79 results match your criteria: "National Technical University "Kharkiv Polytechnic Institute"[Affiliation]"

This study investigates how laser-induced surface modifications influence key properties such as wear resistance, hardness, and friction in dry and lubricated conditions. The research applies nanosecond pulsed laser treatment to create random, quasi-random, quasi-periodic, and periodic surface structures on the steel surface, aiming to enhance the wear resistance and reduce the coefficient of friction (COF). The frictional performance between the carbon steel ball and the texturized surface was evaluated, including an analysis of the initial friction phase contact (single, double, and multi-contact), with the surface topography assessed before and after wear.

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This article presents the results of the research on real coal charges of different compositions intended for coking with loading into the chamber by the stamping method. The results of the study established that with an increase in the content of coal at a low stage of metamorphism and a decrease in the content of coal at a high stage of metamorphism in the charges, a decrease in the quality indicators of the coke obtained from them leads to a decrease in the yield of coke. At the same time, there is a gradual decrease in the compaction of the charges from 22.

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Wash oil is a fraction obtained by the distillation of coal tar and is primarily used for the absorption of light oil from coke oven gas. During operation, the oil undergoes polymerization and loses some components, necessitating the removal of the used oil and its replacement with fresh wash oil. The rheological properties of the studied oils were determined using a Brookfield DV2T rotational controlled-shear rate rheometer.

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The homogeneity of the microwave magnetic field is essential in controlling a large volume of ensemble spins, for example, in the case of sensitive magnetometry with nitrogen-vacancy (NV) centers in diamond. This is particularly important for pulsed measurement, where the fidelity of control pulses plays a crucial role in its sensitivity. So far, several magnetic field-forming systems have been proposed, but no detailed comparison has been made.

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Article Synopsis
  • Scientists are working hard to create a vaccine for hepatitis C, a virus that still affects many people worldwide despite better treatments.!
  • The paper talks about different types of vaccine approaches, like using inactivated virus or newer methods like DNA and mRNA, to find the best way to prevent infection.!
  • Developing a safe and effective vaccine is challenging because the virus can change a lot and trick the immune system, but there’s hope with new technologies and research progress.!
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Pressmud compost is an organic soil amendment and a robust technology that has potential to restore toxic metals (TMs) polluted soil. The application of organic amendments including pressmud compost in soil for toxic metals (TMs) alleviation have gained considerable attention as compared to traditional methods among the scientific community. In this review paper, we summarized the literature aiming to understand the immobilization efficacy of TMs such as cadmium, lead, chromium, copper, nickel, iron, zinc, and manganese, underlying mechanisms, plant growth, essential nutrients and soil health under pot, field and incubation conditions which has not been well investigated up-to-date.

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Objective: Aim: To investigate the dynamics of health and physical development indicators of cadets during their field training exercises of various durations.

Patients And Methods: Materials and Methods: The research involved 246 cadets (men) of the 1st-4th training years, who were majoring in the specialty 253 referred to as "Military Management" (specialization "Management of Tank Troops"). The research was conducted in 2022-2023 during field training exercises lasting 2 and 4 weeks.

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By one-pot four- and three-component Ugi reactions involving convertible isocyanides and unexplored pyrrole-containing β-chlorovinylaldehyde, a small library of 20 bisamides with unusual behavior in post-Ugi transformations was prepared and characterized. Surprisingly, a well-documented approach to obtain peptide-containing carboxylic acids through acid hydrolysis of the convertible isocyanide moiety in the Ugi bisamides proceeded in an unexpected manner in our case, leading to the formation of derivatives of amides of heterylidenepyruvic acid. An optimized synthetic protocol for this transformation was elaborated and a plausible sequence involving the elimination of the 2-chloroacetamide moiety and the conversion of the β-chlorovinyl fragment into a vinyl one is provided.

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Pot experiment was performed aimed to assess the comparative role of charcoal, biochar, hydrochar and thiourea-vegetable modified biochar at 1 and 2 % doses, and <1 mm particle size on the bioavailability of Cd, Pb, As, Ni, Cu and Zn, and enhance NPK, and mustard growth in a slightly alkaline polluted soil. Furthermore, machine learning method was used to examine the systematic evaluation of the impact of feature selection based on Pearson's correlation on the performance of the linear regression model. The results revealed that maximum fresh and dry biomass of mustard was observed by 26.

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Article Synopsis
  • This work introduces an open-source software package that simulates X-ray reflectivity (XRR) and helps reconstruct film structures from measured XRR curves.
  • The software features a user-friendly interface for interactive simulation and uses a recursive method based on Fresnel equations, with tools for modeling multilayer structures.
  • The latest version includes enhancements like automatic fitting for XRR curves using an improved optimization algorithm and a new single-window interface for a better user experience.
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Objective: Aim: data study on the results of treatment of acute non-specific purulent-destructive pleura diseases with the purpose of further improvement of its results on the basis of improvement of diagnostics, identification of factors of disease prognosis and by implementing differential tactics of surgical treatment with the use of minimally invasive interventions.

Patients And Methods: Materials and Methods: We have studied modern literary sources on the topic of current trends in the treatment of acute pleural empyema and its complications. The studied material is summarized and presented in the form of a literature review in this article.

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Young GI angle: Career in terms of war.

United European Gastroenterol J

April 2024

Department of Pediatric Hepatology and Comorbidities, Institute of Pediatrics, Obstetrics, and Gynecology, Kyiv, Ukraine.

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Alloys of the Fe-Cr-C-B-Ti alloy system are characterized by brittleness, which can be eliminated by the copper alloy, while corrosion resistance and abrasive wear resistance are significantly reduced. In this article, comprehensive investigations are carried out on the microstructure and mechanical properties of the proposed high-copper boron-containing alloy 110Cr4Cu7Ti1VB. Systematic theoretical and experimental studies encompassed thermodynamic calculations in ThermoCALC, production of flux-cored wires for hardfacing and welding, receipt of SEM images, acquisition of load and unload diagrams (discharge) via instrumental indentation on various phases of the deposited metal, and determination of chemical composition at indentation points through local chemical analysis.

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Unlabelled: Aim In the current study, hemocompatibility of three major commercially available types of carrageenans (ι, κ and λ) was investigated focusing on eryptosis.

Materials And Methods: Carrageenans of ι-, κ- and λ-types were incubated with washed erythrocytes (hematocrit 0.4%) at 0-1-5-10 g/L for either 24 h or 48 h.

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Hypertensive Heart Disease: A Narrative Review Series-Part 3: Vasculature, Biomarkers and the Matrix of Hypertensive Heart Disease.

J Clin Med

January 2024

Medical Outpatient Department and Hypertension Clinic, ESH Hypertension Centre of Excellence, University Hospital Basel, 4031 Basel, Switzerland.

Over the last few decades, research efforts have resulted in major advances in our understanding of the pathophysiology of hypertensive heart disease (HHD). This is the third part of a three-part review series. Here, we focus on the influence of high blood pressure on the micro- and macroalterations that occur in the vasculature in HHD.

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Statistics show that the inhabitants of Poland are producing increasingly more household waste. This article attempts to determine the current level of development of Poland in the field of waste management concerning other EU countries and partner countries; identify trends in the mass of generated, segregated, and mixed municipal waste; and obtain an idea of the attitude of the Polish population toward sorting waste at the source to bring the country to a higher level of waste management. The empirical base is statistical data published on the website of the EU Data Explorer and the Central Statistical Office.

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A method for correcting the matrix effect by measuring the intensity of fluorescent radiation and its absorption by the sample material in the same x-ray optical scheme is proposed. The use of a complex secondary Ag-Ge emitter as a primary radiation source provides a low detection limit for a wide range of chemical elements from Ca (Z = 20) to Mo (Z = 42) in the K-series and from Cd (Z = 48) to Bi (Z = 83) in the L-series. To measure the absorption, the radiation of an additional secondary emitter is used, of which the wavelength can be varied in the range from 0.

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In this paper, we consider new quantum mechanisms for selective detection in complex gaseous media which provide the highest possible efficiency of quantum sensors and for the first time analyze their nature. On the basis of these quantum mechanisms, the concepts of quantum detection and innovative methods of analysis are developed, which are virtually impossible to implement in the conventional conductive sensors and nanosensors. Examples of original solutions to problems in the field of detection and analysis of human breath using point-contact sensors are considered.

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Objective: The aim: To increase the efficiency of surgical treatment of patients with chronic lung abscesses by developing mini-invasive methods of surgical treatment using electrosurgical technologies.

Patients And Methods: Materials and methods: Conducted study of the results of surgical treatment of 78 patients with chronic lung abscesses operated from 2011 to 2021. Patients were divided into two groups: the main group (37 patients who were treated using developed technologies) and a comparison group (41 patients, treated using traditional tactics).

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Background And Purpose: The development of vaccines against the SARS-CoV-2 virus has become a big challenge for many countries in 2020-2022. mRNA vaccines were shown to be effective and safe and have been widely used worldwide in the fight against the COVID-19 pandemic. The fundamental factor in creating mRNA vaccines, which ensures effective delivery of mRNA to the host cells, is the composition of lipid nanoparticles, namely the presence of ionized charged lipids, which ensures the binding of mRNA molecules.

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Choice of the Miniature Inertial Optomechanical Sensor Geometric Parameters with the Help of Their Mechanical Characteristics Modelling.

Micromachines (Basel)

September 2023

Department of Quantum Metrology, Institute for Quantum Technologies, German Aerospace Center (DLR e.V.), 2022 Wilhem-Runge-Straße 10, 89081 Ulm, Germany.

In this paper, the mechanical characteristics of a miniature optomechanical accelerometer, similar to those proposed for a wide range of applications, have been investigated. With the help of numerical modelling, characteristics such as eigenfrequencies, quality factor, displacement magnitude, normalized translations, normalized rotations versus eigenfrequencies, as well as spatial distributions of the azimuthal and axial displacements and stored energy density in a wide frequency range starting from the stationary case have been obtained. Dependencies of the main mechanical characteristics versus the minimal and maximal system dimensions have been plotted.

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The factors affecting the mechanical strength of coal and coal charges, deviations of the crushing capacity coefficients' actual values of coal charges from their calculated values, and the possibility of categorizing coal in relation to the degree of its resistance to crushing have been explored. The dependence permitting satisfactory precognition of the HGI value of the coal charge placed on the data of the crushing capacity coefficients of its ingredients was settled. The effect of the grinding ability of coal on its quality indicators, namely the degree of metamorphism, petrographic and elemental composition has been examined in this article.

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The classical approach of James and Brindley for determining the shielding of a nucleus by electrons from the atomic form factor of the scattering of x rays is generalized for atoms in a bound state. It is shown that for chemical elements with atomic number Z < 10, the ratio of the peaks of coherent IR and incoherent IC scattering in the range of (sin θ)/λ from 0.7 to 2.

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Hypertensive Heart Disease: A Narrative Review Series-Part 2: Macrostructural and Functional Abnormalities.

J Clin Med

September 2023

Medical Outpatient Department and Hypertension Clinic, ESH Hypertension Centre of Excellence, University Hospital Basel, 4031 Basel, Switzerland.

Hypertensive heart disease (HHD) remains a major global public health concern despite the implementation of new approaches for the management of hypertensive patients. The pathological changes occurring during HHD are complex and involve the development of structural and functional cardiac abnormalities. HHD describes a broad spectrum ranging from uncontrolled hypertension and asymptomatic left ventricular hypertrophy (LVH), either a concentric or an eccentric pattern, to the final development of clinical heart failure.

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