Miracle-dz/UniFAR-FTUs huggingface dataset:
Reduced graphene oxide films fabricated by gel coating and their application as platinum-free counter electrodes of highly efficient iodide/triiodide dye-sensitized solar cells

This paper reports the preparation of reduced graphene oxide (rGO) films through the gel formation of rGO with liquid polyethylene glycol (PEG) of low molecular weight and the application of the rGO films as the platinum (Pt)-free counter electrode of highly efficient iodide/triiodide dye-sensitized solar cells (DSCs). rGO prepared through the reduction of graphene oxide can form physical gels with PEG by mechanical grinding. The rGO sheets form 3-dimensional solid networks in the gels. The rGO–PEG gels are processed into rGO films on substrates with good adhesion by doctor blade and subsequent removal of PEG through heating. The rGO films can effectively catalyze the electrochemical reduction of triiodide and are used as the counter electrode of iodide/triiodide DSCs. The optimal photovoltaic efficiency of DSCs with the rGO counter electrode is 7.19% under AM1.5G illumination (100 mW cm−2), which is only slightly lower than that (7.76%) of control DSCs with Pt prepared by pyrolysis as the counter electrode. This is the highest photovoltaic efficiency observed on the DSCs with iodide/triiodide as the redox couple and graphene as the counter electrode. The rGO films exhibit better stability in catalyzing the electrochemical reduction of triiodide and give rise to better aging stability of DSCs than Pt prepared by pyrolysis. The photovoltaic efficiency of DSCs is strongly dependent on the thickness of the rGO film, and the optimal rGO film thickness is 15 μm. The photovoltaic performance of DSCs is also affected by the method to prepare the rGO–PEG gels. The photovoltaic efficiency is only 6.15% or lower when the rGO–PEG gels are prepared by ultrasonication rather than mechanical grinding. This is attributed to the different morphologies of the rGO films achieved by different methods.
Determination of defect structures in kaolin minerals by high-resolution transmission electron microscopy (HRTEM)

Abstract Near-atomic resolution TEM imaging has been successfully applied to determine the stacking defect structures in kaolin minerals, especially kaolinite. The specimen studied is from the middle stage of the depth-related kaolinite-to-dickite transformation in a sandstone reservoir. Several high-quality images were recorded on films in which the tetrahedral and octahedral positions in the kaolinite unit layers are clearly resolved, despite the obstacle of electron radiation damage. Electron diffraction and high-resolution imaging of dickite showed that few stacking defects exist in this polytype. On the other hand, kaolinite crystals contain a high density of stacking defects. These defects or stacking disorders are formed by a mixture of two kinds of lateral interlayer shifts, t1 (approximately −a/3) and t2(-a/3 + b/3), between adjacent layers. Disorder due to the coexistence of B and C layers (dickite-like stacking sequence) was never observed. These results provide not only an unambiguous settlement for the long -standing controversy of the defect structures in kaolinite, but also a new clue to understanding the kaolinite-to-dickite transformation mechanism.
First-principles structural stability in the strontium–titanium–oxygen system

First principles calculations have been made to theoretically interpret the structural stability of SrTiO3 as a function of pressure or strain. We show that the orthorhombic Pbnm structure is more stable than the ideal perovskite one due to rotations of TiO6 octahedrons at high pressures or deformations of TiO6 octahedrons at low pressures. Such a study is extended to the structural stability of the Ruddlesden–Popper Sr n +1Ti n O3 n +1 phases for n = 1, 2 and 3, in which the lattice constraints are induced by the intercalation of SrO layers in the perovskite structure.
PRODUCTION DES DÉFAUTS PAR IRRADIATION DANS LES SEMI-CONDUCTEURS

The different stages which govern the defect production are described. Emphasis is placed on unresolved problems, such as the determination of the threshold energy for displacement, the mobility of the insterstitials at low temperature, the nature of the damage in highly disordered regions. Electronic mechanisms which could induce or enhance the mobility of interstitialor vacancy-type defects are proposed and discussed.
Reversed phase HPLC determination of tamoxifen in dog plasma and its pharmaco-kinetics after a single oral dose administration

The analytical method developed to evaluate tamoxifen in dog plasma samples was precise, accurate, robust and linear in the range of 5–200 ng/mL. The limits of detection and quantification were 0.981 ng/mL and 2.97 ng/mL, respectively. Besides, the intra-day precision and accuracy variations were 8.78 and 10.16%, respectively. Tamoxifen concentrations were analyzed by combined reversed phase liquid chromatography and UV detection (λ=280 nm). The study was conducted using an open randomized 2-period crossover balanced design with a 1-week washout period between the doses. This simple, rapid and selective method is suitable for pharmacokinetic, bioavailability and bioequivalence studies.
Effects of junction temperature and its variations on the performance of GaN‐based high power flip‐chip LEDs

In this paper, high power flip-chip GaN-based LEDs were fabricated, and then the effects of junction temperature and its variations were investigated. It was found that the optical output decreases seriously with rising temperature. The variations of junction temperature can be achieved to 9 °C at 350 mA in most regions of flip-chip LED except for some hot regions around some electrodes. The combination of screening of quantum confined Stark effect (QCSE) and thermal effect surprisingly makes the peak wavelength constant from 300 mA to 800 mA in electroluminescence spectra. The full-width at half-maximum (FWHM) of emission peak was narrowed by thermal effect in constant current (CC) injection. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Titanium aluminum nitride films: A new alternative to TiN coatings

TiAl films have been produced in various compositions by using the sputter ion plating process. Films sputtered reactively from a target with the composition of TiAl 50:50 at. % have been deposited with a composition of 27.5 at. % Ti, 28.9 at. % Al, and 43.6 at. % N. The crystal structure found was that of sodium chloride with a lattice parameter of 4.20 A; the microhardness such films was found to be HV 2100–2300. The incorporation of Al into the nitride films improves the oxidation resistance as well as the cutting performances of TiAlN coated drills. TiN films start to oxidize at a temperature level of 550 °C, whereas TiAl coatings react with hot air at a temperature of 800 °C severely. TiAlN coated drills have been tested with two different steels and performed better by a factor >2 compared with TiN coated drills.
Analysis of natural aroma and flavor of MD2 pineapple variety (Ananas comosus [L.] Merr.)

Abstract Aroma and flavor profile of MD2 pineapple variety was investigated. Fruits imported from different geographical regions (Costa Rica, Puerto Rico) were labeled as an organic food. Characteristic volatile and non-volatile compounds obtained by hydro-distillation and direct percolation were identified and quantified by gas chromatography-mass spectroscopy (GC/MS). At least 22 components in percolated extract (or 17 in distillate) were detected according to their mass spectra and retention time. Relative concentration of identified substances varied from 547.7 to 1110.0 μg. kg-1. Analysis showed dominance of esters and furanone-derived compounds as major aroma constituents. Most abundant volatiles identified in all samples were methyl 2-methylbutanoate and methyl hexanoate. Relationships between volatile and non-volatile compounds were also studied.
Towards the upper bound of electrochemical performance of ACNT@polyaniline arrays as supercapacitors

A strategy in the rational design of the aligned carbon nanotube @ polyaniline (ACNT@PANI), arrayed on metal foils as supercapacitors, has been demonstrated towards the upper bound of the specific capacitance, namely a high surface area and nanometre thickness of PANI, good accessibility of ions and a low contact resistance. The structure of ACNT@PANI nanoelectrode arrays was investigated and correlated to the surface redox reaction, electronic and ionic transport and thus to the energy and power density of the supercapacitors. The thickness of the PANI film on each ACNT was found the most important parameter, which was optimized to achieve the specific capacitance (∼1100 F g−1) of PANI close to the maximum theoretic value. A prototype supercapacitor was assembled, and a practical application was demonstrated. This device shows a higher specific capacitance, a higher specific power and a lower internal resistance but reduced cost and volume than conventional two-plate supercapacitors, which may provide opportunities for a smarter design of energy storage devices.
Microwave-Assisted Solution Phase Synthesis of Novel 2-{4-[2-(N-Methyl-2-pyridylamino)ethoxy]phenyl}-5-Substituted 1,3,4-Oxadiazole Library

A new series of 2-{4-[2-(N-methyl-2-pyridylamino)ethoxy]phenyl}-5-substituted 1,3,4-oxadiazoles were synthesized by the oxidative cyclization of hydrazones derived from 4-[2-(methylpyridin-2-ylamino)ethoxy]benzaldehyde and aryl hydrazines using chloramine-T as an efficient catalyst. All steps were assisted by microwave irradiation. Microwave enables all these reactions to be simple, rapid, high yielding, and avoid chromatograph purification and led environmentally benign total synthesis of focused oxadiazole library. All the synthesized compounds were isolated in good yield and characterized by 1H NMR, 13C NMR, and elemental analyses. The title compounds represent a novel class of biologically active heterocycles.
An elusive phase transition inNa2RbC60

The ternary Na 2 RbC 60 fulleride is studied by variable-temperature solid-state 13 C and 23 Na NMR spectroscopies; in addition to the well known orientational order/disorder transition, a phase transformation to a low-symmetry phase which likely contains bonded C 60 3- moieties is identified at low temperature for the first time.
Short‐term electric load forecasting using an artificial neural network: case of Northern Vietnam

Short‐term electric load forecasting is an important requirement for electric system operation. This paper employs a feed‐forward neural network with a back‐propagation algorithm for three types of short‐term electric load forecasting: daily peak (valley) load, hourly load and the total load. The forecast has been made for the northern areas of Vietnam using a large set of data on peak load, valley load, hourly load and temperature. The data were used to train and calibrate the artificial neural network, and the calibrated network was used for load forecasting. The results obtained from the model show that the application of neural network to short‐term electric load forecasting problem is very useful with quite accurate results. These results compare well with other similar studies. Copyright © 2004 John Wiley & Sons, Ltd.
Effectiveness test of alginate-derived polymeric surfactants

A series of alginate-derived polymeric surfactants (APSs) with a linear alkyl group (C8, C12, C16) was synthesized by oxidation followed by reductive amination of 2,3-dialdehydic alginate. The products were characterized by measuring IR spectra, NMR spectra, surface tension and critical micelle concentration (cmc). They were also tested for the solubilization of azobenzene and adsorption of heavy metal. In the case of 40% CHO-C8 APSs, the lowest interfacial tension value (31.5 m Nm−1) was obtained at the cmc value of 1.35 g dm−3. The dissolving capacity of 40% CHO-C8 APS towards azobenzene was 27 times greater than that of alginate. The overall cobalt (Co2+) removal efficiency by adsorption using APSs was high compared with that of sodium alginate at pH 3, 5 and 7. Equilibrium aspects of cobalt adsorption onto 10% CHO-APSs were studied, and the results show that APSs had high equilibrium capacities for cobalt uptake, 115.5 mgg−1. © 2002 Society of Chemical Industry
PREPARATION AND CHARACTERIZATION OF POLYCRYSTALLINE MIXED NICKEL ZINC FERRITES FOR DIELECTRIC PROPERTIES AND PRACTICAL APPLICATION

Cobalt substituted Nickel-zinc ferrites of different compositions Ni0.95-xZn0.05CoxFe2O4 and Zn0.95-xNi0.05CoxFe2O4 (where x = 0.00, 0.01, 0.02,0.03, 0.04, 0.05 and 0.06). have been prepared by citrate precursor method involving concerned metals and mixing them in solution state. Parts of the sol-gel powder heated at elevated temperatures were characterized by X-ray diffraction (XRD), Particle size analyser and Scanning Electron Microscope (SEM) to reveal the crystallized single phase structure of the ferrite. Nickel Zinc ferrites are studied for their dielectric and electrical properties upon on the substitution of cobalt. Dielectric constant is found to decreases at lower frequencies and remains constant at higher frequencies, showing the usual dielectric dispersion. The dielectric polarization decrease with increase in frequency and reaches a constant value. The plots of AC conductivity are linear, indicating that the conduction is due to small polarons. A slight decrease in conductivity at certain frequencies is attributed to mixed polaron (small and large) conduction. Room-temperature complex impedance spectra for the samples indicated that size of the semicircle changes with grain size. The dc resistivity (ρdc) increased with the increase of Co 2+ concentration in NZCF and ZNCF ferrites. The values of activation energy(∆ E) in paramagnetic region is found to be greater than those observed in ferromagnetic region. The ∆E and resistivity are found to increase with increase in cobalt content. The ac resistivity decreased with increase in frequency. In the low frequency region ac resistivity is found increasing with change in composition parameter x. Polycrystalline ferrites (NZCF and ZNCF) are good candidates for Hyperthermia tumour therapy.
Measurement of the angular distribution of sputtered neutrals in a planar magnetron geometry

In the low temperature regime (T<0.3Tm), the microstructure of sputtered films is determined predominantly by the mechanisms of self‐shadowing. Shadowing effects are directly related to the angular distribution of incoming sputtered particles. The angular distributions of copper and lead particles sputtered by Ar+ ions in a planar magnetron geometry were measured using a differentially pumped pinhole camera. The pressure in the pinhole camera was lower by a factor of 10 compared to the ambient working gas. Thus it was possible to monitor the angular distribution of the incoming sputter particles for working gas pressures up to 4 Pa. Transparent films of the impinging particles were deposited on semicircular transparent substrates. Their relative thicknesses were measured by optical densitometry, giving a direct representation of the angular distribution at an arbitrarily chosen point of the sputter chamber. A comparison of the measured angular distributions with distributions calculated for the particular.
LEAN BLOWOUT LIMITS AND NOX EMISSIONS OF TURBULENT, LEAN PREMIXED, HYDROGEN-ENRICHED METHANE/AIR FLAMES AT HIGH PRESSURE

Flame stability is a crucial issue in low NOx combustion systems operating at extremely lean conditions. Hydrogen enrichment seems to be a promising option to extend lean blowout limits of natural gas combustion. This experimental study addresses flame stability enhancement and NOx reduction in turbulent, high-pressure, lean premixed methane/air flames in a generic combustor, capable of a wide range of operating conditions. Lean blowout limits (LBO) and NOx emissions are presented for pressures up to 14 bars, bulk velocities in the range of 32–80 m/s, two different preheating temperatures (673 K, 773 K), and a range of fuel mixtures from pure methane to 20% H2 /80% CH4 by volume. The influence of turbulence on LBO limits is discussed, too. In addition to the investigation of perfectly premixed H2 -enriched flames, LBO and NOx are also discussed for hydrogen piloting. Experiments have revealed that a mixture of 20% hydrogen and 80% methane, by volume, can typically extend the lean blowout limit by roughly 10% compared to pure methane. The flame temperature at LBO is approximately 60 K lower resulting in the reduction of NOx concentration by ≈ 35% (0.5 → 0.3 ppm/15% O2 ). Copyright © 2006 by ASME
Versatile Responsive Surfaces via Hybrid Polymers Containing Acetal Side Groups

Two hybrid polymers, poly(methylsilsesquioxane)-poly(2,2-diethoxyethyl acrylate) and poly-(methylsilsesquioxane)-poly(1,3-dioxolan-2-ylmethyl acrylate), were synthesized and used for preparation of stable surface coatings. Their acetal side groups could be functionalized via solution-dipping with different primary amines and hydroxylamines after acidic deprotection and thus allowed for flexible modification of the surface hydrophilicity. Functionalization with a thermo-responsive polymer resulted in a thermo-responsive surface with temperature-dependent contact angles. Further, the two types of acetals showed different stability toward acidic treatment and could be addressed independently.
Temperature effects in bio-P removal

This paper discusses the temperature influence in biological phosphorus removal through literature review and experimental evidence. An SBR (Sequencing Batch Reactor) was operated in an anaerobic-aerobic sequence to cultivate an enriched biological phosphorus removing sludge. The impact of long term temperature changes on the stoichiometry and kinetics of the different processes involved was studied at 20, 15, 10 and 5°C. At 5°C breakthrough of acetate to the aerobic period occurred. It was shown that the stoichiometry of the anaerobic processes was insensitive to long-term temperature changes, whereas the kinetics of the aerobic and anaerobic processes were clearly affected. The aerobic phosphorus uptake rate showed a maximum in the interval between 15 and 20°C. All other anaerobic and aerobic conversion rates increased with increasing temperature. A simplified Arrhenius equation was used to describe the effect of temperature on the reaction rates. It was shown that a prediction of the temperature effect on a full scale biological nutrient removal plant is not a straight forward case because of the different influence of temperature on the subprocesses. All these influences should be accounted for.
Preparation of nanometer-sized poly(methacrylic acid) particles in water-in-oil microemulsions

A water-in-oil microemulsion, water-in-cyclohexane stabilized by poly(ethylene glycol) tert-octylphenyl, was developed to prepare poly(methacrylic acid) (PMAA) particles. Up to 100% conversion of the amphiphilic monomer, methacrylic acid (MAA), which could not be converted to the polymer efficiently in a dioctylsulfosuccinate sodium salt/toluene microemulsion, was achieved. The viscosity-average molecular weight of the PMAA prepared was 1.45 105 g/mol. The effects of some polymerization parameters, including the reaction temperature and the concentrations of the initiator and the monomer, on the polymerization of MAA were investigated. The results showed that the polymerization rate of MAA was slower than that of acrylamide in the microemulsions reported in the literature. The degree of conversion increased with the initiator concentration, reaction temperature, and monomer concentration. However, the stable microemulsions became turbid during the polymerization when the reaction temperature was at 70°C or at a high monomer concentration (40 wt %) The synthesized PMAA particles were spherical and had diameters in the range of 50 nm.
Chemistry of benzobispyrrole-derived squaraines

In the search for a conducting polymers with narrow Energy Band-Gap (Eg), the research focus is centered on increasing the bandwidth of the Highest Occupied Molecular Orbitals (HOMO) or the Lowest Orbital Molecular Orbitals (LUMO) of a conducting polymers through the use of strong electron donor or strong electron acceptor, respectively. In this research, we considered the trend of change in Eg, UV absorption, IR absorption, Density of State (DOS) and Excited state Properties of various forms of Benzobispyrrole-Derived Squaraines using Density Functional Theory (DFT) and Hartree-Fock (HF) methods. The results obtained from various computational methods employed are in good agreement with literature, which observed that the Eg values calculated with ROHF is higher than the expected value, while that calculated with BLYP and SVWN values are about 40 to 50% lower than the expected. The better Eg values in good agreement with expected values are found by hybrid functional B3LYP. However, there is a good correlation in the trend of change in the calculated Eg values of all computational methods with the trend of change in the experimental Eg. Also, DOS, IR Maximum Absorption, Dipole Moment and UV Absorption add meaning to the intrinsic conductivities property of the models.
Nutrients in Amazonian Black Earth from Caxiuanã Region

Dispersion of nutrients in Amazonian black earth (ABE) can provide information on human activities of the inhabitants of the Amazon region. Studies on the pH, available phosphorus (P), organic matter (OM) and the exchangeable cations Ca2 + and Mg2 + were performed on soil samples from horizons A1 and A2 over an area with TPA (north-south and east-west) at a site called Ilha de Terra, located in the Conservation Unit Caxiuana National Forest, Melgaco County, Brazil. The results indicated that the OM and Ca2+ are the ones with greater dispersion. Higher correlations were found between OM-Ca-Mg to near the central area. This leads to the inference that the dispersion geochemistry of MO, Ca, Mg and P in archaeological sites with TPA is related to past human activities.
Effectiveness of Mind Sound Resonance Technique versus Progressive Muscle Relaxation in Common Neck Pain Individuals: A Comparative Study

Background: The main cause of neck pain is tension. During periods of intense anxiety, the muscles tense up dramatically. Muscle tension tightens the muscles, especially in shoulders, back and neck. The more anxiety the individual experience, the more tension may cause significant pain and discomfort. The Conventional conservative methods include non- steroidal Anti-inflammatory drugs, physical measures such as heat, Ultra sound, Manipulations and exercises. Yoga is used to alleviate various types of pain. This is safe and cost-effective intervention which comprises of physical postures, breathing exercises, meditation and relaxation. Although, MSRT has been routinely as component of the integrated approach to Yoga therapy for treatment of neck pain and back pain gave encouraging results. MSRT intervention also led to better reduction in pain, tenderness, disability and state anxiety in patients suffering from chronic neck pain. Method: Individuals having neck pain on VAS 3-7, individuals aged between 18-24 years and willing to participate who understood English language, both males and females were included in the study. 15 participants were given MSRT and 15 participants were given PMR. Both groups were given conventional treatment. Outcome measures used were VAS and NDI. Result: Paired t test was used to compare within groups where p 0.05. Conclusion: The study concluded that both MSRT and PRT were equally effective in reducing pain and improving NDI score.