Resource Policy in an Endogenously Growing Economy

In a decentralized open economy model with an endogenous growth sector and a renewable resource sector a steady state-balanced growth equilibrium will at best be attained by chance. An interior equilibrium where both sectors exist and the resource sector is in equilibrium while the other sector grows can be achieved by the help of government policy. The optimum equilibrium is unstable in the decentralized economy and active government policy is needed to enforce it. Apparently contradicting policies may be needed to first move the economy to the optimal equilibrium and then to keep it there. In the current model the resource good is exported in exchange for a foreign consumption good. Hence a tariff on imports will have the same qualitative effects as a harvest fee.

Tight-binding description of Landau levels of graphite in tilted magnetic fields

The electronic structure of Bernal-stacked graphite subject to tilted magnetic fields is studied theoretically. The minimal nearest-neighbor tight-binding model with the Peierls substitution is employed to describe the structure of Landau levels. We show that while the orbital effect of the in-plane component of the magnetic field is negligible for massive Dirac fermions in the vicinity of the K point of the graphite Brillouin zone, at the H point it leads to the experimentally observable splitting of Landau levels, which grows approximately linearly with the in-plane field intensity.Comment: 15 pages, 6 figure

Organic farming on grasslands

Sustainable agriculture has currently been considerably supported by the EU which positively affects development of organic farming in EU member states. Along with expansion of organic farming itself, importance of its production and non-production function rises as well. Both these functions are expected to be mutually balanced so as the organic farms were not focused on one-sided production. To reach such balance the grant programmes should be suitably set so that the farms were motivated to farm on arable land and permanent grasslands on one side and fulfil non-production function of agriculture on the other side as well. The balance of grant programmes can be estimated according to the way how organic farming is carried on. This article is focused on assessment of condition of organic farming in the Czech Republic and taking advantage of agroenvironmental programmes

Undrained shear strength in dependence on the quantity of free water and firmly adsorbed water in fully saturated clays

The article describes the dependence between the undrained shear strength of fully saturated cohesive soils, the quantity of intergrain water and mineralogical properties of soils on the basis of theoretical analysis and practical tests on monomineral clay samples, it was determined that the total quantity of intergrain water is composed of free pore water and the firmly adsorbed water on the external surface of clay grains. The undrained shear strength of saturated soils is precisely dependent on the quantity of free water. The amount of free water and likewise the thickness of the water film around the clay grains are the same for different soils at the same undrained shear strength. The total quantity of firmly adsorbed water and the total quantity of integration water depends on the specific surface of soils

Design of Software Application

Bakalárska práca sa zameriava na návrh a implementáciu riešenia pre konkrétnu spoločnosť za účelom zvýšenia efektívnosti fungovania informačného systému. Práca analyzuje spoločnosť prostredníctvom SWOT analýzy a analýzy Porterovho modelu piatich síl a následne navrhuje konkrétne riešenie ktoré je realizované spoločnosťou v praxi.Bachelor thesis focuses on the design and implementation of solutions for a specific company to increase the efficiency of the information system. The work analyzes the company through a SWOT analysis and Porter's five forces model and subsequently propose specific solutions which are realized by the company in the practice.

Structural properties of silicon dioxide thin films densified by medium-energy particles

Classical molecular-dynamics simulations have been carried out to investigate densification mechanisms in silicon dioxide thin films deposited on an amorphous silica surface, according to a simplified ion-beam assisted deposition (IBAD) scenario. We compare the structures resulting from the deposition of near-thermal (1 eV) SiO$_{2}$ particles to those obtained with increasing fraction of 30 eV SiO$_{2}$ particles. Our results show that there is an energy interval - between 12 and 15 eV per condensing SiO$_2$ unit on average - for which the growth leads to a dense, low-stress amorphous structure, in satisfactory agreement with the results of low-energy ion-beam experiments. We also find that the crossover between low- and high-density films is associated with a tensile to compressive stress transition, and a simultaneous healing of structural defects of the {\em a-}SiO$_2$ network, namely three- and four-fold rings. It is observed, finally, that densification proceeds through significant changes at intermediate length scales (4--10 \AA), leaving essentially unchanged the ``building blocks'' of the network, viz. the Si(O$_{1/2}$)$_{4}$ tetrahedra. This latter result is in qualitative agreement with the mechanism proposed to explain the irreversible densification of amorphous silica recovered from high pressures ($\sim$ 15--20 GPa).Comment: 12 pages including 10 postscript figures; submitted to Phys. Rev. B; related publications can be found on web site http://www.centrcn.umontreal.ca/~lewi