Miracle-dz/UniFAR-FTUs huggingface dataset:
cis‐5‐Bromo‐2,2,6‐trimethyl‐trans‐6‐phenyltetra­hydro­pyran‐3‐carboxylic acid

Centrosymmetric hydrogen-bonding between carb­oxy substituents links enanti­omers of the title compound, C15H19BrO3, into dimers. Close contacts that originate from axially arranged methyl substituents in positions 2 and 6 induce distortions, which are evident from a widening of the endocyclic bond angle at the ring O atom [122.6 (6)°] and a flattening of the tetra­hydro­pyran chair.
Brownian Dynamics Simulation of Biased Sinusoidal Field Gel Electrophoresis

Brownian dynamics simulation of DNA in the biased sinusoidal field gel electrophoresis was performed. The time development of the velocity of the center of mass and the principal value of the gyration tensor was measured as a function of the chain length and the frequency of the applied field. It is found that (i) for short chains N Nc(E), the mean migration velocity shows local minimum and local maximum at characteristic frequencies f1 and f2, respectively. These results are in agreement with the experiment of Shikata et al. Analysis of the data indicates that the DNA takes the stretched V-conformation and compact conformation alternatively, while at the frequency f1 the DNA frequently takes the W-conformation.
Methanol transport through Nafion membranes : Electro-osmotic drag effects on potential step measurements

This paper describes methanol flux measurements across Nafion, 1100 equivalent weight membranes under conditions of a direct methanol fuel cell but in which methanol is completely electro-oxidized on the opposite side in an inert atmosphere at sufficiently high electrode potential. Both the diffusion coefficient and the methanol concentration in the membrane were determined from the measured transient limiting current density following a potential step. Corrections for electro-osmotic drag effects are developed and found necessary even for low MeOH concentrations. The results agree well with those obtained from nuclear magnetic resonance measurements. The partition coefficient [{rho} = [MeOH]{sub membrane}/[MeOH]{sub solution}] was approximately constant for the membranes in contact with methanol solutions of various concentration and from room temperature to 90 C. The activation energy of methanol diffusion in a fully hydrated Nafion membrane between 30 and 130 C is 4.8 kcal/mol, and that for protonic conduction under the same conditions is 2.3 kcal/mol. For a membrane dried in vacuum at above 100 C, lower values of methanol permeation rate and protonic conductance were found.
Contrast enhancement and depth perception in three‐dimensional representations of differential interference contrast and confocal scanning laser microscope images

A commonly used three‐dimensional reconstruction method in confocal scanning laser microscopy (CSLM) involves the generation of stereo views by stacking optical sections. Under certain conditions the resulting stereo pairs exhibit inferior quality with respect to contrast and depth perception. A method based on digital image processing is described in which the individual images are enhanced prior to reconstruction, thereby increasing the number of usable optical sections by a factor of up to five. Furthermore, we introduce a new contrast enhancement transformation based upon local statistics and a grey‐level probability density function that provides improved depth perception. Digital image processing methods map a discrete grey scale onto a continuous, unbounded interval. Inasmuch as a closed, discrete grey scale is required for computer display purposes, we present an appropriate mapping function derived from an entropy criterion.
Electron‐beam‐generated carrier distributions in semiconductor multilayer structures

The electron beam of a scanning electron microscope causes carrier generation in a semiconductor and these carriers are the probe for various types of image. In particular, the electron‐beam‐induced current mode gives images which reveal electrically active near‐surface defects in a semiconductor sample. Since semiconductor multilayer structures are now very common, one needs to know how the multilayer structure modifies the shape of the generation volume. The Monte Carlo technique for modelling beam electron trajectories inside the sample is used and gives a detailed insight into the shape of such a generated carrier generation distribution. Additionally, a simpler analytical method is developed for constructing a one‐dimensional depth distribution for multilayer structures, starting from known depth dose distributions for bulk materials. The analytical method is validated by comparison with Monte Carlo results.
Distortion of Host Lattice in Clathrate Hydrate as a Function of Guest Molecule and Temperature

Neutron powder diffraction data of deuterated clathrate hydrates of carbon dioxide and xenon were measured in order to investigate the effects of the motion of guest molecules on the structure of the surrounding hydrogen-bonded network. Rietveld analysis revealed that the magnitude of the thermal parameters of the host atoms of the CO2 clathrate hydrate depends strongly on the crystallographic site, while those of the Xe clathrate hydrate do not depend on the site. The host lattice structure of the Xe clathrate hydrate may be a close representation of the hypothetical empty clathrate hydrate, because of the simple spherical shape of the Xe molecule. The site dependence of the thermal parameters of the host atoms in the CO2 clathrate hydrate are attributed to the motion of the CO2 molecules in the cages. The CO2 molecule rotates anisotropically about the symmetry axis inside the tetrakaidecahedral cage. We suppose that the surrounding deuterium atoms are temporarily attracted and released by the oxygen ato.
Properties of the JET 130kV/60A positive ion neutral injector

As part of the upgrade to the JET neutral beam heating system a new positive ion neutral injector (PINI) design has been commissioned. The new PINI delivers 60A total beam current at 130kV, approximately doubling the neutral beam power delivered to JET. A programme of testing on the Neutral Beam Test Bed established the preferred geometry to maintain horizontal and vertical beam focal lengths of 10m and 14m respectively. The results of these tests and the characterisation of the beam using a number of diagnostic techniques are described, together with predictions for neutral power delivery to the JET plasma.
Molecular mechanism for analgesia involving specific antagonism of α9α10 nicotinic acetylcholine receptors

α9α10 nicotinic acetylcholine receptors (nAChRs) have been identified in a variety of tissues including lymphocytes and dorsal root ganglia; except in the case of the auditory system, the function of α9α10 nAChRs is not known. Here we show that selective block (rather than stimulation) of α9α10 nAChRs is analgesic in an animal model of nerve injury pain. In addition, blockade of this nAChR subtype reduces the number of choline acetyltransferase-positive cells, macrophages, and lymphocytes at the site of injury. Chronic neuropathic pain is estimated to affect up to 8% of the world's population; the numerous analgesic compounds currently available are largely ineffective and act through a small number of pharmacological mechanisms. Our findings not only suggest a molecular mechanism for the treatment of neuropathic pain but also demonstrate the involvement of α9α10 nAChRs in the pathophysiology of peripheral nerve injury.
Flavonoids and a neolignan glucoside from Guarea macrophylla (Meliaceae)

This work describes the phytochemical study of the methanol extract obtained from leaves of Guarea macrophylla, leading to the isolation and identification of three flavonoid glycosides (quercetin 3-O-β-D-glucopyranoside, quercetin 3-O-b-D-galactopyranoside, kaempferol 7-O-β-D-glucopyranoside) and a neolignan glucoside, dehydrodiconiferyl alcohol-4-β-D-glucoside. All compounds were identified by a combination of spectroscopic methods (1H, 1D, 2D NMR, 13C and UV), ESI-MS and comparison with the literature data. This is the first report of flavonoids in the genus Guarea and of a neolignan glucoside in the Meliaceae family.
Blocking Inhibitors in Cathodic Leveling II. Experimental Investigation

A model for cathodic leveling based on a diffusion-adsorption-reduction mechanism for the leveling agent was tested experimentally by electrodepositing nickel into a semicircular groove in the presence of coumarin. The inhibition of nickel by coumarin was measured on a rotating disk electrode, and kinetics for the reduction of coumarin and Langmuir adsorption coefficient were obtained from polarization data. Satisfactory agreement was found between experimentally measured and simulated leveling for groove depths on the order of the diffusion layer thickness or smaller.
Prebiotically relevant mixed fatty acid vesicles support anionic solute encapsulation and photochemically catalyzed trans-membrane charge transport

The spontaneous assembly of amphiphile-based compartments in aqueous solution is widely viewed as a key step in models for the abiotic formation of primitive cell-like structures. Proposed organic components for such systems consist of mixed short chain fatty acids (FA) and polycyclic aromatic hydrocarbon (PAH) species, the composition of which have been modeled after organic extracts of carbonaceous meteorites. Self-assembly of amphiphiles from these extracts into aqueous suspensions of bilayer structures was long ago demonstrated, although little has since been reported concerning the stability and potential functionality of these complex mixtures. This work explores the thermodynamic and kinetic stability of vesicles prepared from complex mixtures of short chain FA species (CH3COOH–C9H19COOH) with membrane solubilized PAH species. Critical vesicle concentration measurements and ultrafiltration analyses of decanoic acid in the presence of other shorter chain FA species indicate the formation of mixed component vesicle phases composed mainly of C10–C8 FA components. An electrostatic barrier to trans-membrane diffusion of negative charges allows observation of stably encapsulated poly-anionic solutes inside these vesicles. As a model for primitive energy transduction, trans-membrane electron transfer between EDTA and encapsulated ferricyanide was demonstrated, driven catalytically via PAH photochemistry without substantial decomposition of the chromophores or vesicles. These results indicate a plausible role for compartmentalization and catalysis by short chain fatty acids and PAH species in prebiotic vesicle-encapsulated systems.
Nonlinear electron transport properties and rectification effects in InAs/AlGaSb ballistic devices

The nonlinear electron transport properties and rectification effects in InAs/AlGaSb ballistic devices are reported. We fabricated InAs/AlGaSb three-terminal ballistic junction devices composed of three quantum wires, and characterised electron transport properties with scanning the voltage on the left branch while keeping the voltage on the right constant at 77 K and 300 K. In these structures, we observed clear nonlinearity in the output voltage measured at the central branch. The nonlinear characteristics agreed well with a theoretical prediction. When the left branch is biased to a finite voltage V and the right to a voltage of –V (push-pull fashion), negative voltages appeared at the central branch regardless of the polarity of V. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermoelectric Properties of Iron-and Lanthanum-Doped Cosb3 Compounds by Pulse Discharge Sintering

of fossil fuels. In this regard, thermoelectric power generation that can directly convert the thermal energy to electrical energy is one of the attractive methods. Skutterudite compounds of CoSb3 have been investigated as promising candidate materials for thermoelectric power generation. In this research, CoSb3 compounds were synthesized from raw metal powders by using a pulse discharge sintering process. To improve the thermoelectric properties, iron was doped as an element substituting for cobalt of the CoSb3 compound. The syntheses of FexCo1xSb3 were confirmed by x-ray diffraction analysis. The Seebeck coefficient, electric resistivity, and thermal conductivity were measured as the thermoelectric properties. Optimum content of iron was decided from the maximum thermoelectric figure of merit. Furthermore, filling of lanthanum into Fe0:1Co0:9Sb3 was attempted to decreasethethermalconductivity.Thelanthanum-filledFe0:1Co0:9Sb3 compoundsweresynthesizedfromrawmetal powders and LaSb powder by the pulse discharge sintering process. The optimum lanthanum content that leads to the maximum thermoelectric performance is discussed. The substitution of iron for cobalt improved the thermoelectric performance. The lanthanum-filling decreased the thermal conductivity at a low lanthanum content and led to higher thermoelectric performance in spite of low lanthanum content.
Carbon as Reference for Normalizing Infrared Photoacoustic Spectra

Abstract Photoacoustic spectra of solids1 are usually “source compensated,” i. e. , normalized for differences in source emission at different wavelengths, and such compensation is done by comparing the photoacoustic spectrum of a sample to the emission spectrum of the source measured directly with, say, a photocell,2 power meter,3 or photodiode,4 or to the photoacoustic spectrum of “carbon” recorded under the same conditions as that of the sample. A variety of carbons has been used for this purpose, including carbon black on silica,5 soot from a gas torch,6 and acatylene-sooted bakelite,7 such a reference substance being assumed to be a flat black absorber. That assumption appears to be valid, as indicated by the close
On Sensitivity of Spectral Radiative Fluxes to Atmospheric Water Vapor in the 940 nm Region (Numerical Simulation)

Water vapor is well known to be a critical component in many aspects of atmospheric research, such as radiative transfer and cloud and aerosol processes. This requires both improved measurements of the columnar water vapor and its profiles in the atmosphere in a wide range of conditions, and adjustment of water vapor parameterizations in radiation codes including the perfection of spectroscopic parameters. In this paper we will present the results of comparison of our calculations and downward solar fluxes measured with Rotating Shadowband Spectroradiometer under conditions of horizontally homogeneous clouds. We also will discuss the sensitivity of atmospheric radiation characteristics to variations of water vapor in the band 940 nm: these results may be useful for development of new methods of retrieval of the total column water vapor content (WVC) in the atmosphere from data of radiation observations.
Effect of Molecular Properties of Block Copolymers and Nanoparticles on the Morphology of Self-Assembled Bulk Nanocomposites

Self-assembly of thiol-terminated polystyrene-tethered Au nanoparticles in microphase-separated diblock copolymers composed of poly(styrene-b-2vinylpyridine) (PS−PVP) as a function of particle concentration and composition of block copolymers was investigated using anomalous small-angle X-ray scattering (ASAXS) and transmission electron microscopy (TEM). Results reveal that the self-assembly of nanoparticles in the PS domain causes swelling and increases the interfacial curvature that, in turn, induces order−order transitions. At intermediate loading, the presence of nanoparticles amplifies the local compositional fluctuations, hence the roughness at the PS and PVP interface, which creates conditions to induce disorder in the polymer morphology. The system thus undergoes an order−disorder transition. At high particle loading, packing constraints prevent all particles from assembling in the PS domain, and the excess nanoparticles undergo macrophase separation. The present systematic study augments experime.
Effect of POSS-NH2 functionalization of MWNTs on reinforcing properties in epoxy nanocomposites

The research focuses on multiwalled carbon nanotubes (MWNTs) functionalization with aminoethyl aminopropyl polyhedral oligomeric silsesquioxane to increase their compatibility with epoxy polymers and enhancement of interface adhesion. Functionalization of MWNTs consisted of a three-stage reaction by oxidation and further amidation through acylation with thionyl chloride. The new nanomaterials were dispersed as reinforcing agent in a weight ratio of 0.3% related to the epoxy matrix, which was further cured with an aromatic polyamine. Characterization of functionalized MWNTs by infrared spectroscopy revealed the presence of POSS cages bonded to the MWNTs through the formation of amide groups, these findings were also proved by transmission electron microscopic images. Although catalytic influence of the reinforcing agent on the curing reaction was not significant at this level of reinforcement, scanning electron microscopic images of the nanocomposites fracture surface revealed strong interfacial adhesion and crack retardant effect of POSS-functionalized MWNTs.
Progress in new semiconductor materials classes for solar photoelectrolysis

For several decades, the main body of research in photoelectrochemical (PEC) hydrogen production has centered on a small number of semiconductor materials classes, including stable but inefficient metal‐oxides, as well as some more efficient materials such as III–V compounds which suffer from high cost and poor stability. While demonstrating some limited success in meeting the rigorous PEC demands in terms of bandgap, optical absorption, band‐edge alignment, surface energetics, surface kinetics, stability, manufacturability and cost, none of the ‘traditional’ PEC semiconductors are adequate for application in water‐splitting devices with high performance (greater than 15% solar‐to‐hydrogen conversion) and long durability (greater than 200 h life). As a result, it is widely held that new semiconductor classes and configurations need to be identified and developed specifically for practical implementation of solar water‐splitting. Examples include ternary and quaternary metal‐oxide compounds, as well as non‐oxide semiconductor materials, such as silicon‐carbide and the copper‐chalcopyrites. This paper describes recent progress at the University of Hawaii to develop improved semiconductor absorbers and interfaces for solar photoelectrolysis based on polycrystalline tungsten trioxide and polycrystalline copper‐gallium‐diselenide. Specific advantages and disadvantages of both materials classes in terms of meeting long‐term PEC hydrogen production goals are detailed. Copyright © 2010 John Wiley & Sons, Ltd.
Synthesis of hydrocarbons from dimethyl ether : Selectivities towards light hydrocarbons

ABSTRACT The depleting supplies of non-renewable petroleum reserves, as well as their escalating costs, have directed a great deal of research toward the synthesis of hydrocarbons from coal. Synthesis of methanol from coal-derived synthesis gas is a well established technology, and methanol has been used as a feedstock for the synthesis of gasoline range hydrocarbons and olefins commercially. However, an efficient hydrocarbon synthesis process has been developed at the University of Akron using dimethyl ether as the starting feedstock. This UA/ EPRI' s DTH ( Dimethyl Ether to Hydrocarbons) process has significant advantages over its counterpart methanol conversion process in the areas of heat duties, hydrocarbon selectivities, product yield, and reactor size Lower olefins are the intermediate products in the conversion of dimethyl ether to aromatic hydrocarbons. C2-C4 olefins and paraffins can be selectively produced by varying the operating parameters of the process, viz., temperature, pressure, DME conc.
Open source scanning probe microscopy control software package GXSM

GXSM is a full featured and modern scanning probe microscopy (SPM) software. It can be used for powerful multidimensional image/data processing, analysis, and visualization. Connected to an instrument, it is operating many different flavors of SPM, e.g., scanning tunneling microscopy and atomic force microscopy or, in general, two-dimensional multichannel data acquisition instruments. The GXSM core can handle different data types, e.g., integer and floating point numbers. An easily extendable plug-in architecture provides many image analysis and manipulation functions. A digital signal processor subsystem runs the feedback loop, generates the scanning signals, and acquires the data during SPM measurements. The programmable GXSM vector probe engine performs virtually any thinkable spectroscopy and manipulation task, such as scanning tunneling spectroscopy or tip formation. The GXSM software is released under the GNU general public license and can be obtained via the internet.
Modeling of the droplet field in near-horizontal low liquid loading flows

As part of the development of the LedaFlow multiphase simulation tool, experiments have been performed to investigate detailed flux- and velocity profiles in two-phase flows with Nitrogen and Naphtha. The experiments have been recorded in an 8 inch diameter pipe with 0.5° inclination at 20 and 90 bar pressure. Results and implications from these measurements are discussed. Next, a detailed model for droplet entrainment is presented. The experimental data is analysed based on the proposed model framework and the model is calibrated using the available measurements. The subsequent results are discussed.
Liquid-Liquid Equilibrium for (Water + Palm Oil Biodiesel + Methanol) Ternary System at Different Temperatures

The liquid-liquid equilibrium (LLE) of ternary mixtures (water + palm oil biodiesel + methanol) was measured under atmospheric pressure and temperatures of 303.15K, 313.15K and 323.15K. The mutual solubility of biodiesel and water increased as the increasing of ratio of methanol. Also, the mutual dissolution of the mixture was slightly promoted by increasing temperature. The phase diagrams and tie lines for the ternary system were determined by high-temperature gas chromatography (HTGC). NRTL and UINQUAC models were applied to fit the experimental data for the ternary system, and the binary interaction parameters were obtained by regression on the experimental data. Both models could describe the LLE behavior of the systems fairly well.
Solvent and molecular weight effects on fluorescence emission of MEH-PPV

Here we systematically studied the excitation and the fluorescence steady-state spectroscopy of poly(2-methoxy-5(2'-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV) with three molecular weights, Mn= 51 kg mol-1, Mn= 86 kg mol-1 and Mn= 125 kg mol-1, in two equally good solvents and several concentrations, from dilute solutions to solid-state films produced by casting. The appropriateness of the two solvents was established by comparing their solubility parameters and the solubility parameter of the MEH-PPV estimated using the Small, the Van Krevelen and the Hoy models. Thus, chloroform and toluene were chosen. Fluorescence spectra were recorded for solutions in several concentrations (10-8 mol L-1 to 10-4 mol L-1) and films produced by casting, showing that chloroform and toluene solvate the polymer chain differently. Diluted solutions (10-8 mol L-1) in chloroform exhibit broader fluorescence spectra. A red-shift of the fluorescence spectra was observed for concentrations higher than 10-6 mol L-1 that can be explained using Kasha's rule for the sandwich anti-parallel orientation of the transition moments of the two chromophores. The conformations observed in solutions are partially retained in the solid films in addition to the broader red-shift spectra attributed to aggregated forms of the macromolecular segments. Annealing of the polymer films at the glass transition temperature eliminates the more stressed conformations, erases the memory and leads to sharper fluorescence spectra.