Miracle-dz/UniFAR-FTUs huggingface dataset:
Onshore Migration of a Swash Bar During a Storm

Abstract The morphodynamics of a swash bar was monitored over two tidal cycles during a storm event at Skallingen, Denmark. Higher water levels during the first tidal cycle forced waves to break either landward of, or at, the bar crest. The bar was unable to significantly alter the pattern of wave breaking over the foreshore slope, creating a potential for bar erosion through an offshore transport of sediment. In response, the bar became more symmetric in cross-section, and its height decreased. Lower water levels during the second tidal cycle forced waves to break on the seaward slope, causing the bar to rebuild and its crest to migrate onshore. The onshore migration of the swash bar occurred despite little change in the offshore wave height from one tidal cycle to the next and in conditions that are typically associated with offshore transport and bar migration. The results further illustrate a strong tidal dependency in which water depth relative to bar height is an important control on the morphodynamics of the swash bar, but in a manner that appears contrary to recent evidence from the subtidal zone. Cospectra of velocity and concentration from collocated sensors during the second tidal cycle exhibited a strong infragravity signal, with sediment resuspension largely restricted to the onshore phase of the infragravity oscillations. Suspension during this phase was associated with the passage of individual surf bores and exhibited a depth-dependent phase lag with the velocity accelerations at the leading face of the wave. It is proposed that the primary role of the acceleration is to alter the amount of sediment suspended, with a net onshore transport accomplished by the skewness in the oscillatory velocity field. However, the onshore migration of the swash bar could only be explained by the gradient in the acceleration skewness, which was sufficiently coupled spatially with the morphology.
Synaptic Amplifier of Inflammatory Pain in the Spinal Dorsal Horn

Inflammation and trauma lead to enhanced pain sensitivity (hyperalgesia), which is in part due to altered sensory processing in the spinal cord. The synaptic hypothesis of hyperalgesia, which postulates that hyperalgesia is induced by the activity-dependent long-term potentiation (LTP) in the spinal cord, has been challenged, because in previous studies of pain pathways, LTP was experimentally induced by nerve stimulation at high frequencies (∼100 hertz). This does not, however, resemble the real low-frequency afferent barrage that occurs during inflammation. We identified a synaptic amplifier at the origin of an ascending pain pathway that is switched-on by low-level activity in nociceptive nerve fibers. This model integrates known signal transduction pathways of hyperalgesia without contradiction.
Comment on Vimalananda et al . Depressive symptoms , antidepressant use , and the incidence of diabetes in the Black Women ’ s Health Study

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Comment on Vimalananda et al. Depressive symptoms, antidepressant use, and the incidence of diabetes in the Black Women’s Health Study. Diabetes Care 2014;37:2211-2217. Mika Kivimäki, Archana Singh-Manoux
Poroelastic rebound along the Landers 1992 earthquake surface rupture

Maps of surface displacement following the 1992 Landers, California, earthquake, generated by interferometric processing of ERS-1 synthetic aperture radar (SAR) images, reveal effects of various postseismic deformation processes along the 1992 surface rupture. The large-scale pattern of the postseismic displacement field includes large lobes, mostly visible on the west side of the fault, comparable in shape with the lobes observed in the coseismic displacement field. This pattern and the steep displacement gradient observed near the Emerson-Camp Rock fault cannot be simply explained by afterslip on deep sections of the 1992 rupture. Models show that horizontal slip occurring on a buried dislocation in a Poisson's material produces a characteristic quadripole pattern in the surface displacement field with several centimeters of vertical motion at distances of 10–20 km from the fault, yet this pattern is not observed in the postseismic interferograms. As previously proposed to explain local strain in the fault step overs [Peltzer et al., 1996b], we argue that poroelastic rebound caused by pore fluid flow may also occur over greater distances from the fault, compensating the vertical ground shift produced by fault afterslip. Such a rebound is explained by the gradual change of the crustal rocks' Poisson's ratio value from undrained (coseismic) to drained (postseismic) conditions as pore pressure gradients produced by the earthquake dissipate. Using the Poisson's ratio values of 0.27 and 0.31 for the drained and undrained crustal rocks, respectively, elastic dislocation models show that the combined contributions of afterslip on deep sections of the fault and poroelastic rebound can account for the range change observed in the SAR data and the horizontal displacement measured at Global Positioning System (GPS) sites along a 60-km-long transect across the Emerson fault [Savage and Svarc, 1997]. Using a detailed surface slip distribution on the Homestead Valley, Kickapoo, and Johnson Valley faults, we modeled the poroelastic rebound in the Homestead Valley pull apart. A Poisson's ratio value of 0.35 for the undrained gouge rocks in the fault zone is required to account for the observed surface uplift in the 3.5 years following the earthquake. This large value implies a seismic velocity ratio Vp/Vs of 2.1, consistent with the observed low Vs values of fault zone guided waves at shallow depth [Li et al., 1997]. The SAR data also reveal postseismic creep along shallow patches of the Eureka Peak and Burnt Mountain faults with a characteristic decay time of 0.8 years. Coseismic, dilatant hardening (locking process) followed by post-seismic, pore pressure controlled fault creep provide a plausible mechanism to account for the decay time of the observed slip rate along this section of the fault.
Tempe Fossae, Mars: A planetary analogon to a terrestrial continental rift?

Tempe Terra, the northeastern part of the Tharsis Region on Mars, is characterized by several extensional structures differing in style and age. The Tempe Fossae, a particularly well-developed system of graben striking N45°E, have been studied for the first time in detail on the basis of Viking Orbiter imagery and Mars Observer Laser Altimeter (MOLA) topographic data. The graben system appears to be unique in the whole region because of its extent, the remarkable width and depth of the graben, the varying graben pattern, and the associated volcanism. Single graben can be up to 35 km wide and 120 km long, while their depth can reach nearly 3000 m. They typically show an asymmetric architecture, often in halfgraben or step fault style. The graben system widens and changes its style along strike from NE to SW from a single, very deep, and narrow graben to a complex set of several shallower, sinuous graben and halfgraben. Crustal extension was measured in the northeastern part from the observable throw and amounts to 2.5–3.1 km. Volcanic structures can be found at several locations along the graben. In the SW the graben system seems to be connected with the Tempe Terra volcanic province marked by flood basalts and plains volcanism. Craters were counted on volcanic units unaffected by extensional tectonics. Crater statistics indicate an absolute crater model age for the upper end of the extensional deformation of ∼3.5 Ga. The dimensions and the characteristics of the mapped graben system resemble those of terrestrial continental rifts, and a comparison between them and the Kenya Rift reveals striking similarities. Therefore the Tempe Fossae are interpreted as a Martian analog to a continental rift associated with an underlying mantle plume. This hypothesis seems to be supported by recent geophysical models based on topography and gravity data from Mars Global Surveyor which indicate regional uplift for Tempe Terra.
On the efficiency of solar heating in the middle atmosphere

We calculate the efficiency at which solar ultraviolet radiation absorbed in the Hartley band of ozone is directly converted to heat in the terrestrial mesosphere and lower thermosphere (50–110 km). The ozone molecule undergoes photolysis to yield the excited species O(¹D) and O2(¹Δ) with a quantum yield of about 0.9. Spontaneous emission from O2(¹Δ) and from O2(¹Σ) (excited by energy transfer from O(¹D)) significantly decreases the amount of energy available for heat. Similarly, we calculate the efficiency at which solar ultraviolet radiation absorbed by O2 in the Schumann-Runge continuum is directly converted to heat in the lower thermosphere (95–110 km). The O2 undergoes photolysis and the excited product O(¹D) is generated. Spontaneous emission from O2(¹Σ) (excited by energy transfer from O(¹D)) reduces the amount of energy available for heat in the lower thermosphere. The consideration of these energy transfer and loss processes results in significantly reduced heating rates as compared to those conventionally calculated in models of the middle atmosphere.
Modeling of slow slip events along the deep subduction zone in the Kii Peninsula and Tokai regions, southwest Japan

[1] In the subduction zone of southwest Japan, short-term slow slip events (SSEs) occur with low frequency tremors (LFTs) at intervals of several months. Recently LFTs have been located with high resolution and their activities have been examined in detail. By setting the generation zones of SSEs such that these zones contain the LFT hypocenters, we simulate SSEs on a 3D plate interface beneath the Kii Peninsula and Tokai regions by using a rate- and state-dependent friction law with a small cut-off velocity for the evolution effect. Our numerical results show that recurrence intervals of SSEs in the southern and central Kii Peninsula, in the northern Kii Peninsula, and in the Tokai region are 2.5–3.0, 4.8–5.6, and 3.5–4.5 months, respectively, which are consistent with observed SSE activity. Our simulation also produces a multisegment event that propagates from the Kii to Tokai segments at a speed of 10 km/day, which is consistent with observations. The results suggest that generation zones of LFTs coincide with SSE regions and that these two events are different manifestations of the same slip process along the subduction zone. We also perform 3D modeling of faster events accompanied by short-term SSEs by considering local circular patches with a smaller critical displacement, surrounded by SSE zones with a larger critical displacement. Local circular patches are set at the observed LFT locations. The simulation reproduces fast events that propagate at a speed of 100–200 km/day during a single SSE event.
Tephrostratigraphy, chronology and climatic events of the Mediterranean basin during the Holocene: An overview

The identification and characterisation of high-frequency climatic changes during the Holocene requires natural archives with precise and accurate chronological control, which is usually difficult to achieve using only 14C chronologies. The presence of time-spaced tephra beds in Quaternary Mediterranean successions represents an additional, independent tool for dating and correlating different sedimentary archives. These tephra layers are potentially useful for resolving long-standing issues in paleoclimatology and can help towards correlating terrestrial and marine paleoclimate archives. Known major tephras of regional extent derive from central and southern Italy, the Hellenic Arc, and from Anatolia. A striking feature of major Holocene tephra deposition events in the Mediterranean is that they are clustered rather than randomly distributed in time. Several tephra layers occurred at the time of the S1 sapropel formation between c. 8.4 and 9.0 ka BP (Mercato, Gabellotto-Fiumebianco/E1, Cappadocia) and other important tephra layers (Avellino, Agnano Monte Spina, ‘Khabur’ and Santorini/Thera) occurred during the second and third millennia BC, marking an important and complex phase of environmental changes during the mid- to late-Holocene climatic transition. There is great potential in using cryptotephra to overlap geographically Italian volcanic ashes with those originating from the Aegean and Anatolia, in order to connect regional tephrochronologies between the central and eastern Mediterranean.
A projection of severe near‐surface permafrost degradation during the 21st century

The current distribution and future projections of permafrost are examined in a fully coupled global climate model, the Community Climate System Model, version 3 (CCSM3) with explicit treatment of frozen soil processes. The spatial extent of simulated present‐day permafrost in CCSM3 agrees well with observational estimates – an area, excluding ice sheets, of 10.5 million km2. By 2100, as little as 1.0 million km2 of near‐surface permafrost remains. Freshwater discharge to the Arctic Ocean rises by 28% over the same period, largely due to increases in precipitation that outpace increases in evaporation, with about 15% of the rise directly attributable to melting ground ice. Such large changes in permafrost may provoke feedbacks such as activation of the soil carbon pool and a northward expansion of shrubs and forests.
Chapter 62 The Port Askaig Formation, Dalradian Supergroup, Scotland

Abstract The Port Askaig Formation (Fm.) is a thick glaciogenic succession within the Dalradian Supergroup that consists of over 700 m of variably dolomitic diamictite, conglomerate, sandstone mudstone and minor dolomite, and is bounded by mixed siliciclastic–carbonate successions of the Islay (Lossit) and Bonahaven formations. These strata are exposed in the metamorphic Caledonides of Scotland, although excellent preservation of sedimentary structures can be found at several sites. An extensional setting for this succession has been proposed based on stratigraphic and structural arguments. The available chemostratigraphic data include the Chemical Index of Alteration, δ13C and Sr-isotope values. Palaeomagnetic analyses have been shown to be subject to post-depositional Caledonian overprinting. There is also continued debate over the regional palaeogeographical reconstructions of the Scottish promontory for this time period. The succession is chronologically poorly constrained with U–Pb analyses of stratigraphically much higher or lower deposits. The thick succession is thought to record glacially influenced marine sedimentation and reworking of unstable sediments in a tectonically active setting with evidence of ice-margin fluctuations. Alternative palaeoenvironmental interpretations that focus on glacial terrestrial processes and emphasize climatic influence instead of tectonic activity have also been proposed. The overlying carbonate is a lithologically diverse coastal complex and so does not fit the Neoproterozoic norm. Research has to date focused on the stratigraphic and sedimentological aspects of this succession, as well as some of the broader palaeogeographical and structural features of the Dalradian basin. Future efforts should focus on the chronological, structural and palaeogeographical constraints of this succession.
Umbrella file system: Storage management across heterogeneous devices

With the advent of and recent developments in Flash storage, device characteristic diversity is becoming both more prevalent and more distinct. In this article, we describe the Umbrella File System (UmbrellaFS), a stackable file system designed to provide flexibility in matching diversity of file access characteristics to diversity of device characteristics through a user or system administrator specified policy. We present the design and results from a prototype implementation of UmbrellaFS on both Linux 2.4 and 2.6. The results show that UmbrellaFS has little overhead for most file system operations while providing an ability better to utilize the differences in Flash and traditional hard drives. With appropriate use of rules, we have shown improvements of up to 44% in certain situations.
First observation of topside ionization ledges using radio beacon measurements from low Earth orbiting satellites

Ionization ledges in the topside ionosphere have been observed from Trivandrum (8.5°N, 77°E, 0.5°N dip) using single station Total Electron Content (TEC) measurements. These measurements are made using a ground based radio beacon receiver. The receiver measures the relative phase between 150 MHz and 400 MHz beacon transmissions from a Low Earth Orbiting Satellite (LEOS). The ionization ledges, which could be observed, using only topside sounders so far, are seen to have their clear signatures in relative TECs derived using differential Doppler measurements. Simulations were also carried out to understand how the ionospheric topside ledges of various intensities would manifest in the latitudinal profiles of the relative TEC. The magnetometer observations indicate the presence of the Equatorial Counter Electrojet (CEJ) on the days when the ledge is observed. The study demonstrates the potential of radio beacon measurements for observing topside ionization ledges, and phenomena similar to it.
Particle image velocimetry measurement of in-cylinder flow in internal combustion engines-experiment and flow structure analysis

Abstract A cross-correlation digital particle image velocimetry (PIV) system has been developed and applied to study the in-cylinder flow in a single-cylinder engine with a production-type cylinder head. The PIV system set-up and its optimization are described in the first part of the paper. Two-dimensional velocity distributions measured over 100 cycles are analysed to obtain ensemble-averaged mean and fluctuating velocities, the turbulent length scale, vorticity and strain rate distribution in the measurement plane. In particular, a spatial filtering scheme is developed in order to obtain the cycle-resolved velocity measurements. The cycle-resolved analysis shows that the low-frequency velocity fluctuation component (i.e. cyclic variation) is mainly responsible for the spatial variation in velocity and turbulent kinetic energy distributions. The integral length scale calculated from the PIV data is between 6 and 10 mm and the strain rate is estimated to be within 1000 s-1 in most areas of the measurement plane.
Face-to-Face and E-learning Styles for Undergraduate Engineering Technology Students During COVID-19 Pandemic

Education has changed dramatically with the surging growth of online learning since the COVID-19 pandemic began, and the entire globe has turned away from the classrooms. Teaching has moved to be via digital platforms. With this abrupt shift to digital learning, a concern has been raised about how this shift will affect worldwide learning. This research aims to study the impact of the COVID-19 switch on student performance and whether online learning can deliver the same academic student performance as face-to-face. The data of this study was compiled from three engineering courses taught at the engineering technology department at a public university in Texas. The complexity of these courses ranges from low, average, and high levels for courses A, B, and C, respectively. An analysis of variance (ANOVA) was used to compare the differences in student performance outcomes of three exams and other graded assignments. The impact of four learning modalities, involving face-to-face (F2F), synchronous, asynchronous, and mixed (F2F and synchronous), was explored. The results of the overall mean scores show that, for courses B and C, the student performance outcomes are higher in the mixed (F2F and synchronous) and online groups (synchronous and asynchronous groups) than in the F2F group. For course A, there is a significant difference in the overall academic performance of online learning modes compared to F2F. Whereby, in general, the F2F mode deliver a higher level of student performance outcomes than that delivered by mixed and asynchronous groups for these kinds of courses. © American Society for Engineering Education, 2021
Measurement of bedload gravel transport: The calibration of a self-generated noise system

Self-generated noise (SGN) is a passive acoustic technique for the measurement of bedload transport through the acoustic detection of intergranular collisions using a submerged hydrophone system. SGN is of interest because of the possibilities it offers to the measurement of transport parameters at the frequencies of turbulent or oscillating current scales. This paper describes the background of the technique, and reports the results from laboratory experiments on the relationship between SGN and the absolute transport rate.
El Efecto Fisher y la Paridad de Interés Real. Evidencia Para la Economía Española

RESUMEN En este trabajo se contrasta empíricamente el cumplimiento de la hipótesis de Fisher y de la paridad de interés real para el caso español. El objetivo es comprobar si determinaron el comportamiento del tipo de interés real ex-ante que condiciona las decisiones intertemporales de ahorro e inversión. Para ello se utiliza la metodología de series temporales, en particular el procedimiento de Johansen, que permite diferenciar entre los efectos a largo plazo y la dinámica del corto cación en el largo plazo de la hipótesis de Fisher ajustada por impuestos pero no así de la paridad de interés real.
Compression model for cohesionless soils

A simple four-parameter elasto-plastic model describes the non-linear volumetric behaviour of freshly deposited cohesionless soils in hydrostatic and one-dimensional compression. It expresses the tangent bulk modulus as a separable function of the current void ratio and mean effective stress using natural strains. Specimens compressed from different initial formation densities approach a unique response at high stress levels—the limiting compression curve (LCC)—which is linear in a double logarithmic void ratio-effective stress space. The model describes irrecoverable, plastic strains which develop throughout first loading and represent mechanisms ranging from particle sliding and rolling at low stresses to crushing—the principal component of deformation for LCC states. The three input parameters describing plastic deformation can be readily estimated from a hydrostatic or one-dimensional compression test loaded to high stress levels; the elastic bulk modulus requires accurate small strain measurements in.