Correlation dependencies between the dynamic viscosity of slag and its structural parameters were studied to determine an optimal basicity of silicon smelting slag under the addition of boron oxide to eliminate slagging of the bottom of ore-smelting furnaces. Experimental studies were conducted on CaO–SiO2 and CaO– SiO2–B2O3 model slags obtained at 1600°С. Raman spectroscopic analysis was carried out using a Horiba JobinYvon HR800UV analyzer (France). Theoretical calculations of slag viscosity were performed using Urbain and Mills models. During the experiments, the key structural parameters of slag systems varied within the following limits: the experimental Raman spectrum deconvolution function from 1.41 to 2.45 and optical basicity from 0.58 to 0.68. The obtained experimental and theoretical data were related by mathematical dependencies. It was found that the dynamic viscosity of slag can be promptly determined by Raman spectroscopy on the basis of mathematical models. The dependence obtained shows that slag viscosity decreases upon an increase in the number of bridging oxygen atoms in the silicate anion structure. Notably, this decrease in slag viscosity is observed up to the value of the experimental Raman spectrum deconvolution function of ~1.55-1.60 or slag optical basicity of 0.60–0.62. When B2O3 is added, the viscosity undergoes a further decrease. In practice, for CaO–SiO2 slag systems, the use of boroncontaining flux as a liquefying agent is reasonable at CaO/SiO2 = 0.61–0.63 while maintaining the content of B2O3 in the slag at a level of 1%. The two models (classical and modified) proposed by Urbain were established to be more suitable for theoretical calculation of viscosity in CaO–SiO2 and CaO–SiO2–B2O3 systems. Mills’ model is not suitable for these purposes, since the correlation coefficients in the corresponding mathematical model are not sufficiently large. Further research in this direction is required in order to establish appropriate dependencies of slag viscosity on its structural parameters at different temperatures.

The occurrence of tracheal fistulas of ischemic genesis combined with the failure of esophagogastroanastomosis and the communication between them is a rare and formidable complication after esophagectomy with mediastinal lymphadenectomy due to its anatomical position and extensiveness. However, it is insufficiently documented in the literature, both in terms of treatment and in terms of its causes. This observation aims to demonstrate the rare cause of this complication and the atypical successful treatment. In this case, a patient with squamous cell carcinoma G2 of the middle third of the esophagus and TNM stage cT3NxM0. On the McKeown thoracoscopic-laparotomy esophagectomy intraoperatively a short arterial vessel with a diameter of about 3 mm, which passed through the paracancerous infiltration and supplied blood to the esophagus and trachea revealed. The vessel was not isolated from the infiltrate, but was clipped and crossed between the aorta and infiltrate to maintain surgery ablastic. On the 7th day after the operation the insolvency of esophagogastroanastomosis, the fistula of the trachea with mediastinum and the communication between the leak of esophagogastroanastomosis and the fistula of the trachea were diagnosed. We consider this combination as a special case of esophagogastroanastomosis fistula, complicated by the communication between the right pleural cavity and pneumothorax. According to our experience, partial leak of esophagogastroanastomosis successfully heals by secondary tension within 10–15 days against the background of cervicotomic wound drainage and feeding through a nasointestinal tube. In this case there was a leak of saliva in the mediastinum and its penetration into the lumen of the trachea and the right pleural cavity. Surgical diversion of the fistula and stenting of the trachea were considered, but not applied, as the fistula in our opinion was controlled, but the aggressive content of the gastric conduit prevented healing. The patient was on assisted lung ventilation with minimal pressure support and inflow increased oxygen fractio. For this reason, we considered the best stenting of the esophagogastroanastomosis leak area to be covered with a stent in order to stop the aggressive content of the gastric stem from entering the fistula, which led to the successful treatment of the developed severe complication. It should be noted that this method of treatment may be ineffective in patients who need pressure support during ventilation.

The interaction of a 1053 nm picosecond laser pulse with a solid target for focused intensities of up to 10(19) W/cm(2) are studied by measurements of the absorption of the laser light in the plasma and by measurements of the production of hard X-rays. Absorption measurements are made by collecting the scattered light in set of calorimeters. Light scattered in backward and specular directions is collected separately. Measurements are presented for both high and low Z targets. Hard X-ray spectrum in range 15 - 1000 keV and hot electron production in range 1 - 22 MeV are measured using a multichannel filter/scintillator and filter/semiconductor spectrometers. Spatial parameters of fast ions are studied.

A mathematical model is considered describing absorption of hydrogen by a cylindrical specimen in a closed volume under boundary conditions of mode I. The kinetics of hydrogen absorption by commercial titanium was studied experimentally in the: temperature range 600-950 degrees C. Comparison of experimental and calculated data made if possible to determine hydrogen diffusion coefficients and the range of applicability of the proposed model.

The effect of hydrogen on the phase composition of the VT25U-grade high-temperature titanium ahoy or temperatures from 20 to 1000 degrees C was studied. The alloying with hydrogen up to concentrations exceeding 0.4% lends to the formation of ordered alpha(2) phase in the alloy. Temperatures and compositions corresponding to predetermined ratio between the volume fractions of beta and alpha phases are established. The hydrogen addition leads to the depletion of beta phase in beta-stabilizing elements (molybdenum and tungsten) at the temperatures of (alpha + beta) field and to the enrichment of alpha phase with aluminum. The volume effects of (alpha --> beta) transformation are calculated for various hydrogen contents in the alloy. Maximum volume misfit between alpha and beta phases corresponds to the temperature of (alpha + beta/beta) transformation and to maximum hydrogen content.

X-Ray diffraction phase analysis and transmission electron microscopy were used to study the crystal structure and the conditions leading to the formation of the X-phase discovered earlier in Ti-Nb alloys (up to 33 at.% Nb) alloyed with hydrogen (up to 25 at.%). It was found that the X-phase is a hydride intermediate between TiH2 and NbH with a bct lattice (c/a > l). It is formed following a eutectoid mechanism from beta-phase oversaturated with hydrogen in alloys with Nb content from 5 to 22 at.% and H content over 5 at.%. The degree of tetragonality of hydride lattice is determined by the niobium content of the alloy.

The introduction of up to 0.1 wt % of hydrogen into the VT6 alloy with previously obtained ultra fine-grained structure does not cause substantial changes in superplastic characteristics but leads to small increase in elongation.

A thermodynamical model of hydrogen solution in Ti3Al was proposed. The free energy and the long-range order were calculated as a function of the composition and temperature. Hydrogen enhances the the long-range order degree caused by the formation of the alpha(2)-phase by nucleation and growth mechanism. The temperature of the equilibrium between ordered and the disordered phases increases with hydrogen concentration, and the range in which the formation of the alpha(2)-phase occurs by the nucleation and growth mechanism (I-order) broadens. The above effects facilitate the control of the structure of the Ti3Al-based alloys by reversible hydrogen alloying.

The phase composition and crystal structure of the Ti-Nb alloys, with Nb contents up to 33 at% and additional alloying with hydrogen up to 24 at% were studied using X-ray diffraction analysis (XDA) and transmission electron microscopy (TEM). The alloys were formed after quenching from beta-phase temperatures. phase diap;ram are constructed for the Ti-Nb-H quenched alloys. Now details of structure formation were detected in addition to those studied earlier for titanium alloys with beta-stabilizers. In particular the possibility of hydrogen atom ordering is shown in the interstitial sites of the rhombic alpha "-martensite lattice. It marked the heterogenic conceptions of the omega phase. The morphology of the omega phase has the form of a raft which is not typical for titanium alloys.

The scientific principles of thermal hydrogen treatment of titanium alloys have been presented. The basic technological processes have been described based on controlling the phase formation in hydrogen alloyed materials. Thermal hydrogen treatment has been shown to affect the structure and mechanical properties of as-cast and strained semi-products and weld joints of different titanium alloys. The most promising application fields of the hydrogen technology of titanium alloys have been considered.

Some aspects of interaction between hydrogen and metallic materials have been considered. Hydrogen may be not only a detrimental impurity that embrittles the material, but also a valuable alloying addition. In alloys that exothermally absorb hydrogen, e.g., Ti-base alloys, hydrogen can be used, depending on particular requirements, either as a temporary alloying element enhancing the workability of structural materials oh as an active element for commercial hydrogen-bearing materials. We have reviewed general aspects and physicochemical fundamentals of the theory of hydrogen treatment based on reversible hydrogen alloying, and the new hydrogen-bearing materials technology based on additional hydrogen alloying of solid metal matrix.

Phase transformations occurring in VT18U heat-resistant titanium alloy containing to 1 wt.% H have been studied during vacuum annealing. Variations of lattice parameter and phase volume fractions during hydrogen desorption have been analyzed. At an initial hydrogen concentration of higher than 0.4 wt.% and a vacuum annealing temperature of max. 650-700 degrees C, a heterophase structure is formed, containing alpha-phase precipitates whose chemical composition considerably varies (by 4-6 wt.% Al). We have plotted diagrams showing alloy composition variation during hydrogen desorption for various initial hydrogen concentrations and annealing temperatures.

Experimental results have been reported dealing with the effect of hydrogen on the critical cooling rates of various titanium alloys and the diffusion mobility of aluminum and vanadium in the beta-phase of titanium. Hydrogen alloying of laboratory and commercial multicomponent Ti-base alloys reduces their critical cooling rates and hinders in the attainment of phase equilibrium on heat treatment. Aluminum and vanadium concentration profiles in a weld joint of VT6 and VT1-0 alloys have been measured, and the diffusion coefficients of the elements in the beta-phase have been calculated An increase in hydrogen concentration from 0.02 to 1.2 wt.% reduces the vanadium and aluminum diffusion coefficients in the beta-phase by 4 and 3 times, respectively, with the decrease being the greatest for hydrogen concentration less then 0.3 wt.%.

Effect of hydrogen as a constant alloying element on the mechanism and kinetics of the beta reversible arrow alpha " martensitic transformation (MT) is Studied in titanium-based alloys of hypocritical composition. Crystallographic and kinetic parameters of MT as well as the special features of the microstructure and substructure of the alpha " martensite in the hydrogen-bearing alloys art determined. The diagrams permitting the phase composition of the alloys after quenching from beta and alpha + beta fields and after cooling from beta field at different Fates to he predicted were constructed using an alloy VT23 as an example.

Phase equilibria in thermodynamically closed hydrogen-bearing multicomponent titanium-based systems are considered. Basic regularities of the change in phase composition and structure are outlined and the temperature-concentration diagrams of the phase composition of multicomponent titanium alloys of various grades additionally alloyed with hydrogen art constructed. In all alloys, hydrogen contained in solid solution decreases the temperature of (alpha + beta/beta) equilibrium and, depending upon the content of the main beta-stabilizing elements and aluminum, may lead to a complete or partial eutectoid transformation with precipitation of hydrides as well as to the development of the alpha-solid-solution ordering and to the formation of Ti3Al-based alpha(2) phase. The alloying with hydrogen leads to the increase in the volume portion of beta phase and to the increase in concentration of the main beta-stabilizing components in this phase, as well as to the enrichment of the alpha phase with aluminum The hydrogen content and temperature dependences of the volume misfit between the phases in equilibrium with each other are established.

Beams of ions with energy up to 10 MeV/A and average current up to 2 mA are required in some cases (proton accelerators as neutron sources, high-energy ion implanters, and accelerators for charged-particle activation analysis). Accelerators with alternating-phase focusing (APF) are suitable for these purposes. These accelerators have been developed and put into operation at the Moscow Physical Engineering Institute in 1987-8 (URAGAN-1 and URAGAN-2). They are designated for research work in material science and ion implantation. The work carried out shows that, at pulse currents of accelerated beams up to 10 mA in the low duty factor mode of operation, resonant linacs with alternating-phase focusing are quite competitive with RFQ (radio frequency quadrupole) ones while surpassing the latter in mass-size features.<>