448 research outputs found

    Electrochemical Capture of CO\u3csub\u3e2\u3c/sub\u3e from Natural Gas using a High-Temperature Ceramic-Carbonate Membrane

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    This study reports the first investigation of using a ceramic-carbonate dual-phase membrane to electrochemically separate CO2 from a simulated natural gas. The CO2 permeation flux density was systematically studied as a function of temperature, CO2 partial pressure and time. As expected, the flux density was observed to increase with temperature and CO2 partial pressure. Long-term stability test showed that flux density experienced an initial performance-improving “break-in” period followed by a slow decay. Post-test microstructural analysis suggested that a gradual loss of carbonate during the test could be the cause of the flux-time behavior observed

    Investigation of a New Flux-Modulated Permanent Magnet Brushless Motor for EVs

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    This paper presents a flux-modulated direct drive (FMDD) motor. The key is to integrate the magnetic gear with the PM motor while removing the gear inner-rotor. Hence, the proposed FMDD motor can achieve the low-speed high-torque output and high-speed compact design requirements as well as high-torque density with a simple structure. The output power equation is analytically derived. By using finite element analysis (FEA), the static characteristics of the proposed motor are obtained. Based on these characteristics, the system mathematical model can be established. Hence, the evaluation of system performances is conducted by computer simulation using the Matlab/Simulink. A prototype is designed and built for experimentation. Experimental results are given to verify the theoretical analysis and simulation

    Depth-varying rupture properties of subduction zone megathrust faults

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    Subduction zone plate boundary megathrust faults accommodate relative plate motions with spatially varying sliding behavior. The 2004 Sumatra-Andaman (M_w 9.2), 2010 Chile (Mw 8.8), and 2011 Tohoku (M_w 9.0) great earthquakes had similar depth variations in seismic wave radiation across their wide rupture zones – coherent teleseismic short-period radiation preferentially emanated from the deeper portion of the megathrusts whereas the largest fault displacements occurred at shallower depths but produced relatively little coherent short-period radiation. We represent these and other depth-varying seismic characteristics with four distinct failure domains extending along the megathrust from the trench to the downdip edge of the seismogenic zone. We designate the portion of the megathrust less than 15 km below the ocean surface as domain A, the region of tsunami earthquakes. From 15 to ∌35 km deep, large earthquake displacements occur over large-scale regions with only modest coherent short-period radiation, in what we designate as domain B. Rupture of smaller isolated megathrust patches dominate in domain C, which extends from ∌35 to 55 km deep. These isolated patches produce bursts of coherent short-period energy both in great ruptures and in smaller, sometimes repeating, moderate-size events. For the 2011 Tohoku earthquake, the sites of coherent teleseismic short-period radiation are close to areas where local strong ground motions originated. Domain D, found at depths of 30–45 km in subduction zones where relatively young oceanic lithosphere is being underthrust with shallow plate dip, is represented by the occurrence of low-frequency earthquakes, seismic tremor, and slow slip events in a transition zone to stable sliding or ductile flow below the seismogenic zone

    Expression of Cripto-1 in the placenta and its role in placenta accreta and placenta previa

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    Objectives: This study Aims to explore the role of placental Cripto-1 in the incidence of an adherent placenta.  Material and methods: Ten pregnant women with placenta increta, 20 pregnant women with placenta previa and 30 women with normal pregnant were enrolled in this study. Reverse transcription-polymerase chain reaction (RT-PCR) was used to measure the expression of Cripto-1 in the placenta while as the analysis of placental Cripto-1 was performed by Western blotting  Results: The placenta increta group showed higher levels of Cripto-1 in the center of the increta as compared to the non-implantation area. The level of placental Cripto-1 in the placenta increta was higher than that of the placenta accrete. The expression of placental Cripto-1 in the placenta increta and placenta previa groups was higher than that of control.  Conclusions: Placental Cripto-1 is involved in the regulation of placental tissue invasion. Additionally, excessive placental growth or penetration into the myometrium are likely to be involved in the development of placenta increta.

    Stabilizing Electrochemical Carbon Capture Membrane with Al\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e Thin-Film Overcoating Synthesized by Chemical Vapor Deposition

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    Development of high-efficiency and cost-effective carbon capture technology is a central element of our effort to battle the global warming and climate change. Here we report that the unique high-flux and high-selectivity of electrochemical silver-carbonate dual-phase membranes can be retained for an extended period of operation by overcoating the surfaces of porous silver matrix with a uniform layer of Al2O3 thin-film derived from chemical vapor deposition

    Fiber-optic refractometer based on a phase-shifted fiber Bragg grating on a side-hole fiber

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    A fiber-optic refractive index (RI) sensor based on a π-phaseshifted fiber-Bragg-grating (πFBG) inscribed on a side-hole fiber is presented. The reflection spectrum of the πFBG features two narrow notches associated with the two polarization modes and the spectral spacing of the notches is used for high-sensitivity RI sensing with little temperature cross-sensitivity. The side-hole fiber maintains its outer diameter and mechanical strength. The side-hole fiber is also naturally integrated into a microfluidic system for convenient sample delivery and reduced sample amount. A novel demodulation method based on laser frequency modulation to enhance the sensor dynamic range is proposed and demonstrated

    A UHPLC-Q-Exactive-Orbitrap-MS method for simultaneous determination of three flavonoids from Parasitic loranthus and their pharmacokinetics in rat plasma

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    Purpose: To develop and validate a chromatographic method for the simultaneous determination of plasma levels of rutin, avicularin and quercitrin using UHPLC-Q-Exactive-Orbitrap-MS. Methods: A sensitive, selective, and reliable UHPLC-Q-Exactive-Orbitrap-MS method was developed and validated for simultaneous determination of the three flavonoids, with puerarin as internal standard (IS). Plasma samples were first treated with methanol, and then acidified using hydrochloric acid (HCl) prior to liquid-liquid extraction with ethyl acetate. The flavonoids were separated on a Syncronis C18 column (100×2.1mm, 1.7 ”m) using an elution gradient of acetonitrile and 0.1 % formic acid at a flow rate of 0.3 mL/min. Results: A linear correlation was obtained for the three flavonoids over the investigated concentration range, with correlation coefficients > 0.9954. The values of validated lower limit of quantification (LLOQ) were 0.68, 1.42 and 2.54 ng/mL for rutin, avicularin and quercitrin, respectively. Intra- and inter-day precision (RSD) were < 10 %, while accuracy (RE) ranged from −3.76 to 4.04 %. Conclusion: The proposed method has been successfully validated and is suitable for studying the pharmacokinetics of the three analytes in rats treated with parasitic loranthus extract (PLE)

    Mechanism of sorafenib resistance associated with ferroptosis in HCC

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    Hepatocellular carcinoma (HCC) is the most familiar primary hepatic malignancy with a poor prognosis. The incidence of HCC and the associated deaths have risen in recent decades. Sorafenib is the first drug to be approved by the Food and Drug Administration (FDA) for routine use in the first-line therapy of patients with advanced HCC. However, only about 30% of patients with HCC will be benefited from sorafenib therapy, and drug resistance typically develops within 6 months. In recent years, the mechanisms of resistance to sorafenib have gained the attention of a growing number of researchers. A promising field of current studies is ferroptosis, which is a novel form of cell death differing from apoptosis, necroptosis, and autophagy. This process is dependent on the accumulation of intracellular iron and reactive oxygen species (ROS). Furthermore, the increase in intracellular iron levels and ROS can be significantly observed in cells resistant to sorafenib. This article reviews the mechanisms of resistance to sorafenib that are related to ferroptosis, evaluates the relationship between ferroptosis and sorafenib resistance, and explores new therapeutic approaches capable of reversing sorafenib resistance in HCC through the modulation of ferroptosis
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