bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulations Predicting the Effects of Detonation Velocity on the Speed and Temperature of Shaped Charge Jets
Authors: Doney Robert 
Published: February 2024

Abstract
In this report, I evaluate the effects of a warhead's detonation velocity on the resulting speed and thermodynamic state of shaped charge jets using the multiphysics code, ALEGRA. Specifically, I investigate a 65-mm, bare, shaped charge jet, generated from explosives that feature detonation velocities ranging from 6.84 to 9.11 km/s with a fixed geometry. Data showed a general trend for all cases: a hot axis that cools off with increasing radius according to a second-order polynomial. At higher detonation velocities, the jet axis is predicted to be liquid. This is coincident with copper material that is faster along the axis and leads the jet tip, forming a proboscis. At slower deteonation velocities this phenomena vanishes and the jet appears to be a solid.
Study on Hypervelocity Impact of SRM Slag with Voids
Authors: Fujii Masanori , Nitta Kumi , Higashide Masumi , Akahoshi Yasuhiro , Koura Takao 
Published: February 2024

Abstract
Solid rocket motors are mainly used for launching small satellites because they have a small number of parts, simple structures, and high responsiveness. However, there are concerns about solid rocket motors, which release solid rocket motor slag (SRM slag). The SRM slag is derived from aluminum powder in a solid matrix and released as agglomerated alumina into outer space before and after the solid rocket motor is cutoff. It has been confirmed that voids inside themselves in combustion tests in a vacuum conducted by JAXA. In this paper focusing on SRM slag with voids, we simulated its impact with diameters ranging from 1 mm to 10 mm, with porosities ranging from 0 % to 80 %, and with impact velocities of 2-15 km/s towards enough thick targets. We investigated the potential danger of SRM slag with voids using AUTODYN-2D. In addition, we calculated the ballistic limit curve (BLC) for each porosity of SRM slag based on the penetration depths obtained by the numerical simulations and compared BLCs in SRM slag and space debris made of aluminum alloy.
Case Study of Meteoroid Fluence on a Mars Sample Return Mission
Authors: Jenkin Alan B , Peterson Glenn E. , Steward Katie , Needels Jacob T. , Gage Peter J. , Gee Ken , Coates Ashley M. , White Todd R. , Squire Michael D. 
Published: February 2024

Abstract
This paper presents results from an analysis to assess the fluence of meteoroids on the Mars Sample Return Campaign Micrometeoroid Protection System (MMPS) and probability of damage to the Earth Entry System Thermal Protection System (TPS). Results are presented for the mission Outbound trajectory from Earth to Mars. The MEM3 meteoroid environment model was used for the assessment. Results are presented showing the reduction in fluence on cube faces and on the MMPS that can be achieved by selection of an anti-velocity orientation of the MMPS. A methodology is presented that determines the cumulative fluence on the MMPS using the MEM3 meteoroid fluxes and the spacecraft attitude profile over the trajectory. Resulting distributions of fluence over impact velocity, angle, and mass are presented. The fluence results are used to establish velocity-angle scenarios for hydrocode simulation and to assess net damage fluence to the TPS. Example tables containing Smooth Particle Hydrodynamics Code (SPHC) simulation scenarios as well as hypothetical hydrocode simulation scenarios for illustration purposes are presented. The tables present the resulting net damaging fluence to the TPS for each scenario and the total across the scenarios. Additionally, examples of CTH hydrocode simulation are included, demonstrating their use for determining critical impactor across the impactor parameter space, and damage of impactors that penetrate the MMPS.
Failure of Fuel Tanks Due to High Velocity Projectiles Impact
Authors: Ji Yangziyi , Li Xiangdong , Zhou Lanwei , Chen Junliang 
Published: February 2024

Abstract
The impact of high-velocity projectiles on fluid-filled containers is a matter of interest in the study of vehicle and aircraft vulnerability. In this paper, tests of high-velocity projectiles impacting typical truck-integrated fuel tanks were conducted. It is found that during a certain range of projectile impact energy before the fuel tank wall begins to crack, the deformation of the fuel tank wall does not increase with the increase of the projectile impact energy, while maintaining a certain value. Besides, this value is the same for both entry and exit walls. Preliminary finite element analysis shows that the HRAM loading during the cavity oscillation phase contributes to the deformation of the exit wall most.
Quantitative Analysis of Physical Properties of Shaped Charge Jet by the use of IN-SITU Mass Analysis From X-RAY Image Processing (I-MAX)
Authors: Saito Fumikazu , Kishimura Hiroaki , Takizawa Yutaka , Okada Yohsuke , Ogino Takashi , Nakashita31 Mitsuyori 
Published: February 2024

Abstract
Al-shaped-charge-jet (Al SCJ) generated from conical liner under explosive shock loading is observed using a hard flash xray and x-ray imaging plate. An analytical method termed insitu mass analysis from x-ray image processing (i-MAX) was utilized to estimate the mass, velocity, and kinetic energy of the SCJ in this study. The mass distributions in the SCJ showed the tendency to decrease toward the jet's tip, except in the vicinity of the jet's tip. Kinetic energy showed the maximum value (2080±582 J) at the jet's tip. The collision/penetration experiment against an iron target block was conducted to evaluate the penetration ability of the Al SCJ. The Al SCJ impact against the Fe target observed no bulk aluminum or slag on the penetration hole. These results suggest that the shape (depth and width) and condition (residuals in the hole) of the penetration holes also strongly depend on the metallic characteristics of the liner and the physical properties of the SCJ. These results suggest that the shape and condition of the penetration holes strongly depend on the liner's metallic characteristics (melting point) and the physical property (kinetic energy) of the SCJ.
Transition Regime between High-Velocity and Hypervelocity Impact and Related Energy Partitioning in Metals: State-of-the-Art Review, Characterization, and Modeling
Authors: Signetti Stefano , Heine Andreas 
Published: February 2024

Abstract
We discuss how established modeling approaches for metals in terminal ballistics can be extended towards higher impact velocities, yet below the threshold of purely hydrodynamic behavior. While at the upper bound of the high-velocity penetration regime the effects of material strength and failure are dominating, the ideal hydrodynamic behavior is still not achieved until velocities of several kilometers per second. The transition regime in between sees a gradual shift from effects dominated by strength to those connected with the increase of internal energy, such as thermal softening and melting. Therefore, the coexistence of different multi-physics phenomena makes this intermediate domain of paramount interest, especially for computational scientists. A physics-based characterization of the transition regime is discussed alongside penetration data, partition measurements, and experimental observation from different literature sources. The key results of an extensive literature review with a focus on the relevant phenomena for impact modeling of metals up to hypervelocity conditions are presented. Limits and prospects of hydrocode simulation for energy partitioning computation as well as relatively novel approaches for the field of impact research are discussed. This conference paper summarizes the recent research on the topic conducted in our group. Related results and discussions are taken from earlier publications by the authors on which the text of this contribution is based.
Experimental Investigation of Impact Flash Emission and Ejection Phenomena in Hypervelocity Impacts on Metals
Authors: Simpson Gary , Shaeffer Matt , Moreno Justin , Ramesh KT 
Published: February 2024

Abstract
A common feature of many high-velocity and hypervelocity projectile impacts is an intense burst of optical emission commonly called an impact flash. The impact flash can easily obscure observation of the earliest moments of projectile contact and penetration, making it somewhat detrimental to the experimentalist. However, the impact flash contains signatures of the earliest, most energetic processes at work during this critical phase and potentially offers valuable information for applications such as remote impact damage assessment. A multitude of mechanisms and interactions can contribute to the impact flash; a thorough understanding of the structure and nature of the flash generation itself under the experimental conditions of relevance is necessary to properly interpret any flash emission measurement. This work attempts to investigate the nature of impact flash emission for spherical impacts on metals under experimental conditions common to impact research experiments at the HyFIRE facility at Johns Hopkins. Time-resolved emission spectroscopy, photometry, and ultrahigh- speed multispectral imaging are used to identify the emission characteristics and structure of the radiating material. Under these conditions, the impact flash is observed to originate almost entirely from the rapid atmospheric ablation of jetted ejecta and debris.
Crater Ejecta Fragments Size and Shape From Hypervelocity Impacts into AL 2024-T351 Aluminum From 4 to 6 KM/S
Authors: Walker James D. , Chocron Sidney , Grosch Donald J. , Heim F. Michael 
Published: February 2024

Abstract
Utilizing a large two-stage light gas gun, 3-cm-diameter spheres were impacted into Al 2024-T351 targets. The fragments were collected from the floor of the impact chamber and were analyzed. In particular, there is interest as to the fragment size distribution and the fragment shape distribution. The fragments were sorted in size, and those from roughly 0.1 g to 35 g were individually tabulated. This allowed the development of a fragment size distribution for these fragments. Then, all the fragments were optically analyzed to provide a quantitative characterization of their shape. The fragments are predominately flat, a shape that appears to correlate with an intersecting shear plane mechanism for the fragment formation in the crater formation. The fragment distribution shows that there are two different fragment formation mechanisms, which it is concluded are due to fragments formed in the interior of the crater entirely of interacting shear planes vs. those whose formation is influenced by the target free surface. The results are compared to other work on fragmentation.
Analysis of Hypervelocity-Impacted thin Films for Space Applications
Authors: Ward Melissa A. , Anz-Meador Phillip D. , Cowardin Heather M. 
Published: February 2024

Abstract
Exposure to the harsh space environment and hypervelocity impacts from micrometeoroids and small orbital debris can affect space operations through long-term degradation of spacecraft materials, surfaces, or systems. Multi-layer insulation (MLI) and coated, polyimide films are spacecraft materials commonly found on the external surfaces of spacecraft for thermal control and protection. Characterizing the damage to these exposed materials with in situ and laboratory measurements can better inform spacecraft designers and operators in understanding and mitigating surface or system degradation. In this paper, we examine flown Hubble Space Telescope (HST) Equipment Bay 5 MLI and coated, polyimide ground test articles to characterize hypervelocity impact damage. Impact feature cavities are inspected to identify damage, which can validate long-term degradation models, improve thermal management systems, or improve accuracy of damage predictions. An overview of the impact characterization using optical microscopy, narrowband spectroscopy, and Scanning Election Microscopy/Energy Dispersive X- ray (SEM/EDX) of the two materials is presented. Observations of robustness in the space environment, as well as a detailed assessment of cratering and penetration statistics for the space-exposed sample, also are discussed.
Prediction and Enhancement of Thermal Protection Systems from Meteoroid Damage using a Smooth Particle Hydrodynamic Code
Authors: Williamsen Joel , Stellingwerf Robert , Evans Steve , Squire Michael 
Published: February 2024

Abstract
Interplanetary spacecraft are exposed to meteoroid fluxes that range in speeds from 10 to 72 km/sec, far above the capability of today’s test facilities to provide predictions for the likelihood of spacecraft critical penetration. Of special interest are sample return missions, which (though protected by shielding) must often survive years of exposure to the meteoroid environment in order to re-enter Earth’s atmosphere with their scientific cargo.
This paper describes the simulation of meteoric material damage to thermal protection systems (TPS) housed beneath protective “garage” (shielding) enclosures using the Smooth Particle Hydrodynamics Code (SPHC) operated by the Institute for Defense Analyses and Stellingwerf Consulting in support of ongoing NASA tasks. The study outlined in this paper considered the impact effect of both meteoric materials such as iron, ice, and chondrites (dunnite), and non-meteoric materials such as aluminum and nylon against both external shielding materials (single and dual aluminum bumpers) and Heat shield for Extreme Entry Environments Technology (HEEET) TPS materials, used alone and in conjunction with shielding. A general predictive damage equation to HEEET TPS is developed from these SPHC simulations for velocities up to 70 km/sec.
Experiments on the Survivability of Extremophiles
Authors: Zhao Lily , Perez-Fernandez Cesar A. , DiRuggiero Jocelyne , Ramesh K. T. 
Published: February 2024

Abstract
The ability of terrestrial microorganisms to survive extreme conditions is an important consideration for developing and determining mission criteria, especially for future sample return missions. Of the numerous extreme conditions in space, the effect of impact is an important one for planetary protection. Impacts are complex phenomena with conditions that vary widely but typically involve high stresses sustained for short times. We aim to adapt the pressure-shear plate impact experiment to investigate how impact stresses affect the survival of microorganisms (in particular, extremophiles). Experiments are underway on Deinococcus radiodurans to validate the experimental design and establish testing protocols for such extremophiles.
Validity and Reliability of Finger-Strength Testing in 6 Common Grip Techniques for the Assessment of Bouldering Ability in Men
Authors: Söderqvist Karl , Identeg Fredrik , Zimmerman Jonas , Senorski Eric Hamrin , Sansone Mikael , Hedelin Henrik 
Published: February 2024

Objective: To determine the criterion validity and test–retest reliability of isometric finger-strength testing in 6 differentiated grip techniques for the assessment of bouldering ability among male climbers. Methods: We recruited participants at climbing gyms in Sweden and through online advertisements. We included climbers over 15 years of age with a minimum bouldering performance level of 17 International Rock Climbing and Research Association (IRCRA) for men and 15 IRCRA for women. We tested unilateral, maximal isometric peak finger strength in the front 3 drag, half crimp, closed crimp, 35 sloper, 45 × 90-mm, and 90 × 90-mm pinch through maximal force deloaded of a force plate. We analyzed criterion validity, test–retest reliability, and capacity to determine bouldering performance ability using a stepwise multivariable regression model. Results: Women were excluded from the analysis due to insufficient sample size (n = 16). Thirty-two male participants were included in the primary analysis. The median (interquartile range) age in the advanced and elite group was 27 (25; 35) and 23 (22; 32) years, respectively. The half crimp for the participants’ weak and strong hand displayed the highest ability to determine bouldering grade performance, explaining 48% to 58% of the variance. In the stepwise regression, maximal strength in the half crimp and the front 3 drag collectively explained 66% of the variance for performance. Conclusion: Strength in the half crimp proved the most important performance indicator. The results of this study provide a reliable and valid framework for maximal isometric peak finger-strength testing in advanced and elite male boulderers.
SMU_1361c regulates the oxidative stress response of
Streptococcus mutans
Authors: Yu Shuxing , Ma Qizhao , Huang Jun , Liu Yaqi , Li Jing , Wang Yan , Gong Tao , Zhang Qiong , Zou Jing , Li Yuqing 
Published: February 2024

ABSTRACT

Dental caries is the most common chronic infectious disease around the world and disproportionately affects the marginalized socioeconomic group.
Streptococcus mutans
, considered a primary etiological agent of caries, depends on the coordinated physiological response to tolerate the oxidative stress generated by commensal species within dental plaque, which is a critical aspect of its pathogenicity. Here, we identified and characterized a novel tetracycline repressor family regulator, SMU_1361c, which appears to be acquired by the bacteria via horizontal gene transfer. Surprisingly,
smu_1361c
functions as a negative transcriptional regulator to regulate gene expression outside its operon and is involved in the oxidative stress response of
S. mutans
. The
smu_1361c
overexpression strain UA159/pDL278-
1361c
was more susceptible to oxidative stress and less competitive against hydrogen peroxide generated by commensal species
Streptococcus gordonii
and
Streptococcus sanguinis
. Transcriptomics analysis revealed that
smu_1361c
overexpression resulted in the significant downregulation of 22 genes, mainly belonging to three gene clusters responsible for the oxidative stress response. The conversed DNA binding motif of SMU_1361c was determined by electrophoretic mobility shift and DNase I footprinting assay with purified SMU_1361c protein; therefore,
smu_1361c
is directly involved in gene transcription related to the oxidative stress response. Crucially, our finding provides a new understanding of how
S. mutans
deals with the oxidative stress that is required for pathogenesis and will facilitate the development of new and improved therapeutic approaches for dental caries.

IMPORTANCE

Streptococcus mutans
is the major organism associated with the development of dental caries, which globally is the most common chronic disease. To persist and survive in biofilms,
S. mutans
must compete with commensal species that occupy the same ecological niche. Here, we uncover a novel molecular mechanism of how tetracycline repressor family regulator
smu_1361c
is involved in the oxidative stress response through transcriptomics analysis, electrophoretic mobility shift assay, and DNase I footprinting assay. Furthermore, we demonstrated that
smu_1361c
mediates
S. mutans
sensitivity to oxidative stress and competitiveness with commensal streptococci. Therefore, this study has revealed a previously unknown regulation between
smu_1361c
and genes outside its operon and demonstrated the importance of
smu
_
1361c
in the oxidative stress response and the fitness of
S. mutans
within the plaque biofilms, which can be exploited as a new therapy to modulate ecological homeostasis and prevent dental caries.
Glutamate
-
dependent arginine biosynthesis requires the inactivation of
spoVG
,
sarA,
and
ahrC
in
Staphylococcus aureus
Authors: Reslane Itidal , Handke Luke D. , Watson Gabrielle F. , Shinde Dhananjay , Ahn Jong-Sam , Endres Jennifer L. , Razvi Fareha , Gilbert Emily A. , Bayles Kenneth W. , Thomas Vinai C. , Lehman McKenzie K. , Fey Paul D. 
Published: February 2024

ABSTRACT

Genome sequencing has demonstrated that
Staphylococcus aureus
encodes arginine biosynthetic genes
argDCJBFGH
synthesizing proteins that mediate arginine biosynthesis using glutamate as a substrate. Paradoxically, however,
S. aureus
does not grow in a defined, glutamate-replete medium lacking arginine and glucose (CDM-R). Studies from our laboratory have found that specific mutations are selected by
S. aureus
that facilitate growth in CDM-R. However, these selected mutants synthesize arginine utilizing proline as a substrate rather than glutamate. In this study, we demonstrate that the ectopic expression of the
argDCJB
operon supports the growth of
S. aureus
in CDM-R, thus documenting the functionality of this pathway. Furthermore, suppressor mutants of
S. aureus
JE2
putA::Tn,
which is defective in synthesizing arginine from proline, were selected on CDM-R agar. Genome sequencing revealed that these mutants had compensatory mutations within both
spoVG
, encoding an ortholog of the
Bacillus subtilis
stage V sporulation protein, and
sarA,
encoding the staphylococcal accessory regulator. Transcriptional studies document that
argD
expression is significantly increased when JE2
spoVG sarA
was grown in CDM-R. Lastly, we found that a mutation in
ahrC
was required to induce
argD
expression in JE2
spoVG sarA
when grown in an arginine-replete medium (CDM), suggesting that AhrC also functions to repress
argDCJB
in an arginine-dependent manner. In conclusion, these data indicate that the
argDCJB
operon is functional when transcribed
in vitro
and that SNPs within potential putative regulatory proteins are required to alleviate the repression.

IMPORTANCE

Although
Staphylococcus aureus
has the capability to synthesize all 20 amino acids, it is phenotypically auxotrophic for several amino acids including arginine. This work identifies putative regulatory proteins, including SpoVG, SarA, and AhrC, that function to inhibit the arginine biosynthetic pathways using glutamate as a substrate. Understanding the ultimate mechanisms of why
S. aureus
is selected to repress arginine biosynthetic pathways even in the absence of arginine will add to the growing body of work assessing the interactions between metabolism and
S. aureus
pathogenesis.
Complete genome sequence of deformed wing virus and black queen cell virus isolated from honeybees (
Apis mellifera
) in Argentina
Authors: Gonzalez Fernanda N. , Ferrufino Cecilia , Dus Santos María José , Carignano Hugo A. 
Published: February 2024

ABSTRACT

We report the complete genome sequence of deformed wing virus and black queen cell virus isolated from Argentinean’s honeybees. These sequence data will be valuable for future research on the viral variants present in the country and the development of strategies to control the spread of these viruses in apiaries.
Complete genome sequence of a Chinese
Pseudomonas syringae
pv.
actinidiae
strain Yunnan3.2
Authors: Yao Guanglu , Yang Fenghuan , Yu Chao , Wang Qin , Yang Yijuan , Chen Huamin 
Published: February 2024

ABSTRACT

Here, we report the complete genome sequence for
Pseudomonas syringae
pv.
actinidiae
strain Yunnan3.2, which was isolated from diseased kiwifruit grown in Yunnan province, China. The complete genome of Yunnan3.2 comprises a 6,564,315-bp chromosome with a GC content of 58.41% and a circular plasmid (74,466 bp).