Relativistički model kvarkova

A general Lorentz-covariant quark model of mesons, whose nonrelativistic limit corresponds to Isgur-Scora-Grinstein-Wise model, is constructed. It possesses the heavy quark symmetry and can be easily applied to calculation of form factors. Besides it can be engaged in novel tasks, such a the investigation of the two photon decay of scalar mesons. Its behaviour in the infinite momentum frame and the light cone is discussed.Izveli smo poopćeni Lorentz-kovarijantni model mezona čiji nerelativistički limes odgovara Isgur-Scora-Grinstein-Wiseovom modelu. Model ima teško-kvarkovsku simetriju i može se primijeniti za računanje faktora oblika. Osim toga u ovom se modelu mogu rješavati nove zadaće kao što je dvofotonski raspad skalarnih mezona. Raspravljamo svojstva modela u sustavu beskonačnog impulsa i na svjetlosnom stošcu

Covariant and Heavy Quark Symmetric Quark Models

There exist relativistic quark models (potential or MIT-bag) which satisfy the heavy quark symmetry (HQS) relations among meson decay constants and form factors. Covariant construction of the momentum eigenstates, developed here, can correct for spurious center-of-mass motion contributions.Proton form factor and M1 transitions in quarkonia are calculated. Explicit expression for the Isgur-Wise function is found and model determined deviations from HQS are studied. All results depend on the model parameters only. No additional ad hoc assumptions are needed.Comment: 34 pages (2 figures not included but avaliable upon request), LATEX, (to be published in Phys.Rev.D

Influence of a Primer on the Velocity of Detonation of ANFO and Heavy ANFO Blends

ANFO is the most common explosive for civil use in the fields of mining and civil engineering. Some properties of ANFO, like poor water resistance, low density and low velocity of detonation can be improved by mixing ANFO with a certain percentage of an emulsion. These explosives are called Heavy ANFO blends. This paper presents a study of the influence of a primer on the velocity of detonation of ANFO and Heavy ANFO blends. Three types of primers were used for the initiation of the explosives and the velocity of detonation was measured in situ by a continuous method. Based on the results of these measurements, the relationship between the detonation velocity of the primer used and the detonation velocity of the primed explosive were established

Characteristics and movement patterns of a recently established invasive

The presence of the signal crayfish, Pacifastacus leniusculus, in waterbodies of Europe is of high concern due to its potentially major ecological impact on invaded ecosystems and native crayfish. In this study, we examined population characteristics and spatial dynamics of a recently established signal crayfish population near the edge of its invasive range in the Mura river (Croatia), by analyzing population density, fecundity, and sex and size structure, as well as movement patterns. The obtained results revealed that the examined population is characterized by relatively low population density, balanced sex and size structure of adult crayfish, and high spatial activity of examined individuals, with an average daily movement of 28 m/day. Pleopodal fecundity was in a similar range to other signal crayfish populations in Europe. The large minimal size of caught mature females (85 mm total length), coupled with the estimated low population density (0.8–1.2 crayfish.m-2), suggested that the examined population has not reached its maximum density yet. Obtained results represent baseline information for the development of monitoring procedures and management strategies aimed at signal crayfish control within the Mura and Drava catchments and also highlight the importance of understanding local factors controlling invasive species’ population dynamics and productivity

Influence of explosive charge temperature on the velocity of detonation of ANFO explosives

ANFO is the most common explosive for civil use in the fields of mining and civil engineering. The effect of the explosive and the quantity of energy released by the detonation depends on the velocity of detonation. The influence on explosive performance of a large number of physical aspects of ANFO explosives and the conditions of initiation during blasting operations are mostly known, but the influence of the charge temperature on the velocity of detonation is not known. In order to quantify that influence, research on laboratory samples of smaller diameter and field samples of larger diameter, detonated in steel pipes, has been carried out. By processing and analysing the measured results the influence of charge temperature on the velocity of detonation of ANFO explosive has been determined

Characteristics and movement patterns of a recently established invasive Pacifastacus leniusculus

The presence of the signal crayfish, Pacifastacus leniusculus, in waterbodies of Europe is of high concern due to its potentially major ecological impact on invaded ecosystems and native crayfish. In this study, we examined population characteristics and spatial dynamics of a recently established signal crayfish population near the edge of its invasive range in the Mura river (Croatia), by analyzing population density, fecundity, and sex and size structure, as well as movement patterns. The obtained results revealed that the examined population is characterized by relatively low population density, balanced sex and size structure of adult crayfish, and high spatial activity of examined individuals, with an average daily movement of 28 m/day. Pleopodal fecundity was in a similar range to other signal crayfish populations in Europe. The large minimal size of caught mature females (85 mm total length), coupled with the estimated low population density (0.8–1.2 crayfish.m-2), suggested that the examined population has not reached its maximum density yet. Obtained results represent baseline information for the development of monitoring procedures and management strategies aimed at signal crayfish control within the Mura and Drava catchments and also highlight the importance of understanding local factors controlling invasive species’ population dynamics and productivity

Characteristics and movement patterns of a recently established invasive Pacifastacus leniusculus population in the river Mura, Croatia

The presence of the signal crayfish, Pacifastacus leniusculus, in waterbodies of Europe is of high concern due to its potentially major ecological impact on invaded ecosystems and native crayfish. In this study, we examined population characteristics and spatial dynamics of a recently established signal crayfish population near the edge of its invasive range in the Mura river (Croatia), by analyzing population density, fecundity, and sex and size structure, as well as movement patterns. The obtained results revealed that the examined population is characterized by relatively low population density, balanced sex and size structure of adult crayfish, and high spatial activity of examined individuals, with an average daily movement of 28 m/day. Pleopodal fecundity was in a similar range to other signal crayfish populations in Europe. The large minimal size of caught mature females (85 mm total length), coupled with the estimated low population density (0.8–1.2 crayfish.m-2), suggested that the examined population has not reached its maximum density yet. Obtained results represent baseline information for the development of monitoring procedures and management strategies aimed at signal crayfish control within the Mura and Drava catchments and also highlight the importance of understanding local factors controlling invasive species’ population dynamics and productivity

Vyzkum racionalnich dopravnich systemu pro zemedelstvi CR v podminkach platnosti legislativy EU.

Available from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi