Miracle-dz/UniFAR-FTUs huggingface dataset:
Synthesis and characterization of MQ silicone resins

MQ silicone resins, which represent a broad range of hydrolytic condensation products of monofunctional silane (M) and tetrafunctional silane (Q), were synthesized by reaction of water glass with hexamethyldisiloxane. The optimum reaction time and the optimal reaction temperature is 30 min and 30–40°C, respectively. Concentrated hydrochloric acid is the best one among those catalysts tested. In large-scale experiments (420–1680 mL), the favorable feeding order is catalyst first, and then water glass, the mixture of hexamethyldisiloxane and ethanol last and most MQ silicone resin was observed. The structure of MQ silicone resin was characterized by FT-IR and GPC spectra. The MQ silicone resin shows narrow molecular weight distribution and the number average molecular weight of MQ silicone resin is 2917. The silicone pressure sensitive adhesive prepared from as-synthesized MQ resin has good tack (29#) and 180° peel adhesion (5.630N/20 mm). © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Measurement of the rubidium content in a standard reference sample applying isotope dilution in diode laser graphite furnace atomic absorption spectrometry

The reliability of the isotope dilution technique applied to diode laser graphite furnace atomic absorption spectrometry was tested by the determination of the Rb content in a NIST (National Institute of Standards and Technology) reference water (SRM 1640). For the measurements, the NIST water was spiked with different amounts of 87Rb. The signals of both naturally occurring Rb isotopes, 85Rb and 87Rb, were measured simultaneously by the use of two diode lasers. A total Rb content of 1.97 ± 0.03 ng ml−1 was found which compares very well with the reference value of 2.00 ± 0.02 ng ml−1.
Implementation of the Finite Volume Method for Calculating Radiative Transfer in a Pulverized Fuel Flame

Abstract The newly developed Finite Volume Method (FVM) was incorporated into a general pulverized fuel (PF) flame model to predict radiative heat transfer in furnaces. The code was applied to a benchmark test case where exact radiative heat transfer solutions were available and to a pilot scale front-firing tunnel furnace where flame measurements had been taken. The FVM predictions were found to approach the exact solutions in the benchmark case and compare well to the measured data in the pilot scale furnace. The results demonstrate the feasibility and potential of the FVM for radiation modelling in PF flames.
Metalorganic Chemical Vapor Deposition and Material Characterization of Lattice-Matched InAlN/GaN Two-Dimensional Electron Gas Heterostructures

InAlN/GaN two-dimensional electron gas (2DEG) heterostructures were successfully grown by metalorganic chemical vapor deposition. X-ray photoelectron spectroscopy and X-ray diffraction measurements revealed that the barrier layer consists of a ternary In0.18Al0. 82N alloy, a composition nearly lattice-matched to GaN. The bandgap energy of the In0.18Al0. 82N barrier layer was estimated to be approximately 4.3 eV by spectroscopic ellipsometry analysis. Electrical characterization results showed that 2DEG mobility can be improved with the insertion of a thin AlN layer at the InAlN/GaN heterointerface. Very high 2DEG densities of more than 2.6×1013 cm-2 and high 2DEG mobilities of 1170 cm2/(V s) were achieved for InAlN/AlN/GaN structures with the barrier thickness of more than 15 nm. These 2DEG properties are almost equal to the best ones ever reported for InAlN/GaN 2DEG structures.
Thermotropic liquid crystalline properties of amphiphilic branched chain glycolipids

Glycolipids are amphotropic liquid crystals forming lyotropic liquid crystals in aqueous solutions and thermotropic liquid crystals in their dry form. We report studies on the thermotropic properties of seven different neat glycolipids: four maltoside, two glucoside and one pyranoside lipids. Optical birefringence, electrical conductivity, differential scanning calorimetry, and dielectric spectroscopy measurements were employed to characterize the phase structures of the materials. In general, they exhibit a wide (>100°C) mesophase (smectic, columnar) range with low (0.01–0.04) birefringence. They have large (60–120) dielectric susceptibility basically proportional to the number of polar sugar heads. Depending on the temperature the relaxation frequency of the susceptibility varies between <100 Hz and >1 MHz, mainly determined by the hydrogen bonding between the polar sugar heads.
Spin relaxation in n-type ZnO quantum wells

We perform an investigation on the spin relaxation for n-type ZnO (0001) quantum wells by numerically solving the kinetic spin Bloch equations with all the relevant scattering explicitly included. We show the temperature and electron density dependence of the spin relaxation time under various conditions such as impurity density, well width and external electric field. We find a peak in the temperature dependence of the spin relaxation time at low impurity density. This peak can survive even at 100 K, much higher than the prediction and measurement value in GaAs. There also exhibits a peak in the electron density dependence at low temperature. These two peaks originate from the nonmonotonic temperature and electron density dependence of the Coulomb scattering. The spin relaxation time can reach the order of nanosecond at low temperature and high impurity density.
A New Sesquiterpenoid from the Rhizome of Curcuma zedoaria

122.6 and 156.1) indicated fusion of the furan ring with the 10-membered ring at the C-7 and C-8 positions. Finally, the presence of an epoxide ring was presumed to meet the number of unsaturations (tricyclic ring system) and the mole-cular formula. By comparison of chemical shifts with literature values, the epoxide ring was presumed to be at C-4 and C-5.
Uptake of Gas-Phase Ammonia. 1. Uptake by Aqueous Surfaces as a Function of pH

The uptake of gas-phase ammonia by aqueous surfaces was measured as a function of temperature, gas liquid interaction time, and pH in the range 0−13. Uptake measurements at low pH yielded values of the mass accommodation coefficient (α) as a function of temperature. The mass accommodation coefficient increases as the temperature decreases, from 0.08 at 290 K to 0.35 at 260 K. Time dependence of the uptake yielded values for the Henry's law constant. Uptake measurements at high pH indicate that an ammonia surface complex is formed at the interface. Codeposition studies in which an aqueous surface, initially at pH = 4, was simultaneously exposed to both gas-phase ammonia and SO2 were also performed. In such a codeposition experiment, the species entering the liquid neutralize each other and as a result the uptake of each species is enhanced. Modeling calculations indicate that the uptake of each species is in accord with bulk liquid-phase kinetics.
Thermal Properties of Alkali Bis(pentafluoroethylsulfonyl)amides and Their Binary Mixtures

Thermal properties of alkali bis(pentafluoroethylsulfonyl)amides, MPf2N (M = Li, Na, K, Rb, and Cs), and their binary mixtures have been revealed. Phase diagrams have been constructed for 10 binary systems, and their eutectic compositions and temperatures have been determined. It was found that the molten salt electrolytes with melting points in the intermediate temperature range (450 to 650) K are easily formed by mixing two kinds of single MPf2N salts.
Investigation of dietary fibre in some edible mushrooms from Macedonia

Analyzes seven kinds of edible wild Macedonian mushrooms for their total dietary fibre (TDF) content, according to the official Association of Official Analytical Chemists (AOAC) method for plants as well as according to Hackman’s method for material of animal origin. Elemental analysis (C, H, N) of TDF procedures was performed in order to confirm the uniformity of the isolated products. The TDF contents of the mushrooms as measured by the AOAC method (8.71 per cent dry wt.) were considerably greater than those determined using the Hackman method (5.53 per cent dry wt.). Two products were isolated, both with C and H contents very similar to chitin and cellulose. These products differ from cellulose as they contain N. The infra‐red (IR) spectra of the TDF isolates obtained according to both the applied methods were very similar to the IR spectrum of chitin. In all spectra cellulose is missing.
A new hierarchical model reduction-reduced basis technique for advection-diffusion-reaction problems

We extend previous work on the Hierarchical Model Reduction-Reduced Basis (HMR-RB) approach to an advection-diffusion-reaction problem. In comparison to the Boussinesq approach we do not neglect the dependency on the vertical direction but enhance the solution for the horizontal direction with appropriately chosen basis functions living on the vertical one. This is done by a combination of the frameworks of hierarchical model reduction [4] and the reduced basis methods [3]. We derive a new a posteriori error estimate and demonstrate in numerical experiments that few basis functions suffice to get good approximations.
Comparison of different models for phosphate sorption as a function of the iron and aluminium oxides of soils.

SUMMARY Phosphate sorption on topsoil and subsoil samples from different soils located in the eastern part of Germany was studied. Two models were fitted to sorption data obtained after 4 and 40 d of gentle shaking. The models differ with respect to the fractions of iron and aluminium (hydr)oxides that are considered and whether the phosphate initially sorbed in the soil is taken into zccount. Oxalate-extractable P, (Pox), appears to be a major part of the total soil P. The total P sorption measured, F, was predominantly related to the amounts of amorphous iron (Feox) and aluminium (Alox). A significant relation between crystalline iron (Fed– Feox) and total P sorption was not found. Reversibly adsorbed phosphate (Pi), measured after 40 d reaction time, was a function of clay content and content of amorphous iron and aluminium (hydr)oxides.
A Pentacene with a 144° Twist

9,10,11,20,21,22-Hexaphenyltetrabenzo[a,c,l,n]pentacene (1) was prepared by the reaction of 1,3-diphenylphenanthro[9,10-c]furan with the bisaryne equivalent generated from 1,2,4,5-tetrabromo-3,6-diphenylbenzene in the presence of n-butyllithium, followed by deoxygenation of the double adduct with low-valent titanium. The X-ray structure of 1 shows it to be the most highly twisted polycyclic aromatic hydrocarbon known, with an end-to-end twist of 143.6°. Compound 1 was resolved by chromatography on a chiral support, and the pure enantiomers have specific rotations in excess of 7000°, but the molecule racemizes slowly at 25 °C (t1/2 = 9.3 h, ΔG⧧rac = 23.8 kcal/mol).
Electron-beam-induced current study of grain boundaries in multicrystalline Si

Systematical studies on the intrinsic and extrinsic recombination activities of grain boundaries (GBs) in multicrystalline silicon (mc-Si) were reported by using temperature-dependent electron-beam-induced current (EBIC). EBIC results revealed that in the clean mc-Si, all the GBs exhibited weak EBIC contrasts at 300 K, suggesting their recombination strengths were weak and the energy levels were associated with shallow levels. The effect of impurity contamination was also evaluated by employing different contamination levels of Fe. The EBIC contrasts of GBs were enhanced after Fe contamination and showed a strong dependence on both the GB character and contamination level. The impurity gettering abilities of GBs were as following, SA > R > high-Σ > low-Σ. SA GBs were found with the strongest impurity gettering ability and tended to be the most detrimental GBs. Finally, the effect of H-passivation on different GBs with or without contamination was evaluated. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Isolation and Identification of Volatile Compounds from a Wine Using Solid Phase Extraction, Gas Chromatography, and Gas Chromatography/Mass Spectrometry

Recovery efficiencies of main volatile components of wine from porous polymer Porapak Q were investigated using dichloromethane, ethyl ether, and pentane as solvents. The nine wine components used for recovery tests were 2-methyl-1-propanol, 3-methyl-1-butanol, 2-phenylethanol, ethyl hexanoate, ethyl octanoate, diethyl butanedioate, hexanoic acid, octanoic acid, and decanoic acid. Dichloromethane showed the highest recovery efficiency, followed by ethyl ether and pentane. Nearly 80% recovery for ethyl hexanoate and ethyl octanoate was obtained by dichloromethane for a concentration of 10 ppm. Over 96% recovery was obtained by dichloromethane for 2-phenylethanol, diethyl butanedioate, hexanoic acid, and octanoic acid for 10 ppm. Volatile components from a commercial wine were trapped on Porapak Q and subsequently recovered using an organic solvent. The major compounds identified in the three extracts were 3-methyl-1-butanol, 2-phenylethanol, octanoic acid, monoethyl butanedioate, and hexanoic acid. Keyword.
Growth of CdS Nanorod-Coated TiO2 Nanowires on Conductive Glass for Photovoltaic Applications

Synthesis of TiO2 nanowires directly on conductive and transparent glass substrates would be very useful for various applications such as photovoltaics and photocatalysis. Here, we report for the first time that single-crystalline TiO2 nanowires can be synthesized on fluorine-doped tin oxide (SnO2:F)-coated soda-lime glass substrates by chemical vapor deposition (CVD) at a temperature that is below the glass softening temperature (<530 °C). Moreover, we demonstrate that CdS nanorods with high crystallinity can be grown on top of the TiO2 nanowire surface via chemical vapor transport (CVT) at 500 °C. Resulting TiO2@CdS heterostructure that has type-II band alignment showed increased absorption over the wavelength range of visible light. The TiO2@CdS-based inorganic-dye sensitized solar cells (DSSC) were fabricated by filling liquid electrolytes and their cell operation was demonstrated with conversion efficiency.
Separation between fast and slow polarizations in continuum solvation models

Nonequilibrium solvation is important to describe many chemical processes in solution such as, for example, reactions involving light atoms or solvatochromic effects on UV spectra. This paper reports on an effective and general procedure to perform nonequilibrium calculations using continuum solvent models. First, “fast” dielectric constants are defined for the different processes which take place in solution (depending on their characteristic times), second, such constants are used in a new approach to separate fast and slow solvation components, and finally this approach is inserted in the framework of apparent surface charge (ASC) models. This procedure is applied to some test cases, involving very fast solute transitions which require the treatment of nonequilibrium effects.
Temperature dependences of energies and broadening parameters of the band-edge excitons of Re-doped WS2 and 2H-WS2 single crystals

The temperature dependences of the spectral features in the vicinity of direct band-edge excitonic transitions for rhenium-doped (Re-doped) and undoped WS2 single crystals are measured over a temperature range of 15–300 K using piezoreflectance (PzR). From a detailed line shape fit of the PzR spectra, the temperature dependences of the energies and broadening parameters of the A and B excitons are determined accurately. The A and B excitonic transition energies show a red shift and a reduction of their splitting due to the presence of a small amount of Re and the broadening parameter of the excitonic transition features increases due to impurity scattering. The broader line width and the nature of the two-dimensional Mott–Wannier excitons of the 3R polytype prevent the detection of higher Rydberg series for the Re-doped samples. The parameters that describe the temperature variations of the energies and broadening functions of the excitonic transitions are evaluated and discussed.
Scaling-up a Confined Jet Reactor for the Continuous Hydrothermal Manufacture of Nanomaterials

A confined jet reactor (mixer) is presented as a novel solution for the scalable continuous hydrothermal flow synthesis (CHFS) of nanoceramics. In CHFS, nanoceramics are formed upon mixing of two streams consisting of an aqueous metal salt solution at room temperature with a flow of less dense supercritical water (at 240 bar and 450 °C). Upon mixing, hydrolysis and dehydration occurs, resulting in the particles being formed in a continuous manner. The confined jet mixer used herein overcomes previous designs of mixers that can accumulate material internally and block. A method for scaling up the jet mixer (reactor) is described, to determine the size of jet mixer (internal mixer diameter 13.5 mm) prior to its use in a newly commissioned pilot plant designed to process flow rates 40 times greater than the equivalent laboratory-scale process (internal mixer diameter 4.6 mm). It was confirmed that the pilot plant scale mixer allowed safe and continuous operation with no blockages at much higher concentration.
Biodegradation Potential of Halo(alkali)philic Prokaryotes

Oil and gas exploitation and downstream processing may generate large volumes of contaminated aqueous wastewaters. Without treatment, the discharge of these streams into the environment would lead to considerable environmental problems. A combination of physicochemical and biological treatment processes are applied to treat such polluted streams (e.g., in conventional water purification plants). However, the application of microorganisms in these streams is rather limited streams to salt levels well below those of seawater. The potential of microorganisms to degrade various organic and inorganic pollutants at higher salinities was surveyed in the open literature. The advantage of biological treatment processes that operate at elevated salinities is that no dilution water is needed, which is particularly relevant for arid regions. The available literature is scarce, especially concerning truly halophilic bacteria that thrive at salt concentrations significantly higher than in seawater. The obvious trend of most of the publications indicates a significant inhibition of the biodegradation activity at salt concentrations above 10 wt. %. However, a specialized group of extremophilic microorganisms, called halo(alkali)philes, could replace freshwater or marine organisms in the biodegradation processes at salinities above 1.5 M and pH values above 9. They are present in natural hypersaline habitats and can be activated either directly in situ by addition of micronutrients and aeration, or introduced into engineered water treatment systems. In a number of studies, the possibility of microbial HC degradation up to 5 M NaCl has been mentioned. Relatively little is known about the removal of toxic inorganic compounds, such as H2S, CO, and CN−, at halo(alkaline) conditions. These compounds are clearly associated with the processing of oil, coal, and gas. An exception is the application of sulfur-cycling bacteria, as these organisms have been intensively studied during the last decade. Sulfur-oxidizing and sulfidogenic bacteria can function efficiently at extremely saline and alkaline conditions. The general conclusion from this survey is that many biodegradation routs are, in principal, possible at high salt/pH but more research is needed to make a real progress in the development of engineered processes that can be applied to protect the environment.
Optical and thermal spectroscopic studies of luminescent dye doped poly(methyl methacrylate) as solar concentrator

A luminescent solar concentrator was prepared that was based on a bulk sheet of poly(methyl methacrylate) doped with different luminescent dyes (K1, K27, and Lpero) during the polymerization process. Photo- and thermal-stability studies revealed that the Lpero dye system is the most stable one. The electronic transition mechanism for the concentrator systems was obtained by the darktrap and phototrap spectroscopy technique. The results were correlated with the outdoor test measurements over 1 year. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 3316–3323, 1999
Remediation of arsenic contaminated soil using soil washing with an acidic and reducing solution

Soil contamination with arsenic (As) is a serious environmental concern due to its highly toxicity and carcinogenic property. Iron oxides are known to be the most important factor for controlling As concentration in soil pore water. They adsorb large amount of As and coprecipitate with As. We tried to develop a new washing method of As contaminated soil by the dissolution of iron oxide and desorption of As employing pH and redox potential adjustment. An As contaminated soil sample was collected at a rice paddy field near a copper smelter, Korea. The As concentration of the soil sample was determined with an aqua-regia extraction method. Washing solutions were prepared to be 0.001– 0.1N HCl and 0–3% Na-dithionite. The soil and washing solution were mixed at 1:4 ratio and the mixtures were reacted for 15, 30, 45 and 60 minutes. After the reaction, the soil and washing solution were separated with a centrifugation. The pH, Eh and concentrations of As, Fe and Mn of the washing solution were determined and the As concentration of the washed soil sample was also determined. The separated washing solution was treated with H2O2, CaCl2·2H2O and cationic organic polymer to remove As. The soil washing with the 0.01N HCl_3% Na-dithionite solution for 30 minutes was the most effective in the As removal from the soil reducing As concentration from 43 mg/kg to 18 mg/kg. The As concentration of the washing solution was reduce from 19.2 mg/L to 0.76 mg/L after the waste water treatment.
Adhesion on Nanoorganized Multilayers: Surface Thermodynamics and Local Energy Dissipation

Nanostructured multilayers, composed of alternate organic (3-mercaptopropyltrimethoxysilane, alkylthiols, polydimethylsiloxane) and metallic (gold) layers, are grafted onto glass and prepared in order to modify the mechanical and dissipative properties of a thin surface layer of the substrate. The external face is constituted either of gold or alkyl groups, allowing us to study two types of surfaces exhibiting different chemical and thermodynamic properties. The formation and the structure of the nanostructured multilayers are first examined by means of various techniques such as atomic force microscopy (AFM), wettability, X-ray photoelectron spectroscopy (XPS), and conductivity measurements. All the results concerning the structure of the systems studied are used to understand the adhesive properties at short contact times (tack) of the multi-layers and an elastomer (polyisoprene). The influence of the structural aspects of gold layers, the length of the alkyl chains of the top layer, the terminal functionality, and the length of the confined organic layer between two gold layers on the energy of adhesion regarding the polyisoprene are clearly demonstrated. The influence of the nano-structured surface layers on adhesion phenomena is explained in terms of either the surface thermodynamics or local energy dissipation during the propagation of a fracture according to complex mechanisms.