Resonance in-plane magnetic field effect as a means to reveal the Fulde-Ferrell-Larkin-Ovchinnikov state in layered superconductors

International audienceThe vector potential of a parallel magnetic field produces a modulation of the interlayer coupling between adjacent superconducting layers. In some cases the period of this modulation can coincide with the period of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) modulation of the superconducting order parameter. Such a resonance condition results in cusps on the temperature and in-plane angular dependencies of the upper critical field Hc2. This effect can open up a possibility to unambiguously evidence a spatially modulated superconducting phase in layered conductors. Remarkably, the proposed signature of the FFLO state is directly based on the main feature of the FFLO state, the spatial modulations of the order parameter

Field-Direction Dependence of the Upper Critical Field in Organic Superconductors

International audienceIn this work, we investigate the anisotropy of the in-plane critical field in conventional and spatially modulated phases of layered superconductors within the quasi-classical approach, taking into account the interlayer Josephson coupling. We show that the anisotropy of the onset of superconductivity may change dramatically in the FFLO state as compared with the conventional superconducting phase

Quantum cascades in nano-engineered superconductors: geometrical, thermal and paramagnetic effects

International audienceThe effect of a parallel magnetic field on the orbital motion of electrons in high-quality superconducting nanowires resulting in a superconductor-to-normal transition which occurs through a cascade of jumps in the order parameter as a function of the magnetic field. Such cascades originate from the transverse size quantization that splits the conduction band into a series of subbands. Here, based on a numerical solution of the Bogoliubov-de Gennes equations for a hollow nanocylinder, we investigate how the quantum-size cascades depend on the confining geometry, i.e., by changing the cylinder radius R and its thickness d we cover the range from the nanowire-like to the nanofilm-like regime. The cascades are shown to become much less pronounced when increasing R=d, i.e., when the nanofilm-like regime is approached. When the temperature is non-zero they are thermally smoothed. This includes the spin-magnetic-field interaction which reduces the critical (depairing) parallel magnetic field Hc;k but does not have any qualitative effect on the quantum cascades. From our calculations it is seen that the paramagnetic limiting field Hpar significantly exceeds Hc;k even in extremely narrow nanocylinders, i.e., when R; d are down to a few nanometers, and Hc;k is only about 10% larger when switching-off the spin-magnetic-field interaction in this case. Both characteristic fields, Hc;k and Hpar, exhibit pronounced quantum-size oscillations. We demonstrate that the quantum cascades and the quantum-size oscillations survive in the presence of surface roughness

Degradation of earth’s dams under the effect of climate change

The paper presents a summary analysis of the phenomena of the degradation of earth dams by the action of changing climate conditions in the eastern part of Romania. Climate change over the last 30 years has led to hydrological risks in the hydrographic network, represented by rapid, frequent flash floods over short periods of time. The floods are due to the uneven distribution of rainfall over the year. The floods are concentrated in a short time and have a very high intensity. This is a major cause of the degradation of dams. Most damage occurs due to floods associated with structural faults, mechanical faults, or hydraulic faults. This situation is confirmed by the events that have taken place over the last 30 years at a series of earth dams in Suceava county (eg. Crujana, Grănicești, Horodnic etc.). The destructive actions were manifested by structural degradations to the dam body, to the large water drain, to the bottom emptying, to the drainage system, etc. In order to prevent adverse events, the term "safety" of hydrotechnical constructions must be taken into account at all stages of the design, execution and operation work. In order to prevent possible accidents that could occur through a dam failure, tests and models shall be carried out in specialized programs

Cercetări privind degradarea mediului în zonele de ramificare a albiilor de râu

The conservation of the ecological system of riverbeds is a necessity for ensuring the living conditions of the aquatic and riparian habitat. A number of special problems are imposed by the riverbed branches where an island is created. The research carried out on the lower course of the Moldova River, where the riverbed was artificially branched (Cordunarea, NeamţCounty) highlighted the need for a set of works on ecological restoration of the aquatic and riparian environment. The presence of economic disturbances in these areas(water capture)has led to significant morphological changes on the two arms of the Moldova River. The aquatic vegetation is almost completely degraded on the active arm of the river. The secondary arm of the riverbed has a variable flow over time, a situation that generates unviable living conditions for the habitat

Design of GNSS networks for monitoring earth dams deformations

The paper presents a series of results regarding the application of GNSS technology for measuring displacements to earth dams. An appropriate horizontal and vertical deformation-tracking network must be established for the rapid monitoring of earthmoving movements. Data obtained from the monitoring network can be used in the earth dam stability analysis program. Periodic tracking of earth dams using GNSS technology provides high accuracy of spatial distortions. The results of the paper show the application of GNSS technology to monitor the deformations of the Podisu earth dam located on the Sheep Valley River in Iasi County. In the first stage of research (2019 and 2020), the local geodetic tracking network was created. To monitor the dam, four control landmarks were placed on the crest of dam and seven landmarks on the downstream slope. In the second stage of the research (year 2021) the measurements of the displacements at the earth dam were performed. The GNSS monitoring method has the advantage of positioning the target quickly, statically, and with high accuracy. The measurements used fixed stations located at two points in the local geodetic network. Four Trimble GNSS receivers were used for the measurements. The resulting data was processed using the Trimble Business Centre program. The obtained results were analysed in comparison with those existing in the design documentation and technical expertise of the dam. The results highlight the presence of displacements on the crest of a dam and slopes of the dam. The final findings highlight the performance of GNSS technology in the monitoring process, where it provides millimetre-accurate accuracy with high spatial and temporal accuracy

Endoprotezarea de reluare a şoldului în destabilizările cotiloidiene

Autorii expun propria experienţă în endoprotezarea de revizie a componentului acetabular pentru o destabilizare aseptică. Au fost operaţi 37 de pacienţi la care destabilizarea componentului acetabular a survenit la o perioadă de la 2,5 până la 12 ani postoperator. Defectele periacetabulare au fost apreciate după W.G. Paprosky. În defectele de tip 3 autorii propun o metodă originală de plastie osoasă

Utilizarea computerului şi reacţia sistemului neuro-muscular

USMF "Nicolae Testemitanu", Centrul National Stiintifico-Practic Medicina Preventiva, Centru de medicina preventiva EdinetIn the majority of cases pupils who use PC after high frequency of Physiological tremors to the end of every lessons was registered. The dynamics of high frequency is keeping during the whole week. În majoritatea cazurilor la elevii care utilizeaza computerul în afara orelor scolare se evidentiaza o crestere a tremorului fiziologic spre sfârsitul fiecarei lectii. Dinamica rezultatelor tremorului fiziologic se mentine stabila pe parcursul întregii saptamâni

Rezistența la antimicrobiene: amenințare globală pentru sănătatea publică

Ghidul a fost realizat cu suportul proiectului multilateral 22.80013.8007.1M „Phage treatment and wetland technology as intervention strategy to prevent dissemination of antibiotic resistance in surface waters (PhageLand)” din cadrul JPIAMR-ACTION 2021 (2022-2025), Coordonator național Alina Ferdohleb