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

help Sort By:

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

Neutron Radiography Studies of Water Self-Diffusion in Porous Medium

100%
Milczarek J., Fijał-Kirejczyk I., Chojnowski M., Żołądek J.
Acta Physica Polonica A
|
2008
|
vol. 113
|
issue 4
1237-1244
EN
The results of neutron radiography studies on macroscopic self-diffusion of water confined within rigid porous material reveal the substantial reduction in diffusion constant in comparison to the diffusion in large volume. The studies performed in the 30-50°C temperature range on fired clay brick of 30% porosity show decrease in diffusion constant to approximately 17% of its value for free space and the Archie exponent is 1.4. The Arrhenius law was confirmed and the activation energy was found of the same value as in the water bulk.
2
Publication available in full text mode
Content available

Determination of Capillary Motion of Water in Bricks Using Neutron Radiography

100%
Czachor A., El-Ghany El-Abd A., Milczarek J.
Acta Physica Polonica A
|
2002
|
vol. 102
|
issue 2
245-252
EN
Vertical migration of water in several porous materials has been directly observed and recorded with the recently installed neutron and gamma radiography facility at the MARIA reactor of Institute of Atomic Energy, Świerk. The density profiles of water in samples were obtained from the optical density of digitised images. A simple model (representing the porous material as the collection of capillary tubes of various radii) has been introduced to describe the liquid transport in porous materials in terms of capillary motion. The equation for viscous movement of water in porous material in presence of the gravitation is proposed. A good agreement of the calculated density profiles for vertical water migration with the data collected for siliceous bricks suggests that the thinnest capillary tubes determine the upper edge of the water density profile.
3
Content available remote

The Effect of Sodium Chloride on the Process of Drying of Porous Media

100%
Fijał-Kirejczyk I., Milczarek J., Jurkowski Z., Żołądek J.
Acta Physica Polonica A
|
2013
|
vol. 124
|
issue 6
1025-1028
EN
The high temperature drying process of corundum cylinders partially saturated with aqueous solutions of sodium chloride was investigated with neutron imaging technique accompanied with mass and temperature measurements. The statistical analysis of neutron images was applied in order to quantify the time evolution of the process. The substantial slowing down of drying with increasing salt concentration was found. This effect was attributed to increase of viscosity of the solution with increasing salt content as well as to the formation of an outer layer of NaCl on the sample surface.
4
Content available remote

Application of Neutron Refraction for Characterization and Optimization of High-Damping Iron-Based Alloys

88%
Udovenko V., Polyakova N., Chudakov I., Milczarek J., Mikke K.
|
|
vol. 96
|
issue 2
303-306
EN
High-damping alloys with the magnetomechanical damping mechanism, based on the Fe-Cr system, have been studied. It has been shown that the direct investigation of the magnetic domain structure in the bulk materials using the neutron refraction method allows one to obtain important quantitative information concerning the formation of the high-damping state. The dependence of the damping capacity on the average magnetic domain size was found to possess a sharp maximum, thus revealing a range of the optimal domain sizes. The results obtained are important for the development of the technology of high-damping materials.
5
Content available remote

Transient Thermal Phenomena during Spontaneous Water Migration in Zeolite Beds

88%
Żołądek-Nowak J., Milczarek J., Fijał-Kirejczyk I., Żołądek J., Jurkowski Z.
Acta Physica Polonica A
|
2012
|
vol. 122
|
issue 2
415-418
EN
The changes in local temperature occurring during spontaneous imbibition of columnar samples of dry natural zeolite with water were studied. The temperature pulses of 20-250 s duration and 3-40°C amplitude were registered and correlated with the wetting front motion observed with neutron radiography. The amplitude of the pulses was shown to increase with increasing ambient temperature. The broadening of the temperature pulse with increasing distance from the water supplied end of the samples was observed. The amplitude and the pulse width were found to depend substantially on the drying temperature of the material. The observed effect was attributed to the heat of immersion released in the sample at the moving wetting front.
6
Content available remote

Effect of Gravitation on Water Migration in Granular Media

88%
Milczarek J., Fijał-Kirejczyk I., Żołądek J., Chojnowski M., Kowalczyk G.
Acta Physica Polonica A
|
2008
|
vol. 113
|
issue 4
1245-1254
EN
The results of the experiments on water migration in unsaturated granular media performed with dynamic neutron radiography technique are presented. It was found that the porosity of the medium did not determine the kinetics of the process in a marked way. The influence of gravity was found to be considerable for media like coarse sand and gravel, consisting of large grains. No effect of gravitation on the water migration in clay beds was observed. The results are discussed in terms of the classical Washburn-Bosanquet theory of adhesion driven motion of the liquid in a straight circular capillary under gravity. It was found that this theory provides only qualitative description of the water migration within granular media, and the viscous dissipation effects are greatly underestimated.
7
Content available remote

Materials Research on Archaeological Objects Using PIXE and Other Non-Invasive Techniques

76%
Miśta E., Stonert A., Korman A., Milczarek J., Fijał-Kirejczyk I., Kalbarczyk P., Wiśniewska A.
Acta Physica Polonica A
|
2015
|
vol. 128
|
issue 5
815-817
EN
An interdisciplinary study of metallic objects from selected archaeological sites in Poland was performed. The aim of the project was to obtain information about the chemical composition and structural changes of the objects. Furthermore, the research results provided information about the technological process which was used to manufacture the artifacts. The materials research had a non- and micro-invasive character which is very important in this type of investigation. The main experimental tools were particle-induced X-ray emission supplemented with nuclear reaction thermal neutron (white beam) radiography, scanning electron microscopy with X-ray energy dispersive analysis, and laser ablation inductively coupled plasma mass spectrometry techniques. The results show that the artifacts were made by a secondary smelting process used in local metallurgy manufactures.
8
Content available remote

Application of Statistical Image Analysis in Quantification of Neutron Radiography Images of Drying

76%
Fijał-Kirejczyk I., Milczarek J., Żołądek-Nowak J., de Beer F., Radebe M., Nothnagel G.
Acta Physica Polonica A
|
2012
|
vol. 122
|
issue 2
410-414
EN
The statistical approach to the thermal neutron radiography picture analysis is applied to evaluation of the experimental results obtained for drying of rectangular and cylindrical samples of granulated and rigid porous materials. We have shown that the time dependence of the standard deviation of image brightness reflects the appearance and motion of the drying front observed during second period of the drying process. The results are discussed within a simple two-region model of the drying sample image.
9
Content available remote

Properties of Neutron Doped Multicrystalline Silicon for Solar Cells

76%
Pochrybniak C., Pytel K., Milczarek J., Jaroszewicz J., Lipiński M., Piotrowski T., Kansy J.
Acta Physica Polonica A
|
2008
|
vol. 113
|
issue 4
1255-1265
EN
The technology of neutron transmutation doping of silicon wafers in MARIA nuclear research reactor is described. The studies of the radiation defects performed with positron annihilation confirmed that divacancies dominate in the irradiated material. Thermal treatment of irradiated silicon at 700-1000°C produces void-phosphorus complexes and void aggregates. The resistivity of the samples produced by neutron transmutation doping was found to be uniform within 2.5% limits. The severe reduction of the minority carrier lifetime in irradiated samples was confirmed.
10
Content available remote

Drying Kinetics of Particulate Corundum Layers

76%
Cmiel K., Milczarek J., Bam L., Fijał-Kirejczyk I., Jurkowski Z., Żołądek J.
Acta Physica Polonica A
|
2013
|
vol. 124
|
issue 6
1029-1033
EN
The results of studies on drying of layers of particulate corundum performed with digital neutron radiography are presented. The statistical analysis of images was employed to reveal main features of the drying process. It is shown that the first period of drying proceeds within the whole body of the sample. Marked signatures of the end of first period of drying were found for sample mass, temperature, average image brightness as well as standard deviation of brightness time evolutions for the system composed of fine grains. The chaotic nature of this period is delineated by a distinct maximum in the standard deviation of sample image brightness. The presence of the drying front moving from the open surface to the sample bottom is proven to be an attribute of the advanced drying period.
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.