Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 10

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

Search:
in the keywords:  scaling
help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

A simplified methodology for scaling hydrodynamic data from Lagisza 460 MWesupercritical CFB boiler

100%
Mirek P.
Chemical and Process Engineering
|
2011
|
vol. 32
|
issue 4
245-253
EN
The paper presents the results of model studies on the hydrodynamics of the world's first supercritical circulating fluidized bed boiler Lagisza 460 MWe, carried out on a scale model built in a scale of 1/20 while preserving the full geometrical similarity. To reflect the macroscopic pattern of flow in the boiler's combustion chamber, tests were carried out based on two dimensionless flow dynamic similarity criteria, while maintaining a constant Froude number value between the commercial and the scaled-down units. A mix of polydispersion solids with its fractional composition determined by scaling down the particle size distribution of the boiler's inert material was utilised for the tests using a special scaling function. The obtained results show very good agreement with the results of measurements taken on the Lagisza 460 MWe supercritical CFB boiler.
2
Content available remote

The influence of sampling point on solids suspension density applied in scaling of the hydrodynamics of a supercritical CFB boiler

100%
Mirek P., Ziaja J.
Chemical and Process Engineering
|
2011
|
vol. 32
|
issue 4
391-399
EN
The article presents the results of laboratory tests carried out on a scaling model of the 966MWth fluidised-bed boiler operating in the Lagisza Power Plant, made on a scale of 1:20 while preserving the geometrical similarity. The tests were carried out for scaled-down material taken from different locations on the circulation contour in the state of full boiler loading. To reflect the hydrodynamic conditions prevailing in the combustion chamber, solids with properly selected density and particle size distribution were used. The obtained results have made it possible to determine the location for taking the most representative granular material sample.
3
Content available remote

Scaling diminution by heterogeneous crystallization in a filtration element integrated with membrane distillation module

100%
Gryta M.
Polish Journal of Chemical Technology
|
2009
|
vol. 11
|
issue 2
60-65
EN
Water desalination by membrane distillation is restricted by calcium carbonate precipitation on the membrane surface, what resulted in a progressive decline of the permeate flux. The module rinsing by HCl solution removed this deposit, however, such operation could cause the membrane wettability, associated with lowering of the permeate flux. This phenomenon was inhibited when the membrane modules with prefiltration element, assembled directly at the inlet to module, were used. The salt deposits were formed mainly on the surface of the filtration element (nets area constituted over 10% of the membranes area), what protected the membranes assembled inside the module. The filter efficiency decreased when the deposit layer covered the entire surface of pre-filter element, and after a few hours (period of 10-20 h) the formation of crystallite on the membrane surface was also observed. Therefore, the formed deposit was systematically removed (at every 5 h) from this pre-filter by 3 wt.% HCl solutions. The periodical rinsing of nets by acid did not have a negative influence on the membrane
4
Content available remote

Scaling of flow phenomena in circulating fluidized bed boilers

100%
Mirek P.
Chemical and Process Engineering
|
2011
|
vol. 32
|
issue 2
91-100
EN
The paper presents an overview of scaling models used for determining hydrodynamic parameters of Circulating Fluidized Bed boilers. The governing equations and the corresponding dimensionless numbers are derived and presented for three different approaches to the scaling law of fluidized beds: classical dimensional analysis, differential equations and integrated solutions and experimental correlations. Some results obtained with these equations are presented. Finally, the capabilities and limitations of scaling experiments are discussed.
5
Content available remote

Scaling behavior of earthquakes’ inter-events time series

100%
Shadkhoo S., Ghanbarnejad F., Jafari G., Tabar M.
Open Physics
|
2009
|
vol. 7
|
issue 3
620-623
EN
In this paper, we investigate the statistical and scaling properties of the California earthquakes’ inter-events over a period of the recent 40 years. To detect long-term correlations behavior, we apply detrended fluctuation analysis (DFA), which can systematically detect and overcome nonstationarities in the data set at all time scales. We calculate for various earthquakes with magnitudes larger than a given M. The results indicate that the Hurst exponent decreases with increasing M; characterized by a Hurst exponent, which is given by, H = 0:34 + 1:53/M, indicating that for events with very large magnitudes M, the Hurst exponent decreases to 0:50, which is for independent events.
6
Publication available in full text mode
Content available

The influence of sampling point on solids suspension density applied in scaling of the hydrodynamics of a supercritical CFB boiler

100%
Mirek P., Ziaja J.
Chemical and Process Engineering
|
2011
|
issue 4
7
Publication available in full text mode
Content available

Scaling of flow phenomena in circulating fluidized bed boilers

100%
Mirek P.
Chemical and Process Engineering
|
2011
|
issue 2
8
Publication available in full text mode
Content available

A simplified methodology for scaling hydrodynamic data from Lagisza 460 MWe supercritical CFB boiler

100%
Mirek P.
Chemical and Process Engineering
|
2011
|
issue 4
9
Content available remote

Assessment of Hand Function Through the Coordination of Contact Forces in Manipulation Tasks

88%
Jaric S., Uygur M.
Journal of Human Kinetics
|
2013
|
vol. 36
|
issue 1
5-160
EN
Exploration of force coordination has been one of the most often used approaches in studies of hand function. When holding and manipulating a hand-held object healthy individuals are typically able to highly coordinate the perpendicular (grip force; GF) with the tangential component of the contact force (load force; LF). The purpose of this review is to present the findings of our recent studies of GF-LF coordination. Regarding the mechanical factors affecting GF-LF coordination, our data suggest that both different hand segments and their particular skin areas could have markedly different friction properties. It also appears that the absolute, rather than relative safety margin (i.e., how much the actual GF exceeds the minimum value that prevents slipping) should be a variable of choice when assessing the applied magnitude of GF. The safety margin could also be lower in static than in free holding tasks. Regarding the involved neural factors, the data suggest that the increased frequency, rather than an increased range of a cyclic LF could have a prominent detrimental effect on the GF-LF coordination. Finally, it appears that the given instructions (e.g., 'to hold' vs. 'to pull') can prominently alter GF-LF coordination in otherwise identical manipulation tasks. Conversely, the effects of handedness could be relatively week showing only slight lagging of GF in the non-dominant, but not in the dominant hand. The presented findings reveal important aspects of hand function as seen through GF-LF coordination. Specifically, the use of specific hand areas for grasping, calculation of particular safety margins, the role of LF frequency (but not of LF range) and the effects of given instructions should be all taken into account when conducting future studies of manipulation tasks, standardizing their procedures and designing routine clinical tests of hand function.
10
Publication available in full text mode
Content available

Experimental verification of the scaling laws for CFB boilers of different designs

75%
Mirek P., Klajny M.
Chemical and Process Engineering
|
2016
|
vol. 37
|
issue 2
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.