a finite emittance the brightness is given by the maximum of the convolution of a single electron WD function and the probability distribution of the electrons in phase space. In the particular case when both electron beam size and electron beam divergence dominate over the diffraction size and the diffraction angle, one can use a geometrical optics approach. However, there are intermediate regimes when only the electron beam size or the electron beam divergence dominate. In these asymptotic cases the geometrical optics approach is still applicable, and the brightness definition used here yields back once more to the maximum photon flux density in phase space. In these intermediate regimes a significant numerical disagreement is found between exact calculations and the approximation for undulator brightness currently used in the literature. The WD formalism is extended to a satisfactory theory for the brightness of a bending magnet. It is found that in the intermediate regimes the usually accepted approximation for bending magnet brightness turns out to be inconsistent even parametrically.

  11. Tradition in Science

    ERIC Educational Resources Information Center

    Heisenberg, Werner

    1973-01-01

    Discusses the influence of tradition in science on selection of scientific problems and methods and on the use of concepts as tools for research work. Indicates that future research studies will be directed toward the change of fundamental concepts in such fields as astrophysics, molecular biology, and environmental science. (CC)

  12. Reinventing the Rhetorical Tradition.

    ERIC Educational Resources Information Center

    Freedman, Aviva, Ed.; Pringle, Ian, Ed.

    The 19 conference papers in this collection deal with the relationship of various rhetorical theories and their practical applications to the rhetorical traditions that they are superseding. The papers deal with many topics, including the following: (1) a multidisciplinary approach to writing instruction; (2) the importance of writing as a human…

  13. In Defense of Tradition.

    ERIC Educational Resources Information Center

    Pekich, John

    A disturbing trend is developing in higher education which may jeopardize the quality and importance of the classical tradition in education. This trend is exemplified by demands that the liberal arts be made relevant and comprehensible to the student and that they be related in some way to the search for a good job. The great classical…

  14. Literacy in Traditional Societies.

    ERIC Educational Resources Information Center

    Goody, Jack, Ed.

    This series of essays derives from an interest in communications, in media and their effect upon human intercourse. Primarily, this concern with the technology of the intellect centers upon the effect of literacy on human culture, especially in 'traditional' or pre-industrial societies. In most of the essays, the effects of literacy are considered…

  15. Traditional Cherokee Food.

    ERIC Educational Resources Information Center

    Hendrix, Janey B.

    A collection for children and teachers of traditional Cherokee recipes emphasizes the art, rather than the science, of cooking. The hand-printed, illustrated format is designed to communicate the feeling of Cherokee history and culture and to encourage readers to collect and add family recipes. The cookbook could be used as a starting point for…

  16. Traditional Cherokee Food.

    ERIC Educational Resources Information Center

    Hendrix, Janey B.

    A collection for children and teachers of traditional Cherokee recipes emphasizes the art, rather than the science, of cooking. The hand-printed, illustrated format is designed to communicate the feeling of Cherokee history and culture and to encourage readers to collect and add family recipes. The cookbook could be used as a starting point for…

  17. Tradition in Science

    ERIC Educational Resources Information Center

    Heisenberg, Werner

    1973-01-01

    Discusses the influence of tradition in science on selection of scientific problems and methods and on the use of concepts as tools for research work. Indicates that future research studies will be directed toward the change of fundamental concepts in such fields as astrophysics, molecular biology, and environmental science. (CC)

  18. Musical Traditions. Puzzle Corner.

    ERIC Educational Resources Information Center

    Andrews, Ian A.

    1999-01-01

    Discusses the changes in musical experiences, such as live versus recorded music, as society has developed technologically. Presents a crossword puzzle that focuses on the traditions and musicians of baroque, classical, and romantic music each originating in Europe. Includes the clues and word list. (CMK)

  19. Non-Traditional Wraps

    ERIC Educational Resources Information Center

    Owens, Buffy

    2009-01-01

    This article presents a recipe for non-traditional wraps. In this article, the author describes how adults and children can help with the recipe and the skills involved with this recipe. The bigger role that children can play in the making of the item the more they are apt to try new things and appreciate the texture and taste.

  20. Modern vs. Traditional.

    ERIC Educational Resources Information Center

    Zhenhui, Rao

    1999-01-01

    This article discusses traditional methods, such as the grammar-translation, and modern methods, the communicative approach, for teaching English-as-a-foreign-language in China. The relationship between linguistic accuracy and communicative competence, student-centered orientation, and the role of the teacher are highlighted. (Author/VWL)

  1. Reinventing the Rhetorical Tradition.

    ERIC Educational Resources Information Center

    Freedman, Aviva, Ed.; Pringle, Ian, Ed.

    The 19 conference papers in this collection deal with the relationship of various rhetorical theories and their practical applications to the rhetorical traditions that they are superseding. The papers deal with many topics, including the following: (1) a multidisciplinary approach to writing instruction; (2) the importance of writing as a human…

  2. Traditional healers formalised?

    PubMed

    Van Niekerk, Jp

    2012-02-23

    Traditional healers are the first to be called for help when illness strikes the majority of South Africans. Their communities have faith in their ability to cure or alleviate conditions managed by doctors, and much more. A visit to such practitioners' websites (they are up with the latest advertising technology!) shows that they promise help with providing more power, love, security or money, protection from evil people and spirits, enhancing one's sex life with penis enlargement and vagina tightening spells, etc. Contemplating such claims, it is easy to be dismissive of traditional healers. But in this issue of the SAMJ Nompumelelo Mbatha and colleagues1 argue that the traditional healers' regulatory council, promised by an Act of Parliament, should be established, followed by (or preferably preceded by) formal recognition by employers of sick certificates issued by traditional healers. Can matters be so simply resolved? What does this mean for doctors and other formally recognised healthcare professionals, and how to respond to such claims and social pressures?

  3. Tradition and Change

    ERIC Educational Resources Information Center

    Nyre, Joseph E.

    2015-01-01

    Honors programs, like the institutions that host them, need to exercise constant re-examination to remain effective and to serve their students the best they can. As a private, liberal arts institution, in the tradition of the Irish Catholic Christian Brothers, Iona College provides many avenues to enhance student learning, and paramount to the…

  4. Challenging tradition in Nigeria.

    PubMed

    Supriya, K E

    1991-01-01

    In Nigeria since 1987, the National Association of Nigeria Nurses and Midwives (NSNNM) has used traditional medial and traditional health care workers to curtail the practice of female circumcision. Other harmful traditions are being changed also, such as early marriage, taboos of pregnancy and childbirth, and scarification. 30,000 member of NANNM are involved in this effort to halt the harmful practices themselves and to change community opinion. The program involved national and state level workshops on harmful health consequences of traditional practices and instruction on how to conduct focus group discussions to assess women's beliefs and practices. The focus groups were found to be a particularly successful method of opening up discussion of taboo topics and expressing deep emotions. The response to the knowledge that circumcision was not necessary was rage and anger, which was channeled into advocacy roles or change in the practice. The result was the channeled into advocacy roles for change in the practice. The result was the development of books, leaflets and videos. One community group designed a dress with a decorative motif of tatoos and bodily cuts to symbolize circumcision and scarring. Plays and songs were written and performed. Artists provided models of female genitalia both before and after circumcision. The campaign has been successful in bringing this issue to the public attention in prominent ways, such a national television, health talk shows, and women;s magazines. One of the most important results of the effort has been the demonstration that culture and tradition can be changed from within, rather than from outside imposition of values and beliefs.

  5. Night Sky Brightness at San Pedro Martir Observatory

    NASA Astrophysics Data System (ADS)

    Plauchu-Frayn, I.; Richer, M. G.; Colorado, E.; Herrera, J.; Córdova, A.; Ceseña, U.; Ávila, F.

    2017-03-01

    We present optical UBVRI zenith night sky brightness measurements collected on 18 nights during 2013 to 2016 and SQM measurements obtained daily over 20 months during 2014 to 2016 at the Observatorio Astronómico Nacional on the Sierra San Pedro Mártir (OAN-SPM) in México. The UBVRI data is based upon CCD images obtained with the 0.84 m and 2.12 m telescopes, while the SQM data is obtained with a high-sensitivity, low-cost photometer. The typical moonless night sky brightness at zenith averaged over the whole period is U = 22.68, B = 23.10, V = 21.84, R = 21.04, I = 19.36, and SQM = 21.88 {mag} {{arcsec}}-2, once corrected for zodiacal light. We find no seasonal variation of the night sky brightness measured with the SQM. The typical night sky brightness values found at OAN-SPM are similar to those reported for other astronomical dark sites at a similar phase of the solar cycle. We find a trend of decreasing night sky brightness with decreasing solar activity during period of the observations. This trend implies that the sky has become darker by Δ U = 0.7, Δ B = 0.5, Δ V = 0.3, Δ R=0.5 mag arcsec-2 since early 2014 due to the present solar cycle.

  6. PROFFIT: Analysis of X-ray surface-brightness profiles

    NASA Astrophysics Data System (ADS)

    Eckert, Dominique

    2016-08-01

    PROFFIT analyzes X-ray surface-brightness profiles for data from any X-ray instrument. It can extract surface-brightness profiles in circular or elliptical annuli, using constant or logarithmic bin size, from the image centroid, the surface-brightness peak, or any user-given center, and provides surface-brightness profiles in any circular or elliptical sectors. It offers background map support to extract background profiles, can excise areas using SAO DS9-compatible (ascl:0003.002) region files to exclude point sources, provides fitting with a number of built-in models, including the popular beta model, double beta, cusp beta, power law, and projected broken power law, uses chi-squared or C statistic, and can fit on the surface-brightness or counts data. It has a command-line interface similar to HEASOFT’s XSPEC (ascl:9910.005) package, provides interactive help with a description of all the commands, and results can be saved in FITS, ROOT or TXT format.

  7. Dark-bright soliton interactions beyond the integrable limit

    NASA Astrophysics Data System (ADS)

    Katsimiga, G. C.; Stockhofe, J.; Kevrekidis, P. G.; Schmelcher, P.

    2017-01-01

    In this work we present a systematic theoretical analysis regarding dark-bright solitons and their interactions, motivated by recent advances in atomic two-component repulsively interacting Bose-Einstein condensates. In particular, we study analytically via a two-soliton ansatz adopted within a variational formulation the interaction between two dark-bright solitons in a homogeneous environment beyond the integrable regime, by considering general inter- and intra-atomic interaction coefficients. We retrieve the possibility of a fixed point in the case where the bright solitons are out of phase. As the intercomponent interaction is increased, we also identify an exponential instability of the two-soliton state, associated with a subcritical pitchfork bifurcation. The latter gives rise to an asymmetric partition of the bright soliton mass and dynamically leads to spontaneous splitting of the bound pair. In the case of the in-phase bright solitons, we explain via parsing the analytical approximations and monitoring the direct dynamics why no such pair is identified, despite its prediction by the variational analysis.

  8. Sky brightness and twilight measurements at Jogyakarta city, Indonesia

    NASA Astrophysics Data System (ADS)

    Herdiwijaya, Dhani

    2016-11-01

    The sky brightness measurements were performed using a portable photometer. A pocket-sized and low-cost photometer has 20 degree area measurement, and spectral ranges between 320-720 nm with output directly in magnitudes per arc second square (mass) unit. The sky brightness with 3 seconds temporal resolutions was recorded at Jogyakarta city (110° 25’ E; 70° 52’ S; elevation 100 m) within 136 days in years from 2014 to 2016. The darkest night could reach 22.61 mpass only in several seconds, with mean value 18.8±0.7 mpass and temperature variation 23.1±1.2 C. The difference of mean sky brightness between before and after midnight was about -0.76 mpass or 2.0 times brighter. Moreover, the sky brightness and temperature fluctuations were more stable in after midnight than in before midnight. It is suggested that city light pollution affects those variations, and subsequently duration of twilight. By comparing twilight brightness for several places, we also suggest a 17° solar dip or about 66 minutes before sunrise for new time of Fajr prayer.

  9. Counting unstained, confluent cells by modified bright-field microscopy

    PubMed Central

    Drey, L. Louis; Graber, Michael C.; Bieschke, Jan

    2013-01-01

    We present a very simple procedure yielding high-contrast images of adherent, confluent cells such as human neuroblastoma (SH-EP) cells by ordinary bright-field microscopy. Cells are illuminated through a color filter and a pinhole aperture placed between the condenser and the cell culture surface. Refraction by each cell body generates a sharp, bright spot when the image is defocused. The technique allows robust, automatic cell counting from a single bright-field image in a wide range of focal positions; it does this via free, readily available image-analysis tools. Contrast may be enhanced by swelling cell bodies by brief incubation in PBS. The procedure was benchmarked against manual counting and automated counting of fluorescently labeled cell nuclei.. Counts from day-old and freshly seeded plates were compared in a range of densities, from sparse to densely overgrown. On average bright-field images produced the same counts as fluorescent images, with less than 5% error. This method will allow routine cell counting using a plain bright-field microscope, absent cell-line modification or cell staining. PMID:23834382

  10. Influence of spatial luminance interactions on perceived brightness

    NASA Astrophysics Data System (ADS)

    Eisemann, Ulrich

    2000-12-01

    Most color appearance models that have been published so far require a simplified description of the viewing field which is subdivided into a small number of homogeneous regions. The tristimulus values and luminance levels of these regions serve as input parameters for the models. The purpose of this paper however is to study brightness perception in a complex, achromatic surround using a more detailed description of the entire viewing field. Therefore, a number of psycho physical experiments were carried out using a CRT display on which relatively complex images were presented. Several observers were asked to judge the perceived brightness by adjusting the luminance level of a reference grey for a perfect brightness match. All thereby obtained psycho physical data were used to develop a new brightness appearance model that takes all objects in the entire visual field into account. The model includes an object feature extraction stage, in which object properties like area and position are extracted, a stage in which the characteristic object data are sorted into the appropriate classes of a histogram and a multivariate map in the form of a feedforward neural network to calculate the prediction of the perceived brightness.

  11. Bright and Not-So-Bright Prospects for Women in Physics in China-Beijing

    NASA Astrophysics Data System (ADS)

    Wu, Ling-An; Yang, Zhongqin; Ma, Wanyun

    2009-04-01

    Science in China-Beijing is enjoying a healthy increase in funding year by year, so the prospects for physicists are also bright. However, employment discrimination against women, formerly unthinkable, is becoming more and more explicit as the country evolves toward a market economy. Some recruitment notices bluntly state that only men will be considered, or impose restrictions upon potential female candidates. Female associate professors in many institutions are forced to retire at age 55, compared with 60 for men. This double-pinching discrimination against both younger and older women threatens to lead to a "pincer" effect, more serious than the "scissors" effect. Indeed, the ratio of senior-level women physicists in general has dropped significantly in recent years in China. Ironically, the number of female students applying for graduate studies is on the rise, as it is becoming increasingly difficult for them to compete with men in the job market with just an undergraduate degree. The Chinese Physical Society has made certain efforts to promote the image of women physicists, but it will take time and effort to reverse the trend.

  12. Lattice and emittance optimization techniques and the ALS brightness upgrade

    NASA Astrophysics Data System (ADS)

    Steier, C.; Madur, A.; Nishimura, H.; Robin, D.; Sannibale, F.; Sun, C.; Wan, W.; Yang, L.

    2011-09-01

    An upgrade project is under way to further improve the brightness of the Advanced Light Source at Berkeley Lab by reducing its horizontal emittance from 6.3 to 2.2 nm (effective emittance in the straights from 6.4 to 2.5 nm). This will result in a brightness increase by a factor of three for bend magnet beamlines and at least a factor of two for insertion device beamlines and will keep the ALS competitive with newer sources. This paper presents an overview of the upgrade project with emphasis on the nonlinear beam dynamics simulations. It also discusses in a more general way the techniques used at LBNL for finding optimum lattices (e.g. the ones with maximum brightness) and optimizing the particle dynamics, thereby increasing beam lifetime and stability.

  13. Bright Stuff on Ceres = Sulfates and Carbonates on CI Chondrites

    NASA Technical Reports Server (NTRS)

    Zolensky, Michael; Chan, Queenie H. S.; Gounelle, Matthieu; Fries, Marc

    2016-01-01

    Recent reports of the DAWN spacecraft's observations of the surface of Ceres indicate that there are bright areas, which can be explained by large amounts of the Mg sulfate hexahydrate (MgSO4•6(H2O)), although the identification appears tenuous. There are preliminary indications that water is being evolved from these bright areas, and some have inferred that these might be sites of contemporary hydro-volcanism. A heat source for such modern activity is not obvious, given the small size of Ceres, lack of any tidal forces from nearby giant planets, probable age and presumed bulk composition. We contend that observations of chondritic materials in the lab shed light on the nature of the bright spots on Ceres

  14. Bright and gap solitons in membrane-type acoustic metamaterials

    NASA Astrophysics Data System (ADS)

    Zhang, Jiangyi; Romero-García, Vicente; Theocharis, Georgios; Richoux, Olivier; Achilleos, Vassos; Frantzeskakis, Dimitrios J.

    2017-08-01

    We study analytically and numerically envelope solitons (bright and gap solitons) in a one-dimensional, nonlinear acoustic metamaterial, composed of an air-filled waveguide periodically loaded by clamped elastic plates. Based on the transmission line approach, we derive a nonlinear dynamical lattice model which, in the continuum approximation, leads to a nonlinear, dispersive, and dissipative wave equation. Applying the multiple scales perturbation method, we derive an effective lossy nonlinear Schrödinger equation and obtain analytical expressions for bright and gap solitons. We also perform direct numerical simulations to study the dissipation-induced dynamics of the bright and gap solitons. Numerical and analytical results, relying on the analytical approximations and perturbation theory for solions, are found to be in good agreement.

  15. Brightness of the Sky during a Solar Eclipse

    NASA Astrophysics Data System (ADS)

    Milisavljevic, D.; Nedeljkovic, S.; Miovic, V.

    2000-01-01

    Observations of the relative brightness of the sky were carried out in Horgos, Yugoslavia, and in Kamen Bryag, Bulgaria, during the total solar eclipse on August 11, 1999. The results were compared with observations of the partial solar eclipse of October 24, 1995, in Calcutta, India, and with some simple eclipse models based on the approximations for the limb darkening of the solar disc. The differences between the relative brightness of the sky during partial and during total solar eclipses are noticed, The measured brightness curve of the total eclipse rapidly declines immediately before, and it starts to grow rapidly immediately after the eclipse totality, while the curve of the partial eclipse has neither rapid declining nor growing.

  16. The ASAS-SN Bright Supernova Catalog - II. 2015

    NASA Astrophysics Data System (ADS)

    Holoien, T. W.-S.; Brown, J. S.; Stanek, K. Z.; Kochanek, C. S.; Shappee, B. J.; Prieto, J. L.; Dong, Subo; Brimacombe, J.; Bishop, D. W.; Basu, U.; Beacom, J. F.; Bersier, D.; Chen, Ping; Danilet, A. B.; Falco, E.; Godoy-Rivera, D.; Goss, N.; Pojmanski, G.; Simonian, G. V.; Skowron, D. M.; Thompson, Todd A.; Woźniak, P. R.; Ávila, C. G.; Bock, G.; Carballo, J.-L. G.; Conseil, E.; Contreras, C.; Cruz, I.; Andújar, J. M. F.; Guo, Zhen; Hsiao, E. Y.; Kiyota, S.; Koff, R. A.; Krannich, G.; Madore, B. F.; Marples, P.; Masi, G.; Morrell, N.; Monard, L. A. G.; Munoz-Mateos, J. C.; Nicholls, B.; Nicolas, J.; Wagner, R. M.; Wiethoff, W. S.

    2017-01-01

    This manuscript presents information for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) during 2015, its second full year of operations. The same information is presented for bright (mV ≤ 17), spectroscopically confirmed supernovae discovered by other sources in 2015. As with the first ASAS-SN bright supernova catalog, we also present redshifts and near-UV through IR magnitudes for all supernova host galaxies in both samples. Combined with our previous catalog, this work comprises a complete catalog of 455 supernovae from multiple professional and amateur sources, allowing for population studies that were previously impossible. This is the second of a series of yearly papers on bright supernovae and their hosts from the ASAS-SN team.

  17. Shiftwork in space - Bright light as a chronobiologic countermeasure

    NASA Technical Reports Server (NTRS)

    Gander, Philippa H.; Samel, Alexander

    1991-01-01

    The potential of timed exposures to bright light as a countermeasure to the changes in the work/rest schedules during space missions was investigated. In the experiments, four human subjects were exposed to two sessions of eleven days of simulated weightlessness (6-deg head-down-tilt bedrest) with 6-hr extensions of the scheduled wake time on days 3 and 4 (a 12-hr phase delay). In a blind crossover design, subjects were exposed to bright light (greater than 3500 lux) for 5 hrs on each of the two shift days and on the following day, at times expected to accelerate adaptation to the phase delay (experimental group), or have no phase shifting effect (control group). Results indicate that bright light may accelerate the rate of adaptation to work/rest schedule delays under simulated weightlessness conditions. However, such effect was found to be largely independent of the timing of the light exposure.

  18. Development of components for the high brightness laser

    NASA Astrophysics Data System (ADS)

    Garmire, E.

    1980-10-01

    In 1979 DBR lasers were fabricated and their properties studied. Further investigations were undertaken of the beam expander, to determine its potential for the high brightness laser. From this data it was determined that a design change for the high brightness laser is required. This design change is described. In addition, measurements were made on laser amplification to compare this method of achieving higher power compared to the coupled diode arrays. Finally, as a spin-off of this research, a new design for a single mode laser was discovered, using the active/passive laser, a configuration which was fabricated as a first step toward fabrication of DBR lasers. Each of these research efforts are described in this report. Monolithic integration of the necessary components on one substrate for the high brightness laser has been hindered by problems in material and fabrication uniformity. This will be described, and projections for future development will be outlined.

  19. The ASAS-SN bright supernova catalogue - II. 2015

    NASA Astrophysics Data System (ADS)

    Holoien, T. W.-S.; Brown, J. S.; Stanek, K. Z.; Kochanek, C. S.; Shappee, B. J.; Prieto, J. L.; Dong, Subo; Brimacombe, J.; Bishop, D. W.; Basu, U.; Beacom, J. F.; Bersier, D.; Chen, Ping; Danilet, A. B.; Falco, E.; Godoy-Rivera, D.; Goss, N.; Pojmanski, G.; Simonian, G. V.; Skowron, D. M.; Thompson, Todd A.; Woźniak, P. R.; Ávila, C. G.; Bock, G.; Carballo, J.-L. G.; Conseil, E.; Contreras, C.; Cruz, I.; Andújar, J. M. F.; Guo, Zhen; Hsiao, E. Y.; Kiyota, S.; Koff, R. A.; Krannich, G.; Madore, B. F.; Marples, P.; Masi, G.; Morrell, N.; Monard, L. A. G.; Munoz-Mateos, J. C.; Nicholls, B.; Nicolas, J.; Wagner, R. M.; Wiethoff, W. S.

    2017-05-01

    This manuscript presents information for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) during 2015, its second full year of operations. The same information is presented for bright (mV ≤ 17), spectroscopically confirmed supernovae discovered by other sources in 2015. As with the first ASAS-SN bright supernova catalogue, we also present redshifts and near-ultraviolet through infrared magnitudes for all supernova host galaxies in both samples. Combined with our previous catalogue, this work comprises a complete catalogue of 455 supernovae from multiple professional and amateur sources, allowing for population studies that were previously impossible. This is the second of a series of yearly papers on bright supernovae and their hosts from the ASAS-SN team.

  20. Intensity oscillations in chromospheric bright points and network elements

    NASA Astrophysics Data System (ADS)

    Kariyappa, R.

    1994-09-01

    From a 35-min time series of photographic spectra in the Ca II H-line obtained at the Vacuum Tower Telescope (VTT) of the Sacramento Peak Observatory under high spatial, spectral, and temporal resolution, we have derived a large number of H-line profiles at the sites of the bright points in the interior of the supergranulation cells, and at the network elements, on a quiet region at the center of the solar disc. It is shown that the bright points are associated with 3-min periodicity in their intensity oscillations whereas the network elements exhibit approximately 7-min periodicity. It is surmised that the large difference in periods of the intensity oscillations, the strength of the magnetic fields, and the intensity enhancements at the sites of the bright points and the network elements themselves may probably be taken as evidence to argue that the mechanisms of heating in the two cases are dissimilar, irrespective of the sizes of these structures.

  1. Cell structure imaging with bright and homogeneous nanometric light source.

    PubMed

    Fukuta, Masahiro; Ono, Atsushi; Nawa, Yasunori; Inami, Wataru; Shen, Lin; Kawata, Yoshimasa; Terekawa, Susumu

    2017-04-01

    Label-free optical nano-imaging of dendritic structures and intracellular granules in biological cells is demonstrated using a bright and homogeneous nanometric light source. The optical nanometric light source is excited using a focused electron beam. A zinc oxide (ZnO) luminescent thin film was fabricated by atomic layer deposition (ALD) to produce the nanoscale light source. The ZnO film formed by ALD emitted the bright, homogeneous light, unlike that deposited by another method. The dendritic structures of label-free macrophage receptor with collagenous structure-expressing CHO cells were clearly visualized below the diffraction limit. The inner fiber structure was observed with 120 nm spatial resolution. Because the bright homogeneous emission from the ZnO film suppresses the background noise, the signal-to-noise ratio (SNR) for the imaging results was greater than 10. The ALD method helps achieve an electron beam excitation assisted microscope with high spatial resolution and high SNR.

  2. On the relation between zenith sky brightness and horizontal illuminance

    NASA Astrophysics Data System (ADS)

    Kocifaj, M.; Posch, Th.; Solano Lamphar, H. A.

    2015-01-01

    The effects of artificial light at night are an emergent research topic for astronomers, physicists, engineers and biologists around the world. This leads to a need for measurements of the night sky brightness (= diffuse luminance of the night sky) and nocturnal illuminance. Currently, the most sensitive light meters measure the zenith sky brightness in magV/arcsec2 or - less frequently - in cd m-2. However, the horizontal illuminance resulting only from the night sky is an important source of information that is difficult to obtain with common instruments. Here we present a set of approximations to convert the zenith luminance into horizontal illuminance. Three different approximations are presented for three idealized atmospheric conditions: homogeneous sky brightness, an isotropically scattering atmosphere and a turbid atmosphere. We also apply the resulting conversion formulae to experimental data on night sky luminance, obtained during the past three years.

  3. The Metal-Rich Universe

    NASA Astrophysics Data System (ADS)

    Israelian, Garik; Meynet, Georges

    2012-10-01

    Preface; Part I. Abundances in the Galaxy: Field Stars: 1. Metal-rich stars and stellar populations: A brief history and new results; 2. The metal-rich nature of stars with planets; 3. Solar chemical peculiarities; 4. Kinematics of metal-rich stars with and without planets; 5. Elemental abundance trends in the metal-rich thin and thick disks; 6. Metal-rich massive stars - how metal-rich are they?; 7. Hercules stream stars and the metal-rich thick disk; 8. Abundance survey of the galactic thick disk; Part II. Abundances in the Galaxy: Galactic Stars in Clusters, Bulges and Centre: 9. Galactic open clusters with super solar metallicities; 10. Old and very metal-rich open clusters in the BOCCE project; 11. Massive stars vs. nebular abundances in the Orion nebula; 12. Abundance surveys of metal-rich bulge stars; 13. Metal abundances in the galactic center; 14. Light elements in the galactic bulge; 15. Metallicity and ages of selected G-K giants; Part III. Observations - Abundances in Extragalactic Contexts: 16. Stellar abundances of early-type galaxies and galactic spheroids: Evidence for metal-rich stars; 17. Measuring chemical abundances in extragalactic metal-rich HII regions; 18. On the maximum oxygen abundance in metal-rich spiral galaxies; 19. Starbursts and their contribution to metal enrichment; 20. High metallicities at high redshifts; 21. Evolution of dust and elemental abundances in quasar DLAs and GRB afterglows as a function of cosmic time; 22. Dust, metals and diffuse interstellar bands in damped Lyman Alpha systems; 23. Tracing metallicities in the Universe with the James Webb Space Telescope; Part IV. Stellar Populations and Mass Functions: 24. The stellar initial mass function of metal-rich populations; 25. IMF effects on the metallicity and colour evolution of disk galaxies; 26. The metallicity of circumnuclear star forming regions; 27. The stellar population of bulges; 28. The metallicity distribution of the stars in elliptical galaxies; 29. Wolf

  4. Hematite-Rich Deposits in Capri Chasma

    NASA Image and Video Library

    2016-12-14

    Capri Chasma is located in the eastern portion of the Valles Marineris canyon system, the largest known canyon system in the Solar System. Deeply incised canyons such as this are excellent targets for studying the Martian crust, as the walls may reveal many distinct types of bedrock. This section of the canyon was targeted by HiRISE based on a previous spectral detection of hematite-rich deposits in the area. Hematite, a common iron-oxide mineral, was first identified here by the Mars Global Surveyor Thermal Emission Spectrometer (TES). In this TES image, red pixels indicate higher abundances of hematite, while the blue and green pixels represent different types of volcanic rocks (e.g., basalt). Hematite in the Meridiani Planum region was also detected with the TES instrument (which we can see with the bright red spot on the Global TES mineral map). As a consequence, Meridiani Planum was the first landing site selected on Mars due to the spectral detection of a mineral that may have formed in the presence of liquid water. Shortly after landing, the Opportunity rover detected the presence of hematite in the form of concretions called "blueberries." The blueberries are found in association with layers of sulfate salt-rich rocks. The salts are hypothesized to have formed through the raising and lowering of the groundwater table. During one such an event, the rock altered to form the hematite-rich blueberries. As the rock was eroded away, the more resistant hematite-rich blueberries were plucked out and concentrated on the plains as a "lag" deposit. Martian blueberries are observed to be scattered across the plains of Meridiani along Opportunity's traverse from Eagle Crater to Endeavor Crater, where Opportunity continues to explore after its mission began over 10 years ago. This infrared-color image close-up highlights what is possibly the hematite-rich deposits nestled between different types of bedrock terraces in Capri Chasma. The bluish terrace is likely volcanic

  5. The possible origin of facular brightness in the solar atmosphere

    NASA Astrophysics Data System (ADS)

    Kostik, R.; Khomenko, E.

    2016-05-01

    This paper studies the dependence of the Ca ii H line core brightness on the strength and inclination of the photospheric magnetic field, and on the parameters of convective and wave motions in a facular region at the center of the solar disc. We use three simultaneous data sets that were obtained at the German Vacuum Tower Telescope (Observatorio del Teide, Tenerife): (1) spectra of Ba ii 4554 Å line, registered with the instrument TESOS to measure the variations of intensity and velocity through the photosphere up to the temperature minimum; (2) spectropolarimetric data in Fe i 1.56 μm lines (registered with the instrument TIP II) to measure photospheric magnetic fields; (3) filtergrams in Ca ii H that give information about brightness fluctuations in the chromosphere. The results show that the Ca ii H brightness in the facula strongly depends on the power of waves with periods in the 5-min range, which propagate upwards, and also on the phase shift between velocity oscillations at the bottom photosphere and around the temperature minimum height that is measured from Ba ii line. The Ca ii H brightness is maximum at locations where the phase shift between temperature and velocity oscillations lies within 0°-100°. There is an indirect influence of convective motions on the Ca ii H brightness. The higher the amplitude of convective velocities is and the greater the height is where they change their direction of motion, the brighter the facula. In summary, our results lead to conclusions that facular regions appear bright not only because of the Wilson depression in magnetic structures, but also owing to real heating.

  6. Brightness discrimination in the South African fur seal (Arctocephalus pusillus).

    PubMed

    Scholtyssek, C; Dehnhardt, G

    2013-05-24

    Underwater, the contrast between object and background is much larger reduced with increasing distance between object and observer than in air. For marine predators, such as pinnipeds, it would therefore be advantageous to possess a high sensitivity for brightness differences, since this would increase the distance at which prey can be detected visually. Few studies have examined the brightness discrimination thresholds of pinnipeds. Two studies with phocid seals have confirmed low brightness discrimination thresholds in pinnipeds whereas the threshold obtained for the South African fur seal seems to be twice as high as that of the phocids. However, the experiments with the South African fur seal have been conducted under inadequate conditions which likely resulted in an underestimation of the brightness discrimination ability of this species. The study at hand reinvestigated the brightness discrimination threshold of the South African fur seal under well controlled conditions. In a two alternative forced choice task, one fur seal was trained to indicate the position of the brighter of two gray discs presented on a black background on a monitor. The thresholds were determined for 11 standard intensities each tested against 8 lower comparison intensities. It was found that the fur seal was able to perceive brightness differences of 8-10%, which is better than the phocid species tested so far. For low standard intensities, however, the threshold increased which could to be due to a relative slow dark adaptation rate of the fur seal. The results are discussed in terms of the relevance of visual information for pinnipeds during foraging dives and are directly compared to the results obtained for the harbor seal which has been tested under the same conditions as the fur seal in a previous study.

  7. Life-threatening motor vehicle crashes in bright sunlight.

    PubMed

    Redelmeier, Donald A; Raza, Sheharyar

    2017-01-01

    Bright sunlight may create visual illusions that lead to driver error, including fallible distance judgment from aerial perspective. We tested whether the risk of a life-threatening motor vehicle crash was increased when driving in bright sunlight.This longitudinal, case-only, paired-comparison analysis evaluated patients hospitalized because of a motor vehicle crash between January 1, 1995 and December 31, 2014. The relative risk of a crash associated with bright sunlight was estimated by evaluating the prevailing weather at the time and place of the crash compared with the weather at the same hour and location on control days a week earlier and a week later.The majority of patients (n = 6962) were injured during daylight hours and bright sunlight was the most common weather condition at the time and place of the crash. The risk of a life-threatening crash was 16% higher during bright sunlight than normal weather (95% confidence interval: 9-24, P < 0.001). The increased risk was accentuated in the early afternoon, disappeared at night, extended to patients with different characteristics, involved crashes with diverse features, not apparent with cloudy weather, and contributed to about 5000 additional patient-days in hospital. The increased risk extended to patients with high crash severity as indicated by ambulance involvement, surgical procedures, length of hospital stay, intensive care unit admission, and patient mortality. The increased risk was not easily attributed to differences in alcohol consumption, driving distances, or anomalies of adverse weather.Bright sunlight is associated with an increased risk of a life-threatening motor vehicle crash. An awareness of this risk might inform driver education, trauma staffing, and safety warnings to prevent a life-threatening motor vehicle crash.

  8. Life-threatening motor vehicle crashes in bright sunlight

    PubMed Central

    Redelmeier, Donald A.; Raza, Sheharyar

    2017-01-01

    Abstract Bright sunlight may create visual illusions that lead to driver error, including fallible distance judgment from aerial perspective. We tested whether the risk of a life-threatening motor vehicle crash was increased when driving in bright sunlight. This longitudinal, case-only, paired-comparison analysis evaluated patients hospitalized because of a motor vehicle crash between January 1, 1995 and December 31, 2014. The relative risk of a crash associated with bright sunlight was estimated by evaluating the prevailing weather at the time and place of the crash compared with the weather at the same hour and location on control days a week earlier and a week later. The majority of patients (n = 6962) were injured during daylight hours and bright sunlight was the most common weather condition at the time and place of the crash. The risk of a life-threatening crash was 16% higher during bright sunlight than normal weather (95% confidence interval: 9–24, P < 0.001). The increased risk was accentuated in the early afternoon, disappeared at night, extended to patients with different characteristics, involved crashes with diverse features, not apparent with cloudy weather, and contributed to about 5000 additional patient-days in hospital. The increased risk extended to patients with high crash severity as indicated by ambulance involvement, surgical procedures, length of hospital stay, intensive care unit admission, and patient mortality. The increased risk was not easily attributed to differences in alcohol consumption, driving distances, or anomalies of adverse weather. Bright sunlight is associated with an increased risk of a life-threatening motor vehicle crash. An awareness of this risk might inform driver education, trauma staffing, and safety warnings to prevent a life-threatening motor vehicle crash. Level of evidence: Epidemiologic Study, level III. PMID:28072708

  9. Bright and dark excitons in semiconductor carbon nanotubes

    SciTech Connect

    Tretiak, Sergei

    2008-01-01

    We report electronic structure calculations of finite-length semiconducting carbon nanotubes using the time dependent density functional theory (TD-DFT) and the time dependent Hartree Fock (TD-HF) approach coupled with semiempirical AM1 and ZINDO Hamiltonians. We specifically focus on the energy splitting, relative ordering, and localization properties of the optically active (bright) and optically forbidden (dark) states from the lowest excitonic band of the nanotubes. These excitonic states are very important in competing radiative and non-radiative processes in these systems. Our analysis of excitonic transition density matrices demonstrates that pure DFT functionals overdelocalize excitons making an electron-hole pair unbound; consequently, excitonic features are not presented in this method. In contrast, the pure HF and A111 calculations overbind excitons inaccurately predicting the lowest energy state as a bright exciton. Changing AM1 with ZINDO Hamiltonian in TD-HF calculations, predicts the bright exciton as the second state after the dark one. However, in contrast to AM1 calculations, the diameter dependence of the excitation energies obtained by ZINDO does not follow the experimental trends. Finally, the TD-DFT approach incorporating hybrid functions with a moderate portion of the long-range HF exchange, such as B3LYP, has the most generality and predictive capacity providing a sufficiently accurate description of excitonic structure in finite-size nanotubes. These methods characterize four important lower exciton bands. The lowest state is dark, the upper band is bright, and the two other dark and nearly degenerate excitons lie in-between. Although the calculated energy splittings between the lowest dark and the bright excitons are relatively large ({approx}0.1 eV), the dense excitonic manifold below the bright exciton allows for fast non-radiative relaxation leasing to the fast population of the lowest dark exciton. This rationalizes the low

  10. Effects of bright light treatment on psychomotor speed in athletes

    PubMed Central

    Tulppo, Mikko P.; Jurvelin, Heidi; Roivainen, Eka; Nissilä, Juuso; Hautala, Arto J.; Kiviniemi, Antti M.; Kiviniemi, Vesa J.; Takala, Timo

    2014-01-01

    Purpose: A recent study suggests that transcranial brain targeted light treatment via ear canals may have physiological effects on brain function studied by functional magnetic resonance imaging (fMRI) techniques in humans. We tested the hypothesis that bright light treatment could improve psychomotor speed in professional ice hockey players. Methods: Psychomotor speed tests with audio and visual warning signals were administered to a Finnish National Ice Hockey League team before and after 24 days of transcranial bright light or sham treatment. The treatments were given during seasonal darkness in the Oulu region (latitude 65 degrees north) when the strain on the players was also very high (10 matches during 24 days). A daily 12-min dose of bright light or sham (n = 11 for both) treatment was given every morning between 8 and 12 am at home with a transcranial bright light device. Mean reaction time and motor time were analyzed separately for both psychomotor tests. Analysis of variance for repeated measures adjusted for age was performed. Results: Time × group interaction for motor time with a visual warning signal was p = 0.024 after adjustment for age. In Bonferroni post-hoc analysis, motor time with a visual warning signal decreased in the bright light treatment group from 127 ± 43 to 94 ± 26 ms (p = 0.024) but did not change significantly in the sham group 121 ± 23 vs. 110 ± 32 ms (p = 0.308). Reaction time with a visual signal did not change in either group. Reaction or motor time with an audio warning signal did not change in either the treatment or sham group. Conclusion: Psychomotor speed, particularly motor time with a visual warning signal, improves after transcranial bright light treatment in professional ice-hockey players during the competition season in the dark time of the year. PMID:24860513

  11. Traditional Chinese drug therapy.

    PubMed

    Borchardt, John K

    2003-12-01

    More than 4,000 years old, traditional Chinese medicine continues to be widely practiced in China and in western countries. Traditional Chinese medicine teaches that good health is the result of harmony and balance between five basic elements: earth, water, fire, wood and metal. Also important to health are the two types of energy Yin and Yang, constituting a vital substance that circulates through the body. Drug therapy has been one of the means used in Chinese medicine to keep these elements and the flow of energy in balance. Many of the same herbs used thousands of years ago in China could be the source of new pharmaceuticals in Western medicine. (c) 2003 Prous Science. All rights reserved.

  12. Traditional birth attendants.

    PubMed

    Leedam, E

    1985-09-01

    In many countries 60-80% of deliveries are assisted by traditional birth attendants (TBAs). Over the last several decades efforts have been made to regulate, upgrade through training or replace the TBA. The strength of the TBA stems from the fact that she is part of the cultural and social life of the community in which she lives. Her weakness lies in the traditional practices which may have dangers for her clients. With suitable training and supervision these dangers can be minimized and her potential used to improve the health of mothers and babies. Increasingly countries are recognizing that the TBA will represent a major resource where women do not have access to services for either cultural or geographic barriers. The effective use of this resource will require an understanding and appreciation of the TBA's role and contribution by all health authorities, flexibility in the development of training programs and the co-operation of the TBAs themselves.

  13. Expedition 18 Traditional Blessing

    NASA Image and Video Library

    2008-10-11

    American spaceflight participant Richard Garriott, left, Expedition 18 Flight Engineer Yuri V. Lonchakov and Expedition 18 Commander Michael Fincke, right, participate in the traditional blessing prior to the bus ride to building 254 where the crew don their spacesuits, Sunday, Oct. 12, 2008, in Baikonur, Kazakhstan. The Soyuz TMA-13 spacecraft launched from the Baikonur Cosmodrome in Kazakhstan carrying Fincke, Lonchakov and Garriott. Photo Credit: (NASA/Bill Ingalls)

  14. Laser ion source for high brightness heavy ion beam

    SciTech Connect

    Okamura, M.

    2016-09-01

    A laser ion source is known as a high current high charge state heavy ion source. But, we place great emphasis on the capability to realize a high brightness ion source. A laser ion source has a pinpoint small volume where materials are ionized and can achieve quite uniform low temperature ion beam. Those features may enable us to realize very small emittance beams. Furthermore, a low charge state high brightness laser ion source was successfully commissioned in Brookhaven National Laboratory in 2014. Now most of all the solid based heavy ions are being provided from the laser ion source for regular operation.

  15. High-brightness displays in integrated weapon sight systems

    NASA Astrophysics Data System (ADS)

    Edwards, Tim; Hogan, Tim

    2014-06-01

    In the past several years Kopin has demonstrated the ability to provide ultra-high brightness, low power display solutions in VGA, SVGA, SXGA and 2k x 2k display formats. This paper will review various approaches for integrating high brightness overlay displays with existing direct view rifle sights and augmenting their precision aiming and targeting capability. Examples of overlay display systems solutions will be presented and discussed. This paper will review significant capability enhancements that are possible when augmenting the real-world as seen through a rifle sight with other soldier system equipment including laser range finders, ballistic computers and sensor systems.

  16. Laser ion source for high brightness heavy ion beam

    DOE PAGES

    Okamura, M.

    2016-09-01

    A laser ion source is known as a high current high charge state heavy ion source. But, we place great emphasis on the capability to realize a high brightness ion source. A laser ion source has a pinpoint small volume where materials are ionized and can achieve quite uniform low temperature ion beam. Those features may enable us to realize very small emittance beams. Furthermore, a low charge state high brightness laser ion source was successfully commissioned in Brookhaven National Laboratory in 2014. Now most of all the solid based heavy ions are being provided from the laser ion sourcemore » for regular operation.« less

  17. A bright PPKTP waveguide source of polarization entangled photons

    SciTech Connect

    Fanto, Michael; Tison, Christoper C.; Holwand, Gregory A; Preble, Dr. Stefan F; Alsing, Paul; Smith IV, Amos M

    2015-01-01

    The need for bright efficient sources of entangled photons has been a subject of tremendous research over the last decade. Researchers have been working to increase the brightness and purity to help overcome the spontaneous nature of the sources. Periodic poling has been implemented to allow for the use of crystals that would not normally satisfy the phase matching conditions. Utilizing periodic poling and single mode waveguide confinement of the pump field has yielded extremely large effective nonlinearities in sources easily producing millions of photon pairs. Here we will demonstrate these large nonlinearity effects in a periodically poled potassium titanyl phosphate (PPKTP) waveguide as well as characterizing the source purity.

  18. A Complete Sample of Long Bright Swift GRBs

    NASA Astrophysics Data System (ADS)

    Tagliaferri, G.; Salvaterra, R.; Campana, S.; Covino, S.; D'Avanzo, P.; Fugazza, D.; Ghirlanda, G.; Ghisellini, G.; Melandri, A.; Sbarufatti, B.; Vergani, S.; Nava, L.

    2013-07-01

    Starting from the Swift sample we defined a complete sub-sample of 58 bright long Gamma Ray Bursts (GRB), 52 of them (90%) with a redshift determination, in order to characterize their properties. This complete sample of bright long- GRBs allowed us to investigate their evolution with cosmic time and properties. We focused in particular on the GRB luminosity function, on the spectral-energy correlations of their prompt emission, on the nature of dark bursts and on possible correlations between the prompt and the X-ray afterglow properties.

  19. Histogram Equalization with Variable Enhancement Degree for Preserving Mean Brightness

    NASA Astrophysics Data System (ADS)

    Kawakami, Takashi; Murahira, Kota; Taguchi, Akira

    The histogram equalization (HE) is one of the common methods used for improving contrast in digital images. However, this technique causes a fluctuation of mean brightness. The fluctuation leads to the flicker for video signal. In order to preserve the mean brightness, the dynamic histogram equalization (DHE) is proposed. In this letter, we propose a novel DHE which is called the DHE with variable enhancement degree (DHEwVED). This method can change from DHE to HE by turning one parameter. We also show the effectiveness of the proposed method.

  20. RXS J16437+3402: A New Bright Cataclysmic Variable

    NASA Astrophysics Data System (ADS)

    Mickaelian, A. M.; Balayan, S. K.; Ilovaisky, S.; Chevalier, C.; Veron-Cetty, M. P.; Veron, P.

    The Second part of the FBS was devoted to search and study of blue stellar objects. Optical identifications have been made for a number of ROSAT sources to find new QSO and Sy candidates. One of the objects, RXS J16437+3402, appeared to be a bright (m = 15.2) and very interesting cataclysmic variable: the Byurakan 2.6 m and OHP 1.93 m observations in 2000 show rapid variations of brightness, colour, and spectral lines. The object is possibly a low-inclination SW Sextantis star.

  1. Laser ion source for high brightness heavy ion beam

    SciTech Connect

    Okamura, M.

    2016-09-01

    A laser ion source is known as a high current high charge state heavy ion source. But, we place great emphasis on the capability to realize a high brightness ion source. A laser ion source has a pinpoint small volume where materials are ionized and can achieve quite uniform low temperature ion beam. Those features may enable us to realize very small emittance beams. Furthermore, a low charge state high brightness laser ion source was successfully commissioned in Brookhaven National Laboratory in 2014. Now most of all the solid based heavy ions are being provided from the laser ion source for regular operation.

  2. Laser ion source for high brightness heavy ion beam

    NASA Astrophysics Data System (ADS)

    Okamura, M.

    2016-09-01

    A laser ion source is known as a high current high charge state heavy ion source. However we place great emphasis on the capability to realize a high brightness ion source. A laser ion source has a pinpoint small volume where materials are ionized and can achieve quite uniform low temperature ion beam. Those features may enable us to realize very small emittance beams. In 2014, a low charge state high brightness laser ion source was successfully commissioned in Brookhaven National Laboratory. Now most of all the solid based heavy ions are being provided from the laser ion source for regular operation.

  3. Erratum - the Lowest Surface Brightness Disc Galaxy Known

    NASA Astrophysics Data System (ADS)

    Davies, J. I.; Phillipps, S.; Disney, M. J.

    1988-11-01

    The paper "The lowest surface brightness disc galaxy known' by J.I. Davies, S. Phillipps and M.J. Disney was published in Mon. Not. R. astr. Soc. (1988), 231, 69p. The declination of the object given in section 2 of the paper is incorrect and should be changed to +19^deg^48'23". Thus the object cannot be identified with GP 1444 as in the original paper. To minimize confusion we propose to refer to the low surface brightness galaxy as GP 1444A.

  4. Improved brightness on broad-area single emitter (BASE) modules

    NASA Astrophysics Data System (ADS)

    Pawlik, Susanne; Guarino, Andrea; Matuschek, Nicolai; Bättig, Rainer; Arlt, Sebastian; Lu, Denis; Zayer, Nadhum; Greatrex, Jeffery; Sverdlov, Boris; Valk, Bernd; Lichtenstein, Norbert

    2009-02-01

    In this communication we report on the approaches to increase the brightness of Bookham's latest generations of high power pump modules. Since the single-emitter laser diode is the essential building block in all module designs, the optimization of the device design towards higher wall-plug efficiency, higher brightness and better reliability is one focus of the ongoing development efforts at Bookham. By using an analytical simulation tool critical parameters for efficient emitter-fiber coupling as the beam divergence and coupling scheme could be identified.

  5. Adapting traditional healing practices.

    PubMed

    Weiser, J

    1999-01-01

    The Aboriginal people in Canada have been noted to have low self-esteem, subsequently increasing their risk of HIV. To this effect, two traditional healing practices are being used to help these people avoid HIV infection, and to live more healthily and positively if they are infected. The first method is the Medicine Wheel, which is a traditional model used to represent the complex interrelationship among all living things and show how their immune system is physically affected by their emotions and worries. Many Aboriginal AIDS Organizations, counselors and others are now using this AIDS teaching Wheel model. Meanwhile, the second method is the Sharing Circles, which provide an environment where people feel safe to talk about HIV and give participants a sense of support and a means for expression without stigma or judgement. As a result, many people who attend HIV circles begin to take better care of themselves and of others. Overall, it is emphasized that these traditional healing practices can be effectively adapted for use in HIV counseling and education.

  6. Talking Shape: Parental Language with Electronic versus Traditional Shape Sorters

    ERIC Educational Resources Information Center

    Zosh, Jennifer M.; Verdine, Brian N.; Filipowicz, Andrew; Golinkoff, Roberta Michnick; Hirsh-Pasek, Kathy; Newcombe, Nora S.

    2015-01-01

    As the traditional toys of the past are quickly being replaced with electronically "enhanced" toys, it is important to understand how these changes impact parent--child interactions, especially in light of the evidence that the richness and variety of these interactions have long-term effects on diverse areas of cognition (Hart &…

  7. Talking Shape: Parental Language with Electronic versus Traditional Shape Sorters

    ERIC Educational Resources Information Center

    Zosh, Jennifer M.; Verdine, Brian N.; Filipowicz, Andrew; Golinkoff, Roberta Michnick; Hirsh-Pasek, Kathy; Newcombe, Nora S.

    2015-01-01

    As the traditional toys of the past are quickly being replaced with electronically "enhanced" toys, it is important to understand how these changes impact parent--child interactions, especially in light of the evidence that the richness and variety of these interactions have long-term effects on diverse areas of cognition (Hart &…

  8. The Oral Tradition: Springboard for Teaching Black Literature.

    ERIC Educational Resources Information Center

    Wilson, Velez H.

    Black Americans have inherited a rich store of oral literature (folk music, folk tales, folk customs, and superstitions). When approached from the point of view of the students' experience, this oral tradition can be an effective springboard for discussion, reading, and writing in the classroom. Brass band funeral processions can be viewed as a…

  9. Sliding Mode Pulsed Averaging IC Drivers for High Brightness Light Emitting Diodes

    SciTech Connect

    Dr. Anatoly Shteynberg, PhD

    2006-08-17

    This project developed new Light Emitting Diode (LED) driver ICs associated with specific (uniquely operated) switching power supplies that optimize performance for High Brightness LEDs (HB-LEDs). The drivers utilize a digital control core with a newly developed nonlinear, hysteretic/sliding mode controller with mixed-signal processing. The drivers are flexible enough to allow both traditional microprocessor interface as well as other options such as “on the fly” adjustment of color and brightness. Some other unique features of the newly developed drivers include • AC Power Factor Correction; • High power efficiency; • Substantially fewer external components should be required, leading to substantial reduction of Bill of Materials (BOM). Thus, the LED drivers developed in this research : optimize LED performance by increasing power efficiency and power factor. Perhaps more remarkably, the LED drivers provide this improved performance at substantially reduced costs compared to the present LED power electronic driver circuits. Since one of the barriers to market penetration for HB-LEDs (in particular “white” light LEDs) is cost/lumen, this research makes important contributions in helping the advancement of SSL consumer acceptance and usage.

  10. Chemical abundances in low surface brightness galaxies: Implications for their evolution

    NASA Technical Reports Server (NTRS)

    Mcgaugh, S. S.; Bothun, G. D.

    1993-01-01

    Low Surface Brightness (LSB) galaxies are an important but often neglected part of the galaxy content of the universe. Their importance stems both from the selection effects which cause them to be under-represented in galaxy catalogs, and from what they can tell us about the physical processes of galaxy evolution that has resulted in something other than the traditional Hubble sequence of spirals. An important constraint for any evolutionary model is the present day chemical abundances of LSB disks. Towards this end, spectra for a sample of 75 H 2 regions distributed in 20 LSB disks galaxies were obtained. Structurally, this sample is defined as having B(0) fainter than 23.0 mag arcsec(sup -2) and scale lengths that cluster either around 3 kpc or 10 kpc. In fact, structurally, these galaxies are very similar to the high surface brightness spirals which define the Hubble sequence. Thus, our sample galaxies are not dwarf galaxies but instead have masses comparable to or in excess of the Milky Way. The basic results from these observations are summarized.

  11. Extremely Low Passive Microwave Brightness Temperatures Due to Thunderstorms

    NASA Technical Reports Server (NTRS)

    Cecil, Daniel J.

    2015-01-01

    Extreme events by their nature fall outside the bounds of routine experience. With imperfect or ambiguous measuring systems, it is appropriate to question whether an unusual measurement represents an extreme event or is the result of instrument errors or other sources of noise. About three weeks after the Tropical Rainfall Measuring Mission (TRMM) satellite began collecting data in Dec 1997, a thunderstorm was observed over northern Argentina with 85 GHz brightness temperatures below 50 K and 37 GHz brightness temperatures below 70 K (Zipser et al. 2006). These values are well below what had previously been observed from satellite sensors with lower resolution. The 37 GHz brightness temperatures are also well below those measured by TRMM for any other storm in the subsequent 16 years. Without corroborating evidence, it would be natural to suspect a problem with the instrument, or perhaps an irregularity with the platform during the first weeks of the satellite mission. Automated quality control flags or other procedures in retrieval algorithms could treat these measurements as errors, because they fall outside the expected bounds. But the TRMM satellite also carries a radar and a lightning sensor, both confirming the presence of an intense thunderstorm. The radar recorded 40+ dBZ reflectivity up to about 19 km altitude. More than 200 lightning flashes per minute were recorded. That same storm's 19 GHz brightness temperatures below 150 K would normally be interpreted as the result of a low-emissivity water surface (e.g., a lake, or flood waters) if not for the simultaneous measurements of such intense convection. This paper will examine records from TRMM and related satellite sensors including SSMI, AMSR-E, and the new GMI to find the strongest signatures resulting from thunderstorms, and distinguishing those from sources of noise. The lowest brightness temperatures resulting from thunderstorms as seen by TRMM have been in Argentina in November and December. For

  12. Long pulse compact and high-brightness near 1-kW QCW diode laser stack

    NASA Astrophysics Data System (ADS)

    Wilson, Stewart; Altshuler, Gregory; Erofeev, Andrey; Inochkin, Mikhail; Khloponin, Leonid; Khramov, Valery; Feldchtein, Felix

    2012-03-01

    A custom designed compact, high brightness diode laser array stack was designed and manufactured using proprietary methods that are robust and suitable for low cost manufacturing. The diode laser stack consisted of four 10 mm-wide diode laser bars having lasing wavelength of 970 - 980 nm mounted onto high performance submounts separated by approximately 1mm. Each diode laser bar had a 50% fill factor. The cooling methodology employed used a combined passive and active scheme and not the traditional more expensive and more complicated standard microchannel coolers used for high duty cycle applications. The total combined optical power attained from the diode array stack was close to 1 kW for current levels up to 220 A, limited only by the capability of the power supply. In this paper, we summarize the performance results for this diode laser array and analyze the maximum expected optical performance as a function of operating current and pulse width and junction temperature limit.

  13. Thermal neutron image intensifier tube provides brightly visible radiographic pattern

    NASA Technical Reports Server (NTRS)

    Berger, H.; Kraska, I.; Niklas, W.; Schmidt, A.

    1967-01-01

    Vacuum-type neutron image intensifier tube improves image detection in thermal neutron radiographic inspection. This system converts images to an electron image, and with electron acceleration and demagnification between the input target and output screen, produces a bright image viewed through a closed circuit television system.

  14. RESPONSES OF BRIGHT, NORMAL, AND RETARDED CHILDREN TO LEARNING TASKS.

    ERIC Educational Resources Information Center

    CARRIER, NEIL A.; AND OTHERS

    THE RELATIONSHIPS AMONG THE VARIABLES OF INTELLIGENCE, LEARNING TASK PERFORMANCE, EMOTIONAL TENSION, AND TASK MOTIVATION WERE STUDIED. ABOUT 120 BRIGHT, NORMAL, AND RETARDED CHILDREN PERFORMED SIX TRIALS OF NUMBER LEARNING, CONCEPT FORMATION, PROBLEM SOLVING, PERCEPTUAL-MOTOR COORDINATION, AND VERBAL LEARNING TASKS. DURING THE LEARNING SESSIONS,…

  15. High-brightness high-duty cycle electron injectors

    NASA Astrophysics Data System (ADS)

    Sannibale, Fernando

    2014-03-01

    High brightness electron sources have been one of the driving forces behind the spectacular results achieved in the last decade by accelerator-based applications. Indeed, X-Ray FELs, with their 10-fold orders of magnitude increase in peak brightness, probably represent the best example of it. New ambitious proposals for X-ray FELs and ERLs, as well as inverse Compton sources for X- or gamma-ray production, are now requiring operation at MHz-GHz repetition rates. In response to that, a number of groups around the world have been actively working in developing high-brightness high-duty cycle electron injectors capable of driving such machines. The high repetition rate requirement cannot be met by the existing low-repetition rate high-brightness injector schemes, and new technologies are under investigation. This paper includes a description of the requirements for such injectors, an overview of the pursued technologies and schemes, a description of the main beam dynamics issues associated with the different choices, and a number of examples of the results obtained so far by the groups active in the field.

  16. Brightness Rural Electrification Program: Renewable Energy in China

    SciTech Connect

    Not Available

    2004-04-01

    Fact sheet describes China's New Brightness Rural Electrification Program to provide electricity for 23 million people in remote areas of China using renewable energy such as wind energy and solar power (photovoltaics). Targets, results, and progress are described. Regions targeted are Inner Mongolia, Tibet, and Gansu.

  17. The "Brightness Rules" Alternative Conception for Light Bulb Circuits

    ERIC Educational Resources Information Center

    Bryan, Joel A.; Stuessy, Carol

    2006-01-01

    An alternative conception for the observed differences in light bulb brightness was revealed during an unguided inquiry investigation in which prospective elementary teachers placed identical bulbs in series, parallel, and combination direct current circuits. Classroom observations, document analyses, and video and audio transcriptions led to the…

  18. Bright Sneezes and Dark Coughs, Loud Sunlight and Soft Moonlight.

    ERIC Educational Resources Information Center

    Marks, Lawrence E.

    1982-01-01

    In a series of four experiments, subjects used scales of loudness, pitch, and brightness to evaluate the meanings of a variety of synesthetic metaphors--expressions in which words or phrases describing experiences proper to one sense modality transfer their meaning to another modality. (Author/PN)

  19. High brightness laser systems incorporating advanced laser bars

    NASA Astrophysics Data System (ADS)

    Strohmaier, Stephan; Vethake, Thilo; Gottdiener, Mark; Wunderlin, Jens; Negoita, Viorel; Li, Yufeng; Barnowski, Tobias; Gong, Tim; An, Haiyan; Treusch, Georg

    2013-02-01

    The performance of high power and high brightness systems has been developing and is developing fast. In the multi kW regime both very high spatial and spectral brightness systems are emerging. Also diode laser pumped and direct diode lasers are becoming the standard laser sources for many applications. The pump sources for thin Disk Laser systems at TRUMPF Photonics enabled by high power and efficiency laser bars are becoming a well established standard in the industry with over two thousand 8 kW Disk Laser pumps installed in TruDisk systems at the customer site. These systems have proven to be a robust and reliable industrial tool. A further increase in power and efficiency of the bar can be easily used to scale the TruDisk output power without major changes in the pump source design. This publication will highlight advanced laser systems in the multi kW range for both direct application and solid state laser pumping using specifically tailored diode laser bars for high spatial and/or high spectral brightness. Results using wavelength stabilization techniques suitable for high power CW laser system applications will be presented. These high power and high brightness diode laser systems, fiber coupled or in free space configuration, depending on application or customer need, typically operate in the range of 900 to 1070 nm wavelength.

  20. The 1997 Reference of Diffuse Night Sky Brightness

    NASA Technical Reports Server (NTRS)

    Leinert, C.; Bowyer, S.; Haikala, L. K.; Hanner, M. S.; Hauser, M. G.; Levasseur-Regourd, A. C.; Mann, I.; Mattila, K.; Reach, W. T.; Schlosser, W.; Staude, J. J.; Toller, G. N.; Weiland, J. L.; Weinberg, J. L.; Witt, A. N.

    1997-01-01

    In the following we present material in tabular and graphical form, with the aim to allow the non specialist to obtain a realistic estimate of the diffuse night sky brightness over a wide range of wavelengths from the far UV longward of Ly to the far-infrared.

  1. Aviation -- Where Career Opportunities are Bright, Counselor's Guide.

    ERIC Educational Resources Information Center

    Zaharevitz, Walter; Marshall, Jane N.

    This aviation occupations guide is designed for use as a unit as well as in conjunction with an aviation careers package of material that contains a film strip and recording. Chapter One contains the script of the film strip, Aviation--Where Career Opportunities are Bright, and includes all photographs used in the film strip plus numerous…

  2. Soil Moisture Active/Passive (SMAP) Forward Brightness Temperature Simulator

    NASA Technical Reports Server (NTRS)

    Peng, Jinzheng; Peipmeier, Jeffrey; Kim, Edward

    2012-01-01

    The SMAP is one of four first-tier missions recommended by the US National Research Council's Committee on Earth Science and Applications from Space (Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond, Space Studies Board, National Academies Press, 2007) [1]. It is to measure the global soil moisture and freeze/thaw from space. One of the spaceborne instruments is an L-band radiometer with a shared single feedhorn and parabolic mesh reflector. While the radiometer measures the emission over a footprint of interest, unwanted emissions are also received by the antenna through the antenna sidelobes from the cosmic background and other error sources such as the Sun, the Moon and the galaxy. Their effects need to be considered accurately, and the analysis of the overall performance of the radiometer requires end-to-end performance simulation from Earth emission to antenna brightness temperature, such as the global simulation of L-band brightness temperature simulation over land and sea [2]. To assist with the SMAP radiometer level 1B algorithm development, the SMAP forward brightness temperature simulator is developed by adapting the Aquarius simulator [2] with necessary modifications. This poster presents the current status of the SMAP forward brightness simulator s development including incorporating the land microwave emission model and its input datasets, and a simplified atmospheric radiative transfer model. The latest simulation results are also presented to demonstrate the ability of supporting the SMAP L1B algorithm development.

  3. iPTF discovery and classification of bright transients

    NASA Astrophysics Data System (ADS)

    Blagorodnova, Nadejda; Ho, Anna; Karamehmetoglu, Emir; Petrushevska, Tanja; Kupfer, Thomas; Adams, Scott; Cannella, Chris; Yan, Lin; Kasliwal, Mansi; Kulkarni, Shri; Neill, James D.; Walters, Richard

    2017-01-01

    The intermediate Palomar Transient Factory (ATel #4807) reports the discovery of the following bright transients. We report as ATel alerts all objects brighter than 19 mag. Our discoveries are reported in three filters: sdss-r, Mould-R and Mould-I, denoted as g, r and i. All three are in the AB magnitude system.

  4. High Precision Photometry of Bright Transiting Exoplanet Hosts

    NASA Astrophysics Data System (ADS)

    Wilson, Maurice; Eastman, Jason; Johnson, John A.

    2016-01-01

    Within the past two decades, the successful search for exoplanets and the characterization of their physical properties have shown the immense progress that has been made towards finding planets with characteristics similar to Earth. For most exoplanets with a radius about the size of Earth, evaluating their physical properties, such as the mass, radius and equilibrium temperature, cannot be determined with satisfactory precision. The MINiature Exoplanet Radial Velocity Array (MINERVA) was recently built to obtain spectroscopic and photometric measurements to find, confirm, and characterize Earth-like exoplanets. MINERVA's spectroscopic survey targets the brightest, nearby stars which are well-suited to the array's capabilities, while its primary photometric goal is to search for transits around these bright targets. Typically, it is difficult to find satisfactory comparison stars within a telescope's field of view when the primary target is very bright. This issue is resolved by using one of MINERVA's telescopes to observe the primary bright star while the other telescopes observe a distinct field of view that contains satisfactory bright comparison stars. We describe the code used to identify nearby comparison stars, schedule the four telescopes, produce differential photometry from multiple telescopes, and show the first results from this effort.This work has been funded by the Ronald E. McNair Post-Baccalaureate Achievement Program, the ERAU Honors Program, the ERAU Undergraduate Research Spark Fund, and the Banneker Institute at the Harvard-Smithsonian Center for Astrophysics.

  5. Apollo experiment S-211 low brightness, astronomical photography

    NASA Technical Reports Server (NTRS)

    Mercer, R. D.

    1974-01-01

    The low brightness image analysis for the Apollo flights is reported. The objectives of Experiment S-21 are discussed along with the photographic equipment, and the data processing and analysis flow are presented. Photographic data for Apollo 14, 15, 16, and 17 are included.

  6. Finding Bright-Spot Coordinates in Television Images

    NASA Technical Reports Server (NTRS)

    Richardson, T. E.; Tietz, J. C.

    1985-01-01

    Circuit provides data for computer to calculate coordinates of bright spot of light in video image. Calculation performed while image being scanned, and results available immediately at end of video frame. Video-processing circuit has variety of potential uses in commerce and industry. For example, locates tagged-parts on factory assembly line or track airplane landing lights.

  7. Reducing Color/Brightness Interaction in Color Television

    NASA Technical Reports Server (NTRS)

    Marchman, Robert H.

    1987-01-01

    Proposed digitally sampled scan-conversion scheme for color television reduces unwanted interactions between chrominance and luminance signals. New scheme reduces luminance and chrominance bandwidth to increase frequency separation between signals. To avoid proportionally reducing horizontal brightness resolution and horizontal color resolution, horizontal interlace of luminance signal and two color-difference signals used.

  8. Variations of the Solar Limb Brightness with the Oscillations

    NASA Astrophysics Data System (ADS)

    Schmieder, B.; Mein, P.

    The aim of this work is to compute the amplitude of the limb darkening fluctuations due to oscillations in order to compare it with the observations made with the heliometer at the Pic du Midi (Rösch and Yerle 1983 - 1984). It is shown that 5 min oscillations lead to variation in the brightness gradient of less than 2%.

  9. The 1997 Reference of Diffuse Night Sky Brightness

    NASA Technical Reports Server (NTRS)

    Leinert, C.; Bowyer, S.; Haikala, L. K.; Hanner, M. S.; Hauser, M. G.; Levasseur-Regourd, A. C.; Mann, I.; Mattila, K.; Reach, W. T.; Schlosser, W.; hide

    1997-01-01

    In the following we present material in tabular and graphical form, with the aim to allow the non specialist to obtain a realistic estimate of the diffuse night sky brightness over a wide range of wavelengths from the far UV longward of Ly to the far-infrared.

  10. Preparing Young Adolescents for a Bright Future--Right Now!

    ERIC Educational Resources Information Center

    Deering, Paul D.; Martin, Kathryn L.; Buelow, Stephanie M.; Hoffman, Jennifer T.; Cameli, Sandy; Martin, Matt; Walker, Robert E.; O'Neill, Tara B.

    2016-01-01

    We must prepare young adolescents for a bright future by examining all of our educational practices in terms of their current and future relevance. The education we provide our students must prepare them to address enormously complex issues involving demographics and international relations, environmental and human health, and the development and…

  11. Apparatus Would Position Bright Spot On Projection Screen

    NASA Technical Reports Server (NTRS)

    Rayman, Marc D.

    1996-01-01

    Proposed apparatus aims beam of visible light at wavelength lambda(2) to create bright spot at desired position in image on projection screen. Intended to replace handheld laser and flashlight pointers lecturers sometimes use to indicate features in projected images. Beam of light cannot be inadvertently aimed toward audience.

  12. Scattering models for the solar infrared F-corona brightness

    NASA Astrophysics Data System (ADS)

    Davidson, W. C.; MacQueen, R. M.; Mann, I.

    1995-02-01

    Model calculations are made of the infrared brightness in the solar F-corona motivated by recent infrared solar eclipse observations. Two different approaches are employed to describe the scattering properties of interplanetary dust : Mie scattering theory and diffraction theory, with and without an isotropic scattering term. In addition. two different particle size distributions are used in the calculations and the resultant line of sight brightness is compared with observational data of the solar F-corona between 3 and 8 solar radii ( R) in the ecliptic plane. It is found that the use of diffraction theory without an isotropic scattering contribution gives a very poor match with the observations, for both assumed particle size distributions. However, both the diffraction theory including isotropic scattering and the Mie scattering theory agree reasonably with the observed brightness, and especially its radial slope within the corona. for the model size distribution which is dominated by large particles. Only Mie theory may be employed in describing the second model size distribution because diffraction theory poorly describes the scattering due to the small particles which dominate this size distribution. It is concluded that the derivation of particle size distributions from the F-coronal brightness is still ambiguous and a further analysis needs either improved observations, or the application of further reasonable physical assumptions.

  13. Dark and Bright Material in a Crater Wall

    NASA Image and Video Library

    2012-03-28

    This image from NASA Dawn spacecraft shows part of a large crater that has an irregularly shaped, fresh rim and is distinctive because it has many outcrops of dark and bright material originating from its rim and from the interior slope of the crater.

  14. The "Brightness Rules" Alternative Conception for Light Bulb Circuits

    ERIC Educational Resources Information Center

    Bryan, Joel A.; Stuessy, Carol

    2006-01-01

    An alternative conception for the observed differences in light bulb brightness was revealed during an unguided inquiry investigation in which prospective elementary teachers placed identical bulbs in series, parallel, and combination direct current circuits. Classroom observations, document analyses, and video and audio transcriptions led to the…

  15. RESPONSES OF BRIGHT, NORMAL, AND RETARDED CHILDREN TO LEARNING TASKS.

    ERIC Educational Resources Information Center

    CARRIER, NEIL A.; AND OTHERS

    THE RELATIONSHIPS AMONG THE VARIABLES OF INTELLIGENCE, LEARNING TASK PERFORMANCE, EMOTIONAL TENSION, AND TASK MOTIVATION WERE STUDIED. ABOUT 120 BRIGHT, NORMAL, AND RETARDED CHILDREN PERFORMED SIX TRIALS OF NUMBER LEARNING, CONCEPT FORMATION, PROBLEM SOLVING, PERCEPTUAL-MOTOR COORDINATION, AND VERBAL LEARNING TASKS. DURING THE LEARNING SESSIONS,…

  16. Dynamical behaviour of photospheric bright points during merging

    NASA Astrophysics Data System (ADS)

    Criscuoli, S.; Stangalini, M.; Ermolli, I.; Zuccarello, F.; Cristaldi, A.; Falco, M.; Guglielmino, S.; Giorgi, F.

    2014-12-01

    We investigate the merging of bright points observed at high spatial and temporal resolution with CRISP/SST in a quiet region region. We analyze the MHD perturbations excited during the merging, their role in the energy budget of the magnetic structure and the potential role that they can play in heating the upper layers of the Sun's atmosphere.

  17. Proposal for a High-Brightness Pulsed Electron Source

    SciTech Connect

    Zolotorev, M.; Commins, E.D.; Heifets, S.; Sannibale, F.; /LBL, Berkeley /UC, Berkeley /SLAC

    2006-10-16

    We propose a novel scheme for a high-brightness pulsed electron source, which has the potential for many useful applications in electron microscopy, inverse photo-emission, low energy electron scattering experiments, and electron holography. A description of the proposed scheme is presented.

  18. View of bright-rayed crater on lunar farside

    NASA Technical Reports Server (NTRS)

    1969-01-01

    An Apollo 11 oblique view of a bright-rayed crater on the lunar farside. The crater is unnamed. The center of this photograph is located at 100 degrees east longitude and 4 degrees 30 minutes north latitude. This area is just east of Smyth's Sea.

  19. View of bright-rayed crater on lunar farside

    NASA Image and Video Library

    1969-07-16

    AS11-42-6285 (July 1969) --- An Apollo 11 view of a bright rayed crater on the lunar farside. The crater is unnamed. The center of this photograph is located at 100 degrees southeast longitude and 4 degrees 30 minutes north latitude. This area is just east of Smyth's Sea.

  20. iPTF discovery and identification of bright transients

    NASA Astrophysics Data System (ADS)

    Kupfer, Thomas; Ho, Anna; Karamehmetoglu, Emir; Petrushevska, Tanja; Adams, Scott; Neill, James D.; Walters, Richard; Cannella, Chris; Blagorodnova, Nadejda; Yan, Lin; Kulkarni, Shri

    2017-02-01

    The intermediate Palomar Transient Factory (ATel #4807) reports the discovery of the following bright transients. We report as ATel alerts all objects brighter than 19 mag. Our discoveries are reported in two filters: sdss-g and Mould-I, denoted as g, and I. Both are in the AB magnitude system.

  1. SKYMONITOR: A Global Network for Night Sky Brightness Measurements

    NASA Astrophysics Data System (ADS)

    McKenna, Dan; Davis, Donald; Boley, Paul

    2015-03-01

    We have deployed a network of autonomous photometers that continuously measures the night sky brightness in the visual region at two sky positions simultaneously, typically near the zenith and the second at an elevation angle of 20 degrees. The Photometers are calibrated as a network to better than 5.

  2. Preparing Young Adolescents for a Bright Future--Right Now!

    ERIC Educational Resources Information Center

    Deering, Paul D.; Martin, Kathryn L.; Buelow, Stephanie M.; Hoffman, Jennifer T.; Cameli, Sandy; Martin, Matt; Walker, Robert E.; O'Neill, Tara B.

    2016-01-01

    We must prepare young adolescents for a bright future by examining all of our educational practices in terms of their current and future relevance. The education we provide our students must prepare them to address enormously complex issues involving demographics and international relations, environmental and human health, and the development and…

  3. Variations in the Fe mineralogy of bright Martian soil

    NASA Technical Reports Server (NTRS)

    Murchie, Scott; Mustard, John; Erard, Stephane; Geissler, Paul; Singer, Robert

    1993-01-01

    Bright regions on Mars are interpreted as 'soil' derived by chemical alteration of crustal rocks, whose main pigmentary component is ferric oxide or oxyhydroxide. The mineralogy and mineralogic variability of ferric iron are important evidence for the evolution of Martian soil: mineralogy of ferric phases is sensitive to chemical conditions in their genetic environments, and the spatial distributions of different ferric phases would record a history of both chemical environments and physical mixing. Reflectance spectroscopic studies provide several types of evidence that discriminate possible pigmentary phases, including the position of a crystal field absorption near 0.9 microns and position and strengths of absorptions in the UV-visible wavelength region. Recent telescopic spectra and laboratory measurements of Mars soil analogs suggest that spectral features of bright soil can be explained based on a single pigmentary phase, hematite (alpha-Fe2O3), occurring in both 'nanophase' and more crystalline forms. Here we report on a systematic investigation of Martian bright regions using ISM imaging spectrometer data, in which we examined spatial variations in the position and shape of the approximately 0.9 microns absorption. We found both local and regional heterogeneities that indicate differences in Fe mineralogy. These results demonstrate that bright soils do not represent a single lithology that has been homogenized by eolian mixing, and suggest that weathering of soils in different geologic settings has followed different physical and chemical pathways.

  4. Finding Bright-Spot Coordinates in Television Images

    NASA Technical Reports Server (NTRS)

    Richardson, T. E.; Tietz, J. C.

    1985-01-01

    Circuit provides data for computer to calculate coordinates of bright spot of light in video image. Calculation performed while image being scanned, and results available immediately at end of video frame. Video-processing circuit has variety of potential uses in commerce and industry. For example, locates tagged-parts on factory assembly line or track airplane landing lights.

  5. Reducing Color/Brightness Interaction in Color Television

    NASA Technical Reports Server (NTRS)

    Marchman, Robert H.

    1987-01-01

    Proposed digitally sampled scan-conversion scheme for color television reduces unwanted interactions between chrominance and luminance signals. New scheme reduces luminance and chrominance bandwidth to increase frequency separation between signals. To avoid proportionally reducing horizontal brightness resolution and horizontal color resolution, horizontal interlace of luminance signal and two color-difference signals used.

  6. Integrated traditional Chinese medicine.

    PubMed

    Robinson, Nicola

    2006-05-01

    To experience the integration of traditional Chinese medicine (TCM) in China was 'the chance of a lifetime; thanks to the support of the Winston Churchill Memorial Trust. The scale and range of TCM available in terms of health care provision, education and research is unique in the world. This holistic integrative medicine is part of Chinese culture. Regulation and training of practitioners has similarities with current structures emerging in the UK in preparation for the statutory regulation for acupuncture and herbal medicine. China's research activity is a critical component of informing the debate on evidence-based practice and now real opportunities for collaboration and dissemination are beginning to emerge.

  7. FORCAST Observations of a Bright ToO Comet

    NASA Astrophysics Data System (ADS)

    Wooden, Diane

    2014-10-01

    We propose to measure the dust and organics of an unknown bright comet or comet outburst with this CY3 Target-of-Opportunity (ToO) proposal. A 5-27 micron spectrum coupled with 11, 19, and 31 micron dual-band photometry of a ToO bright comet with FORCAST will address our two primary goals: 1) characterize the coma dust mineralogy; and 2) identify organics in the critical 5-8 micron region. The crystalline fraction of comet dust has become a benchmark for models of heating and radial transport in our protoplanetary disk. In addition, by measuring the wavelengths, relative intensities, and feature asymmetries of crystalline peaks at 11.2, 19, and 23.5, 27.5, and 33 micron, the shapes of forsterite crystals can be constrained and their condensation temperatures inferred by comparison with theoretical and experimental data. Observations of cometary organics probe the unknown precursor materials that were transformed by heat into 'macromolecular carbon' found ubiquitously in carbonaceous chondrite samples from primitive asteroids. Thermal models fitted to FORCAST observations of a bright ToO comet determine the dust properties and the comet's dust properties links to the physical and chemical conditions in the solar nebula, and help to fulfill the SOFIA Science Case for Evolution of Our Solar System. We define a CY3 ToO bright comet as an unpredictable cometary outburst event or a comet discovered after the CY3 submission deadline that produces a comet with an integrated brightness of V<4 mag that is observable within CY3. A CY3 ToO comet will be at least as bright as CY3 target comet C/2013 US10 (Catalina). From 1995 through 2014, there are nine comet apparitions with V<6 mag, where six out of these nine were discovered within one year of perihelia and three were naked-eye within 2 months of discovery. FORCAST 5--31.5 micron observations of a bright comet will enable the study of dust mineral compositions and organic materials, will enable the search for controversial

  8. Impact of Ambient Bright Light on Agitation in Dementia

    PubMed Central

    Barrick, Ann Louise; Sloane, Philip D.; Williams, Christianna S.; Mitchell, C. Madeline; Connell, Bettye Rose; Wood, Wendy; Hickman, Susan E.; Preisser, John S.; Zimmerman, Sheryl

    2013-01-01

    Objective To evaluate the effect of ambient bright light therapy on agitation among institutionalized persons with dementia. Methods High intensity, low glare ambient lighting was installed in activity and dining areas of a state psychiatric hospital unit in North Carolina and a dementia-specific residential care facility in Oregon. The study employed a cluster-unit crossover design involving four ambient lighting conditions: AM bright light, PM bright light, All Day bright light, and Standard light. Sixty-six older persons with dementia participated. Outcome measures included direct observation by research personnel and completion by staff caregivers of the 14-item, short form of the Cohen-Mansfield Agitation Inventory (CMAI). Results Analyses of observational data revealed that for participants with mild/moderate dementia, agitation was higher under AM light (p=0.003), PM light (p<0.001), and All Day light (p=0.001) than Standard light. There also was a trend toward severely demented participants being more agitated during AM light than Standard light (p=0.053). Analysis of CMAI data identified differing responses by site: the North Carolina site significantly increased agitation under AM light (p=0.002) and PM light (p=0.013) compared with All Day light while in Oregon, agitation was higher for All Day light compared to AM light (p=0.030). In no comparison was agitation significantly lower under any therapeutic condition, in comparison to Standard lighting. Conclusions Ambient bright light is not effective in reducing agitation in dementia and may exacerbate this behavioral symptom. PMID:20104513

  9. SKYMONITOR: A Global Network for Sky Brightness Measurements

    NASA Astrophysics Data System (ADS)

    Davis, Donald R.; Mckenna, D.; Pulvermacher, R.; Everett, M.

    2010-01-01

    We are implementing a global network to measure sky brightness at dark-sky critical sites with the goal of creating a multi-decade database. The heart of this project is the Night Sky Brightness Monitor (NSBM), an autonomous 2 channel photometer which measures night sky brightness in the visual wavelengths (Mckenna et al, AAS 2009). Sky brightness is measured every minute at two elevation angles typically zenith and 20 degrees to monitor brightness and transparency. The NSBM consists of two parts, a remote unit and a base station with an internet connection. Currently these devices use 2.4 Ghz transceivers with a range of 100 meters. The remote unit is battery powered with daytime recharging using a solar panel. Data received by the base unit is transmitted via email protocol to IDA offices in Tucson where it will be collected, archived and made available to the user community via a web interface. Two other versions of the NSBM are under development: one for radio sensitive areas using an optical fiber link and the second that reads data directly to a laptop for sites without internet access. NSBM units are currently undergoing field testing at two observatories. With support from the National Science Foundation, we will construct and install a total of 10 units at astronomical observatories. With additional funding, we will locate additional units at other sites such as National Parks, dark-sky preserves and other sites where dark sky preservation is crucial. We will present the current comparison with the National Park Service sky monitoring camera. We anticipate that the SKYMONITOR network will be functioning by the end of 2010.

  10. Dust content of a hydrogen rich, low surface brightness galaxy and the luminosity history of 3C273

    NASA Technical Reports Server (NTRS)

    Hamilton, Thomas T.

    1993-01-01

    This project consists of a 30,000 second PSPC observation of the Giovanelli-Haynes Cloud in an attempt to detect light emitted by 3C273 which has been reflected by the cloud, and incidentally search the cloud for other sources of X-ray emission. The observation was carried out by ROSAT on Dec. 25, 1992 and the data was received by the P.I. in late March of 1993. We have examined the data and determined that the observation's background level, astrometry, etc. are acceptable. We have also detected diffuse emission from the direction of the Giovanelli-Haynes Cloud. Determination of the origin of this emission, by examining its morphology in relation to that of the radio map and the object's geometric relation with 3C273, requires software implementation of specialized algorithms. However, the most dramatic observation in the field is a potentially new population of discrete soft X-ray sources associated with dwarf galaxies.

  11. Characterizing the Population of Bright Infrared Sources in the Small Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Kraemer, K. E.; Sloan, G. C.; Wood, P. R.; Jones, O. C.; Egan, M. P.

    2017-01-01

    We have used the Infrared Spectrograph (IRS) on the Spitzer Space Telescope to observe stars in the Small Magellanic Cloud (SMC) selected from the Point Source Catalog of the Midcourse Space Experiment (MSX). We concentrate on the dust properties of the oxygen-rich evolved stars. The dust composition has smaller contributions from alumina compared to the Galaxy. This difference may arise from the lower metallicity in the SMC, but it could be a selection effect, as the SMC sample includes more stars that are brighter and thus more massive. The distribution of the SMC stars along the silicate sequence looks more like the Galactic sample of red supergiants than asymptotic giant branch stars (AGBs). While many of the SMC stars are definitively on the AGB, several also show evidence of hot bottom burning. Three of the supergiants show PAH emission at 11.3 μm. Two other sources show mixed chemistry, with both carbon-rich and oxygen-rich spectral features. One, MSX SMC 134, may be the first confirmed silicate/carbon star in the SMC. The other, MSX SMC 049, is a candidate post-AGB star. MSX SMC 145, previously considered a candidate OH/IR star, is actually an AGB star with a background galaxy at z = 0.16 along the same line of sight. We consider the overall characteristics of all the MSX sources, the most infrared-bright objects in the SMC, in light of the higher sensitivity and resolution of Spitzer, and compare them with the object types expected from the original selection criteria. This population represents what will be seen in more distant galaxies by the upcoming James Webb Space Telescope (JWST). Color-color diagrams generated from the IRS spectra and the mid-infrared filters on JWST show how one can separate evolved stars from young stellar objects (YSOs) and distinguish among different classes of YSOs.

  12. Dynamic resetting of the human circadian pacemaker by intermittent bright light

    NASA Technical Reports Server (NTRS)

    Rimmer, D. W.; Boivin, D. B.; Shanahan, T. L.; Kronauer, R. E.; Duffy, J. F.; Czeisler, C. A.

    2000-01-01

    In humans, experimental studies of circadian resetting typically have been limited to lengthy episodes of exposure to continuous bright light. To evaluate the time course of the human endogenous circadian pacemaker's resetting response to brief episodes of intermittent bright light, we studied 16 subjects assigned to one of two intermittent lighting conditions in which the subjects were presented with intermittent episodes of bright-light exposure at 25- or 90-min intervals. The effective duration of bright-light exposure was 31% or 63% compared with a continuous 5-h bright-light stimulus. Exposure to intermittent bright light elicited almost as great a resetting response compared with 5 h of continuous bright light. We conclude that exposure to intermittent bright light produces robust phase shifts of the endogenous circadian pacemaker. Furthermore, these results demonstrate that humans, like other species, exhibit an enhanced sensitivity to the initial minutes of bright-light exposure.

  13. Dynamic resetting of the human circadian pacemaker by intermittent bright light

    NASA Technical Reports Server (NTRS)

    Rimmer, D. W.; Boivin, D. B.; Shanahan, T. L.; Kronauer, R. E.; Duffy, J. F.; Czeisler, C. A.

    2000-01-01

    In humans, experimental studies of circadian resetting typically have been limited to lengthy episodes of exposure to continuous bright light. To evaluate the time course of the human endogenous circadian pacemaker's resetting response to brief episodes of intermittent bright light, we studied 16 subjects assigned to one of two intermittent lighting conditions in which the subjects were presented with intermittent episodes of bright-light exposure at 25- or 90-min intervals. The effective duration of bright-light exposure was 31% or 63% compared with a continuous 5-h bright-light stimulus. Exposure to intermittent bright light elicited almost as great a resetting response compared with 5 h of continuous bright light. We conclude that exposure to intermittent bright light produces robust phase shifts of the endogenous circadian pacemaker. Furthermore, these results demonstrate that humans, like other species, exhibit an enhanced sensitivity to the initial minutes of bright-light exposure.

  14. Platelet Rich Plasma and Knee Surgery

    PubMed Central

    Sánchez, Mikel; Sánchez, Pello; Orive, Gorka; Anitua, Eduardo; Padilla, Sabino

    2014-01-01

    In orthopaedic surgery and sports medicine, the knee joint has traditionally been considered the workhorse. The reconstruction of every damaged element in this joint is crucial in achieving the surgeon's goal to restore the knee function and prevent degeneration towards osteoarthritis. In the last fifteen years, the field of regenerative medicine is witnessing a boost of autologous blood-derived platelet rich plasma products (PRPs) application to effectively mimic and accelerate the tissue healing process. The scientific rationale behind PRPs is the delivery of growth factors, cytokines, and adhesive proteins present in platelets and plasma, as well as other biologically active proteins conveyed by the plasma such as fibrinogen, prothrombin, and fibronectin; with this biological engineering approach, new perspectives in knee surgery were opened. This work describes the use of PRP to construct and repair every single anatomical structure involved in knee surgery, detailing the process conducted in ligament, meniscal, and chondral surgery. PMID:25302310

  15. Traditional Chinese medicine.

    PubMed

    Nestler, Gary

    2002-01-01

    According to an article by Wald in the November 2000 issue of Strategic Healthcare Marketing, through physician education, integrated medicine shall continue to be adopted by conventional medical establishments in the United States. With many leading medical schools now adding courses on alternative medicine and hospital administrators recognizing this growing trend, responding to the patients' needs and demands remains paramount. According to a study of 3200 physicians conducted by Health Products Research, physicians expect to offer and embrace therapeutic alternatives outside of the traditional pharmaceutical realm. Greater than 50% will begin or increase using alternative medicine in the next 12 months. Physicians also believe that patient acceptance is greater for alternative therapies, resulting in therapeutic compliance. Most physicians continue to be skeptical about certain treatments, citing a lack of clinical information. With these factors understood, more clinical research to be completed in a teaching hospital environment becomes paramount.

  16. An Improved Cluster Richness Estimator

    SciTech Connect

    Rozo, Eduardo; Rykoff, Eli S.; Koester, Benjamin P.; McKay, Timothy; Hao, Jiangang; Evrard, August; Wechsler, Risa H.; Hansen, Sarah; Sheldon, Erin; Johnston, David; Becker, Matthew R.; Annis, James T.; Bleem, Lindsey; Scranton, Ryan; /Pittsburgh U.

    2009-08-03

    Minimizing the scatter between cluster mass and accessible observables is an important goal for cluster cosmology. In this work, we introduce a new matched filter richness estimator, and test its performance using the maxBCG cluster catalog. Our new estimator significantly reduces the variance in the L{sub X}-richness relation, from {sigma}{sub lnL{sub X}}{sup 2} = (0.86 {+-} 0.02){sup 2} to {sigma}{sub lnL{sub X}}{sup 2} = (0.69 {+-} 0.02){sup 2}. Relative to the maxBCG richness estimate, it also removes the strong redshift dependence of the richness scaling relations, and is significantly more robust to photometric and redshift errors. These improvements are largely due to our more sophisticated treatment of galaxy color data. We also demonstrate the scatter in the L{sub X}-richness relation depends on the aperture used to estimate cluster richness, and introduce a novel approach for optimizing said aperture which can be easily generalized to other mass tracers.

  17. Metre-size bright spots at the surface of comet 67P/Churyumov-Gerasimenko: Interpretation of OSIRIS data using laboratory experiments

    NASA Astrophysics Data System (ADS)

    Pommerol, Antoine; Thomas, Nicolas; Antonella Barucci, M.; Bertaux, Jean-Loup; Davidsson, Björn; Ramy El-Maarry, Mohamed; La Forgia, Fiorengela; Fornasier, Sonia; Gracia, Antonio; Groussin, Olivier; Jost, Bernhard; Keller, Horst Uwe; Kuehrt, Ekkehard; Marschall, Raphael; Massironi, Matteo; Motolla, Stefano; Naletto, Giampiero; Oklay, Nilda; Pajola, Maurizio; Poch, Olivier

    2015-04-01

    Since the beginning of Rosetta's orbital observations, over a hundred small bright spots have been identified in images returned by its OSIRIS NAC camera, in all types of morphological regions on the nucleus. Bright spots are found as clusters of several tens of individuals in the vicinity of cliffs, or isolated without clear structural relation to the surrounding terrain. They are however mostly observed in the areas of the nucleus currently receiving the lowest amount of insolation and some of the best examples appear completely surrounded by shadows. Their typical sizes are of the order of a few metres and they are often observed at the surfaces of boulders of larger dimension. The brightness of these spots is up to ten times the average brightness of the surrounding terrain and multi-spectral analyses show a significantly bluer spectrum over the 0.3-1µm range. Comparisons of images taken in September and November 2014 under similar illumination conditions do not show any significant change of these features. Analysis of the results of past and present laboratory experiments with H2O-ice/dust mixtures provide interesting insights about the nature and origin of the bright spots. In particular, recent sublimation experiments conducted at the University of Bern reproduce the spectro-photometric variability observed at the surface of the nucleus by sequences of formation and ejection of a mantle of refractory organic-rich dust at the surface of the icy material. The formation of hardened layers of ice by sintering/re-condensation below the uppermost dust layer can also have strong implications for both the photometric and mechanical properties of the subsurface layer. Based on the comparison between OSIRIS observations and laboratory results, our favoured interpretation of the observed features is that the bright spots are exposures of water ice, resulting from the removal of the uppermost layer of refractory dust that covers the rest of the nucleus. Some of the

  18. Platelet-rich plasma and plantar fasciitis.

    PubMed

    Monto, Raymond R

    2013-12-01

    Plantar fasciitis is the most common cause of heel pain and can prove difficult to treat in its most chronic and severe forms. Advanced cases of plantar fasciitis are often associated with ankle stiffness, heel spurs, and other conditions and can lead to extensive physical disability and financial loss. Most available traditional treatments, including orthoses, nonsteroidal anti-inflammatory drugs, and steroid injections have a paucity of supportive clinical evidence. More invasive treatments, ranging from corticosteroid and botulinum-A toxin injections to shockwave therapy and plantar fasciotomy, have demonstrated varying clinical success in severe cases but carry the potential for serious complication and permanent disability. Platelet-rich plasma has recently been demonstrated to be helpful in managing chronic severe tendinopathies when other techniques have failed. This review examines the pathophysiology, diagnostic options, nonoperative treatment modalities, and surgical options currently used for plantar fasciitis. It also focuses on the clinical rationale and available evidence for using autologous platelet-rich plasma to treat severe refractory chronic plantar fasciitis.

  19. Ultra-bright pulsed electron beam with low longitudinal emittance

    DOEpatents

    Zolotorev, Max

    2010-07-13

    A high-brightness pulsed electron source, which has the potential for many useful applications in electron microscopy, inverse photo-emission, low energy electron scattering experiments, and electron holography has been described. The source makes use of Cs atoms in an atomic beam. The source is cycled beginning with a laser pulse that excites a single Cs atom on average to a band of high-lying Rydberg nP states. The resulting valence electron Rydberg wave packet evolves in a nearly classical Kepler orbit. When the electron reaches apogee, an electric field pulse is applied that ionizes the atom and accelerates the electron away from its parent ion. The collection of electron wave packets thus generated in a series of cycles can occupy a phase volume near the quantum limit and it can possess very high brightness. Each wave packet can exhibit a considerable degree of coherence.

  20. Countermeasure against tailored bright illumination attack for DPS-QKD.

    PubMed

    Honjo, Toshimori; Fujiwara, Mikio; Shimizu, Kaoru; Tamaki, Kiyoshi; Miki, Shigehito; Yamashita, Taro; Terai, Hirotaka; Wang, Zhen; Sasaki, Masahide

    2013-02-11

    We propose a countermeasure against the so-called tailored bright illumination attack for differential-phase-shift QKD (DPS-QKD). By monitoring a rate of coincidence detection at a pair of superconducting nanowire single-photon detectors (SSPDs) which is connected at each of the output ports of Bob's Mach-Zehnder interferometer, Alice and Bob can detect and defeat this kind of attack. We also experimentally confirmed the feasibility of this countermeasure using our 1 GHz-clocked DPS-QKD system. In the emulation of the attack, we achieved much lower power of the bright illumination light compared with the original demonstration by using a pulse stream instead of broad pulses.

  1. Bright-White Beetle Scales Optimise Multiple Scattering of Light

    PubMed Central

    Burresi, Matteo; Cortese, Lorenzo; Pattelli, Lorenzo; Kolle, Mathias; Vukusic, Peter; Wiersma, Diederik S.; Steiner, Ullrich; Vignolini, Silvia

    2014-01-01

    Whiteness arises from diffuse and broadband reflection of light typically achieved through optical scattering in randomly structured media. In contrast to structural colour due to coherent scattering, white appearance generally requires a relatively thick system comprising randomly positioned high refractive-index scattering centres. Here, we show that the exceptionally bright white appearance of Cyphochilus and Lepidiota stigma beetles arises from a remarkably optimised anisotropy of intra-scale chitin networks, which act as a dense scattering media. Using time-resolved measurements, we show that light propagating in the scales of the beetles undergoes pronounced multiple scattering that is associated with the lowest transport mean free path reported to date for low-refractive-index systems. Our light transport investigation unveil high level of optimisation that achieves high-brightness white in a thin low-mass-per-unit-area anisotropic disordered nanostructure. PMID:25123449

  2. Performance test of high brightness nano-aperture ion source

    NASA Astrophysics Data System (ADS)

    Xu, Xinxin; Raman, P. Santhana; Pang, Rudy; Liu, Nannan; Khursheed, Anjam; van Kan, Jeroen A.

    2017-08-01

    The nano-aperture ion source (NAIS) is a candidate to be part of a compact proton beam writing system, which has the potential of high throughput with sub 10 nm spot sizes. To evaluate the performance of this ion source, different NAIS chip configurations were examined through simulation. This study suggests that a proton reduced brightness of more than 106 A/(m2srV) can be achieved, with an ion energy spread of less than 1 eV. Meanwhile, a prototype NAIS has been fabricated and tested to deliver 800 A/(m2srV) of reduced brightness for Ar+ beam. Current limitations and further improvements of this prototype NAIS are discussed.

  3. Temperature and brightness distribution in the components of binary systems

    NASA Astrophysics Data System (ADS)

    Barman, S. K.

    1993-03-01

    From the theoretical model of a binary system for gravity darkening (Barman 1991), the temperature and brightness distributions along the surface of the components have been calculated using the third and fourth orders of the ratio (r/R) in the tidal potentials created by the secondary components, where r is radial distance and R the distance between the centers of gravities of the binary stars. Results of both distributions have been presented in seven figures. On analyzing the results, it has been suggested that if the expansion technique be used to calculate the combined potentials and related matters e.g. the temperature and brightness distributions of a binary system, one should at least consider the fourth order of the ratio (r/R).

  4. Fast microtomography using bright monochromatic x-rays

    SciTech Connect

    Jung, J. W.; Lee, J. S.; Park, S. J.; Chang, S.; Pyo, J.; Kwon, N.; Kim, J.; Kohmura, Y.; Nishino, Y.; Yamamoto, M.; Ishikawa, T.

    2012-09-15

    A fast microtomography system for high-resolution high-speed imaging has been developed using bright monochromatic x-rays at the BL29XU beamline of SPring-8. The shortest scan time for microtomography we attained was 0.25 s in 1.25 {mu}m effective pixel size by combining the bright monochromatic x-rays, a fast rotating sample stage, and a high performance x-ray imaging detector. The feasibility of the tomography system was successfully demonstrated by visualization of rising bubbles in a viscous liquid, an interesting issue in multiphase flow physics. This system also provides a high spatial (a measurable feature size of 300 nm) or a very high temporal (9.8 {mu}s) resolution in radiographs.

  5. Fast microtomography using bright monochromatic x-rays.

    PubMed

    Jung, J W; Lee, J S; Kwon, N; Park, S J; Chang, S; Kim, J; Pyo, J; Kohmura, Y; Nishino, Y; Yamamoto, M; Ishikawa, T; Je, J H

    2012-09-01

    A fast microtomography system for high-resolution high-speed imaging has been developed using bright monochromatic x-rays at the BL29XU beamline of SPring-8. The shortest scan time for microtomography we attained was 0.25 s in 1.25 μm effective pixel size by combining the bright monochromatic x-rays, a fast rotating sample stage, and a high performance x-ray imaging detector. The feasibility of the tomography system was successfully demonstrated by visualization of rising bubbles in a viscous liquid, an interesting issue in multiphase flow physics. This system also provides a high spatial (a measurable feature size of 300 nm) or a very high temporal (9.8 μs) resolution in radiographs.

  6. Bright-White Beetle Scales Optimise Multiple Scattering of Light

    NASA Astrophysics Data System (ADS)

    Burresi, Matteo; Cortese, Lorenzo; Pattelli, Lorenzo; Kolle, Mathias; Vukusic, Peter; Wiersma, Diederik S.; Steiner, Ullrich; Vignolini, Silvia

    2014-08-01

    Whiteness arises from diffuse and broadband reflection of light typically achieved through optical scattering in randomly structured media. In contrast to structural colour due to coherent scattering, white appearance generally requires a relatively thick system comprising randomly positioned high refractive-index scattering centres. Here, we show that the exceptionally bright white appearance of Cyphochilus and Lepidiota stigma beetles arises from a remarkably optimised anisotropy of intra-scale chitin networks, which act as a dense scattering media. Using time-resolved measurements, we show that light propagating in the scales of the beetles undergoes pronounced multiple scattering that is associated with the lowest transport mean free path reported to date for low-refractive-index systems. Our light transport investigation unveil high level of optimisation that achieves high-brightness white in a thin low-mass-per-unit-area anisotropic disordered nanostructure.

  7. Improvement in brightness of multicusp-plasma ion source

    NASA Astrophysics Data System (ADS)

    Ji, Q.; Jiang, X.; King, T. J.; Leung, K. N.; Standiford, K.

    2002-05-01

    The beam brightness of a multicusp-plasma ion source has been substantially improved by optimizing the source configuration and extractor geometry. The current density of a 2 keV He+ beam extracted from a 7.5-cm-diameter source operating at 2.5 kW RF power is approx. 100 mA/cm2, which is approx. 10 times larger than that of a beam extracted from a 5-cm-diameter source operating at 1 kW RF power. A smaller focused beam spot size is achieved with a counter-bored extractor instead of a conventional (through-hole) extractor, resulting another order of magnitude improvement in beam current density. Measured brightness can be as high as 440 A/cm2Sr, which represents a 30 times improvement over prior work.

  8. Integration, test and operation of the BRIght Target Explorer payload

    NASA Astrophysics Data System (ADS)

    Chaumont, Monica J. M.

    The BRIght Target Explorer mission consists of six nanosatellites, each equipped with an instrument capable of capturing defocused images of stars suitable for milli-magnitude accuracy differential photometry. BRITE is expected to provide information about the dynamics and life cycles of bright stars. The satellites are funded in pairs by Austria, Poland and Canada and designed at the University of Toronto Institute for Aerospace Studies, Space Flight Laboratory. The present thesis document summarizes the contribution of the author to this project. This includes unit level integration, calibration, functional testing and science acceptance testing of the two BRITE Canada payloads; high level assembly and spacecraft level testing of the BRITE Canada spacecraft; sun stare testing and ground based observations of stars with engineering model instruments; launch campaign functional testing and preparations of UniBRITE, the first BRITE satellite funded by Austria; and on-orbit operations of UniBRITE.

  9. Extremely High Current, High-Brightness Energy Recovery Linac

    SciTech Connect

    I. Ben-Zvi; D.S. Barton; D.B. Beavis; M. Blaskiewicz; J.M. Brennan; A. Burrill; R. Calaga; P. Cameron; X.Y. Chang; R. Connolly; D.M. Gassner; J.G. Grimes; H. Hahn; A. Hershcovitch; H.-C. Hseuh; P.D.J. Johnson; D. Kayran; J. Kewisch; R.F. Lambiase; V. Litvinenko; G.T. McIntyre; W. Meng; T.C.N. Nehring; T. Nicoletti; B. Oerter; D. Pate; J. Rank; T. Rao; T. Roser; T. Russo; J. Scaduto; Z. Segalov; K. Smith; N.W.W. Williams; K.-C. Wu; V. Yakimenko; K. Yip; A. Zaltsman; Y. Zhao; H. Bluem; A. Burger; M.D. Cole; A.J. Favale; D. Holmes; J. Rathke; T. Schultheiss; A.M.M. Todd; J.R. Delayen; L. W. Funk; P. Kneisel; H.L. Phillips; J.P. Preble

    2005-05-16

    Next generation ERL light-sources, high-energy electron coolers, high-power Free-Electron Lasers, powerful Compton X-ray sources and many other accelerators were made possible by the emerging technology of high-power, high-brightness electron beams. In order to get the anticipated performance level of ampere-class currents, many technological barriers are yet to be broken. BNL's Collider-Accelerator Department is pursuing some of these technologies for its electron cooling of RHIC application, as well as a possible future electron-hadron collider. We will describe work on CW, high-current and high-brightness electron beams. This will include a description of a superconducting, laser-photocathode RF gun and an accelerator cavity capable of producing low emittance (about 1 micron rms normalized) one nano-Coulomb bunches at currents of the order of one ampere average.

  10. EXTREMELY HIGH CURRECT, HIGH-BRIGHTNESS ENERGY RECOVERY LINAC.

    SciTech Connect

    BEN-ZVI, I.; BARTON, D.; BEAVIS, D. BLASKIEWICZ, M.; ET AL.

    2005-05-16

    Next generation ERL light-sources, high-energy electron coolers, high-power Free-Electron Lasers, powerful Compton X-ray sources and many other accelerators were made possible by the emerging technology of high-power, high-brightness electron beams. In order to get the anticipated performance level of ampere-class currents, many technological barriers are yet to be broken. BNL's Collider-Accelerator Department is pursuing some of these technologies for its electron cooling of RHIC application, as well as a possible future electron-hadron collider. We will describe work on CW, high-current and high-brightness electron beams. This will include a description of a superconducting, laser-photocathode RF gun and an accelerator cavity capable of producing low emittance (about 1 micron rms normalized) one nano-Coulomb bunches at currents of the order of one ampere average.

  11. Species richness and endemism in the native flora of California.

    PubMed

    Baldwin, Bruce G; Thornhill, Andrew H; Freyman, William A; Ackerly, David D; Kling, Matthew M; Morueta-Holme, Naia; Mishler, Brent D

    2017-03-01

    California's vascular flora is the most diverse and threatened in temperate North America. Previous studies of spatial patterns of Californian plant diversity have been limited by traditional metrics, non-uniform geographic units, and distributional data derived from floristic descriptions for only a subset of species. We revisited patterns of sampling intensity, species richness, and relative endemism in California based on equal-area spatial units, the full vascular flora, and specimen-based distributional data. We estimated richness, weighted endemism (inverse range-weighting of species), and corrected weighted endemism (weighted endemism corrected for richness), and performed a randomization test for significantly high endemism. Possible biases in herbarium data do not obscure patterns of high richness and endemism at the spatial resolution studied. High species richness was sometimes associated with significantly high endemism (e.g., Klamath Ranges) but often not. In Stebbins and Major's (1965) main endemism hotspot, Southwestern California, species richness is high across much of the Peninsular and Transverse ranges but significantly high endemism is mostly localized to the Santa Rosa and San Bernardino mountains. In contrast, species richness is low in the Channel Islands, where endemism is significantly high, as also found for much of the Death Valley region. Measures of taxonomic richness, even with greater weighting of range-restricted taxa, are insufficient for identifying areas of significantly high endemism that warrant conservation attention. Differences between our findings and those in previous studies appear to mostly reflect the source and scale of distributional data, and recent analytical refinements. © 2017 Botanical Society of America.

  12. Research Traditions, Diversity, and Progress.

    ERIC Educational Resources Information Center

    Buchmann, Margret; Floden, Robert E.

    1989-01-01

    An assessment is provided of two papers responding to an article by P. Atkinson, S. Delamont, and M. Hammersley (1988) critiquing papers by E. Jacob (1987, 1988) on qualitative research traditions. Definitions of "tradition" and "research tradition," and the necessity to include British research in Jacob's meta-analysis are…

  13. Adaptive Reactive Rich Internet Applications

    NASA Astrophysics Data System (ADS)

    Schmidt, Kay-Uwe; Stühmer, Roland; Dörflinger, Jörg; Rahmani, Tirdad; Thomas, Susan; Stojanovic, Ljiljana

    Rich Internet Applications significantly raise the user experience compared with legacy page-based Web applications because of their highly responsive user interfaces. Although this is a tremendous advance, it does not solve the problem of the one-size-fits-all approach1 of current Web applications. So although Rich Internet Applications put the user in a position to interact seamlessly with the Web application, they do not adapt to the context in which the user is currently working. In this paper we address the on-the-fly personalization of Rich Internet Applications. We introduce the concept of ARRIAs: Adaptive Reactive Rich Internet Applications and elaborate on how they are able to adapt to the current working context the user is engaged in. An architecture for the ad hoc adaptation of Rich Internet Applications is presented as well as a holistic framework and tools for the realization of our on-the-fly personalization approach. We divided both the architecture and the framework into two levels: offline/design-time and online/run-time. For design-time we explain how to use ontologies in order to annotate Rich Internet Applications and how to use these annotations for conceptual Web usage mining. Furthermore, we describe how to create client-side executable rules from the semantic data mining results. We present our declarative lightweight rule language tailored to the needs of being executed directly on the client. Because of the event-driven nature of the user interfaces of Rich Internet Applications, we designed a lightweight rule language based on the event-condition-action paradigm.2 At run-time the interactions of a user are tracked directly on the client and in real-time a user model is built up. The user model then acts as input to and is evaluated by our client-side complex event processing and rule engine.

  14. Dark and bright blocker soliton interaction in defocusing waveguide arrays.

    PubMed

    Smirnov, Eugene; Rüter, Christian E; Stepić, Milutin; Shandarov, Vladimir; Kip, Detlef

    2006-11-13

    We experimentally demonstrate the interaction of an optical probe beam with both bright and dark blocker solitons formed with low optical light power in a saturable defocusing waveguide array in photorefractive lithium niobate. A phase insensitive interaction of the beams is achieved by means of counterpropagating light waves. Partial and full reflection (blocking) of the probe beam on the positive or negative light-induced defect is obtained, respectively, in good agreement with numerical simulations.

  15. Background Sky Brightness Measurements for Application to Space Surveillance Systems

    DTIC Science & Technology

    1981-05-29

    3) (4) (5) (6) (7) (8) Filter central wavelength X B2 B t Bds Bt-Bds Bbs Bz 400Lk 24?8 23.8 192 28.0 164 [87] 77 4i48A 27.8 18.5 154 14.3 140 63 77...waveeengths are deduced. A small influence of galactic spiral structure on surface brightness levels exists at 1 = 20 ( Sagittarius arm), 1 = 690 (Orion arm

  16. Winter sky brightness & cloud cover over Dome A

    NASA Astrophysics Data System (ADS)

    Yang, Yi; Moore, A. M.; Fu, J.; Ashley, M.; Cui, X.; Feng, L.; Gong, X.; Hu, Z.; Laurence, J.; LuongVan, D.; Riddle, R. L.; Shang, Z.; Sims, G.; Storey, J.; Tothill, N.; Travouillon, T.; Wang, L.; Yang, H.; Yang, J.; Zhou, X.; Zhu, Z.; Burton, M. G.

    2014-01-01

    At the summit of the Antarctic plateau, Dome A offers an intriguing location for future large scale optical astronomical Observatories. The Gattini DomeA project was created to measure the optical sky brightness and large area cloud cover of the winter-time sky above this high altitude Antarctic site. The wide field camera and multi-filter system was installed on the PLATO instrument module as part of the Chinese-led traverse to Dome A in January 2008. This automated wide field camera consists of an Apogee U4000 interline CCD coupled to a Nikon fish-eye lens enclosed in a heated container with glass window. The system contains a filter mechanism providing a suite of standard astronomical photometric filters (Bessell B, V, R), however, the absence of tracking systems, together with the ultra large field of view 85 degrees) and strong distortion have driven us to seek a unique way to build our data reduction pipeline. We present here the first measurements of sky brightness in the photometric B, V, and R band, cloud cover statistics measured during the 2009 winter season and an estimate of the transparency. In addition, we present example light curves for bright targets to emphasize the unprecedented observational window function available from this ground-based location. A ~0.2 magnitude agreement of our simultaneous test at Palomar Observatory with NSBM(National Sky Brightness Monitor), as well as an 0.04 magnitude photometric accuracy for typical 6th magnitude stars limited by the instrument design, indicating we obtained reasonable results based on our ~7mm effective aperture fish-eye lens.

  17. Brightness/darkness induction and the genesis of a contour

    PubMed Central

    Roncato, Sergio

    2014-01-01

    Visual contours often result from the integration or interpolation of fragmented edges. The strength of the completion increases when the edges share the same contrast polarity (CP). Here we demonstrate that the appearance in the perceptual field of this integrated unit, or contour of invariant CP, is concomitant with a vivid brightness alteration of the surfaces at its opposite sides. To observe this effect requires some stratagems because the formation in the visual field of a contour of invariant CP normally engenders the formation of a second contour and then the rise of two streams of induction signals that interfere in different ways. Particular configurations have been introduced that allow us to observe the induction effects of one contour taken in isolation. I documented these effects by phenomenological observations and psychophysical measurement of the brightness alteration in relation to luminance contrast. When the edges of the same CP complete to form a contour, the background of homogeneous luminance appears to dim at one side and to brighten at the opposite side (in accord with the CP). The strength of the phenomenon is proportional to the local luminance contrast. This effect weakens or nulls when the contour of the invariant CP separates surfaces filled with different gray shades. These conflicting results stimulate a deeper exploration of the induction phenomena and their role in the computation of brightness contrast. An alternative perspective is offered to account for some brightness illusions and their relation to the phenomenal transparency. The main assumption asserts that, when in the same region induction signals of opposite CP overlap, the filling-in is blocked unless the image is stratified into different layers, one for each signal of the same polarity. Phenomenological observations document this “solution” by the visual system. PMID:25368570

  18. Brightness/darkness induction and the genesis of a contour.

    PubMed

    Roncato, Sergio

    2014-01-01

    Visual contours often result from the integration or interpolation of fragmented edges. The strength of the completion increases when the edges share the same contrast polarity (CP). Here we demonstrate that the appearance in the perceptual field of this integrated unit, or contour of invariant CP, is concomitant with a vivid brightness alteration of the surfaces at its opposite sides. To observe this effect requires some stratagems because the formation in the visual field of a contour of invariant CP normally engenders the formation of a second contour and then the rise of two streams of induction signals that interfere in different ways. Particular configurations have been introduced that allow us to observe the induction effects of one contour taken in isolation. I documented these effects by phenomenological observations and psychophysical measurement of the brightness alteration in relation to luminance contrast. When the edges of the same CP complete to form a contour, the background of homogeneous luminance appears to dim at one side and to brighten at the opposite side (in accord with the CP). The strength of the phenomenon is proportional to the local luminance contrast. This effect weakens or nulls when the contour of the invariant CP separates surfaces filled with different gray shades. These conflicting results stimulate a deeper exploration of the induction phenomena and their role in the computation of brightness contrast. An alternative perspective is offered to account for some brightness illusions and their relation to the phenomenal transparency. The main assumption asserts that, when in the same region induction signals of opposite CP overlap, the filling-in is blocked unless the image is stratified into different layers, one for each signal of the same polarity. Phenomenological observations document this "solution" by the visual system.

  19. Hybrid bright-field and hologram imaging of cell dynamics

    NASA Astrophysics Data System (ADS)

    Byeon, Hyeokjun; Lee, Jaehyun; Doh, Junsang; Lee, Sang Joon

    2016-09-01

    Volumetric observation is essential for understanding the details of complex biological phenomena. In this study, a bright-field microscope, which provides information on a specific 2D plane, and a holographic microscope, which provides information spread over 3D volumes, are integrated to acquire two complementary images simultaneously. The developed system was successfully applied to capture distinct T-cell adhesion dynamics on inflamed endothelial layers, including capture, rolling, crawling, transendothelial migration, and subendothelial migration.

  20. GRB 990712 optical decay: indication of bright host galaxy.

    NASA Astrophysics Data System (ADS)

    Hjorth, J.; Courbin, F.; Cuadra, J.; Minniti, D.

    We have obtained a 5-min R-band exposure of the optical afterglow of GRB 990712 (Frontera, GCN #385; Bakos et al., GCN #387) with the ESO 3.5-m NTT on 16.403 July 1999 UT. We detect an unresolved (seeing FWHM = 1.8") object at RA (2000) = 22 31 53.03, Dec (2000) = -73 24 28.3 (with a positional uncertainty of +- 0.6" relative to the USNO-A2.0 system), consistent with the position of the bright decaying source discovered by Bakos et al. (IAUC 7225). We have tied our photometry to the PLANET photometric zeropoint (K. Sahu, personal communication) and find that the object has continued to fade to R = 21.48 +- 0.02 (systematic) +- 0.05 (random). The combined SAAO data (Bakos et al., IAUC 7225) and NTT data indicate that the light curve is leveling off relative to a power law decline. Assuming that the light curve can be modeled as the combined effects of a power law decline of the OT and a constant contribution from the host galaxy we find an OT decay slope of -0.81 (i.e. a rather slow decay) and a bright host galaxy with R = 22.0. Such a bright host galaxy would be consistent with its fairly low redshift (z = 0.43) and would possibly even account for the prominent emission lines seen in the VLT spectrum (Galama et al., GCN #388). We caution however that the hypothesis of a bright host galaxy is based on just a few data points. To test this hypothesis continued monitoring of the system is therefore urged. The NTT image and the R-band light curve are posted at http://www.astro.ku.dk/~jens/grb990712/ .

  1. A Study of Magnetic Fields on Bright-Rimmed Clouds

    NASA Astrophysics Data System (ADS)

    Kusune, Takayoshi; Sugitani, Koji

    2015-08-01

    Bright-rimmed clouds (BRCs), which are located at periphery of HII regions, are considered to be potential sites for induced star formation by UV radiation from nearby massive stars. Many theorists have developed 2D/3D hydrodynamical models to understand dynamical evolution of such molecular clouds. Most simulations, however, did not always include the magnetic field effect, which is of importance in the astrophysics. This is because that there are few observation results examining the magnetic field configuration of BRCs in detail. In order to obtain information on magnetic field in and around BRCs, we have made near-infrared (JHKs) imaging polarimetry toward 24 BRCs showing strong interaction with HII region (Urquhart et al. 2009). We used the imaging polarimeter SIRPOL/SIRIUS (FOV ~7.7’ x 7.7’) mounted on IRSF 1.4 m telescope at the South African Astronomical Observatory.We found that polarization vectors, i.e., magnetic fields inside the clouds, follow the curved bright rim just behind the bright rim for almost all of the observed BRCs. Our investigation into the relation between the ambient magnetic field direction and the UV radiation direction suggests a following tendency. In the case that the ambient magnetic field is perpendicular to the direction of incident UV radiation, the clouds are likely to have bright rims with small curvatures. On the other hand, in the case that the ambient field is parallel to the UV radiation, they would have those with larger curvatures. In this presentation, we will present the physical quantities for these BRCs (i.e., magnetic field strength, the post shock pressure by the ionization front, etc.) as well as these morphological results.

  2. Manakins can produce iridescent and bright feather colours without melanosomes.

    PubMed

    Igic, Branislav; D'Alba, Liliana; Shawkey, Matthew D

    2016-06-15

    Males of many species often use colourful and conspicuous ornaments to attract females. Among these, male manakins (family: Pipridae) provide classic examples of sexual selection favouring the evolution of bright and colourful plumage coloration. The highly iridescent feather colours of birds are most commonly produced by the periodic arrangement of melanin-containing organelles (melanosomes) within barbules. Melanin increases the saturation of iridescent colours seen from optimal viewing angles by absorbing back-scattered light; however, this may reduce the wide-angle brightness of these signals, contributing to a dark background appearance. We examined the nanostructure of four manakin species (Lepidothrix isidorei, L. iris, L. nattereri and L. coeruleocapilla) to identify how they produce their bright plumage colours. Feather barbs of all four species were characterized by dense and fibrous internal spongy matrices that likely increase scattering of light within the barb. The iridescent, yet pale or whitish colours of L. iris and L. nattereri feathers were produced not by periodically arranged melanosomes within barbules, but by periodic matrices of air and β-keratin within barbs. Lepidothrix iris crown feathers were able to produce a dazzling display of colours with small shifts in viewing geometry, likely because of a periodic nanostructure, a flattened barb morphology and disorder at a microstructural level. We hypothesize that iridescent plumage ornaments of male L. iris and L. nattereri are under selection to increase brightness or luminance across wide viewing angles, which may potentially increase their detectability by females during dynamic and fast-paced courtship displays in dim light environments.

  3. Bright spots among the world’s coral reefs

    NASA Astrophysics Data System (ADS)

    Cinner, Joshua E.; Huchery, Cindy; MacNeil, M. Aaron; Graham, Nicholas A. J.; McClanahan, Tim R.; Maina, Joseph; Maire, Eva; Kittinger, John N.; Hicks, Christina C.; Mora, Camilo; Allison, Edward H.; D'Agata, Stephanie; Hoey, Andrew; Feary, David A.; Crowder, Larry; Williams, Ivor D.; Kulbicki, Michel; Vigliola, Laurent; Wantiez, Laurent; Edgar, Graham; Stuart-Smith, Rick D.; Sandin, Stuart A.; Green, Alison L.; Hardt, Marah J.; Beger, Maria; Friedlander, Alan; Campbell, Stuart J.; Holmes, Katherine E.; Wilson, Shaun K.; Brokovich, Eran; Brooks, Andrew J.; Cruz-Motta, Juan J.; Booth, David J.; Chabanet, Pascale; Gough, Charlie; Tupper, Mark; Ferse, Sebastian C. A.; Sumaila, U. Rashid; Mouillot, David

    2016-07-01

    Ongoing declines in the structure and function of the world’s coral reefs require novel approaches to sustain these ecosystems and the millions of people who depend on them. A presently unexplored approach that draws on theory and practice in human health and rural development is to systematically identify and learn from the ‘outliers’—places where ecosystems are substantially better (‘bright spots’) or worse (‘dark spots’) than expected, given the environmental conditions and socioeconomic drivers they are exposed to. Here we compile data from more than 2,500 reefs worldwide and develop a Bayesian hierarchical model to generate expectations of how standing stocks of reef fish biomass are related to 18 socioeconomic drivers and environmental conditions. We identify 15 bright spots and 35 dark spots among our global survey of coral reefs, defined as sites that have biomass levels more than two standard deviations from expectations. Importantly, bright spots are not simply comprised of remote areas with low fishing pressure; they include localities where human populations and use of ecosystem resources is high, potentially providing insights into how communities have successfully confronted strong drivers of change. Conversely, dark spots are not necessarily the sites with the lowest absolute biomass and even include some remote, uninhabited locations often considered near pristine. We surveyed local experts about social, institutional, and environmental conditions at these sites to reveal that bright spots are characterized by strong sociocultural institutions such as customary taboos and marine tenure, high levels of local engagement in management, high dependence on marine resources, and beneficial environmental conditions such as deep-water refuges. Alternatively, dark spots are characterized by intensive capture and storage technology and a recent history of environmental shocks. Our results suggest that investments in strengthening fisheries

  4. High Brightness and high polarization electron source using transmission photocathode

    SciTech Connect

    Yamamoto, Naoto; Jin Xiuguang; Ujihara, Toru; Takeda, Yoshikazu; Mano, Atsushi; Nakagawa, Yasuhide; Nakanishi, Tsutomu; Okumi, Shoji; Yamamoto, Masahiro; Konomi, Taro; Ohshima, Takashi; Saka, Takashi; Kato, Toshihiro; Horinaka, Hiromichi; Yasue, Tsuneo; Koshikawa, Takanori

    2009-08-04

    A transmission photocathode was fabricated based on GaAs-GaAsP strained superlattice layers on a GaP substrate and a 20 kV-gun was built to generate the polarized electron beams with the diameter of a few micro-meter. As the results, the reduced brightness of 1.3x10{sup 7} A/cm{sup 2}/sr and the polarization of 90% were achieved.

  5. High-brightness switchable multiwavelength remote laser in air

    SciTech Connect

    Yao Jinping; Cheng Ya; Xu Zhizhan; Zeng Bin; Li Guihua; Chu Wei; Ni Jielei; Zhang Haisu; Xu Huailiang; Chin, See Leang

    2011-11-15

    We demonstrate a harmonic-seeded switchable multiwavelength laser in air driven by intense midinfrared femtosecond laser pulses, in which population inversion occurs at an ultrafast time scale (i.e., less than {approx}200 fs) owing to direct formation of excited molecular nitrogen ions by strong-field ionization of inner-valence electrons. The bright multiwavelength laser in air opens the perspective for remote detection of multiple pollutants based on nonlinear optical spectroscopy.

  6. Human Adolescent Phase Response Curves to Bright White Light.

    PubMed

    Crowley, Stephanie J; Eastman, Charmane I

    2017-08-01

    Older adolescents are particularly vulnerable to circadian misalignment and sleep restriction, primarily due to early school start times. Light can shift the circadian system and could help attenuate circadian misalignment; however, a phase response curve (PRC) to determine the optimal time for receiving light and avoiding light is not available for adolescents. We constructed light PRCs for late pubertal to postpubertal adolescents aged 14 to 17 years. Participants completed 2 counterbalanced 5-day laboratory sessions after 8 or 9 days of scheduled sleep at home. Each session included phase assessments to measure the dim light melatonin onset (DLMO) before and after 3 days of free-running through an ultradian light-dark (wake-sleep) cycle (2 h dim [~20 lux] light, 2 h dark). In one session, intermittent bright white light (~5000 lux; four 20-min exposures) was alternated with 10 min of dim room light once per day for 3 consecutive days. The time of light varied among participants to cover the 24-h day. For each individual, the phase shift to bright light was corrected for the free-run derived from the other laboratory session with no bright light. One PRC showed phase shifts in response to light start time relative to the DLMO and another relative to home sleep. Phase delay shifts occurred around the hours corresponding to home bedtime. Phase advances occurred during the hours surrounding wake time and later in the afternoon. The transition from delays to advances occurred at the midpoint of home sleep. The adolescent PRCs presented here provide a valuable tool to time bright light in adolescents.

  7. Hybrid bright-field and hologram imaging of cell dynamics

    PubMed Central

    Byeon, Hyeokjun; Lee, Jaehyun; Doh, Junsang; Lee, Sang Joon

    2016-01-01

    Volumetric observation is essential for understanding the details of complex biological phenomena. In this study, a bright-field microscope, which provides information on a specific 2D plane, and a holographic microscope, which provides information spread over 3D volumes, are integrated to acquire two complementary images simultaneously. The developed system was successfully applied to capture distinct T-cell adhesion dynamics on inflamed endothelial layers, including capture, rolling, crawling, transendothelial migration, and subendothelial migration. PMID:27640337

  8. Perception of Lightness and Brightness in Complex Patterns

    DTIC Science & Technology

    1993-06-30

    luminance) and local brightness contrasts were all measured using the same stimulus patterns. According to a number of models , lightness is closely related...manuscripts were submitted to Perception and Psy-chophysics and are now in press. The main conclusions are quite simple. Wallach’s and Shapley’s models are...which the surrounding high contrast pattern influences the apparent contrast of test patterns that are similar in spatial frequency spectrum and phase to

  9. THE RAVE SURVEY: RICH IN VERY METAL-POOR STARS

    SciTech Connect

    Fulbright, Jon P.; Wyse, Rosemary F. G.; Ruchti, Gregory R.; Gilmore, G. F.; Grebel, Eva; Bienayme, O.; Siebert, A.; Binney, J.; Bland-Hawthorn, J.; Campbell, R.; Freeman, K. C.; Gibson, B. K.; Helmi, A.; Munari, U.; Navarro, J. F.; Siviero, A.; Parker, Q. A.; Reid, W.; Seabroke, G. M.; Steinmetz, M.

    2010-11-20

    Very metal-poor stars are of obvious importance for many problems in chemical evolution, star formation, and galaxy evolution. Finding complete samples of such stars which are also bright enough to allow high-precision individual analyses is of considerable interest. We demonstrate here that stars with iron abundances [Fe/H] <-2 dex, and down to below -4 dex, can be efficiently identified within the Radial Velocity Experiment (RAVE) survey of bright stars, without requiring additional confirmatory observations. We determine a calibration of the equivalent width of the calcium triplet lines measured from the RAVE spectra onto true [Fe/H], using high spectral resolution data for a subset of the stars. These RAVE iron abundances are accurate enough to obviate the need for confirmatory higher-resolution spectroscopy. Our initial study has identified 631 stars with [Fe/H] {<=}-2, from a RAVE database containing approximately 200,000 stars. This RAVE-based sample is complete for stars with [Fe/H] {approx_lt}-2.5, allowing statistical sample analysis. We identify three stars with [Fe/H] {approx_lt}-4. Of these, one was already known to be 'ultra metal-poor', one is a known carbon-enhanced metal-poor star, but we obtain [Fe/H] = -4.0, rather than the published [Fe/H] = -3.3, and derive [C/Fe] = +0.9, and [N/Fe] = +3.2, and the third is at the limit of our signal-to-noise ratio. RAVE observations are ongoing and should prove to be a rich source of bright, easily studied, very metal-poor stars.

  10. The RAVE Survey: Rich in Very Metal-poor Stars

    NASA Astrophysics Data System (ADS)

    Fulbright, Jon P.; Wyse, Rosemary F. G.; Ruchti, Gregory R.; Gilmore, G. F.; Grebel, Eva; Bienaymé, O.; Binney, J.; Bland-Hawthorn, J.; Campbell, R.; Freeman, K. C.; Gibson, B. K.; Helmi, A.; Munari, U.; Navarro, J. F.; Parker, Q. A.; Reid, W.; Seabroke, G. M.; Siebert, A.; Siviero, A.; Steinmetz, M.; Watson, F. G.; Williams, M.; Zwitter, T.

    2010-11-01

    Very metal-poor stars are of obvious importance for many problems in chemical evolution, star formation, and galaxy evolution. Finding complete samples of such stars which are also bright enough to allow high-precision individual analyses is of considerable interest. We demonstrate here that stars with iron abundances [Fe/H] <-2 dex, and down to below -4 dex, can be efficiently identified within the Radial Velocity Experiment (RAVE) survey of bright stars, without requiring additional confirmatory observations. We determine a calibration of the equivalent width of the calcium triplet lines measured from the RAVE spectra onto true [Fe/H], using high spectral resolution data for a subset of the stars. These RAVE iron abundances are accurate enough to obviate the need for confirmatory higher-resolution spectroscopy. Our initial study has identified 631 stars with [Fe/H] <=-2, from a RAVE database containing approximately 200,000 stars. This RAVE-based sample is complete for stars with [Fe/H] lsim-2.5, allowing statistical sample analysis. We identify three stars with [Fe/H] lsim-4. Of these, one was already known to be "ultra metal-poor," one is a known carbon-enhanced metal-poor star, but we obtain [Fe/H] = -4.0, rather than the published [Fe/H] = -3.3, and derive [C/Fe] = +0.9, and [N/Fe] = +3.2, and the third is at the limit of our signal-to-noise ratio. RAVE observations are ongoing and should prove to be a rich source of bright, easily studied, very metal-poor stars. Based in part on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere, Chile, in the framework of proposals 081.B-0900 and 080.B-0927.

  11. HI--line Observations of Low Surface Brightness Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Thomas, D. L.; Taylor, C. L.; Brinks, E.; Skillman, E. D.

    1995-12-01

    We present HI--line observations of low--surface brightness (LSB) dwarf galaxies to survey their nearby environment (r <= 100 kpc) for HI bright companions. It is possible that star formation histories in dwarf galaxies can be strongly affected by interactions with nearby companions. If massive star formation can be triggered by galaxy--galaxy interactions, then the absence of such interactions likely explains the lack of star formation in LSB dwarf galaxies relative to their high surface brightness counterparts (HII galaxies). Taylor et al. (1995, ApJS, 99, 427) surveyed a sample of HII galaxies and found that 60% of the sample had nearby HI companions. In our sample of 18 LSB galaxies, we found that only 22% had companions detectable in HI. Furthermore, we find that the peak column densities for the LSB sample are all below {10(21) } HI atoms cm(-2) . This is below the empirically established level needed for star formation to occur in dwarf galaxies as discussed by Skillman (1987, in Star Formation in Galaxies, ed. C.J. Lonsdale Persson (NASA Conf. Pub. CP--2466), p.263), Kennicutt (1989, ApJ, 344, 685), van der Hulst et al. (1993, AJ, 106, 548), and Taylor et al. (1994, AJ, 107, 971).

  12. Bright Soil Churned by Spirit's Sol 1861 Drive

    NASA Technical Reports Server (NTRS)

    2009-01-01

    NASA's Mars Exploration Rover Spirit drove 22.7 meters (74 feet) toward the southwest on the 1,861st Martian day, or sol, of Spirit's mission on Mars (March 28, 2009). After the drive, the rover took this image with its front hazard-avoidance camera, looking back at the tracks from the drive.

    As usual since losing the use of its right-front wheel in 2006, Spirit drove backwards. The immobile right-front wheel churned up a long stripe of bright soil during this drive. Where Spirit has found such bright soil in the past, subsequent analysis of the composition found concentrations of sulfur or silica that testified to past action of water at the site. When members of the rover team saw the large quantity of bright soil exposed by the Sol 1861 drive, they quickly laid plans to investigate the composition with Spirit's alpha particle X-ray spectrometer.

    The Sol 1861 drive took the rover past the northwest corner of the low plateau called 'Home Plate,' making progress on a route around the western side of Home Plate. The edge of Home Plate forms the horizon on the right side of this image. Husband Hill is on the horizon on the left side. For scale, the parallel rover wheel tracks are about 1 meter (40 inches) apart. The rover's hazard-avoidance cameras take 'fisheye' wide-angle images.

  13. Bright Soil Churned by Spirit's Sol 1861 Drive

    NASA Technical Reports Server (NTRS)

    2009-01-01

    NASA's Mars Exploration Rover Spirit drove 22.7 meters (74 feet) toward the southwest on the 1,861st Martian day, or sol, of Spirit's mission on Mars (March 28, 2009). After the drive, the rover took this image with its front hazard-avoidance camera, looking back at the tracks from the drive.

    As usual since losing the use of its right-front wheel in 2006, Spirit drove backwards. The immobile right-front wheel churned up a long stripe of bright soil during this drive. Where Spirit has found such bright soil in the past, subsequent analysis of the composition found concentrations of sulfur or silica that testified to past action of water at the site. When members of the rover team saw the large quantity of bright soil exposed by the Sol 1861 drive, they quickly laid plans to investigate the composition with Spirit's alpha particle X-ray spectrometer.

    The Sol 1861 drive took the rover past the northwest corner of the low plateau called 'Home Plate,' making progress on a route around the western side of Home Plate. The edge of Home Plate forms the horizon on the right side of this image. Husband Hill is on the horizon on the left side. For scale, the parallel rover wheel tracks are about 1 meter (40 inches) apart. The rover's hazard-avoidance cameras take 'fisheye' wide-angle images.

  14. The first World Atlas of the artificial night sky brightness

    NASA Astrophysics Data System (ADS)

    Cinzano, P.; Falchi, F.; Elvidge, C. D.

    2001-12-01

    We present the first World Atlas of the zenith artificial night sky brightness at sea level. Based on radiance-calibrated high-resolution DMSP satellite data and on accurate modelling of light propagation in the atmosphere, it provides a nearly global picture of how mankind is proceeding to envelop itself in a luminous fog. Comparing the Atlas with the United States Department of Energy (DOE) population density data base, we determined the fraction of population who are living under a sky of given brightness. About two-thirds of the World population and 99 per cent of the population in the United States (excluding Alaska and Hawaii) and European Union live in areas where the night sky is above the threshold set for polluted status. Assuming average eye functionality, about one-fifth of the World population, more than two-thirds of the United States population and more than one half of the European Union population have already lost naked eye visibility of the Milky Way. Finally, about one-tenth of the World population, more than 40 per cent of the United States population and one sixth of the European Union population no longer view the heavens with the eye adapted to night vision, because of the sky brightness.

  15. High brightness formamidinium lead bromide perovskite nanocrystal light emitting devices

    PubMed Central

    Perumal, Ajay; Shendre, Sushant; Li, Mingjie; Tay, Yong Kang Eugene; Sharma, Vijay Kumar; Chen, Shi; Wei, Zhanhua; Liu, Qing; Gao, Yuan; Buenconsejo, Pio John S.; Tan, Swee Tiam; Gan, Chee Lip; Xiong, Qihua; Sum, Tze Chien; Demir, Hilmi Volkan

    2016-01-01

    Formamidinium lead halide (FAPbX3) has attracted greater attention and is more prominent recently in photovoltaic devices due to its broad absorption and higher thermal stability in comparison to more popular methylammonium lead halide MAPbX3. Herein, a simple and highly reproducible room temperature synthesis of device grade high quality formamidinium lead bromide CH(NH2)2PbBr3 (FAPbBr3) colloidal nanocrystals (NC) having high photoluminescence quantum efficiency (PLQE) of 55–65% is reported. In addition, we demonstrate high brightness perovskite light emitting device (Pe-LED) with these FAPbBr3 perovskite NC thin film using 2,2′,2″-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) commonly known as TPBi and 4,6-Bis(3,5-di(pyridin-3-yl)phenyl)-2-methylpyrimidine (B3PYMPM) as electron transport layers (ETL). The Pe-LED device with B3PYMPM as ETL has bright electroluminescence of up to 2714 cd/m2, while the Pe-LED device with TPBi as ETL has higher peak luminous efficiency of 6.4 cd/A and peak luminous power efficiency of 5.7 lm/W. To our knowledge this is the first report on high brightness light emitting device based on CH(NH2)2PbBr3 widely known as FAPbBr3 nanocrystals in literature. PMID:27827424

  16. Melanopsin-based brightness discrimination in mice and humans.

    PubMed

    Brown, Timothy M; Tsujimura, Sei-Ichi; Allen, Annette E; Wynne, Jonathan; Bedford, Robert; Vickery, Graham; Vugler, Anthony; Lucas, Robert J

    2012-06-19

    Photoreception in the mammalian retina is not restricted to rods and cones but extends to a small number of intrinsically photoreceptive retinal ganglion cells (ipRGCs), expressing the photopigment melanopsin. ipRGCs are known to support various accessory visual functions including circadian photoentrainment and pupillary reflexes. However, despite anatomical and physiological evidence that they contribute to the thalamocortical visual projection, no aspect of visual discrimination has been shown to rely upon ipRGCs. Based on their currently known roles, we hypothesized that ipRGCs may contribute to distinguishing brightness. This percept is related to an object's luminance-a photometric measure of light intensity relevant for cone photoreceptors. However, the perceived brightness of different sources is not always predicted by their respective luminance. Here, we used parallel behavioral and electrophysiological experiments to first show that melanopsin contributes to brightness discrimination in both retinally degenerate and fully sighted mice. We continued to use comparable paradigms in psychophysical experiments to provide evidence for a similar role in healthy human subjects. These data represent the first direct evidence that an aspect of visual discrimination in normally sighted subjects can be supported by inner retinal photoreceptors.

  17. High brightness formamidinium lead bromide perovskite nanocrystal light emitting devices

    NASA Astrophysics Data System (ADS)

    Perumal, Ajay; Shendre, Sushant; Li, Mingjie; Tay, Yong Kang Eugene; Sharma, Vijay Kumar; Chen, Shi; Wei, Zhanhua; Liu, Qing; Gao, Yuan; Buenconsejo, Pio John S.; Tan, Swee Tiam; Gan, Chee Lip; Xiong, Qihua; Sum, Tze Chien; Demir, Hilmi Volkan

    2016-11-01

    Formamidinium lead halide (FAPbX3) has attracted greater attention and is more prominent recently in photovoltaic devices due to its broad absorption and higher thermal stability in comparison to more popular methylammonium lead halide MAPbX3. Herein, a simple and highly reproducible room temperature synthesis of device grade high quality formamidinium lead bromide CH(NH2)2PbBr3 (FAPbBr3) colloidal nanocrystals (NC) having high photoluminescence quantum efficiency (PLQE) of 55–65% is reported. In addition, we demonstrate high brightness perovskite light emitting device (Pe-LED) with these FAPbBr3 perovskite NC thin film using 2,2‧,2″-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) commonly known as TPBi and 4,6-Bis(3,5-di(pyridin-3-yl)phenyl)-2-methylpyrimidine (B3PYMPM) as electron transport layers (ETL). The Pe-LED device with B3PYMPM as ETL has bright electroluminescence of up to 2714 cd/m2, while the Pe-LED device with TPBi as ETL has higher peak luminous efficiency of 6.4 cd/A and peak luminous power efficiency of 5.7 lm/W. To our knowledge this is the first report on high brightness light emitting device based on CH(NH2)2PbBr3 widely known as FAPbBr3 nanocrystals in literature.

  18. The UV-Bright Stars of Omega Centauri

    NASA Astrophysics Data System (ADS)

    Landsman, Wayne B.

    During the first flight of the ASTRO observatory in 1990 December, we obtained a 1620 A image of the globular cluster Omega Centauri using the Ultraviolet Imaging Telescope (UIT). This image revealed that Omega Cen contained numerous "UV-bright" stars. We subsequently obtained IUE discretionary time to study two UV-bright stars found within 2' of the center of Omega Cen. We found that these stars were insufficiently luminous to be postAGB stars, and suggested that they could be evolved hot horizontal branch stars or postearly AGB stars. We now propose to obtain IUE low-dispersion spectra of four additional UV-bright stars in Omega Cen. Three of the stars (ROA 5342, ROA 5857, and Dickens 3873) are known from comparison of UIT and ground-based photometry to be quite hot (>> 20000 K) although such broad-band photometry can only set a lower limit on their effective temperature. We will use the IUE spectra to determine the effective temperature and luminosity of these stars, in order to help determine their evolutionary status. Our results will yield insights concerning the the late evolution of low mass stars, and may provide clues to the origin of the ultraviolet light in elliptical galaxies.

  19. Recent brightness improvements of 976 nm high power laser bars

    NASA Astrophysics Data System (ADS)

    Bachmann, Alexander; Lauer, Christian; Furitsch, Michael; König, Harald; Müller, Martin; Strauß, Uwe

    2017-02-01

    Pump modules for fiber lasers and fiber-coupled direct diode laser systems require laser diodes with a high beam quality. While in fast axis direction diode lasers exhibit a nearly diffraction limited output beam, the maximum usable output power is usually limited by the slow axis divergence blooming at high power levels. Measures to improve the lateral beam quality are subject of extensive research. Among the many influencing factors are the chip temperature, thermal crosstalk between emitters, thermal lensing, lateral waveguiding and lateral mode structure. We present results on the improvements of the lateral beam divergence and brightness of gain-guided mini-bars for emission at 976 nm. For efficient fiber coupling into a 200 μm fiber with NA 0.22, the upper limit of the lateral beam parameter product is 15.5 mm mrad. Within the last years, the power level at this beam quality has been improved from 44 W to 52 W for the chips in production, enabling more cost efficient pump modules and laser systems. Our work towards further improvements of the beam quality focuses on advanced chip designs featuring reduced thermal lensing and mode shaping. Recent R&D results will be presented, showing a further improvement of the beam quality by 15%. Also, results of a chip design with an improved lateral emitter design for highest brightness levels will be shown, yielding in a record high brightness saturation of 4.8 W/mm mrad.

  20. High brightness negative ion sources with high emission current density

    SciTech Connect

    Vadim Dudnikov

    2002-10-18

    Through the development of Charge Exchange Injection [1] and Surface Plasma Sources (SPS) with Cesium Catalysis [2,3,4,5] the possibility for the accumulation of a high brightness proton beam in circular accelerators was increased greatly, and now it is more than sufficient for all real applications. The combination of the SPS with charge-exchange injection improved large accelerators operation and has permitted beam accumulation up to space-charge limit and overcome this limit several times [6]. The early SPS for accelerators have been in operation without modification for {approx}25 years. in this note an attention is concentrated on the seldom-discussed distinctive features of high brightness beam formation in noiseless regimes of negative ion source operation. Beam quality enhancement up to the level j/T > 1 A/cm{sup 2} eV is possible by optimization of negative ion generation, extraction, and transportation in SPS with cesium catalysis. Advanced version of the SPS for accelerators will be described. Features of negative ion beam formation, transportation, space-charge neutralization-overneutralization, and instability damping will be considered. Practical aspects of SPS operation and high brightness beam production will be discussed.