bluuebunny/crossref_metadata_2025_split huggingface dataset:
A comparative study of multivariate Fay-Herriot model for small area estimation in various sample sizes
Authors: Nurizza W A , Ubaidillah A 
Published: July 2019

Abstract
In general, surveys are designed for large areas with sufficient sample size. If the survey is used for small areas in which the sample sizes are not sufficient, the results of estimates may not be reliable due to the large standard error. Therefore, a Small Area Estimation (SAE) method was developed, to increase the effectiveness of the sample size by borrowing the strength of the neighboring region and information from the auxiliary variables that have a strong relationship with the observational variable. This study aims to analyze the SAE using Multivariate Fay-Herriot (MFH) model and Univariate Fay-Herriot (UFH) model for a variety of sample sizes. Simulations were conducted by using household expenditure per capita of food group and non-food group data from Susenas on March 2017. The simulation results showed that the average Root Mean Square Errors (RMSEs) using the MFH models in various sample size are smaller than the UFH model and the direct estimation.
Clustering of protein-protein interactions (PPI) and gene ontology molecular function using Markov clustering and fuzzy K partite algorithm
Authors: A Kusuma W , F Ahmad H , Suryono M 
Published: July 2019

Abstract
Functional disorders of proteins in the human body can cause a certain disease. The function and role of the protein are represented by Gene Ontology (GO). In this study, the GO molecular function was used to enrich the analysis of protein-protein interaction (PPI). The relationship between PPI and GO molecular function was represented in a bipartite graph. In the pre-processing step, the PPI network was reduced using the Markov clustering algorithm to obtain the group of proteins with the highest modularity score. The fuzzy k partite algorithm was used to cluster the PPI network and GO molecular functions into several groups. The result of Markov clustering showed the accuracy of 84.6% compared to that of the same algorithm using the GIANT package on Cytoscape applications, one of the popular software for network analysis. Proteins obtained from Markov clustering results were used as inputs to obtain their related GO molecular function. Their relationship was represented as a bipartite graph which is used as an input for the fuzzy k partite algorithm. With the dataset of Diabetes Mellitus type II, the results of Markov clustering showed that there were 117 proteins and 328 related GO molecular function. With fuzzy k partite algorithm, the minimum cost for the bipartite graph is 594.175 at the 20 clusters of proteins and 29 clusters of GO molecular functions.
Outlook for carbon stock of tropical forest in the context of climate change
Authors: Dasrizal  , Rahmi  , Rezki A , Farida  , Ulni A Z P , Syafruddin Y S 
Published: July 2019

Abstract
There has been a large increase in understanding the relationship between aboveground forest biomass and climate change in recent years. Aboveground Biomass (AGB) estimation is very important in understanding the contribution of forests to the regional carbon cycle. AGB in tropical forest areas is often carried out by utilizing the transformation of the vegetation index because the value obtained is a combination of several channels in the image to highlight the appearance of vegetation. Difficulties in field surveys due to tropical forest field conditions transform the vegetation index calculation is an effective alternative approach to estimate biomass. The purpose of this study is to estimate biomass by utilizing remote sensing data to estimate carbon stock. The study was conducted on tropical forests in Solok Regency, West Sumatra Province. The method used is calculating the surface biomass content with the index value of each transformation of the vegetation index type. The results of this study show the level of accuracy and total carbon content of each transformation of the vegetation index type (NDVI, TNDVI, RVI, TRVI). NDVI is the best accuracy for estimating biomass density with R2 of 60%. The surface biomass estimates in Solok Regency as 115.6 tons/ha. The amount of stored surface biomass varies, depending on the level of greenness and the age of the vegetation.
Paecilomyces lilacinus and P.variotii as a predator of nematode and trematode eggs
Authors: Ahmad R Z , Sidi B B , Endrawati D , Ekawasti F , Chaerani  
Published: July 2019

Abstract

Paecilomyces lilacinus and P.variotii are molds that can control the parasitic worms for animals and plants. The molds have been used as biological control of plant nematodes and more commercialized, but for controlling animal trematode worm parasite has not been known. For the purposes of the experiments were tested in vitro the ability local isolates of P.lilacinus and P.variotii to reduce (predator) worm eggs of Meloidogyne sp and Fasciola gigantica. The tests carried out on the eggs of the two types of worms, by adding some eggs on P. lilacinus and P.variotii spores that have been inoculated in a petri dish. The experiments were performed during a specific time with the addition of isolates for a comparison test. The result of the test from this experiment was P. lilacinus is better than P. variotii to reduce types of those worms.
The effect of cymbopogon citratus essential oil on community dynamics of biofilm-forming bacteria isolated from brine water of oil reservoir in South Sumatra
Authors: Purwasena I A , Aditiawati P , Siwi I K , Fauziyyah N A 
Published: July 2019

Abstract
Biofilm induces an electric potential difference on metal pipelines of oil and gas industries which result in accelerated pipeline corrosion. This study evaluated Cymbopogon citratus essential oil nanoparticle performance as an antimicrobial to prevent metal corrosion. This study aims to determine C. citratus essential oil nanoparticle’s minimum inhibitory concentration (MIC), minimum biofilm inhibitory concentration (MBIC), minimum biofilm eradication concentration (MBEC), and its effect on bacterial community dynamics. C. citratus essential oil was encapsulated by ionic gelation. MIC, MBIC, and MBEC were determined by the microdilution method. Bacterial community dynamics were analyzed using Total Plate Count. Biofilm-forming bacteria were isolated from brine water of South Sumatra oil reservoir which identified as Pseudomonas sp. 1, Pseudomonas sp. 2, and Pannonibacter pragmithetus based on 16S rRNA sequence similarity analysis using NCBI-BLAST. C. citratus essential oil nanoparticle was successfully formed which was 174.1 nm in size, having MIC and MBIC value at 0.03%, and MBEC value at 0.06%. Pseudomonas sp. 1 was the most affected by essential oil nanoparticle exposure on planktonic phase while P. pragmithetus was the most affected on sessile phase. Based on this study, C. citratus essential oil nanoparticle has the potential to be an antimicrobial agent to prevent metal corrosion.
Morpho-physiological analysis of aquatic plants for phytoremediation of wastewater from gold mine wastewater treatment installation (IPAL)
Authors: Fathia S D , Hamim H , Triadiati T 
Published: July 2019

Abstract
Several types of aquatic plants have a potential role in reducing pollutants from contaminated water through phytoremediation processes. The purpose of this study was to analyze the capacity of aquatic plants in phytoremediation process of cyanide and heavy metals from gold mine liquid waste, based on the growth and heavy metal deposition in the root and shoot. The study was conducted using a completely randomized design with two factors, i.e., the concentration of gold-mine wastewater (0%, 50%, and 100%) and the combination of two aquatic plants from 4 species (Eichhornia crassipes, Neomarica longifolia, Hydrilla verticillata, and Pistia stratiotes). The results showed that gold mine wastewater generally reduced the growth rate of all the plants, especially at 100% wastewater concentration. The treatment with gold mine wastewater caused an increase in lipid peroxidation specified by the increase of root and leaf MDA content, while it decreases leaf chlorophyll content significantly. The best combination of aquatic plants for gold mine phytoremediation was shown by N. longifolia – P. Stratiotes based on the smallest dry weight reduction and the greatest reduction of cyanide, Pb and Hg from the media.
Catalytic cracking of Jatropa curcas oil using natural zeolite of Lampung as a catalyst
Authors: Aziz I , Adhani L , Yolanda T , Saridewi N 
Published: July 2019

Abstract
The scarcity of fossil fuel has led to the development of renewable energy sources, such as biofuel from plant oils. Jatropha curcas oil is one of the potential plant oil sources of biofuel. The conversion of Jatropha oil into biofuel can be achieved through catalytic cracking using the catalyst of Lampung natural zeolite. This study aimed to characterize the catalyst, to determine the optimum condition of the catalytic cracking process and to study the physicochemical characteristic of biofuel. The study was begun by activating Lampung natural zeolite, characterizing the catalyst, optimizing the catalytic cracking process and testing the biofuel. XRD result showed that the activated natural zeolite has a crystal structure, as suggested by the appearance of high-intensity peaks at 23.72º; 22.38º and 27.96º, which showed the generation of H-zeolite. Thermogravimetry analysis showed that H-zeolite started to decompose at 300 ºC with 7.4% mass reduction and has thermal stability up until 700ºC. The surface area of the zeolite was 53.2542 m2/g. The optimum condition for the cracking process was achieved at 375 °C for 2 hours and 5 % concentration of catalyst. The biofuel generated from this study consisted of 67.12 % gasoline (C5-C11), 11.87 % kerosene (C12-C15) and 21.01 % diesel (C16-C20). This biofuel has a density of 0.966 g/mL and pours point of 235°K.
Growth of 3C-SiC phase on silica-carbon composite with the carbothermal reduction method
Authors: Ichsan S , Fuady M I A , Wahyuningsih S , Ramelan A H 
Published: July 2019

Abstract
Growth of 3C-SiC phase on silica-carbon composites has been conducted. Silica (95,48%) was obtained from rice husk purified using HCl then characterized with X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD) and Fourier Transform Infra-Red (FTIR). The carbon source was from activated carbon. Silicon carbide formation was synthesized using the carbothermal reduction method at temperature 1150 °C, 1300 °C, and 1450 °C. Characterization of silicon carbide phase was performed by X-Ray Diffraction (XRD) and UV-Vis Spectrophotometer. The increased temperature on carbothermal reduction process related to the intensity improvement of 2θ phase 3C-SiC(111) which indicates that the 3C-SiC phase is increasingly formed. The 3C-SiC(220) phase crystallite size increased from 20.37 nm to 22.66 nm. The formation of 3C-SiC phase and crystalline size affected on the electronic properties of the synthesized material. The band gap decreased by the increased of 3C-SiC phase formed from ∼3,2 eV (1150 °C) to ∼2,7 eV (1300 °C) and ∼2,7 eV (1450 °C).
A finite element algorithm for solution of the natural vibration problem of electroelastic bodies with passive external electric circuits, interacting with a quiescent fluid
Authors: Lekomtsev Sergey , Oshmarin Dmitrii , Sevodina Natalya 
Published: July 2019

Abstract
In this paper we consider a mathematical statement of the problem on natural vibrations of piecewise-homogeneous electroelastic bodies with passive external electric circuits (shunting circuits) of arbitrary configuration and interacting with a quiescent fluid. The behavior of the piezoelectric body is described using the equations of electrodynamics of deformable electroelastic media in the quasi-static approximation. The motion of an ideal fluid in the case of small perturbations is considered within the framework of the acoustic approximation. Small strains in a thin plate are determined using the Reissner – Mindlin theory. The numerical solution is developed using the finite element method. The proposed algorithm is based on the approach, in which the global stiffness matrix generated with the aid of the ANSYS software package is decomposed into required constituents. The system of governing equations is constructed using the developed algorithm, which is realized in the FORTRAN language. Complex eigenvalues of the examined system are defined from the solution of the non-classic modal problem using the Mueller method. A thin plate with piezoelectric element located on the free surface of a layer of a quiescent fluid of finite size is considered as an example.
Stabilization of direct numerical simulation for finite truncations of circular cumulant expansions
Authors: Tyulkina I V , Goldobin D S , Pikovsky A 
Published: July 2019

Abstract
We study a numerical instability of direct simulations with truncated equation chains for the “circular cumulant” representation and two approaches to its suppression. The approaches are tested for a chimera-bearing hierarchical population of coupled oscillators. The stabilization techniques can be efficiently applied without significant effect on the natural system dynamics within a finite vicinity of the Ott-Antonsen manifold for direct numerical simulations with up to 20 cumulants; with increasing deviation from the Ott-Antonsen manifold the stabilization becomes more problematic.
Multidisciplinary Approach to the Design of Superconducting Electrical Machines
Authors: Kovalev K , Penkin V , Ivanov N , Kosheleva N , Serovaev G 
Published: July 2019

Abstract
Compared to traditional machines, superconducting electrical machines have significant advantages, i.e: improved weight and dimensions, higher efficiency, lower values of inductive parameters, reduced noise level, greater stability when operating in electrical networks. Development of such machines requires the solution of a whole series of scientific and engineering problems related to many fields of science and technology. Along with the solution of traditional problems of the usual “warm” electrical engineering, one has to solve the problems associated with cooling of superconducting windings and the stability of their superconducting state under the action of external heat leakage, centrifugal and ponderomotive forces, as well as vibrations. The design of cryogenic machines should provide for the compensation of thermal compression of structural elements and windings during cooling process. This paper presents some interdisciplinary tasks, the solution of which will allow to reach a new level in the field of superconducting electrical machines and to create samples of electric motors and generators, surpassing all existing analogues in specific parameters.
On the Optimal Location of Several Peizoelectric Elements on the Structure Surface
Authors: Oshmarin Dmitrii A , Iurlov Maksim A , Sevodina Natalia V , Iurlova Nataliia A 
Published: July 2019

Abstract
In this paper, based on the solution of the natural vibration problem an approach for determining the best options for the arrangement of piezoelectric elements on the surface of a structure allowing an essential improvement of its dynamic characteristics is proposed. The condition for a maximum value of the generalized electromechanical coupling coefficient, which characterizes the fraction of the converted mechanical energy of vibrations into the electrical energy, is adopted as an optimality criterion. The performance of the proposed approach is demonstrated by solving an example problem of locating two piezoelectric elements on the surface of a spatial structure providing damping of its vibrations at the selected frequencies. The obtained results are substantiated by the frequency response plots of the electric potential, obtained for different options of placement of piezoelectric elements on the surface of a structure under forced steady-state vibrations.
An Algorithm for Identifying Texture Components in the Framework of Statistical Crystal Plasticity Models
Authors: Ostapovich K V , Trusov P V , Yanz A Yu 
Published: July 2019

Abstract
An approach based on involving clustering techniques to identify texture components for a given polycrystalline aggregate is formulated. A heuristic iterative clustering algorithm operating only with a sample of lattice orientations and the concept of closeness between them is proposed for this task. The mentioned closeness concept is introduced via a special pseudometric distance, which is induced by the natural Riemann metrics and takes the lattice symmetry into consideration. The developed procedure allows representing an inhomogeneous orientation distribution by localized clusters in the space of orientations and thus can be used to reduce the dimension of orientation distribution data in statistical crystal plasticity models. Two examples of such an application of the clustering procedure are provided.
Grain Structure Refinement Description in the Two-Level Statistical Crystal Plasticity Model
Authors: Ostanina T V , Shveykin A I , Trusov P V , Makarevich E S 
Published: July 2019

Abstract
As both self-consistent and direct multilevel models (suggesting solution of boundary value problems at the meso-level) are extremely resource intensive, nowadays statistical crystal plasticity models are supposed to be the most promising ones for modeling technological processes of thermo-mechanical treatment of materials. The statement of a boundary value problem at the current configuration in the rate form is preferable, as it is convenient for applying numerical methods. In this case, step-by-step solution with redefining the computational domain configuration (including contacting surfaces) is possible. The two-level (macro- and meso-level) statistical constitutive model for describing deformation of polycrystalline metals and alloys, being formulated in terms of the actual configuration in the rate form, is proposed. The flexible coordinate system at the meso-level is connected with the symmetry elements of the crystallites, which determines appropriate choice of the corotational derivative in the constitutive relation. The approximate model for describing grain structure refinement on the basis of considering the amount of accumulated inelastic deformation as an integral characteristic of the defect structure state is included into the model. The results of the test calculations for describing loading processes, being relevant for equal-channel angular pressing, are given.
Plateau-Rayleigh Instability of Ferrofluid Drop-Like Aggregates in Zero Magnetic Field
Authors: Ivanov A S 
Published: July 2019

Abstract
Experimental investigation was carried out in order to study the properties of droplike aggregates – the needle-shaped drops of condensed phase, which appear in magnetic fluids undergoing field-induced phase transition of the gas-liquid type. When the applied magnetic field is removed, the needle-shaped aggregates demonstrate the Plateau-Rayleigh instability and disintegrate into series of separate spherical drops due to the surface tension σ at the interface between the gas and liquid phases. The surface tension entirely depends on interparticle interactions, thus experimental investigation of σ allows us to analyse the influence of temperature and magnetic field on the interparticle interactions. It is shown that drop-like aggregates condensed at high temperature demonstrate higher surface tension, than the aggregates condensed at low temperature. This anomalous behaviour can be attributed to the high magnetic field intensity needed to cause the phase transition at high temperature.
Testing Mechanical Features of Rubber Composites under Biaxial Loading
Authors: Garishin Oleg K , Shadrin Vladimir V 
Published: July 2019

Abstract
The main object of studies were composites on the base of synthetic rubber filled with various nano- and micro particles, which are already used or intended to be used in the tire industry. Mechanical behavior of such materials under biaxial cyclic loading was studied experimentally. The tests were carried out using the four-vector test rig Zwick/Roell. It allows to define complex deformation trajectories in two mutually perpendicular directions independently. The test program consisted of two or three cycles of load-unload (with stops for relaxation) in one direction and then two or three more such cycles in the perpendicular one. Experiments made it possible to study viscous-elastic properties as well as the effects of softening and the occurrence of induced anisotropy in filled elastomers under the action of a biaxial load. In the case of pure rubber, they are practically absent, so unfilled system can be considered as elastic and isotropic. A different picture is observed for filled systems. All the tested composites become viscoelastic after filler input: a hysteresis loop appeared and its area (dissipative losses) enlarged with increasing amplitude of cyclic deform. Also the dependences of induced anisotropy of mechanical properties and softening on the type of filler in the composite were investigated.
Experimental study of electrical impedance in airways filled with electrolyte solution aerosol
Authors: Zuev A L , Mishlanov Ia V , Polyakov V B 
Published: July 2019

Abstract
This article presents the results of an experimental study of electrical impedance in a model cell through which the air flow containing aerosol particles of the 10% sodium chloride solution generated by an ultrasonic nebulizer passes. The active and capacitive components of admittance were determined at different values of alternating current frequency, flow rate and aerosol atomization intensity. Measurement results were compared with the most probable electrical conductivity models. An equivalent electrical circuit in the form of a parallel RC- circuit, which corresponds well to the obtained frequency dependences of impedance magnitude and phase shift angle, is proposed. In addition, a linear regression model describing the dependence of the impedance module logarithm on two parameters of the flow of aerosol particles at different electrical current frequencies is developed.
Diffraction Resonances of Acoustic Stresses in the Crystal Layer
Authors: Belyayev Y N 
Published: July 2019

Abstract
The six-beam scattering of elastic waves by a crystal film is investigated. Cases of symmetric diffraction of waves inside the crystal layer are analyzed. In this scattering geometry, the projections of the wave vectors on the normal to the film surface are pairwise equal to each other up to the sign. Under certain conditions, quasi-shear waves modulate the structure in the path of quasi-longitudinal waves. If the period of the modulated structure is close to the length of a quasi-longitudinal wave, the amplitude of oscillations of the latter is amplified. The explanation of this effect is similar to the description of parametric resonance.This effect is illustrated by examples of calculations of the scattering spectra of elastic waves by cubic and tetragonal crystals in a three-layer model. Calculations are based on the transfer matrix method.
Inhomogeneities and Extreme Fluctuations of Strains in Grains of Polycrystalline Materials
Authors: Shavshukov V E , Tashkinov A A 
Published: July 2019

Abstract
Inhomogeneity of strains in individual grains are calculated using the field-theoretical approach in the mechanics of polycrystalline materials. It is shown that the microstructure surrounding the grain strongly influences the amplitude of the non-uniformity of strains in the grain. In the random microstructure of a polycrystal, there are specific clusters of grains in which very large strain fluctuations are realized. The strains in these clusters exceed macrostrains several times. The patterns of such extreme clusters are presented. Extreme strain fluctuations in bulk grains exceed fluctuations in surface grains by 40%. This may be one of the reasons for the movement of sites of damage initiation in gygacycle fatigue mode from the surface of a polycrystalline sample into the bulk.