4,484 research outputs found
Orbital stability of solutions to the problem on capillary-gravity waves in two-fluid layer
Going back to N. E. Kochin [1] problem about capillary-gravity waves on interface of
two-fluid flow is considered as bifurcation problem with spectral parameters
NbS: A unique quasi one-dimensional conductor with three charge density wave transitions
Through transport, compositional and structural studies, we review the
features of the charge-density wave (CDW) conductor of NbS (phase II). We
highlight three central results: 1) In addition to the previously reported CDW
transitions at = 360\,K and = 150\,K, another CDW transition
occurs at a much higher temperature = 620-650\,K; evidence for the
non-linear conductivity of this CDW is presented. 2) We show that CDW
associated with the - transition arises from S vacancies acting as
donors. Such a CDW transition has not been observed before. 3) We show
exceptional coherence of the -CDW at room-temperature. Additionally, we
report on the effects of uniaxial strain on the CDW transition temperatures and
transport.Comment: 16 pages, 18 figure
Annihilation of edge dislocations in smectic A liquid crystals
This paper presents a theoretical study of the annihilation of edge dislocations in the same smectic plane in a bulk smectic-A phase. We use a time-dependent Landau-Ginzburg approach where the smectic ordering is described by the complex order parameter psi( r--> ,t) =eta e(iphi) . This quantity allows both the degree of layering and the position of the layers to be monitored. We are able to follow both precollision and postcollision regimes, and distinguish different early and late behaviors within these regimes. The early precollision regime is driven by changes in the phi ( r--> ) configuration. The relative velocity of the defects is approximately inversely proportional to the interdefect separation distance. In the late precollision regime the symmetry changes within the cores of defects also become influential. Following the defect collision, in the early postcollision stage, bulk layer order is approached exponentially in time. At very late times, however, there seems to be a long-time power-law tail in the order parameter fluctuation relaxation
Production of Ions of Metals with an ECR Ion Source at FLNR (JINR) cyclotrons
Two ECR ion sources : DECRIS-14-2 and ECR4M are presently in permanent operation at the FLNR cyclotrons U400M and U400, correspondingly. During last two years the major effort were made in production of high current stable ion beams of solids with the relatively low melting point in the mass range from Li to Bi. Both the evaporator and MIVOC methods were used. Among the solids such an exotic beam as 48Ca was produced at the U400 cyclotron with high efficiency. The main results on production of solid ions will be reported
Comparative Analysis of Properties of the Carbon-Based Coatings Obtained through Various PVD and CVD Deposition Methods
The paper examines carbon 0.5-1 thick coatings obtained through various physical vapour deposition and chemical vapour deposition methods on stainless steel and tool steel substrates. Their composition, morphology and physical properties have also been studied. The correlations of erosive wear resistance and H3/E2 ratio (where H is hardness and E is elastic modulus) have been identified for carbon coatings in regards to the production method. Ta-C carbon coatings demonstrate high resistance to dynamic loads with erosive wear in a sand-blast machine. © Published under licence by IOP Publishing Ltd
Combined antibiotic prophylaxis of infectious complications of prostate biopsy
Introduction. Biopsy of prostate is a routine urologic procedure. Nevertheless the frequency of infectious-inflammatory complications remain high, despite the recommended antibiotic prophylaxis schemes.Purpose. The evaluation of effectiveness and safety of combined antimicrobial prophylaxis: fosfomycin trometamol and fluoroquinolones of 3rd generation.Materials and methods. Our clinical study included 80 patients who underwent prostate biopsy were divided into 2 groups. The first group of 40 patients received routine prophylaxis: levofloxacin 500 mg 6 h before the biopsy and 500 mg per day during 4 days after biopsy. The second group of 40 patients, along with standard prophylaxis as in the first group, additionally after biopsy received fosfomycin trometamol 3 gr single-shot.Results. In the first group, infectious and inflammatory complications occurred in 8 (20 %) patients, 12.5 % of patients from the first group were hospitalized for parenteral antibiotic therapy. The average length of stay in hospital was 3.4 ± 1.45 days. In all cases, in the first group of patients, Escherichia coli was detected, in 70 % of cases fluoroquinolone-resistant strain of the bacterium was received. In the second group of patients no hospitalization was required. One (2.5 %) patient out of forty from this group showed signs of urinary tract infection, which was not accompanied by an increase of body temperature, as well as changes in blood and urine tests.Conclusions. Our results show good effectiveness and safety of combined antibiotic prophylaxis for transrectal prostate biopsy. Since fluoroquinolone resistance grows, it is necessary to introduce alternative schemes, as well as monitoring of nosocomial infection and controlling of antimicrobial therapy
Phase formation and relaxor properties of lead-free perovskite ceramics on the base of sodium-bismuth titanate
The work was supported by the Russian Foundation for Basic Research (Projects 16-53-48009, 17-03-00542)
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