Mccoynewton2349

In addition, the characteristics of calcined sorbents are analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) methods. Copyright © 2020 American Chemical Society.Manuka honey is a premium food product with unique antimicrobial bioactivity. Concerns with mislabeled manuka honey require robust assays to determine authenticity. Lepteridine is a Leptospermum-specific fluorescent molecule with potential as an authenticity marker. We describe a mass spectrometry-based assay to measure lepteridine based on an isotopically labeled lepteridine standard. Using this assay, lepteridine concentrations in manuka honey samples strongly correlated with concentrations quantitated by either high-performance liquid chromatography-ultraviolet (HPLC-UV) or fluorescence. A derived minimum lepteridine threshold concentration was compared with the New Zealand regulatory definition for manuka honey to determine "manuka honey" authenticity on a set of commercial samples. Both methods effectively distinguished manuka honey from non-manuka honeys. The regulatory definition excludes lepteridine but otherwise includes the quantification of multiple floral markers together with pollen analysis. Our findings suggest that the quantification of lepteridine alone or in combination with leptosperin could be implemented as an effective screening method to identify manuka honey, likely to achieve an outcome similar to the regulatory definition. Copyright © 2020 American Chemical Society.In this paper, the high-temperature/high-pressure triaxial testing system of rocks is used to study the effect of spontaneous fluid imbibition on the formation mechanism of fracture networks, by means of acoustic emission (AE) monitoring and ultrasound measurement. After the water-shale interaction, the rock mechanical parameters such as rock strength, elastic modulus, cohesion, and internal friction angle of shales significantly decrease as the imbibition time increases, indicating that the fluid has a strong influence on the mechanical properties of brittle shales. The stress-strain curves of the wet and dry shales and their AE characteristics are quite different (i) the stress-strain curve of wet shale samples shows multiple fluctuations before macroscopic failure, and its cumulative AE number curve presents a step-like jump many times that corresponds to the local microcracking; (ii) the stress-strain curve of dry shale samples mainly shows the characteristic of linear elastic deformation during early loading, which has less AE event number, and the step-like jump is not observed in all the AE curves. The dry shale only has a large number of AE events until it is close to macroscopic failure. Nuclear magnetic resonance, mineral composition, and microstructure analysis show that Chengkou shale generally develops micro-nanoscale pores with a small pore throat, and thus strong capillary spontaneous absorption occurs. The shale-water interaction includes both chemical and physical effects, which affect the key parameters such as acoustic velocity, frictional force on the surfaces of artificial fracture, fracability, and other mechanical properties. This paper provides new insights to the investigation on the formation mechanism of artificial fracture networks in brittle shales. Copyright © 2020 American Chemical Society.The preparation of reusable and eco-friendly materials from renewable biomass resources such as cellulose is an inevitable choice for sustainable development. In this work, cellulose was dissolved in 7 wt % NaOH/12 wt % urea aqueous solution at -12 °C with rapid stirring. Cellulose microspheres (Cels) were fabricated by a sol-gel transition method. Subsequently, novel magnetic Ag-Fe3O4 nanoparticles (NPs) supported on cellulose microspheres were successfully constructed by an in situ one-pot synthesis. The magnetic cellulose microspheres (MCels) displayed a spherical shape with mesoporous structure and had a narrow particle size distribution (10-20 μm). Many nanopores with a pore diameter of 5-40 nm were observed in MCels. The Ag-Fe3O4 NPs were immobilized by anchoring with the hydroxyl groups on the surface of Cels. MCels were applied as a microreactor to evaluate their catalytic activities. 4-Nitrophenol (4-NP) could be reduced to 4-aminophenol (4-AP) in 5 min, catalyzed by MCels. Moreover, the magnetic microspheres exhibited a small hysteresis loop and low coercivity. Thus, MCels could be quickly gathered in water under a magnetic field in 10 s, as well as almost 9 cycle times, maintaining relatively high catalytic activity. In this work, cellulose matrix as the catalyst support could be biodegraded completely in the environment. It provided a green process for the utilization of biomass in nanocatalytic applications. JKE-1674 Copyright © 2020 American Chemical Society.The sintering process of bone china bodies containing 0, 2, 4, and 6 wt % palygorskite was studied by X-ray diffraction (XRD), differential scanning calorimetry and thermogravimetry (DSC/TG), and dilatometric tests. According to the XRD and DSC/TG results, the increment of palygorskite increased the content of the amorphous phase and reduced the formation temperature of the early liquid phase in the bone china bodies. The shrinkage data showed that the starting sintering temperature and maximum shrinkage temperature of bone china bodies in the stage of liquid-phase sintering decreased by 20 and 15 °C via adding 6 wt % palygorskite, respectively. Also, the maximum shrinkage rose with increasing amount of palygorskite. Moreover, the kinetic analysis of shrinkage data was conducted by the Salem model. The value of the mechanism-characteristic exponent, m, rose from 0.62 to 0.91 by adding 6 wt % palygorskite. In addition, with increasing palygorskite, the value of activation energy, E a, linearly reduced, and the value of rate constant A increased. Copyright © 2020 American Chemical Society.In this paper, blister formation on a lined fluoropolymer-steel substrate's exposure to water and hydrochloride acid solution at different temperatures and temperature gradients was studied. The higher the temperature gradient between the lining and the substrate, the faster the blister will form. In the absence of a temperature gradient, the temperature also affects the formation of blisters. The higher the working environment temperature, the faster the blistering will appear. Even so, the role of temperature gradients in promoting blistering is far greater than that of temperature. The concentration of HCl solution also affects the formation of blisters. Blistering occurs more slowly in high-concentration solutions and water is determined to be the main cause of blister formation. Copyright © 2020 American Chemical Society.A series of magnetic composites of sodium polyacrylate and polyacrylamide copolymer [Fe3O4@SiO2@P(AANa-co-AM)] were prepared. The investigation showed that the adsorption efficiency of Pb(II) was the best when the acrylamide/acrylic acid (AM/AA) mass ratio of composites was 55. Therefore, the composite of this ratio was selected as the adsorbent to systematically adsorb Pb(II) in aqueous solution. Static adsorption of Pb(II) to the magnetic composites in aqueous solutions was investigated by varying the solution pH and the concentration of Pb(II). The adsorption kinetics and isotherms model of Pb(II) on the Fe3O4@SiO2@P(AANa-co-AM) composites followed a pseudo-second-order model and the Langmuir isotherm model, respectively. When the temperatures were 298.15, 308.15, and 318.15 K, the maximum adsorption capacities of Fe3O4@SiO2@P(AANa-co-AM) composites were 237.53, 248.14, and 255.10 mg/g, respectively. The thermodynamic study of adsorption showed that the adsorption of Pb(II) on Fe3O4@SiO2@P(AANa-co-AM) composites was a spontaneous endothermic process. The X-ray photoelectron spectroscopy (XPS) analysis showed that the adsorption of Pb(II) was due to the chelation between -COO- and Pb(II). After four adsorption-desorption cycles, the adsorbent can still maintain a high adsorption capacity. Copyright © 2020 American Chemical Society.In this work, a drug delivery system for perillyl alcohol based on the peptide self-assembly containing 3-(2-benzothiazolyl)-7-(diethylamino)coumarin (C6) as a fluorescent additive is obtained, and its photophysical characteristics as well as its release dynamics were studied by steady-state and time-resolved fluorescence spectroscopy. Results proved the dynamics of drug release from the peptide nanostructures and showed that the system formed by the self-assembled peptide and C6, along with perillyl alcohol, presents unique photophysical properties that can be exploited to generate singlet oxygen (1O2) upon irradiation, which is not achieved by the sole components. Through epifluorescence microscopy combined with time-correlated single photon counting fluorescence spectroscopy, the release mechanism was proven to occur upon peptide structure interconversion, which is controlled by environmental changes. Copyright © 2020 American Chemical Society.Vanillin (4-hydroxy-3-methoxybenzaldehyde) is one of the most widely used food spices. Aimed at bio-vanillin green production, the natural materials were directly catalytically oxidized efficiently in one pot under low O2 pressure (0.035 MPa) in the presence of a non-noble metal oxidation combined catalyst (NiCo2O4/SiO2 nanoparticles), which showed remarkable advantages of a short synthetic route and less industrial waste. The catalytic system showed good universality to many natural substrates with nearly 100% conversion and 86.3% bio-vanillin yield. More importantly, carbon isotope ratio investigations were employed to verify the origin of the organic matter. One hundred percent 14C content of the obtained vanillin was detected, which indicated that it was an efficient method to distinguish the vanillin from biomass or fossil materials. Furthermore, the 13C isotope examination showed effective distinguishing ability for the vanillin from a particular biomass source. The C isotope detection provides an effective method for commercial vanillin identification. Copyright © 2020 American Chemical Society.Fungi play a considerable role in the deterioration of lignocellulose materials, as their activities either affect the esthetic properties or lead to decay of the host materials. The new generation of organic-inorganic preservatives, which are copper-based but chrome- and arsenic-free, is a subject of many research works. Mildew fungus prevention, treatment of affected materials, and their successive conservation are essential to the woodworkers. To prevent degradation and prolong the service life of wood, a sol-gel organic-inorganic procedure was employed in this study. Aluminum sulfate (Al2(SO4)3), copper sulfate (CuSO4·5H2O), and boric acid (H3BO3) were introduced into phosphoric acid (H3PO4) and water glass as an antimildew agent, with different treatment concentrations (0.7, 1.4, and 2%). Wood was inoculated with Aspergillus niger and Trichoderma viride after new treatment based on the inorganic preservative. The changes in wood surface, structural chemistry, and the crystalline structure of the treated wood were examined by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD), respectively.