bluuebunny/crossref_metadata_2025 huggingface dataset:
How would you like your proximal femoral nail – with a monocortical recon plate, with cable, or neat? A functional and radiological study of reverse oblique (AO/OTA 31-A3) intertrochanteric femur fractures
Authors: Abul Mehmet Süleyman , Metin Aytunç , Sevim Ömer Faruk , Hekim Ömer , Eceviz Engin
Published: December 2024

Objective: Intertrochanteric femur fractures (ITFF), more so reverse oblique fractures (AO/OTA 31-A3), are the most challenging clinically, with significant morbidity and mortality. Early stable fixation should be achieved to allow early mobilization and reduce complications. This study evaluates the functional and radiological outcomes of three Proximal Femoral Nail (PFN) techniques – PFN alone, Cable + PFN, and Monocortical reconstruction plate (MRP) + PFN– in managing reverse oblique ITFF, to determine the most ideal of them. Methods: A retrospective analysis was performed on 106 patients treated from 2015 to 2022. The patients were classified by the surgical intervention: Cable + PFN (n = 37), MRP + PFN (n = 29), and PFN (n = 40). The critical parameters analyzed included healing time, quality of reduction, rates of complications, and functional outcomes of Trendelenburg gait. Results: The bone healing time was significantly faster in the Cable + PFN group and MRP + PFN group as compared to the PFN group, 4.43 ± 0.92 and 4.44 ± 0.90 months versus 6.40 ± 2.41 months, respectively (p < 0.001). Compared with the PFN group, the number of cases with Trendelenburg gait in the Cable + PFN group was significantly lower, 10.8%. The number of patients showing the Trendelenburg gait trended lower in the MRP + PFN group but was insignificant (p = 0.075). Radiological outcomes did not differ significantly among the groups. Conclusion: The use of Cable + PFN and MRP + PFN techniques has superior outcomes with earlier bone union and far less incidence of Trendelenburg gait than PFN alone. These findings can help hint that perhaps the usage of cables and recon plates enhances the stability and functional restoration in patients who have sustained reverse oblique ITFF.

Level of evidence: III
Harnstoffzyklusstörungen
Authors: Posset Roland , Zielonka Matthias
Published: December 2024

Harnstoffzyklusstörungen gehören zu einer Gruppe seltener angeborener Stoffwechselerkrankungen des Intermediärmetabolismus. Abgesehen vom Ornithin Transcarbamylase-Mangel, der X-chromosomal vererbt wird, werden die weiteren Harnstoffzyklusstörungen autosomal rezessiv vererbt und zeichnen sich durch eine kumulative Inzidenz von etwa 1:35 000 Individuen im deutschsprachigen Raum (Deutschland, Österreich, Schweiz) aus. Harnstoffzyklusstörungen sind (bisher) kein Bestandteil des regulären Neugeborenenscreenings in Deutschland und werden daher in der Mehrzahl der Fälle im Neugeborenenalter durch selektive Diagnostik im Rahmen einer hyperammonämischen Entgleisung identifiziert, selten jedoch auch durch einen vorbekannten Indexpatienten und in dem Rahmen durch eine prä- oder postnatale zügige Abklärung. Typischerweise zeigen die Neugeborenen nach einem unauffälligen Schwangerschaftsverlauf und einem postnatalen symptomfreien Intervall von Stunden bis wenigen Tagen ein verheerendes Krankheitsbild mit Trinkschwäche, Lethargie, zerebralen Krampfanfällen sowie Symptomen, die einer Sepsis ähneln. Neben dieser schweren Präsentation können sich Individuen mit Harnstoffzyklusstörungen jedoch auch mit einem attenuierten Phänotyp und variablen klinischen Symptomen zu jedem Zeitpunkt jenseits der Neugeborenenperiode präsentieren. Aufgrund des heterogenen phänotypischen Bildes ist die Kenntnis für Pädiater, Stoffwechselmediziner, Kinder-/Neurologen, Gastroenterologen, Psychiater sowie Gynäkologen von Bedeutung, sodass der nachfolgende Artikel eine fokussierte Zusammenfassung der relevanten klinischen Informationen, Differenzialdiagnosen, Abklärungsmodalitäten sowie kursorisch die Therapieprinzipien und neue wissenschaftliche Erkenntnisse darstellt.
Kongenitaler Hyperinsulinismus
Authors: Empting Susann , Mohnike Klaus
Published: December 2024

Bereits in den 1950er-Jahren wurde eine Familie mit leuzinsensitiver Hypoglykämie beschrieben, die erstmals eine genetische Ursache der „idiopathischen Hypoglykämie des Säuglings McQuarry“ vermuten ließ. Jedoch erst in den 1990er-Jahren konnten genetische Ursachen des damals unspezifisch als Nesidioblastose bezeichneten kongenitalen Hyperinsulinismus nachgewiesen werden. Diese Erkenntnisse zur Pathogenese führten bereits wenige Jahre später zur lebenslangen Heilung für etwa ein Drittel der zuvor intensivmedizinisch betreuten Säuglinge. Bei dieser Teilgruppe liegt ein umschriebener hochaktiver Fokus im Pankreas vor, der häufig laparoskopisch entfernt werden kann. Auch für die medikamentöse Therapie gibt es den Ausblick auf eine Präzisionstherapie mit löslichem Glukagon, spezifischem Insulinrezeptorantikörper und einem spezifischen GLP-1-Antagonisten.
Alles kann – nichts muss? Genesungsbegleitung (Peer-Support) auf
akutpsychiatrischen Stationen
Authors: Stolz Celina , Oster Anna , Czernin Klara , Baumgartner Josef , Junghanss Julia , Mahler Lieselotte
Published: December 2024

Diese qualitative Studie untersucht Genesungsbegleitung im akutpsychiatrischen
Setting. Es wurden vier Genesungsbegleitende, zwölf andere Mitarbeitende und
vier Patient:innen zweier Stationen in semistrukturierten Interviews befragt.
Genesungsbegleitende erleben in diesem Kontext besondere Chancen und
Herausforderungen. Die Befragten gaben an, dass Genesungsbegleitende die
Vermittlung zwischen Patient:innen und Team und eine Normalisierung des
Stationsalltags durch Aktivitäten, Förderung sozialer Kontakte bewirkten und
Verständnis und Vertrauen durch ähnliche Erfahrungen sowie Hoffnung und
Selbstwirksamkeit vermittelten. Die anderen Mitarbeitenden profitieren von der
Weitergabe wichtiger Informationen über Patient:innen, Entlastung durch
Aufgabenübernahme, Sensibilisierung für Stigmatisierungen sowie Förderung ihrer
Recovery-Einstellung. Genesungsbegleitende haben keinen direkten Einfluss auf
Zwangsmaßnahmen, tragen aber zur Deeskalation und Aufarbeitung bei. Spezifische
Rahmenbedingungen sind notwendig.
Maternal Prepregnancy Body Mass Index and Risk of Preterm Birth: The Role of Weight Gain during Pregnancy, Race, and Ethnicity
Authors: Sawadogo Wendemi , Tsegaye Medhin , Gizaw Andinet , Newland Hunter , Adera Tilahun
Published: December 2024

Objective Preterm birth (PTB) is one of the leading causes of infant and neonatal mortality. Prepregnancy body mass index (BMI; kg/m2) has been linked to PTB but the evidence of this association by weight gain during pregnancy, race, and ethnicity is limited. This study aimed to assess the association between maternal prepregnancy BMI and PTB stratified by weight gain during pregnancy, race, and ethnicity.

Study Design The U.S. natality data from 2017 to 2021 were used. In this analysis, we included mothers who had a live singleton birth and available data for prepregnancy BMI, gestational age at birth, weight gain during pregnancy, race, and ethnicity. Logistic regression models were used to assess the association between prepregnancy BMI categories and PTB stratified by weight gain during pregnancy, race, and ethnicity.

Results A total of 17,311,509 singleton live births were included of which 1,393,889 (8.05 %) were PTBs. After adjusting for confounders, compared with normal prepregnancy BMI mothers (18.5–24.9), those with underweight BMI (<18.5) were at increased odds of PTB regardless of weight gain during pregnancy, race, and ethnicity. However, for mothers with a prepregnancy BMI above the normal weight (≥25), the association between prepregnancy BMI and PTB differs by weight gain during pregnancy, race, and ethnicity. Asian mothers with obesity II (35.0–39.9) had 93% (odds ratio [OR] = 1.93, 95% confidence interval [CI]: 1.62–2.30) increased odds of PTB for weight gain during pregnancy of 31 to 40 pounds. Their White, Hispanic, and Black counterparts experienced lower odds of PTB for similar weight gain during pregnancy (White: OR = 1.56, 95% CI: 1.51–1.60; Hispanic: OR = 1.48, 95% CI: 1.41, 1.54; and Black: OR = 1.22, 95% CI: 1.17–1.27).

Conclusion Mothers with underweight BMI were at increased risk of PTB regardless of weight gain during pregnancy, race, and ethnicity. However, the association between high prepregnancy BMI and PTB varied by weight gain during pregnancy, race, and ethnicity.

Key Points
Plants with Hair Growth Activity for Alopecia: A Scoping Review on Methodological Aspects
Authors: Galende Sharize Betoni , Paula Mariana Nascimento de , Fachi Mariana Millan , Medeiros Araújo Daniela Cristina de , Chierrito Danielly , Mello João Carlos Palazzo de
Published: December 2024

Alopecia is a common dermatological disorder of patchy hair loss with substantial patient burden. Phytotherapeutic compounds are increasingly used as a source of new therapeutic options. This review aimed to synthesize the evidence on plant species in hair growth and the methodological aspects of in vivo experimental models. The systematic scoping review was conducted following the PRISMA checklist, the Joanna Briggs Institute, and in accordance with Cochrane. A systematic search was carried out in the Pubmed, Scopus, Web of Science, and SciELO databases. In vivo experiments that evaluated hair growth activity using natural substances of plant origin were included. Data collection and analysis: a total of 1250 studies were identified, of which 175 were included for qualitative synthesis. Of these, 128 used mice, 37 rats, 10 rabbits, 1 guinea pig, and 1 sheep as animal models. The methodologies mapped were as follows: hair growth analysis, histological analysis,
immunohistochemistry, gene expression analysis, Western blot, enzyme-linked immunosorbent assay, and biochemical analysis. Minoxidil and finasteride were the most commonly used positive controls. The studies evaluated plant species (166), algae (11), or isolated substances (31). Overall, 152 plant species and 37 isolated substances were identified. This is the first systematic scoping review on the methodological aspects of in vivo hair growth activity. We created a checklist to be completed by authors to allow data comparison and reproducibility, facilitate data interpretation by readers, and ensure better quality of evidence. This work may become a valuable tool for future research and contribute to significant advances in hair growth studies.
Unsupervised data-driven response regime exploration and identification for dynamical systems
Authors: Farid Maor
Published: December 2024

Data-Driven Response Regime Exploration and Identification (DR2EI) is a novel and fully data-driven method for identifying and classifying response regimes of a dynamical system without requiring human intervention. This approach is a valuable tool for exploring and discovering response regimes in complex dynamical systems, especially when the governing equations and the number of distinct response regimes are unknown, and the system is expensive to sample. Additionally, the method is useful for order reduction, as it can be used to identify the most dominant response regimes of a given dynamical system. DR2EI utilizes unsupervised learning algorithms to transform the system’s response into an embedding space that facilitates regime classification. An active sequential sampling approach based on Gaussian Process Regression is used to efficiently sample the parameter space, quantify uncertainty, and provide optimal trade-offs between exploration and exploitation. The performance of the DR2EI method was evaluated by analyzing three established dynamical systems: the mathematical pendulum, the Lorenz system, and the Duffing oscillator, and its robustness to noise was validated across a range of noise magnitudes. The method was shown to effectively identify a variety of response regimes with both similar and distinct topological features and frequency content, demonstrating its versatility in capturing a wide range of behaviors. While it may not be possible to guarantee that all possible regimes will be identified, the method provides an automated and efficient means for exploring the parameter space of a dynamical system and identifying its underlying “sufficiently dominant” response regimes without prior knowledge of the system’s equations or behavior.
Periodic external driving of transmission-delay-coupled phase oscillator system: Switching between different twisted states
Authors: Kang Jin-Song , An Yong-Hyok , Kim Ryong-Son , Choe Chol-Ung
Published: December 2024

We consider the effects of an external periodic forcing on a spatially extended system that consists of identical phase oscillators coupled with transmission delays on a ring. Analyzing the continuum limit N→∞ of the model system along the Ott–Antonsen invariant manifold, we obtain the stability diagram for two regimes, called the forced and drifting entrainments. The former exhibits a spatially homogeneous solution trying to lock onto the drive, of which the stability boundary is rigorously determined. The latter represents a spatially organized group of oscillators that entrain one another at a frequency different from that of the drive. We show that in the drifting entrainment the external driving triggers the occurrence of unusual twisted states, characterized by nonuniform phase gradient as well as by the traveling wave of the order parameter amplitude. Moreover, it is found that by increasing or decreasing the forcing strength one can effectively switch between twisted states with different winding numbers. Our theoretical and numerical results for the reduced system are supported by the direct numerical simulations of the model system.
Diversifying training data does not improve generalizability of neural network models for PV identification
Authors: Ranalli Joseph , Zech Matthias , Tetens Hendrik-Pieter
Published: December 2024

Data about behind-the-meter photovoltaics (PV) installations may be difficult to obtain for researchers. A number of investigators have considered deep learning as an attractive solution to this challenge, capable of directly identifying PV installations from aerial or satellite images. Deep learning models are well known to experience challenges when working with data from sources that they have never been exposed to. This study investigated whether generalizability can be improved by diversifying training data across available labeled data sources. We assessed the performance of models trained on all possible combinations of six different labeled datasets of aerial PV imagery, with a fixed number of total training images. Unfortunately, our results indicate that no combination of model training data achieved generalized performance that approaches models trained on data from a target data source. This implies that generalized ResNet models cannot be developed simply by modifying the configuration of the training data. Consequently, researchers should expect that some degree of data labeling is likely to be necessary when adapting these models to new applications, but our results do indicate that significant performance improvements are possible with only small (∼20%) introductions of target data. Future work may investigate alternative architectures, expanded training datasets, or ways to reduce the amount of labeled data necessary to adapt a model for a given application.
Toward robust electronic coupling predictions in redox-active TEMPO/TEMPO+ systems
Authors: Mitra Souvik , Zens Clara , Kupfer Stephan , Diddens Diddo
Published: December 2024

This research elucidates the intricate nature of electronic coupling in the redox-active (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO), commonly utilized in organic radical batteries. This study employs a combination of classical molecular dynamics and various electronic coupling calculation schemes. Within the context of the generalized Mulliken–Hush method, the electronic couplings are investigated via the complete active space self-consistent field approach, in combination with n-electron valence state perturbation theory, to provide an accurate description of both static and dynamic electron correlation as well as using (time-dependent) density functional theory simulations. Furthermore, the electronic communication between redox-active sites is studied using the cost-efficient density functional theory (DFT)-based frontier molecular orbital (FMO) approach. Our study reveals the dependence of the electronic coupling on the distance and the relative orientation of the redox pairs (TEMPO and TEMPO+). Apart from the expected exponential distance dependence, we found pronounced orientation dependence, with coupling values varying up to 0.2 eV, which is reflected by a substantial basis set dependency of the couplings, in particular at short distances. In addition, our study highlights the limitations of the DFT-based FMO method, in particular at short intermolecular distances between the redox-active sites, which may lead to a mixing of the involved molecular orbitals. This comparison will provide us with the most cost–accuracy-effective method for calculating electronic couplings in TEMPO–TEMPO+ systems.
Adaptive network approach to exploration–exploitation trade-off in reinforcement learning
Authors: Moradi Mohammadamin , Zhai Zheng-Meng , Panahi Shirin , Lai Ying-Cheng
Published: December 2024

A foundational machine-learning architecture is reinforcement learning, where an outstanding problem is achieving an optimal balance between exploration and exploitation. Specifically, exploration enables the agents to discover optimal policies in unknown domains of the environment for gaining potentially large future rewards, while exploitation relies on the already acquired knowledge to maximize the immediate rewards. We articulate an approach to this problem, treating the dynamical process of reinforcement learning as a Markov decision process that can be modeled as a nondeterministic finite automaton and defining a subset of states in the automaton to represent the preference for exploring unknown domains of the environment. Exploration is prioritized by assigning higher transition probabilities to these states. We derive a mathematical framework to systematically balance exploration and exploitation by formulating it as a mixed integer programming (MIP) problem to optimize the agent’s actions and maximize the discovery of novel preferential states. Solving the MIP problem provides a trade-off point between exploiting known states and exploring unexplored regions. We validate the framework computationally with a benchmark system and argue that the articulated automaton is effectively an adaptive network with a time-varying connection matrix, where the states in the automaton are nodes and the transitions among the states represent the edges. The network is adaptive because the transition probabilities evolve over time. The established connection between the adaptive automaton arising from reinforcement learning and the adaptive network opens the door to applying theories of complex dynamical networks to address frontier problems in machine learning and artificial intelligence.
Hippocampus encoding memory engrams as stable heteroclinic network
Authors: Yang Lei , Zhang Honghui , Sun Zhongkui
Published: December 2024

The transient activity of the brain can be characterized by stable heteroclinic channels (SHCs) in the phase space of dynamical models, and the saddle points can represent the metastable states of brain activity. Inspired by this view, based on the hippocampal CA3–CA1 synaptic network model of memory we constructed earlier, we encode memory engrams as trajectories within the SHC in phase space. Short-term memory is transformed into long-term memory and then is encoded as trajectories within the SHC. The saddle points indicate the information blocks that have been segmented during the process of short-term memory. A stable heteroclinic network (SHN) is composed of multiple SHCs, whose trajectories express the memory engrams formed after the conversion of multiple short-term memories into long-term memories. From the existence conditions of SHC and SHN, the asymmetric regulation of neurotransmitters such as acetylcholine on the inhibition strength of adjacent postsynaptic neurons determines the capacity of short-term memory and participates in the encoding of long-term memory. Numerical results reveal the hysteresis effect of saddle points on the trajectories that reflect the limited capacity of short-term memory. All saddle points in the SHNs enable long-term memory to possess an extremely large capacity. Moreover, while noise in the hippocampal circuit can lead to the loss or confusion of memory information, it can also facilitate the encoding of long-term memories. The model and its theoretical analysis allow us to explain memory from the perspective of dynamics and have guiding significance for understanding the encoding and storage process of memory.
Broadband low-frequency sound insulation of a sandwich acoustic metamaterial with coupled-resonance
Authors: Li Ren-Sheng , Sun Xiao-Wei , Tian Jun-Hong , Song Ting , Chen Meng-Ru , Gao Xing-Lin
Published: December 2024

To broaden the bandwidth, a sandwich acoustic metamaterial with periodically rib-stiffened cores is presented by incorporating strip masses. The normal sound transmission loss of the structure is predicted using the finite element method. Results indicate that the two attenuation peaks are coupled, which is validated by the impedance tube experiment. The primary mechanism of the coupled-resonance is attributed to the continuous non-zero effective dynamic surface mass density between two anti-resonances. The conditions for generating the coupled-resonance are derived based on the dual mass-spring model without resolving the matrix eigenvalues. Numerical verifications suggest that the coupled band will break down into two isolated narrow bands if the conditions fail.
Network structure and time delays shape synchronization patterns in brain network models
Authors: Pinder Iain , Nelson Martin R. , Crofts Jonathan J.
Published: December 2024

In this paper, we investigate synchronization patterns and coherence for a network of delayed Wilson–Cowan nodes. To capture information processing across different brain regions, our model incorporates two distinct delays: an intra-nodal delay that reflects the time signals take to travel within a cortical region due to local circuitry and an inter-nodal delay representing the longer communication times associated with white matter connections between brain areas. To investigate the role of network topology, we consider a range of toy network structures as well as the known (macro-scale) cortical structure of the Macaque monkey. We examine how global network dynamics are shaped by a combination of network configuration, coupling strength, and time delays. Our focus lies on two dynamic measures: synchrony and metastability, the latter reflecting the temporal variation of the former, both crucial for the brain’s real-time functionality. Our investigation identifies extensive regions within the system’s parameter space where the synchronized state exhibits transverse instabilities. These instabilities give rise to diverse dynamical behaviors contingent upon the network architecture and the interplay between coupling strength and time delay. While similar complex partially synchronized states existed for all network topologies considered, the cortical network demonstrated time-dependent behaviors, such as phase cluster dynamics, which were absent in the toy network architectures, and which are considered crucial in its ability to orchestrate complex information processing and behavior. Additionally, we illustrate how delays can regulate a cortical network with chaotic local dynamics, thus emphasizing the potential importance of delays in suppressing pathological spreading dynamics.
Study on flexural resilience of composite foam sandwich structures under hygrothermal environment
Authors: Gai Di , Yang Shiyu , Xu Hai , Yang Kang , Yao Zhipeng , Yu Shengjie , Chen Yanhe
Published: December 2024

Under hygrothermal environments, the structural stability and strength of all-fiber composite aircraft are significantly affected during long-term flight use. The wing skin, as a critical structural component, plays a vital role in bearing and transmitting aerodynamic loads. Therefore, it is crucial to investigate the structural compressive stability and strength of the wing skin throughout the aircraft's entire life cycle under these conditions. This study employs a real wing carbon fiber foam sandwich structure to investigate the compressive stability and strength of the wing skin structure of a new energy aircraft under actual flight conditions, specifically during the entire process of the room temperature dry state (RTD) and elevated temperature wet state (ETW). Initially, three-point bending tests were conducted on carbon fiber reinforced polymer (CFRP) laminates, foam cores, and CFRP reinforced foam sandwich structures. The CFRP laminates fully rebounded after bending damage in both the RTD and ETW environments. While CFRP reinforced foam sandwich structures also rebounded fully in the RTD environment, their rebound performance diminished in hygrothermal conditions due to the thermoplastic mobility of the foam cores, resulting in only weak rebound capabilities. In hygrothermal environments, the thermoplastic mobility of the foam core leads to diminished resilience after bending damage, resulting in only weak rebound capabilities. Subsequently, compressive instability tests were conducted on the wing skin foam sandwich structure. The results indicated that the basic test study effectively predicted the structural test outcomes. Structural components in the RTD environment exhibited overall flexural instability under compressive load, with damage morphology resembling a circular curve; the damaged specimens fully rebounded after unloading. Conversely, specimens in the ETW environment displayed localized instability, characterized by a wrinkled damage profile, resulting in only weak rebound capabilities after unloading.
Investigation of the electrical performance and carrier transport mechanism for heterostructured bilayer In2O3/InGaSnO thin-film transistors
Authors: Han Zhenyu , Abliz Ablat
Published: December 2024

In this study, InGaSnO (IGTO)-based bilayer In2O3/IGTO and IGTO/In2O3 thin-film transistors (TFTs) were designed, and their carrier transport mechanisms and electrical performances were investigated. Herein, the ultrathin In2O3 layer provided a higher carrier concentration (Ne), thus accumulating free carriers and enhancing the carrier mobility. The thick amorphous IGTO layer controlled the device and carrier conductance, yielding a reasonable threshold voltage (Vth). Consequently, the optimized bilayer In2O3/IGTO TFTs exhibited high field-effect mobility (μFE) of 43.6 cm2 V−1s−1 and good control with Vth of 1.2 V compared to the single layer In2O3 and IGTO TFTs. Experimental analysis indicated a decrease in the oxygen vacancy (VO) formation energy owing to the interaction between interstitial Ini and Sn. Consequently, numerous unpaired electrons were generated from VO at the hetero-interfaces. In addition, an analysis of the energy band shift indicated that the heterojunction generated parasitic channels to control the Ne, and the In2O3/IGTO TFT exhibited a smaller Rc (0.34 KΩ μm), which enhanced the μFE of TFTs. Overall, the high-performance bilayer In2O3/IGTO TFTs fabricated herein have significant potential for applications in thin-film electronics.
Complete RITZ Set of Ro-Vibrational Energy Levels of 16O3 Deduced from Experimental Spectra: Critical Analysis of Transition Frequencies in Spectroscopic Databases
Authors: Tashkun Sergey , Barbe Alain , Mikhailenko Semen , Starikova Evgeniya , Tyuterev Vladimir
Published: December 2024

In this work, we provide the most complete to date reference data for 28 572 rovibrational levels of the electronic ground state of the ozone 16O3 molecule up to the maximum rotational quantum numbers J = 80, Ka = 29 determined from 75 290 experimental transitions covering the range (0.3–7999) cm−1. These energy levels belong to 98 vibrational states extending up to 96.7% of the first dissociation threshold D0 of the molecule. The energy determination procedure is based uniquely on the fundamental Ritz-Planck-Einstein energy conservation principle without use of any approximate Hamiltonian models. A dedicated RITZ computer code produces uncertainties and the correlation matrix for all derived energy levels and permits the prediction of confidence intervals for all dipole-allowed transitions among these levels. The rms deviation of the RITZ transitions for microwave experimental data up to the THz range is 2.6 × 10−6 cm−1. For infrared transitions up to the fundamental and second overtone and combinational bands, including 10 and 5 µm regions important for atmospheric and astrophysical applications, the rms deviation is 1.8 × 10−4 cm−1. For the entire set of lines, the rms deviation is 5.5 × 10−4 cm−1 with the overall dimensionless weighted standard deviation of 0.7. Most of the energy level data is original. For the regions above 6000 cm−1, where empirical data have been previously obtained in the literature from CRDS laser measurements, our data agree well with the published values but provide a more realistic uncertainty analysis. Detailed comparisons of the RITZ transitions with the HITRAN2020 database are discussed and related recommendations are suggested.
Indenting fractal-edged elastic materials
Authors: Costa D. F. S. , Pontes J. H. M. , Ferreira W. P. , de Sousa J. S. , Oliveira C. L. N.
Published: December 2024

Surface roughness plays a crucial role in the accuracy of indentation experiments used to measure the elastic properties of materials. In this study, we present a computational analysis of how surface roughness, represented explicitly by fractal geometry, influences the mechanical properties of soft materials. We model two-dimensional elastic samples with a Koch fractal bottom surface, grown upward or downward to the fourth generation, referred to as fractal down and fractal up, respectively. The elastodynamics equations are solved numerically while a rigid punch indents the elastic sample from the top surface. By applying the Hertz model for mechanical contact, we determine Young’s modulus of the materials. Our findings reveal that fractal surfaces, especially those with dimensions comparable to the sample size, can significantly alter experimental measurement outcomes. In particular, the roughness of the substrate profoundly affects the measured elastic properties, as seen in scenarios involving cell elasticity. For instance, in the down fractal scenario, reductions in the measured elastic modulus range from 2% to 4%, while increases reach up to 40% in the up fractal scenario. These results underscore the importance of incorporating fractal geometry into the design and analysis of indentation experiments. This approach could significantly enhance our understanding and application of material characterization and mechanical testing, leading to more accurate and reliable results. Our numerical findings align with experimental trends, with reduced elastic modulus observed in the down scenario, similar to surfaces treated with abrasives, and increased stiffness in the up scenario, akin to bonded materials with induced roughness.
Emergent local negative electrostriction induced by oxygen vacancy in BaHfO3: Defect engineering
Authors: Ikeda Yoshitaka , Minami Susumu , Shimada Takahiro
Published: December 2024

Realization of ultrasmall scale electromechanical materials has been promising for advanced functional devices. Recently, single-atom devices have been proposed as the ultimate miniaturization of functional devices beyond the nanoscale; however, achieving an atomic-scale local electromechanical response is still challenging due to physical size limitation of electromechanical properties as well as technical difficulties in fabricating the functional materials in a single atom precision. Here, we demonstrate a non-trivial negative electromechanical response at an oxygen vacancy in paraelectric BaHfO3 using first-principles finite electric field calculations. We find an electrostrictive response at the vacancy site in the same order of magnitude in well-known oxide materials. Surprisingly, we also discover an unusual “negative” sign of electrostriction in the oxygen vacancy. The detailed electronic structure analysis demonstrates that a unique electric field response of a localized defect electronic structure is the origin of this negative electrostriction of vacancy. The present results provide an important implication for the design of ultra-small electromechanical functions at an atomic scale.
Development of a dual-spectroscopic system to rapidly measure diisopropyl methyl phosphonate (DIMP) decomposition and temperature in a reactive powder environment
Authors: Borah Preetom , Alemohammad Milad , Foster Mark , Weihs Timothy P.
Published: December 2024

The development of systems to measure and optimize emerging energetic material performance is critical for Chemical Warfare Agent (CWA) defeat. In order to assess composite metal powder efficacy on CWA simulant defeat, this study documents a combination of two spectroscopic systems designed to monitor the decomposition of a CWA simulant and temperature rises due to combusting metal powders simultaneously. The first system is a custom benchtop Polygonal Rotating Mirror Infrared Spectrometer (PRiMIRS) incorporating a fully customizable sample cell to observe the decomposition of Diisopropyl Methyl Phosphonate (DIMP) as it interacts with combusting composite metal particles. The second is a tunable diode laser absorption spectroscopy (TDLAS) used to monitor increases in background gas temperatures as the composite metal powders combust. The PRiMIRS system demonstrates a very high signal to noise ratio (SNR) at slow timescales (Hz), reasonable SNR when operating at faster timescales (100 Hz), and capabilities of resolving spectral features with a FWHM resolution of 15 cm−1. TDLAS was able to monitor temperature rises between room temperature and 230 ± 5 °C while operating at 100 Hz. For testing, liquid DIMP was inserted in a preheated stainless steel (SS) cell to generate DIMP vapor and (Al–8Mg):Zr metal powders were ignited in a SS mount with a resistively heated nichrome wire at one end of the cell. The ignited particles propagated across the cell containing DIMP vapor. The path averaged gas temperature in the preheated SS cell rises rapidly (100 ms) and decays slowly (<5 s) but remains below 230 °C during particle combustion, a temperature at which the thermal decomposition of DIMP is not observed over similarly short timescales (seconds). However, when combusting particles were introduced to the DIMP vapor (heterogeneous environment), spectral signatures indicative of decomposition product formation, such as isopropyl-methyl phosphonate (IMP) and isopropyl alcohol, were observed within seconds.
A dynamical study of Hilda asteroids in the Circular and Elliptic RTBP
Authors: Jorba Àngel , Nicolás Begoña , Rodríguez Óscar
Published: December 2024

The Hilda group is a set of asteroids whose mean motion is in a 3:2 orbital resonance with Jupiter. In this paper, we use the planar Circular Restricted Three-Body Problem (CRTBP) as a dynamical model and we show that there exists a family of stable periodic orbits that are surrounded by islands of quasi-periodic motions. We have computed the frequencies of these quasi-periodic motions and we have shown how the Hilda family fits inside these islands. We have compared these results with the ones obtained using the Elliptic Restricted Three-Body Problem and they are similar, showing the suitability of the CRTBP model. It turns out that, to decide if a given asteroid belongs to the Hilda class, it is much better to look at its frequencies in the planar CRTBP rather than to use two-body orbital elements as it is commonly done today.
Finding critical exponents and parameter space for a family of dissipative two-dimensional mappings
Authors: da Costa Fábio H. , de Almeida Mayla A. M. , Medrano-T Rene O. , Leonel Edson D. , de Oliveira Juliano A.
Published: December 2024

A family of dissipative two-dimensional nonlinear mappings is considered. The mapping is described by the angle and action variables and parameterized by ε controlling nonlinearity, δ controlling the amount of dissipation, and an exponent γ is a dynamic free parameter that enables a connection with various distinct dynamic systems. The Lyapunov exponents are obtained for different values of the control parameters to characterize the chaotic attractors. We investigated the time evolution for the stationary state at period-doubling bifurcations. The convergence to the stationary state is made using a robust homogeneous and generalized function at the bifurcation parameter, which leads us to obtain a set of universal critical exponents. The parameter space of the mapping is investigated, and tangent, period-doubling, pitchfork, and cusp bifurcations are found, and a street of saddle-area and spring-area structures is observed.
Dielectrophoretic force-enhanced thermal convection within a horizontal cylindrical annulus
Authors: Hamede M. H. , Roller J. , Meyer A. , Heuveline V. , Egbers C.
Published: December 2024

This study investigates, both experimentally and numerically the flow of a dielectric fluid confined between two concentric, differentially heated, horizontally aligned cylinders subjected to a 200 Hz alternating radial electric field. A wide-gap annular setup with a length 20 times larger than the gap size is utilized in this investigation. The study focuses exclusively on the outward heating configuration, meaning the inner cylinder is hotter than the outer one. The electric field, in conjunction with the temperature gradient, triggers thermal electro-hydrodynamic instability caused by the application of dielectrophoretic force. when the applied electric tension exceeds a critical value for specific temperature gradients between the cylinders, the flow symmetry in the gap is disturbed. The instability manifests as periodically oscillating vortices occurring on top of the gap. A notable increase in heat transfer efficiency accompanies the onset of instability. The experimental and numerical results demonstrate quantitative and qualitative agreement.
Two-point methods for evaluation of the minimum zone circle
Authors: Li Xiuming , Hao Xuedi , Wang Guangjie , Tang Yuanzhuo , Li Xudong
Published: December 2024

According to the cross-distribution of four control points of the minimum zone circle, the four-point conditions that two control points on the circumscribed circle and two control points on the inscribed circle meet are proposed. Based on these conditions, a two-point method is proposed, which is suitable not only for the determination of two control points on the circumscribed circle but also for the determination of two control points on the inscribed circle. In the iterative process, redundant data points can be simply determined by using dichotomy in order to improve computational efficiency. Several examples have been carried out to validate the validity of the algorithm proposed.
Convergence of the many-body expansion with respect to distance cutoffs in crystals of polar molecules: Acetic acid, formamide, and imidazole
Authors: Nelson Philip M. , Sherrill C. David
Published: December 2024

The many-body expansion, where one computes the total energy of a supersystem as the sum of the dimer, trimer, tetramer, etc., subsystems, provides a convenient approach to compute the lattice energies of molecular crystals. We investigate approximate methods for computing the non-additive three-body contributions to the crystal lattice energy of the polar molecules acetic acid, imidazole, and formamide, comparing to coupled-cluster singles, doubles, and perturbative triples [CCSD(T)] level benchmarks. Second-order Møller–Plesset perturbation theory (MP2), if combined with a properly damped Axilrod–Teller–Muto dispersion potential, displays excellent agreement with CCSD(T) at a substantially reduced cost. Errors between dispersion-corrected MP2 and CCSD(T) are less than 1 kJ mol−1 for all three crystals. However, the three-body energy requires quite large distance cutoffs to converge, up to 20 Å or more.
Distributed optimization consensus for multi-agent systems on matrix-weighted networks
Authors: Miao Suoxia , Xiong Ruxin , An Qing , Bao Cuihong , Sun Yaping , Su Housheng
Published: December 2024

In this paper, the distributed optimization consensus issues for both first-order continuous time (CT) and discrete-time (DT) multi-agent systems (MASs) on matrix-weighted networks are studied. In order to make each agent achieve optimization consensus, a new matrix-weighted distributed optimization algorithm for CT and DT MASs is proposed. Using the Lyapunov stability theory and matrix theory, the optimization consensus conditions are obtained, respectively. Finally, the correctness of our results is verifiied by numerical examples.
The slow wave resonance cone in the collisional regime
Authors: Tierens W.
Published: December 2024

In the low-density edge plasma of tokamaks, ion cyclotron range of frequencies actuators may parasitically emit slow waves. If the density is sufficiently low, which may be common in large future devices such as international thermonuclear experimental reactor (ITER), these slow waves take the form of so-called resonance cones. The traditional theoretical description of this wave mode relies on formally relating an electrostatic approximation of the frequency-domain wave equation to a time-domain wave equation and relating the cone angle to the wave speed in the time-domain wave equation. In the cold plasma collisional regime, that wave speed is complex. We investigate that scenario in this work.
Propagation of cylindrical converging shock wave in rotating ideal gas containing dust particles
Authors: Gupta Nandita , Arora Rajan
Published: December 2024

In this article, the propagation of strong converging cylindrically symmetric shock waves in ideal dusty gas is studied using the Lie group technique while considering the effect of an axial magnetic field in a rotating gas atmosphere. The constant density in an undisturbed medium is assumed, whereas the magnetic field, the azimuthal, and axial components of fluid velocity are considered to be varying. The arbitrary constants appearing in the expressions for infinitesimals of the Local Lie group of transformations bring about three different cases of solutions, i.e., with power-law shock path, exponential-law shock path, and a particular case of power-law shock path. Numerical solutions are obtained in the cases of the power-law shock path. The self-similar solutions to the problem are obtained, and the effect of the Shock Cowling number, the mass concentration of solid dust particles, the relative specific heat, the ratio of the density of solid particles, and the ambient azimuthal velocity exponent on the shock evolution are depicted through graphs.
Experimental insights into droplet behavior on Van der Waals and non-Van der Waals liquid-impregnated surfaces
Authors: Ganar Shubham S. , Das Arindam
Published: December 2024

Droplet impact is a fascinating phenomenon that occurs when a liquid droplet collides with a surface. It is not only a fundamental area of scientific inquiry but also has practical implications across many industries and natural systems. The dynamics during droplet impact on liquid-impregnated surfaces (LIS) are of special interest because the properties of the surface and impregnated liquid may significantly change the impact outcome. We present a detailed study of the impact and subsequent retraction of liquid droplets on a liquid-impregnated surface using high-speed imagery. Square-shaped textures with varying post-spacings of 5, 20, and 30 μm on a silicon wafer were fabricated and functionalized using octadecyltrichlorosilane. Two different lubricants, silicone oil and hexadecane, were infused to investigate how their properties affect impact dynamics. Droplet impacts were investigated on these surfaces across a broad range of Weber numbers, i.e., (28–495). Additionally, we measured the stability of the LIS surface by calculating spreading coefficients and contact angles. The experiments revealed that the properties of the infused oil play an insignificant role in droplet dynamics, including spreading, rebound, and unique phenomena related to oil interaction with surface textures. This study provides insights into the intricate dynamics of droplet interactions with LIS, offering valuable contributions to understanding surface-wetting phenomena.
Ultralow limit human IgG detection with 2H-MoS2/L-cysteine based plasmonic fiber-optic spectral combs
Authors: Sui Wenbo , Ren Ziqiao , Cao Yunjie , Feng Xijie , Wang Fuxiang , Wu Jun , Zhou Wenjun , Dong Jie , Zhou Jun , Shen Changyu
Published: December 2024

The detection of human immunoglobulin G (human IgG) provides crucial evidence in diagnosis of infectious diseases and monitoring of therapeutic effects. Here, we propose a plasmonic fiber-optical surface plasmon resonance (SPR) based sensor to realize the ultralow limit human IgG detection. The proposed sensor is fabricated by attaching a mixture of 2H-MoS2 nanosheets with L-cysteine on a gold-coated tilted fiber Bragg grating. The 2H-MoS2 possesses a large specific surface area, where the L-cysteine can enhance the stability of antibody modification. The composite membrane of 2H-MoS2 and L-cysteine can adsorb more probe rabbit anti-human IgG, which can improve sensitivity of the proposed sensor. The experimental results show that the proposed sensor exhibits a response time of approximately 220 s and a sensitivity of 0.11 dB/(ng/ml). The limit of detection of 0.87 ng/ml of the proposed sensor is one order of magnitude lower than those of other fiber-optic SPR human IgG sensors.
Direct simulations of bedrock core and cuttings transport phenomena in reverse circulation drilling
Authors: Sun Ni , Ye Ting , Wang Rusheng
Published: December 2024

Polar drilling is essential for obtaining ice and bedrock samples, providing critical insights into climate and geological history. The reverse circulation drilling method, utilizing a dual-wall drill pipe, presents a stable and efficient strategy. Nonetheless, the intricate dynamics involving drilling fluids, rock cuttings and cores necessitate sophisticated modeling to elucidate the underlying mechanism and optimize drilling efficiency. To address this, we developed a multiphase flow model that accounts for non-Newtonian fluid behavior, turbulence, particle dynamics, and fluid–structure interactions, enabling a thorough assessment of various operational parameters. The model's temporal–spatial sensitivity was evaluated, and its accuracy was confirmed by comparison with three different sets of experimental data. A detailed parametric investigation was then conducted to systematically assess the effects of various parameters, including the non-Newtonian behavior and inlet velocity of the drilling fluid, the rate of penetration, and the dimensions of the cuttings and core. The simulation results indicate that the non-Newtonian behavior of the drilling fluid has an non-negligible effect on the transport efficiency of both cuttings and core. An increase in the fluid inlet velocity leads to faster transport, albeit at the cost of higher pump pressure. The rate of penetration has a minor influence on the core transportation but largely affects the cutting transportation. More interestingly, larger cuttings demonstrate enhanced transport efficiency, attributed to a more uniform velocity distribution. Furthermore, the core diameter plays a pivotal role in transport efficiency by significantly altering the fluid dynamics, whereas the core length has a negligible effect. These results may have direct applications for optimizing polar drilling operations, potentially leading to enhanced drilling efficiency, reduced drilling costs, and informing future drilling technology advancements.