Parameters Of Chambers Research Articles

P1572 The role of 3D echocardiography in the evaluation of left ventricular remodeling

Abstract Purpose to assess the left ventricular (LV) remodeling with using transthoracic 3D Echo and MRI in young athletes. Materials for the period from October 2015 to April 2018, 88 athletes (61 men and 27 women) were examined. Mean age was 20.8 ± 3.9 years. Group A (professionals) – 65 athletes (4 or more training days a week, experience in sports for at least 7 years, the presence of at least the 1st sports category). Group B (Amateurs) – 23 athletes (3 or less training days a week). By types of loads were identified 4 groups: 1st - high-static, low-dynamic (climbing); 2nd - medium-static, medium-dynamic (volleyball, Rugby, sports dancing); 3rd - medium-static, high-dynamic (badminton, orienteering, hockey); 4th - high-static, high-dynamic (triathlon, water polo, rowing). Methods 2D-, 3D-Echo was performed on Vivid E9 XDclear 4D (GE, USA). With the help of software package for processing 3D arrays (4D auto LVQ and 4D Strain and LV-mass) in automatic and semi-automatic mode was obtained end diastolic and end systolic volumes (EDV, ESV), ejection fraction (EF) and LV mass. The device was used for MRI - Avanto (Siemens) - 1.5 T, using: sensors for breathing and synchronization with ECG, standard surface coil Body Matrix. Visualization of the mobile myocardium was carried out by SSFP protocols in standard two-and four-chamber view, as well as on the short axis. In addition, the black-blood Protocol was performed in axial projection for visualization of mediastinal organs and chest. Evaluation of the results was performed on a workstation Syngo Via VB10B (Siemens) using a worker thread MR Cardiac analisis. Results There were significant differences in the types of loads (p < 0.001): 22% of men in Group B had 1st type, 2nd type - 78% of men and 93% of women in group B, 3rd type - 45% of men and 36% of women in group A, 4th type - 39% of men and 21% of women in group A. In the evaluation of LV remodeling and its relationship with the type of loads revealed significant differences (p < 0.01): 87.5% had LV remodeling (95.4% - aggregate type load 1, 2, 3), 6.8% - concentric remodeling (21.7% of all type 4), and 4.5% eccentric hypertrophy (8.7% of all type 4), 1.1 per cent of concentric hypertrophy (4.4% of all type 4). Consequently, most athletes with loads of type 4 had different types of LV remodeling. Comparing 3D Echo and MRI, high-grade positive correlations were obtained in indicators: EDV (R 0.82, p < 0.0001), ESV (R 0.80, p < 0.0001), LV mass (R 0.85, p < 0.0001), as well as moderate positive the index of EDV (R 0.54, p < 0.037) and unreliable for the EF. Conclusions three-dimensional visualization allows to carry out a reliable assessment of the volumetric parameters of the heart chambers, comparable with MRI data and to identify the signs and type of LV remodeling. Requires further study of the performance of 3D Echo in athletes, given the lack of normative data on the modern stage.

ГЕОМЕХАНИЧЕСКОЕ ОБОСНОВАНИЕ ПАРАМЕТРОВ УСТОЙЧИВЫХ КАМЕР И ЦЕЛИКОВ В СЛОЖНЫХ ГОРНО-ГЕОЛОГИЧЕСКИХ УСЛОВИЯХ

Актуальность исследования обусловлена необходимостью обеспечения безопасности на Соколовском подземном руднике, а также повышения полноты и качества выемки руды в сложных горно-геологических условиях – при наличии покрывающей толщи обводненных рыхлых отложений. Цель: определить оптимальные параметры устойчивых камер и целиков для предотвращения обрушения горных пород и проникновения песчано-глинистых масс в подземные выработки. Объект: массив горных пород на Северном участке Соколовского месторождения. Методы. Многовариантное численное моделирование методом конечных элементов в двумерной постановке выполнялось в программе Rocscience RS2, что позволило учесть большое количество факторов, влияющих на состояние массива. При расчетах приняты во внимание не только физико-механические свойства пород и действующие в массиве напряжения, но и структурные характеристики массива, а также степень техногенного воздействия. В качестве модели поведения массива использовалась модель Хоека–Брауна, отличительным преимуществом которой является ее нелинейность. Так как реальный массив характеризуется неоднородностью прочностных свойств и напряженно-деформированного состояния, был выполнен предусмотренный в программном комплексе Rocscience вероятностный анализ, учитывающий изменение граничных условий в установленных интервалах для создаваемой модели. В результате численного моделирования определено изменение напряженно-деформированного состояния массива, на основании чего вычислены коэффициент устойчивости окружающего массива, величины и направления его смещений, а также установлены зоны распределения вероятности разрушения массива в заданных интервалах граничных условий. Определены параметры камер и целиков, обеспечивающие общую устойчивость, минимизирующие возможность прорыва водогрязевых масс в выработки. Выводы. Сохранение устойчивости кровли подземных камер при отработке очистных рудных блоков на шахте «Соколовская» позволит снизить риск проникновения песчано-глинистых масс в подземные выработки, обеспечивая безопасное и эффективное ведение горных работ, а также повысить полноту и качество выемки руды. Выполненное методом конечных элементов многовариантное численное моделирование влияния очистных выработок на массив позволило определить оптимальные геометрические параметры камер и целиков, обеспечивающие устойчивость окружающего массива. Применение программного комплекса Rocscience RS2 в результате учета большого количества факторов, влияющих на состояние массива, значительно повышает надежность оценки устойчивости массива.

THERMAL BEHAVIOR OF FOREST BIOMASS WASTES PRODUCED DURING COMBUSTION IN A BOILER SYSTEM

ABSTRACT It is known that during the biomass combustion in industrial systems the formation of residues containing ashes and residual carbon occurs. The content of the residues varies according to the efficiency and operating parameters of the combustion chambers. The characterization of these residues is an essential tool to identify their potential for energy reuse. The aim of this paper was to analyze the thermal behavior of the biomass and the residues yielded during the combustion process in a boiler system. For this purpose, forest biomass and ash samples have been analyzed in a laboratory and at four collection points of generation and treatment of the combustion residues (readler, hopper, scrubber, and decanter) inside the boiler of a power plant. The thermogravimetric analysis (TGA and DTA) have been carried out on all samples. Moreover, the ultimate analysis, the proximate analysis and the gross calorific value of all samples have been determined. Results show that the biomass burning efficiency in the boiler furnace was high, which was proven by the chemical composition and thermal degradation behavior of the residues collected in the readler. The scrubber’s light wastes presented chemical and energy properties (7180 kcal/kg, 75% fixed carbon content, 21% volatile content and 3.72% ash content), and thermal behavior similar to the ones found in the literature for eucalyptus charcoal. However, in order to reuse these combustion residues on reinjection or reheat systems, machine adjustments are essential to achieve burning efficiency and avoid operational problems. The decanter wastes did not show potential for energy reuse.

Perspectives of using pulmonary arterial stiffness indicators to evaluate the prognosis of patients with pulmonary arterial hypertension

the aim of the study was to characterize the mechanical properties of the pulmonary arterial wall (PA) in patients with pulmonary arterial hypertension (PAH) using magnetic resonance imaging (MRI) of the heart, and to determine their diagnostic and prognostic value. 57 patients with PAH were examined. The diagnosis of PAH was verified according to the recommendations of the ERS/ESC from 2015. All patients underwent a detailed echocardiographic (ECHO) study, MRI of the heart and right heart catheterization (RHC). To calculate the stiffness of the pulmonary artery wall, the MRI and RHC data were used. We identified a correlation between the functional class of PAH and the parameters of hemodynamic, physical performance, ECHO parameters of the right chambers. There were no differences in the stiffness of the pulmonary artery wall, depending on the functional class of PAH. Among the six stiffness indicators, only pulsation index was associated with the structural and functional parameters of the right ventricle and pulmonary vascular resistance. The MRI pulsation index is the simpleststiffness index of the pulmonary artery wall and the most promising one for evaluating the prognosis of patients with PAH.

Perspectives of using pulmonary arterial stiffness indicators to evaluate the prognosis of patients with pulmonary arterial hypertension.

The aim of the study was to characterize the mechanical properties of the pulmonary arterial wall (PA) in patients with pulmonary arterial hypertension (PAH) using magnetic resonance imaging (MRI) of the heart, and to determine their diagnostic and prognostic value. 57 patients with PAH were examined. The diagnosis of PAH was verified according to the recommendations of the ERS/ESC from 2015. All patients underwent a detailed echocardiographic (ECHO) study, MRI of the heart and right heart catheterization (RHC). To calculate the stiffness of the pulmonary artery wall, the MRI and RHC data were used. We identified a correlation between the functional class of PAH and the parameters of hemodynamic, physical performance, ECHO parameters of the right chambers. There were no differences in the stiffness of the pulmonary artery wall, depending on the functional class of PAH. Among the six stiffness indicators, only pulsation index was associated with the structural and functional parameters of the right ventricle and pulmonary vascular resistance. The MRI pulsation index is the simpleststiffness index of the pulmonary artery wall and the most promising one for evaluating the prognosis of patients with PAH.

The application of multi-wire drift chambers in cosmic ray research

Multiwire drift chambers designed for the neutrino experiment at the IHEP U-70 accelerator have found a new application in the MEPhI experiment focused on the detection of ultrahigh-energy cosmic rays. Their high durability and fine spatial and angular characteristics make these chambers perfectly suitable for such studies. The drift chambers were tested at MEPhI and used in constructing the CTUDC coordinatetracking setup, which operated together with the NEVOD water Cherenkov detector and the DECOR detector. The results of the studies of the parameters of drift chambers in the cosmic-ray flux at test benches and in the CTUDC setup are presented.

Right ventricular systolic dysfunction in patients with coronary artery disease:
 gender-related differences

Right ventricular (RV) dysfunction is one of the most significant independent predictors of prognosis in patients with coronary artery disease (CAD) presenting with and without myocardial infarction (MI). However, gender-related differences in RV function of CAD patients are still poorly understood. Aim. To elucidate gender-related differences in echocardiographic parameters of the right chambers of the heart in CAD patients. Material and Methods. 719 patients with coronary artery disease undergoing medical examination in the Federal Budgetary Institution Rehabilitation Center «Topaz» of the RF Social Insurance Fund were included in the study. All patients were assigned to two groups according to the gender: Group 1 - men (n = 432, 61 [55; 67] years), Group 2 - women (n = 287, 62 [56; 67] years). Results. The analysis of the structure and systolic function of the RV showed that RV and right atrium (RA) end-diastolic dimension, diastolic RV wall thickness, and RA area were significantly higher in men than in women (p <0.001). Thus, the prevalence of RV systolic dysfunction (SD) was similar in both groups of patients: 17.6% in men and 15% in women (p = 0.356). The independent predictors of LV SD in both groups were as follows: prior coronary artery bypass grafting (CABG), decreased early mitral flow propagation velocity (p > 0.05). However, reduced left ventricular ejection fraction (LVEF; p <0.001) was found only in men. Conclusion. The prevalence of right ventricular systolic dysfunction in patients with coronary artery disease was similar in both men and women. Men demonstrated lower values of systolic and diastolic LV function. The factors associated with RV systolic dysfunction in both groups were as follows: prior CABG and diastolic LV dysfunction. Reduced LVEF was found only in men. The results of this study can be used to assess gender-related differences in RV dysfunction in CAD patients.

Effect of Severe Obstructive Sleep Apnea on Morphology of Left-Sided Heart and Pulmonary Artery Pressure

OSA is one of the factors leading to cardio-vascular remodeling. This study was planned to compare pulmonary artery pressure and morphological parameters of left-sided chambers of heart between two groups—severe OSA and a control group. 30 consecutive subjects with severe OSA diagnosed through overnight video-synchronized attended polysomnography and 30 consecutive subjects having “low risk for OSA” were recruited in this study. The latter group served as control group. Informed consent was taken and they were screened for exclusion criteria. Their medical history was obtained and anthropometric parameters were measured. 2-D Echocardiography was done by a cardiologist following standard guidelines. Both groups were comparable with regard to age (52.2 ± 10.1 years cases; 54.5 ± 12.1 years controls; t = − 0.78; P = 0.43). 40% cases and 7% controls had history of systemic hypertension (χ 2 = 9.31; P = 0.002). Half of the OSA patients had mild to moderate tricuspid regurgitation while none among the controls. None of the subjects in either group ever had myocardial infarction. OSA subjects had larger left atrium (3.63 ± 0.43 vs. 3.16 ± 0.41 cm in control; P = 0.003), higher left ventricular end-systolic volume (53.25 ± 16.69 vs. 38.82 ± 9.36 ml in controls; P = 0.01), higher mean pulmonary artery pressure (19.41 ± 7.89 vs 14.91 ± 3.55 mmHg in controls; P = 0.04), thicker left ventricular posterior wall (1.25 ± 0.13 vs 0.65 ± 0.25 cm in controls; P < 0.001) after controlling for confounders like age, gender, body mass index and systemic hypertension. An index was calculated for the left atrial size and left ventricular volumes with body surface area. Among these indices, only left ventricular end systolic volume index was found to be higher among subjects with severe OSA after controlling for confounders like age, gender, body mass index and systemic hypertension. Severe OSA is associated with remodeling of pulmonary vasculature and left-sided chambers of the heart.

Justification of the calculation methods of the main parameters of vortex chambers

The object of research is vortex dust collectors – apparatus in which hydrodynamic regimes are realized. Advantages of using vortex apparatus: work with gases of high temperature, high degree of purification; regulation of the process of gas cleaning from dust due to regulating the secondary air flow. Among the disadvantages of vortex dust collectors are: high hydraulic resistance, the need for powerful blowing apparatus, as well as difficult operation and installation. Apparatus for swirling the flow have a different design and, depending on the gas flow rate, pressure and physicochemical properties of the gas flow at the inlet to the cleaning apparatus, this or that hydrodynamic regime is created in it. When designing vortex chambers, the following design parameters must be observed: D s /D » 0.8; D i /D s » 0.5; D w /D » 0.5 ¸ 0.8; the inclination angle of the vortex blades at the inlet of the main flow is b » 30 ¸ 60o ; the inclination angle of the secondary flow nozzles is a » 30 ¸ 45o . When calculating and designing a vortex chamber, it is necessary to fulfill the conditions for the constancy of the tangential velocity of the total flow along the entire length of the working cavity of the apparatus, ensuring the maximum possible efficiency of its functioning. Analysis of the obtained results for justification of the methods for calculating the basic parameters of the vortex chambers indicates the expediency of using such methods for calculating gas cleaning equipment. When implementing the process of cleaning dust-gas flows in vortex apparatus, not only the processes of agglomeration of dust are observed, but also the destruction of gas toxicants. Mathematical dependencies are considered to allow make predictive estimations to select the conditions of the dry dust removal process and to select the design parameters of the vortex chamber. This opens prospects for the introduction of vortex apparatus in order to reduce the industrial negative impact on the environment, namely the atmosphere.

Modeling and experiments of a soft robotic gripper in amphibious environments

This article presented the optimization parameter of a bidirectional soft actuator and evaluated the properties of the actuator. The systematic simulation was conducted to investigate the effect of the top wedged angle (the angle for the wedged shape of the actuator structure) of the chamber on the bending extent of the actuator when it is deflated. We also investigated the width of the actuator and the material combinations of the two layers with the relation to the deformation performance. A mathematical model was also built to reveal the deformation of the actuator as a function of the geometrical parameters of the inner chambers and the material properties. We quantitatively measured the bending radius and the actuation time of the actuator both in air and under water. Digital particle image velocimetry experiments were conducted under water to observe the flow patterns around the actuator. We found that the top wedged angle has a significant effect on the outward bending of the actuator when it is deflated, and 15° was found to be optimal for bending into a larger gripping space. The result shows that the actuator can deform much easier with a bigger width. Utilizing a soft gripper that was built by mounting four actuators to a three-dimensional-printed rigid support, we found that the prototype can grip objects of different sizes, shapes, and material stiffness in amphibious environments.

THREE-DIMENSIONAL MODEL OF LEFT CHAMBERS OF THE HEART BASED ON ECHOCARDIOGRAPHY DATA: AN INSTRUMENT FOR DEVELOPMENT OF TRANSCATHETER VALVES

Aim. Comparative analysis of the acquired with EchoCG method parameters of the left chambers of the heart and of mitral valve in normal state and in restrictive type of failure with further building up three-dimensional models of these variants of the fibrous anulus geometry, and of the left atrium, left ventricle and its outgoing tract. Material and methods. The study was done using 3D transthoracal and transesophageal EchoCG on Philips iE33 (Philips Healthcare, USA) in 30 patients with unchanged mitral valve (n=15) and in ischemic mitral regurgitation (n=15). Spatial configuration of the anulus fibrosus was investigated, and mitral valve, spatial and volumetric parameters of the left atrium and left ventricle. Data was processed in SciLab 4.1.2 software and exported to CATIA 5 modelling system, where the acquired curves were combined to 2 solid thin-wall models, and after linking of the surfaces — to a hard-bodied model with required thickness of the walls. Results. All studied parameters revealed significant differences (p<0,001) in groups comparison. In restrictive type of insufficiency, sizes of fibrous anulus increase: intercomissural diameter by 22%, front-back — by 13%, perimeter — by 28%, surface — by 79%. End systolic and diastolic volumes of the LV increase more than 2 times, which is related with more prominent sphericity of the LV, than normally. Increase of LA more than 1,5 times also combines with its geometry change towards sphere. Three dimensional computer model of the left heart chambers changed as a result of ischemic mitral failure, is created. The model can be implemented in creation, analysis and prediction of medical devices for the position and/or realized as the full-sized mockups, test systems and phantoms for development and education. Conclusion . The investigation of mitral valve characteristics and of the left heart chambers by method of 3D transthoracal and transesophageal echocardiography makes it to obtain the baseline data necessary for creation of 3D computed models of the anatomic area normal and disordered. Such models can be implemented in the development of implanted devices constructions, preliminary tests of medical devices and in training.

ПРОСТОРОВА ПЕРЕБУДОВА КАМЕР СЕРЦЯ ПРИ АРТЕРІАЛЬНІЙ ГІПЕРТЕНЗІЇ У МАЛОМУ КОЛІ КРОВООБІГУ

В експерименті встановлено, що пострезекційна артеріальна легенева гіпертензія призводить до розвитку легеневого серця і виражених змін планіметричних та об’ємних параметрів його камер. Виявлено, що легеневе серце характеризується розширенням його частин із переважним зростанням просторових характеристик правого шлуночка та правого передсердя. Найбільше змінені планіметричні та об’ємні параметри камер легеневого серця виявлені при його декомпенсації, для визначення якої важлива роль належить резервним об’ємам шлуночків.

Right chambers of the heart in children with pulmonary circulation hypervolemia

The ultrasound and angiographic parameters of the right chambers of the heart were analyzed in children with pulmonary arterial hypertension (PAH) associated with congenital heart defects. The investigation was conducted in relation to the functional class (degree) of PAH. Right cardiac remodeling was found to depend to a greater extent on afterload (pulmonary artery systolic pressure and pulmonary vascular resistance); moreover, diastolic dysfunction developed just in moderate (Functional Class II) PAH. It was ascertained that there was a prompter development of PAH with myocardial systolic and diastolic dysfunction in the presence of congenital malformations with arterial hypoxemia.

SPATIAL DESCRIPTION OF HEART CHAMBERS DEPENDING ON CENTRAL HEMODYNAMICS TYPES

The objective was to study the peculiarities of spatial structure of healthy heart chambers in different types of central hemodynamics. The hearts of practically healthy albino male rats have been examined which were divided into groups in according to the three types of cardiac hemodynamics. The dynamics of changes of planimetric and volumetric parameters of the heart chambers of healthy rats with different types of central hemodynamics has been studied. The endocardial surface square of the right chambers was found to be bigger than the same parameter of the left chambers(1.2 times in all the experimental groups). Volume characteristics of the left ventricle were smaller than those of the right ventricle (reserve volume of right ventricle was twice as the same indices of the left ventricle). Spatial characteristics dominated among the animals with hyperkinetic hemodynamics type.

The role of systemic inflammation and endothelial dysfunction in the development of left ventricular dysfunction in patients with chronic obstructive pulmonary disease

Summary. The aim of the study – to identify the role of systemic inflammation and endothelial dysfunction in the development of left ventricular dysfunction in patients with chronic obstructive pulmonary disease (COPD). Endothelium-dependent vasodilatation of brachial artery (EDVD), echocardiography parameters of left and right heart chambers, the concentration of pro-inflammatory and anti-inflammatory cytokines and circulating immune complexes (CIC) in plasma were studied in patients with moderate COPD. COPD patients showed a reduction of left ventricular contractile activity compared to the control group. Reducing EDVD was found in 72 % of patients with COPD. In the development of left ventricular failure involved a violation of interventricular interaction. Correlation analysis of the relationship of molecular indicators of inflammatory activity and echocardiography parameters were identified: correlation between the concentration of the CIC and the pulmonary artery systolic pressure (PASP), between the level of IL-1β and PASP, between the concentration of IL-8 and the PASP. COPD patients at an early stage of the disease to detect violations of vasoactive endothelial function, an imbalance of pro-and anti-inflammatory cytokines, increasing the concentration of CIC. Developing systemic inflammation and endothelial dysfunction contribute not only to the formation of pulmonary hypertension and chronic cor pulmonale, but also the development of left ventricular failure.

Left cardiac chambers after implantation of mitral valve prostheses “MIX”, “MEDINGE-2”, “KemCor”, and “PeriCor”

Aim. To compare ultrasound parameters of left cardiac chambers after the implantation of mitral valve prostheses “MIX”, “MEDINGE-2”, “KemCor”, and “PeriCor”, using the 10-year follow-up data. Material and methods. We analysed 2,543 echocardiography protocols of patients with mitral valve disease, who in 1995–2008 underwent the implantation of mitral valve prostheses “MIX” (n=122), “MEDINGE-2” (n=67), and biological prostheses “KemCor” or “PeriCor” (n=306). The exclusion criteria were aortal valve prosthesis, prosthesis dysfunction, and age under 18 years. Results and conclusion. In the early post-intervention period, left ventricular (LV) ejection fraction tended to decrease (p&gt;0,10); however, by the end of the first year, it was normalised. The use of biological prostheses resulted in a significant (p

Association of Plasma B-Type Natriuretic Peptide Levels with Shunt Size in Young Adults with Atrial Septal Defect

This study was designed to investigate the validity of brain natriuretic peptide (BNP) levels for the estimation of the shunt size in young adults with atrial septal defect (ASD), and to determine the relationship between BNP levels and echocardiographic parameters of right heart chambers. Fifty-six patients with ASD (mean age 22.9 ± 2.0 years) were studied. The control group consisted of 31 age-gender matched healthy volunteers (mean age 22.7 ± 1.9 years). Coventional echocardiography, tissue Doppler imaging (TDI) and plasma BNP level measurement was performed in all participants. The ratio of pulmonary to systemic blood flow (Qp/Qs) was measured noninvasively using transthoracic echocardiography. Plasma BNP levels were significantly higher in ASD patients than in controls (42.9 ± 29.4 vs. 8.3 ± 2.6 pg/mL, P < 0.05). Pulmonary artery pressure (PAP) (P = 0.0001), right atrium (RA) volume (P = 0.0001), and right ventricular end-diastolic volume (RVEDV) (P = 0.0001) values were higher in ASD patients. There was a powerful correlation between plasma BNP levels and Qp/Qs ratio (r = 0.71, P < 0.0001). The plasma BNP levels significantly correlated with PAP (r = 0.61, P < 0.0001), RA volume (r = 0.54, P < 0.0001), RVEDV (r = 0.55, P < 0.0001), and right ventricular myocardial performance index (r = 0.50, P < 0.0001). This study shows that there is a significant correlation between right heart echocardiographic parameters and concentrations of BNP in the plasma of young adults with ASD. BNP levels may provide a supplemental data to predict of shunt size in these patients.

Dosimetric system for determining the emission rate of gas-aerosol radioactive impurity during a radiological accident

A dosimetric system for determining the rate at which gas-aerosol radioactive impurities are discharged during a radiological emergency is examined. It is shown that the optimal system for evaluating the rate of discharge is one that consists of flow-through and closed (hermetic) ionization chambers. The addition of a xenon spectrometer to the system makes it possible to determine the partial rate of emission of individual radionuclides and the total emission rate of all nuclides. The optimal parameters of the ionization chambers making it possible to record the emission rate of a radioactive impurity with air flow rate to 12 m/sec against background dose rate up to 200 Sv/h are found.

Burning of hydrogenous mixtures in the model of an internal-combustion-engine chamber

The integral characteristics of burning of stoichiometric and lean hydrogenous mixtures in a cylindrical chamber at initial pressures of 0.024 to 1 MPa have been investigated. The propagation of the flame has been visualized and the distributions of its velocity and the running parameters of burning have been obtained. It has been shown that in synthesis-gas-based mixtures, the flame front has a "cellular structure;" its characteristic dimension grows with propagation of the flame. A method for determining the shape factor, which makes it possible to explain certain experimental regularities of burning, has been proposed. The results of the work can be used in selecting the parameters of mixtures and combustion chambers of heat engines operating on modified fuels.

Review of the trigger systems of the ATLAS and CMS detectors at the LHC

The characteristics and principles of multilevel trigger systems of the ATLAS and CMS detectors are considered. Calorimeter algorithms for particle identification are described. The parameters of the trigger chambers used for muon track identification are presented. Methods for designing custom processors based on custom integrated circuits and programmable arrays are described. The parameters of the trigger systems of the ATLAS and CMS detectors are compared.