Miracle-dz/UniFAR-FTUs huggingface dataset:
Surface reaction and pore diffusion in flow-tube reactors

The interaction of gas diffusion with surface reaction in porous solids is discussed and applied specifically to heterogeneous rate measurements in flow-tube reactors. External diffusion to the outer surface of a reactive solid, internal diffusion within the pores, surface reaction, and laminar flow are considered. A procedure is developed to correct observed surface rate constants for the interaction of these processes. Measured surface areas and bulk densities are used to construct a semiempirical model for porous diffusion in vapor-formed HNO3-H2O ices which are used to simulate polar stratospheric cloud surfaces. The model is tested experimentally by varying the thickness of these ices from about 15 to 120 microns. The results are consistent with the model predictions and show that the HNO3-H2O ices used are highly porous, and the internal surface must be considered in calculating kinetic parameters from observed loss rates. The best fit of the data yields a tortuosity factor of 3.3 +/-1.1 for the ice substrates.
Investigations of closely coupled pilot and main injections as a means to reduce combustion noise in a small-bore direct injection Diesel engine

Various pilot–main injection strategies are investigated in a single-cylinder optical Diesel engine. It is observed that as the dwell between a single pilot and the main injection is decreased toward zero, combustion noise passes through a minimum, and a reduction of 3 dB is possible. The injection schedules employed in the engine are analyzed with a hydraulic injection analyzer to provide rate shapes for each of the dwells tested. Two distinct injection events are observed even at the shortest dwell tested, and various rate shaping effects are observed with the main injection event as the dwell is adjusted. High-speed elastic scattering imaging of liquid fuel is performed in the engine to examine initial spray penetration rates. These compare favorably to the measured rates of injection, thus providing evidence that rate shaping of the initial phase of the main injection occurs in the engine and that this rate shaping is consistent with the injection rate data. However, experimental evidence suggests that these changes are not responsible for the observed trend in combustion noise as dwell changes. The combination of thermodynamic data and rate of injection data supports the theory that the main injection interacts with the pilot mixture field and influences its heat release process, thus playing a role in decreasing combustion noise. The relative phasing of the pilot and main heat release may play a significant role in reducing combustion noise; further studies will focus on combustion phasing effects.
Solid-state nuclear magnetic resonance spectra of dipolar-coupled multi-spin systems under fast magic angle spinning

A general treatment of nuclear magnetic resonance (NMR) spectra under magic-angle spinning (MAS) conditions is provided that is applicable both to homogeneously and inhomogeneously broadened lines. It is based on a combination of Floquet theory and perturbation theory, and allows the factorization of the spin system response into three factors that describe different aspects of the resulting MAS spectrum. The first factor directly reflects the Floquet theorem and describes the appearance of sidebands. The other two terms give the integral intensities of the resulting sidebands and their line shapes and depend on the specific features of the considered interaction. The analytical form of these two factors is derived for multi-spin dipolar interactions under fast MAS. The leading term in the expansion of the integral intensities involves products of only two spin operators whereas the linewidths, which are found to be different for the different sideband orders, are determined predominantly by three-spin te.
Amino Acid Profiles and Cytotoxicity of Mirabilis expansa (Ruiz and Pav.) Standl.; Baseline Data for A Rare Indigenous Andean Crop

Rare, indigenous, Andean Mirabilis expansa (Ruiz and Pav.) Standl. (Nyctaginaceae), has promise as a new, green, climate change resistant crop for arid areas. Leaves and stems were used as fodder, roots and rhizomes for human food. Two crop varieties of M. expansa were grown in lysimeter sand plots in southern Illinois. Herbage and root profiles were compared to amino acid profiles for other crops, eggs and milk. Quinoa, wheat, soybeans, and skim milk had greater percentages than M. expansa of all individual amino acids reported. However, M. expansa samples have all essential amino acids, and matched or exceeded other sources examined for percentages of crude and total protein. Total protein per 100 g dry sample averaged 5.98 g in roots and 24.43 g in leaves. Cytotoxic, non-volatile micro molecules were not detected in methanol extracts of M. expansa assayed against HT-29 colon cancer cells. Processing should improve palatability and food safety for this crop.
Antimicrobial properties of natural dyes against Gram‐negative bacteria

There is increasing interest in adding value to textiles by the use of natural products. Many of the plants from which natural dyes are obtained are, for example, also known to have medicinal properties. In the current study, the antimicrobial properties of eleven natural dyes against three types of Gram-negative bacteria were studied experimentally. Seven of the dyes showed activity against one or more of the bacteria. The minimum inhibitory concentration for three selected dyes was determined. The results demonstrate that certain dyes are able to reduce microbial growth almost completely in the case of Escherichia coli and Proteus vulgaris. Selected dyes would therefore be valuable for the dyeing of sheets and gowns for hospital use, and on articles which are less suitable for laundering such as mattresses and upholstery. The dyes examined exhibited good wash fastness and the antibacterial effect is therefore likely to be durable.
Kinetics of Cellulose Pyrolysis in Nitrogen and Steam

Abstract Kinetics of cellulose pyrolysis in nitrogen and steam at five different heating rates are presented. A single rate equation for each pyrolysis medium is discussed which provides a good engineering fit to the weight loss curves. The presence of steam in the pyrolysis medium was found to have no measurable affect on cellulose pyrolysis kinetics. The activation energy, pre-exponential factor and reaction order for nitrogen and 1 steam pyrolysis of cellulose are: 36.6 kcal/mol, 6.06 × 109sec-1, 0.46 and 34.2 kcal/mol, 1.67 / 109 sec-1, 0.51 respectively. Apparent differences in the data derived using steam rather than nitrogen as a pyrolysis medium are shown to be artifacts of heat transfer phenomenon within the TGA instrumentation used to measure rate of weight loss. Heat transfer effects observed here may explain the large discrepancies in previously reported studies of cellulose pyrolysis kinetics. Kinetic data given for steam pyrolysis are believed to be more accurate due to the more accurate mea.
Biochar application to temperate soils: Effects on soil fertility and crop growth under greenhouse conditions

Biochar (BC) application as a soil amendment has aroused much interest and was found to considerably improve soil nutrient status and crop yields on poor, tropical soils. However, information on the effect of BC on temperate soils is still insufficient, with effects expected to differ from tropical soils. We investigated the effects of BC on soil nutrient dynamics, crop yield, and quality in a greenhouse pot experiment. We compared three agricultural soils (Planosol, Cambisol, Chernozem), and BCs of three different feedstocks (wheat straw [WS], mixed woodchips [WC], vineyard pruning [VP]) slowly pyrolyzed at 525°C, of which the latter was also pyrolyzed at 400°C. The BCs were applied at two rates (1% and 3%, which would correspond to 30 and 90 t ha–1 in the field). Three crops, namely mustard (Sinapis alba L.), barley (Hordeum vulgare L.), and red clover (Trifolium pretense L.) were grown successively within one year. The investigated soil properties included pH, electrical conductivity (EC), cation-exchange capacity (CEC), calcium-acetate-lactate (CAL)–extractable P (PCAL) and K (KCAL), C, N, and nitrogen-supplying potential (NSP). The results show a pH increase in all soils. The CEC increased only on the Planosol. The C : N ratio increased at 3% application rate. Despite improving the soil nutrient status partly, yields of the first crop (mustard) and to a lesser extent of the second crop (barley) were significantly depressed through BC application (by up to 68%); the yield of clover as third crop was not affected. Only the BC from WS maintained yields in the range of the control and even increased barley yield by 6%. The initial yield reduction was accompanied by notable decreases (Cu, Fe, Mn, Zn) and increases (Mo) in micronutrient concentrations of plant tissues while nitrogen concentrations were hardly affected. The results of the pot experiment show that despite additional mineral fertilization, short-term growth inhibition may occur when applying BC without further treatment to temperate soils.
Simplified Modelling of the Complexation of Humic Substance for Equilibrium Calculations

For the prediction of chemical species distribution in systems containing humic substances (HS), a simplified complexation model was proposed in our previous study. In the model, the logarithm of the apparent complexation constant is described using the equation log Kc app = log Kc + ac log α bc log I − mc log [M] consisting of four HS specific parameters, log Kc , ac , bc , and mc , which are the minimized number of parameters to reproduce the complexation as a function of α (degree of dissociation of functional groups of HS), I (ionic strength of bulk solution), and [M] (free metal ion concentration). In this study, the applicability of this model was demonstrated by applying the equation to the complexation data of Ca(II) obtained by potentiometric titration in awide range of pcH (= −log [H+]), Ca(II) concentration, and ionic strength, as well as to the complexation data of Al(III), Ca(II), Cu(II), Pb(II), Am(III), Cd(II), Cm(III), Co(II), Dy(III), Eu(III), and U(VI) reported in the literature. The proposed equation fairly well reproduced a variety of complexation data with the minimum specific parameters, indicating the suitability of the proposed model for the purpose of equilibrium calculation of metal ion species in the system containing HS as a soluble ligand.
Cytological study of body fluids for malignancy

Introduction: The effusion fluid analysis plays an important role in neoplastic conditions. The present study was undertaken to highlight the frequency of malignant cells in various body fluid. Materials and Methods: This observational study was performed for the period of one and half year. A total of 250 various type of body fluid samples received during the study period in the Department of Pathology, Rajarajeshwari Medical College and Hospital, Bengaluru, Karnataka were studied. Results: Most of the fluid samples belonged to males (59.20%) and the male to female ratio was 1.45:1. The common age group of specimen received was 40 to 50 years (21.20%). Most of the malignant lesions that is 53.85% and most of the suspicious of malignancy that is 66.67% were belonged to peritoneal fluid. Conclusions: Pleural fluids were the most common type of fluid received for analysis. Most of the fluid samples belonged to males. The frequency of malignancy in the population studies was 5.20% with adenocarcinoma being the common malignant lesion.
Caracterização química e físico-hídrica de um Latossolo Vermelho após vinte anos de manejo e cultivo do solo

The management and tillage change the soil structure, which in turn interferes with a series of physic-hydraulic properties in the surface soil layer. This work had as objective to evaluate chemical and physical-hydraulic soil properties that have implications on soil aggregation, macroporosity, and the available soil water in Red Latosol (Oxisol), either cropped under no-tillage or disk plowed for 20 years. The control was a native Cerrado (savannah) vegetation. Because of the absence of soils tillage and reduced machinery traffic, the no-tilllage system led to a decrease in macropore volume at a soil depth of 0-5 cm. However, this change caused no restriction to cultivation since the largest soil water availability at this depth had been observed in this system in comparison to the other studied systems. Soil bulk densities in the area under no-till, in the studied depths, were smaller or equal to those of the area under disk plowing, possibly due to the higher organic carbon content in that system and the absence of soil revolvement. The observed mean geometric diameters of aggregates up to 10 cm depth, in descending order, were found in soils under native vegetation (Cerrado), no-till, and disk plow. No significant differences were found at greater depths. At the 20-30 cm depth, disk plowing was the system that affected the Red Latosol structure the most, as indicated by the largest value of soil bulk density, smaller macroporosity, and a larger downward displacement of the characteristic soil moisture curve in the tension range of 0 to 6 kPa and upwards for tensions between 6 and 100 kPa.
Electron Momentum Density of Hexagonal Magnesium Studied by Compton Scattering

Directional Compton profiles of single crystal of hcp magnesium have been measured with scattering vectors along the [10 10], [1120] and [0001] directions in reciprocal space (special directions ΓΜ, ΓΚ, ΓΑ) using high-energy (662 keV) gamma radiation from a 137Cs isotope source. The experimental data were compared with corresponding theoretical Korringa-Kohn-Rostoker (KKR) calculations. The directional difference profiles, both experimental (of medium resolution) and theoretical ones, show very small anisotropy of the electron momentum density in magnesium, 2-3 times lower than in zinc and cadmium single crystals, significantly lower than observed in cubic metals. This small directional effect is in good agreement with Compton 60-keV energy experiments and positron annihilation data presented by other authors.
Structure of a simple fluid near a wall. II. Comparison with Monte Carlo

Monte Carlo methods are used to calculate density profiles of a dense simple fluid, interacting through a pair potential containing a hard‐sphere core and truncated Lennard‐Jones attractive tail, near a hard repulsive wall. The results are compared with integral–equation calculations based on the wall‐particle Ornstein–Zernike equation, with closure approximations such as EXP. The integral equations fail to show several features of the Monte Carlo results, namely dependence on the distance at which the Lennard‐Jones attraction is truncated, and the accumulation of conjugate vapor phase near the wall, which tends to suppress oscillations in the profiles.
Ambipolar and nonambipolar cross-field diffusions

The two-dimensional (2D) steady state of plasma confined radially by an axial magnetic field is studied. An analytical solution of the 2D diffusion equation is found by a variable separation for constant transport coefficients, without the assumption that the flow is ambipolar. The analytical solution is employed for comparing ambipolar flow with the ‘short-circuit’ limit of a nonambipolar flow. The nonlinear one-dimensional (1D) cross-field diffusion problem is formulated, where the nonlinearity results from the dependence of the transport coefficients on the plasma and neutral densities. The different roles of collisions with plasma particles and with neutral particles are unfolded in the two types of flow, ambipolar and nonambipolar, in either flattening the density profile or making it more peaked. The effect of neutral depletion on the cross-field diffusion is explored.
Probing the Nature of the CoIII Ion in Cobalamins − Spectroscopic and Structural Investigations of the Reactions of Aquacobalamin (Vitamin B12a) with Ambident Nucleophiles

The rate of substitution of the H2O β-ligand in aquacobalamin (vitamin B12a) is surprisingly fast for CoIII. This may arise as a result of transfer of electron density to CoIII by the corrin, conferring on the metal atom a softer and more labile character, and would require electronic communication between the equatorial ligand and the axial coordination sites of the metal atom. We have substituted H2O in B12a with the ambidentate nucleophiles SCN−, SeCN−, NO2− and S2O32−, examined the UV/Vis spectra of the resultant complexes, crystallised them, and determined their structures by X-ray diffraction methods. The UV/Vis spectra of these complexes, as well as those of H2OCbl+, SO3Cbl− and MeCbl, were fitted by Gaussian functions. The principal bands move to lower energy in response to an increase in donation of electron density from the axial ligand, demonstrating direct electronic communication between the axial and the equatorial ligands. In the solid state, the thiocyanato ligand in SCNCbl is coordinated through N, although 13C NMR spectroscopy shows that the complex exists as a mixture of two linkage isomers in solution. SeCN−, NO2− and S2O32− are coordinated through the softer available donor in each case (Se, N and S, respectively). There is a regular ground-state trans effect such that as the donor power of the β-ligand increases, the trans Co−Nax bond length increases. A survey of the structures available in the CSD shows that this preference for the softer donor atom in ambidentate nucleophiles is not unusual in CoIII complexes. The Co−N bond length in SCNCbl is marginally long for coordination to CoIII, but the axial bond lengths of the other complexes are as expected. Hence, whereas the corrin macrocycle clearly imparts lability on CoIII, presumably by transfer of electron density onto the metal atom, this is insufficient to have a major effect on the ground-state structures of its complexes. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
PHASE BEHAVIOUR OF PHOSPHINOPOLYACRYLATE SCALES INHIBITOR

Abstract The influence of the Ca++ and inhibitor concentrations, pH, and temperature on the phase behaviour and precipitation yield of a phosphinopolyacrylate scale inhibitor, PPAA, has been studied. The results are interpreted in terms of the chemical processes governing PPAA-Ca++ complexation, and evidence for the role of inhibitor molecular weight in determining the degree of precipitation is produced. Comparative adsorption and precipitation squeezes, carried out in sandpacks, demonstrate that significant enhancement of the treatment lifetime can be achieved when conditions giving extensive inhibitor precipitation are used. The sandpack experiments and dissolution studies on the precipitated inhibitor both suggest strongly that kinetic phenomena influence the return level of inhibitor in the field. Together these studies point the way to approaches for optimising inhibitor precipitation squeeze treatments in order to control scale deposition in petroleum reservoirs.
Process Optimization for the Preparation of Activated Carbon from Jatropha Hull Using Response Surface Methodology

Abstract Preparation of activated carbon has been attempted using CO2 as the activating agent from Jatropha hull, one of the popular feed stocks for biodiesel manufacture. The response surface methodology technique is utilized to optimize the process conditions. The influences of the three major parameters, activation temperature, activation time, and CO2 flow rate on the properties of activated carbon, are investigated using analysis of variance to identify the significant parameters. The optimum conditions for preparation of activated carbon has been identified to be an activation temperature of 950°C, activation time of 40 min, and CO2 flow rate of 500 ml/min, an iodine number of 1,008 mg/g, and a yield of 18% were obtained, respectively. The BET surface area evaluated using nitrogen adsorption isotherm for the optimal sample corresponds to a 1,207 m2/g, with the pore volume of 0.86 cc/g. The activated carbon is heteroporous with the micropore volume contributing to 58%.
Performance and thermal behavior of sodium-sulfur cell under high current density operations

Performance and thermal behavior of the sodium-sulfur cell of a central sodium tube type under high current density operations are investigated by thermal modeling and calculations and experimental verification. The following are clarified by comparing calculated results with experimental ones: the cell temperature varies widely during the charge-discharge operations, and it becomes maximum at the end of discharge; the temperature distribution in the cell is roughly estimated from the measured value at the surface of the cell container; a hypothetical maximum of the energy efficiency is estimated by the calculation; though the thermal stress applied to the beta/sup ''/ -alumina solid electrolyte tube is small, the thermal fatigue of sealing parts of the cell and corrosion of a metal container of the sulfur electrode are accelerated under high current density operations; dynamic behavior of the cell when the cell is short-circuited is investigated by experiments and calculations, and it is indicated that, in consequence of the high short-circuit current, the temperature rise becomes extremely high depending on the external resistance and the starting point of discharge depth.
Ionomers: Two formation mechanisms and models

The FT IR spectra for different degrees of neutralization of ionomers based on poly(ethylene–methacrylic acid) copolymer were obtained. They involve the alkali metal ions (such as lithium, sodium, potassium, rubidium, and cesium), the alkaline earth metal ions (such as magnesium, calcium, strontium, and barium), and the transition metal ions (zinc and copper). Through the analysis of these spectra it can be deduced that there are two formation mechanisms and corresponding models for the ionomers: a cluster–multiplet model and a coordinated complex model. Also, it can be seen that the metal cations play an important role in the structure of an ionomer. By comparing the spectra of the metal ionomers at different temperatures as well as the spectra of the metal ionomers before and after water immersion, the existence of the two formation mechanisms and models can be inferred further.
Assessing the susceptibility of alpine soils to erosion using soil physical and site indicators

Soil erosion in mountainous regions is a key issue in land use planning, and this is particularly true in the Alps where intense anthropogenic influences at low elevations and abandonment in higher regions often coexist to affect soils. Natural hazard and risk assessment are essential given the density of settlements and associated facilities. Soil loss due to water erosion is very common and is becoming more frequent as a consequence of climate change which affects precipitation regimes, frequency of extreme meteorological events, snow melt and vegetation. In this study, we describe the production of a map showing susceptibility to soil erosion in the Aosta Valley (northwest Italian Alps). Most research on slope instability has focused on rock failures, but we investigated upper soil horizons by analysing chemical and physical properties, which could contribute to slope instability. The steps involved in creating the map are explained, and these involved GIS overlay, sampling, soil description, selection of relevant chemical and physical indicators of soil susceptibility to erosion, and overall erosion susceptibility assessment. The resultant indicator values correspond well with field observations to thus validate the methodology and demonstrate its usefulness in land use planning and management in Alpine areas.