Miracle-dz/UniFAR-FTUs huggingface dataset:
2D–2D Nanoheterostructure of an Exposed {001}-Facet CuO and MoS2 Based Bifunctional Catalyst Showing Excellent Surface Chemistry and Conductivity for Cathodic CO2 Reduction

A novel CuO-MoS2 based heterostructure catalyst model system is proposed where a CuO nanosheet with exposed {001} facet with proper termination is the active surface for the catalysis and a MoS2 nanosheet is the supporting layer. Density functional theory (DFT) calculations were performed to validate the model. The MoS2 bilayer forms a stable heterostructure with {001} faceted CuO with different terminations exposing oxygen and copper atoms (active sites) on the surface. The heterostructure active sites with a low oxidation state of the copper atoms and subsurface oxygen atoms provide a suitable chemical environment for the selective production of multicarbon products from CO2 electrocatalytic reduction. Furthermore, our heterostructure model exhibits good electrical conductivity, efficient electron transport to active surface sites, and less interfacial resistance compared to similar heterostructure systems. Additionally, we propose a photoenhanced electrocatalysis mechanism due to the photoactive nature of MoS2. We suggest that the photogenerated carrier separation occurs because of the interface-induced dipole. Moreover, we utilized a machine learning model trained on a 2D DFT materials database to predict selected properties and compared them with the DFT results. Overall, our study provides insights into the structure–property relationship of a MoS2 supported 2D CuO nanosheet based bifunctional catalyst and highlights the advantages of heterostructure formation with selective morphology and properly terminated surface in tuning the catalytic performance of nanocomposite materials.
Linearized seismic waveform inversion using a multiple re‐weighted least‐squares method with QR preconditioning

Linearized inversion methods such as Gauss‐Newton and multiple re‐weighted least‐squares are iterative processes in which an update in the current model is computed as a function of data misfit and the gradient of data with respect to model parameters. The main advantage of those methods is their ability to refine the model parameters although they have a high computational cost for seismic inversion. In the Gauss‐Newton method a system of equations, corresponding to the sensitivity matrix, is solved in the least‐squares sense at each iteration, while in the multiple re‐weighted least‐squares method many systems are solved using the same sensitivity matrix. The sensitivity matrix arising from these methods is usually not sparse, thus limiting the use of standard preconditioners in the solution of the linearized systems. For reduction of the computational cost of the linearized inversion methods, we propose the use of preconditioners based on a partial orthogonalization of the columns of the sensitivity matrix. The new approach collapses a band of co‐diagonals of the normal equations matrix into the main diagonal, being equivalent to computing the least‐squares solution starting from a partial solution of the linear system. The preconditioning is driven by a bandwidth L which can be interpreted as the distance for which the correlation between model parameters is relevant. To illustrate the benefit of the proposed approach to the reduction of the computational cost of the inversion we apply the multiple re‐weighted least‐squares method to the 2D acoustic seismic waveform inversion problem. We verify the reduction in the number of iterations in the conjugate'gradient algorithm as the bandwidth of the preconditioners increases. This effect reduces the total computational cost of inversion as well.
ATHENS UNIVERSITY OF ECONOMICS AND BUSINESS PROGRAMME OF POSTGRADUATE STUDIES IN COMPUTER SCIENCE

During the last years, the popularity of microblogging and social media services such as Twitter has increased significantly. Lots of users often use these services to express feelings or opinions about a variety of subjects. The analysis of this kind of content can extract useful information for fields such as personalized marketing or social profiling. In addition, it can help consumers decide whether to buy or not a certain product. However such a task is not trivial, because the language used in Social media is often informal presenting new challenges to text analysis. In this thesis we describe a system that was developed to detect sentiment in microblogging content such as Tweets or SMS messages in English. Our system has competed in two international challenges and has achieved very good results. We also apply our methodology to create a system for Greek. Finally, we propose ideas for future work.
Association of extreme precipitation over the Yangtze River Basin with global air–sea heat fluxes and moisture transport

Although the effect of sea surface temperature anomalies in the Pacific and Indian Oceans on precipitation over the Yangtze River Basin (YRB) is well known, the impact of air–sea sensible and latent heat fluxes (SHF and LHF) has not been well studied. Based on the statistical and diagnostic analyses of historical precipitation data over the YRB, SHF and LHF over the global ocean, as well as global atmospheric reanalysis data, the impacts of SHF and LHF in the selected ocean regions on YRB extreme precipitation were investigated. The spatial distributions of the correlation coefficients between the YRB extreme precipitation indices (YRB‐EPI) and SHF and LHF over the global ocean were analysed to identify critical air–sea interaction regions affecting YRB extreme precipitation. Results show that a significant positive correlation exists between YRB‐EPI and air–sea heat fluxes over the Northwest Indian Ocean, Southeast Indian Ocean, Southwest Indian Ocean and South China Sea regions. Negative correlations were found over Central Equatorial Pacific, while positive lagged correlations exist over East Pacific. Composite analyses of global wind, geo‐potential height and water vapour transport were also conducted for ten heaviest and ten lightest YRB precipitation years, respectively. In heavy YRB precipitation years, the atmospheric circulation pattern is generally characterized by a strengthened Western Pacific Subtropical High (WPSH) extending northwestward, a strengthened lower tropospheric convergence zone over the YRB, three distinct moisture transport paths from adjacent oceans to the YRB and low‐level mid‐latitude northerly wind anomalies. Whereas, in light YRB precipitation years, it is dominated by the southwesterly summer monsoon over the YRB, with a convergence zone displaced to the north of the YRB, a weak WPSH, and only two main paths of moisture transport. These distinctions between the heavy and light YRB precipitation years provide a physical basis for establishing a statistical prediction model for YRB extreme precipitation.
High-resolution soil moisture mapping by a proximal ground penetrating radar : a numerical, laboratory and field evaluation

Soil moisture is an important state variable acting in many environmental, hydrologic and climatic processes. There is thus a pressing scientific demand for revealing the soil moisture dynamics in the biosphere at various temporal and spatial scales. Despite the huge development of remote sensing of soil moisture techniques, there is still a lack of soil moisture measurement techniques available at high spatial resolution (~ m). This thesis aimed to validate and apply advanced proximal ground penetrating radar (GPR) for soil moisture sensing at the field scale. For field acquisition, the GPR system was mounted on a mobile platform that allowed for a fast acquisition rate at high resolution. The impact of shallow soil layering on the GPR backscattered signal was investigated in numerical and laboratory experiments and the best GPR data inversions strategies for dealing with shallow soil layering were determined. Then, coherent two-layered and continuous soil moisture profiles could be characterized in field conditions, owing to the large frequency bandwidth in which the GPR operates. The uncertainties in soil moisture sensing and mapping were comprehensively evaluated in field conditions, and the proposed GPR method appeared to be highly precise and accurate. In that respect, the GPR method showed a high repeatability for soil moisture sensing. This advanced GPR method permitted to characterize the spatiotemporal patterns of soil moisture in an agricultural field and to investigate their temporal stability. Locations showing temporal stability of field-average soil moisture could be revealed. Lastly, the effect of the spatial variability of antecedent soil moisture on the runoff response using a distributed hydrologic model was studied in various field and moisture conditions. Benefiting from an unprecedented spatial resolution, the proposed GPR method bridges the scale gap between large-scale remote sensing instruments and small-scale invasive sensors for an accurate soil moisture determination.
Hydrogen and oxygen isotopic compositions of water vapor over the Bay of Bengal during monsoon

δDv and δ18Ov of ~70 water vapor samples collected at 6 and 25 m above sea level over the Bay of Bengal (BoB) during July–August 2012 are reported. This helps characterize the isotopic signature of monsoon vapor. No significant vertical variation is observed in δDv, δ18Ov, or deuterium excess (defined as δD–8δ18O); δDv and δ18Ov are significantly correlated (r = 0.92) at each height; the deuterium excess values do not, because the variation of δDv and δ18Ov relative to their uncertainties is much larger than that of the latter. The temporal variations of δDv and δ18Ov correlate well with air temperature rather than sea surface temperature. The control of normalized humidity on deuterium excess is less prominent. While the distribution of water vapor isotopologues over the BoB is primarily determined by the ocean surface conditions, they are significantly altered by laterally advected vapor from rain en route during the monsoon.
Understanding the local pedological and ecological impacts of dust emitted from Cowal Gold Mine.

The production of airborne particulates is a corollary of open-cut mining operations. Despite the best efforts of mine managers to minimise dispersal of these particulates, quantities of dust are inevitably carried beyond the mine margins and deposited in the surrounding landscape. Micromorphological and granulometric techniques were used to identify and subsequently isolate a likely aeolian component from the topsoils surrounding Cowal Gold Mine (CGM), in the Central West of New South Wales. Topsoil and subsoil samples were taken in four transects extending 12 km from the mine bund. An assessment of the geochemical properties of these samples will reveal the extent of contemporary aeolian deposition, and identify any trend consistent with CGM acting as a point source. In an effort to assess the likely ecological role of any mine dust accumulation, barley grass and rye grass were sampled along transects extending from the mine bund, and analysed for total metal concentration. Preliminary data infers that for a number of metals including lanthanum, molybdenum, lead and strontium, there is attenuation in plant uptake with increasing distance from CGM. A correlation of plant and soil data will extricate local soil factors and clarify the current role of mine-related dust, and the likely impacts of future accumulation of this dust.
Field‐scale model for the natural attenuation of uranium at the Hanford 300 Area using high‐performance computing

High‐resolution, three‐dimensional, reactive flow and transport simulations are carried out to describe the migration of hexavalent uranium [U(VI)] at the Hanford 300 Area bordering the Columbia River and to better understand the persistence of the uranium plume at the site. The computer code PFLOTRAN developed under a DOE SciDAC‐2 project is employed in the simulations that are executed on ORNL's Cray XT4/XT5 supercomputer Jaguar. The conceptual model used in the simulations is based on the recognition of three distinct phases or time periods in the evolution of the U(VI) plume. These correspond to (1) initial waste emplacement; (2) initial presence of both labile and nonlabile U(VI) with an evolved U(VI) plume extending from the source region to the river boundary, representing present‐day conditions; and (3) the complete removal of all nonlabile U(VI) and labile U(VI) in the vadose zone. This work focuses primarily on modeling Phase II using equilibrium and multirate sorption models for labile U(VI) and a continuous source release of nonlabile U(VI) in the South Process Pond through dissolution of metatorbernite as a surrogate mineral. For this case, rapid fluctuations in the Columbia River stage combined with the slow release of nonlabile U(VI) from contaminated sediment are found to play a predominant role in determining the migration behavior of U(VI) with sorption only a second‐order effect. Nevertheless, a multirate model was essential in explaining breakthrough curves obtained from laboratory column experiments using the same sediment and is demonstrated to be important in Phase III. The calculations demonstrate that U(VI) is discharged to the river at a highly fluctuating rate in a ratchet‐like behavior as the river stage rises and falls. The high‐frequency fluctuations must be resolved in the model to calculate the flux of U(VI) at the river boundary. By time averaging the instantaneous flux to average out noise superimposed on the river stage fluctuations, the cumulative U(VI) flux to the river is found to increase approximately linearly with time. The flow rate and U(VI) flux are highly sensitive to the conductance boundary condition that describes the river‐sediment interface. By adjusting the conductance coefficient to give a better match to the measured piezometric head, good agreement was obtained with field studies for both the mean flux of water of 109 kg/yr and U(VI) of 25 kg/yr at the river‐aquifer boundary for a computational domain encompassing the South Process Pond. Finally, it is demonstrated that, through global mass conservation, the U(VI) leach rate from the source region is related to the U(VI) flux at the river boundary.
'McGeneration'? An examination of the continuing importance of place in cultural regeneration

The regeneration of urban places is a major force in the landscape of previously declining industrial cities. The processes and policies of regeneration have received considerable research over the years, with a particular emphasis on quantitative indicators to capture large-scale effects. One major change has been the rising role of culture within regeneration. In this thesis, a closer, qualitative view is taken to investigating urban regeneration, to uncover a narrative of two particular and related concerns within cultural urban regeneration. On the one hand, the risks of homogenisation as standardised practices are transferred globally; on the other, the demand for distinctiveness, and for regenerated areas to demonstrate unique and appealing characteristics to mediate global processes, and attract inward investment of economic, social, and human capital. The thesis focuses on the iconic space of the waterfront, and studies three major regenerating cities in the United Kingdom, studying the dynamics of culture, homogenisation, and distinctiveness. From an initial synthesis of theories, a thematic framework is constructed. The thesis then captures the understanding of those themes as articulated by forty-seven elite actors who work within cultural regeneration in the three case study waterfronts, exposing the continuing impact of place in the face of homogenising forces.
Understanding Amazonian fluvial rias based on a Late Pleistocene–Holocene analog

Fluvial rias are elongated lakes at tributary mouths that can reach dozens of kilometers in length, constituting one of the most remarkable features in the Amazonian landscape. Thus far, definitive data which documents the genesis of fluvial rias have not been published. The main goal of this work was to integrate morphological, sedimentological and chronological information in order to characterize fluvial paleorias in the interfluve of the Purus and Madeira Rivers and discuss the most likely hypothesis for their genesis. These paleorias were first observed through remote sensing imagery as several elongated and interconnecting belts of open vegetation that are in sharp contact with the surrounding dense forest. The belts are branched and form a dendritic pattern similar to many modern drainage networks. The sedimentary record of these belts revealed the prevalence of sharp‐based sandstones and mudstones arranged into fining‐upward successions, which are compatible with deposition within channels. Active channel and abandoned channel deposits were recognized. These are topped by continuous mudstones related to rapid channel abandonment and formation of a low energy basin or ria environment. Radiocarbon dating of these deposits recorded only Late Pleistocene and Holocene ages ranging from 21 547–22 285 cal yr bp to 5928–6124 cal yr bp. This chronology for sediment deposition is not compatible with the hypothesis of Amazonian rias being formed by fluvial erosion during the Last Glaciation Maximum low sea level, with sediment accumulation during the subsequent Holocene transgression. Instead, the studied paleorias record previous tributaries of the Madeira River that became abandoned as the position of this river shifted southeastward and its interfluve tilted northward, inverting the drainage systems. Therefore, a neotectonic origin of some Amazonian paleorias seems most likely. This hypothesis should be considered in further investigations aiming at understanding the origin of numerous modern fluvial rias that typify the Amazonian landscape. Copyright © 2014 John Wiley & Sons, Ltd.
Channel–floodplain connectivity during an extreme flood event: implications for sediment erosion, deposition, and delivery

The term connectivity has emerged as a powerful concept in hydrology and geomorphology and is emerging as an innovative component of catchment erosion modeling studies. However, considerable confusion remains regarding its definition and quantification, especially as it relates to fluvial systems. This confusion is exacerbated by a lack of detailed case studies and by the tendency to treat water and sediment separately. Extreme flood events provide a useful framework to assess variability in connectivity, particularly the connection between channels and floodplains. The catastrophic flood of January 2011 in the Lockyer valley, southeast Queensland, Australia provides an opportunity to examine this dimension in some detail and to determine how these dynamics operate under high flow regimes. High resolution aerial photographs and multi‐temporal LiDAR digital elevation models (DEMs), coupled with hydrological modeling, are used to assess both the nature of hydrologic and sedimentological connectivity and their dominant controls. Longitudinal variations in flood inundation extent led to the identification of nine reaches which displayed varying channel–floodplain connectivity. The major control on connectivity was significant non‐linear changes in channel capacity due to the presence of notable macrochannels which contained a > 3000 average recurrence interval (ARI) event at mid‐catchment locations. The spatial pattern of hydrological connectivity was not straight‐forward in spite of bankfull discharges for selected reaches exceeding 5600 m3 s–1. Data indicate that the main channel boundary was the dominant source of sediment while the floodplains, where inundated, were the dominant sinks. Spatial variability in channel–floodplain hydrological connectivity leads to dis‐connectivity in the downstream transfer of sediments between reaches and affected sediment storage on adjacent floodplains. Consideration of such variability for even the most extreme flood events, highlights the need to carefully consider non‐linear changes in key variables such as channel capacity and flood conveyance in the development of a quantitative ‘connectivity index’. Copyright © 2013 John Wiley & Sons, Ltd.
The Role of Aerosols in Convective Processes during the Midsummer Drought in the Caribbean

Saharan dust (SD) heavily impacts convective precipitation in the Caribbean. To better understand the role of SD in precipitation development during the midsummer drought (MSD), an observational campaign, centered at the city of Mayaguez, Puerto Rico (18.21 N, 67.13 W), between 3 June and 15 July 2014, was conducted in order to select a range of atmospheric conditions to be simulated using the Regional Atmospheric Modeling System (RAMS) cloud resolving model under “no SD” and “SD” conditions. The events included one dry day with moderate-heavy SD, one localized moderate rainfall event with moderate SD, one island-wide light precipitation event with heavy SD, and one island-wide heavy precipitation event with light-moderate SD. Model results show that (1) precipitation results are improved when compared with observation with the presence of SD, (2) precipitation, cloud fraction, dew point temperatures, and humidity are significantly reduced under SD conditions, (3) precipitation can occur when SD is removed for a dry day, (4) there is evidence of rain being delayed due to the presence of SD without rainfall intensity or accumulation increases, (5) liquid mixing ratio increases of up to 1.4 g kg−1 occur in the absence of SD, and (6) vertical wind increases of up to 0.8 m s−1 occur in the absence of SD.
Correlative Relationships Between Carbon- and Oxygen-Isotope Records in Two Cool-Temperate Brachiopod Species off Otsuchi Bay, Northeastern Japan

Abstract. We present high-resolution, three-dimensional carbon (&dgr;13C)- and oxygen (&dgr;O)-isotope compositions from calcite shells of two modern brachiopod species (Terebratulina crossei and Terebratalia coreanica) and their correlative relationships. &dgr;13C and &dgr;18O values from the secondary shell layer, which constitutes the main body of a brachiopod shell, are in and/or out of the range of &dgr;13C and &dgr;18O values of calcite precipitated in isotopic equilibrium with ambient seawater (equilibrium calcite). The &dgr;C and &dgr;18O values of samples from the outermost part of the secondary shell layer show positive correlations. The values of high-growth-rate portions are less than those of low-growth-rate portions; these results are ascribed to a kinetic isotope fractionation effect. Metabolic influences are identified in the isotopic compositions of the low-growth-rate portions for T. coreanica, resulting in decreases in &dgr;13C values compared with those of equilibrium calcite. We illustrate the effects of kinetic isotope fractionation and metabolism on the isotopic compositions of brachiopod shell calcite, which vary among shell portions within a single shell, as well as between the two species. However, appropriate selection of brachiopod taxa and shell portions that reflect the isotopic composition of ambient seawater enables their use as a reliable paleoenvironmental proxy.
Operating a Sensor Network at 3500 m Above Sea Level

Jan Beutel, Stephan Gruber†, Andreas Hasler†, Roman Lim, Andreas Meier, Christian Plesslo, Igor Talzi‡, Lothar Thiele, Christian Tschudin‡, Matthias Woehrle, Mustafa Yuecel Computer Engineering and Networks Lab, ETH Zurich, Zurich, Switzerland †Physical Geography Division, Department of Geography, University of Zurich, Switzerland oPaderborn Center for Parallel Computing, University of Paderborn, Germany ‡Computer Science Department, University of Basel, Switzerland