Geotechnology of restoration of culverts in complex ground conditions without their decommissioning

In the article, on the basis of extensive theoretical and experimental research carried out, innovative geotechnology for repair of culverts is presented, which provides an improvement in the conditions for interaction between the body of the structure and the soil massif with increasing technogenic impacts. The analysis of the technical condition of the culvert transport and engineering structures under special operating conditions is given. Factors determining their premature emergency condition and interfering with stable functioning under increasing loads and impacts have been studied. On the basis of many years of experimental and theoretical and experimental design work, geotechnology «Saturn» has been proposed, suitable for repairing all types of culverts on railroads and highways, engineering infrastructure facilities, and especially for repair and reconstruction of pipes under conditions of a constant intensive watercourse with nonstandard (atypical) constructive solutions, as well as located in hard-to-reach and difficult for the organization of the construction site sections of the route. The experience of successful application of the developed technology "Saturn" on the railroad during the repair and reconstruction of long-maintained culverts of stone and concrete pipes under the conditions of a constant intensive watercourse and at water disposal facilities during repair of deep tunnels without their decommissioning is described

Thermodynamic cycle with two-component working fluid

The article deals with the implementation of the thermodynamic cycle using the two-component working fluid. An estimated calculation of the efficiency of using the two-component working fluid, and a variant implementation of the thermodynamic cycle rotary vane engine with an external heat supply are described

DETERMINATION OF CHAMBER AND PISTON GEOMETRY FOR A ROTARY TYPE EXPANSION MACHINE

The article deals with the determination of chamber and piston geometry for a rotary expansion machine. Analytical expressions for the working surface area of piston and for chamber volume are derived. Three defining parameters of the expansion machine were obtained: gas dynamic machine constant Cp; constant M0 connecting torque and Cp; the main dimensionless parameter of the machine Q0, which relates the volume of the chamber and the torque

SYNTHESIS OF A LEVER-CAM MOTION TRANSDUCER FOR A ROTARY VANE PUMP

The article solves problem of synthesizing a lever-cam motion transducer that converts rotary motion of input shaft of a rotary pump into motion of its vanes required for volumetric pumping of gases and liquids. Analytical expressions for theoretical profile of cam of lever-cam transducer of the movement of rotary vane pump are obtained. The cam profile was built according to analytical expressions.

GAS DYNAMICS OF WORKING FLUID INLET INTO CHAMBER OF ROTARY EXPANSION MACHINE

In this article, a mathematical model of working fluid inlet into chamber of rotary expansion machine from source of superheated steam. The main practical problem that can be solved on the basis of this model is to determine dependence of torque on the angular velocity, i.e. in the construction of mechanical characteristics of rotary expansion machine.

CONSTRUCTION OF PISTON OUTER PROFILE FOR ROTARY TYPE EXPANSION MACHINE

The article discusses methods for constructing piston outer profile for the rotary type expansion machine in order to reduce unwanted (parasitic) volumes and offers options for constructing outer profile of piston using analytical and geometric methods

OPTIMIZATION OF MECHANICAL STRENGTH OF ROTARY-VANE ENGINE

The article discusses a rotory-vane heat engine with a lever-cam mechanism motion conversion (an engine may be an internal combustion or external combustion). The output shaft of the engine adds drive torque from the working fluid pressure forces acting on the blade and the inertial moment of the forces of inertia of engine components. The mechanical strength of the motor is dependent on the magnitude and phase of these two torque. The purpose of the article is to determine the conditions under which mechanical strength is minimized

Induced Modulation of a Chirped Laser Pulse at Terahertz Frequency with Spectral Phase Shaping

The possibility of using harmonic modulation of the spectral phase to generate multiple replicas of the original short laser pulse or controlled periodic intensity modulation at the terahertz frequency of the stretched chirped laser pulse is shown theoretically and experimentally

Up-regulation of the embryonic self-renewal network through reversible polyploidy in irradiated p53-mutant tumour cells

We have previously documented that transient polyploidy is a potential cell survival strategy underlying the clonogenic re-growth of tumour cells after genotoxic treatment. In an attempt to better define this mechanism, we recently documented the key role of meiotic genes in regulating the DNA repair and return of the endopolyploid tumour cells (ETC) to diploidy through reduction divisions after irradiation. Here, we studied the role of the pluripotency and self-renewal stem cell genes NANOG, OCT4 and SOX2 in this polyploidy-dependent survival mechanism. In irradiation-resistant p53-mutated lymphoma cell-lines (Namalwa and WI-L2-NS) but not sensitive p53 wild-type counterparts (TK6), low background expression of OCT4 and NANOG was up-regulated by ionising radiation with protein accumulation evident in ETC as detected by OCT4/DNA flow cytometry and immunofluorescence (IF). IF analysis also showed that the ETC generate PML bodies that appear to concentrate OCT4, NANOG and SOX2 proteins, which extend into complex nuclear networks. These polyploid tumour cells resist apoptosis, overcome cellular senescence and undergo bi- and multi-polar divisions transmitting the up-regulated OCT4, NANOG and SOX2 self-renewal cassette to their descendents. Altogether, our observations indicate that irradiation-induced ETC up-regulate key components of germ-line cells, which potentially facilitate survival and propagation of the tumour cell population