Institute of Nuclear Physics
facilityTashkent, Uzbekistan
Research output, citation impact, and the most-cited recent papers from Institute of Nuclear Physics (Uzbekistan). Aggregated across the NobleBlocks index of 300M+ scholarly works.
Top-cited papers from Institute of Nuclear Physics
Abstract The joint evaluated fission and fusion nuclear data library 3.3 is described. New evaluations for neutron-induced interactions with the major actinides $$^{235}\hbox {U}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow/><mml:mn>235</mml:mn></mml:msup><mml:mtext>U</mml:mtext></mml:mrow></mml:math> , $$^{238}\hbox {U}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow/><mml:mn>238</mml:mn></mml:msup><mml:mtext>U</mml:mtext></mml:mrow></mml:math> and $$^{239}\hbox {Pu}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow/><mml:mn>239</mml:mn></mml:msup><mml:mtext>Pu</mml:mtext></mml:mrow></mml:math> , on $$^{241}\hbox {Am}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow/><mml:mn>241</mml:mn></mml:msup><mml:mtext>Am</mml:mtext></mml:mrow></mml:math> and $$^{23}\hbox {Na}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow/><mml:mn>23</mml:mn></mml:msup><mml:mtext>Na</mml:mtext></mml:mrow></mml:math> , $$^{59}\hbox {Ni}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow/><mml:mn>59</mml:mn></mml:msup><mml:mtext>Ni</mml:mtext></mml:mrow></mml:math> , Cr, Cu, Zr, Cd, Hf, W, Au, Pb and Bi are presented. It includes new fission yields, prompt fission neutron spectra and average number of neutrons per fission. In addition, new data for radioactive decay, thermal neutron scattering, gamma-ray emission, neutron activation, delayed neutrons and displacement damage are presented. JEFF-3.3 was complemented by files from the TENDL project. The libraries for photon, proton, deuteron, triton, helion and alpha-particle induced reactions are from TENDL-2017. The demands for uncertainty quantification in modeling led to many new covariance data for the evaluations. A comparison between results from model calculations using the JEFF-3.3 library and those from benchmark experiments for criticality, delayed neutron yields, shielding and decay heat, reveals that JEFF-3.3 performes very well for a wide range of nuclear technology applications, in particular nuclear energy.
Evaluated atomic subshell and relaxation data for isolated neutral atoms are given in tabular and graphical form for elements H through Fm (Z=1 - 100). These data include fluorescence yields, subshell parameters (e.g., binding energies), both radiative and nonradiative transition probabilities, as well as energy deposition terms. This information is derived from the Livermore Evaluated Atomic Data Library (EADL) as of July, 1991.
We study the shadows cast by the different types of rotating regular black holes viz. Ay\'on-Beato-Garc\'{\i}a (ABG), Hayward, and Bardeen. These black holes have in addition to the total mass ($M$) and rotation parameter ($a$), different parameters as electric charge ($Q$), deviation parameter ($g$), and magnetic charge (${g}_{*}$). Interestingly, the size of the shadow is affected by these parameters in addition to the rotation parameter. We found that the radius of the shadow in each case decreases monotonically, and the distortion parameter increases when the values of these parameters increase. A comparison with the standard Kerr case is also investigated. We have also studied the influence of the plasma environment around regular black holes to discuss its shadow. The presence of the plasma affects the apparent size of the regular black hole's shadow to be increased due to two effects: (i) gravitational redshift of the photons and (ii) radial dependence of plasma density.
We report the first measurements of the kurtosis ($\ensuremath{\kappa}$), skewness ($S$), and variance (${\ensuremath{\sigma}}^{2}$) of net-proton multiplicity (${N}_{p}\ensuremath{-}{N}_{\overline{p}}$) distributions at midrapidity for $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{{s}_{NN}}=19.6$, 62.4, and 200 GeV corresponding to baryon chemical potentials (${\ensuremath{\mu}}_{B}$) between 200 and 20 MeV. Our measurements of the products $\ensuremath{\kappa}{\ensuremath{\sigma}}^{2}$ and $S\ensuremath{\sigma}$, which can be related to theoretical calculations sensitive to baryon number susceptibilities and long-range correlations, are constant as functions of collision centrality. We compare these products with results from lattice QCD and various models without a critical point and study the $\sqrt{{s}_{NN}}$ dependence of $\ensuremath{\kappa}{\ensuremath{\sigma}}^{2}$. From the measurements at the three beam energies, we find no evidence for a critical point in the QCD phase diagram for ${\ensuremath{\mu}}_{B}$ below 200 MeV.
The shadow of a rotating non-Kerr black hole has been studied, and it was shown that in addition to the specific angular momentum $a$, the deformation parameter of non-Kerr spacetime essentially deforms the shape of the black hole shadow. For a given value of the black hole spin parameter $a$, the presence of a deformation parameter $ϵ$ reduces the shadow and enlarges its deformation with respect to the one in the Kerr spacetime. Optical features of the rotating non-Kerr black hole in terms of rotation of the polarization vector along null congruences have been studied. A comparison of the obtained theoretical results on the polarization angle with the observational data on Faraday rotation measurements provides the upper limit for the dimensionless deformation parameter as $ϵ\ensuremath{\le}19$.
The atomic nucleus is composed of two different kinds of fermions: protons and neutrons. If the protons and neutrons did not interact, the Pauli exclusion principle would force the majority of fermions (usually neutrons) to have a higher average momentum. Our high-energy electron-scattering measurements using (12)C, (27)Al, (56)Fe, and (208)Pb targets show that even in heavy, neutron-rich nuclei, short-range interactions between the fermions form correlated high-momentum neutron-proton pairs. Thus, in neutron-rich nuclei, protons have a greater probability than neutrons to have momentum greater than the Fermi momentum. This finding has implications ranging from nuclear few-body systems to neutron stars and may also be observable experimentally in two-spin-state, ultracold atomic gas systems.
are illustrated with the Cole-Cole diagram. The enhanced microwave absorbing properties can be ascribed to the high dielectric loss accompanied with the strong multi-reflections between MXene layers.
Abstract A stabilization procedure is developed for controlling the kinematic modes of the four‐node, bilinear quadrilateral element when single‐point quadrature is used. These kinematic modes manifest themselves by spatial oscillations or singularity of the total stiffness. In this stabilization procedure, additional generalized strains are defined which are activated by the kinematic modes; these generalized modes are furthermore not activated by rigid body motions regardless of the shape of the quadrilateral. By using a scaling law developed in an earlier paper, the stabilization parameters are defined so they do not adversely affect the element's performance. Several problems which are subject to kinematic modes are presented to illustrate the performance of this stabilization procedure for linear problems.
The time evolution of the entanglement entropy in non-equilibrium quantum systems provides crucial information about the structure of the time-dependent state. For quantum quench protocols, by combining a quasiparticle picture for the entanglement spreading with the exact knowledge of the stationary state provided by Bethe ansatz, it is possible to obtain an exact and analytic description of the evolution of the entanglement entropy. Here we discuss the application of these ideas to several integrable models. First we show that for non-interacting systems, both bosonic and fermionic, the exact time-dependence of the entanglement entropy can be derived by elementary techniques and without solving the dynamics. We then provide exact results for interacting spin chains that are carefully tested against numerical simulations. Finally, we apply this method to integrable one-dimensional Bose gases (Lieb-Liniger model) both in the attractive and repulsive regimes. We highlight a peculiar behaviour of the entanglement entropy due to the absence of a maximum velocity of excitations.
A black hole casts a shadow as an optical appearance because of its strong gravitational field. We study the shadow cast by the five-dimensional Myers-Perry black hole with equal rotation parameters. We demonstrate that the null geodesic equation can be integrated, which provides us an opportunity to investigate the shadow cast by a black hole. The shadow of a black hole is found to be a dark zone covered by a deformed circle. Interestingly, the shapes of the black hole shadow are more distorted and the size decreases for larger black hole spins. Interestingly, it turns out that, for fixed values of the rotation parameter, the shadow is slightly smaller and less deformed than for its four-dimensional Kerr black hole counterpart. Further, the shadow of the five-dimensional Kerr black hole is concentric deformed circles. The effect of the rotation parameter on the shape and size of a naked singularity shadow is also analyzed.
Solution phase room-temperature phosphorescence (RTP) from organic phosphors is seldom realized. Herein we report one of the highest quantum yield solution state RTP (ca. 41.8 %) in water, from a structurally simple phthalimide phosphor, by employing an organic-inorganic supramolecular scaffolding strategy. We further use these supramolecular hybrid phosphors as a light-harvesting scaffold to achieve delayed fluorescence from orthogonally anchored Sulforhodamine acceptor dyes via an efficient triplet to singlet Förster resonance energy transfer (TS-FRET), which is rarely achieved in solution. Electrostatic cross-linking of the inorganic scaffold at higher concentrations further facilitates the formation of self-standing hydrogels with efficient RTP and energy-transfer mediated long-lived fluorescence.
Based on the Newman-Janis algorithm, the Ay\'on-Beato-Garc\'{\i}a spacetime metric [Phys. Rev. Lett. 80, 5056 (1998)] of the regular spherically symmetric, static, and charged black hole has been converted into rotational form. It is shown that the derived solution for rotating a regular black hole is regular and the critical value of the electric charge for which two horizons merge into one sufficiently decreases in the presence of the nonvanishing rotation parameter $a$ of the black hole.
The fusion-evaporation reaction $^{244}\mathrm{Pu}(^{48}\mathrm{Ca},3\mathrm{\text{\ensuremath{-}}}4n)^{288,289}114$ was studied at the new gas-filled recoil separator TASCA. Thirteen correlated decay chains were observed and assigned to the production and decay of $^{288,289}114$. At a compound nucleus excitation energy of ${E}^{*}=39.8--43.9\text{ }\text{ }\mathrm{MeV}$, the $4n$ evaporation channel cross section was ${9.8}_{\ensuremath{-}3.1}^{+3.9}\text{ }\text{ }\mathrm{pb}$. At ${E}^{*}=36.1--39.5\text{ }\text{ }\mathrm{MeV}$, that of the $3n$ evaporation channel was ${8.0}_{\ensuremath{-}4.5}^{+7.4}\text{ }\text{ }\mathrm{pb}$. In one of the $3n$ evaporation channel decay chains, a previously unobserved $\ensuremath{\alpha}$ branch in $^{281}\mathrm{Ds}$ was observed (probability to be of random origin from background: 0.1%). This $\ensuremath{\alpha}$ decay populated the new nucleus $^{277}\mathrm{Hs}$, which decayed by spontaneous fission after a lifetime of 4.5 ms.
Conformal field theory (CFT) has been extremely successful in describing large-scale universal effects in one-dimensional (1D) systems at quantum critical points. Unfortunately, its applicability in condensed matter physics has been limited to situations in which the bulk is uniform because CFT describes low-energy excitations around some energy scale, taken to be constant throughout the system. However, in many experimental contexts, such as quantum gases in trapping potentials and in several out-of-equilibrium situations, systems are strongly inhomogeneous. We show here that the powerful CFT methods can be extended to deal with such 1D situations, providing a few concrete examples for non-interacting Fermi gases. The system's inhomogeneity enters the field theory action through parameters that vary with position; in particular, the metric itself varies, resulting in a CFT in curved space. This approach allows us to derive exact formulas for entanglement entropies which were not known by other means.
The importance of personalized medicine has been growing, mainly due to a more urgent need to avoid unnecessary and expensive treatments. In nuclear medicine, the theranostic approach is an established tool for specific molecular targeting, both for diagnostics and therapy. The visualization of potential targets can help predict if a patient will benefit from a particular treatment. Thanks to the quick development of radiopharmaceuticals and diagnostic techniques, the use of theranostic agents has been continually increasing. In this article, important milestones of nuclear therapies and diagnostics in the context of theranostics are highlighted. It begins with a well-known radioiodine therapy in patients with thyroid cancer and then progresses through various approaches for the treatment of advanced cancer with targeted therapies. The aim of this review was to provide a summary of background knowledge and current applications, and to identify the advantages of targeted therapies and imaging in nuclear medicine practices.
We have studied photon motion around axially symmetric rotating Kerr black holes in the presence of a plasma with radial power-law density. It is shown that in the presence of a plasma, the observed shape and size of the shadow changes depending on the (i) plasma parameters, (ii) black hole spin, and (iii) inclination angle between the observer plane and the axis of rotation of the black hole. In order to extract the pure effect of the plasma influence on the black hole image, the particular case of the Schwarzschild black hole has also been investigated and it has been shown that the photon sphere around the spherically symmetric black hole is left unchanged under the plasma influence; however, the Schwarzschild black hole shadow size in the plasma is reduced due to the refraction of the electromagnetic radiation in the plasma environment of the black hole. The study of the energy emission from the black hole in plasma environment shows that in the presence of the plasma the maximal energy emission rate from the black hole decreases.
A large international effort is under way to assess the presence of a shadow in the radio emission from the compact source at the centre of our Galaxy, Sagittarius A * (Sgr A * ). If detected, this shadow would provide the first direct evidence of the existence of black holes and that Sgr A * is a supermassive black hole. In addition, the shape of the shadow could be used to learn about extreme gravity near the event horizon and to determine which theory of gravity better describes the observations. The mathematical description of the shadow has so far used a number of simplifying assumptions that are unlikely to be met by the real observational data. We here provide a general formalism to describe the shadow as an arbitrary polar curve expressed in terms of a Legendre expansion. Our formalism does not presume any knowledge of the properties of the shadow, e.g. the location of its centre, and offers a number of routes to characterize the distortions of the curve with respect to reference circles. These distortions can be implemented in a coordinate-independent manner by different teams analysing the same data. We show that the new formalism provides an accurate and robust description of noisy observational data, with smaller error variances when compared to previous approaches for the measurement of the distortion.
A new procedure is developed for calculating the charge, mass, and kinetic energy distributions of quasifission products. The quasifission is treated within a transport model which describes a master equation for the evolution of the dinuclear system in charge and mass asymmetries and its decay along the internuclear distance. The calculated yields of quasifission products and their distributions in kinetic energy are in agreement with recent experimental data of hot fusion reactions leading to superheavy nuclei. The importance of shell and deformation effects in quasifission is noted. The preneutron and postneutron emissions as well as the fission of a heavy nucleus in the dinuclear system are considered.
The preliminary results described here show that the adsorbability of uranyl ions by a highly stable MOF UiO-66 can be drastically enhanced by tailoring the missing-linker defects in this MOF. The combination of defect-induced functionality improvement with the acid-resistant nature of UiO-66 substantiates the applicability of this material for actinide capture from acidic media.
PURPOSE: We prospectively examined the role of tumor textural heterogeneity on positron emission tomography/computed tomography (PET/CT) in predicting survival compared with other clinical and imaging parameters in patients with non-small cell lung cancer (NSCLC). EXPERIMENTAL DESIGN: The feasibility study consisted of 56 assessed consecutive patients with NSCLC (32 males, 24 females; mean age 67 ± 9.7 years) who underwent combined fluorodeoxyglucose (FDG) PET/CT. The validation study population consisted of 66 prospectively recruited consecutive consenting patients with NSCLC (37 males, 29 females; mean age, 67.5 ± 7.8 years) who successfully underwent combined FDG PET/CT-dynamic contrast-enhanced (DCE) CT. Images were used to derive tumoral PET/CT textural heterogeneity, DCE CT permeability, and FDG uptake (SUVmax). The mean follow-up periods were 22.6 ± 13.3 months and 28.5± 13.2 months for the feasibility and validation studies, respectively. Optimum threshold was determined for clinical stage and each of the above biomarkers (where available) from the feasibility study population. Kaplan-Meier analysis was used to assess the ability of the biomarkers to predict survival in the validation study. Cox regression determined survival factor independence. RESULTS: Univariate analysis revealed that tumor CT-derived heterogeneity (P < 0.001), PET-derived heterogeneity (P = 0.003), CT-derived permeability (P = 0.002), and stage (P < 0.001) were all significant survival predictors. The thresholds used in this study were derived from a previously conducted feasibility study. Tumor SUVmax did not predict survival. Using multivariable analysis, tumor CT textural heterogeneity (P = 0.021), stage (P = 0.001), and permeability (P < 0.001) were independent survival predictors. These predictors were independent of patient treatment. CONCLUSIONS: Tumor stage and CT-derived textural heterogeneity were the best predictors of survival in NSCLC. The use of CT-derived textural heterogeneity should assist the management of many patients with NSCLC.