Sample records for absolute light intensity

  1. Variation in light intensity with height and time from subsequent lightning return strokes

    NASA Technical Reports Server (NTRS)

    Jordan, D. M.; Uman, M. A.

    1983-01-01

    Photographic measurements of relative light intensity as a function of height and time have been conducted for seven return strokes in two lightning flashes at 7.8 and 8.7 km ranges, using film which possesses an approximately constant spectral response in the 300-670 nm range. The amplitude of the initial light peak is noted to decrease exponentially with height, with a decay constant of 0.6-0.8 km. The logarithm of the peak light intensity near the ground is found to be approximately proportional to the initial peak electric field intensity, implying that the current decrease with height may be much slower than the light decrease. Absolute light intensity is presently estimated through the integration of the photographic signals from individual channel segments, in order to simulate the calibrated, all-sky photoelectric data of Guo and Krider (1982).

  2. Light intensity compressor

    DOEpatents

    Rushford, Michael C.

    1990-02-06

    In a system for recording images having vastly differing light intensities over the face of the image, a light intensity compressor is provided that utilizes the properties of twisted nematic liquid crystals to compress the image intensity. A photoconductor or photodiode material that is responsive to the wavelength of radiation being recorded is placed adjacent a layer of twisted nematic liquid crystal material. An electric potential applied to a pair of electrodes that are disposed outside of the liquid crystal/photoconductor arrangement to provide an electric field in the vicinity of the liquid crystal material. The electrodes are substantially transparent to the form of radiation being recorded. A pair of crossed polarizers are provided on opposite sides of the liquid crystal. The front polarizer linearly polarizes the light, while the back polarizer cooperates with the front polarizer and the liquid crystal material to compress the intensity of a viewed scene. Light incident upon the intensity compressor activates the photoconductor in proportion to the intensity of the light, thereby varying the field applied to the liquid crystal. The increased field causes the liquid crystal to have less of a twisting effect on the incident linearly polarized light, which will cause an increased percentage of the light to be absorbed by the back polarizer. The intensity of an image may be compressed by forming an image on the light intensity compressor.

  3. Light intensity compressor

    DOEpatents

    Rushford, Michael C.

    1990-01-01

    In a system for recording images having vastly differing light intensities over the face of the image, a light intensity compressor is provided that utilizes the properties of twisted nematic liquid crystals to compress the image intensity. A photoconductor or photodiode material that is responsive to the wavelength of radiation being recorded is placed adjacent a layer of twisted nematic liquid crystal material. An electric potential applied to a pair of electrodes that are disposed outside of the liquid crystal/photoconductor arrangement to provide an electric field in the vicinity of the liquid crystal material. The electrodes are substantially transparent to the form of radiation being recorded. A pair of crossed polarizers are provided on opposite sides of the liquid crystal. The front polarizer linearly polarizes the light, while the back polarizer cooperates with the front polarizer and the liquid crystal material to compress the intensity of a viewed scene. Light incident upon the intensity compressor activates the photoconductor in proportion to the intensity of the light, thereby varying the field applied to the liquid crystal. The increased field causes the liquid crystal to have less of a twisting effect on the incident linearly polarized light, which will cause an increased percentage of the light to be absorbed by the back polarizer. The intensity of an image may be compressed by forming an image on the light intensity compressor.

  4. Absolute versus relative intensity of physical activity in a dose-response context.

    PubMed

    Shephard, R J

    2001-06-01

    To examine the importance of relative versus absolute intensities of physical activity in the context of population health. A standard computer-search of the literature was supplemented by review of extensive personal files. Consensus reports (Category D Evidence) have commonly recommended moderate rather than hard physical activity in the context of population health. Much of the available literature provides Category C Evidence. It has often confounded issues of relative intensity with absolute intensity or total weekly dose of exercise. In terms of cardiovascular health, there is some evidence for a threshold intensity of effort, perhaps as high as 6 METs, in addition to a minimum volume of physical activity. Decreases in blood pressure and prevention of stroke seem best achieved by moderate rather than high relative intensities of physical activity. Many aspects of metabolic health depend on the total volume of activity; moderate relative intensities of effort are more effective in mobilizing body fat, but harder relative intensities may help to increase energy expenditures postexercise. Hard relative intensities seem needed to augment bone density, but this may reflect an associated increase in volume of activity. Hard relative intensities of exercise induce a transient immunosuppression. The optimal intensity of effort, relative or absolute, for protection against various types of cancer remains unresolved. Acute effects of exercise on mood state also require further study; long-term benefits seem associated with a moderate rather than a hard relative intensity of effort. The importance of relative versus absolute intensity of effort depends on the desired health outcome, and many issues remain to be resolved. Progress will depend on more precise epidemiological methods of assessing energy expenditures and studies that equate total energy expenditures between differing relative intensities. There is a need to focus on gains in quality-adjusted life expectancy.

  5. Prediction of absolute infrared intensities for the fundamental vibrations of H2O2

    NASA Technical Reports Server (NTRS)

    Rogers, J. D.; Hillman, J. J.

    1981-01-01

    Absolute infrared intensities are predicted for the vibrational bands of gas-phase H2O2 by the use of a hydrogen atomic polar tensor transferred from the hydroxyl hydrogen atom of CH3OH. These predicted intensities are compared with intensities predicted by the use of a hydrogen atomic polar tensor transferred from H2O. The predicted relative intensities agree well with published spectra of gas-phase H2O2, and the predicted absolute intensities are expected to be accurate to within at least a factor of two. Among the vibrational degrees of freedom, the antisymmetric O-H bending mode nu(6) is found to be the strongest with a calculated intensity of 60.5 km/mole. The torsional band, a consequence of hindered rotation, is found to be the most intense fundamental with a predicted intensity of 120 km/mole. These results are compared with the recent absolute intensity determinations for the nu(6) band.

  6. Absolute intensity of radiation emitted by uranium plasmas

    NASA Technical Reports Server (NTRS)

    Jalufka, N. W.; Lee, J. H.; Mcfarland, D. R.

    1975-01-01

    The absolute intensity of radiation emitted by fissioning and nonfissioning uranium plasmas in the spectral range from 350 nm to 1000 nm was measured. The plasma was produced in a plasma-focus apparatus and the plasma properties are simular to those anticipated for plasma-core nuclear reactors. The results are expected to contribute to the establishment of design criteria for the development of plasma-core reactors.

  7. Estimation of effective day length at any light intensity using solar radiation data.

    PubMed

    Yokoya, Masana; Shimizu, Hideyasu

    2011-11-01

    The influence of day length on living creatures differs with the photosensitivity of the creature; however, the possible sunshine duration (N(0)) might be an inadequate index of the photoperiod for creatures with low light sensitivity. To address this issue, the authors tried to estimate the effective day length, i.e., the duration of the photoperiod that exceeds a certain threshold of light intensity. Continual global solar radiation observation data were gathered from the baseline surface radiation network (BSRN) of 18 sites from 2004 to 2007 and were converted to illuminance data using a luminous efficiency model. The monthly average of daily photoperiods exceeding each defined intensity (1 lx, 300 lx, … 20,000 lx) were calculated [defined as Ne(() (lux) ())]. The relationships between the monthly average of global solar radiation (Rs), N(0), and Ne(() (lux) ()) were investigated. At low light intensity (<500 lx), Ne(() (lux) ()) were almost the same as N(0). At high light intensity (>10,000 lx), Ne(() (lux) ()) and Rs showed a logarithmic relationship. Using these relationships, empirical models were derived to estimate the effective day length at different light intensities. According to the validation of the model, the effective day length for any light intensity could be estimated with an accuracy of less than 11% of the mean absolute percentage error (MAPE) in the estimation of the monthly base photoperiod. Recently, a number of studies have provided support for a link between day length and some diseases. Our results will be useful in further assessing the relationships between day length and these diseases.

  8. Absolute Configuration from Different Multifragmentation Pathways in Light-Induced Coulomb Explosion Imaging.

    PubMed

    Pitzer, Martin; Kastirke, Gregor; Kunitski, Maksim; Jahnke, Till; Bauer, Tobias; Goihl, Christoph; Trinter, Florian; Schober, Carl; Henrichs, Kevin; Becht, Jasper; Zeller, Stefan; Gassert, Helena; Waitz, Markus; Kuhlins, Andreas; Sann, Hendrik; Sturm, Felix; Wiegandt, Florian; Wallauer, Robert; Schmidt, Lothar Ph H; Johnson, Allan S; Mazenauer, Manuel; Spenger, Benjamin; Marquardt, Sabrina; Marquardt, Sebastian; Schmidt-Böcking, Horst; Stohner, Jürgen; Dörner, Reinhard; Schöffler, Markus; Berger, Robert

    2016-08-18

    The absolute configuration of individual small molecules in the gas phase can be determined directly by light-induced Coulomb explosion imaging (CEI). Herein, this approach is demonstrated for ionization with a single X-ray photon from a synchrotron light source, leading to enhanced efficiency and faster fragmentation as compared to previous experiments with a femtosecond laser. In addition, it is shown that even incomplete fragmentation pathways of individual molecules from a racemic CHBrClF sample can give access to the absolute configuration in CEI. This leads to a significant increase of the applicability of the method as compared to the previously reported complete break-up into atomic ions and can pave the way for routine stereochemical analysis of larger chiral molecules by light-induced CEI. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Intense X-ray and EUV light source

    DOEpatents

    Coleman, Joshua; Ekdahl, Carl; Oertel, John

    2017-06-20

    An intense X-ray or EUV light source may be driven by the Smith-Purcell effect. The intense light source may utilize intense electron beams and Bragg crystals. This may allow the intense light source to range from the extreme UV range up to the hard X-ray range.

  10. Dependency between light intensity and refractive development under light-dark cycles.

    PubMed

    Cohen, Yuval; Belkin, Michael; Yehezkel, Oren; Solomon, Arieh S; Polat, Uri

    2011-01-01

    The emmetropization process involves fine-tuning the refractive state by altering the refractive components toward zero refraction. In this study, we provided light-dark cycle conditions at several intensities and examined the effect of light intensity on the progression of chicks' emmetropization. Chicks under high-, medium-, and low-light intensities (10,000, 500, and 50 lux, respectively) were followed for 90 days by retinoscopy, keratometry, as well as ultrasound measurements. Emmetropization was reached from days 30-50 and from days 50-60 for the low- and medium-intensity groups, respectively. On day 90, most chicks in the low-intensity group were myopic, with a mean refraction of -2.41D (95% confidence interval (CI) -2.9 to -1.8D), whereas no chicks in the high-intensity group developed myopia, but they exhibited a stable mean hyperopia of +1.1D. The medium-intensity group had a mean refraction of +0.03D. The low-intensity group had a deeper vitreous chamber depth and a longer axial length compared with the high-intensity group, and shifted refraction to the myopic side. The low-intensity group had a flatter corneal curvature, a deeper anterior chamber, and a thinner lens compared with the high-intensity group, and shifted refraction to the hyperopic side. In all groups the corneal power was correlated with the three examined levels of log light intensity for all examined times (e.g., day 20 r = 0.6 P < 0.0001, day 90 r = 0.56 P < 0.0001). Thus, under light-dark cycles, light intensity is an environmental factor that modulates the process of emmetropization, and the low intensity of ambient light is a risk factor for developing myopia. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. 33 CFR 84.15 - Intensity of lights.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Intensity of lights. 84.15... NAVIGATION RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.15 Intensity of lights. (a) The minimum luminous intensity of lights will be calculated by using the formula: I = 3.43 × 106...

  12. Variation in light intensity with height and time from subsequent lightning return strokes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jordan, D.M.; Uman, M.A.

    1983-08-20

    Relative light intensity has been measured photographically as a function of height and time for seven subsequent return strokes in two lightning flashes at ranges of 7.8 and 8.7 km. The film used was Kodak 5474 Shellburst, which has a roughly constant spectral response between 300 and 670 nm. The time resolution was about 1.0 ..mu..s, and the spatial resolution was about 4 m. The observed light signals consisted of a fast rise to peak, followed by a slower decrease to a relatively constant value. The amplitude of the initial light peak decreases exponentially with height with a decay constantmore » of about 0.6 to 0.8 km. The 20% to 80% rise time of the initial light signal is between 1 and 4 ..mu..s near ground and increases by an additional 1 to 2 ..mu..s by the time the return stroke reaches the cloud base, a height between 1 and 2 km. The light intensity 30 ..mu..s after the initial peak is relatively constant with height and has an amplitude that is 15% to 30% of the initial peak near the ground and 50% to 100% of the initial peak at cloud base. The logarithm of the peak light intensity near the ground is roughly proportional to the initial peak electric field intensity, and this in turn implies that the current decrease with height may be much slower than the light decrease. The absolute light intensity has been estimated by integrating the photographic signals from individual channel segments to simulate the calibrated all-sky photoelectric data of Guo and Krider (1982). Using this method, the authors find that the mean peak radiance near the ground is 8.3 x 10/sup 5/ W/m, with a total range from 1.4 x 10/sup 5/ to 3.8 x 10/sup 6/ W/m. 16 references, 11 figures.« less

  13. 33 CFR 84.15 - Intensity of lights.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Intensity of lights. 84.15... NAVIGATION RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.15 Intensity of lights. (a) The minimum luminous intensity of lights shall be calculated by using the formula: I=3.43×106×T...

  14. 33 CFR 84.15 - Intensity of lights.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Intensity of lights. 84.15... NAVIGATION RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.15 Intensity of lights. (a) The minimum luminous intensity of lights will be calculated by using the formula: I=3.43×106 ×T...

  15. 33 CFR 84.15 - Intensity of lights.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Intensity of lights. 84.15... NAVIGATION RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.15 Intensity of lights. (a) The minimum luminous intensity of lights will be calculated by using the formula: I=3.43×106 ×T...

  16. 33 CFR 84.15 - Intensity of lights.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Intensity of lights. 84.15... NAVIGATION RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.15 Intensity of lights. (a) The minimum luminous intensity of lights shall be calculated by using the formula: I=3.43×106×T...

  17. Battery Charge Affects the Stability of Light Intensity from Light-emitting Diode Light-curing Units.

    PubMed

    Tongtaksin, A; Leevailoj, C

    This study investigated the influence of battery charge levels on the stability of light-emitting diode (LED) curing-light intensity by measuring the intensity from fully charged through fully discharged batteries. The microhardness of resin composites polymerized by the light-curing units at various battery charge levels was measured. The light intensities of seven fully charged battery LED light-curing units-1) LY-A180, 2) Bluephase, 3) Woodpecker, 4) Demi Plus, 5) Saab II, 6) Elipar S10, and 7) MiniLED-were measured with a radiometer (Kerr) after every 10 uses (20 seconds per use) until the battery was discharged. Ten 2-mm-thick cylindrical specimens of A3 shade nanofilled resin composite (PREMISE, Kerr) were prepared per LED light-curing unit group. Each specimen was irradiated by the fully charged light-curing unit for 20 seconds. The LED light-curing units were then used until the battery charge fell to 50%. Specimens were prepared again as described above. This was repeated again when the light-curing units' battery charge fell to 25% and when the light intensity had decreased to 400 mW/cm 2 . The top/bottom surface Knoop hardness ratios of the specimens were determined. The microhardness data were analyzed by one-way analysis of variance with Tukey test at a significance level of 0.05. The Pearson correlation coefficient was used to determine significant correlations between surface hardness and light intensity. We found that the light intensities of the Bluephase, Demi Plus, and Elipar S10 units were stable. The intensity of the MiniLED unit decreased slightly; however, it remained above 400 mW/cm 2 . In contrast, the intensities of the LY-A180, Woodpecker, and Saab II units decreased below 400 mW/cm 2 . There was also a significant decrease in the surface microhardnesses of the resin composite specimens treated with MiniLED, LY-A180, Woodpecker, and Saab II. In conclusion, the light intensity of several LED light-curing units decreased as the battery was

  18. The effects of season, aeration and light intensity on the performance of pacific whiteleg shrimp (Litopenaeus vannamei) polycultured with seaweed (Gracilaria verrucosa)

    NASA Astrophysics Data System (ADS)

    Susilowati, T.; Desrina; Hutabarat, J.; Anggoro, S.; Zainuri, M.; Sarjito; Basuki, F.; Yuniarti, T.

    2018-04-01

    This study was aimed to determine impact of stocking season, additional oxygen supply and light intensity on performance of pacific white leg shrimp (Litopenaeus vannamei) polycultured with seaweed Gracilaria verrucosa. Three sets of experiments were used and each experiment was conducted separately in 3 different season (factor W). Three factors and the interaction, that is, stocking seasons (W1: March-June;. W2 : July-October and W3 : November-February), Oxygen supply (O, with or without supply aeration of 6.5 ppm) and light intensity (with or without addition of light 640 lux) was observed. The experiment was conducted in 16 polyethilen net place in concrete tanks (1.2 m3). Shrimp (average weight 0.1 g and lenght 1.2 cm) with density 94 shrimp/m3 and seaweed 2.188 g/m3, cultured for 94 days. Data collected included absolute growth, specific growth rate (SGR), survival rate (SR) and biomass production of shrimp and seaweed. The result showed that culture period March to June, additonal light and suply DO gave the best result with shrimp absolute growth 13.23 g, SGR 5.09 %/day, SR 99.64 % and biomass production 1.256.36 g/m3. Absolute growth of G. verrucosa was 5.223.75g, SGR 268 %/day and biomass production 12.608.55 g/m3.

  19. Absolute Distances to Nearby Type Ia Supernovae via Light Curve Fitting Methods

    NASA Astrophysics Data System (ADS)

    Vinkó, J.; Ordasi, A.; Szalai, T.; Sárneczky, K.; Bányai, E.; Bíró, I. B.; Borkovits, T.; Hegedüs, T.; Hodosán, G.; Kelemen, J.; Klagyivik, P.; Kriskovics, L.; Kun, E.; Marion, G. H.; Marschalkó, G.; Molnár, L.; Nagy, A. P.; Pál, A.; Silverman, J. M.; Szakáts, R.; Szegedi-Elek, E.; Székely, P.; Szing, A.; Vida, K.; Wheeler, J. C.

    2018-06-01

    We present a comparative study of absolute distances to a sample of very nearby, bright Type Ia supernovae (SNe) derived from high cadence, high signal-to-noise, multi-band photometric data. Our sample consists of four SNe: 2012cg, 2012ht, 2013dy and 2014J. We present new homogeneous, high-cadence photometric data in Johnson–Cousins BVRI and Sloan g‧r‧i‧z‧ bands taken from two sites (Piszkesteto and Baja, Hungary), and the light curves are analyzed with publicly available light curve fitters (MLCS2k2, SNooPy2 and SALT2.4). When comparing the best-fit parameters provided by the different codes, it is found that the distance moduli of moderately reddened SNe Ia agree within ≲0.2 mag, and the agreement is even better (≲0.1 mag) for the highest signal-to-noise BVRI data. For the highly reddened SN 2014J the dispersion of the inferred distance moduli is slightly higher. These SN-based distances are in good agreement with the Cepheid distances to their host galaxies. We conclude that the current state-of-the-art light curve fitters for Type Ia SNe can provide consistent absolute distance moduli having less than ∼0.1–0.2 mag uncertainty for nearby SNe. Still, there is room for future improvements to reach the desired ∼0.05 mag accuracy in the absolute distance modulus.

  20. OCT angiography by absolute intensity difference applied to normal and diseased human retinas

    PubMed Central

    Ruminski, Daniel; Sikorski, Bartosz L.; Bukowska, Danuta; Szkulmowski, Maciej; Krawiec, Krzysztof; Malukiewicz, Grazyna; Bieganowski, Lech; Wojtkowski, Maciej

    2015-01-01

    We compare four optical coherence tomography techniques for noninvasive visualization of microcapillary network in the human retina and murine cortex. We perform phantom studies to investigate contrast-to-noise ratio for angiographic images obtained with each of the algorithm. We show that the computationally simplest absolute intensity difference angiographic OCT algorithm that bases only on two cross-sectional intensity images may be successfully used in clinical study of healthy eyes and eyes with diabetic maculopathy and branch retinal vein occlusion. PMID:26309740

  1. 14 CFR 23.1389 - Position light distribution and intensities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Equipment Lights § 23.1389 Position light distribution and intensities. (a) General. The intensities prescribed in this section must be provided by new equipment with each light cover and color filter in place... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Position light distribution and intensities...

  2. 14 CFR 23.1389 - Position light distribution and intensities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Equipment Lights § 23.1389 Position light distribution and intensities. (a) General. The intensities prescribed in this section must be provided by new equipment with each light cover and color filter in place... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Position light distribution and intensities...

  3. 14 CFR 23.1389 - Position light distribution and intensities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Equipment Lights § 23.1389 Position light distribution and intensities. (a) General. The intensities prescribed in this section must be provided by new equipment with each light cover and color filter in place... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Position light distribution and intensities...

  4. Dissimilarity of yellow-blue surfaces under neutral light sources differing in intensity: separate contributions of light intensity and chroma.

    PubMed

    Tokunaga, Rumi; Logvinenko, Alexander D; Maloney, Laurence T

    2008-01-01

    Observers viewed two side-by-side arrays each of which contained three yellow Munsell papers, three blue, and one neutral Munsell. Each array was illuminated uniformly and independently of the other. The neutral light source intensities were 1380, 125, or 20 lux. All six possible combinations of light intensities were set as illumination conditions. On each trial, observers were asked to rate the dissimilarity between each chip in one array and each chip in the other by using a 30-point scale. Each pair of surfaces in each illumination condition was judged five times. We analyzed this data using non-metric multi-dimensional scaling to determine how light intensity and surface chroma contributed to dissimilarity and how they interacted. Dissimilarities were captured by a three-dimensional configuration in which one dimension corresponded to differences in light intensity.

  5. A method for improving the light intensity distribution in dental light-curing units.

    PubMed

    Arikawa, Hiroyuki; Takahashi, Hideo; Minesaki, Yoshito; Muraguchi, Kouichi; Matsuyama, Takashi; Kanie, Takahito; Ban, Seiji

    2011-01-01

    A method for improving the uniformity of the radiation light from dental light-curing units (LCUs), and the effect on the polymerization of light-activated composite resin are investigated. Quartz-tungsten halogen, plasma-arc, and light-emitting diode LCUs were used, and additional optical elements such as a mixing tube and diffusing screen were employed to reduce the inhomogeneity of the radiation light. The distribution of the light intensity from the light guide tip was measured across the guide tip, as well as the distribution of the surface hardness of the light-activated resin emitted with the LCUs. Although the additional optical elements caused 13.2-25.9% attenuation of the light intensity, the uniformity of the light intensity of the LCUs was significantly improved in the modified LCUs, and the uniformity of the surface hardness of the resin was also improved. Our results indicate that the addition of optical elements to the LCU may be a simple and effective method for reducing inhomogeneity in radiation light from the LCUs.

  6. Absolute calibration of a hydrogen discharge lamp in the vacuum ultraviolet

    NASA Technical Reports Server (NTRS)

    Nealy, J. E.

    1975-01-01

    A low-pressure hydrogen discharge lamp was calibrated for radiant intensity in the vacuum ultraviolet spectral region on an absolute basis and was employed as a laboratory standard source in spectrograph calibrations. This calibration was accomplished through the use of a standard photodiode detector obtained from the National Bureau of Standards together with onsite measurements of spectral properties of optical components used. The stability of the light source for use in the calibration of vacuum ultraviolet spectrographs and optical systems was investigated and found to be amenable to laboratory applications. The lamp was studied for a range of operating parameters; the results indicate that with appropriate peripheral instrumentation, the light source can be used as a secondary laboratory standard source when operated under preset controlled conditions. Absolute intensity measurements were recorded for the wavelengths 127.7, 158.0, 177.5, and 195.0 nm for a time period of over 1 month, and the measurements were found to be repeatable to within 11 percent.

  7. The Impact of Environmental Light Intensity on Experimental Tumor Growth.

    PubMed

    Suckow, Mark A; Wolter, William R; Duffield, Giles E

    2017-09-01

    Cancer research requires for consistent models that minimize environmental variables. Within the typical laboratory animal housing facility, animals may be exposed to varying intensities of light as a result of cage type, cage position, light source, and other factors; however, studies evaluating the differential effect of light intensity during the light phase on tumor growth are lacking. The effect of cage face light intensity, as determined by cage rack position was evaluated with two tumor models using the C57Bl/6NHsd mouse and transplantable B16F10 melanoma cells or Lewis lung carcinoma (LLC) cells. Animals were housed in individually-ventilated cages placed at the top, middle, or bottom of the rack in a diagonal pattern so that the top cage was closest to the ceiling light source, and cage face light intensity was measured. Following a two-week acclimation period at the assigned cage position, animals were subcutaneously administered either 1.3×10 6 B16F10 melanoma cells or 2.5×10 5 Lewis lung carcinoma cells. Weights of excised tumors were measured following euthanasia 18 days (melanoma) or 21 days (LCC) after tumor cell administration. Cage face light intensity was significantly different depending on the location of the cage, with cages closest to the light source have the greatest intensity. Mean tumor weights were significantly less (p<0.001 for melanoma; p≤0.01 for LCC) in middle light intensity mice compared to high and low light intensity mice. The environmental light intensity to which experimental animals are exposed may vary markedly with cage location and can significantly influence experimental tumor growth, thus supporting the idea that light intensity should be controlled as an experimental variable for animals used in cancer research. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  8. Light intensity modulates corneal power and refraction in the chick eye exposed to continuous light.

    PubMed

    Cohen, Yuval; Belkin, Michael; Yehezkel, Oren; Avni, Isaac; Polat, Uri

    2008-09-01

    Continuous exposure of chicks to light was shown to result in severe hyperopia, accompanied by anterior segment changes, such as severe corneal flattening. Since rearing chicks in complete darkness results only in mild hyperopia and minor changes in corneal curvature, we hypothesized that light intensity may play a role in the development of refractive changes under continuous light illumination. To test this hypothesis, we examined the effects of rearing chicks under various continuous light intensities. More specifically, we investigated the refractive parameters of the chicks' eyes, and avoided light cycling effects on ocular development. To this end, thirty-eight chicks were reared under 24-h incandescent illumination, at three different light intensities: 10,000 lux (n=13), 500 lux (n=12), and 50 lux (n=13). Their eyes underwent repeated retinoscopy, keratometry, and ultrasound biometry, as well as caliper measurements of enucleated eyes. Both refraction and corneal refractive power were found to be correlated with light intensity. On day 90 after hatching, exposure to light intensities of 10,000, 500, and 50 lux resulted in hyperopia of +11.97+/-3.7 (mean+/-SD) +7.9+/-4.08 and +0.63+/-3.61 diopters (D), respectively. Under those intensities, corneal refractive power was 46.10+/-3.62, 49.72+/-4.16, and 56.88+/-4.92D, respectively. Axial length did not differ significantly among the groups. The vitreous chamber was significantly deeper in the high than in the low-intensity groups. Thus, during the early life of chicks exposed to continuous lighting, light intensity affects the vitreous chamber depth as well as the anterior segment parameters, most notably the cornea. The higher the intensity, the more severe was the corneal flattening observed and the hyperopia that developed, whereas continuous illumination at low intensities resulted in emmetropia. Thus, light intensity is an important factor that should be taken into account when studying refractive

  9. Perceiving the Intensity of Light

    ERIC Educational Resources Information Center

    Purves, Dale; Williams, S. Mark; Nundy, Surajit; Lotto, R. Beau

    2004-01-01

    The relationship between luminance (i.e., the photometric intensity of light) and its perception (i.e., sensations of lightness or brightness) has long been a puzzle. In addition to the mystery of why these perceptual qualities do not scale with luminance in any simple way, "illusions" such as simultaneous brightness contrast, Mach bands,…

  10. Abnormal environmental light exposure in the intensive care environment.

    PubMed

    Fan, Emily P; Abbott, Sabra M; Reid, Kathryn J; Zee, Phyllis C; Maas, Matthew B

    2017-08-01

    We sought to characterize ambient light exposure in the intensive care unit (ICU) environment to identify patterns of light exposure relevant to circadian regulation. A light monitor was affixed to subjects' bed at eye level in a modern intensive care unit and continuously recorded illuminescence for at least 24h per subject. Blood was sampled hourly and measured for plasma melatonin. Subjects underwent hourly vital sign and bedside neurologic assessments. Care protocols and the ICU environment were not modified for the study. A total of 67,324 30-second epochs of light data were collected from 17 subjects. Light intensity peaked in the late morning, median 64.1 (interquartile range 19.7-138.7) lux. The 75th percentile of light intensity exceeded 100lx only between 9AM and noon, and never exceeded 150lx. There was no correlation between melatonin amplitude and daytime, nighttime or total light exposure (Spearman's correlation coefficients all <0.2 and p>0.5). Patients' environmental light exposure in the intensive care unit is consistently low and follows a diurnal pattern. No effect of nighttime light exposure was observed on melatonin secretion. Inadequate daytime light exposure in the ICU may contribute to abnormal circadian rhythms. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Light Intensity Physical Activity Trial

    ClinicalTrials.gov

    2018-01-30

    Diabetes Mellitus; Physical Exercise; Light Intensity Physical Activity; Arterial Stiffness; Aortic Stiffness; Pulse Wave Velocity; Type2 Diabetes; Sedentary Lifestyle; Artery Disease; Physical Activity

  12. 14 CFR 29.1389 - Position light distribution and intensities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... be provided by new equipment with light covers and color filters in place. Intensities must be... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Position light distribution and intensities... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Lights § 29.1389...

  13. 14 CFR 29.1389 - Position light distribution and intensities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... be provided by new equipment with light covers and color filters in place. Intensities must be... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Position light distribution and intensities... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Lights § 29.1389...

  14. 14 CFR 29.1389 - Position light distribution and intensities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... be provided by new equipment with light covers and color filters in place. Intensities must be... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Position light distribution and intensities... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Lights § 29.1389...

  15. 14 CFR 29.1389 - Position light distribution and intensities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... be provided by new equipment with light covers and color filters in place. Intensities must be... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Position light distribution and intensities... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Lights § 29.1389...

  16. Absolute intensity measurements of impurity emissions in a shock tunnel and their consequences for laser-induced fluorescence experiments

    NASA Technical Reports Server (NTRS)

    Palma, P. C.; Houwing, A. F. P.; Sandeman, R. J.

    1993-01-01

    Absolute intensity measurements of impurity emissions in a shock tunnel nozzle flow are presented. The impurity emission intensities were measured with a photomultiplier and optical multichannel analyzer and calibrated against an intensity standard. The various metallic contaminants were identified and their intensities measured in the spectral regions 290 to 330 nm and 375 to 385 nm. A comparison with calculated fluorescence intensities for predissociated laser-induced fluorescence signals is made. It is found that the emission background is negligible for most fluorescence experiments.

  17. 14 CFR 25.1389 - Position light distribution and intensities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... provided by new equipment with light covers and color filters in place. Intensities must be determined with... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Position light distribution and intensities... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1389 Position...

  18. 14 CFR 27.1389 - Position light distribution and intensities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... provided by new equipment with light covers and color filters in place. Intensities must be determined with... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Position light distribution and intensities... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Lights § 27.1389 Position...

  19. 14 CFR 27.1389 - Position light distribution and intensities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... provided by new equipment with light covers and color filters in place. Intensities must be determined with... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Position light distribution and intensities... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Lights § 27.1389 Position...

  20. 14 CFR 25.1389 - Position light distribution and intensities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... provided by new equipment with light covers and color filters in place. Intensities must be determined with... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Position light distribution and intensities... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1389 Position...

  1. 14 CFR 27.1389 - Position light distribution and intensities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... provided by new equipment with light covers and color filters in place. Intensities must be determined with... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Position light distribution and intensities... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Lights § 27.1389 Position...

  2. 14 CFR 25.1389 - Position light distribution and intensities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... provided by new equipment with light covers and color filters in place. Intensities must be determined with... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Position light distribution and intensities... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1389 Position...

  3. 14 CFR 25.1389 - Position light distribution and intensities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... provided by new equipment with light covers and color filters in place. Intensities must be determined with... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Position light distribution and intensities... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1389 Position...

  4. 14 CFR 27.1389 - Position light distribution and intensities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... provided by new equipment with light covers and color filters in place. Intensities must be determined with... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Position light distribution and intensities... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Lights § 27.1389 Position...

  5. Performance of Arrowroot (Marantha arundinacea) in various light intensities

    NASA Astrophysics Data System (ADS)

    Oktafani, M. B.; Supriyono; Budiastuti, MTh S.; Purnomo, D.

    2018-03-01

    Arrowroot (Marantha arundinacea) is one of the potential food crops to support food security programs. Light intensity is one of the important factors for plant growth. Arrowroot cultivation technology still need further development. Traditionally, arrowroot grows wild under canopy without intentisification of cultivating which have low productivity. The purpose of research was to investigate the suitable light intensity for arrowroot. The experiment was conducted at Jumantono as Experimental Field of Faculty of Agricultural, University of Sebelas Maret Surakarta located in Karanganyar, from March to September 2016. The experiment used a complete randomized block design (CRBD) of light intensity level there are 27400 lux (full sun light), 18900 lux (shaded 31%), 13500 lux (shaded 51%) and 7400 lux (shaded 72%). Each treatment was replicated six times so there were 24 experimental units. The results showed that arrowroot is a low light adaptive plant. Arrowroot under the light intensity 7400 lux (27% full light), the number of leaves and tillers is not significantly different than under full light, although the plant is higher. The highest tuber diameter and length were 1.91 and 25.06 cm, respectively, and tuber weight reached 607.5-651.67 g per plant.

  6. Wide-field absolute transverse blood flow velocity mapping in vessel centerline

    NASA Astrophysics Data System (ADS)

    Wu, Nanshou; Wang, Lei; Zhu, Bifeng; Guan, Caizhong; Wang, Mingyi; Han, Dingan; Tan, Haishu; Zeng, Yaguang

    2018-02-01

    We propose a wide-field absolute transverse blood flow velocity measurement method in vessel centerline based on absorption intensity fluctuation modulation effect. The difference between the light absorption capacities of red blood cells and background tissue under low-coherence illumination is utilized to realize the instantaneous and average wide-field optical angiography images. The absolute fuzzy connection algorithm is used for vessel centerline extraction from the average wide-field optical angiography. The absolute transverse velocity in the vessel centerline is then measured by a cross-correlation analysis according to instantaneous modulation depth signal. The proposed method promises to contribute to the treatment of diseases, such as those related to anemia or thrombosis.

  7. Intensity output and effectiveness of light curing units in dental offices.

    PubMed

    Omidi, Baharan-Ranjbar; Gosili, Armin; Jaber-Ansari, Mona; Mahdkhah, Ailin

    2018-06-01

    The aims of the study were measuring the light intensity of light curing units used in Qazvin's dental offices, determining the relationship between the clinical age of these units and their light intensity, and identifying the reasons for repairing them. In this cross-sectional study, the output intensity of 95 light curing devices was evaluated using a radiometer. The average output intensity was divided up into four categories (less than 200, 200-299, 300-500, and more than 500 mW/cm2). In addition, a questionnaire was designed to obtain information mainly about the type, clinical age, and frequency of maintenance of the units and the reasons for fixing them. Data were analyzed using Kolmogorov-Smirnov, chi-squared, and t-tests ( p < 0.05) on SPSS 24. A total of 95 light curing units were examined, with 61 (64.2%) of them being of the LED type and 34 (35.8%) of the QTH type. While average light intensity in LED units was significantly higher than in QTH devices, the two device types were not significantly different regarding desirable light intensity (i.e., ≥ 300 mw/cm2). A negative correlation was observed between clinical age and light intensity. In addition, bulb replacement in QTH devices was over three times as much as in LED units. Also, repairing QTHs was more than twice as much frequent as fixing LEDs. The most common reason for repair was the breakage of the tip of the device. The light intensity of LED units is significantly higher than that of QTH devices, and the frequency of repairing in QTHs was significantly more than in LEDs. Furthermore, light intensity decreases with aging, and dentists should regularly monitor the conditions of light units. Key words: Light curing unit, radiometer, light intensity, dental equipment, dental offices.

  8. Effects of different light intensities in the morning on dim light melatonin onset.

    PubMed

    Kozaki, Tomoaki; Toda, Naohiro; Noguchi, Hiroki; Yasukouchi, Akira

    2011-01-01

    The present study evaluated the effects of exposure to light intensity in the morning on dim light melatonin onset (DLMO). The tested light intensities were 750 lux, 150 lux, 3000 lux, 6000 lux and 12,000 lux (horizontal illuminance at cornea), using commercial 5000 K fluorescent lamps. Eleven healthy males aged 21-31 participated in 2-day experiments for each light condition. On the first experimental day (day 1), subjects were exposed to dim light (<30 lux) for 3 h in the morning (09:00-12:00). On the same day, saliva samples were taken in dim light (<30 lux) every 30 min from 21:00 to 01:00 to determine the DLMO phase. The subjects were allowed to sleep from 01:00 to 08:00. On the second experimental day (day 2), the subjects were exposed to experimental light conditions for 3 h in the morning. The experimental schedule after light exposure was the same as on day 1. On comparing day 2 with day 1, significant phase advances of DLMO were obtained at 3000 lux, 6000 lux and 12,000 lux. These findings indicate that exposure to a necessary intensity from an ordinary light source, such as a fluorescent lamp, in the morning within one day affects melatonin secretion.

  9. Techniques for optically compressing light intensity ranges

    DOEpatents

    Rushford, Michael C.

    1989-01-01

    A pin hole camera assembly for use in viewing an object having a relatively large light intensity range, for example a crucible containing molten uranium in an atomic vapor laser isotope separator (AVLIS) system is disclosed herein. The assembly includes means for optically compressing the light intensity range appearing at its input sufficient to make it receivable and decipherable by a standard video camera. A number of different means for compressing the intensity range are disclosed. These include the use of photogray glass, the use of a pair of interference filters, and the utilization of a new liquid crystal notch filter in combination with an interference filter.

  10. Techniques for optically compressing light intensity ranges

    DOEpatents

    Rushford, M.C.

    1989-03-28

    A pin hole camera assembly for use in viewing an object having a relatively large light intensity range, for example a crucible containing molten uranium in an atomic vapor laser isotope separator (AVLIS) system is disclosed herein. The assembly includes means for optically compressing the light intensity range appearing at its input sufficient to make it receivable and decipherable by a standard video camera. A number of different means for compressing the intensity range are disclosed. These include the use of photogray glass, the use of a pair of interference filters, and the utilization of a new liquid crystal notch filter in combination with an interference filter. 18 figs.

  11. Effects of laryngoscope handle light source on the light intensity from disposable laryngoscope blades.

    PubMed

    Milne, A D; Brousseau, P A; Brousseau, C A

    2014-12-01

    A bench-top study was performed to assess the effects of different laryngoscope handles on the light intensity delivered from disposable metal or plastic laryngoscope blades. The light intensity from both the handle light sources themselves and the combined handle and laryngoscope blade sets was measured using a custom-designed testing system and light meter. Five samples of each disposable blade type were tested and compared with a standard re-usable stainless steel blade using three different handle/light sources (Vital Signs LED, Heine 2.5 V Xenon and 3.5 V Xenon). The light intensity delivered by the disposable blades ranged from 790 to 3846 lux for the different handle types. Overall, the 3.5 V Heine handle delivered the highest light output (p < 0.007) in comparison with the other handles. For the disposable blades, the overall light output was significantly higher from the plastic than the metal blades (p < 0.001). © 2014 The Association of Anaesthetists of Great Britain and Ireland.

  12. 1998 UBV Light Curves of Eclipsing Binary AI Draconis and Absolute Parameters

    NASA Astrophysics Data System (ADS)

    Jassur, D. M. Z.; Khaledian, M. S.; Kermani, M. H.

    New UBV photometry of Algol-Type eclipsing binary star AI Dra and the absolute physical parameters of this system have been presented. The light curve analysis carried out by the method of differential corrections indicates that both components are inside their Roche-Lobes. From combining the photometric solution with spectroscopic data obtained from velocity curve analysis, it has been found that the system consist of a main sequence primary and an evolved (subgiant) secondary.

  13. Absolutely relative or relatively absolute: violations of value invariance in human decision making.

    PubMed

    Teodorescu, Andrei R; Moran, Rani; Usher, Marius

    2016-02-01

    Making decisions based on relative rather than absolute information processing is tied to choice optimality via the accumulation of evidence differences and to canonical neural processing via accumulation of evidence ratios. These theoretical frameworks predict invariance of decision latencies to absolute intensities that maintain differences and ratios, respectively. While information about the absolute values of the choice alternatives is not necessary for choosing the best alternative, it may nevertheless hold valuable information about the context of the decision. To test the sensitivity of human decision making to absolute values, we manipulated the intensities of brightness stimuli pairs while preserving either their differences or their ratios. Although asked to choose the brighter alternative relative to the other, participants responded faster to higher absolute values. Thus, our results provide empirical evidence for human sensitivity to task irrelevant absolute values indicating a hard-wired mechanism that precedes executive control. Computational investigations of several modelling architectures reveal two alternative accounts for this phenomenon, which combine absolute and relative processing. One account involves accumulation of differences with activation dependent processing noise and the other emerges from accumulation of absolute values subject to the temporal dynamics of lateral inhibition. The potential adaptive role of such choice mechanisms is discussed.

  14. Redwood seedling responses to light patterns and intensities

    Treesearch

    Ronald W. Boldenow; Joe R. McBride

    2017-01-01

    Coast redwood (Sequoia sempervirens (D. Don) Endl.) seedlings were grown from seed in controlled environments with 16 hour photoperiods using three light patterns that mimicked full shade (constant light level), intermittent high light such as long duration sun flecks (low light with 15 minutes of intense light every 2 hours), and large...

  15. Absolute laser-intensity measurement and online monitor calibration using a calorimeter at a soft X-ray free-electron laser beamline in SACLA

    NASA Astrophysics Data System (ADS)

    Tanaka, Takahiro; Kato, Masahiro; Saito, Norio; Owada, Shigeki; Tono, Kensuke; Yabashi, Makina; Ishikawa, Tetsuya

    2018-06-01

    This paper reports measurement of the absolute intensity of free-electron laser (FEL) and calibration of online intensity monitors for a brand-new FEL beamline BL1 at SPring-8 Angstrom Compact free-electron LAser (SACLA) in Japan. To measure the absolute intensity of FEL, we used a room-temperature calorimeter originally developed for FELs in the hard X-ray range. By using the calorimeter, we calibrated online intensity monitors of BL1, gas monitors (GMs), based on the photoionization of argon gas, in the photon energy range from 25 eV to 150 eV. A good correlation between signals obtained from the calorimeter and GMs was observed in the pulse energy range from 1 μJ to 100 μJ, where the upper limit is nearly equal to the maximum pulse energy at BL1. Moreover, the calibration result of the GMs, measured in terms of the spectral responsivity, demonstrates a characteristic photon-energy dependence owing to the occurrence of the Cooper minimum in the total ionization cross-section of argon gas. These results validate the feasibility of employing the room-temperature calorimeter in the measurement of absolute intensity of FELs over the specified photon energy range.

  16. Enhancement of autonomic and psychomotor arousal by exposures to blue wavelength light: importance of both absolute and relative contents of melanopic component.

    PubMed

    Yuda, Emi; Ogasawara, Hiroki; Yoshida, Yutaka; Hayano, Junichiro

    2017-01-31

    Blue light containing rich melanopsin-stimulating (melanopic) component has been reported to enhance arousal level, but it is unclear whether the determinant of the effects is the absolute or relative content of melanopic component. We compared the autonomic and psychomotor arousal effects of melanopic-enriched blue light of organic light-emitting diode (OLED) with those of OLED lights with lesser absolute amount of melanopic component (green light) and with greater absolute but lesser relative content (white light). Using a ceiling light consisting of 120 panels (55 × 55 mm square) of OLED modules with adjustable color and brightness, we examined the effects of blue, green, and white lights (melanopic photon flux densities, 0.23, 0.14, and 0.38 μmol/m 2 /s and its relative content ratios, 72, 17, and 14%, respectively) on heart rate variability (HRV) during exposures and on the performance of psychomotor vigilance test (PVT) after exposures in ten healthy subjects with normal color vision. For each of the three colors, five consecutive 10-min sessions of light exposures were performed in the supine position, interleaved by four 10-min intervals during which 5-min PVT was performed under usual fluorescent light in sitting position. Low-frequency (LF, 0.04-0.15 Hz) and high-frequency (HF, 0.15-0.40 Hz) power and LF-to-HF ratio (LF/HF) of HRV during light exposures and reaction time (RT) and minor lapse (RT >500 ms) of PVT were analyzed. Heart rate was higher and the HF power reflecting autonomic resting was lower during exposures to the blue light than the green and white lights, while LF/HF did not differ significantly. Also, the number of minor lapse and the variation of reaction time reflecting decreased vigilance were lower after exposures to the blue light than the green light. The effects of blue OLED light for maintaining autonomic and psychomotor arousal levels depend on both absolute and relative contents of melanopic component in the light.

  17. Light intensity modulation in phototherapy

    NASA Astrophysics Data System (ADS)

    Lukyanovich, P. A.; Zon, B. A.; Kunin, A. A.; Pankova, S. N.

    2015-04-01

    A hypothesis that blocking ATP synthesis is one of the main causes of the stimulating effect is considered based on analysis of the primary photostimulation mechanisms. The light radiation intensity modulation is substantiated and the estimates of such modulation parameters are made. An explanation is offered to the stimulation efficiency decrease phenomenon at the increase of the radiation dose during the therapy. The results of clinical research of the medical treatment in preventive dentistry are presented depending on the spectrum and parameters of the light flux modulation.

  18. Early Birds by Light at Night: Effects of Light Color and Intensity on Daily Activity Patterns in Blue Tits.

    PubMed

    de Jong, Maaike; Caro, Samuel P; Gienapp, Phillip; Spoelstra, Kamiel; Visser, Marcel E

    2017-08-01

    Artificial light at night disturbs the daily rhythms of many organisms. To what extent this disturbance depends on the intensity and spectral composition of light remain obscure. Here, we measured daily activity patterns of captive blue tits ( Cyanistes caeruleus) exposed to similar intensities of green, red, or white light at night. Birds advanced their onset of activity in the morning under all light colors but more under red and white light than under green light. Offset of activity was slightly delayed in all light colors. The total activity over a 24-h period did not change but birds moved a part of their daily activity into the night. Since the effect of red and white lights are comparable, we tested the influence of light intensity in a follow-up experiment, where we compared the activity of the birds under different intensities of green and white light only. While in the higher range of intensities, the effects of white and green light were comparable; at lower intensities, green light had a less disturbing effect as compared with white light on daily rhythms in blue tits. Our results show that the extent of this disturbance can be mitigated by modulating the spectral characteristics and intensity of outdoor lighting, which is now feasible through the use of LED lighting.

  19. On the Intensity Profile of Electric Lamps and Light Bulbs

    ERIC Educational Resources Information Center

    Bacalla, Xavier; Salumbides, Edcel John

    2013-01-01

    We demonstrate that the time profile of the light intensity from domestic lighting sources exhibits simple yet interesting properties that foster lively student discussions. We monitor the light intensity of an industrial fluorescent lamp (also known as TL) and an incandescent bulb using a photodetector connected to an oscilloscope. The light…

  20. High intensity portable fluorescent light

    NASA Technical Reports Server (NTRS)

    Kendall, F. B.

    1972-01-01

    Eight high intensity portable fluorescent lights were produced. Three prototype lights were also produced, two of which were subsequently updated to the physical and operational configuration of the qualification and flight units. Positioning of lamp apertures and reflectors in these lights is such that the light is concentrated and intensified in a specific pattern rather than widely diffused. Indium amalgam control of mercury vapor pressure in the lamp gives high output at lamp ambient temperatures up to 105 C. A small amount of amalgam applied to each electrode stem helps to obtain fast warm-up. Shrinking a Teflon sleeve on the tube and potting metal caps on each end of the lamp minimizes dispersion of mercury vapor and glass particles in the event of accidental lamp breakage. Operation at 20 kHz allows the lamps to consume more power than at low frequency, thus increasing their light output and raising their efficiency. When used to expose color photographic film, light from the lamps produces results approximately equal to sunlight.

  1. Light-intensity modulator withstands high heat fluxes

    NASA Technical Reports Server (NTRS)

    Maples, H. G.; Strass, H. K.

    1966-01-01

    Mechanism modulates and controls the intensity of luminous radiation in light beams associated with high-intensity heat flux. This modulator incorporates two fluid-cooled, externally grooved, contracting metal cylinders which when rotated about their longitudinal axes present a circular aperture of varying size depending on the degree of rotation.

  2. Light-Irradiation Wavelength and Intensity Changes Influence Aflatoxin Synthesis in Fungi

    PubMed Central

    Suzuki, Tadahiro

    2018-01-01

    Fungi respond to light irradiation by forming conidia and occasionally synthesizing mycotoxins. Several light wavelengths, such as blue and red, affect the latter. However, the relationship between light irradiation and mycotoxin synthesis varies depending on the fungal species or strain. This study focused on aflatoxin (AF), which is a mycotoxin, and the types of light irradiation that increase AF synthesis. Light-irradiation tests using the visible region indicated that blue wavelengths in the lower 500 nm region promoted AF synthesis. In contrast, red wavelengths of 660 nm resulted in limited significant changes compared with dark conditions. Irradiation tests with different intensity levels indicated that a low light intensity increased AF synthesis. For one fungal strain, light irradiation decreased the AF synthesis under all wavelength conditions. However, the decrease was mitigated by 525 nm low intensity irradiation. Thus, blue-green low intensity irradiation may increase AF synthesis in fungi. PMID:29304012

  3. Daytime light intensity affects seasonal timing via changes in the nocturnal melatonin levels

    NASA Astrophysics Data System (ADS)

    Kumar, Vinod; Rani, Sangeeta; Malik, Shalie; Trivedi, Amit K.; Schwabl, Ingrid; Helm, Barbara; Gwinner, Eberhard

    2007-08-01

    Daytime light intensity can affect the photoperiodic regulation of the reproductive cycle in birds. The actual way by which light intensity information is transduced is, however, unknown. We postulate that transduction of the light intensity information is mediated by changes in the pattern of melatonin secretion. This study, therefore, investigated the effects of high and low daytime light intensities on the daily melatonin rhythm of Afro-tropical stonechats ( Saxicola torquata axillaris) in which seasonal changes in daytime light intensity act as a zeitgeber of the circannual rhythms controlling annual reproduction and molt. Stonechats were subjected to light conditions simulated as closely as possible to native conditions near the equator. Photoperiod was held constant at 12.25 h of light and 11.75 h of darkness per day. At intervals of 2.5 to 3.5 weeks, daytime light intensity was changed from bright (12,000 lux at one and 2,000 lux at the other perch) to dim (1,600 lux at one and 250 lux at the other perch) and back to the original bright light. Daily plasma melatonin profiles showed that they were linked with changes in daytime light intensity: Nighttime peak and total nocturnal levels were altered when transitions between light conditions were made, and these changes were significant when light intensity was changed from dim to bright. We suggest that daytime light intensity could affect seasonal timing via changes in melatonin profiles.

  4. Disruptive effects of light pollution on sleep in free-living birds: Season and/or light intensity-dependent?

    PubMed

    Raap, Thomas; Sun, Jiachen; Pinxten, Rianne; Eens, Marcel

    2017-11-01

    Light pollution or artificial light at night (ALAN) is an increasing anthropogenic environmental pollutant posing an important potential threat for wildlife. Evidence of its effects on animal physiology and behaviour is accumulating. However, in order to effectively mitigate light pollution it is important to determine which factors contribute to the severity of effects of ALAN. In this experimental study we explored whether there are seasonal-dependent effects of ALAN on sleep in free-living great tits (Parus major), an important model species. Additionally, we looked at whether light intensity determined the severity of effects of ALAN on sleep. We therefore exposed animals to artificial light inside the nest box (3lx) in December (winter) and February (pre-breeding season). Results from February were compared with the results from a previous study in February, using a lower light intensity (1.6lx). We found little evidence for a season-dependent response. Effects of ALAN hardly differed between high and low light intensity. ALAN disrupted sleep with as main effect a decrease in sleep duration (≈-40min) as animals woke up earlier (≈-24min). However, compared to a natural dark situation sleep onset was delayed by high but not by low light intensity of ALAN. Our study underlines earlier found disruptive effects of ALAN on sleep of free-living animals. While we found no conclusive evidence for seasonal or light intensity-dependent effects of ALAN, additional experimental work using lower light intensities might show such differences. Examining potential management options is crucial in mitigating disruptive effects of light pollution, which will be an important focus for future studies. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. NIST Standard Reference Material 3600: Absolute Intensity Calibration Standard for Small-Angle X-ray Scattering

    DOE PAGES

    Allen, Andrew J.; Zhang, Fan; Kline, R. Joseph; ...

    2017-03-07

    The certification of a new standard reference material for small-angle scattering [NIST Standard Reference Material (SRM) 3600: Absolute Intensity Calibration Standard for Small-Angle X-ray Scattering (SAXS)], based on glassy carbon, is presented. Creation of this SRM relies on the intrinsic primary calibration capabilities of the ultra-small-angle X-ray scattering technique. This article describes how the intensity calibration has been achieved and validated in the certified Q range, Q = 0.008–0.25 Å –1, together with the purpose, use and availability of the SRM. The intensity calibration afforded by this robust and stable SRM should be applicable universally to all SAXS instruments thatmore » employ a transmission measurement geometry, working with a wide range of X-ray energies or wavelengths. As a result, the validation of the SRM SAXS intensity calibration using small-angle neutron scattering (SANS) is discussed, together with the prospects for including SANS in a future renewal certification.« less

  6. NIST Standard Reference Material 3600: Absolute Intensity Calibration Standard for Small-Angle X-ray Scattering

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Allen, Andrew J.; Zhang, Fan; Kline, R. Joseph

    The certification of a new standard reference material for small-angle scattering [NIST Standard Reference Material (SRM) 3600: Absolute Intensity Calibration Standard for Small-Angle X-ray Scattering (SAXS)], based on glassy carbon, is presented. Creation of this SRM relies on the intrinsic primary calibration capabilities of the ultra-small-angle X-ray scattering technique. This article describes how the intensity calibration has been achieved and validated in the certified Q range, Q = 0.008–0.25 Å –1, together with the purpose, use and availability of the SRM. The intensity calibration afforded by this robust and stable SRM should be applicable universally to all SAXS instruments thatmore » employ a transmission measurement geometry, working with a wide range of X-ray energies or wavelengths. As a result, the validation of the SRM SAXS intensity calibration using small-angle neutron scattering (SANS) is discussed, together with the prospects for including SANS in a future renewal certification.« less

  7. NIST Standard Reference Material 3600: Absolute Intensity Calibration Standard for Small-Angle X-ray Scattering.

    PubMed

    Allen, Andrew J; Zhang, Fan; Kline, R Joseph; Guthrie, William F; Ilavsky, Jan

    2017-04-01

    The certification of a new standard reference material for small-angle scattering [NIST Standard Reference Material (SRM) 3600: Absolute Intensity Calibration Standard for Small-Angle X-ray Scattering (SAXS)], based on glassy carbon, is presented. Creation of this SRM relies on the intrinsic primary calibration capabilities of the ultra-small-angle X-ray scattering technique. This article describes how the intensity calibration has been achieved and validated in the certified Q range, Q = 0.008-0.25 Å -1 , together with the purpose, use and availability of the SRM. The intensity calibration afforded by this robust and stable SRM should be applicable universally to all SAXS instruments that employ a transmission measurement geometry, working with a wide range of X-ray energies or wavelengths. The validation of the SRM SAXS intensity calibration using small-angle neutron scattering (SANS) is discussed, together with the prospects for including SANS in a future renewal certification.

  8. Light-Induced Changes of the Circadian Clock of Humans: Increasing Duration is More Effective than Increasing Light Intensity

    PubMed Central

    Dewan, Karuna; Benloucif, Susan; Reid, Kathryn; Wolfe, Lisa F.; Zee, Phyllis C.

    2011-01-01

    Study Objectives: To evaluate the effect of increasing the intensity and/or duration of exposure on light-induced changes in the timing of the circadian clock of humans. Design: Multifactorial randomized controlled trial, between and within subject design Setting: General Clinical Research Center (GCRC) of an academic medical center Participants: 56 healthy young subjects (20-40 years of age) Interventions: Research subjects were admitted for 2 independent stays of 4 nights/3 days for treatment with bright or dim-light (randomized order) at a time known to induce phase delays in circadian timing. The intensity and duration of the bright light were determined by random assignment to one of 9 treatment conditions (duration of 1, 2, or 3 hours at 2000, 4000, or 8000 lux). Measurements and Results: Treatment-induced changes in the dim light melatonin onset (DLMO) and dim light melatonin offset (DLMOff) were measured from blood samples collected every 20-30 min throughout baseline and post-treatment nights. Comparison by multi-factor analysis of variance (ANOVA) of light-induced changes in the time of the circadian melatonin rhythm for the 9 conditions revealed that changing the duration of the light exposure from 1 to 3 h increased the magnitude of light-induced delays. In contrast, increasing from moderate (2,000 lux) to high (8,000 lux) intensity light did not alter the magnitude of phase delays of the circadian melatonin rhythm. Conclusions: Results from the present study suggest that for phototherapy of circadian rhythm sleep disorders in humans, a longer period of moderate intensity light may be more effective than a shorter exposure period of high intensity light. Citation: Dewan K; Benloucif S; Reid K; Wolfe LF; Zee PC. Light-induced changes of the circadian clock of humans: increasing duration is more effective than increasing light intensity. SLEEP 2011;34(5):593-599. PMID:21532952

  9. The effect of light intensity on image quality in endoscopic ear surgery.

    PubMed

    McCallum, R; McColl, J; Iyer, A

    2018-05-16

    Endoscopic ear surgery is a rapidly developing field with many advantages. But endoscopes can reach temperatures of over 110°C at the tip, raising safety concerns. Reducing the intensity of the light source reduces temperatures produced. However, quality of images at lower light intensities has not yet been studied. We set out to study the effect of light intensity on image quality in EES. Prospective study of patients undergoing EES from April to October 2016. Consecutive images of the same operative field at 10%, 30%, 50% and 100% light intensities were taken. Eight international experts were asked to each evaluate 100 anonymised, randomised images. District General Hospital. Twenty patients. Images were evaluated on a 5-point Likert scale (1 = significantly worse than average; 5 = significantly better than average) for detail of anatomy; colour contrast; overall quality; and suitability for operating. Mean scores for photographs at 10%, 30%, 50% and 100% light intensity were 3.22 (SD 0.93), 3.15 (SD 0.84), 3.08 (SD 0.88) and 3.10 (SD 0.86), respectively. In ANOVA models for the scores on each of the scales (anatomy, colour contrast, overall quality and suitability for operating), the effects of rater and patient were highly significant (P < .0005) but light intensity was non-significant (P = .34, .32, .21, .15, respectively). Images taken during surgery by our endoscope and operative camera have no loss of quality when taken at lower light intensities. We recommend the surgeon considers use of lower light intensities in endoscopic ear surgery. © 2018 John Wiley & Sons Ltd.

  10. 'In a dark place, we find ourselves': light intensity in critical care units.

    PubMed

    Durrington, Hannah J; Clark, Richard; Greer, Ruari; Martial, Franck P; Blaikley, John; Dark, Paul; Lucas, Robert J; Ray, David W

    2017-12-01

    Intensive care units provide specialised care for critically ill patients around the clock. However, intensive care unit patients have disrupted circadian rhythms. Furthermore, disrupted circadian rhythms are associated with worse outcome. As light is the most powerful 're-setter' of circadian rhythm, we measured light intensity on intensive care unit. Light intensity was low compared to daylight during the 'day'; frequent bright light interruptions occurred over 'night'. These findings are predicted to disrupt circadian rhythms and impair entrainment to external time. Bright lighting during daytime and black out masks at night might help maintain biological rhythms in critically ill patients and improve clinical outcomes.

  11. Revisiting Absolute Radio Backgrounds in Light of Juno Cruise Data

    NASA Astrophysics Data System (ADS)

    Chang, Tzu-Ching

    Radio backgrounds have played a critical role in recent progress in astronomy and cosmology. Major amongst them, the Cosmic Microwave Background (CMB) is currently our most precise window on the physics of the early universe. Both its near perfect blackbody spectrum and its angular fluctuations led to unique cosmological inferences. Beyond the CMB, radio backgrounds have offered golden insights to Galactic and extragalactic astrophysics. In this proposal, we take note of the recently released "cruise data" collected over five years by the MicroWave Radiometer (MWR) instrument on board the Juno planetary mission to construct new, unprecedented and well-characterized full-sky maps at 6 frequencies ranging from 0.6 to 22 GHz. We propose to generate, validate and release these full-sky maps and investigate their rich and unique astrophysical implications. In particular, we expect the use of Juno data to shed light on the "ARCADE excess" and lead to new insights on Galactic and extragalactic radio signals. Over the past several years, evidence indicating the existence of a significant isotropic radio background has been hinted at by a number of instruments. In 2011, the Absolute Radiometer for Cosmology, Astrophysics and Diffuse Emission (ARCADE 2) collaboration reported measurements of the absolute sky temperature at a number of frequencies between 3 and 90 GHz (Fixsen et al. 2011). While these measurements are dominated by the CMB at frequencies above several GHz, they reveal the presence of significant excess power at the lowest measured frequencies (Seiffert et al. 2011). This conclusion is strengthened by a number of observations at lower frequencies, reported at 22 MHz, 45 MHz, 408 MHz and 1.42 GHz: the emission observed by each of these groups appears to be in significant excess to what can be attributed to Galactic emission, or to unresolved members of known extragalactic radio source populations. In addition, it appears to be anomalously spatially smooth to be

  12. Dark Light, Rod Saturation, and the Absolute and Incremental Sensitivity of Mouse Cone Vision

    PubMed Central

    Naarendorp, Frank; Esdaille, Tricia M.; Banden, Serenity M.; Andrews-Labenski, John; Gross, Owen P.; Pugh, Edward N.

    2012-01-01

    Visual thresholds of mice for the detection of small, brief targets were measured with a novel behavioral methodology in the dark and in the presence of adapting lights spanning ∼8 log10 units of intensity. To help dissect the contributions of rod and cone pathways, both wild-type mice and mice lacking rod (Gnat1−/−) or cone (Gnat2cpfl3) function were studied. Overall, the visual sensitivity of mice was found to be remarkably similar to that of the human peripheral retina. Rod absolute threshold corresponded to 12-15 isomerized pigment molecules (R*) in image fields of 800 to 3000 rods. Rod “dark light” (intrinsic retinal noise in darkness) corresponded to that estimated previously from single-cell recordings, 0.012R*s−1rod−1, indicating that spontaneous thermalisomerizations are responsible. Psychophysical rod saturation was measured for the first time in a nonhman species and found to be very similar to that of the human rod monochromat. Cone threshold corresponded to ∼5 R* cone−1 in an image field of 280 cones. Cone dark light was equivalent to ∼5000 R*s−1 cone−1, consistent with primate single-cell data but 100-fold higher than predicted by recent measurements of the rate of thermal isomerization of mouse cone opsins, indicating that nonopsin sources of noise determine cone threshold. The new, fully automated behavioral method is based on the ability of mice to learn to interrupt spontaneous wheel running on the presentation of a visual cue and provides an efficient and highly reliable means of examining visual function in naturally behaving normal and mutant mice. PMID:20844144

  13. Accuracy of intensity and inclinometer output of three activity monitors for identification of sedentary behavior and light-intensity activity.

    PubMed

    Carr, Lucas J; Mahar, Matthew T

    2012-01-01

    Purpose. To examine the accuracy of intensity and inclinometer output of three physical activity monitors during various sedentary and light-intensity activities. Methods. Thirty-six participants wore three physical activity monitors (ActiGraph GT1M, ActiGraph GT3X+, and StepWatch) while completing sedentary (lying, sitting watching television, sitting using computer, and standing still) light (walking 1.0 mph, pedaling 7.0 mph, pedaling 15.0 mph) intensity activities under controlled settings. Accuracy for correctly categorizing intensity was assessed for each monitor and threshold. Accuracy of the GT3X+ inclinometer function (GT3X+Incl) for correctly identifying anatomical position was also assessed. Percentage agreement between direct observation and the monitor recorded time spent in sedentary behavior and light intensity was examined. Results. All monitors using all thresholds accurately identified over 80% of sedentary behaviors and 60% of light-intensity walking time based on intensity output. The StepWatch was the most accurate in detecting pedaling time but unable to detect pedal workload. The GT3X+Incl accurately identified anatomical position during 70% of all activities but demonstrated limitations in discriminating between activities of differing intensity. Conclusions. Our findings suggest that all three monitors accurately measure most sedentary and light-intensity activities although choice of monitors should be based on study-specific needs.

  14. Infrared mapping of ultrasound fields generated by medical transducers: Feasibility of determining absolute intensity levels

    PubMed Central

    Khokhlova, Vera A.; Shmeleva, Svetlana M.; Gavrilov, Leonid R.; Martin, Eleanor; Sadhoo, Neelaksh; Shaw, Adam

    2013-01-01

    Considerable progress has been achieved in the use of infrared (IR) techniques for qualitative mapping of acoustic fields of high intensity focused ultrasound (HIFU) transducers. The authors have previously developed and demonstrated a method based on IR camera measurement of the temperature rise induced in an absorber less than 2 mm thick by ultrasonic bursts of less than 1 s duration. The goal of this paper was to make the method more quantitative and estimate the absolute intensity distributions by determining an overall calibration factor for the absorber and camera system. The implemented approach involved correlating the temperature rise measured in an absorber using an IR camera with the pressure distribution measured in water using a hydrophone. The measurements were conducted for two HIFU transducers and a flat physiotherapy transducer of 1 MHz frequency. Corresponding correction factors between the free field intensity and temperature were obtained and allowed the conversion of temperature images to intensity distributions. The system described here was able to map in good detail focused and unfocused ultrasound fields with sub-millimeter structure and with local time average intensity from below 0.1 W/cm2 to at least 50 W/cm2. Significantly higher intensities could be measured simply by reducing the duty cycle. PMID:23927199

  15. Infrared mapping of ultrasound fields generated by medical transducers: feasibility of determining absolute intensity levels.

    PubMed

    Khokhlova, Vera A; Shmeleva, Svetlana M; Gavrilov, Leonid R; Martin, Eleanor; Sadhoo, Neelaksh; Shaw, Adam

    2013-08-01

    Considerable progress has been achieved in the use of infrared (IR) techniques for qualitative mapping of acoustic fields of high intensity focused ultrasound (HIFU) transducers. The authors have previously developed and demonstrated a method based on IR camera measurement of the temperature rise induced in an absorber less than 2 mm thick by ultrasonic bursts of less than 1 s duration. The goal of this paper was to make the method more quantitative and estimate the absolute intensity distributions by determining an overall calibration factor for the absorber and camera system. The implemented approach involved correlating the temperature rise measured in an absorber using an IR camera with the pressure distribution measured in water using a hydrophone. The measurements were conducted for two HIFU transducers and a flat physiotherapy transducer of 1 MHz frequency. Corresponding correction factors between the free field intensity and temperature were obtained and allowed the conversion of temperature images to intensity distributions. The system described here was able to map in good detail focused and unfocused ultrasound fields with sub-millimeter structure and with local time average intensity from below 0.1 W/cm(2) to at least 50 W/cm(2). Significantly higher intensities could be measured simply by reducing the duty cycle.

  16. Light intensity and the oestrous cycle in albino and normally pigmented mice.

    PubMed

    Donnelly, H; Saibaba, P

    1993-10-01

    The effects of light intensity (15-20 lux & 220-290 lux) on the oestrous cycle of albino and normally pigmented mice were examined. The oestrous cycle of both types of mice was shorter at the lower intensity but the difference was significant only with the black mice. The proportion of albino mice from which embryos were recovered was significantly smaller than the proportion of black mice at 15-20 lux but not at 220-290 lux. No significant differences due to strain or light intensity were found in the number of embryos recovered. We conclude that pigmented mice respond in the same way as albino mice to changes in light intensity within the range normally found in laboratory animal accommodation. That is, increased light intensity prolongs the oestrous cycle and the period of vaginal cornification.

  17. Characteristic Analysis Light Intensity Sensor Based On Plastic Optical Fiber At Various Configuration

    NASA Astrophysics Data System (ADS)

    Arifin, A.; Lusiana; Yunus, Muhammad; Dewang, Syamsir

    2018-03-01

    This research discusses the light intensity sensor based on plastic optical fiber. This light intensity sensor is made of plastic optical fiber consisting of two types, namely which is cladding and without cladding. Plastic optical fiber used multi-mode step-index type made of polymethyl metacrylate (PMMA). The infrared LED emits light into the optical fiber of the plastic and is subsequently received by the phototransistor to be converted to an electric voltage. The sensor configuration is made with three models: straight configuration, U configuration and gamma configuration with cladding and without cladding. The measured light source uses a 30 Watt high power LED with a light intensity of 0 to 10 Klux. The measured light intensity will affect the propagation of light inside the optical fiber sensor. The greater the intensity of the measured light, the greater the output voltage that is read on the computer. The results showed that the best optical fiber sensor characteristics were obtained in U configuration. Sensors with U-configuration without cladding had the best sensitivity and resolution values of 0.0307 volts/Klux and 0.0326 Klux. The advantages of this measuring light intensity based on the plastic optical fiber instrument are simple, easy-to-make operational systems, low cost, high sensitivity and resolution.

  18. Plants Actively Avoid State Transitions upon Changes in Light Intensity: Role of Light-Harvesting Complex II Protein Dephosphorylation in High Light1[OPEN

    PubMed Central

    Suorsa, Marjaana; Rantala, Marjaana; Aro, Eva-Mari

    2015-01-01

    Photosystem II (PSII) core and light-harvesting complex II (LHCII) proteins in plant chloroplasts undergo reversible phosphorylation upon changes in light intensity (being under control of redox-regulated STN7 and STN8 kinases and TAP38/PPH1 and PSII core phosphatases). Shift of plants from growth light to high light results in an increase of PSII core phosphorylation, whereas LHCII phosphorylation concomitantly decreases. Exactly the opposite takes place when plants are shifted to lower light intensity. Despite distinct changes occurring in thylakoid protein phosphorylation upon light intensity changes, the excitation balance between PSII and photosystem I remains unchanged. This differs drastically from the canonical-state transition model induced by artificial states 1 and 2 lights that concomitantly either dephosphorylate or phosphorylate, respectively, both the PSII core and LHCII phosphoproteins. Analysis of the kinase and phosphatase mutants revealed that TAP38/PPH1 phosphatase is crucial in preventing state transition upon increase in light intensity. Indeed, tap38/pph1 mutant revealed strong concomitant phosphorylation of both the PSII core and LHCII proteins upon transfer to high light, thus resembling the wild type under state 2 light. Coordinated function of thylakoid protein kinases and phosphatases is shown to secure balanced excitation energy for both photosystems by preventing state transitions upon changes in light intensity. Moreover, PROTON GRADIENT REGULATION5 (PGR5) is required for proper regulation of thylakoid protein kinases and phosphatases, and the pgr5 mutant mimics phenotypes of tap38/pph1. This shows that there is a close cooperation between the redox- and proton gradient-dependent regulatory mechanisms for proper function of the photosynthetic machinery. PMID:25902812

  19. LED intense headband light source for fingerprint analysis

    DOEpatents

    Villa-Aleman, Eliel

    2005-03-08

    A portable, lightweight and high-intensity light source for detecting and analyzing fingerprints during field investigation. On-site field analysis requires long hours of mobile analysis. In one embodiment, the present invention comprises a plurality of light emitting diodes; a power source; and a personal attachment means; wherein the light emitting diodes are powered by the power source, and wherein the power source and the light emitting diodes are attached to the personal attachment means to produce a personal light source for on-site analysis of latent fingerprints. The present invention is available for other applications as well.

  20. Note: An absolute X-Y-Θ position sensor using a two-dimensional phase-encoded binary scale

    NASA Astrophysics Data System (ADS)

    Kim, Jong-Ahn; Kim, Jae Wan; Kang, Chu-Shik; Jin, Jonghan

    2018-04-01

    This Note presents a new absolute X-Y-Θ position sensor for measuring planar motion of a precision multi-axis stage system. By analyzing the rotated image of a two-dimensional phase-encoded binary scale (2D), the absolute 2D position values at two separated points were obtained and the absolute X-Y-Θ position could be calculated combining these values. The sensor head was constructed using a board-level camera, a light-emitting diode light source, an imaging lens, and a cube beam-splitter. To obtain the uniform intensity profiles from the vignette scale image, we selected the averaging directions deliberately, and higher resolution in the angle measurement could be achieved by increasing the allowable offset size. The performance of a prototype sensor was evaluated in respect of resolution, nonlinearity, and repeatability. The sensor could resolve 25 nm linear and 0.001° angular displacements clearly, and the standard deviations were less than 18 nm when 2D grid positions were measured repeatedly.

  1. Optoelectronic device for the measurement of the absolute linear position in the micrometric displacement range

    NASA Astrophysics Data System (ADS)

    Morlanes, Tomas; de la Pena, Jose L.; Sanchez-Brea, Luis M.; Alonso, Jose; Crespo, Daniel; Saez-Landete, Jose B.; Bernabeu, Eusebio

    2005-07-01

    In this work, an optoelectronic device that provides the absolute position of a measurement element with respect to a pattern scale upon switch-on is presented. That means that there is not a need to perform any kind of transversal displacement after the startup of the system. The optoelectronic device is based on the process of light propagation passing through a slit. A light source with a definite size guarantees the relation of distances between the different elements that constitute our system and allows getting a particular optical intensity profile that can be measured by an electronic post-processing device providing the absolute location of the system with a resolution of 1 micron. The accuracy of this measuring device is restricted to the same limitations of any incremental position optical encoder.

  2. Light shield and cooling apparatus. [high intensity ultraviolet lamp

    NASA Technical Reports Server (NTRS)

    Meador, T. G., Jr. (Inventor)

    1974-01-01

    A light shield and cooling apparatus was developed for a high intensity ultraviolet lamp including water and high pressure air for cooling and additional apparatus for shielding the light and suppressing the high pressure air noise.

  3. Stolephorus sp Behavior in Different LED (Light Emitting Diode) Color and Light Intensities

    NASA Astrophysics Data System (ADS)

    Fitri Aristi, D. P.; Ramadanita, I. A.; Hapsari, T. D.; Susanto, A.

    2018-02-01

    This research aims to observe anchovy (Stolephorus sp) behavior under different LED light intensities that affect eye physiology (cell cone structure). The materials used were Stolephorus sp taken from the waters off Jepara and 13 and 10 watt light emitting diode (LED). The research method was an experiment conducted from March through August 2015 in the waters off Jepara. Data analysis of visual histology and fish respond was carried out at the fishing gear material laboratory, anatomy and cultivate. Cone cell structure (mosaic cone) of Stolephorus sp forms a connected regular square pattern with every single cone surrounded by four double cones, which indicate that anchovies are sensitive to light. The 13 watt LED (628 lux) has faster response than the 10 watt LED (531 lux) as it has wider and higher emitting intensity, which also attracts fish to gather quicker.

  4. Absolute angular encoder based on optical diffraction

    NASA Astrophysics Data System (ADS)

    Wu, Jian; Zhou, Tingting; Yuan, Bo; Wang, Liqiang

    2015-08-01

    A new encoding method for absolute angular encoder based on optical diffraction was proposed in the present study. In this method, an encoder disc is specially designed that a series of elements are uniformly spaced in one circle and each element is consisted of four diffraction gratings, which are tilted in the directions of 30°, 60°, -60° and -30°, respectively. The disc is illuminated by a coherent light and the diffractive signals are received. The positions of diffractive spots are used for absolute encoding and their intensities are for subdivision, which is different from the traditional optical encoder based on transparent/opaque binary principle. Since the track's width in the disc is not limited in the diffraction pattern, it provides a new way to solve the contradiction between the size and resolution, which is good for minimization of encoder. According to the proposed principle, the diffraction pattern disc with a diameter of 40 mm was made by lithography in the glass substrate. A prototype of absolute angular encoder with a resolution of 20" was built up. Its maximum error was tested as 78" by comparing with a small angle measuring system based on laser beam deflection.

  5. Current Trends in Intense Pulsed Light

    PubMed Central

    2012-01-01

    Intense pulsed light technologies have evolved significantly since their introduction to the medical community 20 years ago. Now such devices can be used safely and effectively for the cosmetic treatment of many vascular lesions, unwanted hair, and pigmented lesions. Newer technologies often give results equal to those of laser treatments. PMID:22768357

  6. Behavioral and physiological photoresponses to light intensity by intertidal microphytobenthos

    NASA Astrophysics Data System (ADS)

    Du, Guoying; Yan, Hongmei; Liu, Chunrong; Mao, Yunxiang

    2018-03-01

    Behavioral and physiological responses to light are the two major mechanisms by which natural microphytobenthic assemblages adapt to the intertidal environment and protect themselves from light stress. The present study investigated these photoresponses with different light intensities over 8 h of illumination, and used a specific inhibitor (Latrunculin A, Lat A) for migration to compare migratory and non-migratory microphytobenthos (MPB). Photosynthetic activity was detected using rapid light curves and induction curves by chlorophyll fluorescence. It showed distinct variation in migratory responses to different light intensities; high light induced downward migration to avoid photoinhibition, and low and medium light (50-250 μmol/(m2·s)) promoted upward migration followed by downward migration after certain period of light exposure. No significant difference in non-photochemical quenching (NPQ) or PSII maximal quantum yield ( F v/ F m) was detected between low and medium light irradiance, possibly indicating that only high light influences the photosynthetic capability of MPB. Decreased photosynthetic activity, indicated by three parameters, the maximum relative electron transport rate (rETR max), minimum saturating irradiance ( E k) and light utilization coefficient ( α), was observed in MPB after exposure to prolonged illumination under low and medium light. Lat A effectively inhibited the migration of MPB in all light treatments and induced lower F v/ F m under high light (500 and 100 μmol/(m2·s)) and prolonged illumination at 250 μmol/(m2·s), but did not significantly influence F v/ F m under low light (0-100 μmol/(m2·s)) or NPQ. The increase of NPQ in Lat A treatments with time implied that the MPB assemblages can recover their physiological photoprotection capacity to adapt to light stress. Non-migratory MPB exhibited lower light use efficiency (lower α) and lower maximum photosynthetic capacity (lower rETR max) than migratory MPB under light

  7. Absolute Infrared Intensities and Interstellar Ice Abundances- From Neutrals to Ions

    NASA Astrophysics Data System (ADS)

    Gerakines, Perry

    Infrared (IR) telescopes, such as Spitzer and SOFIA, have revealed a rich variety of chemical species trapped in interstellar ices. However, quantifying the abundances of these species has been difficult because some molecules, such as formaldehyde (H2CO), and some ions, such as ammonium (NH4+), have poorly-known IR optical parameters, such as band strengths and optical constants. In the case of NH4+, the most widely used band-intensity values are from a mere two measurements published over a decade ago. Those two experiments cannot be repeated or checked as the original publication provided no information on reaction temperature, heating rate, spectral resolution, and so forth, and the two authors are no longer active in the field. Moreover, neither kinetic data nor statistics on the two measurements were provided, clearly an unsatisfactory situation. Exacerbating the problem is that NH4+ is sometimes used as a check on the IR spectral intensities of other ions, such as OCN- (cyanate), which has its own checkered past. We propose to correct these problems associated with abundance determinations of selected interstellar ices. We will combine two recent successful efforts from our laboratory and measure band intensities for NH4+ and OCN-, as well as HCOO- (formate). To unravel the interstellar formate band requires that we also properly determine its spectral baseline to distinguish from co-absorbing species, primarily formaldehyde (H2CO). Since the latter also has, at best, poorly-determined IR absolute intensities, we will measure them at multiple temperatures and ice phases for this project. This work will build on our recent success in deriving optical constants from IR spectra for interstellar hydrocarbon and nitrile ices (Hudson et al., 2014a, 2014b), and in generating NH4+ in situ for a study of Jupiter's atmosphere (Loeffler and Hudson, 2015). As a bonus, the proposed measurements also will enable the determination of band-strengths for such ions as CN-, NO

  8. Lead paint removal with high-intensity light pulses.

    PubMed

    Grapperhaus, Michael J; Schaefer, Raymond B

    2006-12-15

    This paper presents the results of an initial investigation into using high-intensity incoherent light pulses to strip paint. Measurements of light pulse characteristics, the reflectivity of different paints and initial experiments on the threshold for paint removal, and paint removal are presented, along with an approximate model consistent with experimental results. Paint removal tests include lead paint, the reduction of lead levels to below levels required for lead abatement, as well as air and light emissions measurements that are within regulatory guidelines.

  9. Performance of Different Light Sources for the Absolute Calibration of Radiation Thermometers

    NASA Astrophysics Data System (ADS)

    Martín, M. J.; Mantilla, J. M.; del Campo, D.; Hernanz, M. L.; Pons, A.; Campos, J.

    2017-09-01

    The evolving mise en pratique for the definition of the kelvin (MeP-K) [1, 2] will, in its forthcoming edition, encourage the realization and dissemination of the thermodynamic temperature either directly (primary thermometry) or indirectly (relative primary thermometry) via fixed points with assigned reference thermodynamic temperatures. In the last years, the Centro Español de Metrología (CEM), in collaboration with the Instituto de Óptica of Consejo Superior de Investigaciones Científicas (IO-CSIC), has developed several setups for absolute calibration of standard radiation thermometers using the radiance method to allow CEM the direct dissemination of the thermodynamic temperature and the assignment of the thermodynamic temperatures to several fixed points. Different calibration facilities based on a monochromator and/or a laser and an integrating sphere have been developed to calibrate CEM's standard radiation thermometers (KE-LP2 and KE-LP4) and filter radiometer (FIRA2). This system is based on the one described in [3] placed in IO-CSIC. Different light sources have been tried and tested for measuring absolute spectral radiance responsivity: a Xe-Hg 500 W lamp, a supercontinuum laser NKT SuperK-EXR20 and a diode laser emitting at 6473 nm with a typical maximum power of 120 mW. Their advantages and disadvantages have been studied such as sensitivity to interferences generated by the laser inside the filter, flux stability generated by the radiant sources and so forth. This paper describes the setups used, the uncertainty budgets and the results obtained for the absolute temperatures of Cu, Co-C, Pt-C and Re-C fixed points, measured with the three thermometers with central wavelengths around 650 nm.

  10. Experimental effective intensity of steady and flashing light emitting diodes for aircraft anti-collision lighting.

    DOT National Transportation Integrated Search

    2013-08-01

    Research was conducted to determine the effective intensity of flashing lights that incorporate light-emitting diodes (LEDs). LEDs require less power and have the ability to flash without the addition of moving parts. Compared with incandescent bulbs...

  11. Determination of the absolute carrier-envelope phase by angle-resolved photoelectron spectra of Ar by intense circularly polarized few-cycle pulses

    NASA Astrophysics Data System (ADS)

    Fukahori, Shinichi; Ando, Toshiaki; Miura, Shun; Kanya, Reika; Yamanouchi, Kaoru; Rathje, Tim; Paulus, Gerhard G.

    2017-05-01

    The angle-resolved photoelectron spectra of Ar are recorded using intense circularly polarized near-infrared few-cycle laser pulses, and the effect of the depletion of Ar atoms by the ionization and the effect of the Coulombic potential are examined by the classical trajectory Monte Carlo simulations. On the basis of the comparison between the experimental and theoretical photoelectron spectra, a procedure for estimating the absolute carrier-envelope phase (CEP) of the few-cycle laser pulses interacting with atoms and molecules is proposed. It is confirmed that the absolute CEP can securely be estimated without any numerical calculations once the angular distribution of the yield of photoelectrons having the kinetic energy larger than 30 eV is measured with the peak laser intensity in the range between 1 ×1014 and 5 ×1014W /c m2 .

  12. Excited-state structure and electronic dephasing time of Nile blue from absolute resonance Raman intensities

    NASA Astrophysics Data System (ADS)

    Lawless, Mary K.; Mathies, Richard A.

    1992-06-01

    Absolute resonance Raman cross sections are measured for Nile blue 690 perchlorate dissolved in ethylene glycol with excitation at 514, 531, and 568 nm. These values and the absorption spectrum are modeled using a time-dependent wave packet formalism. The excited-state equilibrium geometry changes are quantitated for 40 resonance Raman active modes, seven of which (590, 1141, 1351, 1429, 1492, 1544, and 1640 cm-1 ) carry 70% of the total resonance Raman intensity. This demonstrates that in addition to the prominent 590 and 1640 cm-1 modes, a large number of vibrational degrees of freedom are Franck-Condon coupled to the electronic transition. After exposure of the explicit vibrational progressions, the residual absorption linewidth is separated into its homogeneous [350 cm-1 half-width at half-maximum (HWHM)] and inhomogeneous (313 cm-1 HWHM) components through an analysis of the absolute Raman cross sections. The value of the electronic dephasing time derived from this study (25 fs) compares well to previously published results. These data should be valuable in multimode modeling of femtosecond experiments on Nile blue.

  13. Muscle Activation During Exercise in Severe Acute Hypoxia: Role of Absolute and Relative Intensity

    PubMed Central

    Torres-Peralta, Rafael; Losa-Reyna, José; González-Izal, Miriam; Perez-Suarez, Ismael; Calle-Herrero, Jaime; Izquierdo, Mikel

    2014-01-01

    Abstract Torres-Peralta, Rafael, José Losa-Reyna, Miriam González-Izal, Ismael Perez-Suarez, Jaime Calle-Herrero, Mikel Izquierdo, and José A.L. Calbet. Muscle activation during exercise in severe acute hypoxia: Role of absolute and relative intensity. High Alt Med Biol 15:472–482, 2014.—The aim of this study was to determine the influence of severe acute hypoxia on muscle activation during whole body dynamic exercise. Eleven young men performed four incremental cycle ergometer tests to exhaustion breathing normoxic (FIo2=0.21, two tests) or hypoxic gas (FIo2=0.108, two tests). Surface electromyography (EMG) activities of rectus femoris (RF), vastus medialis (VL), vastus lateralis (VL), and biceps femoris (BF) were recorded. The two normoxic and the two hypoxic tests were averaged to reduce EMG variability. Peak Vo2 was 34% lower in hypoxia than in normoxia (p<0.05). The EMG root mean square (RMS) increased with exercise intensity in all muscles (p<0.05), with greater effect in hypoxia than in normoxia in the RF and VM (p<0.05), and a similar trend in VL (p=0.10). At the same relative intensity, the RMS was greater in normoxia than in hypoxia in RF, VL, and BF (p<0.05), with a similar trend in VM (p=0.08). Median frequency increased with exercise intensity (p<0.05), and was higher in hypoxia than in normoxia in VL (p<0.05). Muscle contraction burst duration increased with exercise intensity in VM and VL (p<0.05), without clear effects of FIo2. No significant FIo2 effects on frequency domain indices were observed when compared at the same relative intensity. In conclusion, muscle activation during whole body exercise increases almost linearly with exercise intensity, following a muscle-specific pattern, which is adjusted depending on the FIo2 and the relative intensity of exercise. Both VL and VM are increasingly involved in power output generation with the increase of intensity and the reduction in FIo2. PMID:25225839

  14. Light-intensity and high-intensity interval training improve cardiometabolic health in rats.

    PubMed

    Batacan, Romeo B; Duncan, Mitch J; Dalbo, Vincent J; Connolly, Kylie J; Fenning, Andrew S

    2016-09-01

    Physical activity has the potential to reduce cardiometabolic risk factors but evaluation of different intensities of physical activity and the mechanisms behind their health effects still need to be fully established. This study examined the effects of sedentary behaviour, light-intensity training, and high-intensity interval training on biometric indices, glucose and lipid metabolism, inflammatory and oxidative stress markers, and vascular and cardiac function in adult rats. Rats (12 weeks old) were randomly assigned to 1 of 4 groups: control (CTL; no exercise), sedentary (SED; no exercise and housed in small cages to reduce activity), light-intensity trained (LIT; four 30-min exercise bouts/day at 8 m/min separated by 2-h rest period, 5 days/week), and high-intensity interval trained (HIIT, four 2.5-min work bouts/day at 50 m/min separated by 3-min rest periods, 5 days/week). After 12 weeks of intervention, SED had greater visceral fat accumulation (p < 0.01) and slower cardiac conduction (p = 0.04) compared with the CTL group. LIT and HIIT demonstrated beneficial changes in body weight, visceral and epididymal fat weight, glucose regulation, low-density lipoprotein cholesterol, total cholesterol, and mesenteric vessel contractile response compared with the CTL group (p < 0.05). LIT had significant improvements in insulin sensitivity and cardiac conduction compared with the CTL and SED groups whilst HIIT had significant improvements in systolic blood pressure and endothelium-independent vasodilation to aorta and mesenteric artery compared with the CTL group (p < 0.05). LIT and HIIT induce health benefits by improving traditional cardiometabolic risk factors. LIT improves cardiac health while HIIT promotes improvements in vascular health.

  15. Light trapping in thin-film solar cells measured by Raman spectroscopy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ledinský, M., E-mail: ledinsky@fzu.cz; Photovoltaics and Thin Film Electronics Laboratory, Institute of Microengineering; Moulin, E.

    2014-09-15

    In this study, Raman spectroscopy is used as a tool to determine the light-trapping capability of textured ZnO front electrodes implemented in microcrystalline silicon (μc-Si:H) solar cells. Microcrystalline silicon films deposited on superstrates of various roughnesses are characterized by Raman micro-spectroscopy at excitation wavelengths of 442 nm, 514 nm, 633 nm, and 785 nm, respectively. The way to measure quantitatively and with a high level of reproducibility the Raman intensity is described in details. By varying the superstrate texture and with it the light trapping in the μc-Si:H absorber layer, we find significant differences in the absolute Raman intensity measured in the near infraredmore » wavelength region (where light trapping is relevant). A good agreement between the absolute Raman intensity and the external quantum efficiency of the μc-Si:H solar cells is obtained, demonstrating the validity of the introduced method. Applications to thin-film solar cells, in general, and other optoelectronic devices are discussed.« less

  16. Comparison of absolute intensity between EAS with gamma-families and general EAS at Mount Norikura

    NASA Technical Reports Server (NTRS)

    Mitsumune, T.; Nakatsuka, T.; Nishikawa, K.; Saito, T.; Sakata, M.; Shima, M.; Yamamoto, Y.; Dake, S.; Kawamoto, M.; Kusumose, M.

    1985-01-01

    Gamma-families with total energy greater than 10 TeV, found in the EX chamber which was cooperated with the EAS array were combined with EAS triggered by big bursts. The absolute intensity of the size spectrum of these combined EAS was compared with that of general EAS obtained by AS trigger. The EAS with sizes greater than 2x1 million were always accompanied by gamma-families with sigma E sub gamma H 10 TeV, n sub gamma, H 2 and Emin=3 TeV, although the rate of EAS accompaning such gamma-families decreases rapidly as their sizes decrease.

  17. Lower light intensity reduces larval aggression in matrinxã, Brycon amazonicus.

    PubMed

    Lopes, Ana Caroliny C; Villacorta-Correa, Marle Angélica; Carvalho, Thaís B

    2018-06-01

    Brycon amazonicus shows a high frequency of aggressive behavior, which can be a limiting factor in intensive farming systems. Environmental changes can modulate the social interactions of fish and reduce aggression during the different stages of production. Groups of three larvae at 12 h after hatching (HAH) were subjected to different levels of light intensity: low (17 ± 3 lx), intermediate (204 ± 12.17 lx) and high (1,613.33 ± 499.03 lx), with eight replicates for each level. The lower light intensity reduced the frequency of aggressive interactions and locomotor activity exhibited by the animals. Based on these results, light intensity modulates aggression in B. amazonicus larvae. Manipulation of this factor could improve the social conditions of this species during farming and contribute to the development of new production technologies. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Effects of light intensity on components and topographical structures of extracellular polysaccharides from the cyanobacteria Nostoc sp.

    PubMed

    Ge, Hongmei; Xia, Ling; Zhou, Xuping; Zhang, Delu; Hu, Chunxiang

    2014-02-01

    A study on the effects of light intensity (40 and 80 μE/m(2)/sec) on the components and topographical structures of extracellular polysaccharides (EPS) was carried out in cyanobacteria Nostoc sp.. EPS yield increased with light intensity. However, light intensity did not significantly affect the EPS fractions and monosaccharide composition. Higher light intensity generally resulted in higher protein content of EPS in similar fractions. The topographical structure of EPS, investigated by atomic force microscopy, appeared as spherical lumps, chains and networks. The long chains were observed at higher light intensity. Thus, light intensity affected the yield and nature of EPS.

  19. 14 CFR 23.1389 - Position light distribution and intensities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... prescribed in this section must be provided by new equipment with each light cover and color filter in place... clarity. When the peak intensity of the left and right position lights is more than 100 candles, the... the right and left of the axis of maximum illumination. [Doc. No. 4080, 29 FR 17955, Dec. 18, 1964, as...

  20. Light-intensity physical activity is associated with insulin resistance in elderly Japanese women independent of moderate-to vigorous-intensity physical activity.

    PubMed

    Gando, Yuko; Murakami, Haruka; Kawakami, Ryoko; Tanaka, Noriko; Sanada, Kiyoshi; Tabata, Izumi; Higuchi, Mitsuru; Miyachi, Motohiko

    2014-02-01

    It is unclear whether light physical activity is beneficially associated with insulin resistance, similar to moderate and/or vigorous physical activity. This cross-sectional study was performed to determine the relationship between the amount of light physical activity, as determined with a triaxial accelerometer, and insulin resistance. A total of 807 healthy men and women participated in this study. Physical activity was measured using a triaxial accelerometer worn for 28 days and summarized as light intensity (1.1-2.9 METs) or moderate to vigorous intensity (≥ 3.0 METs). Insulin resistance was evaluated by HOMA_R (FPG [mg/dL] × IRI [μU/mL]/405). The daily time spent in light physical activity was inversely associated with HOMA_R (r = -0.173, P < 0.05). After adjustment for confounders, the association between light physical activity and HOMA_R remained statistically significant (β = -0.119, P < .05). Light physical activity remained significantly associated with HOMA_R following further adjustment for moderate to vigorous intensity activity (β = -0.125, P < .05). Similar results were observed when light physical activity was modeled as quartiles, especially in elderly women. These cross-sectional data suggest that light-intensity physical activity is beneficially associated with insulin resistance in elderly Japanese women.

  1. Lighting design in the neonatal intensive care unit: practical applications of scientific principles.

    PubMed

    White, Robert D

    2004-06-01

    Meeting the varied lighting needs of infants, caregivers, and families has become more complex as our understanding of visual development and perception and the effect of light on circadian rhythms advances. Optimal lighting strategies are discussed for new unit construction, as well as modifications to consider for existing units. In either case, the key concept is that lighting should be provided for the individual needs of each person, rather than the full-room lighting schemes previously used. Ideas gleaned from nonhospital settings, re-introduction of natural light into the neonatal intensive care unit, and new devices such as light-emitting diodes will dramatically change the lighting and visual environment of future neonatal intensive care units.

  2. Cockpit noise intensity : eleven twin-engine light aircraft.

    DOT National Transportation Integrated Search

    1968-10-01

    Eleven of the most popular twin-engine general-aviation light aircraft were tested for the noise intensity present during normal cruising operations at 2000, 6000, and 10000 feet MSL (mean sea level). Although generally quieter than single-engine pla...

  3. Design of Automatic Intensity Varying Smart Street Lighting System

    NASA Astrophysics Data System (ADS)

    Gupta, Ashutosh; Gupta, Shipra

    2017-08-01

    The paper is proposed with an aim of power conservation. In this era of development, it is essential to develop a streetlight that turns on and off automatically without human interference. To achieve this light sensor have been placed in each panel which turns the street light on and off automatically. For energy conservation cool-white LED’s have been used in street light panel and dimmer modules have been installed which changes the intensity of the streetlight depending on the darkness.

  4. Design considerations and validation of the MSTAR absolute metrology system

    NASA Astrophysics Data System (ADS)

    Peters, Robert D.; Lay, Oliver P.; Dubovitsky, Serge; Burger, Johan; Jeganathan, Muthu

    2004-08-01

    Absolute metrology measures the actual distance between two optical fiducials. A number of methods have been employed, including pulsed time-of-flight, intensity-modulated optical beam, and two-color interferometry. The rms accuracy is currently limited to ~5 microns. Resolving the integer number of wavelengths requires a 1-sigma range accuracy of ~0.1 microns. Closing this gap has a large pay-off: the range (length measurement) accuracy can be increased substantially using the unambiguous optical phase. The MSTAR sensor (Modulation Sideband Technology for Absolute Ranging) is a new system for measuring absolute distance, capable of resolving the integer cycle ambiguity of standard interferometers, and making it possible to measure distance with sub-nanometer accuracy. In this paper, we present recent experiments that use dispersed white light interferometry to independently validate the zero-point of the system. We also describe progress towards reducing the size of optics, and stabilizing the laser wavelength for operation over larger target ranges. MSTAR is a general-purpose tool for conveniently measuring length with much greater accuracy than was previously possible, and has a wide range of possible applications.

  5. The effect of infection-control barriers on the light intensity of light-cure units and depth of cure of composite.

    PubMed

    Hodson, Nicholas A; Dunne, Stephen M; Pankhurst, Caroline L

    2005-04-01

    Dental curing lights are vulnerable to contamination with oral fluids during routine intra-oral use. This controlled study aimed to evaluate whether or not disposable transparent barriers placed over the light-guide tip would affect light output intensity or the subsequent depth of cure of a composite restoration. The impact on light intensity emitted from high-, medium- and low-output light-cure units in the presence of two commercially available disposable infection-control barriers was evaluated against a no-barrier control. Power density measurements from the three intensity light-cure units were recorded with a radiometer, then converted to a digital image using an intra-oral camera and values determined using a commercial computer program. For each curing unit, the measurements were repeated on ten separate occasions with each barrier and the control. Depth of cure was evaluated using a scrape test in a natural tooth model. At each level of light output, the two disposable barriers produced a significant reduction in the mean power density readings compared to the no-barrier control (P<0.005). The cure sleeve inhibited light output to a greater extent than either the cling film or the control (P<0.005). Only composite restorations light-activated by the high level unit demonstrated a small but significant decrease in the depth of cure compared to the control (P<0.05). Placing disposable barriers over the light-guide tip reduced the light intensity from all three curing lights. There was no impact on depth of cure except for the high-output light, where a small decrease in cure depth was noted but this was not considered clinically significant. Disposable barriers can be recommended for use with light-cure lights.

  6. Cockpit noise intensity : fifteen single-engine light aircraft.

    DOT National Transportation Integrated Search

    1968-09-01

    Fifteen of the most popular single-engine general-aviation light aircraft were tested for the noise intensity present during normal cruising operations at 2000, and 10,000 feet MSL (mean sea level). In comparison with currently accepted DRC (damage-r...

  7. Extraordinary variation of pump light intensity inside a four-level solid-state laser medium

    NASA Astrophysics Data System (ADS)

    Qin, Hua; Fu, Rulian; Wang, Zhaoqi; Liu, Juan

    2008-08-01

    A theoretical investigation of the absorption of the pump light at different intensities through a four-level solid-state laser medium is presented. It is found that the variation of the pump intensity inside the laser medium cannot always simply be dominated by Beer's law. Transmission of the pump light through this laser medium is closely related to the pump intensity itself. In fact, when the pump intensity is relatively low, whose values depend on the characteristics of the medium, the variation of the pump light through the laser medium is consistent with Beer's law. However, while the pump intensity is high enough, the relationship between the transmission of the pump light and its propagation distance is demonstrated to be linear. These theoretical results have been confirmed by the experiment with a medium of YAG:Nd.

  8. Absolute Bunch Length Measurements at the ALS by Incoherent Synchrotron Radiation Fluctuation Analysis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Filippetto, D.; /Frascati; Sannibale, F.

    2008-01-24

    By analyzing the pulse to pulse intensity fluctuations of the radiation emitted by a charge particle in the incoherent part of the spectrum, it is possible to extract information about the spatial distribution of the beam. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory, we have developed and tested a simple scheme based on this principle that allows for the absolute measurement of the bunch length. A description of the method and the experimental results are presented.

  9. The absolute threshold of cone vision

    PubMed Central

    Koeing, Darran; Hofer, Heidi

    2013-01-01

    We report measurements of the absolute threshold of cone vision, which has been previously underestimated due to sub-optimal conditions or overly strict subjective response criteria. We avoided these limitations by using optimized stimuli and experimental conditions while having subjects respond within a rating scale framework. Small (1′ fwhm), brief (34 msec), monochromatic (550 nm) stimuli were foveally presented at multiple intensities in dark-adapted retina for 5 subjects. For comparison, 4 subjects underwent similar testing with rod-optimized stimuli. Cone absolute threshold, that is, the minimum light energy for which subjects were just able to detect a visual stimulus with any response criterion, was 203 ± 38 photons at the cornea, ∼0.47 log units lower than previously reported. Two-alternative forced-choice measurements in a subset of subjects yielded consistent results. Cone thresholds were less responsive to criterion changes than rod thresholds, suggesting a limit to the stimulus information recoverable from the cone mosaic in addition to the limit imposed by Poisson noise. Results were consistent with expectations for detection in the face of stimulus uncertainty. We discuss implications of these findings for modeling the first stages of human cone vision and interpreting psychophysical data acquired with adaptive optics at the spatial scale of the receptor mosaic. PMID:21270115

  10. Light intensity affects the uptake and metabolism of glycine by pakchoi (Brassica chinensis L.)

    NASA Astrophysics Data System (ADS)

    Ma, Qingxu; Cao, Xiaochuang; Wu, Lianghuan; Mi, Wenhai; Feng, Ying

    2016-02-01

    The uptake of glycine by pakchoi (Brassica chinensis L.), when supplied as single N-source or in a mixture of glycine and inorganic N, was studied at different light intensities under sterile conditions. At the optimal intensity (414 μmol m-2 s-1) for plant growth, glycine, nitrate, and ammonium contributed 29.4%, 39.5%, and 31.1% shoot N, respectively, and light intensity altered the preferential absorption of N sources. The lower 15N-nitrate in root but higher in shoot and the higher 15N-glycine in root but lower in shoot suggested that most 15N-nitrate uptake by root transported to shoot rapidly, with the shoot being important for nitrate assimilation, and the N contribution of glycine was limited by post-uptake metabolism. The amount of glycine that was taken up by the plant was likely limited by root uptake at low light intensities and by the metabolism of ammonium produced by glycine at high light intensities. These results indicate that pakchoi has the ability to uptake a large quantity of glycine, but that uptake is strongly regulated by light intensity, with metabolism in the root inhibiting its N contribution.

  11. Adjustable long duration high-intensity point light source

    NASA Astrophysics Data System (ADS)

    Krehl, P.; Hagelweide, J. B.

    1981-06-01

    A new long duration high-intensity point light source with adjustable light duration and a small light spot locally stable in time has been developed. The principle involved is a stationary high-temperature plasma flow inside a partly constrained capillary of a coaxial spark gap which is viewed end on through a terminating Plexiglas window. The point light spark gap is operated via a resistor by an artificial transmission line. Using two exchangeable inductance sets in the line, two ranges of photoduration 10-130 μs and 100-600 μs can be covered. For a light spot size of 1.5 mm diameter the corresponding peak light output amounts to 5×106 and 1.6×106 candelas, respectively. Within these ranges the duration is controlled by an ignitron crowbar to extinguish the plasma. The adjustable photoduration is very useful for the application of continuous writing rotating mirror cameras, thus preventing multiple exposures. The essentially uniform exposure within the visible spectral range makes the new light source suitable for color cinematography.

  12. 14 CFR 23.1393 - Minimum intensities in any vertical plane of position lights.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Minimum intensities in any vertical plane... CATEGORY AIRPLANES Equipment Lights § 23.1393 Minimum intensities in any vertical plane of position lights... above or below the horizontal plane Intensity, l 0° 1.00 0° to 5° 0.90 5° to 10° 0.80 10° to 15° 0.70 15...

  13. 14 CFR 23.1391 - Minimum intensities in the horizontal plane of position lights.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Minimum intensities in the horizontal plane of position lights. 23.1391 Section 23.1391 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... CATEGORY AIRPLANES Equipment Lights § 23.1391 Minimum intensities in the horizontal plane of position...

  14. Light colour and intensity alters reproductive/seasonal responses in Japanese quail.

    PubMed

    Yadav, Suneeta; Chaturvedi, Chandra Mohini

    2015-08-01

    An extensive literature is available on the photoperiodic responses of avian species but studies on light colour and wavelength from light emitting diode (LED) sources on reproduction are limited. Hence, an experiment was designed to study the effect of different colours and intensities of light on the reproductive responses of Japanese quail. Three-week old quail were exposed to five different light conditions with a long photoperiod (LD 16:8): WT (white fluorescent light 100 lux as control), W LED (white light emitting diode, 30 lux), B LED (blue LED, 30 lux), G LED (green LED, 30 lux) and R-LED (red LED, 30 lux). The cloacal gland size, an indicator of androgenic activity, was monitored weekly. The results indicated an early initiation of gonadal growth in WT quail which continued and maintained a plateau throughout the period of study. On the other hand, in general low intensity light, there was a decreased amplitude of the reproductive cycle and the quail exposed to different colour lights (green, red and blue lights) used different incubation times to initiate their gonadal growth and exhibited a gonadal cycle of a different duration up to 15.5 weeks. Thereafter, the gonad of quail of all the LED groups started developing again (including the blue LED exposed quail which remained undeveloped until this age) and attained the increased degree of growth until 26.5 weeks of age. During the second cycle, gonads of green and red light exposed quail continued to increase and maintained a plateau of development similar to WT exposed control while white and blue LED exposed quail exhibited spontaneous regression and attained complete sexual quiescence. Based on our study, it is suggested that long term exposure to blue LED light of low intensity may induce gonadal regression even under long-day conditions (LD 16:8), while exposure to green and red lights appears to maintain a constant photosensitivity after one complete gonadal cycle. Copyright © 2015 Elsevier Inc

  15. The role of lasers and intense pulsed light technology in dermatology

    PubMed Central

    Husain, Zain; Alster, Tina S

    2016-01-01

    The role of light-based technologies in dermatology has expanded dramatically in recent years. Lasers and intense pulsed light have been used to safely and effectively treat a diverse array of cutaneous conditions, including vascular and pigmented lesions, tattoos, scars, and undesired hair, while also providing extensive therapeutic options for cosmetic rejuvenation and other dermatologic conditions. Dermatologic laser procedures are becoming increasingly popular worldwide, and demand for them has fueled new innovations and clinical applications. These systems continue to evolve and provide enhanced therapeutic outcomes with improved safety profiles. This review highlights the important roles and varied clinical applications that lasers and intense pulsed light play in the dermatologic practice. PMID:26893574

  16. Light Intensity is Important for Hydrogen Production in NaHSO3-Treated Chlamydomonas reinhardtii.

    PubMed

    Wei, Lanzhen; Yi, Jing; Wang, Lianjun; Huang, Tingting; Gao, Fudan; Wang, Quanxi; Ma, Weimin

    2017-03-01

    Chlamydomonas reinhardtii is a unicellular green alga that can use light energy to produce H2 from H2O in the background of NaHSO3 treatment. However, the role of light intensity in such H2 production remains elusive. Here, light intensity significantly affected the yield of H2 production in NaHSO3-treated C. reinhardtii, which was consistent with its effects on the content of O2 and the expression and activity of hydrogenase. Further, NaHSO3 was found to be able to remove O2 via a reaction of bisulfite with superoxide anion produced at the acceptor side of PSI, and light intensity affected the reaction rate significantly. Accordingly, high light and strong light but not low light can create an anaerobic environment, which is important to activate hydrogenase and produce H2. Based on the above results, we conclude that light intensity plays an important role in removing O2 and consequently activating hydrogenase and producing H2 in NaHSO3-treated C. reinhardtii. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  17. Differences in the intensity of light-induced fluorescence emitted by resin composites.

    PubMed

    Kim, Bo-Ra; Kang, Si-Mook; Kim, Gyung-Min; Kim, Baek-Il

    2016-03-01

    The aims of this study were to compare the intensities of fluorescence emitted by different resin composites as detected using quantitative light-induced fluorescence (QLF) technology, and to compare the fluorescence intensity contrast with the color contrast between a restored composite and the adjacent region of the tooth. Six brands of light-cured resin composites (shade A2) were investigated. The composites were used to prepare composite discs, and fill holes that had been prepared in extracted human teeth. White-light and fluorescence images of all specimens were obtained using a fluorescence camera based on QLF technology (QLF-D) and converted into 8-bit grayscale images. The fluorescence intensity of the discs as well as the fluorescence intensity contrast and the color contrast between the composite restoration and adjacent tooth region were calculated as grayscale levels. The grayscale levels for the composite discs differed significantly with the brand (p<0.001): DenFil (10.84±0.35, mean±SD), Filtek Z350 (58.28±1.37), Premisa (156.94±1.58), Grandio (177.20±0.81), Charisma (207.05±0.77), and Gradia direct posterior (211.52±1.66). The difference in grayscale levels between a resin restoration and the adjacent tooth was significantly greater in fluorescence images for each brand than in white-light images, except for the Filtek Z350 (p<0.05). However, the Filtek Z350 restoration was distinguishable from the adjacent tooth in a fluorescence image. The intensities of fluorescence detected from the resin composites varied. The differences between the composite and adjacent tooth were greater for the fluorescence intensity contrast than for the colors observed in the white-light images. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Northern Red Oak Seedling Growth Varies by Light Intensity and Seed Source

    Treesearch

    Charles E. McGee

    1968-01-01

    Northern red oak seedlings from each of three seed sources were subjected for one growing season to one of four intensities of light: full light, 70 percent light, 37 percent light, and 8 percent light. Seedlings grown in the open were taller than those grown in the shade and had more, generally heavier leaves. Height and leaf growth decreased as the amount of light...

  19. Effect of Dynamic Light Application on Cognitive Performance and Well-being of Intensive Care Nurses.

    PubMed

    Simons, Koen S; Boeijen, Enzio R K; Mertens, Marlies C; Rood, Paul; de Jager, Cornelis P C; van den Boogaard, Mark

    2018-05-01

    Exposure to bright light has alerting effects. In nurses, alertness may be decreased because of shift work and high work pressure, potentially reducing work performance and increasing the risk for medical errors. To determine whether high-intensity dynamic light improves cognitive performance, self-reported depressive signs and symptoms, fatigue, alertness, and well-being in intensive care unit nurses. In a single-center crossover study in an intensive care unit of a teaching hospital in the Netherlands, 10 registered nurses were randomly divided into 2 groups. Each group worked alternately for 3 to 4 days in patients' rooms with dynamic light and 3 to 4 days in control lighting settings. High-intensity dynamic light was administered through ceiling-mounted fluorescent tubes that delivered bluish white light up to 1700 lux during the daytime, versus 300 lux in control settings. Cognitive performance, self-reported depressive signs and symptoms, fatigue, and well-being before and after each period were assessed by using validated cognitive tests and questionnaires. Cognitive performance, self-reported depressive signs and symptoms, and fatigue did not differ significantly between the 2 light settings. Scores of subjective well-being were significantly lower after a period of working in dynamic light. Daytime lighting conditions did not affect intensive care unit nurses' cognitive performance, perceived depressive signs and symptoms, or fatigue. Perceived quality of life, predominantly in the psychological and environmental domains, was lower for nurses working in dynamic light. © 2018 American Association of Critical-Care Nurses.

  20. Technique for compressing light intensity ranges utilizing a specifically designed liquid crystal notch filter

    DOEpatents

    Rushford, Michael C.

    1988-01-01

    A pin hole camera assembly for use in viewing an object having a relatively large light intensity range, for example a crucible containing molten metal in an atomic vapor laser isotope separation (AVLIS) system is disclosed herein. The assembly includes means for optically compressing the light intensity range appearing at its input sufficient to make it receivable and decipherable by a standard video camera. To accomplish this, the assembly utilizes the combination of interference filter and a liquid crystal notch filter. The latter which preferably includes a cholesteric liquid crystal arrangement is configured to pass light at all wavelengths, except a relatively narrow wavelength band which defines the filter's notch, and includes means for causing the notch to vary to at least a limited extent with the intensity of light at its light incidence surface.

  1. Light intensity alters the extent of arsenic toxicity in Helianthus annuus L. seedlings.

    PubMed

    Yadav, Geeta; Srivastava, Prabhat Kumar; Singh, Vijay Pratap; Prasad, Sheo Mohan

    2014-06-01

    The present study is aimed at assessing the extent of arsenic (As) toxicity under three different light intensities-optimum (400 μmole photon m(-2) s(-1)), sub-optimum (225 μmole photon m(-2) s(-1)), and low (75 μmole photon m(-2) s(-1))-exposed to Helianthus annuus L. var. DRSF-113 seedlings by examining various physiological and biochemical parameters. Irrespective of the light intensities under which H. annuus L. seedlings were grown, there was an As dose (low, i.e., 6 mg kg(-1) soil, As1; and high, i.e., 12 mg kg(-1) soil, As2)-dependent decrease in all the growth parameters, viz., fresh mass, shoot length, and root length. Optimum light-grown seedlings exhibited better growth performance than the sub-optimum and low light-grown seedlings; however, low light-grown plants had maximum root and shoot lengths. Accumulation of As in the plant tissues depended upon its concentration used, proximity of the plant tissue, and intensity of the light. Greater intensity of light allowed greater assimilation of photosynthates accompanied by more uptake of nutrients along with As from the medium. The levels of chlorophyll a, b, and carotenoids declined with increasing concentrations of As. Seedlings acquired maximum Chl a and b under optimum light which were more compatible to face As1 and As2 doses of As, also evident from the overall status of enzymatic (SOD, POD, CAT, and GST) and non-enzymatic antioxidant (Pro).

  2. Clinical effect of reducing curing times with high-intensity LED lights

    PubMed Central

    Ward, Justin D.; Wolf, Bethany J.; Leite, Luis P.; Zhou, Jing

    2016-01-01

    Objective To evaluate the clinical performance of brackets cured with a high-intensity, light-emitting diode (LED) with a shorter curing time. Materials and Methods Thirty-four patients and a total of 680 brackets were examined using a randomized split-mouth design. The maxillary right and mandibular left quadrants were cured for 6 seconds with a high-intensity LED light (3200 mW/cm2) and the maxillary left and mandibular right quadrants were cured for 20 seconds with a standard-intensity LED light (1200 mW/cm2). Alternating patients had the quadrants inverted for the curing protocol. The number and date of each first-time bracket failure was recorded from 199 to 585 days posttreatment. Results The bracket failure rate was 1.18% for both curing methods. The proportion of bracket failure was not significantly different between curing methods (P = 1.000), genders (P = 1.000), jaws (P = .725), sides (P = .725), or quadrants (P = .547). Posterior teeth exhibited a greater proportion of failures (2.21%) relative to anterior teeth (0.49%), although the difference was not statistically significant (P = .065). Conclusions No difference was found in bond failure rates between the two curing methods. Both methods showed bond failure rates low enough to be considered clinically sufficient. The high-intensity LED light used with a shorter curing time may be considered an advantage due to the reduced chair time. PMID:25760887

  3. Beta decay of the fission product 125Sb and a new complete evaluation of absolute gamma ray transition intensities

    NASA Astrophysics Data System (ADS)

    Rajput, M. U.; Ali, N.; Hussain, S.; Mujahid, S. A.; MacMahon, D.

    2012-04-01

    The radionuclide 125Sb is a long-lived fission product, which decays to 125Te by negative beta emission with a half-life of 1008 day. The beta decay is followed by the emission of several gamma radiations, ranging from low to medium energy, that can suitably be used for high-resolution detector calibrations, decay heat calculations and in many other applications. In this work, the beta decay of 125Sb has been studied in detail. The complete published experimental data of relative gamma ray intensities in the beta decay of the radionuclide 125Sb has been compiled. The consistency analysis was performed and discrepancies found at several gamma ray energies. Evaluation of the discrepant data was carried out using Normalized Residual and RAJEVAL methods. The decay scheme balance was carried out using beta branching ratios, internal conversion coefficients, populating and depopulating gamma transitions to 125Te levels. The work has resulted in the consistent conversion factor equal to 29.59(13) %, and determined a new evaluated set of the absolute gamma ray emission probabilities. The work has also shown 22.99% of the delayed intensity fraction as outgoing from the 58 d isomeric 144 keV energy level and 77.01% of the prompt intensity fraction reaching to the ground state from the other excited states. The results are discussed and compared with previous evaluations. The present work includes additional experimental data sets which were not included in the previous evaluations. A new set of recommended relative and absolute gamma ray emission probabilities is presented.

  4. Absolute optical extinction measurements of single nano-objects by spatial modulation spectroscopy using a white lamp

    NASA Astrophysics Data System (ADS)

    Billaud, Pierre; Marhaba, Salem; Grillet, Nadia; Cottancin, Emmanuel; Bonnet, Christophe; Lermé, Jean; Vialle, Jean-Louis; Broyer, Michel; Pellarin, Michel

    2010-04-01

    This article describes a high sensitivity spectrophotometer designed to detect the overall extinction of light by a single nanoparticle (NP) in the 10-4-10-5 relative range, using a transmission measurement configuration. We focus here on the simple and low cost scheme where a white lamp is used as a light source, permitting easy and broadband extinction measurements (300-900 nm). Using a microscope, in a confocal geometry, an increased sensitivity is reached thanks to a modulation of the NP position under the light spot combined with lock-in detection. Moreover, it is shown that this technique gives access to the absolute extinction cross-sections of the single NP provided that the incident electromagnetic field distribution experienced by the NP is accurately characterized. In this respect, an experimental procedure to characterize the light spot profile in the focal plane, using a reference NP as a probe, is also laid out. The validity of this approach is discussed and confirmed by comparing experimental intensity distributions to theoretical calculations taking into account the vector character of the tightly focused beam. The calibration procedure permitting to obtain the absolute extinction cross-section of the probed NP is then fully described. Finally, the force of the present technique is illustrated through selected examples concerning spherical and slightly elongated gold and silver NPs. Absolute extinction measurements are found to be in good consistency with the NP size and shape independently obtained from transmission electron microscopy, showing that spatial modulation spectroscopy is a powerful tool to get an optical fingerprint of the NP.

  5. 14 CFR 27.1395 - Maximum intensities in overlapping beams of forward and rear position lights.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Maximum intensities in overlapping beams of forward and rear position lights. 27.1395 Section 27.1395 Aeronautics and Space FEDERAL AVIATION... Equipment Lights § 27.1395 Maximum intensities in overlapping beams of forward and rear position lights. No...

  6. 14 CFR 25.1395 - Maximum intensities in overlapping beams of forward and rear position lights.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Maximum intensities in overlapping beams of forward and rear position lights. 25.1395 Section 25.1395 Aeronautics and Space FEDERAL AVIATION... Equipment Lights § 25.1395 Maximum intensities in overlapping beams of forward and rear position lights. No...

  7. 14 CFR 29.1395 - Maximum intensities in overlapping beams of forward and rear position lights.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Maximum intensities in overlapping beams of forward and rear position lights. 29.1395 Section 29.1395 Aeronautics and Space FEDERAL AVIATION... Equipment Lights § 29.1395 Maximum intensities in overlapping beams of forward and rear position lights. No...

  8. Effects of digital phase-conjugate light intensity on time-reversal imaging through animal tissue.

    PubMed

    Toda, Sogo; Kato, Yuji; Kudo, Nobuki; Shimizu, Koichi

    2018-04-01

    For transillumination imaging of animal tissues, we have attempted to suppress the scattering effect in a turbid medium using the time-reversal principle of phase-conjugate light. We constructed a digital phase-conjugate system to enable intensity modulation and phase modulation. Using this system, we clarified the effectiveness of the intensity information for restoration of the original light distribution through a turbid medium. By varying the scattering coefficient of the medium, we clarified the limit of time-reversal ability with intensity information of the phase-conjugate light. Experiment results demonstrated the applicability of the proposed technique to animal tissue.

  9. High Intensity Organic Light-emitting Diodes

    NASA Astrophysics Data System (ADS)

    Qi, Xiangfei

    This thesis is dedicated to the fabrication, modeling, and characterization to achieve high efficiency organic light-emitting diodes (OLEDs) for illumination applications. Compared to conventional lighting sources, OLEDs enabled the direct conversion of electrical energy into light emission and have intrigued the world's lighting designers with the long-lasting, highly efficient illumination. We begin with a brief overview of organic technology, from basic organic semiconductor physics, to its application in optoelectronics, i.e. light-emitting diodes, photovoltaics, photodetectors and thin-film transistors. Due to the importance of phosphorescent materials, we will focus on the photophysics of metal complexes that is central to high efficiency OLED technology, followed by a transient study to examine the radiative decay dynamics in a series of phosphorescent platinum binuclear complexes. The major theme of this thesis is the design and optimization of a novel architecture where individual red, green and blue phosphorescent OLEDs are vertically stacked and electrically interconnected by the compound charge generation layers. We modeled carrier generation from the metal-oxide/doped organic interface based on a thermally assisted tunneling mechanism. The model provides insights to the optimization of a stacked OLED from both electrical and optical point of view. To realize the high intensity white lighting source, the efficient removal of heat is of a particular concern, especially in large-area devices. A fundamental transfer matrix analysis is introduced to predict the thermal properties in the devices. The analysis employs Laplace transforms to determine the response of the system to the combined effects of conduction, convection, and radiation. This perspective of constructing transmission matrices greatly facilitates the calculation of transient coupled heat transfer in a general multi-layer composite. It converts differential equations to algebraic forms, and

  10. Measurement-device-independent quantum key distribution with correlated source-light-intensity errors

    NASA Astrophysics Data System (ADS)

    Jiang, Cong; Yu, Zong-Wen; Wang, Xiang-Bin

    2018-04-01

    We present an analysis for measurement-device-independent quantum key distribution with correlated source-light-intensity errors. Numerical results show that the results here can greatly improve the key rate especially with large intensity fluctuations and channel attenuation compared with prior results if the intensity fluctuations of different sources are correlated.

  11. Absolute continuum intensity diagnostics of a novel large coaxial gridded hollow cathode argon plasma

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gao, Ruilin; Yuan, Chengxun, E-mail: yuancx@hit.edu.cn, E-mail: zhouzx@hit.edu.cn; Jia, Jieshu

    2016-08-15

    This paper reports a novel coaxial gridded hollow discharge during operation at low pressure (20 Pa–80 Pa) in an argon atmosphere. A homogeneous hollow discharge was observed under different conditions, and the excitation mechanism and the discharge parameters for the hollow cathode plasma were examined at length. An optical emission spectrometry (OES) method, with a special focus on absolute continuum intensity method, was employed to measure the plasma parameters. The Langmuir probe measurement (LPM) was used to verify the OES results. Both provided electron density values (n{sub e}) in the order of 10{sup 16} m{sup −3} for different plasma settings. Taken together, themore » results show that the OES method is an effective approach to diagnosing the similar plasma, especially when the LPM is hardly operated.« less

  12. Light alters nociceptive effects of magnetic field shielding in mice: intensity and wavelength considerations

    PubMed Central

    Prato, Frank S; Desjardins-Holmes, Dawn; Keenliside, Lynn D; McKay, Julia C; Robertson, John A; Thomas, Alex W

    2008-01-01

    Previous experiments with mice have shown that repeated 1 hour daily exposure to an ambient magnetic field-shielded environment induces analgesia (antinociception). The exposures were carried out in the dark (less than 2.0×1016 photons s−1 m−2) during the mid-light phase of the diurnal cycle. However, if the mice were exposed in the presence of visible light (2.0×1018 photons s−1 m−2, 400–750 nm), then the analgesic effects of shielding were eliminated. Here, we show that this effect of light is intensity and wavelength dependent. Introduction of red light (peak at 635 nm) had little or no effect, presumably because mice do not have photoreceptors sensitive to red light above 600 nm in their eyes. By contrast, introduction of ultraviolet light (peak at 405 nm) abolished the effect, presumably because mice do have ultraviolet A receptors. Blue light exposures (peak at 465 nm) of different intensities demonstrate that the effect has an intensity threshold of approximately 12% of the blue light in the housing facility, corresponding to 5×1016 photons s−1 m−2 (integral). This intensity is similar to that associated with photoreceptor-based magnetoreception in birds and in mice stimulates photopic/cone vision. Could the detection mechanism that senses ambient magnetic fields in mice be similar to that in bird navigation? PMID:18583276

  13. Effects of light intensity and quality on phycobiliprotein accumulation in the cyanobacterium Nostoc sphaeroides Kützing.

    PubMed

    Ma, Rui; Lu, Fan; Bi, Yonghong; Hu, Zhengyu

    2015-08-01

    To assess the effects of light intensity and quality on the growth and phycobiliproteins (PBP) accumulation in Nostoc sphaeroides Kützing (N. sphaeroides). Dry weights, dry matter, protein, chlorophyll and PBP contents were higher under 90 μmol m(-2) s(-1) than under other intensities (both higher and lower). Phycocyanin and allophycocyanin increased with light intensity while phycoerythrin decreased. Fresh weights, protein and PBP contents increased at the highest rates under blue light. Red light resulted in higher values of dry matter, phycocyanin and chlorophyll a. White light at 90 μmol m(-2) s(-1) or blue light 30 μmol m(-2) s(-1) were optimal for the growth and phycobiliprotein accumulation in N. sphaeroides.

  14. Alterations of the lipid content and fatty acid profile of Chlorella protothecoides under different light intensities.

    PubMed

    Krzemińska, Izabela; Piasecka, Agata; Nosalewicz, Artur; Simionato, Diana; Wawrzykowski, Jacek

    2015-11-01

    Chlorella protothecoides is a valuable source of lipids that may be used for biodiesel production. The present work shows analysis of the potential of photoheterotrophic cultivation of C. protothecoides under various light intensities aiming to identify the conditions with maximal biomass and lipid content. An increase in light intensity was associated with an increased specific growth rate and a shortened doubling time. Also, the relative total lipid content increased from 24.8% to 37.5% with increase of light intensity. The composition of fatty acid methyl esters was affected by light intensity with the C16-18 fatty acids increased from 76.97% to 90.24% of total fatty acids. However, the content of linolenic acids decreased with the increase of the culture irradiance. These studies indicate that cultures irradiated with high light intensities achieve the minimal specifications for biodiesel quality on linolenic acids and thus are suitable for biodiesel production. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Effects of forward and backward transitions in light intensities in tau-illuminance curves of the rat motor activity rhythm under constant dim light.

    PubMed

    Cambras, Trinitat; Díez-Noguera, Antoni

    2012-07-01

    Circadian rhythms are strongly influenced by light intensity, the effects of which may persist beyond the duration of light exposure (aftereffects). Here, the authors constructed period-illuminance curves for the motor activity circadian rhythm of male and female rats by recording the effects of a series of small upward and downward steps in light intensity (illuminance ranging between .01 lux of dim red light and 1 lux of white light) on their activity. In all cases, stepwise changes were made in five logarithmic steps (irradiance: dim red light: .692 µW/cm(2) and white light: .006, .016, .044, .12, and .315 µW/cm(2), corresponding, respectively, to .02, .05, .14, .13, and 1 lux measured at cage level), with changes in intensity every 2 wks. One group of rats (DLD) started in dim red light, moved up to 1 lux white light, and then back down to the original light intensity. Another group (LDL) started at 1 lux, moved down to .01 lux, and then back up to the original intensity. Motor activity data were recorded throughout the experiment and tau values, the percentage of variance explained by the rhythm, and the mean motor activity for each stage and group were calculated. The results show differences in the dynamics of tau values between the DLD and LDL groups and between males and females. In the LDL group, the tau values of both males and females were dependent on light intensity, and were similar for the forward and backward transitions. In other words, no aftereffects were found, and no differences were detected between males and females. In the DLD group, however, differences were found between males and females. Males had a tau value of 24 h 20 min under dim red light, 25 h 40 min under 1 lux, and 24 h 50 min on return to dim red light. It is noticeable that the tau values of the backward branch of the illuminance curve contradicted classical predictions, since at .38 and .14 lux the tau values were shorter than those found under the same intensities after

  16. High light intensity protects photosynthetic apparatus of pea plants against exposure to lead.

    PubMed

    Romanowska, E; Wróblewska, B; Drozak, A; Siedlecka, M

    2006-01-01

    The electron transport rates and coupling factor activity in the chloroplasts; adenylate contents, rates of photosynthesis and respiration in the leaves as well as activity of isolated mitochondria were investigated in Pisum sativum L. leaves of plants grown under low or high light intensity and exposed after detachment to 5 mM Pb(NO(3))(2). The presence of Pb(2+) reduced rate of photosynthesis in the leaves from plants grown under the high light (HL) and low light (LL) conditions, whereas the respiration was enhanced in the leaves from HL plants. Mitochondria from Pb(2+) treated HL-leaves oxidized glycine at a higher rate than those isolated from LL leaves. ATP content in the Pb-treated leaves increased to a greater extend in the HL than LL grown plants. Similarly ATP synthase activity increased markedly when chloroplasts isolated from control and Pb-treated leaves of HL and LL grown plants were subjected to high intensity light. The presence of Pb ions was found inhibit ATP synthase activity only in chloroplasts from LL grown plants or those illuminated with low intensity light. Low light intensity during growth also lowered PSI electron transport rates and the Pb(2+) induced changes in photochemical activity of this photosystem were visible only in the chloroplasts isolated from LL grown plants. The activity of PSII was influenced by Pb ions on similar manner in both light conditions. This study demonstrates that leaves from plants grown under HL conditions were more resistant to lead toxicity than those obtained from the LL grown plants. The data indicate that light conditions during growth might play a role in regulation of photosynthetic and respiratory energy conservation in heavy metal stressed plants by increasing the flexibility of the stoichiometry of ATP to ADP production.

  17. Acclimation of Swedish and Italian ecotypes of Arabidopsis thaliana to light intensity.

    PubMed

    Stewart, Jared J; Polutchko, Stephanie K; Adams, William W; Demmig-Adams, Barbara

    2017-11-01

    This study addressed whether ecotypes of Arabidopsis thaliana from Sweden and Italy exhibited differences in foliar acclimation to high versus low growth light intensity, and compared CO 2 uptake under growth conditions with light- and CO 2 -saturated intrinsic photosynthetic capacity and leaf morphological and vascular features. Differential responses between ecotypes occurred mainly at the scale of leaf architecture, with thicker leaves with higher intrinsic photosynthetic capacities and chlorophyll contents per leaf area, but no difference in photosynthetic capacity on a chlorophyll basis, in high light-grown leaves of the Swedish versus the Italian ecotype. Greater intrinsic photosynthetic capacity per leaf area in the Swedish ecotype was accompanied by a greater capacity of vascular infrastructure for sugar and water transport, but this was not associated with greater CO 2 uptake rates under growth conditions. The Swedish ecotype with its thick leaves is thus constructed for high intrinsic photosynthetic and vascular flux capacity even under growth chamber conditions that may not permit full utilization of this potential. Conversely, the Swedish ecotype was less tolerant of low growth light intensity than the Italian ecotype, with smaller rosette areas and lesser aboveground biomass accumulation in low light-grown plants. Foliar vein density and stomatal density were both enhanced by high growth light intensity with no significant difference between ecotypes, and the ratio of water to sugar conduits was also similar between the two ecotypes during light acclimation. These findings add to the understanding of the foliar vasculature's role in plant photosynthetic acclimation and adaptation.

  18. Light intensity affects RNA silencing of a transgene in Nicotiana benthamiana plants.

    PubMed

    Kotakis, Christos; Vrettos, Nicholas; Kotsis, Dimitrios; Tsagris, Mina; Kotzabasis, Kiriakos; Kalantidis, Kriton

    2010-10-12

    Expression of exogenous sequences in plants is often suppressed through one of the earliest described RNA silencing pathways, sense post-transcriptional gene silencing (S-PTGS). This type of suppression has made significant contributions to our knowledge of the biology of RNA silencing pathways and has important consequences in plant transgenesis applications. Although significant progress has been made in recent years, factors affecting the stability of transgene expression are still not well understood. It has been shown before that the efficiency of RNA silencing in plants is influenced by various environmental factors. Here we report that a major environmental factor, light intensity, significantly affects the induction and systemic spread of S-PTGS. Moreover, we show that photoadaptation to high or low light intensity conditions differentially affects mRNA levels of major components of the RNA silencing machinery. Light intensity is one of the previously unknown factors that affect transgene stability at the post-transcriptional level. Our findings demonstrate an example of how environmental conditions could affect RNA silencing.

  19. A light intensity monitoring method based on fiber Bragg grating sensing technology and BP neural network

    NASA Astrophysics Data System (ADS)

    Li, Lu-Ming; Zhu, Qian; Zhang, Zhi-Guo; Cai, Zhi-Min; Liao, Zhi-Jun; Hu, Zhen-Yan

    2017-04-01

    In this paper, a light intensity monitoring method based on FBG is proposed. The method establishes a light intensity monitoring model with cantilever beam structure and BP neural network algorithm, which is based on fiber grating sensing technology. The accuracy of the model can meet the requirements of engineering project and it can monitor light intensity in real time. The experimental results show that the method has good stability and high sensitivity.

  20. Development of a digital astronomical intensity interferometer: laboratory results with thermal light

    NASA Astrophysics Data System (ADS)

    Matthews, Nolan; Kieda, David; LeBohec, Stephan

    2018-06-01

    We present measurements of the second-order spatial coherence function of thermal light sources using Hanbury-Brown and Twiss interferometry with a digital correlator. We demonstrate that intensity fluctuations between orthogonal polarizations, or at detector separations greater than the spatial coherence length of the source, are uncorrelated but can be used to reduce systematic noise. The work performed here can readily be applied to existing and future Imaging Air-Cherenkov Telescopes used as star light collectors for stellar intensity interferometry to measure spatial properties of astronomical objects.

  1. Evaluation of light intensity output of QTH and LED curing devices in various governmental health institutions.

    PubMed

    Al Shaafi, Mm; Maawadh, Am; Al Qahtani, Mq

    2011-01-01

    The purpose of this study was to evaluate the light intensity output of quartz-tungsten-halogen (QTH) and light emitting diode (LED) curing devices located at governmental health institutions in Riyadh, Saudi Arabia.Eight governmental institutions were involved in the study. The total number of evaluated curing devices was 210 (120 were QTH and 90 were LED). The reading of the light intensity output for each curing unit was achieved using a digital spectrometer; (Model USB4000 Spectrometer, Ocean Optics Inc, Dunedin, FL, USA). The reading procedure was performed by a single investigator; any recording of light intensity below 300 mW/cm2 was considered unsatisfactory.The result found that the recorded mean values of light intensity output for QTH and LED devices were 260 mW/cm2 and 598 mW/cm2, respectively. The percentage of QTH devices and LED devices considered unsatisfactory was 67.5% and 15.6%, respectively. Overall, the regular assessment of light curing devices using light meters is recommended to assure adequate output for clinical use.

  2. High Intensity Lights

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Xenon arc lamps developed during the Apollo program by Streamlight, Inc. are the basis for commercial flashlights and emergency handlights. These are some of the brightest portable lights made. They throw a light some 50 times brighter than automobile high beams and are primarily used by police and military. The light penetrates fog and smoke and returns less back-scatter light. They are operated on portable power packs as boat and auto batteries. An infrared model produces totally invisible light for covert surveillance.

  3. Absolute colorimetric characterization of a DSLR camera

    NASA Astrophysics Data System (ADS)

    Guarnera, Giuseppe Claudio; Bianco, Simone; Schettini, Raimondo

    2014-03-01

    A simple but effective technique for absolute colorimetric camera characterization is proposed. It offers a large dynamic range requiring just a single, off-the-shelf target and a commonly available controllable light source for the characterization. The characterization task is broken down in two modules, respectively devoted to absolute luminance estimation and to colorimetric characterization matrix estimation. The characterized camera can be effectively used as a tele-colorimeter, giving an absolute estimation of the XYZ data in cd=m2. The user is only required to vary the f - number of the camera lens or the exposure time t, to better exploit the sensor dynamic range. The estimated absolute tristimulus values closely match the values measured by a professional spectro-radiometer.

  4. 14 CFR 29.1391 - Minimum intensities in the horizontal plane of forward and rear position lights.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Minimum intensities in the horizontal plane of forward and rear position lights. 29.1391 Section 29.1391 Aeronautics and Space FEDERAL AVIATION... Equipment Lights § 29.1391 Minimum intensities in the horizontal plane of forward and rear position lights...

  5. 14 CFR 25.1391 - Minimum intensities in the horizontal plane of forward and rear position lights.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Minimum intensities in the horizontal plane of forward and rear position lights. 25.1391 Section 25.1391 Aeronautics and Space FEDERAL AVIATION... Equipment Lights § 25.1391 Minimum intensities in the horizontal plane of forward and rear position lights...

  6. 14 CFR 27.1391 - Minimum intensities in the horizontal plane of forward and rear position lights.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Minimum intensities in the horizontal plane of forward and rear position lights. 27.1391 Section 27.1391 Aeronautics and Space FEDERAL AVIATION... Equipment Lights § 27.1391 Minimum intensities in the horizontal plane of forward and rear position lights...

  7. 14 CFR 27.1393 - Minimum intensities in any vertical plane of forward and rear position lights.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Minimum intensities in any vertical plane of forward and rear position lights. 27.1393 Section 27.1393 Aeronautics and Space FEDERAL AVIATION... Equipment Lights § 27.1393 Minimum intensities in any vertical plane of forward and rear position lights...

  8. 14 CFR 29.1393 - Minimum intensities in any vertical plane of forward and rear position lights.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Minimum intensities in any vertical plane of forward and rear position lights. 29.1393 Section 29.1393 Aeronautics and Space FEDERAL AVIATION... Equipment Lights § 29.1393 Minimum intensities in any vertical plane of forward and rear position lights...

  9. 14 CFR 25.1393 - Minimum intensities in any vertical plane of forward and rear position lights.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Minimum intensities in any vertical plane of forward and rear position lights. 25.1393 Section 25.1393 Aeronautics and Space FEDERAL AVIATION... Equipment Lights § 25.1393 Minimum intensities in any vertical plane of forward and rear position lights...

  10. Increased collection efficiency of LIFI high intensity electrodeless light source

    NASA Astrophysics Data System (ADS)

    Hafidi, Abdeslam; DeVincentis, Marc; Duelli, Markus; Gilliard, Richard

    2008-02-01

    Recently, RF driven electrodeless high intensity light sources have been implemented successfully in the projection display systems for HDTV and videowall applications. This paper presents advances made in the RF waveguide and electric field concentrator structures with the purpose of reducing effective arc size and increasing light collection. In addition, new optical designs are described that further improve system efficiency. The results of this work demonstrate that projection system light throughput is increased relative to previous implementations and performance is optimized for home theater and other front projector applications that maintain multi-year lifetime without re-lamping, complete spectral range, fast start times and high levels of dynamic contrast due to dimming flexibility in the light source system.

  11. Noncoherent-intense-pulsed light for the treatment of relapsing hairy intradermal melanocytic nevus after shave excision.

    PubMed

    Moreno-Arias, G A; Ferrando, J

    2001-01-01

    Few reports about melanocytic lesions treatment by means of noncoherent-intense-pulsed light (NCIPL) have been published. Here we evaluate the clinical results of a relapsing hairy intradermal melanocytic nevus treated with a noncoherent-intense-pulsed light source. A facial repigmented hairy intradermal melanocytic nevus that relapsed after shave excision, received four treatment sessions of a noncoherent-intense-pulsed light source (EpiLight, ESC Medical Systems Ltd, Israel) with the following parameters: 755 nm, a fluence energy of 40-42.5 J/cm(2), triple mode, a pulse width of 3.8 ms, and a delay of 20 ms, at 4-week intervals. Complete pigment clearance and hair removal was obtained. We have neither observed repigmentation nor hair regrowth after a 6 month-follow-up. No side effects were documented. Noncoherent-intense-pulse light is an effective treatment for hairy-pigmented melanocytic nevus. Copyright 2001 Wiley-Liss, Inc.

  12. The influence of reduced light intensity on the response of benthic diatoms to herbicide exposure.

    PubMed

    Wood, Rebecca J; Mitrovic, Simon M; Lim, Richard P; Kefford, Ben J

    2016-09-01

    Herbicide pollution events in aquatic ecosystems often coincide with increased turbidity and reduced light intensity. It is therefore important to determine whether reduced light intensity can influence herbicide toxicity, especially to primary producers such as benthic diatoms. Benthic diatoms collected from 4 rivers were exposed to herbicides in 48 h rapid toxicity tests under high light (100 µmol m(-2)  s(-1) ) and low light (20 µmol m(-2)  s(-1) ) intensities. The effects of 2 herbicides (atrazine and glyphosate) were assessed on 26 freshwater benthic diatom taxa. There was no significant interaction of light and herbicide effects at the community level or on the majority (22 of 26) of benthic diatom taxa. This indicates that low light levels will likely have only a minor influence on the response of benthic diatoms to herbicides. Environ Toxicol Chem 2016;35:2252-2260. © 2016 SETAC. © 2016 SETAC.

  13. Suppression of mutants aberrant in light intensity responses of complementary chromatic adaptation.

    PubMed Central

    Casey, E S; Kehoe, D M; Grossman, A R

    1997-01-01

    Complementary chromatic adaptation is a process in which cyanobacteria alter the pigment protein (phycocyanin and phycoerythrin) composition of their light-harvesting complexes, the phycobilisomes, to help optimize the absorbance of prevalent wavelengths of light in the environment. Several classes of mutants that display aberrant complementary chromatic adaptation have been isolated. One of the mutant classes, designated "blue" or FdB, accumulates high levels of the blue chromoprotein phycocyanin in low-intensity green light, a condition that normally suppresses phycocyanin synthesis. We demonstrate here that the synthesis of the phycocyanin protein and mRNA in the FdB mutants can be suppressed by increasing the intensity of green light. Hence, these mutants have a decreased sensitivity to green light with respect to suppression of phycocyanin synthesis. Although we were unable to complement the blue mutants, we did isolate genes that could suppress the mutant phenotype. These genes, which have been identified previously, encode a histidine kinase sensor and response regulator protein that play key roles in controlling complementary chromatic adaptation. These findings are discussed with respect to the mechanism by which light quality and quantity control the biosynthesis of the phycobilisome. PMID:9226271

  14. Marginal eyespots on butterfly wings deflect bird attacks under low light intensities with UV wavelengths.

    PubMed

    Olofsson, Martin; Vallin, Adrian; Jakobsson, Sven; Wiklund, Christer

    2010-05-24

    Predators preferentially attack vital body parts to avoid prey escape. Consequently, prey adaptations that make predators attack less crucial body parts are expected to evolve. Marginal eyespots on butterfly wings have long been thought to have this deflective, but hitherto undemonstrated function. Here we report that a butterfly, Lopinga achine, with broad-spectrum reflective white scales in its marginal eyespot pupils deceives a generalist avian predator, the blue tit, to attack the marginal eyespots, but only under particular conditions-in our experiments, low light intensities with a prominent UV component. Under high light intensity conditions with a similar UV component, and at low light intensities without UV, blue tits directed attacks towards the butterfly head. In nature, birds typically forage intensively at early dawn, when the light environment shifts to shorter wavelengths, and the contrast between the eyespot pupils and the background increases. Among butterflies, deflecting attacks is likely to be particularly important at dawn when low ambient temperatures make escape by flight impossible, and when insectivorous birds typically initiate another day's search for food. Our finding that the deflective function of eyespots is highly dependent on the ambient light environment helps explain why previous attempts have provided little support for the deflective role of marginal eyespots, and we hypothesize that the mechanism that we have discovered in our experiments in a laboratory setting may function also in nature when birds forage on resting butterflies under low light intensities.

  15. Universal sensitivity of speckle intensity correlations to wavefront change in light diffusers

    PubMed Central

    Kim, KyungDuk; Yu, Hyeonseung; Lee, KyeoReh; Park, YongKeun

    2017-01-01

    Here, we present a concept based on the realization that a complex medium can be used as a simple interferometer. Changes in the wavefront of an incident coherent beam can be retrieved by analyzing changes in speckle patterns when the beam passes through a light diffuser. We demonstrate that the spatial intensity correlations of the speckle patterns are independent of the light diffusers, and are solely determined by the phase changes of an incident beam. With numerical simulations using the random matrix theory, and an experimental pressure-driven wavefront-deforming setup using a microfluidic channel, we theoretically and experimentally confirm the universal sensitivity of speckle intensity correlations, which is attributed to the conservation of optical field correlation despite multiple light scattering. This work demonstrates that a light diffuser works as a simple interferometer, and presents opportunities to retrieve phase information of optical fields with a compact scattering layer in various applications in metrology, analytical chemistry, and biomedicine. PMID:28322268

  16. [Effects of light intensity on Quercus liaotungensis seed germination and seedling growth].

    PubMed

    Yan, Xing-fu; Wang, Jian-li; Zhou, Li-biao

    2011-07-01

    This paper studied the effects of different shading (55.4%, 18.9%, 5.5%, 2.2%, 0.5% , and 0.3% natural sunlight) on the seed germination and seedling growth of Quercus liaotungensis. The seed germination rate and germination index were the highest (72.5% and 0.22, respectively) at 55.4% natural sunlight, declined with decreasing light intensity, and were the lowest (42.5% and 0.11, respectively) at 0.3% natural sunlight. Strong light had definite delaying effect on the germination. The index of germination vigor increased with decreasing light intensity, being the maximum at 0.5% natural sunlight. The delay of seed germination under strong light could be the selective tradeoff on varied seed fates. Strong light benefited the basal stem diameter and root system growth and dry mass accumulation of Q. liaotunensis seedling, but resulted in the minimum seedlings height (6.06 cm). Greater morphological plasticity was observed for the seedlings under different shading, which lent support to the higher adaptability of the seedlings to light environment. For example, the specific leaf area, specific shoot length, specific root length, and chlorophyll b and total chlorophyll contents were the maximum at 0.5% natural sunlight, being 142.57 cm2 x g(-1), 156.86 cm x g(-1), 271.87 cm x g(-1), 0.07 g x cm(-2), and 0.24 g x cm(-2), respectively, and the minimum at 55.4% natural sunlight, being 44.89 cm2 x g(-1), 52.84 cm x g(-1), 101.98 cm x g(-1), 0.04 g x cm(-2), and 0.15 g x cm(-2), respectively. The variation of the root/shoot ratio of Q. liaotungensis seedlings under different shading could be the effects of the combination of light intensity and water availability.

  17. Influence of light intensity and water content of medium on total dendrobine of Dendrobium nobile Lindl.

    PubMed

    Li, Jin-Ling; Zhao, Zhi; Liu, Hong-Chang; Luo, Chun-Li; Wang, Hua-Lei

    2017-11-01

    To ascertain the influence of light intensity and water content of medium on the total dendrobine of Dendrobium nobile (D. nobile). The principal component analysis combined with total dendrobine accumulation was conducted to assess the yield and quality of D. nobile in all treatments. In the experiment, D. nobile plants were cultivated in greenhouse as tested materials, and complete test of 9 treatments was adopted with relative light intensities 75.02%, 39.74%, 29.93% and relative water content of medium 50%, 65%, 80%. The plants were treated in June and harvested till December. Indexes including agronomic traits, fresh weight and dry weight of stem and leaf, ash content, extract, and dendrobine were measured. Under the light intensity treatments of 75.02% with 50%, 65%, 80% water content of medium, the basal stems of plants were comparatively thicker with more leaves, and the fresh weight and dry weight of stems and leaves were significantly higher than other 6 treatments. Leaves in all treatments contained dendrobine. Under the light intensity treatments of 75.02% with 50%, 65%, 80% water content of medium, dendrobine content of leaves was lower while dendrobine contents of other treatments were more than 0.60%. After comprehensive assessment through the principal component analysis and total dendrobine accumulation, the results showed that 3 treatments with relative light intensity of 75.02% ranked the top three. In brief, the moderately strong light intensity and water content of medium from low to medium can facilitate the growth and yield of D. nobile plants, while light intensity from moderately weak to weak can enhance the dendrobine content. Copyright © 2017 Hainan Medical University. Production and hosting by Elsevier B.V. All rights reserved.

  18. Effect of light intensity on ovarian gene expression, reproductive performance and body weight of rabbit does.

    PubMed

    Sun, Liangzhan; Wu, Zhenyu; Li, Fuchang; Liu, Lei; Li, Jinglin; Zhang, Di; Sun, Chaoran

    2017-08-01

    The objective of the experiment was to find the minimum light intensity which could improve reproduction by examining its effect on ovarian gene expression, reproductive performance and body weight of rabbit does with three different light intensities: 60 (L), 80 (M), and 100 (H)lx. A total of 144 Rex-rabbits submitted to a 49-day reproductive regimen were used in this study. Ovaries were collected and relative abundance of mRNA for ovarian proteins of interest was examined with real-time PCR. Amount of protein for proteins of interest was examined by immunohistochemistry. Reproductive performance and doe bodyweight of the first three consecutive reproductive periods after initiation of the light intensity treatments were evaluated. The results provided evidence that light intensity had no effect on relative abundance of estradiol receptor-α (ER-α), follicle stimulating hormone receptor (FSHR), luteinizing hormone receptor (LHR), gonadotropin releasing hormone receptor 1 (GnRHR1) and progesterone receptor (PGR) mRNA. The relative abundance of growth hormone receptor (GHR) mRNA was, however, greater in Group L than M and H (P<0.05). No difference was observed for all reproductive indices as a result of submission to the three light intensities (P>0.05). The bodyweight of the does in Group L was greater than the other two groups at first insemination, second insemination and the second postpartum period (P<0.05). There was no difference in bodyweight after the second postpartum period (P>0.05). These observations suggest that light intensity between 60 and 100lx has no effect on the reproductive performance of rabbit does, however, the amounts of GHR mRNA and growth hormone (GH) protein were affected and the greater light intensity had a negative effect on bodyweight between the time of the first insemination and the second partum period. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. The Absolute Spectrum Polarimeter (ASP)

    NASA Technical Reports Server (NTRS)

    Kogut, A. J.

    2010-01-01

    The Absolute Spectrum Polarimeter (ASP) is an Explorer-class mission to map the absolute intensity and linear polarization of the cosmic microwave background and diffuse astrophysical foregrounds over the full sky from 30 GHz to 5 THz. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r much greater than 1O(raised to the power of { -3}) and Compton distortion y < 10 (raised to the power of{-6}). We describe the ASP instrument and mission architecture needed to detect the signature of an inflationary epoch in the early universe using only 4 semiconductor bolometers.

  20. [Effects of light intensity on growth and photosynthetic characteristics of Tulipa edulis].

    PubMed

    Xu, Hongjian; Zhu, Zaibiao; Guo, Qiaosheng; Wu, Zhengjun; Ma, Hongliang; Miao, Yuanyuan

    2012-02-01

    Present study was conducted to explore the growth and photosynthetic characteristics of Tulipa edulis under different light conditions (23%, 45%, 63%, 78%, 100% of full sunlight) and to determine the optimum light intensity for growth of T. edulis. The leaf area and biomass indicators as well as reproductive characteristics were measured. The photosynthetic basic parameters and light response curve were determined by a LI-6400XT portable photosynthesis system, and the light response curve characteristic parameters was determined. Additionally, chlorophyll fluorescence parameters were determined by assorted fluorescence leaf chamber of LI-6400XT. The lowest biomass yield was observed in the 23% and 100% of full sunlight treatments while the highest value was found under the 78% of full sunlight conditions. With the reduction of light availability, the success rate of sexual reproduction, light saturation point (LSP) and light compensation point (LCP) reduced, while apparent quantum yield (AQY) increased. 23% and 45% of full sunlight treatments led to lower photosynthesis rate (Pn) and higher apparent quantum yield (AQY) in comparison with other treatents. The highest photosynthesis rate was observed in the 78% and 100% of full sunlight treatments. In addition, 78% of full sunlight treatments led to highest Fv/Fm, Fv'/Fm', PhiPS II, ETR, and qP. T. edulis was able to adapt in a wide range of light intensity, and 78% of full sunlinght was the most suitable light condition for growth of T. edulis.

  1. Effect of light Intensity and photoperiod on growth of Chlorella pyrenoidosa and CO2 Biofixation

    NASA Astrophysics Data System (ADS)

    Gunawan, Teuku Johar; Ikhwan, Yusni; Restuhadi, Fajar; Pato, Usman

    2018-02-01

    Microalgae have been viewed as one of potential solution for CO2 biofixation or CO2 sequestration. However, many factors need to be evaluated to support development of CO2 biofixation. One important environmental factor for the growth of micro algae is related with light requirement. The aim of this study was to evaluate the effect of light intensity and photoperiod on growth of Chlorellapyrenoidosa (C.pyrenoidosa) and CO2 biofixation. Experiments were carried out in 1000 mL semi batch photo bioreactors, purged continuously with air (0.034% CO2). An Experiment of Factorial Design was employed in which the light intensity was evaluated 4 level at 2000, 4000, 6000 and 8000 lux with 3 level of photo period at L/D (light /dark) 8 hours/16 hours; L/D 12 hours/12 hours and L/D 16 hours/8 hours. The result indicated that both light intensity and photo period had significant effect (p< 0.05) on growth of C. pyrenoidosa. However, the photo period showed stronger effect relative to light intensity on growth of C.pyrenoidosa within the range reviewed. The interaction between the two factors was indicative but statistically not significant. Best growth profile sustained at combination of L/D 16 hours/8 hours of photoperiod and light intensity of 8000 lux with the highest average biomass observed at 0.516 ± 0.069gr/L. An increase in CO2biofixation rate of around 2 times was also observed between highest setting (8000 lux; L/D 16/12 hours) relative to that of lowest setting (2000 lux; L/D 8/12 hours).

  2. Effect of Light Intensity and Photoperiod on Growth and Biochemical Composition of a Local Isolate of Nostoc calcicola.

    PubMed

    Khajepour, Fateme; Hosseini, Seyed Abbas; Ghorbani Nasrabadi, Rasoul; Markou, Giorgos

    2015-08-01

    A study was conducted to investigate the effect of light intensity (21, 42, and 63 μmol photons m(-2) s(-1)) and photoperiod (8:16, 12:12, and 16:8 h light/dark) on the biomass production and its biochemical composition (total carotenoids, chlorophyll a, phycoerythrin (PE), phycocyanin (PC) and allophycocyanin (APC), total protein, and carbohydrates) of a local isolate of Nostoc calcicola. The results revealed that N. calcicola prefers dim light; however, the most of the levels of light intensity and photoperiod investigated did not have a significant impact on biomass production. Increasing light intensity biomass content of chlorophyll a, PE, PC, APC, and total protein decreased, while total carotenoids and carbohydrate increased. The same behavior was observed also when light duration (photoperiod) increased. The interaction effect of increasing light intensity and photoperiod resulted in an increase of carbohydrate and total carotenoids, and to the decrease of chlorophyll a, PE, PC, APC, and total protein content. The results indicate that varying the light regime, it is capable to manipulate the biochemical composition of the local isolate of N. calcicola, producing either valuable phycobiliproteins or proteins under low light intensity and shorter photoperiods, or producing carbohydrates and carotenoids under higher light intensities and longer photoperiods.

  3. The effect of low light intensity on the maintenance of circadian synchrony in human subjects

    NASA Technical Reports Server (NTRS)

    Winget, C. M.; Lyman, J.; Beljan, J. R.

    1976-01-01

    Experiments were conducted on six healthy male subjects aged 20-23 yr and exposed for 21 days in a confined regulated environment to 16L:8D light:dark cycle with a view toward determining whether the light environment of 16L:8D at the relatively low light intensity of 15 ft.c. is adequate for the maintenance of circadian synchrony in man. The light intensity was 100 ft.c. during the first seven days, reduced to 15 ft.c. during the next seven days, and increased again to 100 ft.c. during the last seven days. Rectal temperature (RT) and heart rate (HR) were recorded throughout the three phases. In the 100 ft.c. regime, the RT and HR rhythms remained stable and circadian throughout. It is shown that 15 ft.c. light intensity is at or below threshold for maintaining circadian synchrony of human physiologic rhythms marked by instability and internal desynchronization with degradation of performance and well-being.

  4. Effects of Light Intensity and Color on the Biomass, Extracellular Red Pigment, and Citrinin Production of Monascus ruber.

    PubMed

    Wang, Liling; Dai, Yang; Chen, Wanping; Shao, Yanchun; Chen, Fusheng

    2016-12-21

    Light is a crucial environmental signal for fungi. In this work, the effects of different light intensities and colors on biomass, Monascus pigments (MPs) and citrinin production of Monascus ruber M7 were investigated. We have demonstrated that low intensity of blue light (500 lx) decreased Monascus biomass, increased MPs accumulation via upregulation of MpigA, MpigB, and MpigJ genes expression, but had no significant influence on citrinin production. High intensity of blue light (1500 lx) decreased citrinin accumulation but had no significant influence on biomass and MPs production after 14 days cultivation. Low intensity of green light (500 lx) stimulated citrinin production via upregulation of pksCT, mrl1, mrl2, and ctnA genes expression. One putative red light photoreceptor and two putative green light photoreceptors were identified in M. ruber M7. These observations will not only guide the practical production of Monascus but also contribute to our understanding light effects on Monascus.

  5. Construction and temporal behaviour study of multi RLC intense light pulses for dermatological applications.

    PubMed

    Hamoudi, Walid K; Ismail, Raid A; Shakir, Hussein A

    2017-10-01

    Driving a flash lamp in an intense pulsed light system requires a high-voltage DC power supply, capacitive energy storage and a flash lamp triggering unit. Single, double, triple and quadruple-mesh discharge and triggering circuits were constructed to provide intense light pulses of variable energy and time durations. The system was treated as [Formula: see text] circuit in some cases and [Formula: see text] circuit in others with a light pulse profile following the temporal behaviour of the exciting current pulse. Distributing the energy delivered to one lamp onto a number of LC meshes permitted longer current pulses, and consequently increased the light pulse length. Positive results were obtained when using the system to treat skin wrinkles.

  6. Phytoplankton productivity in relation to light intensity: A simple equation

    USGS Publications Warehouse

    Peterson, D.H.; Perry, M.J.; Bencala, K.E.; Talbot, M.C.

    1987-01-01

    A simple exponential equation is used to describe photosynthetic rate as a function of light intensity for a variety of unicellular algae and higher plants where photosynthesis is proportional to (1-e-??1). The parameter ?? (=Ik-1) is derived by a simultaneous curve-fitting method, where I is incident quantum-flux density. The exponential equation is tested against a wide range of data and is found to adequately describe P vs. I curves. The errors associated with photosynthetic parameters are calculated. A simplified statistical model (Poisson) of photon capture provides a biophysical basis for the equation and for its ability to fit a range of light intensities. The exponential equation provides a non-subjective simultaneous curve fitting estimate for photosynthetic efficiency (a) which is less ambiguous than subjective methods: subjective methods assume that a linear region of the P vs. I curve is readily identifiable. Photosynthetic parameters ?? and a are used widely in aquatic studies to define photosynthesis at low quantum flux. These parameters are particularly important in estuarine environments where high suspended-material concentrations and high diffuse-light extinction coefficients are commonly encountered. ?? 1987.

  7. 14 CFR 23.1389 - Position light distribution and intensities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... overlapping beams, within dihedral angles L, R, and A, and must meet the following requirements: (1... clarity. When the peak intensity of the left and right position lights is more than 100 candles, the... the right and left of the axis of maximum illumination. [Doc. No. 4080, 29 FR 17955, Dec. 18, 1964, as...

  8. The effect of luminous intensity on the attraction of phlebotomine sand flies to light traps.

    PubMed

    Lima-Neto, Abdias R; Costa-Neta, Benedita M; da Silva, Apoliana Araújo; Brito, Jefferson M; Aguiar, João V C; Ponte, Islana S; Silva, Francinaldo S

    2018-05-04

    To improve the efficiency of light traps in collecting phlebotomine sand flies, the potential effects of luminous intensity on the attraction of these insects to traps were evaluated. Sand flies were collected with Hooper Pugedo (HP) light traps fitted with 5-mm light-emitting diodes (LED) bulbs: green (520 nm wavelength-10,000, 15,000 and 20,000 millicandela (mcd) and blue (470 nm-4,000, 12,000 and 15,000 mcd). A total of 3,264 sand flies comprising 13 species were collected. The collected species were Lutzomyia longipalpis (Lutz & Neiva) (Diptera: Psychodidae) (52.48%), Evandromyia evandroi (Costa Lima & Antunes, 1939) (Diptera: Psychodidae) (32.90%) and Micropygomyia goiana (Martins, Falcão, & Silva) (Diptera: Psychodidae) (9.76%). An increase in luminous intensity of the LEDs increased the size of the sand fly catch. The lower luminous intensity of green (10,000 mcd) attracted an average of 13.7 ± 2.8 sand flies/trap per night and the other luminous intensities accounted for a mean of 24.1 ± 4.0 (15,000 mcd) and 28.2 ± 5.0 (20,000 mcd) sand flies/trap per night. Regarding the blue wavelength, the lower luminous intensity (4,000 mcd) attracted an average of 27.4 ± 4.1 sand flies/trap per night, followed by 12,000 mcd (37.6 ± 8.7) and 15,000 mcd (40.5 ± 7.3). Based on our data, the luminous intensity of light traps should be considered when developing light traps for monitoring or controlling phlebotomine sand flies.

  9. Light intensity of 5 or 20 lux on broiler behavior, welfare and productivity.

    PubMed

    Rault, Jean-Loup; Clark, Katie; Groves, Peter J; Cronin, Greg M

    2017-04-01

    Light intensity can influence broiler behavior, but discrepancies in the scientific literature remain. Furthermore, few studies have investigated the welfare implications induced by varying light intensity. We investigated the effects of providing 5 or 20 lux light intensity on broiler behavior, welfare and productivity. A total of 1,872 Ross 308 broilers of mixed sex were studied across 2 replicates. Treatments began on d 8 with one of 2 light intensity levels: 5 lux or 20 lux, using LED lights on a 16L:8D photoperiod with 30 min sunrise and sunset periods. Production data, behavioral activity, and plasma samples for corticosterone concentration analysis were collected weekly from 8 to 46 d of age. Eye weight was collected at 42 d of age. Leg strength was assessed at 35, 42 and 45 d of age using the latency to lie test and leg and foot conditions (foot pad dermatitis, hock burn, leg straightness) were assessed at 46 d. Live weight differed between light treatments, with broilers kept at 20 lux being lighter than broilers kept at 5 lux at 46 d of age (males: -5.1%, females: -2.8%, P < 0.0001), despite no significant differences in feed intake. However, broilers kept at 20 lux were more active during the photophase than broilers kept at 5 lux throughout the rearing period (P < 0.0001). Eye weight was also on average 5% lighter for broilers kept at 20 lux compared to 5 lux (P = 0.001). Nonetheless, there was no significant effect of light intensity on other measures of broiler welfare: mortality and culls, plasma corticosterone concentrations, or latency to lie reflective of leg strength. Hence, broilers kept at 20 lux compared to 5 lux were found to be more active, had slower growth, and had lighter eye weight, but other welfare measures reflective of biological functioning or leg health did not show significant changes. © 2016 Poultry Science Association Inc.

  10. Development of Choroidal Neovascularization in rats with Advanced Intense Cyclic Light-induced Retinal Degeneration

    PubMed Central

    Albert, Daniel M.; Neekhra, Aneesh; Wang, Shoujian; Darjatmoko, Soesiawati R.; Sorenson, Christine M.; Dubielzig, Richard R.; Sheibani, Nader

    2010-01-01

    Objective To study the progressive changes of intense cyclic light-induced retinal degeneration and determine whether it results in choroidal neovascularization (CNV). Methods Albino rats were exposed to 12 h of 3000 lux cyclic light for 1, 3, or 6 months. Prior to euthanization, fundus examination, fundus photographs, fluorescein and indocyanine green angiography, and Optical Coherence Tomography (OCT) evaluations were performed. Light exposed animals were euthanized after 1, 3, or 6 months for histopathological evaluation. Retinas were examined for the presence of 4-hydroxy-2-nonenal (HNE) and nitrotyrosine modified proteins by immunofluorescence staining. Results Chronic intense cyclic light exposure resulted in retinal degeneration with loss of the outer segments of photoreceptors and approximately two-thirds of the outer nuclear layer (ONL) and development of sub-retinal pigment epithelium (RPE) neovascularization after 1 month. Almost the entire ONL was absent with the presence of CNV, which penetrated Bruch’s membrane and extended into the outer retina after 3 months. Absence of the ONL, multiple foci of CNV, RPE fibrous metaplasia, and connective tissue bands containing blood vessels extending into the retina were observed after 6 months. All intense light exposed animals showed an increased presence of HNE and nitrotyrosine staining. OCT and angiographic studies confirmed retinal thinning and leakiness of the newly fromed blood vessels. Conclusions Our results suggest albino rats develop progressive stages of retinal degeneration and CNV after chronic intense cyclic light exposure allowing the detailed study of the pathogenesis and treatment of age-related macular degeneration. PMID:20142545

  11. Light intensity related to stand density in mature stands of the western white pine type

    Treesearch

    C. A. Wellner

    1948-01-01

    Where tolerance of forest trees or subordinate vegetation is a factor in management, the forester needs a simple field method of Estimating or forecasting light intensities in forest stands. The following article describes a method developed for estimating light intensity beneath the canopy in western white pine forests which may have application in other types.

  12. 14 CFR 29.1393 - Minimum intensities in any vertical plane of forward and rear position lights.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Minimum intensities in any vertical plane... Equipment Lights § 29.1393 Minimum intensities in any vertical plane of forward and rear position lights... above or below the horizontal plane Intensity, I 0° 1.00 0° to 5° .90 5° to 10° .80 10° to 15° .70 15...

  13. Sound intensity probe for ultrasonic field in water using light-emitting diodes and piezoelectric elements

    NASA Astrophysics Data System (ADS)

    Zeng, Xi; Mizuno, Yosuke; Nakamura, Kentaro

    2017-12-01

    The sound intensity vector provides useful information on the state of an ultrasonic field in water, since sound intensity is a vector quantity expressing the direction and magnitude of the sound field. In the previous studies on sound intensity measurement in water, conventional piezoelectric sensors and metal cables were used, and the transmission distance was limited. A new configuration of a sound intensity probe suitable for ultrasonic measurement in water is proposed and constructed for trial in this study. The probe consists of light-emitting diodes and piezoelectric elements, and the output signals are transmitted through fiber optic cables as intensity-modulated light. Sound intensity measurements of a 26 kHz ultrasonic field in water are demonstrated. The difference in the intensity vector state between the water tank with and without sound-absorbing material on its walls was successfully observed.

  14. An evaluation of light intensity functions for determination of shaded reference stream metabolism.

    PubMed

    Zell, Chris; Hubbart, Jason A

    2012-04-30

    The performance of three single-station whole stream metabolism models were evaluated within three shaded, seasonally hypoxic, Missouri reference streams using high resolution (15-minute) dissolved oxygen (DO), temperature, and light intensity data collected during the summers (July-September) of 2006-2008. The model incorporating light intensity data consistently achieved a lower root mean square error (median RMSE = 0.20 mg L(-1)) relative to models assuming sinusoidal light intensity functions (median RMSE = 0.28 mg L(-1)) and constant diel temperature (median RMSE = 0.53 mg L(-1)). Incorporation of site-specific light intensity into metabolism models better predicted morning DO concentrations and exposure to hypoxic conditions in shaded study streams. Model choice significantly affected (p < 0.05) rate estimates for daily average photosynthesis. Low reaeration (pooled site mean 1.1 day(-1) at 20 °C) coupled with summer temperatures (pooled site mean = 25.8 °C) and low to moderate community respiration (site median 1.0-3.0 g O(2) m(-2) day(-1)) yielded diel dissolved oxygen concentrations near or below critical aquatic life thresholds in studied reference streams. Quantifying these process combinations in best-available or least-disturbed (i.e., reference) systems advances our understanding of regional dissolved oxygen expectations and informs environmental management policy. Additional research is warranted to better link landscape processes with distributed sources that contribute to community respiration. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. 14 CFR 25.1393 - Minimum intensities in any vertical plane of forward and rear position lights.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Minimum intensities in any vertical plane... Equipment Lights § 25.1393 Minimum intensities in any vertical plane of forward and rear position lights... above or below the horizontal plane Intensity, l 0° 1.00 0° to 5° 0.90 5° to 10° 0.80 10° to 15° 0.70 15...

  16. 14 CFR 27.1393 - Minimum intensities in any vertical plane of forward and rear position lights.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Minimum intensities in any vertical plane... Equipment Lights § 27.1393 Minimum intensities in any vertical plane of forward and rear position lights... above or below the horizontal plane Intensity, l 0° 1.00 0° to 5° 0.90 5° to 10° 0.80 10° to 15° 0.70 15...

  17. Generating structured light with phase helix and intensity helix using reflection-enhanced plasmonic metasurface at 2 μm

    NASA Astrophysics Data System (ADS)

    Zhao, Yifan; Du, Jing; Zhang, Jinrun; Shen, Li; Wang, Jian

    2018-04-01

    Mid-infrared (2-20 μm) light has been attracting great attention in many areas of science and technology. Beyond the extended wavelength range from visible and near-infrared to mid-infrared, shaping spatial structures may add opportunities to grooming applications of mid-infrared photonics. Here, we design and fabricate a reflection-enhanced plasmonic metasurface and demonstrate efficient generation of structured light with the phase helix and intensity helix at 2 μm. This work includes two distinct aspects. First, structured light (phase helix, intensity helix) generation at 2 μm, which is far beyond the ability of conventional spatial light modulators, is enabled by the metasurface with sub-wavelength engineered structures. Second, the self-referenced intensity helix against environmental noise is generated without using a spatially separated light. The demonstrations may open up advanced perspectives to structured light applications at 2 μm, such as phase helix for communications and non-communications (imaging, sensing) and intensity helix for enhanced microscopy and advanced metrology.

  18. Current indications and new applications of intense pulsed light.

    PubMed

    González-Rodríguez, A J; Lorente-Gual, R

    2015-06-01

    Intense pulsed light (IPL) systems have evolved since they were introduced into medical practice 20 years ago. Pulsed light is noncoherent, noncollimated, polychromatic light energy emitted at different wavelengths that target specific chromophores. This selective targeting capability makes IPL a versatile therapy with many applications, from the treatment of pigmented or vascular lesions to hair removal and skin rejuvenation. Its large spot size ensures a high skin coverage rate. The nonablative nature of IPL makes it an increasingly attractive alternative for patients unwilling to accept the adverse effects associated with other procedures, which additionally require prolonged absence from work and social activities. In many cases, IPL is similar to laser therapy in effectiveness, and its versatility, convenience, and safety will lead to an expanded range of applications and possibilities in coming years. Copyright © 2014 Elsevier España, S.L.U. and AEDV. All rights reserved.

  19. Development of an in-fiber white-light interferometric distance sensor for absolute measurement of arbitrary small distances.

    PubMed

    Majumdar, Ayan; Huang, Haiying

    2008-05-20

    The fabrication, implementation, and evaluation of an in-fiber white-light interferometric distance sensor that is capable of measuring the absolute value of an arbitrary small distance are presented. Taking advantage of the mode-coupling effect of a long-period fiber grating, an additional cavity distance is added to the optical path difference of the distance sensor; therefore, it can generate a sufficient number of fringes for distance demodulation even if the free-space cavity distance is very small. It is experimentally verified that the distance sensor is capable of measuring small distances that are beyond the capability of a Fabry-Perot interferometric distance sensor.

  20. Effects of day-time exposure to different light intensities on light-induced melatonin suppression at night.

    PubMed

    Kozaki, Tomoaki; Kubokawa, Ayaka; Taketomi, Ryunosuke; Hatae, Keisuke

    2015-07-04

    Bright nocturnal light has been known to suppress melatonin secretion. However, bright light exposure during the day-time might reduce light-induced melatonin suppression (LIMS) at night. The effective proportion of day-time light to night-time light is unclear; however, only a few studies on accurately controlling both day- and night-time conditions have been conducted. This study aims to evaluate the effect of different day-time light intensities on LIMS. Twelve male subjects between the ages of 19 and 23 years (mean ± S.D., 20.8 ± 1.1) gave informed consent to participate in this study. They were exposed to various light conditions (<10, 100, 300, 900 and 2700 lx) between the hours of 09:00 and 12:00 (day-time light conditions). They were then exposed to bright light (300 lx) again between 01:00 and 02:30 (night-time light exposure). They provided saliva samples before (00:55) and after night-time light exposure (02:30). A one-tailed paired t test yielded significant decrements of melatonin concentration after night-time light exposure under day-time dim, 100- and 300-lx light conditions. No significant differences exist in melatonin concentration between pre- and post-night-time light exposure under day-time 900- and 2700-lx light conditions. Present findings suggest the amount of light exposure needed to prevent LIMS caused by ordinary nocturnal light in individuals who have a general life rhythm (sleep/wake schedule). These findings may be useful in implementing artificial light environments for humans in, for example, hospitals and underground shopping malls.

  1. Attosecond control of electronic processes by intense light fields.

    PubMed

    Baltuska, A; Udem, Th; Uiberacker, M; Hentschel, M; Goulielmakis, E; Gohle, Ch; Holzwarth, R; Yakovlev, V S; Scrinzi, A; Hänsch, T W; Krausz, F

    2003-02-06

    The amplitude and frequency of laser light can be routinely measured and controlled on a femtosecond (10(-15) s) timescale. However, in pulses comprising just a few wave cycles, the amplitude envelope and carrier frequency are not sufficient to characterize and control laser radiation, because evolution of the light field is also influenced by a shift of the carrier wave with respect to the pulse peak. This so-called carrier-envelope phase has been predicted and observed to affect strong-field phenomena, but random shot-to-shot shifts have prevented the reproducible guiding of atomic processes using the electric field of light. Here we report the generation of intense, few-cycle laser pulses with a stable carrier envelope phase that permit the triggering and steering of microscopic motion with an ultimate precision limited only by quantum mechanical uncertainty. Using these reproducible light waveforms, we create light-induced atomic currents in ionized matter; the motion of the electronic wave packets can be controlled on timescales shorter than 250 attoseconds (250 x 10(-18) s). This enables us to control the attosecond temporal structure of coherent soft X-ray emission produced by the atomic currents--these X-ray photons provide a sensitive and intuitive tool for determining the carrier-envelope phase.

  2. Influence of light intensity on surface free energy and dentin bond strength of core build-up resins.

    PubMed

    Shimizu, Y; Tsujimoto, A; Furuichi, T; Suzuki, T; Tsubota, K; Miyazaki, M; Platt, J A

    2015-01-01

    We examined the influence of light intensity on surface free energy characteristics and dentin bond strength of dual-cure direct core build-up resin systems. Two commercially available dual-cure direct core build-up resin systems, Clearfil DC Core Automix with Clearfil Bond SE One and UniFil Core EM with Self-Etching Bond, were studied. Bovine mandibular incisors were mounted in acrylic resin and the facial dentin surfaces were wet ground on 600-grit silicon carbide paper. Adhesives were applied to dentin surfaces and cured with light intensities of 0 (no irradiation), 200, 400, and 600 mW/cm(2). The surface free energy of the adhesives (five samples per group) was determined by measuring the contact angles of three test liquids placed on the cured adhesives. To determine the strength of the dentin bond, the core build-up resin pastes were condensed into the mold on the adhesive-treated dentin surfaces according to the methods described for the surface free energy measurement. The resin pastes were cured with the same light intensities as those used for the adhesives. Ten specimens per group were stored in water maintained at 37°C for 24 hours, after which they were shear tested at a crosshead speed of 1.0 mm/minute in a universal testing machine. Two-way analysis of variance (ANOVA) and a Tukey-Kramer test were performed, with the significance level set at 0.05. The surface free energies of the adhesive-treated dentin surfaces decreased with an increase in the light intensity of the curing unit. Two-way ANOVA revealed that the type of core build-up system and the light intensity significantly influence the bond strength, although there was no significant interaction between the two factors. The highest bond strengths were achieved when the resin pastes were cured with the strongest light intensity for all the core build-up systems. When polymerized with a light intensity of 200 mW/cm(2) or less, significantly lower bond strengths were observed. CONClUSIONS: The

  3. Magnetic orientation in birds: non-compass responses under monochromatic light of increased intensity.

    PubMed

    Wiltschko, Wolfgang; Munro, Ursula; Ford, Hugh; Wiltschko, Roswitha

    2003-10-22

    Migratory Australian silvereyes (Zosterops lateralis) were tested under monochromatic light at wavelengths of 424 nm blue and 565 nm green. At a low light level of 7 x 10(15) quanta m(-2) s(-1) in the local geomagnetic field, the birds preferred their seasonally appropriate southern migratory direction under both wavelengths. Their reversal of headings when the vertical component of the magnetic field was inverted indicated normal use of the avian inclination compass. A higher light intensity of 43 x 10(15) quanta m(-2) s(-1), however, caused a fundamental change in behaviour: under bright blue, the silvereyes showed an axial tendency along the east-west axis; under bright green, they showed a unimodal preference of a west-northwesterly direction that followed a shift in magnetic north, but was not reversed by inverting the vertical component of the magnetic field. Hence it is not based on the inclination compass. The change in behaviour at higher light intensities suggests a complex interaction between at least two receptors. The polar nature of the response under bright green cannot be explained by the current models of light-dependent magnetoreception and will lead to new considerations on these receptive processes.

  4. Effect of light intensity on flight control and temporal properties of photoreceptors in bumblebees.

    PubMed

    Reber, Therese; Vähäkainu, Antti; Baird, Emily; Weckström, Matti; Warrant, Eric; Dacke, Marie

    2015-05-01

    To control flight, insects rely on the pattern of visual motion generated on the retina as they move through the environment. When light levels fall, vision becomes less reliable and flight control thus becomes more challenging. Here, we investigated the effect of light intensity on flight control by filming the trajectories of free-flying bumblebees (Bombus terrestris, Linnaeus 1758) in an experimental tunnel at different light levels. As light levels fell, flight speed decreased and the flight trajectories became more tortuous but the bees were still remarkably good at centring their flight about the tunnel's midline. To investigate whether this robust flight performance can be explained by visual adaptations in the bumblebee retina, we also examined the response speed of the green-sensitive photoreceptors at the same light intensities. We found that the response speed of the photoreceptors significantly decreased as light levels fell. This indicates that bumblebees have both behavioural (reduction in flight speed) and retinal (reduction in response speed of the photoreceptors) adaptations to allow them to fly in dim light. However, the more tortuous flight paths recorded in dim light suggest that these adaptations do not support flight with the same precision during the twilight hours of the day. © 2015. Published by The Company of Biologists Ltd.

  5. Absolute Soft X-ray Emission Measurements at the Nike Laser

    NASA Astrophysics Data System (ADS)

    Weaver, J.; Atkin, R.; Boyer, C.; Colombant, D.; Feldman, U.; Fielding, D.; Gardner, J.; Holland, G.; Klapisch, M.; Mostovych, A. N.; Obenscain, S.; Seely, J. F.

    2002-11-01

    Recent experiments at the Nike laser facility have demonstrated that, when a low intensity prepulse ( 2main laser intensity) is used to heat a thin Au or Pd coating on a planar CH target, the growth of non-uniformities due to laser imprint can be reduced from the growth observed for an uncoated CH target. The absolute radiation intensity in the soft x-ray region (0.1-1 keV) has a important role in the energy balance for layered targets. There is an ongoing effort to characterize the soft x-ray emission using an absolutely calibrated transmission grating spectrometer and filtered diode modules. Measurements of the angular distribution of the emission from unlayered solid targets (Au, Pd, CH) have recently been made using an array of moveable filtered diode modules. The data from the angular distribution studies will be presented. A new absolutely calibrated, time-resolving transmission grating spectrometer has been installed at the Nike. The new version has improved spectral resolution, selectable transmission filters, and the potential for simultaneous temporal, spatial, and spectral resolution. Preliminary data from the new spectrometer will be presented and future experiments will be briefly discussed. *Work was supported by DoE

  6. Effect of light intensity on food detection in captive great fruit-eating bats, Artibeus lituratus (Chiroptera: Phyllostomidae).

    PubMed

    Gutierrez, Eduardo de A; Pessoa, Valdir F; Aguiar, Ludmilla M S; Pessoa, Daniel M A

    2014-11-01

    Bats are known for their well-developed echolocation. However, several experiments focused on the bat visual system have shown evidence of the importance of visual cues under specific luminosity for different aspects of bat biology, including foraging behavior. This study examined the foraging abilities of five female great fruit-eating bats, Artibeus lituratus, under different light intensities. Animals were given a series of tasks to test for discrimination between a food target against an inedible background, under light levels similar to the twilight illumination (18lx), the full moon (2lx) and complete darkness (0lx). We found that the bats required a longer time frame to detect targets under a light intensity similar to twilight, possibly due to inhibitory effects present under a more intense light level. Additionally, bats were more efficient at detecting and capturing targets under light conditions similar to the luminosity of a full moon, suggesting that visual cues were important for target discrimination. These results demonstrate that light intensity affects foraging behavior and enables the use of visual cues for food detection in frugivorous bats. This article is part of a Special Issue entitled: Neotropical Behaviour. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Purifying synthetic high-strength wastewater by microalgae chlorella vulgaris under various light emitting diode wavelengths and intensities

    PubMed Central

    2013-01-01

    The high-strength wastewater is now well known as a threat to the natural water since it is highly possible to arouse water eutrophication or algal blooms. The effects of various light emitting diode wavelengths and intensities on the microalgae biological wastewater treatment system was studied in this research. The various nutrient removals and economic efficiencies represented similar variation trends, and these variations under both high C and N loading treatments were similar too. The order for microalgae C. vulgaris reproduction in terms of dry weight and nutrient removal efficiency both were red > white > yellow > blue, under high carbon and nitrogen loading treatments, indicating that the red light was the optimum light wavelength. Furthermore, considering the optimal light intensity in terms of nutrient removal efficiency was 2500 and 2000 μmol/m2•s, while in terms of economic efficiency was 1000, 1500 and 2000 μmol/m2•s. Therefore, the optimum light intensity was found to be 2000 μmol/m2•s. In addition, the optimal experimental illumination time was determined as 120 h. The Chlorella vulgaris microalgae biological wastewater treatment system utilized in this research was able to purify the high-strength carbon and nitrogen wastewater effectively under optimum light wavelength and intensity. PMID:24499586

  8. Effect of light intensity on the total lipid and fatty acid composition of six strains of marine diatoms

    NASA Astrophysics Data System (ADS)

    Liang, Ying; Mai, Kang-Sen; Sun, Shi-Chun; Yu, Dao-Zhan

    2001-09-01

    The effect of light intensity (1500 lx and 5000 lx) on the total lipid and fatty acid composition of six strains of marine diatoms Cylindrotheca fusiformis (B211), Phaeodactylum tricornutum (B114, B118 and B221) Nitzschia closterium (B222) and Chaetoceros gracilis (B13) was investigated. The total lipids of B13, B114, and B211 grown at 5000 lx were lower than those grown at 1500 lx. No evident changes were observed in B118, B221 and B222. Fatty acid composition changed considerably at different light intensity although no consistent correlation between the relative proportion of a single FA and light intensity. The major fatty acids of the 6 strains were 14∶0, 16∶0, 16∶1 (n-7) and 20∶5(n-3). Cylindrotheca fusiformis had high percentage of 20∶4n 6(9.2 10.9%). The total polyunsaturated fatty acid in all 6 strains decreased with increasing light intensity. The percentage of the highly unsaturated fatty acid eicosapentaenoic acid (EPA) decreased with increasing light intensity in all strains except Chaetoceros gracilis.

  9. Acne phototherapy using UV-free high-intensity narrow-band blue light: a three-center clinical study

    NASA Astrophysics Data System (ADS)

    Shalita, Alan R.; Harth, Yoram; Elman, Monica; Slatkine, Michael; Talpalariu, Gerry; Rosenberg, Yitzhak; Korman, Avner; Klein, Arieh

    2001-05-01

    Propionibacterium. acnes is a Gram positive, microaerophilic bacterium which takes a part in the pathogenesis of inflammatory acne. P. acnes is capable to produce high amounts endogenic porphyrins with no need of any trigger molecules. Light in the violet-blue range (407-420 nm) has been shown to exhibit a phototoxic effect on Propionibacterium acnes when irradiated in vitro. The purpose of our study was to test the clinical effects of a high intensity narrowband blue light source on papulo pustular acne. A total of 35 patients in 3 centers were treated twice a week with a high intensity metal halide lamp illuminating the entire face (20x20 cm2) or the back with visible light in the 407-420 nm range at an intensity of 90 mW/cm2 (CureLight Ltd.) for a total of 4 weeks. UV is totally cut off. In each treatment the patient was exposed to light for 8-15 minutes. After 8 treatments, 80% of the patients with mild to moderate papulo-pustular acne showed significant improvement at reducing the numbers of non- inflammatory, inflammatory and total facial lesions. Inflammatory lesion count decrease by a mean of 68%. No side effects to the treatment were noticed. In conclusion, full face or back illumination with the high intensity pure blue light we used exhibits a rapid significant decrease in acne lesions counts in 8 biweekly treatments.

  10. Measurement of the intensity of the beam in the abort gap at the Tevatron utilizing synchrotron light

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Thurman-Keup, R.; Lorman, E.; Meyer, T.

    2005-05-01

    This paper discusses the implementation of abort gap beam intensity monitoring at the Tevatron collider at Fermilab. There are two somewhat independent monitors which measure the intensity of the synchrotron light emitted by particles in the abort gaps. One system uses a gated Photomultiplier Tube (PMT) to measure the light intensity, and the other system uses a single lens telescope, gated image intensifier, and Charge Injection Device (CID) camera to image the beam.

  11. New findings regarding light intensity and its effects as a zeitgeber in the Sprague-Dawley rat

    NASA Technical Reports Server (NTRS)

    Tischler, A. C.; Winget, C. M.; Holley, D. C.; Deroshia, C. W.; Gott, J.; Mele, G.; Callahan, P. X.

    1993-01-01

    In most mammals, the suprachiasmatic nucleus of the anterior hypothalamus has been implicated as the central driving mechanism of circadian rhythmicity. The photic input from the retina, via the retino-hypothalamic tract, and modulation from the pineal gland help regulate the clock. In this study, we investigated the effects of low light intensity on the circadian system of the Sprague-Dawley rat. A series of light intensity experiments were conducted to determine if a light level of 0.1 Lux will maintain entrained circadian rhythms of feeding, drinking, and locomotor activity.

  12. A validated model to predict microalgae growth in outdoor pond cultures subjected to fluctuating light intensities and water temperatures

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Huesemann, Michael H.; Crowe, Braden J.; Waller, Peter

    Here, a microalgae biomass growth model was developed for screening novel strains for their potential to exhibit high biomass productivities under nutrient-replete conditions in outdoor ponds subjected to fluctuating light intensities and water temperatures. Growth is modeled by first estimating the light attenuation by biomass according to a scatter-corrected Beer-Lambert Law, and then calculating the specific growth rate in discretized culture volume slices that receive declining light intensities due to attenuation. The model requires the following experimentally determined strain-specific input parameters: specific growth rate as a function of light intensity and temperature, biomass loss rate in the dark as amore » function of temperature and average light intensity during the preceding light period, and the scatter-corrected biomass light absorption coefficient. The model was successful in predicting the growth performance and biomass productivity of three different microalgae species (Chlorella sorokiniana, Nannochloropsis salina, and Picochlorum sp.) in raceway pond cultures (batch and semi-continuous) subjected to diurnal sunlight intensity and water temperature variations. Model predictions were moderately sensitive to minor deviations in input parameters. To increase the predictive power of this and other microalgae biomass growth models, a better understanding of the effects of mixing-induced rapid light dark cycles on photo-inhibition and short-term biomass losses due to dark respiration in the aphotic zone of the pond is needed.« less

  13. A validated model to predict microalgae growth in outdoor pond cultures subjected to fluctuating light intensities and water temperatures

    DOE PAGES

    Huesemann, Michael H.; Crowe, Braden J.; Waller, Peter; ...

    2015-12-11

    Here, a microalgae biomass growth model was developed for screening novel strains for their potential to exhibit high biomass productivities under nutrient-replete conditions in outdoor ponds subjected to fluctuating light intensities and water temperatures. Growth is modeled by first estimating the light attenuation by biomass according to a scatter-corrected Beer-Lambert Law, and then calculating the specific growth rate in discretized culture volume slices that receive declining light intensities due to attenuation. The model requires the following experimentally determined strain-specific input parameters: specific growth rate as a function of light intensity and temperature, biomass loss rate in the dark as amore » function of temperature and average light intensity during the preceding light period, and the scatter-corrected biomass light absorption coefficient. The model was successful in predicting the growth performance and biomass productivity of three different microalgae species (Chlorella sorokiniana, Nannochloropsis salina, and Picochlorum sp.) in raceway pond cultures (batch and semi-continuous) subjected to diurnal sunlight intensity and water temperature variations. Model predictions were moderately sensitive to minor deviations in input parameters. To increase the predictive power of this and other microalgae biomass growth models, a better understanding of the effects of mixing-induced rapid light dark cycles on photo-inhibition and short-term biomass losses due to dark respiration in the aphotic zone of the pond is needed.« less

  14. Correlated peak relative light intensity and peak current in triggered lightning subsequent return strokes

    NASA Technical Reports Server (NTRS)

    Idone, V. P.; Orville, R. E.

    1985-01-01

    The correlation between peak relative light intensity L(R) and stroke peak current I(R) is examined for 39 subsequent return strokes in two triggered lightning flashes. One flash contained 19 strokes and the other 20 strokes for which direct measurements were available of the return stroke peak current at ground. Peak currents ranged from 1.6 to 21 kA. The measurements of peak relative light intensity were obtained from photographic streak recordings using calibrated film and microsecond resolution. Correlations, significant at better than the 0.1 percent level, were found for several functional relationships. Although a relation between L(R) and I(R) is evident in these data, none of the analytical relations considered is clearly favored. The correlation between L(R) and the maximum rate of current rise is also examined, but less correlation than between L(R) and I(R) is found. In addition, the peak relative intensity near ground is evaluated for 22 dart leaders, and a mean ratio of peak dart leader to peak return stroke relative light intensity was found to be 0.1 with a range of 0.02-0.23. Using two different methods, the peak current near ground in these dart leaders is estimated to range from 0.1 to 6 kA.

  15. Is the zodiacal light intensity steady. [cloud surface brightness and polarization from OSO-5 data

    NASA Technical Reports Server (NTRS)

    Burnett, G. B.; Sparrow, J. G.; Ney, E. P.

    1974-01-01

    It is pointed out that conclusions reported by Sparrow and Ney (1972, 1973) could be confirmed in an investigation involving the refinement of OSO-5 data on zodiacal light. It had been found by Sparrow and Ney that the absolute value of both the surface brightness and polarization of the zodiacal cloud varied by less than 10% over the 4-yr period from January 1969 to January 1973.

  16. Reconstructing the Geomagnetic Field in West Africa: First Absolute Intensity Results from Burkina Faso

    NASA Astrophysics Data System (ADS)

    Kapper, Lisa; Donadini, Fabio; Serneels, Vincent; Tema, Evdokia; Goguitchaichvili, Avto; Julio Morales, Juan

    2017-03-01

    We present absolute geomagnetic intensities from iron smelting furnaces discovered at the metallurgical site of Korsimoro, Burkina Faso. Up to now, archaeologists recognized four different types of furnaces based on different construction methods, which were related to four subsequent time periods. Additionally, radiocarbon ages obtained from charcoal confine the studied furnaces to ages ranging from 700-1700 AD, in good agreement with the archaeologically determined time periods for each type of furnace. Archaeointensity results reveal three main groups of Arai diagrams. The first two groups contain specimens with either linear Arai diagrams, or slightly curved diagrams or two phases of magnetization. The third group encompasses specimens with strong zigzag or curvature in their Arai diagrams. Specimens of the first two groups were accepted after applying selection criteria to guarantee the high quality of the results. Our data compared to palaeosecular variation curves show a similar decreasing trend between 900-1500 AD. However, they reveal larger amplitudes at around 800 AD and 1650 AD than the reference curves and geomagnetic field models. Furthermore, they agree well with archaeomagnetic data from Mali and Senegal around 800 AD and with volcanic data around 1700 AD.

  17. Reconstructing the Geomagnetic Field in West Africa: First Absolute Intensity Results from Burkina Faso

    PubMed Central

    Kapper, Lisa; Donadini, Fabio; Serneels, Vincent; Tema, Evdokia; Goguitchaichvili, Avto; Julio Morales, Juan

    2017-01-01

    We present absolute geomagnetic intensities from iron smelting furnaces discovered at the metallurgical site of Korsimoro, Burkina Faso. Up to now, archaeologists recognized four different types of furnaces based on different construction methods, which were related to four subsequent time periods. Additionally, radiocarbon ages obtained from charcoal confine the studied furnaces to ages ranging from 700–1700 AD, in good agreement with the archaeologically determined time periods for each type of furnace. Archaeointensity results reveal three main groups of Arai diagrams. The first two groups contain specimens with either linear Arai diagrams, or slightly curved diagrams or two phases of magnetization. The third group encompasses specimens with strong zigzag or curvature in their Arai diagrams. Specimens of the first two groups were accepted after applying selection criteria to guarantee the high quality of the results. Our data compared to palaeosecular variation curves show a similar decreasing trend between 900–1500 AD. However, they reveal larger amplitudes at around 800 AD and 1650 AD than the reference curves and geomagnetic field models. Furthermore, they agree well with archaeomagnetic data from Mali and Senegal around 800 AD and with volcanic data around 1700 AD. PMID:28350006

  18. Antioxidant capacity reduced in scallions grown under elevated CO 2 independent of assayed light intensity

    NASA Astrophysics Data System (ADS)

    Levine, Lanfang H.; Paré, Paul W.

    2009-10-01

    Long-duration manned space missions mandate the development of a sustainable life support system and effective countermeasures against damaging space radiation. To mitigate the risk of inevitable exposure to space radiation, cultivation of fresh fruits and vegetables rich in antioxidants is an attractive alternative to pharmacological agents. However it has yet to be established whether antioxidant properties of crops can be preserved or enhanced in a space environment where environmental conditions differ from that which plants have acclimated to on earth. Scallion ( Allium fistulosum) rich in antioxidant vitamins C and A, and flavonoids was used as a model plant to study the impact of a range of CO 2 concentrations and light intensities that are likely encountered in a space habitat on food quality traits. Scallions were hydroponically grown in controlled environmental chambers under a combination of 3 CO 2 concentrations of 400, 1200 and 4000 μmol mol -1 and 3 light intensity levels of 150, 300, 450 μmol m -2 s -1. Total antioxidant activity (TAA) of scallion extracts was determined using a radical cation scavenging assay. Both elevated CO 2 and increasing light intensity enhanced biomass accumulation, but effects on TAA (based on dry weight) differed. TAA was reduced for plants grown under elevated CO 2, but remained unchanged with increases in light intensity. Elevated CO 2 stimulated greater biomass production than antioxidants, while an increase in photosynthetic photo flux promoted the synthesis of antioxidant compounds at a rate similar to that of biomass. Consequently light is a more effective stimulus than CO 2 for antioxidant production.

  19. Dependence of anti-Stokes/Stokes intensity ratios on substrate optical properties for Brillouin light scattering from ultrathin iron films

    NASA Astrophysics Data System (ADS)

    Cochran, J. F.; From, M.; Heinrich, B.

    1998-06-01

    Brillouin light scattering experiments have been used to investigate the intensity of 5145 Å laser light backscattered from spin waves in 20 monolayer thick Fe(001) films. The experiments have shown that the ratio of frequency upshifted light intensity to frequency downshifted light intensity depends upon the material of the substrate used to support the iron films. For a fixed magnetic field and for a fixed angle of incidence of the laser light this intensity ratio is much larger for an iron film deposited on a sulphur passivated GaAs(001) substrate than for an iron film deposited on a Ag(001) substrate. The data have been compared with a calculation that takes into account multiple scattering of the optical waves in the iron film and in a protective gold overlayer. The observations are in qualitative agreement with the theory, except for angles of incidence greater than 60°.

  20. Synchronous Crepuscular Flight of Female Asian Gypsy Moths: Relationships of Light Intensity and Ambient and Body Temperatures

    Treesearch

    Ralph E. Charlton; Ring T. Carde; William E. Wallner; William E. Wallner

    1999-01-01

    Female gypsy moths (Lymantria dispar) of Asian heritage studied in central Siberia and Germany exhibit a highly synchronous flight at dusk, after light intensity falls to about 2 lux. This critical light intensity sets the timing of flight behaviors independent of ambient temperature. Flight follows several minutes of preflight wing fanning during which females in...

  1. Effects of plant size, temperature, and light intensity on flowering of Phalaenopsis hybrids in Mediterranean greenhouses.

    PubMed

    Paradiso, Roberta; De Pascale, Stefania

    2014-01-01

    Mediterranean greenhouses for cultivation of Phalaenopsis orchids reproduce the warm, humid, and shaded environment of tropical underbrush. Heating represents the highest production cost, due to the high thermal requirements and the long unproductive phase of juvenility, in which plants attain the critical size for flowering. Our researches aimed to investigate the effect of plant size, temperature, and light intensity, during the phase of flower induction, on flowering of modern genotypes selected for Mediterranean greenhouses. Three experiments were carried out to compare (i) plant size: reduced size versus size considered optimal for flowering (hybrids "Sogo Yukidian," "Chain Xen Diamond," and "Pinlong"); (ii) temperature: moderate reduction of temperature versus standard thermal regime (hybrid "Premium"); (iii) light intensity: supplemental lighting versus reference light intensity (hybrid "Premium"). The premature exposure of plants to the inductive treatment delayed the beginning of flowering and reduced the flower stem quality, in all the tested hybrids. In "Premium," the lower temperature did not affect flowering earliness and commercial quality of flower stems compared to the standard regime, whereas it promoted stem branching. In the same hybrid, supplemental lighting anticipated flowering and promoted the emission of the second stem and the stem branching, compared to the reference light regime.

  2. The ultrastructure of rabbit sclera after scleral crosslinking with riboflavin and blue light of different intensities.

    PubMed

    Karl, Anett; Makarov, Felix N; Koch, Christian; Körber, Nicole; Schuldt, Carsten; Krüger, Martin; Reichenbach, Andreas; Wiedemann, Peter; Bringmann, Andreas; Iseli, Hans Peter; Francke, Mike

    2016-08-01

    We aimed to determine the ultrastructural changes of collagen fibrils and cells in the rabbit sclera after scleral crosslinking using riboflavin and blue light of different intensities. Scleral crosslinking is known to increase scleral stiffness and may inhibit the axial elongation of progressive myopic eyes. The equatorial parts of the sclera of one eye of six adult albino rabbits were treated with topical riboflavin solution (0.5 %) followed by irradiation with blue light (200, 400, 650 mW/cm(2)) for 20 min. After 3 weeks, the ultrastructure of scleral cells and the abundance of small- (10-100 nm) and large-diameter (>100 nm) collagen fibrils in fibril bundles of different scleral layers were examined with electron microscopy. In the scleral stroma of control eyes, the thickness of collagen fibrils showed a bimodal distribution. The abundance of small-diameter collagen fibrils decreased from the inner towards the outer sclera, while the amount of large-diameter fibrils and the scleral collagen content did not differ between different stroma layers. Treatment with riboflavin and blue light at 200 mW/cm(2) did not induce ultrastructural changes of cells and collagen fibrils in the scleral stroma. Treatment with blue light of higher intensities induced scleral cell activation in a scleral layer-dependent manner. In addition, outer scleral layers contained phagocytes that engulfed collagen fibrils and erythrocytes. Blue light of the highest intensity induced a reduction of the scleral collagen content, a decreased abundance of large-diameter collagen fibrils, and an increased amount of small-diameter fibrils in the whole scleral stroma. The data indicate that in rabbits, scleral crosslinking with riboflavin and blue light of 200 mW/cm(2) for 20 min is relatively safe and does not induce ultrastructural alterations of scleral cells and of the collagen composition of the scleral stroma. Irradiation with blue light of intensities between 200 and 400 mW/cm(2

  3. Low light intensity and nitrogen starvation modulate the chlorophyll content of Scenedesmus dimorphus.

    PubMed

    Ferreira, V S; Pinto, R F; Sant'Anna, C

    2016-03-01

    Chlorophyll is a photosynthetic pigment found in plants and algal organisms and is a bioproduct with human health benefits and a great potential for use in the food industry. The chlorophyll content in microalgae strains varies in response to environmental factors. In this work, we assessed the effect of nitrogen depletion and low light intensity on the chlorophyll content of the Scenedesmus dimorphus microalga. The growth of S. dimorphus under low light intensity led to a reduction in cell growth and volume as well as increased cellular chlorophyll content. Nitrogen starvation led to a reduction in cell growth and the chlorophyll content, changes in the yield and productivity of chlorophylls a and b. Transmission electron microscopy was used to investigate the ultrastructural changes in the S. dimorphus exposed to nitrogen and light deficiency. In contrast to nitrogen depletion, low light availability was an effective mean for increasing the total chlorophyll content of green microalga S. dimorphus. The findings acquired in this work are of great biotechnological importance to extend knowledge of choosing the right culture condition to stimulate the effectiveness of microalgae strains for chlorophyll production purposes. © 2015 The Society for Applied Microbiology.

  4. Thresholds and noise limitations of colour vision in dim light.

    PubMed

    Kelber, Almut; Yovanovich, Carola; Olsson, Peter

    2017-04-05

    Colour discrimination is based on opponent photoreceptor interactions, and limited by receptor noise. In dim light, photon shot noise impairs colour vision, and in vertebrates, the absolute threshold of colour vision is set by dark noise in cones. Nocturnal insects (e.g. moths and nocturnal bees) and vertebrates lacking rods (geckos) have adaptations to reduce receptor noise and use chromatic vision even in very dim light. In contrast, vertebrates with duplex retinae use colour-blind rod vision when noisy cone signals become unreliable, and their transition from cone- to rod-based vision is marked by the Purkinje shift. Rod-cone interactions have not been shown to improve colour vision in dim light, but may contribute to colour vision in mesopic light intensities. Frogs and toads that have two types of rods use opponent signals from these rods to control phototaxis even at their visual threshold. However, for tasks such as prey or mate choice, their colour discrimination abilities fail at brighter light intensities, similar to other vertebrates, probably limited by the dark noise in cones.This article is part of the themed issue 'Vision in dim light'. © 2017 The Author(s).

  5. The role of low light intensity: A step towards understanding the connection between light, optic/lens and photovoltaic behavior for Sb2S3 thin-film solar cells

    NASA Astrophysics Data System (ADS)

    Lojpur, Vesna; Mitrić, Miodrag; Validžić, Ivana Lj

    2018-05-01

    We report here an optic/lens system that we used so far, for cooling the surface of solar cells, the reduction of light intensity and the change of light distribution that reaches the surface of the solar cell. The objective was to improve photovoltaic characteristics under very low light illumination, as well as to understand the connection between light, optic/lens and photovoltaic behavior for Sb2S3 thin-film solar cells. It was found that for all so far designed thin-film solar cells made and based on the synthesized Sb2S3, optics/lens system causes an increase in open circuit voltage (VOC) and short circuit current (ISC) and thus the efficiencies of made solar devices. Values of energy gaps for the thin-films made devices were in the range from 1.4 to 2 eV. Improvements of the photovoltaic response of the designed devices are found to be better at the lower light intensity (5% sun), than at higher intensities of light. For the same intensity of light used optic/lens improves the efficiency of the devices, by changing the light distribution. Other processes that are related to the optics/lens system, leading to an increase in ISC and VOC and consequently to an increase in efficiencies of the designed devices, are investigated.

  6. Interactions between light intensity and phosphorus nutrition affect the phosphate-mining capacity of white lupin (Lupinus albus L.)

    PubMed Central

    Cheng, Lingyun; Tang, Xiaoyan; Vance, Carroll P.; White, Philip J.; Zhang, Fusuo; Shen, Jianbo

    2014-01-01

    Light intensity affects photosynthetic carbon (C) fixation and the supply of carbon to roots. To evaluate interactions between carbon supply and phosphorus (P) supply, effects of light intensity on sucrose accumulation, root growth, cluster root formation, carboxylate exudation, and P uptake capacity were studied in white lupin (Lupinus albus L.) grown hydroponically with either 200 µmol m–2 s–1 or 600 µmol m–2 s–1 light and a sufficient (50 µM P) or deficient (1 µM P) P supply. Plant biomass and root:shoot ratio increased with increasing light intensity, particularly when plants were supplied with sufficient P. Both low P supply and increasing light intensity increased the production of cluster roots and citrate exudation. Transcripts of a phosphoenol pyruvate carboxylase gene (LaPEPC3) in cluster roots (which is related to the exudation of citrate), transcripts of a phosphate transporter gene (LaPT1), and P uptake all increased with increasing light intensity, under both P-sufficient and P-deficient conditions. Across all four experimental treatments, increased cluster root formation and carboxylate exudation were associated with lower P concentration in the shoot and greater sucrose concentration in the roots. It is suggested that C in excess of shoot growth capabilities is translocated to the roots as sucrose, which serves as both a nutritional signal and a C-substrate for carboxylate exudation and cluster root formation. PMID:24723402

  7. Interactions between light intensity and phosphorus nutrition affect the phosphate-mining capacity of white lupin (Lupinus albus L.).

    PubMed

    Cheng, Lingyun; Tang, Xiaoyan; Vance, Carroll P; White, Philip J; Zhang, Fusuo; Shen, Jianbo

    2014-07-01

    Light intensity affects photosynthetic carbon (C) fixation and the supply of carbon to roots. To evaluate interactions between carbon supply and phosphorus (P) supply, effects of light intensity on sucrose accumulation, root growth, cluster root formation, carboxylate exudation, and P uptake capacity were studied in white lupin (Lupinus albus L.) grown hydroponically with either 200 µmol m(-2) s(-1) or 600 µmol m(-2) s(-1) light and a sufficient (50 µM P) or deficient (1 µM P) P supply. Plant biomass and root:shoot ratio increased with increasing light intensity, particularly when plants were supplied with sufficient P. Both low P supply and increasing light intensity increased the production of cluster roots and citrate exudation. Transcripts of a phosphoenol pyruvate carboxylase gene (LaPEPC3) in cluster roots (which is related to the exudation of citrate), transcripts of a phosphate transporter gene (LaPT1), and P uptake all increased with increasing light intensity, under both P-sufficient and P-deficient conditions. Across all four experimental treatments, increased cluster root formation and carboxylate exudation were associated with lower P concentration in the shoot and greater sucrose concentration in the roots. It is suggested that C in excess of shoot growth capabilities is translocated to the roots as sucrose, which serves as both a nutritional signal and a C-substrate for carboxylate exudation and cluster root formation. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  8. Absolute band intensities in the nu19/nu23 (530 cm(-1)) and nu7 (777 cm(-1)) bands of acetone ((CH3)2CO) from 232 to 295 K

    NASA Technical Reports Server (NTRS)

    Wang, W. F.; Stevenson, A.; Reuter, D. C.; Sirota, J. M.

    2000-01-01

    Absolute band intensities of acetone ((CH3)2CO) in the nu19/nu23 and nu7 band systems near 530 and 777 cm(-1), respectively, were measured at temperatures of 232, 262 and 295 K, using a Fourier transform infrared (FTIR) spectrometer. No evident temperature dependence for the band intensities was observed. The dipole moments and the fundamental band intensities were derived in the harmonic oscillator approximation. The results are useful for the spectroscopic retrieval of acetone concentrations in the upper atmosphere.

  9. Light Intensity and Carbon Dioxide Availability Impact Antioxidant Activity in Green Onions (Allium fistulosumm L)

    NASA Astrophysics Data System (ADS)

    Levine, Lanfang; Bisbee, Patricia; Pare, Paul

    The prospect of long-duration manned space missions poses many challenges, including the development of a sustainable life support system and effective methods of space-radiation protection. To mitigate the risk of increased space-radiation, functional foods rich in antioxidant properties such as green onions are of particular interest. However it has yet to be established whether antioxidant properties can be preserved or enhanced in space environment where carbon dioxide, lighting intensity, gravity and pressure differ from which plants have acclimated to on earth. In this study, green onions (Allium fistulosumm L. cultivar Kinka) rich in antioxidant flavonoids are used as a model system to investigate variations in antioxidant capacity with plants grown under varying light intensities and CO2 concentrations. The antioxidant potential is determined using both radical cation scavenging and oxygen radical absorbance assays. For all light intensities assayed, antioxidant potential in water extract of green onions per gram biomass declined with CO2 increases up to 1200 ppm, and then leveled off with further CO2 increase to 4000 ppm. This inverse carbon dioxide versus antioxidant activity correlation suggests lower accumulation rates for water soluble antioxidant compounds compared to total biomass under increasing CO2 concentrations. The effect of increasing atmospheric CO2 concentration on antioxidant activity of ethanol extracts were light intensity dependent. The implications of these findings are discussed in the context of traditional plant antioxidants including vitamin C and the major onion flavonoid quercetin.

  10. Auxin-to-Gibberellin Ratio as a Signal for Light Intensity and Quality in Regulating Soybean Growth and Matter Partitioning

    PubMed Central

    Yang, Feng; Fan, Yuanfang; Wu, Xiaoling; Cheng, Yajiao; Liu, Qinlin; Feng, Lingyang; Chen, Junxu; Wang, Zhonglin; Wang, Xiaochun; Yong, Taiwen; Liu, Weiguo; Liu, Jiang; Du, Junbo; Shu, Kai; Yang, Wenyu

    2018-01-01

    The intensity and quality (red to far-red (R/Fr) ratio) of light directly affect growth of plant under shading. Gibberellins (GAs) and auxin [indole-3-acetic acid (IAA)] play important roles in mediating the shading adaptive responses of plants. Thus, the intensity and quality of the uncoupling light from shading were assessed to identify the influence of each component on the morphology and matter distribution of the leaf, stem, and petiole. This assessment was based on the changes in endogenous Gibberellin 1 (GA1) and IAA levels. Soybean plants were grown in a growth chamber with four treatments [normal (N), N+Fr, low (L), and L+Fr light]. Results revealed that the reductions in photosynthetically active radiation (PAR) and R/Fr ratio equally increased height and stem mass fractions (SMFs) of the soybean seedling. The light intensity significantly influenced the dry mass per unit area and mass fraction of soybean leaves, whereas the light quality regulated the petiole elongation and mass fraction. Low R/Fr ratio (high Fr light) increased the soybean biomass by improving the photosynthetic assimilation rate and quantum yield of photosystem II. In addition, the IAA and GA1 levels in the leaf, stem, and petiole did not reflect the growth response trends of each tissue toward light intensity and quality; however, trends of the IAA-to-GA1 content ratios were similar to those of the growth and matter allocation of each soybean tissue under different light environments. Therefore, the response of growth and matter allocation of soybean to light intensity and quality may be regulated by the IAA-to-GA1 content ratio in the tissues of the soybean plant. PMID:29441084

  11. The influence of light intensity and photoperiod on duckweed biomass and starch accumulation for bioethanol production.

    PubMed

    Yin, Yehu; Yu, Changjiang; Yu, Li; Zhao, Jinshan; Sun, Changjiang; Ma, Yubin; Zhou, Gongke

    2015-01-01

    Duckweed has been considered as a valuable feedstock for bioethanol production due to its high biomass and starch production. To investigate the effects of light conditions on duckweed biomass and starch production, Lemna aequinoctialis 6000 was cultivated at different photoperiods (12:12, 16:8 and 24:0h) and light intensities (20, 50, 80, 110, 200 and 400μmolm(-2)s(-1)). The results showed that the duckweed biomass and starch production was increased with increasing light intensity and photoperiod except at 200 and 400μmolm(-2)s(-1). Considering the light cost, 110μmolm(-2)s(-1) was optimum light condition for starch accumulation with the highest maximum growth rate, biomass and starch production of 8.90gm(-2)day(-1), 233.25gm(-2) and 98.70gm(-2), respectively. Moreover, the results suggested that high light induction was a promising method for duckweed starch accumulation. This study provides optimized light conditions for future industrial large-scale duckweed cultivation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Transcriptome profiling of anthocyanin-related genes reveals effects of light intensity on anthocyanin biosynthesis in red leaf lettuce.

    PubMed

    Zhang, Yanzhao; Xu, Shuzhen; Cheng, Yanwei; Peng, Zhengfeng; Han, Jianming

    2018-01-01

    Red leaf lettuce ( Lactuca sativa L.) is popular due to its high anthocyanin content, but poor leaf coloring often occurs under low light intensity. In order to reveal the mechanisms of anthocyanins affected by light intensity, we compared the transcriptome of L. sativa L. var. capitata under light intensities of 40 and 100 μmol m -2 s -1 . A total of 62,111 unigenes were de novo assembled with an N50 of 1,681 bp, and 48,435 unigenes were functionally annotated in public databases. A total of 3,899 differentially expressed genes (DEGs) were detected, of which 1,377 unigenes were up-regulated and 2,552 unigenes were down-regulated in the high light samples. By Kyoto Encyclopedia of Genes and Genomes enrichment analysis, the DEGs were significantly enriched in 14 pathways. Using gene annotation and phylogenetic analysis, we identified seven anthocyanin structural genes, including CHS , CHI , F3H , F3'H , DFR , ANS , and 3GT , and two anthocyanin transport genes, GST and MATE . In terms of anthocyanin regulatory genes, five MYBs and one bHLH gene were identified. An HY5 gene was discovered, which may respond to light-signaling and regulate anthocyanin structural genes. These genes showed a log2FC of 2.7-9.0 under high irradiance, and were validated using quantitative real-time-PCR. In conclusion, our results indicated transcriptome variance in red leaf lettuce under low and high light intensity, and observed a anthocyanin biosynthesis and regulation pattern. The data should further help to unravel the molecular mechanisms of anthocyanins influenced by light intensity.

  13. Low-intensity blue-enriched white light (750 lux) and standard bright light (10,000 lux) are equally effective in treating SAD. A randomized controlled study.

    PubMed

    Meesters, Ybe; Dekker, Vera; Schlangen, Luc J M; Bos, Elske H; Ruiter, Martine J

    2011-01-28

    Photoreceptor cells containing melanopsin play a role in the phase-shifting effects of short-wavelength light. In a previous study, we compared the standard light treatment (SLT) of SAD with treatment using short-wavelength blue-enriched white light (BLT). Both treatments used the same illuminance (10,000 lux) and were equally highly effective. It is still possible, however, that neither the newly-discovered photoreceptor cells, nor the biological clock play a major role in the therapeutic effects of light on SAD. Alternatively, these effects may at least be partly mediated by these receptor cells, which may have become saturated as a result of the high illuminances used in the therapy. This randomized controlled study compares the effects of low-intensity BLT to those of high-intensity SLT. In a 22-day design, 22 patients suffering from a major depression with a seasonal pattern (SAD) were given light treatment (10,000 lux) for two weeks on workdays. Subjects were randomly assigned to either of the two conditions, with gender and age evenly distributed over the groups. Light treatment either consisted of 30 minutes SLT (5000 °K) with the EnergyLight® (Philips, Consumer Lifestyle) with a vertical illuminance of 10,000 lux at eye position or BLT (17,000 °K) with a vertical illuminance of 750 lux using a prototype of the EnergyLight® which emitted a higher proportion of short-wavelengths. All participants completed questionnaires concerning mood, activation and sleep quality on a daily basis. Mood and energy levels were also assessed on a weekly basis by means of the SIGH-SAD and other assessment tools. On day 22, SIGH-SAD ratings were significantly lower than on day 1 (SLT 65.2% and BLT 76.4%). On the basis of all assessments no statistically significant differences were found between the two conditions. With sample size being small, conclusions can only be preliminary. Both treatment conditions were found to be highly effective. The therapeutic effects of low-intensity

  14. Fundamental study for scattering suppression in biological tissue using digital phase-conjugate light with intensity modulation

    NASA Astrophysics Data System (ADS)

    Toda, Sogo; Kato, Yuji; Kudo, Nobuki; Shimizu, Koichi

    2017-04-01

    For transillumination imaging of an animal body, we have attempted to suppress the scattering effect in a turbid medium. It is possible to restore the optical image before scattering using phase-conjugate light. We examined the effect of intensity information as well as the phase information for the restoration of the original light distribution. In an experimental analysis using animal tissue, the contributions of the phase- and the intensity-information to the image restoration through turbid medium were demonstrated.

  15. The Influence of Low Intensities of Light Pollution on Bat Communities in a Semi-Natural Context

    PubMed Central

    Lacoeuilhe, Aurelie; Machon, Nathalie; Julien, Jean-François; Le Bocq, Agathe; Kerbiriou, Christian

    2014-01-01

    Anthropogenic light pollution is an increasingly significant issue worldwide. Over the past century, the use of artificial lighting has increased in association with human activity. Artificial lights are suspected to have substantial effects on the ecology of many species, e.g., by producing discontinuities in the territories of nocturnal animals. We analyzed the potential influence of the intensity and type of artificial light on bat activity in a semi-natural landscape in France. We used a species approach, followed by a trait-based approach, to light sensitivity. We also investigated whether the effect of light could be related to foraging traits. We performed acoustic surveys at sites located along a gradient of light intensities to assess the activity of 15 species of bats. We identified 2 functional response groups of species: one group that was light-tolerant and one group that was light-intolerant. Among the species in the latter group that appear to be disadvantaged by lighting conditions, many are rare and threatened in Europe, whereas the species from the former group are better able to thrive in disturbed habitats such as lighted areas and may actually benefit from artificial lighting. Finally, several methods of controlling light pollution are suggested for the conservation of bat communities. Recommendations for light management and the creation of dim-light corridors are proposed; these strategies may play an important role in protecting against the impact of light pollution on nocturnal animals. PMID:25360638

  16. The influence of low intensities of light pollution on bat communities in a semi-natural context.

    PubMed

    Lacoeuilhe, Aurelie; Machon, Nathalie; Julien, Jean-François; Le Bocq, Agathe; Kerbiriou, Christian

    2014-01-01

    Anthropogenic light pollution is an increasingly significant issue worldwide. Over the past century, the use of artificial lighting has increased in association with human activity. Artificial lights are suspected to have substantial effects on the ecology of many species, e.g., by producing discontinuities in the territories of nocturnal animals. We analyzed the potential influence of the intensity and type of artificial light on bat activity in a semi-natural landscape in France. We used a species approach, followed by a trait-based approach, to light sensitivity. We also investigated whether the effect of light could be related to foraging traits. We performed acoustic surveys at sites located along a gradient of light intensities to assess the activity of 15 species of bats. We identified 2 functional response groups of species: one group that was light-tolerant and one group that was light-intolerant. Among the species in the latter group that appear to be disadvantaged by lighting conditions, many are rare and threatened in Europe, whereas the species from the former group are better able to thrive in disturbed habitats such as lighted areas and may actually benefit from artificial lighting. Finally, several methods of controlling light pollution are suggested for the conservation of bat communities. Recommendations for light management and the creation of dim-light corridors are proposed; these strategies may play an important role in protecting against the impact of light pollution on nocturnal animals.

  17. LED Lighting - Modification of Growth, Metabolism, Yield and Flour Composition in Wheat by Spectral Quality and Intensity.

    PubMed

    Monostori, István; Heilmann, Márk; Kocsy, Gábor; Rakszegi, Marianna; Ahres, Mohamed; Altenbach, Susan B; Szalai, Gabriella; Pál, Magda; Toldi, Dávid; Simon-Sarkadi, Livia; Harnos, Noémi; Galiba, Gábor; Darko, Éva

    2018-01-01

    The use of light-emitting diode (LED) technology for plant cultivation under controlled environmental conditions can result in significant reductions in energy consumption. However, there is still a lack of detailed information on the lighting conditions required for optimal growth of different plant species and the effects of light intensity and spectral composition on plant metabolism and nutritional quality. In the present study, wheat plants were grown under six regimens designed to compare the effects of LED and conventional fluorescent lights on growth and development, leaf photosynthesis, thiol and amino acid metabolism as well as grain yield and flour quality of wheat. Benefits of LED light sources over fluorescent lighting were manifested in both yield and quality of wheat. Elevated light intensities made possible with LEDs increased photosynthetic activity, the number of tillers, biomass and yield. At lower light intensities, blue, green and far-red light operated antagonistically during the stem elongation period. High photosynthetic activity was achieved when at least 50% of red light was applied during cultivation. A high proportion of blue light prolonged the juvenile phase, while the shortest flowering time was achieved when the blue to red ratio was around one. Blue and far-red light affected the glutathione- and proline-dependent redox environment in leaves. LEDs, especially in Blue, Pink and Red Low Light (RedLL) regimens improved flour quality by modifying starch and protein content, dough strength and extensibility as demonstrated by the ratios of high to low molecular weight glutenins, ratios of glutenins to gliadins and gluten spread values. These results clearly show that LEDs are efficient for experimental wheat cultivation, and make it possible to optimize the growth conditions and to manipulate metabolism, yield and quality through modification of light quality and quantity.

  18. Light intensity modulation by coccoliths of Emiliania huxleyi as a micro-photo-regulator.

    PubMed

    Mizukawa, Yuri; Miyashita, Yuito; Satoh, Manami; Shiraiwa, Yoshihiro; Iwasaka, Masakazu

    2015-09-01

    In this study, we present experimental evidence showing that coccoliths have light-scattering anisotropy that contributes to a possible control of solar light exposure in the ocean. Changing the angle between the incident light and an applied magnetic field causes differences in the light-scattering intensities of a suspension of coccoliths isolated from Emiliania huxleyi. The magnetic field effect is induced by the diamagnetic torque force directing the coccolith radial plane perpendicular to the applied magnetic fields at 400 to 500 mT. The developed technique reveals the light-scattering anisotropies in the 3-μm-diameter floating coccoliths by orienting themselves in response to the magnetic fields. The detached coccolith scatters radially the light incident to its radial plane. The experimental results on magnetically oriented coccoliths show that an individual coccolith has a specific direction of light scattering, although the possible physiological effect of the coccolith remains for further study, focusing on the light-scattering anisotropies of coccoliths on living cells.

  19. Light intensity modulation by coccoliths of Emiliania huxleyi as a micro-photo-regulator

    NASA Astrophysics Data System (ADS)

    Mizukawa, Yuri; Miyashita, Yuito; Satoh, Manami; Shiraiwa, Yoshihiro; Iwasaka, Masakazu

    2015-09-01

    In this study, we present experimental evidence showing that coccoliths have light-scattering anisotropy that contributes to a possible control of solar light exposure in the ocean. Changing the angle between the incident light and an applied magnetic field causes differences in the light-scattering intensities of a suspension of coccoliths isolated from Emiliania huxleyi. The magnetic field effect is induced by the diamagnetic torque force directing the coccolith radial plane perpendicular to the applied magnetic fields at 400 to 500 mT. The developed technique reveals the light-scattering anisotropies in the 3-μm-diameter floating coccoliths by orienting themselves in response to the magnetic fields. The detached coccolith scatters radially the light incident to its radial plane. The experimental results on magnetically oriented coccoliths show that an individual coccolith has a specific direction of light scattering, although the possible physiological effect of the coccolith remains for further study, focusing on the light-scattering anisotropies of coccoliths on living cells.

  20. Light intensity and temperature affect systemic spread of silencing signal in transient agroinfiltration studies.

    PubMed

    Patil, Basavaprabhu L; Fauquet, Claude M

    2015-06-01

    RNA silencing is a sequence-specific post-transcriptional gene inactivation mechanism that operates in diverse organisms and that can extend beyond its site of initiation, owing to the movement of the silencing signal, called non-autonomous gene silencing. Previous studies have shown that several factors manifest the movement of the silencing signal, such as the size (21 or 24 nucleotides) of the secondary small interfering RNA (siRNA) produced, the steady-state concentration of siRNAs and their cognate messenger RNA (mRNA) or a change in the sink-source status of plant parts affecting phloem translocation. Our study shows that both light intensity and temperature have a significant impact on the systemic movement of the silencing signal in transient agroinfiltration studies in Nicotiana benthamiana. At higher light intensities (≥ 450 μE/m(2)/s) and higher temperatures (≥ 30 °C), gene silencing was localized to leaf tissue that was infiltrated, without any systemic spread. Interestingly, in these light and temperature conditions (≥ 450 μE/m(2) /s and ≥ 30 °C), the N. benthamiana plants showed recovery from the viral symptoms. However, the reduced systemic silencing and reduced viral symptom severity at higher light intensities were caused by a change in the sink-source status of the plant, ultimately affecting the phloem translocation of small RNAs or the viral genome. In contrast, at lower light intensities (<300 μE/m(2)/s) with a constant temperature of 25 °C, there was strong systemic movement of the silencing signal in the N. benthamiana plants and reduced recovery from virus infections. The accumulation of gene-specific siRNAs was reduced at higher temperature as a result of a reduction in the accumulation of transcript on transient agroinfiltration of RNA interference (RNAi) constructs, mostly because of poor T-DNA transfer activity of Agrobacterium, possibly also accompanied by reduced phloem translocation. © 2014 BSPP AND JOHN WILEY & SONS

  1. High light intensity mediates a shift from allochthonous to autochthonous carbon use in phototrophic stream biofilms

    NASA Astrophysics Data System (ADS)

    Wagner, Karoline; Bengtsson, Mia M.; Findlay, Robert H.; Battin, Tom J.; Ulseth, Amber J.

    2017-07-01

    Changes in the riparian vegetation along stream channels, diurnal light availability, and longitudinal fluctuations in the local light regime in streams influence primary production and carbon (C) cycling in benthic stream biofilms. To investigate the influence of light availability on the uptake dynamics of autochthonous and allochthonous dissolved organic carbon (DOC) in benthic biofilms, we experimentally added 13C-labeled allochthonous DOC to biofilms grown under light intensities ranging from 5 to 152 μmol photons m-2 s-1. We calculated the net C flux, which showed that benthic biofilms released autochthonous DOC across the entire light gradient. Light availability and diurnal light patterns influenced C uptake by benthic biofilms. More allochthonous DOC was respired under low light availability and at night, whereas under high light availability and during the day mainly autochthonous C was respired by the benthic biofilm community. Furthermore, phenol oxidase activity (indicative of allochthonous DOC uptake) was more elevated under low light availability, whereas beta-glucosidase activity (indicative of autochthonous DOC use) increased with light intensity. Collectively, our results suggest that biofilms exposed to high light inputs preferentially used autochthonous DOC, whereas biofilms incubated at attenuated levels showed greater use of allochthonous DOC. This has implications for the spatial dynamics of DOC uptake in streams and speaks against the occurrence of priming effects in algal-dominated stream biofilms.

  2. Physiological characteristics, dry matter, and active component accumulation patterns of Changium smyrnioides in response to a light intensity gradient.

    PubMed

    Wang, Chang-Lin; Guo, Qiao-Sheng; Zhu, Zai-Biao; Cheng, Bo-Xing

    2017-12-01

    Changium smyrnioides Wolff (Apiaceae) is an endangered medicinal plant with numerous pharmacological uses. To investigate the effect of light intensity levels on the growth and accumulation of secondary metabolites of C. smyrnioides, cultivated seedlings were subjected to different relative light intensities via sun-shading. Changium smyrnioides seedlings were subjected to five irradiance treatments (100, 60.54, 44.84, 31.39, and 10.56% sunlight) in glasshouse for 9 months. Enzymatic and non-enzymatic antioxidants with spectrophotometric method, photosynthetic parameters with Li-6400XT, dry matter accumulation and active component contents in the root with spectrophotometric and HPLC method were analyzed. With an increase in relative light intensity levels, activities of enzymatic and non-enzymatic antioxidants, and malondialdehyde (MDA) contents were increased overall, while net photosynthetic rate (P n ) and dry matter accumulation patter first increased and then declined. The highest net photosynthetic rate (30.68 μmol/m 2 ·s) and dry root weight (5.07 g) were achieved under 60.54% sunlight. Lower relative light intensity levels stimulated the accumulation levels of bioactive compounds in the roots so that the highest contents of mannitol (1.35%) and choline (405.58 μg/g) were recorded under 31.39% sunlight, and the highest polysaccharide content (10.80%) were achieved under 44.84% sunlight. With a decrease in the relative light intensity levels, the water-soluble component content increased first and then decreased. The results revealed that 31.39-60.54% sunlight serve as appropriate relative light intensity conditions for cultivated C. smyrnioides.

  3. Light illumination intensity dependence of photovoltaic parameter in polymer solar cells with ammonium heptamolybdate as hole extraction layer.

    PubMed

    Liu, Zhiyong; Niu, Shengli; Wang, Ning

    2018-01-01

    A low-temperature, solution-processed molybdenum oxide (MoO X ) layer and a facile method for polymer solar cells (PSCs) is developed. The PSCs based on a MoO X layer as the hole extraction layer (HEL) is a significant advance for achieving higher photovoltaic performance, especially under weaker light illumination intensity. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) measurements show that the (NH 4 ) 6 Mo 7 O 24 molecule decomposes and forms the molybdenum oxide (MoO X ) molecule when undergoing thermal annealing treatment. In this study, PSCs with the MoO X layer as the HEL exhibited better photovoltaic performance, especially under weak light illumination intensity (from 100 to 10mWcm -2 ) compared to poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS)-based PSCs. Analysis of the current density-voltage (J-V) characteristics at various light intensities provides information on the different recombination mechanisms in the PSCs with a MoO X and PEDOT:PSS layer as the HEL. That the slopes of the open-circuit voltage (V OC ) versus light illumination intensity plots are close to 1 unity (kT/q) reveals that bimolecular recombination is the dominant and weaker monomolecular recombination mechanism in open-circuit conditions. That the slopes of the short-circuit current density (J SC ) versus light illumination intensity plots are close to 1 reveals that the effective charge carrier transport and collection mechanism of the MoO X /indium tin oxide (ITO) anode is the weaker bimolecular recombination in short-circuit conditions. Our results indicate that MoO X is an alternative candidate for high-performance PSCs, especially under weak light illumination intensity. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Device to color modulate a stationary light beam gives high intensity

    NASA Technical Reports Server (NTRS)

    Gantz, W. A.

    1966-01-01

    Signal controlled system color modulates a beam of light while also providing high intensity and a stationary beam, either collimated or focused. The color modulation acquired by the presented system can be compatible with any color film by employing color filters formed to provide a color wedge having a color distribution compatible with the films color sensitivity.

  5. Metabolic Reprogramming in Leaf Lettuce Grown Under Different Light Quality and Intensity Conditions Using Narrow-Band LEDs.

    PubMed

    Kitazaki, Kazuyoshi; Fukushima, Atsushi; Nakabayashi, Ryo; Okazaki, Yozo; Kobayashi, Makoto; Mori, Tetsuya; Nishizawa, Tomoko; Reyes-Chin-Wo, Sebastian; Michelmore, Richard W; Saito, Kazuki; Shoji, Kazuhiro; Kusano, Miyako

    2018-05-21

    Light-emitting diodes (LEDs) are an artificial light source used in closed-type plant factories and provide a promising solution for a year-round supply of green leafy vegetables, such as lettuce (Lactuca sativa L.). Obtaining high-quality seedlings using controlled irradiation from LEDs is critical, as the seedling health affects the growth and yield of leaf lettuce after transplantation. Because key molecular pathways underlying plant responses to a specific light quality and intensity remain poorly characterised, we used a multi-omics-based approach to evaluate the metabolic and transcriptional reprogramming of leaf lettuce seedlings grown under narrow-band LED lighting. Four types of monochromatic LEDs (one blue, two green and one red) and white fluorescent light (control) were used at low and high intensities (100 and 300 μmol·m -2 ·s -1 , respectively). Multi-platform mass spectrometry-based metabolomics and RNA-Seq were used to determine changes in the metabolome and transcriptome of lettuce plants in response to different light qualities and intensities. Metabolic pathway analysis revealed distinct regulatory mechanisms involved in flavonoid and phenylpropanoid biosynthetic pathways under blue and green wavelengths. Taken together, these data suggest that the energy transmitted by green light is effective in creating a balance between biomass production and the production of secondary metabolites involved in plant defence.

  6. Pigment variations in Emiliania huxleyi (CCMP370) as a response to changes in light intensity or quality.

    PubMed

    Garrido, José L; Brunet, Christophe; Rodríguez, Francisco

    2016-12-01

    Many studies on photoacclimation examine the pigment responses to changes in light intensity, but variations in light climate in the aquatic environment are also related to changes in spectral composition. We have employed a high-performance liquid chromatography method with improved resolution towards chlorophyll c and fucoxanthin-related xanthophylls to examine the pigment composition of Emiliania huxleyi CCMP 370 under different light intensities and spectral qualities. To maintain its photosynthetic performance, E. huxleyi CCMP370 promotes drastic pigment changes that can be either the interconversion of pigments in pools with the same basic chromophoric structure (Fucoxanthin type or chlorophyll c type), or the ex novo synthesis (Diatoxanthin). These changes are linked either to variations in light quality (Fucoxanthin related xanthophylls) or in light intensity (chlorophyll c 3 /Monovinyl chlorophyll c 3 , Diadinoxanthin/Diatoxanthin, β,ɛ-carotene/ β,β-carotene). Fucoxanthin and 19'-hexanoyloxyfucoxanthin proportions were highly dependent on spectral conditions. Whereas Fucoxanthin dominated in green and red light, 19'-hexanoyloxyfucoxanthin prevailed under blue spectral conditions. Our results suggest that the huge pigment diversity enhanced the photoacclimative capacities of E. huxleyi to efficiently perform under changing light environments. The ubiquity and success in the global ocean as well as the capacity of E. huxleyi to form large surface blooms might be associated to the plasticity described here. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  7. Absolute Rovibrational Intensities for the Chi(sup 1)Sigma(sup +) v=3 <-- 0 Band of (12)C(16)O Obtained with Kitt Peak and BOMEM FTS Instruments

    NASA Technical Reports Server (NTRS)

    Chackerian, Charles, Jr.; Kshirsagar, R. J.; Giver, L. P.; Brown, L. R.; Condon, Estelle P. (Technical Monitor)

    1999-01-01

    This work was initiated to compare absolute line intensities retrieved with the Kitt Peak FTS (Fourier Transform Spectrometer) and Ames BOMEM FTS. Since thermal contaminations can be a problem using the BOMEM instrument if proper precautions are not taken it was thought that measurements done at 6300 per cm would more easily result in satisfactory intercomparisons. Very recent measurements of the CO 3 <-- 0 band fine intensities confirms results reported here that the intensities listed in HITRAN (High Resolution Molecular Absorption Database) for this band are on the order of six to seven percent too low. All of the infrared intensities in the current HITRAN tabulation are based on the electric dipole moment function reported fifteen years ago. The latter in turn was partly based on intensities for the 3 <-- 0 band reported thirty years ago. We have, therefore, redetermined the electric dipole moment function of ground electronic state CO.

  8. Thresholds and noise limitations of colour vision in dim light

    PubMed Central

    Yovanovich, Carola

    2017-01-01

    Colour discrimination is based on opponent photoreceptor interactions, and limited by receptor noise. In dim light, photon shot noise impairs colour vision, and in vertebrates, the absolute threshold of colour vision is set by dark noise in cones. Nocturnal insects (e.g. moths and nocturnal bees) and vertebrates lacking rods (geckos) have adaptations to reduce receptor noise and use chromatic vision even in very dim light. In contrast, vertebrates with duplex retinae use colour-blind rod vision when noisy cone signals become unreliable, and their transition from cone- to rod-based vision is marked by the Purkinje shift. Rod–cone interactions have not been shown to improve colour vision in dim light, but may contribute to colour vision in mesopic light intensities. Frogs and toads that have two types of rods use opponent signals from these rods to control phototaxis even at their visual threshold. However, for tasks such as prey or mate choice, their colour discrimination abilities fail at brighter light intensities, similar to other vertebrates, probably limited by the dark noise in cones. This article is part of the themed issue 'Vision in dim light’. PMID:28193810

  9. Monitoring of transient cavitation induced by ultrasound and intense pulsed light in presence of gold nanoparticles.

    PubMed

    Sazgarnia, Ameneh; Shanei, Ahmad; Shanei, Mohammad Mahdi

    2014-01-01

    One of the most important challenges in medical treatment is invention of a minimally invasive approach in order to induce lethal damages to cancer cells. Application of high intensity focused ultrasound can be beneficial to achieve this goal via the cavitation process. Existence of the particles and vapor in a liquid decreases the ultrasonic intensity threshold required for cavitation onset. In this study, synergism of intense pulsed light (IPL) and gold nanoparticles (GNPs) has been investigated as a means of providing nucleation sites for acoustic cavitation. Several approaches have been reported with the aim of cavitation monitoring. We conducted the experiments on the basis of sonochemiluminescence (SCL) and chemical dosimetric methods. The acoustic cavitation activity was investigated by determining the integrated SCL signal acquired over polyacrylamide gel phantoms containing luminol in the presence and absence of GNPs in the wavelength range of 400-500 nm using a spectrometer equipped with cooled charged coupled devices (CCD) during irradiation by different intensities of 1 MHz ultrasound and IPL pulses. In order to confirm these results, the terephthalic acid chemical dosimeter was utilized as well. The SCL signal recorded in the gel phantoms containing GNPs at different intensities of ultrasound in the presence of intense pulsed light was higher than the gel phantoms without GNPs. These results have been confirmed by the obtained data from the chemical dosimetry method. Acoustic cavitation in the presence of GNPs and intense pulsed light has been suggested as a new approach designed for decreasing threshold intensity of acoustic cavitation and improving targeted therapeutic effects. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Light intensity dependence of open-circuit voltage and short-circuit current of polymer/fullerene solar cells

    NASA Astrophysics Data System (ADS)

    Koster, L. Jan A.; Mihailetchi, Valentin D.; Ramaker, Robert; Xie, Hangxing; Blom, Paul W. M.

    2006-04-01

    The open-circuit voltage (Voc) of polymer/fullerene bulk heterojunction solar cells is investigated as a function of light intensity for different temperatures. The observed photogenerated current and V oc are at variance with classical p-n junctionbased models. The influence of light intensity and recombination strength on V oc is consistently explained by a model based on the notion that the quasi-Fermi levels are constant throughout the device, including both drift and diffusion of charge carriers. The light intensity dependence of the short-circuit current density (J sc) is also addressed. A typical feature of polymer/fullerene based solar cells is that Jsc does not scale exactly linearly with light intensity (I). Instead, a power law relationship is found given by Jsc~ Iα, where α ranges from 0.9 to 1. In a number of reports this deviation from unity is attributed to the occurrence of bimolecular recombination. We demonstrate that the dependence of the photocurrent in bulk heterojunction solar cells is governed by the build-up of space charge in the device. The occurrence of space-charge stems from the difference in charge carrier mobility of electrons and holes. In blends of poly(3-hexylthiophene) and 6,6- phenyl C61-butyric acid methyl ester this mobility difference can be tuned in between one and three orders of magnitude, depending on the annealing conditions. This allows us to experimentally verify the relation between space charge build-up and intensity dependence of Jsc. Model calculations confirm that bimolecular recombination leads only to a typical loss of 1% of all free charge carriers at Jsc for these devices. Therefore, bimolecular recombination plays only a minor role as compared to the effect of space charge in the intensity dependence of J sc.

  11. Effect of intense pulsed light on immature burn scars: A clinical study

    PubMed Central

    Sarkar, Arindam; Dewangan, Yatindra Kumar; Bain, Jayanta; Rakshit, Pritha; Dhruw, Krishnanand; Basu, Sandip Kanti; Saha, Jayanta Kumar; Majumdar, Bijay Kumar

    2014-01-01

    Introduction: As intense pulsed light (IPL) is widely used to treat cutaneous vascular malformations and also used as non-ablative skin rejunuvation to remodel the skin collagen. A study has been undertaken to gauze the effect of IPL on immature burn scars with regard to vascularity, pliability and height. Materials and Methods: This study was conducted between June 2013 and May 2014, among patients with immature burn scars that healed conservatively within 2 months. Photographic evidence of appearance of scars and grading and rating was done with Vancouver Scar Scale parameters. Ratings were done for both case and control scar after the completion of four IPL treatment sessions and were compared. Results: Out of the 19 cases, vascularity, pliability and height improved significantly (P < 0.05) in 13, 14 and 11 scars respectively following IPL treatment. Conclusions: Intense pulsed light was well-tolerated by patients, caused good improvement in terms of vascularity, pliability, and height of immature burn scar. PMID:25593424

  12. THE FAST DECLINING TYPE Ia SUPERNOVA 2003gs, AND EVIDENCE FOR A SIGNIFICANT DISPERSION IN NEAR-INFRARED ABSOLUTE MAGNITUDES OF FAST DECLINERS AT MAXIMUM LIGHT

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Krisciunas, Kevin; Marion, G. H.; Suntzeff, Nicholas B.

    2009-12-15

    We obtained optical photometry of SN 2003gs on 49 nights, from 2 to 494 days after T(B {sub max}). We also obtained near-IR photometry on 21 nights. SN 2003gs was the first fast declining Type Ia SN that has been well observed since SN 1999by. While it was subluminous in optical bands compared to more slowly declining Type Ia SNe, it was not subluminous at maximum light in the near-IR bands. There appears to be a bimodal distribution in the near-IR absolute magnitudes of Type Ia SNe at maximum light. Those that peak in the near-IR after T(B {sub max})more » are subluminous in the all bands. Those that peak in the near-IR prior to T(B {sub max}), such as SN 2003gs, have effectively the same near-IR absolute magnitudes at maximum light regardless of the decline rate {delta}m {sub 15}(B). Near-IR spectral evidence suggests that opacities in the outer layers of SN 2003gs are reduced much earlier than for normal Type Ia SNe. That may allow {gamma} rays that power the luminosity to escape more rapidly and accelerate the decline rate. This conclusion is consistent with the photometric behavior of SN 2003gs in the IR, which indicates a faster than normal decline from approximately normal peak brightness.« less

  13. Looking for light in the din: An examination of the circadian-disrupting properties of a medical intensive care unit.

    PubMed

    Danielson, Samantha J; Rappaport, Charles A; Loher, Michael K; Gehlbach, Brian K

    2018-06-01

    Critically ill patients exhibit profound disturbances of circadian rhythmicity, most commonly in the form of a phase delay. We investigated the specific zeitgeber properties of a medical intensive care unit to develop a model that explained these abnormalities. Prospective, observational study conducted during 2013-2014. Twenty-four-hour ambient light (lux, 672 hours) and sound pressure levels (dBA, 504 hours) were measured in patient rooms. Patients and families were surveyed regarding their perceptions of the environment. University-based adult medical intensive care unit. The timing and intensity of the ambient light-dark cycle and sound environment and the relationship of these measurements to patient/family perceptions. Twenty-four-hour light-dark cycles were extremely weak and phase delayed relative to the solar cycle. Morning light averaged 12.1 (4.8, 37.2) lux, when only 24.9% ± 10.9% of available light was utilised; yet patients and families did not identify low daytime light levels as problematic. Median noise levels were invariably excessive (nighttime 47.9 [45.0, 51.3] dBA) with minimal variation, consistent with the absence of a defined rest period. The intensive care unit functions as a near-constant routine protocol disconnected from solar time. Behavioural interventions to promote entrainment should be supported by objective measurements of light and sound. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Health Benefits of Light-Intensity Physical Activity: A Systematic Review of Accelerometer Data of the National Health and Nutrition Examination Survey (NHANES).

    PubMed

    Füzéki, Eszter; Engeroff, Tobias; Banzer, Winfried

    2017-09-01

    The health effects of light-intensity physical activity (PA) are not well known today. We conducted a systematic review to assess the association of accelerometer-measured light-intensity PA with modifiable health outcomes in adults and older adults. A systematic literature search up to March 2016 was performed in the PubMed, EMBASE, Web of Science and Google Scholar electronic databases, without language limitations, for studies of modifiable health outcomes in adults and older adults in the National Health and Nutrition Examination Survey accelerometer dataset. Overall, 37 cross-sectional studies and three longitudinal studies were included in the analysis, with considerable variation observed between the studies with regard to their operationalization of light-intensity PA. Light-intensity PA was found to be beneficially associated with obesity, markers of lipid and glucose metabolism, and mortality. Few data were available on musculoskeletal outcomes and results were mixed. Observational evidence that light-intensity PA can confer health benefits is accumulating. Currently inactive or insufficiently active people should be encouraged to engage in PA of any intensity. If longitudinal and intervention studies corroborate our findings, the revision of PA recommendations to include light-intensity activities, at least for currently inactive populations, might be warranted.

  15. Lighting, sleep and circadian rhythm: An intervention study in the intensive care unit.

    PubMed

    Engwall, Marie; Fridh, Isabell; Johansson, Lotta; Bergbom, Ingegerd; Lindahl, Berit

    2015-12-01

    Patients in an intensive care unit (ICU) may risk disruption of their circadian rhythm. In an intervention research project a cycled lighting system was set up in an ICU room to support patients' circadian rhythm. Part I aimed to compare experiences of the lighting environment in two rooms with different lighting environments by lighting experiences questionnaire. The results indicated differences in advantage for the patients in the intervention room (n=48), in perception of daytime brightness (p=0.004). In nighttime, greater lighting variation (p=0.005) was found in the ordinary room (n=52). Part II aimed to describe experiences of lighting in the room equipped with the cycled lighting environment. Patients (n=19) were interviewed and the results were presented in categories: "A dynamic lighting environment", "Impact of lighting on patients' sleep", "The impact of lighting/lights on circadian rhythm" and "The lighting calms". Most had experiences from sleep disorders and half had nightmares/sights and circadian rhythm disruption. Nearly all were pleased with the cycled lighting environment, which together with daylight supported their circadian rhythm. In night's actual lighting levels helped patients and staff to connect which engendered feelings of calm. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Flight control and landing precision in the nocturnal bee Megalopta is robust to large changes in light intensity.

    PubMed

    Baird, Emily; Fernandez, Diana C; Wcislo, William T; Warrant, Eric J

    2015-01-01

    Like their diurnal relatives, Megalopta genalis use visual information to control flight. Unlike their diurnal relatives, however, they do this at extremely low light intensities. Although Megalopta has developed optical specializations to increase visual sensitivity, theoretical studies suggest that this enhanced sensitivity does not enable them to capture enough light to use visual information to reliably control flight in the rainforest at night. It has been proposed that Megalopta gain extra sensitivity by summing visual information over time. While enhancing the reliability of vision, this strategy would decrease the accuracy with which they can detect image motion-a crucial cue for flight control. Here, we test this temporal summation hypothesis by investigating how Megalopta's flight control and landing precision is affected by light intensity and compare our findings with the results of similar experiments performed on the diurnal bumblebee Bombus terrestris, to explore the extent to which Megalopta's adaptations to dim light affect their precision. We find that, unlike Bombus, light intensity does not affect flight and landing precision in Megalopta. Overall, we find little evidence that Megalopta uses a temporal summation strategy in dim light, while we find strong support for the use of this strategy in Bombus.

  17. Removal of the blue component of light significantly decreases retinal damage after high intensity exposure.

    PubMed

    Vicente-Tejedor, Javier; Marchena, Miguel; Ramírez, Laura; García-Ayuso, Diego; Gómez-Vicente, Violeta; Sánchez-Ramos, Celia; de la Villa, Pedro; Germain, Francisco

    2018-01-01

    Light causes damage to the retina (phototoxicity) and decreases photoreceptor responses to light. The most harmful component of visible light is the blue wavelength (400-500 nm). Different filters have been tested, but so far all of them allow passing a lot of this wavelength (70%). The aim of this work has been to prove that a filter that removes 94% of the blue component may protect the function and morphology of the retina significantly. Three experimental groups were designed. The first group was unexposed to light, the second one was exposed and the third one was exposed and protected by a blue-blocking filter. Light damage was induced in young albino mice (p30) by exposing them to white light of high intensity (5,000 lux) continuously for 7 days. Short wavelength light filters were used for light protection. The blue component was removed (94%) from the light source by our filter. Electroretinographical recordings were performed before and after light damage. Changes in retinal structure were studied using immunohistochemistry, and TUNEL labeling. Also, cells in the outer nuclear layer were counted and compared among the three different groups. Functional visual responses were significantly more conserved in protected animals (with the blue-blocking filter) than in unprotected animals. Also, retinal structure was better kept and photoreceptor survival was greater in protected animals, these differences were significant in central areas of the retina. Still, functional and morphological responses were significantly lower in protected than in unexposed groups. In conclusion, this blue-blocking filter decreases significantly photoreceptor damage after exposure to high intensity light. Actually, our eyes are exposed for a very long time to high levels of blue light (screens, artificial light LED, neons…). The potential damage caused by blue light can be palliated.

  18. Influence of environmental temperature and light intensity on growth performance and blood physiological parameters of broilers grown to heavy weight

    USDA-ARS?s Scientific Manuscript database

    In a study of temperature and light intensity, 9 treatments consisted of 3 levels (Low=15.6, Moderate=21.1, High=26.7 °C) of temperatures and 3 levels (0.5, 3.0, 20 lx) of light intensities from d 8 to 56 d of age. Across all light levels at d 56, broilers subjected to high temperature significantly...

  19. Associations of Low- and High-Intensity Light Activity with Cardiometabolic Biomarkers.

    PubMed

    Howard, Bethany; Winkler, Elisabeth A H; Sethi, Parneet; Carson, Valerie; Ridgers, Nicola D; Salmon, J O; Healy, Genevieve N; Owen, Neville; Dunstan, David W

    2015-10-01

    Light-intensity physical activity (LIPA) accounts for much of adults' waking hours (≈40%) and substantially contributes to overall daily energy expenditure. Encompassing activity behaviors of low intensity (standing with little movement) to those of higher intensity (slow walking), LIPA is ubiquitous, yet little is known about how associations with health may vary depending on its intensity. We examined the associations of objectively assessed LIPA (categorized as either low LIPA [LLPA] or high LIPA [HLPA]) and moderate- to vigorous-intensity activity with cardiometabolic risk biomarkers. Cardiometabolic biomarkers were measured in 4614 US adults (47 ± 17 yr) who participated in the 2003-2004 and 2005-2006 National Health and Nutrition Examination Survey cycles. Multiple linear regression analyses examined the associations of three accelerometer-derived physical activity (SD increment per day) intensity categories (LLPA, 100-761 counts per minute; HLPA, 762-1951 counts per minute; moderate-intensity physical activity [MPA], 1952-5724 counts per minute; vigorous-intensity physical activity [VPA], ≥5725 counts per minute) with cardiometabolic biomarkers, adjusting for potential sociodemographic, behavioral, and medical confounders. All intensities of physical activity were beneficially associated with waist circumference, C-reactive protein, triglycerides, fasting insulin, β-cell function, and insulin sensitivity (P < 0.05); only some activity intensities showed significant associations with systolic blood pressure (LLPA), body mass index, HDL cholesterol, fasting glucose, and 2-h plasma glucose (HLPA, MPA, and VPA). Generally, effect size increased with intensity of physical activity. Overall, further adjustment for waist circumference attenuated associations with MPA and VPA to a greater extent than associations with LLPA and HLPA. The cross-sectional findings provide novel evidence for the potential benefits of increasing both LLPA and HLPA. They further

  20. Lyman alpha SMM/UVSP absolute calibration and geocoronal correction

    NASA Technical Reports Server (NTRS)

    Fontenla, Juan M.; Reichmann, Edwin J.

    1987-01-01

    Lyman alpha observations from the Ultraviolet Spectrometer Polarimeter (UVSP) instrument of the Solar Maximum Mission (SMM) spacecraft were analyzed and provide instrumental calibration details. Specific values of the instrument quantum efficiency, Lyman alpha absolute intensity, and correction for geocoronal absorption are presented.

  1. Morning bright light exposure has no influence on self-chosen exercise intensity and mood in overweight individuals - A randomized controlled trial.

    PubMed

    Knaier, Raphael; Klenk, Christopher; Königstein, Karsten; Hinrichs, Timo; Rossmeissl, Anja; Infanger, Denis; Cajochen, Christian; Schmidt-Trucksäss, Arno

    2018-04-01

    Overweight is a worldwide increasing public health issue. Physical exercise is a useful countermeasure. Overweight individuals choose rather low exercise intensities, but especially high exercise intensities lead to higher energy expenditure and show beneficial health effects compared to lower exercise intensities. However, especially in the morning higher exercise intensities are likely to be avoided due to higher subjective effort. Bright light exposure has shown to increase maximum performance. The aim of this study was to investigate if bright light exposure can also increase self-chosen exercise intensity. We hypothesized that morning bright light exposure increases self-chosen exercise intensity of subsequent exercise through increased mood and reduced sleepiness in overweight individuals. In this randomized controlled single-blind parallel group design, 26 overweight individuals (11 males, 15 females; age 25 ± 5.7 years; body mass index 28.9 ± 2.1 kg/m 2 ) underwent three measurement appointments. On the first appointment, subjects performed a cardiopulmonary exercise test to measure maximum oxygen uptake (VO2max). Two days later a 30-min exercise session with self-chosen exercise intensity was performed for familiarization. Then subjects were randomly allocated to bright light (~4400 lx) or a control light (~230 lx) condition. Three to seven days later, subjects were exposed to light for 30 min starting at 8:00 am, immediately followed by a 30-min exercise session with persisting light exposure. Multidimensional mood questionnaires were filled out before and after the light exposure and after the exercise session. The primary outcome was the mean power output during the exercise session and the secondary outcome the rating on the three domains (i.e. good-bad; awake-tired; calm-nervous) of the multidimensional mood questionnaire. Mean power output during the exercise session was 92 ± 19 W in bright light and 80 ± 37 W in control light

  2. Light intensity of curved laryngoscope blades in Philadelphia emergency departments.

    PubMed

    Levitan, Richard M; Kelly, John J; Kinkle, William C; Fasano, Charles

    2007-09-01

    Laryngoscopy and tracheal intubation requires laryngeal exposure and illumination. The objective of this study is to assess variation in laryngoscope lights across different emergency departments (EDs). A convenience sample of 3 Mac #4 blade and handle pairs in each of 17 Philadelphia area EDs was tested with a digital light meter to derive the median lux at the distal tip. For each blade tested, we characterized blade design (American, English, or German) and light type (fiber-illuminated versus conventional bulb-on-blade) and measured light-to-tip distance. A total of 50 blades and handle pairs were tested (one ED had only 2 Mac #4 blades). American designs were the most common (38/50), followed by English (6/50) and German (3/50) designs. Three blades had hybrid design features and acrylic light-conducting fibers. Median luminance varied from 11 lux to 5,627 lux. The glass fiber-illuminated blades (n=13) produced greater luminance (median 1,205 lux; interquartile range [IQR] 726 to 2,176 lux) than bulb-on-blade designs (median 689 lux; IQR 290 to 906 lux). German fiber-illuminated blades produced the highest luminance (median 1,937 lux; IQR 1,453 to 3,782 lux). English bulb-on-blade designs produced more luminance (median 915 lux; IQR 745 to 1270 lux) than American (median 689 lux; IQR 269 to 807 lux). German and English blades had shorter light-to-tip distances (median 51 mm and 47 mm, respectively) than American blades (65 mm). Curved laryngoscope blades in different EDs have marked variation in light intensity. The contribution of luminance to laryngoscopy performance warrants investigation.

  3. Using digital inpainting to estimate incident light intensity for the calculation of red blood cell oxygen saturation from microscopy images.

    PubMed

    Sové, Richard J; Drakos, Nicole E; Fraser, Graham M; Ellis, Christopher G

    2018-05-25

    Red blood cell oxygen saturation is an important indicator of oxygen supply to tissues in the body. Oxygen saturation can be measured by taking advantage of spectroscopic properties of hemoglobin. When this technique is applied to transmission microscopy, the calculation of saturation requires determination of incident light intensity at each pixel occupied by the red blood cell; this value is often approximated from a sequence of images as the maximum intensity over time. This method often fails when the red blood cells are moving too slowly, or if hematocrit is too large since there is not a large enough gap between the cells to accurately calculate the incident intensity value. A new method of approximating incident light intensity is proposed using digital inpainting. This novel approach estimates incident light intensity with an average percent error of approximately 3%, which exceeds the accuracy of the maximum intensity based method in most cases. The error in incident light intensity corresponds to a maximum error of approximately 2% saturation. Therefore, though this new method is computationally more demanding than the traditional technique, it can be used in cases where the maximum intensity-based method fails (e.g. stationary cells), or when higher accuracy is required. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  4. Influence of light intensity and spectral composition of artificial light at night on melatonin rhythm and mRNA expression of gonadotropins in roach Rutilus rutilus.

    PubMed

    Brüning, Anika; Hölker, Franz; Franke, Steffen; Kleiner, Wibke; Kloas, Werner

    2018-02-01

    In this study we investigated the influence of artificial light at night (ALAN) of different intensities (0, 1, 10, 100 lx) and different colours (blue, green, red) on the daily melatonin rhythm and mRNA expression of gonadotropins in roach Rutilus rutilus, a ubiquitous cyprinid, which occur in standing and moderately flowing freshwater habitats of central Europe. Melatonin concentrations were significantly lowered under nocturnal white light already at 1 lx. Low intensity blue, green and red ALAN lowered the melatonin levels significantly in comparison to a dark control. We conclude that ALAN can disturb melatonin rhythms in roach at very low intensities and at different wavelengths and thus light pollution in urban waters has the potential to impact biological rhythms in fish. However, mRNA expression of gonadotropins was not affected by ALAN during the period of the experiments. Thus, suspected implications of ALAN on reproduction of roach could not be substantiated.

  5. Determining absolute protein numbers by quantitative fluorescence microscopy.

    PubMed

    Verdaasdonk, Jolien Suzanne; Lawrimore, Josh; Bloom, Kerry

    2014-01-01

    Biological questions are increasingly being addressed using a wide range of quantitative analytical tools to examine protein complex composition. Knowledge of the absolute number of proteins present provides insights into organization, function, and maintenance and is used in mathematical modeling of complex cellular dynamics. In this chapter, we outline and describe three microscopy-based methods for determining absolute protein numbers--fluorescence correlation spectroscopy, stepwise photobleaching, and ratiometric comparison of fluorescence intensity to known standards. In addition, we discuss the various fluorescently labeled proteins that have been used as standards for both stepwise photobleaching and ratiometric comparison analysis. A detailed procedure for determining absolute protein number by ratiometric comparison is outlined in the second half of this chapter. Counting proteins by quantitative microscopy is a relatively simple yet very powerful analytical tool that will increase our understanding of protein complex composition. © 2014 Elsevier Inc. All rights reserved.

  6. LED Lighting – Modification of Growth, Metabolism, Yield and Flour Composition in Wheat by Spectral Quality and Intensity

    PubMed Central

    Monostori, István; Heilmann, Márk; Kocsy, Gábor; Rakszegi, Marianna; Ahres, Mohamed; Altenbach, Susan B.; Szalai, Gabriella; Pál, Magda; Toldi, Dávid; Simon-Sarkadi, Livia; Harnos, Noémi; Galiba, Gábor; Darko, Éva

    2018-01-01

    The use of light-emitting diode (LED) technology for plant cultivation under controlled environmental conditions can result in significant reductions in energy consumption. However, there is still a lack of detailed information on the lighting conditions required for optimal growth of different plant species and the effects of light intensity and spectral composition on plant metabolism and nutritional quality. In the present study, wheat plants were grown under six regimens designed to compare the effects of LED and conventional fluorescent lights on growth and development, leaf photosynthesis, thiol and amino acid metabolism as well as grain yield and flour quality of wheat. Benefits of LED light sources over fluorescent lighting were manifested in both yield and quality of wheat. Elevated light intensities made possible with LEDs increased photosynthetic activity, the number of tillers, biomass and yield. At lower light intensities, blue, green and far-red light operated antagonistically during the stem elongation period. High photosynthetic activity was achieved when at least 50% of red light was applied during cultivation. A high proportion of blue light prolonged the juvenile phase, while the shortest flowering time was achieved when the blue to red ratio was around one. Blue and far-red light affected the glutathione- and proline-dependent redox environment in leaves. LEDs, especially in Blue, Pink and Red Low Light (RedLL) regimens improved flour quality by modifying starch and protein content, dough strength and extensibility as demonstrated by the ratios of high to low molecular weight glutenins, ratios of glutenins to gliadins and gluten spread values. These results clearly show that LEDs are efficient for experimental wheat cultivation, and make it possible to optimize the growth conditions and to manipulate metabolism, yield and quality through modification of light quality and quantity. PMID:29780400

  7. Light intensity as major factor to maximize biomass and lipid productivity of Ettlia sp. in CO2-controlled photoautotrophic chemostat.

    PubMed

    Seo, Seong-Hyun; Ha, Ji-San; Yoo, Chan; Srivastava, Ankita; Ahn, Chi-Yong; Cho, Dae-Hyun; La, Hyun-Joon; Han, Myung-Soo; Oh, Hee-Mock

    2017-11-01

    The optimal culture conditions are critical factors for high microalgal biomass and lipid productivity. To optimize the photoautotrophic culture conditions, combination of the pH (regulated by CO 2 supply), dilution rate, and light intensity was systematically investigated for Ettlia sp. YC001 cultivation in a chemostat during 143days. The biomass productivity increased with the increase in dilution rate and light intensity, but decreased with increasing pH. The average lipid content was 19.8% and statistically non-variable among the tested conditions. The highest biomass and lipid productivities were 1.48gL -1 d -1 and 291.4mgL -1 d -1 with a pH of 6.5, dilution rate of 0.78d -1 , and light intensity of 1500μmolphotonsm -2 s -1 . With a sufficient supply of CO 2 and nutrients, the light intensity was the main determinant of the photosynthetic rate. Therefore, the surface-to-volume ratio of a photobioreactor should enable efficient light distribution to enhance microalgal growth. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Absolute calibration of ultraviolet filter photometry

    NASA Technical Reports Server (NTRS)

    Bless, R. C.; Fairchild, T.; Code, A. D.

    1972-01-01

    The essential features of the calibration procedure can be divided into three parts. First, the shape of the bandpass of each photometer was determined by measuring the transmissions of the individual optical components and also by measuring the response of the photometer as a whole. Secondly, each photometer was placed in the essentially-collimated synchrotron radiation bundle maintained at a constant intensity level, and the output signal was determined from about 100 points on the objective. Finally, two or three points on the objective were illuminated by synchrotron radiation at several different intensity levels covering the dynamic range of the photometers. The output signals were placed on an absolute basis by the electron counting technique described earlier.

  9. Unconventional use of intense pulsed light.

    PubMed

    Piccolo, D; Di Marcantonio, D; Crisman, G; Cannarozzo, G; Sannino, M; Chiricozzi, A; Chimenti, S

    2014-01-01

    According to the literature, intense pulsed light (IPL) represents a versatile tool in the treatment of some dermatological conditions (i.e., pigmentation disorders, hair removal, and acne), due to its wide range of wavelengths. The authors herein report on 58 unconventional but effective uses of IPL in several cutaneous diseases, such as rosacea (10 cases), port-wine stain (PWS) (10 cases), disseminated porokeratosis (10 cases), pilonidal cyst (3 cases), seborrheic keratosis (10 cases), hypertrophic scar (5 cases) and keloid scar (5 cases), Becker's nevus (2 cases), hidradenitis suppurativa (2 cases), and sarcoidosis (1 case). Our results should suggest that IPL could represent a valid therapeutic support and option by providing excellent outcomes and low side effects, even though it should be underlined that the use and the effectiveness of IPL are strongly related to the operator's experience (acquired by attempting at least one specific course on the use of IPL and one-year experience in a specialized centre). Moreover, the daily use of these devices will surely increase clinical experience and provide new information, thus enhancing long-term results and improving IPL effectiveness.

  10. Interactive effects of photoperiod and light intensity on blood physiological and biochemical reactions of broilers grown to heavy weights.

    PubMed

    Olanrewaju, H A; Purswell, J L; Collier, S D; Branton, S L

    2013-04-01

    The effects of photoperiod, light intensity, and their interaction on blood acid-base balance, metabolites, and electrolytes in broiler chickens under environmentally controlled conditions were examined in 2 trials. A 3 × 3 factorial experiment in a randomized complete block design was used in this study. In each trial, all treatment groups were provided 23L:1D with 20 lx of intensity from placement to 7 d, and then subjected to the treatments. The 9 treatments consisted of 3 photoperiods [long/continuous (23L:1D) from d 8 to 56, regular/intermittent (2L:2D), and short/nonintermittent (8L:16D) from d 8 to 48 and 23L:1D from d 49 to 56, respectively] and exposure to 3 light intensities (10, 5.0, and 0.5 lx) from d 8 through d 56 at 50% RH. Feed and water were provided ad libitum. Venous blood samples were collected on d 7, 14, 28, 42, and 56. Main effects indicated that short/nonintermittent photoperiod significantly (P < 0.05) reduced BW, pH, partial pressure of O2, saturated O2, Na(+), K(+), Ca(2+), Cl(-), osmolality, triiodothyronine (T3), and total protein along with significantly (P < 0.05) elevated partial pressure of CO2, hematocrit, hemoglobin, and lactate concentrations. In addition, there were no effects of photoperiod on HCO3(-), glucose, anion gap, and thyroxine (T4). Plasma corticosterone was not affected by photoperiod, light intensity, or their interaction. There was no effect of light intensity on most of the blood variables examined. Acid-base regulation during photoperiod and light intensity exposure did not deteriorate despite a lower pH and higher partial pressure of CO2 with normal HCO3(-). These results indicate that continuous exposure of broiler chickens to varying light intensities had a minor effect on blood physiological variables, whereas the short photoperiod markedly affected most blood physiological variables without inducing physiological stress in broilers.

  11. Ca²⁺ signal contributing to the synthesis and emission of monoterpenes regulated by light intensity in Lilium 'siberia'.

    PubMed

    Hu, Zenghui; Li, Tianjiao; Zheng, Jian; Yang, Kai; He, Xiangfeng; Leng, Pingsheng

    2015-06-01

    The floral scent is an important part of plant volatile compounds, and is influenced by environmental factors. The emission of monoterpenes of Lilium 'siberia' is regulated by light intensity, but the mechanism is large unknown. In this study, the expression of Li-mTPS, a monoterpene synthase gene in the tepals of Lilium 'siberia', and net Ca(2+) flux were investigated after exposure to different levels of light intensity (0, 100, 300, 600, 1000, and 1500 μmol m(-2) s(-1)). Moreover the effect of LaCl3 and ethylene glycol-bis-(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) on the Li-mTPS expression, monoterpene emission, and net Ca(2+) flux were examined at 600 μmol m(-2) s(-1). The results showed that along with the enhancement of light intensity, the expression level of Li-mTPS increased gradually, and the net Ca(2+) influx was also enhanced showing a similar pattern. It was found that LaCl3 and EGTA effectively inhibited the increase in expression of Li-mTPS and the net Ca(2+) influx induced by light treatment. Moreover, the release amounts of monoterpenes decreased significantly after treatment with LaCl3 and EGTA. So it can be concluded that Ca(2+) signal contributed to the biosynthesis and emission of monoterpenes regulated by light intensity in Lilium 'siberia' tepals. The increased light intensity firstly triggered the Ca(2+) influx to cytoplasm, and then the gene expression of monoterpene synthases downstream was activated to regulate the biosynthesis and emission of monoterpenes. But in the signaling pathway other mechanisms were thought to be involved in the emission of monoterpenes regulated by light intensity, which need to be investigated in future research. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  12. Fast algal eco-toxicity assessment: Influence of light intensity and exposure time on Chlorella vulgaris inhibition by atrazine and DCMU.

    PubMed

    Camuel, Alexandre; Guieysse, Benoit; Alcántara, Cynthia; Béchet, Quentin

    2017-06-01

    In order to develop a rapid assay suitable for algal eco-toxicity assessments under conditions representative of natural ecosystems, this study evaluated the short-term (<1h) response of algae exposed to atrazine and DCMU using oxygen productivity measurements. When Chlorella vulgaris was exposed to these herbicides under 'standard' low light intensity (as prescribed by OECD201 guideline), the 20min-EC 50 values recorded via oxygen productivity (atrazine: 1.32±0.07μM; DCMU: 0.31±0.005μM) were similar the 96-h EC 50 recorded via algal growth (atrazine: 0.56μM; DCMU: 0.41μM), and within the range of values reported in the literature. 20min-EC50 values increased by factors of 3.0 and 2.1 for atrazine and DCMU, respectively, when light intensity increased from 60 to 1400μmolm -2 s -1 of photosynthetically active radiation, or PAR. Further investigation showed that exposure time significantly also impacted the sensitivity of C. vulgaris under high light intensity (>840μmolm -2 s -1 as PAR) as the EC 50 for atrazine and DCMU decreased by up to 6.2 and 2.1 folds, respectively, after 50min of exposure at a light irradiance of 1400μmolm -2 s -1 as PAR. This decrease was particularly marked at high light intensities and low algae concentrations and is explained by the herbicide disruption of the electron transfer chain triggering photo-inhibition at high light intensities. Eco-toxicity assessments aiming to understand the potential impact of toxic compounds on natural ecosystems should therefore be performed over sufficient exposure times (>20min for C. vulgaris) and under light intensities relevant to these ecosystems. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Flight control and landing precision in the nocturnal bee Megalopta is robust to large changes in light intensity

    PubMed Central

    Baird, Emily; Fernandez, Diana C.; Wcislo, William T.; Warrant, Eric J.

    2015-01-01

    Like their diurnal relatives, Megalopta genalis use visual information to control flight. Unlike their diurnal relatives, however, they do this at extremely low light intensities. Although Megalopta has developed optical specializations to increase visual sensitivity, theoretical studies suggest that this enhanced sensitivity does not enable them to capture enough light to use visual information to reliably control flight in the rainforest at night. It has been proposed that Megalopta gain extra sensitivity by summing visual information over time. While enhancing the reliability of vision, this strategy would decrease the accuracy with which they can detect image motion—a crucial cue for flight control. Here, we test this temporal summation hypothesis by investigating how Megalopta's flight control and landing precision is affected by light intensity and compare our findings with the results of similar experiments performed on the diurnal bumblebee Bombus terrestris, to explore the extent to which Megalopta's adaptations to dim light affect their precision. We find that, unlike Bombus, light intensity does not affect flight and landing precision in Megalopta. Overall, we find little evidence that Megalopta uses a temporal summation strategy in dim light, while we find strong support for the use of this strategy in Bombus. PMID:26578977

  14. White noise analysis of Phycomyces light growth response system. I. Normal intensity range.

    PubMed Central

    Lipson, E D

    1975-01-01

    The Wiener-Lee-Schetzen method for the identification of a nonlinear system through white gaussian noise stimulation was applied to the transient light growth response of the sporangiophore of Phycomyces. In order to cover a moderate dynamic range of light intensity I, the imput variable was defined to be log I. The experiments were performed in the normal range of light intensity, centered about I0 = 10(-6) W/cm2. The kernels of the Wierner functionals were computed up to second order. Within the range of a few decades the system is reasonably linear with log I. The main nonlinear feature of the second-order kernel corresponds to the property of rectification. Power spectral analysis reveals that the slow dynamics of the system are of at least fifth order. The system can be represented approximately by a linear transfer function, including a first-order high-pass (adaptation) filter with a 4 min time constant and an underdamped fourth-order low-pass filter. Accordingly a linear electronic circuit was constructed to simulate the small scale response characteristics. In terms of the adaptation model of Delbrück and Reichardt (1956, in Cellular Mechanisms in Differentiation and Growth, Princeton University Press), kernels were deduced for the dynamic dependence of the growth velocity (output) on the "subjective intensity", a presumed internal variable. Finally the linear electronic simulator above was generalized to accommodate the large scale nonlinearity of the adaptation model and to serve as a tool for deeper test of the model. PMID:1203444

  15. Numerical study of the light output intensity of the bilayer organic light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Lu, Feiping

    2017-02-01

    The structure of organic light-emitting diodes (OLEDs) is one of most important issues that influence the light output intensity (LOI) of OLEDs. In this paper, based on a simple but accurate optical model, the influences of hole and electron transport layer thickness on the LOI of bilayer OLEDs, which with N,N0- bis(naphthalen-1-yl)-N,N0- bis(phenyl)- benzidine (NPB) or N,N'- diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4-diamine (TPD) as hole transport layer, with tris(8-hydroxyquinoline) aluminum (Alq3) as electron transport and light emitting layers, were investigated. The laws of LOI for OLEDs under different organic layer thickness values were obtained. The results show that the LOI of devices varies in accordance with damped cosine or sine function as the increasing of organic layer thickness, and the results show that the bilayer OLEDs with the structure of Glass/ITO/NPB (55 nm)/Alq3 (75 nm)/Al and Glass/ITO/TPB (60 nm)/Alq3 (75 nm)/Al have most largest LOI. When the thickness of Alq3 is less than 105 nm, the OLEDs with TPD as hole transport layer have larger LOI than that with NPB as hole transport layer. The results obtained in this paper can present an in-depth understanding of the working mechanism of OLEDs and help ones fabricate high efficiency OLEDs.

  16. Method and apparatus for measuring the intensity and phase of an ultrashort light pulse

    DOEpatents

    Kane, Daniel J.; Trebino, Rick P.

    1998-01-01

    The pulse shape I(t) and phase evolution x(t) of ultrashort light pulses are obtained using an instantaneously responding nonlinear optical medium to form a signal pulse. A light pulse, such a laser pulse, is split into a gate pulse and a probe pulse, where the gate pulse is delayed relative to the probe pulse. The gate pulse and the probe pulse are combined within an instantaneously responding optical medium to form a signal pulse functionally related to a temporal slice of the gate pulse corresponding to the time delay of the probe pulse. The signal pulse is then input to a wavelength-selective device to output pulse field information comprising intensity vs. frequency for a first value of the time delay. The time delay is varied over a range of values effective to yield an intensity plot of signal intensity vs. wavelength and delay. In one embodiment, the beams are overlapped at an angle so that a selected range of delay times is within the intersection to produce a simultaneous output over the time delays of interest.

  17. Proteomic Study Related to Vascular Connections in Watermelon Scions Grafted onto Bottle-Gourd Rootstock under Different Light Intensities

    PubMed Central

    Muneer, Sowbiya; Ko, Chung Ho; Soundararajan, Prabhakaran; Manivnnan, Abinaya; Park, Yoo Gyeong; Jeong, Byoung Ryong

    2015-01-01

    Although grafting is broadly used in the production of crops, no information is available about the proteins involved in vascular connections between rootstock and scion. Similarly, proteome changes under the light intensities widely used for grafted seedlings are of practical use. The objective of this study was to determine the proteome of vascular connections using watermelon (Citrullus vulgaris Schrad.) ‘Sambok Honey’ and ‘Speed’ as the scion and bottle gourd (Lagenaria siceraria Stanld.) ‘RS Dongjanggun’ as the rootstock grown under different light intensities (25, 50, 75 and 100 μmol m−2 s−1). Our proteomic analysis revealed 24 and 27 differentially expressed proteins in ‘Sambok Honey’ and ‘Speed’, respectively, under different light intensities. The identified proteins were largely involved in ion binding, amino acid metabolism, transcriptional regulation and defense response. The enhancement of ion-binding, transcriptional regulation, amino acid metabolism, and defense response proteins suggests a strengthening of the connection between the rootstock and scion under high light intensity. Indeed, the accumulation of key enzymes in the biological processes described above appears to play an important role in the vascular connections of grafted seedlings. Moreover, it appears that 100 μmol m−2 s−1 results in better protein expression responses in grafted seedlings. PMID:25789769

  18. Proteomic study related to vascular connections in watermelon scions grafted onto bottle-gourd rootstock under different light intensities.

    PubMed

    Muneer, Sowbiya; Ko, Chung Ho; Soundararajan, Prabhakaran; Manivnnan, Abinaya; Park, Yoo Gyeong; Jeong, Byoung Ryong

    2015-01-01

    Although grafting is broadly used in the production of crops, no information is available about the proteins involved in vascular connections between rootstock and scion. Similarly, proteome changes under the light intensities widely used for grafted seedlings are of practical use. The objective of this study was to determine the proteome of vascular connections using watermelon (Citrullus vulgaris Schrad.) 'Sambok Honey' and 'Speed' as the scion and bottle gourd (Lagenaria siceraria Stanld.) 'RS Dongjanggun' as the rootstock grown under different light intensities (25, 50, 75 and 100 μmol m-2 s-1). Our proteomic analysis revealed 24 and 27 differentially expressed proteins in 'Sambok Honey' and 'Speed', respectively, under different light intensities. The identified proteins were largely involved in ion binding, amino acid metabolism, transcriptional regulation and defense response. The enhancement of ion-binding, transcriptional regulation, amino acid metabolism, and defense response proteins suggests a strengthening of the connection between the rootstock and scion under high light intensity. Indeed, the accumulation of key enzymes in the biological processes described above appears to play an important role in the vascular connections of grafted seedlings. Moreover, it appears that 100 μmol m-2 s-1 results in better protein expression responses in grafted seedlings.

  19. Development of acousto-optic spatial light modulator unit for effective control of light beam intensity and diffraction angle in 3D holographic display applications

    NASA Astrophysics Data System (ADS)

    Kondalkar, Vijay V.; Ryu, Geonhee; Lee, Yongbeom; Lee, Keekeun

    2018-07-01

    An acousto-optic (AO) based holographic display unit was developed using surface acoustic wave (SAW) with different wavelength to modulate the diffraction angles, intensities, and phases of light. The new configurations were employed to control two beams simultaneously by using a single chirp inter-digital transducer (IDT), and a micro-lens array was integrated at the end of the waveguide layer to focus the diffracted light on to the screen. Two incident light beams were simultaneously modulated by using different refractive grating periods generated from chirp IDT. A diffraction angle of about 5° was obtained by using a SAW with a frequency of 430 MHz. The increase in the SAW input power enhances the diffraction efficiency of the light beam at the exit. The obtained maximum diffraction efficiency is ~70% at a frequency of 430 MHz. The sloped shape of the waveguide entrance and a tall rounded Ni poles help in coupling the incident light to the waveguide layer. The diffracted beam was collected through the lens, which increased the intensity of light in the viewing plane. COMSOL multi-physics and coupling of mode (COM) modeling were performed to predict the device performance and compared with the experimental results.

  20. Background light measurements in the deep ocean

    NASA Astrophysics Data System (ADS)

    Aoki, T.; Kitamura, T.; Matsuno, S.; Mitsui, K.; Ohashi, Y.

    1986-04-01

    The ambient light intensity at depths from 1500 to 4700 m at the DUMAND site near Hawaii is determined experimentally. The instrument (two 5-inch-diameter hemispherical photomultiplier elements enclosed in a glass sphere filled with transparent silicon gel, a cylindrical stainless-steel electronics housing, and an A1/PVC frame) and the data-processing techniques are described, and the results of both ship-suspended and bottom-tethered deployments are presented in graphs and characterized. The bottom-tethered data are shown to be stable, and the absolute flux (218 + 20 or - 60 photons/sq cm s) at 4700 m is considered consistent with the beta decay of K-40. Higher and less stable intensities in the ship-suspended data are attributed to bioluminescence stimulated by the motion of the instrument.

  1. The Intensity Modulation of the Fluorescent Line by a Finite Light Speed Effect in Accretion-powered X-Ray Pulsars

    NASA Astrophysics Data System (ADS)

    Yoshida, Yuki; Kitamoto, Shunji; Hoshino, Akio

    2017-11-01

    The X-ray line diagnostic method is a powerful tool for an investigation of plasma around accretion-powered X-ray pulsars. We point out an apparent intensity modulation of emission lines, with their rotation period of neutron stars, due to the finite speed of light (we call this effect the “finite light speed effect”) if the line emission mechanism is a kind of reprocessing, such as fluorescence or recombination after ionization by X-ray irradiation from pulsars. The modulation amplitude is determined by the size of the emission region, which is in competition with the smearing effect by the light crossing time in the emission region. This is efficient if the size of the emission region is roughly comparable to that of the rotation period multiplied by the speed of light. We apply this effect to a symbiotic X-ray pulsar, GX 1+4, where a spin modulation of the intense iron line of which has been reported. The finite light speed effect can explain the observed intensity modulation if its fluorescent region is the size of ˜ {10}12 cm.

  2. Absolute intensities for the Q-branch of the 3 nu(sub 2) (-) nu(sub 1) (465.161/cm) band of nitrous oxide

    NASA Technical Reports Server (NTRS)

    Sirota, J. Marcos; Reuter, Dennis C.

    1993-01-01

    The absolute intensities of four lines, Q 15-Q 18 in the 03(sup 1)0-10(sup 0)0 band, of N2O have been measured using a tunable diode laser spectrometer at temperatures between 380 and 420 K and pressures between 4 and 15 torr. Even though these transitions are weak and produced only about 2% of absorption at the line center for a pathlength of 52 m, they were measured with a signal to noise ratio of about 20 due to the high sensitivity of the instrument. The band strength derived is 1.03 x 10(exp -24) cm/molec at 296 K.

  3. [Effects of forest gap size and light intensity on herbaceous plants in Pinus koraiensis-dominated broadleaved mixed forest].

    PubMed

    Duan, Wen-Biao; Wang, Li-Xia; Chen, Li-Xin; Du, Shan; Wei, Quan-Shuai; Zhao, Jian-Hui

    2013-03-01

    1 m x 1 m fixed quadrats were parallelly arranged with a space of 2 m in each of six forest gaps in Pinus koraiensis-dominated broadleaved mixed forest, taking the gap center as the starting point and along east-west and south-north directions. In each quadrat, the coverage and abundance of herbaceous plants at different height levels were investigated by estimation method in June and September 2011, and the matrix characteristics within the quadrats were recorded. Canopy analyzer was used to take fish-eye photos in the selected overcast days in each month from June to September, 2011, and the relative light intensity was calculated by using Gap Light Analyzer 2.0 software. The differences in the relative light intensity and herbaceous plants coverage and richness between different gaps as well as the correlations between the coverage of each species and the direct light, diffuse light, and matrix were analyzed. The results showed that in opening areas and under canopy, the relative light intensity in large gaps was higher than that in small gaps, and the variation ranges of diffuse light and direct light from gap center to gap edge were bigger in large gaps than in small gaps. The direct light reaching at the ground both in large gaps and in small gaps was higher in the north than in the south direction. In the Z1, Z2, Z3, and Z4 zones, both the coverage and the richness of herbaceous plants were larger in large gaps than in small gaps, and the differences of species richness between large and small gaps reached significant level. The coverage of the majority of the herbaceous plants had significant correlations with diffuse light and matrix, and only the coverage of a few herbaceous plants was correlated with direct light.

  4. 14 CFR 23.1391 - Minimum intensities in the horizontal plane of position lights.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...: Dihedral angle (light included) Angle from right or left of longitudinal axis, measured from dead ahead Intensity (candles) L and R (red and green) 0° to 10°10° to 20° 20° to 110° 4030 5 A (rear white) 110° to...

  5. 14 CFR 23.1391 - Minimum intensities in the horizontal plane of position lights.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...: Dihedral angle (light included) Angle from right or left of longitudinal axis, measured from dead ahead Intensity (candles) L and R (red and green) 0° to 10°10° to 20° 20° to 110° 4030 5 A (rear white) 110° to...

  6. 14 CFR 23.1391 - Minimum intensities in the horizontal plane of position lights.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...: Dihedral angle (light included) Angle from right or left of longitudinal axis, measured from dead ahead Intensity (candles) L and R (red and green) 0° to 10°10° to 20° 20° to 110° 4030 5 A (rear white) 110° to...

  7. 14 CFR 23.1391 - Minimum intensities in the horizontal plane of position lights.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...: Dihedral angle (light included) Angle from right or left of longitudinal axis, measured from dead ahead Intensity (candles) L and R (red and green) 0° to 10°10° to 20° 20° to 110° 4030 5 A (rear white) 110° to...

  8. Pentoses and light intensity increase the growth and carbohydrate production and alter the protein profile of Chlorella minutissima.

    PubMed

    Freitas, B C B; Cassuriaga, A P A; Morais, M G; Costa, J A V

    2017-08-01

    High concentrations of carbon, which is considered a necessary element, are required for microalgal growth. Therefore, the identification of alternative carbon sources available in large quantities is increasingly important. This study evaluated the effects of light variation and pentose addition on the carbohydrate content and protein profile of Chlorella minutissima grown in a raceway photobioreactor. The kinetic parameters, carbohydrate content, and protein profile of Chlorella minutissima and its theoretical potential for ethanol production were estimated. The highest cellular concentrations were obtained with a light intensity of 33.75µmol.m -2 .s -1 . Arabinose addition combined with a light intensity of 33.75µmol.m -2 .s -1 increased the carbohydrate content by 53.8% and theoretically produced 39.1mL·100g -1 ethanol. All of the assays showed that a lower light availability altered the protein profile. The luminous intensity affects xylose and arabinose assimilation and augments the carbohydrate content in C. minutissima, making this microalga appropriate for bioethanol production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Measurement of absolute gamma emission probabilities

    NASA Astrophysics Data System (ADS)

    Sumithrarachchi, Chandana S.; Rengan, Krish; Griffin, Henry C.

    2003-06-01

    The energies and emission probabilities (intensities) of gamma-rays emitted in radioactive decays of particular nuclides are the most important characteristics by which to quantify mixtures of radionuclides. Often, quantification is limited by uncertainties in measured intensities. A technique was developed to reduce these uncertainties. The method involves obtaining a pure sample of a nuclide using radiochemical techniques, and using appropriate fractions for beta and gamma measurements. The beta emission rates were measured using a liquid scintillation counter, and the gamma emission rates were measured with a high-purity germanium detector. Results were combined to obtain absolute gamma emission probabilities. All sources of uncertainties greater than 0.1% were examined. The method was tested with 38Cl and 88Rb.

  10. Differential response of Scots pine seedlings to variable intensity and ratio of red and far-red light.

    PubMed

    Razzak, Abdur; Ranade, Sonali Sachin; Strand, Åsa; García-Gil, M R

    2017-08-01

    We investigated the response to increasing intensity of red (R) and far-R (FR) light and to a decrease in R:FR ratio in Pinus sylvestris L. (Scots pine) seedling. The results showed that FR high-irradiance response for hypocotyl elongation may be present in Scots pine and that this response is enhanced by increasing light intensity. However, both hypocotyl inhibition and pigment accumulation were more strongly affected by the R light compared with FR light. This is in contrast to previous reports in Arabidopsis thaliana (L.) Heynh. In the angiosperm, A. thaliana R light shows an overall milder effect on inhibition of hypocotyl elongation and on pigment biosynthesis compared with FR suggesting conifers and angiosperms respond very differently to the different light regimes. Scots pine shade avoidance syndrome with longer hypocotyls, shorter cotyledons and lower chlorophyll content in response to shade conditions resembles the response observed in A. thaliana. However, anthocyanin accumulation increased with shade in Scots pine, which again differs from what is known in angiosperms. Overall, the response of seedling development and physiology to R and FR light in Scots pine indicates that the regulatory mechanism for light response may differ between gymnosperms and angiosperms. © 2017 John Wiley & Sons Ltd.

  11. An analysis of scattered light in low dispersion IUE spectra

    NASA Technical Reports Server (NTRS)

    Basri, G.; Clarke, J. T.; Haisch, B. M.

    1985-01-01

    A detailed numerical simulation of light scattering from the low-resolution grating in the short wavelength spectrograph of the IUE Observatory was developed, in order to quantitatively analyze the effects of scattering on both continuum and line emission spectra. It is found that: (1) the redistribution of light by grating scattering did not appreciably alter either the shape or the absolute flux level of continuum spectra for A-F stars; (2) late-type stellar continua showed a tendency to flatten when observed in scattered light toward the shorter wavelengths; and (3) the effect of grating scattering on emission lines is to decrease measured line intensities by an increasing percentage toward the shorter wavelengths. The spectra obtained from scattering experiments for solar-type and late type stars are reproduced in graphic form.

  12. Analysis of standard reference materials by absolute INAA

    NASA Astrophysics Data System (ADS)

    Heft, R. E.; Koszykowski, R. F.

    1981-07-01

    Three standard reference materials: flyash, soil, and ASI 4340 steel, are analyzed by a method of absolute instrumental neutron activation analysis. Two different light water pool-type reactors were used to produce equivalent analytical results even though the epithermal to thermal flux ratio in one reactor was higher than that in the other by a factor of two.

  13. GLIDE: a grid-based light-weight infrastructure for data-intensive environments

    NASA Technical Reports Server (NTRS)

    Mattmann, Chris A.; Malek, Sam; Beckman, Nels; Mikic-Rakic, Marija; Medvidovic, Nenad; Chrichton, Daniel J.

    2005-01-01

    The promise of the grid is that it will enable public access and sharing of immense amounts of computational and data resources among dynamic coalitions of individuals and institutions. However, the current grid solutions make several limiting assumptions that curtail their widespread adoption. To address these limitations, we present GLIDE, a prototype light-weight, data-intensive middleware infrastructure that enables access to the robust data and computational power of the grid on DREAM platforms.

  14. Long lifetime, low intensity light source for use in nighttime viewing of equipment maps and other writings

    DOEpatents

    Frank, Alan M.; Edwards, William R.

    1983-01-01

    A long-lifetime light source with sufficiently low intensity to be used for reading a map or other writing at nighttime, while not obscuring the user's normal night vision. This light source includes a diode electrically connected in series with a small power source and a lens properly positioned to focus at least a portion of the light produced by the diode.

  15. First Absolutely Calibrated Localized Measurements of Ion Velocity in the MST in Locked and Rotating Plasmas

    NASA Astrophysics Data System (ADS)

    Baltzer, M.; Craig, D.; den Hartog, D. J.; Nornberg, M. D.; Munaretto, S.

    2015-11-01

    An Ion Doppler Spectrometer (IDS) is used on MST for high time-resolution passive and active measurements of impurity ion emission. Absolutely calibrated measurements of flow are difficult because the spectrometer records data within 0.3 nm of the C+5 line of interest, and commercial calibration lamps do not produce lines in this narrow range . A novel optical system was designed to absolutely calibrate the IDS. The device uses an UV LED to produce a broad emission curve in the desired region. A Fabry-Perot etalon filters this light, cutting transmittance peaks into the pattern of the LED emission. An optical train of fused silica lenses focuses the light into the IDS with f/4. A holographic diffuser blurs the light cone to increase homogeneity. Using this light source, the absolute Doppler shift of ion emissions can be measured in MST plasmas. In combination with charge exchange recombination spectroscopy, localized ion velocities can now be measured. Previously, a time-averaged measurement along the chord bisecting the poloidal plane was used to calibrate the IDS; the quality of these central chord calibrations can be characterized with our absolute calibration. Calibration errors may also be quantified and minimized by optimizing the curve-fitting process. Preliminary measurements of toroidal velocity in locked and rotating plasmas will be shown. This work has been supported by the US DOE.

  16. Intensity and angle-of-arrival spectra of laser light propagating through axially homogeneous buoyancy-driven turbulence.

    PubMed

    Pawar, Shashikant S; Arakeri, Jaywant H

    2016-08-01

    Frequency spectra obtained from the measurements of light intensity and angle of arrival (AOA) of parallel laser light propagating through the axially homogeneous, axisymmetric buoyancy-driven turbulent flow at high Rayleigh numbers in a long (length-to-diameter ratio of about 10) vertical tube are reported. The flow is driven by an unstable density difference created across the tube ends using brine and fresh water. The highest Rayleigh number is about 8×109. The aim of the present work is to find whether the conventional Obukhov-Corrsin scaling or Bolgiano-Obukhov (BO) scaling is obtained for the intensity and AOA spectra in the case of light propagation in a buoyancy-driven turbulent medium. Theoretical relations for the frequency spectra of log amplitude and AOA fluctuations developed for homogeneous isotropic turbulent media are modified for the buoyancy-driven flow in the present case to obtain the asymptotic scalings for the high and low frequency ranges. For low frequencies, the spectra of intensity and vertical AOA fluctuations obtained from measurements follow BO scaling, while scaling for the spectra of horizontal AOA fluctuations shows a small departure from BO scaling.

  17. Modulation transfer function of partial gating detector by liquid crystal auto-controlling light intensity

    NASA Astrophysics Data System (ADS)

    Yang, Xusan; Tang, Yuanhe; Liu, Kai; Liu, Hanchen; Gao, Haiyang; Li, Qing; Zhang, Ruixia; Ye, Na; Liang, Yuan; Zhao, Gaoxiang

    2008-12-01

    Based on the electro-optical properties of liquid crystal, we have designed a novel partial gating detector. Liquid crystal can be taken to change its own transmission according to the light intensity outside. Every single pixel of the image is real-time modulated by liquid crystal, thus the strong light is weakened and low light goes through the detector normally .The purpose of partial-gating strong light (>105lx) can be achieved by this detector. The modulation transfer function (MTF) equations of the main optical sub-systems are calculated in this paper, they are liquid crystal panels, linear fiber panel and CCD array detector. According to the relevant size, the MTF value of this system is fitted out. The result is MTF= 0.518 at Nyquist frequency.

  18. Reducing sound and light exposure to improve sleep on the adult intensive care unit: An inclusive narrative review.

    PubMed

    Bion, Victoria; Lowe, Alex Sw; Puthucheary, Zudin; Montgomery, Hugh

    2018-05-01

    Sleep disturbance is common in intensive care units. It is associated with detrimental psychological impacts and has potential to worsen outcome. Irregular exposure to sound and light may disrupt circadian rhythm and cause frequent arousals from sleep. We sought to review the efficacy of environmental interventions to reduce sound and light exposure with the aim of improving patient sleep on adult intensive care units. We searched both PubMed (1966-30 May 2017) and Embase (1974-30 May 2017) for all relevant human (adult) studies and meta-analyses published in English using search terms ((intensive care OR critical care), AND (sleep OR sleep disorders), AND (light OR noise OR sound)). Bibliographies were explored. Articles were included if reporting change in patient sleep in response to an intervention to reduce disruptive intensive care unit sound /light exposure. Fifteen studies were identified. Nine assessed mechanical interventions, four of which used polysomnography to assess sleep. Five studies looked at environmental measures to facilitate sleep and a further two (one already included as assessing a mechanical intervention) studied the use of sound to promote sleep. Most studies found a positive impact of the intervention on sleep. However, few studies used objective sleep assessments, sample sizes were small, methodologies sometimes imperfect and analysis limited. Data are substantially derived from specialist (neurosurgical, post-operative, cardiothoracic and cardiological) centres. Patients were often at the 'less sick' end of the spectrum in a variety of settings (open ward beds or side rooms). Simple measures to reduce intensive care unit patient sound/light exposure appear effective. However, larger and more inclusive high-quality studies are required in order to identify the measures most effective in different patient groups and any impacts on outcome.

  19. Unconventional Use of Intense Pulsed Light

    PubMed Central

    Piccolo, D.; Di Marcantonio, D.; Crisman, G.; Cannarozzo, G.; Sannino, M.; Chiricozzi, A.; Chimenti, S.

    2014-01-01

    According to the literature, intense pulsed light (IPL) represents a versatile tool in the treatment of some dermatological conditions (i.e., pigmentation disorders, hair removal, and acne), due to its wide range of wavelengths. The authors herein report on 58 unconventional but effective uses of IPL in several cutaneous diseases, such as rosacea (10 cases), port-wine stain (PWS) (10 cases), disseminated porokeratosis (10 cases), pilonidal cyst (3 cases), seborrheic keratosis (10 cases), hypertrophic scar (5 cases) and keloid scar (5 cases), Becker's nevus (2 cases), hidradenitis suppurativa (2 cases), and sarcoidosis (1 case). Our results should suggest that IPL could represent a valid therapeutic support and option by providing excellent outcomes and low side effects, even though it should be underlined that the use and the effectiveness of IPL are strongly related to the operator's experience (acquired by attempting at least one specific course on the use of IPL and one-year experience in a specialized centre). Moreover, the daily use of these devices will surely increase clinical experience and provide new information, thus enhancing long-term results and improving IPL effectiveness. PMID:25276803

  20. The dual rod system of amphibians supports colour discrimination at the absolute visual threshold

    PubMed Central

    Yovanovich, Carola A. M.; Koskela, Sanna M.; Nevala, Noora; Kondrashev, Sergei L.

    2017-01-01

    The presence of two spectrally different kinds of rod photoreceptors in amphibians has been hypothesized to enable purely rod-based colour vision at very low light levels. The hypothesis has never been properly tested, so we performed three behavioural experiments at different light intensities with toads (Bufo) and frogs (Rana) to determine the thresholds for colour discrimination. The thresholds of toads were different in mate choice and prey-catching tasks, suggesting that the differential sensitivities of different spectral cone types as well as task-specific factors set limits for the use of colour in these behavioural contexts. In neither task was there any indication of rod-based colour discrimination. By contrast, frogs performing phototactic jumping were able to distinguish blue from green light down to the absolute visual threshold, where vision relies only on rod signals. The remarkable sensitivity of this mechanism comparing signals from the two spectrally different rod types approaches theoretical limits set by photon fluctuations and intrinsic noise. Together, the results indicate that different pathways are involved in processing colour cues depending on the ecological relevance of this information for each task. This article is part of the themed issue ‘Vision in dim light’. PMID:28193811

  1. Error correcting coding-theory for structured light illumination systems

    NASA Astrophysics Data System (ADS)

    Porras-Aguilar, Rosario; Falaggis, Konstantinos; Ramos-Garcia, Ruben

    2017-06-01

    Intensity discrete structured light illumination systems project a series of projection patterns for the estimation of the absolute fringe order using only the temporal grey-level sequence at each pixel. This work proposes the use of error-correcting codes for pixel-wise correction of measurement errors. The use of an error correcting code is advantageous in many ways: it allows reducing the effect of random intensity noise, it corrects outliners near the border of the fringe commonly present when using intensity discrete patterns, and it provides a robustness in case of severe measurement errors (even for burst errors where whole frames are lost). The latter aspect is particular interesting in environments with varying ambient light as well as in critical safety applications as e.g. monitoring of deformations of components in nuclear power plants, where a high reliability is ensured even in case of short measurement disruptions. A special form of burst errors is the so-called salt and pepper noise, which can largely be removed with error correcting codes using only the information of a given pixel. The performance of this technique is evaluated using both simulations and experiments.

  2. Method and apparatus for making absolute range measurements

    DOEpatents

    Earl, Dennis D [Knoxville, TN; Allison, Stephen W [Knoxville, TN; Cates, Michael R [Oak Ridge, TN; Sanders, Alvin J [Knoxville, TN

    2002-09-24

    This invention relates to a method and apparatus for making absolute distance or ranging measurements using Fresnel diffraction. The invention employs a source of electromagnetic radiation having a known wavelength or wavelength distribution, which sends a beam of electromagnetic radiation through a screen at least partially opaque at the wavelength. The screen has an aperture sized so as to produce a Fresnel diffraction pattern. A portion of the beam travels through the aperture to a detector spaced some distance from the screen. The detector detects the central intensity of the beam as well as a set of intensities displaced from a center of the aperture. The distance from the source to the target can then be calculated based upon the known wavelength, aperture radius, and beam intensity.

  3. Correlation of spatial intensity distribution of light reaching the retina and restoration of vision by optogenetic stimulation

    NASA Astrophysics Data System (ADS)

    Shivalingaiah, Shivaranjani; Gu, Ling; Mohanty, Samarendra K.

    2011-03-01

    Stimulation of retinal neuronal cells using optogenetics via use of chanelrhodopsin-2 (ChR2) and blue light has opened up a new direction for restoration of vision with respect to treatment of Retinitis pigmentosa (RP). In addition to delivery of ChR2 to specific retinal layer using genetic engineering, threshold level of blue light needs to be delivered onto the retina for generating action potential and successful behavioral outcome. We report measurement of intensity distribution of light reaching the retina of Retinitis pigmentosa (RP) mouse models and compared those results with theoretical simulations of light propagation in eye. The parameters for the stimulating source positioning in front of eye was determined for optimal light delivery to the retina. In contrast to earlier viral method based delivery of ChR2 onto retinal ganglion cells, in-vivo electroporation method was employed for retina-transfection of RP mice. The behavioral improvement in mice with Thy1-ChR2-YFP transfected retina, expressing ChR2 in retinal ganglion cells, was found to correlate with stimulation intensity.

  4. Light at night acutely impairs glucose tolerance in a time-, intensity- and wavelength-dependent manner in rats.

    PubMed

    Opperhuizen, Anne-Loes; Stenvers, Dirk J; Jansen, Remi D; Foppen, Ewout; Fliers, Eric; Kalsbeek, Andries

    2017-07-01

    Exposure to light at night (LAN) has increased dramatically in recent decades. Animal studies have shown that chronic dim LAN induced obesity and glucose intolerance. Furthermore, several studies in humans have demonstrated that chronic exposure to artificial LAN may have adverse health effects with an increased risk of metabolic disorders, including type 2 diabetes. It is well-known that acute exposure to LAN affects biological clock function, hormone secretion and the activity of the autonomic nervous system, but data on the effects of LAN on glucose homeostasis are lacking. This study aimed to investigate the acute effects of LAN on glucose metabolism. Male Wistar rats were subjected to i.v. glucose or insulin tolerance tests while exposed to 2 h of LAN in the early or late dark phase. In subsequent experiments, different light intensities and wavelengths were used. LAN exposure early in the dark phase at ZT15 caused increased glucose responses during the first 20 min after glucose infusion (p < 0.001), whereas LAN exposure at the end of the dark phase, at ZT21, caused increased insulin responses during the first 10 min (p < 0.01), indicating that LAN immediately induces glucose intolerance in rats. Subsequent experiments demonstrated that the effect of LAN was both intensity- and wavelength-dependent. White light of 50 and 150 lx induced greater glucose responses than 5 and 20 lx, whereas all intensities other than 5 lx reduced locomotor activity. Green light induced glucose intolerance, but red and blue light did not, suggesting the involvement of a specific retina-brain pathway. Together, these data show that exposure to LAN has acute adverse effects on glucose metabolism in a time-, intensity- and wavelength-dependent manner.

  5. Effects of various LED light wavelengths and intensities on microalgae-based simultaneous biogas upgrading and digestate nutrient reduction process.

    PubMed

    Zhao, Yongjun; Wang, Juan; Zhang, Hui; Yan, Cheng; Zhang, Yuejin

    2013-05-01

    Biogas is a well-known, primary renewable energy source, but its utilizations are possible only after upgrading. The microalgae-based bag photo-bioreactor utilized in this research could effectively upgrade biogas and simultaneously reduce the nutrient content in digestate. Red light was determined as the optimal light wavelength for microalgae growth, biogas upgrading, and digestate nutrient reduction. In the range of moderate light intensities (i.e., 800, 1200, 1600, and 2000 μmol m(-2) s(-1)), higher light intensities achieved higher biogas upgrade and larger digestate nutrient reduction. Methane content attained the highest value of 92.74±3.56% (v/v). The highest chemical oxygen demand, total nitrogen, and total phosphorus reduction efficiency of digestate were 85.35±1.04%, 77.98±1.84%, and 73.03±2.14%, respectively. Considering the reduction and economic efficiencies of the carbon dioxide content of biogas and digestate nutrient as well as the biogas upgrading standard, the optimal light intensity range was determined to be from 1200 to 1600 μmol m(-2) s(-1). Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Long lifetime, low intensity light source for use in nighttime viewing of equipment maps and other writings

    DOEpatents

    Frank, A.M.; Edwards, W.R.

    1983-10-11

    A long-lifetime light source with sufficiently low intensity to be used for reading a map or other writing at nighttime, while not obscuring the user's normal night vision is disclosed. This light source includes a diode electrically connected in series with a small power source and a lens properly positioned to focus at least a portion of the light produced by the diode. 1 fig.

  7. Long lifetime, low intensity light source for use in nighttime viewing of equipment maps and other writings

    DOEpatents

    Frank, A.M.; Edwards, W.R.

    1982-03-23

    A long-lifetime light source is discussed with sufficiently low intensity to be used for reading a map or other writing at nightime, while not obscuring the user's normal night vision. This light source includes a diode electrically connected in series with a small power source and a lens properly positioned to focus at least a portion of the light produced by the diode.

  8. Automatic Suppression of Intense Monochromatic Light in Electro-Optical Sensors

    PubMed Central

    Ritt, Gunnar; Eberle, Bernd

    2012-01-01

    Electro-optical imaging sensors are widely distributed and used for many different tasks. Due to technical improvements, their pixel size has been steadily decreasing, resulting in a reduced saturation capacity. As a consequence, this progress makes them susceptible to intense point light sources. Developments in laser technology have led to very compact and powerful laser sources of any wavelength in the visible and near infrared spectral region, offered as laser pointers. The manifold of wavelengths makes it difficult to encounter sensor saturation over the complete operating waveband by conventional measures like absorption or interference filters. We present a concept for electro-optical sensors to suppress overexposure in the visible spectral region. The key element of the concept is a spatial light modulator in combination with wavelength multiplexing. This approach allows spectral filtering within a localized area in the field of view of the sensor. The system offers the possibility of automatic reduction of overexposure by monochromatic laser radiation. PMID:23202039

  9. [Effect of light intensity on the growth and digestive enzyme activity of juvenile sea cucumber Apostichopus japonicas under two kinds of culture methods].

    PubMed

    Wei, Zi-Zhong; Zhao, Wen

    2014-01-01

    The effects of light intensity (0, 1000, 2000 and 3000 1x) on the growth and digestive enzyme activity of juvenile sea cucumber Apostichopus japonicus under two kinds of culture methods (compound Chinese medicine preparation and microbial preparation) were studied. Results showed that the relative mass gain rate (WGR) and the specific growth rate (SGR) of juvenile sea cucumber were significantly affected by light intensity (P < 0.05) , and the orders of WGR and SGR (form high to low) of juvenile sea cucumber under different light intensities were 2000 1x > 1000 1x > 3000 1x > 0 1x. Under the same light intensity, the growth of juvenile sea cucumber under the two kinds of culture methods were significantly different (P < 0.05), with the WGR and SGR of the Chinese medicine treatment being greater than those of the microbial treatment. The light intensity also significantly affected the digestive enzyme activity of juvenile sea cucumber. The order of amylase and lipase activity was 2000 1x > 1000 1x > 3000 1x > 0 1x, while that of protease activity was 1000 1x > 2000 1x > 0 1x > 3000 1x. Under the same light intensity, the digestive enzyme activities of the Chinese medicine treatment were generally higher than those of the microbial treatment.

  10. Theoretical analysis of the effects of light intensity on the photocorrosion of semiconductor electrodes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Benito, R.M.; Nozik, A.J.

    1985-07-18

    A kinetic model was developed to describe the effects of light intensity on the photocorrosion of n-type semiconductor electrodes. The model is an extension of previous work by Gomes and co-workers that includes the possibility of multiple steps for the oxidation reaction of the reducing agent in the electrolyte. Six cases are considered where the semiconductor decomposition reaction is multistep (each step involves a hole); the oxidation reaction of the reducing agent is multistep (each step after the first involves a hole or a chemical intermediate), and the first steps of the competing oxidation reactions are reversible or irreversible. Itmore » was found, contrary to previous results, that the photostability of semiconductor electrodes could increase with increased light intensity if the desired oxidation reaction of the reducing agent in the electrolyte was multistep with the first step being reversible. 14 references, 5 figures, 1 table.« less

  11. Clinical application of intense pulsed light depilation technology in total auricular reconstruction.

    PubMed

    Guo, Ying; Shan, Jing; Zhang, Tianyu

    2017-08-01

    Although ear reconstruction technology has been highly developed in recent years, hair growth on the reconstructed ear has plagued both surgeons and patients. In this paper, the authors introduce a clinical application of intense pulsed light depilation in total auricular reconstruction. From August 2012 to August 2013, 27 patients (28 ears) suffering from congenital microtia were treated by intense pulsed light depilation (650-950-nm filter, initial fluence of 14-16 J/cm 2 and gradually increased, pulse width of 30-50 ms, spot size of 20 × 30 mm 2 , intervals of 6-8 weeks, a total of four sessions) either before or after auricular reconstruction. According to the treatment situation at diagnosis, the patients were divided into two groups: the preoperative group and the postoperative group. There were no differences between the two groups in terms of age or initial fluence for hair removal; however, there were less treatments in the former than in the latter group (preoperative group 4.1 ± 0.3, postoperative group 4.7 ± 0.7, F = 9.10, P = 0.006), and the maximum fluence used for hair removal was lower in the former than in the latter group (preoperative group 18-20 J/cm 2 , postoperative group 19-22 J/cm 2 , F = 22.31, P < 0.001). After follow-up for ≥4-6 months, the effective rate was 100% in the preoperative group, and the effective rate was 80% in the postoperative group. Intense pulsed light depilation technology is a reasonable complementary approach to total auricular reconstruction. And preoperative depilation is recommended over postoperative depilation. The non-invasive modern photonic technology can resolve the problem of postoperative residual hair on the reconstructed auricle, improving auricular shape and increasing patient satisfaction. In addition, an adequately set preoperative hair removal area can provide surface skin that is most similar to normal auricle skin for auricular reconstruction.

  12. Biocapture of CO₂ by Different Microalgal-Based Technologies for Biogas Upgrading and Simultaneous Biogas Slurry Purification under Various Light Intensities and Photoperiods.

    PubMed

    Guo, Pengfei; Zhang, Yuejin; Zhao, Yongjun

    2018-03-15

    Abstract : Co-cultivation of microalgae and microbes for pollutant removal from sewage is considered as an effective wastewater treatment method. The aim of this study is to screen the optimal photoperiod, light intensity and microalgae co-cultivation method for simultaneously removing nutrients in biogas slurry and capturing CO₂ in biogas. The microalgae-fungi pellets are deemed to be a viable option because of their high specific growth rate and nutrient and CO 2 removal efficiency under the photoperiod of 14 h light:10 h dark. The order of both the biogas slurry purification and biogas upgrading is ranked the same, that is Chlorella vulga ris - Ganoderma lucidum > Chlorella vulga ris -activated sludge > Chlorella vulgaris under different light intensities. For all cultivation methods, the moderate light intensity of 450 μmol m -2 s -1 is regarded as the best choice. This research revealed that the control of photoperiod and light intensity can promote the biological treatment process of biogas slurry purification and biogas upgrading using microalgal-based technology.

  13. Sound Velocity and Diffraction Intensity Measurements Based on Raman-Nath Theory of the Interaction of Light and Ultrasound

    ERIC Educational Resources Information Center

    Neeson, John F.; Austin, Stephen

    1975-01-01

    Describes a method for the measurement of the velocity of sound in various liquids based on the Raman-Nath theory of light-sound interaction. Utilizes an analog computer program to calculate the intensity of light scattered into various diffraction orders. (CP)

  14. Effect of Light Intensity for Optimum Biomass and Lipid Production from Scenedesmus dimorphus (Turpin) Kützing

    NASA Astrophysics Data System (ADS)

    Kurniawati, F. N.; Mahajoeno, E.; Sunarto; Sari, S. L. A.

    2017-07-01

    One source of alternative energy substitute for petroleum raw materials is renewable vegetable oils known as biodiesel. Biodiesel can be produced from microalgae, since it was more efficient and environmentally friendly. Scenedesmus dimorphus (Turpin) Kützing was developed as a source of biodiesel since it had potential of high lipid production. The aims of this research were to know the rate of growth of Scenedesmus dimorphus in different lighting and the optimimum light intensity for biomass and lipid production. This research used a completely randomized design consisting of 3 treatments with 3 replications. Treatments in this research were the light intensity, i.e. 7,500, 10,000, and 12,500 lux. Scenedesmus dimorphus was grew in Bold’s Basal Medium (BBM). Parameters observed in this research were the cell number, biomass and lipid production of S. dimorphus. Data were analyzed by ANOVA followed by DMRT 5%. The results showed that the optimum growth rate of S. dimorphus was in the intensity of 12,500 lux that was 100.80 x 106 cells.ml-1. The optimum production of biomass and lipids was in treatment 12,500 lux i.e; 1.1407 g.L-1 and 0.2520 g.L-1 (22.28% dry weight).

  15. Absolute Parameters for the F-type Eclipsing Binary BW Aquarii

    NASA Astrophysics Data System (ADS)

    Maxted, P. F. L.

    2018-05-01

    BW Aqr is a bright eclipsing binary star containing a pair of F7V stars. The absolute parameters of this binary (masses, radii, etc.) are known to good precision so they are often used to test stellar models, particularly in studies of convective overshooting. ... Maxted & Hutcheon (2018) analysed the Kepler K2 data for BW Aqr and noted that it shows variability between the eclipses that may be caused by tidally induced pulsations. ... Table 1 shows the absolute parameters for BW Aqr derived from an improved analysis of the Kepler K2 light curve plus the RV measurements from both Imbert (1979) and Lester & Gies (2018). ... The values in Table 1 with their robust error estimates from the standard deviation of the mean are consistent with the values and errors from Maxted & Hutcheon (2018) based on the PPD calculated using emcee for a fit to the entire K2 light curve.

  16. Inhibition of enteric pathogens and surrogates using integrated, high intensity 405nm led light on the surface of almonds

    USDA-ARS?s Scientific Manuscript database

    The disinfecting properties of 405 nm light were investigated against Escherichia coli O157:H7, Salmonella, and their non-pathogenic surrogate bacteria on the surface of almonds. High intensity monochromatic blue light (MBL) was generated from an array of narrow-band 405 nm light-emitting diodes (LE...

  17. Absolute determination of local tropospheric OH concentrations

    NASA Technical Reports Server (NTRS)

    Armerding, Wolfgang; Comes, Franz-Josef

    1994-01-01

    Long path absorption (LPA) according to Lambert Beer's law is a method to determine absolute concentrations of trace gases such as tropospheric OH. We have developed a LPA instrument which is based on a rapid tuning of the light source which is a frequency doubled dye laser. The laser is tuned across two or three OH absorption features around 308 nm with a scanning speed of 0.07 cm(exp -1)/microsecond and a repetition rate of 1.3 kHz. This high scanning speed greatly reduces the fluctuation of the light intensity caused by the atmosphere. To obtain the required high sensitivity the laser output power is additionally made constant and stabilized by an electro-optical modulator. The present sensitivity is of the order of a few times 10(exp 5) OH per cm(exp 3) for an acquisition time of a minute and an absorption path length of only 1200 meters so that a folding of the optical path in a multireflection cell was possible leading to a lateral dimension of the cell of a few meters. This allows local measurements to be made. Tropospheric measurements have been carried out in 1991 resulting in the determination of OH diurnal variation at specific days in late summer. Comparison with model calculations have been made. Interferences are mainly due to SO2 absorption. The problem of OH self generation in the multireflection cell is of minor extent. This could be shown by using different experimental methods. The minimum-maximum signal to noise ratio is about 8 x 10(exp -4) for a single scan. Due to the small size of the absorption cell the realization of an open air laboratory is possible in which by use of an additional UV light source or by additional fluxes of trace gases the chemistry can be changed under controlled conditions allowing kinetic studies of tropospheric photochemistry to be made in open air.

  18. Study of resonance light scattering for remote optical probing

    NASA Technical Reports Server (NTRS)

    Penney, C. M.; Morey, W. W.; St. Peters, R. L.; Silverstein, S. D.; Lapp, M.; White, D. R.

    1973-01-01

    Enhanced scattering and fluorescence processes in the visible and UV were investigated which will enable improved remote measurements of gas properties. The theoretical relationship between scattering and fluorescence from an isolated molecule in the approach to resonance is examined through analysis of the time dependence of re-emitted light following excitation of pulsed incident light. Quantitative estimates are developed for the relative and absolute intensities of fluorescence and resonance scattering. New results are obtained for depolarization of scattering excited by light at wavelengths within a dissociative continuum. The experimental work was performed in two separate facilities. One of these utilizes argon and krypton lasers, single moded by a tilted etalon, and a 3/4 meter double monochromator. This facility was used to determine properties of the re-emission from NO2, I2 and O3 excited by visible light. The second facility involves a narrow-line dye laser, and a 3/4 meter single monochromator. The dye laser produces pulsed light with 5 nsec pulse duration and 0.005 nm spectral width.

  19. The impact of morning light intensity and environmental temperature on body temperatures and alertness.

    PubMed

    Te Kulve, Marije; Schlangen, Luc J M; Schellen, Lisje; Frijns, Arjan J H; van Marken Lichtenbelt, Wouter D

    2017-06-01

    Indoor temperature and light exposure are known to affect body temperature, productivity and alertness of building occupants. However, not much is known about the interaction between light and temperature exposure and the relationship between morning light induced alertness and its effect on body temperature. Light intensity and room temperature during morning office hours were investigated under strictly controlled conditions. In a randomized crossover study, two white light conditions (4000K, either bright 1200lx or dim 5lx) under three different room temperatures (26, 29 and 32°C) were investigated. A lower room temperature increased the core body temperature (CBT) and lowered skin temperature and the distal-proximal temperature gradient (DPG). Moreover, a lower room temperature reduced the subjective sleepiness and reaction time on an auditory psychomotor vigilance task (PVT), irrespective of the light condition. Interestingly, the morning bright light exposure did affect thermophysiological parameters, i.e. it decreased plasma cortisol, CBT and proximal skin temperature and increased the DPG, irrespective of the room temperature. During the bright light session, subjective sleepiness decreased irrespective of the room temperature. However, the change in sleepiness due to the light exposure was not related to these physiological changes. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Newton's absolute time and space in general relativity

    NASA Astrophysics Data System (ADS)

    Gautreau, Ronald

    2000-04-01

    I describe a reference system in a spherically symmetric gravitational field that is built around times recorded by radially moving geodesic clocks. The geodesic time coordinate t and the curvature spatial radial coordinate R result in spacetime descriptions of the motion of the geodesic clocks that are exactly identical with equations following from Newton's absolute time and space used with his inverse square law. I show how to use the resulting Newtonian/general-relativistic equations for geodesic clocks to generate exact relativistic metric forms in terms of the coordinates (R,t). Newtonian theory does not describe light. However, the motion of light can be determined from the (R,t) general-relativistic metric forms obtained from Newtonian theory by setting ds2(R,t)=0. In this sense, a theory of light can be related to absolute time and space of Newtonian gravitational theory. I illustrate the (R,t) methodology by first solving the equations that result from a Newtonian picture and then examining the exact metric forms for the general-relativistic problems of the Schwarzschild field, gravitational collapse and expansion of a zero-pressure perfect fluid, and zero-pressure big-bang cosmology. I also briefly describe other applications of the Newtonian/general-relativistic formulation to: embedding a Schwarzschild mass into cosmology; continuously following an expanding universe from radiation to matter domination; Dirac's Large Numbers hypothesis; the incompleteness of Kruskal-Szekeres spacetime; double valuedness in cosmology; and the de Sitter universe.

  1. Selected List of Low Energy Beam Transport Facilities for Light-Ion, High-Intensity Accelerators

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Prost, L. R.

    This paper presents a list of Low Energy Beam Transport (LEBT) facilities for light-ion, high-intensity accelerators. It was put together to facilitate comparisons with the PXIE LEBT design choices. A short discussion regarding the importance of the beam perveance in the choice of the transport scheme follows.

  2. Absolute measurements of the triplet-triplet annihilation rate and the charge-carrier recombination layer thickness in working polymer light-emitting diodes based on polyspirobifluorene

    NASA Astrophysics Data System (ADS)

    Rothe, C.; Al Attar, H. A.; Monkman, A. P.

    2005-10-01

    The triplet exciton densities in electroluminescent devices prepared from two polyspirobifluorene derivatives have been investigated by means of time-resolved transient triplet absorption as a function of optical and electrical excitation power at 20 K. Because of the low mobility of the triplet excitons at this temperature, the triplet generation profile within the active polymer layer is preserved throughout the triplet lifetime and as a consequence the absolute triplet-triplet annihilation efficiency is not homogeneously distributed but depends on position within the active layer. This then gives a method to measure the charge-carrier recombination layer after electrical excitation relative to the light penetration depth, which is identical to the triplet generation layer after optical excitation. With the latter being obtained from ellipsometry, an absolute value of 5 nm is found for the exciton formation layer in polyspirobifluorene devices. This layer increases to 11 nm if the balance between the electron and the hole mobility is improved by chemically modifying the polymer backbone. Also, and consistent with previous work, triplet diffusion is dispersive at low temperature. As a consequence of this, the triplet-triplet annihilation rate is not a constant in the classical sense but depends on the triplet excitation dose. At 20 K and for typical excitation doses, absolute values of the latter rate are of the order of 10-14cm3s-1 .

  3. Electronic Absolute Cartesian Autocollimator

    NASA Technical Reports Server (NTRS)

    Leviton, Douglas B.

    2006-01-01

    An electronic absolute Cartesian autocollimator performs the same basic optical function as does a conventional all-optical or a conventional electronic autocollimator but differs in the nature of its optical target and the manner in which the position of the image of the target is measured. The term absolute in the name of this apparatus reflects the nature of the position measurement, which, unlike in a conventional electronic autocollimator, is based absolutely on the position of the image rather than on an assumed proportionality between the position and the levels of processed analog electronic signals. The term Cartesian in the name of this apparatus reflects the nature of its optical target. Figure 1 depicts the electronic functional blocks of an electronic absolute Cartesian autocollimator along with its basic optical layout, which is the same as that of a conventional autocollimator. Referring first to the optical layout and functions only, this or any autocollimator is used to measure the compound angular deviation of a flat datum mirror with respect to the optical axis of the autocollimator itself. The optical components include an illuminated target, a beam splitter, an objective or collimating lens, and a viewer or detector (described in more detail below) at a viewing plane. The target and the viewing planes are focal planes of the lens. Target light reflected by the datum mirror is imaged on the viewing plane at unit magnification by the collimating lens. If the normal to the datum mirror is parallel to the optical axis of the autocollimator, then the target image is centered on the viewing plane. Any angular deviation of the normal from the optical axis manifests itself as a lateral displacement of the target image from the center. The magnitude of the displacement is proportional to the focal length and to the magnitude (assumed to be small) of the angular deviation. The direction of the displacement is perpendicular to the axis about which the

  4. Effect of light intensity on the degree of ammonia toxicity on PSII activity of Arthrospira platensis and Chlorella vulgaris.

    PubMed

    Markou, Giorgos; Muylaert, Koenraad

    2016-09-01

    Herein the effect of increasing light intensity on the degree of ammonia toxicity and its impact on the photosynthetic performance of Arthrospira and Chlorella was investigated using Chl fluorescence as a technique to characterize their photosystem II (PSII) activity. The results revealed that the increase of light intensity amplifies the ammonia toxicity on PSII. Chl fluorescence transients shown that at a given free ammonia (FA) concentration (100mg-N/L), the photochemistry potential decreased by increasing light intensity. The inhibition of the PSII was not reversible either by re-incubating the cells under dark or under decreased FA concentration. Moreover, the decrease of photochemical and non-photochemical quenching (NPQ) of fluorescence suggest that ammonia toxicity decreases the open available PSII centers, as well the inability of PSII to transfer the generated electrons beyond QA. The collapse of NPQ suggests that ammonia toxicity inhibits the photoprotection mechanism(s) and hence renders PSII more sensitive to photoinhibition. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Biocapture of CO2 by Different Microalgal-Based Technologies for Biogas Upgrading and Simultaneous Biogas Slurry Purification under Various Light Intensities and Photoperiods

    PubMed Central

    Guo, Pengfei; Zhang, Yuejin; Zhao, Yongjun

    2018-01-01

    Co-cultivation of microalgae and microbes for pollutant removal from sewage is considered as an effective wastewater treatment method. The aim of this study is to screen the optimal photoperiod, light intensity and microalgae co-cultivation method for simultaneously removing nutrients in biogas slurry and capturing CO2 in biogas. The microalgae–fungi pellets are deemed to be a viable option because of their high specific growth rate and nutrient and CO2 removal efficiency under the photoperiod of 14 h light:10 h dark. The order of both the biogas slurry purification and biogas upgrading is ranked the same, that is Chlorella vulgaris–Ganoderma lucidum > Chlorella vulgaris–activated sludge > Chlorella vulgaris under different light intensities. For all cultivation methods, the moderate light intensity of 450 μmol m−2 s−1 is regarded as the best choice. This research revealed that the control of photoperiod and light intensity can promote the biological treatment process of biogas slurry purification and biogas upgrading using microalgal-based technology. PMID:29543784

  6. Entrainment of oviposition in the fowl using bright and dim light cycles.

    PubMed

    Morris, T R; Bhatti, B M

    1978-05-01

    1. Nine short trial, involving 96 different treatments, were used to investigate the critical intensities and duration of bright and dim periods of lighting needed to entrain oviposition in cycles ranging from 21 to 30 h. 2. Entrainment was shown to depend upon the contrast between bright and dim lighting, and to be independent of the absolute light intensity. 3. A bright: dim ratio of 13:1 fully entrained oviposition in cycles of 25 h and 27 h. For 23-h and 28-h cycles a 30:1 ratio was required. Twenty-one-hour cycles required a ratio of 300:1 and with 30-h cycles a ratio of 1000:1 was needed to achieve full entrainment of oviposition. 4. In 24-h cycles, 1 h of bright lighting at 02.00 h was sufficient to override other environmental signals and cause eggs to be laid in the late evening, but a minimum bright period of 6 h was needed to cause full phase setting with 21-h cycles. 5. Circadian periodicity can easily be imposed on hens by providing a short exposure to bright light with a background of continuous dim light; but the signal must be increased (by providing a greater contrast between bright and dim lights and/or a longer period of bright lighting) to entrain oviposition when the cycle deviates markedly from the natural period of 24 h.

  7. Detection of internal structure by scattered light intensity: Application to kidney cell sorting

    NASA Technical Reports Server (NTRS)

    Goolsby, C. L.; Kunze, M. E.

    1985-01-01

    Scattered light measurements in flow cytometry were sucessfully used to distinguish cells on the basis of differing morphology and internal structure. Differences in scattered light patterns due to changes in internal structure would be expected to occur at large scattering angles. Practically, the results of these calculations suggest that in experimental situations an array of detectors would be useful. Although in general the detection of the scattered light intensity at several intervals within the 10 to 60 region would be sufficient, there are many examples where increased sensitivity could be acheived at other angles. The ability to measure at many different angular intervals would allow the experimenter to empirically select the optimum intervals for the varying conditions of cell size, N/C ratio, granule size and internal structure from sample to sample. The feasibility of making scattered light measurements at many different intervals in flow cytometry was demonstrated. The implementation of simplified versions of these techniques in conjunction with independant measurements of cell size could potentially improve the usefulness of flow cytometry in the study of the internal structure of cells.

  8. The Effects of Light Intensity, Casing Layers, and Layering Styles on Royal Sun Medicinal Mushroom, Agaricus brasiliensis (Higher Basidiomycetes) Cultivation in Turkey.

    PubMed

    Adanacioglu, Neşe; Boztok, Kaya; Akdeniz, Ramazan Cengiz

    2015-01-01

    The aim of this research is to evaluate the effects of light intensity, casing layers, and layering styles on the production of the culinary-medicinal mushroom Agaricus brasiliensis in Turkey. The experiments were designed in split-split plots and replicated twice. Three different light intensities-I1, 350 lux; I2, 450 lux; and I3, 750 lux-were used in main plots as environmental factors. A mixture of 4 different casing layers- peat (100%), peat-perlite (75%:25%), peat-clinoptilolite (75%:25%), and peat-perlite-clinoptilolite (60%:20%:20%)-were used at split plots and at split plots. S1, a flat, 3-cm casing layer; S2, a flat, 5-cm casing layer; and S3, casing soil ridges 10 cm wide × 4 cm high, 10 cm apart, were deposited on top of 1-cm overall soil casing layers. At the end of the harvest phase, the total yield was estimated per 100 kg of substrate. Biological efficiency (percentage) was determined from the fresh weight of the mushrooms and the dry weight of the compost at the end of the harvesting period. The highest total yield (7.2 kg/100 kg compost) and biological efficiency (27.63%) were achieved from I2 × peat-perlite-clinoptilolite × S2 treatment. Influence of light intensity, casing layer, layering style, and their interaction in treatments with color values (L*, a*, b*, chroma*, and hue*) also were examined. It has been shown that within color values, chroma* (saturation) values of mushroom caps were affected by light intensity, casing layer, and layering style treatments and light intensity × casing layer treatments and the brightness of mushroom caps tended to increase as light intensity increased.

  9. Absolute sensitivity calibration of an extreme ultraviolet spectrometer for tokamak measurements

    NASA Astrophysics Data System (ADS)

    Guirlet, R.; Schwob, J. L.; Meyer, O.; Vartanian, S.

    2017-01-01

    An extreme ultraviolet spectrometer installed on the Tore Supra tokamak has been calibrated in absolute units of brightness in the range 10-340 Å. This has been performed by means of a combination of techniques. The range 10-113 Å was absolutely calibrated by using an ultrasoft-X ray source emitting six spectral lines in this range. The calibration transfer to the range 113-182 Å was performed using the spectral line intensity branching ratio method. The range 182-340 Å was calibrated thanks to radiative-collisional modelling of spectral line intensity ratios. The maximum sensitivity of the spectrometer was found to lie around 100 Å. Around this wavelength, the sensitivity is fairly flat in a 80 Å wide interval. The spatial variations of sensitivity along the detector assembly were also measured. The observed trend is related to the quantum efficiency decrease as the angle of the incoming photon trajectories becomes more grazing.

  10. Chronic neuropathic facial pain after intense pulsed light hair removal. Clinical features and pharmacological management.

    PubMed

    Gay-Escoda, Cosme; Párraga-Manzol, Gabriela; Sánchez-Torres, Alba; Moreno-Arias, Gerardo

    2015-10-01

    Intense Pulsed Light (IPL) photodepilation is usually performed as a hair removal method. The treatment is recommended to be indicated by a physician, depending on each patient and on its characteristics. However, the use of laser devices by medical laypersons is frequent and it can suppose a risk of damage for the patients. Most side effects associated to IPL photodepilation are transient, minimal and disappear without sequelae. However, permanent side effects can occur. Some of the complications are laser related but many of them are caused by an operator error or mismanagement. In this work, we report a clinical case of a patient that developed a chronic neuropathic facial pain following IPL hair removal for unwanted hair in the upper lip. The specific diagnosis was painful post-traumatic trigeminal neuropathy, reference 13.1.2.3 according to the International Headache Society (IHS). Neuropathic facial pain, photodepilation, intense pulse light.

  11. Intense pulsed light and laser treatment regimen improves scar evolution after cleft lip repair surgery.

    PubMed

    Peng, Lihong; Tang, Shijie; Li, Qin

    2018-06-19

    To observe the effects of intense pulsed light (IPL) and lattice CO 2 laser treatment on scar evolution following cleft lip repair. Fifty cleft lip repair patients were enrolled in this study. Twenty-five patients used conventional approach with scar cream massage combined with silica gel products after operation. While other 25 patients which received IPL and lattice CO 2 laser treatments. The treatments commenced 1 week after removal of stitches and observation of scar hyperplasia. Scar evolution was evaluated with the Vancouver scar scale (VSS) by postoperative photographs. Relative to the conventional approach, the laser treatments showed improved scar softening and flattening. These differences were reflected in the groups' significantly different VSS scores. Intense pulsed light combined with lattice CO 2 laser treatment can improve cleft lip surgery scar pliability and appearance, while alleviating children from having to endure the pain of scar massage. © 2018 Wiley Periodicals, Inc.

  12. Dynamic frequency-domain interferometer for absolute distance measurements with high resolution

    NASA Astrophysics Data System (ADS)

    Weng, Jidong; Liu, Shenggang; Ma, Heli; Tao, Tianjiong; Wang, Xiang; Liu, Cangli; Tan, Hua

    2014-11-01

    A unique dynamic frequency-domain interferometer for absolute distance measurement has been developed recently. This paper presents the working principle of the new interferometric system, which uses a photonic crystal fiber to transmit the wide-spectrum light beams and a high-speed streak camera or frame camera to record the interference stripes. Preliminary measurements of harmonic vibrations of a speaker, driven by a radio, and the changes in the tip clearance of a rotating gear wheel show that this new type of interferometer has the ability to perform absolute distance measurements both with high time- and distance-resolution.

  13. Light intensity distribution optimization for tunnel lamps in different zones of a long tunnel.

    PubMed

    Lai, Wei; Liu, Xianming; Chen, Weimin; Lei, Xiaohua; Cheng, Xingfu

    2014-09-22

    The light distributions in different tunnel zones have different requirements in order to meet the driver's visual system. In this paper, the light intensity distributions of tunnel lamps in different zones of a long tunnel are optimized separately. A common nonlinear optimization approach is proposed to minimize the consuming power as well as satisfy the luminance and glare requirements both on the road surface and on the wall set by International Commission on Illumination (CIE). Compared with that of the reported linear optimization method, the optimization model can save energy from 11% to 57.6% under the same installation conditions.

  14. Teaching Absolute Value Meaningfully

    ERIC Educational Resources Information Center

    Wade, Angela

    2012-01-01

    What is the meaning of absolute value? And why do teachers teach students how to solve absolute value equations? Absolute value is a concept introduced in first-year algebra and then reinforced in later courses. Various authors have suggested instructional methods for teaching absolute value to high school students (Wei 2005; Stallings-Roberts…

  15. The effects of light emitting diode therapy following high intensity exercise.

    PubMed

    Denis, Romain; O'Brien, Christopher; Delahunt, Eamonn

    2013-05-01

    To determine the effects of light emitting diode therapy (LEDT) irradiation on blood lactate concentration ([La]) clearance, peak power output and fatigue index (FI) following high intensity fatiguing exercise. Single-blinded randomised cross-over placebo controlled trial. University College Dublin, Institute for Sport and Health, Human performance laboratory. Eighteen healthy male athletes were recruited from field-based sports (including soccer, hockey and rugby union) and participated in the present study. Dependent variables were the peak power output elicited during the Wingate Anaerobic Test (WAnT), FI and [La] before and after each exercise. WAnT performance was measured prior to high intensity fatiguing exercise (Yo-Yo IR2), prior to LEDT or placebo, and following LEDT or placebo. [La] was measured at baseline, immediately after the Yo-Yo IR2, and in the 3rd, 9th, and 15th min following LEDT or placebo condition. No significant group by treatment interactions were observed for any outcome measures (P > 0.05). We conclude that LEDT irradiation applied following high intensity exercise was not effective and has no immediate effect on [La] clearance, peak power and FI, and thus has no significant effect on muscle recovery in athletes at the intensity and irradiation parameters used in the present study. Further research using different parameters is required to determine how LEDT may contribute to post-exercise recovery. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Effect of Light Intensity on the Relative Dominance of Toxigenic and Nontoxigenic Strains of Microcystis aeruginosa ▿

    PubMed Central

    LeBlanc Renaud, Susan; Pick, Frances R.; Fortin, Nathalie

    2011-01-01

    In aquatic ecosystems, the factors that regulate the dominance of toxin-producing cyanobacteria over non-toxin-producing strains of the same species are largely unknown. One possible hypothesis is that limiting resources lead to the dominance of the latter because of the metabolic costs associated with toxin production. In this study, we tested the effect of light intensity on the performance of a microcystin-producing strain of Microcystis aeruginosa (UTCC 300) when grown in mixed cultures with non-microcystin-producing strains with similar intrinsic growth rates (UTCC 632 and UTCC 633). The endpoints measured included culture growth rates, microcystin concentrations and composition, and mcyD gene copy numbers determined using quantitative PCR (Q-PCR). In contrast to the predicted results, under conditions of low light intensity (20 μmol·m−2·s−1), the toxigenic strain became dominant in both of the mixed cultures based on gene copy numbers and microcystin concentrations. When grown under conditions of high light intensity (80 μmol·m−2·s−1), the toxigenic strain still appeared to dominate over nontoxigenic strain UTCC 632 but less so over strain UTCC 633. Microcystins may not be so costly to produce that toxigenic cyanobacteria are at a disadvantage in competition for limiting resources. PMID:21841026

  17. Optoelectrofluidic field separation based on light-intensity gradients

    PubMed Central

    Lee, Sanghyun; Park, Hyun Jin; Yoon, Jin Sung; Kang, Kwan Hyoung

    2010-01-01

    Optoelectrofluidic field separation (OEFS) of particles under light -intensity gradient (LIG) is reported, where the LIG illumination on the photoconductive layer converts the short-ranged dielectrophoresis (DEP) force to the long-ranged one. The long-ranged DEP force can compete with the hydrodynamic force by alternating current electro-osmosis (ACEO) over the entire illumination area for realizing effective field separation of particles. In the OEFS system, the codirectional illumination and observation induce the levitation effect, compensating the attenuation of the DEP force under LIG illumination by slightly floating particles from the surface. Results of the field separation and concentration of diverse particle pairs (0.82–16 μm) are well demonstrated, and conditions determining the critical radius and effective particle manipulation are discussed. The OEFS with codirectional LIG strategy could be a promising particle manipulation method in many applications where a rapid manipulation of biological cells and particles over the entire working area are of interest. PMID:20697461

  18. Optoelectrofluidic field separation based on light-intensity gradients.

    PubMed

    Lee, Sanghyun; Park, Hyun Jin; Yoon, Jin Sung; Kang, Kwan Hyoung

    2010-07-14

    Optoelectrofluidic field separation (OEFS) of particles under light -intensity gradient (LIG) is reported, where the LIG illumination on the photoconductive layer converts the short-ranged dielectrophoresis (DEP) force to the long-ranged one. The long-ranged DEP force can compete with the hydrodynamic force by alternating current electro-osmosis (ACEO) over the entire illumination area for realizing effective field separation of particles. In the OEFS system, the codirectional illumination and observation induce the levitation effect, compensating the attenuation of the DEP force under LIG illumination by slightly floating particles from the surface. Results of the field separation and concentration of diverse particle pairs (0.82-16 mum) are well demonstrated, and conditions determining the critical radius and effective particle manipulation are discussed. The OEFS with codirectional LIG strategy could be a promising particle manipulation method in many applications where a rapid manipulation of biological cells and particles over the entire working area are of interest.

  19. Effect of varying light intensity on welfare indices of broiler chickens grown to heavy weights

    USDA-ARS?s Scientific Manuscript database

    The effects of varying light-intensity on ocular, immue, fear, and leg health of broiler chickens grown to heavy weights under environmentally controlled conditions were evaluated. Four identical trials were conducted with two replications per trial. In each trial, 600 Ross 308 chicks were randomly ...

  20. Relationship between 3-Methyl-2,4-nonanedione Concentration and Intensity of Light-induced Off-odor in Soy Bean Oil.

    PubMed

    Sano, Takashi; Iwahashi, Maiko; Imagi, Jun; Sato, Toshiro; Yamashita, Toshiyuki; Fukusaki, Eiichiro; Bamba, Takeshi

    2016-05-01

    A beany and green off-odor is developed in soy bean oil (SBO) under light-induced oxidative conditions. 3-Methyl-2,4-nonanedione (3-MND) was inferred as the compound responsible for the off-odor. In this study, we designed a simple quantification method for 3-MND in SBO, and evaluated the relationship between the 3-MND concentration and the intensity of the off-odor. 3-MND was analyzed by GC/MS with a thermal desorption unit system. By our method, the 3-MND concentration was found to increase with storage days and the SBO content under light exposure, and there was a high correlation between the measured 3-MND concentration and the intensity of the light-induced off-odor in SBO (R = 0.9586).

  1. Auger Up-Conversion of Low-Intensity Infrared Light in Engineered Quantum Dots

    DOE PAGES

    Makarov, Nikolay S.; Lin, Qianglu; Pietryga, Jeffrey M.; ...

    2016-11-29

    One source of efficiency losses in photovoltaic cells is their transparency toward solar photons with energies below the band gap of the absorbing layer. This loss can be reduced using a process of up-conversion whereby two or more sub-band-gap photons generate a single above-gap exciton. Traditional approaches to up-conversion, such as nonlinear two-photon absorption (2PA) or triplet fusion, suffer from low efficiency at solar light intensities, a narrow absorption bandwidth, nonoptimal absorption energies, and difficulties for implementing in practical devices. We show that these deficiencies can be alleviated using the effect of Auger up-conversion in thick-shell PbSe/CdSe quantum dots. Thismore » process relies on Auger recombination whereby two low-energy, core-based excitons are converted into a single higher-energy, shell-based exciton. When compared to their monocomponent counterparts, the tailored PbSe/CdSe heterostructures feature enhanced absorption cross-sections, a higher efficiency of the “productive” Auger pathway involving re-excitation of a hole, and longer lifetimes of both core- and shell-localized excitons. These features lead to effective up-conversion cross-sections that are more than 6 orders of magnitude higher than for standard nonlinear 2PA, which allows for efficient up-conversion of continuous wave infrared light at intensities as low as a few watts per square centimeter.« less

  2. From Intensity Profile to Surface Normal: Photometric Stereo for Unknown Light Sources and Isotropic Reflectances.

    PubMed

    Lu, Feng; Matsushita, Yasuyuki; Sato, Imari; Okabe, Takahiro; Sato, Yoichi

    2015-10-01

    We propose an uncalibrated photometric stereo method that works with general and unknown isotropic reflectances. Our method uses a pixel intensity profile, which is a sequence of radiance intensities recorded at a pixel under unknown varying directional illumination. We show that for general isotropic materials and uniformly distributed light directions, the geodesic distance between intensity profiles is linearly related to the angular difference of their corresponding surface normals, and that the intensity distribution of the intensity profile reveals reflectance properties. Based on these observations, we develop two methods for surface normal estimation; one for a general setting that uses only the recorded intensity profiles, the other for the case where a BRDF database is available while the exact BRDF of the target scene is still unknown. Quantitative and qualitative evaluations are conducted using both synthetic and real-world scenes, which show the state-of-the-art accuracy of smaller than 10 degree without using reference data and 5 degree with reference data for all 100 materials in MERL database.

  3. Experimental evaluation of models for predicting Cherenkov light intensities from short-cooled nuclear fuel assemblies

    NASA Astrophysics Data System (ADS)

    Branger, E.; Grape, S.; Jansson, P.; Jacobsson Svärd, S.

    2018-02-01

    The Digital Cherenkov Viewing Device (DCVD) is a tool used by nuclear safeguards inspectors to verify irradiated nuclear fuel assemblies in wet storage based on the recording of Cherenkov light produced by the assemblies. One type of verification involves comparing the measured light intensity from an assembly with a predicted intensity, based on assembly declarations. Crucial for such analyses is the performance of the prediction model used, and recently new modelling methods have been introduced to allow for enhanced prediction capabilities by taking the irradiation history into account, and by including the cross-talk radiation from neighbouring assemblies in the predictions. In this work, the performance of three models for Cherenkov-light intensity prediction is evaluated by applying them to a set of short-cooled PWR 17x17 assemblies for which experimental DCVD measurements and operator-declared irradiation data was available; (1) a two-parameter model, based on total burnup and cooling time, previously used by the safeguards inspectors, (2) a newly introduced gamma-spectrum-based model, which incorporates cycle-wise burnup histories, and (3) the latter gamma-spectrum-based model with the addition to account for contributions from neighbouring assemblies. The results show that the two gamma-spectrum-based models provide significantly higher precision for the measured inventory compared to the two-parameter model, lowering the standard deviation between relative measured and predicted intensities from 15.2 % to 8.1 % respectively 7.8 %. The results show some systematic differences between assemblies of different designs (produced by different manufacturers) in spite of their similar PWR 17x17 geometries, and possible ways are discussed to address such differences, which may allow for even higher prediction capabilities. Still, it is concluded that the gamma-spectrum-based models enable confident verification of the fuel assembly inventory at the currently used

  4. Chronic neuropathic facial pain after intense pulsed light hair removal. Clinical features and pharmacological management

    PubMed Central

    Párraga-Manzol, Gabriela; Sánchez-Torres, Alba; Moreno-Arias, Gerardo

    2015-01-01

    Intense Pulsed Light (IPL) photodepilation is usually performed as a hair removal method. The treatment is recommended to be indicated by a physician, depending on each patient and on its characteristics. However, the use of laser devices by medical laypersons is frequent and it can suppose a risk of damage for the patients. Most side effects associated to IPL photodepilation are transient, minimal and disappear without sequelae. However, permanent side effects can occur. Some of the complications are laser related but many of them are caused by an operator error or mismanagement. In this work, we report a clinical case of a patient that developed a chronic neuropathic facial pain following IPL hair removal for unwanted hair in the upper lip. The specific diagnosis was painful post-traumatic trigeminal neuropathy, reference 13.1.2.3 according to the International Headache Society (IHS). Key words:Neuropathic facial pain, photodepilation, intense pulse light. PMID:26535105

  5. Calculating Absolute Transition Probabilities for Deformed Nuclei in the Rare-Earth Region

    NASA Astrophysics Data System (ADS)

    Stratman, Anne; Casarella, Clark; Aprahamian, Ani

    2017-09-01

    Absolute transition probabilities are the cornerstone of understanding nuclear structure physics in comparison to nuclear models. We have developed a code to calculate absolute transition probabilities from measured lifetimes, using a Python script and a Mathematica notebook. Both of these methods take pertinent quantities such as the lifetime of a given state, the energy and intensity of the emitted gamma ray, and the multipolarities of the transitions to calculate the appropriate B(E1), B(E2), B(M1) or in general, any B(σλ) values. The program allows for the inclusion of mixing ratios of different multipolarities and the electron conversion of gamma-rays to correct for their intensities, and yields results in absolute units or results normalized to Weisskopf units. The code has been tested against available data in a wide range of nuclei from the rare earth region (28 in total), including 146-154Sm, 154-160Gd, 158-164Dy, 162-170Er, 168-176Yb, and 174-182Hf. It will be available from the Notre Dame Nuclear Science Laboratory webpage for use by the community. This work was supported by the University of Notre Dame College of Science, and by the National Science Foundation, under Contract PHY-1419765.

  6. High-Speed Terahertz Waveform Measurement for Intense Terahertz Light Using 100-kHz Yb-Doped Fiber Laser.

    PubMed

    Tsubouchi, Masaaki; Nagashima, Keisuke

    2018-06-14

    We demonstrate a high-speed terahertz (THz) waveform measurement system for intense THz light with a scan rate of 100 Hz. To realize the high scan rate, a loudspeaker vibrating at 50 Hz is employed to scan the delay time between THz light and electro-optic sampling light. Because the fast scan system requires a high data sampling rate, we develop an Yb-doped fiber laser with a repetition rate of 100 kHz optimized for effective THz light generation with the output electric field of 1 kV/cm. The present system drastically reduces the measurement time of the THz waveform from several minutes to 10 ms.

  7. Pixel-by-pixel absolute phase retrieval using three phase-shifted fringe patterns without markers

    NASA Astrophysics Data System (ADS)

    Jiang, Chufan; Li, Beiwen; Zhang, Song

    2017-04-01

    This paper presents a method that can recover absolute phase pixel by pixel without embedding markers on three phase-shifted fringe patterns, acquiring additional images, or introducing additional hardware component(s). The proposed three-dimensional (3D) absolute shape measurement technique includes the following major steps: (1) segment the measured object into different regions using rough priori knowledge of surface geometry; (2) artificially create phase maps at different z planes using geometric constraints of structured light system; (3) unwrap the phase pixel by pixel for each region by properly referring to the artificially created phase map; and (4) merge unwrapped phases from all regions into a complete absolute phase map for 3D reconstruction. We demonstrate that conventional three-step phase-shifted fringe patterns can be used to create absolute phase map pixel by pixel even for large depth range objects. We have successfully implemented our proposed computational framework to achieve absolute 3D shape measurement at 40 Hz.

  8. Influence of Light Intensity and Photoperiod on the Seed Germination of Four Rhododendron Species in Taiwan.

    PubMed

    Lin, Lei-Chen; Wang, Chang-Sheng

    2017-01-01

    There are 15 native Rhododendron species in Taiwan, among which 11 species are endemic and compose 73% of these native species. Although researchers predominantly use cuttings to propagate Rhododendron shrubs, there are no studies on the seed germination of Rhododendron species. The objective of this study was to evaluate the seed germination of four Rhododendron species in Taiwan under different light intensities and photoperiods. Two experiments on the seed germination percentage of R. breviperulatum, R. kanehirai, R. ovatum and R. simsii were conducted in this study. The first experiment was to identify the seed germination percentage of these four Rhododendron species using different light intensities (0, 700, 1400 and 3200 lux). The second experiment was to clarify the seed germination percentage of these four Rhododendron species using different photoperiods (0, 1, 4 and 16 h). All statistical analyses were performed using Statistical Package for the Social Science (SPSS12.0) for Windows software program. The data were analyzed using Tukey's multiple range test at the p<0.05 significance level. After 30 days, no seed germination occurred in darkness. The highest average seed germination percentages were all observed at 700 lux: R. breviperulatum (83.3%), R. kanehirai (68.9%), R. ovatum (85.6%) and R. simsii (92.2%). The highest average germination percentages of seeds were observed in R. breviperulatum at 16 h (83.3%), R. kanehirai at 1 h (60.0%), R. ovatum at 16 h (84.4%) and R. simsii at 16 h (85.6%). According to the results, these four Rhododendron species required light for germination. There were significant differences (p<0.05) in the seed germination of these four Rhododendron species for light intensity greater than 700 lux. Similar results were observed with photoperiods. The seed germination percentage of R. breviperulatum, R. ovatum and R. simsii increased with increasing photoperiod.

  9. Phenotypic plasticity of Neonotonia wightii and Pueraria phaseoloides grown under different light intensities.

    PubMed

    Santos, Leonardo D T; Da Cruz, Leandro R; Dos Santos, Samuel A; Sant'anna-Santos, Bruno F; Dos Santos, Izabela T; De Oliveira, Ariane M; Barros, Rodrigo E; Santos, Márcia V; Faria, Rodrigo M

    2015-03-01

    Plants have the ability to undergo morphophysiological changes based on availability of light. The present study evaluated biomass accumulation, leaf morphoanatomy and physiology of Neonotonia wightii and Pueraria phaseoloides grown in full sunlight, as well as in 30% and 50% shade. Two assays were performed, one for each species, using a randomized block design with 10 replicates. A higher accumulation of fresh mass in the shoot of the plants was observed for both species under cultivation in 50% shade, while no differences were detected between the full sunlight and 30% shade. N. wightii and P. phaseoloides showed increase in area and reduction in thickness leaf when cultivated in 50% shade. There were no changes in photosynthetic rate, stomatal conductance, water use efficiency and evapotranspiration of P. phaseoloides plants because growth environment. However, the shade treatments caused alterations in physiological parameters of N. wightii. In both species, structural changes in the mesophyll occurred depending on the availability of light; however, the amount of leaf blade tissue remained unaltered. Despite the influence of light intensity variation on the morphophysiological plasticity of N. wightii and P. phaseoloides, no effects on biomass accumulation were observed in response to light.

  10. Effect of blue LED light intensity on carotenoid accumulation in citrus juice sacs.

    PubMed

    Zhang, Lancui; Ma, Gang; Yamawaki, Kazuki; Ikoma, Yoshinori; Matsumoto, Hikaru; Yoshioka, Terutaka; Ohta, Satoshi; Kato, Masaya

    2015-09-01

    In the present study, the effects of blue LED light intensity on carotenoid accumulation and expression of genes related to carotenoid biosynthesis were investigated in the juice sacs of Satsuma mandarin (Citrus unshiu Marc.) and Valencia orange (Citrus sinensis Osbeck) in vitro. The results showed that 100 μmol m(-2)s(-1) blue LED light (100B) was effective for increasing carotenoid content, especially β-cryptoxanthin, in Satsuma mandarin after cultured in vitro for four weeks. In Valencia orange, in contrast, 50 μmol m(-2)s(-1) blue LED light (50B) treatment was effective for inducing carotenoid accumulation through increasing the contents of two major carotenoids, all-trans-violaxanthin and 9-cis-violaxanthin. In addition, gene expression results showed that the simultaneous increases in the expression of genes (CitPSY, CitPDS, CitZDS, CitLCYb2, and CitHYb) involved in producing β,β-xanthophylls were well consistent with the accumulation of β-cryptoxanthin in Satsuma mandarin under 100B, and violaxanthin in Valencia orange under 50B. The results presented herein contribute to further elucidating the regulatory mechanism of carotenoid accumulation by blue LED light. Copyright © 2015 Elsevier GmbH. All rights reserved.

  11. Absolute Rovibrational Intensities, Self-Broadening and Self-Shift Coefficients for the X(sup 1) Sigma(+) V=3 (left arrow) V=0 Band (C-12)(O-16)

    NASA Technical Reports Server (NTRS)

    Chackerian, Charles, Jr.; Freedman, R.; Giver, L. P.; Brown, L. R.

    2001-01-01

    The rotationless transition moment squared for the x(sup 1) sigma (sup +) v=3 (left arrow) v=0 band of CO is measured to be the absolute value of R (sub 3-0) squared = 1.7127(25)x 10(exp -7) Debye squared. This value is about 8.6 percent smaller than the value assumed for HITRAN 2000. The Herman-Wallis intensity factor of this band is F=1+0.01168(11)m+0.0001065(79)m squared. The determination of self-broadening coefficients is improved with the inclusion of line narrowing; self-shifts are also reported.

  12. Understanding the molecular mechanisms underlying the effects of light intensity on flavonoid production by RNA-seq analysis in Epimedium pseudowushanense B.L.Guo.

    PubMed

    Pan, Junqian; Chen, Haimei; Guo, Baolin; Liu, Chang

    2017-01-01

    Epimedium pseudowushanense B.L.Guo, a light-demanding shade herb, is used in traditional medicine to increase libido and strengthen muscles and bones. The recognition of the health benefits of Epimedium has increased its market demand. However, its resource recycling rate is low and environmentally dependent. Furthermore, its natural sources are endangered, further increasing prices. Commercial culture can address resource constraints of it.Understanding the effects of environmental factors on the production of its active components would improve the technology for cultivation and germplasm conservation. Here, we studied the effects of light intensities on the flavonoid production and revealed the molecular mechanism using RNA-seq analysis. Plants were exposed to five levels of light intensity through the periods of germination to flowering, the flavonoid contents were measured using HPLC. Quantification of epimedin A, epimedin B, epimedin C, and icariin showed that the flavonoid contents varied with different light intensity levels. And the largest amount of epimedin C was produced at light intensity level 4 (I4). Next, the leaves under the treatment of three light intensity levels ("L", "M" and "H") with the largest differences in the flavonoid content, were subjected to RNA-seq analysis. Transcriptome reconstruction identified 43,657 unigenes. All unigene sequences were annotated by searching against the Nr, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. In total, 4008, 5260, and 3591 significant differentially expressed genes (DEGs) were identified between the groups L vs. M, M vs. H and L vs. H. Particularly, twenty-one full-length genes involved in flavonoid biosynthesis were identified. The expression levels of the flavonol synthase, chalcone synthase genes were strongly associated with light-induced flavonoid abundance with the highest expression levels found in the H group. Furthermore, 65 transcription factors, including 31

  13. 33 CFR 149.565 - What are the required characteristics and intensity of lights on buoys used to define traffic lanes?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... define traffic lanes? (a) The buoy's light color that defines the lateral boundaries of a traffic lane must comply with the buoy color schemes in § 62.25 of this chapter. (b) The buoy light may be fixed or... characteristics and intensity of lights on buoys used to define traffic lanes? 149.565 Section 149.565 Navigation...

  14. 33 CFR 149.565 - What are the required characteristics and intensity of lights on buoys used to define traffic lanes?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... define traffic lanes? (a) The buoy's light color that defines the lateral boundaries of a traffic lane must comply with the buoy color schemes in § 62.25 of this chapter. (b) The buoy light may be fixed or... characteristics and intensity of lights on buoys used to define traffic lanes? 149.565 Section 149.565 Navigation...

  15. 33 CFR 149.565 - What are the required characteristics and intensity of lights on buoys used to define traffic lanes?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... define traffic lanes? (a) The buoy's light color that defines the lateral boundaries of a traffic lane must comply with the buoy color schemes in § 62.25 of this chapter. (b) The buoy light may be fixed or... characteristics and intensity of lights on buoys used to define traffic lanes? 149.565 Section 149.565 Navigation...

  16. 33 CFR 149.565 - What are the required characteristics and intensity of lights on buoys used to define traffic lanes?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... define traffic lanes? (a) The buoy's light color that defines the lateral boundaries of a traffic lane must comply with the buoy color schemes in § 62.25 of this chapter. (b) The buoy light may be fixed or... characteristics and intensity of lights on buoys used to define traffic lanes? 149.565 Section 149.565 Navigation...

  17. 33 CFR 149.565 - What are the required characteristics and intensity of lights on buoys used to define traffic lanes?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... define traffic lanes? (a) The buoy's light color that defines the lateral boundaries of a traffic lane must comply with the buoy color schemes in § 62.25 of this chapter. (b) The buoy light may be fixed or... characteristics and intensity of lights on buoys used to define traffic lanes? 149.565 Section 149.565 Navigation...

  18. Easy Absolute Values? Absolutely

    ERIC Educational Resources Information Center

    Taylor, Sharon E.; Mittag, Kathleen Cage

    2015-01-01

    The authors teach a problem-solving course for preservice middle-grades education majors that includes concepts dealing with absolute-value computations, equations, and inequalities. Many of these students like mathematics and plan to teach it, so they are adept at symbolic manipulations. Getting them to think differently about a concept that they…

  19. Athermal fiber laser for the SWARM absolute scalar magnetometer

    NASA Astrophysics Data System (ADS)

    Fourcault, W.; Léger, J.-M.; Costes, V.; Fratter, I.; Mondin, L.

    2017-11-01

    The Absolute Scalar Magnetometer (ASM) developed by CEA-LETI/CNES is an optically pumped 4He magnetic field sensor based on the Zeeman effect and an electronic magnetic resonance whose effects are amplified by a laser pumping process [1-2]. Consequently, the role of the laser is to pump the 4He atoms at the D0 transition as well as to allow the magnetic resonance signal detection. The ASM will be the scalar magnetic reference instrument of the three ESA Swarm satellites to be launched in 2012 in order to carry out the best ever survey of the Earth magnetic field and its temporal evolution. The sensitivity and accuracy of this magnetometer based on 4He optical pumping depend directly on the characteristics of its light source, which is the key sub-system of the sensor. We describe in this paper the selected fiber laser architecture and its wavelength stabilization scheme. Its main performance in terms of spectral emission, optical power at 1083 nm and intensity noise characteristics in the frequency bands used for the operation of the magnetometer, are then presented. Environmental testing results (thermal vacuum cycling, vibrations, shocks and ageing) are also reported at the end of this paper.

  20. Spectral effects of light-emitting diodes on plant growth and development: The importance of green and blue light

    NASA Astrophysics Data System (ADS)

    Cope, K. R.; Bugbee, B.

    2011-12-01

    Light-emitting diodes (LEDs) are an emerging technology for plant growth lighting. Due to their narrow spectral output, colored LEDs provide many options for studying the spectral effects of light on plants. Early on, efficient red LEDs were the primary focus of photobiological research; however, subsequent studies have shown that normal plant growth and development cannot be achieved under red light without blue light supplementation. More recent studies have shown that red and blue (RB) LEDs supplemented with green light increase plant dry mass. This is because green light transmits more effectively through the leaf canopy than red and blue light, thus illuminating lower plant leaves and increasing whole-plant photosynthesis. Red, green and blue (RGB) light can be provided by either a conventional white light source (such as fluorescent lights), a combination of RGB LEDs, or from recently developed white LEDs. White LEDs exceed the efficiency of fluorescent lights and have a comparable broad spectrum. As such, they have the potential to replace fluorescent lighting for growth-chamber-based crop production both on Earth and in space. Here we report the results of studies on the effects of three white LED types (warm, neutral and cool) on plant growth and development compared to combinations of RB and RGB LEDs. Plants were grown under two constant light intensities (200 and 500 μmol m-2 s-1). Temperature, environmental conditions and root-zone environment were uniformly maintained across treatments. Phytochrome photoequilbria and red/far-red ratios were similar among treatments and were comparable to conventional fluorescent lights. Blue light had a significant effect on both plant growth (dry mass gain) and development (dry mass partitioning). An increase in the absolute amount (μmol m-2 s-1) of blue light from 0-80 μmol m-2 s-1 resulted in a decrease in stem elongation, independent of the light intensity. However, an increase in the relative amount (%) of blue

  1. Lighting intensity of the soilsurface and restocking of oak groves

    NASA Astrophysics Data System (ADS)

    Slepykh, Victor; Zubko, Anna; Povolotckaia, Nina

    2016-04-01

    Oak groves of Caucasian Mineral Vody region (CMVR) possess a high ecological and balneological potential which defines the significance of their preservation and reproduction [1]. The role assessment of lighting intensity on renewal of oak groves was carried out on four trial squares (ts) in natural sixty-seven years old forest stand with prevalence of English oak (Quercus robur L.) with unimodal sity (type of the habitat - C1). The illumination was measured at the grass level by the universal measuring instrument of meteoparameters ATT-9508 with an illumination sensor of ATA-1591. The assessment of reforestation was carried out according to the established standards [2]. In the winter of 2005 there was conducted a selecting cutting cabin of the forest stand according to a local method on ts2 with intensity 30%, on ts4 - 50% after which the illumination on the soil surface in relation to illumination of an open place in the summer of 2005 increased from 4.9% to 33.9% on ts2, and from 5.9% to 24.4% on ts4. But by 2014 the illumination decreased till 3.0% on ts2, till 5.4% on ts4 because of an intensive soil grassing down. The control was carried out by ts1 and ts3 on which from 2005 to 2014 the illumination of the soil surface decreased from 4 to 2% as a result of the development of all storeys. As a result due to an intensive soil grassing-down, the total quantity of young oak trees decreased from 2005 to 2014 from 25.6 thousand pcs/ha to 5.9 thousand pcs/ha on ts2; on from 17.3 thousand pcs/ha to 4.0 thousand pcs/ha on ts4. At the same time the total quantity of young oak trees on control squares increased respectively for 1.4% (from 18.8 thousand pcs/ha to 19.1 thousand pcs/ha) on ts1, for 38.7% (from 25.2 thousand pcs/ha to 41.1 thousand pcs/ha). The experiment showed that small young oak trees perishes in the first years of their life from a lack of light and competition from grasland vegetation without providing successful reforestation. Conclusion. So it is

  2. Selective detection of Escherichia coli by imaging of the light intensity transmitted through an optical disk

    NASA Astrophysics Data System (ADS)

    Shiramizu, Hideyuki; Kuroda, Chiaki; Ohki, Yoshimichi; Shima, Takayuki; Wang, Xiaomin; Fujimaki, Makoto

    2018-03-01

    We have developed an optical disk system for imaging transmitted light from Escherichia coli dispersed on an optical disk. When E. coli was stained using Bismarck brown, the transmittance was found to decrease in images obtained at λ = 405 nm. The results indicate that transmittance imaging is suitable for finding the difference in light intensity between stained and unstained E. coli, whereas the reflectance images were scarcely changed by staining. Therefore, E. coli can be selectively discriminated from abiotic contaminants using transmittance imaging.

  3. Size variability of the unit building block of peripheral light-harvesting antennas as a strategy for effective functioning of antennas of variable size that is controlled in vivo by light intensity.

    PubMed

    Taisova, A S; Yakovlev, A G; Fetisova, Z G

    2014-03-01

    This work continuous a series of studies devoted to discovering principles of organization of natural antennas in photosynthetic microorganisms that generate in vivo large and highly effective light-harvesting structures. The largest antenna is observed in green photosynthesizing bacteria, which are able to grow over a wide range of light intensities and adapt to low intensities by increasing of size of peripheral BChl c/d/e antenna. However, increasing antenna size must inevitably cause structural changes needed to maintain high efficiency of its functioning. Our model calculations have demonstrated that aggregation of the light-harvesting antenna pigments represents one of the universal structural factors that optimize functioning of any antenna and manage antenna efficiency. If the degree of aggregation of antenna pigments is a variable parameter, then efficiency of the antenna increases with increasing size of a single aggregate of the antenna. This means that change in degree of pigment aggregation controlled by light-harvesting antenna size is biologically expedient. We showed in our previous work on the oligomeric chlorosomal BChl c superantenna of green bacteria of the Chloroflexaceae family that this principle of optimization of variable antenna structure, whose size is controlled by light intensity during growth of bacteria, is actually realized in vivo. Studies of this phenomenon are continued in the present work, expanding the number of studied biological materials and investigating optical linear and nonlinear spectra of chlorosomes having different structures. We show for oligomeric chlorosomal superantennas of green bacteria (from two different families, Chloroflexaceae and Oscillochloridaceae) that a single BChl c aggregate is of small size, and the degree of BChl c aggregation is a variable parameter, which is controlled by the size of the entire BChl c superantenna, and the latter, in turn, is controlled by light intensity in the course of cell

  4. Increased fibroblast proliferation and activity after applying intense pulsed light 800-1200 nm.

    PubMed

    Cuerda-Galindo, E; Díaz-Gil, G; Palomar-Gallego, M A; Linares-GarcíaValdecasas, R

    2015-03-01

    Light devices emitting near infrared have been shown to be highly effective for the skin rejuvenation but biochemical and molecular mechanism or optimum dose treatment are not well-known. In our study we try to elucidate why systems emitting near infrared produce skin improvement such as fibroblasts proliferation, increase in gene expression or extracellular matrix (ECM) protein production. 1BR3G human skin fibroblasts were used to test the effects of an intense pulsed light device emitting with an 800-1200 nm filter (MiniSilk FT manufactured by Deka(®)). In our protocol, fibroblasts were irradiated twice successively with a 10 Hz frequency, with a total fluence up to 60 J/cm(2) for 15s each pass. After incubating for 48 h, fibroblasts were harvested from the culture plates to test cell proliferation by flow cytometer. To determine changes in gene expression (mRNA levels for collagen types I and III and metalloproteinase 1 (MMP-1)) and protein production (hyaluronic acid, versican and decorin) tests were performed after irradiation. After 48 h irradiation, 1BR3G human skin fibroblasts were observed to proliferate at a fast rate. The study of ECM macromolecules production using ELISA showed an increase of hyaluronic acid and versican production but no changes were observed for decorin. With RT-PCR assays, an increase in mRNA for collagen type I, type III and MMP-1 were observed. Intense pulsed light emitting near infrared applied in vitro cultured cells increases fibroblasts proliferation and activity, which can be a possible mechanism of action for these devices in aging skin treatment. Copyright © 2014 Elsevier GmbH. All rights reserved.

  5. Effects of guidelines implementation in a surgical intensive care unit to control nighttime light and noise levels.

    PubMed

    Walder, B; Francioli, D; Meyer, J J; Lançon, M; Romand, J A

    2000-07-01

    Because of around-the-clock activities, environmental noise and light are among the many causes of sleep disturbance in an intensive care unit (ICU). The implementation of guidelines may potentially change behavior rules and improve sleep quality. A prospective interventional study, observing the effects of simple nighttime guidelines on light and noise levels in an ICU. A modern surgical ICU, subdivided into six identical three-bed rooms. Critically ill adult patients. Between two observation periods, five guidelines were implemented to decrease both light and noise during the night shift in the patient's room. Light levels and noise levels were obtained using a luxmeter and a sound level meter [A-weighted decibels (dB) scale] and were monitored continuously from 11 pm to 5 am both before (period P1) and after (period P2) the implementation of guidelines. Similar patient's gravity and nursing workload scores were observed between P1 and P2. A low mean (<5 Lux) and maximal light level were measured during both P1 and P2. The implementation of guidelines lowered mean light disturbance intensity with a greater variability of light during P2. All noise levels were high and corresponded more to a quiet office for noise level equivalents and to a busy restaurant for peak noise levels during both P1 and P2. Guidelines decreased the noise level equivalent (P1, 51.3 dB; P2, 48.3 dB), peak noise level (P1, 74.9 dB; P2, 70.8 dB), and the number of acoustic identified alarms (P1, 22.1 dB; P2, 15.8 dB) during P2. The night light levels were low during both periods, and lowering the light levels induced a greater variation of light, which may impair sleep quality. All measured noise levels were high during both periods, which could contribute to sleep disturbance, and the implementation of guidelines significantly lowers some important noise levels. The background noise level was unchanged.

  6. Absolute intensities and self-, N2-, and air-broadened Lorentz halfwidths for selected lines in the nu3 band of (C-12)H3D from measurements with a tunable diode laser spectrometer

    NASA Technical Reports Server (NTRS)

    Malathy Devi, V.; Benner, D. C.; Rinsland, C. P.; Smith, M. A. H.; Thakur, K. B.

    1986-01-01

    Absolute intensities and self-, air- and N2-broadened half-widths have been determined for the first time for individual lines in the nu3(A1) band of (C-12)H3D near 7.6 microns from measurements of individual vibration-rotation lines using a tunable diode laser spectrometer. The intensity measurements are believed to be accurate to within three percent. Within experimental uncertainties, equal broadening efficiencies are found for both air and nitrogen. Self-broadened half-widths determined for three transitions yield an average half-width value of 0.803 + or -0.0010/cm/atm at 296 K.

  7. Atmospheric Processing of Perovskite Solar Cells Using Intense Pulsed Light Sintering

    NASA Astrophysics Data System (ADS)

    Ankireddy, Krishnamraju; Lavery, Brandon W.; Druffel, Thad

    2018-02-01

    Atmospheric processing of metal-organic halide perovskite materials is highly desirable for large-scale manufacturing of solar cells. Atmospheric deposition and thermal processing of perovskite thin films for photovoltaic applications facilitated via rapid intense pulsed light (IPL) processing have been carried out. The interplay between the deposition chemistry, process, and IPL parameters to produce a functional photoactive thin film is discussed. Further addition of polyvinylpyrrolidone (PVP) as functional surfactant is explored to influence grain growth during the IPL process. Structural analysis by x-ray diffraction revealed formation of mixed-phase perovskite crystals from methylammonium chloride and lead iodide precursors. Ultraviolet-visible (UV-Vis) spectroscopy indicated that the light absorption by the perovskite films lay within a narrow band of the visible spectrum with bandgap of 2.9 eV. Scanning electron microscopy characterization of the surface morphology of the perovskite films revealed that addition of PVP to the ink chemistry assisted the IPL process in forming a fully covered surface with clearly defined grains. Functional devices with perovskite thin film processed by IPL under fully atmospheric conditions were demonstrated.

  8. Photo-enhanced toxicity of fluoranthene to Gulf of Mexico marine organisms at different larval ages and ultraviolet light intensities.

    PubMed

    Finch, Bryson E; Stubblefield, William A

    2016-05-01

    Significant increases in toxicity have been observed as a result of polycyclic aromatic hydrocarbon (PAH) absorption of ultraviolet (UV) radiation in aquatic organisms. Early life stage aquatic organisms are predicted to be more susceptible to PAH photo-enhanced toxicity as a result of their translucence and tendency to inhabit shallow littoral or surface waters. The objective of the present study was to evaluate the sensitivity of varying ages of larval mysid shrimp (Americamysis bahia), inland silverside (Menidia beryllina), sheepshead minnow (Cyprinodon variegatus), and Gulf killifish (Fundulus grandis) to photo-enhanced toxicity and to examine the correlation between photo-enhanced toxicity and organism pigmentation. Organisms were exposed to fluoranthene and artificial UV light at different larval ages and results were compared using median lethal concentrations (LC50s) and the lethal time-to-death (LT50s). In addition, a high UV light intensity, short-duration (4-h) experiment was conducted at approximately 24 W/m(2) of ultraviolet radiation A (UV-A) and compared with a low-intensity, long-duration (12-h) experiment at approximately 8 W/m(2) of UV-A. The results indicated decreased toxicity with increasing age for all larval organisms. The amount of organism pigmentation was correlated with observed LC50 and LT50 values. High-intensity short-duration exposure resulted in greater toxicity than low-intensity long-duration UV treatments for mysid shrimp, inland silverside, and sheepshead minnow. Data from these experiments suggest that toxicity is dependent on age, pigmentation, UV light intensity, and fluoranthene concentration. © 2015 SETAC.

  9. Observation of vasculature alternation by intense pulsed light combined with physicochemical methods.

    PubMed

    Son, Taeyoon; Kang, Heesung; Jung, Byungjo

    2016-05-01

    Intense pulsed light (IPL) with low energy insufficient to completely destroy a vasculature was applied to rabbit ears to investigate vasculature alteration. Glycerol was combined with IPL to enhance the transfer efficacy of IPL energy. Both trans-illumination and laser speckle contrast images were obtained and analyzed after treatment. The application of IPL and glycerol combination induced vasodilation and improvement in blood flow. Moreover, such phenomenon was maintained over time. IPL may be applied to treat blood circulatory diseases by inducing vasodilation and to improve blood flow. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. The relationship between maximum tolerated light intensity and photoprotective energy dissipation in the photosynthetic antenna: chloroplast gains and losses

    PubMed Central

    Ruban, Alexander V.; Belgio, Erica

    2014-01-01

    The principle of quantifying the efficiency of protection of photosystem II (PSII) reaction centres against photoinhibition by non-photochemical energy dissipation (NPQ) has been recently introduced by Ruban & Murchie (2012 Biochim. Biophys. Acta 1817, 977–982 (doi:10.1016/j.bbabio.2012.03.026)). This is based upon the assessment of two key parameters: (i) the relationship between the PSII yield and NPQ, and (ii) the fraction of intact PSII reaction centres in the dark after illumination. In this paper, we have quantified the relationship between the amplitude of NPQ and the light intensity at which all PSII reaction centres remain intact for plants with different levels of PsbS protein, known to play a key role in the process. It was found that the same, nearly linear, relationship exists between the levels of the protective NPQ component (pNPQ) and the tolerated light intensity in all types of studied plants. This approach allowed for the quantification of the maximum tolerated light intensity, the light intensity at which all plant leaves become photoinhibited, the fraction of (most likely) unnecessary or ‘wasteful’ NPQ, and the fraction of photoinhibited PSII reaction centres under conditions of prolonged illumination by full sunlight. It was concluded that the governing factors in the photoprotection of PSII are the level and rate of protective pNPQ formation, which are often in discord with the amplitude of the conventional measure of photoprotection, the quickly reversible NPQ component, qE. Hence, we recommend pNPQ as a more informative and less ambiguous parameter than qE, as it reflects the effectiveness and limitations of the major photoprotective process of the photosynthetic membrane. PMID:24591709

  11. Absolute flatness measurements of silicon mirrors by a three-intersection method by near-infrared interferometry

    PubMed Central

    2013-01-01

    Absolute flatness of three silicon plane mirrors have been measured by a three-intersection method based on the three-flat method using a near-infrared interferometer. The interferometer was constructed using a near-infrared laser diode with a 1,310-nm wavelength light where the silicon plane mirror is transparent. The height differences at the coordinate values between the absolute line profiles by the three-intersection method have been evaluated. The height differences of the three flats were 4.5 nm or less. The three-intersection method using the near-infrared interferometer was useful for measuring the absolute flatness of the silicon plane mirrors. PMID:23758916

  12. 14 CFR 29.1391 - Minimum intensities in the horizontal plane of forward and rear position lights.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...: Dihedral angle (light included) Angle from right or left of longitudinal axis, measured from dead ahead Intensity (candles) L and R (forward red and green) 0° to 10°10° to 20° 20° to 110° 4030 5 A (rear white...

  13. 14 CFR 29.1391 - Minimum intensities in the horizontal plane of forward and rear position lights.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...: Dihedral angle (light included) Angle from right or left of longitudinal axis, measured from dead ahead Intensity (candles) L and R (forward red and green) 0° to 10°10° to 20° 20° to 110° 4030 5 A (rear white...

  14. 14 CFR 27.1391 - Minimum intensities in the horizontal plane of forward and rear position lights.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...: Dihedral angle (light included) Angle from right or left of longitudinal axis, measured from dead ahead Intensity (candles) L and R (forward red and green) 10° to 10°10° to 20° 20° to 110° 4030 5 A (rear white...

  15. 14 CFR 25.1391 - Minimum intensities in the horizontal plane of forward and rear position lights.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...: Dihedral angle (light included) Angle from right or left of longitudinal axis, measured from dead ahead Intensity (candles) L and R (forward red and green) 0° to 10°10° to 20° 20° to 110° 4030 5 A (rear white...

  16. 14 CFR 29.1391 - Minimum intensities in the horizontal plane of forward and rear position lights.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...: Dihedral angle (light included) Angle from right or left of longitudinal axis, measured from dead ahead Intensity (candles) L and R (forward red and green) 0° to 10°10° to 20° 20° to 110° 4030 5 A (rear white...

  17. 14 CFR 27.1391 - Minimum intensities in the horizontal plane of forward and rear position lights.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...: Dihedral angle (light included) Angle from right or left of longitudinal axis, measured from dead ahead Intensity (candles) L and R (forward red and green) 10° to 10°10° to 20° 20° to 110° 4030 5 A (rear white...

  18. 14 CFR 25.1391 - Minimum intensities in the horizontal plane of forward and rear position lights.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...: Dihedral angle (light included) Angle from right or left of longitudinal axis, measured from dead ahead Intensity (candles) L and R (forward red and green) 0° to 10°10° to 20° 20° to 110° 4030 5 A (rear white...

  19. 14 CFR 27.1391 - Minimum intensities in the horizontal plane of forward and rear position lights.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...: Dihedral angle (light included) Angle from right or left of longitudinal axis, measured from dead ahead Intensity (candles) L and R (forward red and green) 10° to 10°10° to 20° 20° to 110° 4030 5 A (rear white...

  20. 14 CFR 27.1391 - Minimum intensities in the horizontal plane of forward and rear position lights.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...: Dihedral angle (light included) Angle from right or left of longitudinal axis, measured from dead ahead Intensity (candles) L and R (forward red and green) 10° to 10°10° to 20° 20° to 110° 4030 5 A (rear white...

  1. 14 CFR 29.1391 - Minimum intensities in the horizontal plane of forward and rear position lights.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...: Dihedral angle (light included) Angle from right or left of longitudinal axis, measured from dead ahead Intensity (candles) L and R (forward red and green) 0° to 10°10° to 20° 20° to 110° 4030 5 A (rear white...

  2. Intense visible light emission from stress-activated ZrO2:Ti

    NASA Astrophysics Data System (ADS)

    Akiyama, Morito; Xu, Chao-Nan; Nonaka, Kazuhiro

    2002-07-01

    We have investigated the luminescence phenomena from stress-activated ZrO2:Ti. The luminescence is clearly visible to the naked eye in the atmosphere. The luminescence center has been identified as the Ti4+ ion from spectra of the mechanoluminescence and also from photoluminescence studies of ZrO2:Ti. The mechanoluminescence intensity decreases on repetitive application of stress but recovers completely on irradiation with ultraviolet light. ZrO2 is an n-type semiconductor and has electron traps. It is suggested that the mechanoluminescence mechanism arises from the movement of dislocations and recombination between electrons and holes released from these traps which are associated with the Ti4+ centers.

  3. Determination of unique power conversion efficiency of solar cell showing hysteresis in the I-V curve under various light intensities.

    PubMed

    Cojocaru, Ludmila; Uchida, Satoshi; Tamaki, Koichi; Jayaweera, Piyankarage V V; Kaneko, Shoji; Nakazaki, Jotaro; Kubo, Takaya; Segawa, Hiroshi

    2017-09-18

    Energy harvesting at low light intensities has recently attracted a great deal of attention of perovskite solar cells (PSCs) which are regarded as promising candidate for indoor application. Anomalous hysteresis of the PSCs a complex issue for reliable evaluation of the cell performance. In order to address these challenges, we constructed two new evaluation methods to determinate the power conversion efficiencies (PCEs) of PSCs. The first setup is a solar simulator based on light emitting diodes (LEDs) allowing evaluation of the solar cells at wider range of light intensities, ranging from 10 2  to 10 -3  mW·cm -2 . As the overestimate error, we found that the PCEs of dye sensitized solar cell (DSC) and PSCs increase dramatically at low light intensities conditions. Due to the internal capacitance at the interfaces on hybrid solar cells, the measurement of current below 10 -2  mW·cm -2 shows constant value given high PCE, which is related to the capacitive current and origin of the hysteresis. The second setup is a photovoltaic power analyzing system, designed for tracking the maximum power (P max ) with time. The paper suggests the combination of the LED solar simulator and P max tracking technique as a standard to evaluate the PCE of capacitive solar cells.

  4. 14 CFR 25.1391 - Minimum intensities in the horizontal plane of forward and rear position lights.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...: Dihedral angle (light included) Angle from right or left of longitudinal axis, measured from dead ahead Intensity (candles) L and R (forward red and green) 0° to 10° 10° to 20° 20° to 110° 40 30 5 A (rear white...

  5. 14 CFR 25.1391 - Minimum intensities in the horizontal plane of forward and rear position lights.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...: Dihedral angle (light included) Angle from right or left of longitudinal axis, measured from dead ahead Intensity (candles) L and R (forward red and green) 0° to 10° 10° to 20° 20° to 110° 40 30 5 A (rear white...

  6. Effects of UV light intensity on electrochemical wet etching of SiC for the fabrication of suspended graphene

    NASA Astrophysics Data System (ADS)

    O, Ryong-Sok; Takamura, Makoto; Furukawa, Kazuaki; Nagase, Masao; Hibino, Hiroki

    2015-03-01

    We report on the effects of UV light intensity on the photo assisted electrochemical wet etching of SiC(0001) underneath an epitaxially grown graphene for the fabrication of suspended structures. The maximum etching rate of SiC(0001) was 2.5 µm/h under UV light irradiation in 1 wt % KOH at a constant current of 0.5 mA/cm2. The successful formation of suspended structures depended on the etching rate of SiC. In the Raman spectra of the suspended structures, we did not observe a significant increase in the intensity of the D peak, which originates from defects in graphene sheets. This is most likely explained by the high quality of the single-crystalline graphene epitaxially grown on SiC.

  7. Understanding the molecular mechanisms underlying the effects of light intensity on flavonoid production by RNA-seq analysis in Epimedium pseudowushanense B.L.Guo

    PubMed Central

    Chen, Haimei; Guo, Baolin; Liu, Chang

    2017-01-01

    Epimedium pseudowushanense B.L.Guo, a light-demanding shade herb, is used in traditional medicine to increase libido and strengthen muscles and bones. The recognition of the health benefits of Epimedium has increased its market demand. However, its resource recycling rate is low and environmentally dependent. Furthermore, its natural sources are endangered, further increasing prices. Commercial culture can address resource constraints of it.Understanding the effects of environmental factors on the production of its active components would improve the technology for cultivation and germplasm conservation. Here, we studied the effects of light intensities on the flavonoid production and revealed the molecular mechanism using RNA-seq analysis. Plants were exposed to five levels of light intensity through the periods of germination to flowering, the flavonoid contents were measured using HPLC. Quantification of epimedin A, epimedin B, epimedin C, and icariin showed that the flavonoid contents varied with different light intensity levels. And the largest amount of epimedin C was produced at light intensity level 4 (I4). Next, the leaves under the treatment of three light intensity levels (“L”, “M” and “H”) with the largest differences in the flavonoid content, were subjected to RNA-seq analysis. Transcriptome reconstruction identified 43,657 unigenes. All unigene sequences were annotated by searching against the Nr, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. In total, 4008, 5260, and 3591 significant differentially expressed genes (DEGs) were identified between the groups L vs. M, M vs. H and L vs. H. Particularly, twenty-one full-length genes involved in flavonoid biosynthesis were identified. The expression levels of the flavonol synthase, chalcone synthase genes were strongly associated with light-induced flavonoid abundance with the highest expression levels found in the H group. Furthermore, 65 transcription factors

  8. Absolute biological needs.

    PubMed

    McLeod, Stephen

    2014-07-01

    Absolute needs (as against instrumental needs) are independent of the ends, goals and purposes of personal agents. Against the view that the only needs are instrumental needs, David Wiggins and Garrett Thomson have defended absolute needs on the grounds that the verb 'need' has instrumental and absolute senses. While remaining neutral about it, this article does not adopt that approach. Instead, it suggests that there are absolute biological needs. The absolute nature of these needs is defended by appeal to: their objectivity (as against mind-dependence); the universality of the phenomenon of needing across the plant and animal kingdoms; the impossibility that biological needs depend wholly upon the exercise of the abilities characteristic of personal agency; the contention that the possession of biological needs is prior to the possession of the abilities characteristic of personal agency. Finally, three philosophical usages of 'normative' are distinguished. On two of these, to describe a phenomenon or claim as 'normative' is to describe it as value-dependent. A description of a phenomenon or claim as 'normative' in the third sense does not entail such value-dependency, though it leaves open the possibility that value depends upon the phenomenon or upon the truth of the claim. It is argued that while survival needs (or claims about them) may well be normative in this third sense, they are normative in neither of the first two. Thus, the idea of absolute need is not inherently normative in either of the first two senses. © 2013 John Wiley & Sons Ltd.

  9. A vibration-insensitive optical cavity and absolute determination of its ultrahigh stability.

    PubMed

    Zhao, Y N; Zhang, J; Stejskal, A; Liu, T; Elman, V; Lu, Z H; Wang, L J

    2009-05-25

    We use the three-cornered-hat method to evaluate the absolute frequency stabilities of three different ultrastable reference cavities, one of which has a vibration-insensitive design that does not even require vibration isolation. An Nd:YAG laser and a diode laser are implemented as light sources. We observe approximately 1 Hz beat note linewidths between all three cavities. The measurement demonstrates that the vibration-insensitive cavity has a good frequency stability over the entire measurement time from 100 ms to 200 s. An absolute, correlation-removed Allan deviation of 1.4 x 10(-15) at s of this cavity is obtained, giving a frequency uncertainty of only 0.44 Hz.

  10. Full-Field Calibration of Color Camera Chromatic Aberration using Absolute Phase Maps.

    PubMed

    Liu, Xiaohong; Huang, Shujun; Zhang, Zonghua; Gao, Feng; Jiang, Xiangqian

    2017-05-06

    The refractive index of a lens varies for different wavelengths of light, and thus the same incident light with different wavelengths has different outgoing light. This characteristic of lenses causes images captured by a color camera to display chromatic aberration (CA), which seriously reduces image quality. Based on an analysis of the distribution of CA, a full-field calibration method based on absolute phase maps is proposed in this paper. Red, green, and blue closed sinusoidal fringe patterns are generated, consecutively displayed on an LCD (liquid crystal display), and captured by a color camera from the front viewpoint. The phase information of each color fringe is obtained using a four-step phase-shifting algorithm and optimum fringe number selection method. CA causes the unwrapped phase of the three channels to differ. These pixel deviations can be computed by comparing the unwrapped phase data of the red, blue, and green channels in polar coordinates. CA calibration is accomplished in Cartesian coordinates. The systematic errors introduced by the LCD are analyzed and corrected. Simulated results show the validity of the proposed method and experimental results demonstrate that the proposed full-field calibration method based on absolute phase maps will be useful for practical software-based CA calibration.

  11. Absolute charge calibration of scintillating screens for relativistic electron detection

    NASA Astrophysics Data System (ADS)

    Buck, A.; Zeil, K.; Popp, A.; Schmid, K.; Jochmann, A.; Kraft, S. D.; Hidding, B.; Kudyakov, T.; Sears, C. M. S.; Veisz, L.; Karsch, S.; Pawelke, J.; Sauerbrey, R.; Cowan, T.; Krausz, F.; Schramm, U.

    2010-03-01

    We report on new charge calibrations and linearity tests with high-dynamic range for eight different scintillating screens typically used for the detection of relativistic electrons from laser-plasma based acceleration schemes. The absolute charge calibration was done with picosecond electron bunches at the ELBE linear accelerator in Dresden. The lower detection limit in our setup for the most sensitive scintillating screen (KODAK Biomax MS) was 10 fC/mm2. The screens showed a linear photon-to-charge dependency over several orders of magnitude. An onset of saturation effects starting around 10-100 pC/mm2 was found for some of the screens. Additionally, a constant light source was employed as a luminosity reference to simplify the transfer of a one-time absolute calibration to different experimental setups.

  12. Low light intensity effects on the growth, photosynthetic characteristics, antioxidant capacity, yield and quality of wheat (Triticum aestivum L.) at different growth stages in BLSS

    NASA Astrophysics Data System (ADS)

    Dong, Chen; Fu, Yuming; Liu, Guanghui; Liu, Hong

    2014-06-01

    Minimizing energy consumption and maximizing crop productivity are major challenges to growing plants in Bioregenerative Life Support System (BLSS) for future long-term space mission. As a primary source of energy, light is one of the most important environmental factors for plant growth. The purpose of this study is to investigate the effects of low light intensity at different stages on growth, pigment composition, photosynthetic efficiency, biological production and antioxidant defence systems of wheat (Triticum aestivum L.) cultivars during ontogenesis. Experiments were divided into 3 intensity-controlled stages according to growth period (a total of 65 days): seedling stage (first 20 days), heading and flowering stage (middle 30 days) and grain filling stage (last 15 days). Initial light condition of the control was 420 μmol m-2 s-1 and the light intensity increased with the growth of wheat plants. The light intensities of group I and II at the first stage and the last stage were adjusted to the half level of the control respectively. For group III, the first and the last stage were both adjusted to half level of the control. During the middle 30 days, all treatments were kept the same intensity. The results indicated that low-light treatment at seedling stage, biomass, nutritional contents, components of inedible biomass and healthy index (including peroxidase (POD) activity, malondialdehyde (MDA) and proline content) of wheat plants have no significant difference to the control. Furthermore, unit kilojoule yield of group I reached 0.591 × 10-3 g/kJ and induced the highest energy efficiency. However, low-light treatment at grain filling stage affected the final production significantly.

  13. Absolute dose calculations for Monte Carlo simulations of radiotherapy beams

    NASA Astrophysics Data System (ADS)

    Popescu, I. A.; Shaw, C. P.; Zavgorodni, S. F.; Beckham, W. A.

    2005-07-01

    Monte Carlo (MC) simulations have traditionally been used for single field relative comparisons with experimental data or commercial treatment planning systems (TPS). However, clinical treatment plans commonly involve more than one field. Since the contribution of each field must be accurately quantified, multiple field MC simulations are only possible by employing absolute dosimetry. Therefore, we have developed a rigorous calibration method that allows the incorporation of monitor units (MU) in MC simulations. This absolute dosimetry formalism can be easily implemented by any BEAMnrc/DOSXYZnrc user, and applies to any configuration of open and blocked fields, including intensity-modulated radiation therapy (IMRT) plans. Our approach involves the relationship between the dose scored in the monitor ionization chamber of a radiotherapy linear accelerator (linac), the number of initial particles incident on the target, and the field size. We found that for a 10 × 10 cm2 field of a 6 MV photon beam, 1 MU corresponds, in our model, to 8.129 × 1013 ± 1.0% electrons incident on the target and a total dose of 20.87 cGy ± 1.0% in the monitor chambers of the virtual linac. We present an extensive experimental verification of our MC results for open and intensity-modulated fields, including a dynamic 7-field IMRT plan simulated on the CT data sets of a cylindrical phantom and of a Rando anthropomorphic phantom, which were validated by measurements using ionization chambers and thermoluminescent dosimeters (TLD). Our simulation results are in excellent agreement with experiment, with percentage differences of less than 2%, in general, demonstrating the accuracy of our Monte Carlo absolute dose calculations.

  14. Absolute dose calculations for Monte Carlo simulations of radiotherapy beams.

    PubMed

    Popescu, I A; Shaw, C P; Zavgorodni, S F; Beckham, W A

    2005-07-21

    Monte Carlo (MC) simulations have traditionally been used for single field relative comparisons with experimental data or commercial treatment planning systems (TPS). However, clinical treatment plans commonly involve more than one field. Since the contribution of each field must be accurately quantified, multiple field MC simulations are only possible by employing absolute dosimetry. Therefore, we have developed a rigorous calibration method that allows the incorporation of monitor units (MU) in MC simulations. This absolute dosimetry formalism can be easily implemented by any BEAMnrc/DOSXYZnrc user, and applies to any configuration of open and blocked fields, including intensity-modulated radiation therapy (IMRT) plans. Our approach involves the relationship between the dose scored in the monitor ionization chamber of a radiotherapy linear accelerator (linac), the number of initial particles incident on the target, and the field size. We found that for a 10 x 10 cm2 field of a 6 MV photon beam, 1 MU corresponds, in our model, to 8.129 x 10(13) +/- 1.0% electrons incident on the target and a total dose of 20.87 cGy +/- 1.0% in the monitor chambers of the virtual linac. We present an extensive experimental verification of our MC results for open and intensity-modulated fields, including a dynamic 7-field IMRT plan simulated on the CT data sets of a cylindrical phantom and of a Rando anthropomorphic phantom, which were validated by measurements using ionization chambers and thermoluminescent dosimeters (TLD). Our simulation results are in excellent agreement with experiment, with percentage differences of less than 2%, in general, demonstrating the accuracy of our Monte Carlo absolute dose calculations.

  15. Effect of varying light intensity on blood physiological reactions of broiler chickens grown to heavy weights

    USDA-ARS?s Scientific Manuscript database

    This study investigated effects of varying levels of light intensities (25, 10, 5, 2.5, and 0.2 lx) from 22 to 56 d of age at 50% RH on blood acid-base balance, metabolites, and electrolytes of heavy broilers reared under environmentally controlled conditions. Four identical trials were conducted wi...

  16. Concept of white light in stage lighting

    NASA Astrophysics Data System (ADS)

    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.

  17. Polyphenolic composition and antioxidant capacity of legume based swards are affected by light intensity in a Mediterranean agroforestry system.

    PubMed

    Re, Giovanni Antonio; Piluzza, Giovanna; Sanna, Federico; Molinu, Maria Giovanna; Sulas, Leonardo

    2018-06-01

    In Mediterranean grazed woodlands, microclimate changes induced by trees influence the growth and development of the understory, but very little is known about its polyphenolic composition in relation to light intensity. We investigated the bioactive compounds and antioxidant capacity of different legume-based swards and variations due to full sunlight and partial shade. The research was carried out in a cork oak agrosilvopastoral system in Sardinia. The highest values of DPPH reached 7 mmol TEAC 100 g -1 DW, total phenolics 67.1 g GAE kg -1 DW and total flavonoids 7.5 g CE kg -1 DW. Compared to full sunlight, partial shade reduced DPPH values by 29 and 42%, and the total phenolic content by 23 and 53% in 100% legume mixture and semi natural pasture. Twelve phenolic compounds were detected: chlorogenic acid in 80% legume mixture (partial shade) and verbascoside in pure sward of bladder clover (full sunlight) were the most abundant. Light intensity significantly affected antioxidant capacity, composition and levels of phenolic compounds. Our results provide new insights into the effects of light intensity on plant secondary metabolites from legume based swards, underlining the important functions provided by agroforestry systems. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  18. Improvement of Gaofen-3 Absolute Positioning Accuracy Based on Cross-Calibration

    PubMed Central

    Deng, Mingjun; Li, Jiansong

    2017-01-01

    The Chinese Gaofen-3 (GF-3) mission was launched in August 2016, equipped with a full polarimetric synthetic aperture radar (SAR) sensor in the C-band, with a resolution of up to 1 m. The absolute positioning accuracy of GF-3 is of great importance, and in-orbit geometric calibration is a key technology for improving absolute positioning accuracy. Conventional geometric calibration is used to accurately calibrate the geometric calibration parameters of the image (internal delay and azimuth shifts) using high-precision ground control data, which are highly dependent on the control data of the calibration field, but it remains costly and labor-intensive to monitor changes in GF-3’s geometric calibration parameters. Based on the positioning consistency constraint of the conjugate points, this study presents a geometric cross-calibration method for the rapid and accurate calibration of GF-3. The proposed method can accurately calibrate geometric calibration parameters without using corner reflectors and high-precision digital elevation models, thus improving absolute positioning accuracy of the GF-3 image. GF-3 images from multiple regions were collected to verify the absolute positioning accuracy after cross-calibration. The results show that this method can achieve a calibration accuracy as high as that achieved by the conventional field calibration method. PMID:29240675

  19. Subcarrier intensity modulation for MIMO visible light communications

    NASA Astrophysics Data System (ADS)

    Celik, Yasin; Akan, Aydin

    2018-04-01

    In this paper, subcarrier intensity modulation (SIM) is investigated for multiple-input multiple-output (MIMO) visible light communication (VLC) systems. A new modulation scheme called DC-aid SIM (DCA-SIM) is proposed for the spatial modulation (SM) transmission plan. Then, DCA-SIM is extended for multiple subcarrier case which is called DC-aid Multiple Subcarrier Modulation (DCA-MSM). Bit error rate (BER) performances of the considered system are analyzed for different MIMO schemes. The power efficiencies of DCA-SIM and DCA-MSM are shown in correlated MIMO VLC channels. The upper bound BER performances of the proposed models are obtained analytically for PSK and QAM modulation types in order to validate the simulation results. Additionally, the effect of power imbalance method on the performance of SIM is studied and remarkable power gains are obtained compared to the non-power imbalanced cases. In this work, Pulse amplitude modulation (PAM) and MSM-Index are used as benchmarks for single carrier and multiple carrier cases, respectively. And the results show that the proposed schemes outperform PAM and MSM-Index for considered single carrier and multiple carrier communication scenarios.

  20. Impact of high-intensity interval training and moderate-intensity continuous training on resting and postexercise cardiac troponin T concentration.

    PubMed

    Nie, Jinlei; Zhang, Haifeng; Kong, Zhaowei; George, Keith; Little, Jonathan P; Tong, Tomas K; Li, Feifei; Shi, Qingde

    2018-03-01

    What is the central question of this study? Does exercise training impact resting and postexercise cardiac troponin T (cTnT) concentration? What is the main finding and its importance? This randomized controlled intervention study demonstrated that 12 weeks of either high-intensity interval training or moderate-intensity continuous training largely abolished the exercise-induced elevation in cTnT when exercise was performed at the same absolute intensity. There was no impact of training on resting cTnT or postexercise appearance of cTnT when exercise was performed at the same relative intensity. These findings provide new information that might help clinicians with decision-making in relationship to basal and postexercise values of cTnT in individuals with different training status. We evaluated the influence of 12 weeks of high-intensity interval training [HIIT; repeated 4 min cycling at 90% of maximal oxygen uptake (V̇O2max) interspersed with 3 min rest, 200-300 kJ per session, 3 or 4 days each week] and work-equivalent moderate-intensity continuous training (MICT; continuous cycling at 60% V̇O2max) on resting cardiac troponin T (cTnT) and the appearance of exercise-induced cTnT. Forty-eight sedentary obese young women were randomly assigned to HIIT, MICT or a control group. The V̇O2max and body composition were measured before and after training. At baseline, cTnT was assessed using a high-sensitivity assay at rest and immediately, 2 and 4 h after 45 min cycling at 60% V̇O2max. After a 12 week training period, cTnT was assessed before and after 45 min cycling at the same relative and absolute intensities as before training. Training led to higher V̇O2max and lower fat mass in both HIIT and MICT groups (all P < 0.05). Before training, cTnT was significantly elevated in all three groups (by 35-118%, all P < 0.05) with acute exercise. After training, both resting and postexercise cTnT concentrations (same relative intensity) were similar to

  1. Responses of crayfish photoreceptor cells following intense light adaptation.

    PubMed

    Cummins, D R; Goldsmith, T H

    1986-01-01

    After intense orange adapting exposures that convert 80% of the rhodopsin in the eye to metarhodopsin, rhabdoms become covered with accessory pigment and appear to lose some microvillar order. Only after a delay of hours or even days is the metarhodopsin replaced by rhodopsin (Cronin and Goldsmith 1984). After 24 h of dark adaptation, when there has been little recovery of visual pigment, the photoreceptor cells have normal resting potentials and input resistances, and the reversal potential of the light response is 10-15 mV (inside positive), unchanged from controls. The log V vs log I curve is shifted about 0.6 log units to the right on the energy axis, quantitatively consistent with the decrease in the probability of quantum catch expected from the lowered concentration of rhodopsin in the rhabdoms. Furthermore, at 24 h the photoreceptors exhibit a broader spectral sensitivity than controls, which is also expected from accumulations of metarhodopsin in the rhabdoms. In three other respects, however, the transduction process appears to be light adapted: The voltage responses are more phasic than those of control photoreceptors. The relatively larger effect (compared to controls) of low extracellular Ca++ (1 mmol/l EGTA) in potentiating the photoresponses suggests that the photoreceptors may have elevated levels of free cytoplasmic Ca++. The saturating depolarization is only about 30% as large as the maximal receptor potentials of contralateral, dark controls, and by that measure the log V-log I curve is shifted downward by 0.54 log units.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Light field creating and imaging with different order intensity derivatives

    NASA Astrophysics Data System (ADS)

    Wang, Yu; Jiang, Huan

    2014-10-01

    Microscopic image restoration and reconstruction is a challenging topic in the image processing and computer vision, which can be widely applied to life science, biology and medicine etc. A microscopic light field creating and three dimensional (3D) reconstruction method is proposed for transparent or partially transparent microscopic samples, which is based on the Taylor expansion theorem and polynomial fitting. Firstly the image stack of the specimen is divided into several groups in an overlapping or non-overlapping way along the optical axis, and the first image of every group is regarded as reference image. Then different order intensity derivatives are calculated using all the images of every group and polynomial fitting method based on the assumption that the structure of the specimen contained by the image stack in a small range along the optical axis are possessed of smooth and linear property. Subsequently, new images located any position from which to reference image the distance is Δz along the optical axis can be generated by means of Taylor expansion theorem and the calculated different order intensity derivatives. Finally, the microscopic specimen can be reconstructed in 3D form using deconvolution technology and all the images including both the observed images and the generated images. The experimental results show the effectiveness and feasibility of our method.

  3. Effects of spectral composition, photoperiod and light intensity on the gonadal development of Atlantic salmon Salmo salar in recirculating aquaculture systems (RAS)

    NASA Astrophysics Data System (ADS)

    Qiu, Denggao; Xu, Shihong; Song, Changbin; Chi, Liang; Li, Xian; Sun, Guoxiang; Liu, Baoliang; Liu, Ying

    2015-01-01

    Artificial lighting regimes have been successfully used to inhibit sexual maturity of Atlantic salmon in confinement. However, when these operations are applied in commercial recirculating aquaculture systems (RAS) using standard lighting technology, sexual maturation is not suppressed. In this study, an L9 (33) orthogonal design was used to determine the effects of three factors (spectral composition, photoperiod, and light intensity) on the gonadal development of Atlantic salmon in RAS. We demonstrated that the photoperiod at the tested levels had a much greater effect on the gonadosomatic index and female Fulton condition factor than spectral composition and light intensity. The photoperiod had a significant effect on the secretion of sex steroids and melatonin ( P<0.05), and a short photoperiod delayed sex steroid and melatonin level increases. The three test factors had no significant effects on the survival rate, specific growth rate, relative weight gain, and male Fulton condition factor ( P>0.05). The optimum lighting levels in female and male Atlantic salmon were LD 8:16, 455 nm (or 625 nm), 8.60 W/m2; and LD 8:16, 8.60 W/m2, 455 nm respectively. These conditions not only delayed gonadal development, but also had no negative effects on Atlantic salmon growth in RAS. These results demonstrate that a combination of spectral composition, photoperiod and light intensity is effective at delaying the gonadal development of both male and female salmon in RAS.

  4. Light intensity-voltage correlations and leakage-current excess noise in a single-mode semiconductor laser

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Maurin, I.; Bramati, A.; Giacobino, E.

    2005-09-15

    Semiconductor lasers are particularly well suited for the implementation of pump-noise suppression, yielding a reduction of the intensity noise in the laser. In this simple picture, the maximal amount of squeezing is equal to the quantum efficiency. However, experimental results on intensity noise reduction by pump-noise suppression are usually above this limit. This discrepancy suggests that additional noise sources must be involved. Here we successful y interpret the full noise behavior of a single-mode laser diode far above threshold by considering two excess noise sources: the leakage current fluctuations across the laser and the Petermann excess noise. We have estimatedmore » the contribution of each noise source using the results of the correlations between the laser output intensity noise and the voltage fluctuations across the laser diode (light-voltage correlations) and obtained good agreement between our theory and experimental results.« less

  5. Membrane development in purple photosynthetic bacteria in response to alterations in light intensity and oxygen tension.

    PubMed

    Niederman, Robert A

    2013-10-01

    Studies on membrane development in purple bacteria during adaptation to alterations in light intensity and oxygen tension are reviewed. Anoxygenic phototrophic such as the purple α-proteobacterium Rhodobacter sphaeroides have served as simple, dynamic, and experimentally accessible model organisms for studies of the photosynthetic apparatus. A major landmark in photosynthesis research, which dramatically illustrates this point, was provided by the determination of the X-ray structure of the reaction center (RC) in Blastochloris viridis (Deisenhofer and Michel, EMBO J 8:2149-2170, 1989), once it was realized that this represented the general structure for the photosystem II RC present in all oxygenic phototrophs. This seminal advance, together with a considerable body of subsequent research on the light-harvesting (LH) and electron transfer components of the photosynthetic apparatus has provided a firm basis for the current understanding of how phototrophs acclimate to alterations in light intensity and quality. Oxygenic phototrophs adapt to these changes by extensive thylakoid membrane remodeling, which results in a dramatic supramolecular reordering to assure that an appropriate flow of quinone redox species occurs within the membrane bilayer for efficient and rapid electron transfer. Despite the high level of photosynthetic unit organization in Rba. sphaeroides as observed by atomic force microscopy (AFM), fluorescence induction/relaxation measurements have demonstrated that the addition of the peripheral LH2 antenna complex in cells adapting to low-intensity illumination results in a slowing of the rate of electron transfer turnover by the RC of up to an order of magnitude. This is ascribed to constraints in quinone redox species diffusion between the RC and cytochrome bc1 complexes arising from the increased packing density as the intracytoplasmic membrane (ICM) bilayer becomes crowded with LH2 rings. In addition to downshifts in light intensity as a paradigm

  6. Effect of molecular anisotropy on the intensity and degree of polarization of light scattered from model atmospheres

    NASA Technical Reports Server (NTRS)

    Bahethi, O. P.; Fraser, R. S.

    1975-01-01

    Computations of the intensity, flux, degree of polarization, and the positions of neutral points are presented for models of the terrestrial gaseous and hazy atmospheres by incorporating the molecular anisotropy due to air in the Rayleigh scattering optical thickness and phase matrix. Molecular anisotropy causes significant changes in the intensity, flux and the degree of polarization of the scattered light. The positions of neutral points do not change significantly. When the Rayleigh scattering optical thickness is kept constant and the molecular anisotropy factor is included only in the Rayleigh phase matrix, the flux does not change and the intensity and positions of neutron points change by a small amount. The changes in the degree of polarization are still significant.

  7. Modulating emission intensity of GaN-based green light emitting diodes on c-plane sapphire

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Du, Chunhua; Ma, Ziguang; Zhou, Junming

    2014-04-14

    The asymmetric dual-wavelength (green/blue) coupled InGaN/GaN multiple quantum wells were proposed to modulate the green emission intensity. Electroluminescent measurements demonstrate the conspicuous increment of the green light intensity by decreasing the coupled barrier thickness. This was partly attributed to capture of more carriers when holes tunnel across the thinner barrier from the blue quantum wells, as a hole reservoir, to the green quantum wells. While lower effective barrier height of the blue quantum wells benefits improved hole transportation from p-GaN to the active region. Efficiency droop of the green quantum wells was partially alleviated due to the enhanced injection efficiencymore » of holes.« less

  8. Jasminum flexile flower absolute from India--a detailed comparison with three other jasmine absolutes.

    PubMed

    Braun, Norbert A; Kohlenberg, Birgit; Sim, Sherina; Meier, Manfred; Hammerschmidt, Franz-Josef

    2009-09-01

    Jasminum flexile flower absolute from the south of India and the corresponding vacuum headspace (VHS) sample of the absolute were analyzed using GC and GC-MS. Three other commercially available Indian jasmine absolutes from the species: J. sambac, J. officinale subsp. grandiflorum, and J. auriculatum and the respective VHS samples were used for comparison purposes. One hundred and twenty-one compounds were characterized in J. flexile flower absolute, with methyl linolate, benzyl salicylate, benzyl benzoate, (2E,6E)-farnesol, and benzyl acetate as the main constituents. A detailed olfactory evaluation was also performed.

  9. The relationship between thermal comfort and light intensity with sleep quality and eye tiredness in shift work nurses.

    PubMed

    Azmoon, Hiva; Dehghan, Habibollah; Akbari, Jafar; Souri, Shiva

    2013-01-01

    Environmental conditions such as lighting and thermal comfort are influencing factors on sleep quality and visual tiredness. The purpose of this study was the determination of the relationship between thermal comfort and light intensity with the sleep quality and eye fatigue in shift nurses. This cross-sectional research was conducted on 82 shift-work personnel of 18 nursing workstations in Isfahan Al-Zahra Hospital, Iran, in 2012. Heat stress monitoring (WBGT) and photometer (Hagner Model) were used for measuring the thermal conditions and illumination intensity, respectively. To measure the sleep quality, visual tiredness, and thermal comfort, Pittsburg sleep quality index, eye fatigue questionnaire, and thermal comfort questionnaire were used, respectively. The data were analyzed with descriptive statistics, Student's t-test, and Pearson correlation. Correlation between thermal comfort which was perceived from the self-reporting of people with eye tiredness was -0.38 (P = 0.002). Pearson correlation between thermal comfort and sleep quality showed a positive and direct relationship (r = 0.241, P = 0.33) but the correlation between thermal comfort, which was perceived from the self-reporting of shift nurses, and WBGT index was a weak relationship (r = 0.019). Based on the obtained findings, it can be concluded that a defect in environmental conditions such as thermal conditions and light intensity and also lack of appropriate managerial plan for night shift-work nurses are destructive and negative factors for the physical and mental health of this group of practitioners.

  10. The Relationship between Thermal Comfort and Light Intensity with Sleep Quality and Eye Tiredness in Shift Work Nurses

    PubMed Central

    Azmoon, Hiva; Dehghan, Habibollah; Akbari, Jafar; Souri, Shiva

    2013-01-01

    Environmental conditions such as lighting and thermal comfort are influencing factors on sleep quality and visual tiredness. The purpose of this study was the determination of the relationship between thermal comfort and light intensity with the sleep quality and eye fatigue in shift nurses. Method. This cross-sectional research was conducted on 82 shift-work personnel of 18 nursing workstations in Isfahan Al-Zahra Hospital, Iran, in 2012. Heat stress monitoring (WBGT) and photometer (Hagner Model) were used for measuring the thermal conditions and illumination intensity, respectively. To measure the sleep quality, visual tiredness, and thermal comfort, Pittsburg sleep quality index, eye fatigue questionnaire, and thermal comfort questionnaire were used, respectively. The data were analyzed with descriptive statistics, Student's t-test, and Pearson correlation. Results. Correlation between thermal comfort which was perceived from the self-reporting of people with eye tiredness was −0.38 (P = 0.002). Pearson correlation between thermal comfort and sleep quality showed a positive and direct relationship (r = 0.241, P = 0.33) but the correlation between thermal comfort, which was perceived from the self-reporting of shift nurses, and WBGT index was a weak relationship (r = 0.019). Conclusion. Based on the obtained findings, it can be concluded that a defect in environmental conditions such as thermal conditions and light intensity and also lack of appropriate managerial plan for night shift-work nurses are destructive and negative factors for the physical and mental health of this group of practitioners. PMID:23476674

  11. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K [Pleasanton, CA; Snyderman, Neal J [Berkeley, CA; Rowland, Mark S [Alamo, CA

    2012-05-15

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  12. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K [Pleasanton, CA; Snyderman, Neal J [Berkeley, CA; Rowland, Mark S [Alamo, CA

    2010-07-13

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  13. Effects of Melatonin on Morphological and Functional Parameters of the Pineal Gland and Organs of Immune System in Rats During Natural Light Cycle and Constant Illumination.

    PubMed

    Litvinenko, G I; Shurlygina, A V; Gritsyk, O B; Mel'nikova, E V; Tenditnik, M V; Avrorov, P A; Trufakin, V A

    2015-10-01

    We studied the response of the pineal gland and organs of the immune system to melatonin treatment in Wistar rats kept under conditions of abnormal illumination regimen. The animals were kept under natural light regimen or continuous illumination for 14 days and then received daily injections of melatonin (once a day in the evening) for 7 days. Administration of melatonin to rats kept at natural light cycle was followed by a decrease in percent ratio of CD4+8+ splenocytes and CD4-8+ thymocytes. In 24-h light with the following melatonin injections were accompanied by an increase in percent rate and absolute amount of CD4+8+ cells in the spleen, and a decrease in percent rate of CD11b/c and CD4-8+ splenocytes. In the thymus amount of CD4-8+ cells increased, and absolute number of CD4+25+ cells reduced. Melatonin significantly decreased lipofuscin concentration in the pineal gland during continuous light. Direction and intensity of effects of melatonin on parameters of cell immunity and state of the pineal gland were different under normal and continuous light conditions. It should be taken into account during using of this hormone for correction of immune and endocrine impairments developing during change in light/dark rhythm.

  14. Light Intensity physical activity and sedentary behavior in relation to body mass index and grip strength in older adults: cross-sectional findings from the Lifestyle Interventions and Independence for Elders (LIFE) study.

    PubMed

    Bann, David; Hire, Don; Manini, Todd; Cooper, Rachel; Botoseneanu, Anda; McDermott, Mary M; Pahor, Marco; Glynn, Nancy W; Fielding, Roger; King, Abby C; Church, Timothy; Ambrosius, Walter T; Gill, Thomas M; Gill, Thomas

    2015-01-01

    Identifying modifiable determinants of fat mass and muscle strength in older adults is important given their impact on physical functioning and health. Light intensity physical activity and sedentary behavior are potential determinants, but their relations to these outcomes are poorly understood. We evaluated associations of light intensity physical activity and sedentary time-assessed both objectively and by self-report-with body mass index (BMI) and grip strength in a large sample of older adults. We used cross-sectional baseline data from 1130 participants of the Lifestyle Interventions and Independence for Elders (LIFE) study, a community-dwelling sample of relatively sedentary older adults (70-89 years) at heightened risk of mobility disability. Time spent sedentary and in light intensity activity were assessed using an accelerometer worn for 3-7 days (Actigraph GT3X) and by self-report. Associations between these exposures and measured BMI and grip strength were evaluated using linear regression. Greater time spent in light intensity activity and lower sedentary times were both associated with lower BMI. This was evident using objective measures of lower-light intensity, and both objective and self-reported measures of higher-light intensity activity. Time spent watching television was positively associated with BMI, while reading and computer use were not. Greater time spent in higher but not lower intensities of light activity (assessed objectively) was associated with greater grip strength in men but not women, while neither objectively assessed nor self-reported sedentary time was associated with grip strength. In this cross-sectional study, greater time spent in light intensity activity and lower sedentary times were associated with lower BMI. These results are consistent with the hypothesis that replacing sedentary activities with light intensity activities could lead to lower BMI levels and obesity prevalence among the population of older adults

  15. Computer analysis of environmental temperature, light and noise in intensive care: chaos or chronome nurseries?

    PubMed

    Ardura, J; Andrés, J; Aldana, J; Revilla, M A; Cornélissen, G; Halberg, F

    1997-09-01

    Lighting, noise and temperature were monitored in two perinatal nurseries. Rhythms of several frequencies were found, including prominent 24-hour rhythms with acrophases around 13:00 (light intensity) and 16:00 (noise). For light and noise, the ratio formed by dividing the amplitude of a 1-week (circaseptan) or half-week (circasemiseptan) fitted cosine curve by the amplitude of a 24-hour fitted cosine curve is smaller than unity, since 24-hour rhythms are prominent for these variables. The amplitude ratios are larger than unity for temperature in the newborns' unit but not in the infants' unit. Earlier, the origin of the about-7-day rhythms of neonatal physiologic variables was demonstrated to have, in addition to a major endogenous, also a minor exogenous component. Hence, the possibility of optimizing maturation by manipulating environmental changes can be considered, using, as gauges of development, previously mapped chronomes (time structures of biologic multifrequency rhythms, trends and noise).

  16. Effects of water stress and light intensity on chlorophyll fluorescence parameters and pigments of Aloe vera L.

    PubMed

    Hazrati, Saeid; Tahmasebi-Sarvestani, Zeinolabedin; Modarres-Sanavy, Seyed Ali Mohammad; Mokhtassi-Bidgoli, Ali; Nicola, Silvana

    2016-09-01

    Aloe vera L. is one of the most important medicinal plants in the world. In order to determine the effects of light intensity and water deficit stress on chlorophyll (Chl) fluorescence and pigments of A. vera, a split-plot in time experiment was laid out in a randomized complete block design with four replications in a research greenhouse. The factorial combination of three light intensities (50, 75 and 100% of sunlight) and four irrigation regimes (irrigation after depleting 20, 40, 60 and 80% of soil water content) were considered as main factors. Sampling time was considered as sub factor. The first, second and third samplings were performed 90, 180 and 270 days after imposing the treatments, respectively. The results demonstrated that the highest light intensity and the severe water stress decreased maximum fluorescence (Fm), variable fluorescence (Fv)/Fm, quantum yield of PSII photochemistry (ФPSII), Chl and photochemical quenching (qP) but increased non-photochemical quenching (NPQ), minimum fluorescence (F0) and Anthocyanin (Anth). Additionally, the highest Fm, Fv/Fm, ФPSII and qP and the lowest NPQ and F0 were observed when 50% of sunlight was blocked and irrigation was done after 40% soil water depletion. Irradiance of full sunlight and water deficit stress let to the photoinhibition of photosynthesis, as indicated by a reduced quantum yield of PSII, ФPSII, and qP, as well as higher NPQ. Thus, chlorophyll florescence measurements provide valuable physiological data. Close to half of total solar radiation and irrigation after depleting 40% of soil water content were selected as the most efficient treatments. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  17. Design and validation of a portable, inexpensive and multi-beam timing light system using the Nintendo Wii hand controllers.

    PubMed

    Clark, Ross A; Paterson, Kade; Ritchie, Callan; Blundell, Simon; Bryant, Adam L

    2011-03-01

    Commercial timing light systems (CTLS) provide precise measurement of athletes running velocity, however they are often expensive and difficult to transport. In this study an inexpensive, wireless and portable timing light system was created using the infrared camera in Nintendo Wii hand controllers (NWHC). System creation with gold-standard validation. A Windows-based software program using NWHC to replicate a dual-beam timing gate was created. Firstly, data collected during 2m walking and running trials were validated against a 3D kinematic system. Secondly, data recorded during 5m running trials at various intensities from standing or flying starts were compared to a single beam CTLS and the independent and average scores of three handheld stopwatch (HS) operators. Intraclass correlation coefficient and Bland-Altman plots were used to assess validity. Absolute error quartiles and percentage of trials in absolute error threshold ranges were used to determine accuracy. The NWHC system was valid when compared against the 3D kinematic system (ICC=0.99, median absolute error (MAR)=2.95%). For the flying 5m trials the NWHC system possessed excellent validity and precision (ICC=0.97, MAR<3%) when compared with the CTLS. In contrast, the NWHC system and the HS values during standing start trials possessed only modest validity (ICC<0.75) and accuracy (MAR>8%). A NWHC timing light system is inexpensive, portable and valid for assessing running velocity. Errors in the 5m standing start trials may have been due to erroneous event detection by either the commercial or NWHC-based timing light systems. Copyright © 2010 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  18. Effects of light sources and intensity on broilers grown to heavy weights. Part 1: growth performance, carcass characteristics, and welfare indices

    USDA-ARS?s Scientific Manuscript database

    This study investigated the effects of light sources and light intensity on growth performance, carcass characteristics, and welfare indices of heavy broilers (> 3.0 kg) in 4 trials with 2 replications per trial. A total of 960 1-d-old Ross × Ross 708 chicks (30 males/30 females/room) were randomly ...

  19. Evaluation and Applications of the Prediction of Intensity Model Error (PRIME) Model

    NASA Astrophysics Data System (ADS)

    Bhatia, K. T.; Nolan, D. S.; Demaria, M.; Schumacher, A.

    2015-12-01

    Forecasters and end users of tropical cyclone (TC) intensity forecasts would greatly benefit from a reliable expectation of model error to counteract the lack of consistency in TC intensity forecast performance. As a first step towards producing error predictions to accompany each TC intensity forecast, Bhatia and Nolan (2013) studied the relationship between synoptic parameters, TC attributes, and forecast errors. In this study, we build on previous results of Bhatia and Nolan (2013) by testing the ability of the Prediction of Intensity Model Error (PRIME) model to forecast the absolute error and bias of four leading intensity models available for guidance in the Atlantic basin. PRIME forecasts are independently evaluated at each 12-hour interval from 12 to 120 hours during the 2007-2014 Atlantic hurricane seasons. The absolute error and bias predictions of PRIME are compared to their respective climatologies to determine their skill. In addition to these results, we will present the performance of the operational version of PRIME run during the 2015 hurricane season. PRIME verification results show that it can reliably anticipate situations where particular models excel, and therefore could lead to a more informed protocol for hurricane evacuations and storm preparations. These positive conclusions suggest that PRIME forecasts also have the potential to lower the error in the original intensity forecasts of each model. As a result, two techniques are proposed to develop a post-processing procedure for a multimodel ensemble based on PRIME. The first approach is to inverse-weight models using PRIME absolute error predictions (higher predicted absolute error corresponds to lower weights). The second multimodel ensemble applies PRIME bias predictions to each model's intensity forecast and the mean of the corrected models is evaluated. The forecasts of both of these experimental ensembles are compared to those of the equal-weight ICON ensemble, which currently

  20. An Integrated Response of Trichodesmium erythraeum IMS101 Growth and Photo-Physiology to Iron, CO2, and Light Intensity.

    PubMed

    Boatman, Tobias G; Oxborough, Kevin; Gledhill, Martha; Lawson, Tracy; Geider, Richard J

    2018-01-01

    We have assessed how varying CO 2 (180, 380, and 720 μatm) and growth light intensity (40 and 400 μmol photons m -2 s -1 ) affected Trichodesmium erythraeum IMS101 growth and photophysiology over free iron (Fe') concentrations between 20 and 9,600 pM. We found significant iron dependencies of growth rate and the initial slope and maximal relative PSII electron transport rates (rP m ). Under iron-limiting concentrations, high-light increased growth rates and rP m ; possibly indicating a lower allocation of resources to iron-containing photosynthetic proteins. Higher CO 2 increased growth rates across all iron concentrations, enabled growth to occur at lower Fe' concentrations, increased rP m and lowered the iron half saturation constants for growth (K m ). We attribute these CO 2 responses to the operation of the CCM and the ATP spent/saved for CO 2 uptake and transport at low and high CO 2 , respectively. It seems reasonable to conclude that T. erythraeum IMS101 can exhibit a high degree of phenotypic plasticity in response to CO 2 , light intensity and iron-limitation. These results are important given predictions of increased dissolved CO 2 and water column stratification (i.e., higher light exposures) over the coming decades.

  1. Effect of Different Light Intensities on Total Phenolics and Flavonoids Synthesis and Anti-oxidant Activities in Young Ginger Varieties (Zingiber officinale Roscoe)

    PubMed Central

    Ghasemzadeh, Ali; Jaafar, Hawa Z. E.; Rahmat, Asmah; Wahab, Puteri Edaroyati Megat; Halim, Mohd Ridzwan Abd

    2010-01-01

    Nowadays, phytochemicals and antioxidants in plants are raising interest in consumers for their roles in the maintenance of human health. Phenolics and flavonoids are known for their health-promoting properties due to protective effects against cardiovascular disease, cancers and other disease. Ginger (Zingiber officinale) is one of the traditional folk medicinal plants and it is widely used in cooking in Malaysia. In this study, four levels of glasshouse light intensities (310, 460, 630 and 790 μmol m−2s−1) were used in order to consider the effect of light intensity on the production, accumulation and partitioning of total phenolics (TP), total flavonoids (TF) and antioxidant activities in two varieties of Malaysian young ginger (Zingiber officinale). TF biosynthesis was highest in the Halia Bara variety under 310 μmol m−2s−1 and TP was high in this variety under a light intensity of 790 μmol m−2s−1. The highest amount of these components accumulated in the leaves and after that in the rhizomes. Also, antioxidant activities determined by the 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) assay in both of varieties, increased significantly (p ≤ 0.01) with increasing TF concentration, and high antioxidant activity was observed in the leaves of Halia Bara grown under 310 μmol m−2s−1. The ferric reducing (FRAP) activity of the rhizomes was higher than that of the leaves in 310 μmol m−2s−1 of sun light. This study indicates the ability of different light intensities to enhance the medicinal components and antioxidant activities of the leaves and young rhizomes of Zingiber officinale varieties. Additionally, this study also validated their medicinal potential based on TF and TP contents. PMID:21152306

  2. Effect of different light intensities on total phenolics and flavonoids synthesis and anti-oxidant activities in young ginger varieties (Zingiber officinale Roscoe).

    PubMed

    Ghasemzadeh, Ali; Jaafar, Hawa Z E; Rahmat, Asmah; Wahab, Puteri Edaroyati Megat; Halim, Mohd Ridzwan Abd

    2010-10-12

    Nowadays, phytochemicals and antioxidants in plants are raising interest in consumers for their roles in the maintenance of human health. Phenolics and flavonoids are known for their health-promoting properties due to protective effects against cardiovascular disease, cancers and other disease. Ginger (Zingiber officinale) is one of the traditional folk medicinal plants and it is widely used in cooking in Malaysia. In this study, four levels of glasshouse light intensities (310, 460, 630 and 790 μmol m(-2)s(-1)) were used in order to consider the effect of light intensity on the production, accumulation and partitioning of total phenolics (TP), total flavonoids (TF) and antioxidant activities in two varieties of Malaysian young ginger (Zingiber officinale). TF biosynthesis was highest in the Halia Bara variety under 310 μmol m(-2)s(-1) and TP was high in this variety under a light intensity of 790 μmol m(-2)s(-1). The highest amount of these components accumulated in the leaves and after that in the rhizomes. Also, antioxidant activities determined by the 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) assay in both of varieties, increased significantly (p ≤ 0.01) with increasing TF concentration, and high antioxidant activity was observed in the leaves of Halia Bara grown under 310 μmol m(-2)s(-1). The ferric reducing (FRAP) activity of the rhizomes was higher than that of the leaves in 310 μmol m(-2)s(-1) of sun light. This study indicates the ability of different light intensities to enhance the medicinal components and antioxidant activities of the leaves and young rhizomes of Zingiber officinale varieties. Additionally, this study also validated their medicinal potential based on TF and TP contents.

  3. An evaluation of the accuracy of geomagnetic data obtained from an unattended, automated, quasi-absolute station

    USGS Publications Warehouse

    Herzog, D.C.

    1990-01-01

    A comparison is made of geomagnetic calibration data obtained from a high-sensitivity proton magnetometer enclosed within an orthogonal bias coil system, with data obtained from standard procedures at a mid-latitude U.S. Geological Survey magnetic observatory using a quartz horizontal magnetometer, a Ruska magnetometer, and a total field magnetometer. The orthogonal coil arrangement is used with the proton magnetometer to provide Deflected-Inclination-Deflected-Declination (DIDD) data from which quasi-absolute values of declination, horizontal intensity, and vertical intensity can be derived. Vector magnetometers provide the ordinate values to yield baseline calibrations for both the DIDD and standard observatory processes. Results obtained from a prototype system over a period of several months indicate that the DIDD unit can furnish adequate absolute field values for maintaining observatory calibration data, thus providing baseline control for unattended, remote stations. ?? 1990.

  4. Validation of ozone intensities at 10 μm with THz spectrometry

    NASA Astrophysics Data System (ADS)

    Drouin, Brian J.; Crawford, Timothy J.; Yu, Shanshan

    2017-12-01

    This manuscript reports an effort to improve the absolute accuracy of ozone intensities in the 10 μm region via a transfer of the precision of the rotational dipole moment onto the infrared measurement. The approach determines the ozone mixing ratio through alternately measuring seven pure rotation ozone lines from 692 to 779 GHz. A multispectrum fitting technique was employed. The results determine the column with absolute accuracy of 1.5% and the intensities of infrared transitions measured at this accuracy reproduce the recommended values to within a standard deviation of 2.8%.

  5. Modeling and Validation of Performance Limitations for the Optimal Design of Interferometric and Intensity-Modulated Fiber Optic Displacement Sensors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Moro, Erik A.

    Optical fiber sensors offer advantages over traditional electromechanical sensors, making them particularly well-suited for certain measurement applications. Generally speaking, optical fiber sensors respond to a desired measurand through modulation of an optical signal's intensity, phase, or wavelength. Practically, non-contacting fiber optic displacement sensors are limited to intensity-modulated and interferometric (or phase-modulated) methodologies. Intensity-modulated fiber optic displacement sensors relate target displacement to a power measurement. The simplest intensity-modulated sensor architectures are not robust to environmental and hardware fluctuations, since such variability may cause changes in the measured power level that falsely indicate target displacement. Differential intensity-modulated sensors have been implemented, offeringmore » robustness to such intensity fluctuations, and the speed of these sensors is limited only by the combined speed of the photodetection hardware and the data acquisition system (kHz-MHz). The primary disadvantages of intensity-modulated sensing are the relatively low accuracy (?m-mm for low-power sensors) and the lack of robustness, which consequently must be designed, often with great difficulty, into the sensor's architecture. White light interferometric displacement sensors, on the other hand, offer increased accuracy and robustness. Unlike their monochromatic-interferometer counterparts, white light interferometric sensors offer absolute, unambiguous displacement measurements over large displacement ranges (cm for low-power, 5 mW, sources), necessitating no initial calibration, and requiring no environmental or feedback control. The primary disadvantage of white light interferometric displacement sensors is that their utility in dynamic testing scenarios is limited, both by hardware bandwidth and by their inherent high-sensitivity to Doppler-effects. The decision of whether to use either an intensity

  6. Absolute calibration of optical streak cameras on picosecond time scales using supercontinuum generation

    DOE PAGES

    Patankar, S.; Gumbrell, E. T.; Robinson, T. S.; ...

    2017-08-17

    Here we report a new method using high stability, laser-driven supercontinuum generation in a liquid cell to calibrate the absolute photon response of fast optical streak cameras as a function of wavelength when operating at fastest sweep speeds. A stable, pulsed white light source based around the use of self-phase modulation in a salt solution was developed to provide the required brightness on picosecond timescales, enabling streak camera calibration in fully dynamic operation. The measured spectral brightness allowed for absolute photon response calibration over a broad spectral range (425-650nm). Calibrations performed with two Axis Photonique streak cameras using the Photonismore » P820PSU streak tube demonstrated responses which qualitatively follow the photocathode response. Peak sensitivities were 1 photon/count above background. The absolute dynamic sensitivity is less than the static by up to an order of magnitude. We attribute this to the dynamic response of the phosphor being lower.« less

  7. Light Intensity-Dependent Modulation of Chlorophyll b Biosynthesis and Photosynthesis by Overexpression of Chlorophyllide a Oxygenase in Tobacco1[C][OA

    PubMed Central

    Biswal, Ajaya K.; Pattanayak, Gopal K.; Pandey, Shiv S.; Leelavathi, Sadhu; Reddy, Vanga S.; Govindjee; Tripathy, Baishnab C.

    2012-01-01

    Chlorophyll b is synthesized by the oxidation of a methyl group on the B ring of a tetrapyrrole molecule to a formyl group by chlorophyllide a oxygenase (CAO). The full-length CAO from Arabidopsis (Arabidopsis thaliana) was overexpressed in tobacco (Nicotiana tabacum) that grows well at light intensities much higher than those tolerated by Arabidopsis. This resulted in an increased synthesis of glutamate semialdehyde, 5-aminolevulinic acid, magnesium-porphyrins, and chlorophylls. Overexpression of CAO resulted in increased chlorophyll b synthesis and a decreased chlorophyll a/b ratio in low light-grown as well as high light-grown tobacco plants; this effect, however, was more pronounced in high light. The increased potential of the protochlorophyllide oxidoreductase activity and chlorophyll biosynthesis compensated for the usual loss of chlorophylls in high light. Increased chlorophyll b synthesis in CAO-overexpressed plants was accompanied not only by an increased abundance of light-harvesting chlorophyll proteins but also of other proteins of the electron transport chain, which led to an increase in the capture of light as well as enhanced (40%–80%) electron transport rates of photosystems I and II at both limiting and saturating light intensities. Although the quantum yield of carbon dioxide fixation remained unchanged, the light-saturated photosynthetic carbon assimilation, starch content, and dry matter accumulation increased in CAO-overexpressed plants grown in both low- and high-light regimes. These results demonstrate that controlled up-regulation of chlorophyll b biosynthesis comodulates the expression of several thylakoid membrane proteins that increase both the antenna size and the electron transport rates and enhance carbon dioxide assimilation, starch content, and dry matter accumulation. PMID:22419827

  8. Absolute geomagnetic intensity data from preclassic Guatemalan pottery

    NASA Astrophysics Data System (ADS)

    Alva-Valdivia, L. M.; Morales, J.; Goguitchaichvili, A.; Popenoe de Hatch, M.; Hernandez-Bernal, M. S.; Mariano-Matías, F.

    2010-05-01

    Archaeointensity results from 10 pottery fragments from the Kaminaljuyu area (14°37'N, 90°32'W)—Guatemala, whose ages range from 100 to 900 B.C., were determined in order to contribute to the incipient intensity secular variation curve for the preclassic period in Mesoamerica. Magnetic experiments including hysteresis loops, IRM-DIRM and Curie temperature analysis indicate that pseudo-single-domain magnetite and/or titanium poor titanomagnetites are responsible for the remanence. Pottery fragments were analyzed using the Coe version of the Thellier and Thellier paleointensity method. Although not numerous, our results meet with high standard, commonly accepted strict selection and acceptance criteria as attested by reasonably high Coe quality factors. The fragment mean archaeointensities range from 15 to 43 μT, and corresponding virtual axial dipole moments range from 3.6 ± 0.7 to 10.3 ± 0.9 × 10 22 Am 2. This corresponds to a mean VADM value of (7.5 ± 2.5) × 10 22 Am 2, which is close to the present day field strength. The new results obtained in this study together with those of ArcheoInt data compilation, are analyzed in context of CALS3k and ARCH3K model predictions.

  9. Photothermal effects in phase shifted FBG with varied light wavelength and intensity.

    PubMed

    Ding, Meng; Chen, Dijun; Fang, Zujie; Wang, Di; Zhang, Xi; Wei, Fang; Yang, Fei; Ying, Kang; Cai, Haiwen

    2016-10-31

    The intensity enhancement effect of a phase-shifted fiber Bragg grating (PSFBG) is investigated theoretically and experimentally in this paper. Due to the effect, both of the FBG reflection bands and the transmission peak show red-shift with the increase of pump light wavelength from the shorter side to the longer side of the Bragg wavelength. The transmission peak shifts in pace with the pump's wavelength, which is much faster than the reflection band. The maximum shift increases with the pump power. In contrast, the red-shift is very small when the pump light deceases from the longer side of the Bragg wavelength. Such asymmetric behavior is checked dynamically by using a frequency modulated laser in a serrated wave, showing push-pull behavior. The effect of the characteristics of thermal dissipation conditions is also measured. The fiber loss coefficient of FBG being tested is estimated from the measured data to be about 0.001 mm-1, which may be attributed to the H2-loading and UV exposure in FBG fabrication. The observed phenomena are believed of importance in application where PSFBG is utilized as a narrow linewidth filter.

  10. Spectral irradiance of singly and doubly ionized zinc in low-intensity laser-plasma ultraviolet light sources

    NASA Astrophysics Data System (ADS)

    Szilagyi, John; Parchamy, Homaira; Masnavi, Majid; Richardson, Martin

    2017-01-01

    The absolute spectral irradiances of laser-plasmas produced from planar zinc targets are determined over a wavelength region of 150 to 250 nm. Strong spectral radiation is generated using 60 ns full-width-at-half-maximum, 1.0 μm wavelength laser pulses with incident laser intensities as low as ˜5 × 108 W cm-2. A typical radiation conversion efficiency of ˜2%/2πsr is measured. Numerical calculations using a comprehensive radiation-hydrodynamics model reveal the strong experimental spectra to originate mainly from 3d94s4p-3d94s2, 3d94s4d-3d94s4p, and 3d94p-3d94s, 3d94d-3d94p unresolved-transition arrays in singly and doubly ionized zinc, respectively.

  11. A simple method for correcting spatially resolved solar intensity oscillation observations for variations in scattered light

    NASA Technical Reports Server (NTRS)

    Jefferies, S. M.; Duvall, T. L., Jr.

    1991-01-01

    A measurement of the intensity distribution in an image of the solar disk will be corrupted by a spatial redistribution of the light that is caused by the earth's atmosphere and the observing instrument. A simple correction method is introduced here that is applicable for solar p-mode intensity observations obtained over a period of time in which there is a significant change in the scattering component of the point spread function. The method circumvents the problems incurred with an accurate determination of the spatial point spread function and its subsequent deconvolution from the observations. The method only corrects the spherical harmonic coefficients that represent the spatial frequencies present in the image and does not correct the image itself.

  12. Thermographic analysis of photodynamic therapy with intense pulsed light and needle-free injection photosensitizer delivery: an animal study

    NASA Astrophysics Data System (ADS)

    Requena, Michelle B.; Stringasci, Mirian D.; Pratavieira, Sebastião.; Vollet-Filho, José Dirceu; de Nardi, Andrigo B.; Escobar, Andre; da Rocha, Rozana W.; Bagnato, Vanderlei S.; de Menezes, Priscila F. C.

    2018-02-01

    The photodynamic therapy (PDT) is a therapeutic modality that depends mostly on photosensitizer (PS), light and molecular oxygen species. However, there are still technical limitations in clinical PDT that are under constant development, particularly concerning PS and light delivery. Intense Pulsed Light (IPL) sources are systems able to generate pulses of high energy with polychromatic light. IPL is a technique mainly used in the cosmetic area to perform various skin treatments for therapeutic and aesthetic applications. The goals of this study were to determine temperature variance during the application of IPL in porcine skin model, and the PDT effects using this light source with PS delivery by a commercial high pressure, needle-free injection system. The PSs tested were Indocyanine Green (ICG) and Photodithazine (PDZ), and the results showed an increase bellow 10 °C in the skin surface using a thermographic camera to measure. In conclusion, our preliminary study demonstrated that IPL associated with needle-free injection PS delivery could be a promising alternative to PDT.

  13. Calculating Galactic Distances Through Supernova Light Curve Analysis (Abstract)

    NASA Astrophysics Data System (ADS)

    Glanzer, J.

    2018-06-01

    (Abstract only) The purpose of this project is to experimentally determine the distance to the galaxy M101 by using data that were taken on the type Ia supernova SN 2011fe at the Paul P. Feder Observatory. Type Ia supernovae are useful for determining distances in astronomy because they all have roughly the same luminosity at the peak of their outburst. Comparing the apparent magnitude to the absolute magnitude allows a measurement of the distance. The absolute magnitude is estimated in two ways: using an empirical relationship from the literature between the rate of decline and the absolute magnitude, and using sncosmo, a PYTHON package used for supernova light curve analysis that fits model light curves to the photometric data.

  14. Intense Pulsed Light (IPL) in Aesthetic Dermatology

    NASA Astrophysics Data System (ADS)

    Pytras, B.; Drozdowski, P.; Zub, K.

    2011-08-01

    Introduction. Newer and newer technologies have been widely developed in recent years due to increasing need for aesthetic medicine procedures. Less invasive methods of skin imperfection and time-related lesions removal, IPL (Intense Pulse Light) being one of them, are gaining more and more interest. The shorter the "downtime" for the patient is and the more efficient the procedure results, the more popular the method becomes. Materials and methods_Authors analyse the results of treatment of a 571 patients-group (501 women and 70 men) aged 5-72 years in the period: October 2006-August 2010. IPL™ Quantum (Lumenis Ltd.) device with 560 nm. cut-off filter was used. Results. The results were regarded as: very good, good or satisfying (%):Skin photoaging symptomes 37/40/23, Isolated facial dyschromia 30/55/25, Isolated facial erythema 62/34/4, Lower limbs teleangiectasia 12/36/52, Keratosis solaris on hands 100/-/-. Approximately half of the patients developed transitory erythema and 25%- transitory, mild, circumscribed oedema. Following undesirable effects were noted: skin thermal irritation (6,1% of the patients) and skin hypopigmentation (2% of the patients). Discussion. Results and post-treatment management proposed by authors are similar to those reported by other authors. Conclusions. Treatment results of the 571-patients group prove IPL to be a very efficient method of non-ablative skin rejuvenation. It turned out effective also in lower limbs teleangiectasia treatment. It presents low risk of transitory and mild side effects. Futhermore, with short or no downtime, it is well-tolerated by the patients.

  15. Effect of nitrogen-starvation, light intensity and iron on triacylglyceride/carbohydrate production and fatty acid profile of Neochloris oleoabundans HK-129 by a two-stage process.

    PubMed

    Sun, Xian; Cao, Yu; Xu, Hui; Liu, Yan; Sun, Jianrui; Qiao, Dairong; Cao, Yi

    2014-03-01

    Triacylglyceride (TAG) and carbohydrate are potential feedstock for biofuels production. In this study, a two-stage process was applied for enhancing TAG/carbohydrate production in the selected microalgae - Neochloris oleoabundans HK-129. In stage I, effects of nitrogen, light intensity and iron on cell growth were investigated, and the highest biomass productivity of 292.83±5.83mg/L/d was achieved. In stage II, different nitrogen-starvation periods, light intensities and iron concentrations were employed to trigger accumulation of TAG and carbohydrate. The culture under 2-day N-starvation, 200μmol/m(2)/s light intensity and 0.037mM Fe(3+) concentration produced the maximum TAG and carbohydrate productivity of 51.58mg/L/d and 90.70mg/L/d, respectively. Nitrogen starvation period and light intensity had marked effects on TAG/carbohydrate accumulation and fatty acids profile, compared to iron concentration. The microalgal lipid was mainly composed of C16/C18 fatty acids (90.02%), saturated fatty acids (29.82%), and monounsaturated fatty acids (32.67%), which is suitable for biodiesel synthesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Effects of temperature, salinity, light intensity, and pH on the eicosapentaenoic acid production of Pinguiococcus pyrenoidosus

    NASA Astrophysics Data System (ADS)

    Sang, Min; Wang, Ming; Liu, Jianhui; Zhang, Chengwu; Li, Aifen

    2012-06-01

    The effects of temperature, light intensity, salinity, and initial pH on the growth and fatty acid composition of Pinguiococcus pyrenoidosus 2078 were studied for eicosapentaenoic acid (EPA) production potential. The fatty acid composition was assayed by gas chromatography-mass spectrometry, which indicated that the main fatty acids were C14:0, C16:0 and EPA. The highest EPA percentage 20.83% of total fatty acids was obtained at 20°C with the temperature being set at 20, 24, and 28°C. Under different salinities and light intensities, the highest percentages of total polyunsaturated fatty acids (PUFAs) and EPA were 17.82% and 31.37% of total fatty acids, respectively, which were achieved at salinity 30 and 100 μmol photon m-2s-1 illumination. The highest percentages of total PUFAs and EPA were 38.75% and 23.13% of total fatty acids, respectively, which were reached at an initial pH of 6 with the test range being from 5.0 to 9.0.

  17. Absolute dimensions and masses of eclipsing binaries. V. IQ Persei

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lacy, C.H.; Frueh, M.L.

    1985-08-01

    New photometric and spectroscopic observations of the 1.7 day eclipsing binary IQ Persei (B8 + A6) have been analyzed to yield very accurate fundamental properties of the system. Reticon spectroscopic observations obtained at McDonald Observatory were used to determine accurate radial velocities of both stars in this slightly eccentric large light-ratio binary. A new set of VR light curves obtained at McDonald Observatory were analyzed by synthesis techniques, and previously published UBV light curves were reanalyzed to yield accurate photometric orbits. Orbital parameters derived from both sets of photometric observations are in excellent agreement. The absolute dimensions, masses, luminosities, andmore » apsidal motion period (140 yr) derived from these observations agree well with the predictions of theoretical stellar evolution models. The A6 secondary is still very close to the zero-age main sequence. The B8 primary is about one-third of the way through its main-sequence evolution. 27 references.« less

  18. Light intensity and N/P nutrient affect the accumulation of lipid and unsaturated fatty acids by Chlorella sp.

    PubMed

    Guo, Xiaoyi; Su, Gaomin; Li, Zheng; Chang, Jingyu; Zeng, Xianhai; Sun, Yong; Lu, Yinghua; Lin, Lu

    2015-09-01

    In this study, different light intensities (80, 160, 240 and 320 μmol/m(2) s) and various mediums including control medium (CM), N/P rich medium (NPM), N rich medium (NM), and P rich medium (PM) were applied for cultivation of Chlorella sp. It was revealed that cultivation of Chlorella sp. in CM under the light intensity of 320 μmol/m(2) s led to a lipid content up to 30% enhancement, which was higher than the results of other cases. A rather high unsaturated fatty acid (UFA) content of 7.5% and unsaturated fatty acid/total fatty acid (UFA/TFA) ratio of 0.73 were obtained under 320 μmol/m(2) s in CM, indicating that the CM-320 system was applicable for the generation of UFA. Moreover, Chlorella sp. cultivated in PM under 320 μmol/m(2) s provided higher TFA content (7.3%), which was appropriate for biofuel production. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Photosynthate partitioning to starch in Arabidopsis thaliana is insensitive to light intensity but sensitive to photoperiod due to a restriction on growth in the light in short photoperiods.

    PubMed

    Mengin, Virginie; Pyl, Eva-Theresa; Alexandre Moraes, Thiago; Sulpice, Ronan; Krohn, Nicole; Encke, Beatrice; Stitt, Mark

    2017-11-01

    Photoperiod duration can be predicted from previous days, but irradiance fluctuates in an unpredictable manner. To investigate how allocation to starch responds to changes in these two environmental variables, Arabidopsis Col-0 was grown in a 6 h and a 12 h photoperiod at three different irradiances. The absolute rate of starch accumulation increased when photoperiod duration was shortened and when irradiance was increased. The proportion of photosynthate allocated to starch increased strongly when photoperiod duration was decreased but only slightly when irradiance was decreased. There was a small increase in the daytime level of sucrose and twofold increases in glucose, fructose and glucose 6-phosphate at a given irradiance in short photoperiods compared to long photoperiods. The rate of starch accumulation correlated strongly with sucrose and glucose levels in the light, irrespective of whether these sugars were responding to a change in photoperiod or irradiance. Whole plant carbon budget modelling revealed a selective restriction of growth in the light period in short photoperiods. It is proposed that photoperiod sensing, possibly related to the duration of the night, restricts growth in the light period in short photoperiods, increasing allocation to starch and providing more carbon reserves to support metabolism and growth in the long night. © 2017 John Wiley & Sons Ltd.

  20. Kinetic characteristics and modeling of microalgae Chlorella vulgaris growth and CO2 biofixation considering the coupled effects of light intensity and dissolved inorganic carbon.

    PubMed

    Chang, Hai-Xing; Huang, Yun; Fu, Qian; Liao, Qiang; Zhu, Xun

    2016-04-01

    Understanding and optimizing the microalgae growth process is an essential prerequisite for effective CO2 capture using microalgae in photobioreactors. In this study, the kinetic characteristics of microalgae Chlorella vulgaris growth in response to light intensity and dissolved inorganic carbon (DIC) concentration were investigated. The greatest values of maximum biomass concentration (Xmax) and maximum specific growth rate (μmax) were obtained as 2.303 g L(-1) and 0.078 h(-1), respectively, at a light intensity of 120 μmol m(-2) s(-1) and DIC concentration of 17 mM. Based on the results, mathematical models describing the coupled effects of light intensity and DIC concentration on microalgae growth and CO2 biofixation are proposed. The models are able to predict the temporal evolution of C. vulgaris growth and CO2 biofixation rates from lag to stationary phases. Verification experiments confirmed that the model predictions agreed well with the experimental results. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Low-cost vibration sensor based on dual fiber Bragg gratings and light intensity measurement.

    PubMed

    Gao, Xueqing; Wang, Yongjiao; Yuan, Bo; Yuan, Yinquan; Dai, Yawen; Xu, Gang

    2013-09-20

    A vibration monitoring system based on light intensity measurement has been constructed, and the designed accelerometer is based on steel cantilever frame and dual fiber Bragg gratings (FBGs). By using numerical simulations for the dual FBGs, the dependence relationship of the area of main lobes on the difference of initial central wavelengths is obtained and the most optimal choice for the initial value and the vibration amplitude of the difference of central wavelengths of two FBGs is suggested. The vibration monitoring experiments are finished, and the measured data are identical to the simulated results.

  2. Biological Significance of Photoreceptor Photocycle Length: VIVID Photocycle Governs the Dynamic VIVID-White Collar Complex Pool Mediating Photo-adaptation and Response to Changes in Light Intensity

    PubMed Central

    Dasgupta, Arko; Chen, Chen-Hui; Lee, ChangHwan; Gladfelter, Amy S.; Dunlap, Jay C.; Loros, Jennifer J.

    2015-01-01

    Most organisms on earth sense light through the use of chromophore-bearing photoreceptive proteins with distinct and characteristic photocycle lengths, yet the biological significance of this adduct decay length is neither understood nor has been tested. In the filamentous fungus Neurospora crassa VIVID (VVD) is a critical player in the process of photoadaptation, the attenuation of light-induced responses and the ability to maintain photosensitivity in response to changing light intensities. Detailed in vitro analysis of the photochemistry of the blue light sensing, FAD binding, LOV domain of VVD has revealed residues around the site of photo-adduct formation that influence the stability of the adduct state (light state), that is, altering the photocycle length. We have examined the biological significance of VVD photocycle length to photoadaptation and report that a double substitution mutant (vvdI74VI85V), previously shown to have a very fast light to dark state reversion in vitro, shows significantly reduced interaction with the White Collar Complex (WCC) resulting in a substantial photoadaptation defect. This reduced interaction impacts photoreceptor transcription factor WHITE COLLAR-1 (WC-1) protein stability when N. crassa is exposed to light: The fast-reverting mutant VVD is unable to form a dynamic VVD-WCC pool of the size required for photoadaptation as assayed both by attenuation of gene expression and the ability to respond to increasing light intensity. Additionally, transcription of the clock gene frequency (frq) is sensitive to changing light intensity in a wild-type strain but not in the fast photo-reversion mutant indicating that the establishment of this dynamic VVD-WCC pool is essential in general photobiology and circadian biology. Thus, VVD photocycle length appears sculpted to establish a VVD-WCC reservoir of sufficient size to sustain photoadaptation while maintaining sensitivity to changing light intensity. The great diversity in photocycle

  3. Redox-Dependent Modulation of Anthocyanin Biosynthesis by the TCP Transcription Factor TCP15 during Exposure to High Light Intensity Conditions in Arabidopsis.

    PubMed

    Viola, Ivana L; Camoirano, Alejandra; Gonzalez, Daniel H

    2016-01-01

    TCP proteins integrate a family of transcription factors involved in the regulation of developmental processes and hormone responses. It has been shown that most members of class I, one of the two classes in which the TCP family is divided, contain a conserved Cys that leads to inhibition of DNA binding when oxidized. In this work, we describe that the class-I TCP protein TCP15 inhibits anthocyanin accumulation during exposure of plants to high light intensity by modulating the expression of transcription factors involved in the induction of anthocyanin biosynthesis genes, as suggested by the study of plants that express TCP15 from the 35SCaMV promoter and mutants in TCP15 and the related gene TCP14. In addition, the effect of TCP15 on anthocyanin accumulation is lost after prolonged incubation under high light intensity conditions. We provide evidence that this is due to inactivation of TCP15 by oxidation of Cys-20 of the TCP domain. Thus, redox modulation of TCP15 activity in vivo by high light intensity may serve to adjust anthocyanin accumulation to the duration of exposure to high irradiation conditions. © 2016 American Society of Plant Biologists. All Rights Reserved.

  4. MethyLight droplet digital PCR for detection and absolute quantification of infrequently methylated alleles.

    PubMed

    Yu, Ming; Carter, Kelly T; Makar, Karen W; Vickers, Kathy; Ulrich, Cornelia M; Schoen, Robert E; Brenner, Dean; Markowitz, Sanford D; Grady, William M

    2015-01-01

    Aberrant DNA methylation is a common epigenetic alteration found in colorectal adenomas and cancers and plays a role in cancer initiation and progression. Aberrantly methylated DNA loci can also be found infrequently present in normal colon tissue, where they seem to have potential to be used as colorectal cancer (CRC) risk biomarkers. However, detection and precise quantification of the infrequent methylation events seen in normal colon is likely beyond the capability of commonly used PCR technologies. To determine the potential for methylated DNA loci as CRC risk biomarkers, we developed MethyLight droplet digital PCR (ddPCR) assays and compared their performance to the widely used conventional MethyLight PCR. Our analyses demonstrated the capacity of MethyLight ddPCR to detect a single methylated NTRK3 allele from among more than 3125 unmethylated alleles, 25-fold more sensitive than conventional MethyLight PCR. The MethyLight ddPCR assay detected as little as 19 and 38 haploid genome equivalents of methylated EVL and methylated NTRK3, respectively, which far exceeded conventional MethyLight PCR (379 haploid genome equivalents for both genes). When assessing methylated EVL levels in CRC tissue samples, MethyLight ddPCR reduced coefficients of variation (CV) to 6-65% of CVs seen with conventional MethyLight PCR. Importantly, we showed the ability of MethyLight ddPCR to detect infrequently methylated EVL alleles in normal colon mucosa samples that could not be detected by conventional MethyLight PCR. This study suggests that the sensitivity and precision of methylation detection by MethyLight ddPCR enhances the potential of methylated alleles for use as CRC risk biomarkers.

  5. Intense pulsed light treatment for dry eye disease due to meibomian gland dysfunction; a 3-year retrospective study.

    PubMed

    Toyos, Rolando; McGill, William; Briscoe, Dustin

    2015-01-01

    The purpose of this study was to determine the clinical benefits of intense-pulsed-light therapy for the treatment of dry-eye disease caused by meibomian gland dysfunction (MGD). MGD is the leading cause of evaporative dry eye disease. It is currently treated with a range of methods that have been shown to be only somewhat effective, leading to the need for advanced treatment options. A retrospective noncomparative interventional case series was conducted with 91 patients presenting with severe dry eye syndrome. Treatment included intense-pulsed-light therapy and gland expression at a single outpatient clinic over a 30-month study. Pre/post tear breakup time data were available for a subset of 78 patients. For all patients, a specially developed technique for the treatment of dry eye syndrome was applied as a series of monthly treatments until there was adequate improvement in dry eye syndrome symptoms by physician judgment, or until patient discontinuation. Primary outcomes included change in tear breakup time, self-reported patient satisfaction, and adverse events. Physician-judged improvement in dry eye tear breakup time was found for 68 of 78 patients (87%) with seven treatment visits and four maintenance visits on average (medians), and 93% of patients reported post-treatment satisfaction with degree of dry eye syndrome symptoms. Adverse events, most typically redness or swelling, were found for 13% of patients. No serious adverse events were found. Although preliminary, study results of intense-pulsed-light therapy treatment for dry eye syndrome caused by meibomian gland dysfunction are promising. A multisite clinical trial with a larger sample, treatment comparison groups, and randomized controlled trials is currently underway.

  6. Effect of high wavelengths low intensity light during dark period on physical exercise performance, biochemical and haematological parameters of swimming rats.

    PubMed

    Beck, W; Gobatto, C

    2016-03-01

    Nocturnal rodents should be assessed at an appropriate time of day, which leads to a challenge in identifying an adequate environmental light which allows animal visualisation without perturbing physiological homeostasis. Thus, we analysed the influence of high wavelength and low intensity light during dark period on physical exercise and biochemical and haematological parameters of nocturnal rats. We submitted 80 animals to an exhaustive exercise at individualised intensity under two different illuminations during dark period. Red light (> 600 nm; < 15lux) was applied constantly during dark period (EI; for experimental illumination groups) or only for handling and assessments (SI; for standard illumination groups). EI led to worse haematological and biochemical conditions, demonstrating that EI alone can influence physiological parameters and jeopardise result interpretation. SI promotes normal physiological conditions and greater aerobic tolerance than EI, showing the importance of a correct illumination pattern for all researchers that employ nocturnal rats for health/disease or sports performance experiments.

  7. Estimating the absolute wealth of households.

    PubMed

    Hruschka, Daniel J; Gerkey, Drew; Hadley, Craig

    2015-07-01

    To estimate the absolute wealth of households using data from demographic and health surveys. We developed a new metric, the absolute wealth estimate, based on the rank of each surveyed household according to its material assets and the assumed shape of the distribution of wealth among surveyed households. Using data from 156 demographic and health surveys in 66 countries, we calculated absolute wealth estimates for households. We validated the method by comparing the proportion of households defined as poor using our estimates with published World Bank poverty headcounts. We also compared the accuracy of absolute versus relative wealth estimates for the prediction of anthropometric measures. The median absolute wealth estimates of 1,403,186 households were 2056 international dollars per capita (interquartile range: 723-6103). The proportion of poor households based on absolute wealth estimates were strongly correlated with World Bank estimates of populations living on less than 2.00 United States dollars per capita per day (R(2)  = 0.84). Absolute wealth estimates were better predictors of anthropometric measures than relative wealth indexes. Absolute wealth estimates provide new opportunities for comparative research to assess the effects of economic resources on health and human capital, as well as the long-term health consequences of economic change and inequality.

  8. A portable smart phone-based plasmonic nanosensor readout platform that measures transmitted light intensities of nanosubstrates using an ambient light sensor.

    PubMed

    Fu, Qiangqiang; Wu, Ze; Xu, Fangxiang; Li, Xiuqing; Yao, Cuize; Xu, Meng; Sheng, Liangrong; Yu, Shiting; Tang, Yong

    2016-05-21

    Plasmonic nanosensors may be used as tools for diagnostic testing in the field of medicine. However, quantification of plasmonic nanosensors often requires complex and bulky readout instruments. Here, we report the development of a portable smart phone-based plasmonic nanosensor readout platform (PNRP) for accurate quantification of plasmonic nanosensors. This device operates by transmitting excitation light from a LED through a nanosubstrate and measuring the intensity of the transmitted light using the ambient light sensor of a smart phone. The device is a cylinder with a diameter of 14 mm, a length of 38 mm, and a gross weight of 3.5 g. We demonstrated the utility of this smart phone-based PNRP by measuring two well-established plasmonic nanosensors with this system. In the first experiment, the device measured the morphology changes of triangular silver nanoprisms (AgNPRs) in an immunoassay for the detection of carcinoembryonic antigen (CEA). In the second experiment, the device measured the aggregation of gold nanoparticles (AuNPs) in an aptamer-based assay for the detection of adenosine triphosphate (ATP). The results from the smart phone-based PNRP were consistent with those from commercial spectrophotometers, demonstrating that the smart phone-based PNRP enables accurate quantification of plasmonic nanosensors.

  9. Effects of four dim vs high intensity red color light regimens on growth performance and welfare of broilers.

    PubMed

    Senaratna, D; Samarakone, T S; Gunawardena, W W D A

    2018-01-01

    Broilers show clear preference towards red color light (RL). However setting of an optimum light intensity is difficult since dim intensities that favor growth reduce welfare. This experiment was conducted to test the most effective RL intensity regimen (Dim [5 lux; DI] vs high [320 lux; HI]) in combination applied at different growth stages that favors for both performance and welfare. Complete randomize design was adopted with 6 replicates. Treatments were; T1 = early DI (8-21 d)+latter HI (22-35 d); T2 = early DI (8-28 d)+latter HI (29-35 d), T3 = early HI (8-21 d)+latter DI (22-35 d), T4 = early HI (8-28 d)+latter DI (29-35 d) and T5 = control (white light; WT) (8-35 d) at medium intensity (20 lux). Body weight (BW), weight gain (WG), water/feed intake and ratio, feed conversion ratios (FCR) were assessed. Common behaviours (15) were recorded by scan sampling method. Lameness, foot pad dermatitis, breast blisters, hock burning damage were assessed as welfare parameters. Fear reactions were tested using Tonic Immobility Test. Ocular and carcass evaluations were done. Meat and tibiae were analyzed for fat and bone ash respectively. On 35 d, the highest BW (2,155.72±176 g), WG (1,967.78±174 g) were recorded by T2 compared to WT (BW WT = 1,878.22±155, WG WT = 1,691.83±160). But, application of RL, either DI, or HI during early/latter stage had no significant effect on FCR. Under HI, birds showed much higher active behaviours. DI encourages eating. Though LI changed from DI to HI, same trend could be seen even under HI. The highest leg strength (218.5±120 s) was recorded by T2. The lowest leg strength (64.58±33 s) and the highest ocular weight (2.48±1 g) were recorded by T1. Significantly (p<0.05) the highest skin weight (162.17±6 g) but the lowest fat% in meat (13.03%±5%) was recorded by T2. Early exposure to DI-RL up to 28 days followed by exposure to HI-RL is the most favorable lighting regimen for optimizing production, better welfare of broilers and

  10. Effects of four dim vs high intensity red color light regimens on growth performance and welfare of broilers

    PubMed Central

    Samarakone, T. S.; Gunawardena, W. W. D. A.

    2018-01-01

    Objective Broilers show clear preference towards red color light (RL). However setting of an optimum light intensity is difficult since dim intensities that favor growth reduce welfare. This experiment was conducted to test the most effective RL intensity regimen (Dim [5 lux; DI] vs high [320 lux; HI]) in combination applied at different growth stages that favors for both performance and welfare. Methods Complete randomize design was adopted with 6 replicates. Treatments were; T1 = early DI (8–21 d)+latter HI (22–35 d); T2 = early DI (8–28 d)+latter HI (29–35 d), T3 = early HI (8–21 d)+latter DI (22–35 d), T4 = early HI (8–28 d)+latter DI (29–35 d) and T5 = control (white light; WT) (8–35 d) at medium intensity (20 lux). Body weight (BW), weight gain (WG), water/feed intake and ratio, feed conversion ratios (FCR) were assessed. Common behaviours (15) were recorded by scan sampling method. Lameness, foot pad dermatitis, breast blisters, hock burning damage were assessed as welfare parameters. Fear reactions were tested using Tonic Immobility Test. Ocular and carcass evaluations were done. Meat and tibiae were analyzed for fat and bone ash respectively. Results On 35 d, the highest BW (2,155.72±176 g), WG (1,967.78±174 g) were recorded by T2 compared to WT (BWWT = 1,878.22±155, WGWT = 1,691.83±160). But, application of RL, either DI, or HI during early/latter stage had no significant effect on FCR. Under HI, birds showed much higher active behaviours. DI encourages eating. Though LI changed from DI to HI, same trend could be seen even under HI. The highest leg strength (218.5±120 s) was recorded by T2. The lowest leg strength (64.58±33 s) and the highest ocular weight (2.48±1 g) were recorded by T1. Significantly (p<0.05) the highest skin weight (162.17±6 g) but the lowest fat% in meat (13.03%±5%) was recorded by T2. Conclusion Early exposure to DI-RL up to 28 days followed by exposure to HI-RL is the most favorable lighting regimen for

  11. Interactive effects of photoperiod and light intensity on blood physiological and biochemical reactions of broilers grown to heavy weights

    USDA-ARS?s Scientific Manuscript database

    The effects of photoperiod, light intensity, and their interaction on blood acid-base balance, metabolites, and electrolytes in broiler chickens under environmentally controlled conditions were examined in 2 trials. The experiment was consisted of a factorial arrangement of treatments in a randomize...

  12. Effect of varying light intensity on growth performance and carcass characteristics of broiler chickens grown to heavy weights

    USDA-ARS?s Scientific Manuscript database

    This study investigated effects of varying levels of light intensities (25, 10, 5, 2.5, and 0.2 lx) on growth performance and carcass characteristics of broiler chickens grown to heavy weights. Four identical trials were conducted with two replications per trial. In each trial, 600 1-d-old Ross 308 ...

  13. 14 CFR 27.1389 - Position light distribution and intensities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... minimum intensities in the horizontal plane, minimum intensities in any vertical plane, and maximum...: (1) Intensities in the horizontal plane. Each intensity in the horizontal plane (the plane containing the longitudinal axis of the rotorcraft and perpendicular to the plane of symmetry of the rotorcraft...

  14. Ab initio calculation of infrared intensities for hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Rogers, J. D.; Hillman, J. J.

    1982-01-01

    Results of an ab initio SCF quantum mechanical study are used to derive estimates for the infrared intensities of the fundamental vibrations of hydrogen peroxide. Atomic polar tensors (APTs) were calculated on the basis of a 4-31G basis set, and used to derive absolute intensities for the vibrational transitions. Comparison of the APTs calculated for H2O2 with those previously obtained for H2O and CH3OH, and of the absolute intensities derived from the H2O2 APTs with those derived from APTs transferred from H2O and CH3OH, reveals the sets of values to differ by no more than a factor of two, supporting the validity of the theoretical calculation. Values of the infrared intensities obtained correspond to A1 = 14.5 km/mol, A2 = 0.91 km/mol, A3 = 0.058 km/mol, A4 = 123 km/mol, A5 = 46.2 km/mol, and A6 = 101 km/mol. Charge, charge flux and overlap contributions to the dipole moment derivatives are also computed.

  15. Ab initio calculation of infrared intensities for hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Rogers, J. D.; Hillman, J. J.

    1982-04-01

    Results of an ab initio SCF quantum mechanical study are used to derive estimates for the infrared intensities of the fundamental vibrations of hydrogen peroxide. Atomic polar tensors (APTs) were calculated on the basis of a 4-31G basis set, and used to derive absolute intensities for the vibrational transitions. Comparison of the APTs calculated for H2O2 with those previously obtained for H2O and CH3OH, and of the absolute intensities derived from the H2O2 APTs with those derived from APTs transferred from H2O and CH3OH, reveals the sets of values to differ by no more than a factor of two, supporting the validity of the theoretical calculation. Values of the infrared intensities obtained correspond to A1 = 14.5 km/mol, A2 = 0.91 km/mol, A3 = 0.058 km/mol, A4 = 123 km/mol, A5 = 46.2 km/mol, and A6 = 101 km/mol. Charge, charge flux and overlap contributions to the dipole moment derivatives are also computed.

  16. 14 CFR 29.1389 - Position light distribution and intensities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... terms of minimum intensities in the horizontal plane, minimum intensities in any vertical plane, and... requirements: (1) Intensities in the horizontal plane. Each intensity in the horizontal plane (the plane containing the longitudinal axis of the rotorcraft and perpendicular to the plane of symmetry of the...

  17. 14 CFR 25.1389 - Position light distribution and intensities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... minimum intensities in the horizontal plane, minimum intensities in any vertical plane, and maximum...: (1) Intensities in the horizontal plane. Each intensity in the horizontal plane (the plane containing the longitudinal axis of the airplane and perpendicular to the plane of symmetry of the airplane) must...

  18. Influence of iron precipitated condition and light intensity on microalgae activated sludge based wastewater remediation.

    PubMed

    Anbalagan, Anbarasan; Schwede, Sebastian; Lindberg, Carl-Fredrik; Nehrenheim, Emma

    2017-02-01

    The indigenous microalgae-activated sludge (MAAS) process during remediation of municipal wastewater was investigated by studying the influence of iron flocculation step and light intensity. In addition, availability of total phosphorous (P) and photosynthetic activity was examined in fed-batch and batch mode under northern climatic conditions and limited lighting. This was followed by a semi-continuous operation with 4 d of hydraulic retention time and mean cell residence time of 6.75 d in a photo-bioreactor (PBR) with varying P availability. The fed-batch condition showed that P concentrations of 3-4 mg L -1 were effective for photosynthetic chl. a development in iron flocculated conditions. In the PBR, the oxygen evolution rate increased with increase in the concentration of MAAS (from 258 to 573 mg TSS L -1 ) at higher surface photosynthetic active radiation (250 and 500 μmol m -2 s -1 ). Additionally, the rate approached a saturation phase at low MAAS (110 mg L -1 ) with higher light intensities. Semi-continuous operation with luxury P uptake and effective P condition showed stable average total nitrogen removal of 88 and 92% respectively, with residual concentrations of 3.77 and 2.21 mg L -1 . The corresponding average P removal was 68 and 59% with residual concentrations of 2.32 and 1.75 mg L -1 . The semi-continuous operation produced a rapidly settleable MAAS under iron flocculated condition with a settling velocity of 92-106 m h -1 and sludge volume index of 31-43 ml g -1 in the studied cases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Absolute calibration of a charge-coupled device camera with twin beams

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Meda, A.; Ruo-Berchera, I., E-mail: i.ruoberchera@inrim.it; Degiovanni, I. P.

    2014-09-08

    We report on the absolute calibration of a Charge-Coupled Device (CCD) camera by exploiting quantum correlation. This method exploits a certain number of spatial pairwise quantum correlated modes produced by spontaneous parametric-down-conversion. We develop a measurement model accounting for all the uncertainty contributions, and we reach the relative uncertainty of 0.3% in low photon flux regime. This represents a significant step forward for the characterization of (scientific) CCDs used in mesoscopic light regime.

  20. Comparison of laser and intense pulsed light sintering (IPL) for inkjet-printed copper nanoparticle layers

    PubMed Central

    Niittynen, Juha; Sowade, Enrico; Kang, Hyunkyoo; Baumann, Reinhard R.; Mäntysalo, Matti

    2015-01-01

    In this contribution we discuss the sintering of an inkjet-printed copper nanoparticle ink based on electrical performance and microstructure analysis. Laser and intense pulsed light (IPL) sintering are employed in order to compare the different techniques and their feasibility for electronics manufacturing. A conductivity of more than 20% of that of bulk copper material has been obtained with both sintering methods. Laser and IPL sintering techniques are considered to be complementary techniques and are highly suitable in different application fields. PMID:25743631

  1. Self-Referenced Method for Estimating Refractive Index and Absolute Absorption of Loose Semiconductor Powders

    DOE PAGES

    Huang, Huafeng; Colabello, Diane M.; Sklute, Elizabeth C.; ...

    2017-04-23

    The absolute absorption coefficient, α(E), is a critical design parameter for devices using semiconductors for light harvesting associated with renewable energy production, both for classic technologies such as photovoltaics and for emerging technologies such as direct solar fuel production. While α(E) is well-known for many classic simple semiconductors used in photovoltaic applications, the absolute values of α(E) are typically unknown for the complex semiconductors being explored for solar fuel production due to the absence of single crystals or crystalline epitaxial films that are needed for conventional methods of determining α(E). In this work, a simple self-referenced method for estimating bothmore » the refractive indices, n(E), and absolute absorption coefficients, α(E), for loose powder samples using diffuse reflectance data is demonstrated. In this method, the sample refractive index can be deduced by refining n to maximize the agreement between the relative absorption spectrum calculated from bidirectional reflectance data (calculated through a Hapke transform which depends on n) and integrating sphere diffuse reflectance data (calculated through a Kubleka–Munk transform which does not depend on n). This new method can be quickly used to screen the suitability of emerging semiconductor systems for light-harvesting applications. The effectiveness of this approach is tested using the simple classic semiconductors Ge and Fe 2O 3 as well as the complex semiconductors La 2MoO 5 and La 4Mo 2O 11. The method is shown to work well for powders with a narrow size distribution (exemplified by Fe 2O 3) and to be ineffective for semiconductors with a broad size distribution (exemplified by Ge). As such, it provides a means for rapidly estimating the absolute optical properties of complex solids which are only available as loose powders.« less

  2. Measurement of the absolute reflectance of polytetrafluoroethylene (PTFE) immersed in liquid xenon

    NASA Astrophysics Data System (ADS)

    Neves, F.; Lindote, A.; Morozov, A.; Solovov, V.; Silva, C.; Bras, P.; Rodrigues, J. P.; Lopes, M. I.

    2017-01-01

    The performance of a detector using liquid xenon (LXe) as a scintillator is strongly dependent on the collection efficiency for xenon scintillation light, which in turn is critically dependent on the reflectance of the surfaces that surround the active volume. To improve the light collection in such detectors the active volume is usually surrounded by polytetrafluoroethylene (PTFE) reflector panels, used due to its very high reflectance—even at the short wavelength of scintillation light of LXe (peaked at 178 nm). In this work, which contributed to the overall R&D effort towards the LUX-ZEPLIN (LZ) experiment, we present experimental results for the absolute reflectance measurements of three different PTFE samples (including the material used in the LUX detector) immersed in LXe for its scintillation light. The obtained results show that very high bi-hemispherical reflectance values (>= 97%) can be achieved, enabling very low energy thresholds in liquid xenon scintillator-based detectors.

  3. Estimating the absolute wealth of households

    PubMed Central

    Gerkey, Drew; Hadley, Craig

    2015-01-01

    Abstract Objective To estimate the absolute wealth of households using data from demographic and health surveys. Methods We developed a new metric, the absolute wealth estimate, based on the rank of each surveyed household according to its material assets and the assumed shape of the distribution of wealth among surveyed households. Using data from 156 demographic and health surveys in 66 countries, we calculated absolute wealth estimates for households. We validated the method by comparing the proportion of households defined as poor using our estimates with published World Bank poverty headcounts. We also compared the accuracy of absolute versus relative wealth estimates for the prediction of anthropometric measures. Findings The median absolute wealth estimates of 1 403 186 households were 2056 international dollars per capita (interquartile range: 723–6103). The proportion of poor households based on absolute wealth estimates were strongly correlated with World Bank estimates of populations living on less than 2.00 United States dollars per capita per day (R2 = 0.84). Absolute wealth estimates were better predictors of anthropometric measures than relative wealth indexes. Conclusion Absolute wealth estimates provide new opportunities for comparative research to assess the effects of economic resources on health and human capital, as well as the long-term health consequences of economic change and inequality. PMID:26170506

  4. Optimum projection pattern generation for grey-level coded structured light illumination systems

    NASA Astrophysics Data System (ADS)

    Porras-Aguilar, Rosario; Falaggis, Konstantinos; Ramos-Garcia, Ruben

    2017-04-01

    Structured light illumination (SLI) systems are well-established optical inspection techniques for noncontact 3D surface measurements. A common technique is multi-frequency sinusoidal SLI that obtains the phase map at various fringe periods in order to estimate the absolute phase, and hence, the 3D surface information. Nevertheless, multi-frequency SLI systems employ multiple measurement planes (e.g. four phase shifted frames) to obtain the phase at a given fringe period. It is therefore an age old challenge to obtain the absolute surface information using fewer measurement frames. Grey level (GL) coding techniques have been developed as an attempt to reduce the number of planes needed, because a spatio-temporal GL sequence employing p discrete grey-levels and m frames has the potential to unwrap up to pm fringes. Nevertheless, one major disadvantage of GL based SLI techniques is that there are often errors near the border of each stripe, because an ideal stepwise intensity change cannot be measured. If the step-change in intensity is a single discrete grey-level unit, this problem can usually be overcome by applying an appropriate threshold. However, severe errors occur if the intensity change at the border of the stripe exceeds several discrete grey-level units. In this work, an optimum GL based technique is presented that generates a series of projection patterns with a minimal gradient in the intensity. It is shown that when using this technique, the errors near the border of the stripes can be significantly reduced. This improvement is achieved with the choice generated patterns, and does not involve additional hardware or special post-processing techniques. The performance of that method is validated using both simulations and experiments. The reported technique is generic, works with an arbitrary number of frames, and can employ an arbitrary number of grey-levels.

  5. Absolute and geometric parameters of contact binary BO Arietis

    NASA Astrophysics Data System (ADS)

    Gürol, B.; Gürsoytrak, S. H.; Bradstreet, D. H.

    2015-08-01

    We present the results of our investigation on the geometrical and physical parameters of the W UMa type binary system BO Ari from analyzed CCD (BVRI) light curves and radial velocity data. The photometric data were obtained in 2009 and 2010 at Ankara University Observatory (AUO) and the spectroscopic observations were made in 2007 and 2010 at TUBITAK National Observatory (TUG). These light and radial velocity observations were analyzed simultaneously by using the Wilson-Devinney (2013 revision) code to obtain absolute and geometrical parameters. The system was determined to be an A-type W UMa system. Combining our photometric solution with the spectroscopic data we derived masses and radii of the eclipsing system to be M1 = 0.995M⊙,M2 = 0.189M⊙,R1 = 1.090R⊙ and R2 = 0.515R⊙ . Finally, we discuss the evolutionary status of the system.

  6. Estimating Accuracy at Exercise Intensities: A Comparative Study of Self-Monitoring Heart Rate and Physical Activity Wearable Devices

    PubMed Central

    Dooley, Erin E; Golaszewski, Natalie M

    2017-01-01

    Background Physical activity tracking wearable devices have emerged as an increasingly popular method for consumers to assess their daily activity and calories expended. However, whether these wearable devices are valid at different levels of exercise intensity is unknown. Objective The objective of this study was to examine heart rate (HR) and energy expenditure (EE) validity of 3 popular wrist-worn activity monitors at different exercise intensities. Methods A total of 62 participants (females: 58%, 36/62; nonwhite: 47% [13/62 Hispanic, 8/62 Asian, 7/62 black/ African American, 1/62 other]) wore the Apple Watch, Fitbit Charge HR, and Garmin Forerunner 225. Validity was assessed using 2 criterion devices: HR chest strap and a metabolic cart. Participants completed a 10-minute seated baseline assessment; separate 4-minute stages of light-, moderate-, and vigorous-intensity treadmill exercises; and a 10-minute seated recovery period. Data from devices were compared with each criterion via two-way repeated-measures analysis of variance and Bland-Altman analysis. Differences are expressed in mean absolute percentage error (MAPE). Results For the Apple Watch, HR MAPE was between 1.14% and 6.70%. HR was not significantly different at the start (P=.78), during baseline (P=.76), or vigorous intensity (P=.84); lower HR readings were measured during light intensity (P=.03), moderate intensity (P=.001), and recovery (P=.004). EE MAPE was between 14.07% and 210.84%. The device measured higher EE at all stages (P<.01). For the Fitbit device, the HR MAPE was between 2.38% and 16.99%. HR was not significantly different at the start (P=.67) or during moderate intensity (P=.34); lower HR readings were measured during baseline, vigorous intensity, and recovery (P<.001) and higher HR during light intensity (P<.001). EE MAPE was between 16.85% and 84.98%. The device measured higher EE at baseline (P=.003), light intensity (P<.001), and moderate intensity (P=.001). EE was not

  7. Estimating Accuracy at Exercise Intensities: A Comparative Study of Self-Monitoring Heart Rate and Physical Activity Wearable Devices.

    PubMed

    Dooley, Erin E; Golaszewski, Natalie M; Bartholomew, John B

    2017-03-16

    Physical activity tracking wearable devices have emerged as an increasingly popular method for consumers to assess their daily activity and calories expended. However, whether these wearable devices are valid at different levels of exercise intensity is unknown. The objective of this study was to examine heart rate (HR) and energy expenditure (EE) validity of 3 popular wrist-worn activity monitors at different exercise intensities. A total of 62 participants (females: 58%, 36/62; nonwhite: 47% [13/62 Hispanic, 8/62 Asian, 7/62 black/ African American, 1/62 other]) wore the Apple Watch, Fitbit Charge HR, and Garmin Forerunner 225. Validity was assessed using 2 criterion devices: HR chest strap and a metabolic cart. Participants completed a 10-minute seated baseline assessment; separate 4-minute stages of light-, moderate-, and vigorous-intensity treadmill exercises; and a 10-minute seated recovery period. Data from devices were compared with each criterion via two-way repeated-measures analysis of variance and Bland-Altman analysis. Differences are expressed in mean absolute percentage error (MAPE). For the Apple Watch, HR MAPE was between 1.14% and 6.70%. HR was not significantly different at the start (P=.78), during baseline (P=.76), or vigorous intensity (P=.84); lower HR readings were measured during light intensity (P=.03), moderate intensity (P=.001), and recovery (P=.004). EE MAPE was between 14.07% and 210.84%. The device measured higher EE at all stages (P<.01). For the Fitbit device, the HR MAPE was between 2.38% and 16.99%. HR was not significantly different at the start (P=.67) or during moderate intensity (P=.34); lower HR readings were measured during baseline, vigorous intensity, and recovery (P<.001) and higher HR during light intensity (P<.001). EE MAPE was between 16.85% and 84.98%. The device measured higher EE at baseline (P=.003), light intensity (P<.001), and moderate intensity (P=.001). EE was not significantly different at vigorous (P=.70

  8. Misconceptions in recent papers on special relativity and absolute space theories

    NASA Technical Reports Server (NTRS)

    Torr, D. G.; Kolen, P.

    1982-01-01

    Several recent papers which purport to substantiate or negate arguments in favor of certain theories of absolute space have been based on fallacious principles. This paper discusses three related instances, indicating where misconceptions have arisen. It is established, contrary to popular belief, that the classical Lorentz ether theory accounts for all the experimental evidence which supports the special theory of relativity. It is demonstrated that the ether theory predicts the null results obtained from pulsar timing and Moessbauer experiments. It is concluded that a measurement of the one-way velocity of light has physical meaning within the context of the Lorentz theory, and it is argued that an adequately designed experiment to measure the one-way velocity of light should be attempted.

  9. Method and apparatus for measuring the intensity and phase of one or more ultrashort light pulses and for measuring optical properties of materials

    DOEpatents

    Trebino, Rick P.; DeLong, Kenneth W.

    1996-01-01

    The intensity and phase of one or more ultrashort light pulses are obtained using a non-linear optical medium. Information derived from the light pulses is also used to measure optical properties of materials. Various retrieval techniques are employed. Both "instantaneously" and "non-instantaneously" responding optical mediums may be used.

  10. Effects of Light Quality and Intensity on Diurnal Patterns and Rates of Photo-Assimilate Translocation and Transpiration in Tomato Leaves.

    PubMed

    Lanoue, Jason; Leonardos, Evangelos D; Grodzinski, Bernard

    2018-01-01

    Translocation of assimilates is a fundamental process involving carbon and water balance affecting source/sink relationships. Diurnal patterns of CO 2 exchange, translocation (carbon export), and transpiration of an intact tomato source leaf were determined during 14 CO 2 steady-state labeling under different wavelengths at three pre-set photosynthetic rates. Daily patterns showed that photosynthesis and export were supported by all wavelengths of light tested including orange and green. Export in the light, under all wavelengths was always higher than that at night. Export in the light varied from 65-83% of the total daily carbon fixed, depending on light intensity. Photosynthesis and export were highly correlated under all wavelengths ( r = 0.90-0.96). Export as a percentage of photosynthesis (relative export) decreased as photosynthesis increased by increasing light intensity under all wavelengths. These data indicate an upper limit for export under all spectral conditions. Interestingly, only at the medium photosynthetic rate, relative export under the blue and the orange light-emitting diodes (LEDs) were higher than under white and red-white LEDs. Stomatal conductance, transpiration rates, and water-use-efficiency showed similar daily patterns under all wavelengths. Illuminating tomato leaves with different spectral quality resulted in similar carbon export rates, but stomatal conductance and transpiration rates varied due to wavelength specific control of stomatal function. Thus, we caution that the link between transpiration and C-export may be more complex than previously thought. In summary, these data indicate that orange and green LEDs, not simply the traditionally used red and blue LEDs, should be considered and tested when designing lighting systems for optimizing source leaf strength during plant production in controlled environment systems. In addition, knowledge related to the interplay between water and C-movement within a plant and how they are

  11. 20 CFR 404.1205 - Absolute coverage groups.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Absolute coverage groups. 404.1205 Section... Covered § 404.1205 Absolute coverage groups. (a) General. An absolute coverage group is a permanent... are not under a retirement system. An absolute coverage group may include positions which were...

  12. Laser Plasma Instability (LPI) Driven Light Scattering Measurements with Nike KrF Laser

    NASA Astrophysics Data System (ADS)

    Oh, J.; Weaver, J. L.; Kehne, D. M.; Obenschain, S. P.; McLean, E. A.; Lehmberg, R. H.

    2008-11-01

    With the short wavelength (248 nm), large bandwidth (1˜2 THz), and ISI beam smoothing, Nike KrF laser is expected to have higher LPI thresholds than observed at other laser facilities. Previous measurements using the Nike laser [J. L. Weaver et al, Phys. Plasmas 14, 056316 (2007)] showed no LPI evidence from CH targets up to I˜2x10^15 W/cm^2. For further experiments to detect LPI excitation, Nike capabilities have been extended to achieve higher laser intensities by tighter beam focusing and higher power pulses. This talk will present results of a recent LPI experiment with the extended Nike capabilities focusing on light emission data in spectral ranges relevant to the Raman (SRS) and Two-Plasmon Decay (TPD) instabilities. The primary diagnostics were time-resolved spectrometers with an absolute-intensity-calibrated photodiode array in (0.4˜0.8)φ0 and a streak camera near 0.5φ0. The measurements were conducted at laser intensities of 10^15˜10^16 W/cm^2 on planar targets of CH solids and RF foams.

  13. Adaptability of free-floating green tide algae in the Yellow Sea to variable temperature and light intensity.

    PubMed

    Cui, Jianjun; Zhang, Jianheng; Huo, Yuanzi; Zhou, Lingjie; Wu, Qing; Chen, Liping; Yu, Kefeng; He, Peimin

    2015-12-30

    In this study, the influence of temperature and light intensity on the growth of seedlings and adults of four species of green tide algae (Ulvaprolifera, Ulvacompressa, Ulva flexuosa and Ulvalinza) from the Yellow Sea was evaluated. The results indicated that the specific growth rate (SGR) of seedlings was much higher than that of adults for the four species. The adaptability of U. prolifera is much wider: Adult daily SGRs were the highest among the four species at 15-20 °C with 10-600 μmol · m(-2) · s(-1) and 25-30 °C with 200-600 μmol · m(-2) · s(-1). SGRs were 1.5-3.5 times greater than the other three species at 15-25 °C with 200-600 μmol · m(-2) · s(-1). These results indicate that U. prolifera has better tolerance to high temperature and light intensity than the other three species, which may in part explain why only U. prolifera undergoes large-scale outbreaks and floats to the Qingdao coast while the other three species decline and disappear at the early stage of blooming. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. SenseWearMini and Actigraph GT3X Accelerometer Classification of Observed Sedentary and Light-Intensity Physical Activities in a Laboratory Setting.

    PubMed

    Feehan, Lynne M; Goldsmith, Charles H; Leung, April Y F; Li, Linda C

    Purpose: To compare the ability of SenseWear Mini (SWm) and Actigraph GT3X (AG 3 ) accelerometers to differentiate between healthy adults' observed sedentary and light activities in a laboratory setting. Methods: The 22 participants (15 women, 7 men), ages 19 to 72 years, wore SWm and AG 3 monitors and performed five sedentary and four light activities for 5 minutes each while observed in a laboratory setting. Performance was examined through comparisons of accuracy, sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios. Correct identification of both types of activities was examined using area under the receiver operating characteristic curve (AUC). Results: Both monitors demonstrated excellent ability to identify sedentary activities (sensitivity>0.89). The SWm monitor was better at identifying light activities (specificity 0.61-0.71) than the AG 3 monitor (specificity 0.27-0.47) and thus also showed a greater ability to correctly identify both sedentary and light activities (SWm AUC 0.84; AG 3 AUC 0.62-0.73). Conclusions: SWm may be a more suitable monitor for detecting time spent in sedentary and light-intensity activities. This finding has clinical and research relevance for evaluation of time spent in lower intensity physical activities by sedentary adults.

  15. Absolute versus relative ascertainment of pedophilia in men.

    PubMed

    Blanchard, Ray; Kuban, Michael E; Blak, Thomas; Cantor, James M; Klassen, Philip E; Dickey, Robert

    2009-12-01

    There are at least two different criteria for assessing pedophilia in men: absolute ascertainment (their sexual interest in children is intense) and relative ascertainment (their sexual interest in children is greater than their interest in adults). The American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, 3rd edition (DSM-III) used relative ascertainment in its diagnostic criteria for pedophilia; this was abandoned and replaced by absolute ascertainment in the DSM-III-R and all subsequent editions. The present study was conducted to demonstrate the continuing need for relative ascertainment, particularly in the laboratory assessment of pedophilia. A total of 402 heterosexual men were selected from a database of patients referred to a specialty clinic. These had undergone phallometric testing, a psychophysiological procedure in which their penile blood volume was monitored while they were presented with a standardized set of laboratory stimuli depicting male and female children, pubescents, and adults.The 130 men selected for the Teleiophilic Profile group responded substantially to prepubescent girls but even more to adult women; the 272 men selected for the Pedophilic Profile group responded weakly to prepubescent girls but even less to adult women. In terms of absolute magnitude, every patient in the Pedophilic Profile group had a lesser penile response to prepubescent girls than every patient in the Teleiophilic Profile group. Nevertheless, the Pedophilic Profile group had a significantly greater number of known sexual offenses against prepubescent girls, indicating that they contained a higher proportion of true pedophiles. These results dramatically demonstrate the utility-or perhaps necessity-of relative ascertainment in the laboratory assessment of erotic age-preference.

  16. Synergistic effects of abiotic stresses in plants: a case study of nitrogen limitation and saturating light intensity in Arabidopsis thaliana.

    PubMed

    Cohen, Itay; Rapaport, Tal; Chalifa-Caspi, Vered; Rachmilevitch, Shimon

    2018-05-22

    Under natural conditions, plants are regularly exposed to combinations of stress factors. A common example is the conjunction between nitrogen (N) deficiency and excess light. The combined effect of stress factors is often ignored in studies using controlled conditions, possibly resulting in misleading conclusions. To address this issue, the current study examined the physiological behavior of Arabidopsis thaliana under the effect of varying nitrogen levels and light intensities. The joint influence of low N and excess light had an adverse effect on plant growth, chlorophyll and anthocyanin concentrations, photochemical capacity, and the abundance of proteins involved in carbon assimilation and anti-oxidative metabolism. In contrast, no adverse physiological responses were observed for plants under either nitrogen limitation or high light intensity conditions (i.e., single stress). The underline mechanisms for the increased growth in conditions of high light and sufficient nitrogen was due to a combination of chlorophyll accumulation and an increased number of proteins involved in C3 carbon assimilation, amino acids biosynthesis and chloroplast development. In contrast, combined stress conditions caused anthocyanin accumulation and increased number proteins involved in catabolism of lipids and amino acids as energy substrates. Ultimately switching plants from growth to survival. Our results suggest that an assessment of the physiological response to the combined effect of multiple stresses cannot be directly extrapolated from the physiological response to a single stress. Specifically, the synergistic interaction between N deficiency and saturating light in Arabidopsis plants could not have been modeled via only one of the stress factors. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  17. Determination of eye safety filter protection factors associated with retinal thermal hazard and blue light photochemical hazard for intense pulsed light sources.

    PubMed

    Clarkson, D McG

    2006-02-21

    An assessment is provided of protection factors afforded for retinal thermal hazard and blue light photochemical hazard for a range of filters used with intense pulsed light sources (IPLs). A characteristic IPL spectrum based on black body radiation at 5000 K with a low cut filter at 515 nm was identified as suitable for such estimations. Specific filters assessed included types with idealized transmission properties and also a range of types whose transmission characteristics were measured by means of a Bentham DMc150 spectroradiometer. Predicted behaviour based on these spectra is outlined which describes both the effectiveness of protection and the level of luminous transmittance afforded. The analysis showed it was possible to describe a figure of merit for a particular filter material relating the degree of protection provided and corresponding value of luminous transmittance. This consideration is important for providing users of IPL equipment with safety eyewear with adequate level of visual transmittance.

  18. Effect of inhomogeneity of light from light curing units on the surface hardness of composite resin.

    PubMed

    Arikawa, Hiroyuki; Kanie, Takahito; Fujii, Koichi; Takahashi, Hideo; Ban, Seiji

    2008-01-01

    This study investigated the characteristics of output light from different types of light curing units, and their effects on polymerization of light-activated composite resin. Three quartz-tungsten-halogen lamps, one plasma arc lamp, and one LED light curing unit were used. Intensity distribution of light emitted from the light guide tip was measured at 1.0-mm intervals across the guide tip. Distribution of Knoop hardness number on the surface of resin irradiated with the light curing units was also measured. For all units, inhomogeneous distribution of light intensity across the guide tip was observed. Minimum light intensity values were 19-80% of the maximum values. In terms of surface hardness, inhomogeneous distribution was also observed for the materials irradiated with the tested units. Minimum values were 53-92% of the maximum values. Our results indicated that markedly inhomogeneous light emitted from light curing unit could result in inhomogeneous polymerization in some areas of the restoration below the light guide tip.

  19. Method and apparatus for making absolute range measurements

    DOEpatents

    Allison, Stephen W.; Cates, Michael R.; Key, William S.; Sanders, Alvin J.; Earl, Dennis D.

    1999-01-01

    This invention relates to a method and apparatus for making absolute distance or ranging measurements using Fresnel diffraction. The invention employs a source of electromagnetic radiation having a known wavelength or wavelength distribution, which sends a beam of electromagnetic radiation through an object which causes it to be split (hereinafter referred to as a "beamsplitter"), and then to a target. The beam is reflected from the target onto a screen containing an aperture spaced a known distance from the beamsplitter. The aperture is sized so as to produce a Fresnel diffraction pattern. A portion of the beam travels through the aperture to a detector, spaced a known distance from the screen. The detector detects the central intensity of the beam. The distance from the object which causes the beam to be split to the target can then be calculated based upon the known wavelength, aperture radius, beam intensity, and distance from the detector to the screen. Several apparatus embodiments are disclosed for practicing the method embodiments of the present invention.

  20. Method and apparatus for making absolute range measurements

    DOEpatents

    Allison, S.W.; Cates, M.R.; Key, W.S.; Sanders, A.J.; Earl, D.D.

    1999-06-22

    This invention relates to a method and apparatus for making absolute distance or ranging measurements using Fresnel diffraction. The invention employs a source of electromagnetic radiation having a known wavelength or wavelength distribution, which sends a beam of electromagnetic radiation through an object which causes it to be split (hereinafter referred to as a beam splitter''), and then to a target. The beam is reflected from the target onto a screen containing an aperture spaced a known distance from the beam splitter. The aperture is sized so as to produce a Fresnel diffraction pattern. A portion of the beam travels through the aperture to a detector, spaced a known distance from the screen. The detector detects the central intensity of the beam. The distance from the object which causes the beam to be split to the target can then be calculated based upon the known wavelength, aperture radius, beam intensity, and distance from the detector to the screen. Several apparatus embodiments are disclosed for practicing the method embodiments of the present invention. 9 figs.

  1. [Sound improves distinction of low intensities of light in the visual cortex of a rabbit].

    PubMed

    Polianskiĭ, V B; Alymkulov, D E; Evtikhin, D V; Chernyshev, B V

    2011-01-01

    Electrodes were implanted into cranium above the primary visual cortex of four rabbits (Orictolagus cuniculus). At the first stage, visual evoked potentials (VEPs) were recorded in response to substitution of threshold visual stimuli (0.28 and 0.31 cd/m2). Then the sound (2000 Hz, 84 dB, duration 40 ms) was added simultaneously to every visual stimulus. Single sounds (without visual stimuli) did not produce a VEP-response. It was found that the amplitude ofVEP component N1 (85-110 ms) in response to complex stimuli (visual and sound) increased 1.6 times as compared to "simple" visual stimulation. At the second stage, paired substitutions of 8 different visual stimuli (range 0.38-20.2 cd/m2) by each other were performed. Sensory spaces of intensity were reconstructed on the basis of factor analysis. Sensory spaces of complexes were reconstructed in a similar way for simultaneous visual and sound stimulation. Comparison of vectors representing the stimuli in the spaces showed that the addition of a sound led to a 1.4-fold expansion of the space occupied by smaller intensities (0.28; 1.02; 3.05; 6.35 cd/m2). Also, the addition of the sound led to an arrangement of intensities in an ascending order. At the same time, the sound 1.33-times narrowed the space of larger intensities (8.48; 13.7; 16.8; 20.2 cd/m2). It is suggested that the addition of a sound improves a distinction of smaller intensities and impairs a dis- tinction of larger intensities. Sensory spaces revealed by complex stimuli were two-dimensional. This fact can be a consequence of integration of sound and light in a unified complex at simultaneous stimulation.

  2. Multiple light scattering in metallic ejecta produced under intense shockwave compression.

    PubMed

    Franzkowiak, J-E; Mercier, P; Prudhomme, G; Berthe, L

    2018-04-10

    A roughened metallic plate, subjected to intense shock wave compression, gives rise to an expanding ejecta particle cloud. Photonic Doppler velocimetry (PDV), a fiber-based heterodyne velocimeter, is often used to track ejecta velocities in dynamic compression experiments and on nanosecond time scales. Shortly after shock breakout at the metal-vacuum interface, a particular feature observed in many experiments in the velocity spectrograms is what appear to be slow-moving ejecta, below the free-surface velocity. Using Doppler Monte Carlo simulations incorporating the transport of polarization in the ejecta, we show that this feature is likely to be explained by the multiple scattering of light, rather than by possible collisions among particles, slowing down the ejecta. As the cloud expands in a vacuum, the contribution of multiple scattering decreases due to the limited field of view of the pigtailed collimator used to probe the ejecta, showing that the whole geometry of the system must be taken into account in the calculations to interpret and predict PDV measurements.

  3. Recent Developments of Versatile Photoinitiating Systems for Cationic Ring Opening Polymerization Operating at Any Wavelengths and under Low Light Intensity Sources.

    PubMed

    Lalevée, Jacques; Mokbel, Haifaa; Fouassier, Jean-Pierre

    2015-04-20

    Photoinitiators (PI) or photoinitiating systems (PIS) usable in light induced cationic polymerization (CP) and free radical promoted cationic polymerization (FRPCP) reactions (more specifically for cationic ring opening polymerization (ROP)) together with the involved mechanisms are briefly reviewed. The recent developments of novel two- and three-component PISs for CP and FRPCP upon exposure to low intensity blue to red lights is emphasized in details. Examples of such reactions under various experimental conditions are provided.

  4. The need for lighting education

    NASA Astrophysics Data System (ADS)

    Julian, Warren G.

    2002-05-01

    It is amazing that in a world now dominated by light - a world that is absolutely dependent upon light - that there is almost no lighting education. In a few countries of the world there exist tertiary level lighting programs but these can be counted on the fingers of two hands. Developments in lighting technology have produced a range of design tools that can lead to improved and energy-efficient lighting. However, most of this technology is 'harder' to use than traditional technology, emphasizing the need for not only improved lighting education but for its initiation. This paper discusses the need for education and uses the example of the University of Sydney program as a possible basis for others to use. It also examines how it is being delivered in Singapore.

  5. Orbital Solutions and Absolute Elements of the Eclipsing Binary YY Ceti

    NASA Astrophysics Data System (ADS)

    Williamon, Richard M.; Sowell, James R.

    2012-05-01

    YY Cet is a 10.5 mag semidetached variable with a 19 hr orbital period. The Wilson-Devinney program is used to simultaneously solve two new sets of UBV light curves together with preexisting photometry and single-line radial velocity measurements . The system has the lower-mass component completely filling its Roche lobe. The resulting masses are M1 = 1.78 ± 0.19 M⊙ and M2 = 0.92 ± 0.10 M⊙, and the radii are R1 = 2.08 ± 0.08 R⊙ and R2 = 1.62 ± 0.06 R⊙. Its computed distance is 534 ± 28 pc. Light- and velocity-curve parameters, orbital elements, and absolute dimensions are presented. A study of published TOM observations indicates that the period changed around 1999.

  6. Disposable condenser humidifiers in intensive care.

    PubMed

    Oh, T E; Thompson, W R; Hayward, D R

    1981-11-01

    Two disposable condenser humidifiers were evaluated in nine ventilated intensive care patients. The Portex "Humid Vent" delivered end-inspired absolute humidities of 22--26.3 g/m3 at end-inspired temperatures of 27--28.3 degrees C. Corresponding humidities and temperatures with the Servo "Humidifier 150" were higher and were constant, at 27.7--29 g/m3 and 29.3--29.7 degrees C respectively. These disposable devices can be used for humidification in intensive care, but only for patients breathing room air, or on a short term basis.

  7. Individuals underestimate moderate and vigorous intensity physical activity.

    PubMed

    Canning, Karissa L; Brown, Ruth E; Jamnik, Veronica K; Salmon, Art; Ardern, Chris I; Kuk, Jennifer L

    2014-01-01

    It is unclear whether the common physical activity (PA) intensity descriptors used in PA guidelines worldwide align with the associated percent heart rate maximum method used for prescribing relative PA intensities consistently between sexes, ethnicities, age categories and across body mass index (BMI) classifications. The objectives of this study were to determine whether individuals properly select light, moderate and vigorous intensity PA using the intensity descriptions in PA guidelines and determine if there are differences in estimation across sex, ethnicity, age and BMI classifications. 129 adults were instructed to walk/jog at a "light," "moderate" and "vigorous effort" in a randomized order. The PA intensities were categorized as being below, at or above the following %HRmax ranges of: 50-63% for light, 64-76% for moderate and 77-93% for vigorous effort. On average, people correctly estimated light effort as 51.5±8.3%HRmax but underestimated moderate effort as 58.7±10.7%HRmax and vigorous effort as 69.9±11.9%HRmax. Participants walked at a light intensity (57.4±10.5%HRmax) when asked to walk at a pace that provided health benefits, wherein 52% of participants walked at a light effort pace, 19% walked at a moderate effort and 5% walked at a vigorous effort pace. These results did not differ by sex, ethnicity or BMI class. However, younger adults underestimated moderate and vigorous intensity more so than middle-aged adults (P<0.05). When the common PA guideline descriptors were aligned with the associated %HRmax ranges, the majority of participants underestimated the intensity of PA that is needed to obtain health benefits. Thus, new subjective descriptions for moderate and vigorous intensity may be warranted to aid individuals in correctly interpreting PA intensities.

  8. Laser-induced photo emission detection: data acquisition based on light intensity counting

    NASA Astrophysics Data System (ADS)

    Yulianto, N.; Yudasari, N.; Putri, K. Y.

    2017-04-01

    Laser Induced Breakdown Detection (LIBD) is one of the quantification techniques for colloids. There are two ways of detection in LIBD: optical detection and acoustic detection. LIBD is based on the detection of plasma emission due to the interaction between particle and laser beam. In this research, the changing of light intensity during plasma formations was detected by a photodiode sensor. A photo emission data acquisition system was built to collect and transform them into digital counts. The real-time system used data acquisition device National Instrument DAQ 6009 and LABVIEW software. The system has been tested on distilled water and tap water samples. The result showed 99.8% accuracy by using counting technique in comparison to the acoustic detection with sample rate of 10 Hz, thus the acquisition system can be applied as an alternative method to the existing LIBD acquisition system.

  9. Absolute-length determination of a long-baseline Fabry-Perot cavity by means of resonating modulation sidebands.

    PubMed

    Araya, A; Telada, S; Tochikubo, K; Taniguchi, S; Takahashi, R; Kawabe, K; Tatsumi, D; Yamazaki, T; Kawamura, S; Miyoki, S; Moriwaki, S; Musha, M; Nagano, S; Fujimoto, M K; Horikoshi, K; Mio, N; Naito, Y; Takamori, A; Yamamoto, K

    1999-05-01

    A new method has been demonstrated for absolute-length measurements of a long-baseline Fabry-Perot cavity by use of phase-modulated light. This method is based on determination of a free spectral range (FSR) of the cavity from the frequency difference between a carrier and phase-modulation sidebands, both of which resonate in the cavity. Sensitive response of the Fabry-Perot cavity near resonant frequencies ensures accurate determination of the FSR and thus of the absolute length of the cavity. This method was applied to a 300-m Fabry-Perot cavity of the TAMA gravitational wave detector that is being developed at the National Astronomical Observatory, Tokyo. With a modulation frequency of approximately 12 MHz, we successfully determined the absolute cavity length with resolution of 1 microm (3 x 10(-9) in strain) and observed local ground strain variations of 6 x 10(-8).

  10. Signal intensity influences on the atomic Faraday filter.

    PubMed

    Luo, Bin; Yin, Longfei; Xiong, Junyu; Chen, Jingbiao; Guo, Hong

    2018-06-01

    Previous studies of the Faraday anomalous dispersion optical filter (FADOF) mainly focus on the weak signal light filtering, without regard for the influences of the signal light intensity on the filter itself. However, in some applications the signal light is strong enough to change the filter's performance. In this work, the influences of the signal light intensity on the transmittance spectrum is experimentally investigated in a 780 nm Rb85 FADOF in both the line-center and wings operation modes. The results show that the transmittance spectrum varies significantly with the signal light intensity. As the signal light increases, some existing transmittance peaks decline, some new transmittance peaks appear, and the maximum transmittance peak frequency may change. The spectrum in strong signal lights can be quite different from those calculated by programs in the condition of weak signal lights. These results are important for applications of the FADOF in the condition of strong signal lights.

  11. Light intensity and production parameters of phytocenoses cultivated on soil-like substrate under controlled [correction of controled] environment conditions.

    PubMed

    Tikhomirov, A A; Ushakova, S A; Gribovskaya, I A; Tirranen, L S; Manukovsky, N S; Zolotukhin, I G; Karnachuk, R A; Gros, J B; Lasseur, Ch

    2003-01-01

    To increase the degree of closure of biological life support systems of a new generation, we used vermicomposting to involve inedible phytomass in the intra-system mass exchange. The resulting product was a soil-like substrate, which was quite suitable for growing plants (Manukovsky et al. 1996, 1997). However, the soil like substrate can be regarded as a candidate for inclusion in a system only after a comprehensive examination of its physical, chemical, and other characteristics. An important criterion is the ability of the soil-like substrate to supply the necessary mineral elements to the photosynthesizing component under the chosen cultivation conditions. Thus, the purpose of this work was to study the feasibility of enhancing the production activity of wheat and radish crops by varying the intensity of photosynthetically active radiation, without decreasing the harvest index. The increase of light intensity from 920 to 1150 micromoles m-2 s-1 decreased the intensity of apparent photosynthesis of the wheat crops and slightly increased the apparent photosynthesis of the radish crops The maximum total and grain productivity (kg/m2) of the wheat crops was attained at the irradiance of 920 micromoles m-2 s-1. Light intensity of 1150 micromoles m-2 s-1 decreased the productivity of wheat plants and had no significant effect on the productivity of the radish crops (kg/m2) as compared to 920 micromoles m-2 s-1. The qualitative and quantitative composition of microflora of the watering solution and substrate was determined by the condition of plants, developmental phase and light intensity. By the end of wheat growth under 1150 micromoles m-2 s-1 the numbers of bacteria of the coliform family and phytopathogenic bacteria in the watering solution and substrate were an order of magnitude larger than under other illumination conditions. The obtained data suggest that the cultivation of plants in a life support system on soil-like substrate from composts has a number of

  12. Infrared line intensities of chlorine monoxide

    NASA Technical Reports Server (NTRS)

    Kostiuk, T.; Faris, J. L.; Mumma, M. J.; Deming, D.; Hillman, J. J.

    1986-01-01

    Absolute infrared line intensities of several ClO lines in the rotational-vibrational (1-0) band were measured using infrared heterodyne spectroscopy near 12 microns. A measurement technique using combined ultraviolet absorption and infrared line measurements near 9.5 microns and 12 microns permitted an accurate determination of the column densities of O3 and ClO in the absorption cell and thus improved ClO line intensities. Results indicate ClO line and band intensities approximately 2.4 times lower than previous experimental results. Effects of possible failure of local thermodynamic equilibrium conditions in the absorption cell and the implication of the results for stratospheric ClO measurements in the infrared are discussed.

  13. Redox-Dependent Modulation of Anthocyanin Biosynthesis by the TCP Transcription Factor TCP15 during Exposure to High Light Intensity Conditions in Arabidopsis1[OPEN

    PubMed Central

    Viola, Ivana L.; Gonzalez, Daniel H.

    2016-01-01

    TCP proteins integrate a family of transcription factors involved in the regulation of developmental processes and hormone responses. It has been shown that most members of class I, one of the two classes in which the TCP family is divided, contain a conserved Cys that leads to inhibition of DNA binding when oxidized. In this work, we describe that the class-I TCP protein TCP15 inhibits anthocyanin accumulation during exposure of plants to high light intensity by modulating the expression of transcription factors involved in the induction of anthocyanin biosynthesis genes, as suggested by the study of plants that express TCP15 from the 35SCaMV promoter and mutants in TCP15 and the related gene TCP14. In addition, the effect of TCP15 on anthocyanin accumulation is lost after prolonged incubation under high light intensity conditions. We provide evidence that this is due to inactivation of TCP15 by oxidation of Cys-20 of the TCP domain. Thus, redox modulation of TCP15 activity in vivo by high light intensity may serve to adjust anthocyanin accumulation to the duration of exposure to high irradiation conditions. PMID:26574599

  14. Light history modulates antioxidant and photosynthetic responses of biofilms to both natural (light) and chemical (herbicides) stressors.

    PubMed

    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.

  15. NOTE: Determination of eye safety filter protection factors associated with retinal thermal hazard and blue light photochemical hazard for intense pulsed light sources

    NASA Astrophysics Data System (ADS)

    McG Clarkson, D.

    2006-02-01

    An assessment is provided of protection factors afforded for retinal thermal hazard and blue light photochemical hazard for a range of filters used with intense pulsed light sources (IPLs). A characteristic IPL spectrum based on black body radiation at 5000 K with a low cut filter at 515 nm was identified as suitable for such estimations. Specific filters assessed included types with idealized transmission properties and also a range of types whose transmission characteristics were measured by means of a Bentham DMc150 spectroradiometer. Predicted behaviour based on these spectra is outlined which describes both the effectiveness of protection and the level of luminous transmittance afforded. The analysis showed it was possible to describe a figure of merit for a particular filter material relating the degree of protection provided and corresponding value of luminous transmittance. This consideration is important for providing users of IPL equipment with safety eyewear with adequate level of visual transmittance.

  16. Absolute and geometric parameters of contact binary V1918 Cyg

    NASA Astrophysics Data System (ADS)

    Gürol, B.

    2016-08-01

    We present the results of our investigation on the geometrical and physical parameters of the W UMa type binary system V1918 Cyg from analyzed CCD (BVR) light curves and radial velocity data. We used the photometric data published by Yang et al. (2013) and spectroscopic data obtained in 2012 at TUBITAK National Observatory (TUG). The light and radial velocity observations were analyzed simultaneously by using the Wilson-Devinney (2015 revision) code to obtain absolute and geometrical parameters of the system. It is confirmed that the system is an A-type W UMa as indicated by Yang et al. (2013). Combining our spectroscopic data with the photometric solution we derived masses and radii of the eclipsing system as M1 = 1.302M⊙ , M2 = 0.362M⊙ , R1 = 1.362R⊙ and R2 = 0.762R⊙ . Finally, we discuss the evolutionary status of the system.

  17. Effects of Light Quality and Intensity on Diurnal Patterns and Rates of Photo-Assimilate Translocation and Transpiration in Tomato Leaves

    PubMed Central

    Lanoue, Jason; Leonardos, Evangelos D.; Grodzinski, Bernard

    2018-01-01

    Translocation of assimilates is a fundamental process involving carbon and water balance affecting source/sink relationships. Diurnal patterns of CO2 exchange, translocation (carbon export), and transpiration of an intact tomato source leaf were determined during 14CO2 steady-state labeling under different wavelengths at three pre-set photosynthetic rates. Daily patterns showed that photosynthesis and export were supported by all wavelengths of light tested including orange and green. Export in the light, under all wavelengths was always higher than that at night. Export in the light varied from 65–83% of the total daily carbon fixed, depending on light intensity. Photosynthesis and export were highly correlated under all wavelengths (r = 0.90–0.96). Export as a percentage of photosynthesis (relative export) decreased as photosynthesis increased by increasing light intensity under all wavelengths. These data indicate an upper limit for export under all spectral conditions. Interestingly, only at the medium photosynthetic rate, relative export under the blue and the orange light-emitting diodes (LEDs) were higher than under white and red-white LEDs. Stomatal conductance, transpiration rates, and water-use-efficiency showed similar daily patterns under all wavelengths. Illuminating tomato leaves with different spectral quality resulted in similar carbon export rates, but stomatal conductance and transpiration rates varied due to wavelength specific control of stomatal function. Thus, we caution that the link between transpiration and C-export may be more complex than previously thought. In summary, these data indicate that orange and green LEDs, not simply the traditionally used red and blue LEDs, should be considered and tested when designing lighting systems for optimizing source leaf strength during plant production in controlled environment systems. In addition, knowledge related to the interplay between water and C-movement within a plant and how they are

  18. Individual-based measurements of light intensity provide new insights into the effects of artificial light at night on daily rhythms of urban-dwelling songbirds.

    PubMed

    Dominoni, Davide M; Carmona-Wagner, Esther O; Hofmann, Michaela; Kranstauber, Bart; Partecke, Jesko

    2014-05-01

    The growing interest in the effects of light pollution on daily and seasonal cycles of animals has led to a boost of research in recent years. In birds, it has been hypothesized that artificial light at night can affect daily aspects of behaviour, but one caveat is the lack of knowledge about the light intensity that wild animals, such as birds, are exposed to during the night. Organisms have naturally evolved daily rhythms to adapt to the 24-h cycle of day and night, thus, it is important to investigate the potential shifts in daily cycles due to global anthropogenic processes such as urbanization. We captured adult male European blackbirds (Turdus merula) in one rural forest and two urban sites differing in the degree of anthropogenic disturbance. We tagged these birds with light loggers and simultaneously recorded changes in activity status (active/non-active) through an automated telemetry system. We first analysed the relationship between light at night, weather conditions and date with daily activity onset and end. We then compared activity, light at night exposure and noise levels between weekdays and weekends. Onset of daily activity was significantly advanced in both urban sites compared to the rural population, while end of daily activity did not vary either among sites. Birds exposed to higher amounts of light in the late night showed earlier onset of activity in the morning, but light at night did not influence end of daily activity. Light exposure at night and onset/end of daily activity timing was not different between weekdays and weekends, but all noise variables were. A strong seasonal effect was detected in both urban and rural populations, such as birds tended to be active earlier in the morning and later in the evening (relative to civil twilight) in the early breeding season than at later stages. Our results point at artificial light at night as a major driver of change in timing of daily activity. Future research should focus on the costs and

  19. Cross section of resonant Raman scattering of light by polyenes

    NASA Astrophysics Data System (ADS)

    Verdyugin, V. V.; Burshteyn, K. Ya.; Shorygin, P. P.

    1987-03-01

    An experimental study is presented of the resonant Raman spectra of beta carotene. Absolute differential cross sections are obtained for the most intensive Raman spectral lines with excitation at the absorption maximum. A theoretical analysis is presented of the variation in absolute differential cross section as a function of a number of conjunct double bonds in the polyenes.

  20. Rapid thermal annealing of CH 3 NH 3 PbI 3 perovskite thin films by intense pulsed light with aid of diiodomethane additive

    DOE PAGES

    Ankireddy, Krishnamraju; Ghahremani, Amir H.; Martin, Blake; ...

    2018-01-01

    Perovskite thin films are thermally annealed using a rapid intense pulsed light technique enabled by an alkyl halide that collectively improves device performance when processed in ambient conditions.

  1. Linear transformation of the encoding mechanism for light intensity underlies the paradoxical enhancement of cortical visual responses by sevoflurane.

    PubMed

    Arena, Alessandro; Lamanna, Jacopo; Gemma, Marco; Ripamonti, Maddalena; Ravasio, Giuliano; Zimarino, Vincenzo; De Vitis, Assunta; Beretta, Luigi; Malgaroli, Antonio

    2017-01-01

    The mechanisms of action of anaesthetics on the living brain are still poorly understood. In this respect, the analysis of the differential effects of anaesthetics on spontaneous and sensory-evoked cortical activity might provide important and novel cues. Here we show that the anaesthetic sevoflurane strongly silences the brain but potentiates in a dose- and frequency-dependent manner the cortical visual response. Such enhancement arises from a linear scaling by sevoflurane of the power-law relation between light intensity and the cortical response. The fingerprint of sevoflurane action suggests that circuit silencing can boost linearly synaptic responsiveness presumably by scaling the number of responding units and/or their correlation following a sensory stimulation. General anaesthetics, which are expected to silence brain activity, often spare sensory responses. To evaluate differential effects of anaesthetics on spontaneous and sensory-evoked cortical activity, we characterized their modulation by sevoflurane and propofol. Power spectra and the bust-suppression ratio from EEG data were used to evaluate anaesthesia depth. ON and OFF cortical responses were elicited by light pulses of variable intensity, duration and frequency, during light and deep states of anaesthesia. Both anaesthetics reduced spontaneous cortical activity but sevoflurane greatly enhanced while propofol diminished the ON visual response. Interestingly, the large potentiation of the ON visual response by sevoflurane was found to represent a linear scaling of the encoding mechanism for light intensity. To the contrary, the OFF cortical visual response was depressed by both anaesthetics. The selective depression of the OFF component by sevoflurane could be converted into a robust potentiation by the pharmacological blockade of the ON pathway, suggesting that the temporal order of ON and OFF responses leads to a depression of the latter. This hypothesis agrees with the finding that the

  2. Forecasting Error Calculation with Mean Absolute Deviation and Mean Absolute Percentage Error

    NASA Astrophysics Data System (ADS)

    Khair, Ummul; Fahmi, Hasanul; Hakim, Sarudin Al; Rahim, Robbi

    2017-12-01

    Prediction using a forecasting method is one of the most important things for an organization, the selection of appropriate forecasting methods is also important but the percentage error of a method is more important in order for decision makers to adopt the right culture, the use of the Mean Absolute Deviation and Mean Absolute Percentage Error to calculate the percentage of mistakes in the least square method resulted in a percentage of 9.77% and it was decided that the least square method be worked for time series and trend data.

  3. Three dimensional particle-in-cell simulations of electron beams created via reflection of intense laser light from a water target

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ngirmang, Gregory K., E-mail: ngirmang.1@osu.edu; Orban, Chris; Feister, Scott

    We present 3D Particle-in-Cell (PIC) modeling of an ultra-intense laser experiment by the Extreme Light group at the Air Force Research Laboratory using the Large Scale Plasma (LSP) PIC code. This is the first time PIC simulations have been performed in 3D for this experiment which involves an ultra-intense, short-pulse (30 fs) laser interacting with a water jet target at normal incidence. The laser-energy-to-ejected-electron-energy conversion efficiency observed in 2D(3v) simulations were comparable to the conversion efficiencies seen in the 3D simulations, but the angular distribution of ejected electrons in the 2D(3v) simulations displayed interesting differences with the 3D simulations' angular distribution;more » the observed differences between the 2D(3v) and 3D simulations were more noticeable for the simulations with higher intensity laser pulses. An analytic plane-wave model is discussed which provides some explanation for the angular distribution and energies of ejected electrons in the 2D(3v) simulations. We also performed a 3D simulation with circularly polarized light and found a significantly higher conversion efficiency and peak electron energy, which is promising for future experiments.« less

  4. Relativistic Ionization with Intense Linearly Polarized Light

    NASA Astrophysics Data System (ADS)

    Crawford, Douglas Plummer

    The Strong Field Approximation (SFA) method is used to derive relativistic ionization rate expressions for ground state hydrogen-like atoms in the presence of an intense electromagnetic field. The emitted particle, which is initially bound to a hydrogen nucleus, is either an electron described by the Dirac equation, with spin effects fully included, or a spinless "electron" described by the Klein-Gordon equation. The derivations and subsequent calculations for both particles are made assuming a linearly polarized electromagnetic field which is monochromatic and which exhibits neither diffraction nor temporal dependence. From each of the relativistic ionization rate expressions, the corresponding expression in the nonrelativistic limit is derived. The resultant expressions are found to be equivalent to those derived using the SFA with the nonrelativistic formalism. This comparison provides the first check of the validity for the core results of this dissertation. Intensity-dependent ionization rates are then calculated for two ultraviolet frequencies using a numerical implementation of the derived expressions. Calculations of ionization rates and related phenomena demonstrate that there are negligible differences between relativistic and nonrelativistic predictions for low intensities. In addition, the differences in behavior between linearly and circularly polarized ionizing fields and between particles with and without spin are explored. The spin comparisons provide additional confidence in the derivations by showing negligible differences between ionization rates for Dirac and Klein -Gordon particles in strong linearly-polarized fields. Also of interest are the differential transition rates which exhibit dynamic profiles as the intensity is increased. This behavior is interpreted as an indication of more atomic influence for linearly polarized electromagnetic (em) fields than for circularly polarized em fields.

  5. Study on improving the turbidity measurement of the absolute coagulation rate constant.

    PubMed

    Sun, Zhiwei; Liu, Jie; Xu, Shenghua

    2006-05-23

    The existing theories dealing with the evaluation of the absolute coagulation rate constant by turbidity measurement were experimentally tested for different particle-sized (radius = a) suspensions at incident wavelengths (lambda) ranging from near-infrared to ultraviolet light. When the size parameter alpha = 2pi a/lambda > 3, the rate constant data from previous theories for fixed-sized particles show significant inconsistencies at different light wavelengths. We attribute this problem to the imperfection of these theories in describing the light scattering from doublets through their evaluation of the extinction cross section. The evaluations of the rate constants by all previous theories become untenable as the size parameter increases and therefore hampers the applicable range of the turbidity measurement. By using the T-matrix method, we present a robust solution for evaluating the extinction cross section of doublets formed in the aggregation. Our experiments show that this new approach is effective in extending the applicability range of the turbidity methodology and increasing measurement accuracy.

  6. Numerical simulations of the hard X-ray pulse intensity distribution at the Linac Coherent Light Source

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pardini, Tom; Aquila, Andrew; Boutet, Sebastien

    Numerical simulations of the current and future pulse intensity distributions at selected locations along the Far Experimental Hall, the hard X-ray section of the Linac Coherent Light Source (LCLS), are provided. Estimates are given for the pulse fluence, energy and size in and out of focus, taking into account effects due to the experimentally measured divergence of the X-ray beam, and measured figure errors of all X-ray optics in the beam path. Out-of-focus results are validated by comparison with experimental data. Previous work is expanded on, providing quantitatively correct predictions of the pulse intensity distribution. Numerical estimates in focus aremore » particularly important given that the latter cannot be measured with direct imaging techniques due to detector damage. Finally, novel numerical estimates of improvements to the pulse intensity distribution expected as part of the on-going upgrade of the LCLS X-ray transport system are provided. As a result, we suggest how the new generation of X-ray optics to be installed would outperform the old one, satisfying the tight requirements imposed by X-ray free-electron laser facilities.« less

  7. Numerical simulations of the hard X-ray pulse intensity distribution at the Linac Coherent Light Source

    DOE PAGES

    Pardini, Tom; Aquila, Andrew; Boutet, Sebastien; ...

    2017-06-15

    Numerical simulations of the current and future pulse intensity distributions at selected locations along the Far Experimental Hall, the hard X-ray section of the Linac Coherent Light Source (LCLS), are provided. Estimates are given for the pulse fluence, energy and size in and out of focus, taking into account effects due to the experimentally measured divergence of the X-ray beam, and measured figure errors of all X-ray optics in the beam path. Out-of-focus results are validated by comparison with experimental data. Previous work is expanded on, providing quantitatively correct predictions of the pulse intensity distribution. Numerical estimates in focus aremore » particularly important given that the latter cannot be measured with direct imaging techniques due to detector damage. Finally, novel numerical estimates of improvements to the pulse intensity distribution expected as part of the on-going upgrade of the LCLS X-ray transport system are provided. As a result, we suggest how the new generation of X-ray optics to be installed would outperform the old one, satisfying the tight requirements imposed by X-ray free-electron laser facilities.« less

  8. Clinical studies of the High-Intensity Narrow-Spectrum light Environmental Decontamination System (HINS-light EDS), for continuous disinfection in the burn unit inpatient and outpatient settings.

    PubMed

    Bache, Sarah E; Maclean, Michelle; MacGregor, Scott J; Anderson, John G; Gettinby, George; Coia, John E; Taggart, Ian

    2012-02-01

    Infections are the leading cause of morbidity and mortality in burn patients and prevention of contamination from exogenous sources including the hospital environment is becoming increasingly emphasised. The High-Intensity Narrow-Spectrum light Environmental Decontamination System (HINS-light EDS) is bactericidal yet safe for humans, allowing continuous disinfection of the environment surrounding burn patients. Environmental samples were collected from inpatient isolation rooms and the outpatient clinic in the burn unit, and comparisons were then made between the bacterial contamination levels observed with and without use of the HINS-light EDS. Over 1000 samples were taken. Inpatient studies, with sampling carried out at 0800 h, demonstrated a significant reduction in the average number of bacterial colonies following HINS-light EDS use of between 27% and 75%, (p<0.05). There was more variation when samples were taken at times of increased activity in the room. Outpatient studies during clinics demonstrated a 61% efficacy in the reduction of bacterial contamination on surfaces throughout the room during the course of a clinic (p=0.02). The results demonstrate that use of the HINS-light EDS allows efficacious bacterial reductions over and above that achieved by standard cleaning and infection control measures in both inpatient and outpatient settings in the burn unit. Copyright © 2011 Elsevier Ltd and ISBI. All rights reserved.

  9. Bumblebees Perform Well-Controlled Landings in Dim Light.

    PubMed

    Reber, Therese; Dacke, Marie; Warrant, Eric; Baird, Emily

    2016-01-01

    To make a smooth touchdown when landing, an insect must be able to reliably control its approach speed as well as its body and leg position-behaviors that are thought to be regulated primarily by visual information. Bumblebees forage and land under a broad range of light intensities and while their behavior during the final moments of landing has been described in detail in bright light, little is known about how this is affected by decreasing light intensity. Here, we investigate this by characterizing the performance of bumblebees, B. terrestris, landing on a flat platform at two different orientations (horizontal and vertical) and at four different light intensities (ranging from 600 lx down to 19 lx). As light intensity decreased, the bees modified their body position and the distance at which they extended their legs, suggesting that the control of landing in these insects is visually mediated. Nevertheless, the effect of light intensity was small and the landings were still well controlled, even in the dimmest light. We suggest that the changes in landing behavior that occurred in dim light might represent adaptations that allow the bees to perform smooth landings across the broad range of light intensities at which they are active.

  10. GAS EXCHANGE OF ALGAE. I. EFFECTS OF TIME, LIGHT INTENSITY, AND SPECTRAL-ENERGY DISTRIBUTION ON THE PHOTOSYNTHETIC QUOTIENT OF CHLORELLA PYRENOIDOSA.

    PubMed

    AMMANN, E C; LYNCH, V H

    1965-07-01

    Continuously growing cultures of Chlorella pyrenoidosa Starr 252, operating at constant density and under constant environmental conditions, produced uniform photosynthetic quotient (PQ = CO(2)/O(2)) and O(2) values during 6 months of observations. The PQ for the entire study was 0.90 +/- 0.024. The PQ remained constant over a threefold light-intensity change and a threefold change in O(2) production (0.90 +/- 0.019). At low light intensities, when the rate of respiration approached the rate of photosynthesis, the PQ became extremely variable. Six lamps of widely different spectral-energy distribution produced no significant change in the PQ (0.90 +/- 0.025). Oxygen production was directly related to the number of quanta available, irrespective of spectral-energy distribution. Such dependability in producing uniform PQ and O(2) values warrants a consideration of algae to maintain a constant gas environment for submarine or spaceship use.

  11. 20 CFR 404.1205 - Absolute coverage groups.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Absolute coverage groups. 404.1205 Section... INSURANCE (1950- ) Coverage of Employees of State and Local Governments What Groups of Employees May Be Covered § 404.1205 Absolute coverage groups. (a) General. An absolute coverage group is a permanent...

  12. 20 CFR 404.1205 - Absolute coverage groups.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Absolute coverage groups. 404.1205 Section... INSURANCE (1950- ) Coverage of Employees of State and Local Governments What Groups of Employees May Be Covered § 404.1205 Absolute coverage groups. (a) General. An absolute coverage group is a permanent...

  13. 20 CFR 404.1205 - Absolute coverage groups.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Absolute coverage groups. 404.1205 Section... INSURANCE (1950- ) Coverage of Employees of State and Local Governments What Groups of Employees May Be Covered § 404.1205 Absolute coverage groups. (a) General. An absolute coverage group is a permanent...

  14. Case Histories of Intense Pulsed Light Phototherapy in Dermatology - the HPPL™ and IFL™ Technologies

    PubMed Central

    Martella, Alessandro; Raichi, Mauro

    2017-01-01

    The intense pulsed light (IPL) and laser technologies are widely used for skin rejuvenation and for treating several dermatological disorders such as skin dyschromia and acne, and for non-ablative dermal remodeling of rhytides and hypertrophic scars. Technological evolution is rapid. The High Power Pulsed Light™ [HPPL™] and Incoherent Fast Light™ technologies [IFL™, Novavision Group S.p.A., 20826 Misinto (MB), Italy] are recent innovations in the field of IPL technologies; IFL™ is a further evolution of the already advanced HPPL™ system. The paper presents a selection of case histories of dermatological lesions treated with the HPPL™ and IFL™ technologies. All study materials were appropriately peer-reviewed for ethical problems. PMID:28652908

  15. An intervention to reduce sitting and increase light-intensity physical activity at work: Design and rationale of the 'Stand & Move at Work' group randomized trial.

    PubMed

    Buman, Matthew P; Mullane, Sarah L; Toledo, Meynard J; Rydell, Sarah A; Gaesser, Glenn A; Crespo, Noe C; Hannan, Peter; Feltes, Linda; Vuong, Brenna; Pereira, Mark A

    2017-02-01

    American workers spend 70-80% of their time at work being sedentary. Traditional approaches to increase moderate-vigorous physical activity (MVPA) may be perceived to be harmful to productivity. Approaches that target reductions in sedentary behavior and/or increases in standing or light-intensity physical activity [LPA] may not interfere with productivity and may be more feasible to achieve through small changes accumulated throughout the workday METHODS/DESIGN: This group randomized trial (i.e., cluster randomized trial) will test the relative efficacy of two sedentary behavior focused interventions in 24 worksites across two states (N=720 workers). The MOVE+ intervention is a multilevel individual, social, environmental, and organizational intervention targeting increases in light-intensity physical activity in the workplace. The STAND+ intervention is the MOVE+ intervention with the addition of the installation and use of sit-stand workstations to reduce sedentary behavior and enhance light-intensity physical activity opportunities. Our primary outcome will be objectively-measured changes in sedentary behavior and light-intensity physical activity over 12months, with additional process measures at 3months and longer-term sustainability outcomes at 24months. Our secondary outcomes will be a clustered cardiometabolic risk score (comprised of fasting glucose, insulin, triglycerides, HDL-cholesterol, and blood pressure), workplace productivity, and job satisfaction DISCUSSION: This study will determine the efficacy of a multi-level workplace intervention (including the use of a sit-stand workstation) to reduce sedentary behavior and increase LPA and concomitant impact on cardiometabolic health, workplace productivity, and satisfaction. ClinicalTrials.gov Identifier: NCT02566317 (date of registration: 10/1/2015). Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Rapid rotators revisited: absolute dimensions of KOI-13

    NASA Astrophysics Data System (ADS)

    Howarth, Ian D.; Morello, Giuseppe

    2017-09-01

    We analyse Kepler light-curves of the exoplanet Kepler Object of Interest no. 13b (KOI-13b) transiting its moderately rapidly rotating (gravity-darkened) parent star. A physical model, with minimal ad hoc free parameters, reproduces the time-averaged light-curve at the ˜10 parts per million level. We demonstrate that this Roche-model solution allows the absolute dimensions of the system to be determined from the star's projected equatorial rotation speed, ve sin I*, without any additional assumptions; we find a planetary radius RP = (1.33 ± 0.05) R♃, stellar polar radius Rp★ = (1.55 ± 0.06) R⊙, combined mass M* + MP( ≃ M*) = (1.47 ± 0.17) M⊙ and distance d ≃ (370 ± 25) pc, where the errors are dominated by uncertainties in relative flux contribution of the visual-binary companion KOI-13B. The implied stellar rotation period is within ˜5 per cent of the non-orbital, 25.43-hr signal found in the Kepler photometry. We show that the model accurately reproduces independent tomographic observations, and yields an offset between orbital and stellar-rotation angular-momentum vectors of 60.25° ± 0.05°.

  17. Synthesis and photoluminescence properties of a cyan-emitting phosphor Ca3(PO4)2:Eu2+ for white light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Zhou, Wenli; Han, Jin; Zhang, Xuejie; Qiu, Zhongxian; Xie, Qingji; Liang, Hongbin; Lian, Shixun; Wang, Jing

    2015-01-01

    In this paper, a cyan-emitting phosphor Ca3(PO4)2:Eu2+ (TCP:Eu2+) was synthesized and evaluated as a candidate for white light emitting diodes (WLEDs). This phosphor shows strong and broad absorption in 250-450 nm region, but the emission spectrum is prominent at around 480 nm. The emission intensity of the TCP:Eu2+ was found to be 60% and 82% of that of the commercial BaMgAl10O17:Eu2+ (BAM) under excitation at 340 nm and 370 nm, respectively. Upon excitation at 370 nm, the absolute internal and external quantum efficiencies of the Ca3(PO4)2:1.5%Eu2+ are 60% and 42%, respectively. Moreover, a white LED lamp was fabricated by coating TCP:Eu2+ with a blue-emitting BAM and a red-emitting CaAlSiN3:Eu2+ on a near-ultraviolet (375 nm) LED chip, driven by a 350 mA forward bias current, and it produces an intense white light with a color rendering index of 75.

  18. An intervention to reduce sitting and increase light-intensity physical activity at work: Design and rationale of the ‘Stand & Move at Work’ group randomized trial

    PubMed Central

    Buman, Matthew P.; Mullane, Sarah L.; Toledo, Meynard J.; Rydell, Sarah A.; Gaesser, Glenn A.; Crespo, Noe C.; Hannan, Peter; Feltes, Linda; Vuong, Brenna; Pereira, Mark A

    2016-01-01

    Background American workers spend 70–80% of their time at work being sedentary. Traditional approaches to increase moderate-vigorous physical activity (MVPA) may be perceived to be harmful to productivity. Approaches that target reductions in sedentary behavior and/or increases in standing or light-intensity physical activity [LPA] may not interfere with productivity and may be more feasible to achieve through small changes accumulated throughout the workday. Methods/Design This group randomized trial (i.e., cluster randomized trial) will test the relative efficacy of two sedentary behavior focused interventions in 24 worksites across two states (N=720 workers). The MOVE+ intervention is a multilevel individual, social, environmental, and organizational intervention targeting increases in light-intensity physical activity in the workplace. The STAND+ intervention is the MOVE+ intervention with the addition of the installation and use of sit-stand workstations to reduce sedentary behavior and enhance light-intensity physical activity opportunities. Our primary outcome will be objectively-measured changes in sedentary behavior and light-intensity physical activity over 12 months, with additional process measures at 3 months and longer-term sustainability outcomes at 24 months. Our secondary outcomes will be a clustered cardiometabolic risk score (comprised of fasting glucose, insulin, triglycerides, HDL-cholesterol, and blood pressure), workplace productivity, and job satisfaction. Discussion This study will determine the efficacy of a multilevel workplace intervention (including the use of a sit-stand workstation) to reduce sedentary behavior and increase LPA and concomitant impact on cardiometabolic health, workplace productivity, and satisfaction. PMID:27940181

  19. Implications of an Absolute Simultaneity Theory for Cosmology and Universe Acceleration

    PubMed Central

    Kipreos, Edward T.

    2014-01-01

    An alternate Lorentz transformation, Absolute Lorentz Transformation (ALT), has similar kinematics to special relativity yet maintains absolute simultaneity in the context of a preferred reference frame. In this study, it is shown that ALT is compatible with current experiments to test Lorentz invariance only if the proposed preferred reference frame is locally equivalent to the Earth-centered non-rotating inertial reference frame, with the inference that in an ALT framework, preferred reference frames are associated with centers of gravitational mass. Applying this theoretical framework to cosmological data produces a scenario of universal time contraction in the past. In this scenario, past time contraction would be associated with increased levels of blueshifted light emissions from cosmological objects when viewed from our current perspective. The observation that distant Type Ia supernovae are dimmer than predicted by linear Hubble expansion currently provides the most direct evidence for an accelerating universe. Adjusting for the effects of time contraction on a redshift–distance modulus diagram produces a linear distribution of supernovae over the full redshift spectrum that is consistent with a non-accelerating universe. PMID:25536116

  20. Implications of an absolute simultaneity theory for cosmology and universe acceleration.

    PubMed

    Kipreos, Edward T

    2014-01-01

    An alternate Lorentz transformation, Absolute Lorentz Transformation (ALT), has similar kinematics to special relativity yet maintains absolute simultaneity in the context of a preferred reference frame. In this study, it is shown that ALT is compatible with current experiments to test Lorentz invariance only if the proposed preferred reference frame is locally equivalent to the Earth-centered non-rotating inertial reference frame, with the inference that in an ALT framework, preferred reference frames are associated with centers of gravitational mass. Applying this theoretical framework to cosmological data produces a scenario of universal time contraction in the past. In this scenario, past time contraction would be associated with increased levels of blueshifted light emissions from cosmological objects when viewed from our current perspective. The observation that distant Type Ia supernovae are dimmer than predicted by linear Hubble expansion currently provides the most direct evidence for an accelerating universe. Adjusting for the effects of time contraction on a redshift-distance modulus diagram produces a linear distribution of supernovae over the full redshift spectrum that is consistent with a non-accelerating universe.