Miracle-dz/UniFAR-FTUs huggingface dataset:
A simple and eco-sustainable method for the O-Boc protection/deprotection of various phenolic structures under water-mediated/catalyst-free conditions

A greener, efficient, and chemoselective protocol for O-Boc protection/deprotection of a wide range of phenol derivatives is reported under catalyst-free conditions in water-related systems. Unlike previous reports, no additional reagents or catalysts were used, and workup fulfils green chemistry requirements, making the present method even more interesting.
Shear-induced crystallization of poly(ε-caprolactone). 2. Evolution of birefringence and dichroism

We have studied the crystallization of poly(e-caprolactone) (PCL) with in situ optical rheometry and ex situ optical microscopy as a function of applied stress. The evolution of the birefringence and dichroism was monitored in parallel with the viscosity following a temperature jump from the melt to a final crystallization temperature for different values of stress. In optical microscopy we found an increased nucleation density which resulted in the speed-up of the crystallization process in the strained samples as detected by optical rheometry. Changes in the crystal structure observed in optical microscopy were found to correlate well with the evolution of birefringence and dichroism. An increasing volume fraction of axialites at early times and crystal branching and randomization in orientation at later times were found to control the signal from optical rheometry. A decoupling of the evolution of shear viscosity from the optical rheometry signals has been observed at high shear stress attributed to pa.
Intraband absorption for InAs/GaAs quantum dot infrared photodetectors

Using the envelope function theory, intraband absorption is calculated for InAs/GaAs pyramidal quantum dots. The effects of the quantum dot geometry, such as the dot shape and the wetting layer (WL) thickness, and the coupling between the WL and bound states on the intraband transitions are systematically studied. Strong in-plane polarized absorption from the first excited state occurs in the low mid-infrared region, while stronger broadband z-polarized absorption features are located at higher frequencies. This polarization dependence is in agreement with the experiment [Appl. Phys. Lett. 82, 630 (2003)] and is due to the dot geometry. The WL can induce both in-plane and z-polarized absorption. Absorption of in-plane polarized light from the ground state to the WL and continuum states is found to be negligible. Thus, for strong normal-incidence photodetection, absorption from the first excited state should be exploited.
Novel drug delivery system for captopril

AbstractIt is known that drug substances showing no difference in absorbance along the whole gastro-intestinal (GI) tract are suitable for SR-formulations with an extended release characteristic. However, a decrease in bioavailability from proximal to distal parts of the gut may be suited for a limited retard effect. In this investigation, attempts have been made to design a suitable delivery system for captopril which is poorly bio-available from the alkaline regions of the GI-tract. The principles of ‘Bioadhesion’ as well as ‘Gastric Floating Systems’ are utilized in this study.
Integrating Guided Inquiry into a Traditional Chemistry Curricular Framework

The case study presented in this paper examines the work of one high school chemistry teacher who has integrated guided inquiry into a yearlong, traditional curricular framework in ways that take into account the constraints and realities of her classroom. The study’s findings suggest (1) the extent and frequency to which teachers can realistically integrate guided inquiry into existing science curricula, (2) the manner in which teachers can make effective transitions into and out of a guided inquiry, and (3) the way in which teachers can set an overarching goal to bring a driving purpose to all of the guided inquiries that the students experience. Based on the insights gained from the current case study, an argument is made that researchers should examine the practice of other teachers (especially in the common subjects of biology, chemistry, and physics) who have integrated guided inquiry into the fabric of their curricula. By doing so, a library of case studies can be built that will provide science teachers with new ideas on how inquiry can be holistically and productively integrated into yearlong traditional curricular frameworks.
Enhanced Piezoelectric Properties of Electrospun Poly(vinylidene fluoride)/Multiwalled Carbon Nanotube Composites Due to High β-Phase Formation in Poly(vinylidene fluoride)

We prepared poly(vinylidene fluoride) (PVDF)/multiwalled carbon nanotube (MWCNT) nanocomposites using the electrospinning process and investigated the effects of varying the MWCNT content, as well as the additional use of drawing and poling on the polymorphic behavior and electroactive (piezoelectric) properties of the membranes obtained. Fourier transform infrared spectroscopy and wide-angle X-ray diffraction revealed that dramatic changes occurred in the β-phase crystal formation with the MWCNT loading. This was attributed to the nucleation effects of the MWCNTs as well as the intense stretching of the PVDF jets in the electrospinning process. The remanent polarization and piezoelectric response increased with the amount of MWCNTs and piezoelectric β-phase crystals. A further mechanical stretching and electric poling process induced not only highly oriented β-phase crystallites, but also very good ferroelectric and piezoelectric performances. In the drawn samples, the interfacial interaction between the.
Vermicompost and Fertilizer Application: Effect on Productivity and Profitability of Baby Corn (Zea Mays L.) and Soil Health

ABSTRACT Earthworm digested wastes (vermicompost) are being produced in increasing quantities to make farming sustainable. A study was carried out for two consecutive years (2007–09) at the Agricultural Experimental Farm of Indian Statistical Institute, Giridih, India on sandy loam soil in factorial randomized block design with three replications. Baby corn (cv. Early Composite) was grown without vermicompost (V0) or with vermicompost (V1: @ 10 Mg ha−1) in combination with three recommended doses of fertilizers [F1: 50%, F2: 100% (N:P2O5:K2O = 150:60:60 kg ha−1) and F3: 150% RDF] besides an absolute control (F0: no-NPK) to assess their effect on baby corn productivity and soil health. Vermicompost applied plots recorded considerably higher cob (0.717 Mg ha−1) and green fodder (17.58 Mg ha−1) yield. Among the fertilizers, baby corn grown with F3 yielded maximum cob (0.759 Mg ha−1) and green fodder (18.46 Mg ha−1). Vermicompost application built-up soil nutrient like nitrogen (145 kg ha−1), phosphorus (16 kg ha−1), potassium (190 kg ha−1), organic carbon (0.78%), and enhanced cation exchange capacity (12.19 Cmol+ kg−1), microbial [basal soil respiration, microbial biomass carbon, microbial quotient, and metabolic quotient] and enzyme activities (urease and acid phosphatase). However, microbial and enzyme activities were minimum with F3. Vermicompost and F2 treatments were most remunerative. Use of vermicompost not only reduces the requirement of chemical fertilizers but also supplements important all essential nutrients to increase crop yield besides improving the soil properties and processes.
Heat Capacities of Tetracene and Pentacene

New solid state heat capacity data for tetracene and pentacene are reported in the temperature range (258 to 600) K. The heat capacity measurements were performed using the step method with a Setaram Micro DSC III calorimeter (Institute of Chemical Technology, Prague) and a Setaram TG-DSC 111 (University of Alberta) calorimeter. These new heat capacity data are shown to be in good agreement with one another and with several solid state constant-pressure heat capacity estimation methods and quantum mechanical calculations. The new results highlight errors in the solid state heat capacity and melting point databases for polynuclear aromatic hydrocarbons.
SANS Polarization Analysis with Nuclear-Spin-Polarized 3He

A neutron spin filter based on transmission through nuclear-spin-polarized 3He gas has been applied to polarization analysis of small angle neutron scattering (SANS). Such spin filters, which are based on the large spin dependence of the absorption of neutrons by 3He, make SANS polarization analysis possible because of their large angular acceptance. In the present experiment, a 3He-based analyzer was employed to separate nuclear scattering into its coherent and spin-incoherent components. Polarized 3He analyzers were prepared by two different optical pumping methods and installed on the NG3 SANS instrument at the NIST Center for Neutron Research (NCNR). Measurements were taken on cellophane tape and silica gel, for which the scattering is almost completely incoherent and coherent, respectively, and on a combined sample. For the combined sample, separation of the coherent part from the incoherent part was successfully demonstrated using polarization analysis.
Reactivity of Peroxynitrite with Melatonin as a Function of pH and CO2 Content

Peroxynitrite is known to be a strong oxidant and a nitrating agent of aromatic phenolic or heterocyclic rings, depending on its form in aqueous solutions: the anion ONOO−, its conjugate acid ONOOH, or its CO2 adduct ONOOCO2−. Various reactions have been observed with melatonin (1), a tryptophan derivative, in phosphate-buffered solutions. Melatonin (1) is recognized as a scavenger of several strong oxidants (HO·, H2O2, .) accounting for its biological and pharmacological effects. Here we describe two oxidation routes that give rise to indol-2-ones 2 (probably via a 2,3-epoxyindole) and kynuramines 6 (by cleavage of the pyrrole ring), attributable to reactions of ONOOH and ONOO−, respectively, according to the effects of pH and CO2 content. At pH = 7.6 and in the presence of CO2, an important conversion is the cyclization of the lateral amide function, giving 3-substituted pyrroloindoles 4. At neutral pH, therefore, all routes coexist, with a balance between indol-2-ones 2 and pyrroloindoles 4 on the one side and kynuramines 6 on the other, depending on the CO2 content. Furthermore, under specific conditions substitutions of the hydrogen atom on the pyrrole nitrogen atom, affording the 1-nitro- (5) and the unstable 1-nitrosomelatonin (7), are among the major transformations: formation of the nitrosation product, together with that of kynuramines 6, rises sharply when the pH of the medium increases, confirming the implication of ONOO− in their synthesis; conversely, both reaction yields decrease with increasing CO2 content, to favor 1-nitromelatonin (5). Finally, nitration by aromatic substitution occurring essentially on C-4 becomes important at acidic pH, and also at pH = 7.6 over a narrow range of CO2 concentrations. Most of the reactions are typical of the indole moiety, suggesting that melatonin (1) is a model of potential use for investigation of tryptophan chemistry with peroxynitrite. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Accurate structures and binding energies for small water clusters: The water trimer

The global minimum on the water trimer potential energy surface has been investigated by means of second-order Mo/ller-Plesset (MP2) perturbation theory employing the series of correlation-consistent basis sets aug-cc-pVXZ (X = D, T, Q, 5, 6), the largest of which contains 1329 basis functions. Definitive predictions are made for the binding energy and equilibrium structure, and improved values are presented for the harmonic vibrational frequencies. A value of 15.82±0.05 kcal mol−1 is advanced for the infinite basis set frozen core MP2 binding energy, obtained by extrapolation of MP2 correlation energies computed at the aug-cc-pVQZ MP2 geometry. Inclusion of core correlation, using the aug-cc-pCV5Z basis set, has been found to increase the binding energy by 0.08 kcal mol−1, and after consideration of core correlation and higher-order correlation effects, the classical binding energy for the water trimer is estimated to be 15.9±0.2 kcal mol−1. A zero-point vibrational correction of −5.43 kcal mol−1 has bee.
Degradation of Trichloroethylene and Tetrachloroethylene in Simulated Groundwater in a Flow-Through Photosono Reactor

AbstractSimulated groundwater solutions contaminated with trichloroethylene (TCE) and tetrachloroethylene (PCE) were treated in a flow-through reactor equipped with ultrasound (US) and ultraviolet light (UV) sources. The treatment process was operated using UV or US individually, and UV and US concurrently (UVUS). The solutions contaminated with TCE or PCE were exposed to UV light emitted from Hg-arc lamps surrounding the quartz reactor vessel, and to acoustic waves from a US horn located at the bottom of the reactor vessel. The rate constants (k) of photolysis by UV, sonolysis by US, and photosonolysis by UVUS were evaluated using a mathematical model in conjunction with a nonlinear regression analysis. The removal efficiencies (E) for the UV, US, and UVUS treatments were also determined. For TCE, the US rate constant (kus=0.016±0.010 min−1) and the UV rate constant (kuv=0.076±0.004 min−1) yield the theoretical additive rate constant (kad) of 0.092 min−1, whereas the observed UVUS rate constant (kuvus.
Effects of Threading Dislocation Density on the Gate Leakage of AlGaN/GaN Heterostructures for High Electron Mobility Transistors

AlGaN/GaN heterostructures were regrown on three semi-insulating GaN templates with threading dislocation densities of ∼2×1010, ∼5×108, and ∼5×107 cm-2. Regrowths were carried out under Ga-rich conditions by plasma-assisted molecular beam epitaxy to determine the effects of threading dislocation density on leakage through Schottky contacts on the AlGaN/GaN heterostructures. A similar AlGaN/GaN heterostructure was directly grown on 4H-SiC under Ga-rich conditions for comparison with the regrown heterostructures. High electron mobility transistors were fabricated. Decreasing the threading dislocation density from ∼2×1010 to ∼5×107 cm-2 yielded up to a 45-fold decrease in the average reverse Schottky diode current at -10 V bias.
Response Surface Methodology to Supercritical Carbon Dioxide Extraction of Essential Oil from Amormum krevanh Pierre

Abstract Response surface methodology was employed to investigate the effects of operating conditions and predict the optimal conditions for supercritical carbon dioxide extraction of essential oil from Amomum krevanh Pierre. The factors investigated were operating temperature (33–67°C), the operating pressure (91–259 bar), and the extraction time (20–70 min). The main effect of the operating pressure and the interaction effect between the operating temperature and the extraction time were found to be significant factors. From the response surface model, an optimal condition for essential oil content within the range of experimental study was found to be at 33°C, 175 bar, and 70 min, which gave the oil yield of 17.3 mg/g dry wt. The essential oil yield obtained at all conditions were higher than that obtained by organic solvent extraction (9.74 mg/g dry wt.) while the composition of the extract was similar, which were 1,8-cineole (70.87%), β-pinene (8.89%), and limonene (4.81%).
Effect of aluminium on cow pea (Vigna sinensis L. CV. Kanakamony)

Studies were conducted to assess effects of aluminium on cow pea (Vigna sinensis L. CV. Kanakamony) through germination, hydroponic and pot culture techniques. Germination studies showed that aluminium does not inhibit germination up to a concentration of 300 ppm, while hydroponic and pot culture studies indicated that the metal at concentrations greater than 3 ppm has effect on the growth of plants. This is demonstrated by retardation in growth and suppression in chlorophyll biosynthesis. Morphological stress was also noticed on depression in root and shoot systems, chlorosis of leaves etc. Stunted growth and reduced yield were other symptoms. Growth coefficient studies (λS) showed that better growth was found in plants grown in ppm concentrations of less than 2 ppm Aluminium. As growth advanced, marked variation in the morphological characteristics such as nodule formation, height and branching of stem, flower development, etc. were observed. Delay in flower development was observed in plants grown in metal treated soil from 3 ppm to 15 ppm. In 20 ppm concentrations flower buds were seen to be aborted. The present study focuses on an integrated assessment of aluminium toxicity on the morphological and physiological changes in cow pea (Vigna sinensis L. CV. Kanakamony).
Syntheses and crystal structures of triorganotin(IV) complexes of schiff base derived from 4‐amino‐5‐phenyl‐4H‐1,2,4‐trizole‐3‐thiol

Four triorganotin complexes of the types [(Ph3Sn)(C15H10FN4S)] (3), [(CH3)3Sn(C15H10FN4S)]n (4), [(Ph3Sn)(C13H9FN4S2)] (5), and [(CH3)3Sn(C13H9FN4S2)]n (6) have been obtained by Schiff base compound 1 (derived from 4-fluorobenzaldehyde) and compound 2 (derived from thiophene-2-carboxadehyde) with triorganotin chloride in the presence of sodium ethoxide. All the complexes were characterized by elemental analysis, IR, and NMR spectroscopies, and X-ray diffraction analyses, which revealed that complexes 3 and 5 are mononuclear structures, complex 4 and 6 are one-dimensional zigzag infinite chains via N Sn and S Sn bonding interactions. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:583–591, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20481
A New 3D Metal-Organic Framework Based on a Flexible and Rigid Co-Ligand: Synthesis, Structure, and Magnetic Properties

A new metal-organic framework, {[Co1.5(μ2-OH)(L)(bipy)0.5] ·0.5DMF}n (1) (H2L = (4,4′-(hexafluoroisopropylidene)bis(benzoic acid) and bipy = 4,4′-bipyridine), has been prepared under solvothermal conditions using flexible dicarboxylate and rigid N-donor co-ligands in the presence of Co(II) ion as the building blocks. The x-ray single-crystal diffraction analysis indicates that 1 possesses a three-dimensional (3D) layer–pillar structure with one-dimensional (1D) metal-carboxylate chain. The Co(II) ions are bridged by L2− to generate a two-dimensional (2D) sheet, which is further pillared by bipy into a 3D framework with {44.62}{45.65}2 topology. In addition, the variable-temperature magnetic susceptibility measurement indicates there exists an anti-ferromagnetic behavior between in the Co(II) ions of 1.
Dual functional ionic liquids as antimicrobials and plasticisers for medical grade PVCs

Two ionic liquids, 1-ethylpyridinium docusate (IL1) and tri-n-butyl(2-hydroxyethyl)phosphonium docusate (IL2), were designed and synthesized with the explicit intention of imparting a combination of plasticization and antimicrobial efficacy when incorporated into medical grade poly(vinyl chloride)s (PVCs). The glass transition (Tg) of PVC can be reduced by >20 °C on addition of 15 wt% IL2. Both IL1 and IL2 leached to varying extents from the base PVC resins rendering the surface of the PVCs hydrophilic. The antimicrobial activity of both ILs is related to the presence and concentration of both cationic and anionic component of the ILs leached from the PVC and inversely proportional to the extent of PVC gelation. Blends of the PVCs with IL1 displayed antibacterial activity against almost all Gram-positive bacteria tested, including coagulase-negative Staphylococci (CoNS) and methicillin-resistant Staphylococcus aureus (MRSA), but not with IL2 at low concentration in contrast to our previous study when high concentrations of IL2 were used. The more hydrophilic IL1 when added to PVC retards biofilm formation.
Factors affecting the dissolution of copper in transformer oils

The effect of addition of acids, peroxides and model N‐containing compounds to the oils on the rate of the copper dissolution from a copper strip into the oils was studied. The oils used were poly‐alpha‐olefin 2 (PAO‐2) and a highly refined naphthenic oil. Acids and peroxides were found to increase the copper dissolution into the oil, whereas the model nitrogen‐containing compounds exhibited a surface passivatory effect. The presence of the oil's partial oxidation products was found to increase the dissolution of the copper into the oil. The reasons for these observations are discussed. The relative contribution of the electrochemical and chemical processes to the copper corrosion is discussed. Copyright © 2008 John Wiley & Sons, Ltd.
New antibacterial pentacyclic triterpenes from Myricaria elegans Royle. (tamariscineae)

Two new pentacyclic triterpenes eleganene-A (1) and eleganene-B (2), along with four known pentacyclic triterpenes betulin (3), ursolic acid (4), erythrodiol (5) and corosolic acid (6) were isolated from the aerial parts of Myricaria elegans. These compounds exhibited significant antibacterial activity. The structure of compounds 1 and 2 were deduced on the basis of their spectral analysis.
Solubility in glassy polymers : Correlations through the nonequilibrium lattice fluid model

The representation of solubility isotherms of gases and vapors in glassy polymers has been analyzed through the use of a thermodynamic model, nonequilibrium lattice fluid, recently introduced. The possible use of the model as a predictive tool for gas solubility in glassy polymers has been discussed in previous works for the special cases in which the polymer density in pseudo-equilibrium conditions is known from experimental measurements. In this paper, a different use of the model is presented in which the polymer density at different sorption conditions is not known from direct experimental measurements and is thus treated as a correlation parameter, following the typical linear dilation isotherm. The solubility isotherms thus obtained by the model have been compared with several experimental data, obtaining a rather satisfactory representation of the sorption isotherms, through use of two fitting parameters, at most.
Non-classical polycrystalline silicon thin-film transistor with embedded block-oxide for suppressing the short channel effect

In this paper, a polycrystalline silicon (polysilicon) thin-film transistor with a block oxide enclosing body, BTFT, is fabricated and investigated. By utilizing the block-oxide structure of thin-film transistors, the BTFT is shown to suppress the short channel effect. This proposed structure is formed by burying self-aligned oxide spacers along the sidewalls of the source and drain junctions, which reduces the P–N junction area, thereby reducing the junction capacitance and leakage current. Measurements demonstrate that the BTFT eliminates the punch-through effect even down to gate lengths of 1.5 µm, whereas the conventional TFT suffers serious short channel effects at this gate length.
In situ Photocurrent Measurements of Thin-Film Semiconductors during Plasma-Enhanced Chemical Vapor Deposition

Time evolutions of photocurrents in hydrogenated amorphous silicon films under plasma-enhanced chemical vapor deposition have been measured. The photocurrent is gradually increased with growth time, and the corresponding photoconductivity is improved. The improvement is dependent on the temperature, and more pronounced during postgrowth annealing. The postgrowth annealing plays an important role in improving the transport of photoexcited carriers.