Miracle-dz/UniFAR-FTUs huggingface dataset:
Isothermal compression of the alloys of iron up to 300 kilobars at room temperature: Iron‐nickel alloys

The effect of pressure on the crystal structure and the molar volume of iron alloyed with 5 and 10% nickel was determined up to 300 kb at room temperature by means of X-ray diffraction techniques employing a diamond-anvil high-pressure cell. The alloys undergo a reversible bcc-hcp phase transformation, which is accompanied by a volume change of −0.36 ± 0.02 cm3/mole. The crystallographic axis ratio, c/a, of the hcp phase appears to increase with nickel content, whereas it appears to be unaffected by pressure. The bulk moduli calculated from the volume data for the bcc and hcp phases of the alloys do not differ significantly from those for the respective phases of iron. The bulk modulus value for the hcp phase evaluated at zero pressure has been calculated to be 2.06 ± 0.15 Mb and is about 20% greater than that for the bcc phase. The volume of the hcp phase at zero pressure has been calculated from the pressure-volume data by extrapolation. A value of 6.67 ± 0.02 cm3/mole has been obtained for iron and the alloys. The pressure-volume relationship obtained by this work is consistent with the results obtained by R. G. McQueen and S. P. Marsh (1960, 1966) using shock compression techniques.
The thermal gradient of Callisto constrained by Asgard Basin: Rheological and chemical implications

Using the width of concentric grabens formed during the relaxation of the Asgard basin on Callisto, in combination with rheological flow laws of ice and laws concerning the variations in strain rate around a relaxing crater, the surface thermal gradient of Callisto at −4 b.y. is estimated to be near 0.5°K km−1. It is assumed that the graben width depends on the depth of the brittle/ductile transition zone. Around the Asgard basin, the depth of this brittle/ductile transition zone varies from 23 km (at 200 km from the crater rim) to 4 km (at 800 km from the crater rim). It is assumed that the thermal characteristics were constant over the extended zone and that the difference in the depth of the brittle/ductile transition zone is only due to differences in the strain rate around the basin during the relaxation of the initial cavity. Calculations show that Newtonian flow law for ice gives a strain rate of external relaxation at the crater rim of about 10−14 s−1, while a power law gives a strain rate of about 10−6 s−1, assuming a surface temperature between 100 and 150°K. The order of magnitude of the calculated thermal gradient is independent of the chosen flow law. This calculated gradient is, however, one order of magnitude lower than those calculated theoretically with a chondritic abundance of radioactive elements in the silicate part of Callisto.
The seasonal and vertical distribution of living planktic foraminifera in the NW Arabian Sea

Abstract The NW Arabian Sea is characterized by a strong seasonal contrast in surface water hydrography. During the SW monsoon of 1992, we encountered strong coastal upwelling characterized by low sea surface temperatures (SST), high nutrient concentrations, a shallow thermocline and a near-surface chlorophyll maximum. By contrast, the hydrography during the NE monsoon of 1993 was characterized by a relatively warm nutrient-depleted surface mixed layer and a deep chlorophyll maximum. We show that the faunal composition, depth habitat and abundance of living planktic foraminifera respond to the hydrographic changes controlled by the seasonally reversing monsoon system. Total shell concentrations (> 125 μm) ranged from 4 to 332 individuals (ind.) m−3 during upwelling and from 3 to 85 ind. m−3 during the non-upwelling season. During upwelling, the fauna was dominated by Globigerina bulloides. During non-upwelling the fauna was characterized by relatively high concentrations of tropical symbiont-bearing species such as Globigerinoides ruber, Globigerinoides sacculifer and Globigerinella siphonifera, whereas concentrations of Globigerina bulloides were an order of magnitude lower. Factor analysis on 15 species yields an upwelling assemblage (UA), a tropical assemblage (TA) and a subsurface assemblage (SA). A fourth factor represents the distribution of the species Globigerina falconensis, which is mainly found in subsurface waters during the non-upwelling period (NE monsoon). A model is presented to calculate the base of the productive zone from the vertical shell concentration profile of a given species. The model is validated by comparing the range in calcification temperatures of G. bulloides, derived from its δ18O, with the in situ sea-water temperature range of the productive zone as predicted from the model. It appears that shell growth (calcite precipitation) is restricted to the productive zone as defined by this method. The average calcification temperature of G. bulloides corresponds to the point of maximum change in the shell concentration profile (i.e. the inflection point). For most shallow-dwelling species, the inflection point is found at or below the depth of the chlorophyll maximum, although above the main thermocline. This study indicates that the depth habitat and abundance of different species varies seasonally. Consequently, the abundance and stable isotope composition of specimens in the fossil record reflects a mixture of specimens that were produced at various depths during the different seasons.
Simulated Impacts of Crop Residue Removal and Tillage on Soil Organic Matter Maintenance

Cellulosic biofuel production may generate new markets and revenue for farmers. However, residue removal may cause environmental problems such as soil erosion and soil organic matter (SOM) loss. The objective of this study was to determine the amounts of residue necessary for SOM maintenance under different tillage and residue removal scenarios for corn–soybean [ L. – (L.) Merr. ] and continuous corn rotations for a site in west-central Minnesota. We employed a process-based model (CQESTR) to evaluate management practices and quantify SOM changes over time. Results showed that conventional tillage resulted in SOM loss regardless of the amount of residue returned. Under no-till, residue amount was important in determining SOM accumulation or depletion. For the upper 30 cm of soil, average annual rates of 3.65 and 2.25 Mg crop residue ha yr were sufficient to maintain SOM for corn–soybean and continuous corn rotations, respectively. Soil OM in soil layers below 30 cm was predicted to decrease in all scenarios as a result of low root inputs. When considered over the upper 60 cm (maximum soil depth sampled), only continuous corn with no-till was sufficient to maintain SOM. Results from this work are important because they show that, for these management scenarios, no-till management is necessary for SOM maintenance and that determining whether SOM is accumulating or declining depends on the soil depth considered. At current yields observed in this study area, only continuous corn with no-till may generate enough residue to maintain or increase SOM.
Biosphere/atmosphere CO2 exchange in tundra ecosystems - Community characteristics and relationships with multispectral surface reflectance

The spatial and temporal patterns of many of the factors controlling CO2 exchange are related to characteristics of the vegetated surface which can potentially be monitored using multispectral remote sensors. Realization of this potential depends, in part, on an improved understanding of ecosystem processes and their relationship to variables which are accessible to remote sensing techniques. We examined these relationships using portable, climate-controlled, instrumented enclosures to measure CO2 exchange rates in selected tundra sites near Bethel, Alaska. Rates were related to vegetation community type and climatic variables. Exchange rates in enclosures were compared to exchange measurements obtained by eddy correlation on a 12-m micrometeorological tower. For an average light input of 37 einsteins/day during 20 midsummer days, the empirically modeled exchange rate for a representative area of vegetated tundra was 1.2 ±1.1 (95% confidence interval) g CO2 m−2 d−1. This was comparable to a tower measured exchange over the same time period of 1.1 ±1.1 (95% confidence interval) g CO2 m−2 d−1. Net exchange in response to varying light levels was compared for two major community types, wet meadow and dry upland tundra, and to the net exchange measured by the micrometeorological tower technique. Portable radiometers were used to measure the multispectral reflectance properties of the sites. These properties were then related to exchange rates with the goal of providing a quantitative foundation for the use of satellite remote sensing to monitor biosphere/atmosphere CO2 exchange in the tundra biome. The Normalized Difference Vegetation Index (NDVI) and the near-infrared/red reflectance ratio (SR) computed from surface reflectance were strongly correlated with net CO2 exchange for both upland and wet meadow vegetation. However, the form of the relationship was distinct from measured correlations in other ecosystems, suggesting that global surveys may require adjustment for geographical differences in exchange processes.
Development and Verification of JAZZ1D: A Stream Temperature Model

The Advection-Diffusion-Reaction equation is solved, applying the finite volume method, using high order discretisation schemes and flux limiting strategies that eliminate the false difusion and avoid spurious oscillations in the numerical solution. The algorithm is verified through benchmark tests with known exact solution, namely the cases of pure advection and pure diffusion, obtaining accurate results. A model for computation of the spatio-temporal distribution of the stream temperature in a 194 km long reach of the Biobio River, located in the Region del Biobio of Chile, is elaborated. The study area includes from Rucalhue in the Andean chain at an elevation of 245 m to the river mouth in the Pacific Ocean. In the model, a detailed digital elevation model (DEM) of the river is used. Detailed hydrometeorologic records are taken from three measurement stations administrated by the National Water Agency, Direccion General de Aguas. For computation of the heat exchange between the stream water and the atmosphere, meteorological records obtained from four measuring stations are used, and an adequate spatially-distributed meteorological-database is elaborated. The instantaneous temperature distribution in the study reach is computed for the year 2003. The performance of the model is evaluated comparing the computations with detailed measurements of water temperature at the river mouth. Results exhibit the high accuracy of the model in the prediction of the stream temperature along the study reach, and show interesting aspects of river temperature dynamics as the influence of artificial reservoirs intended to hydropower generation
Geodetic aspects of the 19 May 2011 Simav earthquake in Turkey

On 19 May 2011, an earthquake of magnitude Mw:5.9 occurred just 9.1 km below the surface of the earth on the Simav fault in Turkey. The region is located north-west of the Gediz graben, one of the major tectonic structures in the extensional regime of western Anatolia. In this study, from 2009 to 2011, the data from nine Continuously Operating Reference Stations (CORS-TR) in the region and one permanent Global Navigation Satellite System station working locally were assessed and analysed using GAMIT/GLOBK software. The behaviour of these stations before and after the earthquake was analysed using calculated time series. At the same time, the strain and rotation rates of current deformation in the Simav region were computed using the 2008–2011 data from the CORS-TR network. The directions obtained from the focal mechanism solutions and strain analysis of the Simav earthquake were observed as being in harmony. Nonetheless, Simav earthquake caused a displacement of 1–2 mm (approximately) in nearby locations. The Simav earthquake shows that the extensional regime in western Anatolia has recently been active in the region and is a good example of the evolution of the graben system.
Diversification strategies for sustaining small-scale fisheries activity: A multidimensional integrated approach

The paper suggests that the diverse livelihoods could properly be taken into account to endeavour the effort for more sustainable, flexible and adaptive small-scale fisheries. Diversification contributes to increase income and well-being, thereby providing an adaptive model that is consistent with the concepts of empowerment and social inclusion. Strategies embedded in the regional/local situation could provide results in order to involve individuals, and groups of actors and stakeholders in a decision making process based on an operational approach. The study described in this article is aimed at encouraging and strengthening the diversification activities of small-scale fisheries in the Ionian coastal area of Sicily. The cognitive maps and the AHP method have been used to work with groups of actors, experts and stakeholders active in the local coastal area through a structured and personalized process aimed at creating a shared visions of strategic actions directed to the policy makers.
Numerical simulation of recurrence of asperity rupture in the Sanriku region, northeastern Japan

[1] A numerical simulation study is presented for the recurrence of great earthquakes and aseismic sliding in the Sanriku region, northeastern Japan, where the Pacific Plate subducts beneath northern Honshu and M8 class earthquakes have occurred approximately every 100 years. The friction on the plate interface is assumed to obey a rate- and state-dependent friction law, and the spatial distribution of constitutive parameters of the friction law is estimated, so that the simulated slip histories mimic those estimated from seismic and geodetic observations. By introducing two large asperities that have velocity-weakening frictional properties, earthquakes similar to the 1968 Tokachi-oki earthquake (Mw = 8.2) and the 1994 Sanriku-oki earthquake (Mw = 7.7) can be modeled. The former broke both the large asperities, and the latter broke one of them. The ruptures of the two simulated large earthquakes started from almost the same location, and their nucleation processes are similar to each other. Two smaller asperities were introduced to represent smaller earthquakes. One of the small asperities is for the largest aftershock (Mw = 6.9) of the 1994 Sanriku-oki earthquake, which was located westward from the 1994 main shock area and took place 10 d after the main shock. The present simulation suggests that the largest aftershock was triggered by stress caused by propagation of postseismic sliding. In the simulation, the area of greatest intensity of postseismic sliding is located in the region between the main shock slip area and the largest aftershock area, which is consistent with the estimation from GPS data analyses for the postseismic sliding of the 1994 Sanriku-oki earthquake. Some important characteristics of seismic and aseismic processes, as estimated from observations, are reproduced in the model. This suggests that spatially nonuniform frictional properties on the plate interface can be estimated to some extent by comparison between model results and observed data.
An airborne study of air quality around the Hong Kong Territory

An airborne study of air quality was made around the Hong Kong Territory during October and November of 1994. The air quality measurements included NO, NO y , O 3 , CO, SO 2 , condensation nuclei, black carbon, aerosol light scattering, and aerosol particle size and number. Complex wind patterns are present, mixing the emissions from Hong Kong with aged pollution transported into the region from the People's Republic of China. This leads to poor air quality on the west and north sides of the Hong Kong Territory. CO mixing ratios were 200-800 parts per billion by volume (ppbv), and black carbon was present in the range of 5-7 μg/m 3 . Ozone mixing ratios of 100-120 ppbv were typical. The CO/NO y ratio in the heavily polluted region was 10, similar to the CO/NO y emission ratio for pollution emitted from the People's Republic of China immediately upwind of Hong Kong.
The GLOWA Volta Project: Interdisciplinary analysis of the impact of global change on a river basin in West Africa

Abstract This article gives an overview of the structure of the interdisciplinary GLOWA Volta Project and its main scientific outputs. The article serves to provide the context for a set of articles written by project scientists for this special issue of the Journal of River Basin Management. After a brief introduction, a description is given of the Volta Basin in West Africa. The main issues related to changes in water supply and demand are presented. Climate change and variability, landuse change, and increasing competition for water between sectors are especially relevant. The integrative approach followed within the GLOWA Volta Project is given in detail. The choice was made to focus on conceptual integration early on, rather than at the end of the project. This led to a network structure for communication between disciplinary research modules. Finally, a listing of the individual articles in the special section is given, together with overall conclusions.
A comparison of radio-echo sounding data and electrical conductivity of the GRIP ice core

Abstract The depth of reflecting layers in Arctic ice sheets has been determined by electromagnetic echo sounding, using a varying distance between transmitter and receiver to determine the radar wave velocity. The depth of the radar reflecting layers is compared with a profile of electrical conductivity measurements (ECMs) from the Greenland Ice Core Project (GRIP) ice core, in order to determine the velocity of the radar waves in the ice cap. By using several reflecting layers, it is possible to isolate the firn correction of the wave velocity and to estimate the accuracy of the calculated electromagnetic wave velocity. The measured firn correction is compared with the correction calculated from the density profile, and a comparison between the depth profiles of ECM and radar based on the corrected electromagnetic wave velocity is presented. This profile shows that acid layers, which originate from major volcanic eruptions, show up as reflecting radar horizons.
Downward transport in the upper stratosphere during the minor warming in February 1979

On February 6, 1979, a small region of dry air, referred to below as a dry tongue, appeared in Limb Infrared Monitor of the Stratosphere data directly below the stratopause at approximately 75°N when a zonal average between 40°E and 160°E was applied. Isentropic analysis of Ertel's potential vorticity and H 2 O mixing ratio does not support the hypothesis of the dry tongue being caused solely by adiabatic sinking from the dry mesosphere into the upper stratosphere. Therefore a three-dimensional mechanistic model of the middle atmosphere, which is mainly driven by the net heating rate and the effects of breaking gravity waves, is used to simulate the minor warming in January and February 1979. The model data clearly support the existence of the dry tongue mentioned above as a real phenomenon. Moreover, they allow the dry tongue to be interpreted as the result of the combined adiabatic and diabatic downward movements east of the center of the polar vortex.
The Arctic climate paradox: The recent decrease of the Arctic Oscillation

A current paradox is that many physical and biological indicators of Arctic change—summer sea‐ice extent, spring surface air temperature and cloud cover, and shifts in vegetation and other ecosystems—show nearly linear trends over the previous two and a half decades, while the Arctic Oscillation, a representative atmospheric circulation index often associated with Arctic change, has had a different, more episodic behavior, with a near‐neutral or negative phase for 6 of the last 9 years (1996–2004) following a positive phase (1989–1995). Stratospheric temperature anomalies over the Arctic, which serve as an index of the strength of the polar vortex, also show this episodic character. Model projections of Arctic temperature for 2010–2029 show model‐to‐model and region‐to‐region differences suggesting large variability in the future response of atmospheric circulation to external forcing. Thus internal processes in the western Arctic may have a larger role in shaping the present persistence of Arctic change than has been previously recognized.
Band selection for hyperspectral target detection based on a multinormal mixture anomaly detection algorithm

The paper outlines a new method for band selection derived from a multivariate normal mixture anomaly detection method. The method consists in evaluating detection performance in terms of false alarm rates for all band configurations obtainable from an input image by selecting and combining bands according to selection criteria reflecting sensor physics. We apply the method to a set of hyperspectral images in the visible and near-infrared spectral domain spanning a range of targets, backgrounds and measurement conditions. We find optimum bands, and investigate the feasibility of defining a common band set for a range of scenarios. The results suggest that near optimal performance can be obtained using general configurations with less than 10 bands. This may have implications for the choice of sensor technology in target detection applications. The study is based on images with high spectral and spatial resolution from the HySpex hyperspectral sensor.
ECOLOGICAL CHARACTERIZATION OF SOME SELECTED VASCULAR SPECIES IN THE ARCTIC ENVIRONMENT OF NY-ALESUND, SVALBARD, IN RELATION TO SOIL MOISTURE CONDITIONS

An attempt has been made to characterize and categorize some selected vascular species in the ~~-~lesund area, Svalbard, in relation to soil moisture conditions. A total of sixty releves were established to describe the floristic structures of plant communities. At each releve site, one soil core sample in a 100 ml metal container was collected to determine soil physical properties. Samples were oven-dried for 48 hours at 105OC. Moisture content was measured and soil moisture index was calculated for each releve. Based on the index, sixty releves were divided into five soil moisture classes. Throughout the sixty releves, twenty-five species of vascular plants were recognized. Of them, eleven species were selected for this study. They were Salk polaris, Oxyria digyna, Polygonum viviparum, Cerastium arcticum, C. regelii, Saxifraga caespitosa, S. cernua, S. nivalis, S. oppositifolia, Dryas octopetala, and Cassiope tetragona. These were the species that occurred in more than eleven releves out of the sixty. Their frequencies against the soil moisture classes were counted. Ecological distribu- tion curves were constructed for the species. From the distribution pattern, especially the amplitude and the mode position on the moisture classes, the species were classified into six categories as follows, Le. , euryhygrotopic xerophyte, euryhygrotopic mesophyte, euryhygrotopic hygrophyte, stenohygrotopic xero- phyte, stenohygrotopic mesophyte, and stenohygrotopic hygrophyte.
Three‐dimensional structure of storm‐generated currents

Previous studies of wind-driven currents have naturally concentrated on the prediction of destructive storm surges. However, the present and planned construction of large facilities in offshore waters makes study of the currents themselves equally important. Here we show that it is possible to model three-dimensional time-dependent currents by numerical integration over a two-dimensional grid followed by an evaluation of convolution integrals over the sea slope and wind stress. Solutions for idealized cases are compared with analytical results, and a study of a hurricane in the Gulf of Mexico is presented.