90 research outputs found

    Characteristics of hemp radiation field on typical transport aircraft with frequency sweep method

    Get PDF
    This paper presents characteristics of the HEMP radiation field on a typical transport aircraft using the frequency sweep method. Firstly, the characteristics of the HEMP field are analyzed. Then, various parameters including the electric field strength and magnetic field strength distribution are calculated using Altair FEKO software. Afterwards, the electric field strength distributions of three layers (top layer, inner layer and bottom layer) are calculated and analyzed. The results indicate that the HEMP induced field is affected by the aircraft body. The induced electric field strength E(t) varies greatly at different positions. Nevertheless, the peak value of E(t) is usually greater than the initial peak value of electric field strength E0_{0}. Such a study can provide guidance and insight into the protection design of the HEMP of the aircraft

    Data-Driven Machine Learning for Fault Detection and Diagnosis in Nuclear Power Plants: A Review

    Get PDF
    Data-driven machine learning (DDML) methods for the fault diagnosis and detection (FDD) in the nuclear power plant (NPP) are of emerging interest in the recent years. However, there still lacks research on comprehensive reviewing the state-of-the-art progress on the DDML for the FDD in the NPP. In this review, the classifications, principles, and characteristics of the DDML are firstly introduced, which include the supervised learning type, unsupervised learning type, and so on. Then, the latest applications of the DDML for the FDD, which consist of the reactor system, reactor component, and reactor condition monitoring are illustrated, which can better predict the NPP behaviors. Lastly, the future development of the DDML for the FDD in the NPP is concluded

    Evaluation on coupling of wall boiling and population balance models for vertical gas-liquid Subcooled boiling flow of first loop of nuclear power plant

    Get PDF
    An accurate prediction of the interphase behaviors of the vertical gas-liquid subcooled boiling flow is meaningful for the first loop of a nuclear power plant (NPP). Therefore, the interphase behaviors including the bubble size distribution in the first loop of the NPP are analyzed, evaluated, and validated using various wall boiling models coupled with the population balance model (PBM) kernels in this paper. Firstly, nondimensional numbers of the first loop of the NPP and DEBORA (Development of Borehole Seals for High-Level Radioactive Waste) experiment test cases are analyzed with approximation. Secondly, five active nucleation site density models Nn_{n} coupled with the PBM kernel combination, four kernel combinations (C1~C4) with the Nn_{n} models are calculated and analyzed. Lastly, various behaviors including the bubble size distribution Sauter mean diameter (SMD) dp_{p}, void fraction α, gas superficial velocity jg_{g}, and liquid superficial velocity ji_{i} are compared and validated with the experimental data of the DEBORA-1 (P = 2.62 MPa). The results indicate that the two Nn models are suitable for the calculations of thefirst loop of the nuclear power plant. For instance, for the bubble size distribution SMD dp_{p}, the specified Nn_{n} model with C1 (maximum relative error 9.63%) has relatively better behaviors for the first loop of the NPP. Especially, the combination C1 is applicable for the calculation of the bubble size distribution dp_{p}, void fraction α and liquid superficial velocity ji_{i} while C4 is suitable for the calculation of the gas superficial velocity jg_{g}. These results can provide guidance for the numerical computation of the subcooled boiling flow in the first loop of the NPP

    Singlet Oxygen Generation on Porous Superhydrophobic Surfaces: Effect of Gas Flow and Sensitizer Wetting on Trapping Efficiency

    Full text link
    We describe physical-organic studies of singlet oxygen generation and transport into an aqueous solution supported on superhydrophobic surfaces on which silicon–phthalocyanine (Pc) particles are immobilized. Singlet oxygen (1O2) was trapped by a water-soluble anthracene compound and monitored in situ using a UV–vis spectrometer. When oxygen flows through the porous superhydrophobic surface, singlet oxygen generated in the plastron (i.e., the gas layer beneath the liquid) is transported into the solution within gas bubbles, thereby increasing the liquid–gas surface area over which singlet oxygen can be trapped. Higher photooxidation rates were achieved in flowing oxygen, as compared to when the gas in the plastron was static. Superhydrophobic surfaces were also synthesized so that the Pc particles were located in contact with, or isolated from, the aqueous solution to evaluate the relative effectiveness of singlet oxygen generated in solution and the gas phase, respectively; singlet oxygen generated on particles wetted by the solution was trapped more efficiently than singlet oxygen generated in the plastron, even in the presence of flowing oxygen gas. A mechanism is proposed that explains how Pc particle wetting, plastron gas composition and flow rate as well as gas saturation of the aqueous solution affect singlet oxygen trapping efficiency. These stable superhydrophobic surfaces, which can physically isolate the photosensitizer particles from the solution may be of practical importance for delivering singlet oxygen for water purification and medical devices

    Rice Soluble Starch Synthase I: Allelic Variation, Expression, Function, and Interaction With Waxy

    Get PDF
    Starch, which is composed of amylose and amylopectin, is the key determinant of rice quality. Amylose is regulated by the Waxy (Wx) gene, whereas amylopectin is coordinated by various enzymes including eight soluble starch synthases (SSSs), of which SSSI accounts for ∼70% of the total SSS activity in cereal endosperm. Although great progress has been made in understanding SSSI gene expression and function, allelic variation and its effects on gene expression, rice physicochemical properties and qualities, and interactions with the Wx gene remain unclear. Herein, SSSI nucleotide polymorphisms were analyzed in 165 rice varieties using five distinct molecular markers, three of which reside in an SSSI promoter and might account for a higher expression of the SSSIi allele in indica ssp. than of the SSSIj allele in japonica ssp. The results of SSSI promoter-Beta-Glucuronidase (β-GUS) analysis were consistent with the expression results. Moreover, analysis of near isogenic lines (NILs) in the Nipponbare (Nip) background showed that Nip (SSSIi) and Nip (SSSIj) differed in their thermal properties, gel consistency (GC), and granule crystal structure. Knockdown of SSSI expression using the SSSI-RNA interference (RNAi) construct in both japonica and indica backgrounds caused consistent changes in most tested physicochemical characteristics except GC. Moreover, taste value analysis (TVA) showed that introduction of the SSSI allele in indica or knockdown of SSSI expression in japonica cultivars significantly reduced the comprehensive taste value, which was consistent with the superior taste of japonica against indica. Furthermore, to test the potential interaction between SSSI and different Wx alleles, three NILs within the Wx locus were generated in the indica cv. Longtefu (LTF) background, which were designated as LTF (Wxa), LTF (Wxb), and LTF (wx). The SSSI-RNAi construct was also introduced into these three NILs, and physiochemical analysis confirmed that the knockdown of SSSI significantly increased the rice apparent amylose content (AAC) only in the Wxa and Wxb background and caused different changes in GC in the NILs. Therefore, the effect of SSSI variation on rice quality also depends on its crosstalk with other factors, especially the Wx gene. These findings provide fundamental knowledge for future breeding of rice with premium eating and cooking qualities

    A UPLC-MS/MS method for simultaneous determination of tiamulin and its metabolites in Crucian carp (Carassius carassius): an in vivo metabolism and tissue distribution study

    Get PDF
    Tiamulin (TML) has been studied and analyzed in pigs, cattle, chickens, ducks, and other domestic animals, however, its metabolic state in fish has not been well explored. This study investigated TML metabolism in Crucian carp (Carassius carassius). After intraperitoneal injection of TML into Crucian carp, ultra-high performance liquid chromatography with quadrupole and time-of-flight mass spectrometry (UPLC/Q-TOF MS) analysis, was conducted to identify TML metabolites. The UPLC/Q-TOF MS analysis and the relative molecular mass of the metabolites obtained from related literature identified five metabolites in Crucian carp. These metabolites were M1 (510.2908, C28H48NO5S+), M2 (510.2908, C28H48NO5S+), M3 (466.2750, C26H44NO4S+), M4 (482.2663, C26H44NO5S+), and M5 (482.2663, C26H44NO5S+). The enrichment and metabolism of TML and its metabolites in Crucian carp were investigated using the drug bath method combined with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). TML exhibited an overall trend of an initial increase followed by a decrease. Moreover, the drug enrichment rate was fast and reached saturation after two days. The bioconcentration factor of TML in Crucian carp was 3.01. However, the drug had a slow elimination rate, with its complete metabolism occurring after 20 days

    Superhydrophobic surfaces as a source of airborne singlet oxygen through free space for photodynamic therapy

    Get PDF
    A superhydrophobic (SH) sandwich system has been developed to enable "contact-free" airborne singlet oxygen (1O2) delivery to a water droplet. The contact-free feature means that the sensitizer is physically separated from the droplet, which presents opportunities for photodynamic therapy (PDT). Trapping of airborne 1O2 in a H2O droplet residing on a lower SH surface was monitored with 9,10-anthracene dipropionate dianion by varying distances to an upper 1O2-generating surface. Short distances of 20 μm efficiently delivered airborne 1O2 to the droplet in single-digit picomolar steady-state concentrations. Delivery decreases linearly with distance, but 50% of the 1O2 steady-state concentration is trapped at a distance of 300 μm from the generating surface. The 1270 nm luminescence intensity was measured within the SH sandwich system, confirming the presence of airborne 1O2. Physical quenching of 1O2 to ground-state 3O2 by the water droplet itself and both physical and chemical quenching of 1O2 by the water droplet containing the trap 9,10-anthracene dipropionate dianion are observed. Unlike a majority of work in the field of PDT with dissolved sensitizers, where 1O2 diffuses short (hundreds of nanometers) distances, we show the delivery of airborne 1O2 via a superhydrophobic surface is effective through air in tenths of millimeters distances to oxidize an organic compound in water. Our results provide not only potential relevance to PDT but also surface bacterial inactivation processes.Fil: Aebisher, David. University Of Rzeszow; PoloniaFil: Bartusik-Aebisher, Dorota. University Of Rzeszow; PoloniaFil: Belh, Sarah J.. City University of New York; Estados UnidosFil: Ghosh, Goutam. City University of New York; Estados UnidosFil: Durantini, Andres Matías. Universidad Nacional de Río Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; ArgentinaFil: Liu, Yang. City University of New York; Estados UnidosFil: Xu, QianFeng. City University of New York; Estados UnidosFil: Lyons, Alan M.. City University of New York; Estados UnidosFil: Greer, Alexander. City University of New York; Estados Unido

    The influence of African swine fever information on consumers’ preference of pork attributes and pork purchase

    No full text
    This paper uses a randomized survey instrument to study the impact of African Swine Fever (ASF) information on Chinese consumers’ preference for pork attributes and purchases during the recent peak of the ASF pandemic in 2019. We study consumers’ preference for pork attributes including brand, meat texture and taste, quality safety assurance, and traceability under different information treatments. Results show that the willingness to pay (WTP) for quality safety assurance is the highest, followed by brands and traceability systems, and the WTP is lowest for good taste. We show that providing detailed ASF information substantially changes consumer preference by altering the relative importance of pork attributes and price sensitivity, which enables consumers to focus more on safety-related attributes while paying less attention to price and taste attributes. Furthermore, we find that a higher belief in the future of ASF occurrence reduces the frequency of purchases marginally but does not significantly influence for amount per purchase and the total purchase amount

    Evaluation on Coupling of Wall Boiling and Population Balance Models for Vertical Gas-Liquid Subcooled Boiling Flow of First Loop of Nuclear Power Plant

    No full text
    An accurate prediction of the interphase behaviors of the vertical gas-liquid subcooled boiling flow is meaningful for the first loop of a nuclear power plant (NPP). Therefore, the interphase behaviors including the bubble size distribution in the first loop of the NPP are analyzed, evaluated, and validated using various wall boiling models coupled with the population balance model (PBM) kernels in this paper. Firstly, nondimensional numbers of the first loop of the NPP and DEBORA (Development of Borehole Seals for High-Level Radioactive Waste) experiment test cases are analyzed with approximation. Secondly, five active nucleation site density models Nn coupled with the PBM kernel combination, four kernel combinations (C1~C4) with the Nn models are calculated and analyzed. Lastly, various behaviors including the bubble size distribution Sauter mean diameter (SMD) dp, void fraction α, gas superficial velocity jg, and liquid superficial velocity jl are compared and validated with the experimental data of the DEBORA-1 (P = 2.62 MPa). The results indicate that the two Nn models are suitable for the calculations of thefirst loop of the nuclear power plant. For instance, for the bubble size distribution SMD dp, the specified Nn model with C1 (maximum relative error 9.63%) has relatively better behaviors for the first loop of the NPP. Especially, the combination C1 is applicable for the calculation of the bubble size distribution dp, void fraction α and liquid superficial velocity jl while C4 is suitable for the calculation of the gas superficial velocity jg. These results can provide guidance for the numerical computation of the subcooled boiling flow in the first loop of the NPP
    • …
    corecore