Miracle-dz/UniFAR-FTUs huggingface dataset:
Macrotrap Model for Charge-Carrier Transport in Low-Mobility Solids

The neutral macrotrap model of charge carrier trapping has been developed to explain the electric field (F) and temperature (T) dependence of the effective charge carrier mobility (µeff) in low mobility solids. The potential barrier for the carriers localized in the neutral macrotraps (spatially extended trapping domains) can be effectively lowered by an external electric field accessible in the experiment, making the mobility and its thermal activation field dependent. The potential of a neutral macrotrap is approximated by Φ(r)=(3kT/eσ) ln (r0/r), where r is the distance from the center of the macrotrap, r0 stands for its radius, e is elementary charge and σ is a characteristic parameter of the exponential energy distribution of point traps composing the macrotrap. The lowering of the barrier is proportional to F at low fields and to ln F at high fields. The field behavior of the effective mobility is governed by this lowering of the barrier and by its field-dependent position which, therefore, can be reached by the thermally activated carriers with a field-dependent probability in the process of carrier diffusion. The latter introduces a factor exp (-3kT/σelDF) (lD-diffusion length of the carriers) responsible for the self-consistency of the field dependence of the mobility and the Arrhenius temperature term exp [-E(F, T)/kT]. This model provides a consistent description of representative experimental data reported for low-carrier mobility crystalline and disordered solids.
A Flexible Dual-Band Antenna with Stable Radiation Pattern for Wearable Application

This paper presents a flexible dual-band antenna for wearable applications. The proposed antenna consists of radiating patch, microstrip feedline, and ground plane. The four corners of the radiating rectangular patch are etched and circular slot is cut inside the patch to resonate in the Industrial Scientific Medical (ISM) band at 2.45 GHz and 5.8 GHz. The proposed antenna is designed on flexible material. The substrate material is cotton jean with dielectric constant of 1.7, loss tangent of 0.02, and the thickness of 1 mm. The overall size of antenna is $82\times 74\mathrm{mm}^{2}$. The radiation pattern of proposed antenna is unidirectional at both frequencies. The proposed antenna has the gain of 4.09 dBi and 3.19 dBi at 2.45 GHz and 5.8 GHz, respectively. The specific absorption rate (SAR) value which effects on human body is less than 2 W/kg according to IEEE95.3 standard. The SAR values of proposed antenna are 0. 3SSW/kg and 0. 35SW/kg at 2.45 GHz and 5. S GHz, respectively, over 1 gram of mass tissue. The simulated results confirm that the proposed antenna can be used for wearable applications.
Analysis of natural coloring matters in food. 4. Methylation of cochineal color with diazomethane for the analysis of food products

Methylation with ethereal diazomethane in THF was applied to detect cochineal color by TLC. A reddish orange spot at R f 0.75 on a silica gel plate developed with chloroform-methanol-water as a solvent was derived from all of the cochineal color preparations when they were methylated. The chemical structure of the spot component employs as indicator compound of cochineal color was characterized as 3,6-di-O-methylcarminic acid methyl ester by physicochemical analysis, UV-vis, IR, 1 H and 13 C NMR, and MS
Hydrophobic cellulose nanocrystals modified with quaternary ammonium salts

An environmentally friendly procedure in aqueous solution for the surface modification of cellulose nanocrystals (CNCs) using quaternary ammonium salts via adsorption is developed as inspired by organomodified layered silicates. CNCs with a high carboxylate content of 1.5 mmol g−1 were prepared by a new route, direct hydrochloric acid hydrolysis of 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-oxidized nanofibrillated cellulose from a softwood pulp, and characterized by atomic force microscopy (AFM) and X-ray diffraction (XRD). Four quaternary ammonium cation surfactants bearing long alkyl, phenyl, glycidyl, and diallyl groups were successfully used to modify CNCs carrying carboxylic acid groups as characterized by Fourier transform infrared spectroscopy (FTIR). The modified CNCs can be redispersed and individualized in an organic solvent such as toluene as observed by scanning transmission electron microscopy (STEM). One may envision removing excess surfactant to obtain CNC with a monolayer of surfactant. The toluene suspension of the modified CNCs showed strong birefringence under crossed polars but no further chiral-nematic ordering was observed. The model surface prepared by the CNCs modified with quaternary ammonium salts bearing C18 alkyl chains showed a significant increase in water contact angle (71°) compared to that of unmodified CNCs (12°). This new series of modified CNCs can be dried from solvent and have the potential to form well-dispersed nanocomposites with non-polar polymers.
Kinetics of C2 Reactions during High-Temperature Pyrolysis of Acetylene

The kinetics of C2 radical reactions during the first stage of acetylene high-temperature pyrolysis was studied by monitoring C, C2 and C3 radicals. Quantitative C2 detection was performed by ring dye laser absorption spectroscopy, C atoms were measured by applying atomic resonance absorption spectroscopy, and C3 radicals were monitored by their emission using a combination of a spectrograph and an intensified CCD camera system. The experiments were performed behind reflected shock waves and cover the temperature range of 2580−4650 K at pressures around 2 bar. In the first part of the study initial mixtures containing Ar with 5−50 ppm C2H2 were used. In this very low concentration range, rate coefficients for the following four reactions were determined: C2H2 + M C2H + H + M (R1); C2H + M C2 + H + M (R2); C2 + C2 C + C3 (R3); C2 + M C + C + M (R4); where k1 = 6.96 × 1039 T-6.06 exp(−67 130/T) cm3 mol-1 s-1, k2 = 1.74 × 1035 T-5.16 exp(−57 367/T) cm3 mol-1 s-1, k3 = 3.2 × 1014 cm3 mol-1 s-1, and k4 = 1.5 .
Ion Pairs of 5,5-dimethyl-2-(2-hydroxy-3,5-disulfophenylhydrazo)cyclohexane-1,3-dione with Cationic Surface-Active Substances as Analytical Reagent for Determination of Copper(II)

A new organic reagent, 5,5-dimethyl-2-(2-hydroxy-3,5-disulfophenylhydrazo)сyclo-hexane-1,3-dione (H2L), was synthesized by azo coupling of diazonium salts of 2-hydroxy-3,5-disulfoaniline with dimedone. The dissociation constants of H2L were determined by potentiometric titration, being pK 1 = 5.90 ± 0.03 and pK 2 = 9.67 ± 0.04. The interaction in systems of H2L and cationic surface-active substances (CSAS), cetylpyridinium chloride (CPCl), cetylpyridinium bromide (CPBr), or cetyltrimethylammonium bromide (CTABr) was studied in the presence and absence of Cu(II). It was found that the detection limit of Cu(II) using H2L–CSAS pairs decreases in accord with the stability of associates H2L(CPCl)2 > H2L(CPBr)2 > H2L(CTABr)2 and their copper(II) complexes Cu[(HL)(CPCl)2]2 > Cu[(HL)(CPBr)2]2 > Cu[(HL)(CTABr)2]2. The effects of foreign ions and masking substances on the complexation were studied and showed that the reaction of Cu(II) with H2L in the presence of CSAS is more selective. Based on these observations, a procedure for the spectrophotometric determination of copper(II) in soils polluted by oil, seawater, igneous rock, and nickel-based alloys was developed.
Accurate Monoisotopic Mass Measurements of Peptides: Possibilities and Limitations of High Resolution Time-of-flight Particle Desorption Mass Spectrometry

The possibilities and limitations of time-of-flight particle-desorption mass spectrometry are analysed from the standpoint of accuracy of monoisotopic mass determination. For an instrument with mass reflector, typical mass accuracy was found to be ca. 20 ppm (standard deviation). The main limitation was found to be the mechanism of secondary ion production itself. A fraction of biological ions are formed in the gas phase and therefore exhibit both time delay and energy deficit. This leads to a limited resolving power and non-symmetric ion peaks. A peak shape model, taking into account gas-phase ion formation, is built and analysed, and a simple correction procedure proposed. The application of the correction has increased the mass accuracy to 12 ppm (standard deviation). It is shown that further progress cannot be achieved by a correction procedure without instrumental improvements.
Catalytic synthesis of crystalline SiC nanowires from a Ni/a-C/Si sandwich configuration

High quality 3C-SiC nanowires are synthesized via thermal treatment of Ni/a-C/Si sandwich films. The nanowires obtained at 900 °C, under a low partial pressure of oxygen, consist of 20–50 mm diameter cores coated by an amorphous phase. The formation of 3C-SiC involves solid–liquid–solid mode and vapor–liquid–solid processes. The ability to synthesize SiC nanowires under the fabrication conditions, both relatively low temperature and a small amount of oxygen, represents an important advance towards their eventual integration for various technological applications.
Transfer of Protonated Anesthetics across the Water|o-Nitrophenyl Octyl Ether Interface: Effect of the Ion Structure on the Transfer Kinetics and Pharmacological Activity

Voltammetric and impedance measurements were used to study the transfer of protonated forms of local anesthetics (procaine, tetracaine, cocaine, prilocaine, bupivacaine, lidocaine, dibucaine) between water (W) and o -nitrophenyl octyl ether ( o -NPOE). The ion structure was shown to have little effect on the ion transport properties in the bulk aqueous phase, as characterized by the diffusion coefficient, D ^w=(7 - 10) × 10^-6 cm^2 s^-1, as well as in the bulk o -NPOE phase, as characterized by the diffusion coefficient D ^0=(5 - 6) × 10^-7 cm^2 s^-1, and at the W | o -NPOE interface, as characterized by the apparent standard rate constant, k _0^s=0.013 cm s^-1. While ion transport in the bulk of a phase is influenced mainly by the ion size and medium viscosity (Stokes law), the rate of interfacial ion transfer comprises the contributions of the ion distribution in the electrical double layer and of the activated transfer step, which compensate largely for each other. The pharmacological activity of local anesthetics correlates with the standard potential differences of their protonated forms at the W| o -NPOE interface. This activity can be related to the ion partition between the body fluid and the membrane, or to the rate of membrane ion transfer at a constant potential difference.
Emissions of Volatile and Semi-Volatile Organic Compounds and Particulate Matter from Hot Asphalts

Asphalts are widely used in paving of roads, and water-proof sealing of building roofs, tanks and containers. This study evaluated the qualitative and quantitative characteristics of emissions from hot asphalts and bitumen that included reactive organic gases (ROGs) and particulate matter (PM). The ROGs consisted of several volatile organic compounds (VOCs), and semi-volatile organic compounds (SVOCs) of environmental concern. The latter included several polynuclear aromatic hydrocarbons (PAHs) and alkanes. An experimental laboratory testing, sampling and analysis protocol was developed for obtaining efficient and cost-effective a priori estimates of asphalt emissions. The investigation identified and quantified the emissions of organics and evaluated the magnitudes as well as particle size distributions of PM emissions. The study demonstrated that the asphalt type and temperature greatly affected the emission characteristics, and that several organic compounds emitted were partitioned between gaseous and.
Crystal structure of holmium trisilicide, HoSi3

HoSi3, tetragonal, I4/mmm (no. 139), a = 7.2047(2) Å, c = 10.6861(7) Å, V = 554.69(4) Å, Z = 8, R(I) = 0.034, R(P) = 0.038, T = 293(2) K.
MODEL SYSTEMS FOR FLAVOENZYME ACTIVITY : ONE- AND TWO-ELECTRON REDUCTION OF FLAVINS IN APROTIC HYDROPHOBIC ENVIRONMENTS

The processes occurring during the electrochemically irreversible reduction of flavins in aprotic organic medium have been the cause of considerable controversy. To provide insight into these events we have investigated the reduction of flavins alkylated at N(3). We have demonstrated that the reversible reduction of N(3)-methylated flavin can be converted to the irreversible reduction observed with unalkylated flavins through addition of the weak external proton donor phthalimide. Proton transfer to the flavin radical anion generated at the electrode leads to partial formation of the neutral flavin radical, which is instantaneously further reduced to the fully reduced flavin anion. This mirrors the reduction of unalkylated flavins, where the proton source is the imide proton at N(3) of fully oxidized flavin in bulk solution. Simultaneous electrochemistry and EPR experiments confirm the disappearance of electrogenerated flavin radical anion both methylated and non-methylated at N(3), upon addition of phtha.
Arrays of microplasmas for the controlled production of tunable high fluxes of reactive oxygen species at atmospheric pressure

The atmospheric-pressure generation of singlet delta oxygen (O2(a 1Δg)) by microplasmas was experimentally studied. The remarkable stability of microcathode sustained discharges (MCSDs) allowed the operation of dc glow discharges, free from the glow-to-arc transition, in He/O2/NO mixtures at atmospheric pressure. From optical diagnostics measurements we deduced the yield of O2(a 1Δg). By operating arrays of several MCSDs in series, O2(a 1Δg) densities higher than 1.0 × 1017 cm−3 were efficiently produced and transported over distances longer than 50 cm, corresponding to O2(a 1Δg) partial pressures and production yields greater than 5 mbar and 6%, respectively. At such high O2(a 1Δg) densities, the fluorescence of the so-called O2(a 1Δg) dimol was observed as a red glow at 634 nm up to 1 m downstream. Parallel operation of arrays of MCSDs was also implemented, generating O2(a 1Δg) fluxes as high as 100 mmol h−1. In addition, ozone (O3) densities up to 1016 cm−3 were obtained. Finally, the density ratio of O2(a 1Δg) to O3 was finely and easily tuned in the range [10−3–10+5], through the values of the discharge current and NO concentration. This opens up opportunities for a large spectrum of new applications, making this plasma source notably very useful for biomedicine.
Phase equilibrium of ethanol + CO{sub 2} and acetone + CO{sub 2} at elevated pressures

Vapor-liquid equilibria for two binary mixtures at elevated pressures were determined by a novel technique of density measurement. In this investigation using two high-pressure densitometers, phase diagrams for carbon dioxide + ethanol and carbon dioxide + acetone mixtures were established at five temperatures and pressures up to 14.39 MPa. Solubilities of carbon dioxide in both ethanol and acetone were found to increase with applied pressure but decreased with increasing temperature. The solubility for carbon dioxide in acetone was found to be greater than that of carbon dioxide in ethanol.
Selective Deposition in Layer-by-Layer Assembly: Functional Graft Copolymers as Molecular Templates

A new approach to creating patterned composite structures with layer-by-layer assembled thin films is introduced. In this approach, the top surfaces of layer-by-layer films are chemically patterned by the direct stamping of functional polymers on the surface. The resulting pattern is then used as a template for the further deposition of materials on the surface. This paper illustrates this concept through the patterning of an oligoethylene glycol resist atop a polyelectrolyte multilayer surface. The resist layer is created by stamping an oligoethylene oxide−maleic anhydride graft copolymer onto the top polyamine surface. Further deposition of polyions results in the formation of a patterned polymer film atop the original multilayer thin film. When a patterned polyelectrolyte film is used as the base layer or substrate in this process, a second pattern can be stamped atop the original patterned array. Subsequent selective adsorption of polymers yields a second level of microstructures, illustrating the con.
Axisymmetric Thermophoresis of Multiple Aerosol Spheres

ABSTRACT A semianalytic study of the thermophoretic motion of a finite chain of aerosol spheres along the line through their centers is presented. The spheres may differ in radius, in thermal conductivity, and in surface properties, and they are allowed to be unequally spaced. Also, the spheres can be either freely suspended in the gaseous medium or connected by infinitesimally thin rods. The Knudsen numbers are assumed to be small so that the fluid flow is described by a continuum model with a thermal creep and a hydrodynamic slip at the particle surfaces. Through the use of a boundary-collocation method, a set of energy and momentum equations governing this problem is solved in the quasisteady limit and the interaction effects are computed for various cases. For the thermophoretic motion of two-sphere systems, our numerical results for the particle velocities agree very well with the exact calculations using spherical bipolar coordinates. For the cases of two or three spheres touching one another, the n.
Pyrazine chemistry. II. Reduction of 3,6-Dibenzylidenepiperazine-2,5-diones

A reinvestigation of the reduction of 3,6-dibenzylidenepiperazine-2,5-dione (1) with zinc and acetic acid established that this reaction gave (Z)-6-benzyl-3-benzylidenepiperazine-2,5-dione (10). When a mixture of acetic acid and hydrochloric acid was used in the reduction, a mixture of trans- (12) and cis-3,6-dibenzylpiperazine-2,5-dione (5) was obtained. Direct catalytic reduction of 3,6-di(2-chloro- benzy1idene)piperazine-2,5-dione (2) to (±)-cis-3,6-di(2-chlorobenzyl)piperazine-2,5-dione (6) was also accomplished.
The performance optimization and specific adsorption of L-phenylalanine imprinted polymers using 1-vinyl-3-carboxymethylimidazolium chloride as functional monomer

L-Phenylalanine (L-Phe) imprinted polymers (L-MIPs) were prepared via precipitation polymerization using 1-vinyl-3-carboxymethylimidazolium chloride ([VCIM]Cl) as functional monomer, which could interact with L-Phe through electrostatic interactions, hydrogen-bonding, and π–π interactions. The morphologies of obtained polymers were observed by a scanning electron microscope, and their structures were analyzed by Fourier transform infrared spectroscopy. The effects of monomer species and molar ratio of template to functional monomer or crosslinker on adsorption capacity and imprinting factors (IFs) of polymers were investigated. The result indicated that [VCIM]Cl was preferable monomer and the optimum molar ratio of template to functional monomer and crosslinker was 1:4:16. The maximum IF of the obtained L-MIPs could reach 3.86 in 0.4 mg mL−1 L-Phe solution at 25 °C, after 8 h of adsorption and the maximum adsorption capacity of L-MIPs for L-Phe was 33.08 mg g−1. The adsorption behavior of L-Phe on the L-MIPs was construed seriously within the experimental concentration by Freundlich model and Langmuir model. In terms of the higher correlation coefficient, it was considered that the adsorption behavior of L-Phe fit Freundlich model better than Langmuir model, which means that the distribution of active sites was heterogeneous in L-MIPs. The selectivity adsorption showed L-MIPs have better specificity and selectivity for L-Phe than that of L-His and L-Trp. Finally, L-MIPs were applied to the CD and Automatic Polarimeter experiments, showing that L-MIPs had the capability of specific chiral recognition for L-Phe.
HPTLC Quantification and Antimicrobial Activity of Ursolic Acid from Diospyros melanoxylon

An important bioactive molecule, ursolic acid was isolated from the leaves of Diospyros melanoxylon and characterized with help of physical and spectroscopic data viz. m. p, IR, 1H, and 13C NMR. A high-performance thin-layer chromatography method has also been developed and validated for its quantification in D. melanoxylon leaves. The high-performance thin-layer chromatography analysis was performed on high performance thin-layer chromatography plates using chloroform-methanol (9.5:0.5, v/v) as mobile phase. The compound was quantified at 540 nm after derivatzation with sulphuric acid reagent. The sensitivity of the method with respect to limit of detection and limit of quantification were found to be 20 and 40 ng per spot. The response was obtained as a linear function of peak area and concentration in the range of 50 to 450 ng per spot with correlation coefficient of r2 = 0.9998. The method showed excellent accuracy greater than 97.54% with acceptable precession and was successfully validated according to International Conference of Harmonization protocols. Antimicrobial screenings of ursolic acid revealed potent activity against two Gram-positive bacteria viz. Staphylococcus aureus and Enterococcus faecalis and three fungal starins viz. Aspergillus niger, Candida tropicalis, and Candida albicans.
Microporous Structure of a Chain Compound of Copper(II) Benzoate Bridged by Pyrazine

Reaction of copper(II) benzoate with pyrazine (pyz) gave a compound, [Cu2(bz)4(pyz)]n (1) which has a gas-occlusion property. The X-ray structure analysis of 1·2nCH3CN shows a microporous structure formed by chains where the carboxylate dimer units are linked by pyrazine molecules.
Mild Combustion: Process Features and Technological Constrains

Abstract The Mild Combustion is a relatively novel combustion technique characicrized by both an elevated temperature of reactants and an adiabatic flame temperature not higher than 1600K. These features are the results of several technological demands coming form different application fields. The main advantages derived by Mild Combustion concern both the combustion process itself and its applications. In the former case the pollution reduction, the increase of efficiency process and fuel flexibility has to be considered whereas the latter one is principally related to heat treatment process and wall confinement. In this paper, characteristics of Mild Combustion arc discussed with particular regards towards the aspects of plant design. A general classification of the processes, where initial and adiabatic temperature values are different from characteristic ones of classical combustion system, is given. This classification leads to a definition of Mild Combustion process as a direct consequence of technological evolution and practical constrains, especially related to environmental problems. In this sense, the high temperature of reactants and the low adiabatic temperature, principally obtained using exhausts for both heat recovery and dilution, can not be considered independently. Application of Mild Combustion in practical systems infers the use of particular solutions because of high temperature of reactants involved. In the final part of the paper, specific solutions utilized in a laboratory mild combustor are presented.
Macroporous Electrically Conducting Carbon Networks by Pyrolysis of Isocyanate-Cross-Linked Resorcinol-Formaldehyde Aerogels

Carbon (C) aerogels are made by pyrolysis of resorcinol-formaldehyde (RF) aerogels under Ar, and they combine electrical conductivity with a high open mesoporosity. However, because macropores are known to facilitate mass transfer, macroporous C-aerogels could be useful for application in separations or as fuel cell and battery electrodes. Macropores are typically incorporated in C-aerogels during gelation of the RF precursors by using either “hard” templating with silica or polystyrene beads, or “soft” templating with surfactants. Here, we report an alternative method, where open macroporosity is introduced by pyrolyzing RF aerogels whose skeletal nanoparticles have been cross-linked covalently with an isocyanate-derived polymer that coats conformally the entire RF framework. The structural, physical, and chemical evolution of the X-RF network was monitored at various stages during pyrolysis by DSC, TGA, SEM, N2 adsorption porosimetry, and 13C NMR. The accumulated evidence shows that the cross-linker fir.