A PORTABLE LIGHT FRAME FOR ARTIFICIAL ILLUMINATION OF PLANTS

1962 ◽  
Vol 42 (1) ◽  
pp. 173-175
Author(s):  
Peter W. Voisey ◽  
W. Kalbfleisch

A portable high-intensity artificial light fixture was developed to secure the maximum in flexibility and utility in this type of expensive equipment. The frame is made of aluminum, the electrical switch gear is movable and the entire assembly can be located or installed at any location where there is a source of power.

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>


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).


1962 ◽  
Vol 40 (8) ◽  
pp. 1125-1135 ◽  
Author(s):  
T. Shiroya ◽  
G. R. Lister ◽  
G. Krotkov ◽  
C. D. Nelson ◽  
V. Slankis

Pinus strobus or P. resinosa seedlings, 2 or 3 years old, were illuminated in a closed chamber for 1 hour in the presence of C14O2. This was followed by various periods up to 24 hours under different conditions of light and darkness. Then each seedling was divided into its shoot, stem, and roots, and these were extracted separately with 80% ethanol. The extracts were resolved first on resins into sugar, amino acid, and organic acid fractions and then resolved further by paper chromatography. The C14 content of various fractions and of the eluted compounds was determined by plating and counting their aliquots. Ethanol-insoluble residue was oxidized and counted as BaC14O3.Eight hours after administration of the C14O2, 91 to 94% of the total C14 was found in the ethanol-soluble fractions of shoot, stem, or root. In shoots sugars were found to represent more than 95% of the ethanol-soluble photosynthate, with sucrose forming three-quarters of it. In stem and roots sucrose represented from 75 to 94% of the translocated photosynthate. Raffinose, glucose, and fructose were present in both stem and root.Seedlings with poorly developed root systems translocated less photosynthate to roots than those with good roots. Seedlings, which prior to the experiments were grown in full sunlight or 2500 ft-c artificial illumination translocated more photosynthate to roots than those grown in 6% of full sunlight or 250 ft-c artificial light. Stronger light during translocation itself also had a slight stimulatory effect.Seedlings, which were illuminated in the presence of C14O2 for 1 hour and then retained in a closed chamber for a further period of 7 hours, translocated a larger fraction of absorbed C14 to their roots than comparable seedlings transferred to air after feeding C14O2.


1972 ◽  
Vol 55 (3) ◽  
pp. 591-597 ◽  
Author(s):  
J. HERBERT

SUMMARY Removal of the pineal gland from ferrets kept entirely in daylight prevented the appearance of the normal annual oestrous rhythm. Animals were operated upon in the autumn; that is, at the start of their anoestrum. Oestrus in pinealectomized ferrets began at the usual time the following spring, as in control-operated and normal animals. However, during the second year after operation, pinealectomized ferrets came into oestrus 20–30 weeks after controls. Mean intervals between onsets of successive oestrous periods were: pinealectomized, 73·8 weeks (4 animals); control-operated, 52·9 weeks (7 animals); and normal animals, 52·5 weeks (10 animals). The duration of the oestrous period was not altered by removing the pineal. Three other pinealectomized ferrets kept in artificial photoperiods (14 h light: 10 h darkness) showed an oestrous rhythm indistinguishable from those pinealectomized and kept in daylight, whereas four controls that had also been put into artificial light showed greatly prolonged oestrous periods lasting more than a year. These experiments indicate that the pineal is concerned with timing the annual breeding season of ferrets in natural daylight as well as in artificial illumination. The anterior pituitary gland of pinealectomized ferrets seems unresponsive to either natural or artificial light under the conditions used in these studies. The duration of oestrus may be self-limited, but can be prolonged if the pineal gland is stimulated by the artificial 'long day'.


1857 ◽  
Vol 21 (3) ◽  
pp. 411-429 ◽  
Author(s):  
William Swan

The phenomena presented by the prismatic spectra of flames have occupied the attention of many and excellent investigators. In most instances, however, no attempt has been made to procure accurate measurements of the positions of the bright lines which many of the spectra exhibit; and much in this field of observation, therefore, remains to be accomplished. I purpose, from time to time as I shall have leisure, to make a series of observations, whose object shall be the actual numerical determination of the positions of the bright lines in the spectra of flames; and I have commenced the series with an examination of the spectra of the flames of compounds of carbon and hydrogen. In an investigation into the phenomena of flames, the compounds of carbon and hydrogen claim our first attention, as constituting the most important means of artificial illumination; for it is scarcely necessary to remark, that, with the grand exception of sun-light, the combustion of these substances is the source of nearly all the light and heat from which we derive such extensive benefits in the arts and in domestic economy. It will be found, moreover, that the spectra of carbohydrogen flames possess, in common, remarkable features, which seem as yet to have received little attention, but which promise to be of service in explaining the general phenomena of artificial light.


2021 ◽  
pp. 73-81
Author(s):  
Kirill A. Solovyov

The article is devoted to luminaires and the history of the development of artificial illumination. As you know, light is one of the human needs. At all stages of the development of human civilization, people have thought about how to use artificial light source if there is not enough daylight. That is why man constantly invented and improved certain light source, the framings of which we now call lighting device or luminaires. The stages of development and improvement of luminaires are a matter of separate serious scientific research. In this article, we are talking about how the development of lighting devices took place in different periods. In different epochs, luminaires corresponded to certain traditions and aesthetic views of certain architectural styles. That is why in his article the author pays great attention not only to the appearance of the described luminaires, but also to its architectural environment.


1995 ◽  
Vol 33 (2) ◽  
pp. 103-111 ◽  
Author(s):  
Masahisa ISHII ◽  
Tadashi ITO ◽  
Tooru MARUO ◽  
Keizoh SUZUKI ◽  
Kohzoh MATSUO

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Michiel P. Boom ◽  
Kamiel Spoelstra ◽  
Arjen Biere ◽  
Eva Knop ◽  
Marcel E. Visser

Abstract Rapid human population growth and associated urbanization lead to increased artificial illumination of the environment. By changing the natural light–dark cycle, artificial lighting can affect the functioning of natural ecosystems. Many plants rely on insects in order to reproduce but these insects are known to be disturbed by artificial light. Therefore, plant–insect interactions may be affected when exposed to artificial illumination. These effects can potentially be reduced by using different light spectra than white light. We studied the effect of artificial lighting on plant–insect interactions in the Silene latifolia–Hadena bicruris system using a field set-up with four different light treatments: red, green, white and a dark control. We compared the proportion of fertilized flowers and fertilized ovules as well as the infestation of fruits by Hadena bicruris, a pollinating seed predator. We found no difference in the proportion of fertilized flowers among the treatments. The proportion of fruits infested by H. bicruris was however significantly higher under green and white light and a significantly lower proportion of fertilized ovules was found under green light. We show that artificial light with different colours impacts plant–insect interactions differently, with direct consequences for plant fitness.


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.


1993 ◽  
Vol 23 (1) ◽  
pp. 101-110 ◽  
Author(s):  
Daniel Lord ◽  
Sylvain Morissette ◽  
Jacques Allaire

Growth of containerized black spruce seedlings grown in greenhouses was studied in relation to factors known to influence plant growth. Artificial light intensity (3.80 and 72.04 μmol•m−2•s−1) and night air temperature (5, 10, 12.5, 15, and 20 °C) were considered in a first experiment and artificial light intensity (4.24 and 59.57 μmol•m−2•s−1) and CO2 air concentration (ambient and 1000 μL•L−1) in a second one. Higher light intensity and CO2 enrichment increased dry biomass of seedlings as well as growth in height and stem diameter. Both factors similarly enhanced the last two parameters since height/diameter ratios showed little variation among treatments. Reducing night air temperature down to 10 °C did not significantly influence height growth nor biomass increase when high intensity light was provided. Lower light intensity raised the threshold to 12.5 °C. Shoot height, diameter, and dry biomass as well as the number of branches and buds per millimeter were strongly reduced by a 5 °C night air temperature. High intensity light enhanced growth of containerized black spruce seedlings more than CO2 enrichment or a 5 °C night air temperature. When used simultaneously, these growth enhancing factors had a synergistic effect during most of the treatment period; thereafter, the effect became partially additive. The relative growth rate peaked at the onset of exponential shoot growth and decreased after this point. However, the enhancing factors were still efficient since absolute growth differences between seedlings grown under the most favorable conditions and controls kept increasing. The faster growing pace imposed by these growth enhancing conditions during the treatment period was maintained over the entire first growing season.


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