bluuebunny/crossref_metadata_2025 huggingface dataset:
An Improved PPO for Multiple Unmanned Aerial Vehicles
Authors: Bai Xue , Lu Chengxuan , Bao Qihao , Zhu Shansheng , Xia Shaojie
Published: February 2021

In recent years, multi-agent reinforcement learning (MARL) has been applied widely, especially in large multi-role games such as StarCraft and unmanned aerial vehicles (UAVs) combat simulations. However, MARL is faced with challenges regarding fast convergence and efficient cooperation. In a multi-agent scenario, on the one hand, when a fully centralized network model is adopted, it is difficult for the model to converge due to the huge action space; on the other hand, it is difficult for a decentralized model to cooperate and achieve global optimization. To jointly control multiple agents, we propose an improved PPO algorithm by combining a centralized network and decentralized networks. Our method not only reduces the action space and accelerates the convergence, but also introduces more diversity for agents’ decision-making.
Tor Hidden Services Discovery and Analysis: A Literature Survey
Authors: Bian Jingjing , Cao Chunjie , Wang Longjuan , Ye Jun , Zhao Yan , Tang Chaosheng
Published: February 2021

Hidden services are a feature of Tor(The Onion Router)[1]. It provides anonymity for the service requester while maintaining the anonymity of the service provider. Since it is quite difficult to trace back and locate both parties in the communication, the criminals use hidden services mechanisms to construct various illegal activities in the darknet, which has brought adverse effects to society. In order to prevent the abuse of Tor hidden services, the discovery and analysis of hidden services are particularly important. The aim of this survey paper is to review and compare the literature of the past five years, provide the readers with methods for discovering tor hidden services, along with the various content analysis methods developed and proposed from time to time. we explain their key ideas and show their interrelations.
A Limited IST and Random Uniform Clustering Algorithm
Authors: Liang Ping Yuan , Jiang Jun , Tao Fusheng
Published: February 2021

In order to solve the problems of unbalanced energy consumption and shortened network lifetime caused by the uneven distribution of cluster heads (CHs)in wireless sensor networks, a Limited IST and Random Uniform Clustering Algorithm (LIRUCA) is proposed. The algorithm comprehensively considers the energy of nodes, the distance to the sink, and the correlation between nodes when selecting CHs, and limits the intra-cluster communication distance, thus improving the uniformity of CH distribution. Compared with LEACH, EBCRP, and LEACH-improved protocols, results of simulation experiments show that the LIRUCA algorithm can effectively improve the uniformity of clustering, reduce the energy consumption, and prolong the network lifetime.
Research on MAC Verification Code of Railway Signal Security Communication Protocol
Authors: Wu Puwei , Wu Zhongdong , Li Liyun
Published: February 2021

Aiming at the low security and low real-time performance of the message authentication security layer (MASL) message authentication code (MAC) algorithm in the railway signal security communication protocol RSS-II, the advanced encryption standard AES is used as the core algorithm of the MAC code and the ciphertext is used Packet link encryption and decryption of the message, simulation of the security protocol from the security-related key service process of the RSSP-II communication protocol, verification of the confidentiality of the improved protocol, and optimization of the protocol key service process, that is, the key The center uses the advanced encryption standard AES algorithm to authenticate the vehicle equipment and the ground wireless block center, further strengthening the security of the protocol.
A Framework for Interactive Online 3D Visualization of Electric Information
Authors: Li Yan , Zhang Hong , Zhang QianQian
Published: February 2021

To manage the electric network effectively, 3D visualization framework is necessary to reveal the complexity of power grid system. In this paper, an interactive online 3D visualization framework is proposed to visualize the electric network related information from power station to the static data of the system. We applied Cesium, an open source platform for 3D visualization based on WebGL supported browsers. Meanwhile, multiple Level of Detail (LoD) structure of power grid facility is generated to improve the speed of 3D model loading and rendering. The experimental results indicate that the proposed framework can integrate and dynamic visualize power grid information from multiple sources. The multiple LoD structure can reduce the model loading time by 76% and increase the FPS over 50% according to the tests on sample data.
An Energy-optimized Algorithm for the Data Packet Transmission with Circuit Power Consumption
Authors: Zhang Zihan , Meng Chao , Du Yunhai , Zhang Chenxi , Ding Wenjing
Published: February 2021

The development of 5G communication and Internet of Things (IoT) technology has brought massive data transmission. This paper considers a first-in-first-out packet data transmission scenario with actual circuit power consumption and proposes a data transmission strategy with optimal energy efficiency. Specifically, the proposed algorithm in this paper uses a double-layer iteration algorithm, then compare and replace the optimal solution of the ideal circuit power consumption with the optimal solution of the actual circuit power consumption. The numerical results show that our proposed algorithm can significantly reduce energy consumption.
A Data Reconciliation Model Based on Turbo for Satellite-Ground Quantum Key Distribution Network
Authors: Zhou Wenting , Liu Jie , Feng Bao , Ye Xiao , Zhang Tianbing , Bian Yuxiang
Published: February 2021

In the satellite-ground quantum key distribution network with power IoT, due to the imperfection of the quantum equipment and the noise in the channel, the raw key will have some bit error rate and cannot be used for secure communications. To solve this problem, we propose an improved data reconciliation model based on Turbo for satellite-ground quantum key distribution to extract the raw key, and then the key on both sides of communication are identical. We carry on the optimization and simulation to Turbo and increases its error correction efficiency by 15%. To test and verify the feasibility of the model, we implement satellite-ground quantum key distribution simulation experiments and respectively use the low-density parity check (LDPC), Cascade, and Turbo for data reconciliation. Experimental results show that Turbo can make the final key generation increased by 8% comparing with LDPC and Cascade.
A Massive Laser Point Cloud Data Organization Strategy Based on the Mixed Model
Authors: Wang Yingying , Zhang Yuye , Wang Shangqiang , Ji Xiaojia
Published: February 2021

In the process of data interaction, neighborhood query, filtering, visualization, and dynamic update of LiDAR point cloud data, how to efficiently organize and process massive point cloud data, and quickly index and locate any point in the point cloud and its neighborhood Search is a key issue to be solved urgently. In this paper, combining the advantages of a virtual grid with no interpolation loss on original data, sT spatial relationship, and low memory occupation of the octree, we design an index method based on the combination of virtual grid and adaptive octree based on dynamic scheduling of internal and external memory. Realize the organization and scheduling of massive LiDAR laser scanning point cloud data.
Research and Realization on Smart City Applications Based on eMTC wireless communication technology
Authors: Xu Kang , Liu Junjun , Lu Jixiang
Published: February 2021

In response to the call of strengthening the construction of the ubiquitous electric power Internet of Things by the State Grid Corporation, combining the urgent requirement in the construction of smart cities, this paper researched the application of wireless communication technology on smart street lamps based enhanced machine type communication (eMTC) technology. Based on this research, a kind of single-lamp controller PEC6403 based on eMTC wireless communication technology was developed. In order to realize remote control of the lamp, run data sampling in real-time and malfunction alarm, the TCP long connection established by the remote management platform and the eMTC wireless communication module was used to receive and send a message by this single-lamp controller. At last, this paper did some experiments to certificate the high communication rate, low latency, and low power consumption of this eMTC wireless communication module. Finally, this paper analyzed the problems existing in the large-scale promotion in the field of electricity application of the product and put forward the prospect of eMTC technology application in the electric field in the future.
RRPOT: A Record and Replay Based Honeypot System
Authors: Du Chunlai , Zhao Shichuan , Wang Wei
Published: February 2021

The honeypot system is a critical defense facility in cybersecurity. It captures and analyzes the attack behavior for constructing a more robust defense system. However, considering the overhead caused by analysis, the system cannot support fine-grained analysis. This paper proposes RRPOT, a novel honeypot system based on the record and replay (RnR) framework of virtual machine (VM). By combining the native honeypot system with an RnR framework, the system supports to postpone the time-consuming analysis to the replay stage, thereby enables fine-grained analysis. Moreover, we propose an on-demand record mechanism to reduce performance and storage costs during the record stage and employ an on-demand replay mechanism to improve replay efficiency. Leveraging these approaches, we develop a flexible and efficient honeypot system, and it was proven useful in the practical scenario.
Principle and Simulation PID Controller of Liquid Level System
Authors: Chen Lijie
Published: February 2021

Three-tank water tank is one of the most extensively used and representative industrial mathematical models, which has very important research significance. Liquid level control is one out of a multitude of useful used means in industrial check on. Due to the influence of factors such as the friction of the liquid itself, the control object has certain hysteresis and nonlinear characteristics. PID control is one of the most wide-ranging applied control algorithms and its wide operating range and simple function. In this paper, the modeling and simulation of representative three-tank PID and the traditional PID control and fuzzy PID control are compared and summarized.
Research on Equipment Procurement Contract Performance Evaluation
Authors: Yuan Mingxing , Peng Xinran , Li Xiaosong
Published: February 2021

The equipment procurement contract performance evaluation is an important means to effectively solve the problem like “inefficient progress”, “low targets”, and “increased costs” in equipment procurement. This paper defined the concept and connotation of the performance of equipment procurement contract, and proposed the equipment procurement contract performance evaluation, including influence factors analysis, evaluation indicators establishment, evaluation model construction, calculating results, etc., constructed four-dimension equipment procurement contract performance evaluation indicator system consisting of quality, schedule, funding, and service, and constructed the equipment procurement contract performance evaluation model based on BP neural network, and carried out a case analysis. The research conclusions provide a reference for the evaluation practices of equipment procurement contract performance.
Research on ECD Distribution Law under Managed Pressure
Authors: Xiao Fan , Guan Zhichuan , Pan Rui , Li Pengfei , Han Chao , Hu Sicheng
Published: February 2021

By analyzing the basic theories and technical principles of managed pressure drilling, this paper establishes the cyclic pressure loss check and ECD calculation model under managed pressure conditions. The model is used to calculate and analyze the distribution of equivalent density curves in the wellbore under different drilling fluid densities and different pressure control conditions, and to analyze the distribution of ECD curves in pressure profiles at the same depth. Analyze the density range of the safe use of drilling fluid.
Research on the Security Technology of Federated Learning Privacy Preserving
Authors: Mao Juan , Cao Chunjie , Wang LongJuan , Ye Jun , Zhong WenJie
Published: February 2021

With the emergence of data islands and the popular awareness of privacy, federated learning, as an emerging data sharing and exchange model, can realize multi-party collaboration under the premise of protecting data privacy and security because the data distributed in multiple devices cannot be sent locally. To achieve benefits for all parties involved, it has been widely used in many fields such as finance, medical care, and education. However, FL also has various security and privacy issues. Starting from the overview of federated learning, this article describes in detail the threat model and existing security issues, including replay attacks, poisoning attacks, reasoning attacks, etc., and then makes a certain analysis of FL privacy protection security technologies. Compared with SMC and HE, differential privacy is excellent in terms of efficiency. Finally, we discussed the challenges of privacy protection and security issues and future research directions.
A Virtual Simulation Experiment System for Requirement Analysis
Authors: Peng Yuyi , He Xinyu , Huang Yiqi
Published: February 2021

The application of virtual simulation technology promotes the reform of experimental teaching methods in colleges and universities to provide reliable support for cultivating students’ professional engineering application ability and improve the overall quality of talent training. Based on real projects, this virtual simulation experiment project adopts the trinity teaching method of ‘virtual environment, actual problems, real ability’. And it makes full use of natural language processing and other AI technology and software technology to provide students with requirement analysis experiments that are very close to reality. The practical environment has played a multifaceted effect and solved the students’ neglect of the importance of requirement analysis.
A Novel Think Tanks Evaluation System Based on Micro Service
Authors: Xiong Shiyong , Huang Benguo
Published: February 2021

With the development of new technology, the traditional single application architecture has been unable to meet a variety of needs of the existing system, in order to solve the inconvenience monomer architecture system maintenance, a series of problems such as poor extensibility, deployment of trouble, micro service architecture is to break up the system, each service function is simple, can complete the function of single responsibility, and deploy alone, without centralized management, a service outage will not affect other service work, reduce the coupling between modules, the system performance improvement. Therefore, micro-service architecture is adopted to develop a new think tank evaluation system. In response to the needs of local think tank evaluation, this paper designs a new think tank evaluation system based on micro-service. The system adopts micro-service architecture to design and develop, and splits the services according to the business of the system. The system was divided into basic service, registration service, audit service, declaration service, review service, scoring service and log service. The communication between the services was realized through RPC remote invocation based on Dubbo distributed framework and Zookeeper distributed application. The system realizes the separation of front and rear ends, each service of the server is implemented with Spring Boot framework, the front end is implemented with vue.js framework, the system use Mysql database, and Redis is used to improve the system performance
Investigation of polymer materials properties to use for additive manufacturing
Authors: Anokhin A , Strelnikova S , Ermakova E , Chuvikina M , Potyomkina E , Fefelov M
Published: February 2021

The paper focuses on properties of polymers to produce core-shell ceramic powders (Al2O3, TiC, ZrO2-Y2O3, TiB2, SiO2, SiC, ZrB2, Si3N4, TiN, B4C) and to set selective laser sintering (SLS) parameters to make ceramic prototypes with complex shape and bionic design. Polymer materials: polyvinyl alcohol (PVOH) grades V, 8/1, 16/1; polyvinyl acetate (PVAc) grades M10 and M100; polyamide (PA) grades 12 carbon, 6/66/610 - 1, 6/66 - 4, 54/10 (6/66 - 1), polystyrene (PS) grades 525M and 825M were investigated to determine glass transition temperature (T
g
), melting (T
m
) and crystallization (T
cr
) points, as well as thermal effects in nitrogen, argon and air. Polymers were heated to temperature comparable to the melting point with step of 5 °C/min and were cooled to 20 °C with differential scanning calorimeter (DSC).
The problems associated with monitoring of main parameters of working areas and technological environments in high technology industry
Authors: Belenkii D I , Magomedov T M
Published: February 2021

The first part of the article describes the regulatory requirements related to the control of the main parameters of working areas and technological environments in high technology manufacturing: number concentration of aerosol particles and cleanrooms classification, mass concentration of aerosol particles in the premises and means for its control, number concentration of particles in liquid media and methods of its control.

In the second part of the article, the trend of deterioration of the technical condition of the existing measuring instruments for disperse parameters of aerosols, suspensions and powder materials is described.

In conclusion, it is proposed to create service and calibration centers for measuring instruments maintenance, as well as shared-use equipment centers based on national metrological organizations.
Functional materials under elasto-plastic deformation
Authors: Brovman T V
Published: February 2021

A theoretical study of the factors affecting the workpiece accuracy under conditions of local plastic deformation has been carried out. The study has shown that when a two-support workpiece is bent by the force applied in the center along its length, plastic deformation occurs only at 1/3 of its length, and 2/3 remains under the elastic deformation. The paper analyzes the technologies and features of transient local plastic deformation, the factors influencing geometry fidelity are determined. The author gives the load function values under which the elastic deformation occurs as well as the carrying capacity loss load for the ideally plastic material unhardened. The function for calculating the values of elastic and plastic deformation zones is determined, which makes it possible to eliminate the need for additional calculations of the plastic deformation zone boundaries.
The influence of multiple phase transformations on functional characteristics in TiNi alloys in various structural states
Authors: Churakova A A , Gunderov D V , Kayumova E M
Published: February 2021

The article were discussed the effect of multiple martensitic transformations with a different number of cycles on the functional characteristics, microstructure and mechanical properties of the TiNi alloys in different structural states and chemical compositions. As a result of multiple martensitic transformations, the accumulation of defects and a decrease in the size of structural elements are observed. The most effective phase hardening is in an equiatomic alloy. The Ti49.8Ni50.2 alloy demonstrates stability to phase hardening in all studied states.
Influence of laser radiation on carbon nanotubes for the formation of frame materials in bioelectronics
Authors: Yu Gerasimenko A
Published: February 2021

Single-walled carbon nanotubes (SWCNT) nanoframes have been created in the form of structured films on a silicon substrate as well as in the bulk of biopolymers of albumin, collagen, and chitosan. Biopolymers were required to create multilayer, electrically conductive bioelectronic structures for reconstructing the layers of the heart. For this, a laser setup was used based on a pulsed fiber ytterbium laser with a wavelength of 1064 nm and a scanning system. Liquid dispersions of SWCNT in ethanol and aqueous dispersions of biopolymers were applied onto a substrate by layer spraying. Then they were irradiated with laser radiation. The effect of the binding of SWCNTs and their bundles to each other under the action of laser radiation on a silicon substrate is demonstrated. Using SEM and TEM, the formation of “T”, “X” and “Y” shaped joints in films is demonstrated. The mechanical characteristics of structured films by laser have improved. The hardness of films with nanoframe after laser exposure increases more than 6 times compared to the original SWCNT film. The specific electrical conductivity of films with nanoframe after laser exposure increases more than 7 times. The specific electrical conductivity of nanoframe in biopolymer matrices varies in the range 0.6 - 12.4 S/m, depending on the type of biopolymer. These values exceed electrical conductivity of heart myocardium. The highest roughness is shown for the lower layer of chitosan and SWCNT, and the smallest for the upper layer of albumin and SWCNT of the bioelectronic structure. Using confocal microscopy, the possibility of the formation of a cellular structure under the action of laser radiation on an aqueous biopolymer dispersion of SWCNT has been demonstrated. The cellular structure, electrical conductivity and nanoframe from SWCNT promoted better vital functions of heart cells - cardiomyocytes.
Low-temperature processing of Ti-Ni shape memory alloy by E.C.A.P. in shells
Authors: Karelin R D , Yu Khmelevskaya I , Komarov V S , Kosyachkova T R , Andreev V A , Perkas M M , Yusupov V S , Prokoshkin S D
Published: February 2021

The possibility of Ti-50.1 at.% Ni SMA processing by the equal-channel angular pressing (ECAP) in core-shell mode at low deformation temperatures was studied in the present work. The ECAP was performed in steel and iron shells in a temperature range from room temperature to 350 °C. Ti-Ni samples with a diameter of 12 mm were successfully subjected to ECAP for one pass at 200 °C in iron shell with a diameter of 20 mm. Lowering of the deformation temperature both to the 100 °C and to the room temperature leads to the samples distraction during the first ECAP pass. Significant deformation hardening of the sample after one pass of the ECAP in core-shell mode at 200 °C is observed. Increase of the structure defectiveness confirmed by the noticeable broadening of forward (from 26 to 103 °C) and reverse (from 20 to 46 °C) martensitic transformations hysteresis. Values of hardness, dislocation yield stress, and ultimate tensile strength after one pass of the ECAP in core-shell mode at 200 °C equals respectively, 275 HV, 1045 and 1200 MPa, that is noticeably higher than the same properties after reference treatment (annealing at 750 °C, 30 min): 176 HV, 520 and 945 MPa.
Production of porous films of silicate glass using a plasma focus setup
Authors: Kolokoltsev V N , Borovitskaya I V , Ya Nikulin V , Silin P V
Published: February 2021

The aim of the work was to obtain and study films of porous silicate glass. The proposed method for producing porous films is based on the rapid cooling of the melt on the surface of a glass plate after exposure to short pulses of argon plasma generated on an electrodischarge installation of plasma focus type. Silicate glass films obtained by such method have the properties of both porous glasses and foam glass. The specific volume density of these films is ∼ 0.4 g/cm3, their porosity and hygroscopicity correspondingly ∼ 0.3 and ∼ 30%
Hydride technologies in porous metals production
Authors: Kuznetsov A A , Anfilov N V , Berezhko P G , Yaroshenko V V , Yu Postnikov A , Tsarev M V , Mokrushin V V , Kremzukov I K , Ivanov D G , Zabavin E V , Sisyaev A V , Polovinkin P E , Simanov V A , Solomonov A V , Tsareva I A , Malkov I L
Published: February 2021

The experience of RFNC–VNIIEF in application of hydride technologies in porous metals production is presented. Using metal hydrides as pore-forming agents for foaming of metal melts, as raw materials for obtaining porous samples by sintering of powder compacts and as intermediate products in processes of hydride grinding of metals for further sintering of compacts are considered.
Effect of particle size distribution on the structure and mechanical properties in the process of laser powder bed fusion
Authors: Kuznetsov P A , Shakirov I V , Zukov A S , Bobyr’ V V , Starytsin M V
Published: February 2021

The paper studies effects of particle size distribution on the structure and mechanical properties of monolithic samples obtained by L-PBF. A powder of 321 austenitic stainless steel of one batch was divided into three fractions 0–20, 20–40, and 0–40 μm. It was established that for narrow fractional powder composition, hardness anisotropy is observed that depends on the building direction, whereas for wide fractional powder composition, hardness anisotropy is practically absent. It was found that the particle size composition of AISI 321 steel powder does not fundamentally affect the morphology of the grain structure. Despite the general preferred orientation of the {101} planes, a weak effect of the powder composition on the crystallites orientation is observed.
Binderless tungsten carbides with an increased oxygen content obtained by spark plasma sintering
Authors: Lantsev E A , Malekhonova N V , Chuvil`deev V N , Nokhrin A V , Blagoveshchenskii Y V , Isaeva N V , Boldin M S , Andreev P V , Smetanina K E
Published: February 2021

The features of spark plasma sintering (SPS) of plasma-chemical nanopowders with an increased oxygen content are investigated. It is shown that the process of shrinkage of nanopowders during SPS is limited by the rate of grain-boundary diffusion with anomalously low values of the activation energy. It has been established that a decrease in the activation energy of SPS may be due to the effect of oxygen on the diffusion permeability of grain boundaries of tungsten carbide at the stage of intense compaction, as well as anomalous grain growth at the stage of high-temperature sintering. The SPS kinetics of WC-W2C-WO3-W nanopowder compositions at the stage of intensive compaction is controlled by the rate of sintering of oxide particles with their simultaneous transformation into W2C particles, and then, at the stage of high-temperature sintering, by the process of plastic flow of W2C particles in the presence of tungsten particles. Ceramic samples with high density (98-99%), ultrafine-grained structure (average grain size less than 0.3 μm), having increased hardness were obtained by the SPS method. Hv = 30.5 GPa at Palmquist crack resistance ∼ 6.5 MPa · m1/2.
Hydrogen permeability and catalytic characteristics of a palladium-silver membrane with a modified surface
Authors: Petriev I
Published: February 2021

Thin films of Pd-23% Ag modified with nanostructured highly dispersed palladium by the method of electrolytic deposition have been obtained by magnetron sputtering. Electrochemical studies have demonstrated that the modified Pd-23% Ag film shows a high peak current (up to 2.15 µA cm−2) and excellent electrocatalytic activity in relation to the methanol oxidation reaction. The stability of the developed modified film is confirmed by the results of multi-scanning. Comparison of the hydrogen permeability has been demonstrated a significant increase in the hydrogen permeability of the modified membrane compared to the smooth one at an overpressure of 0.3 MPa. According to the approximation of the results obtained by a first-order line and calculations of the activation energy, which was 30.6 kJ mol−1, it can be concluded that the transport of hydrogen is limited by surface effects, namely chemisorption.
Development of methods of creation metal hydrogen permeation films
Authors: Pushankina P
Published: February 2021

The application of electrothermal and magnetron sputtering methods for manufacturing thin films containing palladium and silver is investigated. In the process of electrothermal sputtering, indirect heating of the evaporated material was used in a tungsten and tantalum boat, through which a current has been conducted and a direct heating of a thin plate of palladium alloy has been entailed by current. A composite target for magnetron sputtering of alloys using silver and palladium plates with different ratios of their areas has been developed. The dependence of the film composition on the target composition is determined. As a result of sputtering for 40 min, a sample with a thickness of 1.1 microns and a silver content of 23.2±0.7% was obtained from a target with an area ratio S(Ag)/S(Pd) = 20.8/79.2.
Structure and functional properties of rapidly quenched TiNiCu alloys with high copper contents
Authors: Shelyakov A V , Sitnikov N N , Borodako K A , Khabibullina I A , Dyadechko A A
Published: February 2021

Thin materials exhibiting the shape memory effect, with a narrow temperature hysteresis, are required to create miniature and high-speed devices. Quasi-binary intermetallic TiNi-TiCu alloys with high copper contents (more than 10 at %) demonstrate the reversible martensitic transformation with a small (4-6 K) hysteresis. Alloys of the TiNi–TiCu system with a copper content of 30–40 at.% were fabricated in an amorphous state by the planar flow casting technique at a melt cooling rate of 106K/s in the form of ribbons 30–50 μm thick. The alloy samples were subjected to dynamic crystallization using a single electric current pulse with duration of 5 ms. X-ray diffraction studies revealed almost fully martensitic state of the alloys with B19 structure at room temperature. TEM examination showed their structure to contain typical B19-martensite plates with a mean size of 20–80 nm. At the same time, the alloys exhibit a one-stage phase martensitic transformation B2↔B19 in the temperature range of (55÷75)°C, as well as pronounced shape memory effect, whose properties are largely determined by the structural parameters of the alloys.
Investigation of the influence of substrate materials on oxidation resistance of TaSi2 and Ta-Si-N coatings using SEM, EDS and GDOES methods
Authors: Sytchenko A D , Kiryukhantsev-Korneev Ph V
Published: February 2021

Coatings were obtained by magnetron sputtering of a Ta-Si target onto Al2O3, Mo, Si and Ni-based substrates. Samples were studied in terms of their structure, mechanical properties and oxidation resistance by SEM, EDS, nanoindentation and GDOES methods. It was found that an increase in the concentration of nitrogen leads to an increase in the hardness of coatings by 60%. The behavior of coatings and various types of substrates during annealing at a temperature of 1000-1200 ˚C.
Peculiarities of deformation of thin-sheet TRIP steel under static and fatigue loading
Authors: Prosvirnin D V , Kolmakov A G , Larionov M D , Pivovarchik S V
Published: February 2021

The features of the deformation of austenitic-martensitic thin-sheet TRIP steel under static and fatigue loading with varying parameters of the breaking rate as well as the maximum cycle stress under cyclic loading were studied. The ten-fold increase in the tensile rate led to the decrease in the ultimate strength by ≈ 6% and the relative elongation δ from 32% to 21%, which is due to a decrease in the intensity of the formation of deformation martensite. The nature of hardening during deformation of steel under static and repeated tension is almost the same. The effect of the greatest TRIP - strengthening under loading to the yield-point stress level and physical fatigue limit were found. Preliminary fatigue loading up to σmax = 1550 MPa with N = 3000 led to the increase in the yield strength and ultimate strength by ≈200 MPa and ≈100 MPa, respectively; the relative elongation decreased by a factor of 2.
Design and implementation of an Arduino-based instrument for parabolic motion
Authors: Sesa E , Labania H M D , Darwis D , Ismail M , Badaruddin  , Maskur  , Ulum M S
Published: February 2021

The lack of a physical instrument for determining the initial speed of experiment of the parabolic motion in the Department of Physics, Tadulako University, is one problem. In this research, we have been designed, implemented, and tested to show the initial velocity value of an Arduino-based to address this problem. The stages of this research began with the design and manufacture of mechanical systems, electronic systems such as power supply circuits and infrared detector circuits, motor stepper circuit, a series of servo motors, LCD circuits, and keypad circuits using the Arduino ATmega 2560 microcontroller. The next stage is making the test program and the main program. This tool has been tested and operated so that it gets good results. The initial measured speed is displayed on the LCD. The stability of measuring objects is excellent based on a low standard deviation between 0.02 - 0.06.
Synthesis and characterization of membrane from high molecular weight polyeugenol
Authors: Rahim E A , Fong R C Z , Sumarni N K
Published: February 2021

High molecular weight polyeugenol was synthesized by cationic polymerization, using the H2SO4-CH3COOH catalyst, and further characterized. Furthermore, the polymers were determined to be heterotactic using 1H measurement, while the membrane produced from a combination of PVC/DOP (32:38) and DOP was liquid, with polyeugenol alone generating solid. The result of Scanning Electron Microscopy (SEM) analysis indicates a pore size of 42.3 - 127 μm in polyeugenol membrane and the potential for application in the filtration of yeast cells, bacteria, and oil emulsions.
Application of zeolite intercalated calcium carbonate from pokea shell (Batissa violacea celebensis) waste as adsorbent Ni2+ ion
Authors: Mashuni  , Ahmad L O , Hamid F H , Sudarlin
Published: February 2021

The purpose of this study was to obtain adsorbent zeolite modified by CaCO3 from pokea shell (PS) waste to adsorb Ni2+ ions. Adsorbents are made through the intercalation method, where the PS powder is mixed to zeolites in 0.1 M HCl with 3 ratios of 3:1, 2:2 and 1:3 (g/g), respectively. The optimization of adsorption power was carried out by using parameters such as pH, contact time and concentration variation of Ni2+ ion solution. The analysis of the adsorption capacity and type of bond using the Freundlich and Langmuir isotherm equations. The characterization of the active site composition of the adsorbent was used FTIR instrument. FTIR spectra showed that CaCO3 modified zeolite adsorbent include Si-OH, O-H, Al-O, Si-O, C-H, Ca-C and C-O from CaCO3 and C-O from CO3
2-functional groups. The results showed that the best adsorbent was it with the zeolite-PS powder ratio of 3:1, the optimum conditions were obtained at pH 5, contact time at 60 minutes and 45 mg l−1 concentration. Adsorption of Ni2+ ions meets the Freundlich isothermal with adsorption capacity and energy of 1.33 mg g−1 and 5.78 kJ mol−1.
Analysis correlation sea surface temperature around North Maluku waters against rainfall in the City of Ternate
Authors: Alfiandy S , Hutauruk R C H , Adzim F
Published: February 2021

Sea Surface Temperature (SST) has a role in the process of rainfall has a role in an area with varying amounts to adjust the geographical location and topographic conditions in the region. The purpose of this study is to determine the connection of Sea Surface Temperature (SST) in North Maluku Waters to rainfall in the City of Ternate area. The method used in this study is Analysis Correlation Pearson and Spline Interpolation. The results obtained show that the Sea Surface Temperature (SST) in the North Maluku Waters have a low to moderate has a connection to rainfall in the City of Ternate area. When the Sea Surface Temperature in the North Maluku Waters region increases, the rainfall in the City of Ternate will also increase, conversely, if a Sea Surface Temperature in the North Maluku decreases, the rainfall in the City of Ternate will also decrease. The connection of Sea Surface Temperature (SST) to rainfall is in the low to moderate category, but it can already indicate that when Sea Surface Temperature (SST) in North Maluku Waters has an increased the rainfall in the City of Ternate region will also increase.
Comparison of Kernel regression model with a polynomial regression model on financial data
Authors: Nur’eni  , Fajri M , Astuti S
Published: February 2021

Regression analysis is constructed for determining the influence of independent variables on the dependent variable. It can be done by looking at the relationship between those variables. This task of approximating the mean function can be done essentially in two approaches, parametric and nonparametric approach. Kernel regression is one of the models with a nonparametric approach, and polynomial quadratic regression is one of the models with the parametric approach. This research aims to find the best model regression with compare to the model of kernel regression and model of polynomial quadratic regression in financial data usingRMSEcriterion. Share data that be used is Mastercard Incorporated (MA) with data periods 02 Januari 2019 until 31stDecember 2019. Research’s result indicated that for MA data, best model regression is kernel regression withRMSEvalue = 16,00147 andBandwidth (h) =25,64.
Variability of surface wind in Banda Sea and its correlation with El Niño and Southern Oscillation
Authors: Nanlohy P , Elake A Y , Andayany H , Kelkusa M
Published: February 2021

Variability of surface winds in the Banda Sea and its correlation to El Nino and Southern Oscillation (ENSO) have been clearly demonstrated using the European Center for Medium-Range Weather Forecasts (ECMWF) reanalysis data. Surface winds in the Banda Sea are affected by monsoons. When the northwest monsoon, the wind comes from the north and west to the southeast, while the southeast monsoon, the wind comes from the southeast to the northwest. ENSO changes the direction and speed of the wind during the west season, whereas it only changes the speed during the east season.
Effect of heating and electric conductivity of anthocyanin extract from red dragon fruit (Hylocereus polyrhizus) as a sensitizer material
Authors: Iqbal  , Basir Cyio M , Darwis D
Published: February 2021

Research on the Effect of Heating and Electrical Conductivity of Anthocyanin Extract from Red Dragon Fruit (Hylocereuz Polyrhizus) as a sensitizer has been conducted. Red dragon fruit (Hylocereuz polyrhizus) was macerated extracted with a solvent ratio of 1: 2. The absorbance was measured at a wavelength of 300 - 700 nm using a UV-Vis spectrometer with a dilution of 25 times. Extract stability test due to heating was carried out at temperatures of 40°C, 50 °C, 60 °C, 65 °C, 70 °C and 80 °C. The results showed that heating temperature causes a decrease of absorption, the sensitizer material of extract was unstable at high temperatures ranging from 70 °C and above, it was observed with the occurrence of color changes and the wavelength and absorbance were not measured. The electrical conductivity in bright conditions of the extract also decreased due to the effect of heating. Electrical conductivity in bright conditions Anthocyanin extract at temperatures: 32 °C,40 °C, 50 °C, 60 °C, 70 °C, and 80 °C are 1569 μS/cm, at 493 μS/cm, 592 μS/cm, 526 μS/cm, 474 μS/cm, 544 μS/cm, 494 μS/cm respectively.
Efficiency of SS400 steel corrosion bioinhibitor from Moringa leaf (Moringa oleifera L.) extract in NaCl solution medium
Authors: Nurhaeni  , Khairuddin  , Rosihan R
Published: February 2021

Steel was one of a metal mainly used to create things because hard, long-term, and can be generated in large amounts. It was easy getting corrosion, damage to metal material caused by environmental factors. Therefore, it was necessary preventive to reduce the corrosion rate by corrosion inhibitor. A study had been done on the efficiency of steel corrosion SS400 inhibitor from moringa leaf extraction (Moringa oleifera L.) in NaCl 3% solution medium. The objective was to determine soaking time and concentration of corrosion inhibitor from moringa leaf extract to inhibit the corrosion of the steel plate with the highest efficient value. The corrosion examination was conducted with a weight-loss method. Results showed that moringa leaf extract could be used as a corrosion inhibitor for steel plate SS400 in NaCl 3% with soaking time was five days in concentration 2000 ppm was 43.06%.
Modeling of tidal current and residual currents patterns in Tomori Bay, North Morowali Regency, Central Sulawesi Province
Authors: Sabhan  , Labania H M D , Mudin Y , Rahman A
Published: February 2021

Research has been carried out to model current patterns and residual current in Tomori Bay using Mohid Studio 2016. The model using a finite volume approach with a tidal model driven by the results of Geospatial Information Agency (BIG) predictions placed on the open boundary of the model. The modeling results are compared with the measurement results in Tomori Bay. The tidal current velocity in the high tide conditions increases the current velocity at the bay neck and weakens after passing Tokobae Island. The current velocity on the west side of Tokobae island is higher than that of the east of Tokobae. At the mouth of the bay, the current velocity on the north side is higher than at the south side of the bay mouth. The tidal current velocity is higher than the residual current with a maximum tidal current velocity of 25.3 cms−1 and a maximum velocity of residual current 12.6 cms−1. The residual current that describes the fate of pollutants while in the Tomori Bay waters. The residual flow pattern shows a vortex on the north side of the bay mouth and to the southeast of Tokobae Island.
Extreme wave height analysis using Weibull and Rayleigh distribution in some coastal areas affected by tsunami disasters and earthquakes in September 2018 at Central Sulawesi
Authors: Mudin Y , Labania H M D , Rahman Abd , Sabhan
Published: February 2021

One of the most important measures is the availability of data and information through research related to the analysis of extreme wave heights at each location to be built. This study aims to provide methods and information in determining extreme wave heights that have been required to be known when designing coastal structures and public infrastructure on the coast. In this study, the extreme wave height was calculated based on a wave model simulation with an incident wave scenario that has an extreme wave height at each research location. The results showed that the distribution of extreme wave height in the waters of Palu Bay, the coast of Banawa District, was closer to the Rayleigh distribution, while the waters of Sirenja District, Donggala Regency were more in accordance with the Weybull distribution. This difference is caused by the attenuation factor of wave height due to differences in coastal morphology. The attenuation value of wave height at Banawa beach reaches 53 - 78%, while in Sirenja District it is only 35 - 46% compared to the extreme wave height in the deep sea.
The effect of fermentation without or with lactic acid bacteria and storage time on the phytic acid, in vitro dry matter digestibility, and nutrient contents of rice bran
Authors: Marsetyo  , Sulendre I W , Mustaring  , Pamulu M
Published: February 2021

Storage of rice bran (RB) at anaerobic conditions is the potential way to reduce phytic acid (PA) and stabilize the nutrient contents. This study was aimed to examine the effect of fermentation without or with lactic acid bacteria (LAB)) and storage time on the PA, in vitro dry matter digestibility, and nutrient content of RB. A factorial completely randomized design was used in this study. The first factor was the fermentation method, RB with no fermentation (M0), with fermentation without LAB (M1), with fermentation plus LAB (M2). The second factor was storage time, namely 0 (S1), 5 (S2), 10 (S3), and 15 (S4) weeks. Each unit was repeated 4 times. Parameters measured include phytic acid (PA), in vitro dry matter digestibility (IVDMD), crude protein (CP), and crude fiber (CF) contents. A two-way analysis of variance was employed to determine the significant effect of the treatment. For PA the interaction between method and storage time and the main effects were all significant (P < 0.01). For IVDMD, only the fermentation method affected significantly (P < 0.05), with M0 as the lowest and M2 as the highest at all storage time. However, the CP content of RB was not affected significantly (P > 0.05) by treatment. In addition, the CF content of rice bran was not significantly (P > 0.05) affected by an interaction between method and storage time but significantly reduced (P < 0.01) by the method of fermentation. It was concluded that fermentation with the addition of LAB anaerobically decreased anti-nutrient content, increased the feeding and nutritive value of RB.
Analysis of seasonal variability of wave height in Makassar Strait
Authors: Labania H M D , Mudin Y , Rahman A , Sabhan  , Pranowo W S
Published: February 2021

This study was conducted to examine spatially the seasonal variability of sea wave characteristics in the Makassar Strait waters by utilizing the third generation wave model, MIKE 21 Spectral Wave Model. The study was conducted by observing seasonal variability of sea wave height in Makassar Strait waters for 10 years. The data used are wind data predicted by ECMWF every 6 hours during the period 2006 - 2015 as the main input of wave energy generation. The domain model is adjusted to the wind configuration in a uniform grid size of 5’ x 5’ which is considered to be sufficient to represent the bathymetry of the Makassar Strait waters with location limits of 1,00 0LU - 3,98 0LS and 116,15 0BT - 120,30 0BT and 15 stations. Based on the results of the study, showed that high waves occur in the west season which tends to follow the monsoonal pattern according to the local climate type. The maximum significant wave height tends to occur in the western, central and southern waters of the Makassar Strait with an average observed in the middle of the year in the June, July and August periods (east monsoon). For the study of coastal waters, maximum wave height fluctuations tend to be uniform.
Determination of rock dynamics characteristics using microtremor array measurement data (A case study: Biromaru Sigi Region, Central Sulawesi)
Authors: Efendi R , Rusydi M , Syamsuddin E , Rahman A , Hamzah A , Vilia  , Fatwa  , Ismail
Published: February 2021

The Biromaru area is located on the Palu-Koro fault line so it is very prone to earthquake shocks. This area is one of the zones that experienced destruction and caused heavy damage to settlements and various infrastructure. In an effort to mitigate seismic disasters, it is necessary to carry out studies related to rock dynamics in the area. This study was conducted with the aim of knowing the dynamic characteristics of rocks using micro tremor data. The dynamic characteristics of the rock are determined based on several parameters, including the average speed of the shear waves at a depth of 30 meters, and amplification factor. The results showed that this area has a type of still rock structure. Thus, the study area has a high susceptibility to damage due to earthquakes.