Miracle-dz/UniFAR-FTUs huggingface dataset:
Survival probability of atmospheric new particles: closure between theory and measurements from 1.4 to 100 nm

The survival probability of freshly nucleated particles governs the influences of new particle formation (NPF) on atmospheric environments and the climate. It characterizes the probability of a particle to avoid being scavenged by the 15 coagulation with pre-existing particles and other scavenging processes before the particle successfully grows up to a certain diameter. Despite its importance, measuring the survival probability has been challenging, which limits the knowledge of particle survival in the atmosphere and results in large uncertainties in predicting the influences of NPF. Here we report the proper methods to retrieve particle survival probability of the measured aerosol size distributions at different particle sizes. Using diverse aerosol size distributions from urban Beijing, the Finnish boreal forest, a chamber experiment, and aerosol 20 kinetic simulations, we demonstrate that each method is valid for a different type of aerosol size distributions whereas misapplying the conventional methods to banana-type NPF events may underestimate the survival probability. Using these methods, we investigate the consistency between the measured survival probability of new particles and the theoretical survival probability against coagulation scavenging predicted using the measured growth rate and coagulation sink. With case-by-case and time- and size-resolved analysis of long-term measurement data from urban Beijing, we find that although both the 25 measured and theoretical survival probabilities are sensitive to uncertainties and variations, they are, on average, consistent with each other for new particles growing from 1.4 nm (the cluster size) to 100 nm.
Using Spatial Curvature with H ii Galaxies and Cosmic Chronometers to Explore the Tension in H0

We present a model-independent measurement of spatial curvature Ωk in the Friedmann–Lemaître–Robertson–Walker universe, based on observations of the Hubble parameter H(z) using cosmic chronometers, and a Gaussian process (GP) reconstruction of the H ii galaxy Hubble diagram. We show that the imposition of spatial flatness (i.e., Ωk = 0) easily distinguishes between the Hubble constant measured with Planck and that based on the local distance ladder. We find an optimized curvature parameter when using the former (i.e., ), and for the latter ( ). The quoted uncertainties are extracted by Monte Carlo sampling, taking into consideration the covariances between the function and its derivative reconstructed by GP. These data therefore reveal that the condition of spatial flatness favors the Planck measurement, while ruling out the locally inferred Hubble constant as a true measure of the large-scale cosmic expansion rate at a confidence level of ∼3σ.
Constraining Metallicity-dependent Mixing and Extra Mixing Using [C/N] in Alpha-rich Field Giants

Internal mixing on the giant branch is an important process which affects the evolution of stars and the chemical evolution of the galaxy. While several mechanisms have been proposed to explain this mixing, better empirical constraints are necessary. Here, we use [C/N] abundances in 26,097 evolved stars from the SDSS-IV/APOGEE-2 Data Release 14 to trace mixing and extra mixing in old field giants with −1.7 < [Fe/H] < 0.1. We show that the APOGEE [C/N] ratios before any dredge-up occurs are metallicity dependent, but that the change in [C/N] at the first dredge-up is metallicity independent for stars above [Fe/H] ∼ −1. We identify the position of the red giant branch (RGB) bump as a function of metallicity, note that a metallicity-dependent extra mixing episode takes place for low-metallicity stars ([Fe/H] < −0.4) 0.14 dex in log g above the bump, and confirm that this extra mixing is stronger at low metallicity, reaching Δ[C/N] = 0.58 dex at [Fe/H] = −1.4. We show evidence for further extra mixing on the upper giant branch, well above the bump, among the stars with [Fe/H] < −1.0. This upper giant branch mixing is stronger in the more metal-poor stars, reaching 0.38 dex in [C/N] for each 1.0 dex in log g. The APOGEE [C/N] ratios for red clump (RC) stars are significantly higher than for stars at the tip of the RGB, suggesting additional mixing processes occur during the helium flash or that unknown abundance zero points for C and N may exist among the RC sample. Finally, because of extra mixing, we note that current empirical calibrations between [C/N] ratios and ages cannot be naively extrapolated for use in low-metallicity stars specifically for those above the bump in the luminosity function.
EFFECTIVENESS OF DRIVER MONITORING SYSTEMS

Active driving assistance (ADA) systems are becoming increasingly popular and sometimes marketed under confusing names leading some consumers to overestimate system capabilities. Currently available ADA systems are classified by SAE International® 1 as a Level 2 partial driving automation feature, meaning that constant driver supervision is required. To mitigate misuse of these systems, a driver monitoring component is integrated. Within this study, driver monitoring systems are classified as either direct or indirect . Direct systems integrate a driver-facing camera to detect driver distraction or disengagement. In contrast, indirect systems only utilize steering wheel input for the detection of driver distraction or disengagement. To evaluate the performance of driver monitoring systems with respect to system type, four popular vehicles equipped with an ADA system were evaluated by simulating driver disengagement (common behaviors such as texting, reading, watching videos, or general manipulation of a mobile device) in a real-world highway environment.
Fluorescence characteristics, absorption properties, and radiative effects of water-soluble organic carbon in seasonal snow across northeastern China

Abstract. Water-soluble organic carbon (WSOC) in the cryosphere can significantly influence the global carbon cycle and radiation budget. However, WSOC in the snowpack has received little scientific attention to date. This study reports the fluorescence characteristics, absorption properties, and radiative effects of WSOC based on 34 snow samples collected from sites in northeastern China. A significant degree of regional WSOC variability is found, with concentrations ranging from 0.5±0.2 to 5.7±3.7 µg g−1 (average concentration: 3.6±3.2 µg g−1). The three principal fluorescent components of WSOC are identified as (1) the high-oxygenated humic-like substances (HULIS-1) of terrestrial origin, (2) the low-oxygenated humic-like substances (HULIS-2) of mixed origin, and (3) the protein-like substances (PRLIS) derived from autochthonous microbial activity. In southeastern Inner Mongolia (SEIM), a region dominated by desert and exposed soils, the WSOC exhibits the highest humification index (HIX) but the lowest fluorescence (FI) and biological (BIX) indices; the fluorescence signal is mainly attributed to HULIS-1 and thus implicates soil as the primary source. By contrast, the HIX (FI and BIX) value is the lowest (highest), and the percentage of PRLIS is the highest in the remote area of northeastern Inner Mongolia (NEIM), suggesting a primarily biological source. For south and north of northeastern China (SNC and NNC), both of which are characterized by intensive agriculture and industrial activity, the fluorescence signal is dominated by HULIS-2, and the HIX, FI, and BIX values are all moderate, indicating the mixed origins for WSOC (anthropogenic activity, microbial activity, and soil). We also observe that, throughout northeastern China, the light absorption of WSOC is dominated by HULIS-1, followed by HULIS-2 and PRLIS. The contribution of WSOC to albedo reduction (average concentration: 3.6 µg g−1) in the ultraviolet–visible (UV–Vis) band is approximately half that of black carbon (BC average concentration: 0.6 µg g−1). Radiative forcing is 3.8 (0.8) W m−2 in old (fresh) snow, equating to 19 % (17 %) of the radiative forcing of BC. These results indicate that WSOC has a profound impact on snow albedo and the solar radiation balance.
Review of “Conditions favorable for secondary ice production in Arctic mixed-phase clouds” by Pasquier et al.

The paper presents an important in-situ observation of secondary ice production in Arctic clouds from a tethered balloon with the help of a high-resolution imaging probe HOLIMO. The HOLIMO provided photographic quality images of cloud particles, which, in the majority of cases, allowed for unambiguous identification of particles habit and their phase. The in-situ observations were complemented by remote sensing observations, which allowed for accurate positioning of the HOLIMO measurements with respect to cloud boundaries. Ground based measurements of INPs provided a significant contribution to the value and quality of the col-lected data set. One of the major outcomes of this study is lowering the threshold concentration of ice particles separating primary and secondary ice production. This is different from the past observations when SIP was identified as an explosive increase in the number concentration of ice particles exceeding hundreds and thousands per liter. In the present study, the threshold concentration was reduced to the order of 0.1-10 per liter. The paper provides an important contribution to the understanding of the role of SIP in ice formation and, undoubtedly, it should be published in ACP. The paper is well written, and I do not have any significant comments on this work. There are a few minor comments which are worth addressing prior to publication. Recommendation: paper
Effects of a soft x-ray background on structure formation at high redshift

We use three dimensional hydrodynamic simulations to investigate the effects of a soft X-ray background, that could have been produced by an early generation of mini-quasars, on the subsequent cooling and collapse of high redshift pregalactic clouds. The simulations use an Eulerian adaptive mesh refinement technique with initial conditions drawn from a flat �dominated cold dark matter model cosmology to follow the nonequilibrium chemistry of nine chemical species in the presence of both a soft ultraviolet Lyman-Werner H2 photodissociating flux of strength FLW = 10 21 erg s 1 cm 2 Hz 1 and soft X-ray background extending to 7.2 keV including the ionization and heating effects due to secondary electrons. Although we vary the normalization of the X-ray background by two orders of magnitude, the positive feedback effect of the X-rays on cooling and collapse of the pregalactic cloud expected due to the increased electron fraction is quite mild, only we akly affecting the mass threshold for collapse and the fraction of gas within the cloud that is able to cool, condense and become available for star formation. Inside most of the cloud we find that H 2 is in photodissociation equilibrium with the soft UV flux. The net buildup o f the electron density needed to enhance H2 formation occurs too slowly compared to the H2 photodissociation and dynamical timescales within the cloud to overcome the negative impact of the soft UV photodissociating flux on cloud collapse. However, we find that even in the most ex treme cases the first objects to form do rely on molecular hydrogen as coolant and stress that our results do not justify the neglect of these objects in models of galaxy formation. Outside the cloud we find the dominant effect of a sufficiently strong X-ray background is to heat and partially ionize the inter-galactic medium, in qualitative agreement with previous studies.
Emission factors and evolution of SO2 measured from biomass burning in wildfires and agricultural fires

Abstract. Fires emit sufficient sulfur to affect local and regional air quality and climate. This study analyzes SO2 emission factors and variability in smoke plumes from US wildfires and agricultural fires, as well as their relationship to sulfate and hydroxymethanesulfonate (HMS) formation. Observed SO2 emission factors for various fuel types show good agreement with the latest reviews of biomass burning emission factors, producing an emission factor range of 0.47–1.2 g SO2 kg−1 C. These emission factors vary with geographic location in a way that suggests that deposition of coal burning emissions and application of sulfur-containing fertilizers likely play a role in the larger observed values, which are primarily associated with agricultural burning. A 0-D box model generally reproduces the observed trends of SO2 and total sulfate (inorganic + organic) in aging wildfire plumes. In many cases, modeled HMS is consistent with the observed organosulfur concentrations. However, a comparison of observed organosulfur and modeled HMS suggests that multiple organosulfur compounds are likely responsible for the observations but that the chemistry of these compounds yields similar production and loss rates as that of HMS, resulting in good agreement with the modeled results. We provide suggestions for constraining the organosulfur compounds observed during these flights, and we show that the chemistry of HMS can allow organosulfur to act as an S(IV) reservoir under conditions of pH > 6 and liquid water content >10−7 g sm−3. This can facilitate long-range transport of sulfur emissions, resulting in increased SO2 and eventually sulfate in transported smoke.
Loss and Gain of Regularity in a Lubrication Equation for Thin Viscous Films

A. L. BERTOZZI Loss and gain of regularity in a lubrication equation for thin Viscous ﬁlms This drticie is dedicated to my collaborators. ’ Michael Brenner, Todd Duporit, Leo Kdddrioﬁf drid Mary Pugh. Fourth order degenerate diffusion equations arise in the study of in the motion of thin ﬁlms and and membranes of viscous liquid in which the surface tension of the liquid/ air interface determines the evolution. These equations are derived via a lubrication approximation in which the ﬂuid velocity is depth averaged in the direction transverse to the film [16, 14]. One typically obtains an evolution equation for the thickness h of the film of the form (1) ht + v - (h”’VAh) = 0, :1: e Rd h(:1;,0) : h0(:1:) n g 0 Where n depends on the geometry of the problem and any boundary conditions relevant for the ﬂuid. Examples include a thin neck in the Hele—ShaW cell for which n = 1 and d = 1 [11] and a thin film on a solid surface with no slip on the fluid/ solid interface for which n = 3 and d = 2 [14]. The problem that I consider here is the evolution from strictly positive initial data. For a discussion of evolution from nonnegative initial data see [7, 2, 3]. Topological transitions in the thin film have a simple mathematical interpreta- tion in the context of the lubrication approximation. They correspond to finite time singularities in the PDE of the form (2) /i(:1:,t) —g 0 as t—g tc. The recent Work [8] is the first comprehensive study of the effect of the nonlinearity n on finite time singularities of the form (2) for (1) in one dimension. One feature of this Work Was the observation of various ‘bifurcations’ or transitions in the structure of the solutions at many critical values of n. This is in sharp contrast to the analogous second order ‘porous medium’ equation for which singularities of the form (2) are not possible due to a maximum principle [15]. Furthermore, equation (1) is known to have transitions at critical values of n for some known exact solutions. For example, ‘source type’ solutions with compact support only exist for n l 3 and have a transition in their behavior at the edge of the support at n = 3 / 2 The lack of source type solutions for the case n = 3 is particularly relevant to the problem of a spreading drop on a solid surface [10]. Furthermore, traveling Wave solutions have critical transitions at n : 3/ 2, 2, and 3 Recent
On the calculation of Lorenz numbers for complex thermoelectric materials

A first-principles informed approach to the calculation of Lorenz numbers for complex thermoelectric materials is presented and discussed. Example calculations illustrate the importance of using accurate band structures and energy-dependent scattering times. Results obtained by assuming that the scattering rate follows the density-of-states show that in the non-degenerate limit, Lorenz numbers below the commonly assumed lower limit of 2(kB/q)2 can occur. The physical cause of low Lorenz numbers is explained by the shape of the transport distribution. The numerical and physical issues that need to be addressed in order to produce accurate calculations of the Lorenz number are identified. The results of this study provide a general method that should contribute to the interpretation of measurements of total thermal conductivity and to the search for materials with low Lorenz numbers, which may provide improved thermoelectric figures of merit, zT.
Cooling of hypernuclear compact stars: Hartree–Fock models and high-density pairing

The thermal evolution of hypernuclear compact stars is studied for stellar models constructed on the basis of covariant density functional theory in Hartree and Hartree–Fock approximation. Parametrizations of both types are consistent with the astrophysical mass constraints on compact stars and available hypernuclear data. We discuss the differences of these density functionals and highlight the effects they have on the composition and on the cooling of hypernuclear stars. It is shown that hypernuclear stars computed with density functional models that have a low symmetry energy slope, L, are fairly consistent with the cooling data of observed compact stars. The class of stellar models based on larger L values gives rise to the direct Urca process at low densities, which leads to significantly faster cooling. We conjecture high-density pairing for protons and Λ’s in the P-wave channel and provide simple scaling arguments to obtain these gaps. As a consequence the most massive stellar models with masses 1.8 ≤ M/M⊙ ≤ 2 experience slower cooling by hyperonic dUrca processes which involve Λ’s and protons.
Precision computation of hybrid static potentials in SU(3) lattice gauge theory

We perform a precision computation of hybrid static potentials with quantum numbers $\Lambda_\eta^\epsilon = \Sigma_g^-,\Sigma_u^+,\Sigma_u^-,\Pi_g,\Pi_u,\Delta_g,\Delta_u$ using SU(3) lattice gauge theory. The resulting potentials are used to estimate masses of heavy $\bar{c} c$ and $\bar{b} b$ hybrid mesons in the Born-Oppenheimer approximation. Part of the lattice gauge theory computation, which we discuss in detail, is an extensive optimization of hybrid static potential creation operators. The resulting optimized operators are expected to be essential for future projects concerning the computation of 3-point functions as e.g. needed to study spin corrections, decays or the gluon distribution of heavy hybrid mesons.
/spl Hscr//sub /spl infin// design of switching surfaces for sliding modes control with non-matching disturbances

A guaranteed cost /spl Hscr//sub /spl infin//-norm design is presented for sliding surfaces in variable structure controllers. This procedure is suitable for approximate rejection of non-matching disturbances. Both unstructured signal disturbances and structured convex-bounded model uncertainties are considered. A state-space convex optimization approach, via LMIs, is employed in the surface design.
Initial Data for the Two-Body Problem of General Relativity

The numerical study of Einstein’s equations is of considerable interest for both astrophysical and purely theoretical reasons as it provides the only known avenue for the study of strong field, highly relativistic gravitational interactions. Of particular interest is the geometrodynamic twobody problem since the collision of two black holes is believed to be a strong source of gravitational radiation. Before studying the dynamics of such collisions, one must first obtain complete initialdata sets which represent two black holes in some initial configuration including non-vanishing linear and angular momenta for each hole. A formalism for constructing such initial-data sets is reviewed. Based on this formalism, computational techniques are developed which allow for the complete specification of initial data describing both one and two black holes with individually specifiable linear and angular momenta. In the case of two black holes, the initial data is constructed in two separate, base coordinate systems. Bispherical coordinates are used to construct very accurate initial-data sets. Cadež coordinates are also used because this coordinate system is most appropriate for future work on the evolution of the initial data. A method for locating apparent horizons in the initial-data sets is developed by posing the apparent-horizon equation as a boundary-value problem. This method is applied to the single-hole, initial-data sets leading to a new understanding of the physical content of these initial hypersurfaces. The physical content of the two-hole, initial-data sets is also explored.
C-GOALS

We analyze Chandra X-ray observatory data for a sample of 63 luminous infrared galaxies (LIRGs), sampling the lower-infrared luminosity range of the Great Observatories All-Sky LIRG survey (GOALS), which includes the most luminous infrared selected galaxies in the local Universe. X-rays are detected for 84 individual galaxies within the 63 systems, for which arcsecond resolution X-ray images, fluxes, infrared and X-ray luminosities, spectra and radial profiles are presented. Using X-ray and mid-infrared (MIR) selection criteria, we find AGN in (31 ± 5)% of the galaxy sample, compared to the (38 ± 6)% previously found for GOALS galaxies with higher infrared luminosities (C-GOALS I). Using MIR data, we find that (59 ± 9)% of the X-ray selected AGN in the full C-GOALS sample do not contribute significantly to the bolometric luminosity of the host galaxy. Dual AGN are detected in two systems, implying a dual AGN fraction in systems that contain at least one AGN of (29 ± 14)%, compared to the (11 ± 10)% found for the C-GOALS I sample. Through analysis of radial profiles, we derive that most sources, and almost all AGN, in the sample are compact, with half of the soft X-ray emission generated within the inner ∼1 kpc. For most galaxies, the soft X-ray sizes of the sources are comparable to those of the MIR emission. We also find that the hard X-ray faintness previously reported for the bright C-GOALS I sources is also observed in the brightest LIRGs within the sample, with LFIR > 8 × 1010 L⊙.