Large temperature dependence of the Casimir force at the metal-insulator transition

The dependence of the Casimir force on material properties is important for both future applications and to gain further insight on its fundamental aspects. Here we derive a general theory of the Casimir force for low-conducting compounds, or poor metals. For distances in the micrometer range, a large variety of such materials is described by universal equations containing a few parameters: the effective plasma frequency, dissipation rate of the free carriers, and electric permittivity in the infrared range. This theory can also describe inhomogeneous composite materials containing small regions with different conductivity. The Casimir force for mechanical systems involving samples made with compounds that have a metal-insulator transition shows an abrupt large temperature dependence of the Casimir force within the transition region, where metallic and dielectric phases coexist.Comment: 23 pages, 9 figure

Properties of coatings based on carbon and nitrogen-doped carbon obtained using a pulsed vacuum arc method

Diamond-like carbon coatings on hard-alloy substrates, including coatings doped with nitrogen about 1.0 μm thick have been obtained using a pulse vacuum-arc method. Three types of coatings have been investigated: a carbon diamond-like coating (C), a carbon coating doped with nitrogen (C : N), and a composite coating based on (C : N + C) layer

Phase changes of the Be/X-ray binary X Persei

We present high resolution optical spectroscopy and V band photometry obtained during the period 1987-2001 for the Be star X Persei/HD 24534, the counterpart to the X-ray pulsar 4U 0352+30. We find that throughout this interval X Per is highly active, with significant photometric and spectroscopic variability. We identify one episode of complete disc loss during this period (1988 May-1989 June), characterised by significant ΔV=0.6 mag optical fading and the presence of purely photospheric Hα and He I 6678 Å lines. Two further episodes of pronounced optical fading which did not result in the complete dispersal of the circumstellar disc were also identified (1994 October-1995 October and 1999 November-present). The emission line profiles of both Hα and He I 6678 Å also show significant variability. Cyclic changes in the strength of the peaks in both emission lines are observed, with periods ranging from 0.6-2 yrs - we attribute these to the presence of a one armed density wave in the inner circumstellar disc. Additional structure at large projected velocities is also present in the He I line - suggesting the presence of a significant density enhancement in the disc near the stellar surface (the "double disc'' of Tarasov & Roche). The evolution of the outer edge of the Hα emitting region of the circumstellar disc is followed during disc formation, and is found to increase rather slowly. This observation, combined with the presence of the one armed density wave and the rate of disc formation and loss all provide strong evidence for the hypothesis that the circumstellar disc of X Per is a viscous decretion disc, with angular momentum being supplied by an as yet unknown physical mechanism near the stellar surface

Chirality tunneling in mesoscopic antiferromagnetic domain walls

We consider a domain wall in the mesoscopic quasi-one-dimensional sample (wire or stripe) of weakly anisotropic two-sublattice antiferromagnet, and estimate the probability of tunneling between two domain wall states with different chirality. Topological effects forbid tunneling for the systems with half-integer spin S of magnetic atoms which consist of odd number of chains N. External magnetic field yields an additional contribution to the Berry phase, resulting in the appearance of two different tunnel splittings in any experimental setup involving a mixture of odd and even N, and in oscillating field dependence of the tunneling rate with the period proportional to 1/N.Comment: 4 pages + 2 figures, references correcte

Properties of carbon coatings obtained by pulsed high power methods of vacuum-arc and magnetron sputtering

Investigation results of the structure, mechanical, tribological and adhesion characteristics of carbon coatings obtained by two different methods: high-power impulse magnetron sputtering and pulsed cathodic arc deposition are presente

Doxorubicin pharmacokinetics in lymphoma patients treated with doxorubicin-loaded eythrocytes

Doxorubicin-loaded erythrocytes (DLE) were administrated to 15 lymphoma patients. Antibiotic peak concentration in blood decreased by 55%, doxorubicin circulated several times longer, and the area under the concentration-time curve increased 5 times if compared with standard doxorubicin administration. The DLE was well tolerated by patients

The local crystallization in nanoscale diamond-like carbon films during annealing

The local crystallization during annealing at 600° C in nanoscale diamond-like carbon coatings films grown by pulsed vacuum-arc deposition method was observed using modern techniques of high-resolution transmission electron microscopy. The crystallites formed by annealing have a face-centred cubic crystal structure and grow in the direction [011] as a normal to the film surface. The number and size of the crystallites depend on the initial values of the intrinsic stresses before annealing, which in turn depend on the conditions of film growth. The sizes of crystallites are 10 nm for films with initial compressive stresses of 3 GPa and 17 nm for films with initial compres- sive stresses of 12 GPa. Areas of local crystallization arising during annealing have a structure dif- ferent from the graphit

К вопросу о придании статуса резервной валюты юаню

The presented article opens an essence of internationalization of currency, defines, what factors are necessary in order that the Yuan became the international currency, pays the main attention to international payments which are carried out by means of Yuan, in particular, analyzes prospects of the investments expressed in Yuan.Представленная статья раскрывает суть понятия «интернационализация» валюты, определяет какие факторы необходимы для того, чтобы юань стал международной валютой, уделяет основное внимание международным расчетам, которые проводятся с помощью юаня, в частности, анализирует перспективы инвестиций, выраженных в юане

Germline-restricted chromosome (GRC) is widespread among songbirds

An unusual supernumerary chromosome has been reported for two related avian species, the zebra and Bengalese finches. This large, germline-restricted chromosome (GRC) is eliminated from somatic cells and spermatids and transmitted via oocytes only. Its origin, distribution among avian lineages, and function were mostly unknown so far. Using immunolocalization of key meiotic proteins, we found that GRCs of varying size and genetic content are present in all 16 songbird species investigated and absent from germline genomes of all eight examined bird species from other avian orders. Results of fluorescent in situ hybridization of microdissected GRC probes and their sequencing indicate that GRCs show little homology between songbird species and contain a variety of repetitive elements and unique sequences with paralogs in the somatic genome. Our data suggest that the GRC evolved in the common ancestor of all songbirds and underwent significant changes in the extant descendant lineages

Synthesis and antimicrobial activity of bis-4,6-sulfonamidated 5,7-dinitrobenzofuroxans

A new series of bis-4,6-sulfonamidated 5,7-dinitrbenzofuroxans 7-11 had been synthesized and tested for antimicrobial activity. The structures of new sulfanilamide derivatives were characterized by elemental analysis, IR spectroscopy, and mass spectrometry (MALDITOF). The synthesized compounds were tested for their in vitro antimicrobial activity using the disk diffusion method against Gram-positive bacteria Staphylococcus aureus; the Gram-negative bacteria Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis; the fungal strain Aspergillus niger; and the yeast-like pathogenic fungus Candida albicans. Our results indicate that the compounds 7-11 exhibit potent antimicrobial activity. The stability of the compounds was evaluated by TG and DSC methods. © 2014 Irina V. Galkina et al