11,381 research outputs found
Veal calf industry economics
This paper provides an outline of the veal industry, its standing relative to other cattle farming enterprises, and its future prospects. In 2008 some 20 per cent of bovines slaughtered in the EU were for veal production and
about one-third of them were dairy calves. France, the Netherlands and Italy were Europe’s leading producers. Veal consumption in the European Union has been in steady decline since 1970. In 2008, it averaged 1.6 kg per capita,
with France and Italy being the largest consumers. Despite variations in farming systems and carcass characteristics from one country to another, veal production is an important outlet for milk replacer producers and provides
a market for their industrial dairy products. Regular changes in production factors such as the price of 8-day-old calves and milk replacers and their availability engender recurrent output fluctuations. Veal calf production
plays a major part in regulating the milk and bovine-meat markets: it has largely contributed to stemming dairy (and sometimes meat) surpluses. However, the context has changed since 2008 with no more surplus milk supply and reduced EU-support for incorporating skimmed milk powder into milk feeds. Therefore, the relative attractiveness of other productions using 8-day-old calves and the support policies for cattle farming as a whole will affect the future of the veal calf industry
A zero-thickness mortar/ interface formulation with application to fracture mechanics
A zero-thickness mortar/interface element formulation is briefly described and demonstrated. This element may be considered as an extension of traditional zero-thickness interface element, in order to represent material interfaces located in between subdomains with non-matching FE meshes. In the context of small strain analysis, these elements may be equipped with the same type of constitutive laws as traditional interface elements. Therefore, if friction or fracture-mechanics-based laws are adopted, mortar/interface elements may be used to represent frictional sliding or cracking following the lines (surfaces) along which they have been pre-inserted. Two basic verification examples of this type are presented, showing that the model can correctly represent uniform states of stress and deformation when connecting unmatched mesh subdomains
The Metallicity Gradient of the Old Galactic Bulge Population
Understanding the structure, formation and evolution of the Galactic Bulge
requires the proper determination of spatial metallicity gradients in both the
radial and vertical directions. RR Lyrae pulsators, known to be excellent
distance indicators, may hold the key to determining these gradients. Jurcsik &
Kovacs (1996) has shown that RR Lyrae light curves and the phase difference of
their Fourier decomposition, {\phi}31, can be used to estimate photometric
metallicities. The existence of galactic bulge metallicity gradients is a
currently debated topic that would help pinpoint the Galaxy's formation and
evolution. A recent study of the OGLE-III Galactic Bulge RR Lyrae Population by
Pietrukowicz et al. (2012) suggests that the spatial distribution is uniform.
We investigate how small a gradient would be detectable within the current S/N
levels of the present data set, given the random and systematic errors
associated with the derivation of a photometric metallicity versus spatial
position relationship.Comment: Proc. of the workshop "Asteroseismology of stellar populations in the
Milky Way" (Sesto, 22-26 July 2013), Astrophysics and Space Science
Proceedings, (eds. A. Miglio, L. Girardi, P. Eggenberger, J. Montalban
A self optimizing synthetic organic reactor system using real-time in-line NMR spectroscopy
A configurable platform for synthetic chemistry incorporating an in-line benchtop NMR that is capable of monitoring and controlling organic reactions in real-time is presented. The platform is controlled via a modular LabView software control system for the hardware, NMR, data analysis and feedback optimization. Using this platform we report the real-time advanced structural characterization of reaction mixtures, including 19F, 13C, DEPT, 2D NMR spectroscopy (COSY, HSQC and 19F-COSY) for the first time. Finally, the potential of this technique is demonstrated through the optimization of a catalytic organic reaction in real-time, showing its applicability to self-optimizing systems using criteria such as stereoselectivity, multi-nuclear measurements or 2D correlations
Optimal Taxation Rule Reversal in the Presence of Gentle Polluters and Greedy Cleaners
The literature on the micro-economics of the eco-industry often assumed interiority of pollutant net emissions. In a perfectly competitive final good market vertically integrated with an upstream monopoly supply this assumption implies that an optimal tax is always greater than its associated marginal social damage. In this short note we will relax this assumption and challenge that result. The market structure generates a unique threshold on the scale of the marginal social damage, whereby for any value above the threshold an optimal tax is strictly lower and net emissions are zero
Three-dimensional memory vectorization for high bandwidth media memory systems
Vector processors have good performance, cost and adaptability when targeting multimedia applications. However, for a significant number of media programs, conventional memory configurations fail to deliver enough memory references per cycle to feed the SIMD functional units. This paper addresses the problem of the memory bandwidth. We propose a novel mechanism suitable for 2-dimensional vector architectures and targeted at providing high effective bandwidth for SIMD memory instructions. The basis of this mechanism is the extension of the scope of vectorization at the memory level, so that 3-dimensional memory patterns can be fetched into a second-level register file. By fetching long blocks of data and by reusing 2-dimensional memory streams at this second-level register file, we obtain a significant increase in the effective memory bandwidth. As side benefits, the new 3-dimensional load instructions provide a high robustness to memory latency and a significant reduction of the cache activity, thus reducing power and energy requirements. At the investment of a 50% more area than a regular SIMD register file, we have measured and average speed-up of 13% and the potential for power savings in the L2 cache of a 30%.Peer ReviewedPostprint (published version
Command vector memory systems: high performance at low cost
The focus of this paper is on designing both a low cost and high performance, high bandwidth vector memory system that takes advantage of modern commodity SDRAM memory chips. To successfully extract the full bandwidth from SDRAM parts, we propose a new memory system organization based on sending commands to the memory system as opposed to sending individual addresses. A command specifies, in a few bytes, a request for multiple independent memory words. A command is similar to a burst found in DRAM memories, but does not require the memory words to be consecutive. The command is sent to all sections of the memory array simultaneously, thus not requiring a crossbar in the proper sense. Our simulations show that this command based memory system can improve performance over a traditional SDRAM-based memory system by factors that range between 1.15 up to 1.54. Moreover, in many cases, the command memory system outperforms even the best SRAM memory system under consideration. Overall the command based memory system achieves similar or better results than a 10 ns SRAM memory system (a) using fewer banks and (b) using memory devices that are between 15 to 60 times cheaper.Peer ReviewedPostprint (published version
Mean-Field-Theory for Polymers in Mixed Solvents Thermodynamic and Structural Properties
Theoretical aspects of polymers in mixed solvents are considered using the
Edwards Hamiltonian formalism. Thermodynamic and structural properties are
investigated and some predictions are made when the mixed solvent approaches
criticality. Both the single and the many chain problems are examined. When the
pure mixed solvent is near criticality, addition of a small amount of polymers
shifts the criticality towards either enhanced compatibility or induced phase
separation depending upon the value of the parameter describing the interaction
asymmetry of the solvents with respect to the polymer. The polymer-solvent
effective interaction parameter increases strongly when the solvent mixture
approaches criticality. Accordingly, the apparent excluded volume parameter
decreases and may vanish or even become negative. Consequently, the polymer
undergoes a phase transition from a swollen state to an unperturbed state or
even take a collapsed configuration. The effective potential acting on a test
chain in strong solutions is calculated and the concept of Edwards screening
discussed. Structural properties of ternary mixtures of polymers in mixed
solvents are investigated within the Edwards Hamiltonian model. It is shown
that the effective potential on a test chain in strong solutions could be
written as an infinite series expansion of terms describing interactions via
one chain, two chains etc. This summation can be performed following a similar
scheme as in the Ornstein-Zernike series expansion.Comment: accepted in Macromol. Theory Simu
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