bluuebunny/crossref_metadata_2025 huggingface dataset:
A practical realization of an artificial magnetic shield for preclinical birdcage RF coils
Authors: Lezhennikova K. , Hurshkainen A. , Simovski C. , Abdeddaim R. , Enoch S. , Raaijmakers A. , Melchakova I. , Glybovski S.
Published: April 2020

In the most of magnetic resonance imaging (MRI) systems, a conventional radiofrequency (RF) electric shield is typically placed around an RF volume coil to avoid the interaction with the other components of the system. Disadvantageously metal shields reduce the transmit efficiency of the RF coil as well as its receive sensitivity due to out-ofphase reflection of electromagnetic waves. In contrast, an ideal magnetic shield having high surface impedance provides in-phase reflection, which can be promising for improvement of RF coil’s performance. In this work, we propose an artificial magnetic shield based on a cylindrical miniaturized corrugated structure to improve characteristics of a small-animal birdcage coil at 7T. The coil was simulated in the presence of the metal and ideal magnetic shield as well as the proposed structure. The results demonstrate enhancement of the coil’s performance in the presence of the proposed shield, which is comparable with an ideal one.
Controlling liquid crystal alignment by micro-patterned substrates
Authors: Mamonova A V , Gorkunov M V , Kasyanova I V , Artemov V V , Palto S P
Published: April 2020

We propose a method of controlling the liquid crystal alignment at rubbed polyimide substrates by patterning them periodically with the focused ion beam. The pattern duty factor sets the alignment conditions which determine the light phase retardation that can be precisely varied in a range from zero to that of the background. The method opens up opportunities for creating tunable optical devices.
Parametric study of metamaterial-inspired resonator for wireless power transfer
Authors: Markvart A. , Song M. , Belov P. , Simovski C. , Kapitanova P.
Published: April 2020

A metamaterial-inspired resonator for free-positioning wireless charging of several devices is proposed and numerically studied. The resonator is based on orthogonal metallic wires arrays deposited on a high permittivity low loss dielectric substrate. Given a fixed area of 50 × 50 cm, its resonant frequency can be tuned in a wide frequency band from 5 MHz to 45 MHz. A parametric study is performed to reveal the influence of resonant frequency, dielectric permittivity and number of wires on Q-factor.
Electromagnetics of two-dimensional materials with time-varying carrier density
Authors: Maslov Alexey V. , Bakunov Michael I.
Published: April 2020

The variation of carrier density in two-dimensional materials, such as graphene, creates opportunities for rapid control of guided wave propagation which can find numerous applications in optoelectronics. A general theoretical approach to calculate the transformation of the surface wave guided by a two-dimensional material is presented. The frequencies of the excited modes and their energies are analyzed. Our results refute the claims of plasmon amplification under rapid density changes that appeared in recent theoretical studies. The difference in the results stems from the different treatment of the microscopic current during the carrier density changes.
Flexible plasmonic and strain sensors: fabrication, design and perspectives
Authors: Gontier Arthur , Marae-Djouda Joseph , Hmima Abdelhamid , Proust Julien , Bercu Nicolas Bogdan , Joncour Léa Le , Stagon Stephen , Konoplev G. , Tarasov S. A. , Adam Pierre-Michel , Gardan Julien , Panicaud Benoît , Molinari Michael , Maurer Thomas
Published: April 2020

In this paper, we aim at debating the perspectives for plasmonic strain sensors which have attracted interest for the past five years. In particular, we strive to discuss the choice of strategy to increase the sensitivity, either by developing random or ordered assemblies of metallic nanotsructures.
Ceramic resonator as an alternative to the highly dense receive arrays in MRI
Authors: Mikhailovskaya A , Shchelokova A , Slobozhanyuk A , Andreychenko A
Published: April 2020

Radiofrequency coils are an essential magnetic resonance imaging hardware component. They directly impact the spatial and temporal resolution, sensitivity, and uniformity in the MRI. Advances in radiofrequency equipment have led to the creation of many designs that are optimised for specific clinical applications. Here, the potential of ceramic resonators is investigated to replace radiofrequency surface coils. Three structures were compared: a ceramic resonator, a loop size comparable to the size of a ceramic resonator, and a loop whose size was smaller than the size of a ceramic resonator.
Second harmonic generation enhancement of 2D metal-organic framework using silicon nanoparticles
Authors: Kulachenkov N K , Milichko V A
Published: April 2020

Here we report on the 10 times enhancement of nonlinear optical signal coming from layered Cu-based metal-organic frameworks (MOFs) by means of placing of optically resonant silicon nanoparticles on the top of MOFs. These nanoparticles placed on the top of single MOFs allow the optical field localization and enhancement inside the framework due to the generation of Mie-type modes.
Realizing Caustics in Acoustic Fields
Authors: Moeini S , Memoli G , Subramanian S
Published: April 2020

We present a method to realise a wide class of caustics in acoustic fields created by a set of phase holograms realized with metasurfaces. Given the desired caustic shape, we discuss how to identify the phase distribution along the metasurfaces and describe the calculations needed for determining the pressure field in the vicinity of the caustic. The results of this work can be used in realising acoustic traps controllable with acoustic metamaterials.
One step synthesis Pd/NiO@rGO/CNTs nanocomposite for energy storage as supercapacitor application
Authors: Kumar Rajesh , Abdel-Galeil Mohamed M. , Matsuda Atsunori , Moshkalev Stanislav A.
Published: April 2020

In this study, graphite oxide was reduced into reduced graphene oxide nanosheets (rGO NSs) by microwave with metal acetate of nickel and palladium to form the rGO-carbon nanotubes (CNTs) containing palladium (Pd) and nickel oxide (NiO) nanocomposite (Pd/NiO@rGO/CNTs nanocomposite). The synthesized nanocomposite presents remarkable performance for supercapacitor application especially in stability, exhibiting specific capacitance of 24 F/g at scan rate of 10 mV/s and excellent capacitance retention of 95% after 500 consecutive CV cycles at scan rate of 100 mV/s.
A tiled dual-polarized transmitarray with 1-bit quantization
Authors: Munina I , Turalchuk P , Kirillov V , Verevkin A , Zelenchuk D
Published: April 2020

An original approach of a transmitarray which consists of the tiled unit cells placed in a plastic holder is considered. Each unit cell represents a passive receiver-transmitter structure with integrated phase-shifter, which can take either of two coding states corresponding 180° phase difference between the states. The transmitarray design supports two orthogonal linear polarizations. An example of a 10x10 element 1-bit beam steering transmitarray operated in C-band is presented. The results of radiation pattern measurements with single and multifeed excitation are shown. The proposed structure represents a cost-efficient solution for scalable transmitarrays.
Electron-phonon interaction in colloidal CdSe quantum dots embedded in different solid matrices
Authors: Karimullin K R , Arzhanov A I , Es’kova A E , Magaryan K A , Naumov A V
Published: April 2020

Colloidal semiconductor nanocrystals (quantum dots, QD) manifest specific temperature dependent luminescence. Here we analyse temperature dependences of CdSe QD luminescence spectrum shift for different composites: polymers, glasses, crystals. The analysis was performed in the terms of electron-phonon coupling, that allows to find and compare the parameters of this interaction. The matrix influence on the T-dependence is also discussed.
Nonlinear Optical Response of Hybrid Exciton State in Quantum Dot- Dendrite Systems
Authors: Huong Nguyen Que
Published: April 2020

A “real space” Green’s function method and a diagrammatic technique are used to study the optical response of the semiconductor-organic hybrid exciton in quantum dot-dendrimer system. The energy of the hybrid exciton and the linear and non-linear susceptibilities have been calculated for a sample of quantum dot-dendron ligand. Enhanced non-linearity is obtained, which is controlable by the number of generations, the size and structure of the QD-dendrimer systems.
Synthesis of SERS-encoded nanotags: From single nanoparticles to highly brilliant complex core-satellite structures
Authors: Pazos-Perez Nicolas , Alvarez-Puebla Ramon
Published: April 2020

In this work, we report novel methods to produce SERS encoded nanoparticles (SEPs). Either as single nanoparticles (NPs) or as more complex core-satellites structures. Single NPs are produced in an easy and fast one-pot approach which, are further use as building blocks to produce the core–satellite SEPs. The presented protocols are very versatile allowing the NPs SERS codification with an extensive variety of Raman codes. Moreover, this protocol can be applied to different NPs materials and shapes. Furthermore, the core–satellite SEPs are designed to exhibit minimal interparticle distances (<2–3 nm) with maximum satellite loading (i.e., maximum number of hot spots per assembly), while positioning the encoding agents at the gaps to achieve a very high optical efficiency. In addition to such versatility, these fabrication methods are simple, cheap, scalable and robust, yielding stable SPEs in high yields.
Development of anticancer drug delivery system based on bone marrow-derived multipotent mesenchymal stem cells
Authors: Peltek Oleksii O , Muslimov Albert R , Zyuzin Mikhail V , Karpov Timofey E , Timin Alexander S
Published: April 2020

Nowadays, a number of anticancer drugs are inadmissible due to their high toxicity. However, this matter can be addressed with improvements in pharmacokinetics, which would allow to generate localized high concentrations of antitumor drugs with minimal systemic toxicity. Such an effect can be achieved by utilizing high encapsulating properties of polyelectrolyte microcapsules with further modification of therapeutically relevant cells capable of pathotropism with these microcarriers. In the present work we studied the effect of drug carrier size on the migration properties of the human multipotent mesenchymal stromal cells (MMSCs). The conducted study included experiments on internalization efficiency, overall toxicity, migration index and speed in order to optimize the properties of the resulting cell-based drug delivery system. In addition to that the ability to directed migration of modified MMSCs along the gradient of tumor-associated chemokines (SDF-1) was explored using chemotaxis slides and 3D tumor tissue model. The results demonstrated that the combination of MMSCs and drug-loaded microcapsules resulted in a delivery system which possesses the ability to actively migrate into tumors, was not toxic towards cell carriers and overall had a therapeutic potential.
Resonance absorption of visible light by subwavelength gratings
Authors: Petrov N I , Danilov V.A. , Popov V.V. , Usievich B.A.
Published: April 2020

Diffraction of light of a visible spectral range by subwavelength metal gratings is investigated theoretically and experimentally. It is demonstrated that under certain conditions an effect of plasmon resonance occurs, at which a complete absorption of the incident radiation takes place. It is shown that the influence of the incident beam width on the diffraction efficiency is significant for the incident angles, at which the plasmon resonance occurs.
Nanosecond Laser Surface Silver Metallization of Wet Ion Exchanged Glasses
Authors: Reduto I , Wackerow S , Zolotovskaya S , Abdolvand A , Lipovskii A , Svirko Yu
Published: April 2020

Silver ions are embedded in glass slides by a traditional “wet” ion exchange technique. The glass slides irradiation by 10 ns laser pulses at 355 nm wavelength leads to the formation of metal-like film at the surface. Scanning electron microscopy shows that the films presents a dense layer of silver nanoparticles about the same size and separation. Varying the irradiation parameters results in a significant difference in the transmission spectra of the slides. Particle size grows when the laser power increases.
Bound-state in the continuum of a photonic crystal metasurface: a platform for ultrasensitive sensing and near field amplification
Authors: Romano Silvia , Zito Gianluigi , Yépez Sofía Natalí Lara , Penzo Erika , Cabrini Stefano , Coppola Giuseppe , Rendina Ivo , Luca Anna Chiara De , Mocella Vito
Published: April 2020

The localization of the electromagnetic field at the nanoscale can play a key role in many applications, such as sensing, spectroscopy and energy conversion. In the last years, great efforts have been performed to study and realize all-dielectric loss-free nanostructures to confine the radiation without the limits imposed by the plasmonic systems. Here we demonstrate that the field enhancement in proximity of a photonic crystal metasurface supporting bound states in the continuum can be explored to boost the light-matter interaction. We design and realize an innovative sensing scheme for bulk and surface measurement with ultra-high figure of merit and apply this new configuration for studying a specific protein-protein interaction. The recognition scheme can be coupled to a fluorescence-based sensing approach, which exploits the capability of the sensor to strongly enhance fluorescence signals. Our results provide new solutions for light manipulation at the nanoscale, especially for sensing and nonlinear optics applications.
Coupling of SiV-containing nanodiamonds to a Fabry-Perot microcavity
Authors: Romshin A M , Kudryavtsev O S , Pasternak D G , Ekimov E A , Vlasov I I
Published: April 2020

The possibility of increasing the spontaneous emission rate for silicon-vacancy (SiV) centers in nanodiamonds placed in a Fabry-Perot microcavity was studied. For this purpose, a plano-concave open access microcavity was designed. The cavity was tested using diamond nanocrystallites, placed on a flat mirror. Nanodiamonds were synthesized from adamantane and Si-containing adamantane derivative by high pressure, high temperature (HPHT) technique. The controlled room temperature cavity coupling gives rise to a resonant Purcell enhancement of the SiV zero-phonon line by a factor 1.4.
Synthesis of Metal Oxide Nanomaterials for Early Lung Disease Detection
Authors: Sajor N J , Foronda J R , Olarve R S , Dela Torre H M , Santos M G , Lopez T B , Haygood K J , Santos G N , Koledov V , Gratowski S V
Published: April 2020

Metal oxide nanomaterials from bulk zinc oxide and tin oxide powders were synthesized via Horizontal Vapor Phase Crystal Growth deposition technique. Synthesized nanomaterials were deposited in a silica quartz tube where it acts as sensing element of the gas sensor. Volatile organic compounds (VOCs) were utilized as identifier for lung disease which served as analytes to interact with the gas sensor. The sensitivity test was measured using its response time and voltage difference. An immediate voltage response time with an average of 3 seconds was observed upon exposure of the analyte to the sensor. Selectivity test was analyzed through radar plots of tin oxide and zinc oxide which depicted that each metal oxides have distinct sensing capabilities in terms of sensed VOC gases.
Hybrid functional materials for tissue engineering: synthesis, in vivo drug release and SERS effect
Authors: Saveleva M. S. , Ivanov A. N. , Prikhozhdenko E. S. , Yashchenok A.M. , Parakhonskiy B. V. , Skirtach A. G. , Svenskaya Y. I.
Published: April 2020

The research presents the designing new hybrid biocompatible materials aimed to bone tissue engineering with enhanced osteoconductivity and functionality. The scaffolds consisted of electrospun polymeric matrix, modified with porous calcium carbonate (vaterite) coatings, were developed and studied. The subcutaneous implantation tests in vivo with white rats demonstrated the high degree of biocompatibility of vaterite-mineralized scaffolds. Moreover, the performed in vivo release of bioactive molecules, immobilized in mineral coating of scaffold, allowed to control the regeneration process in tissues in the implantation area. Also, the decoration of mineralized scaffold with silver nanoparticles exhibited the capability of exploiting these materials as effective substrates with providing surface enhanced Raman scattering (SERS) for precise detection of low concentrations of analyte. In this way, developed scaffolds can be promising materials with enhanced functionality of tissue regeneration, in vivo drug release and detection for designing novel smart devices for biomedicine.
Ultrafast all-optical GaAs nanoswitch for photonic integrated circuitry
Authors: Snigirev V S , Shorokhov A S , Sitnyansky V A , Fedyanin A A
Published: April 2020

All-dielectric nanophotonics offers favourable opportunities for engineering of devices for various practical tasks. In this regard, a very promising field is integrated photonic circuitry, where the implementation of all-dielectric components can significantly increase the performance of nanodevices. In this paper, we numerically investigate a system formed by an ultrafast all-optical switch – a GaAs dimer nanoantenna – and a GaAs strip waveguide. The simulation of the light scattering in that system shows the relative change of the waveguide transmission coefficient ∆T/T up to 12.3 % for the fluence of the pumping pulse 0.19 mJ·cm−2. This proof-of-principle result paves the way for potential applications of the system as a logic element for nanophotonic chips.
THz generation and frequency manipulation in AFM/HM interfaces
Authors: Stremoukhov Pavel , Safin Ansar , Kirilyuk Andrei
Published: April 2020

In this paper, we propose an approximate nonlinear theory of a spintronic terahertz-frequency oscillator based on antiferromagnet-heavy metal interfaces. We present a model of excitation of nonlinear oscillations of Neel vector in an antiferromagnet under the action of terahertz pulses of an electromagnetic field. We determine that, with increasing pumping pulse amplitude, the spin system response increases nonlinearly in the fundamental quasi-antiferromagnetic mode. Our results theoretically show that a spin-current flowing from a heavy metal due to the spin-Hall effect vary the frequencies of the output EM oscillations in a wide range, which could be detected by a standard pump-and-probe spectroscopy. Our study paves the way to laser-induced, electrically tunable, low-power, ultrafast AFM-based oscillator that operates without external magnetic fields at room temperature for telecommunication systems, bio-inspired networks and optical networks on chip. The nonlinear dynamics of the antiferromagnet-based emitters discussed here is of importance in terahertz-frequency spintronic technologies.
Toroidal Moments Probed by Electron Beams
Authors: Talebi Nahid , Guo Surong , Campos Alfredo , Kociak Mathieu , van Aken Peter A.
Published: April 2020

Toroidal moments have recently attracted attentions as an individual class of moments, by expanding the vector potential and decomposing the third component into toroidal moments and magnetic quadrupoles. Toroidal moments sustain peculiar time-space symmetry relations and are known as hybrid modes, which can be only understood by including retardation effects. Here, we outline our recent attempts to realize toroidal moments in void oligomeric meta-molecules. These structures are investigated experimentally using electron energy-loss spectroscopy and numerically using finite-difference time-domain method. We discuss about various toroidal moments supported by these structures, the role of symmetry and topology in excitation of these moments, the radiation from electron-induced toroidal moments resolved by cathodoluminescence spectroscopy, and finally hybridization of toroidal moments in coupled oligomers. Our findings outline the necessity of including toroidal moments within the classes of electromagnetic moments, despite the current discrepancy about their significance.
Fabrication of halide-perovskite resonant microcylinders by nanoimprint lithography
Authors: Polushkin A S , Kruk S , Malurean R , Tiguntseva E Yu , Zakhidov A , Bogdanov A A , Kivshar Y , Makarov S V
Published: April 2020

Halide perovskites are promising materials for optoelectronic devices, solar cells and various photonic applications due to their unique optical and electronic properties and low-cost fabrication. Halide perovskites micro and nanoscale structures have demonstrated high resonance properties last decade. Moreover, these materials allow high throughput creation of advanced nanophotonic designs employing nanoimprint lithography. Here, we develop this fabrication approach to create halide perovskites resonant microcylinders. Our study of the obtained microobjects demonstrates that the nanoimprint lithography yields desirable size and shape, as well as preserved photoluminescent properties of the microcylinders.
Light induced temperature decrease of semiconductor nanoparticle
Authors: Tonkaev Pavel , Zograf George , Petrov Mihail , Makarov Sergey
Published: April 2020

We demonstrate model of light induced refrigeration of single semiconductor resonant spherical nanoparticles. In this paper, we reveal that cooling efficiency can be increased by several times in comparison with bulk material due to excitation of optical Mie-resonances in the nanoparticles. We believe that such approach can be promising for the implementation of all-optical laser cooling devices.
Substrate effects in graphene field-effect transistor photodetectors
Authors: Voronin K V , Ermolaev G A , Stebunov Y V , Arsenin A V , Bylinkin A N , Jensen B B E , Jørgensen B , Volkov V S
Published: April 2020

In present study, we introduce graphene field-effect transistors (G-FET) fabricated on silicon - silicon dioxide wafers and analyse their properties. Electric and photoelectric effects in these devices were experimentally observed and discussed. We demonstrate that the understanding of the processes occurring in the substrate is of high importance not only for the development of all types of photodetectors based on field-effect transistors, but also could be used for the designing of devices with novel functionalities.
Collective magnetic modes excitation in GaAs nanoclusters by azimuthally polarized vector beams
Authors: Yagudin D F , Kroychuk M K , Shorokhov A S , Fedyanin A A
Published: April 2020

We investigate optical response of oligomers of dielectric nanodisks made of GaAs – anisotropic material with bulk quadratic nonlinearity. By using numerical approach, we analyse linear response of nanoparticle clusters in the vicinity of the magnetic dipole resonance for two types of incident radiation: linearly polarized plane wave and azimuthally polarized vector beams. Achieved results may be used to design highly efficient nonlinear optical nanoantennas with controllable radiation characteristics.
Polarization hybridization of surface waves on anisotropic metasurface
Authors: Yermakov Oleh , Hurshkainen Anna , Dobrykh Dmitry , Kapitanova Polina V. , Iorsh Ivan V. , Glybovski Stanislav B. , Bogdanov Andrey A.
Published: April 2020

In this work we conduct numerical and experimental characterization of mixed TE-TM polarized surface waves on an anisotropic metasurface in the super high frequency range (from 2 to 8 GHz). We investigate the evolution of equal frequency contours for eigenmodes. The drastic changes of the equal frequency contours shapes, called topological transitions, are observed. Finally, we experimentally demonstrate the polarization hybridization of two localized surface modes.
Simulating optical properties of extremely oblate inhomogeneous particles with the discrete dipole approximation
Authors: Smunev D A , Yurkin M A
Published: April 2020

The discrete dipole approximation (DDA) is a general volume-discretization method for simulating optical properties of arbitrary particles. We employ the formulation of the DDA with rectangular-cuboid dipoles (voxels) and analyze it in the limit of very small thicknesses of both dipole and scatterer. Taking the limit of zero thickness greatly simplifies the theoretical formulation, resulting in the Rayleigh-Debye-Gans approximation combined with the boundary conditions at the plane interface. This can also be computed in the framework of the DDA, for which we developed a specialized modification of the open-source code ADDA. We also proved that the scattering quantities computed with the standard (3D) code are independent of number of dipoles along the particle thickness, when the latter is sufficiently small. This justifies the usage of dipole monolayers for practical simulations, including those for finite-width metasurfaces.
Experimental realization of ultra-compact high-efficiency metasurface Luneburg lenses for microwave applications
Authors: Zhu Weiren , Li Jianping
Published: April 2020

Metasurfaces have shown the prospect of manipulating electromagnetic beams of various forms within a deeply subwavelength scale, which is especially useful in novel antennas designs and compact microwave devices or systems. In this paper, we present an ultra-compact, high-efficiency, and broadband metasurface Luneburg lens for full-angle operation at microwave frequencies. The design of the Luneburg lens is based on a holly parallel-plate-waveguide, where nonuniform circular holes are etched on the upper metallic plate. The gradient profile of the effective refractive index is achieved by varying the hole diameter. The high efficiency and broadband features of the proposed metasurface Luneburg lens are demonstrated numerically and experimentally. Owing to the symmetry of the Luneburg lens, such a lens is well suited for full-angle operation.
Estimation of molecular size of triglyceride in a variety of solvents by using the intrinsic viscosity technique: an important index for transesterification of triglyceride in homogenous system
Authors: Uemura Yoshimitsu , Sinnasami Ravin A/L , Trinh Thanh Hoai , Onoe Kaoru
Published: April 2020

The effect of solvent type on the molecular size and intermolecular interaction of triglyceride was investigated by the intrinsic viscosity technique. Both the indices may be important for discussing and scrutinizing the behavior of homogeneous transesterification of triglyceride with alcohol since it was found that the co-solvent type influences both the transesterification rate and hydrodynamic size of triglyceride in a homogeneous system. Kinematic viscosity of palm oil dissolved in six different solvents was measured at 298 K by using glass capillary type viscometer to determine the intrinsic viscosity and Huggins constant. By plotting the intrinsic viscosity and Huggins constant against the seven physical properties of the solvents, the polarity of the solvent has been identified as the key factor for molecular size of triglyceride in solution. On the contrary, none of the seven physical properties showed good correlation with the Higgins constant. This may be attributed to more complex nature of the Huggins constant in comparison with the intrinsic viscosity.
The effect of drying temperatures and tannin-adhesive types on bending properties and shear strength of glued Eucalyptus pellita board
Authors: Yuniarti K , Santoso A , Pari R
Published: April 2020

Eucalyptus pellita is usually harvested at young age for pulp and paper production. Therefore, it’s wood quality needs to be improved when it is used for construction. One of which is through its conversion into laminated products. Nevertheless, several factors are assumed to influence the final quality of laminated products, i.e pre-drying temperatures used to prepare the samples and the adhesives types used. This paper aims to investigate the effect of both factors on the bending properties and shear strength of glued Eucalyptus pellita boards. The Pellita boards were exposed to 2 drying temperatures (50°C and 60°C) and further laminated by using 2 tannin-based adhesives (made from the mahogany and oil palm bark extracts). The results showed the modulus of elasticity (MOE) and modulus of rupture (MOR) of the glued boards with mahogany-tannin adhesives were, respectively, 33,333.15-39,160.15 kg/cm2 and 214.30-640.77 kg/cm2 higher than the boards laminated with the oil palm wood tannin adhesives. Nevertheless, the oil palm tannin adhesives improved the shear strength of laminated Pellita, approximately 15.06-16.45 kg/cm2 higher than the boards laminated with mahogany-tannin adhesives. A further statistical test showed the tannin-types used for adhesives, and not the drying temperatures, that significantly affected the investigated mechanical properties of glued Pellita boards.
Thermosensitive and chitosan of crab (Portunus pelagicus) shells gel based adsorbent for reversible adsorption-desorption of several toxic metal ions
Authors: Ningrum E O , Bagus A , Agustiani E , Ni’mah H
Published: April 2020

Indonesia experiences environmental pollution because of wastewater treatment problems. Such occurrence is affected by the heavy metal waste produced by the electroplating industry, one of them is ferrous and nickel. Thus, heavy metal waste needs to be regenerated through a method by using zwitterionic betaine gel. However, this method has weakness in the form of intra-intrachain associations which occurs and becomes the obstacle for the ionic group’s ions adsorption ability by the charge group interaction. The purpose of this research was to increase the adsorption ability of the gel by removing the intra-intrachain copolymers association through conducting a synthesis of both the anionic gel N-isopropyl acrylamide (NIPAM) copolymerized with acrylic acid (NIPAM-co-acrylic acid) and cationic gel (NIPAM-co-chitosan), separately. The synthesis of the gels was conducted through a polymerization reaction using accelerator in the form of N, N, N’, N’-tetramethylethylenediamine (TEMED), an initiator ammonium peroxodisulfate (APS) and a cross-linker in the form of N, N’-methylenebisacrylamide (MBAA). In this research, the metal ions adsorption by pH-thermosensitive gel was conducted in various pH and weight balance between NIPAM-co- anionic and NIPAM-co-cationic gel provided. The effects of the temperature and the conditions provided in the gel preparation were also investigated, including the effect of monomer concentration on the metal ions adsorption on the gel. The gel adsorption behavior is discussed by considering the swelling degree of the gel as well as the transition temperature of poly(NIPAM-co-chitosan) and poly(NIPAM-co-acrylic acid). According to the results of FTIR analysis, the vinyl group peak of the copolymer gel decreased compared with that of its constituent monomers, thus the copolymers synthesis was successful. Meanwhile, based on the swelling degree test using the electroplating waste solution, the higher the solution’s temperature, the lower the gel’s swelling degree. In addition, the higher synthesis temperature also caused the occurrence of gel porous. The adsorption ability of the gels that have positive and negative charge groups synthesized separately is better than zwitterionic gels. The gel can adsorb more heavy metal ions at higher adsorption temperatures.
Characterization of non-oxygenates hydrocarbon product from the catalytic pyrolysis of rice straw
Authors: Mufarrid Sabiq , Lesmono Angela , Mei Jessica , Subakti Felix , Setiadi
Published: April 2020

The usage of fossil fuel as petrochemical feedstock becomes problems due to the depletion of its supply coupled with the issue of global warming and air pollution, thus a new alternative is needed. Lignocellulose biomass can be converted into hydrocarbons for the petrochemical industry’s feedstock through pyrolysis process, which is a thermal decomposition of biomass in an oxygen-free condition. The materials used in this experimental study consist of rice straw as the main feedstock, ZSM-5 as the catalyst. Rice straw is lignocellulose biomass that has the potential in Indonesia because of its abundant supply in many locations. Biomass catalytic pyrolysis was carried out using a fixed bed reactor with the varied ratios of ZSM-5 and biomass mixture and the products in the form of gaseous phase come out from the bottom of the reactor by flowing it into a glass test tube with a diameter of 2.5 cm. Pyrolysis process was carried out at temperature variations of 450°C, 500°C, and 550°C in a nitrogen gas flowing condition of 10-20 ml/minute. To detect the non-oxygenate hydrocarbon products, the sampling of the gas product was done by taken it using the glass syringe in the reactor bottom. The gas analysis was performed using Gas Chromatography-Mass Spectroscopy (GC-MS) and the calibration curve was then prepared to quantify the results by GC-MS analysis for various pyrolysis vapor compounds with their respective peak areas. With the variation of pyrolysis temperature, this study shows that the olefin group produced in catalytic pyrolysis neither does the conventional pyrolysis. But the pyrolysis produced the paraffin group in any type of pyrolysis condition process. This study also found that olefin group production was decreased in the longer time of stream reaction, while the aromatic group was increased. Generally, the amount of aromatic compound formation depends on catalyst ratio.
Simulation of livestock biomass resource recycling and energy utilization model based on dry type methane fermentation system
Authors: Kimura Yoshiaki , Suzuki Takeshi , Yaasui Seiichi , Ishii Kota , Kaziyama Tsutomu , Oishi Kazato , Ogino Akifumi , Hinata Takahisa , Hirooka Hiroyuki , Osada Takashi , Fujita Haruhiro
Published: April 2020

This study was aimed at investigating the local livestock biomass volume for dairy farms in Town A, located in eastern Hokkaido, Japan, and at presenting a model of a biogas plant that enables maximizing the use of the available livestock biomass. Using a dairy farm with 250 animals in Town A as a model for a biogas plant based on dry-type methane fermentation system (dry-type biogas plant), we set the operational conditions to an average hydraulic retention time of 20 days, digestion temperature of 55°C, and methane gas yield of 0.12 Nm3 CH4/kg VSA. We compared the biogas production of our presented model with that of a wet-type biogas plant with the same number of animals. The results showed that the dry-type biogas plant produced biogas at 859 Nm3/day, while the wet-type biogas plant produced biogas at 666 Nm3/day. These results indicate that introducing dry-type biogas plants in all dairy farms in Town A would potentially enable semi-solid livestock manure to be processed, which is not amenable to ordinary composting, in addition to the conventional processes being carried out through biogas plants, as well as lead to an increase in the amount of biogas production.
The effects of magnesium sulphate addition into foaming agents resulted from palm oil fatty acid saponification in the performance of peat fire suppression
Authors: Subekti P , Hambali E , Suryani A , Suryadarma P , Saharjo B H , Rivai M
Published: April 2020

The utilization of foaming agents resulted from the saponification of palm oil fatty acids as foam concentrate on peat fire suppression leads to less water use and a shorter time compared to the use of peat water only. The development of foaming agents for a peat fire extinguisher, including the addition of 0.2% magnesium sulfate (MgSO4), was further conducted in order to improve the performance of the liquid foam. This study aims to determine the performance of the developed foaming agent (FAP-MS) applied in peat fire suppression. In order to assess the performance of FAP-MS, two controls namely palm fatty acid-based foaming agent without the addition of magnesium sulfate (FAP) and peat water with no mixture of foaming agents were used. Results showed that the durability of foam produced from the peat water solution mixed with FAP-MS was lower than the foam produced from the peat water solution mixed with FAP. The addition of FAP-MS into peat water solution was found to reduce the use of water by 27% and the addition of FAP reduced it further by 35%. However, compared to peat water with no foaming agent addition, FAP-MS and FAP additions were able to suppression peat fires faster by 79% and 65%, respectively.
The effect of sodium carbonate and saccharides on mono-diacylglycerol (M-DAG) purification
Authors: Setyaningsih Dwi , Warsiki Endang , Ulfa Sonia Fitria , Muna Neli
Published: April 2020

Mono-diacylglycerol (M-DAG) in this research was produced from the esterification reaction of Palm Fatty Acid Distillate (PFAD) and glycerol. Crude M-DAG from esterification had low purity, due to the remaining free fatty acids, glycerol and triglycerides. Thus, purification with saponification to remove free fatty acids, solvent extractionand crystallization to separate M-DAG from triglycerides was needed. This study aimed to determine the best sodium carbonate (NaHCO3) concentration (2.5, 5, 7.5, and 10%) in saponification reaction and to investigate the effect of saccharides (glucose, GOS, and maltodextrin) addition as a seed in M-DAG crystallization. The best sodium carbonate concentration was 10% (w/w) with the yield of 49.33%, 20.47% FFA content, 0.8% ash, pH 7.28, 69.6% emulsion stability, 0.29% total glycerol, and 0.03% free glycerol. Crystallization with glucose produced the yield of 34.21%, 15.69% FFA, 1.02% ash, 11.02% water content, pH 7.1, 87.82% emulsion stability, 0.35% total glycerol and 0.04% free glycerol. However, addition of saccharides had no significant effect on the quality of pure M-DAG.
Effect of microwave irradiation on the etherification of biodiesel-derived glycerol in a solvent free process
Authors: Ayoub Muhammad , Yusoff Mohd Hizami Mohd , Yusup Suzana Bt , Danish Mohammed , Ullah Sami , Farrukh Sarah
Published: April 2020

This study revolves mainly about the effect of etherification of glycerol to polyglycerols using a heterogeneous catalyst under microwave radiation. Microwave radiation serves as a purpose to shorten the reaction time of the procedure. Cerium Nitrate and Lithium Nitrate was used to modify montmorillonite K-10 clay (MK-10) which was then used to catalyze the etherification process. They were several reaction parameters that were observed for this study which were: catalyst concentration and reaction time. The parameter that played a vital role was the catalyst concentration which affected the percentage conversion of glycerol, selectivity of pentaglycerols, selectivity of cyclic diglycerols and undesired cyclic diglycerols. It was observed that with a high temperature and high reaction time, the amount of undesired cyclic glycerol was increased. Optimum amount of catalyst conversion promoted higher amount of desired cyclic glycerol. Longer reaction time is needed to produce higher yield and selectivity. The production of undesired cyclic diglycerol can be removed with the help of vacuum distillation. The highest glycerol conversion was found of 94% with highest yield of desired products of 70% polyglycerol at 260 °C and 5 h of reaction time. The selectivity towards undesired high order polyglycerol was found 24% at same reaction conditions.
Fault location of power communication network based on dichotomy search algorithm
Authors: LiChao  , Youjun Hu , hao Zhang , Wenqiang Zhang
Published: April 2020

In the quality degradation fault location of the power communication network, the focus of the power communication network quality degradation fault location is to reduce the test packet transmission and speed up the fault location time on the basis of accurate positioning. This paper first analyzes the traditional solar winds segment-by-segment detection and related research, which has a long positioning time, a large number of packets, and the continuous crowding of communication resources at the normal communication link during the test. In this paper, binary search algorithm is applied in fault location, at the same time, source and destination nodes are orderedly exchanged during fault location. Finally, the advantages of this method in reducing positioning time, reducing the test case packets and resource crowding are verified through simulation and engineering practice.
Research on Prediction Model of Cable Line Cost Based on Least Square Support Vector Machine
Authors: Yu Bo , Gou Ruixin , Ju Xin , Wei Dongni
Published: April 2020

With the development of China’s economy and society, the total social electricity consumption has risen dramatically, and the investment scale of transmission and transformation projects has increased accordingly. Cable line engineering is a kind of power transmission and transformation engineering, which is buried deep underground, has complex construction conditions and high cost. Compared with substation engineering and overhead line engineering, its cost control is more difficult. In order to facilitate the fine management of cable line cost, this paper analyses the influencing factors of cable project cost based on grey relational analysis theory, uses principal component analysis method to reduce the dimension of influencing factors, and establishes a cable line cost prediction model based on least squares support vector machine method. It can guide the economic evaluation of investment decision of cable line project. The results show that the accuracy of the cost prediction model based on least squares support vector machine method can reach 95.06%. The research in this paper is innovative and practical.
Measuring China’s Energy and Power Development Based on Mathematical Models
Authors: Wu Hao
Published: April 2020

From the spontaneous use of natural energy by humans to the conscious use of fossil energy after the industrial revolution and the energy use that is currently entering the stage of intelligence, energy plays an important role in promoting and promoting human progress and social development. Simultaneously, due to the massive development of fossil energy, serious ecological damage has been caused, and it has threatened human survival. Clean energy and low carbon have become the development strategies of all countries in the world. Based on the advantages of resources, China has formed a coal-based energy structure. While ensuring China’s social and economic development, energy has also produced serious pollution. In particular, carbon emissions have ranked first in the world for many years, accounting for 28% of the global total in 2018. The pressure to reduce emissions is huge, and energy transformation is imminent. This paper analyzes China’s energy status and challenges, predicts China’s energy development trends in 2030 based on numerical values, and quantifies the development space of various energy sources.
Research on DC Cross-regional Accommodation Model Based on Scene Analysis
Authors: Zhongming XIANG , Wenjin CHEN , Jun ZHANG , Bo WANG , Xu HE , Feng LI
Published: April 2020

In order to cope with the impact of uncertainty of the renewable energy forecasting in two regions on the cross-regional accommodation of renewable energy, a DC cross-regional accommodation model based on scene analysis is established. Firstly, the ARMA model, scene reduction and scene combination concept are used to construct the scene set describing the uncertainty of the renewable energy forecasting in two regions. Then, the model is used to obtain the unit start-stop plan in two regions and the DC line transmission plan with the goal of smallest renewable energy power abandonment statistically. Finally, based on the measured data of renewable energy power generation, the unit power generation schedule with the goal of smallest renewable energy power abandonment in the actual operation of the power grid is obtained. The validity of the model is verified by a cross-regional system example of actual data reconstruction in a province.
Design and Modeling of Parallel Two-degree-of-freedom Variable Stiffness Actuator
Authors: Yang Shangkui , Chen Peng , Cao Yongzhan , Zhu Shuyun , Ge Zhuang , Liu Yuwang
Published: April 2020

In this paper, a new 2-DOF variable stiffness actuator based on a 2-DOF spherical wrist parallel mechanism is proposed. A 2-DOF VSA based on a parallel ball wrist mechanism and a parallel arrangement of leaf spring sets is used. Control its stiffness adjustment, analysis its variable stiffness principle and actuator mechanical structure. The parallel arrangement of the leaf spring groups reduces the mass and volume of the joints, enabling simultaneous adjustment of the stiffness. The analytical formula of the rotational stiffness of the actuator is established according to the geometric nonlinearity of the large deflection of the leaf spring.
Remote status monitoring based on ESP8266 connected IoT cloud platform
Authors: Hu Haichen , Li Yinghao
Published: April 2020

This paper applies the Internet of Things cloud platform technology to traditional state monitoring. The method of accessing the cloud platform through the ESP8266 module is proposed. This method reduces the requirement of the longest connection distance of the intelligent monitoring connection mode, and improves the rapidity of remote monitoring, and improves the real-time and convenience of monitoring target monitoring as a whole.
NQI Status and Demand Analysis of Intelligent Electric Energy Meter Industry
Authors: Angang Zheng , Yinghui Xu , Huaiying Shang , Yan Liu , Wulei Zhang , Qi Zhang
Published: April 2020

Taking the opportunity of undertaking the project of “NQI Typical Demonstration Application” of the key research and development projects of the state, and taking the intelligent electric energy meter as the breakthrough point, the production and use process of intelligent electric energy meter in the whole life cycle is summarized as eight links: research and development design, material purchasing, production and manufacturing, factory supply, acceptance and inspection, storage and distribution, installation and operation, dismantling of scrap and so on, and the status of National Quality Infrastructure (NQI) in intelligent electric energy meter industry is carded out. At the same time, the paper summarizes the development needs of intelligent electric energy meter industry in measurement, standards, inspection, certification and accreditation, which provides guidance and basis for the construction of NQI in smart grid measurement field.
Methods for Measuring Permanent Deformation and Error Analysis of in-service Connecting Pieces of Narrow-gauge Mine Car
Authors: Bian Jianchao , Ma Yunlong , Zou Xiaoxu , Chen Fandong
Published: April 2020

According to the analysis of the different methods for measuring set deformation volume, this paper finds out the reason of these errors. New method is applied in terms of the latest standard and based on which, a small frock is designed and manufactured, thus solving the measurement precision and instrument installation problems. Through further theoretical analysis, the various forms of the errors are displayed, and the errors are figured qualitatively. Deformation of calibration point is analyzed and verified by finite element software, and the results are in line with expectations. Measurements of decreasing the errors are taken, obtaining experience for such tests.
Simulation Analysis of Single Hole Steam Jet Noise
Authors: Xingsheng Lao , Yong Liu , Chunhui Dai , Jun Wu , Zhenxing Zhao
Published: April 2020

In order to improve the low noise design level of the steam pipeline, the single-hole jet noise with a hole diameter of 10 mm was simulated and analyzed employing a DN125mm steam pipeline. The calculation results show that the in-tube injection has a distinct velocity potential nuclear region, and the vortex generated by the injection is changeas as the flow direction changes. The closer the nozzle is, the smaller the vortex volume at the nozzle is as well as the higher the radiation noise frequency is. The injection noise has obvious directivity. the closer the position is to the center line, the stronger the total sound pressure level is, and the farther the distance is, the total sound pressure level is relatively low.