Miracle-dz/UniFAR-FTUs huggingface dataset:
Energy Transfer between Low Current Discharge and Insulation Surfaces

With the development of electricity transmission systems, more and more insulators have been used in the system to isolate the high potential conductors from the earth. In order to secure the reliability of power system, it is necessary to understand the ageing mechanism of the insulators. A model for energy (heat) transfer between low current discharges and insulation surfaces has been built in this project which contributes to the understanding and prediction of insulator ageing.Within the experimental work, the temperature of low current discharges under different conditions has been measured with the ? Best-fit? method. The temperature was found to vary between 1200 K and 2300 K with current level, sub cycle duration, gap length, electrode conductivity and polarity of DC discharges. The discharge temperature increases with the growth of current and sub cycle duration by means of the elevation of energy, while the discharge temperature is hotter between salt water droplets than between tap water droplets even though the former has a lower energy (I^2 Rt). The temperature is insensitive to a change of gap length and a positive discharge has a higher temperature than an equivalent negative one. The specific measurement shows the middle part is hotter than the electrode areas.Within the simulation work, the presence of water droplet(s) on the insulation surface concentrates and enhances the electric field over the surface which increases the risk of partial discharge. For practical insulators, this means the core, rather than the sheds, suffers more from discharges between water droplets as they are aligned to the electric field. This highlights the importance of keeping the core dry.The simulation of heat transfer between low current discharges insulation surface was achieved using COMSOL software. The simulated results show that the surface temperature increases rapidly in the first few seconds and arrives at a thermal equilibrium state after 20 seconds of discharge, which meets the experimental observation. The insulation surface temperature distribution under AC discharge is symmetric and the surface centre has the highest temperature which decreases towards the water droplets. In DC, the surface around the cathode is the hottest and the anode area is the coldest.
International Journal of Food Engineering Effect of Guar Gum on Dough Stickiness and Staling in Chapatti – An Indian Unleavened Flat Bread

Chapatti, Indian unleavened flat bread made of whole-wheat flour, is traditionally prepared in households by hand sheeting of dough followed by baking on hot griddle and is consumed fresh. Investigations were made to study the effect of guar gum on whole wheat chapatti dough stickiness and its effect on staling of chapatti during storage. Guar gum was incorporated at various levels ranging between 0.25-1.0% w/w of whole wheat flour. Chapatti dough was prepared and evaluated for dough stickiness using Chen-Hoseney dough stickiness probe. Chapattis were prepared and monitored for staling parameters such as water soluble starch (WSS), moisture content, in vitro enzyme digestibility (IVED), extensibility and tear force, both when fresh and after storage for three days at room temperature (30±2 °C) and refrigerated temperature (4±1 °C). From the study it was observed that guar gum prevented staling in chapattis as was monitored through various parameters. Moisture, WSS, IVED content in guar gum incorporated chapatti was higher than the control chapatti. The force required to tear fresh chapattis was decreased with hydrocolloid addition however guar gum addition at 0.75% w/w of whole wheat flour gave the softest chapatti. Extensibility of stored chapatti was significantly decreased with storage, both at room and refrigeration temperature. However, refrigerated chapatti containing guar gum showed less loss in extensibility, up to a period of three days.
A Novel Biomass-based Polymer Prepared from Lignin-derived Stable Metabolic Intermediate by Copper(I)-catalyzed Azide-Alkyne Click Reaction

The Cu I -catalyzed, but ligand-free azide-alkyne cycloaddition reaction was applied to the polymerization of the newly synthesized diethynyl-functionalized 2-pyrone monomer originally isolated from lignin via metabolic pathway. The polymerization was monitored by GPC and IR spectra and the resulting high molecular weight polymer was unambiguously characterized by 1 H NMR, thermal analysis, and optical absorption and emission spectra.
Gate oxide reliability projection to the sub-2 nm regime

The important components of reliability projection are investigated. Acceleration parameters are obtained for a 1.6 nm oxide with a soft breakdown criterion. Based on the physical percolation model, the voltage scaling factor for time to breakdown is found to increase with lower voltage, explaining the experimental observation of 6.7 ± 0.4 dec V-1 for the 1.6 nm oxide. The distribution of breakdown times is shown to be sensitive to thickness variation across the test wafer, and a Weibull slope of 1.38 ± 0.1 was obtained. The temperature dependence of the time to breakdown was found to be non-Arrhenius and to have a slope of 0.02 dec °C-1. Using these parameters, the 1.6 nm oxide was found to have a 10 year lifetime with a 100 ppm failure rate for 1.3 V operation at 100 °C. Our understanding of soft breakdown is described as well as an investigation of device operation after soft breakdown, which may further improve the reliability projection.
Comparing the Basic Phenomena Involved in Three Methods of Pore‐size Characterization: Gas Adsorption, Liquid Intrusion and Thermoporometry

Gas adsorption at 77 K is probably the most widely used method to characterize mesoporous adsorbents via capillary condensation. Mercury intrusion is also commonly used for the characterization of such materials with the possibility to extend the pore width distribution measurement to the macropore range. More recently water intrusion was proposed to study hydrophobic porous solids. Thermoporometry is a further characterization method, now based on the study of the solid/liquid transition. We can consider that all these methods rely on the modification of the phase diagram of a pure substance under the effect of confinement. For each of them, the equations and models derived are based either on classical thermodynamics or on statistical approaches. In most cases, the derivation of the pore width distribution is carried out with the assumption that the porous system is made up of non‐connected cylinders, whereas the actual complexity of the structure is derived from the hysteresis shape. Our aim here is to compare the four approaches above (gas adsorption, mercury intrusion, water intrusion, thermoporometry) on samples giving rise, in their gas adsorption isotherms, to the typical hysteresis loops of the IUPAC classification. Our comparison is in great part carried out after the shape of the hysteresis loops obtained with the various methods and after the information it brings on the mechanism of replacement of a phase by the other within the porous system.
Infrared and Raman spectra of two well–barrier–well 1,2‐di(α,α′‐oligothienyl)ethanes

The vibrational Fourier transform infrared and Fourier transform Raman spectra of two neutral thiophene-based oligomers in solution and in the solid state were studied. The compounds have a well–barrier–well structure, where the well parts are two biothiophene or terthiophene end moieties and the barrier part is a dimethylene fragment with a larger energy gap. Characteristic features are correlated with vibrational data on one-dimensional unsubstituted α-oligothiophenes and α,α′-dimethyl end-capped oligothiophenes. Vibrational assignments are also proposed for relevant bands in the whole spectral range. © 1997 John Wiley & Sons, Ltd.
Laser photolysis formation of gold colloids in block copolymer micelles.

The laser photolysis of gold AuIII salts embedded in micelle cores of block copolymer micelles derived from polystyrene−poly-4-vinylpyridine was studied. Two types of polystyrene−poly-4-vinylpyridines having different block length have been employed, producing micelles with different properties. The influence of the type of gold salt, loading rate, presence of water, micelle characteristics, and some other parameters on the rate of reduction and gold colloid formation were investigated. The presence of water in the system containing HAuCl4·3H2O was found to accelerate the AuIII reduction, while the gold colloid size was not affected (about 3 nm). The substitution of HAuCl4·3H2O with AuCl3 results in much slower accumulation of AuI species with subsequent slower nucleation of gold colloids that results in bigger particles with mean diameter of 6.0 nm. Increasing the amount of metal compound was found to lead to an increase of the particle size.
Highly hydrophobic and adhesive performance of graphene films

Graphene films with high hydrophobic and adhesive performance were fabricated via two simple steps: chemical exfoliation of natural flake graphite following redox, and film formation by suction filtration without any chemical modification. Irregularly stacked multilayer graphene nanosheets comprised the microstructure, whereas folding and agglomeration of graphene nanoflakes with few layers comprised the nanostructure. The films also showed remarkable surface wettability and reversible transition from hydrophobicity to hydrophilicity via periodic alternation of ultraviolet irradiation and air storage. Based on Wenzel's theory and adsorption dynamics, an optimum mechanism is proposed for the surface wettability behavior. On the one hand, the film microstructure and nanostructure enhance the graphene surface hydrophobicity. On the other hand, the capillary force is maximized by the nanostructure such that water fills the grooves of the rough solid surface. This result is a strong interaction between water and the film surface giving highly adhesive property to the films. The highly hydrophobic and adhesive performance of the graphene films could be useful in the device and biomaterials application.
pH‐dependent surface‐enhanced Raman scattering observation of sulfanilamide on the silver surface

Monolayers of sulfanilamide on metallic surface can serve as an ideal model for understanding the interaction mechanism between the metal and the sulfanilamide molecule. In the present paper, the surface-enhanced Raman scattering (SERS) technique was employed to obtain the SERS spectra of sulfanilamide monolayers formed on the silver surface under different pH values. Assignments of the spectra were carried out with the aid of density functional theory (DFT) calculations (BLYP/6-311G). It can be found that the adsorption function of sulfanilamide on the silver surface was influenced by the pH value. The fully protonated sulfanilamide molecule adsorbed on the silver surface through N13H2 group and the benzene ring anchored in a relatively perpendicular manner leading to N7H2 and S10O2 groups near the surface, while the completely deprotonated sulfanilamide molecule attached on the silver surface via N7H2 and the benzene ring was perpendicular to, and the N13H2 and S10O2 groups were far from the silver surface. Copyright © 2009 John Wiley & Sons, Ltd.
HITTM cells—high-efficiency crystalline Si cells with novel structure

Our unique, high-efficiency c-Si solar cell, named the HIT cell, has shown considerable potential to improve junction properties and surface passivation since it was first developed. The improved properties in efficiency and temperature dependence compared to conventional p – n diffused c-Si solar cells are featured in HIT power 21TM solar cell modules and other applications which are now on the market. In the area of research, further improvement in the junction properties of the a-Si/c-Si heterojunction has been examined, and the highest efficiency to date of 20.1% has recently been achieved for a cell size of 101 cm2. The high open circuit voltage exceeding 700 mV, due to the excellent surface passivation of the HIT structure, is responsible for this efficiency. In this paper, recent progress in HIT cells by Sanyo will be introduced. Copyright © 2000 John Wiley & Sons, Ltd.
Synthesis of Ti3AlC2 Powders Using Sn as an Additive

Nearly pure Ti3AlC2 powders have been synthesized by calcining a mixture of titanium, aluminum, and graphite powders using tin powders as additives. Four recipes with different mole ratios of Ti:Al:C:Sn were examined at calcining temperatures from 1300° to 1500°C. The addition of Sn effectively inhibited the generation of thermal explosion when the volume of the starting materials is larger, and considerably reduced the lower-limit calcining temperature. The nearly pure Ti3AlC2 powders can be obtained reliably on a large scale by calcining the starting materials with a mole ratio of 3Ti:1Al:1.8C:0.2Sn at temperatures from 1350° to 1500°C.
Chemistry of Organic Nitrates: Thermal Chemistry of Linear and Branched Organic Nitrates

The objective of our research was to measure accurate rate constants for the thermal, unimolecular decomposition of organic nitrates. Our research confirms that the rate-determining step is homolytic cleavage of the weak O−N bond to form alkoxy radical and NO2, but the rate constants reported in the past are incorrect. The alkoxy radical and NO2 engage in secondary reactions that ultimately generate stable products such as carbonyl and nitro compounds. Infrared spectroscopy (IR) and gas chromatography/mass spectrometry (GC/MS) were used to monitor the time dependent loss of organic nitrate and to characterize the products of the thermal reaction. Past research indicates that oxygen slows the rate of homolytic O−N bond cleavage to form radicals. Our research shows that the rates are the same in nitrogen as they are in air. The reaction in air produces α−β unsaturated ketones/aldehydes, which are not generated in a nitrogen atmosphere. The unsaturated ketone/aldehydes complicate the IR analysis, giving the .
Surfactant stabilized palladium colloids as precursors for cis‐selective alkyne‐hydrogenation catalysts

The performance of heterogeneous catalysts based on surfactant-stabilized palladium colloids is compared with conventional Pd/C and Lindlar catalysts in the partial hydrogenation of 3-hexyn-1-ol under optimized reaction conditions. The selectivity can be influenced by the protective shell as well as by the support and various promoters. The zwitterionic surfactant sulfobetaine-12 (N,N-dimethyldodecylammoniopropanesulfonate) appears to be best suited as a protective shell for highly selective palladium-colloid catalysts under the surfactants tested. The preferred support is CaCO3: the Pd(SB12) colloids supported on CaCO3 show the highest selectivities and activities of all tested catalysts. The best selectivity (98.1%) towards the desired cis-3-hexen-1-ol (leaf alcohol) is obtained with a lead-promoted palladium colloid supported on CaCO3. This catalyst is slightly (0.5%) better in selectivity and twice as active as a conventional Lindlar catalyst. © 1997 John Wiley & Sons, Ltd.
Electrical and mechanical properties of carbon nanotube-polyimide composites

The use of carbon nanotubes (CNTs) as a conductive and high strength filler into polymer hosts has attracted great attention recently. However, in order to increase the conductivity of the polymer and to reinforce mechanically the polymer structure at low weight fraction of CNTs, the integration of the CNTs into the polymer matrix has to be effective. In this study, CNT-polyimide (CNT-Pi) composite has been fabricated by solution mixing. The electrical and mechanical properties of the composite have been investigated as a function of CNT’s loading fraction as well as temperature. It has been found that the electrical and mechanical properties of the CNT-Pi can be improved by integrating the CNTs into the polymer. In particular, the presence of an ac electric field is believed to induce dielectrophoresis (DEP), hence the possible CNT’s alignment inside the polyimide matrix during curing. The DEP effect can play an important role in enhancing the properties of the polymer matrix by reducing the percolation .
Effect of Pomace Contact on Chardonnay Musts and Wines

Wines were prepared from triplicate lots of crushed Chardonnay grapes, which were held under nitrogen for 0, 6, 12, and 24 hours of pomace contact prior to being pressed. For the musts at press and the finished wines, significant increases in pH, total nitrogen, and potassium and decreases in titratable acidity and tartaric acid were observed as pomace contact time was increased. Additionally, a significant increase in ammonia was found in the musts. In the wines, significant increases in total, flavonoid, and nonflavonoid phenols, and in malic acid were measured. The changes in concentration of these components as a function of the extent of pomace contact is illustrated by principal component analyses of the must and wine compositional data. By duo-trio tests, significant differences in wine flavor were found only between the following pairs of wines: 0 vs. 12 hours, 0 vs. 24 hours, and 12 vs. 24 hours of pomace contact. These differences, however, were too small to be characterized. No significant differences were found between pairs of these wines when compared for intensity of fruity aroma, bitterness, or acidity.
Molecular dynamics simulation of a Langmuir–Blodgett film

The structure and dynamics of a Langmuir–Blodgett film of stearic acid, physisorbed on graphite, has been examined by a combination of energy minimization and molecular dynamics. The model predicts that the molecules of this system are normal to the surface at head group areas below 21 A2, but tilted away from the normal at head group areas above 21 A2, and that this change occurs over a very small range in head group area. The system exhibited cooperative reorientations involving the average tilt and precessional angles. Gauche bond defects tended to appear near the ends of the molecules, and did not open up any significant free volume within the layer.
Bases of the Kinetics of Chemical Processes

The fundamental approach to the description of the kinetics of chemical reactions has been considered, and principle of chemical reaction independence and active mass law have been taken into account. Models for rate constants of elementary reaction have been discussed on the basis of the collision theory, the theory of activated complex, and the theory which takes into account the movement of intermediate particles to the reaction barrier. The collision theory is suggested for use at high temperatures, the theory of activated complex is recommended for application at moderate temperatures, and the theory which takes into account the movement of intermediate particle to the reaction barrier is relevant to low temperatures. It is emphasized that the principle of maximal change of free energy, which was suggested earlier, may be applied for analysis of the mechanism of chemical processes.
Kinetic evidence of reaction diffusion during the polymerization of multi(meth)acrylate monomers

The polymerization behavior and reaction kinetics for a series of multifunctional (meth)acrylate monomers were experimentally characterized and modeled with particular attention focused on the importance of the reaction diffusion mechanism in these polymerizations. In general, reaction diffusion was found to be the primary mechanism for termination beginning as low as 5% double-bond conversion. Termination mechanisms in linear systems have been found to become reaction diffusion controlled, but not until much higher conversions, 40-50%. Evidence of reaction diffusion included a significant plateau in the termination kinetic constant and strict proportionality of k p and k t , at higher conversion (>10%) for all monomers studied
Spectra– Structure Correlations in the Near‐Infrared

The sections in this article are Introduction Hydrocarbons Aliphatic Hydrocarbons Aromatics Olefins Amines and Amides Hydroxyls Alcohols Phenols Multiple Hydroxyl Compounds Carboxylic Acids Hydrogen Peroxides Water Liquid Water, Ice, and Water Vapor Water in Various Solvents Water in Other Matrices, Including Glasses Ionic Species in Water Carbonyl Compounds Miscellaneous Acknowledgments
Mass Size Distributions and Precursor Gas Concentrations of Major Inorganic Ions in'Antarctic Aerosol

Abstract Mass size distributions of major inorganic ions in aerosol particles and their atmospheric precursor gases were studied at Terra Nova Bay in Antarctica (74° 41′ 42″S, 164° 05′36 ″E) between January 30 and February 18, 1995. The mass size distributions of sulphate, the major inorganic ion, had two submicron and two supermicron modes. The accumulation mode (average mass median diameter 0.285±0.016 μn) had a very stable concentration over the whole sampling period (238.8±39.7 ng/m3). The smaller submicron mode (Aitken mode) had an averaged mass median diameter at 0.069 μm (standard deviation 0.011 μm). The existence of an Aitken mode is an indirect indication of new particle formation in the Antarctic summer atmosphere. The coarse-particle sulphate is due to the emissions of sea salt particles and their subsequent absorption of and reactions with atmospheric SO2. Ammonium was found primarily in the accumulation mode, where it probably was associated with very acidic ammonium sulphate/hydrated sulphu.
Nanostructured Sensors for Detection of Hydrogen Peroxide Vapours

Solid-state sensors made from doped metal oxide ZnO<La> and SnO2<Co> were prepared for detection of hydrogen peroxide vapours. Gas sensitive nanostructured films were manufactured by the high-frequency magnetron sputtering method. Thicknesses of deposited semiconductor nanostructured films were measured and its morphology was investigated. The average size of nanoparticles was equal to 18.7 nm for deposited films. The response of the prepared sensors was measured at different temperatures of the sensor work body and different concentrations of hydrogen peroxide vapours. It was found that both La-doped ZnO and Co-doped SnO2 sensors exhibit a sufficient sensitivity to 10 ppm of hydrogen peroxide vapours at the operating temperature 220 °C and 200 °C, respectively. It was established that the dependencies of the sensor sensitivity on hydrogen peroxide vapours concentration at the work body temperature 150 °C have a linear characteristic for both prepared structures and can be used for determination of hydrogen peroxide vapours concentration.
Quantum-Classical Molecular Dynamics Simulations of Proton Transfer Processes in Molecular Complexes and in Enzymes

A quantum-classical molecular dynamics model (QCMD) designed for simulations of proton or electron transfer processes in molecular systems is described and applied to several model problems. The primary goal of this work is the elucidation of enzymatic reactions. For example, using the QCMD model, the dynamics of key protons in an enzyme's active site might be described by the time-dependent Schroedinger equation while the dynamics of the remaining atoms are described using MD. The coupling between the quantum proton(s) and the classical atoms is accomplished via extended Hellmann−Feynman forces, as well as the time dependence of the potential energy function in the Schroedinger equation. The potential energy function is either parametrized prior to the simulations or can be computed using a parametrized valence bond (VB) method (QCMD/VB model). The QCMD method was used to simulate proton transfer in a proton bound ammonia−ammonia dimer as well as to simulate dissociation of a Xe−HI complex in its electro.