Journals of Rezekne Academy of Technologies
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FREQUENCY ANALYSIS OF AN ARM OF MACPHERSON SUSPENSION ON A PASSENGER CAR
The smoothness, ride comfort, safety and handling of the car depends on the manner of suspension design and its corresponding details. One of main functions of the arm and the rubber bushings mounted on it is to reduce the vibrations and the noise transferred from the road to the passenger car components. This article presents the results of a frequency analysis of an arm of the MacPherson front independent suspension. For this purpose, three-dimensional geometric models of the arm and rubber bushings are created via finite element analysis (FEA) software SolidWorks, where Skoda Octavia passenger car was used as a prototype. The axial, radial and torsional stiffness of the rubber bushings were determined through analytical dependences and FEА. The obtained results had been used for calculation of the natural frequencies and mode shapes of the arm which were compared with experimentally obtained data
COMPARATIVE ANALYSIS ОF GEOMETRIC DEVIATIONS IN CONTACT MEASURING INSTRUMENTS FOR CONTROL AND LASER CONTACTLESS SCANNING
The factors affecting the dimensional accuracy of 3D scanning using a measuring arm with an integrated scanner and a custom open source 3D printer using FDM technology are researched in this paper, with the purpose of isolating and reducing the sources of errors affecting the results. A consumer 3D printer is analyzed in terms of achieving accurate physical dimensions, consistent shapes, and predictable surface coverage.
DETENTION IN THE LEGISLATION OF EUROPEAN STATES
The article is devoted to the topical issue of the theory and practice of criminal procedure: the analysis of the problems of the legal regulation of procedural coercive measures - detention and arrest. The authors outline both the constitutional framework of both procedural means and the topicalities of their legal regulation, and also summarize the directives of the Council of Europe and the Parliament. The problem of terms of detention and their review has been defined, guarantees of the rights of detained persons, incl. guarantees of the rights of minor children.At the end of the article, the conclusions and some proposals for the improvement of the legal framework in the Latvian Criminal Procedure Law and the Criminal Procedure Code of the Russian Federation are summarized
IMPROVEMENT OF OPERATIONAL PROCESSES BY ENSURING WORK SAFETY IN PRODUCTION
the article analyzes the improvement of operational processes by ensuring the safety of work in production. The problem raised in the research: how to ensure work safety by improving the company\u27s operational processes in production? The object of work is the possibilities of improving operational processes by ensuring work safety. The aim of the work is to analyze the possibilities of improving operational processes by ensuring work safety in production. Job objectives: to analyze the possibilities of improving operational processes by ensuring work safety from a theoretical aspect; to investigate the possibilities of improving operational processes by ensuring work safety in the production company; prepare a plan for the improvement of operational processes by ensuring work safety in production. Research methods: analysis of scientific literature and other informational sources; data collection and systematization method; descriptive analysis method used to report research data; the summarization method is used to evaluate the results of the analysis; the research uses data analysis and observation method.After conducting the research and analyzing the measures applied in the operational processes, ensuring the safety of work in production, a plan for improving the operational processes was prepared and presented, which offers specific measures for increasing the efficiency of the processes and reducing the risk of accidents. The measures implementation plan is designed to solve existing problems in the company\u27s operational processes, offering recommendations on how to reduce or completely eliminate accidents by ensuring work safety. The proposed plan will help minimize the risk of accidents at work by ensuring work safety in operational processes. The created plan for improving operational processes with measures by ensuring work safety and reducing the risk of accidents at work is universal and can be applied in other manufacturing companies that seek to improve operational processes by ensuring work safety
INVESTIGATION OF THE STRUCTURE OF ALSI25CU4CR AND ALSI25CU5CR ALLOYS
The hypereutectic aluminium-silicon alloys AlSi25Cu4Cr and AlSi25Cu5Cr are heat treated T5, T6 and T7. The quenching of the alloys was carried out under the same conditions. Artificial aging at T5 was carried out at a temperature of 180º C for 2, 4 and 6h, and at T6 at 180º C for 8, 10, 12 and 14h. The artificial aging of the studied compositions at T7 was carried out at a temperature of 370º C for 20, 40 and 60 min. The influence of heat treatment on the size, shape and distribution of primary and eutectic silicon crystals in the alloy structure was investigated. It was established that the proposed heat treatment regimes do not lead to a significant change in the shape and size of the primary silicon crystals, but contribute to their uniform distribution in the structure of the studied alloys. Rounding of the silicon crystals in the composition of the eutectic of the investigated alloys was observed
THE RIGHT TO A FAIR TRIAL IN THE SHADOW OF PANDEMIC RESTRICTIONS
The spread of Covid-19 virus infection, in 2020 Latvian legislator adopted several legal norms expanding the possibilities of courts to hear the case in written proceedings or videoconferencing at the expense of restrictions to the oral hearing in presence of the parties. The authors argue why the application of these restrictions, set out in the Covid-19 Infection Control Act (in Latvian – “Covid-19 infekcijas izplatības pārvaldības likums”) may result in human rights violations, and make suggestions for better regulation so that the fight to protect public health is not conducted at the expense of unreasonable restrictions on the right to a fair trial and privacy
EVALUATION OF HEALTHY LIFESTYLE HABITS AND WELLNESS OF UNIVERSITY STUDENTS IN A CROSS-SECTION OF FOUR ACADEMIC YEARS
Statistics on healthy lifestyle habits of Latvian population indicate that the number of adults who engage in sufficient physical activity is decreasing, and also for university students the succession of minimum physical activity is not fully ensured. Latvian National Development and Sports Policy Guidelines (Latvijas Vēstnesis, 2022), as well as other binding health policy documents contain references towards the need to support the healthy lifestyle and wellness of university students, especially highlighting the insufficient level of physical activity and emotional wellness among Latvian population, including students. The problem issue exists in the long-term spectrum, and for various reasons it is only partially possible to implement in universities the measures stated in policy documents. The aim of the study: to analyse students\u27 healthy lifestyle habits and wellness dynamics over four years of studies, assessing the dynamics of healthy lifestyle habits and wellness level depending on the year of study, students\u27 age and the study programme. In each academic year, the first- and second-year students were involved in the survey, a total of N=455 respondents. Research methodology: a tailored survey (Robbins, et.al., 2011), students\u27 self-assessment of healthy lifestyle habits and levels of physical, emotional, mental, intellectual and job wellness, 86 questions in total. The results of the study indicate a decreasing tendency for the indicators of physical activity and emotional wellness, and statistically significant differences in the indicators of mental and emotional wellness can be observed depending on the age of students. No statistically significant differences were found depending on the study programme
DETERMINATION OF THE DYNAMIC MODULUS OF LINEAR DEFORMATIONS OF REINFORCED HIGHLY FILLED POLYMER CONCRETE COMPOSITES DURING CURING
The objects of this study are reinforced polymer concrete composites with epoxy matrix and mineral dispersion fillers. Dynamic modulus of linear deformations has been measured according the standardized dynamic testing method ASTM E1876 - 02. The quantitative values of the modulus are obtained by the action of longitudinal and bending. After statistical processing of the obtained results has been established the influence of fiber in the composition on the dynamic characteristic.
RESULTS AND ANALYSIS OF ACHIEVED JOINT RESEARCH AND ACTIVITIES BETWEEN REZEKNE ACADEMY OF TECHNOLOGY AND VASIL LEVSKI NATIONAL MILITARY UNIVERSITY
In 2018, the first group of teachers and students from Vasil Levski National University conducted experiments on laser marking in Rezekne Academy Of Technology, Latvia. Since then, joint research has been increasing every year and better results have been achieved not only in the field of laser technologies, but also in other areas of joint interest. A pilot study group is even being formed in a master\u27s program in laser technology. As a result, the interest in laser technologies and in Latvia at Vasil Levski National University increased significantly. Research has been done on the impact of the exchange between the two institutions on the learners and their motivation to learn
REFORMS IN THE CRIMINAL JUSTICE SYSTEM. LESSONS LEARNED FROM THE REPUBLIC OF LITHUANIA
The paper consists of two parts: one - analysis of obtaining permission to conduct pre-trial investigative action from economic aspects and another on the lessons learned in the Republic of Lithuania during the reforms in the civilian security sector.An essential component of an effective pre-trial investigation is not just investigative actions prescribed by criminal procedure laws, their procedures for conduction during one of the criminal process stages – a pre-trial investigation, qualification of investigators, prosecutors, their skills, secondary law that regulates conduction of investigative actions in details. Also, how does the investigative action work at the preliminary stage of conducting the investigative actions? Is it effective and efficient? For example, in obtaining permission for such actions as a search, covert surveillance, or wiretapping. The author analyses investigative actions from an economic point of view in the first part of this paper. The paper aims to introduce obstacles, misunderstandings, and committed mistakes before launching and during the implementation of the reforms in the Lithuanian criminal justice system after the collapse of the Soviet Union, namely, in the civilian security sector. The author of this paper presents his experience through bullet points named “lessons learned” of being a participant in the above-mentioned reforms. The outcomes of this paper are going to be important in light of the reform in the civilian security sector launched and still going on in Ukraine after the Revolution of Dignity of 2014. It helps to avoid mistakes that were made during reforms in the Republic of Lithuania.