Miracle-dz/UniFAR-FTUs huggingface dataset:
Examination of the Cooray‐Rubinstein (C‐R) formula for a mixed propagation path by using FDTD

[1] In this paper we extend the Cooray-Rubinstein (C-R) formula into a mixed propagation path (vertically stratified conductivity) and estimate the lightning horizontal electric fields over the mixed path, and we have examined its accuracy at distances of 100 m to 1000 m from the lightning channel by using finite difference time domain (FDTD). When the ground conductivity near the observation point is less than that near the strike point, it is noted that the C-R formula predicts a satisfactory accuracy in the initial several microseconds after the beginning of the return stroke. However, when the ground conductivity near the observation point is larger than that near the strike point, the initial negative excursion predicted by the C-R formula is underestimated, and the error increases with the increase of the difference between the two sections conductivity.
Winter and Summer Structure of the Caribbean Low-Level Jet

Abstract The Caribbean region shows maxima in easterly winds greater than 12 m s−1 at 925 hPa in July and February, herein referred to as the summer and winter Caribbean low-level jet (LLJ), respectively. It is important to understand the controls and influences of the Caribbean LLJ because other LLJs have been observed to be related to precipitation variability. The purpose of this study is to identify the mechanisms of the Caribbean LLJ formation and variability and their association to the regional hydroclimate. Climatological fields are calculated from the North American Regional Reanalysis and the 40-yr ECMWF Re-Analysis from 1979 to 2001. It is observed that the low-level (925 hPa) zonal wind over the Caribbean basin has a semiannual cycle and an interannual variability, with greater standard deviation during boreal summer. The semiannual cycle has peaks in February and July, which are regional amplifications of the large-scale circulation. High mountains to the south of the Caribbean Sea influence .
Integrated Analysis of Ecosystem Interactions with Land Use Change: The Chesapeake Bay Watershed

The Chesapeake Bay is the largest estuary in the United States, encompassed by a watershed extending 168,000 km 2 over portions of six states and Washington, D.C. Restoration of the Bay has been the focus of a two-decade regional partnership of local, state and federal agencies, including a network of scientists, politicians and activists interacting through various committees, working groups, and advisory panels. The effectiveness of the restoration effort has been mixed, with both notable successes and failures. The overall health of the Bay has not declined since the restoration was initiated in 1983, but many of the advances have been offset by the pressure of increasing population and exurban sprawl across the watershed. The needs of the Chesapeake Bay Program are many, but the greatest is accurate information on land cover and land use change, primarily to assess the implications for water quality, examine various restoration scenarios, and calibrate spatial models of the urbanization process. We report here on a number of new land cover and land use data products, and associated applications to assist vulnerability assessment, integrated ecosystem analysis, and ultimately Bay restoration. We provide brief overviews of applications to model new residential development, assess losses and vulnerability of resource lands, and identify the factors that disrupt the health of streams in small watersheds. These data products and approaches are being applied by a number of agencies involved with the restoration effort, including the Chesapeake Bay Program's activities focused on living resources, water quality, and sound land use.
Comparative growth performance of male and female freshwater prawn Macrobrachium tenellum (Decapoda: Palaemonidae) cultured in tropical earthen ponds

The purpose of the present study was to determine the performance growth and yield of male and female Macrobrachium tenellum, cultured in earthen ponds. A total of 6 earthen ponds containing 1,400 ± 50.0 m2 of water and a depth of 0.85 m were used. A total of 19,600 juvenileM. tenellum were introduced into each pond to a stocking density of 14 org m-2. The final length, final weight, specific growth rate, weekly growth rate and yield presented significant differences (P < 0.05) between sexes, with the males exhibiting higher values of these indicators. The survival rate was higher in females (65.0%). The total yield obtained in this culture reached 1,603 kg ha-1. Key words: Macrobrachium tenellum, specific growth rate, weekly growth rate, survival rate, feed conversion. rate.
A limited area model (LAM) intercomparison study of a TWP‐ICE active monsoon mesoscale convective event

[1] A limited area model (LAM) intercomparison study is conducted based on a tropical monsoonal deep convection case observed during the Tropical Warm Pool - International Cloud Experiment (TWP-ICE). The LAM simulations are compared with the variational analyses (VA) based on the Atmospheric Radiation Measurement (ARM) observations and the cloud resolving model (CRM) simulations forced by the VA. Driven by the ECMWF analyses or global model forecasts, LAMs are able to produce the large-scale thermodynamic field reasonably well compared with the VA. However, the LAM simulated dynamic fields, such as the large-scale horizontal divergence, vertical velocity, and cyclogenesis in the monsoonal trough, have a large inter-model spread and deviate substantially from observations. Despite the differences in large-scale forcing, there is certain consistency between the CRM and LAM simulations: stratiform (w ≤ 1 m s−1) ice clouds dominate the cloud fraction and convective (w > 3 m s−1) clouds occupy less than 3 percent of the total cloudy area. But the hydrometeor content of stratiform ice clouds is only one tenth of that of convective and transitional (1 m s−1 < w ≤ 3 m s−1) ice clouds. However, there is a large inter-LAM spread in the simulated cloud fraction and hydrometeor mixing ratios. The inter-LAM difference in solid phase hydrometeors (cloud ice, snow, and graupel) can be up to nearly a factor of 10. Among all the hydrometeor types, the stratiform ice clouds are simulated least consistently by the LAMs. The large inter-LAM spread suggests that obtaining consistent and reliable dynamic and cloud fields remains a challenge for the LAM approach.
Acoustic velocities and electrical properties of frozen sandstones and shales

Ultrasonic velocities and electrical properties have been measured in the laboratory at permafrost temperatures on a number of samples of sandstones and a shale which had been recovered from boreholes in the arctic and stored in their natural frozen state. Compressional and shear-wave velocities, electrical resistivity, and phase-angle relationships in the frequency range 0.005–100 kHz have been measured on the permafrost samples, at temperatures in the range −18 °C–+4 °C.Results of the tests show that, at a particular temperature, there is a small decrease in the electrical resistivity measured on all samples tested as the frequency is increased. The phase-angle differences measured show no consistent relationship with either frequency or temperature, but they are all less than 12° in magnitude. The electrical resistivity at a particular frequency and the ultrasonic velocities are affected in a similar manner by changes in temperature. Whereas the sandstones show a sharp reduction in velocities and resistivity as the temperature is raised to 0 °C or above, the shale shows little dependence of these parameters on changes in temperature in the range tested. An increase in shale content of the sandstone results in behavior intermediate between that of a clean sandstone and that of a shale.
Beyond the suburban high street cliché - A study of adaptation to change in London’s street network: 1880-2013

This article addresses the question of how the fringes of cities develop spatially at both the local scale of the individual town centre and in relation to the wider urban network. The changing network structure of the street systems of two outer suburban areas of Greater London, Surbiton and South Norwood, are analysed from the 1880s onwards. A temporal reading of the process of urban growth in relation to the historic street network of local centres allows for a nuanced understanding of the way in which cities grow over time. Rather than conceptualising suburban growth as either a seeding of new territories in tabula rasa or a ‘swallowing-up’ of older settlements, this article argues for a measured description of the spatial, social and economic properties of urban grid intensification. This research uses digitised historical maps, historical and contemporary land-use data together with space syntax analysis in order to identify historical-morphological parameters of change and continuity in London’s suburban street network from the 1880s. The analysis demonstrates that over the period of time considered there have been distinct stages in the spatial development of the city’s urban fringe. The results show that as London expanded to encircle new territories, the spatial relationships of fringe areas of the city changed markedly as larger scale infrastructure was built and local development intensified, with the effect of reconfiguring the local network of the case study suburbs. However, detailed analysis of the formation of suburban town centres using space syntax also uncovers distinctive and resilient spatial morphologies which have sustained varied modes of land use over time. Drawing on the theory of the urban ‘movement economy’ and our previous research in this area, the article shows how the complex balance of change and continuity realised in the spatial morphology of the suburban high street can be explained by complex scalar mechanisms of adaptability. We argue that these qualities have helped ensure the resilience of historical suburban centres even in the face of radical social change.
Behaviour of chemical solutes during a storm in a rainforested headwater catchment

The aim of this study is to identify, in a small catchment area located within a tropical forest, the pedological compartments in which the export of nutrients and chemical erosion of solutes occur during a stormflow event. The catchment area displays two types of lateral flow: (i) overland flow at the surface of the soil in the litter and root mat and (ii) groundwater flow in a macroporous subsurface horizon. We interpret the variations of stream‐water chemistry during a storm‐flow event using the separation of storm‐flow hydrograph data between overland and groundwater flow, and (Cl−) as a chemical parameter characterizing the residence time of water in the soil. It appears that K+ especially was released into the throughfall, whereas Ca++, Mg++ and Na+ were clearly released from the litter. K+ disappeared rapidly from soil solution, whereas Ca++ and Mg++ were more progressively absorbed by the vegetation. The Ca++ and Mg++ contents in groundwater increased with increasing residence time owing to the transpiration of trees. The export of H4SiO4 in the overland flow was moderate, i.e. 24% of total H4SiO4 export in the stream flow, as overland flow represented 39% of total runoff. The subsurface horizon—where active groundwater flow occurs—was successively affected by chemical erosion during the storm‐flow peak, and then by neoformation of kaolinite favoured by increasing water residence time. Copyright © 2003 John Wiley & Sons, Ltd.
Grip Strength across the Life Course: Normative Data from Twelve British Studies

Introduction Epidemiological studies have shown that weaker grip strength in later life is associated with disability, morbidity, and mortality. Grip strength is a key component of the sarcopenia and frailty phenotypes and yet it is unclear how individual measurements should be interpreted. Our objective was to produce cross-sectional centile values for grip strength across the life course. A secondary objective was to examine the impact of different aspects of measurement protocol. Methods We combined 60,803 observations from 49,964 participants (26,687 female) of 12 general population studies in Great Britain. We produced centile curves for ages 4 to 90 and investigated the prevalence of weak grip, defined as strength at least 2.5 SDs below the gender-specific peak mean. We carried out a series of sensitivity analyses to assess the impact of dynamometer type and measurement position (seated or standing). Results Our results suggested three overall periods: an increase to peak in early adult life, maintenance through to midlife, and decline from midlife onwards. Males were on average stronger than females from adolescence onwards: males’ peak median grip was 51 kg between ages 29 and 39, compared to 31 kg in females between ages 26 and 42. Weak grip strength, defined as strength at least 2.5 SDs below the gender-specific peak mean, increased sharply with age, reaching a prevalence of 23% in males and 27% in females by age 80. Sensitivity analyses suggested our findings were robust to differences in dynamometer type and measurement position. Conclusion This is the first study to provide normative data for grip strength across the life course. These centile values have the potential to inform the clinical assessment of grip strength which is recognised as an important part of the identification of people with sarcopenia and frailty.
Shallow magma accumulation at Kīlauea Volcano, Hawai‘i, revealed by microgravity surveys

for vertical displacement) at the summit of about −1.3 m and −160 µGal, respectively. The volume of magma lost (based on grav- ity data and assuming a reasonable magma density) exceeded the volume of summit col- lapse, suggesting the creation of 40-90 × 10 6 ABSTRACT Using microgravity data collected at Kīlauea Volcano, Hawai'i (United States), between November 1975 and January 2008, we document signifi cant mass increase beneath the east margin of Halema'uma'u Crater, within Kīlauea's summit caldera. Surprisingly, there was no sustained uplift accompanying the mass accumulation. We propose that the positive grav- ity residual in the absence of signifi cant uplift is indicative of magma accumulation in void space (probably a network of interconnected cracks), which may have been created when magma withdrew from the summit in response to the 29 November 1975 M = 7.2 south fl ank earthquake. Subsequent refi lling documented by gravity represents a gradual recovery from that earthquake. A new eruptive vent opened at the summit of Kīlauea in 2008 within a few hundred meters of the positive gravity residual maximum, probably tapping the reservoir that had been accumulating magma since the 1975 earthquake.
Radiative forcing of climate change by CFC‐11 and possible CFC replacements

The infrared absorption cross sections of CFC-11 and 16 other halogenated compounds have been measured. These spectra were used in detailed line-by-line calculations to derive radiative forcing values. The radiative forcing values for 14 of these gases have not, to our knowledge, been previously reported in the literature. The accuracy of a computationally inexpensive narrowband scheme, which included the effect of clouds and stratospheric adjustment, was investigated. Global warming potentials are presented where atmospheric lifetimes are available. In light of the substantial disagreement in values for the forcing due to CFC-11 reported in the literature and its use as a standard to which other halogenated gases are often compared, we examined the sensitivity of CFC-11 forcing to a number of assumptions. We find that the uncertainties in the calculated value of the radiative forcing caused by neglect of the temperature and pressure dependence of the IR absorption spectrum are much smaller than those resulting from uncertainties in the absolute absorption cross sections or the vertical profile of CFC-11. Our best estimate is 0.285 W m−2 ppbv−1, which is 30% higher than the value adopted by the Intergovernmental Panel on Climate Change and is believed to be accurate to within about 10%. For the other gases represented here the lack of detailed knowledge of the likely vertical and horizontal distribution probably represents the most significant uncertainty in evaluating their radiative forcing.
Carbon 13/Carbon 12 ratios of sedimentary organic matter from the Ross Sea, Antarctica: A record of phytoplankton bloom dynamics

Suspended and sea ice particulate organic carbon (POC) collected from the Ross s 13 In r Sea, Antarctica, shows seasonal enrichments in C unrelated to at osphe ic pCO2 varia- tions. The carbon isotopic composition of phytoplankton bloom-related POC (53Cpoc) col- lected from the southwestern Ross Sea during a 1992 bloom event is strongly correlated with POC concentration. This correlation may be attributed to high growth rates, species-specific fractionation, input from sea ice communities enriched in 3C, increased heterotrophic recy- cling, or high rates of bloom-related CO2(aq) drawdown in the upper water column. While all these factors likely contribute to POC 3C enrichment, we favor the latter hypothesis because of the link betweenC enrichment and partial isolation of the surface water CO2 pool in ar- eas of sea ice melt-induced stratification of the upper water column. The CO2 drawdown hy- pothesis is further supported by dissolved inorganic carbon 53C enrichments of up to 2-3%0 in the vicinity of phytoplankton blooms. Patterns of isotopic composition and organic carbon concentration in Ross Sea surface sediments resemble that of the upper water column, par- ticularly in areas of frequent, annually recurrent phytoplankton blooms. Overall, surface sediment 5C values are 1-3%o enriched relative to surface water POC, with the highest 53C values found in areas that receive large amounts of phytoplankton bloom detritus. Future downcore carbon isotopic analyses may prove useful as tracers of bloom dynamics in melt- water-influenced areas, where large enrichments in 3C coincide with high productivity.
Model for the prediction of shear strength with respect to soil suction

Experimental studies on unsaturated soils are generally costly, time-consuming, and difficult to conduct. Shear strength data from the research literature suggests that there is a nonlinear increase in strength as the soil desaturates as a result of an increase in matric suction. Since the shear strength of an unsaturated soil is strongly related to the amount of water in the voids of the soil, and therefore to matric suction, it is postulated that the shear strength of an unsaturated soil should also bear a relationship to the soil-water characteristic curve. This paper describes the relationship between the soil-water characteristic curve and the shear strength of an unsaturated soil with respect to matric suction. Am empirical, analytical model is developed to predict the shear strength in terms of soil suction. The formulation makes use of the soil-water characteristic curve and the saturated shear strength parameters. The results of the model developed for predicting the shear strength are compared w.
Estrategia para identificar jales con potencial de riesgo ambiental en un distrito minero: estudio de caso en el Distrito de Guanajuato, México

Se desarrollo una estrategia para identifi car jales con potencial de riesgo ambiental en el Distrito Minero de Guanajuato. Se ubicaron los depositos de jales de cianuracion y fl otacion que existen en la zona y para cada deposito se compilo informacion respecto a los yacimientos de origen, el metodo de benefi cio y construccion del cual resultaron, y el tiempo que llevan expuestos a la atmosfera. Tambien se describio su situacion actual respecto a la erosion. Se escogieron cinco depositos de jales representativos del origen geologico, para los cuales se describieron y colectaron muestras compuestas superfi ciales y de perfi les de hasta maximo 1 metro de profundidad. Se determinaron evidencias morfologicas de acidifi cacion en campo (color, textura al tacto, contenido de carbonatos y estructura) y en las muestras se cuantifi co el contenido total de cobre, plomo y zinc. Se encontraron 31 depositos de jales, los cuales ocupan un area de 81.9 hectareas y representan 40.3 millones de toneladas. Hay once depositos de jales de cianuracion construidos entre 1905 y 1946, de los cuales cuatro estan fuertemente erosionados. Hay veinte presas de jales de fl otacion 'bulk', cuyos depositos presentan una clasifi cacion textural: las areas proximales a la cortina de retencion son de textura arenosa, tienen baja capacidad de retencion de humedad y estan bien aireadas, mientras que las zonas distales a la cortina tienen textura arcillosa, baja permeabilidad y baja capacidad de aireacion, lo que permite la acumulacion de agua en tiempo de lluvias y favorece condiciones reductoras. Todos los jales tienen pH alcalino, excepto los horizontes arenosos de un sitio con 75 anos de abandono (Pozuelos) con pH de 5, que indica que en condiciones bien aireadas y drenadas se presenta acidifi cacion local. Las concentraciones de metales en los jales son de medias a altas segun normas de diferentes paises: 37 a 429 mg/kg de Cu, 13 a 178 mg/kg de Pb y 36 a 448 mg/kg de Zn. El origen geologico de los jales determina las concentraciones de metales, ya que residuos provenientes de menas tipo 'stockwork' tienen menores concentraciones de metales que los extraidos de vetas o brechas. Los jales de fl otacion presentan una gran variabilidad espacial en sus contenidos de metales relacionada con la clasifi cacion textural dentro del deposito, de tal manera que las zonas proximales tienen concentraciones de metales mas bajas que las distales. La estrategia propuesta fue util para identifi car los factores que determinan la distribucion de elementos con potencial toxico en los jales de la region asi como para evaluar el potencial de acidifi cacion. En este caso los factores que controlan las concentraciones de metales fueron el origen geologico y la clasifi cacion textural, mientras que la acidifi cacion es controlada tanto por el origen geologico como por la presencia de humedad y es mas favorecida en texturas gruesas.
Exhumation as fast as subduction

We produced a pressure-temperature-time path in order to determine the exhumation rate of the deepest subducted Alpine rocks. In situ dating of peak-metamorphic titanite in an eclogite facies calc-silicate rock indicates that subduction to pressures of ∼3.5 GPa was reached at 35.1 ± 0.9 Ma. Titanite formed during two decompression stages, at 1 ± 0.15 GPa and ∼0.4–0.5 GPa, and yielded ages of 32.9 ± 0.9 Ma and 31.8 ± 0.5 Ma, respectively. Combining the age data and making assumptions about the conversion of pressure to depth yield mean exhumation rates of 3.4 cm/yr and 1.6 cm/yr. These rates imply that exhumation acted at plate tectonic speeds similar to subduction, and was significantly faster than erosion. We suggest that fast exhumation is driven by a combination of tectonic processes involving buoyancy and normal faulting.