Balázs Szabó

Patterns of Socioeconomic Segregation in the Capital Cities of Fast-Track Reforming Postsocialist Countries

Socioeconomic disparities have been rising on both sides of the Atlantic for the last forty years. This study illuminates the relationship among economic inequality, other contextual and institutional factors, and socioeconomic intraurban segregation in Eastern Europe. We draw our empirical evidence from the capital cities of so-called fast-track reforming postsocialist countries: Estonia, Hungary, Lithuania, Poland, and the Czech Republic. The analysis consists of two stages. First, we use the traditional indexes of segregation to assess the global levels of socioeconomic segregation in the case cities. Second, we investigate the global patterns and local geographies of socioeconomic residential intermixing and introduce a typology of neighborhoods based on the socio-occupational composition of their residential tracts. Despite rapidly growing income inequality, the levels of socioeconomic segregation in the postsocialist city are either low or very low. The scale of segregation differs between the cities and the patterns of residential intermixing in the large cities of central and Eastern Europe are fundamentally different from those found in the Baltic states. The results lead to two important conclusions. One is that the link between socioeconomic distance and spatial distance in postsocialist cities is moderately sensitive to the level of economic inequality and to other contributory factors. The other key finding is that inertia effects have offset the immediate catalyzing effect of economic liberalization, globalization, and growing socioeconomic inequality on the patterns of segregation, at least in the first decade after the collapse of socialism.

Effects of grain shape on packing and dilatancy of sheared granular materials

A granular material exposed to shear shows a variety of unique phenomena: Reynolds dilatancy, positional order and orientational order effects may compete in the shear zone. We study granular packing consisting of macroscopic prolate, oblate and spherical grains and compare their behaviour. X-ray tomography is used to determine the particle positions and orientations in a cylindrical split bottom shear cell. Packing densities and the arrangements of individual particles in the shear zone are evaluated. For anisometric particles, we observe the competition of two opposite effects. On the one hand, the sheared granules are dilated, on the other hand the particles reorient and align with respect to the streamlines. Even though aligned cylinders in principle may achieve higher packing densities, this alignment compensates for the effect of dilatancy only partially. The complex rearrangements lead to a depression of the surface above the well oriented region while neighbouring parts still show the effect of dilation in the form of heaps. For grains with isotropic shapes, the surface remains rather flat. Perfect monodisperse spheres crystallize in the shear zone, whereby positional order partially overcompensates dilatancy effects. However, even slight deviations from the ideal monodisperse sphere shape inhibit crystallization.

Packing, alignment and flow of shape-anisotropic grains in a 3D silo experiment

Granular material flowing through bottlenecks like the openings of silos tend to clog and to inhibit further flow. We study this phenomenon in a three-dimensional hopper for spherical and shape-anisotropic particles by means of X-ray tomography. The X-ray tomograms provide information on the bulk of the granular filling, and allows to determine the particle positions and orientations inside the silo. In addition, it allows to calculate local packing densities in different parts of the container. We find that in the flowing zone of the silo particles show a preferred orientation and thereby a higher order. Similarly to simple shear flows, the average orientation of the particles is not parallel to the streamlines but encloses a certain angle with it. In most parts of the hopper, the angular distribution of the particles did not reach the one corresponding to stationary shear flow, thus the average orientation angle in the hopper deviates more from the streamlines than in stationary shear flows. In the flowing parts of the silo shear induced dilation is observed, which is more pronounced for elongated grains than for nearly spherical particles. The clogged state is characterized by a dome, i. e. the geometry of the layer of grains blocking the outflow. The shape of the dome depends on the particle shape.

Evolution of shear zones in granular materials

The evolution of wide shear zones or shear bands was investigated experimentally and numerically for quasistatic dry granular flows in split bottom shear cells. We compare the behavior of materials consisting of beads, irregular grains, such as sand, and elongated particles. Shearing an initially random sample, the zone width was found to significantly decrease in the first stage of the process. The characteristic shear strain associated with this decrease is about unity and it is systematically increasing with shape anisotropy, i.e., when the grain shape changes from spherical to irregular (e.g., sand) and becomes elongated (pegs). The strongly decreasing tendency of the zone width is followed by a slight increase which is more pronounced for rodlike particles than for grains with smaller shape anisotropy (beads or irregular particles). The evolution of the zone width is connected to shear-induced packing density change and for nonspherical particles it also involves grain reorientation effects. The final zone width is significantly smaller for irregular grains than for spherical beads.

Heaping, secondary flows and broken symmetry in flows of elongated granular particles

In this paper we report experiments where we shear granular rods in split-bottom geometries, and find that a significant heap of height of least 40% of the filling height can form at the particle surface. We show that heaping is caused by a significant secondary flow, absent for spherical particles. Flow reversal transiently reverses the secondary flow, leading to a quick collapse and slower regeneration of the heap. We present a symmetry argument and experimental data that show that the generation of the secondary flow is driven by a misalignment of the mean particle orientation with the streamlines of the flow. This general mechanism is expected to be important in all flows of sufficiently anisometric grains.

Flow of anisometric particles in a quasi-2D hopper

The stationary flow field in a quasi-two-dimensional hopper is investigated experimentally. The behavior of materials consisting of beads and elongated particles with different aspect ratio is compared. We show, that while the vertical velocity in the flowing region can be fitted with a Gaussian function for beads, in the case of elongated grains the flowing channel is narrower and is bordered with sharper velocity gradient. For this case, we quantify deviations from the Gaussian velocity profile. Relative velocity fluctuations are considerably larger and slower for elongated grains.

Persistence or Change: Divergent Trajectories of Large Housing Estates in Budapest, Hungary

In post-socialist cities of Central and Eastern Europe, large housing estates became dominant features of post-war housing development. Unlike in Western Europe, these neighbourhoods were not developed for immigrants and the poorest segment of society. Instead, they provided homes for lower middle class and working class families with stable incomes. After the change of regime, however, these neighbourhoods experienced different development trajectories not only on the international but also on national and city levels. With regard to contemporary developments of housing estates, Budapest provides a typical post-socialist case where housing estates are continuously re-evaluated by the people and the market, while socialist legacies leave their imprints on the actual socio-economic developments. This chapter focuses on the development of large housing estates in Budapest and in Hungary before and after the transition. Today, one-fifth of the Hungarian population and one-third of Budapest’s residents live in housing estate neighbourhoods. The main objectives of the study are to display the spatial distribution of different generations of housing estates at the national and city level with special emphasis on their physical and social characteristics. The chapter also sheds light on the consequences of the post-socialist transition on the recent developments of housing estates in Budapest. After almost three decades of transition, debates about housing estates and their future possibilities are still relevant in Hungary and Budapest, because some of these neighbourhoods are experiencing a renaissance in the housing market, attracting younger and better off strata, whereas others show symptoms of socio-economic decline.

Shear alignment and orientational order of macroscopic rodlike grains

This contribution establishes a link between very different soft matter systems that exhibit orientational order. Granular matter research has been focused so far mainly on ensembles of spherical or irregularly shaped grains. Recently, several studies of anisometric particles have been reported, but still, many phenomena in such materials are little understood. Quantitative experiments are scarce. We report shear experiments with macroscopic shape-anisotropic particles [Borzsonyi et al., Phys. Rev. Lett., 108, 228302 (2012)] and discuss induced orientational order and alignment. Optical observations of the top layer are accompanied by X-ray computed tomography [Wegner et al., Soft Matter, in press (2012)], where positions and orientations of each individual grain in the bulk can be resolved. We establish quantitative relations between shear alignment and aspect ratio. The induced orientational order influences local packing and other macroscopic properties like the shear resistance. A comparison is drawn with molecular liquid crystals (LC). Many observations are qualitatively and even quantitatively comparable to the well-understood nematic phase of rodlike molecules, even though the types of interactions are completely different.

A kreatív gazdaság földrajzi jellemzői Magyarországon

As a consequence of the shift from the Fordist production system to the post-Fordist economic structures, the cities and metropolitan regions have acquired an ever growing importance and became the centres of economic and social development of countries and regions. Nowadays creativity, knowledge and innovation are broadly recognised as the essential ingredients of economic success in the advanced capitalist world. International experiences show that the creative and knowledge-intensive industries are increasingly seen as the most important factors of international and domestic competitiveness of cities. Concerning the future development of metropolitan regions and urban areas it might be decisive how these city-regions are able to attract and integrate firms and manpower of the creative economy. According to the growing importance of the creative economy, after a short theoretical and methodological introduction the paper analyses the position of creative knowledge sector within the Hungarian economy with special emphasis on its spatial distribution. The role of positions of cities within the settlement network and urban hierarchy, current development trends and impacts of relevant urban development policies are also highlighted. According to recent statistical data available on the municipal level we can conclude that in the period between 1999 and 2007 several remarkable positive changes took place in the creative knowledge sector not only in Hungary, but also in Budapest and a few larger cities in the country. The Budapest Metropolitan Region is the economically most advanced area of the country, and since the change of the political system the capital city managed to keep its leading position in the economic development and modernisation of the country in most respects. The weight of Budapest is disproportionately large in terms of the number and ratio of creative and knowledge intensive firms, as well as regarding the number of employees of these industries and the revenues generated by these sectors. More than 40 percent of the firms operating in the sector, half of the employees and more than 60 percent of the revenues originate from the metropolitan region of Budapest. It must be underlined that following the turn of the millennium the weight of Budapest within the creative knowledge sector of Hungary steadily increased. The strengthening position of Budapest within Hungary in the creative economy is stemming from its traditions, well-educated workforce, highly developed cultural institutions, and widening international (partly global) functions as a decision making centre. The development of creative and knowledge intensive industries in provincial cities is somewhat lagging behind that of the capital city, but their gradual catching-up is indicative of positive shifts and promising for the future. The spatial distribution of the creative workforce in Hungary can be best explained by the urban hierarchy, and the relative location to Budapest. In addition to Budapest, the major university and cultural centres of the country (Debrecen, Szeged, Pecs, etc.) play a decisive role with regard to the development of a creative economy. Due to the transformation in the last twenty years, Hungarian cities have been integrated successfully into the European urban network, although there were serious economic difficulties during the global economic crisis in 2008–2009. At present the emergence of the creative knowledge sector is in an incipient stage in Hungary. However, the position of cities acting vigorously within the creative economy is advantageous and competitive.