Differences in egg size, shell thickness, pore density, pore diameter and water vapour conductance between first and second eggs of Snares Penguins Eudyptes robustus and their influence on hatching asynchrony

Ibis ◽  
2005 ◽  
Vol 147 (2) ◽  
pp. 251-258 ◽  
Author(s):  
MELANIE MASSARO ◽  
LLOYD S. DAVIS
Keyword(s):  
Water Vapour ◽  
Shell Thickness ◽  
Egg Size ◽  
Pore Diameter ◽  
Hatching Asynchrony ◽  
Pore Density

scholarly journals Influence of the anodization conditions and chemical treatment on the formation of alumina membranes with defined pore diameters

2021 ◽  
Author(s):  
Iwona Dobosz
Keyword(s):  
Aluminum Oxide ◽  
Chemical Treatment ◽  
Anodic Aluminum Oxide ◽  
Pore Diameter ◽  
Operating Conditions ◽  
Oxide Growth ◽  
Pore Density ◽  
Anodic Aluminum ◽  
Pore Widening ◽  
Oxide Membranes

AbstractPorous anodic aluminum oxide membranes were fabricated via two-step anodization of aluminum in 0.3 M H2C2O4, 0.3 M H2SO4 and 0.17 M H3PO4 solutions. The parameters of the oxide film such as: pore diameter (Dp), interpore distance (Dc), porosity (P) and pore density (ρ) can be completely controlled by the operating conditions of the anodization. Additionally, the pore diameters and pore density can be controlled via a chemical treatment (pore opening/widening process). The effect of anodizing conditions such as the applied voltage, type of electrolyte and purity of the substrate on the rate of porous oxide growth are discussed. The obtained results were compared with the theoretical predictions and data that has been reported in the literature. The influence of the duration of chemical etching on the structural features of the oxide membranes was studied. On the based on qualitative and quantitative FFT analyzes and circularity maps, it was found that the nanostructures of anodized aluminum have the maximum order under certain specified conditions. The presence of alloying elements affects not only the rate of oxide growth but also the morphology of the anodic aluminum oxide. The rate of oxide growth depends on the electrolyte type and temperature. During chemical treatment of the oxide films pore diameter increases with the pore widening time and the highest pore widening was observed in phosphoric acid solution.

Constraints on Hatching Asynchrony and Egg Size in Pied Flycatchers

10.2307/5127 ◽  
1989 ◽  
Vol 58 (3) ◽  
pp. 837 ◽  
Author(s):  
Tore Slagsvold ◽  
Jan T. Lifjeld
Keyword(s):  
Egg Size ◽  
Hatching Asynchrony

Variation in Peregrine Falcon Eggs

The Auk ◽  
1984 ◽  
Vol 101 (3) ◽  
pp. 578-583 ◽  
Author(s):  
William A. Burnham ◽  
James H. Enderson ◽  
Thomas J. Boardman
Keyword(s):  
Embryonic Development ◽  
Representative Sample ◽  
Shell Thickness ◽  
Egg Size ◽  
Peregrine Falcon ◽  
Eggshell Thickness ◽  
Fresh Weight ◽  
Initial Weight ◽  
Future Studies ◽  
Peregrine Falcons

Abstract Eggs collected from captive and wild Peregrine Falcons (Falco peregrinus) were used to examine variation in eggshell thickness, length, breadth, and initial weight to resolve questions about eggshell data from wild falcons. For captive falcons, shell thickness of first clutches did not change over the years a falcon laid or with embryonic development. Eggshells in third clutches, but not second clutches, were significantly thinner than those from first clutches. Greatest variation in shell thickness existed between eggs within a clutch and did not differ significantly between wild and captive eggs. Entire clutches of wild falcons should be represented in future studies to maximize the chance of obtaining a representative sample in regard to shell thickness. Egg size (L, B, and fresh weight) decreased over the years a captive falcon laid. A significant decrease in size (B and fresh weight) also occurred in second and third clutches laid the same year. Ratcliffe's Index generally appeared to be a reliable indicator of shell thickness in captive-laid eggs.

scholarly journals Influence of Dry Rum Distillery Slops in Diets for White Leghorn Hens on Laying Rate, Feed Conversion, and Egg Size and Quality

1969 ◽  
Vol 61 (4) ◽  
pp. 465-469
Author(s):  
Manuel Soldevila ◽  
Renato Irizarry
Keyword(s):  
Calcium Metabolism ◽  
Shell Thickness ◽  
Egg Size ◽  
Feed Utilization ◽  
Shell Formation ◽  
White Leghorn ◽  
Feed Conversion ◽  
Egg Weight ◽  
Cane Molasses ◽  
Isocaloric Diets

Balanced (isonitrogenous and isocaloric) diets containing from 0 to 35% dried cane molasses rum distillery slops were compared using individually caged White Leghorn hens of the Kimber strain. When production and feed utilization were compared, a stepwise decrease, more pronounced with levels above 20%, was evident with increases in the slops content of the diets. Eggs were permanently stained and hens markedly soiled when consuming diets with levels of dry slops higher than 15%. Averages of egg weight, hen weight, broken-open egg height (inner quality), and shell thickness were not affected by levels of dry slops as high as 35% in the diets. The high levels of K, Mg, and SO4  present in the experimental diets did not affect the calcium metabolism involved in shell formation.

scholarly journals Study on Crack Development and Micro-Pore Mechanism of Expansive Soil Improved by Coal Gangue under Drying–Wetting Cycles

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6546
Author(s):  
Hongxing Zhu ◽  
Yan Zhang ◽  
Zhuhan Li ◽  
Xiaoyu Xue
Keyword(s):  
Soil Sample ◽  
Pore Volume ◽  
Pore Diameter ◽  
Expansive Soil ◽  
Soil Samples ◽  
Coal Gangue ◽  
Pore Density ◽  
Pore Characteristics ◽  
Average Pore ◽  
Road Engineering

Expansive soil is prone to cracks under a drying–wetting cycle environment, which brings many disasters to road engineering. The main purpose of this study is use coal gangue powder to improve expansive soil, in order to reduce its cracks and further explore its micro-pore mechanism. The drying–wetting cycles test is carried out on the soil sample, and the crack parameters of the soil sample are obtained by Matlab and Image J software. The roughness and micro-pore characteristics of the soil samples are revealed by means of the Laser confocal 3D microscope and Mercury intrusion meter. The results show that coal gangue powder reduces the crack area ratio of expansive soil by 48.9%, and the crack initiation time is delayed by at least 60 min. Coal gangue powder can increase the internal roughness of expansive soil. The greater the roughness of the soil, the less cracks in the soil. After six drying–wetting cycles, the porosity and average pore diameter of the improved and expanded soil are reduced by 37% and 30%, respectively, as compared to the plain expansive soil. By analyzing the cumulative pore volume and cumulative pore density parameters of soil samples, it is found that the macro-cracks are caused by the continuous connection and fusion of micro-voids in soil. Coal gangue powder can significantly reduce the proportion of micro-voids, cumulative pore volume, and cumulative pore density in expansive soil, so as to reduce the macro-cracks.

Fabrication of Low Cost Membrane from Anodic Aluminum Oxide

2017 ◽  
Vol 751 ◽  
pp. 363-367
Author(s):  
Peerawith Sumtong ◽  
Apiluck Eiad-Ua
Keyword(s):  
Aluminum Oxide ◽  
Anodic Aluminum Oxide ◽  
Pore Diameter ◽  
Average Pore Diameter ◽  
Process Conditions ◽  
Low Grade ◽  
Pore Density ◽  
Average Pore ◽  
Anodic Aluminum ◽  
Interpore Distance

Anodic Aluminum Oxide (AAO) membrane has been successfully fabricated from two-step anodization with aluminum low grade (Al6061). The pore density, the pore diameter, and the interpore distance can be controlled by varying anodization process conditions. However, there are limits to control the mechanical strength and growth of AAO arrays, such as pore density, pore diameter and interpore distance. In this research the self-organized two-step anodization is carried out varying time at 24, 48 and 72 hours, respectively with 40V at the low temperature 2-5°C. The optimum conditions of AAO with two-step anodization is 40V for 48 hr. Finally, AAO substrate is separated from aluminum low-grade and enlarged pore diameter with pore widening process by 5% H3PO4. The physical properties were investigated by mean of field emission scanning electron microscope (FE-SEM) show that the average pore diameter and average interpore distance increase with the anodization time. Al6061 Aluminum substrate can be used to fabricate a nanoporous AAO film with an average pore diameter and average interpore distance larger than 70 and 90 nanometers, respectively but less mechanical stability.

Sign in / Sign up

Export Citation Format

Share Document