Sample records for visibility shikai kojo

  1. Visibility Matters

    DEFF Research Database (Denmark)

    Wildgaard, Lorna Elizabeth


    Research production, which earns universities money, is accredited publications in peer-reviewed journals and books. Increasing research productivity is one policy amongst many used by management to boost growth and income. It is time for a pat on the back, the growth of knowledge and visibility...

  2. Japan's healthcare policy for the elderly through the concepts of self-help (Ji-jo), mutual aid (Go-jo), social solidarity care (Kyo-jo), and governmental care (Ko-jo). (United States)

    Sudo, Kyoko; Kobayashi, Jun; Noda, Shinichiro; Fukuda, Yoshiharu; Takahashi, Kenzo


    Elderly care is an emerging global issue threatening both developed and developing countries. The elderly in Japan increased to 26.7% of the population in 2015, and Japan is classified as a super-aged society. In this article, we introduce the financial aspects of the medical care and welfare services policy for the elderly in Japan. Japan's universal health insurance coverage system has been in place since 1961. Long-term care includes welfare services, which were separated from the medical care insurance scheme in 2000 when Japan was already recognized as an aging society. Since then, the percentage of the population over 65 has increased dramatically, with the productive-age population on the decrease. The Japanese government, therefore, is seeking to implement "The Community-based Integrated Care System" with the aim of building comprehensive up-to-the-end-of-life support services in each community. The system has four proposed elements: self-help (Ji-jo), mutual aid (Go-jo), social solidarity care (Kyo-jo), and government care (Ko-jo). From the financial perspective, as the government struggles against the financial burdens of an aging population, they are considering self-help and mutual aid. Based on Japan's present situation, both elements could lead to positive results. The Japanese government must also entrust the responsibility for implementing preventive support to municipalities through strongly required regional autonomy. As Japan has resolved this new challenge through several discussions over a long period of time, other aging countries could learn from the Japanese experience of solving barriers to healthcare policy for the elderly.

  3. Visibly Pushdown Automata

    DEFF Research Database (Denmark)

    Srba, Jiri


    We investigate the possibility of (bi)simulation-like preorder/equivalence checking on the class of visibly pushdown automata and its natural subclasses visibly BPA (Basic Process Algebra) and visibly one-counter automata. We describe generic methods for proving complexity upper and lower bounds...... for a number of studied preorders and equivalences like simulation, completed simulation, ready simulation, 2-nested simulation preorders/equivalences and bisimulation equivalence. Our main results are that all the mentioned equivalences and preorders are EXPTIME-complete on visibly pushdown automata, PSPACE......-complete on visibly one-counter automata and P-complete on visibly BPA. Our PSPACE lower bound for visibly one-counter automata improves also the previously known DP-hardness results for ordinary one-counter automata and one-counter nets. Finally, we study regularity checking problems for visibly pushdown automata...

  4. The Visibility Complex

    NARCIS (Netherlands)

    Pocchiola, Michel; Vegter, Gert


    We introduce the visibility complex of a collection O of n pairwise disjoint convex objects in the plane. This 2–dimensional cell complex may be considered as a generalization of the tangent visibility graph of O. Its space complexity k is proportional to the size of the tangent visibility graph. We

  5. Viewer Makes Radioactivity "Visible" (United States)

    Yin, L. I.


    Battery operated viewer demonstrates feasibility of generating threedimensional visible light simulations of objects that emit X-ray or gamma rays. Ray paths are traced for two pinhold positions to show location of reconstructed image. Images formed by pinholes are converted to intensified visible-light images. Applications range from radioactivity contamination surveys to monitoring radioisotope absorption in tumors.

  6. Visibility and Citation Impact (United States)

    Ebrahim, Nader Ale; Salehi, Hadi; Embi, Mohamed Amin; Tanha, Farid Habibi; Gholizadeh, Hossein; Motahar, Seyed Mohammad


    The number of publications is the first criteria for assessing a researcher output. However, the main measurement for author productivity is the number of citations, and citations are typically related to the paper's visibility. In this paper, the relationship between article visibility and the number of citations is investigated. A case study of…

  7. Visible Human Project (United States)

    ... NLM Mobile Gallery Site Navigation Home The Visible Human Project ® Overview The Visible Human Project ® is an outgrowth of the NLM's 1986 ... dimensional representations of the normal male and female human bodies. Acquisition of transverse CT, MR and cryosection ...

  8. Synthesis of visibility detection systems. (United States)


    Visibility is a critical component to the task of driving on all types of roads. The visibility detection and warning systems provide real-time, automated detection as well as appropriate responses to counteract reduced visibility conditions due to f...

  9. Predicting Visibility of Aircraft (United States)

    Watson, Andrew; Ramirez, Cesar V.; Salud, Ellen


    Visual detection of aircraft by human observers is an important element of aviation safety. To assess and ensure safety, it would be useful to be able to be able to predict the visibility, to a human observer, of an aircraft of specified size, shape, distance, and coloration. Examples include assuring safe separation among aircraft and between aircraft and unmanned vehicles, design of airport control towers, and efforts to enhance or suppress the visibility of military and rescue vehicles. We have recently developed a simple metric of pattern visibility, the Spatial Standard Observer (SSO). In this report we examine whether the SSO can predict visibility of simulated aircraft images. We constructed a set of aircraft images from three-dimensional computer graphic models, and measured the luminance contrast threshold for each image from three human observers. The data were well predicted by the SSO. Finally, we show how to use the SSO to predict visibility range for aircraft of arbitrary size, shape, distance, and coloration. PMID:19462007

  10. Measuring visibility using smartphones (United States)

    Friesen, Jan; Bialon, Raphael; Claßen, Christoph; Graffi, Kalman


    Spatial information on fog density is an important parameter for ecohydrological studies in cloud forests. The Dhofar cloud forest in Southern Oman exhibits a close interaction between the fog, trees, and rainfall. During the three month monsoon season the trees capture substantial amounts of horizontal precipitation from fog which increases net precipitation below the tree canopy. As fog density measurements are scarce, a smartphone app was designed to measure visibility. Different smartphone units use a variety of different parts. It is therefore important to assess the developed visibility measurement across a suite of different smartphones. In this study we tested five smartphones/ tablets (Google/ LG Nexus 5X, Huawei P8 lite, Huawei Y3, HTC Nexus 9, and Samsung Galaxy S4 mini) against digital camera (Sony DLSR-A900) and visual visibility observations. Visibility was assessed from photos using image entropy, from the number of visible targets, and from WiFi signal strength using RSSI. Results show clear relationships between object distance and fog density, yet a considerable spread across the different smartphone/ tablet units is evident.

  11. UVISS preliminary visibility analysis

    DEFF Research Database (Denmark)

    Betto, Maurizio


    The goal of this work is to obtain a preliminary assessment of the sky visibility for anastronomical telescope located on the express pallet of the International SpaceStation (ISS)} taking into account the major constraints imposed on the instrument by the ISSattitude and structure. Part of the w......The goal of this work is to obtain a preliminary assessment of the sky visibility for anastronomical telescope located on the express pallet of the International SpaceStation (ISS)} taking into account the major constraints imposed on the instrument by the ISSattitude and structure. Part...... of the work is also to setup the kernel of a software tool for the visibility analysis thatshould be easily expandable to consider more complex strucures for future activities.This analysis is part of the UVISS assessment study and it is meant to provide elementsfor the definition and the selection...

  12. Between visibility and surveillance

    DEFF Research Database (Denmark)

    Uldam, Julie

    As activists move from alternative media platforms to commercial social media platforms they face increasing challenges in protecting their online security and privacy. While government surveillance of activists is well-documented in both scholarly research and the media, corporate surveillance...... of activists remains under-researched. This presentation explores visibility as a prerequisite and an obstacle to political participation. The dual capacity of visibility in social media enables both surveillance and counter-surveillance by making not only the surveilled actor, but also the surveilling actor......’ surveillance of anti-capitalist activists in social media....

  13. Making Invisible Forces Visible

    DEFF Research Database (Denmark)

    Ratner, Helene; Pors, Justine Grønbæk


    This paper investigates managerial tactics of visualisation when a need to know and manage employees' values and attitudes is expressed. Using the Danish public school as a case study, we explore how school managers use teachers' emotions to render visible presumably invisible information about...... their 'true' attitudes and values. The paper draws on theories of affect as well as actor-network theory to analyse three incidents where managers turn their interpretations of teachers' emotions into such information. These incidents suggest that the efforts to render employees' attitudes and values visible...

  14. The visibility complex

    NARCIS (Netherlands)

    Pocchiola, M; Vegter, G

    We introduce the visibility complex (rr 2-dimensional regular cell complex) of a collection of n pairwise disjoint convex obstacles in the plane. It can be considered as a subdivision of the set of free rays (i.e., rays whose origins lie in free space, the complement of the obstacles). Its cells

  15. Visible Solid State Lasers

    NARCIS (Netherlands)

    Hikmet, R.A.M.


    Diode lasers can be found in various applications most notably in optical communication and optical storage. Visible lasers were until recently were all based on IR diode lasers. Using GaN, directly blue and violet emitting lasers have also been introduced to the market mainly in the area of optical

  16. Visible but Unseen?

    DEFF Research Database (Denmark)

    Torkilsheyggi, Arnvør Martinsdóttir á; Hertzum, Morten


    to support awareness in a setting where the users are (locally) mobile, specifically in regard to information that requires continuous monitoring. We do however also find that the whiteboard safeguarded the work with blood tests against some risks by making blood-test information socially visible....

  17. Evaluation of Visible Plumes. (United States)

    Brennan, Thomas

    Developed for presentation at the 12th Conference on Methods in Air Pollution and Industrial Hygiene Studies, University of Southern California, April, 1971, this outline discusses plumes with contaminants that are visible to the naked eye. Information covers: (1) history of air pollution control regulations, (2) need for methods of evaluating…

  18. Making Heat Visible (United States)

    Goodhew, Julie; Pahl, Sabine; Auburn, Tim; Goodhew, Steve


    Householders play a role in energy conservation through the decisions they make about purchases and installations such as insulation, and through their habitual behavior. The present U.K. study investigated the effect of thermal imaging technology on energy conservation, by measuring the behavioral effect after householders viewed images of heat escaping from or cold air entering their homes. In Study 1 (n = 43), householders who received a thermal image reduced their energy use at a 1-year follow-up, whereas householders who received a carbon footprint audit and a non-intervention control demonstrated no change. In Study 2 (n = 87), householders were nearly 5 times more likely to install draught proofing measures after seeing a thermal image. The effect was especially pronounced for actions that addressed an issue visible in the images. Findings indicate that using thermal imaging to make heat loss visible can promote energy conservation. PMID:26635418

  19. Social media visibility

    DEFF Research Database (Denmark)

    Uldam, Julie


    As activists move from alternative media platforms to commercial social media platforms, they face increasing challenges in protecting their online security and privacy. While government surveillance of activists is well-documented in scholarly research and the media, corporate surveillance...... for responding to the activities of individual activists in social media. It shows that while social media afford an unprecedented level of visibility for activists, it comes with the risk of being monitored by corporations. Theoretically, it draws on conceptions of visibility in social sciences and media...... studies as well as literature on activism and political participation in media studies. Empirically, it draws on files from BP on specific civil society individuals obtained through Subject Access Requests under the UK Data Protection Act 1998 as well as press responses from BP....

  20. On court interpreters' visibility

    DEFF Research Database (Denmark)

    Dubslaff, Friedel; Martinsen, Bodil

    of the service they receive. Ultimately, the findings will be used for training purposes. Future - and, for that matter, already practising - interpreters as well as the professional users of interpreters ought to take the reality of the interpreters' work in practice into account when assessing the quality...... in by the participants almost immediately after the interrogations and supplemented by interviews. The main objective of the project is to explore the interpreters' own perception of the quality of the service they render as well as the professional users´ and the other language users' perception of the quality...... of the interpreter as an invisible language switcher. However, a closer look at the data shows that, even in a less complex constellation like the one analysed here, there is clear evidence of the interpreter's visibility. We shall identify various forms of visibility based on the discourse data...

  1. Visibility graph motifs

    CERN Document Server

    Iacovacci, Jacopo


    Visibility algorithms transform time series into graphs and encode dynamical information in their topology, paving the way for graph-theoretical time series analysis as well as building a bridge between nonlinear dynamics and network science. In this work we introduce and study the concept of visibility graph motifs, smaller substructures that appear with characteristic frequencies. We develop a theory to compute in an exact way the motif profiles associated to general classes of deterministic and stochastic dynamics. We find that this simple property is indeed a highly informative and computationally efficient feature capable to distinguish among different dynamics and robust against noise contamination. We finally confirm that it can be used in practice to perform unsupervised learning, by extracting motif profiles from experimental heart-rate series and being able, accordingly, to disentangle meditative from other relaxation states. Applications of this general theory include the automatic classification a...

  2. Interferometric visibility and coherence (United States)

    Biswas, Tanmoy; García Díaz, María; Winter, Andreas


    Recently, the basic concept of quantum coherence (or superposition) has gained a lot of renewed attention, after Baumgratz et al. (Phys. Rev. Lett. 113, 140401. (doi:10.1103/PhysRevLett.113.140401)), following Åberg (, have proposed a resource theoretic approach to quantify it. This has resulted in a large number of papers and preprints exploring various coherence monotones, and debating possible forms for the resource theory. Here, we take the view that the operational foundation of coherence in a state, be it quantum or otherwise wave mechanical, lies in the observation of interference effects. Our approach here is to consider an idealized multi-path interferometer, with a suitable detector, in such a way that the visibility of the interference pattern provides a quantitative expression of the amount of coherence in a given probe state. We present a general framework of deriving coherence measures from visibility, and demonstrate it by analysing several concrete visibility parameters, recovering some known coherence measures and obtaining some new ones.

  3. Evacuation under limited visibility (United States)

    Frank, Guillermo A.; Dorso, Claudio O.


    A multiplicity of situations can trigger off an evacuation of a room under panic conditions. For "normal" (with "normal" meaning absence of obstacles, perfect visibility, etc.) environmental conditions, the "faster is slower" effect dominates the dynamics of this process. It states that as the pedestrians desire to reach the exit increases, the clogging phenomena delays the time to get out of the room. But, environmental conditions are usually far from "normal." In this work, we consider that pedestrians have to find their way out under low visibility conditions. Some of them might switch to a herding-like behavior if they do not remember where the exit was. Others will just trust on their memory. Our investigation handles the herding and memory effects on the evacuation of a single exit room with no obstacles. We also include a section on how signaling devices affect the evacuation process. Unexpectedly, some low visibility situations may enhance the evacuation performance. This can be resumed as a second paradoxical result, since we demonstrated in an earlier investigation that "clever is not always better" G. A. Frank and C. O. Dorso, Physica A 390, 2135 (2011).

  4. Paradoxes of Visibility

    Directory of Open Access Journals (Sweden)

    Tarnay László


    Full Text Available The paper investigates two possible critical arguments following the pictorial turn. The first is formulated within ocularcentrism, the dominance of sight, and starts with the right to visibility as a general principle that governs today’s digital culture but gets twisted in special cases like the Auschwitz photos of the Shoa, the Abu Ghraib prison videos, or recently the website called Yolocaust. The second is conceived outside the visual culture and is meant to vindicate the other senses vis-à-vis the eyes. However, the argument is truncated here only to highlight the boomerang effect of the other senses: haptic vision. It is the case of visual perception when (a there is a lack of things to see and (b indeterminate synaesthesia: when vision intensifies the other senses in the embodied viewer. The two arguments converge upon a dialectic of the visible and the imaginable, which is formulated here as two paradoxes that the discussed examples transcend. By enforcing visibility at all costs where there is hardly anything recognizable to see, they lead to two diverging results. On the one hand, the meaning of “image” is extended toward the unimaginable, the traumatic experience, on the other hand, it is extended toward the invisible, the encounter with the radical Other.

  5. The visible ear simulator

    DEFF Research Database (Denmark)

    Sorensen, Mads Solvsten; Mosegaard, Jesper; Mikkelsen, Peter Trier


    material.Virtual training often requires the purchase of a program, a customized computer, and expensive peripherals dedicated exclusively to this purpose. MATERIALS AND METHODS: The Visible Ear freeware library of digital images from a fresh-frozen human temporal bone was segmented, and real-time volume......, 2D, or optional anaglyph stereoscopic 3D was achieved on a standard Core 2 Duo personal computer with a GeForce 8,800 GTX graphics card, and surgical interaction was provided through a relatively inexpensive (approximately $2,500) Phantom Omni haptic 3D pointing device. CONCLUSION: This prototype...

  6. WWW visibility in marketing


    Ollila, T.


    Social media is a vital channel for marketers nowadays. Customers are more empowered today than ever before and the Internet is accelerating the trend toward greater customer empowerment. In few years Web 2.0 has become a highly important media and it has changed the Web into platform where individuals can communicate, assemble and organize data. Web 2.0 also offers a variety of different “tools” for companies to be used in marketing. Because companies and products are visible and discussed i...

  7. ATST visible broadband imager (United States)

    McBride, William R.; Wöger, Friedrich; Hegwer, Steve L.; Ferayorni, Andrew; Gregory, B. Scott


    The Advanced Technology Solar Telescope (ATST) is a 4 meter class telescope for observation of the solar atmosphere currently in the construction phase. The Visible Broadband Imager (VBI) is a diffraction limited imaging instrument planned to be the first-light instrument in the ATST instrumentation suite. The VBI is composed of two branches, the "VBI blue" and the "VBI red", and uses state-of-the-art narrow bandwidth interference filters and two custom designed high speed filter wheels to take bursts of images that will be re-constructed using a Graphics Processing Unit (GPU) optimized near-real-time speckle image reconstruction engine. At first light, the VBI instrument will produce diffraction-limited movies of solar activity at eight discrete wavelengths with a field of view of 2 arc minutes square. In this contribution, the VBI design team will discuss the capabilities of the VBI and describe the design of the instrument, highlighting the unique challenges faced in the development of this unique instrument.


    NARCIS (Netherlands)



    An algorithm is presented to maintain the visibility graph of a set of N line segments in the plane in O(log2 N + K log N) time, where K is the total number of arcs of the visibility graph that are destroyed or created upon insertion or deletion of a line segment. The line segments should be

  9. Revisiting visibility in the plane

    DEFF Research Database (Denmark)

    Wilkinson, Bryan Thomas

    Abstract We consider two closely related problems: computing the region visible from a point amid simple polygonal obstacles and computing the lower envelope of a set of disjoint segments. Visibility problems such as these were proposed and promptly solved in the late'80s and early'90s before...

  10. Non-Euclidean visibility problems

    Indian Academy of Sciences (India)

    We prove a visibility criterion and study orchard problem and the cardinality of visible points in large circles. Author Affiliations. Fernando Chamizo1. Departamento de Matemáticas, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain. Dates. Manuscript received: 14 November 2005. Proceedings ...

  11. Visible Jovian Aurora (United States)


    Jupiter's aurora on the night side of the planet is seen here at five different wavelengths. Jupiter's bright crescent, which is about half illuminated, is out of view to the right. North is at the top. The images are centered at 57 degrees north and 184 degrees West and were taken on April 2, 1997 at a range of 1.7 million kilometers (1.05 million miles) by the Solid State Imaging (SSI) camera system aboard NASA's Galileo spacecraft.Although Jupiter's aurora had been imaged from Earth in the ultraviolet and infrared, these are the first images at visible wavelengths, where most of the emission takes place. CLR stands for clear (no filter) and shows the integrated brightness at all wavelengths. The other panels show the violet, green, red, and 889 nanometer-wavelength filtered images. The brightness of the aurora is roughly independent of wavelength, at least at the spectral resolution obtainable with these filters.As on Earth, the aurora is caused by electrically charged particles striking the upper atmosphere, causing the molecules of the atmosphere to glow. The brightness in the different filters contains information about the energy of the impinging particles and the composition of the upper atmosphere. If atomic hydrogen were the only emitter, the light would be much stronger in the red filter, which is not consistent with the observed distribution.The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at: Background information and educational context for the images can be found at: http:/ /

  12. On characterizing terrain visibility graphs

    Directory of Open Access Journals (Sweden)

    William Evans


    Full Text Available A terrain is an $x$-monotone polygonal line in the $xy$-plane. Two vertices of a terrain are mutually visible if and only if there is no terrain vertex on or above the open line segment connecting them. A graph whose vertices represent terrain vertices and whose edges represent mutually visible pairs of terrain vertices is called a terrain visibility graph. We would like to find properties that are both necessary and sufficient for a graph to be a terrain visibility graph; that is, we would like to characterize terrain visibility graphs.Abello et al. [Discrete and Computational Geometry, 14(3:331--358, 1995] showed that all terrain visibility graphs are “persistent”. They showed that the visibility information of a terrain point set implies some ordering requirements on the slopes of the lines connecting pairs of points in any realization, and as a step towards showing sufficiency, they proved that for any persistent graph $M$ there is a total order on the slopes of the (pseudo lines in a generalized configuration of points whose visibility graph is $M$.We give a much simpler proof of this result by establishing an orientation to every triple of vertices, reflecting some slope ordering requirements that are consistent with $M$ being the visibility graph, and prove that these requirements form a partial order. We give a faster algorithm to construct a total order on the slopes. Our approach attempts to clarify the implications of the graph theoretic properties on the ordering of the slopes, and may be interpreted as defining properties on an underlying oriented matroid that we show is a restricted type of $3$-signotope.

  13. Incremental Visualizer for Visible Objects

    DEFF Research Database (Denmark)

    Bukauskas, Linas; Bøhlen, Michael Hanspeter

    path. IVVO is the novel solution which allows data to be visualized and loaded on the fly from the database and which regards visibilities of objects. We run a set of experiments to convince that IVVO is feasible in terms of I/O operations and CPU load. We consider the example of data which uses......This paper discusses the integration of database back-end and visualizer front-end into a one tightly coupled system. The main aim which we achieve is to reduce the data pipeline from database to visualization by using incremental data extraction of visible objects in a fly-through scenarios. We...... also argue that passing only relevant data from the database will substantially reduce the overall load of the visualization system. We propose the system Incremental Visualizer for Visible Objects (IVVO) which considers visible objects and enables incremental visualization along the observer movement...

  14. vysmaw: Fast visibility stream muncher (United States)

    Pokorny, Martin; Law, Casey J.


    The vysmaw client library facilitates the development of code for processes to tap into the fast visibility stream on the National Radio Astronomy Observatory's Very Large Array correlator back-end InfiniBand network.

  15. Visible neutrino decay at DUNE

    Energy Technology Data Exchange (ETDEWEB)

    Coloma, Pilar [Fermilab; Peres, Orlando G. [ICTP, Trieste


    If the heaviest neutrino mass eigenstate is unstable, its decay modes could include lighter neutrino eigenstates. In this case part of the decay products could be visible, as they would interact at neutrino detectors via mixing. At neutrino oscillation experiments, a characteristic signature of such \\emph{visible neutrino decay} would be an apparent excess of events at low energies. We focus on a simple phenomenological model in which the heaviest neutrino decays as $\

  16. Computing Visible-Surface Representations, (United States)


    of applications. @ Massachusetts Institute of Technology 1985 "’ki report dcs;crihrs rccarch done at the Arificial lInelligence lhaboratory of the...411FO111 OIMMI bm tpal) IS. SUPPLEMENTARY MOTES None A IS~~~1. KEY WORS (Co~me 01 reerseea ............ MIngUfy ySek It Vision Variational principles...perception of visible surfaces. The explicit representation of visible surfaces, an intermediate goal of computational vision , has since attracted

  17. Visibility of natural tertiary rainbows. (United States)

    Lee, Raymond L; Laven, Philip


    Naturally occurring tertiary rainbows are extraordinarily rare and only a handful of reliable sightings and photographs have been published. Indeed, tertiaries are sometimes assumed to be inherently invisible because of sun glare and strong forward scattering by raindrops. To analyze the natural tertiary's visibility, we use Lorenz-Mie theory, the Debye series, and a modified geometrical optics model (including both interference and nonspherical drops) to calculate the tertiary's (1) chromaticity gamuts, (2) luminance contrasts, and (3) color contrasts as seen against dark cloud backgrounds. Results from each model show that natural tertiaries are just visible for some unusual combinations of lighting conditions and raindrop size distributions.

  18. Visibility Management and the Body (United States)

    Lasser, Jon; Wicker, Nichole


    The authors employed grounded theory to explore the high school experiences of gay, lesbian, and bisexual students in Central Texas. The central phenomenon that emerged from the study was Visibility Management, or decisions made regarding the disclosure of invisible traits. This article reviews the results of this research with an emphasis on the…

  19. Early Learning Theories Made Visible (United States)

    Beloglovsky, Miriam; Daly, Lisa


    Go beyond reading about early learning theories and see what they look like in action in modern programs and teacher practices. With classroom vignettes and colorful photographs, this book makes the works of Jean Piaget, Erik Erikson, Lev Vygotsky, Abraham Maslow, John Dewey, Howard Gardner, and Louise Derman-Sparks visible, accessible, and easier…

  20. Visible fluorescent proteins for FRET

    NARCIS (Netherlands)

    Kremers, G.J.; Goedhart, J.; Gadella, T.W.J.


    This chapter discusses the use of Visible fluorescent proteins (VFPs) for FRET studies, a comprehensive table with Förster radii of VFP pairs is presented and recommendations for choosing the right pairs are made. The chapter discusses VFPs that are used for studies that use fluorescence resonance

  1. Ultraviolet, Visible, and Fluorescence Spectroscopy (United States)

    Penner, Michael H.

    Spectroscopy in the ultraviolet-visible (UV-Vis) range is one of the most commonly encountered laboratory techniques in food analysis. Diverse examples, such as the quantification of macrocomponents (total carbohydrate by the phenol-sulfuric acid method), quantification of microcomponents, (thiamin by the thiochrome fluorometric procedure), estimates of rancidity (lipid oxidation status by the thiobarbituric acid test), and surveillance testing (enzyme-linked immunoassays), are presented in this text. In each of these cases, the analytical signal for which the assay is based is either the emission or absorption of radiation in the UV-Vis range. This signal may be inherent in the analyte, such as the absorbance of radiation in the visible range by pigments, or a result of a chemical reaction involving the analyte, such as the colorimetric copper-based Lowry method for the analysis of soluble protein.

  2. Book Review: Making Thinking Visible


    ROYAL, KENNETH; Hardie, Lizette


    Recent trends in medical education emphasize the importance of producing well-rounded graduates who not only possess a sufficient fund of medical knowledge but who can think clearly and deeply. Unfortunately, many medical educators struggle with what exactly it means to ?think? and do not know where to begin when asked to teach ?thinking.? We believe the book Making Thinking Visible, though written for K-12, will be of great interest to medical educators. The book describes different types of...

  3. Visibility of halos and rainbows. (United States)

    Gedzelman, S D


    A theory for the visibility of halos and rainbows is presented. The light reaching the observer's eye from the direction of the halo or rainbow is assumed to consist of two parts: (1) a beam of singly scattered sunlight (or moonlight) from a cloud of ice crystals or a rainswath, which, in turn, has suffered depletion by scattering or absorption in its passage to the observer, and (2) the general background brightness. The model is able to account for several long-known qualitative observations concerning halos, namely, that the brightest halos are produced by optically thin cirrostratus clouds (i.e., for which the cloud optical depth tau(c), rainbow the brightness of the beam increases monotonically with the optical depth tau(R) of the sunlit part of the rainswath, but the increase is quite small for tau(R) >/=1. On the other hand, the brightness of the background increases more rapidly with tau(R) for tau(R)> 1 so that the rainbow appears most easily visible for tau(R) less, similar1. This implies that the most easily visible rainbows are produced by light or moderate showers rather than heavy downpours. Finally, suggestions are made for applying the theory to other atmospheric optical phenomena, such as coronas and glories.

  4. Beyond Language Equivalence on Visibly Pushdown Automata

    DEFF Research Database (Denmark)

    Srba, Jiri


    We study (bi)simulation-like preorder/equivalence checking on the class of visibly pushdown automata and its natural subclasses visibly BPA (Basic Process Algebra) and visibly one-counter automata. We describe generic methods for proving complexity upper and lower bounds for a number of studied...... preorders and equivalences like simulation, completed simulation, ready simulation, 2-nested simulation preorders/equivalences and bisimulation equivalence. Our main results are that all the mentioned equivalences and preorders are EXPTIME-complete on visibly pushdown automata, PSPACE-complete on visibly...... one-counter automata and P-complete on visibly BPA. Our PSPACE lower bound for visibly one-counter automata improves also the previously known DP-hardness results for ordinary one-counter automata and one-counter nets. Finally, we study regularity checking problems for visibly pushdown automata...

  5. Visibility and invisibility in chronic illness

    NARCIS (Netherlands)

    Hoppe, S.


    Does the visibility of a condition necessarily lead to stigmatization? Is it easier to suffer from an invisible than a visible condition? And what are the consequences of living with an invisible or visible illness? In this article the author draws on the concepts of stigma and concealability to

  6. Visible spectrum of stable sonoluminescence (United States)

    Carlson, Joseph T.


    Synchronous emissions of picosecond pulses of light are observed to originate from a bubble trapped at the pressure antinode of a resonant sound field. The spectrum has been measured using a single slit spectrometer equipped with a linear array CCD detector. Spectra from differing solutions of water and glycerin are compared to the visible blackbody spectrum distribution. Assuming a blackbody model, apparent temperatures of 18,900 Kelvins are observed in pure water. Increasing glycerin concentration appears to correlate with cooler blackbody temperatures. The spectrum is also found to continually change with time, independent of input parameters.

  7. Book Review: Making Thinking Visible


    Kenneth Royal; Lizette Hardie


    Recent trends in medical education emphasize the importance of producing well-rounded graduates who not only possess a sufficient fund of medical knowledge but who can think clearly and deeply. Unfortunately, many medical educators struggle with what exactly it means to “think” and do not know where to begin when asked to teach “thinking.” We believe the book Making Thinking Visible, though written for K-12, will be of great interest to medical educators. The book describes different types of...

  8. Book Review: Making Thinking Visible

    Directory of Open Access Journals (Sweden)

    Kenneth Royal


    Full Text Available Recent trends in medical education emphasize the importance of producing well-rounded graduates who not only possess a sufficient fund of medical knowledge but who can think clearly and deeply. Unfortunately, many medical educators struggle with what exactly it means to “think” and do not know where to begin when asked to teach “thinking.” We believe the book Making Thinking Visible, though written for K-12, will be of great interest to medical educators. The book describes different types of thinking and presents more than 20 teaching routines that can help engage learners and improve learning to think.

  9. Book Review: Making Thinking Visible (United States)

    Royal, Kenneth; Hardie, Lizette


    Recent trends in medical education emphasize the importance of producing well-rounded graduates who not only possess a sufficient fund of medical knowledge but who can think clearly and deeply. Unfortunately, many medical educators struggle with what exactly it means to “think” and do not know where to begin when asked to teach “thinking.” We believe the book Making Thinking Visible, though written for K-12, will be of great interest to medical educators. The book describes different types of thinking and presents more than 20 teaching routines that can help engage learners and improve learning to think.

  10. JPEG ringing artifact visibility evaluation (United States)

    Hu, Sirui; Pizlo, Zygmunt; Allebach, Jan P.


    To achieve high perceptual quality of compressed images, many objective image quality metrics for compression artifacts evaluation and reduction have been developed based on characterization of local image features. However, it is the end user who is judging the image quality in various applications, so the validation of how well these metrics predict human perception is important and necessary. In this paper, we present a preliminary psychophysics experiment method to capture human perception of local ringing artifacts in JPEG images with different severity levels. Observers are asked to annotate the compressed image where they perceive artifacts along the edges, directly on the screen using an interactive tablet display. They are asked to catalog the severity of artifacts into one of the three levels: Strong, Medium, and Light. We process the hand-marked data into a ringing visibility edge map showing a ringing severity mean opinion score (MOS) at every edge pixel. The perceptual information captured in this experiment, enables us to study the correlation between human perception and local image features, which is an important step towards the goal of developing a non-reference (NR) objective metric to predict the visibility of JPEG ringing artifacts in alignment with the assessments of human observers.

  11. Cloned animal and transgenics; Kuron gijutsu to dobutsu kojo

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, S. [National Inst. of Animal Industry, Ibaraki (Japan)


    Somatic cell cloning technologies are explained, and their use in the manufacture of biologically active substances such as pharmaceuticals is described. In general a cloning technology means a technology of nucleus transfer in which the nucleus of an ovum is removed and the nucleus of another cell is transferred. Since a mammalian ovum is but 100-150{mu}m in diameter, the removal or transfer of a nucleus has to be performed under an inverted microscope provided with a micromanipulator. In 1986, this method was employed for the transfer of a cell nucleus at its early division stage in a sheep embryo, and a sheep was cloned. The production of useful substances such as pharmaceuticals is performed through gene recombination for coli bacteria, yeast fungi, and cultured mammalian cells, but there are some problems to be solved about the amount produced, cost of production, biological activity, etc. Under such circumstances, a concept of animal factory has been invented in which Tg (transgenic) animals themselves are utilized as bioreactors, and several venture organizations have already been incorporated. 3 refs., 1 fig., 1 tab.

  12. Rendering Visible: Painting and Sexuate Subjectivity (United States)

    Daley, Linda


    In this essay, I examine Luce Irigaray's aesthetic of sexual difference, which she develops by extrapolating from Paul Klee's idea that the role of painting is to render the non-visible rather than represent the visible. This idea is the premise of her analyses of phenomenology and psychoanalysis and their respective contributions to understanding…

  13. Generation of correlated UV and visible rainbows. (United States)

    Wu, Guang; Li, Wenxue; Wu, E; Zeng, Heping


    We demonstrate concurrent frequency up-conversion and down-conversion in a quadratic nonlinear medium for the generation of correlated ultraviolet and visible rainbows with one-to-one angular and spectral correspondence, facilitating generation of continuously tunable and photon-momentum-dependent multi-wavelength UV and visible twin photons.

  14. No-visible-scar cholecystectomy

    Directory of Open Access Journals (Sweden)

    Tadeusz M. Wróblewski


    Full Text Available Introduction: Single incision laparoscopic surgery (SILS is a laparoscopic method providing a good cosmetic effect,but requiring the application of special ports and instruments enabling the surgeon to perform the procedure.We report three-ports cholecystectomy through umbilical and suprapubic incisions performed with typical laparos -copic instruments which calls no-visible-scar cholecystectomy (NVSC.Material and methods: Twenty patients with symptomatic cholelithiasis were qualified for NVSC. Typical CO2 pneumoperitoneumwas done after umbilical skin incision. Two ports of 5 mm were inserted in the maximum externaledges of this incision. After cystic duct and cystic artery dissection the right one was exchanged for a port of 11 mm.The second incision for the 11-mm trocar for the laparoscope was done in the suprapubic median line within the hairarea.Results: Cholecystectomies were performed without any conversion to classical laparoscopic cholecystectomy (LCHor open surgery. They were not technically identical due to the gradual improvement in the access and manipulationof instruments. The time of the intervention ranged from 2 hours during the introduction of the new method to 50 minfor the last procedures. No postoperative complications were observed and all patients were discharged not later thanafter conventional LCH.Conclusions: NVSC is a three-port laparoscopic intervention performed with typical laparoscopic instruments. It ismore convenient for the surgeon than single incision LCH, because the placement of the optic in the suprapubic regiongives more space for the instruments. It also provides a very good cosmetic effect of the intervention. The describedprocedure is easy to learn and in case of technical problems additional ports can be applied (as in typical LCH.

  15. Glasses for seeing beyond visible. (United States)

    Zhang, XiangHua; Bureau, Bruno; Lucas, Pierre; Boussard-Pledel, Catherine; Lucas, Jacques


    Conventional glasses based on oxides have a transparency limited by phonon absorption in the near IR region and have a limited interest for analyzing information located far beyond the visible. The IR spectral domain is nevertheless of prime interest, since it covers fundamental wavelength ranges used for thermal imaging as well as molecular vibrational signatures. Besides spectacular advances in the field of IR detectors, the main significant progresses are related to the development of IR glass optics, such as lenses or IR optical fibres. The field of IR glasses is almost totally dominated by glasses formed from heavy atoms such as the chalcogens S, Se and Te. Their transparency extends up to 12, 16 and 28 microm for sulfide-, selenide- and the new generation of telluride-based glasses, respectively. They cover the atmospheric transparency domains, 3-5 and 8-13 microm, respectively, at which the IR radiation can propagate allowing thermal imaging and night-vision operations through thick layers of atmosphere. The development of new glass compositions will be discussed on the basis of structural consideration with the objective of moulding low-cost lenses for IR cameras used, for instance, in car-driving assistance. Additionally, multimode, single-index, optical fibres operating in the 3 to 12 microm window developed for in situ remote evanescent-wave IR spectroscopy will also be mentioned. The detection of molecular IR signatures is applied to environmental monitoring for investigating the pollution of underground water with toxic molecules. The extension of this technique to the investigation of biomolecules in three different studies devoted to liver tissues analysis, bio-film formation, and cell metabolism will also be discussed. Finally we will mention the developments in the field of single-mode fibres operating around 10 mum for the Darwin space mission, which is aiming at discovering, signs of biological life in telluric earth-like exoplanets throughout

  16. Sequential motif profile of natural visibility graphs (United States)

    Iacovacci, Jacopo; Lacasa, Lucas


    The concept of sequential visibility graph motifs—subgraphs appearing with characteristic frequencies in the visibility graphs associated to time series—has been advanced recently along with a theoretical framework to compute analytically the motif profiles associated to horizontal visibility graphs (HVGs). Here we develop a theory to compute the profile of sequential visibility graph motifs in the context of natural visibility graphs (VGs). This theory gives exact results for deterministic aperiodic processes with a smooth invariant density or stochastic processes that fulfill the Markov property and have a continuous marginal distribution. The framework also allows for a linear time numerical estimation in the case of empirical time series. A comparison between the HVG and the VG case (including evaluation of their robustness for short series polluted with measurement noise) is also presented.

  17. A Carpet Cloak Device for Visible Light

    CERN Document Server

    Gharghi, Majid; Zentgraf, Thomas; Liu, Yongmin; Yin, Xiaobo; Valentine, Jason; Zhang, Xiang


    We report an invisibility carpet cloak device, which is capable of making an object undetectable by visible light. The cloak is designed using quasi conformal mapping and is fabricated in a silicon nitride waveguide on a specially developed nano-porous silicon oxide substrate with a very low refractive index. The spatial index variation is realized by etching holes of various sizes in the nitride layer at deep subwavelength scale creating a local effective medium index. The fabricated device demonstrates wideband invisibility throughout the visible spectrum with low loss. This silicon nitride on low index substrate can also be a general scheme for implementation of transformation optical devices at visible frequency.

  18. Target visibility for multiple maneuvering target tracking (United States)

    Sabordo, Madeleine G.; Aboutanios, Elias


    We present a recursion of the probability of target visibility and its applications to analysis of track life and termination in the context of Global Nearest Neighbour (GNN) approach and Probability Hypothesis Density (PHD) filter. In the presence of uncertainties brought about by clutter; decisions to retain a track, terminate it or initialise a new track are based on probability, rather than on distance criterion or estimation error. The visibility concept is introduced into a conventional data-association-oriented multitarget tracker, the GNN; and a random finite set based-tracker, the PHD filter, to take into account instances when targets become invisible or occluded by obstacles. We employ the natural logarithmof the Dynamic Error Spectrum to assess the performance of the trackers with and without probability of visibility incorporated. Simulation results show that the performance of the GNN tracker with visibility concept incorporated is significantly enhanced.

  19. Visibility of noisy point cloud data

    KAUST Repository

    Mehra, Ravish


    We present a robust algorithm for estimating visibility from a given viewpoint for a point set containing concavities, non-uniformly spaced samples, and possibly corrupted with noise. Instead of performing an explicit surface reconstruction for the points set, visibility is computed based on a construction involving convex hull in a dual space, an idea inspired by the work of Katz et al. [26]. We derive theoretical bounds on the behavior of the method in the presence of noise and concavities, and use the derivations to develop a robust visibility estimation algorithm. In addition, computing visibility from a set of adaptively placed viewpoints allows us to generate locally consistent partial reconstructions. Using a graph based approximation algorithm we couple such reconstructions to extract globally consistent reconstructions. We test our method on a variety of 2D and 3D point sets of varying complexity and noise content. © 2010 Elsevier Ltd. All rights reserved.

  20. Visible Light Dye-Sensitized Photosensititve Systems

    National Research Council Canada - National Science Library

    Fang Gao; Yong-yuan Yang


      The visible light dyes were employed to sensitized o-Cl-Hexaarylbiimidazole (o-Cl-HABI). The obtained results suggested that o-Cl-HABI displayed a efficient sensitized photocleavage when exposed to Xenon lamp...

  1. Crisis Management- Operational Logistics & Asset Visibility Technologies

    National Research Council Canada - National Science Library

    Braunbeck, Richard A; Mastria, Michael F


    .... Recent crisis response operations that would have benefited from improved asset visibility include the Indian Ocean tsunami, the Pakistani earthquake, Hurricane Katrina and those related to the Global War on Terror...

  2. Solar Synthesis: Prospects in Visible Light Photocatalysis (United States)

    Schultz, Danielle M.; Yoon, Tehshik P.


    Chemists have long aspired to synthesize molecules the way that plants do — using sunlight to facilitate the construction of complex molecular architectures. Nevertheless, the use of visible light in photochemical synthesis is fundamentally challenging because organic molecules tend not to interact with the wavelengths of visible light that are most strongly emitted in the solar spectrum. Recent research has begun to leverage the ability of visible light absorbing transition metal complexes to catalyze a broad range of synthetically valuable reactions. In this review, we highlight how an understanding of the mechanisms of photocatalytic activation available to these transition metal complexes, and of the general reactivity patterns of the intermediates accessible via visible light photocatalysis, has accelerated the development of this diverse suite of reactions. PMID:24578578

  3. White LED visible light communication technology research (United States)

    Yang, Chao


    Visible light communication is a new type of wireless optical communication technology. White LED to the success of development, the LED lighting technology is facing a new revolution. Because the LED has high sensitivity, modulation, the advantages of good performance, large transmission power, can make it in light transmission light signal at the same time. Use white LED light-emitting characteristics, on the modulation signals to the visible light transmission, can constitute a LED visible light communication system. We built a small visible optical communication system. The system composition and structure has certain value in the field of practical application, and we also research the key technology of transmitters and receivers, the key problem has been resolved. By studying on the optical and LED the characteristics of a high speed modulation driving circuit and a high sensitive receiving circuit was designed. And information transmission through the single chip microcomputer test, a preliminary verification has realized the data transmission function.

  4. The challenge of improving visibility in Beijing

    Directory of Open Access Journals (Sweden)

    Q. H. Zhang


    Full Text Available The "Blue Sky Project" was proposed in 1998 to investigate by how much emissions should be reduced to increase blue sky frequency in Beijing, which hosted the Summer Olympics in 2008. This paper focuses on the temporal variation of visibility and its dependence on meteorological conditions and suspended particles at Beijing using the hourly observed visibility data at Beijing Capital International Airport (BCIA from 1999 to 2007. It has been found that about 47.8% (24.2% of the hours in Beijing are "bad" ("good" hours with visibility below 10 km (equal or higher than 20 km between 1999 and 2007. Due to the high Relative Humidity (RH, summer is the season with the lowest mean visibility in a year. Although PM10 index was reported in a decreasing trend (Chan and Yao, 2008, the increase of RH has resulted in a decreasing trend of visibility over BCIA in the summer from 1999 to 2007. To ensure blue sky ("good" visibility for Olympics 2008, daily mean PM10 index should have been reduced from 81 to 44. This requires that not only vehicle emissions, but also other emissions should be limited. Observations verify that blue-sky-hour rate increased significantly after mean PM10 index was reduced to 53 during Olympics 2008, however, the visibility of 2009 returned to the mean level from 1999 to 2007 during the period 8−24 August. RH (aerosol contribute 24% (76% of the improvement of visibility during August 2008.

  5. Horizon Detection In The Visible Spectrum (United States)


    techniques can also recognize star patterns in star trackers for satellite attitude determination. Horizon detection in the visible spectrum was largely...analysis of visual imagery from low-earth orbit was conducted to develop a horizon brightness transition model, which allows for consistent techniques can also recognize star patterns in star trackers for satellite attitude determination. Horizon detection in the visible spectrum was

  6. Mutagenesis by near-visible light. (United States)

    Kubitschek, H E


    Mutants resistant to bacter iophage T5 were produced both in continuous and in stationary cultures of Escherichia coli by near-visible light, 320 to 400 millimicrons, at rates greatly exceeding spontaneous rates in the ab sence of light. Aerobic mutation rates were about twice anaerobic rates, which shows that mutations were induced in either of at least two different proces ses. Mutations induced by near-visible light involve different photochemical processes than those induced by ul traviolet light.

  7. The absent Rurbano. Media visibility and invisibility


    Cimadevilla, Gustavo; Universidad Nacional de Río Cuarto; Demarchi, Paola; Universidad Nacional de Río Cuarto; Galimberti, Silvina; Universidad Nacional de Río Cuarto


    The work deals with analyzing how the media gives visibility to a social sector that meets your trash tasting existence through the use of chariots and horses in the city of Rio Cuarto. The cart drivers, rag pickers and recyclers, among other names, focus here Rurbano actors. The text shows that particularly the local tv and the press make visible some features over others and paying certain stigmatization. In this regard, we discuss the budgets that support that view and offer different inte...

  8. The Duality of Visibility: Does Visibility Increase or Decrease the Fear of Crime in Schools′ Exterior Environments?

    National Research Council Canada - National Science Library

    Lee, Soyeon; Ha, Mikyoung


    .... Spots where children felt fear in exterior areas of elementary schools were aggregated, and their characteristics were analyzed with two visibility dimensions of visual connectivity with no visible...

  9. The Disappearing Audience and Reflexive Visibility

    Directory of Open Access Journals (Sweden)

    Katerina Girginova


    Full Text Available Contrary to popular opinion and some academic writing that celebrates the renewed visibility of new media audiences, this essay argues that they are increasingly going into retreat. To understand how new media audiences “disappear” from view of one another, I borrow from Brighenti’s typology of visibility and develop the idea of “reflexive visibility.” The latter describes the ability to socially orient ourselves in a digital environment through the textual and contextual cues of others—an activity that is of utmost importance not only to researchers wishing to “see” various audiences but also for audiences writ large, wishing to know themselves.

  10. Query Load Balancing For Visible Object Extraction

    DEFF Research Database (Denmark)

    Bukauskas, Linas; Bøhlen, Michael Hanspeter


    Interactive visual data explorations impose rigid real-time requirements on the extraction of visible objects. Often these requirements are met by deploying powerful hardware that maintains the entire data set in huge main memory structures. In this paper we propose an approach that retrieves the...... point path method minimizes the number of queries by permitting larger query results. The experimental results show that our implementation reduces the number of I/O operations significantly, is stable, and does not depend on the initial number of path points....... the visible data on demand and is based on a tight integration of the database and visualization systems. We propose to incrementally adjust the observer path by adding and dropping path points. The result is an optimal path that minimizes the interaction with the database system and retrieves all visible...

  11. 60 years of UK visibility measurements: impact of meteorology and atmospheric pollutants on visibility (United States)

    Singh, Ajit; Bloss, William J.; Pope, Francis D.


    Reduced visibility is an indicator of poor air quality. Moreover, degradation in visibility can be hazardous to human safety; for example, low visibility can lead to road, rail, sea and air accidents. In this paper, we explore the combined influence of atmospheric aerosol particle and gas characteristics, and meteorology, on long-term visibility. We use visibility data from eight meteorological stations, situated in the UK, which have been running since the 1950s. The site locations include urban, rural and marine environments. Most stations show a long-term trend of increasing visibility, which is indicative of reductions in air pollution, especially in urban areas. Additionally, the visibility at all sites shows a very clear dependence on relative humidity, indicating the importance of aerosol hygroscopicity on the ability of aerosol particles to scatter radiation. The dependence of visibility on other meteorological parameters, such as wind speed and wind direction, is also investigated. Most stations show long-term increases in temperature which can be ascribed to climate change, land-use changes (e.g. urban heat island effects) or a combination of both; the observed effect is greatest in urban areas. The impact of this temperature change upon local relative humidity is discussed. To explain the long-term visibility trends and their dependence on meteorological conditions, the measured data were fitted to a newly developed light-extinction model to generate predictions of historic aerosol and gas scattering and absorbing properties. In general, an excellent fit was achieved between measured and modelled visibility for all eight sites. The model incorporates parameterizations of aerosol hygroscopicity, particle concentration, particle scattering, and particle and gas absorption. This new model should be applicable and is easily transferrable to other data sets worldwide. Hence, historical visibility data can be used to assess trends in aerosol particle

  12. A Carpet Cloak for Visible Light (United States)


    of transformation optical devices at visible frequencies. KEYWORDS:Optical metamaterials , invisibility cloak , transformation optics, nanofabrication...Berkeley, California 94720, United States Invisibility cloaks , a family of optical illusion devices that routeelectromagnetic (EM) waves around an object...EM properties, known as metamaterials ,1,2 have been used to control the propagation of EM waves. Metamaterials have been applied to cloaking using the

  13. Improving the visibility of bicycle infrastructure

    NARCIS (Netherlands)

    Fabriek, E.; De Waard, D.; Schepers, P.


    The visual characteristics of road infrastructure play a major role in a substantial number of single-bicycle crashes. The focus of this research was on finding the most common situations that result in a poorly visible bicycle infrastructure, and investigating how to improve these conditions for

  14. Digital Vigilantism as Weaponisation of Visibility

    NARCIS (Netherlands)

    D. Trottier (Daniel)


    textabstractThis paper considers an emerging practice whereby citizen’s use of ubiquitous and domesticated technologies enable a parallel form of criminal justice. Here, weaponised visibility supersedes police intervention as an appropriate response. Digital vigilantism is a user-led violation of

  15. Making Intercultural Language Learning Visible and Assessable (United States)

    Moloney, Robyn; Harbon, Lesley


    While languages education (Liddicoat, 2002) is being transformed by intercultural language learning theory, there is little illustration of either how students are achieving intercultural learning or how to assess it. This article reports on a study of high school language students in Sydney, Australia. Its findings make visible student…

  16. The Visible Hand of Research Performance Assessment (United States)

    Hamann, Julian


    Far from allowing a governance of universities by the invisible hand of market forces, research performance assessments do not just measure differences in research quality, but yield themselves visible symptoms in terms of a stratification and standardization of disciplines. The article illustrates this with a case study of UK history departments…

  17. Visible Counterterrorism Measures in Urban Spaces

    DEFF Research Database (Denmark)

    Dalgaard-Nielsen, Anja; Laisen, Jesper; Wandorf, Charlotte


    Many scholars working within the tradition of critical studies are sceptical of the presence of visible security measures in urban spaces, arguing that they cause fear and facilitate the political control of citizens. A study carried out in Denmark in 2011 sought to capture, describe, and rank...

  18. Class and Pedagogies: Visible and Invisible. (United States)

    Bernstein, Basil

    This paper defines the "invisible pedagogy," a teaching model used in British infant schools, and discusses its relationship to middle class culture, working class culture, and "visible" pedagogy. The invisible pedagogy is characterized by several features including (1) implicit rather than explicit control over the child by…

  19. Ultraviolet-Visible Spectroscopic Evaluation of Complexation ...

    African Journals Online (AJOL)

    Some complexes of crude methanol extract of Loranthus micranthus Linn parasitic on Kola acuminata were evaluated using ultraviolet-visible absorption spectrophotometry. The crude methanol extract was complexed with ferric chloride solution, borate mixture, methanolic aluminum nitrate and aluminum chloride solutions ...

  20. Training Procedure to Evaluate Visible Emissions. (United States)

    West Virginia Air Pollution Control Commission, Charleston.

    Described in this pamphlet is a procedure used by the West Virginia Air Pollution Control Commission to train personnel in evaluating visible emissions. For this purpose a "Smoke Observer's Training Unit" has been designed, a machine capable of generating both gray/black plumes for training in the use of Ringlemann readings and white plumes for…

  1. Improved low visibility forecasts at Amsterdam Airport (United States)

    Wijngaard, J.; Vogelezang, D.; Maat, N.; van Bruggen, H.


    Accurate, reliable and unambiguous information concerning the actual and expected (low) visibility conditions at Amsterdam Airport Schiphol is very important for the available operational flow capacity. Therefore visibility forecast errors can have a negative impact on safety and operational expenses. KNMI has performed an update of the visibility forecast system in close collaboration with the main users of the forecasts (Air Traffic Control, the airport authorities and KLM airlines). This automatic forecasting system consists of a Numerical Weather Prediction Model (Hirlam) with a statistical post processing module on top of it. Output of both components is supplied to a human forecaster who issues a special probabilistic forecast bulletin. This bulletin is tailored to the specific requirements of the airport community. The improvements made to the forecast system are twofold: 1) In addition to the Meteorological Optical Range (MOR) values, RVR (Runway Visual Range) is forecasted. Since RVR depends on both MOR and the local Background Luminance, a (deterministic) statistical forecast for the latter has been developed. 2) Another improvement was achieved by calculating joint probabilities for specific combinations of visibility and cloud base height for thresholds which have direct impact on the flow capacity at the airport. The development of this new visibility forecast will be presented briefly. Also a few verification results will be shown to demonstrate the improvements made. Finally, the importance of explaining the user the use of the forecast information, in relation to their decision making process, will be discussed. For that reason, a simple guideline model to make a cost-optimal choice will be introduced.

  2. Design for The Indoor Visible Light Communication Application System Based on LED Visible Light

    Directory of Open Access Journals (Sweden)

    Lian Wenyu


    Full Text Available This paper designs an indoor visible light communication application system based on LED. The system can modulate the original signal one or more times, move to a specific frequency band, transmit on the power line, in the LED terminal use this module to decode, restore the Ethernet signals. This design is applicable to the simplicity of the LED visible light communication applications, which provide the premise and guarantee for the construction of smart home network.

  3. Teal Amber Visible Focal Plane Technology (United States)

    Johnson, Charles R.; Burczewski, Ron


    Deep-space surveillance missions have imposed severe demands on existing technology and simulated the search for new, advanced technology developments to provide higher performance. Defense Advanced Research Projects Agency (DARPA) sponsored Teal Amber as a visible charge-coupled device (CCD) and associated focal plane signal processing technology development and demonstration program. This paper describes this large-scale, staring-array-sensor concept. The current state of art in the resulting visibled CCD imagers is specified, along with the focal plane signal processor implementation in low power-weight-volume large-scale integrated (LSI) circuitry. Performance requirements and analytic predictions are compared to demonstration system results from an electro-optical test site in White Sands, New Mexico.

  4. Digital/Commercial (In)visibility

    DEFF Research Database (Denmark)

    Leander, Anna


    This article explores one aspect of digital politics, the politics of videos and more spe- cifically of DAESH recruitment videos. It proposes a practice theoretical approach to the politics of DAESH recruitment videos focused on the re-production of regimes of (in)visibility. The article develops...... an argument demonstrating specifically how digital and commercial logics characterize the aesthetic, circulatory, and infrastructuring practices re-producing the regime of (in)visibility. It shows that digital/commercial logics are at the heart of the combinatorial marketing of multiple, contradictory images...... of the DAESH polity in the videos; that they are core to the participatory, entrepreneurial, individua- lized and affective processes of contagion determining whom the videos reach and involve; and that they shape the sorting, linking, flagging and censoring of the videos that define their accessibility...

  5. High efficiency dielectric metasurfaces at visible wavelengths

    CERN Document Server

    Devlin, Robert C; Chen, Wei-Ting; Oh, Jaewon; Capasso, Federico


    Metasurfaces are planar optical elements that hold promise for overcoming the limitations of refractive and conventional diffractive optics1-3. Dielectric metasurfaces demonstrated thus far4-10 are limited to transparency windows at infrared wavelengths because of significant optical absorption and loss at visible wavelengths. It is critical that new materials and fabrication techniques be developed for dielectric metasurfaces at visible wavelengths to enable applications such as three-dimensional displays, wearable optics and planar optical systems11. Here, we demonstrate high performance titanium dioxide dielectric metasurfaces in the form of holograms for red, green and blue wavelengths with record absolute efficiency (>78%). We use atomic layer deposition of amorphous titanium dioxide that exhibits low surface roughness of 0.738 nm and ideal optical properties. To fabricate the metasurfaces we use a lift-off-like process that allows us to produce highly anisotropic nanofins with shape birefringence. This ...

  6. Transformational leadership: visibility, accessibility, and communication. (United States)

    Clavelle, Joanne T


    The chief nursing officer of a Magnet® organization is a dynamic, transformational leader who develops and communicates a strong vision for nursing excellence and creates a foundation for exemplary nursing practice and excellent patient care. Transformational leadership is a core component of the Magnet Model®. The 3rd subcomponent--visibility, accessibility, and communication--is the focus of this article.

  7. Efficient Computations and Representations of Visible Surfaces. (United States)


    AS. HSTT NS F EH CABIDEF/ /EFFICIENT COMUTATIONS AND REPRESENTATIONS OF VISIBLE SURFACES. (U) DEC 79 W RICHARDS, X A STEVENS AFOSR79-0020...alone. Although such a solution is not computational optimal, it may be very practical for most natural scenes. UNCLASSIFIED SECURITY contrast or chromatic content. This reduction can be determined- locally from image information alone. Although such a solution is not

  8. Compression of space for low visibility probes

    Directory of Open Access Journals (Sweden)

    Sabine eBorn


    Full Text Available Stimuli briefly flashed just before a saccade are perceived closer to the saccade target, a phenomenon known as perisaccadic compression of space (Ross, Morrone, & Burr, 1997. More recently, we have demonstrated that brief probes are attracted towards a visual reference when followed by a mask, even in the absence of saccades (Zimmermann, Born, Fink, & Cavanagh, 2014. Here, we ask whether spatial compression depends on the transient disruptions of the visual input stream caused by either a mask or a saccade. Both of these degrade the probe visibility but we show that low probe visibility alone causes compression in the absence of any disruption. In a first experiment, we varied the regions of the screen covered by a transient mask, including areas where no stimulus was presented and a condition without masking. In all conditions, we adjusted probe contrast to make the probe equally hard to detect. Compression effects were found in all conditions. To obtain compression without a mask, the probe had to be presented at much lower contrasts than with masking. Comparing mislocalizations at different probe detection rates across masking, saccades and low contrast conditions without mask or saccade, Experiment 2 confirmed this observation and showed a strong influence of probe contrast on compression. Finally, in Experiment 3, we found that compression decreased as probe duration increased both for masks and saccades although here we did find some evidence that factors other than simply visibility as we measured it contribute to compression. Our experiments suggest that compression reflects how the visual system localizes weak targets in the context of highly visible stimuli.

  9. Compression of Space for Low Visibility Probes. (United States)

    Born, Sabine; Krüger, Hannah M; Zimmermann, Eckart; Cavanagh, Patrick


    Stimuli briefly flashed just before a saccade are perceived closer to the saccade target, a phenomenon known as perisaccadic compression of space (Ross et al., 1997). More recently, we have demonstrated that brief probes are attracted towards a visual reference when followed by a mask, even in the absence of saccades (Zimmermann et al., 2014a). Here, we ask whether spatial compression depends on the transient disruptions of the visual input stream caused by either a mask or a saccade. Both of these degrade the probe visibility but we show that low probe visibility alone causes compression in the absence of any disruption. In a first experiment, we varied the regions of the screen covered by a transient mask, including areas where no stimulus was presented and a condition without masking. In all conditions, we adjusted probe contrast to make the probe equally hard to detect. Compression effects were found in all conditions. To obtain compression without a mask, the probe had to be presented at much lower contrasts than with masking. Comparing mislocalizations at different probe detection rates across masking, saccades and low contrast conditions without mask or saccade, Experiment 2 confirmed this observation and showed a strong influence of probe contrast on compression. Finally, in Experiment 3, we found that compression decreased as probe duration increased both for masks and saccades although here we did find some evidence that factors other than simply visibility as we measured it contribute to compression. Our experiments suggest that compression reflects how the visual system localizes weak targets in the context of highly visible stimuli.


    Directory of Open Access Journals (Sweden)

    Y. Zhai


    Full Text Available Images captured in foggy weather conditions often suffer from poor visibility, which will create a lot of impacts on the outdoor computer vision systems, such as video surveillance, intelligent transportation assistance system, remote sensing space cameras and so on. In this paper, we propose a new transmission estimated method to improve the visibility of single input image (with fog or haze, as well as the image’s details. Our approach stems from two important statistical observations about haze-free images and the haze itself. First, the famous dark channel prior, a statistics of the haze-free outdoor images, can be used to estimate the thickness of the haze; and second, gradient prior law of transmission maps, which is based on dark channel prior. By integrating these two priors, to estimate the unknown scene transmission map is modeled into a TV-regularization optimization problem. The experimental results show that the proposed approach can effectively improve the visibility and keep the details of fog degraded images in the meanwhile.

  11. Visibly ethnically different families in Denmark & Sweden

    DEFF Research Database (Denmark)

    Singla, Rashmi

    This paper foregounds visibly ethnically different families (Phoenix, 2011) in Denmark. These comprise both.families with parents from two different countries (India and Denmark) and families with transnational adoptees (South Korea). The former are barely scientifically explored due to the domin......This paper foregounds visibly ethnically different families (Phoenix, 2011) in Denmark. These comprise both.families with parents from two different countries (India and Denmark) and families with transnational adoptees (South Korea). The former are barely scientifically explored due...... and poststructuralism in the latter. The results indicate both the possibilities and the limitations involved, highlighting the internal - intersubjective experiences, and the external aspects - the structural factors, other(s) gaze towards the visible differences. Furthermore some parental experiences in transmitting...... racial literacy- identifying racism as a serious problem and preparing children to cope are seen. For the transnational adoptees, inclusion as Danish implies exclusion from categories such as Korean. Also anxiety from the adoptive family regarding exclusion/alienation entails ambivalences and paradoxes...

  12. Photodetector Characteristics in Visible Light Communication

    KAUST Repository

    Ho, Kang-Ting


    Typically, in the semiconductor industry pn heterojunctions have been used as either light-emitting diodes (LED) or photodiodes by applying forward current bias or reverse voltage bias, respectively. However, since both devices use the same structure, the light emitting and detecting properties could be combine in one single device, namely LED-based photodetector. Therefore, by integrating LED-based photodetectors as either transmitter or receiver, optical wireless communication could be easily implemented for bidirectional visible light communication networks at low-cost. Therefore, this dissertation focus on the investigation of the photodetection characteristics of InGaN LED-based photodetectors for visible light communication in the blue region. In this regard, we obtain external quantum efficiency of 10 % and photoresponse rise time of 71 μs at 405-nm illumination, revealing high-performance photodetection characteristics. Furthermore, we use orthogonal frequency division multiplexing quadrature amplitude modulation codification scheme to enlarge the operational bandwidth. Consequently, the transmission rate of the communication is efficiently enhanced up to 420 Mbit/s in visible light communication.

  13. Evaluating the visibility of presentation slides (United States)

    Sugawara, Genki; Umezu, Nobuyuki


    Presentations using slide software such as PowerPoint are widely performed in offices and schools. The improvement of presentation skills among ordinary people is required because these days such an opportunity of giving presentation is becoming so common. One of the key factors for making successful presentation is the visibility of the slides, as well as the contents themselves. We propose an algorithm to numerically evaluate the visibility of presentation slides. Our method receives a presentation as a set of images and eliminates the background from the slides to extract characters and figures. This algorithm then evaluates the visibility according to the number and size of characters, their colors, and figure layouts. The slide evaluation criteria are based on the series of experiments with 20 participants to parameterize typical values for visual elements in slides. The algorithm is implemented on an iMac and takes 0.5 sec. to evaluate a slide image. The evaluation score is given as a value between 0 and 100 and the users can improve their slide pages with lower scores. Our future work includes a series of experiments with various presentations and extending our method to publish as a web-based rating service for learning presentation skills.

  14. First Visibility of the Lunar Crescent (United States)

    Caldwell, J. A. R.; Laney, C. D.


    Astronomical observatories are often asked to predict the visibility of the young crescent moon by communities (especially Islamic and Karaite) which use traditional lunar calendars. The SAAO has provided such information for many years, but the early 1990s were a watershed of sorts. Astronomical visibility factors in those years created an unusually severe bias against visibility of the Ramadaan and Shawwall crescents from the southern half of the continent, relative to North Africa and the Mideast (to an extent not seen since the 1860s!). The perplexity caused by the resulting delay in sightings ultimately led to a much greater level of communication between astronomers and the crescent-watching community. The SAAO began collecting, systematizing, and propagating the astronomical information available on the crescent visibility issue, the current results of which are summarized here. Les communauté (spécialement islamiques et karaïtes) qui utilisent les calendriers lunaires traditionnels, demandent souvent aux observatoires astronomiques de prédire le moment oú le croissant de lune naissant devient visible. Depuis de nombreuses années le SAAO fournit cette information, mais les années 1990 furent une sorte de tournant. Dans ces années-là les facteurs de visibilité astronomiques créèrent une déviation exceptionnellement grave par rapport à la visibilité des croissants du Ramadan et du Shawal sur la moitié sud du continent relative à l'Afrique du Nord et au Moyen-Orient (dans une mesure jamais atteinte depuis les années 1860!). La perplexité due au retard qui en résulta dans la vision du nouveau croissant, conduisit finalement à renforcer la communication entre les astronomes et la communauté des observateurs du croissant. Le SAAO commença à collecter, systématiser et diffuser l'information astronomique disponible sur la question de la visibilité du croissant dont nous résumons ici les résultats actuels.

  15. Increasing child pedestrian and cyclist visibility: cluster randomised controlled trial

    National Research Council Canada - National Science Library

    C A Mulvaney; D Kendrick; M C Watson; C A C Coupland


    Study objective: Visibility aids have the potential to reduce child pedestrian and cyclist injury but scarce data exist relating to their use or to interventions for increasing visibility aid use among children...


    National Aeronautics and Space Administration — The TCSP GOES Visible and Infrared Images dataset was collected in support of the Tropical Cloud Systems and Processes (TCSP) mission, visible and infrared imagery...

  17. Visible Light Responsive Catalyst for Air Water Purification Project (United States)

    Wheeler, Raymond M.


    Investigate and develop viable approaches to render the normally UV-activated TIO2 catalyst visible light responsive (VLR) and achieve high and sustaining catalytic activity under the visible region of the solar spectrum.

  18. Efficient visibility-driven medical image visualisation via adaptive binned visibility histogram. (United States)

    Jung, Younhyun; Kim, Jinman; Kumar, Ashnil; Feng, David Dagan; Fulham, Michael


    'Visibility' is a fundamental optical property that represents the observable, by users, proportion of the voxels in a volume during interactive volume rendering. The manipulation of this 'visibility' improves the volume rendering processes; for instance by ensuring the visibility of regions of interest (ROIs) or by guiding the identification of an optimal rendering view-point. The construction of visibility histograms (VHs), which represent the distribution of all the visibility of all voxels in the rendered volume, enables users to explore the volume with real-time feedback about occlusion patterns among spatially related structures during volume rendering manipulations. Volume rendered medical images have been a primary beneficiary of VH given the need to ensure that specific ROIs are visible relative to the surrounding structures, e.g. the visualisation of tumours that may otherwise be occluded by neighbouring structures. VH construction and its subsequent manipulations, however, are computationally expensive due to the histogram binning of the visibilities. This limits the real-time application of VH to medical images that have large intensity ranges and volume dimensions and require a large number of histogram bins. In this study, we introduce an efficient adaptive binned visibility histogram (AB-VH) in which a smaller number of histogram bins are used to represent the visibility distribution of the full VH. We adaptively bin medical images by using a cluster analysis algorithm that groups the voxels according to their intensity similarities into a smaller subset of bins while preserving the distribution of the intensity range of the original images. We increase efficiency by exploiting the parallel computation and multiple render targets (MRT) extension of the modern graphical processing units (GPUs) and this enables efficient computation of the histogram. We show the application of our method to single-modality computed tomography (CT), magnetic resonance

  19. 40 CFR 52.26 - Visibility monitoring strategy. (United States)


    ... ascribed to them in the Clean Air Act, or in the protection of visibility program (40 CFR 51.301), all as... determine both background visibility conditions and reasonably attributable visibility impairment caused by...) teleradiometers, (iv) nephelometers, (v) human observation, or (vi) other appropriate technology. (4) The...

  20. Use of cameras for monitoring visibility impairment (United States)

    Malm, William; Cismoski, Scott; Prenni, Anthony; Peters, Melanie


    Webcams and automated, color photography cameras have been routinely operated in many U.S. national parks and other federal lands as far back as 1988, with a general goal of meeting interpretive needs within the public lands system and communicating effects of haze on scenic vistas to the general public, policy makers, and scientists. Additionally, it would be desirable to extract quantifiable information from these images to document how visibility conditions change over time and space and to further reflect the effects of haze on a scene, in the form of atmospheric extinction, independent of changing lighting conditions due to time of day, year, or cloud cover. Many studies have demonstrated a link between image indexes and visual range or extinction in urban settings where visibility is significantly degraded and where scenes tend to be gray and devoid of color. In relatively clean, clear atmospheric conditions, clouds and lighting conditions can sometimes affect the image radiance field as much or more than the effects of haze. In addition, over the course of many years, cameras have been replaced many times as technology improved or older systems wore out, and therefore camera image pixel density has changed dramatically. It is shown that gradient operators are very sensitive to image resolution while contrast indexes are not. Furthermore, temporal averaging and time of day restrictions allow for developing quantitative relationships between atmospheric extinction and contrast-type indexes even when image resolution has varied over time. Temporal averaging effectively removes the variability of visibility indexes associated with changing cloud cover and weather conditions, and changes in lighting conditions resulting from sun angle effects are best compensated for by restricting averaging to only certain times of the day.

  1. New stratospheric UV/visible radiance measurements

    Directory of Open Access Journals (Sweden)

    F. J. Marceau


    Full Text Available A stratospheric balloon was launched on 12 October 1986 from the "CNES" base at Aire sur l'Adour (France to record twilight radiance in the stratosphere. The near-UV and visible radiances were continuously monitored by a photometer during sunrise. Some observations are presented for different viewing azimuthal planes and viewing elevation angles. They show the influence of aerosols layers and clouds which can be also seen on related photographs. The results as a whole may be used for testing some radiative models, especially for twilight conditions.

  2. Drilling with fiber-transmitted, visible lasers

    Energy Technology Data Exchange (ETDEWEB)

    Kautz, D.D.; Berzins, L.V.; Dragon, E.P.; Werve, M.E.; Warner, B.E.


    High power and radiance copper-vapor laser technology developed at Lawrence Livermore National Laboratory shows great promise for many materials processing tasks. The authors recently transmitted the visible light produced by these lasers through fiber optics to perform hole drilling experiments. They found the tolerances on the hole circulatory and cylindricity to be excellent when compared to that produced by conventional optics. This technique lends itself to many applications that are difficult to perform when using conventional optics, including robotic manipulation and hole drilling in non-symmetric parts.

  3. Macroscopic invisibility cloaking of visible light

    DEFF Research Database (Denmark)

    Chen, Xianzhong; Luo, Y.; Zhang, Jingjing


    invisibility cloaks has been reported at various electromagnetic frequencies. All the invisibility cloaks demonstrated thus far, however, have relied on nano- or micro-fabricated artificial composite materials with spatially varying electromagnetic properties, which limit the size of the cloaked region...... to a few wavelengths. Here, we report the first realization of a macroscopic volumetric invisibility cloak constructed from natural birefringent crystals. The cloak operates at visible frequencies and is capable of hiding, for a specific light polarization, three-dimensional objects of the scale...

  4. New stratospheric UV/visible radiance measurements

    Directory of Open Access Journals (Sweden)

    F. J. Marceau

    Full Text Available A stratospheric balloon was launched on 12 October 1986 from the "CNES" base at Aire sur l'Adour (France to record twilight radiance in the stratosphere. The near-UV and visible radiances were continuously monitored by a photometer during sunrise. Some observations are presented for different viewing azimuthal planes and viewing elevation angles. They show the influence of aerosols layers and clouds which can be also seen on related photographs. The results as a whole may be used for testing some radiative models, especially for twilight conditions.

  5. Visible light communication applications in healthcare. (United States)

    Muhammad, Shoaib; Qasid, Syed Hussain Ahmed; Rehman, Shafia; Rai, Aitzaz Bin Sulltan


    With the development in science, methods of communication are also improved, replacing old ones with new advanced ways in an attempt to make data transfer more secure, safer for health, and time as well as cost efficient. One of such methods is Visible Light Communication, as the name implies data is transferred through a light equipment such as incandescent or florescent bulb having speed of 10 Kb/s or LEDs approaching speed of 500 Mb/s [1]. VLC uses visible light between 384 and 789 THz [2,3]. Though range is limitation of VLC, however data transfer up-to distance of 1 to 2 km although at lower transfer rate has been reached.The VLC system comprises of light source like LED and receiver equipment, however, with advancement, now LEDs are used for both sending and receiving data. LED remains on all the time, and there is no change in brightness level during the whole process, making it safe for eyes. Currently, VLC system is facing some serious technical challenges before it could be applied in daily life.

  6. Advances and prospects in visible light communications (United States)

    Hongda, Chen; Chunhui, Wu; Honglei, Li; Xiongbin, Chen; Zongyu, Gao; Shigang, Cui; Qin, Wang


    Visible light communication (VLC) is an emerging technology in optical wireless communication (OWC) that has attracted worldwide research in recent years. VLC can combine communication and illumination together, which could be applied in many application scenarios such as visible light communication local area networks (VLANs), indoor localization, and intelligent lighting. In recent years, pioneering and significant work have been made in the field of VLC. In this paper, an overview of the recent progress in VLC is presented. We also demonstrate our recent experiment results including bidirectional 100 Mbit/s VLAN or Li-Fi system based on OOK modulation without blue filter. The VLC systems that we proposed are good solutions for high-speed VLC application systems with low-cost and low-complexity. VLC technology shows a bright future due to its inherent advantages, shortage of RF spectra and ever increasing popularity of white LEDs. Project supported by the National High Technology Research and Development Program of China (Nos. 2015AA033303, 2013AA013602, 2013AA013603, 2013AA03A104), the National Natural Science Foundation of China (Nos. 61178051, 61321063, 61335010, 61178048, 61275169), and the National Basic Research Program of China (Nos. 2013CB329205, 2011CBA00608).

  7. Visible and occult microscopic lesions of endometriosis

    Directory of Open Access Journals (Sweden)

    Khaleque Newaz Khan


    Full Text Available Endometriosis is a multifactorial disease mostly affecting women of reproductive age and is associated with chronic pelvic pain and infertility. Even after 300 years, most of the literature claims that pathogenesis and/or pathophysiology of endometriosis is still elusive. Recurrence of pain and lesion continues to occur after effective medical or surgical therapies. Once generated within the pelvis due to retrograde entry of menstrual debris, peritoneal endometriotic lesions time-dependently change their color appearance resulting from certain biochemical change within lesions. A variable pattern of endometriotic lesions within the pelvis can be detected by laparoscopy as visible peritoneal endometriosis. It is generally believed that besides ovarian steroid hormones, the growth of endometriosis can be regulated by the innate immune system in the pelvic microenvironment by their interaction with endometrial cells and immune cells. Even with the careful eyes of an expert surgeon, we may sometimes miss detecting peritoneal lesion within the peritoneal cavity or deep into the peritoneum. In such a case, random collection of normal peritoneum may carry the possibility to identify some hidden endometriotic lesions by microscopy and these lesions can be named as occult (invisible microscopic endometriosis (OME. Here, we discuss the color appearance of peritoneal lesions and activity of these lesions by analysis of a panel of activity markers. Finally we discuss our recent findings on OME, their biological and clinical significance, and try to make a possible link in the origin between visible endometriosis and OME.

  8. Bright visible light emission from graphene. (United States)

    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; Yoo, Yong Shim; 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


    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.

  9. UV/Visible Telescope with Hubble Disposal (United States)

    Benford, Dominic J.


    Submission Overview: Our primary objective is to convey a sense of the significant advances possible in astrophysics investigations for major Cosmic Origins COR program goals with a 2.4m telescope asset outfitted with one or more advanced UV visible instruments. Several compelling science objectives were identified based on community meetings these science objectives drove the conceptual design of instruments studied by the COR Program Office during July September 2012. This RFI submission encapsulates the results of that study, and suggests that a more detailed look into the instrument suite should be conducted to prove viability and affordability to support the demonstrated scientific value. This study was conducted in the context of a larger effort to consider the options available for a mission to dispose safely of Hubble hence, the overall architecture considered for the mission we studied for the 2.4m telescope asset included resource sharing. This mitigates combined cost and risk and provides naturally for a continued US leadership role in astrophysics with an advanced, general-purpose UV visible space telescope.

  10. Needle tip visibility in 3D ultrasound images (United States)

    Arif, Muhammad; Moelker, Adriaan; van Walsum, Theo


    Needle visibility is of crucial importance for ultrasound guided interventional procedures. However, several factors, such as shadowing by bone or gas and tissue echogenic properties similar to needles, may compromise needle visibility. Additionally, small angle between the ultrasound beam and the needle, as well as small gauged needles may reduce visibility. Variety in needle tips design may also affect needle visibility. Whereas several studies have investigated needle visibility in 2D ultrasound imaging, no data is available for 3D ultrasound imaging, a modality that has great potential for image guidance interventions1. In this study, we evaluated needle visibility using a 3D ultrasound transducer. We examined different needles in a tissue mimicking liver phantom at three angles (200, 550 and 900) and quantify their visibility. The liver phantom was made by 5% polyvinyl alcohol solution containing 1% Silica gel particles to act as ultrasound scattering particles. We used four needles; two biopsy needles (Quick core 14G and 18G), one Ablation needle (Radiofrequency Ablation 17G), and Initial puncture needle (IP needle 17G). The needle visibility was quantified by calculating contrast to noise ratio. The results showed that the visibility for all needles were almost similar at large angles. However the difference in visibility at lower angles is more prominent. Furthermore, the visibility increases with the increase in angle of ultrasound beam with needles.

  11. Visible Lasers and Emerging Color Converters for Lighting and Visible Light Communications

    KAUST Repository

    Shen, Chao


    GaN-based lasers are promising for white lighting and visible-light communication (VLC). The advances of III-nitride photonic integration, and the application of YAG crystal and perovskite-based phosphors to lighting and VLC will be discussed.

  12. Contabilidad, Finanzas Empresariales y Mano Visible

    Directory of Open Access Journals (Sweden)

    Juan José Durán Herrera


    Full Text Available En el ámbito de la Economía y Dirección de la Empresa, la Contabilidad y las Finanzas juegan un papel primordial por cuanto que, prioritariamente, se ocupan de la determinación del valor de la empresa y, respectivamente, de proporcionar y evaluar la información suplementaria necesaria para la formación de expectativas reales sobre el futuro de dicha organización. En la fuerte interdependencia de los programas de investigación de ambas disciplinas -Contabilidad y Finanzas- se entrecruzan los análisis respectivos de la naturaleza de los activos, del gobierno de la empresa como organización y del cálculo de los resultados alcanzados. La investigación contempla los cambios en las circunstancias (instituciones y organizaciones en las que se desarrolla la función financiera y se aplica la contabilidad para medir e informar sobre la realidad de la empresa, evidenciándose el paralelismo, la complementariedad y las diferencias que se producen entre ambas disciplinas. El valor de la empresa como punto de encuentro manifiesta dos aproximaciones: el valor contable basado en datos históricos o en precios corrientes y el valor financiero que estima el valor actualizando los flujos de caja derivados del desarrollo del proyecto empresa. Palabras clave: contabilidad y finanzas empresariales, información contable y decisiones financieras, dirección financiera y contabilidad, mano visible de la empresa. The theory and practice of Accounting and Finance make possible to estimate the value of the firm and, respectively, both provide and evaluate supplementary information that constitudes inputs for the expectations about the nature of organization. The strong interdependence between the researtch programs in both academic disciplines are show in their own analysis about the nature of assets, the governance of the firm and the determination of the profitability of the corporation. The institutional changes influence the research programs of both

  13. Representation and Visibility. Roma in the Media

    Directory of Open Access Journals (Sweden)

    Magdalena Ratajczak


    Full Text Available This article is divided into three main parts. The first is an overview of the situation of the Roma minorities in Slovenia and Poland. The second part of the article presents minority broadcast media and the main elements of the legal and institutional framework they operate in. Finally, this article focuses on the visibility of Roma in the media. This article draws attention to cultural pluralism and how cultural pluralism is implemented by the public service broadcasters in Poland and Slovenia, particularly in the context of the presence of Roma minorities in the media. The research is based on 15 interviews carried out in Slovenia and Poland between 2006-2009 with journalists, editors, researchers, workers of NGOs, government representatives and Roma minority leaders. This study is also based on policy documents, reports of governments, NGOs and international organisations, academic literature and content analysis of Roma minority media.

  14. PAPR analysis for OFDM visible light communication. (United States)

    Wang, Jiaheng; Xu, Yang; Ling, Xintong; Zhang, Rong; Ding, Zhi; Zhao, Chunming


    Orthogonal frequency-division multiplexing (OFDM) is a practical technology in visible light communication (VLC) for high-speed transmissions. However, one of its operational limitations is the peak-to-average power ratio (PAPR) of the transmitted signal. In this paper, we analyze the PAPR distributions of four VLC OFDM schemes, namely DC-biased optical OFDM (DCO-OFDM), asymmetrically clipped optical OFDM (ACO-OFDM), pulse amplitude modulated discrete multitone (PAM-DMT), and Flip-OFDM. Both lower and upper clippings are considered. We analytically derive the complementary cumulative distribution functions (CCDFs) of the PAPRs of the clipped VLC OFDM signals, and investigate the impact of lower and upper clippings on PAPR distributions. Our analytical results, as verified by numerical simulations, provide useful insights and guidelines for VLC OFDM system designs.

  15. Ultraviolet-visible spectroscopy of graphene oxides

    Directory of Open Access Journals (Sweden)

    Qi Lai


    Full Text Available Dispersions of few-layer (1-3 layers, multi-layer (4-10 layers and thick-layer (>10 layers graphene oxide (GO were prepared by a modified Hummers method with different mass ratios of KMnO4 to graphite. Ultraviolet-visible (UV-vis spectroscopic data show that few-layer GO dispersions can be distinguished from multi- and thick-layer dispersions by a more intense peak at 230 nm. Atomic force microscopy (AFM images of few-layer GO contain a single peak, those of multi-layer GO exhibit a shoulder and those of thick-layer GO do not contain a peak or shoulder. These findings allow qualitative analysis of GO dispersions. X-ray photoelectron spectra (XPS show that the change of UV-vis absorption intensity of GO is caused by a conjugative effect related to chromophore aggregation that influences the π-π* plasmon peak.

  16. Coded source imaging simulation with visible light

    Energy Technology Data Exchange (ETDEWEB)

    Wang Sheng [State Key Laboratory of Nuclear Physics and Technology and School of Physics, IHIP, Peking University, Yiheyuan Lu 5, Beijing 100871 (China); Zou Yubin, E-mail: [State Key Laboratory of Nuclear Physics and Technology and School of Physics, IHIP, Peking University, Yiheyuan Lu 5, Beijing 100871 (China); Zhang Xueshuang; Lu Yuanrong; Guo Zhiyu [State Key Laboratory of Nuclear Physics and Technology and School of Physics, IHIP, Peking University, Yiheyuan Lu 5, Beijing 100871 (China)


    A coded source could increase the neutron flux with high L/D ratio. It may benefit a neutron imaging system with low yield neutron source. Visible light CSI experiments were carried out to test the physical design and reconstruction algorithm. We used a non-mosaic Modified Uniformly Redundant Array (MURA) mask to project the shadow of black/white samples on a screen. A cooled-CCD camera was used to record the image on the screen. Different mask sizes and amplification factors were tested. The correlation, Wiener filter deconvolution and Richardson-Lucy maximum likelihood iteration algorithm were employed to reconstruct the object imaging from the original projection. The results show that CSI can benefit the low flux neutron imaging with high background noise.

  17. Electrically Injected UV-Visible Nanowire Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Wang, George T.; Li, Changyi; Li, Qiming; Liu, Sheng; Wright, Jeremy Benjamin; Brener, Igal; Luk, Ting -Shan; Chow, Weng W.; Leung, Benjamin; Figiel, Jeffrey J.; Koleske, Daniel D.; Lu, Tzu-Ming


    There is strong interest in minimizing the volume of lasers to enable ultracompact, low-power, coherent light sources. Nanowires represent an ideal candidate for such nanolasers as stand-alone optical cavities and gain media, and optically pumped nanowire lasing has been demonstrated in several semiconductor systems. Electrically injected nanowire lasers are needed to realize actual working devices but have been elusive due to limitations of current methods to address the requirement for nanowire device heterostructures with high material quality, controlled doping and geometry, low optical loss, and efficient carrier injection. In this project we proposed to demonstrate electrically injected single nanowire lasers emitting in the important UV to visible wavelengths. Our approach to simultaneously address these challenges is based on high quality III-nitride nanowire device heterostructures with precisely controlled geometries and strong gain and mode confinement to minimize lasing thresholds, enabled by a unique top-down nanowire fabrication technique.

  18. Wire grid polarizers for visible wavelengths (United States)

    Johnson, Joshua Hans

    Detailed analysis of wire-grid (WG) polarizers for visible wavelengths is presented. Rigorous coupled-wave analysis (RCWA) is used to model their performance. The optimum choice of metal for the wires is identified, and the effects of different substrate indices of refraction are considered. The polarization properties are considered with changes in the physical parameters, including period, duty cycle, and wire thickness. It is shown that the performance of WG polarizers improves with increasing angle of incidence. The effect of non-square wire profiles is considered, as is the effect of adding additional dielectric layers between the wires and the substrate. The effect of metal oxide layers forming on the wires is also modeled. While most of this work concerns WG polarizers used in transmission, the performance in reflection is also discussed. Several visible-wavelength WG polarizers were fabricated at the Cornell Nanofabrication Facility (CNF) in Ithaca, NY. Electron-beam lithography was used to write the patterns for these devices, and two different methods of pattern transfer were compared. These were the lift-off method and reactive-ion etching (RIE). We found that lift-off could not produce wires thick enough for good polarization properties. RIE could produce much thicker wires with good profiles and was used for all of the experimental work presented here. Two different methods for metal film deposition, evaporation and sputtering were also compared. Films deposited by sputtering were found to have much lower indices of refraction and to not respond to etching as well. Thermally evaporated films performed much better in WG polarizers. Alternative methods for the mass-production of visible-wavelength WG polarizers are also discussed. The performance of the fabricated WG polarizers is compared to theory. When the measured physical parameters are used in RCWA to predict the performance, the measured extinction ratio is found to be much lower than the

  19. Technology Advancement of the Visible Nulling Coronagraph (United States)

    Lyon, Richard G.; Clampin, Mark; Petrone, Peter; Thompson, Patrick; Bolcar, Matt; Madison, Timothy; Woodruff, Robert; Noecker, Charley; Kendrick, Steve


    The critical high contrast imaging technology for the Extrasolar Planetary Imaging Coronagraph (EPIC) mission concept is the visible nulling coronagraph (VNC). EPIC would be capable of imaging jovian planets, dust/debris disks, and potentially super-Earths and contribute to answering how bright the debris disks are for candidate stars. The contrast requirement for EPIC is 10(exp 9) contrast at 125 milli-arseconds inner working angle. To advance the VNC technology NASA/Goddard Space Flight Center, in collaboration with Lockheed-Martin, previously developed a vacuum VNC testbed, and achieved narrowband and broadband suppression of the core of the Airy disk. Recently our group was awarded a NASA Technology Development for Exoplanet Missions to achieve two milestones: (i) 10(exp 8) contrast in narrowband light, and, (ii) 10(ecp 9) contrast in broader band light; one milestone per year, and both at 2 Lambda/D inner working angle. These will be achieved with our 2nd generation testbed known as the visible nulling testbed (VNT). It contains a MEMS based hex-packed segmented deformable mirror known as the multiple mirror array (MMA) and coherent fiber bundle, i.e. a spatial filter array (SFA). The MMA is in one interferometric arm and works to set the wavefront differences between the arms to zero. Each of the MMA segments is optically mapped to a single mode fiber of the SFA, and the SFA passively cleans the sub-aperture wavefront error leaving only piston, tip and tilt error to be controlled. The piston degree of freedom on each segment is used to correct the wavefront errors, while the tip/tilt is used to simultaneously correct the amplitude errors. Thus the VNT controls both amplitude and wavefront errors with a single MMA in closed-loop in a vacuum tank at approx.20 Hz. Herein we will discuss our ongoing progress with the VNT.

  20. Visibility graph analysis on heartbeat dynamics of meditation training (United States)

    Jiang, Sen; Bian, Chunhua; Ning, Xinbao; Ma, Qianli D. Y.


    We apply the visibility graph analysis to human heartbeat dynamics by constructing the complex networks of heartbeat interval time series and investigating the statistical properties of the network before and during chi and yoga meditation. The experiment results show that visibility graph analysis can reveal the dynamical changes caused by meditation training manifested as regular heartbeat, which is closely related to the adjustment of autonomous neural system, and visibility graph analysis is effective to evaluate the effect of meditation.

  1. Lethal effects of short-wavelength visible light on insects


    Hori, Masatoshi; Shibuya, Kazuki; Sato, Mitsunari; Saito, Yoshino


    We investigated the lethal effects of visible light on insects by using light-emitting diodes (LEDs). The toxic effects of ultraviolet (UV) light, particularly shortwave (i.e., UVB and UVC) light, on organisms are well known. However, the effects of irradiation with visible light remain unclear, although shorter wavelengths are known to be more lethal. Irradiation with visible light is not thought to cause mortality in complex animals including insects. Here, however, we found that irradiatio...

  2. Infrared and visible fusion face recognition based on NSCT domain (United States)

    Xie, Zhihua; Zhang, Shuai; Liu, Guodong; Xiong, Jinquan


    Visible face recognition systems, being vulnerable to illumination, expression, and pose, can not achieve robust performance in unconstrained situations. Meanwhile, near infrared face images, being light- independent, can avoid or limit the drawbacks of face recognition in visible light, but its main challenges are low resolution and signal noise ratio (SNR). Therefore, near infrared and visible fusion face recognition has become an important direction in the field of unconstrained face recognition research. In this paper, a novel fusion algorithm in non-subsampled contourlet transform (NSCT) domain is proposed for Infrared and visible face fusion recognition. Firstly, NSCT is used respectively to process the infrared and visible face images, which exploits the image information at multiple scales, orientations, and frequency bands. Then, to exploit the effective discriminant feature and balance the power of high-low frequency band of NSCT coefficients, the local Gabor binary pattern (LGBP) and Local Binary Pattern (LBP) are applied respectively in different frequency parts to obtain the robust representation of infrared and visible face images. Finally, the score-level fusion is used to fuse the all the features for final classification. The visible and near infrared face recognition is tested on HITSZ Lab2 visible and near infrared face database. Experiments results show that the proposed method extracts the complementary features of near-infrared and visible-light images and improves the robustness of unconstrained face recognition.

  3. Invisible Hyperbolic Metamaterial Nanotube at Visible Frequency (United States)

    Kim, Kyoung-Ho; No, You-Shin; Chang, Sehwan; Choi, Jae-Hyuck; Park, Hong-Gyu


    Subwavelength-scale metal and dielectric nanostructures have served as important building blocks for electromagnetic metamaterials, providing unprecedented opportunities for manipulating the optical response of the matter. Recently, hyperbolic metamaterials have been drawing particular interest because of their unusual optical properties and functionalities, such as negative refraction and hyperlensing of light. Here, as a promising application of a hyperbolic metamaterial at visible frequency, we propose an invisible nanotube that consists of metal and dielectric alternating thin layers. The theoretical study of the light scattering of the layered nanotube reveals that almost-zero scattering can be achieved at a specific wavelength when the transverse-electric- or transverse-magnetic-polarized light is incident to the nanotube. In addition, the layered nanotube can be described as a radial-anisotropic hyperbolic metamaterial nanotube. The low scattering occurs when the effective permittivity of the hyperbolic nanotube in the angular direction is near zero, and thus the invisibility of the layered nanotube can be efficiently obtained by analyzing the equivalent hyperbolic nanotube. Our new method to design and tune an invisible nanostructure represents a significant step toward the practical implementation of unique nanophotonic devices such as invisible photodetectors and low-scattering near-field optical microscopes. PMID:26522815

  4. Catadioptric lenses in Visible Light Communications (United States)

    Garcia-Marquez, J.; Valencia, J. C.; Perez, H.; Topsu, S.


    Since few years ago, visible light communications (VLC) have experience an accelerated interest from a research point of view. The beginning of this decade has seen many improvements in VLC at an electronic level. High rates of transmission at low bit error ratios (BER) have been reported. A few numbers of start-ups have initiated activities to offer a variety of applications ranging from indoor geo-localization to internet, but in spite of these advancements, some other problems arise. Long-range transmissions mean a high BER which reduce the number of applications. In this sense, new redesigned optical collectors or in some cases, optical reflectors must be considered to ensure a low BER at higher distance transmissions. Here we also expose a preliminary design of a catadioptric and monolithical lens for a LI-FI receiver with two rotationally symmetrical main piecewise surfaces za and zb. These surfaces are represented in a system of cylindrical coordinates with an anterior surface za with a central and refractive sector surrounded by a peripheral reflective sector and a back piecewise surface zb with a central refractive sector and a reflective sector, both characterized as ideal for capturing light within large acceptance angles.

  5. [Anatomical visibility of the meridian information channels]. (United States)

    Chang, Xi-lang


    The "structure imperfectness of signal channel rule" put forward by the author of the present paper may provide a theoretical evidence for the systematicness of meridian information channel. The conclusion that no special structure of the meridian-collateral system has been found is likely to serve as a piece of counterevidence. According to the latest structural view, the development of capillaries, lymphatic vessels and nerves needs target cells-released inducible factors. In the initial phase of the development of the organism, the asymmetry of the interspaces among cells results in the production and arrangement imbalance of the sequential factors which make the capillaries, lymphatic vessels and nerves distribute sequentially in time and space. Meridian-collateral, following the "systemic statistic distribution rule", is a general expression of this distribution pattern. As a systematic structure, the meridian-collateral system distributes in an optimized way in the human body and has both orderly and compatible characteristics. The author thinks that the meridian-collateral information channel is anatomically visible in the time and spatial structure, and in its logical structure and compatibility during the process of growth. Hence, many techniques of delicate anatomy, quantitative anatomy, growth anatomy, comparative anatomy, tridimensional remodeling of living creature and dynamical remodeling of growth all should be used as the important tools for studying the meridian information channel. The theory and the anatomical techniques determine what you would finally find.

  6. A proposed visible FEL Facility at Boeing

    Energy Technology Data Exchange (ETDEWEB)

    Dowell, D.H.; Adamski, J.L.; Hayward, T.D. [Boeing Defense & Space Group, Seattle, WA (United States)] [and others


    A 1-kW average power, visible wavelength FEL is described, based on a 120-MeV, 0.1. A macropulse average current linac operating at a duty factor of 0. 6% and having average beam power of 70 kW. The accelerator will employ a demonstrated photoinjector, 18-MeV, 433-MHz linac as an injector, followed by a 1300-MHz longitudinal phase space {open_quotes} linearizer,{close_quotes} a magnetic buncher chicane, and seven 1300-MHz, pulsed traveling wave linac sections. The magnets used to transport the beam from the linac to the FEL centerline, the 5-m THUNDER wiggler, and the optical resonator will be reclaimed from previous FEL demonstration experiments. We expect to attain pulse lengths of 7 ps for 3.5 nC, with minimal distortion of the pulse profile and normalized rms emittance of 7.5 {+-} 2.5 {pi} mm-mr. FELEX projects a laser conversion efficiency of 4.3 %, yielding average output of 3 kW.

  7. High power diode lasers converted to the visible

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin; Hansen, Anders Kragh; Andersen, Peter E.


    High power diode lasers have in recent years become available in many wavelength regions. However, some spectral regions are not well covered. In particular, the visible spectral range is lacking high power diode lasers with good spatial quality. In this paper, we highlight some of our recent...... results in nonlinear frequency conversion of high power near infrared diode lasers to the visible spectral region....

  8. Creating Collection Visibility for School Library Media Centres in ...

    African Journals Online (AJOL)

    This paper focuses on the importance of creating collection visibility through the use of freely available softwares such as the CDS/ISIS for windows and The Library'Ihing as a strategy for the development of school library media centres in Nigeria. It discusses the benefits of having a visible collection among which is easy ...

  9. Prediction of Fog/Visibility over India using NWP Model

    Indian Academy of Sciences (India)


    visibility range 200-500 m) at Amritsar (Fig. 1b). The criteria for classification of fog in different categories based on observed visibility is given in Table 1. The categories are based on International Civil Aviation Organization (ICAO) definition. Day-1.

  10. Combinatorial Properties and Recognition of Unit Square Visibility Graphs

    NARCIS (Netherlands)

    Casel, Katrin; Fernau, Henning; Grigoriev, Alexander; Schmid, Markus L.; Whitesides, Sue; Larsen, Kim G.; Bodlaender, Hans L.; Raskin, Jean-Francois


    Unit square (grid) visibility graphs (USV and USGV, resp.) are described by axis-parallel visibility between unit squares placed (on integer grid coordinates) in the plane. We investigate combinatorial properties of these graph classes and the hardness of variants of the recognition problem, i. e.,

  11. Needle Tip Visibility in 3D Ultrasound Images

    NARCIS (Netherlands)

    M. Arif (Muhammad); A. Moelker (Adriaan); T.W. van Walsum (Theo)


    textabstractAim: Needle visibility is crucial for effective and safe ultrasound-guided interventional procedures. Several studies have investigated needle visibility in 2D ultrasound imaging, but less information is available for 3D ultrasound imaging, a modality that has great potential for image

  12. Visibility of University of Zululand and Moi University Researchers in ...

    African Journals Online (AJOL)

    This paper reflects on the representation of the University of Zululand (UNIZULU) and Moi University (MU)'s research publications in WoS (Web of Science) and Scopus between 2003 and 2013 as an indicator of active research engagement, quality, and international visibility. Research quality, visibility and collaboration ...

  13. Enhancing research visibility of academics: the role of academic ...

    African Journals Online (AJOL)

    Despite so many researches stemming from most African academic institutions, not many are visible. This may be attributed to low quality of research works and lack of subscription fees. This article offers suggestions on libraries' role in promoting the quality of research in order to increase its visibility. It also offers a brief on ...

  14. Visible Light Communication Physical Layer Design for Jist Simulation

    Directory of Open Access Journals (Sweden)

    Tomaš Boris


    Full Text Available Current advances in computer networking consider using visible light spectrum to encode and decode digital data. This approach is relatively non expensive. However, designing appropriate MAC or any other upper layer protocol for Visible Light Communication (VLC requires appropriate hardware. This paper proposes and implements such hardware simulation (physical layer that is compatible with existing network stack.

  15. Temperature variability, intensity of wind speed and visibility during ...

    African Journals Online (AJOL)

    The study assessed the connections between temperature variability, intensity of wind speed and their effect on visibility of Makurdi town during the harmattan season. Data on mean monthly temperature of harmattan months of November, December, January and February (2001 to 2011), Wind speed and visibility records ...

  16. Utilization of Large Scale Surface Models for Detailed Visibility Analyses (United States)

    Caha, J.; Kačmařík, M.


    This article demonstrates utilization of large scale surface models with small spatial resolution and high accuracy, acquired from Unmanned Aerial Vehicle scanning, for visibility analyses. The importance of large scale data for visibility analyses on the local scale, where the detail of the surface model is the most defining factor, is described. The focus is not only the classic Boolean visibility, that is usually determined within GIS, but also on so called extended viewsheds that aims to provide more information about visibility. The case study with examples of visibility analyses was performed on river Opava, near the Ostrava city (Czech Republic). The multiple Boolean viewshed analysis and global horizon viewshed were calculated to determine most prominent features and visibility barriers of the surface. Besides that, the extended viewshed showing angle difference above the local horizon, which describes angular height of the target area above the barrier, is shown. The case study proved that large scale models are appropriate data source for visibility analyses on local level. The discussion summarizes possible future applications and further development directions of visibility analyses.

  17. Establishment of an Eastern Visibility Fine-Particle Network

    Energy Technology Data Exchange (ETDEWEB)

    Evans, E.G.; Fitz-Simons, T.; Lumpkin, T.A.; Barnard, W.F.


    A comprehensive assessment of eastern regional haze is being undertaken by EPA's Environmental Monitoring Systems Laboratory. An Eastern Visibility Fine-Particle Network (EVFPN) is being set up to study the relationships between fine particles and visibility. A long-term data base will be established to aid in determining spatial and temporal variations in indicators of visibility degradation in the Eastern United States. A further refinement of the visibility/particulate components relationships, with emphasis given to the nonsulfate components such as carbon and nitrate, will be developed. The monitoring strategy used to obtain optical properties, aerosol characteristics, and the characteristics of a scene are discussed along with the general overview of the Eastern Visibility Fine-Particle Network.

  18. Lethal effects of short-wavelength visible light on insects (United States)

    Hori, Masatoshi; Shibuya, Kazuki; Sato, Mitsunari; Saito, Yoshino


    We investigated the lethal effects of visible light on insects by using light-emitting diodes (LEDs). The toxic effects of ultraviolet (UV) light, particularly shortwave (i.e., UVB and UVC) light, on organisms are well known. However, the effects of irradiation with visible light remain unclear, although shorter wavelengths are known to be more lethal. Irradiation with visible light is not thought to cause mortality in complex animals including insects. Here, however, we found that irradiation with short-wavelength visible (blue) light killed eggs, larvae, pupae, and adults of Drosophila melanogaster. Blue light was also lethal to mosquitoes and flour beetles, but the effective wavelength at which mortality occurred differed among the insect species. Our findings suggest that highly toxic wavelengths of visible light are species-specific in insects, and that shorter wavelengths are not always more toxic. For some animals, such as insects, blue light is more harmful than UV light.

  19. The Development of Visible-Light Photoredox Catalysis in Flow. (United States)

    Garlets, Zachary J; Nguyen, John D; Stephenson, Corey R J


    Visible-light photoredox catalysis has recently emerged as a viable alternative for radical reactions otherwise carried out with tin and boron reagents. It has been recognized that by merging photoredox catalysis with flow chemistry, slow reaction times, lower yields, and safety concerns may be obviated. While flow reactors have been successfully applied to reactions carried out with UV light, only recent developments have demonstrated the same potential of flow reactors for the improvement of visible-light-mediated reactions. This review examines the initial and continuing development of visible-light-mediated photoredox flow chemistry by exemplifying the benefits of flow chemistry compared with conventional batch techniques.

  20. Prague-Ruzyne airport visibility data processing results (United States)

    Kvicera, Vaclav; Grabner, Martin; Vasicek, Jiri


    Experimental research in the Department of Frequency Engineering in the Czech Metrology Institute (CMI) in Prague, the Czech Republic, is focused on stability of received signal on terrestrial radio and optical communication links. A free space optical (FSO) communication system can provide a high bandwidth solution to last mile broadband access. Dense fog events can cause serious attenuation of optical waves. The availability performances of FSO links are seriously affected by lower atmospheric visibility. Fog seems to be the most important impairment factor for FSO communication links. Therefore, our experimental research is also focused on processing meteorological data to obtain basic information for the assessment of availability performances of FSO links. The visibility measured at airports provides a good estimate for the assessment of fog impairment. The visibility data that is measured and stored in meteorological stations or airports is usually used for the calculation of specific attenuation due to fog in accordance with either the relevant ITU-R Recommendation or other common methods. Fog visibility data obtained by the Vaisala transmissometer at the Prague-Ruzyne airport from January 1996 to December 2008 (13 years of observation) was statistically processed over the individual years, the individual months and the individual hours and the following cumulative distributions (CDs) of visibility were obtained: 1) CDs of visibility for individual years, 2) CDs of visibility for individual months over the whole period of processing, 3) CDs of visibility for the worst hour over the whole period of processing, and 4) CDs of visibility for the average year and the average worst month over the entire 13 year period of processing. It can be concluded that the frequency of fog events shows a great year-to-year variability in accordance with the frequency of individual synoptic situations occurring during the year. Fog occurred most frequently in November and

  1. Website visibility the theory and practice of improving rankings

    CERN Document Server

    Weideman, Melius


    The quest to achieve high website rankings in search engine results is a prominent subject for both academics and website owners/coders. Website Visibility marries academic research results to the world of the information practitioner and contains a focused look at the elements which contribute to website visibility, providing support for the application of each element with relevant research. A series of real-world case studies with tested examples of research on website visibility elements and their effect on rankings are reviewed.Written by a well-respected academic and practitioner in the

  2. Mechanochemical Synthesis of Visible Light Sensitive Titanium Dioxide Photocatalyst

    Directory of Open Access Journals (Sweden)

    Jan Šubrt


    Full Text Available Phase transition of anatase nanoparticles into the phases TiO2-II and rutile under grinding was studied. The addition of ammonium carbamate to the reaction mixture inhibits the phase conversion and the cold welding of particles. The UV-visible absorption spectrum showed narrowing the band gap width after grinding with an ammonium carbamate additive resulting in shift of the light absorption of the ground sample towards the visible region. By EPR, intensive formation of OH• radical at irradiation of the sample with both UV (λ > 300 nm and visible (λ > 435 nm light was observed. High photocatalytic activity of the ground sample in visible light region was demonstrated also by measurement of kinetics of the photocatalytic decomposition of 4-chlorophenol.

  3. Visible semantics: an algebraic semantics for automatic verification of algorithms


    Palasí Lallana, Vicent Ramon


    A new semantics for algebraic specifications, called visible semantics, is defined. Its most notable property is that it is specially suitable for dealing with the problem of program correctness. Some properties of this semantics are proved and some conclusions described.

  4. Stakeholders' perceptions about visibility and accountability of the ...

    African Journals Online (AJOL)

    n=34) and community care givers (n=23). A self-administered questionnaire was used to collect data. Forty- one questions grouped into three themes (visibility of extension services, accountability of extension and knowing of state agricultural ...

  5. CLPX Airborne: Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) Data (United States)

    National Aeronautics and Space Administration — This data set consists of apparent surface reflectance, subpixel snow-covered area and grain size inferred from data acquired by the Airborne Visible/Infrared...

  6. Development of a lesbian, gay, bisexual visibility management scale. (United States)

    Lasser, Jon; Ryser, Gail R; Price, Larry R


    Many lesbian, gay, and bisexual (LGB) individuals manage the degree to which their sexual orientation is known to others. Visibility management, the process of regulating the exposure of one's orientation, is an important part of the lesbian/gay/bisexual experience in community, family, and virtually all other social settings. The degree to which one allows his or her sexual orientation to be visible can have a profound impact on stress, health, self-esteem, interpersonal relationships, and quality of life. The purpose of the present study was to develop a valid and reliable measure of visibility management. The Lesbian, Gay, Bisexual-Visibility Management Scale was constructed and piloted with a small sample of LGB adults. Results support the potential utility of the LGB scale based on satisfactory evidence of construct validity, item-level discrimination, and subscale reliability.

  7. NOS CO-OPS Meteorological Data, Visibility, 6-Minute (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has Visibility data from NOAA NOS Center for Operational Oceanographic Products and Services (CO-OPS). WARNING: These preliminary data have not been...

  8. Assessing Visibility of Individual Transmission Errors in Networked Video

    DEFF Research Database (Denmark)

    Korhonen, Jari; Mantel, Claire


    Traditionally, subjective video quality is assessed by user experiments involving quality ratings, pairwise comparisons, or rank ordering, based on the overall impression of quality. Less attention has been paid on assessing the visibility of individual defects. However, many practical applications...

  9. Global trends in visibility: implications for dust sources

    Directory of Open Access Journals (Sweden)

    N. M. Mahowald


    Full Text Available There is a large uncertainty in the relative roles of human land use, climate change and carbon dioxide fertilization in changing desert dust source strength over the past 100 years, and the overall sign of human impacts on dust is not known. We used visibility data from meteorological stations in dusty regions to assess the anthropogenic impact on long term trends in desert dust emissions. We did this by looking at time series of visibility derived variables and their correlations with precipitation, drought, winds, land use and grazing. Visibility data are available at thousands of stations globally from 1900 to the present, but we focused on 357 stations with more than 30 years of data in regions where mineral aerosols play a dominant role in visibility observations. We evaluated the 1974 to 2003 time period because most of these stations have reliable records only during this time. We first evaluated the visibility data against AERONET aerosol optical depth data, and found that only in dusty regions are the two moderately correlated. Correlation coefficients between visibility-derived variables and AERONET optical depths indicate a moderate correlation (0.47, consistent with capturing about 20% of the variability in optical depths. Two visibility-derived variables appear to compare the best with AERONET observations: the fraction of observations with visibility less than 5 km (VIS5 and the surface extinction (EXT. Regional trends show that in many dusty places, VIS5 and EXT are statistically significantly correlated with the Palmer drought severity index (based on precipitation and temperature or surface wind speeds, consistent with dust temporal variability being largely driven by meteorology. This is especially true for North African and Chinese dust sources, but less true in the Middle East, Australia or South America, where there are not consistent patterns in the correlations. Climate indices such as El Nino or the North Atlantic

  10. Pavement Marking Visibility Requirements During Wet Night Conditions


    Gibbons, Ronald B. (Ronald Bruce)


    This study investigated the performance of pavement markings in wet night conditions. Typically, performance will decrease in wet conditions. The degradation is a result of flooding of the marking optics and a change in the optical media, thereby reducing retroreflectivity and the visibility distance. Several technologies are available to improve the visibility of markings under wet conditions. This study used four technologies and evaluated them in a dynamic situation. In the experiment, veh...

  11. Coaxial visible and FIR camera system with accurate geometric calibration (United States)

    Ogino, Yuka; Shibata, Takashi; Tanaka, Masayuki; Okutomi, Masatoshi


    A far-infrared (FIR) image contains important invisible information for various applications such as night vision and fire detection, while a visible image includes colors and textures in a scene. We present a coaxial visible and FIR camera system accompanied to obtain the complementary information of both images simultaneously. The proposed camera system is composed of three parts: a visible camera, a FIR camera, and a beam-splitter made from silicon. The FIR radiation from the scene is reflected at the beam-splitter, while the visible radiation is transmitted through this beam-splitter. Even if we use this coaxial visible and FIR camera system, the alignment between the visible and FIR images are not perfect. Therefore, we also present the joint calibration method which can simultaneously estimate accurate geometric parameters of both cameras, i.e. the intrinsic parameters of both cameras and the extrinsic parameters between both cameras. In the proposed calibration method, we use a novel calibration target which has a two-layer structure where thermal emission property of each layer is different. By using the proposed calibration target, we can stably and precisely obtain the corresponding points of the checker pattern in the calibration target from both the visible and the FIR images. Widely used calibration tools can accurately estimate both camera parameters. We can obtain aligned visible and FIR images by the coaxial camera system with precise calibration using two-layer calibration target. Experimental results demonstrate that the proposed camera system is useful for various applications such as image fusion, image denoising, and image up-sampling.

  12. Gouy phase and visibility in the double-slit experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, C.J.S.; Marinho, L.S. [Departamento de Física, Universidade Federal do Piauí, Campus Ministro Petrônio Portela, CEP 64049-550, Teresina, PI (Brazil); Brazil, T.B. [Instituto de Física, Universidade de São Paulo, Caixa Postal 66318, 05315-970 São Paulo, SP (Brazil); Cabral, L.A. [Curso de Física, Universidade Federal do Tocantins, Caixa Postal 132, CEP 77804-970, Araguaína, TO (Brazil); Oliveira Jr, J.G.G. de [Departamento de Ciências Exatas e Tecnológicas, Universidade Estadual de Santa Cruz, Caixa Postal 45662-900, Ilhéus, BA (Brazil); Sampaio, M.D.R. [Departamento de Física, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Caixa Postal 702, CEP 30161-970, Belo Horizonte, Minas Gerais (Brazil); Centre for Particle Theory CM310 Durham University - St. John’s College B6 (United States); Paz, I.G. da, E-mail: [Departamento de Física, Universidade Federal do Piauí, Campus Ministro Petrônio Portela, CEP 64049-550, Teresina, PI (Brazil)


    We study a matter wave double-slit experiment with unequal aperture widths in order to evaluate the effect of the Gouy phase on the visibility/predictability. While the predictability changes as one increases the width of one of the slits, the visibility receives a contribution from the Gouy phase at a specific point in the detection screen. Consequently such apparatus constitutes a simple device for measuring the Gouy phase of matter waves. We illustrate it numerically for neutrons.

  13. Source-oriented model for air pollutant effects on visibility


    Eldering, A; Cass, G R


    A source-oriented model for air pollutant effects on visibility has been developed that can compute light scattering, light extinction, and estimated visual range directly from data on gas phase and primary particle phase air pollutant emissions from sources. The importance of such a model is that it can be used to compute the effect of emission control proposals on visibility-related parameters in advance of the adoption of such control programs. The model has been assembled by embedding sev...

  14. Effects of forest fires on visibility and air quality (United States)

    Douglas G. Fox; Allen R. Riebau


    The U.S. Clean Air Act establishes the goal of preventing future and remedying existing visibility impairment in 156 Class I areas (national parks, wilderness areas, and wildlife refuges). A key element in implementing this goal is the Regional Haze Regulation (RHR). RHR is based on relating impaired visibility, using metrics of extinction (inverse megameters and/or ‘‘...

  15. Visibility estimation of advertising panels in football sequences


    Varas González, David


    In this work, we propose a robust classification system that estimates the advertising panels visibility in real time. For each frame of the sequence, a set of descriptors is extracted to characterize a specific part of the scene: the grass field. Gathering all these descriptors, a decision tree determines whether the LED panels are visible in that frame. In order to improve the robustness of the algorithm, the redundancy of the temporal domain is exploited. The validity of ...

  16. Disease, communication, and the ethics of (in) visibility. (United States)

    Pietrzak-Franger, Monika Monika; Holmes, Martha Stoddard


    As the recent Ebola outbreak demonstrates, visibility is central to the shaping of political, medical, and socioeconomic decisions. The symposium in this issue of the Journal of Bioethical Inquiry explores the uneasy relationship between the necessity of making diseases visible, the mechanisms of legal and visual censorship, and the overall ethics of viewing and spectatorship, including the effects of media visibility on the perception of particular "marked" bodies. Scholarship across the disciplines of communication, anthropology, gender studies, and visual studies, as well as a photographer's visual essay and memorial reflection, throw light on various strategies of visualization and (de)legitimation and link these to broader socioeconomic concerns. Questions of the ethics of spectatorship, such as how to evoke empathy in the representation of individuals' suffering without perpetuating social and economic inequalities, are explored in individual, (trans-)national, and global contexts, demonstrating how disease (in)visibility intersects with a complex nexus of health, sexuality, and global/national politics. A sensible management of visibility--an "ecology of the visible"--can be productive of more viable ways of individual and collective engagement with those who suffer.

  17. Visibility of medical informatics regarding bibliometric indices and databases. (United States)

    Spreckelsen, Cord; Deserno, Thomas M; Spitzer, Klaus


    The quantitative study of the publication output (bibliometrics) deeply influences how scientific work is perceived (bibliometric visibility). Recently, new bibliometric indices and databases have been established, which may change the visibility of disciplines, institutions and individuals. This study examines the effects of the new indices on the visibility of Medical Informatics. By objective criteria, three sets of journals are chosen, two representing Medical Informatics and a third addressing Internal Medicine as a benchmark. The availability of index data (index coverage) and the aggregate scores of these corpora are compared for journal-related (Journal impact factor, Eigenfactor metrics, SCImago journal rank) and author-related indices (Hirsch-index, Egghes G-index). Correlation analysis compares the dependence of author-related indices. The bibliometric visibility depended on the research focus and the citation database: Scopus covers more journals relevant for Medical Informatics than ISI/Thomson Reuters. Journals focused on Medical Informatics' methodology were negatively affected by the Eigenfactor metrics, while the visibility profited from an interdisciplinary research focus. The correlation between Hirsch-indices computed on citation databases and the Internet was strong. The visibility of smaller technology-oriented disciplines like Medical Informatics is changed by the new bibliometric indices and databases possibly leading to suitably changed publication strategies. Freely accessible author-related indices enable an easy and adequate individual assessment.

  18. Quantitative Model for Supply Chain Visibility: Process Capability Perspective

    Directory of Open Access Journals (Sweden)

    Youngsu Lee


    Full Text Available Currently, the intensity of enterprise competition has increased as a result of a greater diversity of customer needs as well as the persistence of a long-term recession. The results of competition are becoming severe enough to determine the survival of company. To survive global competition, each firm must focus on achieving innovation excellence and operational excellence as core competency for sustainable competitive advantage. Supply chain management is now regarded as one of the most effective innovation initiatives to achieve operational excellence, and its importance has become ever more apparent. However, few companies effectively manage their supply chains, and the greatest difficulty is in achieving supply chain visibility. Many companies still suffer from a lack of visibility, and in spite of extensive research and the availability of modern technologies, the concepts and quantification methods to increase supply chain visibility are still ambiguous. Based on the extant researches in supply chain visibility, this study proposes an extended visibility concept focusing on a process capability perspective and suggests a more quantitative model using Z score in Six Sigma methodology to evaluate and improve the level of supply chain visibility.

  19. Efficient visibility encoding for dynamic illumination in direct volume rendering. (United States)

    Kronander, Joel; Jönsson, Daniel; Löw, Joakim; Ljung, Patric; Ynnerman, Anders; Unger, Jonas


    We present an algorithm that enables real-time dynamic shading in direct volume rendering using general lighting, including directional lights, point lights, and environment maps. Real-time performance is achieved by encoding local and global volumetric visibility using spherical harmonic (SH) basis functions stored in an efficient multiresolution grid over the extent of the volume. Our method enables high-frequency shadows in the spatial domain, but is limited to a low-frequency approximation of visibility and illumination in the angular domain. In a first pass, level of detail (LOD) selection in the grid is based on the current transfer function setting. This enables rapid online computation and SH projection of the local spherical distribution of visibility information. Using a piecewise integration of the SH coefficients over the local regions, the global visibility within the volume is then computed. By representing the light sources using their SH projections, the integral over lighting, visibility, and isotropic phase functions can be efficiently computed during rendering. The utility of our method is demonstrated in several examples showing the generality and interactive performance of the approach.

  20. Visibility graph analysis of wall turbulence time-series (United States)

    Iacobello, Giovanni; Scarsoglio, Stefania; Ridolfi, Luca


    The spatio-temporal features of the velocity field of a fully-developed turbulent channel flow are investigated through the natural visibility graph (NVG) method, which is able to fully map the intrinsic structure of the time-series into complex networks. Time-series of the three velocity components, (u , v , w), are analyzed at fixed grid-points of the whole three-dimensional domain. Each time-series was mapped into a network by means of the NVG algorithm, so that each network corresponds to a grid-point of the simulation. The degree centrality, the transitivity and the here proposed mean link-length were evaluated as indicators of the global visibility, inter-visibility, and mean temporal distance among nodes, respectively. The metrics were averaged along the directions of homogeneity (x , z) of the flow, so they only depend on the wall-normal coordinate, y+. The visibility-based networks, inheriting the flow field features, unveil key temporal properties of the turbulent time-series and their changes moving along y+. Although intrinsically simple to be implemented, the visibility graph-based approach offers a promising and effective support to the classical methods for accurate time-series analyses of inhomogeneous turbulent flows.

  1. Motivation Moderates the Effects of Social Support Visibility. (United States)

    Zee, Katherine S; Cavallo, Justin V; Flores, Abdiel J; Bolger, Niall; Higgins, E Tory


    Social support can sometimes have negative consequences for recipients. One way of circumventing these negative effects is to provide support in an 'invisible' or indirect manner, such that recipients do not construe the behavior as a supportive act. However, little is known about how recipients' motivational states influence when visible (direct) support or invisible support is more beneficial. Using the framework of Regulatory Mode Theory, we predicted that recipients motivated to engage in critical evaluation (i.e., those with a predominant assessment motivation) would find invisible support more beneficial than visible support, whereas recipients motivated to initiate action (i.e., those with a predominant locomotion motivation) would find visible support more beneficial than invisible support. Findings from one 2 × 2 experiment (Study 1), two laboratory experiments (Studies 2-3), one dyadic study involving support conversations between friends (Study 4), and a meta-analysis aggregating data from all four studies supported these hypotheses. As predicted, support outcomes were better for assessment predominant recipients following invisible support, but were better for locomotion predominant recipients following visible support. Results indicate that support attempts could be made more effective by considering both support visibility and recipient motivation. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  2. Inequality and visibility of wealth in experimental social networks. (United States)

    Nishi, Akihiro; Shirado, Hirokazu; Rand, David G; Christakis, Nicholas A


    Humans prefer relatively equal distributions of resources, yet societies have varying degrees of economic inequality. To investigate some of the possible determinants and consequences of inequality, here we perform experiments involving a networked public goods game in which subjects interact and gain or lose wealth. Subjects (n = 1,462) were randomly assigned to have higher or lower initial endowments, and were embedded within social networks with three levels of economic inequality (Gini coefficient = 0.0, 0.2, and 0.4). In addition, we manipulated the visibility of the wealth of network neighbours. We show that wealth visibility facilitates the downstream consequences of initial inequality-in initially more unequal situations, wealth visibility leads to greater inequality than when wealth is invisible. This result reflects a heterogeneous response to visibility in richer versus poorer subjects. We also find that making wealth visible has adverse welfare consequences, yielding lower levels of overall cooperation, inter-connectedness, and wealth. High initial levels of economic inequality alone, however, have relatively few deleterious welfare effects.

  3. Visible light driven plasmonic photochemistry on nano-textured silver. (United States)

    Walia, Jaspreet; Guay, Jean-Michel; Krupin, Oleksiy; Variola, Fabio; Berini, Pierre; Weck, Arnaud


    Plasmon assisted generation of silver sulfate from dodecanethiol is demonstrated on a nano-textured silver substrate with a strong surface plasmon resonance in the visible range. The observed photo-physical processes are attributed to hot charge carriers that are generated from the excitation of surface plasmon resonances using 532 nm laser light. Excited charge carriers are responsible for cleaving the alkane chain, and for generating reactive oxygen species which rapidly photooxidize the exposed sulfur atoms. The ability to drive photochemical reactions with photon energies in the visible range rather than in the UV, on nano-textured silver surfaces, will enable researchers to study photochemical transformations for a wide variety of applications. The strong optical absorbance across the visible range, combined with the fact that the substrates can be fabricated over large areas, naturally makes them candidates for solar driven photochemical applications, and for large scale plasmonic reactors.

  4. Young children's tool innovation across culture: Affordance visibility matters. (United States)

    Neldner, Karri; Mushin, Ilana; Nielsen, Mark


    Young children typically demonstrate low rates of tool innovation. However, previous studies have limited children's performance by presenting tools with opaque affordances. In an attempt to scaffold children's understanding of what constitutes an appropriate tool within an innovation task we compared tools in which the focal affordance was visible to those in which it was opaque. To evaluate possible cultural specificity, data collection was undertaken in a Western urban population and a remote Indigenous community. As expected affordance visibility altered innovation rates: young children were more likely to innovate on a tool that had visible affordances than one with concealed affordances. Furthermore, innovation rates were higher than those reported in previous innovation studies. Cultural background did not affect children's rates of tool innovation. It is suggested that new methods for testing tool innovation in children must be developed in order to broaden our knowledge of young children's tool innovation capabilities. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Visible aging signs as risk markers for ischemic heart disease

    DEFF Research Database (Denmark)

    Christoffersen, Mette; Tybjærg-Hansen, Anne


    , and are mostly speculative. As a consequence of inconsistent findings and lack of mechanistic explanations for the observed associations with ischemic heart disease, consensus on the clinical importance of these visible aging signs has been lacking. The aim of this review is for each of the visible aging signs......Association of common aging signs (i.e., male pattern baldness, hair graying, and facial wrinkles) as well as other age-related appearance factors (i.e., arcus corneae, xanthelasmata, and earlobe crease) with increased risk of ischemic heart disease was initially described in anecdotal reports from...... clinicians observing trends in the physical appearance of patients with ischemic heart disease. Following these early observations numerous epidemiological studies have reported these associations. Since the prevalences of both visible aging signs and ischemic heart disease have a strong correlation...

  6. Development of Visible Light-Responsive Sensitized Photocatalysts

    Directory of Open Access Journals (Sweden)

    Donghua Pei


    Full Text Available The paper presents a review of studies about the visible-light-promoted photodegradation of the contaminants and energy conversion with sensitized photocatalysts. Herein we studied mechanism, physical properties, and synergism effect of the sensitized photocatalysts as well as the method for enhancing the photosensitized effect. According to the reported studies in the literature, inorganic sensitizers, organic dyes, and coordination metal complexes were very effective sensitizers that were studied mostly, of which organic dyes photosensitization is the most widely studied modified method. Photosensitization is an important way to extend the excitation wavelength to the visible range, and therefore sensitized photocatalysts play an important role in the development of visible light-responsive photocatalysts for future industrialized applications. This paper mainly describes the types, modification, photocatalytic performance, application, and the developments of photosensitization for environmental application.

  7. Microtruss structures with enhanced elasticity fabricated through visible light photocuring

    Directory of Open Access Journals (Sweden)

    Hari Nanthakumar

    Full Text Available We report on the fabrication of an open cellular solid structure using visible light photocuring in combination with light-induced self-writing. A visible light sensitive photopolymer is irradiated with multiple arrays of microscale optical beams, which are generated from LEDs. These beams undergo self-trapping and elicit the inscription of microscale, solid struts into the medium. This process creates a structure consisting of multiple, intersecting struts that form a microtruss structure. Such structures retain their elasticity at higher temperatures as compared to a bulk film of the same thickness. This is the first demonstration of visible light photocuring of photopolymers into a microtruss structure, as well as investigation into their elastic properties under tension. Keywords: Polymers, Self-trapping, Microstructures, Cellular solids

  8. Dark/visible parallel universes and Big Bang nucleosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Bertulani, C. A.; Frederico, T.; Fuqua, J.; Hussein, M. S.; Oliveira, O.; Paula, W. de [Department of Physics and Astronomy, Texas A and M University-Commerce, Commerce TX 75429 (United States); Departamento de Fisica, Instituto Tecnologico de Aeronautica, DCTA 12.228-900, Sao Jose dos Campos, SP (Brazil); Department of Physics and Astronomy, Texas A and M University-Commerce, Commerce TX 75429 (United States); Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, 05314-970 Sao Paulo, SP (Brazil); Departamento de Fisica, Instituto Tecnologico de Aeronautica, DCTA 12.228-900, Sao Jose dos Campos, SP, Brazil and Departamento de Fisica, Universidade de Coimbra, 3004-516 Coimbra (Portugal); Departamento de Fisica, Instituto Tecnologico de Aeronautica, DCTA 12.228-900, Sao Jose dos Campos, SP (Brazil)


    We develop a model for visible matter-dark matter interaction based on the exchange of a massive gray boson called herein the Mulato. Our model hinges on the assumption that all known particles in the visible matter have their counterparts in the dark matter. We postulate six families of particles five of which are dark. This leads to the unavoidable postulation of six parallel worlds, the visible one and five invisible worlds. A close study of big bang nucleosynthesis (BBN), baryon asymmetries, cosmic microwave background (CMB) bounds, galaxy dynamics, together with the Standard Model assumptions, help us to set a limit on the mass and width of the new gauge boson. Modification of the statistics underlying the kinetic energy distribution of particles during the BBN is also discussed. The changes in reaction rates during the BBN due to a departure from the Debye-Hueckel electron screening model is also investigated.


    Directory of Open Access Journals (Sweden)

    Nicolas Hautière


    Full Text Available The contrast of outdoor images acquired under adverse weather conditions, especially foggy weather, is altered by the scattering of daylight by atmospheric particles. As a consequence, differentmethods have been designed to restore the contrast of these images. However, there is a lack of methodology to assess the performances of the methods or to rate them. Unlike image quality assessment or image restoration areas, there is no easy way to have a reference image, which makes the problem not straightforward to solve. In this paper, an approach is proposed which consists in computing the ratio between the gradient of the visible edges between the image before and after contrast restoration. In this way, an indicator of visibility enhancement is provided based on the concept of visibility level, commonly used in lighting engineering. Finally, the methodology is applied to contrast enhancement assessment and to the comparison of tone-mapping operators.

  10. A RONI Based Visible Watermarking Approach for Medical Image Authentication. (United States)

    Thanki, Rohit; Borra, Surekha; Dwivedi, Vedvyas; Borisagar, Komal


    Nowadays medical data in terms of image files are often exchanged between different hospitals for use in telemedicine and diagnosis. Visible watermarking being extensively used for Intellectual Property identification of such medical images, leads to serious issues if failed to identify proper regions for watermark insertion. In this paper, the Region of Non-Interest (RONI) based visible watermarking for medical image authentication is proposed. In this technique, to RONI of the cover medical image is first identified using Human Visual System (HVS) model. Later, watermark logo is visibly inserted into RONI of the cover medical image to get watermarked medical image. Finally, the watermarked medical image is compared with the original medical image for measurement of imperceptibility and authenticity of proposed scheme. The experimental results showed that this proposed scheme reduces the computational complexity and improves the PSNR when compared to many existing schemes.

  11. Security in Visible Light Communication: Novel Challenges and Opportunities

    Directory of Open Access Journals (Sweden)

    Christian ROHNER


    Full Text Available As LED lighting becomes increasingly ubiquitous, Visible Light Communication is attracting the interest of academia and industry as a complement to RF as the physical layer for the Internet of Things. Aside from its much greater spectral availability compared to RF, visible light has several attractive properties that may promote its uptake: its lack of health risks, its opportunities for spatial reuse, its relative immunity to multipath fading, its lack of electromagnetic interference, and its inherently secure nature: differently from RF, light does not penetrate through walls. In this paper, we outline the security implications of Visible Light Communication, review the existing contributions to this under-explored space, and survey the research opportunities that we envision for the near future.

  12. Robust Adaptive Photon Tracing using Photon Path Visibility

    DEFF Research Database (Denmark)

    Hachisuka, Toshiya; Jensen, Henrik Wann


    We present a new adaptive photon tracing algorithm which can handle illumination settings that are considered difficult for photon tracing approaches such as outdoor scenes, close-ups of a small part of an illuminated region, and illumination coming through a small gap. The key contribution in our...... algorithm is the use of visibility of photon path as the importance function which ensures that our sampling algorithm focuses on paths that are visible from the given viewpoint. Our sampling algorithm builds on two recent developments in Markov chain Monte Carlo methods: adaptive Markov chain sampling...... and replica exchange. Using these techniques, each photon path is adaptively mutated and it explores the sampling space efficiently without being stuck at a local peak of the importance function. We have implemented this sampling approach in the progressive photon mapping algorithm which provides visibility...

  13. MR-Visible Lipids and the Tumor Microenvironment (United States)

    Delikatny, E. James; Chawla, Sanjeev; Leung, Daniel-Joseph; Poptani, Harish


    MR-visible lipids or mobile lipids are defined as lipids that are observable using proton magnetic resonance spectroscopy in cells and in tissues. These MR-visible lipids are composed of triglycerides and cholesterol esters that accumulate in intracellular neutral lipid droplets, where their MR visibility is conferred as a result of the increased molecular motion available in this unique physical environment. This review will discuss factors that lead to the biogenesis of MR-visible lipids in cancer cells and in other cell types such as immune cells and fibroblasts. We focus on the accumulations of mobile lipids that are inducible in cultured cells by a number of stresses, including culture conditions and in response to activating stimuli or apoptotic cell death induced by anticancer drugs. This is compared with animal tumor models, where increases in mobile lipids are observed in response to chemo and radiotherapy, and to human tumors where mobile lipids are observed predominantly in high-grade brain tumors and in regions of necrosis. Conducive conditions for mobile lipid formation in the tumor microenvironment will be discussed including low pH, oxygen availability and the presence of inflammatory cells. It is concluded that MR-visible lipids appear in cancer cells and human tumors as a stress response. Mobile lipids stored as neutral lipid droplets may play a role in detoxification of the cell or act as an alternate energy source, especially in cancer cells, which often grow in ischemic/hypoxic environments. The role of MR-visible lipids in cancer diagnosis and assessment of treatment response both in animal models of cancer as well as human brain tumors will also be discussed. Although technical limitations exist in the accurate detection of intratumoral mobile lipids, early increases in mobile lipids after therapeutic interventions may be used as a potential biomarker for assessing treatment response in cancer. PMID:21538631

  14. Implementasi Visible Light Communication (VLC Pada Sistem Komunikasi

    Directory of Open Access Journals (Sweden)



    Full Text Available Abstrak Perkembangan teknologi telah menunjukkan peningkatan yang cukup signifikan, terutama untuk bidang komunikasi. Hal ini terbukti dengan banyaknya media komunikasi baik itu nirkabel dan kabel. Pada penelitian ini dimanfaatkan cahaya tampak sebagai media dalam sistem komunikasi, dimana selama ini cahaya hanya digunakan sebagai penerangan saja. Visible Light Communication (VLC adalah sebuah teknologi komunikasi yang memanfaatkan pancaran cahaya tampak dari lampu pada sistem komunikasi. Sistem komunikasi visible light ini terdiri dari pemancar dan penerima. Pemancar terdiri dari Light Emitting Dioda, audio transformator dan baterai, dan pada penerima terdiri dari solar cell dan photodioda, amplifier dan catu daya. Hal-hal yang dapat mempengaruhi hasil output sistem komunikasi adalah jarak, terang cahaya lampu pemancar dan cahaya luar. Pada penelitian ini, komunikasi menggunakan VLC dapat dilakukan pada jarak pengiriman data sebesar 2,5 m dan dengan range frekuensi 600 Hz sampai dengan 45 kHz dimana data dapat disalurkan dengan baik. Kata kunci: Visible light, Sistem komunikasi, Light Emitting Dioda, solar cell, photodioda. Abstract Technological developments have shown a significant increase, especially in the field of communication. This is proved by the many communications media using both wireless and wired. This study utilized the visible light as a medium of communication system, which has been used as an illumination light only. Visible Light Communication (VLC is a communication technology which utilize visible light emitted from the lamp in the communication system. The visible light communication system consists of a transmitter and receiver. The transmitter consists of a Light Emitting Diode, audio transformer and battery, and the receiver consists of a solar cell and a photodiode, amplifier and power supply. Things that can affect the output of the communication system is the distance, bright light and outdoor light. In the research

  15. Visibly transparent metal oxide diodes prepared by solution processing (United States)

    Chan, Kah-Yoong; Ng, Zi-Neng; Au, Benedict Wen-Cheun; Knipp, Dietmar


    Visibly transparent metal oxide diodes were fabricated using p-type doped zinc oxide on tin doped indium oxide coated substrates by sol-gel solution processing. The influence of various nitrogen doping concentration on the hole carrier concentration and the device operation of the diodes was investigated. The diodes exhibit high optical transmission in the visible spectra and high on/off ratios at low operating voltages. The operation is limited by the low hole carrier concentration, which affects the ideality factor and the series resistance of the diode. The influence of the carrier concentration on electronic properties of the diode will be discussed.

  16. Perceptions of a photograph of a woman with visible piercings. (United States)

    Martino, Sara


    To examine perceptions of people with visible piercings 105 undergraduate students from four different courses on campus (85 women, 20 men; M age=20.0 yr., SD=3.4) were randomly assigned to rate a photograph of a women with or without piercings on her eyebrow, ear, lip, and nose on 13 characteristics. Analysis indicated the model with visible piercings was rated less religious and more creative, artistic, and mysterious. These findings differ from previous findings on perception of tattoos. Implications and directions for research with different age groups are discussed.

  17. Race, Aging and Gay In/Visibility on US Television


    Johnson Jr., Michael


    In this chapter, I argue that despite the increased visibility of gay men on contemporary telenarratives (both on broadcast and cable networks)people of color remain stubbornly less visible and even within those examples of white gay men who dominate the airwaves, few if any depict men over the age of 40 or gay elders over the age of retirement.This invisibility operates a heuristic that pedagogically educates viewers to interpellate gay men as perpetually young or as young adults, thereby re...

  18. Dielectric-loaded plasmonic waveguide in the visible spectral range (United States)

    Melentiev, P. N.; Kuzin, A. A.; Balykin, V. I.; Ignatov, A. I.; Merzlikin, A. M.


    Dielectric-loaded surface plasmon‑polariton waveguides (DLSPPWs) are a practically valuable type of plasmonic waveguide. The properties of DLSPPWs at telecommunication wavelengths have been studied in detail. However, the efficient optical excitation of DLSPPWs in the visible spectral range has still not been realized. In this work, we present the results of our experimental investigations of DLSPPWs in the visible spectral range. In addition, a new configuration for the excitation and detection of the DLSPPW mode has been proposed and realized. The propagation of plasmon wave up to a distance of 45 µm in the DLSPPW has been demonstrated.

  19. High visibility two-photon interference with classical light. (United States)

    Hong, Peilong; Xu, Lei; Zhai, Zhaohui; Zhang, Guoquan


    Two-photon interference with independent classical sources, in which superposition of two indistinguishable two-photon paths plays a key role, is of limited visibility with a maximum value of 50%. By using a random-phase grating to modulate the wavefront of a coherent light, we introduce superposition of multiple indistinguishable two-photon paths, which enhances the two-photon interference effect with a signature of visibility exceeding 50%. The result shows the importance of phase control in the control of high-order coherence of classical light.

  20. Reflection beamshifts of visible light due to graphene (United States)

    Hermosa, Nathaniel


    I present calculations of reflection beamshifts, Goos-Hänchen and Imbert-Fedorov shifts, due to the presence of a graphene monolayer on a dielectric medium when using a beam with wavelength in the visible range. Measuring the Goos-Hänchen and Imbert-Fedorov shifts is an alternative method to determine graphene’s conductivity. I look at beamshifts for different polarization states (p, s, 450, {σ }+) and I discuss other possible experimental routes to determine these beamshifts and consequently, the graphene’s optical conductivity. The Goos-Hänchen shifts for visible light I calculated are in good agreement with results of a recent experiment.

  1. Systems and Methods for Automated Water Detection Using Visible Sensors (United States)

    Rankin, Arturo L. (Inventor); Matthies, Larry H. (Inventor); Bellutta, Paolo (Inventor)


    Systems and methods are disclosed that include automated machine vision that can utilize images of scenes captured by a 3D imaging system configured to image light within the visible light spectrum to detect water. One embodiment includes autonomously detecting water bodies within a scene including capturing at least one 3D image of a scene using a sensor system configured to detect visible light and to measure distance from points within the scene to the sensor system, and detecting water within the scene using a processor configured to detect regions within each of the at least one 3D images that possess at least one characteristic indicative of the presence of water.

  2. Physical parameters of the visible component of Cygnus X-1 (United States)

    Aab, O. E.; Bychkova, L. V.; Kopylov, I. M.; Kumajgorodskaya, R. N.


    The physical parameters of the supergiant HDE 226868, the visible component of Cygnus X-1, are refined by quantitative spectral methods from spectral material obtained on the six-meter telescope of the Special Astrophysical Observatory, USSR Academy of Sciences. The values of the spectral class, effective temperature, radius, luminosity, and acceleration of gravity are determined and their variation with the phase of the orbital period are revealed; the mass of the visible component of the system is determined as 37.6 + or - 1.5 solar masses and the rate of mass loss is estimated as (1.5 - 2) x 10 to the -6th solar mass/yr.

  3. 40 CFR 51.305 - Monitoring for reasonably attributable visibility impairment. (United States)


    ... visibility impairment. 51.305 Section 51.305 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Protection of Visibility § 51.305 Monitoring for reasonably attributable visibility impairment. (a) For the purposes of addressing reasonably attributable visibility impairment, each State containing a mandatory...

  4. Highly luminescent S, N co-doped graphene quantum dots with broad visible absorption bands for visible light photocatalysts (United States)

    Qu, Dan; Zheng, Min; Du, Peng; Zhou, Yue; Zhang, Ligong; Li, Di; Tan, Huaqiao; Zhao, Zhao; Xie, Zhigang; Sun, Zaicheng


    A facile hydrothermal synthesis route to N and S, N co-doped graphene quantum dots (GQDs) was developed by using citric acid as the C source and urea or thiourea as N and S sources. Both N and S, N doped GQDs showed high quantum yield (78% and 71%), excitation independent under excitation of 340-400 nm and single exponential decay under UV excitation. A broad absorption band in the visible region appeared in S, N co-doped GQDs due to doping with sulfur, which alters the surface state of GQDs. However, S, N co-doped GQDs show different color emission under excitation of 420-520 nm due to their absorption in the visible region. The excellent photocatalytic performance of the S, N co-doped GQD/TiO2 composites was demonstrated by degradation of rhodamine B under visible light. The apparent rate of S, N:GQD/TiO2 is 3 and 10 times higher than that of N:GQD/TiO2 and P25 TiO2 under visible light irradiation, respectively.A facile hydrothermal synthesis route to N and S, N co-doped graphene quantum dots (GQDs) was developed by using citric acid as the C source and urea or thiourea as N and S sources. Both N and S, N doped GQDs showed high quantum yield (78% and 71%), excitation independent under excitation of 340-400 nm and single exponential decay under UV excitation. A broad absorption band in the visible region appeared in S, N co-doped GQDs due to doping with sulfur, which alters the surface state of GQDs. However, S, N co-doped GQDs show different color emission under excitation of 420-520 nm due to their absorption in the visible region. The excellent photocatalytic performance of the S, N co-doped GQD/TiO2 composites was demonstrated by degradation of rhodamine B under visible light. The apparent rate of S, N:GQD/TiO2 is 3 and 10 times higher than that of N:GQD/TiO2 and P25 TiO2 under visible light irradiation, respectively. Electronic supplementary information (ESI) available: More XPS and UV-Vis spectra. See DOI: 10.1039/c3nr04402e

  5. Visibility and anonymity effects on attraction and group cohesiveness

    NARCIS (Netherlands)

    Lea, Martin; Spears, Russell; Watt, Susan E.


    This study investigated attraction and group cohesiveness under different visibility and anonymity conditions for social categories that differed in their capacity to be visually cued. Using computer-mediated communication in 36 mixed gender (visually cued category) and nationality (non-visually

  6. Red luminescence from ZnO : Cr nanophosphors under visible ...

    Indian Academy of Sciences (India)


    3+ nanophosphors under visible excitation. N PUSHPA1, M K KOKILA1,*, B M NAGABHUSHANA2, H NAGABHUSHANA3 and. A JAGANNATHA REDDY. 4 ... method at the temperature of 400°C. Powder X-ray diffraction results confirmed that Cr3+-doped and un- ... different transition metal dopants such as (Ni, Cr, Mn,.

  7. On measuring the visibility with motor-car headlighting.

    NARCIS (Netherlands)

    Boer, J.B. & Vermeulen, D.


    There is a distinct deference between American and European opinions about the most suitable beam pattern of motor-car headlights. The American point of view has been published in the Annexe to the Report 23b of the I.C.I. 1939 by H.M. Magdsick entitled: Some factors governing visibility distances

  8. Rainbow Visibility: How One Catholic University Responded to Intolerance. (United States)

    Getz, Cheryl; Kirkley, Evelyn A.


    When intolerance of gays and lesbians at the University of San Diego became a problem, a group of students, staff, and faculty decided to do something about it. The result was a project called Rainbow Visibility that works on many forms to educate the campus community. (Author)

  9. The Impact of Dark and Visible Fragmentation on Market Quality

    NARCIS (Netherlands)

    Degryse, H.; de Jong, F.; van Kervel, V.L.


    Two important characteristics of current equity markets are the large number of competing trading venues with publicly displayed order books and the substantial fraction of dark trading, which takes place outside such visible order books. This article evaluates the impact on liquidity of dark

  10. Comparison of registration techniques for GOES visible imagery data (United States)

    Tilton, James C.


    This paper briefly describes and then compares the effectiveness of five image registration approaches for GOES visible band imagery. The techniques compared are (1) NOAA "point" manual landmarking, (2) manual landmarking on extant feature (whole island, lake, etc.), (3) automatic phase correlation, (4) automatic spatial correlation on edge features, and (5) automatic spatial correlation of region boundaries derived from image segmentation.

  11. Visible Spectrum Circular Dichroism in Extrinsic Chirality Metamaterials

    CERN Document Server

    Lee, Seoungjun; Feng, Cheng; Jiao, Jiao; Khan, Ashfaq; Li, Lin


    We present the new planar extrinsic chirality metamaterial (ECM) design that manifests giant circular dichroism (CD) in the visible spectrum range rather than usual near-infrared and terahertz range. Effects of incident beam angles and meta-molecules unit sizes on the CD spectrums were theoretically analyzed; Physical mechanism was illustrated in new figures of asymmetrical current excitation in neighboring unit cells.

  12. Development of a Visible Spectrophotometric Method for the ...

    African Journals Online (AJOL)

    Purpose: To develop and validate a simple visible spectrophotometric method for the quantitative determination of ganciclovir in bulk sample and dosage form. Method: The method was based on the diazo coupling reaction between diazotized ganciclovir and acidified p-dimethylaminobenzaldehyde. Various analytical ...

  13. Enhancement of visible light irradiation photocatalytic activity of ...

    Indian Academy of Sciences (India)

    Mohamed Abdel Salam


    Sep 25, 2017 ... Yin D and Zhao F 2015 Visible-light-responsive sulfated vanadium-doped TS-1 with hollow structure: Enhanced photocatalytic activity in selective oxidation of cyclo- hexane J. Catal. 330 208. 11. Kim J, Ichikuni N, Hara T and Shimazu S 2016 Study on the selectivity of propane photo-oxidation reaction on.

  14. Using Polarization features of visible light for automatic landmine detection

    NARCIS (Netherlands)

    Jong, W. de; Schavemaker, J.G.M.


    This chapter describes the usage of polarization features of visible light for automatic landmine detection. The first section gives an introduction to land-mine detection and the usage of camera systems. In section 2 detection concepts and methods that use polarization features are described.

  15. Pangenesis: a common origin for visible and dark matter


    Volkas, Raymond R.


    The similar mass densities observed for visible and dark matter in the present-day universe suggest a common origin for both. A scheme called "pangenesis" for realising this using the Affleck-Dine mechanism in a baryon-symmetric universe is presented in this talk.

  16. Improved spring model-based collaborative indoor visible light positioning (United States)

    Luo, Zhijie; Zhang, WeiNan; Zhou, GuoFu


    Gaining accuracy with indoor positioning of individuals is important as many location-based services rely on the user's current position to provide them with useful services. Many researchers have studied indoor positioning techniques based on WiFi and Bluetooth. However, they have disadvantages such as low accuracy or high cost. In this paper, we propose an indoor positioning system in which visible light radiated from light-emitting diodes is used to locate the position of receivers. Compared with existing methods using light-emitting diode light, we present a high-precision and simple implementation collaborative indoor visible light positioning system based on an improved spring model. We first estimate coordinate position information using the visible light positioning system, and then use the spring model to correct positioning errors. The system can be employed easily because it does not require additional sensors and the occlusion problem of visible light would be alleviated. We also describe simulation experiments, which confirm the feasibility of our proposed method.

  17. A titanium nitride based metamaterial for applications in the visible

    DEFF Research Database (Denmark)

    Naik, Gururaj V.; Saha, Bivas; Liu, Jing


    Epitaxially grown TiN/Al0.6Sc0.4N superlattice behaves as a hyperbolic metamaterial (HMM) in the visible range. Since HMMs enhance photonic-density-of-states and reduce lifetime of an emitter, we observed nine times decrease in lifetime of a dye molecule placed close to this HMM. © 2013 The Optical...

  18. Visible Vowels : A Tool for the Visualization of Vowel Variation

    NARCIS (Netherlands)

    Heeringa, W.J.; Van de Velde, Hans


    This paper presents Visible Vowels, a web app that visualizes variation in f0, formants and duration. It combines user friend-liness with maximum functionality and flexibility, using a live plot view. See:

  19. 14 CFR 29.1321 - Arrangement and visibility. (United States)


    ... the vertical plane of the pilot's forward vision. In addition, for rotorcraft approved for IFR flight... and visibility. (a) Each flight, navigation, and powerplant instrument for use by any pilot must be... and line of vision when he is looking forward along the flight path. (b) Each instrument necessary for...

  20. 14 CFR 25.1321 - Arrangement and visibility. (United States)


    ... the vertical plane of the pilot's forward vision. In addition— (1) The instrument that most... and visibility. (a) Each flight, navigation, and powerplant instrument for use by any pilot must be... and line of vision when he is looking forward along the flight path. (b) The flight instruments...

  1. 14 CFR 23.1321 - Arrangement and visibility. (United States)


    ... so that any pilot seated at the controls can monitor the airplane's flight path and these instruments... the vertical plane of each required pilot's forward vision. In addition: (1) The instrument that most...: Installation § 23.1321 Arrangement and visibility. (a) Each flight, navigation, and powerplant instrument for...

  2. 46 CFR 72.04-1 - Navigation bridge visibility. (United States)


    ... visibility any blind sector caused by cargo, cargo gear, or other permanent obstruction must not exceed 5... gear, or other permanent obstruction must not exceed 10 degrees each, nor total more than 20 degrees... vertical plane, top out, at an angle of not less than 10 degrees and not more than 25 degrees. (3) The...

  3. 46 CFR 92.03-1 - Navigation bridge visibility. (United States)


    ... vessel. Within this arc of visibility any blind sector caused by cargo, cargo gear, or other permanent... beam caused by cargo, cargo gear, or other permanent obstruction must not exceed 10 degrees each, nor... windows are inclined from the vertical plane, top out, at an angle of not less than 10 degrees and not...

  4. 46 CFR 108.801 - Navigation bridge visibility. (United States)


    ... arc of visibility any blind sector caused by cargo, cargo gear, or other permanent obstruction must... caused by cargo, cargo gear, or other permanent obstruction must not exceed 10 degrees each, nor total... windows are inclined from the vertical plane, top out, at an angle of not less than 10 degrees and not...

  5. 46 CFR 190.02-1 - Navigation bridge visibility. (United States)


    ... arc of visibility any blind sector caused by cargo, cargo gear, or other permanent obstruction must... caused by cargo, cargo gear, or other permanent obstruction must not exceed 10 degrees each, nor total... are inclined from the vertical plane, top out, at an angle of not less than 10 degrees and not more...

  6. Integrating TEMPO and Its Analogues with Visible-Light Photocatalysis. (United States)

    Lang, Xianjun; Zhao, Jincai


    Visible light has risen to become a very important facilitator for selective radical reactions enabled by well-cognized photocatalysts. The renaissance of visible-light photocatalysis on this matter partly relies on integrating it with other fields of catalysis. In parallel, 2,2,6,6-tetramethylpiperidin N-oxide (TEMPO), a quintessential persistent radical, has a wide range of uses owing to its exceptional redox behavior, which gives rise to its latest prominence in catalysis. Therefore, integrating the catalysis of TEMPO with photocatalysis to perform visible-light-induced selective reactions becomes a very convenient marriage of merits. In this context, the integration of different types of photocatalysts, including metal complexes, metal-free organic dyes, and semiconductors, with TEMPO for outstanding organic transformations will be summarized. To expand further the catalytic repertoire, the integration of TEMPOH analogues such as NHPI (N-hydroxyphthalimide) and NHS (N-hydroxysuccinimide) with photocatalysis will also be discussed. Hopefully, these advances will pave the way for more breakthroughs by integrating TEMPO and its analogues with photocatalysis to lead to a valuable blueprint for visible-light-induced selective organic transformations. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Effect of visible range electromagnetic radiations on Escherichia coli ...

    African Journals Online (AJOL)

    Background: Escherichia coli is the agent responsible for a range of clinical diseases. With emerging antimicrobial resistance, other treatment options including solar/photo-therapy are becoming increasingly common. Visible Range Radiation Therapy/Colour Therapy is an emerging technique in the field of ...

  8. Development and validation of satellite based estimates of surface visibility


    Brunner, J.; R. B. Pierce; A. Lenzen


    A satellite based surface visibility retrieval has been developed using Moderate Resolution Imaging Spectroradiometer (MODIS) measurements as a proxy for Advanced Baseline Imager (ABI) data from the next generation of Geostationary Operational Environmental Satellites (GOES-R). The retrieval uses a multiple linear regression approach to relate satellite aerosol optical depth, fog/low cloud probability and thickness retrievals, and meteorol...

  9. Enhancement of visible light irradiation photocatalytic activity of ...

    Indian Academy of Sciences (India)

    SrTiO₃ and Pt/SrTiO₃ nanoparticles were characterized by XRD, XPS, TEM, BET surface area UV–Vis and PL techniques in order to explore their chemical and physical properties. The visible light irradiation photocatalyticperformances of SrTiO₃ nanoparticles and Pt/SrTiO₃ nanoparticles for photocatalytic oxidation of ...

  10. Development and validation of satellite based estimates of surface visibility (United States)

    Brunner, J.; Pierce, R. B.; Lenzen, A.


    A satellite based surface visibility retrieval has been developed using Moderate Resolution Imaging Spectroradiometer (MODIS) measurements as a proxy for Advanced Baseline Imager (ABI) data from the next generation of Geostationary Operational Environmental Satellites (GOES-R). The retrieval uses a multiple linear regression approach to relate satellite aerosol optical depth, fog/low cloud probability and thickness retrievals, and meteorological variables from numerical weather prediction forecasts to National Weather Service Automated Surface Observing System (ASOS) surface visibility measurements. Validation using independent ASOS measurements shows that the GOES-R ABI surface visibility retrieval (V) has an overall success rate of 64.5% for classifying Clear (V ≥ 30 km), Moderate (10 km ≤ V GOES-R ABI visibility retrieval can be used to augment measurements from the United States Environmental Protection Agency (EPA) and National Park Service (NPS) Interagency Monitoring of Protected Visual Environments (IMPROVE) network, and provide useful information to the regional planning offices responsible for developing mitigation strategies required under the EPA's Regional Haze Rule, particularly during regional haze events associated with smoke from wildfires.

  11. Visible light guided manipulation of liquid wettability on photoresponsive surfaces (United States)

    Kwon, Gibum; Panchanathan, Divya; Mahmoudi, Seyed Reza; Gondal, Mohammed A.; McKinley, Gareth H.; Varanasi, Kripa K.


    Photoresponsive titania surfaces are of great interest due to their unique wettability change upon ultraviolet light illumination. However, their applications are often limited either by the inability to respond to visible light or the need for special treatment to recover the original wettability. Sensitizing TiO2 surfaces with visible light-absorbing materials has been utilized in photovoltaic applications. Here we demonstrate that a dye-sensitized TiO2 surface can selectively change the wettability towards contacting liquids upon visible light illumination due to a photo-induced voltage across the liquid and the underlying surface. The photo-induced wettability change of our surfaces enables external manipulation of liquid droplet motion upon illumination. We show demulsification of surfactant-stabilized brine-in-oil emulsions via coalescence of brine droplets on our dye-sensitized TiO2 surface upon visible light illumination. We anticipate that our surfaces will have a wide range of applications including microfluidic devices with customizable wettability, solar-driven oil-water clean-up and demulsification technologies.

  12. Making Thinking Audible and Visible via Cooperative Learning (United States)

    Jacobs, George M.; Wang, Aili; Li, Xishuang; Xie, Yongye


    This chapter begins with a section that describes cooperative learning and explains eight cooperative learning principles. The second section looks briefly at why making thinking audible and visible enriches students' thinking. Making thinking audible means that teachers and students speak out what is going through their minds as they do a task,…

  13. The Visible Humans | NIH MedlinePlus the Magazine (United States)

    ... NLM who led the development of the Visible Human Project. "People around the world can and do use the images in a variety of ways. They have been used to help students learn anatomy; or to develop products like artificial limbs; or ...

  14. Mis asi on OÜ Visible Solutions? / Indrek Grigor

    Index Scriptorium Estoniae

    Grigor, Indrek


    Kunstiteos-ettevõtte OÜ Visible Solutions (juhatus: Sigrid Viir, Taaniel Raudsepp, Karel Koplimets) näitus "Adam Smithi Lemmik Nähtamatu Käsi Puuris" Tartu Kunstimajas 18. dets.-ni 2011. Kunstiprojekt firmast, mille tegevuse objekt on loomemajanduse kritiseerimine, mida tehakse viimase toimeloogika kunstiväljal eksponeerimise abil

  15. 40 CFR 52.29 - Visibility long-term strategies. (United States)


    ... of this part. (b) Definitions. For the purposes of this section, all terms shall have the meaning as ascribed to them in the Clean Air Act, or in the protection of visibility program (40 CFR 51.301). (c) Long... retrofit technology (BART) and meeting other schedules set forth in the long-term strategy; (vi) The impact...

  16. Speckle Contrast Reduction with a Visible VCSEL Projector


    Sabuncu,Metin; Yilmazlar,İsmail


    Speckle contrast reduction in a laser projector that has a VCSEL emitting in the visible spectrum as its light source can be achieved electronically. Employing a drive circuit enables exciting independent longitudinal modes of the VCSEL. By modulating the VCSEL current continuously with a triangular wave rather than with pulses, the speckle noise could be reduced.

  17. Seeing elements by visible-light digital camera. (United States)

    Zhao, Wenyang; Sakurai, Kenji


    A visible-light digital camera is used for taking ordinary photos, but with new operational procedures it can measure the photon energy in the X-ray wavelength region and therefore see chemical elements. This report describes how one can observe X-rays by means of such an ordinary camera - The front cover of the camera is replaced by an opaque X-ray window to block visible light and to allow X-rays to pass; the camera takes many snap shots (called single-photon-counting mode) to record every photon event individually; an integrated-filtering method is newly proposed to correctly retrieve the energy of photons from raw camera images. Finally, the retrieved X-ray energy-dispersive spectra show fine energy resolution and great accuracy in energy calibration, and therefore the visible-light digital camera can be applied to routine X-ray fluorescence measurement to analyze the element composition in unknown samples. In addition, the visible-light digital camera is promising in that it could serve as a position sensitive X-ray energy detector. It may become able to measure the element map or chemical diffusion in a multi-element system if it is fabricated with external X-ray optic devices. Owing to the camera's low expense and fine pixel size, the present method will be widely applied to the analysis of chemical elements as well as imaging.

  18. Seeing elements by visible-light digital camera (United States)

    Zhao, Wenyang; Sakurai, Kenji


    A visible-light digital camera is used for taking ordinary photos, but with new operational procedures it can measure the photon energy in the X-ray wavelength region and therefore see chemical elements. This report describes how one can observe X-rays by means of such an ordinary camera - The front cover of the camera is replaced by an opaque X-ray window to block visible light and to allow X-rays to pass; the camera takes many snap shots (called single-photon-counting mode) to record every photon event individually; an integrated-filtering method is newly proposed to correctly retrieve the energy of photons from raw camera images. Finally, the retrieved X-ray energy-dispersive spectra show fine energy resolution and great accuracy in energy calibration, and therefore the visible-light digital camera can be applied to routine X-ray fluorescence measurement to analyze the element composition in unknown samples. In addition, the visible-light digital camera is promising in that it could serve as a position sensitive X-ray energy detector. It may become able to measure the element map or chemical diffusion in a multi-element system if it is fabricated with external X-ray optic devices. Owing to the camera’s low expense and fine pixel size, the present method will be widely applied to the analysis of chemical elements as well as imaging. PMID:28361916

  19. Visible/Near Infrared Spectroscopic Method for the Prediction of ...

    African Journals Online (AJOL)

    The aim of the present study was to predict the potential of visible and near infrared (Vis/NIR) Spectroscopy in estimating the amount of lycopene in intact tomato. Eight tomato varieties from loose and cluster type were selected and harvested at commercial ripening stage for the study. The tomato cultivars were prepared ...

  20. Development of a Visible Spectrophotometric Method for the ...

    African Journals Online (AJOL)

    Abstract. Purpose: To develop and validate a simple visible spectrophotometric method for the quantitative determination of ... reliable alternative to the official method for the routine analysis of ganciclovir in bulk and dosage forms. Keywords: Ganciclovir .... absorbance reading was taken at 404 nm with methanol as blank.

  1. Skyglow effects in UV and visible spectra: Radiative fluxes (United States)

    Kocifaj, Miroslav; Solano Lamphar, Hector Antonio


    Several studies have tried to understand the mechanisms and effects of radiative transfer under different night-sky conditions. However, most of these studies are limited to the various effects of visible spectra. Nevertheless, the invisible parts of the electromagnetic spectrum can pose a more profound threat to nature. One visible threat is from what is popularly termed skyglow. Such skyglow is caused by injudiciously situated or designed artificial night lighting systems which degrade desired sky viewing. Therefore, since lamp emissions are not limited to visible electromagnetic spectra, it is necessary to consider the complete spectrum of such lamps in order to understand the physical behaviour of diffuse radiation at terrain level. In this paper, the downward diffuse radiative flux is computed in a two-stream approximation and obtained ultraviolet spectral radiative fluxes are inter-related with luminous fluxes. Such a method then permits an estimate of ultraviolet radiation if the traditionally measured illuminance on a horizontal plane is available. The utility of such a comparison of two spectral bands is shown, using the different lamp types employed in street lighting. The data demonstrate that it is insufficient to specify lamp type and its visible flux production independently of each other. Also the UV emissions have to be treated by modellers and environmental scientists because some light sources can be fairly important pollutants in the near ultraviolet. Such light sources can affect both the living organisms and ambient environment.

  2. Rock fracture image acquisition with both visible and ultraviolet illuminations (United States)

    Wang, Weixing; Hakami, Eva


    Swedish Nuclear Fuel and Waste Management Company (SKB) have identified the need for a better understanding of radionuclide transport and retention processes in fractured rock since 1994. In the study, the first hard problem is to obtain rock fracture images of a good quality, since rock surface is very rough, and composed of complicated and multiple fractures, as a result, image acquisition is the first important. As a cooperation project between Sweden and China, we sampled a number of rock specimens for analyzing rock fracture network by visible and ultraviolet image technique, in the field. The samples are resin injected, in which way; opened fractures can be seen clearly by means of UV light illumination, and the rock surface information can be obtained by using visible optical illumination. We used different digital cameras and microscope to take images by two illuminations. From the same samples; we found that UV illumination image gives the clear information of fracture opening or closing, and the visible optical illumination gives the information of the rock surface (e.g. filling materials inside of fractures). By applying this technique, the minimum width of rock fracture 0.01 mm can be analyzed. This paper presents: (1) Rock fracture image acquiring techniques; (2) Rock fracture image acquisition by using UV light illumination and visible optical illumination; and (3) Conclusions. The studied method can be used both in the field and a laboratory.

  3. The visibility of language ideologies: The linguistic landscapes of ...

    African Journals Online (AJOL)

    This paper explores the linguistic landscapes of the University of Yaoundé 1, Cameroon. The paper highlights the visibility of language ideologies. The main aim of this paper is to show how the language ideology of an institution or a community is reflected on its landscape. It therefore attempts to show how the language ...

  4. Solar photocatalytic generation of hydrogen under ultraviolet-visible ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 33; Issue 1. Solar photocatalytic generation of hydrogen under ultraviolet-visible light irradiation on (CdS/ZnS)/Ag2S + (RuO2/TiO2) photocatalysts. R Priya S Kanmani. Catalysis ... Keywords. Hydrogen; hydrogen sulfide; solar photocatalysis; composite; photocatalysts.

  5. 40 CFR 798.5200 - Mouse visible specific locus test. (United States)


    ... (and their negatives) demonstrating the visible mutations observed in mutant animals and the lack of.... Offspring are examined in the next generation for evidence that a new mutation has arisen. (3) Animal... animals shall be used. (iii) Number. A decision on the minimum number of treated animals should take into...

  6. Comparison between two visible biofilm indices in the primary dentition. (United States)

    dos Santos, Ana Paula Pires; Soviero, Vera Mendes


    The aim of this study was to compare two visible biofilm indices in the primary dentition. The sample consisted of 90 children of both sexes, aged up to 4 years old outpatients of the University Hospital of the Rio de Janeiro State University. A single examiner, aided by an assistant, performed the children's dental examination for biofilm assessment. A simplified visible biofilm index (BF1), which classifies biofilm as absent, thin or thick, in anterior and/or posterior teeth, and provides a score for the patient and not for each tooth, was compared to a conventional visible biofilm index, the visible plaque index, (BF2), which classifies biofilm as absent or present and provides scores for three surfaces of each tooth. A statistically significant association and a strong positive correlation between BF1 and BF2 was found (Kruskal-Wallis p biofilm index is feasible in the primary dentition as it showed similar findings when compared to a conventional one, besides being more practical and quicker.

  7. Circulating Power and In/Visibility: Layers of Educational Leadership (United States)

    Mifsud, Denise


    Purpose: The purpose of this paper is to study circulating power and in/visibility. In the unfolding Maltese education scenario of decentralization and school networking, suffused with entrenched power, with added layers of leadership and more subtle levels of accountability, this paper explores the underlying power relations among the top…

  8. Visible light photocatalytic properties of novel molybdenum treated ...

    Indian Academy of Sciences (India)

    Visible light photocatalytic properties of novel molybdenum treated carbon nanotube/titania composites. FENG-JUN ZHANG† and WON-CHUN OH. ∗. School of Materials and Chemical Engineering, Anhui University of Architecture, Anhui Hefei 230022,. P. R. China. †Department of Advanced Materials & Engineering, ...

  9. Visible-near-infrared luminescent lanthanide ternary complexes based on beta-diketonate using visible-light excitation. (United States)

    Sun, Lining; Qiu, Yannan; Liu, Tao; Feng, Jing; Deng, Wei; Shi, Liyi


    We used the synthesized dinaphthylmethane (Hdnm) ligand whose absorption extends to the visible-light wavelength, to prepare a family of ternary lanthanide complexes, named as [Ln(dnm)3 phen] (Ln = Sm, Nd, Yb, Er, Tm, Pr). The properties of these complexes were investigated by Fourier transform infrared (FT-IR) spectroscopy, diffuse reflectance (DR) spectroscopy, thermogravimetric analyses, and excitation and emission spectroscopy. Generally, excitation with visible light is much more advantageous than UV excitation. Importantly, upon excitation with visible light (401-460 nm), the complexes show characteristic visible (Sm(3+)) as well as near-infrared (Sm(3+), Nd(3+), Yb(3+), Er(3+), Tm(3+), Pr(3+)) luminescence of the corresponding lanthanide ions, attributed to the energy transfer from the ligands to the lanthanide ions, an antenna effect. Now, using these near-infrared luminescent lanthanide complexes, the luminescent spectral region from 800 to 1650 nm, can be covered completely, which is of particular interest for biomedical imaging applications, laser systems, and optical amplification applications. Copyright © 2015 John Wiley & Sons, Ltd.

  10. Indoor visible light communication with smart lighting technology (United States)

    Das Barman, Abhirup; Halder, Alak


    An indoor visible-light communication performance is investigated utilizing energy efficient white light by 2D LED arrays. Enabled by recent advances in LED technology, IEEE 802.15.7 standardizes high-data-rate visible light communication and advocates for colour shift keying (CSK) modulation to overcome flicker and to support dimming. Voronoi segmentation is employed for decoding N-CSK constellation which has superior performance compared to other existing decoding methods. The two chief performance degrading effects of inter-symbol interference and LED nonlinearity is jointly mitigated using LMS post equalization at the receiver which improves the symbol error rate performance and increases field of view of the receiver. It is found that LMS post equalization symbol at 250MHz offers 7dB SNR improvement at SER10-6

  11. Multi-Sensor Person Following in Low-Visibility Scenarios

    Directory of Open Access Journals (Sweden)

    Javier Pérez


    Full Text Available Person following with mobile robots has traditionally been an important research topic. It has been solved, in most cases, by the use of machine vision or laser rangefinders. In some special circumstances, such as a smoky environment, the use of optical sensors is not a good solution. This paper proposes and compares alternative sensors and methods to perform a person following in low visibility conditions, such as smoky environments in firefighting scenarios. The use of laser rangefinder and sonar sensors is proposed in combination with a vision system that can determine the amount of smoke in the environment. The smoke detection algorithm provides the robot with the ability to use a different combination of sensors to perform robot navigation and person following depending on the visibility in the environment.

  12. Making Heat Visible: Promoting Energy Conservation Behaviors Through Thermal Imaging. (United States)

    Goodhew, Julie; Pahl, Sabine; Auburn, Tim; Goodhew, Steve


    Householders play a role in energy conservation through the decisions they make about purchases and installations such as insulation, and through their habitual behavior. The present U.K. study investigated the effect of thermal imaging technology on energy conservation, by measuring the behavioral effect after householders viewed images of heat escaping from or cold air entering their homes. In Study 1 (n = 43), householders who received a thermal image reduced their energy use at a 1-year follow-up, whereas householders who received a carbon footprint audit and a non-intervention control demonstrated no change. In Study 2 (n = 87), householders were nearly 5 times more likely to install draught proofing measures after seeing a thermal image. The effect was especially pronounced for actions that addressed an issue visible in the images. Findings indicate that using thermal imaging to make heat loss visible can promote energy conservation.

  13. Enhanced photoresponse towards visible light in Ru doped titania nanotube

    Energy Technology Data Exchange (ETDEWEB)

    Khan, M. Alam [School of Semiconductor and Chemical Engineering and Solar Energy Research Center, Chonbuk National University, 664-14 Dukjin dong, 1Ga, Jeonju 719-756 (Korea, Republic of); School of Display and Chemical Engineering, Yeungnam University, 214-1 Dae-Dong, Gyeongsan 712-749 (Korea, Republic of); Han, Do Hung [School of Display and Chemical Engineering, Yeungnam University, 214-1 Dae-Dong, Gyeongsan 712-749 (Korea, Republic of); Yang, O.-Bong [School of Semiconductor and Chemical Engineering and Solar Energy Research Center, Chonbuk National University, 664-14 Dukjin dong, 1Ga, Jeonju 719-756 (Korea, Republic of)], E-mail:


    Doping of ruthenium by the ion exchange method to the hydrothermally synthesized titania nanotube (TiNT) was found to be an effective photocatalyst active under visible light for methylene blue dye decoloration. The well dispersed and well embedded ionized ruthenium particles of about {approx}2-4 nm significantly reduced the band gap energy of synthesized TiNTs from 3.1 eV to 2.56 eV in (Ru(IE)/TiNT). The loading method, size of ruthenium particles and metal dispersion pattern at the nanotube textures have great influence on its photocatalytic performances exhibiting higher photocatalytic activity (>80%) of methylene blue dye. However, large aggregated ruthenium particles (sizes {approx}12-60 nm) on Ru(IM)/TiNT prepared by impregnation method failed to respond in visible light. The prepared catalysts were analysed by TEM, FESEM, FE-SEMEDX, XRD, UV-vis DRS spectra, XPS and BET surface area techniques.

  14. A fast, visible-light-sensitive azobenzene for bioorthogonal ligation. (United States)

    Poloni, Claudia; Szymański, Wiktor; Hou, Lili; Browne, Wesley R; Feringa, Ben L


    Azobenzenes have been used as photoresponsive units for the control of numerous biological processes. Primary prerequisites for such applications are site-selective incorporation of photoswitchable units into biomolecules and the possibility of using non-destructive and deep-tissue-penetrating visible light for the photoisomerization. Here we report a push-pull azobenzene that readily undergoes a Staudinger-Bertozzi ligation with azide groups, that can be addressed with visible light (>440 nm) and exhibits the solvato- and acidochromism typical for push-pull systems. The thermal relaxation in aqueous environment proceeds on the low-millisecond timescale, thus enabling control over biological processes on similar timescales. The approach is demonstrated in the modification of a quartz surface and in the incorporation of an azobenzene unit into a functional peptide, the third zinc finger in the mammalian factor Sp1. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Heterogeneous visible light photocatalysis for selective organic transformations. (United States)

    Lang, Xianjun; Chen, Xiaodong; Zhao, Jincai


    The future development of chemistry entails environmentally friendly and energy sustainable alternatives for organic transformations. Visible light photocatalysis can address these challenges, as reflected by recent intensive scientific endeavours to this end. This review covers state-of-the-art accomplishments in visible-light-induced selective organic transformations by heterogeneous photocatalysis. The discussion comprises three sections based on the photocatalyst type: metal oxides such as TiO2, Nb2O5 and ZnO; plasmonic photocatalysts like nanostructured Au, Ag or Cu supported on metal oxides; and polymeric graphitic carbon nitride. Finally, recent strides in bridging the gap between photocatalysis and other areas of catalysis will be highlighted with the aim of overcoming the existing limitations of photocatalysis by developing more creative synthetic methodologies.

  16. Does a Graphical Abstract Bring More Visibility to Your Paper?

    Directory of Open Access Journals (Sweden)

    Eva-Maria Pferschy-Wenzig


    Full Text Available A graphical abstract (GA represents a piece of artwork that is intended to summarize the main findings of an article for readers at a single glance. Many publishers currently encourage authors to supplement their articles with GAs, in the hope that such a convenient visual summary will facilitate readers with a clearer outline of papers that are of interest and will result in improved overall visibility of the respective publication. To test this assumption, we statistically compared publications with or without GA published in Molecules between March 2014 and March 2015 with regard to several output parameters reflecting visibility. Contrary to our expectations, manuscripts published without GA performed significantly better in terms of PDF downloads, abstract views, and total citations than manuscripts with GA. To the best of our knowledge, this is the first empirical study on the effectiveness of GA for attracting attention to scientific publications.

  17. Photocatalytic Degradation of Thiram (Fungicides under Visible Light Irradiation

    Directory of Open Access Journals (Sweden)

    Sanjay R. Thakare


    Full Text Available Pesticides in the different form are toxic to the environment and removal of its form the various sources is a difficult task. The thiram undergoes photocatalytic degradation under visible light when prepared TiO2∼PVA polymer composite was used as a photocatalyst. The data represent that prepared TiO2∼PVA polymer composite is a more efficient photocatalyst than the neat TiO2. Photocatalytic efficiency of prepared TiO2∼PVA polymer composite was measured in term of no adsorption of pollutant, higher degradation rate and act as a photocatalyst under visible light irradiation. 150 minutes are required for the complete degradation of the thiram. The end products of photocatalytic degradation of thiram are CO2, nitrate and sulphate.

  18. Domesticating Visibility. The Chinese Internet between Labor and Praxis

    Directory of Open Access Journals (Sweden)

    Allan BAHROUN


    Full Text Available The less we question the technical and semiotic properties of the so-called social media, the more oblivious we remain to their political agency. The media transformations, which occurred in China at incredible speed and depth, must lead us to question the ways in which ‘new media’ affect the sites and forms of power. This article offers a reading into the economic and theoretical dynamics of what is commonly referred to as the ‘Chinese Internet’. Its history is marked by strategic attempts to shape, constrain and leverage social visibility. Thus, the author uses the notion of computerized media and invokes Hannah Arendt’s conception of visibility to describe what appears in China to be a new form of globalized media capitalism.

  19. Multipath Reflections Analysis on Indoor Visible Light Positioning System

    CERN Document Server

    Gu, Wenjun; Kavehrad, Mohsen


    Visible light communication (VLC) has become a promising research topic in recent years, and finds its wide applications in indoor environments. Particularly, for location based services (LBS), visible light also provides a practical solution for indoor positioning. Multipath-induced dispersion is one of the major concerns for complex indoor environments. It affects not only the communication performance but also the positioning accuracy. In this paper, we investigate the impact of multipath reflections on the positioning accuracy of indoor VLC positioning systems. Combined Deterministic and Modified Monte Carlo (CDMMC) approach is applied to estimate the channel impulse response considering multipath reflections. Since the received signal strength (RSS) information is used for the positioning algorithm, the power distribution from one transmitter in a typical room configuration is first calculated. Then, the positioning accuracy in terms of root mean square error is obtained and analyzed.

  20. Rechargeable solid state neutron detector and visible radiation indicator (United States)

    Stowe, Ashley C.; Wiggins, Brenden; Burger, Arnold


    A radiation detection device, including: a support structure; and a chalcopyrite crystal coupled to the support structure; wherein, when the chalcopyrite crystal is exposed to radiation, a visible spectrum of the chalcopyrite crystal changes from an initial color to a modified color. The visible spectrum of the chalcopyrite crystal is changed back from the modified color to the initial color by annealing the chalcopyrite crystal at an elevated temperature below a melting point of the chalcopyrite crystal over time. The chalcopyrite crystal is optionally a .sup.6LiInSe.sub.2 crystal. The radiation is comprised of neutrons that decrease the .sup.6Li concentration of the chalcopyrite crystal via a .sup.6Li(n,.alpha.) reaction. The initial color is yellow and the modified color is one of orange and red. The annealing temperature is between about 450 degrees C. and about 650 degrees C. and the annealing time is between about 12 hrs and about 36 hrs.

  1. Visible-Light-Activated Bactericidal Functions of Carbon "Quantum" Dots. (United States)

    Meziani, Mohammed J; Dong, Xiuli; Zhu, Lu; Jones, Les P; LeCroy, Gregory E; Yang, Fan; Wang, Shengyuan; Wang, Ping; Zhao, Yiping; Yang, Liju; Tripp, Ralph A; Sun, Ya-Ping


    Carbon dots, generally defined as small carbon nanoparticles with various surface passivation schemes, have emerged as a new class of quantum-dot-like nanomaterials, with their optical properties and photocatalytic functions resembling those typically found in conventional nanoscale semiconductors. In this work, carbon dots were evaluated for their photoinduced bactericidal functions, with the results suggesting that the dots were highly effective in bacteria-killing with visible-light illumination. In fact, the inhibition effect could be observed even simply under ambient room lighting conditions. Mechanistic implications of the results are discussed and so are opportunities in the further development of carbon dots into a new class of effective visible/natural light-responsible bactericidal agents for a variety of bacteria control applications.

  2. Visible light laser voltage probing on thinned substrates (United States)

    Beutler, Joshua; Clement, John Joseph; Miller, Mary A.; Stevens, Jeffrey; Cole, Jr., Edward I.


    The various technologies presented herein relate to utilizing visible light in conjunction with a thinned structure to enable characterization of operation of one or more features included in an integrated circuit (IC). Short wavelength illumination (e.g., visible light) is applied to thinned samples (e.g., ultra-thinned samples) to achieve a spatial resolution for laser voltage probing (LVP) analysis to be performed on smaller technology node silicon-on-insulator (SOI) and bulk devices. Thinning of a semiconductor material included in the IC (e.g., backside material) can be controlled such that the thinned semiconductor material has sufficient thickness to enable operation of one or more features comprising the IC during LVP investigation.

  3. Thermal-to-visible face recognition using multiple kernel learning (United States)

    Hu, Shuowen; Gurram, Prudhvi; Kwon, Heesung; Chan, Alex L.


    Recognizing faces acquired in the thermal spectrum from a gallery of visible face images is a desired capability for the military and homeland security, especially for nighttime surveillance and intelligence gathering. However, thermal-tovisible face recognition is a highly challenging problem, due to the large modality gap between thermal and visible imaging. In this paper, we propose a thermal-to-visible face recognition approach based on multiple kernel learning (MKL) with support vector machines (SVMs). We first subdivide the face into non-overlapping spatial regions or blocks using a method based on coalitional game theory. For comparison purposes, we also investigate uniform spatial subdivisions. Following this subdivision, histogram of oriented gradients (HOG) features are extracted from each block and utilized to compute a kernel for each region. We apply sparse multiple kernel learning (SMKL), which is a MKLbased approach that learns a set of sparse kernel weights, as well as the decision function of a one-vs-all SVM classifier for each of the subjects in the gallery. We also apply equal kernel weights (non-sparse) and obtain one-vs-all SVM models for the same subjects in the gallery. Only visible images of each subject are used for MKL training, while thermal images are used as probe images during testing. With subdivision generated by game theory, we achieved Rank-1 identification rate of 50.7% for SMKL and 93.6% for equal kernel weighting using a multimodal dataset of 65 subjects. With uniform subdivisions, we achieved a Rank-1 identification rate of 88.3% for SMKL, but 92.7% for equal kernel weighting.

  4. An Improved Infrared/Visible Fusion for Astronomical Images

    Directory of Open Access Journals (Sweden)

    Attiq Ahmad


    Full Text Available An undecimated dual tree complex wavelet transform (UDTCWT based fusion scheme for astronomical visible/IR images is developed. The UDTCWT reduces noise effects and improves object classification due to its inherited shift invariance property. Local standard deviation and distance transforms are used to extract useful information (especially small objects. Simulation results compared with the state-of-the-art fusion techniques illustrate the superiority of proposed scheme in terms of accuracy for most of the cases.

  5. Hexaarylbiimidazoles as Visible Light Thiol–Ene Photoinitiators (United States)

    Clarkson, Brian H.; Scott, Timothy F.


    Objectives The aim of this study is to determine if hexaarylbiimidazoles (HABIs) are efficient, visible light-active photoinitiators for thiol–ene systems. We hypothesize that, owing to the reactivity of lophyl radicals with thiols and the necessarily high concentration of thiol in thiol–ene formulations, HABIs will effectively initiate thiol–ene polymerization upon visible light irradiation. Methods UV-vis absorption spectra of photoinitiator solutions were obtained using UV-vis spectroscopy, while EPR spectroscopy was used to confirm radical species generation upon HABI photolysis. Functional group conversions during photopolymerization were monitored using FTIR spectroscopy, and thermomechanical properties were determined using dynamic mechanical analysis. Results The HABI derivatives investigated exhibit less absorptivity than camphorquinone at 469 nm; however, they afford increased sensitivity at this wavelength when compared with bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide. Photolysis of the investigated HABIs affords lophyl radicals. Affixing hydroxyhexyl functional groups to the HABI core significantly improved solubility. Thiol–ene resins formulated with HABI photoinitiators polymerized rapidly upon irradiation with 469 nm. The glass transition temperatures of the thiol–ene resin formulated with a bis(hydroxyhexyl)-functionalized HABI and photopolymerized at room and body temperature were 49.5±0.5°C and 52.2±0.1°C, respectively. Significance Although thiol–enes show promise as continuous phases for composite dental restorative materials, they show poor reactivity with the conventional camphorquinone/tertiary amine photoinitiation system. Conversely, despite their relatively low visible light absorptivity, HABI photoinitiators afford rapid thiol–ene photopolymerization rates. Moreover, minor structural modifications suggest pathways for improved HABI solubility and visible light absorption. PMID:26119702

  6. The effect of visibility of environmental friendliness in hotels


    Hernesniemi, Maria


    This research studies the visibility of environmental friendliness in the hotel industry and whether or not it can have a positive effect, especially with profitability. Two local hotels from Helsinki are included as practical examples, Scandic Marski and Best Western Premier Hotel Katajanokka. The research is conducted using both quantitative and qualitative research methods as well as literature review. Close ended questionnaires were sent out to two case hotels and Scandic Marski Front Off...

  7. Very short range forecasts of visibility and ceiling (United States)

    Hilsenrod, A.


    The development of methods for the short range forecasting of visibility and ceiling conditions is discussed. Short range forecasts of one hour or less (5 or 30 minutes), immediately after a series of local observations can be expected to be more accurate and reliable than any forecast of more than one hour. These forecasts can be accomplished by the operational implementation of fully automated aviation observation systems and the utilization of statistical techniques such as the Generalized Equivalent Markov model.

  8. Making design pedagogical content knowledge visible within design reviews


    Adams, Robin; Radcliffe, David; Forin, Tiago; Chua, Mel


    Design pedagogical content knowledge (PCK) is the content-specific specialized teacher knowledge that connects the how (pedagogical knowledge) and what (content knowledge) of teaching design. In this study, we make visible the design PCK in three student design reviews: choreography, undergraduate industrial design, and mechanical engineering. We use cognitive apprenticeship and teaching-as-improvisation frameworks to characterize PK, and design judgment, design task strategies, and process m...

  9. El desarrollo de las emociones haciendo el pensamiento visible


    Cascales Ribera, María del Carmen


    El presente Trabajo Final de Grado (TFG) permite desarrollar la competencia emocional del alumnado de Educación Primaria haciendo el pensamiento visible a través de rutinas de pensamiento. El presente TFG presenta un programa de actividades educativas relativas al área de educación emocional, que permite manejar las propias emociones, reconocer las emociones en los demás y establecer relaciones. Educación Psicología

  10. Thermal-Polarimetric and Visible Data Collection for Face Recognition (United States)


    capability, a database of simultaneously acquired thermal and visible face imagery is needed to support the development of multimodal face recognition...passed to the FPA changes. “In its principle mode of operation, the system acquires a set of 16 images per rotation of the λ/2 retarder. Images are...Byrd KA Preview of the newly acquired NVESD-ARL multimodal face database. Proc SPIE DSS. 2013;8734. 10. Yuffa AJ, Gurton KP, Videen G. Appl Optics

  11. Integrated Visible Photonics for Trapped-Ion Quantum Computing (United States)


    necessarily reflect the views of the Department of Defense. Abstract- A scalable trapped-ion-based quantum- computing architecture requires the...span the visible and near IR spectrum. Further, a scalable trap architecture requires many (thousands to millions of) ions in close proximity to one...silicon nitride separated by a 2-µm oxide gap. The platform is similar in structure to those demonstrated by others for 1550 nm operation [2], but here

  12. Visible and ultraviolet light sources based nonlinear interaction of lasers

    DEFF Research Database (Denmark)

    Andersen, Martin Thalbitzer; Tidemand-Lichtenberg, Peter; Jain, Mayank

    Different light sources can be used for optically stimulated luminescence measurements and usually a halogen lamp in combination with filters or light emitting diodes (LED’s) are used to provide the desired stimulation wavelength. However lasers can provide a much more well-defined beam, very...... for synthesizing any wavelength in the visible and ultraviolet light based sum frequency generation between two lasers is presented....

  13. Kanter revisited: Gender, power and (in)visibility


    Lewis, P.; Simpson, R


    This is the accepted version of the following article: Lewis, P. and Simpson, R. (2012), Kanter Revisited: Gender, Power and (In)Visibility. International Journal of Management Reviews, 14: 141–158., which has been published in final form at This paper revisits Kanter's (1977) seminal work Men and Women of the Corporation, rereading her account of numerical advantage and disadvantage through a poststructuralist l...

  14. Visible light scatter as quantitative information source on milk constituents

    DEFF Research Database (Denmark)

    Melentieva, Anastasiya; Kucheryavskiy, Sergey; Bogomolov, Andrey


    VISIBLE LIGHT SCATTER AS A QUANTITATIVE INFORMATION SOURCE ON MILK CONSTITUENTS A. Melenteva 1, S. Kucheryavski 2, A. Bogomolov 1,31Samara State Technical University, Molodogvardeyskaya Street 244, 443100 Samara, Russia. 2Aalborg University, campus Esbjerg, Niels Bohrs vej 8, 6700 Esbjerg, Denmar...... research area are presented and discussed. References: [1] A. Bogomolov, S. Dietrich, B. Boldrini, R.W. Kessler, Food Chemistry (2012), doi:10.1016/j.foodchem.2012.02.077....

  15. Long-Term Trends in Visibility and at Chengdu, China (United States)

    Wang, Qiyuan; Cao, Junji; Tao, Jun; Li, Nan; Su, Xiaoli; Chen, L. W. Antony; Wang, Ping; Shen, Zhenxing; Liu, Suixin; Dai, Wenting


    Long-term (1973 to 2010) trends in visibility at Chengdu, China were investigated using meteorological data from the U.S. National Climatic Data Center. The visual range exhibited a declining trend before 1982, a slight increase between 1983 and 1995, a sharp decrease between 1996 and 2005, and some improvements after 2006. The trends in visibility were generally consistent with the economic development and implementation of pollution controls in China. Intensive PM2.5 measurements were conducted from 2009 to 2010 to determine the causes of visibility degradation. An analysis based on a modification of the IMPROVE approach indicated that PM2.5 ammonium bisulfate contributed 27.7% to the light extinction coefficient (bext); this was followed by organic mass (21.7%), moisture (20.6%), and ammonium nitrate (16.3%). Contributions from elemental carbon (9.4%) and soil dust (4.3%) were relatively minor. Anthropogenic aerosol components (sulfate, nitrate, and elemental carbon) and moisture at the surface also were important determinants of the aerosol optical depth (AOD) at 550 nm, and the spatial distributions of both bext and AOD were strongly affected by regional topography. A Positive Matrix Factorization receptor model suggested that coal combustion was the largest contributor to PM2.5 mass (42.3%) and the dry-air light-scattering coefficient (47.7%); this was followed by vehicular emissions (23.4% and 20.5%, respectively), industrial emissions (14.9% and 18.8%), biomass burning (12.8% and 11.9%), and fugitive dust (6.6% and 1.1%). Our observations provide a scientific basis for improving visibility in this area. PMID:23874802

  16. Long-term trends in visibility and at Chengdu, China.

    Directory of Open Access Journals (Sweden)

    Qiyuan Wang

    Full Text Available Long-term (1973 to 2010 trends in visibility at Chengdu, China were investigated using meteorological data from the U.S. National Climatic Data Center. The visual range exhibited a declining trend before 1982, a slight increase between 1983 and 1995, a sharp decrease between 1996 and 2005, and some improvements after 2006. The trends in visibility were generally consistent with the economic development and implementation of pollution controls in China. Intensive PM2.5 measurements were conducted from 2009 to 2010 to determine the causes of visibility degradation. An analysis based on a modification of the IMPROVE approach indicated that PM2.5 ammonium bisulfate contributed 27.7% to the light extinction coefficient (bext ; this was followed by organic mass (21.7%, moisture (20.6%, and ammonium nitrate (16.3%. Contributions from elemental carbon (9.4% and soil dust (4.3% were relatively minor. Anthropogenic aerosol components (sulfate, nitrate, and elemental carbon and moisture at the surface also were important determinants of the aerosol optical depth (AOD at 550 nm, and the spatial distributions of both bext and AOD were strongly affected by regional topography. A Positive Matrix Factorization receptor model suggested that coal combustion was the largest contributor to PM2.5 mass (42.3% and the dry-air light-scattering coefficient (47.7%; this was followed by vehicular emissions (23.4% and 20.5%, respectively, industrial emissions (14.9% and 18.8%, biomass burning (12.8% and 11.9%, and fugitive dust (6.6% and 1.1%. Our observations provide a scientific basis for improving visibility in this area.

  17. Performance Analysis of Visible Light Communication Using CMOS Sensors. (United States)

    Do, Trong-Hop; Yoo, Myungsik


    This paper elucidates the fundamentals of visible light communication systems that use the rolling shutter mechanism of CMOS sensors. All related information involving different subjects, such as photometry, camera operation, photography and image processing, are studied in tandem to explain the system. Then, the system performance is analyzed with respect to signal quality and data rate. To this end, a measure of signal quality, the signal to interference plus noise ratio (SINR), is formulated. Finally, a simulation is conducted to verify the analysis.

  18. A possible mechanism for visible light-induced wound healing. (United States)

    Lipovsky, Anat; Nitzan, Yeshayahu; Lubart, Rachel


    Chronic wounds resistant to conventional therapy have been treated successfully with low energy lasers and light emitting diodes (LEDs) in the visible and near IR region. It has been proposed that production of low level reactive oxygen species (ROS) following illumination is the first step of photobiomodulation. It was also shown that white light (400-800 nm) has similar stimulatory effects as lasers and LEDs. ROS at higher levels are toxic to cells and bacteria. In the present study, we examined the phototoxicity of broadband (400-800 nm, 120 J/cm(2)) visible light on the survival of several pathogenic bacteria: Staphylococcus aureus 195, Pseudomonas aeruginosa 1316, Escherichia coli 1313, and Serratia marcescens. These bacteria were chosen due to their high prevalence in infected wounds. The survival of bacterial cells following illumination was monitored by counting the number of colony forming units before and after exposure to light. Illumination with white light, 120 J/cm(2), caused a reduction of 62%, 83%, and 56% in the colony count of E. coli 1313, S. aureus 195 and S. marcescens, respectively, though no reduction in the viability of P. aeruginosa 1316 was demonstrated. The phototoxic effect was found to involve induction of ROS production by the bacteria. It was also found that illumination of S. aureus 195 and E. coli 1313 in the presence of pyocyanin, known to be secreted by P. aeruginosa, had a stronger bactericidal effect compared to illumination alone. Visible light at high intensity can kill bacteria in infected wounds. Thus, illumination of infected wounds with intense visible light, prior to low intensity illumination for stimulating wound closure, may reduce infection and promote healing.

  19. An Adaptive and Hybrid Approach for Revisiting the Visibility Pipeline

    Directory of Open Access Journals (Sweden)

    Ícaro Lins Leitão da Cunha


    Full Text Available We revisit the visibility problem, which is traditionally known in Computer Graphics and Vision fields as the process of computing a (potentially visible set of primitives in the computational model of a scene. We propose a hybrid solution that uses a dry structure (in the sense of data reduction, a triangulation of the type J1a, to accelerate the task of searching for visible primitives. We came up with a solution that is useful for real-time, on-line, interactive applications as 3D visualization. In such applications the main goal is to load the minimum amount of primitives from the scene during the rendering stage, as possible. For this purpose, our algorithm executes the culling by using a hybrid paradigm based on viewing-frustum, back-face culling and occlusion models. Results have shown substantial improvement over these traditional approaches if applied separately. This novel approach can be used in devices with no dedicated processors or with low processing power, as cell phones or embedded displays, or to visualize data through the Internet, as in virtual museums applications.


    Directory of Open Access Journals (Sweden)

    Avram Daniel


    Full Text Available Romania has a remarkable natural heritage, with landscapes that are unique in the world and with villages still preserving the habits and traditions unaltered. Country’s potential for the practising the rural tourism is high, with fair chances of transforming villages that are less visible at the international level into actual emblematic destinations. As the urban pollution and organisational stress rise, the vacations in the rural area may be a plausible way of reinvigorating the spirit. However, the lack of visibility of the Romanian destinations requires that new promoting methods be identified. By the quality analysis carried out by the author in this article, new ways to increase the Romanian tourism visibility and to attract new tourists are argued. Aspects such as promotion by art, by thematic museums, with the help of opinion makers or by means of popular literature pieces have been considered. Thus, the potential methods of promoting the authentic Romanian village have been identified, assuming that each reference in the foreign press, cinema or other communication channel must be identified and exploited for the benefit of the Romanian tourism

  1. Comparison of visibility measurement techniques for forklift truck design factors. (United States)

    Choi, Chin-Bong; Park, Peom; Kim, Young-Ho; Susan Hallbeck, M; Jung, Myung-Chul


    This study applied the light bulb shadow test, a manikin vision assessment test, and an individual test to a forklift truck to identify forklift truck design factors influencing visibility. The light bulb shadow test followed the standard of ISO/DIS 13564-1 for traveling and maneuvering tests with four test paths (Test Nos. 1, 3, 4, and 6). Digital human and forklift truck models were developed for the manikin vision assessment test with CATIA V5R13 human modeling solutions. Six participants performed the individual tests. Both employed similar parameters to the light bulb shadow test. The individual test had better visibility with fewer numbers and a greater distribution of the shadowed grids than the other two tests due to eye movement and anthropometric differences. The design factors of load backrest extension, lift chain, hose, dashboard, and steering wheel should be the first factors considered to improve visibility, especially when a forklift truck mainly performs a forward traveling task in an open area.

  2. Online Journals: the Path Towards Visibility and Quality

    Directory of Open Access Journals (Sweden)

    Julie Walker


    Full Text Available Increasing the visibility of a journal is the key to increasing quality. The International Network for the Availability of Scientific Publications works with journal editors in the global South to publish their journals online and to increase the efficiency of the peer review process. Editors are trained in using the Open Journals System software and in online journal management and strategy so they have the tools and knowledge needed to initiate a ‘virtuous cycle' in which visibility leads to an increase in the number and quality of submissions and in turn, increased citations and impact. In order to maximise this increase in quality, it must be supported by strong editorial office processes and management. This article describes some of the issues and strategies faced by the editors INASP works with, placing a particular emphasis on Nepal Journals Online. Key words: INASP; Open Journals System; Journals Online Projects; Nepal Journals Online; journal visibility; peer review DOI: 10.3126/dsaj.v3i0.2786 Dhaulagiri Journal of Sociology and Anthropology Vol.3 2009 175-184

  3. Visible and Infrared Optical Design for the ITER Upper Ports

    Energy Technology Data Exchange (ETDEWEB)

    Lasnier, C; Seppala, L; Morris, K; Groth, M; Fenstermacher, M; Allen, S; Synakowski, E; Ortiz, J


    This document contains the results of an optical design scoping study of visible-light and infrared optics for the ITER upper ports, performed by LLNL under contract for the US ITER Project Office. ITER is an international collaboration to build a large fusion energy tokamak with a goal of demonstrating net fusion power for pulses much longer than the energy confinement time. At the time of this report, six of the ITER upper ports are planned to each to contain a camera system for recording visible and infrared light, as well as other diagnostics. the performance specifications for the temporal and spatial resolution of this system are shown in the Section II, Functional Specifications. They acknowledge a debt to Y. Corre and co-authors of the CEA Cadarache report ''ITER wide-angle viewing and thermographic and visible system''. Several of the concepts used in this design are derived from that CEA report. The infrared spatial resolution for optics of this design is diffraction-limited by the size of the entrance aperture, at lower resolution than listed in the ITER diagnostic specifications. The size of the entrance aperture is a trade-off between spatial resolution, optics size in the port, and the location of relay optics. The signal-to-noise ratio allows operation at the specified time resolutions.

  4. [Visibility and productivity of the biomedical Peruvian journals]. (United States)

    Huamaní, Charles; Pacheco-Romero, José


    Biomedical journals have suffered world wide revolutions due to globalization of information, evolving from the printed version to the electronic one. The status of Peruvian medical journals is not currently known. To determine indexing, production for 2005 to 2007; and visibility of Peruvian biomedical journals for 2008. We identified indexed journals in Medline, SciELO-Peru, Redalyc, LILACS, and others, through informatic search and described the journals production with more indizations, estimating the original research production index. An analysis of electronic visibility of the journals most indexed in SciELO-Peru, Redalyc and SISBIB data bases is done. We identified 29 current journals by 2007. Only Revista de Gastroenterologia del Peru was indexed to Medline. Revista Peruana de Medicina Experimental y Salud Publica was the journal with more production, with 176 publications between 2005 and 2007.Anales de la Facultad de Medicina was the journal with the higher original investigation index, with 0,61. Anales de la Facultad de Medicina had the higher number of electronic visits with 963 965 visits in 2008. There is a great diversity of biomedical journals in Peru but few are indexed and only one is seen in Medline. Original research production is not high but journals electronic visibility is above 600 thousand visitors.

  5. Joint inpainting of depth and reflectance with visibility estimation (United States)

    Bevilacqua, Marco; Aujol, Jean-François; Biasutti, Pierre; Brédif, Mathieu; Bugeau, Aurélie


    This paper presents a novel strategy to generate, from 3-D lidar measures, dense depth and reflectance images coherent with given color images. It also estimates for each pixel of the input images a visibility attribute. 3-D lidar measures carry multiple information, e.g. relative distances to the sensor (from which we can compute depths) and reflectances. When projecting a lidar point cloud onto a reference image plane, we generally obtain sparse images, due to undersampling. Moreover, lidar and image sensor positions typically differ during acquisition; therefore points belonging to objects that are hidden from the image view point might appear in the lidar images. The proposed algorithm estimates the complete depth and reflectance images, while concurrently excluding those hidden points. It consists in solving a joint (depth and reflectance) variational image inpainting problem, with an extra variable to concurrently estimate handling the selection of visible points. As regularizers, two coupled total variation terms are included to match, two by two, the depth, reflectance, and color image gradients. We compare our algorithm with other image-guided depth upsampling methods, and show that, when dealing with real data, it produces better inpainted images, by solving the visibility issue.

  6. On the visibility of airborne volcanic ash and mineral dust (United States)

    Weinzierl, B.; Sauer, D. N.; Minikin, A.; Reitebuch, O.; Dahlkötter, F.; Mayer, B. C.; Emde, C.; Tegen, I.; Gasteiger, J.; Petzold, A.; Veira, A.; Kueppers, U.; Schumann, U.


    After the eruption of the Eyjafjalla volcano (Iceland) in April 2010 which caused the most extensive restrictions of the airspace over Europe since the end of World War II, the aviation safety concept of avoiding "visible ash", i.e. volcanic ash that can be seen by the human eye, was recommended. However so far, no clear definition of "visible ash" and no relation between the visibility of an aerosol layer and related aerosol mass concentrations are available. The goal of our study is to assess whether it is possible from the pilot's perspective in flight to detect the presence of volcanic ash and to distinguish between volcanic ash and other aerosol layers just by sight. In our presentation, we focus the comparison with other aerosols on aerosol types impacting aviation: Besides volcanic ash, dust storms are known to be avoided by aircraft. We use in-situ and lidar data as well photographs taken onboard the DLR research aircraft Falcon during the Saharan Mineral Dust Experiments (SAMUM) in 2006 and 2008 and during the Eyjafjalla volcanic eruption in April/May 2010. We complement this analysis with numerical modelling, using idealized radiative transfer simulations with the 3D Monte Carlo radiative transfer code MYSTIC for a variety of selected viewing geometries. Both aerosol types, Saharan mineral dust and volcanic ash, show an enhanced coarse mode (> 1 μm) aerosol concentration, but volcanic ash aerosol additionally contains a significant number of Aitken mode particles (Volcanic ash is slightly more absorbing than mineral dust, and the spectral behaviour of the refractive index is slightly different. According to our simulations, these differences are not detectable just by human eye. Furthermore, our data show, that it is difficult to define a lower threshold for the visibility of an aerosol layer because the visual detectability depends on many parameters, including the thickness of the aerosol layer, the brightness and color contrast between the airborne

  7. Visibility sweeps for joint-hierarchical importance sampling of direct lighting for stochastic volume rendering

    NARCIS (Netherlands)

    Kroes, T.; Eisemann, M.; Eisemann, E.


    Physically-based light transport in heterogeneous volumetric data is computationally expensive because the rendering integral (particularly visibility) has to be stochastically solved. We present a visibility estimation method in concert with an importance-sampling technique for efficient and

  8. Preliminary results of algorithms to determine horizontal and vertical underwater visibilities of coastal waters

    Digital Repository Service at National Institute of Oceanography (India)

    Suresh, T.; Joshi, Shreya; Talaulikar, M.; Desa, E.J.

    Algorithms developed for underwater horizontal and vertical visibilities are presented. The algorithms have been developed to derive the underwater visibilities based on the contrast theory using the in-situ and Hydrolight derived optical parameters...

  9. Evaluation of visible implant elastomer tags in zebrafish (Danio rerio

    Directory of Open Access Journals (Sweden)

    Claudia Hohn


    The use of the visible implant elastomer (VIE tagging system in zebrafish (Danio rerio was examined. Two tag orientations (horizontal and vertical at the dorsal fin base were tested for tag retention, tag fragmentation and whether VIE tags affected growth and survival of juvenile zebrafish (1–4 month post hatch. Six tag locations (abdomen, anal fin base, caudal peduncle, dorsal fin base, pectoral fin base, isthmus and 5 tag colors (yellow, red, pink, orange, blue were evaluated for ease of VIE tag application and tag visibility in adult zebrafish. Long-term retention (1 year and multiple tagging sites (right and left of dorsal fin and pectoral fin base were examined in adult zebrafish. Lastly, survival of recombination activation gene 1−/− (rag1−/− zebrafish was evaluated after VIE tagging. The best tag location was the dorsal fin base, and the most visible tag color was pink. Growth rate of juvenile zebrafish was not affected by VIE tagging. Horizontal tagging is recommended in early stages of fish growth (1–2 months post hatch. VIE tags were retained for 1 year and tagging did not interfere with long-term growth and survival. There was no mortality associated with VIE tagging in rag1−/− zebrafish. The VIE tagging system is highly suitable for small-sized zebrafish. When familiar with the procedure, 120 adult zebrafish can be tagged in one hour. It does not increase mortality in adult zebrafish or interfere with growth in juvenile or adult zebrafish.

  10. MIMO decorrelation for visible light communication based on angle optimization (United States)

    Zhang, Haiyong; Zhu, Yijun


    Recently, many researchers have used the normal vector tilting to solve the problems about low rate of multiplexing and channel strong correlation in Visible Light Communication Multiple-Input Multiple-Output (VLC-MIMO) system, but they all lack of the theoretical support. In this paper, we establish a channel model about 2×2 VLC-MIMO, then translate the communication problem about vector tilting optimal angle in a certain range into a mathematical problem about seeking the minimum value of function. Finally, we deduced the mathematic expressions about the optimal tilting angles of corresponding LEDs and PDs, and these expressions will provide a theoretical basis for the further study.

  11. Unified origin for baryonic visible matter and antibaryonic dark matter. (United States)

    Davoudiasl, Hooman; Morrissey, David E; Sigurdson, Kris; Tulin, Sean


    We present a novel mechanism for generating both the baryon and dark matter densities of the Universe. A new Dirac fermion X carrying a conserved baryon number charge couples to the standard model quarks as well as a GeV-scale hidden sector. CP-violating decays of X, produced nonthermally in low-temperature reheating, sequester antibaryon number in the hidden sector, thereby leaving a baryon excess in the visible sector. The antibaryonic hidden states are stable dark matter. A spectacular signature of this mechanism is the baryon-destroying inelastic scattering of dark matter that can annihilate baryons at appreciable rates relevant for nucleon decay searches.

  12. The Management of Visibilities in the Digital Age

    DEFF Research Database (Denmark)

    Flyverbom, Mikkel; Leonardi, Paul; Stohl, Cynthia


    What we see, what we show and how we look are fundamental organizational concerns made ever more salient by the affordances, dynamics, and discourses of the digital age. Contemporary organizing practices are awash with material, mediated and managed visibilities: companies erect glass buildings...... with open and networked office spaces to efficiently share information, respond to stakeholder demands by crafting extensive transparency policies, and orchestrate the massive distribution of information online in the name of accountability. At the same time, states and corporations aggregate digital traces...

  13. EUV and Visible Spectroscopy of Promethiumlike Heavy Ions

    CERN Document Server

    Kobayashi, Yusuke; Omote, Kazuki; Komatsu, Akihiro; Sakoda, Junpei; Minoshima, Maki; Kato, Daiji; Li, Jiguang; Sakaue, Hiroyuki A; Murakami, Izumi; Nakamura, Nobuyuki


    We present extreme ultraviolet and visible spectra of promethiumlike tungsten and gold obtained with an electron beam ion trap (EBIT). Although the contributions from a few charge states are involved in the spectra, the charge state of the ion assigned to the observed lines is definitely identified by the time-of-flight analysis of the ions performed at the same time with the spectroscopic measurements. Experimental results are compared with collisional-radiative model calculations as well as previous experimental and theoretical studies.

  14. Gallium Phosphide as a material for visible and infrared optics

    Directory of Open Access Journals (Sweden)

    Václavík J.


    Full Text Available Gallium phosphide is interesting material for optical system working in both visible and MWIR or LWIR spectral ranges. Number of a material available for these applications is limited. They are typically salts, fluorides or sulphides and usually exhibit unfavorable properties like brittleness; softness; solubility in water and small chemical resistance. Although GaP has do not offer best optical parameters excels over most other material in mechanical and chemical resistance. The article describes its most important characteristics and outlines some applications where GaP should prove useful.

  15. Visible light communication: Applications, architecture, standardization and research challenges

    Directory of Open Access Journals (Sweden)

    Latif Ullah Khan


    Full Text Available The Radio Frequency (RF communication suffers from interference and high latency issues. Along with this, RF communication requires a separate setup for transmission and reception of RF waves. Overcoming the above limitations, Visible Light Communication (VLC is a preferred communication technique because of its high bandwidth and immunity to interference from electromagnetic sources. The revolution in the field of solid state lighting leads to the replacement of florescent lamps by Light Emitting Diodes (LEDs which further motivates the usage of VLC. This paper presents a survey of the potential applications, architecture, modulation techniques, standardization and research challenges in VLC.


    Directory of Open Access Journals (Sweden)

    Pavel STANCIU


    Full Text Available Due to the fact that the Internet is now a media zone that tends to monopolize the entire tourist advertising, a careful analysis is required to determine its impact on the marketing activity of the tourist accommodation structures in Bucovina. The major objective of the study aims to highlight the stage development of the touristic accommodation structures in Suceava County through the online visibility filter and, implicitly, their familiarisation with the specific techniques, strategies and marketing methods of the virtual environment.

  17. High-Visibility Photonic Crystal Fiber Interferometer as Multifunctional Sensor

    Directory of Open Access Journals (Sweden)

    Joel Villatoro


    Full Text Available A photonic crystal fiber (PCF interferometer that exhibits record fringe contrast (~40 dB is demonstrated along with its sensing applications. The device operates in reflection mode and consists of a centimeter-long segment of properly selected PCF fusion spliced to single mode optical fibers. Two identical collapsed zones in the PCF combined with its modal properties allow high-visibility interference patterns. The interferometer is suitable for refractometric and liquid level sensing. The measuring refractive index range goes from 1.33 to 1.43 and the maximum resolution is ~1.6 × 10−5.

  18. High-Visibility Photonic Crystal Fiber Interferometer as Multifunctional Sensor (United States)

    Cárdenas-Sevilla, G.A.; Fávero, Fernando C.; Villatoro, Joel


    A photonic crystal fiber (PCF) interferometer that exhibits record fringe contrast (∼40 dB) is demonstrated along with its sensing applications. The device operates in reflection mode and consists of a centimeter-long segment of properly selected PCF fusion spliced to single mode optical fibers. Two identical collapsed zones in the PCF combined with its modal properties allow high-visibility interference patterns. The interferometer is suitable for refractometric and liquid level sensing. The measuring refractive index range goes from 1.33 to 1.43 and the maximum resolution is ∼1.6 × 10−5. PMID:23396192

  19. Visible leadership: going back to the front line. (United States)

    Davies, Nigel


    The report into care at Mid Staffordshire NHS Foundation Trust called for strong leadership in nursing and the government's response acknowledged the importance of senior managers gaining front line experience of the NHS. This article discusses the background to the need for visible leadership and the advantages and disadvantages of different approaches to engaging with the front line. Lessons from other industries are considered and a spectrum of engagement activities relevant to health care suggested. Senior leaders' visits to the front line have brought identified benefits for staff but there is little proof of patient benefits, so more research needs to be commissioned to generate evidence of effectiveness.

  20. UV Visibility of Moderate-Redshift Giant Elliptical Galaxies

    Directory of Open Access Journals (Sweden)

    Myung-Hyun Rhee


    Full Text Available We show quantitatively whether giant elliptical galaxies would be visible at far UV wavelengths if they were placed at moderate redshift of 0.4-0.5. On the basis of simple cosmological tests, we conclude that giant elliptical galaxies can be detectable upto the redshift of 0.4-0.5 in the proposed GALEX (Galaxy Evolution Explorer Deep Imaging Survey. We also show that obtaining UV color index such as m_1550 - V from upcoming GALEX and SDSS (Sloan Digital Sky Survey observations should be feasible.

  1. Performance Analysis of Visible Light Communication Using CMOS Sensors

    Directory of Open Access Journals (Sweden)

    Trong-Hop Do


    Full Text Available This paper elucidates the fundamentals of visible light communication systems that use the rolling shutter mechanism of CMOS sensors. All related information involving different subjects, such as photometry, camera operation, photography and image processing, are studied in tandem to explain the system. Then, the system performance is analyzed with respect to signal quality and data rate. To this end, a measure of signal quality, the signal to interference plus noise ratio (SINR, is formulated. Finally, a simulation is conducted to verify the analysis.

  2. Calibration of the Swift-UVOT ultraviolet and visible grisms


    Kuin, N. P. M.; Landsman, W.; Breeveld, A. A.; Page, M. J.; Lamoureux, H.; James, C.; Mehdipour, M.; Still, M.; Yershov, V.; Brown, P.J.; Carter, M; Mason, K. O.; Kennedy, T.; Marshall, F.; Roming, P. W. A.


    We present the calibration of the Swift Ultraviolet and Optical Telescope (UVOT ) grisms, of which there are two, providing low-resolution field spectroscopy in the ultraviolet and optical bands, respectively. The UV grism covers the range λ1700–5000 Å with a spectral resolution (λ/Δλ) of 75 at λ2600 Å for source magnitudes of u=10–16 mag, while the visible grism covers the range λ2850–6600 Å with a spectral resolution of 100 at λ4000 Å for source magnitudes of b=12–17 mag. This calibration e...

  3. The Swift-UVOT ultraviolet and visible grism calibration


    Kuin, N. P. M.; Landsman, W.; Breeveld, A. A.; Page, M. J.; James, C.; Lamoureux, H.; Mehdipour, M.; Still, M.; Yershov, V.; Brown, P.J.; Carter, M; Mason, K. O.; Kennedy, T.; Marshall, F.; Roming, P. W. A.


    We present the calibration of the Swift UVOT grisms, of which there are two, providing low-resolution field spectroscopy in the ultraviolet and optical bands respectively. The UV grism covers the range 1700-5000 Angstrom with a spectral resolution of 75 at 2600 Angstrom for source magnitudes of u=10-16 mag, while the visible grism covers the range 2850-6600 Angstrom with a spectral resolution of 100 at 4000 Angstrom for source magnitudes of b=12-17 mag. This calibration extends over all detec...

  4. Efficient absorption of visible radiation by gap plasmon resonators. (United States)

    Nielsen, Michael G; Pors, Anders; Albrektsen, Ole; Bozhevolnyi, Sergey I


    We demonstrate experimentally a periodic array of differently-sized and circularly-shaped gap plasmon resonators (GPRs) with the average absorption ~94% for unpolarized light in the entire visible wavelength range (400-750 nm). Finite-element simulations verify that the polarization insensitive broadband absorption originates from localized gap surface plasmons whose resonant excitations only weakly depend on the angle of incidence. Arrays of GPRs also exhibit enhanced local field intensities (~115) as revealed by scanning two-photon photoluminescence microscopy, that are spectrally correlated with the minima in corresponding linear reflection spectra.

  5. Ultraviolet Extinction and Visible Transparency by Ivy Nanoparticles

    Directory of Open Access Journals (Sweden)

    Li Quanshui


    Full Text Available Abstract Though much research has been conducted for nanoparticles, naturally occurring nanoparticles have not yet been well explored for their diverse properties and potential applications. This paper reports the optical absorption and scattering properties of nanoparticles secreted by English ivy. Both experimental and theoretical studies have been conducted. Strong ultraviolet extinction and excellent visible transparency are observed, compared to the inorganic TiO2 and ZnO nanoparticles at similar concentrations. The contributions of absorption and scattering to the total extinction are quantified by simulation of the Mie scattering theory.

  6. Performance comparison of binary modulation schemes for visible light communication

    KAUST Repository

    Park, Kihong


    In this paper, we investigate the power spectral density of several binary modulation schemes including variable on-off keying, variable pulse position modulation, and pulse dual slope modulation which were previously proposed for visible light communication with dimming control. We also propose a novel slope-based modulation called differential chip slope modulation (DCSM) and develop a chip-based hard-decision receiver to demodulate the resulting signal, detect the chip sequence, and decode the input bit sequence. We show that the DCSM scheme can exploit spectrum density more efficiently than the reference schemes while providing an error rate performance comparable to them. © 2015 IEEE.

  7. ‘All of a Sudden, There Are Muslims’: Visibilities and Islamophobic Violence in Canada

    Directory of Open Access Journals (Sweden)

    Barbara Perry


    Full Text Available This paper traces the meanings and impacts of the increased and transformed visibility of Muslim communities in Canada, as evidenced through their experiences of surveillance and violence. It explores the contours of this visibility as well as the consequences. Relationships between Muslims and non-Muslims are shaped in and through hostility, harassment and violence which is directed toward increasingly visible Muslim communities. Guiding the analysis of the connections between visibility and hate crime is a frame that draws upon Brighenti’s ideal types of visibility: media-type, control-type and social-type.

  8. Multiplex visibility graphs to investigate recurrent neural network dynamics (United States)

    Bianchi, Filippo Maria; Livi, Lorenzo; Alippi, Cesare; Jenssen, Robert


    A recurrent neural network (RNN) is a universal approximator of dynamical systems, whose performance often depends on sensitive hyperparameters. Tuning them properly may be difficult and, typically, based on a trial-and-error approach. In this work, we adopt a graph-based framework to interpret and characterize internal dynamics of a class of RNNs called echo state networks (ESNs). We design principled unsupervised methods to derive hyperparameters configurations yielding maximal ESN performance, expressed in terms of prediction error and memory capacity. In particular, we propose to model time series generated by each neuron activations with a horizontal visibility graph, whose topological properties have been shown to be related to the underlying system dynamics. Successively, horizontal visibility graphs associated with all neurons become layers of a larger structure called a multiplex. We show that topological properties of such a multiplex reflect important features of ESN dynamics that can be used to guide the tuning of its hyperparamers. Results obtained on several benchmarks and a real-world dataset of telephone call data records show the effectiveness of the proposed methods.

  9. Generation of powerful tungsten reductants by visible light excitation. (United States)

    Sattler, Wesley; Ener, Maraia E; Blakemore, James D; Rachford, Aaron A; LaBeaume, Paul J; Thackeray, James W; Cameron, James F; Winkler, Jay R; Gray, Harry B


    The homoleptic arylisocyanide tungsten complexes, W(CNXy)6 and W(CNIph)6 (Xy = 2,6-dimethylphenyl, Iph = 2,6-diisopropylphenyl), display intense metal to ligand charge transfer (MLCT) absorptions in the visible region (400-550 nm). MLCT emission (λ(max) ≈ 580 nm) in tetrahydrofuran (THF) solution at rt is observed for W(CNXy)6 and W(CNIph)6 with lifetimes of 17 and 73 ns, respectively. Diffusion-controlled energy transfer from electronically excited W(CNIph)6 (*W) to the lowest energy triplet excited state of anthracene (anth) is the dominant quenching pathway in THF solution. Introduction of tetrabutylammonium hexafluorophosphate, [Bu(n)4N][PF6], to the THF solution promotes formation of electron transfer (ET) quenching products, [W(CNIph)6](+) and [anth](•-). ET from *W to benzophenone and cobalticenium also is observed in [Bu(n)4N][PF6]/THF solutions. The estimated reduction potential for the [W(CNIph)6](+)/*W couple is -2.8 V vs Cp2Fe(+/0), establishing W(CNIph)6 as one of the most powerful photoreductants that has been generated with visible light.

  10. Invisibility Cloaking Based on Geometrical Optics for Visible Light (United States)

    Ichikawa, H.; Oura, M.; Taoda, T.


    Optical cloaking has been one of unattainable dreams and just a subject in fiction until recently. Several different approaches to cloaking have been proposed and demonstrated: stealth technology, active camouflage and transformation optics. The last one would be the most formal approach modifying electromagnetic field around an object to be cloaked with metamaterials. While cloaking based on transformation optics, though valid only at single frequency, is experimentally demonstrated in microwave region, its operation in visible spectrum is still distant from realisation mainly owing to difficulty in fabricating metamaterial structure whose elements are much smaller than wavelength of light. Here we show that achromatic optical cloaking in visible spectrum is possible with the mere principle based on geometrical optics. In combining a pair of polarising beam splitters and right-angled prisms, rays of light to be obstructed by an object can make a detour to an observer, while unobstructed rays go straight through two polarising beam splitters. What is observed eventually through the device is simply background image as if nothing exists in between.

  11. Seeking children's perspectives in the management of visible enamel defects. (United States)

    Rodd, H D; Abdul-Karim, A; Yesudian, G; O'Mahony, J; Marshman, Z


    To undertake a child-centred evaluation of treatment provision for visible enamel defects. Postal questionnaires, developed with children, were sent to 88 patients, aged 7-16 years, with visible enamel defects of permanent incisors and who had received microabrasion, with/without additional composite restoration at Sheffield Dental Hospital, UK. The questionnaires sought children's perceptions about their teeth before and after the intervention, as well as their evaluation of how they had been treated. Anonymised responses were graded using a 10 cm visual analogue scale (VAS) where a score of 10 indicated the most negative response, and zero the most positive response. Sixty three questionnaires were returned (72% response). Prior to treatment, children reported high levels of worry (VAS=6.8), embarrassment (VAS=6.9) and a perception that their teeth looked yellow and discoloured (VAS=7.3). Following treatment, children thought their teeth looked much better (VAS=1.6), felt happier (VAS=2.2) and more confident (VAS=1.6). They also felt very positive about their clinical experiences, rating the staff as extremely friendly and kind (VAS=0.4) and reporting that procedures were clearly explained (VAS=0.6). Simple non-invasive dental treatment can have a positive effect on appearance-related satisfaction. The use of child-centred approaches offers an invaluable insight into patient perspectives. © 2010 The Authors. International Journal of Paediatric Dentistry © 2010 BSPD, IAPD and Blackwell Publishing Ltd.

  12. Academic visibility for urban planning and the webometric future

    Directory of Open Access Journals (Sweden)

    Sanchez Thomas W.


    Full Text Available The author focuses on the analysis problems of the main metrics of scientific productivity for the faculty in the USA universities specializing in the investigations and teaching in the field of urban planning. The increasing role of the Internet is highlighted in the process of communicating the ideas of planning scientists to the professionals and public, extending the reach of academic communications and possibilities of estimating the quality of the investigations and impact. Using case study the methods of applying webometrics for citation analysis in the Internet are investigated. The analysis focused on the main criteria: productivity, visibility, reputation, and impact. The article proposes an expanded approach for estimating general scientific popularity and impact of academics in the Internet, which includes publication analysis in frames of “gray literature”, teaching and outreach activity, which may also be a significant part of the scientific activity. The author stated the importance of academic visibility estimation both for promotion, improving competitiveness of a faculty member on the labor market in the sphere of educational services, and for urban planning schools’ development in general, raising their reputation, prestige and impact, getting the opportunities for financed researches, consolidating the positions on the global educational and science market.

  13. Spontaneous uterine rupture with receding of the visible fetal head. (United States)

    Esen, U I


    A case study of a 32 year old multiparous (para 6) female is presented. Spontaneous labor occurred at 39 weeks gestation. Upon admission her vital signs were normal, and contractions were 3 minutes apart. The fetal heartbeat was normal and the estimated weight was 3.1 kg. The patient's cervix was 80% effaced. After 3 hours of labor, the fetal head was visible at the vulva. Instructions were given to push with uterine contractions. However, the head retracted and was no longer visible. Examination indicated slight vaginal bleeding, increasing pulse rate, and decreasing blood pressure. No fetal heart rate could be detected. Surgery was performed, and 2.5 liters of hemoperitoneum was collected. The uterus had ruptured anteriorly from the fundus to the lower segment and laterally toward the left broad ligament. The male fetus was dead; its weight was 3.25 kg. A hysterectomy was performed. The patient received a blood transfusion of 3 units. 10 days later, the patient was in satisfactory condition and was discharged. The cause of spontaneous uterine rupture in this case study was attributed to grandmultiparity.

  14. All-fiber femtosecond Cherenkov laser at visible wavelengths

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Møller, Uffe Visbech


    -matching condition [1]. The resonant ultrafast wave conversion via the fiber-optic CR mechanism is instrumental for applications in biophotonics such as bio-imaging and microscopy [2]. In this work, we demonstrate a highly-stable all-fiber, fully monolithic CR system based on an Yb-fiber femtosecond laser, producing...... electrically tunable femtosecond CR output in the visible (VIS) spectral range of 580-630 nm, with the 3 dB spectral bandwidth not exceeding 36 nm, with average power in the milliwatt range. Relative intensity noise (RIN) of this laser, affecting the sensitivity of bio-imaging and microscopy systems, is found...... to be as low as -103 dBc/Hz. This is 2 orders of magnitudes lower noise as compared to spectrally-sliced supercontinuum, which is the current standard of ultrafast fiber-optic generation at visible wavelength. The layout of the laser system is shown in Fig. 1(a). The system consists of two parts: an all...

  15. Psychosocial interventions for adults with visible differences: a systematic review

    Directory of Open Access Journals (Sweden)

    Alyson Norman


    Full Text Available Background. Some individuals with visible differences have been found to experience psychosocial adjustment problems that can lead to social anxiety and isolation. Various models of psychosocial intervention have been used to reduce social anxiety and appearance related distress in this population. The objective of this review was to update a previous systematic review assessing the efficacy of psychosocial intervention programs for adults with visible differences. The original review (Bessell & Moss, 2007 identified 12 papers for inclusion.Methods. A search protocol identified studies from 13 electronic journal databases. Methods: Studies were selected in accordance with pre-set inclusion criteria and relevant data were extracted.Results. This update identified an additional four papers that met the inclusion criteria. Two papers provided very limited evidence for the efficacy of a combined cognitive-behavioural and social skills training approach. None of the papers provided sufficient evidence for the optimal duration, intensity or setting of psychosocial interventions for this population.Discussion. The review concluded that a greater number of Randomised Controlled Trials and experimental studies were required to increase the methodological validity of intervention studies.

  16. Plasmonic metamaterials at visible and ultraviolet frequencies (Conference Presentation) (United States)

    Lezec, Henri J.


    Artificial metamaterials - metallo-dielectric composites tailored on deep-subwavelength scale - enable implementation of electromagnetic responses not found in nature, leading to potentially useful applications as well as yielding new insights into the fundamental nature of light. Here we show how we have leveraged ultrasmooth planar nanoplasmonic waveguides deposited by ion-beam-assisted sputter deposition to implement easy-to-fabricate bulk metamaterials operating at visible and ultra-violet wavelengths and having refractive indices ranging from highly anisotropic and positive [1] to quasi-isotropic and negative [2]. Exploiting these structures to tailor the flow of light in exotic ways, we realize devices ranging from high-contrast, near-field nanoparticle optical sensors working in the visible, to the first implementation of a Veselago flat lens [3] functioning in the near ultraviolet. Substituting Al for Ag as the constituent plasmonic metal of choice, we investigate the extension of bulk metamaterial operation into the mid-ultraviolet, for lithographic applications beyond the diffraction limit. [1] T. Xu and H.J. Lezec, Nat. Comm. 5, 4141 (2014). [2] T. Xu, A. Agrawal, M. Abashin, K.J. Chau, and H.J. Lezec, Nature 497, 470 (2013). [3] V.G. Veselago, Sov. Phys. Usp. 10, 509 (1968).

  17. The visibility of non-communicable diseases in Northern Uganda. (United States)

    Whyte, Susan Reynolds; Park, Sung-Joon; Odong, George; Ojara, Moris; Lamwaka, Alice


    WHO and Uganda's Ministry of Health emphasize the need to address the growing burden of non-communicable diseases (NCDs). Treatment for these conditions is urgent in northern Uganda where war has negatively affected both health and the public health care system. We aimed to explore the recognized presence of selected chronic conditions in the out-patient population and to relate this 'visibility' to the ability of health units to diagnose and treat them. At six health facilities we reviewed patient registers for one month to determine the frequency of hypertension, diabetes, depression, and post traumatic stress disorder (PTSD). We checked the availability of diagnostic instruments and medicines, and interviewed health workers. The four conditions were rarely diagnosed in the outpatient population. Hypertension was the most common, but still constituted under 1% of diagnoses. Patterns of diagnosis were uneven, with higher frequency of particular diagnoses at some health facilities. Diagnostic equipment was not sufficient and screening was irregular. Medicine was mostly available although stockouts of some relevant drugs were reported. The four conditions are relatively invisible in the outpatient population. Greater visibility would be facilitated by regular clinic days for hypertension and diabetes, availability and regular use of diagnostic instruments, and a more reliable supply of the relevant medicines.

  18. A bisazobenzene crosslinker that isomerizes with visible light

    Directory of Open Access Journals (Sweden)

    Subhas Samanta


    Full Text Available Background: Large conformational and functional changes of azobenzene-modified biomolecules require longer azobenzene derivatives that undergo large end-to-end distance changes upon photoisomerization. In addition, isomerization that occurs with visible rather than UV irradiation is preferred for biological applications.Results: We report the synthesis and characterization of a new crosslinker in which a central piperazine unit links two azobenzene chromophores. Molecular modeling indicates that this crosslinker can undergo a large change in end-to-end distance upon trans,trans to cis,cis isomerization. Photochemical characterization indicates that it does isomerize with visible light (violet to blue wavelengths. However, the thermal relaxation rate of this crosslinker is rather high (τ½ ~ 1 s in aqueous buffer at neutral pH so that it is difficult to produce large fractions of the cis,cis-species without very bright light sources.Conclusion: While cis-lifetimes may be longer when the crosslinker is attached to a biomolecule, it appears the para-piperazine unit may be best suited for applications where rapid thermal relaxation is required.

  19. Airborne Infrared and Visible Image Fusion Combined with Region Segmentation

    Directory of Open Access Journals (Sweden)

    Yujia Zuo


    Full Text Available This paper proposes an infrared (IR and visible image fusion method introducing region segmentation into the dual-tree complex wavelet transform (DTCWT region. This method should effectively improve both the target indication and scene spectrum features of fusion images, and the target identification and tracking reliability of fusion system, on an airborne photoelectric platform. The method involves segmenting the region in an IR image by significance, and identifying the target region and the background region; then, fusing the low-frequency components in the DTCWT region according to the region segmentation result. For high-frequency components, the region weights need to be assigned by the information richness of region details to conduct fusion based on both weights and adaptive phases, and then introducing a shrinkage function to suppress noise; Finally, the fused low-frequency and high-frequency components are reconstructed to obtain the fusion image. The experimental results show that the proposed method can fully extract complementary information from the source images to obtain a fusion image with good target indication and rich information on scene details. They also give a fusion result superior to existing popular fusion methods, based on eithers subjective or objective evaluation. With good stability and high fusion accuracy, this method can meet the fusion requirements of IR-visible image fusion systems.

  20. Airborne Infrared and Visible Image Fusion Combined with Region Segmentation (United States)

    Zuo, Yujia; Liu, Jinghong; Bai, Guanbing; Wang, Xuan; Sun, Mingchao


    This paper proposes an infrared (IR) and visible image fusion method introducing region segmentation into the dual-tree complex wavelet transform (DTCWT) region. This method should effectively improve both the target indication and scene spectrum features of fusion images, and the target identification and tracking reliability of fusion system, on an airborne photoelectric platform. The method involves segmenting the region in an IR image by significance, and identifying the target region and the background region; then, fusing the low-frequency components in the DTCWT region according to the region segmentation result. For high-frequency components, the region weights need to be assigned by the information richness of region details to conduct fusion based on both weights and adaptive phases, and then introducing a shrinkage function to suppress noise; Finally, the fused low-frequency and high-frequency components are reconstructed to obtain the fusion image. The experimental results show that the proposed method can fully extract complementary information from the source images to obtain a fusion image with good target indication and rich information on scene details. They also give a fusion result superior to existing popular fusion methods, based on eithers subjective or objective evaluation. With good stability and high fusion accuracy, this method can meet the fusion requirements of IR-visible image fusion systems. PMID:28505137

  1. Psychological and social correlates of HIV status disclosure: the significance of stigma visibility. (United States)

    Stutterheim, Sarah E; Bos, Arjan E R; Pryor, John B; Brands, Ronald; Liebregts, Maartje; Schaalma, Herman P


    HIV-related stigma, psychological distress, self-esteem, and social support were investigated in a sample comprising people who have concealed their HIV status to all but a selected few (limited disclosers), people who could conceal but chose to be open (full disclosers), and people who had visible symptoms that made concealing difficult (visibly stigmatized). The visibly stigmatized and full disclosers reported significantly more stigma experiences than limited disclosers, but only the visibly stigmatized reported more psychological distress, lower self-esteem, and less social support than limited disclosers. This suggests that having a visible stigma is more detrimental than having a concealable stigma. Differences in psychological distress and self-esteem between the visibly stigmatized and full disclosers were mediated by social support while differences between the visibly stigmatized and limited disclosers were mediated by both social support and stigma. These findings suggest that social support buffers psychological distress in people with HIV.

  2. Visible-Wavelength Integrated Spectroscopy of Binary Asteroids (United States)

    Reiss, A. E.; Marchis, F.; Emery, J. P.


    Binary asteroid systems consist of two small planetary bodies orbiting a common center of mass. To date, approximately 65 systems have been imaged using adaptive optics, Hubble Space Telescope observations, and various radar imaging methods. An additional 100 binaries are suspected to exist based on light curve analysis and new discoveries are being announced every month. One important task involved in the study of these systems is the classification of their surface mineralogy. The compositional characterization of asteroid surfaces requires observations across a wide wavelength range. A number of rigorous classification methods have been used to group asteroids into classes based on their observed characteristics. Most recently, a feature-based taxonomy was developed by Bus and Binzel [Bus S. J. and Binzel R. P. (2002) Icarus 158, 146-177]. Bus and Binzel decomposed the visible-wavelength (0.44 - 0.92 μm) spectra of asteroids into three major groups—complexes C-, S-, and X-. Each complex was then further refined into 26 sub-classes associated with distinct mineralogical surface features. Using the Shane 3-meter telescope at Lick Observatory, we observed twelve binary asteroid systems with the KAST double spectrograph. The primary observations were conducted on three nights between May and July of 2009 as a part of an observation program to complete the Virtual Observatory Binary Asteroids Database (VOBAD). The spectrograph at the Shane telescope provides wavelength coverage between 0.3 and 1.0 μm using both blue (0.3-0.57 μm) and red (0.53-1.0 μm) channels, with each spectrograph optimized for its wavelength range. Using this instrument, we obtained a comprehensive measurement of our targets' visible spectra, exceeding the wavelength range over which Bus and Binzel taxonomy is based. We obtained visible-wavelength (0.3 - 1.0 μm) spectra for twelve binary asteroid systems, including six objects not previously classified using Bus and Binzel taxonomic

  3. Visibility retrieval in Michelson wide-field stellar interferometry (United States)

    Montilla, I.; Sellos, J.; Pereira, S. F.; Braat, J. J. M.


    Wide-field interferometry has become a subject of increasing interest in recent years. New methods have been suggested in order to avoid the drawbacks of the standard wide-field method (homothetic mapping), which is not applicable when the aperture is highly diluted; for this reason, imaging with non-homothetic arrays is being extensively studied (E. Pedretti, et al., Astron. Astrophys. Suppl. Ser. 147 285 (2000); S. Gillet, et al., Astron. Astrophys. 400 393 (2003)). The field of view of a pupil-plane interferometer or a densified array consists of only a few resolution elements; in order to improve these systems, we have developed a new method consisting of a Michelson pupil-plane combination scheme where a wide field of view can be achieved in one shot. This technique, called the ‘staircase mirror’ approach, has been described in a previous paper (I. Montilla, S.F. Pereira and J.J.M. Braat, Appl. Optics 44 328 (2005)) and uses a stair-shaped mirror in the intermediate image plane of each telescope in the array, allowing for simultaneous correction of the differential delay for both the on- and off-axis image positions. Experimental results have been obtained showing the simultaneous recovery of the fringes of off-axis stars with an appreciable angular separation, and with a contrast similar to that of the on-axis reference star. With this example we demonstrate an increase of the field of view by a factor of 5, with no need for extra observation time. In this article, we present a further analysis of the method. We investigate how to retrieve the visibility when a star is focused on the edge of a step of the stair-shaped mirror. Even though the optical pathlength difference correction is discontinuous, we show both numerically and analytically that the visibility can be completely recovered, so that no information is lost. Our experimental results demonstrate that the visibility can be retrieved to within a 1% error.

  4. [Visible-NIR spectral feature of citrus greening disease]. (United States)

    Li, Xiu-hua; Li, Min-zan; Won Suk, Lee; Reza, Ehsani; Ashish, Ratn Mishra


    Citrus greening (Huanglongbing, or HLB) is a devastating disease caused by Candidatus liberibacter which uses psyllids as vectors. It has no cure till now, and poses a huge threat to citrus industry around the world. In order to diagnose, assess and further control this disease, it is of great importance to first find a quick and effective way to detect it. Spectroscopy method, which was widely considered as a fast and nondestructive way, was adopted here to conduct a preliminary exploration of disease characteristics. In order to explore the spectral differences between the healthy and HLB infected leaves and canopies, this study measured the visible-NIR spectral reflectance of their leaves and canopies under lab and field conditions, respectively. The original spectral data were firstly preprocessed with smoothing (or moving average) and cluster average procedures, and then the first derivatives were also calculated to determine the red edge position (REP). In order to solve the multi-peak phenomenon problem, two interpolation methods (three-point Lagrangian interpolation and four-point linear extrapolation) were adopted to calculate the REP for each sample. The results showed that there were, obvious differences at the visible & NIR spectral reflectance between the healthy and HLB infected classes. Comparing with the healthy reflectance, the HLB reflectance was higher at the visible bands because of the yellowish symptoms on the infected leaves, and lower at NIR bands because the disease blocked water transportation to leaves. But the feature at NIR bands was easily affected by environmental factors such as light, background, etc. The REP was also a potential indicator to distinguish those two classes. The average REP was slowly moving toward red bands while the infection level was getting higher. The gap of the average REPs between the healthy and HLB classes reached to a maximum of 20 nm. Even in the dataset with relatively lower variation, the classification

  5. Navajo Generating Station and Air Visibility Regulations: Alternatives and Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Hurlbut, D. J.; Haase, S.; Brinkman, G.; Funk, K.; Gelman, R.; Lantz, E.; Larney, C.; Peterson, D.; Worley, C.; Liebsch, E.


    Pursuant to the Clean Air Act, the U.S. Environmental Protection Agency (EPA) announced in 2009 its intent to issue rules for controlling emissions from Navajo Generating Station that could affect visibility at the Grand Canyon and at several other national parks and wilderness areas. The final rule will conform to what EPA determines is the best available retrofit technology (BART) for the control of haze-causing air pollutants, especially nitrogen oxides. While EPA is ultimately responsible for setting Navajo Generating Station's BART standards in its final rule, it will be the U.S. Department of the Interior's responsibility to manage compliance and the related impacts. This study aims to assist both Interior and EPA by providing an objective assessment of issues relating to the power sector.

  6. Social network in patient safety: Social media visibility

    Directory of Open Access Journals (Sweden)

    Azucena Santillán García


    Full Text Available Internet social network (social media is a powerful communication tool, and its use is expanding significantly. This paper seeks to know the current state of visibility in online social networks of active citizen talking about patient safety. This is an observational cross-sectional study whose target population is the websites Facebook, Twitter and Tuenti in Spain. By three consecutive cuts social profiles were found using the searching terms “seguridad+paciente” and “safety+patient”. There were found 5 profiles on Facebook that met the search criteria, 6 on Twitter and none were found on Tuenti. It is concluded that although there is evidence of the rise of social networking, citizen network involved in patient safety appears not to be significantly represented within the social networks examined.

  7. Secure positioning technique based on the encrypted visible light map (United States)

    Lee, Y. U.; Jung, G.


    For overcoming the performance degradation problems of the conventional visible light (VL) positioning system, which are due to the co-channel interference by adjacent light and the irregularity of the VL reception position in the three dimensional (3-D) VL channel, the secure positioning technique based on the two dimensional (2-D) encrypted VL map is proposed, implemented as the prototype for the specific embedded positioning system, and verified by performance tests in this paper. It is shown from the test results that the proposed technique achieves the performance enhancement over 21.7% value better than the conventional one in the real positioning environment, and the well known PN code is the optimal stream encryption key for the good VL positioning.

  8. [Visibility of the vaccine cold chain in Spain]. (United States)

    Tuells, J


    Over the last fifty years, the implementation of the vaccine cold chain in Spain has gone through different stages. Related published articles, from the first polio vaccination campaigns until the mid-eighties, show a rudimentary and proactive organization with limited resources. 1990 brought a stage of awareness, when national and regional healthcare authorities started to pay greater attention to appropriate material resources. Finally, the last twenty years represent a third period that has brought the modernization of resources, adoption of protocols, training of clinical personnel involved in the vaccination program, application of logistics and knowledge dissemination. Various studies and publications that have enhanced the acceptable visibility of the vaccine cold chain have been reviewed. It is after all the backbone of the vaccination programmes and though often consigned to the technicians, the vaccine cold chain requires constant training of the clinical staff that administers vaccines.

  9. Toward visible light response: Overall water splitting using heterogeneous photocatalysts

    KAUST Repository

    Takanabe, Kazuhiro


    Extensive energy conversion of solar energy can only be achieved by large-scale collection of solar flux. The technology that satisfies this requirement must be as simple as possible to reduce capital cost. Overall water splitting by powder-form photocatalysts directly produces a mixture of H 2 and O2 (chemical energy) in a single reactor, which does not require any complicated parabolic mirrors and electronic devices. Because of its simplicity and low capital cost, it has tremendous potential to become the major technology of solar energy conversion. Development of highly efficient photocatalysts is desired. This review addresses why visible light responsive photocatalysts are essential to be developed. The state of the art for the photocatalysts for overall water splitting is briefly described. Moreover, various fundamental aspects for developing efficient photocatalysts, such as particle size of photocatalysts, cocatalysts, and reaction kinetics are discussed. Copyright © 2011 De Gruyter.

  10. Investigation of electron transfer between hexaarylbiimidazole and visible sensitizer (United States)

    Lin, Yi; Liu, Andong; Trifunac, Alexander D.; Krongauz, Vadim V.


    Photoinduced electron transfer between the hexaarylbiimidazole (HABI) and visible sensitizer, 2,5-bis [(2,3,6,7-tetrahydro- 1H,5H-benzo [i,j] quinolizin- l-yl ) methylene] cyclopentanone (JAW), in liquid solution was investigated experimentally. The relative fluorescence quantum yield of the sensitizer molecule was measured as a function of HABI concentration. An exponential dependence on HABI concentration was observed for the sensitizer fluorescence yield, from which the critical distance for the electron transfer interaction was determined to be approximately 12 A. The time-dependent fluorescence quenching was studied with the time-correlated single-photon counting technique. The dynamics of the electron transfer process was determined by comparing the experimental data to existing models of electron transfer in liquids, The inclusion of the relative diffusion between the electron donor and acceptor molecules is necessary to fit all the observations and to obtain accurate transfer parameters.

  11. Nano-fabricated pixelated micropolarizer array for visible imaging polarimetry. (United States)

    Zhang, Zhigang; Dong, Fengliang; Cheng, Teng; Qiu, Kang; Zhang, Qingchuan; Chu, Weiguo; Wu, Xiaoping


    Pixelated micropolarizer array (PMA) is a novel concept for real-time visible imaging polarimetry. A 320 × 240 aluminum PMA fabricated by electron beam lithography is described in this paper. The period, duty ratio, and depth of the grating are 140 nm, 0.5, and 100 nm, respectively. The units are standard square structures and the metal nanowires of the grating are collimating and uniformly thick. The extinction ratio of 75 and the maximum polarization transmittance of 78.8% demonstrate that the PMA is suitable for polarization imaging. When the PMA is applied to real-time polarization imaging, the degree of linear polarization image and the angle of linear polarization image are calculated from a single frame image. The polarized target object is highlighted from the unpolarized background, and the surface contour of the target object can be reflected by the polarization angle.

  12. Visibility-based optimal path and motion planning

    CERN Document Server

    Wang, Paul Keng-Chieh


    This monograph deals with various visibility-based path and motion planning problems motivated by real-world applications such as exploration and mapping planetary surfaces, environmental surveillance using stationary or mobile robots, and imaging of global air/pollutant circulation. The formulation and solution of these problems call for concepts and methods from many areas of applied mathematics including computational geometry, set-covering, non-smooth optimization, combinatorial optimization and optimal control. Emphasis is placed on the formulation of new problems and methods of approach to these problems. Since geometry and visualization play important roles in the understanding of these problems, intuitive interpretations of the basic concepts are presented before detailed mathematical development. The development of a particular topic begins with simple cases illustrated by specific examples, and then progresses forward to more complex cases. The intended readers of this monograph are primarily studen...

  13. Refractive index sensitivity in etched FBG in the visible range (United States)

    Kuhne, Jean F.; Nadas, Rafael B.; Inácio, Patricia L.; Chiamenti, Ismael; Kamicawachi, Ricardo C.; Kalinowski, Hypolito José


    A visible fiber Bragg grating (Vis-FBG) with wavelength peak centered at 673.07 nm was inscribed in a multimode fiber designed for infrared (IR) operation using a femtosecond (fs) laser emitting at 248 nm. The fiber cladding is removed by chemical etching in hydrofluoric acid solution (40%). The sensor refractive index response is determined by dipping the sensor into diluted glycerin solution at different concentrations with refractive index range from 1.3328 to 1.4607. The Vis-FBG performance is compared with an IR etched FBG (EFBG) with similar diameter. The sensitivity found for the Vis-FBG sensor is 15.71nm/RIU with a 6.34 x 10-3 RIU resolution for a refractive index of 1.4607.

  14. Third-order gap plasmon based metasurfaces for visible light

    DEFF Research Database (Denmark)

    Deshpande, Rucha Anil; Pors, Anders; Bozhevolnyi, Sergey I.


    -order GSP resonance and thereby involve relatively large nanobricks, can successfully be used for efficient polarization-controlled steering of visible light. The reflection amplitude and phase maps for a 450 nm period array of 50 nm thick nanobricks placed atop a 40 nm thick silica layer supported...... with different dimensions, to operate as a polarization beam splitter for linearly polarized light. The fabricated polarization beam splitter is characterized using a super-continuum light source at normal light incidence and found to exhibit a polarization contrast ratio of up to 40 dB near the design...... (electric field perpendicular to the plane of diffraction) being significantly better (experimentally > 20 % and theoretically > 40 %) than for the TM polarization. This difference becomes even more pronounced for the light incidence deviating from normal. Finally, we discuss possible improvements...

  15. Characterizing visible and invisible cell wall mutant phenotypes

    Energy Technology Data Exchange (ETDEWEB)

    Carpita, Nicholas C.; McCann, Maureen C.


    About 10% of a plant's genome is devoted to generating the protein machinery to synthesize, remodel, and deconstruct the cell wall. High-throughput genome sequencing technologies have enabled a reasonably complete inventory of wall-related genes that can be assembled into families of common evolutionary origin. Assigning function to each gene family member has been aided immensely by identification of mutants with visible phenotypes or by chemical and spectroscopic analysis of mutants with ‘invisible’ phenotypes of modified cell wall composition and architecture that do not otherwise affect plant growth or development. This review connects the inference of gene function on the basis of deviation from the wild type in genetic functional analyses to insights provided by modern analytical techniques that have brought us ever closer to elucidating the sequence structures of the major polysaccharide components of the plant cell wall.

  16. Think tanks in Denmark - Media Visibility and Network Relations

    DEFF Research Database (Denmark)

    Ørsten, Mark; Nørgaard Kristensen, Nete

    and the social democratic think thank the Economic Council of the Labor Movement (ECLM), and their influence on two of the three arenas: the media arena and the administrative arena. Theoretically, we draw on theories of neo-corporatism (Rommetvedt et al., 2012) and mediatization (Hjarvard, 2013; Strömbäck...... & Esser, 2014), and argue that media visibility and attention have become increasingly important for political actors seeking to influence decision makers (Rich & Weaver, 2000), but that corporatist networks and access to the administrative sphere are also still important arenas of influence (Binderkrantz...... have necessitated that actors seeking to influence political decisions mak-ing, such as interest groups, have had to find new ways of influencing policy making (Rom-metvedt et al., 2012). Studies of special interest groups in Denmark have pointed towards three important arenas of influence...

  17. Spatial dimming scheme for optical OFDM based visible light communication. (United States)

    Yang, Yang; Zeng, Zhimin; Cheng, Julian; Guo, Caili


    A new dimming control scheme termed spatial dimming orthogonal frequency division multiplexing (SD-OFDM) is proposed for multiple-input and multiple output OFDM based visible light communication. The basic idea of SD-OFDM is that the illumination can be represented by the number of glared light emitting diodes (LEDs) in an LED lamp. As the biasing level of LEDs does not adjust to represent the required illumination level, the proposed scheme can significantly mitigate the clipping noise compared to analogue dimming schemes. Furthermore, unlike digital dimming schemes that control illumination levels by setting different duty cycles of pulse width modulation, the proposed scheme is always in the "on-state" for varied illumination levels. Both analytical and simulation results indicate that the proposed scheme is an efficient and feasible dimmable scheme.

  18. Inverse design of LED arrangement for visible light communication systems (United States)

    Zheng, Huanhuan; Chen, Jian; Yu, Changyuan; Gurusamy, Mohan


    In this paper, an optimal LED arrangement for indoor visible light communications (VLC) is proposed and numerically investigated. By using the concept of inverse design, the LED distribution can be formulated as a convex optimization problem and resolved accordingly. We show that sufficient brightness and uniform signal to noise ratio (SNR) can be achieved within the indoor coverage by using the proposed optimal LED arrangement, thus enabling the terminal mobility for indoor VLC. In addition, the analysis of delay spread distribution over the receiving plane shows that the design exhibits enhanced tolerance of inter-symbol interference (ISI). With the consideration of cabling cost for practical implementation, the suboptimal LED arrangement design is also investigated. Numerical results indicate that the suboptimal design can reduce the power consumption of the system with acceptable performance degradation.

  19. Making women visible in disasters: problematising the private domain. (United States)

    Fordham, M H


    Gender awareness and sensitivity in disaster research and management remains uncommon and tends to focus on the developing rather than the developed world. This paper uses a feminist oral geography to present some findings about women's experiences in two floods in Scotland. It is conceptualised around public and private (masculinised and feminised) space, problematising the private domain and presenting it, in the feminist research tradition, as a legitimate object of research. It shows the ordinary and everyday to be more opaque and complex than usually imagined and makes recommendations for their recognition and incorporation into disaster management. While there is a specific focus on the private domain of the home, this is not intended to reinforce gender stereotypes but simply to recognise the reality of many of the women interviewed. It concludes that disaster research generally has yet to advance much beyond the earliest stages of feminist studies which merely sought to make women visible in society.

  20. OCT angiography and visible-light OCT in diabetic retinopathy. (United States)

    Nesper, Peter L; Soetikno, Brian T; Zhang, Hao F; Fawzi, Amani A


    In recent years, advances in optical coherence tomography (OCT) techniques have increased our understanding of diabetic retinopathy, an important microvascular complication of diabetes. OCT angiography is a non-invasive method that visualizes the retinal vasculature by detecting motion contrast from flowing blood. Visible-light OCT shows promise as a novel technique for quantifying retinal hypoxia by measuring the retinal oxygen delivery and metabolic rates. In this article, we discuss recent insights provided by these techniques into the vascular pathophysiology of diabetic retinopathy. The next milestones for these modalities are large multicenter studies to establish consensus on the most reliable and consistent outcome parameters to study diabetic retinopathy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Noise analysis for CCD-based ultraviolet and visible spectrophotometry. (United States)

    Davenport, John J; Hodgkinson, Jane; Saffell, John R; Tatam, Ralph P


    We present the results of a detailed analysis of the noise behavior of two CCD spectrometers in common use, an AvaSpec-3648 CCD UV spectrometer and an Ocean Optics S2000 Vis spectrometer. Light sources used include a deuterium UV/Vis lamp and UV and visible LEDs. Common noise phenomena include source fluctuation noise, photoresponse nonuniformity, dark current noise, fixed pattern noise, and read noise. These were identified and characterized by varying light source, spectrometer settings, or temperature. A number of noise-limiting techniques are proposed, demonstrating a best-case spectroscopic noise equivalent absorbance of 3.5×10(-4)  AU for the AvaSpec-3648 and 5.6×10(-4)  AU for the Ocean Optics S2000 over a 30 s integration period. These techniques can be used on other CCD spectrometers to optimize performance.

  2. Visible Light Communications (VLC) for Ambient Assisted Living

    DEFF Research Database (Denmark)

    Kumar, Ambuj; Mihovska, Albena D.; Kyriazakos, Sofoklis


    With the advent of high efficacy light emitting diode (LED) directional lamps as a key component in focal lighting, new possibilities emerge for re-designing the smart home scenario. A smart home scenario is characterized by enabled intelligent interworking of various wireless and wired...... (WLANs) can take upon part of the indoor traffic, the ever increasing demand for such data, and users, calls for either use of licensed or novel unlicensed wireless communication technologies as part of the smart home enablers. This paper focuses on the potentials of visible light communications (VLC......), jointly with radio and fiber communications, to support very dense low and high data rate connectivity, while enabling deployment of secure-sensitive indoor applications, including indoor tracking and localization. The paper proposes a scenario for integrating VLC into the smart home scenario...

  3. Optimal linear precoding for indoor visible light communication system

    KAUST Repository

    Sifaou, Houssem


    Visible light communication (VLC) is an emerging technique that uses light-emitting diodes (LED) to combine communication and illumination. It is considered as a promising scheme for indoor wireless communication that can be deployed at reduced costs while offering high data rate performance. In this paper, we focus on the design of the downlink of a multi-user VLC system. Inherent to multi-user systems is the interference caused by the broadcast nature of the medium. Linear precoding based schemes are among the most popular solutions that have recently been proposed to mitigate inter-user interference. This paper focuses on the design of the optimal linear precoding scheme that solves the max-min signal-to-interference-plus-noise ratio (SINR) problem. The performance of the proposed precoding scheme is studied under different working conditions and compared with the classical zero-forcing precoding. Simulations have been provided to illustrate the high gain of the proposed scheme.

  4. Precoded generalized space shift keying for indoor visible light communications

    KAUST Repository

    Kadampot, Ishaque Ashar


    We consider a visible light communication system with 2 transmit light emitting diodes (LED) and nr receive photodiodes. An optical generalized space shift keying modulation scheme is considered for the transmission of bits where each LED can be either in ON state or OFF state at a given time. With this set-up, we design in this paper a precoder for this modulation scheme given the channel state information to improve the bit error rate performance of the system. As conventional precoding techniques for radio frequency at the transmitter cannot be applied to the optical intensity channel, we formulate an optimization problem with constraints for this specific channel. An analytical solution for the precoder is derived and the system performance is compared with and without precoder.

  5. A novel visible light responsive nanosystem for cancer treatment. (United States)

    Martínez-Carmona, M; Lozano, D; Baeza, A; Colilla, M; Vallet-Regí, M


    A novel singlet-oxygen sensitive drug delivery nanocarrier able to release its cargo after exposure to visible (Vis) light from a common lamp is presented. This nanodevice is based on mesoporous silica nanoparticles (MSN) decorated with porphyrin-caps grafted via reactive oxygen species (ROS)-cleavable linkages. In the presence of Vis light porphyrin-nanocaps produce singlet oxygen molecules that break the sensitive-linker, which triggers pore uncapping and therefore allows the release of the entrapped cargo (topotecan, TOP). This new system takes advantage of the non-toxicity and greater penetration capacity of Vis radiation and a double antitumor effect due to the drug release and the ROS production. In vitro tests with HOS osteosarcoma cancer cells reveal that TOP is able to be released in a controlled fashion inside the tumor cells. This research work constitutes a proof of concept that opens up promising expectations in the search for new alternatives for the treatment of cancer.

  6. Downlink resource allocation for multichannel TDMA visible light communications

    KAUST Repository

    Abdelhady, Amr Mohamed Abdelaziz


    Optical wireless communications (OWC) in general and resource allocation in OWC networks particularly have gained lots of attention recently. In this work, we consider the resource allocation problem of a visible light communication downlink transmission system based on time division multiple access with the objective of maximizing spectral efficiency (SE). As for the operational conditions, we impose constraints on the average optical intensity, the energy consumption and the quality-of-service. To solve the non-convex problem, we transform the objective function into a difference of concave functions by solving a second order differential inequality. Then, we propose a low-complexity algorithm to solve the resource allocation problem. Finally, we show by simulations the SE performance gains achieved by optimizing the power allocation over equal power allocation in the considered system. Numerical results show the SE gains achieved by using this solution.

  7. Young English language learners making thinking and language visible

    Directory of Open Access Journals (Sweden)

    Angela K Salmon


    Full Text Available This paper aims to provide teachers with a resource to assist them in understanding the inner workings of young English Language Learners (ELLs and how they externalize their thoughts in either their first or second language. This article not only analyzes how teachers can help children acquire a second language without sacrificing their first language and motivation, but also focuses on language processing in bilingual children through providing an understanding of both the interplay between language and cognition and the role of the environment. Results from an action research project implementing Harvard Project Zero’s Visible Thinking ideas serve as evidence to discuss the benefits of creating a culture of thinking in the classroom to promote additive bilingualism in young children.

  8. Indoor localization system utilizing two visible light emitting diodes (United States)

    Mousa, Farag I. K.; Le-Minh, Hoa; Ghassemlooy, Zabih; Dai, Xuewu; Tran, Son T.; Boucouvalas, Anthony C.; Liaw, Shien-Kuei


    Indoor positioning or localization based on visible light communications (VLC) is an emerging technology with wide applications. In conventional localization schemes, the trilateration technique is widely used with at least three separate lighting sources to determine the user's location. An indoor VLC positioning scheme based on the optical power distributions of only two light emitting diodes (LEDs) is reported for different environments. We have used two received signal strength indications to determine the user's position based on the LEDs configuration offering less complexity. We propose comprehensive mathematical models for the VLC localization system considering the noise and its impact on the user's location, and numerically evaluated it over a range of signal-to-noise ratios (SNRs). In addition, it is compared to the results with the exiting trilateration technique. The performance of the proposed system is evaluated with a reported accuracy of 13 dB.

  9. A novel mirror diversity receiver for indoor MIMO visible light

    KAUST Repository

    Park, Ki-Hong


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

  10. Visibility of stars, halos, and rainbows during solar eclipses. (United States)

    Können, Gunther P; Hinz, Claudia


    The visibility of stars, planets, diffraction coronas, halos, and rainbows during the partial and total phases of a solar eclipse is studied. The limiting magnitude during various stages of the partial phase is presented. The sky radiance during totality with respect to noneclipse conditions is revisited and found to be typically 1/4000. The corresponding limiting magnitude is +3.5. At totality, the signal-to-background ratio of diffraction coronas, halos, and rainbows has dropped by a factor of 250. It is found that diffraction coronas around the totally eclipsed Sun may nevertheless occur. Analyses of lunar halo observations during twilight indicate that bright halo displays may also persist during totality. Rainbows during totality seem impossible.

  11. Polarization and visibility of higher-order rainbows. (United States)

    Können, Gunther P


    The degree of polarization of rainbows of order k with k≥3 is bounded in the interval [75%, 78%], where 75% is the limit for k→∞. A polarization filter can improve the signal-to-background ratio of the third and fourth rainbows by a factor of 2, which may lift their visibilities in natural circumstances above the threshold of human visual perception. Under optimal circumstances, the latter may be true for the recently photographed green fingerprint of the fifth rainbow, even without the aid of a polarization filter. The prospects for observing the sixth rainbow are unclear. There exists a possibility that the signal of the natural seventh rainbow (appearing at 64° from the Sun) may be separated from its background if photographed under perfect conditions through a polarization filter.

  12. All solid-state high power visible laser (United States)

    Grossman, William M.


    The overall objective of this Phase 2 effort was to develop and deliver to NASA a high repetition rate laser-diode-pumped solid-state pulsed laser system with output in the green portion of the spectrum. The laser is for use in data communications, and high efficiency, short pulses, and low timing jitter are important features. A short-pulse 1 micron laser oscillator, a new multi-pass amplifier to boost the infrared power, and a frequency doubler to take the amplified infrared pulsed laser light into the green. This produced 1.5 W of light in the visible at a pulse repetition rate of 20 kHz in the laboratory. The pulses have a full-width at half maximum of near 1 ns. The results of this program are being commercialized.

  13. Visible Multiphoton Dissociation of Chromophore-Tagged Peptides (United States)

    Bouakil, Mathilde; Kulesza, Alexander; Daly, Steven; MacAleese, Luke; Antoine, Rodolphe; Dugourd, Philippe


    The visible photodissociation mechanisms of QSY7-tagged peptides of increasing size have been investigated by coupling a mass spectrometer and an optical parametric oscillator laser beam. The experiments herein consist of energy resolved collision- and laser-induced dissociation measurements on the chromophore-tagged peptides. The results show that fragmentation occurs by similar channels in both activation methods, but that the branching ratios are vastly different. Observation of a size-dependent minimum laser pulse energy required to induce fragmentation, and collisional cooling rates in time resolved experiments show that laser-induced dissociation occurs through the absorption of multiple photons by the chromophore and the subsequent heating through vibrational energy redistribution. The differences in branching ratio between collision- and laser-induced dissociation can then be understood by the highly anisotropic energy distribution following absorption of a photon. [Figure not available: see fulltext.

  14. ERIH PLUS – Making the SSH visible, searchable and available

    Energy Technology Data Exchange (ETDEWEB)

    Lavik, G.A.; Sivertsen, G


    The European Reference Index for the Humanities and the Social Sciences (ERIH PLUS) is a non-commercial initiative to increase the visibility of the humanities and the social sciences (SSH) by providing an international infrastructure for a comprehensive bibliographic coverage of the scholarly communication and publishing in these fields. A well-defined, standardized and dynamic register of scholarly journals and series is already up and running. Since a combination of national and international publishing is practised in the SSH, titles in all European languages are covered in ERIH PLUS if they to correspond to six verifiable criteria. The register thereby challenges the commercial indexing services which tend to represent the SSH as “peripheral” to the sciences. (Author)

  15. Discrete Input Signaling for MISO Visible Light Communication Channels

    KAUST Repository

    Arfaoui, Mohamed Amine


    In this paper, we study the achievable secrecy rate of visible light communication (VLC) links for discrete input distributions. We consider single user single eavesdropper multiple-input single-output (MISO) links. In addition, both beamforming and robust beamforming are considered. In the former case, the location of the eavesdropper is assumed to be known, whereas in the latter case, the location of the eavesdropper is unknown. We compare the obtained results with those achieved by some continuous distributions including the truncated generalized normal (TGN) distribution and the uniform distribution. We numerically show that the secrecy rate achieved by the discrete input distribution with a finite support is significantly improved as compared to those achieved by the TGN and the uniform distributions.

  16. Female visibility through Korean literature: Feminist theological critique

    Directory of Open Access Journals (Sweden)

    Eun Ok Jeong


    Full Text Available This article introduces Korean women’s experience as seen through the lense of social and cultural backgrounds, from the premodern through to the postmodern era. Korean literature is used as a source to investigate Korean women’s experiences and perspectives. By means of feminist critique this article explores men-centered influences in Korean literature. It aims to illustrate the importance of the issue of female visibility through Korean literature from a Korean woman’s perspective. Two texts are analyzed and critiqued: the first is the myth of Korean origin. The second is a story of Gasi Gogi (a thorny fish. The article is intended to stimulate debate on gender, voices, and authority from a feminist perspective, in order to transcend the more traditional interpretations.

  17. The visibility of non-communicable diseases in northern Uganda

    DEFF Research Database (Denmark)

    Whyte, Susan Reynolds; Park, Sung-Joon; Odong, George


    Background : WHO and Uganda’s Ministry of Health emphasize the need to address the growing burden of non-communicable diseases (NCDs). Treatment for these conditions is urgent in northern Uganda where war has negatively affected both health and the public health care system. Objectives : We aimed...... under 1% of diagnoses. Patterns of diagnosis were uneven, with higher frequency of particular diagnoses at some health facilities. Diagnostic equipment was not sufficient and screening was irregular. Medicine was mostly available although stockouts of some relevant drugs were reported. Conclusions...... : The four conditions are relatively invisible in the outpatient population. Greater visibility would be facilitated by regular clinic days for hypertension and diabetes, availability and regular use of diagnostic instruments, and a more reliable supply of the relevant medicines....

  18. Visible Color and Photometry of Bright Materials on Vesta (United States)

    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.


    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].


    Energy Technology Data Exchange (ETDEWEB)

    Steven S.C. Chuang


    Visible light-photocatalysis could provide a cost-effective route to recycle CO{sub 2} to useful chemicals or fuels. Development of an effective catalyst for the photocatalytic synthesis requires (i) the knowledge of the surface band gap and its relation to the surface structure, (ii) the reactivity of adsorbates and their reaction pathways, and (iii) the ability to manipulate the actives site for adsorption, surface reaction, and electron transfer. The objective of this research is to study the photo-catalytic activity of TiO{sub 2}-base catalyst. A series of TiO{sub 2}-supported metal catalysts were prepared for determining the activity and selectivity for the synthesis of methane and methanol. 0.5 wt% Cu/SrTiO{sub 3} was found to be the most active and selective catalyst for methanol synthesis. The activity of the catalyst decreased in the order: Ti silsesquioxane > Cu/SrTiO{sub 3} > Pt/TiO{sub 2} > Cu/TiO{sub 2} > TiO{sub 2} > Rh/TiO{sub 2}. To further increase the number of site for the reaction, we propose to prepare monolayer and multiplayer TiOx on high surface area mesoporous oxides. These catalysts will be used for in situ IR study in the Phase II research project to determine the reactivity of adsorbates. Identification of active adsorbates and sites will allow incorporation of acid/basic sites to alter the nature of CO{sub 2} and H{sub 2}O adsorbates and with Pt/Cu sites to direct reaction pathways of surface intermediates, enhancing the overall activity and selectivity for methanol and hydrocarbon synthesis. The overall goal of this research is to provide a greater predictive capability for the design of visible light-photosynthesis catalysts by a deeper understanding of the reaction kinetics and mechanism as well as by better control of the coordination/chemical environment of active sites.

  20. Ice-supersaturated regions and sub visible cirrus

    Energy Technology Data Exchange (ETDEWEB)

    Gierens, K.; Schumann, U.; Spichtinger, P. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Wessling (Germany). Inst. fuer Physik der Atmosphaere; Helten, M.; Smit, H. [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Chemie und Dynamik der Geosphaere 2: Chemie der Belasteten Atmosphaere; Wang, P.H. [Science and Technology Corp., Hampton, VA (United States)


    Humidity and temperature data from the MOZAIC project have been used to produce maps of probability for ice-supersaturation in two 50 hPa thick layers centered around 200 and 250 hPa. The maps are presented in T42 resolution, i.e. with a grid size of about 300 x 300 km{sup 2}. As the MOZAIC data cover only international air routes, the resulting maps cover mainly the northern midlatitudes. The data of ice-supersaturation have then been correlated with data of frequency of occurrence of sub visible cirrus from the SAGE II satellite. The correlation analysis provided strong indications that sub visible cirrus (SVC) is associated to ice-supersaturated regions (ISSRs), although processes are possible that can decouple SVC from ISSRs. A first trial to derive a global picture of ice-supersaturation near the tropopause was performed using cirrus fractional coverage derived from meteorological analyses of ECMWF and to correlate this with the supersaturation data. The correlation was moderate but significant, so that we might expect from the cirrus coverage data larger probabilities of ice-supersaturation over the Indonesian archipelago, over the amazonas basin, and over the northern Pacific between Japan and Canada. A final correlation analysis between the meteorological analysis data and the SVC data demonstrated that the formation of SVC is thermodynamically controlled, in particular in the tropics. In the midlatitude SVC, however, the control by thermodynamics is weaker, probably because freezing of solution droplets is more sensitive to the composition of the available aerosol at the higher midlatitude tropopause temperatures. (orig.)

  1. Broadband Measurement of Aerosol Extinction in the Visible Range (United States)

    He, Quanfu; Bluvshtein, Nir; Segev, Lior; Flores, Michel; Rudich, Yinon; Washenfelder, Rebecca; Brown, Steven


    Atmospheric aerosols influence the Earth's radiative budget directly by scattering and absorbing incoming solar radiation. Aerosol direct forcing remains one of the largest uncertainties in quantifying the role that aerosols play in the Earth's radiative budget. The optical properties of aerosols vary as a function of wavelength, but few measurements reported the wavelength dependence of aerosol extinction cross section and complex refractive indices, particularly in the blue and visible spectral range. There is also currently a large gap in our knowledge of how the optical properties evolve as a function of atmospheric aging in the visible spectrum. In this study, we constructed a new and novel laboratory instrument to measure aerosol extinction as a function of wavelength, using cavity enhanced spectroscopy with a white light source. This broadband cavity enhanced spectroscopy (BBCES) covers the 395-700 nm spectral region using a broadband light source and a grating spectrometer with charge-coupled device detector (CCD). We evaluated this BBCES by measuring extinction cross section for aerosols that are pure scattering, slightly absorbing and strongly absorbing atomized from standard materials. We also retrieved the refractive indices from the measured extinction cross sections. Secondary organic aerosols from biogenic and anthropogenic precursors were "aged" to differential time scales (1 to 10 days) in an Oxidation Flow Reactor (OFR) under the combined influence of OH, O3 and UV light. The new BBCES was used to online measure the extinction cross sections of the SOA. This talk will provide a comprehensive understanding of aerosol optical properties alerting during aging process in the 395 - 700 nm spectrum.

  2. Source-oriented model for air pollutant effects on visibility (United States)

    Eldering, A.; Cass, G. R.


    A source-oriented model for air pollutant effects on visibility has been developed that can compute light scattering, light extinction, and estimated visual range directly from data on gas phase and primary particle phase air pollutant emissions from sources. The importance of such a model is that it can be used to compute the effect of emission control proposals on visibility-related parameters in advance of the adoption of such control programs. The model has been assembled by embedding several aerosol process modules within the photochemical trajectory model previously developed for aerosol nitrate concentration predictions by Russell et al. [1983] and Russell and Cass [1986]. These modules describe the size distribution and chemical composition of primary particle emissions, the speciation of organic vapor emissions, atmospheric chemical reactions, transport of condensible material between the gas and the particle phases, fog chemistry, dry deposition, and atmospheric light scattering and light absorption. Model predictions have been compared to observed values using 48-hour trajectories arriving at Claremont, California, at each hour of August 28, 1987, during the Southern California Air Quality Study. The predicted fine particle concentration averages 62 μg m-3 compared to an observed value of 61 μg m-3, while predicted PM10 concentrations average 102 μg m-3 compared to an observed average of 97 μg m-3. The size distribution and chemical composition predictions for elemental carbon, sulfate, and sodium ion agree with observations to within plus or minus a few micrograms per cubic meter, while ammonium and nitrate concentrations are underpredicted by the base case model by 3 to 7 μg m-3 on average. Light-scattering coefficient values are calculated from the predicted aerosol size distribution and refractive index, and the model predictions agree with measured values on average to within 19%. The advantages and limitations of the modeling procedure are

  3. Visibility, accessibility and quality of Italian public health institutional websites

    Directory of Open Access Journals (Sweden)

    Simone Chiadò Piat


    Full Text Available

    Background: Since the large volume of health information available on the Web has the potential to improve health, Public Health institutions must represent a strong Internet presence with accessible and scientific information. The aims of the study were to verify the presence and visibility of Italian Institutions on the Web and to evaluate the accessibility and quality of the information provided.

    Methods: In a focus group setting, 21 keywords were generated, and launched in search-engines Google and MSN. Researchers noted the first 30 results found and determined the position of institutional websites. The accessibility of 303 Public Health websites was assessed in relation to the logo presence and web validation of XHTML, CSS and WAI indicators. Regarding the quality of information, the presence of the HONcode logo in the websites’ homepage was checked.

    Results: A high percentage of the keywords selected did not lead to any institutional website in the first three pages of Google (19.0% and MSN (42.8%. Few institutional websites presented the logo indicator and a full web validation. Considering the XHTML indicator, only for 34.0% of the websites there was concordance between the logo presence/absence and results of direct validation, 50.2% for CSS. The quality level seemed to be extremely low.

    Conclusions:In order to achieve a larger visibility and guarantee accessibility, Public Health websites have to be correctly designed, edited and maintained. Common and strict European laws about health information on the Web have to be arranged, deeply monitored and carefully adjourned in order to guarantee and support the positive role of institutional websites.

  4. Scaling properties of observed and simulated satellite visible radiances (United States)

    Barker, Howard W.; Qu, Zhipeng; Bélair, Stéphane; Leroyer, Sylvie; Milbrandt, Jason A.; Vaillancourt, Paul A.


    Structure functions Sq, which are related to power spectra and used to study turbulence, were computed for GOES-13 visible radiances measured on 16 May 2015 over French Guiana and adjacent Atlantic Ocean. The nested Global Environmental Multiscale (GEM) numerical weather prediction (NWP) model was run for the same time and area. Cloud data generated by GEM over (300 km)2 domains, with one-way nesting ending at horizontal grid-spacing of 0.25 km, were operated on by a 3-D solar radiative transfer model with resulting radiances degraded to GOES-13 resolution ( 1 km) and Sq computed for them, too. For GOES-13 radiances, scaling exponents ζ(2) associated with S2, for separation distances between 5 km and 25 km, were typically >0.6 for deep convective and marine boundary layer clouds and ζ(2) for GEM agreed well with GOES-13 for deep convective clouds. This suggests that the self-organizing properties of deep convection in GEM exhibit realistic geometric features, a potentially important point given the link between cloud structure and precipitation, with the latter being much more difficult to measure and assess than visible radiances. Regarding radiances for GEM's marine boundary layer clouds, their Sq differed markedly from GOES-13's; better resembling fair-weather cumulus. Likewise, GEM's shallow cumuli over land appear to have bypassed the "scattered" fair-weather stage and went straight into more organized convection. Thus, it appears that comparing time series of Sq for geostationary satellite data and corresponding modeled radiances has the potential to benefit assessment of cloud system-resolving models.

  5. Development and evaluation of a new digital photography visiometer system for automated visibility observation (United States)

    Wang, Jingli; Liu, Xulin; Yang, Xihua; Lei, Ming; Ruan, Shunxian; Nie, Kai; Miao, Yupeng; Liu, Jincheng


    Visibility information is fundamental in aviation, navigation, land transportation, air quality and dust storm monitoring, and military activities which often require frequent and accurate real-time observation of visibility. The traditional manual observation, the primary means to obtain visibility information by human eyes, is subjective, inconsistent and costly. Instrumental observation (or traditional optical instrument) has overcome some of these limitations, but it is difficult to obtain correct visibility information in a complicated atmospheric (e.g. rainy and foggy) environment. We developed a new visibility instrument, digital photography visiometer system (DPVS), equipped with advanced digital photographic technology including high-resolution charge-coupled-device camera and computer. The new DPVS imitates the human eye observation and accurately calculates the visibility based on its definition and observational principles. We compared the results of the new DPVS with those from a forward scattering visibility instrument (FD12) and manual visibility observations in various (rainy, non-rainy, foggy) weather conditions. The comparative results show that the new DPVS, FD12, and manual observation have the same trend of change, but the observation from the new DPVS is closer to that from the manual observations in rainy days or complicated weather conditions. Our study demonstrates that the new DVPS is superior to the optical visibility instrument and can be used for automated visibility observations under all weather conditions.

  6. A system for monitoring and improving animal visibility and its implications for zoological parks. (United States)

    Kuhar, C W; Miller, L J; Lehnhardt, J; Christman, J; Mellen, J D; Bettinger, T L


    With the growing trend in zoos to build complex, naturalistic exhibits comes the potential for exhibits to be so densely vegetated or complex that animals are not easily seen by zoo visitors. This can negatively impact the visitor's visiting experience and the zoo's ability to communicate conservation and education messages. Over the past 9 years, Disney's Animal Kingdom has developed a process for monitoring and improving the visibility of animals on display to the public. This animal visibility process utilizes a data collection system whereby systematic observations are collected each week. The percentage of observations where at least one animal was visible is recorded for each species and compared to an 80% visibility criterion. Species that do not reach this criterion for 4 consecutive weeks are discussed at animal management meetings. If the problems associated with animal visibility cannot be easily solved, the animal-care teams partner with the research team to conduct a second process, called the Visibility Issues Process. This process provides additional information for the animal-care team to utilize in developing a plan to improve visibility. Although the processes described here are specific to the infrastructure at Disney's Animal Kingdom, the basic concepts of (1) a formalized visibility data collection process, (2) a visibility criterion to which managers of species are held accountable, and (3) a process for planning to improve animal visibility without negatively impacting animal welfare are fundamental concepts that can be developed at individual institutions and incorporated into that zoo's existing infrastructure.

  7. Visibility of sutures of the orbit and periorbital region using multidetector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Gufler, Hubert; Preis, Markus; Koesling, Sabrina [Dept. of Diagnostic Radiology, Martin-Luther-University Halle-Wittenberg, Halle (Germany)


    Knowledge of cranial suture morphology is crucial in emergency medicine, forensic medicine, and maxillofacial reconstructive surgery. This study assessed the visibility of sutures of the orbit and periorbital region on multidetector computed tomography. Multidetector computed tomography scans of 200 patients (127 males, 73 females; mean age 51.3 years; range, 6-92 years) were evaluated retrospectively. The slice thicknesses varied from 0.5 to 1 mm, and the tube current from 25 to 370 mAs, depending on the CT indication. The visibility of sutures was estimated according to a 4-point scale from 'not visible to well visible' The chi-squared test was used to test the association of the visibility of sutures with the slice thickness, tube current, and age of patients. Statistical significance was assumed at p < 0.05. Overall, best visibility was found for the sutura frontozygomatica (98%), sutura frontonasalis (88.5%), and sutura sphenozygomatica (71.5%), followed by the sutura zygomaticomaxillaris (65.8%), sutura temporozygomatica (41.8%), sutura frontomaxillaris (44.5%), and sutura sphenofrontalis (31%). Poor visibility was found for the sutura frontolacrimalis (16.8%) and sutura frontoethmoidalis (1.3%). The sutura ethmoidomaxillaris, sutura lacrimomaxillaris, and sutura ethmoidolacrimalis were not visible. Although the sutures of the superior, lateral, and inferior orbit are well visible, those of the medial orbit are poorly visible on CT scans.

  8. The System of the Calibration for Visibility Measurement Instrument Under the Atmospheric Aerosol Simulation Environment


    Shu Zhifeng; Yang ShaoChen; Xu Wenjing


    Visibility is one of the most important parameters for meteorological observation and numerical weather prediction (NWP).It is also an important factor in everyday life, mainly for surface and air traffic especially in the Aeronautical Meteorology. The visibility decides the taking off and landing of aircraft. If the airport visibility is lower than requirement for aircraft taking off stipulated by International Civil Aviation Administration, then the aircraft must be parked at the airport. S...

  9. Enhancement of Light via Surface Plasmon Coupling in the Visible (United States)

    Ray, Emily A.

    The incidence of light with momentum components outside the light cone on the surface of a negative permittivity material results in the excitation of a surface plasmon polariton and the enhancement of the incident signal when there is momentum and energy conservation. This process has an impact across many fields including imaging, optical computing, signaling, and photovoltaic devices, among others. I examine the role and tunability of light-surface plasmon interactions in several applications. I demonstrate a tuned metamaterial grating system that allows the signal from evanescent waves to be detected in the far field in the visible regime. I fabricate a metamaterial that is tuned to support surface plasmons that couple to visible light across a wide range of wavelengths. I characterize the plasmonic response through a simple technique wherein a the reflection from a subwavelength grating on a metamaterial indicates surface plasmon coupling when its intensity dips. With this I demonstrate that the reflection trends match well with simulation, indicating that coupling of light to surface plasmons occurs at the expected crossing points. The strength of coupling (denoted by the drop in reflection) however, is less than expected. Transmission measurements reveal a depolarizing effect that accounts for the decrease in evanescent light enhancement by the surface plasmons and is due to the surface roughness at the interfaces between the metal and dielectric. I also use a tuned metamaterial perforated with a subwavelength array of circular apertures to exhibit extraordinary transmission in the visible. I compare the transmission of the metamaterial to that of a thin film of Ag with equivalent thickness that has fewer plasmon modes and a resonance position in the UV to find that for 400 nm, both thin films exhibit a transmission minimum at 650 nm. Both film spectra have plasmon-aided extraordinary transmission peaks where there is momentum and energy conservation between

  10. Visible Thinking: Application And Evaluation Of Thinking Routines In Primary Education


    Parada Rodríguez, Nerea; Ruiz de Galarreta Galán, Irene


    Producción Científica En el año 1967 Nelson Goodman, con el objetivo de entender y mejorar el aprendizaje, fundó Project Zero, grupo de investigación educativa compuesto por diversos proyectos de investigación entre los cuales se encuentra el proyecto Visible Thinking. Visible Thinking nació en el año 2005 tras años de investigaciones sobre el pensamiento de los niños y su aprendizaje. La idea central del proyecto Visible Thinking es la de hacer visible el pensamiento, ya...

  11. A Study on Visibility Rating of Several Representative Web-Safe Colors (United States)

    Saito, Daisuke; Saito, Keiichi; Notomi, Kazuhiro; Saito, Masao

    This paper presents the visibility ordering of several web-safe colors. The research of web site visibility is important because of the rapid dissemination of the World Wide Web. The combination of a foreground color and a background color is an important factor in providing sufficient visibility. Therefore, the rating of color combination visibility is necessary when developing accessible web sites. In this study, the visibility of several web-safe color combinations was examined using psychological methodology, i.e., a paired comparison. Eighteen chromatic web-safe colors were employed for visual stimuli. Nine students ranging from ages 21 to 29 (average 23.7) were recruited, and all were with normal color sensation. These nine subjects looked at two different colored characters simultaneously on the white background and were instructed to identify which one enabled them to see more clearly. In examining the relationship between the psychological rankings of the color combinations and the visual sensations, each color combination was first scored as to the visibility by Thurstone's paired comparisons technique. Secondly, the visual sensation was deduced by applying Weber-Fechner's law to the luminance of the foreground colors. As results, the luminance of a foreground color influenced the visibility; however the visibility rating is difficult only using the luminance of web-safe colors. These indicate that the chromaticity and chroma saturation are necessary in rating of chromatic web-safe color visibility.

  12. A Study on Visibility Estimation of Web-Safe Colors using Paired Comparison and Discriminant Analysis (United States)

    Saito, Daisuke; Saito, Keiichi; Notomi, Kazuhiro; Saito, Masao

    This paper presents the visibility ordering of several web safe colors. The research of web page visibility is important because of the rapid dissemination of the World Wide Web. The combination of a foreground color and a background color is an important factor in providing sufficient visibility. Therefore, the rating of color combination visibility is necessary when developing accessible web sites. In this study, the visibility of several web-safe color combinations was examined using psychological methodology, i.e., paired comparison. Eighteen chromatic and 3 achromatic web-safe colors were employed for visual stimuli. Twenty-eight subjects ranging from ages 21 to 75 were recruited, and all were with normal color sensation. They looked at two different colored characters simultaneously on the white background and were instructed to identify which one enabled them to see more clearly. In examining the relationship between the psychological rankings of the color combinations and the visual sensations, each color combination was first scored as to the visibility by Thurstone's paired comparison technique. Secondly, the visual sensation was deduced by applying Weber-Fechner's law to the luminance of the foreground colors. As results, the luminance of a foreground color influenced the visibility; however the visibility rating is difficult only using the luminance of web-safe colors. These indicate that the chromaticity and chroma saturation are necessary in rating of chromatic web-safe color visibility.

  13. Coping behavior of women with breast cancer with visible postsurgery deformity

    Directory of Open Access Journals (Sweden)

    Sirota N. A.


    Full Text Available Research was carried out to explore coping strategies in cancer patients. In all, 70 women with breast cancer were studied: 35 of them had visible postsurgery deformity, and 35 did not have visible postsurgery deformity. The purpose of the research was to uncover their preferences for using various strategies and resources to cope with their illness. The results showed that both groups of women had a special set of strategies for coping with stress. The women with visible postsurgery deformity made significantly less use of resources for coping with their illness than did the subgroup of women without visible postsurgery deformity.

  14. Final Report: Non-Visible, Automated Target Acquisition and Tracking

    Energy Technology Data Exchange (ETDEWEB)

    Ziock, Klaus-Peter [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Fabris, Lorenzo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Goddard, James K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hornback, Donald Eric [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Karnowski, Thomas Paul [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Newby, Jason [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)


    The Roadside Tracker (RST) represents a new approach to radiation portal monitors. It uses a combination of gamma-ray and visible-light imaging to localize gamma-ray radiation sources to individual vehicles in free-flowing, multi-lane traffic. Deployed as two trailers that are parked on either side of the roadway (Fig. 1); the RST scans passing traffic with two large gamma-ray imagers, one mounted in each trailer. The system compensates for vehicle motion through the imager’s fields of view by using automated target acquisition and tracking (TAT) software applied to a stream of video images. Once a vehicle has left the field of view, the radiation image of that vehicle is analyzed for the presence of a source, and if one is found, an alarm is sounded. The gamma-ray image is presented to the operator together with the video image of the traffic stream when the vehicle was approximately closest to the system (Fig. 2). The offending vehicle is identified with a bounding box to distinguish it from other vehicles that might be present at the same time. The system was developed under a previous grant from the Department of Homeland Security’s (DHS’s) Domestic Nuclear Detection Office (DNDO). This report documents work performed with follow-on funding from DNDO to further advance the development of the RST. Specifically, the primary thrust was to extend the performance envelope of the system by replacing the visible-light video cameras used by the TAT software with sensors that would allow operation at night and during inclement weather. In particular, it was desired to allow operation after dark without requiring external lighting. As part of this work, the system software was also upgraded to allow the use of 64-bit computers, the current generation operating system (OS), software development environment (Windows 7 vs. Windows XP, and current Visual Studio.Net), and improved software version controls (GIT vs. Source Safe.) With the upgraded performance allowed by

  15. "YouTube Geology" - Increasing Geoscience Visibility Through Short Films (United States)

    Piispa, E. J.; Lerner, G. A.


    Researchers have the responsibility to communicate their science to a broad audience: scientists, non-scientist, young and old. Effective ways of reaching these groups include using pathways that genuinely spark interest in the target audience. Communication techniques should evolve as the means of communication evolve. Here we talk about our experiences using short films to increase geoscience visibility and appreciation. At a time when brevity and quick engagement are vital to capturing people's attention, creating videos that fit popular formats is an effective way to draw and hold people's interest, and spreading these videos on popular sites is a good way to reach a non-academic audience. Creating videos that are fun, exciting, and catchy in order to initially increase awareness and interest is equally important as the educational content. The visual medium can also be powerful way to make complex scientific concepts seem less intimidating. We have experimented with this medium of geoscience communication by creating a number of short films that target a variety of audiences: short summaries of research topics, mock movie trailers, course advertisements, fieldwork highlight reels and geology lessons for elementary school children. Our two rules of thumb are to put the audience first and use style as a vital element. This allows for the creation of films that are more engaging and often less serious than standard informational (and longer-format) videos. Science does not need to be dry and dull - it can be humorous and entertaining while remaining highly accurate. Doing these short films has changed our own mindset as well - thinking about what to film while doing research helps keep the practical applications of our research in focus. We see a great deal of potential for collaboration between geoscientists and amateur or professional filmmakers creating hip and edgy videos that further raise awareness and interest. People like movies. We like movies. We like

  16. A Tighter Bound for the Determinization of Visibly Pushdown Automata

    Directory of Open Access Journals (Sweden)

    Nguyen Van Tang


    Full Text Available Visibly pushdown automata (VPA, introduced by Alur and Madhusuan in 2004, is a subclass of pushdown automata whose stack behavior is completely determined by the input symbol according to a fixed partition of the input alphabet. Since its introduce, VPAs have been shown to be useful in various context, e.g., as specification formalism for verification and as automaton model for processing XML streams. Due to high complexity, however, implementation of formal verification based on VPA framework is a challenge. In this paper we consider the problem of implementing VPA-based model checking algorithms. For doing so, we first present an improvement on upper bound for determinization of VPA. Next, we propose simple on-the-fly algorithms to check universality and inclusion problems of this automata class. Then, we implement the proposed algorithms in a prototype tool. Finally, we conduct experiments on randomly generated VPAs. The experimental results show that the proposed algorithms are considerably faster than the standard ones.

  17. Photooxidation of anthracene under visible light with metallocarboxyphenylporphyrins

    Directory of Open Access Journals (Sweden)

    Carlos Enrique Díaz-Uribe


    Full Text Available En este trabajo sintetizamos metalocarboxifenilporfirinas (TcPP-M, M= Cu y Zn y la carboxifenilporfirina libre de metal (TcPPH y determinamos su eficiencia en la fotooxidación de antraceno bajo luz visible a través de la generación de oxígeno singulete ( 1 O 2 . La presencia de 1 O 2 fue evidenciada por Resonancia Paramagnética Electrónica (RPE, el cual el oxígeno singulete reacciona con la 2,2,6,6-tetrametil-4-piperidona-N (TEMP para producir el radical 2,2,6,6-tetrametil-4-piperidona-N-oxil (TEMPO. Los resultados catalíticos indican que la incorporación del metal en el anillo de la porfirina afecta su eficiencia sobre la oxidación del antraceno. La TcPPH mostró la eficiencia fotónica más alta en la conversión de antraceno (31 % en comparación con la TcPPZn (13 % y TcPPCu (9 %. Estos resultados pueden ser relacionados a la distorsión de la planaridad del anillo de porfirina. Finalmente se detectó la formación de antraquinona y oxoantrona como productos de oxidación in la reacción del antraceno con 1 O 2.

  18. Visible to IR transducer-based infrared image projection systems (United States)

    Berisset, Philippe; Maurel, Frederic


    DGA/DCE/LRBA (Laboratoire de Recherches Balistiques et Aerodynamiques), the French MoD missiles and navigation evaluation center has developed several HWIL facilities in order to test the IR-autoguidance-loops of tactical missiles. This IR autoguidance laboratory is composed of several IR image projection systems based on a visible to IR transduction principle. A previous paper has presented the 1999 achievements of LRBA in this field of research. This new paper first describes the latest evolutions achieved by LRBA in this domain, and then details the image projection layouts based on these improvements. It consists in two main facilities: a ground target scene projection layout and a much more complex animated air target scene projection system. This second testbed features the simultaneous use of a low temperature scene projection layout and three high temperature channels designed to modelize the hot parts of an aircraft and its environment. This allows the delivery of continuous images (100% fill factor) for anti-aircraft missile evaluation, at a relatively low cost. The optimization of this facility and especially the channels synchronization and spatial superposition is also discussed. As a conclusion, future HWIL facilities are presented.

  19. Exploitation of combined visible hyperspectral and infrared imagery (United States)

    Smith, Geoffrey B.; Marmorino, George O.; Miller, W. David


    Natural and anthropogenic surfactants accumulate at the air-sea interface, forming microlayer films, slicks, and foam patches. The resulting enhanced viscoelasticity of the interface alters the small-scale wave spectrum and near-surface turbulence. These changes alter the surface thermal boundary layer and ``skin'' temperature, making infrared thermal imagery ideal for detecting/mapping/studying ocean slicks. Slicks are found under a range of conditions and can result from physical straining of the sea surface (e.g. internal waves) as well as from local biological processes (e.g. plankton blooms). Airborne datasets that combine simultaneous airborne infrared and visible wavelength hyperspectral remote sensing data are now available and provide new opportunities to investigate the physical and biological processes that result in ocean slicks. In addition to the multiple sensors, these datasets are at spatial and time scales much smaller than possible with available satellite remote sensors. This enables the study of a much broader range of phenomena. In particular we investigate the relationship between surface accumulations of vegetative material, ocean slicks and surface temperature changes. We also investigate the relationship between the presence of slicks and water column chromophoric dissolved organic matter (CDOM).

  20. A comparative study of optical concentrators for visible light communications (United States)

    Mulyawan, Rahmat; Gomez, Ariel; Chun, Hyunchae; Rajbhandari, Sujan; Manousiadis, Pavlos P.; Vithanage, Dimali A.; Faulkner, Grahame; Turnbull, Graham A.; Samuel, Ifor D. W.; Collins, Stephen; O'Brien, Dominic


    Given the imminent radio frequency spectrum crunch, Visible Light Communication (VLC) is being proposed as an alternative wireless technology allowing for scalable connectivity to potentially millions of mobile and Internet-of- Things (IoT) devices. A VLC system uses a photo-detector (PD) receiver that converts the optically modulated light from a light source into a modulated electrical signal. The corresponding receiver electrical bandwidth is typically inversely proportional to the PD active area. Consequently, to construct a high-speed VLC link, the PD active area is often substantially reduced and an optical concentrator is used to enhance the receiver collection area. However, to achieve high concentrating factor, the link field-of-view (FOV) needs to be narrow due to the étendue conservation in linear passive optical systems. This paper studies a Fluorescent Concentrator (FC) that breaks this étendue conservation. The FC is not only based on reflective and refractive principles but also makes use of fluorescence process. A comparison between the FC and conventional optical concentrators, namely Compound Parabolic Concentrator (CPC) is also investigated. The trade-off between received signal strength and incoming link angle is demonstrated over 60° coverage. Experimental results show that performance degradation as the link angle increases using FC-based receivers is significantly lower than for conventional CPC.

  1. Phase transition in the parametric natural visibility graph. (United States)

    Snarskii, A A; Bezsudnov, I V


    We investigate time series by mapping them to the complex networks using a parametric natural visibility graph (PNVG) algorithm that generates graphs depending on arbitrary continuous parameter-the angle of view. We study the behavior of the relative number of clusters in PNVG near the critical value of the angle of view. Artificial and experimental time series of different nature are used for numerical PNVG investigations to find critical exponents above and below the critical point as well as the exponent in the finite size scaling regime. Altogether, they allow us to find the critical exponent of the correlation length for PNVG. The set of calculated critical exponents satisfies the basic Widom relation. The PNVG is found to demonstrate scaling behavior. Our results reveal the similarity between the behavior of the relative number of clusters in PNVG and the order parameter in the second-order phase transitions theory. We show that the PNVG is another example of a system (in addition to magnetic, percolation, superconductivity, etc.) with observed second-order phase transition.

  2. Fast Human Detection for Intelligent Monitoring Using Surveillance Visible Sensors

    Directory of Open Access Journals (Sweden)

    Byoung Chul Ko


    Full Text Available Human detection using visible surveillance sensors is an important and challenging work for intruder detection and safety management. The biggest barrier of real-time human detection is the computational time required for dense image scaling and scanning windows extracted from an entire image. This paper proposes fast human detection by selecting optimal levels of image scale using each level’s adaptive region-of-interest (ROI. To estimate the image-scaling level, we generate a Hough windows map (HWM and select a few optimal image scales based on the strength of the HWM and the divide-and-conquer algorithm. Furthermore, adaptive ROIs are arranged per image scale to provide a different search area. We employ a cascade random forests classifier to separate candidate windows into human and nonhuman classes. The proposed algorithm has been successfully applied to real-world surveillance video sequences, and its detection accuracy and computational speed show a better performance than those of other related methods.

  3. Availability and Reliability of FSO Links Estimated from Visibility

    Directory of Open Access Journals (Sweden)

    M. Tatarko


    Full Text Available This paper is focused on estimation availability and reliability of FSO systems. Shortcut FSO means Free Space Optics. It is a system which allows optical transmission between two steady points. We can say that it is a last mile communication system. It is an optical communication system, but the propagation media is air. This solution of last mile does not require expensive optical fiber and establishing of connection is very simple. But there are some drawbacks which have a bad influence of quality of services and availability of the link. Number of phenomena in the atmosphere such as scattering, absorption and turbulence cause a large variation of receiving optical power and laser beam attenuation. The influence of absorption and turbulence can be significantly reduced by an appropriate design of FSO link. But the visibility has the main influence on quality of the optical transmission channel. Thus, in typical continental area where rain, snow or fog occurs is important to know their values. This article gives a description of device for measuring weather conditions and information about estimation of availability and reliability of FSO links in Slovakia.

  4. Visible region MCD and MLD spectra of nitrosylferrohemoglobin and oxyhemoglobin. (United States)

    Pearce, Linda L; Bominaar, Emile L; Peterson, Jim


    Magnetic circular dichroism (MCD) and magnetic linear dichroism (MLD) spectroscopies at various applied magnetic fields (0-6T) and temperatures (2.0-31K) have been used to investigate the electronic properties of the visible (Q(0-0), or alpha band) region of oxy- and nitrosylferrohemoglobin (HbNO). OxyHb, a d(6) (S=0) diamagnet, exhibits the expected pseudo-first derivative MCD and pseudo-second derivative MLD temperature-independent features centered at 574nm. HbNO, a d(7) (S=1/2) paramagnet, also exhibits a temperature-independent pseudo-first derivative MCD spectrum, but centered at 571nm. So far as we are aware, this behavior is unprecedented in the MCD spectra of paramagetic iron-porphyrins, which are expected to be dominated by temperature-dependent C(0) terms. The HbNO MCD spectrum does, however, demonstrate limited field-dependent saturation magnetization behavior and the MLD spectrum is currently below the detection limit. In addition, an MCD signal from reoxygenated venous blood is reported and compared with MCD signals from oxy- and HbNO derivatives. Finally, a combination of MCD and MLD spectroscopies has been used to estimate the orbital angular momentum (M(L)) value of the alpha band excited state of oxyHb as 4.2 (+/-0.7).

  5. Visible skin condition and perception of human facial appearance. (United States)

    Samson, N; Fink, B; Matts, P J


    Evolutionary psychology suggests that certain human beauty standards have evolved to provide reliable cues of fertility and health. Hence, preferences for some physical characteristics of the face and body are thought to reflect adaptations for the promotion of mate choice. Studies that have investigated facial attractiveness have concentrated mainly on features such as symmetry, averageness and sex-typical traits, which are developed under the influence of sex steroids. Few studies, however, have addressed the effect of human skin condition on perception of facial appearance in this context, and possible implications for sexual selection. There is now accumulating evidence that skin pigmentation and skin surface topography cues, particularly in women, have a significant influence on attractiveness judgements, as they seem primarily to signal aspects of age and health. This article (i) reviews briefly some of the main determinants of visible skin condition, (ii) presents recent evidence on its signalling value in face perception and (iii) suggests areas for future research with reference to an evolutionary psychology framework.

  6. Visible light Laue diffraction from woodpile photonic crystals. (United States)

    Brüser, Björn; Staude, Isabelle; von Freymann, Georg; Wegener, Martin; Pietsch, Ullrich


    Bragg diffraction is often used as a tool to assess the structural quality of two-dimensional and three-dimensional (3D) photonic crystals. However, direct conclusions from the Laue diagrams to the underlying crystals structure cannot be drawn, as multiple scattering due to the high index contrast takes place. Here we systematically study the scattering of visible light by 3D woodpile photonic crystals with varying internal refractive index contrast Δn, to determine the limits of the single (kinematic) scattering approach. We aim to describe the intensity distribution of diffracting Bragg peaks with analytic expressions similarly to x-ray scattering at electronic crystals. Measured scattering curves of selected Bragg reflections are classified in terms of Δn. We find that the kinematic approach describes the shape and intensity distribution of experimental scattering curves in acceptable accuracy as long as Δn<0.15. The transition between single and multiple scattering is observed for Δn≈0.16-0.25 before multiple scattering dominates for larger Δn. The classification of the scattering regimes is confirmed by simulations in terms of numerical solution of Maxwell's equations.

  7. Visibility graphs of random scalar fields and spatial data (United States)

    Lacasa, Lucas; Iacovacci, Jacopo


    We extend the family of visibility algorithms to map scalar fields of arbitrary dimension into graphs, enabling the analysis of spatially extended data structures as networks. We introduce several possible extensions and provide analytical results on the topological properties of the graphs associated to different types of real-valued matrices, which can be understood as the high and low disorder limits of real-valued scalar fields. In particular, we find a closed expression for the degree distribution of these graphs associated to uncorrelated random fields of generic dimension. This result holds independently of the field's marginal distribution and it directly yields a statistical randomness test, applicable in any dimension. We showcase its usefulness by discriminating spatial snapshots of two-dimensional white noise from snapshots of a two-dimensional lattice of diffusively coupled chaotic maps, a system that generates high dimensional spatiotemporal chaos. The range of potential applications of this combinatorial framework includes image processing in engineering, the description of surface growth in material science, soft matter or medicine, and the characterization of potential energy surfaces in chemistry, disordered systems, and high energy physics. An illustration on the applicability of this method for the classification of the different stages involved in carcinogenesis is briefly discussed.

  8. Plasmonic and nanophotonics sensors from visible to terahertz (United States)

    Hassani, Alireza

    The global research objective of this thesis is to demonstrate design of novel compact and ultra-sensitive plasmonic sensors operating anywhere from the visible to the THz spectral ranges. The enabling technologies for such sensors are photonic bandgap and microstructured waveguides and fibers containing metallic inclusions. We achieve the stated global objective by systematically addressing several smaller problems. Firstly, this thesis demonstrates plasmonic excitation in metalized microstructured fibers in the context of bio-chemical sensing with enhanced microfluidics for visible and IR ranges. Furthemore, this basic design concept is generalized for the use with photonic bandgap fibers and waveguides; major advantages of using photonic bandgap waveguides in place of Total Internal Reflection (TIR) fibers for plasmonic sensing are discovered. In the first chapter, we discuss the theory of surface plasmons, surface plasmon excitation and sensing methodologies. In the second chapter we show that using microstructured fibers one can solve much easier the problem of phase matching between the surface plasmon wave and fiber core mode, which is common when standard TIR fibers are used. Moreover, the use of microstructured fibers enables integration of the microfluidics and optics during drawing step thus simplifying considerably the sensor fabrication and operation. Furthermore, the different shapes of the metalized surface to enhance the plasmonic excitation were explored with an aim to enhance sensitivity. In the third chapter, the design of photonic crystal waveguide-based surface plasmon resonance sensor is proposed. By judicious design of a photonic crystal waveguide, the effective refractive index of a core mode can be made considerably smaller than that of the core material, thus enabling efficient phase matching with a plasmon, high sensitivity, and high coupling efficiency from an external Gaussian source, at any wavelength of choice from the visible to near

  9. Tunable scattering cancellation cloak with plasmonic ellipsoids in the visible (United States)

    Fruhnert, Martin; Monti, Alessio; Fernandez-Corbaton, Ivan; Alù, Andrea; Toscano, Alessandro; Bilotti, Filiberto; Rockstuhl, Carsten


    The scattering cancellation technique is a powerful tool to reduce the scattered field from electrically small objects in a specific frequency window. The technique relies on covering the object of interest with a shell that scatters light into a far field of equal strength as the object but with a phase shift of π . The resulting destructive interference prohibits its detection in measurements that probe the scattered light. Whereas at radio or microwave frequencies feasible designs have been proposed that allow us to tune the operational frequency upon request, similar capabilities have not yet been explored in the visible. However, such an ability is necessary to capitalize on the technique in many envisioned applications. Here, we solve the problem and study the use of small metallic nanoparticles with an ellipsoidal shape as the material from which the shell is made to build an isotropic geometry. Changing the aspect ratio of the ellipsoids allows us to change the operational frequency. The basic functionality is explored with two complementary analytical approaches. Additionally, we present a powerful multiscattering algorithm that can be used to perform full-wave simulations of clusters of arbitrary particles. We utilize this method to analyze the scattering of the presented designs numerically. Herein we provide useful guidelines for the fabrication of this cloak with self-assembly methods by investigating the effects of disorder.

  10. Indian English Evolution and Focusing Visible Through Power Laws

    Directory of Open Access Journals (Sweden)

    Vineeta Chand


    Full Text Available New dialect emergence and focusing in language contact settings is difficult to capture and date in terms of global structural dialect stabilization. This paper explores whether diachronic power law frequency distributions can provide evidence of dialect evolution and new dialect focusing, by considering the quantitative frequency characteristics of three diachronic Indian English (IE corpora (1970s–2008. The results demonstrate that IE consistently follows power law frequency distributions and the corpora are each best fit by Mandelbrot’s Law. Diachronic changes in the constants are interpreted as evidence of lexical and syntactic collocational focusing within the process of new dialect formation. Evidence of new dialect focusing is also visible through apparent time comparison of spoken and written data. Age and gender-separated sub-corpora of the most recent corpus show minimal deviation, providing apparent time evidence for emerging IE dialect stability. From these findings, we extend the interpretation of diachronic changes in the β coefficient—as indicative of changes in the degree of synthetic/analytic structure—so that β is also sensitive to grammaticalization and changes in collocational patterns.

  11. Thinking in action: thought made visible in contemporary dance. (United States)

    Stevens, Catherine; McKechnie, Shirley


    Contemporary dance-movement deliberately and systematically cultivated for its own sake-is examined in the light of the procedural and declarative view of long-term knowledge. We begin with a description of two settings in which new works of contemporary dance are created and performed. Although non-verbal, contemporary dance can be a language declared through movement and stillness of the body. Ideas for new movement material come from objects, events or imaginings that are spoken, seen, heard, imagined, or felt. Declared through movement, the idea becomes visible. Communication in dance involves general psychological processes such as direct visual perception of motion and force, motor simulation via mirror neurons, and implicit learning of movement vocabularies and grammars. Creating and performing dance appear to involve both procedural and declarative knowledge. The latter includes the role of episodic memory in performance and occasional labelling of movement phrases and sections in rehearsal. Procedural knowledge in dance is augmented by expressive nuance, feeling and communicative intent that is not characteristic of other movement-based procedural tasks. Having delineated lexical and grammatical components in dance, neural mechanisms are identified based on Ullman's (Ullman in Cognition 92:231-270, 2004) alignment of lexical knowledge with declarative memory and mental grammar with procedural memory. We conclude with suggestions for experiments to test these assumptions that concern thought in action in composition, performance and appreciation of contemporary dance.

  12. Mobile health-monitoring system through visible light communication. (United States)

    Tan, Yee-Yong; Chung, Wan-Young


    Promising development in the light emitting diode (LED) technology has spurred the interest to adapt LED for both illumination and data transmission. This has fostered the growth of interest in visible light communication (VLC), with on-going research to utilize VLC in various applications. This paper presents a mobile-health monitoring system, where healthcare information such as biomedical signals and patient information are transmitted via the LED lighting. A small and portable receiver module is designed and developed to be attached to the mobile device, providing a seamless monitoring environment. Three different healthcare information including ECG, PPG signals and HL7 text information is transmitted simultaneously, using a single channel VLC. This allows for a more precise and accurate monitoring and diagnosis. The data packet size is carefully designed, to transmit information in a minimal packet error rate. A comprehensive monitoring application is designed and developed through the use of a tablet computer in our study. Monitoring and evaluation such as heart rate and arterial blood pressure measurement can be performed concurrently. Real-time monitoring is demonstrated through experiment, where non-hazardous transmission method can be implemented alongside a portable device for better and safer healthcare service.

  13. Perovskite Nanocrystals as a Color Converter for Visible Light Communication

    KAUST Repository

    Dursun, Ibrahim


    Visible light communication (VLC) is an emerging technology that uses light-emitting diodes (LEDs) or laser diodes for simultaneous illumination and data communication. This technology is envisioned to be a major part of the solution to the current bottlenecks in data and wireless communication. However, the conventional lighting phosphors that are typically integrated with LEDs have limited modulation bandwidth and thus cannot provide the bandwidth required to realize the potential of VLC. In this work, we present a promising light converter for VLC by designing solution-processed CsPbBr3 perovskite nanocrystals (NCs) with a conventional red phosphor. The fabricated CsPbBr3 NCs phosphor-based white light converter exhibits an unprecedented modulation bandwidth of 491 MHz, which is ~ 40 times greater than that of conventional phosphors, and the capability to transmit a high data rate of up to 2 Gbit/s. Moreover, this perovskite enhanced white light source combines ultrafast response characteristics with a high color rendering index of 89 and a low correlated color temperature of 3236 K, thereby enabling dual VLC and solid-state lighting functionalities.

  14. Portable visible and near-infrared spectrophotometer for triglyceride measurements. (United States)

    Kobayashi, Takanori; Kato, Yukiko Hakariya; Tsukamoto, Megumi; Ikuta, Kazuyoshi; Sakudo, Akikazu


    An affordable and portable machine is required for the practical use of visible and near-infrared (Vis-NIR) spectroscopy. A portable fruit tester comprising a Vis-NIR spectrophotometer was modified for use in the transmittance mode and employed to quantify triglyceride levels in serum in combination with a chemometric analysis. Transmittance spectra collected in the 600- to 1100-nm region were subjected to a partial least-squares regression analysis and leave-out cross-validation to develop a chemometrics model for predicting triglyceride concentrations in serum. The model yielded a coefficient of determination in cross-validation (R2VAL) of 0.7831 with a standard error of cross-validation (SECV) of 43.68 mg/dl. The detection limit of the model was 148.79 mg/dl. Furthermore, masked samples predicted by the model yielded a coefficient of determination in prediction (R2PRED) of 0.6856 with a standard error of prediction (SEP) and detection limit of 61.54 and 159.38 mg/dl, respectively. The portable Vis-NIR spectrophotometer may prove convenient for the measurement of triglyceride concentrations in serum, although before practical use there remain obstacles, which are discussed.

  15. Forward and correctional OFDM-based visible light positioning (United States)

    Li, Wei; Huang, Zhitong; Zhao, Runmei; He, Peixuan; Ji, Yuefeng


    Visible light positioning (VLP) has attracted much attention in both academic and industrial areas due to the extensive deployment of light-emitting diodes (LEDs) as next-generation green lighting. Generally, the coverage of a single LED lamp is limited, so LED arrays are always utilized to achieve uniform illumination within the large-scale indoor environment. However, in such dense LED deployment scenario, the superposition of the light signals becomes an important challenge for accurate VLP. To solve this problem, we propose a forward and correctional orthogonal frequency division multiplexing (OFDM)-based VLP (FCO-VLP) scheme with low complexity in generating and processing of signals. In the first forward procedure of FCO-VLP, an initial position is obtained by the trilateration method based on OFDM-subcarriers. The positioning accuracy will be further improved in the second correctional procedure based on the database of reference points. As demonstrated in our experiments, our approach yields an improved average positioning error of 4.65 cm and an enhanced positioning accuracy by 24.2% compared with trilateration method.

  16. Switchable polarization rotation of visible light using a plasmonic metasurface

    Directory of Open Access Journals (Sweden)

    Stuart K. Earl


    Full Text Available A metasurface comprising an array of silver nanorods supported by a thin film of the phase change material vanadium dioxide is used to rotate the primary polarization axis of visible light at a pre-determined wavelength. The dimensions of the rods were selected such that, across the two phases of vanadium dioxide, the two lateral localized plasmon resonances (in the plane of the metasurface occur at the same wavelength. Illumination with linearly polarized light at 45° to the principal axes of the rod metasurface enables excitation of both of these resonances. Modulating the phase of the underlying substrate, we show that it is possible to reversibly switch which axis of the metasurface is resonant at the operating wavelength. Analysis of the resulting Stokes parameters indicates that the orientation of the principal linear polarization axis of the reflected signal is rotated by 90° around these wavelengths. Dynamic metasurfaces such as these have the potential to form the basis of an ultra-compact, low-energy multiplexer or router for an optical signal.

  17. Solar or UVA-Visible Photocatalytic Ozonation of Water Contaminants. (United States)

    Beltrán, Fernando J; Rey, Ana


    An incipient advanced oxidation process, solar photocatalytic ozonation (SPO), is reviewed in this paper with the aim of clarifying the importance of this process as a more sustainable water technology to remove priority or emerging contaminants from water. The synergism between ozonation and photocatalytic oxidation is well known to increase the oxidation rate of water contaminants, but this has mainly been studied in photocatalytic ozonation systems with lamps of different radiation wavelength, especially of ultraviolet nature (UVC, UVB, UVA). Nowadays, process sustainability is critical in environmental technologies including water treatment and reuse; the application of SPO systems falls into this category, and contributes to saving energy and water. In this review, we summarized works published on photocatalytic ozonation where the radiation source is the Sun or simulated solar light, specifically, lamps emitting radiation to cover the UVA and visible light spectra. The main aspects of the review include photoreactors used and radiation sources applied, synthesis and characterization of catalysts applied, influence of main process variables (ozone, catalyst, and pollutant concentrations, light intensity), type of water, biodegradability and ecotoxicity, mechanism and kinetics, and finally catalyst activity and stability.

  18. Visible camera imaging of plasmas in Proto-MPEX (United States)

    Mosby, R.; Skeen, C.; Biewer, T. M.; Renfro, R.; Ray, H.; Shaw, G. C.


    The prototype Material Plasma Exposure eXperiment (Proto-MPEX) is a linear plasma device being developed at Oak Ridge National Laboratory (ORNL). This machine plans to study plasma-material interaction (PMI) physics relevant to future fusion reactors. Measurements of plasma light emission will be made on Proto-MPEX using fast, visible framing cameras. The cameras utilize a global shutter, which allows a full frame image of the plasma to be captured and compared at multiple times during the plasma discharge. Typical exposure times are ~10-100 microseconds. The cameras are capable of capturing images at up to 18,000 frames per second (fps). However, the frame rate is strongly dependent on the size of the ``region of interest'' that is sampled. The maximum ROI corresponds to the full detector area, of ~1000x1000 pixels. The cameras have an internal gain, which controls the sensitivity of the 10-bit detector. The detector includes a Bayer filter, for ``true-color'' imaging of the plasma emission. This presentation will exmine the optimized camera settings for use on Proto-MPEX. This work was supported by the US. D.O.E. contract DE-AC05-00OR22725.

  19. On the Secrecy Capacity of MISO Visible Light Communication Channels

    KAUST Repository

    Arfaoui, Mohamed Amine


    We study the secrecy capacity of the multiple- input single-output (MISO) Gaussian wiretap visible light communication (VLC) channel. We study a typical VLC scenario with one transmitter, one legitimate receiver, and one eavesdropper. Specifically, we compute the achievable secrecy rate for various input signaling distributions, including the truncated generalized normal (TGN) and uniform distributions. The transmitter is equipped with multiple light sources, while the legitimate and unauthorized receivers are each equipped with a single photodetector. We analyze the achievable secrecy rates via transmit beamforming and artificial noise. In addition, both zero-forcing beamforming and robust beamforming are considered. In the former case, the location of the eavesdropper is assumed to be known, whereas in the latter case, the location of the eavesdropper is unknown. Our numerical results show that the secrecy rate achieved by the TGN distribution is significantly improved as compared to those achieved by the truncated Gaussian and uniform distributions, for both zero-forcing beamforming and robust beamforming. We also derive an upper bound on the achievable secrecy capacity that we used to assess the closeness of the achievable secrecy rates to the derived bound.

  20. Accelerated speckle imaging with the ATST visible broadband imager (United States)

    Wöger, Friedrich; Ferayorni, Andrew


    The Advanced Technology Solar Telescope (ATST), a 4 meter class telescope for observations of the solar atmosphere currently in construction phase, will generate data at rates of the order of 10 TB/day with its state of the art instrumentation. The high-priority ATST Visible Broadband Imager (VBI) instrument alone will create two data streams with a bandwidth of 960 MB/s each. Because of the related data handling issues, these data will be post-processed with speckle interferometry algorithms in near-real time at the telescope using the cost-effective Graphics Processing Unit (GPU) technology that is supported by the ATST Data Handling System. In this contribution, we lay out the VBI-specific approach to its image processing pipeline, put this into the context of the underlying ATST Data Handling System infrastructure, and finally describe the details of how the algorithms were redesigned to exploit data parallelism in the speckle image reconstruction algorithms. An algorithm re-design is often required to efficiently speed up an application using GPU technology; we have chosen NVIDIA's CUDA language as basis for our implementation. We present our preliminary results of the algorithm performance using our test facilities, and base a conservative estimate on the requirements of a full system that could achieve near real-time performance at ATST on these results.

  1. Visible Light Neural Stimulation on graphitic-Carbon Nitride/Graphene Photocatalytic Fibers

    DEFF Research Database (Denmark)

    Zhang, Zhongyang; Xu, Ruodan; Wang, Zegao


    Light stimulation allows remote and spatiotemporally accurate operation that has been applied as effective, non-invasive means of therapeutic interventions. Here, visible light neural stimulation of graphitic carbon nitride (g-C3N4), an emerging photocatalyst with visible-light optoelectronic...

  2. Estimation of visibility of phase contrast with extraction voltages for field emission gun electron microscopes

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Xing, E-mail:


    Estimation was made for visibility of phase contrast with varying extraction voltages. The resulting decay rates of visibility show that images with low image contrast from cryo EM will be seriously impacted with high extraction voltages. - Highlights: • Cryo EM • Phase contrast • Extraction votage.

  3. Computing visible areas from proposed recreation developments...a case study (United States)

    Gary H. Elsner


    A new computerized technique called VIEWIT for measuring the terrain visible from a given point was applied in a study on the Black Hills National Forest, South Dakota. The seen area from 12 heavily visited scenic points and along three proposed routes for a scenic tramway were delineated. The computer produced overlay maps that show the maximum area visible from each...

  4. Visibility Management in School and Beyond: A Qualitative Study of Gay, Lesbian, Bisexual Youth. (United States)

    Lasser, Jon; Tharinger, Deborah


    Proposes visibility management as a key construct in gay, lesbian, and bisexual (GLB) identity development. Visibility management refers to the dynamic, ongoing process by which GLB youth make careful, planned decisions about whether they will disclose their sexual orientation, to whom and how they disclose, and how they continue to monitor the…

  5. Cultural Transmission on the Taskscape: Exploring the Effects of Taskscape Visibility on Cultural Diversity. (United States)

    Premo, L S; Tostevin, Gilbert B


    Culturally transmitted behavior can be structured in its performance both geographically and temporally, in terms of where and when implements are made and used on the landscape (what Ingold calls "the taskscape"). Yet cultural transmission theory has not yet explored the consequences of behaviors transmitted differently due to their enactment at different taskscape locations, what Tostevin calls "taskscape visibility." Here, we use computer simulations to explore how taskscape visibility and forager mobility affect the diversity of two selectively neutral culturally transmitted traits within a single population of social learners. The trait that can be transmitted from residential bases only (lower taskscape visibility) shows greater diversity than the trait that can be transmitted from residential bases and logistical camps (higher taskscape visibility). In addition, increased logistical mobility has a positive effect on the diversity of the trait with the lower taskscape visibility while it generally shows little to no effect on the diversity of the trait with higher taskscape visibility. Without an appreciation for the ways in which taskscape visibility and mobility can structure cultural transmission in space and through time, the difference in the observed equilibrium diversity levels of the two traits might be incorrectly interpreted as resulting from qualitatively different forms of biased cultural transmission. The results of our simulation experiment suggest that researchers may need to take the taskscape visibility into account when inferring cultural transmission from archaeological data.

  6. Outstanding visible photocatalytic activity of a new mixed bismuth titanatate material

    Energy Technology Data Exchange (ETDEWEB)

    Zambrano, P. [Instituto de Ciencia de Materiales de Sevilla, CSIC-Universidad de Sevilla, Americo Vespucio 49, 410092, Sevilla (Spain); Departamento Cristalografía, Mineralogía y Química Agrícola, Universidad de Sevilla, C/Profesor García González s/n, 41012 Sevilla (Spain); Sayagués, M.J.; Navío, J.A. [Instituto de Ciencia de Materiales de Sevilla, CSIC-Universidad de Sevilla, Americo Vespucio 49, 410092, Sevilla (Spain); Hidalgo, M.C., E-mail: [Instituto de Ciencia de Materiales de Sevilla, CSIC-Universidad de Sevilla, Americo Vespucio 49, 410092, Sevilla (Spain)


    Highlights: • Photocatalyst based on bismuth titanates with high visible activity. • Its visible activity as high as UV activity of TiO{sub 2} P25 for phenol degradation. • Photocatalyst is majority of phase Bi{sub 20}TiO{sub 32} with Bi{sub 4}Ti{sub 3}O{sub 12} and amorphous TiO{sub 2}. • High visible activity due to low BG, interconnected phases and high surface area. - Abstract: In this work, a new photocatalyst based on bismuth titanates with outstanding visible photocatalytic activity was prepared by a facile hydrothermal method. The synthesised material showed visible activity as high as UV activity of commercial TiO{sub 2} P25 under the same experimental conditions for phenol degradation. A wide characterisation of the photocatalyst was performed. The material was composed of three phases; majority of Bi{sub 20}TiO{sub 32} closely interconnected to Bi{sub 4}Ti{sub 3}O{sub 12} and amorphous TiO{sub 2}. The high visible activity showed by this material could be ascribed to a combination of several features; i.e. low band gap energy value (2.1 eV), a structure allowing a good separation path for visible photogenerated electron-holes pairs and a relatively high surface area. This photocatalyst appeared as a promising material for solar and visible applications of photocatalysis.

  7. Proximity and Visibility of Fruits and Vegetables Influence Intake in a Kitchen Setting among College Students (United States)

    Privitera, Gregory J.; Creary, Heather E.


    The hypothesis that participants will eat more fruits (apple slices) and vegetables (carrot cuts) if they are made more proximate and visible was tested using a 2 × 2 between-participants design. Proximity was manipulated by placing fruits and vegetables in a bowl at a table where participants sat (near) or 2 m from the table (far). Visibility was…

  8. Demonstration of Magnetic Dipole Resonances of Dielectric Nanospheres in the Visible Region

    DEFF Research Database (Denmark)

    Evlyukhin, A. B.; Novikov, S. M.; Zywietz, U.


    dipole excitation. Due to high permittivity, the magnetic dipole resonance is observed in the visible spectral range for Si nanoparticles with diameters of similar to 200 nm, thereby opening a way to the realization of isotropic optical metamaterials with strong magnetic responses in the visible region....

  9. Making Thinking Visible: How to Promote Engagement, Understanding, and Independence for All Learners (United States)

    Ritchhart, Ron; Church, Mark; Morrison, Karin


    Visible Thinking is a research-based approach to teaching thinking, begun at Harvard's Project Zero, that develops students' thinking dispositions, while at the same time deepening their understanding of the topics they study. Rather than a set of fixed lessons, Visible Thinking is a varied collection of practices, including thinking routines…

  10. Does the Direction in Which a Figure Is Looking Influence Whether It Is Visible? (United States)

    McGuigan, Nicola


    Previous studies have shown that young preschool children are highly sensitive to mutual engagement and struggle to diagnose the visibility of a figure when their facial area is occluded. The present study aimed to explore the specificity of engagement by varying (a) the orientation of a figure relative to an observer and (b) the visible area of…

  11. Enhancing optical absorption of metal–organic frameworks for improved visible light photocatalysis

    NARCIS (Netherlands)

    Nasalevich, M.A.; Goesten, M.G.; Savenije, T.J.; Kapteijn, F.; Gascon, J.


    NH2-MIL-125(Ti) has been post-synthetically functionalized with dye-like molecular fragments. The new material (methyl red-MIL- 125(Ti)) exhibits improved light absorption over a wide range of the visible spectrum, and shows enhanced photocatalytic oxidation activity under visible light

  12. Evaluation of Driver Visibility from Mobile LIDAR Data and Weather Conditions (United States)

    González-Jorge, H.; Díaz-Vilariño, L.; Lorenzo, H.; Arias, P.


    Visibility of drivers is crucial to ensure road safety. Visibility is influenced by two main factors, the geometry of the road and the weather present therein. The present work depicts an approach for automatic visibility evaluation using mobile LiDAR data and climate information provided from weather stations located in the neighbourhood of the road. The methodology is based on a ray-tracing algorithm to detect occlusions from point clouds with the purpose of identifying the visibility area from each driver position. The resulting data are normalized with the climate information to provide a polyline with an accurate area of visibility. Visibility ranges from 25 m (heavy fog) to more than 10,000 m (clean atmosphere). Values over 250 m are not taken into account for road safety purposes, since this value corresponds to the maximum braking distance of a vehicle. Two case studies are evaluated an urban road in the city of Vigo (Spain) and an inter-urban road between the city of Ourense and the village of Castro Caldelas (Spain). In both cases, data from the Galician Weather Agency (Meteogalicia) are used. The algorithm shows promising results allowing the detection of particularly dangerous areas from the viewpoint of driver visibility. The mountain road between Ourense and Castro Caldelas, with great presence of slopes and sharp curves, shows special interest for this type of application. In this case, poor visibility can especially contribute to the run over of pedestrians or cyclists traveling on the road shoulders.

  13. D Object Classification Based on Thermal and Visible Imagery in Urban Area (United States)

    Hasani, H.; Samadzadegan, F.


    The spatial distribution of land cover in the urban area especially 3D objects (buildings and trees) is a fundamental dataset for urban planning, ecological research, disaster management, etc. According to recent advances in sensor technologies, several types of remotely sensed data are available from the same area. Data fusion has been widely investigated for integrating different source of data in classification of urban area. Thermal infrared imagery (TIR) contains information on emitted radiation and has unique radiometric properties. However, due to coarse spatial resolution of thermal data, its application has been restricted in urban areas. On the other hand, visible image (VIS) has high spatial resolution and information in visible spectrum. Consequently, there is a complementary relation between thermal and visible imagery in classification of urban area. This paper evaluates the potential of aerial thermal hyperspectral and visible imagery fusion in classification of urban area. In the pre-processing step, thermal imagery is resampled to the spatial resolution of visible image. Then feature level fusion is applied to construct hybrid feature space include visible bands, thermal hyperspectral bands, spatial and texture features and moreover Principle Component Analysis (PCA) transformation is applied to extract PCs. Due to high dimensionality of feature space, dimension reduction method is performed. Finally, Support Vector Machines (SVMs) classify the reduced hybrid feature space. The obtained results show using thermal imagery along with visible imagery, improved the classification accuracy up to 8% respect to visible image classification.

  14. Sea ice growth rates from tide-driven visible banding (United States)

    Turner, Kate E.; Smith, Inga J.; Tison, Jean-Louis; Verbeke, Véronique; McGuinness, Mark; Ingham, Malcolm; Vennell, Ross; Trodahl, Joe


    In this paper, periodic tide-current-driven banding in a sea-ice core is demonstrated as a measure of the growth rate of first-year sea ice at congelation-ice depths. The study was performed on a core from the eastern McMurdo Sound, exploiting the well-characterized tidal pattern at the site. It points the way to a technique for determining early-season ice growth rates from late-season cores, in areas where under ice currents are known to be tidally dominated and the ice is landfast, thus providing data for a time of year when thin ice prevents direct thickness (and therefore growth rate) measurements. The measured results were compared to the growth-versus-depth predicted by a thermodynamic model.type="synopsis">type="main">Plain Language SummaryIt is currently very difficult to measure sea-ice growth rates, due to the danger of traveling on thin ice early in the growing season. This paper introduces the use of tidal patterns to determine sea-ice growth rates at the end of the growing season, when ice cores can be taken. The technique utilizes the visible light and dark bands that are often present in sea ice near land, and are driven by changes in the tidal current beneath the ice. As well as being important for climate research, this method could contribute to the understanding biological ecosystems within the ice, by providing a method to date depths in an ice core where particular organisms are observed or samples taken.

  15. The visible burrow system: A view from across the hall. (United States)

    Herman, James P; Tamashiro, Kellie L


    The visible burrow system (VBS) is an ethologically relevant social stress model that creates a distinct dominance hierarchy in rats. Randall Sakai's laboratory performed an impressive series of studies documenting the very different impact of VBS exposure on the brain and behavior of dominants (DOM) and subordinates (SUBs). Hierarchy formation causes pronounced changes in metabolism in SUBs relative to both DOMs and unstressed controls, resulting in marked weight loss and metabolic imbalance. Stress testing revealed multiple phenotypes in the VBS, including DOMs, stress-responsive SUBs and stress-non-responsive SUBs. Stress-responsive SUBs have adrenal hypertrophy and elevated baseline corticosterone, consistent with prolonged HPA axis activation; however, peak acute stress responses are not sensitized. In contrast, stress non-responsive individuals do not mount a response to an acute stress, suggesting HPA axis hypofunction. In brain, SUBs exhibit a pattern of gene regulation consistent with impaired stress inhibition (e.g., hippocampal adrenocorticosteroid receptor down-regulation and dendritic retraction) and drive of stress pathways (e.g., increased locus coeruleus tyrosine hydroxylase expression). The non-responsive phenotype is distinguished by down-regulation of paraventricular nucleus corticotropin releasing hormone expression and enhanced neuropeptide Y expression in amygdala. The brain 'signature' created by VBS hierarchy formation differed substantially from that of another well-studied chronic stress model (chronic variable stress). Thus, the impact of VBS is mediated by neurocircuit mechanisms at least in part distinct that of other chronic stress modalities, and suggests that the nature of the stressor may be an essential consideration in development of treatment strategies for stress-related diseases. Copyright © 2017. Published by Elsevier Inc.

  16. Scotoma Visibility and Reading Rate with Bilateral Central Scotomas. (United States)

    Pratt, Joshua D; Stevenson, Scott B; Bedell, Harold E


    In this experiment, we tested whether perceptually delineating the scotoma location and border with a gaze contingent polygon overlay improves reading speed and reading eye movements in patients with bilateral central scotomas. Eight patients with age-related macular degeneration and bilateral central scotomas read aloud MNRead style sentences with their preferred eye. Eye movement signals from an EyeLink II eyetracker were used to create a gaze contingent display in which a polygon overlay delineating the area of the patient's scotoma was superimposed on the text during 18 of the 42 trials. Blocks of six trials with the superimposed polygon were alternated with blocks of six trials without the polygon. Reading speed and reading eye movements were assessed before and after the subjects practiced reading with the polygon overlay. All of the subjects but one showed an increase in reading speed. A paired-samples t-test for the group as a whole revealed a statistically significant increase in reading speed of 0.075 ± 0.060 (SD) log wpm after reading with the superimposed polygon. Individual subjects demonstrated significant changes in reading eye movements, with the greatest number of subjects demonstrating a shift in the average vertical fixation locus. Across subjects, there was no significant difference between the initial and final reading eye movements in terms of saccades per second, average fixation duration, average amplitude of saccades, or proportion of non-horizontal saccades. The improvement in reading speed (0.075 log wpm or 19%) over the short experimental session for the majority of subjects indicates that making the scotoma location more visible is potentially beneficial for improving reading speed in patients with bilateral central scotomas. Additional research to examine the efficacy of more extended training with this paradigm is warranted.

  17. Using visible remotely sensed data for air quality study (United States)

    Lim, H. S.; MatJafri, M. Z.; Abdullah, K.; Tan, K. C.; Wong, C. J.; Mohd Saleh, N.


    Nowadays, air quality is a major concern in many countries whether in the developed or the developing countries. Due to the high cost and limited number of air pollutant stations in each area, they cannot provide a good spatial distribution of the air pollutant readings over a city. Satellite observations can give a high spatial distribution of air pollution. The objective of this study is to test the feasibility of using Landsat TM for retrieving the concentration of the particulate matter of size less than 10- micron (PM10). The retrieval of surface reflectance is important to obtain the atmospheric reflectance in remotely sensed data and later used for algorithm calibration. In this study, we retrieve the surface reflectance using the relationship between the two visible bands (blue and red) and the mid infrared data at 2.1 μm. We use the assumption that the mid infrared band data is not significantly affected by atmospheric haze. An algorithm was developed based on the aerosol properties to correlate the atmospheric reflectance and PM10. We also evaluate the used of the thermal band in the air quality study which is added into the proposed regression algorithm. The in situ PM10 data were collected simultaneously with the acquired satellite image. A high correlation coefficient (R) was obtained in this study between the measured and predicted PM10 values. Finally, a PM10 map was generated using the proposed algorithm and geometrically corrected. The generated PM10 was also colour coded for visual interpretation and smoothed using an average filter to minimize the random noise. This study indicated that the Landsat TM can be a very good tool for air quality study.

  18. Nonlinear Dynamics of River Runoff Elucidated by Horizontal Visibility Graphs (United States)

    Lange, Holger; Rosso, Osvaldo A.


    We investigate a set of long-term river runoff time series at daily resolution from Brazil, monitored by the Agencia Nacional de Aguas. A total of 150 time series was obtained, with an average length of 65 years. Both long-term trends and human influence (water management, e.g. for power production) on the dynamical behaviour are analyzed. We use Horizontal Visibility Graphs (HVGs) to determine the individual temporal networks for the time series, and extract their degree and their distance (shortest path length) distributions. Statistical and information-theoretic properties of these distributions are calculated: robust estimators of skewness and kurtosis, the maximum degree occurring in the time series, the Shannon entropy, permutation complexity and Fisher Information. For the latter, we also compare the information measures obtained from the degree distributions to those using the original time series directly, to investigate the impact of graph construction on the dynamical properties as reflected in these measures. Focus is on one hand on universal properties of the HVG, common to all runoff series, and on site-specific aspects on the other. Results demonstrate that the assumption of power law behaviour for the degree distribtion does not generally hold, and that management has a significant impact on this distribution. We also show that a specific pretreatment of the time series conventional in hydrology, the elimination of seasonality by a separate z-transformation for each calendar day, is highly detrimental to the nonlinear behaviour. It changes long-term correlations and the overall dynamics towards more random behaviour. Analysis based on the transformed data easily leads to spurious results, and bear a high risk of misinterpretation.

  19. Europa Composition Using Visible to Short Wavelength Infrared Spectroscopy (United States)

    Blaney, Diana L.; Dalton, J. B.; Green, R. O.; Hibbits, K.; McCord, T.; Murchie, S.; Piccioni, G.; Tosi, F.


    One of the major goals of the Jupiter Europa Orbiter (JEO) is to understand the chemistry of Europa's inorganic and organic materials. Europa's surface material composition is controlled by the original materials forming Europa and by their differentiation and chemical alterations. Material is probably still being transported to the surface by active processes in the interior. At the surface, the material is exposed to the effects of vacuum and temperature, irradiated by solar UV, and bombarded by material entrained in Jupiter's magnetic field. The materials on the surface and their distributions are evidence of the processes operating, both endogenic and exogenic. These processes include effects of a subsurface liquid ocean and its chemistry; the mechanisms of material emplacement from below; and photolysis and radiolysis. Visible to Short Wavelength Infrared (VSWIR) spectroscopy is a well-understood technique for mapping key inorganic, organic, and volatile compositions on remote surfaces such as Europa. Key spectral absorption features have been detected in both the icy and the non-icy Europa materials and many important constituents of the surface have been identified or proposed (e.g. hydrated salts, sulfuric acid hydrate, organics, CO2, H2O2, SO2). The determination of planetary surface composition from remote infrared spectroscopy depends upon adequate signal-to-noise, spectral resolution, and spatial scale to distinguish the diagnostic spectral features of the compounds of interest. For icy satellites, laboratory reference spectra obtained at the temperatures of the target bodies are also required. We have compared diagnostic spectral features in cryogenic laboratory spectra of hydrated salts relevant to Europa in order to optimize detection of these materials under realistic mission conditions. Effects of spectral resolution, signal to noise ratio, and areal mixtures are explored to determine the impacts on detection. This work was carried out at the Jet

  20. Nowcasting of Low-Visibility Procedure States with Ordered Logistic Regression at Vienna International Airport (United States)

    Kneringer, Philipp; Dietz, Sebastian; Mayr, Georg J.; Zeileis, Achim


    Low-visibility conditions have a large impact on aviation safety and economic efficiency of airports and airlines. To support decision makers, we develop a statistical probabilistic nowcasting tool for the occurrence of capacity-reducing operations related to low visibility. The probabilities of four different low visibility classes are predicted with an ordered logistic regression model based on time series of meteorological point measurements. Potential predictor variables for the statistical models are visibility, humidity, temperature and wind measurements at several measurement sites. A stepwise variable selection method indicates that visibility and humidity measurements are the most important model inputs. The forecasts are tested with a 30 minute forecast interval up to two hours, which is a sufficient time span for tactical planning at Vienna Airport. The ordered logistic regression models outperform persistence and are competitive with human forecasters.

  1. Outstanding visible photocatalytic activity of a new mixed bismuth titanatate material (United States)

    Zambrano, P.; Sayagués, M. J.; Navío, J. A.; Hidalgo, M. C.


    In this work, a new photocatalyst based on bismuth titanates with outstanding visible photocatalytic activity was prepared by a facile hydrothermal method. The synthesised material showed visible activity as high as UV activity of commercial TiO2 P25 under the same experimental conditions for phenol degradation. A wide characterisation of the photocatalyst was performed. The material was composed of three phases; majority of Bi20TiO32 closely interconnected to Bi4Ti3O12 and amorphous TiO2. The high visible activity showed by this material could be ascribed to a combination of several features; i.e. low band gap energy value (2.1 eV), a structure allowing a good separation path for visible photogenerated electron-holes pairs and a relatively high surface area. This photocatalyst appeared as a promising material for solar and visible applications of photocatalysis.

  2. Enhanced visible light photocatalysis through fast crystallization of zinc oxide nanorods

    Directory of Open Access Journals (Sweden)

    Sunandan Baruah


    Full Text Available Hydrothermally grown ZnO nanorods have inherent crystalline defects primarily due to oxygen vacancies that enhance optical absorption in the visible spectrum, opening up possibilities for visible light photocatalysis. Comparison of photocatalytic activity of ZnO nanorods and nanoparticle films on a test contaminant methylene blue with visible light irradiation at 72 kilolux (klx showed that ZnO nanorods are 12–24% more active than ZnO nanoparticulate films. This can be directly attributed to the increased effective surface area for adsorption of target contaminant molecules. Defects, in the form of interstitials and vacancies, were intentionally created by faster growth of the nanorods by microwave activation. Visible light photocatalytic activity was observed to improve by ≈8% attributed to the availability of more electron deficient sites on the nanorod surfaces. Engineered defect creation in nanostructured photocatalysts could be an attractive solution for visible light photocatalysis.

  3. Search Engine Visibility and Language Availability of Travel and Tourism Websites in Serbia

    Directory of Open Access Journals (Sweden)

    Uglješa Stankov


    Full Text Available The visibility of websites on search engines on the one hand is the basic demand of Internet users, and on the other hand reflects the way website owners create and maintain them. In a large number of tourist sites, the importance of visibility of the domestic tourist sites on the leading search engines is emphasized. The authors have found that travel and tourism websites in Serbia are most visible on the local search engines. For foreign users, in addition to the good visibility, the availability of website content in foreign languages is also important. Only half of the tourist websites in Serbia is available in a foreign language. The research aims to point out to the poor visibility and small availability of content in foreign languages of domestic tourist sites and the need for their improvement.

  4. Evaluation of overhead guide sign sheeting materials to increase visibility and safety for drivers. (United States)

    Obeidat, Mohammed Said; Rys, Malgorzata J; Rys, Andrew; Du, Juan


    Overhead guide sign visibility must increase to improve driver safety on roadways. Two methods increase overhead guide sign visibility: sign illumination and use of retroreflective sheeting materials. This paper compares three types of retroreflective sheeting: Engineering Grade (type I), Diamond Grade (type XI), and High Intensity (type IV). A field experiment was conducted at night using licensed drivers to determine the optimum retroreflective sheeting material that increases sign visibility and legibility. Results showed that, of the three types of retroreflective sheeting, Diamond Grade (type XI) sheeting requires minimum illuminance to be visible, followed by High Intensity (type IV) sheeting. Cost analysis, including labor, maintenance, and material cost components of the three retroreflective sheeting materials, showed that High Intensity (type IV) could increase sign visibility and legibility at night for Departments of Transportation with limited budgets, consequently increasing driver safety on roadways. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Size and refinement edge-shape effects of graphene quantum dots on UV–visible absorption

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ruiqiang; Qi, Shifei; Jia, Jianfeng [School of Chemistry and Materials Science, Shanxi Normal University, Linfen 041004 (China); Key Laboratory of Magnetic Molecules and Magnetic Information Materials, Ministry of Education, Linfen 041004 (China); Torre, Bryna [Department of Physics, University at Buffalo, The State University of New York, Buffalo, NY 14260 (United States); Zeng, Hao [School of Chemistry and Materials Science, Shanxi Normal University, Linfen 041004 (China); Department of Physics, University at Buffalo, The State University of New York, Buffalo, NY 14260 (United States); Wu, Haishun [School of Chemistry and Materials Science, Shanxi Normal University, Linfen 041004 (China); Key Laboratory of Magnetic Molecules and Magnetic Information Materials, Ministry of Education, Linfen 041004 (China); Xu, Xiaohong, E-mail: [School of Chemistry and Materials Science, Shanxi Normal University, Linfen 041004 (China); Key Laboratory of Magnetic Molecules and Magnetic Information Materials, Ministry of Education, Linfen 041004 (China)


    Highlights: • The size effect affects both the visible light absorption and the zigzag edge state. • Zigzag edge state is important than armchair edge state for visible light absorption. • The Seam atoms should be noted for the randomly shaped GQDs. - Abstract: Using the ab initio density-functional theory method, we calculated the size effect and edge shape effect on UV–visible light absorption of different shapes of graphene quantum dots (GQDs). There are two interesting findings in this study. First, the edge shape effect increase with increasing the size of square GQDs. Second, the Seam atoms, located at the boundary between zigzag and armchair edges, hardly contribute to the strongest visible light absorption. This refinement of the edge-shape effect can be found in rectangular, triangular and hexagonal GQDs. This new finding will be useful in applications of GQDs in the visible light absorption nanodevices.

  6. Design to Improve Visibility: Impact of Corridor Width and Unit Shape. (United States)

    Hadi, Khatereh; Zimring, Craig


    This study analyzes 10 intensive care units (ICUs) to understand the associations between design features of space layout and nurse-to-patient visibility parameters. Previous studies have explored how different hospital units vary in their visibility relations and how such varied visibility relations result in different nurse behaviors toward patients. However, more limited research has examined the specific design attributes of the layouts that determine the varied visibility relations in the unit. Changes in size, geometry, or other attributes of design elements in nursing units, which might affect patient observation opportunities, require more research. This article reviews the literature to indicate evidence for the impact of hospital unit design on nurse/patient visibility relations and to identify design parameters shown to affect visibility. It further focuses on 10 ICUs to investigate how different layouts diverge regarding their visibility relations using a set of metrics developed by other researchers. Shape geometry and corridor width, as two selected design features, are compared. Corridor width and shape characteristics of ICUs are positively correlated with visibility. Results suggest that floor plans, which are repeatedly broken down into smaller convex (higher convex fragmentation values), or units, which have longer distances between their rooms or between their two opposite ends (longer relative grid distances), might have lower visibility levels across the unit. The findings of this study also suggest that wider corridors positively affect visibility of patient rooms. Changes in overall shape configuration and corridor width of nursing units may have important effects on patient observation and monitoring opportunities. © The Author(s) 2016.

  7. Characteristics of atmospheric visibility and its relationship with air pollution in Korea. (United States)

    Lee, Jeong-Young; Jo, Wan-Kuen; Chun, Ho-Hwan


    Although analysis of long-term data is necessary to obtain reliable information on characteristics of atmospheric visibility and its relationship with air pollution, it has rarely been performed. Therefore, a long-term evaluation of atmospheric visibility in characteristically different Korean cities, as well as a remote island, during 2001 to 2009, was performed in this study. In general, visibility decreased in the studied areas during the 9-yr study period. In addition, all areas displayed a distinct seasonal trend, with high visibility in the cold season relative to the warm season. Weekday visibility, however, did not significantly differ from weekend visibility. Similarly, the number of days per year for both low (19 km) fluctuated during the study period. Busan (a coastal city) exhibited the highest visibility, with an overall average of 17.6 km, followed by Daegu (a basin city), Ulsan (with concentrated petrochemical industries), Ullungdo (a remote island), and Seoul (the capital of Korea). Visibility was found to be significantly correlated with target air pollutants, except for ozone, for all metropolitan cities, whereas it was significantly correlated only with particulate matter with an aerodynamic diameter <10 μm (PM10) and ozone on the remote island (Ullungdo). Among the metropolitan cities, Seoul exhibited the lowest visibility for both the PM10 standard exceedance and non-exceedance days, followed by Ulsan, Daegu, and Busan. The results of this study can be used to establish effective strategies for improving urban visibility and air quality. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  8. Long-term atmospheric visibility trends in megacities of China, India and the United States. (United States)

    Hu, Yue; Yao, Ling; Cheng, Zhen; Wang, Yungang


    Millions of premature deaths worldwide every year mostly in China and India are contributed by the poor air quality. The atmospheric visibility is a proven indicator of the ambient air quality. In this study, nine megacities were selected, including Beijing, Shanghai and Guangzhou from China, Chicago, Los Angeles (LA) and New York City (NYC) from the United States, and Mumbai, Chennai and Jaipur from India. The data of visibility, aerosol optical depth (AOD), and meteorological factors from 1973 to 2015 were collected. The temporal variations of annual and monthly percentages of bad days (visibility 15km) were evaluated. Visibility of Chicago, LA and NYC gradually improved during the past 43 years and has reached a very good level (good day percentages: 75-88%; bad day percentages: 0 - 4%). Conversely, visibility in Mumbai, Chennai and Jaipur continued deteriorating and suffered an extremely poor visibility situation in recent years (good day percentages: 0; bad day percentages: 6-100%). Likewise, visibility in Beijing, Shanghai and Guangzhou has experienced the worsening period during the industrial development from 1970s and turned better after the 1990s. A strong seasonal pattern of bad day percentages of each year were observed in most cities, especially in the winter, which is caused by the fossil fuel combustion for heating, relatively high relative humidity, and other unfavorable meteorological conditions. The low visibility events occurred more frequently in days with low wind speeds and specific wind directions, further explaining the seasonal patterns of visibility. With population growth from the period of 2000-2010 to the period of 2011-2015, AOD and bad day percentages both increased in Mumbai, Chennai, Jaipur and Beijing while others were relatively stable. This study demonstrated that the macro-control of pollution emissions could effectively reduce air deterioration. The relationships among visibility variation, meteorological, pollutant and

  9. Isotope effects in photo dissociation of ozone with visible light (United States)

    Früchtl, Marion; Janssen, Christof; Röckmann, Thomas


    Ozone (O3) plays a key role for many chemical oxidation processes in the Earth's atmosphere. In these chemical reactions, ozone can transfer oxygen to other trace gases. This is particularly interesting, since O3 has a very peculiar isotope composition. Following the mass dependent fractionation equation δ17O = 0.52 * δ18O, most fractionation processes depend directly on mass. However, O3 shows an offset to the mass dependent fractionation line. Processes, which show such anomalies, are termed mass independent fractionations (MIF). A very well studied example for a chemical reaction that leads to mass independent fractionation is the O3 formation reaction. To what degree O3 destruction reactions need to be considered in order to understand the isotope composition of atmospheric O3 is still not fully understood and an open question within scientific community. We set up new experiments to investigate the isotope effect resulting from photo dissociation of O3 in the Chappuis band (R1). Initial O3 is produced by an electric discharge. After photolysis O3 is collected in a cold trap at the triple point temperature of nitrogen (63K). O3 is then converted to O2 in order to measure the oxygen isotopes of O3 using isotope ratio mass spectrometry. To isolate O3 photo dissociation (R1) from O3 decomposition (R2) and secondary O3 formation (R3), we use varying amounts of carbon monoxide (CO) as O atom quencher (R4). In this way we suppress the O + O3 reaction (R3) and determine the isotope fractionation in R1 and R2 separately. We present first results on the isotope effects in O3 photo dissociation with visible light in the presence of different bath gases. Results are interpreted based on chemical kinetics modeling. (R1) O3 + hυ → O (3P) + O2 (R2) O3 + O (3P) → 2 O2 (R3) O + O2 + M → O3 + M (R4) O (3P) + CO + M → CO2 + M

  10. Fresh Soil Sensing using Visible and Near Infrared Spectroscopy (United States)

    Maleki, M. R.


    Fast, precise and affordable soil analytical techniques are needed for the determination of soil fertility of each zone of a field in site specific land management. The objective of this poster is to demonstrate how nutrients can be estimated from fresh soil using visible (VIS) and near infrared (NIR) spectroscopy method. This could be carried out by summarizing the methodology to develop a calibration model for soil phosphorus with the VIS-NIR spectroscopy method. Obviously, it can be simply extended for other nutrients with the same methodology. A large samples set should be collected from different fields with a wide range of soil type and texture. The samples in this set should be represented a wide range of moisture content and soil nutrient which is desired to be calibrated by the spectroscopy technique. Immediately after sampling, the samples should be kept in a cold room (± 1 °C) until the time of the spectral measurement and the chemical analysis. The samples should be taken from the cold room one hour before the spectral measurement to ensure that the samples were at room temperature and no condensation occurs on the optical instruments. Each soil sample was thoroughly mixed and debris such as plant material and stones were removed. The soil sample was divided into three parts, one part for spectral measurement, another part for chemical analysis and the rest was archived. The part for chemical analysis should be examined for their soil nutrients. A small amount of soil (about 30 g) should be placed in a small plastic petridish (e.g. 7.5 mm depth and 30 mm diameter). The soil in the petridish should be first pressed and then carefully levelled in order to obtain a smooth surface for a maximum light reflectance. Soil samples should be put under the spectrophotometer. Three reflectance spectra should be measured on each soil specimen by rotating the plastic cups over 120°. Having finished measuring, the reflectance data should be put against the chemical

  11. Fusion of infrared and visible images for night-vision context enhancement. (United States)

    Zhou, Zhiqiang; Dong, Mingjie; Xie, Xiaozhu; Gao, Zhifeng


    Because of the poor lighting conditions at night time, visible images are often fused with corresponding infrared (IR) images for context enhancement of the scenes in night vision. In this paper, we present a novel night-vision context enhancement algorithm through IR and visible image fusion with the guided filter. First, to enhance the visibility of poorly illuminated details in the visible image before the fusion, an adaptive enhancement method is developed by incorporating the processes of dynamic range compression and contrast restoration based on the guided filter. Then, a hybrid multi-scale decomposition based on the guided filter is introduced to inject the IR image information into the visible image through a multi-scale fusion approach. Moreover, a perceptual-based regularization parameter selection method is used to determine the relative amount of the injected IR spectral features by comparing the perceptual saliency of the IR and visible image information. This fusion method can successfully transfer the important IR image information into the fused image, and simultaneously preserve the details and background scenery in the input visible image. Experimental results show that the proposed algorithm is able to achieve better context enhancement results in night vision.

  12. The Impact of Visibility on Teamwork, Collaborative Communication, and Security in Emergency Departments: An Exploratory Study. (United States)

    Gharaveis, Arsalan; Hamilton, D Kirk; Pati, Debajyoti; Shepley, Mardelle


    The aim of this study was to examine the influence of visibility on teamwork, collaborative communication, and security issues in emergency departments (EDs). This research explored whether with high visibility in EDs, teamwork and collaborative communication can be improved while the security issues will be reduced. Visibility has been regarded as a critical design consideration and can be directly and considerably impacted by ED's physical design. Teamwork is one of the major related operational outcomes of visibility and involves nurses, support staff, and physicians. The collaborative communication in an ED is another important factor in the process of care delivery and affects efficiency and safety. Furthermore, security is a behavioral factor in ED designs, which includes all types of safety including staff safety, patient safety, and the safety of visitors and family members. This qualitative study investigated the impact of visibility on teamwork, collaborative communication, and security issues in the ED. One-on-one interviews and on-site observation sessions were conducted in a community hospital. Corresponding data analysis was implemented by using computer plan analysis, observation and interview content, and theme analyses. The findings of this exploratory study provided a framework to identify visibility as an influential factor in ED design. High levels of visibility impact productivity and efficiency of teamwork and communication and improve the chance of lowering security issues. The findings of this study also contribute to the general body of knowledge about the effect of physical design on teamwork, collaborative communication, and security.

  13. An Automated Self-Learning Quantification System to Identify Visible Areas in Capsule Endoscopy Images. (United States)

    Hashimoto, Shinichi; Ogihara, Hiroyuki; Suenaga, Masato; Fujita, Yusuke; Terai, Shuji; Hamamoto, Yoshihiko; Sakaida, Isao


    Visibility in capsule endoscopic images is presently evaluated through intermittent analysis of frames selected by a physician. It is thus subjective and not quantitative. A method to automatically quantify the visibility on capsule endoscopic images has not been reported. Generally, when designing automated image recognition programs, physicians must provide a training image; this process is called supervised learning. We aimed to develop a novel automated self-learning quantification system to identify visible areas on capsule endoscopic images. The technique was developed using 200 capsule endoscopic images retrospectively selected from each of three patients. The rate of detection of visible areas on capsule endoscopic images between a supervised learning program, using training images labeled by a physician, and our novel automated self-learning program, using unlabeled training images without intervention by a physician, was compared. The rate of detection of visible areas was equivalent for the supervised learning program and for our automatic self-learning program. The visible areas automatically identified by self-learning program correlated to the areas identified by an experienced physician. We developed a novel self-learning automated program to identify visible areas in capsule endoscopic images.

  14. Public Space and a Knot of Visibility: Genders and Sexualities Exposed

    Directory of Open Access Journals (Sweden)

    Aleksa Milanović


    Full Text Available The notion of visibility and visible appears concentrated around a specific knot, which includes the complexity of an intersection of a presence and visibility. In other words, in order for a visibility to be achieved, the simple presence should be underlined by a specific function, a place that marks its relation to the sociocultural system it exists in. In the cases of gender and sexual minority identities the question of public space and visibility becomes crucial, since minorities are being exposed as otherness in relation to the dominant, heteropatriarchal system that labels them as such. This paper works with the issues of problematic visibilities, using the Pride parade in Belgrade 2009 as a case study, which is directly related to gender and sexual identity positions within the dominant majority-governed system.   Article received: June 3, 2017; Article accepted: June 12, 2017; Published online: October 15, 2017; Original scholarly paper How to cite this article: Milanović, Aleksa. "Public Space and a Knot of Visibility: Genders and Sexualities Exposed." AM Journal of Art and Media Studies 14 (2017: 113-122. doi: 10.25038/am.v0i14.201

  15. Asymmetry and sexual dimorphism of the medial frontal gyrus visible surface in humans

    Directory of Open Access Journals (Sweden)

    Spasojević Goran


    Full Text Available Background/Aim. Studies of visible (extrasulcal surface of the brain hemispheres are not feasible for measurements of the brain size, but are valuable for analysis and quantification of sexual dimorphism and/or asymmetries of the human brain. Morphological and morphometric investigations of the brain may contribute in genetic studies of the human nervous system. The aim of this study was to determine and to quantify sexual dimorphism and the right/left morphological asymmetry of the visible surface of medial frontal gyrus (gyrus frontalis medialis - GFM. Methods. Measurements and analysis of the visible surface of GFM were done on 84 hemispheres (42 brains from the persons of both sexes: 26 males and 16 females, 20-65 years of age. After fixation in 10% formalin and dissection, digital morphometric measurements were performed. We studied these in relation to the side of the hemisphere and the person's sex. Standardized digital AutoCAD planimetry of the visible surface of GFM was enabled by the use of coordinate system of intercommissural line. Results. In the whole sample, the visible surface of the right GFM (21.39 cm2 was statistically significantly greater (p < 0.05 than the left GFM (18.35 cm2 indicating the right/left asymmetry of the visible surface of GFM. Also, the visible surface of the right GFM in the males (22.66 cm2 was significantly greater (p < 0.05 than in the females (19.35 cm2, while the difference in size of the left GFM between the males and the females was not significant (p > 0.05. Conclusion. Morphological analysis of visible surface of GFM performed by digital planimetry showed sexual dimorphism of the visible surface and the presence of right/left asymmetry of GFM.

  16. [Preliminary study on force feedback of acupuncture in virtual reality based on the visible human]. (United States)

    Cheng, Zhuo; Wang, Hai-sheng; Min, You-jiang; Yan, Zhen-guo; Hong, Z Tan; Zhuang, Tian-ge


    This paper discusses the application of virtual reality technology in the 3-D visible human body and acupuncture research. Based on the 3-D visible human fused with the localization information and hierarchy of acupoints, the paper analyzes the force against the needle and haptic rendering during the needle manipulation according to the physical properties of different tissues. A haptic model is constructed to demonstrate the force behaviors during acupuncture, and the force will be produced and passed to the manipulator by a force feedback device. It enriches the contents of 3-D visible human project, provides a dynamic simulation instrument for acupuncture teaching, and supplies a platform for acupuncture research.

  17. Media visibility on the formation of female celebrity: Catarina, a virgin for auction

    Directory of Open Access Journals (Sweden)

    Lígia Campos de Cerqueira Lana


    Full Text Available This article analyzes the role of media visibility in the rise of CatherineMigliorini’s celebrity, famous after putting her virginity up for auction oninternet. The history of the case and its main events, texts written by experts, images and statements of Catarina are investigated from the perspective of women’s visibility transformations. Although media critique, the celebrity Catarina displayed expected abilities of women in media visibility, as the possession of a sexy, young and assertive body, able to be used as capital.

  18. NOAA Climate Data Record (CDR) of Visible and Near Infrared Reflectance from AVHRR, Version 1.0 (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The AVHRR visible gains and offsets convert GAC pixel level counts to radiances and are provided for each visible band encompassing TIROS-N, NOAA-6 through NOAA-19...

  19. Prolegomenon for an ethics of visibility in Hannah Arendt

    Directory of Open Access Journals (Sweden)

    Bethânia Assy


    Full Text Available This paper aims to discuss the Arendtian notions of appearance and perception in order to promote a displacement of those conceptions from the generally associated domain of passive apprehension of the faculty of knowledge towards the domain of a praxiology of action and language, based on an active perception. Arendt's appropriations on the Heideggerian "to take one's place" (sich hin-stellen will be discussed, as well as the Augustinian "finding oneself in the world" (diligere. A twofold disposition of appearance will be distinguished: producing and position, whose transposed to the Arendtian notion of world correspond, respectively, to fabrication (poiesis of the world, man's objective in-between space, and to action (praxis in the world, man's subjective in-between space. Those conceptual replacements, in a broad sense, uphold a closer imbrication between the activities of the mind and acting, stricto sensu, and consequently, foment not only the valorization of the public space, but the visibility of our acts and deeds as well, calling out the dignity of appearance in ethics.Este trabalho tem como objetivo discutir as noções arendtianas de aparência e percepção, a fim de promover um deslocamento dessas concepções do domínio geralmente associado da apreensão passiva da faculdade de conhecimento em direção a uma praxiologia da ação e da linguagem, baseada na percepção ativa. As apropriações de Arendt do "apresentar-se como" (sich hin-stellen heideggeriano serão discutidas, bem como o "achar-se no mundo" (diligere agostiniano. Será feita a distinção de uma dupla disposição da aparência: produção e posição, que transpostas para a noção arendtiana de mundo correspondem, respectivamente, à fabricação (poiesis do mundo, o espaço-entre objetivo do homem, e à ação (praxis no mundo, o espaço-entre subjetivo do homem. Essas substituições conceituais, em sentido mais amplo, sustentam uma imbricação mais pr

  20. Clinical courses and predictors for rebleeding in patients with peptic ulcers and non-bleeding visible vessels: a prospective study.


    Lin, H. J.; Perng, C L; Lee, F. Y.; Lee, C. H.; Lee, S. D.


    Detailed characterisation of non-bleeding visible vessels in terms of colour, size evolution, and time of rebleeding is important in determining the natural history of these lesions. The colour and size of non-bleeding visible vessels were observed endoscopically every day for three days and then every other day until rebleeding or flattening of visible vessels occurred in 140 patients. Rebleeding happened in 61 (44%) patients. Of them, 59 (97%) rebled within 72 hours. Flattening of visible v...

  1. Policing Visible Sexual/Gender Diversity as a Program of Governance

    Directory of Open Access Journals (Sweden)

    Angela Dwyer


    Full Text Available Using interview data on LGBT young people’s policing experiences, I argue policing and security works as a program of government (Dean 1999; Foucault 1991; Rose 1999 that constrains the visibilities of diverse sexuality and gender in public spaces. While young people narrated police actions as discriminatory, the interactions were complex and multi-faceted with police and security working to subtly constrain the public visibilities of ‘queerness’. Same sex affection, for instance, was visibly yet unverifiably (Mason 2002 regulated by police as a method of governing the boundaries of proper gender and sexuality in public. The paper concludes by noting how the visibility of police interactions with LGBT young people demonstrates to the public that public spaces are, and should remain, heterosexual spaces.





    Two simple and sensitive visible spectrophotometric methods are described for the determination of tianeptine inbulk and pharmaceutical preparations based on the formation of colored species with SA- NaNO2-

  3. Alcohol consumption, smoking and development of visible age-related signs

    DEFF Research Database (Denmark)

    Schou, Anne L; Mølbak, Marie-Louise; Schnor, Peter


    and earlobe crease, but not xanthelasmata. CONCLUSIONS: High alcohol consumption and smoking predict development of visible age-related signs. This is the first prospective study to show that heavy alcohol use and smoking are associated with generally looking older than one's actual age.......BACKGROUND: Visible age-related signs indicate biological age, as individuals that appear old for their age are more likely to be at poor health, compared with people that appear their actual age. The aim of this study was to investigate whether alcohol and smoking are associated with four visible...... age-related signs (arcus corneae, xanthelasmata, earlobe crease and male pattern baldness). METHODS: We used information from 11 613 individuals in the Copenhagen City Heart Study (1976-2003). Alcohol intake, smoking habits and other lifestyle factors were assessed prospectively and visible age...

  4. Visible Light Dye-Sensitized Photosensitive Systems: A Comprehensive Study on Photoimaging

    National Research Council Canada - National Science Library

    Gao, Fang; Yang, Yong-yuan


    The visible light dyes were employed to sensitized o-Cl-Hexaarylbiimidazole (o-Cl-HABI). The obtained results suggested that o-Cl-HABI displayed a efficient sensitized photocleavage when exposed to Xenon lamp...

  5. Effects of screen filter on visibility of alphanumeric presentation on CRT and LCD monitors. (United States)

    Zunjic, Aleksandar; Ristic, Ljiljana; Milanovic, Dragan D


    In this paper, a research that deals with the problem of determining of the visibility of the alphanumeric presentation on CRT and LCD screens is presented, in conditions when the screen filters are used, and when they are not used. A methodology that can be used for determination of the visibility of alphanumeric symbols on VDT screens is presented. It is determined the existence of differences in visibility of alphanumeric presentations when screen filters are used, compared to conditions when they are not used. This difference was statistically significant, while the visibility of the presented alphanumeric symbols on CRT and LCD screens that use screen filters is lower than when they are not used. For this reason, the use of protective screen filter is recommended in circumstances where a very high level of glare exists, when the visual fatigue is common appearance and when a user performs a task that does not depend on the detection of stimuli whose RGB values are low.

  6. Social Media Activism at the Margins: Managing Visibility, Voice and Vitality Affects

    National Research Council Canada - National Science Library

    McCosker, Anthony


    This article is concerned with social media activism at the margins and deals with the problem of managing visibility and voice and the role of affect in the emergence of contested publics over time...

  7. Active modulation of visible light with graphene-loaded ultrathin metal plasmonic antennas

    National Research Council Canada - National Science Library

    Yu, Renwen; Pruneri, Valerio; García de Abajo, F Javier


    ... by microelectronic drivers. Here we show that planar nanostructures patterned in ultrathin metal-graphene hybrid films sustain highly tunable plasmons in the visible and near-infrared spectral regions...

  8. An assessment of the visibility of MeSH-indexed medical web catalogs through search engines. (United States)

    Zweigenbaum, P; Darmoni, S J; Grabar, N; Douyère, M; Benichou, J


    Manually indexed Internet health catalogs such as CliniWeb or CISMeF provide resources for retrieving high-quality health information. Users of these quality-controlled subject gateways are most often referred to them by general search engines such as Google, AltaVista, etc. This raises several questions, among which the following: what is the relative visibility of medical Internet catalogs through search engines? This study addresses this issue by measuring and comparing the visibility of six major, MeSH-indexed health catalogs through four different search engines (AltaVista, Google, Lycos, Northern Light) in two languages (English and French). Over half a million queries were sent to the search engines; for most of these search engines, according to our measures at the time the queries were sent, the most visible catalog for English MeSH terms was CliniWeb and the most visible one for French MeSH terms was CISMeF.

  9. 40 CFR 52.28 - Protection of visibility from sources in nonattainment areas. (United States)


    ... life of the source. (h) Monitoring. The Administrator may require monitoring of visibility in any...) Phosphate rock processing plants; (M) Coke oven batteries; (N) Sulfur recovery plants; (O) Carbon black...

  10. The visibility of scientific misconduct: A review of the literature on retracted journal articles (United States)

    Hesselmann, Felicitas; Graf, Verena; Schmidt, Marion; Reinhart, Martin


    Retractions of scientific articles are becoming the most relevant institution for making sense of scientific misconduct. An increasing number of retracted articles, mainly attributed to misconduct, is currently providing a new empirical basis for research about scientific misconduct. This article reviews the relevant research literature from an interdisciplinary context. Furthermore, the results from these studies are contextualized sociologically by asking how scientific misconduct is made visible through retractions. This study treats retractions as an emerging institution that renders scientific misconduct visible, thus, following up on the sociology of deviance and its focus on visibility. The article shows that retractions, by highlighting individual cases of misconduct and general policies for preventing misconduct while obscuring the actors and processes through which retractions are effected, produce highly fragmented patterns of visibility. These patterns resemble the bifurcation in current justice systems. PMID:28943647

  11. Visible and Near-Infrared Leaf Reflectance Spectra, 1992-1993 (ACCP) (United States)

    National Aeronautics and Space Administration — Visible/NIR reflectance spectra data for both fresh and dry leaf samples were collected to determine the relationship of foliar chemical concentrations with...

  12. Thermal-to-visible transducer (TVT) for thermal-IR imaging (United States)

    Flusberg, Allen; Swartz, Stephen; Huff, Michael; Gross, Steven


    We have been developing a novel thermal-to-visible transducer (TVT), an uncooled thermal-IR imager that is based on a Fabry-Perot Interferometer (FPI). The FPI-based IR imager can convert a thermal-IR image to a video electronic image. IR radiation that is emitted by an object in the scene is imaged onto an IR-absorbing material that is located within an FPI. Temperature variations generated by the spatial variations in the IR image intensity cause variations in optical thickness, modulating the reflectivity seen by a probe laser beam. The reflected probe is imaged onto a visible array, producing a visible image of the IR scene. This technology can provide low-cost IR cameras with excellent sensitivity, low power consumption, and the potential for self-registered fusion of thermal-IR and visible images. We will describe characteristics of requisite pixelated arrays that we have fabricated.

  13. The 2007 click it or ticket high-visibility seat belt mobilization : traffic tech. (United States)


    In May 2007 the National Highway Traffic Safety Administration : sponsored the fifth national Click It or Ticket (CIOT) : high-visibility seat belt enforcement mobilization, which followed : the CIOT program model of earned and paid media : publicizi...

  14. CLPX Airborne: Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) Data, Version 1 (United States)

    National Aeronautics and Space Administration — This data set consists of apparent surface reflectance, subpixel snow-covered area and grain size inferred from data acquired by the Airborne Visible/Infrared...

  15. Large Scale Use of Solar Power May be Visible Across Interstellar Distances (United States)

    Scheffer, L. K.


    Large scale solar power must intercept a large amount of the sun's radiation. Optimized panel orientations will then concentrate their reflections into a small subtended angle. These effects make the reflections visible across interstellar distances.

  16. Atmospheric aerosol load morphological classification and retrieved visibility based on lidar backscatter measurements

    CSIR Research Space (South Africa)

    Tesfaye, M


    Full Text Available In this paper, the tropospheric aerosol load morphological classification and its impact on temporal variation of visibility are investigated using a continuous 23-hour single channel CSIR-NLC mobile LIDAR backscatter measurement. The trajectory...

  17. The parametric modified limited penetrable visibility graph for constructing complex networks from time series (United States)

    Li, Xiuming; Sun, Mei; Gao, Cuixia; Han, Dun; Wang, Minggang


    This paper presents the parametric modified limited penetrable visibility graph (PMLPVG) algorithm for constructing complex networks from time series. We modify the penetrable visibility criterion of limited penetrable visibility graph (LPVG) in order to improve the rationality of the original penetrable visibility and preserve the dynamic characteristics of the time series. The addition of view angle provides a new approach to characterize the dynamic structure of the time series that is invisible in the previous algorithm. The reliability of the PMLPVG algorithm is verified by applying it to three types of artificial data as well as the actual data of natural gas prices in different regions. The empirical results indicate that PMLPVG algorithm can distinguish the different time series from each other. Meanwhile, the analysis results of natural gas prices data using PMLPVG are consistent with the detrended fluctuation analysis (DFA). The results imply that the PMLPVG algorithm may be a reasonable and significant tool for identifying various time series in different fields.

  18. Design of an ultrabroadband visible metamaterial absorber based on three-dimensional metallic nanostructures (United States)

    Luo, Hao; Cheng, Yong Zhi


    We present the design and numerical simulations of an ultrabroadband visible metamaterial absorber (MMA) with polarization-insensitive and wide-angle based on three-dimensional (3D) metallic nanostructure. Distinct from previous designs, the proposed visible MMA only consisted of structured 3D metallic film constructed with an assembly of four vertical split-rings (FVSR) structure. For the optimized design of our MMA, the absorbance of over 90% with a relative bandwidth of 94.8% can be obtained. Further simulation results indicate that our design is polarization-insensitive and also operated well in a wide range of incident angles for both TE and TM modes. In addition, the designed visible MMA design can tolerate some geometric parameters errors in fabrication. Thus, the proposed visible MMA can be potential application in the photodetectors, thermal imaging, photoelectrochemical, and solar energy harvesting devices.

  19. Visibility Enhancement and Power Saving by Pro-beam LED Tunnel Lighting Method

    National Research Council Canada - National Science Library

    Sato, Motohisa; Hagio, Tomokazu


    .... The pro-beam lighting system however has an advantage to enhance visibility with reversed silhouette and has being investigated for more safe and comfortable driving in the tunnel for several years...


    Directory of Open Access Journals (Sweden)

    Yu. T. Zyryanov


    Full Text Available The paper presents an approach to solving important scientific application at the evaluation of the effectiveness of airfields runway lighting in low visibility conditions using the integral index-based fashion.

  1. Aerobic oxidation of alcohols in visible light on Pd-grafted Ti cluster (United States)

    The titanium cluster with the reduced band gap has been synthesized having the palladium nanoparticles over the surface, which not only binds to the atmospheric oxygen but also catalyzes the oxidation of alcohols under visible light.

  2. NPP Visible Infrared Imager-Radiometer Suite (VIIRS) Quasi-Analytical Algorithm (GSM) Global Mapped Data (United States)

    National Aeronautics and Space Administration — The Visible and Infrared Imager/Radiometer Suite (VIIRS) is a multi-disciplinary instrument that is being flown on the Joint Polar Satellite System (JPSS) series of...

  3. NPP Visible Infrared Imager-Radiometer Suite (VIIRS) Quasi-Analytical Algorithm (GSM) Global Binned Data (United States)

    National Aeronautics and Space Administration — The Visible and Infrared Imager/Radiometer Suite (VIIRS) is a multi-disciplinary instrument that is being flown on the Joint Polar Satellite System (JPSS) series of...

  4. Sustainable Strategy Utilizing Biomass: Visible-Light-Mediated Synthesis of gamma-Valerolactone (United States)

    U.S. Environmental Protection Agency — A novel sustainable approach to valued g-valerolactone was investigated. This approach exploits the visible-light-mediated conversion of biomass-derived levulinic...

  5. Land-sea delineation in the visible channels of Landsat thematic mapper

    Digital Repository Service at National Institute of Oceanography (India)

    Menon, H.B.; Sathe, P.V.

    Accurate coastal mapping using satellite imageries in the visible region is difficult because of the poor contrast between the radiance received from land and sea, respectively and also due to the structures present in the coastal region caused...

  6. NOAA JPSS Visible Infrared Imaging Radiometer Suite (VIIRS) Cloud Mask Environmental Data Record (EDR) from NDE (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains a high quality Environmental Data Record (EDR) of cloud masks from the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument onboard...

  7. High Spatial Resolution Visible Color Units on Mars from the Mars Odyssey THEMIS/VIS Instrument (United States)

    Bell, J. F., III; McConnochie, T.; Savransky, D.; Stiglitz, B.; Wolff, M. J.; Christensen, P. R.; Mehall, G.; James, P. B.; Malin, M.; Caplinger, M.; Ravine, M.; Cherednik, L. L.; Bender, K. C.; Murray, K.; Themis Science Team


    This presentation describes the calibration and new results from the Mars Odyssey THEMIS/VIS instrument, which is obtaining five-color visible wavelength images from Mars orbit at scales of 18 72 m/pixel.

  8. Nanostructure sensitization of transition metal oxides for visible-light photocatalysis (United States)

    Chen, Hongjun


    Summary To better utilize the sunlight for efficient solar energy conversion, the research on visible-light active photocatalysts has recently attracted a lot of interest. The photosensitization of transition metal oxides is a promising approach for achieving effective visible-light photocatalysis. This review article primarily discusses the recent progress in the realm of a variety of nanostructured photosensitizers such as quantum dots, plasmonic metal nanostructures, and carbon nanostructures for coupling with wide-bandgap transition metal oxides to design better visible-light active photocatalysts. The underlying mechanisms of the composite photocatalysts, e.g., the light-induced charge separation and the subsequent visible-light photocatalytic reaction processes in environmental remediation and solar fuel generation fields, are also introduced. A brief outlook on the nanostructure photosensitization is also given. PMID:24991507

  9. Robust Visible and Infrared Light Emitting Devices Using Rare-Earth-Doped GaN

    National Research Council Canada - National Science Library

    Steckl, Andrew


    Rare earth (RE) dopants (such as Er, Eu, Tm) in the wide bandgap semiconductor (WBGS) GaN are investigated for the fabrication of robust visible and infrared light emitting devices at a variety of wavelengths...

  10. NPP Visible Infrared Imager-Radiometer Suite (VIIRS) Remote-Sensing Reflectance (RRS) Global Mapped Data (United States)

    National Aeronautics and Space Administration — The Visible and Infrared Imager/Radiometer Suite (VIIRS) is a multi-disciplinary instrument that is being flown on the Joint Polar Satellite System (JPSS) series of...

  11. NOAA JPSS Visible Infrared Imaging Radiometer Suite (VIIRS) Aerosol Detection Environmental Data Record (EDR) from NDE (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a high quality operational Environmental Data Record (EDR) of suspended matter from the Visible Infrared Imaging Radiometer Suite (VIIRS)...

  12. NOAA JPSS Visible Infrared Imaging Radiometer Suite (VIIRS) Snow Cover Environmental Data Record (EDR) from NDE (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a high quality operational Environmental Data Record (EDR) of snow cover from the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument...

  13. The power conversion efficiency of visible light emitting devices in standard BiCMOS processes

    NARCIS (Netherlands)

    Kuindersma, P.; Hoang, T.; Schmitz, Jurriaan; Vijayaraghavan, M.N.; Dijkstra, Mindert; Dijkstra, M.; van Noort, W.A.; Vanhoucke, T.; Peters, W.C.M.; Kramer, M.C.J.C.M.


    We present experimental and theoretical proof for a single and unique relationship between the breakdown voltage and power efficiency of visible light emitting devices fabricated in standard BiCMOS processes.

  14. NPP Visible Infrared Imager-Radiometer Suite (VIIRS) Chlorophyll (CHL) Global Mapped Data (United States)

    National Aeronautics and Space Administration — The Visible and Infrared Imager/Radiometer Suite (VIIRS) is a multi-disciplinary instrument that is being flown on the Joint Polar Satellite System (JPSS) series of...

  15. NOAA JPSS Visible Infrared Imaging Radiometer Suite (VIIRS) Smoothed Normalized Difference Vegetation Index (NDVI) from NDE (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Visible Infrared Imaging Radiometer Suite (VIIRS) Smoothed Normalized Difference Vegetation Index (NDVI) from NDE is a weekly product derived from the VIIRS...

  16. Giantically blue-shifted visible light in femtosecond mid-IR filament in fluorides

    CERN Document Server

    Dormidonov, A E; Chekalin, S V; Kandidov, V P


    A giant blue shift of an isolated visible band of supercontinuum was discovered and studied in the single filament regime of Mid-IR femtosecond laser pulse at powers slightly exceeding critical power for self-focusing in fluorides.

  17. NOAA JPSS Visible Infrared Imaging Radiometer Suite (VIIRS) Sensor Data Record (SDR) from IDPS (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sensor Data Records (SDRs), or Level 1b data, from the Visible Infrared Imaging Radiometer Suite (VIIRS) are the calibrated and geolocated radiance and reflectance...

  18. Nanostructure sensitization of transition metal oxides for visible-light photocatalysis

    Directory of Open Access Journals (Sweden)

    Hongjun Chen


    Full Text Available To better utilize the sunlight for efficient solar energy conversion, the research on visible-light active photocatalysts has recently attracted a lot of interest. The photosensitization of transition metal oxides is a promising approach for achieving effective visible-light photocatalysis. This review article primarily discusses the recent progress in the realm of a variety of nanostructured photosensitizers such as quantum dots, plasmonic metal nanostructures, and carbon nanostructures for coupling with wide-bandgap transition metal oxides to design better visible-light active photocatalysts. The underlying mechanisms of the composite photocatalysts, e.g., the light-induced charge separation and the subsequent visible-light photocatalytic reaction processes in environmental remediation and solar fuel generation fields, are also introduced. A brief outlook on the nanostructure photosensitization is also given.

  19. Controlled Defects of Zinc Oxide Nanorods for Efficient Visible Light Photocatalytic Degradation of Phenol


    Jamal Al-Sabahi; Tanujjal Bora; Mohammed Al-Abri; Joydeep Dutta


    Environmental pollution from human and industrial activities has received much attention as it adversely affects human health and bio-diversity. In this work we report efficient visible light photocatalytic degradation of phenol using supported zinc oxide (ZnO) nanorods and explore the role of surface defects in ZnO on the visible light photocatalytic activity. ZnO nanorods were synthesized on glass substrates using a microwave-assisted hydrothermal process, while the surface defect states we...

  20. Redox Mediators in Visible Light Photocatalysis: Photocatalytic Radical Thiol?Ene Additions


    Tyson, Elizabeth L.; Niemeyer, Zachary L.; Yoon, Tehshik P.


    Synthetically useful radical thiol?ene reactions can be initiated by visible light irradiation in the presence of transition metal polypyridyl photocatalysts. The success of this method relies upon the use of p-toluidine as an essential additive. Using these conditions, high-yielding thiol?ene reactions of cysteine-containing biomolecules can be accomplished using biocompatibile wavelengths of visible light, under aqueous conditions, and with the thiol component as the limiting reagent. We pr...

  1. Visibility and politics: an Arendtian reading of the US drone policy


    da Mota, S.; Barrinha, A.


    This article analyses the critical connections between drones as lethal technological devices, visibility, and the very possibility of politics. Drawing on Hannah Arendt’s core postulates on politics, modern security and society, it problematises the political implications of using drones as a prominent security instrument in contemporary life. This reading is unpacked through the concept of visibility as a critical reference to analyse how security policies are dealt with politically. It sug...

  2. Distributed Leadership and the Visibility/Invisibility Paradox in On-line Communities


    Jill Jameson


    This paper analyzes the role of distributed leadership in three on-line communities, reflecting on an observed visibility/invisibility paradox in leadership within these communities. Leaders who downplay their seniority and assume a degree of invisibility, allocating discretionary powers to subordinate levels in an organizational hierarchy, may facilitate the emergence of distributed leadership. Yet, simultaneously, leader-led relations are enabled by high leadership visibility. This paradox—...

  3. Inducing visibilities: an attempt at Santiago Ramón y Cajal's aesthetic epistemology. (United States)

    Fiorentini, Erna


    In this paper, I consider Santiago Ramón y Cajal's strategy of histological observation and imaging in terms of what I call "induction of visibility" (Fiorentini, 2011). Cajal's strategy of visibility induction drew upon both rational and aesthetic visual sensibility, and considered this interplay to be a constitutive element of knowledge production. I propose to describe Cajal's fundamental attitude towards visually inferred knowledge in terms of an "aesthetic epistemology". Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Radiographic evaluation of the course and visibility of the mandibular canal

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yun Hoa; Cho, Bong Hae [Dept. of Oral and Maxillofacial Radiology, School of Dentistry, Pusan National University, Yangsan (Korea, Republic of)


    This study was performed to investigate the course of the mandibular canal on panoramic radiography and the visibility of this canal on both panoramic radiography and cone-beam computed tomography (CBCT). The study consisted of panoramic radiographs and CBCT images from 262 patients. The course of the mandibular canal, as seen in panoramic radiographs, was classified into four types: linear, elliptical, spoon-shaped, and turning curves. The visibility of this canal from the first to the third molar region was evaluated by visually determining whether the mandibular canal was clearly visible, probably visible, or invisible. The visibility of the canal on panoramic radiographs was compared with that on CBCT images. Elliptical curves were most frequently observed along the course of the mandibular canal. The percentage of clearly visible mandibular canals was the highest among the spoon-shaped curves and the lowest among the linear curves. On panoramic radiographs, invisible mandibular canals were found in 22.7% of the examined sites in the first molar region, 11.8% in the second molar region, and 1.3% in the third molar region. On CBCT cross-sectional images, the mandibular canal was invisible in 8.2% of the examined sites in the first molar region, 5.7% in the second molar region, and 0.2% in the third molar region. The visibility of this canal was lower in the first molar region than in the third molar region. The mandibular canal presented better visibility on CBCT images than on panoramic radiographs.

  5. Visible continuous-wave laser transitions in Pr(3+):YLF and femtosecond pulse generation. (United States)

    Sutherland, J M; French, P M; Taylor, J R; Chai, B H


    Fourteen new cw, visible laser transitions have been observed in Pr(3+):YLF, several of which have exhibited modest tunability. The (3)P(0) - (3)H(6) transition near 613 nm has been shown to have a tunable linewidth of ~1 nm, which, for the first time to our knowledge, has permitted the direct production of femtosecond pulses in the visible from a cw solid-state laser by Kerr-lens mode locking.

  6. 140-GHz Attenuation and Optical Visibility Measurements of Fog, Rain and Snow (United States)


    or snow storms by their water con- tent or rate of rainfall, optical visibility was also used. In many weapon systems applications, visibility is...Mr. C. Hussey DRDMI-RFC, A. Michetti DRDMI-RFE, Mr. Salonimer DRDMI-RR, Mr. S, Johnston Redstone Arsenal, AL 35809 Commander US Army Missile...Naval Surface Weapons Center ATTN: Library Code DF34 Dahlgren, VA 22448 Commander US Naval Weapons Center ATTN: Mr. R. Moore Mr. R. Higuera

  7. Land-Sea Delineation in the Visible Channels of Landsat Thematic Mapper


    Harilal B. Menon; P.V. Sathe


    Accurate coastal mapping using satellite imageries in the visible region is difficult because of the poor contrast between the radiance received from land and sea, respectively and also due to the structures present in the coastal region caused by chlorophyll, suspended sediments, etc. A method has been suggested to enhance the utility of visible imageries for precise land-sea delineation and detection of tiny islands and extraneous objects in the sea. This method is based on contrast...

  8. Quantum electron plasma, visible and ultraviolet P-wave and thin metallic film

    Energy Technology Data Exchange (ETDEWEB)

    Yushkanov, A.A., E-mail:; Zverev, N.V., E-mail:


    The interaction of the visible and ultraviolet electromagnetic P-wave with the thin flat metallic film localized between two dielectric media is studied numerically in the framework of the quantum degenerate electron plasma approach. The reflectance, transmittance and absorptance power coefficients are chosen for investigation. It is shown that for the frequencies in the visible and ultraviolet ranges, the quantum power coefficients differ from the ones evaluated in framework of both the classical spatial dispersion and the Drude–Lorentz approaches.

  9. Selective Reactivity, Ultrafast Energy Transfer and the Development of Chemically Pumped Visible Lasers (United States)


    the lne -or evew-hq instructions. searmnnq exott’q data wutrces. awirng the cctrec’Ton of’ nformation Send ,om rents egr • lomg this O.roen est crmate...additional analog systems suggests that the two concepts considered will be generic, 14. SUBJECT TERMS 1S. NUMBER OF PAGES Visible Chem. Lasers, Energy...successful production of visible chemical laser amplifiers using the highly efficient and selective formation of alkali dimer, M2 = Na2 , (Li 2 ), excited

  10. Employment Discrimination against Visible Minorities and Employment Equity = Discrimination dans L'emploi a L'egard des Minorites Visibles et Equite en Matiere D'emploi. (United States)

    Jain, Harish C.

    Canada has become a multiracial, multireligious, and multicultural society, but non-whites, the "visible minorities (VMs)," face pay and employment discrimination in both the public and the private sector. Lack of statistical data by race and by region about job segregation, income levels, and promotions make it difficult to determine…

  11. Accuracy of visible plaque identification by pediatric clinicians during well-child care. (United States)

    Dumas, S Amanda; Weaver, Katelynn E; Park, Seo Young; Polk, Deborah E; Weyant, Robert J; Bogen, Debra L


    Assess pediatric providers' ability to identify visible plaque on children's teeth. Pediatric providers (residents, nurse practitioners, and attendings) conducting well-child care on 15-month to 5-year-olds in an academic practice examined children's maxillary incisors for visible plaque (recorded yes/no). A dental hygienist then examined the children and recorded the degree of visible plaque present. The children's mean age was 34 months (±15 months), and 50% had visible plaque. Providers (n = 28) identified visible plaque on 39% of children (n = 118), with 55% sensitivity and 80% specificity, and agreement with hygienist measured as a κ score was 0.34. Subgroup analyses (based on provider training level, exam experience, child age, and plaque scores) did not appreciably improve sensitivity, specificity, positive predictive value, negative predictive value, or κ scores. Visible plaque exams performed during well-child care may not be accurate. To comply with caries-risk assessment guidelines, providers require further education in oral exams.

  12. Periodontal Biotype: Gingival Thickness as It Relates to Probe Visibility and Buccal Plate Thickness. (United States)

    Frost, Natalie A; Mealey, Brian L; Jones, Archie A; Huynh-Ba, Guy


    Probe visibility is the clinical gold standard to discriminate thick from thin biotype but is prone to subjective interpretation. The primary objective of this study is to determine at what objective gingival thickness the probe becomes invisible through the tissue. A secondary objective is to compare mean buccal plate thickness between thick and thin biotypes as determined by probe visibility. Maxillary anterior teeth (n = 306) were studied in 56 human patients. Biotype was determined by probe visibility through the tissue. Gingival thickness was measured via transgingival sounding. Buccal plate thickness was measured (n = 66 teeth) by cone beam computed tomography. For the primary objective, the gingival thickness that best corresponded with probe invisibility was selected using the receiver operating characteristic and area under the curve (AUC) with the highest combination of sensitivity and specificity. For the secondary objective, mean buccal plate thickness was compared between sites in which the probe was visible and when it was not (Student t test, α= 0.05). The gingival thickness that most closely corresponded with probe invisibility was >0.8 mm (0.666 AUC, 67.7% sensitivity, 65.4% specificity). When the probe was visible, mean gingival thickness was 0.17 mm less (P biotype) and those in which it was not (i.e., thick biotype). Probe visibility was associated with thinner measurements of gingival thickness and showed a tendency to be associated with a thinner buccal plate.

  13. Can hospital dashboards provide visibility of information from bedside to board? A case study approach. (United States)

    Pace, Adriana; Buttigieg, Sandra C


    Purpose The purpose of this paper is to analyse hospital dashboards' visibility of information at different management levels to improve quality and performance in an acute general hospital. Design/methodology/approach Data were generated via 21 semi-structured interviews across different management levels. Findings All management levels had greater visibility of information, could make informed decisions, and registered performance improvement. Specifically, waiting time improved, however since introduction of hospital dashboards was work-in-progress at time of study, managers could not record improvement in terms of cost reductions, clinical effectiveness, patient safety and patient satisfaction. Different managerial levels had different visibility with top management having the greatest. Research limitations/implications In single case studies, where only one context is used, the findings cannot be reproduced in different contexts; even though most of the results could be matched with the current literature. Practical implications The need to have balanced key performance indicators that take into account other facets of improvements, apart from time, has been emphasised. Furthermore, if middle and departmental managers have greater visibility, this would allow them to work towards a strategic fit between the departments that they manage with the rest of the hospital. Originality/value There is scant literature regarding performance dashboards' enhancement of visibility of information at different management levels. Furthermore, according to the authors' knowledge, no other paper has tried to identify and discuss the different levels of information, which should be visible from bedside to board namely to management, clinicians and public.

  14. Predicting the visibility of a chemical vapor plume using schlieren optics (United States)

    Bigger, Rory; Settles, Gary


    Chemicals plumes from a freely-evaporating liquid surface and from the exit of a circular pipe are considered. For the freely-evaporating case, the visibility of fourteen chemicals was tested in two schlieren optical systems. One system was a modest bench-top system and the other was a lard system of extraordinary sensitivity. Plume visibility was found to be a function of the vapor pressure and vapor refractive index. An empirical fit to the plume-visibility data, compared with the sensitivities of these systems (measured using a standard-lens method), suggests guidelines for predicting the visibility of plumes of other chemicals using other schlieren equipment. For the circular opening case, plume visibility of the same chemicals was found to be a function of plume geometry and refractive index. The peak light-ray deflections (also measured with a standard lens) caused by plumes of two different sizes were found to scale based on plume geometry. This scaling information and plume refractive index can be used to predict plume visibility for arbitrary chemicals in arbitrary systems, if the system sensitivity is known. One application of this work lies in the optical detection of plumes emitted by contraband material.

  15. UV Blocking Glass: Low Cost Filters for Visible Light Photocatalytic Assessment

    Directory of Open Access Journals (Sweden)

    Charles W. Dunnill


    Full Text Available A number of commercially available art protection products have been compared and assessed for their suitability as UV blocking filters in the application of “visible light” photocatalytic research. Many groups claiming visible light photocatalytic success employ filters to block out stray UV radiation in order to justify that their photocatalysts are indeed visible light photocatalysts and not UV light photocatalysts. These filters come in varying degrees of ability and price and many authors fail to correctly characterise their filters in individual papers. The use of effective filters to prevent both false positive and false negative results is important to maintain scientific rigor and create accurate understanding of the subject. The optimum UV filter would have the highest UV blocking properties (<390 nm and simultaneously the highest visible light transmission (390–750 nm. Single and double layers of each of the glass products were assessed as well as laminate products. The conclusions show an inexpensive and highly effective setup for the conduction of visible light photochemistry that should be incorporated as a standard part in any researcher’s work where the claim of visible light activity is made.

  16. Efficient Prediction of Low-Visibility Events at Airports Using Machine-Learning Regression (United States)

    Cornejo-Bueno, L.; Casanova-Mateo, C.; Sanz-Justo, J.; Cerro-Prada, E.; Salcedo-Sanz, S.


    We address the prediction of low-visibility events at airports using machine-learning regression. The proposed model successfully forecasts low-visibility events in terms of the runway visual range at the airport, with the use of support-vector regression, neural networks (multi-layer perceptrons and extreme-learning machines) and Gaussian-process algorithms. We assess the performance of these algorithms based on real data collected at the Valladolid airport, Spain. We also propose a study of the atmospheric variables measured at a nearby tower related to low-visibility atmospheric conditions, since they are considered as the inputs of the different regressors. A pre-processing procedure of these input variables with wavelet transforms is also described. The results show that the proposed machine-learning algorithms are able to predict low-visibility events well. The Gaussian process is the best algorithm among those analyzed, obtaining over 98% of the correct classification rate in low-visibility events when the runway visual range is {>}1000 m, and about 80% under this threshold. The performance of all the machine-learning algorithms tested is clearly affected in extreme low-visibility conditions ({algorithm performance in daytime and nighttime conditions, and for different prediction time horizons.

  17. Seeing Is Believing: on the Visibility of Late Capitalism

    Directory of Open Access Journals (Sweden)

    Gordan Maslov


    capitalist reality which in appearance is neither true nor false but rather ‘objective illusion’. And yet concepts that aim to grasp this eluding totality – including the very term ‘capitalism’ – can rarely be found in Capital. This leads Jameson to conclude that Marx, after a well-documented laborious reworking of the opening chapters and the overall structure of Capital, found out that the accumulation of capital can be made visible only in its symptoms, distortions, crisis, and different cuts of structure. This return to the now famous Slavoj Žižek proposition that “Marx invented the symptom” (Žižek 1 is followed up with an even more far-reaching conclusion: the only possible Marxian totality of capitalism has a Freudian structure and is a result of a combination of different but ultimately partial representations unable to fully capture its field of phenomena. Jameson himself is unwilling to follow up the full implication of this parallel; insofar as Marxian capitalist totality can only be an aesthetic construct – or, to use psychoanalytic vocabulary, a ‘compromise formation’ – built for strategic purposes, it remains just one amongst other totalities, competing with them in a terrain not overdetermined by any recourse to economic objectivity. In order to avoid this, Jameson takes the road of Marx’s dialectic which for him resolves the duality of objectivism – economic determinism – and voluntarism underlying the whole history of Marxist theory. In actualizing Marx’s dialectics, Jameson is not returning to the mystic source itself as much as reading Marx via and alongside the likes of Althusser or Deleuze and other “unwilling” dialecticians he recruits along the way. At the same time, once more taking a jab at structuralist theory – claiming, for example, that one can mistake the structuralist notion of the synchronic for ‘conceptual ideology’ relating to the eternal present of capitalist accumulation – for Jame

  18. Results of cultivation experiment at clean farm (vegetable plant). 1. Clean farm (yasai kojo) ni okeru saibai jikken kekka. 1

    Energy Technology Data Exchange (ETDEWEB)

    Miyaishi, T.; Kawagishi, K.; Matsuzaki, O.; Nakahara, M. (Kyushu Electric Power Co. Ltd., Fukuoka (Japan))


    This paper reports a summary of the facilities in an experimental plant constructed by the Kyushu Electric Power Company in 1988, and a result of experiments on cultivating salad and lettuce. The plant has environmentally controlled cultivating rooms of solar beam combined type and totally artificial light type, each having a floor area of 50 m {sup 2}, disposed with cultivating stages divided into three divisions of seedling culture, growth, and forced culture, nutritious liguid feeding devices of circulation type, and air conditioning equipment. The paper describes results of the tests aimed at realizing an increase in yield and profit, an optimum cultivating system, and economic facilities at the vegetable plant. Included in the tests are that (a) four kinds of salads and five kinds lettuce were selected for cultivation to decide most suitable kinds, based on literature survey and preliminary experiments; (b) varying the environmental conditions for the culture, such as temperature, radiating condition, concentration of the nutritious liquid, and concentration of carbon dioxide, conditions optimum or suitable for the plant growth were selected; (c) the plant was compared with glass green houses with respect to the required cultivating period of time, vitamin C content and color tones of the products; (d) the solar beam combined type room and the totally artificial light rooms were compared with respect to power consumption and heat capacity that passes through the cultivation room walls, and the latter was concluded being superior in economics and stability. 12 refs., 37 figs., 30 tabs.

  19. On noise, traffic and factory vibrations in Akita city; Akitashi ni okeru soon oyobi kotsu kojo shindo ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Nogoshi, M.; Kikuchi, T.; Morino, T.; Sannohe, M. [Akita University, Akita (Japan). College of Education


    Noise and vibration were measured in Akita City. In 1994, noise and traffic-caused vibration were measured along the trunk lines and other roads across the entire Akita City area. In 1995, the effort centered on the Ibarashima manufacturing quarters, the important source of noise and vibration in Akita city. The general-purpose noise meter LA-220S was used to measure noise and the vibration level meter VR-5100 was used to measure vibration. The results of noise measurement carried out at 122 points in Akita City indicated that the noise level was high along Route 7, Route 13, and the southern line belonging to the newly built national highway, marking the highest of approximately 74dB. As compared with the measurement made in 1968, the value was higher by 3-13dB. A roughly similar trend was seen in vibration. The noise level measurement of 1995 accomplished at 100 points in the vicinity of Ibarashima district indicated that the factories were responsible for high levels of noise and vibration. It was found that the levels lowered in proportion to the increase in the distance from the factories. 11 figs., 1 tab.

  20. View on industrial ventilation and its trend in cold region; Kojo kanki no gijutsu doko to kanreichi no tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Kubota, H. [Hokkaido University, Sapporo (Japan); Hanaoka, Y.; Yoshida, Y. [Muroran Institute of Technology, Hokkaido (Japan)


    Environment of working space for production is one of the two typical human environments, along with those of daily life such as homes and offices. Displacement ventilation can be identified as not only a typical system of industrial ventilation but also the oldest system in human history. In this paper, we review a typical characteristic of this system using data on the air distribution obtained in an Ainu people's traditional house 'Chisett', and also introduce a project on Industrial Ventilation which is active in Europe in global cooperation including SHASE. (author)

  1. Energy conservation by efficiency improvement of blowing out air; Air blow koritsu kojo ni yoru sho energy

    Energy Technology Data Exchange (ETDEWEB)

    Izumi, T. [Nissan Motor Co. Ltd., Tokyo (Japan)


    An air blow unit is improved which removes water drops, attached to the product during the cooling process in the plastic gasoline tank manufacturing plant, from the surface for the prevention of defective measurements at the next stage. Appropriate blowing conditions are set according to a designed experiment, and the consumption of compressed air is reduced by 83.7%. The air blow unit is reviewed from three different angles of energy, quality, and noise. For saving energy, pressure is lowered, nozzle outlet is narrowed, and air is caused to diffuse. Since these efforts all lead to a decrease in the blow force, however, a domain has to be found where the water drop removing capability is sustained. High quality is effectively achieved when more air is blown at higher speeds. It is found that the blow force is a component in the horizontal direction on the blown surface, and factors are constructed by hypothesis and tests are conducted. The test results are subjected to a multivariate analysis for shortening the blow time. In consequence, the volume of compressed air consumed for each gasoline tank is reduced by 84% approximately, and the residual water drops by 72.4%. These have resulted in the realization of earplug-free shops. (NEDO)

  2. Future and present condition of waste treatment facilities for foundry; Chuzo kojo haikibutsu shori setsubi no genjo to shorai

    Energy Technology Data Exchange (ETDEWEB)

    Takada, M. [Shinto Kogyo Co. Ltd., Tokyo (Japan)


    The current state of waste disposal facilities in foundries is introduced, and the future way that it should be is investigated from the viewpoint of environmental management of manufacturing plants which is shifting from taking countermeasures for environmental conservation to giving priority to environmental conservation. As the methods for waste disposal, there are a case of reusing it to decrease the quantity of waste as far as possible and a case of converting it into valuable material for reuse by other industries as valuable material. In connection with the facilities for decreasing the quantity of generated waste, outlines are given on the recovery system for spilled sand, classifiers (sieve, air classifier), separators (magnetic separator, shot separator), sand reproducing system, humidifier, and granulators (briquette of turning, granulation of dust). As regards future disposal facilities, investigation must be made on the support facility for production so as to reduce waste generation as far as possible, facility which sort generated waste reliably for easy disposal, facility for material recycling, and facility for realizing zero emission. 5 refs., 5 figs., 5 tabs.

  3. Modeling aerosol impacts on atmospheric visibility in Beijing with RAMS-CMAQ (United States)

    Han, Xiao; Zhang, Meigen; Tao, Jinhua; Wang, Lili; Gao, Jian; Wang, Shulan; Chai, Fahe


    A typical heavy air pollution episode occurred over the North China Plain (NCP) in December 2010. The air quality in Beijing and its surrounding regions worsened during the period December 17 to 22, and local visibility became significantly affected by the high pollution levels. The air quality modeling system RAMS-CMAQ coupled with an aerosol optical property scheme was applied to simulate the trace gases and major aerosol components in the NCP to obtain an in-depth understanding of the relationship between regional low visibility and aerosol particles. The model performance was evaluated using various observation data, such as meteorological factors (temperature, relative humidity, and wind field), gaseous pollutants (SO2, NO2, and O3), PM2.5, PM10, and visibility at several measurement stations. The modeled meteorological field and visibility were in good agreement with observations from December 2010. The modeled mass concentrations of gaseous pollutants and aerosol particles also suitably captured the magnitude and variation features of the observation data, especially during the air pollution episode. The simulated results showed that during this pollution episode, low visibility (lower than 10 km) occurred mainly in Beijing, Tianjin, Hebei, and Shandong. The analysis and sensitivity test indicated that the aerosol particles larger than PM2.5 and the water uptake effect of aerosol optical properties could not significantly influence visibility. Thus, the low visibility was primarily caused by the high mass burden of PM2.5as a result of the local pollutant accumulation and long-range transport. Statistics showed that the visibility variation was closely inversely related to the variation in PM2.5 in most regions in the NCP. Visibility decreased lower than 10 km when the mass concentration of PM2.5 exceeded 75 μg m-3 to 85 μg m-3 in the NCP. Sulfate and nitrate were the two major inorganic aerosol components of PM2.5 that evidently decreased visibility by

  4. Effects of meteorology and secondary particle formation on visibility during heavy haze events in Beijing, China. (United States)

    Zhang, Qiang; Quan, Jiannong; Tie, Xuexi; Li, Xia; Liu, Quan; Gao, Yang; Zhao, Delong


    The causes of haze formation in Beijing, China were analyzed based on a comprehensive measurement, including PBL (planetary boundary layer), aerosol composition and concentrations, and several important meteorological parameters such as visibility, RH (relative humidity), and wind speed/direction. The measurement was conducted in an urban location from Nov. 16, 2012 to Jan. 15, 2013. During the period, the visibility varied from >20 km to less than a kilometer, with a minimum visibility of 667 m, causing 16 haze occurrences. During the haze occurrences, the wind speeds were less than 1m/s, and the concentrations of PM2.5 (particle matter with radius less than 2.5 μm) were often exceeded 200 μg/m(3). The correlation between PM2.5 concentration and visibility under different RH values shows that visibility was exponentially decreased with the increase of PM2.5 concentrations when RH was less than 80%. However, when RH was higher than 80%, the relationship was no longer to follow the exponentially decreasing trend, and the visibility maintained in very low values, even with low PM2.5 concentrations. Under this condition, the hygroscopic growth of particles played important roles, and a large amount of water vapor acted as particle matter (PM) for the reduction of visibility. The variations of meteorological parameters (RH, PBL heights, and WS (wind speed)), chemical species in gas-phase (CO, O3, SO2, and NOx), and gas-phase to particle-phase conversions under different visibility ranges were analyzed. The results show that from high visibility (>20 km) to low visibility (<2 km), the averaged PBL decreased from 1.24 km to 0.53 km; wind speeds reduced from 1m/s to 0.5m/s; and CO increased from 0.5 ppmv to 4.0 ppmv, suggesting that weaker transport/diffusion caused the haze occurrences. This study also found that the formation of SPM (secondary particle matter) was accelerated in the haze events. The conversions between SO2 and SO4 as well as NOx to NO3(-) increased

  5. The System of the Calibration for Visibility Measurement Instrument Under the Atmospheric Aerosol Simulation Environment

    Directory of Open Access Journals (Sweden)

    Shu Zhifeng


    Full Text Available Visibility is one of the most important parameters for meteorological observation and numerical weather prediction (NWP.It is also an important factor in everyday life, mainly for surface and air traffic especially in the Aeronautical Meteorology. The visibility decides the taking off and landing of aircraft. If the airport visibility is lower than requirement for aircraft taking off stipulated by International Civil Aviation Administration, then the aircraft must be parked at the airport. So the accurate measurement of visibility is very important. Nowadays, many devices can be measured the visibility or meteorological optical range (MOR such as Scatterometers, Transmissometers and visibility lidar. But there is not effective way to verify the accuracy of these devices expect the artificial visual method. We have developed a visibility testing system that can be calibration and verification these devices. The system consists of laser transmitter, optical chopper, phase-locking amplifier, the moving optic receiving system, signal detection and data acquisition system, atmospheric aerosol simulation chamber. All of them were placed in the atmosphere aerosol simulation chamber with uniform aerosol concentration. The Continuous wave laser, wavelength 550nm, has been transmitted into the collimation system then the laser beam expanded into 40mm diameter for compressing the laser divergence angle before modulated by optical chopper. The expanding beam transmitting in the atmosphere aerosol cabin received by the optic receiving system moving in the 50m length precision guide with 100mm optical aperture. The data of laser signal has been acquired by phase-locking amplifier every 5 meter range. So the 10 data points can be detected in the 50 meters guide once. The slope of the fitting curve can be obtained by linear fitting these data using the least square method. The laser extinction coefficient was calculated from the slope using the Koschmieder

  6. Recommended metric for tracking visibility progress in the regional haze rule. (United States)

    Gantt, Brett; Beaver, Melinda; Timin, Brian; Lorang, Phil


    For many Class I areas (national parks and wilderness areas with special air quality protections) in the western U.S., wildfire smoke and dust events can have a large impact on visibility. Currently, the Environmental Protection Agency's (EPA) 1999 Regional Haze Rule uses the 20% haziest days to track visibility changes over time even if they are dominated by smoke or dust. Visibility on the 20% haziest days has remained constant or degraded over the last 16 years at some Class I areas despite widespread emission reductions from anthropogenic sources. To better track visibility changes specifically associated with anthropogenic pollution sources rather than natural sources, the EPA as finalized a requirement to track visibility on the 20% most anthropogenically-impaired days rather than the haziest days. To support the implementation of this requirement, the EPA has also proposed (but not finalized) a specific recommended metric for characterizing the anthropogenic and natural portions of the daily extinction budget at each site. This metric selects the 20% most impaired days based on these portions using a "delta deciview" approach to quantify the deciview scale impact of anthropogenic light extinction. Using this metric, sulfate and nitrate make up the majority of the anthropogenic extinction in 2015 on these days, with natural extinction largely made up of organic carbon mass in the eastern U.S. and a combination of organic carbon mass, dust components, and sea-salt in the western U.S. For sites in the western U.S., the seasonality of days selected as the 20% most impaired is different than the seasonality of the 20% haziest days, with many more winter and spring days selected. Applying this new metric to the 2000-2015 period across sites representing Class I areas results in substantial changes in the calculated visibility trend for the Northern Rockies and southwest U.S. Implications Changing the approach for tracking visibility in Regional Haze Rule would

  7. Relationship between Objective and Subjective Atmospheric Visibility and Its Influence on Willingness to Accept or Pay in China.

    Directory of Open Access Journals (Sweden)

    Kangkang Yu

    Full Text Available This study is to distinguish the objective and subjective measures of atmospheric visibility, and investigate the relationship between the two measures as well as the effect on the people's behavioral intentions on air pollution in China. A mixed method was adopted in this study combining both lab experiments to measure objective atmospheric visibility and a questionnaire survey to measure subjective atmospheric visibility. The regression results show that: (a The people's perception of atmospheric visibility is based on objective information about the ambient air (Relative Humidity, PM2.5, Atmospheric Visibility and there are some turning points that could enable people to distinguish good and poor air quality; (b The people's perception of visibility has a significant effect on either their willingness-to-accept (WTA the visibility or on their willingness-to-pay (WTP for improving the air quality;

  8. Shape memory polymers with enhanced visibility for magnetic resonance- and X-ray imaging modalities. (United States)

    Weems, A C; Szafron, J M; Easley, A D; Herting, S; Smolen, J; Maitland, D J


    Currently, monitoring of minimally invasive medical devices is performed using fluoroscopy. The risks associated with fluoroscopy, including increased risk of cancer, make this method especially unsuitable for pediatric device delivery and follow-up procedures. A more suitable method is magnetic resonance (MR) imaging, which makes use of harmless magnetic fields rather than ionizing radiation when imaging the patient; this method is safer for both the patient and the performing technicians. Unfortunately, there is a lack of research available on bulk polymeric materials to enhance MR-visibility for use in medical devices. Here we show the incorporation of both physical and chemical modifying agents for the enhancement of both MR and X-ray visibility. Through the incorporation of these additives, we are able to control shape recovery of the polymer without sacrificing the thermal transition temperatures or the mechanical properties. For long-term implantation, these MR-visible materials do not have altered degradation profiles, and the release of additives is well below significant thresholds for daily dosages of MR-visible compounds. We anticipate our materials to be a starting point for safer, MR-visible medical devices incorporating polymeric components. Shape memory polymers (SMPs) are polymeric materials with unique shape recovery abilities that are being considered for use in biomedical and medical device applications. This paper presents a methodology for the development of MR and X-ray visible SMPs using either a chemically loaded or physical loaded method during polymer synthesis. Such knowledge is imperative for the development and clinical application of SMPs for biomedical devices, specifically for minimally-invasive vascular occlusion treatments, and while there are studies pertaining to the visibility of polymeric particles, little work has been performed on the utility of biomaterials intended for medical devices and the impact of how adding multiple

  9. Fuzzy logic-based analogue forecasting and hybrid modelling of horizontal visibility (United States)

    Tuba, Zoltán; Bottyán, Zsolt


    Forecasting visibility is one of the greatest challenges in aviation meteorology. At the same time, high accuracy visibility forecasts can significantly reduce or make avoidable weather-related risk in aviation as well. To improve forecasting visibility, this research links fuzzy logic-based analogue forecasting and post-processed numerical weather prediction model outputs in hybrid forecast. Performance of analogue forecasting model was improved by the application of Analytic Hierarchy Process. Then, linear combination of the mentioned outputs was applied to create ultra-short term hybrid visibility prediction which gradually shifts the focus from statistical to numerical products taking their advantages during the forecast period. It gives the opportunity to bring closer the numerical visibility forecast to the observations even it is wrong initially. Complete verification of categorical forecasts was carried out; results are available for persistence and terminal aerodrome forecasts (TAF) as well in order to compare. The average value of Heidke Skill Score (HSS) of examined airports of analogue and hybrid forecasts shows very similar results even at the end of forecast period where the rate of analogue prediction in the final hybrid output is 0.1-0.2 only. However, in case of poor visibility (1000-2500 m), hybrid (0.65) and analogue forecasts (0.64) have similar average of HSS in the first 6 h of forecast period, and have better performance than persistence (0.60) or TAF (0.56). Important achievement that hybrid model takes into consideration physics and dynamics of the atmosphere due to the increasing part of the numerical weather prediction. In spite of this, its performance is similar to the most effective visibility forecasting methods and does not follow the poor verification results of clearly numerical outputs.

  10. Recent progress on doped ZnO nanostructures for visible-light photocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Samadi, Morasae; Zirak, Mohammad [Department of Physics, Sharif University of Technology, P.O. Box 11555-9161, Tehran (Iran, Islamic Republic of); Naseri, Amene [Institute for Nanoscience and Nanotechnology, Sharif University of Technology, P.O. Box 11365-8639, Tehran (Iran, Islamic Republic of); Khorashadizade, Elham [Department of Physics, Sharif University of Technology, P.O. Box 11555-9161, Tehran (Iran, Islamic Republic of); Moshfegh, Alireza Z., E-mail: [Department of Physics, Sharif University of Technology, P.O. Box 11555-9161, Tehran (Iran, Islamic Republic of); Institute for Nanoscience and Nanotechnology, Sharif University of Technology, P.O. Box 11365-8639, Tehran (Iran, Islamic Republic of)


    Global environmental pollution and energy supply demand have been regarded as important concerns in recent years. Metal oxide semiconductor photocatalysts is a promising approach to apply environmental remediation as well as fuel generation from water splitting and carbon dioxide reduction. ZnO nanostructures have been shown promising photocatalytic activities due to their non-toxic, inexpensive, and highly efficient nature. However, its wide band gap hinders photo-excitation for practical photocatalytic applications under solar light as an abundant, clean and safe energy source. To overcome this barrier, many strategies have been developed in the last decade to apply ZnO nanostructured photocatalysts under visible light. In this review, we have classified different approaches to activate ZnO as a photocatalyst in visible-light spectrum. Utilization of various nonmetals, transition metals and rare-earth metals for doping in ZnO crystal lattice to create visible-light-responsive doped ZnO photocatalysts is discussed. Generation of localized energy levels within the gap in doped ZnO nanostructures has played an important role in effective photocatalytic reaction under visible-light irradiation. The effect of dopant type, ionic size and its concentration on the crystal structure, electronic property and morphology of doped ZnO with a narrower band gap is reviewed systematically. Finally, a comparative study is performed to evaluate two classes of metals and nonmetals as useful dopants for ZnO nanostructured photocatalysts under visible light. - Highlights: • Metals and nonmetals used as a dopant to shift ZnO band gap toward visible-light. • Modification of electronic structure played a crucial role in doped ZnO activity. • Correlation between dopant's characteristics and ZnO visible activity was reviewed. • Photo-degradation of doped ZnO was studied and compared for different dopants.

  11. GOME-2 Tropospheric Ozone Profile Retrievals from Joint UV/Visible Measurement (United States)

    Liu, X.; Zoogman, P.; Chance, K.; Cai, Z.; Nowlan, C. R.; Huang, G.; Gonzalez Abad, G.


    It has been shown from sensitivity studies that adding visible measurements in the Chappuis ozone band to UV measurements in the Hartley/Huggins ozone bands can significantly enhance retrieval sensitivity to lower tropospheric ozone from backscattered solar radiances due to deeper photon penetration in the visible to the surface than in the ultraviolet. The first NASA EVI (Earth Venture Instrument) TEMPO (Tropospheric Emissions: Monitoring of Pollution) instrument is being developed to measure backscattered solar radiation in two channels ( 290-490 and 540-740 nm) and make atmospheric pollution measurements over North America from the Geostationary orbit. However, this retrieval enhancement has yet to be demonstrated from existing measurements due to the weak ozone absorption in the visible and strong interferences from surface reflectance and aerosols and the requirement of accurate radiometric calibration across different spectral channels. We present GOME-2 retrievals from joint UV/visible measurements using the SAO ozone profile retrieval algorithm, to directly explore the retrieval improvement in lower tropospheric ozone from additional visible measurements. To reduce the retrieval interference from surface reflectance, we add characterization of surface spectral reflectance in the visible based on combining EOFs (Empirical Orthogonal Functions) derived from ASTER and other surface reflectance spectra with MODIS BRDF climatology into the ozone profile algorithm. The impacts of various types of aerosols and surface BRDF on the retrievals will be investigated. In addition, we will also perform empirical radiometric calibration of the GOME-2 data based on radiative transfer simulations. We will evaluate the retrieval improvement of joint UV/visible retrieval over the UV retrieval based on fitting quality and validation against ozonesonde observations.

  12. Long-Term Trend and Seasonal Variability of Horizontal Visibility in Nigerian Troposphere

    Directory of Open Access Journals (Sweden)

    Mukhtar Balarabe


    Full Text Available A study of the long-term variability; trend and characteristics of visibility in four zones of Nigeria was carried out. Visibility and other meteorological data from NOAA-NCDC and aerosol index data over Nigeria during 1984–2013 are analyzed using time series and  simple regression model. There are significant decreasing trends for every region and season during the 30-years period; the fluctuations exhibited nearly similar pattern. The 30-year mean visibilities for the four zones (Sahel; North Central; Southern; and Coastal were 13.8 ± 3.9; 14.3 ± 4.2; 13.6 ± 3.5 and 12.8 ± 3.1 km with decreasing trends at the rates of 0.08; 0.06; 0.02 and 0.02 km/year. In all the zones; visibilities were better in summer while worse in Harmattan (dry season. During summer visibility was best in Sahel and North-central; however; in Harmattan visibility was best in southern and coastal zones. It was best between May and June (17.6; 18.9; 16.6 and 15.1 km with a second peak in September. The 30-year seasonal averages were 16.2 ± 2.1; 16.8 ± 2.4; 15.4 ± 1.8 and 14.0 ± 2.2 km in summer; and 10.2 ± 2.5; 10.9 ± 2.9; 11.0 ± 3.3 and 11.4 ± 3.0 km in Harmattan for the respective zones. Sahel and North Central had the worse visibility reduction during Harmattan compared with Southern and coastal areas. An analysis based on simple regression equation reveals a strong and negative relationship between visibility on one hand; AI; and AOD on the other hand. The analysis also discusses the variability regarding the frequency of occurrence of a dust storm; dust haze; and good visibility over the period of study.

  13. Environmental remediation and superhydrophilicity of ultrafine antibacterial tungsten oxide-based nanofibers under visible light source

    Energy Technology Data Exchange (ETDEWEB)

    Srisitthiratkul, Chutima; Yaipimai, Wittaya [Nano Functional Textile Laboratory, National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Rd., Klong 1, Klong Luang, Pathumthani 12120 (Thailand); Intasanta, Varol, E-mail: [Nano Functional Textile Laboratory, National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Rd., Klong 1, Klong Luang, Pathumthani 12120 (Thailand)


    Graphical abstract: Nanosilver-decorated WO{sub 3} photocatalytic nanofibers are antibacterial and superhydrophilic under a visible light source. Highlights: Black-Right-Pointing-Pointer Deposition of nanosilver onto electrospun WO{sub 3} nanofibers' surface was done exploiting visible or UV light driven photoreduction of silver ion. Black-Right-Pointing-Pointer Nanofibers showed antibacterial characteristics. Black-Right-Pointing-Pointer Nanofibers degraded a model toxin effectively. Black-Right-Pointing-Pointer Nanofibers showed superhydrophilicity under a visible light source. - Abstract: Fabrication of nanosilver-decorated WO{sub 3} nanofibers was successfully performed. First, deposition of nanosilver onto electrospun WO{sub 3} nanofibers' surface was done via photoreduction of silver ion under visible or UV light. The resulting hybrid nanofibers not only revealed antibacterial characteristics but also maintained their photocatalytic performance towards methylene blue decomposition. Unexpectedly, the nanofibrous layers prepared from these nanofibers showed superhydrophilicity under a visible light source. The nanofibers might be advantageous in environmental and hygienic nanofiltration under natural light sources, where the self-cleaning characteristics could be valuable in maintenance processes.

  14. Inactivation of bacterial biofilms using visible-light-activated unmodified ZnO nanorods (United States)

    Aponiene, Kristina; Serevičius, Tomas; Luksiene, Zivile; Juršėnas, Saulius


    Various zinc oxide (ZnO) nanostructures are widely used for photocatalytic antibacterial applications. Since ZnO possesses a wide bandgap, it is believed that only UV light may efficiently assist bacterial inactivation, and diverse crystal lattice modifications should be applied in order to narrow the bandgap for efficient visible-light absorption. In this work we show that even unmodified ZnO nanorods grown by an aqueous chemical growth technique are found to possess intrinsic defects that can be activated by visible light (λ = 405 nm) and successfully applied for total inactivation of various highly resistant bacterial biofilms rather than more sensitive planktonic bacteria. Time-resolved fluorescence analysis has revealed that visible-light excitation creates long-lived charge carriers (τ > 1 μs), which might be crucial for destructive biochemical reactions achieving significant bacterial biofilm inactivation. ZnO nanorods covered with bacterial biofilms of Enterococcus faecalis MSCL 302 after illumination by visible light (λ = 405 nm) were inactivated by 2 log, and Listeria monocytogenes ATCL3C 7644 and Escherichia coli O157:H7 biofilms by 4 log. Heterogenic waste-water microbial biofilms, consisting of a mixed population of mesophilic bacteria after illumination with visible light were also completely destroyed.

  15. Fusion of Visible and Thermal Descriptors Using Genetic Algorithms for Face Recognition Systems

    Directory of Open Access Journals (Sweden)

    Gabriel Hermosilla


    Full Text Available The aim of this article is to present a new face recognition system based on the fusion of visible and thermal features obtained from the most current local matching descriptors by maximizing face recognition rates through the use of genetic algorithms. The article considers a comparison of the performance of the proposed fusion methodology against five current face recognition methods and classic fusion techniques used commonly in the literature. These were selected by considering their performance in face recognition. The five local matching methods and the proposed fusion methodology are evaluated using the standard visible/thermal database, the Equinox database, along with a new database, the PUCV-VTF, designed for visible-thermal studies in face recognition and described for the first time in this work. The latter is created considering visible and thermal image sensors with different real-world conditions, such as variations in illumination, facial expression, pose, occlusion, etc. The main conclusions of this article are that two variants of the proposed fusion methodology surpass current face recognition methods and the classic fusion techniques reported in the literature, attaining recognition rates of over 97% and 99% for the Equinox and PUCV-VTF databases, respectively. The fusion methodology is very robust to illumination and expression changes, as it combines thermal and visible information efficiently by using genetic algorithms, thus allowing it to choose optimal face areas where one spectrum is more representative than the other.

  16. Basic Study on Visibility and Water Equivalency of a New Colorless Transparent Bolus for Electron Radiotherapy. (United States)

    Maruyama, Daiki; Yamazaki, Shinichi; Honda, Emi; Suzuki, Eiji; Hommatsu, Kouji; Oshiba, Ryo; Sato, Noboru


    Boluses used in electron radiotherapy need to have radiation field visibility and water equivalence. In this report, we have examined field visibility and water equivalence of a new colorless transparent bolus. We examined field visibility, water equivalence, and dose profile. Field visibility was evaluated by comparison to conventional bolus. Water equivalence was investigated by a measured fluence scaling factor. The dose profile was measured by using radiochromic film with the bolus and an ionization chamber in water. We confirmed that the irradiation field could clearly be seen through the transparent colorless bolus. The bolus did not cast a field edge as compared with the conventional bolus. The fluence scaling factor was less than 0.8% as compared to water. We confirmed that the colorless transparent bolus was treated as a water equivalent material. The percentage depth dose (PDD) measured by using radiochromic film with the bolus matched the PDD measured with an ionization chamber in water. R50 was less than 1 mm as compared to PDD measured with an ionization chamber. It was confirmed that the colorless transparent bolus can use to set up patient without losing visibility on flat ground planes. The fluence scaling factor and dose profile measured by using the bolus matched the results measured in water. Therefore, the new colorless transparent bolus has feasibility to improve patient setup efficiency and can improve calculation accuracy by using the fluence scaling factor.

  17. Superpixel segmentation and pigment identification of colored relics based on visible spectral image. (United States)

    Li, Junfeng; Wan, Xiaoxia


    To enrich the contents of digital archive and to guide the copy and restoration of colored relics, non-invasive methods for extraction of painting boundary and identification of pigment composition are proposed in this study based on the visible spectral images of colored relics. Superpixel concept is applied for the first time to the field of oversegmentation of visible spectral images and implemented on the visible spectral images of colored relics to extract their painting boundary. Since different pigments are characterized by their own spectrum and the same kind of pigment has the similar geometric profile in spectrum, an automatic identification method is established by comparing the proximity between the geometric profiles of the unknown spectrum from each superpixel and the pre-known spectrum from a deliberately prepared database. The methods are validated using the visible spectral images of the ancient wall paintings in Mogao Grottoes. By the way, the visible spectral images are captured by a multispectral imaging system consisting of two broadband filters and a RGB camera with high spatial resolution. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Preparation of TiO2-Fullerene Composites and Their Photocatalytic Activity under Visible Light

    Directory of Open Access Journals (Sweden)

    Ken-ichi Katsumata


    Full Text Available The development of visible light-sensitive photocatalytic materials is being investigated. In this study, the anatase and rutile-C60 composites were prepared by solution process. The characterization of the samples was conducted by using XRD, UV-vis, FT-IR, Raman, and TEM. The photocatalytic activity of the samples was evaluated by the decolorization of the methylene blue. From the results of the Raman, FT-IR, and XRD, the existence of the C60 was confirmed in the samples. The C60 was modified on the anatase or rutile particle as a cluster. The C60 didn't have the photocatalytic activity under UV and visible light. The anatase and rutile-C60 composites exhibited lower photocatalytic activity than the anatase and rutile under UV light. The anatase-C60 exhibited also lower activity than the anatase under visible light. On the other hand, the rutile-C60 exhibited higher activity than the rutile under visible light. It is considered that the photogenerated electrons can transfer from the C60 to the rutile under visible light irradiation.

  19. Exploring the feasibility of iris recognition for visible spectrum iris images obtained using smartphone camera (United States)

    Trokielewicz, Mateusz; Bartuzi, Ewelina; Michowska, Katarzyna; Andrzejewska, Antonina; Selegrat, Monika


    In the age of modern, hyperconnected society that increasingly relies on mobile devices and solutions, implementing a reliable and accurate biometric system employing iris recognition presents new challenges. Typical biometric systems employing iris analysis require expensive and complicated hardware. We therefore explore an alternative way using visible spectrum iris imaging. This paper aims at answering several questions related to applying iris biometrics for images obtained in the visible spectrum using smartphone camera. Can irides be successfully and effortlessly imaged using a smartphone's built-in camera? Can existing iris recognition methods perform well when presented with such images? The main advantage of using near-infrared (NIR) illumination in dedicated iris recognition cameras is good performance almost independent of the iris color and pigmentation. Are the images obtained from smartphone's camera of sufficient quality even for the dark irides? We present experiments incorporating simple image preprocessing to find the best visibility of iris texture, followed by a performance study to assess whether iris recognition methods originally aimed at NIR iris images perform well with visible light images. To our best knowledge this is the first comprehensive analysis of iris recognition performance using a database of high-quality images collected in visible light using the smartphones flashlight together with the application of commercial off-the-shelf (COTS) iris recognition methods.

  20. Fusion of Visible and Thermal Descriptors Using Genetic Algorithms for Face Recognition Systems. (United States)

    Hermosilla, Gabriel; Gallardo, Francisco; Farias, Gonzalo; San Martin, Cesar


    The aim of this article is to present a new face recognition system based on the fusion of visible and thermal features obtained from the most current local matching descriptors by maximizing face recognition rates through the use of genetic algorithms. The article considers a comparison of the performance of the proposed fusion methodology against five current face recognition methods and classic fusion techniques used commonly in the literature. These were selected by considering their performance in face recognition. The five local matching methods and the proposed fusion methodology are evaluated using the standard visible/thermal database, the Equinox database, along with a new database, the PUCV-VTF, designed for visible-thermal studies in face recognition and described for the first time in this work. The latter is created considering visible and thermal image sensors with different real-world conditions, such as variations in illumination, facial expression, pose, occlusion, etc. The main conclusions of this article are that two variants of the proposed fusion methodology surpass current face recognition methods and the classic fusion techniques reported in the literature, attaining recognition rates of over 97% and 99% for the Equinox and PUCV-VTF databases, respectively. The fusion methodology is very robust to illumination and expression changes, as it combines thermal and visible information efficiently by using genetic algorithms, thus allowing it to choose optimal face areas where one spectrum is more representative than the other.