bluuebunny/crossref_metadata_2025 huggingface dataset:
Optical spectral sensor for the assessment of uric acid kinetics during hemodialysis treatment
Authors: Konoplev G A , Stepanova O S , Zemchenkov G A , Frorip A
Published: December 2019

The dual-wavelength direct spectrophotometric method for uric acid determination in effluent dialysate and deep UV LED based optical spectral sensor for non-invasive online hemodialysis monitoring were developed. The time profiles of uric acid concentration in effluent dialysate were recorded for a group of 12 patients and 88 hemodialysis sessions by means of the sensor. The parameters of the double-pool kinetic model for each session were assessed and analyzed. The feasibility of online optical monitoring in the UV region as a useful and convenient tool for the experimental investigation of uric acid kinetics during hemodialysis was demonstrated.
Fluorescent detection upon droplet amplification of nucleic acids
Authors: Tupik A , Bulyanitsa A , Rudnitskaya G , Posmitnaya Y , Varlamov D , Evstrapov A
Published: December 2019

Droplet microfluidics with amplification of nucleic acids allows to achieve sensitivity at the level of single molecules and is in demand in medical diagnostics, forensic science, and genetic research. The results of detection of nucleic acid amplification in liquid and water-in-oil emulsion are compared on the example of model solutions. Since the results of quantitative analysis are based on the calculation of the proportion of drops with a positive reaction result, one of the tasks was to study the features of automatic counting of drops in different zones of the reaction chamber.
Indications on self mode-locking in a broad area single-section quantum dot laser
Authors: Auth D , Korenev V V , Savelyev A V , Maximov M V , Zhukov A E , Breuer S
Published: December 2019

Broad-area edge-emitting monolithic mode-locked semiconductor quantum dot lasers emitting at 1.26 μm could potentially serve as ideal sources for the generation of high power broad optical frequency combs for short-reach inter and intra data-center links. In this contribution, the inter-mode beat frequency of a 2 mm long InAs/InGaAs quantum dot laser with a broad-ridge waveguide are studied experimentally. Laser output power, radio-frequency and spectral domain analysis is performed. -3 dB spectral widths ranging from 2nm to 5.3 nm and the existence of an inter-mode beat frequency at 20.4 GHz with a signal-to-noise ratio from 2 dB up to 11 dB are experimentally confirmed for injection currents from 0.225 A to 1 A. Our results indicate a potential way towards high output power optical frequency comb generation by electrically injected monolithic semiconductor lasers.
Performance of InGaAs metamorphic laser power converters at different conditions
Authors: Kalyuzhnyy N A , Evstropov V V , Mintairov SA , Mintairov MA , Salii R A , Shvarts M Z
Published: December 2019

The topic of the work is the metamorphic InGaAs heterostructures for laser power converters (LPC) and their performance at different measurement conditions. Three different illumination conditions were studied: monochromatic Xe-lamp uniform illumination, laser with quasi-uniform illumination (with laser beam unfocusing) and non-uniform focused laser illumination. For simulating the experimental IV-curves as well as FF-Jg, Voc-Jg
and η-Jg
dependences, a tube model developed earlier and describing the charge carrier transport along current lines was used for all three illumination regimes. In the absence of losses (Xe-lamp and unfocused laser), the perfect model simulation model exhibiting an experimental efficiency greater than 50% (for λ=1064nm) has been demonstrated. As a result of simulation of LPC characteristics obtained under focused laser illumination, the losses associated with uniform light distribution as well as with an additional resistance, which decrease the LPC efficiency, have been found.
Relation between energy gap and saturation currents in GaInAs homo p-n junctions
Authors: Mintairov M.A. , Evstropov V.V. , Mintairov S.A. , Shvarts M.Z. , Kalyuzhnyy N.A.
Published: December 2019

The paper is devoted to the relationship between the energy gap and the saturation currents (diffusion and recombination ones) of GaInAs homo p–n junctions. Such a relationship is required for developing multi-junction solar cells and photodetectors for a given wavelength. The saturation currents and the energy gap have been determined experimentally, and an empirical exponential formula was obtained for the required relationship. The results of the work allow predicting the saturation current for a GaInAs p-n junction with a given energy gap.
The effect of pretreatment of X12CrNiTi18-10 steel on surface characteristics as a result of laser hardening
Authors: Makhov N , Proskuryakov V , Rodionov I , Koshuro V , Fomin A , Borodina S
Published: December 2019

The results of studies of the effect of pretreatment of stainless chromium-nickel steel X12CrNiTi18-10 on the morphological characteristics and microhardness of the surface as a result of laser hardening are presented. It was established that with laser modification, a uniformly distributed surface microrelief is formed with a microhardness value of up to 12.58 ± 0.1 GPa.
A fair comparison of spectral properties of Slot and Hybrid plasmonic micro-ring resonators
Authors: Butt M A , Fomchenkov SA , Kazanskiy NL
Published: December 2019

In this work, we presented micro-ring resonator structures based on slot and hybrid plasmonic waveguides. The slot waveguide is formed by keeping a narrow air gap between two silicon strip waveguides. Whereas, the hybrid waveguide is composed of Metal-Air-Silicon structure, where the E-field is considerably enhanced in the narrow air gap. The transmission spectrum and E-field distribution of these structures are simulated using the finite element method (FEM). Micro-ring resonator based on hybrid plasmonic waveguide shows the best sensitivity of 333.3 nm/RIU. Whereas, slot waveguide based micro-ring resonator showed the best performance in Q-factor and the figure of merits.
Spectral Properties of Magneto-plasmonic Nanocomposite. Vertical Shift of Magneto-Optical Hysteresis Loop
Authors: Tomilin S V , Berzhansky V N , Shaposhnikov A N , Lyashko S D , Mikhailova T V , Tomilina O A
Published: December 2019

In present work the results about study of spectral features of the magneto-optical hysteresis loop (Faraday rotation) vertical shifting effect in the magneto-plasmonic nanocomposite Bi:YIG/Au(NP)/GGG are shown. It is shown that in the spectral range near localized plasmon-polariton resonance (LPPR) the magneto-optical hysteresis loop has a vertical shift (Faraday “delta”). The loop shifting at the left and right side of the LPPR have a different sign and in the resonance the loop shifting become null. It is shown that the spectral locations of Faraday “delta” maxima are due to the width of the LPPR resonant line.
Evolution of photoemission properties on Cs/GaAs and GaAs(Cs,O) surfaces under thermal cycling
Authors: Khoroshilov V S , Kazantsev D M , Zhuravlev A G
Published: December 2019

The photoemission properties on Cs/GaAs and GaAs(Cs,O) surfaces prepared at room temperature were studied under thermal cycling. The evolution of electron affinity and escape probability to vacuum was measured using photoemission quantum yield spectroscopy for the surfaces with various Cs-O overlayer compositions. It was found that an increase in the oxygen exposure led to the improvement in the thermal stability of electron affinity.
Excitation of unidirectionally propagating plasmon in the periodic graphene structure
Authors: Mashinsky K V , Popov V V , Fateev D V
Published: December 2019

The transformation of normally incident electromagnetic wave into propagating plasmon in periodical graphene structure with double grating gate is theoretically investigated. The most effective transformation appears in case of excitation plasmon modes with the wavevectors quantized with structure period. Blocking the reflection and the transmission of electromagnetic wave through the graphene structure by metal back gate and Fabry-Perot resonator are used. We found the 72% transformation of the incident wave radiation power into the power of unidirectionally-travelling plasmon for 1 ps momentum relaxation time in graphene.
Numerical modelling of an error of manufacturing of ion-exchange waveguide for the tasks of quantum computations
Authors: Gerasimenko V S , Gerasimenko N D , Kiselev F D
Published: December 2019

This paper describes modeling of single-mode waveguide and 3dB directional coupler for integrated optical quantum circuits manufactured by ion-exchange process. We present results of diffusion ion exchange simulation for Na+ ↔ K+ in the R2O-Sn2O-SiO2 glass and optical elements modeling performed by the beam propagation method. There was demonstrated that the refractive index profile in the overlapping area of directional coupler can be calculated by summing two separate profiles, and error would not exceed 3%. We were able to minimize light propagation looses in the device with about 20 mm length. It was done by reducing interaction length to zero and adjusting width of the bend. After that fabrication tolerance of the device was looked. The overall transmittance of the proposed directional coupler was evaluated as 0.96
Dynamics of cluster structures in the near-surface layer of distilled water under laser excitation
Authors: Shostka V I , Shostka N V
Published: December 2019

We explore changes in the distilled water structure by optical methods in this work. The lack of rigorous ideas about the structure of water and its organization at the molecular level hinders the development of methods not only for quantitative analysis, but also for qualitative assessment of the structure of water. Optical methods of studying changes in the structure of water are used in present work, since it is a disordered fluid whose hydrogen bonds are short-lived. The mechanism for the formation of cluster structures near the surface of a water drop is proposed. It is shown that water has unique properties associated with the presence of order in its various states due to the cooperative effect of structural and dynamic changes in a heterogeneous hydrogen bond network.
Growth and spectroscopy of orthorombic Yb:KY(MoO4)2 laser crystal with a layered structure
Authors: Volokitina A , Loiko P , Serres J M , Mateos X , Kuleshov N , Trifonov V , Pavlyuk A
Published: December 2019

We report on the growth, structure, vibronic and spectroscopic properties of novel Yb3+-doped orthorhombic potassium yttrium double molybdate crystal, Yb:KY(MoO4)2. The layered structure of this material determines a strong polarization-anisotropy of absorption and emission bands of Yb3+ ions. The maximum stimulated-emission cross-section is 3.7×10-20 cm2 at ∼1.01 μm for light polarization E ∥ b and the lifetime of the 2F5/2 state is 0.46 ms. Naturally cleaved Yb:KY(MoO4)2 plates are suitable for microchip lasers at ∼1 μm.
Two-photon photoluminescence of a thin-film hybrid material based on CdSe(core)/ZnS/CdS/ZnS(multishell) semiconductor quantum dots
Authors: Dyagileva D V , Krivenkov V A , Samokhvalov P S , Nabiev I , Rakovich Yu P
Published: December 2019

Semiconductor quantum dots (QDs) are widely used as components of hybrid materials for development of efficient light emitters and convertors. Their unique nonlinear optical properties, such as two-photon absorption and two-photon photoluminescence from biexcitons, make them promising materials for photovoltaic and optoelectronic applications. In this study, thin-film hybrid materials based on the CdSe(core)/ZnS/CdS/ZnS(multishell) QDs have been fabricated, and the two-photon photoluminescence (PL) from the generated biexcitons have been studied. The results show that fabricated thin-film hybrid materials based on the QDs are efficient fluorophores in the one- and two-photon PL regimes for applications in optoelectronics and biosensing.
Numerical modeling of the spectral and spatial distribution of the electromagnetic modes in a tunable microcavity for investigation of the light-matter interaction
Authors: Lednev M A , Dovzhenko D S , Rakovich Yu P , Nabiev I
Published: December 2019

The light-matter interaction between a molecule and confined electromagnetic field is of great interest because it allows tuning the energy states and the spectral properties of the coupled matter. This effect offers a great number of applications in many areas, such as nonlinear physics, biosensing and lasing. The most widely used approach to achieve light-matter coupling is to place an ensemble of molecules inside an optical cavity. In order to maximize the effects of interaction, it is necessary to model the spectral properties of the cavity in order to find the optimal parameters for the experiments. In this study, the model for the numerical calculation of the spectral and spatial properties of electromagnetic modes of a tunable microcavity was developed and a mode analysis has been performed. The cavity transmission spectra and the electromagnetic field distribution were investigated. The results showed a good agreement with the experimental data obtained earlier.
Synthesis of SiO2@Ag core-shell photonic crystals for SERS application
Authors: Ashurov M S , Eremina E A , Abdusatorov B A , Klimonsky S O
Published: December 2019

Core-shell SiO2@Ag composite spheres with dense, complete and nanoscaled silver shell were prepared by using facile chemical reduction method. Self-assembly of the composite microspheres into 3D photonic crystals (PhCs) was carried out using the vertical deposition method. The core-shell PhCs composites were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), UV-Vis spectroscopy and energy dispersive X-ray spectroscopy (EDX). The results of amplification of Raman scattering by these composite substrates are presented.
Electron-microscopy study of ordered silver nanoparticles synthesized in a ZnO:Al polycrystalline film
Authors: Sokura L A , Shirshneva-Vaschenko E V , Kirilenko D A , Snezhnaia Zh G , Shirshnev P S , Romanov A E
Published: December 2019

The optical absorption spectra and structural properties of samples series consisting of AZO oxide films with an intermediate layer of silver nanoparticles with different sol compounds were investigated. TEM analysis of the obtained coatings showed that the nanoparticles in the AZO film form an ordered structure, and the distance between them depends on the sol composition and the film annealing temperature. Optical measurements showed that a position of the nanoparticle plasmon peak in AZO also depends on them.
Investigation of functional properties of metal surfaces after laser treatment
Authors: Ruzankina J , Vasiliev O , Tarasov S
Published: December 2019

This article presents the results of the study of the processes of formation of the metal surface, which has different hydrophysical properties and high chemical resistance to acidic media. The dependence of the contact angle of the surface (θ) on various parameters of laser processing material, the density of arrangement of the scanning vectors, the depth of the heated layer, the presence of oxide layer, etc. Determined optimum modes of laser processing, with which it is possible to obtain the greatest hydrophobicity, and maximum adhesion to the metal surface.
The relationship of the geometric parameters of the surface with its properties (optical, emission, tribological)
Authors: Vasiliev O , Ruzankina J , Tarasov S
Published: December 2019

This article presents the results of the possibility of manufacturing different types of microstructures. Special surface microreliefs have been created to solve a number of important problems related to the functional properties of the object surface and its relationship with the environment.
Monitoring of oil paintings by means of optical 3D scanning
Authors: Zhuravlev A A , Parfenov V A
Published: December 2019

A novel technique of monitoring of painted surfaces is proposed. Experimental results concerned with use of optical 3D scanning for monitoring of oil paintings are presented. One of oil paintings with collection of The Military-Historical Museum of Artillery, Engineer and Signal Corps (St. Petersburg, Russia) was scanned by means of optical 3D scanner, which operates using structured light. The scanning was carried out 2 times with time interval of 4.5 years. In both cases we created computing 3D models of the same painting. These models were compared using software GeomagicStudio that allowed to get a precise quantified information about deformations of canvas and frame of painting.
The impact of terahertz chiral metasurface resonator rotation on polarization properties of transmitted wave
Authors: Masyukov M. S. , Vozianova A V , Grebenchukov A N , Khodzitsky M K
Published: December 2019

In this paper the influence of one and two chiral metasurfaces on polarization of the transmitted wave has been studied. The numerical simulation in CST Microwave Studio confirms the influence of the resonator rotation in the unit cell on polarizing properties of the metasurface. The ability of changing the polarization of the terahertz wave by two layers of such metasurfaces was shown. Thus, such metasurface can be used in development of mechanically-tunable polarization converter.
Tamm plasmon structure with an optical Fibonacci lattice coating
Authors: Gubaydullin A R , Morozov K M
Published: December 2019

We have theoretically investigated a Tamm plasmon structure covered by subwavelength grating with quasicrystal symmetry using a finite element method. The possibility to support a number of high-Q hybrid optical eigenstates in such systems was demonstrated. The model structure consists of a GaAs/Al0.95Ga0.05As Bragg reflector covered with a F
6 subwavelength Fibonacci silver/PMMA coverage. The considered system with a quasicrystalline grating has interesting properties and can be used as light filtering and emission amplifying components of optoelectronic systems.
Coupling of plasmon and grating resonances for SERS enhancement
Authors: Scherbak S A , Babich E S , Reduto I V , Lipovskii A A
Published: December 2019

We used thermal poling structuring of glass samples followed by chemical etching and subsequent out-diffusion growth of silver nanoparticles to fabricate periodic arrays of grooves etched in the glass with silver nanoparticles at their bottom. A numerical modeling of optical properties of these periodic structures was performed. We demonstrated that they support both plasmon and grating resonances, which interaction provides additional enhancement of an incident electric field. This can increase surface-enhanced Raman scattering by such biresonant structure.
Advanced aperture cantilevers made by focused ion beam for both magnetic domain structure and morphology investigation in high resolution magneto optical microscopy
Authors: Vysokikh Yu E , Krasnoborodko S Yu , Kolomiytsev A S , Fedotov A A , Shaposhnikov A N , Bulatov M F , Churikov D V , Shevyakov V I
Published: December 2019

Magneto-optical microscopy is a well-known and widely used method of magnetic domain structure investigation. Spatial resolution is limited by diffraction limit of the light and practically not exceed 0.5μm. Possibility to overcome diffraction limit by combination of magneto-optical microscopy and magnetic-force microscopy was showed earlier [1]. Aperture cantilever was used to light up the sample in near-field mode. In this paper, authors review most popular technology for aperture cantilever production with its advantages and disadvantages. Authors propose new technology based on focused ion beam treatment for creation aperture cantilevers with advanced parameters such as small aperture size and light throughput. Bi-substituted yttrium iron garnet (Bi: YIG) thin films with high magneto-optical activity and different period of domain structure were used as test objects. High resolution images of both morphology and domain structure obtained with new advanced aperture cantilevers are shown.
Magneto-optical properties of terbium-doped metaphosphate and borate glasses
Authors: Kulpina E V , Babkina A N , Fedorov Y K
Published: December 2019

The paper shows the results of Faraday Effect study of borate and metaphosphate glasses doped with various concentrations of terbium under uniform longitudinal magnetic field. The Verdet constant of glass under study is obtained based on the experimental data for several wavelengths. The optical and spectral properties of glasses are also studied.
Developing of normally-off p-GaN gate HEMT
Authors: Kukhtyaeva O B , Egorkin V I , Zemlyakov V E , Kapaev V V , Zaitsev A A , Tsatsulnikov A F , Nikolaev A E , Sakharov A V
Published: December 2019

In this paper, the high electron mobility transistor (HEMT) with p-GaN gate is developed. The article demonstrates development of normally-off p-GaN gate HEMT on heterostructure with AlN stop layer for p-GaN selective etching and formation of normally-on GaN HEMT on the same wafer. It is researched that the gate length and gate-to-drain length influence on transistor operation and its breakdown voltage. The ohmic contact resistance and leakage currents depend on etching RF mode. The developed normally-off transistor with gate length of 1 um and gate-to-drain length of 9.5um has a breakdown voltage of 500 V and drain current in open state of 350 mA/mm. It is established that 2 nm SiN under the gate metal influence on device work.
Determation of dV/dt values for domestic SiC Schottky diodes
Authors: Sedykh S V , Rybalka S B , Drakin A Yu , Demidov A A , Kulchenkov E A
Published: December 2019

In this study the dV/dt values for 4H-SiC commercial diodes have been determined experimentally. The experimental measuring tester for determination of dV/dt values of diodes at amplitude of impulse of reverse voltage VA (VA=100÷950 V) applied across the Schottky diode was constructed. It was determined that the dV/dt value almost linearly increase with increase of impulse of reverse voltage VA (in interval of VA=100÷900 V) applied across the 5DS402A9 diode for the first time. It is determined experimentally that at the maximal impulse of reverse voltage (900 V) applied across the silicon carbide commercial 5DS402A9 diode produced by domestic company the dV/dt value (148 V/ns) is comparable with others commercial diodes and therefore diode of this type can stably function in electric power circuit.
Peculiarities of the electronic transport in topological materials of Bi2Se3 and MoxW1-xTe2 (x = 0; 0.5; 1)
Authors: Chistyakov V V , Domozhirova A N , Huang J C A , Naumov S V , Marchenkov V V
Published: December 2019

The electrical resistivity of thin films of a topological insulator of Bi2Se3 with a thickness of 10 nm to 75 nm, single crystal of Bi2Se3 with thickness of 0.65 mm and single crystals of topological Weyl semimetals MoxW1-xTe2 (x = 0; 0.5; 1) in the temperature range from 4.2 to 300 K was measured. A size effect in the electrical conductivity of Bi2Se3 films was observed, i.e. linear dependence of the conductivity of the film on its reciprocal thickness. It is suggested the existence of two different conduction channels in the Mo0.5W0.5Te2 compound.
Effect of oxygen on the properties of Ga2O3:Si thin films
Authors: Almaev A V , Chernikov E V , Kushnarev B O , Yakovlev N N
Published: December 2019

The results of studies of electrical and gas-sensitive characteristics of thin films Ga2O3:Si on exposure to oxygen in the range from 0 to 100 vol. % and operating temperatures from 25 to 700 °C were presented. Samples were obtained by HF magnetron sputtering. The possibility of developing low-temperature oxygen sensors was shown. A model of oxygen interaction with Ga2O3:Si films was proposed. The mechanism of Si influence on gas-sensitive properties of thin films of gallium oxide was proposed.
The effect of ion implantation and annealing on forming process in Al2O3/HfO2/Al2O3 memristor structure
Authors: Permyakova O O , Miakonkikh A V , Rudenko K V , Rogozhin A E
Published: December 2019

In this paper, we study the effect of annealing and plasma immersion ion implantation of He+ conditions on forming voltage for the Al2O3/HfO2/Al2O3 memristive structures. Planar memristor structures were obtained by PEALD. It was shown that He+ implantation and annealing lead to decrease of forming voltage but also increase the dispersion of the set voltage of the memristive structures.
The influence of star-like palladium nanocrystallites on the gas transport parameters of modified palladium-containing membranes
Authors: Petriev I
Published: December 2019

Methods to modify the surface of Pd-23% Ag alloy films were developed in order to increase the velocity of hydrogen transmission; we obtained palladium coating of “nanostars” and “nanopores” type. Modification of Pd-Ag films surface, obtained by nanostars palladium coating makes it possible to achieve a hydrogen flow density of 0.76 mmol / (s*m2), which is 1.6 times greater in comparison with modification by “nanopores” coating under low temperature (<90 ° C) and pressure (<0.6 MPa) conditions.
Effect of crystal orientation on the implant profile and resistance of SiC
Authors: Egorkin V I , Nezhentsev A V , Zemlyakov V E , Gudkov V A , Garmash V I
Published: December 2019

The process of ion implantation into silicon carbide is studied in this paper. We conducted an analysis of acceptor distribution profiles. We determined that silicon carbide layers with an orientation (11–20) have a higher degree of crystal lattice recovery after ion implantation with aluminum ions than a crystal lattice with an orientation (0001). A significantly higher efficiency of ion doping of silicon carbide with an orientation (11–20) was shown, which may indicate a more efficient recrystallization of the fastest growing crystallographic direction. We have established a higher degree of restoration of the crystal lattice of silicon carbide implants with an orientation (11–20) after implantation. Highly doped SiC p-layers were obtained with a specific resistance of about 0.02 Ohm*cm and with high crystalline structure quality without the use of ultra-large implantation doses. The minimum value of Rs for orientation (0001) is about 10 k Ω/□, and for orientation (11-20) - 2.7 k Ω/□.
Study of plates with a combined “steel base – (titanium, oxide) coating” structure and preliminary tests of its wear resistance
Authors: Egorov I , Fomin A
Published: December 2019

This paper presents the results of the study of plates with a combined “steel base – titanium, oxide coating” structure, which was obtained by resistive welding and strengthening induction heat treatment. The data of measurements of hardness and preliminary test for wear resistance were given. The possibility of finishing turning on structural chromium steel X40Cr13 was shown.
The results of modelling of a micromechanical accelerometer
Authors: Lysenko I E , Ezhova O A , Tkachenko A V , Naumenko D V , Guha K , Rao K S
Published: December 2019

This theses the linear acceleration sensor design with three axis of sensitivity is researched. Parameterized geometry and finite element model for modal analysis are developed in the ANSYS program. Behavioral description of the study design is developed with language VHDL-AMS to simulate the sensor operation under the influence of linear acceleration along three axis of sensitivity. On the basis of research results three-axis device sensitivity, cross-sensitivity, duration transients are specified. As part of the work the experimental sensor prototypes are fabricated.
Sensitive elements of microelectronic sensors of fast variable and static pressure
Authors: Fimin A. V. , Gurin S. A. , Pecherskaya E. A. , Golubkov P. E. , Kozlov G. V. , Kraynova K. Y.
Published: December 2019

The technical progress development contributes to the introduction of automated methods of management and control of the system state. The use of sensor equipment with the use of piezoelectric tensor-resistive modules allows to register fast variable and statistical pressure, respectively. Such assemblies possess not only the most reliable information content of the measured values, but also combine simple step-by-step manufacturing techniques.
Investigation of resistive switching in gallium oxide nanostructures formed by local anodic oxidation
Authors: Tominov R V , Polupanov N A , Avilov V I , Solodovnik M S , Parshina N V , Smirnov V A , Ageev O A
Published: December 2019

Effect of resistive switching in gallium oxide structure was studied. It was shown, that gallium oxide structure, formed by local anodic oxidation, demonstrated resistive switching from high-state resistance (HRS) to low-state resistance (LRS) at +4 V, and from LRS to HRS at -6V. RHRS, RLRS, RHRS/RLRS were equaled 11.7±1.6 GΩ, 2.3±0.8 GΩ and 5, respectively. Homogeneity test showed, that RHRS and RLRS were equaled 10.6±2.8 GΩ and 2.5±1.7 GΩ, respectively. It was shown, that confidence interval of resistive switching effect of endurance test for HRS is less on 42% and for LRS is less on 53%, than for homogeneity test So, it was shown that the obtained gallium oxide structure has a uniform effect of resistive switching within 15 measurements. The results can be useful for based on gallium oxide neuromorphic system manufacturing.
Simulation of hopping in disordered fractal arrays of graphene quantum dots
Authors: Morozova Ekaterina
Published: December 2019

Diffusion regimes of charge carriers in artificial quasi-fractal graphene quantum dot (GQD) superlattices forming hexagonal and triangular carpet are investigated. Using the generalized Miller-Abrahams relations for hopping rates we perform Monte Carlo simulation of charge carrier hopping in artificial 2d disordered arrays of armchair GQDs. The variations of the anomalous advection-diffusion parameters as functions of localization radius, electric field intensity, levels of energetic and structural disorder are studied.
Study of the features of ultrafast silicon-carbide current switch for sources of soft x-ray radiation based on capillary plasma
Authors: Serguschichev K A , Smirnov A A , Ilyin V A , Afanasyev A V , Samokhvalov A A , Timshina M V , Eliseev S I
Published: December 2019

The results of the development and experimental investigation of high-voltage silicon-carbide high-speed current switches – drift step recovery diodes (DSRD) – and their implementation as a part of soft X-ray source based on capillary plasma are presented.
The method of improving the parameters of the microwave excitation signal in the rubidium – 87 quantum frequency standard
Authors: Valov A P , Davydov V V , Rud V Y
Published: December 2019

This article discusses the design of the rubidium – 87 quantum frequency standard for satellite navigation systems. Also it is proposed a method for improving the parameters of the microwave excitation signal to improve the short-term and long-term stability of the frequency standard. The results of experimental research are presented.
Development of subwavelength diffractive optical elements manufacturing process for photonic devices
Authors: Fomchenkov S A , Porfirev A P
Published: December 2019

Subwavelength diffractive optical elements with characteristic dimensions close to the wavelength can implement interesting optical functions, replacing, advantageously, other structures with dimensional features much smaller than the wavelength. The fabrication process becomes easier and the performance is better controlled. A study of a subwavelenght DOE manufacturing process with use of available technologies will be presented.
Identification of Phase CaCO3/MgO in Bangkalan Dolomite Sand as An Antibacterial Substance
Authors: Rohmawati L , Sholicha S P , S Holisa SP , Setyarsih W
Published: December 2019

Dolomite sand has several ingredients such as CaCO3and MgO which have the potential as an antibacterial substance. The making of this antibacterial substance uses the heating/calcination method of dolomite powder with a variation of holding time from 0.5 to 2.5 hours at a temperature of 700°C. The nanoparticles produced from the calcination process were then characterized by XRD to identify the formed phase. This study aimed to determine the effect of holding time on phase formation on dolomite. The results of this study are identified as forming four phases namely calcite (CaCO3), periclase (MgO), calcium hydroxide (Ca(OH)2) and lime (CaO) with different percentages in each variation of holding time. The Ca(OH)2and CaO phases include the impurity phase with a lower percentage than the CaCO3and MgO phase percentages. The most dominant phase is CaCO3and the MgO phase formed optimally at 1 hour holding time with a percentage of 47.1% CaCO3and 35.9% MgO.
Solvent Effect on Viscoelastic Behaviour and Morphology of Polyaniline Coating at QCM Sensor
Authors: Putri N P , Pravitasari D W , Al Aziz F , Maulidiah  , Santjojo D J D H , Masruroh  , Sakti S P
Published: December 2019

The effect of different solvents and solution concentration on viscoelastic behaviour and morphology of polyaniline (PANi) coating was investigated in this study. The PANi coating on a QCM sensor was created by spin coating with various solvents, such as NMP, m-cresol, and DMF with varying concentrations of 1-4% by weight of PANi. The viscoelastic behaviour was observed by impedance analyser and morphology of the PANi coating was observed via optical microscope and SEM/EDX. The viscoelasticity was measured to determine whether the coating produces an acoustic load (loading effect). The observations showed that the different solvents give a different effect on the impedance value of the PANi coating. With m-cresol solvent, the impedance value in the series resonant frequency was so large, indicating the PANi coating was not rigid and produce a loading effect on QCM sensor. From morphology observation showed that homogeneity of the polyaniline coating is still poor. There is an agglomeration of polyaniline powder which is insoluble in the solvent used. From the viscoelastic properties of the coating, the optimum value was obtained in PANi coating with NMP solvent.
Spectral Approach to Modeling Dependence in Multivariate Time Series
Authors: Ombao Hernando
Published: December 2019

Consider a multivariate time series such as prices of stocks from various sectors, amount of rainfall in many geographical locations, and brain signals from many different locations on the scalp. The goal of this paper is to present the spectral approach to modeling dependence between components of the multivariate time series. There are many measures of dependence - the most popular being cross-correlation or partial cross-correlation. This measure is easy to compute and easy to understand but it coarse in a sense that it is not able to identify the underlying frequencies that are responsible for driving the dependence. In the stock price example, two stocks may be highly correlated but it would be helpful to see if this correlation is driven by the daily fluctuations or by millisecond-level fluctuations. In the neuroscience example, when two brain regions exhibit a high level of correlation, it will be important if this synchronicity is due to low-frequency oscillations or high-frequency oscillations. Here we present an overview of the underlying principles through specific spectral models which decompose the signals into oscillations of various frequencies and then model lead-lag dependence via these oscillations.
Subsampling Method for Big Data in Poisson Regression
Authors: Pradana A N I , Sofro A
Published: December 2019

Big Data is very large, too fast and complex that cannot be managed with traditional tools; and must use new methods and tools to process it. Subsampling method is one method that can be used to solve big data problems. This paper focuses on estimation in Poisson Regression using Maximum Likelihood Estimation (MLE). In this study, it will be discussed about the implementation of the Subsampling method of The Demand for Medical Care data. To understand the performance of subsampling method, the paper provided a scenario with different sample sizes. The results of this study obtained parameter estimates and Poisson regression models on each subsample. Based on the Akaike Information Criterion, the best model is providing the smallest value. From the scenario, the sample size of the subsampling which is close to sampling tend to have smaller value of AIC.
Hierarchical Clustering Algorithm Based on Density Peaks using Kernel Function for Thalassemia Classification
Authors: Hartini S , Rustam Z
Published: December 2019

Thalassemia is an inherited blood disorder and one of the most common genetic diseases in the world, with its classification due to the processes involved in patients’ treatment. Therefore, it is essential to obtain a precise diagnosis due to an appropriate treatment receives a higher lifetime value. A new method based on the kernel, modified from hierarchical clustering based on density peaks (HCDP) was proposed in this research. Furthermore, the concept of k-nearest neighbor and hierarchical clustering, consists of three steps were utilized. These steps include local density calculation, hierarchy representation, and optimal cluster extraction. The modification of this technique is therefore based on the polynomial kernel function, which was expected to be more accurate in separating data that cannot be detached linearly. Data utilized was obtained from Harapan Kita Hospital, West Jakarta, Indonesia, and it consists of 82 thalassemia and 68 non-thalassemia samples. Using the proposed method, the performance of HCDP with/without kernel function in this paper were examined using 10-fold cross-validation and compared using the confusion matrix by calculating its F1-Score. The results concluded that hierarchical clustering based on density peaks gives approximately 67.77 percent F1-Score, while 70.06 percent is obtained when the method is combined with the kernel function.
Comparison of Confidence Intervals for the TG Estimator in Capture-recapture Data
Authors: Anan Orasa , Kanjanasamranwong Preedaporn , Chantarangsri W. , Sofro A’yunin
Published: December 2019

Capture-recapture techniques are very powerful tool and widely used for estimating an elusive target population size. Capture-recapture count data is presented in form of frequencies of frequencies data. They consist of the frequency of unites detected exactly once, twice, and so on, and the frequency of undetected unites is unknown. As consequence, the resulting distribution is a zero-truncated count distribution. The binomial distribution is selected as a simple model if the maximum number of counting occasions is known. It counting occasions are not known in advance, the series of frequencies assumed to be the Poisson distribution. In fact, the target population might be heterogeneous because it has different characteristics, resulting in over or under dispersion based on the basic models. The mixed Poisson, which is the exponential-Poisson mixture model, have been widely used to construct population size estimator for capture-recapture data. The original Turing estimator provides a good performance under the Poisson distribution. Additionally, an extension of Turing estimator, called the Turing-based geometric distribution with non-parametric approach was proposed (TG) for the heterogeneous population. It gives an easy way to estimate the target population size. In this work, we derived uncertainty measures for the TG estimator by considering two sources of variance (M1), and the second way is using only one source of variance (M2). It is emphasised that although the analytic approaches to compute uncertainty measures can be easily used in practice, there are valid asymptotically and requires a large sample size. Therefore, re-sampling approaches, true bootstraps (M3), imputed bootstrap (M4) and reduced bootstrap (M5), are proposed as alternative methods to get uncertainty measures. The study compares performance of variance and confidence interval of paralytics and re-sampling methods by using a simulation study. Overall, the imputed bootstrap is the best choice for estimating variance and constructing confidence interval for the TG estimator. The analytic approach with two sources of variance remains successful to estimate variance and calculate confidence interval in the case of large. It is very clear that the reduced bootstrap and the analytic approach with one source of variance are not appropriate in all situations. For the true bootstrap, the true value of population size is often unknown in nature; therefore, it quite useless for capture-recapture study.
Modelling the Influence of Unhealthy Human Behaviour on the Spread of Zoonosis Disease that May Cause a Possible Future Pandemic
Authors: Sidik WA
Published: December 2019

This paper addresses some strategies to improve the quality of management system in the laboratories by presenting models and methods for analyzing the effect of un-healthy human behavior on zoonosis disease spread and possible future pandemic. The possible future pandemic is modelled by a hypothetical mutated virus as a result of virus recombination. The variability of seven disease states among anima and humans are described as deterministic processes and modeled in the form of a well-defined initial value problem. The epidemic model has six disease state equilibria of which four are globally asymptotically stable and the others are locally asymptotically stable. Analyses show that: (i) to control the spread of disease means to control the effective rate of disease transmissions (ii) containing the disease in the animal world does not stop the spread of the implicated diseases in the human world. (iii) the spread of the mutant virus has a bigger magnitude than original in terms of the proportion of individuals acquiring the disease. (iv) reducing the contact among the animals will reduce the spread of the disease in the animal and human population but not stop the spread of the mutant virus. (v) social distancing programs reduce the number of human casualties.
The Composition of Water and Ash of Secang Wood’s Simplicia and Secang Wood Herbal Drink Powder
Authors: Anggarani M A , Ayuningsih A D , Yudianto E , Prasodi B A
Published: December 2019

Empirically, secang wood (Caesalpinia sappan L.) has medicinal properties and is consumed as a health drink. Secang wood contains tannin, gallic acid, brazilin, tannic acid, essential oils, polyphenols and sappanin. Switching people’s tastes from consuming the basic form of sappan wood to a more attractive and practical form, which is an herbal drink that contains the properties. The secang drink is measured by water and ash content. Water content is related to the stability index while ash content about minerals is filled. The initial probability of the quality of the secang herbal drink can be compared with that of both aspects. The lower the water content in a product, the better the quality, the higher the stability which can be further improved during storage. While the higher the ash content, the higher the probability of mineral content. Based on the analysis of water content and ash content, it is known that the simplicia of the secang wood is 1.542% while the water content of the herbal drink powder is 0.266%. Meanwhile, based on the analysis of ash content, ash content of simplicia secang bark is 9,449% while the water content of herbal beverage powder is 0,009%.
Synthesis and Characterization of Collagen-Chitosan-Sodium Hyaluronates as Artificial Cornea
Authors: Widiyanti P , Rini N D W , Kirana M N , Astutik T
Published: December 2019

As reported by Riset Kesehatan Dasar, Indonesia facing a serious problem of blindness with 966.326 cases of 2 million population in 2013. Gold standard such as keratoplasty couldn’t completely heal corneal injury due to the recipient’s rejection and limited donor. In order to overcome those concerns, artificial corneal tissue needs to be developed to produce an artificial cornea which is biocompatible, supports corneal function, and applicable. This research was conducted to provide an initial description of Collagen – Chitosan - Natrium Hyaluronate (Col-Chi-NaHA) as an artificial cornea through FTIR analysis, hydrophilicity and water absorption measurement. The artificial cornea was synthesized by forming ratio of collagen 20% w/v and chitosan 10% w/v, both solutions were dissolved in 0,1 M and 0,6 M acetic acid separately. Into the mixed solution, NaHA was dripped slowly with variation of 0%, 0,3%, and 0,6%. The homogenous solution was cast and heated for 24 hours at 35°C. The dry membranes were neutralized to obtain a pH around 7. From the analysis known that all of the characteristic bands of Col-Chi-NaHA could be observed in obtained membranes. Water absorption measurement demonstrated percentages over 90% on all membranes. The contact angle of obtained membranes was decreased by the addition of NaHA. The results showed that artificial cornea made from Col-Chi-NaHA successfully fabricated has hydrophilic properties to support cellular interaction and provide hydration to keep eye’s clarity and permeability. Therefore, Col-Chi-NaHA could may be a suitable material for the tissue-engineered cornea.
Identification and Exploration of Elementary School Teacher Misconception in Mathematical Learning
Authors: Rahaju E B , Iriyani D , Artiono R
Published: December 2019

Mathematics is one of the compulsory subjects that must be taught to students at all levels of education. It creates students not only to have the ability to think logically, critically, analytically, creatively, and meticulously, but also carefully develop the ability to use mathematics in problem solving. Therefore, mathematics teachers are required to convey mathematical concepts correctly. Unfortunately, there are some elementary school teachers whose understanding of the concepts in mathematics learning is incorrect. The aim of this study was to identify the misconception of elementary school teachers in mathematics learning. This type of research was descriptive-qualitative research, where data had been analysed qualitatively. The research data were in the form of interviews and observations of the subjects, namely elementary school teachers in Sidoarjo district. Regarding to the data, there were several misconceptions in elementary school teachers, consisting of 1) Defining the apex point of the cone as the angle formed by the curved side; 2) Defining a cone surface as a side; 3) Defining a cylinder surface as a side, and 4) Defining the cone as a pyramid.
The Influence of Cognitive Style on Mathematical Communication of Prospective Math Teachers in Solving Problems
Authors: Budayasa I K , Juniati D
Published: December 2019

Communication is important to connect with others. It is one of the important aspects that must be mastered by the prospective math teacher as a tool of knowledge transfer. They are expected to have good mathematical communication skills to facilitate them in the mathematics learning process. Problem-solving in learning mathematics is something that cannot be ignored. Through problem-solving, students can have a better understanding of concepts because through mathematical problem solving, and students are required to be more active in using the concepts they have in a variety of new situations encountered. FD/FI cognitive style is the extent to which a person perceives parts of a field discrete from the surroundings rather than embedded in it as a whole. Based on differences from cognitive style, it certainly affects the way of communication, especially mathematical communication. So, the aim of this research was exploration the mathematical communication of prospective math teacher in solving problem viewed from FI/FD cognitive style. This type of research was descriptive research with a qualitative approach. The subjects of this research were 86 prospective math teachers. Data were collected through tests, assignments, and task-based interviews. The results of this study indicated that mathematical communication from FD and FI students were not different when solving routine problems, but were different when solving non-routine problems, which require strategy and decision making. FD students had difficulty communicating their strategies clearly and coherently. Meanwhile, FI students explained the strategies they used in more detail.