Effect of type of suckling and length of lactation period on carcass and meat quality in intensive lamb production systems

This study examined the effect of the type of suckling and length of lactation period on carcass characteristics and lamb meat quality in the Manchega Spanish breed. Fifty-eight lambs were divided into three groups differing in their management systems from birth to slaughter: The first group (W; n=21) was weaned at 35 days old. In the second one (HW; n=18) ewes were subjected to milking simultaneously with suckling of lambs ("half milk") from 15 to 45 days old. The third group (UW; n=19) remained with their mothers from birth to slaughter. UW lambs had higher dressing proportion (48.3%) than the other two groups, a higher fatness score (6.1) and larger amounts kidney and pelvic fat (342.63 g). Shrinkage losses and carcass conformation score did not differ among groups. Among the meat quality traits, UW lambs had higher L* parameter values (50.2). No statistical differences were found in the other parameters assessed.     

Comparison of environmental impacts of building structures with in situ cast floors and with precast concrete floors

In this paper, the environmental impacts of two types of slab systems are studied. The first type, a concrete-based one-way spanning slab, is the most common solution in residential buildings in Spain. The second type, a hollow core slab floor, is increasingly becoming more used in buildings, but is not being broadly used in residential buildings as yet. The study is undertaken through the Life Cycle Analysis methodology, applying the EPS 2000 method. The assessment shows that the environmental impact of a building structure with precast concrete floors is 12.2% lower than that with in situ cast floors for the defined functional unit.     

Optimization of a thick polyvinyl alcohol-acrylamide photopolymer for data storage using a combination of angular and peristrophic holographic multiplexing

The capability of polyvinyl alcohol-acrylamide photopolymer materials to obtain angularly multiplexed holographic gratings has been demonstrated [Appl. Phys. B 76, 851 (2003)]. A combination of two multiplexing methods--peristrophic and angular multiplexing--is used to record 60 holograms. An exposure schedule method is used to optimize the capability of the photopolymerizable holographic material and obtain holograms with a higher, more uniform diffraction efficiency. In addition, because of this exposure schedule method, the entire dynamic range (M#) of the material will be exploited, obtaining values of approximately M# approximately 9 in layers approximately 800 microm thick.     

Rheological properties of Colombian‐Caribbean‐coast sour cream from goat milk

The viscoelastic properties provide guidelines to help give meaning to the observations on food products, to relate them to the way in which their structures behave, and to predict or modify their properties. This study analyses the incidence of varying the initial fat content of goat milk on the rheological properties of prepared sour cream. Storage (G′) and loss modulus (G″), as well as complex viscosity (η*) and loss factor values (tan δ), were determined at different initial fat contents in goat milk (3.75%, 4.00% and 4.25%). The experimental data were adapted to Maxwell model. All the prepared samples of sour cream meet national and international microbiological standards, and the initial fat content of goat milk influenced the viscoelastic behaviour of sour cream. Structures with prevalent elastic (G′) behaviour were found, and the product that was prepared from goat milk with 4.00% fat content showed the highest elastic modules. This sour cream exhibited higher firmness and better adherence when compared to the samples that were obtained from 3.75% and 4.25% fat‐content milk. This sample also exhibited the lowest tangent of the phase angle. Sour cream that was prepared from milk with higher fat content (4.00% and 4.25%) exhibited a semi‐solid behaviour along the entire temperature range that was studied. On the contrary, rheological properties of sour cream from 3.75% fat‐content milk tend to increase at temperatures above 333.15 K. The viscoelastic behaviour of sour cream was successfully explained under Maxwell model, while data from dynamic viscosity (η′) were adapted to Arrhenius model. Microstructure analysis to the sample considered as the best (from milk with 4.00% of initial fat content) showed that the protein network presented a rough, open surface with aggregates and wide spaces.     

Measure the Dissolved Oxygen Consumed by Red Wines in Aging Tanks

The techniques of accelerated wine aging imply the addition of wood pieces of oak to the wine and the use of small doses of oxygen (micro-oxygenation). The dosage of extremely small amounts needs the knowledge of the dissolved oxygen (DO) at every moment in order to assure its correct assimilation. This work presents the first results of a study about the evolution of the dissolved oxygen content in red wines during alternative accelerated aging. Samples were treated in stainless steel vessels with wood pieces and low micro-oxygenation levels. French oak was applied with different toasting levels: light, medium, and high. Quality parameters of the wine were monitored. The knowledge of wine DO levels allowed developing a controlled micro-dosage in the different phases during the accelerated aging. The wine was able to use the whole amount of oxygen provided throughout the process.     

Response components of LiF:Mg,Ti around a moderated Am-Be neutron source

The responses of TLD-1010, TLD-700 and TLD-600 thermoluminescence dosemeters to the radiation field inside a water tank enclosing an isotopic 241Am-Be neutron source are analysed. Separate contributions coming from thermal neutrons, neutrons with energies above thermal and gamma rays to the total response of the three types of TLD are obtained. This is accomplished by assuming that the gamma responses for materials with different 6Li enrichments are identical and that the neutron response of TLD-700 is negligible compared to TLD-100 and TLD-600. The last assumption is tested by Monte Carlo simulations of the neutron energy spectrum at the points where the TLDs are irradiated.     

Conservation of Cervus elaphus meat in modified atmospheres

This study examines the effect of three types of modified atmospheres, each with a different gas composition (A:40% CO(2)+60% N(2); B:80% CO(2)+20% O(2); C:80% CO(2)+20% N(2)), on the development of meat quality of Cervus elaphus in order to suggest a gas composition that best preserves this type of meat. Meat quality was assessed by examining pH, colour as L(?)a(?)b(?) values, drip loss (DL), cooking loss (CL) and shear force (SF). In samples of group A, pH values tended to be higher in all storage periods than those packed with 80% CO(2) and significant differences (P<0.001) among the groups were found at 16 d of storage. Gas composition affected a(?) and b(?) parameters (P<0.001), in samples packed with O(2), the b(?) values were higher than in other groups, while the opposite was true in a(?) values. Similar values of DL and CL were observed for all treatments and both parameters increased over time. SF values decreased with ageing, with similar values observed for all treatments.     

Algunas relaciones entre modelos Marcovianos de redes de colas

Resumen En este artículo se describen algunos de los modelos marcovianos de redes de colas más interesantes, como los de Jackson, Gordon y Newell, Reiser y Kobayashi y otros, estudiando las relaciones existentes entre ellos. Se demuestra que la solución conocida como “forma de producto” es válida para todos ellos con las modificaciones apropiadas en cada caso.

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In this paper are described some of the more interesting markovian models of queueing networks as the Jackson, Gordon and Newell, Reiser and Kobayashi, and other. We study the relations among them. It’s proved that solution we know as “Product form” is valid for all, with the appropiate modifications for every case.

     

Altitudinal gradients of PBDEs and PCBs in fish from European high mountain lakes

A first case of temperature-dependent distribution of polybromodiphenyl ethers (PBDEs) in remote areas is shown. Analysis of these compounds in fish from Pyrenean lakes distributed along an altitudinal transect shows higher concentrations at lower temperatures, as predicted in the global distillation model. Conversely, no temperature-dependent distribution is observed in a similar transect in the Tatra mountains (Central Europe) nor in fish from high mountain lakes distributed throughout Europe. The fish concentrations of polychlorobiphenyls (PCBs) examined for comparison showed significant temperature correlations in all these studied lakes. Cold trapping of both PCBs and PBDEs concerned the less volatile congeners. In the Pyrenean lake transect the concentrations of PCBs and PBDEs in fish were correlated despite the distinct use of these compounds and their 40 year time lag of emissions to the environment. Thus, temperature effects have overcome these anthropogenic differences constituting at present the main process determining their distributions. These cases of distinct PBDEs and PCBs behavior in high mountains likely reflect early stages in the environmental distribution of the former since they have been under secondary redistribution processes over much shorter time than the latter.