Miracle-dz/UniFAR-FTUs huggingface dataset:
One‐Step Synthesis of β‐Cyclodextrin Functionalized Graphene/Ag Nanocomposite and Its Application in Sensitive Determination of 4‐Nitrophenol

β-Cyclodextrin functionalized graphene/Ag nanocomposite (β-CD/GN/Ag) was prepared via a one-step microwave treatment of a mixture of graphene oxide and AgNO3. β-CD/GN/Ag was employed as an enhanced element for the sensitive determination of 4-nitrophenol. A wide linear response to 4-nitrophenol in the concentration ranges of 1.0×10−8–1.0×10−7 mol/L, and 1.0×10−7–1.5×10−3 mol/L was achieved, with a low detection limit of 8.9×10−10 mol/L (S/N=3). The mechanism and the heterogeneous electron transfer kinetics of the 4-nitrophenol reduction were discussed according to the rotating disk electrode experiments. Furthermore, the sensing platform has been applied to the determination of 4-nitrophenol in real samples.
Enterobacter sakazakii survives spray drying

Four strains of Enterobacter sakazakii were inoculated into 35% reconstituted skim milk at 10 7 and 10 2 cfu/g dry wt. After spray-drying in a Buchi mini spray drier (inlet 160°C and outlet 90°C), the resulting powders were analysed for E. sakazakii by enrichment and enumeration. In all cases, E. sakazakii survived the spray drying process and were detected in the powders with a low inoculum and enumerated in all the powders with the high inoculum for at least 12 weeks. The results emphasize that the controls in place to prevent E. sakazakii from getting to the spray drier are essential.
Determination of uranium and thorium in basalts and uranium in aqueous solution by inductively coupled plasma mass spectrometry

Methods are described for the simultaneous determination of uranium and thorium in basaltic rocks at concentrations from mg kg–1(ppm) to µg kg–1(ppb) levels and for uranium in solution at femtogram levels. The technique for basalts does not require preconcentration and samples are taken into solution using a conventional rapid acid digestion method. The results obtained agree, in general, within 10% of published values for eight basalt reference materials. In addition, optimum conditions with respect to acidic media and storage vessel were ascertained as 5% HNO3 and high-density polyethylene, respectively. The method is applicable to a wide range of silicate rocks and other geological materials. For the determination of uranium at sub-ng ml–1 concentrations, such as occur in natural waters, sample introduction by electrothermal vaporization was investigated using several matrices. Complexation of uranium with ethylenediaminetetraacetic acid (EDTA) prior to analysis proved successful at levels down to 0.5 fg ml–1. Routine determination of such low concentrations is thus feasible.
The nonlinear absorption of carbon quantum dots under the picosecond laser pulse

Using Z-scan technique to investigate the nonlinear absorption characteristics of carbon quantum dots (CDs) under the picosecond laser pulse with the wavelength of 532 nm, which the CDs’ types were same particle size of different solvent and same solvent of different particle sizes. The experimental results showed that the nonlinear absorption of water-soluble CDs of 3.9 nm was saturated absorption, and oil-soluble CDs’ was reverse saturable absorption for the same particle size, their nonlinear absorption coefficients were -2.09×10-12 m/W and 6.9×10-12 m/W, respectively; the nonlinear absorption of water-soluble CDs of 4.8 nm was reverse saturable absorption, and oil-soluble CDs’ was saturated absorption for same particle size, their nonlinear absorption coefficients were 1.9×10-12 m/W and -1.3×10-12 m/W, respectively. The experimental results indicate that the nonlinear absorptions of CDs are mainly influenced by the solvent effect and quantum size effect in the same.
Alkali and alkaline-earth metal complexes with tetraoxa[8]circulene sheet: a computational study by DFT and QTAIM methods

A series of alkali and alkaline-earth metal ion complexes with the tetraoxa[8]circulene sheet which possess single- and double-decker structure has been designed and studied by the DFT computational method. Bader's topological analysis of the electron density distribution function has been also performed for the studied complexes with the aim to determine their peculiar electronic features. The obtained computational results indicate the definite selectivity in respect to complexation of the s-block metal ions with the tetraoxa[8]circulene-formed nanopores of various sizes. The coordination bonds of the s-block metal centers with the neighbouring oxygen atoms in the studied complexes possess predominantly ionic nature and can be interpreted as low-covalence closed-shell interactions. The total complexation energy for the studied systems has been estimated to be in a wide range of 9–60 kcal mol−1 which indicates their different stability depending on the nanopore size and metal ion radii. For these reasons the synthesis of the tetraoxa[8]circulene sheets is an important task because of their potential applications as biomimetic-type nanopores representing synthetic ionic channels.
Novel chiral thiazoline‐containing N―O ligands in the asymmetric addition of diethylzinc to aldehydes: substituent effect on the enantioselectivity

Several novel chiral thiazoline primary and tertiary alcohols were easily synthesized from commercially available l-cysteine in three steps and with high yield. These ligands were subsequently applied to the asymmetric addition of diethylzinc (Et2Zn) to various aldehydes. Products with S configuration were obtained when thiazoline-containing tertiary alcohol ligands were used as catalysts. The primary alcohol induced corresponding products with R configuration in 68% enantiomeric excess, which was a higher value relative to other N―O ligands possessing a primary alcohol unit in the literature. Furthermore, a plausible transition state model was proposed to explain the observed enantioselectivities. Copyright © 2012 John Wiley & Sons, Ltd.
Palladium nanoparticles on polysaccharide-derived mesoporous materials and their catalytic performance in C–C coupling reactions

Palladium nanoparticles were successfully prepared using porous materials derived from starch as support media. The nanoparticle size distribution was controllable by selection of the preparation solvent. Materials were characterised and catalytically tested in various C–C coupling reactions, exhibiting excellent catalytic activities in the microwave-assisted Heck, Suzuki and Sonogashira reactions. The palladium-supported materials were also reusable, preserving their catalytic activities after four reuses.
Molecular dynamics simulation of liquid water under the influence of an external electric field

Molecular dynamics simulations of liquid water were performed at 258K and a density of 1.0 g/cm3 under various applied external electric field, ranging 0∼1010 V/m. The influence of external field on structural and dynamical properties of water was investigated. The simple point charge (SPC) model is used for water molecules. An enhancement of the water hydrogen bond structure with increasing strength of the electric field has been deduced from the radial distribution functions and the analysis of hydrogen bonds structure. With increasing field strength, water system has a more perfect structure, which is similar to ice structure. However, the electrofreezing phenomenon of liquid water has not been detected since the self-diffusion coefficient was very large. The self-diffusion coefficient decreases remarkably with increasing strength of electric field and the self-diffusion coefficient is anisotropic.
Aza‐Baylis–Hillman Reactions and Their Synthetic Applications

Aza-Baylis-Hillman reactions have attracted much attention over the past. decade. This review concentrates on discussion of the origins of and progress in aza-Baylis-Hillman reactions, including the development of catalysts and substrate scopes, mechanistic study, asymmetric reactions, and. further transformations of the products. ((c) Wiley-VCH Verlag GmbH & Co.
A Study on the Biodegradability of Polyethylene Terephthalate Fiber and Diethylene Glycol Terephthalate

The degradation of diethylene glycol tereph- thalate (DTP) and polyethylene terephthalate fiber (PET fi- ber) by microbes and lipase was studied. The HPLC method was used to determine the degradation ratio and degrada- tion rule of DTP. Greater than 90% DTP was degraded by microbes in 24 days and 40% by lipase in 24 h. The degra- dation of DTP can be described by the first-order reaction model. Although the biodegradation ratio of PET fiber was still weak, we demonstrated with SEM micrographs and HPLC analysis that microbes and lipase could act on the PET fiber and there were some cracks on the surface of the fiber. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1089 -1096, 2004
Novel applications of locally sourced montmorillonite (MMT) clay as a disintegrant in the formulation of pharmaceutical product

This work explores the application of a locally sourced raw material, montmorillonite (MMT) clay, as a disintegrant in the formulation of an analgesic pharmaceutical product - paracetamol. The raw MMT was refined and treated with 0.IM NaCl to yield sodium montmorillonite (NaMMT) and the powder properties established in this work were compared with those of purified kaolinite (KO) clay and a reference standard disintegrant – maize starch (MS). Separately, the NaMMT, KO and MS powders were employed as disintegrants to compound paracetamol tablets. Some of the physical properties of the tablets were determined. Results of some powder properties showed that NaMMT and KO had superior angles of repose (40.20o and 34.40o, respectively) compared with the reference standard disintegrant MS (56.00%). Sodium montmorillonite (NaMMT) showed better swelling capacity (1.81) than both KO and MS (1.40 and 1.56, respectively), while MS and NaMMT exhibited comparable water retention capacity (3.04% and 2.90%, respectively). The porosity of MS (31.94%) was only slightly better than that of NaMMT (30.00%). For the physical properties of the tablets, the dissolution characteristic of NaMMT was slightly better than that of MS: for example, the percentage amount of 15% NaMMT and MS dissolved in 0.1M HCl solution at 30minutes duration were 75.40% and 74.10%, respectively; and at 50 minutes duration, it was 85.10% and 82.10%, respectively. On the other hand, the disintegration property of MS (1.54min) was slightly better than that of NaMMT (2.10min). Kaolinite (KO) failed both the dissolution and integration tests, with only 0.31% dissolving even after 1hr and requiring more than 30min to disintegrate. The friability and hardness tests showed that NaMMT was superior to both MS and KO. Overall, the sodium montmorillonite (NaMMT) was found to hold strong prospect as a disintegrant in the formulation and compounding of certain solid, compact pharmaceutical dosages. Keywords : Compact dosages, disintegrants, local raw material, montmorillonite clay, pharmaceutics.
Bromine residues in potato and wheat crops grown in soil fumigated with methyl bromide

The bromine content of potato tubers grown in soil fumigated with methyl bromide at 487 and 975 kg/ha (1 lb and 2 lb/100 ft2) averaged 170 and 280 mg/kg of dry weight. Most of the bromine was in the outer layers of the tubers; peeled tubers has less than 100 mg/kg, which remained after boiling. Potato haulm contained 4000 or 6700 mg/kg bromine respectively for the two rates of application. The bromine content of wheat grain grown after potatoes depended on the rate of application of methyl bromide and the time interval between treatment and wheat crop. Wheat grain harvested 31/2 21/2 and 11/2 years after fumigation with methyl bromide at 975 kg/ha had mean bromine contents of 4.5, 15 and 44 mg/kg. but the amounts in grain from plots having the same treatments varied more than two-fold; wheat grain harvested 11/2 years after fumigation at 487 kg/ha contained 23 mg bromine/kg. Wheat yields were unaffected by fumigation.
Functional Enhancement of Metal–Semiconductor–Metal Infrared Photodetectors on Heteroepitaxial SiGe-on-Si Using the Anodic Oxidation/Passivation Method

We report a detailed procedure of using the anodic oxidation to passivate the SiGe film surface in order to enhance the functionality Si/SiGe heterojunction infrared metal–semiconductor–metal (MSM) photodetectors. Specifically, we seek to reduce the magnitude of the dark current while simultaneously boosting the photocurrent to dark current contrast ratio of MSM devices. Our study demonstrated that the current ratio was boosted by more than tenfold compared to that of the device capped with photo-chemical vapor deposited oxide. In addition, a sizable reduction in dark current (more than 3 to 5 orders of magnitude) was achieved for samples prepared at lower current densities compared to that of a sample without being treated with anodic oxidation.
Highly sensitive fluorescence resonance energy transfer (FRET)-based nanosensor for rapid detection of clenbuterol

In this study we investigate the fabrication of a fluorescence resonance energy transfer (FRET)-based nanosensor for the detection of clenbuterol. The nanosensor consists of CdTe quantum dots coated by clenbuterol recognizable agent naphthol and diazotized clenbuterol. Changes in maximal photoluminescent intensities of the nanosensor were utilized to measure clenbuterol concentrations. The maximal photoluminescent intensities of the nanosensor were found to decrease with increasing clenbuterol concentrations, following a linear correlation. We have successfully fabricated a nanosensor for detection of clenbuterol with sensitivity up to 10 pg ml−1.
Highly efficient and durable dye-sensitized solar cells based on a wet-laid PET membrane electrolyte

Polyethylene terephthalate (PET), a commonly used textile fiber, was used in the form of a wet-laid non-woven fabric as a matrix for electrolytes in dye-sensitized solar cells (DSSCs). Also functioning as a separator between the photoanode and cathode of a DSSC, this non-woven membrane was prepared by a well-known wet-laid manufacturing process followed by calendaring to reduce the thickness and increase the uniformity of the structure. This membrane can better absorb the electrolyte turning into a quasi-solid, providing excellent interfacial contact between both electrodes of the DSSC and preventing a short circuit. An optimized membrane provides a better and more desirable structure for ionic conductivity, resulting in the improvement of the photovoltaic performance after calendaring. The quasi-solid-state DSSC assembled with an optimized membrane exhibited 10.248% power conversion efficiency (PCE) at 100 mW cm−2. With the aim of increasing the absorbance, the membrane was also plasma-treated with argon and oxygen separately, which resulted in retention of the electrolyte, avoiding its evaporation, and a 15% longer lifetime of the DSSC compared to liquid electrolytes. The morphology of the membrane was studied by field emission scanning electron microscopy, and the photovoltaic properties and impedance spectroscopy of the cells were studied using polarization curves and electrochemical impedance spectroscopy, respectively. The results suggest that this novel membrane can be used in high-efficiency solar cells, increasing their lifetime without compromising the photovoltaic properties.
Thermodynamic calculations using the water to combustibles ratio.

A METHOD is presented that uses the water to combustibles ratio (W/C) introduced by Frew and James to predict more accurately the thermodynamic outcomes from the use of bagasse as a fuel. Key features of the model presented include: mass balance equations; constant pressure specific heat equations of flue gas components; equations for the change in enthalpy of flue gas components between a gas temperature T and an ambient temperature To and in combustion air between To and a preheated air temperature Ta; estimation of enthalpy losses in exhaust flue gas; spreadsheet modelling; discussion of ‘minor losses’; sugar cane technology applications: prediction of steam and power production capacity; calculation of adiabatic combustion temperature; estimation of furnace combustion temperature; implications for boiler process control; and design of dehydration plants. It is suggested that the model is more accurate than methods generally used in the industry, based as it is on more detailed empirical specific heat equations for flue gas component gases and on a more precise application of different latent heat values (i) for water formed by combustion, and (ii) for water present in the fuel.
Dissolution of Fissile Materials Containing Plutonium and Beryllium Metals

Abstract Scrap materials containing plutonium (Pu) metal were dissolved at the Savannah River Site (SRS) as part of a program to disposition nuclear materials during the deactivation of the FB‐Line facility. Some of these items contained both Pu and beryllium (Be) metal as a composite material. The Pu and Be metals were physically separated to minimize the amount of Be associated with the Pu; however, a dissolution flowsheet was required to dissolve small amounts of Be combined with the Pu metal using a dissolving solution containing nitric acid (HNO3) and potassium fluoride (KF). Since the dissolution of Pu metal in HNO3/fluoride (F−) solutions was well understood, the primary focus of the flowsheet development was the dissolution of Be metal. Initially, small‐scale experiments were used to measure the dissolution rate of Be metal foils using conditions effective for the dissolution of Pu metal. The experiments demonstrated that the dissolution rate was nearly independent of the HNO3 concentration over the limited range of investigation and only a moderate to weak function of the F− concentration. The effect of temperature was more pronounced, significantly increasing the dissolution rate between 40 and 105°C. The offgas analysis from three Be metal foil dissolutions demonstrated that the production of hydrogen (H2) was sensitive to the HNO3 concentration, decreasing by a factor of approximately two when the concentration was increased from 4 to 8 M. In subsequent experiments, complete dissolution of Be samples from a Pu/Be composite material was achieved in a 4 M HNO3 solution containing 0.1–0.2 M KF. Gas samples collected during each experiment showed that the maximum H2 generation rate occurred at temperatures below 70–80°C. A Pu metal dissolution experiment was performed using a 4 M HNO3/0.1 M KF solution at 80°C to demonstrate flowsheet conditions developed for the dissolution of Be metal. As the reaction progressed, the rate of dissolution slowed. The decrease in rate was attributed to the complexation of F− by the dissolved Pu. The F− became unavailable to catalyze the dissolution of plutonium oxide (PuO2) formed on the surface of the metal which inhibited the dissolution rate. To compensate for the complexation of F−, an increase in the concentration to 0.15–0.2 M was recommended. Dissolution of the PuO2 was addressed by recommending an 8–10 h dissolution time with an increase in the dissolving temperature (to near boiling) during the final 4–6 h to facilitate the digestion of the solids. Dilution of the H2 concentration below 25% of the lower flammability limit by purging the dissolver with air was also necessary to eliminate the flammability concern.
Scaling up of silverson rotor–stator mixers

In-line rotor–stator mixers are widely applied in industry for the formulation of emulsion products; however, the current understanding of breakage/coalescence in such devices is limited. In this study the effect of rotor speed, flow rate and dispersed phase viscosity on drop size distributions in an industrial and in a lab scale in-line Silverson rotor–stator mixer were investigated. Silicone oils with viscosities of 9.4 and 339 mPa s at 1 wt. % were emulsified in surfactant solution. Sauter mean diameters were correlated with various parameters and it has been found that Weber number is the most appropriate scaling parameter. Energy dissipation rate is a marginally poorer scaling parameter and this term requires prior knowledge of the experimentally determined power constants. Based on these observations it seems sensible to use Weber number as the preferred scaling-up parameter.
A new source of oxygenated organic aerosol and oligomers

Abstract. A large oxygenated organic uptake to aerosols was observed when exposing ambient urban air to inorganic acidic and non-acidic sulfate seed aerosol. For non-acidic seed aerosol the uptake was attributed to the direct dissolution of primary vehicle exhaust gases into the aqueous aerosol fraction, and was correlated to the initial seed sulphate mass. The uptake of primary oxygenated organic gases to aerosols in this study represents a significant amount of organic aerosol (OA) that may be considered primary when compared to that reported for primary organic aerosol (POA), but is considerably more oxygenated (O : C ~ 0.3) than traditional POA. Consequently, a fraction of measured ambient oxygenated OA, which correlates with secondary sulphate, may in fact be of a primary, rather than secondary source. These results represent a new source of oxygenated OA on neutral aerosol and imply that the uptake of primary organic gases will occur in the ambient atmosphere, under dilute conditions, and in the presence of pre-existing SO 4 aerosols which contain water. Conversely, under acidic seed aerosol conditions, oligomer formation was observed with the uptake of organics being enhanced by a factor of three or more compared to neutral aerosols, and in less than 2 min, representing an additional source of SOA to the atmosphere. This resulted in a trajectory in Van Krevelen space towards higher O : C (slope ~ −1.5), despite a lack of continual gas-phase oxidation in this closed system. The results demonstrate that high molecular weight species will form on acidic aerosols at the ambient level and mixture of organic gases, but are otherwise unaffected by subsequent aerosol neutralization, and that aerosol acidity will affect the organic O : C via aerosol-phase reactions. These two processes, forming oxygenated POA under neutral conditions and SOA under acidic conditions can contribute to the total ambient OA mass and the evolution of ambient aerosol O : C ratios. This may be important for properly representing organic aerosol O : C ratios in air quality and climate models.
Calibration of NIR to assess lignin composition (H/G ratio) in maritime pine wood using analytical pyrolysis as the reference method

-hydroxyphenyl (H), guaiacyl (G) and, if detectable(Saito et al. 2005), negligible (Obst and Landucci 1986)amounts of syringyl (S) phenylpropanoid units. Theimportance of lignin composition in terms of H/G ratio insoftwoods for the pulping industry has led to attemptsat genetic modification (MacKay et al. 1999; Wadenba¨cket al. 2004). Nevertheless, very little is known about thenatural variation of lignin composition. The lack of a suit-able method to assess lignin composition in a largenumber of samples can in part explain this situation.Ana-lytical pyrolysis is being increasingly used to assesslignincomposition (Obst and Landucci 1986; Faix et al. 1993;Choi et al. 2001; Rodrigues et al. 2001; Yokoi et al. 2001;Kuroda et al. 2002; del Rio et al. 2005; Meier et al. 2005)but even if time requirements for the analyticalprocedureare well below those involved in wet-chemical analysis(Meier and Faix 1992) it is still demanding when largescreening programs are necessary.The simplicity, rapidity, and high reproducibilityofnear-infrared spectroscopy (NIRS) have widened its use tothe determination of the chemical composition of ligno-cellulosic materials as a substitute for wet-chemistrytechniques (Schwanninger and Hinterstoisser 2001; Gier-linger et al. 2002; Raymond and Schimleck 2002; Schim-leck et al. 2003). The aim of this work was to use analytical pyrolysisdata to develop an NIR method for determining H/Gratios, with a focus on assessment of the naturalvariationof lignin composition in maritime pine wood.