120 research outputs found

    Importance of standardizing raw milk quality for the enhancement of Croatian market competitiveness

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    In the European Union member states (EU), it is necessary to evaluate hygienic condition of milk in order to determine milk price. Similar requirement was set by the Republic of Croatia in 2000. The Rulebook defines minimal quality criteria that fresh raw milk must have in order to be purchased. Upon completion of analysis, milk is classified into quality classes, each having a defined price. Increased value of somatic cell count (SCC) (higher than 400.000/ml) and MO (higher than 100.000/ml) directly decreases the raw milk price, while higher content of fat and protein causes its increase. Since the system of market milk price formation was established, producers have been stimulated to produce milk of higher quality: in a total of milk being purchased, the highest quality milk share increased from 23.3% to 34.2%. Referring to a trend of milk purchase price reduction in the EU, and considering the current high milk purchase price in Croatia, Croatian producers have an opportunity to improve conditions in milk industry before the country joins the EU. Current milk production needs to be increased and milk quality also needs to be improved, in order to make Croatian milk production more competitive on the European, as well as world market.milk quality, competitiveness, market, Croatia, Food Consumption/Nutrition/Food Safety, Livestock Production/Industries, Marketing,

    Metric fluctuations and its evolution during inflation

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    W discuss the evolution of the fluctuations in a symmetric ϕc\phi_c-exponential potential which provides a power-law expansion during inflation using both, the gauge invariant field Φ\Phi and the Sasaki-Mukhanov field.Comment: version accepted in EPJ

    Influence of Microclimate in a Barn on Dairy Cows’ Welfare and Production

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    Microclimate in a barn has a major influence on cows’ health and welfare, as well as on milk production of dairy cows. Extreme values of air temperature and humidity can negatively influence barn conditions, having thus negative effect on cows kept in barns. The research aimed to investigate influence of basic microclimate parameters on a modern dairy farm located in Eastern Croatia. Research period referred to summer season, from 01 June – 31 August 2013. Measurements were carried out in three time intervals (00:00-08:00; 08:00-16:00; 16:00-00:00) for the following parameters: temperature (T), humidity (H) and temperature-humidity index (THI). The results showed that the values of T and THI were higher than optimal values recommended by the scientific literature. Differences between the daily interval for T, H and THI were statistically highly significant (p<0.0001). Furthermore, significant difference (p<0.0001; p<0.05) was determined for all investigated parameters between June and July, and June and August. However, between July and August there was no significant difference. Although measurements were performed on a modern dairy farm equipped with additional cooling by fans, it was not sufficient to create an optimal microclimate environment for dairy cows. Because of that, additional measures need to be undertaken during summer months (for example, installation of water sprinklers) to reduce the air temperature and temperature-humidity index, all with the purpose to increase comfort of dairy cows and to prevent decrease in milk production

    Determinant-Gravity: Cosmological implications

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    We analyze the action d4xdetBgμν+CRμν\int d^4x \sqrt{\det||{\cal B} g_{\mu\nu}+ {\cal C} R_{\mu\nu}}|| as a possible alternative or addition to the Einstein gravity. Choosing a particular form of B(R)=R{\cal B}(R)= \sqrt {R} we can restore the Einstein gravity and, if B=m2{\cal B}=m^2, we obtain the cosmological constant term. Taking B=m2+B1R{\cal B} = m^2 + {\cal B}_1 R and expanding the action in 1/m2 1/m^2, we obtain as a leading term the Einstein Lagrangian with a cosmological constant proportional to m4m^4 and a series of higher order operators. In general case of non-vanishing B{\cal B} and C{\cal C} new cosmological solutions for the Robertson-Walker metric are obtained.Comment: revtex format, 5 pages,8 figures,references adde

    Quantum Cosmology for a Quadratic Theory of Gravity

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    For pure fourth order (LR2{\cal{L}} \propto R^2) quantum cosmology the Wheeler-DeWitt equation is solved exactly for the closed homogeneous and isotropic model. It is shown that by imposing as boundary condition that Ψ=0\Psi = 0 at the origin of the universe the wave functions behave as suggested by Vilenkin.Comment: 13 pages, latex,no figure

    Extended Gravity Theories and the Einstein-Hilbert Action

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    I discuss the relation between arbitrarily high-order theories of gravity and scalar-tensor gravity at the level of the field equations and the action. I show that (2n+4)(2n+4)-order gravity is dynamically equivalent to Brans-Dicke gravity with an interaction potential for the Brans-Dicke field and nn further scalar fields. This scalar-tensor action is then conformally equivalent to the Einstein-Hilbert action with n+1n+1 scalar fields. This clarifies the nature and extent of the conformal equivalence between extended gravity theories and general relativity with many scalar fields.Comment: 12 pages, Plain Latex, SUSSEX-AST-93/7-

    Systems thinking for the transition to zero pollution

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    Systems approaches are vital for coordinating decision-making in the face of complex issues because they provide the whole picture view needed to avoid negative unintended consequences and to generate genuine benefits. This paper explains how systems thinking can be used to address environmental pollution and support decision-makers in finding solutions

    Tyre wear particles are toxic for us and the environment

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    This briefing paper discusses the current knowledge on the effects of tyre wear particles on our health and environment, highlights the need for an ambitious research agenda to build further understanding of the impacts on people and nature and develop solutions, and includes recommendations for policymakers

    Accelerated Cosmological Models in Ricci squared Gravity

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    Alternative gravitational theories described by Lagrangians depending on general functions of the Ricci scalar have been proven to give coherent theoretical models to describe the experimental evidence of the acceleration of universe at present time. In this paper we proceed further in this analysis of cosmological applications of alternative gravitational theories depending on (other) curvature invariants. We introduce Ricci squared Lagrangians in minimal interaction with matter (perfect fluid); we find modified Einstein equations and consequently modified Friedmann equations in the Palatini formalism. It is striking that both Ricci scalar and Ricci squared theories are described in the same mathematical framework and both the generalized Einstein equations and generalized Friedmann equations have the same structure. In the framework of the cosmological principle, without the introduction of exotic forms of dark energy, we thus obtain modified equations providing values of w_{eff}<-1 in accordance with the experimental data. The spacetime bi-metric structure plays a fundamental role in the physical interpretation of results and gives them a clear and very rich geometrical interpretation.Comment: New version: 26 pages, 1 figure (now included), Revtex
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