cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.48577/jpl.yccda0
title: A Volume-Averaged Hyperbolic System of Governing Equations for Granular Flow Modeling with Phase Change

description: Typical granular flow simulations are based upon governing equations developed by local volume-averaging of flow properties, and then discretizing and solving the equations using numerical schemes. The formulation presented herein uses the basics of volume-averaging to derive a hyperbolic system of governing equations for modeling turbulent, dense granular flows. The Large Eddy Simulations (LES) framework is used for the fluid phase, whereas the solid phase equations are based on the Kinetic Theory. To obtain the LES equations, the volume-averaged equations are further manipulated by filtering the small scale fluctuations; these filtered terms must be modeled to recover their activity in the LES equations. Volume-averaging of the continuity, momentum and energy equations result in many integrals that are used to rigorously define the meaning of terms that have only been included in heuristic models in existing formulations. The concept of added mass, representing fluid that closely follows each particle in its boundary layer and wake and that travels with the particle velocity is used to develop a hyperbolic model for granular flows in the LES framework. Additionally, the pseudo-turbulent kinetic energy (PTKE), which is the turbulent kinetic energy in the fluid phase that arises due to the presence of the solid particles, is included in the formulation and it is shown how its contribution is distinct from turbulence and leads to different terms that must be modeled in the conservation equations. A test case represented by the interaction of a turbulent supersonic jet with a bed of solid particles is simulated and the results are analyzed to demonstrate hyperbolicity. This demonstration is performed by inspecting the eigenvalues of the governing system of equations at different spatial locations of the flow-field. By simulating an additional test case where the PTKE is set to be null and assessing the hyperbolicity of the results, it is demonstrated that the inclusion of PTKE has no role in bestowing hyperbolicity to the model.
DOI: 10.48577/jpl.80nxft
title: Planned Geological Investigations of the Europa Clipper Mission

description: Geological investigations planned for the Europa Clipper mission will examine the formation, evolution, and expression of geomorphic structures found on the surface. Understanding geologic features, their formation, and any recent activity are key inputs in constraining Europa’s potential for habitability. In addition to providing information about the moon’s habitability, the geologic study of Europa is compelling in and of itself. Here we provide a high-level, cross-instrument, and cross-discipline overview of the Europa Clipper mission’s planned geologic investigations. Europa’s fascinating collection of ice-focused geology provides an unparalleled opportunity to investigate the dynamics of icy shells, ice-ocean exchange processes, and global-scale tectonic and tidal stresses. We present an overview of what is currently known about the geology of Europa, from global to local scales, highlighting outstanding issues and open questions, and detailing how the Europa Clipper mission will address them. We describe the mission’s strategy for searching for and characterizing current activity in the form of possible active plumes, thermal anomalies, evidence for surface changes, and extremely fresh surface exposures. The complementary and synergistic nature of the data sets from the various instruments and their integration will be key to significantly advancing our understanding of Europa’s geology.
DOI: 10.48577/jpl.njvbhj
title: Planet Hunters TESS V: a planetary system including a transiting mini-Neptune in the habitable zone of a bright star in a binary

description: We report on the discovery and validation of a transiting long-period mini-Neptune orbiting a bright (V = 9.0 mag) G dwarf (TOI 4633; R = 1.05 R⊙, M = 1.10 M⊙). The planet was identified in data from the Transiting Exoplanet Survey Satellite by citizen scientists taking part in the Planet Hunters TESS project. Modelling of the transit events yields an orbital period of 271.9445+0.0039 −0.0040 days and radius of 3.2+0.20 −0.19 R⊕. The Earth-like orbital period and an incident flux of 1.56+0.20 −0.16 F⊕ places it in the optimistic habitable zone around the star. Doppler spectroscopy of the system allowed us to place an upper mass limit on the transiting planet and revealed a non-transiting planet candidate in the system with a period of ∼ 34 days. Furthermore, the combination of archival data dating back to 1905, with new high angular resolution imaging revealed a stellar companion orbiting the primary star with an orbital period of around 230 years and an eccentricity of about 0.91. The long period of the transiting planet, combined with the high eccentricity and close approach of the companion star makes this a valuable system for testing the formation and stability of planets in binary systems.
DOI: 10.48577/jpl.pmubcd
title: Searching for new physics in the solar system with tetrahedral spacecraft formations

description: Tetrahedral configurations of spacecraft on unperturbed heliocentric orbits allow for highly precise observations of small spatial changes in the gravitational field, especially those affecting the gravity gradient tensor (GGT). The resulting high sensitivity may be used to search for new physics that could manifest itself via deviations from general relativistic behavior yielding a non-vanishing trace of the GGT. We study the feasibility of recovering the trace[GTT] with the sensitivity of ${\cal O}(10^{-24}~{\rm s}^{-2})$ -- the level where some of the recently proposed cosmological models may have observable effects in the solar system. Specifically, we consider how a set of local measurements provided by precision laser ranging (to measure the inter-satellite ranges) and atom-wave interferometry (to correct for any local non-gravitational disturbances) can be used for that purpose. We report on a preliminary study of such an experiment and on the precision that may be reached in measuring the trace[GGT], with the assumption of drag-compensated spacecraft by atom interferometer measurements. For that, we study the dynamical behavior of a tetrahedral formation established by four spacecraft placed on nearby elliptical orbits around the Sun. We develop analytical models for the relevant observables and study the conditions for setting up an optimal tetrahedral configuration. We formulate the observational equations to measure the trace[GTT] relying only on the observables that are available within the formation, such as those based on the laser ranging and the Sagnac interferometry. We demonstrate that Sagnac observable is a mission enabling capability that allows to measure the angular frequency of the tetrahedral rotation with respect to an inertial reference frame with an accuracy that is much higher than that available from any other modern navigational techniques. We show that the quality of the science measurements is affected by the tetrahedron evolution, as its orientation and the shape change while the spacecraft follow their orbits. We present the preliminary mission and instrument requirements needed to measure the trace[GTT] to the required accuracy and thus demonstrate the feasibility of satisfying the stated science objective.
DOI: 10.48577/jpl.bhpou8
title: ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP): Molecular jets and Episodic Accretion in Protostars

description: Protostellar outflows and jets are almost ubiquitous characteristics during the mass accretion phase, and encode the history of stellar accretion, complex-organic molecule (COM) formation, and planet formation. Episodic jets are likely connected to episodic accretion through the disk. Despite the importance, studies on episodic accretion and ejection links have not been done yet in a systematic fashion using high sensitivity and high resolution observations. To explore episodic accretion mechanisms and the chronologies of episodic events, we investigated 39 fields containing protostars with ALMA observations of CO, SiO, and 1.3mm continuum emission. We detected SiO emission in 19 fields, where 17 sources are driving molecular jets. Jet velocities, mass-loss rates, mass-accretion rates, and periods of accretion events appear to have some dependence on the driving forces of the jet (e.g., bolometric luminosity, envelope mass). Next, velocities and mass-loss rates appear to be somewhat correlated with the surrounding envelope mass, suggesting that the presence of high mass around protostars increases the ejection-accretion activity. We determine mean periods of ejection events of 20−175 years for our sample, which could be associated with perturbation zones of ∼ 2−25 au extent around the protostars. Also, mean ejection periods show an apparent anti-correlation with the envelope mass, where high-accretion rates may trigger more frequent ejection events. The observed periods of outburst/ejection are much shorter than the freeze-out time scale of the simplest COMs like CH3OH, suggesting that episodic events could affect the ice-gas balance inside and around the snowline.
DOI: 10.48577/jpl.svwfiq
title: Classifying turbulence regimes in the Martian atmosphere at Jezero Crater, Mars

description: Atmospheric turbulence is defined by irregular fluctuations that develop in most flows, from small-scale near-surface breezes to planetary-scale circulation patterns. Its properties influence the dynamics of flight, design of structures, aeolian interactions between the atmosphere and surface, and the modeling of atmospheric processes. It has been studied most precisely on Earth, leading to models tailored accordingly to terrestrial conditions. Wind speed data collected by Perseverance’s Mars Environmental Dynamics Analyzer (MEDA) are used to determine the turbulence regime that can be resolved by the current equipment on Mars. We use a methodology based on universal spectral scaling, which allows estimates of the threshold scales that separate the energetic, inertial, and molecular dissipation regimes. Results indicate that the MEDA wind measurements on Mars can resolve turbulence scales that span the energetic regime and approach the inertial regime. Although the large-scale end of the inertial regime can be resolved, a 2 Hz sampling frequency, thus far the fastest sampling rate for direct wind sensor measurements on Mars, is not sufficient for covering the entire inertial subrange and resolving its smallest scales. The scales found with this method complement and are consistent with those estimated independently from stagnation pressure measurements, may explain the smallest size observed thus far for dust devils, and may contribute to why multiple reports have not found a consistent Kolmogorov-like spectral regime on Mars. One-Sentence Summary: Wind speed measurements made in Jezero crater resolve the bounds for the turbulence scales on both sides of the inertial subrange. These bounds set constraints on the sizes for coherent structures before they get dissipated by turbulence.
DOI: 10.48577/jpl.niln0c
title: Atmospheric Science Questions for a Uranian Probe

description: Overall, there is currently a great deal of community support for the UOP, highlighted by the number of recently-developed white papers, meeting abstracts, and peer-reviewed works outlining the benefits and possible mechanics of such a mission. Uranus occupies a unique parameter space; it is an extreme laboratory for atmospheric, magnetic, and space physics unique within our Solar System. Exploring not only the atmosphere with \textit{in situ} measurements but long-term remote-sensing observations over a variety of viewing geometries and at spectral and spatial resolutions wholly unobtainable from ground-based observatories, will revolutionize our understanding of Ice Giants, Gas Giants, the formation and evolution of our Solar System, and that of exoplanetary systems beyond.
DOI: 10.48577/jpl.rr77em
title: Micro-thruster ACS Architecture for Precision Pointing of 6-meter Exo-Earth Imaging Space Telescope

description: The ambitious science goals of the Astro2020 Decadal Survey to conduct direct imagery and spectroscopy of Earth-like exo-planets will dictate a stringent pointing stability requirement for the Habitable Worlds Observatory (HWO). Sufficient starlight suppression is achieved through high-contrast coronagraphy, which drives HWO to reach an order-of-magnitude improvement in pointing stability over state-of-the-art precision pointing architectures based on reaction wheels paired with vibration isolation systems. Since further improvement in observatory stability is fundamentally limited by wheel-induced vibrational disturbances, one proposed solution is to remove the wheels in favor of a “thrusters-only” ACS approach that utilizes conventional hydrazine thrusters for maneuvers and micro-thrusters for precision pointing. This thrusters-only ACS approach was baselined by JPL for the 4-meter Habitable Exoplanet Observatory (HabEx) Astro2020 mission concept study. HabEx examined the feasibility of using the Busek Colloid Micro-Newton Thruster (CMNT), an electrospray micro-thruster successfully flight-demonstrated on LISA Pathfinder in 2016, to enable a precision pointing L2 Great Observatory. Following Astro2020 recommendations for a 6 meter “IR/O/UV telescope optimized for observing habitable exo-planets and general astrophysics,” JPL has developed a scaled-up “6 Meter Space Telescope” (6MST) design concept based on HabEx. Ongoing JPL research is examining the CMNT when paired with the 6MST to design and evaluate a realistic thrusters-only ACS architecture for HWO based on existing technology. As with HabEx, current ACS design work is focused on developing a time and fuel-efficient ACS architecture, given conservative estimates of the environmental torque disturbance from solar radiation pressure and the maximum thrust capability of the CMNT micro-thrusters. Here we summarize the latest CMNT performance capability, the 6MST observatory reference design, and the proposed thrusters-only ACS architecture and evaluation approach.
DOI: 10.48577/jpl.xokwqs
title: Probing THz Intersubband Absoprtion using Johnson Noise Thermometry

description: We investigate the THz intersubband absorption behavior of a single 40-nm wide GaAs/AlGaAs square quantum well (QW) using Johnson noise thermometry. In our measurements, the Johnson noise associated with intersubband absorption is measured from the in-plane conduction channel of the QW while its intersubband absorption behavior is being tuned through the independent control of the charge density and the perpendicular DC electric field. Our measurements enable the study of intersubband absorption of a small (~20,000 and potentially fewer) number of electrons in a single mesoscopic device, as well as direct measurement of the electron heating from intersubband absorption. By measuring the Johnson noise response to monochromatic THz radiation at 2.52 THz and 4.25 THz at 20 K as a function of the DC electric field over a wide range of charge density, we show that the observed Johnson noise behavior correlates well with the expected intersubband absorption of the 40-nm QW. To explain the absorption features of the experimental results, we model the data by calculating the THz coupling efficiency based on the impedance model for intersubband absorption, which qualitatively reproduces the observed Johnson noise behavior well. Based on the temperature calibration of the Johnson noise measured at 2.52 THz, we deduce an increase in the electron temperature ΔT_e of ~ 35 K when the maximum absorption of THz power occurs in the device.
DOI: 10.48577/jpl.69js3a
title: Near-Earth Object Observations using Synthetic Tracking

description: Synthetic tracking (ST) has emerged as a potent technique for observing fast- moving near-Earth objects (NEOs), offering enhanced detection sensitivity and astrometric accuracy by avoiding trailing loss. This approach also empowers small telescopes to use prolonged integration times to achieve high sensitivity for NEO survey and follow-up observations. In this study, we present the outcomes of ST observations conducted with Pomona College’s 1 m telescope at the Table Mountain Facility and JPL’s robotic telescopes at the Sierra Remote Observa- tory. The results showcase astrometric accuracy statistics comparable to stellar astrometry, irrespective of an object’s rate of motion, and the capability to detect faint asteroids beyond 20.5th magnitude using 11-inch telescopes. Furthermore, we detail the technical aspects of data processing, including the correction of differential chromatic refraction in the atmosphere and accurate timing for image stacking, which contribute to achieving precise astrometry. We also provide compelling examples that showcase the robustness of ST even when asteroids closely approach stars or bright satellites cause disturbances. Moreover, we illustrate the proficiency of ST in recovering NEO candidates with highly uncertain ephemerides. As a glimpse of the potential of NEO surveys utilizing small robotic telescopes with ST, we present significant statistics from our NEO survey conducted for testing purposes. These findings underscore the promise and effectiveness of ST as a powerful tool for observing fast-moving NEOs, offering valuable insights into their trajectories and characteristics. Overall, the adoption of ST stands to revolutionize fast-moving NEO observations for planetary defense and studying these celestial bodies.
DOI: 10.48577/jpl.6hvrgs
title: Modelling wildland fire burn severity in California using a spatial super learner approach

description: Given the increasing prevalence of wildland fires in the Western US, there is a critical need to develop tools to understand and accurately predict burn severity. We develop a novel machine learning model to predict post-fire burn severity using pre-fire remotely sensed data. Hydrological, ecological, and topographical variables collected from four regions of California — the site of the Kincade fire (2019), the CZU Lightning Complex fire (2020), theWindy fire (2021), and the KNP Fire (2021) — are used as predictors of the differenced normalized burn ratio. We hypothesize that a Super Learner (SL) algorithm that accounts for spatial autocorrelation using Vecchia’s Gaussian approximation will accurately model burn severity. In all combinations of test and training sets explored, the results of our model showed the SL algorithm outperformed standard linear regression methods. After fitting and verifying the performance of the SL model, use interpretable machine learning tools to determine the main drivers of severe burn damage, including greenness, elevation and fire weather variables. These findings provide actionable insights that enable communities to strategize interventions, such as early fire detection systems, pre-fire season vegetation clearing activities, and resource allocation during emergency responses. When implemented, this model has the potential to minimize the loss of human life, property, resources, and ecosystems in California.
DOI: 10.34740/kaggle/ds/4372730
title: Distributed IMU Sensors on an Alpine Ski
DOI: 10.6084/m9.figshare.25137092
title: 02.02.23_datactarvadherencerepository.xlsx

description: Data from 2022 study in ART clinic.
DOI: 10.6084/m9.figshare.25137092.v1
title: 02.02.23_datactarvadherencerepository.xlsx

description: Data from 2022 study in ART clinic.
DOI: 10.6073/pasta/7f464e52068adcabd3eb3a28f6252511
title: WAT01 Konza Prairie long-term irrigation transect study

description: In 1991, an irrigation transect experiment was established near the Konza Prairie HQ to assess the effects of supplemental water on ecological processes in tallgrass prairie. The site is burned annually in the spring. The transect spans upland, hillside and lowland topographic positions with irrigation and sampling points (12) located at 10 m intervals. Adjacent control transects are marked on both sides of the irrigation transect. Irrigation is scheduled according to estimates of actual evapotranspiration and measures of plant water status. In 1992, an additional 4 irrigation sprinklers were added to the transect (2 at each end). In 1993, a second line of sprinklers and control plots was added (#16-31). At the time of peak aboveground biomass (late August to October), six 0.1 m2 quadrats are harvested at each of the 30 sites (no #9 due to rock outcrop) for the irrigated and control/non-irrigated lines. Biomass is separated into live grass, forb and woody. As of 2006, c.dead is no longer separated from live grass. 
 
 
 Vegetative species composition was initially measured in 1991 at each site, and continues to be measured at midseason by using a modified Daubenmire canopy coverage technique in a 10 m2 circular plot. At approximately 10 day intervals, predawn and midday plant water potentials are measured in Andropogon gerardii at each site in both irrigated and control transects. Since 1992, reproductive effort of the dominant grasses Andropogon gerardii (ANGE), Sorghastrum nutans (SONU), Schizachyrium scoparius (ANSC) has been assessed in irrigated and control transects by measuring heights (n=9) and densities (n=4) of flowering stalks. In 1993, soil moisture measurements at 15 and 30 cm depths were begun with a Time Domain Reflectometry system. Data set also includes measured natural precipitation and supplemental water added to the site. 
 
 
 Full data used in the Broderick et al. (2022) paper, "Climate legacies determine grassland responses to future rainfall regimes", can be found at the link: http://lter.konza.ksu.edu/content/wat02-climate-legacies-determine-grassland-responses-future-rainfall-regimes
DOI: 10.34740/kaggle/dsv/7541885
title: ICT Operations Survey
DOI: 10.15139/s3/sybhn8
title: Stoichiometry For Entry and Binding Properties of the Env Protein of R5 T Cell-Tropic HIV-1 and Its Evolutionary Variant of Macrophage-Tropic HIV-1

description: This is the data for the Stoichiometry For Entry and Binding Properties of the Env Protein of R5 T Cell-Tropic HIV-1 and Its Evolutionary Variant of Macrophage-Tropic HIV-1 paper submitted to mbio.
DOI: 10.34740/kaggle/dsv/7541969
title: Daily Public Opinion on Israel-Palestine War
DOI: 10.34740/kaggle/dsv/7541976
title: Public Opinion on Climate Change (Updated Daily)
DOI: 10.5281/zenodo.8272854
title: KCNA2 IgG Autoimmunity In Neuropsychiatric Diseases

description: One patient of the cohort  (#25) received a temporal lobe biopsy to rule out a malignant disease. Histological and immunohistochemical images of diagnostic sections are shown. From these images regions of interest are shown in Figure 2.
DOI: 10.5281/zenodo.8272855
title: KCNA2 IgG Autoimmunity In Neuropsychiatric Diseases

description: One patient of the cohort  (#25) received a temporal lobe biopsy to rule out a malignant disease. Histological and immunohistochemical images of diagnostic sections are shown. From these images regions of interest are shown in Figure 2.