Miracle-dz/UniFAR-FTUs huggingface dataset:
Simulating diffusion within soil aggregates: a simple model for cubic and other regularly shaped aggregates

Summary Diffusion within a cube was simulated by a model which divides the cube into concentric volumes and computes by Fick's first law the diffusive flux between adjacent volumes and between the outermost volume and the external solution. The model can also be applied directly to a sphere and, with minor modifications, to other regular shapes. It was tested in two forms: (a) with the distances between the interfaces of adjacent concentric volumes made equal, and (b) with the volumes themselves equal, by using it to simulate the uptake of solute by a sphere from a stirred solution of limited volume. The output from the latter form of the model agreed the more closely with values obtained from a solution of the diffusion equations in radial co-ordinates, and this form was used subsequently. The model was used successfully to simulate the diffusion of bromide from cubes of chalk and chloride-36 from porous ceramic spheres, and its flexibility was illustrated by its ability to simulate experiments in which aliquots of the external solution were removed for assay.
Hydrogen solubility in silicon and hydrogen defects present after quenching

Boron-doped silicon ((B) approximately 1017 cm-3) was heated in H2 gas at a temperature in the range 900<or=T<or=1300 degrees C and quenched to room temperature. Some of the dissolved hydrogen formed H-B pairs and the remainder (Hh), which was infrared inactive was released during anneals at T<or=200 degrees C leading to an increase in (H-B). The total hydrogen content, consistent with secondary-ion mass spectrometry, yielded a solubility given by SH=9.1*1021 exp(-1.80 eV/kT) cm-3. 2 MeV electron irradiation at room temperature converted Hh into defects incorporating two hydrogen atoms, suggesting that Hh may be present as H2 molecules.
Modulation of NiGe/Ge Contact Resistance by S and P Co-introduction

S and P co-introduced NiGe/Ge (SP-NiGe/Ge) diodes are investigated to reduce the contact resistance Rc of NiGe/n-Ge and to increase the Rc of NiGe/p-Ge to realize metal source/drain Ge n-channel metal–oxide–semiconductor field-effect transistors (nMOSFETs). SP-NiGe/Ge diodes show similar profiles to the mixture of S-introduced NiGe/Ge (S-NiGe/Ge) and P-introduced NiGe/Ge (P-NiGe/Ge) diodes. In SP-NiGe/Ge diodes, not P but S segregation is observed. The lowest Rn/Rp value, where Rn (Rp) is the differential resistance R of NiGe/n-Ge (NiGe/p-Ge) diode, is obtained for NiGe/Ge diodes fabricated at 350 °C. It is revealed that SP-NiGe/Ge diodes can reduce the Rn and increase the Rp more than S-NiGe/Ge and P-NiGe/Ge diodes.
Theory on Orthokinetic Flocculation of Cohesive Sediment: A Review

Investigation on flocculation phenomenon of cohesive fine-grained sediment has been a important part of sediment dynamics. During all of three dynamical factors (i.e., Brownian motion, flow shear and differential settling) that have been verified to play important roles in promoting flocculation of cohesive sediment, the influence of flow shear on sediment flocculation has been paid great attention by many researchers (this flocculation pattern has been termed as “orthokinetic flocculation” in most of published literatures). Among many researches regarding orthokinetic flocculation, the dynamical equation developed by Smoluchowski in 1917 (we called it as Smoluchowski equation hereafter) has been widely adopted as an origin and basement for theoretically analyzing sediment flocculation under a shear flow. Meanwhile, many researchers have also pointed out the deficiencies of Smoluchowski equation (this is because the derivation of Smoluchowski equation was based on six different assumptions), and correspondingly have amended this equation from different aspects. In this paper, we attempt to summarize these results, hopefully providing the theoretical research of sediment orthokinetic flocculation with some references.
Produtividade de duas cultivares de mamona submetidas a diferentes lâminas de irrigação suplementar

This study evaluated the yield, components of production and oil content of two castor bean cultivars through drip irrigation with different water depths. The research was conducted in 2009 in an Oxisol clay in the experimental field in Dourados, Mato Grosso do Sul State. The experimental design was randomized blocks in factorial scheme with five water depths (0, 25, 50, 100 and 150% of evapotranspiration for drip irrigation) in two castor bean cultivars (IAC 2028 and IAC 80) with four replications. The irrigation schedule was predetermined up to two irrigations per week except on rainy days. The increase of irrigation provided significant increase in most components of production and crop yield without changing the oil content of seeds. The application of higher water depth increased yield by 80% in relation to the treatment that received no supplemental irrigation.
Totally Chlorine Free Bleaching of Organosolv Pulps

Abstract Populus tremula* tremuloides wood samples were processed in acetic acid–water–HCl media (Acetosolv pulping) and then subjected to totally chlorine free (TCF) bleaching sequences in order to obtain dissolving grade pulps. Several bleaching sequences (ZEQP1P2, EOQP1P2, EOPaaQP1P2, and EOZQP1P2) were assayed for this purpose. The best results corresponded to an EOZQP1P2 sequence, which led to pulps suitable for the manufacture of viscose and cellulose nitrate.
Hydrolyzed Polyacrylamide/Chromium(III) Acetate Gel Chemistry

Proton NMR and visible spectroscopy are used to investigate the chemistry of hydrolyzed polyacrylamide/chromium acetate gels. Color changes in conjunction with HNMR are used to monitor chromium acetate hydrolysis, and HNMR is used to characterize Polyacrylamide in solution and to monitor increases of free acetate and decreases of polymer backbone proton and amide proton resonances during gel formation. The data indicate that chromium acetate hydrolysis is halted by polymer coordination. The polymer cross-linking reaction appears to be a simple replacement of chromium(III) coordinated acetate groups on the chromium(III) trimer by polymer carboxylate groups.
Thermodynamic analysis on energy densities of batteries

The average increase in the rate of the energy density of secondary batteries has been about 3% in the past 60 years. Obviously, a great breakthrough is needed in order to increase the energy density from the current 210 Wh kg−1 of Li-ion batteries to the ambitious target of 500–700 Wh kg−1 to satisfy application in electrical vehicles. A thermodynamic calculation on the theoretical energy densities of 1172 systems is performed and energy storage mechanisms are discussed, aiming to determine the theoretical and practical limits of storing chemical energy and to screen possible systems. Among all calculated systems, the Li/F2 battery processes the highest energy density and the Li/O2 battery ranks as the second highest, theoretically about ten times higher than current Li-ion batteries. In this paper, energy densities of Li-ion batteries and a comparison of Li, Na, Mg, Al, Zn-based batteries, Li-storage capacities of the electrode materials and conversion reactions for energy storage, in addition to resource and environmental concerns, are analyzed.
Staling of Wheat Bread Stored in Modified Atmosphere

Abstract Modified atmosphere packing (MAP) of bread is known to extend the microbial shelf-life. However, the effect of MAP on staling of bread is more questionable, and conflicting results are reported in the literature. To investigate the effect of MAP, wheat bread was packed in modified atmosphere containing 100% CO 2 and in a mixture gas of 50% CO 2 and 50% N 2 , respectively. The control bread was packed in atmospheric air. No significant effects of MAP were found during storage of bread for 7 days at 20°C compared to control bread, when changes in bread firmness and starch retrogradation measured by differential scanning calorimetry (DSC) were used as parameters for the staling rates. In addition, no significant differences were obtained in firmness between bread stored in 100% CO 2 , and in the mixture gas of CO 2 and N 2 after 7 and 14 days, respectively. The present study thus demonstrated that storage of bread in MAP could be used to extend the microbial shelf-life without affecting the staling rate. The development of bread firmness during storage in 100% CO 2 for 49 days was found to be correlated to amylopectin retrogradation and to changes in the freezable water fraction of the breads in a non-linear manner, suggesting that bread firmness is influenced by both the crystallisation behaviour of starch and by changes in hydration.
Simulation of wheat (Triticum aestivum L.) yield using WOFOST model under different management levels

A field experiment was conducted at Agrometeorology Research Farm, Narendra Deva University of Agriculture & Technology, Narendra Nagar (Kumarganj), Faizabad (U.P.) during Rabi season 2012 and 2013 to study the “Simulation of wheat (Triticum aestivum L.) Yield using WOFOST model under different management levels”. The experiment consisted of 12 treatment combinations in tested Split plot design with three replications. Experiment consisted of three irrigations at different stage i.e. First Irrigations (CRI+ Tillering+ Ear Head Emergence +Milking, Second irrigation (CRI+ Ear Head Emergence + Milking) and Third irrigation (CRI+ Milking) and two date of sowing i.e. first is normal sowing (15 November) and second is delayed sowing (15 December) and two fertilizer doses higher dose (150:75:75 NPK kg ha-1) and optimum dose (120:60:60 NPK kg ha-1). Sensitivity of WOFOST model simulated grain yield to incremental units of maximum air temperature showed a gradual decrease in yield while, the down scaled maximum temperature increased the yield. The wheat yield increased due to decreased temperature ranged 5.7 to 25.4. While the reduction of yield due to increase of temperature from -8.8 to 26.3. Every 10C decrease in the minimum temperature increased the grain yield of wheat was 5.6, 12.1, 19.4, 23.9 and 26.8 respectively while increase in temperature from 10C to 50C wheat yield decrease from -11.0 to 37.9 percent.
Buildup of ultrathin multilayer films by a self‐assembly process, 1 consecutive adsorption of anionic and cationic bipolar amphiphiles on charged surfaces

An anionic and a cationic bipolar amphiphile containing rigid biphenyl cores were synthesized. The compounds were dissolved in a mixture of dimethylsulfoxide (DMSO) and water and pure water, respectively. When a solid substrate with a positively charged planar surface is immersed in the solution containing the negatively charged bipolar amphiphile, a monolayer of the amphiphile is adsorbed and due to its bipolar structure the surface charge is reversed. After rinsing in pure water the substrate is immersed in the solution containing the positively charged bipolar amphiphile. Again a monolayer is adsorbed but now the original surface charge is restored. By repeating both steps in a cyclic fashion alternating multilayer assemblies of both compounds are obtained. It is demonstrated that multilayer films, composed of at least 35 consecutively alternating layers, which corresponds to a total film thickness of 170 nm can be assembled.
Atomistic Simulation of the Dissociative Adsorption of Water on Calcite Surfaces

Atomistic simulation methods have been used to model the interaction of water with the {1014} calcite surface and the energetics for the removal of carbonate groups in the presence of water. Electronic structure calculations show that associative adsorption of water is the energetically favored mode of adsorption on the {1014} surface, that water is strongly bound to the surface, and that the atom-based simulations reproduce the energetics of adsorption. The use of atom-based molecular dynamics techniques on the calcite−water interface found that water loses its hydrogen-bond network when adsorbing on the surface and that it causes an oscillation of water density in the vicinity of the surface. Finally, we considered a possible reaction of the surface with water that would account for the presence of OH groups as observed experimentally on surfaces and would also constitute an initial step in the dissolution process. Our calculations suggest that carbonate groups at some step edges and low-index surface.
Equation of state and structure of prehnite to 9.8 GPa

The equation of state and high-pressure behaviour of a natural sample of prehnite from Kuruman, South Africa, Ca2.07(Al0.98,Mn0.02)(AlSi3.09O10)(OH)2, have been investigated using single crystal X-ray diffraction up to 9.75(3) GPa. A second-order Birch–Murnaghan equation-of-state fit to the isothermal P - V data below 8.7 GPa yields values of K 0T = 109.29(18) GPa and K ′ = 4. A third-order Birch-Murnaghan equation fit to the P - V data results in K ′ values equal to four, within an estimated standard deviation. The compressibility of a, b , and c unit-cell parameters is non-linear and strongly anisotropic, with room-pressure moduli of K a 0 = 83.5(7) GPa, K b 0 = 113(1) GPa, and K c 0 = 146(3) GPa and K ′ a 0 =4.5(3), K ′ b 0 = 1.3(3), and K ′ c 0 = 8.8(8). Intensity data were collected over the entire pressure range. Bond lengths and angles, refined in the average space group Pncm , suggest that the structure compresses uniformly. Above 8.7 GPa there is an additional softening of the volume and the b -axis, but the average structure is maintained across the transition.
SIMULTANEOUS EXTRACTION AND QUANTITATION OF OLEANOLIC ACID AND URSOLIC ACID FROM SCUTELLARIA BARBATA D. DON BY ULTRASOUND-ASSISTED EXTRACTION AND HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

A modified ultrasound-assisted extraction (MUAE) method and an HPLC technique were developed to identify and quantify simultaneously the amount of oleanolic acid (OA) and ursolic acid (UA) in Scutellaria barbata D. Don. The optimal conditions for MUAE were observed when the particle size was 0.2–0.5 mm, the duty cycle was 75%, the extraction temperature was 55°C, the ratio of solvent to raw material was 12.0:1 (mL:g), the ethanol concentration was 60%, and the extraction time was 25 min. Compared to the traditional extraction method, MUAE reduced the extraction time, extraction temperature, and solvent consumption and achieved superior yields of OA and UA. Furthermore, the combined MUAE-HPLC method was successfully applied for the first time to investigate and compare the amounts of OA and UA in samples obtained from different geographical regions.
Potentiometric titrations of polymethacrylic acid

Potentiometric titrations of polymethacrylic acid were performed at different concentrations, different molecular weights, and in the presence of neutral salts, as well as in dioxane-water mixtures. It was shown that the pH of the solutions fulfills the relation, pH = pK — n log [(1 — α)/α]. pK and n are independent of the molecular weight and concentration if a suitable activity factor is introduced. The equation is applicable to free acid solutions as well as acid mixtures. Copolymers of the type, polyallyl acetate-maleic acid, show a more complicated curve. The curve is of the “polydibasic” type. Each branch of it fits equation (2) well. The formula is analyzed and is proposed to be the result of the action of the Maxwell-Partington statistical factor, as well as of the decrease in entropy accompanying the stretch of the randomly kinked molecule. This stretch is caused by the repulsive forces between the ionized carboxyl groups. The distribution curves of the various degrees of ionization present, for any pH, are given. The activity correction implies small units of the size of one or two carboxyl groups. The behavior in salt solutions is dependent not only on the activity correction, but also on the salting-out factor. This factor is high in polyvalent salts. The titration curves in dioxane-water mixtures are satisfactorily accounted for by the change in the activity factor with the dielectric constant.
NMR spectral assignment of substituted salicylaldoximes by inverse pulse techniques with z‐gradient selection: correlation of NMR parameters with substituent constants

1H and 13C and also 1H,13C HMQC and 1H,X HMBC (X=13C and 15N) correlation maps with z‐gradient selection of seven salicylaldoximes were recorded and assigned and their parameters are discussed. The chemical shifts of H2, NOH, C7 and especially those of 15NOH correlate well with the Hammett and/or Brown–Okamoto substituent constants. Also the coupling constants 1J(C3,H3) and 1J(C7,H7) are linearly dependent on σ+. High correlation coefficients show the presence of the 2‐OH group to force the molecules of salicylaldoximes to be planar or almost planar as a result of the intramolecular hydrogen bonding between its hydrogen and oximine nitrogen atom. © 1997 John Wiley & Sons, Ltd.
Estimation of total erosion in cultivated Black soils in northeast China from vertical profiles of soil organic carbon

It is difficult to estimate soil thickness eroded from annual erosion rates in cultivated Black soils in northeast China because of the uncertainty of the time when the soil was first cultivated for agricultural crops. Assuming soil organic carbon (SOC) profile curves for cultivated sites are the same as virgin sites before cultivation, it may be possible to estimate the total thickness of surface soils lost by erosion by vertical movement of plotted SOC profiles until those for the virgin and cultivated soils are superimposed. We collected pairs of soil samples (0–1 m) with one sample in each pair from a virgin site and the other from a nearby cultivated site in Heilongjiang province, northeast China. In undulating areas where soil erosion was moderate, the shapes of SOC distribution curves below 40 cm depth were nearly identical for both cultivated and virgin soils, but were offset vertically. This offset was attributed to the loss of surface soil by erosion in the cultivated land. By moving the distribution curve of SOC in cultivated soil downwards by 12.7 cm, we found nearly coincident curves below 45 cm for the virgin and cultivated soils. This thickness (12.7 cm) was believed to be the depth of soils that had been eroded since the onset of cultivation in Black soils in northeast China. We concluded that the amount of surface soil lost by erosion could be estimated from comparison of the vertical distribution of SOC in cultivated and virgin soils.
The quantitative analysis of electrostatic potential and study of chemical bonding by electron diffraction structure analysis

Abstract The development of the electron diffractometry methods jointly the analytical methods of electrostatic potential (ESP) reconstruction and its topological analysis allowd one to proceed to the quality new level of electron diffraction structure analysis (EDSA): investigation inner crystalline electrostatic field, which knowledge permitts to study the relation of the atomic structure with physical properties of crystals. The review of the last achivements in this direction, obtained in the Institute of Crystallography of Russian Academy of Sciences, in which EDSA method was discovered, is done. The possibility of the EDSA method to solve precise problems of quantitative analysis of the electrostatic potential is shown on the examples of investigations of the ESP distributions and chemical bonding in crystals with NaCl-type structure and covalent crystal Ge. It is also shown that quantitative data on the potential distribution considerably enlarge conceptions on the nature of interatomic and inetrmolecular interactions in crystals.
ORGANIC MATTER CHARACTERISTICS OF UNDISTURBED AND CULTIVATED CHERNOZEMIC AND SOLONETZIC A HORIZONS

Under a wheat-fallow system of farming practised on Brown, Dark Brown, and Black Chernozemic soils, on a Black Solodized Solonetz, and on Brown and Black Solods, organic C decreased by as much as 60%; the humic acid/fulvic acid ratio decreased little for the semiarid soils but up to 38% for the Black soils; ethanol/benzene-extractable organic matter increased by as much as 330%; chelating resin-extractable C increased by 27–115%; and total acidity of the extracted humic substances increased up to 36%. The ash contents of the humic substances from the Ah horizons were all less than 12%, whereas those of the Ap horizons varied between 20 and 28%. Apparent differences between the infrared spectra of the resin-extractable humic substances of the Ah and Ap horizons existed particularly near 2920 and 1550 cm−1 suggesting less aliphatic C-H and amide bonds. Anthropogenic pressures have wrought, therefore, distinct measurable qualitative changes, i.e., the general trend with cultivation was towards humic material.
Antagonistic Competitive Equilibrium Modeling for the Adsorption of Ternary Metal Ion Mixtures from Aqueous Solution onto Bagasse Fly Ash

The present study reports the simultaneous adsorption of cadmium (Cd(II)), nickel (Ni(II)), and zinc (Zn(II)) ions from aqueous solution onto bagasse fly ash (BFA). BFA is a waste material collected from the particulate collection equipment attached to the flue-gas line of bagasse fired boilers in sugar mills. The equilibrium adsorption data were obtained with a BFA dosage of 10 g/dm3 at varying initial concentrations (C0 = 10−100 mg/dm3), 5 h contact time, 30 °C temperature, and initial pH 6. The single metal ion equilibrium adsorption data were fitted to the noncompetitive Langmuir, Freundlich and Redlich−Peterson (R−P) models. The R−P and Freundlich models represent the equilibrium data better than the Langmuir model over 10 ≤ C0 ≤ 100 mg/dm3. The adsorption capacity of Zn(II) is found to be higher than that of Ni(II) or Cd(II) for the ternary metal solutions, and is in agreement with the single-component adsorption data. The equilibrium metal removal decreases with an increase in the concentration of .
A novel approach based on differential scanning calorimetry applied to the study of tricalcium silicate hydration kinetics

Complex reactions taking place between Ca3SiO5 and water can be considered the main cause for setting and hardening of Portland cement pastes. The “in situ” kinetics of the “hydration” process has been recently studied, as a function of time, using neutron scattering to obtain the trend of the fraction of free water (free water index, FWI), i.e., the fraction of unreacted water. In this study we developed a novel and simple approach on the basis of differential scanning calorimetry to follow the hydration kinetics of Ca3SiO5 in real time from the decrease of the free water index. FWI has been obtained by measuring the fraction of water in the Ca3SiO5 paste that can solidify and melt. We report the trend of FWI as a function of Ca3SiO5 paste hydration and the results are compared to recent quasi-elastic neutron scattering experiments. The results account well for the hydration process described by two kinetic stages, the first according to an Avrami−Erofeev nucleation and growth law, and the second one to .
Simultaneous determination of specimen temperature and specimen displacement in high-temperature X-Ray diffractometry applying Bragg-Brentano geometry

Temperature uncertainty and unknown specimen displacement are the most severe errors in high-temperature X-ray diffractometry, in particular when using a strip heater mounted on a Bragg–Brentano goniometer. A method is presented that enables the simultaneous determination of the specimen displacement and the temperature of the sample. The method splits the determination of the aberrations into two steps: at room temperature and at elevated temperature. It is based on the use of a reference material as an internal standard. An experimental example applying the method to a specific material is given, and shows that the method provides correct data.