bluuebunny/crossref_metadata_2025 huggingface dataset:
A conditioned reflex action embedded associative context learning‐based energy efficient paradigm in smart city milieu
Authors: Hussain Majid , Bilal Ahmad , Faheem Muhammad , Anwar Muhammad , Zia Muhammad Sultan
Published: July 2023

An intelligent video surveillance system is crucial to enhance public safety, crime prevention, traffic, and crowd management in a smart city milieu. Situational awareness is an essential aspect of these surveillance systems and it is inferred through underlying context aware frameworks. However, these systems may not possess the ability to proactively disseminate the real‐time context among its sensor nodes. Moreover, in the specific conditions of occurrence of related or repeated events, these systems may also perform inefficiently through afresh context processing and disseminate cycles, without learning from the relevant context that has already been occurred and processed by the system. It leads to deteriorated performance, especially delay in reaction, overwhelmed processing, and energy expenditures. Therefore, to counter such issues, this research work proposes an energy efficient situational aware framework deployed in visual sensors network that is incorporated with context associative learning. System observes currently occurring context at each instance of an event. Overtime, context is refined and stored in context database. Such mechanism empowers the system to learn from previous experiences and develop relationship among the subsequent events that is embedded through this associative (adaptive) learning. Eventually, each event is processed through intelligent resource allocation, supported through mechanism of context learning that further illustrates the independent functions of reduced processing and improved (rapid) decision making resulting in evolution of energy efficient computing paradigm. Ultimately, the capability of learned reflex‐action is induced through introspectively evolved context of the system in entirety and against specific condition of recurred situation depicting minimum energy expenditure.
COVID-19 and Blood Clots: A Report of Massive Pulmonary Embolism in COVID-19 Patient Supported on Veno-Venous ECMO and the Utility of Thrombolysis
Authors: Akkanti Bindu , Zwischenberger Joseph , Warner Mark T. , Dinh Kha , Hussain Rahat , Kazzaz Farah , Kingah Pascal , Janowiak Lisa M. , Kar Biswajit , Gregoric Igor D.
Published: July 2023

COVID-19 morbidity and mortality are not equivalent to other etiologies of acute respiratory distress syndrome (ARDS) as fulminant activation of coagulation can occur, thereby resulting in widespread microvascular thrombosis and consumption of coagulation factors. A 53-year-old female presented to an emergency center on two occasions with progressive gastrointestinal and respiratory symptoms. She was diagnosed with COVID-19 pneumonia and admitted to a satellite intensive care unit with hypoxemic respiratory failure. She was intubated and mechanically ventilated, but her ARDS progressed over the next 48 hours. The patient was emergently cannulated for veno-venous extracorporeal membrane oxygenation (V-V ECMO) and transferred to our hospital. She was in profound shock requiring multiple vasopressors for hemodynamic support with worsening clinical status on arrival. On bedside echocardiography, she was found to have a massive pulmonary embolism with clot-in-transit visualized in the right atrium and right ventricular outflow tract. After a multidisciplinary discussion, systemic thrombolytic therapy was administered. The patient’s hemodynamics improved and vasopressors were discontinued. This case illustrates the utility of bedside echocardiography in shock determination, the need for continued vigilance in the systematic evaluation of unstable patients in the intensive care unit, and the use of systemic thrombolytics during V-V ECMO in a novel disease process with evolving understanding.
Colostrum et transfert d’immunité : les différents tests, leurs intérêts et limites
Authors: Belbis Guillaume
Published: July 2023

La prise rapide d’un colostrum de bonne qualité en quantité suffisante est un élément-clé de la prévention des affections du plus jeune âge. Cependant ceci n’est pas toujours réussi, et les insuffisances de transfert d’immunité passive sont encore nombreuses en pratique. De multiples méthodes diagnostiques existent pour évaluer la qualité des colostrums et/ou pour diagnostiquer ce défaut de transfert. Des méthodes quantitatives ou semi-quantitatives existent, présentant leurs avantages et inconvénients. Cet article se propose de faire une revue bibliographique de ces tests et de leurs caractéristiques.
Mettre en évidence une inflammation au chevet de l’animal
Authors: De Campos Charly
Published: July 2023

L’utilisation raisonnée des protéines de la phase aiguë de l’inflammation, du profil protéique classique (protéines totales, albumine, globulines), du leucogramme sanguin et de l’analyse des liquides péritonéal, synovial et cérébrospinal contribue à une plus grande efficacité dans le diagnostic à l’échelle individuelle et collective. Un suivi thérapeutique peut également être réalisé en dosant le fibrinogène ou en suivant la persistance de cellules immatures dans la circulation sanguine périphérique ou de la leucocytose. L’échographie est également un examen paraclinique de plus en plus utilisé, augmentant les performances diagnostiques de mise en évidence d’un syndrome inflammatoire au chevet de l’animal. Cependant, en médecine individuelle, l’interprétation de ces biomarqueurs ne peut pas être dissociée ou substituée à l’examen clinique.
Analyse du liquide ruminal en pratique : techniques, analyses, interprétations
Authors: Knapp Émilie
Published: July 2023

La santé et la capacité de digestion du rumen sont les points-clés de l’efficience alimentaire et de la durabilité des exploitations (environnement, économique et social). La dynamique et l’interaction du rumen avec l’animal et son environnement (ration, éleveur et bâtiments) sont complexes et tournées vers une recherche constante d’un équilibre et d’une certaine stabilité des conditions physico-chimiques du rumen afin d’y maintenir la vie. Les effets néfastes des dysfonctionnement du rumen sur les ­performances zootechniques ainsi que sur la santé des bovins sont bien connus. Cependant, le diagnostic de ce dysfonctionnement n’est pas toujours aisé à cause de la capacité d’adaptation variable d’une part entre les animaux et, d’autre part entre les troupeaux. Les conséquences d’un dysfonctionnement ruminal sont souvent variables et subcliniques. Le prélèvement de jus de rumen est donc un examen complémentaire intéressant dans le diagnostic complexe des pathologies métaboliques subcliniques et chroniques comme la SARA. Le protocole de prélèvement (méthode, nombre et types d’animaux) est essentiel à la réalisation d’un bon diagnostic. En exploitation, il est directement possible d’analyser macroscopiquement les échantillons, de mesurer le pH, d’observer les protozoaires au microscope ainsi que d’approcher la fonction bactérienne grâce à la mesure du potentiel redox. L’interprétation des résultats ainsi que les solutions apportées seront à remettre dans le contexte de l’exploitation.
Maternal Sex Chromosome Aneuploidy Identified through Noninvasive Prenatal Screening: Clinical Profile and Patient Experience
Authors: Roberts Aaron W. , Maisenbacher Melissa K. , Parmar Sheetal , Wilkinson Julia , Poll Sarah , Faulkner Nicole , Prakash Siddharth K.
Published: July 2023

Objective Noninvasive prenatal screening (NIPS) may incidentally identify maternal aneuploidies that have health implications. We evaluated patients' experience with counseling and follow-up diagnostic testing after NIPS flags a potential maternal sex chromosome aneuploidy (SCA).

Study Design Patients who underwent NIPS at two reference laboratories between 2012 and 2021 and had test results that were consistent with possible or probable maternal SCA were contacted with a link to an anonymous survey. Survey topics included demographics, health history, pregnancy history, counseling, and follow-up testing.

Results A total of 269 patients responded to the anonymous survey, and 83 of these individuals also completed one follow-up survey. Most received pretest counseling. A total of 80% were offered fetal genetic testing during the pregnancy, and 35% of patients completed diagnostic maternal testing. Monosomy X-related phenotypes such as short stature or hearing loss prompted follow-up testing that led to a diagnosis of monosomy X in 14 (6%) cases.

Conclusion Follow-up counseling and testing after a high-risk NIPS result suggestive of maternal SCA is heterogenous in this cohort and may be frequently incomplete. Health outcomes may be affected by these results and additional research could improve the provision, delivery, and quality of posttest counseling.

Key Points
Rhinoplasty in Patients with Cleft Lip Nasal Deformity: Correcting the Alar Base
Authors: DeVictor Samuel R. , Tollefson Travis T.
Published: July 2023

The characteristic cleft nasal deformity presents several challenges for the rhinoplasty surgeon attempting to provide the optimal nasal function and appearance for their patient. One of the difficulties with cleft rhinoplasty is how best to address the malposition alar base. The purpose of this review is to evaluate the various surgical approaches and techniques for properly repositioning the alar base for cleft patients. Outcomes are ultimately dependent on individual patient factors, anatomy, surgical technique, and surgeon experience. Below, we will review the variety of techniques used, the evidence supporting certain techniques, and our preferences.
Rhinoplasty: Considerations for Patients with Facial Paralysis
Authors: Shukla Aishwarya , Lu G. Nina
Published: July 2023

Nasal obstruction is a common sequela of flaccid facial paralysis but one that is often underaddressed surgically. Weakness of nasal musculature on the paralyzed side of the face leads to nasal valve narrowing through loss of static and dynamic nasal side wall tone as well as inferomedial displacement of the alar base. Standard rhinoplasty techniques such as alar batten grafts or flaring sutures may be used to support the nasal side wall in facial paralysis. However, to address the inferomedial alar displacement, suspension techniques are often required. Suture resuspension and fascia lata resuspension techniques are described, with modifications to each to improve longevity of the suspension.
Spatial gradients of urban land density and nighttime light intensity in 30 global megacities
Authors: Zheng Muchen , Huang Wenli , Xu Gang , Li Xi , Jiao Limin
Published: July 2023

The spatial agglomeration of urban elements results in the center-periphery urban structure, but the difference in spatial gradients of socioeconomic and physical elements is unclear. This study investigates how urban land density (ULD) and nighttime light intensity (NLI) decline with the distance to center(s) using the inverse-S function. Taking 30 global megacities as examples, we acquired their urban land and nighttime light in 2020 to represent urban physical and socioeconomic elements, respectively. ULD and NLI in concentric rings have been calculated to compare their spatial gradients from the city center(s). Results show that both ULD and NLI decrease slowly around city centers, followed by a relatively quick decline to suburban areas, and then decrease slowly again to a background level, showing an inverse-S shape. This spatial gradient can be well-fitted by the inverse-S function, whose parameters reflect disparities in urban extents and urban forms. NLI decreases faster than ULD, resulting in smaller radii (extents) of NLI, which shows the spatial agglomeration of socioeconomic elements is more obvious than that of physical space. This gap requires balanced development of socioeconomic and physical elements in megacities to avoid low-density urban sprawl and promote sustainable urban development.
Toward a general neural network force field for protein simulations: Refining the intramolecular interaction in protein
Authors: Zhang Pan , Yang Weitao
Published: July 2023

Molecular dynamics (MD) is an extremely powerful, highly effective, and widely used approach to understanding the nature of chemical processes in atomic details for proteins. The accuracy of results from MD simulations is highly dependent on force fields. Currently, molecular mechanical (MM) force fields are mainly utilized in MD simulations because of their low computational cost. Quantum mechanical (QM) calculation has high accuracy, but it is exceedingly time consuming for protein simulations. Machine learning (ML) provides the capability for generating accurate potential at the QM level without increasing much computational effort for specific systems that can be studied at the QM level. However, the construction of general machine learned force fields, needed for broad applications and large and complex systems, is still challenging. Here, general and transferable neural network (NN) force fields based on CHARMM force fields, named CHARMM-NN, are constructed for proteins by training NN models on 27 fragments partitioned from the residue-based systematic molecular fragmentation (rSMF) method. The NN for each fragment is based on atom types and uses new input features that are similar to MM inputs, including bonds, angles, dihedrals, and non-bonded terms, which enhance the compatibility of CHARMM-NN to MM MD and enable the implementation of CHARMM-NN force fields in different MD programs. While the main part of the energy of the protein is based on rSMF and NN, the nonbonded interactions between the fragments and with water are taken from the CHARMM force field through mechanical embedding. The validations of the method for dipeptides on geometric data, relative potential energies, and structural reorganization energies demonstrate that the CHARMM-NN local minima on the potential energy surface are very accurate approximations to QM, showing the success of CHARMM-NN for bonded interactions. However, the MD simulations on peptides and proteins indicate that more accurate methods to represent protein–water interactions in fragments and non-bonded interactions between fragments should be considered in the future improvement of CHARMM-NN, which can increase the accuracy of approximation beyond the current mechanical embedding QM/MM level.
Super-resolution electron ptychography of low dimensional materials at 30 keV: Beyond the detector limit
Authors: Allen C. S. , Danaie M. , Warner J. H. , Batey D. J. , Kirkland A. I.
Published: July 2023

We demonstrate that electron ptychographic phase reconstruction can recover spatial frequencies higher than those directly recorded in the experimental electron diffraction patterns. This ability to recover high angle information from the oversampled low angle information allows an annular detector to be inserted which partially shadows a lower pixelated detector to simultaneously record a conventional annular dark field image and a ptychographic dataset. We apply this approach to 30 keV imaging of monolayer molybdenum disulfide and achieve an Abbe limited resolution of 1.2 ± 0.1Å in our reconstructions.
The inflation hierarchy and the polarization hierarchy are complete for the quantum bilocal scenario
Authors: Ligthart Laurens T. , Gross David
Published: July 2023

It is a fundamental but difficult problem to characterize the set of correlations that can be obtained by performing measurements on quantum mechanical systems. The problem is particularly challenging when the preparation procedure for quantum states is assumed to comply with a given causal structure. Recently, a first completeness result for this quantum causal compatibility problem has been given based on the so-called quantum inflation technique. However, completeness was achieved by imposing additional technical constraints, such as an upper bound on the Schmidt rank of the observables. Here, we show that these complications are unnecessary in the quantum bilocal scenario, a much-studied abstract model of entanglement swapping experiments. We prove that the quantum inflation hierarchy is complete for the bilocal scenario in the commuting observable model of locality. We also give a bilocal version of an observation by Tsirelson, namely, in finite dimensions, the commuting observable model and the tensor product model of locality coincide. These results answer questions recently posed by Renou and Xu [arXiv:2210.09065v2 (2022)]. Finally, we point out that our techniques can be interpreted more generally as giving rise to a semidefinite programming hierarchy that is complete for the problem of optimizing polynomial functions in the states of operator algebras defined by generators and relations. The completeness of this polarization hierarchy follows from a quantum de Finetti theorem for states on maximal C*-tensor products.
Boundary effects on topological characteristics of urban road networks
Authors: Cheng Zekai , Ouyang Min , Du Chongyang , Zhang Hui , Wang Naiyu , Hong Liu
Published: July 2023

Urban road networks (URNs), as simplified views and important components of cities, have different structures, resulting in varying levels of transport efficiency, accessibility, resilience, and many socio-economic indicators. Thus, topological characteristics of URNs have received great attention in the literature, while existing studies have used various boundaries to extract URNs for analysis. This naturally leads to the question of whether topological patterns concluded using small-size boundaries keep consistent with those uncovered using commonly adopted administrative boundaries or daily travel range-based boundaries. This paper conducts a large-scale empirical analysis to reveal the boundary effects on 22 topological metrics of URNs across 363 cities in mainland China. Statistical results show that boundaries have negligible effects on the average node degree, edge density, orientation entropy of road segments, and the eccentricity for the shortest or fastest routes, while other metrics including the clustering coefficient, proportion of high-level road segments, and average edge length together with route-related metrics such as average angular deviation show significant differences between road networks extracted using different boundaries. In addition, the high-centrality components identified using varied boundaries show significant differences in terms of their locations, with only 21%–28% of high-centrality nodes overlapping between the road networks extracted using administrative and daily travel range-based boundaries. These findings provide useful insights to assist urban planning and better predict the influence of a road network structure on the movement of people and the flow of socio-economic activities, particularly in the context of rapid urbanization and the ever-increasing sprawl of road networks.
Giant spin-splitting and tunable spin-momentum locked transport in room temperature collinear antiferromagnetic semimetallic CrO monolayer
Authors: Chen Xin , Wang Duo , Li Linyang , Sanyal Biplab
Published: July 2023

In this work, we present theoretical predictions of a two-dimensional collinear antiferromagnetic semimetal, CrO, which exhibits a giant spin-split band structure, spin-momentum locked transport properties, and a high Néel temperature. Specifically, CrO features two pairs of spin-polarized anisotropic Weyl points at the Fermi level. By manipulating the position of these Weyl points with strain, we demonstrate that four different antiferromagnetic spintronic states with zero net magnetic moments can be achieved, including semimetals with two spin-polarized transport channels, half-semimetals, semiconductors with two spin-polarized transport channels, and half-semiconductors. The strain-induced semiconducting state also preserves the ultra-high carrier mobility of Weyl points, and the bandgap can be easily tuned. These findings offer a good avenue in spintronics without net magnetic moment or strong spin–orbit coupling and could lead to the development of antiferromagnetic materials for spintronic applications.
Quantitative uranium elemental reconstruction using spectral x-ray radiography
Authors: Gilbert Andrew J. , McDonald Benjamin S. , Kasparek Dustin M. , Wittman Richard S. , Gillis Wesley C. , Clark Richard A. , Brayfindley Eva , Sweet Lucas E.
Published: July 2023

X-ray radiography offers the ability to noninvasively inspect the internal structure and material composition of objects. Dual-energy radiography allows material discrimination but is limited in quantitative material measurements due to the broad nature of the interrogating x-ray spectrum. Spectral radiography detectors provide an observation of not just the number of x rays that are transmitted through a sample but also the spectrum. Here, experimental validations of a method to use spectral x-ray radiography to accurately quantify the uranium mass in a powder are presented. An accurate system response model was developed, which includes a model of the incident x-ray source spectrum and a pixel-wise detector response that describes how the transmitted x rays were observed. Further, a calibration to account for the effect of partial x-ray attenuation was developed. The method is demonstrated to be capable of estimating the uranium mass in a variety of uranium oxide powders to a bias of −0.01±0.62%.
Sensitivity comparison of two-photon vs three-photon Rydberg electrometry
Authors: Prajapati Nikunjkumar , Bhusal Narayan , Rotunno Andrew P. , Berweger Samuel , Simons Matthew T. , Artusio-Glimpse Alexandra B. , Ju Wang Ying , Bottomley Eric , Fan Haoquan , Holloway Christopher L.
Published: July 2023

We investigate the sensitivity of co-linear three-photon electromagnetically induced transparency (EIT) in 133Cs Rydberg atoms to radio frequency electric fields and compare against the conventional two-photon system. Specifically, we model the 4-level and 5-level atomic systems and compare how the transmission of the probe changes with different laser powers and RF field strengths. In this model, we define a sensitivity metric that relates to the current best experimental implementation and assumes photon shot noise limited detection. We find that the three-photon system boasts much narrower linewidths compared to the conventional two-photon EIT. These narrow line features, however, do not align with the regions of the best sensitivity. In addition to this, we calculate the expected sensitivity for the two-photon Rydberg sensor and find that the best achievable sensitivity is over an order of magnitude better than the current measured values of 5 μVm−1Hz−1/2. However, by accounting for additional noise sources in the experiment and the quantum efficiency of the photo-detectors, the values are in good agreement.
Reinforcement learning based hybrid bond-order coarse-grained interatomic potentials for exploring mesoscale aggregation in liquid–liquid mixtures
Authors: Chandra Anirban , Loeffler Troy , Chan Henry , Wang Xiaoyu , Stephenson G. B. , Servis Michael J. , Sankaranarayanan Subramanian K. R. S.
Published: July 2023

Exploring mesoscopic physical phenomena has always been a challenge for brute-force all-atom molecular dynamics simulations. Although recent advances in computing hardware have improved the accessible length scales, reaching mesoscopic timescales is still a significant bottleneck. Coarse-graining of all-atom models allows robust investigation of mesoscale physics with a reduced spatial and temporal resolution but preserves desired structural features of molecules, unlike continuum-based methods. Here, we present a hybrid bond-order coarse-grained forcefield (HyCG) for modeling mesoscale aggregation phenomena in liquid–liquid mixtures. The intuitive hybrid functional form of the potential offers interpretability to our model, unlike many machine learning based interatomic potentials. We parameterize the potential with the continuous action Monte Carlo Tree Search (cMCTS) algorithm, a reinforcement learning (RL) based global optimizing scheme, using training data from all-atom simulations. The resulting RL-HyCG correctly describes mesoscale critical fluctuations in binary liquid–liquid extraction systems. cMCTS, the RL algorithm, accurately captures the mean behavior of various geometrical properties of the molecule of interest, which were excluded from the training set. The developed potential model along with the RL-based training workflow could be applied to explore a variety of other mesoscale physical phenomena that are typically inaccessible to all-atom molecular dynamics simulations.
MgF2 as an interlayer to enhance the stability of thermally activated delayed fluorescence based organic electroluminescence devices
Authors: Gaur Nrita , Banappanavar Gangadhar S. , Kabra Dinesh
Published: July 2023

Stability is one of the major challenges in organic semiconductor based optoelectronic devices. A comparative study of thermally activated delayed fluorescence (TADF) based organic light emitting diodes (OLEDs) with alkali-halide lithium fluoride (LiF) vs alkaline halide magnesium fluoride (MgF2) inorganic electron injection interlayers is presented. A TADF emitter 4CzIPN doped in CBP is used as an active layer (thickness = 15 nm @6wt. % doping) in an OLED structure: Glass/ITO/PEDOT:PSS/NPD/CBP/CBP:4CzIPN/TPBi/interlayer/Al. Prior to this comparative study, a separate exercise is carried out to obtain an optimal thickness of an MgF2 interlayer on the basis of leakage current and efficiency in the TADF-OLEDs. OLEDs with an LiF interlayer showed an external quantum efficiency (EQE) of 19.7% in comparison with an MgF2 interlayer-based OLED showed slightly lower average EQE ∼19.1% at a luminance level of 100 cd/m2; these efficiency numbers are averaged over ∼60 OLEDs. These slight changes in EQE are supported by the relative photoluminescence quantum yield measurements with a whole device stack. However, alkaline halide MgF2 based TADF-OLEDs showed approximately seven-fold enhancement in the stability (LT60) under identical operating conditions. In situ photoluminescence monitoring of operational TADF-OLEDs confirmed that the probable cause of reduced lifetime is degradation of an LiF/TPBi interface.
Flexible and low-voltage ITO synaptic transistors for biotic tactile sensing
Authors: Zhang Gengming , Yu Haoran , Shi Yiming , Liu Wanrong , Shi Xiaofang , Jin Chenxing , Xu Yunchao , Li Zhuan , Huang Shicheng , Sun Jia , Yang Junliang
Published: July 2023

Artificial intelligence technology has fueled the requirement for flexible hardware. Although flexible electronic devices have become promising candidates in recent years, they inevitably face problems like performance degradation caused by deformation. In this paper, we report a stable performance and flexible indium tin oxide synaptic transistor with an ultralow back-sweep subthreshold swing of 28.52 mV/dec, which is ascribed to the positive charge trapping/de-trapping effect introduced by a naturally oxidized Al2O3 layer. Even after bending 1 × 103 times, the flexible artificial synapse shows stable electrical performance without evident attenuation. Furthermore, the synaptic transistor exhibits good compatibility with an external thin-film pressure sensor, and their combination empowers the device to realize tactile sensing, which can achieve the function of Braille code recognition. Evidently, the reported flexible synaptic transistor demonstrates its potential for artificial perception processing.
Analysis of photon trajectories from diffusing single molecules
Authors: Gopich Irina V. , Kim Jae-Yeol , Chung Hoi Sung
Published: July 2023

In single-molecule free diffusion experiments, molecules spend most of the time outside a laser spot and generate bursts of photons when they diffuse through the focal spot. Only these bursts contain meaningful information and, therefore, are selected using physically reasonable criteria. The analysis of the bursts must take into account the precise way they were chosen. We present new methods that allow one to accurately determine the brightness and diffusivity of individual molecule species from the photon arrival times of selected bursts. We derive analytical expressions for the distribution of inter-photon times (with and without burst selection), the distribution of the number of photons in a burst, and the distribution of photons in a burst with recorded arrival times. The theory accurately treats the bias introduced due to the burst selection criteria. We use a Maximum Likelihood (ML) method to find the molecule’s photon count rate and diffusion coefficient from three kinds of data, i.e., the bursts of photons with recorded arrival times (burstML), inter-photon times in bursts (iptML), and the numbers of photon counts in a burst (pcML). The performance of these new methods is tested on simulated photon trajectories and on an experimental system, the fluorophore Atto 488.
Skipping under water: Buoyant sphere hydrodynamics at the air–water interface
Authors: Kamoliddinov Farrukh , Vakarelski Ivan U. , Thoroddsen Sigurdur T. , Truscott Tadd T.
Published: July 2023

We present an experimental study of the hydrodynamics of a buoyant sphere accelerated horizontally along an air–water interface. At low speeds, the sphere floats at the surface, while at higher speeds, the sphere starts oscillating, moving below and toward the free surface akin to underwater skipping. The sphere often breaches and forms an air cavity during its subsequent dive. These underwater air cavities become horizontal and are attached to the sphere surface near the laminar flow separation point (∼π/2). High-speed imaging is used to investigate the effects of changing the pulling angle and counterweight-induced velocity on the hydrodynamics. We examine the transition from underwater skipping oscillations to water exit, particularly above the critical Froude number of 1.2, where buoyant spheres experience complex fluid–solid interactions revealing the influence of the air cavity on drag and lift coefficients and overall sphere hydrodynamics. Finally, we analyze the novel phenomenon of the steady motion of the horizontally pulled sphere with an attached inverted-wing-shaped air cavity.
Marangoni instability in oblate droplets suspended on a circular frame
Authors: Shishkin M. A. , Kolegov K. S. , Pikin S. A. , Ostrovskii B. I. , Pikina E. S.
Published: July 2023

We study theoretically internal flows in a small oblate droplet suspended on the circular frame. Marangoni convection arises due to a vertical temperature gradient across the drop and is driven by the surface tension variations at the free drop interface. Using the analytical basis for the solutions of Stokes equation in coordinates of oblate spheroid, we have derived the linearly independent stationary solutions for Marangoni convection in terms of Stokes stream functions. The numerical simulations of the thermocapillary motion in the drops are used to study the onset of the stationary regime. Both analytical and numerical calculations predict the axially symmetric circulatory convection motion in the drop, the dynamics of which is determined by the magnitude of the temperature gradient across the drop. The analytical solutions for the critical temperature distribution and velocity fields are obtained for the large temperature gradients across the oblate drop. These solutions reveal the lateral separation of the critical and stationary motions within the drops. The critical vortices are localized near the central part of a drop, while the intensive stationary flow is located closer to its butt end. A crossover to the limit of the plane film is studied within the formalism of the stream functions by reducing the droplet ellipticity ratio to zero value. The initial stationary regime for the strongly oblate drops becomes unstable relative to the many-vortex perturbations in analogy with the plane fluid films with free boundaries.
Inversion in binary gas mixtures in rarefied flow conditions: Direct simulation Monte Carlo solution and comparison with the analytical solutions at free molecular regime
Authors: Sabouri Moslem , Roohi Ehsan
Published: July 2023

This paper analyzes the mixing of gases in a plane channel at rarefied conditions. The direct simulation Monte Carlo method is employed to simulate gas mixing in parallel mixers working at different Knudsen numbers and having different values of wall accommodation coefficient. Results show that the normal-to-wall component of the mole fraction gradient may have the same sign as the corresponding component of the diffusive mass flux vector near the diffuse solid walls in contrast to the predictions of Fick's law for continuum conditions. This non-continuum behavior, which is called “inversion” in the present study, will become more pronounced at higher Knudsen numbers, whereas it will become less evident for smaller wall accommodation coefficients. To confirm that the observed phenomenon is consistent with the basic physical laws governing the rarefied gas dynamics and it is not an artifact of the numerical method, a new analytical model based on the kinetic theory of gases is developed for the parallel mixers that have diffuse walls and are working in the free-molecular regime. Excellent agreement is observed between the analytical and direct simulation Monte Carlo results in the free molecular flow regime. Both methods predict the occurrence of inversion near the diffuse walls at highly rarefied flow conditions.
Rotational circular dichroism of diamagnetic and paramagnetic molecules. A computational study
Authors: Zdráhala Jiří , Bouř Petr
Published: July 2023

Rotational circular dichroism (RCD) has not been observed yet, but it is expected to deliver information about chiral molecules useful in many branches of chemistry. In the past, rather weak RCD intensities were predicted for model diamagnetic molecules and a limited number of rotational transitions. Here, we review quantum-mechanical foundations and simulate entire spectral profiles, including larger molecules, open-shell molecular radicals, and high-momentum rotational bands. Contribution of the electric quadrupolar moment was considered, but it turned out that it does not contribute to field-free RCD. Two conformers of a model dipeptide provided clearly distinct spectra. The dissymmetry Kuhn parameter gK predicted for the diamagnetic molecules even for high-J transitions rarely exceeded 10−5, and the simulated RCD spectra were often biased to one sign. In the radicals, the coupling of the rotational angular momentum with the spin for some transitions raised gK to about 10−2, and the RCD pattern was more conservative. In the resultant spectra, many transitions had negligible intensities due to small populations of the involved states, and a convolution with a spectral function made the typical RCD/absorption ratios about 100-times smaller (gK ∼ 10−4). This is still comparable with values typical for electronic or vibrational circular dichroism, and paramagnetic RCD is thus likely to be measurable relatively easily.
2D/2D Mo0.74W0.26S2/Ti3C2 MXene for microwave absorption with broad effective absorption band
Authors: Kong X. T. , Zhang L. , Li H. , Zhu X. B.
Published: July 2023

Transition metal dichalcogenide MoS2 is considered as a type of dielectric loss dominated electromagnetic wave absorbing material owing to the high specific surface area, layered structure, and lightweight. Introduction of interfaces will improve the electromagnetic wave absorbing performance. Here, the phase engineering of MoS2 is realized through W doping since of the microstrain effect, resulting in the appearance of 2H/1T MoS2 phase interface. Furthermore, MoS2/Ti3C2 MXene interface is realized through the construction of MoS2/Ti3C2 MXene heterostructure, leading to obvious improvements in electromagnetic wave absorbing. Because of the simultaneous introduction of 2H/1T MoS2 phase interface and the MoS2/Ti3C2 MXene interface, the microwave reflection loss can reach −45.2 dB with broad effective absorption bandwidth (<−10 dB) of 7.1 GHz (7.8–14.9 GHz) at the same thickness of 3 mm. The results shed light on enhancing electromagnetic wave absorbing performance by phase engineering as well as construction of two dimensional material/two dimensional material heterostructures, thereby introducing multiple interfaces.
Optimization of painting efficiency applying unique techniques of high-voltage conductors and nitrotherm spray: Developing deep learning models using computational fluid dynamics dataset
Authors: Pendar Mohammad-Reza , Cândido Sílvio , Páscoa José Carlos
Published: July 2023

The impetus of the current three-dimensional Eulerian–Lagrangian work is to analyze the impact of simultaneously using the inventive high-voltage conductors and Nitrotherm spraying technique for maximizing the industrial painting process efficiency. This investigation employs high-fidelity computational fluid dynamics (CFD) results in deep learning models as an input dataset. The novel conductors are called high-voltage retractable blades (HVRB) and high-voltage adjustable control-ring (HVACR) mounted on the head of the electrostatic rotating bell sprayer. The influence of dominant operational parameters, such as temperature and velocity of injected nitrogen or air, droplets' electric charge values, and their size ranges, and electric field density are examined in the considered database for the Nitrotherm spraying methodology. This broad range of parametric investigation illustrates that the inclusion of shaping nitrogen flow, manipulated electric field density, and droplet charging weights significantly affect the spraying deposition rate. The pressurized clean heated nitrogen flow, which is injected from the nozzles of the atomizers, positively redirects and harmonizes the charged droplets that construct an optimized spray plume pattern with a smaller diameter. Using innovative HVRB and HVACR conductors is manipulated the electric fields and leads to denser distribution, intensifying the acting electric force on the droplets, resulting in higher spraying transfer efficiency (TE) and thicker film formation. Based on the results, employing the introduced conductors in combination with the heated nitrogen instead of air leads to higher TE, rare overspray occurrence, formation of an esthetic paint film, lower paint consumption, and application time. Also, the collected complete database is employed for machine learning investigation to predict flow with high accuracy, aiming to reduce computational time/cost. A convolutional auto-encoder is used to reduce the computational cost with just 10% of the initial CFD computations, with a mean error of 1% on the prediction of the deposited droplet areas of the spray. The analysis revealed that by employing recurrent convolutional layers, superior capturing of the input pattern is obtained, which significantly aids the final prediction.
Effect of the spin–orbit interaction in nanotubes
Authors: Büsser C. A.
Published: July 2023

In this work, we study the electronic properties of nanotubes with spin–orbit interaction that exhibit a spin Hall effect. Nanoribbons made of these materials are expected to have topologically protected states. The lack of edge states in a seamless tube eliminates the possibility of finding a topological edge state. The spin–orbit interaction breaks the degeneracy of Dirac’s cones and eliminates the chance of finding a metal nanotube. As a consequence, this makes all nanotubes with spin–orbit interaction trivial band insulators. We focus our attention on two features. First, we study the energy band gap as a function of the diameter of the nanotubes. Then, we concentrate on controlling the bandgap of a nanotube by applying an external radial electric field. Finally, we discuss the possibility of using one of these tubes as a field-effect transistor.
Multimode Brownian oscillators: Exact solutions to heat transport
Authors: Tong Xin-Hai , Gong Hong , Wang Yao , Xu Rui-Xue , Yan YiJing
Published: July 2023

In this work, we investigate the multimode Brownian oscillators in nonequilibrium scenarios with multiple reservoirs at different temperatures. For this purpose, an algebraic method is proposed. This approach gives the exact time-local equation of motion for the reduced density operator, from which we can easily extract not only the reduced system but also hybrid bath dynamical information. The resulting steady-state heat current is found to be numerically consistent with another discrete imaginary-frequency method followed by Meir–Wingreen’s formula. It is anticipated that the development in this work would constitute an indispensable component of nonequilibrium statistical mechanics for open quantum systems.
Dynamics of single-base editing: Theoretical analysis
Authors: Vardanyan Vardan Hoviki , Wang Qian , Kolomeisky Anatoly B.
Published: July 2023

Recent experimental advances led to the development of DNA base editors (BEs) with single-nucleotide precision, which is critical for future progress in various scientific and technological fields. The molecular mechanisms of single-base discrimination, however, remain poorly understood. Using a recently developed stochastic approach, we theoretically investigated the dynamics of single-base editing. More specifically, transient and mean times to edit “TC” motifs by cytosine BEs are explicitly evaluated for correct (target) and incorrect (bystander) locations on DNA. In addition, the effect of mutations on the dynamics of the single-base edition is also analyzed. It is found that for most ranges of parameters, it is possible to temporarily separate target and bystander products of base editing, supporting the idea of dynamic selectivity as a method of improving the precision of single-base editing. We conclude that to improve the efficiency of single-base editing, selecting the probability or selecting the time requires different strategies. Physical–chemical arguments to explain the observed dynamic properties are presented. The theoretical analysis clarifies some important aspects of the molecular mechanisms of selective base editing.
Deciphering the dynamics of distorted turbulent flows: Lagrangian particle tracking and chaos prediction through transformer-based deep learning models
Authors: Hassanian R. , Myneni H. , Helgadóttir Á. , Riedel M.
Published: July 2023

Turbulent flow is a complex and vital phenomenon in fluid dynamics, as it is the most common type of flow in both natural and artificial systems. Traditional methods of studying turbulent flow, such as computational fluid dynamics and experiments, have limitations such as high computational costs, experiment costs, and restricted problem scales and sizes. Recently, artificial intelligence has provided a new avenue for examining turbulent flow, which can help improve our understanding of its flow features and physics in various applications. Strained turbulent flow, which occurs in the presence of gravity in situations such as combustion chambers and shear flow, is one such case. This study proposes a novel data-driven transformer model to predict the velocity field of turbulent flow, building on the success of this deep sequential learning technique in areas such as language translation and music. The present study applied this model to experimental work by Hassanian et al., who studied distorted turbulent flow with a specific range of Taylor microscale Reynolds numbers 100<Reλ<120. The flow underwent a vertical mean strain rate of 8 s−1 in the presence of gravity. The Lagrangian particle tracking technique recorded every tracer particle's velocity field and displacement. Using this dataset, the transformer model was trained with different ratios of data and used to predict the velocity of the following period. The model's predictions significantly matched the experimental test data, with a mean absolute error of 0.002–0.003 and an R2 score of 0.98. Furthermore, the model demonstrated its ability to maintain high predictive performance with less training data, showcasing its potential to predict future turbulent flow velocity with fewer computational resources. To assess the model, it has been compared to the long short-term memory and gated recurrent units model. High-performance computing machines, such as JUWELS-DevelBOOSTER at the Juelich Supercomputing Center, were used to train and run the model for inference.
Photo-induced oxygen vacancy formation and anomalous photoconductivity in solution-processed CoFe2O4 thin films
Authors: Garg Parul , Bera Ashok
Published: July 2023

Designing an optoelectronic device requires adequate information about the photo-response of the active material. Here, we have studied the optical and optoelectrical properties of the solution-processed inverse spinel structured CoFe2O4 (CFO) thin film and correlated it with the photovoltaic performance of CFO active material-based all-oxide solar cell. The optical absorption spectra of spin-coated CFO films show the existence of a direct bandgap of 2.64 eV with a maximum absorption coefficient >105/cm. A simple spin-coated CFO/TiO2p–n heterojunction shows an open circuit voltage of over 0.95 V under 1 sun illumination. However, photo-induced oxygen vacancy formation and the desorption of surface oxygen lead to additional electron generation and hole capture, respectively, in the p-type CFO, resulting in an anomalous photocurrent decay under white light illumination, resulting in a low short-circuit current density. This study provides a fundamental understanding of photo-carrier dynamics in solution-processed CFO thin films and apprehends the photophysics of designing spinel-ferrite-based optoelectronic devices.
Enhanced energy storage performance of (Pb, La)(Zr, Ti)O3/SrTiO3 multilayer films via a synergistic strategy
Authors: Ma Xia , Chen Bingyi , Wei Xianhua
Published: July 2023

Dielectric film capacitors possess a larger dielectric breakdown field than that of their bulk ceramic counterparts, thus showing a better energy density. Herein, a synergistic strategy has been employed to enhance the energy storage density of (Pb, La)(Zr, Ti)O3/SrTiO3 multilayer films through combing the effects of atomic doping, heat treatment, and multilayer stacking. La partially substituting Pb improves relaxor characteristics of Pb(Zr, Ti)O3. A dense amorphous microstructure results in a relatively high breakdown electric field at a low annealing temperature. Additionally, the insertion of dielectric layer SrTiO3 into (Pb, La)(Zr, Ti)O3 suppresses the carriers transport due to the interface role and further improves the insulating strength and breakdown strength. Thus, a high recoverable energy density of 67.1 J/cm3 is achieved at an ultrahigh breakdown electric field of 7.45 MV/cm. Such a synergistic multiscale approach in this work is universally effective to improve the energy storage performance of dielectric multilayer films.