bluuebunny/crossref_metadata_2025 huggingface dataset:
Goals and Suggestions in Knowledge Map Development using SNA: A Literature Review
Authors: Suwiyanto V , Sensuse D I
Published: January 2020

As a non-ministerial government institution in charge of statistics, BPS-Statistics Indonesia must be able to provide quality statistical data through integrated and international standard statistical activities. Integrated statistical activities require a process of statistical activities that does not silo thinking. This silo thinking can be detrimental to BPS-Statistics Indonesia, especially in terms of overcoming the problem of statistical activities that have actually occurred in previous statistical activities. From these problems it is necessary to identify important knowledge that is useful to be able to be accessed and used as a lesson learned by other statistical activities. In Knowledge Management there is a tool to help identify important knowledge, namely Knowledge Map, which is assisted by analysis using the Social Network Analysis (SNA) technique. To solve the problem, BPS-Statistics Indonesia needs to conduct a study on the application of this knowledge maps with SNA technique. In this study, a study literature on knowledge maps with SNA was carried out. This literature study is in the form of Systematic Literature Review (SLR). From this literature study, an overview of the fields used as research subjects on knowledge maps with SNA, description of objectives and research suggestions currently used by researchers. This study found that the most used fields of research were non-business fields, especially in the fields of education and research. Findings regarding the purpose of the study are divided into making a design / framework or analyzing a problem. From the synthesis of SLR papers it was found that research on Knowledge Map with SNA, the purpose mostly to analyzing a problem. In this study it was also found that the suggestions for most subsequent research were suggestions for modification or refinement of research methods on knowledge maps with SNA. From these findings, BPS-Statistics Indonesia is expected to be able to take advantage and can make this literature study as the basis for the implementation of knowledge maps with SNA to solve the problem of silo thinking.
Modelling of Number to Javanese Voice Recursion using Sliding through Audio window Location
Authors: Solekhan  , Dahlan Moh. , Noor Yulita Dwi S.
Published: January 2020

This study tries to display a number to Javanese voice using recursion through sliding audio location. The modelling process is done by making the conversion of number to text and number to index, which is then used to create a voice index. Furthermore, the audio recording is adjusted to the voice index created. This audio recording is then carried out the process of determining the location of the voice index. When the numbers are entered, this number will change to the index form, from this index the next will be the location of the voice index, and from this voice index then play according to the location of the voice index. From the test results, 999 conversions can go as planned, and can change from number to Javanese voice.
Software As A Service (Saas) As A Handicraft Portal Bag
Authors: Setiaji Pratomo , Setiawan Arif
Published: January 2020

Handicrafts is one of the proud industrial products produced by the Kudus community, one of the superior products that has become a distinctive feature, craft bags are very helpful in developing the economy of rural communities in Kudus district. Kudus prestige as a center for craft bags is only limited to the merchant’s environment. Not many people know that in Kudus Regency as a center for craft bags, there are more than 50 artisans who are members of a business group. Therefore, Trading Businesses engaged in bag crafting will be better if they use an information system to facilitate the marketing process so that the public can get to know their products, in this case it is focused on the sales system

The method that will be used in this study is to use object oriented design Analysis and design of web-based bag craft portal system in Kudus Regency is a form of information technologybased information system development using the Object oriented design modeling method.

This study aims to analyze and design a web-based bag craft portal system with software as a service (SAAS) so as to produce a web-based application that can help create a forum for Handicraft entrepreneurs in a site so as to facilitate marketing their products using information.
Implementation Of SaaS Cloud Computing Services On E-Learning Applications (Case Study: PGRI Foundation School)
Authors: Fithri Diana Laily , Utomo Andy Prasetyo , Nugraha Fajar
Published: January 2020

Learning activities in PGRI Foundation schools, especially in SMA PGRI Kudus still use the conventional model that is directly face to face, so it is necessary to develop online learning media or what is now often referred to as e-learning to help teachers and students take material and do assignments by online. With online learning, teachers are expected to be able to update learning material and students can access it without constraints on place and time, besides assignments to students can be well controlled. In general, all PGRI Foundation schools in Kudus district have the same business process as well as the information system and technology requirements. But in reality, each school develops its architecture and information system separately. On the other hand, the majority of schools do not have enough budget to procure infrastructure to support the information systems needed specifically for learning activities such as e-learning. Cloud computing is often referred to as a new paradigm in the world of information technology related to resource efficiency. Cloud Computing has a service layer known as Software as a Service (SaaS). SaaS has several advantages and conveniences offered, including those related to resource efficiency and speed in developing an application. With SaaS, an application can be used at the same time by many tenants, with each tenant still being protected, so that application development costs can be further reduced. This research uses object-oriented system development methods with UML tools. This research aims to help schools in the Kudus Regency PGRI foundation improve the quality of learning by utilizing e-learning media without the need to think about the process of procurement, installation and configuration of hardware or software.
A new solution of measurement using 3D artefact to identify all location errors related to rotary axis of five-axis machine tool
Authors: Nguyen N H , Dang V P
Published: January 2020

In the manufacturing industry, computer numerical control (CNC) machine tool has been applied widely due to their high adaptability and precision in the machining of diversity shape, especially five-axis CNC machine tools. However, more error terms related to rotary axes, in which location errors are always considered as one of the most fundamental error sources, affect directly to machine tool performance. Thus, ensuring that a five-axis machine tool is machining within tolerance is a crucial demand in the market. This study investigates an efficient strategy using a specific 3D artifact to identify and characterize the location errors in rotary axes of a five-axis machine tool. The intended 3D artifact consists of a base plate, 2 standards ball with high roundness embedded on the top surface of the base. A Touch Trigger Probe will be utilized as the calibration instrument to capture the coordinate of 6 arbitrary contact points of the balls, then an optimization algorithm is applied to calculate the coordinate of the centers of the balls. By comparisons the relative position of the imaginary circles made of those centers with the ideal ones, all location errors will be measured individually.
Comparative study of bonang gamelan musical instrument between hot forging and Post Cast Heat Treatment/PCHT on microstructure and mechanical properties
Authors: Slamet S , Kusumaningtyas I , Suyitno
Published: January 2020

Metals have long been used to produce various musical instruments to date. Bonang Gamelan is one of the traditional musical instruments of Karawitan. Tin bronze was the primary choice because this alloy is capable of form and has excellent acoustic properties.

This study aims to compare the forging technique with post cast / PCHT heat treatment at a temperature of 550 °C with changes in microstructure and mechanical properties of Cu-20wt.% Sn and Cu-22wt.%Sn. Characterization of mechanical properties includes hardness/VHN, tensile strength σs), and bending (σb).

The forging and post-cast heat treatment/PCHT can improve the mechanical properties of hardness, tensile strength, and bending of the bonang gamelan product. The heat treatment process at 550 °C followed by holding time for 4 hours, followed by quench was able to produce grain growth and homogenization of the eutectic phase. The modulus of elasticity of the bonang gamelan specimen to the tensile strength was inversely proportional to the bending strength.
Increased Corrosion Resistance On Cu35%Zn Surface By Shot Peening Process
Authors: Priyambodo Bambang Hari , Suhartoyo  , Slamet Sugeng
Published: January 2020

Cu35Zn is a metal with a copper matrix that has the properties of forgings and has good corrosion resistance. Cu35Zn is commonly known as brass metal. Brass is widely used by industry to make various metal components. Brass for engine components must be able to withstand statistical and dynamic loads. One of these components is a ship propeller made of brass. These components must be able to withstand axial loads and have high corrosion resistance. To improve physical and mechanical properties, surface treatment needs to be done with the shot peening method. Shot peening is done with steel shot ball with a diameter of 0.5 mm with a hardness of 40-50 HRC. Shooting distance between nozzles and 100 mm specimens for 4, 6 and 8 minutes. The shot peening pressure varies 7, 8 and 9 bars. Corrosion tests according to the ASTM G5-94 standard are carried out in a 3.5% NaCl solution, instead of seawater. The results showed an increase in the best corrosion resistance of 0.028 mpy at 8 Bar shot pressure, which is 2.8 times compared to raw materials.
Preparation of special-purity scandium for designing plastic and breakable materials based on the metal
Authors: Burkhanov G S , Kolchugina N B , Roshan N R , Prokofev P A , Gorbunov S V , Dormidontov N A , Rusinov D A , Bakulina A S , Skotnicova K
Published: January 2020

The development of advanced technologies is related to the preparation and application of rare-earth metals. The tendency of development of rare-earth metal (REM) industry in Russia consists in tending to shed its dependence on the importation of REMs, to organize their production and products based on them in the required quantities, and to find new application fields for REMs. The aim of the present study is to elaborate the purification technologies of scandium and scandium hydride and to approbate its application as breakable additions to powder mixtures for the preparation of Nd-Fe-B permanent magnets. It is demonstrated the possibility to control the grains size of the 2-14-1 phase in Nd-Fe-B with the ScH∼2 addition. Moreover, our systematic studies are aimed at the development of corrosion-resistant Ag-free Pd-based REM-containing alloys with the high hydrogen permeability for the separation of high-purity hydrogen from hydrogen-containing mixtures. In the present study, the hydrogen permeability and mechanical properties of Pd-Sc thin foils prepared with special-purity scandium are discussed
Modification of contact surfaces of steel based materials in dry sliding under electric current of high density
Authors: Aleutdinova M I , Fadin V V , Aleutdinov K A
Published: January 2020

The purpose of the work was to study the interrelation of primary structure and wear resistance as well as to receive the initial ideas on contact features and surface layer deterioration in dry sliding against steel under electric current. The tribological behaviour of bearing steel and Hadfield steel (13% Mn) as well as the behaviour of composites on their bases was studied under electric current of high-density. Using X-ray phase analysis it was shown that the electrical current caused a modification of the surface layer of bearing steel and bearing steel sintered composite due to the formation of tribolayer and sliding surface melting in dry sliding against quenched AISI steel 1045. The formation of FeO in the tribolayer was observed also. This contributed to hardening of the sliding surface and to the realization of low wear intensity. Hadfield steel and a sintered composite based on it were capable of forming a tribolayer, where there was a low content of FeO on the sliding surface. This led to a high wear rate due to adhesion. The low thermal conductivity of Hadfield steel based materials should be considered as another reason for the rapid deterioration of their tribolayers.
Ab initio density functional theory calculation of 5-7 graphene polymorphs
Authors: Belenkov M E , Chernov V M
Published: January 2020

Three structural varieties of graphene layers consisting of pentagon and heptagon were calculated by the density functional theory method in the generalized gradient approximation. The sublimation energies of 5-7 polymorphs of graphene are 7.49, 7.51, and 7.28 eV/atom for T1, T2, and T3 layer types, respectively. The maximum sublimation energy and the highest stability are observed for the L5-7 T1 layer in which the deformation of the angles between the bonds in the structure as compared to hexagonal graphene is minimal. The conductive properties of layers 5-7 of graphene are metallic, since the band gap at the level of the Fermi energy is zero.
Comparison of two test methods for bending small disks on an annular support
Authors: Yu Goltsev V , Grigoriev E G , Osintsev A V , Plotnikov A S , Sedegov A S
Published: January 2020

Two methods of bending thin disks on an annular support are compared. The methods differ in the type of loading indenter and the equations that determine the strength of the material by the test results. The end surfaces of the indenter are flat cylindrical (indentor 1) or spherical (indentor 2). The methods were used to test identical disc samples from model materials: cast iron and graphite, as well as aluminum oxide samples obtained by spark-plasma sintering. The results of testing 24 disks of model materials and 10 disks of aluminum oxide on the ring support are presented. Bending diagrams of 12 disks of each model material on the annular support using two types of indentors indicate their different tensile strength. The calculated values of strength and their spread were higher when using indenter 2 than when using indenter 1. Thus, comparative tests have shown that the calculated strength of the tested materials depends on the nature of the failure of the samples and the type of bending diagram. The most reasonable were the test results obtained with the use of a flat-tipped indenter, which coincide with the characteristics of the strength of materials and the minimum spread of values.
A probabilistic model of fracture of the composite material of a composite overwrapped pressure vessel
Authors: Eremin N V , Moskvichev V V
Published: January 2020

A probabilistic numerical model for fracture of unidirectional composite materials is developed. The algorithm for numerical simulation of the model takes into account the random distribution of carbon fibers, the spread of mechanical properties and the fracture of the structural elements of the material. Multivariate numerical experiments of the composite material of a composite overwrapped pressure vessel under tensile loads were carried out. The analysis of the patterns of deformation and fracture of a composite material is carried out. The physical mechanism of deformation and fracture of a composite material corresponds to a numerical model. The stress-strain curves of a numerical model of a composite material at 70% carbon fiber content are presented. The calculated values of Young’s modulus and tensile strength of the composite material at different percentages are obtained. A comparative analysis of experimental and numerical results showed that the results corresponded to 15%. Using of a numerical model of deformation and fracture of unidirectional composite materials makes it possible to track the mechanics of the processes of fracture of fibers and matrix, to obtain the most accurate analysis of the stress-strain state, and to develop generalized methods for calculating the strength of composite overwrapped pressure vessels
Regularities of destruction of glass tube during compression
Authors: Ermishkin V A , Kulagin S P , Minina N A , Tomenko A K
Published: January 2020

The work is devoted to the study of patterns of destruction of glass tubes. During the study of specimen deformation by compression, a video was taken, the results of which were analyzed by photometric analysis of structural images. Studies have revealed a phenomenological picture of the deformation behavior of glass tube products.
Strength of welded connections of glass and metal
Authors: Ermishkin V A , Kulagin S P , Minina N A , Tomenko A K
Published: January 2020

The purpose of this study was to study the strength of products, which was a structure made of a glass tube, to which molybdenum fringes were welded to the ends. Simultaneously with the deformation on the Instron-3382 testing machine, a video survey of the surface of the samples was carried out, which was analyzed by photometric analysis of structural images. It was shown that the product is elastically deformed and that the presence of edging reduces the structural strength of the product.
On the theory of scale structural fatigue of metals at the proportional loading
Authors: Zavoychinskaya E B
Published: January 2020

The probabilistic multi-level model of metal fatigue at proportional loadings is presented. A system of hypotheses about the step-by-step grow of metal defects on micro-, meso- and macroscale levels is formulated. Here are proposed constitutive relations for the failure probability and a system of fatigue curves and equations of multilevel damage. The amplitude of the maximum principal stress is chosen as a variable, the material functions are determined according to fatigue tests, taking into account the results of physical research of brittle crack grow and in accordance with experimentally valid criteria of fatigue strength. It is shown the correlation between predicted fatigue strength and experimental data for steel 12XH2A, S135 and some ductile steel at combined tension and torsion.
Study of the kinetics of spark plasma sintering of ultrafine-grained hard alloys WC-10%Co
Authors: Lantsev E A , Chuvil’deev V N , Nokhrin A V , Boldin M S , Malekhonova N V , Blagoveshchenskii Y V , Isaeva N V , Tsvetkov Y V , Andreev P V , Smetanina K E
Published: January 2020

The effect of carbon on the kinetics of spark plasma sintering (SPS) of submicron powder compositions WC-10wt.%Co is investigated. Free carbon in the form of graphite was added into submicron powders by mixing. The activation energy of solid-phase sintering under the conditions of isothermal hold and continuous heating rate sintering was determined. It was shown that an increase in the carbon content leads to a decrease in the volume fraction of particles of the η-phase and a shift of the shrinkage curve to the region of lower heating temperatures. It was established that an increase in the graphite content does not significantly affect the activation energy of sintering of submicron powders in the region of “average” heating temperatures, the value of which is close to the activation energy of grain boundary diffusion in cobalt. It has been shown that an increase in graphite content leads to a significant decrease in the activation energy of compaction of WC-Co powders in the region of “high” sintering temperatures due to a decrease in the concentration of tungsten atoms in the γ phase based on cobalt. The kinetics of sintering of fine-grained WC-Co hard alloys is limited by the intensity of the cobalt diffusion creep by Coble.
New method of the estimation of the bending strength of ultrafine-grained structural ceramics for application in the conditions of multiaxial stress-strain state
Authors: Popov A A , Berendeev N N , Boldin M S , Nokhrin A V , Chuvil’deev V N
Published: January 2020

A new method of mechanical testing of high-strength ultrafine-grained ceramic materials by the method of spark plasma sintering (SPS) is proposed. A promising scheme for testing cylindrical SPS-samples is the “Ball on three balls test” (B3B) scheme. The B3B test method has advantages over the standard four-point bending test method, since it is not necessary to cut standard samples from disks, cylindrical samples are aligned on a special support. In this paper, we present a methodology for processing experimental B3B test data developed using the finite element method. The finite element method for estimating the parameters allows us to consider a larger number of parameters that affect the absolute value of the maximum principal stress. The experimental data processing technique takes into account the influence of the sample size, equipment geometry, physical and mechanical properties of the material, and friction coefficient.
Obtaining two-layered pipes and rods using explosion energy and hot deformation
Authors: Yu Malakhov A , Saikov I V , Denisov I V , Cherezov N P , Gamin Yu V , Romantsev B A
Published: January 2020

In this work, experimental studies were carried out to obtain bimetallic pipes and rods using explosion welding and hot deformation. The cladding layer was made of 08Cr18Ni10Ti stainless steel. It was found that explosion welding provides high-quality adhesion of the bimetal layers. Subsequent hot plastic deformation did not affect the ratio of the component layer thicknesses and the quality of the welded joint, which is confirmed by studies of the microstructure and mechanical tests of samples for flattening. Based on the results obtained, a combined technology for the production of bimetallic pipes and rods with a combination of layers of steel 20 + 08Cr18Ni10Ti was developed and tested.
The effect of cyclic deformation on the mechanical, elastic and acoustic characteristics of austenitic stainless steel
Authors: Mishakin V V , Gonchar A V , Klyushnikov V A , Serebryany V N
Published: January 2020

The effect of elastoplastic cyclic straining on the elastic and acoustic characteristics of austenitic stainless steel AISI 321 is investigated. A change of the elastic characteristics of austenitic stainless steel associated primarily with martensitic transformations that affect the accumulated energy density is found. The influence of the amplitude of strain cycle on development of the elastic anisotropy is analyzed. The possibility of determining the stress amplitude of the fatigue loading cycle by an acoustic method involving measuring the elastic characteristic of the material has been demonstrated. The relationship between changes of elastic characteristics and damage is suggested; it can be used for evaluation of fatigue life by the acoustic method.
Determination of nanocharacteristics of strength of structural materials based on signal recording and simulation of time dependences of acoustic emission parameters
Authors: Nosov V V , Grigorev E V , Pavlenko I A
Published: January 2020

Non-destructive testing of the strength of structural materials and products from them is currently based on the correlation between the strength characteristics of the material in a real object and the results of laboratory tests of the strength of standard macro samples. The strength properties and conditions of control’s heterogeneity of different material’s zones of a complex real object make this correlation ambiguous, introducing uncertainty in the results of control. The solution of the problem is connected with the necessity of information transfer to the micro-and nano-level control that determines the strength, the universal physical nanoconstants and the applying of representative micro structural elements of the material as reference. The selection’s principles of these elements and the method of assessing their strength characteristics are considered on the basis of information filtering the results of recording acoustic emission signals (AE) and the micro mechanical model of its parameters.
Room-temperature coefficient of thermal expansion of metals derived from the elastic constants
Authors: Palii N A , Belousov O K
Published: January 2020

Room-temperature coefficients of thermal expansion (CTE), α, of 27 metals and 2 semi-metals (Si and Ge) are derived from elastic constants (Young modulus, shear modulus, Poisson’s ratio) coupled with a Debye treatment of the vibrating lattice. Theoretical values of αcalc show good agreement with the experimental ones.
Structure and Mechanical Properties of the Aluminum Alloy 1570C after Multidirectional Forging with Decreasing Temperature and Subsequent Rolling
Authors: Sh Sitdikov O , Avtokratova E V , Ilyasov R R , Markushev M V
Published: January 2020

The effect of multidirectional forging (MDF) with decreasing temperature and subsequent warm and cold rolling on the structure and mechanical behavior of the alloy 1570C (Al-5Mg-0.18Mn-0.2Sc-0.02Zr (wt.%)) was studied. The first MDF step was carried out at a temperature of 325°C to a strain of about 12 and the second step at 250°C to the strain of about 6. Subsequent rolling was performed in isothermal conditions at the appropriate MDF temperatures, as well as at room temperature with reductions of about 80%. The best complex of service and technological properties, involving data on the parameters of strength, plasticity, superplasticity, was obtained in sheets rolled from high-temperature MDF billet. Despite the more significant grain refinement and unique strengthening, the MDF temperature decrease led to almost complete degradation of superplastic properties. The nature of the alloy behavior found was discussed in detail.
Physical and mechanical properties and structure of copper-based composite materials for diamond tools binder
Authors: Smirnov V M , Shalunov E P , Golyushov I S
Published: January 2020

The article describes the structure and physical and mechanical properties of dispersion-strengthened composite materials of Cu-Al-Ti-Sn-C-O system developed as a binder for making diamond tools for grinding composite materials and, in particular, hard alloys. It is shown that the materials under analysis have high thermal conductivity and recrystallization temperature values and are not inferior by mechanical properties to Cu-Sn system binders and, in particular, Cu-20 Sn binder widely used in the industry.
Quantum-mechanical calculations of the concentration dependence of the total energy of sigma-phase of the Fe-V system for the ground state
Authors: Kupavtsev M V , Udovsky A L
Published: January 2020

The purpose of this work is to study the region of existence of the sigma phase of the Fe-V system. The original algorithm for finding the minimum total energy was developed and tested depending on two independent variables. The optimized values of the lattice parameters for the σ-phase alloys of the Fe-V system are calculated. Dependence of the mixing energy of the σ - phase as a function of the composition x (V) of the sigma - phase of the Fe-V system was obtained. The calculations were carried out using the license package of quantum-mechanical calculations WIEN2k.
Study of the structure of mixed Zr-Y-O and Zr-Y-Mg-O oxides by XRD and XAFS methods
Authors: Moroz E M , Zyuzin D A , Kriventsov V V , Udovsky A L , Saenko I S
Published: January 2020

A comparative study was carried out of the structure of samples of zirconium oxides modified by yttrium and magnesium, synthesized by coprecipitation and calcined during 10 days at a temperature of 1250 °C. Refinement of the structure of the samples according to diffraction data within the framework of the fluorite type, gives high uncertainty factors, regardless of composition, and variation of structural parameters does not reduce their value. EXAFS analysis of the local structure of the samples revealed separate clusters consisting only of yttrium and oxygen ions in the structure of both samples. It has been suggested that the presence of these clusters prevents refinement of structures using the model of statistical solid solution with a fluorite structure.
Quantum-mechanical calculations of the difference of structural energies C14 and bcc phases C14 Fe and Mo and formation energy of ferromagnetic C14 Fe2Mo Laves phase
Authors: Vasilyev D A , Udovsky A L
Published: January 2020

The structural energies of iron and molybdenum in the BCC and C14 Laves phases in the Fe – Mo system, formation enthalpies and bulk elastic moduli are calculated for further use in the calculations of the BCC / BCC+C14Fe2Mo Laves phase boundary at low (room) temperatures.
Design parameters of heat exchange equipment optimization
Authors: Fesenko T N , Shitova L I , Dronova E A
Published: January 2020

The dynamics of straight tubes bundles in heat exchangers, in cross flow of coolant, is considered. The proposed mathematical model allows to determine quantity values which are fundamental in assessing the wear vibration intensity in contact points of tubes with intermediate supports taking into account gap values between tube and support. Tube vibration data obtained by application of this mathematical model (sliding path, contact tubes load in gaps, strain, response frequency structure) allow optimization of design parameters (gaps in intermediate supports, supports number and their location along the tubes length) and operational parameters of heat exchange equipment.
Dispersion methods of preparation of nanosized biological agents for vegetable crops
Authors: Folmanis G E , Fedotov M A
Published: January 2020

The effect of iron and selenium colloidal solutions on seeds was studied. The obtained results showed a different reaction of plants to treatment with solutions of nanosized iron and selenium. Onion seeds in both cases showed low germination – 15%. Colloidal iron treatment showed 100% germination of zucchini and radish seeds as in control, but an iron concentration of 10 mg/l inhibits plants. The greatest root length for beets, cucumbers and carrots was noted at a dose of nanosized iron of 1 mg/l. The root length in the experimental and control samples of zucchini and radish do not differ within the error limits. An increase in seed germination during treatment with nanosized selenium compared with the control samples was observed in onions, carrots, cucumbers, turnips, pumpkins and clarkia. Seed germination of aster was 15%, while in the control sample germination was absent. Nanopowders stimulate the processes of adaptation and self-organization of biological systems and reduce the negative impact of adverse environmental factors.
The control features of thermal characteristic details from alloy with shape memory effect
Authors: Khasyanova D U
Published: January 2020

In the article shows the properties of alloys based TINI with shape memory effects and superelasticity. For high-quality application of such properties of the alloy and the operating conditions, it is necessary to carry out a comprehensive control of thermomechanical characteristics. Therefore, it is necessary to make a standard control, carried out before the launch of a batch of material, and control of phase transformation temperatures for each billet. The article presents the control principles of thermomechanical characteristics of the workpiece material for their using in various operating conditions.
The effect of low temperatures on the operability of products 20GL steel
Authors: Khlybov A A , Kabaldin Yu G , Anosov M S , Ryabov D A , Naumov V I , Sentyureva V I
Published: January 2020

The influence of low temperatures on the cold brittleness of 20GL steel is considered. Tests were carried out on the impact strength of samples of 20GL steel in the temperature range from t = - 60 ° C to a temperature of t = 20 ° C. Fractographic studies of fractures were carried out using optical and electron microscopy. The studies were carried out after normalization, as well as after thermocyclic treatment. The research results showed that thermocyclic treatment leads to an increase in strength characteristics, grain refinement. At the same time, the temperature of the brittle-viscous transition is slightly shifted to the region of positive temperatures.
Hard carbon coatings antifriction properties improvement by alloying
Authors: Buyanovskii I A , Khrushchov M M , Levchenko V A
Published: January 2020

The efficiency of hard carbon coatings with different structure to improve the tribological performance of contacting surfaces of machine parts working in heavily loaded conditions has been analyzed. The possibility of increasing the antifriction and wear-resistant characteristics of these coatings by doping them with metals of the chromium subgroup of the Periodic table has been demonstrated. The possible mechanisms of hard carbon coatings dry and boundary friction tribological properties improvement by alloying have been considered. The possible role of alloying elements choice, structural and tribochemical factors has been discussed.
Research of the metals elasticoplastic cyclic deformation process at reduced temperature
Authors: Kabaldin Y G , Khlybov A A , Anosov M S , Shatagin D A
Published: January 2020

In the present work the test results of steel samples 20 and 45 at a temperature 20° C and -30°C when exposed to variable loads are shown. Fractographic studies of breaks were carried out using optical and electron microscopy. A comprehensive analysis of the materials destruction process, based on the analysis of acoustic emission signals, was also conducted. To estimate the damage of metals the algorithm that uses indicators of fractal dimension and informational entropy of the acoustic emission signal is proposed. The research results showed that the characteristics of fractal dimension and information entropy expand and supplement the capabilities of acoustic methods in the problems of evaluating the performance of materials with low-cycle fatigue at low temperatures.
A modified capacitance model of shunt micro switch based on MEMS technology in actuation mode: simulation and analytical study
Authors: Kurmendra  , Kumar Rajesh
Published: January 2020

In this paper, a modified mathematical model for capacitance analysis of micro-electro-mechanical switch based on Agarwal’s Model has been presented. This model is applicable in the condition when the micro-switch is supplied with electrostatic voltages. Effects of perforated structure and fringe field are accounted for accurate capacitance analysis of the micro-switch. The switch parameters such as thickness of dielectric material and actuation voltage for micro switch have also been considered in the present study. The switch is designed and simulated using COMSOL Multiphysics tool and results obtained through simulations have been validated using MATLAB software. It is found that the results obtained by simulation and mathematical model are in agreement closely for the presented study. This model could be used for evaluation of capacitance in downstate of the micro-switch for symmetric structures.
Performance analysis of a modified reduce component count multilevel inverter
Authors: Khodijah S , Ismail Baharuddin , Isa Muzamir , Syahril M , Rohani M N K H
Published: January 2020

Reducing component in circuitry is desirable in many innovations. In multilevel inverter (MLI) perspective, the increasing of switching devices for a higher-level output will significantly increase power losses, thus affected the output harmonic distortion. In this paper, an extended and simplified three-phase reduce component count multilevel inverter (RCCMLI) structure adapted from S. S. Lee, Cascaded Compact-Module Multilevel Inverter (CCM-MLI) is demonstrated and analysed. Symmetrical reduce component structure with H-bridge inverter is considered in this work. For simplification purpose, the current path conduction for reverse current is not demonstrated in this paper. A simulation-based result is presented to observe the performance of RCCMLI with regards to its output voltage harmonic content. Related predetermined parameter values are included in this report. Particularly, this paper verified the aforementioned RCCMLI, but in higher level and three-phase application, which will further improve the pseudo-sinusoidal inverter output as it eliminates the triplens harmonic component compare to single-phase environment. As for the lower order odd harmonics elimination, computational algorithm namely Particle Swarm Optimization (PSO) has been implemented in the RCCMLI control strategy. In comparison to the traditional Cascaded H bridge (CHB), this work finds that employing the switching angle optimization in the proposed RCCMLI produce comparable improvement in minimizing the output voltage harmonic and able to bring the output quality closer to comply with IEEE 519 distortion limit with fewer components and compact size inverter.
Investigation on partial discharge activities in cross-linked polyethene power cable using finite element analysis
Authors: Isa M A M , Rohani M N K H , Rosmi A S , Isa M , Rosle N , Mustafa W A , Daniel I N , Roslan M A
Published: January 2020

The nationwide usage of cross-linked polyethylene (XLPE) for medium to high voltage distribution networks are practically common due to its excellent electrical, thermal and mechanical properties and widely installed through existing network of cable line in Malaysia. However, cable exposures to harsh climates coupled with inadvertent damage throughout installation or transportation are influencing the presence of voids inside the insulation leading to the initiation of partial discharges (PD) in the cable line. Therefore, this study is important to investigate the activities of PD due to the manifestation of voids in XLPE cable and how it affects the physical, electrical and mechanical characteristics of the cable. Analysis has been performed using Finite Element Analysis (FEA) tool to simulate the PD activities in a 2D model of a three (3) core-XLPE insulated armoured sheathed cable (500 mm2, 11 kV) with several placements of voids. The varied placement and radius of voids is very crucial in order to achieve comprehensive analysis. From the obtained result, it has been established that closest the void to the core yielded higher electric field potential. Additionally, it is verified from the simulation that the larger the size of void, the higher the electric field potential consequently increasing the current density inside the void. This simulation and analysis is quite important to provide better insight pertaining to the behaviour of PD in correspond to the presence of voids which will accelerate ageing failure in insulation framework of the XLPE cable.
Multiple switching pattern for a modified reduce switch multilevel inverter: A comparison analysis
Authors: Arshad M H , Khodijah S , Ashbahani Mohamad Kajaan Nor , Mohd Nayan Norkharziana , Mat Isa Zainuddin , Ismail Baharuddin , Izati Abdullah Nor
Published: January 2020

A primary concern of multilevel inverter is its capability to produce desired alternating voltage close to sinusoidal at the output, using multiple sources of DC voltage input. Mostly a multilevel inverter is used to generate the AC voltage from DC voltage. The aim of this paper is to investigate the output of 9 level multilevel inverter by modifying the conventional 5 levels H-bridge cascade multilevel inverter. The proposed design intending to reduce the number of switches from 16 switches to 10 switches. Implementation of different switching pattern methods; equal phase (EP), half equal phase (HEP), half height (HH) and feed forward (FF) and the related expression are presented in this paper. In the result section shows a different percentage of total harmonic distortion achieved. Out of all 4 methods, HH method suppressed distortion wave the most and resulted in the lowest THD in the proposed inverter. This paper shows that by reducing the number of switches in multilevel inverter structure maintains the same quality output as the conventional H-bridge topology. Furthermore, the manipulation of the switches firing angle contribute in decreasing the system THD.
Design of 30 kW three-phase string inverter using simulink
Authors: Fauzi F , Yasin N , Leong J H , Ismail B
Published: January 2020

This paper presents the design and simulation of a 30 kW DC to AC inverter. The inverter is designed based on the Zeverlution Pro 33K three-phase DC to AC inverter. Currently, there are 6 units of the inverters installed at 180 kW solar power plant located at Mukim Utan Aji, Perlis. So, in this paper, the results from the computer simulation will be compared to the site measurement conducted from this power plant. In this design, pulse with modulation (PWM) is used as the switching technique. Even though PWM offers the ease of LC filter design and low Total Harmonic Distortion (THD), the voltage amplitude of the sine wave output fails to achieve the required national grid parameters, i.e. 240 Vrms. To overcome this problem, a three-phase transformer has to be incorporated in the design to obtain the desired outputs. Results from computer simulation using SIMULINK show that the targeted AC parameters for all phases were achieved after comparing with the site measurement.
Efficiency of Mining Algorithms in Academic Indicators
Authors: Viloria Amelec , Hernández Palma Hugo , Niebles Núñez William , Gaitán Mercedes , Pineda Lezama Bonerge
Published: January 2020

Data Mining is the process of analyzing data using automated methodologies to find hidden patterns [1]. Data mining processes aim at the use of the dataset generated by a process or business in order to obtain information that supports decision making at executive levels [2] [3] through the automation of the process of finding predictable information in large databases and answer to questions that traditionally required intense manual analysis [4]. Due to its definition, data mining is applicable to educational processes, and an example of that is the emergence of a research branch named Educational Data Mining, in which patterns and prediction search techniques are used to find information that contributes to improving educational quality [5]. This paper presents a performance study of data mining algorithms: Decision Tree and Logistic Regression, applied to data generated by the academic function at a higher education institution.
Temporary Variables for Predicting Electricity Consumption Through Data Mining
Authors: Silva Jesús , Senior Naveda Alexa , Hernández Palma Hugo , Niebles Núñez William , Niebles Núñez Leonardo
Published: January 2020

In the new global and local scenario, the advent of intelligent distribution networks or Smart Grids allows real-time collection of data on the operating status of the electricity grid. Based on this availability of data, it is feasible and convenient to predict consumption in the short term, from a few hours to a week. The hypothesis of the study is that the method used to present time variables to a prediction system of electricity consumption affects the results.
A study on copper and galvanized grounding performance using palm oil fuel ash as new additive material
Authors: Faudzi A H M , Wooi C L , Ahmad N A , Arshad S N M , Afrouzi H N , Rohani M N K
Published: January 2020

This paper aimed to study the improvement of grounding performance by reducing the grounding electrode resistance using palm oil fuel ash as the backfill. This is achieved by mixing the soil with a specific portion of palm oil fuel ash and obtains the grounding electrode resistance value by using Three Pin Method. In order to obtain the grounding electrode resistance, the mixture of palm oil fuel ash and soil were compacted and installed with electrodes. Two types of electrodes were connected to measuring device which is Kyoritsu Digital Earth Tester Model 4105A and grounding electrode resistance values were displayed. The two types of electrodes used in this study were copper and galvanized steel electrodes. It was found that by adding palm oil fuel ash to the soil, the grounding performance can be improved to at least 90% and above for both copper and galvanized steel electrodes. The palm oil fuel ash is very effective in improving the grounding performance at low cost and environmentally friendly.
New donor-acceptor material for organic solar cells with different transfer mechanism
Authors: Ahmad S , Misrun M I , Isa M , Affendi N A M
Published: January 2020

This paper presents results from a new donor-acceptor material using easily available and renewable organic material. The new material was developed and tested using an idea of a new electron transfer mechanism using combined chlorophyll and ferrocene as the bulk-hetero junction active layer. This research aims to produce a binding between the chlorophyll molecule and the protein substitute using ferrocene so that the theory of electron transfer can be tested. The main objective of the research is to produce electricity from the new donor-acceptor material. It is observed that open-circuit voltage (Voc), short circuit current (Isc), fill factor (FF) and the efficiency (η) of the device were 0.1665V, 0.005A, 0.645 and 0.13%, respectively.
TiO2/B2O3 thick film gas sensor for monitoring carbon monoxide at different operating temperatures
Authors: Amaniah Mohd Chachuli Siti , Nizar Hamidon Mohd , Ertugrul Mehmet , Mamat Md. Shuhazlly , Jaafar H , Shamsudin N H
Published: January 2020

TiO2/B2O3 gas sensor was fabricated on alumina substrate using screen-printing technology with thickness of sensing film in between of 3 – 5 µm. The sensing film of gas sensor was prepared by mixing the TiO2/B2O3 with organic binder. The morphology and structural element of sensing film was characterized using FESEM and x-ray diffraction. The gas sensor was exposed to 100 – 1000 ppm of carbon monoxide at different operating temperatures such as 100°C, 150°C, 200°C and 250°C. The result showed that the gas sensor behaved as n-type gas sensor and exhibited good response to various concentration of carbon monoxide at different operating temperatures. It also was found that highest sensitivity was achieved at 250°C, while optimal operating temperature was occurred at 150°Cfor TiO2/B2O3 gas sensor to the carbon monoxide.
Extraction system for the industrial use of essential oil of the subtle lemon (citrus aurantifolia)
Authors: León César , Jordán Edisson P. , Salazar Karina , Castellanos Esteban X. , Salazar Franklin W.
Published: January 2020

The use of essential oils as raw material in formulation of by-products allows the revitalization of industries and regional economic growth. This is the reason why in this work it is described the process to design an extraction system of essential oil from subtle lemon. Main parameters required for the extraction have been considered as well as, the calculation of the obtained yield. Within the system design, distillation tank measurements, condenser, essential oils separator, mechanical part of the equipment, boiler selection and the distribution of the plant are dimensioned. The procedure manuals and equipment operating manuals were prepared for each step of the process of using this oil.