Miracle-dz/UniFAR-FTUs huggingface dataset:
Quenching of metastable states of atomic and molecular oxygen and nitrogen

The quenching (or deactivation) of metastable states by atmospheric particles is studied by means of a combination of laboratory and observational data. The observational data come mainly from recent rocket measurements of the dayglow. The laboratory results of Kvifte and Vegard are considered in detail, and it is found that the quenching coefficients of O2 for both metastable states of atomic oxygen are very small. The strong atmospheric quenching of the O red lines ( ¹D state) is found to be produced by N2, with a coefficient approaching the gas-kinetic value. The auroral data that gave a lower quenching rate disagree with the dayglow results and must be rejected; the difficulty is traced to contamination of low-altitude spectra by light from higher altitudes. Only less detailed treatment of other atoms, molecules, and ions can be made; however, some conclusions are possible. Quenching coefficients seem to range from large to very small in a totally unpredictable fashion. Quenching by electrons is important in only a few special cases. The quenching of vibrationally excited O2 and N2 is slow enough so that significant concentrations can be built up, especially for N2 in aurora.
Photoreductive dissolution of ferrihydrite by methanesulfinic acid: Evidence of a direct link between dimethylsulfide and iron‐bioavailability

Within open‐ocean regions where excess macronutrients are present, phytoplankton growth is limited by the bioavailability of iron supplied to these areas primarily within atmospheric aerosols of crustal origin. However, processes that control the abundance of biologically accessible iron in these aerosols are largely unknown. Here we show that dissolution of ferrihydrite, a surrogate iron(oxy)hydroxide phase found in atmospheric waters, is enhanced in the presence of methanesulfinic acid (MSIA, CH3SO2H, a dimethylsulfide (DMS) oxidation intermediate) in laboratory irradiation experiments with aqueous suspensions that simulate marine aerosol particles. The increased release of soluble Fe(II) is attributed to a species specific and direct photochemical reduction rather than a proton‐promoted effect, and suggests an efficient mechanism by which iron‐starved phytoplankton can actively increase aerosol iron‐bioavailability by increasing DMS emissions.
A 20-Yr Average of the Indonesian Throughflow: Regional Currents and the Interbasin Exchange

Twenty years of monthly or more frequent repeat expendable bathythermograph data are used to estimate the mean geostrophic velocity and transport relative to 750 m of the Indonesian Throughflow (ITF) and its partitioning through the major outflow straits into the Indian Ocean. Ekman transports are estimated from satellite and atmospheric reanalysis wind climatologies. A subsurface maximum near 100 m characterizes the geostrophic ITF, but Ekman flows drive a warm near-surface component as well. A subsurface intensified fresh Makassar Jet feeds the Lombok Strait Throughflow (2 Sv; 1Sv 10 6 m 3 s 1 ) and an eastward flow along the Nusa Tenggara island chain [the Nusa Tenggara Current (6 Sv)]. This flow feeds a relatively cold 3.0-Sv flow through the Ombai Strait and Savu Sea. About 4–5 Sv pass through Timor Passage, fed by both the Nusa Tenggara Current and likely warmer and saltier flow from the eastern Banda Sea. The Ombai and Timor Throughflow feature distinctly different shear profiles; Ombai has deepreaching shear with a subsurface velocity maximum near 150 m and so is cold (15.5°–17.1°C), while Timor Passage has a surface intensified flow and is warm (21.6°–23°C). At the western end of Timor Passage the nascent South Equatorial Current is augmented by recirculation from a strong eastward shallow flow south of the passage. South of the western tip of Java are two mean eastward flows—the very shallow, warm, and fresh South Java Current and a cold salty South Java Undercurrent. These, along with the inflow of the Eastern Gyral Current, recirculate to augment the South Equatorial Current, and greatly increase its salinity compared to that at the outflow passages. The best estimate of the 20-yr-average geostrophic plus Ekman transport is 8.9 1.7 Sv with a transport-weighted temperature of 21.2°C and transport-weighted salinity of 34.73 near 110°E. The warm temperatures of the flow can be reconciled with the much cooler estimates based on mooring data in Makassar Strait by accounting for an unmeasured barotropic and deep component, and local surface heat fluxes that warm the ITF by 2°– 4°C during its passage through the region.
Natural mixture of silica and smectite as a new clayey material for industrial applications

Abstract The main physico-chemical properties of a new smectitic clay containing large amounts of amorphous material are reviewed and potential industrial applications of this type of clay are discussed. Due to a 34% amorphous material content (natural silica gel), the investigated clay has very high porosity and can be used as it is or in acid-impregnated form for oil bleaching or phosphate reduction in edible oil. In the field of biodiesel purification, the new clay can be used to remove, in particular, mono-, diglycerides and glycerol. The natural silica-smectite mixture is also suitable as a carrier for liquid ingredients, for example in animal feeds, and might serve as a partial or complete substitute for synthetic precipitated silicas. In the field of bioseparation processes, the clay can be used as an adsorbent for protein separation by means of cation exchange. Due to the suppressed swelling (compared with smectite alone), it can be packed in columns which can be regenerated.
Photogrammetric features for the registration of terrestrial laser scans with minimum overlap

The interest and demand for 3 Dimensional (3D) documentation of man-made structures have increased with the continuous improvement in data acquisition systems and the expanding range of potential applications. Currently, 3D data can be obtained through two technologies: photogrammetry and laser scanning. In spite of the proven quality of static laser scanning, the collection and processing of laser scans is a time consum-ing process and the derivation of complete 3D models requires multiple scans with each scan having its own coordinate system. Therefore, the different scans should be aligned in a common coordinate system. This alignment process is known as “registration”. Current registration techniques require large overlap area between the collected scans in order to obtain reliable estimation of the transformation parameters relating these scans. The main objective of this research is to avoid the requirement of large overlap areas among the laser scans using photogrammetric data for the registration process. Registration methods generally use points as primitives to relate the different laser scans. In this research, photogrammetric linear and planar features are used for the proposed registration method. Finally, qualitative and quantitative quality control measures are proposed for analyzing the result of the proposed registration method.
Hyporheic temperature patterns within riffles

This paper outlines the results of a pilot study using data at 12 min intervals from 20 miniature temperature dataloggers to establish vertical and longitudinal temperature patterns within a river bed. Data are presented from two adjacent riffles immediately below the Blithfield Reservoir on the River Blithe, Staffordshire, UK, for a five day period in July 1994. Hyporheic temperatures were warmer than those of groundwater, colder than those of surface water and decreased with depth into the river bed. At the heads of the riffles shallow sites (20 cm depth) mirrored surface temperature patterns but were on average 1.53°C cooler while deeper sites (40 cm depth) were 2.60°C cooler on average. Hyporheic temperatures lagged behind the surface water pattern and lag times increased with depth. Sites at the riffle tails generally displayed temperature patterns similar to those of the groundwater system: on average, temperatures were 4.32°C cooler than surface water temperatures and showed no significant variation. Hyporheic temperature patterns at the heads of the riffles suggested downwelling surface water, while the tails appeared to be influenced by upwelling groundwater. Both riffles displayed similar hyporheic temperature patterns but riffle 1 was on average 1.22°C warmer per site than riffle 2. Temperature differences between the riffles are attributed to bed form and substratum composition. These factors may have significant ecological implications including rates of organic matter decomposition, invertebrate life cycles and salmonid egg hatching times.
Comparing several genetic algorithm schemes for the calibration of conceptual rainfall-runoff models

Abstract The Genetic Algorithm (GA) is often associated with local search optimisation techniques in the calibration process of Conceptual Rainfall-Runoff Models (CRRMs) (Wang, 1991; Franchini, 1996), i.e. the GA is used for approaching the region encompassing the global solution and then its results are used as a starting point for the local optimizer in the subsequent “fine-tuning” process. However, the GA can be formulated in very many ways. This study analyses various GA structures and their robustness and efficiency. In addition, a sensitivity analysis of the various schemes to their own parameters is performed. The analysis is conducted using an 11-parameter CRRM, called A Distributed Model (ADM), applied to both a theoretical case without model and data errors and two cases of the real world in which there are both model and data errors. Finally, assuming the same role as the GA for the “Pattern Search” (PS) method in a two-step optimisation technique (Hendrickson et al., 1988), the results of the .
Zr-rich garnet and Zr- and Th-rich perovskite from the Polino carbonatite, Italy

Abstract Th- and Zr-bearing perovskite and Zr-rich Ti garnet are described from the Polino calcite carbonatite, Italy. The garnets contain 6.05-7.50 wt. % ZrO2 in cores and up to 15.80 wt. % in rims. Silicon is low in these garnets and substantial Al and Fe 3+ has been assigned to the tetrahedral sites. A strong correlation of Si with Zr from published data suggests the possibility that some Zr may also be tetrahedrally coordinated. However, the chemistry alone does not constrain the site distribution of Fe, Ti, Zr and Mg unambiguously. The perovskites are very unusual in containing 2.81-3.27 wt. % ZrO2 and 1.48-1.71 wt. % ThO2. For comparison, new analyses are presented of the zirconium garnet kimzeyite and coexisting perovskite from the type locality at Magnet Cove.
Chlorine 36 in Great Basin Waters: Revisited

Inspired by recently published chloride balance chronologies of closed-basin lakes in the Great Basin, researchers of the early 1960s attempted to estimate residence times of chloride in these lakes using 36Cl. Unfortunately, the analytical methods of the period were not capable of measuring the 36Cl levels found in these waters. About 20 years after the early research, advances in accelerator mass spectrometry permitted 36Cl measurement at the required sensitivity. In this study we follow up on those pioneering efforts by remeasuring and reevaluating the 36Cl content at several of the previously studied sites, focusing on Mono Lake in eastern California. Our data show that in general the streams in the region have 36Cl/Cl ratios similar to those expected in present-day atmospheric fallout, but that the terminal lakes into which the streams flow have much lower ratios. These lower ratios could result from either a very long (>1 million years) residence time of the chloride in the basin sinks or from subsurface influx of low-36Cl chloride. In the case of Mono Lake, a mass balance model based on the 36Cl data and on independent estimates of chloride fluxes and reservoirs indicates major subsurface chloride input, presumably from volcanic sources, and an accumulation time in the range of 100–450 kyr. The upper bound of this range is similar to the timing of a shift from long-term humid to arid climate in the region and may indicate that hydrological closure of the basin was triggered by this event.
Interdecadal changes in seasonal freeze and thaw depths in Russia

[1] Seasonal freezing and thawing processes in cold regions play a major role in ecosystem diversity, productivity, and the Arctic hydrological system. Long-term changes in seasonal freeze and thaw depths are also important indicators of climate change. Only sparse historical measurements of seasonal freeze and thaw depths are available for permafrost and seasonally frozen ground regions. Using mean monthly soil temperature data for 1930–1990 for 242 stations located throughout Russia, we employed a linear interpolation method to determine the depth of the 0°C isotherm based on soil temperature data measured between 0.2 m and 3.2 m depth. The relationship between available observed annual maximum freeze and thaw depths and our interpolated values indicates a perfect correlation. A comprehensive evaluation of long-term trends in these new interpolated data for Russia indicates that in permafrost regions, active layer depths have been steadily increasing. In the period 1956–1990 the active layer exhibited a statistically significant deepening by approximately 20 cm. The changes in the seasonally frozen ground areas are even greater: The depth of the freezing layer decreased 34 cm between 1956 and 1990. Potential forcings of the observed changes include air temperature, freezing and thawing index, and snow depth. Correlation and multiple regression reveal that active layer depth is most strongly related to snow depth. Air temperature, both mean annual and thawing index, is also significantly related to changes in the active layer. Freeze depth is influenced most strongly by the freezing index and mean annual air temperature, although snow depth is also a significant contributor. Air temperature and snow depth have been changing less in the seasonally frozen ground regions of Russia compared to permafrost regions, although observed changes in freeze depth are greater than changes in active layer depth for 1930–1990. This indicates that the seasonally frozen ground regions of the Russian high latitudes are more susceptible to climate change than the Russian permafrost. However, as temperatures have been rising, especially in the high-latitude continental regions, both permafrost and seasonally frozen ground regions are being greatly impacted. These changes can potentially result in increased river runoff and changes in discharge throughout the Russian Arctic drainage basin, as well as changes in high-latitude ecosystems.
Effects of snow physical parameters on spectral albedo and bidirectional reflectance of snow surface

Observations of spectral albedo and bidirectional reflectance in the wavelength region of λ = 0.35–2.5 μm were made together with snow pit work on a flat snowfield in eastern Hokkaido, Japan. The effects of snow impurities, density, layer structure, and grain size attained by in situ and laboratory measurements were taken into account in snow models for which spectral albedos were calculated using a multiple-scattering model for the atmosphere-snow system. Comparisons of these theoretical albedos with measured ones suggest that the snow impurities were concentrated at the snow surface by dry fallout of atmospheric aerosols. The optically equivalent snow grain size was found to be of the order of a branch width of dendrites or of a dimension of narrower portion of broken crystals. This size was smaller than both the mean grain size and the effective grain size obtained from micrographs by image processing. The observational results for the bidirectional reflection distribution function (BRDF) normalized by the radiance at the nadir showed that the anisotropic reflection was very significant in the near-infrared region, especially for λ > 1.4 μm, while the visible normalized BRDF (NBRDF) patterns were relatively flat. Comparison of this result with two kinds of theoretical NBRDFs, where one having been calculated using single-scattering parameters by Mie theory and the other using the same parameters except for Henyey-Greenstein (HG) phase function obtained from the same asymmetry factor as in the Mie theory, showed that the observed NBRDF agreed with the theoretical one using the HG phase function rather than with that using the Mie phase function, while the albedos calculated with both phase functions agreed well with each other.
Growth status of school children and adolescents in Ebonyi State, Southeast Nigeria

Background: Growth assessment is useful in monitoring children′s growth. It often reveals their physical characteristics, health and nutritional status, and infers their biological well-being. The present study was conducted to evaluate the physical growth status of schoolchildren and adolescents in Ebonyi State, Southeast Nigeria. Materials and Methods: A cross-sectional study design was followed, which involved a random sampling of 1,620 subjects (849 males and 771 females) selected from schools in urban and rural communities of the state. Anthropometric measurements included height and weight; the body mass index (BMI) was also assessed and the Centers for Disease Control and Prevention (CDC) 2000 reference standards was used for comparison. Results: The median weight values of the urban subjects (males and females) tend to be higher than the CDC reference standard. The median weight of the rural females compared fairly while the rural males deviated below the reference standard at the age of 10-18 years. Compared to the CDC standards, the median height of the urban and rural subjects tends to be higher during childhood; the urban subjects at the age of 15-18 years deviated below the reference standard while the rural subjects deviated below the reference standard from the age of 13 years. The median BMI values of the urban females were higher than the standard; the urban males and rural females were almost identical to the reference chart. In contrast, the median BMI values of the rural males were below the standard. Conclusion: The age-matched increase in the anthropometric parameters evaluated indicates a normal growth pattern, and there was a marked difference in the anthropometric parameters and growth performance of urban schoolchildren and adolescents compared to their rural counterparts. The growth patterns of schoolchildren and adolescents in Ebonyi State appeared comparable to the CDC growth reference charts.
The effects of biogenic silica detritus, zooplankton grazing, and diatom size structure on silicon cycling in the euphotic zone of the eastern equatorial Pacific

Two novel and independent couplings of field data sets suggest that only ~10‐20% of the biogenic silica (bSi) in the surface waters of the eastern equatorial Pacific upwelling zone is associated with living diatoms. Accounting for the ~80‐90% contribution of detrital bSi reconciles discrepancies between estimates of diatom growth rates obtained by different methods. Approximately 50% of the bSi associated with living diatoms was found to be in cells whose greatest linear dimension was > 40 µm. The contribution of that > 40‐µm fraction to bSi production was less than its contribution to biomass, as smaller diatoms, between 10 and 40 µm, contributed 59‐100% of bSi production. A steady‐state model, parameterized using field data, appears to explain the origin of the large detrital bSi pool, relative to the living fraction. Because specific rates of diatom growth are several times higher than those of detrital bSi dissolution, bSi must be predominantly detrital to balance gross rates of silica production and dissolution. Zooplankton grazing is the dominant process creating the detrital bSi pool, and the balance between diatom growth and zooplankton grazing rates maintains a living bSi pool that is a small fraction of the total bSi. Our results show near equivalence between the gross rates of detrital silica production by mesozooplankton grazing and bSi export from the euphotic zone, and also between the rates of detrital silica production by microzooplankton grazing and bSi dissolution, suggesting distinct roles for the two zooplankton size classes in regional Si biogeochemistry.
On the evaluation of ozone depletion potentials

Observations of methane, CFC-11, and ozone losses are used along with insights from models and observations regarding interrelationships between tracers to develop a semi-empirical framework for evaluating global ozone depletion potentials. Direct measurements of some hydrochlorofluorocarbons including HCFC-22 in the Arctic lower stratosphere are also used to evaluate the local ozone depletion potentials there. This approach assumes that all of the observed ozone destruction in the contemporary atmosphere is due to chlorine and that the depletion is proportional to the local relative chlorine release. It is shown that the global ozone depletion potentials for compounds with relatively long stratospheric lifetimes such as HCFC-22 and HCFC-142b are likely to be larger than those generally predicted by gas phase chemical models, due largely to the importance of lower stratospheric ozone losses that are not simulated in gas phase studies. The analysis presented suggests that the globally averaged efficiency for ozone depletion by HCFC-22 is as much as a factor of 2 larger than some gas phase model estimates. For compounds with short stratospheric lifetimes such as (CCl4). and (CH3CCl3), on the other hand, gas phase models likely overestimate the ozone depletion potentials for the present-day stratosphere. Observations of polar ozone loss and reactive halogen radical abundances also imply that the globally averaged ozone depletion potentials for brominated species for the contemporary stratosphere could be as much as 1.5–3 times greater than some gas phase model predictions, depending upon lower stratospheric loss processes.
Analysis of Nonsteady Flow with a Free Surface Using the Finite Element Method

A new iterative, numerical approach to nonsteady flow of groundwater with a free surface using the finite element method has been developed. The method is unconditionally, stable and therefore requires only a small number of time steps to reach the steady state. It can handle problems in which the free surface is discontinuous and portions of the free surface are vertical or nearly vertical. Infiltration or evapotranspiration at the free surface is handled with ease, and the effect of the unsaturated zone can be taken into account indirectly by using the concept of delayed yield from storage. In addition to gravity drainage, the method takes into consideration storage due to the elastic properties of the saturated porous medium. In problems involving flow to a well operating at a prescribed rate, both storage in the well and the actual distribution of velocities along the well bore are taken into account. The method can be applied to a wide variety of problems involving complex boundaries and arbitrary degrees of heterogeneity and anisotropy. Several examples are included to demonstrate some of the features of this new approach.