WorldWideScience

Sample records for optimal light microhabitats

  1. Maintaining mimicry diversity: optimal warning colour patterns differ among microhabitats in Amazonian clearwing butterflies.

    Science.gov (United States)

    Willmott, Keith R; Robinson Willmott, Julia C; Elias, Marianne; Jiggins, Chris D

    2017-05-31

    Mimicry is one of the best-studied examples of adaptation, and recent studies have provided new insights into the role of mimicry in speciation and diversification. Classical Müllerian mimicry theory predicts convergence in warning signal among protected species, yet tropical butterflies are exuberantly diverse in warning colour patterns, even within communities. We tested the hypothesis that microhabitat partitioning in aposematic butterflies and insectivorous birds can lead to selection for different colour patterns in different microhabitats and thus help maintain mimicry diversity. We measured distribution across flight height and topography for 64 species of clearwing butterflies (Ithomiini) and their co-mimics, and 127 species of insectivorous birds, in an Amazon rainforest community. For the majority of bird species, estimated encounter rates were non-random for the two most abundant mimicry rings. Furthermore, most butterfly species in these two mimicry rings displayed the warning colour pattern predicted to be optimal for anti-predator defence in their preferred microhabitats. These conclusions were supported by a field trial using butterfly specimens, which showed significantly different predation rates on colour patterns in two microhabitats. We therefore provide the first direct evidence to support the hypothesis that different mimicry patterns can represent stable, community-level adaptations to differing biotic environments. © 2017 The Author(s).

  2. Office lighting systems: Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Dagnino, U. (ENEL, Milan (Italy))

    1990-09-01

    Relative to office lighting systems, in particular, those making use of tubular fluorescent lamps, currently available on the international market, this paper tries to develop lighting system, design optimization criteria. The comparative assessment of the various design possibilities considers operating cost, energy consumption, and occupational comfort/safety aspects such as lighting level uniformity and equilibrium, reduction of glare and reflection, natural/artificial lighting balance, programmed switching, computerized control systems for multi-use requirements in large areas, programmed maintenance for greater efficiency and reliability.

  3. Optimizing Light for Long Duration Space Exploration

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of our work is to optimize lighting that supports vision and serves as a circadian countermeasure for astronauts and ground crew during space missions. Due...

  4. Fuzzy Multiobjective Traffic Light Signal Optimization

    Directory of Open Access Journals (Sweden)

    N. Shahsavari Pour

    2013-01-01

    Full Text Available Traffic congestion is a major concern for many cities throughout the world. In a general traffic light controller, the traffic lights change at a constant cycle time. Hence it does not provide an optimal solution. Many traffic light controllers in current use are based on the “time-of-the-day” scheme, which use a limited number of predetermined traffic light patterns and implement these patterns depending upon the time of the day. These automated systems do not provide an optimal control for fluctuating traffic volumes. In this paper, the fuzzy traffic light controller is used to optimize the control of fluctuating traffic volumes such as oversaturated or unusual load conditions. The problem is solved by genetic algorithm, and a new defuzzification method is introduced. The performance of the new defuzzification method (NDM is compared with the centroid point defuzzification method (CPDM by using ANOVA. Finally, an illustrative example is presented to show the competency of proposed algorithm.

  5. Particle Swarm Optimization for Outdoor Lighting Design

    Directory of Open Access Journals (Sweden)

    Ana Castillo-Martinez

    2017-01-01

    Full Text Available Outdoor lighting is an essential service for modern life. However, the high influence of this type of facility on energy consumption makes it necessary to take extra care in the design phase. Therefore, this manuscript describes an algorithm to help light designers to get, in an easy way, the best configuration parameters and to improve energy efficiency, while ensuring a minimum level of overall uniformity. To make this possible, we used a particle swarm optimization (PSO algorithm. These algorithms are well established, and are simple and effective to solve optimization problems. To take into account the most influential parameters on lighting and energy efficiency, 500 simulations were performed using DIALux software (4.10.0.2, DIAL, Ludenscheid, Germany. Next, the relation between these parameters was studied using to data mining software. Subsequently, we conducted two experiments for setting parameters that enabled the best configuration algorithm in order to improve efficiency in the proposed process optimization.

  6. Optimization of light quality from color mixing light-emitting diode systems for general lighting

    Science.gov (United States)

    Thorseth, Anders

    2012-03-01

    Given the problem of metamerisms inherent in color mixing in light-emitting diode (LED) systems with more than three distinct colors, a method for optimizing the spectral output of multicolor LED system with regards to standardized light quality parameters has been developed. The composite spectral power distribution from the LEDs are simulated using spectral radiometric measurements of single commercially available LEDs for varying input power, to account for the efficiency droop and other non-linear effects in electrical power vs. light output. The method uses electrical input powers as input parameters in a randomized steepest decent optimization. The resulting spectral power distributions are evaluated with regard to the light quality using the standard characteristics: CIE color rendering index, correlated color temperature and chromaticity distance. The results indicate Pareto optimal boundaries for each system, mapping the capabilities of the simulated lighting systems with regard to the light quality characteristics.

  7. Endoscopic hyperspectral imaging: light guide optimization for spectral light source

    Science.gov (United States)

    Browning, Craig M.; Mayes, Samuel; Rich, Thomas C.; Leavesley, Silas J.

    2018-02-01

    Hyperspectral imaging (HSI) is a technology used in remote sensing, food processing and documentation recovery. Recently, this approach has been applied in the medical field to spectrally interrogate regions of interest within respective substrates. In spectral imaging, a two (spatial) dimensional image is collected, at many different (spectral) wavelengths, to sample spectral signatures from different regions and/or components within a sample. Here, we report on the use of hyperspectral imaging for endoscopic applications. Colorectal cancer is the 3rd leading cancer for incidences and deaths in the US. One factor of severity is the miss rate of precancerous/flat lesions ( 65% accuracy). Integrating HSI into colonoscopy procedures could minimize misdiagnosis and unnecessary resections. We have previously reported a working prototype light source with 16 high-powered light emitting diodes (LEDs) capable of high speed cycling and imaging. In recent testing, we have found our current prototype is limited by transmission loss ( 99%) through the multi-furcated solid light guide (lightpipe) and the desired framerate (20-30 fps) could not be achieved. Here, we report on a series of experimental and modeling studies to better optimize the lightpipe and the spectral endoscopy system as a whole. The lightpipe was experimentally evaluated using an integrating sphere and spectrometer (Ocean Optics). Modeling the lightpipe was performed using Monte Carlo optical ray tracing in TracePro (Lambda Research Corp.). Results of these optimization studies will aid in manufacturing a revised prototype with the newly designed light guide and increased sensitivity. Once the desired optical output (5-10 mW) is achieved then the HIS endoscope system will be able to be implemented without adding onto the procedure time.

  8. Optimization of light quality from color mixing light-emitting diode systems for general lighting

    DEFF Research Database (Denmark)

    Thorseth, Anders

    2012-01-01

    are simulated using radiometrically measured single LED spectra. The method uses electrical input powers as input parameters and optimizes the resulting spectral power distribution with regard to color rendering index, correlated color temperature and chromaticity distance. The results indicate Pareto optimal......To address the problem of spectral light quality from color mixing light-emitting diode systems, a method for optimizing the spectral output of multicolor LED system with regards to standardized quality parameters has been developed. The composite spectral power distribution from the LEDs...

  9. Influence of microhabitat temperature on Coelaenomenodera ...

    African Journals Online (AJOL)

    This study examined the direct effects of microhabitat temperature on a major pest of the oil palm, Coelaenomenodera elaeidis, its parasitoids and predatory ants. Field plots for observations of microhabitat temperature were established to run through January 2009 to December 2010 at the main station of the Nigerian ...

  10. Light Focusing through Scattering Media by Particle Swarm Optimization

    International Nuclear Information System (INIS)

    Huang Hui-Ling; Chen Zi-Yang; Sun Cun-Zhi; Liu Ji-Lin; Pu Ji-Xiong

    2015-01-01

    We demonstrate light focusing through scattering media by introducing particle swarm optimization for modulating the phase wavefront. Light refocusing is simulated numerically based on the angular spectrum method and the circular Gaussian distribution model of the scattering media. Experimentally, a spatial light modulator is used to control the phase of incident light, so as to make the scattered light converge to a focus. The influence of divided segments of input light and the effect of the number of iterations on light intensity enhancement are investigated. Simulation results are found to be in good agreement with the theoretical analysis for light refocusing. (paper)

  11. Optimization of freeform lightpipes for light-emitting-diode projectors.

    Science.gov (United States)

    Fournier, Florian; Rolland, Jannick

    2008-03-01

    Standard nonimaging components used to collect and integrate light in light-emitting-diode-based projector light engines such as tapered rods and compound parabolic concentrators are compared to optimized freeform shapes in terms of transmission efficiency and spatial uniformity. We show that the simultaneous optimization of the output surface and the profile shape yields transmission efficiency within the étendue limit up to 90% and spatial uniformity higher than 95%, even for compact sizes. The optimization process involves a manual study of the trends for different shapes and the use of an optimization algorithm to further improve the performance of the freeform lightpipe.

  12. Characterization, Modeling, and Optimization of Light-Emitting Diode System

    DEFF Research Database (Denmark)

    Thorseth, Anders

    limit of human color perception. A method has been developed to optimize multicolored cluster LED systems with respect to light quality, using multi objective optimization. The results are simulated SPDs similar to traditional light sources, and with high light quality. As part of this work...... the techniques have been applied in practical illumination applications. The presented examples are historical artifacts and illumination of plants to increase photosynthesis....

  13. Focusing light through dynamical samples using fast continuous wavefront optimization.

    Science.gov (United States)

    Blochet, B; Bourdieu, L; Gigan, S

    2017-12-01

    We describe a fast continuous optimization wavefront shaping system able to focus light through dynamic scattering media. A micro-electro-mechanical system-based spatial light modulator, a fast photodetector, and field programmable gate array electronics are combined to implement a continuous optimization of a wavefront with a single-mode optimization rate of 4.1 kHz. The system performances are demonstrated by focusing light through colloidal solutions of TiO 2 particles in glycerol with tunable temporal stability.

  14. Energy Optimization of Road Tunnel Lighting Systems

    Directory of Open Access Journals (Sweden)

    Ferdinando Salata

    2015-07-01

    Full Text Available A road tunnel is an enclosed and covered infrastructure for the vehicular traffic. Its lighting system provides 24 h of artificial sources only, with a higher amount of electric power used during the day. Due to safety reasons, when there is natural lighting outside the tunnel, the lighting levels in the stretches right after the entrance and before the exit must be high, in order to guide the driver’s eye towards the middle of the tunnel where the luminance must guarantee safe driving, avoid any over-dimensioning of the lighting systems, and produce energy savings. Such effects can be reached not only through the technological advances in the field of artificial lighting sources with high luminous efficiency, but also through new materials for road paving characterized by a higher reflection coefficient than other ordinary asphalts. This case study examines different technical scenarios, analyzing and comparing possible energy and economic savings. Traditional solutions are thus compared with scenarios suggesting the solutions previously mentioned. Special asphalts are interesting from an economic point of view, whereas the high costs of LED sources nowadays represent an obstacle for their implementation.

  15. Microhabitat influence on larval fish assemblages within ...

    Science.gov (United States)

    We examined larval and juvenile fish assemblage structure in relation to microhabitat variables within the St. Louis River estuary, a drowned river mouth of Lake Superior. Fish were sampled in vegetated beds throughout the estuary, across a gradient of vegetation types and densities (including disturbed, preserved and post-restoration sites). Canonical correspondence analysis, relating species abundances to environmental variables revealed that plant species richness, turbidity and aquatic plant cover were most influential in structuring assemblages. Results from this microhabitat analysis at this crucial life stage has potential to inform wetland restoration efforts within the St. Louis River and other Great Lake coastal wetlands. not applicable

  16. Light distribution in diffractive multifocal optics and its optimization.

    Science.gov (United States)

    Portney, Valdemar

    2011-11-01

    To expand a geometrical model of diffraction efficiency and its interpretation to the multifocal optic and to introduce formulas for analysis of far and near light distribution and their application to multifocal intraocular lenses (IOLs) and to diffraction efficiency optimization. Medical device consulting firm, Newport Coast, California, USA. Experimental study. Application of a geometrical model to the kinoform (single focus diffractive optical element) was expanded to a multifocal optic to produce analytical definitions of light split between far and near images and light loss to other diffraction orders. The geometrical model gave a simple interpretation of light split in a diffractive multifocal IOL. An analytical definition of light split between far, near, and light loss was introduced as curve fitting formulas. Several examples of application to common multifocal diffractive IOLs were developed; for example, to light-split change with wavelength. The analytical definition of diffraction efficiency may assist in optimization of multifocal diffractive optics that minimize light loss. Formulas for analysis of light split between different foci of multifocal diffractive IOLs are useful in interpreting diffraction efficiency dependence on physical characteristics, such as blaze heights of the diffractive grooves and wavelength of light, as well as for optimizing multifocal diffractive optics. Disclosure is found in the footnotes. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  17. Optimal Fisher Discriminant Ratio for an Arbitrary Spatial Light Modulator

    Science.gov (United States)

    Juday, Richard D.

    1999-01-01

    Optimizing the Fisher ratio is well established in statistical pattern recognition as a means of discriminating between classes. I show how to optimize that ratio for optical correlation intensity by choice of filter on an arbitrary spatial light modulator (SLM). I include the case of additive noise of known power spectral density.

  18. Characterization, Modeling, and Optimization of Light-Emitting Diode Systems

    DEFF Research Database (Denmark)

    Thorseth, Anders

    are simulated SPDs similar to traditional light sources, and with high light quality. As part of this work the techniques have been applied in practical illumination applications. The presented examples are historical artifacts and illumination of plants to increase photosynthesis....... comparing the chromaticity of the measured SPD with tted models, the deviation is found to be larger than the lower limit of human color perception. A method has been developed to optimize multicolored cluster LED systems with respect to light quality, using multi objective optimization. The results...

  19. Microhabitat analysis using radiotelemetry locations and polytomous logistic regression

    Science.gov (United States)

    Malcolm P. North; Joel H. Reynolds

    1996-01-01

    Microhabitat analyses often use discriminant function analysis (DFA) to compare vegetation structures or environmental conditions between sites classified by a study animal's presence or absence. These presence/absence studies make questionable assumptions about the habitat value of the comparison sites and the microhabitat data often violate the DFA's...

  20. Variation in selection of microhabitats by Merriam's turkey brood hens

    Science.gov (United States)

    Mark A. Rumble; Stanley H. Anderson

    1997-01-01

    We studied microhabitats of Merriam‘s turkey (Meleagris gallopavo merriami) brood hens in a ponderosa pine (Pinus ponderosa) ecosystem in South Dakota from 1986 to 1988. Cluster analysis indicated three groups of microhabitats, open-shrub, open-grasslforb and forest, based on vegetation characteristics at sites selected by brood...

  1. The Optimal Wavelengths for Light Absorption Spectroscopy Measurements Based on Genetic Algorithm-Particle Swarm Optimization

    Science.gov (United States)

    Tang, Ge; Wei, Biao; Wu, Decao; Feng, Peng; Liu, Juan; Tang, Yuan; Xiong, Shuangfei; Zhang, Zheng

    2018-03-01

    To select the optimal wavelengths in the light extinction spectroscopy measurement, genetic algorithm-particle swarm optimization (GAPSO) based on genetic algorithm (GA) and particle swarm optimization (PSO) is adopted. The change of the optimal wavelength positions in different feature size parameters and distribution parameters is evaluated. Moreover, the Monte Carlo method based on random probability is used to identify the number of optimal wavelengths, and good inversion effects of the particle size distribution are obtained. The method proved to have the advantage of resisting noise. In order to verify the feasibility of the algorithm, spectra with bands ranging from 200 to 1000 nm are computed. Based on this, the measured data of standard particles are used to verify the algorithm.

  2. Optimal linear precoding for indoor visible light communication system

    KAUST Repository

    Sifaou, Houssem

    2017-07-31

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

  3. The micro-habitat methodology. Application protocols

    Energy Technology Data Exchange (ETDEWEB)

    Sabaton, C; Valentin, S; Souchon, Y

    1995-06-01

    A strong need has been felt for guidelines to help various entities in applying the micro-habitat methodology, particularly in impact studies on hydroelectric installations. CEMAGREF and Electricite de France have developed separately two protocols with five major steps: reconnaissance of the river, selection of representative units to be studied in greater depth, morpho-dynamic measurements at one or more rates of discharge and hydraulic modeling, coupling of hydraulic and biological models, calculation of habitat-quality scores for fish, analysis of results. The two approaches give very comparable results and are essentially differentiated by the hydraulic model used. CEMAGREF uses a one-dimensional model requiring measurements at only one discharge rate. Electricite de France uses a simplified model based on measurements at several rates of discharge. This approach is possible when discharge can be controlled in the study area during data acquisition, as is generally the case downstream of hydroelectric installations. The micro-habitat methodology is now a fully operational tool with which to study changes in fish habitat quality in relation to varying discharge. It provides an element of assessment pertinent to the choice of instreaming flow to be maintained downstream of a hydroelectric installation; this information is essential when the flow characteristics (velocity, depth) and the nature of the river bed are the preponderant factors governing habitat suitability for trout or salmon. The ultimate decision must nonetheless take into account any other potentially limiting factors for the biocenoses on the one hand, and the target water use objectives on the other. In many cases, compromises must be found among different uses, different species and different stages in the fish development cycle. (Abstract Truncated)

  4. Fall and winter microhabitat use and suitability for spring chinook salmon parr in a U.S. Pacific Northwest River

    Science.gov (United States)

    Favrot, Scott D.; Jonasson, Brian C.; Peterson, James T.

    2018-01-01

    Habitat degradation has been implicated as a primary threat to Pacific salmon Oncorhynchus spp. Habitat restoration and conservation are key toward stemming population declines; however, winter microhabitat use and suitability knowledge are lacking for small juvenile salmonids. Our objective was to characterize microhabitat use and suitability for spring Chinook Salmon Oncorhynchus tshawytscha parr during fall and winter. Using radiotelemetry techniques during October–February (2009–2011), we identified fall and winter microhabitat use by spring Chinook Salmon parr in Catherine Creek, northeastern Oregon. Tagged fish occupied two distinct gradient reaches (moderate and low). Using a mixed‐effects logistic regression resource selection function (RSF) model, we found evidence that microhabitat use was similar between free‐flowing and surface ice conditions. However, habitat use shifted between seasons; most notably, there was greater use of silt substrate and areas farther from the bank during winter. Between gradients, microhabitat use differed with greater use of large wood (LW) and submerged aquatic vegetation in the low‐gradient reach. Using a Bayesian RSF approach, we developed gradient‐specific habitat suitability criteria. Throughout the study area, deep depths and slow currents were most suitable, with the exception of the low‐gradient reach where moderate depths were optimal. Near‐cover coarse and fine substrates were most suitable in the moderate‐ and low‐gradient reaches, respectively. Near‐bank LW was most suitable throughout the study area. Multivariate principal component analyses (PCA) indicated co‐occurring deep depths supporting slow currents near cover were intensively occupied in the moderate‐gradient reach. In the low‐gradient reach, PCA indicated co‐occurring moderate depths, slow currents, and near‐bank cover were most frequently occupied. Our study identified suitable and interrelated microhabitat

  5. MODELING SNAKE MICROHABITAT FROM RADIOTELEMETRY STUDIES USING POLYTOMOUS LOGISTIC REGRESSION

    Science.gov (United States)

    Multivariate analysis of snake microhabitat has historically used techniques that were derived under assumptions of normality and common covariance structure (e.g., discriminant function analysis, MANOVA). In this study, polytomous logistic regression (PLR which does not require ...

  6. Efficiency optimization of green phosphorescent organic light-emitting device

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jung Soo; Jeon, Woo Sik; Yu, Jae Hyung [Department of Information Display, Kyung Hee University, Dongdaemoon-gu, Seoul 130-701 (Korea, Republic of); Pode, Ramchandra, E-mail: rbpode@khu.ac.k [Department of Physics, Kyung Hee University, Dongdaemoon-gu, Seoul 130-701 (Korea, Republic of); Kwon, Jang Hyuk, E-mail: jhkwon@khu.ac.k [Department of Information Display, Kyung Hee University, Dongdaemoon-gu, Seoul 130-701 (Korea, Republic of)

    2011-03-01

    Using a narrow band gap host of bis[2-(2-hydroxyphenyl)-pyridine]beryllium (Bepp{sub 2}) and green phosphorescent Ir(ppy){sub 3} [fac-tris(2-phenylpyridine) iridium III] guest concentration as low as 2%, high efficiency phosphorescent organic light-emitting diode (PHOLED) is realized. Current and power efficiencies of 62.5 cd/A (max.), 51.0 lm/W (max.), and external quantum efficiency (max.) of 19.8% are reported in this green PHOLED. A low current efficiency roll-off value of 10% over the brightness of 10,000 cd/m{sup 2} is noticed in this Bepp{sub 2} single host device. Such a high efficiency is obtained by the optimization of the doping concentration with the knowledge of the hole trapping and the emission zone situations in this host-guest system. It is suggested that the reported device performance is suitable for applications in high brightness displays and lighting.

  7. Integrated optimization of temperature, CO2, screen use and artificial lighting in greenhouse crops

    DEFF Research Database (Denmark)

    Aaslyng, J.M.; Körner, O.; Andreassen, A.U.

    2005-01-01

    A leaf photosynthesis model is suggested for integrated optimization of temperature, CO2, screen use and artificial lighting in greenhouse crops. Three different approaches for the optimization are presented. First, results from greenhouse experiments with model based optimization are presented....... Second, a model-based analysis of a commercial grower's production possibility is shown. Third, results from a simulation of the effect of a new lighting strategy are demonstrated. The results demonstrate that it is possible to optimize plant production by using a model-based integrated optimization...... of temperature, CO2, and light in the greenhouse...

  8. Optimization of the digital Silicon Photomultiplier for Cherenkov light detection

    International Nuclear Information System (INIS)

    Frach, T

    2012-01-01

    The Silicon Photomultiplier is a promising alternative to fast vacuum photodetectors. We developed a fully digital implementation of the Silicon Photomultiplier. The sensor is based on a single photon avalanche photodiode (SPAD) integrated in a standard CMOS process. Photons are detected directly by sensing the voltage at the SPAD anode using a dedicated cell electronics block next to each diode. This block also contains active quenching and recharge circuits as well as a one bit memory for the selective inhibit of detector cells. A balanced trigger network is used to propagate the trigger signal from all cells to the integrated time-to-digital converter. Photons are detected and counted as digital signals, thus making the sensor less susceptible to temperature variations and electronic noise. The integration with CMOS logic has the added benefit of low power consumption and possible integration of data post-processing in the sensor. In this paper, we discuss the sensor architecture together with its characteristics, and its possible optimizations for applications requiring the detection of Cherenkov light.

  9. Effects of microhabitat on leaf traits in Digitalis grandiflora L. (Veronicaceae growing at forest edge and interior

    Directory of Open Access Journals (Sweden)

    Kołodziejek J.

    2014-01-01

    Full Text Available The morphological, anatomical and biochemical traits of the leaves of yellow foxglove (Digitalis grandiflora Mill. from two microhabitats, forest interior (full shade under oak canopy and forest edge (half shade near shrubs, were studied. The microhabitats differed in the mean levels of available light, but did not differ in soil moisture. The mean level of light in the forest edge microhabitat was significantly higher than in the forest interior. Multivariate ANOVA was used to test the effects of microhabitat. Comparison of the available light with soil moisture revealed that both factors significantly influenced the morphological and anatomical variables of D. grandiflora. Leaf area, mass, leaf mass per area (LMA, surface area per unit dry mass (SLA, density and thickness varied greatly between leaves exposed to different light regimes. Leaves that developed in the shade were larger and thinner and had a greater SLA than those that developed in the half shade. In contrast, at higher light irradiances, at the forest edge, leaves tended to be thicker, with higher LMA and density. Stomatal density was higher in the half-shade leaves than in the full-shade ones. LMA was correlated with leaf area and mass and to a lesser extent with thickness and density in the forest edge microsite. The considerable variations in leaf density and thickness recorded here confirm the very high variation in cell size and amounts of structural tissue within species. The leaf plasticity index (PI was the highest for the morphological leaf traits as compared to the anatomical and biochemical ones. The nitrogen content was higher in the “half-shade leaves” than in the “shade leaves”. Denser leaves corresponded to lower nitrogen (N contents. The leaves of plants from the forest edge had more potassium (K than leaves of plants from the forest interior on an area basis but not on a dry mass basis; the reverse was true for phosphorus.

  10. Optimizing design parameter for light isotopes separation by distillation method

    International Nuclear Information System (INIS)

    Ahmadi, M.

    1999-01-01

    More than methods are suggested in the world for producing heavy water, where between them chemical isotopic methods, distillation and electro lys are used widely in industrial scale. To select suitable method for heavy water production in Iran, taking into consideration, domestic technology an facilities, combination of hydrogen sulphide-water dual temperature process (Gs) and distillation (D W) may be proposed. Natural water, is firstly enriched up to 15 a% by G S process and then by distillation unit is enriched up to the grade necessary for Candu type reactors (99.8 a%). The aim of present thesis, is to achieve know-how, optimization of design parameters, and executing basic design for water isotopes separation using distillation process in a plant having minimum scale possible. In distillation, vapour phase resulted from liquid phase heating, is evidently composed of the same constituents as liquid phase. In isotopic distillation, the difference in composition of constituents is not considerable. In fact alteration of constituents composition is so small that makes the separation process impossible, however, direct separation and production of pure products without further processing which becomes possible by distillation, makes this process as one of the most important separation processes. Profiting distillation process to produce heavy water is based on difference existing between boiling point of heavy and light water. The trends of boiling points differences (heavy and light water) is adversely dependant with pressure. As the whole system pressure decreases, difference in boiling points increases. On the other hand according to the definition, separation factor is equal to the ratio of pure light water vapour pressure to that of heavy water, or we can say that the trend of whole system pressure decrease results in separation factor increase, which accordingly separation factor equation to pressure variable should be computed firstly. According to the

  11. Optimizing Lighting Design for Hospital Wards by Defining User Zones

    DEFF Research Database (Denmark)

    Thuesen, Niels; Stidsen, Lone; Kirkegaard, Poul Henning

    2011-01-01

    of lighting design, so it has the ability to support the different users activity and behavior on the ward. By using RFID tracking and manual observations we have analyzed and evaluated the ward functionality as working environment for the staff. The method creates a higher understanding of the ward...... of lighting design in private and public settings are often not similar. The purpose of this article is therefore present a approach dividing the hospital ward in 3 user zones for patients, staff and visitors. The main user of the zone should be in control of the light scenario and thereby a refining...

  12. Photoelectrochemical water splitting: optimizing interfaces and light absorption

    NARCIS (Netherlands)

    Park, Sun-Young

    2015-01-01

    In this thesis several photoelectrochemical water splitting devices based on semiconductor materials were investigated. The aim was the design, characterization, and fabrication of solar-to-fuel devices which can absorb solar light and split water to produce hydrogen.

  13. Optimization of catalytic glycerol steam reforming to light olefins using Cu/ZSM-5 catalyst

    International Nuclear Information System (INIS)

    Zakaria, Z.Y.; Amin, N.A.S.; Linnekoski, J.

    2014-01-01

    Highlights: • Glycerol steam reforming to light olefin using Cu/ZSM-5 process was optimized. • Response surface methodology and multi-objective genetic algorithm were employed. • Second order polynomial model produced adequately fitted experimental data. • Thermodynamic study inferred high temperature requirement for ethylene formation. • Turn-over-frequency at optimized responses is higher than the non-optimized process. - Abstract: Response surface methodology (RSM) and multi-objective genetic algorithm was employed to optimize the process parameters for catalytic conversion of glycerol, a byproduct from biodiesel production, to light olefins using Cu/ZSM-5 catalyst. The effects of operating temperature, weight hourly space velocity (WHSV) and glycerol concentration on light olefins selectivity and yield were observed. Experimental results revealed the data adequately fitted into a second-order polynomial model. The linear temperature and quadratic WHSV terms gave significant effect on both responses. Optimization of both the responses indicated that temperature favouring high light olefin formation lied beyond the experimental design range. The trend in the temperature profile concurred commensurately with the thermodynamic analysis. Multi-objective genetic algorithm was performed to attain a single set of processing parameters that could produce both the highest light olefin selectivity and yield. The turn-over-frequency (TOF) of the optimized responses demonstrated a slightly higher value than the one which was not optimized. Combination of RSM, multi-objective response and thermodynamic is useful to determine the process optimal operating conditions for industrial applications

  14. Larval microhabitats of Lutzomyia longipalpis (Diptera: Psychodidae) in an endemic focus of visceral leishmaniasis in Colombia.

    Science.gov (United States)

    Ferro, C; Pardo, R; Torres, M; Morrison, A C

    1997-11-01

    An intensive search for the larval habitats of Lutzomyia longipalpis (Lutz & Neiva) was conducted from November 1992 to October 1993 at a small rural community in Colombia where American visceral leishmaniasis is endemic. Emergence traps constructed from polyvinyl chloride pipes were used to sample a variety of soil microhabitats that included edge areas of covered pigpens, cattle corrals, the base of trees, and leaf litter at sites within 40 m of a house, rocks in fields located between 50 and 500 m from houses, and sites within a patch of secondary forest (rocks, base of palm trees, and leaf litter). The teneral status of the sand flies captured in the emergence traps was confirmed by laboratory studies that determined the rate of terminalia rotation in male L. longipalpis and the rate of cuticular growth layer formation of the thoracic phragma in both sexes of this species. A total of 58 teneral sand flies was captured during the study period (49 wk). Fifteen specimens were L. longipalpis; of these 11 (5 sand flies per square meter) were captured near pigpens, 3 (1.4 sand flies per square meter) were captured near rock resting sites, and 1 (1.6 sand flies per square meter) was collected at the base of a tree. The remainder of the sand flies were either L. trinidadensis (Newstead) or L. cayennensis (Flock & Abonnenc). Our results indicate that L. longipalpis larvae were dispersed widely in sites near houses, rather than concentrated in a few optimal microhabitats.

  15. Shedding light on endocytosis with optimized super-resolution microscopy

    NARCIS (Netherlands)

    Leyton Puig, D.M.

    2017-01-01

    Super-resolution microscopy is a relatively new microscopy technique that is still under optimization. In this thesis we focus on the improvement of the quality of super-resolution images, to apply them to the study of the processes of cell signaling and endocytosis. First, we show that the use of a

  16. Recycling light metals : Optimal thermal de-coating

    NARCIS (Netherlands)

    Kvithyld, A.; Meskers, C.E.M.; Gaal, S.; Reuter, M.

    2008-01-01

    Thermal de-coating of painted and lacquered scrap is one of the new innovations developed for aluminum recycling. If implemented in all recycling and optimized as suggested in this article, recovery would be improved with considerable economic impact. Generally, contaminated scrap is difficult to

  17. Microhabitat features influencing habitat use by Florida black bears

    Directory of Open Access Journals (Sweden)

    Dana L. Karelus

    2018-01-01

    Full Text Available Understanding fine-scale habitat needs of species and the factors influencing heterogeneous use of habitat within home range would help identify limiting resources and inform habitat management practices. This information is especially important for large mammals living in fragmented habitats where resources may be scarcer and more patchily distributed than in contiguous habitats. Using bihourly Global Position System (GPS location data collected from 10 individuals during 2011–2014, we investigated microhabitat features of areas within home ranges that received high vs. low intensity of use by Florida black bears (Ursus americanus floridanus in north-central, Florida. We identified areas receiving high and low levels of use by bears based on their utilization distributions estimated with the dynamic Brownian bridge movement model, and performed vegetation sampling at bear locations within high- and low-use areas. Using univariate analyses and generalized linear mixed models, we found that (1 canopy cover, visual obstruction, and hardwood density were important in defining high-use sites; (2 the probability of high use was positively associated with principal components that represented habitat closer to creeks and with high canopy and shrub cover and higher hardwood densities, likely characteristic of forested wetlands; and (3 the probability of high use was, to a lesser extent, associated with principal components that represented habitat with high canopy cover, high pine density, and low visual obstruction and hardwood density; likely representing sand pine and pine plantations. Our results indicate that the high bear-use sites were in forested wetlands, where cover and food resources for bears are likely to occur in higher abundance. Habitat management plans whereby bears are a focal species should aim to increase the availability and quality of forested wetlands. Keywords: Habitat selection, Heterogeneous habitat use, Forest management

  18. Integrated Design Optimization of a 5-DOF Assistive Light-weight Anthropomorphic Arm

    DEFF Research Database (Denmark)

    Zhou, Lelai; Bai, Shaoping; Hansen, Michael Rygaard

    2011-01-01

    An integrated dimensional and drive train optimization method was developed for light-weight robotic arm design. The method deals with the determination of optimal link lengths and the optimal selection of motors and gearboxes from commercially available components. Constraints are formulated...... on the basis of kinematic performance and dynamic requirements, whereas the main objective is to minimize the weight. The design of a human-like arm, which is 10 kg in weight with a load capacity of 5 kg, is described....

  19. Modelling of salad plants growth and physiological status in vitamin space greenhouse during lighting regime optimization

    Science.gov (United States)

    Konovalova, Irina; Berkovich, Yuliy A.; Smolyanina, Svetlana; Erokhin, Alexei; Yakovleva, Olga; Lapach, Sergij; Radchenko, Stanislav; Znamenskii, Artem; Tarakanov, Ivan

    2016-07-01

    The efficiency of the photoautotrophic element as part of bio-engineering life-support systems is determined substantially by lighting regime. The artificial light regime optimization complexity results from the wide range of plant physiological functions controlled by light: trophic, informative, biosynthetical, etc. An average photosynthetic photon flux density (PPFD), light spectral composition and pulsed light effects on the crop growth and plant physiological status were studied in the multivariate experiment, including 16 independent experiments in 3 replicates. Chinese cabbage plants (Brassica chinensis L.), cultivar Vesnianka, were grown during 24 days in a climatic chamber under white and red light-emitting diodes (LEDs): photoperiod 24 h, PPFD from 260 to 500 µM/(m ^{2}*s), red light share in the spectrum varying from 33% to 73%, pulsed (pulse period from 30 to 501 µs) and non-pulsed lighting. The regressions of plant photosynthetic and biochemical indexes as well as the crop specific productivity in response to the selected parameters of lighting regime were calculated. Developed models of crop net photosynthesis and dark respiration revealed the most intense gas exchange area corresponding to PPFD level 450 - 500 µM/(m ^{2}*s) with red light share in the spectrum about 60% and the pulse length 30 µs with a pulse period from 300 to 400 µs. Shoot dry weight increased monotonically in response to the increasing PPFD and changed depending on the pulse period under stabilized PPFD level. An increase in ascorbic acid content in the shoot biomass was revealed when increasing red light share in spectrum from 33% to 73%. The lighting regime optimization criterion (Q) was designed for the vitamin space greenhouse as the maximum of a crop yield square on its ascorbic acid concentration, divided by the light energy consumption. The regression model of optimization criterion was constructed based on the experimental data. The analysis of the model made it

  20. Minerals in soil select distinct bacterial communities in their microhabitats.

    Science.gov (United States)

    Carson, Jennifer K; Campbell, Louise; Rooney, Deirdre; Clipson, Nicholas; Gleeson, Deirdre B

    2009-03-01

    We tested the hypothesis that different minerals in soil select distinct bacterial communities in their microhabitats. Mica (M), basalt (B) and rock phosphate (RP) were incubated separately in soil planted with Trifolium subterraneum, Lolium rigidum or left unplanted. After 70 days, the mineral and soil fractions were separated by sieving. Automated ribosomal intergenic spacer analysis was used to determine whether the bacterial community structure was affected by the mineral, fraction and plant treatments. Principal coordinate plots showed clustering of bacterial communities from different fraction and mineral treatments, but not from different plant treatments. Permutational multivariate anova (permanova) showed that the microhabitats of M, B and RP selected bacterial communities different from each other in unplanted and L. rigidum, and in T. subterraneum, bacterial communities from M and B differed (Ppermanova also showed that each mineral fraction selected bacterial communities different from the surrounding soil fraction (P<0.05). This study shows that the structure of bacterial communities in soil is influenced by the mineral substrates in their microhabitat and that minerals in soil play a greater role in bacterial ecology than simply providing an inert matrix for bacterial growth. This study suggests that mineral heterogeneity in soil contributes to the spatial variation in bacterial communities.

  1. Evaluation and Optimization of a Traditional North-Light Roof on Industrial Plant Energy Consumption

    Energy Technology Data Exchange (ETDEWEB)

    Adriaenssens, Sigrid [Form-Finding Lab, Department of Civil and Environmental Engineering, School of Engineering and Applied Science, Princeton Univ., NJ (United States); Hao Liu [Center for Intelligent and Networked Systems, Department of Automation, Tsinghua National Laboratory for Information Science and Technology, Tsinghua University, Beijing (China); Wahed, Miriam [Form-Finding Lab, Department of Civil and Environmental Engineering, School of Engineering and Applied Science, Princeton Univ., NJ (United States); Qianchuan Zhao [Center for Intelligent and Networked Systems, Department of Automation, Tsinghua National Laboratory for Information Science and Technology, Tsinghua University, Beijing (China)

    2013-04-15

    Increasingly strict energy policies, rising energy prices, and a desire for a positive corporate image currently serve as incentives for multinational corporations to reduce their plants’ energy consumption. This paper quantitatively investigates and discusses the value of a traditional north-light roof using a complete building energy simulation and optimization framework. The findings indicate that the north-light system yields positive building energy performance for several climate zones, including: (i) Humid Subtropical; (ii) Semiarid Continental; (iii) Mediterranean; and (iv) Subtropical Highland. In the Subtropical Highland climate zone, for example, the building energy consumption of a north-light roof is up to 54% less than that of a conventional flat roof. Based on these positive findings, this paper further presents an optimization framework that alters the north-light roof shape to further improve its energy performance. To quantitatively guarantee a high probability of finding satisfactory designs while reducing the computational processing time, ordinal optimization is introduced into the scheme. The Subtropical Highland case study shows further energy building consumption reduction of 26% for an optimized north-light roof shape. The presented evaluation and optimization framework could be used in designing a plant with integrated north-lights roof that aim at energy efficiency while maintaining environmental occupant comfort levels.

  2. Optimization of light collection from crystal scintillators for cryogenic experiments

    International Nuclear Information System (INIS)

    Mokina, V.M.; Danevich, F.A.; Kobychev, V.V.; Kraus, H.; Mikhailik, V.B.; Nagornaya, L.L.

    2012-01-01

    Cryogenic scintillation bolometers are a promising technique to search for dark matter and neutrinoless double decay. Improvement of light collection and energy resolution are important requirements in such experiments. Energy resolutions and relative pulse amplitudes of scintillation detectors using ZnWO 4 scintillation crystals of different shapes (cylinder 20x20 mm and hexagonal prism with diagonal 20 mm and height 20 mm), reflector materials and shapes, optical contact and surface properties (polished and diffused) were measured. The crystal scintillator of hexagonal shape shows the better energy resolution and pulse amplitude. The best energy resolution (FWHM = 9.3 % for 662 keV γ quanta of 137 Cs) was obtained with a hexagonal scintillator with all surfaces diffuse, in optical contact with a PMT and surrounded by a reflector (3M) of size 26x25 mm. In the geometry w ithout optical contact r epresenting the conditions of light collection for a cryogenic scintillating bolometer the best energy resolution and relative pulse amplitude was obtained for a hexagonal shape scintillator with diffuse side and polished face surfaces, surrounded by a reflector with a gap between the scintillator and the reflector

  3. Optimization of the light extraction from heavy inorganic scintillators

    CERN Document Server

    Kronberger, Matthias; Lecoq, P

    2008-01-01

    Inorganic scintillators are widely used in modern medical imaging modalities as converter for the X- and gamma-radiation that is used to obtain information about the interior of the body. Likewise, they are applied in high-energy physics to measure the energy of particles that are produced in particle physics experiments. Their use is motivated by the very good detection efficiency of these materials for hard radiation which allows the construction of relatively compact and finely pixelised systems with a high spatial resolution. One key problem in the development of the next generation of particle detectors and medical imaging systems is the optimisation of the energy resolution of the detectors. This parameter is influenced by the statistical fluctuations of the light output of the scintillators, i.e. by the number of photons that are detected when a particle deposits its energy in the scintillator. The light output of the scintillator depends not only on the absolute number of generated photons but also on...

  4. Compound light ion fuel cycles: An approach to optimization

    International Nuclear Information System (INIS)

    Kernbichler, W.; Heindler, M.

    1985-01-01

    Together with the relatively high complexity and the low power density anticipated for fusion reactors have produced different attitude towards the long term perspective of fusion as a commercial energy source. The favourite pathway is to trust in optimization aiming at low tritium inventory, the availability of low-activation structure materials, the increase of redundancy, etc. In contrast, a respectable minority suggests turning away from d-t fusion or to envisage fusion as powerful neutron rather than energy source (fusion as fissile fuel or synfuel factory). We here intend to investigate the potentiality of fusion based on alternatives to d-t fuel. Such so called ''advanced fuels'' require higher burn temperatures and advanced reactor concepts (high-beta confinement schemes to compensate for their inherently lower reactivities. The experience that has been gained in fusion oriented plasma research admittedly justifies optimism for advanced fuels to a still lesser extent than for d-t. It can however be argued that it may pay off to choose a developmental direction with higher risk for failure but aiming at a more desirable end product. In order to explore this eventual desirability of advanced fuel fusion, we assume, as has been done in the case of d-t, that the first category of problems can be successfully handled. Our goal is thus to examine the potentiality of advanced fuels with respect to the second category of problems which largely determines the attractivity of utilization in fusion reactors

  5. Adjusted light and dark cycles can optimize photosynthetic efficiency in algae growing in photobioreactors.

    Directory of Open Access Journals (Sweden)

    Eleonora Sforza

    Full Text Available Biofuels from algae are highly interesting as renewable energy sources to replace, at least partially, fossil fuels, but great research efforts are still needed to optimize growth parameters to develop competitive large-scale cultivation systems. One factor with a seminal influence on productivity is light availability. Light energy fully supports algal growth, but it leads to oxidative stress if illumination is in excess. In this work, the influence of light intensity on the growth and lipid productivity of Nannochloropsis salina was investigated in a flat-bed photobioreactor designed to minimize cells self-shading. The influence of various light intensities was studied with both continuous illumination and alternation of light and dark cycles at various frequencies, which mimic illumination variations in a photobioreactor due to mixing. Results show that Nannochloropsis can efficiently exploit even very intense light, provided that dark cycles occur to allow for re-oxidation of the electron transporters of the photosynthetic apparatus. If alternation of light and dark is not optimal, algae undergo radiation damage and photosynthetic productivity is greatly reduced. Our results demonstrate that, in a photobioreactor for the cultivation of algae, optimizing mixing is essential in order to ensure that the algae exploit light energy efficiently.

  6. Dynamic Aperture Optimization for Low Emittance Light Sources

    CERN Document Server

    Kramer, Stephen L

    2005-01-01

    State of the art low emittance light source lattices, require small bend angle dipole magnets and strong quadrupoles. This in turn creates large chromaticity and small value of dispersion in the lattice. To counter the high chromaticity strong sextupoles are required which limit the dynamic aperture. Traditional methods for expanding the dynamic aperture use harmonic sextupoles to counter the tune shift with amplitude. This has been successful up to now, but is non-deterministic and limited as the sextupole strength increases, driving higher order nonlinearities. We have taken a different approach that makes use of the tune flexibility of a TBA lattice to minimize the lowest order nonlinearities, freeing the harmonic sextupoles to counter the higher order nonlinearities. This procedure is being used to improve the nonlinear dynamics of the NSLS-II lattice.

  7. Optimization of emission color and efficiency of organic light emitting diodes for lighting applications

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, Stefan; Krause, Ralf [Department of Materials Science VI, University of Erlangen-Nuernberg (Germany); Siemens AG, CT MM 1, Erlangen (Germany); Kozlowski, Fryderyk; Schmid, Guenter; Hunze, Arvid [Siemens AG, CT MM 1, Erlangen (Germany); Winnacker, Albrecht [Department of Materials Science VI, University of Erlangen-Nuernberg (Germany)

    2008-07-01

    In recent years the performance of organic light emitting diodes (OLEDs) has reached a level where OLED lighting presents an interesting application target. Research activities therefore focus amongst other things on the development of high efficient and stable white light emitting devices. We demonstrate how the color coordinates can be adjusted to achieve a warm white emission spectrum, whereas the OLED stack contains phosphorescent red and green dyes combined with a fluorescent blue one. Detailed results are presented with respect to a variation of layer thicknesses and dopant concentrations of the emission layers. Furthermore the influence of various dye molecules and hence different energy level alignments between host and dopants on color and efficiency will be discussed.

  8. Optimization of Multiband White-Light Illuminants for Specified Color Temperatures

    Directory of Open Access Journals (Sweden)

    Snjezana Soltic

    2015-01-01

    Full Text Available This paper describes an effective approach for the optimization of multiband spectra to produce prospective white-light spectra having specific color temperatures. The optimization process employs a genetic algorithm known as differential evolution, which aims to minimize the color rendering differences between a prospective white-light spectrum and its corresponding reference illuminant. Color rendering is assessed by calculating the CIEDE2000 color difference (ΔE00 for 14 CIE test colors under the two sources. Optimized white-light spectra were matched to three CIE standard illuminants, that is, A (2856 K, D50 (5003 K, and D65 (6504 K. Optimal solutions for three- and four-band 25 and 50 nm Gaussian spectra are presented and analyzed, together with mixed 4-LED spectra that were optimized in the same way. In all cases, the simulated sources were shown to provide color rendering of such quality that ΔE00av ≤ 2.24 units. Such white-light sources would likely find wide acceptance in numerous lighting applications.

  9. A photobioreactor for microalgae cultivation with internal illumination considering flashing light effect and optimized light-source arrangement

    International Nuclear Information System (INIS)

    Hu, Jin-Yang; Sato, Toru

    2017-01-01

    Highlights: • This bioreactor for microalgae provides the optimized arrangement of internal LEDs. • Flashing-light effect of the photosynthesis was demonstrated. • A cell density of 67% of that of the ideal condition was measured. • Numerical simulations predict the largest growth rate of 10.18 g/L/day. - Abstract: In this study, a photobioreactor for mass-culturing microalgae was developed. Because of the optimized arrangement of internal light-emitting diode (LED) illumination, a major advantage to this reactor is that the volume of the reactor vessel is not limited. Using Dunaliella tertiolecta as the microalgae, the bioreactor displayed the flashing-light effect of the microalgae photosynthesis process. This phenomenon was achieved using a series of blue and red LEDs set at appropriate positions within the reactor to evenly distribute the light intensity. Our experimental results suggested that the maximum cell density in the culture experiment was 1.88 × 10"3 cells L"−"1, which is approximately 67% of the maximum density under ideal conditions. The harvest yield of the algae was estimated by a numerical model using measured parameters; it was predicted that the bioreactor developed in this study can attain a high growth rate of D. tertiolecta by controlling the distance between LEDs.

  10. Near optimal discrimination of binary coherent signals via atom–light interaction

    Science.gov (United States)

    Han, Rui; Bergou, János A.; Leuchs, Gerd

    2018-04-01

    We study the discrimination of weak coherent states of light with significant overlaps by nondestructive measurements on the light states through measuring atomic states that are entangled to the coherent states via dipole coupling. In this way, the problem of measuring and discriminating coherent light states is shifted to finding the appropriate atom–light interaction and atomic measurements. We show that this scheme allows us to attain a probability of error extremely close to the Helstrom bound, the ultimate quantum limit for discriminating binary quantum states, through the simple Jaynes–Cummings interaction between the field and ancilla with optimized light–atom coupling and projective measurements on the atomic states. Moreover, since the measurement is nondestructive on the light state, information that is not detected by one measurement can be extracted from the post-measurement light states through subsequent measurements.

  11. Optimal wavelength scale diffraction gratings for light trapping in solar cells

    International Nuclear Information System (INIS)

    Chong, Teck Kong; Wilson, Jonathan; Mokkapati, Sudha; Catchpole, Kylie R

    2012-01-01

    Dielectric gratings are a promising method of achieving light trapping for thin crystalline silicon solar cells. In this paper, we systematically examine the potential performance of thin silicon solar cells with either silicon (Si) or titanium dioxide (TiO 2 ) gratings using numerical simulations. The square pyramid structure with silicon nitride coating provides the best light trapping among all the symmetric structures investigated, with 89% of the expected short circuit current density of the Lambertian case. For structures where the grating is at the rear of the cell, we show that the light trapping provided by the square pyramid and the checkerboard structure is almost identical. Introducing asymmetry into the grating structures can further improve their light trapping properties. An optimized Si skewed pyramid grating on the front surface of the solar cell results in a maximum short circuit current density, J sc , of 33.4 mA cm −2 , which is 91% of the J sc expected from an ideal Lambertian scatterer. An optimized Si skewed pyramid grating on the rear performs as well as a rear Lambertian scatterer and an optimized TiO 2 grating on the rear results in 84% of the J sc expected from an optimized Si grating. The results show that submicron symmetric and skewed pyramids of Si or TiO 2 are a highly effective way of achieving light trapping in thin film solar cells. TiO 2 structures would have the additional advantage of not increasing recombination within the cell. (paper)

  12. Seasonality and microhabitat selection in a forest-dwelling salamander

    Science.gov (United States)

    Basile, Marco; Romano, Antonio; Costa, Andrea; Posillico, Mario; Scinti Roger, Daniele; Crisci, Aldo; Raimondi, Ranieri; Altea, Tiziana; Garfì, Vittorio; Santopuoli, Giovanni; Marchetti, Marco; Salvidio, Sebastiano; De Cinti, Bruno; Matteucci, Giorgio

    2017-10-01

    Many small terrestrial vertebrates exhibit limited spatial movement and are considerably exposed to changes in local environmental variables. Among such vertebrates, amphibians at present experience a dramatic decline due to their limited resilience to environmental change. Since the local survival and abundance of amphibians is intrinsically related to the availability of shelters, conservation plans need to take microhabitat requirements into account. In order to gain insight into the terrestrial ecology of the spectacled salamander Salamandrina perspicillata and to identify appropriate forest management strategies, we investigated the salamander's seasonal variability in habitat use of trees as shelters in relation to tree features (size, buttresses, basal holes) and environmental variables in a beech forest in Italy. We used the occupancy approach to assess tree suitability on a non-conventional spatial scale. Our approach provides fine-grained parameters of microhabitat suitability and elucidates many aspects of the salamander's terrestrial ecology . Occupancy changed with the annual life cycle and was higher in autumn than in spring, when females were found closer to the stream in the study area. Salamanders showed a seasonal pattern regarding the trees they occupied and a clear preference for trees with a larger diameter and more burrows. With respect to forest management, we suggest maintaining a suitable number of trees with a trunk diameter exceeding 30 cm. A practice of selective logging along the banks of streams could help maintain an adequate quantity of the appropriate microhabitat. Furthermore, in areas with a presence of salamanders, a good forest management plan requires leaving an adequate buffer zone around streams, which should be wider in autumn than in spring.

  13. Evidence-Based Recommendations for Optimizing Light in Day-to-Day Spaceflight Operations

    Science.gov (United States)

    Whitmire, Alexandra; Leveton, Lauren; Barger, Laura; Clark, Toni; Bollweg, Laura; Ohnesorge, Kristine; Brainard, George

    2015-01-01

    NASA Behavioral Health and Performance Element (BHP) personnel have previously reported on efforts to transition evidence-based recommendations for a flexible lighting system on the International Space Station (ISS). Based on these recommendations, beginning in 2016 the ISS will replace the current fluorescent-based lights with an LED-based system to optimize visual performance, facilitate circadian alignment, promote sleep, and hasten schedule shifting. Additional efforts related to lighting countermeasures in spaceflight operations have also been underway. As an example, a recent BHP research study led by investigators at Harvard Medical School and Brigham and Women's Hospital, evaluated the acceptability, feasibility, and effectiveness of blue-enriched light exposure during exercise breaks for flight controllers working the overnight shift in the Mission Control Center (MCC) at NASA Johnson Space Center. This effort, along with published laboratory studies that have demonstrated the effectiveness of appropriately timed light for promoting alertness, served as an impetus for new light options, and educational protocols for flight controllers. In addition, a separate set of guidelines related to the light emitted from electronic devices, were provided to the Astronaut Office this past year. These guidelines were based on an assessment led by NASA's Lighting Environment Test Facility that included measuring the spectral power distribution, irradiance, and radiance of light emitted from ISS-grade laptops and I-Pads, as well as Android devices. Evaluations were conducted with and without the use of off-the-shelf screen filters as well as a software application that touts minimizing the short-wave length of the visible light spectrum. This presentation will focus on the transition for operations process related to lighting countermeasures in the MCC, as well as the evidence to support recommendations for optimal use of laptops, I-Pads, and Android devices during all

  14. 3D Monte Carlo model with direct photon flux recording for optimal optogenetic light delivery

    Science.gov (United States)

    Shin, Younghoon; Kim, Dongmok; Lee, Jihoon; Kwon, Hyuk-Sang

    2017-02-01

    Configuring the light power emitted from the optical fiber is an essential first step in planning in-vivo optogenetic experiments. However, diffusion theory, which was adopted for optogenetic research, precluded accurate estimates of light intensity in the semi-diffusive region where the primary locus of the stimulation is located. We present a 3D Monte Carlo model that provides an accurate and direct solution for light distribution in this region. Our method directly records the photon trajectory in the separate volumetric grid planes for the near-source recording efficiency gain, and it incorporates a 3D brain mesh to support both homogeneous and heterogeneous brain tissue. We investigated the light emitted from optical fibers in brain tissue in 3D, and we applied the results to design optimal light delivery parameters for precise optogenetic manipulation by considering the fiber output power, wavelength, fiber-to-target distance, and the area of neural tissue activation.

  15. Design optimization on the drive train of a light-weight robotic arm

    DEFF Research Database (Denmark)

    Zhou, Lelai; Bai, Shaoping; Hansen, Michael Rygaard

    2011-01-01

    A drive train optimization method for design of light-weight robots is proposed. Optimal selections of motors and gearboxes from a limited catalog of commercially available components are done simultaneously for all joints of a robotic arm. Characteristics of the motor and gearbox, including gear...... ratio, gear inertia, motor inertia, and gear efficiency, are considered in the drive train modeling. A co-simulation method is developed for dynamic simulation of the arm. A design example is included to demonstrate the proposed design optimization method....

  16. Shell colour, temperature, (micro)habitat structure and predator pressure affect the behaviour of Cepaea nemoralis

    Science.gov (United States)

    Rosin, Zuzanna M.; Kwieciński, Zbigniew; Lesicki, Andrzej; Skórka, Piotr; Kobak, Jarosław; Szymańska, Anna; Osiejuk, Tomasz S.; Kałuski, Tomasz; Jaskulska, Monika; Tryjanowski, Piotr

    2018-06-01

    Although shell colour polymorphism of the land snail Cepaea nemoralis is a well-known phenomenon, proximate and ultimate factors driving its evolution remain uncertain. Polymorphic species show variation in behavioural responses to selective forces. Therefore, we estimated effects of various environmental factors (temperature, humidity, food availability, (micro)habitat structure and predatory pressure) on behavioural response (frequency of locomotion, climbing and hiding) of C. nemoralis morphs, in experimental and natural conditions. In the experimental part of study, the frequency of locomotion was negatively affected by temperature and the presence of food and positively influenced by the presence of light. Morphs significantly differed in behavioural responses to environmental variability. Pink mid-banded and yellow five-banded morphs climbed less often and hide in shelter more often than yellow and pink unbanded individuals when temperature was low and food was absent. Snails fed most often at moderate temperature compared to low and high temperatures. Field investigations partially confirmed differences among morphs in frequency of climbing, but not in terms of probability of hiding in sheltered sites. In natural colonies, temperature and (micro)habitat structure significantly affected frequency of climbing as well as hiding in shelter. Snails more often hid in sheltered sites where thrushes preyed on Cepaea. Tendency of unbanded morphs to climb trees may have evolved under avian predatory pressure as thrushes forage on a ground. Tendency of banded morphs to hide in sheltered sites may reflect prey preferences for cryptic background. The results implicate that differential behaviour of C. nemoralis morphs compensate for their morphological and physiological limitations of adaptation to habitat.

  17. Diversification rates are more strongly related to microhabitat than climate in squamate reptiles (lizards and snakes).

    Science.gov (United States)

    Bars-Closel, Melissa; Kohlsdorf, Tiana; Moen, Daniel S; Wiens, John J

    2017-09-01

    Patterns of species richness among clades can be directly explained by the ages of clades or their rates of diversification. The factors that most strongly influence diversification rates remain highly uncertain, since most studies typically consider only a single predictor variable. Here, we explore the relative impacts of macroclimate (i.e., occurring in tropical vs. temperate regions) and microhabitat use (i.e., terrestrial, fossorial, arboreal, aquatic) on diversification rates of squamate reptile clades (lizards and snakes). We obtained data on microhabitat, macroclimatic distribution, and phylogeny for >4000 species. We estimated diversification rates of squamate clades (mostly families) from a time-calibrated tree, and used phylogenetic methods to test relationships between diversification rates and microhabitat and macroclimate. Across 72 squamate clades, the best-fitting model included microhabitat but not climatic distribution. Microhabitat explained ∼37% of the variation in diversification rates among clades, with a generally positive impact of arboreal microhabitat use on diversification, and negative impacts of fossorial and aquatic microhabitat use. Overall, our results show that the impacts of microhabitat on diversification rates can be more important than those of climate, despite much greater emphasis on climate in previous studies. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  18. Spectral optimization simulation of white light based on the photopic eye-sensitivity curve

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Qi, E-mail: qidai@tongji.edu.cn [College of Architecture and Urban Planning, Tongji University, 1239 Siping Road, Shanghai 200092 (China); Institute for Advanced Study, Tongji University, 1239 Siping Road, Shanghai 200092 (China); Key Laboratory of Ecology and Energy-saving Study of Dense Habitat (Tongji University), Ministry of Education, 1239 Siping Road, Shanghai 200092 (China); Hao, Luoxi; Lin, Yi; Cui, Zhe [College of Architecture and Urban Planning, Tongji University, 1239 Siping Road, Shanghai 200092 (China); Key Laboratory of Ecology and Energy-saving Study of Dense Habitat (Tongji University), Ministry of Education, 1239 Siping Road, Shanghai 200092 (China)

    2016-02-07

    Spectral optimization simulation of white light is studied to boost maximum attainable luminous efficacy of radiation at high color-rendering index (CRI) and various color temperatures. The photopic eye-sensitivity curve V(λ) is utilized as the dominant portion of white light spectra. Emission spectra of a blue InGaN light-emitting diode (LED) and a red AlInGaP LED are added to the spectrum of V(λ) to match white color coordinates. It is demonstrated that at the condition of color temperature from 2500 K to 6500 K and CRI above 90, such white sources can achieve spectral efficacy of 330–390 lm/W, which is higher than the previously reported theoretical maximum values. We show that this eye-sensitivity-based approach also has advantages on component energy conversion efficiency compared with previously reported optimization solutions.

  19. Spectral optimization simulation of white light based on the photopic eye-sensitivity curve

    International Nuclear Information System (INIS)

    Dai, Qi; Hao, Luoxi; Lin, Yi; Cui, Zhe

    2016-01-01

    Spectral optimization simulation of white light is studied to boost maximum attainable luminous efficacy of radiation at high color-rendering index (CRI) and various color temperatures. The photopic eye-sensitivity curve V(λ) is utilized as the dominant portion of white light spectra. Emission spectra of a blue InGaN light-emitting diode (LED) and a red AlInGaP LED are added to the spectrum of V(λ) to match white color coordinates. It is demonstrated that at the condition of color temperature from 2500 K to 6500 K and CRI above 90, such white sources can achieve spectral efficacy of 330–390 lm/W, which is higher than the previously reported theoretical maximum values. We show that this eye-sensitivity-based approach also has advantages on component energy conversion efficiency compared with previously reported optimization solutions

  20. Monte Carlo simulations for optimal light delivery in photodynamic therapy of non-melanoma skin cancer

    International Nuclear Information System (INIS)

    Valentine, R M; Ibbotson, S H; Moseley, H; Wood, K; Brown, C T A

    2012-01-01

    The choice of light source is important for the efficacy of photodynamic therapy (PDT) of non-melanoma skin cancer. We simulated the photodynamic dose (PDD) delivered to a tumour during PDT using theoretical radiation transfer simulations performed via our 3D Monte Carlo radiation transfer (MCRT) model for a range of light sources with light doses up to 75 J cm −2 . The PDD delivered following superficial irradiation from (A) non-laser light sources, (B) monochromatic light, (C) alternate beam diameters and (D) re-positioning of the tumour within the tissue was computed. (A) The final PDD deposited to the tumour at a depth of 2 mm by the Paterson light source was 2.75, 2.50 and 1.04 times greater than the Waldmann 1200, Photocure and Aktilite, respectively. (B) Tumour necrosis occurred at a depth of 2.23 mm and increased to 3.81 mm for wavelengths 405 and 630 nm, respectively. (C) Increasing the beam diameter from 10 to 50 mm had very little effect on depth of necrosis. (D) As expected, necrosis depths were reduced when the tumour was re-positioned deeper into the tissue. These MCRT simulations show clearly the importance of choosing the correct light source to ensure optimal light delivery to achieve tumour necrosis. (paper)

  1. Optimization of light source parameters in the photodynamic therapy of heterogeneous prostate

    International Nuclear Information System (INIS)

    Li Jun; Altschuler, Martin D; Hahn, Stephen M; Zhu, Timothy C

    2008-01-01

    The three-dimensional (3D) heterogeneous distributions of optical properties in a patient prostate can now be measured in vivo. Such data can be used to obtain a more accurate light-fluence kernel. (For specified sources and points, the kernel gives the fluence delivered to a point by a source of unit strength.) In turn, the kernel can be used to solve the inverse problem that determines the source strengths needed to deliver a prescribed photodynamic therapy (PDT) dose (or light-fluence) distribution within the prostate (assuming uniform drug concentration). We have developed and tested computational procedures to use the new heterogeneous data to optimize delivered light-fluence. New problems arise, however, in quickly obtaining an accurate kernel following the insertion of interstitial light sources and data acquisition. (1) The light-fluence kernel must be calculated in 3D and separately for each light source, which increases kernel size. (2) An accurate kernel for light scattering in a heterogeneous medium requires ray tracing and volume partitioning, thus significant calculation time. To address these problems, two different kernels were examined and compared for speed of creation and accuracy of dose. Kernels derived more quickly involve simpler algorithms. Our goal is to achieve optimal dose planning with patient-specific heterogeneous optical data applied through accurate kernels, all within clinical times. The optimization process is restricted to accepting the given (interstitially inserted) sources, and determining the best source strengths with which to obtain a prescribed dose. The Cimmino feasibility algorithm is used for this purpose. The dose distribution and source weights obtained for each kernel are analyzed. In clinical use, optimization will also be performed prior to source insertion to obtain initial source positions, source lengths and source weights, but with the assumption of homogeneous optical properties. For this reason, we compare the

  2. Replacement policy of residential lighting optimized for cost, energy, and greenhouse gas emissions

    Science.gov (United States)

    Liu, Lixi; Keoleian, Gregory A.; Saitou, Kazuhiro

    2017-11-01

    Accounting for 10% of the electricity consumption in the US, artificial lighting represents one of the easiest ways to cut household energy bills and greenhouse gas (GHG) emissions by upgrading to energy-efficient technologies such as compact fluorescent lamps (CFL) and light emitting diodes (LED). However, given the high initial cost and rapidly improving trajectory of solid-state lighting today, estimating the right time to switch over to LEDs from a cost, primary energy, and GHG emissions perspective is not a straightforward problem. This is an optimal replacement problem that depends on many determinants, including how often the lamp is used, the state of the initial lamp, and the trajectories of lighting technology and of electricity generation. In this paper, multiple replacement scenarios of a 60 watt-equivalent A19 lamp are analyzed and for each scenario, a few replacement policies are recommended. For example, at an average use of 3 hr day-1 (US average), it may be optimal both economically and energetically to delay the adoption of LEDs until 2020 with the use of CFLs, whereas purchasing LEDs today may be optimal in terms of GHG emissions. In contrast, incandescent and halogen lamps should be replaced immediately. Based on expected LED improvement, upgrading LED lamps before the end of their rated lifetime may provide cost and environmental savings over time by taking advantage of the higher energy efficiency of newer models.

  3. Optimality study of a gust alleviation system for light wing-loading STOL aircraft

    Science.gov (United States)

    Komoda, M.

    1976-01-01

    An analytical study was made of an optimal gust alleviation system that employs a vertical gust sensor mounted forward of an aircraft's center of gravity. Frequency domain optimization techniques were employed to synthesize the optimal filters that process the corrective signals to the flaps and elevator actuators. Special attention was given to evaluating the effectiveness of lead time, that is, the time by which relative wind sensor information should lead the actual encounter of the gust. The resulting filter is expressed as an implicit function of the prescribed control cost. A numerical example for a light wing loading STOL aircraft is included in which the optimal trade-off between performance and control cost is systematically studied.

  4. Optimizing Greenhouse Lighting for Advanced Agriculture Based on Real Time Electricity Market Price

    Directory of Open Access Journals (Sweden)

    Mehdi Mahdavian

    2017-01-01

    Full Text Available The world’s growing demand for food can be met by agricultural technology. Use of artificial light to supplement natural sunlight in greenhouse cultivation is one of the most common techniques to increase greenhouse production of food crops. However, artificial light requires significant electrical energy, which increases the cost of greenhouse production and can reduce profit. This paper models the increments to greenhouse productivity as well as the increases in cost from supplemental electric lighting, in a situation where the greenhouse is one of the elements of a smart grid, a system where the electric energy market is dynamic and prices vary over time. We used our models to calculate the optimum values for supplemental light and the required electrical energy for HPS lamps in the greenhouse environment, using cherry tomato cultivation as a case study crop. We considered two optimization techniques: iterative search (IS and genetic algorithm (GA. The two approaches produced similar results, although the GA method was much faster. Both approaches verify the advantages of using optimal supplemental light in terms of increasing production and hence profit.

  5. Optimization of Serum Immunoglobulin Free Light Chain Analysis for Subclassification of Cardiac Amyloidosis.

    Science.gov (United States)

    Halushka, Marc K; Eng, George; Collins, A Bernard; Judge, Daniel P; Semigran, Marc J; Stone, James R

    2015-06-01

    Accurate and rapid classification of cardiac amyloidosis is important for patient management. We have optimized the use of serum free light chain kappa and lambda values to differentiate immunoglobulin light chain amyloid (AL) amyloidosis from transthyretin amyloid and amyloid A using 85 cases of tissue-proven cardiac amyloidosis, in which there was direct classification of amyloidosis by mass spectrometry or immunofluorescence. The serum free light chain kappa/lambda ratios were non-overlapping for the three major groups: AL-lambda (0.01-0.41, n = 30), non-AL (0.52-2.7, n = 43), and AL-kappa (6.7-967, n = 12). A kappa/lambda ratio value between 0.5 and 5.0 had 100 % sensitivity and 100 % specificity for distinguishing AL amyloidosis from non-AL amyloidosis. This optimized range for serum light chain kappa/lambda ratio provides extremely robust classification of cardiac amyloidosis. Cases of cardiac amyloidosis in which the serum kappa/lambda free light chain ratio falls close to these new cutoff values may benefit most from direct amyloid subtyping.

  6. AN OPTIMALIZATION OF NATURAL LIGHTING BY APPLYING AUTOMATIC LIGHTING USING MOTION SENSOR AND LUX SENSOR FOR HISTORICAL OLD BUILDINGS

    Directory of Open Access Journals (Sweden)

    Saeful Bahri

    2016-07-01

    Full Text Available ABSTRACT One of the problems that occurs within city centres, particularly within capital cities, is the existence of many historical old buildings. Historical old buildings within city centres, that have abandoned for years because of their condition, suffer from a lack of utilities, infrastructure and facilities [2][3]. These conditions occur because of low levels of maintenance arising as a consequence of a lack of finance of the owner of a building, be they government or private sector. To solve the problem of abandoned historical old buildings, the concept of adaptive reuse can be adopted and applied. This concept of adaptive reuse may continously cover the cost of building maintenance. The adaptive reuse concept usually covers the interior of a building and its utilities, though the need for utilities depends on the function of a building [4]. By adopting a concept of adaptive reuse, new building functions will be designed as the needs and demand of the market dictate, and which is appropriate for feasibility study. One utility element that has to be designed for historical old buildings is the provision of lighting within a building. To minimize the cost of building maintenance, one of the solutions is to optimize natural lighting and to minimize the use of artificial lighting such as lamps. This paper will discuss the extent to which artificial lighting can be minimized by using automatic lighting; the automatic lighting types discussed in this paper are lighting controlled by motion sensor and lux sensor. Keywords: Natural lighting, automatic lighting, motion sensor, lux sensor, historical old buildings ABSTRAK Salah satu permasalahan yang muncul dalam sebuah kota metropolitan, khususnya sebuah ibukota adalah keberadaan dari banyaknya bangunan-bangunan tua bersejarah. Bangunan-bangunan tua bersejarah dalam sebuah kota besar terutama yang diabaikan selama bertahun-tahun biasanya disebabkan karena kondisinya yang menua, minimnya utilitas

  7. Optimization of colour quality of LED lighting with reference to memory colours

    OpenAIRE

    Smet, Kevin; Ryckaert, Wouter; Pointer, Michael R.; Deconinck, Geert; Hanselaer, Peter

    2012-01-01

    Simulated and real tri- and tetrachromatic light-emitting-diode (LED) clusters were optimized for luminous efficacy of radiation (LER) and the memory colour quality metric developed by the authors. The simulated clusters showed no significant differences in achievable colour quality and LER between the different cluster types investigated. The real clusters (composed of commercially available LEDs) showed substantial differences in achievable colour quality and LER between the different clus...

  8. Optimal sampling plan for clean development mechanism energy efficiency lighting projects

    International Nuclear Information System (INIS)

    Ye, Xianming; Xia, Xiaohua; Zhang, Jiangfeng

    2013-01-01

    Highlights: • A metering cost minimisation model is built to assist the sampling plan for CDM projects. • The model minimises the total metering cost by the determination of optimal sample size. • The required 90/10 criterion sampling accuracy is maintained. • The proposed metering cost minimisation model is applicable to other CDM projects as well. - Abstract: Clean development mechanism (CDM) project developers are always interested in achieving required measurement accuracies with the least metering cost. In this paper, a metering cost minimisation model is proposed for the sampling plan of a specific CDM energy efficiency lighting project. The problem arises from the particular CDM sampling requirement of 90% confidence and 10% precision for the small-scale CDM energy efficiency projects, which is known as the 90/10 criterion. The 90/10 criterion can be met through solving the metering cost minimisation problem. All the lights in the project are classified into different groups according to uncertainties of the lighting energy consumption, which are characterised by their statistical coefficient of variance (CV). Samples from each group are randomly selected to install power meters. These meters include less expensive ones with less functionality and more expensive ones with greater functionality. The metering cost minimisation model will minimise the total metering cost through the determination of the optimal sample size at each group. The 90/10 criterion is formulated as constraints to the metering cost objective. The optimal solution to the minimisation problem will therefore minimise the metering cost whilst meeting the 90/10 criterion, and this is verified by a case study. Relationships between the optimal metering cost and the population sizes of the groups, CV values and the meter equipment cost are further explored in three simulations. The metering cost minimisation model proposed for lighting systems is applicable to other CDM projects as

  9. Optimization of particle trapping and patterning via photovoltaic tweezers: role of light modulation and particle size

    International Nuclear Information System (INIS)

    Matarrubia, J; García-Cabañes, A; Plaza, J L; Agulló-López, F; Carrascosa, M

    2014-01-01

    The role of light modulation m and particle size on the morphology and spatial resolution of nano-particle patterns obtained by photovoltaic tweezers on Fe : LiNbO 3 has been investigated. The impact of m when using spherical as well as non-spherical (anisotropic) nano-particles deposited on the sample surface has been elucidated. Light modulation is a key parameter determining the particle profile contrast that is optimum for spherical particles and high-m values (m ∼ 1). The minimum particle periodicities reachable are also investigated obtaining periodic patterns up to 3.5 µm. This is a value at least one order of magnitude shorter than those obtained in previous reported experiments. Results are successfully explained and discussed in light of the previous reported models for photorefraction including nonlinear carrier transport and dielectrophoretic trapping. From the results, a number of rules for particle patterning optimization are derived. (paper)

  10. Optimization of spatial light distribution through genetic algorithms for vision systems applied to quality control

    International Nuclear Information System (INIS)

    Castellini, P; Cecchini, S; Stroppa, L; Paone, N

    2015-01-01

    The paper presents an adaptive illumination system for image quality enhancement in vision-based quality control systems. In particular, a spatial modulation of illumination intensity is proposed in order to improve image quality, thus compensating for different target scattering properties, local reflections and fluctuations of ambient light. The desired spatial modulation of illumination is obtained by a digital light projector, used to illuminate the scene with an arbitrary spatial distribution of light intensity, designed to improve feature extraction in the region of interest. The spatial distribution of illumination is optimized by running a genetic algorithm. An image quality estimator is used to close the feedback loop and to stop iterations once the desired image quality is reached. The technique proves particularly valuable for optimizing the spatial illumination distribution in the region of interest, with the remarkable capability of the genetic algorithm to adapt the light distribution to very different target reflectivity and ambient conditions. The final objective of the proposed technique is the improvement of the matching score in the recognition of parts through matching algorithms, hence of the diagnosis of machine vision-based quality inspections. The procedure has been validated both by a numerical model and by an experimental test, referring to a significant problem of quality control for the washing machine manufacturing industry: the recognition of a metallic clamp. Its applicability to other domains is also presented, specifically for the visual inspection of shoes with retro-reflective tape and T-shirts with paillettes. (paper)

  11. Optimal sampling plan for clean development mechanism lighting projects with lamp population decay

    International Nuclear Information System (INIS)

    Ye, Xianming; Xia, Xiaohua; Zhang, Jiangfeng

    2014-01-01

    Highlights: • A metering cost minimisation model is built with the lamp population decay to optimise CDM lighting projects sampling plan. • The model minimises the total metering cost and optimise the annual sample size during the crediting period. • The required 90/10 criterion sampling accuracy is satisfied for each CDM monitoring report. - Abstract: This paper proposes a metering cost minimisation model that minimises metering cost under the constraints of sampling accuracy requirement for clean development mechanism (CDM) energy efficiency (EE) lighting project. Usually small scale (SSC) CDM EE lighting projects expect a crediting period of 10 years given that the lighting population will decay as time goes by. The SSC CDM sampling guideline requires that the monitored key parameters for the carbon emission reduction quantification must satisfy the sampling accuracy of 90% confidence and 10% precision, known as the 90/10 criterion. For the existing registered CDM lighting projects, sample sizes are either decided by professional judgment or by rule-of-thumb without considering any optimisation. Lighting samples are randomly selected and their energy consumptions are monitored continuously by power meters. In this study, the sampling size determination problem is formulated as a metering cost minimisation model by incorporating a linear lighting decay model as given by the CDM guideline AMS-II.J. The 90/10 criterion is formulated as constraints to the metering cost minimisation problem. Optimal solutions to the problem minimise the metering cost whilst satisfying the 90/10 criterion for each reporting period. The proposed metering cost minimisation model is applicable to other CDM lighting projects with different population decay characteristics as well

  12. Detecting and locating light atoms from high-resolution STEM images: The quest for a single optimal design.

    Science.gov (United States)

    Gonnissen, J; De Backer, A; den Dekker, A J; Sijbers, J; Van Aert, S

    2016-11-01

    In the present paper, the optimal detector design is investigated for both detecting and locating light atoms from high resolution scanning transmission electron microscopy (HR STEM) images. The principles of detection theory are used to quantify the probability of error for the detection of light atoms from HR STEM images. To determine the optimal experiment design for locating light atoms, use is made of the so-called Cramér-Rao Lower Bound (CRLB). It is investigated if a single optimal design can be found for both the detection and location problem of light atoms. Furthermore, the incoming electron dose is optimised for both research goals and it is shown that picometre range precision is feasible for the estimation of the atom positions when using an appropriate incoming electron dose under the optimal detector settings to detect light atoms. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Microhabitat ecology of semi-aquatic Varanus flavescens (Reptilia: Varanidae in altered habitats

    Directory of Open Access Journals (Sweden)

    Mijanur K. M. Rahman

    2016-10-01

    Full Text Available A potential microhabitat is very important for the survival and successful reproduction of any wildlife species. In this study we assessed the microhabitat characteristics of Varanus flavescens in the human altered ecosystems of Chalan beel area, Baraigram, Natore by flowing the Visual Encounter Survey method and by using several important material. A semi-aquatic microhabitat of canal and river was preferred by the species as compared to other identified microhabitats. The slow moving water of the river and canal was fresh and somewhat cloudy in character but stagnant water of the pond and beel (floodplain was semitransparent having lots of phytoplankton and zooplankton. The soil was mostly silty clay. As the study species is cold blooded, the environmental variables like soil, air and water temperatures inside and outside of the microhabitat play major roles for their activity patterns. In order to regulate their body temperature, during a hot sunny day they were more active within the shady area of the microhabitats but at dawn and dusk they were more seen in the sunny areas where temperature was relatively higher. In winter months, the monitor lizards were almost inactive. During that time of the year they live inside the burrow to avoid the extreme cold and foggy weather but during heavy sunshine they come outside of the hole for thermoregulation purpose for a certain time. We noticed that extensive agricultural practice and the excessive use of insecticides may be having a detrimental effect on the microhabitat features important to this semiaquatic lizard. Still the study species is more seen in the human altered ecosystems of Bangladesh. So, to ensure their existence in our close proximity there is an urgent need to create consciousness of the people regarding this beneficial non-venomous species and their respective microhabitat.

  14. Some regularities in invertebrate succession in different microhabitats on pine stumps

    OpenAIRE

    Franch, Joan

    1989-01-01

    Sixty eight pine stumps felled on known dates from one to sixteen years before the moment of sampling have been studied in the San Juan de la Peña woodland (province of Huesca). Four microhabitats were distinguished: bark, subcortical space, sapwood and heartwood. The object of the study is to compare the invertebrate macrofauna succession of the different microhabitats in order to find regularities among them. The biocenosis has not been completely studied: ipidae, diptera and annelidae are ...

  15. Influence of microhabitats on the performance of herbaceous species in areas of mature and secondary forest in the semiarid region of Brazil

    Directory of Open Access Journals (Sweden)

    Juliana Ramos de Andrade

    2015-06-01

    Full Text Available The conditions for plant establishment in mature forest are different from those found in disturbed areas. In dry environments, the herbaceous cover is the most important in the recolonization of deforested areas. It can, therefore, act as an ideal biological group for assessing how changes in habitat heterogeneity affect the resilience of dry forests. The aim of this research was to evaluate whether natural regeneration of the herbaceous stratum differed between areas of mature and secondary forest of Caatinga and to describe this process. The study took place in the Brazilian semiarid region during the rainy season 2011 (January to August, where fifty 1m² plots were set up, 25 allocated to the microhabitat established as “between canopies” and 25 to the microhabitat “under the canopy”. The herbaceous species selected for the study were Delilia biflora (Asteraceae, Gomphrena vaga (Amaranthaceae and Pseudabutilon spicatum (Malvaceae, abundant species occurring in both areas. All individuals from the selected populations were counted, marked with sequential numbers, and the height of the stem was measured. Differences between areas, and in size and survival between microhabitats, were found only for the first two species. Fruit production was higher in the mature forest for the three species. The study concluded that: 1. The effect of the microhabitats “between canopies” and “under the canopy” in mature and secondary forest areas depends on the species considered; 2. Populations sensitive to light intensity differ in number of individuals, height and fruit production; and 3. The resilience of anthropogenic areas in semiarid environments can be characterized by the presence of spatial heterogeneity with regard to the emergence and survival of herbaceous seedlings, suggesting that the regeneration of disturbed areas may occur in patches. Rev. Biol. Trop. 63 (2: 357-368. Epub 2015 June 01.

  16. Road Artery Traffic Light Optimization with Use of the Reinforcement Learning

    Directory of Open Access Journals (Sweden)

    Rok Marsetič

    2014-04-01

    Full Text Available The basic principle of optimal traffic control is the appropriate real-time response to dynamic traffic flow changes. Signal plan efficiency depends on a large number of input parameters. An actuated signal system can adjust very well to traffic conditions, but cannot fully adjust to stochastic traffic volume oscillation. Due to the complexity of the problem analytical methods are not applicable for use in real time, therefore the purpose of this paper is to introduce heuristic method suitable for traffic light optimization in real time. With the evolution of artificial intelligence new possibilities for solving complex problems have been introduced. The goal of this paper is to demonstrate that the use of the Q learning algorithm for traffic lights optimization is suitable. The Q learning algorithm was verified on a road artery with three intersections. For estimation of the effectiveness and efficiency of the proposed algorithm comparison with an actuated signal plan was carried out. The results (average delay per vehicle and the number of vehicles that left road network show that Q learning algorithm outperforms the actuated signal controllers. The proposed algorithm converges to the minimal delay per vehicle regardless of the stochastic nature of traffic. In this research the impact of the model parameters (learning rate, exploration rate, influence of communication between agents and reward type on algorithm effectiveness were analysed as well.

  17. Detecting and locating light atoms from high-resolution STEM images: The quest for a single optimal design

    Energy Technology Data Exchange (ETDEWEB)

    Gonnissen, J.; De Backer, A. [Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Dekker, A.J. den [iMinds-Vision Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Delft Center for Systems and Control (DCSC), Delft University of Technology, Mekelweg 2, 2628 CD Delft (Netherlands); Sijbers, J. [iMinds-Vision Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Van Aert, S., E-mail: sandra.vanaert@uantwerpen.be [Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2016-11-15

    In the present paper, the optimal detector design is investigated for both detecting and locating light atoms from high resolution scanning transmission electron microscopy (HR STEM) images. The principles of detection theory are used to quantify the probability of error for the detection of light atoms from HR STEM images. To determine the optimal experiment design for locating light atoms, use is made of the so-called Cramér–Rao Lower Bound (CRLB). It is investigated if a single optimal design can be found for both the detection and location problem of light atoms. Furthermore, the incoming electron dose is optimised for both research goals and it is shown that picometre range precision is feasible for the estimation of the atom positions when using an appropriate incoming electron dose under the optimal detector settings to detect light atoms. - Highlights: • The optimal detector design to detect and locate light atoms in HR STEM is derived. • The probability of error is quantified and used to detect light atoms. • The Cramér–Rao lower bound is calculated to determine the atomic column precision. • Both measures are evaluated and result in the single optimal LAADF detector regime. • The incoming electron dose is optimised for both research goals.

  18. Wetland and microhabitat use by nesting four-toed salamanders in Maine

    Science.gov (United States)

    Chalmers, R.J.; Loftin, C.S.

    2006-01-01

    Little is known of Four-Toed Salamander (Hemidactylium scutatum) habitat use, despite the species' extensive range and elevated conservation status. We investigated species-habitat relationships that predict H. scutatum nesting presence in Maine at wetland and microhabitat scales by comparing microhabitats with and without nests. We created logistic regression models, selected models with AIC, and evaluated models with reserve data. Wetlands with nests were best predicted by shoreline microhabitat of Sphagnum spp., wood substrate, water flow, blue-joint reed grass (Calamagrostis canadensis), meadowsweet (Spiraea alba), steeplebush (Spiraea tomentosa), sensitive fern (Onoclea sensibilis), and absence of sheep laurel (Kalmia angustifolia) or deciduous forest canopy. Within occupied wetlands, shoreline microhabitat where nests occurred was best distinguished from available, unoccupied shoreline microhabitat by steeper shore, greater near-shore and basin water depth, deeper nesting vegetation, presence of moss spp. and winterberry (Ilex verticillata), and a negative association with S. alba, leatherleaf (Chamaedaphne calyculata), and K. angustifolia. These models of wetland and microhabitat use by H. scutatum may assist ecologists and managers in detecting and conserving this species. Copyright 2006 Society for the Study of Amphibians and Reptiles.

  19. Eco–geographical characterization of aquatic microhabitats used by amphibians in the Mediterranean Basin

    Directory of Open Access Journals (Sweden)

    Benítez, M.

    2017-01-01

    Full Text Available Small freshwater ecosystems, whether natural or artificial origin, are aquatic microhabitats for many species and are particularly important in the Mediterranean region. This study characterizes the aquatic microhabitats suitable for amphibian reproduction in the Andalusian Mediterranean Basin and identifies the environmental and geographical features that determine the presence of different amphibian species in these water bodies. Geographical and environmental favourability models were performed to determine the relationship between characteristics of the microhabitats and species presence. The characteristics analysed were geographical location, external environment (climate and topography, surrounding conditions (connectivity and conservation, type of water body, water conditions, and water dimensions. Microhabitats located in the western and central part of the study area were geographically favourable for most species. In descending order, the most common environmental factors characterizing the microhabitats were typology, surrounding conditions, water condition, external environment and size of the water body. The most common variables in the models were the connectivity between water bodies and old wells, a frequent type of microhabitat in areas of traditional cultures. Management plans should take these results into account in efforts to preserve these habitats for wildlife and especially amphibians.

  20. Microhabitat use, population densities, and size distributions of sulfur cave-dwelling Poecilia mexicana.

    Science.gov (United States)

    Jourdan, Jonas; Bierbach, David; Riesch, Rüdiger; Schießl, Angela; Wigh, Adriana; Arias-Rodriguez, Lenin; Indy, Jeane Rimber; Klaus, Sebastian; Zimmer, Claudia; Plath, Martin

    2014-01-01

    The Cueva del Azufre in Tabasco, Mexico, is a nutrient-rich cave and its inhabitants need to cope with high levels of dissolved hydrogen sulfide and extreme hypoxia. One of the successful colonizers of this cave is the poeciliid fish Poecilia mexicana, which has received considerable attention as a model organism to examine evolutionary adaptations to extreme environmental conditions. Nonetheless, basic ecological data on the endemic cave molly population are still missing; here we aim to provide data on population densities, size class compositions and use of different microhabitats. We found high overall densities in the cave and highest densities at the middle part of the cave with more than 200 individuals per square meter. These sites have lower H2S concentrations compared to the inner parts where most large sulfide sources are located, but they are annually exposed to a religious harvesting ceremony of local Zoque people called La Pesca. We found a marked shift in size/age compositions towards an overabundance of smaller, juvenile fish at those sites. We discuss these findings in relation to several environmental gradients within the cave (i.e., differences in toxicity and lighting conditions), but we also tentatively argue that the annual fish harvest during a religious ceremony (La Pesca) locally diminishes competition (and possibly, cannibalism by large adults), which is followed by a phase of overcompensation of fish densities.

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

    Science.gov (United States)

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

    2017-05-20

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

  2. Device Optimization and Transient Electroluminescence Studies of Organic light Emitting Devices

    International Nuclear Information System (INIS)

    Lijuan Zou

    2003-01-01

    Organic light emitting devices (OLEDs) are among the most promising for flat panel display technologies. They are light, bright, flexible, and cost effective. And while they are emerging in commercial product, their low power efficiency and long-term degradation are still challenging. The aim of this work was to investigate their device physics and improve their performance. Violet and blue OLEDs were studied. The devices were prepared by thermal vapor deposition in high vacuum. The combinatorial method was employed in device preparation. Both continuous wave and transient electroluminescence (EL) were studied. A new efficient and intense UV-violet light emitting device was developed. At a current density of 10 mA/cm 2 , the optimal radiance R could reach 0.38 mW/cm 2 , and the quantum efficiency was 1.25%. using the delayed EL technique, electron mobilities in DPVBi and CBP were determined to be ∼ 10 -5 cm 2 /Vs and ∼ 10 -4 cm 2 /Vs, respectively. Overshoot effects in the transient El of blue light emitting devices were also observed and studied. This effect was attributed to the charge accumulation at the organic/organic and organic/cathode interfaces

  3. Spatial layout optimization design of multi-type LEDs lighting source based on photoelectrothermal coupling theory

    Science.gov (United States)

    Xue, Lingyun; Li, Guang; Chen, Qingguang; Rao, Huanle; Xu, Ping

    2018-03-01

    Multiple LED-based spectral synthesis technology has been widely used in the fields of solar simulator, color mixing, and artificial lighting of plant factory and so on. Generally, amounts of LEDs are spatially arranged with compact layout to obtain the high power density output. Mutual thermal spreading among LEDs will produce the coupled thermal effect which will additionally increase the junction temperature of LED. Affected by the Photoelectric thermal coupling effect of LED, the spectrum of LED will shift and luminous efficiency will decrease. Correspondingly, the spectral synthesis result will mismatch. Therefore, thermal management of LED spatial layout plays an important role for multi-LEDs light source system. In the paper, the thermal dissipation network topology model considering the mutual thermal spreading effect among the LEDs is proposed for multi-LEDs system with various types of power. The junction temperature increment cased by the thermal coupling has the great relation with the spatial arrangement. To minimize the thermal coupling effect, an optimized method of LED spatial layout for the specific light source structure is presented and analyzed. The results showed that layout of LED with high-power are arranged in the corner and low-power in the center. Finally, according to this method, it is convenient to determine the spatial layout of LEDs in a system having any kind of light source structure, and has the advantages of being universally applicable to facilitate adjustment.

  4. Device Optimization and Transient Electroluminescence Studies of Organic light Emitting Devices

    Energy Technology Data Exchange (ETDEWEB)

    Lijuan Zou

    2003-08-05

    Organic light emitting devices (OLEDs) are among the most promising for flat panel display technologies. They are light, bright, flexible, and cost effective. And while they are emerging in commercial product, their low power efficiency and long-term degradation are still challenging. The aim of this work was to investigate their device physics and improve their performance. Violet and blue OLEDs were studied. The devices were prepared by thermal vapor deposition in high vacuum. The combinatorial method was employed in device preparation. Both continuous wave and transient electroluminescence (EL) were studied. A new efficient and intense UV-violet light emitting device was developed. At a current density of 10 mA/cm{sup 2}, the optimal radiance R could reach 0.38 mW/cm{sup 2}, and the quantum efficiency was 1.25%. using the delayed EL technique, electron mobilities in DPVBi and CBP were determined to be {approx} 10{sup -5} cm{sup 2}/Vs and {approx} 10{sup -4} cm{sup 2}/Vs, respectively. Overshoot effects in the transient El of blue light emitting devices were also observed and studied. This effect was attributed to the charge accumulation at the organic/organic and organic/cathode interfaces.

  5. Microhabitat choice in island lizards enhances camouflage against avian predators.

    Science.gov (United States)

    Marshall, Kate L A; Philpot, Kate E; Stevens, Martin

    2016-01-25

    Camouflage can often be enhanced by genetic adaptation to different local environments. However, it is less clear how individual behaviour improves camouflage effectiveness. We investigated whether individual Aegean wall lizards (Podarcis erhardii) inhabiting different islands rest on backgrounds that improve camouflage against avian predators. In free-ranging lizards, we found that dorsal regions were better matched against chosen backgrounds than against other backgrounds on the same island. This suggests that P. erhardii make background choices that heighten individual-specific concealment. In achromatic camouflage, this effect was more evident in females and was less distinct in an island population with lower predation risk. This suggests that behavioural enhancement of camouflage may be more important in females than in sexually competing males and related to predation risk. However, in an arena experiment, lizards did not choose the background that improved camouflage, most likely due to the artificial conditions. Overall, our results provide evidence that behavioural preferences for substrates can enhance individual camouflage of lizards in natural microhabitats, and that such adaptations may be sexually dimorphic and dependent on local environments. This research emphasizes the importance of considering links between ecology, behaviour, and appearance in studies of intraspecific colour variation and local adaptation.

  6. STANDALONE PHOTOVOLTAIC SYSTEMS SIZING OPTIMIZATION USING DESIGN SPACE APPROACH: CASE STUDY FOR RESIDENTIAL LIGHTING LOAD

    Directory of Open Access Journals (Sweden)

    D. F. AL RIZA

    2015-07-01

    Full Text Available This paper presents a sizing optimization methodology of panel and battery capacity in a standalone photovoltaic system with lighting load. Performance of the system is identified by performing Loss of Power Supply Probability (LPSP calculation. Input data used for the calculation is the daily weather data and system components parameters. Capital Cost and Life Cycle Cost (LCC is calculated as optimization parameters. Design space for optimum system configuration is identified based on a given LPSP value, Capital Cost and Life Cycle Cost. Excess energy value is used as an over-design indicator in the design space. An economic analysis, including cost of the energy and payback period, for selected configurations are also studied.

  7. The Combined Multi-objective Optimization Design for a Light Guide Rod

    International Nuclear Information System (INIS)

    Yang, Yu-Sen; Fung, Rong-Fong; Shih, Chun-Yao; Chien, Hong-Yao

    2013-01-01

    The light guide rod (LGR) has been popularly used for the vehicles, and the automobile lamp industries need mass production to match this trend. This paper aims to develop a systemic way to find the best parameters' combination for the LGR, and the parameters are usually restricted to some levels and random values. In this paper, the LGR example with two optical performances of illuminance flux and uniformity is to be optimized by use of the real-coded genetic algorithm (RGA) and grey relational analysis (GRA). The illuminance flux and uniformity of the best parameters' combination are obtained and compared with the initial set. Comparisons with Taguchi-Grey can improve 5% of gain and comparisons with Pareto genetic algorithm (PaGA) can improve 1.7% of gain. The combined multi-objective optimization can saving 7% time and it is found that the new proposed method has positive gains in performances.

  8. Supercontinuum optimization for dual-soliton based light sources using genetic algorithms in a grid platform.

    Science.gov (United States)

    Arteaga-Sierra, F R; Milián, C; Torres-Gómez, I; Torres-Cisneros, M; Moltó, G; Ferrando, A

    2014-09-22

    We present a numerical strategy to design fiber based dual pulse light sources exhibiting two predefined spectral peaks in the anomalous group velocity dispersion regime. The frequency conversion is based on the soliton fission and soliton self-frequency shift occurring during supercontinuum generation. The optimization process is carried out by a genetic algorithm that provides the optimum input pulse parameters: wavelength, temporal width and peak power. This algorithm is implemented in a Grid platform in order to take advantage of distributed computing. These results are useful for optical coherence tomography applications where bell-shaped pulses located in the second near-infrared window are needed.

  9. Optimization of {sup 6}LiF:ZnS(Ag) Scintillator Light Yield Using Geant4

    Energy Technology Data Exchange (ETDEWEB)

    Yehuda-Zada, Y. [Nuclear Research Center Negev, Beer-Sheva (Israel); Ben-Gurion University (Israel); Pritchard, K.; Ziegler, J.B.; Cooksey, C.; Siebein, K. [National Institute of Standards and Technology, Gaithersburg, Maryland (United States); Jackson, M.; Hurlbut, C. [Eljen Technology, Sweetwater Texas (United States); Kadmon, Y.; Cohen, Y.; Maliszewskyj, N.C. [Nuclear Research Center Negev, Beer-Sheva (Israel); Ibberson, R.M.; Majkrzak, C.F. [National Institute of Standards and Technology, Gaithersburg, Maryland (United States); Orion, Y. [Ben-Gurion University (Israel); Osovizky, A. [National Institute of Standards and Technology, Gaithersburg, Maryland (United States); Rotem Industries Ltd, Rotem Industrial Park (Israel); University of Maryland (United States)

    2015-07-01

    Neutrons provide an effective tool to probe materials structure. Neutron diffraction is a method to determine the atomic and magnetic structure of a material based on neutron scattering. By this method a collimated incident beam of thermal neutrons heat the examined sample and based on the obtained diffraction pattern information on the structure of the material is provided. Research for developing a novel cold neutron detector for Chromatic Analysis Neutron Diffractometer Or Reflectometer (CANDOR) is underway at the NIST center for neutron research. The system unique design is aimed to provide over ten times fold faster analysis of materials than conventional system. In order to achieve the fast analysis a large number of neutron detectors is required. A key design constraint for this detector is the thickness of the neutron sensitive element. This is met using {sup 6}LiF:ZnS(Ag) scintillation material with embedded wavelength shifting (WLS) fibers conducting scintillation light to silicon photomultiplier photo-sensors. The detector sensitivity is determined by both the neutron capture probability ({sup 6}Li density) and the detectable light output produced by the ZnS(Ag) ionization, the latter of which is hindered by the fluorescence absorption of the scintillation light by the ZnS. Tradeoffs between the neutron capture probability, stimulated light production and light attenuation for determining the optimal stoichiometry of the {sup 6}LiF and ZnS(Ag) as well as the volume ratio of scintillator and fiber. Simulations performed using the GEANT4 Monte Carlo package were made in order to optimize the detector design. GEANT4 enables the investigation of the neutron interaction with the detector, the ionization process and the light transfer process following the nuclear process. The series of conversions required for this detector were modelled: - A cold neutron enters the sensor and is captured by {sup 6}Li in the scintillator mixture ({sup 6}Li (n,α) {sup 3}H

  10. An optimized power conversion system concept of the integral, inherently-safe light water reactor

    International Nuclear Information System (INIS)

    Memmott, Matthew J.; Wilding, Paul R.; Petrovic, Bojan

    2017-01-01

    Highlights: • Three power conversion systems (PCS) for the I"2S-LWR are presented. • An optimization analyses was performed to evaluate these PCS alternatives. • The ideal PCS consists of 5 turbines, and obtains an overall efficiency of 35.7%. - Abstract: The integral, inherently safe light water reactor (I"2S-LWR) has been developed to significantly enhance passive safety capabilities while maintaining cost competitiveness relative to the current light water reactor (LWR) fleet. The compact heat exchangers of the I"2S-LWR preclude boiling of the secondary fluid, which decreases the probability of heat exchanger failure, but this requires the addition of a flash drum, which negatively affects the overall plant thermodynamic efficiency. A state of the art Rankine cycle is proposed for the I"2S-LWR to increase the thermodynamic efficiency by utilizing a flash drum with optimized operational parameters. In presenting this option for power conversion in the I"2S-LWR power plant, the key metric used in rating the performance is the overall net thermodynamic efficiency of the cycle. In evaluating the flash-Rankine cycle, three basic industrial concepts are evaluated, one without an intermediate pressure turbine, one with an intermediate turbine and one reheat stream, and one with an intermediate turbine and two reheat streams. For each configuration, a single-path multi-variable optimization is undertaken to maximize the thermal efficiency. The third configuration with an intermediate turbine and 2 reheat streams is the most effective concept, with an optimized efficiency of 35.7%.

  11. Lighting.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration.

    1992-09-01

    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.

  12. The influence of tree age and microhabitat quality on the occurrence of crustose lichens associated with old oaks

    OpenAIRE

    Ranius, Thomas; Johansson, Per; Berg, Niclas; Niklasson, Mats

    2008-01-01

    Questions: How do tree age, microhabitat characteristics and epiphytic competitors affect the occurrence of crustose lichens associated with old oaks? How do microhabitat characteristics and microclimate affect the cover of competitors (bryophytes and macrolichens)? How do microhabitat characteristics cor¬relate with microclimatic variables? Location: Southeast Sweden. Methods: Eight crustose lichen species were surveyed on 165 Quercus robur trees, 17-478 years old, at three study sit...

  13. Lighting

    Data.gov (United States)

    Federal Laboratory Consortium — Lighting Systems Test Facilities aid research that improves the energy efficiency of lighting systems. • Gonio-Photometer: Measures illuminance from each portion of...

  14. Optimal metering plan for measurement and verification on a lighting case study

    International Nuclear Information System (INIS)

    Ye, Xianming; Xia, Xiaohua

    2016-01-01

    M&V (Measurement and Verification) has become an indispensable process in various incentive EEDSM (energy efficiency and demand side management) programmes to accurately and reliably measure and verify the project performance in terms of energy and/or cost savings. Due to the uncertain nature of the unmeasurable savings, there is an inherent trade-off between the M&V accuracy and M&V cost. In order to achieve the required M&V accuracy cost-effectively, we propose a combined spatial and longitudinal MCM (metering cost minimisation) model to assist the design of optimal M&V metering plans, which minimises the metering cost whilst satisfying the required measurement and sampling accuracy of M&V. The objective function of the proposed MCM model is the M&V metering cost that covers the procurement, installation and maintenance of the metering system whereas the M&V accuracy requirements are formulated as the constraints. Optimal solutions to the proposed MCM model offer useful information in designing the optimal M&V metering plan. The advantages of the proposed MCM model are demonstrated by a case study of an EE lighting retrofit project and the model is widely applicable to other M&V lighting projects with different population sizes and sampling accuracy requirements. - Highlights: • A combined spatial and longitudinal optimisation model is proposed to reduce M&V cost. • The combined optimisation model handles M&V sampling uncertainty cost-effectively. • The model exhibits a better performance than the separate spatial or longitudinal models. • The required 90/10 criterion sampling accuracy is satisfied for each M&V report.

  15. Optimization and characterization of condensation nucleation light scattering detection coupled with supercritical fluid chromatography

    Science.gov (United States)

    Yang, Shaoping

    This dissertation is an investigation of two aspects of coupling condensation nucleation light scattering detection (CNLSD) with supercritical fluid chromatography (SFC). In the first part, it was demonstrated that CNLSD was compatible with packed column SFC using either pure CO2 or organic solvent modified CO2 as mobile phases. Factors which were expected to affect the interface between SFC and CNLSD were optimized for the detector to reach low detection limits. With SFC using pure CO2 as mobile phase, the detection limit of CNLSD with SFC was observed to be at low nanogram levels, which was at the same level of flame ionization detection (FID) coupled with SFC. For SFC using modified CO2 as mobile phase, detection limits at the picogram level were observed for CNLSD at optimal conditions, which were at least ten times lower than those reached by evaporative light scattering detection. In the second part, particle size distributions of aerosols produced from rapid expansion of supercritical solutions were measured with a scanning mobility particle sizer. The effect of the factors, which were investigated in the first part for their effects on signal intensities and signal to noise ratios (S/N), on particle size distributions (PSDs) of both analyte and background were investigated. Whenever possible, both particle sizes and particle number obtained from PSDs were used to explain the optimization results. In general, PSD data support the observations made in the first part. The detection limits of CNLSD obtained were much higher than predicted. PSDs did not provide direct explanation of this problem. The amount of analyte deposited in the transport tubing, evaporated to gas phase, and condensed to form particles was determined experimentally. Almost no analyte was found in the gas phase. Less than 3% was found in the particle forms. The vast majority of analyte was lost in the transport tubing, especially in the short distance after supercritical fluid expansion. A

  16. Benthic foraminiferal Mn / Ca ratios reflect microhabitat preferences

    Science.gov (United States)

    Koho, Karoliina A.; de Nooijer, Lennart J.; Fontanier, Christophe; Toyofuku, Takashi; Oguri, Kazumasa; Kitazato, Hiroshi; Reichart, Gert-Jan

    2017-06-01

    The Mn / Ca of calcium carbonate tests of living (rose-Bengal-stained) benthic foraminifera (Elphidium batialis, Uvigerina spp., Bolivina spissa, Nonionellina labradorica and Chilostomellina fimbriata) were determined in relation to pore water manganese (Mn) concentrations for the first time along a bottom water oxygen gradient across the continental slope along the NE Japan margin (western Pacific). The local bottom water oxygen (BWO) gradient differs from previous field study sites focusing on foraminiferal Mn / Ca and redox chemistry, therefore allowing further resolution of previously observed trends. The Mn / Ca ratios were analysed using laser ablation inductively coupled plasma-mass spectrometer (ICP-MS), allowing single-chamber determination of Mn / Ca. The incorporation of Mn into the carbonate tests reflects environmental conditions and is not influenced by ontogeny. The inter-species variability in Mn / Ca reflected foraminiferal in-sediment habitat preferences and associated pore water chemistry but also showed large interspecific differences in Mn partitioning. At each station, Mn / Ca ratios were always lower in the shallow infaunal E. batialis, occupying relatively oxygenated sediments, compared to intermediate infaunal species, Uvigerina spp. and B. spissa, which were typically found at greater depth, under more reducing conditions. The highest Mn / Ca was always recorded by the deep infaunal species N. labradorica and C. fimbriata. Our results suggest that although partitioning differs, Mn / Ca ratios in the intermediate infaunal taxa are promising tools for palaeoceanographic reconstructions as their microhabitat exposes them to higher variability in pore water Mn, thereby making them relatively sensitive recorders of redox conditions and/or bottom water oxygenation.

  17. Benthic foraminiferal Mn / Ca ratios reflect microhabitat preferences

    Directory of Open Access Journals (Sweden)

    K. A. Koho

    2017-06-01

    Full Text Available The Mn / Ca of calcium carbonate tests of living (rose-Bengal-stained benthic foraminifera (Elphidium batialis, Uvigerina spp., Bolivina spissa, Nonionellina labradorica and Chilostomellina fimbriata were determined in relation to pore water manganese (Mn concentrations for the first time along a bottom water oxygen gradient across the continental slope along the NE Japan margin (western Pacific. The local bottom water oxygen (BWO gradient differs from previous field study sites focusing on foraminiferal Mn / Ca and redox chemistry, therefore allowing further resolution of previously observed trends. The Mn / Ca ratios were analysed using laser ablation inductively coupled plasma-mass spectrometer (ICP-MS, allowing single-chamber determination of Mn / Ca. The incorporation of Mn into the carbonate tests reflects environmental conditions and is not influenced by ontogeny. The inter-species variability in Mn / Ca reflected foraminiferal in-sediment habitat preferences and associated pore water chemistry but also showed large interspecific differences in Mn partitioning. At each station, Mn / Ca ratios were always lower in the shallow infaunal E. batialis, occupying relatively oxygenated sediments, compared to intermediate infaunal species, Uvigerina spp. and B. spissa, which were typically found at greater depth, under more reducing conditions. The highest Mn / Ca was always recorded by the deep infaunal species N. labradorica and C. fimbriata. Our results suggest that although partitioning differs, Mn / Ca ratios in the intermediate infaunal taxa are promising tools for palaeoceanographic reconstructions as their microhabitat exposes them to higher variability in pore water Mn, thereby making them relatively sensitive recorders of redox conditions and/or bottom water oxygenation.

  18. Optimizing preventive maintenance policy: A data-driven application for a light rail braking system.

    Science.gov (United States)

    Corman, Francesco; Kraijema, Sander; Godjevac, Milinko; Lodewijks, Gabriel

    2017-10-01

    This article presents a case study determining the optimal preventive maintenance policy for a light rail rolling stock system in terms of reliability, availability, and maintenance costs. The maintenance policy defines one of the three predefined preventive maintenance actions at fixed time-based intervals for each of the subsystems of the braking system. Based on work, maintenance, and failure data, we model the reliability degradation of the system and its subsystems under the current maintenance policy by a Weibull distribution. We then analytically determine the relation between reliability, availability, and maintenance costs. We validate the model against recorded reliability and availability and get further insights by a dedicated sensitivity analysis. The model is then used in a sequential optimization framework determining preventive maintenance intervals to improve on the key performance indicators. We show the potential of data-driven modelling to determine optimal maintenance policy: same system availability and reliability can be achieved with 30% maintenance cost reduction, by prolonging the intervals and re-grouping maintenance actions.

  19. Optimization of operating conditions in oxidation of dibenzothiophene in the light hydrocarbon model

    Directory of Open Access Journals (Sweden)

    Akbari Azam

    2014-01-01

    Full Text Available In this research, the effects of process variables on the efficiency and mechanism of dibenzothiophene oxidation in formicacid/H2O2 system for deep desulfurization of a light hydrocarbon model were systematically studied by statistical modelling and optimization using response surface methodology and implementing the central composite design. A quadratic regression model was developed to predict the yield of sulfur oxidation as the model response. The model indicated that temperature was the most significant effective factor and suggested an important interaction between temperature and H2O2/sulfur ratio; at temperatures above 56°C, more excess oxidant was necessary because of instability of active peroxo intermediates and loss of H2O2 due to thermal decomposition. In contrast, the water hindrance effect of H2O2 aqueous solution in desulfurization progress was more significant at temperatures bellow 56°C. In the optimization process, minimizing H2O2/sulfur ratio and catalyst consumption for maximum yield of desulfurization was economically considerable. The optimal condition was obtained at temperature of 57 °C, H2O2/sulfur ratio of 2.5 mol/mol and catalyst dosage of 0.82 mL in 50 mL solution of DBT in n-hexane leading to a maximum oxidation yield of 95% after 1 hour reaction. Good agreement between predicted and experimental results (less than 4% error was found.

  20. Optimization of 6LiF:ZnS(Ag) scintillator light yield using GEANT4

    Science.gov (United States)

    Yehuda-Zada, Y.; Pritchard, K.; Ziegler, J. B.; Cooksey, C.; Siebein, K.; Jackson, M.; Hurlbut, C.; Kadmon, Y.; Cohen, Y.; Ibberson, R. M.; Majkrzak, C. F.; Maliszewskyj, N. C.; Orion, I.; Osovizky, A.

    2018-06-01

    A new cold neutron detector has been developed at the NIST Center for Neutron Research (NCNR) for the CANDoR (Chromatic Analysis Neutron Diffractometer or Reflectometer) project. Geometric and performance constraints dictate that this detector be exceptionally thin (∼ 2 mm). For this reason, the design of the detector consists of a 6LiF:ZnS(Ag) scintillator with embedded wavelength shifting (WLS) fibers. We used the GEANT4 package to simulate neutron capture and light transport in the detector to optimize the composition and arrangement of materials to satisfy the competing requirements of high neutron capture probability and light production and transport. In the process, we have developed a method for predicting light collection and total neutron detection efficiency for different detector configurations. The simulation was performed by adjusting crucial parameters such as the scintillator stoichiometry, light yield, component grain size, WLS fiber geometry, and reflectors at the outside edges of the scintillator volume. Three different detector configurations were fabricated and their test results were correlated with the simulations. Through this correlation we have managed to find a common photon threshold for the different detector configurations which was then used to simulate and predict the efficiencies for many other detector configurations. New detectors that have been fabricated based on simulation results yielding the desired sensitivity of 90% for 3.27 meV (5 Å) cold neutrons. The simulation has proven to be a useful tool by dramatically reducing the development period and the required number of detector prototypes. It can be used to test new designs with different thicknesses and different target neutron energies.

  1. Light

    DEFF Research Database (Denmark)

    Prescott, N.B.; Kristensen, Helle Halkjær; Wathes, C.M.

    2004-01-01

    This chapter presents the effect of artificial light environments (light levels, colour, photoperiod and flicker) on the welfare of broilers in terms of vision, behaviour, lameness and mortality......This chapter presents the effect of artificial light environments (light levels, colour, photoperiod and flicker) on the welfare of broilers in terms of vision, behaviour, lameness and mortality...

  2. Optimization of signal-to-noise ratio for wireless light-emitting diode communication in modern lighting layouts

    Science.gov (United States)

    Azizan, Luqman A.; Ab-Rahman, Mohammad S.; Hassan, Mazen R.; Bakar, A. Ashrif A.; Nordin, Rosdiadee

    2014-04-01

    White light-emitting diodes (LEDs) are predicted to be widely used in domestic applications in the future, because they are becoming widespread in commercial lighting applications. The ability of LEDs to be modulated at high speeds offers the possibility of using them as sources for communication instead of illumination. The growing interest in using these devices for both illumination and communication requires attention to combine this technology with modern lighting layouts. A dual-function system is applied to three models of modern lighting layouts: the hybrid corner lighting layout (HCLL), the hybrid wall lighting layout (HWLL), and the hybrid edge lighting layout (HELL). Based on the analysis, the relationship between the space adversity and the signal-to-noise ratio (SNR) performance is demonstrated for each model. The key factor that affects the SNR performance of visible light communication is the reliance on the design parameter that is related to the number and position of LED lights. The model of HWLL is chosen as the best layout, since 61% of the office area is considered as an excellent communication area and the difference between the area classification, Δp, is 22%. Thus, this system is applicable to modern lighting layouts.

  3. Microhabitat of small mammals at ground and understorey levels in a deciduous, southern Atlantic forest.

    Science.gov (United States)

    Melo, Geruza L; Miotto, Barbara; Peres, Brisa; Cáceres, Nilton C

    2013-01-01

    Each animal species selects specific microhabitats for protection, foraging, or micro-climate. To understand the distribution patterns of small mammals on the ground and in the understorey, we investigated the use of microhabitats by small mammals in a deciduous forest of southern Brazil. Ten trap stations with seven capture points were used to sample the following microhabitats: liana, fallen log, ground litter, terrestrial ferns, simple-trunk tree, forked tree, and Piper sp. shrubs. Seven field phases were conducted, each for eight consecutive days, from September 2006 through January 2008. Four species of rodents (Akodon montensis, Sooretamys angouya, Oligoryzomys nigripes and Mus musculus) and two species of marsupials (Didelphis albiventris and Gracilinanus microtarsus) were captured. Captured species presented significant differences on their microhabitat use (ANOVA, p = 0.003), particularly between ground and understorey sites. Akodon montensis selected positively terrestrial ferns and trunks, S. angouya selected lianas, D. albiventris selected fallen trunks and Piper sp., and G. microtarsus choose tree trunks and lianas. We demonstrated that the local small-mammal assemblage does select microhabitats, with different types of associations between species and habitats. Besides, there is a strong evidence of habitat selection in order to diminish predation.

  4. Food Offer Inside Agroecosystem Soils as an Ecological Factor for Settling Microhabitats by Soil Saprophagous Mites

    Directory of Open Access Journals (Sweden)

    Jaroslav Smrž

    2015-01-01

    Full Text Available Mainly abiotic factors have been considered in examining soil fauna invasion or settlement. The role of soil animals communities was not considered. Our hypothesis, indeed, can be formulated: the structure and feeding habits of the soil animals community is not able to play some role in the soil rating. Localities, however, can be fragmented into microhabitats. We studied cultivated field and adjacent unploughed areas (so-called baulks, using the common Berlese–Tullgren apparatus for community structure studies followed by histological tests of food consumed by community members. We selected a group of oribatid mites, which are frequent and abundant. In the studied localities and their microhabitats, three groups of oribatid mites can be reported. First – ubiquitous species a second – migrants from the less-impacted to more-impacted microhabitats and third – specialists sensitive to severe environmental conditions in more-impacted microhabitat. They consequently live only in the less-severe, less-impacted unploughed soils and never migrate from these microhabitats. Their grazed and digested food is more diversified, and they included more feeding specialists.

  5. Microhabitat and Climatic Niche Change Explain Patterns of Diversification among Frog Families.

    Science.gov (United States)

    Moen, Daniel S; Wiens, John J

    2017-07-01

    A major goal of ecology and evolutionary biology is to explain patterns of species richness among clades. Differences in rates of net diversification (speciation minus extinction over time) may often explain these patterns, but the factors that drive variation in diversification rates remain uncertain. Three important candidates are climatic niche position (e.g., whether clades are primarily temperate or tropical), rates of climatic niche change among species within clades, and microhabitat (e.g., aquatic, terrestrial, arboreal). The first two factors have been tested separately in several studies, but the relative importance of all three is largely unknown. Here we explore the correlates of diversification among families of frogs, which collectively represent ∼88% of amphibian species. We assemble and analyze data on phylogeny, climate, and microhabitat for thousands of species. We find that the best-fitting phylogenetic multiple regression model includes all three types of variables: microhabitat, rates of climatic niche change, and climatic niche position. This model explains 67% of the variation in diversification rates among frog families, with arboreal microhabitat explaining ∼31%, niche rates ∼25%, and climatic niche position ∼11%. Surprisingly, we show that microhabitat can have a much stronger influence on diversification than climatic niche position or rates of climatic niche change.

  6. Automated procedure for selection of optimal refueling policies for light water reactors

    International Nuclear Information System (INIS)

    Lin, B.I.; Zolotar, B.; Weisman, J.

    1979-01-01

    An automated procedure determining a minimum cost refueling policy has been developed for light water reactors. The procedure is an extension of the equilibrium core approach previously devised for pressurized water reactors (PWRs). Use of 1 1/2-group theory has improved the accuracy of the nuclear model and eliminated tedious fitting of albedos. A simple heuristic algorithm for locating a good starting policy has materially reduced PWR computing time. Inclusion of void effects and use of the Haling principle for axial flux calculations extended the nuclear model to boiling water reactors (BWRs). A good initial estimate of the refueling policy is obtained by recognizing that a nearly uniform distribution of reactivity provides low-power peaking. The initial estimate is improved upon by interchanging groups of four assemblies and is subsequently refined by interchanging individual assemblies. The method yields very favorable results, is simpler than previously proposed BWR fuel optimization schemes, and retains power cost as the objective function

  7. S/O modeling technique for optimal containment of light hydrocarbons in contaminated unconfined aquifers

    International Nuclear Information System (INIS)

    Cooper, G.S. Jr.; Kaluarachchi, J.J.; Peralta, R.C.

    1993-01-01

    An innovative approach is presented to minimize pumping for immobilizing a floating plume of a light non-aqueous phase liquid (LNAPL). The best pumping strategy is determined to contain the free oil product and provide for gradient control of the water table. This approach combined detailed simulation, statistical analysis, and optimization. This modeling technique uses regression equations that describe system response to variable pumping stimuli. The regression equations were developed from analysis of systematically performed simulations of multiphase flow in an areal region of an unconfined aquifer. Simulations were performed using ARMOS, a finite element model. ARMOS can be used to simulate a spill, leakage from subsurface storage facilities and recovery of hydrocarbons from trenches or pumping wells to design remediation schemes

  8. Preparation and performance optimization of TPBISi green-light organic luminescent material devices

    Directory of Open Access Journals (Sweden)

    Zheng Huajing

    2017-01-01

    Full Text Available The Study analyzed and tested the absorption spectrum, photoluminescence spectrum, and device’s electroluminescence spectrum of a new silole material. The device with Silol as an emitting layer, emitted green-light whose structure is ITO/NPB/2,2,3,3-tetraphenyl-4,4-bisthienylsilole(TPBTSi/Alq3/Mg: A by improvement of preparation technology and optimization of thin film. It reaches the maximum luminescence of 11290.2 cd/m2, the maximum luminous efficiency of 0.84 lm/W, luminescence spectrum of 516 nm, chromaticity diagram CIE coordinate of(0.275, 0.4568 when voltage is 15V. All of the above is the green characteristic spectrum of TPBTSi.

  9. Spatially Explicit Estimation of Optimal Light Use Efficiency for Improved Satellite Data Driven Ecosystem Productivity Modeling

    Science.gov (United States)

    Madani, N.; Kimball, J. S.; Running, S. W.

    2014-12-01

    Remote sensing based light use efficiency (LUE) models, including the MODIS (MODerate resolution Imaging Spectroradiometer) MOD17 algorithm are commonly used for regional estimation and monitoring of vegetation gross primary production (GPP) and photosynthetic carbon (CO2) uptake. A common model assumption is that plants in a biome matrix operate at their photosynthetic capacity under optimal climatic conditions. A prescribed biome maximum light use efficiency parameter defines the maximum photosynthetic carbon conversion rate under prevailing climate conditions and is a large source of model uncertainty. Here, we used tower (FLUXNET) eddy covariance measurement based carbon flux data for estimating optimal LUE (LUEopt) over a North American domain. LUEopt was first estimated using tower observed daily carbon fluxes, meteorology and satellite (MODIS) observed fraction of photosynthetically active radiation (FPAR). LUEopt was then spatially interpolated over the domain using empirical models derived from independent geospatial data including global plant traits, surface soil moisture, terrain aspect, land cover type and percent tree cover. The derived LUEopt maps were then used as primary inputs to the MOD17 LUE algorithm for regional GPP estimation; these results were evaluated against tower observations and alternate MOD17 GPP estimates determined using Biome-specific LUEopt constants. Estimated LUEopt shows large spatial variability within and among different land cover classes indicated from a sparse North American tower network. Leaf nitrogen content and soil moisture are two important factors explaining LUEopt spatial variability. GPP estimated from spatially explicit LUEopt inputs shows significantly improved model accuracy against independent tower observations (R2 = 0.76; Mean RMSE plant trait information can explain spatial heterogeneity in LUEopt, leading to improved GPP estimates from satellite based LUE models.

  10. Water trophicity of Utricularia microhabitats identlfied by means of SOFM as a tool in ecological modeling

    Directory of Open Access Journals (Sweden)

    Piotr Kosiba

    2011-01-01

    Full Text Available The study objects were 48 microhabitats of five Utricularia species in Lower and Upper Silesia (POLAND. The aim of the paper was to focus on application of the Self-Organizing Feature Map in assessment of water trophicity in Utricularia microhabitats, and to describe how SOFM can be used for the study of ecological subjects. This method was compared with the hierarchical tree plot of cluster analysis to check whether this techniques give similar results. In effect, both topological map of SOFM and dendrogram of cluster analysis show differences between Utricularia species microhabitats in respect of water quality, from eutrophic for U. vulgaris to dystrophic for U. minor and U. intermedia. The used methods give similar results and constitute a validation of the SOFM method in this type of studies.

  11. Optimized treatment conditions for textile wastewater reuse using photocatalytic processes under UV and visible light sources.

    Science.gov (United States)

    Starling, Maria Clara V M; Castro, Luiz Augusto S; Marcelino, Rafaela B P; Leão, Mônica M D; Amorim, Camila C

    2017-03-01

    In this study, photo-Fenton systems using visible light sources with iron and ferrioxalate were tested for the DOC degradation and decolorization of textile wastewater. Textile wastewaters originated after the dyeing stage of dark-colored tissue in the textile industry, and the optimization of treatment processes was studied to produce water suitable for reuse. Dissolved organic carbon, absorbance, turbidity, anionic concentrations, carboxylic acids, and preliminary cost analysis were performed for the proposed treatments. Conventional photo-Fenton process achieved near 99 % DOC degradation rates and complete absorbance removal, and no carboxylic acids were found as products of degradation. Ferrioxalate photo-Fenton system achieved 82 % of DOC degradation and showed complete absorbance removal, and oxalic acid has been detected through HPLC analysis in the treated sample. In contrast, photo-peroxidation with UV light was proved effective only for absorbance removal, with DOC degradation efficiency near 50 %. Treated wastewater was compared with reclaimed water and had a similar quality, indicating that these processes can be effectively applied for textile wastewater reuse. The results of the preliminary cost analysis indicated costs of 0.91 to 1.07 US$ m -3 for the conventional and ferrioxalate photo-Fenton systems, respectively. Graphical Abstract ᅟ.

  12. Optimal nitrogen and phosphorus codoping carbon dots towards white light-emitting device

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Feng; Wang, Yaling; Miao, Yanqin; Yang, Yongzhen, E-mail: yyztyut@126.com, E-mail: liuxuguang@tyut.edu.cn [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Ministry of Education, Taiyuan 030024 (China); Research Center on Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); He, Yuheng; Liu, Xuguang, E-mail: yyztyut@126.com, E-mail: liuxuguang@tyut.edu.cn [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Ministry of Education, Taiyuan 030024 (China); College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China)

    2016-08-22

    Through a one-step fast microwave-assisted approach, nitrogen and phosphorus co-doped carbon dots (N,P-CDs) were synthesized using ammonium citrate (AC) as a carbon source and phosphates as additive reagent. Under the condition of an optimal reaction time of 140 s, the influence of additive with different N and P content on fluorescent performance of N,P-CDs was further explored. It was concluded that high nitrogen content and moderate phosphorus content are necessary for obtaining high quantum yield (QY) N,P-CDs, among which the TAP-CDs (CDs synthesized using ammonium phosphate as additive reagent) show high quantum yield (QY) of 62% and red-green-blue (RGB) spectral composition of 51.67%. Besides, the TAP-CDs exhibit satisfying thermal stability within 180 °C. By virtue of good optical and thermal properties of TAP-CDs, a white light-emitting device (LED) was fabricated by combining ultraviolet chip with TAP-CDs as phosphor. The white LED emits bright warm-white light with the CIE chromaticity coordinate of (0.38, 0.35) and the corresponding color temperature (CCT) of 4450 K, indicating the potential of TAP-CDs phosphor in white LED.

  13. Optimization of high-inclination orbits using planetary flybys for a zodiacal light-imaging mission

    Science.gov (United States)

    Soto, Gabriel; Lloyd, James; Savransky, Dmitry; Grogan, Keith; Sinha, Amlan

    2017-09-01

    The zodiacal light caused by interplanetary dust grains is the second-most luminous source in the solar system. The dust grains coalesce into structures reminiscent of early solar system formation; their composition has been predicted through simulations and some edge-on observations but better data is required to validate them. Scattered light from these dust grains presents challenges to exoplanet imaging missions: resolution of their stellar environment is hindered by exozodiacal emissions and therefore sets the size and scope of these imaging missions. Understanding the composition of this interplanetary dust in our solar system requires an imaging mission from a vantage point above the ecliptic plane. The high surface brightness of the zodiacal light requires only a small aperture with moderate sensitivity; therefore a 3cm camera is enough to meet the science goals of the mission at an orbital height of 0.1AU above the ecliptic. A 6U CubeSat is the target mass for this mission which will be a secondary payload detaching from an existing interplanetary mission. Planetary flybys are utilized to produce most of the plane change Δv deep space corrective maneuvers are implemented to optimize each planetary flyby. We developed an algorithm which determines the minimum Δv required to place the CubeSat on a transfer orbit to a planet's sphere of influence and maximizes the resultant orbital height with respect to the ecliptic plane. The satellite could reach an orbital height of 0.22 AU with an Earth gravity assist in late 2024 by boarding the Europa Clipper mission.

  14. Microhabitat Conditions in Wyoming's Sage-Grouse Core Areas: Effects on Nest Site Selection and Success.

    Science.gov (United States)

    Dinkins, Jonathan B; Smith, Kurt T; Beck, Jeffrey L; Kirol, Christopher P; Pratt, Aaron C; Conover, Michael R

    2016-01-01

    The purpose of our study was to identify microhabitat characteristics of greater sage-grouse (Centrocercus urophasianus) nest site selection and survival to determine the quality of sage-grouse habitat in 5 regions of central and southwest Wyoming associated with Wyoming's Core Area Policy. Wyoming's Core Area Policy was enacted in 2008 to reduce human disturbance near the greatest densities of sage-grouse. Our analyses aimed to assess sage-grouse nest selection and success at multiple micro-spatial scales. We obtained microhabitat data from 928 sage-grouse nest locations and 819 random microhabitat locations from 2008-2014. Nest success was estimated from 924 nests with survival data. Sage-grouse selected nests with greater sagebrush cover and height, visual obstruction, and number of small gaps between shrubs (gap size ≥0.5 m and sage-grouse were selecting different nest sites in Core Areas relative to areas outside of Core. The Kaplan-Meier nest success estimate for a 27-day incubation period was 42.0% (95% CI: 38.4-45.9%). Risk of nest failure was negatively associated with greater rock and more medium-sized gaps between shrubs (gap size ≥2.0 m and <3.0 m). Within our study areas, Wyoming's Core Areas did not have differing microhabitat quality compared to outside of Core Areas. The close proximity of our locations within and outside of Core Areas likely explained our lack of finding differences in microhabitat quality among locations within these landscapes. However, the Core Area Policy is most likely to conserve high quality habitat at larger spatial scales, which over decades may have cascading effects on microhabitat quality available between areas within and outside of Core Areas.

  15. Performance optimization of solar driven small-cooled absorption–diffusion chiller working with light hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Sayadi, Zouhour [U.R. Thermique et Thermodynamique des Procédés Industriels, Ecole Nationale d’Ingénieurs de Monastir (ENIM), Av. Ibn Jazzar, 5060 Monastir (Tunisia); Ben Thameur, Nizar, E-mail: nizarbenthameur@yahoo.fr [U.R. Thermique et Thermodynamique des Procédés Industriels, Ecole Nationale d’Ingénieurs de Monastir (ENIM), Av. Ibn Jazzar, 5060 Monastir (Tunisia); Bourouis, Mahmoud [Mechanical Engineering Department, Universitat Rovira i Virgili, 43007 Tarragona (Spain); Bellagi, Ahmed [U.R. Thermique et Thermodynamique des Procédés Industriels, Ecole Nationale d’Ingénieurs de Monastir (ENIM), Av. Ibn Jazzar, 5060 Monastir (Tunisia)

    2013-10-15

    Highlights: • 1 kW{sub cooling} diffusion/absorption machine with light hydrocarbons as working fluids. • Hysys optimization to choose the optimal mixture for a better machine performance. • Cooling loads for a small bed-room (16 m{sup 2}) have been estimated into TRNSYS. • Economic assessment to choose the best combination of solar equipments. • Energy savings, CO{sub 2} avoided and equivalent gasoil and Diesel saved energy. - Abstract: We present in this paper a HYSYS (Aspen One) model and simulation results for 1 kW capacity water-cooled absorption/diffusion machine using different binary mixtures of light hydrocarbons as working fluids (C{sub 3}/n-C{sub 6}, C{sub 3}/c-C{sub 6}, C{sub 3}/c-C{sub 5}, propylene/c-C{sub 5}, propylene/i-C{sub 4}, propylene/i-C{sub 5}) in combination with helium as inert gas. The driving heat is supposed to be provided by an evacuated solar collector field. TRNSYS is used to address the solar aspects of the simulations. For the optimal chiller the driving heat temperature was found to be 121 °C for an evaporator exit temperature of 0 °C. The cooling water flow rate circulating between chiller and cooling tower is 140 l/h. Bubble pump and generator are heated by pressurized water from an insulated tank (70 l/m{sup 2}) maintained at a maximum temperature of 126 °C – with make-up heat when needed – and storing solar heat at an estimated 4.2 kW power. The solar energy cover only 40% for the energy supplied to drive the chiller. It’s found that the necessary collector surface area is about 6 m{sup 2} with annually total costs of 1.60 €/kW h with 20 years lifetime period for the installation. The avoided CO{sub 2} emissions are estimated at 1396 kg. The equivalent saved energy is 521 l of diesel or 604 l of gasoline.

  16. Performance optimization of solar driven small-cooled absorption–diffusion chiller working with light hydrocarbons

    International Nuclear Information System (INIS)

    Sayadi, Zouhour; Ben Thameur, Nizar; Bourouis, Mahmoud; Bellagi, Ahmed

    2013-01-01

    Highlights: • 1 kW cooling diffusion/absorption machine with light hydrocarbons as working fluids. • Hysys optimization to choose the optimal mixture for a better machine performance. • Cooling loads for a small bed-room (16 m 2 ) have been estimated into TRNSYS. • Economic assessment to choose the best combination of solar equipments. • Energy savings, CO 2 avoided and equivalent gasoil and Diesel saved energy. - Abstract: We present in this paper a HYSYS (Aspen One) model and simulation results for 1 kW capacity water-cooled absorption/diffusion machine using different binary mixtures of light hydrocarbons as working fluids (C 3 /n-C 6 , C 3 /c-C 6 , C 3 /c-C 5 , propylene/c-C 5 , propylene/i-C 4 , propylene/i-C 5 ) in combination with helium as inert gas. The driving heat is supposed to be provided by an evacuated solar collector field. TRNSYS is used to address the solar aspects of the simulations. For the optimal chiller the driving heat temperature was found to be 121 °C for an evaporator exit temperature of 0 °C. The cooling water flow rate circulating between chiller and cooling tower is 140 l/h. Bubble pump and generator are heated by pressurized water from an insulated tank (70 l/m 2 ) maintained at a maximum temperature of 126 °C – with make-up heat when needed – and storing solar heat at an estimated 4.2 kW power. The solar energy cover only 40% for the energy supplied to drive the chiller. It’s found that the necessary collector surface area is about 6 m 2 with annually total costs of 1.60 €/kW h with 20 years lifetime period for the installation. The avoided CO 2 emissions are estimated at 1396 kg. The equivalent saved energy is 521 l of diesel or 604 l of gasoline

  17. Long-term Spatial Distribution Patterns of Protozoa in Connected Microhabitats

    Science.gov (United States)

    Taghon, G. L.; Tuorto, S. J.

    2016-02-01

    Studies of microbial ecosystems usually assume habitat homogeneity. Recent research, however, indicates that habitat structure varies at millimeter scales and that this patchiness affects abundance and behavior of microbes. In this study, two species of ciliated protozoa were maintained, together, for multiple generations in microfluidic devices consisting of arrays of interconnected microhabitats with differing resource availability. The species differed in their population dynamics and tendency to disperse among microhabitats. Both species coexisted for over 45 days, and their coexistence likely resulted from habitat selection at millimeter scales. We demonstrate that it is not only possible, but imperative, that detailed ecological phenomena of microbial systems be studied at the relevant spatial and temporal scales.

  18. Distribution of phosphate solubilizer fungi on soil microhabitats in two landscapes from Guaviare, Colombia

    Directory of Open Access Journals (Sweden)

    Diana Fernanda Vera

    2002-01-01

    Full Text Available The distribution of the phosphate solubilizer mycobiota in two different soil microhabitats present in Guaviare, Colombia, were studied. Twelve samples from Arazá rhizosphere (Eugenia stipitata McVaugh and from soil without roots were processed using the soil wahing method (Domsch  et al., 1980. The percentage of colonization of soil particles by fungi was 69 %, with a higher intensity of colonization coming from the rhizospheric microhabitat. The high percentage of potential solubilizer colonies may point to this type of soil as reserve pf solubilizer fungi. The rhizospheric effect has been the main factor involved in the composition of the solubilizer fungi community.

  19. Microhabitat use by three species of egret (Pelecaniformes, Ardeidae in southern Brazil

    Directory of Open Access Journals (Sweden)

    DP. Pinto

    Full Text Available In the present study, we examined the role of different habitat components and their relationship with microhabitat use by three species of egret: Cocoi heron (Ardea cocoi, Great egret (Ardea alba, and Cattle egret (Bubulcus ibis, in wetlands of southern Brazil. Ardea alba and A. cocoi were not habitat-specific (e.g. vegetation cover and flooding level. Conversely, B. ibis was associated with drier microhabitats. Relative air humidity and air temperature were the main variables which correlated with the occurrence of these species and supported the plasticity of B. ibis and its predominance in drier habitats.

  20. Microhabitat partitioning between leiuperidae and bufonidae species (amphibia: anura) in tropical dry forest areas in Colombian Caribbean

    International Nuclear Information System (INIS)

    Blanco Torres, Argelina; Bonilla Gomez, Maria Argenis

    2010-01-01

    We analyzed partitioning of microhabitats by five species of frogs in the families, Bufonidae (Rhinella marina, r. granulosa), and Leiuperidae (Engystomops pustulosus, Pleurodema brachyops and Pseudopaludicola pusilla) in six different localities of the Colombian Caribbean with tropical dry forest fragments and different land uses. We identified 29 types of microhabitats; permanent ponds in pastures with trees (CPPA) and flooded pastures without trees (PISA) were the most important environmental used. Engystomops pustulosus used the must microhabitats, and none are used by specialist species. Thus, differences in the use of resource on regional and local scales appeared. Dynamics of microhabitat uses was influenced by the climatic variations of the tropical dry forest. Microhabitats distribution as a mechanism of coexistence in these species is implemented for dry season but in rainfall season this mechanism not exists.

  1. An iterative method applied to optimize the design of PIN photodiodes for enhanced radiation tolerance and maximum light response

    International Nuclear Information System (INIS)

    Cedola, A.P.; Cappelletti, M.A.; Casas, G.; Peltzer y Blanca, E.L.

    2011-01-01

    An iterative method based on numerical simulations was developed to enhance the proton radiation tolerance and the responsivity of Si PIN photodiodes. The method allows to calculate the optimal values of the intrinsic layer thickness and the incident light wavelength, in function of the light intensity and the maximum proton fluence to be supported by the device. These results minimize the effects of radiation on the total reverse current of the photodiode and maximize its response to light. The implementation of the method is useful in the design of devices whose operation point should not suffer variations due to radiation.

  2. Optimized lighting method of applying shaped-function signal for increasing the dynamic range of LED-multispectral imaging system

    Science.gov (United States)

    Yang, Xue; Hu, Yajia; Li, Gang; Lin, Ling

    2018-02-01

    This paper proposes an optimized lighting method of applying a shaped-function signal for increasing the dynamic range of light emitting diode (LED)-multispectral imaging system. The optimized lighting method is based on the linear response zone of the analog-to-digital conversion (ADC) and the spectral response of the camera. The auxiliary light at a higher sensitivity-camera area is introduced to increase the A/D quantization levels that are within the linear response zone of ADC and improve the signal-to-noise ratio. The active light is modulated by the shaped-function signal to improve the gray-scale resolution of the image. And the auxiliary light is modulated by the constant intensity signal, which is easy to acquire the images under the active light irradiation. The least square method is employed to precisely extract the desired images. One wavelength in multispectral imaging based on LED illumination was taken as an example. It has been proven by experiments that the gray-scale resolution and the accuracy of information of the images acquired by the proposed method were both significantly improved. The optimum method opens up avenues for the hyperspectral imaging of biological tissue.

  3. Light output optimization for the Cherenkov strips of the Barrel detector of FOPI

    Energy Technology Data Exchange (ETDEWEB)

    Petrovici, M; Gobbi, A; Hildenbrand, K D [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Kirejczyk, M; Sikora, B [Warsaw Univ. (Poland); Chelepov, V; Dulin, M; Frolov, S; Judentsov, A; Krylov, V; Nikitin, A; Smolyankin, V; Zhilin, A [Institute for Theoretical and Expermental Physics - ITEP, B. Chermushkinskaya ulitsa 25, RU-117 259 Moskva, (Russian Federation); Mgebrishvili, G; Vasiliev, M [I.V. Kurchatov Institute of Atomic Energy, Ulitsa Kurchatova 46, RU-123 182 Moskva, (Russian Federation)

    1994-12-31

    Available as short communication only. A systematic study on how to increase the number of the photoelectrons (PE) in the phototubes at the end of the bent light guides has been undertaken prior to the final assembly of the Cherenkov strips of the Barrel detector for the 4{pi} facility FOPI at GSI-Darmstadt. This was motivated by the observation that with the mass-produced strips only 0.8 PE were found for cosmic rays incident at the center of the 240 cm long strips, a value too low to ensure a decent detection of even {beta}=1 particles. The method used was based on a careful calibration of the amplitude spectra by means of measuring single-electron peaks in the attached tubes. As the consequence of these studies the wave-length shifter (amino G salt) concentration in the distilled water of strips was optimized and a cell of 1000 mm with a mirror on one side has been used. These changes brought a improvement factor of 9 in the number of PE at 85 cm distance from the light guide. This results led to the decision of changing the former design of the Cherenkov layer. In addition during production of these final modules it has been observed that variances between different strips in terms of the number of PE could be minimized by an outer polishing of the plexiglas cells. Finally, during mounting of the detectors the used phototubes were selected according to their performance in peak to valley ratio of the single electron peaks spectrum. (Author) 3 Figs., 2 Refs.

  4. Habitat connectivity as a metric for aquatic microhabitat quality: Application to Chinook salmon spawning habitat

    Science.gov (United States)

    Ryan Carnie; Daniele Tonina; Jim McKean; Daniel Isaak

    2016-01-01

    Quality of fish habitat at the scale of a single fish, at the metre resolution, which we defined here as microhabitat, has been primarily evaluated on short reaches, and their results have been extended through long river segments with methods that do not account for connectivity, a measure of the spatial distribution of habitat patches. However, recent...

  5. Ecomorphological adaptations in Collembola in relation to feeding strategies and microhabitat

    NARCIS (Netherlands)

    Malcicka, Miriama; Berg, Matty P.; Ellers, Jacintha

    2017-01-01

    Some of the most important functional traits in animals are related to the potentially vast array of feeding strategies and microhabitat use. Correlated evolution of diet and habitat specialization with ecomorphological traits has been described in vertebrates, but such functional trait variation in

  6. Aggregated and dispersed configuration of microhabitats in coastal defenses: Implications for restoration of populations

    Directory of Open Access Journals (Sweden)

    Eva Cacabelos

    2014-06-01

    Full Text Available The additions of artificial structures to the landscape are usually translated into habitat loss and fragmentation, since they provide homogeneous habitats less diverse in types and number of microhabitats. Moreover, the smooth surface of artificial structures increases the degree of environmental stress (e.g. desiccation experienced by intertidal organisms. Local biodiversity can be increased with microhabitats availability by attracting or supporting species of macrofauna and seaweeds. E.g., distribution and survival of the mollusc Patella candei, a limpet exploited in intertidal coasts of Açores, has been showed to be strongly influenced by availability of microhabitats. We experimentally analyzed the influence of microhabitat aggregation and dispersion on the distribution of several species of gastropods on midshores of artificial substrates. Data were compared with distributions within unmanipulated plots. Effects were found among treatments and control plots in densities of Tectarius striatus and at the different life-history stages of limpets (recruits, immature and adult individuals inhabiting artificial substrata with manipulated aggregation levels. In case of Melaraphe neritoides, only in site 2 numbers of were greater in manipulated than in control plots. Configurations with different dispersion levels also showed greater densities than controls. Both aggregation and dispersion effects were more evident at site 2; however, due to the high variability among examined plots, no clear significant responses were found among the different treatments.

  7. Composition of soil seed bank over cholistan desert microhabitats at dingarh for area, pakistan

    International Nuclear Information System (INIS)

    Hamid, A.; Arshad, M.; Ghazali, H.M.Z.

    2016-01-01

    Soil seed banks were assessed in three soil layers (L1, from 0 to 2 cm, L2, 2 to 4 cm and L3, 4 to 6 cm depth ) from five microhabitats i.e., Lee-ward side of sand dune (S1), Wind-ward side of sand dune (S2), Clayey area covered with sand (S3), Interdunal sandy area (S4) and Shifting sand dune of site Dingarh Fort area (S5) in Cholistan desert of Pakistan to analyse differences of soil seed bank among these habitats. Ten soil samples were collected from each microhabitat and from each layer i.e., 0-2 cm depth (L1), 2-4 cm depth (L2) and 4-6 cm depth (L3) by using 15*15*6 cm metallic sampler. Consistent differences in seed composition were observed among these microhabitats. Seedling emergence approach was used to assess the soil seed bank of Cholistan desert. Canonical correspondence analysis (CCA) was used for the soil seed bank and the plant species analysis. The microhabitats S3 (Clayey area covered with sand) and S4 (Interdunal sandy area) contributed prominently to the total variance in the species and had maximum density of seed bank and soil layer L1 contained maximum number of seeds. (author)

  8. Effects of microhabitat and land use on stream salamander abundance in the southwest Virginia coalfields

    Science.gov (United States)

    Sweeten, Sara E.; Ford, W. Mark

    2015-01-01

    Large-scale land uses such as residential wastewater discharge and coal mining practices, particularly surface coal extraction and associated valley fills, are of particular ecological concern in central Appalachia. Identification and quantification of both alterations across scales are a necessary first-step to mitigate negative consequences to biota. In central Appalachian headwater streams absent of fish, salamanders are the dominant, most abundant vertebrate predator providing a significant intermediate trophic role. Stream salamander species are considered to be sensitive to aquatic stressors and environmental alterations, and past research has shown linkages among microhabitat parameters, large-scale land use such as urbanization and logging with salamander abundances. However, little is known about these linkages in the coalfields of central Appalachia. In the summer of 2013, we visited 70 sites (sampled three times each) in the southwest Virginia coalfields to survey salamanders and quantify stream and riparian microhabitat parameters. Using an information-theoretic framework we compared the effects of microhabitat and large-scale land use on salamander abundances. Our findings indicate that dusky salamander (Desmognathus spp.) abundances are more correlated to microhabitat parameters such as canopy cover than to subwatershed land uses. Brook salamander (Eurycea spp.) abundances show strong negative associations to the suspended sediments and stream substrate embeddedness. Neither Desmognathus spp. nor Eurycea spp. abundances were influenced by water conductivity. These suggest protection or restoration of riparian habitats and erosion control is an important conservation component for maintaining stream salamanders in the mined landscapes of central Appalachia.

  9. Foraging sites of Eurasian lynx Lynx lynx: relative importance of microhabitat and prey occurrence

    Czech Academy of Sciences Publication Activity Database

    Belotti, E.; Červený, J.; Šustr, Pavel; Kreisinger, Jakub; Gaibani, G.; Bufka, L.

    2013-01-01

    Roč. 19, č. 2 (2013), s. 188-201 ISSN 0909-6396 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:68081766 ; RVO:67179843 Keywords : Eurasian Lynx * microhabitat * red deer * roe deer * stalking cover * predation Subject RIV: EH - Ecology, Behaviour Impact factor: 1.071, year: 2013

  10. Detecting and locating light atoms from high-resolution STEM images : The quest for a single optimal design

    NARCIS (Netherlands)

    Gonnissen, J; De Backer, A; den Dekker, A.J.; Sijbers, J.; Van Aert, S.

    2016-01-01

    In the present paper, the optimal detector design is investigated for both detecting and locating light atoms from high resolution scanning transmission electron microscopy (HR STEM) images. The principles of detection theory are used to quantify the probability of error for the detection of

  11. Microhabitat Conditions in Wyoming's Sage-Grouse Core Areas: Effects on Nest Site Selection and Success.

    Directory of Open Access Journals (Sweden)

    Jonathan B Dinkins

    Full Text Available The purpose of our study was to identify microhabitat characteristics of greater sage-grouse (Centrocercus urophasianus nest site selection and survival to determine the quality of sage-grouse habitat in 5 regions of central and southwest Wyoming associated with Wyoming's Core Area Policy. Wyoming's Core Area Policy was enacted in 2008 to reduce human disturbance near the greatest densities of sage-grouse. Our analyses aimed to assess sage-grouse nest selection and success at multiple micro-spatial scales. We obtained microhabitat data from 928 sage-grouse nest locations and 819 random microhabitat locations from 2008-2014. Nest success was estimated from 924 nests with survival data. Sage-grouse selected nests with greater sagebrush cover and height, visual obstruction, and number of small gaps between shrubs (gap size ≥0.5 m and <1.0 m, while selecting for less bare ground and rock. With the exception of more small gaps between shrubs, we did not find any differences in availability of these microhabitat characteristics between locations within and outside of Core Areas. In addition, we found little supporting evidence that sage-grouse were selecting different nest sites in Core Areas relative to areas outside of Core. The Kaplan-Meier nest success estimate for a 27-day incubation period was 42.0% (95% CI: 38.4-45.9%. Risk of nest failure was negatively associated with greater rock and more medium-sized gaps between shrubs (gap size ≥2.0 m and <3.0 m. Within our study areas, Wyoming's Core Areas did not have differing microhabitat quality compared to outside of Core Areas. The close proximity of our locations within and outside of Core Areas likely explained our lack of finding differences in microhabitat quality among locations within these landscapes. However, the Core Area Policy is most likely to conserve high quality habitat at larger spatial scales, which over decades may have cascading effects on microhabitat quality available

  12. Microhabitat of small mammals at ground and understorey levels in a deciduous, southern Atlantic Forest

    Directory of Open Access Journals (Sweden)

    GERUZA L. MELO

    2013-06-01

    Full Text Available Each animal species selects specific microhabitats for protection, foraging, or micro-climate. To understand the distribution patterns of small mammals on the ground and in the understorey, we investigated the use of microhabitats by small mammals in a deciduous forest of southern Brazil. Ten trap stations with seven capture points were used to sample the following microhabitats: liana, fallen log, ground litter, terrestrial ferns, simple-trunk tree, forked tree, and Piper sp. shrubs. Seven field phases were conducted, each for eight consecutive days, from September 2006 through January 2008. Four species of rodents (Akodon montensis, Sooretamys angouya, Oligoryzomys nigripes and Mus musculus and two species of marsupials (Didelphis albiventris and Gracilinanus microtarsus were captured. Captured species presented significant differences on their microhabitat use (ANOVA, p = 0.003, particularly between ground and understorey sites. Akodon montensis selected positively terrestrial ferns and trunks, S. angouya selected lianas, D. albiventris selected fallen trunks and Piper sp., and G. microtarsus choose tree trunks and lianas. We demonstrated that the local small-mammal assemblage does select microhabitats, with different types of associations between species and habitats. Besides, there is a strong evidence of habitat selection in order to diminish predation.Cada espécie animal pode apresentar seletividade por micro-habitats priorizando proteção, forrageio ou microclima. Para compreender os padrões de distribuição de pequenos mamíferos ao nível do solo e de sub-bosque, nós analisamos o uso de micro-habitat por pequenos mamíferos em uma floresta estacional no sul do Brasil. Dez estações amostrais com sete pontos de captura foram usadas para amostragem dos seguintes microhabitats: liana, tronco caído, solo apenas coberto por folhiço, solo coberto por samambaias, árvore com tronco simples, árvore com bifurcações e arbustos do g

  13. Design and optimization of a volume-phase holographic grating for simultaneous use with red, green, and blue light using unpolarized light.

    Science.gov (United States)

    Mahamat, Adoum H; Narducci, Frank A; Schwiegerling, James

    2016-03-01

    Volume-phase holographic (VPH) gratings have been designed for use in many areas of science and technology, such as optical communication, optical imaging, and astronomy. In this paper, the design of a volume-phase holographic grating, simultaneously optimized to operate in the red, green, and blue wavelengths, is presented along with a study of its fabrication tolerances. The grating is optimized to produce 98% efficiency at λ=532  nm and at least 75% efficiency in the region between 400 and 700 nm, when the incident light is unpolarized. The optimization is done for recording in dichromated gelatin with a thickness of 12 μm, an average refractive index of 1.5, and a refractive index modulation of 0.022.

  14. Light

    CERN Document Server

    Robertson, William C

    2003-01-01

    Why is left right and right left in the mirror? Baffled by the basics of reflection and refraction? Wondering just how the eye works? If you have trouble teaching concepts about light that you don t fully grasp yourself, get help from a book that s both scientifically accurate and entertaining with Light. By combining clear explanations, clever drawings, and activities that use easy-to-find materials, this book covers what science teachers and parents need to know to teach about light with confidence. It uses ray, wave, and particle models of light to explain the basics of reflection and refraction, optical instruments, polarization of light, and interference and diffraction. There s also an entire chapter on how the eye works. Each chapter ends with a Summary and Applications section that reinforces concepts with everyday examples. Whether you need a deeper understanding of how light bends or a good explanation of why the sky is blue, you ll find Light more illuminating and accessible than a college textbook...

  15. General method for simultaneous optimization of light trapping and carrier collection in an ultra-thin film organic photovoltaic cell

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Cheng-Chia, E-mail: ct2443@columbia.edu; Grote, Richard R.; Beck, Jonathan H.; Kymissis, Ioannis [Department of Electrical Engineering, Columbia University, New York, New York 10027 (United States); Osgood, Richard M. [Department of Electrical Engineering, Columbia University, New York, New York 10027 (United States); Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States); Englund, Dirk [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2014-07-14

    We describe a general method for maximizing the short-circuit current in thin planar organic photovoltaic (OPV) heterojunction cells by simultaneous optimization of light absorption and carrier collection. Based on the experimentally obtained complex refractive indices of the OPV materials and the thickness-dependence of the internal quantum efficiency of the OPV active layer, we analyze the potential benefits of light trapping strategies for maximizing the overall power conversion efficiency of the cell. This approach provides a general strategy for optimizing the power conversion efficiency of a wide range of OPV structures. In particular, as an experimental trial system, the approach is applied here to a ultra-thin film solar cell with a SubPc/C{sub 60} photovoltaic structure. Using a patterned indium tin oxide (ITO) top contact, the numerically optimized designs achieve short-circuit currents of 0.790 and 0.980 mA/cm{sup 2} for 30 nm and 45 nm SubPc/C{sub 60} heterojunction layer thicknesses, respectively. These values correspond to a power conversion efficiency enhancement of 78% for the 30 nm thick cell, but only of 32% for a 45 nm thick cell, for which the overall photocurrent is actually higher. Applied to other material systems, the general optimization method can elucidate if light trapping strategies can improve a given cell architecture.

  16. Optimization of superconducting bending magnets for a 1.0 to 1.5 GeV compact light source

    International Nuclear Information System (INIS)

    Green, M.A.; Garren, A.A.

    1995-06-01

    Compact light sources are being proposed for protein crystallography, medical imaging, nano-machining and other areas of study that require intense sources of x rays at energies up to 35 keV. In order for a synchrotron light source to be attractive, its capital cost must, be kept low. The proposed compact light source has superconducting bending elements to bend the stored beam and produce the x rays. Additional focusing for the machine is provided by conventional quadrupoles. An important part of the cost optimization of a compact light source is the cost of the bending magnets. In the case of a machine with superconducting bending elements, the bending magnet system can represent close to half of the storage ring cost. The compact light source storage rings studied here have a range of stored electron energies from 1.0 to 1.5 GeV. For a number of reasons, it is desirable to keep the storage ring circumference below 30 meters. Cost optimization parameters include: (1) the number of superconducting bending elements in the ring, and (2) the central induction of the dipole. A machine design that features two superconducting dipoles in a single cryostat vacuum vessel is also discussed

  17. Introduction to HOBIT, a b-jet identification tagger at the CDF experiment optimized for light Higgs boson searches

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, J.; Junk, T.; Kirby, M.; Oksuzian, Y.; Phillips, T. J.; Snider, F. D.; Trovato, M.; Vizan, J.; Yao, W. M.

    2013-01-01

    We present the development and validation of the Higgs Optimized b Identification Tagger (HOBIT), a multivariate b-jet identification algorithm optimized for Higgs boson searches at the CDF experiment at the Fermilab Tevatron. At collider experiments, b taggers allow one to distinguish particle jets containing B hadrons from other jets; these algorithms have been used for many years with great success at CDF. HOBIT has been designed specifically for use in searches for light Higgs bosons decaying via H ! b\\bar{b}. This fact combined with the extent to which HOBIT synthesizes and extends the best ideas of previous taggers makes HOBIT unique among CDF b-tagging algorithms. Employing feed-forward neural network architectures, HOBIT provides an output value ranging from approximately -1 ("light-jet like") to 1 ("b-jet like"); this continuous output value has been tuned to provide maximum sensitivity in light Higgs boson search analyses. When tuned to the equivalent light jet rejection rate, HOBIT tags 54% of b jets in simulated 120 GeV/c2 Higgs boson events compared to 39% for SecVtx, the most commonly used b tagger at CDF. We present features of the tagger as well as its characterization in the form of b-jet finding efficiencies and false (light-jet) tag rates.

  18. Light

    CERN Document Server

    Ditchburn, R W

    1963-01-01

    This classic study, available for the first time in paperback, clearly demonstrates how quantum theory is a natural development of wave theory, and how these two theories, once thought to be irreconcilable, together comprise a single valid theory of light. Aimed at students with an intermediate-level knowledge of physics, the book first offers a historical introduction to the subject, then covers topics such as wave theory, interference, diffraction, Huygens' Principle, Fermat's Principle, and the accuracy of optical measurements. Additional topics include the velocity of light, relativistic o

  19. A New Software for Management, Scheduling, and Optimization for the Light Hydrocarbon Pipeline Network System of Daqing Oilfield

    Directory of Open Access Journals (Sweden)

    Yongtu Liang

    2014-01-01

    Full Text Available This paper presents the new software which specifically developed based on Visual Studio 2010 for Daqing Oilfield China includes the most complex light hydrocarbon pipeline network system in Asia, has become a powerful auxiliary tool to manage field data, makes scheduling plans for batching operation, and optimizes pumping plans. Firstly, DMM for recording and managing field data is summarized. Then, the batch scheduling simulation module called SSM for the difficult batch-scheduling issues of the multiple-source pipeline network system is introduced. Finally, SOM, that is Scheduling Optimization Module, is indicated for solving the problem of the pumps being started up/shut-down frequently.

  20. Light-trapping optimization in wet-etched silicon photonic crystal solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Eyderman, Sergey, E-mail: sergey.eyderman@utoronto.ca [Department of Physics, University of Toronto, 60 St. George Street, Toronto, Ontario M5S 1A7 (Canada); John, Sajeev [Department of Physics, University of Toronto, 60 St. George Street, Toronto, Ontario M5S 1A7 (Canada); Department of Physics, King Abdul-Aziz University, Jeddah (Saudi Arabia); Hafez, M.; Al-Ameer, S. S.; Al-Harby, T. S.; Al-Hadeethi, Y. [Department of Physics, King Abdul-Aziz University, Jeddah (Saudi Arabia); Bouwes, D. M. [iX-factory GmbH, Konrad Adenauer–Allee 11, 44263 Dortmund (Germany)

    2015-07-14

    We demonstrate, by numerical solution of Maxwell's equations, near-perfect solar light-trapping and absorption over the 300–1100 nm wavelength band in silicon photonic crystal (PhC) architectures, amenable to fabrication by wet-etching and requiring less than 10 μm (equivalent bulk thickness) of crystalline silicon. These PhC's consist of square lattices of inverted pyramids with sides comprised of various (111) silicon facets and pyramid center-to-center spacing in the range of 1.3–2.5 μm. For a wet-etched slab with overall height H = 10 μm and lattice constant a = 2.5 μm, we find a maximum achievable photo-current density (MAPD) of 42.5 mA/cm{sup 2}, falling not far from 43.5 mA/cm{sup 2}, corresponding to 100% solar absorption in the range of 300–1100 nm. We also demonstrate a MAPD of 37.8 mA/cm{sup 2} for a thinner silicon PhC slab of overall height H = 5 μm and lattice constant a = 1.9 μm. When H is further reduced to 3 μm, the optimal lattice constant for inverted pyramids reduces to a = 1.3 μm and provides the MAPD of 35.5 mA/cm{sup 2}. These wet-etched structures require more than double the volume of silicon, in comparison to the overall mathematically optimum PhC structure (consisting of slanted conical pores), to achieve the same degree of solar absorption. It is suggested these 3–10 μm thick structures are valuable alternatives to currently utilized 300 μm-thick textured solar cells and are suitable for large-scale fabrication by wet-etching.

  1. Development and Optimization of Gas-Assisted Gravity Drainage (GAGD) Process for Improved Light Oil Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Dandina N. Rao; Subhash C. Ayirala; Madhav M. Kulkarni; Wagirin Ruiz Paidin; Thaer N. N. Mahmoud; Daryl S. Sequeira; Amit P. Sharma

    2006-09-30

    This is the final report describing the evolution of the project ''Development and Optimization of Gas-Assisted Gravity Drainage (GAGD) Process for Improved Light Oil Recovery'' from its conceptual stage in 2002 to the field implementation of the developed technology in 2006. This comprehensive report includes all the experimental research, models developments, analyses of results, salient conclusions and the technology transfer efforts. As planned in the original proposal, the project has been conducted in three separate and concurrent tasks: Task 1 involved a physical model study of the new GAGD process, Task 2 was aimed at further developing the vanishing interfacial tension (VIT) technique for gas-oil miscibility determination, and Task 3 was directed at determining multiphase gas-oil drainage and displacement characteristics in reservoir rocks at realistic pressures and temperatures. The project started with the task of recruiting well-qualified graduate research assistants. After collecting and reviewing the literature on different aspects of the project such gas injection EOR, gravity drainage, miscibility characterization, and gas-oil displacement characteristics in porous media, research plans were developed for the experimental work to be conducted under each of the three tasks. Based on the literature review and dimensional analysis, preliminary criteria were developed for the design of the partially-scaled physical model. Additionally, the need for a separate transparent model for visual observation and verification of the displacement and drainage behavior under gas-assisted gravity drainage was identified. Various materials and methods (ceramic porous material, Stucco, Portland cement, sintered glass beads) were attempted in order to fabricate a satisfactory visual model. In addition to proving the effectiveness of the GAGD process (through measured oil recoveries in the range of 65 to 87% IOIP), the visual models demonstrated

  2. Evolution of morphology and locomotor performance in anurans: relationships with microhabitat diversification.

    Science.gov (United States)

    Citadini, J M; Brandt, R; Williams, C R; Gomes, F R

    2018-03-01

    The relationships between morphology, performance, behavior and ecology provide evidence for multiple and complex phenotypic adaptations. The anuran body plan, for example, is evolutionarily conserved and shows clear specializations to jumping performance back at least to the early Jurassic. However, there are instances of more recent adaptation to habit diversity in the post-cranial skeleton, including relative limb length. The present study tested adaptive models of morphological evolution in anurans associated with the diversity of microhabitat use (semi-aquatic arboreal, fossorial, torrent, and terrestrial) in species of anuran amphibians from Brazil and Australia. We use phylogenetic comparative methods to determine which evolutionary models, including Brownian motion (BM) and Ornstein-Uhlenbeck (OU) are consistent with morphological variation observed across anuran species. Furthermore, this study investigated the relationship of maximum distance jumped as a function of components of morphological variables and microhabitat use. We found there are multiple optima of limb lengths associated to different microhabitats with a trend of increasing hindlimbs in torrent, arboreal, semi-aquatic whereas fossorial and terrestrial species evolve toward optima with shorter hindlimbs. Moreover, arboreal, semi-aquatic and torrent anurans have higher jumping performance and longer hindlimbs, when compared to terrestrial and fossorial species. We corroborate the hypothesis that evolutionary modifications of overall limb morphology have been important in the diversification of locomotor performance along the anuran phylogeny. Such evolutionary changes converged in different phylogenetic groups adapted to similar microhabitat use in two different zoogeographical regions. © 2018 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2018 European Society For Evolutionary Biology.

  3. Microhabitat Association of Cryptobenthic Reef Fishes (Teleostei: Gobiidae) in the Central Red Sea

    KAUST Repository

    Troyer, Emily

    2018-05-01

    Knowledge of biodiversity within an ecosystem is essential when trying to understand the function and importance of that ecosystem. A challenge when assessing biodiversity of reef habitats is cryptobenthic fishes, which encompass many groups that have close associations with the substrate. These fishes can be behaviorally cryptic, by seeking refuge within the reef matrix, or visually cryptic, using cryptic coloration to match the surrounding habitat. These factors make visual surveys inadequate for sampling these fishes. One such group of cryptobenthic fishes are the gobies, family Gobiidae, which currently represent over 1600 species, although new species are continually being discovered. Gobies are often small (less than 5 cm), and many species will be associated with a very specific microhabitat type. Due to the understudied nature of the Red Sea, little is known about habitat preferences of gobies within the region. In order to determine the differences in goby community structure within the central Red Sea, fishes were sampled at one reef using 1 m² enclosed rotenone stations from three distinct microhabitats: hard coral, rubble, and sand. Following collection, specimens were photographed and sequenced using COI, to aid in species identification. 232 individuals were collected representing 31 species of goby. Rubble microhabitats were found to host the majority of collected gobies (69%), followed by hard coral (20.6%), then sand (9.9%). Goby assemblages in the three microhabitats were significantly different from each other, and evidence of habitat-specialists was found. These results provide essential baseline information about the ecology of understudied cryptobenthic fishes that can be used in future large-scale studies in the Red Sea region.

  4. Bacterial, Archaeal, and Eukaryotic Diversity across Distinct Microhabitats in an Acid Mine Drainage

    Directory of Open Access Journals (Sweden)

    Victoria Mesa

    2017-09-01

    Full Text Available Acid mine drainages are characterized by their low pH and the presence of dissolved toxic metallic species. Microorganisms survive in different microhabitats within the ecosystem, namely water, sediments, and biofilms. In this report, we surveyed the microbial diversity within all domains of life in the different microhabitats at Los Rueldos abandoned mercury underground mine (NW Spain, and predicted bacterial function based on community composition. Sediment samples contained higher proportions of soil bacteria (AD3, Acidobacteria, as well as Crenarchaeota and Methanomassiliicoccaceae archaea. Oxic and hypoxic biofilm samples were enriched in bacterial iron oxidizers from the genus Leptospirillum, order Acidithiobacillales, class Betaproteobacteria, and archaea from the class Thermoplasmata. Water samples were enriched in Cyanobacteria and Thermoplasmata archaea at a 3–98% of the sunlight influence, whilst Betaproteobacteria, Thermoplasmata archaea, and Micrarchaea dominated in acid water collected in total darkness. Stalactites hanging from the Fe-rich mine ceiling were dominated by the neutrophilic iron oxidizer Gallionella and other lineages that were absent in the rest of the microhabitats (e.g., Chlorobi, Chloroflexi. Eukaryotes were detected in biofilms and open-air water samples, and belonged mainly to clades SAR (Alveolata and Stramenopiles, and Opisthokonta (Fungi. Oxic and hypoxic biofilms displayed higher proportions of ciliates (Gonostomum, Oxytricha, whereas water samples were enriched in fungi (Paramicrosporidium and unknown microbial Helotiales. Predicted function through bacterial community composition suggested adaptive evolutive convergence of function in heterogeneous communities. Our study showcases a broad description of the microbial diversity across different microhabitats in the same environment and expands the knowledge on the diversity of microbial eukaryotes in AMD habitats.

  5. Bacterial, Archaeal, and Eukaryotic Diversity across Distinct Microhabitats in an Acid Mine Drainage

    Science.gov (United States)

    Mesa, Victoria; Gallego, Jose L. R.; González-Gil, Ricardo; Lauga, Béatrice; Sánchez, Jesús; Méndez-García, Celia; Peláez, Ana I.

    2017-01-01

    Acid mine drainages are characterized by their low pH and the presence of dissolved toxic metallic species. Microorganisms survive in different microhabitats within the ecosystem, namely water, sediments, and biofilms. In this report, we surveyed the microbial diversity within all domains of life in the different microhabitats at Los Rueldos abandoned mercury underground mine (NW Spain), and predicted bacterial function based on community composition. Sediment samples contained higher proportions of soil bacteria (AD3, Acidobacteria), as well as Crenarchaeota and Methanomassiliicoccaceae archaea. Oxic and hypoxic biofilm samples were enriched in bacterial iron oxidizers from the genus Leptospirillum, order Acidithiobacillales, class Betaproteobacteria, and archaea from the class Thermoplasmata. Water samples were enriched in Cyanobacteria and Thermoplasmata archaea at a 3–98% of the sunlight influence, whilst Betaproteobacteria, Thermoplasmata archaea, and Micrarchaea dominated in acid water collected in total darkness. Stalactites hanging from the Fe-rich mine ceiling were dominated by the neutrophilic iron oxidizer Gallionella and other lineages that were absent in the rest of the microhabitats (e.g., Chlorobi, Chloroflexi). Eukaryotes were detected in biofilms and open-air water samples, and belonged mainly to clades SAR (Alveolata and Stramenopiles), and Opisthokonta (Fungi). Oxic and hypoxic biofilms displayed higher proportions of ciliates (Gonostomum, Oxytricha), whereas water samples were enriched in fungi (Paramicrosporidium and unknown microbial Helotiales). Predicted function through bacterial community composition suggested adaptive evolutive convergence of function in heterogeneous communities. Our study showcases a broad description of the microbial diversity across different microhabitats in the same environment and expands the knowledge on the diversity of microbial eukaryotes in AMD habitats. PMID:28955322

  6. [Characteristics of foliar delta13C values of common shrub species in various microhabitats with different karst rocky desertification degrees].

    Science.gov (United States)

    Du, Xue-Lian; Wang, Shi-Jie; Rong, Li

    2011-12-01

    By measuring the foliar delta13C values of 5 common shrub species (Rhamnus davurica, Pyracantha fortuneana, Rubus biflorus, Zanthoxylum planispinum, and Viburnum utile) growing in various microhabitats in Wangjiazhai catchment, a typical karst desertification area in Guizhou Province, this paper studied the spatial heterogeneity of plant water use at niche scale and the response of the heterogeneity to different karst rocky desertification degrees. The foliar delta13C values of the shrub species in the microhabitats followed the order of stony surface > stony gully > stony crevice > soil surface, and those of the majority of the species were more negative in the microhabitat soil surface than in the others. The foliar delta13C values decreased in the sequence of V. utile > R. biflorus > Z. planispinum > P. fortuneana > R. davurica, and the mean foliar delta13C value of the shrubs and that of typical species in various microhabitats all increased with increasing karst rocky desertification degree, differed significantly among different microhabitats. It was suggested that with the increasing degree of karst rocky desertification, the structure and functions of karst habitats were impaired, microhabitats differentiated gradually, and drought degree increased.

  7. Microhabitat occupation by birds in a restinga fragment of Paraná coast, PR, Brazil

    Directory of Open Access Journals (Sweden)

    Nelson Novaes Pedroso Junior

    2003-01-01

    Full Text Available Studies were carried out to characterize microhabitat occupation by birds in a restinga fragment of Paraná coast. Were described 14 microhabitats occupied in different manners for 64 species of birds. Based on the results, could be suggested that this conspicuous class of vertebrates, together with the other elements that integrate the restinga, serve as a component to attract and stimulate the interest for the comprehension and necessity of conservation by the visitors of such ecosystem.Os cordões de restinga formam um ecossistema cuja extensão já se encontra bastante reduzida, devido à sua localização em áreas de grande interesse urbano, industrial e turístico. Nesse estudo caracterizou-se uma parcela desse tipo de ambiente e foram descritos 14 diferentes microhabitats ocupados diferencialmente por 64 espécies de aves. Sugere-se que essa conspícua classe de vertebrados, junto com os demais elementos que integram o ambiente de restinga, sirva como um componente para atrair e estimular o interesse pela compreensão e necessidade de conservação por parte dos frequentadores desse tipo de ambiente.

  8. Microhabitat use by species of the genera Bothrops and Crotalus (Viperidae in semi-extensive captivity

    Directory of Open Access Journals (Sweden)

    CA Gomes

    2012-01-01

    Full Text Available Many factors influence microhabitat including climate and the occurrence of predators, prey and suitable shelters. The influence of predators in a semi-extensive breeding system is minimized due to frequent monitoring of the area. This situation enables the independent analysis of such other variables as refuges and temperature. Some specimens of the Viperidae family are kept in a semi-extensive breeding system at the Butantan Institute for display and study. These animals are widely distributed in the Atlantic Forest and Cerrado, two biomes with distinct climatic characteristics. We compared the daily activity pattern and microhabitat use of the species Bothrops jararaca and Crotalus durissus terrificus. Our main questions were whether rattlesnakes and lancehead snakes respond to habitat selection differently in similar climatic conditions and if they choose similar microhabitats. Species of the genus Bothrops were frequently found under shelters regardless of the time of day. On the other hand, snakes of the genus Crotalus were frequently found sheltered during the early morning, then migrated to sunnier areas and returned to shelters in late afternoon.

  9. Water relations and gas exchange of fan bryophytes and their adaptations to microhabitats in an Asian subtropical montane cloud forest.

    Science.gov (United States)

    Song, Liang; Zhang, Yong-Jiang; Chen, Xi; Li, Su; Lu, Hua-Zheng; Wu, Chuan-Sheng; Tan, Zheng-Hong; Liu, Wen-Yao; Shi, Xian-Meng

    2015-07-01

    Fan life forms are bryophytes with shoots rising from vertical substratum that branch repeatedly in the horizontal plane to form flattened photosynthetic surfaces, which are well suited for intercepting water from moving air. However, detailed water relations, gas exchange characteristics of fan bryophytes and their adaptations to particular microhabitats remain poorly understood. In this study, we measured and analyzed microclimatic data, as well as water release curves, pressure-volume relationships and photosynthetic water and light response curves for three common fan bryophytes in an Asian subtropical montane cloud forest (SMCF). Results demonstrate high relative humidity but low light levels and temperatures in the understory, and a strong effect of fog on water availability for bryophytes in the SMCF. The facts that fan bryophytes in dry air lose most of their free water within 1 h, and a strong dependence of net photosynthesis rates on water content, imply that the transition from a hydrated, photosynthetically active state to a dry, inactive state is rapid. In addition, fan bryophytes developed relatively high cell wall elasticity and the osmoregulatory capacity to tolerate desiccation. These fan bryophytes had low light saturation and compensation point of photosynthesis, indicating shade tolerance. It is likely that fan bryophytes can flourish on tree trunks in the SMCF because of substantial annual precipitation, average relative humidity, and frequent and persistent fog, which can provide continual water sources for them to intercept. Nevertheless, the low water retention capacity and strong dependence of net photosynthesis on water content of fan bryophytes indicate a high risk of unbalanced carbon budget if the frequency and severity of drought increase in the future as predicted.

  10. Seeing light at the end of the tunnel: Positive prospective mental imagery and optimism in depression.

    Science.gov (United States)

    Ji, Julie L; Holmes, Emily A; Blackwell, Simon E

    2017-01-01

    Optimism is associated with positive outcomes across many health domains, from cardiovascular disease to depression. However, we know little about cognitive processes underlying optimism in psychopathology. The present study tested whether the ability to vividly imagine positive events in one's future was associated with dispositional optimism in a sample of depressed adults. Cross-sectional and longitudinal analyses were conducted, using baseline (all participants, N=150) and follow-up data (participants in the control condition only, N=63) from a clinical trial (Blackwell et al., 2015). Vividness of positive prospective imagery, assessed on a laboratory-administered task at baseline, was significantly associated with both current optimism levels at baseline and future (seven months later) optimism levels, including when controlling for potential confounds. Even when depressed, those individuals able to envision a brighter future were more optimistic, and regained optimism more quickly over time, than those less able to do so at baseline. Strategies to increase the vividness of positive prospective imagery may aid development of mental health interventions to boost optimism. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  11. The EB factory project. I. A fast, neural-net-based, general purpose light curve classifier optimized for eclipsing binaries

    International Nuclear Information System (INIS)

    Paegert, Martin; Stassun, Keivan G.; Burger, Dan M.

    2014-01-01

    We describe a new neural-net-based light curve classifier and provide it with documentation as a ready-to-use tool for the community. While optimized for identification and classification of eclipsing binary stars, the classifier is general purpose, and has been developed for speed in the context of upcoming massive surveys such as the Large Synoptic Survey Telescope. A challenge for classifiers in the context of neural-net training and massive data sets is to minimize the number of parameters required to describe each light curve. We show that a simple and fast geometric representation that encodes the overall light curve shape, together with a chi-square parameter to capture higher-order morphology information results in efficient yet robust light curve classification, especially for eclipsing binaries. Testing the classifier on the ASAS light curve database, we achieve a retrieval rate of 98% and a false-positive rate of 2% for eclipsing binaries. We achieve similarly high retrieval rates for most other periodic variable-star classes, including RR Lyrae, Mira, and delta Scuti. However, the classifier currently has difficulty discriminating between different sub-classes of eclipsing binaries, and suffers a relatively low (∼60%) retrieval rate for multi-mode delta Cepheid stars. We find that it is imperative to train the classifier's neural network with exemplars that include the full range of light curve quality to which the classifier will be expected to perform; the classifier performs well on noisy light curves only when trained with noisy exemplars. The classifier source code, ancillary programs, a trained neural net, and a guide for use, are provided.

  12. DEVELOPMENT AND OPTIMIZATION OF GAS-ASSISTED GRAVITY DRAINAGE (GAGD) PROCESS FOR IMPROVED LIGHT OIL RECOVERY

    Energy Technology Data Exchange (ETDEWEB)

    Dandina N. Rao; Subhash C. Ayirala; Madhav M. Kulkarni; Amit P. Sharma

    2004-10-01

    This report describes the progress of the project ''Development and Optimization of Gas-Assisted Gravity Drainage (GAGD) Process for Improved Light Oil Recovery'' for the duration of the second project year (October 1, 2003--September 30, 2004). There are three main tasks in this research project. Task 1 is scaled physical model study of GAGD process. Task 2 is further development of vanishing interfacial tension (VIT) technique for miscibility determination. Task 3 is determination of multiphase displacement characteristics in reservoir rocks. In Section I, preliminary design of the scaled physical model using the dimensional similarity approach has been presented. Scaled experiments on the current physical model have been designed to investigate the effect of Bond and capillary numbers on GAGD oil recovery. Experimental plan to study the effect of spreading coefficient and reservoir heterogeneity has been presented. Results from the GAGD experiments to study the effect of operating mode, Bond number and capillary number on GAGD oil recovery have been reported. These experiments suggest that the type of the gas does not affect the performance of GAGD in immiscible mode. The cumulative oil recovery has been observed to vary exponentially with Bond and capillary numbers, for the experiments presented in this report. A predictive model using the bundle of capillary tube approach has been developed to predict the performance of free gravity drainage process. In Section II, a mechanistic Parachor model has been proposed for improved prediction of IFT as well as to characterize the mass transfer effects for miscibility development in reservoir crude oil-solvent systems. Sensitivity studies on model results indicate that provision of a single IFT measurement in the proposed model is sufficient for reasonable IFT predictions. An attempt has been made to correlate the exponent (n) in the mechanistic model with normalized solute compositions present in

  13. Optimizing low-light microscopy with back-illuminated electron multiplying charge-coupled device: enhanced sensitivity, speed, and resolution.

    Science.gov (United States)

    Coates, Colin G; Denvir, Donal J; McHale, Noel G; Thornbury, Keith D; Hollywood, Mark A

    2004-01-01

    The back-illuminated electron multiplying charge-coupled device (EMCCD) camera is having a profound influence on the field of low-light dynamic cellular microscopy, combining highest possible photon collection efficiency with the ability to virtually eliminate the readout noise detection limit. We report here the use of this camera, in 512 x 512 frame-transfer chip format at 10-MHz pixel readout speed, in optimizing a demanding ultra-low-light intracellular calcium flux microscopy setup. The arrangement employed includes a spinning confocal Nipkow disk, which, while facilitating the need to both generate images at very rapid frame rates and minimize background photons, yields very weak signals. The challenge for the camera lies not just in detecting as many of these scarce photons as possible, but also in operating at a frame rate that meets the temporal resolution requirements of many low-light microscopy approaches, a particular demand of smooth muscle calcium flux microscopy. Results presented illustrate both the significant sensitivity improvement offered by this technology over the previous standard in ultra-low-light CCD detection, the GenIII+intensified charge-coupled device (ICCD), and also portray the advanced temporal and spatial resolution capabilities of the EMCCD. Copyright 2004 Society of Photo-Optical Instrumentation Engineers.

  14. Topology-optimized and dispersion-tailored photonic crystal slow-light devices

    DEFF Research Database (Denmark)

    Frandsen, Lars Hagedorn; Lavrinenko, Andrei; Borel, Peter Ingo

    2007-01-01

    , splitters, and multiplexers are a necessity in optical circuits. However, the designing of such components in the PhC platform has been a great challenge, as they often constitute severe discontinuities in the PhCW and introduce high losses. Presently, the designing of PhCW components mostly rely...... not guarantee optimal solutions. The systematic design method based on topology optimization [1] allows creation of improved PhCW components with previously unseen low transmission losses, high operational bandwidths,and/or with wavelength selective functionalities. The method was originally developed...

  15. Analysis of Optimal Process Flow Diagrams of Light Naphtha Isomerization Process by Mathematic Modelling Method

    OpenAIRE

    Chuzlov, Vyacheslav Alekseevich; Molotov, Konstantin

    2016-01-01

    An approach to simulation of hydrocarbons refining processes catalytic reactors. The kinetic and thermodynamic research of light naphtha isomerization process was conducted. The kinetic parameters of hydrocarbon feedstock chemical conversion on different types of platinum-content catalysts was established. The estimation of efficiency of including different types of isomerization technologies in oil refinery flow diagram was performed.

  16. Analysis of Optimal Process Flow Diagrams of Light Naphtha Isomerization Process by Mathematic Modelling Method

    Directory of Open Access Journals (Sweden)

    Chuzlov Vjacheslav

    2016-01-01

    Full Text Available An approach to simulation of hydrocarbons refining processes catalytic reactors. The kinetic and thermodynamic research of light naphtha isomerization process was conducted. The kinetic parameters of hydrocarbon feedstock chemical conversion on different types of platinum-content catalysts was established. The estimation of efficiency of including different types of isomerization technologies in oil refinery flow diagram was performed.

  17. Computational screening of perovskite metal oxides for optimal solar light capture

    DEFF Research Database (Denmark)

    Castelli, Ivano Eligio; Olsen, Thomas; Datta, Soumendu

    2012-01-01

    One of the possible solutions to the world’s rapidly increasing energy demand is the development of new photoelectrochemical cells with improved light absorption. This requires development of semiconductor materials which have appropriate bandgaps to absorb a large part of the solar spectrum at t...

  18. Interleaved segment correction achieves higher improvement factors in using genetic algorithm to optimize light focusing through scattering media

    Science.gov (United States)

    Li, Runze; Peng, Tong; Liang, Yansheng; Yang, Yanlong; Yao, Baoli; Yu, Xianghua; Min, Junwei; Lei, Ming; Yan, Shaohui; Zhang, Chunmin; Ye, Tong

    2017-10-01

    Focusing and imaging through scattering media has been proved possible with high resolution wavefront shaping. A completely scrambled scattering field can be corrected by applying a correction phase mask on a phase only spatial light modulator (SLM) and thereby the focusing quality can be improved. The correction phase is often found by global searching algorithms, among which Genetic Algorithm (GA) stands out for its parallel optimization process and high performance in noisy environment. However, the convergence of GA slows down gradually with the progression of optimization, causing the improvement factor of optimization to reach a plateau eventually. In this report, we propose an interleaved segment correction (ISC) method that can significantly boost the improvement factor with the same number of iterations comparing with the conventional all segment correction method. In the ISC method, all the phase segments are divided into a number of interleaved groups; GA optimization procedures are performed individually and sequentially among each group of segments. The final correction phase mask is formed by applying correction phases of all interleaved groups together on the SLM. The ISC method has been proved significantly useful in practice because of its ability to achieve better improvement factors when noise is present in the system. We have also demonstrated that the imaging quality is improved as better correction phases are found and applied on the SLM. Additionally, the ISC method lowers the demand of dynamic ranges of detection devices. The proposed method holds potential in applications, such as high-resolution imaging in deep tissue.

  19. Exploring the nature of ecological specialization in a coral reef fish community: morphology, diet and foraging microhabitat use.

    Science.gov (United States)

    Brandl, Simon J; Robbins, William D; Bellwood, David R

    2015-09-22

    Patterns of ecological specialization offer invaluable information about ecosystems. Yet, specialization is rarely quantified across several ecological niche axes and variables beyond the link between morphological and dietary specialization have received little attention. Here, we provide a quantitative evaluation of ecological specialization in a coral reef fish assemblage (f. Acanthuridae) along one fundamental and two realized niche axes. Specifically, we examined ecological specialization in 10 surgeonfish species with regards to morphology and two realized niche axes associated with diet and foraging microhabitat utilization using a recently developed multidimensional framework. We then investigated the potential relationships between morphological and behavioural specialization. These relationships differed markedly from the traditional ecomorphological paradigm. While morphological specialization showed no relationship with dietary specialization, it exhibited a strong relationship with foraging microhabitat specialization. However, this relationship was inverted: species with specialized morphologies were microhabitat generalists, whereas generalized morphotypes were microhabitat specialists. Interestingly, this mirrors relationships found in plant-pollinator communities and may also be applicable to other ecosystems, highlighting the potential importance of including niche axes beyond dietary specialization into ecomorphological frameworks. On coral reefs, it appears that morphotypes commonly perceived as most generalized may, in fact, be specialized in exploiting flat and easily accessible microhabitats. © 2015 The Author(s).

  20. There's more than one way to climb a tree: Limb length and microhabitat use in lizards with toe pads.

    Directory of Open Access Journals (Sweden)

    Travis J Hagey

    Full Text Available Ecomorphology links microhabitat and morphology. By comparing ecomorphological associations across clades, we can investigate the extent to which evolution can produce similar solutions in response to similar challenges. While Anolis lizards represent a well-studied example of repeated convergent evolution, very few studies have investigated the ecomorphology of geckos. Similar to anoles, gekkonid lizards have independently evolved adhesive toe pads and many species are scansorial. We quantified gecko and anole limb length and microhabitat use, finding that geckos tend to have shorter limbs than anoles. Combining these measurements with microhabitat observations of geckos in Queensland, Australia, we observed geckos using similar microhabitats as reported for anoles, but geckos with relatively longer limbs were using narrower perches, differing from patterns observed in anoles and other lizards. We also observed arboreal geckos with relatively shorter proximal limb segments as compared to rock-dwelling and terrestrial geckos, similar to patterns observed for other lizards. We conclude that although both geckos and anoles have adhesive pads and use similar microhabitats, their locomotor systems likely complement their adhesive pads in unique ways and result in different ecomorphological patterns, reinforcing the idea that species with convergent morphologies still have idiosyncratic characteristics due to their own separate evolutionary histories.

  1. There's more than one way to climb a tree: Limb length and microhabitat use in lizards with toe pads.

    Science.gov (United States)

    Hagey, Travis J; Harte, Scott; Vickers, Mathew; Harmon, Luke J; Schwarzkopf, Lin

    2017-01-01

    Ecomorphology links microhabitat and morphology. By comparing ecomorphological associations across clades, we can investigate the extent to which evolution can produce similar solutions in response to similar challenges. While Anolis lizards represent a well-studied example of repeated convergent evolution, very few studies have investigated the ecomorphology of geckos. Similar to anoles, gekkonid lizards have independently evolved adhesive toe pads and many species are scansorial. We quantified gecko and anole limb length and microhabitat use, finding that geckos tend to have shorter limbs than anoles. Combining these measurements with microhabitat observations of geckos in Queensland, Australia, we observed geckos using similar microhabitats as reported for anoles, but geckos with relatively longer limbs were using narrower perches, differing from patterns observed in anoles and other lizards. We also observed arboreal geckos with relatively shorter proximal limb segments as compared to rock-dwelling and terrestrial geckos, similar to patterns observed for other lizards. We conclude that although both geckos and anoles have adhesive pads and use similar microhabitats, their locomotor systems likely complement their adhesive pads in unique ways and result in different ecomorphological patterns, reinforcing the idea that species with convergent morphologies still have idiosyncratic characteristics due to their own separate evolutionary histories.

  2. Design optimization of multi-layer Silicon Carbide cladding for light water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youho, E-mail: euo@unm.edu [Department of Nuclear Engineering, University of New Mexico, MSC01 1120 1 University of New Mexico, Albuquerque, NM 87131 (United States); NO, Hee Cheon, E-mail: hcno@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Lee, Jeong Ik, E-mail: jeongiklee@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2017-01-15

    Highlights: • SiC cladding designs are optimized with a multi-layer structural analysis code. • Layer radial thickness fraction that minimizes cladding fracture probability exists. • The demonstrated procedure is applicable for multi-layer SiC cladding design. • Duplex SiC with the inner composite fraction ∼0.4 is optimal in a reference case. • Increasing composite thermal conductivity markedly decreases SiC cladding stress. - Abstract: A parametric study that demonstrates a methodology for determining the optimum bilayer composition in a duplex SiC cladding is discussed. The structural performance of multi-layer SiC cladding design is significantly affected by radial thickness fraction of each layer. This study shows that there exists an optimal composite/monolith radial thickness fraction that minimizes failure probability for a duplex SiC cladding in steady-state operation. An exemplary reference case study shows that the duplex cladding with the inner composite fraction ∼0.4 and the outer CVD-SiC fraction ∼0.6 is found to be the optimal SiC cladding design for the current PWRs with the reference material choice for CVD-SiC and fiber reinforced composite. A marginal increase in the composite fraction from the presented optimal designs may lead to increase structural integrity by introducing some unquantified merits such as increasing damage tolerance. The major factors that affect the optimum cladding designs are temperature gradients and internal gas pressure. Clad wall thickness, thermal conductivity, and Weibull modulus are among the key design parameters/material properties.

  3. Distribution Pattern of Shrimps and Fish Among Avicenniaand RhizophoraMicrohabitats in the Pagbilao Mangroves, Philippines

    Science.gov (United States)

    Rönnbäck, P.; Troell, M.; Kautsky, N.; Primavera, J. H.

    1999-02-01

    For sustainable management of mangrove ecosystems, there is a pressing need to increase our knowledge of fish and invertebrates associated with this system. This study sampled microhabitats (89-258 m 2) inside the mangrove forest at Pagbilao, the Philippines, on two consecutive spring tides using stake nets. Distribution patterns of shrimps and fish were compared among four microhabitats that differed in dominant mangrove species ( Avicennia marina, A. officinalisor Rhizophora apiculata), structural complexity of the root system, and proximity to open water habitat. A 5 to 6-year-old replanted Rhizophoramicrohabitat was also sampled to study faunal recolonization following replantation. The mean (±SE) density of the shrimp community was 1·5±0·2 shrimps m -2, dominated by Palaemonidae, followed by Acetessp., Penaeus merguiensisand Metapenaeus ensis. The highest shrimp density was observed in the replanted Rhizophorahabitat, which also had the highest structural complexity. The mean (±SE) density and biomass of the fish community was 5·1±2·0 fish m -2and 10·4±3·3 g m -2, respectively, dominated by Ambassis kopsi, A. urotaeniaand Atherinomorus balabacensis. The fish community preferred the pneumatophore ( Avicennia) microhabitats to the prop root ( Rhizophora) habitats. Highest fish abundance and biomass were observed in the most inland habitat, which also lacked larger (total length >100 mm) carnivorous fish. The results demonstrate the extensive use of intertidal mangrove forests by vagile fauna, as well as the successful recolonization by shrimps and fish of replanted Rhizophorahabitat. The role of mangroves as predation refuges, based on the distribution pattern of shrimps and fish, is discussed. Sampling strategies in mangrove intertidal habitat are also outlined.

  4. Modeling technique for optimal recovery of immiscible light hydrocarbons as free product from contaminated aquifer

    OpenAIRE

    Cooper, Grant S., Jr.; Peralta, R. C.; Kaluarachchi, J. J.

    1993-01-01

    Contamination sites associated with light non-aqueous phase liquids {LNAPL) are numerous and represent difficult cleanup problems. Remediation methods for cleanup of LNAPL fluids in subsurface systems are continuously evolving with the development of various technologies for pump.-and~treat, soil venting, and in-situ bioremediation. Evaluating the effectiveness of remediation techniques as well as attempting to improve their efficiency has been a focus of many researchers, These efforts have ...

  5. Modeling of light-emitting diode wavefronts for the optimization of transmission holograms.

    Science.gov (United States)

    Karthaus, Daniela; Giehl, Markus; Sandfuchs, Oliver; Sinzinger, Stefan

    2017-06-20

    The objective of applying transmission holograms in automotive headlamp systems requires the adaptation of holograms to divergent and polychromatic light sources like light-emitting diodes (LEDs). In this paper, four different options to describe the scalar light waves emitted by a typical automotive LED are regarded. This includes a new approach to determine the LED's wavefront from interferometric measurements. Computer-generated holograms are designed considering the different LED approximations and recorded into a photopolymer. The holograms are reconstructed with the LED and the resulting images are analyzed to evaluate the quality of the wave descriptions. In this paper, we show that our presented new approach leads to better results in comparison to other wave descriptions. The enhancement is evaluated by the correlation between reconstructed and ideal images. In contrast to the next best approximation, a spherical wave, the correlation coefficient increased by 0.18% at 532 nm, 1.69% at 590 nm, and 0.75% at 620 nm.

  6. Enhanced accumulation of glycogen, lipids and polyhydroxybutyrate under optimal nutrients and light intensities in the cyanobacterium Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Monshupanee, T; Incharoensakdi, A

    2014-04-01

    Glycogen (GL) and lipids (LP) are efficient biofuel substrates, whereas polyhydroxybutyrate (PHB) is a potent biodegradable plastic. This study aimed to increase accumulation of these three compounds in Synechocystis sp. PCC 6803. Under autophototrophic growth, co-accumulation of the three compounds reached maximum level in a mid-stationary phase at 39·2% of dry weight (22·7% GL, 14·1% LP and 2·4% PHB). Nitrogen deprivation increased this to 61·5% (36·8% GL, 11·2% LP and 13·5% PHB), higher than that achieved by phosphorus, sulfur, iron or calcium deprivation. Combining nitrogen deprivation with 0·4% (w/v) glucose addition for heterophototrophic growth and optimizing the light intensity (200 μmol photons m(-2) s(-1) ) synergistically enhanced combined accumulation to 71·1% of biomass (41·3% GL, 16·7% LP and 13·1% PHB), a higher level than previously reported in Synechocystis. However, the maximum coproductivity of GL, LP and PHB (at 0·72 g l(-1) ) was obtained in the 12-day heterophototrophic culture without nitrogen deprivation. Accumulation of GL, LP and PHB was enhanced under both autophototrophic and heterophototrophic conditions by optimizations of nutrient and light supplies. This study provides a means for increasing co-production of potent bioenergy substrates and useful biomaterials in Synechocystis which may also be applicable to other cyanobacteria. © 2013 The Society for Applied Microbiology.

  7. Design of Ru(II) sensitizers endowed by three anchoring units for adsorption mode and light harvesting optimization

    International Nuclear Information System (INIS)

    Lobello, Maria Grazia; Fantacci, Simona; Manfredi, Norberto; Coluccini, Carmine; Abbotto, Alessandro; Nazeeruddin, Mohammed K.; De Angelis, Filippo

    2014-01-01

    We report the design, synthesis and computational investigation of a class of Ru(II)-dyes based on mixed bipyridine ligands for use in dye-sensitized solar cells. These dyes are designed to preserve the optimal anchoring mode of the prototypical N719 sensitizer by three carboxylic groups, yet allowing for tunable optimization of their electronic and optical properties by selective substitution at one of the 4-4′ positions of a single bipyridine ligand with π-excessive heteroaromatic groups. We used Density Functional Theory/Time Dependent Density Functional Theory calculations to analyze the electronic structure and optical properties of the dye and to investigate the dye adsorption mode on a TiO 2 nanoparticle model. Our results show that we are effectively able to introduce three carboxylic anchoring units into the dye and achieve at the same time an enhanced dye light harvesting, demonstrating the design concept. As a drawback of this type of dyes, the synthesis leads to a mixture of dye isomers, which are rather tedious to separate. - Highlights: • We designed heteroleptic Ru(II) sensitizers with three carboxylic anchoring groups. • The three carboxylic anchoring groups are essential for high open circuit potentials. • Introduction of the mixed bipyridine ligand increases the dye light absorption. • Computational simulations confirm the three anchoring sites on TiO 2

  8. Design of Ru(II) sensitizers endowed by three anchoring units for adsorption mode and light harvesting optimization

    Energy Technology Data Exchange (ETDEWEB)

    Lobello, Maria Grazia; Fantacci, Simona [Computational Laboratory for Hybrid/Organic Photovoltaics (CLHYO), Istituto CNR di Scienze e Tecnologie Molecolari, Via elce di Sotto 8, I-06213 Perugia (Italy); Manfredi, Norberto; Coluccini, Carmine [Department of Materials Science and Milano-Bicocca Solar Energy Research Center-MIB-Solar, University of Milano-Bicocca and INSTM, Via Cozzi 53, I-20125 Milano (Italy); Abbotto, Alessandro, E-mail: alessandro.abbotto@unimib.it [Department of Materials Science and Milano-Bicocca Solar Energy Research Center-MIB-Solar, University of Milano-Bicocca and INSTM, Via Cozzi 53, I-20125 Milano (Italy); Nazeeruddin, Mohammed K., E-mail: mdkhaja.nazeeruddin@epfl.ch [Laboratory for Photonics and Interfaces, Station 6, Institute of Chemical Sciences and Engineering, School of Basic Sciences, Swiss Federal Institute of Technology, CH-1015 Lausanne (Switzerland); De Angelis, Filippo, E-mail: filippo@thch.unipg.it [Computational Laboratory for Hybrid/Organic Photovoltaics (CLHYO), Istituto CNR di Scienze e Tecnologie Molecolari, Via elce di Sotto 8, I-06213 Perugia (Italy)

    2014-06-02

    We report the design, synthesis and computational investigation of a class of Ru(II)-dyes based on mixed bipyridine ligands for use in dye-sensitized solar cells. These dyes are designed to preserve the optimal anchoring mode of the prototypical N719 sensitizer by three carboxylic groups, yet allowing for tunable optimization of their electronic and optical properties by selective substitution at one of the 4-4′ positions of a single bipyridine ligand with π-excessive heteroaromatic groups. We used Density Functional Theory/Time Dependent Density Functional Theory calculations to analyze the electronic structure and optical properties of the dye and to investigate the dye adsorption mode on a TiO{sub 2} nanoparticle model. Our results show that we are effectively able to introduce three carboxylic anchoring units into the dye and achieve at the same time an enhanced dye light harvesting, demonstrating the design concept. As a drawback of this type of dyes, the synthesis leads to a mixture of dye isomers, which are rather tedious to separate. - Highlights: • We designed heteroleptic Ru(II) sensitizers with three carboxylic anchoring groups. • The three carboxylic anchoring groups are essential for high open circuit potentials. • Introduction of the mixed bipyridine ligand increases the dye light absorption. • Computational simulations confirm the three anchoring sites on TiO{sub 2}.

  9. Reflecting metallic metasurfaces designed with stochastic optimization as waveplates for manipulating light polarization

    Science.gov (United States)

    Haberko, Jakub; Wasylczyk, Piotr

    2018-03-01

    We demonstrate that a stochastic optimization algorithm with a properly chosen, weighted fitness function, following a global variation of parameters upon each step can be used to effectively design reflective polarizing optical elements. Two sub-wavelength metallic metasurfaces, corresponding to broadband half- and quarter-waveplates are demonstrated with simple structure topology, a uniform metallic coating and with the design suited for the currently available microfabrication techniques, such as ion milling or 3D printing.

  10. Swertia chirayta, a Threatened High-Value Medicinal Herb: Microhabitats and Conservation Challenges in Sikkim Himalaya, India

    Directory of Open Access Journals (Sweden)

    Bharat Kumar Pradhan

    2015-11-01

    Full Text Available Assessing the impact of threats, identifying favorable growing conditions, and predicting future population scenarios are vital for the conservation and management of threatened species. This study investigated the availability, microhabitat characteristics, threat status, and community associations of Swertia chirayta, a highly threatened Himalayan medicinal herb, in 22 populations in Sikkim, India, using the vertical belt transect method. Of the 14 microhabitats identified, open grassy slope emerged as the most favorable and wet grassy slope as the least favorable for S. chirayta. The species was dominant in 8 of the 10 major plant communities identified. Among 9 major types of disturbance identified, human movement and collection of non-timber forest products appeared as the biggest threats to S. chirayta. Disturbances significantly affected the availability of the species. S. chirayta, though under high anthropogenic threat, maintains high microhabitat pliability, which is vital for its conservation and management, provided immediate conservation measures are taken.

  11. Ectomycorrhizal colonization of naturally regenerating Pinus sylvestris L. seedlings growing in different micro-habitats in boreal forest.

    Science.gov (United States)

    Iwański, Michał; Rudawska, Maria

    2007-07-01

    We investigated the species richness and composition of ectomycorrhizal (EM) fungi colonizing Pinus sylvestris L. seedlings naturally regenerating in boreal forest, in three different microhabitats: on forest ground, on decaying stumps, and within moss layer on erratic boulders. We tested the hypothesis that habitat differences would affect the composition of the EM community of regenerating pine seedlings. In total, 16 EM species were detected, from which none occurred on seedlings growing in all three microhabitats. Piloderma croceum and Cenococcum geophilum were common for seedlings growing in forest ground and on boulders, while Tricholoma aestuans and Suillus luteus were shared between seedlings growing on forest ground and decaying stumps. EM species richness and composition were strikingly different between seedlings regenerating in different microhabitats. Results are discussed as a function of dispersal and niche differentiation of EM fungi.

  12. Optimization of sensitometric properties of blue and green light sensitive dental radiographic films employing an automatic processor

    Directory of Open Access Journals (Sweden)

    Suchetha N Malleshi

    2011-01-01

    Full Text Available Background: Accurate film processing is of paramount importance in acquiring a good diagnostic radiograph. Radiographic films show variations in densities and contrast, with changes in processing conditions, and also film type, all of which are interdependent. Therefore, this research was conducted to recognize the effect of time and temperature variations of automatic processor on the sensitometric properties of blue and green light sensitive screen films. The study also aimed to note the effect on sensitometric properties when mismatch occurred when using between the screen and film belonging to different manufacturers. Materials and Methods: Sixty green light sensitive and 60 blue light sensitive spectrally matched screen film combinations were used in the study. However, the films and the intensifying screens employed belonged to different manufacturers. These films were exposed to five different exposure times and subsequently processed in an automatic processor, using two different protocols. Initially, at constant processing time of 2.5 min, five different processing temperatures were employed. Later, maintaining constant processing temperature of 35°C and five different processing times were engaged. Density, contrast and speed were calculated, using H and D curve. Results: Results revealed increasing density, contrast and speed values with increasing processing times and temperatures of both green and blue sensitive films. Conclusion: This investigation clearly establishes the possibility of obtaining optimal sensitometric properties, despite using intensifying screens and films of different manufacturers, if spectral match is ensured.

  13. Application of support vector regression for optimization of vibration flow field of high-density polyethylene melts characterized by small angle light scattering

    Science.gov (United States)

    Xian, Guangming

    2018-03-01

    In this paper, the vibration flow field parameters of polymer melts in a visual slit die are optimized by using intelligent algorithm. Experimental small angle light scattering (SALS) patterns are shown to characterize the processing process. In order to capture the scattered light, a polarizer and an analyzer are placed before and after the polymer melts. The results reported in this study are obtained using high-density polyethylene (HDPE) with rotation speed at 28 rpm. In addition, support vector regression (SVR) analytical method is introduced for optimization the parameters of vibration flow field. This work establishes the general applicability of SVR for predicting the optimal parameters of vibration flow field.

  14. Optimized Sensor Network and Multi-Agent Decision Support for Smart Traffic Light Management.

    Science.gov (United States)

    Cruz-Piris, Luis; Rivera, Diego; Fernandez, Susel; Marsa-Maestre, Ivan

    2018-02-02

    One of the biggest challenges in modern societies is to solve vehicular traffic problems. Sensor networks in traffic environments have contributed to improving the decision-making process of Intelligent Transportation Systems. However, one of the limiting factors for the effectiveness of these systems is in the deployment of sensors to provide accurate information about the traffic. Our proposal is using the centrality measurement of a graph as a base to locate the best locations for sensor installation in a traffic network. After integrating these sensors in a simulation scenario, we define a Multi-Agent Systems composed of three types of agents: traffic light management agents, traffic jam detection agents, and agents that control the traffic lights at an intersection. The ultimate goal of these Multi-Agent Systems is to improve the trip duration for vehicles in the network. To validate our solution, we have developed the needed elements for modelling the sensors and agents in the simulation environment. We have carried out experiments using the Simulation of Urban MObility (SUMO) traffic simulator and the Travel and Activity PAtterns Simulation (TAPAS) Cologne traffic scenario. The obtained results show that our proposal allows to reduce the sensor network while still obtaining relevant information to have a global view of the environment. Finally, regarding the Multi-Agent Systems, we have carried out experiments that show that our proposal is able to improve other existing solutions such as conventional traffic light management systems (static or dynamic) in terms of reduction of vehicle trip duration and reduction of the message exchange overhead in the sensor network.

  15. Optimized Sensor Network and Multi-Agent Decision Support for Smart Traffic Light Management

    Directory of Open Access Journals (Sweden)

    Luis Cruz-Piris

    2018-02-01

    Full Text Available One of the biggest challenges in modern societies is to solve vehicular traffic problems. Sensor networks in traffic environments have contributed to improving the decision-making process of Intelligent Transportation Systems. However, one of the limiting factors for the effectiveness of these systems is in the deployment of sensors to provide accurate information about the traffic. Our proposal is using the centrality measurement of a graph as a base to locate the best locations for sensor installation in a traffic network. After integrating these sensors in a simulation scenario, we define a Multi-Agent Systems composed of three types of agents: traffic light management agents, traffic jam detection agents, and agents that control the traffic lights at an intersection. The ultimate goal of these Multi-Agent Systems is to improve the trip duration for vehicles in the network. To validate our solution, we have developed the needed elements for modelling the sensors and agents in the simulation environment. We have carried out experiments using the Simulation of Urban MObility (SUMO traffic simulator and the Travel and Activity PAtterns Simulation (TAPAS Cologne traffic scenario. The obtained results show that our proposal allows to reduce the sensor network while still obtaining relevant information to have a global view of the environment. Finally, regarding the Multi-Agent Systems, we have carried out experiments that show that our proposal is able to improve other existing solutions such as conventional traffic light management systems (static or dynamic in terms of reduction of vehicle trip duration and reduction of the message exchange overhead in the sensor network.

  16. Development of a new light collection and detection system optimized for ion beam induced fluorescence microscopy

    International Nuclear Information System (INIS)

    Vanga, Sudheer Kumar; Mi, Zhaohong; Koh, Long Cheng; Tao, Ye; Bettiol, Andrew A.; Watt, Frank

    2015-01-01

    Ion beam induced fluorescence microscopy is a new imaging technique which has the potential to achieve sub-50 nm spatial resolution fluorescence images. Currently the resolution of the technique has been limited to around 150 nm mainly because of inefficient collection and detection of emitted photons from the sample. To overcome this limitation, a new light collection system based on a custom made parabolic mirror is employed to enhance the fluorescence collection. The custom made mirror is designed so as to obtain both structural (scanning transmission ion microscopy) and ion beam induced fluorescence imaging simultaneously. The design and characterization of the parabolic mirror is discussed in detail

  17. Signal optimization in urban transport: A totally asymmetric simple exclusion process with traffic lights.

    Science.gov (United States)

    Arita, Chikashi; Foulaadvand, M Ebrahim; Santen, Ludger

    2017-03-01

    We consider the exclusion process on a ring with time-dependent defective bonds at which the hopping rate periodically switches between zero and one. This system models main roads in city traffics, intersecting with perpendicular streets. We explore basic properties of the system, in particular dependence of the vehicular flow on the parameters of signalization as well as the system size and the car density. We investigate various types of the spatial distribution of the vehicular density, and show existence of a shock profile. We also measure waiting time behind traffic lights, and examine its relationship with the traffic flow.

  18. Seasonal Distribution and Diversity of Ground Arthropods in Microhabitats Following a Shrub Plantation Age Sequence in Desertified Steppe

    Science.gov (United States)

    Liu, Rentao; Zhu, Fan; Song, Naiping; Yang, Xinguo; Chai, Yongqing

    2013-01-01

    In desertified regions, shrub-dominated patches are important microhabitats for ground arthropod assemblages. As shrub age increases, soil, vegetation and microbiological properties can change remarkably and spontaneously across seasons. However, relatively few studies have analyzed how ground arthropods respond to the microhabitats created by shrubs of different plantation ages across seasons. Using 6, 15, 24 and 36 year-old plantations of re-vegetated shrubs (Caragana koushinskii) in the desert steppe of northwestern China as a model system, we sampled ground arthropod communities using a pitfall trapping method in the microhabitats under shrubs and in the open areas between shrubs, during the spring, summer and autumn. The total ground arthropod assemblage was dominated by Carabidae, Melolonthidae, Curculionidae, Tenebrionidae and Formicidae that were affected by plantation age, seasonal changes, or the interaction between these factors, with the later two groups also influenced by microhabitat. Overall, a facilitative effect was observed, with more arthropods and a greater diversity found under shrubs as compared to open areas, but this was markedly affected by seasonal changes. There was a high degree of similarity in arthropod assemblages and diversity between microhabitats in summer and autumn. Shrub plantation age significantly influenced the distribution of the most abundant groups, and also the diversity indices of the ground arthropods. However, there was not an overall positive relationship between shrub age and arthropod abundance, richness or diversity index. The influence of plantation age on arthropod communities was also affected by seasonal changes. From spring through summer to autumn, community indices of ground arthropods tended to decline, and a high degree of similarity in these indices (with fluctuation) was observed among different ages of shrub plantation in autumn. Altogether the recovery of arthropod communities was markedly affected by

  19. Soil bacterial and fungal community responses to nitrogen addition across soil depth and microhabitat in an arid shrubland

    Science.gov (United States)

    Mueller, Rebecca C.; Belnap, Jayne; Kuske, Cheryl R.

    2015-01-01

    Arid shrublands are stressful environments, typified by alkaline soils low in organic matter, with biologically-limiting extremes in water availability, temperature, and UV radiation. The widely-spaced plants and interspace biological soil crusts in these regions provide soil nutrients in a localized fashion, creating a mosaic pattern of plant- or crust-associated microhabitats with distinct nutrient composition. With sporadic and limited rainfall, nutrients are primarily retained in the shallow surface soil, patterning biological activity. We examined soil bacterial and fungal community responses to simulated nitrogen (N) deposition in an arid Larrea tridentata-Ambrosia dumosa field experiment in southern Nevada, USA, using high-throughput sequencing of ribosomal RNA genes. To examine potential interactions among the N application, microhabitat and soil depth, we sampled soils associated with shrub canopies and interspace biological crusts at two soil depths (0–0.5 or 0–10 cm) across the N-amendment gradient (0, 7, and 15 kg ha−1 yr−1). We hypothesized that localized compositional differences in soil microbiota would constrain the impacts of N addition to a microhabitat distribution that would reflect highly localized geochemical conditions and microbial community composition. The richness and community composition of both bacterial and fungal communities differed significantly by microhabitat and with soil depth in each microhabitat. Only bacterial communities exhibited significant responses to the N addition. Community composition correlated with microhabitat and depth differences in soil geochemical features. Given the distinct roles of soil bacteria and fungi in major nutrient cycles, the resilience of fungi and sensitivity of bacteria to N amendments suggests that increased N input predicted for many arid ecosystems could shift nutrient cycling toward pathways driven primarily by fungal communities.

  20. Soil bacterial and fungal community responses to nitrogen addition across soil depths and microhabitat in an arid shrubland

    Directory of Open Access Journals (Sweden)

    Rebecca C Mueller

    2015-09-01

    Full Text Available Arid shrublands are stressful environments, typified by alkaline soils low in organic matter, with biologically-limiting extremes in water availability, temperature and UV radiation. The widely-spaced plants and interspace biological soil crusts in these regions provide soil nutrients in a localized fashion, creating a mosaic pattern of plant- or crust-associated microhabitats with distinct nutrient composition. With sporadic and limited rainfall, nutrients are primarily retained in the shallow surface soil, patterning biological activity. We examined soil bacterial and fungal community responses to simulated nitrogen (N deposition in an arid Larrea tridentata-Ambrosia dumosa field experiment in southern Nevada, USA, using high-throughput sequencing of ribosomal RNA genes. To examine potential interactions among the N application, microhabitat and soil depth, we sampled soils associated with shrub canopies and interspace biological crusts at two soil depths (0-0.5 cm or 0-10 cm across the N-amendment gradient (0, 7 and 15 kg ha-1 yr-1. We hypothesized that localized compositional differences in soil microbiota would constrain the impacts of N addition to a microhabitat distribution that would reflect highly localized geochemical conditions and microbial community composition. The richness and community composition of both bacterial and fungal communities differed significantly by microhabitat and with soil depth in each microhabitat. Only bacterial communities exhibited significant responses to the N addition. Community composition correlated with microhabitat and depth differences in soil geochemical features. Given the distinct roles of soil bacteria and fungi in major nutrient cycles, the resilience of fungi and sensitivity of bacteria to N amendments suggests that increased N input predicted for many arid ecosystems could shift nutrient cycling toward pathways driven primarily by fungal communities.

  1. Realization of optimized quantum controlled-logic gate based on the orbital angular momentum of light.

    Science.gov (United States)

    Zeng, Qiang; Li, Tao; Song, Xinbing; Zhang, Xiangdong

    2016-04-18

    We propose and experimentally demonstrate an optimized setup to implement quantum controlled-NOT operation using polarization and orbital angular momentum qubits. This device is more adaptive to inputs with various polarizations, and can work both in classical and quantum single-photon regime. The logic operations performed by such a setup not only possess high stability and polarization-free character, they can also be easily extended to deal with multi-qubit input states. As an example, the experimental implementation of generalized three-qubit Toffoli gate has been presented.

  2. Spacing optimization of high power LED arrays for solid state lighting

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Y. Sing; Lee, S. W. Ricky, E-mail: rickylee@ust.hk [Electronic Packaging Laboratory, Center for Advanced Microsystems Packaging, Hong Kong University of Science and Technology (Hong Kong)

    2011-01-15

    This paper provides an analytical approach to determine the optimum pitch by utilizing a thermal resistance network, under the assumption of constant luminous efficiency. This work allows an LED array design which is mounted on a printed circuit board (PCB) attached with a heat sink subject to the natural convection cooling. Being validated by finite element (FE) models, the current approach can be shown as an effective method for the determination of optimal component spacing in an LED array assembly for SSL. (semiconductor devices)

  3. Study and optimization of the light-yield of a triple-GEM detector

    CERN Document Server

    Campagnola, Roberto; Mazzitelli, Giovanni

    The high-resolution tracking of low energy release particles had a remarkable development in recent years and will give a crucial contribution in different fields, from medical uses to those in dark matter search. Characteristics, such as high space and time resolution, low material budget, large volumes, low costs, make gas detectors ideal candidates for this type of devices. A very promising technique involves the optical reading of the light produced by the de-excitation of gas molecules during the processes of electron multiplication. This type of detector has been made possible thanks to the great progresses achieved in last years in the performance in micro pattern gas detector and in the evolution of the CMOS technology which led to the production of sensors able of offering high sensitivity and granularity combined with a very low noise level. In this thesis the performance of a prototype where the light is produced through the multiplication of electrons in a triple GEM structure and acquired by a c...

  4. Seasonal meso- and microhabitat selection by the northern snakehead (Channa argus) in the Potomac river system

    Science.gov (United States)

    Lapointe, N.W.R.; Thorson, J.T.; Angermeier, P.L.

    2010-01-01

     The northern snakehead (Channa argus) is a large piscivorous fish that is invasive in eastern Europe and has recently been introduced in North America. We examined the seasonal habitat selection at meso- and microhabitat scales using radio-telemetry to increase understanding of the ecology of this species, which will help to inform management decisions. After the spawning season (postspawn season, September–November), northern snakeheads preferred offshore Eurasian water-milfoil (Myriophyllum spicatum) beds with shallow water (∼115 cm) and soft substrate. In the winter (November–April), these fish moved to deeper water (∼135 cm) with warmer temperatures, but habitat selection was weak at both scales. Northern snakeheads returned to shallower water (∼95 cm) in the prespawn season (April–June) and used milfoil and other cover. Habitat selection was the strongest at both meso- and microhabitat scales during the spawning season (June–September), when fish preferred macrophytes and cover in shallow water (∼88 cm). Our results help to identify habitats at the risk of invasion by northern snakeheads. We suggest that control efforts and future research focus on shallow waters, and take into consideration the seasonal habitat preferences.

  5. Microhabitat and biology of Sphaerium striatinum in a central New York stream

    Science.gov (United States)

    Dittman, Dawn E.; Johnson, James H.; Nack, Christopher C.

    2018-01-01

    In many lotic systems, drastic declines in freshwater bivalve populations, including fingernail clams (Sphaeriidae), have created concerns about biodiversity and future ecosystem services. We examined the local occurrence of the historically common fingernail clam, Sphaerium striatinum, in a central New York stream. We sampled the density of sphaeriids and measured the associated habitat variables (substrate, depth, water flow) to test within-stream multivariate benthic microhabitat association. Size distribution, density, and diel feeding periodicity were measured as focal aspects of fingernail clam biology and ecology. S. striatinum tended to be found in microhabitats that had harder substrates and faster flow. The Labrador Creek fingernail clam local population had positive indicators (size distribution, density). There was significant diel periodicity in feeding behavior. The clams fed most actively during the 0400–0800 h periods. This kind of behavioral periodicity can indicate a significant ecological interaction between predators and bivalve prey. Increased understanding of the behavioral ecology of small native freshwater bivalves in an unimpacted headwater stream is a fundamental building block for development of overall ecological conservation goals for freshwater bivalves and their lotic habitats.

  6. Tree microhabitat structures as indicators of biodiversity in Douglas-fir forests of different stand ages and management histories in the Pacific Northwest, U.S.A.

    Science.gov (United States)

    Alexa K. Michel; Susanne. Winter

    2009-01-01

    In this study, microhabitat structures in Douglas-fir (Pseudotsuga menziesii) forests were defined and their frequency and abundance in natural stands and stands of varying active management histories and stand ages was compared. Indicator microhabitat structures for natural forests were determined and the relationship of the abundance of...

  7. The diversity of microhabitats and their impact on the regeneration of spruce and rowan in the mountain forests of the Low Tatras

    International Nuclear Information System (INIS)

    Gloncak, P.

    2010-01-01

    In this paper the authors describe the questions: what is proportion of different types of microhabitats in natural spruce?; which types of microhabitats prefers spruce (Picea abies) and rowan (Sorbus aucuparia) in the early stages of their development?; what role do ground vegetation and dead wood play?

  8. The diversity of microhabitats and their impact on the regeneration of spruce and rowan in the mountain forests of the Low Tatras

    International Nuclear Information System (INIS)

    Gloncak, P.

    2010-01-01

    In this presentation the authors describe the questions: what is proportion of different types of microhabitats in natural spruce?; which types of microhabitats prefers spruce (Picea abies) and rowan (Sorbus aucuparia) in the early stages of their development?; what role do ground vegetation and dead wood play?

  9. Trophic and microhabitat niche overlap in two sympatric dendrobatids from La Selva, Costa Rica

    Directory of Open Access Journals (Sweden)

    Cajade, Rodrigo

    2010-11-01

    both dendrobatids were recorded by the analysed stomach flushing technique. Microhabitats uses were defined as the site where each individual was captured. The influence of microhabitat on diets was evaluated by the dietary (prey proportions and volume and microhabitat overlapsusing Pianka’s (Ojk overlap index calculated with EcoSim software. Diets of both dendrobatids were principally characterized by the preference of hymenopterans (ants, acarines and collembolans, resulted in a high overlapping in prey proportions and prey volume. However, diets overlaps were not significant, suggesting the absence of negative feeding interactions.Microhabitat use was low overlapped and also not significant, suggesting a differentiation on theuse of spatial resource. The absence of negative feeding interactions between Dendrobates auratus and Oophaga pumilio could be due to segregation in microhabitat use and possible by the abundance of trophic resource in the area. The great large volumes of formicids andacarines in the diet of this dendrobatids are in agreement with the hypothesis of these arthropods as a dietary source of alkaloids.

  10. Semiconductor heterostructures and optimization of light-trapping structures for efficient thin-film solar cells

    International Nuclear Information System (INIS)

    McPheeters, Claiborne O; Yu, Edward T; Hu, Dongzhi; Schaadt, Daniel M

    2012-01-01

    Sub-wavelength photonic structures and nanoscale materials have the potential to greatly improve the efficiencies of solar cells by enabling maximum absorption of sunlight. Semiconductor heterostructures provide versatile opportunities for improving absorption of infrared radiation in photovoltaic devices, which accounts for half of the power in the solar spectrum. These ideas can be combined in quantum-well solar cells and related structures in which sub-wavelength metal and dielectric scattering elements are integrated for light trapping. Measurements and simulations of GaAs solar cells with less than one micron of active material demonstrate the benefits of incorporating In(Ga)As quantum-wells and quantum-dots to improve their performance. Simulations that incorporate a realistic model of absorption in quantum-wells show that the use of broadband photonic structures with such devices can substantially improve the benefit of incorporating heterostructures, enabling meaningful improvements in their performance

  11. Study of organic light emitting devices (OLEDs) with optimal emission efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Jai [School of Engineering and IT, B-purple 12, Faculty of EHS, Charles Darwin University, Darwin, NT 0909 (Australia)

    2010-04-15

    The external emission efficiency of organic light emitting devices (OLEDs) is analysed by studying the rate of spontaneous emission of both singlet and triplet excitons and their corresponding radiative lifetimes. Rates of spontaneous emissions are calculated from the first order perturbation theory using the newly discovered time-dependent spin-orbit-exciton-photon interaction operator as the perturbation operator. It is clearly shown how the new interaction operator is responsible for attracting triplet excitons to a phosphor (heavy metal atom) and then it flips the spins to a singlet configuration. Thus, the spin forbidden transition becomes spin allowed. Calculated rates agree with the experimental results qualitatively. Results are of general interests for OLED studies. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  12. Optimization of light out-coupling in optoelectronic devices using nanostructured surface

    DEFF Research Database (Denmark)

    Ou, Haiyan; Ou, Yiyu; Argyraki, Aikaterini

    C and GaN, these developed methods could be applied to other semicon ductors such as Si, etc. Furthermore, all optoelectronic devices having an optical interface such as solar cells, photo - detectors, could benefit from these developed methods for opto - electronic performance improvement....... the overall efficiency of the LEDs. In this paper we have developed various methods for two important semiconductors: silicon carbide (SiC) and gallium nitride (GaN), and demonstrated enormous extraction efficiency enhancement. SiC is an important su bstrate for LED devices. It has refractive index of 2.......6, and only a few percent of light could escape from it. We have developed periodic nanocone structures by using electron - beam lithography, periodic nanodome structures by using nanosphere lithography, random nanostructures by using self - assembled metal nanoparticles, and random nanostructures by directly...

  13. Optimization of the implosion phase on TC-I by light emission analysis

    International Nuclear Information System (INIS)

    Aramaki, E.A.; Porto, P.; Berni, L.; Honda, R.Y.; Ueda, M.; Doi, I.; Machid, M.

    1988-01-01

    The best operation condition on the field-reversed theta-pinch TC-I at UNICAMP is studied by analysis of the helium-plasma light emission and electromagnetic signals observed during the preionization and implosion phase of FRC plasma. The TC-I device can be operated with a crowbar switch on the preionization and main capacitor banks, in order to fix the number of oscillations as well as the time interval between the end of the preionization and the main discharge phase. A detailed study of the plasma implosion has been carried out by changing the above parameters and also the working gas pressure by using photodiode, a visible spectrometer, magnetic probes, a Faraday cup and a streak camera [pt

  14. Optimization of the implosion phase of TC-I by light emission analysis

    International Nuclear Information System (INIS)

    Aramaki, E.A.; Porto, P.; Berni, L.; Honda, R.Y.; Ueda, M.; Doi, I.; Machida, M.

    1989-01-01

    The best operation condition on the field-reversed theta-pinch TC-I at UNICAMP is studied by analysis of the helium-plasma light emission and electromagnetic signals observed during the preionization and implosion phase of FRC plasma. The TC-I device can be operated with a crowbar switch on the preionization and main capacitor banks, in order to fix the number of oscillations as well as the time interval between the end of the preionization and the main discharge phase. A detailed study of the plasma implosion has been carried out by changing the above parameters and also the working gas pressure by using a photodiode, a visible spectrometer, magnetic probes, a Faraday cup and a streak camera. (orig.)

  15. A Systematic Approach to the Design Optimization of Light-Absorbing Indenofluorene Polymers for Organic Photovoltaics

    KAUST Repository

    Kirkpatrick, James

    2012-01-09

    The synthesis and optimization of new photovoltaic donor polymers is a time-consuming process. Computer-based molecular simulations can narrow the scope of materials choice to the most promising ones, by identifying materials with desirable energy levels and absorption energies. In this paper, such a retrospective analysis is presented of a series of fused aromatic push-pull copolymers. It is demonstrated that molecular calculations do indeed provide good estimates of the absorption energies measured by UV-vis spectroscopy and of the ionization potentials measured by photoelectron spectroscopy in air. Comparing measured photovoltaic performance of the polymer series to the trend in efficiencies predicted by computation confirms the validity of this approach. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Theory for optimal design of waveguiding light concentrators in photovoltaic microcell arrays.

    Science.gov (United States)

    Semichaevsky, Andrey V; Johnson, Harley T; Yoon, Jongseung; Nuzzo, Ralph G; Li, Lanfang; Rogers, John

    2011-06-10

    Efficiency of ultrathin flexible solar photovoltaic silicon microcell arrays can be significantly improved using nonimaging solar concentrators. A fluorophore is introduced to match the solar spectrum and the low-reflectivity wavelength range of Si, reduce the escape losses, and allow the nontracking operation. In this paper we optimize our solar concentrators using a luminescent/nonluminescent photon transport model. Key modeling results are compared quantitatively to experiments and are in good agreement with the latter. Our solar concentrator performance is not limited by the dye self-absorption. Bending deformations of the flexible solar collectors do not result in their indirect gain degradation compared to flat solar concentrators with the same projected area.

  17. Optimization of Nanocomposite Solar Cell/Liquid Crystal Matrix to Diminish High Intensity Laser Light Relevant to Aviation Safety Applications

    Science.gov (United States)

    Hofmann, James A.

    An increasing threat to the aviation industry is laser light illumination on airplanes during critical phases of flight. If a laser hits the cockpit, it not only distracts the pilots, but it can cause flash blindness or permanently damage the vision of the pilots. This research attempts to mitigate these lasers illuminations through the application of both liquid crystal (LC's) technologies and dye sensitized solar cell (DSSC) technologies. The LC of choice is N-(4-Methoxybenzylidene)-4-butylaniline, or MBBA, because it has special optical properties including the ability to undergo phase transitions when exposed to an electric field. By applying an external electric field, MBBA switches from its transparent nematic phase, to its non-transparent crystalline phase, blocking the laser light. This research optimized the application of MBBA by reducing the triggering voltage and relaxation time of the LC using spacer thicknesses and scratching techniques. The liquid to solid phase transition was reduced to a 3V differential, and the time required for the crystals to relax into its transparent liquid phase was reduced to less than ten seconds. The phase transition was studied using an external electric field generated by DSSCs constructed from a titanium dioxide (TiO2) nanocomposite layer coated with dye. To maximize the voltage output by the DSSCs, layer thickness and dye sensitizer were studied to investigate their impact on the performance of the DSSC when illuminated by solar lamps and green light (532nm). Three different layer thicknesses and five different dyes were tested: Eosin Y, Eriochrome Black, Congo Red, Fast Green, and Alizarine Yellow. The experimental results showed a thin layer of nanocomposite sensitized with Eosin Y dye produced the most efficient DSSCs for the scope of this research. Experimental testing showed the DSSCs can generate 381 +/- 10mV under solar lamp exposure, 356 +/- 10mV under laser light exposure, and a voltage increase of 60 +/- 16m

  18. Hybridization of tensor-optimized and high-momentum antisymmetrized molecular dynamics for light nuclei with bare interaction

    Science.gov (United States)

    Lyu, Mengjiao; Isaka, Masahiro; Myo, Takayuki; Toki, Hiroshi; Ikeda, Kiyomi; Horiuchi, Hisashi; Suhara, Tadahiro; Yamada, Taiichi

    2018-01-01

    Many-body correlations play an essential role in the ab initio description of nuclei with nuclear bare interactions. We propose a new framework to describe light nuclei by the hybridization of the tensor-optimized antisymmetrized molecular dynamics (TOAMD) and the high-momentum AMD (HM-AMD), which we call "HM-TOAMD." In this framework, we describe the many-body correlations in terms of not only the correlation functions in TOAMD, but also the high-momentum pairs in the AMD wave function. With the bare nucleon-nucleon interaction AV8^', we sufficiently reproduce the energy and radius of the {^3}H nucleus in HM-TOAMD. The effects of tensor force and short-range repulsion in the bare interaction are nicely described in this new framework. We also discuss the convergence in calculation and flexibility of the model space for this new method.

  19. Determination of an optimized Alq3 layer thickness in organic light-emitting diodes by using microcavity effects

    International Nuclear Information System (INIS)

    Jung, Boo-Young; Hwangbo, Chang-Kwon

    2006-01-01

    In this paper, an optical model of an organic light-emitting diode (OLED) based on the optical thin film theory is derived to calculate the output intensity of a small-molecule OLED. Two types of Alq 3 -based OLEDs are designed using the optical model and deposited to compare with the designed OLEDs. The optical model shows that the radiance of the OLED can be affected by the Fabry-Perot multiple beam interference effect, the two-beam interference effect, and the spontaneous emission spectrum of the emitting material. The measured spectral characteristics for the two types of OLEDs are found to be in good agreement with the simulation. The result suggests that the proposed optical model can be used for optimizing the architecture of small-molecule OLEDs.

  20. An Optimized Low-Charge Configuration of the LINAC Coherent Light Source

    CERN Document Server

    Emma, Paul; Huang, Zhirong; Limborg-Deprey, Cecile; Reiche, Sven; Wu, Juhao; Zolotorev, Max S

    2005-01-01

    The Linac Coherent Light Source (LCLS) is an x-ray free-electron laser (FEL) project based on the SLAC linac. The nominal parameter set is founded on a 1-nC bunch charge and normalized emittance of about 1 micron. The most challenging issues, such as emittance generation, wakefields, and coherent synchrotron radiation (CSR), are associated with the high bunch charge. In the LCLS in particular, with its strong linac wakefields, the bunch compression process produces sharp temporal horns at the head and tail of the bunch with degraded local emittance, effectively wasting much of the charge. The sharp horns intensify CSR in the bends and further drive a strong resistive-wall wakefield in the long FEL undulator. Although these issues are not insurmountable, they suggest a lower bunch charge may be more suitable. This study uses a 0.2-nC bunch charge and 0.85-micron emittance with only 30 A of peak current in the injector, producing the same FEL saturation length. The resulting performance is more stable, has negl...

  1. Structural design and optimization of near-ultraviolet light-emitting diodes with wide wells

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Yen-Kuang, E-mail: ykuo@cc.ncue.edu.tw [Department of Physics, National Changhua University of Education, Changhua 500, Taiwan (China); Chen, Fang-Ming [Institute of Photonics, National Changhua University of Education, Changhua 500, Taiwan (China); Chang, Jih-Yuan [Center for Teacher Education, National Changhua University of Education, Changhua 500, Taiwan (China); Shih, Ya-Hsuan [Department of Photonics, National Cheng Kung University, Tainan 701, Taiwan (China)

    2016-03-07

    The characteristics of the near-ultraviolet (NUV) light-emitting diodes (LEDs) with wide (14-nm-thick) and narrow (2-nm-thick) wells under the situations of different numbers of wells and degree of polarization are systematically investigated. The simulation results show that the Auger recombination can be efficiently suppressed with the increase of number of wells in NUV LEDs. For the LEDs with wide wells, the quantum-confined Stark effect and Shockley–Read–Hall recombination play an important role when the number of wells increases, especially when the LED is under low current injection or high degree of polarization. In order to take the advantage of using wide wells, it is proposed that the quaternary Al{sub 0.1}In{sub 0.05}Ga{sub 0.85}N barriers be used in wide-well NUV LEDs along with the use of Al{sub 0.3}Ga{sub 0.7}N/Al{sub 0.1}Ga{sub 0.9}N superlattice electron-blocking layer to mitigate the polarization effect and electron overflow. With this band-engineering structural design, the optical performance of the wide-well NUV LEDs is much better than its thin-well counterpart even under the situation of high degree of polarization.

  2. Optimization of white organic light emitting diodes based on emitting layer charge carrier conduction properties

    International Nuclear Information System (INIS)

    Baek, H I; Lee, C H

    2008-01-01

    We have fabricated white organic light emitting diodes (OLEDs) with multi-emitting layer (EML) structures in which 4,4'-N,N'-dicarbazole-biphenyl (CBP) layers doped with the phosphorescent dopants fac-tris(2-phenylpyridine) iridium (Ir(ppy) 3 ) and bis(2-(2'-benzo[4,5-a]thienyl)pyridinato-N,C3')iridium(acetylacetonate) (btp 2 Ir(acac)) and the fluorescent dopant 4,4'-bis[2-{4-(N,N-diphenylamino) phenyl}vinyl]biphenyl (DPAVBi) were used as green (G), red (R) and blue (B) EMLs, respectively. A higher efficiency was expected with the R/G/B EML sequence from the hole transport layer interface than with the G/R/B sequence because of the differences in the charge carrier conduction properties of the EMLs doped with phosphorescent dopants and the luminance balance between the phosphorescent and fluorescent emissions. A high efficiency of 18.3 cd A -1 (an external quantum efficiency of 8.5%) at 100 cd m -2 and good colour stability were achieved with the R/G/B EML sequence as expected, with an additional non-doped CBP interlayer used between the G and B EMLs. In addition, the OLED with this sequence was found to have the longest lifetime of the white devices we tested

  3. Optimization of white organic light emitting diodes based on emitting layer charge carrier conduction properties

    Energy Technology Data Exchange (ETDEWEB)

    Baek, H I; Lee, C H [School of Electrical Engineering and Computer Science and Inter-University Semiconductor Research Center, Seoul National University, Seoul 151-744 (Korea, Republic of)], E-mail: hibaek75@snu.ac.kr

    2008-05-21

    We have fabricated white organic light emitting diodes (OLEDs) with multi-emitting layer (EML) structures in which 4,4'-N,N'-dicarbazole-biphenyl (CBP) layers doped with the phosphorescent dopants fac-tris(2-phenylpyridine) iridium (Ir(ppy){sub 3}) and bis(2-(2'-benzo[4,5-a]thienyl)pyridinato-N,C3')iridium(acetylacetonate) (btp{sub 2}Ir(acac)) and the fluorescent dopant 4,4'-bis[2-{l_brace}4-(N,N-diphenylamino) phenyl{r_brace}vinyl]biphenyl (DPAVBi) were used as green (G), red (R) and blue (B) EMLs, respectively. A higher efficiency was expected with the R/G/B EML sequence from the hole transport layer interface than with the G/R/B sequence because of the differences in the charge carrier conduction properties of the EMLs doped with phosphorescent dopants and the luminance balance between the phosphorescent and fluorescent emissions. A high efficiency of 18.3 cd A{sup -1} (an external quantum efficiency of 8.5%) at 100 cd m{sup -2} and good colour stability were achieved with the R/G/B EML sequence as expected, with an additional non-doped CBP interlayer used between the G and B EMLs. In addition, the OLED with this sequence was found to have the longest lifetime of the white devices we tested.

  4. Superior light metals by texture engineering: Optimized aluminum and magnesium alloys for automotive applications

    International Nuclear Information System (INIS)

    Hirsch, J.; Al-Samman, T.

    2013-01-01

    Aluminum and magnesium are two highly important lightweight metals used in automotive applications to reduce vehicle weight. Crystallographic texture engineering through a combination of intelligent processing and alloying is a powerful and effective tool to obtain superior aluminum and magnesium alloys with optimized strength and ductility for automotive applications. In the present article the basic mechanisms of texture formation of aluminum and magnesium alloys during wrought processing are described and the major aspects and differences in deformation and recrystallization mechanisms are discussed. In addition to the crystal structure, the resulting properties can vary significantly, depending on the alloy composition and processing conditions, which can cause drastic texture and microstructure changes. The elementary mechanisms of plastic deformation and recrystallization comprising nucleation and growth and their orientation dependence, either within the homogeneously formed microstructure or due to inhomogeneous deformation, are described along with their impact on texture formation, and the resulting forming behavior. The typical face-centered cubic and hexagonal close-packed rolling and recrystallization textures, and related mechanical anisotropy and forming conditions are analyzed and compared for standard aluminum and magnesium alloys. New aspects for their modification and advanced strategies of alloy design and microstructure to improve material properties are derived

  5. Toward optimized light utilization in nanowire arrays using scalable nanosphere lithography and selected area growth.

    Science.gov (United States)

    Madaria, Anuj R; Yao, Maoqing; Chi, Chunyung; Huang, Ningfeng; Lin, Chenxi; Li, Ruijuan; Povinelli, Michelle L; Dapkus, P Daniel; Zhou, Chongwu

    2012-06-13

    Vertically aligned, catalyst-free semiconducting nanowires hold great potential for photovoltaic applications, in which achieving scalable synthesis and optimized optical absorption simultaneously is critical. Here, we report combining nanosphere lithography (NSL) and selected area metal-organic chemical vapor deposition (SA-MOCVD) for the first time for scalable synthesis of vertically aligned gallium arsenide nanowire arrays, and surprisingly, we show that such nanowire arrays with patterning defects due to NSL can be as good as highly ordered nanowire arrays in terms of optical absorption and reflection. Wafer-scale patterning for nanowire synthesis was done using a polystyrene nanosphere template as a mask. Nanowires grown from substrates patterned by NSL show similar structural features to those patterned using electron beam lithography (EBL). Reflection of photons from the NSL-patterned nanowire array was used as a measure of the effect of defects present in the structure. Experimentally, we show that GaAs nanowires as short as 130 nm show reflection of <10% over the visible range of the solar spectrum. Our results indicate that a highly ordered nanowire structure is not necessary: despite the "defects" present in NSL-patterned nanowire arrays, their optical performance is similar to "defect-free" structures patterned by more costly, time-consuming EBL methods. Our scalable approach for synthesis of vertical semiconducting nanowires can have application in high-throughput and low-cost optoelectronic devices, including solar cells.

  6. Characterization and optimization of an inkjet-printed smart textile UV-sensor cured with UV-LED light

    Science.gov (United States)

    Seipel, S.; Yu, J.; Periyasamy, A. P.; Viková, M.; Vik, M.; Nierstrasz, V. A.

    2017-10-01

    For the development of niche products like smart textiles and other functional high-end products, resource-saving production processes are needed. Niche products only require small batches, which makes their production with traditional textile production techniques time-consuming and costly. To achieve a profitable production, as well as to further foster innovation, flexible and integrated production techniques are a requirement. Both digital inkjet printing and UV-light curing contribute to a flexible, resource-efficient, energy-saving and therewith economic production of smart textiles. In this article, a smart textile UV-sensor is printed using a piezoelectric drop-on-demand printhead and cured with a UV-LED lamp. The UVcurable ink system is based on free radical polymerization and the integrated UVsensing material is a photochromic dye, Reversacol Ruby Red. The combination of two photoactive compounds, for which UV-light is both the curer and the activator, challenges two processes: polymer crosslinking of the resin and color performance of the photochromic dye. Differential scanning calorimetry (DSC) is used to characterize the curing efficiency of the prints. Color measurements are made to determine the influence of degree of polymer crosslinking on the developed color intensities, as well as coloration and decoloration rates of the photochromic prints. Optimized functionality of the textile UV-sensor is found using different belt speeds and lamp intensities during the curing process.

  7. Analysis and optimization of the heat-insulating light concrete hollow brick walls design by the finite element method

    Energy Technology Data Exchange (ETDEWEB)

    Coz Diaz, J.J. del; Betegon Biempica, C.; Prendes Gero, M.B. [Edificio Departamental Viesques, No 7, 33204 Gijon (Asturias) (Spain); Garcia Nieto, P.J. [Departamento de Matematicas, Facultad de Ciencias, C/Calvo Sotelo s/n, 33007 Oviedo (Asturias) (Spain)

    2007-06-15

    Department of Public Works, owners and building proprietors are demanding high-capacity heat-insulating exterior masonry components specifically for further energy savings. For housing and industrial structures there is also a great interest in light building materials with good physical material behaviour, with respect to an energy conscious and ecological design, which fulfils all strength and serviceability requirements. The major variables influencing the thermal conductivity of masonry materials are illustrated in this work by taking blocks made from no-fine lightweight concrete and different mortar properties. The finite element method (FEM) is used for finding accurate solutions of the heat transfer equation for five different light concrete hollow brick walls. Mathematically, the non-linearity is due to the radiation boundary condition inside the inner recesses of the bricks. The conduction and convection phenomena are taking into account in this study for three different values of the mortar conductivity and three different values for the bricks. Optimization of the walls is carried out from the finite element analysis of five hollow brick geometries by means of the mass overall thermal efficiency and the equivalent thermal conductivity. Finally, conclusions of this work are exposed. (author)

  8. Analysis and optimization of the heat-insulating light concrete hollow brick walls design by the finite element method

    International Nuclear Information System (INIS)

    Coz Diaz, J.J. del; Garcia Nieto, P.J.; Betegon Biempica, C.; Prendes Gero, M.B.

    2007-01-01

    Department of Public Works, owners and building proprietors are demanding high-capacity heat-insulating exterior masonry components specifically for further energy savings. For housing and industrial structures there is also a great interest in light building materials with good physical material behaviour, with respect to an energy conscious and ecological design, which fulfils all strength and serviceability requirements. The major variables influencing the thermal conductivity of masonry materials are illustrated in this work by taking blocks made from no-fine lightweight concrete and different mortar properties. The finite element method (FEM) is used for finding accurate solutions of the heat transfer equation for five different light concrete hollow brick walls. Mathematically, the non-linearity is due to the radiation boundary condition inside the inner recesses of the bricks. The conduction and convection phenomena are taking into account in this study for three different values of the mortar conductivity and three different values for the bricks. Optimization of the walls is carried out from the finite element analysis of five hollow brick geometries by means of the mass overall thermal efficiency and the equivalent thermal conductivity. Finally, conclusions of this work are exposed

  9. Detector optimization studies and light Higgs decay into muons at CLIC

    Energy Technology Data Exchange (ETDEWEB)

    Grefe, Christian

    2013-09-15

    The Compact Linear Collider (CLIC) is a concept for a future e{sup +}e{sup -} linear collider with a center-of-mass energy of up to 3 TeV. The design of a CLIC experiment is driven by the requirements related to the physics goals, as well as by the experimental conditions. For example, the short time between two bunch crossings of 0.5 ns and the backgrounds due to beamstrahlung have direct impact on the design of a CLIC experiment. The Silicon Detector (SiD) is one of the concepts currently being discussed as a possible detector for the International Linear Collider (ILC). In this thesis we develop a modified version of the SiD simulation model for CLIC, taking into account the specific experimental conditions. In addition, we developed a software tool to investigate the impact of beam-related backgrounds on the detector by overlaying events from different simulated event samples. Moreover, we present full simulation studies, determining the performance of the calorimeter and tracking systems. We show that the track reconstruction in the all-silicon tracker of SiD is robust in the presence of the backgrounds at CLIC. Furthermore, we investigate tungsten as a dense absorber material for the hadronic calorimeter, which allows for the construction of a compact hadronic calorimeter that fulfills the requirements on the energy resolution and shower containment without a significant increase of the coil radius. Finally, the measurement of the decays of light Higgs bosons into two muons is studied in full simulation. We find that with an integrated luminosity of 2 ab{sup -1}, corresponding to 4 years of data taking at CLIC, the respective Higgs branching ratio can be determined with a statistical uncertainty of approximately 15%.

  10. Detector optimization studies and light Higgs decay into muons at CLIC

    International Nuclear Information System (INIS)

    Grefe, Christian

    2013-09-01

    The Compact Linear Collider (CLIC) is a concept for a future e + e - linear collider with a center-of-mass energy of up to 3 TeV. The design of a CLIC experiment is driven by the requirements related to the physics goals, as well as by the experimental conditions. For example, the short time between two bunch crossings of 0.5 ns and the backgrounds due to beamstrahlung have direct impact on the design of a CLIC experiment. The Silicon Detector (SiD) is one of the concepts currently being discussed as a possible detector for the International Linear Collider (ILC). In this thesis we develop a modified version of the SiD simulation model for CLIC, taking into account the specific experimental conditions. In addition, we developed a software tool to investigate the impact of beam-related backgrounds on the detector by overlaying events from different simulated event samples. Moreover, we present full simulation studies, determining the performance of the calorimeter and tracking systems. We show that the track reconstruction in the all-silicon tracker of SiD is robust in the presence of the backgrounds at CLIC. Furthermore, we investigate tungsten as a dense absorber material for the hadronic calorimeter, which allows for the construction of a compact hadronic calorimeter that fulfills the requirements on the energy resolution and shower containment without a significant increase of the coil radius. Finally, the measurement of the decays of light Higgs bosons into two muons is studied in full simulation. We find that with an integrated luminosity of 2 ab -1 , corresponding to 4 years of data taking at CLIC, the respective Higgs branching ratio can be determined with a statistical uncertainty of approximately 15%.

  11. Optimization of low-level light therapy's illumination parameters for spinal cord injury in a rat model

    Science.gov (United States)

    Shuaib, Ali; Bourisly, Ali

    2018-02-01

    Spinal cord injury (SCI) can result in complete or partial loss of sensation and motor function due to interruption along the severed axonal tract(s). SCI can result in tetraplegia or paraplegia, which can have prohibitive lifetime medical costs and result in shorter life expectancy. A promising therapeutic technique that is currently in experimental phase and that has the potential to be used to treat SCI is Low-level light therapy (LLLT). Preclinical studies have shown that LLLT has reparative and regenerative capabilities on transected spinal cords, and that LLLT can enhance axonal sprouting in animal models. However, despite the promising effects of LLLT as a therapy for SCI, it remains difficult to compare published results due to the use of a wide range of illumination parameters (i.e. different wavelengths, fluences, beam types, and beam diameter), and due to the lack of a standardized experimental protocol(s). Before any clinical applications of LLLT for SCI treatment, it is crucial to standardize illumination parameters and efficacy of light delivery. Therefore, in this study we aim to evaluate the light fluence distribution on a 3D voxelated SCI rat model with different illumination parameters (wavelengths: 660, 810, and 980 nm; beam types: Gaussian and Flat; and beam diameters: 0.1, 0.2, and 0.3 cm) for LLLT using Monte Carlo simulation. This study provides an efficient approach to guide researchers in optimizing the illumination parameters for LLLT spinal cord injury in an experimental model and will aid in quantitative and qualitative standardization of LLLT-SCI treatment.

  12. By the Light of the Moon: North Pacific Dolphins Optimize Foraging with the Lunar Cycle

    Science.gov (United States)

    Simonis, Anne Elizabeth

    Islands can likely be attributed to the presence of distinct populations or social clusters with dissimilar foraging strategies. Consistent observations of reduced acoustic activity during times of increased lunar illumination show that the lunar cycle is an important predictor for nocturnal dolphin foraging behavior. The result of this research advances the scientific understanding of how dolphins optimize their foraging behavior in response to the changing distribution and abundance of their prey.

  13. Microhabitat preference of Anisakis simplex in three salmonid species

    DEFF Research Database (Denmark)

    Bahlool, Qusay Zuhair Mohammad; Skovgaard, Alf; Kania, Per Walter

    2012-01-01

    . simplex larvae were attached to the digestive tract (stomach, pyloric caeca, intestine), while the majority of larvae found in rainbow trout were located between the pyloric caeca. In Baltic salmon, nematodes were dispersed in and on spleen, head kidney, liver, swim bladder and musculature. Encapsulation...... differed between species. S. salar (Baltic salmon) showed the highest number of successfully established nematodes, whereas S. trutta (brown trout) and O. mykiss (rainbow trout) had a higher natural resistance. Microhabitat selection of nematodes differed according to fish species. In brown trout, A...... reactions for IgM-bearing cells in the inflammatory tissue connected with nematodes. CD8+ cells were detected in all three species and MHCII-bearing cells were found associated with encapsulated A. simplex in rainbow trout and brown trout, but not in Baltic salmon. Physiological, immunological...

  14. Microhabitat preference of Anisakis simplex in 3 salmonid species: Immunological Implications

    DEFF Research Database (Denmark)

    Bahlool, Qusay Zuhair Mohammad; Buchmann, Kurt

    Third stage larvae of Anisakis simplex nematodes are considered to have a low host-specificity and are able to infect a wide range of fish species. However, the physiological and immunological status of the fish species may affect the fate of the worm following infection. We selected three...... different salmonid species to investigate the in vivo behavioural difference of experimentally inoculated Anisakis parasite inside these fishes. Rainbow trout (Oncorhynchus mykiss), Baltic salmon (Salmo salar) and brown trout (Salmo trutta) were used in this experiment. Infection success differed between...... species. Baltic salmon showed a higher number of nematodes successfully established, whereas brown trout and rainbow trout showed a higher natural resistance. Microhabitat results were also different according to the fish species. Anisakis simplex found in brown trout where attached to the digestive tract...

  15. Microhabitats occupied by Myxomycetes in the Brazilian Atlantic Forest: Heliconiaceae inflorescences.

    Science.gov (United States)

    Cavalcanti, L H; Ferreira, I N; Bezerra, A C C; Costa, A A A

    2015-11-01

    The occurrence of Myxomycetes in Heliconia psittacorum L.f. inflorescences was researched within four conservation units located in Northeast Brazil, aiming at evaluating the occupation of this microhabitat in fragments of Atlantic Forest along an altitude between 30-750 m. Inflorescences attached to the plant were examined; dead flowers and bracts were collected to assemble moist chambers (368). Four families, four genera and 10 species were recorded. A preference was evidenced for a basic pH substrate and a predominance of calcareous species (5:1). The composition of the myxobiota in fragments pertaining to altitudes above 400 m was similar and differed significantly from the one found in fragments of lowland forests (<100 m). Physarum compressum and Arcyria cinerea are the most characteristic species of the studied myxobiota.

  16. Camouflage Effects of Various Colour-Marking Morphs against Different Microhabitat Backgrounds in a Polymorphic Pygmy Grasshopper Tetrix japonica

    Science.gov (United States)

    Tsurui, Kaori; Honma, Atsushi; Nishida, Takayoshi

    2010-01-01

    Background Colour-marking polymorphism is widely distributed among cryptic species. To account for the adaptive significance of such polymorphisms, several hypotheses have been proposed to date. Although these hypotheses argue over the degree of camouflage effects of marking morphs (and the interactions between morphs and their microhabitat backgrounds), as far as we know, most empirical evidence has been provided under unnatural conditions (i.e., using artificial prey). Methodology/Principal Findings Tetrix japonica, a pygmy grasshopper, is highly polymorphic in colour-markings and occurs in both sand and grass microhabitats. Even within a microhabitat, T. japonica is highly polymorphic. Using humans as dummy predators and printed photographs in which various morphs of grasshoppers were placed against different backgrounds, we addressed three questions to test the neutral, background heterogeneity, and differential crypsis hypotheses in four marking-type morphs: 1) do the morphs differ in the degree of crypsis in each microhabitat, 2) are different morphs most cryptic in specific backgrounds of the microhabitats, and 3) does the morph frequency reflect the degree of crypsis? Conclusions/Significance The degree of camouflage differed among the four morphs; therefore, the neutral hypothesis was rejected. Furthermore, the order of camouflage advantage among morphs differed depending on the two types of backgrounds (sand and grass), although the grass background consistently provided greater camouflage effects. Thus, based on our results, we could not reject the background heterogeneity hypothesis. Under field conditions, the more cryptic morphs comprised a minority of the population. Overall, our results demonstrate that the different morphs were not equivalent in the degree of crypsis, but the degree of camouflage of the morphs was not consistent with the morph frequency. These findings suggest that trade-offs exist between the camouflage benefit of body colouration

  17. Communities of Putative Ericoid Mycorrhizal Fungi Isolated from Alpine Dwarf Shrubs in Japan: Effects of Host Identity and Microhabitat.

    Science.gov (United States)

    Koizumi, Takahiko; Nara, Kazuhide

    2017-06-24

    Dwarf shrubs of the family Ericaceae are common in arctic and alpine regions. Many of these plants are associated with ericoid mycorrhizal (ERM) fungi, which allow them to take nutrients and water from the soil under harsh environmental conditions and, thus, affect host plant survival. Despite the importance of ERM fungi to alpine plant communities, limited information is available on the effects of microhabitat and host identity on ERM fungal communities. We investigated the communities of putative ERM fungi isolated from five dwarf shrub species (Arcterica nana, Diapensia lapponica, Empetrum nigrum, Loiseleuria procumbens, and Vaccinium vitis-idaea) that co-occur in an alpine region of Japan, with reference to distinct microhabitats provided by large stone pine (Pinus pumila) shrubs (i.e. bare ground, the edge of stone pine shrubs, and the inside of stone pine shrubs). We obtained 703 fungal isolates from 222 individual plants. These isolates were classified into 55 operational taxonomic units (OTUs) based on the sequencing of internal transcribed spacer regions in ribosomal DNA. These putative ERM fungal communities were dominated by Helotiales fungi for all host species. Cistella and Trimmatostroma species, which have rarely been detected in ERM roots in previous studies, were abundant. ERM fungal communities were significantly different among microhabitats (R 2 =0.28), while the host effect explained less variance in the fungal communities after excluding the microhabitat effect (R 2 =0.17). Our results suggest that the host effect on ERM fungal communities is minor and the distributions of hosts and fungal communities may be assessed based on microhabitat conditions.

  18. Camouflage effects of various colour-marking morphs against different microhabitat backgrounds in a polymorphic pygmy grasshopper Tetrix japonica.

    Science.gov (United States)

    Tsurui, Kaori; Honma, Atsushi; Nishida, Takayoshi

    2010-07-06

    Colour-marking polymorphism is widely distributed among cryptic species. To account for the adaptive significance of such polymorphisms, several hypotheses have been proposed to date. Although these hypotheses argue over the degree of camouflage effects of marking morphs (and the interactions between morphs and their microhabitat backgrounds), as far as we know, most empirical evidence has been provided under unnatural conditions (i.e., using artificial prey). Tetrix japonica, a pygmy grasshopper, is highly polymorphic in colour-markings and occurs in both sand and grass microhabitats. Even within a microhabitat, T. japonica is highly polymorphic. Using humans as dummy predators and printed photographs in which various morphs of grasshoppers were placed against different backgrounds, we addressed three questions to test the neutral, background heterogeneity, and differential crypsis hypotheses in four marking-type morphs: 1) do the morphs differ in the degree of crypsis in each microhabitat, 2) are different morphs most cryptic in specific backgrounds of the microhabitats, and 3) does the morph frequency reflect the degree of crypsis? The degree of camouflage differed among the four morphs; therefore, the neutral hypothesis was rejected. Furthermore, the order of camouflage advantage among morphs differed depending on the two types of backgrounds (sand and grass), although the grass background consistently provided greater camouflage effects. Thus, based on our results, we could not reject the background heterogeneity hypothesis. Under field conditions, the more cryptic morphs comprised a minority of the population. Overall, our results demonstrate that the different morphs were not equivalent in the degree of crypsis, but the degree of camouflage of the morphs was not consistent with the morph frequency. These findings suggest that trade-offs exist between the camouflage benefit of body colouration and other fitness components, providing a better understanding of

  19. Camouflage effects of various colour-marking morphs against different microhabitat backgrounds in a polymorphic pygmy grasshopper Tetrix japonica.

    Directory of Open Access Journals (Sweden)

    Kaori Tsurui

    2010-07-01

    Full Text Available Colour-marking polymorphism is widely distributed among cryptic species. To account for the adaptive significance of such polymorphisms, several hypotheses have been proposed to date. Although these hypotheses argue over the degree of camouflage effects of marking morphs (and the interactions between morphs and their microhabitat backgrounds, as far as we know, most empirical evidence has been provided under unnatural conditions (i.e., using artificial prey.Tetrix japonica, a pygmy grasshopper, is highly polymorphic in colour-markings and occurs in both sand and grass microhabitats. Even within a microhabitat, T. japonica is highly polymorphic. Using humans as dummy predators and printed photographs in which various morphs of grasshoppers were placed against different backgrounds, we addressed three questions to test the neutral, background heterogeneity, and differential crypsis hypotheses in four marking-type morphs: 1 do the morphs differ in the degree of crypsis in each microhabitat, 2 are different morphs most cryptic in specific backgrounds of the microhabitats, and 3 does the morph frequency reflect the degree of crypsis?The degree of camouflage differed among the four morphs; therefore, the neutral hypothesis was rejected. Furthermore, the order of camouflage advantage among morphs differed depending on the two types of backgrounds (sand and grass, although the grass background consistently provided greater camouflage effects. Thus, based on our results, we could not reject the background heterogeneity hypothesis. Under field conditions, the more cryptic morphs comprised a minority of the population. Overall, our results demonstrate that the different morphs were not equivalent in the degree of crypsis, but the degree of camouflage of the morphs was not consistent with the morph frequency. These findings suggest that trade-offs exist between the camouflage benefit of body colouration and other fitness components, providing a better

  20. Color perception influences microhabitat selection of refugia and affects monitoring success for a cryptic anuran species.

    Science.gov (United States)

    Cohen, Bradley S; MacKenzie, Michelle L; Maerz, John C; Farrell, Christopher B; Castleberry, Steven B

    2016-10-01

    Perceptual-biases are important for understanding an animal's natural history, identifying potential ecological traps, and for developing effective means to monitor individuals and populations. Despite research demonstrating anurans having a positive phototactic response towards blue colors, we do not yet understand if color cues are used functionally beyond sexual selection. The aim of our study was to determine if color cues are used in selecting microhabitat, and if anuran's blue-positive phototactic response could increase selection of artificial PVC refugia used to monitor cryptic camouflaging anuran species. We captured 32 Cope's Gray Treefrogs and placed them in mesh enclosures with three PVC tubes painted blue, brown, and white. Concurrently, we placed blue, brown, or unpainted white PVC tubes in stratified arrays around a treefrog breeding pond, and counted the number of occasions treefrogs occupied different colored PVC tubes. In the confined choice experiment, treefrogs selected blue tubes (48.3%) significantly more often than brown (28.5%) or white (23.2%) tubes. Our field experiment mirrored these findings (52.0% of capture events in blue, 29.0% in brown, and 19.0% in unpainted white tubes). Our results suggest color influences Cope's Gray Treefrog microhabitat selection, and they utilize color vision when choosing refugia. We demonstrate simple, small changes based on perceptual-biases can induce behaviors that may in turn have large impacts on sampling techniques used in monitoring and inventorying. Incorporating non-traditional physiological measures into animal inventorying and monitoring programs can be used in the future to improve conservation efforts. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Diaspore bank of bryophytes in tropical rain forests: the importance of breeding system, phylum and microhabitat.

    Science.gov (United States)

    Maciel-Silva, Adaíses S; Válio, Ivany Ferraz Marques; Rydin, Håkan

    2012-02-01

    Diaspore banks are crucial for the maintenance and resilience of plant communities, but diaspore banks of bryophytes remain poorly known, especially from tropical ecosystems. This is the first study to focus on the role of diaspore banks of bryophytes in tropical rain forests. Our aim was to test whether microhabitat (substrate type) and species traits (breeding system, phylum) are important in explaining the diaspore bank composition. Using samples cultivated in the laboratory, we assessed the number of species and shoots emerging from bark, decaying wood and soil from two sites of the Atlantic rain forest (montane and sea level) in Brazil by comparing the contribution of species by phylum (mosses, liverworts) and breeding system (monoicous, dioicous). More species emerged from bark (68) and decaying wood (55) than from soil (22). Similar numbers of species were found at both sites. Mosses were more numerous in terms of number of species and shoots, and monoicous species dominated over dioicous species. Substrate pH had only weak effects on shoot emergence. Species commonly producing sporophytes and gemmae had a high contribution to the diaspore banks. These superficial diaspore banks represented the extant vegetation rather well, but held more monoicous species (probably short-lived species) compared to dioicous ones. We propose that diaspore bank dynamics are driven by species traits and microhabitat characteristics, and that short-term diaspore banks of bryophytes in tropical rain forests contribute to fast (re)establishment of species after disturbances and during succession, particularly dioicous mosses investing in asexual reproduction and monoicous mosses investing in sexual reproduction.

  2. E. coli inactivation by visible light irradiation using a Fe–Cd/TiO2 photocatalyst: Statistical analysis and optimization of operating parameters

    NARCIS (Netherlands)

    Feilizadeh, Mehrzad; Mul, Guido; Vossoughi, M.

    2015-01-01

    In this study, the antibacterial effect of a Fe and Cd co-doped TiO2 (Fe–Cd/TiO2) visible light sensitive photocatalyst was optimized by varying operating parameters and using a response surface methodology to evaluate the experimental data. Twenty sets of disinfection experiments were conducted by

  3. Aluminum nitride coatings using response surface methodology to optimize the thermal dissipated performance of light-emitting diode modules

    Science.gov (United States)

    Jean, Ming-Der; Lei, Peng-Da; Kong, Ling-Hua; Liu, Cheng-Wu

    2018-05-01

    This study optimizes the thermal dissipation ability of aluminum nitride (AlN) ceramics to increase the thermal performance of light-emitting diode (LED) modulus. AlN powders are deposited on heat sink as a heat interface material, using an electrostatic spraying process. The junction temperature of the heat sink is developed by response surface methodology based on Taguchi methods. In addition, the structure and properties of the AlN coating are examined using X-ray photoelectron spectroscopy (XPS). In the XPS analysis, the AlN sub-peaks are observed at 72.79 eV for Al2p and 398.88 eV for N1s, and an N1s sub-peak is assigned to N-O at 398.60eV and Al-N bonding at 395.95eV, which allows good thermal properties. The results have shown that the use of AlN ceramic material on a heat sink can enhance the thermal performance of LED modules. In addition, the percentage error between the predicted and experimental results compared the quadric model with between the linear and he interaction models was found to be within 7.89%, indicating that it was a good predictor. Accordingly, RSM can effectively enhance the thermal performance of an LED, and the beneficial heat dissipation effects for AlN are improved by electrostatic spraying.

  4. Structural optimization for remote white light-emitting diodes with quantum dots and phosphor: packaging sequence matters.

    Science.gov (United States)

    Xie, Bin; Chen, Wei; Hao, Junjie; Wu, Dan; Yu, Xingjian; Chen, Yanhua; Hu, Run; Wang, Kai; Luo, Xiaobing

    2016-12-26

    White light-emitting diodes (WLEDs) with quantum dots (QDs) and phosphor have attracted tremendous attentions due to their excellent color rendering ability. In the packaging process, QDs layer and phosphor-silicone layer tend to be separated to reduce the reabsorption losses, and to maintain the stability of QDs surface ligands. This study investigated the packaging sequence between QDs and phosphor on the optical and thermal performances of WLEDs. The output optical power and PL spectra were measured and analyzed, and the temperature fields were simulated and validated experimentally by infrared thermal imager. It was found that when driven by 60 mA, the QDs-on-phosphor type WLEDs achieved luminous efficiency (LE) of 110 lm/W, with color rendering index (CRI) of Ra = 92 and R9 = 80, while the phosphor-on-QDs type WLEDs demonstrated lower LE of 68 lm/W, with Ra = 57 and R9 = 24. Moreover, the QDs-on-phosphor type WLEDs generated less heat than that of another, consequently the highest temperature in the QDs-on-phosphor type was lower than another, and the temperature difference can reach 12.3°C. Therefore, in terms of packaging sequence, the QDs-on-phosphor type is an optimal packaging architecture for higher optical efficiency, better color rendering ability and lower device temperature.

  5. Inkjet-Printed Small-Molecule Organic Light-Emitting Diodes: Halogen-Free Inks, Printing Optimization, and Large-Area Patterning.

    Science.gov (United States)

    Zhou, Lu; Yang, Lei; Yu, Mengjie; Jiang, Yi; Liu, Cheng-Fang; Lai, Wen-Yong; Huang, Wei

    2017-11-22

    Manufacturing small-molecule organic light-emitting diodes (OLEDs) via inkjet printing is rather attractive for realizing high-efficiency and long-life-span devices, yet it is challenging. In this paper, we present our efforts on systematical investigation and optimization of the ink properties and the printing process to enable facile inkjet printing of conjugated light-emitting small molecules. Various factors on influencing the inkjet-printed film quality during the droplet generation, the ink spreading on the substrates, and its solidification processes have been systematically investigated and optimized. Consequently, halogen-free inks have been developed and large-area patterning inkjet printing on flexible substrates with efficient blue emission has been successfully demonstrated. Moreover, OLEDs manufactured by inkjet printing the light-emitting small molecules manifested superior performance as compared with their corresponding spin-cast counterparts.

  6. Microhabitat Effects on N2O Emissions from Floodplain Soils under Controlled Conditions

    Science.gov (United States)

    Ley, Martin; Lehmann, Moritz F.; Niklaus, Pascal A.; Kuhn, Thomas; Luster, Jörg

    2016-04-01

    Semi-terrestrial soils such as floodplain soils are considered to be potential hotspots of nitrous oxide (N2O) emissions. The quantitative assessment of N2O release from these hotspots under field conditions, and of the microbial pathways that underlie net N2O production (ammonium oxidation, nitrifier-denitrification, and denitrification) is challenging because of their high spatial and temporal variability. The production and consumption of N2O appears to be linked to the presence or absence of micro-niches, providing specific conditions that may be favorable to either of the relevant microbial pathways. Flood events have been shown to trigger moments of enhanced N2O emission through a close coupling of niches with high and low oxygen availabilities. This coupling might be modulated by microhabitat effects related to soil aggregate formation, root soil interactions and the degradation of organic matter accumulations. In order to assess how these factors can modulate N2O production and consumption under simulated flooding/drying conditions, we have set up a mesocosm experiment with N-rich floodplain soils comprising different combinations of soil aggregate size classes and inert matrix material. These model soils were either planted with basket willow (Salix viminalis L.), mixed with leaf litter, or left untreated. Throughout a simulated flood event, we repeatedly measured the net N2O production rate. In addition, soil water content, redox potential, as well as C and N substrate availability were monitored. In order to gain insight into the sources of, and biogeochemical controls on N2O production, we also measured the bulk δ15N signature of the produced N2O, as well as its intramolecular 15N site preference (SP). In this presentation we focus on a period of enhanced N2O emission during the drying phase after 48 hrs of flooding. We will discuss the observed emission patterns in the context of possible treatment effects. Soils with large aggregates showed a

  7. Systematic analysis of protein–detergent complexes applying dynamic light scattering to optimize solutions for crystallization trials

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Arne [University of Hamburg, c/o DESY, Building 22a, Notkestrasse 85, 22603 Hamburg (Germany); Dierks, Karsten [University of Hamburg, c/o DESY, Building 22a, Notkestrasse 85, 22603 Hamburg (Germany); XtalConcepts, Marlowring 19, 22525 Hamburg (Germany); Hussein, Rana [University of Hamburg, c/o DESY, Building 22a, Notkestrasse 85, 22603 Hamburg (Germany); Brillet, Karl [ESBS, Pôle API, 300 Boulevard Sébastien Brant, CS10413, 67412 Illkirch CEDEX (France); Brognaro, Hevila [São Paulo State University, UNESP/IBILCE, Caixa Postal 136, São José do Rio Preto-SP, 15054 (Brazil); Betzel, Christian, E-mail: christian.betzel@uni-hamburg.de [University of Hamburg, c/o DESY, Building 22a, Notkestrasse 85, 22603 Hamburg (Germany)

    2015-01-01

    Application of in situ dynamic light scattering to solutions of protein–detergent complexes permits characterization of these complexes in samples as small as 2 µl in volume. Detergents are widely used for the isolation and solubilization of membrane proteins to support crystallization and structure determination. Detergents are amphiphilic molecules that form micelles once the characteristic critical micelle concentration (CMC) is achieved and can solubilize membrane proteins by the formation of micelles around them. The results are presented of a study of micelle formation observed by in situ dynamic light-scattering (DLS) analyses performed on selected detergent solutions using a newly designed advanced hardware device. DLS was initially applied in situ to detergent samples with a total volume of approximately 2 µl. When measured with DLS, pure detergents show a monodisperse radial distribution in water at concentrations exceeding the CMC. A series of all-transn-alkyl-β-d-maltopyranosides, from n-hexyl to n-tetradecyl, were used in the investigations. The results obtained verify that the application of DLS in situ is capable of distinguishing differences in the hydrodynamic radii of micelles formed by detergents differing in length by only a single CH{sub 2} group in their aliphatic tails. Subsequently, DLS was applied to investigate the distribution of hydrodynamic radii of membrane proteins and selected water-insoluble proteins in presence of detergent micelles. The results confirm that stable protein–detergent complexes were prepared for (i) bacteriorhodopsin and (ii) FetA in complex with a ligand as examples of transmembrane proteins. A fusion of maltose-binding protein and the Duck hepatitis B virus X protein was added to this investigation as an example of a non-membrane-associated protein with low water solubility. The increased solubility of this protein in the presence of detergent could be monitored, as well as the progress of proteolytic

  8. Evolution of microhabitat association and morphology in a diverse group of cryptobenthic coral reef fishes (Teleostei: Gobiidae: Eviota)

    KAUST Repository

    Tornabene, Luke; Ahmadia, Gabby N.; Berumen, Michael L.; Smith, David J.; Jompa, Jamaluddì n; Pezold, Frank L.

    2013-01-01

    Gobies (Teleostei: Gobiidae) are an extremely diverse and widely distributed group and are the second most species rich family of vertebrates. Ecological drivers are key to the evolutionary success of the Gobiidae. However, ecological and phylogenetic data are lacking for many diverse genera of gobies. Our study investigated the evolution of microhabitat association across the phylogeny of 18 species of dwarfgobies (genus Eviota), an abundant and diverse group of coral reef fishes. In addition, we also explore the evolution of pectoral fin-ray branching and sensory head pores to determine the relationship between morphological evolution and microhabitat shifts. Our results demonstrate that Eviota species switched multiple times from a facultative hard-coral association to inhabiting rubble or mixed sand/rubble habitat. We found no obvious relationship between microhabitat shifts and changes in pectoral fin-ray branching or reduction in sensory pores, with the latter character being highly homoplasious throughout the genus. The relative flexibility in coral-association in Eviota combined with the ability to move into non-coral habitats suggests a genetic capacity for ecological release in contrast to the strict obligate coral-dwelling relationship commonly observed in closely related coral gobies, thus promoting co-existence through fine scale niche partitioning. The variation in microhabitat association may facilitate opportunistic ecological speciation, and species persistence in the face of environmental change. This increased speciation opportunity, in concert with a high resilience to extinction, may explain the exceptionally high diversity seen in Eviota compared to related genera in the family. © 2012 Elsevier Inc.

  9. Trophic ecology and microhabitat utilization by the Bufo gargarizans, Rana guentheri, and Rana limnocharis in southwestern China

    Directory of Open Access Journals (Sweden)

    Tonglei Yu

    2012-02-01

    Full Text Available We studied the trophic ecology and microhabitat use of the Asiatic toad, Bufo gargarizans Cantor, 1842; Guentheri frog, Rana guentheri (Boulenger, 1882; and the Ricefield frog, Rana limnocharis (Boie, 1834. These three species are common around Nanchong City, in southwestern China, where they live in the same habitat before hibernation. The main objective of this study was to analyze the diets and patterns of coexistence relative to the microhabitat of each species. In the Asiatic toad, based on index of relative importance, the diet was dominated by adult Coleoptera, Isopoda, and Hymenoptera (29.53%, 22.07%, and 15.20%, respectively, while the Guenther's frog and Ricefield frog ingested predominantly Orthoptera (67.44% and 40.94%, respectively. The standardized feeding niche breadth of the Asiatic toad (0.277 was wider than that of the Guentheri frog (0.177 and Ricefield frog (0.269. The overlap in the trophic niche (prey proportion between the toad and two species of frog was low (toad vs. Guentheri frog, C H = 0.526; toad vs. Ricefield frog, C H = 0.521, while this was high for the two species of frogs (C H = 0.942. The three species also differed in microhabitat use. Asiatic toads showed strong preference for small roads close to shrubs or pre-harvest corn, while Guenther's frogs preferred bare surfaces on habitat edges, and Ricefield frogs showed a preference for bare surfaces as feeding sites in the middle of habitat. The difference in diet observed during three species seems to be explained by the difference in microhabitat use and body size of three species.

  10. Effects of microhabitat and large-scale land use on stream salamander occupancy in the coalfields of Central Appalachia

    Science.gov (United States)

    Sweeten, Sara E.; Ford, W. Mark

    2016-01-01

    Large-scale coal mining practices, particularly surface coal extraction and associated valley fills as well as residential wastewater discharge, are of ecological concern for aquatic systems in central Appalachia. Identifying and quantifying alterations to ecosystems along a gradient of spatial scales is a necessary first-step to aid in mitigation of negative consequences to aquatic biota. In central Appalachian headwater streams, apart from fish, salamanders are the most abundant vertebrate predator that provide a significant intermediate trophic role linking aquatic and terrestrial food webs. Stream salamander species are considered to be sensitive to aquatic stressors and environmental alterations, as past research has shown linkages among microhabitat parameters, large-scale land use such as urbanization and logging, and salamander abundances. However, there is little information examining these relationships between environmental conditions and salamander occupancy in the coalfields of central Appalachia. In the summer of 2013, 70 sites (sampled two to three times each) in the southwest Virginia coalfields were visited to collect salamanders and quantify stream and riparian microhabitat parameters. Using an information-theoretic framework, effects of microhabitat and large-scale land use on stream salamander occupancy were compared. The findings indicate that Desmognathus spp. occupancy rates are more correlated to microhabitat parameters such as canopy cover than to large-scale land uses. However, Eurycea spp. occupancy rates had a strong association with large-scale land uses, particularly recent mining and forest cover within the watershed. These findings suggest that protection of riparian habitats is an important consideration for maintaining aquatic systems in central Appalachia. If this is not possible, restoration riparian areas should follow guidelines using quick-growing tree species that are native to Appalachian riparian areas. These types of trees

  11. Phylogeny and micro-habitats utilized by lizards determine the composition of their endoparasites in the semiarid Caatinga of Northeast Brazil.

    Science.gov (United States)

    Brito, S V; Corso, G; Almeida, A M; Ferreira, F S; Almeida, W O; Anjos, L A; Mesquita, D O; Vasconcellos, A

    2014-11-01

    Trophic networks can have architectonic configurations influenced by historical and ecological factors. The objective of this study was to analyze the architecture of networks between lizards, their endoparasites, diet, and micro-habitat, aiming to understand which factors exert an influence on the composition of the species of parasites. All networks showed a compartmentalized pattern. There was a positive relation between diet and the diversity of endoparasites. Our analyses also demonstrated that phylogeny and the use of micro-habitat influenced the composition of species of endoparasites and diet pattern of lizards. The principal factor that explained the modularity of the network was the foraging strategy, with segregation between the "active foragers" and "sit-and-wait" lizards. Our analyses also demonstrated that historical (phylogeny) and ecological factors (use of micro-habitat by the lizards) influenced the composition of parasite communities. These results corroborate other studies with ectoparasites, which indicate phylogeny and micro-habitat as determinants in the composition of parasitic fauna. The influence of phylogeny can be the result of coevolution between parasites and lizards in the Caatinga, and the influence of micro-habitat should be a result of adaptations of species of parasites to occupy the same categories of micro-habitats as hosts, thus favoring contagion.

  12. Disentangling above- and below-ground facilitation drivers in arid environments: the role of soil microorganisms, soil properties and microhabitat.

    Science.gov (United States)

    Lozano, Yudi M; Armas, Cristina; Hortal, Sara; Casanoves, Fernando; Pugnaire, Francisco I

    2017-12-01

    Nurse plants promote establishment of other plant species by buffering climate extremes and improving soil properties. Soil biota plays an important role, but an analysis to disentangle the effects of soil microorganisms, soil properties and microclimate on facilitation is lacking. In three microhabitats (gaps, small and large Retama shrubs), we placed six microcosms with sterilized soil, two per soil origin (i.e. from each microhabitat). One in every pair received an alive, and the other a sterile, inoculum from its own soil. Seeds of annual plants were sown into the microcosms. Germination, survival and biomass were monitored. Soil bacterial communities were characterized by pyrosequencing. Germination in living Retama inoculum was nearly double that of germination in sterile inoculum. Germination was greater under Retama canopies than in gaps. Biomass was up to three times higher in nurse than in gap soils. Soil microorganisms, soil properties and microclimate showed a range of positive to negative effects on understory plants depending on species identity and life stage. Nurse soil microorganisms promoted germination, but the effect was smaller than the positive effects of soil properties and microclimate under nurses. Nurse below-ground environment (soil properties and microorganisms) promoted plant growth and survival more than nurse microhabitat. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  13. Microhabitat use by Cnemidophorus vacariensis (Squamata: Teiidae in the grasslands of the Araucaria Plateau, Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Rodrigo Caruccio

    2010-01-01

    Full Text Available Microhabitat use by Cnemidophorus vacariensis Feltrim & Lema, 2000 as studied between October 2006 and September 2007 in two rocky formations in the municipality of Bom Jesus. The area was searched randomly between 8:00 am and 6:00 pm and the microhabitat used by the lizards was recorded. Our observations revealed that C. vacariensis has terrestrial habits and prefers open areas. Burrows are the main microhabitat used by the species (56.38%. When in activity, 54.76% of the individuals were observed under rocks, and 38.1% on the ground where herbaceous vegetation was present. The rocks under which they constructed their burrows were on average significantly thicker during warmer seasons temperatures (x¯ = 13,45cm with respect to colder seasons (x¯ = 9,85cm. The rocks selected by the adults (x¯ = 12.94 cm were on average significantly thicker than those selected by the juveniles (x¯ = 9.86cm. There were no statistically significant differences between sexes with respect to rock thickness.

  14. POPULATION AND MICROHABITAT OF Gonystylus bancanus (Miq. Kurz IN DANAU PULAU BESAR-DANAU BAWAH WILDLIFE SANCTUARY, SUMATRA

    Directory of Open Access Journals (Sweden)

    Yayan Wahyu C. Kusuma

    2013-01-01

    Full Text Available Ramin (Gonystylus bancanus is one of the major timber species that facing high exploitation in Indonesia. This species can only be found on a specific peat swamp habitat, thus it confines its distribution. Information on its current population and microhabitat characteristics is relatively limited. Here, we investigated natural population and microhabitat of ramin in a peat swamp area in Riau Province using  random transects consist of 46 (100m2 sampling plots. Forty-eight individuals of ramin were found in which 46 of these belonged to G. bancanus, while the other two were different species. The estimated population density of ramin in this area was 7.18±2.75 individuals/ha i.e there were approximately seven individuals in each one-ha area of study. The population structure of ramin showed a J-shaped curve bearing many large old trees with few saplings without any seedlings. The microhabitat was investigated using the Discriminant Function Analysis (DFA and Canonical Analysis, generating two significant variables that discriminated three groups of the population.

  15. Banana leaf and glucose mineralization and soil organic matter in microhabitats of banana plantations under long-term pesticide use.

    Science.gov (United States)

    Blume, Elena; Reichert, José Miguel

    2015-06-01

    Soil organic matter (SOM) and microbial activity are key components of soil quality and sustainability. In the humid tropics of Costa Rica 3 pesticide regimes were studied-fungicide (low input); fungicide and herbicide (medium input); and fungicide, herbicide, and nematicide (high input)-under continuous banana cultivation for 5 yr (young) or 20 yr (old) in 3 microhabitats-nematicide ring around plants, litter pile of harvested banana, and bare area between litter pile and nematicide ring. Soil samples were incubated sequentially in the laboratory: unamended, amended with glucose, and amended with ground banana leaves. Soil organic matter varied with microhabitat, being greatest in the litter pile, where microbes had the greatest basal respiration with ground banana leaf, whereas microbes in the nematicide ring had the greatest respiration with glucose. These results suggest that soil microbes adapt to specific microhabitats. Young banana plantations had similar SOM compared with old plantations, but the former had greater basal microbial respiration in unamended and in glucose-amended soil and greater first-order mineralization rates in glucose-amended soil, thus indicating soil biological quality decline over time. High pesticide input did not decrease microbial activity or mineralization rate in surface soil. In conclusion, microbial activity in tropical volcanic soil is highly adaptable to organic and inorganic inputs. © 2015 SETAC.

  16. Nematode consumption by mite communities varies in different forest microhabitats as indicated by molecular gut content analysis.

    Science.gov (United States)

    Heidemann, Kerstin; Ruess, Liliane; Scheu, Stefan; Maraun, Mark

    2014-01-01

    Soil animals live in complex and heterogeneous habitats including litter of various types but also microhabitats such as mosses, fungal mats and grass patches. Soil food webs have been separated into a slow fungal and a fast bacterial energy channel. Bacterial-feeding nematodes are an important component of the bacterial energy channel by consuming bacteria and forming prey for higher trophic levels such as soil microarthropods. Investigating the role of nematodes as prey for higher trophic level consumers has been hampered by methodological problems related to their small body size and lack in skeletal structures which can be traced in the gut of consumers. Recent studies using molecular gut content analyses suggest that nematodes form major prey of soil microarthropods including those previously assumed to live as detritivores. Using molecular markers we traced nematode prey in fourteen abundant soil microarthropod taxa of Mesostigmata and Oribatida (both Acari) from three different microhabitats (litter, grass and moss). Consumption of nematodes varied between mite species indicating that trophic niche variation contributes to the high diversity of microarthropods in deciduous forests. Further, consumption of nematodes by Mesostigmata (but not Oribatida) differed between microhabitats indicating that trophic niches vary with habitat characteristics. Overall, the results suggest that free-living bacterial-feeding nematodes form important prey for soil microarthropods including those previously assumed to live as detritivores.

  17. Metal-free virucidal effects induced by g-C3N4 under visible light irradiation: Statistical analysis and parameter optimization.

    Science.gov (United States)

    Zhang, Chi; Li, Yi; Zhang, Wenlong; Wang, Peifang; Wang, Chao

    2018-03-01

    Waterborne viruses with a low infectious dose and a high pathogenic potential pose a serious risk for humans all over the world, calling for a cost-effective and environmentally-friendly inactivation method. Optimizing operational parameters during the disinfection process is a facile and efficient way to achieve the satisfactory viral inactivation efficiency. Here, the antiviral effects of a metal-free visible-light-driven graphitic carbon nitride (g-C 3 N 4 ) photocatalyst were optimized by varying operating parameters with response surface methodology (RSM). Twenty sets of viral inactivation experiments were performed by changing three operating parameters, namely light intensity, photocatalyst loading and reaction temperature, at five levels. According to the experimental data, a semi-empirical model was developed with a high accuracy (determination coefficient R 2  = 0.9908) and then applied to predict the final inactivation efficiency of MS2 (a model virus) after 180 min exposure to the photocatalyst and visible light illumination. The corresponding optimal values were found to be 199.80 mW/cm 2 , 135.40 mg/L and 24.05 °C for light intensity, photocatalyst loading and reaction temperature, respectively. Under the optimized conditions, 8 log PFU/mL of viruses could be completely inactivated by g-C 3 N 4 without regrowth within 240 min visible light irradiation. Our study provides not only an extended application of RSM in photocatalytic viral inactivation but also a green and effective method for water disinfection. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Effects of dam operation on the endangered Júcar nase, Parachondrostoma arrigonis, related to mesohabitats, microhabitat availability and water temperature regime, in the river Cabriel (Spain)

    Science.gov (United States)

    Martinez-Capel, Francisco; Costa, Rui; Muñoz-Mas, Rafael; Diego Alcaraz-Hernandez, Juan; Hernandez-Mascarell, Aina

    2010-05-01

    The presence of large dams affects habitat availability, often regarded as the primary factor that limits population and community recovery in rivers. Physical habitat is often targeted in restoration, but there is often a paucity of useful information. Habitat degradation has reduced the complexity and connectivity of the Mediterranean streams in Spain. These changes have diminished the historical range of the endangered Júcar nase, Parachondrostoma arrigonis (Steindachner, 1866), isolated the populations of this species, and probably contributed to its risk of extinction. In the Júcar River basin (Spain), where this fish is endemic, the populations are mainly restricted to the river Cabriel, which is fragmented in two segments by the large dam of Contreras. In this river, 3 main lines of research were developed from 2006 to 2008, i.e., microhabitat suitability, mesohabitat suitability, and water temperature, in order to relate such kind of variables with the flow regime. The main goal of the research project, funded by the Spanish Ministry of Environment, was to detect the main reasons of the species decline, and to propose dam operation improvements to contribute to the recovery of the species. The flow and water temperature regimes were also studied in the river Cabriel, upstream and downstream the large dam of Contreras. During the three years of study, below the dam it was observed a small and not significant variation in the proportions of slow and fast habitats; the regulated flow regime was pointed out as the main reason of such variations. At the microhabitat scale, optimal ranges for average depth and velocity were defined; these data allowed us to develop an estimation of weighted useable area under natural and regulated conditions. The Júcar nase were found majorly at depths no greater than 1,15 meters with slow water velocities. It was possible to observe a clear alteration of the flow and water temperature regime below the dam, due to the cold

  19. Microhabitat selection by three common bird species of montane farmlands in Northern Greece.

    Science.gov (United States)

    Tsiakiris, Rigas; Stara, Kalliopi; Pantis, John; Sgardelis, Stefanos

    2009-11-01

    Common farmland birds are declining throughout Europe; however, marginal farmlands that escaped intensification or land abandonment remain a haven for farmland species in some Mediterranean mountains. The purpose of this study is to identify the most important anthropogenic microhabitat characteristics for Red-Backed Shrike (Lanius collurio), Corn Bunting (Miliaria calandra) and Common Whitethroat (Sylvia communis) in three such areas within the newly established Northern Pindos National Park. We compare land use structural and physiognomic characteristics of the habitat within 133 plots containing birds paired with randomly selected "non-bird" plots. Using logistic regression and classification-tree models we identify the specific habitat requirements for each of the three birds. The three species show a preference for agricultural mosaics dominated by rangelands with scattered shrub or short trees mixed with arable land. Areas with dikes and dirt roads are preferred by all three species, while the presence of fences and periodically burned bushes and hedges are of particular importance for Red-Backed Shrike. Across the gradient of vegetation density and height, M. calandra is mostly found in grasslands with few dwarf shrubs and short trees, S. communis in places with more dense and tall vegetation of shrub, trees and hedges, and L. collurio, being a typical bird of ecotones, occurs in both habitats and in intermediate situations. In all cases those requirements are associated with habitat features maintained either directly or indirectly by the traditional agricultural activities in the area and particularly by the long established extensive controlled grazing that prevent shrub expansion.

  20. Obtaining Low Rank Coal Biotransforming Bacteria from Microhabitats Enriched with Carbonaceous Residues

    International Nuclear Information System (INIS)

    Valero Valero, Nelson; Rodriguez Salazar, Luz Nidia; Mancilla Gomez, Sandra; Contreras Bayona, Leydis

    2012-01-01

    Bacteria capable of low rank coal (LRC) biotransform were isolated from environmental samples altered with coal in the mine The Cerrejon. A protocol was designed to select strains more capable of LRC biotransform, the protocol includes isolation in a selective medium with LRC powder, qualitative and quantitative tests for LRC solubilization in solid and liquid culture medium. Of 75 bacterial strains isolated, 32 showed growth in minimal salts agar with 5 % carbon. The strains that produce higher values of humic substances (HS) have a mechanism of solubilization associated with pH changes in the culture medium, probably related to the production of extracellular alkaline substances by bacteria. The largest number of strains and bacteria with more solubilizing activity on LRC were isolated from sludge with high content of carbon residue and rhizosphere of Typha domingensis and Cenchrus ciliaris grown on sediments mixed with carbon particles, this result suggests that obtaining and solubilization capacity of LRC by bacteria may be related to the microhabitat where the populations originated.

  1. Gradients of microhabitat and crappie (Pomoxis spp.) distributions in reservoir coves

    Science.gov (United States)

    Kaczka, Levi J.; Miranda, Leandro E.

    2013-01-01

    Embayments are among the most widespread littoral habitats found in Mississippi flood-control reservoirs. These macrohabitats represent commonly used nursery zones for age-0 crappies, Pomoxis spp., despite barren and eroded shorelines formed over 60–70 years of annual water level fluctuations. We tested if embayments displayed microhabitat gradients linked to the effect of water level fluctuations on riparian vegetation and if these gradients were paralleled by gradients in age-0 crappie distribution. Habitat composition changed longitudinally along the embayments with the most pronounced gradient representing a shift from nonvegetated mudflats near the mouth of embayments to herbaceous material upstream. The degree of habitat change depended on the water level. Similarly, catch rates of crappies increased upstream toward the rear of embayments, differing among water levels and reservoirs, but the longitudinal pattern persisted. Our results indicate that habitat composition gradients occur in embayments of northwest Mississippi flood-control reservoirs and that these gradients may influence a similar gradient in age-0 crappie distribution. While the biotic interactions behind the gradients may be less clear, we speculate that water level is the main factor influencing the observed gradients in habitat composition and fish. Management to benefit age-0 crappies may involve habitat improvement along embayment shorelines and water level regimes that foster growth of herbaceous plants.

  2. Co-Optimization of Fuels & Engines (Co-Optima) Initiative: Recent Progress on Light-Duty Boosted Spark-Ignition Fuels/Engines

    Energy Technology Data Exchange (ETDEWEB)

    Farrell, John

    2017-07-03

    This presentation reports recent progress on light-duty boosted spark-ignition fuels/engines being developed under the Co-Optimization of Fuels and Engines initiative (Co-Optima). Co-Optima is focused on identifying fuel properties that optimize engine performance, independent of composition, allowing the market to define the best means to blend and provide these fuels. However, in support of this, we are pursuing a systematic study of blendstocks to identify a broad range of feasible options, with the objective of identifying blendstocks that can provide target ranges of key fuel properties, identifying trade-offs on consistent and comprehensive basis, and sharing information with stakeholders.

  3. Enhanced biofuel production potential with nutritional stress amelioration through optimization of carbon source and light intensity in Scenedesmus sp. CCNM 1077.

    Science.gov (United States)

    Pancha, Imran; Chokshi, Kaumeel; Mishra, Sandhya

    2015-03-01

    Microalgal mixotrophic cultivation is one of the most potential ways to enhance biomass and biofuel production. In the present study, first of all ability of microalgae Scenedesmus sp. CCNM 1077 to utilize various carbon sources under mixotrophic growth condition was evaluated followed by optimization of glucose concentration and light intensity to obtain higher biomass, lipid and carbohydrate contents. Under optimized condition i.e. 4 g/L glucose and 150 μmol m(-2) s(-1) light intensity, Scenedesmus sp. CCNM 1077 produced 1.2g/L dry cell weight containing 23.62% total lipid and 42.68% carbohydrate. Addition of glucose shown nutritional stress ameliorating effects and around 70% carbohydrate and 25% total lipid content was found with only 21% reduction in dry cell weight under nitrogen starved condition. This study shows potential application of mixotrophically grown Scenedesmus sp. CCNM 1077 for bioethanol and biodiesel production feed stock. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Light-optimized growth of cyanobacterial cultures: Growth phases and productivity of biomass and secreted molecules in light-limited batch growth.

    Science.gov (United States)

    Clark, Ryan L; McGinley, Laura L; Purdy, Hugh M; Korosh, Travis C; Reed, Jennifer L; Root, Thatcher W; Pfleger, Brian F

    2018-03-27

    Cyanobacteria are photosynthetic microorganisms whose metabolism can be modified through genetic engineering for production of a wide variety of molecules directly from CO 2 , light, and nutrients. Diverse molecules have been produced in small quantities by engineered cyanobacteria to demonstrate the feasibility of photosynthetic biorefineries. Consequently, there is interest in engineering these microorganisms to increase titer and productivity to meet industrial metrics. Unfortunately, differing experimental conditions and cultivation techniques confound comparisons of strains and metabolic engineering strategies. In this work, we discuss the factors governing photoautotrophic growth and demonstrate nutritionally replete conditions in which a model cyanobacterium can be grown to stationary phase with light as the sole limiting substrate. We introduce a mathematical framework for understanding the dynamics of growth and product secretion in light-limited cyanobacterial cultures. Using this framework, we demonstrate how cyanobacterial growth in differing experimental systems can be easily scaled by the volumetric photon delivery rate using the model organisms Synechococcus sp. strain PCC7002 and Synechococcus elongatus strain UTEX2973. We use this framework to predict scaled up growth and product secretion in 1L photobioreactors of two strains of Synechococcus PCC7002 engineered for production of l-lactate or L-lysine. The analytical framework developed in this work serves as a guide for future metabolic engineering studies of cyanobacteria to allow better comparison of experiments performed in different experimental systems and to further investigate the dynamics of growth and product secretion. Copyright © 2018 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  5. Comparative microhabitat characteristics at oviposition sites of the California red-legged frog (Rana draytonii)

    Science.gov (United States)

    Alvarez, Jeff A.; Cook, David G.; Yee, Julie L.; van Hattem, Michael G.; Fong, Darren R.; Fisher, Robert N.

    2013-01-01

    We studied the microhabitat characteristics of 747 egg masses of the federally-threatened Rana draytonii (California red-legged frog) at eight sites in California. our study showed that a broad range of aquatic habitats are utilized by ovipositing R. draytonii, including sites with perennial and ephemeral water sources, natural and constructed wetlands, lentic and lotic hydrology, and sites surrounded by protected lands and nested within modified urban areas. We recorded 45 different egg mass attachment types, although the use of only a few types was common at each site. These attachment types ranged from branches and roots of riparian trees, emergent and submergent wetland vegetation, flooded upland grassland/ruderal vegetation, and debris. eggs were deposited in relatively shallow water (mean 39.7 cm) when compared to maximum site depths. We found that most frogs in artificial pond, natural creek, and artificial channel habitats deposited egg masses within one meter of the shore, while egg masses in a seasonal marsh averaged 27.3 m from the shore due to extensive emergent vegetation. Rana draytonii appeared to delay breeding in lotic habitats and in more inland sites compared to lentic habitats and coastal sites. eggs occurred as early as mid-december at a coastal artificial pond and as late as mid-April in an inland natural creek. We speculate that this delay in breeding may represent a method of avoiding high-flow events and/or freezing temperatures. Understanding the factors related to the reproductive needs of this species can contribute to creating, managing, or preserving appropriate habitat, and promoting species recovery.

  6. There’s more than one way to climb a tree: Limb length and microhabitat use in lizards with toe pads

    Science.gov (United States)

    Harte, Scott; Vickers, Mathew; Harmon, Luke J.; Schwarzkopf, Lin

    2017-01-01

    Ecomorphology links microhabitat and morphology. By comparing ecomorphological associations across clades, we can investigate the extent to which evolution can produce similar solutions in response to similar challenges. While Anolis lizards represent a well-studied example of repeated convergent evolution, very few studies have investigated the ecomorphology of geckos. Similar to anoles, gekkonid lizards have independently evolved adhesive toe pads and many species are scansorial. We quantified gecko and anole limb length and microhabitat use, finding that geckos tend to have shorter limbs than anoles. Combining these measurements with microhabitat observations of geckos in Queensland, Australia, we observed geckos using similar microhabitats as reported for anoles, but geckos with relatively longer limbs were using narrower perches, differing from patterns observed in anoles and other lizards. We also observed arboreal geckos with relatively shorter proximal limb segments as compared to rock-dwelling and terrestrial geckos, similar to patterns observed for other lizards. We conclude that although both geckos and anoles have adhesive pads and use similar microhabitats, their locomotor systems likely complement their adhesive pads in unique ways and result in different ecomorphological patterns, reinforcing the idea that species with convergent morphologies still have idiosyncratic characteristics due to their own separate evolutionary histories. PMID:28953920

  7. Color optimization of conjugated-polymer/InGaN hybrid white light emitting diodes by incomplete energy transfer

    International Nuclear Information System (INIS)

    Chang, Chi-Jung; Lai, Chun-Feng; Madhusudhana Reddy, P.; Chen, Yung-Lin; Chiou, Wei-Yung; Chang, Shinn-Jen

    2015-01-01

    By using the wavelength conversion method, white light emitting diodes (WLEDs) were produced by applying mixtures of polysiloxane and fluorescent polymers on InGaN based light emitting diodes. UV curable organic–inorganic hybrid materials with high refractive index (1.561), compromised optical, thermal and mechanical properties was used as encapsulants. Red light emitting fluorescent FABD polymer (with 9,9-dioctylfluorene (F), anthracene (A) and 2,1,3-benzothiadiazole (B), and 4,7-bis(2-thienyl)-2,1,3-benzothiadiazole (D) repeating units) and green light emitting fluorescent FAB polymer were used as wavelength converters. The encapsulant/fluorescent polymer mixture and InGaN produce the white light by incomplete energy transfer mechanism. WLEDs with high color rendering index (CRI, about 93), and tunable correlated color temperature (CCT) properties can be produced by controlling the composition and chemical structures of encapsulating polymer and fluorescent polymer in hybrid materials, offering cool-white and neutral-white LEDs. - Highlights: • Highly efficient white light-emitting diodes (WLEDs) were produced. • Conjugated-polymer/InGaN hybrid WLEDs by incomplete energy transfer mechanism. • WLEDs with high color-rendering index and tunable correlated color temperature. • Polysiloxane encapsulant with superior optical, mechanical and thermal properties

  8. CO2 Removal from Biogas by Cyanobacterium Leptolyngbya sp. CChF1 Isolated from the Lake Chapala, Mexico: Optimization of the Temperature and Light Intensity.

    Science.gov (United States)

    Choix, Francisco J; Snell-Castro, Raúl; Arreola-Vargas, Jorge; Carbajal-López, Alberto; Méndez-Acosta, Hugo O

    2017-12-01

    In the present study, the capacity of the cyanobacterium Leptolyngbya sp. CChF1 to remove CO 2 from real and synthetic biogas was evaluated. The identification of the cyanobacterium, isolated from the lake Chapala, was carried out by means of morphological and molecular analyses, while its potential for CO 2 removal from biogas streams was evaluated by kinetic experiments and optimized by a central composite design coupled to a response surface methodology. Results demonstrated that Leptolyngbya sp. CChF1 is able to remove CO 2 and grow indistinctly in real or synthetic biogas streams, showing tolerance to high concentrations of CO 2 and CH 4 , 25 and 75%, respectively. The characterization of the biomass composition at the end of the kinetic assays revealed that the main accumulated by-products under both biogas streams were lipids, followed by proteins and carbohydrates. Regarding the optimization experiments, light intensity and temperature were the studied variables, while synthetic biogas was the carbon source. Results showed that light intensity was significant for CO 2 capture efficiency (p = 0.0290), while temperature was significant for biomass production (p = 0.0024). The predicted CO 2 capture efficiency under optimal conditions (27.1 °C and 920 lx) was 93.48%. Overall, the results of the present study suggest that Leptolyngbya sp. CChF1 is a suitable candidate for biogas upgrading.

  9. LIGHT Is critical for IL-12 production by dendritic cells, optimal CD4+ Th1 cell response, and resistance to Leishmania major.

    Science.gov (United States)

    Xu, Guilian; Liu, Dong; Okwor, Ifeoma; Wang, Yang; Korner, Heinrich; Kung, Sam K P; Fu, Yang-Xin; Uzonna, Jude E

    2007-11-15

    Although studies indicate LIGHT (lymphotoxin (LT)-like, exhibits inducible expression and competes with HSV glycoprotein D for herpes virus entry mediator (HVEM), a receptor expressed by T lymphocytes) enhances inflammation and T cell-mediated immunity, the mechanisms involved in this process remain obscure. In this study, we assessed the role of LIGHT in IL-12 production and development of CD4(+) Th cells type one (Th1) in vivo. Bone marrow-derived dendritic cells from LIGHT(-/-) mice were severely impaired in IL-12p40 production following IFN-gamma and LPS stimulation in vitro. Furthermore, blockade of LIGHT in vitro and in vivo with HVEM-Ig and LT beta receptor (LTbetaR)-Ig leads to impaired IL-12 production and defective polyclonal and Ag-specific IFN-gamma production in vivo. In an infection model, injection of HVEM-Ig or LTbetaR-Ig into the usually resistant C57BL/6 mice results in defective IL-12 and IFN-gamma production and severe susceptibility to Leishmania major that was reversed by rIL-12 treatment. This striking susceptibility to L. major in mice injected with HVEM-Ig or LTbetaR-Ig was also reproduced in LIGHT(-/-) --> RAG1(-/-) chimeric mice. In contrast, L. major-infected LTbeta(-/-) mice do not develop acute disease, suggesting that the effect of LTbetaR-Ig is not due to blockade of membrane LT (LTalpha1beta2) signaling. Collectively, our data show that LIGHT plays a critical role for optimal IL-12 production by DC and the development of IFN-gamma-producing CD4(+) Th1 cells and its blockade results in severe susceptibility to Leishmania major.

  10. Diamond functionalization with light-harvesting molecular wires: improved surface coverage by optimized Suzuki cross-coupling conditions

    Czech Academy of Sciences Publication Activity Database

    Yeap, W. S.; Bevk, D.; Liu, X.; Krýsová, Hana; Pasquarelli, A.; Vanderzande, D.; Lutsen, L.; Kavan, Ladislav; Fahlman, M.; Maes, W.; Haenen, K.

    2014-01-01

    Roč. 4, AUG 2014 (2014), s. 42044-42053 ISSN 2046-2069 R&D Projects: GA ČR GA13-31783S Institutional support: RVO:61388955 Keywords : Functionalizations * Light-harvesting * Molecular wires Subject RIV: CG - Electrochemistry Impact factor: 3.840, year: 2014

  11. The design and optimization for light-algae bioreactor controller based on Artificial Neural Network-Model Predictive Control

    Science.gov (United States)

    Hu, Dawei; Liu, Hong; Yang, Chenliang; Hu, Enzhu

    As a subsystem of the bioregenerative life support system (BLSS), light-algae bioreactor (LABR) has properties of high reaction rate, efficiently synthesizing microalgal biomass, absorbing CO2 and releasing O2, so it is significant for BLSS to provide food and maintain gas balance. In order to manipulate the LABR properly, it has been designed as a closed-loop control system, and technology of Artificial Neural Network-Model Predictive Control (ANN-MPC) is applied to design the controller for LABR in which green microalgae, Spirulina platensis is cultivated continuously. The conclusion is drawn by computer simulation that ANN-MPC controller can intelligently learn the complicated dynamic performances of LABR, and automatically, robustly and self-adaptively regulate the light intensity illuminating on the LABR, hence make the growth of microalgae in the LABR be changed in line with the references, meanwhile provide appropriate damping to improve markedly the transient response performance of LABR.

  12. Optimization of sensitometric properties of blue and green light sensitive dental radiographic films employing an automatic processor

    OpenAIRE

    Suchetha N Malleshi; Karthikeya Patil; Mahima V Guledgud

    2011-01-01

    Background: Accurate film processing is of paramount importance in acquiring a good diagnostic radiograph. Radiographic films show variations in densities and contrast, with changes in processing conditions, and also film type, all of which are interdependent. Therefore, this research was conducted to recognize the effect of time and temperature variations of automatic processor on the sensitometric properties of blue and green light sensitive screen films. The study also aimed to note the ef...

  13. Cyanobacterial flv4-2 Operon-Encoded Proteins Optimize Light Harvesting and Charge Separation in Photosystem II.

    Science.gov (United States)

    Chukhutsina, Volha; Bersanini, Luca; Aro, Eva-Mari; van Amerongen, Herbert

    2015-05-01

    Photosystem II (PSII) complexes drive the water-splitting reaction necessary to transform sunlight into chemical energy. However, too much light can damage and disrupt PSII. In cyanobacteria, the flv4-2 operon encodes three proteins (Flv2, Flv4, and Sll0218), which safeguard PSII activity under air-level CO2 and in high light conditions. However, the exact mechanism of action of these proteins has not been clarified yet. We demonstrate that the PSII electron transfer properties are influenced by the flv4-2 operon-encoded proteins. Accelerated secondary charge separation kinetics was observed upon expression/overexpression of the flv4-2 operon. This is likely induced by docking of the Flv2/Flv4 heterodimer in the vicinity of the QB pocket of PSII, which, in turn, increases the QB redox potential and consequently stabilizes forward electron transfer. The alternative electron transfer route constituted by Flv2/Flv4 sequesters electrons from QB(-) guaranteeing the dissipation of excess excitation energy in PSII under stressful conditions. In addition, we demonstrate that in the absence of the flv4-2 operon-encoded proteins, about 20% of the phycobilisome antenna becomes detached from the reaction centers, thus decreasing light harvesting. Phycobilisome detachment is a consequence of a decreased relative content of PSII dimers, a feature observed in the absence of the Sll0218 protein. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

  14. Optimizing white light luminescence in Dy3+-doped Lu3Ga5O12 nano-garnets

    International Nuclear Information System (INIS)

    Haritha, P.; Linganna, K.; Venkatramu, V.; Martín, I. R.; Monteseguro, V.; Rodríguez-Mendoza, U. R.; Babu, P.; León-Luis, S. F.; Jayasankar, C. K.; Lavín, V.

    2014-01-01

    Trivalent dysprosium-doped Lu 3 Ga 5 O 12 nano-garnets have been prepared by sol-gel method and characterized by X-ray powder diffraction, high-resolution transmission electron microscopy, dynamic light scattering, and laser excited spectroscopy. Under a cw 457 nm laser excitation, the white luminescence properties of Lu 3 Ga 5 O 12 nano-garnets have been studied as a function of the optically active Dy 3+ ion concentration and at low temperature. Decay curves for the 4 F 9/2 level of Dy 3+ ion exhibit non-exponential nature for all the Dy 3+ concentrations, which have been well-fitted to a generalized energy transfer model for a quadrupole-quadrupole interaction between Dy 3+ ions without diffusion. From these data, a simple rate-equations model can be applied to predict that intense white luminescence could be obtained from 1.8 mol% Dy 3+ ions-doped nano-garnets, which is in good agreement with experimental results. Chromaticity color coordinates and correlated color temperatures have been determined as a function of temperature and are found to be within the white light region for all Dy 3+ concentrations. These results indicate that 2.0 mol% Dy 3+ ions doped nano-garnet could be useful for white light emitting device applications

  15. The effects of food presentation and microhabitat upon resource monopoly in a ground-foraging ant (Hymenoptera: Formicidae community

    Directory of Open Access Journals (Sweden)

    Terrence P McGlynn

    2000-06-01

    Full Text Available In Neotropical wet forests several species of omnivorous, resource-defending ants, live and forage in close proximity to one another. Although the forest floor is heterogeneous in microhabitat and food quantity, little is known about the impact of microhabitat and food variation upon resource monopoly among ants. We investigated how food type and microhabitat influence food monopoly in resource-defending ants in old-growth tropical wet forest in the Caribbean lowlands of Costa Rica. We measured several microhabitat characteristics at 66 points in a 0.5 hectare plot, and baited each point with two categories of tuna bait. These baits were presented in "split" and "clumped" arrangements. We measured the frequency of bait monopoly by a single species, as well as the number of recruited ant foragers at a bait. Out of five common species, two (Wasmannia auropunctata and Pheidole simonsi more frequently monopolized one bait type over the other, and one (P. simonsi recruited more ants to the split baits. We then considered the recruitment response by all ant species in the community. We found that the frequency of monopoly, sharing, and the absence of ants at a given point in the rainforest differed with bait type. The frequency of monopoly was associated with microhabitat type in two out of eight microhabitat variables (leaf litter depth and palms; variation in two other types (canopy tree distance and leafcutter ant trails was associated with changes in forager number. In at least two ant species, food presentation affected monopoly at baits; among all resource-defending ants, the microhabitats where ants foraged for food and the type of food located determined in part the frequency of monopoly and the number of foragers at the food item. These results suggest that the location and presentation of food items determines in part which ant species will utilize the resource.En los bosques húmedos de la Región Neotropical conviven varias especies de

  16. Synergetic effect of green tea on polymer gel dosimeter and determination of optimal wavelength to choose light source for optical computed tomography

    Directory of Open Access Journals (Sweden)

    Sathiya Raj

    2016-03-01

    Full Text Available Purpose: The ultimate aim of this study is to observe the effect of Green tea as a co-antioxidant in PAGAT gel dosimeter and evaluate the appropriate light source for scanning the PAGAT and NIPAM polymer gel.Methods: Both PAGAT (Poly Acrylamide Gelatin Tetrakis hydroxyl phosphonium chloride and NIPAM (N-Isopropyl acrylamide gel were prepared in normoxic condition. The green tea extract (GTE was prepared and tested only on PAGAT. Co-60 teletherapy machine has been used for irradiation purpose, and the gel samples were scanned using UV-Visible spectrophotometer. Water equivalency of the gel has been tested in terms of their electron density, effective atomic number and Ratio of oxygen and hydrogen (O/H. We have used NIST XCOM database to test the water equivalency.Results: In this study we found that the GTE added to the gel do not respond to the given doses. By adding sugar we can enhance the sensitivity of the gel. Further investigations are required to use Green tea as a co antioxidant concentration of THPC (Tetrakis hydroxymethyl phosphonium chloride. The optimal wavelength with different region for scanning the PAGAT is 450 to 480 nm (Blue region, for NIPAM it is 540 nm and 570 nm (Green and yellow region. The PAGAT and NIPAM showed better sensitivity at 510 nm. Both gels have their effective atomic number closer to water (NIPAM-7.2, PAGAT-7.379.Conclusion: As per our results, we concluded that GTE alone is not an effective co-antioxidant for polymer gels. When the GTE is combined with sugar and THPC, it protects the gel from pre-polymerization. This study strongly suggests that the blue light is an optimal source for scanning the PAGAT and green to yellow light for NIPAM gel. Though both gels were considered as water equivalent, the PAGAT is equivalent to water and the temporal stability of this gel is higher than NIPAM.

  17. Intensification of abamectin pesticide degradation using the combination of ultrasonic cavitation and visible-light driven photocatalytic process: Synergistic effect and optimization study.

    Science.gov (United States)

    Mosleh, Soleiman; Rahimi, Mahmood Reza

    2017-03-01

    Degradation of abamectin pesticide was carried out using visible light driven Cu 2 (OH)PO 4 -HKUST-1 MOF photocatalyst through the sonophotocatalytic technique. Cu 2 (OH)PO 4 -HKUST-1 MOF as a visible-light driven photocatalyst, was synthesized and characterized by XRD, SEM, EDS and DRS. The direct bang gaps of HKUST-1 MOF and Cu 2 (OH)PO 4 -HKUST-1 MOF were estimated about 2.63 and 2.59eV, respectively, which reveals that these photocatalysts can be activated under blue light illumination. All sonophotodegradation experiments were performed using a continuous flow-loop reactor. The central composite design (CCD) methodology was applied for modeling, optimization and investigation of influence of operational parameters, i.e. irradiation time, pH, solution flow rate, oxygen flow rate, initial concentration and photocatalyst dosage on the sonophotocatalytic degradation of abamectin. The maximum degradation efficiency of 99.93% was found at optimal values as 20min, 4, 90mL/min, 0.2mL/min, 30mg/L and 0.4g/L, for irradiation time, pH, solution flow rate, oxygen flow rate, initial concentration and photocatalyst dosage, respectively. Evaluation of the synergism in the combination of ultrasonic and photocatalysis lead to a synergistic index of 2.19, which reveals that coupling of ultrasonic and photocatalysis has a greater efficiency than the sum of individual procedures for degradation of abamectin. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Optimization of the Photoanode of CdS Quantum Dot-Sensitized Solar Cells Using Light-Scattering TiO2 Hollow Spheres

    Science.gov (United States)

    Marandi, Maziar; Rahmani, Elham; Ahangarani Farahani, Farzaneh

    2017-12-01

    CdS quantum dot-sensitized solar cells (QDSCs) have been fabricated and their photoanode optimized by altering the thickness of the photoelectrode and CdS deposition conditions and applying a ZnS electron-blocking layer and TiO2 hollow spheres. Hydrothermally grown TiO2 nanocrystals (NCs) with dominant size of 20 nm were deposited as a sublayer in the photoanode with thickness in the range from 5 μm to 10 μm using a successive ionic layer adsorption and reaction (SILAR) method. The number of deposition cycles was altered over a wide range to obtain optimized sensitization. Photoanode thickness and number of CdS sensitization cycles around the optimum values were selected and used for ZnS deposition. ZnS overlayers were also deposited on the surface of the photoanodes using different numbers of cycles of the SILAR process. The best QDSC with the optimized photoelectrode demonstrated a 153% increase in efficiency compared with a similar cell with ZnS-free photoanode. Such bilayer photoelectrodes were also fabricated with different thicknesses of TiO2 sublayers and one overlayer of TiO2 hollow spheres (HSs) with external diameter of 500 nm fabricated by liquid-phase deposition with carbon spheres as template. The optimization was performed by changing the photoanode thickness using a wide range of CdS sensitizing cycles. The maximum energy conversion efficiency was increased by about 77% compared with a similar cell with HS-free photoelectrode. The reason was considered to be the longer path length of the incident light inside the photoanode and greater light absorption. A ZnS blocking layer was overcoated on the surface of the bilayer photoanode with optimized thickness. The number of CdS sensitization cycles was also changed around the optimized value to obtain the best QDSC performance. The number of ZnS deposition cycles was also altered in a wide range for optimization of the photovoltaic performance. It was shown that the maximum efficiency was increased by

  19. [Survival strategy of photosynthetic organisms. 1. Variability of the extent of light-harvesting pigment aggregation as a structural factor optimizing the function of oligomeric photosynthetic antenna. Model calculations].

    Science.gov (United States)

    Fetisova, Z G

    2004-01-01

    In accordance with our concept of rigorous optimization of photosynthetic machinery by a functional criterion, this series of papers continues purposeful search in natural photosynthetic units (PSU) for the basic principles of their organization that we predicted theoretically for optimal model light-harvesting systems. This approach allowed us to determine the basic principles for the organization of a PSU of any fixed size. This series of papers deals with the problem of structural optimization of light-harvesting antenna of variable size controlled in vivo by the light intensity during the growth of organisms, which accentuates the problem of antenna structure optimization because optimization requirements become more stringent as the PSU increases in size. In this work, using mathematical modeling for the functioning of natural PSUs, we have shown that the aggregation of pigments of model light-harvesting antenna, being one of universal optimizing factors, furthermore allows controlling the antenna efficiency if the extent of pigment aggregation is a variable parameter. In this case, the efficiency of antenna increases with the size of the elementary antenna aggregate, thus ensuring the high efficiency of the PSU irrespective of its size; i.e., variation in the extent of pigment aggregation controlled by the size of light-harvesting antenna is biologically expedient.

  20. Non-linear thermal optimization and design improvement of a new internal light concrete multi-holed brick walls by FEM

    International Nuclear Information System (INIS)

    Coz Diaz, J.J. del; Garcia Nieto, P.J.; Suarez Sierra, J.L.; Penuelas Sanchez, I.

    2008-01-01

    The aim of this work was carried out the optimization and numerical study by the finite element method of internal hollow bricks walls in order to determine the best candidate brick from the thermal point of view. With respect to the energy saving for housing and industrial structures, there is also a great interest in light building materials with good physical and thermal behaviors, which fulfills all thermal requirements of the new CTE Spanish rule. The conduction, convection and radiation phenomena are taking into account in this study for six different types of bricks varying the material conductivity obtained from five experimental tests. Mathematically, the non-linearity is due to the radiation boundary condition inside the inner recesses of the bricks. Optimization of the walls is carried out from the finite element analysis of the new hollow brick geometries by means of the average mass overall thermal efficiency and the equivalent thermal conductivity. Based on the previous thermal analysis and the optimization procedure described in this paper, the best candidate was chosen and then a full 1.22 x 0.23 x 1.05 m wall made of these bricks was simulated for fifteen different compositions. The main variables influencing the thermal conductivity of these walls are illustrated for different concrete and mortar properties and the temperature distribution is shown for some typical configurations. Finally, in order to select the appropriate wall satisfying the CTE requirements, detailed instructions are given and conclusions of this work are exposed

  1. Non-linear thermal optimization and design improvement of a new internal light concrete multi-holed brick walls by FEM

    Energy Technology Data Exchange (ETDEWEB)

    Del Coz Diaz, J.J.; Suarez Sierra, J.L.; Penuelas Sanchez, I. [Edificio Departamental Viesques, No. 7-33204 Gijon, Asturias (Spain); Garcia Nieto, P.J. [Departamento de Matematicas, Facultad de Ciencias, C/Calvo Sotelo s/n, 33007 Oviedo, Asturias (Spain)

    2008-06-15

    The aim of this work was carried out the optimization and numerical study by the finite element method of internal hollow bricks walls in order to determine the best candidate brick from the thermal point of view. With respect to the energy saving for housing and industrial structures, there is also a great interest in light building materials with good physical and thermal behaviors, which fulfills all thermal requirements of the new CTE Spanish rule. The conduction, convection and radiation phenomena are taking into account in this study for six different types of bricks varying the material conductivity obtained from five experimental tests. Mathematically, the non-linearity is due to the radiation boundary condition inside the inner recesses of the bricks. Optimization of the walls is carried out from the finite element analysis of the new hollow brick geometries by means of the average mass overall thermal efficiency and the equivalent thermal conductivity. Based on the previous thermal analysis and the optimization procedure described in this paper, the best candidate was chosen and then a full 1.22 x 0.23 x 1.05 m wall made of these bricks was simulated for fifteen different compositions. The main variables influencing the thermal conductivity of these walls are illustrated for different concrete and mortar properties and the temperature distribution is shown for some typical configurations. Finally, in order to select the appropriate wall satisfying the CTE requirements, detailed instructions are given and conclusions of this work are exposed. (author)

  2. Non-linear thermal optimization and design improvement of a new internal light concrete multi-holed brick walls by FEM

    Energy Technology Data Exchange (ETDEWEB)

    Coz Diaz, J.J. del [Edificio Departamental Viesques, No. 7-33204 Gijon, Asturias (Spain)], E-mail: juanjo@constru.uniovi.es; Garcia Nieto, P.J. [Departamento de Matematicas, Facultad de Ciencias, C/Calvo Sotelo s/n, 33007 Oviedo, Asturias (Spain); Suarez Sierra, J.L.; Penuelas Sanchez, I. [Edificio Departamental Viesques, No. 7-33204 Gijon, Asturias (Spain)

    2008-06-15

    The aim of this work was carried out the optimization and numerical study by the finite element method of internal hollow bricks walls in order to determine the best candidate brick from the thermal point of view. With respect to the energy saving for housing and industrial structures, there is also a great interest in light building materials with good physical and thermal behaviors, which fulfills all thermal requirements of the new CTE Spanish rule. The conduction, convection and radiation phenomena are taking into account in this study for six different types of bricks varying the material conductivity obtained from five experimental tests. Mathematically, the non-linearity is due to the radiation boundary condition inside the inner recesses of the bricks. Optimization of the walls is carried out from the finite element analysis of the new hollow brick geometries by means of the average mass overall thermal efficiency and the equivalent thermal conductivity. Based on the previous thermal analysis and the optimization procedure described in this paper, the best candidate was chosen and then a full 1.22 x 0.23 x 1.05 m wall made of these bricks was simulated for fifteen different compositions. The main variables influencing the thermal conductivity of these walls are illustrated for different concrete and mortar properties and the temperature distribution is shown for some typical configurations. Finally, in order to select the appropriate wall satisfying the CTE requirements, detailed instructions are given and conclusions of this work are exposed.

  3. Spatial prediction and validation of zoonotic hazard through micro-habitat properties: where does Puumala hantavirus hole - up?

    Science.gov (United States)

    Khalil, Hussein; Olsson, Gert; Magnusson, Magnus; Evander, Magnus; Hörnfeldt, Birger; Ecke, Frauke

    2017-07-26

    To predict the risk of infectious diseases originating in wildlife, it is important to identify habitats that allow the co-occurrence of pathogens and their hosts. Puumala hantavirus (PUUV) is a directly-transmitted RNA virus that causes hemorrhagic fever in humans, and is carried and transmitted by the bank vole (Myodes glareolus). In northern Sweden, bank voles undergo 3-4 year population cycles, during which their spatial distribution varies greatly. We used boosted regression trees; a technique inspired by machine learning, on a 10 - year time-series (fall 2003-2013) to develop a spatial predictive model assessing seasonal PUUV hazard using micro-habitat variables in a landscape heavily modified by forestry. We validated the models in an independent study area approx. 200 km away by predicting seasonal presence of infected bank voles in a five-year-period (2007-2010 and 2015). The distribution of PUUV-infected voles varied seasonally and inter-annually. In spring, micro-habitat variables related to cover and food availability in forests predicted both bank vole and infected bank vole presence. In fall, the presence of PUUV-infected voles was generally restricted to spruce forests where cover was abundant, despite the broad landscape distribution of bank voles in general. We hypothesize that the discrepancy in distribution between infected and uninfected hosts in fall, was related to higher survival of PUUV and/or PUUV-infected voles in the environment, especially where cover is plentiful. Moist and mesic old spruce forests, with abundant cover such as large holes and bilberry shrubs, also providing food, were most likely to harbor infected bank voles. The models developed using long-term and spatially extensive data can be extrapolated to other areas in northern Fennoscandia. To predict the hazard of directly transmitted zoonoses in areas with unknown risk status, models based on micro-habitat variables and developed through machine learning techniques in

  4. Greater sage-grouse (Centrocercus urophasianus) nesting and brood-rearing microhabitat in Nevada and California—Spatial variation in selection and survival patterns

    Science.gov (United States)

    Coates, Peter S.; Brussee, Brianne E.; Ricca, Mark A.; Dudko, Jonathan E.; Prochazka, Brian G.; Espinosa, Shawn P.; Casazza, Michael L.; Delehanty, David J.

    2017-08-10

    Greater sage-grouse (Centrocercus urophasianus; hereinafter, "sage-grouse") are highly dependent on sagebrush (Artemisia spp.) dominated vegetation communities for food and cover from predators. Although this species requires the presence of sagebrush shrubs in the overstory, it also inhabits a broad geographic distribution with significant gradients in precipitation and temperature that drive variation in sagebrush ecosystem structure and concomitant shrub understory conditions. Variability in understory conditions across the species’ range may be responsible for the sometimes contradictory findings in the scientific literature describing sage-grouse habitat use and selection during important life history stages, such as nesting. To help understand the importance of this variability and to help guide management actions, we evaluated the nesting and brood-rearing microhabitat factors that influence selection and survival patterns in the Great Basin using a large dataset of microhabitat characteristics from study areas spanning northern Nevada and a portion of northeastern California from 2009 to 2016. The spatial and temporal coverage of the dataset provided a powerful opportunity to evaluate microhabitat factors important to sage-grouse reproduction, while also considering habitat variation associated with different climatic conditions and areas affected by wildfire. The summary statistics for numerous microhabitat factors, and the strength of their association with sage-grouse habitat selection and survival, are provided in this report to support decisions by land managers, policy-makers, and others with the best-available science in a timely manner.

  5. Optimization of a readout board for mass assembly and light yield measurements with a cosmic ray test stand

    Energy Technology Data Exchange (ETDEWEB)

    Chau, Phi [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik (Germany); Collaboration: CALICE-D-Collaboration

    2016-07-01

    We have built a readout board prototype, equipped with SiPMs, scintillators and readout electronics for an highly granular calorimeter. The design was optimized for mass assembly due to about 8 million channels in the final detector. The prototype showed good performance in several test beams and in a cosmic ray test stand, which was built to characterize the MIP response of these kinds of boards. We show an overview of the cosmic ray test stand and measurement results for the readout board and plans for an improved 2nd generation prototype.

  6. Measurement and optimization of the light collection uniformity in strongly tapered PWO crystals of the PANDA detector

    Science.gov (United States)

    Diehl, Stefan; Bremer, Daniel; Brinkmann, Kai-Thomas; Dormenev, Valery; Eissner, Tobias; Novotny, Rainer W.; Rosenbaum, Christoph; Zaunick, Hans-Georg; PANDA Collaboration

    2017-06-01

    The uniformity of the light collection is a crucial parameter for detectors based on inorganic scintillation crystals to guarantee a response proportional to the deposited energy. Especially in case of tapered crystals, like they are widely used to realize a 4π geometry of electromagnetic calorimeters (EMC) in high energy physics experiments, a strong non-uniformity is introduced by an additional focusing of the scintillation light due to the tapered geometry. The paper will discuss the determination and the reduction of the non-uniformity in strongly tapered lead tungstate crystals as used for the construction of the electromagnetic calorimeter of the PANDA detector at the future Facility for Antiproton and Ion Research (FAIR). Among different concepts for an uniformization a single de-polished lateral side face provided the optimum result with a remaining non-uniformity below 5% in good agreement with similar studies for the CMS ECAL at LHC. The impact on the achievable energy resolution in the energy regime of photons below 800 MeV is discussed in detail in comparison to GEANT4 simulations. The comparison of the response of two arrays with polished and de-polished crystals, respectively, shows in the latter case a significant improvement of the constant term of the parametrization of the energy resolution down to 0.5% accompanied by only very slight increase of the statistical term.

  7. Measurement and optimization of the light collection uniformity in strongly tapered PWO crystals of the PANDA detector

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, Stefan; Bremer, Daniel; Brinkmann, Kai-Thomas; Dormenev, Valery; Eissner, Tobias; Novotny, Rainer W.; Rosenbaum, Christoph; Zaunick, Hans-Georg

    2017-06-11

    The uniformity of the light collection is a crucial parameter for detectors based on inorganic scintillation crystals to guarantee a response proportional to the deposited energy. Especially in case of tapered crystals, like they are widely used to realize a 4π geometry of electromagnetic calorimeters (EMC) in high energy physics experiments, a strong non-uniformity is introduced by an additional focusing of the scintillation light due to the tapered geometry. The paper will discuss the determination and the reduction of the non-uniformity in strongly tapered lead tungstate crystals as used for the construction of the electromagnetic calorimeter of the PANDA detector at the future Facility for Antiproton and Ion Research (FAIR). Among different concepts for an uniformization a single de-polished lateral side face provided the optimum result with a remaining non-uniformity below 5% in good agreement with similar studies for the CMS ECAL at LHC. The impact on the achievable energy resolution in the energy regime of photons below 800 MeV is discussed in detail in comparison to GEANT4 simulations. The comparison of the response of two arrays with polished and de-polished crystals, respectively, shows in the latter case a significant improvement of the constant term of the parametrization of the energy resolution down to 0.5% accompanied by only very slight increase of the statistical term.

  8. Microhabitats de mosquitos (Diptera, Culicidae em internódios de taquara na Mata Atlântica, Paraná, Brasil Mosquitoes microhabitats (Diptera, Culicidae in bamboo internodes in Atlantic forest, Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Ana Leuch Lozovei

    Full Text Available During two consecutive years, from January 1985 to December 1986, a comparative study of mosquitoes preferences for breeding habitat was carried out in the Atlantic Forest of the Serra do Mar, Paraná State, Brazil. To achieve it, 1875 bamboo internodes aligned vertically in live green, bamboo plants Merostachys speciosa Munro and Merostachys sp. were used, in which metabolic water was exuded from the plant itself, and presenting different size/pattern holes at their lateral walls, bored by the local sylvan fauna. Another group of 1200 individual internode traps was used as comparative element, carved out with a transversal cut by a saw, filled with local stream water and held in branches at different heights in the vegetal strata nearby. At both microhabitat types, a total of 17 culicid species was registered. Culex (Microculex neglectus Lutz, 1904, Cx. (Carrollia soperi Antunes & Lane, 1937, Sabethes (Sabethes batesi Lane & Cerqueira, 1942 and Sa. (Sabethinus melanonymphe (Dyar, 1924colonized exclusively live plant internodes, while Culex (Microculex elongatus Rozeboom & Lane, 1950, Cx. (Carrollia iridescens (Lutz, 1905, Cx. (Carrollia kompi Valencia,1973and Trichoprosopon (Trichoprosopon soaresi Dyar & Knab, 1907 bred only in internode traps. The remaining nine species colonized both habitats indistinctly. Quantitatively, was detected the abundance of 60.1% at live green internodes, against 39.9% for internode traps. Concerning the different patterns of bored live internode holes, 40.3% of the total computed specimens were collected in square or rectangular holes, 31.9% in two hole internodes, one minute circular, the other wider, and the remaining 28.8% of specimens distributed in other pattern type internodes. The mosquitoes breeding at these microhabitats fall in the culicid entomofauna specialized at locating and detecting peculiar and propitious mesogen conditions for breeding purposes.

  9. Lichensphere: a protected natural microhabitat of the non-lichenised fungal communities living in extreme environments of Antarctica.

    Science.gov (United States)

    Santiago, Iara F; Soares, Marco Aurélio; Rosa, Carlos A; Rosa, Luiz H

    2015-11-01

    We surveyed the diversity, distribution and ecology of non-lichenised fungal communities associated with the Antarctic lichens Usnea antarctica and Usnea aurantiaco-atra across Antarctica. The phylogenetic study of the 438 fungi isolates identified 74 taxa from 21 genera of Ascomycota, Basidiomycota and Zygomycota. The most abundant taxa were Pseudogymnoascus sp., Thelebolus sp., Antarctomyces psychrotrophicus and Cryptococcus victoriae, which are considered endemic and/or highly adapted to Antarctica. Thirty-five fungi may represent new and/or endemic species. The fungal communities displayed high diversity, richness and dominance indices; however, the similarity among the communities was variable. After discovering rich and diverse fungal communities composed of symbionts, decomposers, parasites and endemic and cold-adapted cosmopolitan taxa, we introduced the term "lichensphere". We hypothesised that the lichensphere may represent a protected natural microhabitat with favourable conditions able to help non-lichenised fungi and other Antarctic life forms survive and disperse in the extreme environments of Antarctica.

  10. Selecting the optimal synthesis parameters of InP/CdxZn1-xSe quantum dots for a hybrid remote phosphor white LED for general lighting applications.

    Science.gov (United States)

    Ryckaert, Jana; Correia, António; Tessier, Mickael D; Dupont, Dorian; Hens, Zeger; Hanselaer, Peter; Meuret, Youri

    2017-11-27

    Quantum dots can be used in white LEDs for lighting applications to fill the spectral gaps in the combined emission spectrum of the blue pumping LED and a broad band phosphor, in order to improve the source color rendering properties. Because quantum dots are low scattering materials, their use can also reduce the amount of backscattered light which can increase the overall efficiency of the white LED. The absorption spectrum and narrow emission spectrum of quantum dots can be easily tuned by altering their synthesis parameters. Due to the re-absorption events between the different luminescent materials and the light interaction with the LED package, determining the optimal quantum dot properties is a highly non-trivial task. In this paper we propose a methodology to select the optimal quantum dot to be combined with a broad band phosphor in order to realize a white LED with optimal luminous efficacy and CRI. The methodology is based on accurate and efficient simulations using the extended adding-doubling approach that take into account all the optical interactions. The method is elaborated for the specific case of a hybrid, remote phosphor white LED with YAG:Ce phosphor in combination with InP/CdxZn 1-x Se type quantum dots. The absorption and emission spectrum of the quantum dots are generated in function of three synthesis parameters (core size, shell size and cadmium fraction) by a semi-empirical 'quantum dot model' to include the continuous tunability of these spectra. The sufficiently fast simulations allow to scan the full parameter space consisting of these synthesis parameters and luminescent material concentrations in terms of CRI and efficacy. A conclusive visualization of the final performance allows to make a well-considered trade-off between these performance parameters. For the hybrid white remote phosphor LED with YAG:Ce and InP/CdxZn 1-x Se quantum dots a CRI Ra = 90 (with R9>50) and an overall efficacy of 110 lm/W is found.

  11. Seedling recruitment of forb species under experimental microhabitats in alpine grassland

    International Nuclear Information System (INIS)

    Li, S. S.; Yu, L.; Lin, W. G.; Pingi, T. F.

    2015-01-01

    Which factors limit plant seedling recruitment in alpine meadow of the Qinghai-Tibetan Plateau (QTP), China? This study examined the relative influence of seed mass and microsites (resulted from grazing disturbance) on field seedling emergence and survival of nineteen alpine herbaceous species with a range of traits in QTP. Seed mass had significant effects on seedling emergence and survival eliminating influence of light and nutrient variances among these species. The larger-seed species had more advantageous than the smaller-seed species in seedling survival, but it was disadvatage for seedling emergence, especially under high nutrient availability and low light intensity conditions. Light had obvious effects on seedling survival, but less effects on seedling emergence for these species. Moreover, nutrient and light treatments altered the regression relationships of seed mass and seedling emergence and survival and the order of significances was L25>L50>L100>L10>L4. These results suggested that seed mass may restrict seedling recruitment processes, however, light and nutrient availability all have significant effects on seedling emergence and survival for these alpine species. Moderate light intensity was propitious to seedling emergence and survival in alpine grassland. This suggests that ecological factors in alpine grassland provide a stochastic influence on different seed-mass species. These trends may help to explain why many small-seeded species of Asteraceae and Gramineae tend to be more abundant in disturbed habitats. (author)

  12. [Relative abundance and microhabitat use by the frog Geobatrachus walkeri (Anura: Strabomantidae) in two habitats of Sierra Nevada de Santa Marta, Colombia].

    Science.gov (United States)

    Martínez Baños, Vera; Pacheco Florez, Vanesa; Ramírez-Pinilla, Martha P

    2011-06-01

    Geobatrachus walkeri belongs to a monotypic frog genus endemic to the San Lorenzo area, Sierra Nevada de Santa Marta, Colombia. This species has been categorized as endangered because of its small distribution area and the decline in the extent and quality of its habitat. It inhabits two forest types with different composition and structure, the native secondary forest and a pine plantation (dominated by Pinus patula). To compare the relative abundance and microhabitat use of this species in these habitat types, 30 quadrants/environment were distributed randomly. The individual number, microhabitat use and other aspects of its natural history were registered using visual encounter surveys in both sites, including non-sampled areas in the quadrants. The relative abundance of frogs was significantly different between habitats and among seasons. The highest abundance of G. walkeri relative to the total area was found in the pine plantation, being 2.3 times higher than in the natural forest. More frogs were significantly found during the rainy season; nevertheless, active individuals were also found during the dry season. Significant differences were found in the microhabitat use with respect to the forest type and season. The most frequently microhabitat used in the two forest types was the pine leaf-litter; besides, in the native forest, the microhabitat occupied more frequently presented medium and large size stones. Geobatrachus walkeri is a successful species in pine plantations, associated permanently to its leaf-litter environment where it seems to develop its entire life cycle. The clear modifications in the soils and water, derived from the introduction of the pine plantation in this area, seem not to have negatively affected the conservation and successful maintenance of this species.

  13. Spawning areas, dispersion and microhabitats of fish larvae in the Anavilhanas Ecological Station, rio Negro, Amazonas State, Brazil

    Directory of Open Access Journals (Sweden)

    Edinbergh C. de Oliveira

    Full Text Available The abundance and distribution of ichthyoplankton and their relationships to current velocity, temperature, dissolved oxygen, pH and electrical conductivity of the water in the Anavilhanas Ecological Station, Negro River, Amazonas State, Brazil, were analyzed. Preferred microhabitats for spawning, dispersion and nursery were also verified. Sampling was undertaken during the falling water period of 2001 and the rising water period of 2002, in a section of 100 km subdivided into 5 subsections, with a total of 20 stations (5 beaches, 5 ravines, 5 channels, and 5 lake channels at night and during the day at the surface and at the bottom. 647 eggs and 4,187 larvae were captured, belonging to 10 families and four orders: Characiformes (6, Siluriformes (2, Perciformes (1, and Clupeiformes (1. Engraulidae (55.39%, Pimelodidae (30.45%, Auchenipteridae (5.23% and Sciaenidae (5.13% were the dominant families. The hierarchical statistical model (ANOVA with three factors (microhabitat, depth and period was applied to the environmental variables and the larval abundance, showing greater abundances of sciaenids in the ravines and lower abundances of engraulids in the channels. The highest captures were obtained at lower temperature values, at the bottom during the day and at the surface at night, suggesting an active larval behavior. The presence of the four larval development stages in all subsection for pimelodids and sciaenids, and in three subsections for engraulids, indicates that the Anavilhanas Ecological Station is an important spawning and nursery area for species of these groups in the Negro River. Larvae abundance of all characiform families was extremely low (from 0.1 to 1.17%, suggesting that they do not spawn in this system.

  14. Modulation of digestive physiology and biochemistry in Mytilus californianus in response to feeding level acclimation and microhabitat

    Directory of Open Access Journals (Sweden)

    Kwasi M. Connor

    2016-09-01

    Full Text Available The intertidal mussel Mytilus californianus is a critical foundation species that is exposed to fluctuations in the environment along tidal- and wave-exposure gradients. We investigated feeding and digestion in mussels under laboratory conditions and across environmental gradients in the field. We assessed whether mussels adopt a rate-maximization (higher ingestion and lower assimilation or a yield-maximization acquisition (lower ingestion and higher assimilation strategy under laboratory conditions by measuring feeding physiology and digestive enzyme activities. We used digestive enzyme activity to define resource acquisition strategies in laboratory studies, then measured digestive enzyme activities in three microhabitats at the extreme ends of the tidal- and wave-exposure gradients within a stretch of shore (<20 m projected sea-ward. Our laboratory results indicated that mussels benefit from a high assimilation efficiency when food concentration is low and have a low assimilation efficiency when food concentration is high. Additionally, enzyme activities of carbohydrases amylase, laminarinase and cellulase were elevated when food concentration was high. The protease trypsin, however, did not increase with increasing food concentration. In field conditions, low-shore mussels surprisingly did not have high enzyme activities. Rather, high-shore mussels exhibited higher cellulase activities than low-shore mussels. Similarly, trypsin activity in the high-shore-wave-sheltered microhabitat was higher than that in high-shore-wave-exposed. As expected, mussels experienced increasing thermal stress as a function of reduced submergence from low to high shore and shelter from wave-splash. Our findings suggest that mussels compensate for limited feeding opportunities and thermal stress by modulating digestive enzyme activities.

  15. Optimization of the Orbiting Wide-Angle Light Collectors (OWL) Mission for Charged-Particle and Neutrino Astronomy

    Science.gov (United States)

    Krizmanic, John F.; Mitchell, John W.; Streitmatter, Robert E.

    2013-01-01

    OWL [1] uses the Earth's atmosphere as a vast calorimeter to fully enable the emerging field of charged-particle astronomy with high-statistics measurements of ultra-high-energy cosmic rays (UHECR) and a search for sources of UHE neutrinos and photons. Confirmation of the Greisen-Zatsepin-Kuzmin (GZK) suppression above approx. 4 x 10(exp 19) eV suggests that most UHECR originate in astrophysical objects. Higher energy particles must come from sources within about 100 Mpc and are deflected by approx. 1 degree by predicted intergalactic/galactic magnetic fields. The Pierre Auger Array, Telescope Array and the future JEM-EUSO ISS mission will open charged-particle astronomy, but much greater exposure will be required to fully identify and measure the spectra of individual sources. OWL uses two large telescopes with 3 m optical apertures and 45 degree FOV in near-equatorial orbits. Simulations of a five-year OWL mission indicate approx. 10(exp 6) sq km/ sr/ yr of exposure with full aperture at approx. 6 x 10(exp 19) eV. Observations at different altitudes and spacecraft separations optimize sensitivity to UHECRs and neutrinos. OWL's stereo event reconstruction is nearly independent of track inclination and very tolerant of atmospheric conditions. An optional monocular mode gives increased reliability and can increase the instantaneous aperture. OWL can fully reconstruct horizontal and upward-moving showers and so has high sensitivity to UHE neutrinos. New capabilities in inflatable structures optics and silicon photomultipliers can greatly increase photon sensitivity, reducing the energy threshold for n detection or increasing viewed area using a higher orbit. Design trades between the original and optimized OWL missions and the enhanced science capabilities are described.

  16. Optimism about safety and group-serving interpretations of safety among pedestrians and cyclists in relation to road use in general and under low light conditions.

    Science.gov (United States)

    King, M J; Wood, J M; Lacherez, P F; Marszalek, R P

    2012-01-01

    Drivers are known to be optimistic about their risk of crash involvement, believing that they are less likely to be involved in a crash than other drivers. However, little comparative research has been conducted among other road users. In addition, optimism about crash risk is conceptualised as applying only to an individual's assessment of his or her personal risk of crash involvement. The possibility that the self-serving nature of optimism about safety might be generalised to the group-level as a cyclist or a pedestrian, i.e., becoming group-serving rather than self-serving, has been overlooked in relation to road safety. This study analysed a subset of data collected as part of a larger research project on the visibility of pedestrians, cyclists and road workers, focusing on a set of questionnaire items administered to 406 pedestrians, 838 cyclists and 622 drivers. The items related to safety in various scenarios involving drivers, pedestrians and cyclists, allowing predictions to be derived about group differences in agreement with items based on the assumption that the results would exhibit group-serving bias. Analysis of the responses indicated that specific hypotheses about group-serving interpretations of safety and responsibility were supported in 22 of the 26 comparisons. When the nine comparisons relevant to low lighting conditions were considered separately, seven were found to be supported. The findings of the research have implications for public education and for the likely acceptance of messages which are inconsistent with current assumptions and expectations of pedestrians and cyclists. They also suggest that research into group-serving interpretations of safety, even for temporary roles rather than enduring groups, could be fruitful. Further, there is an implication that gains in safety can be made by better educating road users about the limitations of their visibility and the ramifications of this for their own road safety, particularly in low

  17. Egg-laying substrate selection for optimal camouflage by quail.

    Science.gov (United States)

    Lovell, P George; Ruxton, Graeme D; Langridge, Keri V; Spencer, Karen A

    2013-02-04

    Camouflage is conferred by background matching and disruption, which are both affected by microhabitat. However, microhabitat selection that enhances camouflage has only been demonstrated in species with discrete phenotypic morphs. For most animals, phenotypic variation is continuous; here we explore whether such individuals can select microhabitats to best exploit camouflage. We use substrate selection in a ground-nesting bird (Japanese quail, Coturnix japonica). For such species, threat from visual predators is high and egg appearance shows strong between-female variation. In quail, variation in appearance is particularly obvious in the amount of dark maculation on the light-colored shell. When given a choice, birds consistently selected laying substrates that made visual detection of their egg outline most challenging. However, the strategy for maximizing camouflage varied with the degree of egg maculation. Females laying heavily maculated eggs selected the substrate that more closely matched egg maculation color properties, leading to camouflage through disruptive coloration. For lightly maculated eggs, females chose a substrate that best matched their egg background coloration, suggesting background matching. Our results show that quail "know" their individual egg patterning and seek out a nest position that provides most effective camouflage for their individual phenotype. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Design optimization of a compact photonic crystal microcavity based on slow light and dispersion engineering for the miniaturization of integrated mode-locked lasers

    Directory of Open Access Journals (Sweden)

    Malik Kemiche

    2018-01-01

    Full Text Available We exploit slow light (high ng modes in planar photonic crystals in order to design a compact cavity, which provides an attractive path towards the miniaturization of near-infrared integrated fast pulsed lasers. By applying dispersion engineering techniques, we can design structures with a low dispersion, as needed by mode-locking operation. Our basic InP SiO2 heterostructure is robust and well suited to integrated laser applications. We show that an optimized 30 μm long cavity design yields 9 frequency-equidistant modes with a FSR of 178 GHz within a 11.5 nm bandwidth, which could potentially sustain the generation of optical pulses shorter than 700 fs. In addition, the numerically calculated quality factors of these modes are all above 10,000, making them suitable for reaching laser operation. Thanks to the use of a high group index (28, this cavity design is almost one order of magnitude shorter than standard rib-waveguide based mode-locked lasers. The use of slow light modes in planar photonic crystal based cavities thus relaxes the usual constraints that tightly link the device size and the quality (peak power, repetition rate of the pulsed laser signal.

  19. Design optimization of a compact photonic crystal microcavity based on slow light and dispersion engineering for the miniaturization of integrated mode-locked lasers

    Science.gov (United States)

    Kemiche, Malik; Lhuillier, Jérémy; Callard, Ségolène; Monat, Christelle

    2018-01-01

    We exploit slow light (high ng) modes in planar photonic crystals in order to design a compact cavity, which provides an attractive path towards the miniaturization of near-infrared integrated fast pulsed lasers. By applying dispersion engineering techniques, we can design structures with a low dispersion, as needed by mode-locking operation. Our basic InP SiO2 heterostructure is robust and well suited to integrated laser applications. We show that an optimized 30 μm long cavity design yields 9 frequency-equidistant modes with a FSR of 178 GHz within a 11.5 nm bandwidth, which could potentially sustain the generation of optical pulses shorter than 700 fs. In addition, the numerically calculated quality factors of these modes are all above 10,000, making them suitable for reaching laser operation. Thanks to the use of a high group index (28), this cavity design is almost one order of magnitude shorter than standard rib-waveguide based mode-locked lasers. The use of slow light modes in planar photonic crystal based cavities thus relaxes the usual constraints that tightly link the device size and the quality (peak power, repetition rate) of the pulsed laser signal.

  20. Optimization of the charge-carrier injection in organic light-emitting diodes; Optimierung der Ladungstraegerinjektion in organische Leuchtdioden

    Energy Technology Data Exchange (ETDEWEB)

    Krause, Ralf

    2009-07-01

    Nowadays based on resource shortage and climate warming there is a big interest in the use of power-saving lighting sources. Therefore the research on white organic light emitting devices (OLEDs) has gained importance during the last years. To obtain high power efficiencies in OLEDs it is necessary to provide low driving voltages. That can be realised by the use of doped transport layers, in which donors and acceptors are coevaporated with organic transport materials. In this thesis I discuss novel p-type and n-type doping materials for small organic molecules which decrease the ohmic loss in organic transport layers used in OLEDs. This reduction of the resistance is caused by an increase of the intrinsic charge carrier density and therefore an increase of the conductivity. First single layer devices are used to analyse the properties of potential doping materials by varying the doping concentration. The tested p-doping materials are commercially available metal oxides (MoO{sub 3} and Re{sub 2}O{sub 7}) and metal-organic complexes. Both metal oxides show a strong conductivity improvement of up to 7 orders of magnitude. The investigated n-doping materials are alkali salts, metal-organic and organic complexes. Among the alkali salts Cs{sub 2}CO{sub 3} is the best material in test with a conductivity enhancement of up to 7 orders of magnitude. For this material class I focused on the question whether the metal cation or the organic anion causes the doping effect. Using similar Caesium salts differently strong doping effects were obtained. Therefore I came to the conclusion that beside the metal cation also the anion plays a role for the doping effect. Secondly I performed a series of multilayer devices for two doping materials (Re{sub 2}O{sub 7} as acceptor and Cs{sub 2}CO{sub 3} as donor) to separate the transport and injection enhancement. The results show that a doped transport layer improves the hole or electron injection into an undoped material by several orders

  1. Clinical and preclinical validation of the serum free light chain assay: identification of the critical difference for optimized clinical use.

    Science.gov (United States)

    Hansen, Charlotte T; Münster, Anna-Marie; Nielsen, Lars; Pedersen, Per; Abildgaard, Niels

    2012-12-01

    The use of the assay for the measurements of free light chains in serum (sFLCs) is increasing. However, there are technical limitations that potentially affect the use in serial measurements. We need further knowledge on the standards of analytical precision, the utility of conventional population-based reference values and the critical difference (CD) between serial results required for significance. To answer these questions, the biological variation must be known. We determined the biological variation in healthy individuals and patients with plasma cell dyscrasia (PCD). We assessed the imprecision of the analysis in use from FreeLite™. We determined the reference interval (RI) in 170 healthy individuals. The biological variation is identical for healthy individuals and patients with PCD. The imprecision of the sFLC analysis cannot fulfil the desirable performance standards for a laboratory test, but are within the manufacturer's ±20% variation for quality control samples. RI showed a significant increase for κ FLC and κ/λ ratio with age, but not for λ. Critical difference was calculated to be 24% and 23% for κ and λ, respectively. We suggest the use of an age-dependent RI. When monitoring patients with PCD, their own former results are the best reference, and knowledge on CD is a valuable tool, which we describe for the first time. Also, it challenges the recently proposed International Myeloma Working Group 'paraprotein relapse criteria', recommending an increase of more than 25% in the involved FLC to indicate the need for initiation of retreatment. We recommend revision of this criterion. © 2012 John Wiley & Sons A/S.

  2. Where to deliver baits for deworming urban red foxes for Echinococcus multilocularis control: new protocol for micro-habitat modeling of fox denning requirements.

    Science.gov (United States)

    Ikeda, Takako; Yoshimura, Masashi; Onoyama, Keiichi; Oku, Yuzaburo; Nonaka, Nariaki; Katakura, Ken

    2014-08-06

    Deworming wild foxes by baiting with the anthelmintic praziquantel is being established as a preventive technique against environmental contamination with Echinococcus multilocularis eggs. Improvement of the cost-benefit performance of baiting treatment is required urgently to raise and maintain the efficacy of deworming. We established a spatial model of den site selection by urban red foxes, the definitive host, to specify the optimal micro-habitats for delivering baits in a new modeling approach modified for urban fox populations. The model was established for two cities (Obihiro and Sapporo) in Hokkaido, Japan, in which a sylvatic cycle of E. multilocularis is maintained. The two cities have different degrees of urbanization. The modeling process was designed to detect the best combination of key environmental factors and spatial scale that foxes pay attention to most (here named 'heeding range') when they select den sites. All possible models were generated using logistic regression analysis, with "presence" or "absence" of fox den as the objective variable, and nine landscape categories customized for urban environments as predictor variables to detect the best subset of predictors. This procedure was conducted for each of ten sizes of concentric circles from dens and control points to detect the best circle size. Out of all models generated, the most parsimonious model was selected using Akaike's Information Criterion (AIC) inspection. Our models suggest that fox dens in Obihiro are located at the center of a circle with 500 m radius including low percentages of wide roads, narrow roads, and occupied buildings, but high percentages of green covered areas; the dens in Sapporo within 300 m radius with low percentages of wide roads, occupied buildings, but high percentages of riverbeds and green covered areas. The variation of the models suggests the necessity of accumulating models for various types of cities in order to reveal the patterns of the model. Our

  3. Microhabitats de Aedes albopictus (Skuse na região do Vale do Paraíba, Estado de São Paulo, Brasil Microhabitats of Aedes albopictus (Skuse in the Paraíba Valley region of the State of S. Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Almério de Castro Gomes

    1992-04-01

    this invest igation. Aedes terrens and Ae. albopictus were the only species of genus Aedes present in the treeholes mentioned. The segregation of seven species of the treehole community was undertaken in the light of macro-habitat and microhabitat features. Thus, the distribution of Ae. albopictus was found to cover the rural, rural-urban and urban zones, but the rural-urban held the preference. Ae. albopictus never present in the residual and primary forest. The favorable factor to infestation with Ae. albopictus in lhe Paraíba Valley seems to have been the large number of natural niches made vacant by human influence. The rain has been important in the production of larvae and pupae, but the rainfall period does not coincide with the maximum production on them. The treeheles whose volume exceeded 600 ml were the most productive breeding places. The abundance of these two stages occurs in the summer and autunm. However, the highest peak was observed in the months of March and April. These seasonal variations were found to be common in both the bamboo trap and the artificial container. The temperature data suggest a limit of from 17 to 23°C for the best development of larvae. In the light of this, the strain of Ae. albopictus studied seems to have originated in tropical Asia. Just as happaned with Ae. aegypti it may become an important epidemiological vector for the dengue fever and provide links for yellow fever transmission in Brazil.

  4. Habitat manipulation of Exposed Riverine Sediments (ERS) how does microhabitat, microclimate and food availability influence beetle distributions?

    Science.gov (United States)

    Henshall, S. E.; Sadler, J. P.; Hannah, D. M.

    2009-04-01

    Exposed riverine sediments (ERS) are frequently inundated areas of relatively un-vegetated, fluvially deposited sediment (sand, silt, gravel and pebble). These habitats provide an important interface allowing the interaction of aquatic and terrestrial habitats and species. ERS are highly valuable for many rare and specialist invertebrates particularly beetles. Within an area of ERS, beetle species richness tends to be highest along the water's edge. This higher species richness may be linked to: (1) the availability of food items in the form of emerging and stranded aquatic invertebrates and (2) favourable physical microhabitat conditions in terms of temperature and moisture. This paper explores the role of microclimate and food availability by creating areas of ‘water's edge' habitat in the centre of a gravel bar. Typically these areas are drier, reach higher temperatures and devoid of emerging aquatic invertebrate prey. Four 2m x 2m experimental plots were created: one wet plot, one wet- fed plot, one dry-fed plot and one dry plot (control). These plots were each replicated on three separate areas of ERS. Sixty colour marked ERS specialist ground beetles (Bembidion atrocaeruleum) were released into each plot to monitor beetle persistence and movement on and between plots. The plots were maintained wet using a capillary pump system, and fed with dried blood worms for 30 days. Sediment temperature (0.05 m depth) was measured at 15 minute intervals and spot measurements of surface temperature were taken daily. A hand search was carried out on 25% of each plot after 7, 14, 21 and 30 days. Significant temperature differences were observed between the wet and dry sediment and air temperature. The wet plots on average were 1.8oC cooler than the dry plots and had a reduced temperature range. Both wet and dry sediments remained significantly warmer than air temperature. The wet and wet-fed plots yielded significantly greater numbers of beetles and marked beetles than

  5. Quantifying anuran microhabitat use to infer the potential for parasite transmission between invasive cane toads and two species of Australian native frogs.

    Directory of Open Access Journals (Sweden)

    Lígia Pizzatto

    Full Text Available Parasites that are carried by invasive species can infect native taxa, with devastating consequences. In Australia, invading cane toads (Rhinella marina carry lungworm parasites (Rhabdias pseudosphaerocephala that (based on previous laboratory studies can infect native treefrogs (Litoria caerulea and L. splendida. To assess the potential of parasite transmission from the invader to the native species (and from one infected native frog to another, we used surveys and radiotelemetry to quantify anuran microhabitat use, and proximity to other anurans, in two sites in tropical Australia. Unsurprisingly, treefrogs spent much of their time off the ground (especially by day, and in undisturbed forests but terrestrial activity was common at night (especially in anthropogenically modified habitats. Microhabitat overlap between cane toads and frogs was generally low, except at night in disturbed areas, whereas overlap between the two frog species was high. The situations of highest overlap, and hence with the greatest danger of parasite transmission, involve aggregations of frogs within crevices by day, and use of open ground by all three anuran species at night. Overall, microhabitat divergence between toads and frogs should reduce, but not eliminate, the transmission of lungworms from invasive toads to vulnerable native frogs.

  6. Near-optimal light spanners

    DEFF Research Database (Denmark)

    Chechik, Shiri; Wulff-Nilsen, Christian

    2016-01-01

    A spanner if of a weighted undirected graph G is a "sparse" subgraph that approximately preserves distances between every pair of vertices in G. We refer to if as a δ-spanner of G for some parameter δ ≥ 1 if the distance in H between every vertex pair is at most a factor δ bigger than in G. In th...

  7. Temporal pattern of foraging and microhabitat use by Galápagos marine iguanas, Amblyrhynchus cristatus.

    Science.gov (United States)

    Buttemer, William A; Dawson, William R

    1993-10-01

    We observed a colony of marine iguanas (Amblyrhynchus cristatus) on Isla Fernandina, Galápagos, Ecuador, while measuring local micrometeorological and tidal conditions. We found size-related differences in foraging mode, with smaller iguanas feeding intertidally during daytime low tides and larger iguanas feeding subtidally. Despite having greater opportunity, subtidal foragers did not time their foraging bouts or exploit their environment in ways that optimized their period at high body temperature. Instead, the foraging schedule of these iguanas served to maximize their rate of rewarming following emergence from the cool sea. Intertidal feeders, by contrast, showed much greater behavioral flexibility in attempting to exploit their thermal environment. We suggest that size-ordered differences in marine iguana thermoregulatory behavior reflect underlying ontogenetic changes in costs and benefits of thermoregulation due to differences in predator pressure, quantity of food and electrolytes taken at each feeding, mode of foraging, and agonistic tendencies.

  8. Image matching in Bayer raw domain to de-noise low-light still images, optimized for real-time implementation

    Science.gov (United States)

    Romanenko, I. V.; Edirisinghe, E. A.; Larkin, D.

    2013-03-01

    Temporal accumulation of images is a well-known approach to improve signal to noise ratios of still images taken in a low light conditions. However, the complexity of known algorithms often leads to high hardware resource usage, increased memory bandwidth and computational complexity, making their practical use impossible. In our research we attempt to solve this problem with an implementation of a practical spatial-temporal de-noising algorithm, based on image accumulation. Image matching and spatial-temporal filtering was performed in Bayer RAW data space, which allowed us to benefit from predictable sensor noise characteristics, thus allowing using a range of algorithmic optimizations. The proposed algorithm accurately compensates for global and local motion and efficiently removes different kinds of noise in noisy images taken in low light conditions. In our algorithm we were able to perform global and local motion compensation in Bayer RAW data space, while preserving the resolution and effectively improving signal to noise ratios of moving objects as well as non-stationary background. The proposed algorithm is suitable for implementation in commercial grade FPGA's and capable of processing 16MP images at capturing rate (10 frames per second). The main challenge for matching between still images is the compromise between the quality of the motion prediction and the complexity of the algorithm and required memory bandwidth. Still images taken in a burst sequence must be aligned to compensate for background motion and foreground objects movements in a scene. High resolution still images coupled with significant time between successive frames can produce large displacements between images, which creates additional difficulty for image matching algorithms. In photo applications it is very important that the noise is efficiently removed in both static, and non-static background as well as in a moving objects, maintaining the resolution of the image. In our proposed

  9. Diet, microhabitat use, and thermal preferences of Ptychoglossus bicolor (Squamata: Gymnophthalmidae in an organic coffee shade plantation in Colombia

    Directory of Open Access Journals (Sweden)

    Jaime M. Anaya-Rojas

    2010-01-01

    Full Text Available Ptychoglossus bicolor is a small gymnophthalmid lizard distributed in the Magdalena Valley of Colombia. We studied ecological features of diet, microhabitat use, and thermal preferences of a population found in an organic coffee shade plantation at the Cordillera Oriental of the Colombian Andes. The studied population had a diet composed predominantly of isopods. The Relative Importance Index of isopods was 98.8%; there were no significant monthly differences in the full stomach content and volume of isopods eaten during the sampling year, neither between rainy and dry seasons. A large number of lizards were found active in the leaf-litter, buried around coffee tree roots, and under or in rotting logs. Lizard body temperature was positively correlated with substrate temperature and air temperature; sex differences in body temperature were not significant. At the studied locality we did not find lizards out of the coffee fields. Our results suggested that these lizards successfully cope with the conditions offered by the organic coffee areas as a result of the cultivation system. Thus, this population might be vulnerable to any modification of the habitat that changes microhabitat availability and abundance of isopods.Ptychoglossus bicolor es un pequeño lagarto de la familia Gymnophthalmidae, que habita el valle del Río Magdalena de Colombia. Se estudiaron las características ecológicas de la dieta, uso de microhábitat y preferencias termales de una población que habita una plantación de café orgánico bajo sombra en la Cordillera Oriental colombiana. La dieta en esta población está dominada por isópodos. El Índice Valor de Importancia Relativa fue del 98.8% y no hubo diferencias mensuales significativas en el contenido estomacal y el volumen de isópodos consumidos durante el año, ni tampoco entre las estaciones de lluvia y seca. Un gran número de lagartos fueron encontrados activos entre la hojarasca, enterrados junto a las ra

  10. Decapod assemblages associated with shallow macroalgal communities in the northwestern Alboran Sea: Microhabitat use and temporal variability

    Science.gov (United States)

    Mateo-Ramírez, Á.; Urra, J.; Rueda, J. L.; Marina, P.; García Raso, J. E.

    2018-05-01

    Decapod assemblages associated with algal fronds and the underlying substratum in two different photophilous macroalgal beds dominated by the brown algae Halopteris scoparia were studied in the northwestern Alboran Sea, between July 2007 and April 2008. A total of 35 decapod species were found in the macroalgal beds, most of them inhabiting both strata and with Hippolyte leptocerus, Pilumnus hirtellus, Sirpus zariquieyi, Acanthonyx lunulatus, Athanas nitescens and Achaeus gracilis as the dominant species. Assemblages on algal fronds and sediment displayed significant variations mainly due to differences in the abundance values of some dominant species (e.g. H. leptocerus) and/or the presence of certain species exclusively in one strata (e.g. Pisa nodipes in algal fronds, Atelecyclus rotundatus and Sicyonia carinata on the sediment stratum). Higher abundance, species richness and Shannon-Wiener diversity index values were registered in the sediment stratum, with a higher contribution of adults-large individuals than of juvenile-small individuals. The temporal variability of the studied assemblages showed maximum abundance values in November, when algal development is minimal. This decoupling between temporal patterns of decapod assemblages and macroalgal dynamic could be related to the lifestyles (recruitment events, movements of species between adjacent habitats and microhabitats) and trophic guilds of dominant species, fish predation pressure and the structural complexity of the habitat. A similar trophic structure was observed for both strata, however there was a predominance of grazers in the algae stratum and of predators and scavengers in the sediment stratum. The high diversity and abundance of predator decapods, the relatively balanced distribution of most trophic groups, and the overall high values of species richness and evenness, could indicate a healthy status of at least two of the eleven "Good Environmental Status" indicators (biodiversity and food

  11. Microhabitat amelioration and reduced competition among understorey plants as drivers of facilitation across environmental gradients: towards a unifying framework

    Science.gov (United States)

    Soliveres, Santiago; Eldridge, David J.; Maestre, Fernando T.; Bowker, Matthew A.; Tighe, Matthew; Escudero, Adrián

    2015-01-01

    Studies of facilitative interactions as drivers of plant richness along environmental gradients often assume the existence of an overarching stress gradient equally affecting the performance of all the species in a given community. However, co-existing species differ in their ecophysiological adaptations, and do not experience the same stress level under particular environmental conditions. Moreover, these studies assume a unimodal richness-biomass curve, which is not as general as previously thought. We ignored these assumptions to assess changes in plant-plant interactions, and their effect on local species richness, across environmental gradients in semi-arid areas of Spain and Australia. We aimed to understand the relative importance of direct (microhabitat amelioration) and indirect (changes in the competitive relationships among the understorey species: niche segregation, competitive exclusion or intransitivity) mechanisms that might underlie the effects of nurse plants on local species richness. By jointly studying these direct and indirect mechanisms using a unifying framework, we were able to see how our nurse plants (trees, shrubs and tussock grasses) not only increased local richness by expanding the niche of neighbouring species, but also by increasing niche segregation among them, though the latter was not important in all cases. The outcome of the competition-facilitation continuum changed depending on the study area, likely because the different types of stress gradient considered. When driven by both rainfall and temperature, or rainfall alone, the community-wide importance of nurse plants remained constant (Spanish sites), or showed a unimodal relationship along the gradient (Australian sites). This study expands our understanding of the relative roles of plant-plant interactions and environmental conditions as drivers of local species richness in semi-arid environments. These results can also be used to refine predictions about the response of

  12. Microhabitat amelioration and reduced competition among understorey plants as drivers of facilitation across environmental gradients: towards a unifying framework.

    Science.gov (United States)

    Soliveres, Santiago; Eldridge, David J; Maestre, Fernando T; Bowker, Matthew A; Tighe, Matthew; Escudero, Adrián

    2011-11-20

    Studies of facilitative interactions as drivers of plant richness along environmental gradients often assume the existence of an overarching stress gradient equally affecting the performance of all the species in a given community. However, co-existing species differ in their ecophysiological adaptations, and do not experience the same stress level under particular environmental conditions. Moreover, these studies assume a unimodal richness-biomass curve, which is not as general as previously thought. We ignored these assumptions to assess changes in plant-plant interactions, and their effect on local species richness, across environmental gradients in semi-arid areas of Spain and Australia. We aimed to understand the relative importance of direct (microhabitat amelioration) and indirect (changes in the competitive relationships among the understorey species: niche segregation, competitive exclusion or intransitivity) mechanisms that might underlie the effects of nurse plants on local species richness. By jointly studying these direct and indirect mechanisms using a unifying framework, we were able to see how our nurse plants (trees, shrubs and tussock grasses) not only increased local richness by expanding the niche of neighbouring species, but also by increasing niche segregation among them, though the latter was not important in all cases. The outcome of the competition-facilitation continuum changed depending on the study area, likely because the different types of stress gradient considered. When driven by both rainfall and temperature, or rainfall alone, the community-wide importance of nurse plants remained constant (Spanish sites), or showed a unimodal relationship along the gradient (Australian sites). This study expands our understanding of the relative roles of plant-plant interactions and environmental conditions as drivers of local species richness in semi-arid environments. These results can also be used to refine predictions about the response of

  13. Diet and gut microbiota of two supralittoral amphipods Orchestia montagui and Talitrus saltator living in different microhabitats

    Science.gov (United States)

    Abdelrhman, Khaled F. A.; Bacci, Giovanni; Nistri, Annamaria; Mengoni, Alessio; Ugolini, Alberto

    2017-10-01

    Talitrus saltator (Montagu) and Orchestia montagui Audouin live in different microhabitats of the same supralittoral belt. T. saltator can be found in the damp sand of beaches with scarce or absent wracked material near the water line. O. montagui is frequently found in the Posidonia banquettes or under wracked material, often in contact with the substrate. This study investigates the effect of diet on species-specific gut microbiota patterns in these talitrid species. Adults were collected and fed with artificial food (commercial fish food and pieces of blotting paper) for 51 days. Gut microbiota were analyzed at five time intervals (0 h, 24 h, 7, 23 and 51 days) by 16S rRNA gene metagenomic analysis and by estimating the relative abundance of cellulases (glycosyl hydrolase gene family 48, GHF48) gene copies. The gut microbiota of O. montagui was more affected than that of T. saltator by diet shift. Although the taxonomic profile of the gut microbiota varied with time in both species, with an increase of Protobacteria in O. montagui and of Actinobacteria and Bacteroidetes in T. saltator, genes involved in cellulose degradation (GHF48 family) showed a large-scale increase in O. montagui but not in T. saltator. We conclude that the diet variation has different influence on the composition of gut microbiota in the two talitrid species in accordance with their different alimentary habits: the more generalist T. saltator (detritivore, grazer, and scavenger) showed less changes in its gut microbiota composition than the more specialist O. montagui (detritivore and grazer), which strongly modified its gut microbiota composition by the captivity diet.

  14. Molluscs associated with the macroalgae of the genus Gracilaria (Rhodophyta): importance of algal fronds as microhabitat in a hypersaline mangrove in Northeastern Brazil.

    Science.gov (United States)

    Queiroz, R N M; Dias, T L P

    2014-08-01

    The fronds of marine macroalgae play an important role in coastal ecosystems because the algae banks are utilized as a microhabitat by different taxa, including molluscs, one of the most abundant and diverse animals of marine ecosystems. In this study, we characterized the malacofauna associated with the macroalgae Gracilaria domingensis (Kützing) Sonder ex Dickie 1874 and Gracilaria cuneata Areschoug 1854 of a hypersaline mangrove on the northern coast of the state of Rio Grande do Norte, Northeastern Brazil. The first alga dominates in the rainy season and it is substituted by second one in the dry period. A total of 1,490 molluscs were surveyed, representing 56 species in 29 families: 1,081 were associated with G. domingensis and 409 with G. cuneata, the latter showing the greater diversity (H'=1.25). Columbellidae, Neritidae, Pyramidellidae and Cerithiidae were among the most representative families in the number of species and individuals. The micromolluscs were dominant in the algal microhabitat, constituting 74.63% of the malacofauna recorded. The columbellid Parvanachis obesa (C. B. Adams, 1845) was the dominant species followed by the neritid Neritina virginea (Linnaeus, 1758) in both algae. In spite of the annual alternated succession of the algae species, at least 15 mollusc species are common for these algae. Furthermore, juveniles of P. obesa were recorded in both seasons, indicating a continuous reproduction. Possible reasons for difference in abundance, diversity and dominance of molluscs living on these algae are discussed. Both species of substrate-algae represent an important microhabitat for refuge, feeding and the reproduction of small-sized mollusc species during rainy and dry seasons.

  15. Molluscs associated with the macroalgae of the genus Gracilaria (Rhodophyta: importance of algal fronds as microhabitat in a hypersaline mangrove in Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    RNM Queiroz

    Full Text Available The fronds of marine macroalgae play an important role in coastal ecosystems because the algae banks are utilized as a microhabitat by different taxa, including molluscs, one of the most abundant and diverse animals of marine ecosystems. In this study, we characterized the malacofauna associated with the macroalgae Gracilaria domingensis (Kützing Sonder ex Dickie 1874 and Gracilaria cuneata Areschoug 1854 of a hypersaline mangrove on the northern coast of the state of Rio Grande do Norte, Northeastern Brazil. The first alga dominates in the rainy season and it is substituted by second one in the dry period. A total of 1,490 molluscs were surveyed, representing 56 species in 29 families: 1,081 were associated with G. domingensis and 409 with G. cuneata, the latter showing the greater diversity (H′=1.25. Columbellidae, Neritidae, Pyramidellidae and Cerithiidae were among the most representative families in the number of species and individuals. The micromolluscs were dominant in the algal microhabitat, constituting 74.63% of the malacofauna recorded. The columbellid Parvanachis obesa(C. B. Adams, 1845 was the dominant species followed by the neritid Neritina virginea (Linnaeus, 1758 in both algae. In spite of the annual alternated succession of the algae species, at least 15 mollusc species are common for these algae. Furthermore, juveniles of P. obesa were recorded in both seasons, indicating a continuous reproduction. Possible reasons for difference in abundance, diversity and dominance of molluscs living on these algae are discussed. Both species of substrate-algae represent an important microhabitat for refuge, feeding and the reproduction of small-sized mollusc species during rainy and dry seasons.

  16. Efficiency figures and rating methods are essential for the design and implementation of energetically optimized general lighting systems; Neue Effizienzkennzahlen fuer Beleuchtungssysteme in Gebaeuden

    Energy Technology Data Exchange (ETDEWEB)

    Boer, Jan de [Fraunhofer-Institut fuer Bauphysik, Stuttgart (Germany); Aydinli, Sirri [Technische Universitaet Berlin (Germany); Cornelius, Wolfgang [Fachverband Tageslicht und Rauchschutz e.V. (FVLR), Detmold (Germany); Minnerup, Joerg [TRILUX GmbH + Co KG, Arnsberg (Germany); Schornick, Dieter [ZVEI - Zentralverband Elektrotechnik-und Elektronikindustrie e.V., Frankfurt (Germany); Wershoven, Ralf [ERCO Leuchten GmbH, Luedenscheid (Germany); Jakobiak, Roman

    2011-08-15

    Over the last years - on national as well as on international level - integrated rating methods (daylighting as well as artificial lighting) have been developed and transferred into practice, the later was fostered by integration into the corresponding standards (DIN V 18599-4, EN 15193-1) and the methods being referenced by national regulations like the German Building Energy Conservation Ordinance (EnEV). Emerging new lighting technologies und requirements to further improve the rating procedure pushed the development of additional new efficiency figures. The concept of expense factors has long been available and applied e.g. in the domain of heating systems. Now, as derived in this publication, it is as well assigned to indoor lighting systems. Therefore, from now on, it will be possible to differentiate lighting installations by their net energy and by their final energy demand. The efficiency of the lighting system itself can be described as function of the expense factor. Currently several new LED-products (lamps and luminaires) are introduced to the market of general lighting. In order to enable practitioners to energetically rate these products, the diversity of products has been structured into classes with assigned efficiency figures. Lighting appliances strongly depend on how the considered zone is used. To provide practioners with exemplary solutions (type of lighting system, facade composition, lighting control) a collection of typical appliances as function of zone usage has been established. This collection has been matched to the structure of the German DIN V 18599 standards.

  17. Description, microhabitat selection and infection patterns of sealworm larvae (Pseudoterranova decipiens species complex, nematoda: ascaridoidea) in fishes from Patagonia, Argentina

    Science.gov (United States)

    2013-01-01

    . Most of the sealworms were collected encapsulated from the muscles and, to a lesser degree, from the mesenteries and the liver. Conclusions We provided the first molecular identification, morphological description and microhabitat characterization of sealworm larvae from the Argentinean Patagonian coast. We also reported the infection levels of sealworms on 20 fish species in order to elucidate the life cycle of these nematodes in this area. PMID:23988009

  18. Description, microhabitat selection and infection patterns of sealworm larvae (Pseudoterranova decipiens species complex, nematoda: ascaridoidea) in fishes from Patagonia, Argentina.

    Science.gov (United States)

    Hernández-Orts, Jesús S; Aznar, Francisco J; Blasco-Costa, Isabel; García, Néstor A; Víllora-Montero, María; Crespo, Enrique A; Raga, Juan A; Montero, Francisco E

    2013-08-29

    collected encapsulated from the muscles and, to a lesser degree, from the mesenteries and the liver. We provided the first molecular identification, morphological description and microhabitat characterization of sealworm larvae from the Argentinean Patagonian coast. We also reported the infection levels of sealworms on 20 fish species in order to elucidate the life cycle of these nematodes in this area.

  19. Consequences of least tern (Sternula antillarum) microhabitat nest-site selection on natural and mechanically constructed sandbars in the Missouri River

    Science.gov (United States)

    Stucker, Jennifer H.; Buhl, Deborah A.; Sherfy, Mark H.

    2013-01-01

    Nest-habitat selection in colonial species has rarely been assessed at multiple spatial scales to evaluate its fitness consequences. Management for the federally endangered U.S. Interior population of Least Terns (Sternula antillarum) has focused on maintenance of breeding habitats, including mechanical construction of sandbars from dredged material. Least Terns are attracted to large areas of unvegetated substrate, yet small-scale habitat features are thought to trigger selection for nesting. We evaluated nest-scale habitat selection to determine (1) whether selection differs between constructed and natural sandbars and (2) the subsequent consequences of habitat selection on nest success. During 2006–2008, we examined 869 Least Tern nest sites on constructed and natural sandbars in the Missouri River for evidence of microhabitat selection at the nest in relation to habitat within the surrounding 3-m area. Least Tern nest sites had coarser and larger substrate materials at the nest, more debris, and less vegetation than the surrounding area. Nests in constructed habitats had a greater percentage of coarse substrates and less vegetation or debris than nests in naturally created habitats. Apparent nest success was 1.8× greater on constructed than on natural sandbars. Nest success was best predicted by models with two spatial scales of predictors, including substrates (nest) and vegetation and debris (nest or surrounding area). Our results indicate that Least Terns select nest microhabitat characteristics that are associated with wind- and water-scoured habitats, and that nest success increases when these habitats are selected.

  20. DIET OF DENDROPSOPHUS MICROCEPHALUS AND SCARTHYLA VIGILANS (ANURA: HYLIDAE AT A LOCALITY IN NORTH-WESTERN VENEZUELA WITH NOTES ON MICROHABITAT OCCUPATION

    Directory of Open Access Journals (Sweden)

    KIMBERLYN A. FONSECA-PÉREZ

    Full Text Available ABSTRACT The coexistence of species with similar ecological requirements (food, space, time has typically drawn attention of researchers because competition for resources is expected to be high. The diet and microhabitat occupation of two morphologically and ecologically similar species of Hylidae (Anura, Dendropsophus microcephalus and Scarthyla vigilans, were analyzed at a locality in north-western Venezuela, with the aim of addressing the potential for space and food competition between them. Diet was estimated through the analysis of stomach contents and microhabitat occupation was estimated through recordings of perch type, height and horizontal distance to water. Thirty-six prey categories (32 families, 4 orders of arthropods were identified: 30 categories in D. microcephalus and 21 categories in S. vigilans. The most important prey (RII in D. microcephalus were Agelenidae (11.1%, Tachinidae (9.32% and Lepidoptera-larvae (7.96%. Gryllidae (14.13%, Cicadidae (9.1%, Cicadellidae (8.3% and Delphacidae (8.02% were the most important in S. vigilans. Diet overlap was relatively low (0.32. Both species have relatively generalist diets. Both species occupied the same type of perches (leaves and stems of Dicotyledons and Monocotyledons and heights (average: S. vigilans, 24 ± 16.2 cm; D. microcephalus, 22.7 ± 9.5 cm. The potential for space competition is high if perches are limited and food competition is expected to be low.

  1. Optimizing Low Light Level Imaging Techniques and Sensor Design Parameters using CCD Digital Cameras for Potential NASA Earth Science Research aboard a Small Satellite or ISS

    Data.gov (United States)

    National Aeronautics and Space Administration — For this project, the potential of using state-of-the-art aerial digital framing cameras that have time delayed integration (TDI) to acquire useful low light level...

  2. Prototype of a new tip developed to be coupled to dental light-curing units for optimizing bonding of orthodontic brackets and accessories

    Directory of Open Access Journals (Sweden)

    Sergio Luiz Mota Júnior

    2013-12-01

    Full Text Available OBJECTIVE: development of a new device to be coupled to light-curing units for bonding orthodontic brackets and accessories, and test its efficacy in an in vitro mechanical trial. The inner surface of the device is mirrored and is based on physical concepts of light refraction and reflection. The main advantage of such device is the reduced clinical time needed for bonding and the low possibility of contamination during the process. METHODS: One hundred and twenty specimens were used for testing the shear bond strength of brackets bonded with the device. The Adhesive Remnant Index (ARI was also determined. The sample was divided into 2 groups. In group 1 a halogen light-curing unit was used while in group 2 a led light-curing unit was used. Each group was then subdivided. In subgroups H1 and L1, a conventional light guide rod was used while in subgroups H2 and L2 bonding was performed with the mirrored device coupled to the tip of the guide light rod. RESULTS: The values obtained for the shear bond strength and the ARI in the subgroups were compared. Results showed that there was no statistically significant difference for the shear strength (p > 0.05 and the ARI (p > 0.05 between the subgroups. CONCLUSION: The tests of mechanical trials and the ARI analysis showed that the new device fulfilled the requirements for bonding orthodontic accessories, and that the time for bonding was reduced to half, being necessary only one light exposure.

  3. Multifunctional. Glass system walls optimize acoustics, lighting and room climate in open offices; Multifunktional. Glas-Systemwaende optimieren Akustik, Beleuchtung und Klima in offenen Buerolandschaften

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, H.V. [Fraunhofer-Institut fuer Bauphysik (IBP), Stuttgart (Germany); Renz, J. [renz solutions GmbH, Aidlingen (Germany)

    2008-05-15

    Acoustics, light and climate are determining factors of thermal comfort in multiple office buildings. Internal structural elements used to take over these ergonomic functions until now; now, all three aspects can be integrated completely and at low cost in new types of glass wall systems. (orig.)

  4. Light Sources and Lighting Circuits

    Science.gov (United States)

    Honda, Hisashi; Suwa, Takumi; Yasuda, Takeo; Ohtani, Yoshihiko; Maehara, Akiyoshi; Okada, Atsunori; Komatsu, Naoki; Mannami, Tomoaki

    means of using filler gas with a higher atomic weight. Regarding fluorescent lamps, studies and developments for longer operating life and improvement in the lumen maintenance factor for the straight-type and circular-type fluorescent lamps were actively pursued. Regarding self-ballasted fluorescent lamps, the main stream of development was aimed at reducing lamp size and increasing energy conservation, and the development of new products that took advantage of these features proceeded. In regard to LED light sources, basic research and product development, including new application development, were vigorously implemented. In basic research, studies were reported, not only on efficacy improvements through optimization of the LED chips, phosphor layers, and packaging technology, but also on photometry, colorimetry, and visual psychology. In the field of application, applications were studied for general lighting sources and also for a wide range of fields, such as automotive headlights and visible light communication. Also, many academic conferences and exhibitions were held domestically and overseas, and the high level of interest suggests high expectations for this next-generation light source. Regarding HID lamps, there was much activity in research and development and in the commercialization of the ceramic metal halide lamp product, and products were commercialized with features such as higher efficiency (130 lm/W) and higher color rendering properties (R9 ≥ 90). In the high-pressure sodium lamps, there were many study reports concerning plant growth and insect pest control using its low insect-attracting characteristics. With high-pressure mercury lamps, there were many reports on reducing lamp size and increasing intensity for use as a light source for projectors.

  5. Fish assemblage of the Mamanguape Environmental Protection Area, NE Brazil: abundance, composition and microhabitat availability along the mangrove-reef gradient

    Directory of Open Access Journals (Sweden)

    Josias Henrique de Amorim Xavier

    Full Text Available Reefs, mangroves and seagrass biotopes often occur in close association, forming a complex and highly productive ecosystem that provide significant ecologic and economic goods and services. Different anthropogenic disturbances are increasingly affecting these tropical coastal habitats leading to growing conservation concern. In this field-based study, we used a visual census technique (belt transects 50 m x 2 m to investigate the interactions between fishes and microhabitats at the Mamanguape Mangrove-Reef system, NE Brazil. Overall, 144 belt transects were performed from October 2007 to September 2008 to assess the structure of the fish assemblage. Fish trophic groups and life stage (juveniles and adults were recorded according to literature, the percent cover of the substrate was estimated using the point contact method. Our results revealed that fish composition gradually changed from the Estuarine to the Reef zone, and that fish assemblage was strongly related to the microhabitat availability, as suggested by the predominance of carnivores at the Estuarine zone and presence of herbivores at the Reef zone. Fish abundance and diversity were higher in the Reef zone and estuary margins, highlighting the importance of structural complexity. A pattern of nursery area utilization, with larger specimens at the Transition and Reef Zone and smaller individuals at the Estuarine zone, was recorded for Abudefduf saxatilis, Anisotremus surinamensis, Lutjanus alexandrei, and Lutjanus jocu. Our findings clearly suggests ecosystem connectivity between mangrove, seagrass and reef biotopes, and highlighted the importance of Mamanguape Mangrove-Reef System as a priority area for conservation and research, whose habitat mosaics should be further studied and protected.

  6. Optimization of CMOS image sensor utilizing variable temporal multisampling partial transfer technique to achieve full-frame high dynamic range with superior low light and stop motion capability

    Science.gov (United States)

    Kabir, Salman; Smith, Craig; Armstrong, Frank; Barnard, Gerrit; Schneider, Alex; Guidash, Michael; Vogelsang, Thomas; Endsley, Jay

    2018-03-01

    Differential binary pixel technology is a threshold-based timing, readout, and image reconstruction method that utilizes the subframe partial charge transfer technique in a standard four-transistor (4T) pixel CMOS image sensor to achieve a high dynamic range video with stop motion. This technology improves low light signal-to-noise ratio (SNR) by up to 21 dB. The method is verified in silicon using a Taiwan Semiconductor Manufacturing Company's 65 nm 1.1 μm pixel technology 1 megapixel test chip array and is compared with a traditional 4 × oversampling technique using full charge transfer to show low light SNR superiority of the presented technology.

  7. Management Optimization of the Luminous Flux Regulation of a Lighting System in Road Tunnels. A First Approach to the Exertion of Predictive Control Systems

    Directory of Open Access Journals (Sweden)

    Ferdinando Salata

    2016-10-01

    Full Text Available Lighting very long road tunnels implies a high consumption of electrical energy since it requires a proper illumination during the whole day. In particular, in the daytime, the illuminance levels right at the tunnel entrance threshold and exit zones must be higher than those characterizing the inside of the tunnel; in this way, the eye of the driver is able to adapt and be safe while passing from a high natural illumination of the outside to the lighting conditions characterizing the inside of the tunnel. However this causes a high energy demand. Therefore, this case study investigates whether it is possible to minimize the energy demand through the exertion of an automatic new control system regulating the luminous fluxes of artificial sources (guaranteeing the parameters set by the regulation with respect to the variation of the natural light characterizing the outside. The innovative control systems must be characterized by high reliability levels in order to guarantee conditions which are not dangerous to the driver if an outage occurs and minimize their maintenance costs. To carry out this type of study, the software DIALux was used to simulate a tunnel with a dimming system (with lamps characterized by a high luminous efficiency regulated by a pre-programmed logic control system (with high Mean Time Between Failure (MTBF values. The savings obtained enabled the amortization of the solution here suggested in a time interval that makes it an advantageous choice economically speaking.

  8. Etching process optimization using NH{sub 4}Cl aqueous solution to texture ZnO:Al films for efficient light trapping in flexible thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, S., E-mail: susanamaria.fernandez@ciemat.es [CIEMAT, Departamento de Energias Renovables, Madrid (Spain); Abril, O. de [ISOM and Departamento de Fisica Aplicada, Escuela Tecnica Superior de Ingenieros de Telecomunicacion, Universidad Politecnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Naranjo, F.B. [Grupo de Ingenieria Fotonica, Universidad de Alcala, Departamento de Electronica, Alcala de Henares, Madrid (Spain); Gandia, J.J. [CIEMAT, Departamento de Energias Renovables, Madrid (Spain)

    2012-04-02

    0.5 {mu}m-thick aluminum-doped zinc oxide (ZnO:Al) films were deposited at 100 Degree-Sign C on polyethylene terephthalate substrates by Radio Frequency magnetron sputtering. The as-deposited films were compact and dense, showing grain sizes of 32.0 {+-} 6.4 nm and resistivities of (8.5 {+-} 0.7) Multiplication-Sign 10{sup -4} {Omega} cm. The average transmittance in the visible wavelength range of the structure ZnO:Al/PET was around 77%. The capability of a novel two-step chemical etching using diluted NH{sub 4}Cl aqueous solution to achieve efficient textured surfaces for light trapping was analyzed. The results indicated that both the aqueous solution and the etching method resulted appropriated to obtain etched surfaces with a surface roughness of 32 {+-} 5 nm, haze factors at 500 nm of 9% and light scattering at angles up to 50 Degree-Sign . To validate all these results, a commercially ITO coated PET substrate was used for comparison.

  9. Development and optimization of a four-rod RFQ accelerator for light ions - construction and testing of a H--injector for HERA

    International Nuclear Information System (INIS)

    Ferch, M.

    1987-01-01

    In the framework of the present thesis the RF properties of a new RFQ accelerator structure were studied and optimized. After a short section about the foundations of the acceleration with RFQ resonators and the description of the most important general structure properties the operation of the λ/2 resonator in the construction developed here is described. For the quantitative description of the RF properties a theoretical model was developed which describes the RF-structure parameters with sufficient accuracy and is furthermore useful in the planning of further RF projects. For the detailed study of the oscillation shape and the field distributions resulting from this especially in the region of the quadrupolarly arranged beam guiding elements special measuring methods were improved respectively newly developed. With the knowledge resulting from this the efficiency as well as the stability of the acceleration and focusing fields could be optimized. The high-power resonator constructed in the framework of this thesis operates at a resonance frequency of 202.56 MHz and is layed out for pulsed operation. Corresponding to this only into the ground rail a cooling loop was integrated. The electrodes are rod-shaped performed. The in the ideal case sinus-shaped modulation profile of the quadrupole electrodes was approximated by a trapezoidal approximation. (orig./HSI) [de

  10. InGaN/GaN multilayer quantum dots yellow-green light-emitting diode with optimized GaN barriers.

    Science.gov (United States)

    Lv, Wenbin; Wang, Lai; Wang, Jiaxing; Hao, Zhibiao; Luo, Yi

    2012-11-07

    InGaN/GaN multilayer quantum dot (QD) structure is a potential type of active regions for yellow-green light-emitting diodes (LEDs). The surface morphologies and crystalline quality of GaN barriers are critical to the uniformity of InGaN QD layers. While GaN barriers were grown in multi-QD layers, we used improved growth parameters by increasing the growth temperature and switching the carrier gas from N2 to H2 in the metal organic vapor phase epitaxy. As a result, a 10-layer InGaN/GaN QD LED is demonstrated successfully. The transmission electron microscopy image shows the uniform multilayer InGaN QDs clearly. As the injection current increases from 5 to 50 mA, the electroluminescence peak wavelength shifts from 574 to 537 nm.

  11. Public lighting.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1986-01-01

    The function of public lighting and the relationship between public lighting and accidents are considered briefly as aspects of effective countermeasures. Research needs and recent developments in installation and operational described. Public lighting is an efficient accident countermeasure, but

  12. Light Pollution

    Science.gov (United States)

    Riegel, Kurt W.

    1973-01-01

    Outdoor lighting is light pollution which handicaps certain astronomical programs. Protective measures must be adopted by the government to aid observational astronomy without sacrificing legitimate outdoor lighting needs. (PS)

  13. Intelligent Lighting Control System

    OpenAIRE

    García, Elena; Rodríguez González, Sara; de Paz Santana, Juan F.; Bajo Pérez, Javier

    2014-01-01

    This paper presents an adaptive architecture that allows centralized control of public lighting and intelligent management, in order to economise on lighting and maintain maximum comfort status of the illuminated areas. To carry out this management, architecture merges various techniques of artificial intelligence (AI) and statistics such as artificial neural networks (ANN), multi-agent systems (MAS), EM algorithm, methods based on ANOVA and a Service Oriented Aproach (SOA). It performs optim...

  14. WOW: light print, light propel, light point

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Bañas, Andrew Rafael; Aabo, Thomas

    2012-01-01

    anywhere in a sample at any orientation using real-time 3D optical micromanipulation with six degrees of freedom. One of the key aspects of our demonstrated WOWs is the change in direction of in-coupled light and the marked increase in numerical aperture of the out-coupled light. Hence, each light...... propelled WOW can tap from a relatively broad incident beam and generate a much more tightly confined light at its tip. The presentation contains both numerical simulations related to the propagation of light through a WOW and preliminary experimental demonstrations on our BioPhotonics Workstation...

  15. Dynamic lighting design

    DEFF Research Database (Denmark)

    Linnebjerg, Sofie

    [Berson et al., 2002] become apparent, that light, beside serving a purpose of enabling visual orientation, also are influencing the internal body clock, affecting sleep-wake cycle, immune responses, appetite, behaviour, mood, alertness and attention - depending on the duration, timing and quality...... of light [Schlangen, 2014]. But, as humans spend more than 90 % of the time inside a build environment [Klepeis et al., 2001] and the daylight intake in our buildings is not always optimal to meet the needs for dynamic light [Hansen et al., 2017], this research project points to the importance...

  16. Flight Test Results of a GPS-Based Pitot-Static Calibration Method Using Output-Error Optimization for a Light Twin-Engine Airplane

    Science.gov (United States)

    Martos, Borja; Kiszely, Paul; Foster, John V.

    2011-01-01

    As part of the NASA Aviation Safety Program (AvSP), a novel pitot-static calibration method was developed to allow rapid in-flight calibration for subscale aircraft while flying within confined test areas. This approach uses Global Positioning System (GPS) technology coupled with modern system identification methods that rapidly computes optimal pressure error models over a range of airspeed with defined confidence bounds. This method has been demonstrated in subscale flight tests and has shown small 2- error bounds with significant reduction in test time compared to other methods. The current research was motivated by the desire to further evaluate and develop this method for full-scale aircraft. A goal of this research was to develop an accurate calibration method that enables reductions in test equipment and flight time, thus reducing costs. The approach involved analysis of data acquisition requirements, development of efficient flight patterns, and analysis of pressure error models based on system identification methods. Flight tests were conducted at The University of Tennessee Space Institute (UTSI) utilizing an instrumented Piper Navajo research aircraft. In addition, the UTSI engineering flight simulator was used to investigate test maneuver requirements and handling qualities issues associated with this technique. This paper provides a summary of piloted simulation and flight test results that illustrates the performance and capabilities of the NASA calibration method. Discussion of maneuver requirements and data analysis methods is included as well as recommendations for piloting technique.

  17. Optimization of synthesis technique and luminescent properties in Eu{sup 3+}-activated NaCaPO{sub 4} phosphor for solid state lighting applications

    Energy Technology Data Exchange (ETDEWEB)

    Ratnam, B.V. [Department of Physics, Changwon National University, Changwon 51140 (Korea, Republic of); Sahu, Mukesh K.; Vishwakarma, Amit K.; Jha, Kaushal [Luminescent Materials Research Lab (LMRL), Department of Applied Physics, Delhi Technological University, Delhi 110042 (India); Woo, Hyun-Joo [Department of Physics, Changwon National University, Changwon 51140 (Korea, Republic of); Jang, Kiwan, E-mail: kwjang@changwon.ac.kr [Department of Physics, Changwon National University, Changwon 51140 (Korea, Republic of); Jayasimhadri, M., E-mail: jayaphysics@yahoo.com [Luminescent Materials Research Lab (LMRL), Department of Applied Physics, Delhi Technological University, Delhi 110042 (India)

    2017-05-15

    Europium activated NaCaPO{sub 4} phosphor has been synthesized by various synthesis techniques such as solid-state reaction (SSR), molten salt synthesis (MSS) and sol-gel combustion (SGC) method to optimize the synthesis procedure. The comparative investigations of structural and luminescent properties have been studied to know the best synthesis method. The XRD patterns and Rietveld refinement analysis of the synthesized phosphors confirmed the single phase orthorhombic structure of NaCaPO{sub 4}. Excitation spectra indicate the strong absorption in near ultraviolet (n-UV) region and the emission spectra exhibit strong emission band at 595 nm corresponds to {sup 5}D{sub 0}→{sup 7}F{sub 1} transition under n-UV (λ{sub ex}=392 nm) excitation. The SGC route synthesized phosphor exhibit intense emission than that of the SSR and MSS method. Therefore, the effect of dopant (Eu{sup 3+}) concentration on the emission intensity and concentration quenching mechanism has been discussed in detail for the Eu{sup 3+} doped NaCaPO{sub 4} phosphor synthesized by SGC method. The CIE chromaticity coordinates have been calculated for the phosphors synthesized by SSR, MSS and SGC methods to reveal the emitting color and also to know the utility of this phosphor for white LEDs.

  18. Optimizing countershading camouflage.

    Science.gov (United States)

    Cuthill, Innes C; Sanghera, N Simon; Penacchio, Olivier; Lovell, Paul George; Ruxton, Graeme D; Harris, Julie M

    2016-11-15

    Countershading, the widespread tendency of animals to be darker on the side that receives strongest illumination, has classically been explained as an adaptation for camouflage: obliterating cues to 3D shape and enhancing background matching. However, there have only been two quantitative tests of whether the patterns observed in different species match the optimal shading to obliterate 3D cues, and no tests of whether optimal countershading actually improves concealment or survival. We use a mathematical model of the light field to predict the optimal countershading for concealment that is specific to the light environment and then test this prediction with correspondingly patterned model "caterpillars" exposed to avian predation in the field. We show that the optimal countershading is strongly illumination-dependent. A relatively sharp transition in surface patterning from dark to light is only optimal under direct solar illumination; if there is diffuse illumination from cloudy skies or shade, the pattern provides no advantage over homogeneous background-matching coloration. Conversely, a smoother gradation between dark and light is optimal under cloudy skies or shade. The demonstration of these illumination-dependent effects of different countershading patterns on predation risk strongly supports the comparative evidence showing that the type of countershading varies with light environment.

  19. Light contamination

    International Nuclear Information System (INIS)

    Cepeda Pena, William Enrique

    1998-01-01

    The article tries on the wrong use of the artificial light, of the main problems of the light contamination, dispersion of the light, noxious effects of the light contamination, ecological effects, effects on the man's biological rhythm, economic effects and effects about the civic and vial security, among other topics

  20. Studies and optimization of Pohang Light Source-II superconducting radio frequency system at stable top-up operation with beam current of 400 mA

    International Nuclear Information System (INIS)

    Joo, Youngdo; Yu, Inha; Park, Insoo; Chun, Myunghwan; Lee, Byung-Joon; Hwang, Ilmoon; Ha, Taekyun; Shin, Seunghwan; Sohn, Younguk

    2014-01-01

    After three years of upgrading work, the Pohang Light Source-II (PLS-II) is now successfully operating. The final quantitative goal of PLS-II is a top-up user-service operation with beam current of 400 mA to be completed by the end of 2014. During the beam store test up to 400 mA in the storage ring (SR), it was observed that the vacuum pressure around the radio frequency (RF) window of the superconducting cavity rapidly increases over the interlock level limiting the availability of the maximum beam current storing. Although available beam current is enhanced by setting a higher RF accelerating voltage, it is better to keep the RF accelerating voltage as low as possible in the long time top-up operation. We investigated the cause of the window vacuum pressure increment by studying the changes in the electric field distribution at the superconducting cavity and waveguide according to the beam current. In our simulation, an equivalent physical modeling was developed using a finite-difference time-domain code. The simulation revealed that the electric field amplitude at the RF window is exponentially increased as the beam current increases, thus this high electric field amplitude causes a RF breakdown at the RF window, which comes with the rapid increase of window vacuum pressure. The RF accelerating voltage of PLS-II RF system was set to 4.95 MV, which was estimated using the maximum available beam current that works as a function of RF voltage, and the top-up operation test with the beam current of 400 mA was successfully carried out

  1. Sonophotocatalytic degradation of trypan blue and vesuvine dyes in the presence of blue light active photocatalyst of Ag3PO4/Bi2S3-HKUST-1-MOF: Central composite optimization and synergistic effect study.

    Science.gov (United States)

    Mosleh, S; Rahimi, M R; Ghaedi, M; Dashtian, K

    2016-09-01

    An efficient simultaneous sonophotocatalytic degradation of trypan blue (TB) and vesuvine (VS) using Ag3PO4/Bi2S3-HKUST-1-MOF as a novel visible light active photocatalyst was carried out successfully in a continuous flow-loop reactor equipped to blue LED light. Ag3PO4/Bi2S3-HKUST-1-MOF with activation ability under blue light illumination was synthesized and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), photoluminescence (PL) and diffuse reflectance spectra (DRS). The effect of operational parameters such as the initial TB and VS concentration (5-45mg/L), flow rate (30-110mL/min), irradiation and sonication time (10-30min), pH (3-11) and photocatalyst dosage (0.15-0.35g/L) has been investigated and optimized using central composite design (CCD) combined with desirability function (DF). Maximum sonophotodegradation percentage (98.44% and 99.36% for TB and VS, respectively) was found at optimum condition set as: 25mg/L of each dye, 70mL/min of solution flow rate, 25min of irradiation and sonication time, pH 6 and 0.25g/L of photocatalyst dosage. At optimum conditions, synergistic index value was obtained 2.53 that indicated the hybrid systems including ultrasound irradiation and photocatalysis have higher efficiency compared with sum of the individual processes. Copyright © 2016. Published by Elsevier B.V.

  2. Influence of Time since Fire and Micro-Habitat Availability on Terricolous Lichen Communities in Black Spruce (Picea mariana Boreal Forests

    Directory of Open Access Journals (Sweden)

    Saliha Zouaoui

    2014-11-01

    Full Text Available Terricolous lichens are an important component of boreal forest ecosystems, both in terms of function and diversity. In this study, we examined the relative contribution of microhabitat characteristics and time elapsed since the last fire in shaping terricolous lichen assemblages in boreal forests that are frequently affected by severe stand-replacing fires. We sampled 12 stands distributed across five age classes (from 43 to >200 years. In each stand, species cover (% of all terricolous lichen species and species richness were evaluated within 30 microplots of 1 m2. Our results show that time elapsed since the last fire was the factor that contributed the most to explaining terricolous lichen abundance and species composition, and that lichen cover showed a quadratic relationship with stand age. Habitat variables such as soil characteristics were also important in explaining lichen richness. These results suggest that the presence of suitable substrates is not sufficient for the conservation of late-successional terricolous lichen communities in this ecosystem, and that they also need relatively long periods of times for species dispersal and establishment.

  3. Optimization and Optimal Control

    CERN Document Server

    Chinchuluun, Altannar; Enkhbat, Rentsen; Tseveendorj, Ider

    2010-01-01

    During the last four decades there has been a remarkable development in optimization and optimal control. Due to its wide variety of applications, many scientists and researchers have paid attention to fields of optimization and optimal control. A huge number of new theoretical, algorithmic, and computational results have been observed in the last few years. This book gives the latest advances, and due to the rapid development of these fields, there are no other recent publications on the same topics. Key features: Provides a collection of selected contributions giving a state-of-the-art accou

  4. Optimally Stopped Optimization

    Science.gov (United States)

    Vinci, Walter; Lidar, Daniel

    We combine the fields of heuristic optimization and optimal stopping. We propose a strategy for benchmarking randomized optimization algorithms that minimizes the expected total cost for obtaining a good solution with an optimal number of calls to the solver. To do so, rather than letting the objective function alone define a cost to be minimized, we introduce a further cost-per-call of the algorithm. We show that this problem can be formulated using optimal stopping theory. The expected cost is a flexible figure of merit for benchmarking probabilistic solvers that can be computed when the optimal solution is not known, and that avoids the biases and arbitrariness that affect other measures. The optimal stopping formulation of benchmarking directly leads to a real-time, optimal-utilization strategy for probabilistic optimizers with practical impact. We apply our formulation to benchmark the performance of a D-Wave 2X quantum annealer and the HFS solver, a specialized classical heuristic algorithm designed for low tree-width graphs. On a set of frustrated-loop instances with planted solutions defined on up to N = 1098 variables, the D-Wave device is between one to two orders of magnitude faster than the HFS solver.

  5. "Tangible Lights"

    DEFF Research Database (Denmark)

    Sørensen, Tor; Merritt, Timothy; Andersen, Oskar

    2015-01-01

    While there has been much focus on tangible lighting interfaces embedded in physical objects and smartphones as remote control, there has not been sufficient attention on how the expressivity of bodily movement can be used when designing interactions with light. Therefore, we investigate...... interaction with lighting technology beyond the smartphone and physical controllers. We examine the usefulness of the in-air gestural interaction style for lighting control. We bring forward "Tangible Lights", which serves as a novel interface for in-air interaction with lighting, drawing on existing...

  6. Light Robotics

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Palima, Darwin

    Light Robotics - Structure-Mediated Nanobiophotonics covers the latest means of sculpting of both light and matter for achieving bioprobing and manipulation at the smallest scales. The synergy between photonics, nanotechnology and biotechnology spans the rapidly growing field of nanobiophotonics...

  7. Surgical lighting

    NARCIS (Netherlands)

    Knulst, A.J.

    2017-01-01

    The surgical light is an important tool for surgeons to create and maintain good visibility on the surgical task. Chapter 1 gives background to the field of (surgical) lighting and related terminology. Although the surgical light has been developed strongly since its introduction a long time ago,

  8. Twisted light

    CSIR Research Space (South Africa)

    Forbes, A

    2010-12-01

    Full Text Available Research at the Mathematical Optics Group uses "twisted" light to study new quatum-based information security systems. In order to understand the structure of "twisted" light, it is useful to start with an ordinary light beam with zero twist, namely...

  9. Sustainable indoor lighting

    CERN Document Server

    Mercatelli, Luca; Farini, Alessandro

    2015-01-01

    Encompassing a thorough survey of the lighting techniques applied to internal illumination characterized by high efficiency, optimized color and architectural integration, a consolidated summary of the latest scientific, technical and architectural research is presented in order to give the reader an overview of the different themes with their interactions and mutual effects.   This book describes light principles, methodologies and realisations for indoor illumination at low consumption. Power efficiency, color characteristics and architectural aspects are analyzed in terms of their  practical application, with the interactions between scientific, technological and architectural features considered in order to supply a complete overview, which can be read both at technical level and at user level. Introducing photometric and radiometric quantities and laws, the book first discusses tests and measurements assessing lighting and color characteristics before examining in detail artificial light sources with p...

  10. Adaptive Lighting

    DEFF Research Database (Denmark)

    Petersen, Kjell Yngve; Søndergaard, Karin; Kongshaug, Jesper

    2015-01-01

    the investigations of lighting scenarios carried out in two test installations: White Cube and White Box. The test installations are discussed as large-scale experiential instruments. In these test installations we examine what could potentially occur when light using LED technology is integrated and distributed......Adaptive Lighting Adaptive lighting is based on a partial automation of the possibilities to adjust the colour tone and brightness levels of light in order to adapt to people’s needs and desires. IT support is key to the technical developments that afford adaptive control systems. The possibilities...... differently into an architectural body. We also examine what might occur when light is dynamic and able to change colour, intensity and direction, and when it is adaptive and can be brought into interaction with its surroundings. In short, what happens to an architectural space when artificial lighting ceases...

  11. Sphagnum mosses as a microhabitat for invertebrates in acidified lakes and the colour adaptation and substrate preference in Leucorrhinia dubia (Odonata, Anisoptera)

    Energy Technology Data Exchange (ETDEWEB)

    Henrikson, B.-I. (Dept. of Zoology, Sect. of Animal Ecology, Univ. of Goeteborg, Goeteborg (Sweden))

    1993-01-01

    The increase of peat mosses, Sphagnum spp., in acidified lakes leads to a changed microhabitat structure for benthic invertebrates. The importance of this change was investigated for some benthic invertebrates. Comparisons between quantitative samples of Sphagnum and debris within the acidified Lake Stora Haestevatten, in the Lake Gaardsjoen catchment of SW Sweden, showed significantly higher abundances of Chironomidae, Ceratopogonidae, Odonata, Trichoptera, Cladocera and Argyroneta aquatica (Araneae) in Sphagnum. For chironomidae and Cladocera the differences were tenfold. Special reference was made to the libellulid Leucorrhinia dubia which is common in acid lakes. In a laboratory test, late instar larvae of L. dubia were shown to change colour to correspond to the brown and green colour of Sphagnum. This result was completed with a field test where larvae of L. dubia were significantly more common in Sphagnum of the same colour as the larvae. The ability to change colour may have an adaptive value when coexisting with visual predators. Small larvae were more prevalent in Sphagnum and they also showed a preference for this substrate in the laboratory test. Laboratory tests showed mediumsized larvae preferred Sphagnum. Larvae of L. dubia were more successful as predators on Asellus aquaticus in Sphagnum substrate than in debris in the laboratory test. Laboratory predation tests with notonecta glauca, Corixa dentipes, Acilius sulcatus, Hyphydrus ovatus and L. dubia showed that they could all feed on larvae of L. dubia. The complex habitat structure of Sphagnum is probably the reason for the high abundance of invertebrates since it may serve as both shelter against predation and as foraging sites. it is probably important as a key habitat for young instars of, for example, L. dubia. In lakes with large Sphagnum mats, L. dubia can coexist with fish. The expansion of Sphagnum due to acidification will probably benefit many acid-tolerant invertebrate species. (au)

  12. Natural light illumination system.

    Science.gov (United States)

    Whang, Allen Jong-Woei; Chen, Yi-Yung; Yang, Shu-Hua; Pan, Po-Hsuan; Chou, Kao-Hsu; Lee, Yu-Chi; Lee, Zong-Yi; Chen, Chi-An; Chen, Cheng-Nan

    2010-12-10

    In recent years, green energy has undergone a lot of development and has been the subject of many applications. Many research studies have focused on illumination with sunlight as a means of saving energy and creating healthy lighting. Natural light illumination systems have collecting, transmitting, and lighting elements. Today, most daylight collectors use dynamic concentrators; these include Sun tracking systems. However, this design is too expensive to be cost effective. To create a low-cost collector that can be easily installed on a large building, we have designed a static concentrator, which is prismatic and cascadable, to collect sunlight for indoor illumination. The transmission component uses a large number of optical fibers. Because optical fibers are expensive, this means that most of the cost for the system will be related to transmission. In this paper, we also use a prismatic structure to design an optical coupler for coupling n to 1. With the n-to-1 coupler, the number of optical fibers necessary can be greatly reduced. Although this new natural light illumination system can effectively guide collected sunlight and send it to the basement or to other indoor places for healthy lighting, previously there has been no way to manage the collected sunlight when lighting was not desired. To solve this problem, we have designed an optical switch and a beam splitter to control and separate the transmitted light. When replacing traditional sources, the lighting should have similar characteristics, such as intensity distribution and geometric parameters, to those of traditional artificial sources. We have designed, simulated, and optimized an illumination lightpipe with a dot pattern to redistribute the collected sunlight from the natural light illumination system such that it equals the qualities of a traditional lighting system. We also provide an active lighting module that provides lighting from the natural light illumination system or LED auxiliary

  13. Lighting. Eclairage

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

    Increasing energy costs have led to a review of the high costs of lighting. The use of new energy-efficient lighting equipment, coupled with the use of the proper quantity and quality of lighting only where it is needed, creates a potential for cost reduction. A manual is provided to aid the process of adapting Canadian industrial, commercial, and institutional enterprises to these higher costs. An introductory review of lighting fundamentals is presented, providing a basic understanding of concepts such as illumination, light output measurements, power requirements, lighting quality, and energy audit methods. The currently available lighting equipment used to achieve cost savings is then reviewed, including energy saving lamps and ballasts, controls, and automatic energy control systems. A number of energy management opportunities are identified, such as modification of lighting usage patterns, calculation of the optimum number of lighting fixtures, replacement of existing lamps, and the application of task lighting. Examples are included to show the cost savings possible when applying some of the techniques suggested. 27 figs., 11 tabs.

  14. Nordic Lighting?

    DEFF Research Database (Denmark)

    Munch, Anders V.

    2018-01-01

    The Danish designer Poul Henningsen wrote very elaborated theories of interior lighting from the mid-1920s on. He fought against the cold and reduced light quality of electric bulbs and tried to tame and cultivate this technology by design. He wanted a more rich light for domestic purpose...... worthwhile discussing than other design categories to interpret, whether experience of nature and climatic conditions play a role in Scandinavian Design, as repeatedly stated. This discussion contributes both to understanding of interior lighting and the historiographical critique of Scandinavian Design...... and shaped it through lamp design, colour reflections and differentiated use of several lamps in the room to make a more dim lighting, but with greater variation and softer contrasts. It was a ‘culture’ of lighting, he promoted, but he didn’t saw it as linked to the Nordic countries. His sensibility...

  15. Adaptive Lighting

    DEFF Research Database (Denmark)

    Petersen, Kjell Yngve; Søndergaard, Karin; Kongshaug, Jesper

    2015-01-01

    Adaptive Lighting Adaptive lighting is based on a partial automation of the possibilities to adjust the colour tone and brightness levels of light in order to adapt to people’s needs and desires. IT support is key to the technical developments that afford adaptive control systems. The possibilities...... offered by adaptive lighting control are created by the ways that the system components, the network and data flow can be coordinated through software so that the dynamic variations are controlled in ways that meaningfully adapt according to people’s situations and design intentions. This book discusses...... differently into an architectural body. We also examine what might occur when light is dynamic and able to change colour, intensity and direction, and when it is adaptive and can be brought into interaction with its surroundings. In short, what happens to an architectural space when artificial lighting ceases...

  16. WOW: light print, light propel, light point

    Science.gov (United States)

    Glückstad, Jesper; Bañas, Andrew; Aabo, Thomas; Palima, Darwin

    2012-10-01

    We are presenting so-called Wave-guided Optical Waveguides (WOWs) fabricated by two-photon polymerization and capable of being optically manipulated into any arbitrary orientation. By integrating optical waveguides into the structures we have created freestanding waveguides which can be positioned anywhere in a sample at any orientation using real-time 3D optical micromanipulation with six degrees of freedom. One of the key aspects of our demonstrated WOWs is the change in direction of in-coupled light and the marked increase in numerical aperture of the out-coupled light. Hence, each light propelled WOW can tap from a relatively broad incident beam and generate a much more tightly confined light at its tip. The presentation contains both numerical simulations related to the propagation of light through a WOW and preliminary experimental demonstrations on our BioPhotonics Workstation. In a broader context, this research shows that optically trapped micro-fabricated structures can potentially help bridge the diffraction barrier. This structure-mediated paradigm may be carried forward to open new possibilities for exploiting beams from far-field optics down to the sub-wavelength domain.

  17. Adaptive Lighting

    DEFF Research Database (Denmark)

    Petersen, Kjell Yngve; Kongshaug, Jesper; Søndergaard, Karin

    2015-01-01

    offered by adaptive lighting control are created by the ways that the system components, the network and data flow can be coordinated through software so that the dynamic variations are controlled in ways that meaningfully adapt according to people’s situations and design intentions. This book discusses...... to be static, and no longer acts as a kind of spatial constancy maintaining stability and order? Moreover, what new potentials open in lighting design? This book is one of four books that is published in connection with the research project entitled LED Lighting; Interdisciplinary LED Lighting Research...

  18. Lighting Automation - Flying an Earthlike Habit Project

    Science.gov (United States)

    Falker, Jay; Howard, Ricky; Culbert, Christopher; Clark, Toni Anne; Kolomenski, Andrei

    2017-01-01

    Our proposal will enable the development of automated spacecraft habitats for long duration missions. Majority of spacecraft lighting systems employ lamps or zone specific switches and dimmers. Automation is not in the "picture". If we are to build long duration environments, which provide earth-like habitats, minimize crew time, and optimize spacecraft power reserves, innovation in lighting automation is a must. To transform how spacecraft lighting environments are automated, we will provide performance data on a standard lighting communication protocol. We will investigate utilization and application of an industry accepted lighting control protocol, DMX512. We will demonstrate how lighting automation can conserve power, assist with lighting countermeasures, and utilize spatial body tracking. By using DMX512 we will prove the "wheel" does not need to be reinvented in terms of smart lighting and future spacecraft can use a standard lighting protocol to produce an effective, optimized and potentially earthlike habitat.

  19. Lightness functions

    DEFF Research Database (Denmark)

    Campi, Stefano; Gardner, Richard; Gronchi, Paolo

    2012-01-01

    Variants of the brightness function of a convex body K in n-dimensional Euclidean are investigated. The Lambertian lightness function L(K; v , w ) gives the total reflected light resulting from illumination by a light source at infinity in the direction w that is visible when looking...... in the direction v . The partial brightness function R( K ; v , w ) gives the area of the projection orthogonal to v of the portion of the surface of K that is both illuminated by a light source from the direction w and visible when looking in the direction v . A class of functions called lightness functions...... is introduced that includes L(K;.) and R(K;.) as special cases. Much of the theory of the brightness function like uniqueness, stability, and the existence and properties of convex bodies of maximal and minimal volume with finitely many function values equal to those of a given convex body, is extended...

  20. Light sources and light pollution

    International Nuclear Information System (INIS)

    Pichler, G.

    2005-01-01

    From the dawn of mankind fire and light sources in general played an essential role in everyday life and protection over night. The development of new light sources went through many stages and is now an immense technological achievement, but also a threat for the wildlife at night, mainly because of the so-called light pollution. This paper discusses several very successful light sources connected with low pressure mercury and sodium vapour electric discharges. The luminous efficacy, colour rendering index and other lighting features cannot be always satisfactory, but at least some of the features can be much better than those met by the standard tungsten filament bulbs. High-pressure metal-vapour discharge lamps definitely have a good colour rendering index and a relatively high luminosity. Different light sources with burners at high pressure are discussed, paying special attention to their spectrum. The paper investigates new trends in development through a number of examples with non-toxic elements and pulsed electric discharge, which may be good news in terms of clean environment and energy savings. Light emitting diodes have recently appeared as worthy competitors to conventional light sources. White LEDs have approached 100 lumen/Watt efficacy in laboratories. This suggests that in some not very distant future they could completely replace high-pressure lamps, at least in indoor lighting. The article speculates on new developments which combine trends in nano technology and material science. The paper concludes with light pollution in view of several recent observations of plant and animal life at night in the vicinity of strong light sources. Photo-induced changes at the cell level may completely alter the normal life of plants and animals.(author)

  1. Flashing light in microalgae biotechnology.

    Science.gov (United States)

    Abu-Ghosh, Said; Fixler, Dror; Dubinsky, Zvy; Iluz, David

    2016-03-01

    Flashing light can enhance photosynthesis and improve the quality and quantity of microalgal biomass, as it can increase the products of interest by magnitudes. Therefore, the integration of flashing light effect into microalgal cultivation systems should be considered. However, microalgae require a balanced mix of the light/dark cycle for higher growth rates, and respond to light intensity differently according to the pigments acquired or lost during the growth. This review highlights recently published results on flashing light effect on microalgae and its applications in biotechnology, as well as the recently developed bioreactors designed to fulfill this effect. It also discusses how this knowledge can be applied in selecting the optimal light frequencies and intensities with specific technical properties for increasing biomass production and/or the yield of the chemicals of interest by microalgae belonging to different genera. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Circadian light

    Directory of Open Access Journals (Sweden)

    Bierman Andrew

    2010-02-01

    Full Text Available Abstract The present paper reflects a work in progress toward a definition of circadian light, one that should be informed by the thoughtful, century-old evolution of our present definition of light as a stimulus for the human visual system. This work in progress is based upon the functional relationship between optical radiation and its effects on nocturnal melatonin suppression, in large part because the basic data are available in the literature. Discussed here are the fundamental differences between responses by the visual and circadian systems to optical radiation. Brief reviews of photometry, colorimetry, and brightness perception are presented as a foundation for the discussion of circadian light. Finally, circadian light (CLA and circadian stimulus (CS calculation procedures based on a published mathematical model of human circadian phototransduction are presented with an example.

  3. Bili lights

    Science.gov (United States)

    ... 3 things: Gestational age Bilirubin level in the blood Newborn's age (in hours) In severe cases of increased bilirubin, an exchange transfusion may be done instead. Alternative Names Phototherapy for jaundice; Bilirubin - bili lights; Neonatal ...

  4. Controlling Light Harvesting with Light

    NARCIS (Netherlands)

    Gwizdala, M.S.; Berera, R.; Kirilovsky, D.; van Grondelle, R.; Kruger, T.P.J.

    2016-01-01

    When exposed to intense sunlight, all organisms performing oxygenic photosynthesis implement various photoprotective strategies to prevent potentially lethal photodamage. The rapidly responding photoprotective mechanisms, occurring in the light-harvesting pigment-protein antennae, take effect within

  5. Synchrotron light

    International Nuclear Information System (INIS)

    2001-01-01

    'Synchrotron Light' is an interactive and detailed introduction to the physics and technology of the generation of coherent radiation from accelerators as well as to its widespread high-tech applications in science, medicine and engineering. The topics covered are the interaction of light and matter, the technology of synchrotron light sources, spectroscopy, imaging, scattering and diffraction of X-rays, and applications to materials science, biology, biochemistry, medicine, chemistry, food and pharmaceutical technology. All synchrotron light facilities are introduced with their home-page addresses. 'Synchrotron Light' provides an instructive and comprehensive multimedia learning tool for students, experienced practitioners and novices wishing to apply synchrotron radiation in their future work. Its multiple-entry points permit an easy exploration of the CD-Rom according to the users knowledge and interest. 2-D and 3-D animations and virtual reconstruction with computer-generated images guide visitors into the scientific and technical world of a synchrotron and into the applications of synchrotron radiation. This bilingual (English and French) CD-Rom can be used for self-teaching and in courses at various levels in physics, chemistry, engineering, and biology. (author)

  6. Pathogen reduction through additive-free short-wave UV light irradiation retains the optimal efficacy of human platelet lysate for the expansion of human bone marrow mesenchymal stem cells.

    Directory of Open Access Journals (Sweden)

    Sabrina Viau

    Full Text Available We recently developed and characterized a standardized and clinical grade human Platelet Lysate (hPL that constitutes an advantageous substitute for fetal bovine serum (FBS for human mesenchymal stem cell (hMSC expansion required in cell therapy procedures, avoiding xenogenic risks (virological and immunological and ethical issues. Because of the progressive use of pathogen-reduced (PR labile blood components, and the requirement of ensuring the viral safety of raw materials for cell therapy products, we evaluated the impact of the novel procedure known as THERAFLEX UV-Platelets for pathogen reduction on hPL quality (growth factors content and efficacy (as a medium supplement for hMSC expansion. This technology is based on short-wave ultraviolet light (UV-C that induces non-reversible damages in DNA and RNA of pathogens while preserving protein structures and functions, and has the main advantage of not needing the addition of any photosensitizing additives (that might secondarily interfere with hMSCs.We applied the THERAFLEX UV-Platelets procedure on fresh platelet concentrates (PCs suspended in platelet additive solution and prepared hPL from these treated PCs. We compared the quality and efficacy of PR-hPL with the corresponding non-PR ones. We found no impact on the content of five cytokines tested (EGF, bFGF, PDGF-AB, VEGF and IGF-1 but a significant decrease in TGF-ß1 (-21%, n = 11, p<0.01. We performed large-scale culture of hMSCs from bone marrow (BM during three passages and showed that hPL or PR-hPL at 8% triggered comparable BM-hMSC proliferation as FBS at 10% plus bFGF. Moreover, after proliferation of hMSCs in an hPL- or PR-hPL-containing medium, their profile of membrane marker expression, their clonogenic potential and immunosuppressive properties were maintained, in comparison with BM-hMSCs cultured under FBS conditions. The potential to differentiate towards the adipogenic and osteogenic lineages of hMSCs cultured in parallel

  7. Pathogen reduction through additive-free short-wave UV light irradiation retains the optimal efficacy of human platelet lysate for the expansion of human bone marrow mesenchymal stem cells.

    Science.gov (United States)

    Viau, Sabrina; Chabrand, Lucie; Eap, Sandy; Lorant, Judith; Rouger, Karl; Goudaliez, Francis; Sumian, Chryslain; Delorme, Bruno

    2017-01-01

    We recently developed and characterized a standardized and clinical grade human Platelet Lysate (hPL) that constitutes an advantageous substitute for fetal bovine serum (FBS) for human mesenchymal stem cell (hMSC) expansion required in cell therapy procedures, avoiding xenogenic risks (virological and immunological) and ethical issues. Because of the progressive use of pathogen-reduced (PR) labile blood components, and the requirement of ensuring the viral safety of raw materials for cell therapy products, we evaluated the impact of the novel procedure known as THERAFLEX UV-Platelets for pathogen reduction on hPL quality (growth factors content) and efficacy (as a medium supplement for hMSC expansion). This technology is based on short-wave ultraviolet light (UV-C) that induces non-reversible damages in DNA and RNA of pathogens while preserving protein structures and functions, and has the main advantage of not needing the addition of any photosensitizing additives (that might secondarily interfere with hMSCs). We applied the THERAFLEX UV-Platelets procedure on fresh platelet concentrates (PCs) suspended in platelet additive solution and prepared hPL from these treated PCs. We compared the quality and efficacy of PR-hPL with the corresponding non-PR ones. We found no impact on the content of five cytokines tested (EGF, bFGF, PDGF-AB, VEGF and IGF-1) but a significant decrease in TGF-ß1 (-21%, n = 11, p<0.01). We performed large-scale culture of hMSCs from bone marrow (BM) during three passages and showed that hPL or PR-hPL at 8% triggered comparable BM-hMSC proliferation as FBS at 10% plus bFGF. Moreover, after proliferation of hMSCs in an hPL- or PR-hPL-containing medium, their profile of membrane marker expression, their clonogenic potential and immunosuppressive properties were maintained, in comparison with BM-hMSCs cultured under FBS conditions. The potential to differentiate towards the adipogenic and osteogenic lineages of hMSCs cultured in parallel in the

  8. Lighting and public health.

    NARCIS (Netherlands)

    Ierland, J. van & Schreuder, D.A.

    1969-01-01

    The following topics; are discussed with respect to public health: - the effect of visible and ultraviolet radiation upon man. - vision with respect to lighting. interior lighting. - artificial lighting of work environments. - day light and windows. - recommendations for lighting. public lighting. -

  9. FACT light collection - solid light concentrators in Cherenkov Astronomy

    Energy Technology Data Exchange (ETDEWEB)

    Braun, Isabel [ETH Zurich, Institute for Particle Physics, CH-8093 Zurich (Switzerland); Collaboration: FACT-Collaboration

    2011-07-01

    Pixelized cameras of Imaging Atmospheric Cherenkov Telescopes use hollow light guides with reflective surfaces based on the Winston cone design. These cones minimize insensitive spaces between the photo sensors and shield the camera from stray background light by limiting the angular acceptance to the primary reflector area. FACT (First G-APD Cherenkov Telescope) will be the first IACT with Geiger-mode avalanche photodiodes as light sensors. Solid light concentrators complementing these sensors will be used instead of hollow Winston cones. We will present simulations and measurements of our light collector design, which was optimized for the requirements of the FACT telescope and detector, and discuss the specific differences to more traditional solutions.

  10. RF Gun Optimization Study

    International Nuclear Information System (INIS)

    Alicia Hofler; Pavel Evtushenko

    2007-01-01

    Injector gun design is an iterative process where the designer optimizes a few nonlinearly interdependent beam parameters to achieve the required beam quality for a particle accelerator. Few tools exist to automate the optimization process and thoroughly explore the parameter space. The challenging beam requirements of new accelerator applications such as light sources and electron cooling devices drive the development of RF and SRF photo injectors. A genetic algorithm (GA) has been successfully used to optimize DC photo injector designs at Cornell University [1] and Jefferson Lab [2]. We propose to apply GA techniques to the design of RF and SRF gun injectors. In this paper, we report on the initial phase of the study where we model and optimize a system that has been benchmarked with beam measurements and simulation

  11. Calculus light

    CERN Document Server

    Friedman, Menahem

    2011-01-01

    Another Calculus book? As long as students find calculus scary, the failure rate in mathematics is higher than in all other subjects, and as long as most people mistakenly believe that only geniuses can learn and understand mathematics, there will always be room for a new book of Calculus. We call it Calculus Light. This book is designed for a one semester course in ""light"" calculus -- mostly single variable, meant to be used by undergraduate students without a wide mathematical background and who do not major in mathematics but study subjects such as engineering, biology or management infor

  12. Lighting Design

    DEFF Research Database (Denmark)

    Hansen, Ellen Kathrine; Mullins, Michael

    2014-01-01

    of design developed from three experiments show how distinct qualitative and quantitative criteria in different disciplinary traditions can be integrated successfully, despite disparate technical/scientific, social scientific and art/humanities backgrounds. The model is applied to a pedagogical curriculum......Light as a multi-dimensional design element has fundamental importance for a sustainable environment. The paper discusses the need for an integration of scientific, technical and creative approaches to light and presents theory, methods and applications toward fulfilling this need. A theory...

  13. LIGHT TITRATIONS

    Science.gov (United States)

    Field, John; Baas-Becking, Lourens G. M.

    1926-01-01

    1. The usefulness of the radiomicrometer in titration work has been pointed out. The authors suggest that light titration may also be used where a reaction mixture changes its absorption in the (near) infra-red. 2. The applicability of this method to the starch-iodine reaction has been demonstrated. PMID:19872266

  14. The Advanced Light Source

    International Nuclear Information System (INIS)

    Jackson, A.

    1991-05-01

    The Advanced Light Source (ALS), a national user facility currently under construction at the Lawrence Berkeley Laboratory (LBL), is a third-generation synchrotron light source designed to produce extremely bright beams of synchrotron radiation in the energy range from a few eV to 10 keV. The design is based on a 1--1.9-GeV electron storage ring (optimized at 1.5 GeV), and utilizes special magnets, known as undulators and wigglers (collectively referred to as insertion devices), to generate the radiation. The facility is scheduled to begin operating in April 1993. In this paper we describe the progress in the design, construction, and commissioning of the accelerator systems, insertion devices, and beamlines. Companion presentations at this conference give more detail of specific components in the ALS, and describe the activities towards establishing an exciting user program. 3 figs., 2 tabs

  15. Distributed Optimization System

    Science.gov (United States)

    Hurtado, John E.; Dohrmann, Clark R.; Robinett, III, Rush D.

    2004-11-30

    A search system and method for controlling multiple agents to optimize an objective using distributed sensing and cooperative control. The search agent can be one or more physical agents, such as a robot, and can be software agents for searching cyberspace. The objective can be: chemical sources, temperature sources, radiation sources, light sources, evaders, trespassers, explosive sources, time dependent sources, time independent sources, function surfaces, maximization points, minimization points, and optimal control of a system such as a communication system, an economy, a crane, and a multi-processor computer.

  16. BERKELEY: Light Source anniversary

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    The staff of the Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory has been too busy to celebrate the first anniversary of the facility's transition from a US Department of Energy construction project to operating third-generation synchrotron radiation source. Based on a 1.5-GeV, low-emittance electron storage ring that accommodates up to ten insertion-device radiation sources optimized primarily for the soft X-ray and vacuum ultra-violet regions of the spectrum, the ALS has completed

  17. BERKELEY: Light Source anniversary

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1994-10-15

    The staff of the Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory has been too busy to celebrate the first anniversary of the facility's transition from a US Department of Energy construction project to operating third-generation synchrotron radiation source. Based on a 1.5-GeV, low-emittance electron storage ring that accommodates up to ten insertion-device radiation sources optimized primarily for the soft X-ray and vacuum ultra-violet regions of the spectrum, the ALS has completed.

  18. "Light sail" acceleration reexamined.

    Science.gov (United States)

    Macchi, Andrea; Veghini, Silvia; Pegoraro, Francesco

    2009-08-21

    The dynamics of the acceleration of ultrathin foil targets by the radiation pressure of superintense, circularly polarized laser pulses is investigated by analytical modeling and particle-in-cell simulations. By addressing self-induced transparency and charge separation effects, it is shown that for "optimal" values of the foil thickness only a thin layer at the rear side is accelerated by radiation pressure. The simple "light sail" model gives a good estimate of the energy per nucleon, but overestimates the conversion efficiency of laser energy into monoenergetic ions.

  19. 'Light Sail' Acceleration Reexamined

    International Nuclear Information System (INIS)

    Macchi, Andrea; Veghini, Silvia; Pegoraro, Francesco

    2009-01-01

    The dynamics of the acceleration of ultrathin foil targets by the radiation pressure of superintense, circularly polarized laser pulses is investigated by analytical modeling and particle-in-cell simulations. By addressing self-induced transparency and charge separation effects, it is shown that for 'optimal' values of the foil thickness only a thin layer at the rear side is accelerated by radiation pressure. The simple 'light sail' model gives a good estimate of the energy per nucleon, but overestimates the conversion efficiency of laser energy into monoenergetic ions.

  20. Phosphor converted laser diode light source for endoscopic diagnostics

    DEFF Research Database (Denmark)

    Krasnoshchoka, Anastasiia; Thorseth, Anders; Dam-Hansen, Carsten

    2017-01-01

    of the generated white light into thin optical fibres. The development involves designing optics for optimizing the light extraction efficiency and guiding of light to the area of interest. In this paper we compared the developed light source to the current standard in endoscopy – xenon arc lamps. Detailed...

  1. Green lights

    DEFF Research Database (Denmark)

    Fisker, Peter Kielberg

    This study investigates the effect of drought on economic activity globally using remote sensing data. In particular, predicted variation in greenness is correlated with changes in the density of artificial light observed at night on a grid of 0.25 degree latitude-longitude pixels. I define drought...... as greenness estimated by lagged variation in monthly rainfall and temperature. This definition of drought performs well in identifying self-reported drought events since 2000 compared with measures of drought that do not take greenness into account, and the subsequent analysis indicates that predicted...... variation in greenness is positively associated with year-on-year changes in luminosity: If a unit of observation experiences a predicted variation in greenness that lies 1 standard deviation below the global mean, on average 1.5 - 2.5 light pixels out of 900 are extinguished that year. Finally, an attempt...

  2. Energy efficient solid state lighting

    Energy Technology Data Exchange (ETDEWEB)

    Dam-Hansen, C.; Petersen, Poul Michael

    2012-11-15

    Even though vast improvements have been made on efficiency and light quality, SSL is still in its infancy. One of the barriers for a market introduction is the price, which still is around 5 times higher than traditional lighting technologies. In order to fulfil the potential of SSL, further research and development needs to increase the light extraction from semiconductor materials, provide better and cheaper production and packaging, and advanced optical systems for optimized light distribution and new thermal solutions for SSL lamps and luminaires. Nanotechnology and applied research at DTU Fotonik in close collaboration with industry are essential parts in the development of new enhanced LED optical systems and LEDs with higher light extraction efficiency. Photonic crystals can help to efficiently extract light from LEDs and to form a desired emission profile. Future directions are devoted to the next generation of LEDs, in which the spontaneous emission is photon enhanced. One realization of this idea is using LEDs with a layer of nanocrystals, which are coupled to the quantum well of the LED. Such R and D work is ongoing all over the world and DOE roadmaps foresee luminous efficiencies by 2020 that are close to 250 lm/W for both cold and warm white light from LEDs, and prices in the order of one dollar per kilolumen. Such figures will drastically reduce the energy consumption worldwide for lighting, and hence a marked reduction in carbon emissions. (Author)

  3. Handbook of industrial lighting

    CERN Document Server

    Lyons, Stanley L

    2013-01-01

    Handbook of Industrial Lighting is a practical guide on the specification, design, installation, operation, and maintenance of lighting in industrial premises. Coverage of the book includes the importance of good localized lighting; the different lighting schemes; lighting for difficult visual tasks; lighting in consideration to safety; and emergency lighting. The book also includes the practical, thermal, ventilation, and energy considerations; lighting in different environments; maintenance of lighting installations; and the cost benefits of efficient lighting. Appendices include useful info

  4. Shaping light

    CSIR Research Space (South Africa)

    Forbes, A

    2010-01-01

    Full Text Available Laser, a high- power laser to shoot down missiles, fills an entire Boeing 747! By customising the laser resonator it is possible to design light to order. Laser technology has been around for 50 years, yet new research and ideas are ensuring... that it will remain an active area of investigation for years to come. ? Professor Andrew Forbes is Chief Researcher and Research Group Leader at the CSIR National Laser Centre, and holds honorary positions in the Schools of Physics at both the University...

  5. Optimized packings with applications

    CERN Document Server

    Pintér, János

    2015-01-01

    This volume presents a selection of case studies that address a substantial range of optimized object packings (OOP) and their applications. The contributing authors are well-recognized researchers and practitioners. The mathematical modelling and numerical solution aspects of each application case study are presented in sufficient detail. A broad range of OOP problems are discussed: these include various specific and non-standard container loading and object packing problems, as well as the stowing of hazardous and other materials on container ships, data centre resource management, automotive engineering design, space station logistic support, cutting and packing problems with placement constraints, the optimal design of LED street lighting, robust sensor deployment strategies, spatial scheduling problems, and graph coloring models and metaheuristics for packing applications. Novel points of view related to model development and to computational nonlinear, global, mixed integer optimization and heuristic st...

  6. Nonlinear optimization

    CERN Document Server

    Ruszczynski, Andrzej

    2011-01-01

    Optimization is one of the most important areas of modern applied mathematics, with applications in fields from engineering and economics to finance, statistics, management science, and medicine. While many books have addressed its various aspects, Nonlinear Optimization is the first comprehensive treatment that will allow graduate students and researchers to understand its modern ideas, principles, and methods within a reasonable time, but without sacrificing mathematical precision. Andrzej Ruszczynski, a leading expert in the optimization of nonlinear stochastic systems, integrates the theory and the methods of nonlinear optimization in a unified, clear, and mathematically rigorous fashion, with detailed and easy-to-follow proofs illustrated by numerous examples and figures. The book covers convex analysis, the theory of optimality conditions, duality theory, and numerical methods for solving unconstrained and constrained optimization problems. It addresses not only classical material but also modern top...

  7. Website Optimization

    CERN Document Server

    King, Andrew

    2008-01-01

    Remember when an optimized website was one that merely didn't take all day to appear? Times have changed. Today, website optimization can spell the difference between enterprise success and failure, and it takes a lot more know-how to achieve success. This book is a comprehensive guide to the tips, techniques, secrets, standards, and methods of website optimization. From increasing site traffic to maximizing leads, from revving up responsiveness to increasing navigability, from prospect retention to closing more sales, the world of 21st century website optimization is explored, exemplified a

  8. A lighting metric for quantitative evaluation of accent lighting systems

    Science.gov (United States)

    Acholo, Cyril O.; Connor, Kenneth A.; Radke, Richard J.

    2014-09-01

    Accent lighting is critical for artwork and sculpture lighting in museums, and subject lighting for stage, Film and television. The research problem of designing effective lighting in such settings has been revived recently with the rise of light-emitting-diode-based solid state lighting. In this work, we propose an easy-to-apply quantitative measure of the scene's visual quality as perceived by human viewers. We consider a well-accent-lit scene as one which maximizes the information about the scene (in an information-theoretic sense) available to the user. We propose a metric based on the entropy of the distribution of colors, which are extracted from an image of the scene from the viewer's perspective. We demonstrate that optimizing the metric as a function of illumination configuration (i.e., position, orientation, and spectral composition) results in natural, pleasing accent lighting. We use a photorealistic simulation tool to validate the functionality of our proposed approach, showing its successful application to two- and three-dimensional scenes.

  9. Optimality Conditions in Vector Optimization

    CERN Document Server

    Jiménez, Manuel Arana; Lizana, Antonio Rufián

    2011-01-01

    Vector optimization is continuously needed in several science fields, particularly in economy, business, engineering, physics and mathematics. The evolution of these fields depends, in part, on the improvements in vector optimization in mathematical programming. The aim of this Ebook is to present the latest developments in vector optimization. The contributions have been written by some of the most eminent researchers in this field of mathematical programming. The Ebook is considered essential for researchers and students in this field.

  10. Medicinsk Optimering

    DEFF Research Database (Denmark)

    Birkholm, Klavs

    2010-01-01

    En undersøgelse af anvendelsen af medicin til optimering af koncentration, hukommelse og følelsestonus. Efterfulgt af etiske overvejelser og anbefalinger til det politiske system......En undersøgelse af anvendelsen af medicin til optimering af koncentration, hukommelse og følelsestonus. Efterfulgt af etiske overvejelser og anbefalinger til det politiske system...

  11. Structural optimization

    CERN Document Server

    MacBain, Keith M

    2009-01-01

    Intends to supplement the engineer's box of analysis and design tools making optimization as commonplace as the finite element method in the engineering workplace. This title introduces structural optimization and the methods of nonlinear programming such as Lagrange multipliers, Kuhn-Tucker conditions, and calculus of variations.

  12. Topology Optimization

    DEFF Research Database (Denmark)

    A. Kristensen, Anders Schmidt; Damkilde, Lars

    2007-01-01

    . A way to solve the initial design problem namely finding a form can be solved by so-called topology optimization. The idea is to define a design region and an amount of material. The loads and supports are also fidefined, and the algorithm finds the optimal material distribution. The objective function...... dictates the form, and the designer can choose e.g. maximum stiness, maximum allowable stresses or maximum lowest eigenfrequency. The result of the topology optimization is a relatively coarse map of material layout. This design can be transferred to a CAD system and given the necessary geometrically...... refinements, and then remeshed and reanalysed in other to secure that the design requirements are met correctly. The output of standard topology optimization has seldom well-defined, sharp contours leaving the designer with a tedious interpretation, which often results in less optimal structures. In the paper...

  13. Dispositional Optimism

    Science.gov (United States)

    Carver, Charles S.; Scheier, Michael F.

    2014-01-01

    Optimism is a cognitive construct (expectancies regarding future outcomes) that also relates to motivation: optimistic people exert effort, whereas pessimistic people disengage from effort. Study of optimism began largely in health contexts, finding positive associations between optimism and markers of better psychological and physical health. Physical health effects likely occur through differences in both health-promoting behaviors and physiological concomitants of coping. Recently, the scientific study of optimism has extended to the realm of social relations: new evidence indicates that optimists have better social connections, partly because they work harder at them. In this review, we examine the myriad ways this trait can benefit an individual, and our current understanding of the biological basis of optimism. PMID:24630971

  14. Lighting Automation Flying an Earthlike Habitat

    Science.gov (United States)

    Clark, Toni A.; Kolomenski, Andrei

    2017-01-01

    Currently, spacecraft lighting systems are not demonstrating innovations in automation due to perceived costs in designing circuitry for the communication and automation of lights. The majority of spacecraft lighting systems employ lamps or zone specific manual switches and dimmers. This type of 'hardwired' solution does not easily convert to automation. With advances in solid state lighting, the potential to enhance a spacecraft habitat is lost if the communication and automation problem is not tackled. If we are to build long duration environments, which provide earth-like habitats, minimize crew time, and optimize spacecraft power reserves, innovation in lighting automation is a must. This project researched the use of the DMX512 communication protocol originally developed for high channel count lighting systems. DMX512 is an internationally governed, industry-accepted, lighting communication protocol with wide industry support. The lighting industry markets a wealth of hardware and software that utilizes DMX512, and there may be incentive to space certify the system. Our goal in this research is to enable the development of automated spacecraft habitats for long duration missions. To transform how spacecraft lighting environments are automated, our project conducted a variety of tests to determine a potential scope of capability. We investigated utilization and application of an industry accepted lighting control protocol, DMX512 by showcasing how the lighting system could help conserve power, assist with lighting countermeasures, and utilize spatial body tracking. We hope evaluation and the demonstrations we built will inspire other NASA engineers, architects and researchers to consider employing DMX512 "smart lighting" capabilities into their system architecture. By using DMX512 we will prove the 'wheel' does not need to be reinvented in terms of smart lighting and future spacecraft can use a standard lighting protocol to produce an effective, optimized and

  15. Lighting Automation - Flying an Earthlike Habitat

    Science.gov (United States)

    Clark, Tori A. (Principal Investigator); Kolomenski, Andrei

    2017-01-01

    Currently, spacecraft lighting systems are not demonstrating innovations in automation due to perceived costs in designing circuitry for the communication and automation of lights. The majority of spacecraft lighting systems employ lamps or zone specific manual switches and dimmers. This type of 'hardwired' solution does not easily convert to automation. With advances in solid state lighting, the potential to enhance a spacecraft habitat is lost if the communication and automation problem is not tackled. If we are to build long duration environments, which provide earth-like habitats, minimize crew time, and optimize spacecraft power reserves, innovation in lighting automation is a must. This project researched the use of the DMX512 communication protocol originally developed for high channel count lighting systems. DMX512 is an internationally governed, industry-accepted, lighting communication protocol with wide industry support. The lighting industry markets a wealth of hardware and software that utilizes DMX512, and there may be incentive to space certify the system. Our goal in this research is to enable the development of automated spacecraft habitats for long duration missions. To transform how spacecraft lighting environments are automated, our project conducted a variety of tests to determine a potential scope of capability. We investigated utilization and application of an industry accepted lighting control protocol, DMX512 by showcasing how the lighting system could help conserve power, assist with lighting countermeasures, and utilize spatial body tracking. We hope evaluation and the demonstrations we built will inspire other NASA engineers, architects and researchers to consider employing DMX512 "smart lighting" capabilities into their system architecture. By using DMX512 we will prove the 'wheel' does not need to be reinvented in terms of smart lighting and future spacecraft can use a standard lighting protocol to produce an effective, optimized and

  16. Intense beams of light ions

    International Nuclear Information System (INIS)

    Camarcat, Noel

    1985-01-01

    Results of experiments performed in order to accelerate intense beams of light and heavier ions are presented. The accelerating diodes are driven by existing pulsed power generators. Optimization of the generator structure is described in chapter I. Nuclear diagnostics of the accelerated light ion beams are presented in chapter II. Chapter III deals with the physics of intense charged particle beams. The models developed are applied to the calculation of the performances of the ion diodes described in the previous chapters. Chapter IV reports preliminary results on a multiply ionized carbon source driven by a 0.1 TW pulsed power generator. (author) [fr

  17. Fish with red fluorescent eyes forage more efficiently under dim, blue-green light conditions.

    Science.gov (United States)

    Harant, Ulrike Katharina; Michiels, Nicolaas Karel

    2017-04-20

    Natural red fluorescence is particularly conspicuous in the eyes of some small, benthic, predatory fishes. Fluorescence also increases in relative efficiency with increasing depth, which has generated speculation about its possible function as a "light organ" to detect cryptic organisms under bluish light. Here we investigate whether foraging success is improved under ambient conditions that make red fluorescence stand out more, using the triplefin Tripterygion delaisi as a model system. We repeatedly presented 10 copepods to individual fish (n = 40) kept under a narrow blue-green spectrum and compared their performance with that under a broad spectrum with the same overall brightness. The experiment was repeated for two levels of brightness, a shaded one representing 0.4% of the light present at the surface and a heavily shaded one with about 0.01% of the surface brightness. Fish were 7% more successful at catching copepods under the narrow, fluorescence-friendly spectrum than under the broad spectrum. However, this effect was significant under the heavily shaded light treatment only. This outcome corroborates previous predictions that fluorescence may be an adaptation to blue-green, heavily shaded environments, which coincides with the opportunistic biology of this species that lives in the transition zone between exposed and heavily shaded microhabitats.

  18. SPES, Fuel Cycle Optimization for LWR

    International Nuclear Information System (INIS)

    1973-01-01

    1 - Nature of physical problem solved: Determination of optimal fuel cycle at equilibrium for a light water reactor taking into account batch size, fuel enrichment, de-rating, shutdown time, cost of replacement energy. 2 - Method of solution: Iterative method

  19. Portfolio Optimization

    OpenAIRE

    Issagali, Aizhan; Alshimbayeva, Damira; Zhalgas, Aidana

    2015-01-01

    In this paper Portfolio Optimization techniques were used to determine the most favorable investment portfolio. In particular, stock indices of three companies, namely Microsoft Corporation, Christian Dior Fashion House and Shevron Corporation were evaluated. Using this data the amounts invested in each asset when a portfolio is chosen on the efficient frontier were calculated. In addition, the Portfolio with minimum variance, tangency portfolio and optimal Markowitz portfolio are presented.

  20. Light robotics: a new field of research

    DEFF Research Database (Denmark)

    Engay, Einstom; Chouliara, Manto; Bañas, Andrew

    2018-01-01

    After years of working on light-driven trapping and manipulation, we can see that a confluence of developments is now ripe for the emergence of a new area that can contribute to nanobiophotonics - Light Robotics - which combines advances in microfabrication and optical micromanipulation together...... with intelligent control ideas from robotics, wavefront engineering and information optics. In the Summer 2017 we are publishing a 482 pages edited Elsevier book volume covering the fundamental aspects needed for Light Robotics including optical trapping systems, microfabrication and microassembly as well...... as underlying theoretical principles and experimental illustrations for optimizing optical forces and torques for Light Robotics...

  1. Hyperspectral light sheet microscopy

    Science.gov (United States)

    Jahr, Wiebke; Schmid, Benjamin; Schmied, Christopher; Fahrbach, Florian O.; Huisken, Jan

    2015-09-01

    To study the development and interactions of cells and tissues, multiple fluorescent markers need to be imaged efficiently in a single living organism. Instead of acquiring individual colours sequentially with filters, we created a platform based on line-scanning light sheet microscopy to record the entire spectrum for each pixel in a three-dimensional volume. We evaluated data sets with varying spectral sampling and determined the optimal channel width to be around 5 nm. With the help of these data sets, we show that our setup outperforms filter-based approaches with regard to image quality and discrimination of fluorophores. By spectral unmixing we resolved overlapping fluorophores with up to nanometre resolution and removed autofluorescence in zebrafish and fruit fly embryos.

  2. Controlling the speed of light

    DEFF Research Database (Denmark)

    Sigmund, Ole; Stainko, Roman

    Interesting phenomena of photonic crystals (PhCs), like bandgaps and waveguiding, have lead to a tremendous increase of research interest in this area. High-end functionalities in electro-optical circuts urge to optimize these structures. So far mostly trial and error methods have been applied to...... method to not only to create a bandgap around an a-priorily chosen guided mode, but also to control it's group-velocity under the light-line....

  3. Optimization of lamp spectrum for vegetable growth

    Energy Technology Data Exchange (ETDEWEB)

    Prikupets, L.B.; Tikhomirov, A.A. [Institute of Biophysics, Krasnoyarsk (Russian Federation)

    1994-12-31

    Commmercial light sources were evaluated as to the optimum conditions for the production of tomatoes and cucumbers. Data is presented which corresponds to the maximum productivity and optimal spectral ratios. It is suggested that the commercial light sources evaluated were not efficient for the growing of the vegetables.

  4. Radiological optimization

    International Nuclear Information System (INIS)

    Zeevaert, T.

    1998-01-01

    Radiological optimization is one of the basic principles in each radiation-protection system and it is a basic requirement in the safety standards for radiation protection in the European Communities. The objectives of the research, performed in this field at the Belgian Nuclear Research Centre SCK-CEN, are: (1) to implement the ALARA principles in activities with radiological consequences; (2) to develop methodologies for optimization techniques in decision-aiding; (3) to optimize radiological assessment models by validation and intercomparison; (4) to improve methods to assess in real time the radiological hazards in the environment in case of an accident; (5) to develop methods and programmes to assist decision-makers during a nuclear emergency; (6) to support the policy of radioactive waste management authorities in the field of radiation protection; (7) to investigate existing software programmes in the domain of multi criteria analysis. The main achievements for 1997 are given

  5. Optimizing detectability

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    HPLC is useful for trace and ultratrace analyses of a variety of compounds. For most applications, HPLC is useful for determinations in the nanogram-to-microgram range; however, detection limits of a picogram or less have been demonstrated in certain cases. These determinations require state-of-the-art capability; several examples of such determinations are provided in this chapter. As mentioned before, to detect and/or analyze low quantities of a given analyte at submicrogram or ultratrace levels, it is necessary to optimize the whole separation system, including the quantity and type of sample, sample preparation, HPLC equipment, chromatographic conditions (including column), choice of detector, and quantitation techniques. A limited discussion is provided here for optimization based on theoretical considerations, chromatographic conditions, detector selection, and miscellaneous approaches to detectability optimization. 59 refs

  6. Unconstrained Optimization

    DEFF Research Database (Denmark)

    Frandsen, P. E.; Jonasson, K.; Nielsen, Hans Bruun

    1999-01-01

    This lecture note is intended for use in the course 04212 Optimization and Data Fitting at the Technincal University of Denmark. It covers about 25% of the curriculum. Hopefully, the note may be useful also to interested persons not participating in that course. The aim of the note is to give...... an introduction to algorithms for unconstrained optimization. We present Conjugate Gradient, Damped Newton and Quasi Newton methods together with the relevant theoretical background. The reader is assumed to be familiar with algorithms for solving linear and nonlinear system of equations, at a level corresponding...

  7. The use of Design of Experiments and Response Surface Methodology to optimize biomass and lipid production by the oleaginous marine green alga, Nannochloropsis gaditana in response to light intensity, inoculum size and CO2.

    Science.gov (United States)

    Hallenbeck, Patrick C; Grogger, Melanie; Mraz, Megan; Veverka, Donald

    2015-05-01

    Biodiesel produced from microalgal lipids is being considered as a potential source of renewable energy. However, a number of hurdles will have to be overcome if such a process is to become practical. One important factor is the volumetric production of biomass and lipid that can be achieved. The marine alga Nannochloropsis gaditana is under study since it is known to be highly oleaginous and has a number of other attractive properties. Factors that might be important in biomass and lipid production by this alga are light intensity, inoculum size and CO2. Here we have carried out for the first time a RSM-DOE study of the influence of these important culture variables and define conditions that maximize biomass production, lipid content (BODIPY® fluorescence) and total lipid production. Moreover, flow cytometry allowed the examination on a cellular level of changes that occur in cellular populations as they age and accumulate lipids. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Lighting Options for Homes.

    Energy Technology Data Exchange (ETDEWEB)

    Baker, W.S.

    1991-04-01

    This report covers many aspects of various lighting options for homes. Types of light sources described include natural light, artificial light, incandescent lamps, fluorescent lamps, and high intensity discharge lamps. A light source selection guide gives the physical characteristics of these, design considerations, and common applications. Color, strategies for efficient lighting, and types of lighting are discussed. There is one section giving tips for various situations in specific rooms. Rooms and types of fixtures are shown on a matrix with watts saved by using the recommended type lighting for that room and room location. A major emphasis of this report is saving energy by utilizing the most suitable, recommended lighting option. (BN)

  9. Urban lighting, light pollution and society

    CERN Document Server

    Meier, Josiane; Krause, Katharina; Pottharst, Merle

    2014-01-01

    After decades "in the shadows", urban lighting is re-emerging as a matter of public debate. Long-standing truths are increasingly questioned as a confluence of developments affects lighting itself and the way it is viewed. Light has become an integral element of place-making and energy-saving initiatives alike. Rapidly evolving lighting technologies are opening up new possibilities, but also posing new challenges to planners, and awareness is growing that artificial illumination is not purely benign but can actually constitute a form of pollution. As a result, public policy frameworks, incentives and initiatives are undergoing a phase of innovation and change that will affect how cities are lit for years to come. The first comprehensive compilation of current scientific discussions on urban lighting and light pollution from a social science and humanities perspective, Urban Lighting, Light Pollution and Society contributes to an evolving international debate on an increasingly controversial topic. The contrib...

  10. Light up My Life

    Science.gov (United States)

    Kellett, Sarah

    2015-01-01

    Simply stated, light is nature's way of transferring energy through space. Discussions of light usually refer to visible light, which is perceived by the human eye and is responsible for the sense of sight. We see however, only a small part of the light spectrum. Light connects us as we sit and tell yarns around camp fires. Yet, one in every four…

  11. Mobile lighting apparatus

    Science.gov (United States)

    Roe, George Michael; Klebanoff, Leonard Elliott; Rea, Gerald W; Drake, Robert A; Johnson, Terry A; Wingert, Steven John; Damberger, Thomas A; Skradski, Thomas J; Radley, Christopher James; Oros, James M; Schuttinger, Paul G; Grupp, David J; Prey, Stephen Carl

    2013-05-14

    A mobile lighting apparatus includes a portable frame such as a moveable trailer or skid having a light tower thereon. The light tower is moveable from a stowed position to a deployed position. A hydrogen-powered fuel cell is located on the portable frame to provide electrical power to an array of the energy efficient lights located on the light tower.

  12. Optimal transport

    CERN Document Server

    Eckmann, B

    2008-01-01

    At the close of the 1980s, the independent contributions of Yann Brenier, Mike Cullen and John Mather launched a revolution in the venerable field of optimal transport founded by G Monge in the 18th century, which has made breathtaking forays into various other domains of mathematics ever since. The author presents a broad overview of this area.

  13. Topology optimization

    DEFF Research Database (Denmark)

    Bendsøe, Martin P.; Sigmund, Ole

    2007-01-01

    Taking as a starting point a design case for a compliant mechanism (a force inverter), the fundamental elements of topology optimization are described. The basis for the developments is a FEM format for this design problem and emphasis is given to the parameterization of design as a raster image...

  14. Solar concentrator with integrated tracking and light delivery system with collimation

    Science.gov (United States)

    Maxey, Lonnie Curt

    2015-06-09

    A solar light distribution system includes a solar light concentrator that is affixed externally to a light transfer tube. Solar light waves are processed by the concentrator into a collimated beam of light, which is then transferred through a light receiving port and into the light transfer tube. A reflector directs the collimated beam of light through the tube to a light distribution port. The interior surface of the light transfer tube is highly reflective so that the light transfers through the tube with minimal losses. An interchangeable luminaire is attached to the light distribution port and distributes light inside of a structure. A sun tracking device rotates the concentrator and the light transfer tube to optimize the receiving of solar light by the concentrator throughout the day. The system provides interior lighting, uses only renewable energy sources, and releases no carbon dioxide emissions into the atmosphere.

  15. Solar concentrator with integrated tracking and light delivery system with summation

    Science.gov (United States)

    Maxey, Lonnie Curt

    2015-05-05

    A solar light distribution system includes a solar light concentrator that is affixed externally to a light transfer tube. Solar light waves are processed by the concentrator into a collimated beam of light, which is then transferred through a light receiving port and into the light transfer tube. A reflector redirects the collimated beam of light through the tube to a light distribution port. The interior surface of the light transfer tube is highly reflective so that the light transfers through the tube with minimal losses. An interchangeable luminaire is attached to the light distribution port and provides light inside of a structure. A sun tracking device rotates the concentrator and the light transfer tube to optimize the receiving of solar light by the concentrator throughout the day. The system provides interior lighting that uses only renewable energy sources, and releases no carbon dioxide emissions into the atmosphere.

  16. Designing an optimally proportional inorganic scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Jai, E-mail: jai.singh@cdu.edu.au [School of Engineering and IT, B-Purple-12, Faculty of EHSE, Charles Darwin University, NT 0909 (Australia); Koblov, Alexander [School of Engineering and IT, B-Purple-12, Faculty of EHSE, Charles Darwin University, NT 0909 (Australia)

    2012-09-01

    The nonproportionality observed in the light yield of inorganic scintillators is studied theoretically as a function of the rates of bimolecular and Auger quenching processes occurring within the electron track initiated by a gamma- or X-ray photon incident on a scintillator. Assuming a cylindrical track, the influence of the track radius and concentration of excitations created within the track on the scintillator light yield is also studied. Analysing the calculated light yield a guideline for inventing an optimally proportional scintillator with optimal energy resolution is presented.

  17. Designing an optimally proportional inorganic scintillator

    International Nuclear Information System (INIS)

    Singh, Jai; Koblov, Alexander

    2012-01-01

    The nonproportionality observed in the light yield of inorganic scintillators is studied theoretically as a function of the rates of bimolecular and Auger quenching processes occurring within the electron track initiated by a gamma- or X-ray photon incident on a scintillator. Assuming a cylindrical track, the influence of the track radius and concentration of excitations created within the track on the scintillator light yield is also studied. Analysing the calculated light yield a guideline for inventing an optimally proportional scintillator with optimal energy resolution is presented.

  18. Lighting design for globally illuminated volume rendering.

    Science.gov (United States)

    Zhang, Yubo; Ma, Kwan-Liu

    2013-12-01

    With the evolution of graphics hardware, high quality global illumination becomes available for real-time volume rendering. Compared to local illumination, global illumination can produce realistic shading effects which are closer to real world scenes, and has proven useful for enhancing volume data visualization to enable better depth and shape perception. However, setting up optimal lighting could be a nontrivial task for average users. There were lighting design works for volume visualization but they did not consider global light transportation. In this paper, we present a lighting design method for volume visualization employing global illumination. The resulting system takes into account view and transfer-function dependent content of the volume data to automatically generate an optimized three-point lighting environment. Our method fully exploits the back light which is not used by previous volume visualization systems. By also including global shadow and multiple scattering, our lighting system can effectively enhance the depth and shape perception of volumetric features of interest. In addition, we propose an automatic tone mapping operator which recovers visual details from overexposed areas while maintaining sufficient contrast in the dark areas. We show that our method is effective for visualizing volume datasets with complex structures. The structural information is more clearly and correctly presented under the automatically generated light sources.

  19. Improved light trapping in polymer solar cells by light diffusion ink

    International Nuclear Information System (INIS)

    Chao, Yu-Chiang; Lin, Yun-Hsuan; Lin, Ching-Yi; Li, Husan-De; Zhan, Fu-Min; Huang, Yu-Zhang

    2014-01-01

    Light trapping is an important issue for solar cells to increase optical path length and optical absorption. In this work, a light trapping structure was realized for polymer solar cells by utilizing light diffusion ink which is conventionally used in display backlighting. The light scattering particles in the ink cause the deflection of light, and the number of these particles coated on a glass substrate determines the light transmission and scattering characteristics. It was observed that the short-circuit current density did not decrease with decreasing transmittance, but it increased to a highest value at an optimized transmittance. This behaviour is attributed to the trapping of scattered light in the photoactive layer. (paper)

  20. Energy Efficient Task Light

    DEFF Research Database (Denmark)

    Logadottir, Asta; Ardkapan, Siamak Rahimi; Johnsen, Kjeld

    2014-01-01

    The objectives of this work is to develop a task light for office lighting that fulfils the minimum requirements of the European standard EN12464 - 1 : Light and lightingLighting of work places, Part 1: Indoor workplaces and the Danish standard DS 700 : Lys og belysning I arbejdsrum , or more...... specifically the requirements that apply to the work area and the immediate surrounding area. By providing a task light that fulfils the requirements for task lighting and the immediate surrounding area, the general lighting only needs to provide the illuminance levels required for background lighting...... and thereby a reduction in installed power for general lighting of about 40 % compared to the way illuminance levels are designed in an office environment in Denmark today. This lighting strategy is useful when the placement of the task area is not defined in the space before the lighting is design ed...

  1. Light-based therapies in acne treatment

    Science.gov (United States)

    Pei, Susan; Inamadar, Arun C.; Adya, Keshavmurthy A.; Tsoukas, Maria M.

    2015-01-01

    The use of light and laser in the treatment of acne is increasing as these modalities are safe, effective, and associated with no or minimal complications when used appropriately. These light and laser sources are also being used in combination with pharmacological and/or physical measures to synergize their effects and optimize the therapeutic outcome. This review focuses on optical devices used in treating acne and serves to delineate the current application of various methods, including their utility and efficacy. PMID:26009707

  2. High efficiency orange-red phosphorescent organic light emitting diodes based on a Pt(II)-pyridyltriazolate complex from a structure optimized for charge balance and reduced efficiency roll-off

    Energy Technology Data Exchange (ETDEWEB)

    Li, Minghang; Lin, Ming-Te; Shepherd, Nigel D. [Department of Material Science and Engineering, University of North Texas, Denton, Texas (United States); Chen, Wei-Hsuan; McDougald, Roy Jr.; Arvapally, Ravi; Omary, Mohammad [Department of Chemistry, University of North Texas, Denton, Texas (United States)

    2012-01-15

    We report a high power efficiency (PE) of 44.7 {+-} 0.5 lm/W, high external quantum efficiency (EQE) of 19.7 {+-} 0.1% at 500 Cd/m{sup 2}, and efficiency roll-off of only 4% of the peak value at a useful brightness of 1000 Cd/m{sup 2} from orange-red emitting, organic light emitting diodes featuring 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC) as the hole transport layer/electron blocking layer, an emissive layer consisting of 65% bis[3,5-bis(2-pyridyl)-1,2,4-triazolato]platinum(II) (Pt(ptp){sub 2}) doped into 4,4'-bis(carbazol-9-yl)triphenylamine (CBP), and 1,3,5-tris(phenyl-2-benzimidazolyl)-benzene (TPBI) as the electron transport layer (ETL). Based on a comparison of these structures with devices that did not incorporate an electron/exciton blocker and devices featuring N,N'-dicarbazolyl-3,5-benzene (mCP) as the electron/exciton blocking layer, we ascribe the high efficiency and low efficiency roll-off to better charge balance, and enhanced confinement of excitons and the recombination zone to the emissive layer. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Optimal control

    CERN Document Server

    Aschepkov, Leonid T; Kim, Taekyun; Agarwal, Ravi P

    2016-01-01

    This book is based on lectures from a one-year course at the Far Eastern Federal University (Vladivostok, Russia) as well as on workshops on optimal control offered to students at various mathematical departments at the university level. The main themes of the theory of linear and nonlinear systems are considered, including the basic problem of establishing the necessary and sufficient conditions of optimal processes. In the first part of the course, the theory of linear control systems is constructed on the basis of the separation theorem and the concept of a reachability set. The authors prove the closure of a reachability set in the class of piecewise continuous controls, and the problems of controllability, observability, identification, performance and terminal control are also considered. The second part of the course is devoted to nonlinear control systems. Using the method of variations and the Lagrange multipliers rule of nonlinear problems, the authors prove the Pontryagin maximum principle for prob...

  4. Street light detection

    DEFF Research Database (Denmark)

    2017-01-01

    Disclosed is a method, a vehicle and a system for measuring light from one or more outdoor lamps on a road, the system comprising a number of light sensors configured to be arranged in a fixed position relative to a vehicle, where at least a first part of the light sensors is configured...... for measuring light from the one or more outdoor lamps, wherein at least a second part of the light sensors comprises at least two light sensors configured for detecting the angle which the light from the one or more outdoor lamps arrives at in the second part of the light sensors; a processing unit configured...... for calculating the position relative to the vehicle of the one or more outdoor lamps based on the detected angle which the light arrives in, and wherein the processing unit is configured for calculating the light on the road based on the light measured in the fixed position relative to the vehicle and based...

  5. Optimization of α-Fe{sub 2}O{sub 3}@Fe{sub 3}O{sub 4} incorporated N-TiO{sub 2} as super effective photocatalysts under visible light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, Mohamed Mokhtar, E-mail: mohmok2000@yahoo.com [Benha University, Faculty of Science, Chemistry Department, Benha (Egypt); Bayoumy, W.A. [Benha University, Faculty of Science, Chemistry Department, Benha (Egypt); Goher, M.E. [National Institute of Oceanography & Fisheries, Environmental Chemistry, Cairo (Egypt); Abdo, M.H., E-mail: mh_omr@yahoo.com [National Institute of Oceanography & Fisheries, Environmental Chemistry, Cairo (Egypt); Mansour El-Ashkar, T.Y. [National Institute of Oceanography & Fisheries, Environmental Chemistry, Cairo (Egypt)

    2017-08-01

    Highlights: • The α-Fe{sub 2}O{sub 3}/Fe{sub 3}O{sub 4} doped n-TiO{sub 2} was synthesized via deposition-self assembly technique. • The photocatalyst 1%α-Fe{sub 2}O{sub 3}/Fe{sub 3}O{sub 4}/n-TiO{sub 2} show a remarkable performance while MB degradation. • The strong interaction between α-Fe{sub 2}O{sub 3}/Fe{sub 3}O{sub 4} and n-TiO{sub 2} plays an important role. • It exhibits a unique textural, optical and charge transfer properties. - Abstract: Well dispersed α-Fe{sub 2}O{sub 3}@Fe{sub 3}O{sub 4} nanoparticles (7 nm) supported on mesoporous nitrogen doped titanium dioxide (N-TiO{sub 2}) are synthesized by deposition self-assembly route and their performances as photocatalysts toward methylene blue (MB) degradation are evaluated. The results illustrate that the spherical yolk-shell structure of α-Fe{sub 2}O{sub 3}@Fe{sub 3}O{sub 4}@N-TiO{sub 2} at the loading of 1%; of excellent S{sub BET} (187 m{sup 2} g{sup −1}) and pore volume (0.50 cm{sup 3} g{sup −1}), achieved high photocatalytic performance for the MB degradation (20 ppm, λ > 420 nm, lamp power = 160 W) under visible light illumination (k = 0.059 min{sup −1}). The influence of the interface formation between α-Fe{sub 2}O{sub 3}@Fe{sub 3}O{sub 4} and n-TiO{sub 2} affects severely the charges separation efficiency and enhances the electron transfer to keep on the existence of Fe{sup 3+}/Fe{sup 2+} moieties; those take significant role in the reaction mechanism. The existence of the latter junction is affirmed via XRD, TEM-SAED, Raman and FTIR techniques whereas, the photogenerated charges, their separation together with their transport and recombination rates are depicted via photoluminescence, electrical conductivity, incident photon to current efficiency (IPCE), cyclic voltammetry (CV) and impedance (EIS) measurements. The catalyst loading, zero point charge, pH variation, total organic carbon (TOC%) and the effect of lamps power are thoroughly investigated. The 1%α-Fe{sub 2}O{sub 3

  6. PFP Emergency Lighting Study

    International Nuclear Information System (INIS)

    BUSCH, M.S.

    2000-01-01

    NFPA 101, section 5-9 mandates that, where required by building classification, all designated emergency egress routes be provided with adequate emergency lighting in the event of a normal lighting outage. Emergency lighting is to be arranged so that egress routes are illuminated to an average of 1.0 footcandle with a minimum at any point of 0.1 footcandle, as measured at floor level. These levels are permitted to drop to 60% of their original value over the required 90 minute emergency lighting duration after a power outage. The Plutonium Finishing Plant (PFP) has two designations for battery powered egress lights ''Emergency Lights'' are those battery powered lights required by NFPA 101 to provide lighting along officially designated egress routes in those buildings meeting the correct occupancy requirements. Emergency Lights are maintained on a monthly basis by procedure ZSR-12N-001. ''Backup Lights'' are battery powered lights not required by NFPA, but installed in areas where additional light may be needed. The Backup Light locations were identified by PFP Safety and Engineering based on several factors. (1) General occupancy and type of work in the area. Areas occupied briefly during a shiftly surveillance do not require backup lighting while a room occupied fairly frequently or for significant lengths of time will need one or two Backup lights to provide general illumination of the egress points. (2) Complexity of the egress routes. Office spaces with a standard hallway/room configuration will not require Backup Lights while a large room with several subdivisions or irregularly placed rooms, doors, and equipment will require Backup Lights to make egress safer. (3) Reasonable balance between the safety benefits of additional lighting and the man-hours/exposure required for periodic light maintenance. In some plant areas such as building 236-Z, the additional maintenance time and risk of contamination do not warrant having Backup Lights installed in all rooms

  7. Distributed optimization system and method

    Science.gov (United States)

    Hurtado, John E.; Dohrmann, Clark R.; Robinett, III, Rush D.

    2003-06-10

    A search system and method for controlling multiple agents to optimize an objective using distributed sensing and cooperative control. The search agent can be one or more physical agents, such as a robot, and can be software agents for searching cyberspace. The objective can be: chemical sources, temperature sources, radiation sources, light sources, evaders, trespassers, explosive sources, time dependent sources, time independent sources, function surfaces, maximization points, minimization points, and optimal control of a system such as a communication system, an economy, a crane, and a multi-processor computer.

  8. Light Trapping with Silicon Light Funnel Arrays

    Directory of Open Access Journals (Sweden)

    Ashish Prajapati

    2018-03-01

    Full Text Available Silicon light funnels are three-dimensional subwavelength structures in the shape of inverted cones with respect to the incoming illumination. Light funnel (LF arrays can serve as efficient absorbing layers on account of their light trapping capabilities, which are associated with the presence of high-density complex Mie modes. Specifically, light funnel arrays exhibit broadband absorption enhancement of the solar spectrum. In the current study, we numerically explore the optical coupling between surface light funnel arrays and the underlying substrates. We show that the absorption in the LF array-substrate complex is higher than the absorption in LF arrays of the same height (~10% increase. This, we suggest, implies that a LF array serves as an efficient surface element that imparts additional momentum components to the impinging illumination, and hence optically excites the substrate by near-field light concentration, excitation of traveling guided modes in the substrate, and mode hybridization.

  9. Light as experiential material

    DEFF Research Database (Denmark)

    Petersen, Kjell Yngve; Søndergaard, Karin

    2013-01-01

    'Light as experiential material' is concerned with the development of a psychophysical method of investigation, by which the experience and design of architectural lighting can be approached in research and education......'Light as experiential material' is concerned with the development of a psychophysical method of investigation, by which the experience and design of architectural lighting can be approached in research and education...

  10. Light as experiential material

    DEFF Research Database (Denmark)

    Søndergaard, Karin; Petersen, Kjell Yngve

    2013-01-01

    'Light as experiential material' is concerned with the development of a psychophysical method of investigation, by which we can approach the experience and design of architectural lighting in research and education.......'Light as experiential material' is concerned with the development of a psychophysical method of investigation, by which we can approach the experience and design of architectural lighting in research and education....

  11. Pedestrian Friendly Outdoor Lighting

    Energy Technology Data Exchange (ETDEWEB)

    Miller, N. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Koltai, R. N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McGowan, T. K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-12-01

    The GATEWAY program followed two pedestrian-scale lighting projects that required multiple mockups – one at Stanford University in California and the other at Chautauqua Institution in upstate New York. The report provides insight into pedestrian lighting criteria, how they differ from street and area lighting criteria, and how solid-state lighting can be better applied in pedestrian applications.

  12. Lighting the Way to Mars

    Science.gov (United States)

    Barnwell, Payton L.

    2017-01-01

    Transforming the Martian atmosphere into something suitable for plant life would require a scientific feat that we currently do not possess the means to achieve, but indoor agriculture with LEDs could be just the alternative. Previous research has shown that light recipes provided by LEDs can alter the growth and nutrition of a plant based on wavelengths emitted, and crops grown in space aboard the International Space Station would respond similarly. By testing various LED light recipes such as ratios of red, green, blue (RGB) wavelengths, along with white (W) and far red (FR) on flight approved crops, harvest data were analyzed for trends to determine best light conditions for plant growth. Crops of Outredgeous Lettuce, Tokyo Bekana Chinese cabbage, and Mizuna were grown for 28 days with harvests on 14, 21, and 28 days after planting. By collecting fresh mass, shoot dimensions, chlorophyll estimates, leaf areanumber, and dry mass, the overall differences per light treatment were compared. For Outredgeous lettuce, a recipe of W+FR LEDs yielded increases in biomass and size compared to RB LEDs alone. However, the RB recipe resulted in smaller plants with higher concentrations in phytonutrients. Overall, the RGB + FR treatment with ratios similar to sunlight provided a promising balance of optimized biomass, size, and nutrient content. The Chinese cabbage, which was grown under various ratios of W and B light, showed no differences between recipes, and exhibited similar physiological responses regardless of the light recipes that were tested. The Mizuna studies are still ongoing. Crops for ISS chambers and astronaut consumption are targeted based on biomass, physiology, and for human psychological benefit. The goal of this research is to provide light recipe recommendations for space crops that have been thoroughly tested on the ground. These results will serve a major benefit for astronauts growing crops in the Advanced Plant Habitat currently in orbit aboard the

  13. Light Rhythms in Architecture

    DEFF Research Database (Denmark)

    Bülow, Katja

    2013-01-01

    On one hand, urban lighting expresses itself in a complex visual environment made by the interplay by between many separate lighting schemes, as street lighting, shop lighting, luminous commercials etc. On the other, a noticeable order of patterns occurs, when lighting is observed as luminous...... formation and rhythm. When integrated into an architectural concept, electrical lighting non-intended for poetic composition has the ability to contribute to place, time, and function-telling aspects of places in urban contexts. Urban environments are information wise challenging to pre-historic human...... instincts, but they can be met by careful selection and adjustment of existing light situations....

  14. Next Generation Light Robotics

    DEFF Research Database (Denmark)

    Glückstad, Jesper

    Light Robotics is a new field of research where ingredients from photonics, nanotechnology and biotechnology are put together in new ways to realize light-driven robotics at the smallest scales to solve major challenges primarily within the nanobio-domain but not limited hereto. Exploring the full...... potential of this new ‘drone-like’ light-printed, light-driven, light-actuated micro- and nano-robotics in challenging geometries requires a versatile and real-time reconfigurable light addressing that can dynamically track a plurality of tiny tools in 3D to ensure real-time continuous light...

  15. Concept of white light in stage lighting

    Science.gov (United States)

    Rinaldi, Mauricio R.

    2002-06-01

    In perceiving objects, generally we see them in a white light situation. But, actually, there is not an absolute white, in such a manner that the different light sources have a determined kind of white, what it is known as color temperature. Even the white light may be of different kinds (different color temperature), the individual mind tends to perceive it as the same kind of white, that is to say, there is in our mind a psychological function by which we operate an integration in the perception in order to do the object perceptually invariable. On the other hand, it is a common practice in stage lighting to use color light sources. It is a well known phenomenon that a color of light produces a change in the object color perception. However, when we go to theater, we see the objects as having their real color, even if the lighting is not white. In this paper the concept of white light in stage lighting is presented, showing its possibilities of aesthetical expression.

  16. Discrete optimization

    CERN Document Server

    Parker, R Gary

    1988-01-01

    This book treats the fundamental issues and algorithmic strategies emerging as the core of the discipline of discrete optimization in a comprehensive and rigorous fashion. Following an introductory chapter on computational complexity, the basic algorithmic results for the two major models of polynomial algorithms are introduced--models using matroids and linear programming. Further chapters treat the major non-polynomial algorithms: branch-and-bound and cutting planes. The text concludes with a chapter on heuristic algorithms.Several appendixes are included which review the fundamental ideas o

  17. Light and colours

    DEFF Research Database (Denmark)

    Volf, Carlo

    2011-01-01

    Often a dichotomy between daylight and artificial light is observed, often artificial lighting replaces daylight. In Denmark daylight is characterized partly by being "borrowed" half of the year, partly by having long transitions periods between the light and the dark (nautical and civil twilight......). For these reasons artificial lighting does not complement daylight but provides, coupled with the daylight, the total lighting in the indoor environment. Electric lighting is therefore ‐ in a complex interaction with the daylight ‐ of great importance for both our lighting and our wellbeing. Studying artificial...... lighting without studying daylight seem to be a common procedure of the practice of today in Denmark and other parts of the industrialized world. As a consequence of this artificial lighting suffers from a quantifying tyranny, a tyranny where the quality of light is measured in quantities. This procedure...

  18. Leaf phenotypic variation and developmental instability in relation to different light regimes

    Directory of Open Access Journals (Sweden)

    Henrique Venâncio

    2016-06-01

    Full Text Available ABSTRACT For pioneer plants, shaded habitats represent a stressful condition, where sunlight exposure is below the optimum level and so leaves expand in order to intercept a greater amount of light. We investigated changes in both phenotypic variation and stress of Bauhinia brevipes in sunny and shaded microhabitats. Leaf area was used as a measure of phenotypic variation, whereas leaf asymmetry (difference between right and left sides of leaves, was used as a measure of stress. We hypothesized an increase in leaf area and stress in shaded locations, which might indicate that B. brevipes was compensating for low light absorption, and elevated levels of stress, respectively. Plants in the sun fitted a fluctuating asymmetry pattern (normal distribution of right minus left sides, while shaded plants were clearly antisymmetric (bimodal distribution of leaf side differences. Leaf asymmetry and area were 5% and 26.8% higher in plants in the shade compared to plants in the sun, respectively. These results were expected since B. brevipes is found predominantly in open areas; so sunlight exposure is important for its development. The presence of antisymmetry is rare in studies of developmental instability, and here it might indicate higher stress compared to plants with fluctuating asymmetry.

  19. Free-space data transfer using the spatial modes of light

    CSIR Research Space (South Africa)

    Gailele, Lucas M

    2016-07-01

    Full Text Available The orbital angular momentum (OAM) of light has become the focus of intensive research. Traditional optical communication systems optimize multiplexing in the polarization and the wavelength of light to attain an increase in bandwith. However we...

  20. Supplementary light and higher fertigation EC in the cultivation of bromelia improve quality and accelerate growth

    NARCIS (Netherlands)

    Garcia Victoria, N.; Warmenhoven, M.G.

    2012-01-01

    Abstract: In order to provide Bromelia growers with lacking information about optimal levels of supplementary light and nutrient EC, two consecutive greenhouse experiments were conducted by Wageningen UR Glasshouse Horticulture in Bleiswijk (The Netherlands). In the first experiment a light

  1. An organic white light-emitting dye: very small molecular architecture displays panchromatic emission.

    Science.gov (United States)

    Nandhikonda, Premchendar; Heagy, Michael D

    2010-11-14

    The synthesis and photophysical characterization of a new white-light fluorophore is described. The optimization of excitation wavelengths allows the naphthalimide (NI) dyes to display blue, green or white light emission depending on the excitation wavelength.

  2. Understanding energy efficient lighting as an outcome of dynamics of social practices

    DEFF Research Database (Denmark)

    Jensen, Charlotte Louise

    2017-01-01

    In policy-making, reducing energy consumption from lighting is largely treated as a matter of optimizing products. However, since lighting is a highly cultural and socio-material phenomenon, this article argues that current ways of using light cannot be attributed to the properties of the light s...

  3. Numerical Optimization Using Desktop Computers

    Science.gov (United States)

    1980-09-11

    geophysical, optical and economic analysis to compute a life-cycle cost for a design with a stated energy capacity. NISCO stands for NonImaging ...more efficiently by nonimaging optical systems than by conventional image forming systems. The methodology of designing optimized ronimaging systems...compound parabolic concentrating iWelford, W. T. and Winston, R., The Optics of Nonimaging Concentrators, Light and Solar Energy, p. ix, Academic

  4. LightSavers : accelerating advanced outdoor lighting

    Energy Technology Data Exchange (ETDEWEB)

    Purcell, B.; Pickering, M.

    2010-01-15

    This paper provided an update to the Toronto Atmospheric Fund (TAF) LightSavers program. The program was designed to accelerate market transformation for light emitting diode (LED) and advanced lighting management systems in outdoor lighting applications. It is expected that the program will result in significant electricity savings and emissions reductions within the Greater Toronto Area (GTA) and other Ontario municipalities. The first phase of the program established advanced outdoor lighting pilot programs in parking lots, garages, and pathway lighting applications that were guided by a common monitoring protocol to ensure useful and reliable assessment of the pilot programs. The TAF has since developed a strategy to strengthen public understanding and support for the use of advanced lighting, and continues to address policy issues that may impact the future of LED lighting programs. The TAF has also activated an electronic newsletter, delivered public workshops, and has been represented at several conferences. A working partnership has been established with Toronto Hydro Energy Services. Five pilot sites have been installed and have begun to provide monitoring data. Details of the pilot programs were provided. 16 figs.

  5. Fabrication of organic light emitting diode using Molybdenum ...

    Indian Academy of Sciences (India)

    65

    out by measuring sheet resistance, optical transmittance and surface ... role in the organic light-emitting diode (OLED) performance because it determines the .... coated glass by thermal vacuum deposition method and optimize it by using ...

  6. Quantifying light pollution

    International Nuclear Information System (INIS)

    Cinzano, P.; Falchi, F.

    2014-01-01

    In this paper we review new available indicators useful to quantify and monitor light pollution, defined as the alteration of the natural quantity of light in the night environment due to introduction of manmade light. With the introduction of recent radiative transfer methods for the computation of light pollution propagation, several new indicators become available. These indicators represent a primary step in light pollution quantification, beyond the bare evaluation of the night sky brightness, which is an observational effect integrated along the line of sight and thus lacking the three-dimensional information. - Highlights: • We review new available indicators useful to quantify and monitor light pollution. • These indicators are a primary step in light pollution quantification. • These indicators allow to improve light pollution mapping from a 2D to a 3D grid. • These indicators allow carrying out a tomography of light pollution. • We show an application of this technique to an Italian region

  7. LIGHT-WEIGHT LOAD-BEARING STRUCTURE

    DEFF Research Database (Denmark)

    2009-01-01

    The invention relates to a light-weight load-bearing structure (1) with optimized compression zone (2), where along one or more compression zones (2) in the structure (1) to be cast a core (3) of strong concrete is provided, which core (3) is surrounded by concrete of less strength (4) compared...... to the core (3) of strong concrete. The invention also relates to a method of casting of light-weight load-bearing structures (1) with optimized compression zone (2) where one or more channels, grooves, ducts, pipes and/or hoses (5) formed in the load-bearing structure (1) serves as moulds for moulding one...... or more cores (3) of strong concrete in the light-weight load-bearing structure (1)....

  8. Intelligent control of dynamic LED lighting; Intelligent styring af dynamisk LED belysning. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Thorseth, A.; Corell, D.; Hansen, Soeren S.; Dam-Hansen, C.; Petersen, Paul Michael

    2013-01-15

    The project has resulted in a prototype of a new intelligent lighting control system. The control system enables the end user to control his or her own local lighting environment (lighting zone) according to individual preferences and needs. The report provides a description of how the developed intelligent lighting system is composed and functions. The system is designed as a work lamp that enables dynamic change of the light color scheme according to a number of light control algorithms. It is specifically designed in relation to user tests of the intelligent lighting system, which is carried out in the final part of the project. An intelligent and advanced control of LED lighting was developed, which enables optimization of the user's light conditions in a given situation. Based on a number of known parameters, the system can control lighting so that at any time optimal light conditions are created, using a minimum of electric power. (LN)

  9. The design of lighting

    CERN Document Server

    Tregenza, Peter

    2013-01-01

    This fully updated edition of the successful book The Design of Lighting, provides the lighting knowledge needed by the architect in practice, the interior designer and students of both disciplines. The new edition offers a clear structure, carefully selected material and linking of lighting with other subjects, in order to provide the reader with a comprehensive and specifically architectural approach to lighting. Features of this new edition include:technical knowledge of lighting in the context of architectural design;an emphasis on imagination in architectural light and presentation of the

  10. Lamps and lighting

    CERN Document Server

    Cayless, MA; Marsden, A M

    2012-01-01

    This book is a comprehensive guide to the theory and practice of lighting. Covering the physics of light production, light sources, circuits and a wide variety of lighting applications, it is both suitable as a detailed textbook and as thoroughly practical guide for practising lighting engineers. This fourth edition of Lamps and Lighting has been completely updated with new chapters on the latest lamp technology and applications. The editors ahve called upon a wide range of expertise and as a result many sections have been broadened to include both European and US practice.The book begins with

  11. Photovoltaic OLED Driver for Low-Power Stand-Alone Light-to-Light Systems

    DEFF Research Database (Denmark)

    Ploug, Rasmus Overgaard; Knott, Arnold

    2016-01-01

    of a three-port-converter for this purpose optimized for the specifications for driving an Organic Light Emitting Diode (OLED) panel intended for lighting purposes. By using a three-port-converter, featuring shared components for each conversion mode, the converter reaches 97 % efficiency at 1.8 W during...... conversion from photovoltaic panel to the battery, and 97 % in the area 1.4 W to 2 W for power delivery to the OLED....

  12. [SIAM conference on optimization

    Energy Technology Data Exchange (ETDEWEB)

    1992-05-10

    Abstracts are presented of 63 papers on the following topics: large-scale optimization, interior-point methods, algorithms for optimization, problems in control, network optimization methods, and parallel algorithms for optimization problems.

  13. In a Heartbeat: Light and Cardiovascular Physiology

    Directory of Open Access Journals (Sweden)

    Sarah L. Chellappa

    2017-10-01

    Full Text Available Light impinging on the retina fulfils a dual function: it serves for vision and it is required for proper entrainment of the endogenous circadian timing system to the 24-h day, thus influencing behaviors that promote health and optimal quality of life but are independent of image formation. The circadian pacemaker located in the suprachiasmatic nuclei modulates the cardiovascular system with an intrinsic ability to anticipate morning solar time and with a circadian nature of adverse cardiovascular events. Here, we infer that light exposure might affect cardiovascular function and provide evidence from existing research. Findings show a time-of-day dependent increase in relative sympathetic tone associated with bright light in the morning but not in the evening hours. Furthermore, dynamic light in the early morning hours can reduce the deleterious sleep-to-wake evoked transition on cardiac modulation. On the contrary, effects of numerous light parameters, such as illuminance level and wavelength of monochromatic light, on cardiac function are mixed. Therefore, in future research studies, light modalities, such as timing, duration, and its wavelength composition, should be taken in to account when testing the potential of light as a non-invasive countermeasure for adverse cardiovascular events.

  14. Advanced Light Source (ALS)

    Data.gov (United States)

    Federal Laboratory Consortium — The Advanced Light Source (ALS), a world leader in soft x-ray science, generates light in the wavelengths needed for examining the atomic and electronic structure of...

  15. Lighting detectives forum

    DEFF Research Database (Denmark)

    Bülow, Katja; Skindbjerg Kristensen, Lisbeth

    2003-01-01

    Belysning for boligområder var emnet for lighting detectives forum, der blev afholdt i Stockholm i august 2003.......Belysning for boligområder var emnet for lighting detectives forum, der blev afholdt i Stockholm i august 2003....

  16. GPC Light Shaper

    DEFF Research Database (Denmark)

    Bañas, Andrew Rafael; Raaby, Peter; Glückstad, Jesper

    Generalized Phase Contrast is a disruptive light sculpting technology for studying brain functionalities via light-activated neuron control. GPC dynamically reshapes conventional or multiwavelength lasers for precise and efficient neuron targeting. GPC also makes existing laser systems much more...

  17. Spectrally tunable lighting facility

    Data.gov (United States)

    Federal Laboratory Consortium — Solid-state lighting (SSL) is increasingly being introduced into the market and it is expected that many of the light sources currently used for general illumination...

  18. Light Imaging Section

    Data.gov (United States)

    Federal Laboratory Consortium — The mission of the Light Imaging Section is to give NIAMS scientists access to state-of-the-art light imaging equipment and to offer training and assistance at all...

  19. Light Pollution | CTIO

    Science.gov (United States)

    Preserving the Dark Skies La Oficina de Protección de la Calidad del Cielo del Norte de Chile - OPCC Light ‹› You are here CTIO Home » Outreach » NOAO-S EPO Programs » Dark Sky Education » Light Pollution Light Pollution Preserving Dark Skies: Efforts to measure light pollution and work with the local

  20. OLED displays and lighting

    CERN Document Server

    Koden, Mitsuhiro

    2017-01-01

    Organic light-emitting diodes (OLEDs) have emerged as the leading technology for the new display and lighting market. OLEDs are solid-state devices composed of thin films of organic molecules that create light with the application of electricity. OLEDs can provide brighter, crisper displays on electronic devices and use less power than conventional light-emitting diodes (LEDs) or liquid crystal displays (LCDs) used today. This book covers both the fundamentals and practical applications of flat and flexible OLEDs.

  1. The landscape lighting book

    CERN Document Server

    Moyer, Janet Lennox

    2013-01-01

    This richly illustrated, up-to-date guide offers practical coverage of all aspects of lighting design. Written by an award-winning, internationally known lighting designer, it covers lighting practices, materials, and their design applications and offers guidelines for preparing lighting drawings, control and transfer charts, symbol lists, and other technical specifications. This edition provides a new focus on the use of LEDs, as well as new and expanded coverage of renderings, Mesopic Vision, and the latest controls approaches and systems.

  2. Hyperspectral microscopy to identify foodborne bacteria with optimum lighting source

    Science.gov (United States)

    Hyperspectral microscopy is an emerging technology for rapid detection of foodborne pathogenic bacteria. Since scattering spectral signatures from hyperspectral microscopic images (HMI) vary with lighting sources, it is important to select optimal lights. The objective of this study is to compare t...

  3. Microhabitats utilisés par les alevins 0+ d'une communauté de cyprins rhéophiles : analyse de l'évolution de la communauté et des densités de population

    Directory of Open Access Journals (Sweden)

    BARAS E.

    1995-04-01

    Full Text Available L'évolution de l'occupation des microhabitats par les alevins de la communauté de cyprins rhéophiles de l'Ourthe a été étudiée au cours de l'été et de l'automne 1994 par échantillonnage ponctuel d'abondance (électrodes fixes prépositionnées, courant continu. 16155 poissons (10-75 mm appartenant à 15 espèces ont été recensés sur 78 sites d'échantillonnage de 2 m2 . Les espèces les plus représentées étaient Leuciscus cephalus, Leuciscus leuciscus et Chondrostoma nasus (respectivement 43,6 %, 20,7 % et 16,7 % des captures estivales. L'analyse factorielle des correspondances d'une matrice site x (espèce x taille met en évidence une subdivision progressive de la communauté au cours de l'été en espèces d'eau vive (B. barbus et L. leuciscus et d'eau lente, davantage associées à un couvert végétal (L. cephalus et C. nasus. La densité maximale observée (fin juin est de 1500 alevins (25 mm m-2, correspondant à une biomasse de 250 g m-2. Le modèle explicatif de la densité généré par analyse de régression multiple pas-à-pas explique 60,0 % de la variabilité de la densité par les variables vitesse de courant, température de l'eau et date d'échantillonnage, cette variable intégrant le concept de mortalité-dispersion au cours de la saison de croissance. Les implications de la méthodologie et des résultats présentés au plan de la gestion des écosystèmes lotiques sont brièvement discutés.

  4. WRITING LIGHT VERSE.

    Science.gov (United States)

    ARMOUR, RICHARD

    VARIOUS ASPECTS OF WRITING LIGHT VERSE, EITHER FOR FUN OR FOR PUBLICATION, ARE DISCUSSED IN THIS BOOK--(1) THE NATURE AND APPEAL OF LIGHT VERSE AND ITS MANY VARIETIES, (2) SUBJECTS WHICH LEND THEMSELVES BEST TO THE LIGHT-VERSE TREATMENT, (3) THE APPLICATION OF WHAT ONE HAS LEARNED FROM READING, THINKING, AND CLOSELY OBSERVING HUMAN FOIBLES, (4)…

  5. Light pollution : working paper

    NARCIS (Netherlands)

    Lechner, Stefan; Arns, Marieke

    2013-01-01

    Light pollution is one of the fastest growing and most pervasive of environmental pollution (Chepesiuk, 2009). In the last couple of years, a lot of research has been done about the effects of light pollution. The interest in light pollution has been growing in many fields of science, extending from

  6. Simulating Supernova Light Curves

    International Nuclear Information System (INIS)

    Even, Wesley Paul; Dolence, Joshua C.

    2016-01-01

    This report discusses supernova light simulations. A brief review of supernovae, basics of supernova light curves, simulation tools used at LANL, and supernova results are included. Further, it happens that many of the same methods used to generate simulated supernova light curves can also be used to model the emission from fireballs generated by explosions in the earth's atmosphere.

  7. Simulating Supernova Light Curves

    Energy Technology Data Exchange (ETDEWEB)

    Even, Wesley Paul [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dolence, Joshua C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-05

    This report discusses supernova light simulations. A brief review of supernovae, basics of supernova light curves, simulation tools used at LANL, and supernova results are included. Further, it happens that many of the same methods used to generate simulated supernova light curves can also be used to model the emission from fireballs generated by explosions in the earth’s atmosphere.

  8. Plants under continuous light

    NARCIS (Netherlands)

    Velez Ramirez, A.I.; Ieperen, van W.; Vreugdenhill, D.; Millenaar, F.F.

    2011-01-01

    Continuous light is an essential tool for understanding the plant circadian clock. Additionally, continuous light might increase greenhouse food production. However, using continuous light in research and practice has its challenges. For instance, most of the circadian clock-oriented experiments

  9. Intelligent street lighting clustering

    NARCIS (Netherlands)

    Verhoeven, R.; Jovanovic, N.; Lukkien, J.J.

    2014-01-01

    The advances in dynamic street lighting introduce new functionality for control and maintenance of the street lighting infrastructure. Vital elements in this infrastructure are the powerful controlling devices that control separate groups of light poles and collect information from the system. For

  10. Light-Driven Alignment

    CERN Document Server

    Antonyuk, Boris P

    2009-01-01

    This book deals with influencing the properties of solids by light-driven electron transport. The theoretical basis of these effects, light-driven ordering and self-organisation, as well as optical motors are presented. With light as a tool, new ways to produce materials are opened.

  11. Architectural Physics: Lighting.

    Science.gov (United States)

    Hopkinson, R. G.

    The author coordinates the many diverse branches of knowledge which have dealt with the field of lighting--physiology, psychology, engineering, physics, and architectural design. Part I, "The Elements of Architectural Physics", discusses the physiological aspects of lighting, visual performance, lighting design, calculations and measurements of…

  12. Topology optimization of nano-photonic systems

    DEFF Research Database (Denmark)

    Elesin, Yuriy; Wang, Fengwen; Andkjær, Jacob Anders

    2012-01-01

    We describe recent developments within nano-photonic systems design based on topology optimization. Applications include linear and non-linear optical waveguides, slow-light waveguides, as well as all-dielectric cloaks that minimize scattering or back-scattering from hard obstacles.......We describe recent developments within nano-photonic systems design based on topology optimization. Applications include linear and non-linear optical waveguides, slow-light waveguides, as well as all-dielectric cloaks that minimize scattering or back-scattering from hard obstacles....

  13. The Effect of Anisotropy on Light Extraction of Organic Light-Emitting Diodes with Photonic Crystal Structure

    Directory of Open Access Journals (Sweden)

    Wei Xu

    2013-01-01

    Full Text Available The light extraction efficiency of organic light-emitting diodes (OLED is greatly limited due to the difference in refractive indexes between materials of OLED. We fabricated OLED with photonic crystal microstructures in the interface between the glass substrate and the ITO anode. The light extraction efficiency can be improved by utilizing photonic crystals; however, the anisotropy effect of light extraction was clearly observed in experiment. To optimize the device performance, the effect of photonic crystal on both light extraction and angular distribution was investigated using finite-difference time domain (FDTD method. We simulated the photonic crystals with the structure of square lattice and triangle lattice. We analyzed the improvement of these structures in the light extraction efficiency of the OLED and the influence of arrangement, depth, period, and diameter on anisotropy. The optimized geometric parameters were provided, which will provide the theoretical support for designing the high performance OLED.

  14. Electron beam spectrum monitor using synchrotron light

    International Nuclear Information System (INIS)

    Reagan, D.; Hostetler, T.E.

    1979-03-01

    This instrument shows the positions, widths, and shapes of momentum spectra of SLAC beams. It uses synchrotron light produced when the beam is deflected by a magnet. Some of the light is focused on the face of an image splitter consisting of acrylic light pipes. The light pipes illuminate twelve photomultiplier tubes. Pulses from the PM tubes are integrated, multiplexed, and displayed on an oscilloscope. The resolution of the instrument is usually better than 0.2%. It has some advantages over the secondary emitter foil spectrum monitors (SEM's) currently in use at SLAC. It need never be put out of service to avoid disturbing the beam. It is as sensitive as the most sensitive SLAC SEM. (Its performance has been optimized for high-current beams; it can easily be made much more sensitive.) It provides information on a pulse-to-pulse basis and, with better cables, could indicate electron beam pulse shapes

  15. White light emission from engineered silicon carbide

    DEFF Research Database (Denmark)

    Ou, Haiyan

    Silicon carbide (SiC) is a wide indirect bandgap semiconductor. The light emission efficiency is low in nature. But this material has very unique physical properties like good thermal conductivity, high break down field etc in addition to its abundance. Therefore it is interesting to engineer its...... light emission property so that to take fully potential applications of this material. In this talk, two methods, i.e. doping SiC heavily by donor-acceptor pairs and making SiC porous are introduced to make light emission from SiC. By co-doping SiC with nitrogen and boron heavily, strong yellow emission...... is demonstrated. After optimizing the passivation conditions, strong blue-green emission from porous SiC is demonstrated as well. When combining the yellow emission from co-doped SiC and blue-green from porous SiC, a high color rendering index white light source is achieved....

  16. Light history modulates antioxidant and photosynthetic responses of biofilms to both natural (light) and chemical (herbicides) stressors.

    Science.gov (United States)

    Bonnineau, Chloé; Sague, Irene Gallardo; Urrea, Gemma; Guasch, Helena

    2012-05-01

    In multiple stress situations, the co-occurrence of environmental and chemical factors can influence organisms' ability to cope with toxicity. In this context, the influence of light adaptation on the response of freshwater biofilms to sudden light changes or to herbicides exposure was investigated by determining various parameters: diatom community composition, photosynthetic parameters, chlorophyll a content, antioxidant enzyme activities. Biofilms were grown in microcosms under sub-optimal, saturating, and high light intensities and showed already described characteristics of shade/light adaptation (community structure, photosynthetic adaptation, etc.). Light history modulated antioxidant and photosynthetic responses of biofilms to the stress caused by short-term exposure to sudden light changes or to herbicides. First biofilms adapted to sub-optimal light intensity (shade-adapted) were found to be more sensitive to an increase in light intensity than high-light adapted ones to a reduction in light intensity. Second, while light history influenced biofilms' response to glyphosate, it had little influence on biofilms' response to copper and none on its response to oxyfluorfen. Indeed glyphosate exposure led to a stronger decrease in photosynthetic efficiency of shade-adapted biofilms (EC(50) = 11.7 mg L(-1)) than of high-light adapted communities (EC(50) = 35.6 mg L(-1)). Copper exposure led to an activation of ascorbate peroxidase (APX) in biofilms adapted to sub-optimal and saturating light intensity while the protein content decreased in all biofilms exposed to copper. Oxyfluorfen toxicity was independent of light history provoking an increase in APX activity. In conclusion this study showed that both previous exposure to contaminants and physical habitat characteristics might influence community tolerance to disturbances strongly.

  17. Azimuthal anisotropy of light extraction from photonic crystal light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Chun-Feng; Lu, T.C.; Wang, S.C. [Department of Photonics and Institute of Electro-Optical Engineering, National Chiao-Tung University, Hsinchu 300, Taiwan (China); Chao, C.H.; Hsueh, H.T.; Wang, J.F.T.; Yeh, W.Y.; Chi, J.Y. [Electronics and Optoelectronics Research Laboratories, Industrial Technology Research Institute, Hsinchu 310, Taiwan (China); Kuo, H.C.

    2008-07-01

    Photonic crystal (PhC) light-emitting diodes (LEDs) exhibiting anisotropic light extraction have been investigated experimentally and theoretically. It is found that the anisotropic light extraction strongly depends on the lattice constant and orientation. Optical images of the anisotropy in the azimuthal direction are obtained using annular structure with triangular lattice. 6-fold symmetric light extraction patterns with varying number of petals are observed. More petals in multiple of 6 appear in the observed image with lattice constant increasing. This anisotropic behavior suggests a new means to optimize the PhC design of GaN LED for light extraction. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Photonic crystal light source

    Science.gov (United States)

    Fleming, James G [Albuquerque, NM; Lin, Shawn-Yu [Albuquerque, NM; Bur, James A [Corrales, NM

    2004-07-27

    A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.

  19. Traffic Light Options

    DEFF Research Database (Denmark)

    Jørgensen, Peter Løchte

    This paper introduces, prices, and analyzes traffic light options. The traffic light option is an innovative structured OTC derivative developed independently by several London-based investment banks to suit the needs of Danish life and pension (L&P) companies, which must comply with the traffic...... 2006, and supervisory authorities in many other European countries have implemented similar regulation. Traffic light options are therefore likely to attract the attention of a wider audience of pension fund managers in the future. Focusing on the valuation of the traffic light option we set up a Black...... light scenarios. These stress scenarios entail drops in interest rates as well as in stock prices, and traffic light options are thus designed to pay off and preserve sufficient capital when interest rates and stock prices fall simultaneously. Sweden's FSA implemented a traffic light system in January...

  20. Traffic Light Options

    DEFF Research Database (Denmark)

    Jørgensen, Peter Løchte

    2007-01-01

    This paper introduces, prices, and analyzes traffic light options. The traffic light option is an innovative structured OTC derivative developed independently by several London-based investment banks to suit the needs of Danish life and pension (L&P) companies, which must comply with the traffic...... 2006, and supervisory authorities in many other European countries have implemented similar regulation. Traffic light options are therefore likely to attract the attention of a wider audience of pension fund managers in the future. Focusing on the valuation of the traffic light option we set up a Black...... light scenarios. These stress scenarios entail drops in interest rates as well as in stock prices, and traffic light options are thus designed to pay off and preserve sufficient capital when interest rates and stock prices fall simultaneously. Sweden's FSA implemented a traffic light system in January...

  1. A study of optical design and optimization of laser optics

    Science.gov (United States)

    Tsai, C.-M.; Fang, Yi-Chin

    2013-09-01

    This paper propose a study of optical design of laser beam shaping optics with aspheric surface and application of genetic algorithm (GA) to find the optimal results. Nd: YAG 355 waveband laser flat-top optical system, this study employed the Light tools LDS (least damped square) and the GA of artificial intelligence optimization method to determine the optimal aspheric coefficient and obtain the optimal solution. This study applied the aspheric lens with GA for the flattening of laser beams using collimated laser beam light, aspheric lenses in order to achieve best results.

  2. Shaping both Light & Material for Optimal Light‐Matter Interaction

    DEFF Research Database (Denmark)

    Glückstad, Jesper

    that can be equipped with optical trapping handles for convenient opto‐mechanical control using only optical forces. Such microstructures ‐ as illustrated above ‐ can be effectively handled with simultaneous top‐ and side‐view on our proprietary BioPhotonics Workstation (BWS) to undertake six......‐degree‐of‐freedom optical actuation of tiny 3D‐printed tip‐structures easily entering the submicron‐regime. Aided by our international collaborators who fabricated test structures for us, we were able to put our pioneering concept of optically steerable freestanding waveguides – coined: wave‐guided optical waveguides...

  3. Optimization of traffic light control system of an intersection using ...

    African Journals Online (AJOL)

    This paper considers an automated static road traffic control system of an intersection for the purpose of minimizing the effects of traffic jam and hence its attendant consequences such as prolonged waiting time, emission of toxic hydrocarbons from automobiles, etc. Using real-time road traffic data, a dynamic round-robin ...

  4. Optimization of Traffic Light Control System of an Intersection Using

    African Journals Online (AJOL)

    Nwokem et al.

    created for road transport system, they have far less capacity to contain the number of vehicles being .... (such as fuzzy logic, artificial neural networks, genetic/evolutionary computing, and swarm intelligence) have been found to be more cost ...

  5. Optimal linear precoding for indoor visible light communication system

    KAUST Repository

    Sifaou, Houssem; Park, Kihong; Kammoun, Abla; Alouini, Mohamed-Slim

    2017-01-01

    ) problem. The performance of the proposed precoding scheme is studied under different working conditions and compared with the classical zero-forcing precoding. Simulations have been provided to illustrate the high gain of the proposed scheme.

  6. Internal heat gain from different light sources in the building lighting systems

    Directory of Open Access Journals (Sweden)

    Suszanowicz Dariusz

    2017-01-01

    Full Text Available EU directives and the Construction Law have for some time required investors to report the energy consumption of buildings, and this has indeed caused low energy consumption buildings to proliferate. Of particular interest, internal heat gains from installed lighting affect the final energy consumption for heating of both public and residential buildings. This article presents the results of analyses of the electricity consumption and the luminous flux and the heat flux emitted by different types of light sources used in buildings. Incandescent light, halogen, compact fluorescent bulbs, and LED bulbs from various manufacturers were individually placed in a closed and isolated chamber, and the parameters for their functioning under identical conditions were recorded. The heat flux emitted by 1 W nominal power of each light source was determined. Based on the study results, the empirical coefficients of heat emission and energy efficiency ratios for different types of lighting sources (dependent lamp power and the light output were designated. In the heat balance of the building, the designated rates allow for precise determination of the internal heat gains coming from lighting systems using various light sources and also enable optimization of lighting systems of buildings that are used in different ways.

  7. Internal heat gain from different light sources in the building lighting systems

    Science.gov (United States)

    Suszanowicz, Dariusz

    2017-10-01

    EU directives and the Construction Law have for some time required investors to report the energy consumption of buildings, and this has indeed caused low energy consumption buildings to proliferate. Of particular interest, internal heat gains from installed lighting affect the final energy consumption for heating of both public and residential buildings. This article presents the results of analyses of the electricity consumption and the luminous flux and the heat flux emitted by different types of light sources used in buildings. Incandescent light, halogen, compact fluorescent bulbs, and LED bulbs from various manufacturers were individually placed in a closed and isolated chamber, and the parameters for their functioning under identical conditions were recorded. The heat flux emitted by 1 W nominal power of each light source was determined. Based on the study results, the empirical coefficients of heat emission and energy efficiency ratios for different types of lighting sources (dependent lamp power and the light output) were designated. In the heat balance of the building, the designated rates allow for precise determination of the internal heat gains coming from lighting systems using various light sources and also enable optimization of lighting systems of buildings that are used in different ways.

  8. Coral photobiology: new light on old views.

    Science.gov (United States)

    Iluz, David; Dubinsky, Zvy

    2015-04-01

    The relationship between reef-building corals and light-harvesting pigments of zooxanthellae (Symbiodinium sp.) has been acknowledged for decades. The photosynthetic activity of the algal endocellular symbionts may provide up to 90% of the energy needed for the coral holobiont. This relationship limits the bathymetric distribution of coral reefs to the upper 100 m of tropical shorelines. However, even corals growing under high light intensities have to supplement the photosynthates translocated from the algae by predation on nutrient-rich zooplankton. New information has revealed how the fate of carbon acquired through photosynthesis differs from that secured by predation, whose rates are controlled by light-induced tentacular extension. The Goreau paradigm of "light-enhanced calcification" is being reevaluated, based on evidence that blue light stimulates coral calcification independently from photosynthesis rates. Furthermore, under dim light, calcification rates were stoichiometrically uncoupled from photosynthesis. The rates of photosynthesis of the zooxanthellae exhibit a clear endogenous rhythmicity maintained by light patterns. This daily pattern is concomitant with a periodicity of all the antioxidant protective mechanisms that wax and wane to meet the concomitant fluctuation in oxygen evolution. The phases of the moon are involved in the triggering of coral reproduction and control the spectacular annual mass-spawning events taking place in several reefs. The intensity and directionality of the underwater light field affect the architecture of coral colonies, leading to an optimization of the exposure of the zooxanthellae to light. We present a summary of major gaps in our understanding of the relationship between light and corals as a roadmap for future research. Copyright © 2014 Elsevier GmbH. All rights reserved.

  9. Studying Light Color using White LED Lighting

    Science.gov (United States)

    Yamagishi, Misako; Yamaba, Kazuo; Nagata, Manori; Kubo, Chiho; Nokura, Kunihiro

    Recently, white Light Emitting Diodes (LEDs) are receiving attention worldwide as new lighting devices. This study examined effects of a lighting application on performance using white LEDs. The light color—the correlated color temperature (CCT) —was assessed. It affected to psychological states and physiological conditions. Three CCT conditions were respectively set for the experiment: 2500 K, 5000 K, and 8200 K. In all, 20 younger subjects (20-30 years old), 15 middle-aged to elderly subjects (45-60 years old) and 12 elderly subjects (over 65 years-old) participated. They were presented a Numerical Verification (NV) task for performance measurement. The psychological states on performance were evaluated using the lighting assessment questionnaire. The physiological conditions were recorded using an electrocardiograph. Results show that the effects of CCT differ among age groups. Especially, the performance of younger subjects might differ from CCT conditions; elderly subjects are affected by CCT condition because of their visual acuity or response to contrast of objects.

  10. Fourth Light at Paranal!

    Science.gov (United States)

    2000-09-01

    VLT YEPUN Joins ANTU, KUEYEN and MELIPAL It was a historical moment last night (September 3 - 4, 2000) in the VLT Control Room at the Paranal Observatory , after nearly 15 years of hard work. Finally, four teams of astronomers and engineers were sitting at the terminals - and each team with access to an 8.2-m telescope! From now on, the powerful "Paranal Quartet" will be observing night after night, with a combined mirror surface of more than 210 m 2. And beginning next year, some of them will be linked to form part of the unique VLT Interferometer with unparalleled sensitivity and image sharpness. YEPUN "First Light" Early in the evening, the fourth 8.2-m Unit Telescope, YEPUN , was pointed to the sky for the first time and successfully achieved "First Light". Following a few technical exposures, a series of "first light" photos was made of several astronomical objects with the VLT Test Camera. This instrument was also used for the three previous "First Light" events for ANTU ( May 1998 ), KUEYEN ( March 1999 ) and MELIPAL ( January 2000 ). These images served to evaluate provisionally the performance of the new telescope, mainly in terms of mechanical and optical quality. The ESO staff were very pleased with the results and pronounced YEPUN fit for the subsequent commissioning phase. When the name YEPUN was first given to the fourth VLT Unit Telescope, it was supposed to mean "Sirius" in the Mapuche language. However, doubts have since arisen about this translation and a detailed investigation now indicates that the correct meaning is "Venus" (as the Evening Star). For a detailed explanation, please consult the essay On the Meaning of "YEPUN" , now available at the ESO website. The first images At 21:39 hrs local time (01:39 UT), YEPUN was turned to point in the direction of a dense Milky Way field, near the border between the constellations Sagitta (The Arrow) and Aquila (The Eagle). A guide star was acquired and the active optics system quickly optimized the

  11. External motion tracking for brain imaging: structured light tracking with invisible light

    DEFF Research Database (Denmark)

    Olesen, Oline Vinter; Paulsen, Rasmus Reinhold; Højgaard, Liselotte

    2010-01-01

    The importance of motion correction in 3D medical imaging increases with increasing scanner resolution. It is necessary for scanners with long image acquisition and low contrast images to correct for patient motion in order to optimize image quality. We present a near infrared structured light...... stereo depth map system for head motion estimation inside 3D medical scanners with limited space....

  12. Uppaal Stratego for Intelligent Traffic Lights

    DEFF Research Database (Denmark)

    Eriksen, Andreas Berre; Huang, Chao; Kildebogaard, Jan

    2017-01-01

    not profit from this additional information. Using this information could minimize waiting times and energy waste. Uppaal Stratego is a tool that combines machine learning and model checking techniques to synthesize near optimal control strategies. The tool has been applied successfully to several case......Modern traffic lights use information from induction loops and to some extend radar information. Recent developments in radar technology has made it possible to obtain more detailed information relevant to the control mechanism of the traffic light. Unfortunately much of the current controllers do...

  13. Optical bistability controlling light with light

    CERN Document Server

    Gibbs, Hyatt

    1985-01-01

    Optical Bistability: Controlling Light with Light focuses on optical bistability in nonlinear optical systems. Emphasis is on passive (non-laser) systems that exhibit reversible bistability with input intensity as the hysteresis variable, along with the physics and the potential applications of such systems for nonlinear optical signal processing. This book consists of seven chapters and begins with a historical overview of optical bistability in lasers and passive systems. The next chapter describes steady-state theories of optical bistability, including the Bonifacio-Lugiato model, as we

  14. Geolocation by light

    DEFF Research Database (Denmark)

    Lisovski, Simeon; Hewson, Chris M.; Klaassen, Raymond H. G.

    2012-01-01

    1. Geolocation by light allows for tracking animal movements, based on measurements of light intensity over time by a data-logging device (‘geolocator’). Recent developments of ultra-light devices (.... However, an inherent problem of geolocators is that any factor or process that changes the natural light intensity pattern also affects the positions calculated from these light patterns. Although the most important factors have been identified, estimation of their effect on the accuracy and precision...... of positions estimated has been lacking but is very important for the analyses and interpretation of geolocator data. 2. The ‘threshold method’ is mainly used to derive positions by defining sunrise and sunset times from the light intensity pattern for each recorded day. This method requires calibration...

  15. Framing Light Rail Projects

    DEFF Research Database (Denmark)

    Olesen, Mette

    2014-01-01

    In Europe, there has been a strong political will to implement light rail. This article contributes to the knowledge concerning policies around light rail by analysing how local actors frame light rail projects and which rationalities and arguments are present in this decision-making process....... The article draws on the socio-technical approach to mobilities studies in order to reassemble the decision-making process in three European cases: Bergen, Angers, and Bern. This article provides insights into the political, discursive and material production of light rail mobilities in a European context....... It identifies the planning rationales behind the systems and the policies that have been supportive of this light rail vision. Finally, the article identifies the practical challenges and potentials that have been connected to the different local frames of light rail mobility which can be used in future...

  16. Light metal production

    Science.gov (United States)

    Fan, Qinbai

    2016-04-19

    An electrochemical process for the production of light metals, particularly aluminum. Such a process involves contacting a light metal source material with an inorganic acid to form a solution containing the light metal ions in high concentration. The solution is fed to an electrochemical reactor assembly having an anode side containing an anode and a cathode side containing a cathode, with anode side and the cathode side separated by a bipolar membrane, with the solution being fed to the anode side. Light metal ions are electrochemically transferred through the bipolar membrane to the cathode side. The process further involves reducing the light metal ions to light metal powder. An associated processing system is also provided.

  17. Touched by Light

    Directory of Open Access Journals (Sweden)

    Siegrun Appelt

    2017-06-01

    Full Text Available With LED as illuminant a new era of dealing with lighting has dawned. Digitalisation, light guidance and light quality take on greater significance. Physical and emotional impacts of light on the human being have become common topics in the everyday life of a modern society. The amount of light which determines the character of spaces is steadily increasing. Our visual perception has adapted and assimilated to it over the years, decades, centuries. What was once perceived as bright today can’t either be used in a functional way or even less meet current standardization regulations. The project “Langsames Licht / Slow Light” searches for ways to practically implement theoretical insights and experience from the subjects of art, science and design, allowing a targeted use of light.

  18. Hydrogels for efficient light delivery in optogenetic applications

    Science.gov (United States)

    Johannsmeier, S.; Torres, M. L.; Ripken, T.; Heinemann, D.; Heisterkamp, A.

    2018-02-01

    Light-based therapies have been established for various indications, such as skin conditions, cancer or neonatal jaundice. Advances in the field of optogenetics open up new horizons for light-tissue interactions with an organism-wide impact. Excitable tissues, such as nerve and muscle tissues, can be controlled by light after the introduction of light-sensitive ion channels. Since these organs are generally not easily accessible to illumination in vivo, there is an increasing need for effective biocompatible waveguides for light delivery. These devices not only have to guide and distribute the light as desired with minimal losses, they should also mimic the mechanical properties of the surrounding tissue to ensure compatibility. In this project, we are tuning the properties of hydrogels from poly(ethylene glycol) derivatives to achieve compatibility with muscle tissue as well as optimal light guiding and distribution for optogenetic applications at the heart. The excitation light is coupled into the hydrogel with a biocompatible fiber. Properties of the hydrogel are mainly tuned by monomer length and concentration. Total reflection can be achieved by embedding a fiber-like hydrogel with a high refractive index into a second, low refractive index gel. Different geometries and scattering microparticles are used for light distribution in a flat gel patch. Targeted cell attachment can be achieved by introducing a protein layer to the otherwise bioinert gel. After optimization, the hydrogel may be used to deliver light for the excitation of genetically altered cardiomyocytes for controlled contraction.

  19. Strange Light Nuclei

    Directory of Open Access Journals (Sweden)

    Nakamura Satoshi N.

    2014-04-01

    Full Text Available “Strange” means 1 unusual or surprising, especially in a way that is difficult to explain or understand or 2 having strangeness degree of freedom. Light nuclear systems with strangeness, light hypernuclei, are perfect playground to study baryon force which would be a bridge between well established nuclear force in low energy region and QCD, the first principle of the strong interaction. Overview of study of light hypernuclei is given and recent experimental findings are reviewed.

  20. Berkeley Lighting Cone

    Energy Technology Data Exchange (ETDEWEB)

    Lask, Kathleen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gadgil, Ashok [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-10-24

    A lighting cone is a simple metal cone placed on the fuel bed of a stove during ignition to act as a chimney, increasing the draft through the fuel bed. Many stoves tend to be difficult to light due to poor draft through the fuel bed, so lighting cones are used in various parts of the world as an inexpensive accessory to help with ignition.

  1. 3D light robotics

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Palima, Darwin; Villangca, Mark Jayson

    2016-01-01

    As celebrated by the Nobel Prize 2014 in Chemistry light-based technologies can now overcome the diffraction barrier for imaging with nanoscopic resolution by so-called super-resolution microscopy1. However, interactive investigations coupled with advanced imaging modalities at these small scale ...... research discipline that could potentially be able to offer the full packet needed for true "active nanoscopy" by use of so-called light-driven micro-robotics or Light Robotics in short....

  2. Quantum states of light

    CERN Document Server

    Furusawa, Akira

    2015-01-01

    This book explains what quantum states of light look like. Of special interest, a single photon state is explained by using a wave picture, showing that it corresponds to the complementarity of a quantum. Also explained is how light waves are created by photons, again corresponding to the complementarity of a quantum. The author shows how an optical wave is created by superposition of a "vacuum" and a single photon as a typical example. Moreover, squeezed states of light are explained as "longitudinal" waves of light and Schrödinger's cat states as macroscopic superposition states.

  3. Light, Matter, and Geometry

    DEFF Research Database (Denmark)

    Frisvad, Jeppe Revall

    Interaction of light and matter produces the appearance of materials. To deal with the immense complexity of nature, light and matter is modelled at a macroscopic level in computer graphics. This work is the first to provide the link between the microscopic physical theories of light and matter...... of a material and determine the contents of the material. The book is in four parts. Part I provides the link between microscopic and macroscopic theories of light. Part II describes how to use the properties of microscopic particles to compute the macroscopic properties of materials. Part III illustrates...

  4. Light and Sound

    CERN Document Server

    Karam, P Andrew

    2010-01-01

    Our world is largely defined by what we see and hear-but our uses for light and sound go far beyond simply seeing a photo or hearing a song. A concentrated beam of light, lasers are powerful tools used in industry, research, and medicine, as well as in everyday electronics like DVD and CD players. Ultrasound, sound emitted at a high frequency, helps create images of a developing baby, cleans teeth, and much more. Light and Sound teaches how light and sound work, how they are used in our day-to-day lives, and how they can be used to learn about the universe at large.

  5. Dissecting a Light Echo

    Science.gov (United States)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for audio animation This animation illustrates how a light echo works, and how an optical illusion of material moving outward is created. A light echo occurs when a star explodes, acting like a cosmic flashbulb. The light from this explosion zips through nearby dust clumps, illuminating and heating them up slightly. This brief period of warming causes them to glow in infrared, like a chain of Christmas bulbs lighting up one by one. The animation starts by showing the explosion of a star, which results in a flash of light that moves outward in all directions. The direction of our line of sight from Earth is indicated by the blue arrow. When the light flash reaches surrounding dust, shown here as three dark clouds, the dust is heated up, creating infrared light that begins to travel toward Earth (indicated by the red arrows). Dust closest to the explosion lights up first, while the explosion's shock wave takes longer to reach more distant material. This results in light from different parts of the cloud reaching Earth at different times, creating the illusion of motion over time. As the animation shows, the inclination of the cloud toward our line of sight can result in the material seeming to move both away from and toward the central star.

  6. Light-driven nano-robotics for sub-diffraction probing and sensing

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Bañas, Andrew Rafael; Palima, Darwin

    On the macro-scale robotics typically uses light for carrying information for machine vision for and feedback in artificially intelligent guidance systems and monitoring. Using the miniscule momentum of light shrinking robots down to the micro- and even nano-scale regime creates opportunities......]. Therefore, a generic approach for optimizing lightmatter interaction involves the combination of optimal light-shaping techniques with the use of optimized nano-featured shapes in light-driven micro-robotics structures. In this work, we designed different three-dimensional micro-structures and fabricated...

  7. Optimal back-to-front airplane boarding

    Science.gov (United States)

    Bachmat, Eitan; Khachaturov, Vassilii; Kuperman, Ran

    2013-06-01

    The problem of finding an optimal back-to-front airplane boarding policy is explored, using a mathematical model that is related to the 1+1 polynuclear growth model with concave boundary conditions and to causal sets in gravity. We study all airplane configurations and boarding group sizes. Optimal boarding policies for various airplane configurations are presented. Detailed calculations are provided along with simulations that support the main conclusions of the theory. We show that the effectiveness of back-to-front policies undergoes a phase transition when passing from lightly congested airplanes to heavily congested airplanes. The phase transition also affects the nature of the optimal or near-optimal policies. Under what we consider to be realistic conditions, optimal back-to-front policies lead to a modest 8-12% improvement in boarding time over random (no policy) boarding, using two boarding groups. Having more than two groups is not effective.

  8. Optimal back-to-front airplane boarding.

    Science.gov (United States)

    Bachmat, Eitan; Khachaturov, Vassilii; Kuperman, Ran

    2013-06-01

    The problem of finding an optimal back-to-front airplane boarding policy is explored, using a mathematical model that is related to the 1+1 polynuclear growth model with concave boundary conditions and to causal sets in gravity. We study all airplane configurations and boarding group sizes. Optimal boarding policies for various airplane configurations are presented. Detailed calculations are provided along with simulations that support the main conclusions of the theory. We show that the effectiveness of back-to-front policies undergoes a phase transition when passing from lightly congested airplanes to heavily congested airplanes. The phase transition also affects the nature of the optimal or near-optimal policies. Under what we consider to be realistic conditions, optimal back-to-front policies lead to a modest 8-12% improvement in boarding time over random (no policy) boarding, using two boarding groups. Having more than two groups is not effective.

  9. Geometric properties of optimal photonic crystals

    DEFF Research Database (Denmark)

    Sigmund, Ole; Hougaard, Kristian G.

    2008-01-01

    Photonic crystals can be designed to control and confine light. Since the introduction of the concept by Yablonovitch and John two decades ago, there has been a quest for the optimal structure, i.e., the periodic arrangement of dielectric and air that maximizes the photonic band gap. Based...

  10. Light + Light = Darkness : searching for exoplanets

    NARCIS (Netherlands)

    Mieremet, A.; Braat, J.; Hartmann, L.

    2002-01-01

    Arjan Mieremet, a doctorate student in the Optics section at Applied Physics, wants to extinguish stellar light in order to see the planets around it. The idea originated over twenty years ago, but so far nobody has managed to construct the necessary optical equipment. Mieremet tried, and soon ran

  11. Severe asthma with markedly increased asbestos of 2 types & TXB2, and markedly reduced acetylcholine, DHEA & drug uptake in parts of upper lungs, & similar abnormalities at respiratory & cardiac center of medulla oblongata: complete elimination of this asthma within 15 days using one optimal dose of astragalus & application of strong red light & EMF neutralizer on respiratory centers of abnormal medulla oblongata.

    Science.gov (United States)

    Omura, Yoshiaki; Henoch, Avraham; Shimotsuura, Yasuhira; Duvvi, Harsha; Kawashima, Hiroshi; Ohki, Motomu

    2009-01-01

    When the window of an Asbestos-contaminated room from a broken ceiling was opened wide, A 73 year-old male physician of Oriental origin, who was sitting in the next room, suddenly developed a severe asthma attack, which did not stop by the use of a hand-held Albuterol inhaler. Temporary relief was obtained only by using a Compressor-Nebulizer (Inspiration 626 with Albuterol Sulfate Inhalation Solution 0.083%). During the attack, abnormal areas were discovered at the upper lobes of both lungs, where Thromboxane B2 (TXB2) was markedly increased to 500 ng (BDORT units) (the rest of the lung had about 2.5 ng), 2 types of Asbestos (Chrysotile and Crocidolite) were abnormally increased to 0.120-0.135 mg, (BDORT units) Acetylcholine was markedly reduced to 0.5 ng (the rest of the lung was low, about 100 ng), DHEA was extremely reduced to 1 ng (the rest of the lung had about 52 ng), and telomere was less than 1 yg (= 10(-24) g). Bacterial & viral infections were also present in these abnormal areas, but no antibiotics entered the abnormal parts of the lungs. Therefore, one optimal dose of Astragalus was given once, which resulted in a rapid continuous excretion of large amounts of the above 2 types of Asbestos & TXB2 in urine & sputum, and Asthma symptoms reduced slightly in severity. Additional acupuncture & shiatsu given on all the known acupuncture points for lung disease only created slight, temporary improvement. Then, the respiratory & cardiac center of the Medulla Oblongata was found to have similar abnormalities as the lungs. Therefore, 100 mW output of Light Emitting Diode of red spectra (650 nm center spectrum) was projected on the abnormal area of the medulla oblongata on the back of the head. This resulted drug uptake of on and off and significantly reduced difficulty of breathing. Additional application of the EMF Neutralizer on the abnormal area of the Medulla Oblongata for 3 hours resulted in continuous drug uptake and complete disappearance of asthma. As a

  12. Optimization modeling with spreadsheets

    CERN Document Server

    Baker, Kenneth R

    2015-01-01

    An accessible introduction to optimization analysis using spreadsheets Updated and revised, Optimization Modeling with Spreadsheets, Third Edition emphasizes model building skills in optimization analysis. By emphasizing both spreadsheet modeling and optimization tools in the freely available Microsoft® Office Excel® Solver, the book illustrates how to find solutions to real-world optimization problems without needing additional specialized software. The Third Edition includes many practical applications of optimization models as well as a systematic framework that il

  13. Discrete Line Congruences for Shading and Lighting

    KAUST Repository

    Wang, Jun

    2013-07-01

    Two-parameter families of straight lines (line congruences) are implicitly present in graphics and geometry processing in several important ways including lighting and shape analysis. In this paper we make them accessible to optimization and geometric computing, by introducing a general discrete version of congruences based on piecewise-linear correspondences between triangle meshes. Our applications of congruences are based on the extraction of a so-called torsion-free support structure, which is a procedure analogous to remeshing a surface along its principal curvature lines. A particular application of such structures are freeform shading and lighting systems for architecture. We combine interactive design of such systems with global optimization in order to satisfy geometric constraints. In this way we explore a new area where architecture can greatly benefit from graphics.

  14. The synchrotron light source ROSY

    International Nuclear Information System (INIS)

    Einfeld, D.; Buettig, H.; Dienel, S.; Glaeser, W.; Goetz, T.; Guratzsch, H.; Hartmann, B.; Janssen, D.; Krug, H.; Linnemann, J.; Matz, W.; Murphy, J.B.; Neumann, W.; Oehme, W.; Picard, M.; Plesko, M.; Proehl, D.; Schlenk, R.; Tomassini, D.; Tyrroff, H.

    1994-01-01

    ROSY, a 3rd generation synchrotron light source, has been proposed to be built at the Research Center Rossendorf/Dresden in Germany. With its low emittance and optimized space for installing insertion devices ROSY will be the first synchrotron radiation source in the 3 GeV range in Europe, dedicated to materials research and industrial application. The critical wavelength of the synchrotron radiation spectra was designed to be 0.15 nm corresponding to a critical photon energy of 8.4 keV. It is proposed to use a ''modified multiple bend achromat'' (MBA) lattice in order to get a compact machine as well as a low emittance. For 3 GeV an emittance smaller than 30π nm rad can be obtained. With a fourfold symmetry and two larger straight sections within the achromatic arcs the circumference is 148 m. 23% of the circumference can be used for installing insertion devices. (orig.)

  15. Combinatorial optimization theory and algorithms

    CERN Document Server

    Korte, Bernhard

    2018-01-01

    This comprehensive textbook on combinatorial optimization places special emphasis on theoretical results and algorithms with provably good performance, in contrast to heuristics. It is based on numerous courses on combinatorial optimization and specialized topics, mostly at graduate level. This book reviews the fundamentals, covers the classical topics (paths, flows, matching, matroids, NP-completeness, approximation algorithms) in detail, and proceeds to advanced and recent topics, some of which have not appeared in a textbook before. Throughout, it contains complete but concise proofs, and also provides numerous exercises and references. This sixth edition has again been updated, revised, and significantly extended. Among other additions, there are new sections on shallow-light trees, submodular function maximization, smoothed analysis of the knapsack problem, the (ln 4+ɛ)-approximation for Steiner trees, and the VPN theorem. Thus, this book continues to represent the state of the art of combinatorial opti...

  16. Experiments Planning, Analysis, and Optimization

    CERN Document Server

    Wu, C F Jeff

    2011-01-01

    Praise for the First Edition: "If you . . . want an up-to-date, definitive reference written by authors who have contributed much to this field, then this book is an essential addition to your library."-Journal of the American Statistical Association Fully updated to reflect the major progress in the use of statistically designed experiments for product and process improvement, Experiments, Second Edition introduces some of the newest discoveries-and sheds further light on existing ones-on the design and analysis of experiments and their applications in system optimization, robustness, and tre

  17. Lighting for Education.

    Science.gov (United States)

    Ontario Ministry of Colleges and Universities, Toronto.

    Some of the qualities and quantities that must be juggled to produce good lighting for educational facilities are analyzed with photographs, tables, and drawings. The three categories of lamps used for school lighting (incandescent, fluorescent, and high intensity discharge) are described; a lamp selection guide gives the design characteristics of…

  18. Autonomous photovoltaic lighting system

    OpenAIRE

    Hafez, Ahmed A. A.; Montesinos Miracle, Daniel; Sudrià Andreu, Antoni

    2012-01-01

    This paper introduces a comparison between the conventional and Photovoltaic (PV) lighting systems. A simple sizing procedure for a PV stand-alone system was advised. The paper also proposes a novel PV lighting system. The proposed system is simple, compact and reliable. The system operation was investigated by thoroughly mathematical and simulation work.

  19. Occupant Controlled Lighting

    DEFF Research Database (Denmark)

    Logadóttir, Ásta

    2011-01-01

    preferences for correlated colour temperature (CCT). The results suggest that the method of adjustment, previously used in the lighting literature, is not adequate to generalize about occupant preferences for illuminance or CCT. Factors that influence occupants’ lighting preference when applying the method...

  20. Road lighting for safety.

    NARCIS (Netherlands)

    Schreuder, D.A.

    2000-01-01

    This book is aimed at broad readership, not especially at lighting experts. Lighting is presented as a system, as part of the public highway. Much attention is paid to subjects not greatly covered in the specialist literature, such as environmental aspects, traffic safety, crime prevention, and the