scholarly journals Statistical Modeling of Photo-Bending Actuation of Hybrid Silicones Mixed with Azobenzene Powder

Actuators ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 68 ◽  
Author(s):  
Takuya Taniguchi ◽  
Loïc Blanc ◽  
Toru Asahi ◽  
Hideko Koshima ◽  
Pierre Lambert
Keyword(s):  
Light Intensity ◽  
Statistical Modeling ◽  
Light Source ◽  
Analysis Of Variance ◽  
Time Variable ◽  
Soft Robotics ◽  
Responsive Materials ◽  
Modeling Process ◽  
Bending Behavior ◽  
Time Courses

Mechanically responsive materials are promising as next-generation actuators for soft robotics, but have scarce reports on the statistical modeling of the actuation behavior. This research reports on the development and modeling of the photomechanical bending behavior of hybrid silicones mixed with azobenzene powder. The photo-responsive hybrid silicone bends away from the light source upon light irradiation when a thin paper is attached on the hybrid silicone. The time courses of bending behaviors were fitted well with exponential models with a time variable, affording fitting constants at each experimental condition. These fitted parameters were further modeled using the analysis of variance (ANOVA). Cubic models were proposed for both the photo-bending and unbending processes, which were parameterized by the powder ratio and the light intensity. This modeling process allows such photo-responsive materials to be controlled as actuators, and will possibly be effective for engineering mechanically responsive materials.

Inter-Method Reliability of Pulse Volume Related Measures Derived Using Finger-Photoplethysmography

2018 ◽  
Vol 32 (4) ◽  
pp. 182-190 ◽  
Author(s):  
Kenta Matsumura ◽  
Koichi Shimizu ◽  
Peter Rolfe ◽  
Masanori Kakimoto ◽  
Takehiro Yamakoshi
Keyword(s):  
Light Intensity ◽  
Adverse Effects ◽  
Light Source ◽  
Direct Current ◽  
Resting State ◽  
Current Component ◽  
Psychophysiological Measures ◽  
Pulse Volume ◽  
Optical Paths ◽  
Sensor Positions

Abstract. Pulse volume (PV) and its related measures, such as modified normalized pulse volume (mNPV), direct-current component (DC), and pulse rate (PR), derived from the finger-photoplethysmogram (FPPG), are useful psychophysiological measures. Although considerable uncertainties exist in finger-photoplethysmography, little is known about the extent of the adverse effects on the measures. In this study, we therefore examined the inter-method reliability of each index across sensor positions and light intensities, which are major disturbance factors of FPPG. From the tips of the index fingers of 12 participants in a resting state, three simultaneous FPPGs having overlapping optical paths were recorded, with their light intensity being changed in three steps. The analysis revealed that the minimum values of three coefficients of Cronbach’s α for ln PV, ln mNPV, ln DC, and PR across positions were .948, .850, .922, and 1.000, respectively, and that those across intensities were .774, .985, .485, and .998, respectively. These findings suggest that ln mNPV and PR can be used for psychophysiological studies irrespective of minor differences in sensor attachment positions and light source intensity, whereas and ln DC can also be used for such studies but under the condition of light intensity being fixed.

scholarly journals Cyanobacteria use micro-optics to sense light direction

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Nils Schuergers ◽  
Tchern Lenn ◽  
Ronald Kampmann ◽  
Markus V Meissner ◽  
Tiago Esteves ◽  
...  
Keyword(s):  
Light Intensity ◽  
Light Source ◽  
Type Iv Pili ◽  
Small Cells ◽  
Unicellular Cyanobacterium ◽  
Light Sensing ◽  
High Resolution Image ◽  
Type Iv ◽  
Micro Optics ◽  
Synechocystis Sp

Bacterial phototaxis was first recognized over a century ago, but the method by which such small cells can sense the direction of illumination has remained puzzling. The unicellular cyanobacterium Synechocystis sp. PCC 6803 moves with Type IV pili and measures light intensity and color with a range of photoreceptors. Here, we show that individual Synechocystis cells do not respond to a spatiotemporal gradient in light intensity, but rather they directly and accurately sense the position of a light source. We show that directional light sensing is possible because Synechocystis cells act as spherical microlenses, allowing the cell to see a light source and move towards it. A high-resolution image of the light source is focused on the edge of the cell opposite to the source, triggering movement away from the focused spot. Spherical cyanobacteria are probably the world’s smallest and oldest example of a camera eye.

scholarly journals The Effects of Day Length and Light Intensity on Tile Growth of Barley

1969 ◽  
Vol 22 (1) ◽  
pp. 53 ◽  
Author(s):  
D Aspinall
Keyword(s):  
Light Intensity ◽  
Linear Relationship ◽  
Light Source ◽  
Blue Light ◽  
Floral Development ◽  
Red Light ◽  
Day Length

The acceleration of flowering in barley due to the inclusion of incandescent illumination in the light source has been shown to be due to the far�red content of the light. A linear relationship between floral development and intensity of far�red light in a 16�hr photoperiod has been established with the cultivar CI5611. Barley appears to be relatively unresponsive to blue light, however.

Sensitive Detection of Ambient Formaldehyde by Incoherent Broadband Cavity Enhanced Absorption Spectroscopy

2020 ◽  
Author(s):  
Jingwei Liu ◽  
Xin Li ◽  
Yiming Yang ◽  
Haichao Wang ◽  
Cailing Kuang ◽  
...  
Keyword(s):  
Light Intensity ◽  
Light Source ◽  
Absorption Spectroscopy ◽  
Fiber Bundle ◽  
Ambient Air ◽  
Optical Path ◽  
Enhanced Absorption ◽  
Cavity Enhanced Absorption Spectroscopy ◽  
Near Ultraviolet ◽  
Type Fiber

<p>Formaldehyde (HCHO) is the most abundant atmospheric carbonyl compound and plays an important role in the troposphere. However, HCHO detection via traditional incoherent broadband cavity enhanced absorption spectroscopy (IBBCEAS) is limited by short optical path lengths and weak light intensity. Thus, a new light-emitting diode (LED)-based IBBCEAS was developed herein to measure HCHO in ambient air. Two LEDs (325 and 340 nm) coupled by a Y-type fiber bundle were used as an IBBCEAS light source, which provided both high light intensity and a wide spectral fitting range. The reflectivity of the two cavity mirrors used herein was 0.99965 (1 – reflectivity = 350 ppm loss) at 350 nm, which corresponded with an effective optical path length of 2.15 km within a 0.84 m cavity. At an integration time of 30 s, the measurement precision (1σ) for HCHO was 380 parts per trillion volume (pptv) and the corresponding uncertainty was 8.3%. The instrument was successfully deployed for the first time in a field campaign and delivered results that correlated well with those of a commercial wet-chemical instrument based on Hantzsch fluorimetry (R<sup>2</sup> = 0.769). The combined light source based on Y-type fiber bundle overcomes the difficulty of measuring ambient HCHO via IBBCEAS in near-ultraviolet range, which may extend IBBCEAS technology to measure other atmospheric trace gases with high precision.</p>

Stimuli-responsive cylindrical hydrogels mimic intestinal peristalsis to propel a solid object

Soft Matter ◽  
2016 ◽  
Vol 12 (15) ◽  
pp. 3582-3588 ◽  
Author(s):  
V. Nistor ◽  
J. Cannell ◽  
J. Gregory ◽  
L. Yeghiazarian
Keyword(s):  
Soft Robotics ◽  
Solid Object ◽  
Stimuli Responsive ◽  
Responsive Materials ◽  
Load Transport ◽  
Intestinal Peristalsis

The emerging field of soft robotics relies on soft, stimuli-responsive materials to enable load transport, manipulation, and mobility in complex unconstrained environments.

scholarly journals Multiplicação de bastão-do-imperador em resposta a concentrações de BAP e número de subcultivos

2016 ◽  
Vol 22 (1) ◽  
pp. 88
Author(s):  
Eder De Oliveira Santos ◽  
Antonio Anderson De Jesus Rodrigues ◽  
Esdras Rocha da Silva ◽  
Ana Cristina Portugal Pinto de Carvalho
Keyword(s):  
Experimental Design ◽  
Light Intensity ◽  
Analysis Of Variance ◽  
Culture Medium ◽  
Multiplication Rate ◽  
Commercial Cultivation ◽  
Growth Room ◽  
Tropical Flowers ◽  
Etlingera Elatior

The large ornamental potential of tropical flowers has stimulated the commercial cultivation of various species. Micropropagation is a viable alternate method of propagation, since it enables obtaining a higher number of seedlings with uniformity and pathogens free. The objective was to evaluate the in vitro multiplication rate of Etlingera elatior cv. Porcelana, using explants obtained from in vitro established seedling shoots, obtained from the 2nd subcultive. The explants were inoculated in MS culture medium containing different concentrations of BAP (0.0; 2.22; 4.44; 6.66; 8.88; and 11,10 μM), and the cultures maintained in a growth room with temperature 25.0 ± 2.0 °C under a photoperiod of 12 hours of light and light intensity of 30 μmol.m-2 s-1. The multiplication rate was monthly, according to the four subcultives, totaling 120 days. The experimental design was completely randomized, with four replications, analyzed in a factorial 4 x 6. The data were submitted to analysis of variance and regression. There were significant differences in subcultives and made for BAP concentrations used. For the first subcultive, the concentration of 2.22 μM of BAP afforded a rate of 4.06 sprouts per explant, already in the second and fourth subcultives, with the addition of cytokinin concentration was increased amount of sprouts reaching at a rate of 4.05 and 4.96 shoots/explant in the highest concentration of BAP. The results of the treatments evaluated indicate that the presence of BAP favored sprout emission. The concentrations of 2.22, 8.88 and 11.10 μM this cytokinin promoted the highest multiplication rates in the first, second and fourth subcultives, respectively.

scholarly journals Phototaxis of Fungus Gnat, Bradysia sp. nr coprophila (Lintner) (Diptera: Sciaridae), Adults to Different Light Intensities

HortScience ◽  
2007 ◽  
Vol 42 (5) ◽  
pp. 1217-1220 ◽  
Author(s):  
Raymond A. Cloyd ◽  
Amy Dickinson ◽  
Richard A. Larson ◽  
Karen A. Marley
Keyword(s):  
Light Intensity ◽  
Light Source ◽  
Photosynthetically Active Radiation ◽  
Management Strategy ◽  
Detection Threshold ◽  
Multiple Choice ◽  
Active Radiation ◽  
Light Intensities ◽  
Fungus Gnats ◽  
Fungus Gnat

Multiple-choice experimental arenas, with sample compartments, were used to assess the response of fungus gnat, Bradysia sp. nr. coprophila (Lintner) (Diptera: Sciaridae), adults to varying light intensities in environmentally controlled walk-in chambers. Each sample compartment contained a yellow sticky card (2.5 × 2.5 cm) to capture fungus gnat adults. Under conditions of darkness, fungus gnat adults migrated randomly with no significant differences among the six sample compartments. Fungus gnat adults were observed to positively respond to light intensities less than 0.08374 μmol·m−2·s−1. In addition, adults responded to light intensities that were below the detection threshold of a photosynthetically active radiation light sensor. A higher percentage of fungus gnat adults (22% to 39%) were captured on yellow sticky cards in the sample compartments that were closest to a directional light source compared with sample compartments that were located further away from the light source (2% to 9%). Fungus gnat adults exhibited a significant response when exposed to two distinct ranges of light intensities (0.12 to 0.26 versus 0.87 to 1.02 μmol·m−2·s−1) with adults significantly more attracted to the highest light intensities (0.87 to 1.02 μmol·m−2·s−1). The results obtained in this study indicate that fungus gnat adults are positively phototactic, and as light intensity increases, they display a preference for those higher light intensities. It is possible that modifications in light intensity may be a feasible management strategy for alleviating problems with fungus gnats in greenhouses.

scholarly journals Estimation of The Physico-Chemical Parameters in Marine Environment (Yumurtalik Bight- Iskenderun Bay)

2016 ◽  
Vol 4 (2) ◽  
pp. 97
Author(s):  
Gökhan Tamer Kayaalp ◽  
Oya Işık ◽  
Benin Toklu Alıçlı
Keyword(s):  
Light Intensity ◽  
Analysis Of Variance ◽  
Chemical Properties ◽  
Effect Of Temperature ◽  
Chemical Parameters ◽  
Marine Life ◽  
Multiple Comparison Test ◽  
Physico Chemical ◽  
Iskenderun Bay ◽  
Dissolved O2

The study was carried out to estimate the temperature, light intensity, salinity, Dissolved O2 (DO), pH values and the biotic parameter chlorophyll- a in the water column related with the depth. Because, the physico-chemical parameters affect greatly both primary and secondary producers in marine life. For this purpose the physico-chemical properties were determined day and night for 40 meter depth during the eight days. The means were compared by using the analysis of variance method and Duncan’s Multiple Comparison Test. Also physico-chemical parameters were estimated by using the analysis of regression and correlation. The effect of temperature and salinity were found significant according to the result of the analysis of variance during the day. Also the similar results were found for the night. While the effect of the depth on the chloropyll-a a was significant in the night, the effect of the depth on the DO was not significant in the day and night. The correlations among the depth and the parameters were defined. It was found the negative correlation between the depth and the temperature and light intensity. Determination coefficient of the model for salinity was also found different for day time. The correlation values among the depth and the temperature, salinity and pH were found different for the night.

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