bluuebunny/crossref_metadata_2025_split huggingface dataset:
Topological optics with 3D-tangle laser solitons
Authors: Fedorov S V , Rosanov N N , Veretenov N A 
Published: April 2020

Abstract
We analyse, theoretically and numerically, stable localized 3D- structures with radiation wavefront singularities in lasers or laser media with fast saturable absorption; radiation has a fixed polarization state. These laser solitons’ internal structure is characterized by their skeletons, which consist of vortex lines where the field vanish and radiation phase changes by 2πm with integer m – topological charge – as a result of a round-trip around the line. The vortex lines are oriented according the direction of radiation phase increase; high-order vortex lines (m>1) are unstable and split into m lines with m=1. Complexes of fundamental (without vortices when isolated) laser solitons have unclosed vortex lines. Presented are topological laser solitons with vortex lines, which are unclosed and closed, unknotted and knotted, unlinked and linked. Various types of the solitons are stable in different, but overlapping domains of the scheme parameters; a slow variation of such parameters leads to hysteretic variations of solitons’ characteristics. Such hysteresis is reversible if soliton’s topology does not change during the parameters’ variation, and irreversible in the opposite case. The increased stability of dissipative solitons and the preservation of the topological characteristics of structures under perturbations make topological laser solitons promising for information applications.
Bound states in the continuum supported by two-layered wires structure
Authors: Sadrieva Zarina , Song Mingzhao , Kapitanova Polina , Bogdanov Andrey 
Published: April 2020

Abstract
In this work, we study theoretically and experimentally appearance of bound states in the continuum in a resonator composed of two layers of polycarbonate wires. We show how distance between the wires affects the BICs frequency and quality factor of the eigenmodes.
Miniature Otto configuration implemented by two-photon laser lithography
Authors: Safronov Kirill R. , Akhremenkov Daniil V. , Bessonov Vladimir O. , Fedyanin Andrey A. 
Published: April 2020

Abstract
In this work we develop the concept of miniature Otto configuration. The distinctive feature of the proposed prism configuration is an operation for normal angle of incidence. Polymer microprisms with size of several tens of microns were fabricated by two-photon laser lithography on a surface of one-dimensional photonic crystal. The performance of the prisms was studied in the case of the Bloch surface waves excitation. Design of the prism and its optimal geometrical parameters were obtained from results of calculations. Bloch surface waves excitation with the microprisms was observed by the leakage radiation microscopy. The dependence of coupling efficiency on the angle of incidence was studied. Proposed prism configuration is easily compatible with fibers and is very appealing alternative to diffraction grating coupling for future applications.
The development of double-sided nonreflecting absorber of the terahertz waves on the basis of metamaterials
Authors: Semchenko Igor , Khakhomov Sergei , Samofalov Andrey , Faniayeu Ihar 
Published: April 2020

Abstract
The paper aimed to study the interaction of the THz range electromagnetic waves with metamaterials, consisting of rectangular omega elements, as well as to develop a one-sided and double-sided “ideal” THz wave absorber based on such structures.
Photonic nanojets generated by alumina microstructures with different surface morphology
Authors: Sergeev A A , Sergeeva K A , Leonov A A , Voznesenskiy S S 
Published: April 2020

Abstract
The interaction of optical radiation with dielectric microparticles, leading to the emergence of field spatial localization called the “photonic nanojet” was numerically and experimentally studied within the wide range of environment refractive indexes. It is established that at a certain ratio of the microparticle and the environment refractive indexes, as well as the curvature of the particle profile, the photonic nanojet effect can be used to locally excite the sensitive layer of fluorescent sensors of chemical compounds in liquid and gaseous media.
Metasurfaces with magnetoelectric dipolar coupling near PEC substrate
Authors: Shamkhi H. K. , Shalin A. S. 
Published: April 2020

Abstract
Using metasurfaces, light can be manipulated beyond the limitations of classical optics. For instance, metasurfaces are used to widen the antenna aperture, to tailor light polarization, to be transparent, etc. Here, we study the effective fields in a magnetoelectric dipolar lattice positioned near PEC substrate. We show analytically that in the case of a subwavelength lattice spacing, the coupling between the electric and magnetic dipoles is induced mainly by the substrate reflected fields of dipoles at the coordinate of the perspective centre.
Calculation of the 1D grating scattering matrix frequency derivatives
Authors: Shcherbakov Alexey A. , Pogorelskaya Lydia Yu. , Bogdanov Andrey A. 
Published: April 2020

Abstract
In this contribution we develop methods for calculation of complex poles of scattering matrices which are based on analytically found frequency derivatives of these matrices instead of commonly used finite difference derivation. The analysis is made within the framework of the Fourier Modal Method and the analytical scattering matrix method proposed previously. Usage of analytical formulas may improve the accuracy of numerical algorithms based on the matrix Newton and Householder methods.
Synthesis, characterization, and diffraction study of three-dimensional icosahedral quasicrystals
Authors: Sinelnik A D , Zhukov M V , Samusev K B , Rybin M V , Limonov M F 
Published: April 2020

Abstract
Three-dimensional icosahedral quasicrystals have been fabricated by two-photon polymerization technique. Such quasicrystals have icosahedral symmetry in three dimensions which is forbidden for true periodic crystals. The correspondence of the resulting quasicrystals to the designed structures was confirmed by scanning electron microscopy. We investigated the optical interference properties of icosahedral quasicrystals using a laser diffraction technique.
Tuning of far-field and near-field via fs-laser in various hybrid oligomers
Authors: Sun Yali , Ageev Eduard , Zuev Dmitry 
Published: April 2020

Abstract
Oligomers have attracted intense attention due to the mode interference. We have simulated the tuning effect of far- and near-field properties of four different compositions of hybrid metal/dielectric oligomers before and after the gold components modified by femtosecond laser. The achieved results could be applied in optical sensing, field-enhanced nonlinear process as well as biophotonic applications.
Evolution of multipole moments in silicon nanocylinder while varying the refractive index of surrounding medium
Authors: Terekhov P. D. , Shamkhi H. K. , Gurvitz E. A. , Baryshnikova K. V. , Evlyukhin A. B. , Shalin A. S. , Karabchevsky A. 
Published: April 2020

Abstract
Here we use multipole decomposition approach to study optical properties of a silicon nanocylinder in different lossless media. We show that resonant peaks of multipole moments experience red shift, smoothing and broadening. Worth noting that electric multipoles experience bigger red shift than their magnetic counterparts. Our results can be applied to design optical devices within a single framework.
Reactive molecular dynamics simulations and machine learning
Authors: Krishnamoorthy Aravind , Rajak Pankaj , Hong Sungwook , Nomura Ken-ichi , Tiwari Subodh , Kalia Rajiv K , Nakano Aiichiro , Vashishta Priya 
Published: April 2020

Abstract
Machine learning (ML) is revolutionizing scientific and engineering disciplines owing to its ability to capture hidden patterns in large amounts of data. The recent success of ML can be attributed to increasing amount of data, simulation resources, and improving understanding of statistical inference. For these reasons computational materials science is undergoing a paradigm shift. The main reason is that trial-and-error approach to materials design is inefficient: laboratory trials require a lot of time, and the results of previous trials are not utilized in a systematic fashion. A data-driven approach, which draws upon all relevant data from experiments, and reactive and quantum molecular dynamics simulations, can address these issues. The MAGICS (Materials Genome Innovation for Computational Software) Center develops to aid the synthesis of stacked layered materials by chemical vapor deposition, exfoliation, and intercalation. The identification of different phases is a classification problem and can be solved using ML techniques. We have used feed-forward neural network with three hidden layers to identify the different phases present during computational synthesis of MoSe2. Our goal is to carry out exascale MD simulations using forces for multimillion-atom quantum dynamics simulations from neural networks and deep learning using small QMD simulations.
Influence of carbon contamination on transparency of reactive SPSed Nd3+:YAG ceramics
Authors: Kosyanov D Yu , Tikhonov S A , Vornovskikh A A , Yavetskiy R P , Dobrotvorskaya M V , Doroshenko A G , Shichalin O O , Papynov E K , Ustinov A Yu 
Published: April 2020

Abstract
Influence of carbon contamination from the paper and dies on structural-phase state and transparency were studied for SiO2-doped Nd3+:Y3Al5O12 ceramics obtained via reactive spark plasma sintering (SPS). It is shown that the transparency of post-annealed ceramics is sensitive to the SPS temperature. Since the swelling effect is related to the amount of the carbon phases as well as their composition and depth of location, the degradation becomes remarkable with the temperature increasing above critical for SiO2-doped Nd3+:Y3Al5O12 system. Ceramics fabricated at 1500°C contains SiC and SiOC-based impurity phases, which are relatively stable for post-annealing. Removal of generated defects is possible for ceramics fabricated at relatively low temperatures (∼1350°C).
Toroidal dipolar excitations in all-dielectric nanostructures
Authors: Xu Lei , Saadabad Reza Masoudian , Cai Marcus , Miroshnichenko Andrey E. 
Published: April 2020

Abstract
We have numerically investigated toroidal dipolar excitation at optical frequencies in Si nanostructures. Our results show that, through either special structured pump illumination, or by adding an additional layer associated with geometric tuning, we are able to excite strong toroidal dipolar responses with suppressed electric dipolar excitations. These findings may further pave the way to exploit future applications of toroidal resonances including optical nonlinear enhancement, induced transparency for narrow-band filter, etc.
Near-field characterization of ultra-thin metal films
Authors: Yakubovsky D I , Arsenin A V , Kirtaev R V , Ermolaev G A , Stebunov Y S , Volkov V S 
Published: April 2020

Abstract
Ultra-thin metal films will form the basis of next-generation optoelectronics. However, characterization of their performance requires consideration of nanocrystalline structure and analysis of local optical and electrical properties. In present study, we use scanning near-field optical microscopy (SNOM) for nanoscale probing of optical conductivity of ultrathin metal films. We obtained surface maps of scattered near-field signal for gold films grown on monolayer graphene and MoS2 films as well as on a pure Si/SiO2 substrate. These results clearly demonstrate the difference in generated optical responses and can be used in the development of various devices utilizing ultrathin metal films.
Diffusion tensor based forearm nerve tractography in 1.5 T MRI
Authors: Zubkov M. , Efimtcev A. , Trufanov G. , Gulko A. , Popov S. , Orlov I. , Slobozhanyuk A. , Melchakova I. 
Published: April 2020

Abstract
Diffusion tensor imaging (DTI) is a magnetic resonance imaging (MRI) method for efficient nerve pathways visualization. DTI, particularly of peripheral nerves, is commonly performed in 3 T scanners. An often more accessible 1.5 T scanners are less likely to be chosen for DTI examinations due to generally lower image quality. Novel radiofrequency (RF) coils can help improve the signal to noise ratio in MRI and thus improve image quality. This study preliminary results of the feasibility and outcomes assessment of DTI-based tractography of the forearm nerves employing a novel coil design in 1.5 T scanners. The proposed scanning protocol includes the use of a metamaterial-inspired RF coil, a common DTI pulse sequence and a 3D T1-weighted morphological reference pulse sequence. The protocol is tested on three healthy volunteers. Two tract bundles corresponding to median and ulnar nerves of the forearm are reliably reconstructed in all subjects. The results show that with an appropriate choice of RF coil and pulse sequence parameters forearm DTI studies can be performed in 1.5 T scanners with sufficient quality making such examination more accessible for clinical use.
Extraction of Calophyllum oil as biodiesel raw material using a binary solvent
Authors: Sailah I , Bernia O T O , Kartika I A 
Published: April 2020

Abstract
The utilization of renewable raw material, low-cost feedstock, and efficient energy are the main parameters in sustainable biodiesel production. Calophyllum seeds are potential as a vegetable oil source for biodiesel production due to their high oil content and productivity. Calophyllum oil extraction is usually conducted by the mechanical press, but the yield and quality of oil produced by this method are very low. Calophyllum oil extraction using a binary solvent (a mixture of n-hexane and alcohol) was thus investigated to meet the aspects of sustainability and to solve the problem of mechanical extraction. The influence of extraction condition was examined to determine optimal oil yield and quality. The mixture of n-hexane and alcohol effectively extracts oil from Calophyllum seeds and simultaneously purified it from resin. The n-Hexane-to-alcohol ratio had a significant effect on oil recovery and its quality. The augmentation of the n-hexane-to-alcohol ratio from 1:1 to 2.5:1 increased oil yield. Acid value and density of oil improved as the n-hexane-to-alcohol ratio declined from 2.5:1 to 1:1. The n-Hexane-to-alcohol ratio of 2.5:1 has provided the best yield (88.0%) of oil extract at 40°C for 5 h. The oil present its best quality at 0.893 g/cm3 of density, 41.0 mPa.s of viscosity, 8.8 mg KOH/g of acid value, 88.3 g/100 g of iodine value, < 1% of moisture content and < 0.04% of ash content.
Effect of kluwak biomass fermentation and storage time on meat quality
Authors: Patriani P , Hafid H , Mirwandhono E , Wahyuni T H 
Published: April 2020

Abstract
Lamb meat is one of the animal protein sources that contains high protein so it is easily damaged. One easy and cheap method to extend the storage time is by using spices, known as kluwak seeds (Pangium edule). This study aimed to determine the effect of fermented kluwak biomass in the storage time of water holding capacity, cooking loss, drip loss, and texture of lamb meat. This study used a factorial complete design with 3 replications. The results showed that the immersion level of fermented kluwak and storage time had a significant effect on water holding capacity, meat texture and drip loss (P<0.05) but had no effect on cooking meat loss (P>0.05). It is concluded that the use of fermented kluwak from 3% to 9% of meat weight can maintain the physical quality of lamb meat for 36 hours.
Improving the accuracy of near-infrared (NIR) spectroscopy method to predict the oil content of oil palm fresh fruits
Authors: Novianty I , Seminar K B , Irzaman  , Budiastra I W 
Published: April 2020

Abstract
Oil content is an important factor to determine the price of the oil palm fruit. In this study, the NIR Spectroscopy method was conducted to determine the oil content of oil palm fresh fruits. Several studies that related to the NIR spectroscopy method for predicting the oil content of oil palm fruits showed that the accuracy was still optimal yet. This study is the initial stage to develop the optical portable instrument that can predict the oil content of oil palm fresh fruits. Five hundred samples which are divided into ten groups based on maturity levels were prepared for reflectance and oil content chemical measurement. The reflectance of the sample was measured by the FT-NIR spectrometer in the wavelength of 1000-1500 nm. The obtained spectrum of oil palm fresh fruits was transformed to absorbance (Log 1/R) and several spectra data processing was conducted to increase the accuracy of prediction. The calibration and validation of processed NIR spectra and the oil content were conducted using Partial Least Square (PLS) and MLR methods. Generally, PLS and MLR methods can be used to improve the accuracy of the NIR spectroscopy method. Then, the result showed that the MLR method is less accurate than the PLS method to predict the oil content of oil palm fresh fruits. In this study, the best result could be determined by the PLS model using 5 factors and spectra data processing of the first derivative of spectra absorbance (R=0.879; CV=19.8%; RPD= 2.46). A lower accuracy was obtained by MLR model (R=0.677; CV=28.33%; RPD =1.72).
Investigation of eco-friendly plywood bonded with citric acid – starch based adhesive
Authors: Kusumah S S , Jayadi  , Wibowo D T , Pramasari D A , Widyaningrum B A , Darmawan T , Ismadi  , Dwianto W , Umemura K 
Published: April 2020

Abstract
Concerning the environmental issues, the eco-friendly panel product has been developed by using natural based adhesive to ensure safe product application for human health. In this study, Paraserienthes falcataria veneer and citric acid – starch were used in the manufacturing of plywood. The 30 wt% concentration of citric acid – starch-based adhesive was prepared and it was spread to each veneer with 150 g/m2 of glue spread. The plywood was constructed by 3 layers of veneers. The dimension of each veneer was 30 × 30 × 0.2 (cm). The effect of composition ratio between citric acid (CA) and starch (St) as natural sources of adhesive on delamination and shear strength of the plywood was investigated. The plywood was produced under pressing conditions of 180°C for 10 min with 5 MPa of pressure. The variation of compositions ratio (CA:St) were 90:10, 80:20, 70:30, 60:40, 50:50. The research results showed that the plywood with 50 wt% additional of starch had the lowest delamination and highest shear strength. The shear strength of plywood satisfied Standard National Indonesia (SNI) of plywood for general use. Infrared (IR) spectral analysis demonstrated the presence of ester linkage, indicating that the carboxyl groups of citric acid reacted with the hydroxyl groups of the wood veneer. Therefore, 50:50 of composition ration between CA and St was effective composition ratio in the manufacturing of eco-friendly plywood.
Degradation quality of reused palm cooking oil during storage: case study in fried shallot industry
Authors: Warsiki E , Iskandar A , Hidayati M 
Published: April 2020

Abstract
Frying process in a fried shallot industry usually is carried out by deep fat frying. This method involves the use of much oil and repeatedly uses and storages. This practice will decrease the quality of oil and even the fried product. The objectives of this research were to measure the quality degradation rate of use cooking oil repeatedly during storage and to calculate the efficiency of zeolite to adsorb the impurities of the reused cooking oil. The Oil quality was based on the National Standard of Indonesia (SNI 7709:2012). The quality parameters observed in this research were water and evaporated material content, free fatty acid value, and peroxide number. Based on the results of this research, it was found that the oil still meets the quality standard until the 5th frying without storage. In this stage, the oil exposed the rate of degradation in water and evaporated material content, free fatty acid value, and peroxide number as 0.0046; 0.0878, and 0.303 respectively. The content of water, moisture and oxygen were the main cause of quality changes in cooking oil. The effort has been done to improve the quality of reused cooking oil by zeolite adsorption. Efficiency values obtained from this process by moisture and evaporated material content, free fatty acid value, and peroxide number was 8.20%; 52.38%; and 30.95% respectively.
An LCA and energy analysis of a biomass integrated-pyrolysis gasification/SOFC system with H2S removal
Authors: Sugihara Hiromu , Kameyama Mitsuo , Dowaki Kiyoshi 
Published: April 2020

Abstract
Fuel cell power systems are considered attractive for their potential for mitigating climate change. Here, the fuel is assumed to be synthesized through an indirect pyrolysis gasification process, and the integrated gasification SOFC system is considered in this study. In the performance of SOFC, the impurities (e.g., H2S) in a fuel affect the system, i.e., the voltage of a cell drops. Regarding the removal of impurities, conditions besides the species of adsorbent, like temperature and pressure, must be considered. Therefore, we compared the following two adsorbents in terms of the operational and environmental performances: non-recyclable CeO2 (high temperature) and recyclable Hydroxyl Aluminum Silicate Clay (HAS-Clay) (low temperature). Moreover, we estimated energy and exergy efficiencies, and life cycle assessment impacts on both adsorbents. The total exergy efficiencies were 35.6 % for CeO2 and 33.0 % for HAS-Clay. This implies that 19 recycling cycles with the use of HAS-Clay are necessary to obtain the advantage for the CeO2 case in terms of abiotic depletion potential which is one of the impact categories.
Investigation of producer gas biomass gasification on reciprocated internal combustion engine
Authors: Naryanto R F , Enomoto H , Anh V C , Fukadu K , Iwai S , Noda R 
Published: April 2020

Abstract
Biomass is sustainable and a source for renewable energy to overcome the limitation of fossil fuel. The research used woody pellet feedstock with 0.79 g/cm3 of bulk density and 6 mm diameter in the syngas production. Therefore, downdraft gasifier reactor with a stainless steel pipe 500 mm length and 120 mm inner diameter produced syngas as producer gas. Reciprocated Internal Combustion Engine (R-ICE) was used to drive the syngas production from biomass gasification process with 1800 rpm ± 20 rpm in constant engine speed. The Indication of Mean Effective Pressure (IMEP) and Excess Air Rate (EAR) were applied as the parameters for analyzing the system. Kawasaki FD750 with single cylinder was implemented to test the effect of syngas instability. Oxidizer and fuel for the engine were mixed in the venture which typed Heinzmann, GM 50 to make homogenous fuel. The laminar flow meter type of Sokken, LFE-25B was adapted to measure the intake air flow rate, and the digital ignition system of Altronic, CD200D was used to control the ignition timing. In conclusion, the synthetic gas (syngas) as the main fuel will not be enough to replicate drive on R-ICE.