bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of a controlled shock wave delivered by a pneumatic table-top gas driven shock tube
Authors: Swietek Bogumila , Skotak Maciej , Chandra Namas , Pfister Bryan J.
Published: July 2019

Blast simulators facilitate the creation of shock waves and measurement of pressure morphology in a controlled laboratory setting and are currently a vital model for replicating blast-induced neurotrauma. Due to the maintenance and operation cost of conventional blast simulators, we developed a pneumatic, table-top, gas-driven shock tube to test an alternative method of shock wave generation using a membrane-less driver section. Its unique operational mechanism based on air gun technology does not rely on a plastic membrane rupture for the generation of pressure pulses, allowing the simulator to be quickly reset and thus decreasing the experimental turnaround time. The focus of this study is to demonstrate that this proof-of-concept device can generate shock waves with diverse characteristics based on the selection of driver gas, driver pressurization, and driven section material. Pressure waves were generated using compressed nitrogen or helium at 15 psig and 80 psig and were analyzed based on their velocity and profile shape characteristics. At 15 psig, independent of the type of driver gas, driver pressurization, and driven section material, pressure pulses travelled at sonic velocities. At 80 psig, generation of shock waves was observed in all conditions. The choice of the driver gas affected the velocities of the resulting pressure waves and the shape of pressure waveforms, particularly the peak overpressure and rise time values. Our results demonstrate that depending on the selection of driver gas and magnitude of driver pressurization, the shock wave signatures can be controlled and altered using a piston-based driver section.
Heterodyne detection of radio-frequency electric fields using point defects in silicon carbide
Authors: Wolfowicz Gary , Anderson Christopher P. , Whiteley Samuel J. , Awschalom David D.
Published: July 2019

Sensing electric fields with high sensitivity, high spatial resolution, and at radio frequencies can be challenging to realize. Recently, point defects in silicon carbide have shown their ability to measure local electric fields by optical conversion of their charge state. Here, we report the combination of heterodyne detection with charge-based electric field sensing, solving many of the previous limitations of this technique. Owing to the nonlinear response of the charge conversion to electric fields, the application of a separate “pump” electric field results in a detection sensitivity as low as 1.1 (V/cm)/Hz, with a near-diffraction limited spatial resolution and tunable control of the sensor dynamic range. In addition, we show both incoherent and coherent heterodyne detection, allowing measurements of either unknown random fields or synchronized fields with higher sensitivities. Finally, we demonstrate in-plane vector measurements of the electric field by combining orthogonal pump electric fields. Overall, this work establishes charge-based measurements as highly relevant for solid-state defect sensing.
Is the λ-transition in liquid sulfur a fragile-to-strong transition?
Authors: Yuan Bing , Aitken Bruce , Sen Sabyasachi
Published: July 2019

The abrupt and large increase in the viscosity of liquid sulfur above the λ-transition temperature Tλ corresponds to a reversible structural transformation in the form of a ring-to-chain polymerization reaction. The mechanistic connection between this structural transformation and viscosity is investigated by studying the compositional dependence of the shear relaxation behavior of supercooled SxSe100−x liquids as their structural evolution mimics that of liquid sulfur across the λ-transition. The results of steady and oscillatory shear parallel-plate rheometry indicate that the viscosity of these liquids is controlled by the S/Se–S/Se bond scission/renewal dynamics and the time scale of these dynamics rapidly increases as the relative concentrations of rings and chains in the structure become comparable. The coexistence of these two types of topological units in these liquids lowers the conformational entropy of the chain elements due to a steric hindrance from the ring elements, resulting in a rapid drop in the fragility as S is added to Se. The same topological effect resulting from the ring-to-chain transformation in liquid S renders the highly fragile molecular liquid below Tλ, a strong polymerized liquid above Tλ. Therefore, it is argued that the λ-transition of liquid S corresponds to a fragile-to-strong liquid-liquid transition.
A comprehensive assessment of the low-temperature thermal properties and thermodynamic functions of CeO2
Authors: Morrison Tyler D. , Wood Elizabeth Sooby , Weck Phillippe F. , Kim Eunja , Woo Sung Oh , Nelson Andrew T. , Naugle Donald G.
Published: July 2019

Reported is an experimental and computational investigation of the low temperature heat capacity, thermodynamic functions, and thermal conductivity of stoichiometric, polycrystalline CeO2. The experimentally measured heat capacity at T < 15 K provides an important correction to the historically accepted experimental values, and the low temperature thermal conductivity serves as the most comprehensive data set at T < 400 K available. Below 10 K, the heat capacity is observed to obey the Debye T3 law, with a Debye temperature of ΘD = 455 K. The entropy, enthalpy, and Gibbs free energy functions are obtained from the experimental heat capacity and compared with predictions from Hubbard-corrected density functional perturbation theory calculations using the Perdew, Burke, and Ernzerhof parameterization revised for solids. The thermal conductivity is determined using the Maldonado continuous measurement technique, along with laser flash analysis, and analyzed according to the Klemens-Callaway model.
Control of vortex chirality in bi-component magnetic nanodisks
Authors: Manzin Alessandra , Ferrero Riccardo
Published: July 2019

In the last decade, special attention has been paid to the nucleation and control of the vortex state in magnetic nanostructures, for possible applications in nonvolatile magnetic random access memories and logic networks. Here, we study bicomponent magnetic nanodisks, in both single and 2D array arrangements, as potential storage systems where the information unit is represented by vortex chirality (magnetization rotational direction). We mainly focus on 300 nm diameter disks made of a permalloy lens and an iron crescent, with variable locations of the permalloy-iron interface. Through an extensive micromagnetic modeling analysis, we demonstrate the possibility of tuning, via the application of a magnetic field parallel to the interface, the nucleation of the vortex (always occurring in the permalloy region), its motion up to the expulsion site, and its chirality. Moreover, we find that the vortex stability is preserved over a wide field range also for strongly packed disks, due to the reduced effects of interdisk magnetostatic coupling. The main features of the magnetization reversal mechanism are preserved by reducing the disk diameter up to about 60 nm, making possible their exploitation in concept devices for magnetic encoding and logic computation.
Substituent effects on energetics and crystal morphology modulate singlet fission in 9,10-bis(phenylethynyl)anthracenes
Authors: Bae Youn Jue , Christensen Joseph A. , Kang Gyeongwon , Zhou Jiawang , Young Ryan M. , Wu Yi-Lin , Van Duyne Richard P. , Schatz George C. , Wasielewski Michael R.
Published: July 2019

Singlet fission (SF) converts a singlet exciton into two triplet excitons in two or more electronically coupled organic chromophores, which may then be used to increase solar cell efficiency. Many known SF chromophores are unsuitable for device applications due to chemical instability or low triplet state energies. The results described here show that efficient SF occurs in derivatives of 9,10-bis(phenylethynyl)anthracene (BPEA), which is a highly robust and tunable chromophore. Fluoro and methoxy substituents at the 4- and 4′-positions of the BPEA phenyl groups control the intermolecular packing in the crystal structure, which alters the interchromophore electronic coupling, while also changing the SF energetics. The lowest excited singlet state (S1) energy of 4,4′-difluoro-BPEA is higher than that of BPEA so that the increased thermodynamic favorability of SF results in a (16 ± 2 ps)−1 SF rate and a 180% ± 16% triplet yield, which is about an order of magnitude faster than BPEA with a comparable triplet yield. By contrast, 4-fluoro-4′-methoxy-BPEA and 4,4′-dimethoxy-BPEA have slower SF rates, (90 ± 20 ps)−1 and (120 ± 10 ps)−1, and lower triplet yields, (110 ± 4)% and (168 ± 7)%, respectively, than 4,4′-difluoro-BPEA. These differences are attributed to changes in the crystal structure controlling interchromophore electronic coupling as well as SF energetics in these polycrystalline solids.
Collaborative effect of plasmon-induced resonance energy and electron transfer on the interfacial electron injection dynamics of dye-sensitized solar cell
Authors: Zhang Bin , Zhao Yi , Liang WanZhen
Published: July 2019

It has been widely recognized that plasmonic metal nanoparticles (MNPs) can enhance the power convention efficiency (PCE) of dye-sensitized solar cells (DSSCs). This enhancement is ascribed to the combined effects of plasmon decay, scattering, near-field enhancement, and exciting charge carriers in semiconductors through plasmon-induced resonance energy transfer (PIRET) and hot electron injection (HEI). PIRET and HEI processes appeared between MNPs, and semiconductors have been intensively investigated; however, it is not clear how the collaborative effect of PIRET and photon-induced direct and indirect electron transfer (PICT) occurred between plasmonic metals and dyes, and the interference of different charge separation channels (CSCs) starting from PIRET and PICT affects the PCE of DSSCs. This work aims to address these issues. We apply a model Hamiltonian method, which obviously includes both PIRET and PICT processes from Au MNP to dye molecules and incorporates the dye’s electron-phonon interaction, to investigate the carrier dynamics. It is found that PIRET deforms the wavepacket dynamics of the molecular excited state and results in ten-fold enhancement of dye absorption. MNPs augment light absorption and increase the electron density in empty molecular orbitals of the dye molecule. Consequently, this enhances the interfacial charge separation. Furthermore, we observed the interference behavior of two CSCs and gave a full-scale insight into the correlation between the constructive/destructive interference and the electronic-state properties as well as carrier-phonon interactions. This work provides a theoretical guidance to optimize DSSCs.
Identification of candidate genes for lutein esterification in common wheat (Triticum aestivum) using physical mapping and genomics tools
Authors: Ávila C. M. , Palomino M. C. , Hornero-Méndez D. , Atienza S. G.
Published: July 2019

A high carotenoid content is important for the production of pasta from durum wheat (Triticum durum Desf.) and yellow alkaline noodle from common wheat (T. aestivum L.). Carotenoid esters are more stable than free carotenoid during storage and processing, and thus they allow a higher retention through the food chain. Chromosome 7D carries gene(s) for lutein esterification. The aim of this study was the physical mapping of the gene(s) for lutein esterification on chromosome 7D and the identification of candidate genes for this trait. We developed crosses between a set of deletion lines for chromosome 7D in Chinese Spring (CS) background and the CS–Hordeum chilense substitution line CS(7D)7Hch. The F2 progeny derived from the deletion line 7DS4 produced a lower amount of lutein esters, which indicates that the main gene for lutein esterification is in the region of chromosome 7D lacking in 7DS4. Other gene(s) are contributing to lutein esterification because small amounts of lutein esters are produced in 7DS4. Genotyping by DArTSeq revealed that 7DS4 lacks a 127.7 Mb region of 7DS. A set of 10 candidate genes for lutein esterification was identified by using the wheat reference genome sequence along with the Wheat Expression Browser. This region contains the Lute locus previously identified in a different genetic background. Four genes with acyltransferase or GDSL esterase/lipase activity were identified in the vicinity of Lute. Our results indicate that the gene TraesCS7D01G094000 is a likely candidate for Lute but the gene TraesCS7D01G093200 cannot be ruled out. The candidate genes reported in this work are worthy for further investigation.
TMEM203 is a binding partner and regulator of STING-mediated inflammatory signaling in macrophages
Authors: Li Yang , James Sharmy J. , Wyllie David H. , Wynne Claire , Czibula Agnes , Bukhari Ahmed , Pye Katherine , Bte Mustafah Seri Musfirah , Fajka-Boja Roberta , Szabo Eniko , Angyal Adrienn , Hegedus Zoltan , Kovacs Laszlo , Hill Adrian V. S. , Jefferies Caroline A. , Wilson Heather L. , Yongliang Zhang , Kiss-Toth Endre
Published: July 2019

Significance

Activators of interferons have received a great deal of interest in recent decades, both due to the central role they play in host defense against a range of pathogens, as well as the now well-recognized importance of dysregulated interferon activation/signaling in the pathogenesis of a number of highly prevalent and hard-to-treat diseases, such as systemic lupus erythematosus (SLE). Therefore, novel regulators of interferon activation are being sought as they may provide better targets to treat these diseases. We report the discovery of TMEM203 as an SLE-associated gene and a regulator of ligand-dependent activation of interferon production via STING. Thus, our work could form the basis of a novel therapeutic strategy for the treatment of interferonopathies, including SLE.
Hippocampal deletion of Na
V
1.1 channels in mice causes thermal seizures and cognitive deficit characteristic of Dravet Syndrome
Authors: Stein Rachael E. , Kaplan Joshua S. , Li Jin , Catterall William A.
Published: July 2019

Significance

Dravet Syndrome is an intractable epileptic disorder that includes cognitive and social-interaction deficits. It is caused by loss-of-function mutations in the brain sodium channel Na
V
1.1. We asked whether symptoms of Dravet Syndrome could be induced by introducing the mutation only in the hippocampus, a brain region important for learning and memory and for control of brain excitability. Local mutation of Na
V
1.1 specifically reduced the excitability of inhibitory neurons in the hippocampus. This local mutation caused thermally evoked seizures and spatial learning deficits, which are brain-wide effects. Our results point to a key role for the hippocampus in generating epilepsy and cognitive deficit in Dravet Syndrome and suggest that gene therapy targeting the hippocampus might be effective in this devastating disease.
Rotation of polarization in the gravitational field of a laser beam—Faraday effect and optical activity
Authors: Schneiter Fabienne , Rätzel Dennis , Braun Daniel
Published: July 2019

We investigate the rotation of the polarization of a light ray propagating in the gravitational field of a circularly polarized laser beam. The rotation consists of a reciprocal part due to gravitational optical activity, and a non-reciprocal part due to the gravitational Faraday effect. We discuss how to distinguish the two effects: letting light propagate back and forth between two mirrors, the rotation due to gravitational optical activity cancels while the rotation due to the gravitational Faraday effect accumulates. In contrast, the rotation due to both effects accumulates in a ring cavity and a situation can be created in which gravitational optical activity dominates. Such setups amplify the effects by up to five orders of magnitude, which however is not enough to make them measurable with state of the art technology. The effects are of conceptual interest as they reveal gravitational spin–spin coupling in the realm of classical general relativity, a phenomenon which occurs in perturbative quantum gravity.
Roadmap on photonic, electronic and atomic collision physics: I. Light–matter interaction
Authors: Ueda Kiyoshi , Sokell Emma , Schippers Stefan , Aumayr Friedrich , Sadeghpour Hossein , Burgdörfer Joachim , Lemell Christoph , Tong Xiao-Min , Pfeifer Thomas , Calegari Francesca , Palacios Alicia , Martin Fernando , Corkum Paul , Sansone Giuseppe , Gryzlova Elena V , Grum-Grzhimailo Alexei N , Piancastelli Maria Novella , Weber Peter M , Steinle Tobias , Amini Kasra , Biegert Jens , Berrah Nora , Kukk Edwin , Santra Robin , Müller Alfred , Dowek Danielle , Lucchese Robert R , McCurdy C William , Bolognesi Paola , Avaldi Lorenzo , Jahnke Till , Schöffler Markus S , Dörner Reinhard , Mairesse Yann , Nahon Laurent , Smirnova Olga , Schlathölter Thomas , Campbell Eleanor E B , Rost Jan-Michael , Meyer Michael , Tanaka Kazuo A
Published: July 2019

We publish three Roadmaps on photonic, electronic and atomic collision physics in order to celebrate the 60th anniversary of the ICPEAC conference. In Roadmap I, we focus on the light–matter interaction. In this area, studies of ultrafast electronic and molecular dynamics have been rapidly growing, with the advent of new light sources such as attosecond lasers and x-ray free electron lasers. In parallel, experiments with established synchrotron radiation sources and femtosecond lasers using cutting-edge detection schemes are revealing new scientific insights that have never been exploited. Relevant theories are also being rapidly developed. Target samples for photon-impact experiments are expanding from atoms and small molecules to complex systems such as biomolecules, fullerene, clusters and solids. This Roadmap aims to look back along the road, explaining the development of these fields, and look forward, collecting contributions from twenty leading groups from the field.
Visualization of gold fiducial markers in the prostate using phase-cycled bSSFP imaging for MRI-only radiotherapy
Authors: Shcherbakova Yulia , Bartels Lambertus W , Mandija Stefano , Beld Ellis , Seevinck Peter R , van der Voort van Zyp Jochem R N , Kerkmeijer Linda G W , Moonen Chrit T W , Lagendijk Jan J W , van den Berg Cornelis A T
Published: July 2019

In this work, we present a new method for visualization of fiducial markers (FMs) in the prostate for MRI-only radiotherapy with a positive contrast directly at the MR console. The method is based on high bandwidth phase-cycled balanced steady-state free precession (bSSFP) sequence, which is available on many clinical scanners, does not require any additional post-processing or software, and has a higher signal-to-noise (SNR) compared to conventional gradient-echo (GE) imaging. Complex phase-cycled bSSFP data is acquired with different RF phase increment settings such that the manifestation of the artifacts around FMs in the acquired complex images is different for each dynamic acquisition and depends on the RF phase increment used.

First, we performed numerical simulations to investigate the complex-valued phase-cycled bSSFP signal in the presence of a gold FM, and to investigate the relation of the true physical location of the FM with the geometrical manifestation of the artifacts. Next, to validate the simulations, we performed phantoms and in vivo studies and compared the experimentally obtained artifacts with those predicted in simulations. The accuracy of the method was assessed by comparing the distances between the FM’s centers and the center of mass of FMs system measured using phase-cycled bSSFP MR images and using reference CT (or MRI-only) images.

The results show accurate (within 1 mm) matching of FMs localization between CT and MR images on five patients, proving the feasibility of in vivo FMs detection on MR images only. The FMs show a positive contrast with respect to the prostate background on real/imaginary phase-cycled bSSFP images, which was confirmed by simulations.

The proposed method facilitates robust FMs visualization with positive contrast directly at the MR console, allowing RT technicians to obtain immediate feedback on the anticipated feasibility of accurate FMs localization while the patient is being scanned.
Symmetry breaking in molecular artificial graphene
Authors: Yan Linghao , Hua Muqing , Zhang Qiushi , Ngai Tsz Ue , Guo Zesheng , Wu Tsz Chun , Wang Tong , Lin Nian
Published: July 2019

Symmetry breaking in graphene has profound impacts on its physical properties. Here we emulate symmetry breaking in artificial graphene systems by assembling coronene molecules on a Cu(111) surface. We apply two strategies: (1) differentiating the on-site energy of two sublattices of a honeycomb lattice and (2) uniaxially compressing a honeycomb lattice. The first one breaks the inversion symmetry while the second one merges the Dirac cones. The scanning tunneling spectroscopy shows that in both cases the local density of states undergo characteristic changes. Muffin-tin simulations reveal that the observed changes are associated with a band gap opened at the Dirac point. Furthermore, we propose that using larger molecules or molecules strongly scattering the surface state electrons can induce an indirect gap.
Magneto-optical conductance of Kane fermion gas in low frequencies
Authors: Luo Xi , Chen Yu-Ge , Yu Yue
Published: July 2019

Kane fermion is the counterpart of the Dirac fermion with pseudospin-1. Due to the existence of a bunch of gapless modes associated with Landau levels, the magnetic transport property of Kane fermion gas is very different from that of the Dirac semimetal. We calculate the magneto-optical conductance of the Kane fermion gas. We find that these gapless modes will contribute to a series of resonant peaks in low frequencies. We find that these peaks can explain the low frequency absorbance spectrum in a recent experiment for the Kane fermion material Hg1−x
Cd
x
Te.
Generation of relativistic high-order-mode laser pulse using plasma waveguide
Authors: Yu D Y , Zou D B , Yu M Y , Yu T P , Yin Y , Shao F Q , Zhuo H B , Zhou C T , Ruan S C
Published: July 2019

An all-optical method for generating ultra-intense high-order-mode light pulse is investigated with three-dimensional particle-in-cell simulation. We find that the conversion from a short intense circularly polarized incident Gaussian laser pulse into a transverse magnetic (TM) mode occurs as it propagates into a micro plasma waveguide. The strength of the longitudinal electric field of the excited TM modes can be almost two orders of magnitude higher than that of the original laser. The simulation results show that, for the lower-order modes, the trapped electrons lead to their revolving transverse structures. A linear plasma waveguide model is presented to predict the mode pattern and intensity of the longitudinal electric fields, which are in excellent agreement with those in the simulations. Relativistic-intense high-order-mode light can be useful for many applications, including accelerating charged particles to high energies.
Quantum process identification: a method for characterizing non-markovian quantum dynamics
Authors: Bennink Ryan S , Lougovski Pavel
Published: July 2019

Established methods for characterizing quantum information processes do not capture non-Markovian (history-dependent) behaviors that occur in real systems. These methods model a quantum process as a fixed map on the state space of a predefined system of interest. Such a map averages over the system’s environment, which may retain some effect of its past interactions with the system and thus have a history-dependent influence on the system. Although the theory of non-Markovian quantum dynamics is currently an active area of research, a systematic characterization method based on a general representation of non-Markovian dynamics has been lacking. In this article we present a systematic method for experimentally characterizing the dynamics of open quantum systems. Our method, which we call quantum process identification (QPI), is based on a general theoretical framework which relates the (non-Markovian) evolution of a system over an extended period of time to a time-local (Markovian) process involving the system and an effective environment. In practical terms, QPI uses time-resolved tomographic measurements of a quantum system to construct a dynamical model with as many dynamical variables as are necessary to reproduce the evolution of the system. Through numerical simulations, we demonstrate that QPI can be used to characterize qubit operations with non-Markovian errors arising from realistic dynamics including control drift, coherent leakage, and coherent interaction with material impurities.
Interpretation of suprathermal emission at deuteron cyclotron harmonics from deuterium plasmas heated by neutral beam injection in the KSTAR tokamak
Authors: Chapman B. , Dendy R.O. , Chapman S.C. , McClements K.G. , Yun G.S. , Thatipamula S.G. , Kim M.H.
Published: July 2019

Intense bursts of suprathermal radiation, with spectral peaks at frequencies corresponding to the deuteron cyclotron frequency in the outer midplane edge region, are often detected from deuterium plasmas in the KSTAR tokamak that are heated by tangential neutral beam injection (NBI) of deuterons at 100 keV. Identifying the physical process by which this deuterium ion cyclotron emission (ICE) is generated, typically during the crash of edge localised modes, assists the understanding of collective energetic ion behaviour in tokamak plasmas. In the context of KSTAR deuterium plasmas, it is also important to distinguish deuterium ICE from the ICE at cyclotron harmonics of fusion-born protons examined by Chapman et al (2017 Nucl. Fusion
57 124004; 2018 Nucl. Fusion
58 096027). We use particle orbit studies in KSTAR-relevant magnetic field geometry, combined with a linear analytical treatment of the magnetoacoustic cyclotron instability (MCI), to identify the sub-population of freshly ionised NBI deuterons that is likely to excite deuterium ICE. These deuterons are then represented as an energetic minority, together with the majority thermal deuteron population and electrons, in first principles kinetic particle-in-cell (PIC) computational studies. By solving the Maxwell–Lorentz equations directly for hundreds of millions of interacting particles with resolved gyro-orbits, together with the self-consistent electric and magnetic fields, the PIC approach enables us to study the collective relaxation of the energetic deuterons through the linear phase and deep into the saturated regime. The Fourier transform of the excited fields displays strong spectral peaks at multiple successive deuteron cyclotron harmonics, mapping well to the observed KSTAR deuterium ICE spectra. This outcome, combined with the time-evolution of the energy densities of the different particle populations and electric and magnetic field components seen in the PIC computations, supports our identification of the driving sub-population of NBI deuterons, and the hypothesis that its relaxation through the MCI generates the observed deuterium ICE signal. We conclude that the physical origin of this signal in KSTAR is indeed distinct from that of KSTAR proton ICE, and is in the same category as the NBI-driven ICE seen notably in the TFTR tokamak and LHD heliotron–stellarator plasmas. ICE has been proposed as a potential passive diagnostic of energetic particle populations in ITER plasmas; this is assisted by clarifying and extending the physics basis of ICE in contemporary magnetically confined plasmas.
A comparative study of hybrid simulation and dynamical substructuring system schemes for shake table tests
Authors: Enokida Ryuta
Published: July 2019

In shaking table experiments, the dynamics of the shake table is strongly affected by a specimen to be tested, particularly when the specimen is very heavy. This is also the case when substructuring experiments are implemented by the shaking tables. This study numerically examines two substructuring schemes applied in shaking table experiments. Hybrid simulation scheme, which is commonly used in substructuring experiments, directly uses the output of the numerical substructure as the input to the physical substructure. Dynamical substructuring system (DSS) scheme, which requires more complicated control design, determines the control input to minimize control error obtained by outputs of numerical and physical substructures. This study has found that, in shaking experiments, the stability of the hybrid simulation scheme is very sensitive to a pure time delay. It is also found that DSS scheme can provide much higher stability margin against the pure time delay than the hybrid simulation scheme. The effort to rather complicated controller design of DSS scheme will be rewarded at actual control practices.
Parametrically Excited Nonlinear Two-Degree-of-Freedom Electromechanical Systems
Authors: Zaghari Bahareh , Kniffka Till , Levett Cameron , Rustighi Emiliano
Published: July 2019

This paper presents a nonlinear parametrically excited cantilever beam with electromagnets. A parametrically excited two-degree-of-freedom (2-DOF) system with linear time-varying stiffness, nonlinear cubic stiffness, nonlinear cubic parametric stiffness and nonlinear damping is considered. In previous studies the stability and bifurcation of the nonlinear parametrically excited 2-DOF were investigated through analytical, semi-analytical and numerical methods. Unlike previous studies, in this contribution the system’s response amplitude and phase at parametric resonance and parametric combination resonance are demonstrated experimentally and some novel results are discussed. Experimental and analytical amplitude-frequency plots are presented to show the stable solutions. Solutions for the system response are presented for specific values of parametric excitation frequency and the energy transfer between modes of vibrations is observed. The results presented in this paper prove that the bifurcation point and hence the bandwidth of the parametric resonance can be predicted correctly with the proposed analytical method. The proposed nonlinear parametrically excited 2-DOF can be used to design Micro ElectroMechanical Systems (MEMS) actuators and sensors. Validating the experimental results with the theory can improve the efficiency of these electrical systems.
Introduction of line contact in frequency-based substructuring process using measured rotational degrees of freedom
Authors: Čepon Gregor , Drozg Armin , Boltežar Miha
Published: July 2019

The theory of frequency-based substructuring enables us to combine the dynamical behavior of multiple subsystems into the common response of the whole system. Subsystem’s properties can be numerically or experimentally obtained in the form of frequency response functions. Response models are then coupled together taking into account a connectivity conditions. However, when one is dealing with a statically indeterminate multi-point connections such as flanges connected over several bolts, it is difficult to properly define a model in the numerical environment. In order to obtain real contact conditions a few methods like virtual point transformation and multi-point connection were proposed in recent years. Since an indirect approach of obtaining rotational motion struggle to accurately define local dynamic characteristics i.e. antiresonances, it also rely on assumption of rigid interface. In this paper we are introducing an alternative approach, where all six degrees of freedom are experimentally obtained with aim to directly address local joint flexibility in the substructuring process. This procedure represent an alternative to the method that removes the effects of a flexible fixture, however here it is done directly by measuring contact dynamic without the need of additional fixture block. Rotational responses are directly obtained using rotational accelerometer that enable us to gather all six degrees of freedom in each experimental point. Consequently, contact can be fully defined with less measurement points where several of them with only translational responses are required in other methods for reconstruction of rotational motion.
Vehicle-track-soil interaction and train-induced ground vibration – Theory and measurements in Germany, Switzerland and France
Authors: Auersch L
Published: July 2019

Three measurement campaigns of train-induced ground vibrations are evaluated for the vehicle-track-soil interaction. Ground vibrations, track vibrations and vehicle vibrations have been measured for train passages and impulse excitation and compared with theoretical results. The soil and the track-soil system are calculated by wavenumber integrals. The influence of the vehicle is introduced by a substructure method. By comparing theory and measurement the different components of excitation force and ground vibration can be analysed, the quasi-static excitation, track-alignment errors, the out-of-roundness of wheels, the wheel and rail roughness, and moreover, scattered axle impulses and ineffective high-frequency parts of the wheelset accelerations and forces.
Effect of contact area with fixture on dynamic behaviour of joint interface in ultrasonic welding of thermoplastics
Authors: Kuratani F , Miyano S , Yoshida T , Washio S
Published: July 2019

Ultrasonic welding is one of the most common methods for joining thermoplastics. The two plastic parts to be joined are placed on the fixture before high frequency mechanical vibration is applied to the parts through an ultrasonic horn. This generates heat at the joint area and locally melts thermoplastics. The parts are welded together. In this paper, we investigate the effect of the contact area between the lower part and the fixture on the dynamic behaviour of the joint interface, which affects heat generation. The displacements and elastic strains of the interface are predicted using finite element dynamic contact analysis and compared for different contact areas. The results show that the dynamic behaviour of the interface depends on the dynamic characteristics of the two parts. When both natural frequencies are close to the horn vibration frequency, the displacements and strains are small. Conversely, when the lower part has no natural frequency near the horn vibration frequency, the displacements and strains are large. The contact area significantly affects the dynamic behaviour of the interface. This is because its dynamic behaviour depends on the natural frequencies of the parts to be joined while the natural frequency of the lower part is easily improved by the contact area.
Research and development of acid corrosion inhibitor for single stage process of isoprene synthesis
Authors: Burganov R.T. , Shepelin V.A. , Gilmullina A.R. , Kovrizhnyh E.A. , Khasanova D.I. , Dikaryova U.M.
Published: July 2019

New acid corrosion inhibitor OPC-2000 has been developed for a single stage process of isoprene synthesis. Gravimetric method has found high effectiveness of the inhibitor in conditions of dilute ortho-phosphoric and sulfuric acids towards alloys Incoloy 825 and 12X18H10T being applied within the range of 10-16 g/dm3. According to electrochemical investigation, OPC- 2000 is an anodic class inhibitor. It has high dispersing properties (no sediment formation in reactors), the fact being confirmed in the course of PJSC Nizhnekamsneftekhim’s industrial trials while a single stage of isoprene synthesis.
Method of Aluminum Salts Extraction from Wastewater Using Desalination Technology: Syr Darya River Case Study1
Authors: Junussova Lyazzat Ryskhanovna , Chicherin Stanislav Viktorovich
Published: July 2019

The Aral Sea Region is characterized by being a very demanding consumer of industrial wastewater treatment. We studied the effects of various pretreatment methods on aluminum production. This method can be used as an alternative one in industrial wastewater treatment. The aim of multi-year study is to explore a nanofiltration as a one of the most attractive technologies for this application since nanofiltration membranes can retain ions and small organic molecules from an aqueous solution. But it is also very challenging due to the presence of salts and operating problems such as fouling, salt deposition, etc. Result becomes available thank to experimental set-up based on an ion exchange and a reverse osmosis. Results are also verified by evaluation tests and field applications showing their usage and wastewater conversion efficiency. The technological scheme includes combined water treatment plant using desalination technology and additional block functioning for an aluminum production and a temporary storage. Aluminum is to be produced of the Syr Darya river rich of it with the help of cutting-edge technology of oxide film removal and cartridge packing. This work evaluates the use of aluminum accumulated in the reaction unit by means of aluminum powder plus water module to reduce the pollutant contents of industrial wastewater quickly and effectively. The invention makes it possible to reduce the cost of aluminum by 3-4 times. Energy consumption of the desalination process was also discussed. Extracted aluminum is a superior material for industry. The high activity of aluminum to water is prohibited by a thin layer of aluminum oxide on its surface. The water treatment system with a combined phase purification and desalination may contribute up to 50 per cent to meeting the reduction of energy consumption for end product (aluminum).
Water purification from phenol on materials from subtropical crops’ wastes
Authors: Somin Vladimir , Komarova Larisa
Published: July 2019

The article considers the possibility of using materials on the bases of wastes of subtropical crops for water purification from phenol. The modification of banana peel, orange peel and pineapple peel by chemical and thermal methods was carried out. The static and dynamic capacity of obtained sorbents was determined; their ability to regeneration was estimated.
Year-round fish breeding on energy saving principles of industrial aquaculture
Authors: Garlov P.E. , Rybalova N.B. , Shinkarevich E.D. , Nechayeva T.A. , Temirova S.U. , Bugrimov B.S.
Published: July 2019

With a view to year-round valuable fish farming a control system terming their breeding and growth, protected by USSR inventor’s certificates and Russian inventor’s patents, was developed. The management principle is fish contents in “critical” salinity along with the simultaneous thresholds “signal” factors (temperature and light) and subsequently obtaining offspring and juveniles in complex of optimal ecological conditions.

For the implementation of the proposed industrial biotechnology and year-round fish farming a new installation of water recycling system (WRS) hatcheries and farms was developed by means of the underground conditioning of fish cultivation medium. Their essence is that fish farm water supply systems are additionally provided by underground, or in a half in ground large volume tank-sump tanks. Such WRC, being isolated from climate conditions, allow to conserve and use natural seasonal water resources and first consensually resolve earlier alternative volume-dependent energy problem (requiring lower volumes of water) and water purification (requiring its increasing) in septic tank-sump tanks. The basic principle of their operation is filling one tank-conditioner by “cold” water and the other by “warm” at the appropriate seasons and by additional water supply fish farm systems water circulation. Techno-economic calculation shows, that with the increasing volume of such water air conditioning heat transfer will be proportionally reduced, but productivity increases and reduces its system specific cost while maximizing reliability.
The development and energy efficiency of LNG in Russia
Authors: Ketoeva N.L. , Orlova Y.S.
Published: July 2019

The state data of the market structure and the development of liquefied natural gas (LNG). The major LNG projects being implemented or planned for implementation on the territory of Russia. Characterized prospects for the development of LNG production in Russia up to 2023. The main problem of LNG projects implementation. Marked instruments contributing to the development and the energy efficiency industry improvement.
Substantiation of the need for long-term planning of hydropower development as an element of energy management in Russia
Authors: Novikova O.V. , Kamenik L.L. , Furtatova A.S. , Denisova P.I. , Livshits S.A.
Published: July 2019

At the present stage of social development, the need to assess the prospects for the rational use of the hydropower resource potential in Russia had been manifested as an independent unresolved problem, which urgently requires the study of its essence, regularities, the specifics of manifestation and the mechanisms for its solution. This testifies to the urgency of the conducted research, whose purpose was to conduct analytical work on the evaluation of current priorities and directions in energy development and the study of new approaches to long-term planning in hydropower development. The solution of the task was accomplished on the basis of a systematic approach to forecasting the resource potential, energy, hydropower and economic development of the country, which is the novelty of the work. The conclusion is the increasing role of hydropower. The article is interest to scientists, government employees, professors, students and all those who are interested in sustainable development of the society.
Perfection of the methodology for developing industrial secondary energy generation systems
Authors: Plotnikova L V , Giniyatov R R , Sitnikov S Y , Fedorov M A , Zaripova R S
Published: July 2019

The algorithm for selecting an energy-efficient secondary energy generation system for large industrial enterprises is proposed. The updated coefficients of the system use of heat and exergy and the Sankey diagram are given. The software implementation of thermodynamic calculations of complex industrial schemes with secondary energy generation devices is presented.
Production of biogas from poultry waste using the biomass of plants from Amaranthaceae family
Authors: Karaeva J.V. , Kamalov R.F. , Kadiyrov A.I.
Published: July 2019

The experimental results of kinetics of biogas formation for the organic waste utilization are presented for the case where combinations of technological and microbiological methods are used to enhance the process (ultrasonic pre-treatment and coenzyme with a new plant supplement). The plants from Amaranthaceae family are used as plant supplements. The influence of Amaranthus hypochondriacus and Amaranthus retroflexus L. on the process of methanogenesis for poultry wastes is analyzed. Based on the experimental results it is obtained that the maximum daily yield of biogas from substrate including the Amaranthus retroflexus L. and Amaranthus hypochondriacus are 310 ml and 252 ml respectively. For example the maximum daily yield of biogas from substrate without any plant supplements was 211 ml (“pure substrate”). Thus the biogas output rate from poultry waste using the biomass of plants from Amaranthaceae family is 47% higher than standard case. The total biogas yield using the plants supplement from Amaranthaceae family is higher than standard case.
On low-frequency unsteady phenomena caused by cavitation in hydroturbines
Authors: Kuibin P A , Zakharov A V
Published: July 2019

When hydroturbines operate at part load or over load, intense pressure and vibration pulsations may occur. One of the instability mechanisms is due to the presence of a cavitation bubble (or cloud) behind the runner. Chen et al. [1] the phenomenon is modeled using the concept of cavitation compliance. They demonstrated the destabilizing effect of the diffuser and swirl. In the present work, the influence of two factors on the coefficients of the characteristic equation, whose solution yields natural frequencies and oscillation increments, is revealed. They are the vorticity distribution and the size of the cavitation cavity behind the runner. It is shown that the effect of swirl on stability is much smaller than that described in [1] and rapidly decreases with the growth of cavitation bubble size.
Experience and inspiration in shaping urban cultural space: Cases of London, Paris, New York and Tokyo
Authors: Wei Wei , Shuaiquan Zhang , Bing Wang
Published: July 2019

Urban culture place is the concentrated embodiment of urban vitality, which has increasingly become the focus of urban construction. It’s of great practical significance for improving city quality and realizing sustainable development to study the shaping methods of urban cultural space. In this paper, four international cities’ status quos of cultural space development are chosen for case studies. The spatial types are classified into three levels: “integration-functionality-serviceability”. The shaping methods include strategic guidance, shaping diverse cultural spaces, forming characteristic cultural industries, and promoting the equalization of cultural facilities. Based on the above, it is proposed that in the important period of urban transformation and development in China, we can learn from international experience in terms of creating urban image, formulating cultural development planning, developing creative industries, and improving urban cultural atmosphere and vitality, and achieving the goal of diverse cultural space, abundant cultural activities, accessible cultural facilities and prosperous cultural establishment.
Monitoring and Analysis of Ultra-wide and Deep Foundation Pit Deformation in Complex Environment
Authors: jia Liu
Published: July 2019

Taking the deep foundation pit of Foshan Zongde Service Center as the research background, the on-site monitoring data of the deep horizontal displacement, supporting axial force, horizontal displacement of the wall and the settlement of the column pile during the excavation process of the deep foundation pit are analyzed. The results show that during the excavation process of the deep foundation pit, the envelope structure is basically not affected by the excavation of the soil within the pit after the excavation surface is less than 10m; the reasonable arrangement of the support position can effectively reduce the displacement amplitude of the wall body; encryption monitors the change of the axial force of the adjacent support, and prestresses the upper support to improve the safety of the foundation pit; the greater the depth of the foundation pit is, the uplift of the column under the combined action of the pile side frictional resistance and the support of ballast and self-weight - sedimentation rate. The larger the amount of change is, the more the ballast is applied to the support when the support is poured, the amount of rebound of the column is reduced, and the continuous excavation of the earth can be effectively reduced to reduce the peak of the column uplift and prevent the column from being unstable due to the large difference between the settlement and the uplift. Endanger the safety of the support system in the pit.