The preferences of hens for compact fluorescent over incandescent lighting

1992 ◽  
Vol 72 (2) ◽  
pp. 203-211 ◽  
Author(s):  
Tina M. Widowski ◽  
Linda J. Keeling ◽  
Ian J. H. Duncan

To determine whether laying hens find the flicker of fluorescent light aversive, their preferences were tested individually in a two-room testing chamber in which each room could be illuminated by either incandescent or fluorescent lights. The rooms were joined by a central compartment which acted as a light baffle and through which the birds could easily pass. The level of illumination in the two rooms was carefully matched and other resources such as food, water and nest-boxes were available in both rooms. The preferences of 16 mature light hybrid hens which had experience of both fluorescent and incandescent lighting were recorded during a 6-h test period on each of 2 d with the light sources in the rooms being switched on the second day. Overhead video cameras recorded the position and the behaviour of the birds throughout testing. On each of the test days, the hens spent significantly more time in fluorescent light than they did in incandescent light (each day: P < 0.01). When data from both test days were combined, the birds spent on average 73.2% of their time under fluorescent light and only 26.8% under incandescent (P < 0.001). Frequency distributions of ingestive behaviour, nesting, preening, resting and walking indicated that the birds performed all activities in both rooms and in both types of light. These results indicate that the birds either did not perceive the flicker of the fluorescent lights or perceived the flicker and did not find it aversive, and that they found some aspect of the fluorescent light more attractive than incandescent. Key words: Lighting, fluorescent, incandescent, behaviour, poultry

1996 ◽  
Vol 76 (2) ◽  
pp. 177-181 ◽  
Author(s):  
T. M. Widowski ◽  
I.J.H. Duncan

To determine whether hens find the flicker of some fluorescent light aversive, the preferences of 16 light hybrid laying hens for light produced by high-frequency or low-frequency compact fluorescent lamps were tested individually in a two-room testing chamber in which each room could be illuminated by either source. The spectral distributions of the lamps and levels of illumination (ca. 14 lx) in the two rooms were carefully matched and both rooms contained feed, water, and a nesting area. Overhead video cameras recorded the position and behaviour of the birds during a 6-h test period on each of 2 d. The light sources in the rooms were switched on the second test day to balance for any preferences for chamber room.On both test days, the birds spent similar amounts of time in fluorescent light produced by high-frequency and low-frequency lamps (P > 0.10). When data from both test days were combined, the birds spent on average 48.2% of time in light from high-frequency lamps and 51.8% from low-frequency. The frequency distributions of individual activities indicated that the birds performed all activities in light produced by both types of lamps. The results indicate that the laying hens in this experiment did not exhibit a preference for high-frequency fluorescent lamps over low-frequency lamps. We conclude that at the illumination levels used in this experiment, the hens did not perceive the flicker of low-frequency light or they perceived it but did not find it aversive. Low-frequency fluorescent light does not appear to adversely affect the welfare of hens. Key words: Lighting, fluorescent, flicker, behaviour, poultry


2014 ◽  
Vol 34 (3) ◽  
pp. 428-434 ◽  
Author(s):  
Karla A. O. Lima ◽  
Irenilza de A. Nääs ◽  
Rodrigo G. Garcia ◽  
Rodrigo Borille ◽  
Fabiana R. Caldara

Broiler production is highly dependent on the use of artificial light. The light source may affect the effectiveness of housing conditions due to increasing ambient temperature and concentration of noxious gases. This research aimed to evaluate the effects of different bulb types on the thermal, aerial, and acoustic environment of broiler aviaries. The experiment was carried out at a commercial broiler farm in Dourados, Mato Grosso do Sul State, Brazil. Three aviaries were used, and two flocks of male broilers from Cobb® genetic strain were reared from the first day to slaughter. Each aviary was equipped with a different light source, comprising the adopted treatments (A1 - incandescent light bulb, control; A2 - sodium vapor light bulb; A3 - fluorescent light bulb). The aviaries were divided into nine quadrants, and the environmental data (ambient dry bulb temperature and relative humidity), litter surface temperature, CO2 and NH3 concentrations, and bird sound pressure behavior were recorded in each quadrant. The aviary with incandescent light presented higher air and litter temperatures, and concentration of gases than the other tested alternatives. It also presented higher level of sound pressure in the second week of the growing period; however, from this period up to slaughter, there was no effect of the light source on the results of broiler sound pressure level.


2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Xin Li ◽  
Xu Chen ◽  
Guo-Quan Lu

As a solid electroluminescent source, white light emitting diode (LED) has entered a practical stage and become an alternative to replace incandescent and fluorescent light sources. However, due to the increasing integration and miniaturization of LED chips, heat flux inside the chip is also increasing, which puts the packaging into the position to meet higher requirements of heat dissipation. In this study, a new interconnection material—nanosilver paste is used for the LED chip packaging to pursue a better optical performance, since high thermal conductivity of this material can help improve the efficiency of heat dissipation for the LED chip. The bonding ability of this new die-attach material is evaluated by their bonding strength. Moreover, high-power LED modules connected with nanosilver paste, Sn3Ag0.5Cu solder, and silver epoxy are aged under hygrothermal aging and temperature cycling tests. The performances of these LED modules are tested at different aging time. The results show that LED modules sintered with nanosilver paste have the best performance and stability.


1961 ◽  
Vol 41 (2) ◽  
pp. 418-427 ◽  
Author(s):  
D. J. C. Friend ◽  
V. A. Helson ◽  
J. E. Fisher

When Marquis wheat is grown under artificial conditions, the main light energy (lamp watts) supplied by fluorescent light should be supplemented by at least 35 per cent of incandescent light in order to have a photoperiodic effect close to the maximal. Increasing the percentage up to 100 per cent resulted in slightly earlier flowering. This effect of incandescent light was caused, not by earlier floral initiation, but by an increase in the rate of stem elongation and a hastening of the later stages of floral differentiation. This action of incandescent light could not be replaced by substituting pink fluorescent for one-third of the white fluorescent lights.To obtain a photoperiodic effect equal to that of high light energy from combined fluorescent and incandescent bulbs, it is recommended that the daylength be extended by sufficient incandescent light to give an intensity of at least 50 ft.-c. at plant level.


Inorganics ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 84
Author(s):  
David Böhnisch ◽  
Juri Rosenboom ◽  
Thomas Jansen ◽  
Thomas Jüstel

Since the invention of fluorescent light sources, there is strong interest in Eu3+ activated phosphors as they are able to provide a high color rendering index (CRI) and luminous efficacy, which will also hold for phosphor converted light emitting diodes. Due to an efficient U6+ to Eu3+ energy transfer in Gd3Li3Te2O12:U6+,Eu3+, this inorganic composition shows red photoluminescence peaking at 611 nm. That means Eu3+ photoluminescence can be nicely sensitized via excitation into the U6+ excitation bands. Therefore, photoluminescence properties, such as temperature dependent emission and emission lifetime measurements, are presented. Charge transfer bands were investigated in detail. Additionally, density functional theory calculations reveal the band structure of the pure, i.e., non-doped host material. Obtained theoretical results were evaluated experimentally by the aid of diffuse UV reflectance spectroscopy.


Author(s):  
Sylvain Chaminade ◽  
Jean Toutain ◽  
Stefan Dilhaire ◽  
Eric Arquis ◽  
Christine Marraud ◽  
...  

We studied the air bubble behavhiour in viscous flows. A one-way coupling model was developed, based on lagrangian method. In order to validate this model, experiments were carried out. Our experimental installation was based on shadow visualization method. Bubbles were introduced in a transparent Plexiglas tank filling with viscous fluid (e.g. silicon oil) and were illuminated by diffused lights. In order to reconstruct 3D-trajectories, two video cameras, orthogonally placed, took pictures of shape bubbles and a post treatment of images acquired allowed us to determine the position of the center and the radius of each bubble. Thus, from this information of each plane, we could determine the 3D parameters of bubbles. Superluminescent LEDs with different wave-lengths were used as light sources. The choice of the wavelengths for each plane illumination and the selection of appropriated RGB filter of CCD sensor allowed us to prevent dissymmetry of bubble shape which was due to parasitic orthogonal illumination. Numerical results agree with experimental data.


2015 ◽  
Vol 2015 ◽  
pp. 1-19 ◽  
Author(s):  
Asmaa M. El-Said ◽  
Ali I. Eldesoky ◽  
Hesham A. Arafat

Tremendous growth in the number of textual documents has produced daily requirements for effective development to explore, analyze, and discover knowledge from these textual documents. Conventional text mining and managing systems mainly use the presence or absence of key words to discover and analyze useful information from textual documents. However, simple word counts and frequency distributions of term appearances do not capture the meaning behind the words, which results in limiting the ability to mine the texts. This paper proposes an efficient methodology for constructing hierarchy/graph-based texts organization and representation scheme based on semantic annotation andQ-learning. This methodology is based on semantic notions to represent the text in documents, to infer unknown dependencies and relationships among concepts in a text, to measure the relatedness between text documents, and to apply mining processes using the representation and the relatedness measure. The representation scheme reflects the existing relationships among concepts and facilitates accurate relatedness measurements that result in a better mining performance. An extensive experimental evaluation is conducted on real datasets from various domains, indicating the importance of the proposed approach.


Author(s):  
John D. Bullough

Light-emitting diodes (LEDs) differ from incandescent light sources in several ways that are relevant to energy and maintenance requirements of airfield lighting systems. They have higher luminous efficacy and, when designed properly, have longer useful operating lives; both factors make LEDs attractive candidates for airfield lighting. The photometric, colorimetric, and temporal characteristics of LEDs also differ from those of incandescent light sources, and these can have important implications for the appearance of runway and taxiway lighting systems. The present paper reviews publications summarizing experimental and analytical investigations designed to assess these implications with respect to the following human factors impacts: color identification, brightness and glare, visibility in fog and haze, response to onset of flashing lights, and stroboscopic effects such as the phantom array. Overall, this review of experimental evidence suggests that, in addition to their reduced energy use and maintenance requirements, LED airfield lighting can be advantageous in comparison with incandescent lighting systems used to delineate airport runways and taxiways.


2010 ◽  
Author(s):  
Anatoliy Y. Vorobyev ◽  
Chunlei Guo

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