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The vortex-like flow structure desired for washout of the sediment beds can be calculated using an analytical solution to the Euler formula. It is shown that using a combined vortex flow with disturbing the layer of sediment makes it possible to increase the concentration of the suspended particles, and to provide conditions for cleaning.

Noise barriers are an effective method of mitigating the noise made by various equipment. Factors influencing the acoustic efficiency of noise barriers such as height, sound-absorbing material, slanted top, and position relative to the noise source are considered. The experience of using noise barriers for cooling towers, transformers, gas-distribution plants, ventilation systems, and air inlets and casings of compressors is described.

The problem of transformation of quasimonochromatic wavetrains of surface gravity waves with narrow spatial-temporal spectra on the bottom shelf is considered in the linear approximation. By means of numerical modeling, the transmission and reflection coefficients are determined as functions of the depth ratio and wave number (frequency) of an incident wave. The approximation formulae are proposed for the coefficients of wave transformation. The characteristic features of these formulae are analyzed. It is shown that the numerical results agree quite satisfactorily with the proposed approximation formulae.

The results of theoretical and experimental studies of collective processes in helical electron beams in gyrotron-type devices are generalized. Main attention is paid to low-frequency oscillations associated with the development of instability in the space charge trapped between the cathode and the magnetic mirror. The mechanism of evolution of instability is substantiated and the effect of oscillations on the main parameters of the electron flow determining its quality is analyzed. Data on the suppression of low-frequency oscillations and resulting enhancement of the gyrotron efficiency are considered.

The specific features of the application of two-photon microscopy and spectroscopy to the investigation of multiferroic and piezoelectric nanostructures have been considered. It has been shown that the nonlinear optical response of planar multilayer barium strontium titanate/bismuth ferrite nanostructures is characterized by local electrically induced and magnetically induced contributions in specific spectral ranges. For peptide piezoelectric bio-microtubes, it has been found that the maximum value of the second harmonic generation intensity does not change along the tube, whereas the direction of polarization changes significantly.

A computer-aided digital microscope for studying microstructures at wavelengths of the second optical harmonic and two-photon luminescence is designed. In contrast to commercial instruments, the microscope is intended to study the image dependence on the angle of incidence, azimuth, and angle of the radiation receipt, as well as the polarization characteristics in organic and inorganic structures. As examples, results of studying nonlinearly optical properties of peptide tubes and microstructures based on zinc oxide are given.

A formula is proposed using which attenuation of the level of acoustic power in a heat-recovery boiler can be calculated as a function of the area of its heat-transfer heating surfaces. The silencers developed by specialists of the Moscow Power Engineering Institute for additional suppression of noise emitted from combined-cycle and gas turbine units equipped with heat-recovery boilers are considered.

The values by which noise emitted from exhaust paths of different gas-turbine units equipped with heat recovery boilers exceeds the levels prescribed by sanitary standards are calculated. Measures to reduce noise emitted from the exhaust paths of gas-turbine units with heat recovery boilers are discussed, and design solutions developed at the Moscow Power Engineering Institute for suppressing this noise are described.

Specific features of noise reduction in the exhaust part of a gas turbine unit are considered. A method is developed for calculating the optimal flow cross-sectional area of an absorption silencer installed in the path of a gas turbine unit. The effect of various factors on selection of the silencer’s optimal design is analyzed.

A theoretical analysis is made of the influence of the Raman interaction between modes on the kinetics of emission of individual modes from a traveling-wave wide-band ring laser and on the sensitivity of intracavity laser spectroscopy. Numerical modeling shows that the Raman mode interaction gives rise to random intensity fluctuations in various laser modes, but does not limit the sensitivity. At the onset of lasing the Raman mode interaction results in the establishment of specific relationships between the amplitudes and phases of the various modes. The Raman mode interaction then decays rapidly, increasing the average time of the fluctuations and enhancing the intracavity laser spectroscopy sensitivity proportionally to the lasing duration.

An analysis is made of the influence of amplitude beats of laser modes on the dynamics of operation of a wide-band laser. It is shown that an allowance for these beats in a transversely inhomogeneous intracavity medium is equivalent to an allowance for its lens-like properties. The lens-like nature of the active medium shifts the lasing band. An inhomogeneity of the absorbing medium can result in a major redistribution of the intensity of lasing in the vicinity of absorption lines. It is shown that the gain of laser modes changes negligibly due to an inhomogeneous saturation of an absorbing medium.

The technique of penetrating deep sclerectomy with suprachoroidal explanto-drainage as well as the results of postoperative follow-up, exceeding 2 years, and of the early-described sinustrabeculectomy with regulated filtration are presented in the article. Operations were made on 59 eyes (58 patients aged 13 to 70) with the below forms of secondary glaucomas: new-vascular, postuveal, dystrophic (at retinal detachment), posttraumatic (contusion-type), phakotopic, postoperative (aphakic), and hemolytic. The below goals were set while elaborating the methods: the possibility to regulate postoperatively the intraocular pressure, elimination of the pain syndrome, the organ-preserving effect, stabilization of the clinical cause and shaping-up of reliable drainage paths. The authors registered a positive effect in 87.5% of cases.

Two courses of immunoadsorption with 'Ig Adsopak' were used in the treatment of a patient with dilated cardiomyopathy (DCM) during which all class G and partially class M and A immunoglobulins were removed. Every course consisted of 5 daily procedures and resulted in removal of 98% of immunoglobulins. This was associated with complete removal of autoantibodies to beta1-adrenoreceptor. After the end of a course loss of immunoglobulins was replenished by intravenous infusion of Pentaglobin and Oktagam. Echocardiographic study carried out before, during and after second course of apheresis revealed reduction of left and right ventricular and atrial volumes and dimensions, improvement of contractility of anterior part of interventricular septum and of anterolateral left ventricular wall. As efficacy of drug therapy of dilated cardiomyopathy is low and facilities of cardiac transplantation are limited the method of therapeutic apheresis reveals novel perspectives of the treatment of dilated cardiomyopathies.

A new method for surgical treatment of secondary glaucoma (neovascular, postuveal, traumatic, and aphakic) is described. The aims of the new method are as follows: regulation of ophthalmic tone in the postoperative period, pain relief, organ preservation, stabilization of the process, and creation of reliable routes of intraocular fluid discharge with formation of a stable diffuse functional pad. Seven patients (8 eyes) aged 13-70 years were operated on and followed up for up to 6 months. Preliminary results are presented. Positive shifts were observed in all cases.

The efficacy of drug (inderal, corinfar) treatment in combination with manual therapy (the course was 4-7 sessions) was examined in hypertensives with cervical osteochondrosis. The latter was evidenced by X-ray studies. Clinically, cervical osteochondrosis appeared as vertebrobasilar insufficiency. The vertebral artery bed displayed circulatory disorders documented by rheoencephalography, electroencephalography, ultrasound Doppler echography of the head and neck vessels. Treating the patients with drugs in combination with manual therapy resulted in improved circulation in the vertebral artery bed, lower clinical signs of vertebrobasilar insufficiency. There was a more persistent and more pronounced decrease in blood pressure with small-dose antihypertensive agents.

The rate equation model is used to investigate the stimulated emission kinetics of broad-band multimode lasers in the presence of an additional gain a in various modes and over a wide time interval, taking into account the spontaneous radiation. Condensation of the spectrum exhibiting features of a phase transition is observed for an additional gain higher than a certain critical value. The quantitative characteristics of the effect are obtained. An analysis is made of the mechanism of appearance of an additional gain due to the lens-like properties of an intracavity gas-discharge cell. Estimates of a are given for various resonator configurations and a comparison is made with experiments.

The History Institute, USSR Academy of Sciences, has recently published the materials of the April 1961 meeting of its academic council on the problem of the history of the building of socialism and communism in the USSR. (1)

A theoretical analysis is made of the narrowing ("condensation") of the emission spectrum of a wide-band laser with a weak but narrow gain profile. The condensation represents a phase transition similar to that on appearance of lasing and is essentially "second" lasing. The mechanism of condensation of the spectrum near a strong absorption line is considered.

A total of 52 subjects (27 normal persons not abusing tobacco-smoking and 25 tobacco-smokers without respiratory disorders) were examined for external respiration function. A study was also made of the capnography data. It has been demonstrated that the classical criteria of the functional disorders of ventilation (FVC, RFV1, RFV1/FVC, MPV) do not enable one to make an early diagnosis of the ventilatory alterations in subjects with a risk of the development of CNPD (in tobacco-smokers). Analysis of the last third of the forced expiration curve flow-volume appeared to be of great informative value. There was a marked correlation between the capnogram characteristics and external respiration function characterizing patency of the small bronchi. It is concluded that capnography can be used as a method for assessing bronchial patency. The most informative criteria of the capnogram are provided.

Computed spirography, He/O test and capnography evaluation of external respiration has been carried out for 52 subjects. Of these 27 were nonsmokers, 25 smoked but had no history of respiratory diseases. The integral criteria of external respiration obstruction (MOCmax, MOC50, MOC75) proved inadequate diagnostic tool for early detection of ventilatory alterations in smokers who are at risk to develop chronic nonspecific pulmonary diseases. Pharmacological tests, He/O investigation and capnography did reveal defects in small bronchi permeability in all the smokers. Problems of pathogenesis of obstructive affections of distal regions of the bronchial tree are under consideration.

Thirty-three patients with infectious allergic bronchial asthma and chronic obstructive bronchitis and 47 normal subjects were examined with the aid of a complex of bloodless research methods for the pulmonary circulation and central hemodynamics under graded physical exercise of minor power. Investigation at rest did not disclose any hemodynamic disorders in the greater and pulmonary circulation. Application of bicycle ergometry to patients with chronic obstructive bronchitis and bronchial asthma in a stage of remission made it possible to reveal latent hemodynamic disorders of the pulmonary circulation that manifested by long-term elevation of the pressure in the pulmonary artery and pulmonary vascular resistance, restitution of the central hemodynamics according to the hyperkinetic type. The use of the generally accepted formulas for calculating the proper magnitudes of the ejection period and mechanical systole with the heart rate exceeding 90 per minute resulted in overdiagnosis of the overload of the right ventricle. The authors offer the regression equations for calculating these parameters during tachycardia.

Problems of early diagnosis, prophylaxis and therapy of chronic cor pulmonale (CCP) were discussed. It was pointed out that the right ventricular hypertrophy could not be regarded as the main diagnostic sign of CCP as it was recognized at late stages of diseases when therapy was of low efficacy. The authors proposed to specify CCP clinico-functional definition with 4 functional classes with relation to the expression of disturbances of ventilation function of the lungs and hemodynamics. The results of isoket and corinfar therapy of 250 patients with obstructive bronchitis of various gravity of ventilation and hemodynamic disturbances were presented. They showed that the use of prolonged nitrates was found appropriate in the patients of the 3rd-4th functional classes with signs of developed CCP. The use of prolonged nitrates in the patients of the 1st-2nd functional classes resulted in an increase of pulmonary functional shunting of the blood. Calcium antagonists made a balanced effect on the bronchial permeability and pulmonary hemodynamics. Their use was indicated at early stages of the process when functional mechanisms played the leading role in the pathogenesis of disturbances.

Rate equations are used to show that the combination of fluctuations and inhomogeneities can have a significant influence on the dynamics of emission of multimode wide-band lasers even when the lasing duration is ~ 1 ms. The sensitivity of intracavity spectroscopy is then limited to ~ 10 − 8 cm − 1.