Miracle-dz/UniFAR-FTUs huggingface dataset:
How tough is tuff in the event of fire

Tuff has been extensively used as a building material in volcanically and tectonically active areas over many centuries, despite its inherent low strength. A common and unfortunate secondary hazard accompanying both major volcanic eruptions and tectonic earthquakes is the initiation of catastrophic fires. Here we report new experimental results on the influence of high temperatures on the strength of three tuffs that are commonly used for building in the Neapolitan region of Italy. Our results show that a reduction in strength was only observed for one tuff; the other two were unaffected by high temperatures. The cause of this strength discrepancy was found to be a product of the initial mineralogical composition, or more specifically, the presence of thermally unstable zeolites within the initial rock matrix. The implications of these data are that, in the event of fire, only the stability of buildings or structures built from tuff containing thermally unstable zeolites will be reduced. Unfortunately, this includes the most widespread dimension stone in Neapolitan architecture. We recommend that this knowledge should be considered during fire hazard mitigation in the Neapolitan area and that other tuffs used in construction worldwide should be tested in a similar way to assess their fire resistance.
A Model of Pollen Source Area for an Entire Lake Surface

Abstract A model of pollen deposition on the surface of an entire basin is developed to estimate pollen source area, and results are compared with those for a point at the center of a basin (I. C. Prentice, 1985, Quaternary Research 23, 76-86; 1988, "Vegetation History," (pp. 17-42, Kluwer Academic). This model is more appropriate for approximating the source area of pollen in lake sediment, since mixing in lake water and focusing of sediment redistribute pollen originally deposited over the entire surface. In general, the pollen source radius for the entire basin surface is 10-30% smaller than the source radius for a point at the center; the difference in the source radius is more profound for heavier pollen types such as spruce and sugar maple than for lighter types such as oak and ragweed. The average pollen input to the entire surface is more strongly influenced by nearby pollen sources than pollen deposition at the center. The pollen record from a lake may therefore provide different spatial resolution than the record from a bog of similar radius.
Evaluating shifts in mobility and COVID-19 case rates in U.S. counties: A demonstration of modified treatment policies for causal inference with continuous exposures (preprint)

Previous research has shown mixed evidence on the associations between mobility data and COVID-19 case rates, analysis of which is complicated by differences between places on factors influencing both behavior and health outcomes. We aimed to evaluate the county-level impact of shifting the distribution of mobility on the growth in COVID-19 case rates from June 1 - November 14, 2020. We utilized a modified treatment policy (MTP) approach, which considers the impact of shifting an exposure away from its observed value. The MTP approach facilitates studying the effects of continuous exposures while minimizing parametric modeling assumptions. Ten mobility indices were selected to capture several aspects of behavior expected to influence and be influenced by COVID-19 case rates. The outcome was defined as the number of new cases per 100,000 residents two weeks ahead of each mobility measure. Primary analyses used targeted minimum loss-based estimation (TMLE) with a Super Learner ensemble of machine learning algorithms, considering over 20 potential confounders capturing counties' recent case rates as well as social, economic, health, and demographic variables. For comparison, we also implemented unadjusted analyses. For most weeks considered, unadjusted analyses suggested strong associations between mobility indices and subsequent growth in case rates. However, after confounder adjustment, none of the indices showed consistent associations after hypothetical shifts to reduce mobility. While identifiability concerns limit our ability to make causal claims in this analysis, MTPs are a powerful and underutilized tool for studying the effects of continuous exposures.
Kinematic and dynamic evolution of deep water breaking waves

Experiments were performed to exploit the dispersive properties of unsteady surface waves and to induce breaking by using a modified chirp pulse technique to focus the wave energy at a specific location in the Naval Research Laboratory deep water wave channel. The experiments have resulted in a highly resolved archive of breaking events ranging from wave steepening and incipient breaking to spilling and to plunging. The potential energy density, the crest front steepness, the horizontal asymmetry, and other geometric properties of an incipient breaker vary only within a moderate band about their mean values over the extent of these experiments. Thus the properties of an incipient unsteady breaker are well defined. The application of the phase-time or Hilbert transform method to the data set provides new insights into the local properties of the unsteady wave breaking. Recently, spectral and piecewise-linear algorithms for two-dimensional potential flow were developed and used by Schultz et al. [1994] to compare the onset of breaking for several methods of energy input to the unsteady wave system. The computations show that steep plunging waves occur when energy input rates are large. The various energy input methods exhibit similar breaking trends in the limit as the energy input rate becomes small in that incipient spilling breakers form when the potential energy is approximately 52 to 54% of the energy for the most energetic Stokes wave, with the formation of a singularity immediately before the crest.
Technological Features of Roman Terra Sigillata from Gallic and Italian Centres of Production

Abstract Technological features of sherds of Roman terra sigillata were studied. The sherds analysed represented products of workshops which were most probably located in Gaul, central Italy, north-west Italy and the plain of the river Po. Equivalent firing temperatures were estimated by colour measurement, X-ray diffraction and thermal expansion measurement; in addition, the chemical and morphological features of the red sintered slips were investigated using scanning electron microscopy coupled with energy dispersive X-ray microanalysis. The combined results suggest that, relative to northern Italian products, terra sigillata from Gaul and central Italy was made by potters who were more successful in modifying slip composition and controlling firing temperature to obtain highly sintered slips. Northern Italian potters seem to have worked their clays less successfully and fired them at temperatures which were too low to overcome the limited presence of fluxes in the slip.
On eddy-topographic stress representation

Abstract A parameterization of eddy–topographic stress interactions has been proposed previously by Holloway, based on the statistical mechanical equilibria of unforced inviscid models. Tendency toward such equilibria may account for the presence of deep currents observed along oceanic continental margins. The parameterization includes simplifications of the statistical equilibria permitting a local implementation of these tendencies into coarse-resolution ocean models. The approximations involved in this parameterization are examined in simulations with an inviscid quasigeostrophic model with idealized topography representing a continental margin. Time-averaged flows are in qualitative agreement with the suggested pattern and are dominated by a large-scale cyclonic circulation along the basin margin. Results show that the parameterized equilibria can significantly overestimate the along-isobath transport due to neglect of the relative vorticity component of the potential vorticity.
Isotopic, geochemical, and temporal characterization of Proterozoic basement rocks in the Quitovac region, northwestern Sonora, Mexico: Implications for the reconstruction of the southwestern margin of Laurentia

A detailed geochemical characterization of 19 representative Proterozoic basement rocks in the Quitovac region in northwestern Sonora, Mexico, has identified two distinct Paleoproterozoic basement blocks that coincide spatially with the previously proposed Caborca and “North America” blocks. New U-Pb zircon geochronology revises their age ranges, the Caborca (1.78–1.69 Ga) and “North America” (1.71–1.66 Ga) blocks at Quitovac, and precludes a simple age differentiation between them. In addition, Grenvillian-age granitoids (ca. 1.1 Ga), spatially associated with the Caborca block have been identified at Quitovac. Nd isotopes and major- and trace- element geochemistry support the distinction of these Paleoproterozoic blocks. Granitoids of the “North America” block are characterized by depleted eNd values (3.4–3.9) and younger Nd model ages (1800–1740 Ma) and have lower K 2 O, Y, Rb, Ba, Th, REE, and Fe/Mg values than coeval rocks of the Caborca block. The Caborca block granitoids are likewise characterized by slightly less depleted eNd (0.6–2.6) and older Nd model ages (2070–1880 Ma). Despite the subtle differences, granitoids from both the Caborca and “North America” blocks exhibit island arc-like affinities. We propose that the Proterozoic basement rocks from the Quitovac region are an extension of the Proterozoic crustal provinces in the southwestern United States. Specifically, rocks of the Caborca block exhibit an affinity to rocks of either the Yavapai province or the Mojave– Yavapai transition zone, whereas rocks of the “North America” block have signatures similar to those of the Mazatzal province or possibly the Yavapai province of Arizona. The new isotopic ages and geochemical data do not support the existence of the Late Jurassic Mojave–Sonora megashear at Quitovac, as originally proposed. However, the Quitovac region accounts only for a small fraction of the Proterozoic basement in Sonora, so these findings do not eliminate the possibility of a megashear elsewhere in northern Sonora. Our new data create the possibility of alternative hypotheses for the distribution of Paleoproterozoic crustal provinces in southwestern North America that affect reconstructions of the original southwestern margin of Laurentia, and reduce uncertainties in the configuration, timing, and existence of the Proterozoic supercontinent, Rodinia.
Similarity 1 Similarity

Similarity 2 Introduction Human assessments of similarity are fundamental to cognition because similarities in the world are revealing. The world is an orderly enough place that similar objects and events tend to behave similarly. This fact of the world is not just a fortunate coincidence. It is because objects are similar that they will tend to behave similarly in most respects. It is because crocodiles and alligators are similar in their external form, internal biology, behavior, diet, and customary environment that one can often successfully generalize from what one knows of one to the other. As Quine (1969) observed, " Similarity, is fundamental for learning, knowledge and thought, for only our sense of similarity allows us to order things into kinds so that these can function as stimulus meanings. Reasonable expectation depends on the similarity of circumstances and on our tendency to expect that similar causes will have similar effects (p. 114). " Similarity thus plays a crucial role in making predictions because similar things usually behave similarly. From this perspective, psychological assessments of similarity are valuable to the extent that they provide grounds for predicting as many important aspects of our world as Appreciating the similarity between crocodiles and alligators is helpful because information learned about one is generally true of the other. If we learned an arbitrary fact about crocodiles, such as they are very sensitive to the cold, then we would probably be safe in inferring that this fact is also true of alligators. As the similarity between A and B increases, so does the probability of correctly inferring that B has X upon knowing that A has X (Tenenbaum, 1999). This relation assumes that we have no special knowledge related to property X. Empirically, Heit and Rubinstein (1994) have shown that if we do know about the property, then this knowledge, rather than a one-size-fits-all similarity, is used to guide our inferences. For example, if people are asked to make an inference about an anatomical property, then anatomical similarities have more influence than behavioral similarities. Boars are anatomically but not behaviorially similar to pigs, and this difference successfully predicts that people are likely to make anatomical but not behavioral inferences from pigs to boars. The logical extreme of this line of reasoning (Goodman, 1972; Quine, 1977) is that if one has complete knowledge about the reasons why an object has a property, then general similarity is …
Memoirs on Differential Equations and Mathematical Physics

In the present work, the classical nonlinear Kirchhoff string equation is considered. A three-layer symmetrical semi-discrete scheme with respect to the temporal variable is applied for finding an approximate solution to the initial-boundary value problem for this equation, in which the value of the gradient of a non-linear term is taken at the middle point. This approach is essential because the inversion of the linear operator is sufficient for computations of approximate solutions for each temporal step. The variation method is applied to the spatial variable. Differences of the Legendre polynomials are used as coordinate functions. This choice of Legendre polynomials is also important for numerical realization. This way makes it possible to get a system whose structure does not essentially differ from the corresponding system of difference equations allowing us to use the methods developed for solving a system of difference equations. An application of the suggested variational-difference scheme for the numerical treatment of the stated nonlinear problem gives us an opportunity to solve the system of linear equations instead of a nonlinear one. It is proved that a matrix of the system of Galerkin’s linear equations is positively defined and the stability of the factorization method is established. The program of the numerical implementation with the corresponding interface is created based on the suggested algorithm, and numerical computations are carried out for the model problems. 2010 Mathematics Subject Classification. 65F05, 65F50, 65M06, 65M60, 65N12, 65N22, 65Q30.
Directional distribution of the short wave estimated from HF ocean radars

[1] Short-wave directional distributions estimated using HF (high-frequency) radar are compared with model predictions. The short-wave directional distributions are estimated on the basis of HF radar using two- and four-parameter parametric models to describe short-wave directional distributions. The model-predicted short-wave directional distributions are computed using the energy balance equation. The nonlinear interaction source function in the energy balance equation is calculated from both the exact computation and the discrete interaction approximation (DIA). The predicted short-wave directional distributions from the exact computation and the DIA are compared with those estimated using HF radar. The energy balance equation is simplified by neglecting the propagation term, and the validity of the simplification is investigated. It is found that the four-parameter model is more accurate than the two-parameter model to estimate short-wave directional distribution using HF radar. The model-predicted mean short-wave directions with respect to wind directions are correlated with those estimated from the HF radar. The short-wave direction change associated with a sudden wind shift can be reproduced both from the exact computation and the DIA. The predicted second-order moments of short-wave directional distributions are also correlated with those estimated from the HF radar. This result shows that the model can reproduce transient short-wave directional distributions associated with changes of wind direction. The short-wave directional distributions predicted by the exact computation are narrower than those predicted by the DIA and estimated using the HF radar. The simplification of the energy balance equation is not the main source of the short-wave prediction error.
Iron oxide mineralogy of placic horizons

SUMMARY The iron oxide mineralogy of 15 placic horizons from Germany, New Zealand, Belgium and U.K. was determined by differential X-ray diffraction (DXRD). All samples examined contained ferrihydrite and goethite, lepidocrocite occurred in 10, and six contained non-DCB-reducible, lithogenic hematite. Ferrihydrite was most readily identified in ‘untreated minus oxalate-treated’ DXRD patterns. Al-substitution of goethites ranged from 4 to 13 mole %. Mean crystallite dimensions varied from 11 to 21 nm and from 6 to 21 nm for the goethite (110) and (111) lines respectively, from 7 to 51 nm for the lepidocrocite (020) line (lath thickness), and from 55 to 134 nm for the hematite (104) line. These values are typical for goethites from carbon-rich environments with poor crystallization conditions, and for well crystalline lithogenic hematites. The DXRD method is ideally suited to the evaluation of the many selective dissolution techniques used in soil chemistry and mineralogy.
Precipitation over the Interior East Antarctic Ice Sheet Related to Midlatitude Blocking-High Activity

Abstract Intermittent atmospheric blocking-high activity in the South Tasman Sea is shown to play a key role in delivering substantial snowfall as far south as at least 75°S on the central East Antarctic Ice Sheet plateau. Typically, cyclones fail to penetrate this far (>1000 km) inland, and accumulation was thought to be dominated by clear-sky precipitation. In East Antarctica, the meridional cloud bands delivering the moisture originate from as far north as 35°–40°S, and appear to preferentially pass over the East Antarctic coast in a corridor from ∼120° to 160°E. Comparison of surface observations, model, and satellite data suggests that a few such episodes contribute a significant proportion of the (low) mean annual accumulation of the central East Antarctic Ice Sheet (e.g., an estimated 44% at Dome C over 18 days in December 2001–January 2002). Blocking-high-related incursions also cause abrupt increases in the surface wind speed (snow redistribution) and air temperature; this has implications for th.
Borehole electroseismic phenomena : field measurements and theory

A Stoneley wave propagating in a borehole generates a flow of pore fluid in permeable zones intersected by the borehole. In turn, this flow of pore fluid induces a streaming electrical field. This thesis is an experimental and theoretical investigation of the electrical fields induced by Stoneley waves. The main emphasis of this thesis is to understand the electroseismic phenomena that are observed in the field. In the first experiment described in this thesis, we measured Stoneley-wave-induced electrical fields in a borehole drilled through fractured igneous rocks. Analysis of field data confirms that the electrical fields that we measured were induced by fluid flow in fractures. The normalized amplitude of these electrical fields correlated with the fracture density log. In the second experiment, we measured Stoneley-wave-induced electrical fields in several boreholes in vuggy dolomite. In dolomite, the normalized amplitude of the Stoneley-wave-induced electrical field correlates with the porosity of the formation around the borehole. Further, the Stoneley-wave-induced electrical fields have anomalously high amplitudes at an isolated fracture that intersected two boreholes. To explain the experimental results, we developed a theoretical model for the Stoneley-wave-induced electrical fields. According to the model, the normalized amplitude of the Stoneley-wave-induced electrical field is proportional to the porosity and inversely proportional to the pore space tortuosity of a formation around a borehole. Moreover, the amplitude-versus-frequency behavior of this electrical field depends on the permeability of the formation. 0=1114
Oxygen Isotope Thermometry of Mafic Igneous Rocks

Measurements of $$O^{18}/O^{16}$$ ratios in phenocrysts from basalts of Hawaii, Tahiti, Tristan da Cunha, New Zealand, and Ross Island show that isotopie fractionations between mineral pairs are uniform from rock to rock. Typical values of the fractionations, expressed as 1,000 In a, are: plagioclase-magnetite, 2.1; plagio-clase-augite, 0.6; plagioclase-olivine, 0.9. On the basis of the laboratory-calibrated plagioclase magnetite pair, the isotopic fractionations represent a temperature of 1,020°-1,100° C, in agreement with field observations. For the corresponding mineral pairs in mafic intrusive rocks, the fractionations are about twice as great, indicating temperatures of isotopie equilibration below 800° C, probably as a result of retrograde exchange during slow cooling.
Influence of the quasi‐biennial oscillation on isentropic transport and mixing in the tropics and subtropics

The influence of the quasi-biennial oscillation (QBO) on isentropic transport and mixing in the tropical and subtropical stratosphere is investigated over a period of 6 years. The transport and mixing is quantified by the equivalent length diagnostic, calculated from tracers simulated in chemical transport models using European Centre for Medium-Range Weather Forecasting (ECMWF) analyzed winds. A new procedure for calculating equivalent length from tracers, such as nitrous oxide (N2O), with a tropical maximum or minimum is devised. Results from different tracers and different chemical transport models demonstrate the robustness of the equivalent length diagnostic. Equivalent length calculated both from an artificial tracer and from simulated N2O indicates that, when the QBO winds are easterly, mixing is inhibited in the tropics throughout the broad region occupied by the easterlies and that, when the QBO winds are westerly, mixing is strongly inhibited within the narrow region occupied by the westerlies themselves but is enhanced in the subtropics. Examination of absolute vorticity gradients and horizontal Eliasen-Palm (EP) fluxes (broken down into contributions from different zonal wavenumbers) suggests that, in the ECMWF analyses, barotropic shear instability of the westerly jet, as well as propagation of planetary waves from the extratropics, drives the subtropical mixing seen in the westerly phase.