454 research outputs found
Urban Agglomerations in the Regional Development: Theoretical, Methodological and Applied Aspects
The article focuses on the analysis of the major process of modern socio-economic development, such as the functioning of urban agglomerations. A short background of the economic literature on this phenomenon is given. There are the traditional (the concentration of urban types of activities, the grouping of urban settlements by the intensive production and labour communications) and modern (cluster theories, theories of network society) conceptions. Two methodological principles of studying the agglomeration are emphasized: the principle of the unity of the spatial concentration of economic activity and the principle of compact living of the population. The positive and negative effects of agglomeration in the economic and social spheres are studied. Therefore, it is concluded that the agglomeration is helpful in the case when it brings the agglomerative economy (the positive bene ts from it exceed the additional costs). A methodology for examination the urban agglomeration and its role in the regional development is offered. The approbation of this methodology on the example of Chelyabinsk and Chelyabinsk region has allowed to carry out the comparative analysis of the regional centre and the whole region by the main socio-economic indexes under static and dynamic conditions, to draw the conclusions on a position of the city and the region based on such socio-economic indexes as an average monthly nominal accrued wage, the cost of fixed assets, the investments into fixed capital, new housing supply, a retail turnover, the volume of self-produced shipped goods, the works and services performed in the region. In the study, the analysis of a launching site of the Chelyabinsk agglomeration is carried out. It has revealed the following main characteristics of the core of the agglomeration in Chelyabinsk (structure feature, population, level of centralization of the core) as well as the Chelyabinsk agglomeration in general (coefficient of agglomeration, index of agglomeration, coefficient of the development of the population, growth rates of agglomeration). The analysis of the internal environment of the agglomeration has shown that the industry of the majority of the cities-satellites is unprofitable, the space of the urban agglomeration is very heterogeneous. The research proves that the creation of the agglomeration will allow to solve the problems of the production diversification at the territory, to perform the effective land use, to optimize transport and housing-and-municipal infrastructure
A discrete particle simulation study on the influence of restitution coefficient on spout fluidized bed dynamics
In this paper the influence of the normal restitution coefficient on the bed dynamics\ud
during different flow regimes was studied using the discrete element model. The three flow\ud
regimes comprise the intermediate/spout-fluidization, spouting-with-aeration regime and the jetin-\ud
fluidized-bed. It is shown that with increase of the restitution coefficient the average bed\ud
height decreases for all flow regime cases. To study the influence of the granule impact velocity\ud
and the liquid film on the wall surface the free-fall experiments in the velocity range of 0.5-\ud
4.5 m/s were performed with spherical γ-Al2O3 granules. During the free-fall tests, the impact\ud
angle from 0° to 80° and the viscosity of thin liquid film in the range of 1-300 mPa·s were\ud
varied
Regional social infrastructure management in the system of tools used for improving the quality of life for regional population
This paper analyzes the processes in the social sphere and the performance of operating the social infrastructure to improve the population’s quality of life in the Russian regions. Particular attention has been paid to the role of organizational and administrative components, which include the regulation of social infrastructure institutions, planning, and programming that affect the performance of infrastructure facilities utilization. The goal of this study was to evaluate the effectiveness of social infrastructure management through the congruence of immediate results (dynamics of indicators for social services) and final results (parameters of the population’s quality of life). The working hypothesis of the study was a breach of infrasystemic principle in the infrastructural support for improving the population’s quality of life in the constituent entities of the Russian Federation because of the insufficient effectiveness of public administration. The work on this paper involved using a set of methodological approaches, such as structured, factorial, systemic, and evolutionary approaches, to substantiate the conceptual framework, prepare the method-based approaches, and determine the impact made by the changes in the parameters of social infrastructure facilities on provided services and shifts in the indicators of the population’s quality of life. The paper proposes a method-based approach to quantifying the effectiveness of organizational and administrative components by using the diagnostics of sufficiency in the implementation of infrasystemic principle for the operation of social infrastructure based on elasticity coefficients. The proposed approach and analytical data obtained in the areas, such as health care, education, trade, housing & utilities, culture & sport, allowed ranking the regions of the Ural Federal District and identifying the areas of insufficient effectiveness in the organizational and administrative mechanism used for improving the population’s quality of life as the basis for developing practical recommendations for the executive branch of constituent entities of the Russian Federation and adjustment of socioeconomic policies
Effect of the liquid layer on the impact behaviour of particles
During a spray granulation process the moisture loading in fluidized beds has a great influence on\ud
the inter-particle collision properties and hence on the flow behaviour. To study the influence of the\ud
liquid layer as well as granule impact velocity on the impact behaviour free-fall experiments were\ud
performed. During these experiments the g-Al2O3 granules were dropped from a predefined height\ud
onto a liquid layer on the flat steel wall and the velocity-time curves were obtained using highspeed\ud
video recording. The height of the liquid layer was varied from 50 mm to 1 mm. Moreover,\ud
the tests were performed at different velocities and viscosities of liquid layer in the range of 1-300\ud
mPa∙s. Both distilled water and water solutions of hydroxypropyl methylcellulose with different\ud
concentrations (3, 6, 10 mass-%) were used.\ud
The obtained restitution coefficients were compared with the experiments performed without liquid\ud
film on the surface. For a granule impacted on a liquid film on the wall, the increase of liquid\ud
viscosity decreases the restitution coefficient and thickness of liquid layer at which the granule\ud
sticks. In the examined velocity range, with decreasing impact velocity the restitution coefficient\ud
greatly decreases. To explain the obtained effects the force and energy balances for a particle\ud
impacted on a liquid layer on the wall were derived. Both contributions to energy absorption\ud
(granule-liquid layer and granule-wall contacts) have been taken into consideratio
Structural Evidence for a Copper-Bound Carbonate Intermediate in the Peroxidase and Dismutase Activities of Superoxide Dismutase
Copper-zinc superoxide dismutase (SOD) is of fundamental importance to our understanding of oxidative damage. Its primary function is catalysing the dismutation of superoxide to O2 and H2O2. SOD also reacts with H2O2, leading to the formation of a strong copper-bound oxidant species that can either inactivate the enzyme or oxidise other substrates. In the presence of bicarbonate (or CO2) and H2O2, this peroxidase activity is enhanced and produces the carbonate radical. This freely diffusible reactive oxygen species is proposed as the agent for oxidation of large substrates that are too bulky to enter the active site. Here, we provide direct structural evidence, from a 2.15 Å resolution crystal structure, of (bi)carbonate captured at the active site of reduced SOD, consistent with the view that a bound carbonate intermediate could be formed, producing a diffusible carbonate radical upon reoxidation of copper. The bound carbonate blocks direct access of substrates to Cu(I), suggesting that an adjunct to the accepted mechanism of SOD catalysed dismutation of superoxide operates, with Cu(I) oxidation by superoxide being driven via a proton-coupled electron transfer mechanism involving the bound carbonate rather than the solvent. Carbonate is captured in a different site when SOD is oxidised, being located in the active site channel adjacent to the catalytically important Arg143. This is the probable route of diffusion from the active site following reoxidation of the copper. In this position, the carbonate is poised for re-entry into the active site and binding to the reduced copper. © 2012 Strange et al
DEM simulations of particle dynamics in a spheronization process to describe the pelletization mechanisms
Spheronization is an important process to produce pharmaceutical pellets with a narrow particle size distribution and a homogeneous outer particle surface. Thereby, cylindrical extrudates are rounded by different pelletization mechanisms [1]. These mechanisms are highly dependent on the particle dynamics in the spheronizer. Discrete Element Method simulations of the particle motions in a spheronizer were performed to study the particle dynamics. The elastic-plastic contact model used in the simulations was calibrated by experiments with spheronized pellets. The influence of different process conditions and particle properties on the particle kinematics and interactions was analyzed. Also a comparison of the simulation results with PIV measurementswas performed
Cool spots on the surface of the active giant PZ Mon
Based on the multiband (BVRIJHKL) photometric observations of the active red
giant PZ Mon performed for the first time in the winter season of 2017-2018, we
have determined the main characteristics of the spotted stellar surface in a
parametric three-spot model. The unspotted surface temperature is Teff=4730 K,
the temperature of the cool spots is Tspot=3500 K, their relative area is about
41%, and the temperature of the warm spots is Twarm=4500 K with a maximum
relative area up to 20%. The distribution of spots over the stellar surface has
been modeled. The warm spots have been found to be distributed at various
longitudes in the hemisphere on the side of the secondary component and are
most likely a result of its influence.Comment: 5 pages, 7 figure
A faulty interaction between SOD1 and hCCS in neurodegenerative disease
A proportion of Amyotrophic lateral sclerosis (ALS) cases result from impaired mutant superoxide dismutase-1 (SOD1) maturation. The copper chaperone for SOD1 (hCCS) forms a transient complex with SOD1 and catalyses the final stages of its maturation. We find that a neurodegenerative disease-associated hCCS mutation abrogates the interaction with SOD1 by inhibiting hCCS zinc binding. Analogously, SOD1 zinc loss has a detrimental effect on the formation, structure and disassociation of the hCCS-SOD1 heterodimer. This suggests that hCCS functionality is impaired by ALS mutations that reduce SOD1 zinc affinity. Furthermore, stabilization of wild-type SOD1 by chemical modification including cisplatination, inhibits complex formation. We hypothesize that drug molecules designed to stabilize ALS SOD1 mutants that also target the wild-type form will lead to characteristics common in SOD1 knock-outs. Our work demonstrates the applicability of chromatographic SAXS when studying biomolecules predisposed to aggregation or dissociation; attributes frequently reported for complexes involved in neurodegenerative disease
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