bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasma thermal-chemical instability of low-temperature dimethyl ether oxidation in a nanosecond-pulsed dielectric barrier discharge
Authors: Zhong Hongtao , Yang Xin , Mao Xingqian , Shneider Mikhail N , Adamovich Igor V , Ju Yiguang 
Published: October 2022

AbstractPlasma stability in reactive mixtures is critical for various applications from plasma-assisted combustion to gas conversion. To generate stable and uniform plasmas and control the transition towards filamentation, the underlying physics and chemistry need a further look. This work investigates the plasma thermal-chemical instability triggered by dimethyl-ether (DME) low-temperature oxidation in a repetitive nanosecond pulsed dielectric barrier discharge. First, a plasma-combustion kinetic mechanism of DME/air is developed and validated using temperature and ignition delay time measurements in quasi-uniform plasmas. Then the multi-stage dynamics of thermal-chemical instability is experimentally explored: the DME/air discharge was initially uniform, then contracted to filaments, and finally became uniform again before ignition. By performing chemistry modeling and analyzing the local thermal balance, it is found that such nonlinear development of the thermal-chemical instability is controlled by the competition between plasma-enhanced low-temperature heat release and the increasing thermal diffusion at higher temperature. Further thermal-chemical mode analysis identifies the chemical origin of this instability as DME low-temperature chemistry. This work connects experiment measurements with theoretical analysis of plasma thermal-chemical instability and sheds light on future chemical control of the plasma uniformity.
Electrical transport properties in Ge hyperdoped with Te
Authors: Caudevilla D , Algaidy S , Pérez-Zenteno F , Duarte-Cano S , García-Hernansanz R , Olea J , San Andrés E , del Prado A , Barrio R , Torres I , García-Hemme E , Pastor D 
Published: October 2022

Abstract
In this work we have successfully hyperdoped germanium with tellurium with a concentration peak of 1021 cm−3. The resulting hyperdoped layers show good crystallinity and sub-bandgap absorption at room temperature which makes the material a good candidate for a new era of complementary metal-oxide-semiconductor-compatible short-wavelength-infrared photodetectors. We obtained absorption coefficients α higher than

4.1
×

10

3

cm−1 at least up to 3 µm. In this study we report the temperature-dependency electrical properties of the hyperdoped layer measured in van der Pauw configuration. The electrical behaviour of this hyperdoped material can be explained with an electrical bilayer coupling/decoupling model and the values for the isolated hyperdoped layer are a resistivity of

4.25
×

10

−
3

Ω
⋅

cm with an electron-mobility around −100 cm2 V−1 s−1.
Near-infrared broadband polarization beam splitter with an Au nanocube array
Authors: Zhou Yangyang , Zhou Xingping , Zhuang Rui , Liu Aiping , Wang Qin 
Published: October 2022

Abstract
A near-infrared broadband polarization beam splitter (PBS) is proposed and numerically simulated, which is realized by a directional coupler assisted with an Au nanocube array. The fundamental transverse electric (TE) mode can be coupled to the output of the upper waveguide by exciting the surface plasmon polaritons (SPPs), while the fundamental transverse magnetic (TM) mode is output directly from the lower waveguide. The length of the coupling region of the PBS is only 1 μm. It has a working bandwidth of 210 nm in the range of 1420 ∼ 1630 nm, covering three bands: S-, C- and L-bands. The simulation shows that the extinction ratio of TE and TM polarization is 20.31 dB and 14.15 dB, respectively.
Study of the backscattering of electron beams with energies typical of radiotherapy
Authors: Koohi Behzad , Khabaz Rahim 
Published: October 2022

Abstract
During radiotherapy, the dose of electrons backscattered into the tissue should be taken into account. According to the available data on the electron backscattering phenomenon, the backscatter rate varies depending on the specific radiotherapy delivery configuration. Using the Monte Carlo code MCNPX, the backscattering distribution and their saturation values for electron beams with energies between 4 MeV and 25 MeV (the energies used in electron therapy) of various materials such as polystyrene, aluminum, copper and lead were obtained. Data obtained with MCNPX show that the probability of electron backscattering is strongly dependent on the effective atomic number and the energy of the electron. For low energy electrons, the backscattering probability depends less on the energy and is mainly a function of the effective atomic number of the backscatter material. The saturation values of the backscattering are distributed as a linear function of the effective atomic number of the scattering material for all investigated energies. Therefore, it is recommended that equipment and accessories used with patients in electron radiotherapy LINAC be materials with low atomic numbers (Z), and that a layer of low Z material be used over a higher Z material for protection.
The energy budget of cosmological first-order phase transitions beyond the bag equation of state
Authors: Wang Shao-Jiang , Yuwen Zi-Yan 
Published: October 2022

AbstractThe stochastic gravitational-wave backgrounds (SGWBs) from the cosmological first-order phase transitions (FOPTs) serve as a promising probe for the new physics beyond the standard model of particle physics. When most of the bubble walls collide with each other long after they had reached the terminal wall velocity, the dominated contribution to the SGWBs comes from the sound waves characterized by the efficiency factor of inserting the released vacuum energy into the bulk fluid motions. However, the previous works of estimating this efficiency factor have only considered the simplified case of the constant sound velocities in both symmetric and broken phases, either for the bag model with equal sound velocities orν-model with different sound velocities in the symmetric and broken phases, which is unrealistic from a viewpoint of particle physics. In this paper, we propose to solve the fluid EoM with an iteration method when taking into account the sound-velocity variation across the bubble wall for a general and realistic equation of state (EoS) beyond the simple bag model andν-model. We have found a suppression effect for the efficiency factor of bulk fluid motions, though such a suppression effect could be negligible for the strong FOPT, in which case the previous estimation from a bag EoS on the efficiency factor of bulk fluid motions still works as a good approximation.
Global 21-cm brightness temperature in viscous dark energy models
Authors: Halder Ashadul , Pandey Shashank Shekhar , Majumdar A.S. 
Published: October 2022

AbstractWe investigate the global 21-cm brightness temperature in the context of viscous dark energy (VDE) models. The bulk viscosity of dark energy perturbs the Hubble evolution of the Universe which could cool baryons faster, and hence, alter the 21-cm brightness temperature. An additional amount of entropy is also produced as an outcome of the viscous flow. We study the combined contribution of Hawking radiation from primordial black holes, decay and annihilation of particle dark matter and baryon-dark matter scattering in the backdrop of VDE models towards modification of the 21-cm temperature. We obtain bounds on the VDE model parameters which can account for the observational excess of the EDGES experiment (-500+200-500mK at redshift 14 <z< 20) due to the interplay of the above effects. Moreover, our analysis yields modified constraints on the dark matter mass and scattering cross-section compared to the case of the ΛCDM model.
Far-field scattering control of wave based on all-dielectric blazed encoding metagrating
Authors: He Xuejun , Lin Feng , Huang Wenkang , Li Chenxia , Jing Xufeng 
Published: October 2022

Abstract
Coding metagrating metasurfaces can realize flexible and effective control of polarization, amplitude, and phase of electromagnetic waves. The coded metagrating builds a bridge between the physical unit structure and the digital coding, and can realize the digital coding calculation processing of the physical device. We propose several all dielectric encoded metagrating sequences, and the detailed analysis of their far-field scattering properties is given. Based on the principle of digital coding addition, we add two coding metagrating sequences to obtain a new coding sequence. This new coding sequence results in an additive integration of the functions of the original two coding sequences. This method provides an idea for the realization of multifunctional devices.
3
S
1–3
D
1 coupled channel Λ
c

N interactions: chiral effective field theory versus lattice QCD
Authors: Song Jing , Xiao Yang , Liu Zhi-Wei , Li Kai-Wen , Geng Li-Sheng 
Published: October 2022

Abstract
We study the lattice QCD Λ
c

N phase shifts for the 3
S
1–3
D
1 coupled channel using both the leading order covariant chiral effective theory and the next-to-leading order non-relativistic chiral effective field theory (ChEFT). We show that although it is possible to describe simultaneously the 3
S
1 and 3
D
1 phase shifts and the inelasticity η
1, the fitted energy range is quite small, only up to E
c.m. = 5 MeV. This raises concerns regarding the consistency between leading/next-to-leading order ChEFT and the lattice QCD simulations.
Cyclic controlled remote state preparation in the three-dimensional system
Authors: Ma Peng-Cheng , Chen Gui-Bin , Li Xiao-Wei , Zhan You-Bang 
Published: October 2022

Abstract
In this work, we propose a novel protocol for cyclic controlled remote state preparation (CCRSP) with single-qutrit equatorial states. In this protocol, three distant parties, Alleyn, Breden and Carden, are not only senders but also receivers. Alleyn wants to remotely prepare a single-qutrit equatorial state at Breden’s site, while at the same time, Breden (Carden) wishes to help Carden (Alleyn) remotely preparing another single-qutrit equatorial state. It is shown that, only if the three senders and the controller collaborate with each other, the CCRSP can be completed. To present this protocol more clearly, only maximally entangled channel is considered.
Finger movement and coactivation predicted from intracranial brain activity using extended block-term tensor regression
Authors: Faes A , Hulle M M Van 
Published: October 2022

Abstract

Objective. We introduce extended Block-Term Tensor Regression (eBTTR), a novel regression method designed to account for the multilinear nature of human intracranial finger movement recordings. Approach. The proposed method relies on recursive Tucker decomposition combined with automatic component extraction. Main results. eBTTR outperforms state-of-the-art regression approaches, including multilinear and deep learning ones, in accurately predicting finger trajectories as well as unintentional finger coactivations. Significance. eBTTR rivals state-of-the-art approaches while being less computationally expensive which is an advantage when intracranial electrodes are implanted acutely, as part of the patient’s presurgical workup, limiting time for decoder development and testing.
Micro solder bump detection of flip chip using improved decision tree model based on SAM image
Authors: Zhou J. , Yang W. , Chen T. , Lu X. , He Z. 
Published: October 2022

Abstract
The increasing packaging density of flip chips brings great
challenges for micro defect detection. It is necessary to develop an
efficient and automatic inspection system for electronic industrial
application. In this paper, the scanning acoustic microscopy (SAM)
technology and the optimized classifier were investigated for the
automatic detection of solder joint defects of flip
chips. Ultrasonic images of 1902 solder bumps from 6 chip samples
were obtained using a SAM equipment. The decision tree model was
improved by introducing the granularity decision entropy. The
feature vectors were extracted from the images of solder bumps, and
then used for classification. The results show that the decision
tree model correctly detected 1812 solder bumps with the accuracy of
95.3%. It is verified that the ultrasonic defect detection system
based on the improve decision tree model has high accuracy for micro
defect inspection, which has potential and promising application in
the electronic packaging industry.
Taking stock of and advancing knowledge on interaction archetypes at the nexus between land, biodiversity, food and climate
Authors: Sietz Diana , Neudert Regina 
Published: October 2022

Abstract
Global challenges related to land, biodiversity, food and climate interact in diverse ways depending on local conditions and the broader context in which they are embedded. This diversity challenges learning and integrated decision-making to sustainably transform the nexus, that is to say the interactions between these land-based challenges. Providing aggregated insights, archetype analysis has revealed recurrent patterns within the multitude of interactions, i.e. interaction archetypes that are essential to enhance the understanding of nexus relations. This paper synthesises the state of knowledge on interaction or nexus archetypes related to land, biodiversity, food and climate based on a systematic literature review. It focusses on the coverage of thematic aspects, regional distribution, social dimensions and methodologies. The results show that consideration of comprehensive land–biodiversity–food–climate interactions is rare. Furthermore, there are pronounced regional knowledge gaps, social dimensions are inadequately captured, and methodological shortcomings are evident. To enhance the investigation of interaction archetypes, we have framed a future research agenda providing directions to fully capture interactions across space and time, better use the potential of scenario archetypes and up-scale transformative actions. These advances will constructively contribute insights that help to achieve the ambitious objective to sustainably transform the nexus between land, biodiversity, food and climate.
The SAGEX review on scattering amplitudes Chapter 11: Soft Theorems and Celestial Amplitudes
Authors: McLoughlin Tristan , Puhm Andrea , Raclariu Ana-Maria 
Published: October 2022

Abstract
The soft limits of scattering amplitudes have been extensively studied due to their essential role in the computation of physical observables in collider physics. The universal factorisation that occurs in these kinematic limits has been shown to be related to conservation laws associated with asymptotic, or large, gauge symmetries. This connection has led to a deeper understanding of the symmetries of gauge and gravitational theories and to a reformulation of scattering amplitudes in a basis of boost eigenstates which makes manifest the two-dimensional global conformal symmetry of the celestial sphere. The recast, or celestial, amplitudes possess many of the properties of conformal field theory (CFT) correlation functions which has suggested a path towards a holographic description of asymptotically flat spacetimes. In this review we consider these interconnected developments in our understanding of soft theorems, asymptotic symmetries and CFT with a focus on the structure and symmetries of the celestial amplitudes and their holographic interpretation.
Investigation of Water Hammer Overpressure in the Hydraulic Passages of Hydropower Plants Equipped with Francis Turbines
Authors: Lupa S-I , Gagnon M , Muntean S , Abdul-Nour G 
Published: October 2022

Abstract
Water hammer shortens hydraulic passage lifespan and may cause sudden failure. The primary goal is to use a hierarchical approach to assess the main parameters associated with water hammer. This will help investigate their influence and assist in decision making. Analytical calculation results and a numerical model are compared against experimental data. Our investigations examine water hammer overpressure loading induced by transient regimes. We used data from experimental campaigns carried out within the Hydro-Québec fleet that cover different types of hydraulic turbines and hydraulic passage configurations as experimental dataset. Guide vane closing rate was the main parameter controlled during the overpressure experiments and a general trend was identified for overpressure. This empirical trend is compared to model estimates in order to validate the hypothesis taken into account for calculations. An in-depth understanding of the water hammer phenomenon helps to select the appropriate theoretical model and recommend the optimal operating parameters to extend lifetime and to avoid catastrophic failures. Our study case suggests that available experimental data can be used along with gradually increasing analysis complexity to identify the optimal methodology for a given configuration.
Application of hydro-abrasive erosion model from IEC 62364:2019 standard in Francis turbines
Authors: Acharya N , Gautam S , Chitrakar S , Trivedi C , Dahlhaug O G 
Published: October 2022

Abstract
Hydro-abrasive erosion in hydraulic turbines is critical and one of the prominent issue due to its association with maintenance costs and production losses in the hydropower plant. IEC 62364:2019* standard guide focuses mainly on hydroelectric powerplant equipment and provides the standard on particle abrasion rates on several combinations like operating conditions, component materials properties, water quality among many factors. With the consideration of different critical parameters, a theoretical model of abrasion rate on hydraulic turbines is proposed by IEC 62364:2019. Present study is conducted to elucidate the several terms used in the theoretical model of abrasion rate for Francis turbine as per the guidelines. The work has taken account into run-off river (RoR) hydropower plant consisting of Francis runner operating in sediment laden rivers in the Himalayan area. Theoretical expected erosion depth for runner inlet, runner outlet, guide vanes facing plates and labyrinth seals is calculated. Characteristic velocities of runner (Wrun) and guide vanes (Wgv) were estimated to be 32.26 m/s and 35.05 m/s respectively. Particle load was calculated based upon the sampling data available from the site. Measurement data from field observation during overhauling was used for comparison with the data calculated from empirical relation. For 229 hours operation of turbine, observed abrasion depth varies from 8.1 mm in guide vanes to 1.5 mm in labyrinth ring corresponding to calculated values of 7.53 mm and 1.89 mm for same components. Results shows good correlation among calculated values from IEC and measured values from the site. An optimized solution can thus be devised based on the evaluation of hydro-abrasive erosion along with energy production and maintenance expenses.
*IEC 62364:2019. Hydraulic machines - Guidelines for dealing with hydro-abrasive erosion in Kaplan, Francis, and Pelton turbines. Edition 2.0 (March 2019) International Electrotechnical Commission, Geneva, Switzerland [1]
Automated hydraulic design procedure for a Francis turbine spiral casing
Authors: Lazarevikj M , Markov Z 
Published: October 2022

Abstract
The spiral casing of a Francis turbine distributes the water from the penstock to the stay and guide vanes circumferentially and uniformly, which is important for achieving the required flow conditions at the runner entrance. Moreover, the spiral casing is supposed to provide the required inlet velocity in front of the stay vanes and create minimal hydraulic losses. The dimensions and shape of the spiral casing depend on the hydraulic and energy parameters of the turbine. A calculation methodology for a Francis spiral casing hydraulic design is presented in this paper. The methodology developed is based on the main condition to achieve a uniform water flow rate into the stay vanes system and the wicket gate over the entire perimeter. The free vortex flow theory is implemented in this research, where the design is based on the law of constant velocity moment. The parametric definition of the spiral casing makes the geometries generated for certain input combinations suitable for numerical analysis using commercially available Computational Fluid Dynamics (CFD) software. The calculation procedure can be used for any set of energy and geometry turbine parameters, such as water discharge, angle of streamline departing from the spiral casing, and stay ring diameter and height. The automated approach integrating MATLAB and ANSYS Workbench capabilities is presented as a spiral casing design tool. The product is a design solution proposed on basis of the turbine parameters. The spiral casing geometry generation is followed by a CFD analysis. Considering input parameters of different existing Francis turbines, the spiral casing is redesigned accordingly. One of the obtained spiral casings geometry is numerically tested. The results show that the uniform discharge distribution is achieved. The automation of the design procedure allows further optimization based on chosen input parameters.
Design and development of non-recirculating type erosion test setup for hydraulic turbines
Authors: Kapali A , Neopane H P , Chitrakar S , Shrestha O 
Published: October 2022

Abstract

Slurry erosion phenomena are inevitable and commonly occurring processes in all types of hydro turbines and components that are exposed to sediment particles. The design of these components and the choice of the materials to resist erosion require laboratory testing using various erosion testing apparatus. These test apparatuses are designed specifically to meet the particular study requirements and to simulate the actual flow conditions in turbines. However, the design of these test apparatus must be flexible and versatile to assess erosion resistance under different combinations of operating conditions. The existing test rigs mostly comprise of rotary type with re-circulation of the slurry. This study proposes a new type of test setup that describes the sediment particles injection method into the system as well as immediate rejection of those particles striking the test specimen. The components of test rig and the test methodology are described. An accelerated tests have been performed on Cross-flow turbine to verify the suitability of the rig for erosion testing in laboratory environment. The design principle of this setup is to eliminate the limitations of the existing test rigs such as slurry ageing problem, use of acceleration tube to maintain the particle velocity and constant operating parameters (discharge velocity and pressure head). The non-recirculation of the slurry is maintained by the use of hydro cyclone as the particle separation device, which is found to have an efficiency of 97%. This test facility provides flexibility in the performance testing of miniature model of different types of hydro turbines with limited adjustments.