Magnetic flux locking in two weakly coupled superconducting rings

We have analyzed the quantum interference effects in the macroscopic ''superconducting molecule''. The composite system consists of two massive superconducting rings, each interrupted by a Josephson junction, which are at the same time weakly coupled with one another. The special case of coupling via the Josephson four-terminal junction is considered. The structure of the macroscopic quantum states in an applied magnetic field is calculated. It is shown, that depending on the values of the magnetic fluxes through each ring, the system displays two groups of states, the ''orthostates'' with both induced currents going in the same direction, and the ''parastates'' with the opposite currents and with the total induced flux locked to zero value. The transition to the flux locked state with changing of the total applied flux is sudden and is preserved in a certain interval which is determined by the difference of the fluxes applied through each ring. It makes the system sensitive to small gradients of the external magnetic field.Comment: 8 pages in Latex, 3 figures (eps

Coherent current states in mesoscopic four-terminal Josephson junction

A theory is offered for the ballistic 4-terminal Josephson junction. The studied system consists of a mesoscopic two-dimensional normal rectangular layer which is attached in each side to the bulk superconducting banks (terminals). The relation between the currents through the different terminals, which is valid for arbitrary temperatures and junction sizes, is obtained. The nonlocal coupling of the supercurrents leads to a new effect, specific for the mesoscopic weak link between two superconducting rings; an applied magnetic flux through one of the rings produces a magnetic flux in the other ring even in the absence of an external flux through the other one. The phase dependent distributions of the local density of Andreev states, of the supercurrents and of the induced order parameter are obtained. The "interference pattern" for the anomalous average inside the two dimensional region can be regulated by the applied magnetic fluxes or the transport currents. For some values of the phase differences between the terminals, the current vortex state and the two dimensional phase slip center are appeared.Comment: 17 pages in Latex and 6 ps Figures. Will be published in Low Temp.Phy

Semiclassical quantization of non-Hamiltonian dynamical systems without memory

We propose a new method of quantization of a wide class of dynamical systems that originates directly from the equations of motion. The method is based on the correspondence between the classical and the quantum Poisson brackets, postulated by Dirac. This correspondence applied to open (non-Hamiltonian) systems allows one to point out the way of transition from the quantum description based on the Lindblad equation to the dynamical description of their classical analogs by the equations of motion and vice versa. As the examples of using of the method we describe the procedure of the quantization of three widely considered dynamical systems: 1) the harmonic oscillator with friction, 2) the oscillator with a nonlinear damping that simulates the process of the emergence of the limit cycle, and 3) the system of two periodic rotators with a weak interaction that synchronizes their oscillations. We discuss a possible application of the method for a description of quantum fluctuations in Josephson junctions with a strong damping and for the quantization of open magnetic systems with a dissipation and a pumping.Comment: 8 pages, 0 figure

ISLES: Probing Extra Dimensions Using a Superconducting Accelerometer

In string theories, extra dimensions must be compactified. The possibility that gravity can have large radii of compactification leads to a violation of the inverse square law at submillimeter distances. The objective of ISLES is to perform a null test of Newton s law in space with a resolution of one part in 10(exp 5) or better at 100 microns. The experiment will be cooled to less than or equal to 2 K, which permits superconducting magnetic levitation of the test masses. To minimize Newtonian errors, ISLES employs a near null source, a circular disk of large diameter-to-thickness ratio. Two test masses, also disk-shaped, are suspended on the two sides of the source mass at a nominal distance of 100 microns. The signal is detected by a superconducting differential accelerometer. A ground test apparatus is under construction

Prevalence of sarcopenia in the French senior population

Introduction A muscle mass normalized for height2 (MMI) or for body weight (SMI) below 2SD under the mean for a young population defines sarcopenia. This study aimed at setting the cutoffs and the prevalence of sarcopenia in the French elderly population. Another objective was to compare the results obtained with SMI and MMI.Methods: Muscle mass was assessed by bioelectrical impedance analysis in 782 healthy adults (<40 years) to determine skeletal mass index (SMI, muscle mass*100/weight) and muscle mass index (MMI, muscle mass/height2). Prevalence was estimated in 888 middle aged (40–59 years) and 218 seniors (60–78 years). All were healthy people.Results: For women mean-2SD were 6.2 kg/m2 (MMI) and 26.6% (SMI); for men limits were 8.6 kg/m2 (MMI) and 34.4% (SMI). In middle aged persons a small number of them were identified as sarcopenic. In healthy seniors, 2.8% of women and 3.6% of men were sarcopenic (MMI). The prevalence was 23.6% in women and 12.5% in men with SMI. MMI and SMI identified different sarcopenic populations, leaner subjects for MMI while fatter subjects for SMI.Conclusion: Cutoff values for the French population were defined. Prevalence of sarcopenia was different from that in the US population

ВИЗНАЧЕННЯ КОЕФІЦІЄНТА БЕЗПЕЧНОЇ РОБОТИ ДЛЯ РІЗНОГО ТИПУ ЗАХИСНОГО ОДЯГУ ПОЖЕЖНИКІВ

The paper presents statistics on injuries and deaths of firefighters on duty. A mathematical model for determining the heat transfer rate on the different types of model fires is developed. Various cases of changes in heat transfer rate under the influence of air currents are regarded. Safe operation coefficient is calculated. It can be used during creating and introducing individual devices for informing firefighters about reaching the critical parameters of the heat transfer rate.В роботі представлені статистичні дані з травматизму та загибелі пожежників під час виконання службових обов'язків. Розроблена математична модель для визначення теплового потоку на пожежі при горінні макетних вогнищ. Розглянуті різні випадки зміни теплових потоків, під впливом нахилу факела. На цій основі виведено коефіцієнт безпечної роботи, який надалі може використовуватись, при конструюванні індивідуальних приладів оповіщення про досягнення критичних параметрів теплових потоків для захисного одягу того чи іншого тип

Використання невзаємних пасивних пристроїв в КВЧ-терапії

Сonsidered the basic scheme of construction equipment for EHF-therapy. There are an investigation of the influence of the inconsistency of antenna on the level of absorption power by the patient. Shown that the use of passive nonreciprocal devices reduces the dependence of the absorption of therapeutic doses antenna's inconsistency.Рассмотрены основные схемы построения аппаратуры для КВЧ-терапии. Исследовано влияние несогласованности антенны на уровень поглощения мощности пациентом. Показано, что применение невзаимных пассивных устройств значительно уменьшает зависимость терапевтической дозы поглощения от несогласованности антенны.Розглянуті основні схеми побудови  апаратури для КВЧ-терапії. Досліджено вплив неузгодженості антени на рівень поглинання потужності пацієнтом. Показано, що застосування невзаємних пасивних пристроїв значно зменшує залежність терапевтичної дози поглинання від неузгодженості антени

Splitting of Landau levels of a 2D electron due to electron-phonon interactions

We show that in a very strong magnetic field $B$ electron-phonon interaction gives rise to a splitting of Landau levels of a 2D electron into a series of infinitely degenerate sublevels. We provide both qualitative and quantitative description of this phenomenon. The cases of interaction with acoustic and polar optical phonons are considered. The energy distance between nearest sublevels in both cases tends to zero as $B^{-1/2}$ at large $B$.Comment: 4 pages, LaTe

Are the Same Clinical Risk Factors Relevant for Incident Diabetes Defined by Treatment, Fasting Plasma Glucose, and HbA1c?

International audienceOBJECTIVE: To compare incidences and risk factors for diabetes using seven definitions, with combinations of pharmacological treatment, fasting plasma glucose (FPG) ≥7.0 mmol/L, and HbA(1c) ≥6.5%. RESEARCH DESIGN AND METHODS: Participants aged 30-65 years from the Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) cohort were followed for 9 years. RESULTS: More men had incident diabetes as defined by FPG ≥7.0 mmol/L and/or treatment than by HbA(1c) ≥6.5% and/or treatment: 7.5% (140/1,867) and 5.3% (99/1,874), respectively (P < 0.009); for women incidences were similar: 3.2% (63/1,958) and 3.4% (66/1,954). Known risk factors predicted diabetes for almost all definitions. Among those with incident diabetes by FPG alone versus HbA(1c) alone, there were more men (78 vs. 35%), case patients were 8 years younger, and fewer were alcohol abstainers (12 vs. 35%) (all P < 0.005). A diabetes risk score discriminated well between those with and without incident diabetes for all definitions. CONCLUSIONS: In men, FPG definitions yielded more incident cases of diabetes than HbA(1c) definitions, in contrast with women. An FPG-derived risk score remained relevant for HbA(1c)-defined diabetes