Miracle-dz/UniFAR-FTUs huggingface dataset:
Triethanolamine/KI: A Multifunctional Catalyst for CO2 Activation and Conversion with Epoxides into Cyclic Carbonates

Abstract A catalytic system of triethanolamine/potassium iodide (KI) was proved to be efficient for the chemical fixation of CO2 with epoxide. It was found that triethanolamine with dual function could activate both CO2 and epoxides. Effects of parameters such as catalyst molar ratio and amount, reaction time, pressure, and temperature were studied systematically. As a result, 99% propylene oxide conversion as well as 99% propylene carbonate selectivity could be obtained under the optimal reaction condition. Furthermore, the catalyst was found to be applicable to a variety of terminal epoxides, providing the corresponding cyclic carbonates in good yields and selectivity. Moreover, the catalyst could be reused five times without loss of activity. This work presents an example of a cheap and efficient catalyst for the chemical fixation of CO2 to high-value chemicals, which could help to improve the catalytic efficiency and decrease cost of products for larger applications. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource: Full experimental and spectral details. ] GRAPHICAL ABSTRACT
Adhesion measurements on patterned elastomeric surfaces

Since the discovery of the gecko's hairy attachment pads, scientists tried to mimic these surface patterns due to the unique adhesion properties. Lately, scientists succeeded to fabricate artificial adhesives, which show similar complexity in geometry and achieved adhesive forces, exceeding the sticking forces of geckos. Due to the increasing commercial interest, a race has started to fabricate more complex surface patterns. However, due to this race some fundamental scientific aspects have fallen into oblivion, e.g. the distinction between real effects and measurement artefacts. In this work, the adhesion of patterned surfaces was investigated using different probe geometries. It was shown that the adhesion changes with the number of contacts due to material transfer between sample and probe. Adhesion measurements with flat and spherical probes on patterned surfaces were compared and the angle dependent adhesion was determined. Flat tip pillars showed a large tilt angle dependency, while pillars with spherical and mushroom shaped tips exhibited angle independent pull-off forces. Due to the angle dependencies, spherical probes tended to underestimate the adhesion of patterned surfaces compared to well-aligned flat probes. Flat probe measurements allowed a closer investigation of contact phenomena and yielded new information on adhesion and mechanical properties of patterned surfaces. These results may help in a more successful design of bioinspired adhesives. Seit Entdeckung der Oberflachenstruktur von Geckozehen haben Wissenschaftler versucht, diese wegen ihrer einzigartigen Hafteigenschaften zu kopieren. Kurzlich ist es gelungen, Haftsysteme mit ahnlich komplexen Strukturen zu entwickeln, die die Haftkrafte des Geckos sogar ubertreffen. Aufgrund des wachsenden kommerziellen Interesses werden immer komplexere Strukturen hergestellt. Dabei werden jedoch fundamentale wissenschaftliche Prinzipien vernachlassigt: der Unterschied zwischen Effekt und Messartefakt. In dieser Arbeit wurde die Adhasion strukturierter Oberflachen mit unterschiedlichen Prufkorpergeometrien bestimmt. Dabei wurde gezeigt, dass sich die Haftkraft aufgrund von Materialtransfer mit der Anzahl der Kontakte zwischen Prufkorper und Probe andert. Adhasionsmessungen mit spharischen und flachen Prufkorpern wurden verglichen. Flache Prufkorper erlaubten dabei eine Quantifizierung der winkelabhangigen Adhasion. Strukturen mit flachen Enden zeigen, im Gegensatz zu Strukturen mit spharischen und pilzformigen Enden, winkelabhangige Adhasion. Aus diesem Grund wird bei Adhasionsmessungen mit spharischen Prufkorpern die Haftkraft strukturierter Oberflachen oftmals unterschatzt. Messungen mit flachen Prufkorpern ermoglichen eine genauere Untersuchung von Kontaktphanomenen und liefern zusatzliche Informationen uber Adhasion und mechanische Eigenschaften von strukturierten Oberflachen. Diese Ergebnisse konnen dabei helfen, bioinspirierte Haftsysteme weiter zu optimieren
Structure and properties of organoclay/EPDM nanocomposites: Influence of ethylene contents

Four organoclay (OC)/ethylene–propylene–diene rubber (EPDM) nanocomposites with different ethylene contents were prepared by melt blending. X-ray diffraction spectrum (XRD) and transmission electronic microscope (TEM) photos showed that OC/EPDM nanocomposites were intercalated, and the ethylene content had little influence on the dispersion of OC. The addition of OC prolonged the optimum cure time and reduced the crosslink density of OC/EPDM. The improvement in tensile strength of OC/EPDM nanocomposites with high ethylene contents (67–70%) was larger than that of OC/EPDM nanocomposites with low ethylene contents (52–52.5%). XRD results of the stretched samples testified that the extension promoted orientation of silicate layers, and induced crystallization of polyethylene (PE) segments in OC/EPDM nanocomposites with high ethylene contents. The highly oriented micro-fibrillar structure and more oriented amorphous chains, which resulted from strain-induced crystallization of PE segments and the orientation of clay layers in OC/EPDM nanocomposites with high ethylene contents (67–70%), should be responsible for larger improvement in tensile strength than that of those nanocomposites with low ethylene contents (52–52.5%) © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 914–919, 2006
Auto-chemotactic micro-swimmer suspensions: modeling, analysis and simulations

Microorganisms can preferentially orient and move along gradients of a chemo-attractant (i.e., chemotax) while colonies of many microorganisms can collectively undergo complex dynamics in response to chemo-attractants that they themselves produce. For colonies or groups of micro-swimmers we investigate how an "auto-chemotactic" response that should lead to swimmer aggregation is affected by the non-trivial fluid flows that are generated by collective swimming. For this, we consider chemotaxis models based upon a hydrodynamic theory of motile suspensions that are fully coupled to chemo-attractant production, transport, and diffusion. Linear analysis of isotropically ordered suspensions reveals both an aggregative instability due to chemotaxis that occurs independently of swimmer type, and a hydrodynamic instability when the swimmers are "pushers". Nonlinear simulations show nonetheless that hydrodynamic interactions can significantly modify the chemotactically-driven aggregation dynamics in suspensions of "pushers" or "pullers". Different states of the dynamics resulting from these coupled interactions in the colony are discussed.
Adhesion of chromium films to soda lime glass

A comprehensive empirical study of chromium-glass adhesion is described. The experimental matrix includes variations in cleaning procedures, substrates, and vacuum treatments. Particular attention is given to glow discharge ambients, including active and noble gases. The effect of substrate heating was also investigated. The dynamic peel adhesion test was used for comparison of adhesion strengths, and this technique is described. The study was directed toward finding a process compatible with high-throughput production techniques. Quantitative data are given that compare various deposition regimes, and results show a significantly improved chromium deposition process for this particular class of substrates. Some general comments are made regarding the adhesion mechanism and other related phenomena.
Gas adsorption isotherms from composition and flow–rate transient times in chromatographic columns. III. Effect of gas viscosity changes

A method of determining binary adsorption isotherms from the flow–rate and composition responses of a packed column to a step change in input composition has been described previously by Mason and Buffham (1996 Proc. R. Soc. Lond. A 452, 1263–1285). The method involves adding a small perturbation stream to a carrier gas mixture passing through a chromatographic column. The bulk of the observed effects arise from the small change in composition of the gas in the column caused by adding the perturbation gas. However, the increase in flow caused by adding the perturbation stream raises the pressure in the column and, under certain circumstances, this increase of pressure can cause significant adsorption (Mason and Buffham 1996 Proc. R. Soc. Lond. A 452, 1287–1300). Apart from changing the amount of adsorption, the change in composition also alters the viscosity of the gas in the column and this too can affect the column behaviour. The change in viscosity is small but can have two consequences. The first is minor and is a small shift in the mean pressure in the column. The second effect is peculiar to the apparatus used in the previous experiments. A capillary flowmeter was used to monitor flow and capillary flowmeters respond to viscosity as well as flow. The effect of the change in viscosity in the capillary flowmeter is significant, even for gas mixtures with almost linear variation of viscosity with composition. Both effects can be corrected for by theory. The second effect might be removed by the addition of a delay line between the column and the flowmeter. A delay line is simply an empty tube which delays the arrival of gas of different viscosity and enables the capillary flowmeter to act as an ideal flowmeter for the limited period that the composition front is passing through, and leaving, the column. Precise isotherms for nitrogen–argon mixtures on 5A molecular sieve at 50 °C have been obtained and they are compared with binary Langmuir isotherms. The comparison is in terms of the gradients of the isotherms of each of the two components. Partial differentials of the amounts adsorbed in terms of the concentrations of nitrogen and argon are also obtained.
Response of upland rice to fertilizer phosphorus and its residual value in an ultisol

An effective and economically efficient phosphorus (P) management strategy requires accounting for the residual value of P fertilizer. Despite a great deal of research on soil P much remains unknown about the residual value of fertilizer P to upland rice in the humid tropics of Africa. A field experiment was conducted for six years (1993–1998) to determine the response of four promising upland rice cultivars to fertilizer P applied at 0, 45, 90, 135, and 180 kg P ha−1 as triple superphosphate (TSP) only once in 1993, and its residual value in 1994, 1995, 1996, and 1998. The experimental site was located on an Ultisol, low in available P, in the humid forest zone of Cote d'Ivoire. Grain yields of the rice cultivars were significantly increased by fertilizer P in 1993, and by the fertilizer P residues in the subsequent years although the magnitude of response decreased rapidly with time since the fertilizer was applied. The levels of Bray 1 extractable P in the soil fell below the critical value in the 1994 season in all treatments except those which received 135 and 180 kg P ha−1 in 1993, and fell below the critical value in all P treatments in the 1995 season. A decrease in available P coincided with decreased residual value of P fertilizer and the soil P test (Bray 1 P) appeared to predict well the crop response. Our results show that there was a rapid loss of available P in the Ultisol and it is suggested that annual application of light rates of soluble P is a better option than heavy application at one time.
In Situ Treatment of Cyanide‐Contaminated Groundwater by Iron Cyanide Precipitation

Groundwater contamination with cyanide is common at many former or active industrial sites. Metal–cyanide complexes typically dominate aqueous speciation of cyanide in groundwater systems, with iron–cyanide complexes often most abundant. Typically, metal–cyanide complexes behave as nonadsorbing solutes In sand–gravel aquifer systems in the neutral pH range, rendering cyanide relatively mobile in groundwater systems. Groundwater pump–and–treat systems have often been used to manage cyanide contamination in groundwater. This study examined the feasibility of using in situ precipitation of iron cyanide in a reactive barrier to attenuate the movement of cyanide in groundwater. Laboratory column experiments were performed in which cyanide solutions were passed through mixtures of sand and elemental iron filings. Removal of dissolved cyanide was evaluated in a variety of cyanide–containing influents under various flow rates and sand‐to‐iron weight ratios. Long‐term column tests performed with various cyanide–containing influents under both oxic and anoxic conditions, at neutral pH and at flow rates typical of sand–gravel porous media, yielded effluent concentrations of total cyanide as low as 0.5 mg/L. Effluent cyanide concentrations achieved were close to the solubilities of Turnbull's blue–hydrous ferric oxide solid solutions, indicating co‐precipitation of the two solids. Maximum cyanide removal efficiency was achieved with approximately 10% by weight of iron in the sand‐iron mixtures; higher iron contents did not increase removal efficiency significantly. Results obtained indicate that in situ precipitation is a promising passive treatment approach for cyanide in groundwater.
Modeling, scaleup and optimization of slurry bubble column reactors for Fischer-Tropsch synthesis

The hydrodynamic and mass transfer parameters of gaseous mixtures of N2 and He, used as surrogate components for CO and H2 respectively, were measured in three Fischer-Tropsch (F-T) liquids in the presence and absence of solid particles (Al2O3, FeOx). The data were obtained in a pilot-scale (0.29 m ID and 3 m high) slurry bubble column reactor (SBCR) within wide ranges of operating conditions covering those of F-T synthesis. The manometric method, the Transient Physical Gas Absorption technique and the Dynamic Gas Disengagement technique were employed to obtain the gas holdup, the volumetric liquid-side mass transfer coefficient and the gas bubbles Sauter mean diameter, respectively. Statistical experimental design was used to investigate the effect of these operating conditions on those parameters. The gas-liquid interfacial area appeared to control the mass transfer behavior of the SBCR operating in the churn-turbulent flow regime. A user-friendly simulator based on a comprehensive computer model for F-T SBCRs, taking into account the hydrodynamics, kinetics, heat transfer, and mass transfer was developed. Novel hydrodynamic and mass transfer correlations, covering wide ranges of reactor geometry, gas distributor types, and operating conditions were established using our experimental data and those available in the literature; and a new relationship between the axial dispersion of large gas bubbles and their average diameter were developed and included in the reactor model. All reactor partial differential equations, equation parameters along with the pertinent boundary conditions were simultaneously solved numerically using the finite elements method. Different kinetic rate expressions available in the literature for iron and cobalt-based catalysts were included in the simulator which was used to predict the effects of the operating conditions, such as catalyst concentration, pressure, temperature, H2/CO ratio, and superficial gas velocity on the performance of a F-T SBCR. The predictions showed that the performance of the reactor was strongly dependent on the catalyst type and the kinetic rate expression used. The simulator was also used to optimize the reactor geometry and operating conditions in order to produce 10,000 barrels per day of synthetic hydrocarbons.
Effect of horse meat consumption on iron status, lipid profile and fatty acid composition of red blood cell membrane: preliminary study

HORSE PORK BEEF n-3 n-6 n-9 Figure 1Fatty acids in meat products Figure 2Polynsaturated fatty acids in meat products Figure 3Omega 3 and 6 in meat products Horse meat is very low in fat and cholesterol (about 20% less) and it is a good source of polynsaturated fatty acids such as linoleic and α-linolenic acid (2). Limited data are available on the effect of the regular consumption on lipid profile, iron metabolism and fatty acids profile.
An evaluation of expansion equations for fluidized solid–liquid systems

Numerous equations can be found in the literature for the prediction of bed expansion during liquid–solid fluidization. There is no general agreement regarding which equation is the most accurate. In this work, fluidization experiments have been carried out with plastic and glass spheres of 11 different sizes, varying from 1.11 mm to 6.01 mm. Water was used as the fluidizing medium in all the experiments. Widely used correlations are compared and evaluated using the data collected in this work and certain long-standing data from the literature. A new equation with a simple and meaningful form is developed for the prediction of bed expansion in liquid fluidized beds of spheres. The proposed correlation is based on an extension of the fixed-bed friction factor concept to fluidized beds. The new equation has a number of advantages such as a wider operating range, improved accuracy, simple and continuous form, and a fundamental basis.
Organoleptic evaluation of jam prepared from organically grown papaya cv. Arka prabhat

An experiment was conducted to study the quality and shelf life of jam prepared from organically grown papaya cv. Arka prabhat. The maximum score for colour (7.76), flavour (7.40), taste (7.80) and overall acceptability (7.65) was recorded in jam prepared from fruits of plants applied with FYM 100% RDN. Overall acceptability was decreased with increase in storage period in all the treatments. The jam prepared from papaya can be stored upto 90 days under ambient conditions without any considerable loss in quality.
Improved theoretical dissociation energy and ionization potential for the ground state of the hydrogen molecule

A new 155‐term electronic wave function for the ground state of the hydrogen molecule has been selected which gives a more accurate Born–Oppenheimer potential energy curve in the range 3.2≤R≤7.2 bohr. The largest improvement 0.112 cm−1 has been found for R=4.8 bohr. The adiabatic corrections have also been calculated in the full range of R giving more accurate values. These new results have been employed to calculate the dissociation energies and ionization potentials for H2, HD, and D2. The agreement between resulting dissociation energies and recently published experimental data are excellent; the discrepancy is within the experimental error limits. For the ionization potential the agreement is fairly good, although not ideal. There is still room for improvement from both theoretical and experimental side.
High pressure and low temperature X-ray crystallography: the crystal structure of the molecular charge transfer salt α'- (bis(ethylenedithio)-tetrathiafulvalene)2AuBr2

An X-ray diffraction technique is described that allows determination of crystal structure and the variation of lattice parameters of single crystals as a function of hydrostatic pressure up to 14 kbar and of temperature from 300 K to 12 K. As an example of the technique results are presented on the molecular charge transfer salt α'-(BEDT TTF)2AuBr2 (BEDT-TTF = bis(ethylenedithio)-tetrathiafulvalene) to elucidate the nature of a structural phase transition which occurs at 250 K at ambient pressure and 7 kbar at 300 K. The transition, of second order, is characterized by the appearance of ½b* superlattice reflections at high pressure or low temperature but without any drastic change in the basic crystal structure. The isobaric thermal expansions and the isothermal compressibilities are anisotropic, being larger along a than along b and c, though of different magnitudes and directional properties, i. e. the effect of applying pressure at ambient temperature is not equivalent to lowering the temperature at ambient pressure. Transfer integral calculations show that marked dimerization along the stacking axis, already present at 300 K, is related to electronic localization.
Thermal particle image velocity estimation of fire plume flow

For the purpose of studying wildfire spread in living vegetation such as chaparral in California, a thermal particle image velocity (TPIV) algorithm for nonintrusively measuring flame gas velocities through thermal infrared (IR) imagery was developed. By tracing thermal particles in successive digital IR images, the TPIV algorithm can estimate the velocity field in a fire-plume flow. In this method, the thermal particle is assumed to be a virtual particle that corresponds to the "hot" pixel resolved in a digital image. Its signal is a temperature value measured by a thermal IR camera. Fire-plume experiments using alcohol and chamise ( Adenostoma fasciculatum ) as fuels and a computational simulation have been completed. A thermal IR camera was used to capture successive fire temperature images. Using these images, velocity fields were estimated by the TPIV algorithm. For numerical simulation, the computed detailed instantaneous velocity field was used to validate the field estimated by the TPIV algorithm. Results illustrate the applicability and performance of the TPIV algorithm in fire research.
NOx Formation in H2-CH4 Blended Flame Under MILD Conditions

In this article, NO production mechanisms for CH4-H2 combustion under MILD (moderate or intense low-oxygen dilution) conditions are studied using CDF and also zero-dimensional well stirred reactor (WSR) analysis. A H2/CH4 jet into a heated and diluted coflow is modeled in CFD analysis. The RANS equations with modified k − ϵ equations are solved in an axisymmetric 2D computational domain. The GRI2.11 full mechanism is considered to represent the chemical reactions. The effects of oxidizer oxygen concentration, fuel hydrogen content, and fuel jet Reynolds number are studied on NO formation reactions. Results show that the measurements are predicted with an acceptable accuracy. The NNH and N2O routes are the most important pathways in NO formation under MILD conditions. An increase in oxidizer O2concentration or decrease in fuel hydrogen content addressesthe decrease in importance of the mentioned NO formation routes.
Statistical associating fluid theory for chain molecules with attractive potentials of variable range

A version of the statistical associating fluid theory (SAFT) is developed for chain molecules of hard-core segments with attractive potentials of variable range (SAFT-VR). The different contributions to the Helmholtz free energy are evaluated according to the Wertheim perturbation theory. The monomer properties are obtained from a high-temperature expansion up to second order, using a compact expression for the first-order perturbation term (mean-attractive energy) a1. Making use of the mean-value theorem, a1 is given as the van der Waals attractive constant and the Carnahan and Starling contact value for the hard-sphere radial distribution function in terms of an effective packing fraction. The second-order perturbation term a2 is evaluated with the local compressibility approximation. The monomer cavity function, required for the calculation of the free energy due to the formation of the chains and the contribution due to association, is given as a function of a1. We analyse the equation of state for ch.