Abstract Diaminomethylenemalononitrile organocatalysts efficiently promoted the asymmetric direct vinylogous conjugate addition of α‐angelica lactone to ( E )‐ and ( Z )‐benzoyl acrylonitrile derivatives. The synthesized products bear vicinal tertiary and quaternary stereogenic centers with excellent enantioselectivities (up to 98% ee). This report is the first successful example of the stereoselective conjugate addition using ( Z )‐benzoyl acrylonitriles as Michael acceptor.
In order to improve the safety of nuclear power plants, it is necessary to make sure measures against their severe accidents. Especially, in the case of a sodium-cooled fast reactor, there is a possibility that molten core material would be discharged through control rod guide tubes into the inlet coolant plenums beneath the rector cores in the event of a core disruptive accident (CDA). It is important to ensure in-vessel retention that keeps and confines damaged core material in the reactor vessel even if the CDA occurs. In this study, effective cooling of the melt in coolant was confirmed by comparing the experiment and analysis. CDA scenario initiated by a unprotected loss of flow condition , which is a typical cause of core damage, is generally categorized into four phases according to the progression of core-disruptive status, which are the initiating, early-discharge, material-relocation and heat-removal phases for the latest design in Japan. During the material-relocation phase, the molten core material flows down mainly through the control rod guide tube and is discharged into the inlet coolant plenum below the bottom of the core. The discharged molten core material collides with the bottom plate of the inlet plenum. Clarification of the accumulation behavior of molten core material with such a collision on the bottom plate is important to reduce uncertainties in the safety assessment of CDA. In present study, in order to make clear behavior of core melt materials during the CDAs of sodium-cooled fast reactors, analysis was conducted using the SIMMER-III code for melt discharge simulation experiments by Imaizumi et al. in which low-melting-point alloy was discharged into a shallow water pool. As the result, temperature and pressure behaviors during the discharge almost coincided between the analysis and the experiment. Therefore, it can be concluded that the validity of the analysis cell system model was confirmed.
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Lowering the sintering temperature of the BaZr0.8Y0.2O3-δ (BZY) by grinding BZY powder to nano-size particles was studied. BZY nano-slurry was fabricated by a planetary ball-mill. Obtained nano-slurry was coated on a NiO / BZY anode substrate by a spin-coater and sintered at the temperature of 800 to 1000 ℃. Crystal structure and composition of the fabricated electrolyte layer were measured by an X-ray diffractometer (XRD) and an energy dispersive X-ray analyzer (EDX), respectively. Further, morphology of the coating layer was observed by a scanning electron microscope (SEM). As a result, dense transparent layers were obtained by sintering at temperature more than 800 ℃. Thickness of the layers is about 1 μm. The crystal structure and composition of the layers was consistent with that of the raw BZY powder. Therefore, dense thin BZY layers were fabricated on the NiO / BZY anode substrate successfully.
Abstract Purpose This study aimed to investigate the incidence and clinical factors associated with undescended testes (UDT) in patients with congenital diaphragmatic hernia (CDH). Methods We retrospectively reviewed the incidence of UDT in male neonates admitted to our institution and underwent surgery for CDH between January 2006 and December 2022. Patients were divided into two groups based on the presence or absence of UDT, and risk factors for UDT were compared between the two groups. Results Among the 66 male neonates with CDH, 16 (24.2%) developed UDT. Patients with UDT had a significantly smaller gestational age (p = 0.026), lower birth weight (p = 0.042), and lower Apgar score at 1 minute (p = 0.016) than those without UDT. They had a significantly higher incidence of large diaphragmatic defects (p = 0.005), received more patch closures (p = 0.020), had a longer mechanical ventilation period (p = 0.034), and longer hospital stay (p = 0.028). Conclusion Our data indicate a strong correlation between CDH and UDT. In patients with CDH, the incidence of UDT was related not only to patients’ prematurity but also to the large diaphragmatic defect, suggesting that an insufficient increase in intra-abdominal pressure during the foetal period may result in the development of UDT in patients with CDH.
JAEA is now conducting “Fast Reactor Cycle Technology Development (FaCT)” project for commercialization before 2050s. A demonstration reactor for Japan Sodium-cooled Fast Reactor (JSFR) is planned to start operation around 2025. In the FaCT project, conceptual design study on the demonstration reactor has been performed since FY2007 to determine referential reactor specifications for the next stage of design work of licensing and construction study. Plant performance as a demonstration reactor for the 1.5 GWe commercial reactor JSFR is being compared between 750 MWe and 500 MWe plant designs. In this paper, the current status of the conceptual design study for the demonstration reactor plant is summarized.
A gas entrainment (GE) prediction method has been developed to establish design criteria for the largescale sodium-cooled fast reactor (JSFR) systems. The prototype of the GE prediction method was already confirmed to give reasonable gas core lengths by simple calculation procedures. However, for simplification, the surface tension effects were neglected. In this paper, the evaluation accuracy of gas core lengths is improved by introducing the surface tension effects into the prototype GE prediction method. First, the mechanical balance between gravitational, centrifugal, and surface tension forces is considered. Then, the shape of a gas core tip is approximated by a quadratic function. Finally, using the approximated gas core shape, the authors determine the gas core length satisfying the mechanical balance. This improved GE prediction method is validated by analyzing the gas core lengths observed in simple experiments. Results show that the analytical gas core lengths calculated by the improved GE prediction method become shorter in comparison to the prototype GE prediction method, and are in good agreement with the experimental data. In addition, the experimental data under different temperature and surfactant concentration conditions are reproduced by the improved GE prediction method.
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
A gas entrainment (GE) prediction method has been developed to establish design criteria for the largescale sodium-cooled fast reactor (JSFR) systems. The prototype of the GE prediction method was already confirmed to give reasonable gas core lengths by simple calculation procedures. However, for simplification, the surface tension effects were neglected. In this paper, the evaluation accuracy of gas core lengths is improved by introducing the surface tension effects into the prototype GE prediction method. First, the mechanical balance between gravitational, centrifugal, and surface tension forces is considered. Then, the shape of a gas core tip is approximated by a quadratic function. Finally, using the approximated gas core shape, the authors determine the gas core length satisfying the mechanical balance. This improved GE prediction method is validated by analyzing the gas core lengths observed in simple experiments. Results show that the analytical gas core lengths calculated by the improved GE prediction method become shorter in comparison to the prototype GE prediction method, and are in good agreement with the experimental data. In addition, the experimental data under different temperature and surfactant concentration conditions are reproduced by the improved GE prediction method.
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