Miracle-dz/UniFAR-FTUs huggingface dataset:
The role of carbon surface diffusion on the growth of epitaxial graphene on SiC

We have observed the formation of graphene on SiC by Si sublimation in an Ar atmosphere using low-energy electron microscopy, scanning tunneling microcopy, and atomic force microscopy. This work reveals unanticipated growth mechanisms, which depend strongly on the initial surface morphology. Carbon diffusion governs the spatial relationship between SiC decomposition and graphene growth. Isolated bilayer SiC steps generate narrow ribbons of graphene by a distinctive cooperative process, whereas triple bilayer steps allow large graphene sheets to grow by step flow. We demonstrate how graphene quality can be improved by controlling the initial surface morphology to avoid the instabilities inherent in diffusion-limited growth.
Planar and Nonplanar Conformations of (meso-Tetraphenylporphinato)nickel(II) in Solution As Inferred from Solution and Solid-State Raman Spectroscopy

The coexistence in solution of at least two conformers of (meso-tetraphenylporphinato)nickel(II) [Ni(TPP)] is inferred from solution and single-crystal resonance Raman spectra obtained at different temperatures (170 − 297 K) and excitation wavelengths (413.1 and 457.9 nm). The shapes of the structure-sensitive Raman lines ν8 and ν2 are clearly asymmetric and change with temperature. These broad lines can be decomposed into at least two sublines, a low-frequency (LF) and a high-frequency (HF) component. In contrast, the corresponding single-crystal Raman lines of the nonplanar structure of Ni(TPP) in the crystal are narrow and symmetric. For the line ν2, the broad LF subline results from nonplanar conformers and the narrow HF subline arises from a more planar conformer. This assignment is consistent with the observation that the LF subline of ν2 is more enhanced upon changing the excitation wavelength from 413.1 to 457.9 nm. The selective resonance enhancement is caused by the red shifts of the UV−visible .
Hydrolytic liquefaction of hydrolysis lignin for the preparation of bio-based rigid polyurethane foam

Hydrolysis lignin (HL) was liquefied to a low average molecular weight (Mw) intermediate by employing a 50/50 (v/v) water–ethanol mixture. The effects of process parameters including the reaction temperature, the reaction time and the HL concentration were investigated and the liquefied hydrolysis lignin (LHL) products obtained were characterized by GPC, FTIR and 1H NMR. The best operating conditions appeared to be at 250 °C, 1 h with 20% (w/v) HL concentration, leading to ∼70 wt% yield of LHL (Mw ∼ 1000 g mol−1 and OHTotal ∼ 442 mg KOH g−1). The solid form LHL was derivatized into liquid polyols via oxypropylation with 50–70 wt% bio-content, which was subsequently utilized for the preparation of bio-based rigid polyurethane (BRPU) foams. All the foams were characterized in terms of their physical, mechanical and thermal properties & morphology. BRPU foams exhibit superior compression modulus and strengths to a reference foam prepared from commercial sucrose polyols provided by Huntsman Co. At a fixed formulation, i.e., a fixed percentage of physical blowing agent, BRPU foams showed the following sequence in terms of their compression modulus: sucrose polyol reference foam (2695.0 kPa) < LHL50PO50 (9202.0 kPa) < LHL60PO40 (19 847.0 kPa) < LHL70PO30 (21 288.0 kPa). All BRPU foams were thermally stable up to approximately 200 °C and thermal conductivity was low (0.030 ± 0.001 W m−1 K−1), making them suitable candidates for insulation material.
The defect structure of hyper-stoichiometric uranium dioxide

Earlier neutron-diffraction measurements [Willis (1964), Proc. Br. Ceram. Soc. 1, 9-19] on a single crystal of UO2.12 at 800°C showed that interstitial oxygen atoms enter the UO2 lattice at two kinds of site, which are displaced by about 1 A along the (110) and (111) directions from the cubic-coordinated interstitial sites. It was also shown that the solution of oxygen is accompanied by the formation of vacancies in the normal oxygen sites, but that the uranium sublattice remains undisturbed. A new analysis of the same data has been carried out, which introduces constraints between some of the parameters and allows a more satisfactory treatment of the anharmonic motion of the oxygen atoms. The new analysis leads to a much more precise determination of the occupation numbers of the (110) and (111) oxygen atoms and of the normal oxygen vacancies. The simplest model to account for these new results is the so-called 2:2:2 configuration of oxygen defects.
Mechanisms and Kinetics of Thermal Degradation of Poly(ε-caprolactone)

Thermogravimetric analysis (TGA) simultaneously coupled with mass spectrometry (MS) and Fourier transform infrared spectrometry (FTIR) was developed as an original technique to study the thermal modification/degradation of poly(e-caprolactone) (PCL) through in depth analysis of the evolved gas. Perfectly well-defined PCL samples with controlled end groups, predictable molecular weight, and narrow molecular weight distribution were synthesized by living “coordination−insertion” ring-opening polymerization of e-caprolactone initiated by aluminum triisopropoxide. TGA analyses carried out on purified PCL samples, deprived from any residual catalyst or monomer, highlighted a two-step thermal degradation. Evolved gas analysis by both MS and FTIR showed that the first process implies a statistical rupture of the polyester chains via ester pyrolysis reaction. The produced gases were identified as H2O, CO2, and 5-hexenoic acid. The second step leads to the formation of e-caprolactone (cyclic monomer) as result of .
Performance of CCSDT for first row AB/AB− diatomics: Dissociation energies and electron affinities

CCSDT/aug-cc-pVXZ (X=D,T,Q) calculations were performed on the C2, C2−, CN, CN−, O2, and O2− first row diatomic molecules. The inclusion of diffuse functions improves the dissociation energies of the anionic systems by 2.0–3.4 kcal/mol, which is relevant bearing in mind the goal of achieving chemical accuracy. The contribution of the diffuse functions in the case of neutral O2 (0.6 kcal/mol) is by no means negligible in this context. A serious discrepancy between the theoretical prediction and the experimental values available for the dissociation energy of C2− was found. Since the theoretical deficiences commonly ascribed to the CCSDT method (single-reference and spin contamination when using UHF zeroth-order wave functions) cannot be invoked in this case, further experimental work is required to throw some light on the origin of such a discrepancy. The performance of CCSDT for adiabatic electron affinities is excellent in the case of O2/O2− and CN/CN−. For C2/C2−, the observed discrepancies can be expla.
Selective Recognition of Endosulfan Pesticide in Environmental Matrix with Molecularly Imprinted Polymer Membrane

The excessive and uncontrolled uses of Endosulfan pesticide in crops have raised an alarm for its toxicity not only in crops but also in drinking water. So, it has become imperative to detect and separate the hazardous pesticide Endosulfan from contaminated water. In present studies, molecularly imprinted membrane has been fabricated for the specific recognition of Endosulfan pesticide, which is widely being used in controlling insects. The composite membranes have been prepared by using Methacrylic acid (MAA) as functional monomer and Ethylene Glycol Di Methyl Acrylate (EGDMA) as cross linker. MAA was chosen as a functional monomer, as it is capable of strong electrostatic interactions with Endosulfan. The molecular imprinting of Endosulfan on membrane matrix was confirmed by the Solid Phase Extraction (SPE), UV-Visible spectrophotometer, Fourier Transform Infra-Red (FTIR) Spectrophotometry and Scanning Electron Microscopy (SEM). This was followed by sensing of the herbicide by SPE measurements.
Key events and critical incidents influencing transport mode switching behavior - an exploratory study

This paper reports the findings of a qualitative research project about the impact of key events and critical incidents on transport mode choice switching behavior among 115 subjects. The results indicate that some key events and critical incidents have a dramatic impact on transport mode switching behavior. While events in one's personal life may lead people to switch their transport mode, attributes of the modes and the transportation system at large seem less influential. Implications for service management of public transportation firms are discussed.
THE EQUILIBRIUM OF A THIN COMPRESSIBLE MEMBRANE

An investigation has been made of the equilibrium of a thin incompressible elastic membrane lying between two rigid bodies, one fixed and the other mobile. The present paper concerns the corresponding problem for a compressible membrane.Membranes are divided mathematically into four classes according as their compressibility is (i) finite, (ii) small, (iii) very small, (iv) so small that the membrane may be considered as incompressible. The movable boundary is assigned a rigid body displacement. By the introduction of approximation based on the thinness of the membrane a determination of the resulting stress, strain and displacement is made for each of the above four classes of membranes.
Aryl hydrocarbon receptor‐mediated toxic potency of dissolved lipophilic organic contaminants collected from Lincoln Creek, Milwaukee, Wisconsin, USA, to PLHC‐1 (Poeciliopsis lucida) fish hepatoma cells

Lincoln Creek is a severely degraded urban stream located in Milwaukee County, Wisconsin, USA. As part of a comprehensive study on effects of urban storm water runoff on the stream biota, an in vitro bioassay with PLHC‐1 (Poeciliopsis lucida) fish hepatoma cells was used to assess potential toxic potency of aryl hydrocarbon receptor (AhR)‐active compounds, collected by semipermeable membrane devices (SPMDs) exposed to Lincoln Creek water. Dialysates from SPMDs exposed to Lincoln Creek water caused marked cytochrome P4501A induction in PLHC‐1. Toxic potency of dialysates, expressed as bioassay‐derived 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin equivalents (TCDD‐EQ) ranged from 1,300 to 6,600 pg TCDD‐EQ/g SPMD for 14‐d exposures. Dialysates from SPMDs exposed to stream water at base flow had potencies consistently lower than those exposed to storm‐flow (high‐flow) events that occurred during the same 14‐d period. Polychlorinated biphenyls were not detectable in the dialysates. Gas chromatography‐mass spectrometry analysis identified polycyclic aromatic hydrocarbons (PAHs) as major contaminants in the dialysates. A log‐log correlation of total PAHs and TCDD‐EQ yielded an r2 of 0.802. Empirical evidence suggests that AhR‐active PAHs can account for about 20 to 50% of the potency observed.
A theoretical and experimental investigation of temperature variation behind attenuating shock waves

Temperatures in the range 2000 to 2700 °K have been measured behind shock waves in nitrogen and oxygen, by means of the sodium-line-reversal technique developed by Clouston et al. (1958, 1959). Early tests at low initial pressures in nitrogen, in which a significant time was required for molecular vibrational equilibrium behind the shock front, showed discrepancies of the order of 200 degK between the equilibrium temperatures then obtained and those inferred from the measured speed of the shock. These are explained as being due to attenuation, as a result of which the particles at the head of the relaxation zone are raised to lower temperatures than those at the rear, which passed through the shock earlier in its flight. A simple expression is derived from linearized shock-tube theory relating the change in temperature between the shock and a point behind it to the corresponding change in pressure, and to the previous history of the shock. Systematic tests have now been carried out in which these variables were measured separately over a range of initial pressures in both gases. The equation for temperature rise balanced closely in all cases. The measured temperature at the shock front in oxygen was, however, consistently lower than that corresponding to the observed shock speed, for reasons that are not at present clear. It is pointed out that the effect described is in a sense the one-dimensional unsteady analogue of the temperature change through the entropy layer in steady hypersonic flow.
Volatilização de amônia, lixiviação de nitrogênio e produtividade de milho em resposta à aplicação de misturas de uréia com sulfato de amônio ou com gesso agrícola

The side-dressing fertilization of annual crops should consider S, beside N and K, in order to add protein value to the crop production. This work was carried out in the crop year 2004/2005, in the Farm Floresta do Lobo - Pinusplan, located at the km 93 of BR 050 highway, in the county of Uberlândia (MG). The experiment was installed in acric Red Latossol typical Cerrado phase clayed (720 g kg-1), with the following objectives: to measure the losses by volatilization of NH3-N from some of the used mixtures at side-dressing in corn crop; to evaluate the distribution down to 60 cm deep, of mineral-N (NH4+-N and NO3--N) and SO42--S after 37 and 51 days of the side-dressing; and evaluate the effect on the corn yield, of granulated mixtures with different particles sizes and N:S ratios, in relation to urea (U) and ammonium sulphate (AS) exclusives. Eleven treatments in randomized blocs design of N:S:K fertilizers were used in side-dressing, in the corn stage of 5-6 leaves, in the rate of 90 kg ha-1 of N, as exclusive U or AS, or mixtures of U+AS granulated (U+ASgr) and U+AS with different size particles (U+ASfa) and U+Gypsum granulated (U+Gypsumgr) and U+Gypsum powder (U+Gypsumpowder). The more significant gas losses of NH3-N were in decrecent order: U exclusive 76.8 % followed by U+ASgr 37,9 %; U+Gypsumgr 27.7 % and ASfa exclusive (7.8 %). The concentration of ammonium-N and nitrate-N after 37 days of the fertilizer application was similar to the control (without N), demonstrating that the N supplied by the fertilizers were assimilated by the crop, nitrified, leached and, or, adsorbed more deeply. The sulphate-S, at the superficial layer presented the lower concentration in all treatments, reducing its concentration in the layer of 0 to 10 cm, and the 37 to 51 days of the fertilizer applied. After 51 days of the mixtures application, the concentration of total mineral-N was more expressive in the layers of 20 and 40 cm deep, demonstrating the leaching of N from the superficial layers. In the treatments with exclusive application of U and AS this tendency was weaker. In general it had greater ratio of the nitrate-N that of ammonium-N in the total mineral-N in the analyzed layers. In relation to sulphate-S, was expressive increasing the concentration in deeper layers. In stage of flowering, the analysis of nutrients in the leaf opposite the spike showed no significant difference in the ratio N:S leaf, and, this relationship in the shoots of the plant. The highest yields were reached by the treatments of U+ASfa and U+Gypsumgr: 10.285 and 10.241 kg ha-1 of grains, respectively. The treatments with higher yields were the ones with U+ASfa or AS+Gypsumgr with the N:S ratios between 2,75 to 4,00. These results allow to conclude that the application of sulphur as side-dressing is necessary and it can be done by mixing U with AS or U and Gypsumgr, although this later one have presented significant higher NH3 losses.
IN­VITRO ANTIOXIDANT AND ANTI­INFLAMMATORY ACTIVITY OF METHANOL EXTRACT OF OXALIS CORNICULATA LINN

Methanol extract of whole plant of Oxalis corniculata Linn (Family: Oxalidaceae) was assessed for its antioxidant and anti‐inflammatory activity by in­vitro methods. Antioxidant activity was studied using 1, 1‐Diphenyl‐2‐Picrylhydrazyl (DPPH) and nitric oxide radical scavenging activity. Inhibition of lipid peroxidation was studied by thiobarbituric acid reactive substances (TBARS) method on isolated rat liver tissues. Quantitative analysis of antioxidative components like total amount of phenolics, flavonoids and flavonols were estimated using spectrophotometric method. In­vitro anti‐inflammatory activity was evaluated using albumin denaturation assay, membrane stabilization assay and proteinase inhibitory activity at different concentrations. Aspirin was used as a sta ndard drug for the study of anti‐ inflammatory activity. Linear regression analysis was used to calculate IC50 value. Results showed that, the extract exhibited significant DPPH and nitric oxide radical scavenging activity with IC50 v alue of 302.93±4.17 and 73.07±8. 28µg/ml respectively. Lipid peroxidation induced by the Fe2+, was inhibited by the extract with IC50 value 58.71±2. 55µg/ml. Total phenol content was estimated as 25.62±0.10mg of gallic acid equivalents of dry extract. Total flavonoids and flavonols were found to be 150.88±12.61 and 150.16±2.16 mg of rutin equivalents per gram of dry extract respectively. Extract also showed in­vitro anti‐inflammatory activity by inhibiting the heat induced albumin denaturation and Red Blood Cells membrane stabilization with the IC50 values of 288.04±2.78 and 467.14±9. 56µg/ml respectively. Proteinase activity was also significantly inhibited by the extract (IC50=435.28±5.82µg/ml). From the results, it is concluded that flavonoids and related polyphenols present in the O. corniculata extract may be responsible for the activity.
Portable Continuous Ultrasound-Assisted Oxidative Desulfurization Unit for Marine Gas Oil

A tailor-made module reactor, the sonoreactor, was successfully assembled to demonstrate the oxidative desulfurization of petroleum oil. This is a unique unit constructed specifically for assisting petroleum industries. Therefore, on the basis of the concept of module design, the portable unit of continuous flow system, which consists of a sonoreactor, a RF amplifier, a function generator, a pretreatment tank, and a pipeline system, was operated at ambient temperature and pressure for a given time. For the best quality or quantity purposes and performance, multiple sonoreactors can be scaled up to connect in series or in parallel, respectively. This portable unit of continuous flow system has demonstrated the feasibility of large-scale operation even in a relatively small installation area with low capital investment and maintenance cost. It also ensures the safety considerations by operating under ambient temperature and pressure and permits a multistage process for the best quality or quantity purposes .
Feasibility of Ionic Liquids as Alternative Separation Media for Industrial Solvent Extraction Processes

Extraction of rare earth metals into ionic liquids (ILs) from aqueous solutions was investigated using octyl(phenyl)-N,N-diisobutylcarbamoylmethyl phosphine oxide (CMPO) as an extractant. Use of ILs greatly enhanced the extraction efficiency and selectivity of CMPO for metal ions compared to when n-dodecane was used as the extracting solvent. The extraction mechanism has been studied by slope analysis and extraction tests, and these confirmed that the metal extraction proceeds via a cation-exchange mechanism. Furthermore, stripping of metals from ILs into an aqueous phase by complexing agents and recycling of the extracting ILs phase was successfully accomplished.
THE DETERMINATION OF IONIC DIFFUSION COEFFICIENTS IN FIELD SOILS. I. DIFFUSION COEFFICIENTS IN SIEVED SOILS IN RELATION TO WATER CONTENT AND BULK DENSITY

Summary A method for measuring diffusion coefficients in large cores of structured field soils has been developed and tested, in the first instance using sieved soil. Bromide-chloride and bromide-nitrate counter diffusion coefficients have been determined using ion exchange membranes as sinks for the diffusing ions. The effects of membrane selectivity, soil surface preparation, solution concentration, water content and bulk density have been investigated. The organic colloid content appears to have a considerable influence on the impedance factor-water content relationship of a soil. Increasing the bulk density at constant volumetric water content linearly reduced the impedance factor by up to 30 per cent. The relationship between impedance factor and bulk density is discussed.
RELAXATION OF ASPHALTENES AT THE TOLUENE/WATER INTERFACE: DIFFUSION EXCHANGE AND SURFACE REARRANGEMENT

Upon adsorption at the oil/water interface, asphaltenes slowly form a glassy interphase. This robust, asphaltene-rich interphase is likely the reason for prolonged stability of crude oil/water emulsions and for the propensity of asphaltenic crude oils to alter the wettability of reservoirs. Here we adopt interfacial dilatation rheology using the oscillating pendant drop with axisymmetric drop shape analysis (ADSA) to investigate the relaxation mechanisms of asphaltenes adsorbed at the toluene/water interface. We compare classical viscoelastic models with the measured rheologic data and find that the frequency response of the dilatational moduli fits a combination of diffusion-exchange and surface-rearrangement mechanisms. The combined relaxation model is verified by solvent washing the asphaltenes from the interface and measuring the dilatational response of the resulting irreversibly adsorbed species. After washout, the oil-phase diffusion component of the frequency response disappears, and the relaxation time of the adsorbed film increases by an order of magnitude. Since the studied asphaltenes prove insoluble in the synthetic aqueous brine (pH = 8.0), this result suggests that reversibly exchanging species in the oil phase weakens an interconnected asphaltene-gel/glass phase at the interface. Our experiments show, for the first time, that most of the surface-active asphaltenic molecules are irreversibly adsorbed from the oil phase.
BIODEGRADATION OF PAHS IN LONG-TERM CONTAMINATED SOIL CULTIVATED WITH EUROPEAN WHITE BIRCH (BETULA PENDULA) AND RED MULBERRY (MORUS RUBRA) TREE

The ability of birch (Betula pendula) and mulberry (Morus rubra), cultivated either separately or together with perennial ryegrass (Lolium perenne), to enhance the biodegradation of 15 selected polycyclic aromatic hydrocarbons (PAHs) in long-term contaminated soil was studied in a greenhouse experiment. The microecosystems (MESs) were cultivated for either 12 or 18 months at a natural photoperiod. The fact that the soil chosen for cultivation had been contaminated for over 50 years was expected to be the main factor limiting biodegradation. Extracts of both planted and unplanted soil were analyzed using HPLC. After 1 year of cultivation, the overall content of the investigated compounds had declined to 50%. The concentrations of fluoranthene and pyrene, the PAHs originally present in the soil in the highest concentrations (103.5 and 83.3 mg/kg, respectively), had decreased to 28.0 and 18.0 mg/kg, respectively. In addition, other compounds were successfully degraded, including even benzo[a]pyrene. Benzo[ghi]perylene and indeno[1,2,3-cd]pyrene were the only PAHs remaining and were almost entirely undegraded. Because few significant differences were found between the various types of MESs studied, degradation can primarily be attributed to the presence of degrading microorganisms in the soil.
Electrochemical corrosion study of high moment thin film head materials

An electrochemical corrosion study of high moment, magnetically soft FeXN (X=metal) thin film head materials is presented. Potentiodynamic anodic polarization in aqueous 0.5M NaCl and 0.25M Na/sub 2/SO/sub 4/ solutions is studied for qualitative and quantitative measures of corrosion characteristics. The effect of annealing, composition, and a comparison with Permalloy and Fe thin films are also presented. A drastic improvement in corrosion characteristics result in the samples made with N/sub 2/ flow rate >10 sccm. >