Miracle-dz/UniFAR-FTUs huggingface dataset:
Exploration of deep eutectic solvent‐based mesoporous silica spheres as high‐performance size exclusion chromatography packing materials

Choline chloride (ChCl) with three alcohol-based deep eutectic solvents (DESs) was applied as a new type of green solvent for the modification of mesoporous silica spheres. The mesoporous silica spheres were characterized by field emission scanning electron microscopy and Brunauer–Emmett–Teller surface area analysis. Many uniform and mesoporous silica spheres were obtained with a ChCl–1,2-butanediol DES as a reactant. The DES-modified mesoporous silica spheres were used for the adsorption of polysaccharides (alginic acid, fucoidan, and laminarin). The adsorption results show that the ChCl–1,2-butanediol DES-based silica spheres had stable interactions with the target compounds. A comparison of the three sorbents as size exclusion chromatography packing materials showed that the ChCl–1,2-butanediol DES-based silica spheres produced good resolution of the three test polysaccharides and exhibited the best separation capability. This was attributed to the uniform mesoporous structure of the ChCl–1,2-butanediol DES-based silica spheres. Therefore, more DESs should be applied to the preparation of mesoporous silica spheres in future studies. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42203.
1,2‐Bis[2‐n‐butyl‐5‐(2,2‐dicyanovinyl)‐3‐thienyl]‐3,3,4,4,5,5‐hexafluorocyclopent‐1‐ene: a new photochromic diarylethene compound

In the title compound, C29H22F6N4S2, a new symmetric photochromic dithienylethene, the distance between the two reactive C atoms in the mol­ecule is 3.475 (3) A. The dihedral angles between the central cyclo­pentene ring and the two thio­phene rings are 57.9 (1) and 51.2 (1)°. The molecule has no imposed crystallographic symmetry.
Imaging Particulate Two-Phase Flow in Liquid Suspensions with Electric Impedance Tomography

Different approaches have been followed to model the hydraulic transport of particles, ranging from pure empirical correlations to general models based on fundamental principles. However, these models suffer from uncertainties associated with the parameters in the constitutive equations and scarcity of experimental data in the literature. Nonintrusive techniques such as electric impedance tomography (EIT) can be used to circumvent the difficulties associated with sampling techniques. EIT is an imaging technique for the phase distribution in a two-phase flow field, allowing reconstructing the resistivity/conductivity distribution gradients from electrical data in a medium subjected to arbitrary excitations. Our best efforts were concentrated on the development of a new EIT system that is analogue based, portable, low-cost, and capable of providing high-quality sharp images when used to characterize the flow of particle suspensions. A voltage source was used, rather than a more complex and costly current source, since it provided the EIT system with a more precise and flexible current output. The data acquisition system consists of 16 electrodes equally spaced in the boundary of a tube and a custom dedicated electronic apparatus. The software supplies results in the form of two-dimensional reconstructed images that allow mapping the phase distribution inside the tube.
Molecular imprint based radioassay for direct determination of S-propranolol in human plasma

Molecular imprints of S-propranolol have been applied to the development of a radiolabelled assay, which is conceptually identical to radioimmunoassay, for direct determination of the concentration of S-propranolol in biofluids. Determination of S-propranolol in human plasma and urine was used as a model system. The imprint based assay measured plasma and urine concentrations in the range of 20 to 1000 nM with accuracies of 89–107% and 91–125%, and precisions of 3–13% and 1–7%, respectively. The results demonstrate that it is possible to carry out molecular imprint based assays of biological samples without prior sample clean up.
THE HELIX-TURN-HELIX AS A SCAFFOLD FOR CHIMERIC NUCLEASE DESIGN

ABSTRACT De novo design is a powerful tool to investigate the active site of enzymatic metalloproteins, in a smaller, defined model system. It is also a way to build or combine activity and selectivity in unique ways, not seen biologically. We are utilizing protein design to build artificial endonucleases, and to investigate fundamental questions of metallonuclease structure and function. We have focused on designing peptide constructs comprising geometrically similar turns from unrelated proteins, in particular the Ca-binding EF-hand motif of calmodulin and the helix-turn-helix motif (HTH) of engrailed homeodomain. By substituting the calcium-binding (and thus lanthanide-binding) loop in place of the “turn” of engrailed HTH, hydrolytically active, DNA-binding constructs were created. The NMR solution structure of one La-binding chimera (P3W), calculated based on NOE volume integrals, demonstrated that the 33-mer peptide retains the parental helix-turn-helix structure when bound to lanthanide ions. The binding affinities of the chimeras for Ln(III) ions are in the low µM regime, typical for EF-hand sequences, despite the significant changes in flanking sequence. Importantly, the Ln(III) chimeras are catalytically competent, able to hydrolyze phosphate esters including DNA, and were found to bind and cleave DNA with sequence preference. Thus, these designed HTH/EF-hand chimeras represent the first examples of small peptidic artificial nuclease with sequence discrimination, and show that the HTH is a robust scaffold on which to build novel metallopeptide constructs. This review describes the design and characterization of Ln-binding HTH/EF-hand chimeras.
Thermo-mechanical and dielectric properties of graphene reinforced caprolactam cardanol based benzoxazine–epoxy nanocomposites

In the present work a new type of benzoxazine was synthesized using caproamine with cardanol and the molecular structure was characterized by FTIR and NMR spectroscopy. The graphene reinforced epoxy–polybenzoxazine nanocomposites were prepared by incorporating varying weight percentages of graphene and benzoxazine to an epoxy resin. Data obtained from the mechanical study infer the significant improvement in the values of tensile strength, impact strength and flexural strength of the composites reinforced with different weight percentages of benzoxazine and graphene. The values of the dielectric constant of the composite samples are appreciably enhanced and are higher than that of the neat epoxy matrix. Data from SEM, TEM and XRD ascertain the existence of homogeneous distribution of graphene in the composites. Data obtained from thermal, mechanical, dielectric and surface free energy studies infer that 20 wt% Bz–g reinforced composites possess better properties than those of the neat epoxy matrix and other weight percentages of composites.
Multidimensional modeling of turbulent two‐phase flows in stirred vessels

This article outlines a computational procedure for the prediction of dispersed two-phase, solid-liquid and gas-liquid, turbulent flows in baffled, impeller-stirred vessles common in the chemical industries. A two-flow Eulerian model is employed, based on the main assumption of interpenetrating coexisting continua. Mean momentum and mass conservation equations are solved for each phase and turbulent closure is effected by extending the single phase k- epsilon turbulence model to two-phase flows. The resulting set of highly coupled equations is solved by a two-phase implicit algorithm, PISO-2P, which allows calculation for a wide range of phase fraction, particle size and phase density ratios. Predictions are presented for solid-liquid and gas-liquid (bubbly) flows. Comparisons are made with experimental data for the mean phase velocities and volume fraction, mean slip velocity and turbulence quantities. (from Authors)
Photocure Reactions of Photoreactive Prepolymers with Cinnamate Groups

The photoreactive prepolymers with multifunctional cinnamate and bisphenol Atype cinnamate groups that could perform photodimerization without photoinitiators were synthesized by the reaction of t-cinnamic acids (CAs) and epoxy resins. Their photocure reaction rates and the extent of reaction conversion were measured with Fourier transform infrared spectroscopy,and these increased with the intensityof UVirradiation.The experimental data of these reaction rates showed the characteristics ofnth-orderkinetics reaction,and allkinetic constants of each photoreactive polymer with this equation were summarized. Although the GTR-1800-HCAand KWG1-EP-HCAwith hydroxyl group substituted cinnamate showed lower reaction conversion rates and rate constant than GTR-1800-CA and KWG1-EP-CAwith an unsubstituted cinnamate group,GTR-1800-MCAand KWG1-EP-MCAwith methoxygroup substituted cinnamateshowedsimilarand higherreactionconversionrates than theformer,respectively.Theseresults were explained in terms of segmental mobility for photopolymerization by molecular interactions.
Capillary Electrophoresis of Gliadins as a Tool in the Discrimination and Characterization of Hulled Wheats (Triticum dicoccon Schrank and T. spelta L.)

ABSTRACT Twenty-two lines of emmer (T. dicoccon Schrank) and 10 of spelt (T. spelta L.) were analyzed using capillary electrophoresis for their gliadins. These proteins were separated on an uncoated fused-silica capillary (30 cm long, 22 cm to detector, 50 μm i.d.) using the isoelectric buffer 40 mM aspartic acid, 4M urea, 0.5% (w/v) HEC, and 20% (v/v) acetonitrile. Samples were run for 20 min at 22kV and 42°C. By using these conditions, gliadins were separated into 21–30 components (peaks and shoulders). The major peaks eluted between 4.5 and 8.5 min. Electrophoregrams of tested lines showed qualitative and quantitative differences, including number of peaks, presence or absence of some major peaks, and areas of peaks. Lines belonging to the same species can be discriminated mainly on the basis of β- and ω-gliadin patterns. The γ-and ω-gliadins seem to be more useful in the differentiation of emmer from spelt. The comparison of electrophoregrams relative to hulled and unhulled species evidenced the high .
Rechargeable hydrogen storage in nanostructured mixtures of hydrogenated carbon and lithium hydride

A hydrogen storage ability caused by the interaction between nanostructured carbon (CnanoHx) and lithium hydride (LiH) is demonstrated, which should be recognized as Li-C-H system in the H-storage materials. Especially, the 2:1 mixture of CnanoHx and LiH exhibited promising hydrogen storage properties with a rechargeable hydrogen capacity of more than 4 mass% below 350 °C, preserving the nanostructural feature in the mixture even after hydrogen release. On the other hand, the 1:2 and 1:1 mixtures exhibited the crystal growth of Li2C2 after hydrogen desorption, leading to poorer hydrogen rechargeability.
Numerical simulation of Trichel pulses in low pressure oxygen

The development of Trichel pulses in sphere-to-plane geometry is investigated by means of one-dimensional discharge model with the electric field computed in two dimensions. The train of pulses is triggered by the release of a number of free electrons in the vicinity of the cathode. In addition, a weak uniform background ionization is taken into account in the gas. The discharge is assumed to advance between the sphere and the plate along the axis of symmetry. Secondary electrons are created at the cathode by the impact of positive ions and by photoionization. In the bulk of the gas, ionization of neutral molecules, electron attachment and recombination have been considered as well.
What does the HOMA index really measure

The HOMA index was generalized to the function of a property of chemical bonds such as, e.g., characteristics in BCPs. The new HOMA indices strongly correlate with the classical one for a variety of cyclic hydrocarbons unsaturated or not. Thus, the indices reflect a more general property then aromaticity: the savoricity.
Search for the best processes to liquefy hydrogen in very large plants.

The goal of the IDEALHY project is to identify processes and components, which allow liquefying hydrogen with a power consumption much lower than with plants built so far. This requires comparing different possible processes concerning power efficiency, investment cost and compactness. The power consumption of a process depends on a number of boundary conditions. Without a clear overall definition of these boundary conditions, all statements and comparisons on the overall power consumption are questionable. So in the first step of the project the participants agreed on common boundary conditions. Then it turned out, that the choice of the high pressure of the feed hydrogen influences strongly the rest of the liquefaction process, especially the region below 80 K. For this region there is an option between helium, hydrogen and neon as refrigerants and their mixtures. For the final choice of the working fluid and the process one has to identify the maximum possible circumferential speed of turbo compressors.
Biogenic flower-shaped Au–Pd nanoparticles: synthesis, SERS detection and catalysis towards benzyl alcohol oxidation

∼40 nm flower-shaped Au–Pd bimetallic nanoparticles were prepared in a facile and eco-friendly way based on the simultaneous bioreduction of HAuCl4 and Na2PdCl4 with ascorbic acid and Cacumen Platycladi leaf extract at room temperature. Characterization techniques, such as transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction, were employed to confirm that the as-synthesized nanoparticles were alloys. The obtained flower-shaped Au–Pd alloy nanoparticles exhibited an excellent surface enhanced Raman spectroscopic activity with rhodamine 6G and efficient catalytic ability for the oxidation of benzyl alcohol to benzaldehyde.
Bifunctional benzoxazines: Synthesis and polymerization of resorcinol based single isomers

Aside from their outstanding properties such as thermal and chemical stability and excellent mechanical performance, benzoxazines suffer from high polymerization temperatures. Isomeric mixtures of bifunctional benzoxazines based on resorcinol proved already to be highly reactive monomers enabling polymerizations at lower temperatures. This contribution describes the polymerization behavior of single benzoxazine isomers and furthermore the influence of different substituents at the aniline moiety on the curing temperature. Single isomers of bifunctional benzoxazines are now accessible in a straightforward one-pot synthesis starting from resorcinol and the appropriate N-phenyl functionalized aniline component. The asymmetric benzoxazine monomers bearing no (R-a: Tpeak = 179 °C) or electron-donating substituents in meta position to N (R-3,5dma: Tpeak = 183 °C) succeed in lowering the polymerization temperature. Additionally, the impact of several initiating systems was studied resulting in a decrease of the polymerization temperature for all studied resorcinol derived benzoxazine isomers (down to 144 °C). © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015
How to Motivate Students to Study before They Enter the Lab.

Laboratory exercises constitute an important part of chemical and biochemical courses at the university level. Nevertheless, students frequently are insufficiently prepared for the practical work, which often reduces their work to the level of a technician. A system designed to motivate students to study prior to the laboratory exercise was introduced. Initial sessions and preliminary tests were held prior to the exercises. As a consequence students studied more before the exercise than in the previous system. The time burden for students was not considerably increased, since the reports were shortened and written immediately after the exercise. Communication between students and teaching assistants, which was also a weak point of the previous system, improved. Students performed significantly better on the final exam and exhibited a positive attitude towards the changes.
Liquid Adsorption Chromatography near Critical Conditions of Adsorption Coupled with Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry

Abstract Chemical heterogeneities and molecular weight distributions of poly(ethylene oxide) (PEO)-co-polymethylene (PM) model oligomers, which are relevant to the synthesis of commonly used tensides, were investigated. For analytical characterization, the well-known principle of liquid adsorption chromatography at ‘critical conditions’ (LACCC) was modified. Near the critical conditions of adsorption of the PEO unit, e.g., at slight adsorption conditions of PM, the copolymers could be separated according to their PM chain length. The eluates were separated and single fractions of each peak were continuously transferred onto the MALDI target by means of a commercially available device. Simultaneously, the MALDI matrix solution was continuously added with a second pump. This procedure offers the possibility of the formation of homogeneous matrix-polymer textures. By MALDI-MS a complete characterization of the chemical composition (PEO and PM chain length) of each peak could be achieved. The obtained MALDI mass spectra of the eluates at different retention times could be used for the molecular weight calibration of the LAC system. In this way, an additional application of SEC, as in conventional 2D-chromatography, was avoided by using the MALDI method as quasi chromatographic separation.
Integration of sustainable energy sources through power electronic converters in small distributed electricity generation systems

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Cloud point extraction for preconcentration of trace beryllium and chromium in water samples prior to electrothermal atomic absorption spectrometry

In the present work, a simple, sensitive method was developed for the determination of beryllium and chromium by electrothermal atomic absorption spectrometry (ETAAS) after simultaneous pre-concentration by cloud point extraction (CPE). The procedure was based on the formation of the hydrophobic chelates of Be and Cr(III) and/or Cr(VI) with cupferron, followed by their quantitative extraction into the surfactant-rich phase by the Triton X-114. The effects of the main parameters affecting the extraction recovery of CPE, such as pH of the sample solution, concentration of the chelating agent and surfactant, equilibration temperature and incubation time, were investigated and optimised. Under the optimal experimental conditions, the limits of detection and limits of quantification for Be were 0.33 and 1.11 pg and for Cr(VI) were 0.98 and 3.28 pg, respectively. The pre-concentration factor for Be and Cr(VI) was found to be 20 for 10 mL of the water sample. The accuracy of the method was confirmed by analysis of certified reference materials of waters (“Trace Metals in Drinking Water” and SRM 1643e “Trace Elements in Water”) with satisfactory results. The method developed was successfully applied to the pre-concentration and determination of trace quantities of beryllium and chromium(VI) in different natural waters.
PERFORMANCE OF THE JOUYBAN-ACREE MODEL FOR CORRELATING THE SOLUBILITY OF INDOMETHACIN AND ETHYLHEXYL TRIAZONE IN ETHYL ACETATE + ETHANOL MIXTURES

En este trabajo se evalua la validez del modelo de Jouyban-Acree (J – A) para la correlacion de la solubilidad de estos dos agentes de uso farmaceutico en mezclas acetato de etilo + etanol, en funcion de la composicion solvente y de la temperatura, en el intervalo entre 293,15 y 313,15 K. El modelo J – A requiere unicamente de los valores experimentales de solubilidad de los farmacos en los solventes puros en funcion de la temperatura. Se encuentra que los valores obtenidos con los dos compuestos presentan desviaciones cercanas al 30% respecto a los valores experimentales de solubilidad.
Numerical Investigation on the Flow and Heat Transfer Characteristics of the Superheated Steam in the Wedge Duct With Pin-Fins

By using the CFX software, the three-dimensional flow and heat transfer characteristics in the cooling duct with pin-fin in the blade trailing edge were numerically simulated. The effects of pin-fin arrangements, Reynolds number, steam superheat degrees, streamwise pin density and convergence angle of the wedge duct on the flow and heat transfer characteristics were analysed. The results show that the Nusselt number on the endwall and pin-fin surfaces as well as the pin-fin row averaged Nusselt number increase with the increasing of Reynolds number, while it decreased with the with the increasing of X/D. The pressure drop increases with the increasing of Reynolds number while decreases with the increasing of X/D in the wedge duct. The degree of superheat has little effect on the pressure loss in the wedge duct. A comprehensive analysis and comparison show that the highest thermal performance is reached in the wedge duct when the value of X/D is 1.5. Copyright © 2013 by ASME
Inkjet Printing Patterned Photonic Crystal Domes for Wide Viewing‐Angle Displays by Controlling the Sliding Three Phase Contact Line

Photonic crystals (PCs), by virtue of their light manipulation capacity, have shown promising applications in integrated optical devices, [ 1,2 ] full-color displays, [ 3,4 ] biological sensors and other fi elds. [ 5 ] In practical applications, the intrinsic angle-dependence property of PCs restrains their performances in wide viewing-angle display devices. [ 6 ] Various novel materials and assembly structures have been developed to realize angle-independent structure colors. [ 7,8 ] For example, quasiamorphous assembly or multilayered redge structures are employed to realize overall colors. [ 7 ] Although the structure with a shortrange order exhibits coherent scattering, the disorder state enhances incoherent scattering. Thus the amorphous assembly displays whitish structural color. To improve the saturation of the structural color from the amorphous assembly, Takeoka et al. and Foster et al. introduced black materials into the assembly and successfully obtained angle-independent structural colors. [ 7d,f ] Spherical PCs have advantages of achieving bright isotropic structural colors. [ 8 ] Gu and Yang et al. prepared colloidal crystal beads with angle-independent refl ection colors from microfl uidic colloidal droplet templates. [ 8a–d ]