Miracle-dz/UniFAR-FTUs huggingface dataset:
Electrical Anisotropy of Mineralized And Non Mineralized Rocks

Significant electrical resistivity anisotropy, up to 1OO0:1, has been observed in rock samples containing sulphides and samples barren of sulphides. Anisotropy associated with sulphides generally has nsistivity in one direction within the typical ground EM detection limit (less than IO but in the perpendicular directions the resitivity can be well above this limit (100 to 19,000 Such examples have been observed in rocks from Snow Lake (Manitoba), the Bathurst Mining Camp (New Brunswick) and the TransHudson orogen (Saskatchewan). The Snow Lake study was the first of these studies and was carried out to seek an explanation for the weaker than expected electromagnetic (EM) responses of several of tbe sulphide bodies in the region. This continuing study attempts to understand the electrical mechanisms involved in such anisotropic processes in order to provide information for development of improved EM interpretation and survey methods, and of improved EM instrumentation.
Evidence of the influence of the interplanetary magnetic field azimuthal component on polar cusp configuration

A study is presented of the low-altitude polar cusp regions using the precipitating electron data from DMSP F2 and F4 satellites during 54 quasi-simultaneous traversals of the polar cusp region in the same hemisphere. Electron precipitation features are used to determine the cusp morphology and behavior at different magnetic local times for varying orientations of the interplanetary magnetic field (IMF). Indication is found of a systematic shift of the equatorward boundary of the morning cusp region toward the pole (or the equator) in the southern hemisphere for positive (or negative) IMF B{sub y} with respect to its position at noon as detected nearly simultaneously by the other satellite.
Energy of plate tectonics calculation and projection

Abstract. Mathematics and observations suggest that the energy of the geological activities resulting from plate tectonics is equal to the latent heat of melting, calculated at mantle's pressure, of the new ocean crust created at midocean ridges following sea floor spreading. This energy varies with the temperature of ocean floor, which is correlated with surface temperature. The objective of this manuscript is to calculate the force that drives plate tectonics, estimate the energy released, verify the calculations based on experiments and observations, and project the increase of geological activities with surface temperature rise caused by climate change.
Evidence for Low-Grade Metamorphism, Hydrothermal Alteration, and Diagenesis on Mars from Phyllosilicate Mineral Assemblages

The enhanced spatial and spectral resolution provided by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on the Mars Reconnaissance Orbiter (MRO) has led to the discovery of numerous hydrated silicate minerals on Mars, particularly in the ancient, cratered crust comprising the southern highlands. Phases recently identified using visible/near-infrared spectra include: smectite, chlorite, prehnite, high-charge phyllosilicates (illite or muscovite), the zeolite analcime, opaline silica, and serpentine. Some mineral assemblages represent the products of aqueous alteration at elevated temperatures. Geologic occurrences of these mineral assemblages are described using examples from west of the Isidis basin near the Nili Fossae and with reference to differences in implied temperature, fluid composition, and starting materials during alteration. The alteration minerals are not distributed homogeneously. Rather, certain craters host distinctive alteration assemblages: (1) prehnite-chloritesilica, (2) analcime-silica-Fe,Mg-smectite-chlorite, (3) chlorite-illite (muscovite), and (4) serpentine, which furthermore has been found in bedrock units. These assemblages contrast with the prevalence of solely Fe,Mg-smectites in most phyllosilicate-bearing terrains on Mars, and they represent materials altered at depth then exposed by cratering. Of the minerals found to date, prehnite provides the clearest evidence for subsurface, hydrothermal/metamorphic alteration, as it forms only under highly restricted conditions (T = 200–400°C). Multiple mechanisms exist for forming the other individual minerals; however, the most likely formation mechanisms for the characteristic mineralogic assemblages observed are, for (1) and (2), low-grade metamorphism or hydrothermal (<400°C) circulation of fluids in basalt; for (3), transformation of trioctahedral smectites to chlorite and dioctahedral smectites to illite during diagenesis; and for (4), low-grade metamorphism or hydrothermal (<400°C) circulation of fluids in ultramafic rocks. Evidence for high-grade metamorphism at elevated pressures or temperatures >400°C has not been found.
Can Landsat imagery detect tree line dynamics?

Prior research on tree line dynamics has primarily been based on field inventory data, and little is known about the potential for using remotely sensed imagery to detect change. The present study developed a new methodology by combining remote sensing and field survey data to examine dynamics of the pristine forest in the tree line area on Changbai Mountain in Northeast China over the past two decades. The new method normalized remote sensing data by using the adjacent old‐growth coniferous forest (close to climax) below the tree line as the reference (assuming steady state) to eliminate various potential errors associated with different satellite sensors, atmospheric conditions and seasonal vegetation changes. Specifically, we used a ratio of normalised difference vegetation index (NDVI) between the tree line forest (birch) and the referenced old‐growth coniferous forest, as well as a ratio between the interface forest against the referenced coniferous forest, to investigate growth dynamics of the tree line forest from 1977 to 1999. The interface forest is distributed between the tree line forest and non‐forest zone. Compared with traditional methods using remote sensing data, the new method has higher sensitivity to tree line dynamics. We found that the tree line delineated from satellite imagery had shown no shift in the past decades. However, the NDVI ratio of tree line forest against the reference forest increased from 0.9 to 1.2 from 1977 to 1999, and the ratio of interface forest against the reference forest increased from 0.83 to 0.98, indicating that growth of the tree line forest apparently exceeded that of the reference coniferous forest and had grown denser. Field surveys also supported the conclusion from remote sensing results that the tree line forest on Changbai Mountain has grown denser in the past decades. From 1980 to 2002, basal area of the tree line forest increased 35% (from 18.8 to 25.3 m2 ha−1); at the same time the NDVI ratio increased about 33%. This study suggests that it is possible to monitor growth of the tree line forest based on multi‐temporal remote sensing images. We speculate that global warming may have contributed to the observed rapid growth of the tree line forest because temperature is a major limiting factor among climatic variables in the tree line forest and effect from other factors, such as fire, harvesting and snow and wind damage, were not evident in this protected area in the past decades.
Identification of tropospheric ions

Mass spectrometric measurements of naturally occurring atmospheric ions were performed near ground level at Sapelo Island, Georgia. The sampled ions were then passed through a chamber in which they could be dissociated by multiple collisions with a buffer gas. At low-collision energies, H2O clusters were removed, allowing positive core ions to be identified at masses 18, 60, 80, 94, and 108. At high-collision energies, positive core ions were dissociated, and the mass of their fragments was used to help determine their identity. Mass 18 is believed to be NH4+. Methylpyridine and dimethylpyridine were tentatively identified as the parent neutral species responsible for the core ions observed at mass 94 and 108.
Double dayside detached auroras: TIMED/GUVI observations

On August 19, 2003, TIMED/GUVI detected, for the first time, two separated (double) dayside detached auroras (D‐DDA) simultaneously in all the GUVI channels, 121.6 nm, 135.6 nm, LBHS, and LBHL. The D‐DDA was located at magnetic latitudes around −57° and −63° (L shell 3.4 and 4.9) in the 0900–1030 MLT region. The high‐latitude part of the D‐DDA is much brighter than the low‐latitude part. DMSP particle observation indicates that the source of the D‐DDA is energetic (∼10 keV) precipitating protons/electrons from the ring current due to the solar wind dynamic pressure enhancements [ Zhang et al., 2002 ] and/or northward turning of the IMF Bz. Observations of the D‐DDA provide the first single‐event evidence of multiple peaks in the statistical distribution of proton fluxes at energetic around and below 10 keV at low L‐shells [ Milillo et al., 2001 ].
Using remote sensing data to monitor land cover changes near Afghan refugee camps in northern Pakistan

Abstract By the early 1990s, the civil war in Afghanistan had forced more than three million Afghan refugees to resettle in neighboring Pakistan. Although previous studies have noted that refugees have had a negative impact on natural resources in the vicinity of resettlement camps, there has been little work done to quantify these impacts. The research presented here examines the clearing of forests in the Siran Valley, Pakistan, where 111,000 refugees were settled in ten camps between 1978 and 1993. Multi‐temporal satellite images were georeferenced using 1:50,000 scale topographic maps of the study area. A digital elevation model (DEM) was created to stratify by altitude the unsupervised classification of the two images used in the change detection analysis. The elevation data were included in the classification process to reduce the spectral confusion between agricultural and forest land cover classes. The comparison of the satellite images for the two dates show a dramatic decline of forested land. P.
Quantitative analysis of population-scale family trees using millions of relatives

Family trees have vast applications in multiple fields from genetics to anthropology and economics. However, the collection of extended family trees is tedious and usually relies on resources with limited geographical scope and complex data usage restrictions. Here, we collected 86 million profiles from publicly-available online data from genealogy enthusiasts. After extensive cleaning and validation, we obtained population-scale family trees, including a single pedigree of 13 million individuals. We leveraged the data to partition the genetic architecture of longevity by inspecting millions of relative pairs and to provide insights to population genetics theories on the dispersion of families. We also report a simple digital procedure to overlay other datasets with our resource in order to empower studies with population-scale genealogical data. One Sentence Summary Using massive crowd-sourced genealogy data, we created a population-scale family tree resource for scientific studies.
Progress and Challenges of Polymorphic Smart Networks

The current Internet infrastructure and technology system faces major challenges in intelligent, diversified, personalized, highly robust, efficient and other aspects, and it is urgent to reform the network infrastructure. Polymorphic smart network (PINet), as an open network architecture based on full-dimensional definable technology, has been studied by more and more scholars. This paper first introduces the architecture of polymorphic smart network, then introduces the key technologies and related research of polymorphic smart network, then describes its simulation environment, and finally expounds the existing problems and possible breakthrough technologies and key points of PInet.
Recovery from mild head injury.

The subjective and objective sequelae accompanying mild head injury (MHI) are discussed in an attempt to clarify MHI's immediate and long-term consequences. Areas covered included epidemiology, classification, the post-concussive syndrome (PCS), malingering, extent of recovery, rehabilitation and guidelines for clinical practice. Special emphasis is placed on the poor relationship between subjective complaint and objective measures of impairment. Also discussed are some of the methodological problems in the MHI literature, including attempts to match MHI subjects and controls with respect to cognitive and emotional complaint and the possible confounding effects of practice. The evidence for long-lasting (i.e. more than 1 year), subtle neurobehavioral impairment after MHI indicates that additional research is required on MHI 1 year or more after injury.
Frequency-Dependent Electrical Characteristics of Submarine Cables in Low Frequency High Voltage ac (LF-HVac) Transmission for Offshore Wind

Low frequency high voltage ac (LF-HVac) transmission has been proposed as a bulk power transfer alternative to either the conventional 50/60 Hz HVac or the high voltage dc (HVdc) schemes. In LF-HVac transmission, the suggestion is to use fractional values of the conventional 50/60 Hz as the ac operating frequency. Doing so would considerably increase the power transfer capacity of a given transmission cable, extend the range, reduce losses, and improve voltage and dynamic stability of the system. Grid integration of remote offshore wind farms has been identified as the most promising potential application of LF-HVac. Thus, this paper presents a study on the electrical characteristics and performance of submarine cables with respect to the operating frequency. The findings indicate that LF-HVac operation of a cable system would achieve superior power handling capacity and efficiency when compared to HVac operation of the same cable system.
Wind‐driven internal waves and Langmuir circulations in a numerical ocean model of the southern Baltic Sea

[1] A one-dimensional numerical ocean model of the southern Baltic Sea is used to investigate suitable parameterizations of unresolved turbulence and compare with available observations. The turbulence model is a k-e model that includes extra source terms PIW and PLC of turbulent kinetic energy (TKE) due to unresolved, breaking internal waves and Langmuir circulations, respectively. As tides are negligible in the Baltic Sea, topographic generation of internal wave energy (IWE) is neglected. Instead, the energy for deepwater mixing in the Baltic Sea is provided by the wind. At each level the source term PIW is assumed to be related to a vertically integrated pool of IWE, E0, and the buoyancy frequency N at the same level, according to PIW(z) ∝ E0Nδ(z). This results in vertical profiles of e (the dissipation rate of TKE) and Kh (the eddy diffusivity) according to e ∝ Nδ and Kh ∝ Nδ−2 below the main pycnocline. Earlier observations are inconclusive as to the proper value of δ, and here a range of values of δ is tested in hundreds of 10-year simulations of the southern Baltic Sea. It is concluded that δ = 1.0 ± 0.3 and that a mean energy flux density to the internal wave field of about (0.9 ± 0.3) × 10−3 W m−2 is needed to explain the observed salinity field. In addition, a simple wind-dependent formulation of the energy flux to the internal wave field is tested, which has some success in describing the short- and long-term variability of the deepwater turbulence. The model suggests that ∼16% of the energy supplied to the surface layer by the wind is used for deepwater mixing. Finally, it is also shown that Langmuir circulations are important to include when modeling the oceanic boundary layer. A simple parameterization of Langmuir circulations is tuned against large-eddy simulation data and verified for the Baltic Sea.
Formaldehyde over the central Pacific during PEM‐Tropics B

Author(s): Heikes, B; Snow, J; Egli, P; O'Sullivan, D; Crawford, J; Olson, J; Chen, G; Davis, D; Blake, N; Blake, D | Abstract: Formaldehyde, CH2O, mixing ratios are reported for the central Pacific troposphere from a series of 41 flights, which took place in March-April 1999 as part of the NASA Pacific Exploratory Mission (PEM) -Tropics B mission. Ambient CH2O was collected in aqueous media and quantified using an enzyme-derivatization fluorescence technique. Primary calibration was performed using aqueous standards and known flow rates. Occasionally, CH2O gas standard additions to ambient air were performed as a secondary calibration. Analytical blanks were determined by replacing ambient air with pure air. The estimated precision was ±30 pptv and the estimated accuracy was the sum of ±30 parts per trillion by volume (pptv) ±15% of the measured value. Approximately 25% of the observations were less than the instrumental detection limit of 50 pptv, and 85% of these occurred above 6 km. CH2O mixing ratios decreased with altitude; for example, near the equator the median value in the lowest 2 km was 275 pptv, decreased to 150 pptv by 6 km and was below 100 pptv above 8 km. Between 130 and 170 W and below 1km, a small variation of CH2O mixing ratio with latitude was noted as near-surface median mixing ratios decreased near the equator (275 pptv) and were greater on either side (375 pptv). A marked decrease in near-surface CH2O (200 pptv) was noted south of 23° S on two flights. Between 3° and 23° S, median CH2O mixing ratios were lower in the eastern tropical Pacific than in the western or central Pacific; nominal differences were g100 pptv near the surface to ∼100 pptv at midaltitude to ∼50 pptv at high altitude. Off the coast of Central America and Mexico, mixing ratios as high as 1200 pptv were observed in plumes that originated to the east over land. CH2O observations were consistently higher than the results from a point model constrained by other photochemical species and meteorological parameters. Regardless of latitude or longitude, agreement was best at altitudes above 4 km where the difference between measured and modeled CH2O medians was less than 50 pptv. Below 2 km the model median was approximately 150 pptv less than the measured median. Copyright 2001 by the American Geophysical Union.
Historical Change of Large Alluvial Rivers: Western Europe

Recent decades have witnessed a rapid growth in man's understanding of environmental changes over the 10,000-15,000 year timescale and in the 10-50 year timescale. Substantial efforts have been made to link space and time but greater effort is needed to consider changes over the historical timescale of 100-500 years - the period of intensifying human impact culminating in the creation of truly manmade rivers. The synthesis of information from a wide range of sources has enabled general statements on the history of the large alluvial rivers of western Europe to be made. Some of these statements have been compiled into a book which examines the sequence of early river engineering works; cartographic data analyses and applications to channel change; a French case study; the use of geochemical analyses and flood plain stratigraphy in deriving pollution histories; paleoecological methods using fossil invertebrates from alluvial sediments; a case study of the Lower Rhine; reconstruction of fish faunas; historical development of fisheries of the Elbe; Douro, and Ebro; and the variability of historical models of river development as applied to the Garonne, Meuse, Weser, and Rhone rivers. This book marks the first step in the development of a European Network of Scientific Cooperationmore » for the improved management of large rivers, ideally encouraging and advancing the historical analysis of rivers not only in western Europe but worldwide. Such studies will contribute to more rational approaches to river management, to further resource development and to better conservation practice. Separate abstracts have been processed for two papers for inclusion in the appropriate data bases. « less
Climate-Relevant Particulate Emission Characteristics of a Coal Fired Heating Plant

Studies of climate forcing by anthropogenic aerosols require knowledge of the number and properties of the emitted primary aerosol particles. Previous measurements, often limited by instrumental techniques, did not extend far into the nanometer range and considered modern sources with air pollution controls. In the summer of 1996, aerosol size distributions were measured between 3 and 700 nm particle diameter in the exhaust of a low-technology coal-fired heating plant in Leipzig (Germany) using a twin differential mobility particle sizer (TDMPS) system. The total number concentration of particles in the exhaust was approximately 107 particles/cm3, which is an order of magnitude lower than a previously published calculation based on a nucleation/condensation model. An estimate for the number concentration of primary combustion aerosol particles demonstrates the potential importance of such anthropogenic sources.
Properties of biologically formed manganese oxide in relation to soil manganese

Manganese oxide, produced from the oxidation of manganous ions by bacteria at pH 6.5, was extracted with solutions commonly used to estimate the availability of soil manganese to plants. Reducing agents at pH 7.0 completely dissolved the manganese oxide as did sodium ethylene diaminetetra-acetate (EDTA) solutions more acid than pH 6.0. Other acidic solutions extracted part of the manganese in amounts in proportion to the amount of oxide present. Neutral salts extracted only traces of manganese; however, the addition of copper or zinc salts to neutral M ammonium acetate resulted in the release of appreciable amounts of manganese from the oxide. The fact that sodium EDTA solutions and solutions containing copper and zinc released manganese from the bacterial manganese oxide indicates that the practice of extracting soils with these solutions to estimate of organically bound manganese is unsound. The oxide, when pre-heated from 50 to 108°C, became progressively more soluble in neutral M ammonium acetate. Manganese was also rapidly released when the pH of the oxide in suspension was lowered from pH 7 to pH 4. Conversely the oxide rapidly adsorbed manganous ions as the pH was raised from pH 4 to 7. These changes in manganese solubility parallel those reported for soils receiving similar treatments, and it is postulated that the active manganese oxides in soil are similar to bacterial manganese oxide. It is also suggested that the acid-replaceable manganese associated with the oxide plays an important part in the availability of manganese in soils.
On modeling the paleohydrologic response of closed‐basin lakes to fluctuations in climate: Methods, applications, and implications

Climate reconstructions using tree rings and lake sediments have contributed significantly to the understanding of Holocene climates. Approaches focused specifically on reconstructing the temporal water‐level response of lakes, however, are much less developed. This paper describes a statistical correlation approach based on time series with Palmer Drought Severity Index (PDSI) values derived from instrumental records or tree rings as a basis for reconstructing stage hydrographs for closed‐basin lakes. We use a distributed lag correlation model to calculate a variable, ωt that represents the water level of a lake at any time t as a result of integrated climatic forcing from preceding years. The method was validated using both synthetic and measured lake‐stage data and the study found that a lake's “memory” of climate fades as time passes, following an exponential‐decay function at rates determined by the correlation time lag. Calculated trends in ωt for Moon Lake, Rice Lake, and Lake Mina from A.D. 1401 to 1860 compared well with the established chronologies (salinity, moisture, and Mg/Ca ratios) reconstructed from sediments. This method provides an independent approach for developing high‐resolution information on lake behaviors in preinstrumental times and has been able to identify problems of climate signal deterioration in sediment‐based climate reconstructions in lakes with a long time lag.