bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modulation of excited state intramolecular proton transfer and intramolecular charge transfer pathways of symmetrical azines through micellar medium
Authors: Suhasini Ramalingam , Venkatasubramanian Ulagammal , Thiagarajan Viruthachalam 
Published: February 2024

AbstractThe photophysical studies of fluorescent probes in micellar medium can give a better insight about their interaction with biological membranes. This study attempts to access the photophysical properties of the dual emitting azine based probe diethylamino salicylidene azine dimer (DEASAD) in micellar media. DEASAD showed dual charge transfer emission due to the presence of open enol (480 nm) and closed enol (510 nm) forms in polar protic solvents. Upon increasing the concentration of ionic surfactants, there is a significant increase in the emission intensity of both the enol forms of DEASAD until premicellar concentration. After micellization, occurrence of a new anomalous keto form emission through excited state intramolecular proton transfer (ESIPT) was observed around 530 nm in ionic micelles and its intensity changes depend on the micellar surface charge. The emission studies revealed the position and interaction of DEASAD with the charge of micellar stern layer as confirmed through interaction of metal ion with the probe and control molecules with and without ESIPT and ICT moieties. In contrast, the new anomalous longer wavelength keto form of DEASAD emission was absent in neutral micelles like Triton X‐100.
Workers organizing in the platform economy: Local forms and global trends of collective action
Authors: Rafélis de Broves Olivier , Kang Minhyoung , Grohmann Rafael , Barcellos Victor , Gomes Mano Felipe , Yoon Cheolki , Jamil Rabih 
Published: February 2024

AbstractDistinctive features of the on‐demand work platforms made it theoretically improbable for workers to organize and for collective forms of protest to emerge. Their business model and work arrangements spatially isolate and socially individualize workers, subjectivizing them as competing micro‐enterprises rather than co‐workers. However, faced with the flood of the platforms on a global scale, collective actions of platform workers surged like a backwash, especially in the ride‐hailing and food delivery sectors, during the last decade. Observers witnessed a great variety in the combination of actors involved and repertoire of actions mobilized worldwide. Despite this diversity, some common global trends can be sketched out. Through a literature review focused on Europe, Latin America, North America and Asia, this article shows that workers struggle globally to build a collective actor, through an original combination of new and old forms of protest. They ought to compensate for their weak marketplace bargaining power by leveraging their discursive, associational, coalitional and workplace bargaining powers.
Imaging diagnosis: CT characteristics of a retrobulbar hibernoma in a dog
Authors: Craig Cameron J , Young Benjamin D , Andries Courtney V , Aschenbroich Sophie A 
Published: February 2024

AbstractA 12‐year‐old female spayed Beagle was referred for investigation of exophthalmos. CT revealed a well‐defined, retrobulbar mass causing rostro‐dorsal displacement of the left globe. The mass had a mildly heterogeneous precontrast soft tissue attenuation with mild heterogeneous enhancement following iohexol administration. The mass was surgically removed en bloc with an orbital exenteration. Histopathology confirmed the mass to be a hibernoma, a benign tumor of brown adipose tissue. Hibernomas have CT characteristics consistent with both benign and malignant adipose tumors and may be underrecognized by radiologists.
Genetic influences on motor learning and performance and superperforming mutants revealed by random mutational survey of the mouse genome
Authors: Jakkamsetti Vikram , Ma Qian , Angulo Gustavo , Scudder William , Beutler Bruce , Pascual Juan M. 
Published: February 2024

AbstractEvolution depends upon genetic variations that influence physiology. As defined in a genetic screen, phenotypic performance may be enhanced or degraded by such mutations. We set out to detect mutations that influence motor function, including motor learning. Thus, we tested the motor effects of 36,444 non‐synonymous coding/splicing mutations induced in the germline of C57BL/6J mice with N‐ethyl–N‐nitrosourea by measuring changes in the performance of repetitive rotarod trials while blinded to genotype. Automated meiotic mapping was used to implicate individual mutations in causation. In total, 32,726 mice bearing all the variant alleles were screened. This was complemented with the simultaneous testing of 1408 normal mice for reference. In total, 16.3% of autosomal genes were thus rendered detectably hypomorphic or nullified by mutations in homozygosity and motor tested in at least three mice. This approach allowed us to identify superperformance mutations in Rif1, Tk1, Fan1 and Mn1. These genes are primarily related, among other less well‐characterized functions, to nucleic acid biology. We also associated distinct motor learning patterns with groups of functionally related genes. These functional sets included, preferentially, histone H3 methyltransferase activity for mice that learnt at an accelerated rate relative to the remaining mutant mice. The results allow for an estimation of the fraction of mutations that can modify a behaviour influential for evolution such as locomotion. They may also enable, once the loci are further validated and the mechanisms elucidated, the harnessing of the activity of the newly identified genes to enhance motor ability or to counterbalance disability or disease.
imageKey points
We studied the effect of chemically induced random mutations on mouse motor performance.
An array of mutations influenced the rate of motor learning.
DNA regulation genes predominated among these mutant loci.
Several mutations in unsuspected genes led to superperformance.
Assuming little‐biased mutagenicity, the results allow for an estimation of the probability for any spontaneous mutation to influence a behaviour such as motor learning and ultimate performance.
Analysis and Modeling of Turbulence Anisotropy of a Swirled Hot Streak Flow
Authors: Wingel Christopher , Binder Nicolas , Bousquet Yannick , Boussuge Jean-François , Buffaz Nicolas , Le Guyader Sébastien 
Published: February 2024

Abstract
This study is carried out in the context of hot streak flows in high-pressure turbines, for which a correct prediction of the temperature evolution is required. The present work particularly focuses on the turbulence anisotropy analysis of a swirled hot streak flow in a bent channel representative of a nozzle guide vane (NGV) passage of a high-pressure turbine. Large-eddy simulations are conducted with the in-house solver IC3 in order to measure and characterize the anisotropy of turbulence. Moreover, to evaluate turbulence modeling, steady simulations of the bent channel are performed with the elsA software, which solves the Reynolds-averaged Navier–Stokes (RANS) equations. LES is first used to complete a turbulent kinetic energy (TKE) budget that enables to understand the energetic transfers associated with turbulence. This budget reveals two distinct zones where turbulence activity is impacted when the curvature is reached. The analysis of the anisotropy of turbulence based on two metrics highlights a misalignment of the Reynolds stress tensor and the mean strain-rate tensor (Schmitt's criterion), and a strong anisotropy developing inside the bent duct (Lumley's analysis) that may cause the failure of the classical RANS turbulence models based on Boussinesq's hypothesis. To check this hypothesis, RANS is positioned against LES with different turbulence models that accounts or not for the anisotropy of turbulence. Both turbulence activity (TKE budgets, Lumley's analysis) and aerothermal fields (radial distributions) are compared. Results show that Explicit Algebraic Reynolds Turbulence Models (EARSM) enable to better account for the anisotropy of turbulence, which in turn promote a better prediction of temperature, both in terms of intensity and trajectory.
Development and Verification of a Higher-Order Computational Fluid Dynamics Solver
Authors: Tyson William C. , Jackson Charles W. , Roy Christopher J. 
Published: February 2024

Abstract
Over the past two decades, higher-order methods have gained much broader use in computational science and engineering as these schemes are often more efficient per degree-of-freedom at achieving a prescribed error tolerance than lower-order methods. During this time, higher-order variants of most discretization schemes, such as finite difference methods, finite volume methods, and finite element methods, have emerged. The finite volume method is arguably the most widely used discretization technique in production-level computational fluid dynamics solvers due to its robustness and conservation properties. However, most finite volume solvers only employ a conventional second-order scheme. To leverage the benefits of higher-order methods, the higher-order finite volume method seems the most natural for those seeking to extend their legacy solvers to higher-order. Nonetheless, ensuring higher-order accuracy is maintained is quite challenging as the implementation requirements for a higher-order scheme are much greater than those of a lower-order scheme. In this work, a methodology for verifying higher-order finite volume codes is presented. The higher-order finite volume method is outlined in detail. Order verification tests are proposed for all major components, including the treatment of curved boundaries and the higher-order solution reconstruction. System-level verification tests are performed using the weak form of the method of manufactured solutions. Several canonical verification cases are also presented for the Euler and laminar Navier–Stokes equations.
Searching for Suitable Binary Fluid for an Ejector Heat Pump for Domestic Water Heating
Authors: Wang Pengtao , Abu-Heiba Ahmad , Mohammed Ramy H. , Spitzenberger Jeremy , Kowalski Stephen , Ismael Laith , Ma Hongbin , Nawaz Kashif 
Published: February 2024

Abstract
Water heating is a major source of energy consumption in the U.S. residential sector. Heat pumps can significantly increase the energy efficiency of water heating. An ejector heat pump (EHP) is a novel, thermally driven heat pump that uses an ejector as a thermocompressor. Choosing suitable working fluids is critical in developing high-performance EHPs. Therefore, this research screens binary fluid pairs (BFPs) for EHPs to produce domestic hot water at a high coefficient of performance (COP). The criteria for screening BFP candidates for EHP water heaters (EHPWHs) are established, and BFP candidates are shortlisted. This study identifies HFE7000, Novec649, HFE7100, HFE7200, and HFE7500 for the primary fluids and RE170, R600a, R600, and R1234ze(Z) for the secondary fluids. The thermodynamic model is employed to investigate the performance of EHPWHs using the shortlisted BFPs under various operating parameters, including the evaporation pressure of the primary working fluid in the high-temperature evaporator and the condensation temperature. The highest heating-cycle COP of 1.328 is achieved by an EHPWH operating with HFE7000/R600 at a condenser temperature of 50 °C and a pressure of 1.69 MPa in the high-temperature evaporator.
Limits on Kinetic Impact Deflection of Asteroids from Laboratory Hypervelocity Cratering and Disruption of Meteorites and Analogs
Authors: Flynn George J. , Durda Daniel D. , Strait Melissa M. , Macke Robert J. 
Published: February 2024

Abstract
Successful deflection of a hazardous asteroid by kinetic impact requires cratering without disruption in order to avoid possibly leaving a large fragment of the asteroid on a collision course with Earth. A critical issue is the determination of the maximum change in velocity, and thus the orbital change, that can be imparted to asteroid material by a single hypervelocity kinetic impact while producing only cratering rather than fragmentation. Porosity, strength, mineralogy, and hydration influence the response of a target to hypervelocity impact. To investigate the maximum velocity that can be transferred by a single kinetic impact we performed a series of laboratory-scale hypervelocity impact cratering and disruption measurements on two types of anhydrous asteroid samples, the Northwest Africa (NWA) 869 ordinary chondrite meteorite and the NWA 4502 carbonaceous chondrite meteorite, using the NASA Ames Vertical Gun Range. Our results demonstrate that if disruption is to be avoided there is a factor of seven difference in the maximum velocity that can be imparted by a single kinetic impact between these two types of asteroid material. To investigate the effect of hydration on the maximum velocity transfer we impacted laboratory-prepared simulant of a hydrous carbonaceous meteorite target and determined that its behavior was similar to that of the NWA 4502 targets. Our results indicate that the maximum velocity change that can be imparted by a single kinetic impactor to this carbonaceous meteorite target is only ~0.27 m/s. This suggests that multiple kinetic impacts may be required for non-disruptive deflection of many Potentially Hazardous Asteroids, particularly the weaker carbonaceous asteroids.
In-Situ Observation of Stress-Field Propagation and Damage Formation in Hypervelocity-Impacted Glass Materials
Authors: Kawai Nobuaki , Uemura Tomo , Watanabe Kazuma , Hasegawa Sunao 
Published: February 2024

Abstract
Hypervelocity impact experiments have been conducted on quartz glass and soda-lime glass to observe directly the impactinduced damage process progressing inside materials. Stress wave propagation and damage evolution associated with hypervelocity impact are visualized by employing the Edge-on Impact technique coupled with the polarized light shadowgraphy or scattered-light imaging method using an ultra-high-speed video camera. Recorded images clearly show how stress waves propagate and interact with each other, and how damages form and propagate during hypervelocity-impact events. A comparison of damage structures between quartz and soda-lime glasses reveals that differences in the short-range order of atomic configurations can affect the formation of macroscopic impact damage in amorphous materials such as glass. In experiments with a target consisting of two soda-lime glass components stacked in the direction of the ballistic axis, it is observed that damage form and propagate in the vicinity of the interface due to the interaction between the contact interface of the two glass components and the stress wave.
Numerical Modeling of High-Speed Impacts Involving thin Film
Authors: Kupchella Ryan , Ruoff Chaz 
Published: February 2024

Abstract
A parallelized approach for simulating tearing in thin material with a hydro-structural code is presented. The approach is built upon the shell finite element formulation and incorporates a simple remeshing scheme to facilitate material separation behind propagating tears. Tear propagation is handled using an implementation of the Virtual Crack Closure Technique (VCCT) to predict fracture based on the homogenized critical strain energy release rate (Gc). The approach is demonstrated with a simulation of an impact event from a joint JAXA/NASA series of light gas gun tests. A marked improvement in model outcome with the use of the VCCT implementation is demonstrated through quantitative and qualitative comparisons between numerical debris characteristics and experimental data.
Mesoscale Modeling of High-Velocity Impact on Thick-Section Woven Composites
Authors: Meyer Christopher S. , Gillespie John W. , Haque Bazle Z. (Gama) 
Published: February 2024

Abstract
This work presents an approach for modeling high-velocity impact on multi-layered plain weave composites. This approach resolves plain weave architecture with mesoscale detail, and applies the continuum assumption to the microscale. Models include rate-dependent material constitutive, damage and failure behavior, and rate-dependent cohesive interfacial failure. Rate-dependent cohesive traction-separation laws were derived from previously published microscale models of fracture. The modeling approach was validated by comparing the predicted impact versus residual velocity (VI-VR) response to previously published experimental results. Finally, the model is used to predict the VI-VR response for a 22-layer composite and the results are compared with experimental results from the literature. Good correlation is shown between experiment and model predictions.
2D VS 3D: Does Perspective Affect Thermography Temperature Values
Authors: Cagle Colton , Croessmann Charles L. , Ritchie Cole , Muniz Frank , Pantoya Michelle 
Published: February 2024

Abstract
Thermography is a common diagnostic for measuring spatially resolved surface temperatures. Extreme environments such as high-velocity impact testing employ thermography to probe fireball dynamics for modeling and simulation efforts. However, emissivity and related optical density are major roadblocks for accuracy. In this study, a variety of reactive projectiles are launched at 1300m/s and observed with single camera thermography from two 90° perspectives. The effect of flame shape on optical density and subsequently emissivity is compared between the different viewing angles. Trends indicate that asymmetric flames create varying optical densities between perspectives, resulting in up to 7% difference in reported median temperatures for the same flame. A maximum of 11% total difference is reported, with 6% due entirely to optical density effects. It is concluded that different viewing angles provide valuable insight into optical density and emissivity functions, and uncertainties of reported temperatures should account for this potential inaccuracy.
Railgun Launch of Cylindrical and Conical Projectiles at Muzzle Velocities up to 2100 M/S
Authors: Reck B. , Alouahabi F. , Hassler Q. , Schneider M. 
Published: February 2024

Abstract
Electromagnetic railguns are able to launch projectiles at velocities beyond 2500 m/s. The French-German Research Institute of Saint-Louis ISL has been operating railguns of various sizes for more than 25 years, ranging from small caliber (10-mm) guns to the 6-m long NGL60 launcher with a 60 mm square caliber. In this work, the launch and sabot discard process of projectiles is investigated, using ISL’s 3-m long railgun of caliber 25 mm. Two different types of projectiles are examined. The first type has a cylindrical geometry with a conical nose. By choosing different lengths, the projectile mass ranges from 15 to 60 grams. A thread allows for the transfer of the acceleration load from the armature-sabot petals to the cylinder. The muzzle velocities of this test series are located between 1300 m/s and 2100 m/s. The second type is a coneshaped projectile, made of copper alloy, with a base diameter of 20 mm and a round nose. Velocities up to about 1600 m/s were achieved with this type. Relevant insight in the mechanisms limiting the muzzle velocity could be obtained, which proves beneficial for future launcher up-scaling. The particular feature of the launch package design for both types of projectiles is the common separation of armature and sabot. Symmetrical discard makes sure that their craters of impact do not interfere with the projectile impact in the center region of the target plate.
Simulating Hypervelocity Impacts on Cfrp with a Discrete Element Approach
Authors: Watson Erkai , Durr Nathanaël , Murillo Jose-Luis Sandoval , Büttner Markus , Matura Pascal 
Published: February 2024

Abstract
Numerical simulations provide a powerful tool for investigating satellite breakups resulting from hypervelocity impact, and a discrete element simulation method has been shown to be well suited to model the fragmentation that materials undergo upon impact at high velocities. In this paper, we describe new developments to a discrete element simulation method to allow the modeling of orthotropic materials, specifically carbon fiber reinforced polymers which are commonly used in modern satellites. We model carbon fiber reinforced polymers by using different parameters for fiber and matrix materials in our discrete model. We calibrate our carbon fiber reinforced polymer model’s two free parameters with experimental hypervelocity impact data from literature. Finally, we demonstrate the numerical method’s applicability to simulate the satellite breakups with two simulations: a non-catastrophic sphere-CubeSat impact and a catastrophic CubeSat-CubeSat impact. We compare these scenarios, using aluminum and carbon fiber reinforced polymer CubeSats, to fragment size distributions predicted by the NASA standard satellite breakup model.
Ultra-High-G Ballistic Impact into Water Targets
Authors: Wilson Natasha , White Caleb , Chen Alex , Curtis Shane , Lifke Don 
Published: February 2024

Abstract
Creation of a Sandia internally developed, shock-hardened Recoverable Data Recorder (RDR) necessitated experimentation by ballistically-firing the device into water targets at velocities up to 5,000 ft/s. The resultant mechanical environments were very severe—routinely achieving peak accelerations in excess of 200 kG and changes in pseudo-velocity greater than 38,000 inch/s. High-quality projectile deceleration datasets were obtained though high-speed imaging during the impact events. The datasets were then used to calibrate and validate computational models in both CTH and EPIC. Hydrodynamic stability in these environments was confirmed to differ from aerodynamic stability; projectile stability is maintained through a phenomenon known as “tail-slapping” or impingement of the rear of the projectile on the cavitation vapor-water interface which envelopes the projectile. As the projectile slows the predominate forces undergo a transition which is outside the codes’ capabilities to calculate accurately, however, CTH and EPIC both predict the projectile trajectory well in the initial hypervelocity regime. Stable projectile designs and the achievable acceleration space are explored through a large parameter sweep of CTH simulations. Front face chamfer angle has the largest influence on stability with low angles being more stable.
Monitoring Readiness to Train and Perform in Female Football: Current Evidence and Recommendations for Practitioners
Authors: Beato Marco , Madsen Esben Elholm , Clubb Jo , Emmonds Stacey , Krustrup Peter 
Published: February 2024

Purpose: Monitoring player readiness to train and perform is an important practical concept in football. Despite an abundance of research in this area in the male game, to date, research is limited in female football. The aims of this study were, first, to summarize the current literature on the monitoring of readiness in female football; second, to summarize the current evidence regarding the monitoring of the menstrual cycle and its potential impact on physical preparation and performance in female footballers; and third, to offer practical recommendations based on the current evidence for practitioners working with female football players. Conclusions: Practitioners should include both objective (eg, heart rate and countermovement jump) and subjective measures (eg, athlete-reported outcome measures) in their monitoring practices. This would allow them to have a better picture of female players’ readiness. Practitioners should assess the reliability of their monitoring (objective and subjective) tools before adopting them with their players. The use of athlete-reported outcome measures could play a key role in contexts where technology is not available (eg, in semiprofessional and amateur clubs); however, practitioners need to be aware that many single-item athlete-reported outcome measures instruments have not been properly validated. Finally, tracking the menstrual cycle can identify menstrual dysfunction (eg, infrequent or irregular menstruation) that can indicate a state of low energy availability or an underlying gynecological issue, both of which warrant further investigation by medical practitioners.