Laying hens do not have a preference for high-frequency versus low-frequency compact fluorescent light sources

1996 ◽  
Vol 76 (2) ◽  
pp. 177-181 ◽  
Author(s):  
T. M. Widowski ◽  
I.J.H. Duncan
Keyword(s):  
High Frequency ◽  
Laying Hens ◽  
Low Frequency ◽  
Fluorescent Light ◽  
Feed Water ◽  
Light Sources ◽  
Frequency Distributions ◽  
Video Cameras ◽  
Fluorescent Lamps ◽  
Testing Chamber

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

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
Keyword(s):  
Key Words ◽  
Central Compartment ◽  
Fluorescent Light ◽  
Light Sources ◽  
Frequency Distributions ◽  
Incandescent Light ◽  
Video Cameras ◽  
Nest Boxes ◽  
Testing Chamber ◽  
Ingestive Behaviour

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

Choice Between Fluorescent and Poultry-Specific LED Lights by Pullets and Laying Hens

2017 ◽  
Vol 60 (6) ◽  
pp. 2185-2195 ◽  
Author(s):  
Kai Liu ◽  
Hongwei Xin ◽  
Lilong Chai
Keyword(s):  
Feed Intake ◽  
Laying Hens ◽  
Light Emitting Diode ◽  
Preference Assessment ◽  
Preference Test ◽  
Well Being ◽  
Production Performance ◽  
Color Temperature ◽  
Fluorescent Light ◽  
Light Sources

Abstract. Light plays an important role in poultry development, production performance, health, and well-being. Light technology continues to advance, and accordingly new light products are finding applications in poultry operations. However, research concerning responses of young and adult laying hens to light sources is relatively lacking. This study assessed the choice between a Dim-to-Red poultry-specific light-emitting diode (LED) light (PS-LED, correlated color temperature or CCT = 2000K) and a warm-white fluorescent light (FL, CCT = 2700K) by pullets and laying hens (W-36 breed) via preference test. Birds with different prior lighting experiences were evaluated for their light choice, including (1) pullets (14 to 16 weeks of age or WOA) reared under incandescent light (designated as PINC), (2) layers (44 to 50 WOA) under PS-LED (LLED) throughout the pullet and laying phases, and (3) layers under FL (LFL) throughout the pullet and laying phases. Each bird category consisted of 12 replicates, three birds per replicate. Each replicate involved a 6-day preference test, during which the birds could move freely between two interconnected compartments that contained PS-LED and FL, respectively. Time spent and feed intake by the birds under each light were measured and then analyzed with generalized linear mixed models. Results showed that regardless of prior lighting experience, birds in all cases showed stronger choice for FL (p = 0.001 to 0.030), as evidenced by higher proportions of time spent under it. Specifically, the proportion of time spent (mean ±SEM) under FL versus PS-LED was 58.0% ±2.9% vs. 42.0% ±2.9% for PINC, 53.7% ±1.6% vs. 46.3% ±1.6% for LLED, and 54.2% ±1.2% vs. 45.8% ±1.2% for LFL. However, the proportions of daily feed intake occurring under FL and PS-LED were comparable in all cases (p = 0.419 to 0.749). The study thus reveals that prior lighting experience of the pullets or layers did not affect their choice of FL versus PS-LED. While the birds exhibited a somewhat stronger choice for FL, this tendency did not translate into differences in the proportion of feed use under each light type. Keywords: Behavior and welfare, Computer vision, Poultry Lighting, Preference assessment.

Effect of repetitive visual stimuli on behaviour and plasma corticosterone of European starlings

2005 ◽  
Vol 55 (3) ◽  
pp. 245-258 ◽  
Author(s):  
◽  
◽  
◽  
Keyword(s):  
Spatial Frequency ◽  
High Frequency ◽  
Temporal Frequency ◽  
Low Frequency ◽  
High Spatial Frequency ◽  
Plasma Corticosterone ◽  
European Starlings ◽  
Fluorescent Lamps ◽  
Spatial Frequencies ◽  
Temporal And Spatial

AbstractFlickering light can cause adverse effects in some humans, as can rhythmic spatial patterns of particular frequencies. We investigated whether birds react to the temporal frequency of standard 100 Hz fluorescent lamps and the spatial frequency of the visual surround in the manner predicted by the human literature, by examining their effects on the preferences, behaviour and plasma corticosterone of European starlings (Sturnus vulgaris). We predicted that high frequency lighting (> 30 kHz) and a relatively low spatial frequency on the walls of their cages (0.1 cycle cm−1) would be less aversive than low frequency lighting (100 Hz) and a relatively high spatial frequency (2.5 cycle cm−1). Birds had strong preferences for both temporal and spatial frequencies. These preferences did not always fit with predictions, although there was evidence that 100 Hz was more stressful than 30 kHz lighting, as birds were less active and basal corticosterone levels were higher under 100 Hz lighting. Our chosen spatial frequencies had no overall significant effect on corticosterone levels. Although there are clearly effects of, and interactions between, the frequency of the light and the visual surround on the behaviour and physiology of birds, the pattern of results is not straightforward.

scholarly journals The Influence of a Photovoltaic Micro-Installation on the Low-Frequency Parameters of Electricity at PCC and Its Impact on the Thermal Characteristics of Selected Devices

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2355
Author(s):  
Stanislaw Galla ◽  
Miroslaw Wlas
Keyword(s):  
Low Frequency ◽  
Thermal Characteristics ◽  
Fluorescent Light ◽  
Light Sources ◽  
Dc Power ◽  
Measurement Results ◽  
Point Of Common Coupling ◽  
Voltage Harmonics ◽  
Research Recommendations

This manuscript illustrates the measurement results of parameters describing the quality of energy at the PCC (point of common coupling) of a photovoltaic micro-installation that can significantly affect devices in the same power grid. The analyses reflecting heating of selected devices used in domestic installations, which were performed in an isolated laboratory environment, are also indicated. The conducted study aimed at checking the thermal characteristics of the chosen equipment, i.e., AC/DC power supply, LED and fluorescent light sources, a step-down transformer at synergistically higher voltage harmonics and constant component in the network voltage. The tests were carried out at the disturbance levels recorded at the site of the photovoltaic micro-installation. The conducted tests aimed at indicating the presence of an increased level of synergetic disturbances in the vicinity of micro-photovoltaic installations. Based on the research, recommendations were made for photovoltaic micro-installations.

Wattage-independent dynamic conductance model of compact fluorescent lamps: Validation and application in high-frequency operation

2017 ◽  
Vol 50 (7) ◽  
pp. 1107-1123
Author(s):  
B Gupta Bakshi ◽  
B Roy
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Electrical Performance ◽  
Design Parameters ◽  
Matlab Simulink ◽  
Resonant Inverter ◽  
Fluorescent Lamps ◽  
High Frequency Operation ◽  
Compact Fluorescent Lamp ◽  
Inverter Topology

A wattage-independent (7–18 W) compact fluorescent lamp (CFL) model has been developed in Matlab-Simulink and validated in low-frequency (50 Hz) operation in our earlier work. In this paper, the same lamp model is simulated for high-frequency operation and then validated experimentally with a 9 W test CFL driven by a compatible electronic ballast (e-ballast). Simulation results have shown a maximum 6.4% deviation compared to the measured data. Thereafter, the developed model is applied to obtain the arc resistance versus power and power versus frequency characteristics of CFLs required to design dimmable e-ballasts. An algorithm is developed to compute design parameters of a dimmable e-ballast based on voltage-fed series-parallel resonant inverter topology. The electrical performance of the designed e-ballast is simulated at three different power levels (100%, 75% and 50%) using Matlab-Simulink.

Simulations of high-resolution images of amorphous silicon films

1986 ◽  
Vol 44 ◽  
pp. 544-545
Author(s):  
G. Y. Fan ◽  
J. M. Cowley
Keyword(s):  
Electron Microscope ◽  
High Frequency ◽  
Fourier Transformation ◽  
Amorphous Materials ◽  
Low Frequency ◽  
Chromatic Aberration ◽  
Structure Information ◽  
Frequency Components ◽  
High Resolution Images ◽  
Spatial Frequency Spectrum

It is well known that the structure information on the specimen is not always faithfully transferred through the electron microscope. Firstly, the spatial frequency spectrum is modulated by the transfer function (TF) at the focal plane. Secondly, the spectrum suffers high frequency cut-off by the aperture (or effectively damping terms such as chromatic aberration). While these do not have essential effect on imaging crystal periodicity as long as the low order Bragg spots are inside the aperture, although the contrast may be reversed, they may change the appearance of images of amorphous materials completely. Because the spectrum of amorphous materials is continuous, modulation of it emphasizes some components while weakening others. Especially the cut-off of high frequency components, which contribute to amorphous image just as strongly as low frequency components can have a fundamental effect. This can be illustrated through computer simulation. Imaging of a whitenoise object with an electron microscope without TF limitation gives Fig. 1a, which is obtained by Fourier transformation of a constant amplitude combined with random phases generated by computer.

SEM image sharpness analysis

1996 ◽  
Vol 54 ◽  
pp. 142-143
Author(s):  
M. T. Postek ◽  
A. E. Vladar
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Quantitative Information ◽  
Primary Electron ◽  
Image Sharpness ◽  
Critical Dimensions ◽  
Sem Image ◽  
Frequency Changes ◽  
Electron Microscopes ◽  
Scanning Electron

Fully automated or semi-automated scanning electron microscopes (SEM) are now commonly used in semiconductor production and other forms of manufacturing. The industry requires that an automated instrument must be routinely capable of 5 nm resolution (or better) at 1.0 kV accelerating voltage for the measurement of nominal 0.25-0.35 micrometer semiconductor critical dimensions. Testing and proving that the instrument is performing at this level on a day-by-day basis is an industry need and concern which has been the object of a study at NIST and the fundamentals and results are discussed in this paper.In scanning electron microscopy, two of the most important instrument parameters are the size and shape of the primary electron beam and any image taken in a scanning electron microscope is the result of the sample and electron probe interaction. The low frequency changes in the video signal, collected from the sample, contains information about the larger features and the high frequency changes carry information of finer details. The sharper the image, the larger the number of high frequency components making up that image. Fast Fourier Transform (FFT) analysis of an SEM image can be employed to provide qualitiative and ultimately quantitative information regarding the SEM image quality.

Real Ear Sound Pressure Levels Developed by Three Portable Stereo System Earphones

1992 ◽  
Vol 1 (4) ◽  
pp. 52-55 ◽  
Author(s):  
Gail L. MacLean ◽  
Andrew Stuart ◽  
Robert Stenstrom
Keyword(s):  
High Frequency ◽  
Sound Pressure ◽  
Low Frequency ◽  
Test System ◽  
Output Frequency ◽  
Frequency Effects ◽  
Adult Men ◽  
Frequency Responses ◽  
Significant Difference ◽  
Sound Pressure Levels

Differences in real ear sound pressure levels (SPLs) with three portable stereo system (PSS) earphones (supraaural [Sony Model MDR-44], semiaural [Sony Model MDR-A15L], and insert [Sony Model MDR-E225]) were investigated. Twelve adult men served as subjects. Frequency response, high frequency average (HFA) output, peak output, peak output frequency, and overall RMS output for each PSS earphone were obtained with a probe tube microphone system (Fonix 6500 Hearing Aid Test System). Results indicated a significant difference in mean RMS outputs with nonsignificant differences in mean HFA outputs, peak outputs, and peak output frequencies among PSS earphones. Differences in mean overall RMS outputs were attributed to differences in low-frequency effects that were observed among the frequency responses of the three PSS earphones. It is suggested that one cannot assume equivalent real ear SPLs, with equivalent inputs, among different styles of PSS earphones.

Evaluation of Special Hearing Aids for Deaf Children

1971 ◽  
Vol 36 (4) ◽  
pp. 527-537 ◽  
Author(s):  
Norman P. Erber
Keyword(s):  
Hearing Aids ◽  
High Frequency ◽  
Hearing Aid ◽  
Low Frequency ◽  
Acoustic Stimulation ◽  
Deaf Children ◽  
Frequency Range ◽  
Frequency Limit ◽  
Unpublished Studies ◽  
Published Research

Two types of special hearing aid have been developed recently to improve the reception of speech by profoundly deaf children. In a different way, each special system provides greater low-frequency acoustic stimulation to deaf ears than does a conventional hearing aid. One of the devices extends the low-frequency limit of amplification; the other shifts high-frequency energy to a lower frequency range. In general, previous evaluations of these special hearing aids have obtained inconsistent or inconclusive results. This paper reviews most of the published research on the use of special hearing aids by deaf children, summarizes several unpublished studies, and suggests a set of guidelines for future evaluations of special and conventional amplification systems.

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