Miracle-dz/UniFAR-FTUs huggingface dataset:
Preparation and Mechanical Properties of Mg‐Al‐Si‐O‐N Glasses

A three-component glass system (Mg–Al–Si) was nitrided by adding amorphous and crystalline Si3N4. Glasses with varying amounts of nitrogen were melted, and their mechanical properties were measured. Density, hardness, Young's elastic modulus, and fracture toughness increased with increasing nitrogen content.
The Arctic vortex in March 2011: a dynamical perspective

Abstract. Despite the record ozone loss observed in March 2011, dynamical conditions in the Arctic stratosphere were unusual but not unprecedented. Weak planetary wave driving in February preceded cold anomalies in the polar lower stratosphere in March and a relatively late breakup of the Arctic vortex in April. La Nina conditions and the westerly phase of the quasi-biennial oscillation (QBO) were observed in March 2011. Though these conditions are generally associated with a stronger vortex in mid-winter, the respective cold anomalies do not persist through March. Therefore, the La Nina and QBO-westerly conditions cannot explain the observed cold anomalies in March 2011. In contrast, positive sea surface temperature anomalies in the North Pacific may have contributed to the unusually weak tropospheric wave driving and strong Arctic vortex in late winter 2011.
Kinetics of metal extraction in ionic liquids: Eu3+/HNO3//TODGA/[C1C4im][Tf2N] as a case study

The kinetics of metal transfer in the system Eu3+/HNO3//TODGA/[C1C4im][Tf2N], where TODGA is N,N,N′,N′-tetraoctyl diglycolamide, is shown to depend on the chemical conditions (nitric acid and TODGA concentrations) and the time needed to reach equilibrium which may vary from less than 10 min to more than 4 h. At [HNO3] = 4 M, a detailed kinetic study is performed for two different concentrations of TODGA. It is shown that the time required for water and acid solubilisation in the IL phase is very short, as is the time for IL solubilisation in the aqueous phase. By contrast, the extraction of Eu(III) takes more than 100 min to be completed and depends on the TODGA concentration. On the basis of these experimental facts, a simple kinetic model is proposed which is able to account for the data.
Infiltração de água no solo sob escarificação e rotação de culturas

In soils with physical and/or physical hydric restrictions for root growth, it may be a viable strategy to increase crop productivity by increasing water storage potential through improvements in water infiltration. Accordingly, the objective of this study was to determine water infiltration in a Hapludult in three crop rotations under no-tillage, with and without initial chiseling. Crop rotations consisted of: millet/soybean/sorghum/maize/sorghum; millet/soybean/Brachiaria ruziziensis/corn/Brachiaria ruziziensis; and millet/soybean/Brachiaria ruziziensis + castor bean/corn/Brachiaria ruziziensis + castor bean. Water infiltration in soil was evaluated in the field, using concentric discs at the soil surface and at depths of 0.10 and 0.20 m, in 2006 and 2007. After the first year, chiseling led to increased infiltration of water into the soil. Water infiltration was greatest in the crop rotation system with Brachiaria ruziziensis + castor bean. The activity of root systems of crops in the plots without chiseling increased the rate of water infiltration into the soil.
A 3‐D global simulation of the advective transport of passive tracers from various northern hemisphere sources

Two-year transport simulations are performed for passive tracers continuously emitted from Japan, Europe, North America and Amazon regions in order to study transport processes of anthropogenic gases such as CO 2 and halocarbons. Three-dimensional wind data produced by the Meteorological Research Institute global spectral model with rhomboidal 24 truncation and 23 levels are used. Globally, there are three regions within which the transport of tracer is relatively rapid. These are the tropics, and the northern/southern extratropics. Within the tropics, the Pacific and Indian Ocean regions may be considered as further subdivisions. Transports between regions are much slower. In the case of a Japanese source, an equatorward transport occurs mainly in the lower troposphere during winter associated with the Asian winter monsoon circulation. The tracers are advected upward over the equatorial Indian Ocean and transported into the southern hemisphere. A significant seasonal oscillation in tracer density develops in the Antarctic region with the maximum in early June. In the cases of European and North American sources, an equatorward transport is slow and a poleward transport is enhanced in winter. In all cases, transport to the southern extratropics occurs in the upper troposphere because of upward advection in the tropical region. The tracer density increases with altitude in the troposphere in the southern extratropics except over Antarctica. Over Antarctica, the tracer density decreases with altitude and the horizontal distribution is rather uniform at the surface, indicating downward transport of low-density stratospheric air. DOI: 10.1034/j.1600-0889.1993. t01-1-00008.x
Enhanced Photocatalysis of Electrospun Ag−ZnO Heterostructured Nanofibers

A unique dimer-type heterostructure of Ag−ZnO nanofibers with a diameter of 80−150 nm and coupled Ag nanoparticles in the size range from several to 15 nm have been fabricated by a facile electrospinning method. Rhodamine B (RhB) was employed as a representative dye pollutant to evaluate the ultraviolet (UV) photocatalytic activity of Ag−ZnO nanofibers. It was found that the heterojunction structure promoted the charge separation as well as the photon efficiency, allowing both the photogenerated electrons and holes to participate in the overall photocatalytic reaction. The optimal photocatalytic activity of Ag−ZnO nanofibers exceeded that of pure ZnO nanofibers by a factor of more than 25. A possible mechanism for the enhanced photocatalytic activity of ZnO by Ag was proposed.
Impact of Organic Loads and Environmental Gradients on Microphytobenthos and Meiofaunal Distribution in a Coastal Lagoon

The impact of organic loads and environmental gradients on spatial and temporal distribution of microphytobenthos and meiofauna was investigated in the Lesina Lagoon. This system was characterised by high organic matter contents (mostly composed of carbohydrates 60–70%). which decreased from the marine to the continental sector of the lagoon and influenced the meiofaunal distribution and abundance. Both meiofaunal abundance (638–6328 ind. 10 cm−2) and microphytobenthos density and biomass (43–1031 × 103 cells cm−3 and 24.43–591.12 μgC cm−3, respectively) displayed a wide spatial and temporal variability, more evident for microphytobenthos than for meiofauna. Our study suggests that, in the Lesina lagoon, meiofaunal abundance was reduced by sediment organic matter accumulation, but was not affected by salinity gradients, which conversely influenced microphytobenthos distribution.
Intrinsic error in the air‐sea CO2 exchange coefficient resulting from the use of satellite wind speeds

This paper is aimed at justifying the use of satellite wind speed measurements for the determination of the carbon dioxide exchange coefficient at the air–sea interface. We relate it to the wind speed using a relationship determined by Liss and Merlivat, which enables us to monitor the spatio-temporal variations of the CO 2 exchange coefficient on a global scale, using satellite measurements of the wind speed. Yet these measurements integrate the wind speed over areas having a diameter ranging from 25 to 100 km. Moreover, a satellite has a global coverage only after a few days and samples a given place every few days (usually 3 days). We simulate the spatial integration and temporal sampling of spacecraft measurements from in-situ wind speed measurements to infer the errors induced. While the space integration results in a negligible error (a few tenths of cm h -1 at most), a caveat should be given about the sampling error. It is of the order of the statistical error of a normal distribution, depending on the standard deviation and number of measurements. An example of the statistical error resulting from the use of 1 month of SEASAT scatterometer data is shown. Provided this caution about the statistical error is kept in mind and the space and time integration is properly chosen, satellite data, after careful validation of the wind speed retrieval, are well suited for long-term global survey of the CO 2 exchange coefficient space and time variations. The use of a relationship between the exchange coefficient and the wind speed, which accuracy is presently discussed, is the only way to access these variations. DOI: 10.1034/j.1600-0889.1991. 00016.x
Comparative study of the major components of the indigo dye obtained from Strobilanthes flaccidifolius Nees. and Indigofera tinctoria Linn.

Investigation on the chemical constituents including the chemical structure of major components in the water extracts from Strobilanthes flaccidifolius Nees. and Indigofera tinctoria Linn. was done. It was found that the indigo from fresh leaves of S. flaccidifolius Nees. fermented for three days gave the highest amount of indigo. The thin layer chromatography of the crude extract revealed four pigments; the major pigments were of red and blue having Rf values of 0.88 and 0.76, respectively. The Rf value, the maximum absorption from UV-Visible spectroscopy and infra red spectrum of blue pigment were the same as those of the standard indigo. Both blue and red pigments are highly soluble in chloroform whereas only red pigment is soluble in methanol.
Extraction Behavior of Mo(VI) and W(VI) as Homologs of Sg with α‐Benzoinoxime

Solvent extraction of molybdenum and tungsten as homologues of Sg with α‐benzoinoxime from HCl solutions has been investigated. The extraction equilibration was achieved at 20s for Mo and W. Molybdenum was almost quantitatively extracted from 0.001 to 4 M HCl solutions, and the extraction yields decreased at higher and lower acid concentrations due to the formation of anionic oxychloride complex and anionic species MO4 2−, respectively. The extraction yield of W was lower than that of Mo during the whole range of acid concentration. The composition of the extracted species was determined by using the slope method in present experiment. The elemental analysis, IR and 1H NMR spectra of the extracted species suggest that the extracted complex contain one MoO2 2+ or WO2 2+ groups bonded with two α‐benzoinoxime molecules.
CRITICAL HEAT FLUX AND SUBCOOLED NUCLEATE BOILING IN TRANSIENT REGION BETWEEN A TWO-DIMENSIONAL WATER JET AND A HEATED SURFACE

The present paper is concerned with a high subcooling water jet boiling system at the stagnation point. The purpose of the investigation is to obtain a high heat flux and to reveal the high heat flux mechanism. Most of the discussion in this paper is based on experimental results and concerns the effect of subcooling, jet velocity, and stagnation pressure on critical heat flux and nucleate boiling in the transient region. The entire range of the boiling curve is divided into three heat transfer regions which may be hypothesized to exist in nucleate boiling.
Sound emission from open turbulent premixed flames

A study of the noise produced by turbulent premixed flames stabilized on open burners is described. It is shown that such flames may be represented acoustically as a collection of monopole sound sources in the combustion zone. The radiated sound pressure is dependent on the rate of change of the rate of increase of volume of the gas during combustion, which varies owing to the turbulence in the flow. The rate of volume increase is proportional to the rate of consumption of combustible gas mixture in the flame. To measure this quantity, an optical technique has been developed which relies on observations of changes in the intensity of emission from the free radicals C2 or CH generated in the reaction zone. Good quantitative agreement is obtained between the radiated sound pressures calculated from these intensity measurements and the values recorded simultaneously with a microphone. A correlation observed between the mean emission intensities of C2 and CH radicals and the total flow rate of combustible gas mixture both in the laminar and turbulent flames, and in their transition region, supports the wrinkled laminar flame concept of turbulent flame propagation.
Effect of chemical potential on the computer simulation of hydrogen storage in single walled carbon nanotubes

Grand canonical Monte Carlo molecular simulations were carried out for hydrogen adsorption in single-walled carbon nanotubes. It was found that variations in chemical potential may result in a great change in the hydrogen storage capacity of single-walled carbon nanotubes. Hydrogen adsorption isotherms of single-walled carbon nanotubes at 298.15 K were calculated using a modified chemical potential, and the result obtained is closer to the experimental results. By comparing the experimental and simulation results, it is proposed that chemical adsorption may exist for hydrogen adsorption in single-walled carbon nanotubes.
Experimental and Numerical Investigation of Laminar Hydrogen-c

Abstract Flame structure measurements, made using UV Raman scattering and OH laser induced predissociative fluorescence (LIPF), are compared to one dimensional (ID) numerical simulations. Three low stretch (far from extinction) flame conditions are measured: 1) 20%H2 + 80% N2 vs. air, a = 133s−1’; 2) 50%H2 + 50%N2 vs. air, a=125s−1; 3) 100% H2 vs. air, a = 100s−1. Comparisons of major species measurements with the 1D simulations are in excellent agreement for all cases. Measurements of OH in the 100% H2 flame are slightly lower than the numerical predictions. However, considering spatial averaging and measurement uncertainty due to OH calibration, the OH measurements are in good agreement with the numerical simulations. Mixture fraction measurements (based on atomic nitrogen and atomic hydrogen) agree with the numerical simulations and indicate that differential diffusion effects are important in flames where the primary reaction zone is in a region of low conveclive velocity (e.g., the vicinity of the st.
Carbonaceous microspheres prepared by hydrothermal carbonization of glucose for direct use in catalytic dehydration of fructose

A carbonaceous microsphere material was prepared by hydrothermal carbonization (HTC) of glucose, and was used directly for the catalytic dehydration of fructose into 5-HMF without any in situ functionalization or post-modification. The prepared material was found to be a good solid acid catalyst for the production of 5-HMF from fructose in ionic liquid 1-butyl-3-methylimidazolium chloride ([BMIM][Cl]), where a 5-HMF yield of 88.1% was obtained at 100 °C for 90 min reaction time, which is due to the contribution of the –COOH groups in the catalyst. It is the first time that a HTC material is reported in the efficient catalytic conversion of biomass without any in situ functionalization or post-modification. In addition, the catalytic system was shown to be applicable to higher fructose concentrations up to ca. 10 wt%. The HTC material catalyst exhibited constant activity for five successive reuses.
NUCLEOPHILIC REACTIVITY OF CHITOSAN IN IONIC LIQUIDS PROMOTED BY TERT-AMINES

group is a result of the cyclization shown in Scheme 1. The presence of all these peaks confirms that both -OH and -NH2 of the chitosan anhydroglucose unit reacted with PA. The FTIR spectra for the reaction of chitosan with PA in the presence of pyridine or DABCO using BMIMAc as a solvent are presented in Figure 1. It can be observed that in the presence of DABCO the absorption intensities are greater than observed using pyridine. Both resulting products are soluble in DMSO. When the films used for the FTIR were heated to 200 0
SOLAR WATER DISINFECTION UNDER REAL CONDITIONS WITH OR WITHOUT SOLAR COLLECTOR

Solar Water Disinfection (SODIS) is a simple, environmentally sustainable, low-cost solution for drinking water treatment at household level for people consuming microbiologically contaminated water. In the present work, inactivation kinetics of Escherichia coli suspension was studied using PET bottles with different backing surfaces (transmissive and absorptive) and Compound Parabolic Collector (CPC) under real, solar radiation (cloudy and cloudless) conditions. Use of CPCs considerably reduced the time required for complete inactivation of E. coli. Its use would be particularly advantageous during cloudy conditions. Another test for comparing inactivation kinetics of E. coli in tap water with that in distilled water indicated that inactivation rate of E. coli was slightly faster in tap water compared to distilled water due to the presence of natural materials present in tap water. Black painting would especially be advantageous under cloudy conditions when one day exposure would not be enough for complete inactivation of bacteria. The results of the study thus indicates that solar water disinfection is a promising technology for treatment of microbiologically contaminated water in rural areas of developing countries, needing continued development.
Diffusons, locons and propagons: Character of atomie yibrations in amorphous Si

Abstract Numerical studies of amorphous Si show that the lowest 4% of vibrational modes are piane wave like (‘propagons’) and the highest 3% of modes are localized (‘locons’). The rest are neither piane wave like nor localized. We cali them ‘diffusons’. Since diffusons are by far the most numerous, we try to characterize them by calculating such properties as the wave-vector and polarization (which do not seem to be useful), ‘phase auotient’ (a measure of the change of vibrational phase between first-neighbour atoms), spadal polarization memory and diffusivity. Localized states are characterized by finding decay lengths, inverse participation ratios and coordination numbers of the participating atoms.
Selective Sulphide Precipitation of Heavy Metals from Acidic Polymetallic Aqueous Solution by Thioacetamide

The selective separation and recovery of copper, cadmium, zinc, and nickel from a polymetallic solution with sulphide precipitation using thioacetamide have been investigated. Selective metal sulphide precipitation was studied as a function of pH, contact time, and temperature. The results showed that it was possible to separate metals by accurately controlling the pH and temperature. Below pH 2.5, copper precipitation was complete. The cadmium, zinc, and nickel selective precipitations were performed at pH of 4, 5.5, and 7.5, respectively. Temperature also had important effects on the selective separation, and metals precipitation yields increased with increasing temperature. Thioacetamide hydrolysis kinetics and its activation energies in various conditions were calculated. The metal sulphide precipitates were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the results showed that the produced precipitates had high purity.
PHYSICO-CHEMICAL CHANGES IN SOIL DUE TO SULPHURIC ACID CONTAMINATION

Acid contamination of soil can adversely affect the geotechnical properties of soil even at low concentrations. The effect of sulphuric acid contamination (0-15%) on the behavior of three types of soils viz., black cotton soil, a dispersive soil called Suddha soil and a red loamy soil with varied clay content has been studied. Specific surface of all the soils decrease due to acid contamination. The liquid limit decreased for all the three soils with increase in sulphuric acid concentration generally due to increase in electrolyte concentration of the pore fluid and consequent decrease in the thickness of double layer developed. This indicates the reduction in water holding capacity and increase in the frictional resistance and decrease in cohesion in soil. With increase in acid concentration the cation exchange capacity of soils decreases. There is a decrease in the optimum moisture content of soils. Unconfined compressive strength has significantly reduced due to loss of cohesion.
Montmorillonite-asulam interactions: I. Catalytic decomposition of asulam adsorbed on H- and Al-Clay

Abstract The adsorption of the Asulam herbicide (4-aminobenzensulphonyl-methyl-carbamate) by Al- and H-montmorillonite has been studied by IR spectroscopy, thin layer chromatography and chemical analysis. This compound is adsorbed from CCl4 solution at room temperature through protonation of the NH2 functional group by the ‘acidic’ water coordinated to the interlayer cation of the clay. After heating the complex at 75°C for 20 h, a hydrogen-bond between the C=O group of the Asulam and the water is established and the organic molecule decomposes to sulphanilic and carbamic acids. If the complex is equilibrated at 100% relative humidity, the carbamic acid becomes unstable, and the IR spectrum shows only the bands typical of the acidic montmorillonite-sulphanilic acid complex. The catalytic properties of the clay surface are demonstrated by comparison with the transformations occuring in the organic molecule on heating in concentrated mineral acids.
Electric field breakdown at micrometre separations in air and nitrogen at atmospheric pressure

For efficient operation, micromotors and microactuators, such as those employed in microsystems, are required to operate with high electric fields at electrode separations of the order of micrometres. An apparatus was built to accurately measure the breakdown voltage for electrode spacings as low as 0.5 µm. Breakdown voltage measurements in air and nitrogen are presented and discussed for the gap range 0.5 to 15 µm. Energy dispersive analysis of X-rays (EDAX) confirms the transfer of material from cathode to anode and vice versa during the breakdown mechanism. The Paschen law has been confirmed not to be applicable at gap settings of less than 4 µm. The shape of the curve and the breakdown voltage values are found to be the same for different gases and different high pressures up to 4 µm separation. Below this value, an analytical explanation of the breakdown voltage based on quantum tunnelling of electrons is obtained in terms of electrical field enhancement at microprotrusions and the work function of the electrode material.
Mineralogy of red- and yellow-colored soils from Thailand

Samples from profiles of 14 Ultisols, 2 Oxisols, and 1 Inceptisol from Thailand have been investigated for mineralogy and some chemical and physical characteristics. The soils were generally strongly acid in reaction with pHKC1 values at around 4, with the exception of profile T-13 which was nearly neutral with relatively large amounts of exchangeable Ca and Mg. Organic matter content was low in general (<0.5% of fine-earth), except for some surface horizon samples (1-6%). Particle-size distribution varied widely with profiles depending apparently on the type of parent materials, and also with the depth of horizons within each profile probably as a result of eluviation and illuviation, as well as loss by surface runoff, of the clay materials. Jn general, the soils derived from old alluvium were sandy, those from granitic rocks were moderately so, and those from basaltic rocks and mixed residuum and colluvium were clayey, in texture. It was noted also that the silt content was generally very low as compare.