bluuebunny/crossref_metadata_2025 huggingface dataset:
Accurate storm surge prediction using a multi-recurrent neural network structure
Authors: Feng Xiao-Chen , Xu Hang
Published: March 2023

This paper considers storm surge prediction using a neural network and considering multiple physical characteristics. Based on the factors that influence storm surges and historical observation data, we divide the input to the neural network into time features extracted from the prediction target and the auxiliary features that affect storm surges, and construct a feature gate within multiple recurrent neural network (RNN) cells. Historical hurricane data are used to assess the effectiveness and accuracy of the proposed model. Comparative analysis against a long short-term memory (LSTM) storm surge prediction model is conducted to verify the prediction performance of the proposed method. The comparison results show that the multi-RNN model is superior to the LSTM model in terms of four evaluation metrics and for all lead times. In particular, the multi-RNN model accurately predicts the maximum storm surge water level, and the prediction results are more consistent with the rise and fall of the water. A comparison of the storm surge forecasts using inputs from different time intervals under different evaluation indices confirms the generalization and stability of our proposed model. The experiments of storm surge prediction at six stations further confirm the wide applicability of the model.
A divergence-free constrained magnetic field interpolation method for scattered data
Authors: Yang M. , del-Castillo-Negrete D. , Zhang G. , Beidler M. T.
Published: March 2023

An interpolation method to evaluate magnetic fields, given its unstructured and scattered magnetic data, is presented. The method is based on the reconstruction of the global magnetic field using a superposition of orthogonal functions. The coefficients of the expansion are obtained by minimizing a cost function defined as the L2 norm of the difference between the ground truth and the reconstructed magnetic field evaluated on the training data. The divergence-free condition is incorporated as a constraint in the cost function, allowing the method to achieve arbitrarily small errors in the magnetic field divergence. An exponential decay of the approximation error is observed and compared with the less favorable algebraic decay of local splines. Compared to local methods involving computationally expensive search algorithms, the proposed method exhibits a significant reduction of the computational complexity of the field evaluation, while maintaining a small error in the divergence even in the presence of magnetic islands and stochasticity. Applications to the computation of Poincaré sections using data obtained from numerical solutions of the magnetohydrodynamic equations in toroidal geometry are presented and compared with local methods currently in use.
Innate dynamics and identity crisis of a metal surface unveiled by machine learning of atomic environments
Authors: Cioni Matteo , Polino Daniela , Rapetti Daniele , Pesce Luca , Delle Piane Massimo , Pavan Giovanni M.
Published: March 2023

Metals are traditionally considered hard matter. However, it is well known that their atomic lattices may become dynamic and undergo reconfigurations even well below the melting temperature. The innate atomic dynamics of metals is directly related to their bulk and surface properties. Understanding their complex structural dynamics is, thus, important for many applications but is not easy. Here, we report deep-potential molecular dynamics simulations allowing to resolve at an atomic resolution the complex dynamics of various types of copper (Cu) surfaces, used as an example, near the Hüttig (∼1/3 of melting) temperature. The development of deep neural network potential trained on density functional theory calculations provides a dynamically accurate force field that we use to simulate large atomistic models of different Cu surface types. A combination of high-dimensional structural descriptors and unsupervized machine learning allows identifying and tracking all the atomic environments (AEs) emerging in the surfaces at finite temperatures. We can directly observe how AEs that are non-native in a specific (ideal) surface, but that are, instead, typical of other surface types, continuously emerge/disappear in that surface in relevant regimes in dynamic equilibrium with the native ones. Our analyses allow estimating the lifetime of all the AEs populating these Cu surfaces and to reconstruct their dynamic interconversions networks. This reveals the elusive identity of these metal surfaces, which preserve their identity only in part and in part transform into something else under relevant conditions. This also proposes a concept of “statistical identity” for metal surfaces, which is key to understanding their behaviors and properties.
A near spurious-free 6 GHz LLSAW resonator with large electromechanical coupling on X-cut LiNbO3/SiC bilayer substrate
Authors: Liu Peisen , Fu Sulei , Su Rongxuan , Xu Huiping , Xiao Boyuan , Song Cheng , Zeng Fei , Pan Feng
Published: March 2023

The fast development of the fifth-generation (5G) wireless systems and substantial growth of data usage have imposed stringent requirements for high-frequency and wideband radio frequency devices. Here, it is reported on a longitudinal leaky surface acoustic wave (LLSAW) mode acoustic resonator with a large electromechanical coupling factor (kt2), high operating frequency, and efficient spurious suppression. Through systematical finite element method simulations, available design spaces such as supporting substrate, propagation angle, and lithium niobate (LN) thickness have been fully investigated with the aim of stimulating the intended LLSAW and suppressing spurious modes concurrently. Optimization results reveal that the LLSAW mode wave propagating in X-35°Y LN/SiC piezoelectric-on-insulator (POI) bilayer structure possesses a large kt2 without significant interference from other spurious modes. To verify the theoretical analyses, LLSAW resonators were fabricated and exhibited a near spurious-free response with the operating frequency over 6 GHz, and kt2 as large as 22.7%. This work demonstrates a high-performance LLSAW resonator on the POI platform with a simple prototype as well as potentially providing a high-frequency filtering solution for 5G applications in the 6-GHz spectrum.
Simultaneous enhancement of piezoelectricity and mechanical quality factor in relaxor-ferroelectric crystals via defect engineering
Authors: Tian Gang , Liu Fengying , Du Juan , Zhao Le , Qi Xudong , Zhao Minglei , Zheng Limei
Published: March 2023

Both high piezoelectric response and mechanical quality factors (Qm) are essential for high-power applications of ferroelectric materials. However, there always exists a trade-off between these two parameters, which makes the collaborative optimization to be a great challenge. Here, a hardening effect is achieved via defect engineering in the acceptor-doped PbTiO3-relaxor-ferroelectric crystals by alternating current poling technique. It is found that under the AC electric field, the defect diploes are decoupled into isolated charged defects and accumulate at domain walls, which strongly pin domain wall motions while promoting ferroelectric dipole dynamics. Consequently, simultaneous enhancement of d33 and Qm is realized, where d33 increases by 16% and Qm enhances by 51%. This work offers an efficient and convenient approach in material design for practical high-power piezoelectric applications.
The flow around a forced cylinder between two parallel walls
Authors: Mandujano Francisco , Rechtman Raúl , Málaga Carlos
Published: March 2023

The vortex induced vibrations of a cylinder tightly confined in a narrow channel were numerically studied in two dimensions. Attached to a linear spring and subject to hydrodynamic forces and torques, the circular cylinder is free to move in both the cross-flow and in-line directions as well as to rotate about its axis. Low mass ratios and moderate Reynolds numbers were considered. The cases where boundaries, either physical or numerical, are far from the cylinder have deserved much attention, and share some of the phenomenology observed in the system here studied. As the upstream flow is increased, the tightly confined system shows an initial branch, followed by a synchronization or lock-in region that ends in a decoherence region. Nevertheless, within the lock-in region, no clear upper and lower branches appear when the cylinder is placed in a narrow channel, instead the system's behavior sensibly depends on the mass ratio. We managed to find a modified Strouhal parameter that collapses the range of excitation for the reduced masses considered and suggests a scaling for the system's natural frequency in the medium. Results offer a portrait of the motion, forces, and flow around the cylinder under such constrains.
Extended x-ray absorption fine structure measurement of ramp compressed Ti using laser-irradiated metallic foil as x-ray source on SGIII prototype laser facility
Authors: Hu Yun , Wang Zhebin , Zhang Jiyan , Xue Quanxi , Ye Qing , Jiang Shaoen
Published: March 2023

Laser-irradiated metallic foils were considered as x-ray sources for extended x-ray absorption fine structure (EXAFS) measurements and confirmed by experiments on the SGIII prototype facility. The Au foils were irradiated by laser beams with a total energy of 2.77 kJ and full width at half maximum (FWHM) of 1 ns to create an x-ray source. The x-ray emission was spectrally smooth in the energy range of Ti EXAFS, the FWHM of Au foil x-ray radiation pulse in the energy range of 0.1–4000 eV was 0.99 ns, and the FWHM of x-ray pulse in the energy range of 5000–6000 eV was deduced to be 0.55 ns according to simulation results. A shaped laser pulse was designed to achieve the Ti sample’s laser-direct-driven ramp compression process. By creating a quasi-stable state lasting longer than 1 ns as the probing window during the compression process, the demand for temporal resolution was reduced. EXAFS spectra of compressed Ti in α and ω-phase were obtained and compared, and structural phase transition was verified by EXAFS pattern changes. The velocity of the back interface of the Ti sample was measured by the velocity interferometer system for any reflector, and the maximum of the deduced pressure in the middle of the Ti sample was 8.2 GPa, which is consistent with the α-ω phase transition.
A theory-informed machine learning approach for cryogenic cavitation prediction
Authors: Zhu Jiakai , Guo Fangtai , Zhu Shiqiang , Song Wei , Li Tiefeng , Zhang Xiaobin , Gu Jason
Published: March 2023

Inferring cryogenic cavitation features from the boundary conditions (BCs) remains a challenge due to the nonlinear thermal effects. This paper aims to build a fast model for cryogenic cavitation prediction from the BCs. Different from the traditional numerical solvers and conventional physics-informed neural networks, the approach can realize near real-time inference as the BCs change without a recalculating or retraining process. The model is based on the fusion of simple theories and neural network. It utilizes theories such as the B-factor theory to construct a physical module, quickly inferring hidden physical features from the BCs. These features represent the local and global cavitation intensity and thermal effect, which are treated as functions of location x. Then, a neural operator builds the mapping between these features and target functions (local pressure coefficient or temperature depression). The model is trained and validated based on the experimental measurements by Hord for liquid nitrogen and hydrogen. Effects of the physical module and training dataset size are investigated in terms of prediction errors. It is validated that the model can learn hidden knowledge from a small amount of experimental data and has considerable accuracy for new BCs and locations. In addition, preliminary studies show that it has the potential for cavitation prediction in unseen cryogenic liquids or over new geometries without retraining. The work highlights the potential of merging simple physical models and neural networks together for cryogenic cavitation prediction.
The electronic structure of β-TeO2 as wide bandgap p-type oxide semiconductor
Authors: Shi Jueli , Sheng Ziqian , Zhu Ling , Xu Xiangyu , Gao Yun , Tang Dingliang , Zhang Kelvin H. L.
Published: March 2023

Wide bandgap oxide semiconductors have gained significant attention in the fields from flat panel displays to solar cells, but their uses have been limited by the lack of high mobility p-type oxide semiconductors. Recently, β-phase TeO2 has been identified as a promising p-type oxide semiconductor with exceptional device performance. In this Letter, we report on the electronic structure of β-TeO2 studied by a combination of high-resolution x-ray spectroscopy and hybrid density functional theory calculations. The bulk bandgap of β-TeO2 is determined to be 3.7 eV. Direct comparisons between experimental and computational results demonstrate that the top of a valence band (VB) of β-TeO2 is composed of the hybridized Te 5s, Te 5p, and O 2p states, whereas a conduction band (CB) is dominated by unoccupied Te 5p states. The hybridization between spatially dispersive Te 5s2 states and O 2p orbitals helps us to alleviate the strong localization in the VB, leading to small hole effective mass and high hole mobility in β-TeO2. The Te 5p states provide stabilizing effect to the hybridized Te 5s-O 2p states, which is enabled by structural distortions of a β-TeO2 lattice. The multiple advantages of large bandgap, high hole mobility, two-dimensional structure, and excellent stability make β-TeO2 a highly competitive material for next-generation opto-electronic devices.
Narrow range of early habitable Venus scenarios permitted by modeling of oxygen loss and radiogenic argon degassing
Authors: Warren Alexandra O. , Kite Edwin S.
Published: March 2023

Whether Venus was ever habitable is a key question driving missions to Earth’s sister planet in the next decade. Venus today has a dry, O
2
-poor atmosphere, but recent work has proposed that early Venus may have had liquid water [J. Krissansen-Totton, J. J. Fortney, F. Nimmo,
Planet. Sci. J.
2, 216 (2021)] and reflective clouds that could have sustained habitable conditions until 0.7 Ga [J. Yang, G. Boué, D. C. Fabrycky, D. S. Abbot,
Astrophys. J.
787, L2 (2014), M. J. Way, A. D. Del Genio,
J. Geophys. Res.: Planets
125, e2019JE006276 (2020)]. Water present at the end of a habitable era must since have been lost by photodissociation and H escape, causing buildup of atmospheric oxygen [F. Tian,
Earth Planet. Sci. Lett.
432, 126–132 (2015)]. We present a time-dependent model of Venus’s atmospheric composition starting from the end of a hypothetical habitable era with surface liquid water. We find that O
2
loss to space, oxidation of reduced atmospheric species, oxidation of lava, and oxidation of a surface magma layer formed in a runaway greenhouse climate can remove O
2
from up to 500 m global equivalent layer (GEL) (30% of an Earth ocean), unless melts on Venus had a much lower oxygen fugacity than Mid Ocean Ridge melts on Earth, which increases the upper limit twofold. Volcanism is required to supply oxidizable fresh basalt and reduced gases to the atmosphere but also contributes
40
Ar. Consistency with Venus’s modern atmospheric composition occurs in less than 0.4% of runs, in a narrow parameter range where the reducing power introduced by O
2
loss processes can balance O
2
introduced by H escape. Our models favor hypothetical habitable eras ending before 3 Ga and very reduced melt oxygen fugacities three log units below the fayalite–magnetite–quartz buffer (
f

O
2

< FMQ−3), among other constraints.
Endogenous
l
- to
d
-amino acid residue isomerization modulates selectivity between distinct neuropeptide receptor family members
Authors: Yussif Baba M. , Blasing Cole V. , Checco James W.
Published: March 2023

The
l
- to
d
-amino acid residue isomerization of neuropeptides is an understudied post-translational modification found in animals across several phyla. Despite its physiological importance, little information is available regarding the impact of endogenous peptide isomerization on receptor recognition and activation. As a result, the full roles peptide isomerization play in biology are not well understood. Here, we identify that the
Aplysia
allatotropin-related peptide (ATRP) signaling system utilizes
l
- to
d
-residue isomerization of one amino acid residue in the neuropeptide ligand to modulate selectivity between two distinct G protein-coupled receptors (GPCRs). We first identified a novel receptor for ATRP that is selective for the D2-ATRP form, which bears a single
d
-phenylalanine residue at position 2. Using cell-based receptor activation experiments, we then characterized the stereoselectivity of the two known ATRP receptors for both endogenous ATRP diastereomers, as well as for homologous toxin peptides from a carnivorous predator. We found that the ATRP system displayed dual signaling through both the Gα
q
and Gα
s
pathways, and each receptor was selectively activated by one naturally occurring ligand diastereomer over the other. Overall, our results provide insights into an unexplored mechanism by which nature regulates intercellular communication. Given the challenges in detecting
l
- to
d
-residue isomerization from complex mixtures de novo and in identifying receptors for novel neuropeptides, it is likely that other neuropeptide-receptor systems may also utilize changes in stereochemistry to modulate receptor selectivity in a manner similar to that discovered here.
Integrated monolingualism and audism governing Spanish Sign-Language users’ self-determination in the legal
system
Authors: Monzó-Nebot Esther , González-Montesino Rayco H.
Published: March 2023

Many legal systems have begun to adjust their social and linguistic practices to accommodate non-dominant social
groups. However, linguistic diversity is often framed as an exception, and interpreters are viewed as a service to address these
exceptions rather than as part of broader structural changes to enable access to justice. This article explores the access to and
participation in the Spanish legal system of Spanish Sign-Language users (SSLUs) who are deaf or heard of hearing. Through
semi-structured interviews with SSLUs, the article elicits their perceptions of the legal field. These data are analyzed from the
perspective of self-determination theory (Deci and Ryan 1985) to identify how SSLUs’
psychological needs of competence, autonomy, and relatedness are linked to the social, cultural, and economic capital invested and
distributed through social practices. The goal is to clarify how SSLUs’ habitus sustains or resists monolingual and audist
ideologies establishing hierarchies between language communities.
Hardness and tensile strength of carbon nanoparticle-lithium borate composites
Authors: Kaur Manpreet , Bharj Jyoti
Published: March 2023

Carbon nanoparticle (CNP)-lithium borate glass composites are synthesised by melt-quenching technique to study the influence of CNPs addition on the mechanical properties of the primary glass. Three different glass composites are fabricated by varying the weight% of CNPs. The hardness and tensile strength are found to increase by 2.65 times the primary glass with the addition of 0.4 weight% of CNPs. The homogeneous dispersion and close-packing of nanoparticles achieved in the resultant glass matrix account for this improvement. The closed-packed structure reduces the free volume between molecules, thereby limiting their movement and enhancing interfacial bonding. The formation of such a cross-linked structure with the addition of CNPs is supported by density measurements, electron microscopy images, and glass transition temperature studies.
Self-progress aggregate learning for weakly supervised salient object detection
Authors: Sun Wanchun , Feng Xin , Liu Jingyao , Ma Hui
Published: March 2023

The task of salient object detection aims to find the most salient object from the samples. In the field of weakly supervised learning, the existing weakly supervised salient object detection (WSSOD) methods often fail to utilize the limited label information (such as self-affinity or edge features, and scale transform) for learning. Therefore, this paper proposes a self-progress aggregate learning method named SPAL. First, the feature optimization scheme of the edge information module is put forward based on analysis of the problems existing in the current convolutional neural network for detection of the edge information of the object. Obviously, the salient object has a low requirement for high-level information, In particular, in order to improve the utilization rate of the network structure without increasing its complexity, the affinity global context is design in view of the particularity of the structure of a salient object. The structure of a salient object not only depends on the deep-level semantic feature information to a certain extent, but also has a certain guiding effect on the object position and edge information. Second, high-level affinity information is used to complement the slight-level edge information globally, and the scale attention module is adopted to guide the network to adapt the multi-scale reinforcement feature learning ability for the salient object regions. Our method SPAL achieved better experimental results than the other competitive models for comparison on five benchmark data sets (i.e. for DUTS-TEST, compared with CCFNet our method achieved an improvement of 0.6% for mean absolute error (MAE), 5.1% for Fb, and 1.1% for Eℰ
), which demonstrates the effectiveness of our proposed method.
Dynamics and performance evaluation of a vortex-induced vibration energy harvester with hybrid bluff body
Authors: Li H T , Ren H , Shang M J , Lv Q , Qin W Y
Published: March 2023

To investigate the influence of bluff body with a variable section on the vortex-induced vibration (VIV) energy harvesting performance, a series of hybrid cylinders are designed and a quantitative comparison is presented. The basic elements of hybrid bluff body are the D-shaped (D) and original circular-shaped cylinders (O), and the length ratio between the O-shaped part and the D-shaped part is fixed. According to the arrangement order, three kinds of hybrid bluff bodies are termed as ODO, ODODO and DOD. A distributed model is developed and the numerical simulation is carried out to verify the response. Corresponding wind tunnel experiments are conducted, and the results reveal that compared to the bluff body with a circular cylinder, the hybrid bluff bodies such as ODODO and DOD can enhance the VIV and thus increase the output significantly. Moreover, the lock-in regions with the ODODO and DOD shapes will increase by 12.5% and 62.5%, respectively. However, the results also indicate that some type of arrangement such as ODO will suppress the energy harvesting performance. Furthermore, the computational fluid dynamics method is employed to reveal the physical mechanism of flow field around the hybrid bluff body. The results show that the integration of D-shape prism in a cylinder along an axial direction could influence aerodynamics. A faster boundary layer separation occurs for the VIV energy harvesters with the hybrid cylinders of ODODO and DOD, which could improve the energy conversion efficiency from flow-induced vibrations. However, the aerodynamic force is restricted and response is suppressed as a D-shaped cylinder is sandwiched between two O-shaped cylinders.
Photo-electrochemical water splitting and electrochemical performance of silicon nanowire arrays
Authors: Kadhim Z J , Mahdi M A
Published: March 2023

Silicon nanowires (SiNWs) were prepared using n-Si(100) by a simple two-step metal-assisted chemical etching (MACE) approach with different durations of 15 and 30 min. Surface morphology, structural, and optical properties of prepared SiNWs were investigated using Scanning Electron Microscope (SEM), x-ray diffraction (XRD) and UV–vis absorption, respectively. Under visible light, a photoelectrochemical cell (PEC) was used to measure the properties of a photoanode device that was fabricated based on n-SiNWs for splitting water. At 0.78 V, the SiNWs that were prepared in 30 min had a photocurrent density of 3.72 mA.cm−2 and a photoconversion efficiency (η) of 1.37%. Cyclic voltammetry (CV) measurements showed that both the n-Si(100) wafer and the n-SiNWs that were made with etching times of 15 and 30 min showed faradaic behavior with redox peaks. Electrochemical impedance spectroscopy (EIS) showed that the SiNWs photoanode prepared with 30 min of etching time had a charge transfer resistance of 3112.3. This is low enough to make it easy for charge to move across the interface. The Mott-Schottky (M-S) analysis revealed a high concentration of carriers of 4.77 × 1021 cm−3 at the working electrode/electrolyte interface,
Ultrasonic study and molecular dynamics simulation of propylene glycol at pressures up to 1.4 GPa
Authors: Fomin Yu D , Danilov I V , Gromnitskaya E L
Published: March 2023

We report ulsrasonic measurements of the density and bulk modulus of propylene glycol at room temperature and at the temperature of liquid nitrogen up to a pressure of 1.4 GPa. We perform molecular dynamics simulations with two different force fields—COMPASS and Charmm. We show that the COMPASS force field reproduces the experimental data with high accuracy. For this reason we employ this force field to analyze the microstructure and hydrogen bonding in the system. We find that the number of hydrogen bonds does not depend on pressure.
Multi-wavelength passively Q-switched laser with Co2+:ZnSe thin film coated microsphere
Authors: Wu Zhujing , Zhang Hong , Zhu Yuehong , Huang Yulei , Yang Huomu , Deng Guoliang , Zhou Shouhuan
Published: March 2023

We experimentally demonstrate an all-fiber passively Q-switched erbium-doped laser based on a microsphere resonator coated with Co2+:ZnSe film, which can achieve multi-wavelength pulse laser. With electron beam evaporation technology, the saturable absorber (SA) with a modulation depth of 55% was prepared by depositing Co2+:ZnSe film on the microsphere for the loss modulation of the laser cavity. The passively Q-switched output pulses were obtained by inserting the SA into the laser cavity and the narrowest pulse width of ∼3 μs was obtained. The fiber laser can stably output quintuple-wavelength laser pulses with a 3 dB bandwidth of ∼0.1 nm. The wavelength interval of multi-wavelengths was stably maintained at ∼1 nm and the smallest optical signal-to-noise ratio of ∼10 dB at the pump power of 400 mW was measured. The signal-to-noise ratio was ∼58 dB, which confirms excellent output stability. The results prove that it is a promising SA device to achieve passively Q-switched multi-wavelength pulse fiber lasers.
Numerical Simulation of Flow Over Airfoil and Its Optimization
Authors: Xu Rick E. , Wu Zhe
Published: March 2023

Airfoils are one of the most important factors in determining an airplane’s ability to fly. As such, their optimization holds important ramifications for the continual need to improve airplane performance. In this paper, the optimization of airfoil design is explored through numerical computational fluid dynamics. This paper first investigates the effects of Angle of Attack on airfoil lift/drag ratios, which is shown to have a significant influence on the performance of airfoils. Then, the effects from thickness are explored, and it is found that the influence of thickness is highly dependent on the specific shape of airfoil. In addition, in order to further improve airfoil aerodynamic performance, a type of modified airfoil with an additional tip is developed and simulated. The results indicate that airfoils with additional tips can perform better, but only with the proper combination of tip parameter values. For example, the modified airfoil with a tip of 0.03 L length at a 25° tip angle bested that same airfoil without an additional tip. Finally, it is found that the Backpropagation machine-learning algorithm, when trained with prior simulation data, can quickly predict lift and drag coefficients of airfoils. The results in this paper could facilitate the further optimization of airfoil design.
Research on turbulence model for simulation of wind flow in mountain areas of micro-topography
Authors: Yin Yuan , Li Yangsen , Lin Ruizong , Liu Zhiwei , Fu Benzhao , Huang Guo , Zhang Hongjie
Published: March 2023

The accuracy of wind flow simulation in mountain area in micro-topography is related to discrete scheme, turbulence model and wall function. In this paper, the standard hill model is adopt to analyze the calculation accuracy of different turbulence models. Four turbulence models, including RNG k-ε, k-ω, SST k-ω and TSST k-ω, were used in the calculation, and were compared with the result of wind tunnel test. The calculation results with the second-order upwind scheme, the SST or TSST turbulence model and the scalable wall function are basically consistent with results of wind tunnel test.
The Application of Boundary Element Method for The Solution of The Inverse Heat Conduction
Authors: Wen Jin , Xiang Ziyan , Li Longlong , Zhang Yulu , Yan Huili , Zhu Yi
Published: March 2023

In this paper, the general and supplementary conditions are used to determine the inverse heat conduction in the parabolic equation. The measured conditions ensure that the inverse problem has a unique solution, but the solution is not stable, so the problem is ill-posed. Using the boundary element method to discretize the original problem, it is used to solve the problem. On this basis, the direct method, the least square method and the regular method are tried. Finally, the minimal energy method is used to solve the system. Numerical experiments are carried out and the results are discussed.
Examination of Star Formation Rate enhancement in galaxy pairs selected based on data from Illstris TNG
Authors: Chen Yiru
Published: March 2023

Star Formation Rate (SFR) is one of the most important properties of galaxies, which offers a good insight of galaxy evolution. Generally, interactions with the small and large scale environment may affect the SFR of the galaxy. Therefore, an examination of SFR of galaxy pairs is carried out in this paper to investigate the partner galaxy impacts on the evolution process of one galaxy. Compared with isolated galaxies, the SFR of galaxy pairs is enhanced due to interactions with the large scale environment (e.g., the tidal force). This finding confirms that interactions with the large scale environment will affect the galaxy evolution process and further work can be done to examine the impacts of other interactions. These results shed light on the deeper understanding of galaxy evolution process and call on more investigation of large scale environment of the galaxy.
The impact of the dark matter on galaxy formation
Authors: Diao Junwen , Wei Shibiao , Wei Zherui , Liu Chang
Published: March 2023

Contemporarily, dark matter exerts dominant impacts on galaxy formation, which is the spine bone of the galaxy. Herein, we investigate the attraction effect of initial dark matter distribution on the normal matter (hydrogen and other gases), which will form the dark matter halos. Subsequently, an introduction to the properties of dark matter halos and some disputes about it are demonstrated. Besides, the cold dark matter (CDM) is chosen to fit the current observation and interpret the influences of dark matter on galaxy formation. Overall, this paper offers a clear procession of the impact of dark matter on galaxy formation, which will be guideline for future development of both galaxy formation theory as well as dark matter detection.
Longitudinal stability analysis of underwater towed body based on CFD
Authors: Liu Xianlong , Liu Cheng , Chen Cheng , Kui Haixing
Published: March 2023

The angle of the underwater towed body is very important when it is towed passively. The steady angle is calculated by cubic spline interpolation and CFD. Generally, in order to obtain a stable pitch angle, it is necessary to adjust the angle of the tail rudder plate. With this method, stable angle can be obtained quickly and effectively, which can be used as reference for corresponding scheme design.
Frequency Analysis of Submerged Cylindrical Shell near the Rigid Wall with Hydrostatic Pressure
Authors: Wang Peng , Niu Qingyong , Zhang Hao
Published: March 2023

Fluid boundary is quite common to be noted in engineering, for example, water tank, or the ocean. The tank wall could be regarded as rigid wall. Besides, for structures submerged in water, the hydrostatic pressure actually existes, and its effect is important especially for big pressure level. In this work, the rigid wall and hysrostatic pressure are both accounted, and natural frequency is predicted for submerged cylindrical shell near rigid wall with high hydrostatic pressure. Results show that rigid wall effect will reduce modal frequency. And rigid wall effect will be more and more small with increase of distance between shell and rigid wall. It’s finally be ignored while the gap is large enough. Hysrostatic pressure will also reduce modal frequency, and its influence is obvious for high pressure level.
Simulation study on passive cavitation suppression for a typical hydrofoil
Authors: Zhang Jinlan , Wang Yun , Dong Liang , Wu Jianwei , Wang Wei , Li Zhijian
Published: March 2023

A passive cavitation suppression structure with flow barriers on its surface was proposed for a typical hydrofoil (NACA66 MOD). Based on the homogeneous equilibrium model and the Zwart-Gerber-Belamri cavitation model, the cavitation characteristics around the hydrofoil before and after flow barriers on hydrofoil surface at a typical operating condition are simulation investigated. Results show that the flow barriers provide on hydrofoil surface are capable of regulating and controlling the cavitation flow field, suppressing 47.1 percent of cavitation flow. By coupling the distribution of cavitation shape, re-entrant jet and pressure field of the hydrofoil with fluid flowing around, and analysing the periodic change of flow field, it is found that to a certain extent, the flow barrier provided on hydrofoil suction surface inhibited the development and shedding of cavitation.
CFD analysis and prediction of centrifugal pump cavitation performance based on three-dimensional two-phase flow between impeller and worm gear
Authors: Ma Shi , Liu Yiou
Published: March 2023

Cavitation performance is an important performance indicator of centrifugal pumps. The occurrence of cavitation will trigger a complex gas-liquid two-phase flow, which will reduce the efficiency of a low ratio centrifugal pump and cause machine vibration, as well as damage to the impeller, seriously affecting the working performance and preventing its normal operation. In this paper, CFD numerical simulation is used to analyze the cavitation characteristics of a centrifugal pump, obtain its internal flow law, calculate the cavitation margin of the device and the head generated by the pump under each inlet condition, and thus predict the critical cavitation margin of the pump at this flow point.
Modeling of Micro-downburst accompanied with rain and analysis of its influence on artillery firing accuracy
Authors: Wang Jin , Tian Junwei , Zhang Zhen , Lei Xiaoming , Sun Guangyu , Guo Xiaodan
Published: March 2023

The characteristics of wet micro burst are more complex, which will cause some deviation on the artillery range, side deviation and other parameters, and have a great influence on the artillery shooting accuracy. Taking 155 mm artillery explosive shell as the research object, based on vortex ring principle and fluid mechanics, the micro-downburst and raindrop motion model was established, which was integrated into the wet micro-downburst model suitable for ballistic analysis and calculation. The wet micro-downburst model was combined with the 6-DOF external ballistic model of artillery. Simulation and analysis of the effect of different initial vortex ring center induced velocity on the firing accuracy of flat firing and curved firing. The experimental results show that for long-range firing, the range of the artillery decreases with the increase of the induction velocity of the initial vortex ring center, which seriously affects the firing accuracy and killing effect of the artillery.
Analysis of Dynamic Performance of Synchronous Double Proportional Valve Based on Digital Simulation
Authors: Cai Biaohua , Zhang Maosen , Hu Qiuxu , Zhang Zheng , Shi Zhaocun
Published: March 2023

The dynamic characteristic parameters of the synchronous dual-proportional pressure integrated valve are of great significance to its research. Among them, the outlet pressure tracking error and the flow resistance characteristics of the internal flow field have a great influence on the dynamic characteristics of the valve. The tracking error of the valve under specific working conditions is analyzed by means of digital simulation, and the flow resistance characteristics of the internal flow field are further obtained.
Production of fuels by pyrolysis of waste plastics: technical notes
Authors: Kafle Saroj Raj , Gaire Pragati , Tuladhar Nerisha
Published: March 2023

This paper described the plant scale catalytic process of the plastic waste materials in order to obtain an alternative fuel from three plastic wastes Polypropylene (PP), Polystyrene (PS) and Polyethylene (PE). Pyrolysis is the thermochemical decomposition of plastics at elevated temperatures (in absence or little supply of oxygen) into a range of useful products: gas, liquid, and solid residue. These waste have plastics consisting of PP, PE and PS, are first sorted manually and crushed by using crusher and finally feed in the reactor enclosed in the burner maintaining the reaction temperature about 500°C. Nitrogen gas is used to create inert environment and for fluidization in reactor. The produced cracked gas is now sent to be condensed to a condenser followed by the series of cyclone separator and electrostatic precipitator then finally feed into the liquid vapor separator. The plastic pyrolysis plant is design of capacity 3.2 tons of plastics each day, obtained 80% gaseous fuel and 7% Liquid and remaining as residue. The variation of yield of the products according to increase in temperature is also shown in this paper.
Numerical Investigation of Flow Behaviour and Erosion Potential in the Side-Wall Clearance Between Guide Vane and Runner
Authors: Pandey A , Gautam S , Chitrakar S , Acharya N , Bijukchhe P L
Published: March 2023

In the hydropower plants exposed to excessive sediment concentration, the components of Francis turbines, especially the regions of Guide Vanes (GVs) and Runner Vanes (RVs) are severely eroded. The side-wall clearance between GV and runner is present in these turbines to separate the rotating and stationary components. The height difference between the runner inlet and GV outlet covers, introduced during the fabrication or assembly process might play a crucial role in accelerating the erosion process in these components. This study is focused on numerical analysis of simplified geometries that replicate different scenarios of the height difference and consequent flow behaviour in the side-wall clearance of Francis turbines. The numerical analysis is done in OpenFOAM using the available solver adopting the finite volume method (FVM). The numerical study is compared with the experimental results obtained from Rotating Disc Apparatus (RDA). The numerical analysis shows the vortex formation in the side-wall clearance region which traps the sediment particles. Such vortex formation causes erosion in the region. The vortex formation and flow behaviour in different height difference scenarios vary with each other and so does the erosion pattern in the experimental results.
Structural conductive carbon nanotube nanocomposites for stretchable electronics
Authors: Ahn Jaekyeong , Noh Seunghwan , Kim Danbi , Kim Bo-Seok , Kim Sejung , Song Youngjun
Published: March 2023

Carbon nanotube (CNT) nanocomposites have been widely used for electronic devices because of their high conductivity and ease of processing. However, these nanocomposites have limited functionality because of their rigid intrinsic mechanical properties. In this study, we fabricated a stretchable serpentine structure using a CNT nanocomposite with a carboxymethyl cellulose binder. For a flexible mold, a polydimethylsiloxane (PDMS) was cast by the stretchable serpentine structure fabricated by a 3D printer. The CNT nanocomposite slurry was squeegeed into the serpentine-patterned PDMS mold. Fourier-transform infra-red spectroscopy and scanning electron microscopy were used to analyze the material properties of the nanocomposites with 15–45 wt% CNTs. We analyzed the serpentine grid structure using current-voltage curves, strain resistance values, and the Joule heating effect. Next, we developed the structural CNT nanocomposite electrode (SCNE) that was insulated by PDMS, and induced a skin-warming effect by Joule heating. Furthermore, light emitting diodes (LEDs) were implanted in series into a T-shaped linear SCNE, which had greater stretchability. The nine LEDs embedded in the SCNE were successfully operated by applying 20 V during the bending of the structure. Finally, the serpentine-shaped linear SCNEs with serially-implanted LEDs were programmed to light the LEDs in unison with the beat of a song.
Does Cash Really Mean Trash? An Empirical Investigation into the Effect of Retailer Price Promotions on Household Food Waste
Authors: van Lin Arjen , Aydinli Aylin , Bertini Marco , van Herpen Erica , von Schuckmann Julia
Published: March 2023

Retailer price promotions, and in particular multi-unit deals such as the ubiquitous “buy one, get one,” are often criticized as a cause of food waste, presumably because they lure households into buying more than they can realistically consume. In this research, the authors combine field data and experiments to provide the first systematic test of this claim. The field data, which span eight frequently purchased perishable foods, show no evidence of a positive relationship between single-unit or multi-unit price promotions and food waste. In fact, households that took advantage of a multi-unit deal reported wasting less than did households paying regular prices (RPs), but only when the quantity purchased was larger than usual. Given this result, and that households also reported consuming and freezing more, the authors hypothesize that promotion-induced overbuying triggers a concern for food waste that encourages waste prevention. One experiment finds support for this mechanism. A second experiment shows that the effect on food waste concerns is moderated by perishability and versatility but unaffected by convenience and healthiness. Overall, then, this research invites regulators and other professionals to rethink their stance on price promotions and work with retailers to design smart campaigns that motivate waste awareness and management.
Definitions and Conceptualizations of the Practice Context in the Health Professions: A Scoping Review
Authors: Thomas Aliki , Rochette Annie , George Catherine , Iqbal Muhammad Zafar , Ataman Rebecca , St-Onge Christina , Renaud Jean-Sébastien
Published: March 2023

Introduction:

Health care professionals work in different contexts, which can influence professional competencies. Despite existing literature on the impact of context on practice, the nature and influence of contextual characteristics, and how context is defined and measured, remain poorly understood. The aim of this study was to map the breadth and depth of the literature on how context is defined and measured and the contextual characteristics that may influence professional competencies.

Methods:

A scoping review using Arksey and O'Malley's framework. We searched MEDLINE (Ovid) and CINAHL (EBSCO). Our inclusion criteria were studies that reported on context or relationships between contextual characteristics and professional competencies or that measured context. We extracted data on context definitions, context measures and their psychometric properties, and contextual characteristics influencing professional competencies. We performed numerical and qualitative analyses.

Results:

After duplicate removal, 9106 citations were screened and 283 were retained. We compiled a list of 67 context definitions and 112 available measures, with or without psychometric properties. We identified 60 contextual factors and organized them into five themes: Leadership and Agency, Values, Policies, Supports, and Demands.

Discussion:

Context is a complex construct that covers a wide array of dimensions. Measures are available, but none include the five dimensions in one single measure or focus on items targeting the likelihood of context influencing several competencies. Given that the practice context plays a critical role in health care professionals' competencies, stakeholders from all sectors (education, practice, and policy) should work together to address those contextual characteristics that can adversely influence practice.
Advancing Teamwork in Health Care Through Continuing Education Joint Accreditation
Authors: Kawczak Steven , Fernandez Anthony P. , Mooney Molly
Published: March 2023

Teamwork is a necessity for effective care of patients in the current health care environment. Continuing education providers are best positioned to teach health care professionals about teamwork. However, health care professionals and continuing education providers largely operate in single-profession–based environments and thus need to change their programs and activities to achieve team improvement education goals. Joint Accreditation (JA) for Interprofessional Continuing Education is designed to advance teamwork to improve quality care through education programs. However, achieving JA requires significant changes to an education program that are multifaceted and complex to implement. Although challenging, implementation of JA is an effective way to advance interprofessional continuing education. Here, we discuss numerous practical strategies that can aid education programs to prepare for and achieve JA, such as attaining organizational alignment and provider adaptation to expand curriculums, reinventing the education planning process, and implementing tools to help manage the joint accredited program.