bluuebunny/crossref_metadata_2025 huggingface dataset:
Continuous Analgesia with Intercostal Catheterization after Thoracoscopy
Authors: Wang Yifei , Sun Qi , Huang Yiling , Yang Qinghua , Chen Rong , Zhang Xianwei , Zhao Xuewei , Wang Mingdong
Published: September 2023

Background There are few studies on continuous intercostal nerve block after single operation hole thoracoscopic surgery, that is, two-port thoracoscopic surgery.

Objective To evaluate the analgesic effect of continuous intercostal nerve block after thoracoscopic surgery.

Methods A total of 80 patients who underwent single operation hole thoracoscopic surgery in our hospital between September 2020 and June 2021 were enrolled and divided into two groups. Based on basic analgesia, an intercostal catheter was placed during the operation for continuous intercostal block analgesia after the operation in the experimental group (group A, n = 40). The control group (group B, n = 40) was treated with sufentanil intravenous analgesia after surgery, which is namely “basic analgesia.” The postoperative pain scores, restlessness during the recovery period, effect on reducing opioid use, postoperative chest complications, patient satisfaction, etc., were compared between the two groups.

Results The pain scores of patients in group A were significantly lower compared with those in group B at 12, 24, 36, and 48 hours after surgery (3.325 ± 1.163 vs. 4.550 ± 1.176, 2.650 ± 1.001 vs. 4.000 ± 1.038, 2.325 ± 0.917 vs. 3.700 ± 0.966, and 1.775 ± 1.050 vs. 3.150 ± 1.075, p < 0.001, respectively). Sufentanil consumption in group A was significantly lower than in group B at 48 hours after surgery (98.625 ± 4.158 vs. 106.000 ± 7.228, p < 0.001).

Conclusion Multimodal analgesia is ideal for early pain control after thoracotomy. A continuous intercostal nerve block can effectively reduce postoperative pain in patients.
Effectiveness of Phytic Acid as an Etchant in Dentistry: A Systematic Review
Authors: Dharmalingam Ishwarya , Samuel Victor , Ramar Kavitha , Sekar Rajakumar , Kasi Anand , Ponraj Sujitha , Jaganathan Gayathri
Published: September 2023

The aim of this study was to assess the effect of phytic acid and to compare it with the phosphoric acid etching through a systematic review. systematic search was carried out using PubMed/MEDLINE, Cochrane library, Indmed, Scopus, and Liliacs databases conducted upto January 2022. In vitro studies comparing phytic acid and phosphoric acid as an etchant on tooth surfaces that performed bond strength, smear layer removal, collagen degradation and monomer penetration were included. The risk of bias was assessed considering Checklist for Reporting In-vitro Studies guidelines. Five studies were chosen for full-text assessment out of 830 that were potentially eligible. The studies found that phytic acid improved bond strength, collagen degradation, smear layer removal, and monomer penetration. Every study had a moderate-to-high risk of bias. Phytic acid enhanced the etch and rinse adhesive's binding strength to dentin, effectively eradicated the smear layer, protected dentin collagen from degradation, and had better resin infiltration and minimal effect on pulpal cells.
FDG PET/CT Depicting Right Iliac Vein Tumor Thrombosis following Low Anterior Resection in Rectal Cancer Patient: A Case Report and Literature Review
Authors: Al-Ibraheem Akram , Moghrabi Serin
Published: September 2023

Venous tumor thrombus is a rare complication of rectal cancer but is more common in other types of cancer, like renal cell carcinoma and hepatocellular carcinoma. The usual site of tumor thrombus in rectal cancer patients is the inferior mesenteric vein (IMV), which is seldom seen in the common iliac vein, with only a few cases reported till now. We present a case of fluorodeoxyglucose (FDG) avid right iliac vein tumor thrombosis after low anterior resection in a patient with rectal cancer and review the literature.
Behavioral Health Decision Support Systems and User Interface Design in the Emergency Department
Authors: Jones Nicholas W. , Song Sophia L. , Thomasian Nicole , Samuels Elizabeth A. , Ranney Megan L.
Published: September 2023

Objective The objective of this qualitative study is to gauge physician sentiment about an emergency department (ED) clinical decision support (CDS) system implemented in multiple adult EDs within a university hospital system. This CDS system focuses on predicting patients' likelihood of ED recidivism and/or adverse opioid-related events.

Methods The study was conducted among adult emergency physicians working in three EDs of a single academic health system in Rhode Island. Qualitative, semistructured interviews were conducted with ED physicians. Interviews assessed physicians' prior experience with predictive analytics, thoughts on the alert's placement, design, and content, the alert's overall impact, and potential areas for improvement. Responses were aggregated and common themes identified.

Results Twenty-three interviews were conducted (11 preimplementation and 12 postimplementation). Themes were identified regarding each physician familiarity with predictive analytics, alert rollout, alert appearance and content, and on alert sentiments. Most physicians viewed these alerts as a neutral or positive EHR addition, with responses ranging from neutral to positive. The alert placement was noted to be largely intuitive and nonintrusive. The design of the alert was generally viewed positively. The alert's content was believed to be accurate, although the decision to respond to the alert's call-to-action was physician dependent. Those who tended to ignore the alert did so for a few reasons, including already knowing the information the alert contains, the alert offering information that is not relevant to this particular patient, and the alert not containing enough information to be useful.

Conclusion Ultimately, this alert appears to have a marginally positive effect on ED physician workflow. At its most beneficial, the alert reminded physicians to deeply consider the care provided to high-risk populations and to potentially adjust their care and referrals. At its least beneficial, the alert did not affect physician decision-making but was not intrusive to the point of negatively impacting workflow.
A review on device requirements of resistive random access memory (RRAM)-based neuromorphic computing
Authors: Yoon Jeong Hyun , Song Young-Woong , Ham Wooho , Park Jeong-Min , Kwon Jang-Yeon
Published: September 2023

With the arrival of the era of big data, the conventional von Neumann architecture is now insufficient owing to its high latency and energy consumption that originate from its separated computing and memory units. Neuromorphic computing, which imitates biological neurons and processes data through parallel procedures between artificial neurons, is now regarded as a promising solution to address these restrictions. Therefore, a device with analog switching for weight update is required to implement neuromorphic computing. Resistive random access memory (RRAM) devices are one of the most promising candidates owing to their fast-switching speed and scalability. RRAM is a non-volatile memory device and operates via resistance changes in its insulating layer. Many RRAM devices exhibiting exceptional performance have been reported. However, these devices only excel in one property. Devices that exhibit excellent performance in all aspects have been rarely proposed. In this Research Update, we summarize five requirements for RRAM devices and discuss the enhancement methods for each aspect. Finally, we suggest directions for the advancement of neuromorphic electronics.
Construct exchange-correlation functional via machine learning
Authors: Wu Jiang , Pun Sai-Mang , Zheng Xiao , Chen GuanHua
Published: September 2023

Density functional theory has been widely used in quantum mechanical simulations, but the search for a universal exchange-correlation (XC) functional has been elusive. Over the last two decades, machine-learning techniques have been introduced to approximate the XC functional or potential, and recent advances in deep learning have renewed interest in this approach. In this article, we review early efforts to use machine learning to approximate the XC functional, with a focus on the challenge of transferring knowledge from small molecules to larger systems. Recently, the transferability problem has been addressed through the use of quasi-local density-based descriptors, which are rooted in the holographic electron density theorem. We also discuss recent developments using deep-learning techniques that target high-level ab initio molecular energy and electron density for training. These efforts can be unified under a general framework, which will also be discussed from this perspective. Additionally, we explore the use of auxiliary machine-learning models for van der Waals interactions.
Research progress and prospect of polymer dielectrics
Authors: Zhou Le , Zhao Shuo , Xie Ping , Miao Xiang , Liu Sijie , Sun Nannan , Guo Mengfan , Xu Zongqi , Zhong Tingjun , Shen Yang
Published: September 2023

With the increasing demand for energy, how to store and release energy efficiently and stably has become an urgent research topic. Polymer dielectrics have become a kind of ideal dielectric materials in electrostatic capacitors for energy storage due to their advantages of light weight, easy fabrication, low cost, and high breakdown strength. It has a wide application prospect in smart power grids, new energy vehicles, pulse power weapons, electromagnetic guns, and lasers. However, existing polymer dielectrics cannot simultaneously possess the characteristics of high energy density, high breakdown field intensity, high charge and discharge efficiency, and low dielectric loss, thus limiting the development of compact, efficient, and reliable electronic power technology. In addition, the inherent thermal/field charge injection, excitation, and transport phenomena of polymer dielectrics make the resistivity and dielectric energy storage properties of polymer dielectrics decrease sharply under the combined action of high temperature and high electric field. In order to optimize the energy storage performance of polymer dielectrics (including room temperature and high temperature dielectrics), it has been obtained excellent dielectric breakdown strength, energy storage density, energy storage charge, and discharge efficiency from polymer nanocomposites, polymer/small molecule composites, polymer/polymer blends, new synthetic polymers, multilayer polymers, and other material systems. Based on these material systems, this review summarizes and compares these material systems, points out their advantages and disadvantages including the key problems, and puts forward suggestions for the future research.
Simulation analysis of electrical characteristics of P-gate enhanced HEMT with C-doped buffer layer
Authors: Wang Xiao , Lin Zhi-Yu , Zhang Yu-Min , Wang Jian-Feng , Xu Ke
Published: September 2023

The C-doped P-gate-enhanced HEMT (PEHEMT) is simulated by using the Silvaco T-CAD tool. The interaction among the C acceptor trap, electron, and hole in the buffer layer at different voltages promotes interesting electrical characteristic within the device. In off-state conditions, the peak electric field position shifts from the edge of gate to the edge of drain. During the process of peak electric field transfer, the gate electric field gradually saturates, and the increase rate of peak electric field shows a turning point at 350 V (Vd < 600 V). As the voltage further increases (Vd > 600 V), the increase rate of the drain electric field gradually slows down and tends to saturation, and the corresponding saturated gate electric field begins to increase. The uniform, quasi-linear, and step distributions of three different C acceptor in the buffer layer exhibit different degrees of current collapse under 1 ms bias stress, with values of 21.8%, 12.7%, and 12.8%, respectively. In this work, we have provided appropriate explanations for the above phenomena.
Observations of plasma waves generated by charged space objects
Authors: Bernhardt Paul A. , Scott Lauchie , Howarth Andrew , Morales George J.
Published: September 2023

A sampling of the environment around inert space objects has determined, which linear and nonlinear waves are created by moving space debris of all sizes. Plasma waves excited by satellites and space debris moving through the Earth's plasma in low earth orbit have been measured with in situ electric field sensors on other satellites. These orbit driven plasma waves are of interest for proximity detection of space debris and sources of electrostatic and electromagnetic noise on spacecraft. Satellites and other space objects moving through the near-earth ionosphere between 200 and 1000 km altitude become electrically charged by both electron collection and photo emission in sunlight. These hypersonic, charged objects can excite a wide range of plasma waves. Measurements with the Radio Receiver Instrument (RRI) on the Swarm-E satellite have shown that electromagnetic plasma waves from known objects can be observed out to ranges of tens of kilometers. The amplitude, spectral, and polarization changes of the RRI data are consistent with electromagnetic, compressional Alfvén waves launched by charged space objects traveling across magnetic field lines. In addition, electrostatic lower hybrid waves or nonlinear ion acoustic pinned oscillations may have been self-generated and measured on the Swarm-E satellite. It is proposed that measurements of these waves with local electric field measurements or remote electromagnetic wave scatter may be useful to design systems for the location of orbiting objects. Spatial and temporal details of spacecraft charging are key to understanding the extent of waves associated with the object motion in space plasmas.
Optical probing of magnet-induced transparent over-dense plasma in a whistler mode
Authors: Li K. , Yu W.
Published: September 2023

For the first time, optical probing of the highly magnetized over-dense plasma in a whistler mode is theoretically investigated, where the over-dense plasma becomes magnet-induced transparent (MIT) for right hand circularly polarized laser when the electron cyclotron frequency is higher than laser frequency. Applications of the popular optical diagnostics technologies (i.e., absorption, interferometry, shadowgraphy, and schlieren imaging) in the MIT plasma are studied in the measurement of plasma density, temperature, and strength of magnetic field. The “normal” Faraday rotation is expanded to region of B > 1 (B is the dimensionless magnetic field) for both over-dense plasma (n > 1, n is the dimensionless plasma density) and under-dense plasma (n < 1). For probing laser with higher intensity as to be able to heat up plasma collisionally, the power transmission is increased and intense laser is found to deposit more energy in the region of higher plasma density or weaker magnetic field.
Domain control and periodic poling of epitaxial ScAlN
Authors: Yang Fengyan , Yang Guangcanlan , Wang Ding , Wang Ping , Lu Juanjuan , Mi Zetian , Tang Hong X.
Published: September 2023

ScAlN is an emerging ferroelectric material that possesses large bandgap and strong piezoelectricity and holds great promises for enhanced χ(2) nonlinearity. In this study, we demonstrate high-fidelity ferroelectric domain switching and periodic poling of Al-polar ScAlN thin film epitaxially grown on a c-axis sapphire substrate using gallium nitride as a buffer layer. Uniform poling of ScAlN with periods ranging from 2 to 0.4 μm is realized. The ability to lithographically control the polarization of epitaxial ScAlN presents a critical advance for its further exploitation in ferroelectric storage and nonlinear optics applications.
DeepQMC: An open-source software suite for variational optimization of deep-learning molecular wave functions
Authors: Schätzle Z. , Szabó P. B. , Mezera M. , Hermann J. , Noé F.
Published: September 2023

Computing accurate yet efficient approximations to the solutions of the electronic Schrödinger equation has been a paramount challenge of computational chemistry for decades. Quantum Monte Carlo methods are a promising avenue of development as their core algorithm exhibits a number of favorable properties: it is highly parallel and scales favorably with the considered system size, with an accuracy that is limited only by the choice of the wave function Ansatz. The recently introduced machine-learned parametrizations of quantum Monte Carlo Ansätze rely on the efficiency of neural networks as universal function approximators to achieve state of the art accuracy on a variety of molecular systems. With interest in the field growing rapidly, there is a clear need for easy to use, modular, and extendable software libraries facilitating the development and adoption of this new class of methods. In this contribution, the DeepQMC program package is introduced, in an attempt to provide a common framework for future investigations by unifying many of the currently available deep-learning quantum Monte Carlo architectures. Furthermore, the manuscript provides a brief introduction to the methodology of variational quantum Monte Carlo in real space, highlights some technical challenges of optimizing neural network wave functions, and presents example black-box applications of the program package. We thereby intend to make this novel field accessible to a broader class of practitioners from both the quantum chemistry and the machine learning communities.
Estimating the nonideality of eutectic systems containing thermally unstable substances
Authors: Alhadid Ahmad , Jandl Christian , Nasrallah Sahar , Kronawitter Silva M. , Mokrushina Liudmila , Kieslich Gregor , Minceva Mirjana
Published: September 2023

Eutectic systems design requires an in-depth understanding of their solid–liquid equilibria (SLE). Modeling SLE in eutectic systems has as prerequisites, the melting properties and activity coefficients of components in the liquid phase. Thus, due to the unavailable melting properties of thermally unstable substances, it is impossible to estimate their activity coefficients from experimental SLE data and model the SLE phase diagram of their eutectic systems. Here, we evaluate the activity coefficients of thermally unstable constituents in the liquid phase, which were calculated independent of their melting properties by correlating the SLE data of their cocrystals. Differential scanning calorimetry and powder x-ray diffraction were employed to obtain the SLE phase diagram of three eutectic systems, i.e., tetramethylammonium chloride/catechol, tetraethylammonium chloride/catechol, and betaine/catechol systems, and identify the formation of nine cocrystals. The non-random, two-liquid equation was used to calculate the activity coefficients of the components in the liquid phase. The substantial negative deviation from ideality in the three studied systems indicated strong hydrogen bonding interactions in the liquid solution. Furthermore, modeling ion–ion interactions in eutectic systems containing ionic constituents is of utmost importance for understanding their nonideality.
General dispersion relations for resistive wall modes in tokamaks
Authors: Pustovitov V. D.
Published: September 2023

The dispersion relation for the resistive wall modes (RWMs) is derived without the use of the trial function bHF proposed in S. W. Haney and J. P. Freidberg [Phys. Fluids B 1, 1637 (1989)] for the magnetic perturbation b outside the plasma. Another difference from the Haney–Freidberg (HF) approach is the incorporation of non-ideal effects in the plasma description. These enter the final result through the energy functional and affect the external solution for b through the boundary conditions only. This allows to perform the derivations in a general form without constraints on the dissipation mechanisms in the plasma. Then, the main mathematical difficulties are related to the description of the energy flow outside the plasma. This part of the task is presented with details allowing easy comparisons with the reference HF case. Being universally applicable, the resulting dispersion relation covers the existing variants, including those based on the so-called kinetic approaches. It shows that, because of its integral nature, the same predictions can be expected from various models for the plasma. Another conclusion is that, with a non-ideal contribution, just one or two free parameters would be enough to get agreement with experimental data on the plasma stability boundary. This, however, does not guarantee that the same choice of the fitting coefficients will be similarly efficient on other devices. The proposed relations provide a unified approach to the problem of plasma stability against RWMs.
Phase-controlled topological plasmons in 1D graphene nanoribbon array
Authors: Xia Sheng-Xuan , Zhang Di , Zhai Xiang , Wang Ling-Ling , Wen Shuang-Chun
Published: September 2023

In this Letter, we report on the phase-controlled topological plasmons in 1D graphene nanoribbons (GNRs) based on a Su−Schrieffer−Heeger (SSH) model variant. By considering the dipole–dipole mode interactions, we first study the normal SSH model by an effective Hamiltonian and calculate the Zak phase as a topological invariant, finding that it is nontrivial (trivial) when the coupling distance is bigger (smaller) than half the period. Then, we reveal that the edge modes with fields highly localized at only one side exist in the model with nontrivial topology and shows the robustness of strong field confinement and extreme frequency stability against in-plane and out-of-plane disorders. Finally, we introduce the offset SSH model variant by vertically offsetting one of the GNR in SSH unit, which allows us to greatly engineer both the width of topological gap and the number of topological windows. The underlying physics are uncovered by defining a parameter called phase difference, which reveals that the topological edge modes appear (disappear) generally near the positions where the inter-unit coupling strength is bigger (smaller) than the intra-unit coupling strength, and, more notably, the phase difference is around even (odd) multiple numbers of π, which is much different from the normal SSH model where the topological phase is simply affected by the resonator distance. In addition to opening up a possibility to explore the fundamental physics of topologically protected graphene plasmons, this work also offers potential applications of these concepts to design graphene-based plasmon devices with immunity to structural imperfections.
A free-streamline boundary-layer model for small-amplitude oscillation regime of square cylinder under vortex-induced rotation
Authors: Luo Chensheng , Mou Ruiyong , Huang Xingrong , Huang Wei-Xi , Fang Le
Published: September 2023

Numerical studies about vortex-induced rotation (VIR) have shown that six regimes exist for the dynamics of square cylinder under VIR at small Reynolds numbers; however, theoretical explanations are still rare. Aiming at stepping a little further, we select one of these regimes, that is, small-amplitude oscillation regime, to develop an analytical model. In the present model, we expand the symmetric free streamline theory to an inviscid flow pasting an inclined plate and introduce the Blasius boundary layer theory in the calculation of viscous torque on a square cylinder. This model is supported by comparing with numerical results using the immersed boundary method. Results explain the mechanism of small-amplitude oscillation regime: the main sources of the out-of-phase torque come from the imbalanced distribution of pressure on the windward face and the asymmetric distribution of pressure and viscous force on the top/bottom face. An alternative way to determine the local flow parameters by global dynamic quantities is also proposed based on this model.
Propulsive performance and vortex dynamics of jellyfish-like propulsion with burst-and-coast strategy
Authors: Kang Linlin , Gao An-Kang , Han Fei , Cui Weicheng , Lu Xi-Yun
Published: September 2023

The propulsive performance and vortex dynamics of a two-dimensional model for the jellyfish-like propulsion with burst-and-coast strategy are investigated using a penalty-immersed boundary method. The simplified model comprises a pair of pitching flexible plates with their leading edges connected. The effects of two key parameters are considered, i.e., the duty cycle (DC, the ratio of the closing phase to the whole period) and the bending stiffness (K). Three different wake patterns, i.e., periodic symmetric, periodic asymmetric, and chaotic wakes, are identified in the DC–K plane. Numerical results indicate that a significant fast-close-slow-open motion is more likely to achieve higher speed, efficiency, and stability than a slow-close-fast-open motion, and proper higher bending stiffness is conducive to improving efficiency. A force decomposition based on the weighted integral of the second invariant of the velocity gradient tensor is performed to gain physics insight into the self-propulsive mechanism. It is found that the repulsive force induced by the strain-rate field between the body and the previous vortex pair is the main driving force of the jellyfish-like motion and that capturing the previous vortex pair during the closing phase can significantly enhance the strain rate as well as the thrust. This clarifies why the jellyfish can achieve thrust by pushing back vortex pairs. This study provides inspiration for the design and control of flexible jet propulsion devices.
Dynamical coarse-grained models of molecular liquids and their ideal and non-ideal mixtures
Authors: Tripathy Madhusmita , Klippenstein Viktor , van der Vegt Nico F. A.
Published: September 2023

Coarse-grained (CG) simulation models of condensed-phase systems can be derived with well-established methods that perform coarse-graining in space and provide an effective Hamiltonian with which some of the structural and thermodynamic properties of the underlying fine-grained (FG) reference system can be represented. Coarse-graining in time potentially provides CG models that furthermore represent dynamic properties. However, systematic efforts in this direction have so far been limited, especially for moderately coarse-grained, chemistry-specific systems with complicated conservative interactions. With the aim of representing structural, thermodynamic, and dynamic properties in CG simulations of multi-component molecular systems, we investigated a recently introduced method in which the force on a CG particle originates from conservative interactions with surrounding particles and non-Markovian dissipative interactions, the latter introduced by means of a colored-noise thermostat. We examined two different methods to derive isotropic memory kernels required for integrating the corresponding generalized Langevin equation (GLE) of motion, based on the orthogonal dynamics of the FG forces and on an iterative optimization scheme. As a proof of concept, we coarse-grain single-component molecular liquids (cyclohexane, tetrachloromethane) and ideal and non-ideal binary mixtures of cyclohexane/tetrachloromethane and ethanol/tetrachloromethane, respectively. We find that for all systems, the FG single particle velocity auto-correlation functions and, consequently, both the short time and long time diffusion coefficients can be quantitatively reproduced with the CG-GLE models. We furthermore demonstrate that the present GLE-approach leads to an improved description of the rate with which the spatial correlations decay, which is artificially accelerated in the absence of dissipation.
Suppression of vortex-induced vibration of an elastically mounted sphere by electromagnetic force
Authors: Yao Weiguang , Jia Xiaoyu , Zhang Hui , Gui Mingyue
Published: September 2023

In this paper, electromagnetic force on two degrees of freedom vortex-induced vibration (VIV) of an elastically mounted sphere for vibration suppression is numerically achieved at Re = 300. The relations between the wake structures, velocity and pressure distributions, force coefficients, and sphere displacement are investigated by varying the interaction parameter (N) of electromagnetic force. With the increase in N, the momentum of the fluid near the sphere is enhanced to control the flow separation. Therefore, both the rotation radii of the rear stagnation point (RSP) and the separation line (SL) decrease, causing the spiral vortices to become thinner. This leads to a reduction in the fluctuation amplitude of the lift coefficient and mitigates the VIV. As N exceeds 0.5, the periodic spiral vortices transform into a steady double-thread wake due to the stopping of RSP and SL rotation. Therefore, a constant lift is generated in the z-direction due to the asymmetric flow field in the x–z plane, which is accompanied by the VIV fully suppressed. Moreover, the effect of electromagnetic locations (θm) on vibration suppression is examined. With the increase of θm, the vibration suppression efficiency increases first and then decreases, which achieves the maximum vibration suppression efficiency at θm = 125°. The reason is that the electromagnetic force covers the location of the half-circle-shaped SL, which has a significant effect on the control of the flow separation.
Wave power extraction from slanted oscillating water columns in the presence of an array of arbitrary trenches
Authors: Gayathri R. , Chang Jen-Yi , Tsai Chia-Cheng
Published: September 2023

This paper investigates the impact of arbitrary bottom topography on the efficiency of a slanted oscillating water column device located in near-shore areas. The device incorporates a turbine positioned at its opening, which harnesses the oscillation of the fluid at the free surface, created by recurrent incident waves, to propel an air volume in a uni-direction. To analyze the wave power absorption capability of the system, an eigenfunction expansion and a boundary element model based on linear water wave theory are employed. The notion is to use the anticipated amplification of scattered and reflected wave fields resulting from the existence of a sloping wall to improve the wave power absorption caused by the walls' wave reflections. The accuracy of the current study's numerical results is ratified by conducting a comparative study using the available data given by other researchers. The study demonstrates that multiple efficiencies occur in the case of the long-wave region as compared to the short-wave region. Additionally, both the shape and magnitude of the efficiency curves are influenced by the slanted design of the device's front wall and the number of trenches.
Holstein polaron transport from numerically “exact” real-time quantum dynamics simulations
Authors: Janković Veljko
Published: September 2023

Numerically “exact” methods addressing the dynamics of coupled electron–phonon systems have been intensively developed. Nevertheless, the corresponding results for the electron mobility μdc are scarce, even for the one-dimensional (1d) Holstein model. Building on our recent progress on single-particle properties, here we develop the momentum-space hierarchical equations of motion (HEOM) method to evaluate real-time two-particle correlation functions of the 1d Holstein model at a finite temperature. We compute numerically “exact” dynamics of the current–current correlation function up to real times sufficiently long to capture the electron’s diffusive motion and provide reliable results for μdc in a wide range of model parameters. In contrast to the smooth ballistic-to-diffusive crossover in the weak-coupling regime, we observe a temporally limited slow-down of the electron on intermediate time scales already in the intermediate-coupling regime, which translates to a finite-frequency peak in the optical response. Our momentum-space formulation lowers the numerical effort with respect to existing HEOM-method implementations, while we remove the numerical instabilities inherent to the undamped-mode HEOM by devising an appropriate hierarchy closing scheme. Still, our HEOM remains unstable at too low temperatures, for too strong electron–phonon coupling, and for too fast phonons.
Anisotropy of fracture and permeability in high-rank coal analyzed using digital rock physics
Authors: Wang Xianglong , Pan Jienan , Hou Quanlin , Li Guofu , Liu Liangliang , Wang Zhenzhi , Zhang Lei
Published: September 2023

Rock microstructure analysis and physical property simulation by means of digital rock physics (DRP) can overcome the deficiencies such as poor quantification and visibility in traditional petrophysical experiments. The establishment of a complete set of DRP is the basis of analyzing the microstructure of unconventional oil and gas reservoirs. In this study, high-rank coal, a material with anisotropic fracture and permeability properties, was tested using x-ray computer tomography scanning to reconstruct the digital core, and the fracture direction and structural characteristics were quantified with respect to the main inertia axis and the Feret diameter, respectively. A method for calculating the fractal dimension and tortuosity based on DRP is presented, and the optimal interaction between the lattice Boltzmann method seepage simulation and DRP is identified. The results show that the average length, width, aperture, and volume of fractures in the direction of face cleat (DFC) are 1.13, 1.10, 1.11, and 1.09 times that in the direction of butt cleat (DBC), respectively, and their surface area, count, fracture porosity, fractal dimension, and tortuosity are 1.17, 1.16, 1.26, 1.04, and 1.10 times that of DBC, respectively. The permeability of DFC was found to be 3.46 times that of DBC. This study presents an effective method for determining the dominant direction of fracture structure and fluid migration that is not limited to pores and fractures in rock but can also be used to characterize the physical properties of skeletons or solid particles in other materials.
The diffraction and re-initiation behavior of detonation wave in premixed H2–O2–Ar mixture
Authors: Hu Jiehui , Cheng Jun , Zhang Bo
Published: September 2023

Previous studies have demonstrated the effective enhancement of initiation stability in the combustor of a rotating detonation engine through the use of a pre-detonator. However, when a stable detonation propagates from a small-diameter pre-detonator into a larger-diameter combustor, a brief failure occurs, followed by the re-initiation of the detonation wave. This failure is attributed to detonation diffraction as the wave passes through a sudden expansion section. This study systematically investigates the phenomenon of detonation diffraction and re-initiation through 2D numerical simulations. The effect of the diameter ratio between the pre-detonator and combustor on detonation propagation is examined by adjusting the diameter ratio D/d in the range of 1.1–2.7, where D and d represent the diameters of the larger (corresponding to the combustor) and smaller (corresponding to the pre-detonator) tubes, respectively. Various modes of detonation propagation and the corresponding evolution of the detonation wave are observed. The results reveal that as the detonation wave propagates through the sudden-expansion section, it diffracts at the corner and then rapidly decouples at the boundary. For D/d less than 1.3, the detonation wave can maintain its propagation by adjusting the structure of the cell distribution, referred to as the supercritical mode. As D/d increases, the detonation wave experiences initial failure followed by re-initiation, corresponding to the critical mode. When D/d exceeds 2.6, complete failure of detonation occurs and cannot be re-initiated, resulting in the sub-critical mode. Notably, under the critical mode, the distance LDDT required for re-initiation linearly increases with D/d (LDDT = 41.48(D/d) + 4.30). Additionally, the pressure of the triple point near the wall, formed by the convergence of the reflected shock wave, transmitted wave, and precursor shock wave, determines the possibility of local detonation initiation, which induces re-initiation in the testing tube. It is proposed that when the pressure of the triple point exceeds the theoretical pressure of post-shock (Ppost-shock), a local overdriven detonation occurs. Furthermore, when the convergent point of the transmitted shock wave propagates along the central line and passes through the flame front, local detonation can be induced as well. This study systematically illustrates the details of diffraction and re-initiation when the detonation wave passes through a sudden-expansion section.
Improvement of the electrical treeing resistance of polymers through the self-arrangement effect of the voltage stabilizer caused by dielectrophoresis under non-uniform electric field
Authors: Zhu Xiaoqian , Li Yuhang , Zhou Yuanxiang , Zhang Yunxiao , Liu Xuanhao , Chen Ming
Published: September 2023

Improving the electrical treeing resistance of polymer is of great significance for insulation reliability. To achieve this, a solution-based method is employed to introduce a voltage stabilizer with high electron affinity into the silicone rubber (SiR). Experimental findings demonstrate the voltage stabilizer's ability to improve the tree initiation voltage and provide evidence of their migration within the SiR. Additionally, by combining a finite element method, it has been confirmed that voltage stabilizers can migrate through dielectrophoresis in non-uniform electric fields and adaptively reposition themselves in response to changes in electric field distribution during the growth of the electrical tree.
Machine-learned correction to ensemble-averaged wave packet dynamics
Authors: Holtkamp Yannick , Kowalewski Markus , Jasche Jens , Kleinekathöfer Ulrich
Published: September 2023

For a detailed understanding of many processes in nature involving, for example, energy or electron transfer, the theory of open quantum systems is of key importance. For larger systems, an accurate description of the underlying quantum dynamics is still a formidable task, and, hence, approaches employing machine learning techniques have been developed to reduce the computational effort of accurate dissipative quantum dynamics. A downside of many previous machine learning methods is that they require expensive numerical training datasets for systems of the same size as the ones they will be employed on, making them unfeasible to use for larger systems where those calculations are still too expensive. In this work, we will introduce a new method that is implemented as a machine-learned correction term to the so-called Numerical Integration of Schrödinger Equation (NISE) approach. It is shown that this term can be trained on data from small systems where accurate quantum methods are still numerically feasible. Subsequently, the NISE scheme, together with the new machine-learned correction, can be used to determine the dissipative quantum dynamics for larger systems. Furthermore, we show that the newly proposed machine-learned correction outperforms a previously handcrafted one, which, however, improves the results already considerably.
Mathematical study of nanoparticle loaded in red blood cells for drug delivery in an artery with stenosis
Authors: Prasad Bhawini , Bali Rekha
Published: September 2023

Nanoparticles (NPs) offer a revolutionary platform in order to achieve targeted delivery for the treatment of cardiovascular diseases. Encapsulation of NPs or nanodrugs by the process of osmosis, inside red blood cells (RBCs), is a new technique in this regard. RBCs loaded with nanodrugs enhance the bio-availability and bio-compatibility. Mathematical model for the analysis of this RBCs loaded with NPs in blood has been developed for a catheterized artery with stenosis. The RBCs loaded with NPs in blood is described as nanofluid. The temperature and velocity of resultant nanofluid have been analyzed. Graphs have been plotted using MATLAB bvp4c for various values of particle radius and membrane thickness. It has been observed that RBCs loaded with NPs concentrate highly at the stenosis thus aid in dissolving it. Also, it has been examined that an optimum NP with a radius of 100 nm is suitable for the purpose. The outcomes shall be useful for the improvement of pharmacokinetics of nanodrugs.
Interface charge engineering on an in situ SiNx/AlGaN/GaN platform for normally off GaN MIS-HEMTs with improved breakdown performance
Authors: He JiaQi , Wen KangYao , Wang PeiRan , He MingHao , Du FangZhou , Jiang Yang , Tang ChuYing , Tao Nick , Wang Qing , Li Gang , Yu HongYu
Published: September 2023

This work adopts interface charge engineering to fabricate normally off metal–insulator–semiconductor high electron mobility transistors (MIS-HEMTs) on an in situ SiNx/AlGaN/GaN platform using an in situ O3 treatment performed in the atomic layer deposition system. The combination of in situ SiNx passivation and an O3-treated Al2O3/AlGaN gate interface allows the device to provide an excellent breakdown voltage of 1498 V at a low specific on-resistance of 2.02 mΩ cm2. The threshold voltage is increased by 2 V by significantly compensating the net polarization charges by more than five times with O3 treatment as well as reducing the interface traps and improving the high-temperature gate stability. Furthermore, a physical model of fixed charges at the Al2O3/AlGaN interface is established based on dielectric thickness-dependent linear fitting and numerical calculations. The matched device performance and simulated energy band bending elucidate the O3-treated fixed-charge modulation mechanism, providing a practical method for producing normally off GaN MIS-HEMTs.
Correlating vapour uptake with the luminescence quenching of poly(dendrimer)s for the detection of nitro group-containing explosives
Authors: Hutchinson Kinitra L. , Poliquit Beta Z. , Clulow Andrew J. , Burn Paul L. , Gentle Ian R. , Shaw Paul E.
Published: September 2023

Thin films of two poly(dendrimer)s were studied for the detection of trace quantities of nitro-based taggants and explosives. The poly(dendrimer) structures consist of side chain-conjugated triphenylamine-based dendritic chromophores attached to a non-conjugated polymer backbone. The poly(dendrimer)s differ in terms of the conjugation length, steric bulk and surface groups of the chromophores and we investigated the effects of these differences on sensing performance. We found that the addition of first-generation biphenyl-based dendrons to the chromophores of one of the polymers, P2, resulted in greater photoluminescence quenching, sensitivity and recovery to pulses of the vapours of the nitroaliphatic taggant 2,3-dimethyl-2,3-dinitrobutane (DMNB) and the nitroaromatic analyte 2,4-dinitrotoluene (2,4-DNT) compared with the other polymer, P1. We employed neutron reflectometry to characterise the vapour uptake of both poly(dendrimer)s and a structurally similar triphenylamine-based dendrimer D1 for comparison. The results show that the P2 has a mass density of 0.91 ± 0.01 v. 1.01 ± 0.01 g cm−3 for both P1 and D1 and can absorb at least twice the amount of 2,4-DNT. These results show how increasing the dendritic character of the poly(dendrimer) architecture provides a route for optimising vapour uptake and improving sensing performance in the solid state.
Microstructure characteristics and strain hardening behaviour of Ti17 linear friction welded joints
Authors: He Peng , Wu Yunxin , Zhang Tao , Wu Zhijie
Published: September 2023

This study investigated the microstructure variations in Ti17 linear friction welded joints and evaluated the effect of strain rate and post weld heat treatment on the strain hardening behaviour. The welded zone of the as-welded joints consists of equiaxed β grains, while the prior- β grains in the thermal mechanical affected zone are severely deformed. After heat treatment, fine needle-like αS precipitates dispersed in the β matrix strengthen the tensile properties. The fracture mechanism transforms from brittle to ductile. The strain hardening capacity and exponent are negatively correlated with strain rate. At higher strain rates, the strain rate sensitivity increases during the initial stage of deformation.
Sliding wear behaviour of austempered ductile iron, boron steel and AISI 1045 steel of similar hardness: Effect of microstructure, yield strength, and strain hardening
Authors: Gupta Anoop , Singh Manpreet , Batra Uma , Sharma Sandan Kumar
Published: September 2023

A study on dry sliding wear investigated four alloys: fully austenitized ADI (F-ADI), intercritically austenitized austempered ductile iron (I-ADI), hardened and tempered Boron steel (B-Steel), and hardened and tempered AISI 1045 steel (EN-Steel). Despite their similar hardness levels, these alloys differ in composition and microstructure. Testing was conducted using a Ball-On-Disc setup (ASTM G99-05) with a chrome steel ball, maintaining a constant sliding speed of 0.6 m/s and applying loads between 20 and 80 N. This study aimed to understand the influence of yield strength ( σy), strain hardening coefficient ( n), and microstructure on sliding wear under uniform hardness conditions. The findings indicated a strong connection between sliding wear resistance, strain hardening coefficient, toughness, and yield strength. Wear mechanisms varied slightly among materials; F-ADI and I-ADI exhibited deformed layers with increased hardness and oxide formation, while B-Steel and EN-Steel showed micro-cutting and micro-ploughing. F-ADI's high-carbon austenite film and I-ADI's proeutectoid ferrite contributed to improved wear performance. The hardness of the deformation layer on FADI and I-ADI's worn surfaces highlighted the benefits of strain hardening in dry sliding wear.
The RasGAP-associated endoribonuclease G3BP mediates stress granule assembly
Authors: Tourrière Hélène , Chebli Karim , Zekri Latifa , Courselaud Brice , Blanchard Jean Marie , Bertrand Edouard , Tazi Jamal
Published: September 2023

Stress granules (SGs) are formed in the cytoplasm in response to various toxic agents and are believed to play a critical role in the regulation of mRNA metabolism during stress. In SGs, mRNAs are stored in an abortive translation initiation complex that can be routed to either translation initiation or degradation. Here, we show that G3BP, a phosphorylation-dependent endoribonuclease that interacts with RasGAP, is recruited to SGs in cells exposed to arsenite. G3BP may thus determine the fate of mRNAs during cellular stress. Remarkably, SG assembly can be either dominantly induced by G3BP overexpression, or on the contrary, inhibited by expressing a central domain of G3BP. This region binds RasGAP and contains serine 149 whose dephosphorylation is induced by arsenite treatment. Critically, a non-phosphorylatable G3BP mutant (S149A) oligomerizes and assembles SG. These results suggest that G3BP is an effector of SG assembly and that Ras signaling contributes to this process by regulating G3BP dephosphorylation.
Electrothermal transport of water conveying copper, silver and alumina nanoparticles through a vertical wavy microchannel
Authors: Waheed S , Noreen S , Zahri M , Soufyane A
Published: September 2023

This study emphasizes the significance of optimizing heat transmission, energy conversion, and thermal management in electronic devices, renewable energy systems, and emerging technologies like thermoelectric devices and energy storage systems. The aim is to enhance heat transfer efficiency for improved performance and lifespan of electronic equipment. The research utilizes a mathematical flow analysis to study a water-based ternary nanofluid’s flow and thermal characteristics in a vertical microfluidic channel driven by peristalsis and electroosmosis. The ternary-hybrid nanofluid (THNF), comprising copper, silver, and alumina nanoparticles dissolved in water, is examined considering induced magnetic fields. The study delves into fluid flow, heat absorption, and mixed convection, using Debye–Hückel, lubrication, and long wavelength approximations. Results show that THNF exhibits superior heat transmission compared to pure water. Increasing solid volume fraction of nanoparticles decreases THNF’s temperature. Induced magnetic fields impact the system. This research could influence thermal pipe heat sinks and bioengineered medical devices design.