bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Nonnutritive Sucking on Oral Feeding in Neonates With Perinatal Asphyxia: A Randomized Controlled Trial
Authors: Berber Çiftci Hilal , Topbaş Seyhun , Taştekin Ayhan
Published: December 2023

Aims:

The effect of nonnutritive sucking (NNS) stimulation is unclear in infants with perinatal asphyxia. Thus, the aim of this study was to assess the effect of NNS stimulation on oral intake, discharge time, and early feeding skills in infants with perinatal asphyxia.

Design:

A randomized controlled study was conducted.

Method:

Of the 94 infants, 47 were included in the experimental group and given NNS stimulation once a day before tube feeding by a speech-language therapist (SLT) in addition to hypothermia treatment. Infants' feeding performances on the days of first oral intake and discharge were evaluated with the Early Feeding Skills Scale (EFS).

Results:

The time from tube feeding to oral intake was significantly lower in the experimental group compared to the control group (
p
< .05). EFS scores at discharge were significantly higher in the experimental group than in the control group (
p
< .05). There was no significant difference between the experimental and control groups in terms of discharge and weight gain (
p
> .05).

Conclusions:

The findings indicated that the NNS stimulation positively affected oral intake and early feeding skills in infants with perinatal asphyxia, as in preterms. However, NNS stimulation had no significant effect on discharge and weight gain in infants with asphyxia. This finding may be attributed to other factors. It is recommended to use NNS by an SLT in a neonatal intensive care unit within a multidisciplinary team to accelerate the transition to oral feeding and improve feeding skills in infants with perinatal asphyxia. Further studies on the effect of NNS stimulation in infants with perinatal asphyxia are needed to corroborate its effects on discharge time and weight gain.
Energy‐efficient operation of medium‐speed maglev through integrated traction and train control
Authors: Lai Qingying , Liu Jun , Wang Yihui , Xu Hongze , Guo Shudong , Ju Miaoyu
Published: December 2023

In contrast to the wheel‐track trains, where the motor characteristics are considered a constant value, the motor characteristics of the medium‐speed maglev (MSM) trains are the dependent variable of the position. This article studies the integration of traction power control and train control for the MSM to minimize energy consumption. First, an innovative integrated energy‐efficient optimization model for MSM train control is constructed, considering the characteristics of the linear motors. Then, a multi‐level dynamic programming (DP) approach, which includes the train operation simulation with the linear motor, is developed to solve the optimization problem. Furthermore, a speed‐up strategy for the DP approach is proposed by a pre‐calculated target train speed band (TTSB). The results of numerical experiments show that the DP approach yields a more practical train speed profile. In contrast, the DP approach with the TTSB strategy can achieve a better trade‐off between solution accuracy and computational efficiency.
Harmonic oscillation analysis and stabilization method comparison of shunt active power filter in full compensation mode
Authors: Zhang Zhilong , Yi Hao , Zhuo Fang , Li YuGuo , Jiang Xin
Published: December 2023

The harmonic compensation of SAPF (shunt active power filter) may trigger harmonic oscillation due to the interaction with grid impedance and non‐linear loads, which distorts the power quality. In previous research, the relevant mechanism has been studied. However, the SAPF generally employs complex harmonic detection algorithm, which significantly increases the computational demands. The SAPF in full compensation mode can effectively solve this problem. But the modification of harmonic detection link may change the oscillation mechanism and previous stabilization methods need to be re‐evaluated. Therefore, this paper establishes the small signal model of the SAPF system in full compensation mode and investigates its oscillation mechanism. It is revealed that harmonic compensation and passive resonance collectively induce the harmonic oscillation. Based on the model, the working mechanism and application performance of the main stabilization methods proposed in the past (harmonic virtual admittance and harmonic compensation canceling) are analyzed and compared. However, neither of them can achieve effective stabilization without sacrificing the performance of compensation. Consequently, the harmonic phase compensation method is proposed to achieve the stabilization of the SAPF system in full compensation mode without affecting normal compensation. Finally, simulations and experiments are performed to verify the mechanism analysis and proposed methods.
Research on adaptive optimal control strategy of virtual synchronous generator inertia and damping parameters
Authors: Shi Tao , Sun Jin , Han Xiang , Tang Chunsheng
Published: December 2023

As the ratio of newly installed power generation utilizing power electronic converters increases, it results in a decrease in the overall inertia and damping of the power system, as well as the decrease in its ability to resist interference. Aiming to address this issue, the authors propose an adaptive optimal control approach for the parameter in the virtual synchronous generator (VSG). This strategy considers the power angle curve and analyzes the principles of inertia and damping within the oscillation period and its range of values. By coordinating the values of parameters, it achieves the optimization of these parameters. At the same time, in order to take into account the demand for fast regulation response under normal operation control conditions and the demand for synchronization support under disturbance fault conditions, a multi‐mode switching control strategy including virtual synchronization control and conventional PQ control is further proposed. Based on MATLAB/Simulink software, the strategies mentioned above have been proven through simulation. The findings testify the proposed method can significantly enhance the regulation response characteristics of the VSG by optimizing its parameters. Additionally, it enables smooth switching of the control mode independently, based on the specific requirements of different control scenarios. This approach fully leverages the virtual synchronous support and fast regulation characteristics of the power electronic converter, and has practical engineering value.
Stellar activity and differential rotation of HD 111395
Authors: Mittag M. , Schmitt J. H. M. M. , Fuhrmeister B. , Robrade J. , Schröder K.-P.
Published: December 2023

Aims. Stellar activity cycles and rotation periods are important parameters for characterising the stellar dynamo, which operates in late-type main-sequence stars. However, the number of stars with well-known cycle and rotation periods is rather low, so new detections are still important.

Methods. To find activity cycles and rotation periods, we utilised the TIGRE telescope to monitor stars for periodic variations in chromospheric activity indicators. We employed the widely used CaII H&K lines and the CaII infrared triplet lines as stellar activity indicators. To verify a periodic variation and to determine the corresponding period, we performed a frequency analysis via the generalised Lomb-Scargle method of the taken time series.

Results. We studied CaII data of the G5V star HD 111395 and derive an activity cycle period of 949 ± 5 d (≈2.6 yr). This cycle is coincident with coronal measurements from the X-ray telescope eROSITA on board SRG. Furthermore, the TIGRE CaII time series show a long-term trend that indicates an additional long-term cycle. Using the few available literature S-index data points, we estimate a probable cycle length of 12–15 yr for this potential long-term cycle. Finally, we determined rotation periods from each observation season. We computed a mean rotation period of 16.76 ± 0.36 d averaged over all observation seasons and chromospheric indicators. However, we also find a strong variation in the mean seasonal rotation periods, which follows the derived cycle period; therefore, we interpret this behaviour as a sign of surface differential rotation.
Observational evidence to support a dense ambient medium shaping the jet in 3C 84
Authors: Park Jongho , Kino Motoki , Nagai Hiroshi , Nakamura Masanori , Asada Keiichi , Kam Minchul , Hodgson Jeffrey A.
Published: December 2023

Highly collimated relativistic jets are a defining feature of certain active galactic nuclei (AGN), yet their formation mechanism remains elusive. Previous observations and theoretical models have proposed that the ambient medium surrounding the jets could exert pressure, playing a crucial role in shaping the jets. However, a direct observational confirmation of such a medium has been lacking. In this study, we present very long baseline interferometric (VLBI) observations of 3C 84 (NGC 1275), located at the center of the Perseus Cluster. Through monitoring observations with the Very Long Baseline Array (VLBA) at 43 GHz, a jet knot was detected to have been ejected from the sub-parsec scale core in the late 2010s. Intriguingly, this knot propagated in a direction significantly offset from the parsec-scale jet direction. To delve deeper into the matter, we employed follow-up VLBA 43 GHz observations, tracing the knot’s trajectory until the end of 2022. We discovered that the knot abruptly changed its trajectory in the early 2020s, realigning itself with the parsec-scale jet direction. Additionally, we present results from an observation of 3C 84 with the Global VLBI Alliance (GVA) at 22 GHz, conducted near the monitoring period. By jointly analyzing the GVA 22 GHz image with a VLBA 43 GHz image observed about one week apart, we generated a spectral index map, revealing an inverted spectrum region near the edge of the jet where the knot experienced deflection. These findings suggest the presence of a dense, cold ambient medium characterized by an electron density exceeding ∼105 cm−3, which guides the jet’s propagation on parsec scales and significantly contributes to the overall shaping of the jet.
The GUAPOS project: G31.41+0.31 Unbiased ALMA sPectral Observational Survey
Authors: Fontani F. , Mininni C. , Beltrán M. T. , Rivilla V. M. , Colzi L. , Jiménez-Serra I. , López-Gallifa Á. , Sánchez-Monge Á. , Viti S.
Published: December 2023

Context. The astrochemistry of the important biogenic element phosphorus (P) is still poorly understood, but observational evidence indicates that P-bearing molecules are likely associated with shocks.

Aims. We study P-bearing molecules and some shock tracers towards one of the chemically richest hot molecular cores, G31.41+0.31, in the framework of the project “G31.41+0.31 Unbiased ALMA sPectral Observational Survey” (GUAPOS), which is being carried out with the Atacama Large Millimeter Array (ALMA).

Methods. We observed the molecules PN, PO, SO, SO2, SiO, and SiS through their rotational lines in the spectral range 84.05– 115.91 GHz covered by the GUAPOS project.

Results. PN is clearly detected, while PO is tentatively detected. The PN emission arises from two regions southwest of the hot core peak, named regions 1 and 2 here, and is undetected or tentatively detected towards the hot core peak. The PN and SiO lines are very similar both in spatial emission morphology and spectral shape. Region 1 is partly overlapping with the hot core and is warmer than region 2, which is well separated from the hot core and located along the outflows identified in previous studies. The SO, SO2, and SiS emissions are also detected towards the PN-emitting regions 1 and 2, but arise mostly from the hot core. Moreover, the column density ratio SiO/PN remains constant in regions 1 and 2, while SO/PN, SiS/PN, and SO2/PN decrease by about an order of magnitude from region 1 to region 2, indicating that SiO and PN have a common origin even in regions with different physical conditions. The PO/PN ratio in region 2, where PO is tentatively detected, is ~0.6–0.9, which is in line with the predictions of pure shock models.

Conclusions. Our study provides robust confirmation of previous observational evidence that PN emission is tightly associated with SiO and is likely a product of shock chemistry, as the lack of a clear detection of PN towards the hot core allows us to rule out relevant formation pathways in hot gas. We propose the PN-emitting region 2 as a new astrophysical laboratory for shock-chemistry studies.
Light curves and spectra for theoretical models of high-velocity red-giant star collisions
Authors: Dessart Luc , Ryu Taeho , Amaro Seoane Pau , Taylor Andrew M.
Published: December 2023

High-velocity stellar collisions driven by a supermassive black hole (BH) or BH-driven disruptive collisions in dense, nuclear clusters can rival the energetics of supergiant star explosions following the gravitational collapse of their iron core. Starting from a sample of red-giant star collisions simulated with the hydrodynamics code AREPO, we generated photometric and spectroscopic observables using the nonlocal thermodynamic equilibrium time-dependent radiative transfer code CMFGEN. Collisions from more extended giants or more violent collisions (with higher velocities or smaller impact parameters) yield bolometric luminosities on the order of 1043 erg s−1 at 1 d, evolving on a timescale of a week to a bright plateau at ∼1041 erg s−1 before plunging precipitously after 20–40 d at the end of the optically thick phase. This luminosity falls primarily in the UV in the first few days, thus when it is at its maximum, and shifts to the optical thereafter. Collisions at lower velocities or from less extended stars produce ejecta that are fainter but can remain optically thick for up to 40 d if they have a low expansion rate. This collision debris shows a similar spectral evolution as that observed or modeled for Type II supernovae from blue-supergiant star explosions, differing only in the more rapid transition to the nebular phase. Such BH-driven disruptive collisions should be detectable by high-cadence surveys in the UV such as ULTRASAT.
Chemistry Nobel Prize Celebrates Colloidal Quantum Dots: Highly-Engineered, Spectrally Pure Light
Authors: Lhuillier Emmanuel , Steckel Jonathan S. , Livache Clément , Reiss Peter
Published: December 2023

The Chemistry Nobel Prize of this year has been awarded to Alexei Ekimov, Luis Brus, and Moungi Bawendi for their significant contributions to the discovery and synthesis of colloidal quantum dots. What initially started as a strategy to explore the physics of reduced dimensionality in matter has transitioned over the past 40 years into a commercially available technology platform, the largest of which provides red and green color sources for displays. In this overview, we will delve into this transition process and the pivotal roles played by the laureates.
“Should Pediatric Septal Surgery and Septorhinoplasty Be Performed for Nasal Obstruction?”—A Systematic Review of the Literature
Authors: Howard Theodore , Williams Isabelle , Navaratnam Annakan , Haloob Nora , Stoenchev Kostadin , Saleh Hesham
Published: December 2023

Corrective septal surgery for children with nasal obstruction has historically been avoided due to concern about the impact on the growing nose, with disruption of midfacial growth. However, there is a paucity of data evaluating complication and revision rates post-nasal septal surgery in the pediatric population. In addition, there is evidence to suggest that failure to treat nasal obstruction in children may itself result in facial deformity and/or developmental delay. The aim of this systematic review is to evaluate the efficacy and safety of septal surgery in pediatric patients with nasal obstruction. A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. MEDLINE, Embase, and the Cochrane Library were searched. Original studies in pediatric patients (<18 years of age) with nasal obstruction were eligible for inclusion. Patients with cleft lip or palate as their primary diagnosis were excluded. Our primary outcomes were patient-reported outcome measures (PROMs), postsurgical complications, and revision rates. Secondary outcomes included surgical technique, anatomical considerations, and anthropometric measurements. Eighteen studies were included (1,080 patients). Patients underwent septoplasty, septorhinoplasty, rhinoplasty, or a combination of procedures for nasal obstruction. Obstruction was commonly reported secondary to trauma, nasal septal deviation, or congenital deformity. The mean age of the patients was 13.04 years with an average follow-up of 41.8 months. In all, 5.6% patients required revision surgery and there was an overall complication rate of 7.8%. Septal surgery for nasal obstruction in children has low revision and complication rates. However, a pediatric-specific outcome measure is yet to be determined. Larger prospective studies with long-term follow-up periods are needed to determine the optimal timing of nasal surgery for nasal obstruction in the pediatric population.
Dual Microscope Indocyanine Green Video Angiography and Endoscopic Review to Treat Intracranial Aneurysm: A Review of the Literature Regarding a Case
Authors: Vega-Moreno Daniel Alejandro , Janković Dragan , Azouz Heba , Nakipuria Mayank , Kato Yoko
Published: December 2023

The use of the indocyanine green video angiography (ICG-VA) both endoscope and microscope has become popular in recent decades thanks to the safety, efficacy, and added value that they have provided for cerebrovascular surgery. The dual use of these technologies is considered complementary and has helped cerebrovascular surgeons in decision-making, especially for aneurysm clipping surgery; however, its use has been described for both aneurysm surgery, resection of arteriovenous malformations, or even for bypass surgeries. We conducted a review of the literature with the MeSH terms “microscope indocyanine green video angiography (mICG-VA),” “endoscopic review,” AND/OR “intracranial aneurysm.” A total of 97 articles that included these terms were selected after a primary review to select a total of 26 articles for the final review. We also present a case to exemplify its use, in which we use both technological tools for the description of the aneurysm, as well as for decision-making at the time of clipping and for reclipping. Both tools, both the use of the endoscope and the mICG-VA, have helped decision-making in neurovascular surgery. A considerable clip replacement rate has been described with the use of these technologies, which has helped to reduce the complications associated with poor clipping. One of the main advantages of their usefulness is that they are tools for intraoperative use, which is why they have shown superiority compared to digital subtraction angiography, which takes longer to use and has a higher risk of complications associated with the contrast medium. On the other hand, a very low rate of complications has been described with the use of the endoscope and mICG-VA, which is why they are considered safe tools to use. In some cases, mention has been made of the use of one or the other technology; however, we consider that its dual use provides more information about the status of the clip, its anatomy, its relationship with other vascular structures, and the complete occlusion of the aneurysm. We consider that the use of both technologies is complementary, so in case of having them both should be used, since both the endoscope and the mICG-VA provide additional and useful information.
In search of a reciprocal relationship in dessert cafés: linking customer perceived innovativeness to value co-creation behavior
Authors: Ling Esther Sii Wei , Chua Bee-Lia , Han Heesup
Published: December 2023

This study examined a conceptual model encompassing perceived innovativeness, perceived values, attitude, and customer value co-creation behavior in the context of dessert cafés. An online survey was conducted with customers of dessert café chains based in Malaysia. The results indicated that menu innovativeness had the highest contribution to perceived innovativeness, followed by experiential innovativeness. The study found that perceived innovativeness improved the value of money, evoked positive emotions, and enhanced social image. In highly innovative dessert cafés, positive emotions led to a positive attitude and, in turn, increased willingness to co-create value. This study provides valuable insights for dessert café businesses by emphasizing the need to foster innovation and create emotionally satisfying experiences to enhance customer engagement in co-creation activities.
A typology of the climate activist
Authors: Kirsop-Taylor Nick , Russel Duncan , Jensen Anne
Published: December 2023

As the climate crisis escalates and citizens increasingly come to understand the existential consequences of political inaction on our civilisation, they are demanding radical action. Although people are mobilising as climate activists in ever more creative and imaginative ways, our understandings about the variety of inside and outside climate activism lack conceptual clarity. Every year there are new accounts from different academic literatures about climate activists and their role in the vital politics of climate change. This paper argues that now is an appropriate time to draw together these accounts and begin a process of articulating a clearer sense of the contemporary climate activist. This paper offers an initial contribution to the endeavour by synthesising across literature a unified conception of the climate activist typologised in terms of their focal orientations and the theories of change they operate under. Utilising a matrix approach, it is argued that the climate activist seeks change relative to a specific endogenous or exogenous focus. Further, that climate activists orientate around collaborative or confrontational theories of change leading to 16 theorised-proposed mutually inclusive types of climate activists.
Public risk perception of covid-19 transmission and support for compact development
Authors: Grover Himanshu
Published: December 2023

In the last few decades, there has been a definitive shift in public support for compact development – characterized by high densities, more multifamily residential use, and effective public transit. The allure of compact development is because, along with sustainability benefits, it offers multiple lifestyle benefits, such as more significant opportunities for socialization and easy access to amenities. Greater possibilities of frequent and longer interpersonal interactions attract residents to such communities. However, given the recent pandemic, it is logical to be concerned about how future public support for compact development may change. This study analyzes data from a national online survey (n = 1100) conducted in the United States toward the end of the COVID-19 pandemic (April 2022). This research aims to assess the relationship between perceived concern for COVID-19 transmission and public support for compact development. The results from SEM analysis suggest that people more concerned about COVID-19 transmission are less supportive of compact development policies. People from areas with higher density and more COVID-19 cases are likely to have greater concern for COVID-19 transmission, which may decrease support for compact development in these areas (mediated relationship). Individuals who rely on news, online media, friends or family for COVID-19 information and single-family residents are also less likely to support compact development. In contrast, while older adults are likely to have higher concern for COVID-19 transmission, they are likely to support compact development. Higher-income households are less likely to be concerned about COVID-19 transmission but are more supportive of compact development. These findings suggest that the perceived threat of disease transmission will likely result in decreased public support for compact development. To ensure continued public support, urban policymakers must allay public fear of virus transmission in compact built environments by incorporating public health measures for controlling virus transmission in compact urban environments.
Hybrid suction/blowing actuator to control flow separation on the ramp and energy cost analysis
Authors: Pour Razzaghi Mohammad Javad , Rezaei Sani Seyed Mojtaba , Musa Omer , Masoumi Yasin , Huang Guoping
Published: December 2023

The flow separation control on an adverse-pressure-gradient ramp model is studied using various flow control strategies. Using a steady turbulent flow, the effects of utilizing an active hybrid control (suction and blowing) on the separation bubble behind a ramp are investigated numerically. A parametric analysis is conducted in which the actuators' pitch angle, diameter, and streamwise position are varied. The results are compared to determine the most effective method for compensating adverse pressure gradients and managing the separated flows on a ramp model. The best results for the blowing scenario correspond to a blowing actuator with a dimensionless distance of Lx/L1=−1/70 from the top of the ramp, a dimensionless diameter of d/L1=1/70, and a dimensionless angle of θ/θ0=2/6. The actuator is found to be able to wipe out the separation zone entirely at a velocity ratio of 3. The best results for the suction approach belong to a suction actuator with Lx/L1=1+1/70 from the top of the ramp, d/L1=3/70, and θ/θ0=−4/6. The modeling shows that the actuator removes the separation zone at a lower velocity ratio, namely, at 1.5. Nonetheless, a recirculation zone forms behind the suction point. Using a combined system, with a velocity ratio of 0.5 for a diameter of 3 and 2 for a diameter of 1, eliminates the separation zones on the ramp and after the suction actuator while lowering energy consumption. The blowing actuator consumed 3.2 times as much power as the combined actuator, whereas the suction actuator consumed 1.2 times as much power. Therefore, analyzing the present results as a prerequisite makes it possible to reduce flow separation and its adverse effects in more practical environments such as airfoils with an optimal cost.
A novel on-line microwave diagnostic for an atmospheric pressure air plasma based on an artificial neural network
Authors: Chen Wenqi , Wu Li , Zhong Yu , Yu Yutian , Zhang Zhuoyue , Huang Kama
Published: December 2023

Permittivity is an important aspect of the design of microwave devices. In order to design microwave devices that are more suitable for the excitation of air plasmas, this paper presents a method for the on-line measurement of the relative permittivity of an atmospheric pressure air plasma with 2.45 GHz microwaves. First, a ridged waveguide is designed and constructed to excite the air. Using the ridged waveguide, the plasma can be excited and measured simultaneously. An artificial neural network trained with simulated data is integrated into the system to invert the dielectric constant of the air plasma being measured. At a power of 786 W and an airflow rate of 1250 L/h, the real and imaginary parts of the permittivity are obtained to be −1244 and 60, respectively. The forecasted errors on the real part and the imaginary part of the relative permittivity are kept at around 5% and 3%. The Drude model is used to construct a relationship between the electronic and dielectric properties. This diagnostic method is simple to operate and has a high degree of generality. It should be useful in the design of microwave plasma devices and can greatly improve the efficiency of microwave plasma equipment.
Predictive model of back-wall overpressure behind a cantilever wall
Authors: Xie Quanmin , Nian Xinzhe , Zhou Hui , Wu Jianyuan
Published: December 2023

To reduce the hazards posed by blast shock waves, important potential targets are usually shielded by cantilever walls. The main factor that indicates whether there is damage is the back-wall overpressure, and of concern here is predicting the back-wall overpressure behind a rigid cantilever wall. This was measured in full-scale blast experiments using 20 kg of trinitrotoluene (TNT) located on the ground, and the experimental data reveal how the cantilever wall mitigates the shock wave. A 3D numerical model was established to determine how the wall size influences the diffraction of the shock wave and the peaks and attenuation of the back-wall overpressure. Based on the numerical results and dimensional analysis, a model is proposed that provides an effective means of predicting the back-wall overpressure rapidly from the TNT equivalent, the standoff distance, and the height of the wall.
Effect of plasmon excitations in relativistic quantum electron gas
Authors: Akbari-Moghanjoughi M.
Published: December 2023

In this research, we use the generalized quantum multistream model to describe collective qusiparticle excitations in electron gas with arbitrary degree of degeneracy and relativity. The effective Schrödinger–Poisson and square-root Klein–Gordon–Poisson models are applied to study the energy band structure and statistical parameters of finite temperature quantum and relativistic quantum electron gas in neutralizing background charge. Based on the plasmon energy bandgap appearing above the Fermi level, a new equation of state for quasiparticle (collective) excitations with new plasma parameter definition is suggested for dense plasmas applicable to a wide range of electron temperature and density. The new criterion for quasiparticle excitations reveals some interesting aspects of relativistic quantum matter at extreme condition, such as the plasmon blackout and collective quantum pressure collapse, which are studied in the frameworks of both non-relativistic and relativistic quantum phenomena. Current quasiparticle model predicts density-temperature regimes in warm-dense matter for which collective excitations become ineffective. On the other hand, the energy band structure model predicts the quasiparticle pressure collapse in temperature–density regime close to that of white dwarf stars. The energy band structure is a powerful concept in condensed matter physics and is shown to have applications for collective quantum excitations in electron gas. It can also have direct applications in quasiparticle dielectric response and thermodynamic properties of electron gas in inertial confinement fusion, stellar core, compact stars, and charged relativistic quantum environments. It is interesting that the basic thermodynamic behavior of non-relativistic and relativistic quantum electron gases closely match up to temperature and number density of typical white dwarfs where the gravitational collapse is prone to occur. This evidently confirms the relevance of non-relativistic quantum plasmon model to study the collective excitations in warm dense matter and white dwarfs.
Reworking the Tao–Mo exchange-correlation functional. I. Reconsideration and simplification
Authors: Francisco H. , Cancio A. C. , Trickey S. B.
Published: December 2023

The revised, regularized Tao–Mo (rregTM) exchange-correlation density functional approximation (DFA) [A. Patra, S. Jana, and P. Samal, J. Chem. Phys. 153, 184112 (2020) and Jana et al., J. Chem. Phys. 155, 024103 (2021)] resolves the order-of-limits problem in the original TM formulation while preserving its valuable essential behaviors. Those include performance on standard thermochemistry and solid data sets that is competitive with that of the most widely explored meta-generalized-gradient-approximation DFAs (SCAN and r2SCAN) while also providing superior performance on elemental solid magnetization. Puzzlingly however, rregTM proved to be intractable for de-orbitalization via the approach of Mejía-Rodríguez and Trickey [Phys. Rev. A 96, 052512 (2017)]. We report investigation that leads to diagnosis of how the regularization in rregTM of the z indicator functions (z = the ratio of the von-Weizsäcker and Kohn–Sham kinetic energy densities) leads to non-physical behavior. We propose a simpler regularization that eliminates those oddities and that can be calibrated to reproduce the good error patterns of rregTM. We denote this version as simplified, regularized Tao–Mo, sregTM. We also show that it is unnecessary to use rregTM correlation with sregTM exchange: Perdew–Burke–Ernzerhof correlation is sufficient. The subsequent paper shows how sregTM enables some progress on de-orbitalization.
A new design method for the vortex hydrogen circulating pump system
Authors: Li Ji-Qiang , Leng Cheng-Lin , Kwon Jeong-Tae
Published: December 2023

Against the backdrop of “carbon peak and carbon neutrality,” the hydrogen and fuel cell vehicle industry are rapidly developing. Within the on-board hydrogen supply system, the hydrogen circulation pump serves as an essential component of the hydrogen fuel cell system. The spiral disk, as a core part of the hydrogen fuel cell system’s vortex hydrogen circulation pump (VHCP), plays a crucial role in determining the performance of the hydrogen circulation system in hydrogen fuel cell vehicles. To meet the requirements for high-performance and high-reliability development of the hydrogen circulation pump, the VHCP scheme is adopted as the choice for the hydrogen pump solution. Through the magnetic suspension and no connection shaft structural design, the feasibility of applying the high speed and high flow hydrogen turbine was initially validated. Utilizing Fluent analysis software and high precision performance test bench, a comprehensive three-dimensional numerical simulation of the turbine design under various operating conditions was conducted and performance test verification, demonstrating that the performance meets the required specifications. By conducting research in both strength optimization design and performance requirement, two major technical challenges in turbine pump application were overcome. Combined with the experimental results of the turbine medium, it is concluded that the vortex pump can meet the flow and pressure rise under the premise of low power consumption in the hydrogen circulation system so as to perfectly increase the hydrogen return amount. Based on these findings, recommendations are proposed for the future development direction of hydrogen supply systems in hydrogen fuel cell vehicles.
Advancing magnetic material discovery through machine learning: Unveiling new manganese-based materials
Authors: Khatri Yogesh , Kashyap Arti
Published: December 2023

Magnetic materials are used in a variety of applications, such as electric generators, speakers, hard drives, MRI machines, etc. Discovery of new magnetic materials with desirable properties is essential for advancement in these applications. In this research article, we describe the development and validation of a machine-learning model to discover new manganese-based stable magnetic materials. The machine learning model is trained on the input data from the Materials Project database to predict the magnetization and formation energy of the materials. New hypothetical structures are made using the substitution method, and the properties are predicted using the machine learning model to select the materials with desired properties. Harnessing the power of machine learning allows us to intelligently narrow down the vast pool of potential candidates. By doing so, we deftly reduce the number of materials that warrant in-depth examination using density functional theory, rendering the task more manageable and efficient. The selected materials, seemingly promising with their magnetic potential, undergo a meticulous validation process using the Vienna Ab initio Simulation Package, grounded in density functional theory. Our results underscore the paramount significance of input data in the efficacy of the machine learning model. Particularly in the realm of magnetic materials, the proper initialization of atomic magnetic spins holds the key to converging upon the true magnetic state of each material.
Murburn concept in cellular function and bioenergetics, Part 2: Understanding integrations-translations from molecular to macroscopic levels
Authors: Manoj Kelath Murali , Jaeken Laurent , Bazhin Nikolai Mikhailovich , Tamagawa Hirohisa , Gideon Daniel Andrew , Kavdia Mahendra
Published: December 2023

Thermogenesis, electro-chemical physiology (ECP), and electro-mechanical activities (EMAs) are fundamental facets of cellular functioning that are associated with powering, coherence, homeostasis, sensing, and response to stimuli. The classical Hodgkin–Huxley–Katz purview of ECP is derived from Nernst-based foundations for dilute solutions, whereas cellular milieus are mostly highly packed colloidal coacervates, with various types/levels of macromolecules (ions), interactions, and ordering of water. It has also been established that trans-membrane potential (TMP) manifestation can also be affected by adsorption of ions and effective charge separation (1e processes), necessitating the questioning and expansion of classical purviews. Further, we have demonstrated that the traditional explanation of electrogenic/stoichiometric and vitally deterministic bidirectional pumping/channeling of ions by membrane proteins (such as Na,K-ATPase) as the rationale for resting/dynamic TMP variations is untenable. In stark contrast, the murburn purview of ECP-EMAs acknowledges the complexity and discretization of the organization of water, ions, and macromolecules within the cell and does not solicit selective ion-pumping or TMP-based powering/propagation rationales. Herein, we summarize the murburn rationale for the molecular to macroscopic integration of processes such as thermogenesis, kinetic Na–K differentiation at the cell membrane, visual signal transduction and neuronal impulse relay, Complex V mediated mechano-chemostat function, flagella-based motility, etc., and discuss the alteration of cellular volume/tenor in muscle cell contraction. We assert that the membrane-embedded proteins/enzymes cannot use ATP to work against the natural laws of physics. Therefore, the classical perception of membrane-based ion pumps must be jettisoned to make way for the thermodynamics-friendly murburn purview.
Self-organizing behaviors of cardiovascular cells on synthetic nanofiber scaffolds
Authors: Peters Michael M. , Brister Jackson K. , Tang Edward M. , Zhang Felita W. , Lucian Veronica M. , Trackey Paul D. , Bone Zachary , Zimmerman John F. , Jin Qianru , Burpo F. John , Parker Kevin Kit
Published: December 2023

In tissues and organs, the extracellular matrix (ECM) helps maintain inter- and intracellular architectures that sustain the structure–function relationships defining physiological homeostasis. Combining fiber scaffolds and cells to form engineered tissues is a means of replicating these relationships. Engineered tissues' fiber scaffolds are designed to mimic the topology and chemical composition of the ECM network. Here, we asked how cells found in the heart compare in their propensity to align their cytoskeleton and self-organize in response to topological cues in fibrous scaffolds. We studied cardiomyocytes, valvular interstitial cells, and vascular endothelial cells as they adapted their inter- and intracellular architectures to the extracellular space. We used focused rotary jet spinning to manufacture aligned fibrous scaffolds to mimic the length scale and three-dimensional (3D) nature of the native ECM in the muscular, valvular, and vascular tissues of the heart. The representative cardiovascular cell types were seeded onto fiber scaffolds and infiltrated the fibrous network. We measured different cell types' propensity for cytoskeletal alignment in response to fiber scaffolds with differing levels of anisotropy. The results indicated that valvular interstitial cells on moderately anisotropic substrates have a higher propensity for cytoskeletal alignment than cardiomyocytes and vascular endothelial cells. However, all cell types displayed similar levels of alignment on more extreme (isotropic and highly anisotropic) fiber scaffold organizations. These data suggest that in the hierarchy of signals that dictate the spatiotemporal organization of a tissue, geometric cues within the ECM and cellular networks may homogenize behaviors across cell populations and demographics.
A present scenario of the computational approaches for ternary organic solar cells
Authors: Eraso Oscar , Bolaños Daniela , Echeverri Nikolas , Orozco Donneys Carolina , Ameri Tayebeh , Perea Jose Dario
Published: December 2023

Computer science implements algorithms and techniques to automate problem-solving solutions. Due to the chemical versatility of organic building blocks, many organic semiconductors have been utilized for organic solar cells (OSCs). The computational methods can potentially drive experimentalists to discover and design high-performance materials. OSCs' objective is the performance of their energy conversion efficiency and stability. One idea that has improved efficiency and stability is that of ternary systems, known as ternary organic solar cells (TOSCs). The photoactive layer in TOSCs is formed by mixing three distinct components together. This review is about the employment of computational approaches for investigating TOSCs. Here, we outlined the basics of computational methods and standard application procedures. This article offers a concise overview of various computational algorithms, relevant software, and tools. Additionally, it examines the present state of research regarding computations in TOSCs. The challenges associated with TOSCs, including intricacy metrics, diverse chemical structures, and programming skills, are discussed. Furthermore, we suggest some ways to improve the utility of computation in TOSCs research enterprises.
Modeling and ignition performance study of Al/Ni multilayer energy-containing microdevices
Authors: Yan Shaoan , Zang Junyi , Zhu Yingfang , Tang Tao , Chen Xin , Li Xingyu , Chen Yinyu , Zheng Xuejun , Tang Minghua
Published: December 2023

In this paper, we designed double V-shaped Al/Ni multilayer energy-containing microdevices with different V-angles, and we performed finite element modeling and simulation of the heat transfer process of the designed energy-containing microdevice. Temperature-dependent resistivity was introduced to effectively simulate the phase change during ignition. We simulated the temperature and current density distribution in the central region of the Al/Ni multilayer energy-containing microdevice and predicted the ignition voltage threshold for the specific device structure. Al/Ni multilayer energy-containing microdevices with different V-angles were prepared by electron beam evaporation technology, and ignition experiments on the prepared devices under the excitation of 47 μF capacitance were conducted. The experimental results show that the critical voltage of ignition increases with the increase in the V-angle, which verifies the correctness of the proposed finite element model.
Variable laser profiles and polarization states in the wave-mixing scheme for the generation of THz radiation in collisional-magnetized clustered-plasma
Authors: Choobini Ali A. Molavi , Aghamir Farzin M.
Published: December 2023

The four-wave mixing (FWM) mechanism for the generation of Terahertz (THz) radiation in magnetized-collisional clustered-plasma is studied. Clusters can trap the incident laser fields, leading to efficient energy transfer to plasma electrons and the creation of a strong nonlinear current. The size and density of clusters can be tuned to control the emission of THz radiation. The smaller clusters can bring about higher intensity THz radiation, while larger clusters can contribute to the broader THz frequency range. The THz radiation angular distribution patterns in the forward direction have been assessed, and the impact of plasma interaction length, cluster radius, and plasma electrons collision frequency on the generated THz wave patterns has been investigated. The FWM analysis highlights the importance of plasma clusters as well as magnetic fields in the efficient generation of THz emission. The model also takes into consideration how an induced electron current density initiated by DC external magnetic field can boost radiation power without changing the directivity diagram.
Nonlinear optical properties of gold with intense femtosecond laser excitations above the damage threshold
Authors: Wang Zibo , Kan Zhe , Shen Mengyan
Published: December 2023

The nonlinear optical properties of gold thin films have been studied under the irradiation of destructive laser pluses. The transmissivity and the reflectivity of a 100-nm-thick gold film are measured with femtosecond laser irradiations up to 106 J/m2 fluence, which is much higher than the damage threshold of gold. The nonlinearity is calculated with Fresnel loss equations. The real part of the complex refractive index is calculated to have a peak at ∼10 kJ/m2, which is close to the damage threshold. The complex third-order nonlinear susceptibility χ3 is estimated to be (4.95 − 2.02i) × 10−21 m2/V2, which agrees with the trend in previous reports that it decreases as the pulse duration decreases. This nonlinearity is further studied with a plasmon-photon exchange (PPE) model, where laser induced plasmons and absorbed photons are strongly correlated. The result of the simulation with the PPE model is in good agreement with the experimental transmissivity above the damage threshold. The model predicted an interaction time between photons and plasmons to be about 500 fs. This model is found to be essential in understanding such nonlinear optical processes under both extremely high and conventionally low laser irradiations.
The convexity condition of density-functional theory
Authors: Burgess Andrew C. , Linscott Edward , O’Regan David D.
Published: December 2023

It has long been postulated that within density-functional theory (DFT), the total energy of a finite electronic system is convex with respect to electron count so that 2Ev[N0] ≤ Ev[N0 − 1] + Ev[N0 + 1]. Using the infinite-separation-limit technique, this Communication proves the convexity condition for any formulation of DFT that is (1) exact for all v-representable densities, (2) size-consistent, and (3) translationally invariant. An analogous result is also proven for one-body reduced density matrix functional theory. While there are known DFT formulations in which the ground state is not always accessible, indicating that convexity does not hold in such cases, this proof, nonetheless, confirms a stringent constraint on the exact exchange–correlation functional. We also provide sufficient conditions for convexity in approximate DFT, which could aid in the development of density-functional approximations. This result lifts a standing assumption in the proof of the piecewise linearity condition with respect to electron count, which has proven central to understanding the Kohn–Sham bandgap and the exchange–correlation derivative discontinuity of DFT.