62 research outputs found
Hydrothermal synthesis of zeolites from coal fly ash
The fly ash, from the combustion of coal to produce energy and heat, is an industrial waste, in which large accumulations represent a serious environmental threat. To reduce the environmental burden and improve the economic benefits of energy production, the science and industry focus on the transformation of coal combustion byproducts into new functional materials. The fly ash was studied by modern analytical methods. As a result of the hydrothermal reaction, several types of zeolites were synthesised from the fly ash: analcime, faujasite (zeolite X) and gismondine (zeolite P). It was shown that the experimental conditions (temperature, reaction time and alkali concentration) have a significant influence on the type of zeolite and its content in the reaction products. The series of experiments resulted in building approximate crystallisation field of zeolites and other phases as the first stage of the formation of ceramic membrane and other materials
Motivation to learn foreign languages among linguistics students (socio-cultural aspect)
Целью данного исследования является изучение формирования мотивации студентов направления 45.03.02 «Лингвистика» УрФУ им. Б. Н. Ельцина, а также группы иностранных студентов в социокультурном аспекте. Для достижения поставленной цели были проведены опросы, которые отражают факторы, влияющие на формирование внутренней и внешней мотивации студентов. Результаты исследования позволяют сделать вывод о том, что поддержание социокультурного компонента способствует повышению мотивации, развитию потребностей и интересов обучающихся, а также осознанному изучению иностранного языка.The aim of the research is to study the formation of motivation of students of 45.03.02 "Linguistics" of the Ural Federal University named after B. N. Yeltsin, as well as the group of foreign students in the socio-cultural aspect. In order to achieve the set goal, surveys were conducted reflecting the factors influencing the formation of the intrinsic and the extrinsic motivation of students during the process of foreign language learning. The results of the research allow us to conclude that maintaining the socio-cultural component contributes to increasing motivation, developing learners' needs and interests, as well as making the learning of a foreign language more conscious
Restoring the valence-shell stabilization in Nd-140
A projectile Coulomb-excitation experiment was performed at the radioactive-ion beam facility HIE-ISOLDE at CERN to obtain E2 and M1 transition matrix elements of Nd-140 using the multistep Coulomb-excitation code GOSIA. The absolute M1 strengths, B(M1; 2(2)(-) -> 2(1)(+)) = 0.033(8)mu(2)(N), B(M1 ; 2(3)(+) -> 2(1)(+)) = 0.26(-0.10)(+0.11)mu(2)(N), and B(M1; 2(4)+ -> 2(1)(+)) <0.04 mu(2)(N) identify the 2(3)(+) state as the main fragment of the one-quadrupole-phonon proton-neutron mixed-symmetry state of Nd-140. The degree of F-spin mixing in Nd-140 was quantified with the determination of the mixing matrix element VF-mix <7(-7)(-13) keV.Peer reviewe
Search formixed-symmetry states of nuclei in the vicinity of the double-magic nucleus 208Pb
In this work we present the results from two experiments dedicated to search for quadrupolecollective isovector valence-shell excitation, the states with so-called mixed proton-neutron symmetry (MSS), in nuclei around the doubly magic nucleus 208Pb. 212Po was studied in an α-transfer reaction. 204Hg was studied in an inverse kinematics Coulomb excitation reaction on a carbon target. Both experiments provide indications for existence of one-phonon MSSs. Those are the first experimentally identified MSSs in the mass A ≈ 208 region
Direct measurement of the intrinsic electric dipole moment in pear-shaped thorium-228
Atomic nuclei with certain combinations of proton and neutron numbers can adopt reflection-asymmetric or octupole-deformed shapes at low excitation energy. These nuclei present a promising avenue in the search for a permanent atomic electric dipole moment—the existence of which has implications for physics beyond the Standard Model of particle physics. Theoretical studies have suggested that certain thorium isotopes may have large octupole deformation. However, due to experimental challenges, the extent of the octupole collectivity in the low-energy states in these thorium nuclei has not yet been demonstrated. Here, we report measurements of the lifetimes of low-energy states in 228Th (Z = 90) with a direct electronic fast-timing technique, the mirror symmetric centroid difference method. From lifetime measurements of the low-lying Jπ = 1− and Jπ = 3− states, the E1 transition probability rates and the intrinsic dipole moment are determined. The results are in agreement with those of previous theoretical calculations, allowing us to estimate the extent of the octupole deformation of 228Th. This study indicates that the nuclei 229Th and 229Pa (Z = 91) may be good candidates for the search for a permanent atomic electric dipole moment
Lifetime measurements of the low-lying excited states of ²⁰⁸Po
In this study we present the preliminary results about the lifetimes of the 2₂⁺, 4₁⁺ states of ²⁰⁸Po and the upper limit of the lifetime of the 2₁⁺ state. For measuring the lifetimes of the 2₁⁺ and 4₁⁺ states the Recoil Distance Doppler Shift (RDDS) method and for the lifetime of the 2₂⁺ state the Doppler Shift Attenuation method (DSAM) were used. The resulting absolute transition strength B(M1 ; 2₂⁺ → 2₁⁺) ≥ 0.122(20) μN² reveals the predominant isovector nature of the 2₂⁺ state of ²⁰⁸Po
Low collectivity of the 2(1)(+) state of Po-212
International audienceThe lifetime of the state of Po was measured in the Pb(C,Be)Po transfer reaction by γ -ray spectroscopy employing the recoil distance Doppler shift (RDDS) method. The derived absolute B(E2) value of 2.6(3)W.u. indicates a low collectivity and contradicts previous claims of α-cluster components in the structure of the state. It is demonstrated that a consistent description of the properties of the −−− sequence in Po cannot be achieved in the framework of a single-j shell-model calculation, either. This puzzle is traced to the properties of the seniority-2 configurations in Pb and Po
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