bluuebunny/crossref_metadata_2025 huggingface dataset:
Improving the energy efficiency of the pipeline system by ensuring its linear flow characteristic
Authors: Dymochkin Denis , Kilina Mariya , Grishenko Vyacheslav , Kharchenko Alexandr
Published: July 2021

Recently, SMART positioners have been widely used to control the on-off and control valves. These devices allow you to set an arbitrary user dependence of the valve travel on the control signal. This makes it possible to provide a linear throughput for the entire piping system. This allows the use of smaller type control valves while maintaining the control range. Accordingly, the energy consumption for controlling the shutoff element is reduced; the value of the reinforcement energy efficiency indicator is improved. In that work analytically calculates a user dependency that takes into account the value of pipeline throughput and allows to obtain a linear throughput of the pipeline system in the entire range of control signal change.
Synthesis of non-linear controller to energy efficiency for damped-elastic-jointed inverted pendulum
Authors: Nguyen C.X. , Le Th.Tr. , Tran Ph.C. , Lukianov A.D. , Truong Kh.D. , Pham T.D.
Published: July 2021

In the paper we propose a synthetic way of the nonlinear controller for the damped-elastic-jointed inverted pendulum. The controller is designed based on the synergistic approach, the global variables are built on the asymptotically stable manifolds and the fast acting objective function is energy efficient. The effectiveness of the export method is proven through simulation results and compared with other methods.
Improving the efficiency of autonomous wind turbines
Authors: Pchelnikova-Grotova Olga
Published: July 2021

The article discusses the development of a mathematical model of a combined wind turbine of a multi-modular wind power plant, which makes it possible to control the operation of wind turbines with the greatest efficiency, changing the operating modes of the installation depending on the wind flow entering the inlet. The implementation of the developed model at a multi-module wind station allowed us to obtain a maximum wind utilization factor of 0.35-0.47 at any wind speeds, as well as at low wind speeds to increase the initial torque of the wind wheel by 4 times in comparison with typical power plants.
Methods for improving the energy efficiency of the installation with a discrete secondary part
Authors: Kuimov Denis , Minkin Maxim
Published: July 2021

Hydrodynamic cavitation, created by the intensive movement of the secondary discrete part in an electromechanical device, is the most important energy effect in the processing of petroleum products. The presented work contains and summarizes the results of the study of the main parameters of cavitation processing, including the geometric parameters of the elements of the secondary discrete part, the speed and trajectory of the secondary discrete part, as well as the parameters of the processed raw materials. It is established that to achieve an intense cavitation field, it is necessary, depending on the parameters of the processed raw material (its rheological properties), to maintain the optimal temperature and ensure the speed of movement of the elements of the secondary discrete part.
Determining the mode of operation of the system section, taking into account the current topology and predictive analysis of the active-adaptive network of 6-10 kV
Authors: Yurov Alexander , Voronov Alexander , Lukonin Alexey
Published: July 2021

Technical solutions aimed at improving the reliability of power supply to consumers of the 6-10 kV network are proposed, a block diagram of a fundamentally new device for diagnosing and protecting cells of 6-10 kV power cable lines with a single algorithm of operation is shown, which allows simultaneously performing current protection of the controlled feeder and monitoring with a predictive assessment (residual resource) of the state of the cable insulation material. A possible scheme of interaction of elements of an active-adaptive power unit of 6-10 kV is shown on the example of a cell of a 6-10 kV cable line. he device will allow you to control leakage currents in distribution networks, taking into account the remaining cable life, reduce insulation losses during power transmission and increase the energy efficiency of the controlled network by reducing power interruptions to the consumer. The quantitative values of the device will be determined after its introduction into trial operation.
Application of satellite images for assessing winter wheat and spring barley crops on the average NDVI value
Authors: Pavlovskaya Ninel , Rodimtsev Sergei , Borodin Dmitrii , Vershinin Stepan , Gagarina Irina , Mikhaylova Yulia
Published: July 2021

The article presents data on the state of the surveyed fields of winter wheat and spring barley of the experimental farm “Integration” of the Orel state agrarian university using satellite images. The dynamic values of the Normalized Difference Vegetation Index (NDVI) were obtained by analyzing satellite images of the experimental plots, starting with early flowering phase of agricultural crops. The corresponding maps were prepared based on these data; the data visualization and access to them were implemented on the GeoMixer base of the WebGIS platform. Digital processing of the information was provided with the digital processing program of the Earth remote sensing ScanEx Image Processor V.5.0. The boundaries of the experimental plots were determined by vector pathes (polygons) built into the digital environment of the composite control system (CСS) of the agricultural organization “AgroNetwork Technologies” (ANT). This software is the basis of the digital platform for the experimental farm of the university. The NDVI values for spring barley in the control zone are very low and amount to about 0.5 in the middle of the season, which predicts the yield to be twice lower than the optimal one.
Development of minced fish semi-finished products enriched with polyunsaturated fatty acids
Authors: Popova Nadezhda , Shchetilina Irina , Pisklyukova Yuliya , Agaeva Nadezhda
Published: July 2021

One of the priority areas of resource-saving technologies in the food industry and public catering is the development of functional products based on a balanced combination of protein-containing raw materials of animal origin and plant raw materials. In the work, for the production of chopped fish semi-finished products - cutlets (CFSFPc), based on the analysis of chemical composition data, the main raw materials and sources of polyunsaturated fatty acids (PFA) were selected; in accordance with the principles of creating functional products, the quantitative composition of the recipe components is optimized; the functional and technological properties (FTP) of model minced meat have been studied; an assessment of the organoleptic characteristics of finished products was carried out.
Idiopathische inflammatorische Myopathien: Aktuelles zu Diagnose und Klassifikation
Authors: Tomaras Stylianos , Kekow Jörn , Feist Eugen
Published: July 2021

Auf dem Sektor der Kollagenosen ist der wissenschaftliche Fortschritt bei der Myositis in den letzten 15–20 Jahren bemerkenswert. Durch kontinuierliche Forschung und intensive Vernetzung der Myositis-Experten ist es gelungen, neue Untergruppen zu identifizieren und somit für die Prognose wichtige Organmanifestationen rechtzeitig zu erkennen. Vor dem Hintergrund dieser Neuerungen verfolgt diese Übersichtsarbeit sowohl das Ziel, möglichst alle Facetten der Erkrankung zu präsentieren, als auch die moderne Einteilung der idiopathischen inflammatorischen Myopathien zu erläutern. Außerdem werden die neuen Klassifikationskriterien vorgestellt, die die Kriterien von Bohan und Peter aus dem Jahr 1975 abgelöst haben. Im Artikel werden ihre Stärken und Schwächen sowie ihr Optimierungspotenzial diskutiert.
Heilsame „Schockwelle“
Authors: Hayashi Kenji
Published: July 2021

Sotaiho entstammt als heilgymnastische Methode der traditionellen japanischen Medizin und dient dem Abbau von Gelenkfehlstellungen und Muskelverspannungen sowie der Schulung in Achtsamkeit und Körpergefühl. Durch Fehlbelastungen wie einseitige Bewegungen bei Rechts- oder Linkshändern oder falsches Aufheben verlagert sich der Körperschwerpunkt als Bewegungszentrum von der Körpermitte weg, mit Beckenschiefstand und Wirbelsäulenverkrümmungen als Folge. Für die Technik führt der Patient eine Bewegung (zum Beispiel des Unterschenkels) mit einer Ausatmung von der schmerzenden zur angenehmen Seite aus, woraufhin der Therapeut gegendrückt und der Patient nach 5 sec plötzlich entlastet – was wie eine heilsame „Schockwelle“ in den Körper hineinwirkt.
Glaucoma Diagnostic Testing: The Influence of Optic Disc Size
Authors: Scheuble Pascal , Petrak Michael , Brinkmann Christian Karl
Published: July 2021

Background There are various imaging techniques for the assessment of the optic disc in glaucoma patients. However, anatomically conspicuous, large or small optic discs can be quite
challenging for an examiner.

Objective The Bruchʼs membrane opening (BMO) by spectral domain optical coherence tomography (SD-OCT) is a modern approach for the quantitative measures of retinal nerve fibre layer
(RNFL). The study focuses on comparison analysis of the BMO method and the widely used Heidelberg retina tomograph (HRT) method – in terms of detection of glaucoma for different optic disc
sizes.

Methods 216 Patients examinations during glaucoma consultation hours. Macro- (Ma) and micro-optic discs (Mi) detected by HRT are analysed via BMO analysis in SD-OCT. Correlation
between BMO area and optic disc measured by HRT has been investigated and examined in terms of severity of visual field defect (MD [dB]).

Results The results of study show that for micro and macro-optic discs there is a modest correlation between the size of optic disc measured by BMO and the size of optic disc
measured by HRT by applying funduscopic examination (correlation rate r = 0,53; Mi: n = 111, Ma: n = 105). For micro-optic discs with a very small BMO area (< 1.5 mm2), there
is a significant tendency (linear trend test p < 0.05) towards deeper visual field defects (MD < − 5 dB).

Conclusion The BMO parameter of SD-OCT allows an assessment of glaucoma for a large range of optic disc sizes. BMO area and optic disc size measured by HRT are not correlated. Micro
optic discs with a small BMO area lead to a higher risk of deep visual field defects.
Effect of Periocular Triamcinolone Acetonide on Prevention of Postsurgical Intraretinal Cystoid Changes after Vitrectomy with Membrane Peeling
Authors: Leisser Christoph , Burgmüller Wilhelm , Findl Oliver
Published: July 2021

Background Newly developed intraretinal cystoid changes after vitrectomy with membrane peeling for removal of epiretinal membranes have the potential to lead to worse postsurgical results compared to patients without. The aim of the present study was to evaluate the feasibility of additional periocular application of triamcinolone acetonide as a routine adjunct at the end of vitrectomy with membrane peeling, and to compare the presence of postsurgical intraretinal cystoid changes in the first 3 months after surgery among patients with idiopathic epiretinal membranes to a historical group of patients that did not receive triamcinolone acetonide.

Patients and Methods The medical records of 41 eyes of 41 patients that underwent 23 G or 25 G pars plana vitrectomy with membrane peeling for removal of epiretinal membranes and additional periocular triamcinolone acetonide application at the end of surgery were retrospectively reviewed. Optical coherence tomography findings during routine follow-ups at 3 – 5 days, 1 month, and 3 months and visual acuity at 3 months after surgery were evaluated and compared to preoperative findings. Furthermore, postsurgical intraocular pressure was assessed.

Results Periocular triamcinolone acetonide at the end of surgery was well tolerated among all patients. In total, 10% of patients had an increased intraocular pressure at least at one follow-up. Best-corrected visual acuity improved in 91% of patients with idiopathic epiretinal membranes with a mean improvement of + 3 ± 2 lines (Snellen) and was comparable to a historic group of patients (p = 0.307). Early transient macular edema could not be detected in any of the patients, while there were cases with this pathology in the historic group of patients, but neither occurrence of newly developed intraretinal cystoid changes nor macular thickness at 3 months after surgery were significantly different between patients with and without triamcinolone acetonide (p = 0.385 and p = 0.879).

Conclusions Periocularly applied triamcinolone acetonide at the end of vitrectomy with membrane peeling was well tolerated and showed prevention of early transient macular edema but did not prevent the development of new postoperative intraretinal cystoid changes.
Freie Bahn für die Leitbahnen
Authors: Seybold-Kellner Birgit
Published: July 2021

Bei der funktionellen Leitbahndiagnostik werden anhand von (schmerzhaften) Bewegungseinschränkungen Blockaden in den durch die Bewegung gedehnten Leitbahnabschnitten identifiziert. Mithilfe eines Tastbefunds lassen sich therapeutisch wichtige Akupunkturpunkte im Verlauf blockierter Leitbahnen identifizieren; in der Regel sind sie druckdolent. Die Therapie der identifizierten Druckpunkte erfolgt klassisch mithilfe von Dauernadeln, doch auch eine Akupressur der zu behandelnden Punkte ist möglich.
Vertebroplasty Increases the Incidence Of New Vertebral Compression Fractures Compared To Conservative Management
Authors: Othman Maram , Alshaalan Meshal , Khawaji Abdulrahman , Benkuddah Rawan , Khalil Hala , Alismail Khalid , Althobaity Waleed , Alreshoodi Saleh
Published: July 2021

Background Vertebral osteoporotic fractures are a major cause of morbidity and disability among the elderly population.

This study sought to compare the incidence of new vertebral fractures in patients treated by vertebroplasty with that of those managed conservatively, while also assessing the potential risk factors contributing to the occurrence of these fractures.

Materials and Methods The details of a total of 121 eligible subjects with radiologically proven osteoporotic vertebral fractures were retrieved from our archive between January 2010 and September 2019 and divided, based on the treatment method, into percutaneous vertebroplasty (PVP) (n = 60) and nonsurgical treatment (n = 61). The included subjects’ clinical data, demographic profiles, and imaging findings on plain radiography, CT, and MRI scans performed at baseline and within 24 months following treatment were reviewed and documented.

Results The difference in the incidence of new fractures was statistically significant (p = 0.001), with rates of 70% (n = 32) in the vertebroplasty group and 30% (n = 14) in the conservatively treated cases reported at a median follow-up time point of approximately 4 months. The presence of liver disease (p = 0.037), a history of transplantation (p = 0.003), the use of steroids (p = 0.023), a low-bone mineral density (BMD) score (p = 0.023), and a higher number of fractures on baseline imaging (p = 0.013) were associated with a greater risk of subsequent vertebral fractures.

Conclusions The incidence of acute fractures after PVP is higher than that among patients treated conservatively. Decision-making regarding the adoption of this intervention should take into consideration the risk factors leading to a greater risk of subsequent vertebral fractures, such as a higher number of fractures at baseline imaging, low-BMD score, patient comorbidities, and steroid use.
Calibration of coherence imaging spectroscopy using spectral line sources
Authors: Ueda Kenji , Nishiura Masaki , Kenmochi Naoki , Yoshida Zensho , Nakamura Kaori
Published: July 2021

Coherence imaging spectroscopy (CIS) measures the two-dimensional profiles of both ion temperature and ion velocity in plasmas. The interferometric technique is realized by a certain relation between the phase and the wavelength of light emerging from a birefringent crystal. The calibration for the CIS system requires monochromatic and tunable light sources near the He II line (468.6 nm) or C III line (465 nm) where the CIS measures. In this research, the CIS system has been upgraded by implementing an electron multiplier CCD and a CIS cell. A monochromator validates the linearity of the phase relation on the wavelength near the He II line. As an in situ calibration at the Ring Trap 1 plasma device, two spectral lines of Ti and Zn lamps obtain the accurate dispersion function of phase. It is found that a simple method with two spectral lines is reliable and sufficient for the calibration.
Multiscale modeling of genome organization with maximum entropy optimization
Authors: Lin Xingcheng , Qi Yifeng , Latham Andrew P. , Zhang Bin
Published: July 2021

Three-dimensional (3D) organization of the human genome plays an essential role in all DNA-templated processes, including gene transcription, gene regulation, and DNA replication. Computational modeling can be an effective way of building high-resolution genome structures and improving our understanding of these molecular processes. However, it faces significant challenges as the human genome consists of over 6 × 109 base pairs, a system size that exceeds the capacity of traditional modeling approaches. In this perspective, we review the progress that has been made in modeling the human genome. Coarse-grained models parameterized to reproduce experimental data via the maximum entropy optimization algorithm serve as effective means to study genome organization at various length scales. They have provided insight into the principles of whole-genome organization and enabled de novo predictions of chromosome structures from epigenetic modifications. Applications of these models at a near-atomistic resolution further revealed physicochemical interactions that drive the phase separation of disordered proteins and dictate chromatin stability in situ. We conclude with an outlook on the opportunities and challenges in studying chromosome dynamics.
Stochastic effects of waves on currents in the ocean mixed layer
Authors: Holm Darryl D. , Hu Ruiao
Published: July 2021

This paper introduces an energy-preserving stochastic model for studying wave effects on currents in the ocean mixing layer. The model is called stochastic forcing by Lie transport (SFLT). The SFLT model is derived here from a stochastic constrained variational principle, so it has a Kelvin circulation theorem. The examples of SFLT given here treat 3D Euler fluid flow, rotating shallow water dynamics, and the Euler–Boussinesq equations. In each example, one sees the effect of stochastic Stokes drift and material entrainment in the generation of fluid circulation. We also present an Eulerian averaged SFLT model based on decomposing the Eulerian solutions of the energy-conserving SFLT model into sums of their expectations and fluctuations.
Characterization of radical-enhanced atomic layer deposition process based on microwave surface wave generated plasma
Authors: Tvarog Drahoslav , Olejníček Jiří , Kratochvíl Jiří , Kšírová Petra , Poruba Aleš , Hubička Zdeněk , Čada Martin
Published: July 2021

A plasma-assisted atomic layer deposition system employing a microwave surfatron plasma was developed and characterized by spatially resolved Langmuir probe diagnostics and optical emission spectroscopy. The deposition process was applied on TiO2 thin films prepared on Si wafers. The surfatron is equipped with a small ring electrode serving as a source of weak radio frequency plasma helping with fast and reliable ignition of the discharge in molecular gas. Results evaluated in the pure argon plasma proved that the plasma potential and the plasma density are homogeneous in the radial direction, while a rapid decrease was observed in the axial direction. Adding up to 30% of nitrogen into the gas mixture led to less homogeneous plasma parameters in the radial direction together with the increase of the electron effective temperature. Optical emission spectra revealed many Ar I lines of neutral atoms with only a few Ar II ions’ lines. The gradual addition of nitrogen causes a systematic decrease in the Ar I line intensity. We expect that excited nitrogen molecules are produced by the inelastic collisions with electrons and by the collisional quenching of metastable Ar(4s) states. On the other hand, oxygen atom and ion lines are detected when oxygen was mixed with argon. Deposited TiO2 thin films are characterized by the anatase phase when the substrate temperature is 250 °C. The anatase phase is observed even for the substrate temperature of 200 °C; however, the microwave power delivered into the surfatrons must be lower in comparison with the prior case.
A miniaturized low frequency (LF) magnetoelectric receiving antenna with an integrated DC magnetic bias
Authors: Niu Yunping , Ren Hao
Published: July 2021

Due to the applications in meteorological broadcasts, radio navigation, and underwater communications, low-frequency (LF) receiving antennas have been actively studied. However, because the frequency range of LF antenna is 30 to 300 kHz, its electromagnetic wavelength is 1 to 10 km, which makes LF electromagnetic antennas difficult to be implemented in miniaturized or portable devices. This article presents a miniaturized LF magnetoelectric (ME) receiving antenna with an integrated DC magnetic bias. The antenna is based on the magnetoelectric effect and operates by resonance at its mechanical resonant frequency. Thus, compared with traditional LF wire antennas, the dimension of ME antenna is reduced significantly. Compared with prior art of ME antennas which do not have DC magnetic bias, higher performance can be achieved by integrating the miniaturized DC magnetic bias. Magnetostrictive TbDyFe2 (Terfenol-D) and piezoelectric lead zirconate titanate thin films are bonded together to form the 38 × 12 × 5.8 mm3 ME receiving antenna. Four 10 × 10 × 10 mm3 Rb magnets are implemented to provide an optimal DC bias for the antenna. A maximum operation distance of 2.5 m is demonstrated with the DC magnetic field bias, 2.27 times of the maximum operation distance of the antenna without DC magnet field bias. The efficiency, gain, and quality factor of the ME receiving antenna are also characterized. The miniaturized LF ME antenna could have potential applications in portable electronics, Internet of things, and underwater communications.
From a eutectic mixture to a deep eutectic system via anion selection: Glutaric acid + tetraethylammonium halides
Authors: van den Bruinhorst Adriaan , Kollau Laura J. B. M. , Vis Mark , Hendrix Marco M. R. M. , Meuldijk Jan , Tuinier Remco , Esteves A. Catarina C.
Published: July 2021

In pursuit of understanding structure–property relationships for the melting point depression of binary eutectic mixtures, the influence of the anion on the solid–liquid (S–L) phase behavior was explored for mixtures of glutaric acid + tetraethylammonium chloride, bromide, and iodide. A detailed experimental evaluation of the S–L phase behavior revealed that the eutectic point is shifted toward lower temperatures and higher salt contents upon decreasing the ionic radius. The salt fusion properties were experimentally inaccessible owing to thermal decomposition. The data were inter- and extrapolated using various models for the Gibbs energy of mixing fitted to the glutaric-acid rich side only, which allowed for the assessment of the eutectic point. Fitting the experimental data to a two-parameter Redlich–Kister expansion with Flory entropy, the eutectic depth could be related to the ionic radius of the anion. The anion type, and in particular its size, can therefore be viewed as an important design parameter for the liquid window of other acid and salt-based deep eutectic solvents/systems.
Exceptional degeneracies in traveling wave tubes with dispersive slow-wave structure including space-charge effect
Authors: Rouhi Kasra , Marosi Robert , Mealy Tarek , Abdelshafy Ahmed F. , Figotin Alexander , Capolino Filippo
Published: July 2021

The interaction between a linear electron beam and a guided electromagnetic wave is studied in the context of exceptional points of degeneracy (EPD) supported by such an interactive system, focusing on a linear beam traveling wave tube (TWT) with a realistic helix waveguide slow-wave structure (SWS). The interaction is formulated by an analytical model that is a generalization of the Pierce model, assuming a one-dimensional electron flow along a dispersive single-mode guiding SWS and taking into account space-charge effects. The augmented model using phase velocity and characteristic impedance obtained via full-wave simulations is validated by calculating gain vs frequency and comparing it with that from more complex electron beam simulators. This comparison also shows the accuracy of our new model compared with respect to the nondispersive Pierce model. EPDs are then investigated using the augmented model, observing the coalescence of complex-valued wavenumbers and the system's eigenvectors. The point in the complex dispersion diagram at which the TWT-system starts/ceases to exhibit a convection instability, i.e., a mode starts/ceases to grow exponentially along the TWT, is the EPD. We also demonstrate the EPD existence by showing that the Puiseux fractional power series expansion well approximates the bifurcation of the dispersion diagram at the EPD. This latter concept also explains the “exceptional” sensitivity of the TWT-system to changes in the beam's electron velocity when operating near an EPD.
High switching uniformity and 50 fJ/bit energy consumption achieved in amorphous silicon-based memristive device with an AgInSbTe buffer layer
Authors: Ren Yanyun , Fu Xiaojing , Yang Zhi , Sun Ruoyao , Lin Ya , Zhao Xiaoning , Wang Zhongqiang , Xu Haiyang , Liu Yichun
Published: July 2021

In this work, we demonstrated the high switching uniformity and 50 fJ/bit energy consumption in an amorphous silicon-based resistive switching (RS) device by inserting the AgInSbTe (AIST) layer between the silicon insulating layer and Ag top electrodes. The improved RS performance is attributed to the introduction of an Ag ion reservoir layer, which helps to suppress conducting filament overgrowth. After insertion of the AIST layer, the cumulative probability of low/high resistance states decreased from 176.8%/46.2% to 3.1%/11.9%, respectively. The advantages of promoting Ag dissolution enable the realization of fast switching speed (<50 ns) and low set voltage (∼70 mV), which gives our device low energy consumption (∼50 fJ/bit). Moreover, the multi-step of set/reset analytical model of our dual-layer RS device was developed based on the formation and dissolution of the Ag-ion-based conductive filaments. Our work presents an effective method for obtaining high-performance Si-based memory for practical applications.
Boussinesq hierarchy and bi-Hamiltonian geometry
Authors: Ortenzi Giovanni , Pedroni Marco
Published: July 2021

We study the Boussinesq hierarchy in the geometric context of the theory of bi-Hamiltonian manifolds. First, we recall how its bi-Hamiltonian structure can be obtained by means of a process called bi-Hamiltonian reduction, choosing a specific symplectic leaf S of one of the two Poisson structures. Then, we introduce the notion of a bi-Hamiltonian S-hierarchy, that is, a bi-Hamiltonian hierarchy that is defined only at the points of the symplectic leaf S, and we show that the Boussinesq hierarchy can be interpreted as the reduction of a bi-Hamiltonian S-hierarchy.
Dynamics of antiproton plasma in a time-dependent harmonic trap
Authors: F. Soares L. G. , Haas F.
Published: July 2021

An antiproton plasma confined in a quasi-1D device is described in terms of a self-consistent fluid formulation using a variational approach. Unlike previous treatments, the use of the time-dependent variational method allows to retain the thermal and Coulomb effects. A certain Ansatz is proposed for the number density and fluid velocity fields, which reduces the problem essentially to ordinary nonlinear differential equations. In adiabatic cooling, the frequency of the trap potential is slowly decreased. An adiabatic equation of state is assumed for closure. The numerical simulation of the nonlinear dynamics is performed for realistic parameters.
Solidification and dynamic wetting: A unified modeling framework
Authors: Shikhmurzaev Yulii D.
Published: July 2021

A conceptual and mathematical framework for the singularity-free modeling of non-equilibrium solidification/melting and non-isothermal dynamic wetting is developed where both processes are embedded into a broader class of physical phenomena as particular cases. This allows one to consider problems describing fluid flows with phase transitions and dynamic wetting occurring independently or interactively in a regular conceptually consistent way without ad hoc assumptions. The simplest model formulated on the basis of this approach explains, at this stage qualitatively, the arrest of the moving contact line observed experimentally in the impact and spreading of a molten drop on a cold substrate. The classical Stefan problem and the model of isothermal dynamic wetting as an interface formation process are recovered as limiting cases.
Binding of noble gas atoms by superhalogens
Authors: Fang Hong , Deepika Deepika , Jena Puru
Published: July 2021

Because of their closed shells, noble gas (Ng) atoms (Ng = Ne, Ar, Kr, and Xe) seldom take part in chemical reactions, yet finding such mechanisms not only is of scientific interest but also has practical significance. Following a recent work by Mayer et al. [Proc. Natl. Acad. Sci. U. S. A. 116, 8167–8172 (2019)] on the room temperature binding of Ar to a superelectrophilic boron site embedded in a negative ion complex, B12(CN)11−, we have systematically studied the effect of cluster size and terminal ligands on the interaction of Ng by focusing on B12X11(Ng) (X = H, CN, and BO) and B12X10(Ng)2 (X = CN and BO) whose stabilities are governed by the Wade–Mingos rule and on C5BX5(Ng) (X = H, F, and CN) and C4B2(CN)4(Ng)2 whose stabilities are governed by the Huckel’s aromaticity rule. Our conclusion, based on density functional theory, is that both the cluster size and the terminal ligands matter—the interaction between the cluster and the Ng atoms becomes stronger with increasing cluster size and the electron affinity of the terminal ligands. Our studies also led to a counter-intuitive finding—removing multiple terminal ligands can enable electrophilic centers to bind multiple Ng atoms simultaneously without compromising their binding strength.
Exploration of interlacing and avoided crossings in a manifold of potential energy curves by a unitary group adapted state specific multi-reference perturbation theory (UGA-SSMRPT)
Authors: Chakravarti Dibyajyoti , Hazra Koustav , Kayal Riya , Sasmal Sudip , Mukherjee Debashis
Published: July 2021

The Unitary Group Adapted State-Specific Multi-Reference Perturbation Theory (UGA-SSMRPT2) developed by Mukherjee et al. [J. Comput. Chem. 36, 670 (2015)] has successfully realized the goal of studying bond dissociation in a numerically stable, spin-preserving, and size-consistent manner. We explore and analyze here the efficacy of the UGA-SSMRPT2 theory in the description of the avoided crossings and interlacings between a manifold of potential energy curves for states belonging to the same space-spin symmetry. Three different aspects of UGA-SSMRPT2 have been studied: (a) We introduce and develop the most rigorous version of UGA-SSMRPT2 that emerges from the rigorous version of UGA-SSMRCC utilizing a linearly independent virtual manifold; we call this the “projection” version of UGA-SSMRPT2 (UGA-SSMRPT2 scheme P). We compare and contrast this approach with our earlier formulation that used extra sufficiency conditions via amplitude equations (UGA-SSMRPT2 scheme A). (b) We present the results for a variety of electronic states of a set of molecules, which display the striking accuracy of both the two versions of UGA-SSMRPT2 with respect to three different situations involving weakly avoided crossings, moderate/strongly avoided crossings, and interlacing in a manifold of potential energy curves (PECs) of the same symmetry. Accuracy of our results has been benchmarked against IC-MRCISD + Q. (c) For weakly avoided crossing between states displaying differently charged sectors around the crossing region, the insufficient inclusion of state-specific orbital relaxation and the absence of dynamic correlation induced by orbital relaxation in the first order wavefunction for a second order perturbative theory lead to an artifact of double crossing between the pair of PECs.
Toward quantitative electronic structure in small gold nanoclusters
Authors: Fagan Jonathan W. , Weerawardene K. L. Dimuthu M. , Cirri Anthony , Aikens Christine M. , Johnson Christopher J.
Published: July 2021

Ligand-protected gold nanoclusters (AuNCs) feature a dense but finite electronic structure that can be rationalized using qualitative descriptions such as the well-known superatomic model and predicted using quantum chemical calculations. However, the lack of well-resolved experimental probes of a AuNC electronic structure has made the task of evaluating the accuracy of electronic structure descriptions challenging. We compare electronic absorption spectra computed using time-dependent density functional theory to recently collected high resolution experimental spectra of Au9(PPh3)83+ and Au8(PPh3)72+ AuNCs with strikingly similar features. After applying a simple scaling correction, the computed spectrum of Au8(PPh3)72+ yields a suitable match, allowing us to assign low-energy metal–metal transitions in the experimental spectrum. No similar match is obtained after following the same procedure for two previously reported isomers for Au9(PPh3)83+, suggesting either a deficiency in the calculations or the presence of an additional isomer. Instead, we propose assignments for Au9(PPh3)83+ based off of similarities Au8(PPh3)72+. We further model these clusters using a simple particle-in-a-box analysis for an asymmetrical ellipsoidal superatomic core, which allows us to reproduce the same transitions and extract an effective core size and shape that agrees well with that expected from crystal structures. This suggests that the superatomic model, which is typically employed to explain the qualitative features of nanocluster electronic structures, remains valid even for small AuNCs with highly aspherical cores.
Flexural bending resonance of acoustically levitated glycerol droplet
Authors: Fang Zilong , Huang Xiao , Taslim Mohammad E. , Wan Kai-tak
Published: July 2021

A levitated glycerol droplet supported by an acoustic standing wave, when subject to modulated field at frequency on the order of 150 Hz, behaves as a solid plate and exhibits flexural bending resonance rather than the conventional equatorial star-shape oscillations. Three oscillation modes are observed: seesaw, saddleback, and monkey saddle with the increasing energy levels. The finite element analysis generates droplet shapes consistent with the experimental observation and yields apparent plate flexural rigidity in terms of surface tension and aspect ratio of plate thickness to diameter. High viscosity leads to the plate-like behavior of the droplet.
Viscoplastic toroidal drop in compressional Stokes flow
Authors: Banerjee Abhishek , Lavrenteva Olga M. , Smagin Irina , Nir Avinoam
Published: July 2021

We report the dynamics of a viscoplastic (Bingham) torus suspended in an unbounded Newtonian medium. In this study, the immiscible ambient fluid is subjected to an axisymmetric compressional (biaxial-extensional) flow. Numerical simulations applying the boundary integral formulation to the Stokes flow are performed for the torus drop having initially a circular cross section. The quasi-stationary dynamic simulation reveals that depending on the initial conditions and the capillary number (Ca), the Bingham number (Bn), and the viscosity ratio (λ), three different scenarios of the drop evolution are obtained for a range of viscosity ratio and Bingham number: collapsing toward the axis of symmetry, expanding infinitely, and having a stationary toroidal shape.
On combining the beam path of similar wavelength lasers for dual-laser Thomson scattering
Authors: McCormack O. , Giudicotti L. , Fassina A. , Pasqualotto R.
Published: July 2021

A novel method for the path combination of two lasers with very similar wavelengths has been implemented to enable the evaluation of a dual-laser calibration Thomson scattering (TS) technique. The first experimental test of this TS technique has been performed in a RFX-mod plasma device, where, due to experimental constraints, the combination of a Nd:YAG (λ = 1064 nm) and a Nd:YLF (λ = 1053 nm) laser system was the only viable choice available. The method requires that the beam path of both lasers be combined into a single path with the same polarization. This presents a unique challenge due to the small difference between the two laser wavelengths. In this paper, we describe two methods for beam combination: first via a prism, eventually dismissed as unpractical, and second via a polarizing beam splitter in reverse with a dual-wavelength waveplate. We detail the optical setup, waveplate design, and successful implementation of this second method.
Benchmarking a lattice-Boltzmann solver for reactive flows: Is the method worth the effort for combustion?
Authors: Boivin P. , Tayyab M. , Zhao S.
Published: July 2021

This Letter reports a validation of a lattice-Boltzmann approach following the Taylor–Green Vortex benchmark presented at the 19th International Congress on Numerical Combustion and recently reported by Abdelsamie et al. [“The Taylor–Green vortex as a benchmark for high-fidelity combustion simulations using low-Mach solvers,” Comput. Fluids 223, 104935 (2021)]. The lattice-Boltzmann approach, despite having a time step bound by an acoustic Courant–Friedrichs–Lewy condition, provides results faster than the low-Mach solvers which performed to the benchmark. Such a feat is made possible by the fully explicit nature of the method and indicates very high potential for practical applications.
Exploring for the Future geomechanics: breaking down barriers to exploration
Authors: Bailey Adam H. E. , Jarrett Amber J. M. , Wang Liuqi , Dewhurst David N. , Esteban Lionel , Kager Shane , Monmusson Ludwig , Carr Lidena K. , Henson Paul A.
Published: July 2021

Exploring for the Future (EFTF) is an Australian Government initiative focused on gathering new data and information about potential mineral, energy and groundwater resources across Australia. The energy component of EFTF, initially focussed on northern Australia, aims to improve our understanding of the petroleum potential of frontier Australian basins. Building an understanding of geomechanical rock properties is key to understanding both conventional and unconventional petroleum systems as well as carbon storage and sedimentary geothermal systems. Under EFTF, Geoscience Australia has undertaken geomechanical work including stress modelling, shale brittleness studies and the acquisition of new rock property data through extensive testing on samples from the Paleo- to Mesoproterozoic South Nicholson region of Queensland and the Northern Territory, and the Paleozoic Kidson Sub-basin of Western Australia. Work in these regions demonstrates regional stress orientations in broad agreement with previously modelled, continent-scale stress orientations and stress magnitudes that vary through the basin with depth and by lithology. Rock testing highlights potentially brittle shales and demonstrates variable rock properties in line with lithology. These analyses are summarised herein. Providing baseline geomechanical data in frontier basins is essential as legacy data coverage can often be inadequate for making investment decisions, particularly where unconventional plays are a primary exploration target. As EFTF increases in scope, Geoscience Australia anticipates expanding these studies to encompass further underexplored regions throughout Australia, lowering the barrier to entry and encouraging greenfield exploration.
Case study for CO2 removal using Fluor Solvent for offshore natural gas treatment
Authors: Kritzinger Niel , Ravikumar Ravi , Singhal Sunil , Singh Kakul , Choudhury Soumya Jyoti
Published: July 2021

The need to remove CO2 from natural gas has become more important as producers are required to develop offshore reserves with high CO2 content. Conventional amine treating processes require extensive heating and cooling and constant monitoring to maintain plant performance. Amine systems are also prone to solvent degradation and portions of the plant require construction from stainless steel material to prevent corrosion. An ideal offshore treating process should have a small footprint, be easy to operate and maintain and be able to handle CO2 feed content fluctuations. This paper introduces the Fluor Solvent® propylene carbonate-based process technology. The Fluor Solvent system absorbs CO2 from a feed gas using propylene carbonate and releases CO2 by pressure reduction of the rich solvent without the need for heat-based regeneration. The system is particularly suitable for offshore applications due to its simplicity and flexibility. Fluor Solvent is non-toxic, relatively low cost and readily available from several solvent manufacturers. Since Fluor Solvent is anhydrous, both the treated gas and CO2 product streams are suitable for pipeline distribution. In addition, the entire plant can be constructed from carbon steel. This case study compares the use of Fluor Solvent to a traditional activated methyldiethanolamine (MDEA)-based system for removing CO2 from an offshore gas. The comparison includes rough order of magnitude (ROM) delta capital and operating costs for feed gases with varying CO2 concentrations.
How do you trap a shy wombat? Trialling new trap designs for northern hairy-nosed wombats (
Authors: Molyneux Jenny , Harper Dave , Horsup Alan
Published: July 2021

The low trap success (2–4%) of northern hairy-nosed wombats (Lasiorhinus krefftii) has proven a considerable limiting factor to their conservation and management. This project aimed to utilise expert knowledge and experience to redesign current traps and deployment to improve trap success, reduce by-catch and required resources, and improve safety for field staff and captured fauna. A trial of several trap variations and deployment strategies was conducted at Epping Forest National Park (Scientific). Results indicated new trap design and deployment strategies contributed to improving outcomes against all the aims. Most notably, an increased trap success of 10.5% was detected, significantly improving capabilities to achieve conservation and management outcomes.
Cysteine cross-linking in native membranes establishes the transmembrane architecture of Ire1
Authors: Väth Kristina , Mattes Carsten , Reinhard John , Covino Roberto , Stumpf Heike , Hummer Gerhard , Ernst Robert
Published: July 2021

The ER is a key organelle of membrane biogenesis and crucial for the folding of both membrane and secretory proteins. Sensors of the unfolded protein response (UPR) monitor the unfolded protein load in the ER and convey effector functions for maintaining ER homeostasis. Aberrant compositions of the ER membrane, referred to as lipid bilayer stress, are equally potent activators of the UPR. How the distinct signals from lipid bilayer stress and unfolded proteins are processed by the conserved UPR transducer Ire1 remains unknown. Here, we have generated a functional, cysteine-less variant of Ire1 and performed systematic cysteine cross-linking experiments in native membranes to establish its transmembrane architecture in signaling-active clusters. We show that the transmembrane helices of two neighboring Ire1 molecules adopt an X-shaped configuration independent of the primary cause for ER stress. This suggests that different forms of stress converge in a common, signaling-active transmembrane architecture of Ire1.
NMR Evidence of Antiferromagnetic Spin Fluctuations in Nd0.85Sr0.15NiO2
Authors: Cui Yi , Li Cong , Li Qing , Zhu Xiyu , Hu Ze , Yang Yi-feng , Zhang Jinshan , Yu Rong , Wen Hai-Hu , Yu Weiqiang
Published: July 2021

Despite the recent discovery of superconductivity in Nd1–x
Sr
x
NiO2 thin films, the absence of superconductivity and antiferromagnetism in their bulk materials remains a puzzle. Here we report the 1H NMR measurements on powdered Nd0.85Sr0.15NiO2 samples by taking advantage of the enriched proton concentration after hydrogen annealing. We find a large full width at half maximum of the spectrum, which keeps increasing with decreasing the temperature T and exhibits an upturn behavior at low temperatures. The spin-lattice relaxation rate

1

T
1

−
1

is strongly enhanced when lowering the temperature, developing a broad peak at about 40 K, then decreases following a spin-wave-like behavior

1

T
1

−
1

∝

T
2

at lower temperatures. These results evidence a short-range glassy antiferromagnetic ordering of magnetic moments below 40 K and dominant antiferromagnetic fluctuations extending to much higher temperatures. Our findings reveal the strong electron correlations in bulk Nd0.85Sr0.15NiO2, and shed light on the mechanism of superconductivity observed in films of nickelates.
Resolving the Bethe–Salpeter Kernel
Authors: Qin Si-Xue , Roberts Craig D.
Published: July 2021

A novel method for constructing a kernel for the meson bound-state problem is described. It produces a closed form that is symmetry-consistent (discrete and continuous) with the gap equation defined by any admissible gluon-quark vertex, Γ. Applicable even when the diagrammatic content of Γ is unknown, the scheme can foster new synergies between continuum and lattice approaches to strong interactions. The framework is illustrated by showing that the presence of a dressed-quark anomalous magnetic moment in Γ, an emergent feature of strong interactions, can remedy many defects of widely used meson bound-state kernels, including the mass splittings between vector and axial-vector mesons and the level ordering of pseudoscalar and vector meson radial excitations.
Effects of dispersal and spatial heterogeneity on nonlocal logistic equations
Authors: Sun Jian-Wen
Published: July 2021

In the present paper, we are interested in the nonlocal dispersal logistic equations in heterogeneous environment. This leads to study the spectrum theory and asymptotic behavior of nonlocal dispersal problems. We establish the existence and uniqueness of positive stationary solutions. By employing continuous lemma and nonlocal estimates, we obtain the limiting behavior of positive solutions when the dispersal rate is small or large. We also analyze the effect of spatial heterogeneity on the long time behavior of evolution equations.
Sine-Gordon on a wormhole
Authors: Bizoń Piotr , Dunajski Maciej , Kahl Michał , Kowalczyk Michał
Published: July 2021

In an attempt to understand the soliton resolution conjecture, we consider the sine-Gordon equation on a spherically symmetric wormhole spacetime. We show that within each topological sector (indexed by a positive integer degreen) there exists a unique linearly stable soliton, which we call then-kink. We give numerical evidence that then-kink is a global attractor in the evolution of any smooth, finite energy solutions of degreen. When the radius of the wormhole throatais large enough, the convergence to then-kink is shown to be governed by internal modes that slowly decay due to the resonant transfer of energy to radiation. We compute the exact asymptotics of this relaxation process for the one-kink using the Soffer–Weinstein weakly nonlinear perturbation theory.