75 research outputs found
Use of Green Sulla Forage for Feeding. 2. Effects on Lamb Carcass and Meat Quality
Diets with 2.5% of condensed tannins (CT) from carob pulp have been showed to reduce lamb carcass weight, yield and fatness, as a consequence of lower digestibility due to strong protein-tannin bonds. Moreover the diets lightened meat colour and negatively affected meat sensory properties (Priolo et al., 2000). There is evidence that some tannin-rich legumes have weaker stability of the protein-tannin complex post-rumen (McSweeney et al., 2001). Since the CT-containing sulla (Hedysarum coronarium L.) demonstrated improved lamb growth performance in comparison with CT-lacking annual ryegrass (Lolium multiflorum Lam. subsp. wersterwoldicum) (Giambalvo et al., 2005), this study examined the impact of CT from sulla on carcass characteristics and meat quality
Effects of feeding green forage of sulla (Hedysarum coronarium L.) on lamb growth and carcass and meat quality.
The nutritional effects of sulla (Hedysarum coronarium L.) forage containing condensed tannins (CT) on growth of lambs, and carcass and meat quality were investigated. Thirty-two male Comisana lambs aged 100 ± 8 days weighing 19.0 ± 2.8 kg were fed fresh forage of sulla or CT-free annual ryegrass (Lolium multiflorum Lam. subsp. Wersterwoldicum) for 49 days until slaughter; in addition, each lamb was supplied with 200 g/days of concentrate. Eight lambs per diet had been previously treated with anthelmintic drugs to remove nematode parasites. Measurements of BW and feed intake, and counts of faecal nematode eggs were made. Carcass parameters were recorded after slaughter, and tissue components of the hind leg were determined. Longissimus dorsi meat was evaluated for pH, colour, thawing and cooking losses, Warner-Bratzler shear force, chemical composition and sensory properties based on triangle tests. Relative to ryegrass-fed lambs, sulla-fed lambs had significantly greater dry matter (DM) and protein intake, a more favourable feed conversion ratio, and superior growth rate, final BW at 150 days of age, carcass weight, yield and fatness. These results were attributed to the high protein and non-structural carbohydrate content of sulla, and also to the moderate CT content of sulla (16.7 and 20.3 g/kg of DM in offered and consumed sulla forage, respectively). Anthelmintic treatment did not affect lamb growth, as the level of parasitic infection (initial and final) was low. The physical, chemical and sensory properties of the lamb meat were not influenced by diet
The supernova rate in local galaxy clusters
We report a measurement of the supernova (SN) rates (Ia and core-collapse) in
galaxy clusters based on the 136 SNe of the sample described in Cappellaro et
al. (1999) and Mannucci et al. (2005).
Early-type cluster galaxies show a type Ia SN rate (0.066 SNuM) similar to
that obtained by Sharon et al. (2007) and more than 3 times larger than that in
field early-type galaxies (0.019 SNuM). This difference has a 98% statistical
confidence level. We examine many possible observational biases which could
affect the rate determination, and conclude that none of them is likely to
significantly alter the results. We investigate how the rate is related to
several properties of the parent galaxies, and find that cluster membership,
morphology and radio power all affect the SN rate, while galaxy mass has no
measurable effect. The increased rate may be due to galaxy interactions in
clusters, inducing either the formation of young stars or a different evolution
of the progenitor binary systems.
We present the first measurement of the core-collapse SN rate in cluster
late-type galaxies, which turns out to be comparable to the rate in field
galaxies. This suggests that no large systematic difference in the initial mass
function exists between the two environments.Comment: MNRAS, revised version after referee's comment
High-gain filters for non-linear stochastic systems
The use of high-gains in the filtering problem for non-linear stochastic systems is studied. It is shown that a high-gain filter has the same structure as a Luenberger observer. The use of high-gains is studied in the cancellation of non-linearities in order to simplify the filter design for non-linear systems. Singular perturbation techniques are used to show how the error dynamics reaches stable equilibrium in a very fast transient time, ensuring that the slow dynamics of the filter are just those of the non-linear stochastic system. © 1990 Taylor & Francis Group, LLC
Analysis and synthesis in the simulink environment of control laws for DC motors: a real-time implementation with the microcontroller BASIC stamp II as a simple tool for an education control laboratory
This paper describes a simple and cheap experimental apparatus that has been developed at Università di Roma Tor Vergata for educational purposes; this tool is currently used in the course "Laboratorio d'Automatica" (Laboratory of Automatic Control), which is offered in the first year of a three-year university programme ("Laurea" degree) in Automatic Control. The most notable feature of this experimental apparatus is that it can be controlled in real time from Simulink; the paper reports on several experimental tests for students using this tool who are only familiar with the fundamentals of calculus, geometry, physics and computer sciences
Modelling and controlling one-degree-of-freedom impacts under elastic/plastic deformations
Adaptive compensation of modeled friction using a RBF neural network approximation
We present a compensation technique for a friction model, which captures problematic friction effects such as Stribeck effect, hysteresis, pre-sliding displacement, stick-slip motion and stiction. The proposed control utilizes a PD control structure and an adaptive estimate of the friction force. Specifically, a Radial Basis Function (RBF) is used to compensate the effects of the non-linear friction model. The asymptotic convergence of parameter estimation errors is achieved for the system in adaptive observer form using Barbalat's Lemma. We also introduce a parameter estimation projection algorithm to avoid the parameter estimates drift when the condition of persistency of excitation is not verified. Finally, to support the theoretical concepts, we present dynamic simulations for the proposed control scheme
Linearization of discrete-time nonlinear systems through state immersion and lie symmetries
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