bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of Delay and Queue on the Length of Left-Turn Storage at Palestine Intersections in Baghdad city, Iraq
Authors: Hussein Ameer A. , Jehad Ali E. , Hammad Majid H.
Published: September 2023

At intersections, Left-turning vehicles seek to occupy the same physical space as close to the stop line as possible. These result in high conflicts, delays, and blockage of vehicles by turning vehicles and vice versa. The impact of the lengths of Left-turn lanes on intersection delays is considered to optimize the lengths of the Left-turn lanes. Data for traffic counts, queue lengths, and signal timing are collected from three intersections in Baghdad city in Iraq. The methodology involves the development of estimation models using traffic Simulation SIDRA INTERSECTION 8.0 and simulating various scenarios by varying traffic signal conditions to evaluate delays and queues caused by varying lengths of the Left-turn Lane. Optimal lengths are computed and compared to existing lengths in intersections. No differences in delay, queue, and lengths of the Left turn lane are found using t-test analysis for significance. Outputs from the three models were compared to the maximum observed in the field from the selected intersections. Data analysis involved determining the R2 and the standard error mean between the model output and the observed data. In general, SIDRA INTERSECTION 8.0 overestimated queue vehicles and length of storage for approaches with a high degree of saturation ratios and underestimated it for those with a high degree of saturation ratios.
The Impact of Crumb-Rubber on the Mechanical Characteristics of Modified Asphalt Mixture
Authors: Khalaf Sarah F. , Yousif Rana A. , Tayh Sady A. , Jasim Abbas F.
Published: September 2023

By following up on the effect of rubber, which has recently been widely used as a direct additive to the asphalt binder or to the concrete mix as a percentage of the weight of the aggregate. The success of the effect of this type of admixture on improving the modified asphalt binder in addition to the modified concrete mix has been investigated. As it was noted the importance of following the asphalt properties due to the increasing use of crumb rubber modifiers in asphalt mixtures, there is a more position to check their rheological and physical properties comprehensively. In general, the performance of the asphalt rubber binder is affected by the rubber crumb content and mixing conditions. This research used 40/50 asphalt grade and Crumb Rubber additives with contents (5, 10, 15, and 20%). The main objectives of this study were to investigate the physical and rheological properties of rubber-modified asphalt binder and mixture. These purposes were achieved by testing HMA samples using the Marshall test approach to determine (Marshall stability and flow and void properties) and measuring the retained Marshall stability and DSR and Viscosity test. Sample testing showed that when recycled rubber was used as modifiers for asphalt mixes, the mixture became more stable, had a higher bulk specific gravity, and had less flow value and air voids. This infers that using recycled rubber can enhance the rutting resistance of bituminous mix.
Effects of Filler Types and High RAP Content on the Ability of HMA to Withstand Moisture Damage
Authors: Rasheed Sozan S. , Nsaif Maha H. , Shubber Ammar A. M.
Published: September 2023

Using hot mix asphalt (HMA) and recycled asphalt pavement (RAP) simultaneously has many technological benefits. At all service temperatures, moisture damage is a hazard with these mixes. Thus, moisture's effects on mixtures' effectiveness were studied using experimental techniques, such as the tensile strength ratio (TSR). Four different ratios of RAP for the surface layer (20, 30, 40, and 50%)) were added to the asphalt mixture (HMA) to study as well as find the content Optimal RAP for both layers RAP through Marshall stability and hygroscopic resistance of asphalt mixtures through moisture damage is examined. The ratio (TSR) of the optimal RAP content mixture is compared with the asphalt mixture without RAP for three fillers and for both layers. The findings revealed a slight reduction in tensile strength of the (HMA) that does not contain RAP in contrast to the asphalt control mix containing the reclaimed pavement, where it was found that the percentages were slightly more and still higher than 80%. The results indicate that, in general, "Hot asphalt mixtures" containing RAP can be recommended for areas that experience moisture damage without worrying about environmental and natural resource restrictions.
Hydraulic Model Prediction of the Total Load of Sediment Transport in The Euphrates River at The Upstream Ramadi Barrage
Authors: Hammad Abdulhaleem A. , Sulaiman Sadeq O.
Published: September 2023

Examining river engineering properties and bed erosion is one of the most challenging but crucial issues in river engineering and sediment hydraulics, so preventing erosion and sedimentation is one of the primary goals of river management and prediction of river behavior. This research aims to give hydraulic engineers and decision-makers an accurate and dependable sediment transport equation that could be utilized to govern river engineering and modify river morphology. This study evaluated the carried sediments and their estimated quantity upstream of the Ramadi Barrage on the Euphrates River in the Anbar area of western Iraq. Six formulas, including Yang, Shen, Hung, Ackers and White, Engelund and Hansen, and Bagnold's and Toffaleti's, were used to evaluate the applicability of sediment transport in the study area. The performance of these models was assessed based on the precision of the actual sediment load relative to a specified deviation ratio. The analyses indicated that the Engelund-Hansen formula is the most applicable for this section of the river; that concludes, field data indicated an annual total sediment flow of roughly 1, 536, 337 tons.
Comparing the Design Alternatives Using Building Information Model (BIM) and Constructability in Iraqi Construction Projects
Authors: Ahmed Ola A. , Mahjoob Ahmed M. R.
Published: September 2023

The Iraqi construction industry suffers from many issues that lead to many design errors, clashes, delays and cost overruns. Therefore, applying constructability will prevent these issues from happening, as it has proven its positive effect in different projects around the world. The goal of this paper is to use building information modelling (BIM) to assess the constructability, provide the opportunities for the project stakeholders to choose the best constructable design alternative and find the affection of applying constructability on project cost. The practical side of this research consists of two parts: in the first part, 37 factors are collected from the literature review as factors that effect on constructability. After that, a survey occurs in two sessions an open and closed questionnaire. The results were analyzed, and their mean, standard deviation, Cronbach's Alpha and developed weight will be found. The second part clears the method of linking these factors with BIM in order to assess the constructability in two different designs’ projects and find their cost. The method applies through a case study of an educational building located in Baghdad, Iraq; Rivet and Microsoft Excel programs are used in this paper. the result approves the success of using BIM technology to assess the constructability of a project in Iraq. Also, it shows how project cost will be affected when applying constructability factors.
Assessments and Historical Changes the Water Quality of Sawa Lake, Southern Iraq for the Period 1977-2020
Authors: Al-Musawi Nawar O. , Al-Sulaiman Ahmed M.
Published: September 2023

This investigation pertains to the evaluation of water quality in SAWA Lake, located in the Al-Muthanna province of Southern Iraq, from 1977 to 2020. Understanding the water quality and assessments of this Lake is of great importance. The Lake is home to small, transparent, blind fish measuring approximately 10 cm and is often referred to as the "wonderful" or "strange" Lake due to its many unique features. The study focuses on several elements to represent water quality, including total dissolved solids (TDS), electrical conductivity (EC), pH, and temperature (T), which were measured directly in the field. Additionally, scientific concepts such as K+, Ca2+, Cl-, HCO3, and KSO4 were used in each sample. Scientists have analyzed the density and salinity of the lake water and found that its water density exceeds that of seawater, and its salinity exceeds that of the Gulf of Arabia by about 1.5 times. The water is salty, surrounded by natural lime, and is automatically renewed by nature when it is broken. Its hardness also characterizes it, and its water volume fluctuates depending on the wet and dry seasons. The Lake is roughly 4.74 km in length, and all the elements under study showed an increase in concentration during the periods of 1977, 1983, and 2003 with NaSO4, which later changed to MgCl between 2007 and 2011. The study found that Sawa Lake water was unsuitable for drinking or irrigation purposes between 2016 and 2020 due to the increased concentration of certain elements. This increase in concentration is attributed to the Lake's location, nutrition, and the lack of rain, which means it relies solely on groundwater.
Synthesis of Oxindoles via SmI2-Promoted Reduction of 2-Nitrophenylacetic Acids
Authors: Zhang Songlin , Wang Pengkai
Published: September 2023

The reduction of 2-nitrophenylacetic acids to oxindoles promoted by SmI2 is reported for the first time. This reaction involving the reduction of nitro group proceeds through N–O bond cleavage and direct condensation with the neighboring carboxyl group. From a synthetic point of view, a new method for the synthesis of oxindoles in mild neutral conditions is developed.
Iterative Assembly of Chiral Alcohols Utilizing CMMP-Mediated Mitsunobu Reactions
Authors: Kitamura Kei , Kaku Hiroto , Ise Saki , Tsunoda Tetsuto
Published: September 2023

An iterative assembly of chiral alcohol building blocks is reported utilizing cyanomethylene trimethylphosphorane (CMMP)-mediated Mitsunobu reactions. 1,3-Benzodithiole tetraoxide (BDT) was used as the platform to prepare long-chain saturated compounds with multiple stereocenters en route to polyisoprenoid natural products. Selectively protected chiral 1,3-butanediols played a key role in iterative chain elongation for the construction of 1,5-dimethyl branched arrays with high stereocontrol.
Surveillance after Total Neoadjuvant Therapy: What to do for Near-Complete Responders
Authors: Friedman Garrett
Published: September 2023

A proportion of patients who undergo total neoadjuvant therapy for rectal cancer will achieve what is classified as a near-complete response. Significant debate exists as to the optimal management strategy for these patients with large heterogeneity in management. This article will examine the therapeutic and surveillance options for these patients as well as the relevant outcomes data.
A Rare Case Report of Simultaneous Occurrence of Chronic Subdural Hematoma and Acute Extradural Hematoma in a Patient after Multiple Ventriculoperitoneal Shunt Surgeries
Authors: Yadav Vikrant , Prasad Ravi Shankar
Published: September 2023

Ventriculoperitoneal (VP) shunt surgeries are common neurosurgical procedure for hydrocephalus. Subdural hematoma (SDH) and extradural hematoma (EDH) are rare but potentially life-threatening complications following VP shunt surgeries. We are describing probably the first case in which a 12-year-old boy presented to the emergency room in altered sensorium and gradual onset quadriparesis following multiple shunt revision procedures done in an outside hospital. Computed tomography head showed chronic right-sided frontotemporoparietal chronic SDH and parietal dominant EDH simultaneously with multiple shunt systems in ventricles. Patient was taken for surgery in emergency and emergent evacuation of hematoma was done. Patient improved in the postoperative period. In this case report we will make an attempt to describe a rare complication of VP shunt surgery and possible mechanisms responsible for it.
Role of ancillary investigations in medicolegal autopsy to establish the cause of death and legal implications
Authors: Arora Arneet , Moirangthem Sangita , Yadav Jayanthi , Alikka Suhail , Gour Aniket , Kaore Navinchandra M.
Published: September 2023

Sudden death in young females can have various causes and it is important to investigate the cause thoroughly. In cases with a vague history, postmortem ancillary investigation can also help to establish or rule out potential causes of death, such as underlying medical conditions or environmental factors. These investigations may include various laboratory tests, such as toxicology, histology, microbiology, and genetic analysis, as well as radiological imaging studies. This information not only helps in ascertaining the cause and manner of death but also helps in establishing the legal connotations in any medicolegal case. This is a case of a young woman allegedly 18 years brought for a medicolegal autopsy. She had been feeling unwell for a few days before her death, experiencing vomiting, weakness, and fatigue. Although no underlying disease was diagnosed, she was advised to take a pregnancy test. Fifteen days later, she died at home continuing to feel unwell. Upon autopsy, the young woman was found to be emaciated, and revealed a male fetus, of 4 to 5 months of gestational age, in her uterus. A radiological examination of bones conducted postmortem revealed that the age of woman was approximately 15 years old. Postmortem microbiology analysis revealed the presence of the bacteria Leuconostoc mesenteroides in a blood sample collected from the subclavian vein. The pathogenicity of this bacteria in the cause of death along with the role of ancillary investigation in the light of Indian criminal law and its challenges are being discussed.
Generalized synchronization mediated by a flat coupling between structurally nonequivalent chaotic systems
Authors: Letellier Christophe , Sendiña-Nadal Irene , Leyva I. , Barbot Jean-Pierre
Published: September 2023

Synchronization of chaotic systems is usually investigated for structurally equivalent systems typically coupled through linear diffusive functions. Here, we focus on a particular type of coupling borrowed from a nonlinear control theory and based on the optimal placement of a sensor—a device measuring the chosen variable—and an actuator—a device applying the actuating (control) signal to a variable’s derivative—in the response system, leading to the so-called flat control law. We aim to investigate the dynamics produced by a response system that is flat coupled to a drive system and to determine the degree of generalized synchronization between them using statistical and topological arguments. The general use of a flat control law for getting generalized synchronization is discussed.
Dynamic characteristics of unsteady cavity evolution of high-speed projectiles passing through holes in free surface ice flows
Authors: Cui Wenzhi , Zhang Song , Zhang Qi , Sun Tiezhi
Published: September 2023

The free surface condition of water-entry problems will be significantly modified by the presence of an ice sheet on the water surface. In this paper, we employ computational fluid dynamics to simulate the process of a cylinder entering a water body vertically and validate the numerical method by comparing the cavity evolution with experimental data. Four high-speed water-entry cases are considered: an ice-free water surface, an ice sheet with circular holes, and an ice sheet with minor and normal sized petal-shaped holes. The cavity evolution, flow field characteristics, and motion parameters of the projectile after entering the water are analyzed separately, and the effects of the ice sheets with holes on the typical water-entry characteristics are identified. The results show that the cavity closure mechanism shifts from surface to shallow closure, and a funnel-shaped cavity is observed below the surface when ice is present. The size of the cavity is extremely restricted, but the collapse of the cavity is delayed. The pressure and flow characteristics around the projectile are also affected by ice on the water surface, and the stability of the trajectory is enhanced by the existence of the ice sheet. Finally, the positive acceleration of the projectile triggered by high pressure at the tail of the structure is found to be much larger than that in the ice-free case.
Experimental investigation on multi-mode resonances in a rectangular harbor
Authors: Luo Meng , Wang Gang , Sun Zhongbin , Qin Shufang , Zheng Jinhai
Published: September 2023

Physical experiments were conducted to investigate the oscillations in a rectangular harbor for different modes with the same resonant frequency. Two multimode resonances, that is, case A for modes (0, 2) and (3, 1) and case B for modes (1, 1) and (2, 0) excited by bichromatic waves, were examined. The results showed that the multimode resonance was excited. During the response process when the resonance is initially excited, the subharmonic energy mainly focused on mode (0, 2) for case A and mode (2, 0) for case B. With the continuous input of wave energy, periodic modulations for the infragravity waves in the harbor were observed, implying that the subharmonic energy transfers freely between the two modes in a quasi-steady state. During the damping process, with no waves, the subharmonic energy returns to the mode that occupies the response process. The phenomenon that the subharmonic energy concentrates in the same mode in the response and damping processes is possibly because these modes are more easily excited than the others.
A cryogenically cooled 200 kV DC photoemission electron gun for ultralow emittance photocathodes
Authors: Gevorkyan Gevork , Sarabia-Cardenas Carlos , Kachwala Alimohammad , Knill Christopher , Hanks Tatum J. , Bhattacharyya Priyadarshini , Li William H. , Cultrera Luca , Galdi Alice , Bazarov Ivan , Maxson Jared , Karkare Siddharth
Published: September 2023

Novel photocathode materials like ordered surfaces of single crystal metals, epitaxially grown high quantum efficiency thin films, and topologically non-trivial materials with dirac cones show great promise for generating brighter electron beams for various accelerator and ultrafast electron scattering applications. Despite several materials being identified as brighter photocathodes, none of them have been tested in electron guns to extract electron beams due to technical and logistical challenges. In this paper, we present the design and commissioning of a cryocooled 200 kV DC electron gun that is capable of testing a wide variety of novel photocathode materials over a broad range of temperatures from 298 to 35 K for bright electron beam generation. This gun is designed to enable easy transfer of the photocathode to various standard ultra-high-vacuum surface diagnostics and preparation techniques, allowing a full characterization of the dependence of beam brightness on the photocathode material and surface properties. We demonstrate the development of such a high-voltage, high-gradient gun using materials and equipment that are easily available in any standard university lab, making the development of such 200 kV electron guns more accessible.
Hydrodynamic and thermal model for gravity-driven smooth laminar film flow undergoing flash evaporation cooling: Case study and correlation development
Authors: Sharma Manvendra , Dandotiya Deepak , Hiremath Kirankumar R. , Plappally Anand Krishnan , Chakraborty Prodyut R.
Published: September 2023

Hydrodynamic and thermal analyses have been carried out for gravity-driven smooth laminar film flow, undergoing flash evaporation at the free surface. A classical one-dimensional semi-analytical approach has been adopted to address a unique problem where hydrodynamic and thermal boundary layers (TBLs) approach from opposite directions and eventually intersect each other. This occurs due to the rapid evaporation cooling at the film-free surface exposed to the low-pressure ambiance, leading to the growth of a TBL from the free surface. In contrast, the hydrodynamic boundary layer (HBL) grows from the solid wall over which the film flow occurs. The intersections between the TBL and HBL edges, HBL edge and the free surface, and TBL edge and the wall, in conjunction with the attainment of a fully developed hydrodynamic condition, result in the division of the overall film domain into three distinct hydrodynamic and five distinct thermal sub-zones requiring zone-specific formulations. The model is successfully validated for hydrodynamic formulations with the existing experimental data. However, the lack of available experimental studies limits the validation of the proposed thermal model. Correlations for relevant thermal and hydrodynamic parameters, such as local Nusselt number, local free surface temperature, local bulk mean temperature, and local film thickness, are developed based on the model predictions. The proposed model and the correlations derived from its predictions are anticipated to serve as crucial benchmarks for optimizing the design of thermal management and desalination systems that are fundamentally driven by the film evaporation process.
Particle-in-cell simulations of the ionization process in microwave argon microplasmas
Authors: Wang Haoxuan , Venkattraman Ayyaswamy , Loveless Amanda M. , Garner Allen L.
Published: September 2023

The importance of microwave device reliability and performance for microscale devices motivates a more fundamental understanding of breakdown mechanisms in this regime. Microwave breakdown theories predict breakdown when electron production balances electron loss. Electron production depends strongly on the ionization rate νi; however, previous studies either used the measured νi in macroscale gaps or the empirical formula for DC voltage, inaccurately predicting νi in microscale gaps. Alternatively, this work characterizes νi in microwave microplasmas by using particle-in-cell simulations. We calculated νi in argon gas at atmospheric pressure for 2–10 μm gaps under AC fields ranging from 1 to 1000 GHz. The behavior of νi may be separated into two regimes by defining a critical frequency fcr that depends on the amplitude of the applied voltage, gap distance, and pressure. For frequency ffcr, the phase-space plots indicate that the electrons are confined inside the gap, causing the electron number to grow exponentially and vi/p to become a function of Eeff/p. These results elucidate the ionization mechanism for AC fields at microscale gap distances and may be incorporated into field emission-driven microwave breakdown theories to improve their predictive capability.
Experimental and numerical comparisons of geometric scaling criteria for lean premixed swirl combustor
Authors: Xie Wenda , Shi Ting , Ge Bing , Zang Shusheng
Published: September 2023

This study experimentally and numerically investigates the applicability of the DaI and Re criteria for scaling the geometry of a lean premixed swirl combustor during a reaction and in the absence of it. We first set up an experimental system to test the loss of pressure, the flow field, and NOx emissions in a prototype combustor and two models of it scaled to 3/5 of its size. The results showed that the friction in the flow in the prototype decreased with an increase in its intensity, and the corresponding constant DaI model (M-D) exhibited a similar trend, while the constant Re model (M-R) exhibited an adverse trend to that of the prototype. The results of particle image velocimetry (PIV) of the flow field in the non-reactive state showed that regardless of the criterion used and the state of the reaction, the flow fields of the prototype and the models were similar under flows of different strengths. However, a quantitative comparison of their distributions of velocity showed that the peak velocity of the rotating jet of M-R was significantly lower than that of the prototype. PIV results of the flow field in the reactive state exhibited similar phenomena. Moreover, the NOx emissions of M-D were consistent with those of the prototype, while emissions from M-R were significantly higher. The numerical results also showed that the shape of the flame and the pattern of flow of M-R were significantly different from those of the prototype.
Analysis on flow-induced vibration of square cylinders with different vibration forms and the flow energy harvesting capacity
Authors: Yu Mengyao , Wang Xiaoyan , Cai Jiancheng , Brazhenko Volodymyr , Tan Jianbo , Xu Zisheng , E Shiju
Published: September 2023

This study numerically investigates the flow-induced vibration (FIV) of a single-degree-of-freedom transverse vibration and pivoted rotation of a square cylinder with the Reynolds number (Re) range of 0.7 × 104 to 6 × 104. Different FIV phenomena with Re increasing are reported. In the vortex-induced vibration (VIV) branch, the amplitude and energy harvest efficiency of the transverse vibration are higher than those of the pivoted rotation, and the situation is opposite in the VIV-galloping transition and galloping branches. Checking the wake vortex indicated that the change in the angle of attack caused by the pivoted rotation of the square cylinder was the cause of these phenomena. The most significant feature was that, at the maximum amplitude, a pair of co-rotating vortices (C mode) shed. The transverse vibration had larger vibration amplitudes and lower aerodynamic force and energy harvest efficiency compared with the pivoted rotation in galloping, and the energy harvest efficiency no longer increased with higher Re. The energy harvest efficiency of the pivoted rotation had two outstanding peaks at maximum pivot angles of θmax = 29° and 41.2°, followed by a decreasing trend. For the transverse vibration, the force induced by the vortices cancels each other out so that the energy harvest efficiency almost does not change. For the pivoted rotation, the amplitude, which does not increase, makes it easier for the wake vortex to interact and interfere with the energy harvest procedure.
MoO3 facilitator enables ultrathin and stabilized Li metal anode for quasi-solid-state batteries
Authors: Zhai Yanfang , Chen Zongyuan , Liu Chengyong , Ouyang Chuying , Liang Xiao , Paoprasert Peerasak , Hu Ning , Song Shufeng
Published: September 2023

Lithium metal is considered as a highly desirable anode for high-energy and safe quasi-solid-state batteries. Nevertheless, the terrible wettability of molten lithium does not permit it to spread out on the lithiophobic current collectors, limiting their practical applications. Herein, we report an ultrathin lithium–molybdenum (Li–Mo) composite anode to settle this hurdle by reacting molten Li with α-MoO3 nanobelts. The experimental characterizations and density functional theory calculations reveal that the interfacial binding energy between molten Li and copper (Cu) foil can be decreased by adding α-MoO3, which improves the wettability toward Cu current collector and helps to realize uniform spreading of an ultrathin Li with a thickness of ∼35 μm. As a demonstration, the ultrathin Li–Mo is stabilized to provide a high average Coulombic efficiency of ∼95.2% over 300 cycles at a high current density of 1 mA cm−2, and a capacity retention of 100% is realized for a quasi-solid-state battery paired with LiFePO4 and poly(1,3-dioxolane) electrolyte. These findings open up a promising option for enhancing the wettability of molten lithium and provide a sustainable strategy for the large-scale production of ultrathin lithium for realizing next-generation high-energy and safe quasi-solid-state batteries.
In unison magnetization reversal in a magnetoelastic bilayer structure
Authors: Cotón N. , Andrés J. P. , Cabrera A. , Maicas M. , Ranchal R.
Published: September 2023

Due to the magnetostriction effect, a magnetic material changes its dimensions when it is magnetized. In this work, we show how in a magnetostrictive bilayer structure comprising two materials with magnetostriction constants of opposite signs, the magnetic switching is affected by magnetoelastic coupling. While the layer with positive magnetostriction tries to elongate in the direction of the applied magnetic field, the layer with negative magnetostriction tries to contract. In the studied bilayers, the mechanical influence of each magnetostrictive layer on the other is of the opposite sign because of their opposite magnetostrictive constants. Since magnetoelasticity is not an interfacial interaction but an intrinsic property of magnetic materials, the mechanical strain promoted by the applied magnetic field affects the layers as a whole. The net effect is a simultaneous reversal of magnetization of the two layers regardless of their thicknesses. This behavior has been studied in bilayers with different thickness ratios comprising Ni90Fe10, negative magnetostriction and Fe70Ga30, positive magnetostriction. These results demonstrate the possibility of using this physical mechanism to beat the critical limit thickness imposed by interfacial interactions in magnetically coupled multilayers in such a way that the magnetization reversal is made in unison regardless of the layer thickness.
Ab initio calculations of low-energy quasiparticle lifetimes in bilayer graphene
Authors: Spataru Catalin D. , Léonard François
Published: September 2023

Motivated by recent experimental results, we calculate from first principles the lifetime of low-energy quasiparticles in bilayer graphene (BLG). We take into account the scattering rate arising from electron–electron interactions within the GW approximation for the electron self-energy and consider several p-type doping levels ranging from 0 to ρ≈2.4×1012 holes/cm2. In the undoped case, we find that the average inverse lifetime scales linearly with energy away from the charge neutrality point, with values in good agreement with experiments. The decay rate is approximately three times larger than in monolayer graphene, a consequence of the enhanced screening in BLG. In the doped case, the dependence of the inverse lifetime on quasiparticle energy acquires a non-linear component due to the opening of an additional decay channel mediated by acoustic plasmons.
Influence of overdriven detonation on the energy release of aluminized explosives in underwater explosion
Authors: Shan Feng , Jiao Jun-jie , Wang Han-cheng , Wang Jia-xing , Qi Yanjie , Gao Zhan-bo , Chen Peng , Fang Zhong , Pan Xu-chao , He Yong
Published: September 2023

An underwater explosion experiment was designed for the cyclotrimethylenetrinitramine-based aluminized explosives to study the influence of detonation conditions on the explosion performance and the afterburn reaction of aluminum (Al) particles. The research results showed that the performance of shock wave and bubble pulsation grew stronger under the influence of overdriven detonation (ODD), and the contribution of ODD to the bubble energy was associated with the proportion of the inner core and the outer coat. Considering the propagation characteristics of the detonation wave in the ordinary charge and the inner/outer charge, the attenuation of ODD and its role in the initial pressure of the bubble were investigated, and this relationship was used to establish a numerical model for the bubble dynamic behaviors of aluminized explosives. According to the experimental results, the correctness of the established model for the bubble dynamics under ODD was verified, and the variation laws of the afterburn reaction during the bubble pulsation were investigated. It was found that the initial pressure of the bubble under ODD was higher than that under steady detonation. The improvement on the initial pressure promoted the afterburn reaction during the accelerating expansion and enhanced the bubble expansion capacity to support the formation and propagation of shock waves. In the subsequent bubble pulsation, the duration of the decelerating expansion was significantly longer than that of the accelerating expansion, and the ODD had little effect on the afterburn reaction in this stage.
Lagrangian steady-state discrete Boltzmann model for non-equilibrium flows at micro–nanoscale
Authors: Zhang Yudong , Wu Xiao , Nie Bangbang , Xu Aiguo , Chen Feng , Wei Ronghan
Published: September 2023

In micro- and nanoscale channels, where the characteristic scale approaches or falls below the mean free path between gas molecules, flow characteristics exhibit pronounced discontinuity. In such scenarios, continuum-based models are inadequate, and adopting kinetic models based on statistical mechanics becomes imperative for accurately describing the gas transport phenomenon. This paper presents a novel steady-state discrete Boltzmann model (DBM) that is specifically tailored for non-equilibrium flows at the micro–nanoscale. Unlike the conventional DBM, the new model focuses on the evolution equation of the non-equilibrium component of the molecular velocity distribution function in the Lagrangian coordinate system, which follows the fluid micro-element. Through numerous numerical simulations, we demonstrate the effectiveness of our model in capturing gas flow characteristics across a wide spectrum of rarefaction parameters, ranging from slip flow to free molecular flow. Utilizing this new model, we initially examine the Onsager reciprocal relationship between heat flux generated by pressure gradients and mass flux resulting from temperature gradients in micro/nanochannels. Subsequently, we calculate higher-order non-equilibrium quantities up to the 10th order and make a comparison of their characteristics. Finally, we present and discuss the features of the non-equilibrium component of the molecular velocity distribution function.
Energy mechanism for the instability of liquid jets with thermocapillarity
Authors: Sun Yu-Wen , Hu Kai-Xin , Chen Qi-Sheng
Published: September 2023

Xu and Davis [J. Fluid Mech. 161, 1–25 (1985)] examined the stability of long axisymmetric liquid jet subjected to an axial temperature gradient, finding capillary, surface-wave, and hydrodynamic modes. They showed that capillary breakup can be retarded or even suppressed for a small Prandtl number (Pr < 1) and a large Biot number (Bi ≥ 1). In the present work, the energy mechanism is carried out for these three kinds of flow instabilities, and the mechanism of suppressing capillary breakup is clarified. When the Reynolds number (RB) is not large, the work done by the pressure on the free surface (PS) is the main energy source of the capillary instability. At small Pr and large Bi, the phase difference between the radial velocity and surface deformation increases with RB, leading to the decrease in PS, which prevents the occurrence of capillary breakup. Meanwhile, the work done by thermocapillary force becomes the main energy source, making hydrodynamic modes unstable. The perturbation flow fields are displayed, which shows that the temperature fluctuations of three modes differ from each other.
Rheology mediates transition of vortex evolution patterns in microcavity flow of polymer solutions
Authors: Zheng Zhou-Yi , Xu Xiao-Yu , Wang Dong , Qin Kai-Rong , Xue Chun-Dong
Published: September 2023

Vortex instability in cavity flow is a fundamental component of microfluidic applications such as flow mixing, nanoparticle synthesis, and cell/particle manipulation. In contrast to Newtonian fluids, non-Newtonian fluids exhibit significantly different flow behaviors due to their non-linear flow dynamics. This study experimentally investigates the flow dynamics of polymer solutions with distinct rheological properties through a microcavity and quantifies the influence of the rheological degree on the evolution dynamics of vortices. We find three typical vortex evolution patterns in the cavity flow of polymer solutions and show that the rheological degree mediates the transitions among these patterns. The vortex evolution in the cavity flow of all polymer solutions tested in this study shifts from a basic increasing logistic function to one of three typical patterns as the polymer concentration increases. It is clarified that the pattern transition is related to the elasticity number and shear-thinning index of the fluids, and the phase difference between identical patterns is due to differences in the viscosity and elasticity of the fluids. These results extend our understanding of the vortex dynamics of complex fluids in cavity flow and provide theoretical guidance for enhancing the working efficiency of cavity-structured microfluidic applications using polymer solutions. The results of this study may also inspire developments in the flow regulation of drug delivery in blood through the vascular system.
Molecular dynamics simulation of epoxy resin properties at different C=N contents
Authors: Zhang Lei , Chen Liangyuan , Huang Wei , Rao Xiajin , Lu Yufeng , Zhang Wei , Pan Shaoming , Yu Min
Published: September 2023

In response to the green development strategies of countries all over the world, research on degradable epoxy resins has attracted widespread attention. The introduction of reversible covalent bonds in the conventional cross-linked structure of epoxy resins is one of the methods to achieve degradation of epoxy resins, and most researchers use molecular dynamics simulations in their preliminary studies to investigate the feasibility of the introduction of reversible covalent bonding schemes. The purpose of this paper is to investigate the feasibility of introducing C=N into the cross-linked structure of epoxy resins. Four formulation schemes of vanillin-based monoepoxides with the curing agent 4,4′-methylenebis(cyclohexylamine) were designed, and the molecular dynamics simulation method was used to cross-link them. The changes in the cross-linking degree, structural parameters before and after cross-linking, free volume fraction, and C=N content before and after cross-linking were investigated. The effects of different C=N contents on the thermal properties such as glass transition temperature and thermal expansion coefficient, as well as the mechanical properties such as the elastic modulus and shear modulus of this epoxy resin, were investigated. The bond-breaking characteristics of C=N, C–N, and C–O were compared by density of states and differential charge density simulations. Then the degradation mechanism of epoxy resin after the introduction of C=N was illustrated. The results show that as the specific gravity of the curing agent molecule increases, the cross-linking degree tends to increase. The cross-linked model has reduced volume, increased density, decreased energy, and a more stable structure. After crosslinking, the gaps between the segments in the system become smaller, and the fraction of free volume decreases as the proportion of crosslinking agent molecules increases. The C=N content in epoxy resin shows an increasing trend first and then decreases with the increase in the proportion of the curing agent. The glass transition temperature of the material increases with the increase in C=N content, while the coefficient of thermal expansion decreases with the increase in C=N content. The elastic modulus and shear modulus of the material show an increasing trend with the increase in C=N content, with a relatively gradual change in magnitude. Compared with C–N and C–O bonds, the C=N bond is weaker in strength, has a greater polarity, and is more prone to cleavage and degradation.
Manipulating the propagation of ionization wave by pulsed electrical potential in atmospheric plasma jet
Authors: Lu Chenzi , Fang Junlin , Xu Shaofeng , Guo Ying , Shi Jianjun
Published: September 2023

A noninvasive method was developed to measure the electrical potential in an atmospheric pressure plasma jet. The spatiotemporal evolution of electrical potential was measured by a wire electrode in experiment and simulated by a two-dimensional self-consistent numerical model, which demonstrates that the electrical potential along with the traveling ionization wave outside the discharge tube in ambient air plays a significant role on the propagation of ionization wave. It furtherly shows that the enhancement and restriction of ionization wave propagation are dependent on the amplitude of electrical potential on the auxiliary electrode, which proposes the way to manipulate the propagation of ionization wave in atmospheric pulsed discharge plasma jet.
Sequencing 4.3 million mutations in wheat promoters to understand and modify gene expression
Authors: Zhang Junli , Xiong Hongchun , Burguener Germán F. , Vasquez-Gross Hans , Liu Qiujie , Debernardi Juan M. , Akhunova Alina , Garland-Campbell Kimberly , Kianian Shahryar F. , Brown-Guedira Gina , Pozniak Curtis , Faris Justin D. , Akhunov Eduard , Dubcovsky Jorge
Published: September 2023

Wheat is an important contributor to global food security, and further improvements are required to feed a growing human population. Functional genetics and genomics tools can help us to understand the function of different genes and to engineer beneficial changes. In this study, we used a promoter capture assay to sequence 2-kb regions upstream of all high-confidence annotated genes from 1,513 mutagenized plants from the tetraploid wheat variety Kronos. We identified 4.3 million induced mutations with an accuracy of 99.8%, resulting in a mutation density of 41.9 mutations per kb. We also remapped Kronos exome capture reads to Chinese Spring RefSeq v1.1, identified 4.7 million mutations, and predicted their effects on annotated genes. Using these predictions, we identified 59% more nonsynonymous substitutions and 49% more truncation mutations than in the original study. To show the biological value of the promoter dataset, we selected two mutations within the promoter of the
VRN-A1
vernalization gene. Both mutations, located within transcription factor binding sites, significantly altered
VRN-A1
expression, and one reduced the number of spikelets per spike. These publicly available sequenced mutant datasets provide rapid and inexpensive access to induced variation in the promoters and coding regions of most wheat genes. These mutations can be used to understand and modulate gene expression and phenotypes for both basic and commercial applications, where limited governmental regulations can facilitate deployment. These mutant collections, together with gene editing, provide valuable tools to accelerate functional genetic studies in this economically important crop.
The guanine nucleotide exchange factor Rin-like controls Tfh cell differentiation via CD28 signaling
Authors: Sandner Lisa , Alteneder Marlis , Rica Ramona , Woller Barbara , Sala Eleonora , Frey Tobias , Tosevska Anela , Zhu Ci , Madern Moritz , Khan Matarr , Hoffmann Pol , Schebesta Alexandra , Taniuchi Ichiro , Bonelli Michael , Schmetterer Klaus , Iannacone Matteo , Kuka Mirela , Ellmeier Wilfried , Sakaguchi Shinya , Herbst Ruth , Boucheron Nicole
Published: September 2023

T follicular helper (Tfh) cells are essential for the development of germinal center B cells and high-affinity antibody-producing B cells in humans and mice. Here, we identify the guanine nucleotide exchange factor (GEF) Rin-like (Rinl) as a negative regulator of Tfh generation. Loss of Rinl leads to an increase of Tfh in aging, upon in vivo immunization and acute LCMV Armstrong infection in mice, and in human CD4+ T cell in vitro cultures. Mechanistically, adoptive transfer experiments using WT and Rinl-KO naïve CD4+ T cells unraveled T cell–intrinsic GEF-dependent functions of Rinl. Further, Rinl regulates CD28 internalization and signaling, thereby shaping CD4+ T cell activation and differentiation. Thus, our results identify the GEF Rinl as a negative regulator of global Tfh differentiation in an immunological context and species-independent manner, and furthermore, connect Rinl with CD28 internalization and signaling pathways in CD4+ T cells, demonstrating for the first time the importance of endocytic processes for Tfh differentiation.
ANO1, CaV1.2, and IP3R form a localized unit of EC-coupling in mouse pulmonary arterial smooth muscle
Authors: Akin Elizabeth J. , Aoun Joydeep , Jimenez Connor , Mayne Katie , Baeck Julius , Young Michael D. , Sullivan Brennan , Sanders Kenton M. , Ward Sean M. , Bulley Simon , Jaggar Jonathan H. , Earley Scott , Greenwood Iain A. , Leblanc Normand
Published: September 2023

Pulmonary arterial (PA) smooth muscle cells (PASMC) generate vascular tone in response to agonists coupled to Gq-protein receptor signaling. Such agonists stimulate oscillating calcium waves, the frequency of which drives the strength of contraction. These Ca2+ events are modulated by a variety of ion channels including voltage-gated calcium channels (CaV1.2), the Tmem16a or Anoctamin-1 (ANO1)-encoded calcium-activated chloride (CaCC) channel, and Ca2+ release from the sarcoplasmic reticulum through inositol-trisphosphate receptors (IP3R). Although these calcium events have been characterized, it is unclear how these calcium oscillations underly a sustained contraction in these muscle cells. We used smooth muscle–specific ablation of ANO1 and pharmacological tools to establish the role of ANO1, CaV1.2, and IP3R in the contractile and intracellular Ca2+ signaling properties of mouse PA smooth muscle expressing the Ca2+ biosensor GCaMP3 or GCaMP6. Pharmacological block or genetic ablation of ANO1 or inhibition of CaV1.2 or IP3R, or Ca2+ store depletion equally inhibited 5-HT-induced tone and intracellular Ca2+ waves. Coimmunoprecipitation experiments showed that an anti-ANO1 antibody was able to pull down both CaV1.2 and IP3R. Confocal and superresolution nanomicroscopy showed that ANO1 coassembles with both CaV1.2 and IP3R at or near the plasma membrane of PASMC from wild-type mice. We conclude that the stable 5-HT-induced PA contraction results from the integration of stochastic and localized Ca2+ events supported by a microenvironment comprising ANO1, CaV1.2, and IP3R. In this model, ANO1 and CaV1.2 would indirectly support cyclical Ca2+ release events from IP3R and propagation of intracellular Ca2+ waves.
Dimension of the isometry group in spacetimes with an invariant frame
Authors: Antonio Sáez Juan , Mengual Salvador , Josep Ferrando Joan
Published: September 2023

The necessary and sufficient conditions for a spacetime with an invariant frame to admit a group of isometries of dimension r are given in terms of the connection tensor H associated with this frame. In Petrov–Bel types I, II and III, and in other spacetimes where an invariant frame algebraically defined by the curvature tensor exists, the connection tensor H is given in terms of the Weyl and Ricci tensors without an explicit determination of the frame. Thus, an intrinsic, deductive, explicit and algorithmic characterization of these spacetimes follows. Some examples show that this algorithm can be easily implemented on the xAct Mathematica suite of packages.
FBG displacement sensor with hyperbolic flexible hinge structure
Authors: Shi Yan , Wang Chenxu , Cai Jianxian , Gao Zhitao , Zhang Yuzi
Published: September 2023

This paper proposes a design method for a fiber Bragg grating (FBG) displacement sensor with a hyperbolic flexible hinge structure. A compact FBG displacement sensor with strong micro displacement measurement capability was fabricated. The final assembly testing showed that the sensor achieved good linearity with a linearity of 0.53%F·S at a range of 50 mm. The sensitivity was measured as 24.45 pm mm−1, hysteresis error as 1.1%FS, and repeatability error as 0.659%. The testing results demonstrated that the fabricated FBG displacement sensor exhibited strong practicality and good stability, making it suitable for long-term displacement monitoring of slope safety.