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1

Floating Light-Activated Micro Electrical Stimulators Tested in the Rat Spinal Cord  

PubMed Central

Microelectrodes of neural stimulation utilize fine wires for electrical connections to driving electronics. Breakage of these wires and the neural tissue response due to their tethering forces are major problems encountered with long term implantation of microelectrodes. The lifetime of an implant for neural stimulation can be substantially improved if the wire interconnects are eliminated. Thus, we proposed a floating light-activated micro electrical stimulator (FLAMES) for wireless neural stimulation. In this paradigm, a laser beam at near infrared (NIR) wavelengths will be used as a means of energy transfer to the device. In this study, microstimulators of various sizes were fabricated, with two cascaded GaAs p-i-n photodiodes, and tested in the rat spinal cord. A train of NIR pulses (0.2 ms, 50 Hz) was sent through the tissue to wirelessly activate the devices and generate the stimulus current. The forces elicited by intraspinal stimulation were measured from the ipsilateral forelimb with a force transducer. The largest forces were around 1.08N, a significant level of force for the rat forelimb motor function. These in vivo tests suggest that the FLAMES can be used for intraspinal microstimulation even for the deepest implant locations in the rat spinal cord. The power required to generate a threshold arm movement was investigated as the laser source was moved away from the microstimulator. The results indicate that the photon density does not decrease substantially for horizontal displacements of the source that are in the same order as the beam radius. This gives confidence that the stimulation threshold may not be very sensitive to small displacement of the spinal cord relative to the spine-mounted optical power source. PMID:21914931

Abdo, Ammar; Sahin, Mesut; Freedman, David S.; Cevik, Elif; Spuhler, Philipp S.; Unlu, M. Selim

2011-01-01

2

Floating light-activated microelectrical stimulators tested in the rat spinal cord  

NASA Astrophysics Data System (ADS)

Microelectrodes of neural stimulation utilize fine wires for electrical connections to driving electronics. Breakage of these wires and the neural tissue response due to their tethering forces are major problems encountered with long-term implantation of microelectrodes. The lifetime of an implant for neural stimulation can be substantially improved if the wire interconnects are eliminated. Thus, we proposed a floating light-activated microelectrical stimulator (FLAMES) for wireless neural stimulation. In this paradigm, a laser beam at near infrared (NIR) wavelengths will be used as a means of energy transfer to the device. In this study, microstimulators of various sizes were fabricated, with two cascaded GaAs p-i-n photodiodes, and tested in the rat spinal cord. A train of NIR pulses (0.2 ms, 50 Hz) was sent through the tissue to wirelessly activate the devices and generate the stimulus current. The forces elicited by intraspinal stimulation were measured from the ipsilateral forelimb with a force transducer. The largest forces were around 1.08 N, a significant level of force for the rat forelimb motor function. These in vivo tests suggest that the FLAMES can be used for intraspinal microstimulation even for the deepest implant locations in the rat spinal cord. The power required to generate a threshold arm movement was investigated as the laser source was moved away from the microstimulator. The results indicate that the photon density does not decrease substantially for horizontal displacements of the source that are in the same order as the beam radius. This gives confidence that the stimulation threshold may not be very sensitive to small displacement of the spinal cord relative to the spine-mounted optical power source.

Abdo, Ammar; Sahin, Mesut; Freedman, David S.; Cevik, Elif; Spuhler, Philipp S.; Unlu, M. Selim

2011-10-01

3

Floating light-activated microelectrical stimulators tested in the rat spinal cord This article has been downloaded from IOPscience. Please scroll down to see the full text article.  

E-print Network

Floating light-activated microelectrical stimulators tested in the rat spinal cord This article has in the rat spinal cord Ammar Abdo1, Mesut Sahin1,4, David S Freedman2, Elif Cevik3, Philipp S Spuhler3 and M spinal cord. A train of NIR pulses (0.2 ms, 50 Hz) was sent through the tissue to wirelessly activate

4

Floating point verification in HOL Light: the exponential function  

E-print Network

Floating point verification in HOL Light: the exponential function, operations for computing the common transcendental functions in floating point arithmetic seem good floating point arithmetic. We confirm (indeed strengthen) the main result of a previously published

Haddadi, Hamed

5

Floating point verification in HOL Light: the exponential function  

E-print Network

Floating point verification in HOL Light: the exponential function John Harrison \\Lambda University in floating point arithmetic seem good targets for formal verification using a me­ chanical theorem prover. We­checked verification of an algorithm for computing the exponential function in IEEE­754 standard binary floating point

Haddadi, Hamed

6

Study on activity float parallel properties in Activity-on-Arc Network  

Microsoft Academic Search

The study of activity float properties is the basis of scientific project planning and controlling. Aiming at the problem that an arbitrary activity having consumed float will affect float of parallel activities and both preceding and succeeding activities which aren't activities of float characteristic transfer chains, i.e., activity float parallel properties, by the analysis of three forms and the affection

Zhixiong Su; Jianxun Qi

2010-01-01

7

Float analysis of non?serial repetitive activities  

Microsoft Academic Search

Floats and critical path(s) are important issues in construction management practice. In critical path method, activities not on the critical path(s) must have float. Float measures the amount of time an activity can be delayed before it becomes critical. Consecutive repetitive activities have production rates, which may vary considerably from one activity to another. This creates a different situation (from

Mohammad A. Ammar

2003-01-01

8

Regression Equations for Determining Light Transmission in Tinted Float Glass  

Microsoft Academic Search

Using methods of mathematical statistics, a model is developed in the form of a linear regression equation, which adequately describes light transmission variations in bulk-tinted float glass in the visible and IR spectra, depending on the variation of the main technological parameters.

N. N. Shcherbakova; V. I. Kondrashov; I. A. Kupriyanova; V. A. Gorokhovskii

2001-01-01

9

Using light-permeable grating to mitigate impacts of residential floats on eelgrass Zostera marina L. in Puget Sound, Washington  

Microsoft Academic Search

This study evaluated whether light-permeable deck grating could mitigate impacts of residential mooring floats constructed over eelgrass (Zostera marina L.) in Puget Sound, Washington. Eelgrass shoot densities in undisturbed control areas and underneath and adjacent to 11 residential floats (1650% of each float was grated) were monitored prior to float installation and annually for 3 years following installation. Using linear

Kurt L. Fresh; Tina Wyllie-Echeverria; Sandy Wyllie-Echeverria; Brian W. Williams

2006-01-01

10

CMOS Active-Pixel Image Sensor With Simple Floating Gates  

NASA Technical Reports Server (NTRS)

Experimental complementary metal-oxide/semiconductor (CMOS) active-pixel image sensor integrated circuit features simple floating-gate structure, with metal-oxide/semiconductor field-effect transistor (MOSFET) as active circuit element in each pixel. Provides flexibility of readout modes, no kTC noise, and relatively simple structure suitable for high-density arrays. Features desirable for "smart sensor" applications.

Fossum, Eric R.; Nakamura, Junichi; Kemeny, Sabrina E.

1996-01-01

11

New concepts for activity float in resource-constrained project management  

Microsoft Academic Search

The concepts of float and critical path are central to analyzing activity networks in project management. In resource-constrained projects, schedule multiplicity makes it difficult to calculate float and identify critical activities accurately. In this work, new concepts of float and critical activity are developed to ascertain critical activities more precisely without reference to activity start and end times in specific

Andrew Lim; Hong Ma; Brian Rodrigues; Sun Teck Tan; Fei Xiao

2011-01-01

12

Sensitivity Analysis on Single Activity to Network Float in CPM Network Planning  

Microsoft Academic Search

\\u000a In CPM network planning, one activity consumes float may affect other activities floats, so that making the gross of network\\u000a floats change. The objective of sensitivity analysis on single activity to network floats is to measure the effect. Aiming\\u000a at the matter, firstly, conception of eigenvalue parameter and method of computing the parameter are given; secondly, sensitivity\\u000a of single activity

Zhixiong Su; Jianxun Qi

2010-01-01

13

Correlative light and electron microscopy for a free-floating spindle in Xenopus laevis egg extracts.  

PubMed

Cryoimmobilization is an optimal method of preserving sample ultrastructure in electron microscopy studies. However, cryoimmobilization is limited to thin samples and this limitation may necessitate the isolation of the structure of interest. For cellular structures that are found in low number, or only during certain phases of the cell cycle, an added benefit of isolation is the possibility to concentrate the structures. We developed a method to perform correlative light and electron microscopy on infrequent isolated subcellular structures. In this chapter, we will describe our protocol that uses a combination of existing techniques and new solutions for the isolation, identification, cryoimmobilization, targeted ultramicrotomy, and imaging of the free-floating meiotic spindles assembled in Xenopus laevis egg extract. PMID:25287839

Tranfield, Erin M; Heiligenstein, Xavier; Peristere, Ina; Antony, Claude

2014-01-01

14

Floating electrode optoelectronic tweezers: Light-driven dielectrophoretic droplet manipulation in electrically insulating oil medium  

PubMed Central

We report an optical actuation mechanism, floating electrode optoelectronic tweezers (FEOET). FEOET enables light-driven transport of aqueous droplets immersed in electrically insulating oil on a featureless photoconductive glass layer with direct optical images. We demonstrate that a 681 ?m de-ionized water droplet immersed in corn oil medium is actuated by a 3.21 ?W laser beam with an average intensity as low as 4.08 ?W?mm2 at a maximum speed of 85.1 ?m?s on a FEOET device. FEOET provides a promising platform for massively parallel droplet manipulation with optical images on low cost, silicon-coated glass. The FEOET device structure, fabrication, working principle, numerical simulations, and operational results are presented in this letter. PMID:19479046

Park, Sungyong; Pan, Chenlu; Wu, Ting-Hsiang; Kloss, Christoph; Kalim, Sheraz; Callahan, Caitlin E.; Teitell, Michael; Chiou, Eric P.Y.

2008-01-01

15

"JCE" Classroom Activity #108. Using Archimedes' Principle to Explain Floating and Sinking Cans  

ERIC Educational Resources Information Center

In this activity, students (working alone or in groups) measure the mass of several soda cans (diet and regular soda) along with the mass of water that each can displaces. The students are then asked to compare these two mass values for the sinking cans and for the floating cans. The purpose of this activity is for students to determine that the

Sanger, Michael J.

2011-01-01

16

Lighting Classroom Activity  

NSDL National Science Digital Library

In this lesson from Math Machines, students will design and test an automatic control system for lighting a room. They will examine the system's energy efficiency, response time and effectiveness. Students will be led through the activity step by step via the provided handout. A participant handout (including worksheets), facilitator notes, construction guide, sample data and annotated program listing are made available for download. Links to calculator programs are also included.

Thomas, Fred

17

Floating Butterfly  

NSDL National Science Digital Library

In this activity, learners create a cool floating animal using the science of magnetism. Learners discover what happens when a piece of magnetic metal enters a magnet's field. Learners also examine magnetic poles. Note, a drill is required for this activity, and is not included in the cost of materials.

2014-09-12

18

Floating Boats  

ERIC Educational Resources Information Center

The purpose of this article is to describe a simple laboratory activity in which students collect a series of measurements and then use graphical analysis to determine the nature of the relationship between an object's mass and the volume of water it displaces. In this activity, students explore the relationships between the mass of a floating

Waugh, Michael

2007-01-01

19

Ice Floats  

NSDL National Science Digital Library

This is a lesson about displacement, buoyancy, and density. Learners will understand why ice floats. Includes background information, teacher notes, assessment criteria, and related resources; activities are differentiated for Pre-K-grade 2 and grades 3-5. This is lesson 4 of the unit Exploring Ice in the Solar System.

20

"Does it Float?" An inquiry-based activity investigating buoyancy  

NSDL National Science Digital Library

This is an inquiry-based activity in which students will need to work together as a class to solve the following problem: they must construct a "boat" entirely out of modeling clay that is capable of supporting 150 grams of cargo without sinking.

Sean Sletten

21

The activity of sodium oxide in molten float glass by EMF measurements  

Microsoft Academic Search

The Na2O activity in the molten float glass composed of 13.2m\\/o Na2O, 70.2m\\/o SiO2, 10.0m\\/o CaO, 5.9m\\/o MgO, etc. was determined in the temperature range from 1260 to 1380K by means of galvanic cells using Na??-alumina as solid electrolyte. The Na2O activity, aNa2O, accompanying the reaction Na2O (dissolved in Na2OWO3 melt)=Na2O (dissolved in molten glass) was found to be given

Woo-Sung Kim; Do-Hyung Cho; Sung-Ki Lim

2004-01-01

22

A poly-Si thin film transistor fabricated by new excimer laser recrystallization employing floating active structure  

Microsoft Academic Search

We fabricated a high-performance polycrystalline silicon (poly-Si) thin film transistor (TFT) by new excimer laser annealing (ELA) method employing floating active structure. The new simple ELA method produces large lateral grains exceeding 4 ?m. A novel poly-Si TFT that exhibits very high mobility (?FE=331 cm2\\/Vs) and low leakage current has been successfully fabricated by single laser irradiation on selectively floating

In-Hyuk Song; Cheon-Hong Kim; Woo-Jin Nam; Min-Koo Han

2002-01-01

23

Floating Boats  

NSDL National Science Digital Library

The purpose of this article is to describe a simple laboratory activity in which students collect a series of measurements and then use graphical analysis to determine the nature of the relationship between an object's mass and the volume of water it displaces. In this activity, students explore the relationships between the mass of a floating object, the amount the object sinks in the water, and its displaced volume. The data will reveal a unique relationship between an object's metrically measured mass and volume and its buoyancy in water. This can lead to an elaboration of the density concept and provide a concrete model for systems involving other forms of balance and equilibrium.

Michael Waugh

2007-07-01

24

Investigation of Electrical Activity of Dislocation and Grain Boundary in Polycrystalline Float Zone Silicon  

SciTech Connect

In this paper, the charge carrier recombination behavior of grain boundaries(GBs) and intra-grain dislocations in high purity polycrystalline float-zone(FZ) silicon were studied by electron beam induced current (EBIC), laser microwave photoconductance decay (PCD) and preferential etching/Normaski optical microscopy. It was found that the lifetime on a single wafer increased from~10?s to 100?s as the average grain size varied from 100?m to several millimeters, while both dislocations near the surface and grain boundaries produce a strong EBIC contrast at room temperature. Since the near surface dislocation EBIC contrast disappears with increasing space charge probe depth, i.e., diode bias, the electrical activity is not likely to be intrinsic to the grown crystal, but due to contamination introduced during chem-mechanical polishing. However, the 'clean' grain boundaries continue to act as strong recombination centers.

Lu, J.; Rozgonyi, G.; Kordas, L.; Ciszek, T.

2003-05-01

25

Visible Light Communications: Recent Activities in Japan  

E-print Network

) continuously takes images of a scene with an LED light and a Visible Light Communications: Recent Activities in Japan Shinichiro Haruyama, Professor Lighting ERC Industry - Academia Day at BU Photonics Center, Boston University February 8, 2011 Shinichiro

Lü, James Jian-Qiang

26

Does It Sink or Float?  

ERIC Educational Resources Information Center

This activity is designed to teach prekindergarten to second grade students about the concept of sink or float through an inquiry activity. Students will use familiar objects to predict and test the properties of sink and float. Background information is offered to teachers to assist them with this activity. This lesson begins with an engaging

McDonald, Judith Richards

2012-01-01

27

Floating numerals and floating quantifiers  

Microsoft Academic Search

This paper investigates the basic licensing conditions of the floating quantifier, e.g. all in The boys all took a card. It proposes a new analysis in which the quantificational operation of the floating quantifier is distinct from that of the quantifier local to a DP, e.g. all in All boys took a card, in the sense that the former takes

Mana Kobuchi-Philip

2007-01-01

28

Bright light activates a trigeminal nociceptive pathway.  

PubMed

Bright light can cause ocular discomfort and/or pain; however, the mechanism linking luminance to trigeminal nerve activity is not known. In this study we identify a novel reflex circuit necessary for bright light to excite nociceptive neurons in superficial laminae of trigeminal subnucleus caudalis (Vc/C1). Vc/C1 neurons encoded light intensity and displayed a long delay (>10s) for activation. Microinjection of lidocaine into the eye or trigeminal root ganglion (TRG) inhibited light responses completely, whereas topical application onto the ocular surface had no effect. These findings indicated that light-evoked Vc/C1 activity was mediated by an intraocular mechanism and transmission through the TRG. Disrupting local vasomotor activity by intraocular microinjection of the vasoconstrictive agents, norepinephrine or phenylephrine, blocked light-evoked neural activity, whereas ocular surface or intra-TRG microinjection of norepinephrine had no effect. Pupillary muscle activity did not contribute since light-evoked responses were not altered by atropine. Microinjection of lidocaine into the superior salivatory nucleus diminished light-evoked Vc/C1 activity and lacrimation suggesting that increased parasympathetic outflow was critical for light-evoked responses. The reflex circuit also required input through accessory visual pathways since both Vc/C1 activity and lacrimation were prevented by local blockade of the olivary pretectal nucleus. These findings support the hypothesis that bright light activates trigeminal nerve activity through an intraocular mechanism driven by a luminance-responsive circuit and increased parasympathetic outflow to the eye. PMID:20206444

Okamoto, Keiichiro; Tashiro, Akimasa; Chang, Zheng; Bereiter, David A

2010-05-01

29

A poly-Si TFT fabricated by excimer laser recrystallization on floating active structure  

Microsoft Academic Search

This letter reports a. new excimer laser annealing (ELA) method to produce large polycrystalline silicon (poly-Si) lateral grains exceeding 4 ?m. A selectively floating amorphous silicon (a-Si) flint with a 50 nm-thick air-gap was irradiated by a single-pulse XeCl excimer laser and uniform lateral grains were grown due to the lateral thermal gradient caused by the low thermal conductivity of

Cheon-Hong Kim; In-Hyuk Song; Woo-Jin Nam; Min-Koo Han

2002-01-01

30

Bright light activates a trigeminal nociceptive pathway  

Microsoft Academic Search

Bright light can cause ocular discomfort and\\/or pain; however, the mechanism linking luminance to trigeminal nerve activity is not known. In this study we identify a novel reflex circuit necessary for bright light to excite nociceptive neurons in superficial laminae of trigeminal subnucleus caudalis (Vc\\/C1). Vc\\/C1 neurons encoded light intensity and displayed a long delay (>10s) for activation. Microinjection of

Keiichiro Okamoto; Akimasa Tashiro; Zheng Chang; David A. Bereiter

2010-01-01

31

Floating Paper Clip  

NSDL National Science Digital Library

In this activity, challenge learners to float a paper clip in a cup of water. Learners discover that a paper clip will sink in a cup of water, except when it is placed on a piece of paper towel. Use this activity to demonstrate the principles of surface tension, adhesion/cohesion, and gravity.

WGBH Boston

2002-01-01

32

Root Beer Float  

NSDL National Science Digital Library

In this quick activity/demonstration about density, learners examine what happens when two cans of root beer--one diet and one regular--are placed in a large container of water. Do they sink or float? Use this activity to introduce learners to the importance of density as well as the nutritional content of soft drinks.

Colorado State University

2009-01-01

33

Float My Boat  

NSDL National Science Digital Library

In this activity, learners use tinfoil to build and test their own boats - which designs will float, and which will sink? Learners must adjust many variables in their boat design to maximize stability and flotation, in order for the boat to support a heavy load of pennies. This activity is great used with lessons on engineering or design.

2013-12-05

34

Floating Head Cup  

NSDL National Science Digital Library

In this activity, learners watch a figure "magically" float up through the air. Learners use 2 straws, a cup, rubber band, pipe cleaner, and piece of buoyant material to make a simple model of novel Chinese art pieces, which are typically made out of ceramics. Use this activity to demonstrate the relationship between density and buoyancy.

Watsonville Environmental Science Workshop

2011-01-01

35

Lighting Class Activity: Web Search  

NSDL National Science Digital Library

This class exercise asks students to use the web to search for lighting resources. Students are asked to find resources that focus on both traditional and green lighting technologies. They will then write a one page report on what they found and the best features of their favorite sites. This assignment would be most useful in a high school or lower college level residential design course. This document may be downloaded in Microsoft Word Doc file format.

Wolf, Arlynne

36

Artificial light and nocturnal activity in gammarids  

PubMed Central

Artificial light is gaining attention as a potential stressor to aquatic ecosystems. Artificial lights located near streams increase light levels experienced by stream invertebrates and we hypothesized light would depress night drift rates. We also hypothesized that the effect of light on drift rates would decrease over time as the invertebrates acclimated to the new light level over the course of one months exposure. These hypotheses were tested by placing Gammarus spp. in eight, 75 m 1 m artificial flumes. One flume was exposed to strong (416 lx) artificial light at night. This strong light created a gradient between 4.19 and 0.04 lx over the neighboring six artificial flumes, while a control flume was completely covered with black plastic at night. Night-time light measurements taken in the Berlin area confirm that half the flumes were at light levels experienced by urban aquatic invertebrates. Surprisingly, no light treatment affected gammarid drift rates. In contrast, physical activity measurements of in situ individually caged G. roeseli showed they increased short-term activity levels in nights of complete darkness and decreased activity levels in brightly lit flumes. Both nocturnal and diurnal drift increased, and day drift rates were unexpectadly higher than nocturnal drift. PMID:24688857

Hlker, Franz; Heller, Stefan; Berghahn, Rdiger

2014-01-01

37

Overview o floating point  

E-print Network

Overview o floating point - SPARC double floats - SPARC quad floats - Intel coprocessor - Intel formats - Intel operations o processor; SPARC 64-bit Floating Point Representation o 1 bit for the sign s (0

Biagioni, Edoardo S.

38

Advanced Light Source Activity Report 2000  

SciTech Connect

This is an annual report, detailing activities at the Advanced Light Source for the year 2000. It includes highlights of scientific research by users of the facility as well as information about the development of the facility itself.

Greiner, A.; Moxon, L.; Robinson, A.; Tamura, L.

2001-04-01

39

Float or Sink?  

NSDL National Science Digital Library

In this water activity, learners test which objects float and which sink. Learners discover that objects behave differently in water. Learners are also introduced to the idea of "predicting" and record their predictions and observations on a chart. This activity is part of the curriculum Explore Water, related to Peep and the Big Wide World, a preschool science series on public television. The activity starts on page 41 of the PDF.

WGBH Educational Foundation

2005-01-01

40

On floats and float tests  

NASA Technical Reports Server (NTRS)

The principal source of information on float resistance is the model test. In view of the insuperable difficulties opposing any attempt at theoretical treatment of the resistance problem, particularly at attitudes which tend toward satisfactory take-off, such as the transitory stage to planing, the towing test is and will remain the primary method for some time.

Seewald, Friedrich

1931-01-01

41

Light-Activated Content Release from Liposomes  

PubMed Central

Successful integration of diagnostic and therapeutic actions at the level of individual cells requires new materials that combine biological compatibility with functional versatility. This review focuses on the development of liposome-based functional materials, where payload release is activated by light. Methods of sensitizing liposomes to light have progressed from the use of organic molecular moieties to the use of metallic plasmon resonant structures. This development has facilitated application of near infrared light for activation, which is preferred for its deep penetration and low phototoxicity in biological tissues. Presented mechanisms of light-activated liposomal content release enable precise in vitro manipulation of minute amounts of reagents, but their use in clinical diagnostic and therapeutic applications will require demonstration of safety and efficacy. PMID:23139729

Leung, Sarah J.; Romanowski, Marek

2012-01-01

42

SERS-active silver nanoparticle aggregates produced in high-iron float glass by ion exchange process  

NASA Astrophysics Data System (ADS)

Silver nanoparticles were produced in iron containing float glasses by silver-sodium ion exchange and post-annealing. In particular, the effect of the concentration and the oxidation state of iron in the host glass on the nanoparticle formation was studied. After the nanoparticle fabrication process, the samples were characterized by optical absorption measurements. The samples were etched to expose nanoparticle aggregates on the surface, which were studied by optical microscopy and scanning electron microscopy. The SERS-activity of these glass samples was demonstrated and compared using a dye molecule Rhodamine 6G (R6G) as an analyte. The importance of the iron oxidation level for reduction process is discussed. The glass with high concentration of Fe 2+ ions was found to be superior in SERS applications of silver nanoparticles. The optimal surface features in terms of SERS enhancement are also discussed.

Karvonen, L.; Chen, Y.; Syntjoki, A.; Taiviola, K.; Tervonen, A.; Honkanen, S.

2011-11-01

43

FloatingPoint FloatingPoint  

E-print Network

Floating­Point for CS 267 February 8, 1996 11:50 am Slide 1 What can you learn about Floating for CS 267, ( Profs. J.W . Demmel of UCB & A. Edelman of MIT ) 8 Feb. 1996 #12; Floating­Point for CS 267 ... ) Integers Fixed­Point Floating­Point #12; Floating­Point for CS 267 February 8, 1996 11:50 am Slide 3

California at Berkeley, University of

44

Floating layer recovery apparatus  

Microsoft Academic Search

This patent describes an apparatus for recovery of a layer of a first underground liquid floating on a second underground liquid in a well. It comprises: first float means disposed in the well in the first liquid, the float means having an effective buoyancy such that it floats in the first liquid; second float means disposed in the well in

K. Newcomer; S. Richter

1991-01-01

45

Floating point o questions  

E-print Network

Floating point o questions o co-processor o SPARC instructions o example o double-floats o quad-floats o Intel floating point 1 #12; Floating Point Questions o why use sign/magnitude instead of 2's complement

Biagioni, Edoardo S.

46

The Northern Lights: Aurora Activity and Latitude  

NSDL National Science Digital Library

This activity allows students to make and use a geographic plot of aurora location and activity to create their own forecasting relationship for a selected longitude in North America. They will discover that there is a relationship between the appearance of the aurora and the amount of disturbance to Earth's magnetic field and as the magnetic field becomes more disturbed, the Northern Lights will be visible further south from the Arctic region. By measuring these disturbances, they can predict what the latitude of the southern edge of the Northern Lights will be.

Sten Odenwald

47

Photomechanics of light-activated polymers  

NASA Astrophysics Data System (ADS)

Light-activated polymers are an exciting class of modern materials that respond mechanically when irradiated by light at particular wavelengths. While details of the mechanisms that connect the optical excitation to mechanical behavior are complex and differ from material to material, there is sufficient commonality among them to permit the development of a generalized modeling framework to describe the photomechanics. The features shared by light-activated polymers involve light interacting with the material, which triggers photochemical reactions that alter the structure of the crosslinked polymer network. Many such structural alterations result in an evolution of the polymer network, and subsequent macroscopic deformation. When this process is appropriately executed it can enable a photomechanical shape-memory effect. In this paper, we develop a three-dimensional finite-deformation modeling framework to describe the photomechanical response of light-activated polymer systems. This framework integrates four coupled phenomena that contribute to macroscopic photomechanical behavior: photophysics, photochemistry, chemomechanical coupling, and mechanical deformation. The chemomechanical coupling consists of chemically induced structural alterations of the crosslinked network that result in subsequent deformation. We describe this behavior through a decomposition of the crosslinked network into two components consisting of an original network and a photochemically altered network; both evolve during photomechanical deformation. The modeling framework presented in this paper is sufficiently general that it is applicable to light-activated polymer systems that operate with various mechanisms in each of the four areas. Using this modeling approach, we develop constitutive models for two recently developed light-activated polymer systems [Lendlein, A., Hongyan, J., Junger, O., Langer, R., 2005. Light-induced shape-memory polymers. Nature 434 (7035) 879; Scott, T.F., Schneider, A.D., Cook, W.D., Bowman, C.N., 2005. Photoinduced plasticity in crosslinked polymers. Science 308 (5728) 1615]. For the material developed by Scott and his co-workers we validate our model by measuring and numerically simulating photo-induced stress relaxation and bending deformation and obtain good agreement between measurements and predictions. Finally, we use the model to study the effects of photomechanical parameters (applied strain magnitude, irradiation time and intensity, and photoabsorber concentration) and the behavior of the network evolution rule on the material response.

Long, Kevin N.; Scott, Timothy F.; Jerry Qi, H.; Bowman, Christopher N.; Dunn, Martin L.

2009-07-01

48

Floating apparatus for recovery of floating oil  

Microsoft Academic Search

The invention describes a device for recovering oil floating on the surface of water. The device is a floating vessel which is maneuverable at will in order effectively to recover all of an oil slick floating on the surface of the water. The device includes paddle wheel means to skim the oil from the surface of the water. The oil

G. Mascarin; S. P. Mellina

1981-01-01

49

Light Activated Self-Propelled Colloids  

E-print Network

Light-activated self-propelled colloids are synthesized and their active motion is studied using optical microscopy. We propose a versatile route using different photoactive materials, and demonstrate a multiwavelength activation and propulsion. Thanks to the photoelectrochemical properties of two semiconductor materials (\\alpha Fe2 O3 and TiO2 ), a light with an energy higher than the bandgap triggers the reaction of decomposition of hydrogen peroxide and produces a chemical cloud around the particle. It induces a phoretic attraction with neighbouring colloids as well as an osmotic self- propulsion of the particle on the substrate. We use these mechanisms to form colloidal cargos as well as self-propelled particles where the light-activated component is embedded into a dielectric sphere. The particles are self-propelled along a direction otherwise randomized by thermal fluctuations, and exhibit a persistent random walk. For sufficient surface density, the particles spontaneously form "living crystals" which are mobile, break apart and reform. Steering the particle with an external magnetic field, we show that the formation of the dense phase results from the collisions heads-on of the particles. This effect is intrinsically non-equilibrium and a novel principle of organization for systems without detailed balance. Engineering families of particles self-propelled by different wavelength demonstrate a good understanding of both the physics and the chemistry behind the system and points to a general route for designing new families of self-propelled particles.

J. Palacci; S. Sacanna; S. -H. Kim; G. -R. Yi; D. J. Pine; P. M. Chaikin

2014-10-27

50

Float valve control  

SciTech Connect

This patent describes a liquid level control device for monitoring the level of water in a steam generating tank between predetermined upper, intermediate and lower levels, the tank equipped with a valve for introducing water into the tank and valve means for introducing heat energy to the water to generate steam. The device consists of: (a) a glass gauge tube adapted to be vertically mounted exteriorally of the tank; (b) a top and bottom cover covering the ends of the glass gauge tube, the bottom cover including an opening for communicating with the liquid in the tank and the top cover including an opening for communicating with the steam generated in the tank; (c) upper and lower magnetic float means mounted co-axially within the glass guage tube; (d) the upper magnetic float means including means to activate the water valve when the water is in the region of the predetermined intermediate level so as to introduce water into the tank until the water is in the region of the predetermined upper level, and to deactivate the water valve and stop the introduction of water into the tank when the water is in the region of the predetermined upper level; (e) the lower magnetic float means is adapted to continuously maintain the application of heat energy during the introduction of water at the intermediate level, and the lower magnetic float means is adapted to activate the heat energy valve means to stop the application of heat energy in the steam generating tank when the water is in the region of the predetermined lower level.

Tchitdjian, J.K.

1986-08-12

51

Anomalous Light Phenomena vs. Bioelectric Brain Activity  

NASA Astrophysics Data System (ADS)

We present a research proposal concerning the instrumented investigation of anomalous light phenomena that are apparently correlated with particular mind states, such as prayer, meditation or psi. Previous research by these authors demonstrate that such light phenomena can be monitored and measured quite efficiently in areas of the world where they are reported in a recurrent way. Instruments such as optical equipment for photography and spectroscopy, VLF spectrometers, magnetometers, radar and IR viewers were deployed and used massively in several areas of the world. Results allowed us to develop physical models concerning the structural and time-variable behaviour of light phenomena, and their kinematics. Recent insights and witnesses have suggested to us that a sort of "synchronous connection" seems to exist between plasma-like phenomena and particular mind states of experiencers who seem to trigger a light manifestation which is very similar to the one previously investigated. The main goal of these authors is now aimed at the search for a concrete "entanglement-like effect" between the experiencer's mind and the light phenomena, in such a way that both aspects are intended to be monitored and measured simultaneously using appropriate instrumentation. The goal of this research project is twofold: a) to verify quantitatively the existence of one very particular kind of mind-matter interaction and to study in real time its physical and biophysical manifestations; b) to repeat the same kind of experiment using the same test-subject in different locations and under various conditions of geomagnetic activity.

Teodorani, M.; Nobili, G.

52

Mitochondrial electron transport protects floating leaves of long leaf pondweed (Potamogeton nodosus Poir) against photoinhibition: comparison with submerged leaves.  

PubMed

Investigations were carried to unravel mechanism(s) for higher tolerance of floating over submerged leaves of long leaf pondweed (Potamogeton nodosus Poir) against photoinhibition. Chloroplasts from floating leaves showed~5- and~6.4-fold higher Photosystem (PS) I (reduced dichlorophenol-indophenol?methyl viologen?O2) and PS II (H2O?parabenzoquine) activities over those from submerged leaves. The saturating rate (V max) of PS II activity of chloroplasts from floating and submerged leaves reached at~600 and~230molphotonsm(-2)s(-1), respectively. Photosynthetic electron transport rate in floating leaves was over 5-fold higher than in submerged leaves. Further, floating leaves, as compared to submerged leaves, showed higher F v/F m (variable to maximum chlorophyll fluorescence, a reflection of PS II efficiency), as well as a higher potential to withstand photoinhibitory damage by high light (1,200molphotonsm(-2)s(-1)). Cells of floating leaves had not only higher mitochondria to chloroplast ratio, but also showed many mitochondria in close vicinity of chloroplasts. Electron transport (NADH?O2; succinate?O2) in isolated mitochondria of floating leaves was sensitive to both cyanide (CN(-)) and salicylhydroxamic acid (SHAM), whereas those in submerged leaves were sensitive to CN(-), but virtually insensitive to SHAM, revealing the presence of alternative oxidase in mitochondria of floating, but not of submerged, leaves. Further, the potential of floating leaves to withstand photoinhibitory damage was significantly reduced in the presence of CN(-) and SHAM, individually and in combination. Our experimental results establish that floating leaves possess better photosynthetic efficiency and capacity to withstand photoinhibition compared to submerged leaves; and mitochondria play a pivotal role in protecting photosynthetic machinery of floating leaves against photoinhibition, most likely by oxidation of NAD(P)H and reduction of O2. PMID:25366828

Shabnam, Nisha; Sharmila, P; Sharma, Anuradha; Strasser, Reto J; Govindjee; Pardha-Saradhi, P

2014-11-01

53

Floating layer recovery apparatus  

SciTech Connect

This patent describes an apparatus for recovery of a layer of a first underground liquid floating on a second underground liquid in a well. It comprises: first float means disposed in the well in the first liquid, the float means having an effective buoyancy such that it floats in the first liquid; second float means disposed in the well in the first liquid, the float means having an effective buoyancy such that it floats near the bottom of the first liquid, the second float means having top, side and bottom surfaces; an inlet means disposed on the second float surface for permitting entry of the first liquid; conduit means coupled to the inlet means and extending below the second float means; third float means disposed in the second liquid and having an effective buoyancy such that the third float means will remain submerged in the second liquid, the conduit means being coupled to the third float; the guide means for slidably connecting the second float between the first and third float means.

Newcomer, K.; Richter, S.

1991-03-12

54

Photocatalytically active thin films on float glass with enhanced hydrophilicity and transmission for photovoltaic applications  

Microsoft Academic Search

In this paper, the results on the preparation of photocatalytically active thin films will be presented. The films based on TiO2 and were deposited by using sputtering technique as well as by applying combustion CVD methods. For the determination of the photocatalytically properties of the films the decomposition of stearic acid after UV irradiation was investigated by FT-IR measurements. Additionally,

A. Heft; T. Tlke; A. Pfuch; C. Erbe

2006-01-01

55

CMOS common-mode rejection filter with floating active transformer operation  

NASA Astrophysics Data System (ADS)

We propose an inductorless common-mode rejection filter with a gyrator-C network for common-mode-noise reduction. By adopting a gyrator-C network and ladder structure, high-order and small filter circuits with active transformer operation were fabricated. The filter was designed and fabricated in a Taiwan Semiconductor Manufacturing Company (TSMC) 0.18 m CMOS process. This filter exhibited a CMRR of 80 dB, output noise voltage of 103 nV/Hz1/2, third-order input intercept point of 8.8 dBm at 1 MHz operation, and cutoff frequency of under 6 MHz. The total power consumption was 14.8 mW with a 2.5 V supply, and the chip area was 0.7 0.4 mm2.

Uchida, Daisuke; Ikebe, Masayuki; Motohisa, Junichi; Sano, Eiichi; Kondou, Akira

2014-01-01

56

Suminagashi: Floating Ink Paper Marbling  

NSDL National Science Digital Library

In this activity, learners try to float ink on the surface of water to create a pattern and then capture it with absorbent paper. This technique, called Suminagashi, is an ancient Japanese style of decorating paper with inks and believed to be the oldest form of marbling. This art activity can introduce learners to fluid mechanics, viscosity, and surface tension.

2012-06-26

57

Floating sample-collection platform with stage-activated automatic water sampler for streams with large variation in stage  

USGS Publications Warehouse

A floating sample-collection platform is described for stream sites where the vertical or horizontal distance between the stream-sampling point and a safe location for the sampler exceed the suction head of the sampler. The platform allows continuous water sampling over the entire storm-runoff hydrogrpah. The platform was developed for a site in southern Illinois.

Tarte, Stephen R.; Schmidt, A.R.; Sullivan, Daniel J.

1992-01-01

58

Will It Float?  

NSDL National Science Digital Library

Student preconceptions are one of the greatest challenges we face as science teachers. This Predict, Explain, Observe, and Explain (PEOE) activity challenges students? preconceived notions about why matter floats or sinks when placed in a liquid. The idea behind this model is to do a demonstration that first confirms student's conceptions followed by a second, similar demonstration that provides discrepant information creating cognitive dissonance. Learning happens as students are forced to modify their conceptions so that their view of how things work is not in conflict with what they are seeing.

Jeff Major

2006-01-01

59

Exploring Floating Concrete and Beam Design.  

ERIC Educational Resources Information Center

Presents two construction activities that address both state and federal science standards and encourage students to consider career options in mathematics and science. Includes floating concrete and paper bridge activities. (YDS)

Snell, Billie G.; Snell, Luke M.

2002-01-01

60

Automatic Identification of Float Flowmeter's Float  

Microsoft Academic Search

According to the automatic verification of float flowmeter problems, we put forward a device, and it can acquire float height. An MVC - II - 1MM camera is used to capture flowmeter images, and saves them in computer in the form of BMP files. By some functions, such as the edge detection, filtering, binary, expansion, refined, etc, and other algorithms

Xiao-xuan Cao; Yu-ming Shen

2010-01-01

61

The Design of Floats  

NASA Technical Reports Server (NTRS)

Following a summary of the multiplicity of domestic and foreign floats and a brief enumeration of the requirements of floats, the essential form parameters and their effect on the qualities of floats are detailed. On this basis a standard float design is developed which in model families with varying length/beam ratio and angle of dead rise is analyzed by an experimental method which permits its best utilization on any airplane.

Sottorf, W

1938-01-01

62

Potato Float  

NSDL National Science Digital Library

This is a hands-on lab activity about seawater density, specifically the relationship between density of fluid, weight of an object, and buoyancy. Learners will develop hypotheses and observe a demonstration of density to understand its role in buoyancy. They will also examine the effect of salinity on density. Background information, common preconceptions, a glossary and more is included. This activity is part of the Aquarius Hands-on Laboratory Activities.

63

Floating-Point (Applications  

E-print Network

Number Theory and Floating-Point Numbers (Applications de la th#19; eorie des nombres aux An Interview with the Old Man of Floating-Point, interview from William Kahan (Turing Award 1989) by Charles on Floating-Point Invertible Numbers, 2001, to appear in Theoretical Computer Science. Theorem 1. For r = 0; 1

Zimmermann, Paul

64

SOFAR floats for POLYMODE  

Microsoft Academic Search

The design of a neutrally buoyant float and associated tracking and support equipment developed for the POLYMODE experiment is described. Floats with a signaling range of 1500 Km and an endurance of 2-1\\/2 years signal via the deep sound channel to both land based receiving stations and moored, portable receivers. Recordings of float signals are collected and centrally processed, providing

Douglas C. Webb

1977-01-01

65

Potato Float  

NSDL National Science Digital Library

How can a potato wedge be made to hover in the center of a glass of liquid? This material is part of a series of hands-on science activities designed to arouse student interest. Here students investigate density using potato wedges and water and sugar water solutions. The activity includes a description, a list of science process skills and complex reasoning strategies being used, and a compilation of applicable national science standards for grades K-12. Also provided are content topics, a list of necessary supplies, instructions to perform the activity, and presentation techniques. The activity's content is explained, and assessment suggestions are provided.

Mid-continent Research for Education and Learning (McREL)

2004-01-01

66

Floating Candles  

NSDL National Science Digital Library

In this chemistry activity, learners observe a combustion reaction and deduce the components necessary for the reaction to occur. They will also see the relationship between pressure, volume, and number of molecules for gasses. This activity, which can also be conducted as a demonstration, illustrates Charles's Law and Boyle's Law.

2014-01-28

67

Light-Triggered Myosin Activation for Probing Dynamic Cellular Processes  

E-print Network

Shining light on myosin: The incorporation of a caging group onto the essential phosphoserine residue of myosin by protein semisynthesis enables light-triggered activation of the protein (see picture). Caging eliminates ...

Goguen, Brenda N.

68

Mitigating Impacts of Overwater Floats on Eelgrass Zostera marina l. in Puget Sound, Washington  

Microsoft Academic Search

The effects of using light-permeable deck grating on residential floats constructed over eelgrass (Zostera marina) was examined in the northern Puget Sound region of Washington to test the hypothesis that light permeable deck grating, inserted within the surface of a residential float would prevent loss of eelgrass underneath and adjacent to the float. Eelgrass shoot densities prior to construction of

Kurt L. Fresh; Brian W. Williams; Sandy Wyllie-Echeverria; Tina Wyllie-Echeverria

69

National Synchrotron Light Source 2010 Activity Report  

SciTech Connect

This is a very exciting period for photon sciences at Brookhaven National Laboratory. It is also a time of unprecedented growth for the Photon Sciences Directorate, which operates the National Synchrotron Light Source (NSLS) and is constructing NSLS-II, both funded by the Department of Energy's Office of Science. Reflecting the quick pace of our activities, we chose the theme 'Discovery at Light Speed' for the directorate's 2010 annual report, a fiscal year bookended by October 2009 and September 2010. The year began with the news that NSLS users Venki Ramakrishnan of Cambridge University (also a former employee in Brookhaven's biology department) and Thomas A. Steitz of Yale University were sharing the 2009 Nobel Prize in Chemistry with Ada E. Yonath of the Weizmann Institute of Science. Every research project has the potential for accolades. In 2010, NSLS users and staff published close to 900 papers, with about 170 appearing in premiere journals. Those are impressive stats for a facility nearly three decades old, testament to the highly dedicated team keeping NSLS at peak performance and the high quality of its user community. Our NSLS users come from a worldwide community of scientists using photons, or light, to carry out research in energy and environmental sciences, physics, materials science, chemistry, biology and medicine. All are looking forward to the new capabilities enabled by NSLS-II, which will offer unprecedented resolution at the nanoscale. The new facility will produce x-rays more than 10,000 times brighter than the current NSLS and host a suite of sophisticated instruments for cutting-edge science. Some of the scientific discoveries we anticipate at NSLS-II will lead to major advances in alternative energy technologies, such as hydrogen and solar. These discoveries could pave the way to: (1) catalysts that split water with sunlight for hydrogen production; (2) materials that can reversibly store large quantities of electricity or hydrogen; (3) high-temperature superconducting materials that carry electricity with no loss for efficient power transmission lines; and (4) materials for solid-state lighting with half of the present power consumption. Excitement about NSLS-II is evident in many ways, most notably the extraordinary response we had to the 2010 call for beamline development proposals for the anticipated 60 or more beamlines that NSLS-II will ultimately host. A total of 54 proposals were submitted and, after extensive review, 34 were approved. Funding from both the Department of Energy and the National Institutes of Health has already been secured to support the design and construction of a number of these beamlines. FY11 is a challenging and exciting year for the NSLS-II Project as we reach the peak of our construction activity. We remain on track to complete the project by March 2014, a full 15 months ahead of schedule and with even more capabilities than originally planned. The Photon Sciences Directorate is well on its way to fulfilling our vision of being a provider of choice for world-class photon sciences and facilities.

Rowe, M.; Snyder, K. J.

2010-12-29

70

Active switching in metamaterials using polarization control of light  

E-print Network

We demonstrate on-demand control of localized surface plasmons in metamaterials by means of incident light polarization. An asymmetric mode, selectively excited by s-polarized light, interfere destructively with a bright element, thereby allowing the incident light to propagate at a fairly low loss, corresponding to electromagnetically induced transparency (EIT) in an atomic system. In contrast, a symmetric mode, excited by p-polarized light, directly couples with the incident light, which is analogous to the switch-off of EIT. The light polarization-dependent excitation of asymmetric and symmetric plasmon modes holds potential for active switching applications of plasmon hybridization.

Hua Xu; Byoung Seung Ham

2010-10-11

71

Floating portable pump  

SciTech Connect

A floating portable pump is constructed of a float defining a well for containing water, a centrifugal pump supported on the float with its impeller shaft extending vertically and with its suction inlet submerged in water in the well, and an internal combustion engine arranged to drive the pump impeller. The pump and engine are secured together on the float in an arrangement such that the engine causes rotation of the pump impeller to cause the pump to draw water from the well through its suction inlet and discharge water from the pump discharge.

Eberhardt, H. A.

1985-11-19

72

Lighting and Electrical Plan Class Activity  

NSDL National Science Digital Library

This class exercise asks students to complete a lighting and electrical plan for a building in the most energy efficient approach possible. They will be given a floor plan to work with, and will then determine which outlets, types of lighting and switches to use. This document may be downloaded in Microsoft Word Doc file format.

Wolf, Arlynne

73

Optical activity in the scattering of structured light.  

PubMed

We observe that optical activity in light scattering can be probed using types of illuminating light other than single plane (or quasi plane) waves and that this introduces new possibilities for the study of molecules and atoms. We demonstrate this explicitly for natural Rayleigh optical activity which, we suggest, could be exploited as a new form of spectroscopy for chiral molecules through the use of illuminating light comprised of two plane waves that are counter propagating. PMID:25315363

Cameron, Robert P; Barnett, Stephen M

2014-12-21

74

Artificial photosynthesis: Light-activated calcium gradients  

NASA Astrophysics Data System (ADS)

Photosynthetic organisms use light to create chemical gradients across bilayer membranes that drive energetically unfavourable reactions. Synthetic systems that accomplish the same feat may find uses in a variety of biological and non-biological applications.

Thompson, David H.

2002-12-01

75

Advanced Light Source Activity Report 2002  

SciTech Connect

This annual report of the Advanced Light Source details science highlights and facility improvements during the year. It also offers information on events sponsored by the facility, technical specifications, and staff and publication information.

Duque, Theresa; Greiner, Annette; Moxon, Elizabeth; Robinson, Arthur; Tamura, Lori (Editors)

2003-06-12

76

Light and dark active phosphodiesterase regulation in salamander rods  

PubMed Central

We studied the activation of 3',5'-cyclic guanosine monophosphate (cGMP) phosphodiesterase (PDE) by using a cell-permeant enzyme inhibitor. Rods of Ambystoma tigrinum held in a suction electrode were jumped into a stream of 3-isobutyl-1-methylxanthine (IBMX), 0.01-1 mM. Initial transient light-sensitive currents fit the notion that dark and light-activated forms of PDE contributed independently to metabolic activity and were equivalently inhibited by IBMX (apparent Ki 30 microns). Inhibition developed within 50 ms, producing a step decrease of enzyme velocity, which could be offset by activation with flashes or steps of light. The dark PDE activity was equivalent to light activation of enzyme by 1,000 isomerization rod-1s-1, sufficient to hydrolyze the free cGMP pool (1/e) in 0.6 s. Steady light activated PDE in linear proportion to isomerization rate, the range from darkness to current saturation amounting to a 10-fold increase. The conditions for simultaneous onset of inhibitor and illumination to produce no net change of membrane current defined the apparent lifetime of light- activated PDE, TPDE* = 0.9 s, which was independent of both background illumination and current over the range 0-3 x 10(5) isomerization s-1, from 50 to 0 pA. Adaptation was a function of current rather than isomerization: jumps with different proportions of IBMX concentration to steady light intensity produced equal currents, and followed the same course of adaptation in maintained light, despite a 10-fold difference of illumination. Judged from the delay between IBMX- and light-induced currents, the dominant feedback regulatory site comes after PDE on the signal path. The dark active PDE affects the hydrolytic flux and cytoplasmic diffusion of cGMP, as well as the proportional range of the cGMP activity signal in response to light. PMID:1722240

1991-01-01

77

Float Zone Workshop  

NASA Technical Reports Server (NTRS)

A summary of the Analytical Float Zone Experiment System (AFZES) concept is presented. The types of experiments considered for such a facility are discussed. Reports from various industrial producers and users of float zone material are presented. Special emphasis is placed on state-of-the-art developments in low gravity manufacturing and their applications to space processing.

Naumann, R. J.

1980-01-01

78

Statistical analysis of the metrological properties of float glass  

NASA Astrophysics Data System (ADS)

The radius of curvature, slope error, surface roughness and associated height distribution and power spectral density of uncoated commercial float glass samples have been measured in our Canadian Light Source Optical Metrology Facility, using our Micromap-570 surface profiler and long trace profilometer. The statistical differences in these parameters have been investigated between the tin and air sides of float glass. The effect of soaking the float glass in sulfuric acid to try to dissolve the tin contamination has also been investigated, and untreated and post-treatment surface roughness measurements compared. We report the results of our studies on these float glass samples.

Yates, Brian W.; Duffy, Alan M.

2008-08-01

79

Floating Immittance Function Simulator and Its Applications  

Microsoft Academic Search

A new floating immittance function simulator circuit is proposed using two different active elements, a dual-output second\\u000a generation current conveyor (DO-CCII) and an operational transconductance amplifier (OTA). The presented circuit can realize\\u000a a positive and negative floating inductor, capacitor and resistor depending on the passive component selection. Since the\\u000a passive elements are all grounded, this circuit is suitable for fully

M. Sagbas; U. E. Ayten; H. Sedef; M. Koksal

2009-01-01

80

Measurement of action spectra of light-activated processes  

NASA Astrophysics Data System (ADS)

We report on a new experimental technique suitable for measurement of light-activated processes, such as fluorophore transport. The usefulness of this technique is derived from its capacity to decouple the imaging and activation processes, allowing fluorescent imaging of fluorophore transport at a convenient activation wavelength. We demonstrate the efficiency of this new technique in determination of the action spectrum of the light mediated transport of rhodamine 123 into the parasitic protozoan Giardia duodenalis.

Ross, Justin; Zvyagin, Andrei V.; Heckenberg, Norman R.; Upcroft, Jacqui; Upcroft, Peter; Rubinsztein-Dunlop, Halina H.

2006-01-01

81

Orthogonal control of antibacterial activity with light.  

PubMed

Selection of a single bacterial strain out of a mixture of microorganisms is of crucial importance in healthcare and microbiology research. Novel approaches that can externally control bacterial selection are a valuable addition to the microbiology toolbox. In this proof-of-concept, two complementary antibiotics are protected with photocleavable groups that can be orthogonally addressed with different wavelengths of light. This allows for the light-triggered selection of a single bacterial strain out of a mixture of multiple strains, by choosing the right wavelength. Further improvement toward additional orthogonally addressable antibiotics might ultimately lead to a novel methodology for bacterial selection in complex populations. PMID:25055227

Velema, Willem A; van der Berg, Jan Pieter; Szymanski, Wiktor; Driessen, Arnold J M; Feringa, Ben L

2014-09-19

82

Photo-mechanical patterning with light activated polymers.  

SciTech Connect

Light activated polymers, which are capable of mechanically responding to light, promise to offer exciting, innovative, and unique material capabilities. Such materials include: photo-radical mediated cleavage and reformation of the polymer backbone in cross-linked elastomers that results in local stress relaxation; photo-switching cross-links in shape memory polymers; and photo-isomerization of azobenzene groups contained in liquid crystal elastomers. In this paper, using our recent material model that couples multiphysical processes involved in light-activated polymers, we demonstrate that a variety of patterns can be created on light activated polymer thin films when coupling mechanical deformation with light irradiation. Here, the polymer thin film is first stretched uniaxially or biaxially. Light is then irradiated on the surface of the thin film. After light irradiation, removal external load partially recovers the initial stretching of the polymer thin film and induces patterns. The variation of the geometry of the patterns can be controlled by a variety of parameters such as initial stretching, light intensity, etc. Photo-patterning with light activated polymer therefore offers a novel way to create surface patterns.

Long, Kevin N.; Qi, H. Jerry (University of Colorado, Boulder, CO); Dunn, Martin L. (University of Colorado, Boulder, CO)

2010-11-01

83

Activation of protein splicing with light in  

E-print Network

with the transcription factor phytochrome interacting factor 3 (PIF3) in a light-dependent manner5. PhyB and PIF3, the PhyB- PIF3 dimerization system should be generally useful as a way to transiently induce. To explore this idea, we set out to integrate the PhyB-PIF3 pair into a con- ditional protein splicing (CPS

Cai, Long

84

NATIONAL SYNCHROTRON LIGHT SOURCE ACTIVITY REPORT 1998.  

SciTech Connect

In FY 1998, following the 50th Anniversary Year of Brookhaven National Laboratory, Brookhaven Science Associates became the new Managers of BNL. The new start is an appropriate time to take stock of past achievements and to renew or confirm future goals. During the 1998 NSLS Annual Users Meeting (described in Part 3 of this Activity Report), the DOE Laboratory Operations Board, Chaired by the Under Secretary for Energy, Ernest Moniz met at BNL. By chance all the NSLS Chairmen except Martin Blume (acting NSLS Chair 84-85) were present as recorded in the picture. Under their leadership the NSLS has improved dramatically: (1) The VUV Ring current has increased from 100 mA in October 1982 to nearly 1 A today. For the following few years 10 Ahrs of current were delivered most weeks - NSLS now exceeds that every day. (2) When the first experiments were performed on the X-ray ring during FY1985 the electron energy was 2 GeV and the current up to 100 mA - the X-Ray Ring now runs routinely at 2.5 GeV and at 2.8 GeV with up to 350 mA of current, with a very much longer beam half-life and improved reliability. (3) Starting in FY 1984 the proposal for the Phase II upgrade, mainly for a building extension and a suite of insertion devices and their associated beamlines, was pursued - the promises were delivered in full so that for some years now the NSLS has been running with two undulators in the VUV Ring and three wigglers and an undulator in the X-Ray Ring. In addition two novel insertion devices have been commissioned in the X13 straight. (4) At the start of FY 1998 the NSLS welcomed its 7000th user - attracted by the opportunity for pursuing research with high quality beams, guaranteed not to be interrupted by 'delivery failures', and welcomed by an efficient and caring user office and first class teams of PRT and NSLS staff. R & D have lead to the possibility of running the X-Ray Ring at the higher energy of 2.8 GeV. Figure 1 shows the first user beam, which was provided thereafter for half of the running time in FY 1998. In combination with the development of narrow gap undulators this mode opens the possibility of new undulators which could produce hard X-rays in the fundamental, perhaps up to 10 keV. On 27 September 1998, a low horizontal emittance lattice became operational at 2.584 GeV. This results in approximately a 50% decrease in the horizontal beam-size on dipole bending magnet beamlines, and somewhat less of a decrease on the insertion device lines. The beam lifetime is not degraded by the low emittance lattice. This represents an important achievement, enhancing for all users the x-ray ring brightness. The reduced horizontal emittance electron beam will produce brighter x-ray beams for all the beamlines, both bending magnets and insertion devices, adding to other recent increases in the X-Ray ring brightness. During FY 1999 users will gain experience of the new running mode and plans are in place to do the same at 2.8GeV during further studies sessions. Independent evidence of the reduced emittance is shown in Figure 2. This is a pinhole camera scan showing the X-ray beam profile, obtained on the diagnostic beamline X28. Finally, work has begun to update and refine the proposal of the Phase III upgrade endorsed by the Birgeneau panel and BESAC last year. With the whole NSLS facility in teenage years and with many demonstrated enhancements available, the time has come to herald in the next stage of life at the Light Source.

ROTHMAN,E.

1999-05-01

85

75 FR 75934 - Airworthiness Directives; Apical Industries Inc. (Apical) Emergency Float Kits  

Federal Register 2010, 2011, 2012, 2013, 2014

...Industries Inc. (Apical) Emergency Float Kits AGENCY: Federal...directive (AD) for the Apical emergency float kits installed on certain...may amend the proposed AD in light of those comments. We will...adopting a new AD for the Apical emergency float kits installed on...

2010-12-07

86

Rhenium complexes with visible-light-induced anticancer activity.  

PubMed

Shedding light on the matter: Rhenium(I) indolato complexes with highly potent visible-light-triggered antiproliferative activity (complex 1: EC50 light=0.1 ?M vs EC50 dark=100 ?M) in 2D- and 3D-organized cancer cells are reported and can be traced back to an efficient generation of singlet oxygen, causing rapid morphological changes and an induction of apoptosis. PMID:23568508

Kastl, Anja; Dieckmann, Sandra; Whler, Kathrin; Vlker, Timo; Kastl, Lena; Merkel, Anna Lena; Vultur, Adina; Shannan, Batool; Harms, Klaus; Ocker, Matthias; Parak, Wolfgang J; Herlyn, Meenhard; Meggers, Eric

2013-06-01

87

Floating emitter solar cell  

NASA Technical Reports Server (NTRS)

A front surface contact floating emitter solar cell transistor is provided in a semiconductor body (n-type), in which floating emitter sections (p-type) are diffused or implanted in the front surface. Between the emitter sections, a further section is diffused or implanted in the front surface, but isolated from the floating emitter sections, for use either as a base contact to the n-type semiconductor body, in which case the section is doped n+, or as a collector for the adjacent emitter sections.

Chih, Sah (inventor); Cheng, Li-Jen (inventor)

1987-01-01

88

bioLights: Light emitting wear for visualizing lower-limb muscle activity  

Microsoft Academic Search

Analysis of muscle activity by electrophysiological techniques is commonly used to analyze biomechanics. Although the simultaneous and intuitive understanding of both muscle activity and body motion is important in various fields, it is difficult to realize. This paper proposes a novel technique for visualizing physiological signals related to muscle activity by means of surface electromyography. We developed a wearable light-emitting

Naoto Igarashi; Kenji Suzuki; Hiroaki Kawamoto; Yoshiyuki Sankai

2010-01-01

89

National Synchrotron Light Source 2008 Activity Report  

SciTech Connect

Funded by the U.S. Department of Energy's Office of Basic Energy Sciences, the National Synchrotron Light Source (NSLS) is a national user facility that operates two electron storage rings: X-Ray (2.8 GeV, 300 mA) and Vacuum Ultraviolet (VUV) (800 mev, 1.0A). These two rings provide intense light spanning the electromagnetic spectrum -- from very long infrared rays to ultraviolet light and super-short x-rays -- to analyze very small or highly dilute samples. The properties of this light, and the specially designed experimental stations, called beamlines, allow scientists in many diverse disciplines of research to perform experiments not possible at their own laboratories. Each year, about 2,200 scientists from more than 400 universities and companies use the NSLS for research in such diverse fields as biology, physics, chemistry, geology, medicine, and environmental and materials sciences. For example, researchers have used the NSLS to examine the minute details of computer chips, decipher the structures of viruses, probe the density of bone, determine the chemical composition of moon rocks, and reveal countless other mysteries of science. The facility has 65 operating beamlines, with 51 beamlines on the X-Ray Ring and 14 beamlines on the VUV-Infrared Ring. It runs seven days a week, 24 hours a day throughout the year, except during periods of maintenance and studies. Researchers are not charged for beam time, provided that the research results are published in open literature. Proprietary research is conducted on a full-cost-recovery basis. With close to 1,000 publications per year, the NSLS is one of the most prolific scientific facilities in the world. Among the many accolades given to its users and staff, the NSLS has won nine R&D 100 Awards for innovations ranging from a closed orbit feedback system to the first device able to focus a large spread of high-energy x-rays. In addition, a visiting NSLS researcher shared the 2003 Nobel Prize in Chemistry for work explaining how one class of proteins helps to generate nerve impulses.

Nasta,K.

2009-05-01

90

Micromechanisms with floating pivot  

SciTech Connect

A new class of tilting micromechanical mechanisms have been developed. These new mechanisms use floating pivot structures to relieve some of the problems encountered in the use of solid flexible pivots.

Garcia, Ernest J. (Albuquerque, NM)

2001-03-06

91

The Floating Reference Librarian  

ERIC Educational Resources Information Center

The floating librarian'' is one who interprets and adjusts the formal library structure to meet legitimate needs. This is one of the ways the academic reference librarian can gain greater acceptance with students and faculty. (9 references) (Author/NH)

Hernon, Peter; Pastine, Maureen

1972-01-01

92

Concrete production floating platforms  

SciTech Connect

The floating production platforms operating in the North Sea are adapted from drilling semisubmersibles which allow only a limited payload capacity. Experience of concrete production platforms constructed for the North Sea has led Sea Tank Co. to propose a floating platform which offers large payload and oil storage capacities similar to those of existing fixed platforms. Sea Tank Co. and Institut Francais du Petrole joined forces in early 1976 to study the feasibility of a concrete floating production platform incorporating the structure and the production riser together. The results of this 3-yr program show that the concrete floating structure is economically attractive for permanent utilization on a production site. Furthermore, concrete has definite advantages over other materials, in its long term behavior.

Letourneur, O.; Falcimaigne, J.

1981-01-01

93

Advanced Light Source: Activity report 1993  

SciTech Connect

The Advanced Light Source (ALS) produces the world`s brightest light in the ultraviolet and soft x-ray regions of the spectrum. The first low-energy third-generation synchrotron source in the world, the ALS provides unprecedented opportunities for research in science and technology not possible anywhere else. This year marked the beginning of operations and the start of the user research program at the ALS, which has already produced numerous high quality results. A national user facility located at Lawrence Berkeley Laboratory of the University of California, the ALS is available to researchers from academia, industry, and government laboratories. This report contains the following: (1) director`s message; (2) operations overview; (3) user program; (4) users` executive committee; (5) industrial outreach; (6) accelerator operations; (7) beamline control system; (8) insertion devices; (9) experimental systems; (10) beamline engineering; (11) first results from user beamlines; (12) beamlines for 1994--1995; (13) special events; (14) publications; (15) advisory panels; and (16) ALS staff.

Not Available

1994-11-01

94

Floating Squares (GCMP)  

NSDL National Science Digital Library

Floating Squares: this is a resource in the collection "General Chemistry Multimedia Problems". In this problem we will coat a piece of notecard with graphite (from pencil lead). We then will float the piece in two beakers containing water and a second solvent. General Chemistry Multimedia Problems ask students questions about experiments they see presented using videos and images. The questions asked apply concepts from different parts of an introductory course, encouraging students to decompartmentalize the material.

95

Light-Activated Pharmaceuticals: Mechanisms and Detection  

PubMed Central

Photodynamic therapy relies on the interaction between light, oxygen and a photosensitizing agent. Its medical significance relates to the ability of certain agents, usually based on porphyrin or phthalocyanine structures, to localize somewhat selectively in neoplastic cells and their vasculature. Subsequent irradiation, preferably at a sufficiently high wavelength to have a significant pathway through tissues, results in a photophysical reaction whereby the excited state of the photosensitizing agent transfers energy to molecular oxygen and results in the formation of reactive oxygen species. Analogous reactive nitrogen species are also formed. These contain both nitrogen and oxygen atoms. The net result is both direct tumor cell death and a shutdown of the tumor vasculature. Other processes may also occur that promote the anti-tumor response but these are outside the scope of this review. PMID:23990688

Kessel, David; Reiners, John

2013-01-01

96

Floating wind turbine system  

NASA Technical Reports Server (NTRS)

A floating wind turbine system with a tower structure that includes at least one stability arm extending therefrom and that is anchored to the sea floor with a rotatable position retention device that facilitates deep water installations. Variable buoyancy for the wind turbine system is provided by buoyancy chambers that are integral to the tower itself as well as the stability arm. Pumps are included for adjusting the buoyancy as an aid in system transport, installation, repair and removal. The wind turbine rotor is located downwind of the tower structure to allow the wind turbine to follow the wind direction without an active yaw drive system. The support tower and stability arm structure is designed to balance tension in the tether with buoyancy, gravity and wind forces in such a way that the top of the support tower leans downwind, providing a large clearance between the support tower and the rotor blade tips. This large clearance facilitates the use of articulated rotor hubs to reduced damaging structural dynamic loads. Major components of the turbine can be assembled at the shore and transported to an offshore installation site.

Viterna, Larry A. (Inventor)

2009-01-01

97

Advanced light source. Activity report 1995  

SciTech Connect

The ALS Activity Report is designed to share the breadth, variety, and interest of the scientific program and ongoing R&D efforts in a form that is accessible to a broad audience. Recent research results are presented in six sections, each representing an important theme in ALS science. These results are designed to demonstrate the capabilities of the ALS, rather than to give a comprehensive review of 1995 experiments. Although the scientific program and facilities report are separate sections, in practice the achievements and accomplishments of users and ALS staff are interdependent. This user-staff collaboration is essential to help us direct our efforts toward meeting the needs of the user community, and to ensure the continued success of the ALS as a premier facility.

NONE

1996-07-01

98

Ecological measurements of light exposure, activity, and circadian disruption  

PubMed Central

Circadian rhythms are biological rhythms that repeat at approximately 24 hours. In humans, circadian rhythms have an average period of 24.2 hours. The 24-hour patterns of light and dark on the retina synchronize circadian rhythms to the local time on earth. Lighting characteristics affecting circadian rhythms are very different than those affecting visual responses. Lack of synchronization between the endogenous clock and the local time has been associated with a host of maladies. Therefore, it is important to measure circadian light exposures over the course of the 24-hour day and to be able to assess circadian entrainment and disruption in actual living environments. Presented is an overview of the recently developed Daysimeter, a personal measurement device for recording activity and circadian light-exposure. When the Daysimeter is worn on the head, two light sensors near the eye are used to estimate circadian light (CLA) exposures over extended periods of time. Phasor analysis combines the measured periodic activity-rest patterns with the measured periodic light-dark patterns to assess behavioural circadian entrainment/disruption. As shown, day-shift and rotating-shift nurses exhibit remarkably different levels of behavioural circadian entrainment/disruption. These new ecological measurement and analysis techniques may provide important insights into the relationship between circadian disruption and well-being. PMID:23504497

Miller, D; Bierman, A; Figueiro, MG; Schernhammer, ES; Rea, MS

2013-01-01

99

Activated Sludge Clarification Using an Advanced DAF Process Based on the Down-Flow Floating Cover Filtration  

Microsoft Academic Search

A novel method for the clarification of activated sludge, using sludge blanket filtration, was proposed. The process was tested continuously with activated sludge over 250days. The proposed process is based on DAF separation, where the mixed liquor is distributed to the surface of the tank, and the clarified effluent is partially recycled with compressed air to the bottom. As a

Ki Yong Lee; Shin Jo Kim; Yong-Woo Lee; Ick Tae Yeom

2011-01-01

100

Floating debris in rivers and lakes in Serbia  

Microsoft Academic Search

An analysis of floating debris is conducted. It was found that components of debris is similar to the municipal waste and consists of plastic bags, bottles and glasses, tires, dead branches and tree trunks, aluminium waste, mud, etc. Floating debris cause pollution of water bodies and disturb activities related to the use and regulation of water recourses. It is suggested

Danica Zupanski

101

What Floats Your Boat?  

NSDL National Science Digital Library

Students use modeling clay, a material that is denser than water and thus ordinarily sinks in water, to discover the principle of buoyancy. They begin by designing and building boats out of clay that will float in water, and then refine their designs so that their boats will carry as great a load (metal washers) as possible. Building a clay boat to hold as much weight as possible is an engineering design problem. Next, they compare amount of water displaced by a lump of clay that sinks to the amount of water displaced by the same lump of clay when it is shaped so as to float. Determining the masses of the displaced water allows them to arrive at Archimedes' principle, whereby the mass of the displaced water equals the mass of the floating clay boat.

2014-09-18

102

Floating platform with monolithically formed float members and platform  

Microsoft Academic Search

Floating platforms for various offshore facilities are formed of float members monolithically connected to a superposed platform. The float members are spherically shaped and are formed of reinforced or prestressed concrete. The platform can be a hollow planar member or it can be curved in one or two directions, and the platforms are formed of prestressed concrete. Cylindrical shafts can

Finsterwalder

1981-01-01

103

Gauge well float for floating root storage tanks  

Microsoft Academic Search

A gauge well float includes a sealed cylinder having rounded ends. A tube is disposed along the vertical axis of the cylinder and held in place by the rounded ends. A weighted cable suspended within the gauge well passes through the tube and keeps the float centered within the gauge well. It also provides a means for removing the float

J. A. Sayles; W. J. Norwood

1984-01-01

104

Floating Versus Sinking  

NASA Astrophysics Data System (ADS)

Small objects that are more dense than water may still float at the air-water interface because of surface tension. Whether this is possible depends not only on the density and size of the object, but also on its shape and surface properties, whether other objects are nearby, and how gently the object is placed at the interface. This review surveys recent work to quantify when objects can float and when they must sink. Much interest in this area has been driven by studies of the adaptations of water-walking insects to life at interfaces. I therefore discuss these results in the context of this and other applications.

Vella, Dominic

2015-01-01

105

Effect of light units on tooth bleaching with visible-light activating titanium dioxide photocatalyst.  

PubMed

This study evaluated the influence of different light sources on the efficiency of an office bleaching agent containing visible-light activating titanium dioxide photocatalyst (VL-TiO(2)) using an artificial discoloration tooth model. Extracted bovine teeth were stained by black tea. The CIE L*a*b* values were measured before and after nine consecutive treatments by the VL-TiO(2)-containing bleaching agent (TiON in Office, GC, Tokyo, Japan). A halogen light unit (CB; CoBee, GC) or an LED unit (G-light, GC) with two modes (blue and violet: GL-BV, blue: GL-B) were used to activate the bleaching agent in three groups (n=8). Brightness (?L) and color difference (?E) increased as bleaching repeated in all groups. Two-way ANOVA showed that both number of treatments and light sources significantly affected ?E (p<0.05). GL-BV showed better bleaching effect than GL-B. In measurement of irradiation spectra, CB showed a wide spectrum (380-530 nm), GL-B had a sharp peak at 470 nm and GL-BV showed an additional peak at 405 nm. It was concluded that the light source influenced the efficiency of the tooth bleaching with VL-TiO(2). PMID:21946494

Kishi, Ayaka; Otsuki, Masayuki; Sadr, Alireza; Ikeda, Masaomi; Tagami, Junji

2011-01-01

106

76 FR 10564 - Takes of Marine Mammals Incidental to Specified Activities; St. George Reef Light Station...  

Federal Register 2010, 2011, 2012, 2013, 2014

...to Specified Activities; St. George Reef Light Station Restoration and Maintenance at Northwest...operations, and lighthouse renovation and light maintenance activities on the St. George Reef Light Station on Northwest Seal Rock (NWSR)...

2011-02-25

107

Compound floating pivot micromechanisms  

DOEpatents

A new class of tilting micromechanical mechanisms have been developed. These new mechanisms use compound floating pivot structures to attain far greater tilt angles than are practical using other micromechanical techniques. The new mechanisms are also capable of bi-directional tilt about multiple axes.

Garcia, Ernest J. (Albuquerque, NM)

2001-04-24

108

Corona from floating electrodes  

Microsoft Academic Search

It is not unusual to have insulated conducting objects located close to the conductors of a Lightning Protection System. However, the separation of these objects from the Lightning Protection System could vary from a few millimetres to some centimetres. When the system is exposed to thunderstorm electric fields, discharge could be initiated between the Lightning Protection System and the floating

Francisco Roman; Vernon Cooray; Viktor Scuka

1996-01-01

109

Floating Vegetation in Pantanal  

USGS Multimedia Gallery

Mass of floating vegetation (embalsado) on Rio Negro river along the border between Paraguay and Bolivia. Located near RAMSAR site and Rio Negro National Park in the Pantanal ecoregion. This region, situated in the extreme northeastern corner of western Paraguay and extending south along the Paragua...

110

Floating Vegetation in Pantanal  

USGS Multimedia Gallery

Mass of floating vegetation (embalsado)on Rio Negro river on the border between Paraguay and Bolivia. Located near RAMSAR site and Rio Negro National Park in the Pantanal ecoregion. This region, situated in the extreme northeastern corner of western Paraguay and extending south along the Paraguay ri...

111

Antimicrobial Properties of Light-activated Polyurethane Containing Indocyanine Green  

Microsoft Academic Search

The aim of this study was to produce novel antimicrobial polymers containing the light-activated antimicrobial agent indocyanine green (ICG). The novel materials were prepared by swelling polyurethane in acetone containing water and ICG, followed by solvent evaporation. The uptake of ICG was dependent upon the ratio of acetone to water. Only at a ratio of 99 parts acetone to 1

Stefano Perni; Jonathan Pratten; Michael Wilson; Clara Piccirillo; Ivan P. Parkin; Polina Prokopovich

2011-01-01

112

Advanced Light Source Activity Report 1997/1998  

SciTech Connect

This Lawrence Berkeley National Laboratory, Advanced Light Source (ALS) activity report for 1997/98 discusses the following topics: Introduction and Overview; Science Highlights; Facility Report; Special Events; ALS Advisory Panels 1997/98; ALS Staff 1997/98 and Facts and Figures for the year.

Greiner, Annette (ed.)

1999-03-01

113

Selenium bond decreases ON resistance of light-activated switch  

NASA Technical Reports Server (NTRS)

Vitrified amorphous selenium bond decreases the ON resistance of a gallium arsenide-silicon light-activated, low-level switch. The switch is used under a pulse condition to prolong switch life and minimize errors due to heating, devitrification, and overdrawing.

1965-01-01

114

Floating and Falling Flows  

NSDL National Science Digital Library

Students discover fluid dynamics related to buoyancy through experimentation and optional photography. Using one set of fluids, they make light fluids rise through denser fluids. Using another set, they make dense fluids sink through a lighter fluid. In both cases, they see and record beautiful fluid motion. Activities are also suitable as class demonstrations. The natural beauty of fluid flow opens the door to seeing the beauty of physics in general.

2014-09-18

115

Effects of light sources and visible light-activated titanium dioxide photocatalyst on bleaching.  

PubMed

The objective of this study was to evaluate, using methylene blue (MB), the effects of various light sources on the bleaching action of hydrogen peroxide (H(2)O(2)) with two titanium dioxide (TiO(2)) photocatalysts - an ultraviolet light-activated TiO(2) photocatalyst (UVTiO(2)) versus a visible light-activated TiO(2) photocatalyst (VL-TiO(2)). Five experimental solutions (VL-TiO(2)+H(2)O(2), UV-TiO(2)+H(2)O(2), H(2)O(2), VL-TiO(2), UV-TiO(2)) were prepared by mixing varying concentrations of H(2)O(2 )and/or TiO(2 )photocatalyst with MB solution. For H(2)O(2)-containing solutions (VL-TiO(2)+H(2)O(2), UV-TiO(2)+H(2)O(2), and H(2)O(2)), the concentration of H(2)O(2) was adjusted to 3.5%. For the four different light sources, low- and high-intensity halogen lamps and blue LED LCUs were used. All the experimental solutions were irradiated by each of the light sources for 7 minutes, and the absorbance at 660 nm was measured every 30 seconds to determine the concentration of MB as an indicator of the bleaching effect. On the interaction between the effects of light source and bleaching treatment, the high-intensity halogen with VL-TiO(2)+H(2)O(2) caused the most significant reduction in MB concentration. On the effect of light sources, the halogen lamps resulted in a greater bleaching effect than the blue LED LCUs. PMID:20019420

Suyama, Yuji; Otsuki, Masayuki; Ogisu, Shinichiro; Kishikawa, Ryuzo; Tagami, Junji; Ikeda, Masaomi; Kurata, Hiroshi; Cho, Takahiro

2009-11-01

116

Transient and selective suppression of neural activity with infrared light  

PubMed Central

Analysis and control of neural circuitry requires the ability to selectively activate or inhibit neurons. Previous work showed that infrared laser light selectively excited neural activity in endogenous unmyelinated and myelinated axons. However, inhibition of neuronal firing with infrared light was only observed in limited cases, is not well understood and was not precisely controlled. Using an experimentally tractable unmyelinated preparation for detailed investigation and a myelinated preparation for validation, we report that it is possible to selectively and transiently inhibit electrically-initiated axonal activation, as well as to both block or enhance the propagation of action potentials of specific motor neurons. Thus, in addition to previously shown excitation, we demonstrate an optical method of suppressing components of the nervous system with functional spatiotemporal precision. We believe this technique is well-suited for non-invasive investigations of diverse excitable tissues and may ultimately be applied for treating neurological disorders. PMID:24009039

Duke, Austin R.; Jenkins, Michael W.; Lu, Hui; McManus, Jeffrey M.; Chiel, Hillel J.; Jansen, E. Duco

2013-01-01

117

Wiring the retinal circuits activated by light during early development  

PubMed Central

Background Light information is sorted by neuronal circuits to generate image-forming (IF) (interpretation and tracking of visual objects and patterns) and non-image-forming (NIF) tasks. Among the NIF tasks, photic entrainment of circadian rhythms, the pupillary light reflex, and sleep are all associated with physiological responses, mediated mainly by a small group of melanopsin-expressing retinal ganglion cells (mRGCs). Using Xenopus laevis as a model system, and analyzing the c-fos expression induced by light as a surrogate marker of neural activity, we aimed to establish the developmental time at which the cells participating in both systems come on-line in the retina. Results We found that the peripheral retina contains 80% of the two melanopsin-expressing cell types we identified in Xenopus: melanopsin-expressing horizontal cells (mHCs; opn4m+/opn4x+/Prox1+) and mRGCs (2.7% of the total RGCs; opn4m+/opn4x+/Pax6+/Isl1), in a ratio of 6:1. Only mRGCs induced c-fos expression in response to light. Dopaminergic (tyrosine hydroxylase-positive; TH+) amacrine cells (ACs) may be part of the melanopsin-mediated circuit, as shown by preferential c-fos induction by blue light. In the central retina, two cell types in the inner nuclear layer (INL) showed light-mediated induction of c-fos expression [(On-bipolar cells (Otx2+/Isl1+), and a sub-population of ACs (Pax6?/Isl1?)], as well as two RGC sub-populations (Isl1+/Pax6+ and Isl1+/Pax6?). Melanopsin and opsin expression turned on a day before the point at which c-fos expression could first be activated by light (Stage 37/38), in cells of both the classic vision circuit, and those that participate in the retinal component of the NIF circuit. Key to the classic vision circuit is that the component cells engage from the beginning as functional unit circuits of two to three cells in the INL for every RGC, with subsequent growth of the vision circuit occurring by the wiring in of more units. Conclusions We identified melanopsin-expressing cells and specific cell types in the INL and the RGC layer which induce c-fos expression in response to light, and we determined the developmental time when they become active. We suggest an initial formulation of retinal circuits corresponding to the classic vision pathway and melanopsin-mediated circuits to which they may contribute. PMID:24521229

2014-01-01

118

Design, Synthesis, and Cercaricidal Activity of Novel High-efficient, Low-toxic Self-spreading PEG-N-salicylanilide Derivatives Against Cercariae Larvae of Schistosome Japonicum Floating on the Water Surface.  

PubMed

Novel cercaricides of PEG-N-salicylanilide derivatives that could self-spread and float on the water surface were designed and synthesized according to the particular habit of cercariae larvae of Schistosome japonicum. The structures of the cercaricides were characterized by the infrared spectra (IR), magnetic resonance ((1) H NMR), and mass spectrum (MS). The images of the floating cercaricides on the water surface were investigated by the Brewster angle microscopy (BAM). When the cercaricides were dropped on the water surface, they could spread along the air-water interface automatically and form thin membranes floating on the water surface immediately. The lethality rate of cercariae for 5a and 6a was more than 90% in 120min at a surface concentration of 0.008mg/cm(2) . The non-ionic surfactant-cercaricides not only showed strong cercaricidal activities against the cercariae larvae but also exhibited low toxicities, which offered an effective and environment-friendly approach for the reduction of population infection rate and the realization of schistosome control. PMID:25244005

Guo, Wei; Zheng, Lv-Yin; Wu, Ren-Miao; Fan, Xiao-Lin

2015-05-01

119

Channelrhodopsins: visual regeneration and neural activation by a light switch  

PubMed Central

The advent of optogenetics provides a new direction for the field of neuroscience and biotechnology, serving both as a refined investigative tool and as potential cure for many medical conditions via genetic manipulation. Although still in its infancy, recent advances in optogenetics has made it possible to remotely manipulate in vivo cellular functions using light. Coined Nature Methods Method of the Year in 2010, the optogenetic toolbox has the potential to control cell, tissue and even animal behaviour. This optogenetic toolbox consists of light-sensitive proteins that are able to modulate membrane potential in response to light. Channelrhodopsins (ChR) are light-gated microbial ion channels, which were first described in green algae. ChR2 (a subset of ChR) is a seven transmembrane a helix protein, which evokes membrane depolarization and mediates an action potential upon photostimulation with blue (470 nm) light. By contrast to other seven-transmembrane proteins that require second messengers to open ion channels, ChR2 form ion channels themselves, allowing ultrafast depolarization (within 50 milliseconds of illumination). It has been shown that integration of ChR2 into various tissues of mice can activate neural circuits, control heart muscle contractions, and even restore breathing after spinal cord injury. More compellingly, a plethora of evidence has indicated that artificial expression of ChR2 in retinal ganglion cells can reinstate visual perception in mice with retinal degeneration. PMID:23664865

Natasha, G; Tan, Aaron; Farhatnia, Yasmin; Rajadas, Jayakumar; Hamblin, Michael R.; Khaw, Peng T.; Seifalian, Alexander M.

2013-01-01

120

Channelrhodopsins: visual regeneration and neural activation by a light switch.  

PubMed

The advent of optogenetics provides a new direction for the field of neuroscience and biotechnology, serving both as a refined investigative tool and as potential cure for many medical conditions via genetic manipulation. Although still in its infancy, recent advances in optogenetics has made it possible to remotely manipulate in vivo cellular functions using light. Coined Nature Methods' 'Method of the Year' in 2010, the optogenetic toolbox has the potential to control cell, tissue and even animal behaviour. This optogenetic toolbox consists of light-sensitive proteins that are able to modulate membrane potential in response to light. Channelrhodopsins (ChR) are light-gated microbial ion channels, which were first described in green algae. ChR2 (a subset of ChR) is a seven transmembrane ? helix protein, which evokes membrane depolarization and mediates an action potential upon photostimulation with blue (470 nm) light. By contrast to other seven-transmembrane proteins that require second messengers to open ion channels, ChR2 form ion channels themselves, allowing ultrafast depolarization (within 50 milliseconds of illumination). It has been shown that integration of ChR2 into various tissues of mice can activate neural circuits, control heart muscle contractions, and even restore breathing after spinal cord injury. More compellingly, a plethora of evidence has indicated that artificial expression of ChR2 in retinal ganglion cells can reinstate visual perception in mice with retinal degeneration. PMID:23664865

G, Natasha; Tan, Aaron; Farhatnia, Yasmin; Rajadas, Jayakumar; Hamblin, Michael R; Khaw, Peng T; Seifalian, Alexander M

2013-06-25

121

Hidden force floating ice  

E-print Network

Because of the segmental specific-heat disparity of the hydrogen bond (O:H-O) and the Coulomb repulsion between oxygen ions, cooling elongates the O:H-O bond at freezing by stretching its containing angle and shortening the H-O bond with an association of larger O:H elongation, which makes ice less dense than water, allowing it to float.

Chang Q. Sun

2015-01-17

122

Analysis of an Anomaly: The Increase in Time Float following Consumption  

PubMed Central

One fundamental axiom for project plan and schedule relates to the notion that time float will be reduced following its consumption. However, an anomalous scenario can emerge in which an activity's time float increases following its consumption. By exploring the associations between time float and paths in activity networks, we (a) reveal the conditions under which the anomaly occurs and (b) summarize laws related to total float. An activity's total float increases in parallel with its duration prolongation within a given boundary but remains constant or decreases in parallel with a prolongation outside the boundary. Furthermore, whereas a prolongation of an activity's duration in excess of classic total float does not delay project completion time, a lag of its start time to a degree slightly greater than the total float does. This analysis reveals different types of total float that correspond to different ways of usage. From this, we offer definitions for translation total float and prolongation total float that deviate from traditional conventions regarding the uniqueness of total float. PMID:25250376

Qi, Jianxun; Su, Zhixiong

2014-01-01

123

WindFloat: A floating foundation for offshore wind turbines  

Microsoft Academic Search

This manuscript summarizes the feasibility study conducted for the WindFloat technology. The WindFloat is a three-legged floating foundation for multimegawatt offshore wind turbines. It is designed to accommodate a wind turbine, 5 MW or larger, on one of the columns of the hull with minimal modifications to the nacelle and rotor. Potential redesign of the tower and of the turbine

Dominique Roddier; Christian Cermelli; Alexia Aubault; Alla Weinstein

2010-01-01

124

Temperature rise during experimental light-activated bleaching.  

PubMed

The purpose of this study was to evaluate the surface and intrapulpal temperatures after treatments with different bleaching gels subjected to different types of light activation. A K-type thermocouple and infrared thermometer were used to measure the temperature increase during the 15- or 30-min treatment period. Light-emitting diode with a center wavelength of 405nm (LED405), organic light-emitting diode (OLED), and femtosecond laser were tested and compared to ZOOM2. The tooth surface was treated with five bleaching agents and Vaseline which served as a control.The generalized estimating equation (GEE) model was applied for testing the differences in temperature increase. The ZOOM2 light source led to the largest increase in mean pulpal and tooth surface temperatures of 21.1 and 22.8C, followed by focused femtosecond laser which increased the pulpal and surface temperatures by up to 15.7 and 16.8C. Treatments with unfocused femtosecond laser, LED405, and OLED induced significantly lower mean temperature increases (p?light activation, while LED405, OLED, and unfocused femtosecond laser could be safely used. PMID:23780710

Klaric, Eva; Rakic, Mario; Sever, Ivan; Tarle, Zrinka

2015-02-01

125

Novel Floating General Element Simulators Using CBTA  

Microsoft Academic Search

In this study, a novel floating frequency depen- dent negative resistor (FDNR), floating inductor, floating ca- pacitor and floating resistor simulator circuit employing two CBTAs and three passive components is proposed. The pre- sented circuit can realize floating FDNR, inductor, capacitor or resistor depending on the passive component selection. Since the passive elements are all grounded, this circuit is suitable

Umut Engin AYTEN; Mehmet SAGBAS; Norbert HERENCSAR; Jaroslav KOTON

2012-01-01

126

Automatic planning of light source and camera placement for an active photometric stereo system  

Microsoft Academic Search

An automatic planning method of light source and camera placement for an active photometric stereo system is presented. Since photometric stereo systems normally use multiple light sources fixed to the environment, they cannot avoid shadows caused by surrounding objects. Using a movable light source and adapting its placement actively to the task environment eliminates shadows. Candidate positions for light source

Shigeyuki SAKANE; T. Sato

1991-01-01

127

Active dielectric antenna on chip for spatial light modulation.  

PubMed

Integrated photonic resonators are widely used to manipulate light propagation in an evanescently-coupled waveguide. While the evanescent coupling scheme works well for planar optical systems that are naturally waveguide based, many optical applications are free-space based, such as imaging, display, holographics, metrology and remote sensing. Here we demonstrate an active dielectric antenna as the interface device that allows the large-scale integration capability of silicon photonics to serve the free-space applications. We show a novel perturbation-base diffractive coupling scheme that allows a high-Q planer resonator to directly interact with and manipulate free-space waves. Using a silicon-based photonic crystal cavity whose resonance can be rapidly tuned with a p-i-n junction, a compact spatial light modulator with an extinction ratio of 9.5 dB and a modulation speed of 150 MHz is demonstrated. Method to improve the modulation speed is discussed. PMID:23152946

Qiu, Ciyuan; Chen, Jianbo; Xia, Yang; Xu, Qianfan

2012-01-01

128

Active dielectric antenna on chip for spatial light modulation  

NASA Astrophysics Data System (ADS)

Integrated photonic resonators are widely used to manipulate light propagation in an evanescently-coupled waveguide. While the evanescent coupling scheme works well for planar optical systems that are naturally waveguide based, many optical applications are free-space based, such as imaging, display, holographics, metrology and remote sensing. Here we demonstrate an active dielectric antenna as the interface device that allows the large-scale integration capability of silicon photonics to serve the free-space applications. We show a novel perturbation-base diffractive coupling scheme that allows a high-Q planer resonator to directly interact with and manipulate free-space waves. Using a silicon-based photonic crystal cavity whose resonance can be rapidly tuned with a p-i-n junction, a compact spatial light modulator with an extinction ratio of 9.5 dB and a modulation speed of 150 MHz is demonstrated. Method to improve the modulation speed is discussed.

Qiu, Ciyuan; Chen, Jianbo; Xia, Yang; Xu, Qianfan

2012-11-01

129

Active dielectric antenna on chip for spatial light modulation  

PubMed Central

Integrated photonic resonators are widely used to manipulate light propagation in an evanescently-coupled waveguide. While the evanescent coupling scheme works well for planar optical systems that are naturally waveguide based, many optical applications are free-space based, such as imaging, display, holographics, metrology and remote sensing. Here we demonstrate an active dielectric antenna as the interface device that allows the large-scale integration capability of silicon photonics to serve the free-space applications. We show a novel perturbation-base diffractive coupling scheme that allows a high-Q planer resonator to directly interact with and manipulate free-space waves. Using a silicon-based photonic crystal cavity whose resonance can be rapidly tuned with a p-i-n junction, a compact spatial light modulator with an extinction ratio of 9.5?dB and a modulation speed of 150?MHz is demonstrated. Method to improve the modulation speed is discussed. PMID:23152946

Qiu, Ciyuan; Chen, Jianbo; Xia, Yang; Xu, Qianfan

2012-01-01

130

Float level switch for a nuclear power plant containment vessel  

DOEpatents

This invention is a float level switch used to sense rise or drop in water level in a containment vessel of a nuclear power plant during a loss of coolant accident. The essential components of the device are a guide tube, a reed switch inside the guide tube, a float containing a magnetic portion that activates a reed switch, and metal-sheathed, ceramic-insulated conductors connecting the reed switch to a monitoring system outside the containment vessel. Special materials and special sealing techniques prevent failure of components and allow the float level switch to be connected to a monitoring system outside the containment vessel. 1 figures.

Powell, J.G.

1993-11-16

131

Float level switch for a nuclear power plant containment vessel  

DOEpatents

This invention is a float level switch used to sense rise or drop in water level in a containment vessel of a nuclear power plant during a loss of coolant accident. The essential components of the device are a guide tube, a reed switch inside the guide tube, a float containing a magnetic portion that activates a reed switch, and metal-sheathed, ceramic-insulated conductors connecting the reed switch to a monitoring system outside the containment vessel. Special materials and special sealing techniques prevent failure of components and allow the float level switch to be connected to a monitoring system outside the containment vessel.

Powell, James G. (Clifton Park, NY)

1993-01-01

132

Pulpal temperature rise during light-activated bleaching.  

PubMed

The purpose of this study was to measure intrapulpal temperature rise induced by two kinds of bleaching gels when the tooth was exposed to a variety of light-curing units and a diode laser in vitro. The root portions of 80 extracted intact human maxillary central incisors were sectioned with a carborundum disk approximately 2 mm below the cementoenamel junction perpendicular to the long axis of the teeth. Two bleaching agents containing heat-enhancing colorant was applied to the labial surface. Light-curing units used were a conventional halogen (40 s), a high-intensity halogen (30 s), a light-emitting diode unit (40 s), and a diode laser (15 s). The temperature rise was measured in the pulpal chamber with a J-type thermocouple wire that was connected to a data logger. Ten specimens were used for each system and bleaching-agent combination. Differences between the starting temperature and highest temperature reading were taken and the calculated temperature changes were averaged to determine the mean value in temperature rise. Temperature rise values were compared using two-way analysis of variance (ANOVA) at a preset alpha of 0.05. Temperature rise varied significantly depending on curing unit and diode laser used. The diode laser induced significantly higher temperature increases than any other curing unit (11.7 degrees C). The light-emitting diode unit produced the lowest temperature changes (6.0 degrees C); however, there were no statistically significant differences among the curing units and there were no statistically significant differences between bleaching agents. Light activation of bleaching materials with diode laser caused higher temperature changes as compared to other curing units and the temperature rise detected was viewed as critical for pulpal health. PMID:15497167

Eldeniz, Aye Unverdi; Usumez, Aslihan; Usumez, Serdar; Ozturk, Nilgun

2005-02-15

133

Floating JMaRT  

E-print Network

We define a new partially solvable system of equations that parametrises solutions to six-dimensional N=(1,0) ungauged supergravity coupled to tensor multiplets. We obtain this system by applying a series of dualities on the known floating brane system, imposing that it allows for the JMaRT solution. We construct an explicit multi-centre solution generalising the JMaRT solution, with an arbitrary number of additional BPS centres on a line. We describe explicitly the embedding of the JMaRT solution in this system in five dimensions.

Guillaume Bossard; Stefanos Katmadas

2014-12-16

134

Floating JMaRT  

E-print Network

We define a new partially solvable system of equations that parametrises solutions to six-dimensional N=(1,0) ungauged supergravity coupled to tensor multiplets. We obtain this system by applying a series of dualities on the known floating brane system, imposing that it allows for the JMaRT solution. We construct an explicit multi-centre solution generalising the JMaRT solution, with an arbitrary number of additional BPS centres on a line. We describe explicitly the embedding of the JMaRT solution in this system in five dimensions.

Bossard, Guillaume

2014-01-01

135

Plasmonic Metamaterials for Active and Passive Light Control  

NASA Astrophysics Data System (ADS)

Fundamental study on plasmonics excites surface plasmons opening possibility for stronger light-matter interaction at nanoscales and optical frequencies. On the other hand, metamaterials, known as artificial materials built with designable subwavelength units, offer unprecedented new material properties not existing in nature. By combining unique advantages in these two areas, plasmonic metamaterials gain tremendous momentum for fundamental research interest and potential practical applications through the active and passive interaction with and control of light. This thesis is focused on the theoretical and experimental study of plasmonic metamaterials with tunable plasmonic properties, and their applications in controlling spontaneous emission process of quantum emitters, and manipulating light propagation, scattering and absorption. To break the limitation of surface plasmon properties by existing metal materials, composite- and multilayer-based metamaterials are investigated and their tunable plasmonic properties are demonstrated. Nanopatterned multilayer metamaterials with hyperbolic dispersion relations are further utilized to enhance spontaneous emission rates of molecules at desired frequencies with improved far-field radiative power through the Purcell effect. Theoretical calculations and experimental lifetime characterizations show the tunable broadband Purcell enhancement of 76 fold on the hyperbolic metamaterials that better aligns with spontaneous emission spectra and the emission intensity improvement of 80 fold achieved by the out-coupling effect of nanopatterns. This concept is later applied to quantum-well light emitting devices for improving the light efficiency and modulation speed at blue and green wavelengths. On the passive light manipulation, in contrast to strong plasmonic scattering from metal patterns, anomalously weak scattering by patterns in multilayer hyperbolic metamaterials is observed and experimentally demonstrated to be insensitive to pattern sizes, shapes and incident angles, and has potential applications in scattering cross-section engineering, optical encryption, low-observable conductive probes and opto-electric devices. Lastly, the concept of metamaterials is also extended to selective control of light absorption and reflection for potential solar energy applications. A high-performance spectrally selective coating based on multi-scaled metamaterials is designed and fabricated with 90-95% solar absorptivity and <30% infrared emissivity near the peak of 500 C black body radiation, which can be utilized for designing solar absorbers with high thermal efficiency for future high temperature concentrating solar power systems.

Lu, Danyong Dylan

136

LOW POWER PROBABILISTIC FLOATING POINT MULTIPLIER  

E-print Network

LOW POWER PROBABILISTIC FLOATING POINT MULTIPLIER DESIGN Aman Gupta,,*, Satyam Mandavalli, Vincent Power Probabilistic Design Probabilistic Floating Point Multiplier Low Power Techniques C simulator Floating Point Multiplier Low Power Techniques C simulator · Ray Tracing Application · Simulations

Mooney, Vincent

137

Genetics Home Reference: Floating-Harbor syndrome  

MedlinePLUS

... PubMed Recent literature OMIM Genetic disorder catalog Conditions > Floating-Harbor syndrome On this page: Description Genetic changes ... names Glossary definitions Reviewed December 2012 What is Floating-Harbor syndrome? Floating-Harbor syndrome is a disorder ...

138

Asymmetric photoredox transition-metal catalysis activated by visible light  

NASA Astrophysics Data System (ADS)

Asymmetric catalysis is seen as one of the most economical strategies to satisfy the growing demand for enantiomerically pure small molecules in the fine chemical and pharmaceutical industries. And visible light has been recognized as an environmentally friendly and sustainable form of energy for triggering chemical transformations and catalytic chemical processes. For these reasons, visible-light-driven catalytic asymmetric chemistry is a subject of enormous current interest. Photoredox catalysis provides the opportunity to generate highly reactive radical ion intermediates with often unusual or unconventional reactivities under surprisingly mild reaction conditions. In such systems, photoactivated sensitizers initiate a single electron transfer from (or to) a closed-shell organic molecule to produce radical cations or radical anions whose reactivities are then exploited for interesting or unusual chemical transformations. However, the high reactivity of photoexcited substrates, intermediate radical ions or radicals, and the low activation barriers for follow-up reactions provide significant hurdles for the development of efficient catalytic photochemical processes that work under stereochemical control and provide chiral molecules in an asymmetric fashion. Here we report a highly efficient asymmetric catalyst that uses visible light for the necessary molecular activation, thereby combining asymmetric catalysis and photocatalysis. We show that a chiral iridium complex can serve as a sensitizer for photoredox catalysis and at the same time provide very effective asymmetric induction for the enantioselective alkylation of 2-acyl imidazoles. This new asymmetric photoredox catalyst, in which the metal centre simultaneously serves as the exclusive source of chirality, the catalytically active Lewis acid centre, and the photoredox centre, offers new opportunities for the `green' synthesis of non-racemic chiral molecules.

Huo, Haohua; Shen, Xiaodong; Wang, Chuanyong; Zhang, Lilu; Rse, Philipp; Chen, Liang-An; Harms, Klaus; Marsch, Michael; Hilt, Gerhard; Meggers, Eric

2014-11-01

139

Asymmetric photoredox transition-metal catalysis activated by visible light.  

PubMed

Asymmetric catalysis is seen as one of the most economical strategies to satisfy the growing demand for enantiomerically pure small molecules in the fine chemical and pharmaceutical industries. And visible light has been recognized as an environmentally friendly and sustainable form of energy for triggering chemical transformations and catalytic chemical processes. For these reasons, visible-light-driven catalytic asymmetric chemistry is a subject of enormous current interest. Photoredox catalysis provides the opportunity to generate highly reactive radical ion intermediates with often unusual or unconventional reactivities under surprisingly mild reaction conditions. In such systems, photoactivated sensitizers initiate a single electron transfer from (or to) a closed-shell organic molecule to produce radical cations or radical anions whose reactivities are then exploited for interesting or unusual chemical transformations. However, the high reactivity of photoexcited substrates, intermediate radical ions or radicals, and the low activation barriers for follow-up reactions provide significant hurdles for the development of efficient catalytic photochemical processes that work under stereochemical control and provide chiral molecules in an asymmetric fashion. Here we report a highly efficient asymmetric catalyst that uses visible light for the necessary molecular activation, thereby combining asymmetric catalysis and photocatalysis. We show that a chiral iridium complex can serve as a sensitizer for photoredox catalysis and at the same time provide very effective asymmetric induction for the enantioselective alkylation of 2-acyl imidazoles. This new asymmetric photoredox catalyst, in which the metal centre simultaneously serves as the exclusive source of chirality, the catalytically active Lewis acid centre, and the photoredox centre, offers new opportunities for the 'green' synthesis of non-racemic chiral molecules. PMID:25373679

Huo, Haohua; Shen, Xiaodong; Wang, Chuanyong; Zhang, Lilu; Rse, Philipp; Chen, Liang-An; Harms, Klaus; Marsch, Michael; Hilt, Gerhard; Meggers, Eric

2014-11-01

140

A Spinel Oxynitride with Visible-Light Photocatalytic Activity  

SciTech Connect

Spinel zinc gallium oxynitride photocatalysts are prepared by the sol-gel method, at 550 C. In these materials, of base composition ZnGa{sub 2}O{sub 4} (octahedral Ga), reaction with ammonia leads to ZnGa{sub 2}O{sub x}N{sub y}, with a dramatic reduction of the bandgap to 2.7 eV, with just 1.3% N and no loss of Zn. At 850 C this phase is converted into wurzite (tetrahedral Ga). The novel oxynitrides also show visible-light photocatalytic activity towards the degradation of methylene blue.

Boppana, V.; Doren, D; Lobo, R

2010-01-01

141

Rhenium Complexes with Red-Light-Induced Anticancer Activity  

PubMed Central

Rhenium(I) pyridocarbazole complexes with photoinduced antiproliferative activity are reported. The substitutionally inert complexes induce cell death by singlet oxygen generation upon irradiation with red light (? ? 620 nm), while only weak background cytotoxicity is observed in the dark. Due to their ability to inhibit protein kinases (nanomolar IC50 values against Pim1 at 10 ?M ATP), this class of rhenium complexes point into the direction of dual function antiproliferative therapy with a single drug in which photodynamic therapy is combined with the inhibition of cancer related protein kinases. PMID:25050081

Whler, Kathrin; Ludewig, Anja; Szabo, Patrick; Harms, Klaus

2014-01-01

142

Effect of temperature and nutrients on the competition between free-floating Salvinia natans and submerged Elodea nuttallii in mesocosms  

Microsoft Academic Search

In many aquatic ecosystems, free-floating plants compete with submerged plants for nutrients and light. Being on top of the water surface free-floating plants are superior competitors for light. Submerged plants can take up nutrients from the sediment and the water column, hereby reducing these levels for free-floating plants. Global warming may change chances of successful species invasion and can alter

J. J. C. Netten; G. H. P. Arts; R. Gylstra; Nes van E. H; M. Scheffer; R. M. M. Roijackers

2010-01-01

143

Well pipe float valve  

SciTech Connect

This patent describes a drill pipe float assembly comprising an elongated cylindrical cage having upper and lower rings joined by diametrically opposite vertical wall members. The upper ring has a downwardly facing valve seat on its inner perimeter. The assembly includes a valve stem guide member supported by the lower ring including a central vertical bearing sleeve slidable guiding the depending end portion of a valve stem. The valve stem has a valve on its upper end including an elastomer seal seating and unseating on the valve seat in response to the direction of fluid flow through the ring members, cylindrical spring retainer on the valve stem in contact with the valve seal, and a helical spring surrounding the valve stem and biasing the valve toward its seat, the improvement comprising: means secured to the respective confronting end surfaces of the spring retainer and the valve stem guide sleeve for interdigitated engagement in response to fluid flow in one direction through the float assembly.

Taylor, J.S.

1986-11-18

144

Light Activated Serotonin for Exploring Its Action in Biological Systems  

PubMed Central

Summary Serotonin (5-HT) is a neuromodulator involved in regulating mood, appetite, memory, learning, pain, and establishment of left-right (LR) asymmetry in embryonic development. To explore the role of 5-HT in a variety of physiological contexts, we have created two forms of caged 5-HT, BHQ-O-5HT and BHQ-N-5HT. When exposed to 365- or 740-nm light, BHQ-O-5HT releases 5-HT through 1- or 2-photon excitation, respectively. BHQ-O-5HT mediated changes in neural activity in cultured primary sensory neurons from mouse and the trigeminal ganglion and optic tectum of intact zebrafish larvae in the form of high amplitude spiking in response to light. In Xenopus laevis embryos, 5-HT released from BHQ-O-5HT upon exposure to light increased the occurrence of LR patterning defects. Maximal rates of LR defects were observed when 5-HT was released at stage 5 compared to stage 8. These experiments show the potential for BHQ-caged serotonins in studying 5-HT-regulated physiological processes. PMID:24333002

Rea, Adam C.; Vandenberg, Laura N.; Ball, Rebecca E.; Snouffer, Ashley A.; Hudson, Alicia G.; Zhu, Yue; McLain, Duncan E.; Johnston, Lindsey L.; Lauderdale, James D.; Levin, Michael; Dore, Timothy M.

2013-01-01

145

Mechanism of activation of light-activated phosphodiesterase and evidence for homology with hormone-activated adenylate cyclase  

SciTech Connect

Light-activated cGMP phosphodiesterase (PDE) is one of the effector proteins in the rod outer segments in vertebrate retina. The hydrolysis of cGMP in rod occurs with a speed and light sensitivity which suggests a role for this hydrolysis in visual transduction. In fact, there is electrophysiological data which supports the possibility that cGMP could regulate rod membrane voltage. PDE shows very rapid activation in the presence of photons and GTP. We have called attention to the intriguing analogy between light activated rod phosphodiesterase and hormone activated adenylate cyclase. A number of studies have implicated the binding of GTP to a GTP binding protein as a factor in the hormone dependent activation of adenylate cyclase. Moreover, Cassel and Selinger have shown that hydrolysis of GTP is a component in the inactivation of the hormone dependent adenylate cyclase. We review here recent additional data which provide specific molecular details of the mechanism of light activation of rod PDE as well as demonstrate the exchange of components between light activated PDE and hormone activated cyclase.

Bitensky, M.W.; Yamazaki, A.; Wheeler, M.A.; George, J.S.; Rasenick, M.M.

1983-01-01

146

Very Large Floating Structures: Applications, Research and Development  

Microsoft Academic Search

Very large floating structures (VLFS) have attracted the attention of architects, city planners, and engineers because they provide an exciting and environmentally friendly solution for land creation from the sea as opposed to the traditional land reclamation method. The applications of VLFS as floating piers, floating hotels, floating fuel storage facilities, floating stadia, floating bridges, floating airports, and even floating

C. M. Wang; Z. Y. Tay

2011-01-01

147

How to protect privacy in floating car data systems  

Microsoft Academic Search

Floating Car Data (FCD) is a valuable source of up-to-date traffic information, with a wide range of applications. Active floating car data techniques require drivers to have their vehicles equipped with on-board units regularly transmitting position and velocity information to a central server. Many potential participants are hence reluctant to join FCD projects because of violations of their privacy due

Stefan Rass; Simone Fuchs; Martin Schaffer; Kyandoghere Kyamakya

2008-01-01

148

Addressable Micromachined UV Light Sources for Active Patterning  

Microsoft Academic Search

This paper presents a programmable UV light source array which can generate a patterned UV light for various applications. While all existing excimer lasers or UV light sources are based on a static compositional patterning, the UV light source array presented in this paper can be used to define arbitrary patterns in real-time. As a demonstration, UV light source arrays

Yoonsu Choi; Ravikanth Devireddy; Youngdo Jung; A. Bruno Frazier

2007-01-01

149

Antimicrobial properties of light-activated polyurethane containing indocyanine green.  

PubMed

The aim of this study was to produce novel antimicrobial polymers containing the light-activated antimicrobial agent indocyanine green (ICG). The novel materials were prepared by swelling polyurethane in acetone containing water and ICG, followed by solvent evaporation. The uptake of ICG was dependent upon the ratio of acetone to water. Only at a ratio of 99 parts acetone to 1 part water was there any substantial colouration of the samples. When exposed to laser light from the near infrared spectrum (808 nm), polyurethane-containing ICG exhibited antimicrobial activity against Gram-positive bacteria; a 2 log?? reduction was achieved against methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis after 15 min exposure, corresponding to an energy dose of 31.83 J delivered at an energy density of 31.83 J/cm. Under the same conditions, Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) appeared to be less susceptible, the viable count being reduced by 0.5 log??. Some of the physical properties of the resulting material were also investigated and it was found that the elasticity (Young's modulus) was reduced by approximately 60%. Furthermore, when the ICG-containing polymer was stretched, the breaking point occurred when the elongation was 6.7 times the initial value, while ICG-free polyurethane samples did not break following a 7-fold elongation. The contact angles for water droplets revealed that the ICG-containing polymer was more hydrophobic than untreated polyurethane. The results of this study show that ICG can be embedded in polyurethane to produce materials which when irradiated with near-infrared light can exert a bactericidal effect particularly against MRSA and S. epidermidis. Such materials may be useful for preparing intravenous catheters, which are often colonized by such organisms. PMID:20008087

Perni, Stefano; Pratten, Jonathan; Wilson, Michael; Piccirillo, Clara; Parkin, Ivan P; Prokopovich, Polina

2011-01-01

150

Floating Silicon Method  

SciTech Connect

The Floating Silicon Method (FSM) project at Applied Materials (formerly Varian Semiconductor Equipment Associates), has been funded, in part, by the DOE under a Photovoltaic Supply Chain and Cross Cutting Technologies grant (number DE-EE0000595) for the past four years. The original intent of the project was to develop the FSM process from concept to a commercially viable tool. This new manufacturing equipment would support the photovoltaic industry in following ways: eliminate kerf losses and the consumable costs associated with wafer sawing, allow optimal photovoltaic efficiency by producing high-quality silicon sheets, reduce the cost of assembling photovoltaic modules by creating large-area silicon cells which are free of micro-cracks, and would be a drop-in replacement in existing high efficiency cell production process thereby allowing rapid fan-out into the industry.

Kellerman, Peter

2013-12-21

151

Floating into Deep Space  

NASA Astrophysics Data System (ADS)

Is it possible for spaceflight to become more sustainable? Artist and architect Tomas Saraceno proposes a long-term artscience research project based on his initial work with solar balloons to join with the efforts of engineers such as John Powell, working on the Airship to Orbit experiments, which describe a three stage process of using airships to fly to a large suborbital "Dark Sky Station' then literally floating into orbit with additional electrical and chemical propulsion. (See: http://www.jpaerospace.com) In his artworks Toms Saraceno proposes cell-like flying cities as possible architectonic living spaces in direct reference to Buckminster Fuller's Cloud Nine (circa 1960). The fantastic architectural utopia Cloud Nine consists of a freely floating sphere measuring one mile in diameter that offers living space to several autonomous communities encompassing thousands of inhabitants each. The notion of the cloud is essential to the artist's work. The cloud as metaphor stands for artistic intention, for the meaning of territory and border in today's (urban) society, and for exploring possibilities for the sustainable development of the human living environment. In Saraceno's work this environment is not limited to the earth, but is explicitly conceived to reach into outer space. (Biomimetic Constructions- On the works of Toms Saraceno By Katharina Schlter) Saraceno is also interested in human factors experiments using his existing constructions as analogue environments for living on Mars and is proposing carry out a series of workshops, experiments and solar balloon launces in White Sands desert in early 2016 in collaboration with the curator Dr Rob La Frenais, the Rubin Center at The University of Texas at El Paso and various scientific partners.

La Frenais, R.; Saraceno, T.; Powell, J.

2014-04-01

152

Optics: Light, Color, and Their Uses. An Educator's Guide with Activities in Science and Mathematics.  

ERIC Educational Resources Information Center

This educator's guide from discusses optics, light, color and their uses. Activities include: (1) "Reflection of Light with a Plane (Flat) Mirror--Trace a Star"; (2) "Reflection of Light with Two Plane Mirrors--Double Mirrors Placed at a 90-Degree Angle"; (3) "Reflection of Light with Two Plane Mirrors--Double Mirrors Placed at a Number of

National Aeronautics and Space Administration, Huntsville, AL. George C. Marshall Space Flight Center.

153

Design of Light Pipe for an Active Target in the Blowfish Detector Array  

E-print Network

Design of Light Pipe for an Active Target in the Blowfish Detector Array Michael Barnett Jennifer of Saskatchewan August 30, 2004 1 Introduction This report outlines the development of a light pipe for an active target in the Blowfish array at the High Energy Gamma Source at Duke University. The light pipe

Saskatchewan, University of

154

Efficient blue organic light-emitting diodes employing thermally activated delayed  

E-print Network

Efficient blue organic light-emitting diodes employing thermally activated delayed fluorescence,2 * Organic light-emitting diodes (OLEDs) employing thermally activated delayed fluorescence (TADF) have energy is high enough and the 3 LE state is higher than the 3 CT state. O rganic light-emitting diodes

Cai, Long

155

Automatic planning of light source placement for an active photometric stereo system  

Microsoft Academic Search

Presents an automatic planning method of light source placement for an active photometric stereo system. Since photometric stereo systems normally use multiple light sources fixed to the environment, they cannot avoid shadows caused by surrounding objects. One remedy for this situation is to use a movable light source and to adapt its placement actively to the task environment. Candidate positions

Shigeyuki SAKANE; Tomomasa SATO; Masayoshi KAKIKURA

1990-01-01

156

Profiling floating point value ranges for reconfigurable  

E-print Network

Profiling floating point value ranges for reconfigurable implementation Ashley W Brown, Paul H J of floating-point arithmetic. This paper presents FloatWatch, a dynamic execution profiling tool designed to identify where an application can benefit from reduced precision or re- duced range in floating

Kelly, Paul H. J.

157

Interval Computations Rounding of Floating Point Intervals  

E-print Network

Interval Computations No 4, 1994 Rounding of Floating Point Intervals Marc Daumas and David W. Matula Correct rounding of the infinitely precise arithmetic as prescribed for the float- ing point #12;Rounding of Floating Point Intervals 29 1 Introduction The IEEE floating point standard has been

Kearfott, R. Baker

158

Floating--Point Fused Multiply--Add: Reduced Latency for Floating-Point Addition  

E-print Network

Floating--Point Fused Multiply--Add: Reduced Latency for Floating-Point Addition Javier D for the computation of the double--precision floating--point multiply--add fused (MAF) operation A + (B ? C) that permits to compute the floating--point addition with lower latency than floating--point multiplication

California at Davis, University of

159

L11 Floating Point 1Comp 411 Floating-Point Arithmetic  

E-print Network

L11 ­ Floating Point 1Comp 411 Floating-Point Arithmetic if ((A + A) - A == A) { SelfDestruct() } #12;L11 ­ Floating Point 2Comp 411 What is the problem? Many numeric applications require numbers over *COULD* use bigger integers Floating point is a better answer for most applications. #12;L11 ­ Floating

Bishop, Gary

160

Lighting.  

SciTech Connect

Since lighting accounts for about one-third of the energy used in commercial buildings, there is opportunity to conserve. There are two ways to reduce lighting energy use: modify lighting systems so that they used less electricity and/or reduce the number of hours the lights are used. This booklet presents a number of ways to do both. Topics covered include: reassessing lighting levels, reducing lighting levels, increasing bulb & fixture efficiency, using controls to regulate lighting, and taking advantage of daylight.

United States. Bonneville Power Administration.

1992-09-01

161

A novel control process of cyanobacterial bloom using cyanobacteriolytic bacteria immobilized in floating biodegradable plastic carriers.  

PubMed

A process using a floating carrier for immobilization of cyanobacteriolytic bacteria, B.cereus N-14, was proposed to realize an effective in situ control of natural floating cyanobacterial blooms. The critical concentrations of the cyanobacteriolytic substance and B.cereus N-14 cells required to exhibit cyanobacteriolytic activity were investigated. The results indicated the necessity of cell growth to produce sufficiently high amounts of the cyanobacteriolytic substance to exhibit its activity and also for conditions enabling good contact between high concentrations of the cyanobacteriolytic substance and cyanobacteria. Floating biodegradable plastics made of starch were applied as a carrier material to maintain close contact between the immobilized cyanobacteriolytic bacteria and floating cyanobacteria. The floating starch-carriers could eliminate 99% of floating cyanobacteria in 4 d. Since B.cereus N-14 could produce the cyanobacteriolytic substance under the presence of starch and some amino acids, the cyanobacteriolytic activity could be attributed to carbon source fed from starch carrier and amino acids eluted from lysed cyanobacteria. Therefore, the effect of using a floating starch-carrier was confirmed from both view points as a carrier for immobilization and a nutrient source to stimulate cyanobacteriolytic activity. The new concept to apply a floating carrier immobilizing useful microorganisms for intensive treatment of a nuisance floating target was demonstrated. PMID:14977153

Nakamura, N; Nakano, K; Sugiura, N; Matsumura, M

2003-12-01

162

Light-activated heterotrophic growth of the cyanobacterium Synechocystis sp. strain PCC 6803: a blue-light-requiring process.  

PubMed Central

A glucose-tolerant strain of Synechocystis sp. strain 6803 will not grow on glucose under complete darkness unless given a daily pulse of white light, typically 5 min of 40 mumol m-2 s-1 (light-pulsed conditions). The light pulse is insufficient for photoautotrophy, as glucose is required and growth yield is dependent on glucose concentration. Growth rate is independent of fluence, but growth yield is dependent on fluence, saturating at 40 to 75 mumol m-2 s-1. A Synechocystis strain 6803 psbA mutant strain grows under light-pulsed conditions at rates similar to those for the glucose-tolerant strain, indicating that photosystem II is not required for growth. The relative spectral sensitivity of the growth of light-pulsed cultures (growth only in blue light, 400 to 500 nm, maximum at 450 nm) precludes energetic contribution from cyclic electron transport around photosystem I. Pulses of long-wavelength light (i.e., 550 and 650 nm) did not support the growth of Synechocystis strain 6803 and, when supplied before or after a blue-light pulse, did not inhibit blue-light-stimulated growth of Synechocystis strain 6803. We conclude that the required blue-light pulse does not support growth via photosynthetic electron transport but appears instead to function as an environmental signal regulating heterotrophic metabolism, cell division, or other photomorphogenic processes. We have termed the growth of Synechocystis strain 6803 pulsed with light and kept otherwise in complete darkness light-activated heterotrophic growth. This observation of a blue-light requirement for the growth of Synechocystis strain 6803 represents a novel blue light effect on the growth of a cyanobacterium. PMID:1902208

Anderson, S L; McIntosh, L

1991-01-01

163

NULL Convention Floating Point Multiplier  

PubMed Central

Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to perform floating point multiplication. The proposed multiplier offers substantial decrease in power consumption when compared with its synchronous version. Performance attributes of the NULL convention logic floating point multiplier, obtained from Xilinx simulation and Cadence, are compared with its equivalent synchronous implementation. PMID:25879069

Ramachandran, Seshasayanan

2015-01-01

164

Floating orbital molecular dynamics simulations.  

PubMed

We introduce an alternative ab initio molecular dynamics simulation as a unification of Hartree-Fock molecular dynamics and the floating orbital approach. The general scheme of the floating orbital molecular dynamics method is presented. Moreover, a simple but sophisticated guess for the orbital centers is provided to reduce the number of electronic structure optimization steps at each molecular dynamics step. The conservation of total energy and angular momentum is investigated in order to validate the floating orbital molecular dynamics approach with and without application of the initial guess. Finally, a water monomer and a water dimer are simulated, and the influence of the orbital floating on certain properties like the dipole moment is investigated. PMID:24600690

Perlt, Eva; Brssel, Marc; Kirchner, Barbara

2014-04-21

165

Control development for floating wind  

NASA Astrophysics Data System (ADS)

Control of a floating wind turbine has proven to be challenging, but essential for lowering the cost of floating wind energy. Topic of a recent joint R&D project by GustoMSC, MARIN and ECN, is the concept design and verification with coupled simulations and model tests of the GustoMSC Tri-Floater. Only using an integral design approach, including mooring and control design, a cost effective system can be obtained. In this project, ECN developed a general floating wind turbine control strategy and applied this in a case study to the GustoMSC Tri-Floater and the OC3Hywind spar, both equipped with the NREL 5MW RWT. The designed controller ensures stable operation, while maintaining proper speed and power regulation. The motions of the floating support are reduced and substantial load reduction has been achieved.

Savenije, Feike; Peeringa, Johan

2014-06-01

166

Organic molecular floating gate memories  

E-print Network

Flash memory devices dominate the non-volatile memory market, with device structures that utilize charge storage in polysilicon floating gates imbedded in insulating silicon oxide films'. As demands for high storage density, ...

Paydavosi, Sarah

2011-01-01

167

Electrically floating, near vertical incidence, skywave antenna  

DOEpatents

An Electrically Floating, Near Vertical Incidence, Skywave (NVIS) Antenna comprising an antenna element, a floating ground element, and a grounding element. At least part of said floating ground element is positioned between said antenna element and said grounding element. The antenna is separated from the floating ground element and the grounding element by one or more electrical insulators. The floating ground element is separated from said antenna and said grounding element by one or more electrical insulators.

Anderson, Allen A.; Kaser, Timothy G.; Tremblay, Paul A.; Mays, Belva L.

2014-07-08

168

Tests find hammering, fluid cutting, erosion cause float shoe failures  

Microsoft Academic Search

The results of a systematic test program to evaluate float equipment performance are presented. The testing has destroyed, over an eightmonth period, 160 float valves, float shoes and float collars. A new float valve design with greater resistance to failure has been developed as a result of the testing. New float collars and float shoes are expected to provide the

Stringfellow

1985-01-01

169

Skylab floating ice experiment  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. Coupling of the aircraft data with the ground truth observations proved to be highly successful with interesting results being obtained with IR and SLAR passive microwave techniques, and standard photography. Of particular interest were the results of the PMIS system which operated at 10.69 GHz with both vertical and horizontal polarizations. This was the first time that dual polarized images were obtained from floating ice. In both sea and lake ice, it was possible to distinguish a wide variety of thin ice types because of their large differences in brightness temperatures. It was found that the higher brightness temperature was invariably obtained in the vertically polarized mode, and as the age of the ice increases the brightness temperature increases in both polarizations. Associated with this change in age, the difference in temperature was observed as the different polarizations decreased. It appears that the horizontally polarized data is the most sensitive to variations in ice type for both fresh water and sea ice. The study also showed the great amount of information on ice surface roughness and deformation patterns that can be obtained from X-band SLAR observations.

Campbell, W. J. (principal investigator); Ramseier, R. O.; Weaver, R. J.; Weeks, W. F.

1975-01-01

170

Floating intake reduces pump damage  

SciTech Connect

The solution to a costly sand erosion problem at the Grande Dixence hydroelectric project in Switzerland turned out to be as simple as a floating pump. The 726-MW Grande Dixence project drains a 350-square-kilometer reach of the Zermatt and Herens valleys in the southwestern Swiss Alps. About half of the drainage area is covered by active glaciers. Because the glaciers in Zermatt Valley are so low in altitude, their water is collected in Z`mutt Reservoir at the base of the Matterhorn, then pumped up 500 meters for transport to the main Grande Disence Reservoir near Sion. The glacier water is heavily laden with sand. In spite of a gravel pass and a desilter, the 700,000-acubic-meter Z`mutt Reservoir receives large quantities of sand. The sand tends to remain in solution because of the low water temperatures (1 to 2 degrees Centigrade). In the original intake system, the sand would be sucked into the pump intakes, causing extensive erosion to the pump wheels and an expensive yearly program of repair. (Pump damage averaged 200,000 Swiss Francs ($284,000 U.S.) per year between 1980 and 1985.)

Kronig, A.

1993-12-31

171

Light  

NSDL National Science Digital Library

Have you ever wondered how light works? Today, you will be light detectives investigating how light works! Follow the links below to help your investigation! As you are reading about light, write down any words that you do not know. Use the dictionary link to find definitions. Write down their definitions as you find them. First, you will need to know some Light Basics Find out more about light with Light Fun Facts Want to know how glasses help people see? Go to Light and Lenses Look up any unknown words atWebster s Word Central ...

Miss Massey

2009-03-15

172

Exogenous control of diel locomotor activity in the whitefish Coregonus clupeaformis: effects of light and temperature  

Microsoft Academic Search

Data on factors determining activity cycles of nearctic fishes are scarce overall, and nonexistent for Coregoniae (family Salmonidae), a group with closely related and somewhat better known palaearctic species. We studied effects of photoperiodicity, light intensity and temperature on diel locomotor activity of lake whitefish Coregonus clupeaformis (Mitchill). Under LD 12:12, a day-active pattern was evident. Under continuous light (LL)

E. Scherer; S. E. Harrison

1988-01-01

173

Advanced Light Source activity report 1996/97  

SciTech Connect

Ten years ago, the Advanced Light Source (ALS) existed as a set of drawings, calculations, and ideas. Four years ago, it stored an electron beam for the first time. Today, the ALS has moved from those ideas and beginnings to a robust, third-generation synchrotron user facility, with eighteen beam lines in use, many more in planning or construction phases, and hundreds of users from around the world. Progress from concepts to realities is continuous as the scientific program, already strong in many diverse areas, moves in new directions to meet the needs of researchers into the next century. ALS staff members who develop and maintain the infrastructure for this research are similarly unwilling to rest on their laurels. As a result, the quality of the photon beams the authors deliver, as well as the support they provide to users, continues to improve. The ALS Activity Report is designed to share the results of these efforts in an accessible form for a broad audience. The Scientific Program section, while not comprehensive, shares the breadth, variety, and interest of recent research at the ALS. (The Compendium of User Abstracts and Technical Reports provides a more comprehensive and more technical view.) The Facility Report highlights progress in operations, ongoing accelerator research and development, and beamline instrumentation efforts. Although these Activity Report sections are separate, in practice the achievements of staff and users at the ALS are inseparable. User-staff collaboration is essential as they strive to meet the needs of the user community and to continue the ALS's success as a premier research facility.

NONE

1997-09-01

174

Light stimulus change evokes an activity response in the rat  

Microsoft Academic Search

Bright light may be a danger signal for rats because they are more vulnerable to predators in bright environments. We examined\\u000a the fear-evoking properties of bright light with a novel open-field procedure that confronts a rat with the sudden onset or\\u000a termination of a bright light gradient. The rats did not freeze but exhibited a transient increase in locomotion to

Bill P. Godsil; Michael S. Fanselow

2004-01-01

175

Engineering of a red-lightactivated human cAMP/cGMP-specific phosphodiesterase  

PubMed Central

Sensory photoreceptors elicit vital physiological adaptations in response to incident light. As light-regulated actuators, photoreceptors underpin optogenetics, which denotes the noninvasive, reversible, and spatiotemporally precise perturbation by light of living cells and organisms. Of particular versatility, naturally occurring photoactivated adenylate cyclases promote the synthesis of the second messenger cAMP under blue light. Here, we have engineered a light-activated phosphodiesterase (LAPD) with complementary light sensitivity and catalytic activity by recombining the photosensor module of Deinococcus radiodurans bacterial phytochrome with the effector module of Homo sapiens phosphodiesterase 2A. Upon red-light absorption, LAPD up-regulates hydrolysis of cAMP and cGMP by up to sixfold, whereas far-red light can be used to down-regulate activity. LAPD also mediates light-activated cAMP and cGMP hydrolysis in eukaryotic cell cultures and in zebrafish embryos; crucially, the biliverdin chromophore of LAPD is available endogenously and does not need to be provided exogenously. LAPD thus establishes a new optogenetic modality that permits light control over diverse cAMP/cGMP-mediated physiological processes. Because red light penetrates tissue more deeply than light of shorter wavelengths, LAPD appears particularly attractive for studies in living organisms. PMID:24889611

Gasser, Carlos; Taiber, Sandra; Yeh, Chen-Min; Wittig, Charlotte Helene; Hegemann, Peter; Ryu, Soojin; Wunder, Frank; Mglich, Andreas

2014-01-01

176

Active Matrix Organic Light Emitting Diode (AMOLED) Environmental Test Report  

NASA Technical Reports Server (NTRS)

This report focuses on the limited environmental testing of the AMOLED display performed as an engineering evaluation by The NASA Johnson Space Center (JSC)-specifically. EMI. Thermal Vac, and radiation tests. The AMOLED display is an active-matrix Organic Light Emitting Diode (OLED) technology. The testing provided an initial understanding of the technology and its suitability for space applications. Relative to light emitting diode (LED) displays or liquid crystal displays (LCDs), AMOLED displays provide a superior viewing experience even though they are much lighter and smaller, produce higher contrast ratio and richer colors, and require less power to operate than LCDs. However, AMOLED technology has not been demonstrated in a space environment. Therefore, some risks with the technology must be addressed before they can be seriously considered for human spaceflight. The environmental tests provided preliminary performance data on the ability of the display technology to handle some of the simulated induced space/spacecraft environments that an AMOLED display will see during a spacecraft certification test program. This engineering evaluation is part of a Space Act Agreement (SM) between The NASA/JSC and Honeywell International (HI) as a collaborative effort to evaluate the potential use of AMOLED technology for future human spaceflight missions- both government-led and commercial. Under this SM, HI is responsible for doing optical performance evaluation, as well as temperature and touch screen studies. The NASA/JSC is responsible for performing environmental testing comprised of EMI, Thermal Vac, and radiation tests. Additionally, as part of the testing, limited optical data was acquired to assess performance as the display was subjected to the induced environments. The NASA will benefit from this engineering evaluation by understanding AMOLED suitability for future use in space as well as becoming a smarter buyer (or developer) of the technology. HI benefits from the environmental testing results by understanding its performance limitations/shortcomings to improve subsequent generations of AMOLED technology. Note that the AMOLED used in this test was not deSigned for the space environment but rather for commercial/industrial terrestrial applications.

Salazar, George A.

2013-01-01

177

Planet signatures in collisionally active debris discs: scattered light images  

NASA Astrophysics Data System (ADS)

Context. Planet perturbations have been often invoked as a potential explanation for many spatial structures that have been imaged in debris discs. So far this issue has been mostly investigated with pure N-body numerical models, which neglect the crucial effect collisions within the disc can have on the disc's response to dynamical perturbations. Aims: We numerically investigate how the coupled effect of collisions and radiation pressure can affect the formation and survival of radial and azimutal structures in a disc perturbed by a planet. We consider two different set-ups: a planet embedded within an extended disc and a planet exterior to an inner debris ring. One important issue we want to address is under which conditions a planet's signature can be observable in a collisionally active disc. Methods: We use our DyCoSS code, which is designed to investigate the structure of perturbed debris discs at dynamical and collisional steady-state, and derive synthetic images of the system in scattered light. The planet's mass and orbit, as well as the disc's collisional activity (parameterized by its average vertical optical depth ?0) are explored as free parameters. Results: We find that collisions always significantly damp planet-induced spatial structures. For the case of an embedded planet, the planet's signature, mostly a density gap around its radial position, should remain detectable in head-on images if Mplanet ? MSaturn. If the system is seen edge-on, however, inferring the presence of the planet is much more difficult, as only weak asymmetries remain in a collisionally active disc, although some planet-induced signatures might be observable under very favourable conditions. For the case of an inner ring and an external planet, planetary perturbations cannot prevent collision-produced small fragments from populating the regions beyond the ring. The radial luminosity profile exterior to the ring is in most cases close to the one it should have in the absence of the external planet. The most significant signature left by a Jovian planet on a circular orbit are precessing azimutal structures that can be used to indirectly infer its presence. For a planet on an eccentric orbit, we show that the ring becomes elliptic and that the well known pericentre glow effect is visible despite of collisions and radiation pressure, but that detecting such features in observed discs is not an unambiguous indicator of the presence of an outer planet. Movies are available in electronic form at http://www.aanda.org

Thebault, P.; Kral, Q.; Ertel, S.

2012-11-01

178

UV light induced plasticization and light activated shape memory of spiropyran doped ethylene-vinyl acetate copolymers.  

PubMed

Light activated shape memory polymers (LASMPs) are relatively new kinds of smart materials and have significant technological applications ranging from biomedical devices to aerospace technology. EVA films doped with spiropyran with contents ranging from 0.1% to 3% show efficient UV activated shape memory behaviors if the fixed shape deformation is limited within 80%. For EVA films containing 3% spiropyran, UV irradiation causes a decrease in EVA modulus of about 44%. FT-IR and solid (13)C NMR in association with UV-vis absorption analysis demonstrate that UV irradiation transforms spiropyran from the SP form to the MC form, meanwhile, it induces an increase in the molecular mobility in the amorphous phase of EVA. Thus, the spiropyran-doped EVA films act as LASMPs via a mechanism of light induced plasticization. Light activated spiropyran acts as a plasticizer to EVA. PMID:24686814

Zhang, Xianzhe; Zhou, Qingqing; Liu, Huarong; Liu, Hewen

2014-06-01

179

Color-Encoded Structured Light for Rapid Active Ranging  

Microsoft Academic Search

In this paper, we discuss a novel strategy for rapid acquisition of the range map of a scene employing color-encoded structured light. This technique offers several potential advantages including increased speed and improved accuracy. In this approach we illuminate the scene with a single encoded grid of colored light stripes. The indexing problem, that of matching a detected image plane

Kim L. Boyer; Avinash C. Kak

1987-01-01

180

Tried and True: Whatever floats your boat  

NSDL National Science Digital Library

Ever since Archimedes ran down the streets of ancient Greece shouting, "Eureka!," scientists have understood that a submerged body displaces a volume of water equalto its own volume. Scientists also came to realize that if a body weighed less than the water it displaced, the body would float. Although this knowledge has been aroundfor nearly 2,500 years, many students still have difficulty explaining how a vessel made of a heavier-than-water material, such as steel, remains afloat. The following triedand true activity provides students with a hands-on experience that explains the principle of buoyancy.

Susan L. McBride

2003-03-01

181

Blue light activates calcium-permeable channels in Arabidopsis mesophyll cells via the phototropin signaling pathway  

Microsoft Academic Search

Light is a central regulator of plant growth and development. Among the processes triggered by blue and UV-A light, phototropism, stomatal movement, and chloroplast orientation rely on the activation of blue-light receptors known as phototropins. So far, these photoreceptors constitute a class of light receptor kinases unique to the plant kingdom. In Arabidopsis thaliana, the two members phot1 and phot2

Sonja Stoelzle; Takatoshi Kagawa; Masamitsu Wada; Rainer Hedrich; Petra Dietrich

2003-01-01

182

Floating units cut production costs  

SciTech Connect

Nine operating semisubmersible and tanker production platform facilities are currently supplying the technology and experiential data necessary for development of floating production systems for depth applications of 1000 to 10,000 ft. Sedco-Hamilton Production Services has developed a 4-well deepwater system consisting of a floating tanker or semi moored on short lines to 4 permanent catenary moored springbuoys. The platform is linked to a seabed tree array through the hull centerline via a flexible, retrievable production riser bundle. Costs associated with floating production platforms normally are lower than those of fixed platforms. A major factor is the decision to convert an existing drilling rig into the production mode or alternatively opt for a new build.

Homer, A.

1983-05-01

183

Light/dark modulation of enzyme activity in developing barley leaves  

SciTech Connect

Light/dark modulation of the ribulose-5-phosphate kinase, NADP{sup +}-glyceraldehyde-3-phosphate dehydrogenase, and fructose-1,6-bisphosphatase activity was measured in the developing primary leaf of barley (Hordeum vulgare L.) seedlings. Ribulose-5-phosphate kinase and NADP{sup +}-glyceraldehyde-3-phosphate dehydrogenase were fully light activated even at the earliest developmental stage sampled. In contrast, light modulation of fructose-1,6-bisphosphatase exhibited a complex response to leaf developmental status. Light stimulation of fructose-1,6-bisphosphatase activity (measured at pH 8.0) increased progressively during leaf development. On the other hand, acid fructose-1,6-bisphosphatase activity (measured at pH 6.0) was inhibited by light, and this light inhibition was greater in the base of the leaf than in the tip of the leaf.

Sibley, M.H.; Anderson, L.E. (Univ. of Illinois, Chicago (USA))

1989-12-01

184

14 CFR 29.521 - Float landing conditions.  

Code of Federal Regulations, 2013 CFR

...Requirements Water Loads 29.521 Float landing conditions. If certification for float operation (including float amphibian operation) is requested, the rotorcraft, with floats, must be designed to withstand the following loading...

2013-01-01

185

14 CFR 29.521 - Float landing conditions.  

Code of Federal Regulations, 2012 CFR

...Requirements Water Loads 29.521 Float landing conditions. If certification for float operation (including float amphibian operation) is requested, the rotorcraft, with floats, must be designed to withstand the following loading...

2012-01-01

186

14 CFR 29.521 - Float landing conditions.  

Code of Federal Regulations, 2010 CFR

...Requirements Water Loads 29.521 Float landing conditions. If certification for float operation (including float amphibian operation) is requested, the rotorcraft, with floats, must be designed to withstand the following loading...

2010-01-01

187

14 CFR 29.521 - Float landing conditions.  

Code of Federal Regulations, 2014 CFR

...Requirements Water Loads 29.521 Float landing conditions. If certification for float operation (including float amphibian operation) is requested, the rotorcraft, with floats, must be designed to withstand the following loading...

2014-01-01

188

14 CFR 29.521 - Float landing conditions.  

Code of Federal Regulations, 2011 CFR

...Requirements Water Loads 29.521 Float landing conditions. If certification for float operation (including float amphibian operation) is requested, the rotorcraft, with floats, must be designed to withstand the following loading...

2011-01-01

189

Lighting  

NSDL National Science Digital Library

Lighting is one of the key elements used in cinematography. This unit will demonstrate the basic concepts and theory behind lighting which you will use in your future video projects. State Standard 3 - The student will be able to understand and demonstrate lighting systems and how they are used. Objective - At the conclusion of this unit you be able to demonstrate a three-point lighting setup. You will also be able to define each of the following terms and ...

Mr. Scholer

2009-09-21

190

How Active are Rural Children and Adolescents During PE Class? An Examination of Light Physical Activity  

PubMed Central

BACKGROUND Few studies have examined non-exercise activity thermogenesis (NEAT) or light physical activity among a group of rural youth, particularly during physical education (PE) class. The purpose of this study was to determine whether the percent of PE class time spent in NEAT is related to school level (elementary versus high school) in a group of rural youth. METHODS Accelerometer data from 357 students (192 elementary, 165 high school) were included in the analysis. Mixed model linear regression was performed to examine the effect of school level on the percent of PE class time spent in NEAT. Covariates included gender, PE teacher, and the duration of the PE class. RESULTS School level was a significant predictor of the percent of PE class time spent in NEAT. Specifically, elementary school students spent more of their PE class time in NEAT than high school students (p< .001). No other significant predictors were identified. CONCLUSIONS The results of this study suggest an association between lower levels of light (NEAT) physical activity among high school versus elementary school students during PE class. PMID:24902465

Matthews-Ewald, Molly R.; Kelley, George A.; Moore, Lucas C.; Gurka, Matthew J.

2015-01-01

191

Inverse differential casing cementing float valve  

SciTech Connect

This patent describes an inverse differential fill-up casing cementing float valve having an inlet thereto and outlet therefrom characterized in that the float valve permits fluid flow therethrough in a first direction upon a predetermined fluid pressure level thereacross and continuously prevents fluid flow therethrough in a second direction. The float valve includes: an annular float valve housing; a back pressure valve assembly contained within the annular float valve housing; a first differential pressure check valve assembly connected to the back pressure valve assembly and contained within the annular float valve housing; a second differential pressure check valve assembly connected to the first differential pressure check valve assembly and contained within the annular float valve housing; and cementitious filter material retaining and securing the back pressure valve assembly, the first differential pressure check valve assembly and the second differential pressure check valve assembly within the annular float valve housing.

Kuhlman, R.D. Jr.

1986-10-07

192

Floats, Integers, and Single Source Shortest Paths  

Microsoft Academic Search

Floats are ugly, but to everyone but theoretical computer scientists, they are the real thing. A linear time algorithm is presented for the undirected single-source shortest paths problem with nonnegative floating point weights.

Mikkel Thorup

2000-01-01

193

Gibberellins negatively regulate light-induced nitrate reductase activity in Arabidopsis seedlings.  

PubMed

In the present study, the role of phytohormone gibberellins (GAs) on regulating the nitrate reductase (NR) activity was tested in Arabidopsis seedlings. The NR activity in light-grown Col-0 seedlings was reduced by exogenous GA? (an active form of GAs), but enhanced by exogenous paclobutrazol (PAC, a gibberellin biosynthesis inhibitor), suggesting that GAs negatively regulate the NR activity in light-grown seedlings. Light is known to influence the NR activity through both photosynthesis and phytochromes. When etiolated seedlings were transferred to white or red light, both exogenously applied GA? and PAC were found to function on the NR activity only in the presence of sucrose, implying that GAs are not involved in light signaling-induced but negatively regulate photoproducts-induced NR activity. NR is regulated by light mainly at two levels: transcript level and post-translational level. Our reverse transcription (RT)-PCR assays showed that GAs did not affect the transcript levels of NIA1 and NIA2, two genes that encode NR proteins. But the divalent cations (especially Mg?) were required for GAs negative regulation of NR activity, in view of the importance of divalent cations during the process of post-translational regulation of NR activity, which indicates that GAs very likely regulate the NR activity at the post-translational level. In the following dark-light shift analyses, GAs were found to accelerate dark-induced decrease, but retard light-induced increase of the NR activity. Furthermore, it was observed that application of G? or PAC could impair diurnal variation of the NR activity. These results collectively indicate that GAs play a negative role during light regulation of NR activity in nature. PMID:21856037

Zhang, Yongqiang; Liu, Zhongjuan; Liu, Rongzhi; Wang, Liguang; Bi, Yurong

2011-12-15

194

Tapered Floating Point: A New Floating-Point Representation  

Microsoft Academic Search

It is well known that there is a possible tradeoff in the binary representation of floating-point numbers in which one bit of accuracy can be gained at the cost of halving the exponent range, and vice versa. A way in which the exponent range can be greatly increased while preserving full accuracy for most computations is suggested.

ROBERT MORRIS

1971-01-01

195

Why do countries float the way they float?  

Microsoft Academic Search

Countries that are classified as having floating exchange rate systems (or very wide bands) show strikingly different patterns of behavior. They hold very different levels of international reserves and allow very different volatilities to the movements of the exchange rate relative to the volatility that they tolerate either on the level of reserves or on interest rates. We document these

Ricardo Hausmann; Ugo Panizza; Ernesto Stein

2001-01-01

196

Why Do Countries Float the Way They Float?  

Microsoft Academic Search

Countries that are classified as having floating exchange rate systems (or very wide bands) show strikingly different patterns of behavior. They hold very different levels of international reserves and allow very different volatilities in the movements of the exchange rate relative to the volatility that they tolerate either on the level of reserves or in interest rates. We document these

Ricardo Hausmann; Ugo G. Panizza; Ernesto Hugo Stein

2000-01-01

197

Implementation of float-float operators on graphics hardware  

Microsoft Academic Search

The Graphic Processing Unit (GPU) has evolved into a powerful and flexible processor. The latest graphic processors provide fully programmable vertex and pixel processing units that support vector operations up to single floating-point precision. This computational power is now being used for general-purpose computations. However, some applications require higher precision than single precision. This paper describes the emulation of a

Guillaume Da Graa; David Defour

2006-01-01

198

Attenuation of flexural vibration for floating floor and floating box induced by ground vibration  

Microsoft Academic Search

This paper investigates the vibration isolation performance of floating floor and floating box structures to control rail vibration transmission. Simple theoretical and experimental methods are developed to analyze the effects of stiffener beam, mass and arrangement of isolator on the fundamental natural frequency of the flexural vibration of floating floor and box structure.The vibration reduction performances of floating floor and

C. K. Hui; C. F. Ng

2009-01-01

199

40 CFR 65.45 - External floating roof converted into an internal floating roof.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false External floating roof converted into an internal floating roof. 65.45 Section 65.45 Protection...RULE Storage Vessels 65.45 External floating roof converted into an internal floating...

2014-07-01

200

Study on Influence of the Floating Ring in Floating Ring Bearing System under Turbulence State  

Microsoft Academic Search

The mechanism of a floating ring in the floating ring bearing system is investigated. Based on Hirs' bulk flow theory, Moody's frication factor equation and generalized incompressible Reynolds Equation, considering the elastic deformation and the whirling motion of the floating ring, the model and the governing equation of the floating ring bearing under the turbulence state were set up. The

Zhaohui Kang; Xingmin Ren; Zhi Wang; Shangwen He

2010-01-01

201

FloatOmeter: User-Friendly Input of Floating-Point Numbers in Virtual Environments  

E-print Network

FloatOmeter: User-Friendly Input of Floating-Point Numbers in Virtual Environments Matthias Kreiser, RI 02912 USA {kreiser,schulze,asf}@cs.brown.edu Specifying floating-point numbers in immersive. The most commonly used way to input floating-point numbers is by sliders. Sliders are widgets with a button

Schulze, Jürgen P.

202

CS61C Fall 2011 Floating Point and CALL -Notes modified from Fall 2010 Floating Point  

E-print Network

CS61C Fall 2011 Floating Point and CALL - Notes modified from Fall 2010 Floating Point /* 100 thousand */ #define INCREMENT .00003f /* 3 hundred thousandths */ int main(void) { int i; float x = 0.f; for (i = 0; i float result = (x - 3.f)/3.f; printf

California at Irvine, University of

203

Wave attenuation characteristics of a tethered float system  

Microsoft Academic Search

Wave attenuation characteristics of a tethered float system have been investigated for various wave heights, wave periods, water depths, depths of submergence of floats and float sizes. As the floats are similar in size and shape, only a single tethered spherical float is considered for the theoretical analysis. Float motion is determined through the dynamical equation of motion, developed for

P. Vethamony

1995-01-01

204

32 CFR 935.165 - Floating objects.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Floating objects. 935.165 Section 935...CODE Public Safety 935.165 Floating objects. No person may anchor, moor, or beach any boat, barge, or other floating object on Wake Island in any location...

2014-07-01

205

Floating Content: Information Sharing in Urban Areas  

E-print Network

Floating Content: Information Sharing in Urban Areas J¨org Ott, Esa Hyyti¨a, Pasi Lassila Aalto. The net result is a best effort service for floating content in which: 1) information dissemination for floating content, which, at the same time also validate the analytical results obtained for a more abstract

Ott, Jörg

206

Multiplications of floating point expansions Marc Daumas  

E-print Network

Multiplications of floating point expansions Marc Daumas CNRS - Lab LIP - UMR 8512 - ENS de Lyon computers, the floating point unit is the part of the processor delivering the highest computing power will be dramatically enhanced by adequate use of floating point expansions. We present in this work three

California at Davis, University of

207

Optimistic Parallelization of Floating-Point Accumulation  

E-print Network

Optimistic Parallelization of Floating-Point Accumulation Nachiket Kapre Computer Science and Systems Engineering University of Pennsylvania Philadelphia, PA 19104 andre@acm.org Abstract-- Floating intermediate values be rounded to fit in the available precision. The resulting cyclic dependency in floating

California at Davis, University of

208

Compensated algorithms in floating point arithmetic  

E-print Network

Compensated algorithms in floating point arithmetic: accuracy, validation, performances. Nicolas ´Equipe DALI N. Louvet (Universit´e de Perpignan) Nicolas Louvet ­ Compensated algorithms in floating of errors when computing the solution of a scientific problem in floating point arithmetic: mathematical

Louvet, Nicolas

209

Floating-Point Arithmetic Precision and Accuracy  

E-print Network

Floating-Point Arithmetic Precision and Accuracy With Mathematica Alkis Akritas University is to approximate the real numbers using the finite set of floating-point numbers. Mathematica has two kinds of floating-point numbers: machine- precision numbers and arbitrary-precision numbers. (The precision

Akritas, Alkiviadis G.

210

Floating Content: Information Availability in Urban Environments  

E-print Network

Floating Content: Information Availability in Urban Environments Jussi Kangasharju University networking. The net result is a best effort service for floating content in which: 1) information be added, but not deleted. We present the general model for floating content and results from our on

Ott, Jörg

211

Accurate floating point summation James Demmel  

E-print Network

Accurate floating point summation James Demmel Yozo Hida May 8, 2002 Abstract We present and analyze several simple algorithms for accurately summing n floating point numbers S = n i=1 si precision only (F 2f). We apply this result to the floating point formats in the (proposed revision of the

California at Berkeley, University of

212

Initial stages of float glass corrosion  

Microsoft Academic Search

The differences between the corrosion process of the bath and the top side of float glass and the dependence on the corrosion process on the thickness of the glass could be demonstrated by ellipsometric measurements of defined corroded float glasses. The effectiveness of different cleaning procedures on corroded float glass surfaces is discussed. Ellipsometry can help determine suitable separating agent

M. Feldmann; R. Wei?mann

1997-01-01

213

Floating Point Numbers Review of Numbers  

E-print Network

Floating Point Numbers #12;2 Review of Numbers Computers are made to deal with numbers What can we notation #12;3 Scientific Notation: Review 6.02 x 1023 radix (base)decimal point mantissa exponent Declare such variable in C as float #12;5 Floating Point (FP) Representation (1/2) Normal format: +1

Delgado-Frias, Jos G.

214

The fluid mechanics of floating and sinking  

E-print Network

objects can float at an interface between two fluids. We obtain the conditions on density and size for various objects to float and show that being super-hydrophobic does not generally help small, dense objects to float. Super-hydrophobicity does...

Vella, Dominic Joseph Robert

2007-10-02

215

Have Floating Rates Been a Success?  

ERIC Educational Resources Information Center

Floating exchange rates have not lived up to all expectations, but neither have they performed as badly as some critics have suggested. Examined are the impact of floating rates on balance of payments adjustment, domestic economic policy, and inflation and the claim that floating rates have displayed excessive fluctuations. (Author/RM)

Higham, David

1983-01-01

216

Floats, Integers, and Single Source Shortest Paths  

Microsoft Academic Search

Floats are ugly, but to everyone but theoretical computer scientists, they are thereal thing. A linear time algorithm is presented for the undirected single source shortestpaths problem with positive floating point weights.1 IntroductionThe technical goal of this paper is to present a linear time solution to the undirected singlesource shortest paths problem (USSSP) where the weights are positive floating points,

Mikkel Thorup

1998-01-01

217

The coolest 'stars' are free-floating planets  

E-print Network

We show that the coolest known object that is probably formed in a star-like mode is a free-floating planet. We discovered recently that the free-floating planetary mass object OTS,44 (M9.5, ~12 Jupiter masses, age ~2 Myr) has significant accretion and a substantial disk. This demonstrates that the processes that characterize the canonical star-like mode of formation apply to isolated objects down to a few Jupiter masses. We detected in VLT/SINFONI spectra that OTS44 has strong, broad, and variable Paschen beta emission. This is the first evidence for active accretion of a free-floating planet. The object allows us to study accretion and disk physics at the extreme and can be seen as free-floating analog of accreting planets that orbit stars. Our analysis of OTS44 shows that the mass-accretion rate decreases continuously from stars of several solar masses down to free-floating planets. We determined, furthermore, the disk mass (10 Earth masses) and further disk properties of OTS44 through modeling its SED inc...

Joergens, V; Liu, Y; Bayo, A; Wolf, S

2014-01-01

218

A Variable Light Domain Fluorogen Activating Protein Homodimerizes to Activate Dimethylindole Red  

PubMed Central

Novel fluorescent tools such as green fluorescent protein analogs and Fluorogen Activating Proteins (FAPs) are useful in biological imaging to track protein dynamics in real-time with low fluorescence background. FAPs are single-chain variable fragments (scFvs) selected from a yeast surface display library that produce fluorescence upon binding a specific dye or fluorogen that is normally not fluorescent when present in solution. FAPs generally consist of human immunoglobulin variable heavy (VH) and variable light (VL) domains covalently attached via a glycine and serine rich linker. Previously, we determined that the yeast surface clone, VH-VL M8, could bind and activate the fluorogen dimethylindole red (DIR), but that the fluorogen activation properties were localized to the M8VL domain. We report here that both NMR and X-ray diffraction methods indicate the M8VL forms non-covalent, anti-parallel homodimers that are the fluorogen activating species. The M8VL homodimers activate DIR by restriction of internal rotation of the bound dye. These structural results, together with directed evolution experiments of both VH-VL M8 and M8VL, led us to rationally design tandem, covalent homodimers of M8VL domains joined by a flexible linker that have a high affinity for DIR and good quantum yield. PMID:22390683

Senutovitch, Nina; Stanfield, Robyn L.; Bhattacharyya, Shantanu; Rule, Gordon S.; Wilson, Ian A.; Armitage, Bruce A.; Waggoner, Alan S.; Berget, Peter B.

2012-01-01

219

A Variable Light Domain Fluorogen Activating Protein Homodimerizes To Activate Dimethylindole Red  

SciTech Connect

Novel fluorescent tools such as green fluorescent protein analogues and fluorogen activating proteins (FAPs) are useful in biological imaging for tracking protein dynamics in real time with a low fluorescence background. FAPs are single-chain variable fragments (scFvs) selected from a yeast surface display library that produce fluorescence upon binding a specific dye or fluorogen that is normally not fluorescent when present in solution. FAPs generally consist of human immunoglobulin variable heavy (V{sub H}) and variable light (V{sub L}) domains covalently attached via a glycine- and serine-rich linker. Previously, we determined that the yeast surface clone, V{sub H}-V{sub L} M8, could bind and activate the fluorogen dimethylindole red (DIR) but that the fluorogen activation properties were localized to the M8V{sub L} domain. We report here that both nuclear magnetic resonance and X-ray diffraction methods indicate the M8V{sub L} forms noncovalent, antiparallel homodimers that are the fluorogen activating species. The M8V{sub L} homodimers activate DIR by restriction of internal rotation of the bound dye. These structural results, together with directed evolution experiments with both V{sub H}-V{sub L} M8 and M8V{sub L}, led us to rationally design tandem, covalent homodimers of M8V{sub L} domains joined by a flexible linker that have a high affinity for DIR and good quantum yields.

Senutovitch, Nina; Stanfield, Robyn L.; Bhattacharyya, Shantanu; Rule, Gordon S.; Wilson, Ian A.; Armitage, Bruce A.; Waggoner, Alan S.; Berget, Peter B. (Scripps); (CM)

2012-07-11

220

Airship-floated wind turbine  

Microsoft Academic Search

A wind turbine, by use of a tethered airship for support, may be designed for the economical recovery of power at heights of 2,000 feet or more above ground, at which height power density in the wind is typically three times the power density available to a conventionally supported wind turbine. Means can be added to such an airship-floated wind

1985-01-01

221

An electrically excited nanoscale light source with active angular control of the emitted light.  

PubMed

We report on the angular distribution, polarization, and spectrum of the light emitted from an electrically controlled nanoscale light source. This nanosource of light arises from the local, low-energy, electrical excitation of localized surface plasmons (LSP) on individual gold nanoparticles using a scanning tunneling microscope (STM). The gold nanoparticles (NP) are chemically synthesized truncated bitetrahedrons. The emitted light is collected through the transparent substrate and the emission characteristics (angular distribution, polarization, and spectrum) are analyzed. These three observables are found to strongly depend on the lateral position of the STM tip with respect to the triangular upper face of the gold NP. In particular, the resulting light emission changes orientation when the electrical excitation via the STM tip is moved from the base to the vertex of the triangular face. On the basis of the comparison of the experimental observations with an analytical dipole model and finite-difference time-domain (FDTD) calculations, we show that this behavior is linked to the selective excitation of the out-of-plane and in-plane dipolar LSP modes of the NP. This selective excitation is achieved through the lateral position of the tip with respect to the symmetry center of the NP. PMID:23927672

Le Moal, Eric; Marguet, Sylvie; Rogez, Benot; Mukherjee, Samik; Dos Santos, Philippe; Boer-Duchemin, Elizabeth; Comtet, Genevive; Dujardin, Grald

2013-09-11

222

LIGHT, a member of the TNF superfamily, activates Stat3 mediated by NIK pathway  

SciTech Connect

Stat3, a member of the signal transducers and activators of transcription (STAT) family, is a key signal transduction protein activated by numerous cytokines, growth factors, and oncoproteins that controls cell proliferation, differentiation, development, survival, and inflammation. Constitutive activation of Stat3 has been found frequently in a wide variety of human tumors and induces cellular transformation and tumor formation. In this study, we demonstrated that LIGHT, a member of tumor necrosis factor superfamily, activates Stat3 in cancer cells. LIGHT induces dose-dependent activation of Stat3 by phosphorylation at both the tyrosine 705 and serine 727 residues. The activation of Stat3 by LIGHT appears to be mediated by NIK phosphorylation. Expression of a kinase-inactive NIK mutant abolished LIGHT induced Stat3 activation. Overexpression of an active NIK induces Stat3 activation by phosphorylation at the both tyrosine 705 and serine 727 residues. Activation of Stat3 by NIK requires NIK kinase activity as showed by kinase assays. In addition, LIGHT increases the expression of Stat3 target genes including cyclin D1, survivin, and Bcl-xL, and stimulates human LNCaP prostate cancer cell growth in vitro which can be blocked by expression of a dominant-negative Stat3 mutant. Taken together, these results indicate that in addition to activating NF-{kappa}B/p52, LIGHT also activates Stat3. Activation of Stat3 together with activating non-canonical NF-{kappa}B/p52 signaling by LIGHT may maximize its effects on cellular proliferation, survival, and inflammation.

Nadiminty, Nagalakshmi [Departments of Medicine, Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY 14263 (United States); Chun, Jae Yeon [Departments of Medicine, Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY 14263 (United States); Hu, Yan [Departments of Medicine, Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY 14263 (United States); Dutt, Smitha [Departments of Medicine, Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY 14263 (United States); Lin, Xin [Department of Molecular Oncology, MD Anderson Cancer Center, Houston, TX 77030 (United States); Gao, Allen C. [Departments of Medicine, Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY 14263 (United States)]. E-mail: allen.gao@roswellpark.org

2007-07-27

223

Light Travel Time and the Size of Active Galaxies  

NSDL National Science Digital Library

Using real data from NASA's Fermi satellite, students determine the size and energy of an active galaxy flare region. This activity includes background information for teachers, student worksheets, procedures, adaptations, extensions, an assessment rubric, and related resources. This is activity 3 of 3 in the "Active Galaxies Educator's Guide."

2012-08-03

224

Combinatorial Control of Light Induced Chromatin Remodeling and Gene Activation in Neurospora  

PubMed Central

Light is an important environmental cue that affects physiology and development of Neurospora crassa. The light-sensing transcription factor (TF) WCC, which consists of the GATA-family TFs WC1 and WC2, is required for light-dependent transcription. SUB1, another GATA-family TF, is not a photoreceptor but has also been implicated in light-inducible gene expression. To assess regulation and organization of the network of light-inducible genes, we analyzed the roles of WCC and SUB1 in light-induced transcription and nucleosome remodeling. We show that SUB1 co-regulates a fraction of light-inducible genes together with the WCC. WCC induces nucleosome eviction at its binding sites. Chromatin remodeling is facilitated by SUB1 but SUB1 cannot activate light-inducible genes in the absence of WCC. We identified FF7, a TF with a putative O-acetyl transferase domain, as an interaction partner of SUB1 and show their cooperation in regulation of a fraction of light-inducible and a much larger number of non light-inducible genes. Our data suggest that WCC acts as a general switch for light-induced chromatin remodeling and gene expression. SUB1 and FF7 synergistically determine the extent of light-induction of target genes in common with WCC but have in addition a role in transcription regulation beyond light-induced gene expression. PMID:25822411

Sancar, Cigdem; Ha, Nati; Yilmaz, Rstem; Tesorero, Rafael; Fisher, Tamas; Brunner, Michael; Sancar, Gencer

2015-01-01

225

[The painful floating-rib syndrome].  

PubMed

Attention is drawn to a painful syndrome in the front of the chest, due to abnormal mobility of a rib that has lost the normal cartilaginous connection with that above it. The syndrome is common enough, though little understood. Deep, continuous, dull and gravative pain is felt in the bottom of the chest and top of the abdomen, with distribution over the base of the hemithorax involved. It is relieved by rest and exacerbated by the effort and certain postures. One or more ribs on one or both sides may be affected, though the Xth is most commonly concerned. The condition may be the direct or indirect result of trauma, or congenital. Abnormal development of the XIth rib may result in its riding over that above it and so causing pain. The formation of parietal algogenous sites is thought to be primarily responsible for pain. These sites result from rubbing of the end of the free cartilage on neighbouring structures. Direct compression of the corresponding trunk may also be involved. Objective diagnosis is based on topical signs. The floating rib is readily recognised as the cause of pain and the syndrome itself is known as the painful slipped (better, floating) rib syndrome. Satisfactory results are obtained by deep analgesic infiltration at the end of the free cartilage and can be prolonged by rest. Reference is made to previously reported data concerning functional disorders of the extrahepatic bile ducts in subjects with this syndrome in the light of a more ample case series. The radiological picture is usually marked by gall bladder hypertonia and hyperkinesis, with occasional sphincter involvement. The physiopathogenetic interpretation of these associated parietobiliary manifestations is discussed in the light of experimental and therapeutic evidence. Their clinical interest is also stressed. PMID:1153118

Frad, G

1975-08-18

226

Regulation of Transcription through Light-Activation and Light-Deactivation of Triplex-Forming Oligonucleotides in Mammalian Cells  

PubMed Central

Triplex-forming oligonucleotides (TFOs) are efficient tools to regulate gene expression through the inhibition of transcription. Here, nucleobase-caging technology was applied to the first temporal regulation of transcription through light-activated TFOs. Through site-specific incorporation of caged thymidine nucleotides, the TFO:DNA triplex formation is blocked, rendering the TFO inactive. However, after a brief UV irradiation, the caging groups are removed, activating the TFO, and leading to the inhibition of gene transcription. Furthermore, the synthesis and site-specific incorporation of caged deoxycytidine nucleotides within TFO inhibitor sequences was developed, and allows for the light-deactivation of TFO function and thus photochemical activation of gene expression. After UV-induced removal of the caging groups, the TFO forms a DNA dumbbell structure, rendering it inactive, releasing it from the DNA, and activating transcription. These are the first examples of light-regulated TFOs and their application in the photochemical activation and deactivation of gene expression. In addition, hairpin loop structures were found to significantly increase the efficacy of phosphodiester DNA-based TFOs in tissue culture. PMID:22540192

Govan, Jeane M.; Uprety, Rajendra; Hemphill, James; Lively, Mark O.

2012-01-01

227

Sinking and Floating Water  

NSDL National Science Digital Library

This activity is a classroom lab where students learn that cold water is denser and hot water is less dense than room temperature water. Students perform an experiment and relate to their background knowledge to make conjectures.

nancy thill

228

Will My Fossil Float?  

ERIC Educational Resources Information Center

Explains how young students can be introduced to fossils. Suggests books to read and science activities including "Fossils to Eat" where students make fossils from peanut butter, honey, and powdered milk. (PR)

Riesser, Sharon; Airey, Linda

1993-01-01

229

Floating and Falling Flows  

NSDL National Science Digital Library

Learners create beautiful fluid motion. They explore fluid dynamics, surface tension, solubility, and buoyancy while mixing liquids together. Learners can photograph or film the fluid motion for analysis as well. This activity is also suitable as a demonstration. Learners can continue their investigations by completing the related activity "Density Rainbow and the Great Viscosity Race." Resource contains vocabulary definitions, detailed background information, and suggestions for assessment and extensions.

Cody Taylor

2006-01-01

230

Balloons and Other Things That Sometimes Float  

NSDL National Science Digital Library

Hot air balloons float--sometimes. Regular old balloons that you get at a party float--sometimes. Boats float--sometimes. What makes them float and what makes them sink? How can a boat made of steel float but a solid chunk of steel sink to the bottom of the ocean? Part of the answer has to do with something called density, which will be discussed in this chapter. And yes, the concepts addressed in this chapter do have a lot to do with weather.

2005-01-01

231

Human and Drosophila Cryptochromes Are Light Activated by Flavin Photoreduction in Living Cells  

PubMed Central

Cryptochromes are a class of flavoprotein blue-light signaling receptors found in plants, animals, and humans that control plant development and the entrainment of circadian rhythms. In plant cryptochromes, light activation is proposed to result from photoreduction of a protein-bound flavin chromophore through intramolecular electron transfer. However, although similar in structure to plant cryptochromes, the light-response mechanism of animal cryptochromes remains entirely unknown. To complicate matters further, there is currently a debate on whether mammalian cryptochromes respond to light at all or are instead activated by nonlight-dependent mechanisms. To resolve these questions, we have expressed both human and Drosophila cryptochrome proteins to high levels in living Sf21 insect cells using a baculovirus-derived expression system. Intact cells are irradiated with blue light, and the resulting cryptochrome photoconversion is monitored by fluorescence and electron paramagnetic resonance spectroscopic techniques. We demonstrate that light induces a change in the redox state of flavin bound to the receptor in both human and Drosophila cryptochromes. Photoreduction from oxidized flavin and subsequent accumulation of a semiquinone intermediate signaling state occurs by a conserved mechanism that has been previously identified for plant cryptochromes. These results provide the first evidence of how animal-type cryptochromes are activated by light in living cells. Furthermore, human cryptochrome is also shown to undergo this light response. Therefore, human cryptochromes in exposed peripheral and/or visual tissues may have novel light-sensing roles that remain to be elucidated. PMID:18597555

Hoang, Nathalie; Schleicher, Erik; Kacprzak, Sylwia; Bouly, Jean-Pierre; Picot, Marie; Wu, William; Berndt, Albrecht; Wolf, Eva; Bittl, Robert; Ahmad, Margaret

2008-01-01

232

Diet Light  

NSDL National Science Digital Library

In this quick activity, learners observe how the added sugar in a can of soda affects its density and thus, its ability to float in water. Learners explore this phenomenon by testing if two cans of soda (one regular, one diet or "sugar-free") float in a fish-tank filled with water. Use this activity to introduce learners to the concepts of density and water displacement. This resource also explains how atmospheric density plays a role in meteorology and includes thunderstorm safety tips.

National Weather Service

2012-06-26

233

Electrically controlled transfer of spin angular momentum of light in an optically active medium  

NASA Astrophysics Data System (ADS)

Spin is an intrinsic property of the photon. A method for using an externally applied dc electric field to manipulate the transfer of spin angular momentum of light in an optically active medium is presented. To discuss this, we first develop a wave coupling theory of the mutual action of natural optical activity and the linear electro-optic effect. Besides being used for analyzing the electrically controlled transfer of spin angular momentum of light, the theory can also be used to describe the propagation of light traveling along an arbitrary direction in any optically active medium with an external dc electric field along an arbitrary direction.

Chen, Lixiang; Zheng, Guoliang; Xu, Jie; Zhang, Bingzhi; She, Weilong

2006-12-01

234

TO FLOAT OR NOT TO FLOAT? CURRENCY REGIMES AND GROWTH  

Microsoft Academic Search

One recent line of research on exchange rates is the effect of fixed or floating currencies on long-term growth. One difficulty with such studies is that emerging market countries with certain imbalances and potentially hard-to-observe policy distortions are more likely to choose a fixed exchange rate regime, and thus estimates of the effect of exchange rates on growth are likely

William Miles

2006-01-01

235

Activation Energy of Light Induced Isomerization of Resveratrol  

Microsoft Academic Search

Isomerization of trans-stilbenes is known to be induced by light. The two isomers have distinct absorption, fluorescence excitation and emission\\u000a spectra. Resveratrol, 3,4?,5-trihydroxystilbene, is a member of the stilbene family. The interest of the scientific community\\u000a in resveratrol has increased over the last years due to its biomedical properties. Whereas there is a growing confidence that\\u000a trans-resveratrol is non-toxic, very

Teresa Sofia Figueiras; Maria Teresa Neves-Petersen; Steffen B. Petersen

236

Temporal and spatial distribution of floating objects in coastal waters of central-southern Chile and Patagonian fjords  

NASA Astrophysics Data System (ADS)

Floating objects are suggested to be the principal vector for the transport and dispersal of marine invertebrates with direct development as well as catalysts for carbon and nutrient recycling in accumulation areas. The first step in identifying the ecological relevance of floating objects in a specific area is to identify their spatio-temporal distribution. We evaluated the composition, abundance, distribution, and temporal variability of floating objects along the continental coast of central-southern Chile (33-42S) and the Patagonian fjords (42-50S) using ship surveys conducted in austral winter (July/August) and spring (November) of the years 2002-2005 and 2008. Potential sources of floating items were identified with the aid of publicly available databases and scientific reports. We found three main types of floating objects, namely floating marine debris (mainly plastic objects and Styrofoam), wood (trunks and branches), and floating kelps ( Macrocystis pyrifera and Durvillaea antarctica). Floating marine debris were abundant along most of the examined transects, with markedly lower abundances toward the southern fjord areas. Floating marine debris abundances generally corresponded to the distribution of human activities, and were highest in the Interior Sea of Chilo, where aquaculture activities are intense. Floating wood appeared sporadically in the study area, often close to the main rivers. In accordance with seasonal river run-off, wood was more abundant along the continental coast in winter (rainy season) and in the Patagonian fjords during the spring surveys (snow melt). Densities of the two floating kelp species were similar along the continental coast, without a clear seasonal pattern. M. pyrifera densities increased towards the south, peaking in the Patagonian fjords, where it was dominant over D. antarctica. Densities of M. pyrifera in the Patagonian fjords were highest in spring. Correlation analyses between the abundances of floating objects and the distance to the nearest sources were generally non-significant, suggesting that post-supply processes affect the distribution of the floating objects in the study region. The identification of several major retention zones supports this idea. Accumulation areas of floating objects appear to be more common in the fjord zones. In general, the results underscore the abundance of floating objects throughout the study region and the fact that floating marine debris sources are mostly local, whereas floating algae may be dispersed over greater distances. Future studies should focus on the ecological role of floating objects in biota dispersal and nutrient cycling.

Hinojosa, Ivn A.; Rivadeneira, Marcelo M.; Thiel, Martin

2011-03-01

237

Retinal Pigment Epithelial (RPE) Verification of melanin function as a light activated ROS scavenger  

E-print Network

;Verification of melanin function as a light activated ROS scavenger ABSTRACT Melanin is a heterogeneous. Furthermore, Melanin is believed that it serves as a photo-protective role in vision by absorbing light and a scavenger of free radicals and reactive oxygen species (ROS). Heterogeneous melanin aggregates from Sepia

238

Nitrate reductase activity in corn seedlings as affected by light and nitrate content of nutrient media  

Microsoft Academic Search

Young corn plants placed in complete darkness for 48 hours lost 90% of their nitrate reductase activity. The activity was quickly restored when the plants were returned to the light. In other experiments, corn plants were grown under artificial shade in the greenhouse. The nitrate reductase activity in these plants decreased roughly in proportion to the amount of shading. It

R. H. Hageman; D. Flesher

1960-01-01

239

Young Scientists Explore Light & Color. Book 12--Intermediate Level. A Good Apple Activity Book.  

ERIC Educational Resources Information Center

Designed to develop creativity in young learners, this book contains interdisciplinary activities which focus on the theme of light and color. Activity pages are provided that can serve as front and back covers of a student booklet and the suggested activities can be duplicated for insertion between the covers resulting in a booklet for each

DeBruin, Jerry

240

A Classroom Demonstration of Rayleigh Light Scattering in Optically Active and Inactive Systems  

Microsoft Academic Search

Optical activity is a property of molecules that causes the rotation of the electric field vector of light as it travels through an optically active medium. The concept of optical activity often remains vague to students. It often must be taken for granted by students because it is difficult for instructors to demonstrate the phenomenon in the classroom. A few

Monica Avalos Pecina; Charles A. Smith; Penny Snetsinger; Ed Vitz

1999-01-01

241

Challenges for reducing the size of laser activated remote phosphor light engines for DLP projection  

NASA Astrophysics Data System (ADS)

Laser activated remote phosphor (LARP) is an upcoming technology for high luminance SSL light engines. This presentation outlines some of the challenges met reducing the engine's size, so it can be retrofitted into DLP-projectors.

Hartwig, Ulrich; Bruemmer, Mathias

2014-12-01

242

Physiological relevant in vitro evaluation of polymer coats for gastroretentive floating tablets.  

PubMed

Gastroretentive drug delivery systems are retained in the stomach for a sufficient time interval, releasing the drug in a controlled manner. According to literature, the floating principle is the most frequently used formulation approach for gastric retention. However, many publications lack information of the floating forces, the impact of different pH-values and almost no information exist concerning the resistance of the floating performance against physiological relevant stress. Therefore, we evaluated the performance of CO2-generating floating bilayer (drug and floating layer) tablets with respect to robustness, drug release profile, pH dependence and floating behaviour. Bilayer tablets were coated with a flexible and water permeable, but CO2-retaining polymer film of either polyvinyl acetate or ammonio-methacrylate copolymer type A. Metformin-HCl was used as a relevant model drug due to its dose-dependent and saturable absorption from the proximal part of the small intestine. To mimic physiological relevant mechanical stress conditions, recently developed dissolution stress tests with pulsed pressures were applied in addition to release studies according to the pharmacopeia. Bilayer tablets coated with polyvinyl acetate showed short floating lag times, reasonable floating strength values, floating durations of more than 24h in simulated gastric fluid and a robust and pH independent release of Metformin-HCl. Tablets coated with ammonio-methacrylate copolymer type A showed a higher permeability for the active ingredient combined with a decreased robustness of the inflated tablets. Both polymers can be used for balloon-like floating devices. The appropriate polymer has to be chosen dependent from the properties of the active ingredient and requested application of the delivery device. Furthermore, the dissolution stress test analysis is able to indicate possible safety issues of gastroretentive formulations as well as to characterise the robustness of formulation principles towards mechanical stresses of bio-relevant intensity. PMID:25086221

Eisencher, Friederike; Garbacz, Grzegorz; Mder, Karsten

2014-11-01

243

Measurement of brain activity by near-infrared light  

Microsoft Academic Search

We review our most recent results on near-IR studies of human brain activity, which have been evolving in two directions: detection of neuronal signals and measurements of functional hemo- dynamics. We discuss results obtained so far, describing in detail the techniques we developed for detecting neuronal activity, and present- ing results of a study that, as we believe, confirms the

Enrico Gratton; Vladislav Toronov; Ursula Wolf; Martin Wolf; Andrew Webb

2005-01-01

244

Role of the Essential Light Chain in the Activation of Smooth Muscle Myosin by Regulatory Light Chain Phosphorylation  

PubMed Central

The activity of smooth and non-muscle myosin II is regulated by phosphorylation of the regulatory light chain (RLC) at serine 19. The dephosphorylated state of full-length monomeric myosin is characterized by an asymmetric intramolecular head-head interaction that completely inhibits the ATPase activity, accompanied by a hairpin fold of the tail, which prevents filament assembly. Phosphorylation of serine 19 disrupts these head-head interactions by an unknown mechanism. Computational modeling suggested that formation of the inhibited state is characterized by both torsional and bending motions about the myosin heavy chain (HC) at a location between the RLC and the essential light chain (ELC). Therefore, altering relative motions between the ELC and the RLC at this locus might disrupt the inhibited state. Based on this hypothesis we have derived an atomic model for the phosphorylated state of the smooth muscle myosin light chain domain (LCD). This model predicts a set of specific interactions between the N-terminal residues of the RLC with both the myosin HC and the ELC. Site directed mutagenesis was used to show that interactions between the phosphorylated N-terminus of the RLC and helix-A of the ELC are required for phosphorylation to activate smooth muscle myosin. PMID:24361582

Taylor, Kenneth A.; Feig, Michael; Brooks, Charles L.; Fagnant, Patricia M.; Lowey, Susan; Trybus, Kathleen M.

2014-01-01

245

Dependence of aptamer activity on opposed terminal extensions: improvement of light-regulation efficiency  

PubMed Central

Aptamers that can be regulated with light allow precise control of protein activity in space and time and hence of biological function in general. In a previous study, we showed that the activity of the thrombin-binding aptamer HD1 can be turned off by irradiation using a light activatable caged intramolecular antisense-domain. However, the activity of the presented aptamer in its ON state was only mediocre. Here we studied the nature of this loss in activity in detail and found that switching from 5?- to 3?-extensions affords aptamers that are even more potent than the unmodified HD1. In particular we arrived at derivatives that are now more active than the aptamer NU172 that is currently in phase 2 clinical trials as an anticoagulant. As a result, we present light-regulatable aptamers with a superior activity in their ON state and an almost digital ON/OFF behavior upon irradiation. PMID:20007153

Buff, Maximilian C. R.; Schfer, Florian; Wulffen, Bernhard; Mller, Jens; Ptzsch, Bernd; Heckel, Alexander; Mayer, Gnter

2010-01-01

246

Float zone experiments in space  

NASA Technical Reports Server (NTRS)

The molten zone/freezing crystal interface system and all the mechanisms were examined. If Marangoni convection produces oscillatory flows in the float zone of semiconductor materials, such as silicon, then it is unlikely that superior quality crystals can be grown in space using this process. The major goals were: (1) to determine the conditions for the onset of Marangoni flows in molten tin, a model system for low Prandtl number molten semiconductor materials; (2) to determine whether the flows can be suppressed by a thin oxide layer; and (3) based on experimental and mathematical analysis, to predict whether oscillatory flows will occur in the float zone silicon geometry in space, and if so, could it be suppressed by thin oxide or nitride films. Techniques were developed to analyze molten tin surfaces in a UHV system in a disk float zone geometry to minimize buoyancy flows. The critical Marangoni number for onset of oscillatory flows was determined to be greater than 4300 on atomically clean molten tin surfaces.

Verhoeven, J. D.; Noack, M. A.; Gill, W. N.; Hau, C. C.

1984-01-01

247

Remote control of molecular motors using light-activated gearshifting  

NASA Astrophysics Data System (ADS)

Engineering molecular motors with dynamically controllable properties will allow selective perturbation of mechanical processes in vivo and provide sophisticated components for directed nanoscale transport in vitro. We previously constructed myosin motors that respond to a change in [Ca++] by reversing their direction of motion along the polarized actin filament [1]. To expand the potential applications of controllable molecular motors, we have now developed myosins that shift gears in response to blue light illumination. Light is a versatile control signal that can be readily modulated in time and space, and is generally orthogonal to cellular signaling. Using structure-guided protein engineering, we have incorporated LOV photoreceptor domains into the lever arms of chimeric myosins, resulting in motors that robustly speed up, slow down, or switch directions upon illumination. These genetically encoded motors should be directly deployable inside living cells. Our successful designs include constructs based on two different myosin classes, and we show that optical velocity control can be implemented in motors that move at microns/sec speeds, enabling practical biological and bioengineering applications.[4pt] [1] Chen, L., Nakamura, M., Schindler,T.D., and Bryant Z. (2012). Nat. Nanotechnol. 7, 252-6.

Bryant, Zev

2013-03-01

248

A novel light-dependent activation of DAGK and PKC in bovine photoreceptor nuclei.  

PubMed

In this work, we describe a selective light-dependent distribution of the lipid kinase 1,2-diacylglycerol kinase (EC 2.7.1.107, DAGK) and the phosphorylated protein kinase C alpha (pPKC?) in a nuclear fraction of photoreceptor cells from bovine retinas. A nuclear fraction enriched in small nuclei from photoreceptor cells (PNF), was obtained when a modified nuclear isolation protocol developed by our laboratory was used. We measured and compared DAGK activity as phosphatidic acid (PA) formation in PNF obtained from retinas exposed to light and in retinas kept in darkness using [?-(32)P]ATP or [(3)H]DAG. In the absence of exogenous substrates and detergents, no changes in DAGK activity were observed. However, when DAGK activity assays were performed in the presence of exogenous substrates, such as stearoyl arachidonoyl glycerol (SAG) or dioleoyl glycerol (DOG), and different detergents (used to make different DAGK isoforms evident), we observed significant light effects on DAGK activity, suggesting the presence of several DAGK isoforms in PNF. Under conditions favoring DAGK? activity (DOG, Triton X-100, dioleoyl phosphatidylserine and R59022) we observed an increase in PA formation in PNF from retinas exposed to light with respect to those exposed to darkness. In contrast, under conditions favoring DAGK? (SAG, octylglucoside and R59022) we observed a decrease in its activity. These results suggest different physiological roles of the above-mentioned DAGK isoforms. Western blot analysis showed that whereas light stimulation of bovine retinas increases DAGK? nuclear content, it decreases DAGK? and DAGK? content in PNF. The role of PIP2-phospholipase C in light-stimulated DAGK activity was demonstrated using U73122. Light was also observed to induce enhanced pPKC? content in PNF. The selective distribution of DAGK? and ? in PNF could be a light-dependent mechanism that in vertebrate retina promotes selective DAG removal and PKC regulation. PMID:24950064

Natalini, Paola M; Mateos, Melina V; Ilincheta de Boschero, Mnica G; Giusto, Norma M

2014-08-01

249

Floating full-color image with computer-generated alcove rainbow hologram  

NASA Astrophysics Data System (ADS)

We have investigated the floating full color image display with the computer-generated hologram (CGH). The floating image, when utilized as a 3D display, gives strong impression to the viewer. In our previous study, to change the CGH shape from the flat type to the half cylindrical type, the floating image from the output CGH has the nearly 180 degrees viewing angle. However, since the previous CGH does not have wavelength-selectivity, reconstructed image only has a single color. Also, the huge calculation amount of the fringe pattern is big problem. Therefore, we now propose the rainbow-type computer generated alcove hologram. To decrease the calculation amount, the rainbow hologram sacrifices the vertical parallax. Also, this hologram can reconstruct an image with white light. Compared with the previous study of the Fresnel type, the calculation speed becomes 165 times faster. After calculation, we print this hologram with a fringe printer, and evaluate reconstructed floating full color images. In this study, we introduce the computer-generated rainbow hologram into the floating image display. The rainbow hologram can reconstruct full color image with white light illumination. It can be recorded by using a horizontal slit to limit the vertical parallax. Therefore, the slit changes into the half cylindrical slit, the wide viewing angle floating image display can reconstruct full color image.

Yamaguchi, Takeshi; Yoshikawa, Hiroshi

2014-02-01

250

Daily activity and light exposure levels for five species of lemurs at the Duke Lemur Center.  

PubMed

Light is the primary synchronizer of all biological rhythms, yet little is known about the role of the 24-hour luminous environment on nonhuman primate circadian patterns, making it difficult to understand the photic niche of the ancestral primate. Here we present the first data on proximate light-dark exposure and activity-rest patterns in free-ranging nonhuman primates. Four individuals each of five species of lemurs at the Duke Lemur Center (Eulemur mongoz, Lemur catta, Propithecus coquereli, Varecia rubra, and Varecia variegata variegata) were fitted with a Daysimeter-D pendant that contained light and accelerometer sensors. Our results reveal common as well as species-specific light exposure and behavior patterns. As expected, all five species were more active between sunrise and sunset. All five species demonstrated an anticipatory increase in their pre-sunrise activity that peaked at sunrise with all but V. rubra showing a reduction within an hour. All five species reduced activity during mid-day. Four of the five stayed active after sunset, but P. coquereli began reducing their activity about 2 hours before sunset. Other subtle differences in the recorded light exposure and activity patterns suggest species-specific photic niches and behaviors. The eventual application of the Daysimeter-D in the wild may help to better understand the adaptive evolution of ancestral primates. PMID:24318943

Rea, Mark S; Figueiro, Mariana G; Jones, Geoffrey E; Glander, Kenneth E

2014-01-01

251

The impact of floating migration on fertility in China: are floating migrants "childbearing guerillas"?  

E-print Network

The increasing number of floating migrants in the big cities of China is the result of the household registration (hukou) system and the fast growing market-economy in China. The mass media have portrayed floating migrants as "childbearing...

You, Xiuhong

2002-01-01

252

Relational Abstract Domains for the Detection of Floating-Point  

E-print Network

ESOP'2004 Relational Abstract Domains for the Detection of Floating-Point Run-Time Errors Antoine-time error. Floating-Point Nowadays, embedded software use floating-point numbers instead of fixed-point. Floating-point numbers are complex, not always understood by programmers. Floating-point numbers

Miné, Antoine

253

Intel I/O, Floating point o DOS System Calls  

E-print Network

Intel I/O, Floating point o DOS System Calls o Floating point 2 #12; Floating Point o integer: 1, 2, 3, 4 o fixed point: 100.001, 100.002, 123.456 o floating point: 100 x 103 , 101 x 103 , 123 x 105 o in the floating point

Biagioni, Edoardo S.

254

Novel floating FDNR, inductor and capacitor simulator using CBTA  

Microsoft Academic Search

In this study novel floating frequency dependent negative resistor (FDNR), floating inductor (FI), floating capacitor and floating resistor simulator circuit employing two CBTAs and three passive components is proposed. The presented circuit can realize floating FDNR, inductor, capacitor or resistor depending on the passive component selection. Since the passive elements are all grounded, this circuit is suitable for fully integrated

Umut Engin Ayten; Mehmet Sagbas; Norbert Herencsar; Jaroslav Koton

2011-01-01

255

The impact on seaplane floats during landing  

NASA Technical Reports Server (NTRS)

In order to make a stress analysis of seaplane floats, and especially of the members connecting the floats with the fuselage, it is of great importance to determine the maximum pressure acting on the floats during landing. Here, the author gives a formula for maximum pressures during landing that permits one to apply experimental results to different bodies and different velocities. The author notes that the formula checks very well with experimental results.

Von Karman, TH

1929-01-01

256

Tank Tests of Twin Seaplane Floats  

NASA Technical Reports Server (NTRS)

The following report contains the most essential data for the hydrodynamic portion of the twin-float problem. The following points were successfully investigated: 1) difference between stationary and nonstationary flow; 2) effect of the shape of the step; 3) effect of distance between floats; 4) effect of nose-heavy and tail-heavy moments; 5) effect of the shape of floats; 6) maneuverability.

Herrman, H; Kempf, G; Kloess, H

1928-01-01

257

The decay of the ATPase activity of light plus thiol-activated thylakoid membranes in the dark.  

PubMed

Oxidized ATP synthase of spinach thylakoid membranes catalyzes high rates of ATP synthesis in the light, but very low rates of ATP hydrolysis in the dark. Reduction of the disulfide bond in the gamma subunit of the ATP synthase in the light enhances the rate of Mg2+-ATP hydrolysis in the dark. The light plus thiol-activated state decays in a few minutes in the dark after illumination in Tris buffer, but not when Tricine was used in place of Tris. In this paper, it is shown that Tris in the assay mixture is an inhibitor of the light plus thiol-activated ATPase activity of thylakoids, but only after the activated membranes had incubated in the dark. Aminopropanediols and diethanolamine, also selectively inhibited ATPase activity of activated membranes after storage in the dark, whereas NH4Cl and imidazole inhibit the ATPase activity of activated thylakoids almost equally whether they are added directly after the illumination or several minutes later. The fluorescence of 9-amino-6-chloro-2-methoxyacridine (ACMA) is quenched by the establishment of proton gradients by ATP-dependent proton uptake. Addition of ATP to activated membranes results in rapid quenching of ACMA fluorescence. If the activated membranes were incubated in the dark prior to ATP addition, a lag in the ATP-dependent ACMA fluorescence quenching as well as a similar lag in the rate ATP hydrolysis were seen. It is concluded that ADP rebinds to CF1 in the dark following illumination and inhibits the activity of the ATP synthase. Reactivation of the ATP synthase in the dark can occur by the slow generation of proton gradients by ATP hydrolysis in the dark. This reactivation takes place in Tricine buffer, but not in Tris because of its uncoupling action. Whether ADP binding plays a role in the regulation of the activity of the ATP synthase in situ remains to be established. PMID:16775764

McCarty, Richard E

2006-02-01

258

Active optics: A new technology for the control of light  

Microsoft Academic Search

Active optical systems are those in which real-time control over optical wavefronts is employed to optimize system perference in the presence of random distrurbances. Applications include 1) outgoingwave systems for maximizing the power density of a laser beam on a target and 2) received-wave systems for maximizing the angular resolving power of a telescope viewing a distant object through a

J. W. Hardy

1978-01-01

259

Modeling International Space Station (ISS) Floating Potentials  

NASA Technical Reports Server (NTRS)

The floating potential of the International Space Station (ISS) as a function of the electron current collection of its high voltage solar array panels is derived analytically. Based on Floating Potential Probe (FPP) measurements of the ISS potential and ambient plasma characteristics, it is shown that the ISS floating potential is a strong function of the electron temperature of the surrounding plasma. While the ISS floating potential has so far not attained the pre-flight predicted highly negative values, it is shown that for future mission builds, ISS must continue to provide two-fault tolerant arc-hazard protection for astronauts on EVA.

Ferguson, Dale C.; Gardner, Barbara

2002-01-01

260

Human platelet myosin light chain kinase requires the calcium-binding protein calmodulin for activity.  

PubMed Central

In an actomyosin fraction isolated from human platelets, phosphorylation of the 20,000-dalton light chain of myosin is stimulated by calcium and the calcium-binding protein calmodulin. The enzyme catalyzing this phosphorylation has been isolated by using calmodulin-affinity chromatography. Platelet myosin light chain kinase activity was monitored throughout the isolation procedures by using the 20,000-dalton smooth muscle myosin light chain purified from turkey gizzards as substrate. The partially purified myosin kinase requires both calcium and calmodulin for activity and has a specific activity of 3.1 mumol of phosphate transferred to the 20,000-dalton light chain per mg of kinase per min under optimal assay conditions. Km values determined for ATP and myosin light chains are 121 microM and 18 microM, respectively. Of several substrates surveyed as phosphate acceptors (alpha-casein, histone II-A, phosphorylase b, protamine, histone V-S, and phosvitin), only the 20,000-dalton myosin light chain is phosphorylated at a significant rate. These results suggest that platelet myosin light chain kinase is a calcium-dependent enzyme and that the requirement for calcium is mediated by the calcium-binding protein calmodulin. Images PMID:156362

Hathaway, D R; Adelstein, R S

1979-01-01

261

Barotropic ocean velocity observations from an electric field float, a modified RAFOS float  

Microsoft Academic Search

A seldom observed characteristic of ocean motion is depth-averaged velocity, or transport per unit width. One approach to observing this quantity is to measure the ambient horizontal electric field of the ocean with electric field sensors added to a RAFOS float. The Electric Field Float (EFF) is a RAFOS float modified by the addition of a compass, electrode arms, amplifiers,

Thomas B. Sanford; R. G. Drever; J. H. Dunlap

1995-01-01

262

40 CFR 65.45 - External floating roof converted into an internal floating roof.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false External floating roof converted into an internal...RULE Storage Vessels 65.45 External floating roof converted into an internal...regulated material emissions by using an external floating roof converted into an...

2010-07-01

263

Activating neurons by light in free-moving adult flies  

NASA Astrophysics Data System (ADS)

In this presentation, we show our preliminary results which is related to neurons activation in vivo by laser. A laser scanning system was adopted to guide laser beam to an assigned fly and an assigned position. A 473-nm laser can be a heat punishment source to restrain a wild-type fly's moving area. Furthermore, neurons in optogenetics transgene flies can be triggered by the blue laser in this system.

Wu, Ming-Chin; Hsiao, Po-Yen; Chu, Li-An; Lin, Yen-Yin; Fu, Chien-Chung; Chiang, Ann-Shyn

2015-01-01

264

Ambipolar organic thin-film transistor-based nano-floating-gate nonvolatile memory  

SciTech Connect

An ambipolar organic thin-film transistor-based nano-floating-gate nonvolatile memory was demonstrated, with discrete distributed gold nanoparticles, tetratetracontane (TTC), pentacene as the floating-gate layer, tunneling layer, and active layer, respectively. The electron traps at the TTC/pentacene interface were significantly suppressed, which resulted in an ambipolar operation in present memory. As both electrons and holes were supplied in the channel and trapped in the floating-gate by programming/erasing operations, respectively, i.e., one type of charge carriers was used to overwrite the other, trapped, one, a large memory window, extending on both sides of the initial threshold voltage, was realized.

Han, Jinhua; Wang, Wei, E-mail: wwei99@jlu.edu.cn; Ying, Jun; Xie, Wenfa [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012 (China)] [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012 (China)

2014-01-06

265

Rapid light-induced activation of retinal microglia in mice lacking Arrestin-1.  

PubMed

Microglia dynamically prune synaptic contacts during development, and digest waste that accumulates in degeneration and aging. In many neurodegenerative diseases, microglial activation and phagocytosis gradually increase over months or years, with poorly defined initial triggering events. Here, we describe rapid retinal microglial activation in response to physiological light levels in a mouse model of photoreceptor degeneration that arises from defective rhodopsin deactivation and prolonged signaling. Activation, migration and proliferation of microglia proceeded along a well-defined time course apparent within 12 h of light onset. Retinal imaging in vivo with optical coherence tomography revealed dramatic increases in light-scattering from photoreceptors prior to the outer nuclear layer thinning classically used as a measure of retinal neurodegeneration. This model is valuable for mechanistic studies of microglial activation in a well-defined and optically accessible neural circuit, and for the development of novel methods for detecting early signs of pending neurodegeneration in vivo. PMID:25091460

Levine, Emily S; Zam, Azhar; Zhang, Pengfei; Pechko, Alina; Wang, Xinlei; FitzGerald, Paul; Pugh, Edward N; Zawadzki, Robert J; Burns, Marie E

2014-09-01

266

Effects of special blue fluorescent light on hepatic mixed-function oxidase activity in the rat  

SciTech Connect

Phototherapy has been widely used in the treatment of neonatal hyperbilirubinemia. Recent reports, however, have indicated that fluorescent light may be toxic and mutagenic to mammalian cells. these findings suggest possible long-term side effects with the use of phototherapy. This study was undertaken to determine the effects of phototherapy on hepatic microsomal enzyme activity. The exposure of Sprague-Dawley and Gunn rats to special blue fluorescent light at an average irradiance of 1,200 microW/cm2 resulted in no significant changes in liver microsomal enzyme activity for aniline hydroxylase, p-nitroanisole-O-demethylase, ethylmorphine-N-demethylase, cytochrome c reductase or the quantity of cytochrome P-450. A significant decrease in aniline hydroxylase and p-nitroanisole-O-demethylase activity was observed when liver microsomes were exposed in vitro to special blue fluorescent light. Photoactivated bilirubin did not effect the activity of the mixed-function oxidase enzymes measured under the conditions of this study.

Davis, D.R.; Yeary, R.A.; Randall, G.

1981-01-01

267

Floating patella associated with lymphoedema.  

PubMed

Ipsilateral injury of more than one component of the knee extensor apparatus is rare. It is mostly associated with previous trauma, surgery, immunosuppression therapy and systemic disease. We present the first documented case of a spontaneous bifocal disruption of the knee extensor apparatus (i.e. floating patella) associated with lymphoedema. This case highlights the importance of considering lymphoedema as another risk factor for rupture of the knee extensor apparatus. It also highlights the importance of assessing all components of the knee extensor apparatus in patients presenting with acute knee injuries. PMID:25802253

Vun, Shen Hwa; Bayam, Levent; Drampalos, Efstathios; Jesry, Mohammed; Fadel, George

2015-01-01

268

El Hierro's floating stones as messengers of crust-magma interaction at depth  

NASA Astrophysics Data System (ADS)

During the early stages of the submarine eruption that started on October 10 2011 south of El Hierro, Canary Islands, Spain, peculiar eruption products were found floating on the sea surface. These centimetre- to decimetre-sized "bombs" have been termed "restingolites" after the nearby village La Restinga and consist of a basaltic rind and a white to light grey core that resembles pumice in texture. According to Troll et al. (2011; see also Troll et al. EGU 2012 Abstracts), this material consists of a glassy matrix hosting extensive vesicle networks, which results in extremely low densities allowing these rocks to float on sea water. Mineralogical and geochemical analyses reveal that the "restingolites" originate from the sedimentary rocks (sand-, silt-, and mudstones) that form layer 1 of the oceanic crust beneath El Hierro. During the onset and early stages of the eruption, magma ponded at the base of this sedimentary sequence, breaking its way through the sedimentary rocks to the ocean floor. The textures of the "restingolites" reveal that crust-magma interaction during fragmentation and transport of the xenoliths involved rapid partial melting and volatile exsolution. Xenoliths strikingly similar to those from El Hierro are known from eruptions on other Canary Islands (e.g. La Palma, Gran Canaria, and Lanzarote). In fact, they resemble in texture xenoliths of various protoliths from volcanic areas worldwide (e.g. Krakatao, Indonesia, Cerro Quemado, Guatemala, Laacher See, Germany). This indicates that the process of partial melting and volatile exsolution, which the "restingolites" bear witness of, is probably occurring frequently during shallow crustal magma emplacement. Thermomechanical numerical models of the effect of the density decrease associated with the formation of vesicle networks in partially molten xenoliths show that xenoliths of crustal rocks initially sink in a magma chamber, but may start to float to the chamber roof once they start to heat up and vesiculate. The "floating stones" from El Hierro thus represent the products of crust-magma interaction beneath the Canary Islands, but is probably relevant in most volcanic areas and tectonic settings. In addition, xenolith devolatilisation has important general implications for the mechanics of crustal recycling, magma emplacement into the upper crust and volatile release from active volcanic systems.

Burchardt, S.; Troll, V. R.; Schmeling, H.; Koyi, H.; Blythe, L. S.; Longpr, M. A.; Deegan, F. M.

2012-04-01

269

Algorithms for Arbitrary Precision Floating Point Arithmetic \\Lambda  

E-print Network

Algorithms for Arbitrary Precision Floating Point Arithmetic \\Lambda Douglas M. Priest Department to perform computations of very high accuracy using only straightforward floating point arithmetic operations satisfied by most implementations of floating point arithmetic. To illustrate the application

Shewchuk, Jonathan

270

Monte Carlo Arithmetic: exploiting randomness in floating-point arithmetic  

E-print Network

Monte Carlo Arithmetic: exploiting randomness in floating Abstract Monte Carlo Arithmetic (MCA) is an extension of standard floating-point * *arithmetic that exploits randomness in basic floating-point operations. MCA includes rando* *m rounding _ which

Parker, D. Stott

271

33 CFR 143.120 - Floating OCS facilities.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Floating OCS facilities. 143.120 Section...EQUIPMENT OCS Facilities 143.120 Floating OCS facilities. (a) Before construction is started on a proposed floating OCS facility, the owner...

2014-07-01

272

Smooth Planning for Free-floating Space Robots Using Polynomials *  

E-print Network

Smooth Planning for Free-floating Space Robots Using Polynomials * Evangelos Papadopoulos, Ioannis) is acknowledged. Abstract Free-floating space manipulator systems, have spacecraft actuators turned off freefloating space manipulator systems is developed that allows simultaneous manipulator end

Papadopoulos, Evangelos

273

4.2: Design of an Improved Pixel for a Polysilicon Active Matrix Organic Light Emitting Diode Display  

E-print Network

4.2: Design of an Improved Pixel for a Polysilicon Active Matrix Organic Light Emitting Diode active matrix organic light emitting diode (AMOLED) pixel with high pixel to pixel luminance uniformity such as organic light emitting diodes (OLEDs) are presently of great interest due to their potential application

274

High performance reconfigurable floating-point arithmetic modules  

Microsoft Academic Search

This paper presents the design, optimization and implementation of floating- point arithmetic modules on FPGA to be used in DSP appkications. These modules are floating-point multiplier, floating-point adderhbtractor, floating-point complex multiplier, floating-point complex adder\\/subtractor and floating-point multiplier-accumulator (MAC). The simulation and the Synthesis results for these modules are provided. All the modules presented in this paper support creation of custom

Ghd A. Aty; I. S. Ashour; M. Mones

2005-01-01

275

Temperature and light effects on the circadian rhythm and locomotory activity of the plains garter snake (Thamnophis radix hayendi)  

Microsoft Academic Search

The Locomotory activity of the Plains Garter snake was determined under L\\/D: 12\\/12 conditions at five constant temperatures and three light intensities during the light period. The snakes were diurnal at low temperatures with nocturnal activity increasing in various amounts at higher temperatures. The different light intensities had relatively small effects on the activity rhythm.Activity was recorded under four constant

C. Heckrotte

1975-01-01

276

A light-inducible CRISPR-Cas9 system for control of endogenous gene activation.  

PubMed

Optogenetic systems enable precise spatial and temporal control of cell behavior. We engineered a light-activated CRISPR-Cas9 effector (LACE) system that induces transcription of endogenous genes in the presence of blue light. This was accomplished by fusing the light-inducible heterodimerizing proteins CRY2 and CIB1 to a transactivation domain and the catalytically inactive dCas9, respectively. The versatile LACE system can be easily directed to new DNA sequences for the dynamic regulation of endogenous genes. PMID:25664691

Polstein, Lauren R; Gersbach, Charles A

2015-03-01

277

Hydroelastic analysis of a large floating structure  

Microsoft Academic Search

An analytical approach to predict the bending vibration of a very large floating structure of thin and elongated rectangular plate configuration, floating on water of shallow depth and under the action of a monochromatic head wave, is presented. The horizontal size of the plate is huge compared with the wavelength of the incident waves, yet the wavelength is much larger

M. Ohkusu; Y. Namba

2004-01-01

278

Future float zone development in industry  

NASA Technical Reports Server (NTRS)

The present industrial requirements for float zone silicon are summarized. Developments desired by the industry in the future are reported. The five most significant problems faced today by the float zone crystal growth method in industry are discussed. They are economic, large diameter, resistivity uniformity, control of carbon, and swirl defects.

Sandfort, R. M.

1980-01-01

279

Oxygen and silver diffusion into float glass  

Microsoft Academic Search

In the float glass process, molten glass is floated on a molten metallic tin bath, such that tin penetrates the glass surface. Consequently, the glass has distinctly two different faces; the tin-penetrated face (bottom face) and the opposite face (top face). In this paper, the effects of tin on oxygen and silver diffusion into the top and bottom faces of

Satoshi Takeda

2006-01-01

280

Floating plant dominance as a stable state  

Microsoft Academic Search

Invasion by mats of free-floating plants is among the most important threats to the functioning and biodiversity of freshwater ecosystems ranging from temperate ponds and ditches to tropical lakes. Dark, anoxic conditions under thick floating-plant cover leave little opportunity for animal or plant life, and they can have large negative impacts on fisheries and navigation in tropical lakes. Here, we

Marten Scheffer; Sndor Szab; Alessandra Gragnani; Egbert H. van Nes; Sergio Rinaldi; Nils Kautsky; Jon Norberg; Rudi M. M. Roijackers; Rob J. M. Franken

2003-01-01

281

IEEE Standard unifies arithmetic model Floating points  

E-print Network

years use IEEE floating-point arithmetic. This doesn't mean that they all get exactly the same resultsIEEE Standard unifies arithmetic model Floating points by Cleve Moler C l e v e ' s C o r n e r I f you look carefully at the definition of fundamental arithmetic operations like addition

Beron-Vera, Francisco Javier

282

Vertical pump with free floating check valve  

DOEpatents

A vertical pump with a bottom discharge having a free floating check valve isposed in the outlet plenum thereof. The free floating check valve comprises a spherical member with a hemispherical cage-like member attached thereto which is capable of allowing forward or reverse flow under appropriate conditions while preventing reverse flow under inappropriate conditions.

Lindsay, Malcolm (O'Hara Township, Allegheny County, PA)

1980-01-01

283

Pattern of stylet penetration activity by Homalodisca vitripennis (Hemiptera: Cicadellidae) adults in relation to environmental temperature and light conditions  

Technology Transfer Automated Retrieval System (TEKTRAN)

Effects of ambient spring air temperature and light intensity on stylet penetration activities of the glassy-winged sharpshooter, Homalodisca vitripennis (Germar) were studied outdoors, at ambient light and temperatures, using an electrical penetration graph (EPG). EPG waveforms representing saliva...

284

A novel control process of cyanobacterial bloom using cyanobacteriolytic bacteria immobilized in floating biodegradable plastic carriers  

Microsoft Academic Search

A process using a floating carrier for immobilization of cyanobacteriolytic bacteria, B.cereus N?14, was proposed to realize an effective in situ control of natural floating cyanobacterial blooms. The critical concentrations of the cyanobacteriolytic substance and B.cereus N?14 cells required to exhibit cyanobacteriolytic activity were investigated. The results indicated the necessity of cell growth to produce sufficiently high amounts of the

N. Nakamura; K. Nakano; N. Sugiura; M. Matsumura

2003-01-01

285

Red Light Regulates Calcium-Activated Potassium Channels in Mougeotia Plasma Membrane 1  

PubMed Central

The alga Mougeotia has a large central chloroplast whose positioning is regulated by photoactivation of phytochrome, possibly via modulation of cytosolic calcium (Serlin B, Roux SJ [1984] Proc Natl Acad Sci USA 81: 6368-6372). We used the patch clamp technique to examine the effects of red and far-red light on ion channel activity in the plasma membrane of Mougeotia protoplasts to determine if ion channels play a role in chloroplast movement. Patch clamping in the cell-attached mode reveals two channels of about 2 and 4 picoamperes amplitude at 0 millivolt (inside pipette) and estimated conductances of 30 and 65 picosiemens. They are activated by red light irradiation after a lag period of about 2 to 5 minutes. Far-red light, when applied immediately after red light irradiation, reverses this activation; otherwise it has no effect. This result implicates phytochrome. The addition of the calcium ionophore, A23187, also activates ion channel activity after a lag of a few minutes. The channels are not specific for calcium since they are present when calcium is removed from the external and pipette media. They are inhibited by quaternary ammonium ions. Thus, we believe they are calcium-activated potassium channels. Their possible role in chloroplast positioning is discussed. PMID:16667355

Lew, Roger R.; Serlin, Bruce S.; Schauf, Charles L.; Stockton, Marsha E.

1990-01-01

286

Floating plant dominance as a stable state  

PubMed Central

Invasion by mats of free-floating plants is among the most important threats to the functioning and biodiversity of freshwater ecosystems ranging from temperate ponds and ditches to tropical lakes. Dark, anoxic conditions under thick floating-plant cover leave little opportunity for animal or plant life, and they can have large negative impacts on fisheries and navigation in tropical lakes. Here, we demonstrate that floating-plant dominance can be a self-stabilizing ecosystem state, which may explain its notorious persistence in many situations. Our results, based on experiments, field data, and models, represent evidence for alternative domains of attraction in ecosystems. An implication of our findings is that nutrient enrichment reduces the resilience of freshwater systems against a shift to floating-plant dominance. On the other hand, our results also suggest that a single drastic harvest of floating plants can induce a permanent shift to an alternative state dominated by rooted, submerged growth forms. PMID:12634429

Scheffer, Marten; Szab, Sndor; Gragnani, Alessandra; van Nes, Egbert H.; Rinaldi, Sergio; Kautsky, Nils; Norberg, Jon; Roijackers, Rudi M. M.; Franken, Rob J. M.

2003-01-01

287

Floating plant dominance as a stable state.  

PubMed

Invasion by mats of free-floating plants is among the most important threats to the functioning and biodiversity of freshwater ecosystems ranging from temperate ponds and ditches to tropical lakes. Dark, anoxic conditions under thick floating-plant cover leave little opportunity for animal or plant life, and they can have large negative impacts on fisheries and navigation in tropical lakes. Here, we demonstrate that floating-plant dominance can be a self-stabilizing ecosystem state, which may explain its notorious persistence in many situations. Our results, based on experiments, field data, and models, represent evidence for alternative domains of attraction in ecosystems. An implication of our findings is that nutrient enrichment reduces the resilience of freshwater systems against a shift to floating-plant dominance. On the other hand, our results also suggest that a single drastic harvest of floating plants can induce a permanent shift to an alternative state dominated by rooted, submerged growth forms. PMID:12634429

Scheffer, Marten; Szabo, Sandor; Gragnani, Alessandra; Van Nes, Egbert H; Rinaldi, Sergio; Kautsky, Nils; Norberg, Jon; Roijackers, Rudi M M; Franken, Rob J M

2003-04-01

288

Visible light photocatalytic activity of TiO2 nanoparticles hybridized by conjugated derivative of polybutadiene  

NASA Astrophysics Data System (ADS)

A series of conjugated polymer/TiO2 (CP/TiO2) nanocomposites were prepared from TiO2 and commercial polybutadiene. The as-prepared CP/TiO2 nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), Raman Spectroscopy, UV-vis diffuse reflectance spectroscopy (UV-vis DRS), and X-ray photoelectron spectroscopy (XPS). The photocatalytic activities of CP/TiO2 nanocomposites were investigated by monitoring the degradation of methyl orange aqueous solution under visible light irradiation. The effects of preparation conditions (such as the mass ratio of PB to TiO2 in suspensions for PB/TiO2 preparation, heat-treatment temperature and time) of CP/TiO2 nanocomposites on their visible light photocatalytic activity were investigated. The results show that the CP/TiO2 nanocomposites have excellent visible light photocatalytic activity. As the content of conjugated polymer on the TiO2 surface, heat-treatment temperature and time increase, the visible light photocatalytic activity increases at first and then decreases. The visible light photocatalytic mechanism of the CP/TiO2 nanocomposites has been discussed.

Liu, Guoquan; Liu, Longchen; Song, Jinran; Liang, Jiudi; Luo, Qingzhi; Wang, Desong

2014-05-01

289

Enhanced photosynthetic activity in Spinacia oleracea by spectral modification with a photoluminescent light converting material.  

PubMed

The spectral conversion of incident sunlight by appropriate photoluminescent materials has been a widely studied issue for improving the efficiency of photovoltaic solar energy harvesting. By using phosphors with suitable excitation/emission properties, also the light conditions for plants can be adjusted to match the absorption spectra of chlorophyll dyes, in this way increasing the photosynthetic activity of the plant. Here, we report on the application of this principle to a high plant, Spinacia oleracea. We employ a calcium strontium sulfide phosphor doped with divalent europium (Ca0.4Sr0.6S:Eu(2+), CSSE) on a backlight conversion foil in photosynthesis experiments. We show that this phosphor can be used to effectively convert green to red light, centering at a wavelength of ~650 nm which overlaps the absorption peaks of chlorophyll a/b pigments. A measurement system was developed to monitor the photosynthetic activity, expressed as the CO2 assimilation rate of spinach leaves under various controlled light conditions. Results show that under identical external light supply which is rich in green photons, the CO2 assimilation rate can be enhanced by more than 25% when the actinic light is modified by the CSSE conversion foil as compared to a purely reflecting reference foil. These results show that the phosphor could be potentially applied to modify the solar spectrum by converting the green photons into photosynthetically active red photons for improved photosynthetic activity. PMID:24514932

Xia, Qi; Batentschuk, Miroslaw; Osvet, Andres; Richter, Peter; Hder, Donat P; Schneider, Juergen; Brabec, Christoph J; Wondraczek, Lothar; Winnacker, Albrecht

2013-11-01

290

Light-activation through indirect ceramic restorations: does the overexposure compensate for the attenuation in light intensity during resin cement polymerization?  

PubMed Central

Objectives This study evaluated the effects of light exposure through simulated indirect ceramic restorations (SICR) on hardness (KHN) of dual-cured resin cements (RCs), immediately after light-activation and 24 h later. Material and Methods Three dual-cured RCs were evaluated: eco-Link (Ivoclar Vivadent), Rely X ARC (3M eSPe), and Panavia F (Kuraray Medical Inc.). The RCs were manipulated in accordance to the manufacturers instructions and were placed into cylindrical acrylic matrixes (1-mm-thick and 4-mm diameter). The RC light-activation (Optilux 501; Demetron Kerr) was performed through a glass slide for 120 s (control group), or through 2-mm or 4-mm thick SICRs (IPS empress II; Ivoclar Vivadent). The specimens were submitted to KHN analysis immediately and 24 h after light-activation. The data obtained at the 2 evaluation intervals were submitted to 2-way ANOVA repeated measures and post-hoc Tukeys test (pre-set alpha of 5%). Results Lower KHN was observed when light-activation was performed through SICRs for eco-Link at all evaluation intervals and for Rely X ARC 24 h later. For Panavia F, no significant difference in KHN was observed between control and experimental groups, regardless of evaluation interval. Most groups exhibited higher KHN after 24 h than immediately after light-activation, with the exception of Rely X ARC light-activated through SICR, as no significant difference in KHN was found between evaluation intervals. Conclusion Light overexposure did not compensate for light intensity attenuation due to the presence of SICR when Rely X and eco-Link were used. Although hardness of such RCs increased over a 24-h interval, the RCs subjected to light overexposure did not reach the hardness values exhibited after direct light exposure. PMID:21437465

BUENO, Albano Luis Novaes; ARRAIS, Cesar Augusto Galvo; JORGE, Ana Carolina Tedesco; REIS, Andre Figueiredo; AMARAL, Cristiane Mariote

2011-01-01

291

Development and Progress in Enabling the Photocatalyst Ti02 Visible-Light-Active  

NASA Technical Reports Server (NTRS)

Photocatalytic oxidation (PCO) of organic contaminants is a promising air and water quality management approach which offers energy and cost savings compared to thermal catalytic oxidation (TCO). The most widely used photocatalyst, anatase TiO2, has a wide band gap (3.2 eV) and is activated by UV photons. Since solar radiation consists of less than 4% UV, but contains 45% visible light, catalysts capable of utilizing these visible photons need to be developed to make peo approaches more efficient, economical, and safe. Researchers have attempted various approaches to enable TiO2 to be visible-light-active with varied degrees of success'. Strategies attempted thus far fall into three categories based on their electrochemical' mechanisms: 1) narrowing the band gap of TiO2 by implantation of transition metal elements or nonmetal elements such as N, S, and C, 2) modifying electron-transfer processes during PCO by adsorbing sensitizing dyes, and 3) employing light-induced interfacial electron transfer in the heteronanojunction systems consisting of narrow band gap semiconductors represented by metal sulfides and TiO2. There are diverse technical approaches to implement each of these strategies. This paper presents a review of these approaches and results of the photocatalytic activity and photonic efficiency of the end .products under visible light. Although resulting visible-light-active (VLA) photocatalysts show promise, there is often no comparison with unmodified TiO2 under UV. In a limited number of studies where such comparison was provided, the UV-induced catalytic activity of bare TiO2 is much greater than the visible-light-induced catalytic activity of the VLA catalyst. Furthermore, VLA-catalysts have much lower quantum efficiency compared to the approx.50% quantum efficiency of UV-catalysts. This stresses the need for continuing research in this area.

Levine, Lanfang H.; Coutts, Janelle L.; Clausen, Christian A.

2011-01-01

292

Light limitation of photosynthesis and activation of ribulose bisphosphate carboxylase in wheat seedlings  

PubMed Central

In limiting light the activation of ribulose-1,5-bisphosphate (RuP2) carboxylase [3-phospho-D-glycerate carboxylyase (dimerizing), EC 4.1.1.39] in leaf extracts of 7- to 8-day-old wheat seedlings changed proportionally with the photosynthetic rate of the intact plants. Higher rates of photosynthesis, induced by increasing irradiances, were accompanied by an increase in activation of the leaf RuP2 carboxylase, while RuP2 levels remained unchanged. The degree of activation varied from 20% to 60% of full activation at irradiances of 225-1650 ?E/m2s (photosynthetically active radiation; E = einstein, 1 mol of photons). Between 225 ?E/m2s and darkness, activation approached 50% while RuP2 levels dropped more than 90%. During steady-state photosynthesis, levels of the substrate RuP2 were 250-300 nmol/mg of chlorophyll in the leaves and were similar at all irradiances above 225 ?E/m2s (25% of light saturation). When velocities of the carboxylase in leaf extracts were corrected for CO2 levels estimated to exist within the leaf, they compared favorably with the photosynthetic rates of the intact seedlings. Comparison of CO2 exchange rate, RuP2 level, and activation of the carboxylase indicates that light limitation of photosynthesis can be due to two factors: the availability of RuP2 in dark to dim light and activation of the RuP2 carboxylase in dim light and higher irradiances. PMID:16593018

Perchorowicz, John T.; Raynes, Deborah A.; Jensen, Richard G.

1981-01-01

293

Energization and Activation of Inorganic Carbon Uptake by Light in Cyanobacteria 1  

PubMed Central

The requirement of the inorganic carbon (Ci) transport system for light in cyanobacteria was investigated in Anabaena variabilis by the filtering centrifugation technique and in a mutant (E1) isolated from Anacystis nidulans using a gas exchange system. Ci transport capability increased with time of preillumination and decreased following darkening. Full activity could not be obtained by operating either photosystem II (PSII) or photosystem I alone. 3(3,4 Dichlorophenyl)-1,1 dimethylurea strongly inhibited Ci uptake. Very low activity of PSII was sufficient to activate Ci uptake. However, in the presence of dithiothreitol PSII activity was not required. We conclude that light may be required to activate as well as to energize Ci uptake in cyanobacteria. PMID:16665418

Kaplan, Aaron; Zenvirth, Drora; Marcus, Yehouda; Omata, Tatsuo; Ogawa, Teruo

1987-01-01

294

The Effect of Multiple Sequential Light Sources to Activate Aminolevulinic Acid in the Treatment of Actinic Keratoses: A Retrospective Study  

PubMed Central

There is a lack of research regarding the sequential use of multiple light sources for topical 5-aminolevulinic acid activation in photodynamic therapy for actinic keratosis. This study evaluated 5-aminolevulinic acid-photodynamic therapy for actinic keratosis using blue light combined with red light, pulsed dye laser, and/or intense pulsed light in a retrospective fashion. Field-directed 5-aminolevulinic acid-photodynamic therapy was performed with blue light only, blue light + pulsed dye laser, blue light + intense pulsed light, blue light + pulsed dye laser + intense pulsed light, or blue light + red light + pulsed dye laser + intense pulsed light for nonhyperkeratotic actinic keratoses of face, scalp, or upper trunk. Blue light + intense pulsed light + pulsed dye laser produced greater patient-reported improvement in actinic keratoses than blue light or blue light + intense pulsed light and greater subject-reported improvement in overall skin quality than blue light + intense pulsed light. The addition of red light led to no further benefit in either outcome measure. Photodynamic therapy with multiple, sequential laser and light sources led to greater patient-graded improvement in actinic keratoses than that with a single light source (blue light), without significant differences in post-treatment adverse events. However, the small, widely disparate number of patients between groups and follow-up times between patients, as well as retrospective assessments based on subjective patient recall, severely limit the significance of these findings. Nevertheless, the results raise interesting questions regarding the use of multiple light and laser sources for photodynamic therapy of actinic keratoses and warrant further research with a prospective, randomized, controlled study. PMID:25276272

Goldman, Mitchel P.; Fabi, Sabrina G.; Guiha, Isabella

2014-01-01

295

Comparison of self-cleaning properties of three titania coatings on float glass  

NASA Astrophysics Data System (ADS)

This work compares the self-cleaning properties of experimental TiO2 and TiO2-Ag coatings on float glass with a commercial self-cleaning glass. In the experimental surfaces, TiO2 coating was applied to float glass via the sol-gel route, while TiO2-Ag coating was applied by the liquid flame spray method, which deposits TiO2-Ag composite nanoparticles on the surface. The effect of the coatings on the surface wettability and the activation time for achieving hydrophilicity was studied through water contact angle as a function of exposure time to UV light. The surface morphology was investigated by using scanning electron microscopy (SEM) and confocal optical microscopy. The photocatalytic activity of the coatings was examined with methylene blue and stearic acid degradation tests. Finally, the soil attachment to the surfaces was tested with a sebum-based model soil. The sol-gel TiO2 coating became superhydrophilic within a few hours, while the activation time needed for the commercial titania coated glass was several days. The surface with the TiO2-Ag nanoparticles did not show any marked changes in the water contact angle. The commercial titania coated and the sol-gel TiO2 surfaces showed self-cleaning properties and clearly lower attachment of soil than the uncoated and TiO2-Ag coated surfaces. The difference in the interaction of the surfaces with the organic contaminants was assumed to depend mainly on differences in the thickness of the coatings.

Piispanen, Minna; Hupa, Leena

2011-11-01

296

Effects of hydroxyl radical scavengers KCN and CO on ultraviolet light-induced activation of crude soluble guanylate cyclase  

SciTech Connect

The crude soluble guanylate cyclase (GC) from bovine mesenteric artery was stimulated by ultraviolet (UV) light (366 nm). Addition of free radical scavengers, dimethylsulfoxide or superoxide dismutase and/or catalase to the GC assay did not abolish the stimulatory effect of UV light. On the contrary, the UV light-induced activation was enhanced in the presence of these scavengers. KCN (1 mM) did not affect the UV light-induced activation, while 0.1 mM of CO potentiated the activation. These results may indicate that UV light is operating through a direct interaction with the ferrous form of the GC-heme.

Karlsson, J.O.; Axelsson, K.L.; Andersson, R.G.

1985-01-01

297

NSLS 2007 Activity Report (National Synchrotron Light Source Activity Report 2007)  

SciTech Connect

The National Synchrotron Light Source is one of the world's most productive and cost-effective user facilities. With 2,219 individual users, about 100 more than last year, and a record-high 985 publications, 2007 was no exception. In addition to producing an impressive array of science highlights, which are included in this Activity Report, many NSLS users were honored this year for their scientific accomplishments. Throughout the year, there were major strides in the development of the scientific programs by strengthening strategic partnerships with major research resources and with the Center for Functional Nanomaterials (CFN). Of particular note, the Consortium for Materials Properties Research in Earth Sciences (COMPRES) received renewed funding for the next five years through the National Science Foundation. COMPRES operates four high-pressure NSLS beamlines--X17B2, X17B3, X17C, and U2A--and serves the earth science community as well as the rapidly expanding segment of researchers using high-pressure techniques in materials, chemical, and energy-related sciences. A joint appointment was made between the NSLS and Stony Brook University to further enhance interactions with COMPRES. There was major progress on two key beamline projects outlined in the Five-Year Strategic Plan: the X25 beamline upgrade and the construction of the X9 small angle scattering (SAXS) beamline. The X25 overhaul, which began with the installation of the in-vacuum mini-gap undulator (MGU) in January 2006, is now complete. X25 is once again the brightest beamline for macromolecular crystallography at the NSLS, and in tandem with the X29 undulator beamline, it will keep the NSLS at the cutting edge in this important area of research. Upgrade work associated with the new MGU and the front end for the X9 SAXS beamline--jointly developed by the NSLS and the CFN--also was completed. Beamline X9 will host the SAXS program that currently exists at beamline X21 and will provide new microbeam SAXS capabilities and much-needed beam time for the life sciences, soft condensed matter physics, and nanoscience communities. Looking toward the future, a significant step has been made in expanding the user base and diversifying the work force by holding the first Historically Black Colleges and Universities (HBCU) Professors' Workshop. The workshop, which brought 11 professors to the NSLS to learn how to become successful synchrotron users, concluded with the formation of an HBCU User Consortium. Finally, significant contributions were made in optics and detector development to enhance the utilization of the NSLS and address the challenges of NSLS-II. In particular, x-ray detectors developed by the NSLS Detector Section have been adopted by an increasing number of research programs both at the NSLS and at light sources around the world, speeding up measurement times by orders of magnitude and making completely new experiments feasible. Significant advances in focusing and high-energy resolution optics have also been made this year.

Miller ,L.; Nasta, K.

2008-05-01

298

Near-infrared light controlled photocatalytic activity of carbon quantum dots for highly selective oxidation reaction  

NASA Astrophysics Data System (ADS)

Selective oxidation of alcohols is a fundamental and significant transformation for the large-scale production of fine chemicals, UV and visible light driven photocatalytic systems for alcohol oxidation have been developed, however, the long wavelength near infrared (NIR) and infrared (IR) light have not yet fully utilized by the present photocatalytic systems. Herein, we reported carbon quantum dots (CQDs) can function as an effective near infrared (NIR) light driven photocatalyst for the selective oxidation of benzyl alcohol to benzaldehyde. Based on the NIR light driven photo-induced electron transfer property and its photocatalytic activity for H2O2 decomposition, this metal-free catalyst could realize the transformation from benzyl alcohol to benzaldehyde with high selectivity (100%) and conversion (92%) under NIR light irradiation. HO&z.rad; is the main active oxygen specie in benzyl alcohol selective oxidative reaction confirmed by terephthalic acid photoluminescence probing assay (TA-PL), selecting toluene as the substrate. Such metal-free photocatalytic system also selectively converts other alcohol substrates to their corresponding aldehydes with high conversion, demonstrating a potential application of accessing traditional alcohol oxidation chemistry.Selective oxidation of alcohols is a fundamental and significant transformation for the large-scale production of fine chemicals, UV and visible light driven photocatalytic systems for alcohol oxidation have been developed, however, the long wavelength near infrared (NIR) and infrared (IR) light have not yet fully utilized by the present photocatalytic systems. Herein, we reported carbon quantum dots (CQDs) can function as an effective near infrared (NIR) light driven photocatalyst for the selective oxidation of benzyl alcohol to benzaldehyde. Based on the NIR light driven photo-induced electron transfer property and its photocatalytic activity for H2O2 decomposition, this metal-free catalyst could realize the transformation from benzyl alcohol to benzaldehyde with high selectivity (100%) and conversion (92%) under NIR light irradiation. HO&z.rad; is the main active oxygen specie in benzyl alcohol selective oxidative reaction confirmed by terephthalic acid photoluminescence probing assay (TA-PL), selecting toluene as the substrate. Such metal-free photocatalytic system also selectively converts other alcohol substrates to their corresponding aldehydes with high conversion, demonstrating a potential application of accessing traditional alcohol oxidation chemistry. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr00092c

Li, Haitao; Liu, Ruihua; Lian, Suoyuan; Liu, Yang; Huang, Hui; Kang, Zhenhui

2013-03-01

299

Ultra-Thin Floating Mirrors  

E-print Network

We discuss a new technology that promises large inexpensive mirrors. We argue that it should be possible to tilt a rotating viscous liquid by perhaps as much as a few tens of degrees. The tilted liquid parabolic surface is used as the support for a thin reflecting metallic film. We demonstrate two critical steps: that a viscous liquid mirror can be tilted and that an optical quality metallic film can be deposited on a liquid. The advent of astronomically useful tilted floating mirror telescopes is contingent on the development of high-viscosity high-reflectivity liquids. It is a good omen that we already have identified two classes of such liquids; however there remain technical challenges to overcome before such liquids can be used in viable telescopes.

Ermanno F. Borra; Anna Ritcey; Etienne Artigau

1999-01-19

300

Float polishing of optical materials.  

PubMed

The float-polishing technique has been studied to determine its suitability for producing supersmooth surfaces on optical materials, yielding a roughness of <2 A rms. An attempt was made to polish six different materials including fused quartz, Zerodur, and sapphire. The low surface roughness was achieved on fused quartz, Zerodur, and Corning experimental glass-ceramic materials, and a surface roughness of <1 A rms was obtained on O-cut single-crystal sapphire. Presumably, similar surface finishes can also be obtained on CerVit and ULE quartz, which could not be polished satisfactorily in this set of experiments because of a mismatch between sample mounting and machine configuration. PMID:20454201

Bennett, J M; Shaffer, J J; Shibano, Y; Namba, Y

1987-02-15

301

New light sources and sensors for active optical 3D inspection  

NASA Astrophysics Data System (ADS)

The implementation of active processing strategies in optical 3D-inspection needs the availability of flexible hardware solutions. The system components illumination and sensor/detector are actively involved in the processing chain by a feedback loop that is controlled by the evaluation process. Therefore this article deals with new light sources and sensor which appeared recently on the market and can be applied successfully for the implementation of active processing principles. Some applications where such new components are used to implement an active measurement strategy are presented.

Osten, Wolfgang; Jueptner, Werner P. O.

1999-11-01

302

Extended Onshore Control of a Floating Wind Turbine with Wave Disturbance Reduction  

NASA Astrophysics Data System (ADS)

Reaching for higher wind resources beyond the water depth limitations of monopile wind turbines, there has arisen the alternative of using floating wind turbines. But the response of wave induced loads significantly increases for floating wind turbines. Applying conventional onshore control strategies to floating wind turbines has been shown to impose negative damped oscillations in fore-aft due to the low natural frequency of the floating structure. Thus, we suggest a control loop extension of the onshore controller which stabilizes the system and reduces the wave disturbance. The results shows that when adding the suggested control loop with disturbance reduction to the system, improved performance is observed in power fluctuations, blade pitch activity, and platform oscillations.

Christiansen, S.; Knudsen, T.; Bak, T.

2014-12-01

303

WindWaveFloat Final Report  

SciTech Connect

Principle Power Inc. and National Renewable Energy Lab (NREL) have completed a contract to assess the technical and economic feasibility of integrating wave energy converters into the WindFloat, resulting in a new concept called the WindWaveFloat (WWF). The concentration of several devices on one platform could offer a potential for both economic and operational advantages. Wind and wave energy converters can share the electrical cable and power transfer equipment to transport the electricity to shore. Access to multiple generation devices could be simplified, resulting in cost saving at the operational level. Overall capital costs may also be reduced, provided that the design of the foundation can be adapted to multiple devices with minimum modifications. Finally, the WindWaveFloat confers the ability to increase energy production from individual floating support structures, potentially leading to a reduction in levelized energy costs, an increase in the overall capacity factor, and greater stability of the electrical power delivered to the grid. The research conducted under this grant investigated the integration of several wave energy device types into the WindFloat platform. Several of the resulting system designs demonstrated technical feasibility, but the size and design constraints of the wave energy converters (technical and economic) make the WindWaveFloat concept economically unfeasible at this time. Not enough additional generation could be produced to make the additional expense associated with wave energy conversion integration into the WindFloat worthwhile.

Alla Weinstein, Dominique Roddier, Kevin Banister

2012-03-30

304

Treatment of actinic cheilitis by photodynamic therapy with 5-aminolevulinic acid and blue light activation.  

PubMed

Actinic cheilitis (AC), a common disorder of the lower lip, should be treated early to prevent progression to invasive squamous cell carcinoma. This study evaluated the safety and efficacy of photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA) activated by blue light for the treatment of AC. Fifteen patients with clinically evident or biopsy-proven AC received two treatments with ALA PDT with blue light activation. Treatments were spaced three to five weeks apart. Most patients achieved 65% to 75% clearance three to five weeks after the first treatment and all achieved more than 75% clearance one month after the second treatment. Three patients achieved complete clearance. Pain and burning during irradiation were absent or mild. All patients said they would repeat the procedure. ALA PDT with 417 nm blue light is a promising option for the treatment of AC of the lower lip. PMID:22052302

Zaiac, Martin; Clement, Annabelle

2011-11-01

305

Vanadium pentoxide modified polycrystalline silicon anode for active-matrix organic light-emitting diodes  

E-print Network

to be an efficient anode for organic light-emitting diode OLED X. L. Zhu, J. X. Sun, H. J. Peng, Z. G. Meng, M. Wong an ultrathin vanadium pentoxide V2O5 layer on the p-Si anode, the performance of the OLED can be greatly with the active p-Si layer of thin-film transistors in active-matrix OLED displays. © 2005 American Institute

306

Enhanced light microscopic visualization of oxidase activity with the cerium capture method  

Microsoft Academic Search

Visualization methods for the light microscopic detection of the activity of oxidases after being localized with cerium ions as reported by Angermller and Fahimi (1988a, b) are not suitable for the demonstration of H2O2-genrating oxidases at sites with low activity. Therefore, the cerium-diaminobenzidine (DAB) visualization procedure of these authors was modified. Nickel or cobalt ions were added to the DAB

R. Gossrau; C. J. F. Noorden; W. M. Frederiks

1989-01-01

307

Transparent Active Matrix Organic Light-Emitting Diode Displays Driven by  

E-print Network

for the OLED pixels, higher than that required for liquid-crystal display (LCD) elements, in the 1­5 µ have steadily advanced in performance for flat panel display applications.2­4 Among currentTransparent Active Matrix Organic Light-Emitting Diode Displays Driven by Nanowire Transistor

Zhou, Chongwu

308

Optics: Light, Color, and Their Uses. An Educator's Guide With Activities In Science and Mathematics  

NASA Technical Reports Server (NTRS)

This document includes information on the Chandra X-Ray Observatory, the Hubble Space Telescope, the Next Generation Space Telescope, Soft X-Ray Imager, and the Lightning Imaging System. Classroom activities from grades K-12 are included, focusing on light and color, using mirrors, lenses, prisms, and filters.

2000-01-01

309

1994 Activity Report, National Synchrotron Light Source. Annual report, October 1, 1993-September 30, 1994  

SciTech Connect

This report is a summary of activities carried out at the National Synchrotron Light Source during 1994. It consists of sections which summarize the work carried out in differing scientific disciplines, meetings and workshops, operations experience of the facility, projects undertaken for upgrades, administrative reports, and collections of abstracts and publications generated from work done at the facility.

Rothman, E.Z. [ed.

1995-05-01

310

A Polysilicon Active Matrix Organic Light Emitting Diode Display with Integrated Drivers  

Microsoft Academic Search

The design of an active matrix organic light emitting diode (AMOLED) display using a polysilicon thin film transistor pixel is described. Characteristics of the OLED response in the low current regime are described and their impact on the design of integrated driver circuitry is discussed. Integrated data and select scanners which generate the signals necessary for data capture and pixel

R. M. A. Dawson; Z. Shen; D. A. Furst; S. Connor; J. Hsu; M. G. Kane; R. G. Stewart; A. Ipri; C. N. King; P. J. Green; R. T. Flegal; S. Pearson; W. A. Barrow; E. Dickey; K. Ping; S. Robinson; C. W. Tang; S. Van Slyke; C. H. Chen; J. Shi; M. H. Lu; M. Moskewicz; J. C. Sturm

1999-01-01

311

A new pixel circuit for active matrix organic light emitting diodes  

Microsoft Academic Search

We propose a new thin-film-transistor (TFT) pixel circuit for active-matrix organic light-emitting diode (AMOLED) composed of four TFTs and two capacitors. The simulation results, based on the device performances measured for an OLED and a poly-Si TFT, indicate that the proposed circuit has high immunity to the variation of poly-Si TFT characteristics

Joon-Chul Goh; Hoon-Ju Chung; Jin Jang; Chul-Hi Han

2002-01-01

312

Conformational changes in an ultrafast light-driven enzyme determine catalytic activity  

E-print Network

motions3­7 , it is almost impossible to distinguish between confor- mational changes and catalysis. We we study an enzyme from the family of alcohol dehydro- genases, NADPH of an activated enzyme conformation before catalysis. The requirement of light for initiation of catalysis by POR

van Stokkum, Ivo

313

The Examination of the Educational Effects of Some Writing Activities in the Light of Student Opinions  

ERIC Educational Resources Information Center

The aim of this research is to discover and compare the effects of writing prompt and expository writing from an educational perspective in the light of student opinions. The study was conducted according to qualitative research approach and content analysis was conducted. Two activities which were prepared with respect to objectives of writing

Ozturan Sagirli, Meryem

2010-01-01

314

Floating point arithmetic in future supercomputers  

NASA Technical Reports Server (NTRS)

Considerations in the floating-point design of a supercomputer are discussed. Particular attention is given to word size, hardware support for extended precision, format, and accuracy characteristics. These issues are discussed from the perspective of the Numerical Aerodynamic Simulation Systems Division at NASA Ames. The features believed to be most important for a future supercomputer floating-point design include: (1) a 64-bit IEEE floating-point format with 11 exponent bits, 52 mantissa bits, and one sign bit and (2) hardware support for reasonably fast double-precision arithmetic.

Bailey, David H.; Barton, John T.; Simon, Horst D.; Fouts, Martin J.

1989-01-01

315

Effectiveness of Mechanical Aerationin Floating Aquatic Macrophyte-Based Wastewater Treatment Systems  

E-print Network

Effectiveness of Mechanical Aerationin Floating Aquatic Macrophyte-Based Wastewater Treatment to evaluate its effect on wastewater treatment effi- ciency andplantgrowth. Light aeration (0.003 and0.021Lnr2 tanks. Heavy aeration (1.03 and 3.53 L nr2 min-1 ) raised wastewater dissolved oxygen(DO) concentrations

Florida, University of

316

A device to improve the SNR of the measurement of the positional floating reference point  

NASA Astrophysics Data System (ADS)

Previous studies have preliminarily validated the floating reference method and shown that it has the potential to improve the accuracy of non-invasive blood glucose sensing by Near-Infrared Spectroscopy. In order to make this method practical, it is necessary to precisely verify and measure the existence and variation features of the positional floating reference point. In this talk, a device which can precisely verify and measure the positional floating reference point is built. Since the light intensity of diffuse reflectance from the tested sample is very weak, a multipath detecting fibers system was built to improve signal-to-noise ratio. In this system, the fibers encircle the light source fiber which is regarded as the reference center of detecting fibers while they are moving. In addition, the position of each fiber is accurately controlled by manual translation stage to keep all detecting fibers always in the same radius around light source fiber. This ensures that received signal is coming from the same radial distance of light source. The variation of signal-to-noise ratio along with the different radial distance was investigated based on experiments. Results show that the application of this device could improve signal-to-noise ratio, and provide a new experimental method for the further study of positional floating reference point.

Jiang, Jingying; Rong, Xuzheng; Zhang, Hao; Xu, Kexin

2013-02-01

317

Characterization of spiral inductors with patterned floating structures  

Microsoft Academic Search

The impact of two different types of floating patterns on spiral inductors was investigated. Both patterned trench isolation with a floating p\\/n junction and floating metal poles were implemented underneath reference spiral inductors. All three types of inductors have an identical spiral geometry. Combination of patterned trench isolation with a floating p\\/n junction increases maximum quality factor (Qmax) by 17%

Chiaming Alex Chang; Sung-Pi Tseng; Jun Yi Chuang; Shiue-Shr Jiang; J. Andrew Yeh

2004-01-01

318

Floating-Point Arithmetic Nicolas Brisebarre Florent de Dinechin  

E-print Network

Floating-Point Arithmetic Nicolas Brisebarre Florent de Dinechin Claude-Pierre Jeannerod Vincent-slash and floating-slash number systems [26], 2-adic numbers [41]. And yet, floating-point arithmetic is by far and implementation, and mem- ory. It appears that floating-point arithmetic, with adequately chosen param- eters

Muller, Jean-Michel

319

Doing it without Floating Real and Solid Computing  

E-print Network

Doing it without Floating Real and Solid Computing Abbas Edalat #12;Overview · Floating Point) #12;Modern Computers: Floating Point Numbers · Any other number like is rounded or approximated to a close floating point number. 51 10817310. ?± · Represents only a finite collection of numbers. Sign ± 5

Edalat, Abbas

320

Some thoughts on characteristics of floats in network planning  

Microsoft Academic Search

Network is to design plans by means of network analysis, which is an effective method developed to make schedule plans for large scale projects in the end of 1950s. CPM is one of the main contents in network, and float is the main part. There are nine basic concepts, including total float, front single float, back single float, front common

Xiuhua Zhao; Jianxun Qi; Shisen Lv

2010-01-01

321

Optimization of Automated Float Glass Lines Byungsoo Na, Shabbir Ahmed  

E-print Network

Optimization of Automated Float Glass Lines Byungsoo Na, Shabbir Ahmed , George Nemhauser and Joel flat glass products being manufactured on float glass lines. New technologies are allowing float glass our methods are currently being implemented at a major float glass manufacturer. Abstract In automated

Ahmed, Shabbir

322

Program Converts VAX Floating-Point Data To UNIX  

NASA Technical Reports Server (NTRS)

VAX Floating Point to Host Floating Point Conversion (VAXFC) software converts non-ASCII files to unformatted floating-point representation of UNIX machine. This is done by reading bytes bit by bit, converting them to floating-point numbers, then writing results to another file. Useful when data files created by VAX computer must be used on other machines. Written in C language.

Alves, Marcos; Chapman, Bruce; Chu, Eugene

1996-01-01

323

14 CFR 27.751 - Main float buoyancy.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Main float buoyancy. 27.751 Section 27.751 Aeronautics...Floats and Hulls 27.751 Main float buoyancy. (a) For main floats, the buoyancy necessary to support the maximum weight...

2011-01-01

324

14 CFR 27.751 - Main float buoyancy.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Main float buoyancy. 27.751 Section 27.751 Aeronautics...Floats and Hulls 27.751 Main float buoyancy. (a) For main floats, the buoyancy necessary to support the maximum weight...

2012-01-01

325

14 CFR 29.751 - Main float buoyancy.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Main float buoyancy. 29.751 Section 29.751 Aeronautics...Floats and Hulls 29.751 Main float buoyancy. (a) For main floats, the buoyancy necessary to support the maximum weight...

2013-01-01

326

14 CFR 29.751 - Main float buoyancy.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Main float buoyancy. 29.751 Section 29.751 Aeronautics...Floats and Hulls 29.751 Main float buoyancy. (a) For main floats, the buoyancy necessary to support the maximum weight...

2012-01-01

327

14 CFR 27.751 - Main float buoyancy.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 2014-01-01 false Main float buoyancy. 27.751 Section 27.751 Aeronautics...Floats and Hulls 27.751 Main float buoyancy. (a) For main floats, the buoyancy necessary to support the maximum weight...

2014-01-01

328

14 CFR 29.751 - Main float buoyancy.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Main float buoyancy. 29.751 Section 29.751 Aeronautics...Floats and Hulls 29.751 Main float buoyancy. (a) For main floats, the buoyancy necessary to support the maximum weight...

2010-01-01

329

14 CFR 27.751 - Main float buoyancy.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Main float buoyancy. 27.751 Section 27.751 Aeronautics...Floats and Hulls 27.751 Main float buoyancy. (a) For main floats, the buoyancy necessary to support the maximum weight...

2013-01-01

330

14 CFR 27.751 - Main float buoyancy.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Main float buoyancy. 27.751 Section 27.751 Aeronautics...Floats and Hulls 27.751 Main float buoyancy. (a) For main floats, the buoyancy necessary to support the maximum weight...

2010-01-01

331

14 CFR 29.751 - Main float buoyancy.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 2014-01-01 false Main float buoyancy. 29.751 Section 29.751 Aeronautics...Floats and Hulls 29.751 Main float buoyancy. (a) For main floats, the buoyancy necessary to support the maximum weight...

2014-01-01

332

14 CFR 29.751 - Main float buoyancy.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Main float buoyancy. 29.751 Section 29.751 Aeronautics...Floats and Hulls 29.751 Main float buoyancy. (a) For main floats, the buoyancy necessary to support the maximum weight...

2011-01-01

333

Performance Boundaries of Massive Floating Car Data Offloading  

E-print Network

Performance Boundaries of Massive Floating Car Data Offloading Silvia Ancona1,3 and Razvan Stanica1Politecnico di Bari, Bari, Italy Floating Car Data (FCD) consist of information generated by moving vehicles networks, floating car data, cellular uplink 1 Introduction The term Floating Car Data (FCD) defines

Paris-Sud XI, Université de

334

Study on the activation of styrene-based shape memory polymer by medium-infrared laser light  

SciTech Connect

This paper demonstrates the feasibility of shape memory polymer (SMP) activation by medium-infrared laser light. Medium-infrared light is transmitted by an optical fiber embedded in the SMP matrix, and the shape recovery process and temperature distribution are recorded by an infrared camera. Light-induced SMP exhibits potential applications in biomedicines and flexible displays.

Leng Jinsong; Yu Kai; Lan Xin [Center for Composite Materials and Structures, Harbin Institute of Technology, HeiLongJiang 150001 (China); Zhang Dawei [Center for Composite Materials and Structures, Harbin Institute of Technology, HeiLongJiang 150001 (China); Material Science and Engineering College, Northeast Forestry University, HeiLongJiang 150040 (China); Liu Yanju [Department of Astronautical Science and Mechanics, Harbin Institute of Technology, HeiLongJiang 150001 (China)

2010-03-15

335

Oxygen deficient ZnO1-x nanosheets with high visible light photocatalytic activity.  

PubMed

Zinc oxide is one of the most important wide-band-gap (3.2 eV) materials with versatile properties, however, it can not be excited by visible light. In this work, we have developed an exquisite and simple way to prepare oxygen-deficient ZnO1-x nanosheets with a gray-colored appearance and excellent visible light photocatalytic activity. Detailed analysis based on UV-Vis absorption spectra, X-band electron paramagnetic resonance (EPR) spectra, and photoluminescence (PL) spectra confirms the existence of oxygen vacancies in ZnO1-x. The incorporation of oxygen defects could effectively extend the light absorption of ZnO1-x into the visible-light region due to the fact that the energy of the localized state is located in the forbidden gap. Thus, our obtained ZnO1-x shows a higher photodegradation of methyl orange (MO) compared to defect-free ZnO under visible light illumination. Additionally, the high content of ?OH radicals with a strong photo-oxidation capability over the ZnO1-x nanosheets significantly contributes to the improvement in the photocatalytic performance. Our oxygen deficient ZnO1-x sample shows a very high photocatalytic activity for the degradation of MO even after 5 cycles without any obvious decline. The results demonstrate that defect engineering is a powerful tool to enhance the optoelectronic and photocatalytic performances of nanomaterials. PMID:25812132

Guo, Hong-Li; Zhu, Qing; Wu, Xi-Lin; Jiang, Yi-Fan; Xie, Xiao; Xu, An-Wu

2015-04-01

336

Strategies of making TiO2 and ZnO visible light active.  

PubMed

In modern purification techniques employing semiconductor mediated photooxidation of toxic substances, zinc oxide (ZnO) and titanium dioxide (TiO2) are the most widely used metal oxides due to their unique blend of properties. However, the band edges of these semiconductors lie in the UV region which makes them inactive under visible light irradiation. Researchers have been interested in the modification of electronic and optical properties of these metal oxides for their efficient use in water and air purification under visible light irradiation. Visible light activity has been induced in TiO2 and ZnO by surface modification via organic materials/semiconductor coupling and band gap modification by doping with metals and nonmetals, co-doping with nonmetals, creation of oxygen vacancies and oxygen sub-stoichiometry. This paper encompasses the progress and developments made so far through these techniques in the visible light photocatalysis with TiO2 and ZnO. Recently, nitrogen doping in titania has been extensively carried out and therefore somewhat detailed discussion in this respect has been presented. Visible light activation of titania clusters encapsulated in zeolite-Y by nitrogen doping and incorporation of dye or organic sensitizers inside the zeolite framework, has also been highlighted in this review. PMID:19540666

Rehman, Shama; Ullah, Ruh; Butt, A M; Gohar, N D

2009-10-30

337

Light-triggered modulation of cellular electrical activity by ruthenium diimine nanoswitches.  

PubMed

Ruthenium diimine complexes have previously been used to facilitate light-activated electron transfer in the study of redox metalloproteins. Excitation at 488 nm leads to a photoexcited state, in which the complex can either accept or donate an electron, respectively, in the presence of a soluble sacrificial reductant or oxidant. Here, we describe a novel application of these complexes in mediating light-induced changes in cellular electrical activity. We demonstrate that RubpyC17 ([Ru(bpy)(2)(bpy-C17)](2+), where bpy is 2,2'-bipyridine and bpy-C17 is 2,2'-4-heptadecyl-4'-methyl-bipyridine), readily incorporates into the plasma membrane of cells, as evidenced by membrane-confined luminescence. Excitable cells incubated in RubpyC17 and then illuminated at 488 nm in the presence of the reductant ascorbate undergo membrane depolarization leading to firing of action potentials. In contrast, the same experiment performed with the oxidant ferricyanide, instead of ascorbate, leads to hyperpolarization. These experiments suggest that illumination of membrane-associated RubpyC17 in the presence of ascorbate alters the cell membrane potential by increasing the negative charge on the outer face of the cell membrane capacitor, effectively depolarizing the cell membrane. We rule out two alternative explanations for light-induced membrane potential changes, using patch clamp experiments: (1) light-induced direct interaction of RubpyC17 with ion channels and (2) light-induced membrane perforation. We show that incorporation of RubpyC17 into the plasma membrane of neuroendocrine cells enables light-induced secretion as monitored by amperometry. While the present work is focused on ruthenium diimine complexes, the findings point more generally to broader application of other transition metal complexes to mediate light-induced biological changes. PMID:23419103

Rohan, Joyce G; Citron, Y Rose; Durrell, Alec C; Cheruzel, Lionel E; Gray, Harry B; Grubbs, Robert H; Humayun, Mark; Engisch, Kathrin L; Pikov, Victor; Chow, Robert H

2013-04-17

338

Light-Triggered Modulation of Cellular Electrical Activity by Ruthenium Diimine Nanoswitches  

PubMed Central

Ruthenium diimine complexes have previously been used to facilitate light-activated electron transfer in the study of redox metalloproteins. Excitation at 488 nm leads to a photoexcited state, in which the complex can either accept or donate an electron, respectively, in the presence of a soluble sacrificial reductant or oxidant. Here, we describe a novel application of these complexes in mediating light-induced changes in cellular electrical activity. We demonstrate that RubpyC17 ([Ru(bpy)2(bpy-C17)]2+, where bpy is 2,2?-bipyridine and bpy-C17 is 2,2?-4-heptadecyl-4?-methyl-bipyridine), readily incorporates into the plasma membrane of cells, as evidenced by membrane-confined luminescence. Excitable cells incubated in RubpyC17 and then illuminated at 488 nm in the presence of the reductant ascorbate undergo membrane depolarization leading to firing of action potentials. In contrast, the same experiment performed with the oxidant ferricyanide, instead of ascorbate, leads to hyperpolarization. These experiments suggest that illumination of membrane-associated RubpyC17 in the presence of ascorbate alters the cell membrane potential by increasing the negative charge on the outer face of the cell membrane capacitor, effectively depolarizing the cell membrane. We rule out two alternative explanations for light-induced membrane potential changes, using patch clamp experiments: (1) light-induced direct interaction of RubpyC17 with ion channels and (2) light-induced membrane perforation. We show that incorporation of RubpyC17 into the plasma membrane of neuroendocrine cells enables light-induced secretion as monitored by amperometry. While the present work is focused on ruthenium diimine complexes, the findings point more generally to broader application of other transition metal complexes to mediate light-induced biological changes. PMID:23419103

2013-01-01

339

NSLS 2005 ACTIVITY REPORT (NATIONAL SYNCHROTRON LIGHT SOURCE ACTIVITY REPORT 2005).  

SciTech Connect

In 2005, the NSLS proved itself, once again, to be a center of scientific excellence. This remarkable facility, commissioned in the early 1980s, is still attracting some of the world's best researchers in almost every scientific field, who produce more than seven hundred scientific papers every year using the NSLS. The 'Science Highlights' and 'Feature Highlights' sections of this report are just a small sampling of the many, many impressive research projects conducted at the NSLS in 2005. For example, a user group synthesized and studied zinc-oxide nanowires, which have applications in many optical and electrical devices. Another user group studied how strontium and uranium are removed from high-level radioactive waste. And in another interesting study, users deciphered the basis for antibiotic resistance. However, as always, the success of these projects depends on the performance of the facility. Again this year, the rings were in top form--reliability was 96 percent for the x-ray ring and 99 percent for the VUV-IR ring. Additionally, to keep the NSLS as productive as possible and to continue to attract users, many beamline upgrade projects were completed this year. One of the highlights of these upgrades is the new mini-gap undulator installed at beamline X25. This insertion device is providing a much brighter x-ray source for the program at X25. In the always important area of safety, several noteworthy activities took place this year. In particular, NSLS staff made a major commitment to labeling and inspecting electrical equipment. And perhaps the best news is what didn't happen--there were no reportable occurrences related to environmental, safety, or health issues in 2005, and no injuries that resulted in restricted or lost time. We all owe thanks to the dedicated NSLS staff and users who have ensured that the NSLS remains a reliable, safe, up-to-date research facility. As 2005 came to an end, I stepped down as NSLS Chairman in order to focus my primary efforts on NSLS-II, the world-leading third-generation synchrotron planned for construction at BNL. NSLS-II passed a critical milestone in 2005 with the approval by the Department of Energy of CD-0. BNL has established the NSLS-II Project Organization within the Light Sources Directorate to put in place the management systems and infrastructure necessary to execute this complex undertaking. I will serve as NSLS-II Project Director and also retain my position as Associate Laboratory Director for Light Sources, with the NSLS reporting to me. Another exciting development is the planned establishment of the Joint Photon Sciences Institute (JPSI). JPSI will be devoted to cultivating and fostering collaborative, interdisciplinary R&D in areas of the physical sciences, engineering, and the life sciences that are united in employing synchrotron-based methods. JPSI will also develop new methods and applications that exploit the unique capabilities of NSLS-II and will serve as a gateway for NSLS-II users. JPSI will be a partnership between the Department of Energy and New York State, and I am delighted that New York State Governor George Pataki has pledged $30 million for the construction of the JPSI building. The building will be located adjacent to NSLS-II and will contain offices, meeting rooms, and specialized laboratories. The operating expenses of JPSI and funding for its research programs will be provided by the federal government. Until a permanent NSLS Director is selected, NSLS User Science Division Associate Chair Chi-Chang Kao will serve as the Interim NSLS Director. I couldn't be leaving the facility in more capable hands. Chi-Chang will lead NSLS staff and users this year in the development of a five-year strategic plan for the NSLS, scheduled for completion by the end of summer 2006. The plan will outline the course for the future operation and development of the NSLS, and will help ensure that the future of the NSLS remains as bright as its past.

MILLER, L. (EDITOR)

2006-05-01

340

A light-activated theranostic nanoagent for targeted macrophage ablation in inflammatory atherosclerosis.  

PubMed

The synthesis and utility of a multimodal theranostic nanoagent based upon magnetofluorescent nanoparticles for the treatment of inflammatory atherosclerosis is described. These particles are modified with near-infrared fluorophores and light-activated therapeutic moieties, which allow for the optical determination of agent localization and phototoxic activation at spectrally distinct wavelengths. The resulting agent is readily taken up by murine macrophages in vitro and is highly phototoxic, with an LD(50) of 430 pM. Intravenous administration results in the localization of the nanoagent within macrophage-rich atherosclerotic lesions that can be imaged by intravital fluorescence microscopy. Irradiation of the atheroma with 650 nm light activates the therapeutic component and results in eradication of inflammatory macrophages, which may induce lesion stabilization. Importantly, these agents display limited skin photosensitivity, are highly efficacious, and provide an integrated imaging and therapeutic nanoplatform for atherosclerosis. PMID:20721949

McCarthy, Jason R; Korngold, Ethan; Weissleder, Ralph; Jaffer, Farouc A

2010-09-20

341

Characterization of nucleoside triphosphatase activity in isolated pea nuclei and its photoreversible regulation by light  

NASA Technical Reports Server (NTRS)

A nucleoside triphosphatase (NTPase) present in highly purified preparations of pea nuclei was partially characterized. The activity of this enzyme was stimulated by divalent cations (Mg2+ = Mn2+ > Ca2+), but was not affected by the monovalent cations, Na+ and K+. The Mg(2+)-dependent activity was further stimulated by concentrations of Ca2+ in the low micromolar range. It could catalyze the hydrolysis of ATP, GTP, UTP, and CTP, all with a pH optimum of 7.5. The nuclear NTPase activity was not inhibited by vanadate, oligomycin, or nitrate, but was inhibited by relatively low concentrations of quercetin and the calmodulin inhibitor, compound 48/80. The NTPase was stimulated more than 50% by red light, and this effect was reversed by subsequent irradiation with far-red light. The photoreversibility of the stimulation indicated that the photoreceptor for this response was phytochrome, an important regulator of photomorphogenesis and gene expression in plants.

Chen, Y. R.; Roux, S. J.

1986-01-01

342

Human Cryptochrome-1 Confers Light Independent Biological Activity in Transgenic Drosophila Correlated with Flavin Radical Stability  

PubMed Central

Cryptochromes are conserved flavoprotein receptors found throughout the biological kingdom with diversified roles in plant development and entrainment of the circadian clock in animals. Light perception is proposed to occur through flavin radical formation that correlates with biological activity in vivo in both plants and Drosophila. By contrast, mammalian (Type II) cryptochromes regulate the circadian clock independently of light, raising the fundamental question of whether mammalian cryptochromes have evolved entirely distinct signaling mechanisms. Here we show by developmental and transcriptome analysis that Homo sapiens cryptochrome - 1 (HsCRY1) confers biological activity in transgenic expressing Drosophila in darkness, that can in some cases be further stimulated by light. In contrast to all other cryptochromes, purified recombinant HsCRY1 protein was stably isolated in the anionic radical flavin state, containing only a small proportion of oxidized flavin which could be reduced by illumination. We conclude that animal Type I and Type II cryptochromes may both have signaling mechanisms involving formation of a flavin radical signaling state, and that light independent activity of Type II cryptochromes is a consequence of dark accumulation of this redox form in vivo rather than of a fundamental difference in signaling mechanism. PMID:22427812

Vieira, Jacqueline; Jones, Alex R.; Danon, Antoine; Sakuma, Michiyo; Hoang, Nathalie; Robles, David; Tait, Shirley; Heyes, Derren J.; Picot, Marie; Yoshii, Taishi; Helfrich-Frster, Charlotte; Soubigou, Guillaume; Coppee, Jean-Yves; Klarsfeld, Andr; Rouyer, Francois; Scrutton, Nigel S.; Ahmad, Margaret

2012-01-01

343

The antimicrobial properties of light-activated polymers containing methylene blue and gold nanoparticles.  

PubMed

We report the formation of polysiloxane polymers containing embedded methylene blue and gold nanoparticles incorporated by a swell-encapsulation-shrink method. These polymers show significant antimicrobial activity against methicillin-resistant Staphylococcus aureus and Escherichia coli with up to a 3.5 log(10) reduction in the viable count when exposed for 5 min to light from a low power 660 nm laser. The bacterial kill is due to the light-induced production of singlet oxygen and other reactive oxygen species by the methylene blue. Interestingly, the presence of 2 nm gold nanoparticles significantly enhanced the ability of the methylene blue to kill bacteria. PMID:18838166

Perni, Stefano; Piccirillo, Clara; Pratten, Jonathan; Prokopovich, Polina; Chrzanowski, Wojciech; Parkin, Ivan P; Wilson, Michael

2009-01-01

344

Lightening up Light Therapy: Activation of Retrograde Signaling Pathway by Photobiomodulation.  

PubMed

Photobiomodulation utilizes monochromatic (or quasimonochromatic) light in the electromagnetic region of 600?1000 nm for the treatment of soft tissues in a nondestructive and nonthermal mode. It is conceivable that photobiomodulation is based upon the ability of the light to alter cell metabolism as it is absorbed by general hemoproteins and cytochrome c oxidase (COX) in particular. Recently it has been suggested radiation of visible and infrared (IR) activates retrograde signaling pathway from mitochondria to nucleus. In this review, the role of COX in the photobiomodulation will be discussed. Further a possible role of water as a photoreceptor will be suggested. PMID:25489415

Kim, Hong Pyo

2014-11-01

345

Lightening up Light Therapy: Activation of Retrograde Signaling Pathway by Photobiomodulation  

PubMed Central

Photobiomodulation utilizes monochromatic (or quasimonochromatic) light in the electromagnetic region of 600?1000 nm for the treatment of soft tissues in a nondestructive and nonthermal mode. It is conceivable that photobiomodulation is based upon the ability of the light to alter cell metabolism as it is absorbed by general hemoproteins and cytochrome c oxidase (COX) in particular. Recently it has been suggested radiation of visible and infrared (IR) activates retrograde signaling pathway from mitochondria to nucleus. In this review, the role of COX in the photobiomodulation will be discussed. Further a possible role of water as a photoreceptor will be suggested. PMID:25489415

Kim, Hong Pyo

2014-01-01

346

Advanced controls for floating wind turbines  

E-print Network

Floating Offshore Wind Turbines (FOWT) is a technology that stands to spearhead the rapid growth of the offshore wind energy sector and allow the exploration of vast high quality wind resources over coastal and offshore ...

Casanovas, Carlos (Casanovas Bermejo)

2014-01-01

347

Notes 11. High pressure floating ring seals  

E-print Network

Floating ring seals for compressors: leakage and force coefficients, seal lock up and effect on rotor stability, recommendations to reduce seal cross-coupled effects. Long oil seals as pressure barriers in industrial mixers: leakage and force...

San Andres, Luis

2009-01-01

348

Influence of softening test and light-activation protocols on resin composite polymer structure  

PubMed Central

Objective: This study analyzed the influences of the light-activation protocol and softening test on the degree of conversion (DC) and Knoop Hardness (KHN) of a microhybrid resin composite. Materials and Methods: Filtek Z250 (3M ESPE) was light-activated with a third-generation light-emitting diode (Valo Ultradent) by three protocols standard, high power, and plasma emulation or with a quartz-tungsten halogen XL 3000 (3M ESPE) in conventional mode. All modes were set to deliver 19 J/cm2. The DC (N = 20) was determined by Fourier transform infrared spectrometry on the top (T) and bottom (B) surfaces. For the KHN test, samples were subdivided in four groups (n = 5 each) according to the storage media: absolute ethanol, 75% ethanol, distilled water, and air (control group). The KHN values were evaluated on T and B before and 24 h after immersion in the storage media. Data were analyzed by split-plot analysis of variance (ANOVA; for DC) or repeated-measures split-plot ANOVA (for KHN), followed by Tukey's test (? = 0.05). Results: For the DC, the light-activation protocol did not influence the results and there was no difference between T and B. For the KHN test, the light-activation protocol did not influence the results and T showed higher microhardness values than B for all experimental conditions. There were significant differences in KHN depending on the storage media. Samples immersed in absolute ethanol generally presented lower KHN values, with no differences compared to samples in 75% ethanol. Conclusion: The storage media affected the outcomes of the softening test. PMID:24966740

Giorgi, Maria Ceclia Caldas; Lima, Dbora Alves Nunes Leite; Marchi, Giselle Maria; Ambrosano, Glucia Maria; Aguiar, Flvio Henrique Baggio

2014-01-01

349

Activation of retinal tyrosine hydroxylase: tolerance induced by chronic treatment with haloperidol does not modify response to light  

SciTech Connect

A single dose of haloperidol administered to rats in the dark increases the activity of retinal tyrosine hydroxylase. The ability of haloperidol to activate the enzyme is diminished 24 hr after terminating 22 to 30 days of treatment with haloperidol. The retinal enzyme is also tolerant to activation by treatment with chlorpromazine. In contrast, exposure of the animals to light activates the enzyme to the same extent in chronic haloperidol-treated and control animals. Thus, chronic haloperidol treatment does not modify the ability of the retinal enzyme system to respond to the physiological stimulus, light. Apparently, activation of retinol tyrosine hydroxylase by haloperidol and light occurs by independent mechanisms.

Cohen, J.; Neff, N.H.

1982-05-01

350

[Bilateral floating forearm: a case report].  

PubMed

The combination of elbow dislocation and perilunate dislocation is rare. The prognosis of this condition depends mainly on that of the wrist. While some cases of floating forearm have been reported, no bilateral affection has -of yet- to our knowledge, been published. The authors report a case of a young patient who presented with bilateral floating forearm after a fall from a height. The treatment was surgical at the wrist. The functional result is similar to cases reported in the literature. PMID:21507701

Zejjari, H; Louaste, J; Chkoura, M; Rachid, K

2011-04-01

351

Decimal Floating-Point: Algorism for Computers  

Microsoft Academic Search

Decimal arithmetic is the norm in human calculations, and human-centric applications must use a decimal floating-point arithmetic to achieve the same results. Initial benchmarks indicate that some applications spend 50% to 90% of their time in decimal processing, because software decimal arithmetic suffers a 100 to 1000 performance penalty over hardware. The need for decimal floating-point in hardware is urgent.

Michael F. Cowlishaw; Coventry CV

2003-01-01

352

Light is an active contributor to the vital effects of coral skeleton proxies  

NASA Astrophysics Data System (ADS)

Symbiotic colonies of the coral Acropora sp. were cultured in a factorial design of three temperatures (21, 25 and 28 C) and two light intensities (200 and 400 ?mol photon m-2 s-1), under constant conditions. A temperature of 25 C and a light intensity of 200 ?mol photon m-2 s-1 was the starting culture condition. Metabolic (photosynthesis, respiration, calcification and surface expansion rate) and geochemical measurements (?18O, ?13C, Sr/Ca and Mg/Ca) were conducted on 6 colonies for each experimental condition. Metabolic measurements confirmed that respiration, photosynthesis, calcification and surface expansion rate responded to the combined effect of temperature and light. Under each light intensity, mean calcification rate was linearly correlated with mean photosynthetic activity. Geochemical measurements were also influenced by temperature and, to a lesser degree, by light. All geochemical proxies measured on 6 nubbins showed a wide scattering of values, regardless of the environmental condition. Compared to the other proxies, ?18O exhibited a different behavior. It was the only proxy exhibiting temperature tracer behavior. However, while mean values of Sr/Ca, Mg/Ca and ?13C were well correlated, the correlation between the later and mean ?18O differed with light level. This suggests that both skeleton deposition and temperature oxygen fractionation differs according to light intensity. Overall, the effect of light on geochemical values seems to compromise the use of proxy calibrations solely based on temperature influence. Under high light conditions, the great amplitude shown by individual net photosynthesis is directly proportional to the highly variable zooxanthellae density. As light is affecting all of the proxies, we thus assume that the strong geochemical variability observed could be explained by various algae densities, each nubbin responding according to its zooxanthellae amount. Accordingly, we suggest that each symbiosome (the assemblage of few corallites with their symbionts) presents its own vital effect influence over time. Therefore, at a bulk sample scale, light could be considered as one of the major causes of what is commonly referred to as the vital effect. The meaning of ?18O calibration versus temperature established from distinct colonies differs from calibration calculated from samples collected following the growth axis of a single coral head. Finally, in order to quantitatively reconstruct climatic condition, we suggest a new paradigm based on the statistical treatment of the combination of time-series information from several proxies, all measured on the same sample from a continuous symbiosome.

Juillet-Leclerc, Anne; Reynaud, Stphanie; Dissard, Delphine; Tisserand, Guillaume; Ferrier-Pags, Christine

2014-09-01

353

Floating assembly of diatom Coscinodiscus sp. microshells.  

PubMed

Diatoms have silica frustules with transparent and delicate micro/nano scale structures, two dimensional pore arrays, and large surface areas. Although, the diatom cells of Coscinodiscus sp. live underwater, we found that their valves can float on water and assemble together. Experiments show that the convex shape and the 40 nm sieve pores of the valves allow them to float on water, and that the buoyancy and the micro-range attractive forces cause the valves to assemble together at the highest point of water. As measured by AFM calibrated glass needles fixed in manipulator, the buoyancy force on a single floating valve may reach up to 10 ?N in water. Turning the valves over, enlarging the sieve pores, reducing the surface tension of water, or vacuum pumping may cause the floating valves to sink. After the water has evaporated, the floating valves remained in their assembled state and formed a monolayer film. The bonded diatom monolayer may be valuable in studies on diatom based optical devices, biosensors, solar cells, and batteries, to better use the optical and adsorption properties of frustules. The floating assembly phenomenon can also be used as a self-assembly method for fabricating monolayer of circular plates. PMID:22387476

Wang, Yu; Pan, Junfeng; Cai, Jun; Zhang, Deyuan

2012-03-30

354

Impact of floating population on the epidemic of tuberculosis: a spatial analysis  

NASA Astrophysics Data System (ADS)

According to the report issued by the Health Bureau of Beijing that the number of newly registered active pulmonary tuberculosis cases in floating population exceeded half of that in registered permanent residence in 2006. More attention has been paid to the tuberculosis of floating population. Materials and methods: The population data included in the studied was reported by the Beijing Police Bureau in 2004, and the case source from 2004 to 2006 was provided by Beijing Research Institute for TB Control. Two GIS-based methods have been used to detect the hot spots of tuberculosis in 18 districts of Beijing. Results: The distributions of hot spots of tuberculosis in Beijing are significantly associated with that of floating people. Most likely cluster from all population matches with those from floating population, which is stable from 2004 to 2006. Conclusion: The spatial analytical results indicated that the floating population has a drastic influence on the epidemic of tuberculosis in Beijing. The tuberculosis control measures should incorporate the effect of floating population.

Jia, Zhongwei; He, Xiaoxin; Zhao, Wenjuan; An, Yansheng; Cao, Wuchun; Li, Xiaowen

2007-06-01

355

Floating Ice-Algal Aggregates below Melting Arctic Sea Ice  

PubMed Central

During two consecutive cruises to the Eastern Central Arctic in late summer 2012, we observed floating algal aggregates in the melt-water layer below and between melting ice floes of first-year pack ice. The macroscopic (1-15 cm in diameter) aggregates had a mucous consistency and were dominated by typical ice-associated pennate diatoms embedded within the mucous matrix. Aggregates maintained buoyancy and accumulated just above a strong pycnocline that separated meltwater and seawater layers. We were able, for the first time, to obtain quantitative abundance and biomass estimates of these aggregates. Although their biomass and production on a square metre basis was small compared to ice-algal blooms, the floating ice-algal aggregates supported high levels of biological activity on the scale of the individual aggregate. In addition they constituted a food source for the ice-associated fauna as revealed by pigments indicative of zooplankton grazing, high abundance of naked ciliates, and ice amphipods associated with them. During the Arctic melt season, these floating aggregates likely play an important ecological role in an otherwise impoverished near-surface sea ice environment. Our findings provide important observations and measurements of a unique aggregate-based habitat during the 2012 record sea ice minimum year. PMID:24204642

Assmy, Philipp; Ehn, Jens K.; Fernndez-Mndez, Mar; Hop, Haakon; Katlein, Christian; Sundfjord, Arild; Bluhm, Katrin; Daase, Malin; Engel, Anja; Fransson, Agneta; Granskog, Mats A.; Hudson, Stephen R.; Kristiansen, Svein; Nicolaus, Marcel; Peeken, Ilka; Renner, Angelika H. H.; Spreen, Gunnar; Tatarek, Agnieszka; Wiktor, Jozef

2013-01-01

356

Floating ice-algal aggregates below melting arctic sea ice.  

PubMed

During two consecutive cruises to the Eastern Central Arctic in late summer 2012, we observed floating algal aggregates in the melt-water layer below and between melting ice floes of first-year pack ice. The macroscopic (1-15 cm in diameter) aggregates had a mucous consistency and were dominated by typical ice-associated pennate diatoms embedded within the mucous matrix. Aggregates maintained buoyancy and accumulated just above a strong pycnocline that separated meltwater and seawater layers. We were able, for the first time, to obtain quantitative abundance and biomass estimates of these aggregates. Although their biomass and production on a square metre basis was small compared to ice-algal blooms, the floating ice-algal aggregates supported high levels of biological activity on the scale of the individual aggregate. In addition they constituted a food source for the ice-associated fauna as revealed by pigments indicative of zooplankton grazing, high abundance of naked ciliates, and ice amphipods associated with them. During the Arctic melt season, these floating aggregates likely play an important ecological role in an otherwise impoverished near-surface sea ice environment. Our findings provide important observations and measurements of a unique aggregate-based habitat during the 2012 record sea ice minimum year. PMID:24204642

Assmy, Philipp; Ehn, Jens K; Fernndez-Mndez, Mar; Hop, Haakon; Katlein, Christian; Sundfjord, Arild; Bluhm, Katrin; Daase, Malin; Engel, Anja; Fransson, Agneta; Granskog, Mats A; Hudson, Stephen R; Kristiansen, Svein; Nicolaus, Marcel; Peeken, Ilka; Renner, Angelika H H; Spreen, Gunnar; Tatarek, Agnieszka; Wiktor, Jozef

2013-01-01

357

Effects of light exposure on the retention of kleptoplastic photosynthetic activity in the sacoglossan mollusc Elysia viridis  

Microsoft Academic Search

The effects of light exposure on the photosynthetic activity of kleptoplasts were studied in the sacoglossan mollusc Elysia viridis. The photosynthetic activity of ingested chloroplasts was assessed in vivo by non-destructively measuring photophysiological\\u000a parameters using pulse amplitude modulation (PAM) fluorometry. Animals kept under starvation were exposed to two contrasting\\u000a light conditions, 30?mol photons m?2s?1 (low light, LL), and 140?mol photons

S. Vieira; R. Calado; H. Coelho; Joo Serdio

2009-01-01

358

AgVO3 nanorods: Synthesis, characterization and visible light photocatalytic activity  

NASA Astrophysics Data System (ADS)

Large scale and high purity silver vanadate (AgVO3) nanorods were synthesized by thermal decomposition method. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, Ultraviolet-Visible (DRS-UV-Visible) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to characterize the structure, light absorption capacity and morphology of the as-synthesized sample. The photocatalytic activity of AgVO3 nanorods was examined by degradation of methylene blue (MB) as a model organic pollutant. The degradation efficiency is 85.02% in the 120min visible light illumination. Further, the AgVO3 nanorods were used as a photocatalyst for industrial effluent. 95.4% degradation efficiency was obtained within the visible light irradiation of 120min. The possible photocatalytic mechanism has also been proposed.

Sivakumar, V.; Suresh, R.; Giribabu, K.; Narayanan, V.

2015-01-01

359

Mass spectrometry footprinting reveals the structural rearrangements of cyanobacterial orange carotenoid protein upon light activation.  

PubMed

The orange carotenoid protein (OCP), a member of the family of blue light photoactive proteins, is required for efficient photoprotection in many cyanobacteria. Photoexcitation of the carotenoid in the OCP results in structural changes within the chromophore and the protein to give an active red form of OCP that is required for phycobilisome binding and consequent fluorescence quenching. We characterized the light-dependent structural changes by mass spectrometry-based carboxyl footprinting and found that an ? helix in the N-terminal extension of OCP plays a key role in this photoactivation process. Although this helix is located on and associates with the outside of the ?-sheet core in the C-terminal domain of OCP in the dark, photoinduced changes in the domain structure disrupt this interaction. We propose that this mechanism couples light-dependent carotenoid conformational changes to global protein conformational dynamics in favor of functional phycobilisome binding, and is an essential part of the OCP photocycle. PMID:25256653

Liu, Haijun; Zhang, Hao; King, jeremy D; Wolf, Nathan R; Prado, Mindy; Gross, Michael L; Blankenship, Robert E

2014-12-01

360

Engineering Escherichia coli for light-activated cytolysis of mammalian cells.  

PubMed

By delivering payloads in response to specific exogenous stimuli, smart bacterial therapeutics have the potential to overcome many limitations of conventional therapies, including poor targeting specificity and dosage control in current cancer treatments. Although not yet explored as a trigger for bacterial drug delivery, light is an ideal induction mechanism because it offers fine spatiotemporal control and is easily and safely administered. Using recent advances in optogenetics, we have engineered two strains of Escherichia coli to secrete a potent mammalian cytotoxin in response to blue or red light. The tools in this study demonstrate the initial feasibility of light-activated bacterial therapeutics for applications such as tumor cytolysis, and their modular nature should enable simple substitution of other payloads of interest. PMID:24933444

Magaraci, Michael S; Veerakumar, Avin; Qiao, Peter; Amurthur, Ashwin; Lee, Justin Y; Miller, Jordan S; Goulian, Mark; Sarkar, Casim A

2014-12-19

361

Biomechanical model produced from light-activated dental composite resins: a holographic analysis  

NASA Astrophysics Data System (ADS)

Light-activated dental composites, commonly applied in dentistry, can be used as excellent material for producing biomechanical models. They can be cast in almost any shape in an appropriate silicone mold and quickly solidified by irradiation with light in the blue part of the spectrum. In that way, it is possible to obtain any number of nearly identical casts. The models can be used to study the behavior of arbitrary structure under mechanical loads. To test the technique, a simple mechanical model of the tooth with a mesio-occluso-distal cavity was manufactured. Composite resin restoration was placed inside the cavity and light cured. Real-time holographic interferometry was used to analyze the contraction of the composite resin and its effect on the surrounding material. The results obtained in the holographic experiment were in good agreement with those obtained using the finite element method.

Panteli?, Dejan; Vasiljevi?, Darko; Blai?, Larisa; Savi?-evi?, Svetlana; Muri?, Branka; Nikoli?, Marko

2013-11-01

362

DISTINCT PATTERNS OF NITRATE REDUCTASE ACTIVITY IN BROWN ALGAE: LIGHT AND AMMONIUM SENSITIVITY IN LAMINARIA DIGITATA IS ABSENT IN  

E-print Network

DISTINCT PATTERNS OF NITRATE REDUCTASE ACTIVITY IN BROWN ALGAE: LIGHT AND AMMONIUM SENSITIVITY and lowest in summer. This is the first report of NR activity in any alga that is not strongly regulated the regulation of NR by light that has been observed in other algae and higher plants. Key index words: ammonium

Berges, John A.

363

Cadmium uptake by floating macrophytes.  

PubMed

Cd uptake capacity of a group of floating macrophytes (Salvinia herzogii, Pistia stratiotes, Hydromistia stolonifera and Eichhornia crassipes) was determined in outdoors experiments during the lowest temperature period of the year. Although all studied species were highly efficient in the Cd uptake, Pistia stratiotes was selected for further research because of its superior performance and its higher average relative growth rate. Cadmium% removal by Pistia stratiotes was greater in the first 24 h of the experiments (63, 65, 72 and 74% of the added Cd for 1, 2, 4 and 6 mg Cd 1(-1), respectively). After 31 days of growth, Pistia statiotes efficiently removed Cd at the studied concentrations. The macrophyte was able to keep its capacity for Cd removal even though some toxicity symptoms appeared at 4 and 6 mg Cd 1(-1). The greater the initial concentration, the greater Cd bioaccumulation rates. The increase of Cd concentration in plant tissues occurred especially in roots and was linearly related to the quantity of Cd added. Cd sorption by roots is faster than translocation to the plant aerial part and it occurs mainly during the first 24h. PMID:11456161

Maine, M A; Duarte, M V; Su, N L

2001-08-01

364

A spinal opsin controls early neural activity and drives a behavioral light response.  

PubMed

Nonvisual detection of light by the vertebrate hypothalamus, pineal, and retina is known to govern seasonal and circadian behaviors. However, the expression of opsins in multiple other brain structures suggests a more expansive repertoire for light regulation of physiology, behavior, and development. Translucent zebrafish embryos express extraretinal opsins early on, at a time when spontaneous activity in the developing CNS plays a role in neuronal maturation and circuit formation. Though the presence of extraretinal opsins is well documented, the function of direct photoreception by the CNS remains largely unknown. Here, we show that early activity in the zebrafish spinal central pattern generator (CPG) and the earliest locomotory behavior are dramatically inhibited by physiological levels of environmental light. We find that the photosensitivity of this circuit is conferred by vertebrate ancient long opsin A (VALopA), which we show to be a G?(i)-coupled receptor that is expressed in the neurons of the spinal network. Sustained photoactivation of VALopA not only suppresses spontaneous activity but also alters the maturation of time-locked correlated network patterns. These results uncover a novel role for nonvisual opsins and a mechanism for environmental regulation of spontaneous motor behavior and neural activity in a circuit previously thought to be governed only by intrinsic developmental programs. PMID:25484291

Friedmann, Drew; Hoagland, Adam; Berlin, Shai; Isacoff, Ehud Y

2015-01-01

365

Synchronous Activation of Cell Division by Light or Temperature Stimuli in the Dimorphic Yeast Schizosaccharomyces japonicus  

PubMed Central

Many fungi respond to light and regulate fungal development and behavior. A blue light-activated complex has been identified in Neurospora crassa as the product of the wc-1 and wc-2 genes. Orthologs of WC-1 and WC-2 have hitherto been found only in filamentous fungi and not in yeast, with the exception of the basidiomycete pathogenic yeast Cryptococcus. Here, we report that the fission yeast Schizosaccharomyces japonicus responds to blue light depending on Wcs1 and Wcs2, orthologs of components of the WC complex. Surprisingly, those of ascomycete S. japonicus are more closely related to those of the basidiomycete. S. japonicus reversibly changes from yeast to hyphae in response to environmental stresses. After incubation at 30C, a colony of yeast was formed, and then hyphal cells extended from the periphery of the colony. When light cycles were applied, distinct dark- and bright-colored hyphal cell stripes were formed because the growing hyphal cells had synchronously activated cytokinesis. In addition, temperature cycles of 30C for 12 h and 35C for 12 h or of 25C for 12 h and 30C for 12 h during incubation in the dark induced a response in the hyphal cells similar to that of light. The stripe formation of the temperature cycles was independent of the wcs genes. Both light and temperature, which are daily external cues, have the same effect on growing hyphal cells. A dual sensing mechanism of external cues allows organisms to adapt to daily changes of environmental alteration. PMID:23873862

Okamoto, Sho; Furuya, Kanji; Nozaki, Shingo; Aoki, Keita

2013-01-01

366

Active-region Tilt Angles: Magnetic versus White-light Determinations of Joy's Law  

NASA Astrophysics Data System (ADS)

The axes of solar active regions are inclined relative to the east-west direction, with the tilt angle tending to increase with latitude ("Joy's law"). Observational determinations of Joy's law have been based either on white-light images of sunspot groups or on magnetograms, where the latter have the advantage of measuring directly the physically relevant quantity (the photospheric field), but the disadvantage of having been recorded routinely only since the mid-1960s. White-light studies employing the historical Mount Wilson (MW) database have yielded tilt angles that are smaller and that increase less steeply with latitude than those obtained from magnetic data. We confirm this effect by comparing sunspot-group tilt angles from the Debrecen Photoheliographic Database with measurements made by Li and Ulrich using MW magnetograms taken during cycles 21-23. Whether white-light or magnetic data are employed, the median tilt angles significantly exceed the mean values, and provide a better characterization of the observed distributions. The discrepancy between the white-light and magnetic results is found to have two main sources. First, a substantial fraction of the white-light "tilt angles" refer to sunspots of the same polarity. Of greater physical significance is that the magnetograph measurements include the contribution of plage areas, which are invisible in white-light images but tend to have greater axial inclinations than the adjacent sunspots. Given the large uncertainties inherent in both the white-light and the magnetic measurements, it remains unclear whether any systematic relationship exists between tilt angle and cycle amplitude during cycles 16-23.

Wang, Y.-M.; Colaninno, R. C.; Baranyi, T.; Li, J.

2015-01-01

367

Blue-light-activated phototropin2 trafficking from the cytoplasm to Golgi/post-Golgi vesicles  

PubMed Central

Phototropins are plasma membrane-localized UVA/blue light photoreceptors which mediate phototropism, inhibition of primary hypocotyl elongation, leaf positioning, chloroplast movements, and stomatal opening. Blue light irradiation activates the C-terminal serine/threonine kinase domain of phototropin which autophosphorylates the receptor. Arabidopsis thaliana encodes two phototropins, phot1 and phot2. In response to blue light, phot1 moves from the plasma membrane into the cytosol and phot2 translocates to the Golgi complex. In this study the molecular mechanism and route of blue-light-induced phot2 trafficking are demonstrated. It is shown that Atphot2 behaves in a similar manner when expressed transiently under 35S or its native promoter. The phot2 kinase domain but not blue-light-mediated autophosphorylation is required for the receptor translocation. Using co-localization and western blotting, the receptor was shown to move from the cytoplasm to the Golgi complex, and then to the post-Golgi structures. The results were confirmed by brefeldin A (an inhibitor of the secretory pathway) which disrupted phot2 trafficking. An association was observed between phot2 and the light chain2 of clathrin via bimolecular fluorescence complementation. The fluorescence was observed at the plasma membrane. The results were confirmed using co-immunoprecipitation. However, tyrphostin23 (an inhibitor of clathrin-mediated endocytosis) and wortmannin (a suppressor of receptor endocytosis) were not able to block phot2 trafficking, indicating no involvement of receptor endocytosis in the formation of phot2 punctuate structures. Protein turnover studies indicated that the receptor was continuously degraded in both darkness and blue light. The degradation of phot2 proceeded via a transport route different from translocation to the Golgi complex. PMID:24821953

Aggarwal, Chhavi; Bana?, Agnieszka Katarzyna; Kasprowicz-Malu?ki, Anna; Borghetti, Carolina; ?abuz, Justyna; Dobrucki, Jerzy; Gabry?, Halina

2014-01-01

368

Development of White-Light Emitting Active Layers in Nitride Based Heterostructures for Phosphorless Solid State Lighting  

SciTech Connect

This report provides a summary of research activities carried out at the University of California, San Diego and Central Research of OSRAM SYLVANIA in Beverly, MA partially supported by a research contract from US Department of Energy, DE-FC26-04NT422274. The main objective of this project was to develop III-V nitrides activated by rare earth ions, RE{sup 3+}, which could eliminate the need for phosphors in nitride-based solid state light sources. The main idea was to convert electron-hole pairs injected into the active layer in a LED die to white light directly through transitions within the energy levels of the 4f{sup n}-manifold of RE{sup 3+}. We focused on the following materials: Eu{sup 3+}(red), Tb{sup 3+}(green), Er{sup 3+}(green), Dy{sup 3+}(yellow) and Tm{sup 3+}(blue) in AlN, GaN and alloys of AlN and GaN. Our strategy was to explore candidate materials in powder form first, and then study their behavior in thin films. Thin films of these materials were to be deposited on sapphire substrates using pulsed laser deposition (PLD) and metal organic vapor phase epitaxy (MOVPE). The photo- and cathode-luminescence measurements of these materials were used to investigate their suitability for white light generation. The project proceeded along this route with minor modifications needed to produce better materials and to expedite our progress towards the final goal. The project made the following accomplishments: (1) red emission from Eu{sup 3+}, green from Tb{sup 3+}, yellow from Dy{sup 3+} and blue from Tm{sup 3+} in AlN powders; (2) red emission from Eu{sup 3+} and green emission from Tb{sup 3+} in GaN powder; (3) red emission from Eu{sup 3+} in alloys of GaN and AlN; (4) green emission from Tb{sup 3+} in GaN thin films by PLD; (5) red emission from Eu{sup 3+} and Tb{sup 3+} in GaN thin films deposited by MOVPE; (6) energy transfer from host to RE{sup 3+}; (7) energy transfer from Tb{sup 3+} to Eu{sup 3+} in AlN powders; (8) emission from AlN powder samples codoped with (Eu{sup 3+} ,Tb{sup 3+} ) and (Dy{sup 3+}, Tm{sup 3+}); and (9) white emission from AlN codoped with Dy{sup 3+} and Tm{sup 3+}. We also extensively studied the stabilities of rare earth ions in GaN, and the nature of oxygen defects in GaN and its impact on the optical properties of the host material, using first principles method. Results from these theoretical calculations together with fluorescence measurements from the materials essentially proved the underlying concepts for generating white light using RE{sup 3+}-activated nitrides. For this project, we successfully built a horizontal MOVPE reactor and used it to deposit thin films of undoped and doped nitrides of GaN and InGaN, which is a very significant achievement. Since this reactor was designed and built by in-house experts, it could be easily modified and reassembled for specific research purposes. During this study, it was successfully modified for homogeneous distribution of rare earth ions in a deposited film. It will be an ideal tool for future research involving novel thin film material concepts. We examined carefully the suitability of various metal organic precursors for incorporating RE{sup 3+}. In order to avoid oxygen contamination, several oxygen-free RE{sup 3+} precursors were identified. Both oxygen-free and oxygen- containing metal organic precursors were used for certain rare earth ions (Eu{sup 3+}, Tb{sup 3+} and Er{sup 3+}). However, the suitability of any particular type of precursor for MOVPE deposition was not established during this study, and further study is needed. More intensive research in the future is needed to improve the film quality, and eliminate the separation of rare earth oxide phases during the deposition of thin films by MOVPE. The literature in the area of the chemistry of rare earth ions in nitrides is almost nonexistent, in spite of the significant research on luminescence of RE{sup 3+} in nitrides. Consequently, MOVPE as a method of deposition of RE{sup 3+}-activated nitrides is relatively unexplored. In the following sections of this report, the ou

Jan Talbot; Kailash Mishra

2007-12-31

369

Photo-induced bending in a light-activated polymer laminated composite.  

PubMed

Light activated polymers (LAPs) have attracted increasing attention since these materials change their shape and/or behavior in response to light exposure, which serves as an instant, remote and precisely controllable stimulus that enables non-contact control of the material shape and behavior through simple variation in light intensity, wavelength and spatially controlled exposure. These features distinguish LAPs from other active polymers triggered by other stimuli such as heat, electrical field or humidity. Previous examples have resulted in demonstrations in applications such as surface patterning, photo-induced shape memory behavior, and photo-origami. However, in many of these applications, an undesirable limitation has been the requirement to apply and maintain an external load during light irradiation. In this paper, a laminated structure is introduced to provide a pre-programmed stress field, which is then used for photo-induced deformation. This laminated structure is fabricated by bonding a stretched elastomer (NOA65) sheet between two LAP layers. Releasing the elastomer causes contraction and introduces a compressive stress in the LAPs, which are relaxed optically to trigger the desired deformation. A theoretical model is developed to quantitatively examine the laminated composite system, allowing exploration of the design space and optimum design of the laminate. PMID:25690905

Mu, Xiaoming; Sowan, Nancy; Tumbic, Julia A; Bowman, Christopher N; Mather, Patrick T; Qi, H Jerry

2015-03-18

370

Visible-Light-Induced Bactericidal Activity of Titanium Dioxide Co-doped with Nitrogen and Silver  

PubMed Central

Titanium dioxide nanoparticles co-doped with nitrogen and silver (Ag2O/TiON) were synthesized by the sol-gel process and found to be an effective visible light driven photocatalyst. The catalyst showed strong bactericidal activity against Escherichia coli (E. coli) under visible light irradiation (?> 400 nm). In x-ray photoelectron spectroscopy and x-ray diffraction characterization of the samples, the as-added Ag species mainly exist as Ag2O. Spin trapping EPR study showed Ag addition greatly enhanced the production of hydroxyl radicals (OH) under visible light irradiation. The results indicate that the Ag2O species trapped eCB? in the process of Ag2O/TiON photocatalytic reaction, thus inhibiting the recombination of eCB? and hVB+ in agreement with the stronger photocatalytic bactericidal activity of Ag2O/TiON. The killing mechanism of Ag2O/TiON under visible light irradiation is shown to be related to oxidative damages in the forms of cell wall thinning and cell disconfiguration. PMID:20726520

Wu, Pinggui; Xie, Rongcai; Imlay, Kari; Shang, Jian-Ku

2011-01-01

371

Nonvital tooth bleaching with halogen light-activated agents: case reports and discussion.  

PubMed

Esthetic dentistry has received increased attention in recent years, as people are more aware of the esthetic appearance of their teeth, including alignment and whiteness. This development, combined with a decrease in the incidence and severity of caries, has directed some clinicians toward conservative and non-invasive treatments such as tooth bleaching. A number of methods for nonvital tooth bleaching are described in the literature; these procedures rely on the bleaching agent used, the agent's concentration, product format, and the source of light activation. This article presents two case reports in which dental bleaching with halogen light-activated agents was used to treat a nonvital discolored incisor. The advantages and disadvantages of the technique are discussed. PMID:19903622

Meireles, Sonia Saeger; Demarco, Flavio Fernando; Tarquinio, Sandra Beatriz Chaves

2009-01-01

372

Defect self-doped TiO? for visible light activity and direct noble metal anchoring.  

PubMed

A facile approach was developed for preparing defective, self-doped TiO2, which shows remarkable visible light activity in the photocatalytic degradation of RhB and hydrogen liberation from water. Moreover, noble metal was directly deposited onto the TiO2 surface via an in situ redox reaction between surficial Ti(3+) and metal salt. The lack of involvement of foreign reducing agents or stabilizers permits intimate contact between metal nanoparticles and the TiO2 substrate, which ensures the facilitated interfacial charge transfer. The strategy presented in this work may be applied to design other defect and noble metal mediated visible-light-active photocatalysts. PMID:25203901

Pei, Zengxia; Ding, Luyao; Feng, Wenhui; Weng, Sunxian; Liu, Ping

2014-10-21

373

Induction of beta-glucosidase activity in maize coleoptiles by blue light illumination.  

PubMed

The role of beta-glucosidase during the phototropic response in maize (Zea mays) coleoptiles was investigated. Unilateral blue light illumination abruptly up-regulated the activity of beta-glucosidase in the illuminated halves, 10 min after the onset of illumination, peaking after 30 min and decreasing thereafter. The level of 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), which is released from DIMBOA glucoside (DIMBOA-Glc) by beta-glucosidase, and its degradation compound 6-methoxy-benzoxazolinone (MBOA) were elevated within 30 min in the illuminated halves as compare to the shaded halves, prior to the phototropic curvature. Furthermore, beta-glucosidase inhibitor treatment significantly decreased the phototropic curvature and decreased growth suppression in the illuminated sides. These results suggest that blue light induces the activity of beta-glucosidase in the illuminated halves of coleoptiles causing an increase in DIMBOA biosynthesis and the growth inhibition that leads to a phototropic curvature. PMID:16473658

Jabeen, Riffat; Yamada, Kosumi; Shigemori, Hideyuki; Hasegawa, Tsuyoshi; Hara, Masakazu; Kuboi, Toru; Hasegawa, Koji

2006-03-01

374

Preparation and characterization of porous C-modified anatase titania films with visible light catalytic activity  

SciTech Connect

Visible-light-activated C-modified anatase titania films have been synthesized from TiCl{sub 4} and carbonic ink by using the sol-gel route. The synthesized photocatalysts were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and optical measurements. The modifying carbon not only produces homogeneous worm-like structure with uniform pores, but also extends the absorbance spectra of the as-prepared films into visible region. The results of visible-light-induced degradation of methyl orange (MO) show that the C-modified titania films exhibits much higher photocatalytic activities than that of pure titania film prepared at the same conditions. - Graphical abstract: Carbon modifying not only produces homogeneous worm-like structure with uniform pores, but also extends the absorbance spectra of the as-prepared titania films into visible region.

Xie Yi [Key Laboratory of Silicate Materials Science and Engineering, Wuhan University of Technology, Ministry of Education, Wuhan, Hubei 430070 (China); Zhao Xiujian [Key Laboratory of Silicate Materials Science and Engineering, Wuhan University of Technology, Ministry of Education, Wuhan, Hubei 430070 (China)], E-mail: opluse@whut.edu.cn; Chen Yunxia; Zhao Qingnan; Yuan Qihua [Key Laboratory of Silicate Materials Science and Engineering, Wuhan University of Technology, Ministry of Education, Wuhan, Hubei 430070 (China)

2007-12-15

375

Safety target of very large floating structure used as a floating airport  

Microsoft Academic Search

Technological Research Association of Mega-float is developing pontoon-type very large floating structures (VLFS). This system consists of floater, moorings and breakwater. If the VLFS is used as an airport, many passenger, crews and ground service persons will stay on the VLFS. VLFS also supports many facilities and properties. VLFS must be highly safe and this paper presents a discussion on

Hideyuki Suzuki

2001-01-01

376

The antimicrobial properties of light-activated polymers containing methylene blue and gold nanoparticles  

Microsoft Academic Search

We report the formation of polysiloxane polymers containing embedded methylene blue and gold nanoparticles incorporated by a swell-encapsulation-shrink method. These polymers show significant antimicrobial activity against methicillin-resistant Staphylococcus aureus and Escherichia coli with up to a 3.5 log10 reduction in the viable count when exposed for 5min to light from a low power 660nm laser. The bacterial kill is due

Stefano Perni; Clara Piccirillo; Jonathan Pratten; Polina Prokopovich; Wojciech Chrzanowski; Ivan P. Parkin; Michael Wilson

2009-01-01

377

Earthquake lights and the stress-activation of positive hole charge carriers in rocks  

Microsoft Academic Search

Earthquake-related luminous phenomena (also known as earthquake lights) may arise from (1) the stress-activation of positive hole (p-hole) charge carriers in igneous rocks and (2) the accumulation of high charge carrier concentrations at asperities in the crust where the stress rates increase very rapidly as an earthquake approaches. It is proposed that, when a critical charge carrier concentration is reached,

France St-Laurent; John S. Derr; Friedemann T. Freund

2006-01-01

378

Light Activation of the Insulin Receptor Regulates Mitochondrial Hexokinase. A Possible Mechanism of Retinal Neuroprotection  

PubMed Central

The serine/threonine kinase Akt has been shown to mediate the anti-apoptotic activity through hexokinase (HK)-mitochondria interaction. We previously reported that Akt activation in retinal rod photoreceptor cells is mediated through light-dependent insulin receptor (IR)/PI3K pathway. Our data indicate that light-induced activation of IR/PI3K/Akt results in the translocation of HK-II to mitochondria. We also found that PHLPPL, a serine/threonine phosphatase, enhanced the binding of HK-II to mitochondria. We found a mitochondrial targeting signal in PHLPPL and our study suggests that Akt translocation to mitochondria could be mediated through PHLPPL. Our results suggest that light-dependent IR/PI3K/Akt pathway regulates hexokinase-mitochondria interaction in photoreceptors. Down-regulation of IR signaling has been associated with ocular diseases of retinitis pigmentosa, diabetic retinopathy, and Leber Congenital Amaurosis-type 2, and agents that enhance the binding interaction between hexokinase and mitochondria may have therapeutic potential against these ocular diseases. PMID:23993956

Rajala, Ammaji; Gupta, Vivek K.; Anderson, Robert E.; Rajala, Raju V.S.

2013-01-01

379

Improved expression of halorhodopsin for light-induced silencing of neuronal activity  

PubMed Central

The ability to control and manipulate neuronal activity within an intact mammalian brain is of key importance for mapping functional connectivity and for dissecting the neural circuitry underlying behaviors. We have previously generated transgenic mice that express channelrhodopsin-2 for light-induced activation of neurons and mapping of neural circuits. Here we describe transgenic mice that express halorhodopsin (NpHR), a light-driven chloride pump, that can be used to silence neuronal activity via light. Using the Thy-1 promoter to target NpHR expression to neurons, we found that neurons in these mice expressed high levels of NpHR-YFP and that illumination of cortical pyramidal neurons expressing NpHR-YFP led to rapid, reversible photoinhibition of action potential firing in these cells. However, NpHR-YFP expression led to the formation of numerous intracellular blebs, which may disrupt neuronal function. Labeling of various subcellular markers indicated that the blebs arise from retention of NpHR-YFP in the endoplasmic reticulum. By improving the signal peptide sequence and adding an ER export signal to NpHR-YFP, we eliminated the formation of blebs and dramatically increased the membrane expression of NpHR-YFP. Thus, the improved version of NpHR should serve as an excellent tool for neuronal silencing in vitro and in vivo. PMID:18931914

Zhao, Shengli; Cunha, Catarina; Zhang, Feng; Liu, Qun; Gloss, Bernd; Deisseroth, Karl; Augustine, George J.; Feng, Guoping

2011-01-01

380

Active display and encoding by integrated plasmonic polarizer on light-emitting-diode  

PubMed Central

An electrical pumped microscopic active display with integration of plasmonic polarizer and light-emitting-diode is proposed. Thanks to the strong polarized emission through the rectangular nanoholes, well designed pixels with respect to different polarizations are engineered, which give rise to flexible and controllable active display. As results, polarization multiplexed letter encoding, single and double gray-scale images and animation movies are successfully realized. Our results demonstrate a new strategy in electro-optical integration and indicate potential applications in designing new type of microscopic electro-optical devices. PMID:24008314

Wang, L.; Li, T.; Guo, R. Y.; Xia, W.; Xu, X. G.; Zhu, S. N.

2013-01-01

381

Sonoluminescence: Sound into Light  

Microsoft Academic Search

Bubbles floating in a glass of water do more than catch the light, sometimes they can produce it. A focused roar of sound energy can cause air bubbles to emit flashes lasting trillionths of a second. The cool blueness of this radiance is misleading: imploding shock waves rebounding through a bubble's interior can raise its temperature far above that of

Seth J. Putterman

1995-01-01

382

The effect of power bleaching actived by several light sources on enamel microhardness  

NASA Astrophysics Data System (ADS)

The purpose of this study was to evaluate the influence of different light sources for in-office bleaching on surface microhardness of human enamel. One hundred and five blocks of third molars were distributed among seven groups. The facial enamel surface of each block was polished and baseline Knoop microhardness of enamel was assessed with a load of 25 g for 5 s. Subsequently, the enamel was treated with 35% hydrogen peroxide bleaching agent and photo-activated with halogen light (group A) during 38 s, LED (group B) during 360 s, and high intensity diode laser (group C) during 4 s. The groups D (38 s), E (360 s), and F (4 s) were treated with the bleaching agent without photo-activated. The control (group G) was only kept in saliva without any treatment. Microhardness was reassessed after 1 day of the bleaching treatment, and after 7 and 21 days storage in artificial saliva. The mean percentage and standard deviation of microhardness in Knoop Hardness Number were: A 97.8 13.1 KHN; B 95.5 12.7 KHN; C 84.2 13.6 KHN; D 128.6 20.5 KHN; E 133.9 14.2 KHN; F 123.9 14.2 KHN; G 129.8 18.8 KHN. Statistical analysis ( p < 0.05; Tukey test) showed that microhardness percentage values were significantly lower in the groups irradiated with light when compared with the non-irradiated groups. Furthermore, the non-irradiated groups showed that saliva was able to enhance the microhardness during the measurement times. The enamel microhardness was decreased when light sources were used during the bleaching process and the artificial saliva was able to increase microhardness when no light was used.

Kabbach, W.; Zezell, D. M.; Bandca, M. C.; Andrade, M. F.

2010-07-01

383

Influence of green, red and blue light emitting diodes on multiprotein complex proteins and photosynthetic activity under different light intensities in lettuce leaves (Lactuca sativa L.).  

PubMed

The objective of this study was to investigate the response of light emitting diodes (LEDs) at different light intensities (70 and 80 for green LEDs, 88 and 238 for red LEDs and 80 and 238 ?mol m-2 s-1 for blue LEDs) at three wavelengths in lettuce leaves. Lettuce leaves were exposed to (522 nm), red (639 nm) and blue (470 nm) LEDs of different light intensities. Thylakoid multiprotein complex proteins and photosynthetic metabolism were then investigated. Biomass and photosynthetic parameters increased with an increasing light intensity under blue LED illumination and decreased when illuminated with red and green LEDs with decreased light intensity. The expression of multiprotein complex proteins including PSII-core dimer and PSII-core monomer using blue LEDs illumination was higher at higher light intensity (238 ?mol m-2 s-1) and was lowered with decreased light intensity (70-80 ?mol m-2 s-1). The responses of chloroplast sub-compartment proteins, including those active in stomatal opening and closing, and leaf physiological responses at different light intensities, indicated induced growth enhancement upon illumination with blue LEDs. High intensity blue LEDs promote plant growth by controlling the integrity of chloroplast proteins that optimize photosynthetic performance in the natural environment. PMID:24642884

Muneer, Sowbiya; Kim, Eun Jeong; Park, Jeong Suk; Lee, Jeong Hyun

2014-01-01

384

Characterization of a light-responding trans-activator responsible for differentially controlling reaction center and light-harvesting-I gene expression in Rhodobacter capsulatus.  

PubMed Central

The purple nonsulfur photosynthetic bacterium Rhodobacter capsulatus regulates synthesis of its photosystem in response to two environmental stimuli, oxygen tension and light intensity. Here we describe the identification and characterization of the trans-acting regulatory gene hvrA, which we show is involved in differentially controlling reaction center and light-harvesting gene expression in response to alterations in light intensity. An hvrA mutant strain is shown to lack the capability to trans-activate light-harvesting-I and reaction center gene expression but retain normal light-harvesting-II and photopigment regulation, in response to a reduction in light intensity. As a consequence of altered expression, hvrA mutant strains exhibit reduced photosynthetic growth capabilities under dim-light conditions. The results of this study and additional studies indicate that regulated synthesis of the photosystem involves complex sets of overlapping regulatory circuits that differentially control photosystem gene expression in response to environmental stimuli such as oxygen tension and light intensity. Images PMID:7961455

Buggy, J J; Sganga, M W; Bauer, C E

1994-01-01

385

Influence of Green, Red and Blue Light Emitting Diodes on Multiprotein Complex Proteins and Photosynthetic Activity under Different Light Intensities in Lettuce Leaves (Lactuca sativa L.)  

PubMed Central

The objective of this study was to investigate the response of light emitting diodes (LEDs) at different light intensities (70 and 80 for green LEDs, 88 and 238 for red LEDs and 80 and 238 ?mol m?2 s?1 for blue LEDs) at three wavelengths in lettuce leaves. Lettuce leaves were exposed to (522 nm), red (639 nm) and blue (470 nm) LEDs of different light intensities. Thylakoid multiprotein complex proteins and photosynthetic metabolism were then investigated. Biomass and photosynthetic parameters increased with an increasing light intensity under blue LED illumination and decreased when illuminated with red and green LEDs with decreased light intensity. The expression of multiprotein complex proteins including PSII-core dimer and PSII-core monomer using blue LEDs illumination was higher at higher light intensity (238 ?mol m?2 s?1) and was lowered with decreased light intensity (7080 ?mol m?2 s?1). The responses of chloroplast sub-compartment proteins, including those active in stomatal opening and closing, and leaf physiological responses at different light intensities, indicated induced growth enhancement upon illumination with blue LEDs. High intensity blue LEDs promote plant growth by controlling the integrity of chloroplast proteins that optimize photosynthetic performance in the natural environment. PMID:24642884

Muneer, Sowbiya; Kim, Eun Jeong; Park, Jeong Suk; Lee, Jeong Hyun

2014-01-01

386

Antileishmanial effect of silver nanoparticles and their enhanced antiparasitic activity under ultraviolet light  

PubMed Central

Leishmaniasis is a protozoan vector-borne disease and is one of the biggest health problems of the world. Antileishmanial drugs have disadvantages such as toxicity and the recent development of resistance. One of the best-known mechanisms of the antibacterial effects of silver nanoparticles (Ag-NPs) is the production of reactive oxygen species to which Leishmania parasites are very sensitive. So far no information about the effects of Ag-NPs on Leishmania tropica parasites, the causative agent of leishmaniasis, exists in the literature. The aim of this study was to investigate the effects of Ag-NPs on biological parameters of L. tropica such as morphology, metabolic activity, proliferation, infectivity, and survival in host cells, in vitro. Consequently, parasite morphology and infectivity were impaired in comparison with the control. Also, enhanced effects of Ag-NPs were demonstrated on the morphology and infectivity of parasites under ultraviolet (UV) light. Ag-NPs demonstrated significant antileishmanial effects by inhibiting the proliferation and metabolic activity of promastigotes by 1.5- to threefold, respectively, in the dark, and 2- to 6.5-fold, respectively, under UV light. Of note, Ag-NPs inhibited the survival of amastigotes in host cells, and this effect was more significant in the presence of UV light. Thus, for the first time the antileishmanial effects of Ag-NPs on L. tropica parasites were demonstrated along with the enhanced antimicrobial activity of Ag-NPs under UV light. Determination of the antileishmanial effects of Ag-NPs is very important for the further development of new compounds containing nanoparticles in leishmaniasis treatment. PMID:22114501

Allahverdiyev, Adil M; Abamor, Emrah Sefik; Bagirova, Malahat; Ustundag, Cem B; Kaya, Cengiz; Kaya, Figen; Rafailovich, Miriam

2011-01-01

387

Antileishmanial effect of silver nanoparticles and their enhanced antiparasitic activity under ultraviolet light.  

PubMed

Leishmaniasis is a protozoan vector-borne disease and is one of the biggest health problems of the world. Antileishmanial drugs have disadvantages such as toxicity and the recent development of resistance. One of the best-known mechanisms of the antibacterial effects of silver nanoparticles (Ag-NPs) is the production of reactive oxygen species to which Leishmania parasites are very sensitive. So far no information about the effects of Ag-NPs on Leishmania tropica parasites, the causative agent of leishmaniasis, exists in the literature. The aim of this study was to investigate the effects of Ag-NPs on biological parameters of L. tropica such as morphology, metabolic activity, proliferation, infectivity, and survival in host cells, in vitro. Consequently, parasite morphology and infectivity were impaired in comparison with the control. Also, enhanced effects of Ag-NPs were demonstrated on the morphology and infectivity of parasites under ultraviolet (UV) light. Ag-NPs demonstrated significant antileishmanial effects by inhibiting the proliferation and metabolic activity of promastigotes by 1.5- to threefold, respectively, in the dark, and 2- to 6.5-fold, respectively, under UV light. Of note, Ag-NPs inhibited the survival of amastigotes in host cells, and this effect was more significant in the presence of UV light. Thus, for the first time the antileishmanial effects of Ag-NPs on L. tropica parasites were demonstrated along with the enhanced antimicrobial activity of Ag-NPs under UV light. Determination of the antileishmanial effects of Ag-NPs is very important for the further development of new compounds containing nanoparticles in leishmaniasis treatment. PMID:22114501

Allahverdiyev, Adil M; Abamor, Emrah Sefik; Bagirova, Malahat; Ustundag, Cem B; Kaya, Cengiz; Kaya, Figen; Rafailovich, Miriam

2011-01-01

388

Floating seal system for rotary devices  

DOEpatents

This invention relates to a floating seal system for rotary devices to reduce gas leakage around the rotary device in a duct and across the face of the rotary device to an adjacent duct. The peripheral seal bodies are made of resilient material having a generally U-shaped cross section wherein one of the legs is secured to a support member and the other of the legs forms a contacting seal against the rotary device. The legs of the peripheral seal form an extended angle of intersection of about 10[degree] to about 30[degree] in the unloaded condition to provide even sealing forces around the periphery of the rotary device. The peripheral seal extends around the periphery of the support member except where intersected by radial seals which reduce gas leakage across the face of the rotary device and between adjacent duct portions. The radial seal assembly is fabricated from channel bars, the smaller channel bar being secured to the divider of the support member and a larger inverted rigid floating channel bar having its legs freely movable over the legs of the smaller channel bar forming therewith a tubular channel. A resilient flexible tube is positioned within the tubular channel for substantially its full length to reduce gas leakage across the tubular channel. A spacer extends beyond the face of the floating channel near each end of the floating channel a distance to provide desired clearance between the floating channel and the face of the rotary device. 5 figs.

Banasiuk, H.A.

1983-08-23

389

Battery charging in float vs. cycling environments  

SciTech Connect

In lead-acid battery systems, cycling systems are often managed using float management strategies. There are many differences in battery management strategies for a float environment and battery management strategies for a cycling environment. To complicate matters further, in many cycling environments, such as off-grid domestic power systems, there is usually not an available charging source capable of efficiently equalizing a lead-acid battery let alone bring it to a full state of charge. Typically, rules for battery management which have worked quite well in a floating environment have been routinely applied to cycling batteries without full appreciation of what the cycling battery really needs to reach a full state of charge and to maintain a high state of health. For example, charge target voltages for batteries that are regularly deep cycled in off-grid power sources are the same as voltages applied to stand-by systems following a discharge event. In other charging operations equalization charge requirements are frequently ignored or incorrectly applied in cycled systems which frequently leads to premature capacity loss. The cause of this serious problem: the application of float battery management strategies to cycling battery systems. This paper describes the outcomes to be expected when managing cycling batteries with float strategies and discusses the techniques and benefits for the use of cycling battery management strategies.

COREY,GARTH P.

2000-04-20

390

Floating seal system for rotary devices  

DOEpatents

This invention relates to a floating seal system for rotary devices to reduce gas leakage around the rotary device in a duct and across the face of the rotary device to an adjacent duct. The peripheral seal bodies are made of resilient material having a generally U-shaped cross section wherein one of the legs is secured to a support member and the other of the legs forms a contacting seal against the rotary device. The legs of the peripheral seal form an extended angle of intersection of about 10.degree. to about 30.degree. in the unloaded condition to provide even sealing forces around the periphery of the rotary device. The peripheral seal extends around the periphery of the support member except where intersected by radial seals which reduce gas leakage across the face of the rotary device and between adjacent duct portions. The radial seal assembly is fabricated from channel bars, the smaller channel bar being secured to the divider of the support member and a larger inverted rigid floating channel bar having its legs freely movable over the legs of the smaller channel bar forming therewith a tubular channel. A resilient flexible tube is positioned within the tubular channel for substantially its full length to reduce gas leakage across the tubular channel. A spacer extends beyond the face of the floating channel near each end of the floating channel a distance to provide desired clearance between the floating channel and the face of the rotary device.

Banasiuk, Hubert A. (Chicago, IL)

1983-01-01

391

Light-evoked synaptic activity of retinal ganglion and amacrine cells is regulated in developing mouse retina.  

PubMed

Recent studies have shown a continued maturation of visual responsiveness and synaptic activity of retina after eye opening, including the size of receptive fields of retinal ganglion cells (RGCs), light-evoked synaptic output of RGCs, bipolar cell spontaneous synaptic inputs to RGCs, and the synaptic connections between RGCs and ON and OFF bipolar cells. Light deprivation retarded some of these age-dependent changes. However, many other functional and morphological features of RGCs are not sensitive to visual experience. To determine whether light-evoked synaptic responses of RGCs undergo developmental change, we directly examined the light-evoked synaptic inputs from ON and OFF synaptic pathways to RGCs in developing retinas, and found that both light-evoked excitatory and inhibitory synaptic currents decreased, but not increased, with age. We also examined the light-evoked synaptic inputs from ON and OFF synaptic pathways to amacrine cells in developing retinas and found that the light-evoked synaptic input of amacrine cells is also downregulated in developing mouse retina. Different from the developmental changes of RGC spontaneous synaptic activity, dark rearing has little effect on the developmental changes of light-evoked synaptic activity of both RGCs and amacrine cells. Therefore, we concluded that the synaptic mechanisms mediating spontaneous and light-evoked synaptic activity of RGCs and amacrine cells are likely to be different. PMID:21091802

He, Quanhua; Wang, Ping; Tian, Ning

2011-01-01

392

Active control of slow light on a chip with photonic crystal waveguides  

NASA Astrophysics Data System (ADS)

It is known that light can be slowed down in dispersive materials near resonances. Dramatic reduction of the light group velocity-and even bringing light pulses to a complete halt-has been demonstrated recently in various atomic and solid state systems, where the material absorption is cancelled via quantum optical coherent effects. Exploitation of slow light phenomena has potential for applications ranging from all-optical storage to all-optical switching. Existing schemes, however, are restricted to the narrow frequency range of the material resonance, which limits the operation frequency, maximum data rate and storage capacity. Moreover, the implementation of external lasers, low pressures and/or low temperatures prevents miniaturization and hinders practical applications. Here we experimentally demonstrate an over 300-fold reduction of the group velocity on a silicon chip via an ultra-compact photonic integrated circuit using low-loss silicon photonic crystal waveguides that can support an optical mode with a submicrometre cross-section. In addition, we show fast (~100ns) and efficient (2mW electric power) active control of the group velocity by localized heating of the photonic crystal waveguide with an integrated micro-heater.

Vlasov, Yurii A.; O'Boyle, Martin; Hamann, Hendrik F.; McNab, Sharee J.

2005-11-01

393

Effects of molecular asymmetry of optically active molecules on the polarization properties of multiply scattered light  

NASA Astrophysics Data System (ADS)

The use of polarized light for investigation of optically turbid systems has generated much recent interest since it has been shown that multiple scattering does not fully scramble the incident polarization states. It is possible under some conditions to measure polarization signals in diffusely scattered light, and use this information to characterize the structure or composition of the turbid medium. Furthermore, the idea of quantitative detection of optically active (chiral) molecules contained in such a system is attractive, particularly in clinical medicine where it may contribute to the development of a non-invasive method of glucose sensing in diabetic patients. This study uses polarization modulation and synchronous detection in the perpendicular and in the exact backscattering orientations to detect scattered light from liquid turbid samples containing varying amounts of L and D (left and right) isomeric forms of a chiral sugar. Polarization preservation increased with chiral concentrations in both orientations. In the perpendicular orientation, the optical rotation of the linearly polarized fraction also increased with the concentration of chiral solute, but in different directions for the two isomeric forms. There was no observed optical rotation in the exact backscattering geometry for either isomer. The presence of the chiral species is thus manifest in both detection directions, but the sense of the chiral asymmetry is not resolvable in retroreflection. The experiments show that useful information may be extracted from turbid chiral samples using polarized light.

Vitkin, I. Alex; Laszlo, Richard D.; Whyman, Claire L.

2002-02-01

394

Unfolded protein response activation reduces secretion and extracellular aggregation of amyloidogenic immunoglobulin light chain  

PubMed Central

Light-chain amyloidosis (AL) is a degenerative disease characterized by the extracellular aggregation of a destabilized amyloidogenic Ig light chain (LC) secreted from a clonally expanded plasma cell. Current treatments for AL revolve around ablating the cancer plasma cell population using chemotherapy regimens. Unfortunately, this approach is limited to the ?70% of patients who do not exhibit significant organ proteotoxicity and can tolerate chemotherapy. Thus, identifying new therapeutic strategies to alleviate LC organ proteotoxicity should allow AL patients with significant cardiac and/or renal involvement to subsequently tolerate established chemotherapy treatments. Using a small-molecule screening approach, the unfolded protein response (UPR) was identified as a cellular signaling pathway whose activation selectively attenuates secretion of amyloidogenic LC, while not affecting secretion of a nonamyloidogenic LC. Activation of the UPR-associated transcription factors XBP1s and/or ATF6 in the absence of stress recapitulates the selective decrease in amyloidogenic LC secretion by remodeling the endoplasmic reticulum proteostasis network. Stress-independent activation of XBP1s, or especially ATF6, also attenuates extracellular aggregation of amyloidogenic LC into soluble aggregates. Collectively, our results show that stress-independent activation of these adaptive UPR transcription factors offers a therapeutic strategy to reduce proteotoxicity associated with LC aggregation. PMID:25157167

Cooley, Christina B.; Ryno, Lisa M.; Plate, Lars; Morgan, Gareth J.; Hulleman, John D.; Kelly, Jeffery W.; Wiseman, R. Luke

2014-01-01

395

Development of a Vsible-Light-Active Film for Direct Solar Energy Storage  

NASA Astrophysics Data System (ADS)

We conceived of a two-compartment photocatalytic assembly for direct storage of solar energy as chemical potential. Our approach was to maintain reductant and oxidant in separate compartments and develop a visible light (wavelength >400nm) photo-active film to effect an uphill photoreaction between compartments. A proton exchange membrane was included in the assembly to complete the electrical circuit. Towards obtaining a working prototype of the assembly, we developed a freeze-drying method to adhere visible-light photoactive nanoparticles to a self- standing, non-porous and conductive indium tin oxide-polyvinylidene difluoride (ITO-PVDF) support film, developed in-house. We explored the possibility of employing an iron-rich metal oxide as the photocatalytic component of the film and several were explored utilizing the sodium tartrate-assisted photoreduction of Cr(VI) to Cr(III). Although the Fe2O3-coated TiO2 nanoparticles were active for photoreduction, the initial reaction rate was modest and was slowed by substantial deactivation, making it unsuitable as a photo-active material for the composite film. A complete, two-compartment assembly was prepared using cadmium sulfide (CdS) and preliminarily examined for the Cr(VI) probe reaction, however, no catalytic activity was observed. To identify the reason(s) for this observation, further testing of the apparatus and the composite film is required.

Salazar, Audrey

396

Secular Light Curve of 2P/Encke: A Comet Active At Aphelion  

E-print Network

We present the secular light curve of comet 2P/Encke in two phase spaces, the log plot, and the time plot. The main conclusions of this work are: a) The comet shows activity at perihelion and aphelion, caused by two different active areas: Source 1, close to the South pole, active at perihelion, and Source 2, at the North pole, centered at aphelion. b) More than 18 physical parameters are measured from the secular light curves, many of them new, and are listed in the individual plots of the comet. Specifically we find for Source 1 the location of the turn on and turn off points of activity, RON= -1.63+-0.03 AU, ROFF= +1.49+-0.20 AU, TON= -87+-5 d, TOFF= +94+-15 d, the time lag, LAG(q)= 6+-1 d, the total active time, TACTIVITY= 181+-16 d, and the amplitude of the secular light curve, ASEC(1,1) = 4.8+-0.1 mag. c) From this information the photometric age and the time-age defined in Ferrin (Icarus 178, 493-516, 2005a, and Icarus, 185, 523-543, 2006), can be calculated, and we find P-AGE=97+-8 comet years and T-AGE= 103+-9 comet years (cy). Thus comet 2P/Encke is an old comet entering the methuselah stage (100 cy < age). d) The activity at aphelion (Source 2), extends for TACTIVITY = 815+-30 d and the amplitude of the secular light curve is ASEC (1,Q) = 3.0+-0.2 mag. e) From a new phase diagram an absolute magnitude and phase coefficient for the nucleus are determined, and we find RNUC(1,1,0)= 15.05+-0.14, and betha= 0.066+-0.003. From this data we find a nucleus effective diameter DEFFE = 5.12(+2.5;-1.7) km. These values are not much different from previous determinations but exhibit smaller errors. Additional results appear in the full abstract.

Ignacio Ferrin

2008-06-12

397

Accurate measurement of volume and shape of resting and activated blood platelets from light scattering  

NASA Astrophysics Data System (ADS)

We introduce a novel approach for determination of volume and shape of individual blood platelets modeled as an oblate spheroid from angle-resolved light scattering with flow-cytometric technique. The light-scattering profiles (LSPs) of individual platelets were measured with the scanning flow cytometer and the platelet characteristics were determined from the solution of the inverse light-scattering problem using the precomputed database of theoretical LSPs. We revealed a phenomenon of parameter compensation, which is partly explained in the framework of anomalous diffraction approximation. To overcome this problem, additional a priori information on the platelet refractive index was used. It allowed us to determine the size of each platelet with subdiffraction precision and independent of the particular value of the platelet aspect ratio. The shape (spheroidal aspect ratio) distributions of platelets showed substantial differences between native and activated by 10 ?M adenosine diphosphate samples. We expect that the new approach may find use in hematological analyzers for accurate measurement of platelet volume distribution and for determination of the platelet activation efficiency.

Moskalensky, Alexander E.; Yurkin, Maxim A.; Konokhova, Anastasiya I.; Strokotov, Dmitry I.; Nekrasov, Vyacheslav M.; Chernyshev, Andrei V.; Tsvetovskaya, Galina A.; Chikova, Elena D.; Maltsev, Valeri P.

2013-01-01

398

Dark/light modulation of ribulose bisphosphate carboxylase activity in plants from different photosynthetic categories  

SciTech Connect

Ribulose bisphosphate carboxylase/oxygenase (RuBPCase) from several plants had substantially greater activity in extracts from light-exposed leaves than dark leaves, even when the extracts were incubated in vitro with saturating HCO/sub 3//sup -/ and Mg/sup 2 +/ concentrations. This occurred in Glycine max, Lycopersicon esculentum, Nicotiana tabacum, Panicum bisulcatum, and P. hylaeicum (C/sub 3/); P. maximum (C/sub 4/ phosphoenolpyruvate carboxykinase); P. milioides (C/sub 3//C/sub 4/); and Bromelia pinguin and Ananas comosus (Crassulacean acid metabolism). Little or no difference between light and dark leaf extracts of RuBPCase was observed in Triticum aestivum (C/sub 3/); P. miliaceum (C/sub 4/ NAD malic enzyme); Zea mays and Sorghum bicolor (C/sub 4/ NADP malic enzyme); Moricandia arvensis (C/sub 3//C/sub 4/); and Hydrilla verticillata (submersed aquatic macrophyte). It is concluded that, in many plants, especially Crassulacean acid metabolism and C/sub 3/ species, a large fraction of ribulose-1,5-bisphosphate carboxylase/oxygenase in the dark is in an inactivatable state that cannot respond to CO/sub 2/ and Mg/sup 2 +/ activation, but which can be converted to an activatable state upon exposure of the leaf to light. 16 references, 2 tables.

Vu, J.C.V.; Allen, L.H. Jr.; Bowes, G.

1984-11-01

399

Visible-light-driven CO2 reduction with carbon nitride: enhancing the activity of ruthenium catalysts.  

PubMed

A heterogeneous photocatalyst system that consists of a ruthenium complex and carbon nitride (C3N4), which act as the catalytic and light-harvesting units, respectively, was developed for the reduction of CO2 into formic acid. Promoting the injection of electrons from C3N4 into the ruthenium unit as well as strengthening the electronic interactions between the two units enhanced its activity. The use of a suitable solvent further improved the performance, resulting in a turnover number of greater than 1000 and an apparent quantum yield of 5.7% at 400?nm. These are the best values that have been reported for heterogeneous photocatalysts for CO2 reduction under visible-light irradiation to date. PMID:25565575

Kuriki, Ryo; Sekizawa, Keita; Ishitani, Osamu; Maeda, Kazuhiko

2015-02-16

400

Earthquake lights and the stress-activation of positive hole charge carriers in rocks  

USGS Publications Warehouse

Earthquake-related luminous phenomena (also known as earthquake lights) may arise from (1) the stress-activation of positive hole (p-hole) charge carriers in igneous rocks and (2) the accumulation of high charge carrier concentrations at asperities in the crust where the stress rates increase very rapidly as an earthquake approaches. It is proposed that, when a critical charge carrier concentration is reached, the p-holes form a degenerated solid state plasma that can break out of the confined rock volume and propagate as a rapidly expanding charge cloud. Upon reaching the surface the charge cloud causes dielectric breakdown at the air-rock interface, i.e. corona discharges, accompanied by the emission of light and high frequency electromagnetic radiation. ?? 2006 Elsevier Ltd. All rights reserved.

St-Laurent, F.; Derr, J.S.; Freund, F.T.

2006-01-01

401

Preparation of hollow porous Cu2O microspheres and photocatalytic activity under visible light irradiation  

PubMed Central

Cu2O p-type semiconductor hollow porous microspheres have been prepared by using a simple soft-template method at room temperature. The morphology of as-synthesized samples is hollow spherical structures with the diameter ranging from 200 to 500?nm, and the surfaces of the spheres are rough, porous and with lots of channels and folds. The photocatalytic activity of degradation of methyl orange (MO) under visible light irradiation was investigated by UV-visible spectroscopy. The results show that the hollow porous Cu2O particles were uniform in diameters and have an excellent ability in visible light-induced degradation of MO. Meanwhile, the growth mechanism of the prepared Cu2O was also analyzed. We find that sodium dodecyl sulfate acted the role of soft templates in the synthesis process. The hollow porous structure was not only sensitive to the soft template but also to the amount of reagents. PMID:22738162

2012-01-01

402

Verifying floating-point programs with constraint programming and abstract interpretation techniques  

E-print Network

Verifying floating-point programs with constraint programming and abstract interpretation approach for verifying programs with floating-point computations. Value analysis mainly relies on abstract benchmarks. Keywords Program verification · Floating-point computation · Constraint solving over floating

Recanati, Catherine

403

40 CFR 426.50 - Applicability; description of the float glass manufacturing subcategory.  

Code of Federal Regulations, 2011 CFR

...SOURCE CATEGORY Float Glass Manufacturing Subcategory...Applicability; description of the float glass manufacturing subcategory...are mixed, melted in a furnace, and floated on a molten tin bath to produce float...

2011-07-01

404

40 CFR 426.50 - Applicability; description of the float glass manufacturing subcategory.  

Code of Federal Regulations, 2010 CFR

...SOURCE CATEGORY Float Glass Manufacturing Subcategory...Applicability; description of the float glass manufacturing subcategory...are mixed, melted in a furnace, and floated on a molten tin bath to produce float...

2010-07-01

405

40 CFR 426.50 - Applicability; description of the float glass manufacturing subcategory.  

Code of Federal Regulations, 2013 CFR

...SOURCE CATEGORY Float Glass Manufacturing Subcategory...Applicability; description of the float glass manufacturing subcategory...are mixed, melted in a furnace, and floated on a molten tin bath to produce float...

2013-07-01

406

40 CFR 426.50 - Applicability; description of the float glass manufacturing subcategory.  

Code of Federal Regulations, 2014 CFR

...SOURCE CATEGORY Float Glass Manufacturing Subcategory...Applicability; description of the float glass manufacturing subcategory...are mixed, melted in a furnace, and floated on a molten tin bath to produce float...

2014-07-01

407

40 CFR 426.50 - Applicability; description of the float glass manufacturing subcategory.  

Code of Federal Regulations, 2012 CFR

...SOURCE CATEGORY Float Glass Manufacturing Subcategory...Applicability; description of the float glass manufacturing subcategory...are mixed, melted in a furnace, and floated on a molten tin bath to produce float...

2012-07-01

408

The influence of negative ionization of the air on motor activity in Syrian hamsters ( Masocricetus auratus Waterhouse) in light conditions  

NASA Astrophysics Data System (ADS)

The motor activity of Syrian hamsters ( Mesocricetus auratus Waterhouse) under the influence of negative ionization of the atmosphere applied for 10, 20 or 30 min per day was investigated. An ionizer with output of 14000 light negative ions per 1 cm3 of air was used. Studies carried out in the light phase of a 12?12 h light/dark regime revealed a relation between the reaction of the animal and the time of day at which ionization was applied. Ionization for 20 or 30 min in the light phase decreased motor activity, while 10 min of ionization increased it compared to control animals. Ionization in the dark phase gave a more distinct rise in activity than that applied in the light phase for all three durations of ionization.

Lenkiewicz, Zofia; Dabrowska, Barbara; Schiffer, Zofia

1989-12-01

409

An in vitro thermal analysis during different light-activated hydrogen peroxide bleaching  

NASA Astrophysics Data System (ADS)

This study measured the critical temperature reaching time and also the variation of temperature in the surface of the cervical region and within the pulp chamber of human teeth submitted to dental bleaching using 35% hydrogen peroxide gel activated by three different light sources. The samples were randomly divided into 3 groups ( n = 15), according to the catalyst light source: Halogen Light (HL), High Intensity Diode Laser (DL), and Light Emmited Diode (LED). The results of temperature variation were submitted to the analysis of variance and Tukey test with p < 0.05. The temperature increase (mean value and standard deviation) inside the pulp chamber for the HL group was 6.8 2.8C; for the DL group was 15.3 8.8C; and for the LED group was 1.9 1.0C for. The temperature variation (mean value and standard deviation) on the tooth surface, for the group irradiated with HL was 9.1 2.2C; for the group irradiated with DL were 25.7 18.9C; and for the group irradiated with LED were 2.6 1.4C. The mean temperature increase values were significantly higher for the group irradiated with DL when compared with groups irradiated with HL and LED ( p < 0.05). When applying the inferior limits of the interval of confidence of 95%, an application time of 38.7 s was found for HL group, and 4.4 s for DL group. The LED group did not achieve the critical temperatures for pulp or the periodontal, even when irradiated for 360 s. The HL and DL light sources may be used for dental bleaching for a short period of time. The LED source did not heat the target tissues significantly within the parameters used in this study.

Kabbach, W.; Zezell, D. M.; Bandca, M. C.; Pereira, T. M.; Andrade, M. F.

2010-09-01

410

FHY1 Mediates Nuclear Import of the Light-Activated Phytochrome A Photoreceptor  

PubMed Central

The phytochrome (phy) family of photoreceptors is of crucial importance throughout the life cycle of higher plants. Light-induced nuclear import is required for most phytochrome responses. Nuclear accumulation of phyA is dependent on two related proteins called FHY1 (Far-red elongated HYpocotyl 1) and FHL (FHY1 Like), with FHY1 playing the predominant function. The transcription of FHY1 and FHL are controlled by FHY3 (Far-red elongated HYpocotyl 3) and FAR1 (FAr-red impaired Response 1), a related pair of transcription factors, which thus indirectly control phyA nuclear accumulation. FHY1 and FHL preferentially interact with the light-activated form of phyA, but the mechanism by which they enable photoreceptor accumulation in the nucleus remains unsolved. Sequence comparison of numerous FHY1-related proteins indicates that only the NLS located at the N-terminus and the phyA-interaction domain located at the C-terminus are conserved. We demonstrate that these two parts of FHY1 are sufficient for FHY1 function. phyA nuclear accumulation is inhibited in the presence of high levels of FHY1 variants unable to enter the nucleus. Furthermore, nuclear accumulation of phyA becomes light- and FHY1-independent when an NLS sequence is fused to phyA, strongly suggesting that FHY1 mediates nuclear import of light-activated phyA. In accordance with this idea, FHY1 and FHY3 become functionally dispensable in seedlings expressing a constitutively nuclear version of phyA. Our data suggest that the mechanism uncovered in Arabidopsis is conserved in higher plants. Moreover, this mechanism allows us to propose a model explaining why phyA needs a specific nuclear import pathway. PMID:18670649

Genoud, Thierry; Schweizer, Fabian; Tscheuschler, Anke; Debrieux, Dimitry; Casal, Jorge J.; Schfer, Eberhard; Hiltbrunner, Andreas; Fankhauser, Christian

2008-01-01

411

Improvements in floating point addition/subtraction operations  

DOEpatents

Apparatus is described for decreasing the latency time associated with floating point addition and subtraction in a computer, using a novel bifurcated, pre-normalization/post-normalization approach that distinguishes between differences of floating point exponents.

Farmwald, P.M.

1984-02-24

412

The syntactic and semantic roots of floating quantification  

E-print Network

Through the study of floating quantifiers in a variety of languages, I demonstrate that floating quantification is not a uniform phenomenon and outline a series of puzzles that force us to adopt a two-part analysis. I argue ...

Fitzpatrick, Justin Michael

2006-01-01

413

14 CFR 136.11 - Helicopter floats for over water.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Helicopter floats for over water. 136.11 Section...Air Tour Safety Standards 136.11 Helicopter floats for over water. (a) A helicopter used in commercial air tours over...

2010-01-01

414

14 CFR 136.11 - Helicopter floats for over water.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Helicopter floats for over water. 136.11 Section...Air Tour Safety Standards 136.11 Helicopter floats for over water. (a) A helicopter used in commercial air tours over...

2012-01-01

415

14 CFR 136.11 - Helicopter floats for over water.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Helicopter floats for over water. 136.11 Section...Air Tour Safety Standards 136.11 Helicopter floats for over water. (a) A helicopter used in commercial air tours over...

2011-01-01

416

14 CFR 136.11 - Helicopter floats for over water.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 2014-01-01 false Helicopter floats for over water. 136.11 Section...Air Tour Safety Standards 136.11 Helicopter floats for over water. (a) A helicopter used in commercial air tours over...

2014-01-01

417

14 CFR 136.11 - Helicopter floats for over water.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Helicopter floats for over water. 136.11 Section...Air Tour Safety Standards 136.11 Helicopter floats for over water. (a) A helicopter used in commercial air tours over...

2013-01-01

418

Phosphoenolpyruvate Carboxylase Kinase in Tobacco Leaves Is Activated by Light in a Similar but Not Identical Way as in Maize.  

PubMed Central

We have previously reported the partial purification of a Ca2+- independent phosphoenolpyruvate carboxylase (PEPC) protein-serine/threonine kinase (PEPC-PK) from illuminated leaves of N-sufficient tobacco (Nicotiana tabacum L.) plants (Y.-H. Wang, R. Chollet [1993] FEBS Lett 328: 215-218). We now report that this C3 PEPC-kinase is reversibly light activated in vivo in a time-dependent manner. As the kinase becomes light activated, the activity and L-malate sensitivity of its target protein increases and decreases, respectively. The light activation of tobacco PEPC-PK is prevented by pretreatment of detached leaves with various photosynthesis and cytosolic protein-synthesis inhibitors. Similarly, specific inhibitors of glutamine synthetase block the light activation of tobacco leaf PEPC-kinase under both photorespiratory and nonphotorespiratory conditions. This striking effect is partially and specifically reversed by exogenous glutamine, whereas it has no apparent effect on the light activation of the maize (Zea mays L.) leaf kinase. Using an in situ "activity-gel" phosphorylation assay, we have identified two major Ca2+-independent PEPC-kinase catalytic polypeptides in illuminated tobacco leaves that have the same molecular masses (approximately 30 and 37 kD) as found in illuminated maize leaves. Collectively, these results indicate that the phosphorylation of PEPC in N-sufficient leaves of tobacco (C3) and maize (C4) is regulated through similar but not identical light-signal transduction pathways. PMID:12226305

Li, B.; Zhang, X. Q.; Chollet, R.

1996-01-01

419

Effects of light activated in-office bleaching on permeability, microhardness, and mineral content of enamel.  

PubMed

The aim of this study was to evaluate the permeability (PE), microhardness (KHN), and mineral change in enamel after LED/laser activated in-office bleaching. For PE, the coronal portion of premolars (n=51) was subjected to bleaching with 35% hydrogen peroxide (Whiteness HP Maxx, FGM Dental Products, Joinville, SC, Brazil). The samples were stained via the histochemical method, which involves a copper sulphate solution and rubeanic acid. The penetration of dye into the enamel was measured. The KHN of enamel was assessed before treatment, immediately after the bleaching treatment, and again after one week. The calcium and phosphorus content were analyzed with a scanning electron microscope with energy-dispersive X-ray (JSM 6360LV, Jeol Ltd, Tokyo, Japan). The data set from each test was subjected to appropriate parametric statistical analysis (?=0.05). No significant differences were observed for PE in NLA and LA compared to the control group (p=0.98), as well as for calcium (p=0.16) and phosphorus (p=0.80) content. Significant reduction of KHN after bleaching occurred for both groups (p<0.001). After immersion in artificial saliva, the KHN of the enamel for all groups was similar to that seen before bleaching. Light activation during in-office bleaching does not produce significant changes in the enamel compared to a non-light-activated technique. PMID:24815914

Parreiras, S O; Vianna, P; Kossatz, S; Loguercio, A D; Reis, A

2014-01-01

420

A coronagraph based on two spatial light modulators for active amplitude apodizing and phase corrections  

NASA Astrophysics Data System (ADS)

Almost all high-contrast imaging coronagraphs proposed until now are based on passive coronagraph optical components. Recently, Ren and Zhu proposed for the first time a coronagraph that integrates a liquid crystal array (LCA) for the active pupil apodizing and a deformable mirror (DM) for the phase corrections. Here, for demonstration purpose, we present the initial test result of a coronagraphic system that is based on two liquid crystal spatial light modulators (SLM). In the system, one SLM is served as active pupil apodizing and amplitude correction to suppress the diffraction light; another SLM is used to correct the speckle noise that is caused by the wave-front distortions. In this way, both amplitude and phase error can be actively and efficiently compensated. In the test, we use the stochastic parallel gradient descent (SPGD) algorithm to control two SLMs, which is based on the point spread function (PSF) sensing and evaluation and optimized for a maximum contrast in the discovery area. Finally, it has demonstrated a contrast of 10-6 at an inner working angular distance of ~6.2 ?/D, which is a promising technique to be used for the direct imaging of young exoplanets on ground-based telescopes.

Dou, Jiangpei; Ren, Deqing; Zhang, Xi; Zhu, Yongtian; Zhao, Gang; Wu, Zhen; Chen, Rui; Liu, Chengchao; Yang, Feng; Yang, Chao

2014-08-01

421

Monolithic crystalline cladding microstructures for efficient light guiding and beam manipulation in passive and active regimes.  

PubMed

Miniature laser sources with on-demand beam features are desirable devices for a broad range of photonic applications. Lasing based on direct-pump of miniaturized waveguiding active structures offers a low-cost but intriguing solution for compact light-emitting devices. In this work, we demonstrate a novel family of three dimensional (3D) photonic microstructures monolithically integrated in a Nd:YAG laser crystal wafer. They are produced by the femtosecond laser writing, capable of simultaneous light waveguiding and beam manipulation. In these guiding systems, tailoring of laser modes by both passive/active beam splitting and ring-shaped transformation are achieved by an appropriate design of refractive index patterns. Integration of graphene thin-layer as saturable absorber in the 3D laser structures allows for efficient passive Q-switching of tailored laser radiations which may enable miniature waveguiding lasers for broader applications. Our results pave a way to construct complex integrated passive and active laser circuits in dielectric crystals by using femtosecond laser written monolithic photonic chips. PMID:25100561

Jia, Yuechen; Cheng, Chen; Vzquez de Aldana, Javier R; Castillo, Gabriel R; Rabes, Blanca del Rosal; Tan, Yang; Jaque, Daniel; Chen, Feng

2014-01-01

422

Visible light photocatalytic activity of BiVO4 particles with different morphologies  

NASA Astrophysics Data System (ADS)

Bismuth vanadate (BiVO4) particles with different morphologies were synthesized by a one-step hydrothermal process and their optical and photocatalytic properties were investigated. Their crystal structure and microstructures were characterized using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). XRD patterns demonstrate that the as-prepared samples are monoclinic cell. FESEM shows that BiVO4 crystals can be fabricated in different morphologies by simply manipulating the reaction parameters of hydrothermal process. The UV-visible diffuse reflectance spectra (UV-vis DRS) reveal that the band gaps of BiVO4 photocatalysts are about 2.07-2.21 eV. The as-prepared BiVO4 photocatalysts exhibit higher photocatalytic activities in the degradation of rhodamine B (Rh B) under visible light irradiation (? > 420 nm) compared with traditional N-doped TiO2 (N-TiO2). Furthermore, wheat like BiVO4 sample reveals the highest photocatalytic activity. Up to 100% Rh B is decolorized after visible light irradiation for 180 min. The reason for the difference in the photocatalytic activities for BiVO4 samples obtained at different conditions were systematically studied based on their shape, size and the variation of local structure.

Lin, Xue; Yu, Lili; Yan, Lina; Li, Hongji; Yan, Yongsheng; Liu, Chunbo; Zhai, Hongju

2014-06-01

423

Experience the magic of light and color: outreach activity by Universidad del Valle student chapter  

NASA Astrophysics Data System (ADS)

During 2007, the Universidad del Valle Student Chapter presented a proposal for developing an educational outreach activity for children from an underprivileged zone to the Optical Society of America Foundation (OSAF) and to SPIE. The activity was carried out jointly by OSA and SPIE Universidad del Valle Student Chapters in the hillsides of Santiago de Cali, in a zone known as "Pueblo Joven" during 2008. It was aimed to boys and girls with ages between 8 and 13 years and was called "Experience the magic of light and color". The main purpose was to bring the children some basic concepts on optics and to encourage them to explore science through optics. The Universidad del Valle Student Chapters designed a series of talks and practical workshops where children participated in hands-on experiments that easily explain the fundamental concepts of light phenomena. Afterwards the children presented their achievements in a small science fair offered to the community and tried to explain in their own words what they learned and built. In this work, we present the most successful experimental designs and the educational standards we tried to develop with this activity.

Valdes, Claudia; Reyes, Camilo; Osorio, Alberto; Solarte, Efrain

2010-08-01

424

Monolithic crystalline cladding microstructures for efficient light guiding and beam manipulation in passive and active regimes  

PubMed Central

Miniature laser sources with on-demand beam features are desirable devices for a broad range of photonic applications. Lasing based on direct-pump of miniaturized waveguiding active structures offers a low-cost but intriguing solution for compact light-emitting devices. In this work, we demonstrate a novel family of three dimensional (3D) photonic microstructures monolithically integrated in a Nd:YAG laser crystal wafer. They are produced by the femtosecond laser writing, capable of simultaneous light waveguiding and beam manipulation. In these guiding systems, tailoring of laser modes by both passive/active beam splitting and ring-shaped transformation are achieved by an appropriate design of refractive index patterns. Integration of graphene thin-layer as saturable absorber in the 3D laser structures allows for efficient passive Q-switching of tailored laser radiations which may enable miniature waveguiding lasers for broader applications. Our results pave a way to construct complex integrated passive and active laser circuits in dielectric crystals by using femtosecond laser written monolithic photonic chips. PMID:25100561

Jia, Yuechen; Cheng, Chen; Vzquez de Aldana, Javier R.; Castillo, Gabriel R.; Rabes, Blanca del Rosal; Tan, Yang; Jaque, Daniel; Chen, Feng

2014-01-01

425

Photoactive titania float for disinfection of water; evaluation of cell damage by bioanalytical techniques.  

PubMed

A photoactive float was fabricated with the modified titania to cause a feasible disinfection of water, contaminated with E. coli. The commercially available titania was doped with neodymium by pulverization technique to enhance its activity in sunlight and a multiapproach technique was used to evaluate the extended efficiency of the doped sample. X-ray diffraction patterns depicted the retention of anatase phase on doping and the existence of neodymium was confirmed by the energy dispersive atomic X-ray analysis and the X-ray photoelectron spectroscopy. Transmission electron microscopy and Bruner-Emmett-Teller analysis depicted a marginal increase in the particle size and a decrease in the surface area, respectively. Doping induces semiconductor behavior with lower band energy that could respond to visible light and exhibit better disinfection activity. The "f" and "d" transitions of the lanthanide in doped sample caused new electronic behavior of trapping/detrapping effect together with bandgap narrowing. The amount of malondialdehyde, protein, DNA and RNA released on destruction of E. coli was observed to be 0.915 10(-3) ?g mL(-1), 859.912 ?g mL(-1), 20.173 ?g mL(-1) and 1146.073 ?g mL(-1), respectively. The above analytical methods along with standard plate count method substantiated the enhanced disinfection efficiency of the doped sample in sunlight. PMID:24689654

Shwetharani, R; Jyothi, M S; Laveena, P D; Geetha Balakrishna, R

2014-01-01

426

Upper Limb Muscle and Brain Activity in Light Assembly Task on Different Load Levels  

NASA Astrophysics Data System (ADS)

A study was conducted to investigate the effect of load on upper limb muscles and brain activities in light assembly task. The task was conducted at two levels of load (Low and high). Surface electromyography (EMG) was used to measure upper limb muscle activities of twenty subjects. Electroencephalography (EEG) was simultaneously recorded with EMG to record brain activities from Fz, Pz, O1 and O2 channels. The EMG Mean Power Frequency (MPF) of the right brachioradialis and the left upper trapezius activities were higher on the high-load task compared to low-load task. The EMG MPF values also decrease as time increases, that reflects muscle fatigue. Mean power of the EEG alpha bands for the Fz-Pz channels were found to be higher on the high-load task compared to low-load task, while for the O1-O2 channels, they were higher on the low-load task than on the high-load task. These results indicated that the load levels effect the upper limb muscle and brain activities. The high-load task will increase muscle activities on the right brachioradialis and the left upper tapezius muscles, and will increase the awareness and motivation of the subjects. Whilst the low-load task can generate drowsiness earlier. It signified that the longer the time and the more heavy of the task, the subjects will be more fatigue physically and mentally.

Zadry, Hilma Raimona; Dawal, Siti Zawiah Md.; Taha, Zahari

2010-10-01

427

Notes on floating point number, numerical computations and pitfalls  

E-print Network

Notes on floating point number, numerical computations and pitfalls November 6, 2012 1 Floating point numbers An n-digit floating point number in base has the form x = ±(0.d1d2 · · · dn) ? e where 0. Such a floating point number is called normalised if d1 = 0, or else, d1 = d2 = · · · = dn =. The exponent e

Banerjee, Subhashis

428

Temperature-insensitive, Current Conveyor-based Floating Simulator Topology  

Microsoft Academic Search

A novel circuit for realizing floating inductance, floating capacitance, floating frequency dependent negative resistance (FDNR) and grounded to floating admittance converter depending on the passive component selection is proposed in this paper. The proposed simulator employs second-generation current-controlled current conveyors (CCCIIs), differential voltage current conveyor (DVCC) and only grounded passive elements. The synthesized immittance values are temperature-insensitive. The non-ideal current

M. Siripruchyanun; M. Phattanasak; W. Jaikla

2007-01-01

429

A highly luminescent spiro-anthracenone-based organic light-emitting diode exhibiting thermally activated delayed fluorescence.  

PubMed

Efficient thermally activated delayed fluorescence was observed from a spiro-anthracenone derivative (ACRSA). An organic light-emitting diode containing ACRSA exhibited blue-greenish electroluminescence with a maximum external quantum efficiency of 16.5%. PMID:24071893

Nasu, Keiro; Nakagawa, Tetsuya; Nomura, Hiroko; Lin, Chi-Jen; Cheng, Chien-Hong; Tseng, Mei-Rurng; Yasuda, Takuma; Adachi, Chihaya

2013-11-14

430

Tests of monolithic active pixel sensors at national synchrotron light source  

NASA Astrophysics Data System (ADS)

The paper discusses basic characterization of Monolithic Active Pixel Sensors (MAPS) carried out at the X12A beam-line at National Synchrotron Light Source (NSLS), Upton, NY, USA. The tested device was a MIMOSA V (MV) chip, back-thinned down to the epitaxial layer. This 1M pixels device features a pixel size of 1717 ?m2 and was designed in a 0.6 ?m CMOS process. The X-ray beam energies used range from 5 to 12 keV. Examples of direct X-ray imaging capabilities are presented.

Deptuch, G.; Besson, A.; Carini, G. A.; Siddons, D. P.; Szelezniak, M.; Winter, M.

2007-01-01

431

Graphene-based electrically reconfigurable deep-subwavelength metamaterials for active control of THz light propagation  

NASA Astrophysics Data System (ADS)

This work studies the terahertz light propagation through graphene-based reconfigurable metasurfaces where the unit cell dimensions are much smaller than the terahertz wavelength. The proposed devices, which poses deep-subwavelength unit cell and active region dimensions can operate as amplitude and/or phase modulators in certain specific frequency bands determined by the device geometry. Reconfigurability is attained via electrostatically tuning the optical conductivity of patterned graphene layers, which are strategically located in each unit cell. The ultra-small unit cell dimensions can be advantageous for beam shaping applications.

Arezoomandan, Sara; Yang, Kai; Sensale-Rodriguez, Berardi

2014-08-01

432

Long distance active hyperspectral sensing using high-power near-infrared supercontinuum light source.  

PubMed

A hyperspectral remote sensing instrument employing a novel near-infrared supercontinuum light source has been developed for active illumination and identification of targets. The supercontinuum is generated in a standard normal dispersion multi-mode fiber and has 16 W total optical output power covering 1000 nm to 2300 nm spectral range. A commercial 256-channel infrared spectrometer was used for broadband infrared detection. The feasibility of the presented hyperspectral measurement approach was investigated both indoors and in the field. Reflection spectra from several diffusive targets were successfully measured and a measurement range of 1.5 km was demonstrated. PMID:24664065

Manninen, Albert; Kriinen, Teemu; Parviainen, Tomi; Buchter, Scott; Heili, Miika; Laurila, Toni

2014-03-24

433

Preparation of carbon nanotubes/BiOBr composites with higher visible light photocatalytic activity  

NASA Astrophysics Data System (ADS)

A novel flower-like photocatalyst CNTs/BiOBr was successfully prepared by a facile hydrothermal method. The morphology and the physicochemical properties of the prepared samples were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectrometry (EDX), and UV-visible diffuse reflectance spectroscopy (UV-vis DRS). The photocatalytic activity was evaluated by degradation of Rhodamin B (RhB) dye. It was demonstrated that CNTs/BiOBr photocatalyst could effectively photodegrade RhB under visible light (VL) irradiation.

You, Y. J.; Zhang, Y. X.; Li, R. R.; Li, C. H.

2014-12-01

434

Optical monitoring of selected quasars, Lacertids, and active galaxies in blue light  

SciTech Connect

Optical photometry in blue light of selected bright quasars, Lacertids, active galaxies, and X-ray sources with a 1-m f/15 Cassegrain reflector is reported. The observed magnitude and amplitude for 3C 273, 3C 351, 3C 454.3, 3C 66A, PKS 2141 + 17, BL Lac, OJ287, and Zw0039.5 + 004 are described. The techniques used to collect and reduce the data are discussed. Tables of observed blue magnitudes for the data are provided. 18 references.

Corso, G.J.; Schultz, J.; Dey, A.

1986-12-01

435

Design of efficient thermally activated delayed fluorescence materials for pure blue organic light emitting diodes.  

PubMed

Efficient thermally activated delayed fluorescence (TADF) has been characterized for a carbazole/sulfone derivative in both solutions and doped films. A pure blue organic light emitting diode (OLED) based on this compound demonstrates a very high external quantum efficiency (EQE) of nearly 10% at low current density. Because TADF only occurs in a bipolar system where donor and acceptor centered (3)??* states are close to or higher than the triplet intramolecular charge transfer ((3)CT) state, control of the ?-conjugation length of both donor and acceptor is considered to be as important as breaking the ?-conjugation between them in blue TADF material design. PMID:22931361

Zhang, Qisheng; Li, Jie; Shizu, Katsuyuki; Huang, Shuping; Hirata, Shuzo; Miyazaki, Hiroshi; Adachi, Chihaya

2012-09-12

436

The effect on emotions and brain activity by the direct/indirect lighting in the residential environment.  

PubMed

This study was performed to explore how direct/indirect lighting affects emotions and brain oscillations compared to the direct lighting when brightness and color temperature are controlled. Twenty-eight subjects (12 females; mean age 22.5) participated. The experimental conditions consisted of two lighting environments: direct/indirect lighting (400 lx downlight, 300 lx uplight) and direct lighting (700 lx downlight). On each trial, a luminance environment was presented for 4 min, followed by participants rated their emotional feelings of the lighting environment. EEG data were recorded during the experiment. Spectral analysis was performed for the range of delta, theta, alpha, beta, and gamma ranges. The participants felt cooler and more pleasant and theta oscillations on the F4, F8, T4, and TP7 electrodes were more enhanced in the direct/indirect lighting environment compared to the direct lighting environment. There was significant correlation between the "cool" rating and the theta power of the F8 electrode. The participants felt more pleasant in the direct/indirect lighting environment, indicating that space with direct/indirect lighting modulated subjective perception. Additionally, our results suggest that theta oscillatory activity can be used as a biological marker that reflects emotional status in different lighting environments. PMID:25281545

Shin, Yu-Bin; Woo, Seung-Hyun; Kim, Dong-Hyeon; Kim, Jinseong; Kim, Jae-Jin; Park, Jin Young

2015-01-01

437

Enhanced visible-light photocatalytic activity of active Al?O?/g-C?N? heterojunctions synthesized via surface hydroxyl modification.  

PubMed

Novel Al2O3/g-C3N4 heterojunction photocatalysts were fabricated through ultrasonic dispersion method. Al2O3, obtained via solution combustion, contained amorphous ingredient with lots of defect sites and was used as active component for transferring photo-induced electrons of g-C3N4. G-C3N4 was grafted surface hydroxyl groups in the presence of ammonia aqueous solution to combine with Al2O3 possessing positive charges via hydrogen bond. The XRD, SEM, element map, TEM, HRTEM, FT-IR, and XPS results indicate that these synthesized materials are two-phase hybrids of Al2O3 and g-C3N4 with interaction. The photocatalytic results for the degradation of rhodamine B (RhB) indicate that the most active heterojunction proportion is 60wt.% g-C3N4:40wt.% Al2O3, the visible light photocatalytic activity of which is 3.8 times that of a mechanical mixture. The enhanced performance is attributed to the high separation efficiency of photo-induced electrons from the LUMO of g-C3N4 injected into the defect sites of Al2O3, which is verified by photoluminescence spectroscopy (PL) and surface photovoltage (SPV) measurements. The electron paramagnetic resonance (EPR) signals and radical scavengers trapping experiments reveal holes (h(+)) and superoxide anion radical (O2(-)) are the main active species responsible for the degradation of RhB. PMID:25306536

Li, Fa-Tang; Zhao, Ye; Wang, Qing; Wang, Xiao-Jing; Hao, Ying-Juan; Liu, Rui-Hong; Zhao, Dishun

2015-02-11

438

Free-floating planets from microlensing  

NASA Astrophysics Data System (ADS)

Gravitational microlensing has an unique sensitivity to exoplanets at outside of the snow-line and even exoplanets unbound to any host stars because the technique does not rely on any light from the host but the gravity of the lens. MOA and OGLE collaborations reported the discovery of a population of unbound or distant Jupiter-mass objects, which are almost twice (1.8_{-0.8}^{+1.7}) as common as main-sequence stars, based on two years of gravitational microlensing survey observations toward the Galactic Bulge. These planetary-mass objects have no host stars that can be detected within about ten astronomical units by gravitational microlensing. However a comparison with constraints from direct imaging suggests that most of these planetary-mass objects are not bound to any host star. The such short-timescale unbound planetary candidates have been detected with the similar rate in on-going observations and these groups are working to update the analysis with larger statistics. Recently, there are also discoveries of free-floating planetary mass objects by the direct imaging in young star-forming regions and in the moving groups, but these objects are limited to massive objects of 3 to 15 Jupiter masses.They are more massive than the population found by microlensing. So they may be a different population with the different formation process, either similar with that of stars and brown dwarfs, or formed in proto-planetary disks and subsequently scattered into unbound or very distant orbits. It is important to fill the gap of these mass ranges to fully understand these populations. The Wide Field Infrared Survey Telescope (WFIRST) is the highest ranked recommendation for a large space mission in the recent New Worlds, New Horizons (NWNH) in Astronomy and Astrophysics 2010 Decadal Survey. Exoplanet microlensing program is one of the primary science of WFIRST. WFIRST will find about 3000 bound planets and 2000 unbound planets by the high precision continuous survey 15 min. cadence. WFIRST can complete the statistical census of planetary systems in the Galaxy, from super-Earths beyond the snow-line to gravitationally unbound planets - a discovery space inaccessible to other exoplanet detection techniques.

Sumi, Takahiro

2014-06-01

439

WaveStar multi-float system performance calculation  

E-print Network

. EQUATIONS OF MOTION The equation of motion of floating structures is traditionally obtained by the viewpoint of the float. Furthermore, drag forces for moving structures exists and can be calculated by Morrison's formula to a moving structure added hydrodynamic mass hydrodynamic damping When energy is extracted from the float

440

On the Poset Structure of Floating Codes Mochan Shrestha  

E-print Network

On the Poset Structure of Floating Codes Mochan Shrestha Department of Computer Science Wayne State fundamentally different structures that make designing floating codes a challenge, most notably their structure of their vertex covers. Based on the poset structure, we present a new floating code for arbitrary n, q, k and l

Xu, Lihao

441

CS281: Systems Programming Programming Lab Assignment: The Float Lab  

E-print Network

CS281: Systems Programming Programming Lab Assignment: The Float Lab Introduction The purpose of this assignment is to gain more familiarity with the IEEE floating point format. You will write a small library of floating point routines in assembly in order to compute a desired result. We will also focus on the design

Kretchmar, R. Matthew

442

Waterhyacinth: Florida's Worst Floating Weed1 Lyn A. Gettys2  

E-print Network

SS-AGR-380 Waterhyacinth: Florida's Worst Floating Weed1 Lyn A. Gettys2 1. This document is SS Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension. Introduction Waterhyacinth is a free-floating of waterhyacinth Credits: Lyn Gettys, UF/IFAS #12;2Waterhyacinth: Florida's Worst Floating Weed Classification

Watson, Craig A.

443

Generating Pseudorandom FloatingPoint Values Allen B. Downey  

E-print Network

Generating Pseudo­random Floating­Point Values Allen B. Downey July 25, 2007 Abstract The conventional method for generating a pseudorandom floating­ point value is to generate a pseudorandom integer and divide by a constant (using floating­point arithmetic). The problems with this approach are (1

Downey, Allen B.

444

Formal Verification of Floating-Point Programs Sylvie Boldo  

E-print Network

Formal Verification of Floating-Point Programs Sylvie Boldo INRIA Futurs Sylvie.Boldo@inria.fr Jean of floating-point C programs. It extends an ex- isting tool for the verification of C programs, Caduceus, with new annotations specific to floating-point arithmetic. The Caduceus first-order logic model for C

California at Davis, University of

445

40 CFR 63.1043 - Standards-Separator floating roof.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Standards-Separator floating roof. 63.1043 Section 63.1043... 63.1043 StandardsSeparator floating roof. (a) This section applies...separator or organic-water separator using a floating roof. (b) The separator shall...

2014-07-01

446

FloatBoost Learning and Statistical Face Detection  

E-print Network

FloatBoost Learning and Statistical Face Detection Stan Z. Li, Senior Member, IEEE, and ZhenQiu Zhang Abstract--A novel learning procedure, called FloatBoost, is proposed for learning a boosted classifier for achieving the minimum error rate. FloatBoost learning uses a backtrack mechanism after each

447

A Combined Decimal and Binary Floating-point Divider  

E-print Network

A Combined Decimal and Binary Floating-point Divider Sonia Gonz´alez-Navarro University of M@nvidia.com Abstract--In this paper, we present the hardware design of a combined decimal and binary floating-point divider, based on specifications in the IEEE 754-2008 Standard for Floating- point Arithmetic. In contrast

Nannarelli, Alberto

448

The Floating Column Algorithm for Shaded, Parallel Display of Function  

E-print Network

The Floating Column Algorithm for Shaded, Parallel Display of Function Surfaces without Patches Dan Gordon AbstractÐThe floating column algorithm is a new method for the shaded rendering of function surfaces. Derived from the monochromatic floating horizon algorithm, it uses the partial derivatives

Gordon, Dan

449

Software Model Checking the Precision of Floating-Point Programs  

E-print Network

1 Software Model Checking the Precision of Floating-Point Programs Franjo Ivanci´c, Malay K. Ganai floating-point standard, and the precision loss incurred in such programs. There have been techniques with floating point operations. We generate a mixed integral-real model that is then analyzed by two backend

Sankaranarayanan, Sriram

450

Approximate counting with a floating-point Miklos Csuros  

E-print Network

Approximate counting with a floating-point counter Mikl´os Csur¨os Department of Computer Science revisit the original idea of Morris. We introduce a binary floating-point counter that combines a d for an unbiased estimation of n with a standard deviation of about 0.6 · n2-d/2 . We analyze the floating

Csürös, Miklós

451

When FPGAs are better at floating-point than microprocessors  

E-print Network

When FPGAs are better at floating-point than microprocessors Florent de Dinechin, J´er´emie Detrey-end microprocessors on floating-point compu- tations thanks to massive parallelism. However, most previous studies re in which the FPGA implementation of a given floating-point compu- tation can be not only faster, but also

Boyer, Edmond

452

MIPS Assembler Exercise "Integer Implementation of Floating-Point Addition"  

E-print Network

CSCE 212 Project 3 MIPS Assembler Exercise "Integer Implementation of Floating-Point Addition" Due Date: 4/15 Abstract Your goal for this project is to implement software emulation of floating point addition for 32-bit (single-precision) floating point numbers. Input/Output Your program will prompt

Bakos, Jason D.

453

Mixed Abstractions for Floating-Point Arithmetic Angelo Brillout  

E-print Network

Mixed Abstractions for Floating-Point Arithmetic Angelo Brillout Computer Systems Institute, ETH Zurich Daniel Kroening and Thomas Wahl Oxford University Computing Laboratory Abstract--Floating. Inaccuracies in floating-point calculations can cause subtle changes of the control flow, potentially leading

Kröning, Daniel

454

Floating-Point Matrix Multiplication in a Polymorphic Processor  

E-print Network

Floating-Point Matrix Multiplication in a Polymorphic Processor Georgi Kuzmanov, Member, IEEE and Wouter M. van Oijen Abstract--We consider 64-bit floating-point matrix multi- plication in the context for large problem sizes. Index Terms--Floating-point arithmetic, Matrix multipli- cation, Polymorphic

Kuzmanov, Georgi

455

1. Introduction Mainstream computers base integer and floating  

E-print Network

1. Introduction Mainstream computers base integer and floating point arithmetic on fixed word for representing as integers input decimal numbers that have been stored in a computer as double precision floating point. The decimal fractions of their floating point representations are all first rounded off

Bernal, Javier

456

Precimonious: Tuning Assistant for Floating-Point Precision  

E-print Network

Precimonious: Tuning Assistant for Floating-Point Precision Cindy Rubio-Gonz´alez1 , Cuong Nguyen1.hough@oracle.com ABSTRACT Given the variety of numerical errors that can occur, floating- point programs are difficult developers in tuning the precision of floating-point programs. Precimonious performs a search on the types

California at Berkeley, University of

457

Floating-point L2 -approximations to functions  

E-print Network

Floating-point L2 -approximations to functions Nicolas Brisebarre Universit´e de Saint by a polynomial with floating-point coefficients; we are looking for the best approximation in the L2 sense pro- jections. However, truncating the coefficients to floating-point numbers, which is needed for fur

California at Davis, University of

458

Exploiting Mixed Precision Floating Point Hardware in Scientific  

E-print Network

Exploiting Mixed Precision Floating Point Hardware in Scientific Computations Alfredo BUTTARI of 32-bit and 64-bit floating point arithmetic, the performance of many dense and sparse linear algebra in using the sin- gle precision, floating point data format over the double precision one. Due to more com

Dongarra, Jack

459

Stochastic Optimization of Floating-Point Programs with Tunable Precision  

E-print Network

Stochastic Optimization of Floating-Point Programs with Tunable Precision Eric Schkufza Stanford Stanford University aiken@cs.stanford.edu Abstract The aggressive optimization of floating-point computations is an important problem in high-performance computing. Unfortunately, floating-point instruction

Aiken, Alex

460

*PBHD: An Efficient Graph Representation for Floating Point Circuit Verification  

E-print Network

*PBHD: An Efficient Graph Representation for Floating Point Circuit Verification Yirng­An Chen Boolean vectors into integer values, but not floating point values. In this paper, we propose a new data for functions that map Boolean vectors into integer or floating point values. The size of the graph to represent

461

Fast Reproducible Floating-Point Summation James Demmel  

E-print Network

Fast Reproducible Floating-Point Summation James Demmel Mathematics Department and CS Division--Reproducibility, i.e. getting the bitwise identical floating point results from multiple runs of the same program, the combination of dynamic scheduling of parallel computing resources, and floating point nonassociativity, make

California at Berkeley, University of

462

Performance Boundaries of Massive Floating Car Data Offloading  

E-print Network

Performance Boundaries of Massive Floating Car Data Offloading Silvia Ancona, Razvan Stanica, Marco Bari, Via Edoardo Orabona 4, 70126 Bari, Italy s.ancona@studenti.poliba.it Abstract--Floating Car Data nearly optimal performance under any FCD aggregation model. I. INTRODUCTION The term Floating Car Data

Fiore, Marco

463

Floating-Point Computation with Just Enough Accuracy  

E-print Network

Floating-Point Computation with Just Enough Accuracy Hank Dietz, Bill Dieter, Randy Fisher with finite precision and range. Using floating-point values as real numbers does not clearly identify support for low-precision floating-point arithmetic common in Digital Signal Processors (DSPs), SIMD

Dietz, Henry G. "Hank"

464

Floating Point Architecture Extensions for Optimized Matrix Factorization  

E-print Network

Floating Point Architecture Extensions for Optimized Matrix Factorization Ardavan Pedram, Andreas of redesigning floating point units and their surrounding data- paths to support these complicated operations. We even in the complex inner kernels of these operations. I. INTRODUCTION Modern computers use floating

Gerstlauer, Andreas

465

L9: Project Discussion and Floating Point Issues  

E-print Network

2/13/12 1 L9: Project Discussion and Floating Point Issues CS6235 Outline · Discussion of semester projects · Floating point ­ Mostly single precision until recent architectures ­ Accuracy ­ What/textbook/Chapter6- FloatingPoint.pdf NVIDA CUDA Programmer's Guide, Appendix C CS6235 2" L9: Projects

Hall, Mary W.

466

Developing Tools for Floating-point Debugging Grey Ballard  

E-print Network

Developing Tools for Floating-point Debugging Grey Ballard CS 263 Design and Analysis of Programming Languages May 4, 2010 1 Introduction Floating-point arithmetic exhibits subtle behavior for experts, locating the source of floating-point exceptions and numerical instabilities in real world

California at Berkeley, University of

467

Parameterized floating-point logarithm and exponential functions for FPGAs  

E-print Network

Parameterized floating-point logarithm and exponential functions for FPGAs J´er´emie Detrey Florent Abstract As FPGAs are increasingly being used for floating-point computing, the feasi- bility of a library of floating-point elementary functions for FPGAs is discussed. An initial implementation of such a library

Detrey, Jérémie

468

REGULAR PAPER Mitochondrial electron transport protects floating leaves of long  

E-print Network

REGULAR PAPER Mitochondrial electron transport protects floating leaves of long leaf pondweed carried to unravel mecha- nism(s) for higher tolerance of floating over submerged leaves of long leaf pondweed (Potamogeton nodosus Poir) against photoinhibition. Chloroplasts from floating leaves showed *5

Govindjee

469

Robust Adaptive Floating-Point Geometric Predicates Jonathan Richard Shewchuk  

E-print Network

Robust Adaptive Floating-Point Geometric Predicates Jonathan Richard Shewchuk School of Computer- able. Their inputs are ordinary single or double precision floating-point numbers. They owe their speed of the result, and is usually small. These algorithms work on computers whose floating-point arithmetic uses

California at Berkeley, University of

470

L9: Next Assignment, Project and Floating Point  

E-print Network

2/22/10 1 L9: Next Assignment, Project and Floating Point Issues CS6963 Administrative Issues · Triangular solve assignment · Project ­ Ideas on how to approach ­ Construct list of questions · Floating, http://courses.ece.illinois.edu/ece498/al/textbook/Chapter6- FloatingPoint.pdf NVIDA CUDA Programmer

Hall, Mary W.

471

Computing Correctly Rounded Integer Powers in Floating-Point Arithmetic  

E-print Network

Computing Correctly Rounded Integer Powers in Floating-Point Arithmetic PETER KORNERUP SDU, Odense integer in floating- point arithmetic, assuming a fused multiply-add (fma) instruction is available-to- nearest mode, that is, our algorithms return the floating-point number that is nearest the exact value

Kornerup, Peter

472

Deciding Floating-Point Logic with Systematic Abstraction  

E-print Network

Deciding Floating-Point Logic with Systematic Abstraction Leopold Haller, Alberto Griggio, Martin for the theory of binary floating-point arithmetic. The core of our ap- proach is a non-trivial generalisation solvers for floating-point arithmetic employ bit-vector encodings. Propositional solvers based

Oxford, University of

473

Robust Adaptive FloatingPoint Geometric Predicates Jonathan Richard Shewchuk  

E-print Network

Robust Adaptive Floating­Point Geometric Predicates Jonathan Richard Shewchuk School of Computer­ able. Their inputs are ordinary single or double precision floating­point numbers. They owe their speed of the result, and is usually small. These algorithms work on computers whose floating­point arithmetic uses

California at Berkeley, University of

474

Computing Correctly Rounded Integer Powers in Floating-Point Arithmetic  

E-print Network

Computing Correctly Rounded Integer Powers in Floating-Point Arithmetic Peter Kornerup Christoph algorithms for accurately evaluating powers to a positive in- teger in floating-point arithmetic, assuming in round-to-nearest mode, that is, our algorithms return the floating-point number that is nearest

Boyer, Edmond

475

RETROSPECTIVE: How to Read Floating Point Numbers Accurately  

E-print Network

RETROSPECTIVE: How to Read Floating Point Numbers Accurately William D Clinger College of Computer scientific notation into binary floating point is nontrivial, but this conversion can be performed to calculate using numbers that are expressed in IEEE- standard binary floating-point notation. Although every

Clinger, William D.

476

Confluent Let-Floating Clemens Grabmayer and Jan Rochel  

E-print Network

Confluent Let-Floating Clemens Grabmayer and Jan Rochel Dept. of Philosophy Dept. of Information­Jones, 1980ies) lambda-lifting = parameter addition + let-floating #12;Motivation letrec as an abstraction­Jones, 1980ies) lambda-lifting = parameter addition + let-floating 2 optimizations of supercombinator transl

Hirokawa, Nao

477

DOMAIN-SPECIFIC HYBRID FPGA: ARCHITECTURE AND FLOATING POINT APPLICATIONS  

E-print Network

DOMAIN-SPECIFIC HYBRID FPGA: ARCHITECTURE AND FLOATING POINT APPLICATIONS Chun Hok Ho1 , Chi Wai Yu and the archi- tecture modelling are addressed. Examples of the proposed architecture for speeding up floating- ditional FPGA devices on selected floating point benchmark circuits. 1. INTRODUCTION FPGA technology has

Luk, Wayne

478

L9: Next Assignment, Project and Floating Point  

E-print Network

L9: Next Assignment, Project and Floating Point Issues CS6963 #12;Administrative Issues · CLASS · Triangular solve assignment · Project ­ Ideas on how to approach ­ Construct list of questions · Floating, http://courses.ece.illinois.edu/ece498/al/textbook/Chapter6- FloatingPoint.pdf NVIDA CUDA Programmer

Hall, Mary W.

479

External Resource: Why Do Astronauts Float in Space?  

NSDL National Science Digital Library

This NASA video segment explains why objects seem to float in space. Viewers learn that an apple that floats in space is really in a state of freefall. Since the whole space shuttle is also in freefall, the apple seems to float. An animation of a person i

1900-01-01

480

University of Cincinnati 2012 Homecoming Parade Float Rules  

E-print Network

of the float (tissue paper, paint, etc.) shall meet the "Field Test" Match Flame Test. These are described in the #12;National Fire Protection Association (NFPA) standard #701 entitled "Fire Tests for Flame Resistant open flame shall not be permitted on or near any float. Displays on floats shall not use any fireworks

Papautsky, Ian

481

Department of Mechanical Engineering Spring 2010 Balanced Floating Labyrinth Seal  

E-print Network

PENNSTATE Department of Mechanical Engineering Spring 2010 Balanced Floating Labyrinth Seal Overview Dresser-Rand presented the team with the challenge of designing a balanced floating labyrinth seal The objective was to provide concrete evidence that a floating labyrinth seal is feasible, and to create

Demirel, Melik C.

482

Comparison between binary and decimal floating-point numbers  

E-print Network

1 Comparison between binary and decimal floating-point numbers Nicolas Brisebarre, Christoph Lauter floating-point (FP) number and a decimal FP number, assuming the "binary encoding" of the decimal formats The IEEE 754-2008 Standard for Floating-Point Arith- metic [5] specifies binary (radix-2) and decimal

483

Calcium dependence of the activation and inactivation kinetics of the light-activated phosphodiesterase of retinal rods  

PubMed Central

The Ca2+ dependence of the kinetics and light sensitivity of light- activated phosphodiesterase was studied with a pH assay in toad and bovine rod disk membranes (RDM), and in a reconstituted system containing GTP-binding protein, phosphodiesterase and rhodopsin kinase. Three statistics, peak hydrolytic velocity, turnoff time, and time to peak velocity, were measured. ATP decreased phosphodiesterase light sensitivity nearly 10-fold and accelerated the dim-flash kinetics of cGMP hydrolysis when compared to those with GTP alone. CA2+ reversed all of the effects of ATP, Ca2+ increased peak velocity, turnoff time, and time to peak velocity, to the values obtained with GTP alone. The Ca2+ dependence of peak velocity and turnoff time can be characterized as hyperbolic saturation functions with a K0.5 for Ca2+ of 1.0-1.5 mM in toad RDM. In bovine RDM the Ca2+ dependence of peak velocity and turnoff time has a K0.5 of 0.1 mM Ca2+. The Ca2+ dependence in the reconstituted system is similar to that in bovine RDM for peak velocity (K0.5 = 0.1 mM Ca2+) but differs for turnoff time (K0.5 = 2.5 mM Ca2+). We tested the hypothesis that a soluble modulator, normally required to confer submicromolar Ca2+ sensitivity, was too dilute in our assay by comparing data obtained at one RDM concentration with those obtained at 10-fold higher RDM, and therefore a constituent protein, concentration. We observe no difference and present a formal analysis of these data that excludes the hypothesis that the soluble modulator binds its target protein with Kd less than 5 microM. The lack of submicromolar Ca2+ dependence of any of the steps in the cGMP cascade that underlie cGMP phosphodiesterase activation and inactivation in vitro argues against Ca2+ regulation of these steps having a significant role in the light adaptation of the intact rod. PMID:2549175

1989-01-01

484

Photoluminescent properties of Pr3+ activated Y2WO6 for light emitting diodes  

NASA Astrophysics Data System (ADS)

A series of Pr3+ activated Y2WO6 phosphors are prepared by solid state reaction method. The crystalline phase and luminescent properties of samples are discussed by X-ray diffraction spectra and photoluminescence spectra, respectively. The photoluminescence excitation spectrum indicates that the sample can absorb both UV and blue light. And the samples emit a blue emission of WO66- and the characteristic red emission of Pr3+. The partial quenching of the other prominent blue luminescence from 3P0 state is ascribed to a radiationless relaxation pathway involving a low-lying Pr4+-W5+ intervalence charge transfer (IVCT) state. Through adjusting the excitation wavelength, Y2WO6: Pr3+ can not only emit warm white light with CIE coordinates of (0.33, 0.37) but also show bright red emission with CIE coordinates of (0.66, 0.33). In addition, the thermal properties of the samples are also investigated in detail. The results show that the application as a white and red component for white light emitting diodes is proposed.

Wang, Qian; Zhu, Ge; Li, Yanyan; Wang, Yuhua

2015-04-01

485

Light activation of genotoxic components in natural and synthetic crude oils  

SciTech Connect

Undefined components in natural and synthetically-produced petroleums elicit a genotoxic response in cultured mammalian cells after exposure to light. The NUV component of the solar spectrum is the radiation responsible for photochemical transformation. The type(s) of lesion(s) induced in DNA by the photoactivation process is mimetic of FUV light-induced genotoxic lesions (bulky adduct-like) due to the similar sensitizing abilities of either insult in cells deficient in excision repair. Because of their intimate contact with the oil in the various stages associated with the production of shale oil, process waters contain significant quantities of uv-absorbing organic materials. Chemical fractionation of a process water has been achieved using an acid/base extraction scheme and reverse-phase HPLC. Resulting fractions have been assessed for photo-induced genotoxicity using a modification of the Ames/Salmonella bioassay in which NUV light is the source of activation in place of metabolic enzymes. Chemical identification of components in a photoactive peak fraction is in progress employing an additional class fractionation scheme and GC/MS methods.

Strniste, G.

1982-01-01