Dynamics of the plasma electrolytic polishing process of austenitic steel AISI 304 in a solution of ammonium sulfate

Modern industrial technological processes together with scientific research activities require the special preparation of the metal surfaces for the further treatments. At present time the variety of techniques for the metal surface processing exist. Among them one could outline the plasma electrolytic polishing (PEP) due to its capability together with the decoration effect to enhance the surface properties. Despite the number of papers published in different journals the PEP stays an innovative surface treatment and requires further study to obtain optimal processing regimes. In present contribution the experimental study of PEP process dynamics with further numerical analysis of physical aspects for steel AISI 304 in a solution of ammonium sulfate with the mass fraction of 3% is given. After analyzing the experimental results the optimal PEP regime for the steel AISI 304 in a solution of ammonium sulfate with the mass fraction of 3% was identified.Сучасні виробнично-технологічні процеси разом з науково-дослідницькою діяльністю вимагають спеціальної підготовки металевих поверхонь для подальшої обробки. На цей час існує безліч методів обробки поверхні металу. Серед них можна виділити плазмове електролітичне полірування (PEP) через його здатність покращення властивостей поверхні з ефектом полірування. Незважаючи на число публікацій в різних журналах, PEP залишається інноваційним методом обробки поверхні та потребує подальшого вивчення для отримання оптимальних параметрів полірування. У цій статті представлено експериментальне дослідження динаміки процесу PEP з подальшим чисельним аналізом фізичних властивостей сталі AISI 304 у розчині сульфату амонію з масовою часткою 3%. Після аналізу експериментальних результатів було визначено оптимальний режим PEP для сталі AISI 304 у розчині сульфату амонію з масовою часткою 3%.Современные производственно-технологические процессы вместе с научно-исследовательской деятельностью требуют специальной подготовки металлических поверхностей для дальнейшей обработки. В настоящее время существует множество методов обработки поверхности металла. Среди них можно выделить плазменную электролитическую полировку (PEP) из-за ее способности улучшения свойств поверхности с эффектом полировки. Несмотря на число публикаций в разных журналах, PEP остается инновационным методом обработки поверхности и требует дальнейшего изучения для получения оптимальных режимов полирования. В данной статье представлено экспериментальное исследование динамики процесса PEP с дальнейшим численным анализом физических свойств стали AISI 304 в растворе сульфата аммония с массовой долей 3%. После анализа экспериментальных результатов был определен оптимальный режим PEP для стали AISI 304 в растворе сульфата аммония с массовой долей 3%

Structure, Substructure, Hardness and Adhesion Strength of Multiperiod Composite Coatings MoN / CrN

A comprehensive study of the influence of the thickness of the layers, Us and PN on the structural engineering to obtain high mechanical properties in multilayer composite MoN / CrN vacuum-arc coatings has been conducted by means of scanning electron microscopy with energy analysis, X-ray diffraction studies microindentation and scratch testing methods. It has been determined that in the studied PN (2- 30) 10 – 4 Torr, the content of nitrogen in the coatings varies from 6.3 to 33 at. %, which leads even at the greatest nitrogen content to the formation of lower phase by nitrogen, -Mo2N and isostructural CrN with the vacant sites in the nitrogen sublattice. The increase of thickness of the layers applied on the substrate in a stationary state promotes the increase of nitrogen content. Along with this, the lowest microdeformation and the average size of crystallites are formed at Ub – 300 V, which defines the achievement of greater hardness of 35 GPa and high adhesion strength, which resists the destruction, Lc5 187.6 N

Degradation of electrooptical characteristics of serial GaP light-emitting diodes, caused by fast electrons

The study of electrical and optical characteristics of GaP LEDs irradiated with electrons (E = 2 MeV, Ф = 0…10¹⁵ cm⁻²) was performed. Especial interest was focused on appearing of S-type instability in current-voltage characteristics and its mechanism in accord with the model by K. Maeda. Made in this work was the analysis of changes in the concentration of deep recombination levels caused be irradiation. The coefficient of radiation damages of charge carrier lifetime in GaP was estimated (kτ = 1.5·10⁷7 s·cm⁻²). It was discovered that the luminescence intensity recovering after isochronous annealing possesses two stages. Heating the diodes up to T > 350 °C leads to destruction of p-region in the diode and deterioration of lens optical transmission

Acoustic-stimulated relaxation of GaAs₁₋хPх LEDs electroluminescence intensity

The effect of ultrasonic (US) treatment on electroluminescence of initial and irradiated with 2-MeV electrons (Φ = 8.24·10¹⁴ e/cm²) GaAs-GaP LEDs grown on solid solution base was studied. It was found that luminescence intensity of samples previously loaded with US increased during long-term storage (t = 15 h). Passing the current through the diode generates the relaxation process of radiation brightness falling followed by the growth when ultrasound is switched on. The results of calculation of the dislocation density responsible for electroluminescence quenching within the region of electroluminescence degradation are adduced. It was found the ultrasound effect on diodes irradiated with high-energy electrons

Prosthetic stomatitis in patients with diabetes mellitus: correction of psycho-emotional stress

A high level of chronic emotional stress affects the occurrence and increases the severity of diseases of the oral mucosa and internal pathology. The aim of the work is to increase the effectiveness of the treatment of prosthetic stomatitis in patients with diabetes mellitus against the background of psycho-emotional stress by correcting it. To objectify the state of psycho-emotional stress, in 2005-2015 and in 2022 psychological testing was carried out by the D. Taylor method on 230 people aged 19-70 years, among whom 85 patients were diagnosed with diabetes mellitus – the main group; 145 people were without internal diseases – two control groups. General examination and treatment of patients of the main group – 46 women and 39 men aged 19-70 years was carried out by endocrinologists according to the relevant protocols. Dental examination and treatment of prosthetic stomatitis was carried out in 12 patients with diabetes mellitus who had a high level of general anxiety according to the D. Taylor method. Own method of treatment: after the correction of the prosthesis, sanitation of the oral cavity, applications of thiotriazoline 2% ointment, a course of 7-10 days on the areas of the prosthetic bed, most often subject to trauma were prescribed. For general therapy, an additional stress-protective drug which corrects psycho-emotional stress in patients with diabetes mellitus was prescribed, thiotriazoline, orally, for 30 days. In patients of the main group, a high level of general personal anxiety was recorded in 21.63% of respondents and an average level with a tendency to high – in 54.29%. In many cases, the dentist should know the level of the patient's psycho-emotional stress in order to justify an individual approach to therapeutic measures and maintenance therapy in the choice of drugs and methods. The proposed method of treatment of prosthetic stomatitis has an individual approach, includes the stress-protective drug thiotriazoline, which corrects psycho-emotional stress, allowing to achieve a stable remission of the disease

Structure, Substructure, Hardness and Adhesion Strength of Multiperiod Composite Coatings MoN / CrN

A comprehensive study of the influence of the thickness of the layers, Us and PN on the structural engineering to obtain high mechanical properties in multilayer composite MoN / CrN vacuum-arc coatings has been conducted by means of scanning electron microscopy with energy analysis, X-ray diffraction studies microindentation and scratch testing methods. It has been determined that in the studied PN (2- 30) 10 – 4 Torr, the content of nitrogen in the coatings varies from 6.3 to 33 at. %, which leads even at the greatest nitrogen content to the formation of lower phase by nitrogen, -Mo2N and isostructural CrN with the vacant sites in the nitrogen sublattice. The increase of thickness of the layers applied on the substrate in a stationary state promotes the increase of nitrogen content. Along with this, the lowest microdeformation and the average size of crystallites are formed at Ub – 300 V, which defines the achievement of greater hardness of 35 GPa and high adhesion strength, which resists the destruction, Lc5 187.6 N

Structure and Mechanical Properties of TiAlSiY Vacuum-Arc Coatings Deposited in Nitrogen Atmosphere

The effect of a negative bias potential applied to the substrate on elemental composition, structure, and mechanical properties of vacuum-arc TiAlSiY nitride coatings is investigated by different methods. It is ascertained that applying a high (up to –500 V) bias voltage leads to a selective sputtering of target as well as significant microdeformation of the coating, small-sized growth of crystallites, and their preferred orientation along the [110] direction. In this case, the coating deposited has a low hardness H = 6.95 GPa and propensity to intense wear under scratch and tribological tests. Crystallites with stoichiometric composition ~140 nm in size and [111] preferred orientation perpendicular to the surface of growth are formed at the bias potential about –200 V, and superhard (H = 49.5 GPa) and wear-resistant coatings are grown under such conditions. The mechanisms of formation of the structure of multielement coatings are discussed. It is shown that for- mation of an amorphous phase and nanocrystal [110] texture takes place at a high bias potential owing to the process of radiation-stimulated selective spraying of the target. Formation of microstrained crystallites 10 nm in size caused by the weakening of interatomic bonds is observed in the coating under such deposition condi- tions, and it leads to the decrease in coating hardness and fast destruction during tribological testing. Sub- stantial bias voltage dependence of deposited coating properties is established in our investigations

Національна доповідь про стан і перспективи розвитку освіти в Україні: монографія (До 30-річчя незалежності України)

The publication provides a comprehensive analysis of the state and development of national education over the 30 years of Ukraine’s independence, identifies current problems in education, ascertains the causes of their emergence, offers scientifically reasoned ways to modernise domestic education in the context of globalisation, European integration, innovative development, and national self-identification. Designed for legislators, state officials, education institutions leaders, teaching and academic staff, the general public, all those who seek to increase the competitiveness of Ukrainian education in the context of civilisation changes.У виданні здійснено всебічний аналіз стану і розвитку національної освіти за 30-річний період незалежності України, визначено актуальні проблеми освітньої сфери, виявлено причини їх виникнення, запропоновано науково обґрунтовані шляхи модернізації вітчизняної освіти в умовах глобалізації, європейської інтеграції, інноваційного розвитку та національної самоідентифікації. Розраховано на законодавців, державних управлінців, керівників закладів освіти, педагогічних і науково-педагогічних працівників, широку громадськість, усіх, хто прагне підвищення конкурентоспроможності української освіти в контексті цивілізаційних змін

DEONTOLOGY AND PROFESSIONAL ETHICS IN DENTIST’S PROFESSION

Medicine is a sphere of activity where there are no trivialities, no unnoticed acts, views, experiences. All contact between the doctor and the patient during the course is a system of human relationships, so the outcome of any treatment depends on their level and quality. Through cooperation with a physician, the patient takes an active position, assumes responsibility for his or her health and takes part in recovery. An inextricable set of manual skills and communication skills determines the professionalism of the physician, forming a solid foundation of trust in the patient. The purpose of the investigation is to consider the specifics of issues of deontology and professional ethics in the work of a dentist in modern conditions. The professional morale of the doctor is the subject to the goal of health and human life. Hence the well-known ethical principle of therapy: "Non nocere". The basic moral principle states: "Do not harm the patient by providing the patient health care." At the clinical departments of the Medical Academy, one of the goals of training future specialists is the tradition of treatment, when the doctor brings benefits to the patient and does not harm. These approaches are implemented by the teacher during the theoretical part of the class, and especially on the practical one. When studying the section "Periodontology" at the departments of Therapeutic and Surgical Dentistry of UMSA, the ethical principle "Non nocere" is used at the stages of diagnosis of periodontal tissue diseases, the appointment of general treatment, when choosing local therapies, especially in the application of surgical methods (closed and open curettage, , cryo-curettage, gingivectomy, scapular operations, and others). Students learn to apply a differentiated and individualized approach to each patient. For the modern physician, the highest values must be universal values, therefore, in the process of decision-making, he can not be guided by the notions of moral and other value-added character. The doctor acts as an expert who, based on clinical data and experimental laboratory findings, establishes a final diagnosis, explaining to the patient all that relates only to his disease, leaving out the attention of the patient's vital problems. At the departments of Surgical and Therapeutic Dentistry, during classroom practical classes in the clinic, students, from the first steps of communication with patients, develop basic ethical and moral principles. Students independently conduct a subjective and objective examination of patients, learn to correctly collect the anamnestic data of the disease and life of patients. They analyze the data of the anamnesis, ponder them and make a plan of diagnosis and plan of treatment of their patients. After the differential diagnosis and the establishment of a final clinical diagnosis, under the guidance of the teacher, medical manipulations are carried out. One of the main ethical and moral principles is the preservation of medical secrets - the physician should not disclose personal information about the patient, as well as express doubts regarding his recovery. In order to gain the full confidence of the patient, the doctor must also preserve family secrets. Medical secrecy is the information the doctor receives during his duties. Starting with junior courses at profile dentistry departments, students learn that the medical secrecy involves the non-disclosure of disease data not only to others, but in some cases to the patient himself. It is necessary to protect the patient from the information that may harm his mental condition and the ability to fight the disease. When using information constituting a medical secrecy in the educational process, in research work, in particular, in cases where they are published in a special literature, anonymity of the patient should be ensured. Providing medical stomatological services is a complex of activity that requires a lot of knowledge, skills, technology, work from biological elements that can be unpredictable, as well as knowledge of medical psychology. The ethical duty of a dentist is to respect the patient's right to make independent decisions. At the same time, the actions of a dentist are inevitably influenced by such human factors as subjectivity of judgment, fatigue, lack of time, mistakes of other people, technical malfunction of equipment, etc. The peculiarity of the activity of the dentist at the present stage is the comprehensive implementation of the principles of bioethics, which could be considered universal: it is the autonomy of the individual, informed consent, voluntariness, confidentiality, dignity, integrity, vulnerability, justice. Patients want to believe that their doctor always establishes an absolutely accurate diagnosis and never misses the treatment, but it is simply impossible. The combination of human relationships and technological moments increases the likelihood of medical errors. Ethics requires that the physician inform the patient of his or her mistakes if these errors affect the health of his or her health. Open recognition and analysis of mistakes are beneficial both to the patient and to the dentist, and to the whole practice. Educational medical institutions of the III and IV levels of accreditation, which carry out post-graduate education for cadets and interns, pay great attention to practical activities. The reception of patients is carried out by teachers, along with young doctors or young doctors independently admit patients under the control of a teacher-tutor. Such situation often does not suit patients. They seek quality skilled assistance and do not want to be "trained" to doctors who have only received diplomas. Employees of the higher medical school use the knowledge of ethics and deontology in the relationship between the physician and the patient, and help to build a patient's confidence in a young specialist. The senior teacher explains to the patient the need to attract young doctors to treatment, defines the purpose of this collaboration as a transfer of experience. In modern medicine, in particular, in dentistry, the patient takes part in the discussion of the treatment process, acquaints himself with the plan of examination and treatment, and gives his written consent to this at the completion of medical documentation, in particular, an outpatient card for a dental patient. The dentist interacts with the patient as a specialist and performs all necessary manipulations. With this aim in improving the medical skills of students and interns, discussions are held with their colleagues, discussions with older and more experienced doctors of complex diseases, clinical examinations, clinical conferences are practiced [4, 5]. Teachers of the dental departments of the academy always educate the students and intern doctors such qualities as a doctor, such as friendly fellowship, availability for contacts, readiness to seek help and help a colleague, justice, and high professionalism. It should be noted that the culture of behavior, together with professional competence, forms the authority of the physician both in the team and among patients. A doctor of proper clinical education is always grateful to his mentors. The key to friendly collegial relationships is deep respect, goodwill and trust, adherence to the established subordination, discipline

Отримання, структура і властивості покриттів на основі Al2O3, отримані магнетронним методом

Нанесення покриттів Al2O3 та багатошарових покриттів Al2O3/ZrO2 здійснювали магнетронним методом шляхом розпилення відповідних металевих мішеней в середовищі суміші газів кисню та аргону. Мікроструктура поперечних зрізів, визначення товщини і елементний склад отриманих покриттів досліджували методом трансмісійної та растрової електронної мікроскопії. Морфологія поверхні зразків покриттів Al2O3 вивчалася методом скануючої зондової мікроскопії. Показано, що сформовані покриття як Al2O3, так і багатошарове покриття Al2O3/ZrO2 мають стовпчасту структуру з орієнтацією стовпців перпендикулярно поверхні. Стовпчаста структура багатошарових покриттів не порушується при переході від шару до шару. Поверхня покриттів складається з глобул діаметром близько 20 нм. Методом імпедансної спектрометрії встановлено, що покриття Al2O3 має діелектричні властивості. Таким чином, було показано, що магнетронним методом можна наносити якісні багатошарові діелектричні покриття, які можуть бути використані в якості термобар’єрних покриттів для захисту лопаток високотемпературних щабель турбін авіаційних двигунів.Al2O3 and Al2O3/ZrO2 multilayer coatings were deposited by the magnetron method by sputtering the corresponding metal targets in a mixture of oxygen and argon gases. The microstructure of the cross sections to determine the thickness and elemental composition of the obtained coatings was studied by transmission and scanning electron microscopy. The surface morphology of Al2O3 coating samples was studied by scanning probe microscopy. It is shown that the formed Al2O3 coating and the Al2O3/ZrO2 multilayer coating have a columnar structure with the columns oriented perpendicular to the surface. The columnar structure of multilayer coatings is not violated during the transition from layer to layer. The coating surface consists of globules with a diameter of about 20 nm. It was found that the Al2O3 coating has dielectric properties using the method of impedance spectrometry. Thus, it was shown that the magnetron method can be used to apply high-quality multilayer dielectric coatings, which can be used as thermal barrier coatings to protect the blades of high-temperature stages of aircraft engine turbines