bluuebunny/crossref_metadata_2025 huggingface dataset:
Prototype Set Praktikum Wireless Power Transfer (WPT) dengan teknik Magnetik Resonant Coupling
Authors: Heriansyah Heriansyah
Published: July 2022

Pemanfaatan teknologi Wireless Power Transfer (WPT) memiliki potensi yang besar di dalam kehidupan. Ada 6 teknik WPT, salah satunya magnetic resonant coupling. Teknik ini memiliki prinsip interaksi inductive coupling dan resonance pada kumparan. Prinsip kerja teknik tersebut adalah adanya pengaruh induksi magnetik pada dua kumparan yang memiliki frekuensi resonansi yang sama sehingga dapat mentransmisikan energi dari kumparan satu ke lainnya secara efisien. Rangakaian yang digunakan dalam WPT adalah rangkaian RLC seri dengan koil berupa circular flat spiral. Nilai induktansi diri dari 3 koil yang digunakan masing-masing 20 µH, 130 µH, dan 230 µH. Efisiens daya pada WPT meningkat dengan meningkatnya induktansi diri koil. Frekuensi resonansi untuk tiap koil masing masing berada pada rentang 70-80 kHz untuk koil dengan induktansi 20 µH, 30 kHz untuk koil dengan induktansi 130 µH, dan sekitar 20 kHz untuk koil dengan dengan induktansi 230 µH
Uji Alat Kekeruhan Air Menggunakan Turbidity Sensor Berbasis Arduino
Authors: Rahman Refpo
Published: July 2022

Alat uji kekeruhan air dirancang dengan menggunakan turbidity sensor berbasis Arduino Uno untuk mengukur tingkat kekeruhan air. Pengujian alat dilakukan dengan dua tahap. Tahap pertama, pengujian dalam rangka kalibrasi menggunakan lima sampel yang disimbolkan dengan sampel A-E. Sampel ini diukur untuk mendapatkan luaran tegangan dari alat rancangan dan tingkat kekeruhan air (NTU) dari alat standar. Hasilnya sampel A diperoleh 4,17 V dan 3,014 NTU, sampel B 4,066 V dan 43,02 NTU, sampel C 3,864 V dan 225 NTU, sampel D 3,798 V dan 312 NTU, sampel E 2,49 V dan 3000 NTU. Nilai pengukuran ini digunakan untuk kalibrasi alat rancangan. Tahap kedua, alat yang sudah terkalibrasi dilakukan pengujian ulang dengan data luaran NTU. Data pengukuran ini digunakan untuk menghitung kesalahan relatif dengan membandingkan data yang diperoleh dari alat standar. Hasilnya diperoleh bahwa tingkat error paling kecil saat pengukuran sampel > 220 NTU dengan tingkat error dibawah 10 %. Sedangkan, tingkat error terbesar saat pengukuran kekeruhan air < 220 NTU dengan tingkat error diatas 10% hingga mencapai 100%.

Kata Kunci: Arduino Uno, Turbidity Sensor, Alat kekeruhan air
Pendulum Experiments Using A Smartphone-Based Phyphox: An Application of Basic Physics Experiment Course During Covid-19
Authors: Pebralia Jesi -
Published: July 2022

Selama masa lockdown dan PSBB Covid-19, aktivitas mahasiswa secara tatap muka di kelas ditiadakan baik kegiatan yang berupa kuliah teori di kelas maupun praktikum di laboratorium. Semua kegiatan belajar dan mengajar dilakukan secara daring menggunakan Learning Management System (LMS) yang diterapkan pada masing-masing sekolah dan perguruan tinggi. Kegiatan praktikum yang dilakukan secara online dan jarak jauh mengharuskan pendidik untuk mencari metode yang tepat agar tujuan pembelajaran dapat tercapai dengan baik sebagaimana pembelajaran konvensional. Tujuan dari penelitian ini yaitu memberikan gambaran salah satu bentuk praktikum fisika dasar yang dapat digunakan pada pembelajaran jarak jauh khususnya pada masa pandemi Covid-19. Adapun topik yang dipilih yaitu gerak pendulum dengan menggunakan smartphone berbasis aplikasi Phyphox. Hasil penelitian yang diperoleh menunjukkan kesesuaian grafik data yang dihasilkan dari praktikum menggunakan smartphone dan perhitungan secara teori dengan nilai R square sebesar 0,998. Sehingga smartphone dapat digunakan sebagai alat bantu praktikum fisika dasar pada pembelajaran jarak jauh.

 

Kata Kunci: covid-19, Phyphox, pembelajaran jarak jauh, pendulum, praktikum fisika
Rancang Bangun Wastafel Otomatis Dengan Menggunakan Sensor Fotodioda
Authors: Fauza Naila
Published: July 2022

Covid-19 adalah virus yang menyebabkan infeksi saluran pernapasan ringan dan berbahaya. Untuk memprediksi penyebaran dan peningkatan jumlah orang yang terinfeksi, masyarakat disarankan untuk menerapkan pola hidup sehat dan mencuci tangan. Saat ini, kran yang digunakan terutama di sistem wastafel adalah kran manual. Untuk membuka atau menutup kran, pengguna harus menyentuh kran secara langsung. Maka diperlukan sebuah inovasi pada system wastafel ini. Inovasi yang dilakukan berupa kran otomatis dengan sensor Fotodioda dimana dengan penggunaan sensor ini nantinya dapat membantu kegiatan mencuci tangan agar lebih mudah dan lebih praktis. Dengan cara menempatkan tangan pada posisi tertentu, air dan sabun cair akan keluar secara otomatis. Metode yang digunakan adalah metode eksperimen. Prosedur penelitian ini meliputi perancangan, perakitan, dan pengujian alat. Hasil percobaan yang dilakukan menunjukkan bahwa saat tangan mengakses sensor di wastafel, air wastafel otomatis keluar, dan saat tangan dilepas tidak ada air yang keluar, hal ini menunjukkan bahwa seseorang tidak perlu lagi memutar kran air untuk menghidupkan Air tersebut.
Pemodelan ke Depan dan Inversi 2D Anomali Medan Magnet Berdasarkan Bentuk Prisma Sederhana
Authors: Setyawati Yulia Ayu , Supriyadi Supriyadi , Priyantari Nurul
Published: July 2022

Metode magnetik berfungsi untuk mengetahui struktur bawah permukaan berdasarkan variasi medan magnetik di permukaan bumi. interpretasi struktur bawah permukaan berdasarkan data magnetik meliputi parameter kedalaman, ukuran, dan suseptibilitas magnetik yang dapat diperoleh melalui pemodelan. pemodelan yang dilakukan dalam penelitian ini meliputi pemodelan ke depan dan pemodelan inversi untuk berbagai variasi parameter serta pemodelan inversi pada data magnetik WDMAM wilayah Ijen. Hasil pemodelan ke depan menunjukkan bahwa nilai medan magnet total akan semakin besar jika jarak kedalaman sumber anomali semakin kecil, suseptibilitas semakin besar, dan ukuran benda anomalinya semakin besar. Sedangkan hasil pemodelan inversi data sintetik menunjukkan kesesuaian yang cukup baik antara struktur bawah permukaan terhadap model sintetik awal.Hasil pemodelan inversi pada data magnetik satelit wilayah ijen dengan batas koordinat 8˚30’- 8˚39’ LS dan 113˚30’ - 114˚30’ BT menunjukkan struktur bawah permukaan berupa blok-blok prisma dengan suseptibilitas didominasi oleh mimeral magnetit, ilmenit, dan ada batuan pirotit dengan kedalaman yang bervariasi.
Practice in Making Notarial Agreements in Unregistered Marriage in Indonesia
Authors: Siti Bayturrochmah , Sjarif Fitriani A. , Tardjono Heriyono
Published: July 2022

This article aims to examine the legal force of the marriage agreement deed made by a notary, particular for those who are only married in an unregistered manner. In notary, it is known that there is a Marriage Agreement which is the authority of a notary to prepare an authentic deed in accordance with the provisions of the legislation on the basis of law. Based on the description above, a question arises whether the parties who carry out an unregistered marriage are able to state their wishes in a notarial agreement. What are the possibilities and legal consequences for both the parties and for the notary as a public official who prepares the deed of agreement. The research method uses in this research is normative legal research or normative juridical research with a statutory approach and a case approach. The data used is secondary data, while the analysis method uses qualitative analysis methods. The results of the study indicate that with certain adjustments, a notary is able to prepare a notarial agreement for the parties carrying out an unregistered marriage. The notarial agreement has perfect evidentiary power for the parties as is an authentic deed in general. A notarial agreement with certain adjustments prepared by the parties who entered into an unregistered marriage was prepared with the aim of providing legal protection for the parties.
The Law of Dropshiping Buying According to Madzhab Malikiyah and Syafi'iyah
Authors: Handoko Prio , Ibrahim Duski , Bukhari KA
Published: July 2022

This study aims to examine the sale and purchase of dropshipping which fall into the category of Salam, Ijarah and Wakalah contracts and laws according to the Malikiyah and Syafi'iyah schools of thought. The research method used is qualitative with primary data sources obtained by interviewing the sources, with secondary data in the form of literature studies of previous research and fiqh books of the Malikiyah and Syafi'iyah schools. The results of the study show that the dropshipping buying and selling system is included in Salam, Ijarah and Wakalah contracts, as Syafi'iyah's opinion allows salam contracts which have a short estimated delivery time, called salam haal and with cash advance payments when the transaction takes place. As for the Maliki school, it does not allow the salam haal contract because the estimated time for delivery of the goods is short.
Cymbopogon citratus (DC.) Stapf essential oil: Unraveling potential benefits on human skin
Authors: Faloni de Andrade Sérgio , Pinheiro Eucinário José , Pereira-Leite Catarina , do Céu Costa Maria , Monteiro Rodrigues Luis , Figueiredo Ana Cristina
Published: July 2022

The essential oil of Cymbopogon citratus (DC.) Stapf is widely used for the production of fragrances, cosmetics, and detergents. However, there is no information on the effects of formulations containing C. citratus essential oil (EOCC) on human skin. This study aimed to evaluate the effects of formulation containing EOCC on human skin physiology. The study involved participants of both sexes (n=12). Two areas (3 cm x 3 cm) were drawn on both forearms. One randomly chosen area was treated for 14 days, 2 times/day with polyacrylic acid gel containing 5% EOCC and the other was used as a control for the same time period. Transepidermal water loss (TEWL), hydration, epidermal lipids, and biomechanics were measured (D0 and D14). High resolution Sonography images were also obtained. Results revealed a significant decrease in TEWL, a significant increase in hydration, firmness and elasticity, and a decrease in lipids, in the areas treated with EOCC. Sonography showed an increase in echogenicity of the epidermis after applying the formulation indicating that the essential oil penetrates only the most superficial layers of the skin. Results also suggest that formulations containing EOCC are safe for topical application and can improve and protect human skin. Keywords: Cymbopogon citratus; essential oil; citral; lemongrass
ENERGY AND EXERGY ANALYSIS OF TYPICAL HEATING SYSTEMS
Authors: Kudelya P. , Dubovskyi S.
Published: July 2022

The main features of energy and exergy methods of analysis the energy transformations efficiency in typical heating systems (boilers, electric heating, heat pumps with electric drive) are presented. The equations of energy and exergy balances of systems and their elements are made. Based on them, expressions for calculating efficiency indicators are obtained. The results of calculations and comparison of energy conversion coefficients (COP - Coefficient of Performance) and exergy efficiencies (Exergy Efficiency or Second Low Efficiency) are presented. It is shown that heating systems based on fuel boilers and electric heaters are characterized by high COP values, which does not focus on taking measures to improve them. At the same time, such systems have rather low values of exergetic efficiency. It is shown that exergy efficiency of a typical electric heating system reaches about 3%, and heating based on fuel boilers - about 6,5 %. The analysis of the main reasons of thermodynamic irreversibility in the specified systems is executed. The diagram of changes exergetic efficiency in consecutive elements of a typical heating system on the example of a fuel boiler room is given. It is shown that in a fuel boiler the main irreversibilities occur at the stages of combustion and heat transfer at a large temperature difference. In electric heating systems, the main exergy losses occur during the production of electricity at thermal power plants and during the conversion of electricity into heat in electric heaters. Possibilities and main ways to reduce the thermodynamic irreversibility of the heating system from the steam boiler house during its conversion into a mini - CHP are considered. The analysis of thermodynamic losses in heat pump heating systems is performed. The conditions under which such systems become more energy efficient than systems based on fuel boilers are defined. The reasons for the wide practical application of boilers and electric heating are revealed, despite their low thermodynamic perfection.
ELECTROMAGNETIC COMPATIBLE CURRENT SOURCES WITH RELAY CONTROL
Authors: Bielokha H.
Published: July 2022

The development of industry leads to an increase in nonlinear loads, which are generators of higher harmonics in the network. The quality indicators of voltage and current consumed from the network are established by international standards for the quality of electricity. The simplest method of filtering harmonics is passive filters, lack of low quality harmonic compensation. The use of active filters improves the quality of the current. But active filters have a complex control system. The use of active rectifiers as part of semiconductor power supplies solves the problem of generating higher harmonics in the network and provides a power factor equal to 1.

 Six variants of three-phase and single-phase power supplies have been developed. They operate as a current source. All circuits consist of two parts: an active rectifier and a DC-DC converter. The scope of use of such sources is different: a direct current electric drive, an electric power system of wind turbines, an electric system of aircraft. The control system of the relay converters provides the formation of current and the maximum speed in the processing of disturbances.

Oscillograms of the current sources are obtained by digital modeling. They confirm the efficiency of the proposed sources, the electromagnetic compatibility of the power sources with the mains and the value of the power factor close to unity. Current sources are invarant to the action of disturbances: changes in load resistance, mains voltage. The study of electromagnetic processes made it possible to obtain analytical expressions for the maximum and minimum frequency of the relay mode, the capacitance of the capacitors and the operating conditions of the sources.

The developed program allows you to get the parameters for choosing the power elements of the circuit: inductance, capacitance, switching frequency of transistors.

The quality of the consumed current is analyzed by calculating the total harmonic distortion (THD). For all considered sources, the THD value is less than 5%, which meets the quality standards for the consumed current.
AUTOMATED SYSTEM FOR PROVIDING POWERFUL COMPUTING SYSTEMS WITH A COMPLEX OF EQUIPMENT
Authors: Varlamov G. , Segeda I. , Lokotarov Y. , Jiang Jianguo , Mitchenko I.
Published: July 2022

With the development of the cryptocurrency market, the need for automated support for mining hardware is growing. At present, there are practically no flexible systems for selecting equipment to fully meet the complex needs of providing complex features of mining processes, and software has not been developed that could take into account all the features of cryptocurrency developers. The purpose of this work is to develop the principles and algorithm for solving the problem of organizing the provision and selection of the necessary equipment for complex and powerful computing systems in the form of an automated system for the procurement and supply of the main computing and additional related equipment, organizing its installation, monitoring the conditions and characteristics of operation and subsequent output out of operation after the resource has been depleted or in order to increase the computational characteristics of mining farms and their cooling systems. Modern powerful computing systems are a huge amount of interconnected diverse equipment, located at different sites and interacting with each other by high-speed neural connections. The success of creating such complexes depends on the level of training of a team of specialists, which must have comprehensive and deep knowledge on the issues of building the engineering infrastructure of a computing complex, reasonable equipment with the necessary equipment, calculating the maximum energy load and providing such objects with a cooling system for computing elements and the system as a whole. Computing power is realized with the help of Data-centers, mining farms with more than 5000 computing modules. The problem of ensuring the quality of power supply of mining farms, a high level of efficiency in the use of power sources, protecting expensive equipment from overheating while ensuring high computing performance is very relevant, it requires constant attention and the use of special equipment and technologies. The developed system described in this paper relates to the management and optimization of resources of large computing centers, namely, to the organization of mass purchases of equipment, its installation and effective maintenance during operation, ensuring the efficient operation of cooling systems and the decommissioning of mining farms after completion. their work. This system allows users to create their own equipment catalogs in the form of models and then effectively organize the planning and management of devices in the form of an abstract model that consolidates all devices. Such a model is easy to control, find and perform actions on related objects, scale and make changes as needed. On the practical side, this developed product is simple in terms of the graphical interface and does not require much time for staff training and use in practice.
IMPROVING THE TRAFFIC SIGNS ACCURACY DETECTION WITH DIGITAL CALIBRATION OF WIDE-ANGLE CAMERA
Authors: Stadnichuk Vyacheslav , Kolobrodov Valentine
Published: July 2022

Problems. The analysis of statistical data shows that from year to year there are more and more vehicles on public roads, as result, the number of accidents increases and the risk for each road user increases. To ensure road safety, automakers are implementing driver assistance systems and cars with autonomous control elements. Such systems are capable of analyzing the environment and in the dangerous situations can correct the driver's actions or taking control of the vehicle. Typically, such systems work with the television systems help, one of the requirements for which is a wide angle of view. However, the main disadvantage of wide-angle systems is the large distortion, ie the geometric distortion of the similarity between the object and its image.

Objective. Develop an approach and algorithm for calibration of wide-angle cameras for autonomous driving.

Methods. Analysis and modeling of television car control system and its calibration.

Results. A comparison of wide-angle and conventional television systems was performed, each was calibrated and the analysis of the location of road signs of each of the systems was performed.

Conclusions. It has been shown that for the purposes of driving a car, it is possible to use wide-angle television systems with their subsequent calibration to eliminate geometric distortion between the object and its image. It is possible to use wide-angle television car control systems with a large value of distortion after its calibration. Studies have shown that the IoU metric on a wide-angle camera is almost the same as on a conventional camera, and the road sign was found even at the edge of the field of view.

The application of the developed method of calibration of wide-angle cameras in experiments preserves the geometric similarity between the object and its image at a much larger angle of view in such a camera. Image processing time is insignificant, because the current level of computer power allows you to process such operations in real time.
EXPERIMENTAL STUDIES OF INFORMATION SIGNAL-TO-RESISTANCE CONVERTER FOR AUTOMATIC CONTROL SYSTEM
Authors: Pivtorak Diana , Pavlovsky Oleksii , Tsybulnyk Serhii
Published: July 2022

Potentiometric sensors are widely used in the construction of automatic and automated process control systems. In potentiometric sensors, resistance is the output signal and its magnitudes depend on the magnitude of the input signal. voltage, current, digital code, angle of rotation, displacement or other signal is usually used as the input signal. In practice, the task of simulating of the signal which coming from the built-in potentiometric sensor is often appeared. An additional potentiometric sensor can be used to simulate the signal of the built-in sensor that allows setting the required resistance magnitude by changing any external parameter.

The model of the voltage-to-resistance converter is made. This model allows simulating the potentiometric state sensor of the controlled system. The experimental determination of its transfer characteristic at different ambient temperatures is carried out. This model is based on a two-channel conversion circuit, which includes a source of optical radiation and two photoresistors optically connected to it. One of photoresistors is connected to a current stabilizer, while the voltage on it is analyzed by a tracking circuit that changes the brightness of the optical radiation source according to the magnitude of the control voltage. The transfer characteristic of the converter in the initial section has an insensitivity zone, following by a rectilinear section. Within the insensitivity zone, a change in input voltage does not change the output resistance. The magnitude of the insensitivity zone is determined by the maximum voltage on the incandescent lamp that determines its brightness, as well as the minimum possible resistance of the using illuminated photoresistor. Within the rectilinear section, the output resistance of the converter is linearly related to the magnitude of the input voltage. The conversion error does not exceed 0.6 % at an ambient temperature of 20° C. When the temperature decreases to -20° С, the conversion error increases to 7 %, which is due to differences in temperature errors of the photoresistors using in the model.
COMPENSATION OF ROBOT-MANIPULATOR POSITIONING ERRORS IN WORK SPACE OF TECHNOLOGICAL EQUIPMENT
Authors: Sokolova Olena , Visloukh Serhii , Antoniuk Victor , Klotchko Tatiana
Published: July 2022

Industrial robots are widely used in modern enterprises. Although high repeatability of industrial robots can satisfy most process needs, their low absolute positioning accuracy in the workspace cannot meet the requirements of some high-precision tasks. An example, is that the action of a robot relies on real-time sample data rather than simulated data. The low absolute robot’s accuracy to positioning leads to the fact that work productivity is significantly different from what is expected. Therefore, the purpose of this paper is to analyze the developed program to increase the accuracy of robot-manipulator’s positioning in real time under the compilation with the programs of integration automation projects.

The paper considers the deformation of the links, which is one of the robot manipulator’s production errors. The effect of applied forces on the connections and links can affect the deformation of the robot posture in different ways, and these changes are difficult to account for using linear algebra, so recently the demand for "offline programming" has increased, which will allow you to simulate the work of a robot manipulator with a change in time and will have a reasonable price. Therefore, the application of artificial neural networks based on optimization algorithms to compensate for absolute error was considered. After analyzing the existing technical solutions, a genetic algorithm was chosen that satisfies the conditions of ease of implementation, clarity, lack of redundant calculations, flexibility to the data types used. The paper also presents a general scheme of algorithms for optimizing the parameters of artificial neural networks and an iterative process of finding optimal values of hyperparameters using a genetic algorithm.

After choosing the modelling method and optimization algorithm, the developed algorithm on an open data set was tested. The obtained results showed an increase in accuracy from 22 to 77% (positioning accuracy without the use of compensation methods). Therefore, this article describes a method of increasing the absolute accuracy of positioning under the condition of compilation with programs of integration automation projects. The result is a program based on the above method.
DETALIZATION OF RECOGNITION ALGORITHMS IN DIAGNOSING PATIENTS AND EVALUATING THEIR EFFECTIVENESS
Authors: Shulyak Oleksandr , Mnevets Anton
Published: July 2022

The issues of detailing recognition algorithms in order to increase the validity of their solutions in diagnosing patients are considered using the example of processing nephrology data. The training of algorithms with a teacher is implied. Procedures for detailing complexes of clinical signs and criteria for comparing such complexes in decision-making are proposed. This means dividing these objects into elements, extracting additional information for them from a priori and current data, and taking them into account in algorithms. Research in the work was focused on the development of software tools for detecting and evaluating additional reserves and opportunities for improving the quality of decisions of recognition procedures by extracting additional useful information from a priori and current data and using them in the process of detailing decision-making procedures. On a specific algorithm, various approaches to such detailing and to the study of its effectiveness were analyzed. Such detailing can be built on the basis of using the experience of clinical practice of observation of patients and their diagnosis in the form of training samples of symptom complexes and (or) observed signals in clinical cases with reliably confirmed diagnoses in the relevant databases.

Detailing these algorithmic procedures can lead to the emergence of a multi variance of possible solutions for differently detailed algorithms and require the use of additional procedures for generating a generalizing conclusion based on the results of their mutual consultation. The order and results of detailing are demonstrated in the MatLab environment on two modifications of the proposed algorithm. The introduction reveals the relevance and content of the research. Section 1 reveals the composition of a priori patient data in demo examples and the information that is extracted from them at the training stage. Section 2 proposes two modifications of the algorithm to detalize it. Section 3 proposes software procedures for the statistical evaluation of the performance of the detalization of the algorithms under study. Section 4 describes the refinement of algorithms by introducing weights into the decision criterion, taking into account the spread of values of clinical signs. Section 5 demonstrates the detalization of the algorithms taking into account the information content of the features. The conclusions summarize the results of the work. In general, they are positive.
Тестирование радиационного блока модели общей циркуляции нижней и средней атмосферы Земли
Authors: Федотова Е А , Fedotova E A
Published: July 2022

Изложены результаты тестирования двух радиационных блоков, используемых для экономичного расчета переноса излучения в модели общей циркуляции нижней и средней атмосферы Земли. Первый блок предназначен для расчета поля собственного излучения в диапазоне частот от 10 до 3000 см$^{-1}$, а второй блок - для расчета поля солнечного излучения в частотном диапазоне от 2000 до 50000 см$^{-1}$. В каждом из этих блоков используется своя параметризация оптических параметров воздуха в интервале высот от поверхности Земли до 90 км. При построении этих параметризаций учитывалось изменение газового состава атмосферы с высотой. Для численного решения уравнения переноса излучения использовался метод дискретных ординат. Результаты расчетов, выполненных с помощью указанных блоков модели, сравниваются с результатами line-by-line расчетов поля собственного излучения и поля солнечного излучения в нижней и средней атмосфере Земли, выполненных с очень высоким разрешением по частоте. Показано, что блок модели обеспечивает хорошую точность расчетов как при отсутствии облаков, так и при наличии облачных слоев с большой оптической толщиной.
Численное моделирование динамических процесcов в среде мелкодисперсных твердых частиц
Authors: Немцев Максим Юрьевич , Nemtsev Maksim Yur'evich , Меньшов Игорь Станиславович , Menshov Igor Stanislavovich , Семенов Илья Витальевич , Semenov Ilya Vitalievich
Published: July 2022

Рассматривается модельная система уравнений движения ансамбля твердых частиц, возникающая при континуальном описании двухфазных дисперсных сред. Особенности системы состоят в наличии разрыва скорости распространения слабых возмущений в фазе частиц при объемной доле плотной упаковки и возможности формирования вакуумных областей, свободных от частиц. Предлагается модификация метода Годунова на основе точного решения задачи Римана и приближенного HLL решения. Тестирование реализованных методов проводится на серии задач, являющихся аналогами известных газодинамических тестов Сода и Шу-Ошера. Рассматривается также задача о разуплотнении пристеночного слоя сжатых частиц. Описывается механизм отрыва частиц от стенки и формирование пристеночной вакуумной области. Результаты численных расчетов сравниваются с имеющимися аналитическими данными.
Machine learning models for predicting the number of COVID-19 patients in Ukraine and India
Authors: Khoroshun Ganna , Ryazantsev Oleksandr , Koverha Mark , Pokryshka Sergey
Published: July 2022

Models for predicting the number of patients with COVID-19 using machine learning methods have been built. The data for models are obtained from various official sources, including the World Health Organization, from the beginning of the epidemic to the present time. The data in Ukraine and India were selected to teach models for predicting the number of patients with COVID-19. Algorithms of linear regression for Ukraine and gradient boosting for India proved to be the methods that provided high accuracy of the forecast for the existing data. Data analysis was performed using the Python programming language with Sklearn library which is based on SciPy (Scientific Python). In addition, the XGboost gradient boost algorithm library was used. To develop the model, multifactor prediction of time series with the delays as predictors was chosen. It is established that the such characteristics as the date of the event, day of the week, week number, month affect to the model. Model errors are smallest and forecast accuracy were estimated with the best values of 0.83 for Ukraine and 0.75 for India. The built models allow to predict the epidemiological situation in the future, to coordinate actions in different areas of health care and to carry out reasonable preventive measures at the state level.
RESEARCH OF THE POSSIBILITIES OF THE C# PROGRAMMING LANGUAGE FOR CREATING CYBERSECURITY ANALYSIS SOFTWARE IN COMPUTER NETWORKS AND COMPUTER-INTEGRATED SYSTEMS
Authors: Pashynskykh Vladyslav , Meleshko Yelyzaveta , Yakymenko Mykola , Bashchenko Dmytro , Tkachuk Roman
Published: July 2022

The object of research in the article are the tools and capabilities of the C# programming language for the implementation of cybersecurity analysis software in local computer networks and computer-integrated systems. The relevance of the study is due to the importance of information security of computer and computer-integrated systems in government, military-industrial complex, private business etc., and due to the importance of training cybersecurity professionals in higher education to consider teaching examples in popular programming languages. The goal of the work is to research the possibilities of the C# programming language for the development of software that analyzes cybersecurity in local computer networks and computer-integrated systems. The tasks to be solved are: to develop software for scanning network device ports in computer networks and computer-integrated systems for information security audit, using tools and libraries of the C# programming language, to research the benefits and possibilities of using this programming language for this task. Research methods: theory of computer networks, object-oriented programming, theory of algorithms and data structures, theory of software testing. Conclusions. In this paper the possibilities and advantages of the C# programming language for developing  cybersecurity analysis software for computer and computer-integrated systems were explored. In the course of work software that analyzes information security in local computer networks and computer-integrated systems was developed. This software can be used for educational purposes in learning the C# programming language and cybersecurity of computer systems. The developed software has the potential to be further improved and applied in various fields to test the cybersecurity of local computer networks and computer-integrated technologies.
Genetic Mechanism of Geothermal Resources in the Qutan and Reshuizhou Geothermal Fields, Jiangxi Province, China: Evidence from Hydrogeochemical Characteristics of Geothermal Water
Authors: Liao Yuzhong , Liu Yanguang , Liu Feng , Lu Chuan , Zhao Gui
Published: July 2022

The hydrogeochemical characteristics and isotopic analyses of geothermal water are effective in the genetic study of a geothermal system. This study systematically investigated the geochemical and isotopic compositions of the geothermal water in the Qutan and Reshuizhou geothermal fields. The geothermal water in these two fields is of HCO3 (·F)-Ca·Na type and has undergone protracted water runoff and deep thermal cycle. Based on the mineral-water solubility equilibrium, the reservoir in the Qutan geothermal field has a temperature of 60–74°C and a depth range of 770–1003 m. The geothermal water in the Reshuizhou geothermal field has been mixed with cold water, which accounts for 58% in weight. The reservoir in the Reshuizhou geothermal field has a temperature range of 131-150°C and a depth range of 1953–2287 m. The geothermal water in the Qutan and Reshuizhou geothermal fields have 14C ages of 8251–7961 BC and 3514–2254 BC, respectively, which are consistent with the result of the 3H isotopic analyses. When recharging and transiting to geothermal water, the meteoric water underwent changes in geochemical compositions, which were dominantly controlled by water-rock interactions, including the precipitation of chalcedony and muscovite and the dissolution of calcite, fluorite, K-feldspar, and albite. In the Reshuizhou geothermal field, the hydrogeochemical compositions of the geothermal water are affected by cold water mixing.
Design and Analysis of Metamaterial Inspired Multiband Antenna for 5G Sub-Six GHz NR Frequency Bands and wireless applications
Authors: Saraswat Ritesh Kumar , Kumar Mithilesh
Published: July 2022

A metamterial triple band antenna for 5G New Radio portable devices and wireless applications WLAN/WiMAX/X-band is presented in this article. A modified Split Ring Resonator (SRR) based slotted octagonal shaped radiator is proposed to achieve triple-band characteristics for 5G Sub-6 GHz NR frequency bands n7/n38/n41/n74/n78, WiMAX (3.5 GHz), WLAN (5.8) and X-band (8-12 GHz) wireless applications. Proposed structure has the electrical dimension of 0.414 λ × 0.253 λ × 0.0184 λ (36 × 22 × 1.6 mm3) at 3.45 GHz and printed on FR-4 epoxy substrate. Antenna represents good impedance matching with 10 dB impedance bandwidth for resonating bands are 47.20% (2.46 - 3.98 GHz), 35.16% (4.97 - 7.09 GHz), and 65.66% (7.58 -14.99 GHz). In the operating bands, antenna attain the peak gain values of 2.56 dBi, 3.47 dBi, and 4.23 dBi at wireless standards WLAN, WiMAX, and X-band respectively. Antenna achieve optimum radiation efficiency of 83.48% and the average efficiency of more than 70% for all the resonant modes. The comparison of the simulated and measured results shows a good agreement.
Laparoscopic Aspiration for Fat-Rich Renal Angiomyolipoma: A Retrospective Analysis of Chinese Patients at a Single-Institute
Authors: Xie Jianwei , Luo Guangcheng , Wang Xiaotian , Li Jiaxing , Yin Bo
Published: July 2022

Background: This retrospective analysis was aimed at evaluating the clinical data of patients with renal angiomyolipoma who were treated by laparoscopic aspiration in our institution and summarizing our experience of preliminary surgery at a single center.Methods: We retrospectively analyzed clinical data of 13 female patients with renal angiomyolipoma who were admitted to and treated in Shengjing hospital from January 2016 to December 2019. We analyzed the patients’ preoperative, intraoperative, and postoperative data and performed renal function tests and CT during the follow-up.Results: Postoperative pathologic tests revealed renal angiomyolipoma in all patients. Twelve patients were successfully treated with laparoscopic aspiration, while one underwent laparoscopic partial nephrectomy half-way due to the small amount of fat in the tumor. The average maximum tumor diameter was 4.4 cm (range: 1.6–9.8). The average operation duration, blood loss, and postoperative hospitalization duration were 112.2 minutes (range: 60–180), 104.6 ml (range: 10–200), and 6.2 days (range: 5–10), respectively. Preoperative and postoperative creatinine levels were below the upper limit of normal values, with the mean preoperative and postoperative creatinine levels were 0.56 mg/dl (range: 0.44–0.98) and 0.57 mg/dl (range: 0.46–0.95), respectively. No postoperative complications or recurrence occurred during the average follow-up of 27.1 months.Conclusion: Our preliminary results indicate laparoscopic aspiration is safe, effective, and minimally invasive for treating renal angiomyolipoma, particularly for the rich-fat type.
Testing effects of partner support and use of oral contraception during relationship formation on severity of nausea and vomiting in pregnancy
Authors: Fiurašková Kateřina , Havlíček Jan , Kaňková Šárka , Klapilová Kateřina , Roberts S. Craig
Published: July 2022

Background: A recent study focusing on dietary predictors of nausea and vomiting in pregnancy (NVP) found that women with higher levels of partner support, and those who had use oral contraception (OC) when they met the father, both tended to report less severe NVP compared with previous non-users or those with less supportive partners. We provide a further test of these factors, using a large sample of women from four countries who retrospectively scored their NVP experience during their first pregnancy.Method: We recruited women who had at least one child to participate in a retrospective online survey. In total 2321 women completed our questionnaire including items on demographics, hormonal contraception, NVP, and partner support. We used ANCOVA and path analysis to analyse our data.Results: Women who had used OC when they met the father of their first child tended to report lower levels of NVP, but the effect size was small and did not survive adding the participant’s country to the model. There was no relationship between NVP and partner support in couples who were still together, but there was a significant effect among those couples that had since separated: women whose ex-partner had been relatively supportive reported less severe NVP. Additional analyses showed that women who were older during their first pregnancy reported less severe NVP, and there were also robust differences between countries. Conclusion: These results provide further evidence for multiple influences on women’s experience of NVP symptoms, including levels of perceived partner support.
Learning in a real-life escape room: an explorative study on the supervisory relationship in GP residency during the COVID-19 pandemic
Authors: Meljes Iris , Slootweg Irene , Nierkens Vera , de Bogaard Maartje van , Kramer Anneke
Published: July 2022

Background: The expert-novice dynamic in the relationship between supervisors and residents plays a prominent role in medical residents’ workplace learning. However, during the Covid-19 outbreak, both supervisors and residents faced unprecedented circumstances. In this study we explored the characteristics of the supervisory relationship in GP-residency during the disruptive pandemic to enhance our understanding of the changed dynamics between supervisors and residents. This is important, considering the new topics such as e-health and sustainable health in medical education.Methods: We conducted a qualitative study with a constructivist approach that included 7 GP residents at the start of their second placement, and their 10 supervisors. Participants came from a University Medical Centre in the Netherlands. Semi-structured interviews were held between September 2020 and February 2021. The subjects were interviewed individually (1st round) about what they had learned regarding COVID-19, and in supervisory pairs (2nd round) about how they had learned. Data were iteratively analysed; thematic analysis in round 1 and template analysis in round 2.Results: We identified notable changes in the supervisor-resident relationship attributable to COVID-19. Supervisors and residents were confronted with an all-encompassing uncertainty in the workplace, and disruptive changes in patient care and learning opportunities for residents. Supervisors and residents addressed emerging workplace challenges through three types of collaboration, 1) ‘getting the job done’; 2) residents’ learning; and 3) collective learning. Each type had a different focus and distinctive characteristics of the supervisory relationship. Conclusion: The outbreak of the pandemic caused an overwhelming sense of uncertainty. Under these circumstances learning did not only occur one-on -one, between resident and supervisor, but also with the entire team in collective learning. We propose stimulating collective team learning when GPs, residents, and other team members face new disruptive challenges in the field of medicine.
The effect of Pediococcus acidilactici probiotics supplementation in the feed of Nile Tilapia (Oreochromis niloticus) on water quality, growth performance, Hematological parameters, antioxidants, immunological responses, enzymatic Activity, and histology.
Authors: Eissa El-Sayed Hemdan , Alaryani Fatima S. , Khattab Marwa S. , Elfeky Amal , Eissa Moaheda E.H. , AbouelFadl Khaled Youssef
Published: July 2022

The effect of adding lactic acid bacteria (Pediococcus acidilactici) to the diet on water quality, feed utilization, growth, body composition, Hematological parameters, intestinal and liver histology of Nile tilapia, haemato-biochemical parameters, antioxidants, immunological responses, and Enzymatic Activity was investigated. Fish was distributed into Four groups; the control group (T0), T1 group (2.0 g), T2 group (2.5 g), and T3 group (3.0 g) of Pediococcus acidilactici per kg of diet. 25% of Water was changed daily and feed with 31% protein was added three times daily for 56 days. In probiotics-treated groups, growth performance, feed utilization, and fish biomass increased significantly compared to control. The biochemical and immunity parameters (Amylase, Lipase, and Protease activity) and villi height were significantly improved in probiotics groups. In conclusion, adding probiotics to fish diet improved all evaluated parameters
Substitution of fish meal with Madagascar cockroach (Gromphadorhina portentosa) meal in diets for juvenile Nile tilapia (Oreochromis niloticus): Effects on growth, nutrient assimilation and nitrogen turnover rates.
Authors: García-Pérez Oscar Daniel , Sanchez-Casas Rosa María , Moreno-Degollado Gustavo , Munguía Carlos Alberto García , Villarreal-Cavazos David Alonso , Gamboa-Delgado Julián
Published: July 2022

Among the wide variety of alternative ingredients aimed to substitute fish meal in aquafeeds, insect meals have been recently proposed as novel, nutritionally good dietary components. In the present study, early juveniles of Nile tilapia (Oreochromis niloticus) were fed five isoproteic and isoenergetic experimental diets formulated with varying dietary levels of Madagascar cockroach meal substituting fishmeal on a dietary protein basis (0, 25, 50, 75 and 100%). Diets were supplied for 29 days to eventually compare growth parameters among treatments and to estimate the relative assimilation of the dietary nitrogen supplied by fishmeal and insect meal. Nitrogen stable isotope analyses were applied to diets and fish muscle tissue to explore the isotopic changes elicited by the experimental ingredients and to estimate the nutritional contributions of these ingredients to fish growth. At the end of the bioassay no statistical differences were detected in final mean weight, specific growth and survival rates among treatments. Isotopic changes over time allowed calculating the nitrogen turnover rate in muscle tissue and the time required to reach isotopic equilibrium. The relative proportions of dietary nitrogen supplied by insect and fish meal were similar to the established dietary proportions. Cockroach meal in all mixed diets supplied relatively high proportions of dietary nitrogen (from 16 to 69%) to the biosynthesis of fish muscle tissue. Due to the high growth promoted by the diets, the nitrogen turnover rates in muscle tissue were short and ranged from 4.7 to 6.2 d, except in diet containing 100% cockroach meal (7.8 d).
Nutritional Quality and Labelling of Processed Foods Sold in the Kingdom of Tonga: A Pilot Study
Authors: Buechel Claire , Knight-Agarwal Catherine , Minehan Michelle , Pasikala Esiteli , Ferguson Maddie
Published: July 2022

Background: Small islands in the Pacific such as Tonga, have largely replaced their diet of locally sourced foods with imported, highly processed foods. This has contributed to a significant increase in prevalence of noncommunicable disease. The present pilot study aims to identify labelling quality, nutrient content, and availability of ready-to-eat processed food items sold in Tonga. Methods: An inventory of packaged snack foods was taken in three supermarkets in the downtown area of the country’s capital, Nuku’alofa. Health Star Ratings (HSR), country of origin, ingredient lists, and nutrient panel labelling were sourced from front of labels or online credible sources. Results: Out of food items identified, only 50% had legible nutrient panel information. Only 14% of products used the HSR scheme. Non-dairy beverages and confectionary formed the largest proportion of food items. The majority of items were high in sugar, total fat, saturated fat, and/or sodium. Trans-fats and dietary fibre were the most commonly unreported nutrients. Conclusions: The findings of this pilot study provide important evidence regarding the need to improve food labelling regulation in Tonga. Access to front of package nutrition information will help Tongan consumers make informed decisions regarding the processed food they purchase which, in turn, may help improve health outcomes.