Changes in Turkey Femora Mechanical Properties Resulting From Selective Breeding for Body Weight

Author(s):  
Ziwei Zhong ◽  
Serife Agcaoglu ◽  
Matthew Muckley ◽  
Hansi Zhao ◽  
Darrin Karcher ◽  
...  

Bone plays an integral role in movement and organ protection. To accomplish these tasks successfully, bone must not only be able to withstand daily fatigue loading, but also have a safety margin for unexpected high loads. The two major inputs that determine bone structure are genetics and environmental stresses [1]. Excessive stresses on bone are dissipated through the formation of microcracks [1]. When the remodeling dynamics are altered, problems such as trabecular and cortical thinning, and inadequate microcrack repair may occur, ultimately leading to bone failure [1].

Author(s):  
A. Ajdari ◽  
P. K. Canavan ◽  
H. Nayeb-Hashemi ◽  
G. Warner

Three-dimensional structure of trabecular bone can be modeled by 2D or 3D Voronoi structure. The effect of missing cell walls on the mechanical properties of 2D honeycombs is a first step towards understanding the effect of local bone resorption due to osteoporosis. In patients with osteoporosis, bone mass is lost first by thinning and then by resorption of the trabeculae [1]. Furthermore, creep response is important to analyze in cellular solids when the temperature is high relative to the melting temperature. For trabecular bone, as body temperature (38 °C) is close to the denaturation temperature of collagen (52 °C), trabecular bone creeps [1]. Over the half of the osteoporotic vertebral fractures that occur in the elderly, are the result of the creep and fatigue loading associated with the activities of daily living [2]. The objective of this work is to understand the effect of missing walls and filled cells on elastic-plastic behavior of both regular hexagonal and non-periodic Voronoi structures using finite element analysis. The results show that the missing walls have a significant effect on overall elastic properties of the cellular structure. For both regular hexagonal and Voronoi materials, the yield strength of the structure decreased by more than 60% by introducing 10% missing walls. In contrast, the results indicate that filled cells have much less effect on the mechanical properties of both regular hexagonal and Voronoi materials.


Physiology ◽  
1995 ◽  
Vol 10 (1) ◽  
pp. 30-35 ◽  
Author(s):  
LW Welling ◽  
MT Zupka ◽  
DJ Welling

Basement membranes from renal tubules, capillaries, venules, and pulmonary alveolar wall all have remarkably similar elastic properties and Young's moduli. Strength and safety margin, however, are far smaller in the alveolar wall, perhaps as a result of its complexity of design.


2014 ◽  
Vol 68 (3-4) ◽  
pp. 207-214
Author(s):  
Vladan Djermanovic ◽  
Sreten Mitrovic ◽  
Ruzica Trailovic ◽  
Dragisa Trailovic ◽  
Sergej Ivanov

Balkan donkey is native breed of donkeys evolutively adapted to modest breeding conditions and different climatic systems including harsh and severe climate of Serbian mountains. Unfortunately, the purposes for breeding small donkeys have been lost during the 20th century so the population is regressing. There has been no selective breeding of the autochthonous donkeys in Serbia therefore the data on breed characteristics are recent and few. The monitoring of morphological characteristics of autochthonous Balkan donkey population in Serbia have been performed in aim to characterize the population and to define the importance of autochthonous donkeys as national genetic resource . The morphometric parameters evaluated i.e. height at withers (HWi) body length (BLe), thorax girth (TGi), cannon perimeter (CPe) and body weight (BW) in young Balkan donkeys bred in traditional conditions were used for establishment of the following body indexes: Index of Body Frame (IBF), Index of Body Compactness (BCI), Index of Conformation (CoI) and Dactyl-costal Index (DCI) reflecting body development and conformational relations in Balkan donkey population in Serbia.


Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1501 ◽  
Author(s):  
Soundhar Arumugam ◽  
Jayakrishna Kandasamy ◽  
Ain Umaira Md Shah ◽  
Mohamed Thariq Hameed Sultan ◽  
Syafiqah Nur Azrie Safri ◽  
...  

This study aims to explore the mechanical properties of hybrid glass fiber (GF)/sisal fiber (SF)/chitosan (CTS) composite material for orthopedic long bone plate applications. The GF/SF/CTS hybrid composite possesses a unique sandwich structure and comprises GF/CTS/epoxy as the external layers and SF/CTS/epoxy as the inner layers. The composite plate resembles the human bone structure (spongy internal cancellous matrix and rigid external cortical). The mechanical properties of the prepared hybrid sandwich composites samples were evaluated using tensile, flexural, micro hardness, and compression tests. The scanning electron microscopic (SEM) images were studied to analyze the failure mechanism of these composite samples. Besides, contact angle (CA) and water absorption tests were conducted using the sessile drop method to examine the wettability properties of the SF/CTS/epoxy and GF/SF/CTS/epoxy composites. Additionally, the porosity of the GF/SF/CTS composite scaffold samples were determined by using the ethanol infiltration method. The mechanical test results show that the GF/SF/CTS hybrid composites exhibit the bending strength of 343 MPa, ultimate tensile strength of 146 MPa, and compressive strength of 380 MPa with higher Young’s modulus in the bending tests (21.56 GPa) compared to the tensile (6646 MPa) and compressive modulus (2046 MPa). Wettability study results reveal that the GF/SF/CTS composite scaffolds were hydrophobic (CA = 92.41° ± 1.71°) with less water absorption of 3.436% compared to the SF/CTS composites (6.953%). The SF/CTS composites show a hydrophilic character (CA = 54.28° ± 3.06°). The experimental tests prove that the GF/SF/CTS hybrid composite can be used for orthopedic bone fracture plate applications in future.


Author(s):  
Matthew Muckley ◽  
Serife Agcaoglu ◽  
Ziwei Zhong ◽  
Hansi Zhao ◽  
Morgan Grisham ◽  
...  

Crespo et al. (1999) was the first to identify the problem of turkey femoral fractures in breeding farms [3]. It was suggested that this type of failure was the result of fatigue under daily activities as opposed to acute trauma [1]. There are a number of factors that can lead to decreased bone integrity including ineffective bone mineralization, microcrack propagation and changes in collagen fibril orientation [1, 4, 5].


1964 ◽  
Vol 6 (1) ◽  
pp. 73-84 ◽  
Author(s):  
B. C. Yalçin ◽  
Maurice Bichard

Donald (1962) has recently pointed out the paucity of available data on production from British sheep, though some information is available for hill sheep (see for example Donald, 1958; Purser and Roberts, 1959; Purser and Young, 1959; Dalton, 1962). Most of these refer mainly to the Scottish Blackface and Welsh Mountain breeds. Hill sheep form approximately 40% of the national flock of over 11 million breeding ewes. Another 40% of ewes are found in crossbred flocks mainly kept on the lowlands; these produce fat lambs and hoggets with wool as a secondary product. Very little information has so far been published on these crossbred ewes, exceptions being work reported by Bywater (1945) and Rennie (1957). This is the first of three papers to be presented with the object of providing such information, and is based mainly on the work of Yalçin (1963). It is hoped that these papers will be of use on two counts:1. To provide a documentation of one specific cross, the Border Leicester × Cheviot ewe and her Suffolk-cross lambs under North of England grassland conditions.2. To analyse the usefulness of keeping production records within such flocks as aids to good commercial management, to culling and to selective breeding.In this paper the traits studied are body weight, fleece weight and litter size of the ewes, and the weights of the lambs between birth and slaughter or weaning. Estimates were obtained for the effects upon some of these traits of age and live-weight of ewe, and of sex, year and type of birth and rearing of the lambs. The usefulness of such correction factors is considered within recording schemes. In subsequent papers the effects on production of differences between crossbred ewes and between the rams used as fat lamb sires will be considered.


2011 ◽  
Vol 4 (1) ◽  
pp. 51 ◽  
Author(s):  
M. A. Islam

During earthquake, the ground along with its various natural and manmade structures experiences shaking of various intensities and frequencies depending on the nature of the earthquake. The loading activities caused by earthquakes on various structures are very much cyclic type, which is popularly known as fatigue loading. On the other hand, for modern high-rise buildings a large volume of steel bar is used to reinforce the concrete because of the pioneer role of steel bars embedded inside the concrete for safety of the buildings. In this study various mechanical properties of reinforcing steel bars that are essential to counter balance the earthquake effects have been identified first. At the same time these essential mechanical properties have been defined and studied for most commonly used reinforcing steel bars. For doing this, both the conventional and advanced structural steels were selected. The mechanical properties and fatigue behaviours of these steels have been presented and discussed in this paper.  Keywords: Earthquake; High-rise buildings; Reinforcing steel bars; Conventional structural steel; Advanced structural steel.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.7069 J. Sci. Res. 4 (1), 51-63 (2012)


Sign in / Sign up

Export Citation Format

Share Document