Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "Structural properties" wg kryterium: Temat

  Lista filtrów
Wyrównaj
Wyświetlanie 1-25 z 97
Tytuł:
A computational approach to structural properties of glycoside hydrolase family 4 from bacteria
Autorzy:
Craciun, Dana
Vlad-Oros, Beatrice
Filimon, Nicoleta
Ostafe, Vasile
Isvoran, Adriana
Powiązania:
https://bibliotekanauki.pl/articles/1039444.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
glycosidases
structural properties
specific interactions
Opis:
Structural bioinformatics approaches applied to the alpha- and beta-glycosidases from the GH4 enzyme family reveal that, despite low sequence identity, these enzymes possess quite similar global structural characteristics reflecting a common reaction mechanism. Locally, there are a few distinctive structural characteristics of GH4 alpha- and beta-glycosidases, namely, surface cavities with different geometric characteristics and two regions with highly dissimilar structural organizations and distinct physicochemical properties in the alpha- and beta-glucosidases from Thermotoga maritima. We suggest that these structurally dissimilar regions may be involved in specific protein-protein interactions and this hypothesis is sustained by the predicted distinct functional partners of the investigated proteins. Also, we predict that alpha- and beta-glycosidases from the GH4 enzyme family interact with difenoconazole, a fungicide, but there are different features of these interactions especially concerning the identified structurally distinct regions of the investigated proteins.
Źródło:
Acta Biochimica Polonica; 2013, 60, 4; 553-564
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural characteristics of thermosensitive chitosan glutaminate hydrogels
Autorzy:
Modrzejewska, Zofia
Nawrotek, Katarzyna
Zarzycki, R
Douglas, Timothz
Powiązania:
https://bibliotekanauki.pl/articles/1035319.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Tematy:
chitosan
hydrogel
natural polymer
structural properties
Opis:
Hydrogels that possess the ability of gelling in response to changes in the local environment, such as pH or temperature, have been examined extensively recently. In this paper the properties of thermosensitive chitosan hydrogels prepared with the use of chitosan glutaminate and -glycerophosphate are presented. The sol/gel transition point was determined based on the rheological properties. The structure of gels was observed under the Scanning Electron Microscopy (SEM) and was investigated by thermogravimetric (TG) and differential themogravimetric (DTG) analy¬sis and infrared (IR) spectroscopy. The crystallinity of gel structure was determined by X-ray Diffraction analysis (XRD).
Źródło:
Progress on Chemistry and Application of Chitin and its Derivatives; 2013, 18, 18; 93-105
1896-5644
Pojawia się w:
Progress on Chemistry and Application of Chitin and its Derivatives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural and optical properties of nanostructured bismuth oxide
Autorzy:
Ali, R. S.
Powiązania:
https://bibliotekanauki.pl/articles/412556.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
thin films’ bismuth oxide
optical properties
structural properties
Opis:
Thin films of bismuth oxide have been prepared utilizing vacuum evaporation. XRD anyalysis reveal that all the films were tetragonal polycrystalline structure with a preferred orientation along (002) plane. SEM images indicate that the grain size fall in the category of nanosize. AFM results assure that the nanonstructure behavior of thin films. Optical studies show that these films have a direct transition with optical energy gap equal to 2.5 eV.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 15; 64-72
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Advanced biocomposites based on silica and lignin precursors
Autorzy:
Klapiszewski, Ł.
Nowacka, M.
Szwarc-Rzepka, K.
Jesionowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/110719.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
biocomposites
silica
lignin
physicochemical and structural properties
Opis:
A new method is proposed for obtaining biocomposites based on a combination of silica and lignin precursors. Amorphous silica was produced by two methods: one based on hydrolysis and condensation of tetraethoxysilane (sol–gel method) and the other involving precipitation in a polar medium. Additionally, the commercial silica known under the name of Syloid®244 was used. The silica surface was modified to ensure better affinity of the support to activated lignin. The biocomposites obtained were carefully characterised by determination of their physicochemical and dispersive–morphological properties. Electrokinetic stability of the biocomposites was evaluated on the basis of zeta potential dependence on pH. Thermal stability of the biocomposites and their porous structure parameters (surface area, pore diameter and pore volume) were established. The results indicate that silica/lignin biocomposites are much promising for application in many areas of science and industry.
Źródło:
Physicochemical Problems of Mineral Processing; 2013, 49, 2; 497-509
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on quantifying the hydrophilicity of leached coals by FTIR spectroscopy
Autorzy:
Wang, J.
He, Y.
Yang, Y.
Xie, W.
Ling, X.
Powiązania:
https://bibliotekanauki.pl/articles/110191.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
chemical-structural properties
macerals
hydrophilicity
functional group
Opis:
Surface properties play important roles in characterization of structural parameters and the hydrophilicity index. Accurate analysis of the macerals rather than the average properties of the macerals and minerals are crucial for these parameters and indexes. In order to improve the accuracy of analyzing coal surface property, HF/HCl acid leaching was applied to eliminate the interference of minerals. FTIR was used to characterize the differences in surface chemical composition between raw and processed coal. Moreover, each functional group was analyzed quantitatively. Based on these quantitative data, the structural parameters and hydrophilicity indexes were calculated. From the results of FTIR, the peaks of mineral cover up the types of the organic peaks, such as -COOH and aromatic CH stretching. In addition, they decrease the intensity of the peak such as C=C and aromatics CHx out-of-plane deformation in the spectra of raw coals. However, it provided the accurate types and contents of organic functional groups of the macerals after acid leaching. The structural parameter results indicate that the values cannot reflect the coal ranks through the surface properties of raw coals while they show a good relationship with the degree of coalification in the analysis of processed coals. Besides, the hydrophilicity indexes are verified by the natural floatability of coal macerals of the processed coals. It is also found that the processed lignite coal cannot be floated despite elimination of the hydrophilic minerals. The main reason of hard-to-float property of lignite coal lies in a strong hydrophilicity of macerals.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 1; 227-239
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption behavior of Zn(II) onto natural minerals in wastewater. A comparative study of bentonite and kaolinite
Autorzy:
Chai, W.
Huang, Y.
Su, S.
Han, G.
Liu, J.
Cao, Y.
Powiązania:
https://bibliotekanauki.pl/articles/109926.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
adsorption
Zn(II)
wastewater
clay minerals
structural properties
Opis:
In order to remove the harmful metal ions in lead-zinc mineral processing wastewater, two natural clay minerals (bentonite and kaolin) were used as adsorbents and Zn(II) ions were the emphasis in this work. The adsorption behaviors including kinetics and isotherms were investigated by batch experiments. In addition, the adsorption mechanisms were studied by means of zeta potential testing, optical microscope and XRD analysis. The results show that the adsorption process can be best described as the pseudo-second order kinetic model. The adsorption equilibrium data of bentonite and kaolinite can be respectively fitted best by Langmuir and Freundlich models. Thermodynamic studies display that the adsorption of Zn(II) onto clays is non-spontaneous and endothermic. The maximum capacity of Zn(II) adsorbed on bentonite and kaolinite respectively reaches to 79.2 mg·g-1 and 6.35 mg·g-1 at 25 °C. The structural differences of bentonite and kaolinite result in the differences in adsorption behavior and mechanism. The interaction mechanisms of Zn(II) with bentonite and kaolinite involve electrostatic attraction, cation exchange, surface complex and precipitation. Bentonite as adsorbent has the potential to remove Zn2+ better than kaolinite.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 1; 264-278
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of molarity on the structural and optical properties of ZnO thin films deposit by CSP
Autorzy:
Habubi, Nadir F.
Abood, Ziad M.
Algamel, Ahmed N.
Powiązania:
https://bibliotekanauki.pl/articles/1193915.pdf
Data publikacji:
2015
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Urbach energy
ZnO
ZnO thin films
optical properties
structural properties
Opis:
ZnO thin films have been prepared by chemical spray pyrolysis technique CSP). XRD pattern reveals that the preferred orientation was varied with concentration, topography analysis was done by AFM micrograph which confirm the existence of nonstructural films. The optical properties was done by recorded the transmittane and absorbance which were affected by an increase in concentration. The values of optical energy gap obtained from Tauc relation were 3.17, 3.18 and 3.19 eV for 0.05, 0.1 and 0.5 M respectively. Urbach energy confirms the decrease in band tail as the concentration increase.
Źródło:
World Scientific News; 2015, 22; 55-69
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural and Electrical Properties of SnO₂:F Thin Films Prepared by Chemical Vapor Deposition Method
Autorzy:
Najafi, N.
Rozati, S.
Powiązania:
https://bibliotekanauki.pl/articles/1030319.pdf
Data publikacji:
2017-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
chemical vapor deposition
SnO₂:F thin films
structural properties
electrical properties
Opis:
Fluorine doped tin oxide (FTO) thin films were deposited onto glass substrate at different substrate temperatures by a simple and inexpensive method of air pressure chemical vapor deposition. The substrate temperature was kept constant at about 500°C as the optimum temperature, and air was used as both a carrier gas and the oxidizing agent. A very simple method of characterization were carried on to investigate the electrical and structural properties of the prepared thin films. The electrical parameters variations showed that these parameters vary with substrate temperature ranging from an insulator thin film to a highly conductive layer. X-ray diffraction also revealed the structure to be polycrystalline at higher temperatures compared to amorphous structure for lower temperatures.
Źródło:
Acta Physica Polonica A; 2017, 131, 2; 222-225
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some structural properties of plant serine:glyoxylate aminotransferase?
Autorzy:
Truszkiewicz, Wiesław
Paszkowski, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/1041442.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
structural properties
peroxisomes
wheat
photorespiration
serine : glyoxylate aminotransferase
maize
Opis:
The structural properties of photorespiratory serine:glyoxylate aminotransferases (SGAT, EC 2.6.1.45) from maize (Zea mays L.) and wheat (Triticum aestivum L.) leaves were examined. By means of molecular sieving on Zorbax SE-250 column and filtration through centrifugal filters it was shown that dimers of wheat enzyme (molecular mass of about 90 kDa) dissociate into component monomers (molecular mass of about 45 kDa) upon decrease in pH value (from 9.1 or 7.0 to 6.5). At pH 9.1 a 50-fold decrease of ionic strength elicited a similar effect. Under the same conditions homodimers of the maize enzyme (molecular mass similar to that of the wheat enzyme) remained stable. Immunoblot analysis with polyclonal antiserum against wheat seedling SGAT on leaf homogenates or highly purified preparations of both enzymes showed that the immunogenic portions of the wheat enzyme are divergent from those of the maize enzyme. The sequence of 136 amino acids of the maize enzyme and 78 amino acids of the wheat enzyme was established by tandem mass spectrometry with time of flight analyzer. The two enzymes likely share similarity in tertiary and quaternary structures as well as high level of hydrophobicity on their molecular surfaces. They likely differ in the mechanism of transport from the site of biosynthesis to peroxisomes as well as in some aspects of secondary structure.
Źródło:
Acta Biochimica Polonica; 2005, 52, 2; 527-534
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Describing Minor 5-Stars in 3-Polytopes with Minimum Degree 5 and No Vertices of Degree 6 or 7
Autorzy:
Batueva, Ts.Ch-D.
Borodin, O.V.
Ivanova, A.O.
Nikiforov, D.V.
Powiązania:
https://bibliotekanauki.pl/articles/32361718.pdf
Data publikacji:
2022-05-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
planar graph
structural properties
3-polytope
5-star
neighborhood
Opis:
In 1940, in attempts to solve the Four Color Problem, Henry Lebesgue gave an approximate description of the neighborhoods of 5-vertices in the class P5 of 3-polytopes with minimum degree 5. This description depends on 32 main parameters. (6, 6, 7, 7, 7), (6, 6, 6, 7, 9), (6, 6, 6, 6, 11), (5, 6, 7, 7, 8), (5, 6, 6, 7, 12), (5, 6, 6, 8, 10), (5, 6, 6, 6, 17), (5, 5, 7, 7, 13), (5, 5, 7, 8, 10), (5, 5, 6, 7, 27), (5, 5, 6, 6, ∞), (5, 5, 6, 8, 15), (5, 5, 6, 9, 11), (5, 5, 5, 7, 41), (5, 5, 5, 8, 23), (5, 5, 5, 9, 17), (5, 5, 5, 10, 14), (5, 5, 5, 11, 13) Not many precise upper bounds on these parameters have been obtained as yet, even for restricted subclasses in P5. In 2018, Borodin, Ivanova, Kazak proved that every forbidding vertices of degree from 7 to 11 results in a tight description (5, 5, 6, 6, ∞), (5, 6, 6, 6, 15), (6, 6, 6, 6, 6). Recently, Borodin, Ivanova, and Kazak proved every 3-polytope in P5 with no vertices of degrees 6, 7, and 8 has a 5-vertex whose neighborhood is majorized by one of the sequences (5, 5, 5, 5, ∞) and (5, 5, 10, 5, 12), which is tight and improves a corresponding description (5, 5, 5, 5, ∞), (5, 5, 9, 5, 17), (5, 5, 10, 5, 14), (5, 5, 11, 5, 13) that follows from the Lebesgue Theorem. The purpose of this paper is to prove that every 3-polytope with minimum degree 5 and no vertices of degree 6 or 7 has a 5-vertex whose neighborhood is majorized by one of the ordered sequences (5, 5, 5, 5, ∞), (5, 5, 8, 5, 14), or (5, 5, 10, 5, 12).
Źródło:
Discussiones Mathematicae Graph Theory; 2022, 42, 2; 535-548
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Novel Theoretical Study of Elastic and Electronic Properties of M₂CdC (M = Zr, Hf, and Ta) MAX Phases
Autorzy:
Mebrek, M.
Mokaddem, A.
Doumi, B.
Yakoubi, A.
Mir, A.
Powiązania:
https://bibliotekanauki.pl/articles/1030613.pdf
Data publikacji:
2018-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
MAX phases
ab initio
structural properties
electronic properties
elastic properties
crystal structure
Opis:
In this study, we have investigated the structural, electronic, and elastic properties of the M₂CdC (M = Ta, Zr, and Hf) MAX phases, using the first-principle methods based on the density functional theory. The calculated formation energies revealed that these compounds are thermodynamically stable in the hexagonal MAX phase. The stability is confirmed by the elastic constants and the conditions of mechanical stability criterion. Also, we have determined the bulk and shear modules of the Young modulus and the Poisson coefficient. The band structures indicate that the three materials are electrically conductive. The chemical bond in M₂CdC is covalent-ionic in nature with the presence of metallic character. For the density of states the hybridization peak between M d and C p occurs in the lower energy range. We have found that there is no gap for these materials due to the existence of a maximum peak of DOS around Fermi level.
Źródło:
Acta Physica Polonica A; 2018, 133, 1; 76-81
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural and Optical Properties of Fe2O3 - NiO mixed Thin Films Prepared by Chemical Spray Pyrolysis
Autorzy:
Mohmmed, N. J.
Habubi, M. N.
Powiązania:
https://bibliotekanauki.pl/articles/412381.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Fe2O3
spray pyrolysis technique
structural properties
optical properties
Opis:
Mixed Fe2O3 - NiO thin films have been prepared by chemical Spray pyrolysis technique onto glass substrate preheated to 450 °C. The thickness of thin films was found to be (400 ±20) nm. XRD measurements reveal that all the film exhibit polycrystalline hexagonal wrutzite with a preferred orientation along (104) plane for pure and 10 % and 20 % Ni, while for the rest the structure was amorphous. AFM analysis indicate a nanostructure for all the films. The optical energy gap was found to be increased from optical transitions seems to be direct and the optical energy gap seems to be increased from 2.5 to 2.69 eV as the percentage of NiO increase.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 14, 1; 65-85
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Co Doping on Structural and Optical Properties of NiO Thin Films Prepared By Chemical Spray Pyrolysis Method
Autorzy:
Bakr, N. A.
Salman, S. A.
Shano, A. M.
Powiązania:
https://bibliotekanauki.pl/articles/412102.pdf
Data publikacji:
2015
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
NiO thin films
Co Doping
Chemical Spray Pyrolysis
Optical Properties
Structural Properties
Opis:
In this work, nickel-cobalt oxide (Ni(1-x)CoxO) thin films, where x = 0, 4, 6 and 8 % have been successfully deposited on glass substrates by chemical spray pyrolysis (CSP) technique at substrate temperature of (400 °C) and thickness of about 300 nm. The structural and optical properties of these films have been studied using XRD, AFM, and UV-Visible spectroscopy. The XRD results showed that all films are polycrystalline in nature with cubic structure and preferred orientation along (111) plane. The crystallite size was calculated using Scherrer formula and it is found that the undoped NiO sample has maximum crystallite size (51.16 nm). AFM results showed homogenous and smooth thin films. The absorbance and transmittance spectra have been recorded in the wavelength range of (300-900) nm in order to study the optical properties. The optical energy gap for allowed direct electronic transition was calculated using Tauc equation. It is found that the band gap decreases as the Co-concentration increases and the band gap values were in the range of 3.58-3.66 eV and 3.58 eV for the prepared Nickel-Cobalt Oxide thin films. The Urbach energy increases as the Co-concentration increases and the Urbach. The optical constants including (absorption coefficient, real and imaginary parts of dielectric constant) were also calculated as a function of photon energy. Refractive index and extinction coefficient for Nickel- Cobalt Oxide thin films were estimated as a function of wavelength.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2015, 41; 15-30
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modification in Physicochemical, Structural and Digestive Properties of Potato Starch During Heat-Moisture Treatment Combined with Microwave Pre- and Post-Treatment
Autorzy:
Deng, Chunli
Melnyk, Oksana
Marenkova, Tatyana
Luo, Yanghe
Powiązania:
https://bibliotekanauki.pl/articles/2159286.pdf
Data publikacji:
2022-09-05
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
heat-moisture treatment
microwave treatment
physicochemical properties
structural properties
digestibility
potato starch
Opis:
The objective of this study was to investigate the effects of modification by heat-moisture treatment (HMT) combined with microwave pre- and post-treatment (MW) on the physicochemical, structural and digestive properties of potato starch. The light microscopy, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) were used to determine the structural properties of starch. FT-IR and XRD spectra implied that MW and HMT destroyed the double helices and crystalline structure of potato starch. The relative crystallinity of modified starch granules (15.17–18.17%) was lower than that of native starch (19.39%). In the case of physicochemical properties, the modified starches had higher pasting temperature (68.8–93.0oC) and setback viscosity (807–3168 cP), but lower peak viscosity (1315–3662 cP) and breakdown viscosity (17.3–78.3 cP) than that of native potato starch, which were 68.5oC, 496 cP, 6598 cP and 2526 cP, respectively. The HMT and MW modifications significantly increased the content of slowly digestible starch and resistant starch. The resistant starch content of starch obtained by HMT combined with MW post-treatment was significantly higher than that of starch obtained by HMT combined with MW pre-treatment and single HMT. These results may promote good understanding of the effects of HMT combined with MW pre- and post-treatment on physicochemical properties and digestibility of potato starch, and wide utilization of microwave and heat-moisture techniques in starch modification.
Źródło:
Polish Journal of Food and Nutrition Sciences; 2022, 72, 3; 249-261
1230-0322
2083-6007
Pojawia się w:
Polish Journal of Food and Nutrition Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lignosulfonate and silica as precursors of advanced composites
Autorzy:
Klapiszewski, Ł.
Nowacka, M.
Siwińska-Stefańska, K.
Jesionowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/778432.pdf
Data publikacji:
2013
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Magnesium lignosulfonate
silica
Silica/lignosulfonate composite
Physicochemical and structural properties
Opis:
Advanced silica/lignosulfonate composites were obtained using magnesium lignosulfonate and silica precipitated in a polar medium. For comparative purposes analogous synthesis was performed using commercial silica Aerosil®200. Lignosulfonates are waste products of paper industry and their application in new multifunctional materials is of great economic interest. The composites obtained were subjected to thorough characterization by determination of their physicochemical, dispersive-morphological and electrokinetic properties. Their particle size distribution was measured, SEM images were taken, FT-IR analysis and colorimetric study were made, thermal and electrokinetic stabilities and parameters of porous structure were also determined. The results can be of interest in further application studies.
Źródło:
Polish Journal of Chemical Technology; 2013, 15, 3; 103-109
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural and biological characteristics of self-organising chitosan hydrogels
Autorzy:
Pieklarz, Katarzyna
Tylman, Michał
Modrzejewska, Zofia
Galita, Grzegorz
Majsterek, Ireneusz
Powiązania:
https://bibliotekanauki.pl/articles/2131528.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Tematy:
biomaterials
chitosan
cytotoxicity
self-organising hydrogels
structural properties
tissue engineering
Opis:
Creating innovative methods of treatment and regeneration of damaged tissues or organs is a key challenge of the twenty-first century. The aim of this study was to determine the possibility of producing and characterising the properties of self-organising chitosan hydrogels prepared with the use of chitosan lactate/chloride and disodium hydrogen phosphate dodecahydrate as a cross-linking agent. The structure and supramolecular architecture of the biomaterials were evaluated by Fourier-transform infrared spectroscopy and polarised optical microscopy. Biological studies assessed cytotoxicity by contact with a human colon adenocarcinoma cell line. The colourimetric resazurin assay showed that the obtained chitosan hydrogels are non-cytotoxic materials. Thus, self-organising biomaterials hold great promise for application in tissue engineering.
Źródło:
Progress on Chemistry and Application of Chitin and its Derivatives; 2021, 26; 191-199
1896-5644
Pojawia się w:
Progress on Chemistry and Application of Chitin and its Derivatives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enhanced photoelectrical performance of DSSC by Co-doped SnO2 nanoparticles
Autorzy:
Priyadharsini, C. I.
Prakasam, A.
Anbarasan, P. M.
Powiązania:
https://bibliotekanauki.pl/articles/412628.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
co–doped SnO2 nanoparticles
Natural Sensitizer
Structural properties
Absorption spectrum
Opis:
Investigation of the I-V characteristics of the DSSC based on interconnected with cobalt-doped SnO2 nanoparticles covered with a nano-scale thin layer which was absorbed by natural dyes are described. The presence of co-doped SnO2 has been confirmed by its characteristic XRD pattern and the shape of the particle is confirmed by SEM. The thickness of the protective layer can be conveniently controlled by the mole value of co-doped SnO2 used in the preparation of the thin film and the optimum conditions for best performance of the DSSC are presented together with possible explanation for the variations observed. An optimum light-to-electricity conversion efficiency of 0.37 % in the presence of a layer of co-doped SnO2 has been obtained which enhancement over the cell prepared with other natural dyes. The characterization of the sample using different techniques was explained (change the sentence).
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 12; 82-93
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generalised Odd Frechet Family of Distributions: Properties and Applications
Autorzy:
Marganpoor, Shahdie
Ranjbar, Vahid
Alizadeh, Morad
Abdollahnezhad, Kamel
Powiązania:
https://bibliotekanauki.pl/articles/1058928.pdf
Data publikacji:
2020-09-04
Wydawca:
Główny Urząd Statystyczny
Tematy:
Frechet distribution
Wiebull distribution
structural properties
failure-time
maximum likelihood estimation
Opis:
A new distribution called Generalized Odd Fréchet (GOF) distribution is presented and its properties explored. Some structural properties of the proposed distribution, including the shapes of the hazard rate function, moments, conditional moments, moment generating function, skewness, and kurtosis are presented. Mean deviations, Lorenz and Bonferroni curves, Rényi entropy, and the distribution of order statistics are given. The maximum likelihood estimation technique is used to estimate the model parameters, and finally applications of the model to a real data set are presented to illustrate the usefulness of the proposed distribution.
Źródło:
Statistics in Transition new series; 2020, 21, 3; 109-128
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
More About the Height of Faces in 3-Polytopes
Autorzy:
Borodin, Oleg V.
Bykov, Mikhail A.
Ivanova, Anna O.
Powiązania:
https://bibliotekanauki.pl/articles/31342325.pdf
Data publikacji:
2018-05-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
plane map
planar graph
3-polytope
structural properties
height of face
Opis:
The height of a face in a 3-polytope is the maximum degree of its incident vertices, and the height of a 3-polytope, h, is the minimum height of its faces. A face is pyramidal if it is either a 4-face incident with three 3-vertices, or a 3-face incident with two vertices of degree at most 4. If pyramidal faces are allowed, then h can be arbitrarily large, so we assume the absence of pyramidal faces in what follows. In 1940, Lebesgue proved that every quadrangulated 3-polytope has h ≤ 11. In 1995, this bound was lowered by Avgustinovich and Borodin to 10. Recently, Borodin and Ivanova improved it to the sharp bound 8. For plane triangulation without 4-vertices, Borodin (1992), confirming the Kotzig conjecture of 1979, proved that h ≤ 20, which bound is sharp. Later, Borodin (1998) proved that h ≤ 20 for all triangulated 3-polytopes. In 1996, Horňák and Jendrol’ proved for arbitrarily polytopes that h ≤ 23. Recently, Borodin and Ivanova obtained the sharp bounds 10 for trianglefree polytopes and 20 for arbitrary polytopes. In this paper we prove that any polytope has a face of degree at most 10 with height at most 20, where 10 and 20 are sharp.
Źródło:
Discussiones Mathematicae Graph Theory; 2018, 38, 2; 443-453
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Właściwości mechaniczne i strukturalne tętniaków aorty brzusznej
Mechanical and structural properties of abdominal aortic aneurysms
Autorzy:
Kobielarz, M.
Szotek, S.
Kuropka, P.
Kaleta, K.
Powiązania:
https://bibliotekanauki.pl/articles/285908.pdf
Data publikacji:
2008
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
tętniaki aorty brzusznej
właściwości mechaniczne
właściwości strukturalne
abdominal aortic aneurysm
mechanical properties
structural properties
Opis:
W celu oszacowania prawdopodobieństwa przerwania ciągłości ściany tętniaka aorty brzusznej (AAA) konieczne jest zbadanie warunków obciążeniowych odpowiedzialnych za to zdarzenie, a także identyfikacja zmian zachodzących w strukturze ściany tego naczynia w procesie rozwoju schorzenia. Stąd, głównym celem prezentowanej pracy jest określenie mechanicznych oraz strukturalnych właściwości ścian tętniaków aorty brzusznej oraz preparatów zdrowych aort. W tym celu zastosowano test jednoosiowego rozciągania próbek wyciętych z pobranych preparatów w dwóch prostopadłych do siebie kierunkach: wzdłużnym oraz obwodowym, a także przeprowadzono histologiczne badania mikrostruktury ściany naczyń. Na podstawie przeprowadzonego testu wytrzymałościowego wykreślono krzywą naprężenie-odkształcenie dla każdego przebadanego przypadku i wyznaczono charakterystyczne wielkości opisujące wytrzymałość oraz sztywność przebadanych próbek. Uzyskane wyniki wskazują na istotny wzrost sztywności w przypadku preparatów ścian tętniaków, co szczególnie zaznaczyło się w kierunku obwodowym.
To estimate when an abdominal aortic aneurysm (AAA) may rupture, it is necessary to understand the forces responsible for this event and structural alterations lead to changes in the mechanical properties of the tissue. Hence, the main goal of presented study is determination and assessment of mechanical and structural properties of the walls of normal abdominal aortas and abdominal aortic aneurysms. With this end in view uniaxial tensile tests of the specimens cut out from the walls of abdominal aortic aneurysms and normal abdominal aortas in two directions - longitudinal and circumferential - have been carried out and histological study has been performed. On the basis of these tests the stress-strain relationships have been determined for each investigated specimen and the maximum tangential modulus as well as the ultimate tensile strength has been assigned. The results indicate the increase of tissue stiffness in the case of abdominal aortic aneurysms, especially in the circumferential direction.
Źródło:
Engineering of Biomaterials; 2008, 11, no. 81-84; 98-100
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural, Mechanical and Thermodynamic Properties Under Pressure Effect of Rubidium Telluride: First Principle Calculations
Autorzy:
Bidai, K.
Ameri, M.
Ameri, I.
Bensaid, D
Slamani, A.
Zaoui, A.
Al-Douri, Y.
Powiązania:
https://bibliotekanauki.pl/articles/354182.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Anti-fluorite: Rb2Te; FP-LAPW; GGA
structural properties
thermodynamics properties
elastic constants
Opis:
First-principles density functional theory calculations have been performed to investigate the structural, elastic and thermodynamic properties of rubidium telluride in cubic anti-fluorite (anti-CaF2-type) structure. The calculated ground-state properties of Rb2Te compound such as equilibrium lattice parameter and bulk moduli are investigated by generalized gradient approximation (GGA-PBE) that are based on the optimization of total energy. The elastic constants, Young’s and shear modulus, Poisson ratio, have also been calculated. Our results are in reasonable agreement with the available theoretical and experimental data. The pressure dependence of elastic constant and thermodynamic quantities under high pressure are also calculated and discussed.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2A; 865-871
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Use of MgO to Promote the Oxyethylation Reaction of Lauryl Alcohol
Autorzy:
Pilarska, A.
Lukosek, M.
Siwińska-Stefańska, K.
Pilarski, K.
Jesionowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/779641.pdf
Data publikacji:
2014
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
magnesium hydroxide and oxide
precipitation
dispersive and structural properties
oxyethylation
catalytic activity
Opis:
Synthesis of magnesium hydroxide was performed by the precipitation method with the use of magnesium sulfate and sodium hydroxide. The infiuence of temperature and ratio of reagents was studied. Magnesium hydroxides, and the magnesium oxides obtained from them by thermal decomposition, were analyzed to determine their bulk density, polydispersity and particle size. The magnesium oxide with the largest surface area was tested as a catalyst in the oxyethylation of lauryl alcohol, and shown to be selective but poorly reactive in comparison with commercially available catalysts. Further studies are needed to improve its reactivity.
Źródło:
Polish Journal of Chemical Technology; 2014, 16, 2; 36-42
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Light Minor 5-Stars in 3-Polytopes with Minimum Degree 5 and No 6-Vertices
Autorzy:
Borodin, Oleg V.
Ivanova, Anna O.
Vasil’eva, Ekaterina I.
Powiązania:
https://bibliotekanauki.pl/articles/31348169.pdf
Data publikacji:
2020-11-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
planar map
planar graph
3-polytope
structural properties
5-star
weight
height
Opis:
In 1940, Lebesgue gave an approximate description of the neighborhoods of 5-vertices in the class P5 of 3-polytopes with minimum degree 5. Given a 3-polytope P, by w(P) denote the minimum of the degree-sum (weight) of the neighborhoods of 5-vertices (minor 5-stars) in P. In 1996, Jendrol’ and Madaras showed that if a polytope P in P5 is allowed to have a 5-vertex adjacent to four 5-vertices, then w(P) can be arbitrarily large. For each P in P5 without vertices of degree 6 and 5-vertices adjacent to four 5-vertices, it follows from Lebesgue’s Theorem that w(P) ≤ 68. Recently, this bound was lowered to w(P) ≤ 55 by Borodin, Ivanova, and Jensen and then to w(P) ≤ 51 by Borodin and Ivanova. In this note, we prove that every such polytope P satisfies w(P) ≤ 44, which bound is sharp.
Źródło:
Discussiones Mathematicae Graph Theory; 2020, 40, 4; 985-994
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Low 5-Stars at 5-Vertices in 3-Polytopes with Minimum Degree 5 and No Vertices of Degree from 7 to 9
Autorzy:
Borodin, Oleg V.
Bykov, Mikhail A.
Ivanova, Anna O.
Powiązania:
https://bibliotekanauki.pl/articles/31348144.pdf
Data publikacji:
2020-11-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
planar map
planar graph
3-polytope
structural properties
5-star
weight
height
Opis:
In 1940, Lebesgue gave an approximate description of the neighborhoods of 5-vertices in the class $P_5$ of 3-polytopes with minimum degree 5. Given a 3-polytope $P$, by $h_5(P)$ we denote the minimum of the maximum degrees (height) of the neighborhoods of 5-vertices (minor 5-stars) in $P$. Recently, Borodin, Ivanova and Jensen showed that if a polytope $P$ in $P_5$ is allowed to have a 5-vertex adjacent to two 5-vertices and two more vertices of degree at most 6, called a (5, 5, 6, 6, ∞)-vertex, then $h_5(P)$ can be arbitrarily large. Therefore, we consider the subclass \(P_5^\ast\) of 3-polytopes in $P_5$ that avoid (5, 5, 6, 6, ∞)-vertices. For each $P^\ast$ in $P_5^\ast$ without vertices of degree from 7 to 9, it follows from Lebesgue’s Theorem that $h_5(P^\ast) ≤ 17$. Recently, this bound was lowered by Borodin, Ivanova, and Kazak to the sharp bound $h_5(P^\ast) ≤ 15$ assuming the absence of vertices of degree from 7 to 11 in $P^\ast$. In this note, we extend the bound $h_5(P^\ast) ≤ 15$ to all $P^\ast$s without vertices of degree from 7 to 9.
Źródło:
Discussiones Mathematicae Graph Theory; 2020, 40, 4; 1025-1033
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Possibilities to Obtain Products from 2024 and 7075 Chips in the Process of Consolidation by KoBo Extrusion
Autorzy:
Pawłowska, B.
Śliwa, R. E.
Zwolak, M.
Powiązania:
https://bibliotekanauki.pl/articles/355868.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
metallic chips
KoBo method
cold plastic consolidation
structural properties of extrudate
mechanical properties of extrudate
Opis:
Basing on experimental data, the possibility of consolidating side products of turning, milling and drilling of aluminum alloys into the form and properties of solids metals using low-temperature KoBo extrusion method has been assessed. Research regarding mechanical and structural properties of the final products revealed their total consolidation and proved their compatibility with requirements for products made of bulk billets. Importantly, the chips consolidation process does not require high or even raised temperature, which significantly reduces the unfavorable phenomenon of chips oxidation and its negative influence on the structure and mechanical properties of products. A very good effect of chips compaction has been proved by KoBo method, which has been confirmed by relatively slightly different mechanical properties of the material after recycling compared with the bulk one. Among currently applied techniques of consolidation of dispersed fractions in a solid state (leaving the melting stage out), the KoBo method seems an innovative way of utilizing metallic chips, as it enables a cold deformation process.The paper presents investigations using 2024 and 7075 aluminum alloys chips from manufacturing process, formed into briquettes and deformed under conditions of KoBo extrusion process, which enables to obtain long product by cold forming. The final product characterized by good microstructures, mechanical features and low cost of production.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 4; 1213-1221
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-25 z 97

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies