PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 7

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available Titania/mesoporous silica nanotubes with efficient photocatalytic properties
Cendrowski K.
Polish Journal of Chemical Technology
|
2018
|
Vol. 20, nr 1
103--108
EN
Ordered nanocrystalline titania-mesoporous silica nanotube structures are synthesized by hydrolysis of the titania precursor inside pours silica shell. Silica coating surrounding carbon nanotubes was further removed by thermal reduction. The proposed method of functionalization silica channels with the titania nanoparticles preclude aggregation of TiO2  nanoparticles. The nanocrystalline silica/titania (mt-SiO2 /TiO2 ) nanotubes were prepared according to the describe method has high specific surface area and possesses excellent photocatalytic properties capable of decomposing phenol and methylene blue in a short time. Since the nanocrystalline TiO2  is produced in the wall of the mesoporous silica tube, phenol or dye molecules can react with TiO2  nanoparticles from both the inside and outside.
2
Content available Carbon nanotubes with controlled length – preparation, characterization and their cytocompatibility effects
Cendrowski K., Jedrzejczak-Silicka M.
Polish Journal of Chemical Technology
|
2018
|
Vol. 20, nr 2
71--79
EN
Multiwalled carbon nanotubes (MWCNTs) have attracted huge attention due to their multifunctionality. Their unique properties allows for covalent and noncovalent modifi cations. The most simple method for functionalization of carbon nanotubes is their decoration with the oxygen containing moieties which can be further simultaneously functionalized for design of new class carriers for targeting and imaging. Here, we present methodology for chopping nanotubes, characterization of MWCNTs, the effect of size on the biocompatibility in culture of L929 mouse fi broblasts using WST-1, LDH and apoptosis assays. The analysis provides the optimal carbon nanotubes length and concentration which can be used for functionalization in order to minimize the effect of the secondary agglomeration when interacting with cells.
3
Content available Preliminary study on the influence of UV-C irradiation on microorganism viability and polyphenol compounds content during winemaking of ‘Regent’ red grape cultivar
Mijowska K., Cendrowski K., Grygorcewicz B., Oszmiański J., Nawrotek P., Ochmian I., Zielińska B.
Polish Journal of Chemical Technology
|
2017
|
Vol. 19, nr 2
130--137
EN
In this study, UV-C light was tested as an alternative method to inactivate microorganisms in the must of ‘Regent’ red grape cultivar. The control sample containing the microorganism diluted in a physiological NaCl solution was prepared to take into consideration different conditions of liquids, such as turbidity and colour. Additionally, the changes in the composition of polyphenol compounds in the ‘Regent’ must after UV-C exposure were evaluated. The viability of yeasts (Saccharomyces cerevisiae) and bacteria (Oenococcus oeni) significantly decreased with time; however, the highest decline was noted after the first hour of exposure. The polyphenol compound content was significantly lower after UV-C treatment and this was mainly the result of anthocyanin decomposition. The total content of flavan-3-ols and hydroxycinnamic acids and derivatives increased after irradiation.
4
Content available remote Mikrostruktura betonów osłonowych na kruszywie magnetytowym w wysokiej temperaturze
Horszczaruk E., Sikora P., Mijowska E., Cendrowski K.
Materiały Budowlane
|
2016
|
nr 8
70--72
PL
W artykule przedstawiono analizę wpływu kruszywa magnetytowego na mikrostrukturę betonów osłonowych w warunkach wysokiej temperatury. Badaniom poddano dwa betony osłonowe wykonane z zastosowaniem kruszywa magnetytowego oraz beton zwykły na kruszywie naturalnym. Próbki wygrzewano w piecu średniotemperaturowym, w temperaturze: 300, 450, 600 i 800 °C. W celu wyjaśnienia zmian w strukturze badanych betonów, próbki poddano badaniu, stosując analizę obrazu SEM oraz metody dyfrakcji rentgenowskiej XRD. Przedstawione badania wykazały, że kruszywo magnetytowe ma wpływ na zmianę mikrostruktury betonu w warunkach wysokiej temperatury.
EN
In this paper it is presented the analize of the effect of magnetite aggregate on the microstructure of shielding concrete exposed to an elevated temperature. Two shielding concretes containing magnetite aggregate and concrete containing normal aggregate have been tested. Samples were exposed to 300, 450, 600 and 800 °C. In order to characterize changes in the microstructure of concretes, samples have been tested with use of scanning electron microscope (SEM) and X-ray diffraction (XRD) techniques. Presented studies have shown that magnetite aggregate has influence on the microstructure of concrete subjected to an elevated temperature.
5
Content available remote Wpływ nowej metody dodawania nanosfer krzemionkowych na właściwości mechaniczne zapraw cementowych
Horszczaruk E., Mijowska E., Cendrowski K., Sikora P.
Cement Wapno Beton
|
2014
|
R. 18/80, nr 5
308--316
PL
W pracy zastosowano nową metodę dodawania nanokrzemionki do cementu w formie zawiesiny w acetonie. Stwierdzono, że metoda ta zapobiega nierównomiernemu rozproszeniu cząstek nanokrzemionki w zaprawie. Równocześnie jednak powoduje ona wzrost powietrza w świeżej zaprawie, co znacznie zmniejsza korzystny wpływ nanokrzemionki na wytrzymałość zapraw. Zastosowanie tej metody w praktyce wymaga więc rozwiązania problemu.
EN
In the paper the new method of nanosilica addition to cement as an suspension in acetone was tested. It was found that this method helps to avoid the non-uniformly dispersed nanosilica particles in mortar. However, simultaneously it caused the air content in the fresh mortars to be increased. Thus the positive influence of nanosilica on mortar strength is significantly lowered. The application of the proposed method in practise needs the solution of the problem of the increase of air content in the fresh mortar.
6
Content available remote Wpływ nanokrzemionki o zróżnicowanej morfologii na właściwości mechaniczne zapraw cementowych
Horszczaruk E., Mijowska E., Cendrowski K., Mijowska S., Sikora P.
Cement Wapno Beton
|
2013
|
R. 18/80, nr 1
24--32
PL
Praca przedstawia wyniki badań wpływu dodatku dwóch rodzajów nano-SiO2: bez porowatej warstewki wokół jądra (n-SiO2) i z tą warstewką (m-SiO2) na wytrzymałość zapraw z cementu portlandzkiego. Uzyskane wyniki potwierdzają, że oba dodatki zwiększają wytrzymałość zapraw na ściskanie i na zginanie. Największą wytrzymałość na zginanie osiągnęły zaprawy z dodatkiem wynoszącym 3% masy cementu, w przypadku obu form krzemionki. Natomiast wytrzymałość na ściskanie rosła wraz ze zwiększającym się dodatkiem n-SiO2 I największą wartość osiągnęła w przypadku 5%. Wzrost wytrzymałości na ściskanie z dodatkiem m-SiO2 był mniejszy i największą wartość osiągnęła zaprawa z 3% dodatkiem.
EN
The work is devoted to study the influence of nanosilica with (m-Si02) and without (n-Si02) mesoporous shell additions on Portland cement mortars mechanical properties. The results have shown that these additions increase the compressive and flexural strength of mortars. The highest flexural strength have the mortars with 3% addition of cement mass of both nanosilica types. However, the compressive strength was increasing with rise of n-Si02 addition and the highest was for 5% content in the mortar. The increase of compressive strength with m-Si02 was lower in comparison with n-Si02, and the highest was for 3% addition.
7
Content available remote Synthesis and characterization of iron-filled multi-walled nanotubes
Jedrzejewska A., Costa S., Cendrowski K., Kalenczuk R. J., Mijowska E.
Materials Science Poland
|
2011
|
Vol. 29, No. 4
299--304
EN
The growth of iron filled multiwalled carbon nanotubes (Fe-MWCNT) using chemical vapour deposition (CVD) has been widely studied. Considering the remarkable magnetic and structural properties of Fe-MWCNT, these materials have been applied in numerous areas. In particular their biomedical application has been explored, where Fe-MWCNT can be used in hyperthermia, acting as a local nano-heater at cellular level. Regarding this aim, the reproducible and highly purified ferromagnetically filled samples of carbon nanotubes are still required. There are several parameters during the synthesis process that influence the properties of the nanotubes. The most favourable temperature of the CNT growth is probably one of the most important issues and its optimisation is crucial. In the current study, the Fe-MWCNT were grown at different temperatures ranging from 650 to 1050 C. Additionally, a comparison between two different CVD systems and two carbon sources are also here presented. The Fe-MWCNT were characterised using diverse techniques regarding the evaluation of their morphology, filling ratio, and purity. Observations showed a strong influence of the growth temperature on the morphology and properties of the Fe-MWCNT. The samples characterisation was performed using Raman spectroscopy, thermogravimetric analysis (TGA), X ray diffraction (XRD), and transmission electron microscopy analysis (TEM).
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.