Spinning the web: New social contacts of Prague’s suburbanites

Suburbanization is one of the most important processes changing the nature of metropolitan regions in Europe’s post-socialist countries. This paper evaluates the importance of social contacts of new suburbanites on local level social cohesion and development. The paper employs examples from empirical research into new suburban communities in the Prague metropolitan region of the Czech Republic. Our results show that both internal and external social ties are developing in such newly built areas, which is important for the well-being of both the neighborhood and the municipality. Internal ties foster the social cohesion of a neighborhood, while external ties encourage development of the whole municipality (e.g., via political participation or informal contacts).     

Preparation of dehydroxylated and delaminated talc: Meta-talc

The roentgen-amorphous delaminated and dehydroxylated phase was prepared applying intensive milling procedure and subsequent thermal treatment of talc. Due to the similarity in properties and in thermal behavior of this material with roentgen-amorphous delaminated and dehydroxylated kaolinite phase, i.e. meta-kaolinite, the name meta-talc was suggested for this material. The properties and the behavior during thermal treatment were investigated using thermal analysis, x-ray diffraction analysis, infrared spectroscopy and scanning electron microscopy. The suggested procedure changes the activation energy of dehydroxylation, the behavior during thermal treatment and the phase composition of the product. The kinetics and thermodynamics of the thermal transition were evaluated using Kissinger equation and Eyering law.     

Internalization and Accumulation in Dendritic Cells of a Small pH‐Activatable Glycomimetic Fluorescent Probe as Revealed by Spectral Detection

DC‐SIGN, an antigen‐uptake receptor in dendritic cells (DCs), has a clear role in the immune response but, conversely, can also facilitate infection by providing entry of pathogens into DCs. The key action in both processes is internalization into acidic endosomes and lysosomes. Molecular probes that bind to DC‐SIGN could thus provide a useful tool to study internalization and constitute potential antagonists against pathogens. So far, only large molecules have been used to directly observe DC‐SIGN‐mediated internalization into DCs by fluorescence visualization. We designed and synthesized an appropriate small glycomimetic probe. Two particular properties of the probe were exploited: activation in a low‐pH environment and an aggregation‐induced spectral shift. Our results indicate that small glycomimetic molecules could compete with antigen/pathogen for binding not only outside but also inside the DC, thus preventing the harmful action of pathogens that are able to intrude into DCs, for example, HIV‐1.     

Simultaneous Enhancement of Fracture Toughness and Unipolar Strain in Pb(Zr,Ti)O3‐ZrO2 Composites Through Composition Adjustment

The influence of second phase zirconia particles on the electrical properties and fracture behavior of various polycrystalline soft Pb(Zr_1?xTi_x)O₃ (PZT) compositions was investigated. PZT composites with yttria‐stabilized tetragonal zirconia particles exhibited enhanced crack resistance in comparison to monolithic compositions, regardless of the PZT composition. The addition of zirconia, however, was found to change the PZT composition through the diffusion of zirconium, resulting in variations in the observed piezoelectric and ferroelectric responses. Through the tailoring of the PZT matrix composition, the large electromechanical response and enhanced fracture toughness could be retained. The variation in both small and large signal properties is contrasted to fracture results and crystal structure changes, as determined by X‐ray diffraction.     

Rare earth chloride and nitrate salts as individual and mixed inhibitors for aluminium alloy 7075-T6 in chloride solution

The aim of the study was to investigate various rare earth salts as corrosion inhibitors of aluminium alloy 7075-T6. Rare earth salts, CeCl₃, LaCl₃, Ce(NO₃)₃ and La(NO₃)₃, were studied, first as individual inhibitors in the concentration range between 0.001 and 0.05?M. Second, the inhibitory effect of mixtures of chloride or nitrate salts was studied at an overall inhibitor concentration of 0.01?M. The corrosion properties of AA7075-T6 in the absence and presence of individual and mixed rare earth salts were investigated using electrochemical potentiodynamic technique in 0.1?M NaCl. The topography, morphology and composition of the inhibited surfaces were recorded. The highest inhibitory effectiveness was exhibited by CeCl₃, followed by mixtures of CeCl₃ and LaCl₃. During immersion for 12?h the corrosion protection remained high. Nitrate rare earth salts showed less protection, both as individual or as mixed inhibitors. Deposits containing both cerium and lanthanum were formed primarily on Cu-based intermetallics.     

Integrated material flow and radioactivity distribution methodology within the calculation tool for evaluation of parameters for decommissioning of nuclear installations

Decommissioning of nuclear facilities becomes an important issue in all areas of nuclear technology, mainly in their energetic applications. Decommissioning process has to be planned in the safe, ecological and economic manner. It determines the requirements on appropriate evaluation of needed technologies, media, amount of solid materials released into the environment, radioactivity of effluents, amount of radioactive waste for disposal, number and exposure of personnel and finally the financial demands. A detailed evaluation of these parameters may be done by analytical calculation approach. This approach models a real process of decommissioning with its individual basic activities. The methodology of integrated material flow and radioactivity distribution within this calculation evaluation tool is applied and implemented to describe the real decommissioning activities and their mutual relations to obtain more accurate outputs.     

Investigation of impact materials around Barringer Meteor Crater by SEM-EDX and micro-PIXE techniques

Impact materials collected at the Barringer Meteor Crater have been characterized by SEM-EDX and micro-PIXE techniques. Fine textural and true elemental images were created. As a main feature silica-bearing shell and an S–Fe–Ni–Cu core could be distinguished. Three different types of S–Fe–Ni–Cu systems were identified such as chalcopyrite, pentlandite and pyrrhotite.     

Effect of substrate on the risk of being washed away by floods for the Groundhoppers Tetrix subulata and Tetrix tenuicornis (Orthoptera: Tetrigidae)

Inundation zones of rivers are risky environments for terrestrial animals because of the regular or irregular occurrence of floods. Although animals in these zones have evolved several strategies to survive floods, behavioural anti‐flooding strategies have seldom been studied but could play an important role in their life history strategies. We previously reported that the groundhopper Tetrix tenuicornis moves to dense vegetation in response to low atmospheric pressure (which may signal rain and flooding) but prefers mossy microhabitats and bare ground under high atmospheric pressure. In the current study, we found that the ability of the semi‐aquatic groundhoppers T. tenuicornis and Tetrix subulata to withstand direct water flow was greater in patches of dense vegetation than in patches of moss or on bare ground. Even a relatively low water velocity led to water transport (presumably passive) of both species, perhaps because they lack arolia or other adhesive devices on their tarsi. This morphological limitation precludes vertical migration on vegetation, which is a common anti‐flooding strategy in insects. Our results suggest that, by moving to dense vegetation in response to drops in atmospheric pressure, groundhoppers may reduce their risk of being washed away by floods.     

Wind forecasts for wind power generation using the Eta model

The goal of this article is to apply the regional atmospheric numerical weather prediction Eta model and describe its performance in validation of the wind forecasts for wind power plants. Wind power generation depends on wind speed. Wind speed is converted into power through characteristic curve of a wind turbine. The forecasting of wind speed and wind power has the same principle.Two sets of Eta model forecasts are made: one with a coarse resolution of 22 km, and another with a nested grid of 3.5 km, centered on the Nasudden power plants, (18.22°E, 57.07°N; 3 m) at island Gotland, Sweden. The coarse resolution forecasts were used for the boundary conditions of the nested runs. Verification is made for the nested grid model, for summers of 1996–1999, with a total number of 19 536 pairs of forecast and observed winds. The Eta model is compared against the wind observed at the nearest surface station and against the wind turbine tower 10 m wind. As a separate effort, the Eta model wind is compared against the wind from tower observations at a number of levels (38, 54, 75 and 96 m).Four common measures of accuracy relative to observations - mean difference (bias), mean absolute difference, root mean square difference and correlation coefficient are evaluated. In addition, scatter plots of the observed and predicted pairs at 10 and 96 m are generated. Average overall results of the Eta model 10 m wind fits to tower observations are: mean difference (bias) of 0.48 m/s, mean absolute difference of 1.14 m/s, root mean square difference of 1.38 m/s, and the correlation coefficient of 0.79. Average values for the upper tower observation levels are the mean difference (bias) of 0.40 m/s; mean absolute difference of 1.46 m/s; root mean square difference of 1.84 m/s and the correlation coefficient of 0.80.     

Investigation of hydrogen generation from sodium borohydride using different cobalt catalysts

Effective Co/Cu, CoB/Cu, and CoBM (M = Mo,Zn,Fe)/Cu catalysts were prepared on the copper surface by a simple electroless deposition method using a morpholine borane as a reducing agent in the glycine solution. The activity of the deposited catalysts was investigated for hydrogen generation from an alkaline sodium borohydride solution. It was determined that these synthesized catalysts demonstrated the catalytic activity for the hydrolysis reaction of NaBH₄. The lowest obtained activation energy (E_A) of the hydrolysis reaction of NaBH₄was 27 kJ mol^?1 for the CoBMo/Cu catalyst. The hydrogen generation rate of 15.30 ml min^?1 was achieved using CoBMo/Cu catalysts at 313 K and it increased ~3.5 times with the increase of temperature to 343 K. The highest hydrogen generation rate obtained by CoBMo/Cu films may be related to the hierarchical cauliflower-shaped 3D structures and the high roughness surface area. Moreover, the CoBMo/Cu catalyst showed an excellent reusability.