Miracle-dz/UniFAR-FTUs huggingface dataset:
Improved thermal stability and mechanical properties of poly(propylene carbonate) by reactive blending with maleic anhydride

To extend the application of a carbon dioxide sourced environmental friendly polymer: poly (propylene carbonate) (PPC), a small amount of maleic anhydride (MA) was melt blended to end-cap with PPC to improve its thermal stability and mechanical properties. Thermal and mechanical properties of end-capped PPC were investigated by TGA, GPC, mechanical test, and DMA. TGA and titration results demonstrate that PPC can be easily end-capped with MA through simple melt blending. TGA results show that the thermal degradation temperature of PPC could be improved by around 140°C by adding MA. GPC measurement indicates that the molecular weight of PPC can be maintained after blending with MA, where pure PPC experiences a dramatic degradation in molecular weight during melt process. More importantly, the tensile strength of PPC after blending with MA was found to be nearly eight times higher than that of pure PPC. It has approached the mechanical properties of polyolefin polymers, indicating the possibility of replacing polyolefin polymers with PPC for low temperature applications. The method described here could be used to extend the applications of PPC and fight against the well known global warming problem. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Characterization of Mn-modified Pb(Mg1∕3Nb2∕3)O3–PbZrO3–PbTiO3 single crystals for high power broad bandwidth transducers

The effect of MnO2 addition on the dielectric and piezoelectric properties of 0.4Pb(Mg1∕3Nb2∕3)O3–0.25PbZrO3–0.35PbTiO3 single crystals was investigated. Analogous to acceptor doping in “hard” Pb(Zr,Ti)O3 based polycrystalline materials, the Mn doped crystals exhibited enhanced mechanical Q (∼1050) with low dielectric loss (∼0.2%), while maintaining ultrahigh electromechanical coupling k33>90%, inherent in domain engineered single crystals. The effect of acceptor doping was also evident in the build-up of an internal bias (Ei∼1.6kV∕cm), shown by a horizontal offset in the polarization-field behavior. Together with the relatively high usage temperature (TR-T∼140°C), the Mn doped crystals are promising candidates for high power and broad bandwidth transducers.
Use of sewage sludge as fertiliser supplement for Abelmoschus esculentus plants: physiological, biochemical and growth responses

This study was conducted to assess the usefulness of sewage sludge amendment (SSA) at 20 and 40% ratios for lady's finger (Abelmoschus esculentus L. var Varsha uphar) by evaluating the morphological, physiological, biochemical and yield responses. Lipid peroxidation, protein and antioxidant levels increased whereas photosynthetic rate, stomatal conductance and variable fluorescence ratio decreased in plants at higher SSA ratio. Biomass, yield and heavy metal concentration increased significantly at both the amendment ratios. The study suggests that SSA ratio below 20% could be an alternative option of fertilisers for good yield of lady's finger and also a useful management option for this solid waste.
Controlled Field Experiment for Performance Evaluation of Septic Tank Effluent Treatment during Soil Infiltration

Decentralized systems are responsible for treating approximately 25% of the wastewater generated in the United States. The most common decentralized system involves onsite treatment using a septic tank unit followed by dispersal to a subsurface soil infiltration unit where percolation to groundwater occurs. To evaluate the hydraulic and purification processes occurring during soil treatment of septic tank effluent (STE), a field experiment was initiated in the Spring of 2003 with continued operation and monitoring for 2 years. A replicated factorial design ( 22 ) was employed to evaluate three infiltrative surface architectures (ISAs) (open, stone, and synthetic) and two daily hydraulic loading rates (HLRs) (4 and 8 cm∕day ). Pilot-scale test cells were established in native sandy loam soils at the Mines Park Test Site located on the Colorado School of Mines campus in Golden, Colo. STE was obtained from a nearby multifamily apartment building and applied to the test cells daily. Field monitoring included .
Reactivity of the (1Δg)2 and 1Δg states of oxygen produced by direct laser excitation

The (1Δg)2 and 1Δg states of oxygen have been produced by direct laser (He–Ne and Nd–YAG) excitation of oxygen at high pressure dissolved in a suitable solvent, and their reactivities with various substrates investigated. For 9,10-dimethylanthracene and 1,3-diphenylisobenzofuran, the quantum yields for (1Δg)2 excitation are, within experimental error, twice those for 1Δg excitation. In the reactions of 1Δg oxygen with 9,10-dimethylanthracene and tetraphenylcyclopentadienone, both chemical reaction (rate kr) and physical quenching (rate kq) are observed. For 9,10-dimethyl-anthracene, kq/kr∼0.6, and for tetraphenylcyclopentadienone kq/kr∼1.7. With 1,3-diphenyl-isobenzofuran, kq/kr is in the range 0–1. It is shown unambiguously that 1Δg oxygen reacts with two tertiary amines, triethylamine and tropinone, in addition to being quenched. For triethylamine, kq/kr∼11.
Analysis of Acidic Drugs in Swiss Wastewaters

Five acidic drugs (clofibric acid, ibuprofen, ketoprofen, mefenamic acid and diclofenac) were chosen in order to determine their behavior in a sewage treatment plant (STP). An analytical method using solid phase extraction (SPE) and a gas chromatograph coupled with a mass spectrometer (GC-MS) was used. The results show that four pharmaceuticals (clofibric acid, ketoprofen, mefenamic acid and diclofenac) are not well removed by treatment in Swiss STPs. Maximum concentration in the effluent was determined for mefenamic acid up to 1.0 µg/L. This component seems to be relevant in Swiss STPs effluents and we can expect its presence in surface waters.
RAPID DETERMINATION OF CANDESARTAN IN HUMAN PLASMA BY LIQUID CHROMATOGRAPHY TANDEM MASS SPECTROMETRY AND ITS APPLICATION TO A BIOEQUIVALENCE STUDY

A highly sensitive and simple LC-MS/MS method after one-step protein precipitation was developed and validated for determination of candesartan in human plasma using irbesartan as the internal standard (IS). The analyte and IS were separated by a gradient program with a mobile phase consisting of 0.1% formic acid (containing 2 mM ammonium acetate) and methanol at a flow rate of 0.30 mL/min. Detection was performed on a triple quadrupole tandem mass spectrometer via electrospray ionization in the positive ion mode. Selected reaction monitoring using the precursor → product ion combinations of m/z 441.0 → 263.0 and m/z 429.5 → 195.0 were used to quantify candesartan and IS, respectively. The method was validated and proved to be linear, accurate, and precise over the range of 2–200 ng/mL. The lower limit of quantification of candesartan was 2 ng/mL. Validation results indicated that intra-day and inter-day precision was ≤7.34% and ≤8.02%, respectively. The accuracy was from −4.53% to 4.28%. The validated method was successfully applied to a randomized, two-period cross-over bioequivalence study in 20 healthy Chinese volunteers following a single oral dose of 8 mg candesartan cilexetil. The simple, inexpensive protein precipitation and high-throughput method makes it a suitable and valuable tool in the investigation of the clinical pharmacokinetics and bioequivalence.
Mean-square radius of gyration of oligo- and polystyrenes in dilute solutions

Mesure par SAXS de PS atactique dans le cyclohexane a 34 o 5 et deduction du rayon de giration du contour de chaine. Analyse des resultats et des mesures de viscosite a l'aide de la theorie du modele de chaine en serpentin helicoidal (HN)
Growth of Rubrene thin film, spherulites and nanowires on SiO2

The growth of rubrene thin films thermally evaporated under ultra‐high vacuum (UHV) on SiO2 has been investigated by combining atomic force microscopy (AFM), scanning electron microscopy (SEM), and polarized optical microscopy (POM) techniques. A mode of thin film growth in which an amorphous continuous holy film first covers the substrate, and acts afterwards as a template for the nucleation of polycrystalline rubrene spherulites, has been identified. Additionally, rubrene one‐dimensional structures have been observed with a catalyst‐free growth process. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of drying methods on the bioactive components in loquat ( Eriobotrya japonica Lindl.) flowers

The contents of bioactive components such as flavonoids, phenolics, oleanolic acid (OA), ursolic acid (UA), amygdalin, chlorophylls and carotenoids in loquat (Eriobotrya japonicaLindl.) flower with different drying methods were investigated. Results showed that freeze drying can effectively keep the bioactive components, but the drying rate is slow. The microwave drying is rapid, especially at the high power, and the drying effect was better compared with oven drying. The contents of bioactive components varied greatly with drying temperature of oven-dried samples and decreased sharply when the temperature reached 100°C except OA and UA. The effect of natural convective drying was similar to oven drying at 60 and 80°C but with longer time. All the results suggested that microwave drying is more efficient and low-cost, and 60 to 80°C oven drying is recommended to be used under the circumstance of no microwave drying equipment. Key words: Eriobotrya japonica, flower, drying methods, bioactive component.
A POSTSTORAGE BURST OF 6-METHYL-5-HEPTEN-2-ONE (MHO) MAY BE RELATED TO SUPERFICIAL SCALD DEVELOPMENT IN 'CORTLAND' APPLES

Cortland' apples ( Malus ×domestica Borkh.), either untreated or treated with diphenylamine (DPA), were stored for 120 days in air at 0 °C. Peel samples were taken from these fruit immediately after storage, placed in glass vials and incubated for 48 hours, or were isolated from fruit held 2 to 72 hours at 22 °C and incubated in the vials for 2 hours. Emission of 3,7,11-trimethyldodeca-1,3(E),6(E),10-tetraene, known as trans,trans-α-farnesene, or simply α-farnesene, and its oxidation product, MHO, were measured in the vial headspace. α-Farnesene content in the gas phase of vials with peel samples reached a maximal level 2 hours after vials were sealed and was higher in DPA-treated than untreated fruit. The content of α-farnesene in the vial headspace remained unchanged for DPA-treated fruit peel during the 2-day holding period. However, α-farnesene declined rapidly after 10 hours incubation for control samples. Incubating peel samples of control fruit under N2 atmosphere prevented the decline in α-farnesene. The MHO release by the peel of control fruit was rapid during the first 2 hours and continued to increase for 24 hours. In contrast, the MHO released from DPA-treated fruit peels was 8000-fold lower than from peel samples of control fruit. The increase in vapor phase MHO was concomitant with peel browning in controls. For whole fruit held at 22 °C for 2 to 72 hours, cumulative MHO release from fruit peels followed a pattern that was similar to the pattern of superficial scald development in these fruit.
Cloudwater chemistry from ten sites in North America

Cloudwater and rainwater samples were collected at 2.5 m above ground during 2 years from 10 nonurban sites in North America. On the average, cloudwater collected from sites in the eastern United States was more acidic and had higher concentrations of NO/sub 3//sup -/ and SO/sub 4//sup 2 -/ than that at sites in the western United States and Puerto Rico. Of all the sites in the network, cloudwater from Maine had the highest concentrations of these ions. Concentrations of hydrogen ion, nitrate, and sulfate were significantly higher in cloudwater than in rainwater at most sites; however, on a paired-event basis, enrichment factors for cloud vs rain varied greatly. In contrast to distributions of inorganic anions, the concentrations of formate and acetate in cloudwater and rainwater were similar at sites in the western and eastern United States, suggesting that these compounds originated primarily with natural rather than anthropogenic sources.
Computational screening of metallofullerenes for nanoscience: Sr@C74

Density-functional theory calculations are presented for Sr@C74 where C74 is either the isolated pentagon rule (IPR) cage or two cages with a pentagon–pentagon junction. Their relative thermodynamic production yields are evaluated using the calculated terms and it is shown that the IPR-based endohedral prevails at relevant temperatures. The encapsulation Gibbs energy is also combined with the saturated metal pressure as the combined term allows for evaluation of the relative production yields in a metallofullerene series.
Hemicellulose Removal from Hardwood Chips in the Pre-Hydrolysis Step of the Kraft-Based Dissolving Pulp Production Process

Abstract A pre-hydrolysis step to remove hemicelluloses from mixed hardwood chips consisting of maple, aspen, and birch with a ratio of 7:2:1 has been carried out. The effects of parameters on the pre-hydrolysis such as time, temperature, acetic acid addition, and raw material species, were determined. Different sugars, acetic acid, and furfural formation in the pre-hydrolysis liquor were quantified. The results showed that the pre-hydrolysis is a dynamic process, in which the removal of hemicelluloses increased with time while the conversion of extracted hemicelluloses to monosaccharides due to acid hydrolysis increased and part of the xylose was converted to furfural. The maximum temperature was the most critical parameter for hemicelluloses extraction and conversion, and a temperature of 170°C was the optimum for hemicelluloses extraction with relatively low conversion of xylose to furfural. About 11% of the xylan (in both monomeric and oligomeric forms) was removed at 170°C. Due to the presence of a high amount of xylan, birch produced the highest amount of xylose, followed by maple, and then aspen.
The spatial structure of dendritic macromolecules

A low-resolution ab initio shape determination was performed from small-angle neutron and X-ray scattering (SANS and SAXS) curves from solutions of polycarbosilane dendrimers with the three-functional and the four-functional branching centre of the fourth, fifth, sixth, seventh and eighth generations. In all cases, anisometric dendrimer shapes were obtained. The overall shapes of the dendrimers with the three- and four-functional branching centres were oblate ellipsoids of revolution and triaxial ellipsoids, respectively. The restored bead models revealed a pronounced heterogeneity within the dendrimer structure. The density deficit was observed in the central part and close to the periphery of the dendrimers. The fraction of the overall volume of the dendrimers available for solvent penetration was about 0.2-0.3. These results may help in the design of new practical applications of dendrimer macromolecules.
THE PHOTOSYNTHETIC APPARATUS OF Acetabularia mediterranea GROWN UNDER RED OR BLUE LIGHT. BIOPHYSICAL QUANTIFICATION and CHARACTERIZATION OF PHOTOSYSTEM II and ITS CORE COMPONENTS

Abstract— The photosynthetic activity of white light‐grown Acetabularia mediterranea Lamouroux (=A. acetabulum (L.) Silva) decreases under continuous red light to less than 20% within 3 weeks. Subsequent blue light reactivates photosynthesis within a relatively short period of 3 days. In a former publication (Wennicke and Schmid, Plant Physiol.84,1252–1256, 1987) we have shown that the regulated rate limiting step, which is an immediate light driven reaction, is part of photosystem II (PS II). The following biophysical properties of PS II were analyzed in thylakoids isolated from algae grown 3 weeks under either blue or red light with or without subsequent 3 days of blue light illumination: (a) fluorescence induction in the short time domain dominated by QA reduction, (b) the slow fluorescence decline reflecting pheophytin photoaccumulation, (c) absorption changes at 320 and 830 nm under repetitive flash excitation as indicator for the turnover of QA and P680, respectively, (d) oscillation pattern of the oxygen yield by a flash train in dark adapted samples and (e) the binding capacity for atrazine. None of these PS II functions were severely affected, but a minor impairment of20–30% was observed in the thylakoids from algae grown for 3 weeks in red irradiation. The changes do not fully account for the drastic reduction of the electron transport through PS II which was 80% after red light treatment. Therefore, the regulated rate‐limiting step appears to not be mainly located in the PS II core complex itself. It seems likely that the regulation process predominantly comprises the antenna system.
The biocidal and phytochemical properties of leaf extract of Cassia occidentalis linn.

The antibacterial potentials of Cassia occidentalis leaf extracts were investigated against eleven Grampositive and four Gram-negative bacterial isolates. The n-hexane and dichloromethane fractions of the plant extract exhibited appreciable antibacterial action against nine out of the fifteen bacterial isolates tested at a concentration of 20 mg/ml. The zones of inhibition exhibited by n-hexane fraction ranged between 16 and 27 mm while that of dichloromethane fraction ranged between 15 and 28 mm. On the other hand, the zones of inhibition observed for the standard antibiotic, streptomycin ranged between 13 and 30 mm. The minimum inhibitory concentrations exhibited by n-hexane and dichloromethane fractions against the susceptible test isolates ranged between 0.157 and 1.25 mg/ml, respectively. Overall, the two fractions compared favourably with the standard antibiotic, streptomycin used in this study. The phytochemical analysis of the extract revealed the presence of tannins, Saponins, anthraquinones and flavonoids.
Design and implementation of an educational game for teaching chemistry in higher education

New paradigms in education have led to a need for alternative methodologies in the higher education classroom. An educational game on molecular geometry, polarity, and intermolecular forces for engineering students in a general chemistry course was designed and implemented. The results showed that the game was effective in reconstructing students’ knowledge, demonstrating that the games can serve as a useful pedagogical tool in higher education.
Phase Diagrams for Systems Containing Hyperbranched Polymers

Hyperbranched polymers show an outstanding potential for applications ranging from chemistry over nanotechnology to pharmacy. In order to take advantage of this potential, the underlying phase behaviour must be known. From the thermodynamic point of view, the modelling of these phase diagrams is quite challenging, because the thermodynamic properties depend on the architecture of the hyperbranched polymer as well as on the number and kind of present functional end groups. The influence of architecture can be taken into account via the lattice cluster theory (LCT) as an extension of the well-known Flory–Huggins theory. Whereas the Flory–Huggins theory is limited to linear polymer chains, the LCT can be applied to an arbitrary chain architecture. The number and the kind of functional groups can be handled via the Wertheim perturbation theory, applicable for directed forces between the functional groups and the surrounding solvent molecules. The combination of the LCT and the Wertheim theory can be established for the modelling or even prediction of the liquid-liquid equilibria (LLE) of polymer solutions in a single solvent or in a solvent mixture or polymer blends, where the polymer can have an arbitrary structure. The applied theory predicts large demixing regions for mixtures of linear polymers and hyperbranched polymers, as well as for mixtures made from two hyperbranched polymers. The introduction of empty lattice sites permits the theoretical investigation of pressure effects on phase behaviour. The calculated phase diagrams were compared with own experimental data or to experimental data taken from literature.
Permachor Method To Predict Diffusivity Coefficients of Organics in Aqueous Solutions in Flexible Membrane Liners

The diffusion of organic contaminants through plastic Flexible Membrane Liners (FMLs) used in landfills and surface impoundments is an important criteria for evaluating synthetic liner performance. An experimental method has been developed and used to measure diffusivities of organic contaminants commonly found in landfill leachate from an aqucous solution through High Density Polyethylene (HDPE). These data were utilized to evaluate the applicability of the Permachor Method developed by Salame (1961) to predict the diffusion of other organics through FMLs. The Permachor equation can be used in combination with the relationship between the partition coefficients of organics in aqueous organic solution and the octanol-water partition coefficients to predict permeability factors which in turn can be used to calculate the diffusion coefficients of a range of organic chemicals in a plastic FML. Once the relationship between permeability and Permachor are determined for a given plastic FML for a few organic chemicals, the method can be used to predict the permeability of many other organic chemicals. The properties of the plastics and the additives used in its formulation including carbon black appear to influence the diffusion rates.
Synthetic alunites of the potassium-oxonium solid solution series and some other members of the group: synthesis, thermal and X-ray characterization

Stoichiometric end-member alunites of the general formula (A)Al3(SO4)2(OH)6, with A = Na+, K+, Rb+, H3O+, and NH4+ have been synthesized under hydrothermal conditions together with samples of the potassium-oxonium solid solution series over the entire compositional range. A basic gallium sulfate of the alunite type was also synthesized and compared with the oxonium alunite structure. These alunites were characterized by chemical methods, thermal analysis (TA), and powder X-ray diffraction (XRD). The stages of thermal decomposition of these alunites show a common decomposition mechanism for all end-members (two main endothermic decomposition stages). Potassium and rubidium alunite show an additional exothermic step directly in front of the large second endothermic step. The thermogravimetric results confirmed the analytical results on the end-member alunites and reinforce these as synthetic stoichiometric alunites. Alunite, the pure potassium end-member, shows the highest decomposition temperature (490°C) while Na-alunite (480°C) and rubidium alunite (420°C) are less stable followed by ammonium alunite (350°C) and oxonium alunite (200°C). The thermal stability for the members of the solid solution series (H3O)1-XKXAl3(SO4)2(OH) 6 has also been deduced from the thermal analysis. Alunites with different monovalent cations in A site ( i. e. Na+, K+, Rb+, H3O+ and NH4+) are described and the unit-cell parameters for the rhombohedral space group R 3 m (# 166) with hexagonal cell dimensions a and c were determined. The c parameter increases with increasing effective ionic radius of cation in the A site, whereas the a parameter changes to a much lesser degree. The effects of substitution on the unit-cell parameters are rationalized in terms of the structural arrangements of alunite structure. The unit-cell parameters of the basic gallium sulfate have been determined and compared with the unit-cell parameters of oxonium alunite.
Initial Interfacial Tension and Oil Uptake by Deep-fat Fried Foods

Fundamental theory of surface chemistry was utilized to develop an equation for calculating initial interfacial tension between a product and liquid. The relationship provides a practical approach to overcome the complexity of quantitatively determining interfacial tension of foods. The range of interfacial tension between a restructured potato product and the frying medium was 0.01 to 5.23–10−3 N/m. This range was determined using various frying media or additives. A power relationship was found between the initial interfacial tension and uptake of oil or other frying media. A model of capillary rise in porous media was implemented to explain the linear relationship between uptake and contact angle.