EXPERIMENTS WITH ARTIFICIAL LIGHT: NECESSITY FOR PROPERLY IDENTIFYING THE SOURCE

1982 ◽  
Vol 114 (4) ◽  
pp. 377-379 ◽  
Author(s):  
Bernard J. R. Philogène

The use of artificial illumination in entomological studies is extensive. Incandescent and fluorescent lights are used in mass-rearing insects necessary for physiological and ecological studies, and in photoperiod-controlled as well as in electrophysiological experiments.One of the main problems facing investigators in the interpretation of their results or in comparing these to preceding reports is the plethora of ways in which experimental conditions involving light are reported. Here are some examples: “The ants were kept under fluorescent light from 0800 to 2000 hours; light intensity on the ants was about 400 lux” (McCluskey 1965).

HortScience ◽  
1990 ◽  
Vol 25 (5) ◽  
pp. 547-549 ◽  
Author(s):  
Yolanta Saks ◽  
Lilian Sonego ◽  
Ruth Ben-Arie

Mature-green `Anna' apples (Malus domestics Borkh.) reddened after harvest as a result of exposure to continuous cool-white fluorescent light. Color development was most rapid at 20C but most intense at 13C. At 2C, although the induction of red pigmentation was the slowest, a 72-hr exposure rendered color not significantly different from that of red, commercially harvested fruit. The development of color was light-intensity dependent, approaching saturation at 14.5 W·m-2 (at 13 C). No differences in fruit ripening were found between fruit that developed color under artificial light and red fruit from the commercial harvest, in spite of some stimulation of ethylene production during illumination.


1962 ◽  
Vol 42 (3) ◽  
pp. 510-514 ◽  
Author(s):  
Peter W. Voisey

To provide both natural light and artificial light for plant growth, a cabinet with glass on the side walls and top was designed for use in a greenhouse. The cabinet measures 5 feet by 7.5 feet and 5 feet high over-all. It has refrigeration cooling, electric heating and electronic temperature controls for a range of 25 to 100°F. Temperature control is regulated at ±0.5°F. while the maximum variation between different locations in the cabinet is ±2°F. Humidity is maintained by a humidifier installed in the cabinet. The light intensity from fluorescent and incandescent bulbs is 2,000 foot-candles in the center of the cabinet.


1969 ◽  
Vol 47 (7) ◽  
pp. 1153-1156 ◽  
Author(s):  
J. A. Ekundayo ◽  
R. H. Haskins

Cultures of Botryodiplodia theobromae Pat. produced pycnidia abundantly on several media under continuous irradiation with fluorescent light. The fungus did not sporulate when grown in darkness. Irradiation of cultures with a light intensity of 15 foot-candles for 4 days was sufficient to stimulate pycnidial production, but for appreciable sporulation to occur over the same exposure period, higher light intensities are required. Irradiation of cultures through glass color filters showed that long-wave ultraviolet radiation stimulated sporulation.


1983 ◽  
Vol 69 (4) ◽  
pp. 305-308 ◽  
Author(s):  
Franco Zunino ◽  
Renato Marchesini ◽  
Elsa Melloni ◽  
Giuseppina Savi ◽  
Gabriella Pezzoni ◽  
...  

The effectiveness of laser photoradiation therapy with hematoporphyrin derivative sensitization was tested in the MS-2 sarcoma. This solid tumor, transplanted into the pad of the hind leg of BALB/c mice, was found to be a sensitive experimental model for a quantitative evaluation of response to phototherapy and for determination of critical parameters in laser phototherapy treatment. Under our experimental conditions, optimal therapeutic effects appeared to be critically dependent on drug dose, number of treatments, light intensity, and irradiation of the peripheral border of the tumor.


Author(s):  
Ayman Y. Al-Rawashdeh ◽  
Omar Albarbarawi ◽  
Ghazi Qaryouti

<p>In this case study, two polycrystalline solar modules were installed outdoors (irradiated by sunlight) and indoors (irradiated by artificial lights). The solar cells in both cases were installed using different color filters that allowed the passage of certain light frequencies. The amount of energy produced by each module were measured and compared to a reference module with no filter. The results indicated the variable response of polycrystalline solar cells to natural and artificial light sources, being more responsive in both cases to red band color as could be deduced from their % current outputs (72.5% sunlight radiation; 84.38% artificial light sources). Other colors, including yellow, green, orange and violet afforded acceptable outputs. The results indicated that electrical outputs of indoor solar cells decreased when colored filters were used, but red filter in general afforded the maximum outputs, for both the artificially radiated indoor and naturally radiated outdoor solar cells. The case study suggests the possible complementary advantage of using indoor mounted solar cells for the production of electricity during artificial illumination period of the day.</p>


2019 ◽  
Vol 11 (8) ◽  
pp. 188
Author(s):  
Lucas Aparecido Manzani Lisboa ◽  
Amanda Stelutti ◽  
Karla Caroline Santana Lima ◽  
Guilherme Bandeca Rafachinho ◽  
Renata Alari Chedid ◽  
...  

Luminosity and temperature are factors that directly act in photosynthetic process, in which the elevation of the light intensity may provoke reduction in the assimilation of carbon, impairing the development of the soybean culture. This work aimed to know physiological parameters of soybean (Glycine max L. Merr.) under different intensities of artificial light. The experiment was carried out in randomized blocks, in a factorial scheme 2 &times; 5, being two soybean cultivars (Pot&ecirc;ncia and NS6700) and five densities of light: 0 (control), 500, 1000, 1500 and 2000 &mu;mol m-2 s-1 of photosynthetically active radiation (PAR) provided by LED bulbs, with 4 repetitions, in total of 40 plots. The following variables were set: rate of CO2 assimilation (A), transpiration (E), stomatal conductance (gs), inner CO2 concentration in the substomatic chamber (Ci) and water use efficiency (WUE) in which a portable device of gas exchange was used (Infra-Red Gas Analyzer-IRGA, marca ADC BioScientific Ltd, modelo LC-Pro). Seedlings of soybean positively responded under different intensities of artificial light till reach the maximum saturation point between 1400 and 1600 &micro;mol m-1 s-1 of light, which promoted a better rate of A, Ci andWUE. E and gs presented positive linear responses by increasing the intensity of artificial light. The ideal light intensity to the use of Infra-Red Gas Analyzer-IRGA between 1400 and 1600 &micro;mol m-1 s-1 to the soybean culture.


2018 ◽  
Vol 13 (9) ◽  
pp. 921-931 ◽  
Author(s):  
Coralie English ◽  
Heidi Janssen ◽  
Gary Crowfoot ◽  
Robin Callister ◽  
Ashlee Dunn ◽  
...  

Objectives People with stroke sit for long periods each day, which may compromise blood glucose control and increase risk of recurrent stroke. Studies in other populations have found regular activity breaks have a significant immediate (within-day) positive effect on glucose metabolism. We examined the effects of breaking up uninterrupted sitting with frequent, short bouts of light-intensity physical activity in people with stroke on post-prandial plasma glucose and insulin. Methods Randomized within-participant crossover trial. We included people between 3 months and 10 years post-stroke, ambulant with minimal assistance and not taking diabetic medication other than metformin. The three experimental conditions (completed in random order) were: sitting for 8 h uninterrupted, sitting with 3 min bouts of light-intensity exercise while standing every 30 min, or sitting with 3 min of walking every 30 min. Meals were standardized and bloods were collected half- to one-hourly via an intravenous cannula. Results A total of 19 participants (9 female, mean [SD] age 68.2 [10.2]) completed the trial. The majority ( n = 12, 63%) had mild stroke symptoms (National Institutes of Stroke Scale score 0–13). There was no significant effect of experimental condition on glucose (mean [SD] positive incremental area [+iAUC] mmol·L·h-1 under the curve during sitting 42.3 [29.5], standing 47.4 [23.1], walking 44.6 [26.5], p = 0.563) or insulin (mean + iAUC pmol·L·h-1 sitting 14,161 [7,560], standing 14,043 [8,312], walking 14,008 [8,269], p = 0.987). Conclusion Frequent, short bouts of light-intensity physical activity did not have a significant effect on post-prandial plasma glucose and insulin in this sample of people with stroke. Further studies are needed to identify strategies that improve inactivity-related glucose metabolism after stroke.


2019 ◽  
Vol 33 (12) ◽  
pp. 1950110
Author(s):  
Muhammad Riaz ◽  
Khasan S. Karimov ◽  
Jameel-Un Nabi

The temperature dependences of resistance, impedance and capacitance of semitransparent sensor having structure ITO/PTB7-Th:PC[Formula: see text]BM/Graphene composite (semisurface type) were investigated. The transparency of the sensor was 58–60%. The dependences of the resistance, impedance and capacitance at different frequencies 100 Hz, 1 kHz, 10 kHz, 100 kHz and 200 kHz and temperature in the range of 23.8–80[Formula: see text]C for the sensor were studied. It was observed that as the temperature increased from 23.8[Formula: see text]C to 80[Formula: see text]C, the resistance and impedance (at 1 kHz) of the samples decreased, on average, by a factor of 3.51 and 3.79, respectively. At same experimental conditions (1 kHz), the capacitances of the samples also decreased by a factor of 9.6. It was also noted that as frequency increased from 100 Hz to 200 kHz, the impedance of the sensor decreased by a factor of 21 and 12, at temperatures 24[Formula: see text]C and 58[Formula: see text]C, respectively. Under the same conditions, the capacitance decreased by a factor of 30 and 28, respectively. The temperature resistance coefficients were measured to be −1.31%/[Formula: see text]C, −1.30%/[Formula: see text]C, −1.27%/[Formula: see text]C, −0.84%/[Formula: see text]C, −0.72%/[Formula: see text]C and −0.33%/[Formula: see text]C for R, Z (100 Hz), Z (1 kHz), Z (10 kHz), Z (100 kHz) and Z (200 kHz), respectively. For capacitance measurement, the temperature capacitance coefficients were measured as −1.39%/[Formula: see text]C, −1.38%/[Formula: see text]C, −1.37%/[Formula: see text]C, −1.36%/[Formula: see text]C and −1.34%/[Formula: see text]C, respectively. The semitransparent PTB7-Th- and PC[Formula: see text]BM-based temperature sensor can be used for measurement of the temperature as a teaching aid in situations where visual control of illumination and light intensity is required.


Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1553 ◽  
Author(s):  
Jae Hong Park ◽  
Dong Seok Shin ◽  
Jae Kwan Lee

Animal wastewater is one of the wastewaters that has a color and is difficult to treat because it contains a large amount of non-degradable organic materials. The photo-assisted Fenton oxidation technique was applied to treat animal wastewater, and the optimal conditions of chemical oxygen demands (COD) removal were analyzed according to changes in pH, ferrous ion, H2O2, and ultraviolet (UV) light intensity as a single experimental condition. Experimental results showed that, under the single-factor experimental conditions, the optimal conditions for degradation of animal wastewater were pH 3.5, Fe(II) 0.01 M, H2O2 0.1 M, light intensity 3.524 mW/m2. Under the optimal conditions, COD removal efficiency was 91%, sludge production was 2.5 mL from 100 mL of solution, color removal efficiency was 80%, and coliform removal efficiency was 99.5%.


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