Nonlinear analysis of laminated fibrous composites

A computerized analysis of the nonlinear behavior of fibrous composite laminates including axial loading, thermal loading, temperature dependent properties, and edge effects is presented. Ramberg-Osgood approximations are used to represent lamina stress-strain behavior and percent retention curves are employed to model the variation of properties with temperature. Balanced, symmetric laminates comprised of either boron/epoxy, graphite/epoxy, or borsic-aluminum are analyzed using a quasi-three-dimensional finite element analysis. Results are presented for the interlaminar stress distributions in cross-ply, angle-ply, and more complex laminates. Nonlinear stress-strain curves for a variety of composite laminates in tension and compression are obtained and compared to other existing theories and experimental results

Rate and time dependent behavior of structural adhesives

Studies on two adhesives (Metlbond 1113 and 1113-2) identified as having applications in the bonding of composite materials are presented. Constitutive equations capable of describing changes in material behavior with strain rate are derived from various theoretical approaches. It is shown that certain unique relationships exist between these approaches. It is also shown that the constitutive equation derived from mechanical models can be used for creep and relaxation loading. A creep to failure phenomenon is shown to exist and is correlated with a delayed yield equation proposed by Crochet. Loading-unloading results are presented and are shown to correlate well with the proposed form of the loading-unloading equations for the modified Bingham model. Experimental results obtained for relaxation tests above and below the glass transition temperature are presented. It is shown that the adhesives obey the time-temperature superposition principle

llama meat nutritional properties

The aim of this study was to determine the chemical composition of the muscle Longissimus thoracis taken from 20 llama males, reared in the Andean region, slaughtered at an age of 25 months and at a mean final body weight of 74kg. Llama meat showed a low fat (3.51%) and cholesterol content (58.16mg/100g), a good protein content (22.42%) and an ash content of 3.06%. The Warner-Bratzler shear force values determined in llama meat was 6.56 kg/cm2. This study confirmed that llama meat is healthy and nutritious, and represents a good source of proteins for Andean population

Wool quality in Gentile di Puglia sheep breed as measure of genetic integrity

The Gentile di Pugliais a breed created in the 15th century by crossing Merino Spanish rams and "gentile" ewes reared in some areas of Southern Italy, mainly Apulia and Basilicata. The crisis of the wool industry, the poor quantity of milk, the inadequacy of Gentile di Pugliato be milked by machine and the passage from transhumant to permanent rearing caused a dramatic reduction of this population, which was largely crossed with other breeds and declined from about one million heads in the sixties to 5,000 at the present time. In order to save the ancient typical Gentile di Pugliabreed, the aim of this work was to estimate the "genetic integrity" of the remaining Gentile di Pugliapopulation by means of an analysis of wool quality measured through the diameter of the fibre and the homogeneity of the fleece. Our hypothesis was that the animals originated from outcrosses to other Merino derived breeds specialised for meat would show larger diameters of the fibres and a reduced homogeneity of the fleece. The research was carried out using Herd Book registered animals from 9 farms: 1 from Isernia, 2 from Campobasso and 6 from Foggia province. The statistical analysis on the diameter of the fibre was carried out on a dataset of 38,200 observations (200 records x 191 animals) divided in four classes (ultrafine, fine, croisè, ordinary). The high frequencies of ultrafine and fine fibre classes show that the quality of the wool is still good in the population. This consideration can be extended to all the farms involved in the study that could therefore be suitable in the conservation programs for this breed. The homogeneity of the fleece was also good in provid- ing further evidence of the genetic integrity of the population. Other analysis carried out on the quality of the wool in relation to the body size confirmed that the observed Gentile di Pugliais well representative of the ancient breed

Interaction between ASIP and MC1R in Black and Brown Alpaca

Animal fibres from South American camelids and other fibre or wool bearing species provide important products for use by the human population. The contemporary context includes the competition with petrocarbon-based artificial fibres and concern about excessive persistence of these in the natural environment. Animal fibres present highly valuable characteristics for sustainable production and processing as they are both natural and renewable. On the other hand, their use is recognised to depend on availability of appropriate quality and quantity, the production of which is underpinned by a range of sciences and processes which support development to meet market requirements. This collection of papers combines international experience from South and North America, China and Europe. The focus lies on domestic South American camelids (alpacas, llamas) and also includes research on sheep and goats. It considers latest advances in sustainable development under climate change, breeding and genetics, reproduction and pathology, nutrition, meat and fibre production and fibre metrology. Publication of this book is supported by the Animal Fibre Working Group of the European Federation of Animal Science (EAAP). ‘Advances in Fibre Production Science in South American Camelids and other Fibre Animals’ addresses issues of importance to scientists and animal breeders, textile processors and manufacturers, specialised governmental policy makers and students studying veterinary, animal and applied biological sciences

Interaction of ASP and MC1R in black and brown alpaca.

Alpaca coat colour is a relevant feature both for breeders than textile industries. Agouti (ASP) and Extension (MC1R) are genes known to be involved in coat colour through pigmentation pathways by regulating type, amount and distribution of eumelanin and pheomelanin pigments in melanocytes. In alpaca genotype of ASP and MC1R genes have already been analysed distinctly, but their epistatic interaction have not been evaluated. In this study have been assessed their segregation more insights on black and brown phenotypes. In several mammals MC1R is epistatic over ASP, id est recessive allele in Agouti (a) and dominant allele in Extension locus (E) produces black phenotype. That is confirmed in alpaca where black coat has aH/aΔ57 and aH/ahT genotype on agouti and E/E or E/e genotype on MC1R locus. Otherwise ASP and MC1R in Brown/Red Brown, have a dominant profile at least in one allele as A/A, A/ahT on Agouti and E/e on Extension. Genotype and phenotype comparison clears that receptor and ligand are in concordance to produce pheomelanin and eumelanin in alpaca. Segregation analysis of 12 alpaca families genotyped by coat color, confirm the dominance of brown over black and could be helpful for coat colour classification and genotyping

Preliminary study on MC1R polymorphism in some cattle breeds raised in Italy

Ricerche preliminari sul polimorfismo del gene MC1R in alcune razze bovine allevate in Italia – Il gene MC1R è stato analizzato in 193 soggetti appartenenti a 8 razze bovine, tramite PCR, per la presenza di due mutazioni ad effetto fenotipico noto sulla pigmentazione del mantello: la delezione G310 e la sostituzione T296C, associate rispettivamente al fenotipo feomelanico (e) ed eumelanico nero (Ed). Sessanta soggetti di razza Limousine e Pezzata Rossa Italiana presentano genotipo e/e; 27 soggetti di razza Frisona Italiana mostrano genotipo Ed/Ed mentre 2 genotipo Ed/e. Gli 84 soggetti appartenenti alle razze Cabannina, Chianina, Marchigiana e Piemontese non presentano tali mutazioni, analogamente a 18 soggetti di razza Romagnola, nella quale però si sono anche osservati 2 soggetti portatori dell’allele e allo stato eterozigote

Non-genetic factors affecting hunting ability in italian maremma scent hound

This study aimed to evaluate the effect of four non-genetic factors (sex, coat colour, competition judges, type of trial) on the five hunting traits (search, approach, tracking of prey, standstill barking and physical skills) used to estimate the aptitude for wild boar hunt in Italian Maremma Scent Hound. A total of 1147 dogs (734 males, 399 females, and 14 not sexed dogs) were evaluated in competitions held in North-Central Italy, from 2010 to 2011. Dogs were tested as individuals, pairs and packs. Coat colour had no effect on the five tested traits. A significant difference (p<0.01) between males and females was observed only for search. Type of trial had a significant effect (p<0.01) on all the five hunting traits. Judges factor was significant (p<0.01) for physical skills and barking remaining firm in place. A significant positive phenotypic correlation was observed among tracking of prey, approach and physical skills (p<0.01). Approach and physical skills were positively correlated with approach (p<0.05) and tracking of prey (p<0.01). Search was negatively correlated with all the other four, whereas standstill barking showed no correlation with any traits. These data are the basis to improve our knowledge about the values of variability in considered hunting traits and they provide genetic criteria to the breeders to achieve more stringent selective choices

Variability of fibre quality on Chinese Alashan Left Banner White Cashmere goat

The heritability and the phenotypic and genetic correlations of down weight (DW), down fibre diameter (DFD), and coefficient of variation of the down fibre diameter (CVDFD) of Chinese Alashan Left Banner White Cashmere goat were estimated on 1375 one-year-old animals, born in 2009, 2011 and 2013 and bred at the Station for Livestock Improvement of Alashan (Left Banner, Inner Mongolia, P.R. China). For all traits, significant effects were for sex, cohort and sex–cohort interaction (p <.001). The heritability for DFD and CVDFD was high, 0.41 ± 0.08 and 0.52 ± 0.06, respectively. Heritability for the DW was low (0.12 ± 0.03). Phenotypic correlation calculated by Pearson’s coefficient showed that DFD is positively correlated with both CVDFD (0.29 ± 0.07) and DW (0.20 ± 0.05). The phenotypic correlation between CVDFD and DW was negative (−0.11 ± 0.06). The genetic correlations between DW and CVDFD and between DFD and CVDFD were both high and positive (0.63 ± 0.16 and 0.39 ± 0.1, respectively) while the DW showed a negative genetic correlation with DFD (−0.27 ± 0.2). Our results suggest that the selection for reducing DFD and its CVDFD is possible and a genetic progress can be achieved quickly in the Chinese Alashan Left Banner White Cashmere goat

Alpaca FGF5: Hypothetical Post-Transcriptional Readthrough Regulation in Skin Biopsies

Animal fibres from South American camelids and other fibre or wool bearing species provide important products for use by the human population. The contemporary context includes the competition with petrocarbon-based artificial fibres and concern about excessive persistence of these in the natural environment. Animal fibres present highly valuable characteristics for sustainable production and processing as they are both natural and renewable. On the other hand, their use is recognised to depend on availability of appropriate quality and quantity, the production of which is underpinned by a range of sciences and processes which support development to meet market requirements. This collection of papers combines international experience from South and North America, China and Europe. The focus lies on domestic South American camelids (alpacas, llamas) and also includes research on sheep and goats. It considers latest advances in sustainable development under climate change, breeding and genetics, reproduction and pathology, nutrition, meat and fibre production and fibre metrology. Publication of this book is supported by the Animal Fibre Working Group of the European Federation of Animal Science (EAAP). ‘Advances in Fibre Production Science in South American Camelids and other Fibre Animals’ addresses issues of importance to scientists and animal breeders, textile processors and manufacturers, specialised governmental policy makers and students studying veterinary, animal and applied biological sciences