Miracle-dz/UniFAR-FTUs huggingface dataset:
Investigation of atomic oxygen density in a capacitively coupled O2/SF6 discharge using two-photon absorption laser-induced fluorescence spectroscopy and a Langmuir probe

Two-photon absorption laser-induced fluorescence (TALIF) spectroscopy was used for detection of absolute atomic oxygen density in a low-pressure capacitively coupled plasma source. We investigated the variation of atomic oxygen density for various mixtures of O2/SF6 and report a significant five-fold increase of [O] when oxygen plasma was diluted with SF6 by only 5%. We attribute this increase in [O] to a combination of a change in surface conditions caused by constituents of SF6 plasma reacting with the reactor walls and also due to an increase in the electron temperature. Atomic oxygen production rates were determined using electron-energy distribution functions obtained with a cylindrical Langmuir probe. It was found that the effective electron temperature dramatically increased from approximately 1–8 eV as the SF6 content varied from 0% to 60% which consequently resulted in a three-fold increase in the atomic oxygen production rate. TALIF was also used to investigate the variation of [O] due to fluorination of the reactor walls and also after etching resist-coated wafers. It was found that [O] increased by over a factor of three after fluorinating the walls with SF6 plasma; on the other hand a coating formed on the reactor walls after a resist etch process resulted in a reduction of [O] by only 20%.
Synthetic Studies Directed towards Agelasine Analogs -Synthesis, Tautomerism, and Alkylation of 2-Substituted N-Methoxy-9-methyl-9H-purin-6-amines

N-Methoxy-9-methyl-9H-purin-6-amines, carrying various substituents in the 2 positions, were synthesized by the N-methylation of known 6-chloropurines, followed by a displacement of the chlorine. Great variations in the amino/imino tautomer ratio among the compounds studied were observed. The tautomers were identified by NMR methods. Treatment of N-methoxy-9-methyl-9H-purin-6-amines carrying alkyl, alkoxy, or amino substituents in the 2 position with benzyl bromide resulted in a mixture of N-7- and N6-benzylated compounds with the former as the major products. N-Methoxy-9-methyl-9H-purin-6-amines with strongly electronegative substituents at C-2 hardly reacted at all under the same set of reaction conditions. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
A new universal long-wave radio intensity measuring set

In this paper it is pointed out that the existing long-wave measuring apparatus has been found not sufficiently refined for the more complicated observations now required in the study of the polarization of radio waves; and a detailed description is given of a new apparatus for the purpose, which is primarily designed to measure in rapid succession the E.M. F. 's in two coils oriented in different directions to the arriving signal, and the phase angle between these two E.M. F. 's.
Evaluation of Mehlich‐III extractant to estimate the available P in Quebec soils

Abstract The Mehlich‐III method used for the determination of available P in 82 Quebec soils was compared to five other chemical methods (Bray‐II, Bray‐I, Mehlich‐II, Mehlich‐I and Olsen) and to two anion exchange resin techniques (F‐ and HCO‐ 3) In general, very good correlations were found between Mehlich‐III, Bray‐II and Bray‐I methods on acid soils (r=0.95** and 0.98**). The Mehlich‐III‐P content is somewhat the same as that determined by Bray‐I and corresponds approximately to 80% of Bray‐II‐P. The Mehlich—III extractant was found to be more reliable than Bray‐II and Bray‐I on very acid spodosols having high P‐sorption capacity. The Bray methods, with high NH4F concentration, extracted strongly fixed Al‐P in these soils and may overestimate the available P. In some acid soils containing apatite and in calcareous soils, the Bray‐II and Mehlich‐I (double acid) easily dissolved these Ca‐P compounds and gave exaggerated high P values. The Mehlich‐III and the other methods were less vigourous for these co.
Preparation of acacia‐stabilized silver nanoparticles: A green approach

We report a facile approach for the spontaneous formation of silver nanoparticles in the presence of gum acacia polymer (a natural polymer) without the addition of any typical reducing agent under mild conditions. Silver nanoparticles (∼ 5 nm) have been obtained by the mixing of equal amounts of 0.5 wt % aqueous solutions of acacia and silver nitrate. The formation of silver nanoparticles has been confirmed with ultraviolet-visible, Fourier transform infrared, X-ray diffraction, and X-ray photoelectron spectroscopy analyses. Gum acacia polymeric chains promote the reduction process and act as good stabilizers over 5 months. To confirm the formation and stabilization of the nanoparticles, a transmission electron microscope has been employed. The advantage of this methodology is that it is possible to prepare silver nanoparticles without any organic solvents or reducing agents.
Formation of polypeptide-dye multilayers by electrostatic self-assembly technique

To demonstrate the feasibility of preparing ordered multilayers composed of charged macromolecule/dye bilayers, we used an electrostatic self-assembly technique to prepare polypeptide/dye multilayers. We immersed previously protonated silanized glass slides in aqueous solutions (1 mM) of two representative anionic dyes : rod-shaped congo red or plate-shaped copper phthalocyanine tetrasulfonic acid sodium salt and cationic polypeptidepoly(L-lysine) solutions (15 mM monomer). Films resulting from up to 100 dipping cycles were characterized by UV-vis absorption spectra, ellipsometry, CD, and FT IR. FT IR spectra of film material embedded in KBr pellets showed an amide I band at 1654 cm -1 , suggesting thin film α-helical conformation. In both systems, the dye absorbance increased with the number of layers. In the copper phthalocyanine system, the absorption spectrum was a combination of phthalocyanine monomer and dimer contributions, with no evidence of higher aggregates. The congo red film dye absorption maximum was a function of the number ofbilayers, suggesting congo red resided in a polar, hydrophilic environment that became less polar with increasing bilayer number. From ellipsometry measurements, the bilayer thickness in both films was determined to be 20 A. The phthalocyanine Q band showed negative-induced CD, while the congo red ππ * band exhibited positive-induced CD. The CD measurements gave evidence for ordered dye-polypeptide complexes in films greater than 100-A thickness. The current work suggested a bilayer structure where monomeric congo red or dimeric copper phthalocyanine tetrasulfonate were randomly distributed among excess poly(K) monomer bindings sites, giving clear films with no scattering centers.
Vibrational spectrum of the H5+ molecule using quantum Monte Carlo

In this article we present a caracterization of the vibrational spectrum of the H5+ molecule using the correlation function quantum Monte Carlo (CFQMC) method and a genetic algorithm study of the topology of the potential energy surface used in this work. The vibrational modes associated with the H3+ - H2 torsion and stretching posses very flat minima. As a consequence the fundamental frequencies corresponding to these modes are poorly described in the harmonic approximation. The vibrational frequencies obtained in this work are in good agreement with the available experimental data as well as other computational methods found in literature. In our genetic algorithm study of the potential energy surface using cartesian coordinates we have found some unexpected minima. A careful analysis shows that some of these minima are described by the same curviliniar coordinates in which the potential is described. However, they represent nonequivalent molecular geometries.
Near-real time 3D probabilistic earthquakes locations at Mt. Etna volcano

Automatic procedure for locating earthquake in quasi-real time must provide a good estimation of earthquakes location within a few seconds after the event is first detected and is strongly needed for seismic warning system. The reliability of an automatic location algorithm is in[U+FB02]uenced by several factors such as errors in picking seismic phases, network geometry, and velocity model uncertainties. On Mt. Etna, the seismic network is managed by INGV and the quasi-real time earthquakes locations are performed by using an automatic-picking algorithm based on short-term-average to long-term-average ratios (STA/LTA) calculated from an approximate squared envelope function of the seismogram, which furnish a list of P-wave arrival times, and the location algorithm Hypoellipse, with a 1D velocity model. The main purpose of this work is to investigate the performances of a different automatic procedure to improve the quasi-real time earthquakes locations. In fact, as the automatic data processing may be affected by outliers (wrong picks), the use of a traditional earthquake location techniques based on a least-square misfit function (L2-norm) often yield unstable and unreliable solutions. Moreover, on Mt. Etna, the 1D model is often unable to represent the complex structure of the volcano (in particular the strong lateral heterogeneities), whereas the increasing accuracy in the 3D velocity models at Mt. Etna during recent years allows their use today in routine earthquake locations. Therefore, we selected, as reference locations, all the events occurred on Mt. Etna in the last year (2011) which was automatically detected and located by means of the Hypoellipse code. By using this dataset (more than 300 events), we applied a nonlinear probabilistic earthquake location algorithm using the Equal Differential Time (EDT) likelihood function, (Font et al., 2004; Lomax, 2005) which is much more robust in the presence of outliers in the data. Successively, by using a probabilistic non linear method (NonLinLoc, Lomax, 2001) and the 3D velocity model, derived from the one developed by Patanè et al. (2006) integrated with that obtained by Chiarabba et al. (2004), we obtained the best possible constraint on the location of the focii expressed as a probability density function (PDF) for the hypocenter location in 3D space. As expected, the obtained results, compared with the reference ones, show that the NonLinLoc software (applied to a 3D velocity model) is more reliable than the Hypoellipse code (applied to layered 1D velocity models), leading to more reliable automatic locations also when outliers are present.
Synthesis and Characterization of Fumarate Copolyesters for Use in Bioresorbable Bone Cement Compositions

Unsaturated amorphous copolyesters of varied composition were prepared by transesterification copolymerization of diethyl fumarate, and two diols, 1,2‐propanediol and 2‐methyl‐1,3‐propanediol. The copolyesters were characterized by IR, 1H‐ and 13C‐NMR, GPC, DSC, and TGA. The glass transition is changing with composition from 0°C to 19°C as the content of 1,2‐propanediol residue in the copolyester increases. The copolyester structure and composition have an impact on the compressive strength and hydrolytic stability of the composites prepared by crosslinking the fumarate double bonds with N‐vinyl pyrrolidone in the presence of inorganic filler, calcium sulfate dihydrate, with the addition of a radical initiator, benzoyl peroxide, at ambient temperatures.
The Electro-Physical Properties of Rhenium Chalcogenides' Thin Films

The electro-physical properties of thin layers of rhenium chalcogenides' alloys, their dynamical and static ampere-voltaic characteristics were investigated. During the investigation of static and dynamical ampere-voltaic characteristics of rectifying contact of aluminium and rhenium chalcogenides' alloys the switching effects were found.
Influence of surface roughness scattering on electron low‐field mobility in thin undoped GaAs‐in‐Al2O3 nanowires with rectangular cross‐section

The influence of surface roughness scattering on electron low‐field mobility in thin undoped GaAs‐in‐Al2O3 nanowires with rectangular cross‐section is studied by means of the direct numerical solution of the Boltzmann transport equation at the electric quantum limit for different values of the nanowire cross‐section dimensions, the nanowire temperature and the Fermi level in a one‐dimensional electron gas. The formulae for calculation of surface roughness scattering matrix elements are derived in such a way that they contain the topological parameter Δ2D characterizing the surface roughness instead of the physical one, Δ1D, usually used.
Experimental and theoretical investigations on the direct interactions between urea and phospholipids in aqueous solutions

Experimental and theoretical investigations have been carried out on the interactions of urea and, as a comparison, water with phospholipids. Firstly, Langmuir monolayer technique demonstrated that the presence of urea in the subphase caused a lateral expansion of the molecular monolayer of dipalmitoylphosphatidylcholine (DPPC) and a number of other phospholipids. This is attributed to possible direct interaction between urea and the lipids and thus insertion of urea into the head group region. Secondly, Raman spectra showed that the N-H stretching bands of urea shift to lower wavenumber while the symmetric stretching mode of PO2 of lipids shift to higher wavenumber, when urea coexists with DPPC in aqueous codispersions. This is consistent with the formation of hydrogen bonds between urea and DPPC molecule. Thirdly, quantum chemical calculations of the first principle demonstrated that the interaction of urea with lipid's amino group, phosphate group, and glycerol backbone are significantly stronger than that with water. Hence it is concluded that urea can interact specifically with the headgroup of phospholipids in an aqueous solution. The results would be helpful to understand the effect of urea on biomembranes and other biomolecular structures.
Proof-of-Concept Study of Smart Panel for Space Structures

Verification of a spacecraft structure is a process in which the structural mathematical model, usually finite element model, is compared with the test results to confirm the validity of the structural design. The ultimate structural requirements with the high accuracy and the high stability motivate space engineers to evaluate the structural issues, such as micro-vibration and zero thermal expansion, more precisely on the ground tests. In addition, it would be significant to verify the structural design using the data obtained on orbit since the ground test environments cannot be perfectly equal to the space environments. Author proposed “Sensor Integrated Smart Panel for Space Structure” to enable both the precise structural measurements and the verification on orbit. In this study, fiber optic sensors were integrated with a honeycomb sandwich panel, which consist of CFRP skins and Aluminum honeycomb core. The size of the panel is 300 mm x 300 mm and the weight is approximately 500 grams including mechanical inserts. Four sensor lines with over 30 FBGs were integrated between the CFRP skin and the honeycomb core in the process of bonding. The most remarkable feature of the panel is the design of the optical fiber interface at the edge of the panel. Optical connectors were also integrated with the panel and user (e.g. satellite integrator) can easily access to the FBGs with FC/APC interface without any special tools. Then, the panel was tested in the thermal vacuum chamber to evaluate the durability and the performance of the sensors under the space environment. As a result, the smart panel could endure high vacuum (below 10-5 Pa) and low temperature (below 200K). The sensor output was very stable and low noise, 0. 6μe in standard deviation within 1°C temperature variation in 30 minutes.
FORCE TRANSDUCER MODELING OF RECTANGULAR, V–SHAPED, AND DAGGER CANTILEVER PROBES BASED ON ATOMIC FORCE MICROSCOPY

Real-time monitoring of the nano-particle manipulation process by atomic force microscope (AFM) is almost impossible since the manipulator of the AFM is used as either the imaging or manipulation tool at a given instant. As one approach to this problem, researchers scan the area where the target particle exists, before and after the nano-manipulation. Thus, by using some fixed reference features, the new relative position of the particle is obtained from the images. However, this imaging is offline, and unexpected problems during nano-manipulation process cannot be detected. In this article, force transducer of the AFM rectangular, V-shaped, and dagger cantilevers, which convert the three-dimensional deflections measured by the detection system to corresponding three-dimensional force, are modeled and compared. So there would be a feedback from the real-time force system during nano-manipulation process, which can be utilized for better understanding and reliable handling of nano-particles. Furthermore, the manipulation forces are affected directly by spring constants of cantilever. Hence, the cantilever is the most significant and sensitive component of the AFM. Therefore, variations of the lateral, longitudinal, and normal spring constants of the mentioned cantilever for different geometrical parameters are analyzed and discussed.
Mechanism of Slow Desorption of Organic Compounds from Sediments: A Study Using Model Sorbents

The desorption kinetics of PCBs and chlorobenzenes have been studied at 5, 20, and 60 °C for model sorbents in which either micropore diffusion (zeolite, montmorillonite, and XAD-8) or organic matrix diffusion/entrapment (rubbery polyacetal and glassy polystyrene) could occur. Also, a sediment was studied whose organic matter (OM) had been completely removed. All sorbents exhibited slow desorption (rate constants (1−5 × 10-3 h-1). The sediment without OM showed significantly smaller slowly desorbing fractions (factor 3−8) than the original sediment (about 6% OM). Sorbent−water distribution ratios of the microporous sorbents and the sediment without OM were 10−100 times lower than the ones of the original sediment. So, although the presence of both mineral micropores and/or OM can result in slow desorption behavior of organic compounds from soils and sediments, OM is more important for slow desorption than mineral micropores in sediments with more than about 0.1−0.5% OM. The sorption and desorption paramet.
Study of densities, viscosity deviations, and isentropic compressibilities of ternary liquid mixtures of water and ethane-1,2-diol with some monoalcohols at various temperatures

Excess molar volume (VE ), viscosity deviation (Δη), and excess Gibbs energy of activation (ΔG*E ) of viscous flow have been investigated from the density (ρ) and viscosity (η) measurements of ternary liquid mixture of water + ethane-1,2-diol + methanol, water + ethane 1,2-diol + ethanol, and water + ethane-1,2-diol + 1-propanol over the entire range of composition at 298.15, 308.15 and 318.15 K. The speeds of sound are also observed for these mixtures and thus, the isentropic compressibility (K S) and excess isentropic compressibility ( ) calculated at 298.15 K. The results are discussed in terms of specific interactions and nature of liquid mixtures. The system studied here exhibits a very strong cross association through hydrogen bonding.
The net distribution of elements in multiphase polymer materials via element-specific electron microscopy

Application de l'imagerie de spectroscopie electronique (ESI) a l'etude de divers systemes multiphasiques: copolymeres bisequences PS/PVP, polyethylenes, caoutchouc naturel renforce par du noir de carbone, IPN constitues de polyurethannes, de polyoxypropene et de PS, melanges de PMMA avec un copolymere greffe PS/POE
Deactivation of the boron–oxygen recombination center in silicon by illumination at elevated temperature

The boron–oxygen‐related recombination center responsible for the light‐induced degradation of solar cells made on boron‐doped oxygen‐contaminated silicon is deactivated by simultaneously annealing the silicon wafer in the temperature range 135–210 °C and illuminating it with white light. The recombination lifetime after deactivation is found to be stable under illumination at room temperature. The deactivation process is shown to be thermally activated with an activation energy of 0.7 eV. Based on the experimental findings, a defect reaction model is proposed explaining the deactivation of the boron–oxygen center. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In vitro studies on antioxidants and free radical scavenging activities in the extracts of Loranthus longiflorus desr. bark samples obtained from two host trees

Antioxidant compounds and their free radical scavenging (FRS) activities in various solvent extracts of Loranthus longiflorus bark samples collected from Casuarina equisetifolia and Ficus religiosa host trees were assessed. The results obtained confirm the presence of total flavonoids, total phenols and total tannins in all extracts at different proportions. Among the extracts tested, ethyl acetate extract shows maximum total phenols (301.25mg/g and 307.27mg/g) and total tannins (11.46mg/g and 204.83mg/g),while chloroform extract favours more amount of flavonoids (18.92mg/g and 26.13mg/g) in Loranthus bark samples collected from the host Casuarina and Ficus, respectively. Among the extracts of Loranthus bark samples, collected from Casuarina and Ficus, ethanol extract shows maximum scavenging activity on DPPH (4681.8% and 4890.6% at 1500µg), on Hydroxyl (49.37% and 55.58% at 250 µg), ethyl acetate (49.79%) and water extract (48.28%) on Nitric oxide (at 250µg) and ethanol (33.71%) chloroform (34.85%) on Superoxide (at 250 µg), respectively, as compared to other extracts. All the FRS activities, tested, were concentration dependent. The inhibitory concentration (IC50) was determined in ethanol extracts as 5. 70µg/ml and 5. 32µg/ml for DPPH-FRS activity; as 34. 34µg/ml and 38.35 µg/ml for HO-FRS activity, as 108. 93µg/ml and 104. 32µg/ml for SO-FRS activity and ethyl acetate extract as 188. 5µg/ml and 116. 1µg/ml for NO-FRS activity of Loranthus bark samples collected from Casuarina and Ficus, respectively, than other extracts, tested. The ferric reducing antioxidant power of Loranthus bark samples, from Casuarina and Ficus hosts, was maximum in ethanol extract (4053.53 and 4199.03mMol Fe (II)/mg extract, respectively) than other extracts tested. These results indicate that the host trees, on which the hemiparasite infested, influence the variations in antioxidant constituents and free radical scavenging activities of L. longiflorus bark extracts.
Surface Electrochemistry: Structured Electrode, Synthesis, and Characterization

1Unite de Pharmacologie Chimique et Genetique et Imagerie, UMR CNRS 8151-U INSERM 1022, Chimie ParisTech and Universite Paris Descartes, 11 rue Pierre et Marie Curie, 75231 Paris, France 2Department of Chemistry, Rhodes University, Grahamstown 6140, South Africa 3Departamento de Quimica de los Materiales, Facultad de Quimica y Bioloǵia, Universidad de Santiago de Chile, Casilla 40, Sucursal Matucana, Santiago 9170022, Chile