bluuebunny/crossref_metadata_2025 huggingface dataset:
The influence of the chemical composition of aluminum on the quality of coatings formed using microarc oxidation
Authors: Snezhko A A , Strekaleva T V , Zakharova N V , Vasilyeva E K , Karelina E A
Published: December 2022

The paper discusses the influence of the chemical composition of the base material on the performance characteristics (hardness, thickness, wear resistance) of oxide coatings formed by microarc oxidation on aluminum alloys. The possibilities of forming the preferred high-hard phase α-Al2O3, as well as oxides of alloying elements in aluminum alloys, are being studied. The thermodynamic analysis carried out in conjunction with the results of experimental data will make it possible to predict the composition of a coating, thereby obtaining protective coatings with desired properties on aluminum alloys.
Fatigue crack growth kinetics in titanium alloys at different interaction of cyclic loading amplitudes
Authors: Savkin A N , Sedov A A , Badikov K A , Baryshnikov A A , Zaharov I N
Published: December 2022

Fatigue crack growth kinetics of various titanium alloys BT6 (α+β structure) and 3M (α-structure) under constant amplitude loading with different types of cyclic disturbances in the form of over- and underloading at a loading frequency of 25 Hz was investigated.The tests were conducted on a servohydraulic testing machine under controlled load with simultaneous automatic recording of loading parameters and readings from a crack opening gauge. Tests were carried out on compact specimens with an edge crack which were subjected to off-centre loading. The crack opening data was converted into crack length using a yield strength measurement method. Experimental results, namely fatigue crack growth curves and fatigue fracture kinetic diagrams, were analyzed. It is shown that crack growth kinetics depends mainly on the type of alternating loading amplitude sequences. Reliability estimation of crack growth on the basis of crack opening gauge and study of fractographic features of materials fracture has been carried out.
Air-water cooling mathematical model in cooling towers with vertical contact grilles
Authors: Kryuchkov D A , Ivanyakov S V
Published: December 2022

This paper examines the fan cooling towers with vertical contact grilles operation. The water-air cooling process a general mathematical model in cooling towers has been developed. Water-air interaction peculiarities on contact vertical grids have been considered, which allowed to obtain functional dependences for heat and mass exchange coefficients determination taking into account the cooling tower sprinkling devices design peculiarities under consideration.
Assessment of the quality of drinking water of the Republic of Kalmykia by trace element composition
Authors: Kh Sangadzhieva L , Davaeva Ts D , Sangadzhieva O S , Yessenamanova M S , Manzhikova A V
Published: December 2022

The article presents the data of the environmental assessment of the degree of contamination of drinking waters of Kalmykia. The assessment based on analyses of drinking waters of the republic’s districts, monitoring of drinking sources for 10 years, calculation of pollution coefficients. Today, 45 settlements of the republic, where 70.2% of the population of Kalmykia lives, provided with centralized and mixed drinking water supply. Residents of 140 settlements with a population of 60 thousand people (20.5% of the total population) in 4 districts (Iki-Burul, Priyutnensky, Oktyabrsky, Yashkulsky, Lagansky districts) are provided with imported water and delivered by special water carriers, water is delivered by rail from Dagestan to Ulan-Hall station. As representative indicators, the ratio of calculations of the values of excess of MPC by macro- and microelement composition was chosen. The results obtained rank the SRM by water quality class as, very clean in three rural municipalities (SRM), moderately dirty make up the majority - nine SRM, polluted and dirty - three SRM. This assessment of water quality coincides with the assessment of water exceeding the standards for individual indicators. A high value of this indicator indicates possible sources of pollution.
Problems of improving the regulatory and methodological base of metrological support
Authors: Priimak E V , Razina I S
Published: December 2022

The global mechanisms of modern society, including the formation of a global market and the expansion of foreign and domestic trade have led to increased demands on the quality of products and services. Information about the quantity and quality of manufactured products is obtained as a result of measurements. Metrological activity has a significant impact on the acceleration of scientific and technological progress, improvement of product quality and production efficiency. Therefore, the interrelation of the level of metrological support with indicators of product quality, rational use of energy and raw material resources is obvious. All this causes growth of requirements to the accuracy of used measures (mass, length, volume).
Simulation of ionospheric parameters for September 2017
Authors: Maltseva O , Nikitenko T , Kharakhashyan A
Published: December 2022

Modeling the parameters of the ionosphere is an important part of the process of studying the influence of space weather factors. This paper is devoted to modeling three parameters of the ionosphere (critical frequency foF2, total electron content TEC, and equivalent slab thickness τ) related to the possibility of determining foF2 on a global scale using TEC. Comparison of the model τ(IRI), τ(IRI-Plas) adapted to the observational TEC, τ(NSTM) with the observational median τ(med) for four ionosondes along the 30° E meridian in September 2017 showed the best fit for the IRI-Plas model. Using a polynomial approximation of τ(med) and the distribution of TEC along this meridian in the range of 30° N-70° N, the features of the response of TEC and foF2 to disturbances in September 2017 were revealed. The results for September 7-8, which showed positive enhancements of TEC and foF2, coincide with the results of other researchers. The similarity of this response with the response to the disturbance on September 27-28, which is not associated with a solar flare, is revealed. It is shown that the unique enhancement on September 11 during the magnetic storm recovery phase, identified in the Asian-Australian sector (Lei et al., 2018), is not observed at the 30° E meridian. The global longitudinal distributions of TEC at latitudes of 50° and 30° showed the locality of this phenomenon.
Conditions for effective detection of the boundary between the oil-covered and clean sea surface in the IR range
Authors: Novikova Yu A , Ryzhikov M B
Published: December 2022

This study is devoted to evaluating the most effective conditions that allow detecting oil pollution on the water surface using an on-board lidar operating in the infrared range. The results of the CO2 – lidar simulation show that even in the presence of a highly agitated sea surface, difficult weather conditions and low optical visibility, it is possible to search for the boundary between the water surface and oil from a flight altitude of 250-300 meters.
Cathodic protection of main oil pipeline
Authors: Skuridin N N , Tyusenkov A S , Bugai D E
Published: December 2022

Corrosion damage to metal is one of the main factors that reduce the safety of operation of main pipelines. It is known that about 70 % of pipeline failures occur due to metal corrosion. Electrochemical protection in combination with non-metallic coatings is currently the main method to prevent aggressive effects of corrosive media on main pipelines. The use of these methods of protecting pipelines has a number of difficulties that can be associated with the use of several protective coatings of different types and conditions on one oil pipeline; use of cathodic stations of different design and efficiency; Lack of a system to monitor electrochemical protection objects; difficulties arising during operation of anode grounding electrodes and comparison electrodes. Under these conditions, bringing the technical condition of the anti-corrosion protection system of the main oil pipelines to the level corresponding to the modern requirement of industrial safety is an important task that allows improving the safety and reliability of pipeline transport facilities. The article provides an analysis of the operation of cathodic protection units of the Kaltasy-Yazykovo main oil pipeline and the results of calculations on optimizing the modes of the cathode stations.
Properties and indicators of metrological reliability of measuring items
Authors: Zhirnova E A , Yakimova L D , Kuzmich R I , Snezhko A A , Zhoga R A
Published: December 2022

The issues of metrological reliability of measuring items are investigated. The conceptual terminology of the theory of reliability is analyzed in relation to measuring items. The regulatory and technical requirements for the reliability of measuring items are considered. The classification of failures of measuring items is carried out. A model is constructed in the form of a tree diagram that characterizes the properties and indicators of the reliability of measuring items. The necessity of standardization of regulatory and technical requirements for the metrological reliability of measuring items is substantiated.
Application of strain-sensitive graphite layers on fabric
Authors: Lozitskaya A V , Kondratov A P
Published: December 2022

The possibility of manufacturing wearable electronics elements, for example, strain gauges or antennas of RFID tags, by applying or locally applying a layer of electrically conductive graphite polymer compositions to the surface of a fabric (knitwear) using printing technologies has been studied. The pliable tape-shaped prints can be used as strain gauges to be placed on human clothing or robot arms. The tensile limits of sensors made on fibrous substrates of various structures using graphite dispersions in the form of powders and aerosols have been established. The strain sensitivity coefficients of the sensors are determined. The advantage of glueless spraying of a liquid composition of graphite in the form of an aerosol onto fibrous materials is shown.
Synthesis technique for control of a CMG Stabilization of an inverted pendulum which does not require repeated code generation
Authors: Prutskii A S , Mikhalkov N V , Vasiliev E Y
Published: December 2022

The article presents a synthesis technique for controlling the stabilization of a reverse pendulum, which does not require repeated code generation when making changes to the parameters of the control object. The problem of developing a feedback control system for a reverse pendulum controlled by a gyrodine is considered. The main tool for developing a control system is a combination of a real-time control system based on STM32 and an external computer based on ROS.
Tip vortex trajectory in proximity to the heliport
Authors: Ruchala P , Stryczniewicz W
Published: December 2022

The last decade has brought a significant increase in the number of heliports built in Poland mostly for medical purposes to enable helicopter medical transport directly to the hospital. Some hospitals, however, could not build ground-level heliports due to limited space in densely populated areas. The solution to this problem can be elevated rooftop heliports. The main drawback of elevated heliports can be vibrations of the whole building, caused primarily by unsteady rotor slipstream which impinges on the heliport surface during take-off and landing. It is especially awkward in case of medical heliports due to strict vibration requirements. The frequency of these vibrations is known to equal a blade passing frequency of about 25 Hz for the Eurocopter EC-135 that is commonly used by, e.g. Polish medical service. However, the pressure measurements made by the authors showed that a low-frequency component of pressure oscillations of a significant amplitude is recorded in the outer part of the rotor disc. To explain the source of this component, we performed a PIV measurement of the velocity field in rotor slipstream. An object of investigation was the remotely controlled T-REX 450 Pro helicopter with a rotor diameter of 0.7 m. A key conclusion is that tip vortices from blade tips are located roughly along the Archimedean spiral, but vortices distanced from the blade tip shift up and down (or towards the blade tip and rotor axis) in a periodical manner.
Application of unsupervised machine learning techniques to assessment of quality habitat
Authors: Kirichenko-Babko M , Danko Y , Danylkiv J , Babko R , Majerek D
Published: December 2022

As a result of human activities, river valleys have changed: river beds have been transformed as a result of their regulation and dam construction. This paper presents unsupervised machine learning techniques to distinguish arthropod communities and attempts to explain the ecological priorities of individual species based on them. Data on a group of 95 species of carabid beetles from 16 habitats on the floodplains of two rivers - Bytytsia and Strilka (Dnipro basin, Ukraine). Analyses were performed using the program R version 4.1.1. Fuzzy clustering was performed using the fanny function from the R cluster package, and visualization of the results was performed using the t-SNE method from the Rtsne package. In our analysis, the following habitat type characteristics were chosen to distinguish communities: closed (forest) or open (grassland). According to the results of fuzzy clustering, out of 95 carabid species, 37 species were selected whose probability of belonging to their cluster was at least 0.95. These species form distinct three groups. The first group of carabid species is associated with forest sites in Bytytsia. The second group is connected with occurrence on meadow sites in Strilka. The third group of species is connected mainly with the meadow sites of the Bytytsia River. Established groups of species reflect the current ecological situation on floodplains and the influence of human activities on it.
Evaluation of the efficiency of the mixing system of the laboratory SBR-type reactor
Authors: Staniszewski M , Zaburko J , Babko R , Szulżyk-Cieplak J , Widomski M K , Szeląg B , Łagód G
Published: December 2022

Requirements for the continuous improvement of the quality of wastewater discharged to a receiving water body have led to the development of many devices used in biological treatment. Current research in water and wastewater solutions often focuses on finding energy-efficient solutions that have the least negative impact on the environment while reducing operating costs. Treatment systems commonly use the properties of microorganism structures in the form of activated sludge flocs to remove organic and nutrient compounds contained in wastewater. An important part of this solution is the use of a mixing and aeration system in the appropriate configuration. In a wastewater treatment plant with a biological part operating with SBR technology, many types of mixing equipment are used. This article presents the use of an innovative mixing system in sequential batch bioreactors in which activated sludge is the process medium.
Mathematical analysis of an electric car in the aspect of the application of renewable energy sources
Authors: Geca M J , Soeurn M
Published: December 2022

This paper presents a model of an electric car based on the BMW i3 whose low-voltage electrical system and traction battery were supported by a photovoltaic system installed on the body of the vehicle. The photovoltaic system was installed on the roof, side doors and bonnet. The 350 Wp (Watts peak) system was made of semiflex panels. The input parameters for the model were the measurements taken during the simulated annual operation of the vehicle as driving time, weather conditions and their switching times. During stationary tests, the power of individual electrical consumers was measured and its maximum was 1.1 kW. The model included data on the electricity consumption for driving a given distance. The amount of electricity generated by the photovoltaic system was related to a stationary system of 4 kWp. The degree of shading and curtailment of energy generated by the photovoltaic system was measured during testing on a vehicle driving in urban conditions. In the vehicle under analysis, an additional energy stream supplied the 12 V electrical consumers and recharged the battery. The traction battery used to drive the vehicle during such a power supply scenario may increase the vehicle range by about 16% on average.
Development of the automatic method of detection and grouping of external welding imperfections
Authors: Brzeskot P , Łatka L
Published: December 2022

The non-destructive testing of welded joints is a key issue in welding technology and processes. It is especially crucial for estimation of product quality. Among others methods, visual testing is the most fundamental. In most cases, it is made manually, which can introduce some problems resulting from the lack of objectivity and fatigue of the controlling person. This paper is an attempt of changing a mode of visual inspection. The proposed system is based on image analysis of welded joints. The welding imperfections were correlated with quality levels according to the ISO 5817 standard. For the original inspection system, six the most fundamental imperfections have been selected. The main idea of this system is a detection of selected welding imperfections and, based on acceptance criteria, assigning welded joints for the appropriate quality level. In order to validate the correct operation of the proposed system, the same welded joints have been subjected to conventional manual visual inspection. The compliance of the results was more than 90%, and the speed of visual examinations was more than 10 times higher than in the manual method.
Airframe design and CFD analysis of light unmanned reconnaissance aircraft
Authors: Sawa M , Szala M , Jakliński P , Pietrykowski K
Published: December 2022

This work deals with a comparative numerical finite volume method of airflow for a 3D airframe model. The analyzed airframe model allowed 3-vector thrust directing while using the geometry of the inverted delta, which increases lift force area, allows for vertical take-off and landing, as well as full control of its flight using rotating propulsion nacelles and an airframe control system. The airframe model dimensions were 3900 x 3250 x 915 mm, enabling the installation of components of specific dimensions. CFD analysis using a four-equation transition SST model with automatic surface roughness and initial conditions: T = 288K, viscosity η= 1.7894∙ 10−5

k
g

m

·

s

and was carried out in the FLUENT module of ANSYS 16.0. For each simulation, 2000 iterations were performed with the intention of achieving a convergence of all residuals below 1∙10-3 using a calculation mesh consisting of 500,000 elements and 150,000 nodes. The model uses aerodynamic profile geometries: CLARK Y, NACA 6409, and NACA 2414, which are provided to obtain the optimal aerodynamic characteristics and determine the optimal range of angles of attack for the designed solution. Those angles of attack were in the range of α = 5 ÷ 10° in which the highest excellence coefficient of the carrier airfoil profile occurs. For those values of parameters optimal lift and drag forces were determined
Metrological evaluation of heterogeneous surfaces obtained by water jet cutting technology using artificial intelligence elements
Authors: Marcaník M , Kubišová M , Pata V , Novák M , Vrbová H , Knedlová J
Published: December 2022

This paper deals with the design and construction of a neural network for predicting the results of roughness parameters for heterogeneous surfaces. At the same time, it demonstrates that other statistical methods, especially regression analysis, fail in this respect, and their results cannot be used reliably. The samples produced using waterjet cutting were used to obtain the necessary data for constructing the neural network. Its heterogeneity characterizes this surface. This paper describes these samples, the parameters of their creation, the laboratory measurements, the complete construction of the neural network and the subsequent comparison of the results with regression functions. This paper aims to design a functional neural network that will best describe the roughness pattern of the surface under study. This neural network will predict this waveform based on the input variables and prove that this advanced statistical method completely exceeds the capabilities and predictive value of conventional regression analyses.
Influence of geometric parameters and material properties of the reinforcing core on the modal properties of vibrating beam structures
Authors: Rolník L , Bucha P , Lovíšková J , Naď M
Published: December 2022

The beam structures are considered as fundamental structural elements that are widely used in mechanical and building structures. One of the important tasks in the structural design of beam structures should be the ability to prevent or reduce the level of unwanted vibrations. It is obvious that the dynamic properties of beam structures depend on their shape structure, i.e. from their geometric parameters and material properties. Usually, the beam structures have constant cross-section and made of homogeneous material. However, these structures in many cases do not have the required dynamic properties. The design and analysis of the beam structures that will allow its spatial properties (mass and stiffness) to be redistributed using the sliding core inserted into the beam structure is investigated in this paper.
Comparison of reliability functions of simple mixed four-element systems
Authors: Labašová E
Published: December 2022

The paper deals with the comparison of reliability function, mean time to failure, and hazard rate function for simple mixed systems. Simple systems are those that can be divided into a sequence of series and/or parallel subsystems. The paper compares systems consisting of four subsystems; a total of seven systems are compared. A system with four parallel arranged subsystems is also included in the paper, for which the mean time to failure has the largest value. A system with four series-arranged subsystems is also included in the paper, for which the mean time to failure has the smallest value. The MATLAB program was used for the solution.
A statistical approach in the FEM simulation analysis of geometrical product specification during the cold tube drawing process
Authors: Necpal M , Morovič L , Bočáková B
Published: December 2022

The cold drawing process produces high-quality tubes with precise dimensions, good surface quality, and higher strength due to cold forming. The tube drawing is used to reduce the cross section of the produced tubes. Depending on the reduction size, the outer diameter and wall thickness of the final tube changes. Due to the fact that cold drawing of tubes is mostly the last operation of production, it is necessary to pay attention to the process parameters and geometry of the forming tools. This paper presents a statistical evaluation of the influence of the wall thickness of the pre-tube, die diameter, and pre-tube diameter on the measured responses, which were the outer diameter and wall thickness of final tube, after the FEM simulations of the drawing process. For these purposes, a factorial design with three input factors was implemented. The goal of using the simulations was also to investigate whether the single-pass type of tube drawing would guarantee useful statistical results that could lead to significant time and cost reductions. The FEM simulations were executed using DEFORM software of Scientific Forming Technologies Corporation with Design of Experiment application module of this software. A factorial design of experiment has been processed in Minitab v. 17 software. The results show that most of the factors significantly influenced the response variables.
Cerium and europium doping of Ruddlesden-Popper aluminate phases and their radioluminescence properties
Authors: Rubešová K , Havlíček J , Jakeš V , Kučerková R , Nikl M
Published: December 2022

Although many scintillator detectors with the fast and efficient detection of high-energy radiation are commercially produced, new materials are still of great interest. Oxide matrices doped with ions possessing fast and intense 5d–4f radiative transition are one of the researched groups of materials. So called Ruddlesden–Popper phases are structures combining halite-like and perovskite-like structures. The aluminates subgroup (AII

n+1-yAIII
y)
n+1 Al
n
O3n+1 has been only rarely studied for scintillation use. These phases are stable oxides with a relatively high density and, moreover, they melt congruently, which enables growth from a melt. In this study, we tested Ce3+- and Eu2+-doped (Sr,Ca)1(Gd,Y)
n
Al
n
O3n+1 (n = 1; 2) analogues. The samples were prepared by the chelating sol-gel method combined with the annealing in reducing atmosphere to reduce both ions to the intended valence. After the samples were characterized by X-ray diffraction, radioluminescence was used for the basic study of luminescence behaviour of Ce3+ and Eu2+ ions. While Ce3+-doped samples exhibited the 5d-4f radiative transition, Eu-doped samples manifested only luminescence spectra characteristic for Eu3+ ions.
Mold growth on pine and spruce wood: Dependence on moisture content, anatomical direction, and mold species
Authors: Ryparová P , Kopecký P , Richter J , Staněk K
Published: December 2022

Better knowledge about the conditions for mold growth on wood could improve mold growth prediction models, prevent health risks, and increase the durability of wood without any additional biocidal treatment. Mold growth depends on the surrounding condition and the available nutrients. The most effective measure to prevent mold growth in wood-based houses is to keep the indoor relative humidity sufficiently low. We studied the dependence of mold growth on ambient relative humidity (75 - 95 % RH) at 23 °C with respect to the anatomical direction of wood and mold species. The samples were prepared from pine and spruce sapwood. The monitored parameters were the time of germination and the first macroscopic observation. Mold growth started at relative humidity higher than 75 %. Liquid water retarded mold germination. The germination time varied between 7 and 24 days in the absence of liquid water in the samples. The time from the first macroscopic observation ranged from 19 to 31 days under conditions without liquid water. Wetting the samples increased the time required to observe the first fungal growth at the microscopic and macroscopic levels. The use of variable humidity in the range of 75 – 95 % RH extended the time required for germination.
The influence of multilayer architecture on the structure and mechanical properties of WNx/TiSiN coatings in comparison with WNx and TiSiN single layers
Authors: Sahul M , Bočáková B , Smyrnova K , Haršáni M , Sahul M , Truchlý M , Kusý M , Pogrebnjak A , Čaplovič Ľ , Vopát T
Published: December 2022

The present work deals with the comparison of selected properties of WNx/TiSiN multilayer and respective WNx and TiSiN monolithic coatings that were deposited at the same parameters. The effect of the multilayer architecture on the structure and mechanical properties of WNx/TiSiN multilayer was studied in detail. The multilayers and monolayers were fabricated on high-speed steel substrates by unbalanced direct magnetron sputtering from W (purity 99.95 %) and Ti80Si20 (purity 99.50 %) targets. The chemical composition and the cross-sectional morphology of multilayer and single-layer coatings were characterized by scanning electron microscopy (SEM) equipped with wave-dispersive X-ray spectroscopy (WDS). The structure was analyzed by X-ray diffraction (XRD). The hardness and Young’s modulus of multilayer and coatings were investigated using the nanoindentation method. Results showed that the WNx/TiSiN multilayer, possessing cubic W and TiN phases and a dense layered microstructure, showed slightly improved hardness (28.5 ± 3.5 GPa) and HIT/EIT parameter (0.087), as compared with the WNx and TiSiN coatings. It has been shown that the design of multilayered structure of WNx/TiSiN coating is a promising way to tailor the microstructure and properties of the hard coatings.
Titanium-doped LiAlO2 ceramics for neutron scintillation
Authors: Thoř T , Rubešová K , Jakeš V , Kučerková R , Pejchal J , Nikl M
Published: December 2022

A series of bulk ceramic samples of titanium-doped LiAlO2 with doping concentrations of 0.05, 0.1, 0.5 and 1.0 at% were prepared using a sol-gel method. The LiAlO2:Ti samples showed emission in two spectral regions around 380 and 765 nm associated with the CT transition of Ti4+ and the d-d transition of Fe3+ impurities, respectively. The sample composition with 0.5 at% doping concentration exhibited the highest emission intensity. Furthermore, dense ceramic samples with 0.5 at% Ti-doping were prepared using spark plasma sintering. These samples exhibited intense CT luminescence of Ti4+ at 380 nm with a decay time of approximately 2.3 μs, while the emission of Fe3+ impurities was mostly suppressed.
Effect of CO2 concentration on the kinetics of the hydralloy C5
Authors: Tóth L , Brestovič T , Lázár M , Jasminská N , Dobáková R
Published: December 2022

The article discusses the effect of a high concentration of CO2 on the kinetics of the hydrogen absorption and desorption process in the metal hydride alloy Hydralloy C5, on which research is being carried out on the ability of the metal hydride (MH) alloy to separate hydrogen from unwanted synthesis gas components. The focus is on the contamination of the alloy by the carbon dioxide, which is the main gas found in the mixture of unwanted gases after SYNGAS has been modified to increase the percentage of hydrogen in the gas mixture. Carbon dioxide, as a significant oxidant, significantly affects the kinetics of the selected metal hydride alloy. With the increasing percentage representation of the given gas in the mixture with hydrogen, the rate of deterioration of the alloy’s properties increases. The process of contamination of the alloy with carbon dioxide occurs by its decomposition into carbon monoxide and oxygen and subsequent oxidation of the surface layers of the alloy grains, which prevents or significantly degrades the passage of hydrogen into the structure of the metal hydride alloy.
Multi-objective optimization of various type finned heat sink with phase change materials (PCM)
Authors: Selvan N Muthamil , G Trilok , Gnanasekaran N
Published: December 2022

The paper focuses on optimizing hybrid PCM filled heat sinks with a multi-objective approach. In the current study, the fins are oriented both horizontally at the sidewalls and vertically at the bottom side in the enclosure. Two heat sinks with different types of fin shapes are introduced in the enclosure. A rectangular shape finned heat sink, and a tapered shape finned heat sink is incorporated in both sidewalls and bottom walls. The study’s main goal is to optimize the PCM-based heat sink to prolong the charging cycle (melting) and shorten the discharging cycle (solidification). The PCM used in the study is n-eicosane, and the material for the heat sink is aluminum. A heat flux with constant supply of 2000 W/m2 is provided at the enclosure bottom, and the remaining walls are insulated. A 2-D numerical simulation is done using the commercial software ANSYS Fluent. The multi-objective optimization is carried out using the technique for order preference by similarity to ideal solution (TOPSIS) optimization technique. For a constant PCM volume for both the cases, fin spacing, fin positioning, and fin heights are varied. The output results determined the optimum configuration for the stretched melting period and minimized solidification period.
Swamp Water Parameter Dynamics Induced by Rainfall and Tides in Dadahup Irrigation Area, Kalimantan
Authors: Zevri A. , Rahardjo A. P. , Legono D.
Published: December 2022

This study aims to understand the flow and water quality behaviour in response to the combination of rainfall and tides in the Dadahup Irrigation Area. Rainfall and tides have a strong influence on the Dadahup Irrigation Area. The impact of floods and droughts which hit the area in recent years changed its water quality because of salinity intrusion and the presence of pyrite in the irrigation area. The existing gates and levees along the main primary channel cannot fully regulate the water level on the other channels and on the paddy fields. This condition has resulted in crop failure in several places. Parameters of flow and water quality data such as rainfall, water level, pH, and salinity were measured from an newly installed telemetric monitoring system. A sampling period was selected in which both rainy and dry conditions were present. In that period, tides also oscillated the water level. Hydraulic simulations will analyze the hydrodynamic condition along with the observation results and will describe the flow profile and water quality changes. Simulations show that a high-intensity rainfall can immediately raise water levels in the main primary channel, and it impacts increasing pH and decreasing salinity.
Bibliometric Analysis of Change Management and Readiness to Explain The Adoption of Sustainable Public Procurement
Authors: Marita Leny , Safrizal H B A , Andriani N , Masrurotin M
Published: December 2022

How to advance the adoption of Sustainable Public Procurement (SPP)? This issue is not fully apprehended yet. This bibliometric analysis investigates the variables related to SPP adoption from the Change Management (CM) and Change Readiness (CR) perspective, correspondingly mapping the research themes emerging in this topic. The source articles search used a Systematic Literature Review (SLR) protocol referring to the PRISMA 2020 statement. We explore paper articles in the databases of Emerald, SAGE, Science Direct, Springer, Taylor & Francis, Wiley, MDPI, IOPscience, and ProQuest. Then We conducted clustering and in-depth analysis of co-occurrence keywords and terms used in the manuscript reviewed for mapping research themes and variables related to CM and CR to adopt SPP. The contribution of this review shows research themes that are currently emerging researched on the topic of CM and CR for the adoption of SPP based on the time distribution of each research themes cluster.
Artificial Intelligent For Rainfall Estimation In Tropical Region : A Survey
Authors: Mardyansyah R Y , Kurniawan B , Soekirno S , Nuryanto D E , Satria H
Published: December 2022

Rainfall monitoring in real-time is a mandatory in tropical areas such as Indonesia. As a country with various topographical conditions ranging from low-lying urban areas, highlands, to mountainous valleys, Indonesia is prone to hydrometeorological disasters in the form of flash floods and landslides. The strategic geographical position at the equator, between the Pacific and Indian oceans, and surrounded by vast oceans, combined with various natural phenomena related to the dynamics of the atmosphere and the ocean, makes high-density rainfall observations indispensable for both disaster mitigation and climate monitoring. As a vast tropical and archipelagic country, Indonesia currently has around 1000 automatic rainfall sensors and still requires more sensors to increase the spatial resolution of the observation network. Increasing the density of the observation network using both rain gauges and weather radar poses a problem of high operational costs. Therefore, several alternative rainfall observation systems are required. In the last decade, there have been several studies related to rainfall measurements using artificial intelligence from various meteorological variables, including the exploitation of microwave signals from radio telecommunications links, both terrestrial and satellite using high frequency bands. In this survey paper, we review and discuss research articles related to rainfall estimation using state-of-the-art methods in artificial intelligence using meteorological observation data, remote sensing, terrestrial and satellite microwave communication links. In conclusion, we present several future research challenges that can be applied to increase the density of rainfall observation networks.
Effect of pumakkal dose of coffee skin waste compost on mustard pagoda growth (brassica narinosa L.)
Authors: Sari Ni Wayan Indriyana , Zen Suharno , Sutanto Agus , Widowati Hening , Noor Rasuane
Published: December 2022

This study aims to determine the effect of variative doses of compost pumakkal fertilizer on the growth of Pagoda mustard (Brassica narinosa L.) and determine the most significant dose variation on the growth of growth. This is experimental research using a completely randomized design (CRD). This study used 1 control 3 treatments with 8 replications for 40 days. This study employed 32 pagoda mustard plants. The parameters observed in this study were the number of leaves and the wet weight of the mustard (grams). The data were analyzed using the one-way ANOVA technique. It is concluded that the ANOVA analysis test results showed Fhit > Fdaf, meaning that the administration of various doses of pumakkal fertilizer for coffee husk compost in each treatment had a significant effect on the growth of the entire leaves and the wet weight of the pagoda mustard plants. The BNJ further test stated that the best growth in the number of leaves and wet weight of pagoda mustard was in the P3 treatment, namely by giving 125 grams of pumakkal fertilizer of coffee husk waste compost to the pagoda mustard greens.
Using the IPCC Formula to Calculate CO2 Emissions from Everyday Motorized Vehicles as the Baseline for Climate Change Mitigation Policies
Authors: Angin Ria , Irawati  , Setyaningtyas Rusdiana , Adawiyah Putri Robiatul
Published: December 2022

Climate change has attracted the attentions of every nation on earth, including Indonesia. Indonesia’s commitment to minimize greenhouse gas emissions through the ratification of the Kyoto decree in Law no. 17 / 2004. Other regulations for the National Action Plan for Reducing Carbon dioxide are regulated in Presidential Regulation No. 61/2011 and No. 7/2021 for the National Greenhouse Gas Inventory. The East Java provincial government adopted this policy through East Java’s Province Regulation No. 67/2012. This article predicted an increase in carbon dioxide from the daily vehicles. The study will be done in Jember, a third city in East Java Province. Data is calculated using IPCC formula. The secondary data from 2018 to 2020 was analyzed, as well as predictions for 2030. The number of motorized vehicles growth is 4.5% each year. CO2 emissions from the daily transportation sector will reach 3,846,049.49 tons in 2030. Motorcycles contribute 2,055,244.87 tons. CO2 gas emissions from the 8 main streets of the Jember Gold Triangle are 62,190.52 tons.
Technology Dissemination of Backyard Farming for Supporting Food Security in Palu Central Sulawesi
Authors: Rahayu H S P , Dalapati A , Dewi Mardiana , Herawati  , Amalia A F
Published: December 2022

The optimally of the backyard provide enormous benefits to support the nutritional needs of the family. It is one of strategies in gaining food security in the household and supporting the environment sustainability. The study was conducted in Palu Central Sulawesi in October 2021 as an evaluation survey of the technology dissemination for backyard optimization. The data were analyzed by Expected Food Pattern and scoring method for transferred technologies. The result shown that the technology dissemination increase the Food Pattern Expectation score from 74.2 to 78.0 and increase the family income up to 23%. The technologies’s implementation score consist of 20% in vertical farming, 27% in soil block nursery, 27% in the composition of planting media, 33% in nature pesticide, 27% in MOL production, and 20% in household waste composting. To increase the technology adoption, an assistance for the groups as a model and deployment for larger target are needed.
Study on plasma cleaning of surface contaminants on pure copper
Authors: Yi Chen Xi , Wang Shuai Kang , XU Xue Bo , Tian Ye Fei , Bao Ming Dong
Published: December 2022

To demonstrate the relationship between the type of working gas and the efficiency of plasma cleaning, the kinetic energy of the incident ions was controlled by adjusting the bias, and the effect of different ion sources on the sputtering yield under the same bias was compared. The plasma flow generated by glow discharge was used to clean the sample surface to evaluate the plasma cleaning efficiency. Scanning electron microscope (SEM), x-ray photoelectron spectroscopy (XPS), x-ray Powder Diffraction (XRD), Ultraviolet-visible Spectrophotometer (UV), and Surface Profiler were used to characterize the surface morphology, element types, phase composition, specular reflectance, and three-dimensional (3D) morphology before and after plasma cleaning. The results show that the sputtering yield increases with the increase of bias, and when the bias value is lower than 400 V, the mass of the samples has almost no change before and after cleaning. It takes more energy to remove the surface oxide than the pure metal copper. The results also show that argon plasma has a better effect on removing pollutants on the sample surface than nitrogen plasma. However, a long time of plasma cleaning is often accompanied by re-deposition. The changes in copper reflectance induced by plasma cleaning are also discussed.
Prediction models of the ionization coefficient and ionization cross-section based on multi-layer molecular parameters
Authors: QIU Rui , ZHOU Wenjun , ZHENG Yu , HOU Hua , WANG Baoshan
Published: December 2022

Prediction models were proposed to estimate the reduced Townsend ionization coefficient and ionization cross-section. A shape function of the reduced Townsend ionization coefficient curves was derived from the ionization collision probability model. The function had three parameters: the first ionization potential energy, A

α
, and B

α
. A

α
and B

α
were related to the molecule symmetry and size. The polarization of molecules could characterize the molecule symmetry. The multi-layer molecular cross-section (MMCS) was proposed to describe the contributions of electrons and molecule radius on different molecule surfaces to collisions. A prediction model of the ionization cross-section was also proposed based on A

α
. The molecule parameters were calculated by the Becke3–Lee–Yang–Parr (B3LYP) method and the 6–311G** basis set. We used available data of 30 and 23 gases, respectively, to build the prediction models of reduced Townsend ionization coefficients and ionization cross-sections. The relationships between the molecular parameters A

α
and B

α
and the ionization cross-section were built up via nonlinear fittings. The determination coefficients R
2 of A

α
, B

α
, and the ionization cross-section were 0.877, 0.887, and 0.838, respectively. The results showed that the accuracy of models was positively correlated with the molecule symmetry and reduced electric field. This was mainly related to the accuracy of the MMCS model in predicting A

α
. The MMCS model needed to be improved to describe the collision direction selectivity caused by the molecule asymmetry. Under a high reduced electric field, that error of A

α
had less influence on the prediction results. However, the prediction results for single atoms with high symmetry were poor. This may be due to the absolute error of the model close to single atoms’ reduced Townsend ionization coefficients. The models could provide the basis for gas insulation prediction and discharge calculations, especially for symmetric molecules under a high electric field.
Asymptotic smoothness in Banach spaces, three-space properties and applications
Authors: Causey R. , Fovelle A. , Lancien G.
Published: December 2022

We study four asymptotic smoothness properties of Banach spaces, denoted

T

p

,

A

p

,

N

p

\mathsf {T}_p,\mathsf {A}_p, \mathsf {N}_p

, and

P

p

\mathsf {P}_p

. We complete their description by proving the missing renorming characterization for

A

p

\mathsf {A}_p

. We show that asymptotic uniform flattenability (property

T

∞

\mathsf {T}_\infty

) and summable Szlenk index (property

A

∞

\mathsf {A}_\infty

) are three-space properties. Combined with the positive results of the first-named author, Draga, and Kochanek, and with the counterexamples we provide, this completely solves the three-space problem for this family of properties. We also derive from our characterizations of

A

p

\mathsf {A}_p

and

N

p

\mathsf {N}_p

in terms of equivalent renormings, new coarse Lipschitz rigidity results for these classes.
Protamine-derived peptide RPR (Arg-Pro-Arg) ameliorates oleic acid-induced lipogenesis via the PepT1 pathway in HepG2 cells
Authors: Mijiti Maihemuti , Mori Ryosuke , Nakashima Yuga , Banno Arata , Ye Yuyang , Takeuchi Asahi , Matsuba Shoya , Kiriyama Keisuke , Sutoh Keita , Nagaoka Satoshi
Published: December 2022

The protamine-derived peptide arginine-proline-arginine (RPR) can ameliorate lifestyle-related diseases such as obesity and hypercholesterolemia. Thus, we hypothesized that the hypolipidemic activity of RPR could attenuate events leading to non-alcoholic fatty liver disease. Addition of 2 m m oleic acid (OA) to the culture medium induced fatty liver conditions in HepG2 cells. The OA + RPR group showed significantly decreased cellular or medium triglyceride (TG) level compared with the OA group. Stearoyl-CoA desaturase-1 (SCD1) or sterol regulatory element-binding protein 1 (SREBP1) protein level was significantly lower in the OA + RPR group than in the OA group. In the R + P + R amino acid mixture-treated group, the TG level was not significantly different from that in the OA-treated group. The OA + RP- or OA + PR-treated groups showed significantly decreased cellular TG level compared with the OA group. Moreover, the effect of RPR disappeared when the peptide transporter 1 (PepT1) was knocked down with a siRNA. Collectively, our results demonstrated that RPR effectively ameliorated hepatic steatosis in HepG2 cells via the PepT1 pathway.