Miracle-dz/UniFAR-FTUs huggingface dataset:
Flashback Limits for Combustion Induced Vortex Breakdown in a Swirl Burner

Flame flashback from the combustion chamber into the mixing zone limits the reliability of swirl stabilized lean premixed combustion in gas turbines. In a former study, the combustion induced vortex breakdown (CIVB) has been identified as a prevailing flashback mechanism of swirl burners. The present study has been performed to determine the flash-back limits of a swirl burner with cylindrical premixing tube without centerbody at atmospheric conditions. The flashback limits, herein defined as the upstream flame propagation through the entire mixing tube, have been detected by a special optical flame sensor with a high temporal resolution. In order to study the effect of the relevant parameters on the flashback limits, the burning velocity of the fuel has been varied using four different natural gas-hydrogen-mixtures with a volume fraction of up to 60% hydrogen. A simple approach for the calculation of the laminar flame speeds of these mixtures is proposed which is used in the next step to correlate the experimental results. In the study, the preheat temperature of the fuel mixture was varied from 100 °C to 450 °C in order to investigate influence of the burning velocity as well as the density ratio over the flame front. Moreover, the mass flow rate has been modified in a wide range as an additional parameter of technical importance. It was found that the quenching of the chemical reaction is the governing factor for the flashback limit. A Peclet number model was successfully applied to correlate the flashback limits as a function of the mixing tube diameter, the flow rate and the laminar burning velocity. Using this model, a quench factor can be determined for the burner, which is a criterion for the flashback resistance of the swirler and which allows to calculate the flashback limit for all operating conditions on the basis of a limited number of flashback tests. © 2002 ASME
Role of Steric Hindrance in the Performance of Superplasticizers for Concrete

Interparticle potential energy calculations were performed to investigate the mechanisms by which a new class of concrete admixtures, generally referenced as poly(carboxylic acid)-type (PC) superplasticizers, which aid in dispersing cement particles, are formed. These calculations consisted of long-range Van der Waals, electrostatic, and steric interactions. The repulsive potential that resulted from electrostatic interactions was negligible, which would allow cement particles to flocculate in the absence of steric contributions. A model was developed to describe the adsorption behavior of these superplasticizers, which consisted of grafted polyethylene oxide (PEO) chains on a PC backbone on cement surfaces. Using this adsorption model, the influence of the length of the PEO molecular chain and the density per unit area on the steric contribution was quantified. Steric hindrance effects were the dominant stabilizing mechanism in this system. As expected, enhanced stability was observed with increasing adlayer thickness (and/or density). The results of this study may be useful in designing the molecular structure of this new and important class of dispersion aids for cement-based systems.
Application of the effective vibration-rotation hamiltonian to H2 and D2

The effective vibration-rotation hamiltonian developed by Bunker and Moss in the preceding paper is applied to H2 and D2. We have fitted this hamiltonian to the experimental vibration-rotation energy levels of the ground electronic state of D2 by adjusting the parameters μv and μr. In doing this we found that we could achieve a satisfactory fit (standard deviation < 0·1 cm-1) by adjusting only the one parameter μv and fixing μr as equal to the nuclear reduced mass μ. Using the isotopic dependence of μv given by Bunker and Moss we have used μv (D2) to calculate μr (H2) and have used that value of μv, with μr = μ, to predict the vibration-rotation energy levels of H2 in its ground electronic state. More consistent experimental values for these energies than presently available are being determined in experiments under way in this laboratory, and they will test these predictions.
CONVECTIVE BOILING IN PARALLEL MICROCHANNELS

Experiments were performed with clear water and with surfactant flowing in parallel triangular microchannels. The study is based on systematic measurements of temperature and flow pattern by infrared radiometry and high-speed digital video imaging. Different flow patterns were observed simultaneously in various microchannels at a fixed value of water or surfactant flow rates. Depending on flow and heat flux, pressure and temperature instabilities in the heated microchannels were studied. This work develops a practical modeling approach for two-phase microchannel heat sinks and also considers effect of surfactant on convective boiling in microchannels.
GC-IRMS in the authenticity control of the essential oil of Coriandrum sativum L.

The essential oils of 10 authentic coriander samples of different origin were analyzed. Capillary gas chromatography, on-line coupled with isotope ratio mass spectrometry (cGC-IRMS) using Stabilwax as the stationary phase, was applied. Alternatively, heptakis(2,3-di-O-methyl-6-O-tert-butyldimethylsilyl)-β-cyclodextrin in PS 268 was used as the chiral stationary phase. The enantiomeric ratio and the δ 13 C PDB values of some characteristic compounds were compared with those of commercially available spices and essential oils. The influence of isotopic effects on the 6 values during the primary CO 2 fixation was eliminated by definition of a suitable internal isotopic standard (i-IST). The isotopic effects among genuine monoterpenes are, therefore, exclusively determined by the influence of enzymatic reactions during secondary biogenetic pathways.
A theoretical investigation of stimulated Brillouin scattering in phase-modulated fiber amplifiers

We report on theoretical and numerical investigations of stimulated Brillouin scattering (SBS) in optical fibers. A theoretical framework is presented which involves a nonlinear triply-coupled time-dependent system of equations containing the optical, Stokes, and phonon fields. We examine short fibers where previous approximations for long fibers cannot be made. We consider modulation frequencies and linewidths starting at approximately the Brillouin gain bandwidth and all the way up to frequencies of the order of the Brillouin resonance frequency. We provide simulations showing the SBS suppression factor as a function of modulation amplitude and frequency for a single-sinusoidal modulator.
Reference Correlation of the Viscosity of Propane

A new representation of the viscosity of propane includes a zero-density correlation and an initial-density dependence correlation based on the kinetic theory of dilute gases and on the Rainwater–Friend theory. The higher density contributions of the residual viscosity in the representation are formed by a combination of double polynomials in density and reciprocal temperature, and a free-volume term with a temperature-dependent close-packed density. The full surface correlation is based on a set of primary experimental data selected as a result of a critical assessment of the available information from 37 original viscosity studies. The review refers to 96 citations altogether. The validity of the representation extends from the triple point to 600 K and 100 MPa in accordance with the modified Benedict–Webb–Rubin equation of state. The uncertainty of the representation varies from ±0.4% for the viscosity of the dilute gas phase between room temperature and 600 K, to about ±2.5% for the range 100–475 K up.
Viscoelastic surfactant solutions: model systems for rheological research

The molecular constitution of viscoelastic gels is customarily described in terms of networks, which may have a transient or permanent character. Such supermolecular structures are often observed in biological or macromolecular systems, but can even occur in dilute solutions of some detergents. Surfactant molecules in solution, under suitable conditions, assemble reversibly into large aggregates of rod-like geometry. Depending on the ionic strength of the solution, these particles may be completely stiff or semiflexible. At low concentrations, when the lengths of the rods are much smaller than their mean distance of separation, there exists a sol state which is highly sensitive to shear forces. At higher surfactant concentrations, where the lengths of the rod shaped micelles become comparable to their mean distance, one observes gel formation and the solutions exhibit pronounced elastic properties. In analogy to polymer systems, these elongated, rod shaped micelles are strongly entangled; this leads to co.
Existence of path-dependence in the LiFePO4 electrode

This paper explores two unique features of the lithium iron phosphate (LiFePO 4 ) electrode that provide insight into the electrochemical behavior of this system. First, we show the existence of an asymmetric behavior between charge and discharge, whereby the utilization on charge is considerably larger than that on discharge under current densities where transport limitations are important. Second, we show the existence of a path-dependence in this system whereby the high-rate electrochemical behavior of the electrode at a particular state of charge (SOC) depends on the path by which the electrode was brought to that SOC. We qualitatively explain both these features using a shrinking-core model to account for the juxtaposition of the two phases. The path-dependence reported in this paper could have implications in batteries used in hybrid-electric-vehicles as the power capability of this chemistry will depend on its cycling history, thereby complicating predictions of power. In addition, the data reported here emphasizes the importance of ensuring consistency in defining the SOC in experiments on this electrode.
Synthesis and Properties of CdSe/ZnS Core/Shell Nanorods

A method for the synthesis of CdSe/ZnS core/shell nanorods is reported. In the first step rods are grown, and in a second step a shell of ZnS is overgrown at moderate temperatures in a mixture of trioctylphosphine-oxide and hexadecylamine. Structural and chemical characterization using transmission electron microscopy, X-ray diffraction, and energy dispersive X-ray spectroscopy were performed providing direct evidence for shell growth. The emission quantum yield significantly increases by over 1 order of magnitude for the core/shell nanorods compared to the original rods because of the improved surface passivation. Rods with lengths up to ∼30 nm were investigated, and in this size regime the maximal achievable QY showed little dependence on length and strong dependence on rod diameter, with increased QY in smaller diameters. Color tunability is available via tuning of the rod diameter. The stability against photooxidation was significantly improved in core/shell nanorods compared with rods coated by organ.
CALCULATION OF EFFECTIVE GAS FLUX FROM SOIL FOLLOWING BAND APPLICATION OF MANURE OR FERTILIZER

Greenhouse gases are emitted following application of manure and nitrogen-containing fertilizers to soil. Manure and fertilizers are often applied in subsurface bands in the soil, or in bands on the soil surface. This article presents a method that has been developed for calculating the effective gas flux for a multiple-band area to which manure or fertilizer has been applied in bands. The method has been developed for circular and rectangular flux chambers. In analyzing the method, a combination of CO2 gas fluxes from a field experiment that gave a relatively low whole-plot effective flux and a combination that gave a relatively high whole-plot effective flux were used. For the lower-end flux situation, when the dimension of the flux chamber in the direction perpendicular to the band is considerably less than the band spacing, if the flux in a chamber that is centered on a band is assumed to be the whole-plot effective flux, then this assumption would overestimate the actual whole-plot effective flux by a considerable amount. The error of this type of assumption is reduced for the higher-end flux situation, regardless of flux chamber dimensions, and is reduced when the lower-end flux situation occurs and the dimension of the flux chamber in the direction perpendicular to the band is intermediate to nearly as large as the band spacing. The method in useful in calculating effective gas fluxes for whole plots to which manure or fertilizer has been band-applied.
Observation of Extra-High Depolarized Light Scattering Spectra from Gold Nanorods

We report on depolarized light scattering spectra from suspensions of gold nanorods in terms of the depolarized ratio Ivh/Ivv measured from 400 to 900 nm. For separated, highly monodisperse and highly monomorphic samples, we observed spectra with an unprecedented depolarization ratio with a resonance maximum of about 50% at wavelengths of 600−650 nm, below the long-wavelength 780 nm extinction peak. These unusual depolarization ratios are between 1/3 and 3/4 theoretical limits established for small dielectric and plasmon-resonant needles, respectively. Our measurements showed a strong correlation between the resonance depolarization ratio and the ratio of the long-wavelength to short-wavelength extinction resonances. Specifically, for standard seed-mediated-growth nanorods with a round-end-cylinder or a “dog-bone” shape morphology, the peak-extinction ratios were less than 3 and the resonance depolarization ratio was about 30−35%. The measured extinction and depolarization spectra are in excellent agreeme.
Biodegradable pyridinium ionic liquids: design, synthesis and evaluation

A range of ionic liquids (ILs) with a pyridinium cation were synthesised and their biodegradability was evaluated using the CO2 Headspace test (ISO 14593). ILs bearing an ester side chain moiety were prepared from either pyridine or nicotinic acid and showed high levels of biodegradation under aerobic conditions and can be classified as ‘readily biodegradable’. In contrast, pyridinium ILs with alkyl side chains showed significantly lower levels of biodegradability in the same test. The utility of the biodegradable IL 6c as a reaction solvent for the Diels–Alder reaction was also investigated.
Collective diffusion, nucleation, and spinodal decomposition in polymer mixtures

The dynamics of concentration fluctuations in binary polymer mixtures AB, A and B being long and flexible chains, is studied near the critical point of unmixing. A ‘‘hydrodynamic’’ theory in close analogy to the treatments of Cahn–Hilliard and Cook for the dynamics of unmixing alloys is developed, and its validity is carefully analyzed. It is shown that homogeneous nucleation for long chains is negligible except in a narrow region of volume fraction φ0 near the spinodal curve φs0 of width (φs0−φ0)/φ0∝N−1, where N is the number of subunits of the chains. For N→∞ the spinodal curve hence is well defined, in contrast to mixtures with short‐range forces, and also the linearized theory of spinodal decomposition is predicted to have wider validity. The collective relaxation in the one‐phase region is described by a characteristic time involving the collective diffusion constant Dcoll τq=(Dcoll q2)−1, if the wave vector q is smaller than the inverse correlation length ξ−1coll, while in the range ξ−1coll≪q≪R−1 (R.
Translocation of polyarginines and conjugated nanoparticles across asymmetric membranes

Understanding how cell-penetrating peptides translocate across cell membranes is of great importance in biomedicine. In this paper, we study the interactions between polyarginines and asymmetric membranes by using coarse-grained molecular dynamics simulations. It is found that a peptide has the probability to penetrate through the membrane because of the transmembrane potential difference; however, it is difficult for a single peptide to spontaneously penetrate through the membrane while multiple peptides can translocate across membranes by pore-mediated processes. Further, we also provide insights into the transporting ability of polyarginines, and find that the peptide can transport hydrophobic as well as hydrophilic particles through membranes, where the translocation of a hydrophobic particle is easier than that of a hydrophilic one. The present study can help to better understand the interactions of the peptides with cell membranes and may give some new suggestions on the design of future nanomaterials for drug delivery.
InP Quantum Dot - Organosilicon Nanocomposites

Nanomechanical Systems Research Division, Korea Institute of Machinery and Materials, Daejeon 305-343, Korea Received October 22, 2011, Accepted February 1, 2012InP quantum dot (QD)-organosilicon nanocomposites were synthesized and their photoluminescencequenching was mainly investigated because of their applicability to white LEDs (light emitting diodes). Theas-synthesized InP QDs are capped with myristic acid (MA), which are incompatible with typical siliconeencapsulants. We have introduced a new ligand, 3-aminopropyldimethylsilane (APDMS), which enablesembedding the QDs into vinyl-functionalized silicones through direct chemical bonding. The exchange ofligand from MA to APDMS does not significantly affect the UV absorbance of the InP QDs, but quenches thePL to about 10% of its original value with the relative increase in surface related emission intensities, which isexplained by stronger coordination of the APDMS ligands to the surface indium atoms. InP QD-organosiliconnanocomposites were synthesized by connecting the QDs using a short cross-linker such as 1,4-divinyl-tetramethylsilylethane (DVMSE) by the hydrosilylation reaction. The formation and changes in the opticalproperties of the InP QD-organosilicon nanocomposite were monitored by ultraviolet visible (UV-vis)absorbance and steady state photoluminescence (PL) spectroscopies. As the hydrosilylation reaction proceeds,the QD-organosilicon nanocomposite is formed and grows in size, causing an increase in the UV-visabsorbance due to the scattering effect. At the same time, the PL spectrum is red-shifted and, very interestingly,the PL is quenched gradually. Three PL quenching mechanisms are regarded as strong candidates for the PLquenching of the QD nanocomposites, namely the scattering effect, Forster resonance energy transfer (FRET)and cross-linker tension preventing the QD’s surface relaxation. Key Words : InP quantum dot, Organosilicon, Nanocomposite, PL quenching, Ligand exchangeIntroductionA semiconductor quantum dot (QD) is a nano-sized,crystalline particle consisting of hundreds to thousands ofatoms, falling in the gap between molecular cluster and bulkcrystal.
Atomic layer deposition of molybdenum oxide using bis(tert-butylimido)bis(dimethylamido) molybdenum

Molybdenum trioxide films have been deposited using thermal atomic layer deposition techniques with bis(tert-butylimido)bis(dimethylamido)molybdenum. Films were deposited at temperatures from 100 to 300 °C using ozone as the oxidant for the process. The Mo precursor was evaluated for thermal stability and volatility using thermogravimetric analysis and static vapor pressure measurements. Film properties were evaluated with ellipsometry, x-ray photoelectron spectroscopy, secondary ion mass spectroscopy, and secondary electron microscopy. The growth rate per cycle was determined to extend from 0.3 to 2.4 A/cycle with <4% nonuniformity (1-sigma) with-in-wafer across a 150 mm wafer for the investigated temperature range.
AN AB INITIO STUDY OF HYDROTREATING OF THIIRENE AND THIIRANE ON

Thiirene and thiirane have been chosen as model molecules representative of products present in crude oil to study the key steps in hydrotreating. The hydrotreating which can be desulfurization, deoxygenation or denitrogenation is the treatment of oil crude products under hydrogen pressure in presence of catalysts. This process leads to hydrogenolysis of carbon- heteroatom bond accompanied by heteroatom elimination. The catalytic site used is based on molybdenum disulfide (MoS 2), which is considered as active phase in the commercial catalysts containing molybdenum atoms. Two steps characterise the desulfurization process: the adsorption and the carbon-sulfur bond cleavage. The thiirene geometry has been destroyed through the cleavage of one of the carbon-sulfur bonds. The calculation results showed that the desulfurization of the thiirene and thiirane do follow a heterolytic process. At the end of process, the reaction pathways are the same with an activation energy which was higher for thiirane than for thiirene. These results confirmed the same catalytic site and molecules obtained in previous works in the EHT method.
Ionic liquids in the assay of proteins

As a group of novel green solvents, ionic liquids have attracted extensive attention and gained popularity in various applications including protein assays. Ionic liquids are not only an excellent reaction medium to replace the conventional organic solvents, but are also an efficient participant to achieve better performances. The aim of the present mini-review is to illustrate the state-of-the-art progress of implementing ionic liquids in protein assays, focusing on the investigations of protein stability/activity, protein extraction and isolation/purification, protein crystallization, separation of protein species and their detections.
The Infrared Spectra of NF3 and PF3

The infrared spectra of NF3 and PF3 have been investigated with a prism instrument in the range 250 cm−1 to 5000 cm−1. The fundamental frequencies are for NF3, ν1(A1)=1032 cm−1, ν2(A1)=647 cm−1, ν3(E)=905 cm−1, and ν4(E)=493 cm−1; and for PF3, ν1(A1)=892 cm−1, ν2(A1)=487 cm−1, ν3(E)=860 cm−1, and ν4(E)=344 cm−1. Force constants as well as thermodynamic functions are calculated for both molecules.
Demonstration of AlGaN/GaN High-Electron-Mobility Transistors on 100-mm-Diameter Si(111) by Ammonia Molecular Beam Epitaxy

We demonstrate, for the first time, crack-free AlGaN/GaN high-electron-mobility transistors (HEMT) on 100 mm Si(111) by ammonia molecular beam epitaxy. High growth rate accelerates rapid transition from three-dimensional (3D) to two-dimensional (2D) growth and reduces the defect density. With increasing GaN buffer thickness, FWHM of GaN(002) XRD peak and dislocation density decrease. Highest electron mobilities of 1350 and 4290 cm2/V·s were measured at RT and 90 K, respectively. Submicron gate devices exhibited good pinch-off characteristics with a maximum drain current (IDmax) of 768 mA/mm at Vg= +1 V and a maximum extrinsic transconductance (gmmax) of 190 mS/mm at VD= 6 V.
Edge Traction Stereo Matching Method Using RBF

For obtaining the precise and dense disparity map, a stereo matching method with occlusion detection using edge traction was presented, which is integrated with the area similarity and edge feature points in radial basis function (RBF). Obtain the edge feature points by using LoG and their label sets of disparity to dividing the image region into feature and featureless sets. Area similarity, feature points and disparity smoothness are incorporated into error function of RBF. Relative reliable disparities of feature points restrict the disparity estimation of featureless points and decrease the possibility of forming mismatching illusion. Hierarchical Gaussians approach is imposed in this matching framework. Besides, we test the match values and the match conflict at sight lines to determine the occlusion area and avoid mismatching illusion. According the uniqueness constraint, whole high-density disparity map was obtained