Miracle-dz/UniFAR-FTUs huggingface dataset:
Particles Formation Using Supercritical Fluids

The particle precipitation into micro and nanoparticles has been an active research field for decades (Chattopadhyay & Gupta, 2001; Kalogiannis et al., 2005; Rehman et al., 2001; Reverchon, 1999; Velaga et al., 2002; YeoL or using it as antisolvent, the SAS technique (Supercritical AntiSolvent); the choice between one or another depends on the active substance high or low solubility in the supercritical fluid. The RESS process consists of solubilising the active ingredient of interest in the supercritical fluid and then rapidly depressurising this solution through a nozzle, thus causing the precipitation, extremely fast, of this compound. In other words, the process is based on the transition of active compound from soluble to insoluble state when the carbon dioxide passes from the supercritical to the gaseous phase. This technique has been applied on the particle precipitation and co-precipitation of many active ingredients/polymers (Kongsombut et al., 2009; Sane & Limtrakul, 2009; Turk et al., 2006; Vemavarapu et al., 2009; Wen et al., 2010). The SAS technique, in all its variants, generally consists of spraying a solution of the solute to be precipitated into the supercritical fluid. The mass transfer behavior of the droplets is thought to be a key factor affecting particle morphology (Werling & Debenedetti, 1999). The volumetric expansion of the solvent reduces the solvation capacity of the solvent, causing the supersaturation of the liquid phase and the consequent generation of the particles. The SAS process has been carried out for many particles precipitation and polymeric encapsulation of particles of active ingredients (Ai-Zheng et al., 2009; Chong et al., 2009a;
CHARACTERIZATIONS OF W-DOPED (Ba0.5Sr0.5)TiO3 THIN FILMS USING LaNiO3 ELECTRODE

ABSTRACT The (Ba0.5Sr0.5)TiO3 thin films were deposited onto LaNiO3 by RF-magnetron sputtering at 550°C. The influence of W content on microstructure and electrical properties of BST films were investigated. The surface and grain size become smoother and smaller as the W content increased. Besides, the dielectric constant, tunability, dissipation factor, and leakage current decreased when the W content increased. The 1% W is the optimal doping concentration. The resultant BST film, with proper dielectric constant and leakage current, has a tunability of 32%, a dissipation factor of 0.006, a FOM value of 53.3 under applied field of 450 kV/cm.
Coaxial structured collagen–alginate scaffolds: fabrication, physical properties, and biomedical application for skin tissue regeneration

Collagen is the most promising natural biomaterial and has been used in various tissue engineering applications for skin, bone, and cartilage because it provides good biocompatibility and low antigenicity. Although collagen is an excellent candidate material for various biomedical applications, its difficult processability and mechanical properties have remained important limitations. To overcome the problems, several methods including indirect printing combined with a sacrificing mold and low-temperature printing were suggested. However, it is difficult to fabricate precisely controlled 3D pore structure using the methods. In a previous study, we introduced a three-dimensional (3D) pore-structure-controlled collagen scaffold fabricated by a 3D dispensing system supplemented with a cryogenic and freeze-drying system. The fabricated scaffold had remarkably good cellular behaviour (cell migration and differentiation) but poor mechanical stability due to the highly porous structure consisting of micro-sized strands and poor mechanical nature of collagen. To overcome this deficiency, we designed a hybrid (core/shell) scaffold composed of an outer collagen and an inner alginate. The collagen/alginate scaffolds exhibited good structural stability (core–shell structure), increased Young's modulus about seven times compared to pure collagen scaffold under a similar pore-structure, and resulted in good cell viability, similar to a pure collagen scaffold. In an in vivo test, the hybrid scaffold was used as a dermal substitute and provided good granulation tissue formation and rapid vascularisation.
Influence of Side-Chain on Structural Order and Photophysical Properties in Thiophene Based Diketopyrrolopyrroles: A Systematic Study

In this work, we have synthesized a series of TDPP derivatives with different alkyl groups such as n-hexyl (−C6H13) 3a, 2-ethylhexyl (-(2-C2H5)C6H12) 3b, triethylene glycol mono methyl ether (-(CH2CH2O)3cH3, TEG) 3c, and octadodecyl (-(8-C8H17)C12H22) 3d. N,N dialkylation of thiophene-diketopyrrolopyrrole (TDPP, 1) strongly influences its solubility, solid state packing, and structural order. These materials allow us to explicitly study the influence of alkyl chain on solid state packing and photophysical properties. TDPP moiety containing two different alkyl groups 3e (TEG and 2-ethylhexyl) and 3f (TEG and n-hexyl) were synthesized for the first time. The absorption spectra of all derivatives exhibited a red shift in solid state when compared to their solution spectra. The type of alkyl chains leads to change in the optical band gaps in solid state. The fluorescence study reveals that TDPP derivatives have strong π–π interaction in the solid state and the extent of bathochromic shift is due to combinatio.
Theoretical Study of Size Effects on Surface Chemical Properties for Nanoscale Diamond Particles

Nanodiamond has displayed some unique physical and chemical properties compared to bulk diamond, which broadens its applications in various areas. However, a more detailed picture of nanodiamond quantum confinements is still missing from a theoretical point of view. This investigation presents a study where the effects of one-dimension (i.e., diamond thin films) and three-dimension (i.e., nanodiamond particles) confinement on surface reactivity, and properties, have been calculated using density functional theory (DFT) and tight binding density functional theory (DFTB) methods. Surface specific parameters like (i) surface C–H bond length, (ii) atomic charges, (iii) H adsorption energy, (iv) highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), (v) band gap, and (vi) Fukui functions were thereby carefully calculated and compared. For both the one-dimensional diamond thin films of different surface planes, quantum confinements have strong influences on these factors from .
CO Adsorption and Oxidation on N-Doped TiO2 Nanoparticles

In order to oxidize CO to CO2 during the process of steam pyrolysis nuclear graphite waste, the adsorption and oxidation of a CO molecule on undoped and N-doped TiO2 nanoparticles has been studied by first-principles calculations, including the adsorption energies, bond lengths, local density of states (LDOSs), and the charge density difference (CDD). In the adsorption process, two electrons transfer from CO to the particle resulting in the reduction of the Ti sites. CO2 and carbonate form during the adsorption process on the dangling oxygen atom. The CO over the undoped and N-doped nanoparticles forms CO2 by detaching the dangling oxygen atom. Less than 0.22 eV energy gained can drive the CO2 away to a distance greater than 3.01 A. Therefore, the CO molecule can be oxidized to CO2 by TiO2 nanoparticle, and the physically adsorbed CO2 molecule can spontaneously dissociate at room temperature, apart from the energies released in the adsorption process. The adsorption energy for an undoped particle is −0.93.
Pressure-Induced Intercalation of Alcohol Molecules into a Layered Titanate

Novel pressure-induced intercalation of alcohols into a layered titanate has been discovered using a diamond-anvil cell and in situ X-ray diffraction measurement. The lepidocrocite(γ-FeOOH)-type titanate containing pentylammonium ions exhibited uniaxial expansion of 0.27 nm in methanol at 1 GPa and 0.23 nm in ethanol at 2 GPa, suggesting an intercalation of the alcohol molecules into the interlayer gallery. The expansion was reversible without a significant hysteresis of pressure.
Thermochemistry and Kinetics of C2H3+ 02 Reactions

Abstract Kinetics and products are predicted for reactions of C2H3 + 02 by using a new Q-formalism of Bimolecular Quantum-RRK. theory. Association forms a chemically activated adduct, ( C2H3OO), which may isomerize one or more times to other hot isomers before decomposing or being stabilized. At low temperatures and pressures, HCO + H2CO are predicted to be formed without thermal intermediates, as observed by Gutman and co-workers. At atmospheric pressure, however, collisional stabilization of C2H3OO and its subsequent thermal reactions can be important. Glyoxal + H and C2H2 + HO, are predicted to be the next most important products of C2H3 + 02 association. All of these rate constants decrease significantly at high temperatures where ( C2H3 OO)* reverts to reactants preferentially. Above 1500 K, Ihe dominant products could be C2H2 + H02 formed directly by pressure-dependent H-atom transfer.
Crystal-size dependence of illite-smectite isotope equilibration with changing fluids

Differences in equilibration rates among crystals of different sizes may be used to deduce paleofluid changes over time if the crystal-growth mechanism is known. To explore isotopic equilibration rates as a function of illite growth, we studied B-isotope changes during illitization of smectite. Montmorillonite (<2.0 µm SWy-1, K saturated) was reacted with aqueous boric acid (1000 ppm B) at 300°C, 100 MPa in sealed Au capsules (1:1 fluid:mineral ratio). The initial fluid was 0‰ (NBS 951 standard) but after R1 ordering occurred (65 days of reaction) the fluid was changed to −7‰ in order to examine the rate of isotopic re-equilibration. Samples were taken intermittently throughout the experiment. Each aliquot was NH4 exchanged and size separated into fine (<0.2 µm), medium (0.2–2.0 µm) and coarse (>2.0 µm) fractions. The isotopic composition of B in the tetrahedral sheet was then measured for comparison with the predicted equilibrium values.The fine fraction showed equilibrium isotope ratios within 10 days, indicating that small, newly nucleated crystals precipitate in equilibrium with the fluid under supersaturated, closed conditions. These fine-fraction minerals did not re-equilibrate when the fluid was changed. The medium fraction gradually equilibrated with the initial fluid as illite grew to values >50%, but did not re-equilibrate with the later fluid. The coarse fraction was slow to begin recrystallization, perhaps due to dissolution kinetics of large crystals or the presence of detrital contaminants. However, it showed the fastest rate of isotopic change with crystal growth after R1 ordering. We conclude that at 300°C, the initial B–O bonds formed in illite are stable, and isotopic re-equilibration only occurs on new crystal growth. Therefore, different isotope ratios are preserved in different crystal size fractions due to different rates of crystal growth. Large crystals may reflect equilibrium with recent fluid while smaller crystals may retain isotope compositions reflecting equilibrium with earlier fluids.
Heating-Induced Evolution of Thiolate-Encapsulated Gold Nanoparticles: A Strategy for Size and Shape Manipulations

A heating treatment strategy for inducing size and shape change of composite nanoparticles in solutions is described. The composite nanoparticles are ∼2 nm gold cores encapsulated with alkanethiolate monolayers. The development of abilities in size and shape controls constitutes the motivation of this work. We demonstrated a remarkable evolution of the preformed particles in solutions toward monodispersed larger core sizes with well-defined and highly faceted morphologies. The particles thus evolved were encapsulated with the thiolate shells, and exhibited striking propensities of forming long-range ordered arrays. The morphological and structural evolutions were characterized using transmission electron microscopy, X-ray diffraction, UV−vis and infrared spectroscopies. Although temperature-driven crystal growth is known for nonencapsulated particles, the evolution of the thiolate-encapsulated nanoparticles in solutions into well-defined morphologies represents an intriguing example of temperature manipul.
Preparation, hybrid formation with single-walled carbon nanotube, and film morphology of pyrene-containing polysiloxanes

Palladium-catalyzed coupling reactions of bis(tributylstannyl)pyrene and diethynylpyrene with α,ω-di(bromothienyl)oligo(dimethylsiloxane) gave the corresponding polymers whose backbones were composed of pyrene-containing π-conjugated units and oligo(dimethylsiloxane) chains. These polymers exhibited red-shifted photoluminescence bands in solutions, probably due to the intramolecular stacking of the π-conjugated chromophores. Ball milling of the polymers with single-walled carbon nanotube (SWNT) afforded the soluble polymer-SWNT hybrid substances. Film morphology of the polymers was investigated by atomic force microscopy, showing the microphase-separated structure.
Influence of site conditions and management on different soil organic matter (som) pools

Basing on both a site gradient as well as a gradient in management intensities the influence of these factors on different SOM pools was investigated: (A) a very easily decomposable C pool, (B) a C pool which is related to clay fraction and representing a relatively inert pool, (C) a C pool which is not, or only loosely connected to the mineral soil part representing the intermediates between the extreme C pools (A) and (B). The decomposable C pool was measured by the parameter of hot water extractable carbon (HW-C). The clay related and not clay related SOM pools were isolated by a combined fractionation according to both particle sizes (clay fraction < 1 μm and 1 – 2 μm) and specific densities (light fraction < 1.8 g/cm3 and 1.8 – 2.0 g/cm3). Fertilization increases easily decomposable SOM pools reflected in C content of a hot water extractable SOM fraction and in mass of specific light SOM fractions but to a certain extent the C pool associated with clay minerals as well. At comparable management (fertilization) levels transformation conditions at a site (temperature and precipitation) have an influence on the accumulation of the decomposable SOM pool (effective biological transformation time – WMZ)
PHYSICOCHEMICAL CHARACTERIZATION OF HAZELNUT HUSK RESIDUES WITH DIFFERENT DECOMPOSITION DEGREES FOR SOILLESS GROWING MEDIA PREPARATION

In this study, the main physical, physiochemical, and chemical properties of hazelnut husk have been determined for the suitability as a container growing medium. Four substrates were prepared based upon decomposition degree: raw (H1), medium decomposed (H2, H3), and strongly decomposed hazelnut husk samples (H4), to determine the optimum growing medium parameters. Particle size was the key parameter to determine the physical properties, which was decreased with the increasing decomposition degrees. The main physical parameters were in the ranges for the ideal growing medium characteristics for H4. Except for raw material (H1), chemical characteristics such as pH, electrical conductivity (EC), carbon (C)/nitrogen (N), and nutrients were within acceptable ranges. The results indicated that hazelnut husk could be an alternative growing media component for containerized crops, if optimum particle size within the range of 0-2mm is obtained, for both aeration and water holding requirements.
Strain-hardening effect of graphene on a chitosan chain for the tissue engineering

We report the results of the chitosan dimer study, the mechanism of its interaction with the carbon nanostructures and also the mechanical properties of the chitosan/graphene, chitosan/nanotube complexes using the density function and the molecular dynamic methods. It was established that the physical adsorption of the chitosan with graphene is carried out by the Van der Waals interaction between the hexagonal links of the chitosan with the hexagonal cell of the atomic grid of graphene and nanotube.
STABLE-ISOTOPE-ASSISTED NMR STUDIES ON 13C-ENRICHED SIALYL LEWISX IN SOLUTION AND BOUND TO E-SELECTIN

We report the determination of the solution structure and dynamics of 13C-enriched Neu5Acα2−3Galβ1−4(Fucα1−3)GlcNAc (sialyl Lewisx), together with its bound-state conformation in association with E-selectin. The availability of 13C-enriched material enabled both the measurement of trans-glycosidic 13C−13C coupling constants as conformational probes in the tetrasaccharide and the application of three-dimensional nuclear Overhauser effect 13C−1H heteronuclear single-quantum correlation experiments for the measurement of intramolecular transferred nuclear Overhauser effects (TRNOEs) characterizing the bound-state conformation of the ligand. The additional dispersion afforded by the third (13C) dimension permitted straightforward identification and quantitation of these TRNOEs, and several TRNOEs were identified that had not previously been reported. The bound-state conformation of the ligand, determined by use of a heteronuclear full-relaxation matrix analysis of the TRNOE data, differs significantly from th.
Palladium-Catalyzed Addition of Dialkylamines to Linalyl Acetate and Related Compounds

Abstract Pd(PPh3)4 catalyzed reaction of linalyl acetate with diethylamine gave N, N-diethylgeranylamine as a main product (E:Z = 90:10). The reaction of linalyl acetate with various amines gave their corresponding products. For example, the reaction of aniline with linalyl acetate gave N-geranylaniline in 100% stereoselectivity. The reaction of linalyl methylcarbonate with diethylamine using a Pd(0) catalyst similarly gave N, N-diethylgeranylamine (E:Z = 92:8).
Thermal Diffusivities and Thermal Conductivities of UO2-Gd2O3

Thermal diffusivities of samples of UO2 and UO2 doped with 3, 5, 7 and 10 w/0 Gd2O3 were measured over the temperature range of 298~2,023 K by a laser flash method. Then thermal conductivities were calculated from them. The thermal conductivity decreased with increasing Gd2O3 content at low temperatures, while it was independent of Gd2O3 content at high temperatures. An expression of the thermal conductivity was proposed for (U, Gd)O2 solid solution as a function of Gd2O3 content and temperature by applying Klemens' model.
Reactivity of large carbon clusters: spheroidal carbon shells and their possible relevance to the formation and morphology of soot

The reactivity of bare carbon clusters produced by laser vaporization has been studied by a fast-flow gas-phase reactor followed by F/sub 2/ excimer laser ionization and time-of-flight mass analysis. Although most small carbon clusters (C/sub n/, with n < 40) were found to be highly reactive with such small molecules as NO, SO/sub 2/, and CO, the larger even n clusters (40 < n < 80) were found to be relatively inert. This lack of reactivity was most pronounced for C/sub 60/ (Buckminsterfullerene). Inertness of the large even C/sub n/ clusters is evidence that they have closed into edgeless, spheroidal shells composed of 12 pentagonal rings and n/2 - 10 hexagonal rings. The possible role of similar shell structures in the formation and morphology of soot is considered. 16 references, 4 figures.
Semiquantitative Process Screening for the Biocatalytic Synthesis of d-Xylulose-5-phosphate

In this paper we report a method of semiquantitative process screening or route scouting developed to reduce the number of potential process flowsheets for a multistep biocatalytic conversion. Using the dual-enzyme-based synthesis of d-xylulose- 5-phosphate as a model, a variety of possible processes was identified. Using data from a limited number of key experiments describing important process attributes, a screening procedure was proposed. Unattractive processes were eliminated early, and the best candidates were put forward as potential options for subsequent development. The method should prove applicable to a range of process synthesis problems.
Size of a polymer molecule in solution. Part 1.—Excluded volume problem

A study is made of the probability distribution of the end to end distance R of a polymer of N segments, length Nl=L, and of self repulsion ω. A simple method, capable of adoption in more complicated problems, is developed, using the idea of an effective step length.The mean square value of R2 is developed as a series which for large L is R2=ω2/5L6/5l2/5(1.12 + 1.05 + 1.03 +…). The probability distribution is developed in terms of the dimensionless parameter x=R2/l2/5ω2/5L6/5, and for small x, logp(x)–x([graphic omitted]+[graphic omitted]+[graphic omitted]+…) but for large x a definite asymptotic form is derived log p(x)=–(⅗)π1/2/3 x[graphic omitted].
Accurate calculation of Auger rates in infrared materials

The Auger recombination rates in small-gap semiconductor alloys are calculated using full band structures with electron–electron interactions in Coulomb and phonon fields. We find that the results are sensitive to band structure details and the calculated minority carrier lifetimes can differ by two orders of magnitude depending on the approximations used to describe the energy bands and wave functions. The full band structure results agree well with experiments in Hg0.78Cd0. 22Te. Similar calculations were carried out for lifetimes in In0.67Tl0. 33P, In0.85Tl0. 15As, and In0.92Tl0. 08Sb as a function of temperature. The minority carrier lifetimes in In0.67Tl0. 33P and In0.92Tl0. 08Sb are shorter than that in Hg0.78Cd0. 22Te at all temperatures. However, the low-temperature minority carrier lifetime in In0.85Tl0. 15As is an order of magnitude longer than that in Hg0.78Cd0. 22Te. Our calculations further suggest a possibility of increasing the lifetimes of minority carriers by decreasing the density of states insid.
Pegylated thermally responsive block copolymer micelles and nanogels via in situ RAFT aqueous dispersion polymerization

A very straightforward approach was developed to synthesize pegylated thermoresponsive core-shell nanoparticles in a minimum of steps, directly in water. It is based on RAFT-controlled radical crosslinking copolymerization of N,N-diethylacrylamide (DEAAm) and N,N′-methylene bisacrylamide (MBA) in aqueous dispersion polymerization. Because DEAAm is water-soluble and poly(N,N-diethylacrylamide) (PDEAAm) exhibits a lower critical solution temperature at 32 °C, the initial medium was homogeneous, whereas the polymer formed a separate phase at the reaction temperature. The first macroRAFT agent was a surface-active trithiocarbonate based on a hydrophilic poly(ethylene oxide) block and a hydrophobic dodecyl chain. It was further extented with N,N-dimethylacrylamide (DMAAm) to target macroRAFT agents with increasing chain length. All macroRAFT agents provided excellent control over the aqueous dispersion homopolymerization of DEAAm. When they were used in the radical crosslinking copolymerization of DEAAm and MBA, the stability and size of the resulting gel particles were found to depend strongly on the chain length of the macroRAFT agent, on the concentrations of both the monomer and the crosslinker, and on the process (one step or two steps). The best-suited experimental conditions to reach thermosensitive hydrogels with nanometric size and well-defined surface properties were determined. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2373–2390, 2009