bluuebunny/crossref_metadata_2025 huggingface dataset:
RISK ANALYSIS FOR APPLE ORCHARD SURVEY AND MONITORING USING UAV
Authors: Litavniece Lienīte , Kodors Sergejs , Dekšne Juta , Lācis Gunārs , Zarembo Imants , Pacejs Antons
Published: June 2023

Risk analysis is an integral part of modern business management because successful business largely depends on the effective implementation of risk analysis. Agriculture is an important sector in the national economy, therefore Industry 4.0 increasingly provides digital solutions in orchard management, which facilitate and simplify decision-making in daily tasks. Meanwhile, unmanned aerial vehicles are applied as the agriculture sector's main monitoring and data acquisition tool. However, this means that it is necessary to pay attention to risk analysis due to the process of managing the orchard, where not only a person and the mechanized equipment controlled by him, which moves on the ground but also flying automated equipment participates. The purpose of the article is to perform the risk analysis for the survey and monitoring of orchards for yield estimation using unmanned aerial vehicles by considering commercial apple orchards in Latvia. The main thing is that most risks are predictable, but planning is necessary to reduce the probability of their occurrence.
STUDY OF THE APPLICATION OF PELLETS FROM TEXTILE MATERIAL WASTE AND BIOMASS MIXTURE IN INDUSTRIAL AND RESIDENTAL HEATING SYSTEMS
Authors: Kramens Janis , Vīgants Edgars , Kanukuntla Sai Pavan , Goljandin Dmitri , Glušņova Jeļizaveta
Published: June 2023

The efficient waste management hierarchy is based on four priorities, reuse, recycle, energy recovery, deposit.Efficient energy recovery from non-recyclable textile materials (waste to energy) principles we study in this paper. Energy recovery from the fuel pellets consisting of waste textile materials and biomass depends on many factors. One of the main is to create a competitive form for the newly offered fuel (pellets from a mixture of biomass and textile), as well using a new generation of small-scale energy production facilities. Using already existing applications for efficient waste management is one of the circular economy aspects we lay on in this paper.Roughly estimated that the quantities of textiles separately collected will increased from 65 000 to 90 000 tons per year across the EU-27 from 2025. Reuse and recycling outlets will need to be created, as the current sorting and recycling capacities are not sufficient to process the anticipated volumes. However, it is also expected that at least half of these additional volumes will comprise non-reusable textile waste with specific flame retardant (FR) treatment. It is known that flame retardant is hazard by its adverse environmental impacts of FRs in their production and disposal phases.The objective of the paper is to review opportunities of elaboration a new type of the fuel pellets, and using them in industrial heat pellet boilers and combined heat and power CHP systems.Elaborated the new pellets from biomass (prepared by plasticization method) and chopped textile waste sized till 2-3 mm (by method separative milling) were tested in controlled combustion processes.Experiments were carried out by adding different proportions of textile waste to biomass pellets and the results obtained are summarized in the article
PHYSIOLOGICAL RESPONSE OF SOME WHEAT CULTIVARS TO THERMAL STRESS
Authors: Dunaiska Tatjana , Batjuka Anna , Petjukevičs Aleksandrs , Škute Natalja
Published: June 2023

Plants are exposed during their development to the influence of various stressful factors, both abiotic and biotic in natural conditions of habitation. Thermal stress is likely the most important abiotic factor that adversely affects plant growth and development. Wheat (Triticum aestivum L.) is one of the most economically important crops worldwide. In this study, three Latvian winter wheat cultivars ´Creator´, ´Galerist´, and ´Skagen´ were used as a research model that were subjected to short-term high temperature (42°C, 1 h) and analyzed for the following growth parameters (maximum length of root, length of first leaf and coleoptile as well as seedlings weight). In general, short-term high temperature caused an insignificant reduction in almost all growth criteria like the first leaf growth, coleoptile growth, seedlings weight, and maximal root growth in wheat cultivars ´Skagen´ and ´Galerist´ at the 6th day of development.  Furthermore, almost all growth characteristics were stimulated by short-term high temperature in the wheat cultivar ´Creator´. A slowing of the growth processes under the influence of short-term thermal stress revealed varietal specificity on the impact of this stressor on the morphological structure of cereal, which makes it possible to diagnose the stress tolerance of wheat cultivars.
CHALLENGES OF SSF PROCESS FOR PEA AND WHEAT BRAN VALORIZATION USING TRICHODERMA SPP. FOR BIOCONTROL AGENT PRODUCTION
Authors: Kurpnieks Oskars , Senkovs Māris , Rimkus Alīna
Published: June 2023

Fungal strain Trichoderma spp. is a known bio control agent (BCA), which are difficult to obtain using more prevalent industrial-scale biofermentation methods such as submerged fermentation (SmF) However, difficult up-scalable solid-state fermentation (SSF) are appropriate for such BCA production. An automated semi-rotating drum bioreactor was developed and built to explore SSF scale-up using pea and wheat bran as substrates to valorise food-industry by-products into viable BCA ‘s. Estimation of biomass using CO2/O2 analysis in exhaust gasses revealed that mix of pea and wheat bran can produce a viable BCA ‘s using gentle mixing technique with possibilities of industrial scale-up
ASSESSMENT OF RARE EPIPHYTIC LIVERWORT TRANSPLANTATION METHOD IN POPULUS TREMULA FOREST
Authors: Mežaka Anna , Irbe Inese , Stepanova Dace
Published: June 2023

Epiphytic bryophytes are important biodiversity elements in forest ecosystems globally. In addition, bryophytes take part in ecosystem functioning and are excellent environmental indicators. Almost half of the red-listed bryophyte distribution in Latvia is related to forest habitats. However, despite the increasing knowledge about epiphyte ecology, we are lacking information about individual rare species environmental demands. The present study aimed to evaluate the transplant disc method in rare liverwort transplantation success in aspen forest. As a result, we found that the transplant disc method can be used in epiphytic liverwort studies, but improvements are recommended in sealant selection for transplantation. Liverwort transplants were sensitive to changed substrate quality. Although transplant physiological stress during the transplantation experiment could be important. Epiphyte transplantation studies could help to test epiphyte sensitivity to global climate change in the future.
THEORETICAL AND METHODOLOGICAL ASPECTS FOR THE DEVELOPMENT OF A CREATIVE ECONOMY IN THE CONTEXT OF THE FORMATION OF AN INNOVATIVE BUSINESS ECOSYSTEM
Authors: Arbidane Iluta , Synycyna Halina , Znotina Daina , Ruža Oksana
Published: June 2023

The aim of the study is to analyze the theoretical basis of creative economy and its development trends in the context of innovative business ecosystems formation. The scientific novelty of the research consists in solving the most important scientific and applied problem - further development of theoretical provisions of creative economy, ecosystems, as well as substantiation of the conceptual approach to the formation of innovative business ecosystem as a coherent management model. In the process of research, general scientific and special methods were used: scientific abstraction, deduction, analysis and synthesis, system and critical analysis, structural-logical, ascending from the abstract to the concrete, and statistical analysis. It has been substantiated that the priority development of creative economy as a strategic driver of sustainable development is the formation of an ecosystem conducive to the development of complex non-linear dynamic innovation processes, development of value propositions and value chain. The analysis of theoretical and methodological aspects of formation and functioning of ecosystems indicates the lack of development of this problem and the need to develop scientific approaches to their identification. Generalization of the results of theoretical analysis allowed us to group ecosystems according to the identified attributes into five main types. It was substantiated that a sustainable business ecosystem is a favorable environment for innovation to increase its value and contribute to the achievement of sustainable development goals. It is proposed to consider a sustainable "business ecosystem" as a coherent management model with established characteristics, which describes an aggregate system of business ecosystem modules that interact with each other and are focused on co-creation and co-production of value.
APPLICATION OF THE FINITE ELEMENT METHOD FOR THE DESIGN OF SMALL ARM BARRELS
Authors: Conev Conyu , Karadzhov Tsanko
Published: June 2023

The article presents an experimental investigation of the possibility for using the finite elements method (FEM) for definite the frequency of cross vibrations to the barrel of the small arm. To achieve the goals of the investigation a model of a real barrel with software product based on the method of the final elements is created. An experimental investigation with real shooting is done and statistics hypothesis checking is executed.
ACCUMULATED LABORATORY DATA IN B12 VITAMIN BLOOD LEVEL TIME DEPENDENCY STUDIES IN PATIENTS WITH MYELOMA, LYMPHOCYTIC LEUKEMIA AND MYELOBLASTIC LEUKEMIA IN LATVIA
Authors: Gavars Didzis , Auce Agris , Tauckels Ēriks , Miķelsone Agnese , Tutane Anna Inese
Published: June 2023

Vitamin B12 blood level in patients with myeloma (C90 - International Classification of Diseases (ICD-10)), lymphocytic leukemia (C91) and myeloblastic leukemia (C92) prior and after the diagnosis and also BCR-ABL (fusion gene from breakpoint cluster region BCR gene and tyrosine-protein kinase ABL1 (Abelson murine leukemia) gene) tests for C92 patients were studied.Clinical records of 20 C92 patients in Riga East University Hospital were complemented with 6987 B12 clinical test data accumulated in E Gulbis laboratory (EGL) for 7451 patients over 20 years period. BCR-ABL and B12 dynamics for 11 patients with sufficient number of BCRABL and B12 tests were studied.Oracle Cloud with pseudonymized data replica from more than 350 000 000 original EGL clinical test data was used. The data were selected by online analytical processing and SQL built in tools and then used in offline analysis and visualization.Annually there are 107, 189 and 91 confirmed cases of C90, C91 and C92 in Latvia. EGL has 30% more C90-92 patients, due to suspected but later unconfirmed cases. Out of 7451 patients 1386 had one B12 test, two- 548, three and more- 864. The patients with diagnosis fluctuating between C90, C91 and C92 were excluded from the study. The data for the time period of 10 years before and after the first diagnosis were analyzed.Results. Methods and tools for data extraction and analysis from large amount of archived clinical test data were developed and applied. High and very high B12 level was observed for 53% of C92 patients starting from 3 years prior to diagnosis. For C90 and C91 patients B12 level changes around the diagnosis date were also observed although the effect was considerably smaller. Analysis of 11 selected patient data with clinical records showed timewise correlation between B12 and BCR-ABL for 3 of the patients.
THE HEAT TRANSFER AND MAGNETOHYDRODYNAMICS PROBLEM WITH HEAT SOURCE IN HALF INFINITE 1-D DOMAIN
Authors: Kalis Harijs , Kangro Ilmārs
Published: June 2023

In this paper we consider the temperature and laminar flow of an incompressible conducting fluid past a non-conducting half-space. For the space approximation the finite differences method-finite difference scheme (FDS) and finite difference scheme with exact spectrum (FDSES) for solving the heat transfer and laminar flow initial boundary-value problem are used. This procedure allows reducing the problem to initial value problem for ordinary differential equations and the solution to the problem can be obtained numerically and analytically. The equation of the temperature is un-depending on the velocity and this function we can obtain in analytical form use the integral transform methods- Fourier and Laplace transforms.
MULTIPLE PATH PARTICLE DOSIMETRY MODEL CONCEPT AND ITS APPLICATION TO DETERMINE RESPIRATORY TRACT HAZARDS IN THE 3D PRINTING
Authors: Borisova Anna , Rudus Karīna , Pavlovska Ilona , Martinsone Žanna , Mārtiņsone Inese
Published: June 2023

The Multiple Path Particle Dosimetry (MPPD) model is computer software that estimates and visualizes the deposition, clearance, and retention of particles in the respiratory tract systems of humans, rats, and other species. The mathematical model provides a broad spectrum of settings and input options. This research aims to explore the MPPD model concept and determine the deposition fraction (DF), clearance, and retained mass in the human respiratory tract (HRT) based on the geometric mean diameter (GMD) and mass concentration (MC) of particulate matter (PM) emitted during the 3D printing process. We used the real-time air sample data collected during the 8-hour working shift in the 3D printing office. Ultrafine PM deposits mainly in lungs (56%), fine PM mostly deposits in the upper respiratory tract (URT) (41%) and lungs (39%), but coarse PM mostly deposits in the URT (81%). The biggest DF in lower respiratory tract is ultrafine PM (487 μg), the smaller DF is coarse PM (185 μg) and the smallest DF is fine PM (123 μg). The biggest DF in lung for all PM - lower lobes (fine PM - 60%, ultrafine PM, coarse PM - 61%). In a model, where exposure was 5 hours a day, five days a week, during one month, followed by one year of post-exposure period, it was shown that retained mass in the tracheobronchial (TB) region was 1% for ultrafine and coarse PM each, 2% for fine PM, and 55% for all PM in the pulmonary region. The MPPD software is an easily accessible and valuable tool for assessing the impact of PM on the HRT. Particulate matter decreasing in diameter, tend to deposit mostly in the deeper levels of HRT. Tracheobronchial region clearance is more rapid than pulmonary region clearance. Potentially for persons using the 3D-printer regularly the worst health impact could be associated with smaller size of PM, due to tendency deposit mostly in pulmonary region where the clearance rate is slower.
DIGSM 4.0 CURRICULUM LIFECYCLE BASED ON COMPONENT ORGANISED LEARNING METHOD
Authors: Shevtshenko Eduard , Maas Rene , Karaulova Tatjana , Dembovska Iveta , Truver Anna
Published: June 2023

The research under consideration is how to build COL (Component Organised Learning) based curriculum lifecycle that teachers can apply in different fields. The problem is that the degree studies curriculum is not always applied to working students as the needs of the companies they work for differ. Companies find it more valuable when students can use the existing curriculum topics to solve today's company problems. Current degree studies take considerable time and are unsuitable for full-time employed specialists. The proposed Education 4.0 concept brings the knowledge and skills required by the market for full-time employed students in a time-efficient way. One possible solution to apply this concept in practice is to create a micro-credential curriculum for companies. The authors suggest using the intensive week approach for analysis, where the students will solve the real company problem using previously studied solutions. They will also use the Moodle courses linked to the developed COL to speed up access to the materials. Authors suggest organising such an event in collaboration with consortium partners and involving all teaching staff who worked on course development. After introducing problems brought by the company and visiting the company on site, asking the questions, students define the task to be solved in groups. After that, the Authors recommend providing intensive courses where each partner will present the developed Moodle materials. The target is that the students will solve the problem in 24h and present solutions to the company representative.
INVASION OF INFORMATION SYSTEMS AS A DANGER FOR HUMAN RIGHTS
Authors: Bērziņš Ansis Ataols
Published: June 2023

In recent years, more and more people have been pushed to direct usage of various information systems (IS) developed by governmental, commercial, municipal, and non-governmental organisations. IS were widely used already for a relatively long time – 2 or 3 decades (depending of state), however, people were not pushed to use them directly, they were used by staff members of organisations, so for clients it does not made a difference, do they use an IS or, for example, a paper folder or a file cabinet. Now people are increasingly required to use ISs directly, which makes the process more challenging and potentially dangerous. This article aims to analyse this situation and these processes, trying to classify risks, draw conclusions and provide recommendations.
RESEARCH ON WORKING BODIES OF HAMMER CRUSHERS EMPLOYING THE FINITE ELEMENT METHOD
Authors: Devin Vladlen , Yermakov Serhii , Gorbovy Oleg , Pidlisnyj Vitaliy , Semenov Oleksandr
Published: June 2023

The present paper studies the issues of improving the reliability of the working bodies of hammer crushers. This machine is widely used for grinding grain material in animal husbandry and the processing industry. The main wear element of such crushers is the hammers and disks to which they are attached. To study the strength characteristics of these parts, a technique and algorithm for studying the stress-strain state of the hammer crusher disc employing the finite element method (FEM) using computer simulation software products were developed. The mathematical apparatus of finite element method simplifies the model construction where the stress-strain state must be explored. Finite element method provides solutions in the form of stress and deformation fields in almost any cross-section of structural parts. The express analysis module of the APM FEM COMPASS system was used as the software for this work. The implementation of finite element methodwill reduce the metal intensity of the equipment, increase the reliability of its operation and reduce the cost, improve the quality of the feed produced. The results of the study showed that the maximum stresses occur on the surface creating the internal holes in the place of attachment of the disc to the shaft, but the stresses that occur there remain within the normal range.
STUDY OF THE UNLOADING AND SELECTION PROCESS OF ENERGY WILLOW CUTTINGS FOR THE CREATION A PLANTING MACHINE
Authors: Yermakov Serhii , Hutsol Taras , Gerasymchuk Igor , Fedirko Pavlo , Dubik Viktor
Published: June 2023

The article highlights the problems of ensuring continuous unloading of energy willow cuttings from slotted bunkers.  During the free discharge of rod-like bodies, such phenomena as crypt formations, distortions, pinching occur, which stop the discharge under the action of gravity.  Finding such parameters, under which the system will work evenly and without stops, will make it possible to automate many processes related to working with such material, in particular, when developing a piecemeal selection mechanism for a planting machine.  The study revealed and analyzed the possible forms of vaults that are formed during unloading from creating obstacles to movement.  As a hopper model, for unloading cuttings, a slotted hopper in the form of two walls located at angles to the horizontal plane is considered.  These walls form an unloading slot with adjustable width of the unloading window and an adjustable tilt angle.  During the study, vaults were recorded, which are formed at different parameters of the bunker during free unloading.  As research has shown, in order to ensure uninterrupted unloading of cuttings, there is such a width of the unloading window of the hopper, which will ensure uniform pouring of cuttings without crypt formations and stops associated with this process.  The analysis of continuous discharge of rod-like material established that for cuttings of energy willow, the width of the window, which ensures continuous discharge, is 8-12 cm.
THERMAL CHARACTERISTICS OF MATERIALS IN MODELLING OF WELDING PROCESSES
Authors: Anguelov Valentin
Published: June 2023

The application of welding processes during manufacturing of metallic products result in changes of the properties of the base materials. Process simulation enables evaluation of the effect of heat application in proximity to the weld seam. The availability and use of input data, relevant for the specific material, is essential for the reliability of the results. The thermal characteristics of the materials, required for the heat modelling were identified. Their dependency on the material temperature was investigated and the formulas were presented. Particular values were found in existingdata sources, for specific structural steels, stainless steels, nickel and titanium alloys. The values of the thermal characteristics were represented and in graphical and tabulated formats, facilitating direct implementation in calculations, assessment of variation trends and applicability for specific purposes.
PRACTICE ORIENTED HEAT SOURCE MODEL CALIBRATION
Authors: Tongov Manahil , Anguelov Valentin
Published: June 2023

The modelling of the thermal process is used as a tool in determination of the properties of the materials, subject to welding. One of the most important steps in the modelling is the calibration of the heat source model. This is a necessary condition for a given model to be used to solve practical problems. The standard practice in this regard is to calibrate the model by the shape of the melted zone or by the temperature cycles at set points. In the present work, the heat source model calibration based on the maximum temperatures measured at several surface points, at different distances from the seam line, is considered. The temperature cycles in the welded joint and the penetration depth were assumed by the model, calibrated in such non-destructive way. The calculated temperature cycles were compared with records of the temperature during welding. The actual penetration depth was measured by metallographic examination of samples and compared with the assumed penetration depth. The obtained results make it possible to evaluate the suitability of the proposed methodology for determining the cooling rate in the heat affected zone.
INVESTIGATING THE CONTRAST OF SURFACE MARKING ON DIFFERENT COLOR CONNECTORS FOR TELECOMMUNICATIONS NEEDS
Authors: Raubiška Daniels , Adijāns Imants , Yankov Emil , Lazov Lyubomir
Published: June 2023

The development of marking technologies for telecommunications connectors requires increasingly detailed information about their applications. One solution is to use QR codes that contain sufficient information about the connectors' applications. Accurate marking of connectors requires a precise marking system, such as a laser marking system. In this study, a Rofin PowerLine F20 Varia fiber laser was used to mark four different types of ABS plastic connectors in various colors. To achieve optimal marking for all four colors, three experiments were conducted to achieve contrasting marking and high roughness. Easy QR code reading was achieved with an average marking power of 3 W to 4.2 W, a laser marking speed of 300 mm/s to 500 mm/s, and a scanning frequency of 50 kHz to 70 kHz at a constant pulse duration of 8 ns and raster spacing of 50 µm. The microstructural changes and change in roughness were determined using a laser scanning microscope (Olympus OLS5000), which revealed structural changes on the surface and an increase in relative roughness from 39% to 76%. This experiment shows that different parameters of the laser marking mode are required for each color.
FREQUENCY ANALYSIS OF AN ARM OF MACPHERSON SUSPENSION ON A PASSENGER CAR
Authors: Taneva Stiliyana , Ambarev Krasimir , Penchev Stanimir , Atanasov Hristo
Published: June 2023

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.
ADAPTIVE IMAGE ENHANCEMENT MODEL FOR THE ROBOT VISION SYSTEM
Authors: Smelyakov Kyrylo , Chupryna Anastasiya , Sandrkin Denys , Savulioniene Loreta , Sakalys Paulius
Published: June 2023

Robotics is one of the important trends in the current development of science and technology. Most modern robots and drones have their own vision system, including a video camera, which they use to take digital photos and video streams. These data are used to analyze the situation in the robot's camera field of view, as well as to determine a real-time robot's behavior algorithm. In this regard, the novelty of the paper is special polynomial mathematical model and method for adaptive gradational correction of a digital image. The proposed model and method make it possible to independently adjust to brightness scales and image formats and optimally perform gradational image correction in various lighting conditions. Thus, ensuring the efficiency of the entire subsequent cycle of image analysis in the robot's vision system. In addition, the paper presents the results of numerous experiments of such gradational correction for images of various classes, as well as conditions of reduced and increased levels of illumination of the field of view objects. Conclusions and recommendations are given regarding the practical application of the proposed model and method.
EXPERIMENTAL STUDY OF TOXIC COMPONENTS IN THE EXHAUST GASES DURING THE OPERATION OF A CAR ENGINE WITH GASOLINE AND LPG
Authors: Ambarev Krasimir , Nikolov Valyo
Published: June 2023

The article presents and analyzes the results obtained from an experimental study of the content of toxic components in the exhaust gases during the operation of a car engine with gasoline and liquefied petroleum gas (LPG). The study was conducted in laboratory conditions by loading the driving wheels with a roller-type chassis dynamometer, corresponding to the established movement of the car with constant speed on a horizontal road section.
COLOR MARKING OF STAINLESS STEEL AND TITANIUM WITH THE LASER OXIDATION METHOD
Authors: Tsvyatkov Petar , Yankov Emil , Lazov Lyubomir , Teirumnieks Edmunds , Teirumnieka Erika
Published: June 2023

Marking of metal products is essential in many industrial processes. It is mandatory for the finished products according to regulations of the European and world legislation. Traditional marking usually creates contrasting symbols that can easily be erased and forged.In recent years, a new method for product identification has appeared - color marking. One of the advantages of this method is that it is difficult to counterfeit. This article aims to present the progress of color marking technology on two types of materials. Three groups of factors have been analyzed: the laser source; the technological process; material properties. Their role in obtaining a specific color marking on Ti and AISI 304 is shown. The results are presented in tables. Each color can be repeated only with strict observance of the three groups of factors.
The 12 July 1993 Hokkaido-Nansei-Oki, Japan, earthquake: Effects of source complexity on surface-wave radiation
Authors: Kuge Keiko , Zhang Jiajun , Kikuchi Masayuki
Published: June 2023

We present an analysis of the data dependency of surface-wave inversions for source parameters of the 12 July 1993 Hokkaido-Nansei-Oki, Japan, earthquake. This dependency is demonstrated by differences between source mechanisms obtained from different data sets, particularly from Rayleigh waves or Love waves, although inversions of various data sets yield unanimously thrust-fault mechanisms. For the inversion of Rayleigh waves, the mechanism is characterized by a shallow-dipping west-plunging nodal plane, which is consistent with P-wave first-motion data and the distribution of aftershocks close to the hypocenter. However, for the inversion of both Rayleigh and Love waves, the mechanism is characterized by a shallow-dipping east-plunging nodal plane. Several numerical experiments were carried out to test a hypothesis that the data dependency is attributed to the effects of source complexity on the surface-wave radiation, with the source complexity being characterized by tempo-spatial changes in focal mechanism and moment release during the rupture process. The experiments show that source parameters obtained from inversions of surface waves with periods as long as a few hundred seconds can be largely affected by using various models of source complexity proposed previously for the Hokkaido earthquake, and the effects on Love waves tend to be systematically different from those on Rayleigh waves. Our preferred source model is characterized by significant tempo-spatial changes in focal mechanism. The experiments based on this model provide a good explanation for the data dependency, although our analysis cannot completely reject the alternative explanation that attributes the dependency to the manifestation of errors in modeling the surface-wave propagation and/or inversion instability. The model is consistent with the data of body waves and long-period surface waves for a very broad frequency band, implying the existence of weak zones with various fault geometries along the eastern margin of the Japan Sea.
Site response for urban Los Angeles using aftershocks of the Northridge earthquake
Authors: Hartzell Stephen , Leeds Alena , Frankel Arthur , Michael John
Published: June 2023

Ground-motion records from aftershocks of the 1994 Northridge earthquake are used to estimate site response in the urban Los Angeles area. Over 1300 shear-wave records from 61 sources and 90 sites are used in a linear inversion for source and site-response spectra. The methodology makes no assumptions about the shape of the source spectrum. To obtain a stable unique inverse, a Q model and geometrical spreading factor are assumed. In addition, the site response at a hard-rock site is constrained to be approximately 1.0 with a kappa of 0.02. The site-response spectra compare favorably with the results of previous and on-going investigations in Los Angeles. A couple of first-order effects are lower site response in the surrounding mountains, dominated by Mesozoic and Tertiary rocks, and higher values in the San Fernando and Los Angeles Basins, containing surficial Pleistocene and Holocene alluvial deposits. Results show good correlation of high site-response spectral values with localized areas of severe damage (Interstate 10 collapse, Sherman Oaks, Northridge, Interstate 5/14 collapse). However, widespread trends in site response across the sedimentary basins are not obvious. The data suggest that site responses are lower near the southern margin of the San Fernando Valley for sources to the north, due to north-dipping sedimentary structures. But the general pattern of site response is characterized by high variability on length scales less than a kilometer. Variations of a factor of 2 in site response are observed over the length scale of 200 m and for the same surficial geologic unit. For some of the alluvial basin sites, surface-wave generation is a significant contributor to elevated site response at lower frequencies, below 2 Hz. The total damage pattern for the Northridge earthquake is influenced by strong source directivity to the north and strong local site effects. The correlation of weak-motion site-response estimates with areas of significant damage demonstrates the value of these field measurements in future urban planning and in the reduction of seismic risk in urban areas.
Incidents of ground failure from the 1994 Northridge earthquake
Authors: Stewart Jonathan P. , Seed Raymond B. , Bray Jonathan D.
Published: June 2023

Numerous incidents of ground failure from the 1994 Northridge earthquake caused thousands of pipe breaks and damaged many structures. In this article, significant occurrences of ground failure in the San Fernando Valley, Simi Valley, Santa Clara River area, central Los Angeles, and a number of coastal areas are described, and the likely culprit mechanisms are identified. Ground failure in many areas could be readily associated with liquefaction and/or seismically induced compaction of young alluvial soils or fill materials previously known to have a high ground failure susceptibility. However, ground failure also occurred in areas not previously thought to be susceptible to such hazards. Taken together, these incidents provide insight into a variety of ground failure phenomena that can affect urban areas during earthquakes.
A Study on Guidelines and Plans for Activating of Clinical Ethics Consultation in Catholic health care Institutions
Authors:   Research Institute For Life And Culture Sogang University, Kim Mi Seon , Park Eun Ho
Published: June 2023

In the pluralistic society where the medical technology is highly advanced, the role of clinical ethics consultation that helps to solve the ethical conflicts in health care is getting important. Clinical ethics consultation is an activity to support informed, deliberative decision making on the part of patients, families, and the health care team in the patient care. In Korea, clinical ethics consultation was regulated as an activity of the institutional ethics committee with the enforcement of the 「Act on Hospice and Palliative Care and Decisions on Life-sustaining Treatment for Patients at the End of Life」 in 2018, However, most health care institutions in Korea do not provide clinical ethics consultation, and this situation is the same even for Catholic health care institutions, which account for 8 percent of health care in Korea. In particular, Catholic health care institutions should be able to provide effective ethical consultation with specific ethical guidelines and activation plans that are consistent with Catholic spirituality, even in the midst of rapid medical development and social/institutional changes. Therefore, it is judged appropriate to apply the 『Ethics and Religious Directive for catholic Health Care Service : ERDs』 published by United Conference of Catholic Bishops as an appropriate model for the corresponding ethical guidelines. In addition, the specific case of the Catholic Medical Center, which is making progress in activating clinical ethics consultation, can suggest a direction for the activation of clinical ethics consultation in other Catholic healthcare institutions and can be a exemple worth sharing with all medical institutions pursuing holistic health care. If clinical ethics advice is activated and properly operated in Catholic health care institutions, it will become the conscience of the institution communicating to realize the best interests of patients, and high quality health care services will be achieved by protecting the rights and conscience of medical staff. This will be of great help in protecting the identity of a Catholic health care institution serving human dignity and value in the increasingly industrialized medical field.
A Study on Practitioners' Perceptions of the Implementation Process and Performance of the Community Care for People with Mental Disorders
Authors:   Research Institute For Life And Culture Sogang University, Hong Seon Mee
Published: June 2023

Through focus group interviews, this study explores perceptions of practitioners participating in the community care for people with mental illnesses and analyzes the operation process and performance of the community care. The main contents are ① evaluation of the overall circumstances that have changed while promoting the community care project, ② public participation and its role in the service delivery process, ③ collaboration with various service delivery entities, ④ expansion of regional social network for providing multi-field services, and ⑤ changes in awareness of people with mental disabilities and mental health through the community care. In terms of changes in users, the major keywords include expansion of community services and user-centered service provision method. In regards to changes in the service delivery system, the major keywords are ① securing access to regional services, ② changes in service provision methods based on linkage and cooperation, and ③ general changes in community service provision and community perceptions of care. The results of the analysis serve as evidence in evaluating the changes in the service users and the service delivery system, and identifying the performance and limitations of the community care project for people with mental illnesses. This study provides basic knowledge necessary to develop a community-centered mental health service system and service delivery method in the future. This study will contribute to the establishment and expansion of a community-centered mental health service model that supports the mentally disabled to return to the community and normalized life.
Requirements for an Online Automated Project Allocation System in Higher Education Institutions – A Case Study
Authors: Khurwolah Mooneerah , Chuttur Mohammad Yasser
Published: June 2023

This paper presents the requirements gathered for an online automated project allocation system that can be used to assign final year projects to students registered in Higher Education Institutions (HEIs). The requirements are gathered for a well-known University in Mauritius. This research is motivated by several issues encountered with the current manual system in place at the studied institution and the need for adopting online systems following the COVID-19 outbreak. Following document analysis and a survey, important functional and non-functional requirements for an online automated project allocation system were uncovered. Gathered requirements also helped in determining a recommended workflow that can be adopted as best practice for final year project allocation. We posit that requirements presented in this paper can help develop a system that can be very useful and ultimately streamline the process for allocating projects typically important for Higher Education Institutions and other similar training institutions.
Élite, orden y conflicto. Sobre cómo se construyó un orden social en Cali 1910-1953
Authors:   Universidad Icesi, Sáenz José Darío
Published: June 2023

El libro da cuenta de la manera en que se forma una robusta red de élite de poder conformada por personas de los sectores dominantes de Cali durante el periodo 1910-1953. Una red con tupidos vínculos políticos, económicos, cívicos y culturales, en cuyo seno se hallaban alojados personas y familias con larga tradición de poder local y regional. Se establece el papel desempeñado por esta red en la configuración del orden social de dominación en la ciudad, y cómo logran construirlo mediante la creación de patrones cognitivos y simbólicos, instituciones reguladoras, definiciones espaciales, disciplina y control policial. Estas dinámicas de ordenamiento social se concretaban, para cada momento histórico, con decisiones fundadas en política moral, procesos de estatización de conductas en el ámbito público, y formas de inclusión diferenciada con los sectores populares. Este proceso construía ideas y símbolos que guiaban la cotidianidad pública, formas de regulación de las conductas callejeras, clasificaciones espaciales para distribuir grupos, prácticas y acciones mediadas por las fuerzas coactivas para disciplinar en el marco del pensamiento oficial. Se presentan las dinámicas de grupos sociales que mediante acciones colectivas contenciosas desafiaron el orden social de dominación múltiple planteado por la red de élite de poder local.
Features of echocardiographic examination in patients with COVID-19
Authors: Golukhova E. Z. , Slivneva I. V. , Mamalyga M. L. , Alekhin M. N.
Published: June 2023

Novel coronavirus infection has become one of urgent health problems of the 21st century. The associated disorders often result in the development of cardiopulmonary pathology, which requires creation of a new paradigm in diagnosis and treatment. Studies performed during the pandemic have demonstrated an important role of echocardiography (EchoCG) in diagnosis of right ventricular (RV) dysfunction in patients with respiratory insufficiency in COVID-19. The analysis of EchoCG parameters with a high prognostic value showed that in EchoCG, a special attention should be paid to right heart dimensions, RV contractility, and pulmonary artery (PA) systolic pressure, which are the most sensitive indexes of RV afterload and indirect markers of pulmonary disease severity. RV FAC can be recommended for evaluation of the RV systolic function as the most informative variable. Also, it was demonstrated that the RV longitudinal strain has an additional significance for early identification of signs of systolic dysfunction and risk stratification in patients with COVID-19. In addition to the effectiveness and reproducibility of this method, an important advantage of EchoCG is its availability, possibility of saving images for remote interpretation by other specialists, and tracking changes in morphological and functional parameters of the heart. Thus, the analysis of international literature suggests that EchoCG plays an important role in prediction of severe cardiopulmonary disorders and timely selection of the treatment for patients with COVID-19. For these reasons, EchoCG should serve as an additional method of clinical evaluation, particularly in persons with moderate or severe disease.
The Efficacy of the Smart-Rehabilitation Program in Patients After the Correction of Valvular Heart Diseases
Authors: Rozhnev V. V. , Gorbunova E. V. , Sadovnikov A. V. , Lyapina I. N. , Barbarash O. L.
Published: June 2023

Aim      Comparative analysis of the effectiveness of a new approach, "SMART rehabilitation of patients after heart valve replacement", which includes, in addition to face-to-face training, Internet technologies in the form of video conferencing, the mobile application "Calculation of the warfarin dose", and a traditional program for educating patients after correction of valvular defects.

Material and methods  The study included 190 patients with prosthetic heart valves. The main group consisted of 98 patients who completed a distance learning course. The control group included 92 patients participating in face-to-face training. Clinical and instrumental examinations (electrocardiography, echocardiography, determination of international normalized ratio (INR)), and surveys to evaluate awareness, compliance with treatment, and quality of life (QoL) were performed.

Results At baseline, the awareness, compliance and QoL did not differ between the compared groups. After 6-month follow-up, the mean score of awareness increased by 53.6 % (р=0.0001). The compliance with treatment increased 3.3 times in the main group and 1.7 times in the control group (p=0.0247). Patients of the main group were more prone to self-management (p=0.0001), had better medical and social awareness (p=0.0335), medical and social communicability (p=0.0392), confidence in the therapeutic strategy of the attending physician (p=0.0001), and treatment effectiveness (p=0.0057). Analysis of QoL showed increases in living activity 2.1 times (р=0.0001), social functioning 1.6 times (р=0.0001), and mental health 1.9 times (р=0.0001).

Conclusion      The novel approach of distance learning, "SMART rehabilitation of patients after heart valve replacement", provides improvements in awareness, compliance with treatment and QoL.
Possible predictors of stroke in patients with atrial microfibrillation
Authors: Aydın Cihan
Published: June 2023

Background    Very short-lasting episodes of AF-like activity (micro-AF) may be precursors of undiagnosed silent episodes of atrial fibrillation. In this study, we examined the relationship between increased left atrial sphericity index (LASI) and stroke in patients with micro-AF.Material and Methods    A total of 100 consecutive patients with micro-AF enrolled in this study. The histories, cranial magnetic resonance, and computed tomography images of these patients were scanned from the hospital database. The patients were divided into two groups according to whether or not they had a stroke. LASI was calculated as a fraction of the left atrial maximum volume to the left atrial volume of the sphere in a 4‑chamber view. Atrial electromechanical delay (AEMD) intervals were calculated from the atrial wall and atrioventricular valve annulus levels by using tissue Doppler imaging (TDI). These two groups were compared in terms of stroke predictors.Results    A history of stroke was present in 25 (25 %) patients diagnosed with micro-AF (Group 1). 75 patients did not have stroke (Group 2). There was a significant difference between the two groups in terms of left atrial lateral wall electromechanical delay (LA lateral AEMD) times, left atrial volume index (LAVI), and left atrial sphericity index (LASI). Findings: LAVI, 40.9±3.72 vs. 29.9±3.84, p<0.001; LASI, 0.84±0.07 vs. 0.66±0.07, p<0.001; LA lateral AEMD, 77.2±4.85 vs. 66.5±3.66, p<0.001.Conclusions    Stroke precautions should be taken in patients with micro-AF. New predictive indexes should be given importance. Changes in LASI, LAVI and LA lateral AEMD values may be a predictor of stroke in patients with micro AF.
Evaluation of the operator learning curve for radiofrequency ablation for atrioventricular nodal reentrant tachycardia
Authors: Küp Ayhan , Celik Mehmet , Kepez Alper , Demir Serdar , Gulsen Kamil , Ozgeyik Mehmet , Kanar Batur Gonenc , Karagoz Ali , Yildirim Cagan , Tanircan Muhammmed Rasit , Akgun Taylan , Uslu Abdulkadir
Published: June 2023

Aim    The aim of this study was to determine the average minimum number of slow pathway ablation procedures required to reach a steady success rate among inexperienced operators.Material and Methods    We analyzed the consecutive AVNRT ablation procedures of three inexperienced operators for the rate of operational success and complications.Results    Operators performed a total of 156 AVNRT ablation procedures. There was no statistical significance between the three operators regarding the rate of success (p=0.69) and complications. There were significant differences between the operators in terms of procedure time, fluoroscopy time, and cumulative air kerma. The variability of procedure time and cumulative air kerma, both among three operators and within each operator, decreased significantly after the 25th case. Each operator was analyzed individually for the probability of success as related to the cumulative number of ablations. All trainee operators reached a success rate of 90 % at the 27th procedure.Conclusion    An average of 27 slow pathway ablation procedures should be performed by a beginner operator to achieve proficiency.