Miracle-dz/UniFAR-FTUs huggingface dataset:
The hydrodynamic instability of water drops falling at terminal velocity in vertical electric fields

A study has been made of the onset of instability and corona in water drops of raindrop size falling at their terminal velocity in a vertical wind tunnel at atmospheric pressure and exposed to vertical electric fields. The overall behavior at initial instability is similar for charged and uncharged water drops of all sizes in fields of both polarities, either pulsed or slowly varying, and even for uncharged drops of the low-surface-tension liquids, acetone and ethyl alcohol. Instability proceeds by the formation of a ‘point’ at the upper surface of the drop from which electrical corona is emitted, changing the net charge on the drop. Contrary to the findings of previous investigators, no mass-loss is observed at instability; charge-loss is by corona even at atmospheric pressure. Typical charging of an initially uncharged 2-mm-radius water drop at instability is 5×10−10 coul; the charge-loss of an initially charged ( ≈1.5×10−9 coul) drop is typically 2×10−9 coul. For large uncharged water drops (radii >2 mm) the field necessary for instability is higher than that given by the criterion of Taylor (1964) and is essentially independent of radius at about 9.5 kv cm−1. For large highly charged drops the instability field is typically 5.5 kv cm−1. It is suggested that some of the more unexpected results are a consequence of the aerodynamic pressures on the drops.
FLOW REVERSALS IN PEATLANDS INFLUENCED BY LOCAL GROUNDWATER SYSTEMS

Piezometric head data from various depths were examined at two peatlands in Ontario, Canada and one peatland in Sweden influenced by small-scale, shallow groundwater systems. Data from different hydrogeological settings show reversals in groundwater flow leading to discharge in topographically high regions of peatlands in isolation from large-scale groundwater flow. It is suggested that subsurface flow within peat can reverse in direction in response to water deficit and water-table drawdown. The data presented here refute the assumption that local groundwater flow in peatlands is unidirectional and further illustrate the fact that measurable subsurface water flow can occur at depth in peat isolated from large-scale groundwater flow systems. In the light of implicit assumptions made by many workers on water movement in peatlands, especially when connected to small-scale groundwater systems, the consequences of such reversals are paramount in understanding the hydrology and biogeochemistry of peatlands. © 1997 by John Wiley & Sons, Ltd.
Effect of Penetration Rate on Cone Penetration Resistance in Saturated Clayey Soils

In this paper, the effects of penetration rate on cone resistance in saturated clayey soils are investigated. Shear strength rate effects in clayey soils are related to two physical processes: the increase of shear strength with increasing rate of loading and the increase of shear strength as the process transitions from undrained to drained. Special focus is placed on this second effect. Cone penetration tests were performed at various penetration rates both in the field and in a calibration chamber, and the resulting data were analyzed. The field cone penetration tests were performed at two test sites with fairly homogeneous clayey silt and silty clay layers located below the groundwater table. Additionally, tests with both cone and flat-tip penetrometers in sand-clay mixtures were performed in a calibration chamber to investigate the change in drainage conditions from undrained to partially drained and from partially drained to fully drained. A series of flexible-wall permeameter tests were conducted in the laboratory for various clayey sand mixtures prepared at various mixing ratios in order to obtain values of the coefficient of consolidation, which is required to estimate the penetration rates below which penetration is drained and above which penetration is undrained. A correlation between cone resistance and drainage conditions was established based on the results of the calibration chamber and field penetration tests.
Development of solidification technology for fluorine contaminated Bassanite using Portland blast-furnace (B) cement

廃石膏ボードは，排出プロセスの違いから「製造時廃材」，「新築時廃材」，「解体時廃材」の3つに区分することができ，その発生量は2007年度で150万トンに上っている。 半水石膏は，廃石膏ボードから得られる二水石膏を130°C以上に加熱することにより生産され，水を加えると固まる性質を有していることから，ヘドロの堆積や軟弱粘性土などの地盤改良材としての利用が期待されている。 しかしながら，石膏に含まれているフッ素の溶出量が土壌の環境基準をオーバーする場合があることから，半水石膏の適用に関してはフッ素の溶出や流出を物理的および化学的に抑制させる研究が必要不可欠である。 そこで本研究では，フッ素の溶出を抑制するため，高炉セメントB種による半水石膏のフッ素不溶化技術を開発した。 この結果，土壌の安定処理材として高炉セメントB種を5%程度添加することによって今回対象とした半水石膏添加率の範囲では石膏からのフッ素溶出濃度は養生期間とともに減少し，土壌の環境基準をクリアーする結果を得た。
Near‐surface thermal gradients and mid‐IR emission spectra: A new model including scattering and application to real data

We model the radiative and conductive heat transfer in the top few millimeters of a particulate medium in order to investigate near-surface thermal gradients and their effects on mid-IR emission spectra for different planetary environments. The model extends our previous work by including scattering in the radiative heat transfer. Our results show that significant thermal gradients will form in the top few hundred microns of particulate materials on the surfaces of the Moon and Mercury. Their presence alters spectral contrast and creates emission maxima in the transparent regions of the spectra. The results also show that thermal gradients cause the wavelength position of the Christiansen emission peak to shift by as much as 0.5 μm with variations in thermal conductivity and grain size, in agreement with previous laboratory investigations. These wavelength shifts are due to increased emission in the transparent regions of the spectrum which are superimposed upon the emissivity signature. The results are applied to telescopic spectra of the surfaces of the Moon and Mercury and can account for certain features seen in these data. Additional calculations show that thermal gradients will be minor on the surface of Mars and negligible for Earth.
Post-bleaching recovery of transplanted coral nubbins in Abu Al Abyad Island of Abu Dhabi, United Arab Emirates

The catastrophic bleaching phenomenon is being noticed in several parts of the world since April 2010. Even though the Gulf water corals are accustomed to higher temperature and salinity fluctuations, they are also prone to extreme temperature anomaly (Riegl, 2003). This evidences the recent global mass bleaching and its influence on the Scleractinian corals of Abu Al Abyad Island of Abu Dhabi (United Arab Emirates). The coral reef strength of Abu Al Abyad has significantly reduced after 1998 and 2002 bleaching phenomena (Thabit, 2002). Coral propagation study has been already initiated to restore the coral reefs in the vicinity of this island. After the global alarming of this mass bleaching, the Scleractinian corals of this island are monitored for bleaching event since April, 2010. Eventually, the bleaching symptom was initially observed in the transplanted corals Acropora arabensis in the mid of July. The rightmost nubbin of the table was taken as a reference for the recovery study (Fig. 1). The temperature logger data revealed that, the water temperature has risen up to the maximum of 37°C in the month of July. However Zooxanthellae were expelled, the corals were noticed with active polyps in the study site. The selected nubbin was revisited at once in two months to observe the recovery pattern. The Zooxanthellae were initially reassembled at the base of the nubbin and gradually progressed towards the apex. Post-bleaching recovery of transplanted coral nubbins in Abu Al Abyad Island of Abu Dhabi, United Arab Emirates
A biologically inspired controller to solve the coverage problem in robotics

The coverage problem consists on computing a path or trajectory for a robot to pass over all the points in some free area and has applications ranging from floor cleaning to demining. Coverage is solved as a planning problem—providing theoretical validation of the solution—or through heuristic techniques which rely on experimental validation. Through a combination of theoretical results and simulations, this paper presents a novel solution to the coverage problem that exploits the chaotic behaviour of a simple biologically inspired motion controller, the Braitenberg vehicle 2b. Although chaos has been used for coverage, our approach has much less restrictive assumptions about the environment and can be implemented using on-board sensors. First, we prove theoretically that this vehicle—a well known model of animal tropotaxis—behaves as a charge in an electro-magnetic field. The motion equations can be reduced to a Hamiltonian system, and, therefore the vehicle follows quasi-periodic or chaotic trajectories, which pass arbitrarily close to any point in the work-space, i.e. it solves the coverage problem. Secondly, through a set of extensive simulations, we show that the trajectories cover regions of bounded workspaces, and full coverage is achieved when the perceptual range of the vehicle is short. We compare the performance of this new approach with different types of random motion controllers in the same bounded environments.
Rock glaciers in the patagonian andes: an inventory for the monte san lorenzo (cerro cochrane) massif, 47° s

Abstract Although rock glaciers in the Central and Desert Andes of Argentina and Chile have been previously studied in detail, much less attention has been paid to the occurrence of these permafrost forms in Patagonia. Recently, however, the establishment of the Argentinean Glacier Inventory program, which intends to inventory and monitor all ice masses along the Argentinean Andes, has started a large amount of new geocryological research. The project is designed to provide reliable and worldwide comparable results, supported by well established technical procedures and background information. Presented here is the first rock glacier inventory of the Monte San Lorenzo (Cerro Cochrane) region in the southern Patagonian Andes. A total of 130 intact (9.86 km2) and 47 fossil (1.45 km2) landforms were inventoried using two 2.5 m resolution ALOS Panchromatic Remote‐sensing Instruments for Stereo Mapping images. Since the Argentinean federal initiative described above legally protects all rock glaciers in the country as water reserves, and due to the little scientific knowledge concerning rock glaciers in the vast majority of the Patagonian Andes, this inventory provides an important basis for political decision‐making and opens further geocryological research avenues for the Patagonian region in general.
The impacts of heterogeneous land surface fluxes on the diurnal cycle precipitation: A framework for improving the GCM representation of land‐atmosphere interactions

The present study aims to investigate the modulation of the diurnal cycle precipitation by heterogeneous land surface fluxes. By combining the National Center for Atmospheric Research Community Land Model (CLM) and vector vorticity equation cloud‐resolving model (VVM), experiments are designed to understand the responses of diurnal convection to heterogeneous land surface forcings of various spatial scales and intensities. To delineate the land‐atmosphere interactions, a two‐step off‐line approach is adopted. First, the CLM is driven by observational atmospheric forcing with different characteristic length scales and magnitudes. While the surface fluxes from the CLM show no significant difference in the domain‐averaged values, their spatial distribution responds significantly to the precipitation heterogeneity. In the second step, the derived CLM surface fluxes are used to drive the VVM. Results show that the timing of precipitation accelerates with increasing magnitude of surface flux perturbation, while the mean and diurnal ranges of precipitation roughly remain the same. The larger perturbation magnitude enhances the boundary layer vertical kinetic energy, which advances the development of the boundary layer. On the other hand, the mean and diurnal ranges of precipitation increase significantly, and the timing of initial precipitation delays with increasing perturbation length scale. The inland breeze induced by the large patches of surface fluxes tends to enhance the mesoscale organization of deep convection, hence the stronger precipitation. The present results highlight the importance of taking heterogeneous land surface fluxes into consideration in future development of general circulation model convection parameterizations associated with land and atmosphere interactions.
On the lateral resolution achieved by Kirchhoff migration

I show that the implementation of the Kirchhoff summation migration technique is equivalent to the generation of a synthetic focused array. The focused array theory, which is well developed in underwater acoustics, is used to deal with the factors limiting lateral resolution achieved when carrying out point diffractor imaging by Kirchhoff summation. Lateral resolution of a focused array, defined as the horizontal distance between two identical point diffractors which are just resolvable, is obtained from the width of the array response at the 0.35 amplitude points. The focused array theory approach should help in obtaining more insights into the practical aspects of Kirchhoff summation imaging technique, namely, choice of aperture and spatial sampling interval and the influence of velocity errors and seismic frequency. Examples given show how the lateral resolution can be improved by either increasing the array aperture or by using higher seismic frequency. I use the concept of the depth of focus to demon.
Gravity influenced brittle‐ductile deformation and growth faulting in the lithosphere during collision: Results from laboratory experiments

[1] Because of the competition between brittle and ductile rheologies and their interplay with tectonic and buoyancy forces, lithospheric deformation results in very contrasting styles. In continental collision, especially with unconfined boundaries, deformation can be either homogeneously distributed or localized on complex fault patterns, and different deformation modes such as contraction, extension, and strike-slip interfere. Using scaled lithospheric analog experiments made of dry sand, silicone putties, and dense honey, we investigate the mechanical parameters that control the deformation style in colliding systems, with a particular focus on the roles of buoyancy and brittle-ductile coupling. The analysis of tens of experiments shows that the principal deformation features depend on two main parameters: a brittle-to-ductile strength ratio G, which controls deformation localization at the largest scale, and a buoyancy-to-strength ratio Ar, which fixes the relative amount of contractional, extensional, and strike-slip structures. Strain localization occurs only for G larger than a critical value (� 0.5), and the range of G values, over which the transition from nonlocalized to localized deformation occurs, is small. The three main deformation regimes (contraction, strike-slip, and extension), which coexist in most of the collision experiments, occur in relative proportions that depend mainly on Ar and on the nature of the boundary conditions.
The late Holocene vegetation history of lowland fynbos, Verlorenvlei, southwestern Cape Province, South Africa

The late Quaternary vegetation history of fynbos a sclerophyllous shrubland of the south‐western Cape Province of South Africa, has only recently begun to be revealed by a series of pollen diagrams from mountain sites. Until now, however, a reconstruction of the vegetation history of sites in lowland or coastal fynbos communities has not been possible, principally because of an apparent lack of suitable organic and fossil pollen‐bearing sedimentary material in such environments. The search for appropriate sediments has, however, now revealed a sequence of pollen‐rich deposits in the Verlorenvlei, a coastal lake some 180 km north of Cape Town. The sediments accumulated during the last 5500 years, although the record is not complete as a hiatus in sedimentation is apparent. The sequence has been well radiocarbon dated. This has facilitated a precise reconstruction of the late Holocene vegetation history. The area is today characterised by a mosaic of different fynbos communities and has been much disturbed .
Effectiveness of pneumococcal vaccines in preventing pneumonia in adults, a systematic review and meta-analyses of observational studies

Introduction S. pneumoniae can cause a wide spectrum of diseases, including invasive pneumococcal disease and pneumonia. Two types of pneumococcal vaccines are indicated for use in adults: 23-valent pneumococcal polysaccharide vaccines (PPV23) and a 13-valent pneumococcal conjugate vaccine (PCV13). Objective To systematically review the literature assessing pneumococcal vaccine effectiveness (VE) against community-acquired pneumonia (CAP) in adults among the general population, the immunocompromised and subjects with underlying risk factors in real-world settings. Methods We searched for peer-reviewed observational studies published between 1980 and 2015 in Pubmed, SciELO or LILACS, with pneumococcal VE estimates against CAP, pneumococcal CAP or nonbacteremic pneumococcal CAP. Meta-analyses and meta-regression for VE against CAP requiring hospitalization in the general population was performed. Results 1159 unique articles were retrieved of which 33 were included. No studies evaluating PCV13 effectiveness were found. Wide ranges in PPV23 effectiveness estimates for any-CAP were observed among adults ≥65 years (-143% to 60%). The meta-analyzed VE estimate for any-CAP requiring hospitalization in the general population was 10.2% (95%CI: -12.6; 33.0). The meta-regression indicates that VE against any-CAP requiring hospitalization is significantly lower in studies with a maximum time since vaccination ≥60 months vs. <60 months and in countries with the pediatric PCV vaccine available on the private market. However, these results should be interpreted cautiously due to the high influence of two studies. The VE estimates for pneumococcal CAP hospitalization ranged from 32% (95%CI: -18; 61) to 51% (95%CI: 16; 71) in the general population. Conclusions Wide ranges in PPV23 effectiveness estimates for any-CAP were observed, likely due to a great diversity of study populations, circulation of S. pneumoniae serotypes, coverage of pediatric pneumococcal vaccination, case definition and time since vaccination. Despite some evidence for short-term protection, effectiveness of PPV23 against CAP was not consistent in the general population, the immunocompromised and subjects with underlying risk factors.
Holocene benthic foraminiferal record from a high‐arctic fjord, nordaustlandet, svalbard

Kubischta, F. , Knudsen, K.L. , Ojala, A.E. K. and Salonen, V. ‐P., 2011. Holocene benthic foraminiferal record from a high‐arctic fjord, Nordaustlandet, Svalbard. Geografiska Annaler: Series A, Physical Geography, 93, 227–242. DOI: 10.1111/j.1468‐0459.2011. 00434.x Abstract This study presents the results of benthic foraminiferal analyses of a marine core record from about 100 m water depth in the fjord environment of Isvika bay, Nordaustlandet, Svalbard. During the Last Glacial Maximum, the bay was glaciated by the north‐western sector of the Svalbard‐Barents Sea Ice Sheet. The foraminiferal assemblages reflect glaciomarine conditions during deglaciation and early Holocene (about 11-250–9640 cal. yr bp) followed by glacier‐distal environment in an open fjord with relatively high influence of Atlantic waters from the open ocean (9640–7430-cal. yr bp). A subsequent foraminiferal indication of a glacial advance was followed by deposition of a diamicton unit within a short time period at 5800–5700 cal. yr bp. The mid‐ and late Holocene were characterized by assemblages indicating restricted open‐ocean connection and gradually more severe conditions, which are considered to be caused partly by a gradual cooling and freshening of the Atlantic water inflow to the shelf area and partly by a continuous isostatic uplift of the area. The foraminiferal record shows that the environmental changes in Murchisonfjorden are not just an effect of changes in solar insolation but are also influenced by local processes, as well as changes in the Atlantic water inflow to the northern Svalbard shelf and to the fjord via Hinlopenstretet.
An analysis of large‐scale variations in small‐scale mantle heterogeneity using Global Seismographic Network recordings of precursors to PKP

High-frequency precursors to the core phase PKP are caused by scattering off heterogeneities in the lowermost mantle and D″ regions, and they provide a unique window into the small-scale structure of the deep Earth. We study lower mantle scattering by analyzing 412 high-quality PKP precursor records at ranges between 120° and 137.5° as obtained from the global seismic networks during the last 10 years. To examine regional variations in scattering strength, we compare individual records with the globally averaged PKP precursor stack of Hedlin et al. [1997]. We identify strong differences in apparent scattering strength among specific source-receiver paths. Inversion of these data for scattering source regions is complicated by ambiguity between source- and receiver-side scattering and the sparse and uneven data coverage. Synthetic tests, however, suggest that inversions with applied smoothness constraints can resolve large-scale differences in scattering strength over significant parts of the lower mantle. We use a conjugate gradient method based on an approximation to Rayleigh-Born scattering theory to image differences in the average strength of scattering within the lowermost 1000 km of the mantle. Our results indicate particularly strong scattering beneath central Africa, parts of North America, and just north of India, whereas weaker scattering is seen beneath South and Central America, eastern Europe, and Indonesia. Some regions of strong scattering correlate roughly with large-scale anomalies revealed by seismic tomography including the African plume and the Tethys trench. These correlations are tentative rather than definitive because bootstrap resampling tests show that many details in our model are not reliably resolved and the network data alone do not permit complete resolution of the source-receiver ambiguity in all areas. Further progress in this area will require integration of available network recordings with data collected by regional networks and arrays and consideration of the phase velocity of the precursors as well as their temporal variations.
Bathymetry of the Gulf of Mexico (1)

ABSTRACT The Gulf of Mexico can be divided into two major provinces: a carbonate province to the east and a terrigenous one to the west. The steep side slopes of the Campeche and Florida (Campeche and Florida Escarpments) are not fault scarps, but were formed during the Cretaceous by carbonate deposition along the seaward edge of the subsiding continental block. After the algal banks or reefs that formed the steep side slopes died, sediment progradation and upbuilding formed the shelf and the smooth and gentle upper continental slope. Seaward progradation extended to the top of the escarpments and buried the algal banks. The Continental margin within the terrigenous province between De Soto Canyon and Campeche Canyon was formed by upbuilding and outbuilding. The resulting sedimentary framework has been altered by salt intrusions. The Sigsbee Escarpment at the seaward edge of the sedimentary framework was also formed by salt intrusion. Diapiric structures are not limited to the continental margin, but extend into the center of the Gulf of Mexico basin. Structures in the center of the basin appear to be restricted to the eastern margin of the Sigsbee Abyssal Plain and are aligned in a northeasterly direction. This trend and concentration, if real, may delineate a fracture zone extending from De Soto Canyon to the Golfo de Campeche.