Miracle-dz/UniFAR-FTUs huggingface dataset:
Synthesis and Characterization of Phenoxy Modified Epoxy Blends

The blends of Tetraglycidyl-4,4'-Diaminodiphenyl Methane (TGDDM) and Diglycidyl Ether of Bisphenol-A (DGEBA) type of epoxy resin synthesized by using different amount of engineering thermoplastic phenoxy resin (20 and 30 phr.). These blends were cured with aromatic amine type curing agent i.e. 4,4'-Diaminodiphenyl Methane (DDM) and 4,4'-Diaminodiphenyl Sulphone (DDS). The resulting cured blend was characterized by Scanning Electron Microscopy (SEM) and Fourier Transform Infra Red Spectroscopy (FTIR). The activation energy (Ea) for thermal degradation, thermal stability, Limiting Oxygen Index (LOI) values and degradation kinetics of the blends were studied by Thermo gravimetric analysis (TGA) using Coats and Red-fern method. The experimental results showed that the glass transition temperature (Tg) and activation energy (Ea) of different DGEBA/phenoxy cured blends increased when the phenoxy content was increased from 20 and 30 parts per hundred resin (phr.). DSC and SEM analysis of different blends showed that phase separation occurred in all TGDDM/phenoxy cured blends; as two glass transition temperatures were observed in these blends.
Raman Spectroscopy as a Tool to Address Individual Graphene Layers in Few-Layer Graphene

We developed a new general approach to address individual graphene sheets in few-layer graphene by Raman spectroscopy. Our method is based on isotope labeling of individual layers during their synthesis and subsequent transfer to form multilayered graphene. The power of the procedure is demonstrated in the analysis of the interactions of individual layers with the substrate and with the environment. In addition, we measured Raman spectra of individual graphene layers in 3-LG during electrochemical doping. We show that they do not exhibit the same level of doping as one another and the doping level is dependent on layer position with respect to the substrate.
Production, separation and speciation of no-carrier-added Hg radionuclides using greener methodologies

Abstract Species dependent studies of no-carrier-added (nca) mercury were carried out using radioanalytical technique coupled with two greener analytical methodologies. The adsorption of nca 195m,gHg and 197mHg radionuclides on chitosan biopolymer and cloud point extraction (CPE) was studied to develop environmentally sustainable speciation methodologies at ultra trace level. Species information was obtained by comparing the adsorption profile of nca radiomercury on chitosan biopolymer with the software code CHEAQS PRO. Results obtained from the adsorption study were validated by CPE technique using non ionic surfactant and mixed micelle. Both the experiments established that nca Hg existed as Hg(II). The experimental results support the presence of HgCl2 species over the pH range 2–4, whereas Hg(OH)2 is the main species over the pH range 6–8. Chitosan biopolymer and mixed micelle [Triton-X-114 and cetyltrimethylammonium bromide (CTAB)] constitute an efficient reagent for the preconcentration of ultra trace level mercury.
Proton N.M.R. studies of chemical and diffusive exchange in carbohydrate systems

A computer-simulated stochastic model is developed capable of predicting the combined effects of chemical and diffusive exchange on the transverse relaxation of spin-1/2 nuclei in a heterogeneous system. Comparison is first made with previous analytical theories for the special case of two site chemical exchange in a homogeneous system and the experimental data on several homogeneous aqueous carbohydrate systems are analysed. Results show that transverse water proton relaxation in these systems is dominated by proton exchange between water and carbohydrate hydroxyl groups. Analysis of model heterogeneous carbohydrate systems shows that in addition to chemical exchange, diffusion coefficients, particle morphology and local magnetic field gradients all have a role to play in determining the proton relaxation behaviour.
Flow injection determination of copper and iron in seafoods by a continuous ultrasound-assisted extraction system coupled to FAAS

Copper and iron were extracted on-line from solid seafood samples by a robust, fast and simple continuous ultrasound-assisted extraction system (CUES). CUES is connected to a flow-injection manifold, which allows on-line flame atomic absorption spectrometric determination of copper and iron. Experimental designs were used to optimize the continuous leaching procedures. These methods allowed a total sampling frequency of 46 and 18 samples per hour, with relative standard deviations of 1.6% and 0.3%, for copper and iron, respectively (for a sample containing 13.6 µg/g of copper and 217.3 µg/g of iron (dry mass)). The limits of detection for 30 mg of sample were 0.3 µg/g for copper and 0.6 µg/g for iron (dry mass). Analytical procedures were verified by the analysis of a standard reference material (lobster hepatopancreas marine, TORT-1) and were applied to several real seafood samples from the estuaries of Galicia (Spain) with satisfactory results.
One-pot preparation of thin nanoporous copper foils with enhanced light absorption and SERS properties

A facile hydrothermal method has been presented to prepare free-standing nanoporous Cu foils (NPCFs) having a thickness of ~1.4 μm and an area of up to ~10 cm2, which were grown on the inwall of a Teflon-lined autoclave by assembling and reducing CuxO nanoparticle intermediates and then peeling themselves off in the cooling period of the reaction. The pore sizes of NPCFs can be adjusted by varying the reaction time. It is observed that the NPCFs with water absorbed inside their nanopores show excellent flexibility while dried ones exhibit a highly hydrophobic nature. Compared with commercially available Cu foils, the as-synthesized NPCFs show enhanced ability to absorb light over a wide range of wavelengths from 200 to 1000 nm because of their nanoporosity. The highest absorbance and the biggest enhancement can reach 86% at 300 nm and 43% at 575 nm, respectively. The smooth side of NPCFs with a hemisphere-like surface demonstrates outstanding surface-enhanced Raman scattering performance by employing Rhodamine 6G as the probe molecule, which agrees well with the results of finite-difference time-domain simulation.
Modelling of Chlorophenol Treatment in Aqueous Solutions. 1. Ozonation and Ozonation Combined with UV Radiation under Acidic Conditions

Abstract Treatment of 2-chlorophenol (2-CP), 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP) in aqueous solutions with direct photolysis (254 nm), ozonation and ozonation with photolysis was studied. A model was developed to simulate chlorophenol treatment in a semibatch column using these processes under acidic conditions in which the chemical reactions are slow. Satisfactory results were obtained in simulating the chlorophenol and ozone concentrations, and the concentrations of an aromatic quinone, hydrogen peroxide and chloride ions formed in the course of the processes. Chlorophenol oxidation systems, however, appeared to be very complex and the formation of intermediate and final products were dependent on the reaction conditions. The degradation rate of chlorophenols was not enhanced by the combination of ozone with UV radiation compared with ozonation alone. Oxidation at low pH in both processes proceeded mainly through reactions with molecular ozone.
Organotypic functional cultures of human liver cells for long-term maintenance and assessment of drug-induced metabolome effects

The goals of this thesis were (i) to establish and improve organotypic liver cell culture techniques for long-term pharmacological studies and (ii) to develop and apply a metabolomics based approach for the assessment of drug-induced effects. As first model, a 3D bioreactor system was characterized in terms of cell physiology and functionality. Primary human hepatocytes could be kept viable and functional for more than 2 weeks in this system. Optimization of the system allowed determination of oxygen uptake rates and viability. As second 3D system, a hanging drop method was successfully applied for the generation of organotypic cultures as high-throughput in vitro model for toxicity studies. For the investigation of drug-induced metabolic effects, a metabolomics approach based on GCTOF-MS combined with multivariate statistics was developed. In 2D cultures of primary human hepatocytes, both short-term (up to 4 days) and long-term (3 weeks) drug-induced effects were detected at clinically relevant concentrations, showing the sensitivity of the established method. Both 3D cultivation methods used in this thesis represent a step forward to organotypic cultures as in vitro alternatives to animals and are particularly suitable for the investigation of chronic toxicity. The established metabolomics approach is a sensitive tool to assess drug-induced changes even at subtoxic concentrations and can be applied to other cell types and cultivation systems in the future. Die Ziele dieser Arbeit waren (i) die Etablierung und Verbesserung von organotypischen Leberzellkulturtechniken fur pharmakologische Studien und (ii) die Entwicklung und Anwendung einer Metabolomics-Methode zur Detektion von Wirkstoff-induzierten Effekten. Als erstes Modell wurde ein 3D Bioreaktor in Hinblick auf Zellphysiologie und -funktionalitat untersucht. Primare Hepatozyten konnten uber mehr als 2 Wochen vital und funktionell in diesem System kultiviert werden. Eine Systemoptimierung erlaubte die Bestimmung von Sauerstoffaufnahmeraten und Viabilitat. Als zweites 3D System wurde die Methode des hangenden Tropfens erfolgreich zur Herstellung von organotypischen Kulturen fur Toxizitatsstudien eingesetzt. Zur Untersuchung von Wirkstoff-induzierten metabolischen Effekten wurde in dieser Arbeit eine Metabolomics-Methode entwickelt, basierend auf einer Kombination von GCTOF-MS und multivariater Statistik. In 2D Kulturen von primaren Hepatozyten wurden sowohl Kurzzeit- (bis zu 4 Tagen) als auch Langzeit- (3 Wochen) Effekte bei klinisch relevanten Konzentrationen nachgewiesen, was die Sensitivitat der Methode zeigt. Beide 3D Systeme, die in dieser Arbeit eingesetzt wurden, sind als organotypische in vitro Alternativen zu Tierversuchen zur Untersuchung von chronischer Toxizitat geeignet. Die etablierte Metabolomics-Methode ist eine sensitive Technik um Wirkstoff-induzierte, subtoxische Effekte zu detektieren und kann in Zukunft auf andere Zelltypen und -systeme angewendet werden.
Graphene Nano-“patches” on a Carbon Nanotube Network for Highly Transparent/Conductive Thin Film Applications

Freestanding carbon-based composite thin films, consisting of a carbon nanotube network patched with graphene sheets, were assembled by a solid-phase layer-stacking approach with ethanol wetting. The composite films are highly flexible, transparent, and conductive, showing a sheet resistance of 735 Ω/sq at 90% transmittance (at 550 nm). Under AM1.5 illumination, heterojunction solar cells made from the composite films and n-type silicon show a power conversion efficiency of up to 5.2%.
Chain extension in electrospun polystyrene fibres: a SANS study

Small angle neutron scattering techniques were used to quantify the size and shape of the chain conformation in electrospun fibres of atactic polystyrene prepared from solutions in methyl ethyl ketone. Aligned arrays of fibres were collected onto a rotating collector with tangential velocity varying between 0 ms−1 and ∼15 ms−1. The measured radii of gyration of the polystyrene chains were found to be slightly higher than that expected for samples prepared from solutions in the concentrated regime. The ratio of the radius of gyration parallel and perpendicular to the chain axis was found to be ∼1.05 in contrast to the substantial macroscopic shape transformation intrinsic to electrospinning. When the tangential velocity of the rotating collector was greater than the flight velocity of the fibres (ca. 4 ms−1), a further extension of the polymer chains was observed with a ratio of the radii of gyration increasing to 1.20 at the highest collector speeds. It is proposed that the heterogeneous processes involved, particularly solvent evaporation and the formation of a polymer skin during electrospinning play a significant role in determining the level of molecular anisotropy in the fibres.
Growth Response of Cucumber to Hydrophilic Polymer Application Under Different Soil Moisture Levels

ABSTRACT The effect of hydrophilic polymer addition on the growth of cucumber (Cucumis sativus L., cv. Dina) was investigated under different levels of soil moisture. The plants were grown in pots filled with 7 kg of moderately calcareous loam soil. The soil was mixed with five concentrations of hydrophilic polymer Broad Leaf (P-4). These concentrations were 0.0% (control), 0.1, 0.2, 0.3, and 0.4% on a dry-weight basis. Three levels of soil moisture, namely, 25, 50, and 75% of field capacity of untreated soil (control), were used in this study. The results showed a significant increase in the vegetative growth with increasing polymer concentration up to 0.3%. Further increase to 0.4% of P-4 had no significant effect on plant growth. A significant interaction was observed between polymer concentration and soil moisture level. Growing plants under 50% of field capacity with 0.2% polymer concentration resulted in more vegetative growth than did other treatments. Addition of hydrophilic polymers was most effe.
A STUDY OF 2H- AND 2D-BENZOTRIAZOLE IN THEIR LOWEST ELECTRONIC STATES BY UV-LASER DOUBLE RESONANCE SPECTROSCOPY

$^{a}$ W. Roth, Ch. Jacoby, A. Westphal and M. Schmitt accepted for publication in J. Phys. Chem. (1989) $^{b}$ G. Berden, E. Jalviste and W.L. Meerts Chem. Phys. Lett. 226 (1994) 305-309
First Synthesis of Mosquito Larvicidal Butenolides I and II

Utilizing aldol condensation and β-elimination as the key steps, butenolides I and II in excellent enantiomeric purity have been concisely synthesized for the first time. According to the rotation difference between synthetic samples and natural products, the rotations were corrected by the calculation upon HPLC measurements. In addition, an efficient way to synthesize methyl pentadec-14-enoate was developed.
Repeat Injection Studies of Technetium-99M-Labeled Peg-Liposomes in the Same Animal

AbstractThis study was designed to determine if repeat injections of polyethylene glycol (PEG) coated liposomes in the same animal lead to a change in biodistribution due to a biological response. To evaluate the long-term storage of PEG-liposomes for imaging applications and to remove any concerns of batch variability, one large batch of PEG-liposomes containing glutathione and sucrose was prepared and used for the entire study. On each day that an imaging study was performed, an aliquot of PEG-liposomes were labeled with techne-tium-99m (99mTc) using hexamethylpropyleneamine oxime. Rabbits (n = 4) were injected with 99mTc-PEG-liposomes (2 ml; 13 mg phospholipid/kg body wt; 2 mCi 99mTc-activity) at 8 days after manufacture and imaged under a gamma camera. Heart-to-lung ratios, heart-to-liver ratios and organ activities were determined by region of interest analysis. Blood samples were collected to generate blood clearance curves. Six weeks later the same rabbits were given a second dose of 99mTc-PEG-lipo.
High thermoelectric figure-of-merit in p-type nanostructured (Bi,Sb)2Te3 fabricated viahydrothermal synthesis and evacuated-and-encapsulated sintering

High ZT values of nanostructured Bi2−xSbxTe3 for energy conversion are fabricated by hydrothermal methods followed by cold-pressing and sintering in an evacuated and encapsulated ampoule. We show that the sample with a nominal composition of x = 1.55 exhibits a dimensionless figure of merit ZT = 1.65 at 290 K and 1.75 at 270 K with significant 60–70% improvement of that of the commercial state-of-the-art Bi2Te3 materials around room temperature. The significant ZT improvement arises from the much-reduced thermal conductivity. The low thermal conductivity is mainly due to the increased phonon scattering in the nanostructured materials.
PREDICTING TECHNOLOGY SUCCESS BASED ON PATENT DATA, USING A WIDE AND DEEP NEURAL NETWORK AND A RECURRENT NEURAL NETWORK

The temporal dynamic growth of technology patents for a time sequence is a major indicator to measure the technology power and relevance in innovative technology-based product/service development. A new method for predicting success of innovative technology is proposed based on patent data and using Neural Networks models. Technology patents data are extracted from the United States Patent and Trademark Office (USPTO) and used to predict the future patent growth of two candidate technologies: "Cloud/Client computing" and "Autonomous Vehicles". This approach is implemented using two Neural Networks models for accuracy comparison: a Wide and Deep Neural Network (WDNN) and a Recurrent Neural Network (RNN). As a result, RNN achieves a better performance and accuracy and outperforms the WDNN in the context of small datasets.
Catalytic Nazarov Cyclization: The State of the Art

This transformation has received tremendous attention in the field of organic synthesis due to its ability to form synthetically versatile cyclopentenones. With appropriately substituted dienones, the orbital reorganization implants new stereocenters in the oxyallyl cation (3), which are retained in the pentacyclic product (5). In terms of the reaction mechanism (Scheme 1), the coordination of either a Brønsted or a Lewis acid (LA) promoter to the dienone (1) induces the electrocyclization of the pentadienyl cation (2). Consistent with the principle of conservation of orbital symmetry, a conrotatory closure proceeds to form an oxyallyl cation (3), having an anti relationship between R and R. This intermediate has the potential to go through diverse reaction pathways such as carbocationic rearrangements or interception from 3 with external nucleophiles. Traditionally, elimination of a proton generates a promoter bound enolate (4) that furnishes a cyclopentenone (5) upon reprotonation. Since the 2005 reviews of the Nazarov reaction by Frontier and Collison, Tius, and Pellissier, a number of new catalytic and stoichiometric reactions 15, 19–60] have been reported that address synthetic problems associated with this transformation. This review will discuss the catalytic advances in the Nazarov cyclization since 2005, including the design of new catalysts, formulation of new conditions, variations of the electrocyclization, tandem processes, strategies that result in enantioinduction, and application to natural product synthesis. The catalysts have been categorized into the following subclasses: Brønsted acids, organocatalysts, heterogeneous catalysts, Lewis acids including transition-metal catalysts, and a supramolecular host.
The nature of an iron oxide—organic iron association in a peaty environment

Abstract Fe oxides deposited in ditches draining a bog in the Harz Mountains, Northern Germany, consist essentially of a two-XRD line ferrihydrite that has a magnetic hyperfine field of only 46·5 T at 4·2 K. Pyrophosphate extraction led to an incomplete separation of this from organically-bound Fe, which was depleted in the residue and particularly enriched in the dialysate of the extract. Decomposition of humics with H2O2 led to a further depletion of organic Fe, but also increased the number of XRD lines of the ferrihydrite to six, and raised the hyperfine field by ∼1 T. These modifications are probably the result of an improved interparticle coherence.
Effect of Cooling Rate on Pore Distribution in Quenched Sodium Borosilicate Glasses

The distribution of pores, based on spinodal phase separation in sodium borosilicate glasses that were rapidly quenched at different cooling rates, was investigated. The N2 adsorption−desorption behavior of samples shows that the pore is of the micropore type with pore size <1 nm. The air-quenched samples (quenched at 10 K/s) have larger pore volume and surface area than roller-quenched samples (quenched at 106 K/s). This effect is explained by the amplitudes of a series of the spinodal decomposition waves that are formed under cooling and increase in the air-quenched samples. Therefore, the pore volume and surface area increase with decreasing cooling rate according to an acid-leaching model that is proposed in the present investigation.
GaN MSM Ultraviolet Photodetectors with Transparent and Thermally Stable RuO2 and IrO2 Schottky Contacts

Ruthenium oxide and iridium oxide were used as the Schottky barrier materials of GaN metal-semiconductor-metal (MSM) ultraviolet photodetector. After annealing Ru and Ir contacts at 500°C under O 2 ambient, the reverse leakage current density at -5 V drastically decreased by four orders of magnitude. Furthermore, the Schottky barrier height and optical transmittance at 360 nm simultaneously increased to 1.43 eV and 71.5% for the Ru, and to 1.48 eV and 74.8% for the Ir contact. The dramatic improvements originated from the formation of thermally stable oxide phases, RuO 2 and IrO 2 , by the annealing, resulting in the increase in the responsivity of the GaN MSM photodetector by one order of magnitude in comparison with the photodetector with Pt Schottky contact.
Field Emission from a Composite of Graphene Sheets and ZnO Nanowires

There is a problem with field emission from graphene sheets (GSs) because existing deposition methods lead to sheets that have planar morphological features along entire substrates, which limits field enhancement. To overcome this problem, here we grow pyramid-like GSs on Ni-coated ZnO nanowires via a “base growth” mechanism using plasma-enhanced chemical vapor deposition. The surface morphologies of ZnO−GSs can be controlled by the density of the Ni nanoparticles and deposition time. The ZnO−GSs has a lower turn-on field, 1.3 V/μm, compared to that, 2.5 V/μm, of pure ZnO at a current density of 1 μA/cm2, implying avenues for potential applications of graphene and ZnO.
An optimized harmonic reference system for the evaluation of discretized path integrals

A harmonic reference system for Monte Carlo evaluation of discretized path integrals is developed. Various equilibrium averages are calculated for a one‐dimensional quartic oscillator, and compared to converged basis set results; it is shown that use of the reference system substantially decreases the number of discretized points (relative to the free particle reference system) necessary to compute accurate quantum mechanical expectation values.
Interaction of side-chains in poly(3-alkylthiophene) lattices

Atomistic simulation investigations of poly(3-alkylthiophene) lattices lead to fully relaxed structures that are consistent with the overall results derived from diffraction studies. The compressibilities of the lattices are calculated to be highly anisotropic, and the interdigitation of the alkyl chains on adjacent polymer chains are predicted to give rise to well defined polymorphs separated by high-energy barriers. The result is consistent with the lubricative effect of alkyl chain bilayers. The pressures calculated to be required to induce the occurrence of the appropriate phase changes (1–10 kbar) are close to those used in experimental investigations of pressure-induced changes in these polymer systems. Current theories of thermochromicity are tested by investigating the redistribution of excess conformational steric energy in the alkyl side-chains to the polymer backbone. Results indicate that the thiophene rings fold rather than twist around the polymer axis.