Poro-viscoelastic materials are well modelled with Biot-Allard equations. This model needs a number of geometrical parameters in order to describe the macroscopic geometry of the material and elastic parameters in order to describe the elastic properties of the material skeleton. Several characterisation methods of viscoelastic parameters of porous materials are studied in this thesis. Firstly, quasistatic and resonant characterization methods are described and analyzed. Secondly, a new inverse dynamic characterization of the same modulus is developed. The latter involves a two layers metal-porous beam, which is excited at the center. The input mobility is measured. The set-up is simplified compared to previous methods. The parameters are obtained via an inversion procedure based on the minimisation of the cost function comparing the measured and calculated frequency response functions (FRF). The calculation is done with a general laminate model. A parametric study identifies the optimal beam dimensions for maximum sensitivity of the inversion model. The advantage of using a code which is not taking into account fluid-structure interactions is the low computation time. For most materials, the effect of this interaction on the elastic properties is negligible. Several materials are tested to demonstrate the performance of the method compared to the classical quasi-static approaches, and set its limitations and range of validity. Finally, conclusions about their utilisation are given.

Modern cosmological theory is based on the Friedmann-Robertson-Walker (FRW) metric. Often written in terms of co-moving coordinates, this well-known solution to Einstein's equations owes its elegant and highly practical formulation to the Cosmological principal and Weyl's postulate, upon which it is founded. But there is physics behind such symmetries, and not all of it has yet been recognized. In this paper, we derive the FRW metric coefficients from the general form of the spherically-symmetric line element, and demonstrate that, because the co-moving frame also happens to be in free fall, the symmetries in FRW are valid only for a medium with zero active mass. In other words, the spacetime of a perfect fluid in cosmology may be correctly written as FRW only when its equation-of-state is $\rho+3p=0$, in terms of the {\it total} pressure $p$ and {\it total} energy density $\rho$. There is now compelling observational support for this conclusion, including the Alcock-Paczy\'nski test, which shows that only an FRW cosmology with zero active mass is consistent with the latest model-independent Baryon Acoustic Oscillation data.

ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / The measurement result is complete only if it contains the measurand and its units, uncertainty and coverage factor. The uncertainty estimation for the parameters acquired by the FTI is a known process. To execute this task the Institute of Research and Flight Test (IPEV) developed the SALEV© system which is fully compliant with the applicable standards. But the measurement set also includes Derived Parameters. The uncertainty evaluation of these parameters can be solved by cumbersome partial derivates. The search for a simpler solution leads us to a Monte-Carlo based algorithm. The result of using this approach are presented and discussed.

No description available.

No description available.

No description available.

No description available.

Genetic variation between individuals is of great importance for the development of breeding programmes, to select for animals with the most favourable traits. Many production companies routinely measure the feed intake of their animals, in order to calculate efficiency traits such as feed conversion ratio. The development of electronic feeders which automatically record individual intake on a visit-by-visit basis now allows the short-term feeding behaviour of animals to be monitored and analysed as another source of variation between individuals. Due to differences in the resolutions of these feeders as a measurement tool, a standard unit of feeding event needs to be estimated to allow for comparisons between studies. Different models for estimation of the defining value of a meal, the meal criterion, have been used, with the most recent incorporating the change in satiety with time since last feeding as part of the model. In this study I developed a new methodology, based on these models, for use when a within meal population of intervals cannot be easily modelled. I then used this model for application to data from four lines of broiler chickens to estimate meal criteria and compare feeding behaviour within and between the lines. Significant differences were found between fast and slow growing birds, with the faster growing birds having fewer but larger meals than the slower growing birds. However, the lines showed similar structure and bouting of their feeding behaviour, indicating that the fundamental controls of feeding behaviour, such as hunger and satiety, in these lines had been unaltered despite intensive selection for growth. The models were also applied across poultry species, kept in different experimental conditions. A similar structure to the feeding behaviour was found across all these species, with all showing clear separation of feeding events into bouts. In order to estimate the potential use of these behavioural observations in a breeding programme, the heritabilities and genetic correlations with existing performance traits were calculated for the four broiler lines. Heritabilities of all feeding behaviour traits were found to be moderate to high, and very similar across the lines. Correlations with performance traits, however, were low, meaning that there were no clear links of the traits with the current production goals investigated. This indicates that past selection for production has had limited impact on feeding behaviour and also that potential selection for feeding behaviour will have little effect on production gains. To identify the areas of the genome controlling feeding behaviour, traits were associated with a SNP panel. Many regions were found to have highly significant association with feeding behaviour traits, with the most highly correlated traits showing associations with the same regions, suggesting pleiotropic effects of genes in these regions. Future work in this area should include identification of individual genes controlling feeding behaviour to allow prediction of the effects of selection for favourable feeding behaviour on other traits, and comparison of the genotypes of different lines of broilers, to further understand the control of feeding behaviour.

The effect of chemical parameters on cheese structure and functionality was studied by modifying the calcium, salt content, and pH of cheese. Cheese blocks were high-pressure injected from zero to five times with water, solutions of different salts, or an acid solution 14 d after manufacture. Successive injections were performed 24 h apart. After 40-42 d of refrigerated storage, cheese structure was studied by using scanning electron microscopy and digital image analysis, and cheese functionality was characterized by texture profile analysis and melting test. Increased salt content of cheese (2.7 versus 0.1%) caused the protein matrix to become more hydrated and to expand (P < 0.1 ), though the occurrence of syneresis resulted in decreased moisture content of cheese (P < 0.05). Salt injection increased cheese hardness and the initial rate of cheese flow, but it decreased cheese cohesiveness (P < 0.05). Increased calcium content (1.8 versus 0.3%) and decreased pH of cheese (4.7 versus 5.3) caused contraction of the protein matrix (P < 0.05) and release of serum. Thus, the matrix became less hydrated, and the moisture content and weight of cheese decreased (P < 0.05). Calcium injection decreased the pH and melting of cheese, but it increased cheese hardness (P < 0.05). Acid injection promoted calcium solubilization and decreased calcium content of cheese (P < 0.05). Above pH 5.0 (5.0-5.3), acid injection decreased cheese hardness and increased the initial rate of cheese flow (P < 0.05). Below pH 5.0 (5.0-4.7), acid injection decreased cheese cohesiveness, and the initial rate and extent of cheese flow (P < 0.05). In conclusion, modifying the chemical composition of cheese alters protein interactions, resulting in cheese with different structural and functional properties. Increased salt content of cheese (up to 2.7%) impairs protein-to-protein interactions, and its effect is most significant when salt content increases from 0 to 0.5%. Below 5.0 (5.0- 4.7), the effect of pH predominates over calcium content, and decreased cheese pH promotes protein-to-protein interactions. Increased calcium content of cheese (up to 1.8%) also promotes protein-to-protein interactions, and the content of protein-bound calcium may be the major factor controlling the functionality of most cheeses.

The demand for functional foods is on the rise. These are food products that, besides providing energy and nutrients for life, provide additional health benefits. Xylitol, a five-carbon sugar alcohol, is a possible functional food, as well as a sugar replacement. The cost of xylitol has led manufacturers to add inulin, a nondigestible oligosaccharide, as an extender. Both xylitol and inulin have been suggested to provide added health benefits beyond being a reduced calorie replacement for sugar. We tested their impact on several human health parameters (fecal weight, fecal pH, fecal% Ill moisture, blood lipids, blood glucose, and fecal micro flora) with two age groups, "older" (62.3 ± 9.63 y, n= 17) and "younger" (23.3 ± 2.02 y, n= 18). Participants were given two different treatments: A, 7.5 g xylitol and B, 7.5 g of xylitol in combination with 7.5 g of inulin. Treatment schedules were as follows: 2 weeks with one treatment, followed by a 2-week washout period, and 2 weeks with the treatment they had not previously taken. Comparisons were then made between each treatment and the washout period. Due to the low number of participants, we were unable to obtain substantial significance on most observations, but important trends were detected. Treatment with xylitol by itself caused a decrease in stool mass compared to washout (control) values, while the addition of inulin reversed the decrease. This effect is important, as an increased stool mass is associated with a healthy gastrointestinal (GI) tract. Xylitol by itself or with added inulin provided for a more acidic colonic environment, which aids in mineral absorption and inhibition of pathogenic microbes. Both treatments were also noted to cause an increase the frequency of bowel movements compared to washout. As sugar replacements, it was observed that both treatments were associated with a decreased post-prandial blood sugar level from washout, indicating a benefit in blood glucose control. As for blood lipid values, xylitol caused a decrease, compared to washout, in triglycerides and VLDL levels while increasing HDL levels. However, the addition of inulin increased, from washout, the younger age group's serum triglycerides, but did not change xylitol 's effects on VLDL and HDL levels of either age group. In the fecal micro flora, it was seen that taking the xylitol treatment caused a decrease, from washout, in amounts of all microbes studied, while the addition of inulin increased the fecal Lactobacilli counts of the older age group. Interestingly, stool qualities responded differently by age. Both treatments made the older population's stool more firm, while the same treatments made the younger population's stool more loose. Despite the added benefits, there was an increase in flatulence-small with the xylitol treatment, but nearly a three-fold increase with the addition of inulin. In conclusion, xylitol alone or with the addition of inulin can be labeled as a functional food