Temat: 25.20.-x - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Photoactivation Analysis of Mineral Trioxide Aggregate: Preliminary Results
Autorzy:: Eke, C.
Er, K.
Segebade, C.
Boztosun, I.
Tematy:: 25.20.-x
29.20.Ej; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1031466.pdf Link otwiera się w nowym oknie
Opis:: The purpose of this study is to qualitatively analyse the elemental components of a mineral trioxide aggregate material using photoactivation. The material was irradiated for two hours using bremsstrahlung photons with an end-point energy of 18 MeV from a clinical electron linear accelerator. After irradiation the gamma-ray emission of the sample was counted by gamma spectrometry using a high-purity germanium (HPGe) detector. The gamma-ray spectra were analyzed by computer software. Major and trace elements were detected.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Cross Sections Calculation of (γ,N) Reactions for Some Elements
Autorzy:: Karpuz, N.
Boz, M.
Mavi, B.
Akkurt, I.
Tematy:: 24.10.-i
25.20.-x; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1402484.pdf Link otwiera się w nowym oknie
Opis:: Photonuclear processes can play an important role in the detection of nuclear materials. For this purpose, in this study, the (γ,n) and (γ,p) cross sections as functions of photon energy in medium weight nuclei were calculated. Calculations have been made of the cross sections for some of the (γ,n) and (γ,p) reactions in $\text{}^{28}Si,$ $\text{}^{32}S,$ $\text{}^{56}Fe$ and $\text{}^{63}Cu$ nuclei using the TALYS 1.6 nuclear code with incident photons of 7-40 MeV. These calculated cross sections are compared with each other and with the earlier experimental results from the literature (EXFOR). Calculated results ($\text{}^{56}Fe(γ,n),$ $\text{}^{63}Cu(γ,n),$ $\text{}^{56}Fe(γ,p)$ and $\text{}^{63}Cu(γ,p)$ cross sections) are in very good agreement with the experimental data. However, because of the Coulomb barrier, the photoproton cross sections for $\text{}^{32}S,$ $\text{}^{56}Fe$ and $\text{}^{63}Cu$ target nuclei, are smaller than the photoneutron cross sections.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Theoretical Photoneutron Cross Sections and the Effect of Gamma Strength Functions for W, Ag, Nb
Autorzy:: Karpuz Demir, N.
Çetin, B.
Tematy:: 24.10.-i
25.20.-x; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1031930.pdf Link otwiera się w nowym oknie
Opis:: In nuclear reactions the usage of high energy gamma particles, as projectiles, has some essential advantages for studying of nuclear structure and reaction mechanisms. In this work, (γ,n) reaction cross sections of ¹⁸⁶W, ¹⁰⁷Ag and ⁹³Nb have been calculated with TALYS 1.6 nuclear reaction simulation code. The main aim of this study is to investigate the effects of preequilibrium and the gamma strength functions on ¹⁸⁶W, ¹⁰⁷Ag and ⁹³Nb. The calculated results have been discussed and compared with the experimental data.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Variation of Photoneutron Cross Section with Mass Number
Autorzy:: Karpuz, N.
Boz, M.
Mavi, B.
Akkurt, I.
Tematy:: 25.20.-x
13.85.Lg; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1402482.pdf Link otwiera się w nowym oknie
Opis:: Photonuclear reactions play an important role in many different subfields of nuclear astrophysics, and fields, such as nucleosynthesis applications. The photonuclear reaction cross sections, especially the photoneutron reaction cross sections, are the fundamental properties of nuclear systems. In this study, theoretical evaluation of photoneutron reaction cross sections for 27 ≤ A ≤ 238 targets ($\text{}^{27}Al,$ $\text{}^{96}Mo,$ $\text{}^{181}Ta,$ $\text{}^{238}U$) have been investigated in the incident photon energy range of 7-35 MeV. Monte Carlo code TALYS 1.6 was used to calculate the photoneutron cross sections. The results are compared with the earlier experimental reports in literature and the cross section data in the TENDL-2013 nuclear reaction data library, based on subsequent versions of the TALYS nuclear code system. The photoneutron cross section results and the effects of the mass number of target nuclei are discussed.
Dostawca treści:: Biblioteka Nauki

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na półce

Skocz do pozycji: 5.

Tytuł:: Calculation of Gamma Strength Functions for Photonucleon Reactions
Autorzy:: Karpuz, N.
Mavi, B.
Akkurt, İ.
Tematy:: 24.10.-i
25.20.-x; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1402486.pdf Link otwiera się w nowym oknie
Opis:: The cross section for (γ,N) reaction is important for investigation of nuclear structure, especially in low-energy giant dipole resonance (GDR). The total cross sections of $\text{}^{12}C(γ,n)^{11}C$ and $\text{}^{12}C(γ,p)^{11}B$ reactions, calculated using TALYS 1.2 nuclear code, are 15.5 to 40 MeV and 15 to 110 MeV, respectively. In the calculations, the default pre-equilibrium models and Brink-Axel Lorentzian model in all of the gamma strength functions have been used. The effects of the gamma strength function on the cross section exchange data has determined the most compatible model type. The results are compared with the experimental data from the EXFOR database and the evaluated nuclear data from TENDL-2012. Our calculated results are in good agreement with the previously reported experimental results.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Non-Wave Variations in Temperature Caused by Sound in a Chemically Reacting Gas
Autorzy:: Perelomova, A.
Pelc-Garska, W.
Tematy:: 43.25.-x
43.20.Bi; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1493610.pdf Link otwiera się w nowym oknie
Opis:: A weakly nonlinear generation of non-acoustic modes in the field of sound in a gas is considered. An exoteric chemical reaction of A → B type, which takes place in a gas, may be reversible or not. Two types of sound are considered, low-frequency and high-frequency as compared with the characteristic time of a chemical reaction. For both these cases, the governing equations of non-acoustic modes are derived and conclusions of the efficiency of their nonlinear generation by sound are made. The character of nonlinear generation of non-acoustic modes by sound depends essentially on reversibility of a chemical reaction.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Effects of material non-homogeneity and two parameter elastic foundation on fundamental frequency parameters of Timoshenko beams
Autorzy:: Avcar, M.
Tematy:: 61.43.Bn
62.20.-x
62.25.Jk
89.20.Kk; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1070359.pdf Link otwiera się w nowym oknie
Opis:: In the present study, effects of material non-homogeneity and two-parameter elastic foundation on the fundamental frequency parameters of the simply supported beams are examined. Material non-homogeneity is characterized taking into account the parabolic variations of Young's modulus and density along the thickness direction of the beam while the value of Poisson's ratio is assumed to remain constant. The foundation medium is assumed to be linear, homogeneous and isotropic, and it is modeled by the Pasternak model with two parameters for describing the reaction of the elastic foundation on the beam. At first, the equation of the motion including the effects of the material non-homogeneity and two-parameter elastic foundation is provided. Then, the solutions including fundamental frequency parameters versus various non-homogeneity, density and foundation parameters, and length to depth ratio adopting the Timoshenko beam theory as well as the Euler-Bernoulli beam theory are presented. To show the accuracy of the present results, a comparison is carried out and a good agreement is found.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Design, Modeling and Simulation of MEMS Devices on Si, SiC, and Diamond for Harsh Environment Applications
Autorzy:: Kociubiński, A.
Bieniek, T.
Janczyk, G.
Tematy:: 07.05.Tp
07.07.Df
62.20.-x
62.25.Fg; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1199152.pdf Link otwiera się w nowym oknie
Opis:: Set of micromechanical (MEMS) test structures designed for fabrication on silicon, silicon carbide and diamond substrates has been successfully designed. A dedicated mask-set development has been carried along with numerical simulations performed with assistance of a dedicated design and modelling CoventorWare™ - toolset by Coventor. A set of sample simulations presented in this paper has been performed for specific simulation domains focused on silicon-alternative material reality to proof the usefulness of proposed substrates. The aim was to verify its applicability for MEMS design and confirm an outstanding performance of the resulting device which effectively opens a new area of interest for subsequent research and development efforts.
Dostawca treści:: Biblioteka Nauki

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na półce

Skocz do pozycji: 9.

Tytuł:: Influence of Strong Acoustic Anisotropy on Reflection of Bulk Acoustic Waves in Crystals
Autorzy:: Polikarpova, N.
Tematy:: 43.35.Sx
78.20.Hp
43.25.-x
61.72.-y; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1811547.pdf Link otwiera się w nowym oknie
Opis:: Propagation and reflection of plane elastic waves in the acousto-optic crystals tellurium dioxide and calomel as well as in the ferroelectric material barium titanate is examined in the paper. The reflection of the waves from a free and flat boundary separating the crystal and the vacuum is investigated in the (001) planes of $TeO_2$, $Hg_2Cl_2$, and $BaTiO_3$ in the case of glancing acoustic incidence on the boundary. The analysis shows that as much as two elastic waves may be reflected from the crystal surface. Energy flow of one of the reflected waves in paratellurite and calomel propagates in a quasi-back direction with respect to the incident energy flow, so that both energy flows are separated by an angle as narrow as a few degrees. It is found that a relative intensity of the unusually reflected wave in the acousto-optic crystals may be close to a unit in a wide variety of crystal cuts. Possible applications of the examined phenomena in acousto-optic devices are discussed in the presentation.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Swelling, Mechanical and Antimicrobial Studies of Ag/P(HEMA/IA)/PVP Semi-IPN Hydrogel Hybrids
Autorzy:: Jovašević, J.
Dimitrijević, S.
Filipović, J.
Tomić, S.
Mićić, M.
Suljovrujić, E.
Tematy:: 36.20.Fz
82.35.Jk
81.05.Qk
81.05.Lg
61.25.hp
82.35.-x
62.20.-x
81.70.Bt; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1503410.pdf Link otwiera się w nowym oknie
Opis:: A simple and fast approach to the design and production of new hybrid polymeric biomaterials with silver particles is presented in this work. Silver/semi-interpenetrating network hybrid hydrogels (Ag/semi-IPNHHs) were prepared through an optimized solution crosslinking copolymerization of 2-hydroxyethyl methacrylate (HEMA) and itaconic acid (IA), in the presence of PVP, a silver salt and a reducing "green" agent (Ag/P(HEMA/IA)/PVP). PVP was chosen due to its protective, reduction, and nucleation properties in the production of metal particles. The structure of the Ag/semi-IPNHH was characterized by Fourier transform infrared spectroscopy (FTIR). The presence of silver and PVP in the network was confirmed by FTIR spectra. The results obtained by dynamic mechanical analysis (DMA) showed good mechanical properties for all samples. The swelling studies of Ag/P(HEMA/IA)/PVP were conducted in the temperature range of 25-55°C, in the buffer of pH 7.40. The Ag/semi-IPNHH showed temperature-sensitive swelling properties, with the lower critical solution temperature (LCST) values in the physiologically interesting interval. The antimicrobial activity of the samples was tested using E. coli, S. aureus and C. albicans pathogens. It was concluded that the antimicrobial potential depends on the hydrogel's composition and the type of microbes
Dostawca treści:: Biblioteka Nauki

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