bluuebunny/crossref_metadata_2025 huggingface dataset:
DBNets: A publicly available deep learning tool to measure the masses of young planets in dusty protoplanetary discs
Authors: Ruzza A. , Lodato G. , Rosotti G. P.
Published: February 2024

Current methods to characterize embedded planets in protoplanetary disc observations are severely limited either in their ability to fully account for the observed complex physics or in their computational and time costs. To address this shortcoming, we developed DBNets: a deep learning tool, based on convolutional neural networks, that analyses substructures observed in the dust continuum emission of protoplanetary discs to quickly infer the mass of allegedly embedded planets. We focussed on developing a method to reliably quantify not only the planet mass, but also the associated uncertainty introduced by our modelling and adopted techniques. Our tests gave promising results achieving an 87% reduction of the log Mp mean squared error with respect to an analytical formula fitted on the same data (DBNets metrics: lmse 0.016, r2-score 97%). With the goal of providing the final user of DBNets with all the tools needed to interpret their measurements and decide on their significance, we extensively tested our tool on out-of-distribution data. We found that DBNets can identify inputs strongly outside its training scope returning an uncertainty above a specific threshold and we thus provided a rejection criterion that helps determine the significance of the results obtained. Additionally, we outlined some limitations of our tool: it can be reliably applied only on discs observed with inclinations below approximately 60°, in the optically thin regime, with a resolution ~8 times better than the gap radial location and with a signal-to-noise ratio higher than approximately ten. Finally, we applied DBNets to 33 actual observations of protoplanetary discs measuring the mass of 48 proposed planets and comparing our results with the available literature. We confirmed that most of the observed gaps imply planets in the sub-Jupiter regime.
Approaching the structure of rotating bodies from dimension reduction
Authors: Staelen C. , Huré J.-M.
Published: February 2024

We show that the two-dimensional structure of a rigidly rotating self-gravitating body is accessible with relatively good precision by assuming a purely spheroidal stratification. With this hypothesis, the two-dimensional problem becomes one-dimensional, and consists in solving two coupled fixed-point equations in terms of equatorial mass density and eccentricity of isopycnics. We propose a simple algorithm of resolution based on the self-consistent field method. Compared to the full unconstrained-surface two-dimensional problem, the precision in the normalized enthalpy field is better than 10−3 in absolute, and the computing time is drastically reduced. In addition, this one-dimensional approach is fully appropriate to fast rotators, works for any density profile (including any barotropic equation of state), and can account for mass density jumps in the system, including the existence of an ambient pressure. Several tests are given.
Searching for X-ray counterparts of unassociated Fermi-LAT sources and rotation-powered pulsars with SRG/eROSITA
Authors: Mayer Martin G. F. , Becker Werner
Published: February 2024

Context. The latest source catalog of the Fermi-LAT telescope contains more than 7000 γ-ray sources at giga-electronvolt energies, with the two dominant source classes thought to be blazars and rotation-powered pulsars. Despite continuous follow-up efforts, around 2600 sources have no known multiwavelength association.

Aims. Our target is the identification of possible (young and recycled) pulsar candidates in the sample of unassociated γ-ray sources via their characteristic X-ray and γ-ray emission. To achieve this, we cross-matched the Fermi-LAT catalog with the catalog of X-ray sources in the western Galactic hemisphere from the first four all-sky surveys of eROSITA on the Spektrum-Roentgen-Gamma (SRG) mission. We complement this by identifying X-ray counterparts of known pulsars detected at γ-ray and radio energies in the eROSITA data.

Methods. We used a Bayesian cross-matching scheme to construct a probabilistic catalog of possible pulsar-type X-ray counterparts to Fermi-LAT sources. Our method combines the overlap of X-ray and γ-ray source positions with a probabilistic classification (into pulsar and blazar candidates) of each source based on its γ-ray properties and a prediction on the X-ray flux of pulsar- or blazar-type counterparts. Finally, an optical and infrared counterpart search was performed to exclude coronally emitting stars and active galactic nuclei from our catalog.

Results. We provide a catalog of our prior γ-ray-based classifications of all 2600 unassociated sources in the Fermi-LAT catalog, with around equal numbers of pulsar and blazar candidates. Our final list of candidate X-ray counterparts to suspected new high-energy pulsars, cleaned for spurious detections and sources with obvious non-pulsar counterparts, contains around 900 X-ray sources, the vast majority of which lie in the 95% γ-ray error ellipse. We predict between 30 and 40 new pulsars among our top 200 candidates, with around equal numbers of young and recycled pulsars. This candidate list may serve as input to future follow-up campaigns, looking directly for pulsations or for the orbital modulation of possible binary companions, where it may allow for a drastic reduction in the number of candidate locations to search. We furthermore detect the X-ray counterparts of 15 known rotation-powered pulsars, which were not seen in X-rays before.
Experimental investigations of diacetylene ice photochemistry in Titan’s atmospheric conditions
Authors: Fleury Benjamin , Gudipati Murthy S. , Couturier-Tamburelli Isabelle
Published: February 2024

Context. A large fraction of the organic species produced photochemically in the atmosphere of Titan can condense to form ice particles in the stratosphere and in the troposphere. According to various studies, diacetylene (C4H2) condenses below 100 km where it can be exposed to ultraviolet radiation.

Aims. We studied experimentally the photochemistry of diacetylene ice (C4H2) to evaluate its potential role in the lower altitude photochemistry of Titan’s atmospheric ices.

Methods. C4H2 ice films were irradiated with near-ultraviolet (near-UV) photons (λ > 300 nm) with different UV sources to assess the impact of the wavelengths of photons on the photochemistry of C4H2. The evolution of the ice’s composition was monitored using spectroscopic techniques.

Results. Our results reveal that diacetylene ice is reactive through singlet-triplet absorption, similar to the photochemistry of other organic ices of Titan (such as dicyanoacetylene C4N2 ice) that we investigated previously. Several chemical processes occurred during the photolysis: the hydrogenation of C4H2 to form other C4 hydrocarbons (vinylacetylene C4H4 to butane C4H10); the formation of larger and highly polymerizable hydrocarbons, such as triacetylene (C6H2); and the formation of an organic polymer that is stable at room temperature.

Conclusions. The nondetection of diacetylene ice in Titan’s atmosphere or surface could be rationalized based on our experimental results that C4H2 is photochemically highly reactive in the solid phase when exposed to near-UV radiation that reaches Titan’s lower altitudes and surface. C4H2 may be one of the key molecules promoting the chemistry in the ices and aerosols of Titan’s haze layers, especially in the case of co-condensation with other organic volatiles, with which it could initiate more complex solid-phase chemistry.
Constraints on the evolution of the Triton atmosphere from occultations: 1989–2022
Authors: Sicardy B. , Tej A. , Gomes-Júnior A. R. , Romanov F. D. , Bertrand T. , Ashok N. M. , Lellouch E. , Morgado B. E. , Assafin M. , Desmars J. , Camargo J. I. B. , Kilic Y. , Ortiz J. L. , Vieira-Martins R. , Braga-Ribas F. , Ninan J. P. , Bhatt B. C. , Pramod Kumar S. , Swain V. , Sharma S. , Saha A. , Ojha D. K. , Pawar G. , Deshmukh S. , Deshpande A. , Ganesh S. , Jain J. K. , Mathew S. K. , Kumar H. , Bhalerao V. , Anupama G. C. , Barway S. , Brandeker A. , Florén H. G. , Olofsson G. , Bruno G. , Mao Y. M. , Ye R. H. , Zou Q. Y. , Sun Y. K. , Shen Y. Y. , Zhao J. Y. , Grishin D. N. , Romanova L. V. , Marchis F. , Fukui K. , Kukita R. , Benedetti-Rossi G. , Santos-Sanz P. , Dhyani N. , Gokhale A. , Kate A.
Published: February 2024

Context. In about 2000, the south pole of Triton experienced an extreme summer solstice that occurs every ∼650 years, when the subsolar latitude reached about 50°S. Bracketing this epoch, a few occultations probed the Triton atmosphere in 1989, 1995, 1997, 2008, and 2017. A recent ground-based stellar occultation observed on 6 October 2022 provides a new measurement of the atmospheric pressure on Triton. This is presented here.

Aims. The goal is to constrain the volatile transport models (VTMs) of the Triton atmosphere. The atmosphere is basically in vapor pressure equilibrium with the nitrogen ice at its surface.

Methods. Fits to the occultation light curves yield the atmospheric pressure of Triton at the reference radius 1400 km, from which the surface pressure is deduced.

Results. The fits provide a pressure p1400 = 1.211 ± 0.039 μbar at radius 1400 km (47 km altitude), from which a surface pressure of psurf = 14.54 ± 0.47 μbar is deduced (1σ error bars). To within the error bars, this is identical to the pressure derived from the previous occultation of 5 October 2017, p1400 = 1.18 ± 0.03 μbar and psurf = 14.1 ± 0.4 μbar, respectively. Based on recent models of the volatile cycles of Triton, the overall evolution of the surface pressure over the last 30 years is consistent with N2 condensation taking place in the northern hemisphere. However, models typically predict a steady decrease in the surface pressure for the period 2005-2060, which is not confirmed by this observation. Complex surface-atmosphere interactions, such as ice albedo runaway and formation of local N2 frosts in the equatorial regions of Triton, could explain the relatively constant pressure between 2017 and 2022.
The different flavors of extragalactic jets: Magnetized relativistic flows
Authors: Rossi P. , Bodo G. , Massaglia S. , Capetti A.
Published: February 2024

We performed three-dimensional numerical simulations of magnetized relativistic jets propagating in a uniform density environment in order to study the effect of the entrainment and the consequent deceleration, extending a previous work in which magnetic effects were not present. As in previous papers, our aim is to understand the connection between the jet properties and the resulting Fanaroff-Riley classification. We considered jets with different low densities, and therefore low power, and different magnetizations. We find that lower magnetization jets effectively decelerate to sub-relativistic velocities and may then result in an FR I morphology on larger scales. Conversely, in the higher magnetization cases, the entrainment and consequent deceleration are substantially reduced.
Conservation of Tropical Wild Orchids Through Empowering Local Community in Yogyakarta
Authors: Nuraini Latifah , Wibowo Aninda Retno Utami , Prhatini Istiana
Published: February 2024

Yogyakarta has many tropical wild orchids spread in the karst mountains. After the COVID-19 pandemic, ecotourism has started to develop again, especially in this area, which offers many beautiful tourist spots. The increasing number of tourists visiting the area will increase the demand for wild tropical orchids. The method used in this study was exploration, observation, and interviews with the local farmers were carried out to obtain the primary data. The secondary data was obtained from a qualitative approach through a literature study. Data analysis uses interpretation, and the data obtained in the field will be interpreted from the aspect of the orchid’s conservation process to the ecotourism development. Based on the results of studies and research that have been conducted, this local community-based ecotourism occurred when there is awareness of the local community to maintain and preserve a sustainable environment by utilizing the existing land to be more valuable. This community-based ecotourism also showed a positive impact on the conservation of tropical wild orchids and the protection of the environment.
Effects of Sidempuan Salacca (Salacca sumatrana) Vinegar on Hyperuricemia: Histopathological Assessment
Authors: Atifah Yusni , Diana Okta Putri
Published: February 2024

This research aimed to ascertain the effectiveness of Sidempuan salacca vinegar on improving kidney degeneration in hyperuricemia male mice. The mice were grouped into untreated mice, hyperuricemia mice without treatment, and hyperuricemia mice treated with Sidempuan salacca vinegar. The blood uric acid was measured by Easy Touch GCU, and the histopathology of the kidney was observed using the paraffin method and HE staining. The results demonstrated that Sidempuan salacca vinegar has the ability to decrease blood uric acid significantly. Sidempuan Salacca vinegars have the ability for regeneration in addition to kidney cells. However, the capacity of P3 to regulate hyperuricemia seemed to be better than that of other treatments. Sidempuan salacca vinegar has the potential to be used therapeutically by reducing tissue damage in hyperuricemic mice.
A unified Bayesian inversion approach for a class of tumor growth models with different pressure laws
Authors: Feng Yu , Liu Liu , Zhou Zhennan
Published: February 2024

In this paper, we use the Bayesian inversion approach to study the data assimilation problem for a family of tumor growth models described by porous-medium type equations. The models contain uncertain parameters and are indexed by a physical parameter m, which characterizes the constitutive relation between density and pressure. Based on these models, we employ the Bayesian inversion framework to infer parametric and nonparametric unknowns that affect tumor growth from noisy observations of tumor cell density. We establish the well-posedness and the stability theories for the Bayesian inversion problem and further prove the convergence of the posterior distribution in the so-called incompressible limit, m → ∞. Since the posterior distribution across the index regime m ∈ [2, ∞) can thus be treated in a unified manner, such theoretical results also guide the design of the numerical inference for the unknown. We propose a generic computational framework for such inverse problems, which consists of a typical sampling algorithm and an asymptotic preserving solver for the forward problem. With extensive numerical tests, we demonstrate that the proposed method achieves satisfactory accuracy in the Bayesian inference of the tumor growth models, which is uniform with respect to the constitutive relation.
Semi-online scheduling on two uniform parallel machines with initial lookahead
Authors: Zheng Feifeng , Chen Yuhong , Liu Ming
Published: February 2024

This work studies the problem of semi-online scheduling on two uniform parallel machines with speeds 1 and s (≥2), respectively. We introduce a novel concept of initial lookahead in which any deterministic online algorithm has the full knowledge of the first k jobs at the beginning, while the remaining jobs are released one-by-one in the online over-list mode. The objective of the considered problem is to minimize the makespan. We focus on the case where the first k jobs are of a total processing time not less than (s + 1)Δ where Δ is the largest job length, and it is assumed that s is an integer. We prove a lower bound of
(s2+s+1)/(s2+s)
, and propose a deterministic semi-online algorithm with competitive ratio of (s+1)2/s2+s+1. The ratio is at most 9/7 and much less than that of 1.618 for the corresponding case without initial lookahead (Cho and Sahni, SIAM J. Comput. 9 (1980) 91–103). Our results demonstrate that a finite ability of initial lookahead can greatly improve the competitiveness of online algorithms.
Measuring Hearing Aid Satisfaction in Everyday Listening Situations: Retrospective and In Situ Assessments Complement Each Other
Authors: Lelic Dina , Wolters Florian , Schinkel-Bielefeld Nadja
Published: February 2024

Background Recently, we developed a hearing-related lifestyle questionnaire (HEARLI-Q), which asks respondents to rate their hearing aid (HA) satisfaction in 23 everyday listening situations. It is unknown how HA satisfaction on the retrospective HEARLI-Q scale compares with HA satisfaction measured on the same scale implemented in Ecological Momentary Assessment (EMA).

Purpose To learn how retrospective (HEARLI-Q) and in situ (EMA) assessments can complement each other.

Research Design An observational study.

Study Sample Twenty-one experienced HA users.

Data Collection and Analysis The participants first filled out the HEARLI-Q questionnaire, followed by a 1-week EMA trial using their own HAs. HA satisfaction ratings were compared between the two questionnaires and the underlying drivers of discrepancies in HA satisfaction ratings were evaluated.

Results HA satisfaction ratings were significantly higher in EMA for speech communication with one or several people. Hearing difficulty in these situations was rated higher in HEARLI-Q than in EMA, but occurrence of those difficult listening situations was also rated to be lower. When comparing only the situations that occur on daily or weekly basis, the two questionnaires had similar HA satisfaction ratings.

Conclusions Lower occurrence of difficult listening situations seems to be the key driver of discrepancies in HA satisfaction ratings between EMA and HEARLI-Q. The advantage of EMA is that it provides insight into an individual's day-to-day life and is not prone to memory bias. HEARLI-Q, on the other hand, can capture situations that occur infrequently or are inconvenient to report in the moment. Administering HEARLI-Q and EMA in combination could give a more holistic view of HA satisfaction.
Comparison of Different Surgical Approaches for Treating Aortic Graft Infections
Authors: Xia Yu , Sun Lizhong , Jian Kaitao , Peng Hao , Lin Yi , Liu Wei
Published: February 2024

Background There is still no guideline or consensus on the treatment of aortic graft infection. This study reported and compared conservative and surgical treatment and different surgical methods for aortic graft infection.

Methods Data from aortic graft infections treated at our institution between February 2017 and June 2022 were retrospectively analyzed. Clinical data and surgical approaches were evaluated.

Results This article retrospectively analyzed the treatment and prognosis of 48 patients (43 males) with aortic graft infection. The patients were divided into conservative treatment group (n = 15) and surgical treatment group (n = 33). During follow-up, the mortality rate of the conservative treatment group was significantly higher than that of the surgical treatment group (p < 0.05). The survival curve also showed that the survival time of the surgical treatment group was longer than that of the conservative treatment group (p < 0.05). The surgical treatment group included local treatment (n = 5), in situ replacement (n = 8), and bypass surgery (n = 20) groups. There was no significant difference in the mortality rate at 1 month or final follow-up among the local treatment, in situ replacement, and bypass surgery groups.

Conclusion Surgical treatment is the optimal option for treating aortic graft infections compared to conservative treatment.
High Prevalence of Seasonal and Current Groin Problems in Rink Hockey
Players
Authors: Quintana-Cepedal Marcos , de Pablo Marquez Bernat , del Valle Soto Miguel , Olmedillas Hugo
Published: February 2024

Groin problems are common in multidirectional sports. The aim of the present
study is to assess seasonal, current, and trends for groin problems in rink
hockey players, irrespective of their playing position, age, or gender. Rink
hockey players from three countries [n=446 (162 female, 284 male)] were invited
to participate in an online questionnaire. This form evaluated the prevalence of
groin problems (time-loss and non-time-loss) for the 2022–2023 season, as well
as monthly prevalence of groin problems (time-loss and non-time-loss). All groin
problems were compared between playing position, gender, and age to assess
between-group differences. Senior males reported the highest time-loss (25%) and
non-time-loss (51%) for seasonal prevalence; while U-17 males reported the
lowest in both categories of groin problems (time-loss 9%, non-time-loss 27%).
No significant differences between playing position or gender were found for any
of the groin problems analyzed. In-season prevalence (9–15.7%) of groin problems
was significantly higher than pre-season (7.4%) prevalence (p<0.01). Seasonal
prevalence of groin problems is common in rink hockey, regardless of gender,
playing position, or age. Preventive efforts should be directed towards all
players, regardless of their individual characteristics.
Endoscopic Ultrasound-Guided Rendezvous Pancreatic Duct Stenting in Pancreas Divisum Using Modified Cannula
Authors: Kanjamala Kiran Josy , Zacharias Prakash , Mathew Shibi , Madhu Deepak , Ahamed Hasim , Mohmed Bilal , Philip Mathew
Published: February 2024

This video is of a 65 year old female patient with history of systemic hypertension, type 2 diabetes and coronary artery disease on medical management. She presented with features of acute pancreatitis which was managed conservatively and imaging showed features of chronic pancreatitis with dilated pancreatic duct and pancreas divisum was suggested. She had two further episodes of acute pancreatitis and was managed conservatively. Pancreatic stenting was suggested but during ERCP minor papillae couldn't be identified. Hence, EUS guided Rendez - vous pancreatic duct puncture and minor papillae stenting was done with the help of a modified cannula.
Fault detection and identification in induction motor using weightless neural network
Authors: Abid Anam , Zo Afshan
Published: February 2024

This paper presents a novel multiclass, multiparameter real-valued weightless neural network-based classifier for fault detection and identification. In contrast to primitive variants of weightless neural nets, the proposed method is capable of multiclass identification with real-valued input features and has improved recognition and generalization capabilities. The major accomplishments of the proposed method include an improved input-to-address mapping strategy that is suitable for address assignment within discriminator units and an effective memory expansion scheme based on similarity metric-based membership value. The developed classifier is utilized for fault detection and identification in single-phase and three-phase induction motors. The sensitivity analysis of the method is investigated for design parameter variation and the fault diagnosis is performed for multiple faults of the motor. The proposed method achieves the highest accuracy of 99.6% and 89.25% for single-phase and three-phase induction motor fault identification, respectively.
Theory of moment propagation for quantum dynamics in single-particle description
Authors: Boyer Nicholas J. , Shepard Christopher , Zhou Ruiyi , Xu Jianhang , Kanai Yosuke
Published: February 2024

We present a novel theoretical formulation for performing quantum dynamics in terms of moments within the single-particle description. By expressing the quantum dynamics in terms of increasing orders of moments, instead of single-particle wave functions as generally done in time-dependent density functional theory, we describe an approach for reducing the high computational cost of simulating the quantum dynamics. The equation of motion is given for the moments by deriving analytical expressions for the first-order and second-order time derivatives of the moments, and a numerical scheme is developed for performing quantum dynamics by expanding the moments in the Taylor series as done in classical molecular dynamics simulations. We propose a few numerical approaches using this theoretical formalism on a simple one-dimensional model system, for which an analytically exact solution can be derived. The application of the approaches to an anharmonic system is also discussed to illustrate their generality. We also discuss the use of an artificial neural network model to circumvent the numerical evaluation of the second-order time derivatives of the moments, as analogously done in the context of classical molecular dynamics simulations.
Nonreciprocity in cavity magnonics at millikelvin temperature
Authors: Kim Mun , Tabesh Armin , Zegray Tyler , Barzanjeh Shabir , Hu Can-Ming
Published: February 2024

Incorporating cavity magnonics has opened up a new avenue in controlling non-reciprocity. This work examines a yttrium iron garnet sphere coupled to a planar microwave cavity at millikelvin temperature. Non-reciprocal device behavior results from the cooperation of coherent and dissipative coupling between the Kittel mode and a microwave cavity mode. The device’s bi-directional transmission was measured and compared to the theory derived previously in the room temperature experiment. Investigations are also conducted into key performance metrics such as isolation, bandwidth, and insertion loss. The findings point to the coexistence of coherent and dissipative interactions at cryogenic conditions, and one can leverage their cooperation to achieve directional isolation. This work foreshadows the application of a cavity magnonic isolator for on-chip readout and signal processing in superconducting circuitry.
Design of a 140 GHz waveguide notch filter for millimeter-wave receiver module protection in fusion plasma diagnostics
Authors: Qiu Shasha , Himes Logan , Domier Calvin , Tang Xiaopin , Liu Xianzi , Hu Fengqi , Yu Guanying , Li Xiaoliang , Zhu Yilun , Luhmann Neville , Xie Jinlin , Wu Zhengwei
Published: February 2024

A carefully designed waveguide-based millimeter-wave notch filter, operating at 140 GHz, safeguards plasma diagnostic instruments from gyrotron leakage. Utilizing cylindrical cavity resonators with aperture coupling, the filter efficiently resonates 140 GHz wave-power into the TE11p mode, optimizing various geometrical parameters for practical fabrication and high-yield production. Thorough thermal analysis ensures its ability to handle power. The filter achieves outstanding performance with over 90 dB rejection at 140 GHz while providing low insertion loss over the passband (110–138 GHz), which is ideally suited for system-on-chip approach F-band diagnostic system applications.
Development and analysis of two-dimensional point-ahead angle mechanism for space gravitational-wave detection
Authors: Zhu Weizhou , Xie Yong , Qian Yuchen , Jia Jianjun , Zhang Liang , Wang Xue
Published: February 2024

To detect low-frequency gravitational waves, it is necessary to eliminate the interference of geo-noise and build a laser interference gravitational-wave detection device in space. Space gravitational-wave detection missions, namely Taiji, LISA, and Tianqin, have been planning to achieve picometer sensitivity on an interferometer arm of several million kilometers to meet the gravitational-wave detection requirements. Because of the orbit evolution and the time delay in interferometer arms, the direction of the transmitted laser beam changes; consequently, a remote telescope cannot receive the laser beam to complete the inter-satellite laser interference. In this study, a two-dimensional point-ahead angle mechanism (2DPAAM) is designed and demonstrated to solve the aforementioned problem. Based on the design concept of aligning the rotation center with the mirror surface center, the 2DPAAM employs a four-link flexible-hinge structure, length expanding and contracting piezoelectric stack actuators, and closed-loop control of capacitive sensors to realize two-dimensional picometer-stable, high-precision rotation. A static model is established to analyze the rotational characteristics, and finite element analysis is performed to study the mechanical properties and to verify the rotational characteristics. The yaw and pitch stiffness errors are ∼0.93% and 5.9%, respectively, when the theoretical results are compared with the simulation results. A series of experiments are conducted on the developed 2DPAAM, and the results show that the rotary ranges of yaw and pitch motions attain ±270 and ±268 µrad, respectively. The rotational accuracies of both yaw and pitch motions attain ∼0.35 µrad, and the optical path difference is less than 10pm/Hz when the frequency is between 1 mHz and 1 Hz, by analogy.
Salinity gradient power generation in sinusoidal nanochannels
Authors: Li Changzheng , Li Zhenquan , Zhang Zhe , Qiao Nan , Liao Mengzhen
Published: February 2024

Salinity gradient power generation based on nanochannels has drawn much attention for its green and sustainable advantages. However, previous studies have tended to focus on regularly shaped nanochannels, while rough and irregular surfaces are naturally formed during the preparation of nanochannels (similar to sinusoidal nanochannels). In this paper, a model of salinity gradient energy conversion in sinusoidal nanochannels is established. The impacts of the geometrical parameter dimensions of the sinusoidal channel (including initial phase, channel length, average radius, amplitude, and angular frequency) on the power generation performance under different salinity gradients are systematically investigated. The results show that the sinusoidal nanochannel has better salinity gradient power generation performance than cylindrical nanochannel. It obtains the best power generation performance when the initial phase is zero. Besides, increasing the nanochannel length facilitates ion selectivity and energy conversion efficiency. At high concentration difference, decreasing the average radius or increasing the amplitude help increase the maximum output power and enhance the energy conversion efficiency. The maximum output power of about 1.27 pW and energy conversion efficiency of about 32.8% were obtained by optimizing the sinusoidal channel amplitudes. It is also found that increasing the angular frequency is favorable to improving energy conversion performance at the high concentration difference. These results provide helpful information for designing and optimizing salinity gradient energy conversion systems.
Second harmonic generation for estimating state of charge of lithium-ion batteries
Authors: Sun Hongbin , Ramuhalli Pradeep , Amin Ruhul , Belharouak Ilias
Published: February 2024

This study applied the nonlinear ultrasonic method, second harmonic generation, to precisely estimate the state of charge (SoC) in lithium-ion batteries. The second harmonic of the longitudinal wave is generated on a pouch cell battery at 5 MHz with a through-transmission setup. The relative nonlinear parameter β′ is determined by analyzing the amplitudes at the fundamental and second harmonic frequencies. To enhance the nonlinear parameter's measurement accuracy, multiple excitation amplitudes are employed. Two separate charge/discharge tests (four-cycle and eight-cycle) are conducted on the battery at a rate of C/10. The nonlinear parameter is measured periodically during the charge/discharge process, and temperature compensation is applied to the measurement. The correlation curves between the nonlinear parameter and the actual SoC align well for the four-cycle and eight-cycle tests, and a robust linear relationship is observed for both correlation curves. A linear model and a second-order polynomial model are applied to fit the correlation using all data points from both tests. The two models are employed to validate the SoC prediction on a second battery by using a four-cycle test. The results indicate that both models can predict the SoC with an accuracy of approximately 3%, whereas the polynomial model demonstrates smaller errors in the regions near 0% and 100% SoC. Therefore, the nonlinear parameter β′, measured through the second harmonic generation, can effectively predict lithium-ion battery SoC with an accuracy of less than 3%.
Correlation-induced viscous dissipation in concentrated electrolytes
Authors: Robin Paul
Published: February 2024

Electrostatic correlations between ions dissolved in water are known to impact their transport properties in numerous ways, from conductivity to ion selectivity. The effects of these correlations on the solvent itself remain, however, much less clear. In particular, the addition of salt has been consistently reported to affect the solution’s viscosity, but most modeling attempts fail to reproduce experimental data even at moderate salt concentrations. Here, we use an approach based on stochastic density functional theory, which accurately captures charge fluctuations and correlations. We derive a simple analytical expression for the viscosity correction in concentrated electrolytes, by directly linking it to the liquid’s structure factor. Our prediction compares quantitatively to experimental data at all temperatures and all salt concentrations up to the saturation limit. This universal link between the microscopic structure and viscosity allows us to shed light on the nanoscale dynamics of water and ions under highly concentrated and correlated conditions.
Numerical prediction of cavitation nuisance on hydrofoils: Combined analysis of cavity dynamics and the aggressiveness of collapsing cavitating structures
Authors: Hong Feng , Lei Enhong , Xue Huancheng , Xiang Kexin , Shao Zhewen , Jia Jinping , Huang Yingping
Published: February 2024

The unsteady cavitating flow past a three-dimensional twisted hydrofoil is numerically investigated by a large eddy simulation to obtain in-depth insight into the bubble dynamics near the cavitation erosion region. Macroscopic cavity evolution is captured by a multiphase flow computing frame, while the bubble oscillations in the cavitating flow are computed by solving the Gilmore bubble dynamic model, in which the driving force for the bubble movement is exported through the application of a discrete phase model. The cavitation erosion potential is then computed by a robust indicator developed based on the energy balance hypothesis. The relevance between the dynamics and the destructive essence of a cavitation bubble and the erosion intensity is thoroughly analyzed. The results show that the unsteadiness involved in the turbulent cloud cavitation is well reproduced, and the main cavitation erosion risk in the middle region of the hydrofoil is also accurately predicted comparing with the painting test results. A localized high-pressure region is identified near the rear part of the attached cavity where the mainstream encounters the primary reentrant jet flows. The peak bubble internal pressure can reach 487 MPa near the middle plane of the hydrofoil, during the stage when the surrounding liquid pressure is continuously increased. The bubbles with the smallest radius, ranging from 23.1 to 26.3 μm after compressing from their initial sizes (R0 = 100–700 μm) in the near wall region, are associated with the extremely high internal pressure, and they are responsible for the cavitation erosion damage on the hydrofoil surface.
Asymmetric membrane “sticky tape” enables simultaneous relaxation of area and curvature in simulation
Authors: Foley Samuel L. , Deserno Markus
Published: February 2024

Biological lipid membranes are generally asymmetric, not only with respect to the composition of the two membrane leaflets but also with respect to the state of mechanical stress on the two sides. Computer simulations of such asymmetric membranes pose unique challenges with respect to the choice of boundary conditions and ensemble in which such simulations are to be carried out. Here, we demonstrate an alternative to the usual choice of fully periodic boundary conditions: The membrane is only periodic in one direction, with free edges running parallel to the single direction of periodicity. In order to maintain bilayer asymmetry under these conditions, nanoscale “sticky tapes” are adhered to the membrane edges in order to prevent lipid flip-flop across the otherwise open edge. In such semi-periodic simulations, the bilayer is free to choose both its area and mean curvature, allowing for minimization of the bilayer elastic free energy. We implement these principles in a highly coarse-grained model and show how even the simplest examples of such simulations can reveal useful membrane elastic properties, such as the location of the monolayer neutral surface.
Simulation of flow and debris migration in extreme ultraviolet source vessel
Authors: Meng Wen-Sheng , Zhao Chao-Ben , Wu Jian-Zhao , Wang Bo-Fu , Zhou Quan , Chong Kai Leong
Published: February 2024

Practical extreme ultraviolet (EUV) sources yield the desired 13.5 nm radiation but also generate debris, significantly limiting the lifespan of the collector mirror in lithography. In this study, we explore the role of buffer gas in transporting debris particles within an EUV source vessel using direct numerical simulations. Our study involves a 2 × 1 × 1m3 rectangular cavity with an injecting jet flow subjected to sideward outlet. Debris particles are introduced into the cavity with specified initial velocities, simulating a spherical radiating pattern with particle diameters ranging from 0.1 to 1 μm. Varying the inflow velocity (from 1 to 50 m/s) of the buffer gas reveals a morphological transition in the flow field. At low inflow velocities, the flow remains steady, whereas higher inflow velocities induce the formation of clustered corner rolls. Upon reaching sufficiently high inflow velocities, the jet flow can penetrate the entire cavity, impacting the end wall. Interestingly, the resulting recirculation flow leads to the spontaneous formation of spiraling outflow. The distinct flow structures at various inflow velocities lead to distinct patterns of particle transport. For low-speed gas, it is efficient in expelling all particles smaller than 0.4 μm, while for high-speed gas, those fine particles accumulate near the end wall and are challenging to be extracted. Our findings highlight the significance of controlling flow conditions for effective debris particle transport and clearance in diverse applications especially in EUV source vessels.
Phonon modes controlled by primary chemical structure of partially fluorinated dimyristoylphosphatidylcholine (DMPC) revealed by multiple-angle incidence resolution spectrometry (MAIRS)
Authors: Hasegawa Takeshi , Nakagawara Ai , Takagi Toshiyuki , Shimoaka Takafumi , Shioya Nobutaka , Sonoyama Masashi
Published: February 2024

Partially fluorinated dimyristoylphosphatidylcholines (DMPCs) involving double alkyl chains are employed to control the phonon generation in thin films, which is examined by infrared (IR) spectroscopy coupled with multiple-angle incidence resolution spectrometry (MAIRS). technique. Compounds having perfluoroalkyl (Rf) chains are known to exhibit phonon bands in IR spectra because of the strong dipole–dipole interactions. Since the phonon bands of an organic matter have a similar shape to the normal absorption bands, however, recognition of the phonon modes is difficult and confusing for IR spectroscopists. Here, we show that MAIRS works out for finding phonon modes in monolayers: the Berreman shift is readily captured by the MAIRS in-plane and out-of-plane (OP) spectra. By measuring the longitudinal-optic (LO) energy-loss function spectrum of a bulk sample, the degree of molecular aggregation in the monolayer is also revealed by comparing the OP spectrum of the monolayer to the LO one. In addition, partially fluorinated DMPC compounds having both hydrocarbon and Rf chains are prepared, and they are used to obstruct the self-aggregation of the Rf groups in the film. As a result, the phonon characteristics are mostly lost in the MAIRS spectra as expected.
Automated potential energy surface development and comprehensive dynamics for the F + CH3NH2 reaction
Authors: Szűcs Tímea , Czakó Gábor
Published: February 2024

This work is an extensive investigation of the F + CH3NH2 reaction dynamics using a newly-developed potential energy surface (PES). The full-dimensional spin–orbit (SO) corrected (MRCI+Q/aug-cc-pwCVDZ) PES is developed by the Robosurfer program package and the ManyHF method is used in order to fix the Hartree–Fock (HF) convergence issues in the entrance channel. On the surface, retrieved by the fitting of the iteratively extended set of the ManyHF-CCSD(T)-F12a/triple-zeta-quality and SO-corrected energy points, quasi-classical trajectory (QCT) simulations are run. By analyzing the opacity functions and integral cross sections (ICSs) of six reaction channels, the dynamics of the two most reactive hydrogen-abstraction reactions resulting in HF + CH2NH2/CH3NH products are selected for a thorough examination. Despite the statistically and thermodynamically expected results, the kinetically preferred amino hydrogen-abstraction is the dominant mechanism at low collision energies. The initial attack angle and scattering angle distributions are investigated as well. The post-reaction energy distributions show that the collision energy mostly converts into the translational energy of the products, while the reaction energy excites the vibration of the products. The computed vibrationally resolved rotational distributions and vibrational state distributions of the HF product are compared to experimental data, and the theory and experiment are found to be in good agreement.
Water jumps over a nanogap between two disjoint carbon nanotubes assisted by terahertz electric field
Authors: Wu Yue , Wang Zi , Li Shuang , Su Jiaye
Published: February 2024

Controlling the water permeation through carbon nanotubes (CNTs) with more complex structures holds great promise for many practical applications, such as nanometer water gates, energy collection, and biosensors. In this work, upon using extensive molecular dynamics simulations, we find a fascinating phenomenon that terahertz electric fields can more significantly stimulate the transport of a single-file water chain across two disjoint CNTs with a nanogap, where the water flow is several times to an order greater than that of static electric fields. This is because the static electric field promotes the formation of a water bridge in the nanogap region, which connects the two single-file water chains. Thus, the water molecules have to move collectively through the two CNTs, resulting in a relatively low water flow. However, under the terahertz electric field, the single-file water chain can be interrupted because of the resonant effect, and the water phase becomes vapor-like. In this case, some water molecules are partially or not hydrogen bonded and will have more freedom to move quickly through the disjoint CNTs. Consequently, the terahertz electric field is a more efficient external stimulus to promote the water permeation across the nanogap between two disjoint CNTs, which should have great implications for the design of controllable nanofluidic devices.
A versatile apparatus for simultaneous trapping of multiple species of ultracold atoms and ions to enable studies of low energy collisions and cold chemistry
Authors: Rahaman Bubai , Baidya Satyabrata , Dutta Sourav
Published: February 2024

We describe an apparatus where many species of ultracold atoms can be simultaneously trapped and overlapped with many species of ions in a Paul trap. Several design innovations are made to increase the versatility of the apparatus while keeping the size and cost reasonable. We demonstrate the operation of a three-dimensional (3D) magneto-optical trap (MOT) of 7Li using a single external cavity diode laser. The 7Li MOT is loaded from an atomic beam, with atoms slowed using a Zeeman slower designed to work simultaneously for Li and Sr. The operation of a 3D MOT of 133Cs, loaded from a 2D MOT, is demonstrated, and provisions for MOTs of Rb and K in the same vacuum manifold exist. We demonstrate the trapping of 7Li+ and 133Cs+ at different settings of the Paul trap and their detection using an integrated time-of-flight mass spectrometer. We present results on low energy neutral–neutral collisions (133Cs–133Cs, 7Li–7Li, and 133Cs–7Li collisions) and charge–neutral collisions (133Cs+–133Cs and 7Li+–7Li collisions). We show evidence of sympathetic cooling of 7Li+ (133Cs+) due to collisions with the ultracold 7Li (133Cs).
Phylogenomics of endemic Australian Ulopinae (Hemiptera: Cicadomorpha: Cicadellidae)
Authors: Evangelista Olivia , Tatarnic Nikolai , Bayless Keith
Published: February 2024

Ulopinae is a distinctive subfamily of leafhoppers that is widely distributed across the Afrotropical, Palearctic, Indomalayan and Australasian regions. The ulopine fauna of Australia is entirely endemic and includes two tribes of striking appearance, the Ulopini and Cephalelini. Knowledge of these groups is fragmentary and in many instances, no information is available beyond original descriptions. We assess the monophyly, phylogenetic placement and species-level diversity of the Ulopini genus Austrolopa. Phylogenetic analyses based on sequence data from target nuclear loci (18S, 28S, H2A and H3) and mitochondrial genomes (15 genes) for 23 membracoid taxa yielded congruent topologies. Our results provide strong evidence for the monophyly of Ulopinae and a clade consisting of Ulopini + Cephalelini. However, a non-monophyletic Cephalelini arises from within a polyphyletic Ulopini. Austrolopa was strongly recovered as monophyletic in all analyses, a result also supported by morphological features. The genus currently includes six species, three of which are described based on morphological and molecular data: Austrolopa botanica, sp. nov., Austrolopa rotunda, sp. nov. and Austrolopa sublima, sp. nov. A lectotype designation is provided for Austrolopa kingensis Evans, 1937, sp. reval. Our findings illustrate that the Australian Ulopinae is far more diverse than currently circumscribed and several species of Austrolopa are yet to be recognised. ZooBank: urn:lsid:zoobank.org:pub:1480285B-8F61-4659-A929-2B1EF3168868