Multi-component gap solitons in spinor Bose-Einstein condensates

We model the nonlinear behaviour of spin-1 Bose-Einstein condensates (BECs) with repulsive spin-independent interactions and either ferromagnetic or anti-ferromagnetic (polar) spin-dependent interactions, loaded into a one-dimensional optical lattice potential. We show that both types of BECs exhibit dynamical instabilities and may form spatially localized multi-component structures. The localized states of the spinor matter waves take the form of vector gap solitons and self-trapped waves that exist only within gaps of the linear Bloch-wave band-gap spectrum. Of special interest are the nonlinear localized states that do not exhibit a common spatial density profile shared by all condensate components, and consequently cannot be described by the single mode approximation (SMA), frequently employed within the framework of the mean-field treatment. We show that the non-SMA states can exhibits Josephson-like internal oscillations and self-magnetisation, i.e. intrinsic precession of the local spin. Finally, we demonstrate that non-stationary states of a spinor BEC in a lattice exhibit coherent undamped spin-mixing dynamics, and that their controlled conversion into a stationary state can be achieved by the application of an external magnetic field.Comment: 12 pages, 13 figure

A tale of Public libraries in Bulgaria, Poland, and Romania: The case of three Gates Foundation grants

The Global Library (GL) initiative at the Bill & Melinda Gates Foundation supports public libraries as engines for individual and community development. Funding enhances access to information through publically available information technology in libraries. This technology is complemented by the provision of training and content to make it accessible and useful, and by impact assessment and advocacy to make the new services sustainable. GL has supported library modernization programs at scale in fourteen countries around the world. Based on findings on library perceptions, use, and impact from recent GL research across seventeen European Union (EU) member states, this paper focuses on projects in Bulgaria, Poland, and Romania. It offers a sense of how libraries in these countries have changed during the grant periods, presents key results obtained, and sets out prospects for the future. These prospects include greater attention paid by the EU to the increasingly important role that libraries can play in strengthening communities and improving people’s lives.published or submitted for publicatio

Influence of Cr-substitution on the electrical properties of Fe1-xCrxVSbO6

Fe1xCrxVSbO6 solid solution is semiconductor with the activation energy decreasing both in the intrinsic and extrinsic conductivity temperature regions as the Cr-content increases. The n-type conduction is observed for Fe-richer samples while a change of the Seebeck coe cient (from n to p) for Cr-richer ones. Magnetic isotherms for all samples of solid solution under study are characteristic of the universal Brillouin function, indicating paramagnetic response. These e ects are discussed within the framework of the appearance of the mixed valence of both Fe and Cr ions

Influence of Cr-substitution on the electrical properties of Fe1-xCrxSnSbO6

Fe1xCrxSnSbO6 solid solution shows semiconducting behaviour with the activation energy decreasing from EA = 0:64 eV for x = 0:0 to EA = 0:32 eV for x = 1:0 in the intrinsic conductivity temperature region as well as the n-type conduction at room temperature. The I–V characteristics and the conductance G at 300 and 400 K showed symmetrical and nonlinear behavior in the voltage range (–100, 100 V) suggesting the electron emission over the potential barrier especially for the boundary compounds FeSnSbO6 and CrSnSbO6. These effects are discussed in the context of the energy gap Eg > 1:6 eV many times greater than the thermal energy kT

Effect of tantalum substitution on dielectric constant of ZnSb2-xTaxO6 solid solution (x=0.0,0.1,0.25,0.75,1.6)

The electrical measurements of ZnSb2xTaxO6 phases with x = 0:0; 0:1; 0:25; 0:75; 1:6 have revealed insulating behavior with strongly decreasing electrical conductivity when tantalum x content is increased. As a consequence, high values of relative permittivity "r and loss tangent tan( ) were observed, that decreased with increase of temperature and frequencies, for samples with low Ta content, below x = 0:75. In turn, for samples richer in tantalum, "r reaches 14, and tan( ) becomes as low as 0.02 for x = 1:6. These effects have been interpreted either by the framework of the relaxation processes, or by the spatial charge polarization leading to the low energy loss of materials

Semiconducting properties of Cu5SbO6

Thermoelectric power, electrical resistivity, I V characteristics, relative electrical permittivity, dc magnetization and ac magnetic susceptibility measurements carried out on Cu5SbO6 showed p-type semiconducting behaviour with the activation energy of 0.24 eV as well as ferrimagnetic order with the Néel temperature of 5.2 K. The e ective magnetic moment of 5.857 B/f.u. revealed the orbital contribution to the magnetic moment. Large value of the relative electrical permittivity indicated that the Cu2+ ions with the unscreened and un lled electron shells are responsible for the polarizability and forming of electric dipoles

Discriminative characteristics of marginalised novel psychoactive users: A transnational study

New psychoactive substances (NPS) continue to be considered as a major public health concern in many European countries. The study was implemented within the framework of a transnational project of six European countries (Germany, Hungary, Ireland, Netherlands, Poland, Portugal). Our aim here is to report on the distinct and differentiating characteristics of marginalised NPS users. Three subgroups of a total of 3023 adult NPS users (socially marginalised, night life, online community) were examined regarding their socio-demographic characteristics, substance use, and external motives towards NPS use. Poland and Hungary reported higher rates of NPS use in comparison to traditional controlled drugs. The external/contextual motives did not play a central role in the background of NPS use, the least important motives were alleged legality and non-detectability of these substances. Marginalised (defined as those accessing low threshold harm reduction services) users’ substance use patterns are different from the other two groups in terms of showing more intense and riskier drug use. The most important variables which contributed to be categorised as a marginalised NPS user were lower level education, being older, having an unfavourable labour market position and using drugs intravenously. Contextual motives did not play a decisive role in being categorised as a marginalised user when drug use pattern was controlled. These identified discriminative features of marginalised drug users should inform policy makers to develop and implement tailor-made interventions targeting this user group to successfully tackle the elevated public health concerns associated with NPS use

Asbestos abatement workers versus asbestos workers: Exposure and health-effects differ

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