scholarly journals Surface Wetting and Its Effect on Body and Surface Temperatures of Domestic Laying Hens at Different Thermal Conditions

2008 ◽  
Vol 87 (12) ◽  
pp. 2441-2450 ◽  
Author(s):  
S. Mutaf ◽  
N. Şeber Kahraman ◽  
M.Z. Fırat
Keyword(s):  
Laying Hens ◽  
Thermal Conditions ◽  
Surface Wetting ◽  
Surface Temperatures

Using Thermoelectric Cooling With Tourniquets for Nerve Preservation

2016 ◽  
Author(s):  
M. Trupiano ◽  
S. Aarabi ◽  
A. F. Emery
Keyword(s):  
Thermal Conditions ◽  
Ambient Conditions ◽  
Transfer Coefficients ◽  
Thermoelectric Coolers ◽  
Ambient Temperatures ◽  
Nerve Preservation ◽  
Heat Transfer Coefficients ◽  
Surface Temperatures ◽  
Element Simulation ◽  
Free And Forced Convection

The use of a tourniquet leads to nerve damage, even if applied for short periods of time. This damage can be minimized if the limb is cooled. Because of the low conductivities of human tissue, core limb cooling is slow unless the surface temperature is very cool. Subzero surface temperatures can lead to skin injury (i.e., frostbite). Ideally one would adjust the limb surface temperatures as a function of time to maximize the cooling rate while avoiding permanent tissue damage. One possible approach is to use a thermoelectric cooler (TEC) in conjunction with a programmable power supply. TEC performance varies strongly with heat absorption rate, a function of limb thermal properties, and hot side temperatures that are strongly affected by the surface conditions on the hot side, i.e., overall heat transfer coefficients and ambient conditions. The paper describes the use of finite element simulation to predict the usefulness of using thermoelectric coolers applied to the surface of a limb when compared to the standard approach of using ice packs. Since the TEC performance is strongly influenced by its warm side thermal conditions, experimental results are presented for different ambient temperatures, free and forced convection, and evaporation of water from a wickable covering.

scholarly journals Changes in facial surface temperature of laying hens under different thermal conditions

2020 ◽  
Author(s):  
Na Yeon Kim ◽  
Seong Jin Kim ◽  
Mirae Oh ◽  
Se Young Jang ◽  
Sang Ho Moon
Keyword(s):  
Surface Temperature ◽  
Laying Hens ◽  
Thermal Conditions

scholarly journals Analysis of Cluster and Unrest Behaviors of Laying Hens Housed under Different Thermal Conditions and Light Wave Length

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 2017
Author(s):  
Aline Mirella Fernandes ◽  
Diogo de Lucca Sartori ◽  
Flávio José de Oliveira Morais ◽  
Douglas D’Alessandro Salgado ◽  
Danilo Florentino Pereira
Keyword(s):  
Laying Hens ◽  
Thermal Environment ◽  
Light Wave ◽  
Wave Length ◽  
Red Light ◽  
Thermal Conditions ◽  
Behavioral Changes ◽  
Small Scale ◽  
Analysis Of The Images ◽  
Cluster Behavior

Laying hens are affected by the intensity, wavelength, and duration of light, and the behavioral patterns of these animals are important indicators of stress. The objective of the present study was to evaluate cluster and unrest behaviors of lying hens submitted to three environments with different treatments of monochromatic lighting (blue, green, and red). For 29 weeks, 60 laying hens from the Lohmann variety were divided into three groups and monitored by surveillance cameras installed on each shed ceiling and directed to the floor. Each group was housed in a small-scale shed and maintained under a monochromatic lighting treatment. The recordings were made at two times of the day, 15 min in the morning and 15 min in the afternoon, and the videos were processed, segmented, and analyzed computationally. From the analysis of the images, the cluster and unrest indexes were calculated. The results showed the influence of lighting on these behaviors, displaying that the birds were more agitated in the treatments with shorter wavelengths. Cluster behavior was higher in birds housed under red light. There was an interaction between the lighting treatments and the thermal environment, indicating that more studies should be carried out in this area to better understand these behavioral changes.

scholarly journals Spatial behavior of the thermo-luminous conditions of facility laying hens in naturally ventilated vertical system

2018 ◽  
Vol 42 (5) ◽  
pp. 550-560
Author(s):  
Letícia Cibele da Silva Ramos Freitas ◽  
Ilda de Fátima Ferreira Tinôco ◽  
Richard Stephen Gates ◽  
Cecília de Fátima Souza ◽  
Matteo barbari ◽  
...  
Keyword(s):  
Decision Making ◽  
Relative Humidity ◽  
Light Intensity ◽  
Laying Hens ◽  
Thermal Conditions ◽  
Longitudinal Direction ◽  
Spatial Behavior ◽  
Intensity Data ◽  
Lower Light ◽  
Vertical System

ABSTRACT The facilities for laying hens should be designed to provide thermal comfort and satisfactory luminosity for the production of quality eggs. The objective of this study was to evaluate the spatial behavior of thermal conditions and light intensity of facilities for laying hens with vertical cages naturally conditioned during winter and summer. Air temperature, air relative humidity and light intensity data were collected in 75 points distributed evenly through the longitudinal direction of the installation in three tiers of cages (first, third and sixth). Each point represented a set of coordinates (x, y, z), being the x-axis the lines (L1, L2, L3, L4, L5), y-axis the sections (S1, S2, S3, S4, S5) and z-axis the tiers (N1, N2, N3). The spatial behavior of the thermal conditions of the facility was held during the coldest period of winter and the warmest period of summer. The experimental design was completely randomized in a factorial scheme. In the winter, the temperature showed homogeneous behavior among sections and variable among lines. In the summer, the spatial variability of temperature and humidity was more accentuated than in the winter, mainly among tiers. For both seasons, the center of the facility presented lower light intensity than the lateral. From the spatial behavior of the thermal conditions of the facility laying hens, it is possible to verify the magnitude and variability of temperature, relative humidity and light intensity, identify vulnerable and deficit thermal regions and contribute to decision-making related to thermal conditioning and luminosity of the facility.

OPTIMIZATION OF PARTIAL SURFACE WETTING TO COOL CAGED LAYING HENS

2002 ◽  
Vol 45 (4) ◽  
Author(s):  
T. Yanagi ◽  
Jr. ◽  
H. Xin ◽  
R. S. Gates
Keyword(s):  
Laying Hens ◽  
Surface Wetting

scholarly journals Changes in facial surface temperature of laying hens under different thermal conditions

2020 ◽  
Author(s):  
Na Yeon Kim ◽  
Seong Jin Kim ◽  
Mirae Oh ◽  
Se Young Jang ◽  
Sang Ho Moon
Keyword(s):  
Surface Temperature ◽  
Laying Hens ◽  
Thermal Conditions

Effect of Vitamin D3 on Cadmium Retention by Laying Hens

2002 ◽  
Vol 52 (2) ◽  
pp. 81-84
Author(s):  
B. Koréneková ◽  
A. Jacková ◽  
J. Kottferová ◽  
P. Siklenka ◽  
M. Skalická ◽  
...  
Keyword(s):  
Vitamin D ◽  
Laying Hens

Numerical simulation of the tree higro-thermal response in forest fire environment

2020 ◽  
pp. 57-65
Author(s):  
Eusébio Conceiçã ◽  
João Gomes ◽  
Maria Manuela Lúcio ◽  
Jorge Raposo ◽  
Domingos Xavier Viegas ◽  
...  
Keyword(s):  
Forest Fire ◽  
Numerical Study ◽  
Thermal Response ◽  
View Factor ◽  
Tree Model ◽  
Pine Tree ◽  
Surface Temperatures ◽  
Fire Environment ◽  
Fire Front ◽  
Heat Exchanges

This paper refers to a numerical study of the hypo-thermal behaviour of a pine tree in a forest fire environment. The pine tree thermal response numerical model is based on energy balance integral equations for the tree elements and mass balance integral equation for the water in the tree. The simulation performed considers the heat conduction through the tree elements, heat exchanges by convection between the external tree surfaces and the environment, heat exchanges by radiation between the flame and the external tree surfaces and water heat loss by evaporation from the tree to the environment. The virtual three-dimensional tree model has a height of 7.5 m and is constituted by 8863 cylindrical elements representative of its trunks, branches and leaves. The fire front has 10 m long and a 2 m high. The study was conducted taking into account that the pine tree is located 5, 10 or 15 m from the fire front. For these three analyzed distances, the numerical results obtained regarding to the distribution of the view factors, mean radiant temperature and surface temperatures of the pine tree are presented. As main conclusion, it can be stated that the values of the view factor, MRT and surface temperatures of the pine tree decrease with increasing distance from the pine tree in front of fire.

Application of pyrometer and standard sample to determine surface temperature of studied materials

2019 ◽  
pp. 9-13
Author(s):  
V.Ya. Mendeleyev ◽  
V.A. Petrov ◽  
A.V. Yashin ◽  
A.I. Vangonen ◽  
O.K. Taganov
Keyword(s):  
Composite Material ◽  
Surface Temperature ◽  
Relative Error ◽  
Wavelength Range ◽  
Standard Sample ◽  
A Priori ◽  
Temperature Changes ◽  
Surface Temperatures ◽  
Relative Errors ◽  
Normal Emissivity

Determining the surface temperature of materials with unknown emissivity is studied. A method for determining the surface temperature using a standard sample of average spectral normal emissivity in the wavelength range of 1,65–1,80 μm and an industrially produced Metis M322 pyrometer operating in the same wavelength range. The surface temperature of studied samples of the composite material and platinum was determined experimentally from the temperature of a standard sample located on the studied surfaces. The relative error in determining the surface temperature of the studied materials, introduced by the proposed method, was calculated taking into account the temperatures of the platinum and the composite material, determined from the temperature of the standard sample located on the studied surfaces, and from the temperature of the studied surfaces in the absence of the standard sample. The relative errors thus obtained did not exceed 1,7 % for the composite material and 0,5% for the platinum at surface temperatures of about 973 K. It was also found that: the inaccuracy of a priori data on the emissivity of the standard sample in the range (–0,01; 0,01) relative to the average emissivity increases the relative error in determining the temperature of the composite material by 0,68 %, and the installation of a standard sample on the studied materials leads to temperature changes on the periphery of the surface not exceeding 0,47 % for composite material and 0,05 % for platinum.

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