Miracle-dz/UniFAR-FTUs huggingface dataset:
Discrete Element and Experimental Investigations of the Earth Pressure Distribution on Cylindrical Shafts

AbstractExperimental and numerical studies have been conducted to investigate the earth pressure distribution on cylindrical shafts in soft ground. A small-scale laboratory setup that involves a mechanically adjustable lining installed in granular material under an axisymmetric condition is first described. The earth pressure acting on the shaft and the surface displacements are measured for different induced wall movements. Numerical modeling is then performed using the discrete element method to allow for the simulation of a large soil displacement and particle rearrangement near the shaft wall. The experimental and numerical results are summarized and compared against previously published theoretical solutions. The shaft-soil interaction is discussed, and conclusions regarding soil failure and the earth pressure distributions in both the radial and circumferential directions are presented.
Agricultural Productivity and Non-Farm Employment: Evidence from Bangladesh

This paper provides evidence on the impacts of agricultural productivity on employment growth and structural transformation of non-farm activities. To guide the empirical work, this paper develops a general equilibrium model that emphasizes distinctions among non-farm activities in terms of tradable-non-tradable and the formal-informal characteristics. The model shows that when a significant portion of village income is spent on town/urban goods, restricting empirical analysis to the village sample leads to underestimation of agriculture's role in employment growth and transformation of non-farm activities. Using rainfall as an instrument for agricultural productivity, empirical analysis finds a significant positive effect of agricultural productivity growth on growth of informal (small-scale) manufacturing and skilled services employment, mainly in education and health services. For formal employment, the effect of agricultural productivity growth on employment is found to be largest in the samples that include urban areas and rural towns compared with rural areas alone. Agricultural productivity growth is found to induce structural transformation within the services sector with employment in formal/skilled services growing at a faster pace than that of low skilled services.
Effects of periodic atmospheric pressure variation on radon entry into buildings

Using a mathematical model, we have investigated the temporal variations of radon entry into a house basement in the presence of time-dependent periodic variations of barometric pressure as well as a persistent small steady depressurization within the basement. The tool for our investigation is an integral finite difference numerical code which can solve for both diffusive and advective flux of radon in the soil gas which is treated as a slightly compressible fluid. Two different boundary conditions at the house basement are considered: (1) a dirt floor basement so that diffusion is equally or more important than advective transport, and (2) an “impermeable” cement basement except for a 1-cm-wide crack near the perimeter of the basement floor; in which case, advective transport of radon flux dominates. Two frequencies of barometric pressure fluctuation with representative values of amplitudes, based on a Fourier decomposition of barometric pressure data, were chosen in this study: one with a short period of 0.5 hour with pressure amplitude of 50 Pa, the other a diurnal variation with a period of 24 hours with the typical pressure amplitude of 250 Pa. For a homogeneous soil medium with soil permeability to air between 10−13 and 10−10 m2, we predict that the barometric fluctuations increase the radon entry into the basement by up to 120% of the steady radon inflow into the basement owing to a steady depressurization of 5 Pa. If soil permeability heterogeneity is present, such as the presence of a thin layer of higher permeability aggregate immediately below the basement floor, radon flux due to atmospheric pumping is further increased. Effects of pressure pumping on radon entry are also compared to diffusion-only transport when the steady depressurization is absent. It is found that contribution to radon entry is significant for the basement crack configuration. In particular, for pressure pumping at 0.5-hour period and for a homogeneous medium of permeability of 10−10 m2, the radon entry is a factor of 10 larger than that predicted by the diffusion-only transport. This may help to explain indoor radon concentrations during times of low steady state driving force. Extending beyond radon transport, the results of this case study establish the importance of transient advective transport resulting from atmospheric pressure variation. These results may have relevance in the estimations of the transfer of trace gases such as methane and nitrous oxide across the soil-atmosphere interface and their impact on global climate changes.
Dynamics of circulation of the Japan Sea

Including mean flow forcing due to eddy-topography interaction in a numerical model of the Japan Sea appears to improve defects identified in previous modelling studies. Characteristic western boundary current overshoot (by the East Korea Warm Current) is reduced or eliminated while a southward undercurrent brings colder, fresher water along the Korean coast. Cyclonic circulation in the north includes a strengthened Liman Current. A more nearly continuous Nearshore Branch follows the Honshu shelf break with northward-flowing undercurrent. Interannual variability persists under fixed (seasonally repeating or annual mean) external forcing.
Ordovidan microfossils from the Ballast Formation (Girilambone Group) of New South Wales

The Ballast Formation (Girilambone Group) comprises quartzose sandstone turbidite and siltstone, and less common chert and mafic‐intermediate igneous rocks, that unconformably underlie Early Devonian strata in a wide tract of north central New South Wales. Conodonts and radiolarians extracted by acid dissolution of cherty rocks, indicate that the unit is of Llanvirn‐early Caradoc (Darriwilian‐Gisbornian) age. The Ballast Formation is a basinal sequence of cratonic derivation, but the limits of its depositional realm are poorly established.
IN DEVELOPING COUNTRIES

The global crisis and the expansionary government reaction in many countries has revamped the attention of policy makers and academics on the growth effects of large public debts. Recent empirical studies investigate the impact of public debt on growth in advanced and emerging countries. This paper aims at complementing the existing evidence focusing on developing countries, where the increase in domestic borrowing, already started before the crisis, requires a more comprehensive analysis, based not only on external debt, but on total public debt. Results on a panel of lowand middle-income countries over the period 1990-2007 show that public debt has a negative impact on output growth up to a threshold of 90 percent of GDP, beyond which its effect becomes irrelevant. This non-linear effect can be explained by country-specific factors since debt overhang is a growth constraint only in countries with sound macroeconomic policies and stable institutions. JEL Classification: F33, F34, F35, O11
Real‐time experimental forecast of the Peruvian tsunami of August 2007 for U.S. coastlines

At 23:41 UTC on 15 August 2007, an offshore earthquake of magnitude 8.0 severely damaged central Peru and generated a tsunami. Severe shaking by the earthquake collapsed buildings throughout the region and caused 514 fatalities. The tsunami resulted in three casualties and a representative maximum runup height of ∼7 m in the near field. The first real‐time tsunami data available came from a deep‐ocean tsunami detection buoy within 1 hour of tsunami generation. These tsunami data were used to produce initial experimental forecasts within 2 hours of tsunami generation. The far‐field forecasts indicated that the tsunami would not flood any of the 14 U.S. communities. Comparison with real‐time tide gage data showed very accurate forecasts.
Investigation of subsurface water flow along the continental margin of the Eurasian Basin using the transient tracers tritium, 3He, and CFCs

During August–September 1993 the R/V Polarstern expedition ARK IX/4 was made to the Eurasian continental margin of the Arctic Ocean. Sections of oceanographic stations leading from the outer shelf over the continental slopes toward the deep Eurasian Basin were occupied north of the Barents and Laptev Seas. The distributions of the transient tracers CFC-11, CFC-12, tritium, and 3He were measured along these sections and are discussed in relation to water mass distribution and circulation along the continental margin of the Eurasian Basin. The tracer data strongly corroborate the temperature and salinity data [Schauer et al., 1997], clearly showing the inflow of Atlantic water in two branches, the Fram Strait branch and the Barents Sea branch. High CFC and tritium concen-trations extended down to 1300 m over the Laptev continental slope, indicating strong inflow of the Barents Sea branch between Franz Josef Land and Severnaya Zemlya. The apparent ages of water in the Fram Strait branch were estimated to be about 2 years north of the Barents Sea and 6 years at the eastern end of the Nansen Basin, which corresponds to an apparent mean current speed of about 1 cm s−1. The age of the core of the Barents Sea branch was also estimated to be about 6 years over the Laptev slope region and to increase by 0.5 years as it flowed through this region. A lower limit for the inflow of newly formed Barents Sea Branch Water was estimated to be 0.5 Sv, and an overall transport for the sum of Fram Strait branch plus Barents Sea branch flow of 4 Sv was estimated from this aging. In the deep water there was clear evidence for the inflow of Norwegian Sea Deep Water through Fram Strait, but there appeared to be no significant input of shelf-derived water from the Santa Anna Trough. If there was any shelf-derived input to Eurasian Basin Bottom Water, it entered at a deeper depth than was sampled on the slope sections in the Laptev Sea or its flow is intermittent and was not occurring during the ARK IX/4 expedition.
A Quasi‐Biennial Oscillation in the equatorial Atlantic Ocean

A quasi‐biennial oscillation with features characteristic of equatorial coupled modes is found in the equatorial Atlantic Ocean. The origins of the phenomenon are investigated by using a coupled atmosphere‐ocean general circulation model, in which the fully coupled domain is restricted to the Tropical Atlantic (20°S–30°N). The simulations capture a similar oscillation regardless of whether sea surface temperatures prescribed outside the coupled domain correspond to the observed or the climatology (i.e., lack year‐to‐year variability). It is concluded that the equatorial Atlantic hosts a quasi‐biennial oscillation generated by coupled atmosphere‐ocean interactions internal to the basin with little influence from remote events, even from El Niño/Southern Oscillation.
Observations of Superinertial and Near-Inertial Wind-driven Flow

Abstract The superinertial and near-inertial wind-driven flow in the western North Atlantic is examined using data from two recent experiments. The Frontal Air–Sea Interaction Experiment (FASINEX) took place at 27°N, 70°W during 1986. The Long-Term Upper-Ocean Study (LOTUS) took place at 34°N, 70°W during 1982. Each experiment included moored measurements of meteorological variables that allowed estimation of the wind stress and oceanic currents. The directly wind-driven flow is isolated from other sources of variability, such as internal waves and mooring motion, using a transfer function between geocentric acceleration and wind stress. The transfer function is examined in rotary spectral bands bounded by periods of 36 and 12 h, and 12 and 2 h. For surface-moored observations, wind-driven mooring motion is found to cause a response that extends at least to 1000 m (much deeper than the frictional layer of direct wind forcing). Once this artifact is removed, the directly wind-driven flow is identified. Thi.
Defining ‘local signature’ in terms of Sr isotope composition using a tenth- to twelfth-century Anglo-Saxon population living on a Jurassic clay-carbonate terrain, Rutland, UK

Abstract The Sr isotope ratios and Sr concentration in tooth enamel from a rural tenth-twelfth century Anglo-Saxon population living on a Jurassic clay-carbonate terrain in eastern England gives the following mean values: 87Sr/86Sr=0.7098±0.0018 (2σ, n=22) and Sr concentrations = 74±62 p.p.m. (2σ). The isotope data are taken to be representative of Anglo-Saxon biosphere values in the area of study. The Sr isotope composition of soil leachates, plant material, riverwaters and animal tooth enamel associated with the burial site were all analysed to see which gave the best approximation to these local Anglo-Saxon values, the aim being to define the best method of predicting the local Sr signature of areas for archaeological purposes. The Sr isotope composition of acetic acid soil leachates were dominated by the carbonate soil component and gave 0.7085±0.0020 water leachates gave 0.7090±0.0014 and plant material gave 0.7092±0.0018 (all at 2σ, n=12). All of these materials were less radiogenic that those of the Anglo-Saxon population. Riverwater gave the same result as the plants at 0.7092±0.0012 (2σ, n=3). The Anglo-Saxon animal tooth enamel gave the best match with a value of 0.7099±0.0017 (2σ, n=13). Analysis of variance (ANOVA) tests show that there is a high probability (>70% probability, 2SD) that the animals and the humans sampled were from the same population with respect to Sr isotope composition. Thus animal tooth enamel proved to be the best proxy, in this study, for the local human population.
On the relation between seismic anisotropy and finite strain

Because seismic anisotropy in the upper mantle is due primarily to lattice preferred orientation (LPO) of olivine crystals induced by deformation, observations of anisotropy can provide constraints on mantle deformation and flow. In this paper, we use a previously published theory for deformation-induced LPO (Ribe and Yu, 1991) to quantify the relation between seismic anisotropy and deformation for two model compositions: a pure olivine (dunite) aggregate, and a harzburgite comprising 70% olivine and 30% enstatite. Analytical and numerical solutions of the governing equations show that the predicted LPO (and hence also the seismic anisotropy) depends only on the finite strain, and not on the deformation path by which that strain is produced. The magnitude of the anisotropy depends only on the ratios c1/c2 and c2 /c3, where c1 > c2 > c3 are the lengths of the principle axes of the finite strain ellipsoid, and the directions of maximum and minimum compressional wave velocity Vp coincide with the axes c1. and c3, respectively. We calculate the percent anisotropies for compresional and shear waves propagating along the three principle axes of the finite strain ellipsoid, as functions of the axial ratios c1/c2 and c2 /c3, for our two model compositions. However, inferences of the magnitude of finite strain obtained using these results are likely to be minimum estimates because our theory neglects the effects of dynamic recrystallization. Finally, we present, as a byproduct of this study a new direct method for calculating the finite strain produced by an arbitiary deformation history.
Late Quaternary geomagnetic secular variation from historical and 14C‐dated lava flows on Hawaii

A paleomagnetic record of geomagnetic paleosecular variation (PSV) is constructed for the last 4400 years based on 191 sites in historical and 14C-dated lava flows from Mauna Loa, Kilauea, and Hualalai Volcanoes on the island of Hawaii. The features of this new record are similar to those recorded by sediments from Lake Waiau near the summit of Mauna Kea Volcano, but overall mean inclinations for the lava flows (31° to 33°, depending on window size) are nearer the expected dipole-field value (35°) than is that for the sediments (27°). Divergence of the inclination records with increasing age suggests that the Lake Waiau values at depths below 2 m have been affected by compaction-related inclination shallowing, although magnetic terrain effects cannot be ruled out. The rate of PSV indicated by the record presented here is highly variable ( 20°/century), and a pronounced shift in inclination from 25° to 40° occurred between ∼1030 and ∼975 years B.P. Paleomagnetic directions from undated materials can be correlated with our calibrated curve, but the resolution is largely dependent on the PSV rate and data densities for both the reference and unknown directions. The upper part of the Puna Basalt (18 lava flows), previously sampled for paleomagnetism along the northern wall of Kilauea's caldera (Uwekahuna Bluff), was likely deposited sometime between 1030 and 750 years B.P., but the lowest two flows beneath the Uwekahuna Ash (∼2100 years B.P.) are correlated with an age of ∼3034 years B.P. Paleomagnetic data for 54 lava flows of the Ka'u Basalt, exposed in the northwest wall of Mauna Loa's summit caldera (Mokuaweoweo), indicate that they probably accumulated over a relatively short time interval (∼200+ years) and are assigned to a 1000 to 1199 year B.P. time window. The mean of ages within this window is ∼1030 years B.P., but mapping and other 14C dates indicate that these summit overflows are probably closer to ∼1200 years B.P. in age.
Lower Devonian dalmanitid trilobites of the Prague Basin (Czech Republic)

ABSTRACT A revision of the Lower Devonian dalmanitid trilobites of the Prague Basin (Czech Republic) is presented. The subfamily Odontochilinae Šnajdr is considered a synonym of Dalmanitidae Vogdes. Twenty-one previously and five newly described (three in open nomenclature) species and subspecies occur in the Prague Basin from the lowermost Pragian (one problematic specimen possibly comes from the uppermost Lochkovian) to the Lower Emsian; the last questionable record is from the Upper Emsian. The species have been assigned to four genera and subgenera: Odontochile Hawle & Corda, Reussiana Šnajdr, Zlichovaspis (Zlichovaspis) Přibyl & Vaněk and Zlichovaspis (Devonodontochile) Šnajdr. These trilobites are considered as scavengers or opportunistic predators, living most of their lives as vagrant benthos burying in the muddy substrate to find organic remains. The first undoubted adult-like meraspid specimens are described.
A model for entrainment of sediment into sea ice by aggregation between frazil-ice crystals and sediment grains

Abstract Avertical numerical model has been developed that simulates tank experiments of sediment entrainment into sea ice. Physical processes considered were: turbulent vertical diffusion of heat, salt, sediment, frazil ice and their aggregates; differential growth of frazil-ice crystals; secondary nucleation of crystals; and aggregation between sediment and ice. The model approximated the real size distribution of frazil ice and sediment using five classes of each. Frazil crystals (25 μm to 1.5 cm) were modelled as discs with a constant thickness of their diameter. Each class had a constant rise velocity based on the density of ice and drag forces. Sediment grains (1–600 μm) were modelled as constant density spheres, with corresponding sinking velocities. The vertical diffusion was set constant for experiments based on calculated turbulent rms velocities and dissipation rates from current data. The balance between the rise/sinking velocities and the constant vertical diffusion is an important feature of the model. The efficiency of the modeled entrainment process was estimated through α, an aggregation factor. Values for α are in the range 〈0.0003, 0.1〉, but average values are often close to 0.01. Entrainment increases with increasing sediment concentration and turbulence of the water, and heat flux to the air.
Strontium isotopic evidence for prehistoric transport of gray‐ware ceramic materials in the eastern Grand Canyon region, USA

Through a novel application of strontium (Sr) isotopic analysis, we evaluate geological sources for prehistoric ceramics in the eastern Grand Canyon region of northern Arizona, focusing on two gray‐ware traditions in the Upper Basin of the Coconino Plateau. Building on a conceptual framework for the general potential of Sr isotopes in the analysis of geological materials, we suggest that the eastern Grand Canyon is specifically well suited archaeologically and geologically for: (1) exploring the utility of Sr isotopes for ceramic provenance research and (2) testing long‐standing hypotheses that gray‐ware ceramics were invariably made with local materials. Sr isotopic compositions indicate that the ceramic samples represent at least three different geological sources, and that different raw materials were used in the manufacture of the two gray‐ware traditions found in the Upper Basin. One of the gray‐ware traditions is not compositionally consistent with local geology, indicating that either the ceramics or the raw materials were transported at least 20 km to the Upper Basin. © 2011 Wiley Periodicals, Inc.
Ammonia abundance in Jupiter's atmosphere derived from the attenuation of the Galileo probe's radio signal

The radio signal from the Galileo probe to the orbiter experienced attenuation due to ammonia in Jupiter's atmosphere during the probe descent. A profile of the ammonia content as a function of depth in the atmosphere has been derived from the measurements of the attenuation. The derived ammonia abundance rises to a molar fraction of 700±100 parts per million for pressures greater than 7 bars, about 4 times that expected based on the solar abundance of nitrogen.
Characterization of water-soluble organic matter isolated from atmospheric fine aerosol

[1] Atmospheric fine aerosol (dp < 1.5 μm) was collected at a rural site in Hungary from January to September 2000. The total carbon concentration ranged from 5 to 13 μg m−3 and from 3 to 6 μg m−3 in the first three months and the rest of the sampling period, respectively. On average, water-soluble organic carbon (WSOC) accounted for 66% of the total carbon concentration independent of the season. A variable fraction of the water-soluble organic constituents (38–72% of WSOC depending on the sample) was separated from inorganic ions and isolated in pure organic form by using solid phase extraction on a copolymer sorbent. This fraction was experimentally characterized by an organic matter to organic carbon mass ratio of 1.9, and this value did not change with the seasons. Furthermore, the average elemental composition (molar ratio) of C:H:N:O ≈ 24:34:1:14 of the isolated fraction indicated the predominance of oxygenated functional groups, and the low hydrogen to carbon ratio implied the presence of unsaturated or polyconjugated structures. These conclusions were confirmed by UV, fluorescence, and Fourier transform infrared (FTIR) studies. On the basis of theoretical considerations, the organic matter to organic carbon mass ratio was estimated to be 2.3 for the nonisolated water-soluble organic fraction, resulting in an overall ratio of 2.1 for the WSOC. In order to extend the scope of this estimation to the total organic carbon, which is usually required in mass closure calculations, the aqueous extraction was followed by sequential extraction with acetone and 0.01 M NaOH solution. As a result, a total organic matter to total organic carbon mass ratio of 1.9–2.0 was estimated, but largely on the basis of experimental data.