The transition process: Stimulating free entrepreneurship

The text consists of two parts. In the first we expound the thesis that transition is actually a process of creation of institutional preconditions for development of private entrepreneurship at a given moment and under the inherited circumstances. To create an environment that stimulates free entrepreneurship and enables a successful transition requires a lot of knowledge, creativity and pragmatism (there is no general model). The rest remains on the entrepreneurs. In the second part we analyse the experience of FRY before and after the change of regime. During the former regime FRY was an example of degenerative connection between politics and economy geared to prevent reforms. The task of the new government is to make a radical break with the earlier practice. If the reform is not radical and not aiming to create an institutional environment that fully stimulates competition and private entrepreneurship (which has not been the case so far), it has no good prospects to succeed

Incommensurate superfluidity of bosons in a double-well optical lattice

We study bosons in the first excited Bloch band of a double-well optical lattice, recently realized at NIST. By calculating the relevant parameters from a realistic nonseparable lattice potential, we find that in the most favorable cases the boson lifetime in the first excited band can be several orders of magnitude longer than the typical nearest-neighbor tunnelling timescales, in contrast to that of a simple single-well lattice. In addition, for sufficiently small lattice depths the excited band has minima at nonzero momenta incommensurate with the lattice period, which opens a possibility to realize an exotic superfluid state that spontaneously breaks the time-reversal, rotational, and translational symmetries. We discuss possible experimental signatures of this novel state.Comment: 4 pages, 5 figures

Polymers Based on Renewable Raw Materials – Part II

A short review of biopolymers based on starch (starch derivatives, thermoplastic starch), lignin and hemicelluloses, chitin (chitosan) and products obtained by degradation of starch and other polysaccharides and sugars (poly(lactic acid), poly(hydroxyalkanoates)), as well as some of their basic properties and application area, are given in this part. The problem of environmental and economic feasibility of biopolymers based on renewable raw materials and their competitiveness with polymers based on fossil raw materials is discussed. Also pointed out are the problems that appear due to the increasing use of agricultural land for the production of raw materials for the chemical industry and energy, instead for the production of food for humans and animals. The optimistic assessments of experts considering the development perspectives of biopolymers based on renewable raw materials in the next ten years have also been pointed out.At the end of the paper, the success of a team of researchers gathered around the experts from the company Bayer is indicated. They were the first in the world to develop a catalyst by which they managed to effectively activate CO - and incorporate it into polyols, used for the synthesis of polyurethanes in semi-industrial scale. By applying this process, for the first time a pollutant will be used as a basic raw material for the synthesis of organic compounds, which will have significant consequences on the development of the chemical industry, and therefore the production of polymers

One–pot synthesis of hydrophobic hydroxyapatite nano particles

A highly hydrophobic oleic acid functionalized hydroxyapatite nanoparticles were obtained by the solvothermal method. Water solutions of reactants were added in mixture of oleic acid, triethanolamine and ethanol, which was then treated in Teflon lined autoclave. The chemical composition, size and morphology of as obtained particles were determined using XRD, FT IR, FE SEM and LD PSA. In addition, sintering behaviour and microstructure of prepared material were also examined

Quantum simulation of small-polaron formation with trapped ions

We propose a quantum simulation of small-polaron physics using a one-dimensional system of trapped ions acted upon by off-resonant standing waves. This system, envisioned as an array of microtraps, in the single-excitation case allows the realization of the anti-adiabatic regime of the Holstein model. We show that the strong excitation-phonon coupling regime, characterized by the formation of small polarons, can be reached using realistic values of the relevant system parameters. Finally, we propose measurements of the quasiparticle residue and the average number of phonons in the ground state, experimental probes validating the polaronic character of the phonon-dressed excitation.Comment: accepted for publication in Phys. Rev. Let

Optimization and implementation of the wavelet based algorithms for embedded biomedical signal processing

Existing biomedical wavelet based applications exceed the computational, memory and consumption resources of low-complexity embedded systems. In order to make such systems capable to use wavelet transforms, optimization and implementation techniques are proposed. The Real Time QRS Detector and De-noising Filter are developed and implemented in 16-bit fixed point microcontroller achieving 800 Hz sampling rate, occupation of less than 500 bytes of data memory, 99.06% detection accuracy, and 1 mW power consumption. By evaluation of the obtained results it is found that the proposed techniques render negligible degradation in detection accuracy of -0.41% and SNR of -2.8%, behind 2-4 times faster calculation, 2 times less memory usage and 5% energy saving. The same approach can be applied with other signals where the embedded implementation of wavelets can be beneficial

Mechanical activation as sintering pre-treatment of talc for steatite ceramics

The effect of vibratory mill induced mechanical activation on the change of the particle size, crystallinity and the phase transformations of the minerals present in the activated material, was studied with the purpose of decreasing of the sintering temperature of talc (Mg3Si4O10(OH)2) as raw material which is the basic component of the steatite ceramics. The aims of the conducted investigation were, also, increasing of the reactivity of the comminuted raw material and establishing of the optimal activation period. The properties of the activated talc induced by mechanical force were expressed in form of the grain inertia change which was measured by means of automatic grain counter. Mechanically activated grains are the most convenient mineral form for physical concentration since the energy change of the mill-material system is recorded on them. The effect of dry grinding on the structure, particle size and shape of talc was studied by means of XRD, DTA and SEM/EDS methods. Activation of talc produced an increase of the starting surface area value progressively from 4.5 m2/g up to a maximum of 108.5 m2/g achieved at 30 min. A subsequent decrease of rate of surface area change and the rate of size reduction were observed following the prolonged grinding. Talc activated in vibratory mill for optimal 30 min showed properties which positively influence the decrease of sintering temperature and the increase of the sintering rate of steatite ceramics. [Projekat Ministarstva nauke Republike Srbije, br. 172057, br. 45008 i br. 33007

Study of barium bismuth titanate prepared by mechanochemical synthesis

Barium-bismuth titanate, BaBi4Ti4O15 (BBT), a member of Aurivillius bismuth-based layer-structure perovskites, was prepared from stoichiometric amounts of barium titanate and bismuth titanate obtained via mechanochemical synthesis. Mechanochemical synthesis was performed in air atmosphere in a planetary ball mill. The reaction mechanism of BaBi4Ti4O15 and the preparation and characteristics of BBT ceramic powders were studied using XRD, Raman spectroscopy, particle analysis and SEM. The Bi-layered perovskite structure of BaBi4Ti4O15 ceramic forms at 1100 °C for 4 h without a pre-calcination step. The microstructure of BaBi4Ti4O15 exhibits plate-like grains typical for the Bi-layered structured material and spherical and polygonal grains. The Ba2+ addition leads to changes in the microstructure development, particularly in the change of the average grain size

La-doped and La/Mn-co-doped Barium Titanate Ceramics

Barium titanate ceramics doped with 0.3 mol.% lanthanum and co-doped with 0.3 mol.% lanthanum and 0.05 mol.% manganese were investigated. The powders were prepared by a modified polymeric precursor method based on the Pechini process. The ceramics were obtained by sintering at 1300 degrees C for 8 h. The influence of dopants on structural changes and grain size reduction was analyzed. The presence of dopants influenced the tetragonality of the barium titanate crystal structure. Reduction of polygonal grain size with dopant addition was noticed. In the doped ceramics, characteristic phase transitions were shifted to lower temperatures in comparison with pure barium titanate. The dielectric permittivity value showed the tendency of a slight increase with lanthanum addition and further increase with adding of manganese. La as a single dopant increased the diffuseness of phase transitions indicating the formation of a diffuse ferroelectric material but in the co-doped ceramics the phase transition diffuseness decreased. The resistivity of the co-doped ceramics was higher than for lanthanum doped ceramics, indicating possible segregation of manganese at grain boundaries that influenced the total resistivity of the material

Lawton, Michael T: Seven aneurysms: Tenets and techniques for clipping: Thieme 2011, ISBN 978-1-60406-054-6

In this paper, the removal of methylene blue (MB) from aqueous solution by biosorption onto apricot shellshas been investigated through batch experiments. Apricot shells were chosen as a locally available and abundant waste from fruit juice industry. Methylene blue is common pollutant of waste waters from textile industry. The influence of initial MB concentration on biosorption process has been studied. The experimental data have been analysed using Langmuir and Freundlichisotherm models. The Langmuir model better fits to experimental data, which explain monolayer adsorption. Maximum biosorption capacity is 24,31 mg/g. A comparison of the biosorption capacity of waste apricot shells with biosorption capacities of similar adsorbents previously investigated indicates that apricot shells could be a promising biosorbent for removal of MB from aqueous solution