Informacja

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

Wyszukujesz frazę "fa" wg kryterium: Temat


Tytuł:
Cross Sections for l-Mixing of K(n$\text{}^{2}$F) States in Collisions with Ground-State K(4$\text{}^{2}$S) Atoms
Autorzy:
Głódź, M.
Huzandrov, A.
Klavins, J.
Sydoryk, I.
Szonert, J.
Gateva-Kostova, S.
Kowalski, K.
Powiązania:
https://bibliotekanauki.pl/articles/2014246.pdf
Data publikacji:
2000-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
34.50.Fa
Opis:
We report measurements of the cross sections σ$\text{}_{l-mix}$ for angular momentum mixing of the K(n$\text{}^{2}$F)(n=6, 7, 8) states with the K(n,l > 3) states, induced in thermal collisions with parent ground state K(4$\text{}^{2}$S) atoms. The experiment was performed in a cell heated to ca. 450K. The n$\text{}^{2}$F states were excited in two steps: 4$\text{}^{2}$S → 4$\text{}^{2}$P → n$\text{}^{2F}$ by using a diode laser for the first step (a dipole-transition) and a pulsed dye laser for the second step (a quadrupole-transition). The measured values σ$\text{}_{l-mix}$ (6$\text{}^{2}$F)=3.6+-2.2, σ$\text{}_{l-mix}$ (7$\text{}^{2}$F)=4.2+-2.6 and σ$\text{}_{l-mix}$ (8$\text{}^{2}$F)=8.0+-4.6 (in units of 10$\text{}^{-13}$cm$\text{}^{-1}$) are close to the corresponding values of the geometrical cross sections.
Źródło:
Acta Physica Polonica A; 2000, 98, 4; 353-361
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gamma Ray Shielding Properties of Some Concrete Materials
Autorzy:
Fugaru, V.
Bercea, S.
Postolache, C.
Manea, S.
Moanta, A.
Petre, I.
Gheorghe, M.
Powiązania:
https://bibliotekanauki.pl/articles/1192350.pdf
Data publikacji:
2015-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
28.52.Fa
Opis:
Concrete of various type have been used extensively for the adequate shielding of the radiological equipment using X and gamma rays. In its basic form, concrete is composed of pieces of inert aggregate held together by hardened cement paste. Different concrete types with special cements have been prepared. The linear attenuation coefficients of conventional concrete and concrete with supplementary mineral additives (barite and witherite) at different gamma energies (Co-60: 1.25 MeV, Cs-137: 0.662 MeV, Ir-192: 0.37 MeV) in narrow beam conditions have been measured. This paper includes some experimental data regarding the influence of barite and witherite additives on photon attenuation coefficients of concrete.
Źródło:
Acta Physica Polonica A; 2015, 127, 4; 1427-1429
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evolution of the International Metric System of Units SI
Autorzy:
Chyla, W.
Powiązania:
https://bibliotekanauki.pl/articles/1492767.pdf
Data publikacji:
2011-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
06.20.fa
Opis:
Once the New SI is approved by the General Conference on Weights and Measures (CGPM), all base units of the international metric system of units (SI) will be defined in terms of physical constants and atomic properties. In this paper, we consider the rationale and the direction of the possible further evolution of the SI. The idea is to define all base units exclusively in terms of fundamental physical constants, with no reference to specific phenomena, physical theories or properties of material entities (including properties of atoms and elementary particles), so that those definitions would not have to be altered or amended following advancement in our understanding of the structure of matter, emergence of new physical theories or due to the technological progress. New developments in science and technology would then affect only the mise en pratique (realization) of base units, rather than their definitions. Furthermore, we point out the need for including base units for the weak interaction and the strong interaction into the SI and propose a way to do it. The structure of the fundamental-constants-based system of units (the FC SI) is discussed and prerequisites for the implementation of the FC SI are considered.
Źródło:
Acta Physica Polonica A; 2011, 120, 6; 998-1011
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
GaAlAs Allox/Pseudoalloy Type II Structures
Autorzy:
Jeżewski, M.
Teissier, R.
Planel, R.
Powiązania:
https://bibliotekanauki.pl/articles/1879871.pdf
Data publikacji:
1991-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.65.Fa
Opis:
The existence of type-II structures made from the combination of Ga$\text{}_{1-x}$AI$\text{}_{x}$As alloy and a short period GaAs/AlAs type-I superlattice is presented. Such three material structures are of type-II having at the same time electrons and holes of Γ-symmetry. This contrasts with the usual situation in type-II two material GaAs/AlAs structure where the ground state of electrons is of X-symmetry. The mechanism allowing creation of three material type-II structures is based on the difference of effective masses of electrons and holes. It should be valid for all similar semiconductor systems. Experimental results of photoluminescence and photoluminescence excitation studies of such structures made by Molecular Beam Epitaxy are presented. We determine the mutual positions of the electron and hole ground levels in the alloy and pseudoalloy and confirm that the studied structure is of type-II.
Źródło:
Acta Physica Polonica A; 1991, 79, 2-3; 195-198
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vickers Hardness and Positron Annihilation Study of Eurofer97 and ODS Eurofer
Autorzy:
Bartošová, I.
Čížek, J.
Lukáč, F.
Slugeň, V.
Powiązania:
https://bibliotekanauki.pl/articles/1196045.pdf
Data publikacji:
2014-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
28.52.Fa
Opis:
This paper describes investigations of Eurofer97 and oxide dispersion strengthened version of this steel, in as received state and after annealing. Vickers hardness test was performed on the as received specimens and after annealing at various temperatures to obtain information about development of the strength of studied materials. After identifying the temperature region where significant changes of the strength take place we applied positron annihilation spectroscopy to probe the microstructural changes in ferritic/martensitic steels. An observation of phase transformation was observed in both steels at various temperatures indicating different behaviour of the base material and its strengthened version. All applied methods proved the importance of strengthening by oxides to improve properties of steels.
Źródło:
Acta Physica Polonica A; 2014, 125, 3; 702-705
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characteristics and biological properties of ferulic acid
Autorzy:
Dędek, Kamil
Rosicka-Kaczmarek, Justyna
Nebesny, Ewa
Kowalska, Gabriela
Powiązania:
https://bibliotekanauki.pl/articles/410448.pdf
Data publikacji:
2019
Wydawca:
Politechnika Łódzka. Wydawnictwo Politechniki Łódzkiej
Tematy:
ferulic acid
FA
health-promoting properties of FA
synthesis of FA in plants
metabolism of FA
kwas ferulowy
własciwości prozdrowotne kwasu ferulowego
synteza kwasu ferulowego u roślin
metabolizm kwasu ferulowego
Opis:
The interest in the properties of hydroxycinnamic acids with health-promoting properties is constantly increasing. That is why more and more research is being conducted to better understand these properties. Ferulic acid, FA (4-hydroxy-3-methoxycinnamic acid) is a derivative of hydroxycinnamic acid found in the plant tissue. It is possible to find him among others in bran cereal, popcorn bamboo shoots, and coffee. According to available literature data ferulic acid has a lot of biological properties, particularly appreciated in medicine. Its bioactive properties effectively contribute to the fight against diseases described as a civilization, including neurodegenerative diseases that increase the incidence. As reported the World Alzheimer Report, the number of people with dementia progression in 2016 exceeded 47.5 million, of which 33.5 million were diagnosed with Alzheimer's disease. According to the WHO estimates, this number will triple by 2050. The manuscript presents health-promoting properties of FA on the example of its antioxidant, antidiabetic, hepatoprotective, anti-atherosclerotic, neuroprotective, antineoplastic and antibacterial properties. In addition, the reaction of its synthesis in plants and in-vivo metabolization have been explained. The collected data suggest that bioactive FA molecules can effectively reduce the risk of civilization diseases and significantly reduce the level of oxidative stress contributing to the formation of neurodegenerative diseases.
Źródło:
Biotechnology and Food Science; 2019, 83, 1; 71-85
2084-0136
2299-6818
Pojawia się w:
Biotechnology and Food Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radiation Shielding Properties of Mortars and Plasters Used in Historical Buildings
Autorzy:
Özavci, S.
Çetın, B.
Powiązania:
https://bibliotekanauki.pl/articles/1031750.pdf
Data publikacji:
2017-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
28.52.Fa
28.41.Qb
Opis:
In this study, the radiation absorption properties of mortars and plasters used in historical buildings have been investigated. Studied lime concretes contained such additives as brick dust, fertilizer, wet lime, wool, egg white, bone meal, rice, casein, whey, bone ash and tree leaf juice, in different concentrations. The linear attenuation coefficients of gamma rays in lime concretes have been measured at 662, 1773 and 1332 keV. The gamma rays have been obtained from ¹³⁷Cs and ⁶⁰Co sources and the measurements have been performed using a gamma spectrometer, based on a 3"× 3" NaI(Tl) detector, connected to 16384-channel multi-channel analyser.
Źródło:
Acta Physica Polonica A; 2017, 132, 3; 986-987
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Usability of Fuzzy Logic Modeling for Prediction of Fresh Properties of Self-Compacting Concrete
Autorzy:
Beycioğlu, A.
Gültekin, A.
Aruntaş, H.
Powiązania:
https://bibliotekanauki.pl/articles/1031137.pdf
Data publikacji:
2017-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
07.05.Mh
28.52.Fa
Opis:
The aim of this study is to investigate the usability of fuzzy logic modelling for prediction of fresh properties of self-compacting concrete. In the modelling process, the percentage of fly ash and the percentage of granulated blast furnace slag, as replacement of cement, the percentage of micronized calcite, as replacement of total aggregate, were used as inputs. The slump flow diameter and time and also the V-funnel time were used as outputs. Results show that fuzzy logic modelling may be a useful approach to predict fresh properties of self-compacting concrete, containing fly ash, granulated blast furnace slag and micronized calcite.
Źródło:
Acta Physica Polonica A; 2017, 132, 3; 1140-1141
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of radiation attenuation coefficients in concretes containing different wastes
Autorzy:
Özavci, S.
Çetın, B.
Powiązania:
https://bibliotekanauki.pl/articles/1068130.pdf
Data publikacji:
2016-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
28.52.Fa
28.41.Qb
Opis:
Environmental wastes can be cleaned in a very long time by ecosystem. However, the cleaning power of the ecosystem is not enough. For this reason, the evaluation of the different areas of waste processing is important. In this study attenuation coefficient of gamma rays has been investigated for concretes containing different amounts of glass, bulb and plastic wastes.
Źródło:
Acta Physica Polonica A; 2016, 130, 1; 316-317
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of the natural radioactivity level of Amasya Şeyhcui Region
Autorzy:
Coşkun, A.
Çetın, B.
Powiązania:
https://bibliotekanauki.pl/articles/1068311.pdf
Data publikacji:
2016-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
28.52.Fa
28.41.Qb
Opis:
People are exposed to both internal and external radiation from the natural radiation sources. For this reason, studies determining the natural radiation level are made to detect the effects of radionuclides, that constitute the natural radiation sources, on the environment and especially the effects of radiation on people and on biological systems. The most common radiation sources are ²³⁸U, ²²⁶Ra, ²³²Th and ⁴⁰K radioisotopes. In this study, in the samples of the rock and soil acquired from Amasya Şeyhcui Region, the activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K are determined by using NaI (Tl) detector with gamma spectrometer and are compared with the limit values.
Źródło:
Acta Physica Polonica A; 2016, 130, 1; 309-310
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Josephson Network as a Model for Inhomogeneous Superconductor: a Microwave Power Absorption
Autorzy:
Rycerz, A.
Spałek, J.
Powiązania:
https://bibliotekanauki.pl/articles/2047320.pdf
Data publikacji:
2007-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.81.Fa
74.25.Nf
Opis:
We discuss the applied magnetic field dependence of the microwave absorption by a three-dimensional array of up to 30×30 ×30 Josephson junctions with random parameters including the resistivity, capacity, and inductance of each junction. The numerical simulation results for the networks show characteristic microwave absorption anomalies observed in the ceramic samples of high temperature superconductor YBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-x}$. We also provide a discussion of the absorption in simple analytical terms of the Josephson loop instabilities.
Źródło:
Acta Physica Polonica A; 2007, 111, 4; 581-594
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Physics of GaAs/AlAs Superlattices
Autorzy:
Planel, R.
Mollot, F.
Powiązania:
https://bibliotekanauki.pl/articles/1877495.pdf
Data publikacji:
1991-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.65.Fa
68.55.Bd
Opis:
We describe the main problems encountered in MBE growth of GaAs/AlAs superlattices and heterostructures. Then, basic features for the understanding of their electronic properties are given, in the envelope-function formalism, and some related optical experiments are reviewed.
Źródło:
Acta Physica Polonica A; 1991, 79, 1; 71-82
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Raman Scattering and Electrical Properties of TGS:PCo (9%) Crystal as Ambient Temperature IR Detector
Autorzy:
Malekfar, R.
Daraei, A.
Powiązania:
https://bibliotekanauki.pl/articles/1812050.pdf
Data publikacji:
2008-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.30.-j
77.84.Fa
Opis:
We developed and adequately characterized the triglycine sulfate family crystals doped with specific molar percent of cobalt phosphate, TGS:PCo (9%). The crystals were grown by slow evaporation technique and the growth rates of different crystallographic planes are rather faster in comparison with the plane growth rates of pure TGS crystals. The introduction of $Co^{2+}$ ion as an active optical element to the structure of TGS crystal leads to optimization of some parameters such as optical quality, stability at ambient condition, Curie temperature, stronger Raman peaks, etc. Three new peaks at 460, 620 and 1368 $cm^{-1}$ were observed in the dispersive back scattering Raman spectra of the grown TGS:PCo (9%) crystal in comparison with the pure triglycine sulfate crystal.
Źródło:
Acta Physica Polonica A; 2008, 114, 4; 859-867
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Raman Spectra and Structural Data of the Nanocrystalline KTP $(KTiOPO_4)$ Synthesized by Pechini Method
Autorzy:
Malekfar, R.
Cheraghi, A.
Ahmadi, G.
Khanzadeh, M.
Powiązania:
https://bibliotekanauki.pl/articles/1585099.pdf
Data publikacji:
2009-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.30.-j
77.84.Fa
Opis:
Nanocrystalline KTP powders are synthesized using a modified Pechini method. The structural and lattice modes of the products are investigated via X-ray diffraction, micro Raman backscattering spectroscopy, UV/vis/NIR and FT-IR transmission spectroscopy. The Debye-Scherrer formula is used to confirm the grain sizes estimated by the scanning electron microscopy slides.
Źródło:
Acta Physica Polonica A; 2009, 116, 6; 1073-1075
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enhanced External Counterpulsation in Patients with Advanced Ischemic Cardiomyopathy
Autorzy:
Przywara-Chowaniec, B.
Gawlikowski, M.
Kuczaj, A.
Bachorz, M.
Czechowski, P.
Kowalski, P.
Geodecki, M.
Kawecki, D.
Barańska, K.
Paluch, M.
Pluszczyk, M.
Opara, M.
Puzio, A.
Nowalany-Kozielska, E.
Powiązania:
https://bibliotekanauki.pl/articles/1418031.pdf
Data publikacji:
2012-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
47.63.Ec
82.60.Fa
Opis:
A significant increase in the number of patients with heart failure of varied etiology has been observed in the recent years. Apart from pharmacological and surgical therapies, new, non-invasive assistance methods of cardiovascular system are still sought. One of them is external counterpulsation. Within this study, effectiveness of such a form of therapy has been examined in a group of 10 patients with an ischemic left ventricular systolic dysfunction. It has been shown that external counterpulsation has a beneficial influence onto the result of a six-minute walk test and causes a slight decrease in the creatinine concentration in the patients undergoing the tests.
Źródło:
Acta Physica Polonica A; 2012, 122, 5; 866-869
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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