bluuebunny/crossref_metadata_2025 huggingface dataset:
Features of formation of Langmuir monolayers of porphyrin derivatives on the surface of aqueous solutions of copper nanoparticles
Authors: Begletsova N N , Mironyuk V N , Ezhov A V , Smirnova A I , Usol’tseva N V , Glukhovskoy E G
Published: December 2020

Meso-aryl-substituted porphyrin monolayers were obtained by the Langmuir method depending on the aliquots applied to the water surface and the composition of the subphase. Regardless of the composition of the subphase (pure water or a solution with copper nanoparticles stabilized by surfactant) porphyrin compression isotherms showed the formation of monolayers until a film collapse state is reached. The presence in the subphase volume of copper nanoparticles stabilized by a surfactant (sodium dodecyl sulfate) contributed to the formation of a more stable porphyrin monolayer. A significant difference in the values of the surface potential at the end of porphyrin monolayer compression depending on the composition of the subphase is established. This fact is very promising in the context of creating film heterostructures with improved operational properties.
The effect of anodization current density on the functionalization of porous silicon nanoparticles with an antibiotic
Authors: Sattorov M Sh , Spivak Yu M , Gavazyuk N O , Panov M F
Published: December 2020

The influence of the anodization current density to the morphology and composition of the surface of porous silicon before and after its impregnation with an antibiotic was investigated using atomic force microscopy and IR spectroscopy. Layers of porous silicon were obtained by electrochemical etching; variable technological parameters of anodizing were the current density and the type of conductivity of the silicon plate. The results obtained are discussed in terms of their use in targeted drug delivery.
Study on the parameters of the microporous structure of zeolite compositions by sorption analysis methods
Authors: Maraeva E V , Kononova I E , Adamovich D S , Tokmeilova S , Skornikova S A , Moshnikov V A
Published: December 2020

The work is devoted to the study on the influence of various factors on the microporous structure parameters of the zeolite compositions being formed. To study the parameters of the microporous structure, sorption analysis methods were used. Zeolites of the BETA type and compositions based on them were chosen as objects under study. It was found that the formation of zeolite compositions is greatly influenced by the nature of the binder (matrix) and peptizer, which determine the proportion of micropores in the zeolite composition. It is shown that in the study of the textural characteristics of zeolite compositions, preliminary sample preparation (heat treatment to remove the moisture adsorbed by them) is necessary.
One-step electrochemical synthesis of Ag/por-Si composite from monocrystalline Si
Authors: Spivak Y M , Gagarina A Y , Portnova M O , Zaikina A V , Moshnikov V A
Published: December 2020

The technique of obtaining Ag/Por-Si composite material with homogeneously distributed silver nanoparticles over the surface of porous silicon by one cycle of electrochemical treatment of single-crystalline silicon. The effect is achieved by using an electrolyte to produce porous silicon with a special composition containing silver ions. During the electrochemical anode treatment of single-crystalline silicon in Ag-containing electrolyte a layer of porous silicon and silver islets are formed on the sample surface simultaneously. It is shown that the controlling the conditions of electrochemical processing provide an opportunity to form homogeneously distributed on the surface silver nanoparticles with a narrow-size distribution.
Structural and optical properties of quasi-2D GaTe layers grown by molecular beam epitaxy on GaAs (001) substrates
Authors: Avdienko P S , Kolyada D V , Firsov D D , Komkov O S , Sedova I V , Sorokin S V
Published: December 2020

Quasi-two-dimensional GaTe layers were grown by molecular beam epitaxy on GaAs (001) substrates at Ts
= 450–520°C. The effect of the growth temperature on the GaTe surface morphology has been studied by scanning electron microscopy. It is shown that GaTe layer grown at high Ts
= 520°C exhibits pronounced surface relief anisotropy. This sample demonstrates also near band-edge photoluminescence (PL) at T = 11K with the peak energy of ∼1.72 eV, which can be associated with the emission of excitons bound at the acceptor. The nature of 1.45 eV and 1.57 eV peaks appearing in the PL spectra is also discussed in detail.
Magnetization and electron spin resonance of a carbon/polymer composite
Authors: Ionov A N , Volkov M P , Semenikhin P V , Nikolaeva M N
Published: December 2020

It has been shown that in multilayer graphene/polystyrene composite, the static magnetization curve looks the same as in a type-II superconductor. The electron spin resonance in the same composite was studied as a function on temperature and magnetic field. The observed g-factor of 2.003 was independent of temperature and was in the range (g = 2.0022-2.0035) characteristic of a free carbon electron. This behavior of the g-factor excludes the appearance of an internal magnetic field in the composite.
Frequency shifts of the magnetic resonance of Rb and K atoms in the K-Rb tandem magnetometer
Authors: Kartoshkin V A
Published: December 2020

Collisions of alkali atoms in the ground state are accompanied by the exchange of electron polarization between the colliding atoms, which lead to the polarization transfer between particles. As a result of this process, the electronic orientation is transferred from the spin oriented atoms to unpolarized atoms, along with the polarization transfer, the magnetic resonance frequency shifts of polarized atoms occur too. In this work the magnetic resonance frequency shifts of arising from spin exchange collisions in a mixture of alkali potassium and rubidium atoms at the optical orientation of atoms are calculated. The situation when optical pumping by resonant polarized radiation is carried out only for atoms of the one kind is considered. The spin exchange process between alkali atoms was described in the formalism of the complex cross section for spin exchange process. The real and imaginary parts of the complex cross section were calculated using the interaction potentials of alkali atom dimers. The calculation of the frequency shifts is carried out on the basis of data on the interaction potentials for the following pairs of alkali atoms K-K, K-Rb and Rb-Rb. Maxwell averaging of the cross sections over the velocities was done and the temperature dependences of the magnetic resonance frequency shifts for K and Rb atoms were plotted.
Optical reflection spectra of resonant photonic structures based on a system of 100 InGaN quantum wells
Authors: Ivanov A A , Chaldyshev V V , Zavarin E E , Sakharov A V , Lundin W V , Tsatsulnikov A F
Published: December 2020

The optical reflectance and transmittance spectra of a periodic InGaN semiconductor heterostructure with 100 quantum wells are studied at room temperature. Numerical modeling with a single set of parameters gave a quantitatively accurate fit of the experimental reflection and transmission spectra in a wide wavelength range. The radiative decay parameter is determined to be 0.25 meV and the nonradiative decay parameter is 40 meV.
GaPN/GaP nanowire-polymer matrix: photoluminescence study
Authors: Koval O Yu , Fedorov V V , Bolshakov A D , Neplokh V V , Strom I V , Serov A Yu , Mukhin I S
Published: December 2020

This study is devoted to the investigation of the optical properties and composition of GaPN/GaP nanowire heterostructure. Nanowire arrays were grown on Si substrate (111) by the plasma-assisted molecular beam epitaxy. Polydimethylsiloxane membrane encapsulation was used to obtain the free-standing NW arrays. The morphology of GaPN/GaP NW was investigated with scanning electron microscopy. The optical properties of the GaPN nanowire arrays were determined at the He temperature (5K) with photoluminescence spectroscopy. Analysis of photoluminescence response allowed us to conclude that the incorporation of nitrogen atoms during the growth occurs both in the nanowires and in the parasitic islands with different content. Direct bandgap-like behaviour of the GaPN/GaP nanowires demonstrates the potential of nanowire-polymer matrix practical application in future optoelectronic devices.
Raman spectra of folded acoustic phonons in short-period GaN/AlN superlattices as a tool for structure characterization
Authors: Davydov V Yu , Roginskii E M , Kitaev Yu E , Smirnov A N , Eliseyev I A , Nechaev D V , Jmerik V N , Smirnov M B
Published: December 2020

The results of experimental and theoretical studies of phonon modes in short-period GaN/AlN superlattices grown by PA MBE on the (0001) Al2O3 substrate are reported. In the framework of Density Functional Theory and Elastic Continuum Model the lattice dynamics properties are studied of (GaN)m(AlN)n SLs (m+n≤24), where n and m are the number of monolayers. Good agreement between experiment and theory is found, which made it possible to establish unambiguously a relationship between the features observed in the Raman spectra and the microscopic nature of the acoustic phonon modes. The obtained results open new possibilities for analyzing the structural properties of GaN/AlN SLs by Raman spectroscopy.
Influence of Mach-Zehnder modulator bias point on chaotic dynamics in spin-wave optoelectronic oscillator
Authors: Kondrashov A V , Ustinov A B , Kalinikos B A
Published: December 2020

In this paper we investigate in details the scenario of a transition to chaos in the spin-wave optoelectronic oscillator. The feature of the investigated circuit is the presence of two nonlinearities with different nature – modulation instability of spin waves and nonlinearity of the transmission characteristic of the electro-optical modulator. The influence of a position of the modulator bias point on the scenario of chaos development is experimentally investigated.
Application study of ultra high frequency modulation of laser radiation for fiber-optic gyroscope noise reduction
Authors: Vostrikov E V , Smirnov D S , Nikiforovskii D A , Pogorelaya D A , Aleinik A S
Published: December 2020

Microwave photonics is implemented in many applications, including the area of inertial navigation systems based on high-precision fiber-optic gyroscopes. Microwave photonic technologies allow increasing the fiber-optic gyroscope accuracy. This paper investigates and evaluates the effect of ultra high frequency modulation of laser radiation on the closed-loop fiber-optic gyroscope output signal. Research results show that ultra high frequency modulation makes it possible to broaden spectrum width due to redistribution to modulation harmonics of the laser radiation. This approach allows to reduce the standard deviation of the laser-driven fiber-optic gyroscope output signal more than 2.5 times compared to using a laser-driven fiber-optic gyroscope without modulation. In order to achieve the noise level of a laser-driven fiber-optic gyroscope the same as the noise level of a fiber-optic gyroscope with a broadband source, it is necessary to use a broadband noise source with a constant power spectral density and higher output power. This study is useful for understanding how application of microwave photonic technologies can impact on the fiber-optic gyroscope output signal. The obtained results can be used for researchers in this area of study and can facilitate the rapid development of this field.
Time-frequency analysis of acoustic waves in an integrated acousto-optical modulator based on LiNbO3
Authors: Varlamov A V , Ivanov S I , Lavrov A P , Shamray A V
Published: December 2020

The work presents a method allowing calculating the input admittance of an acousto-optic modulator with XY-cut lithium niobate substrate for a specific interdigital transducer structure is presented. The method does not require complex numerical computations and is sufficiently accurate. The method is based on the information about the pole of a Green’s function for a given piezocrystal. A method of measuring parameters and finding the types of the excited acoustic waves based on joint time-frequency analysis using modern vector network analyzers is also presented. Good correlation between theoretical and experimental investigation is demonstrated.
Optically pumped non-zero field magnetometric sensor for the magnetoencephalographic systems using intra-cavity contacted VCSELs with rhomboidal oxide current aperture
Authors: Bobrov M A , Blokhin S A , Maleev N A , Blokhin A A , Vasyl’ev A P , Kuzmenkov A G , Pazgalev A S , Petrenko M V , Dmitriev S P , Vershovskii A K , Ustinov V M , Novikov I I , Karachinskii L Ya
Published: December 2020

We demonstrate the possibility of using vertical-cavity surface emitting lasers with intracavity contacts and a rhomboidal oxide current aperture for creating compact optically pumped 133Cs atomic magnetometer operating in non-zero magnetic fields, which is promising to use in magnetoencephalographic systems. The magnetic resonance parameters were studied in a two-beam MX optically pumped magnetic field sensor scheme based on the effect of the magnetic resonance line narrowing at high laser pumping and high concentrations of alkali-metal atoms. The ultimate sensitivity of OPM was estimated by the ratio of the magnetic resonance steepness to the probe light shot noise level. It is shown that a magnetic sensor based on the vertical-cavity surface emitting lasers and a compact (0.125 cm3 volume) Cs vapor cell can achieve a shot noise-limited sensitivity better than 15 fT in 1 Hz bandwidth. Developed intracavity contacted VCSELs suitable for use in compact atomic magnetometers for magnetoencephalographic systems.
Design of electrically driven single photon source based on dielectric passive cavity structure at 1.3 μm
Authors: Blokhin S A , Bobrov M A , Maleev N A , Blokhin A A , Vasyl’ev A P , Kuzmenkov A G , Shchukin V A , Ledentsov N N , Reitzenstein S , Ustinov V M
Published: December 2020

A combination of advanced concepts is applied for designing micro-cavity structures aimed for single-photon sources with high photon-extraction efficiency in the telecom O-band at ~1.3 μm. The device design consists of a broad stop-band bottom distributed Bragg reflector (DBR), a top DBR formed in a dielectric micropillar with additional circular Bragg grating and a central dielectric passive cavity. This combination of photonic elements is compatible with electric carrier injection and provides overall photon-extraction efficiency of ~83% as shown by 3D finite-difference time-domain simulations.
Charge transfer mechanisms in multistructured photoelectrodes for perovskite solar cells
Authors: Vildanova M F , Nikolskaia A B , Kozlov S S , Shevaleevskiy O I
Published: December 2020

Here we introduce the research studies of perovskite solar cells with multistructured photoelectrodes based on very wide bandgap nanocrystalline materials. A series of solar cells with the device architecture FTO/c-TiO2/ZrO2(HfO2)/CH3NH3PbI3/Spiro-MeO-TAD/Au was fabricated and characterized. The results obtained demonstrate a successful possibility of PV application of the nanostructured oxide materials with bandgap values exceeding 5 eV. We propose a mechanism, which describes charge carrier transport at the interface of perovskite/multistructured photoelectrode.
Tuning of laser power converters efficiency by means of temperature
Authors: Shvarts M Z , Emelyanov V M , Malevskiy D A , Mintairov M A , Mintairov S A , Nakhimovich M V , Pokrovskiy P V , Salii R A , Kalyuzhnyy N A
Published: December 2020

The results of studying the InxGa1−xAs laser power converters with the indium percentage of 18% and of 23% are presented. In the mode of 1064 nm laser radiation conversion the photovoltaic parameters dynamics with raising temperature is discussed.
Study of Latex sphere mask dry etching in oxygen
Authors: Morozov I A , Vyacheslavova K A , Gudovskikh A S , Uvarov A V , Baranov A I , Kudryashov D A
Published: December 2020

Nanosphere lithography is well suited for quick and easy formation of ordered structures on the entire silicon wafer. After coating of close packed mask of spheres, they must be reduced in diameter. In various studies, the main method used for spheres diameter reducing is dry etching using capacitively coupled plasma (CCP) mode. In this paper, we present the possibility of spheres etching using inductively coupled plasma (ICP) mode, comparing the results obtained with CCP mode. A strong degradation of the spheres morphology was demonstrated at CCP mode, while the degradation effect was not sufficient using ICP mode. However, the effect of spheres migration over the silicon surface during ICP etching was observed. A preliminary thermal annealing of spheres allows one to avoid this effect. Finally, a technology of reducing the spheres size with minimal degradation and preserving the original spherical geometry was developed.
The spin-filtering properties in two coupled Rashba quantum rings
Authors: Smolkina M O , Popov I Yu , Blinova I V
Published: December 2020

The spin-dependent electron transport in two coupled quantum rings with Rashba spin-orbit interaction and magnetic flux was studied by using quantum graph approach. We show the dependence of spin-polarization on system parameters such as the Rashba coupling constant, the radius of the rings, the angles between the leads and the attachment point of the rings. The spin-polarization can be controlled and changed from -1 to +1 by using a magnetic flux. Also it was shown that this model is a limiting case of double Rashba quantum ring when the length of the middle lead between rings vanishes.
Irreversibility field and anisotropic δl-pinning in type II superconductors
Authors: Guryev V V , Shavkin S V , Kruglov V S
Published: December 2020

The article presents a brief generalization of our recent experiments confirming that “irreversibility field” in Nb-Ti superconducting tapes is determined by the inhomogeneity of superconducting properties. It is shown that the effect is a direct consequence of the so-called δl-pinning, i.e. pinning caused by local reduction of the electrons mean free path. Based on the understanding of the irreversibility field nature, an assessment of the individual pinning force is performed. Good agreement is obtained with the estimations performed in the framework of the Larkin-Ovchinnikov pinning model (LO), which is valid for magnetic field less than the irreversibility field. The competing model is considered which is also valid for field range below the irreversibility field - the anisotropic pinning model (APM). The comparison of the fundamental length scales introduced in the LO and APM models is given.
Magnetic circular polarization of photoluminescence of an inhomogeneous ensemble of colloidal nanocrystals
Authors: Smirnova O O , Golovatenko A A , Rodina A V
Published: December 2020

In this paper, we theoretically analyze the recombination and spin dynamics of excitons in an inhomogeneous ensemble of colloidal nanocrystals, which consists of several subensembles with different lifetimes and degrees of circular polarization of exciton photoluminescence (DCP). Each subensemble is described within a three-level model of interacting exciton states, including two excited states and a ground state. Various ratios of parameters, leading to a nontrivial time-dependent DCP and a difference in the integral and equilibrium DCP characteristics, are considered. It is shown that the presence of subensembles with different polarizations and lifetimes results in nonmonotonic dependence and a change in the sign of the DCP in magnetic field and as a function of time can occur. The theoretical model was implemented to describe the time dependences of the DCP in ensembles of colloidal CdSe nanoplatelets synthesized in the air and argon atmosphere.
Influence of a constant field on a circular photovoltaic effect in two-dimensional superlattices
Authors: Konchenkov V I , Myachkova A A , Zav’yalov D V
Published: December 2020

Using the relaxation time approximation, an analytical expression was obtained for the direct current density arising in a two-dimensional superlattice when, in addition to two elliptically polarized waves, a constant field acts on the sample along one of the directions.
Influence of doping profile of GaN:Fe buffer layer on the properties of AlGaN/AlN/GaN heterostructures for high-electron mobility transistors
Authors: Arteev D S , Sakharov A V , Lundin W V , Zavarin E E , Zakheim D A , Tsatsulnikov A F , Gindina M I , Brunkov P N
Published: December 2020

The effect of the Fe doping profile of the GaN buffer layer in the heterostructures for high-electron mobility transistors was studied experimentally and by computer simulation. The exponential Fe tail extending to the nominally undoped layers may greatly affect the properties of the structure. Reducing the distance between the channel and the Fe-doped buffer to less than 1 μm results in a decrease in the density and mobility of the two-dimensional electron gas. It also leads to the higher off-state avalanche breakdown voltage and reduced leakage current. A good agreement between simulation and experimental data is obtained when taking into account a Fe segregation effect, while an abrupt doping profile lead to significant discrepancies between them
Steady-states of relativistic Pierce diode in a regime with electron reflection from a potential barrier
Authors: Gerasimenko A B , Kuznetsov V I
Published: December 2020

In this work we present the study of steady states of a relativistic Pierce diode. We take into account electron scattering by heavy background ions as well as electron reflection from a potential barrier. Using Lagrangian variables we solve the problem numerically. Steady-state solutions are visualized through the ‘Bursian’ and ‘Non-Bursian’ branches in a parametric plane. Features of these branches with varying in mean collision frequency are analysed.
Studies of terahertz discharge in noble gases using a Michelson interferometer
Authors: Barmashova T , Luchinin A , Murzanev A , Sidorov A , Stepanov A , Veselov A , Vodopyanov A
Published: December 2020

The measurements of the spatial-time evolution of the discharge in argon and krypton at a wide range of pressures were performed. The gyrotron was used for plasma ignition. The radiation was 40 kW with frequency 0.67 THz. The pulse duration was 20 μs. A Michelson interferometer has been exploited for investigation of the discharge in the noble gases in a focused beam of terahertz waves. The diameter of the laser beam near the plasma cloud was 25 mm at 1/e
2 level, λ = 532 nm. The rectangle area (about 20 × 15 mm) near the focus of THz beam was examined synchronously by the interferometer and a CCD camera. The spatial-time evolution of laser beam phase-shift of THz discharge in Kr and Ar from atmospheric pressure down to a few torrs was obtained. The intensity of the discharge glow in optical range correlates with the phase shift map. Previous measurements of plasma density made in Ar under a background gas pressure at a level of a few torrs, based on the Stark effect, are in good agreement with the gained results.
Simulation of aeroacoustics of low Mach number flow with the use of wave equation model
Authors: Guseva E K , Egorov Y
Published: December 2020

Results of simulations of the noise generated by a turbulent flow around a simplified rain gutter of a car windshield are presented. The hybrid approach of ANSYS FLUENT used the scale-resolving SBES model for calculating a turbulent flow under an incompressible flow assumption, and the wave equation model for the propagation of acoustic perturbations. The mean static pressure and the sound intensity obtained in the simulations were compared with experimental data and were found to be well predicted.
Optical properties of alkali halide crystals
Authors: Kaplunov I , Kropotov G , Rogalin V , Shahmin A
Published: December 2020

The results of measuring the transparency bands in a wide wavelength range - from UV to 3000 μm for crystals of sodium chloride (NaCl), potassium chloride (KCl), iodine bromide (KBr) and rubidium iodide (RbI) are presented. It was shown that, along with well-known data on the transparency of these crystals in the UV and IR ranges, they have a transmission zone in the THz range in the region of 1000 μm.
Fragmentation and ablation of the planetesimals in the protoplanetary disks of Jupiter and Saturn
Authors: Kronrod V.A. , Makalkin A.B. , Kronrod E.V.
Published: December 2020

In this study we discuss the capture of bodies into the gaseous disks around young Jupiter and Saturn due to gas drag in the disks. We suppose that solution of the problem will allow estimation of the masses and composition of bodies that fell on the growing icy moons. This would provide explanation of the differences in the mean density and internal structure of giant icy moons of Jupiter and Saturn. The multiparameter problem of braking, fragmentation and ablation of planetesimals (a comet substance) in the gas medium of the circumplanetary disk is solved by a modified approach of the meteor physics. Our research shows that a significant masses of protosatellite material falling on the circumplanetary disks of Jupiter and Saturn are captured in the disks. At the same time the masses captured in the formation region of different moons are very different. The braking and fragmentation of planetesimals can be the main parameter in the mechanism of capture mass of planetesimals by the accretion disks of giant planets. There is a significant difference in the mass of material captured by the aerodynamic braking and ablation in the formation regions of Ganymede, Callisto, and Titan (up to 30-40%). For a material strength of 2* 104 Pa <σ* <2*105 Pa, a significant difference in the amount of matter captured by the disk in the feeding region of the regular ice satellites of Ganymede, Callisto and Titan is possible. The presence of fragmentation is perhaps one of the reasons for the difference in the internal structure of Ganymede, Callisto and Titan.
Development of databases of intelligent expert systems for automatic control of product quality indicators
Authors: Blagoveshchenskiy I G , Blagoveshchenskiy V G , Besfamilnaya E M , Sumerin V A
Published: December 2020

Currently existing methods of product quality assessment are far from perfect, since this assessment is carried out in the laboratories of enterprises. Successful solution of this problem is possible when implementing intelligent expert systems for monitoring and forecasting in the flow of product quality indicators using intelligent technologies in the production process. One of the most important components of the expert system is the database. The article deals with the methodological basis for creating databases for building an intelligent expert system for monitoring and forecasting product quality indicators in the production process. Distinctive features of databases are highlighted. The method of database development is investigated and proposed. The main stages of database development are investigated and analyzed. An integrated conceptual model of the domain database of the integrated expert system has been developed. Developed: a tree of database goals, the composition of the main elements of the database system of the intellectual expert system of product quality control. The main phases and stages of designing the database and expert system have been worked out. VAD data flow diagrams are presented. The description of the domain semantics is developed in the form of a system of functional and multi-valued dependencies between attributes of the conceptual model of the domain database. The database architecture has been developed. The developed specialized database of the integrated expert system for monitoring food quality indicators is a single information environment that provides information for automatic control of product quality indicators.
Mechanics of alpine skiing: carve turn with angulation
Authors: Legotin S D , Obnosov K B , Rivlin A A
Published: December 2020

The article deals with the problem of modeling the movement of an athlete-skier when performing a cut ski turn with angulation. A system of integral equations for dimensionless motion parameters is formulated. its numerical solution, taking into account individual styles of angulation control, allows us to construct the trajectory of the center of mass of the system, estimate its speed, angles that characterize the position of the skier’s body and its skis relative to the slope, and the time of its movement. Examples of calculating the parameters of a carve turn with different style angulations are considered.
Tunneling FET Calibration Issues: Sentaurus vs. Silvaco TCAD
Authors: Nabil Amira , Shaker Ahmed , Abouelatta Mohamed , Ragai Hani , Gontrand Christian
Published: December 2020

In this paper, a comprehensive comparison of TFET simulations using two TCAD simulators, Sentaurus and Silvaco TCAD, is presented. The comparison is fully cover various types of TFETs, either from the structure geometry or the materials point of view, which proved a framework for TFET designs and simulations. For Sentaurus TCAD, a dynamic nonlocal BTBT model is used for all simulations as it is proved a good calibration for experimental data or full quantum data taken from the literature. The BTBT model’s parameters are determined for different material and hetero-junctions structures where they can be used directly for any design or structure calibration. For the Silvaco simulator, a nonlocal BTBT model is utilized for calibration and its parameters are also provided. The study offers quick parameters data to be used directly, utilizing various materials without being involved in calibration difficulties.
Design of a Planar Inverted F-Antenna for Medical Implant Communications Services Band
Authors: Salama Sanaa , Zyoud Duaa , Daghlas Razan , Abuelhaija Ashraf
Published: December 2020

A planar inverted F-implantable antenna is designed using the medical implant communications service (MICS) band (402–405MHz).The proposed antenna is designed using microstrip lines and short-circuited pin connecting between the ground plane and the patch. The total size of the proposed antenna is (24×32×2 mm3). The patch dimensions are (16×24 mm2). The calculated bandwidth at a return loss of -10 dB is 1MHz. The S-parameters, the near and far-fields, and the specific absorption rate (SAR) of the antenna is simulated and characterized. The design is carried out using CST Studio.
Removal of Rhodamine B dye from aqueous solution by heterogeneous UV-Fenton catalytic process
Authors: Lam Hoa-Hung , Tran-Thuy Tuyet-Mai , Dang-Bao Trung
Published: December 2020

In this study, the removal of Rhodamine B at high concentrations (25–100 ppm) from aqueous solution was carried out via the heterogeneous UV-Fenton catalytic process based on Fe3O4 nanoparticles. The removal efficiency of Rhodamine B (C0 = 50 ppm) reached 100% after 4 hours treatment, corresponding to the mineralization efficiency of 70%. In comparison with the conventional Fenton processes, the assistance of UV irradiation boosted the OH• radical generation and prevented the formation of ionic complexes between Fe3+ and Rhodamine B, permitting the catalyst activity improvement. In addition, Fe3O4 nanoparticles could be easily separated by an external magnet and then re-cycled several times with minimal loss of catalyst activity.
Overview of the 17th International Scientific and Technical Conference Rapid Solidification Materials and Coatings
Authors: Lozovan A A , Kostrin D K
Published: December 2020

This overview presents the key features and main goals of the 17th International Scientific and Technical Conference Rapid Solidification Materials and Coatings, which took place on October 20-21, 2020 in Moscow.

List of Organizing Committee, Program Committee, are available in the pdf.
Study into initial stages of plasma electrolytic oxidation of magnesium alloy
Authors: Mukaeva V R , Melnichuk O V , Vasilev R A , Lutfrakhmanov I M , Parfenov E V
Published: December 2020

In the present work, a coating growth during plasma electrolytic oxidation on magnesium alloy was investigated. We observed the initial stages: electrochemical anodizing accompanied by anodic dissolution; oxidation with low power spark discharges; oxidation with microarc discharges. The study discusses the evolution of morphology, porosity, elemental composition in comparison with the PEO electrical characteristics and optical emission of microdischarges. The kinetic model, which is consistent with the observed mechanism of coating growth, is constructed.
Labour Share and Productivity Dynamics
Authors: Choi Sekyu , Ríos-Rull José-Víctor
Published: December 2020

We pose technology shocks where the innovation is biased towards more recently installed plants. On one extreme, the shock is like a neutral technological shock, while on the other end it resembles investment-specific technological shocks. We embed these shocks in a model with putty–clay technology and estimate it requiring that the model replicates the volatility properties of the Solow residual and the overshooting property of the labour share of output. Our estimates show that putty–clay nature of technology, a time bias towards new plants and competitive wage setting replicate well the overshooting property.
The reporting quality of split-mouth trials in orthodontics according to CONSORT guidelines: 2015–19
Authors: Qin Danchen , Hua Fang , Liang Shengjie , Worthington Helen , He Hong
Published: December 2020

Objectives

To assess the reporting quality of split-mouth trials (SMTs) in orthodontic journals, and to identify factors associated with better reporting.

Materials and methods

Seven leading orthodontic journals were hand searched for SMTs published during 2015–19. The CONSORT 2010 guideline and CONSORT for within-person trial (WPT) extension were used to assess the trial reporting quality (TRQ) and WPT-specific reporting quality (WRQ) of included SMTs, respectively. A binary score (0 or 1) was given to each item of the guidelines, and total scores were calculated for TRQ (score range, 0–32) and WRQ (score range, 0–15). Univariable and multivariable linear regression analyses were performed to identify factors associated with TRQ and WRQ.

Results

A total of 42 SMTs were included. The mean overall scores for TRQ and WRQ were 16.8 [standard deviation (SD) 7.1] and 5.6 (SD 2.3), respectively. Only 11 SMTs (26.2%) presented the rationale for using a split-mouth design. Key methodological items including random sequence generation (22/42, 52.4%), allocation concealment (9/42, 21.4%), and blinding (20/42, 47.6%) were poorly reported. Only six SMTs (14.3%) used a paired method for sample size calculation, and half (21/42, 50.0%) considered the dependent nature of data in statistical analysis. In multivariable analyses, higher TRQ and WRQ were both significantly associated with journal, reported use of CONSORT and funding status.

Conclusions

The reporting quality of SMTs in orthodontics has much room for improvement. Joint efforts from relevant stakeholders are needed to improve the reporting quality of SMTs and reduce relevant avoidable research waste.
Physical, genetic and functional interactions between the eisosome protein Pil1 and the MBOAT O-acyltransferase Gup1
Authors: Tulha Joana , Amorim-Rodrigues Mariana , Esquembre Lidia Alejo , Rauch Sebastien , Tamás Markus J , Lucas Cândida
Published: December 2020

The Saccharomyces cerevisiae MBOAT O-acyltransferase Gup1 is involved in many processes, including cell wall and membrane composition and integrity, and acetic acid-induced cell death. Gup1 was previously shown to interact physically with the mitochondrial membrane VDAC (Voltage-Dependent Anion Channel) protein Por1 and the ammonium transceptor Mep2. By co-immunoprecipitation, the eisosome core component Pil1 was identified as a novel physical interaction partner of Gup1. The expression of PIL1 and Pil1 protein levels were found to be unaffected by GUP1 deletion. In ∆gup1 cells, Pil1 was distributed in dots (likely representing eisosomes) in the membrane, identically to wt cells. However, ∆gup1 cells presented 50% less Pil1-GFP dots/eisosomes, suggesting that Gup1 is important for eisosome formation. The two proteins also interact genetically in the maintenance of cell wall integrity, and during arsenite and acetic acid exposure. We show that Δgup1 Δpil1 cells take up more arsenite than wt and are extremely sensitive to arsenite and to acetic acid treatments. The latter causes a severe apoptotic wt-like cell death phenotype, epistatically reverting the ∆gup1 necrotic type of death. Gup1 and Pil1 are thus physically, genetically and functionally connected.
Prevalence of Child Marriage Among Yemeni and Somali Refugee and Host Communities in Djibouti, 2019
Authors: Ben Hamida Amen , Hunersen Kara , Houssein Barkat Hemeda , Doualeh Aden Yacin , Hersi Doualeh Robleh , Elmi Nika , Metzler Janna , Robinson W Courtland
Published: December 2020

Despite increased vulnerability of displaced communities, the evidence of child marriage in humanitarian setting remains scarce. We conducted this study to estimate the prevalence of child marriage among Somali and Yemeni refugees and their host communities in Djibouti; and assess its independent associations with different exposure variables. Using a stratified random sampling design, we recruited eligible refugee and hosts-near-refugee households within four cites in Djibouti during February–March 2019. We assessed the prevalence of females aged 20–24 married <15 and <18, the prevalence of marriage within females aged 10–19 and 15–19, and multivariate associations between exposure variables and child marriage. Overall, 1,276 households and 6,784 household members were recruited. Among female refugees aged 20–24 (N=107), the prevalence of first married <18 was 10.5 percent and 4 percent for Yemeni and Somali refugees; and among female refugees aged 10–19 (N=1,239), the prevalence of marriage was 7.8 percent and 6.6 percent for Yemeni and Somali refugees, respectively. Child marriage was independently associated with age of the girl (AOR=1.60, 95% CI=1.38–1.85); education level of the head-of-household (AOR=2.65, 95% CI=1.45–4.84); and education of the girl (AOR=0.56, 95% CI =0.30–1.05). This study provides the estimates of child marriage prevalence within Somali and Yemeni refugee communities in Djibouti, adds to the evidence on the protective role of girls education against child marriage, and informs child health, education, and protection programmes targeting these communities in the future.
Sustainability in Refugee Camps: A Comparison of the Two Largest Refugee Camps in the World
Authors: Wardeh Mai , Marques Rui Cunha
Published: December 2020

Although the refugee phenomenon is not new and refugee camps are rarely temporary, in most cases, the procedures implemented within refugee camps have failed to apply principles of sustainability to ensure refugees’ dignity and improve their quality of life, thereby helping them become independent and self-reliant. This improvement, in turn, may help them return to their homes in the future or may, at least, reduce the high cost and negative coping strategies associated with refugee camps and instead increase refugees’ social integration within the host community. This paper discusses the procedures applied in both the Zaatari refugee camp in Jordan and the Dadaab Refugee Complex in Kenya and provides evidence regarding the extent to which they meet the United Nations 2030 Agenda for Sustainable Development without leaving refugees behind. Furthermore, this paper shows how sustainable development goals (SDGs) are interconnected in a refugee camp setting. This study concludes that refugee camps not only failed to align with 2030 agenda but failed to ensure refugees’ basic rights where a more inclusive and sustainable approach is required to improve the refugees’ quality of life and to help them live in dignity and reach self-reliance that can benefit both refugees and their host communities.
Chromatin structure restricts origin utilization when quiescent cells re-enter the cell cycle
Authors: Lee Po-Hsuen , Osley Mary Ann
Published: December 2020

Quiescent cells reside in G0 phase, which is characterized by the absence of cell growth and proliferation. These cells remain viable and re-enter the cell cycle when prompted by appropriate signals. Using a budding yeast model of cellular quiescence, we investigated the program that initiated DNA replication when these G0 cells resumed growth. Quiescent cells contained very low levels of replication initiation factors, and their entry into S phase was delayed until these factors were re-synthesized. A longer S phase in these cells correlated with the activation of fewer origins of replication compared to G1 cells. The chromatin structure around inactive origins in G0 cells showed increased H3 occupancy and decreased nucleosome positioning compared to the same origins in G1 cells, inhibiting the origin binding of the Mcm4 subunit of the MCM licensing factor. Thus, quiescent yeast cells are under-licensed during their re-entry into S phase.
Bicameral Lawmaking: Analysing the Choices of Revising Chambers
Authors: Alemán Eduardo , Mimica Nicolás , Navia Patricio
Published: December 2020

This article examines the choices made by revising chambers in bicameral congresses. It analyses how bill characteristics, chamber congruence, impatience and institutional context influence the decisions made by revising chambers regarding executive bills sent by the chamber of origin. The analysis focuses on the case of Chile, a presidential country in which the executive has substantial proposal power. The findings show that the probability of a bill passing with amendments is higher when it receives a presidential urgency and when the revising chamber is the Senate. Executive bills coming out of the Finance Committee are more likely than others to pass unamended. However, those bills are more likely to die in committee when the revising chamber is the Senate (i.e. the chamber whose membership has a longer time horizon).
Classification of Psychoses Based on Immunological Features: A Machine Learning Study in a Large Cohort of First-Episode and Chronic Patients
Authors: Enrico Paolo , Delvecchio Giuseppe , Turtulici Nunzio , Pigoni Alessandro , Villa Filippo Maria , Perlini Cinzia , Rossetti Maria Gloria , Bellani Marcella , Lasalvia Antonio , Bonetto Chiara , Scocco Paolo , D’Agostino Armando , Torresani Stefano , Imbesi Massimiliano , Bellini Francesca , Veronese Angela , Bocchio-Chiavetto Luisella , Gennarelli Massimo , Balestrieri Matteo , Colombo Gualtiero I , Finardi Annamaria , Ruggeri Mirella , Furlan Roberto , Brambilla Paolo
Published: December 2020

For several years, the role of immune system in the pathophysiology of psychosis has been well-recognized, showing differences from the onset to chronic phases. Our study aims to implement a biomarker-based classification model suitable for the clinical management of psychotic patients. A machine learning algorithm was used to classify a cohort of 362 subjects, including 160 first-episode psychosis patients (FEP), 70 patients affected by chronic psychiatric disorders (schizophrenia, bipolar disorder, and major depressive disorder) with psychosis (CRO) and 132 health controls (HC), based on mRNA transcript levels of 56 immune genes. Models distinguished between FEP, CRO, and HC and between the subgroup of drug-free FEP and HC with a mean accuracy of 80.8% and 90.4%, respectively. Interestingly, by using the feature importance method, we identified some immune gene transcripts that contribute most to the classification accuracy, possibly giving new insights on the immunopathogenesis of psychosis. Therefore, our results suggest that our classification model has a high translational potential, which may pave the way for a personalized management of psychosis.
In vitro susceptibility testing for black grain eumycetoma causative agents
Authors: van de Sande Wendy W J
Published: December 2020

Eumycetoma is a neglected tropical implantation mycosis characterized by large subcutaneous swellings. Inside the infected tissue, the causative agents are found in grains. The most common causative agents form black grains and are sterile upon isolation. In vitro susceptibility assays were developed for eumycetoma causative agents. They were based on the Clinical and Laboratory Standards Institute M38A protocol and modified to enable the use of hyphae as a starting inoculum. To ease endpoint reading, viability dyes such as resazurin or XTT have been used. So far the in vitro susceptibility assays developed have mainly been used to establish if causative agents are inhibited in growth by various antifungal agents, but not for clinical decision making. For drug discovery, the assay proved useful in determining which compounds were able to prevent hyphal growth. However, a clear correlation between in vitro inhibition in terms of the half maximal inhibitory concentration or 50% minimum inhibitory concentration (MIC50) and therapeutic efficacy assayed in a novel model system in terms of Galleria mellonella larval survival was not found. For clinical decision making, a range of MICs were found for each antifungal agent. However, no clinical breakpoints have been established for any of the causative agents. For itraconazole, the MIC50 of most causative agents was below the attainable serum levels, which might indicate that they are susceptible. However, before in vitro susceptibility can be used in clinical decision making for mycetoma, a correlation between MIC and clinical outcome needs to be made.
Increased epicardial adipose tissue thickness associated with increased metabolic risk and the presence of heart failure in patients with Chronic Chagas disease
Authors: Rodeles Luz María , Castro Maximiliano , Zamora María Ayelen Gaitán , Savarino Roberto , Peverengo Luz María , Prochetto Estefanía Soledad , Marcipar Iván , Arias Pablo , Vicco Miguel Hernán
Published: December 2020

Background

It has been described that Trypanosoma cruzi is capable of promoting metabolic disturbances currently considered as cardiovascular risk factors. Moreover, it has been observed that the protozoa can remain in adipose tissue and alter its immune endocrine functions. The aim of this study was to characterize the thickness of epicardial adipose tissue (EAT) in patients with chronic Chagas disease (CCD) concerning their cardiovascular metabolic risk profile compared with those without CCD.

Methods

A cross-sectional study was performed including T. cruzi seropositive individuals categorized according to a standard CCD classification and a matched seronegative control group. Complete clinical examination, metabolic laboratory tests and transthoracic echocardiography to assess cardiac function and to quantify EAT were performed.

Results

Fifty-five individuals aged 46.7±11.9 y, 34 with CCD and 21 in the control group, were included. The CCD group presented higher EAT thickness in relation to controls (4.54±1.28 vs 3.22±0.99 mm; p=0.001), which was significantly associated with the presence of insulin resistance (OR=3, 95% CI 1.58 to 5.73; p<0.001). This group presented lower levels of plasmatic adiponectin than controls, especially in those patients with EAT ≥4.5 mm (p=0.005) who also presented with heart failure more frequently (p=0.01).

Conclusion

In patients with CCD, a higher EAT thickness is observed and is associated with an increased metabolic risk profile indicated mainly by insulin resistance.