Miracle-dz/UniFAR-FTUs huggingface dataset:
Adsorption and desorption of indifferent ions in variable charge subsoils: The possible effect of particle interactions on the counter-ion charge density

The relationship between soil solution ionic strength (IS) and the surface or counter-ion charge density (CICD) is well described by the double layer theory. However, the magnitude of the counter-ion charge may be affected by phenomena that are likely to occur in variable charge subsoils, and research to investigate the extent of indifferent ion sorption as a function of IS is certainly needed. The objective was to study adsorption and desorption of ions in batch and column experiments, and to propose a mechanism that describes best the experimental observations in subsoils from the southeastern USA. Results showed that the cation and anion of an electrolyte were simultaneously adsorbed in approximately equivalent amounts with no net release of other ions into the soil solution. Ions were adsorbed in the Stern and diffuse layers of oppositely charged colloids since the subsoil was treated with dilute solutions. They were immediately displaced when the subsoil was washed with distilled water (dH 2 O), confirming the reversible nature of this phenomenon. Three different magnitudes of the CICD were observed at similar IS values. The surface charge density on negatively and positively charged soil particles may not be equal to the CICD in dilute soil solutions, and other mechanisms may operate to balance the surface particle charges. It is possible that a portion of the surface charge may be balanced as a result of the interactions among oppositely charged soil particles when their diffuse layers extend and overlap, or compress and separate in response to IS changes.
Plasma diagnostic by emission spectroscopy during vacuum arc remelting

The plasma produced during vacuum arc remelting of a Zircaloy4 electrode has been investigated by optical emission spectroscopy. Spatial variations of plasma emission along the arc axis has been measured with a specific apparatus consisting of nine aligned optic fibres. The plasma consists of zirconium atoms, of singly and doubly charged zirconium ions and of chromium atoms. The non-observation of emissions of tin and iron particles, which are, with chromium, the three main alloy components of Zircaloy4, suggests that the concentrations of these two species in the plasma are negligibly small. Distribution temperatures of atomic and ionic species of the order of 1 eV and high ionization degree of the plasma (greater than 70%) have been determined. The similar decay of the line intensities of the various species with increasing axial distance from the cathode surface indicates that the plasma composition remains approximately unchanged within the interelectrode region. Synthesis of the spectroscopic results has shown that the emission of vapour into the plasma cannot be accounted for by a mechanism of metal volatilization from the cathodic and anodic liquid surfaces only. It also involves emission mechanisms occurring in the cathode spot region, like the expulsion of metal droplets which volatilize or the ejection of particles.
Ab initio molecular dynamics study of adsorption sites on the (001) surfaces of 1:1 dioctahedral clay minerals

Ab initio molecular dynamics room-temperature simulations and full relaxation of atomic positions are performed in the study of adsorption sites on the octahedral and tetrahedral surfaces (parallel to the (001) plane) of the kaolinite group of clay minerals. Interactions of water and acetic acid molecules with both surfaces are investigated. Simulations showed that both polar molecules are strongly bound to the octahedral surface forming several simultaneous hydrogen bonds. Surface hydroxyl groups located at the octahedral surface act as proton donors as well as proton acceptors demonstrating their amphoteric character. Moreover, proton jumps between the carboxyl group of acetic acid and one surface hydroxyl group were observed in the molecular dynamics simulations. On the other hand, both molecules interact only very weakly with the tetrahedral side of the kaolinite layer showing the hydrophobicity of this surface. The octahedral surface is hydrophilic.
Na effects on CuInSe2: Distinguishing bulk from surface phenomena

The effect of sodium on the performance of CuInSe2-based solar cells has been under discussion for already a decade. We present experimental evidence using secondary ion mass spectroscopy, x-ray photoelectron spectroscopy (XPS) and other, complementary physical characterization methods, which indicate that, after exposure to an external Na source, no significant amounts of sodium, beyond the residual amount, found in as-grown samples, enter intact crystals, except via defects such as grain boundaries. However, after such exposure, sodium is found in significant concentrations on crystal surfaces, something that is accompanied by an increase in oxygen concentration, as judged by XPS. As expected metallic Na attacks the crystals and can destroy them or at least introduce significant defect densities. Adding Se0 is found, via Na2Se formation, to temper Na activity specifically its effects on crystal disintegration. This is different from the effect of Se0 along where annealing (of n-type) crystals results in.
Thermodynamic calculation of phase equilibria in the CaF2-SiO2-CaO system

Thermodynamic properties of intermediate phases and melts of the system CaF2–SiO2–CaO, found experimentally, have been applied to computation of phase equilibria. Four intermediate phases CaO·SiO2, 3CaO·SiO2, 3CaO·2SiO2, 2CaO·SiO2 and two deep eutectics at T= 1717 K, XSiO2= 0.635 and T= 1723 K, XSiO2= 0.445 situated on either side of CaO·SiO2 exist in the binary system CaO–SiO2. The CaF2–CaO binary system has a simple eutectic diagram with the eutectic point at T = 1631 K and XCaO= 0.198. Isotherms of the CaF2–SiO2-CaO phase diagrams were calculated at 1473, 1573, 1700, 1773 and 1823 K. Four pseudobinary joins in the CaF2–SiO2–CaO phase diagram were also computed. A large region of liquid immiscibility is predicted to exist in the system and confirmed experimentally. One liquid phase is composed of almost pure CaF2 with additions of several mol% CaO and SiO2, and the other contains 56–70 mol% CaF2. There are five invariant points in the CaF2–SiO2–CaO system, four of them being ternary eutectics and one being a ternary peritectic. The primary phase fields of crystallization of all the phases are elongated toward the CaF2 apex; those of the end-member components are the widest, and those of the compounds 3CaO·SiO2 and 3CaO·2SiO2 are the narrowest. Experiments were carried out to confirm the reliability of the locations of the computed phase equilibria boundaries.
Distribuição espacial da precipitação e da erosividade da chuva mensal e anual no Estado do Espírito Santo

The mapping of rainfall erosivity and rainfall is a practical and indispensable tool to plan the soil and water management on a regional scale, such as countries, states or basins. The purpose of this study was to analyze the spatial continuity of erosive potential of rainfall and rainfall, considering monthly and annual mean values, and to map them for the State of Espirito Santo, Brazil, providing basic information for the planning of sustainable soil use and management. To this end, 129 weather stations were used and monthly values of rainfall erosivity were calculated using Fournier's equations. A strong spatial dependency structure was observed, especially for rainfall erosivity, with data fitting to the exponential semivariogram model. For rainfall, the spatial dependence degree values were slightly lower than for rainfall erosivity, however, a moderate to strong spatial dependence degree was obtained. The rainfall erosivity potential of the Rio Doce region was classified as "strong" and "very strong", varying from 7,000 to 11,460 MJ mm ha-1 h-1 year-1. In this region, the natural vulnerability to water erosion of soils with a dissected relief, low natural fertility and a pronounced water deficit hampering vegetation establishment, is higher.
Biomass yield and phosphorus availability to wheat grown on high phosphorus soils amended with phosphate inactivating residues. II. Iron rich residue

Reducing the environmental risk from soluble phosphorus (P) in long-term poultry manured fields can involve increased use of chemical soil amendments such as aluminum (Al), calcium (Ca), and iron (Fe). Iron salts have been proven effective in removing soluble P from wastewater and have been used to inactivate P in poultry litter and litter-amended soils. The potential for P deficiency in crops grown on Fe treated soils is of concern. A growth chamber experiment was conducted using Matapeake, Evesboro, and Woodstown soils with Mehlich 3 extractable P (M3-P) levels above 800 mg kg−1 in order to 1) determine the effects of a Fe-rich residue (IRR) on crop biomass yield and on plant P, Mn, and Fe contents, and 2) examine pH, electrical conductivity (EC), P, Mn, and Fe concentrations in soils after three cropping cycles with wheat. IRR was mixed with the soils at rates of 0, 10, 25, and 50 g kg−1 and incubated for seven weeks. Three crops of wheat (Triticum aestivum) were grown in succession. Biomass yield (BM) and tissue P concentrations were significantly reduced with the additions of IRR for all three soils, but the differences were much less at the 10 g kg−1 application rate than at the 25 and 50 g kg−1 rates. Biomass yield was 29% lower than the control at the 10 g kg−1 IRR rate compared to 74% lower at the 50 g kg−1 rate. Even though tissue P concentrations were reduced, levels were within the range considered sufficient for wheat growth for all treatments. The high Mn and DTPA-Fe in the IRR treatments increased tissue Mn and Fe concentrations, but the levels were below the concentration considered to be toxic to most crops. Water soluble P and M3-P concentrations were lowered with increased IRR application rate for each soil and correlated positively with tissue P for the three soils. DTPA extractable Mn concentrations in soil increased, but Fe concentrations decreased with increased IRR application, for the three soils. IRR treatments initially increased both pH and EC in the three soils, however, reductions in pH and EC values were found with subsequent cropping cycles. Further studies to identify and limit the negative impact of IRR on plant growth are needed before the materials should be considered for field application to sequester soluble P in high P soils.
Do Investment Climate Deficiencies Explain Low Manufacturing Productivity in Developing Countries? An Application to the Middle

Drawing on the World Bank enterprise surveys, this paper shows that the investment climate (IC) is correlated with firms’ technical efficiency (TE) in eight manufacturing industries of 22 developing countries. Essential aspects of the investment climate include the quality of infrastructure, the experience and education of the labor force, the cost of and access to financing, as well as different dimensions of government-business relations. The empirical analysis also illustrates that the deficient IC in many countries in the Middle East and North Africa (MENA) is associated with low TE. The exception is Morocco, and to some extent Saudi Arabia, where the IC and TE rank close to that of the most efficient economies of the empirical sample. The paper also highlights that industries more exposed to international competition, as well as small and medium domestic firms in some branches, exhibit a higher sensitivity to IC limitations.
Impact of Land-Use Changes on Soil Hydraulic Properties of Calcaric Regosols on the Loess Plateau, NW China

Vegetation restoration efforts (planting trees and grass) have been effective in controlling soil erosion on the Loess Plateau (NW China). Shifts in land cover result in modifications of soil properties. Yet, whether the hydraulic properties have also been improved by vegetation restoration is still not clear. The objective of this paper was to understand how vegetation restoration alters soil structure and related soil hydraulic properties such as permeability and soil water storage capacity. Three adjacent sites with similar soil texture, soil type, and topography, but different land cover (black locust forest, grassland, and cropland) were selected in a typical small catchment in the middle reaches of the Yellow River (Loess Plateau). Seasonal variation of soil hydraulic properties in topsoil and subsoil were examined. Our study revealed that land-use type had a significant impact on field-saturated, near-saturated hydraulic conductivity, and soil water characteristics. Specifically, conversion from cropland to grass or forests promotes infiltration capacity as a result of increased saturated hydraulic conductivity, air capacity, and macroporosity. Moreover, conversion from cropland to forest tends to promote the creation of mesopores, which increase soil water-storage capacity. Tillage of cropland created temporarily well-structured topsoil but compacted subsoil as indicated by low subsoil saturated hydraulic conductivity, air capacity, and plant-available water capacity. No impact of land cover conversion on unsaturated hydraulic conductivities at suction > 300 cm was found indicating that changes in land cover do not affect functional meso- and microporosity. Our work demonstrates that changes in soil hydraulic properties resulting from soil conservation efforts need to be considered when soil conservation measures shall be implemented in water-limited regions. For ensuring the sustainability of such measures, the impact of soil conversion on water resources and hydrological processes needs to be further investigated.
Perpendicular magnetic anisotropy and magnetostriction of sputtered Co/Pd and Co/Pt multilayered films

Magnetic properties of Co/Pd and Co/Pt multilayers were studied as a function of sputtering gas pressure. It was found that the magnetic properties of the films depended upon the sputtering gas pressure, and large coercivity (several kOe) and a perfect squareness of the perpendicular hysteresis loop were attained by the deposition at the high gas pressure. These multilayers are suitable for perpendicular magnetic recording media. In the Co/Pd, the origin of the perpendicular magnetic anisotropy is mainly an interfacial anisotropy, although there exists a stress‐induced anisotropy for the films with the relatively short periodicity. The perpendicular magnetic anisotropy of the Co/Pt can be concerned with the Co‐Pt mixture formed at the interface of the multilayer structure. The magnetostriction of the Co/Pd films with the relatively short periodicity is extraordinarily large with a negative sign, since Co atoms adjacent to Pd atoms at the interface could induce larger magnetostriction than that of pure Co.
Sweet Potato Root and Biomass Production with and without Nitrogen Fertilization

Previous work suggests that some sweet potato (, L.) cultivars can produce high storage root yields on soils without fertilizer N addition. This study was conducted to compare storage root yields, total biomass, N uptake and fibrous root weights of sweet potato cultivars grown on low N level soils with and without N addition. In 1987 and 1988, improved sweet potato cultivars developed at International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria were grown with and without 50 kg N ha in Oxic Paleustalfs with low N and C concentrations. Yields of 21 to 38 Mg ha were produced for four of the five improved cultivars grown in soil without N addition. Total biomass, foliage, fibrous root and storage root weights and N concentration in leaves were not influenced by fertilizer N addition. Up to 158 and 89 kg N ha uptake in total biomass occurred with the +N and −N treatments, respectively. Indigenous soil N levels and fibrous root weights for − N vs. +N treatments could not account for the total N uptake and biomass produced on soils without N addition.
Inductively Coupled Plasma Mass Spectrometry (ICP-MS) Determination of Metals and Metalloids in Marine Sediments. Evaluation of the Contamination Levels in Tenerife Island

Metals and metalloids are usually bound in the fine-grained (<63 µm) fraction of the marine sediments, due to the high surface area and humus content. In this fraction, the metals have a greater biological availability than in the coarser fractions. In the present work, the content of total metals and metalloids, their distribution and accumulation in marine sediments collected in the Tenerife Island (Spain) was evaluated. Thirty-six samples collected near the nine points of discharge located along the entire coast were analyzed. The concentration of 47 elements was determined by microwave-assisted digestion followed by Inductively Coupled Plasma Mass Spectrometry (MAE-ICP-MS) analysis. Important levels of contamination from a high number of elements were found in samples, the concentrations of Pb was higher than the ecotoxicological assessment criteria (EAC) established by the OSPAR (5 mg kg−1) in some cases. Principal component and correlation analysis were developed and the results obtained indicated that there are two principal sources of anthropogenic pollution, with a large number of elements related to them. The amounts of 13 elements found in the sediments of the sampling point of Santa Cruz of Tenerife, principal city of the island, were higher than those found in the other locations. Modifications in the sea bed were also detected due to industrial wastes; concentrations of metals related to metallurgic activities have increased in the industrial area while the proportion of original igneous sediments decreased. The mobility of the pollutants, according to the sea currents, was also evaluated. For some of the analyzed metals, differences between sampling points in agreement with the direction of the marine currents in the area were obtained. The large number of elements analyzed allowed the development of a geochemical characterization of the three slopes of the island. Significant differences were observed for some elements.
Rheological Properties of Reconstituted Hot Salep Beverage

Abstract In this study, some physicochemical (solubility index, apparent density and dry matter content) and rheological properties of the hot salep, an indigenous Turkish beverage, were determined. The samples were prepared by adding water or milk to the commerical instant salep powder. The apparent viscosity of samples was measured in the temperature range of 10–50 °C, with the rotational speed of 20–200 rpm. The empirical power law model was used for the determination of the flow behavior and consistency indices of the samples. Dry matter content and apparent density of salp-milk beverage were significantly (p < 0.05) higher than those of salep-water counterpart. Apparent viscosity, consistency and flow behavior indices were also higher in the salep-milk samples. Salep-water sample was more pseudoplastic with lower flow behavior index. Since there is a close relationship between the rehological properties of beverages and consumer preference, the results might be useful in the formulation of instant hot salep beverages.
Micronutrient Soil-Test Levels and Eucalyptus Foliar Contents

Eucalyptus is the most widely planted forest species in Brazil (∼3.4 million hectares). Ongoing rotations and high yields lead to the occurrence of copper (Cu), manganese (Mn), iron (Fe), and zinc (Zn) deficiency symptoms. The objectives of this work were to identify the most appropriate extractant for evaluating micronutrient availability in commercial Eucalyptus plantations and to evaluate the influence of soil properties on Eucalyptus foliar micronutrient contents. Soil micronutrient contents were extracted by Mehlich 1, Mehlich 3, and diethylenetriaminepentaacetic acid (DTPA). Mehlich 1 and Mehlich 3 extracted the greatest amounts for all micronutrients analyzed. Foliar Cu, Mn, and Zn contents showed significant and positive relationships with soil Cu, Mn, and Zn contents extracted by the three solutions. Soil organic carbon (SOC), soil clay content, and soil pH improved significantly the power of regression models in estimating foliar micronutrient contents. The improvement was greater for Mehlich 3 and DTPA extractants than for Mehlich 1.
Feasibility study of long-term continuous field measurement of soil redox potential

An in situ and continuous redox potential measurement protocol for soils and groundwater was optimized, as part of a research that assays the redox potential changes in recharge basin soils during wastewater reclamation using the Soil Aquifer Treatment (SAT). The results show that it is possible to measure continuously and reliably the redox potential in the soil profile of the recharge basins and in the groundwater by using a combined Pt‖Ag|AgCl cell (electrode), a specialized interface, and a portable data-logger. Redox potential values measured before true local equilibration of the electrodes was reached are interpreted as “mixed-potentials” strongly biased by the presence of oxygen near the electrode. Uninterrupted and non-disturbing measurements were carried out in the field for relatively long periods (few days to few weeks) giving reliable information on the temporal cycling of the redox potential in the soil profile during wastewater recharge cycles. The method was found to be dependable, non-expensive and easy to apply.
Experimental and theoretical XANES and EXAFS study of tetra-ferriphlogopite

Experimental and theoretical EXAFS and XANES data on Fe coordination and bond distances have been obtained for a natural tetra-ferriphlogopite. XANES data show a predominance of trivalent iron in tetrahedral coordination. The use of theoretical multiple scattering calculations helps distinguish the contributions to the total spectrum coming from the different iron atoms. EXAFS spectra were reduced and analyzed using the GNXAS programs and Fe has been confirmed to be in tetrahedral coordination, with refined structural data Fe-O = 1.86 A, Fe-Si = 3.24 A, Fe-O-Si = 138°. Moreover, a further contribution from Fe is detected corresponding to a Fe-O distance equal to 2.22 A. This latter contribution (20 mol % of the total Fe ca. ) is interpreted to arise from divalent Fe in octahedral coordination, in excellent agreement with the structural and chemical data.
Effects of thermal rippling on the frictional properties of free-standing graphene

With use of simulated friction force microscopy, we study the effect of varying temperature on the frictional properties of suspended graphene. In contrast with the theory of thermally activated friction on the surfaces of three-dimensional materials, kinetic friction is demonstrated to both locally increase and decrease with increasing temperature, depending on sample size, scanning tip diameter, scanning rate, and the externally applied normal load. We attribute the observed effects to the thermally excited flexural ripples intrinsically present in graphene, demonstrating a unique case of temperature-dependent dynamic roughness in atomically thin membranes.
Storage stability of cashew apple juice preserved by hot fill and aseptic processes

Cashew (Anacardium occidentale L.) apples from Pacajus, Ceara State, Brazil, were processed into high pulp content juice. The juice was packed either by hot fill or an aseptic process and evaluated for physical, physical-chemical, and sensorial changes during a 12-month storage period at room temperature. The results indicated that pH, soluble solids, total acidity, total sugar content and color did not change significantly during storage nor were affected by the type of filling. The sensorial analysis showed that juice acceptance remained high throughout the storage period regardless of the filling system. Differences in juice viscosity persisted between both processes.