On “surface currents” of a tubular beam having helical electron trajectories in the field of a fast wave

The causes of the noncoincides of the results of the hydrodynamic and corpuscular methods of analyzing the interaction of a rotating electron beam in a fast wave, which have been presented in published papers, are investigated. Consideration of the pulsations of the beam boundaries in the hydrodynamic analysis by introducing equivalent surface currents leads to the relativistic dispersion equation derived by Gaponov [1] in the case of a small thickness of the beam walls.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 15, No. 1, pp. 136–143, January, 1972.     

An automatic reaction control chemical ionization technique in ion trap detector for quantitative plasma profding of arecoline in treated alzheimer patients

An automatic reaction control chemical ionization technique in an ion trap detector (lTD) was used to quantitate the levels of the cholinergic drug, arecoline, in plasma of treated patients with Alzheimer’s disease. The chemical ionization reaction was carried out with acetonitrile. The protonated molecules of arecoline (m I z 156) and the internal standard, homoarecoline (m / z 170), were monitored. Human plasma samples were extracted with a readily evaporable solvent mixture, the residues reconstituted and injected along with a tertiary amine-carrier into a capillary gas chromatograph interfaced with the ITD. Standard curves for plasma-extracted arecoline between 20-ng/mL and 156-pg/mL levels were linear (r> 0.9980). Satisfactory precision (relative standard deviation < 20%) and accuracy (relative error < 15%) at the limit of quantitation, 156 pg/mL arecoline, were achieved. Optimal conditions for handling of blood samples obtained by venipuncture were determined. The assay was successfully applied for the therapeutic monitoring of Alzheimer patients treated intravenously with arecoline.     

Bright spatial solitons in controlled negative phase metamaterials

A fundamental discussion of linearly polarised bright spatial soliton beams that are localised in a planar waveguide is developed in a special way that leads to the introduction of nonlinear diffraction. It is emphasised, throughout, that this kind of diffraction dominates influences from non-paraxiality and typical quintic contributions to the nonlinearity. A major discussion is given that is based upon double-negative metamaterials and makes contact with previous literature. Both homogeneous and inhomogeneous diffraction-managed, planar waveguides are investigated with a view to examining the behaviour of narrow beam production and propagation. It is also shown that a Voigt configuration of an externally applied magnetic field can be used to create significant magnetooptic control over spatial soliton propagation in asymmetric waveguides. Both this type of control and diffraction-management lie at the heart of the numerical simulations given here. In all of these cases it is shown that nonlinear diffraction has a very important influence and will create an impact upon future applications.     

The Possible Use of a Millimeter-Wave Meteoradar for Radioacoustic Sounding of the Atmosphere

The use of millimeter-wave meteoradars with amplitude modulation of radio pulses in systems of radioacoustic sounding of the atmosphere, proposed by A. L. Fabrikant, opened new opportunities in atmospheric research. However, the experimental layout and measurement technique chosen by A. L. Fabrikant are far from optimal. Even using record-power acoustic emitters, one can only perform measurements at heights not larger than 1.5-2 km. In this paper, we consider methods for optimization of the system. We propose design solutions which improve significantly (by a factor of about 10⁴) the signal-to-noise ratio in comparison with the estimates performed by A. L. Fabrikant. The influence of wind and temperature gradients on the system operation is considered. In contrast to conventional systems of radioacoustic sounding, the use of a millimeter-wave radar with a narrow radiation pattern allows one to avoid losses in efficiency due to the wind drift of the acoustic mirror. We show that the height of sounding by a system comprising a millimeter-wave radar and an acoustic emitter with standard parameters can be increased up to 10-15 km. The proposed system allows one to measure the aerosol content and the temperature and wind profiles in the atmosphere as well as to study turbulent processes during active (prestorm or thunderstorm) periods. Moreover, such a system is compact enough to be mounted on mobile platforms.     

Twisted loop groups and their affine flag varieties

We develop a theory of affine flag varieties and of their Schubert varieties for reductive groups over a Laurent power series local field k((t)) with k a perfect field. This can be viewed as a generalization of the theory of affine flag varieties for loop groups to a “twisted case”; a consequence of our results is that our construction also includes the flag varieties for Kac–Moody Lie algebras of affine type. We also give a coherence conjecture on the dimensions of the spaces of global sections of the natural ample line bundles on the partial flag varieties attached to a fixed group over k((t)) and some applications to local models of Shimura varieties.     

Jet flow around an elastic shell

In [1] an investigation was made of jet flow around an elastic plate. Below, in an exact nonlinear statement, a study is made of the problem of jet flow around an elastic cylindrical shell, fastened at one end and having the second end free. With certain limitations on the form of the shell, the single-valued solvability of the problem is demonstrated, and a method for its solution is proposed. Some results of calculations are given. A statement and a solution of the inverse problem of static hydroelasticity are also given.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 2, pp. 24–32, March–April, 1977.