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[en] The surface morphology evolution of three thin polystyrene (PS)/polymethyl methacrylate (PMMA) blend films (<70 nm) on SiOx substrates upon annealing were investigated by atomic force microscopy (AFM) and some interesting phenomena were observed. All the spin-coated PS/PMMA blend films were not in thermodynamic equilibrium. For the 67.1 and the 27.2 nm PS/PMMA blend films, owing to the low mobility of the PMMA-rich phase layer at substrate surfaces and interfacial stabilization caused by long-range van der Waals forces of the substrates, the long-lived metastable surface morphologies (the foam-like and the bicontinuous morphologies) were first observed. For the two-dimensional ultrathin PS/PMMA blend film (16.3 nm), the discrete domains of the PS-rich phases upon the PMMA-rich phase layer formed and the secondary phase separation occurred after a longer annealing time
[en] This study evaluated the environmental impact of biodiesel and hydroprocessed renewable jet fuel derived from camelina oil in terms of global warming potential, human health, ecosystem quality, and energy resource consumption. The life cycle inventory is based on production activities in the Canadian Prairies and encompasses activities ranging from agricultural production to oil extraction and fuel conversion. The system expansion method is used in this study to avoid allocation and to credit input energy to co-products associated with the products displaced in the market during camelina oil extraction and fuel processing. This is the preferred allocation method for LCA analysis in the context of most renewable and sustainable energy programs. The results show that greenhouse gas (GHG) emissions from 1 MJ of camelina derived biodiesel ranged from 7.61 to 24.72 g CO2 equivalent and 3.06 to 31.01 kg CO2/MJ equivalent for camelina HRJ fuel. Non-renewable energy consumption for camelina biodiesel ranged from 0.40 to 0.67 MJ/MJ; HRJ fuel ranged from − 0.13 to 0.52 MJ/MJ. Camelina oil as a feedstock for fuel production accounted for the highest contribution to overall environmental performance, demonstrating the importance of reducing environmental burdens during the agricultural production process. Attaining higher seed yield would dramatically lower environmental impacts associated with camelina seed, oil, and fuel production. The lower GHG emissions and energy consumption associated with camelina in comparison with other oilseed derived fuel and petroleum fuel make camelina derived fuel from Canadian Prairies environmentally attractive. - Highlights: • LCA of camelina-derived biodiesel and jet fuel was based on the Canadian Prairies. • Overall, camelina-derived biodiesel had lower GHG emissions than is biojet fuel. • Camelina jet fuel had lower non-renewable energy (NRE) use than its biodiesel. • Camelina biofuels reduced GHG emissions and NRE use relative to petroleum fuel
[en] Highlights: • Anatase TiO_2 nanosheets (NSs) with high surface area have been prepared. • Only one type of surfactant, oleylamine (OM), is used as capping agents. • TiO_2 NSs possess high adsorption capacities MB and high photocatalytic activity. - Abstract: Anatase TiO_2 nanosheets (NSs) with high surface area have been prepared via a one-step thermal decomposition of titanium tetraisopropoxide (TTIP) in oleylamine (OM), and their adsorption capacities and photocatalytic activities are investigated by using methylene blue (MB) and methyl orange (MO) as model pollutants. During the synthesis procedure, only one type of surfactant, oleylamine (OM), is used as capping agents and no other solvents are added. Structure and properties of the TiO_2 NSs were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N_2 adsorption analysis, UV–vis spectrum, X-ray photoelectron spectroscopy (XPS) and Photoluminescence (PL) methods. The results indicate that the TiO_2 NSs possess high surface area up to 378 m"2 g"−"1. The concentration of capping agents is found to be a key factor controlling the morphology and crystalline structure of the product. Adsorption and photodegradation experiments reveal that the prepared TiO_2 NSs possess high adsorption capacities of model pollutants MB and high photocatalytic activity, showing that TiO_2 NSs can be used as efficient pollutant adsorbents and photocatalytic degradation catalysts of MB in wastewater treatment.
[en] The lifetime of the Bc meson is estimated by means of consistent considerations of all of the heavy mesons (B0,B±,Bs,D0,D±,Ds) and the double heavy meson Bc itself as well. The framework, where the nonspectator effects for inclusive decays in terms of the optical theorem are taken into account properly, is adopted, and the parameters appearing in the estimate are treated phenomenologically by global fitting all the existing data for all the heavy mesons. In this estimation, special attention is paid to the masses of the heavy flavors and the bound-state effects as well. The present approach to the problem is meaningful because the numerical results show that the lifetime of the meson Bc can reach to the center value of the experimental observation. Because of the interference between the terms of the QCD correction from penguin diagrams and the main ones c1O1, c2O2, the total width of the meson Bc is enhanced by a factor about 3 - 4% that is different from the other heavy mesons and can be tested experimentally in the future
[en] A series of anatase TiO_2 nanowires (TiO_2-NWs) and Ag-modified TiO_2 nanowires (TiO_2@Ag-NWs) film electrodes with hierarchical 3D nano-network structure are successfully synthesized via a facile hydrothermal process followed by the traditional silver mirror reaction. Successful modification of silver nanoparticles onto the TiO_2-NWs surface is confirmed by X-ray diffraction, scanning electron microscope, transmission electron microscopy with energy-dispersive X-ray analysis, and inductively coupled plasma technique. The electrochemical performances of the TiO_2-NWs and TiO_2@Ag-NWs film electrodes are also investigated in this work. Compared with the pristine TiO_2-NWs, the TiO_2@Ag-NWs nanomaterial exhibits a higher rate capability and better reversibility. At charge/discharge rates of 50, 100, 200, 400, 800, 1600 and 3350 mA/g, the discharge capacities of the TiO_2@Ag-NWs electrodes are 237, 219, 198, 179, 159, 139 and 120 mAh/g, respectively. After 120 cycles at 200 mA/g, its capacity retention was as high as 99.1% with little capacity fading
[en] Highlights: • One-dimensional model of the Tesla turbine is improved and applied in ORC system. • Working fluid properties and system operating conditions impact efficiency. • The influence of turbine efficiency on ORC system performance is evaluated. • Potential of using Tesla turbine in ORC systems is estimated. - Abstract: Organic Rankine Cycle (ORC) system has been proven to be an effective method for the low grade energy utilization. In small scale applications, the Tesla turbine offers an attractive option for the organic expander if an efficient design can be achieved. The Tesla turbine is simple in structure and is easy to be manufactured. This paper improves the one-dimensional model for the Tesla turbine, which adopts a non-dimensional formulation that identifies the dimensionless parameters that dictates the performance features of the turbine. The model is used to predict the efficiency of a Tesla turbine that is applied in a small scale ORC system. The influence of the working fluid properties and the operating conditions on the turbine performance is evaluated. Thermodynamic analysis of the ORC system with different organic working fluids and under various operating conditions is conducted. The simulation results reveal that the ORC system can generate a considerable net power output. Therefore, the Tesla turbine can be regarded as a potential choice to be applied in small scale ORC systems.
[en] Cuprous sulfide (Cu_2S) is attractive electrode material for lithium-ion battery because of its high capacity and energy density. Interestingly, the cycling stability of cuprous sulfide is poor in the carbonate-based electrolytes used in lithium ion battery industry but excellent in ether-based electrolyte. In this study, we have compared the electrochemical performance of commercially available cuprous sulfide in various kinds of carbonate-based electrolytes. Our results show that the specific capacity of Cu_2S electrode fades quickly in cyclic carbonate-based electrolytes, but a much better electrochemical performance in linear carbonate-based electrolytes. In linear carbonate-based electrolyte (1 M LiPF_6 in EMC), it exhibits a specific discharge capacity of 242.8 mAh g"−"1 after 50 cycles with coulombic efficiency of 99.6%. Our study suggests that the poor cycling performance of Cu_2S in cyclic carbonate-based electrolytes is mainly due to the higher reactivity of cyclic carbonates with polysulfides on the surface of the electrode than linear carbonates, which was confirmed for the first time by our experiment studies and theoretical calculation
[en] Three-generation MSW effect in curved spacetime is studied and a brief discussion on the gravitational correction to the neutrino self-energy is given. The modified mixing parameters and corresponding conversion probabilities of neutrinos after traveling through celestial objects of constant densities are obtained. The method to distinguish between the normal hierarchy and inverted hierarchy is discussed in this framework. Due to the gravitational redshift of energy, in some extreme situations, the resonance energy of neutrinos might be shifted noticeably and the gravitational effect on the self-energy of neutrino becomes significant at the vicinities of spacetime singularities.
[en] This paper firstly reports a facile hydrothermal method to prepare CuFeS_2 spike-like nanorods as a promising anode material for lithium ion batteries. When being evaluated as an anode material in traditional carbonate-based (EC/DEC/DMC) and ether-based (DOL/DME) electrolytes, it's found that the type of the electrolytes plays a key role in contribution to the electrochemical performance. The CuFeS_2 binary mental sulfide material has initial discharge capacities of 632.6 mAh/g in the carbonate-based electrolyte and 674.9 mAh/g in the other at the rate of 0.2 C. After 50 circles, the discharge capacity decays severely, down to 64.3 mAh/g while the one performed in the ether-based electrolyte still possesses a capacity of 425.3 mAh/g, whose capacity retention is far more higher. Besides, an outstanding rate capability (∼190 mAh/g) can be obtained at a high rate of 10 C in the ether-based electrolyte, which is indicative of becoming promising anode materials for high-rate lithium batteries
[en] In the past 20 years, with the utilization of nuclear technology in China, air cleaning techniques were developed to prevent the environment from pollution caused by radioactive materials and to ensure the safety of occupational personnel. The technical developments involve many fields including the manufacture of filter media and adsorbents; the application of filters and iodine adsorbers and the testing of them; the improvement of instruments and methods for aerosol concentration measurement; the retention of radioactive noble gases; and others. As nuclear power stations are to be built in China, nuclear air cleaning will be advancing more rapidly. Many programs have been scheduled, such as producing other types of adsorbers, moisture separators, nuclear grade HEPA filters that have excellent performance to resist adverse circumstances, and in-place testing for units of ventilation systems in nuclear facilities. These programs are discussed