Miracle-dz/UniFAR-FTUs huggingface dataset:
Complexation of Palladium(II) with unsaturated Dithioethers a systematic development of highly selective ligands for solvent extraction

There is a demand for new and robust PdII extractants due to growing recycling rates. Chelating dithioethers are promising substances for solvent extraction as they form stable square-planar complexes with PdII. We have modified unsaturated dithioethers, which are known to coordinate PdII, and adapted them to the requirements of industrial practice. The ligands are analogues of 1,2-dithioethene with varying electron-withdrawing backbones and polar end-groups. The crystal structures of several ligands and their palladium complexes were determined as well as their electro- and photochemical properties, complex stability and behaviour in solution. Solvent extraction experiments showed the superiority of some of our ligands over conventionally used extractants in terms of their very fast reaction rates. With highly selective 1,2-bis(2-methoxyethylthio)benzene (4) it is possible to extract PdII from a highly acidic medium in the presence of other base and palladium-group metals.
Growth of SrVO3 thin films by hybrid molecular beam epitaxy

The authors report the growth of stoichiometric SrVO3 thin films on (LaAlO3)0.3(Sr2AlTaO6)0.7 (001) substrates using hybrid molecular beam epitaxy. This growth approach employs a conventional effusion cell to supply elemental A-site Sr and the metalorganic precursor vanadium oxytriisopropoxide (VTIP) to supply vanadium. Oxygen is supplied in its molecular form through a gas inlet. An optimal VTIP:Sr flux ratio has been identified using reflection high-energy electron-diffraction, x-ray diffraction, atomic force microscopy, and scanning transmission electron microscopy, demonstrating stoichiometric SrVO3 films with atomically flat surface morphology. Away from the optimal VTIP:Sr flux, characteristic changes in the crystalline structure and surface morphology of the films were found, enabling identification of the type of nonstoichiometry. For optimal VTIP:Sr flux ratios, high quality SrVO3 thin films were obtained with smallest deviation of the lattice parameter from the ideal value and with atomically sm.
A DESCRIÇÃO MATEMÁTICA DO FENÔMENO OSCILATÓRIO DURANTE A SÍNTESE ELETROQUÍMICA DOS FILMES DOS OXI-HIDROXI COMPOSTOS DE COBALTO (III) E DURANTE A SÍNTESE DOS COMPÓSITOS DELES COM OS POLÍMEROS CONDUTORES

Eclética Química, 37, 72-78, 2012. Esq. 1. As oscilações de corrente, observadas durante a oxidação eletroquímica dos sais de cobalto bivalente (para este caso do sulfato de cobalto heptahidrado) e a dependência da imágem delas da concentração do fluoreto na solução. Os valores da corrente e da freqüência das oscilações cresceram com o aumento da concentração do fluoreto, já que a velocidade da dissolução do filme cresceu. Quando os experimento foi repetido sob os potencias mais altos, a quantidade das oscilações se INTRODUÇÃO
Molecular basis for nucleotide-dependent conformational changes of the large GTPase atlastin

The large GTPase atlastin belongs to the dynamin superfamily that has been widely implicated in facilitating membrane tubulation, fission, and in select cases, fusion. Mutations spread across atlastin isoform 1 (atlastin-1) have been identified in patients suffering from hereditary spastic paraplegia (HSP), a neurodegenerative disorder affecting motor neuron function in the lower extremities. On a molecular level, atlastin-1 associates with high membrane curvature and fusion events at the endoplasmic reticulum and cis-Golgi. Here we report crystal structures of atlastin-1 comprising the G and middle domains in two different conformations. Although the orientation of the middle domain relative to the G domain is different in the two structures, both reveal dimeric assemblies with a common, GDP-bound G domain dimer. In contrast, dimer formation in solution is observed only in the presence of GTP and transition state analogs, similar to other G proteins that are activated by nucleotide-dependent dimerization. Analyses of solution scattering data suggest that upon nucleotide binding, the protein adopts a somewhat extended, dimeric conformation that is reminiscent of one of the two crystal structures. These structural studies suggest a model for nucleotide-dependent regulation of atlastin with implications for membrane fusion. This mechanism is affected in several mutants associated with HSP, providing insights into disease pathogenesis. _______________________ ‡ The following sections are reproduced from: Byrnes, L.J. and Sondermann, H. 2011. Structural basis for the conformational switching and GTP loading of the large G protein atlastin. PNAS. 108(6) pp2216-2221, doi: 10.1073/pnas.1012792108, with modifications to conform to the required format. LJB and HS conceived the project, designed and performed the experiments, analyzed the data, and wrote the paper.
Free energy calculations of the stacked and unstacked states for DNA dimers by replica‐exchange umbrella sampling

We report the free energy difference between the stacked state and unstacked state for DNA dimers. The free energy difference was generated from replica‐exchange umbrella sampling molecular dynamics simulations which allows the simulation to sample much wider conformational space and, therefore, to give more accurate free energy than by the conventional umbrella sampling (US). From the free energy difference, we observed good stacking for all 16 possible DNA dimers and sequence‐dependent stacking stability. This sequence dependence of the stacking free energy is in agreement with the experimental results.
Synthesis, Characterization, and Hydrolytic Degradation of Biodegradable Poly(ether ester)-Urethane Copolymers Based on ε-Caprolactone and Poly(ethylene glycol)

In this article, a new kind of biodegradable poly(e-caprolactone)-poly(ethylene glycol)-poly(e-caprolactone)-based polyurethane (PCEC-U) copolymers were successfully synthesized by melt-polycondensation method from e-caprolactone (e-CL), poly(ethylene glycol) (PEG), 1,4-butanediol (BD), and isophorone diisocyanate (IPDI). The obtained copolymers were characterized by 1H-nuclear magnetic resonance (1H-NMR), FTIR, and gel permeation chromatography (GPC). Thermal properties of PCEC-U copolymers were studied by DSC and TGA/DTG under nitrogen atmosphere. Water absorption and hydrolytic degradation behavior of these copolymers were also investigated. Hydrolytic degradation behavior was studied by weight loss method. 1H-NMR and GPC were also used to characterize the hydrolytic degradation behavior of PCEC-U copolymers. The molecular weight of PCL block and PEG block in soft segment and the content of hard segment strongly affected the water absorption and hydrolytic degradation behavior of PCEC-U copolymers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Theoretical treatment of (M=Cu, Ag and Au)

Quantum chemical calculations of the structure and stability of the series at the CCSD(T) theoretical level have been performed. The role of interaction is investigated using natural bond orbital (NBO) and electron density analyses. Results show that charge transfers from Ar to M2 + and covalent contributions occur in the Ar-M2+ bonding.
Scintillation properties of LYSO crystals

We evaluate the scintillator properties of LYSO (Lu/sub (2-x)/Y/sub x/SiO/sub 5/:Ce) crystals with the amount of lutetium ranging from 15 to 100%. The radii of the cations Lu/sup 3+/ and Y/sup 3+/ differ by only 5%, therefore, one can substitute yttrium for lutetium without changing the structure. The addition of yttrium has several advantages: the raw material Y/sub 2/O/sub 3/ is much cheaper than Lu/sub 2/O/sub 3/ and the melting point is up to 100/spl deg/C less. Since yttrium has a much lower atomic number and atomic mass than lutetium, LYSO crystals have a lower density and effective atomic number. This means that LYSO does not absorb X-rays as well as LSO. LYSO with 50% lutetium, however, has an effective atomic number that is just 11% less than LSO and the light yield of LYSO with 30% or more lutetium is roughly the same as that of LSO samples. LYSO scintillators with 50% or more lutetium could provide a more cost effective scintillator material for some applications.
Generating Particle Beams of Controlled Dimensions and Divergence: II. Experimental Evaluation of Particle Motion in Aerodynamic Lenses and Nozzle Expansions

A particle-beam-forming apparatus for producing narrow particle beams was developed based on the theory discussed in paper I of this series. It consists of a variable number of aerodynamic lenses (short capillaries and/or thin-plate orifices with diameters ranging from 3.5 to 7.0 mm) followed by an accelerating nozzle (3 mm). It was evaluated using monodisperse DOS and NaCl particles (0.02–0.24 μm) at upstream pressures on the order of 1 torr. The particle beams produced by the lens-nozzle system were focused through a skimmer (1 mm) into a high vacuum chamber (10−4–10−5 torr) where the beam widths, velocities and transport efficiencies were measured. The experiments showed that as more lenses were added the particle beam widths were reduced asymptotically to the minimum values. For spherical particles (DOS) these minimum values are in good agreement with the Brownian limit derived in paper I. For nonspherical particles (NaCl) these minimum widths are much larger than the Brownian limit, indicating that b.
The Effect Of Sensitizer Chemistry On Decarboxylation-Type Image Reversal Systems

This paper studies the chemistry of image reversal resists composed of diazonaphthoquinone/novolac resins and varying amounts of aliphatic and aromatic amines. Special emphasis is placed on understanding the mechanism of decarboxylation as impacted by 2,1,4- vs. 2,1,5-diazonaphthoquinone esters. It is shown that the electron-withdrawing effect of the sulfonyl group in the 4- position of the diazo is much stronger compared to the same effect of the same group in the 5- position. The 2,1,4-type resists are therefore more effective in image reversal, requiring lower amine concentrations to be operative. The impact of the weaker electron-withdrawing effect in the 2,1,5-type sensitizer can be compensated for by increasing the concentration of the amine. Higher basicity of the amine allows lower concentrations for satisfactory image reversal performance. Unlike image reversal systems based on acid-catalyzed, heat-induced crosslinking, which tend to favor negative slopes, sidewall profiles of the systems studied here can be controlled from negative, to vertical, to positive, by changing the diazo content of the resist and the PEB temperature. It has also been found that some of the decarboxylation type, image reversal formulations display shelf-life stabilities greater than six months, making them viable production products.
Frequency Response Analysis

Over the last few decades it has been recognized that Frequency Response Analysis (FRA) is a reliable method for detecting dimensional changes in the transformer windings. Out of the two methods of FRA, swept frequency response analysis (SFRA) has gained popularity over the impulse frequency response analysis (IFRA) with the passage of time, although the later was developed first. SFRA is an offline, non-invasive, terminal-based low-voltage measurement, the primary objective of which is to detect even small mechanical deformations accurately. In SFRA the excitation signal of a given frequency is injected to one terminal of the transformer and the response signal is measured at the other end of the winding or at another terminal. Then the transfer function of the winding is computed from the measured excitation and response signals. The frequency of excitation signal is varied over a wide range to detect the deviations in the FRA response, with the help of which the nature of the mechanical fault as well as the quality of insulation could be judged. Frequency dependent parameters of winding such as inductances and capacitances determine the resonant frequencies which appear as peaks and valleys in the FRA transfer functions. Such resonances, which are governed by the poles and zeros of the equivalent network of the transformer winding, appearing in the test case is compared to a no-fault case for identification of fault, if any. There are several comparison techniques that are being used in practice and sometimes more than one technique need to be used simultaneously to arrive at an unambiguous decision. In FRA evaluation processes, it is important to identify the factors that affect the transformer responses in different frequency ranges. There are several terminal configurations of FRA test that may be employed in practice. The sensitivity of the terminal configuration in the detection of mechanical faults is an important issue in FRA. Accurate simulation of FRA response of transformer windings, not only in isolation but also for two-winding transformers, is required for identifying FRA features that could be used for accurate fault identification within an integrated framework. Development of suitable online monitoring system based on SFRA will be helpful in identifying small mechanical faults within transformers in service before such small faults could lead to major faults with severe consequences.
On the application of phase relationships to complex structures. V. Finding the solution

Multisolution direct methods for solving crystal structures lead to many plausible sets of phases and some means of determining the correct set is necessary. For centrosymmetric structures, figures of merit are usually quite discriminating and the examination of only one or two E maps is necessary. For noncentrosymmetric structures, figures of merit are unreliable and the necessity of examining a large number of E maps can sometime prove to be an almost insuperable obstacle to finding the correct structure. A procedure is described for overcoming this difficulty. The Cooley-Tukey fast-Fourier-transform technique is used to compute E maps and all peaks greater than a certain height are located. A selection of the highest of these peaks, whose number is chosen by the program user, is then analysed with respect to bond lengths and angles. Favourable projections of coherent groups of peaks are output on the line printer in the form of integers representing the ranking order of the peaks and in positions which represent an undistorted projection of the group. Computing time is of the order of one minute per set of phases and the examination of a set of 32 maps and finding the correct solution takes about 30 minutes.
ENVIRONMENTAL REMEDIATION USING HORIZONTAL DIRECTIONAL DRILLING: ApPLICATIONS AND MODELING

The use of horizontal directional drilling (HDD) technology in environmental remediation operations is an emerging field. An overview of horizontal environmental well technology, and its use in North America is presented. The advantages and disadvantages of this technology are discussed and three case studies are described. The case studies demonstrate the use of horizontal wells to effectively remediate contaminated soil and ground water. In the future, greater utilization of this technology will likely occur as both the direct installation costs and the risks borne by the contractor decline. This can be partially achieved by the utilization of numerical tools such as modeling and simulation software, which can contribute to reducing uncertainty and increasing productivity. One such application named SEHDDO (simulation environment for horizontal directional drilling operations) is described. When fully developed this computational framework will include a three-dimensional (3D) simulation of well perform.
GREEN ANALYTICAL METHOD FOR THE SENSITIVE DETERMINATION OF MONONITROPHENOL ISOMERS BY DYNAMIC pH JUNCTION CAPILLARY ELECTROPHORESIS

A green analytical method was developed for the sensitive determination of three mononitrophenol isomers by dynamic pH junction capillary electrophoresis. The background electrolyte solution used for enrichment and separation of mononitrophenol isomers were borate solution containing β-cyclodextrin (pH = 9.2). The pH of sample solution was maintained with the addition of a buffer solution of acetic acid/acetate and was kept at 4.5. The other main experimental factors influencing the separation and preconcentration effect were systematically examined, such as the cartridge temperature, injection time, applied voltage, and the amount of β-cyclodextrin in BGE. The relative standard deviations (RSD) of migration times for the three isomers were less than 1.8%, and the RSDs of peak areas were less than 2.3%. The limits of detection (based on signal-to-noise ratio of 3) for the three isomers were within 2.7–8.7 µg · L−1. The recoveries measured were in the range of 92–112% for 2-nitrophenol, 94–108% for 3-nitrophenol, and 94–108% for 4-nitrophenol. The method was applied to the analysis of tap water and fishpond water.
Printed plastic electronics and paperlike displays

Plastic electronic materials and high-resolution printing methods may be important technologies for new classes of consumer electronic devices that are lightweight, mechanically flexible and bendable, and that can cover large areas at low cost. This article summarizes some of our recent work in this area. It focuses on the materials and patterning techniques that we used to produce plastic active-matrix backplane circuits for a type of paperlike display. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3327–3334, 2002
Thermal expansion, heat capacity, and compressibility of solid CO2

The coefficients of thermal expansion (13 to 139 °K), heat capacity (2 to 20 °K), and velocity of longitudinal and transversal ultrasonic waves (88 to 190 °K) for solid CO2 have been determined along the solid-vapour equilibrium line. Heat capacity of constant volume, adiabatic and isothermal compressibilities, the Gruneisen and Poisson coefficients were calculated using the above data. The contributions of various types of heat motion to heat capacity, thermal expansion and compressibility have been separated, and the parameters of isolated orientational defects in crystalline CO2 determined. The connection between the orientational defect parameters and the extent of non-centricity of intermolecular interactions in solids is discussed. Die thermischen Ausdehnungskoeffizienten (13 bis 139 °K), die Warmekapazitat (2 bis 20 °K) und die longitudinale und transversale Ultraschallgeschwindigkeit (88 bis 190°K) wurden fur festes CO2 an der Festkorper-Dampf-Gleichgewichtslinie bestimmt. Mit den erhaltenen Werten wurden die Warmekapazitat bei konstantem Volumen, die adiabatischen und isothermen Kompressibilitaten und die Gruneisen- und Poissonkoeffizienten berechnet. Die Beitrage verschiedener Arten der Warmebewegung zur Warmekapazitat, thermischen Ausdehnung und Kompressibilitat wurden separiert und die Parameter von isolierten Orientierungsdefekten in kristallinem CO2 bestimmt. Die Verbindung zwischen den Parametern der Orientierungsdefekte und dem Ausmas der Nichtzentrizitat von intermolekularen Wechselwirkungen in Festkorpern wird diskutiert.
Supernova Mixtures Reproducing Isotopic Ratios of Presolar Grains

Most of supernova-originating presolar grains, such as silicon carbide type X (SiC X) and low-density graphite, show excesses of 28Si. Some of them also indicate evidence for the original presence of short-lived nuclei 44Ti. In order to reproduce isotopic and elemental signatures of these grains, large-scale heterogeneous mixing in supernova ejecta is required. I investigate supernova mixtures that reproduce as many isotopic ratios as possible of 18 individual SiC X and 26 individual low-density graphite grains. The supernova ejecta are divided into seven layers, i.e., the Ni, Si/S, O/Si, O/Ne, C/O or O/C, He/C, and He/N layers. Then, mixtures indicating isotopic ratios with small differences from those of individual single grains are sought. Mixtures reproducing five isotopic ratios in 12C/13C, 14N/15N, 26Al/ 27Al, 29Si/28Si, 30Si/ 28Si, and 44Ti/48Ti are obtained for three SiC grains. For 10 SiC X grains for which five, four, or three isotopic ratios have been measured, the mixtures reproducing all measured isotopic ratios are also found. For 20 low-density graphite grains, the mixtures reproducing six isotopic ratios in 12C/13C, 14N/ 15N, 16O/17O, 16O/18O, 26Al/27Al, 29Si/28Si, 30Si/28Si, and 44Ti/48Ti are obtained. The mixing ratios of each mixture strongly depend on reproduced isotopic ratios. The main component of most mixtures is one of the Ni, He/C, and He/N layers. The carbon-to-oxygen ratio of the mixtures is larger than unity for most cases. The ratios of Fe/C and Fe/Si in the mixtures have large varieties. Most of the mixtures for low-density graphite indicate Fe/Si larger than unity. The elemental signatures of the mixtures will constrain grain formation in supernovae.
An alternative approach for atmospheric plume deposition and sedimentation

An alternative air pollution model of transport, diffusion, deposition and sedimentation has been formulated for gaseous or suspended particulate pollutants emitted from an elevated point source. The model is obtained by utilizing a continuous distribution of surface sources to replace the image source. It properly describes gradient diffusion to account for the ground deposition and gravitational settling. For practical application of the model to a variety of atmospheric stabilities, the vertical standard deviation parameter σz (x) as a function of downwind distance and stability has been incorporated in the model. The numerical algorithms and the diagrams for facilitating application of the model are present. The model has been tested and applied to particulate pollutants with gravitational settling velocity and to gases which deposit on the ground. Calculated results of concentration at the receptor height and net deposition and suspension ratios with respect to downwind distances are presented.
Radiation-Induced Graft Copolymerization of Metacrylic Acid and Butyl Methacrylate onto Poly(3-hydroxybutyrate)

Abstract Poly(3-hydroxybutyrate) (PHB) is a biocompatible and biodegradable thermoplastic polyester obtained microbiologically. Its main drawbacks are its thermal instability, brittleness, and moderate hydrophobicity, which limit its applications. The present study involves the chemical modification of PHB by means of the synthesis and characterization of graft copolymers with two selected monomers. Typical monomers, methacrylic acid (MA) and butyl methacrylate (BuM), were graft polymerized onto PHB by radiation-induced graft copolymerization reaction to improve PHB's hydrophilicity. The effect of different solvents on the radiation-induced graft copolymerization of the monomers onto poly(3-hydroxybutyrate) was investigated. Structures of the graft copolymers obtained were determined by Fourier transform-infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. Examination of the infrared spectra of the polymeric materials showed that there are no significant changes in their spectra apart from slight changes in the intensities of absorption bands. The results are consistent with the successful grafting of MA and BuM monomer onto PHB. Double melting peaks for grafted PHB were observed, which was probably caused by recrystallization of the graft copolymer. For grafted PHB, the introduction of MA and BuM groups hinders its crystallization, causing a decrease in the degree of crystallinity. The swelling behavior was also studied. The results showed that water uptake significantly increased. Hence, such a grafting process improved the hydrophilic character of PHB. The possibility of using these grafted polymers in practical biomedical applications is promising.