bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Study on the Estimator Distribution for the Expected Value of a Compound Periodic Poisson Process with Power Function Trend
Authors: Safitri Nurul Indah , Mangku I Wayan , Sumarno Hadi 
Published: November 2022

This article discusses the estimation for the expected value, also called the mean function, of a compound periodic Poisson process with a power function trend. The aims of our study are, first, to modify the existing estimator to produce a new estimator that is normally distributed, and, second, to determine the smallest observation interval size such that our proposed estimator is still normally distributed. Basically, we formulate the estimator using the moment method. We use Monte Carlo simulation to check the distribution of our new estimator. The result shows that a new estimator for the expected value of a compound periodic Poisson process with a power function trend is normally distributed and the simulation result shows that the distribution of the new estimator is already normally distributed at the length of 100 observation interval for a period of 1 unit. This interval is the smallest size of the observation interval. The Anderson-Darling test shows that when the period is getting larger, the p-value is also getting bigger. Therefore, the larger period requires a wider observation interval to ensure that the estimator still has a normal distribution.Keywords: moment method; normal distribution; Poisson process; the smallest observation interval. AbstrakPada artikel ini dibahas tentang pendugaan fungsi nilai harapan Proses Poisson periodik majemuk dengan tren fungsi pangkat. Tujuan penelitian kami adalah, pertama, memodifikasi penduga yang telah ada untuk menghasilkan penduga baru yang memiliki distribusi normal. Kedua, menentukan ukuran interval pengamatan terkecil sehingga penduga yang diusulkan masih berdistribusi normal. Pada dasarnya, penduga yang kami usulkan diformulasi menggunakan metode momen. Kami menggunakan metode simulasi Monte Carlo untuk memeriksa sebaran distribusinya. Hasil menunjukkan bahwa penduga yang baru untuk fungsi nilai harapan Proses Poisson periodik majemuk dengan tren fungsi pangkat memiliki distribusi normal. Hasil simulasi menunjukkan bahwa penduga baru telah berdistribusi normal pada panjang interval pengamatan 100 untuk periode sebesar 1 satuan. Interval pengamatan ini merupakan ukuran interval pengamatan terkecil. Selain itu, hasil uji Anderson-Darling menunjukkan bahwa ketika periode semakin besar maka p-value juga semakin besar. Oleh karena itu, periode yang lebih besar memerlukan interval pengamatan yang lebih panjang untuk menjamin penduga yang kami usulkan tetap berdistribusi normal.Kata Kunci: metode momen; distribusi normal; proses Poisson; interval pengamatan terkecil. 2020MSC: 62E17
Development of tin copper alloys in shell and tube evaporator heat exchanger systems in ocean thermal energy converse power plant
Authors: Mawardi Mawardi , Wirjosentono Basuki , Ambarita Himsar , Koto Jaswar 
Published: November 2022

A case study of the manufacture of an OTEC factory on a floating ship has been carried out using 100 MW Titanium material at a fairly expensive cost, so the OTEC system was researched using a copper-tin alloy. The behavior of the tin-copper heat exchanger between the Aspen Plus simulation and the Computational Fluid Dynamics (CFD) simulation on Shell And Tube evaporators of Bonnet Divided Flow fixed and Bonnet One-pass Shell fixed (BEM) types is investigated. The difference in temperature between water at sea level of 29 °C and water at a depth of 1000 meters at a temperature of 5 °C is assumed to produce electricity. A marine thermal energy conversion power plant is a continuous source of energy sourced from nature an evaporator heat exchanger with ammonia working fluid will produce power that can drive a turbine forwarded to a generator. The simulation results of CFD of a Bonnet Divided Flow fixed type Heat Exchanger on the hot water inlet line has a temperature of 29.9 °C, when exiting the evaporator shell the temperature decreases to 26.4 °C. At the inlet line, the working fluid of ammonia enters the evaporator at 7.9 °C and when it leaves the tube, the temperature rises to 26.3 °C. The best results of the simulation of Aspen Plus Heat Exchanger type BEM Inlet Ammonia temperature 8 °C and at CFD 7.99 °C. Meanwhile, at the ammonia outlet at 28 °C and in the CFD simulation, the ammonia outlet temperature was 28.21 °C. Aspen Plus Inlet heating water temperature is 30 °C, and in CFD simulation, the temperature is 29.99 °C. While the heating water outlet is 28 °C, and in the CFD simulation, the heating water outlet is 28.15 °C. The conclusion from the simulation results is that the BEM-type heat exchanger is very good and suitable for experimental prototyping.
Identifying some regularities of radio frequency propagation of a radar system by analyzing different environmental effects
Authors: Hamza Ekhlas Kadhum , Aziez Sameir A. , Reja Ahmed Hameed , Sabry Ahmad H. 
Published: November 2022

Free space path loss is a function of frequency and propagation distance and the RF signal propagates at light speed in all directions in free space. The performance evaluation of wireless and radar communication technologies is related to understanding the propagation environments. This work presents the modeling of several RF propagation properties that include atmospheric attenuation due to rain, free space path loss, gas, and fog, as well as multipath propagations caused by ground bounces. The methodology discusses the developed model according to the series of (ITU) International Telecommunication Union references to radio wave propagation. This work discusses the Free Space Path Losses (FSPL), and Propagation Losses (PL) due to the atmosphere, precipitation, snow, rain, clouds, fog, atmospheric lensing and absorption, and polarization mismatch. The work also discusses the vertical coverage diagram and radar propagation factor. The obtained results demonstrate that the PL increases with frequency and range, at a 90-degree roll angle, the attenuation approaches infinity, and as the altitude rises, the amount of attenuation caused by lensing decreases. The analysis of attenuation at 1 km vs. frequency variations, at roughly 60 GHz, indicated a high absorption owing to air gas. Lensing attenuations are also offered as secondary outputs for convenience, the wideband channels present higher performance crossways and a wide range of target height as expected. When the target height increases, the influence of multi-path fading approximately vanishes entirely due to the variation increasing in the spreading delay between the bounce and direct pathway signals. This will reduce the coherence sum between these two samples on receiving by the target
Development and creation of a hydrodynamic liquid heating unit
Authors: Nussupbekov Bekbolat , Oshanov Yerlan , Ovcharov Michael , Mussenova Elmira , Ospanova Didar , Bolatbekova Madina 
Published: November 2022

The work is devoted to the study of the parameters of an installation for heating a coolant using liquid forcing through throttle openings. A scheme of a full-size experimental stand has been developed and the principles of operation are described in detail. For visual observation of the state of the liquid at different angular speeds of rotation of the rotor, a transparent drum model is made. The influence of the shape of the rotor skirt and the depth of its immersion in the liquid on the filling capacity of the rotor cavity at an angular velocity from 42 to 314 rad/s has been determined. The optimal parameters of the depth of immersion of the drum skirt with a diameter of 0.5 m in the liquid, at low rotor speeds of 16, 24, 32 rad/s, were obtained. The angle of inclination is calculated and it is experimentally proved that for a conical shape it is 5 degrees. It was found that at angular velocities of the rotor more than 100 rad/s, the shape and depth of immersion of the skirt in the liquid do not affect the filling of the rotor, since the feed is higher than its flow through the throttle openings. It is shown that the use of rotational forces to heat the liquid allows using an electric motor with less power, since it is spent only on unwinding the rotor with the liquid. The calculated dependence of the liquid pressure on the side walls of the rotor, the liquid heating temperature on the angular velocity of rotation of the rotor and on two values of the area of the throttle openings, at 31.4·10-6 m2 and 64.34·10-6 m2, is obtained. When the total area of the throttle openings is doubled, the temperature of the liquid heating at the same angular velocities increases from 35.6 °C to 82.5 °C. The above installation parameters allow you to get hot water when using small shell-and-tube heat exchangers
Determining the static characteristic of a measuring current transformer at a reduced load of the metering unit
Authors: Vasylets Kateryna , Kvasnikov Volodymyr , Vasylets Sviatoslav 
Published: November 2022

The object of the research is a measuring current transformer of the electromagnetic type, which is used as part of the electricity metering unit. The current transformers functioning in the mode of reduced primary current is accompanied by significant errors. The existence of such a regime for a long time due to downtime of production equipment leads to a significant underestimation of electricity. This leads to unjustified financial losses for energy supply companies as electricity in many countries has become more expensive. The static characteristic of the measuring current transformer at a reduced load of the metering unit is described by a linear statistical model. The parameters of the model are estimated on the basis of empirical data using methods of covariance analysis. The adequacy of the model is confirmed by analysis of regression residuals. The obtained statistical model of the static characteristic, unlike the known ones, is characterized by universality, as it describes current transformers with an arbitrary transformation ratio within the studied accuracy class of 0.5S. The uncertainty of the current error is estimated using the prediction intervals for the transformers secondary currents as a function of the primary currents, calculated on the basis of the obtained model. The prediction intervals for sample values of the current error were obtained through the application of the proposed approach for uncertainty estimation of such an error at a reduced load of the metering unit. It was found that the current error can reach −20 %. Taking into account the indicated intervals for measuring current transformers at a reduced load of the metering unit during billing will allow energy supply companies to increase the accuracy of commercial electricity metering.
Unraveling the study of liquid smoke from rice husks as a green corrosion inhibitor in mild steel under 1 M HCl
Authors: Kaban Agus , Mayangsari Wahyu , Anwar Mochammad , Maksum Ahmad , Aditiyawarman Taufik , Soedarsono Johny , Ridhova Aga , Riastuti Rini 
Published: November 2022

The work provides the more comprehensive development of Liquid Smoke from Rice Husks Ash (RHA). Notably, the study focuses on the interaction between the primary molecules of inhibitor and mild steel, including thermodynamic calculation and surface treatment upon addition of inhibitor. The electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP) characterization were utilized to evaluate the anticorrosion of RHA. The Raman Spectroscopy pre and post-addition of RHA’s inhibitor were used to compare the adsorbed functional group of inhibitors. Moreover, the thermodynamic calculation of the inhibitor’s adsorption determines the types of adsorption of the inhibitor. As a result of the adsorption process, the Scanning Electronic Microscope-Energy Dispersive X-Ray (SEM-EDX) aided by The Atomic Force Microscopy (AFM) and Contact Angle Test was implemented to unveil the surface treatment and the change of elemental composition after the addition of an 80 ppm inhibitor. The PP and EIS results show a significant depression of the current density at ‒2.75 μA·cm2 in 80 ppm solution with the highest inhibition efficiency of 99.82 %. The superior inhibition correlates to the adsorption of Si–OH, C–C, C–O–C, >C=O, complex structure, and –OH at wavenumber 458, 662, 1095, 1780, and 3530 cm-1. The LS shows a significant surface area of protection of 0.9982 and high adsorption constant (Kads) at 11.648. The calculated ΔGads of ‒6.59 kJ/mol unveils the chemisorption in nature. At the same time, a combination of 20 and 80 ppm solution is predicted adsorbed horizontally to reduce the contact between the solution and substrate, as shown in SEM and AFM results. It also increases the contact angle and their corresponding hydrophobicity
Development of rational technology for sodium glyceroxide obtaining
Authors: Korchak Mykola , Bliznjuk Olga , Nekrasov Serhii , Gavrish Tatiana , Petrova Olena , Shevchuk Natalia , Strikha Liudmyla , Kostyrkin Oleg , Semenov Evgeny , Saveliev Dmytro 
Published: November 2022

The process of sodium glyceroxide obtaining by the reaction of glycerol and sodium hydroxide in the form of an aqueous solution was investigated.
Glycerol salts (metal glyceroxides) are important components in the synthesis of many compounds. Glyceroxides are used in the chemical industry, construction, medical practice, etc. Glyceroxides of alkali metals are used in the production of modified fats and biodiesel fuel.
P.a.-grade glycerol (CAS Number 56-81-5) was used with a mass fraction of the main substance of 99.5 %. The parameters of sodium hydroxide (CAS Number 1310-73-2) were studied: the mass fraction of the main substance is 98.0 %, the mass fraction of sodium carbonate is 0.5%.
Rational conditions for sodium glyceroxide obtaining were determined: temperature (145 °C) and concentration of sodium hydroxide solution (65 %). Under these conditions, the mass fraction of the main substance in the product was 80 %. The melting point (72 °C) and mass fraction of moisture (0.3 %) in sodium glyceroxide were determined. The catalytic activity of the product in the process of transesterification of palm olein was tested. The increase in the melting point of palm olein was 15 °C. Under similar conditions of using potassium glyceroxide with a mass fraction of the main substance of 75.77 %, the increase in the melting point is 12.1 °C. This indicates an increase in the efficiency of the transesterification process using sodium glyceroxide obtained by the developed technology.
The research results make it possible to produce sodium glyceroxide under rational conditions with a high mass fraction of the main substance at enterprises that use metal glyceroxides as a production component or commercial product. The determined rational conditions will make it possible to effectively use the company's resources and predict the quality of the final product
Application of paper mill sludge and additional chemical substances in the production of container cardboard
Authors: Halysh Vita , Trus Inna , Radovenchyk Iaroslav , Shabliy Tetyana , Ivanchenko Anna , Nikolaichuk Alina , Gomelya Nikolai 
Published: November 2022

The possibility to dispose of paper mill sludge as part of a composition of container cardboard from secondary raw materials has been investigated. The fractional composition of the sludge was studied and it was shown that the main part of the fibers is represented by small particles with a size of up to 1.2 mm. Studying the processes of formation of container cardboard when using paper mill sludge showed that an increase in the consumption of fibrous-inorganic waste leads to a deterioration in the physical and mechanical properties of cardboard. However, the increase in sludge consumption does not affect the surface absorption of water during one-sided wetting. The value of these indicators is within the normal range and is 25 and 70 g/m2, respectively. In addition, an increase in sludge consumption from 10 to 50 % in the manufacture of cardboard leads to a decrease in the degree of fiber retention on the grid from 86.3 to 82.1 %. Regularities of using strengthening additives, namely industrial cationic and anionic flocculants, as well as native corn and modified starches for the strength of cardboard and the quality of sub-grid waters, have been established. Research results show that the effect of flocculants is quite ambiguous. On the one hand, there is a clearly observed positive impact on the quality of the sub-grid waters. This is due to the reduction of their turbidity due to smaller fiber washes. Nevertheless, the positive effect on physical and mechanical parameters is minimal, and in some cases, there is a decrease in strength indicators. The greater the efficiency of keeping fine fiber on the grid when using flocculants, the lower the values of physical and mechanical indicators. In general, when using sludge in the composition of cardboard in combination with flocculants and starch, the indicators were achieved that are considered standard for waste paper container cardboard of grade KT-1 according to TU U 17.1-41085075-002:2017
Influence of substitution of wheat flour with modified potato starch on the quality of Chinese steamed bread
Authors: Deng Chunli , Melnyk Oksana , Luo Yanghe 
Published: November 2022

The application of potato starch in flour products is very important for potato staple food. The gluten protein of wheat flour will be weakened after being mixed with potato starch, which could have inhibitory effect on quality properties of flour products. Therefore, it is, it is necessary to study the influence of substitution wheat flour with potato starch on the quality of Chinese steamed bread (CSB), which is an important staple food in North China.
This study investigated the effect of potato starch modified by heat-moisture treatment (HMTS) and microwave treatment (MWS) as wheat flour substitute in the making of CSB. The research results showed that the specific volume of CSB decreased with more incorporation of HMTS or MWS. The differences color (ΔE>3) between the control and experimental CSB were detectable by the human eye when the substitution level of HMTS or MWS was higher than 30 % or 20 %, respectively. Texture properties of CSB were affected with substitution due to the disruption of dough structure, and the incorporation of HMTS or MWS led to firmer and denser structure of CSB. The total sensory score of CSB decreased with more incorporation of HMTS or MWS. CSB can be accepted by consumers when the substitution level of wheat flour with HMTS or MWS was lower than 30 %. In general, the research results revealed that modified potato starch (HMTS and MWS) incorporation levels affected the specific volume, color, texture properties and sensory evaluation of CSB. This research can provide comprehension of the influence of modified potato starch (HMTS or MWS) on CSB and provide valuable guidance for further application of potato starch in wheat-based products
Development of a fake news detection tool for Vietnamese based on deep learning techniques
Authors: Vo Trung Hung , Phan Thi Le Thuyen , Ninh Khanh Chi 
Published: November 2022

With the development of the Internet, social networks and different communication channels, people can get information quickly and easily. However, in addition to real and useful news, we also receive false and unreal information. The problem of fake news has become a difficult and unresolved issue. For languages with few users, such as Vietnamese, the research on fake news detection is still very limited and has not received much attention.
In this paper, we present research results on building a tool to support fake news detection for Vietnamese. Our idea is to apply text classification techniques to fake news detection. We have built a database of 4 groups of 2 topics about politics (fake news and real news) and about Covid-19 (fake news and real news). Then use deep learning techniques CNN (Convolutional Neural Network) and RNN (Recurrent Neural Network) to create the corresponding models. When there is new news that needs to be verified, we just need to apply the classification to see which of the four groups they label into to decide whether it is fake news or not. The tool was able to detect fake news quickly and easily with a correct rate of about 85 %. This result will be improved when getting a larger training data set and adjusting the parameters for the machine learning model. These results make an important contribution to the research on detecting fake news for Vietnamese and can be applied to other languages. In the future, besides using classification techniques (based on content analysis), we can combine many other methods such as checking the source, verifying the author's information, checking the distribution process to improve the quality of fake news detection.
Determining the thermoplastic deformation mechanism of titanium reduction reactors and recommendations to increase the reactor service life
Authors: Mishchenko Valeriy , Loskutov Stephan , Kripak Alona 
Published: November 2022

The object of research reported in this paper is the stressed-strained state of reactors when producing titanium sponge by the magnesium thermal method, taking into consideration the conditions of their operation and the physical and mechanical properties of the materials.
The problem considered is the plastic deformation of the reactor in the process of reducing titanium tetrachloride. To solve this task, an axisymmetric geometric model of the reactor was built using a CAD module of the Comsol Multiphysics software package. For the calculation, the Nonlinear Structural Materials module was used. Owing to the method of finite elements, the critical parameters for the formation of the plastic deformation band of the reactor were determined.
Modeling the process of thermoplastic deformation of the reactor under the conditions of obtaining titanium sponge has made it possible to determine the temperature gradient in the upper part of the reactor wall, which leads to local plastic deformation of the wall. The solution to the problem of continuing the reactor service would be to prevent overheating (overcooling) of the reactor wall within the resulting temperature. The physical and mechanical parameters of the material of the reactor wall, necessary to prevent the occurrence of an annular band of plastic deformation, have also been determined. It was shown that at ∆T˃∆Tcrit=60 °C, the walls of a 10-ton reactor during the reduction of titanium tetrachloride with magnesium perceive plastic deformation whose maximum value can reach
Deformation mechanisms that lead to a change in the shape of the side wall of reactors of magnesium-thermal production of sponge titanium under the action of a heterogeneous temperature field have been determined. The proposed technological solutions are to eliminate local changes in diameter in the upper part of the reactor wall. This will make it possible not only to increase the life of the reactors but will reduce the flow of alloy components into the titanium sponge of nickel, chromium, and iron