Miracle-dz/UniFAR-FTUs huggingface dataset:
DEVELOPMENT AND VALIDATION OF HPTLC METHOD TO DETECT CURCUMIN AND GALLIC ACID IN POLYHERBAL FORMULATION

Curcumin and Gallic acid are one of the phytoconstituents present in Curcuma longa and Emblica officinalis, respectively. Both these plants are used traditionally in the treatment of cancer and for the treatment of leukemia. In the present study, an attempt has been made to develop a HPTLC method for quantitative estimation of curcumin and gallic acid in different anticancer polyherbal formulations. The method employed TLC aluminum plates precoated with silica gel 60 F254 as the stationary phase. The solvent system consisted of chloroform:ethyl acetate:formic acid (7.5 mL + 6 mL + 0.5 mL). This system was found to give compact spots for curcumin (Rf value of 0.55 ± 0.02) and for gallic acid (Rf value of 0.26 ± 0.03). Densitometric analysis of curcumin and gallic acid were carried out in the absorbance mode at 254 nm. This HPTLC method was found to be reproducible, accurate, and can detect curcumin and gallic acid at a nanogram level. The developed HPTLC method would be an important tool in the quality control method for polyherbal formulations.
Thermal decomposition processes in aromatic‐aliphatic polyamides investigated by mass spectrometry

The thermal decomposition processes of some aromatic-aliphatic polymides, derived from terephthalic acid and aliphatic diamines, were studied by flash Pyrolysis-GCMS and by direct Pyrolysis-Mass Spectrometry, using both Chemical lonization and Electron Impact modes. The results indicate that the primary thermal decomposition proceeds via a β-CH hydrogen transfer process, with formation of pyrolysis products containing amide and olefin end-groups. Nitrile end-groups are also formed by dehydration of the amide groups formed in the primary decompostion process.
Photo-induced surface reaction of highly oriented anatase polycrystalline films synthesized using a CVD apparatus operated in atmospheric regime

High-rate growth of polycrystalline anatase films was achieved on non-epitaxial substrates using a chemical-vapor-deposition technique operated under air atmosphere. As the growth rate of each crystalline face was strongly dependent on the deposition conditions, four types of anatase polycrystalline films were fabricated with several oriented as , , and . The photo-induced surface reaction of the anatase films was evaluated by the reduction ability of methylene blue under ultraviolet irradiation by an ultraviolet fluorescent lamp. The reduction rate of methylene blue was found to be affected by the preferential growth direction of crystallites.
Electrochemical Synthesis of Phenol-aniline Copolymerization Coating on 304 Stainless Steel Anodes and Coating Microstructure Analysis

Electrochemical copolymerization of phenol and aniline was achieved on 304 stainless steel anodes in neutral water solution with an electrolyte of Na2SO4O4. Compared with pit corrosion potential of different copolymer coatings, the best solution composition was 0.09 mol/L phenol and 0.01 mol/L aniline. Through infrared spectrum analysis, polyaniline structure was proved in phenol-aniline copolymer, as well as more side chains. Scanning electron microscope was used to analyze microstructure of copolymer coating, taking advantage of part solubility of phenol-aniline copolymer in tetrahydrofuran, the bifurcate network structure was observed. The copolymer coating microstructure was summarized, compared with the performance of polyphenol coatings, the reasons of corrosion resistance enhancement with the addition of aniline in electropolymerization reaction was assumed as well.
Potassium fixation in suspensions of soils of Galicia (N.W. Spain)

Abstract Potassium (K) fixation in soils treated with K‐rich fertilizer is important in limiting leaching of this ion, and thus the risk of high salinity in waters. We studied this capacity for aqueous suspensions of a group of soils of Galicia (N.W. Spain) and found that fixation increased with K dosage, increased slightly with contact time, and decreased with increasing temperature (between 3 and 40°C). Potassium fixation was barely influenced by the mineralogy of the clay fraction but was greater in soils with greater fine particle content. Modified Freundlich equation successfully modelled the effects of K addition, temperature, and contact time on fixation. The influence of temperature was greater in illitic soils than in mixed soils. The results indicate that Galician soils have little capacity for K fixation.
Electromigration kinetics of gold on a carbon thin film surface studied by scanning tunneling microscopy and scanning tunneling potentiometry

The techniques of scanning tunneling microscopy (STM) and scanning tunneling potentiometry (STP) have been used simultaneously to study the electromigration behavior of a gold covering (1–2 nm) on a carbon thin film surface over 200 h. The applied lateral direct‐current (dc) voltage gradient corresponded to a mean current density j=1×104 A/cm2. The topography of the surface was measured by alternating‐current (ac) tunneling. The spatial variation of the electric potential was determined from the dc component of the tunneling current. The surface was studied continuously without any interruptions of the tunneling contact on an area of about (2.3 μm)2. The topography and the potential distribution are drastically changed during this long‐range experiment. In considerations of the local potential drop we were able to characterize the thickness of the Au covering. In the first stage of the experiment (t<60 h) the STM/STP results indicate a flux of Au atoms from the anode to the cathode. After that coalescence.
Brownian dynamics simulation of diffusion‐influenced bimolecular reactions

A method is developed and tested for extracting diffusion‐controlled rate constants for condensed phase bimolecular reactions from Brownian dynamics trajectory simulations. This method will be useful when highly detailed model systems are employed, such as those required to explore the complicated range of interactions between enzymes and their substrates. The method is verified by comparing with exact analytical results for simple cases of spheres with uniform reactivity subject to various centrosymmetric Coulombic and Oseen slip hydrodynamic interactions. The utility of the method is illustrated for more complicated cases involving anisotropic reactivity and rotational diffusion.
Chemical model structures for soil organic matter and soils

A hypothesis for the three-dimensional structure of soil organic matter (SOM) and whole soil, based on an improved humic acid (HA) model that resulted from comprehensive investigations combining geochemical, colloid-chemical, electron-microscopic, IR, 13C-NMR, and X-ray spectroscopic as well as agri
When does electronic delocalization become a driving force of chemical bonding

Utilisation d'un modele de diagramme a croisement de courbes pour la conception des stabilites dans les agregats delocalises X n z (n=3, 4, 6; z=0, −1; X=H, Li, Na, K, F, Cl, Br, I)
Local land surface temperature response to the widespread Earth greening

Chi Chen, Dan Li, Ranga B. Myneni Boston University Abstract. Satellite observations reveal that vegetation greenness has been increasing over most parts of the global land for the past few decades – due to direct factors, i.e., human land-use management, and indirect drivers, i.e., climate change, CO2 fertilization, and nitrogen deposition. The vegetation greenness is closely related to the land surface biophysical properties (i.e. albedo, aerodynamic resistance, and surface resistance) that regulate the land surface energy budget (LSEB). There are ongoing debates on the attribution of biophysical feedbacks, which is challenging, to land surface temperature (LST) at local to regional scales. Here we use a physics-based framework called the Two Resistance Mechanism (TRM) method to address local vegetation biophysical feedbacks to LST. One goal of this study is to separate the LST changes due to vegetation biophysical feedback from those due to atmospheric changes. Another goal of this study is to quantify the LST change over the past two decades attributable to leaf area index (LAI) change, and evaluate the relative contributions through each biophysical mechanisms.
Synthesis of exfoliated polyacrylonitrile/Na-MMT nanocomposites via emulsion polymerization

Polyacrylonitrile/Na−MMT nanocomposites were synthesized through an emulsion polymerization of acrylonitrile (AN) using 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS). The silicate (Na−MMT) layers were exfoliated during polymerization. The nanocomposites were exfoliated up to 20 wt % content of pristine Na−MMT relative to the amount of AN and exhibited the enhanced storage modulus, E‘, when compared with pure PAN. Delaminated morphology of the nanocomposite was confirmed by TEM.
Thermodynamic properties of the Tschermak solid solution in Fe-chlorite: Application to natural examples and possible role of oxidation

Abstract The standard-state thermodynamic properties of 14 Å Fe-amesite [Fe4Al4Si2O10(OH)8] were calculated from the reequilibration experiments of Pana et al. (2005) and natural data bearing on the Fe-Mg partitioning between chlorite and chloritoid over a wide range of pressure (P). temperature (7), and rock composition. The combination of these data with the three-site mixing model and thermodynamic properties of daphnite proposed by Vidal et al. (2001) led us to reappraise the evolution of the Margules parameter WGAlFe with pressure and temperature. The new data [H0fFe-Am = -7607460 J/mol, . S0Fe-Am = 514.8 J/(mol·K), V0Fe-Am = 20.90 J/bar, WGAlFe = 1200 - 31T + 0.7(P - 1)] are compatible with all the natural data and reequilibration experiments, and in fair agreement with the results of synthesis. They are used to calculate the compositional evolution of chlorite with T. P, or αO2 at different bulk-system compositions. The calculated phase relations and chlorite compositions are compared with previous experiments conducted in the FeO-Al2O3-SiO2-H2O system. The addition of the Fe-amesite end-member increases the number of equilibria that can be calculated for any natural assemblage involving chlorite. Two independent equilibria are obtained for natural (Fe-Mg)-chlorite-quartz or diaspore assemblages. It is therefore possible to estimate metamorphic conditions for high-variance assemblages from the composition of chlorite. We discuss the reliability of such P-T estimates using natural chlorites occurring in low-pressure and low-temperature or medium- to high-pressure and temperature samples. Assuming that the proposed model and thermodynamic parameters are correct, these various natural data suggest that XFe3+ [= Fe3+/(Fe2+ + Fe3+)] in metamorphic chlorites is low (<0.1), whereas it can be as high as 0.3 in Si- and Mg-rich chlorites formed at low -P-T conditions.
Gas lasers pumped by runaway electrons preionized diffuse discharge

It was shown that run-away electron preionized volume (diffuse) discharge (REP DD) can be used as an excitation source of gas mixtures at elevated pressures and can produce laser emission. We report experimental and simulated results of application of the REP DD for excitation of different active gas mixtures. Kinetic model of the REP DD in mixtures of nitrogen with SF6 is developed allowing predicting the radiation parameters of nitrogen laser at 337.1 nm. Peculiarities of the REP DD development in different gas mixtures are studied, as well. It was shown that the REP DD allows obtaining efficient lasing stimulated radiation in the IR, visible and UV spectral ranges. New operation mode of nitrogen laser is demonstrated under REP DD excitation. Laser action on N2, HF, and DF molecules was obtained with the efficiency close to the limiting value. Promising prospects of REP DD employment for exciting a series of gas lasers was demonstrated. It was established that the REP DD is most efficient for pumping lasers with the mixtures comprising electro-negative gases.
Selective Halogenation of 1,4-Benzoquinones and 1,4-Naphthoquinones with Copper(II) Halide Adsorbed on Alumina

Abstract 1,4-Benzoquinone or 1,4-naphthoquinone and their derivatives have been halogenated selectively at quinonoid positions with copper(II) halide adsorbed on neutral alumina followed by refluxing in halobenzene to give mono- di-, tri- and tetra-halo-quinones.
Trace Analysis of Explosives by HPLC-Electron Capture Detection (HPLC-ECD)18

Abstract HPLC-ECD and HPLC-GC-ECD instrumentation can be conveniently applied to the trace analysis of a wide variety of explosive materials in complex matrices. Limits of detection, sensitivity, and linearity plots for a number of standard explosives have been determined. These methods have now been applied to the real world analysis of explosives in post-blast residue debris, and the overall methods have been compared and confirmed via more conventional TLC approaches.
Greatly Reduced Processing Temperature for a Solution‐Processed NiOx Buffer Layer in Polymer Solar Cells

By application of thermal annealing and UV ozone simultaneously, a solution‐processed NiOx film can achieve a work function of approximately –5.1 eV at a temperature below 150 °C, which allows the processing of NiOx that is compatible with fabrication of polymer solar cells (PSCs) on plastic substrates. The low processing temperature, which is greatly reduced from 250–400 °C to 150 °C, is attributed to the high concentration of NiOOH species on the film surface. This concentration will result in a large surface dipole and lead to increased work function. The pretreated NiOx is demonstrated to be an efficient buffer layer in PSCs based on polymers with different highest occupied molecular orbital energy levels. Compared with conventional poly(3,4‐ethylenedioxy‐thiophene):poly(styrenesulfonate)‐buffered PSCs, the NiOx‐buffered PSCs achieve similar or improved device performance as well as enhanced device stability.
PREFERENTIAL REDUCTION OF AMORPHOUS TO CRYSTALLINE IRON OXIDES BY BACTERIAL ACTIVITY

Reduction of pedogenic iron oxides by the activity of Clostridium butyricum was studied in model experiments under controlled conditions of pH, particle size (63 to 125 μm), glucose (2 percent), and anaerobic conditions. Three horizons—from a gley, pseudogley, and red clay soil, respectively—with different Feo:Fed ratios were selected as test material. Except for Fe(II) formation, pH and Eh were measured at regular intervals. In all soils the total amount of free iron oxides (Fed), as well as the crystalline Fe (Fed - Feo), decreased while Fe(II) increased. The amount of amorphous Fe (Feo) remained relatively constant in those soils low in Feo:Fed (0.1 to 0.19), but diminished in the sample with a relatively high amount of amorphous Fe (Feo:Fed = 0.78). This suggests that crystalline rather than amorphous Fe forms are dissolved preferentially by acting as terminal electron acceptors. Nevertheless, the reduction of crystalline 59Fe-labeled oxides (hematite and goethite) mixed with Fe-amorphous gley soil material (Feo:Fed = 0.78) clearly showed that oxalate-soluble Fe was attacked in preference to 59Fe-labeled crystalline Fe. The processes of Fe(III) reduction in a microsite are discussed in relation to the mechanism of Fe(II) formation in flooded soils.
The Optimization of Volumetric Displacement Can Uniformize the Temperature Distribution of Heated Ham during a Vacuum Cooling Process

Rapidity is the biggest advantage of vacuum cooling in the food industry, especially for cooked meat. However, the largest volumetric displacement does not guarantee the best temperature uniformity because the structure of the food can affect the mechanisms of heat and mass transfer in food during the vacuum cooling process. Because the temperature uniformity is one of the most important factors in the cooling effect, it is necessary to achieve a uniform temperature distribution across the portion of food by choosing the best evacuation scheme. In this paper, the volumetric displacement was varied with the pressure to conduct a vacuum cooling experiment for heated ham. The results were evaluated by measuring the real-time temperature distribution on the ham section using a sensitive infrared thermal imaging system. The results indicated that properly varying the volumetric displacement during the cooling process can not only uniformize the temperature distribution across the ham section but that it can also reduce both the weight loss and energy consumption. Consequently, a reasonable varying volumetric displacement can help improve the vacuum cooling effect.
Special Polymers for Data Memories

Microelectronics represent to a large extent the key industry in the 80′ and 90′s of this century. Progress in microelectronics, however, is directly related to progress in data storage technology. Up to now main data memories are exclusively based on silicon semiconductor devices, mass data memories—at least the most important ones—are magnetic data storage units. New on the market are non-erasable optical memories using polymers or polymer substrates (e.g., CD-ROM’s). Under development are erasable optical and electrical polymer data memories: photopolymers, LC-side chain polymers, ferroelectric polymers, and such for holographic or photo-chemical hole burning data storage. The paper describes the current state of art and compares the various developments of special polymers in an attempt to forecast the possible significance of polymer memories with high data packing densities in relation to the established technologies.
Control of crystal morphology of SBA-1 mesoporous silica

By elaborate adjustment of synthesis conditions, cubic (Pm3n) SBA-1 samples with well-defined crystal morphologies of a large number of facets have been synthesized, which are supposed to be obtained as a result of highly isotropic crystal growth under the conditions near thermodynamic equilibrium. The high-resolution transmission electron microscope image revealed regular periodicity over very large areas and this clearly indicates the crystal is a single crystal with a well-ordered mesostructure.
Theoretical Aspect of Crystallization Temperature at Maximum Crystal Growth Rate

The ratio of the temperature at which the nucleation rate or the crystal growth rate is maximum (Tc max) to the melting temperature (Tm) was predicted theoretically as a function of two parameters: one is the ratio of the activation energy of migration through the nucleus-melt interface to the heat of fusion and the other is the ratio of the mean surface energy of a mole of repeat unit to the heat of fusion. The ratios of Tc max/Tm were evaluated from the above two parameters.
The Kinetic Energy of Polyatomic Molecules

The theory of rotating axes and polyatomic molecules is extended in a form applicable to linear and anomalous molecules. It is applied to a linear tetratomic molecule and to an anomalous ammonia‐like molecule, to obtain, in each case, a Hamiltonian kinetic energy lacking first‐order terms. A second‐order perturbation calculation yields the energy of interaction between rotation and vibration for the linear molecule. The relationship to Howard's theory of ethane is also given.
Catalytic Thermal Decomposition of Ammonia–Borane by Well‐Dispersed Metal Nanoparticles on Mesoporous Substrates Prepared by Magnetron Sputtering

A method to prepare well-dispersed metal nanoparticles on mesoporous substrates has been developed that uses a magnetron sputtering technique. Pd, Ni, and Pt nanoparticles are deposited on MCM-48, a silica-based mesoporous material, with good dispersion. The samples prepared by this method showed promising catalytic effects on the thermodynamic and kinetic properties of ammonia–borane (AB) thermal dehydrogenation. Catalyst-doped AB samples started to release H2 at much lower temperatures and suppressed the emission of volatile byproducts effectively. Furthermore, foaming and volume expansion can be totally avoided. The excellent catalytic performance is due to the synergetic effect of nanoconfinement of MCM-48 and the catalytic behavior of the metal particles.
Glycerol‐Reforming Kinetics Using a Pt/C Catalyst

Catalytic steam reforming of glycerol, a by-product in biodiesel production, represents an attractive route to hydrogen. For the first time, the kinetics of the glycerol steam reforming reaction over a Pt/C catalyst was considered. Kinetic data, i.e., glycerol conversion vs. space time, were obtained experimentally by using a fixed-bed reactor and were analyzed by the integral method of analysis. It was found that in the studied ranges of temperature from 623 to 673 K and space time from 0.39 to 1.56 g h/mol the investigated reaction is of the first-order with respect to glycerol. The specific reaction rate constant at 673 K was determined to be 1.1·10 5 cm 3 /g cat h. The values of glycerol conversion predicted by the first-order kinetic model were in good agreement with those obtained experimentally. The increase in temperature, space time, and initial water/glycerol ratio caused the expected increase in hydrogen yield.
Fluidized Bed Methanation of Wood-Derived Producer Gas for the Production of Synthetic Natural Gas

For proving the concept of SNG production from wood gasification derived producer gas under real conditions, a mobile bench-scale fluidized bed reactor setup was fed with producer gas of the Fast Internally Circulating Bed (FICFB) wood gasifier in Gssing, Austria. In long-term experiments, it could be shown that the fluidized methanation catalyst allows for constantly high CO-conversion (about 98%) and CH4 concentration (about 40%) in the outlet. A similar experiment was conducted in a bench-scale reactor that allows for the measurement of axial gas phase concentration profiles by means of a movable sampling tube. It could be shown that under the chosen operation conditions, all three important reactions (methanation, water gas shift, and reforming of olefins) take place very rapidly in a region close to the reactor inlet. In the rest of the bed, the reaction of reactants transferred from the bubbles to the catalyst containing dense phase of the fluidized bed reactor is dominant.
Quartz homeotypic gallium-orthophosphate-a new high tech piezoelectric material

In the recent years, the crystallographic and physical properties of quartz homeotypic gallium orthophosphate (GaPO4) have been studied and are summarized. Compared with quartz, these crystals show higher piezoelectric coefficients and therefore a larger electromechanical coupling. Its alpha-quartz-structure is stable up to 1206 K, where a transition to a cristobalite-like structure occurs. An alpha-beta transition does not occur, because the transition temperature would be theoretically near the melting temperature of 1943 K. Nevertheless there exist temperature compensated cuts for BAW and for SAW applications. Beside the higher coupling, the most outstanding property of these crystals is their thermal stability and the very small temperature dependency of the most important physical properties. This makes GaPO4 the leading material for sensors and high temperature applications. Due to a breakthrough in the growth technology of these crystals, arising from epitaxial growth on quartz seeds, it should be possible to produce this material on an industrial scale within the next years