Miracle-dz/UniFAR-FTUs huggingface dataset:
Validation of ICESat-2 ATLAS Bathymetry and Analysis of ATLAS's Bathymetric Mapping Performance

NASA’s Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2) was launched in September, 2018. The satellite carries a single instrument, ATLAS (Advanced Topographic Laser Altimeter System), a green wavelength, photon-counting lidar, enabling global measurement and monitoring of elevation with a primary focus on the cryosphere. Although bathymetric mapping was not one of the design goals for ATLAS, pre-launch work by our research team showed the potential to map bathymetry with ICESat-2, using data from MABEL (Multiple Altimeter Beam Experimental Lidar), NASA’s high-altitude airborne ATLAS emulator, and adapting the laser-radar equation for ATLAS specific parameters. However, many of the sensor variables were only approximations, which limited a full assessment of the bathymetric mapping capabilities of ICESat-2 during pre-launch studies. Following the successful launch, preliminary analyses of the geolocated photon returns have been conducted for a number of coastal sites, revealing several salient examples of seafloor detection in water depths of up to ~40 m. The geolocated seafloor photon returns cannot be taken as bathymetric measurements, however, since the algorithm used to generate them is not designed to account for the refraction that occurs at the air–water interface or the corresponding change in the speed of light in the water column. This paper presents the first early on-orbit validation of ICESat-2 bathymetry and quantification of the bathymetric mapping performance of ATLAS using data acquired over St. Thomas, U.S. Virgin Islands. A refraction correction, developed and tested in this work, is applied, after which the ICESat-2 bathymetry is compared against high-accuracy airborne topo-bathymetric lidar reference data collected by the U.S. Geological Survey (USGS) and the National Oceanic and Atmospheric Administration (NOAA). The results show agreement to within 0.43—0.60 m root mean square error (RMSE) over 1 m grid resolution for these early on-orbit data. Refraction-corrected bottom return photons are then inspected for four coastal locations around the globe in relation to Visible Infrared Imaging Radiometer Suite (VIIRS) Kd(490) data to empirically determine the maximum depth mapping capability of ATLAS as a function of water clarity. It is demonstrated that ATLAS has a maximum depth mapping capability of nearly 1 Secchi in depth for water depths up to 38 m and Kd(490) in the range of 0.05–0.12 m−1. Collectively, these results indicate the great potential for bathymetric mapping with ICESat-2, offering a promising new tool to assist in filling the global void in nearshore bathymetry.
Ionospheric Peaked Structures and Their Local Time, Seasonal, and Solar Activity Dependence Based on Global Ionosphere Maps

The total electron content (TEC) data from Global Ionosphere Maps are used to obtain the tidal modes through two‐dimensional Fourier transform in both universal time and LT (local time) frames. In the LT frame, a north‐south TEC asymmetry is observed along the longitude, where there is a large displacement of the geomagnetic equator from the geographic equator. The phases of tidal modes lead to a constructive or destructive interference of contributing tidal modes, producing different zonal waves and longitudinal peaked structures at different local time (tLT). The summation of all nonmigrating zonal waves in the low‐latitude region (geomagnetic latitude < 30°) produces a peaked structure with two to four major peaks at most local hours. The amplitude of this peaked structure in June solstice is smaller than those in other seasons. During solar maximum (minimum), the amplitude of peaked structure has a value ~20 (~12) TECu with two to four (one to three) peaks. The locations of peaked structures formed by the nonmigrating tides in 2006 (solar minimum) and in 2014 (solar maximum) are similar. The Weddell Sea Anomaly is found to have a density enhancement in the region from 135°E to 90°W and from 40°S to 80°S with an amplitude ~19.85 (~5.07) TECu during March equinox (December solstice) of solar maximum (minimum).
Spatial segregation and urban form in Mexican cities

With a population of more than 120 million people, most Mexican cities suffer from socioeconomic inequalities and these are worsened by spatial inequalities resulting from their urban form and structure. A number of studies have been published looking at limited public services and how this may affect those on lower incomes in Mexico. However, very few studies have used spatial accessibility as a means of explaining urban inequalities and informing city planning. Spatial accessibility is defined as the measurable geographical access from residential locations to destinations for services and public goods. This paper investigates the potential of a spatial accessibility index to provide evidence for making location/planning decisions that benefit the largest number of residents. To achieve this aim, we combine three geographical secondary data sets with geospatial analysis. First, two important urban public services, i.e. health and education, are located, and catchment areas are then generated according to their respective sizes. For the second set, the integration values of each city at metropolitan and district scales are calculated using Space Syntax to observe how its configuration may influence the distribution of activities and the way the inhabitants live and move. The third set is demographic data from the 2010 national census of Population and Housing, analysed at the residential block level. This paper focuses on the results of combining two accessibility indices (cumulative opportunities and Space Syntax’s integration value) that examine the degree to which the lack of a basic public service could be associated with the spatial segregation of an area to provide evidence (comprehensible by decision-makers) for making location and planning decisions that benefit the largest number of residents.
Geochemical characteristics of fluorine in coal within Xiangning mining area, China, and associated mitigation countermeasures

The geochemical characteristics of fluorine in coal obtained from 534 borehole exploration data and mining test data from the Xiangning mining area were studied, and fluorine emissions were calculated. Results reveal that the fluorine content in Carboniferous-Permian coal in the mining area ranges from 2.00 to 911.00 mg/kg, and the Carboniferous coal seam contents are generally higher than those of the Permian system. The calculated average fluorine contents in Nos. 5 and 12 coal seams of the Carboniferous system are 203.42 and 308.00 mg/kg, respectively, and therefore, both are high-fluorine coal. In addition, the calculated mean fluorine contents of Nos. 2 and 10 coal seams are 168.58 and 187.02 mg/kg, respectively, which are higher than average value of Chinese and global coal values. The highest fluorine content of 896.00 mg/kg is found in medium- to high-fluorine coal. Fluorine in coal mainly exists in an inorganic bound state in forms such as fluorapatite and calcium fluoride. The Xiangning Coal Mine predominantly produces coal for coking and power, and the release of fluorine during coal combustion is harmful to the environment. According to the information obtained in relation to coal resource reserves and development planning, the amount of fluorine released from combustion is estimated at 2258.1 t/year and is estimated to reach 4862.9 t/year by 2020. Coal washing is an effective way of reducing fluorine emissions, and flotation experiments have shown that this can reduce the amount of fluorine by up to 30–47%. Different engineering measures, such as denitrification and desulfurization, can also significantly reduce the amount of fluorine released during coal combustion and can thus be employed to reduce the associated environmental impacts.
U.S. Hydrologic Design Standards Insufficient Due to Large Increases in Frequency of Rainfall Extremes

Evidence for intensifying rainfall extremes has not translated into “actionable” information needed by engineers and risk analysts, who are often concerned with very rare events such as “100‐year storms. ” Low signal‐to‐noise associated with such events makes trend detection nearly impossible using conventional methods. We use a regional aggregation approach to boost this signal‐to‐noise, showing that such storms have increased in frequency over much of the conterminous United States since 1950, a period characterized by widespread hydrologic infrastructure development. Most of these increases can be attributed to secular climate change rather than climate variability, and we demonstrate potentially serious implications for the reliability of existing and planned hydrologic infrastructure and analyses. Though trends in rainfall extremes have not yet translated into observable increases in flood risks, these results nonetheless point to the need for prompt updating of hydrologic design standards, taking into consideration recent changes in extreme rainfall properties.
Oxygen Isotopic Exchange Between CO2 and Phosphoric Acid: Implications for the Measurement of Clumped Isotopes in Carbonates

Experiments have been conducted in which CO2 gases with varying C and O isotopic compositions and with stochastic and nonstochastic Δ47 values have been allowed to equilibrate with phosphoric acid of two concentrations in reaction vessels of varying dimensions at temperatures of 25 and 90 °C. Rates of 13C18O and 18O exchange between the CO2 and the phosphoric acid varied as a function of the length of exposure, volume of reaction vessel, acid strength, and difference of the initial Δ47 and δ18O values of the CO2 from theoretical equilibrium values. The Δ47 values were also altered by heated stainless steel surfaces such as those found within the Kiel device and other preparation systems. These results have been used to explain variations in the differences in the fractionation between 25 and 90 °C reported for calcite by different workers as well as differences in the slopes between temperature and Δ47 values produced by reacting samples at different temperatures (25 and 90 °C).
Liming Effects of Sawdust Ash and Lime on Sunflower (Helianthus annuus L.) Yield in Acidic Soil of Southeastern Nigeria

Aim: A pot experiment was carried out to determine the effect of sawdust ash and lime (Ca(OH)2) on soil characteristics and yield of sunflower in acidic soil of southeastern Nigeria. Study Design: The experiment was laid out in split-plot design, using sawdust ash (0, 1, 2, 3, 4 t ha-1) as the sub plot and lime (0, 0.5, 1.0, 1.5 t ha-1) as the main plot. Place and Duration of Study: Study was conducted outdoors at Michael Okpara University of Agriculture Umudike, Nigeria, during the 2010 planting season. Materials and Methods: Treatment combinations were applied to the 60 buckets containing soil, mixed thoroughly and watered adequately. After 1 week of treatment application, two sunflower seeds were planted and later thinned to one seedling per bucket. Plant growth and yield data were collected. Pre planting and post-harvest soil samples were collected and analyzed for soil properties. Results: Results showed that with the exception of organic carbon there was significant effect of treatments on all soil chemical properties. Lime and sawdust ash (SDA) as single and combined treatments significantly increased total nitrogen (P=0.05), available phosphorus (P<0.010), and base saturation (P<0.012). The interaction between SDA and lime significantly (P=0.05) increased total exchangeable bases and effective cation exchange capacity, while soil pH was significantly increased (P=0.05) by single applications. The increases in soil chemical properties led to significant positive response of the sunflower. With the exception of number of leaves, other plant parameters (Plant height, stem diameter, head weight, 50 seed weight, head diameter) had significant increases for sawdust ash alone at P=0.05. Correlation studies showed positive significant relationship between soil pH and sunflower yield. Conclusion: The study showed that sunflower performed best at the combination of 3 tha-1 SDA and 1.5 t ha-1 lime producing a mean head weight of 45.4 g.
Effects of forest age and topography on boreal forest evapotranspiration and water balance

Barker, Corinne Alison. M.Sc., The University of Manitoba, May, 2008. Effects of Forest Age and Topography on Boreal Forest Evapotranspiration and Water Balance. Major Professor; Brian D. Amiro. The boreal forest forms a band that stretches across the continents of the northern hemisphere. Wildfire disturbances have helped transform this forest into stands of varying ages with varying soil drainage. It is well known that the boreal forest contributes greatly to the global water cycle, but less is known as to how variable these water fluxes are throughout the forest mosaic. Throughout the growing seasons of 2006 and 2007, meteorological measurements were taken during the growing season from three different aged black spruce stands near Thompson, MB. The stands that were burned in 1930 and 1964 each included upland and lowland sites with independent measurements. The stand burned in 1850 had measurements taken only from an upland site. Evapotranspiration (ET) was calculated from the residual energy after net radiation (Rn), sensible heat flux (H) and ground heat flux were measured. We sought to investigate whether ET varied with stand age and topographic location. Results indicate that there is a significant increase in Rn, H, and ET as forests age. ET levels range from being 4% to 19% lower for younger stands. It is assumed that the depth of the organic layer at older sites allows for mosses to more effectively wick up available moisture through capillary rise, and have higher transpiration levels. The larger tree density at the 1964 sites compared to the 1930 sites may account for a portion of the observed increase in ET for these ages. Differences in drainage between the 1930 and 1850 sites may also account for a portion of the increase in ET observed between these two ages.
Fire Preparedness in Secondary Schools in Eldoret West Sub-County, Uasin-Gishu County, Kenya

Background: Fire incidents in schools are worldwide phenomena that primarily range from being highly localized to global in scope. Safety of students and staff members pertaining to hazards, created by unsafe behavior, disasters or emergencies in schools cannot be guaranteed. Objectives: The current study examined the capacity of secondary schools in coordination and communication of fire preparedness well as level of awareness and adaptive capacity. Methodology: The study employed a descriptive survey design. Proportionate sampling technique was adopted to select 16 out of the 80 secondary schools. Participants in the study constituted head teachers and other teaching staff in charge of safety, laboratory assistants and the chef. In addition, 280 students were selected from the 16 schools through random probabilistic sampling well as the DEO, 5 ZQAOs and 2 members of fire brigade team in the municipality within the district. Questionnaires and interview guides were used to collect data. Results: Sixty five per cent of the schools did not have disaster preparedness policies and plans. However, all head teachers acknowledged that it existed. 81% of schools did not have any alternative learning area neither emergency exits in the event of a disaster. Emergency instructions for safety in the event of disaster occurrence were lacking in many schools as acknowledged by 63% of respondents. Slightly more than half of the schools indicated evacuation drills and regular disaster preparedness meetings are never carried out. 63% of the teachers opined that their schools lacked laid-down procedures during emergency periods. Conclusion: Negligible percentage of schools had designated teachers, being in charge of safety. Students had no sufficient knowledge on what to do in case of fire outbreak. There were no adequate training on disaster preparedness and prevention among staff members and students. Findings show a larger percentage of teachers and students do not know how to use fire-fighting equipment. Recommendation: Therefore, the study recommends capacity building programs among academic stakeholders on fire disaster preparedness and provision of fire safety support resources for combating fire disasters in all schools. The MoE should inspect and set ministerial regulations and guidelines on safety issues in all schools to ensure actualization of school safety manuals in blue print and needed commitment.
Community composition and catabolic functional diversity of soil microbes affected by Hedysarum scoparium in arid desert regions of northwest China

Abstract The soil microbial community and edaphic factors in the rhizosphere and bulk soils of Hedysarum scoparium were investigated at seven arid desert locations in northwest China in July 2016. Plant and edaphic factors had significant effects on the community composition and functional diversity of soil microbes. Bacteria (ranging from 2.57 to 4.23 nmol g−1) contributed the most to the microbial community composition, followed by actinomycetes, followed by fungi. Carbohydrates, polymers, and carboxylic acids were the main carbon sources for soil microorganisms. Principal component analysis showed that the carbon source catabolism of soil microorganisms was higher in the rhizosphere than in bulk soils. Spearman correlation analyses revealed that the content of Gram-negative bacteria was significantly negatively correlated with the amino acids and that the content of AM fungi was significantly positively correlated with the carbohydrates and amines. Soil organic carbon, pH, and ammoniacal-N were significant predictors of microbial community composition, whereas soil organic carbon, phosphatase activity, and soil moisture were closely correlated with microbial carbon catabolism. This study indicated that soil microbial community composition and functional diversity are influenced by plants, nutrient availability, and enzymatic activity in the arid desert and serve as useful indicators for evaluating the soil quality and function of the desert ecosystem based on their relationships with the microbial community and soil nutrient distribution.
How to predict preferences for new items

Huge amounts of data and lots of competing methods for estimating the usefulness of a certain known item to a specific user exist. However, most of these procedures only work well if the items are already well-known. Nevertheless, the users of a recommender-system might be more interested in receiving recommendations for items, which they have never heard of before than to keep getting items recommended that they have already been told or read about numerous times before. Also, from a marketer's point of view the preferences for new or even hypothetical items are more important. E.g., such information might be useful in deciding, whether a particular new item should be added to the product portfolio of an online store. A number of different techniques for estimating the preferences for new items are introduced and their performance is evaluated and compared with respect to the different purposes of preference estimation. A combination of two-mode clustering and Hierarchical Bayes regression is shown to be a good and highly interpretable estimation method. A quick heuristic procedure is developed, by which more useful recommendations with respect to new items can be generated.
Extension at the coast of the Makran subduction zone (Iran)

In the Makran subduction zone, earthquake focal mechanisms and geodetic data indicate that the deforming prism currently experiences N–S compression. However, palaeostress inversions performed on normal faults observed along the coast reveal local stress components consistent with N‐S extension. Previously proposed mechanisms such as gravitational collapse are not favoured by N–S compression and surface uplift. We propose that the observed kinematics result from transient stress reversals following large earthquakes. During the interseismic period (now), the region experiences N–S compression. However, following a large reverse rupture on the subduction interface, stresses in the inner wedge relax, enabling a brief period of extensional faulting before a compressive stress state is re‐established. This mechanism, also observed in other subduction zones, requires low overall stresses in the upper plate and that the margin ruptures in large megathrust earthquakes that result in nearly complete stress drops.
Investigation of Focused Wave Impact on Floating Platform for Offshore Floating Wind Turbine: A CFD Study

Most existing research related to a semi-submersible offshore floating platform focuses on the wave-structure interaction under either a regular or irregular wave condition. In order to numerically model the irregular wave impact on a semi-submersible platform hydrodynamic response with a low computational cost, in this study, a focused wave is utilized. The platform under this consideration is the DeepCwind semi-submersible platform. A high fidelity CFD numerical solver based on solving Navier-Stokes equations is adopted to estimate the dynamic response and the hydrodynamic loading of the platform. The focused wave is firstly generated based on a first order irregular wave theory in a numerical wave tank and validated against the linear wave theory results. Next, for CFD coding validation, the surface elevation of a fixed FPSO model associated with a focused wave is calculated and compared with the benchmark results. At last, the dynamic responses of the platform are numerically simulated under various focused wave parameters, and the results are compared with those obtained from an in-house potential flow theory tool at Électricité de France (EDF). It is found that the predicted CFD surge motion responses are close to those achieved with the second order potential theory while differ from the results obtained using linear potential theory. As to the pitch motion, differences are observed between two results, due to the different methods used for second order loads and viscous effects calculation. Turning to the results under different wave parameters, the surge and heave motion responses increase as the wave period goes up. However, the pitch motion is not affected significantly by varying wave periods. It may be due to the fact that the low-frequency effects have limited impact on the pitch motion. The strong nonlinearity at extremely large wave amplitude will be the task in our near future study.