Current oscillation of Silicon Carbide (SiC) based Junction Field-Effect Transistor (JFET) Bi-Directional Switches (BDSs) during turn-on transient has an impact on the stability and reliability of ...power electronic conversion systems. Proper handling of the current oscillation during turn-on transient is suitable to exploit the full potential of fast SiC JFET BDSs. In this paper one method is proposed to damp the current oscillation, namely, paralleling a snubber capacitor (C J ) with JFET in power loop. Equivalent and simplified circuit models considering all parasitic elements for SiC JFET BDSs for the turn-on condition are presented. Simple analytic expression is introduced to provide the theoretical analysis of the switching oscillation phenomenon, and to guide the optimal value of snubber capacitor. Experimental results validate the effectiveness of the proposed method.
Surveillance of antibiotic resistance and nosocomial infections is one of the most important functions of a hospital infection control program. We employed the association rule method for ...automatically identifying new, unexpected, and potentially interesting patterns in hospital infection control. We hypothesized that mining for low-support, low-confidence rules would detect unexpected outbreaks caused by a small number of cases. To build a framework, we preprocessed the data and added new templates to eliminate uninteresting patterns. We applied our method to the culture data collected over 3 months from 10 hospitals in the UPMC Health System. We found that the new process and system are efficient and effective in identifying new, unexpected, and potentially interesting patterns in surveillance data. The clinical relevance and utility of this process await the results of prospective studies.
Chemical substitution during growth is a well-established method to manipulate electronic states of quantum materials, and leads to rich spectra of phase diagrams in cuprate and iron-based ...superconductors. Here we report a novel and generic strategy to achieve nonvolatile electron doping in series of（i.e.11 and 122 structures） Fe-based superconductors by ionic liquid gating induced protonation at room temperature. Accumulation of protons in bulk compounds induces superconductivity in the parent compounds, and enhances the Tclargely in some superconducting ones. Furthermore, the existence of proton in the lattice enables the first proton nuclear magnetic resonance（NMR） study to probe directly superconductivity. Using Fe S as a model system, our NMR study reveals an emergent high-Tcphase with no coherence peak which is hard to measure by NMR with other isotopes. This novel electric-fieldinduced proton evolution opens up an avenue for manipulation of competing electronic states（e.g.Mott insulators）, and may provide an innovative way for a broad perspective of NMR measurements with greatly enhanced detecting resolution.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Laboratory test orders constitute an early outbreak data source. CDC receives laboratory order data in HL7 format from the Laboratory Corporation of America (LabCorp) and plans to use the data in the ...BioSense Early Event Detection and Situation Awareness System. These LabCorp data contain information on tests ordered and include the type of test ordered and the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM)-coded reasons for the order. A consensus panel was formed to group test orders on the basis of expert opinion into eight standard syndrome categories to provide an additional data source for early outbreak detection. A laboratory order taxonomy was developed and used in the mapping consolidation phase. The five main classes of this taxonomy are miscellaneous functional tests, fluid screening tests, system-specific tests, tests for specific infections (by primary manifestation), and tests for specific noninfectious diseases. Summary of numbers of laboratory order codes in each syndrome category are fever (53), respiratory (53), gastrointestinal (27), neurological (35), rash (37), lymphadenitis (20), localized cutaneous lesion (11), and specific infection (63). With the daily use of laboratory order data in BioSense, the actual distribution of laboratory order codes in syndrome groups can be evaluated, allowing modification of the mapping.
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BFBNIB, DOBA, IZUM, KILJ, NMLJ, NUK, ODKLJ, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Laboratory test orders constitute an early outbreak data source. CDC receives laboratory order data in HL7 format from the Laboratory Corporation of America (LabCorp) and plans to use the data in the ...BioSense Early Event Detection and Situation Awareness System.
These LabCorp data contain information on tests ordered and include the type of test ordered and the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM)-coded reasons for the order. A consensus panel was formed to group test orders on the basis of expert opinion into eight standard syndrome categories to provide an additional data source for early outbreak detection. A laboratory order taxonomy was developed and used in the mapping consolidation phase. The five main classes of this taxonomy are miscellaneous functional tests, fluid screening tests, system-specific tests, tests for specific infections (by primary manifestation), and tests for specific noninfectious diseases.
Summary of numbers of laboratory order codes in each syndrome category are fever (53), respiratory (53), gastrointestinal (27), neurological (35), rash (37), lymphadenitis (20), localized cutaneous lesion (11), and specific infection (63).
With the daily use of laboratory order data in BioSense, the actual distribution of laboratory order codes in syndrome groups can be evaluated, allowing modification of the mapping.
•A new kind of data-based fault detection method is proposed, which combines adaptive dynamic programming and multiple-modeling.•A stable working state is established by using ADP and history data. ...Once the system runs out of the stable state, it’s known for sure that fault occurs.•A whole stable working space of the system can be built with the method of multi-modeling and data of all working modes, as long as system states remain in the working space, system is working normally, exclude the disturbance of modes switching, and improve the accuracy of the fault detection algorithm.•The fault can be isolated, if the direction and magnitude of the deviate vector are solved, which can be achieved by approximation and iteration using the method of ADP.
This paper presents a adaptive dynamic programming-based fault detection and isolation (FDI) scheme to detect and isolate faults in an aircraft jet engine. To this end, the weights in Actor-Critic neural networks are first tuned to learn the input-output map of the jet engine considering its multiple working modes. The convergences of the trainings in Critic-Actor neural networks are strictly proved without knowing the drift dynamics and the input dynamics in the presence of unknown nonlinearities and approximation errors. Using the residuals that are generated by measuring the difference of each network output and the measured engine output, various criteria are established for accomplishing the fault diagnosis task, that addresses the problem of fault detection and isolation of the system components. A number of simulation studies are carried out for combustion chamber of a single-spool jet engine to demonstrate and illustrate the advantages, capabilities, and performance of our proposed fault diagnosis scheme.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Hydrogen production through water splitting has been considered as a green, pure and high-efficient technique. As an important half-reaction involved, hydrogen evolution reaction is a complex ...electrochemical process involving liquid-solid-gas three-phase interface behaviour. Therefore, new concepts and strategies of material design are needed to smooth each pivotal step. Here we report a multiscale structural and electronic control of molybdenum disulfide foam to synergistically promote the hydrogen evolution process. The optimized three-dimensional molybdenum disulfide foam with uniform mesopores, vertically aligned two-dimensional layers and cobalt atoms doping demonstrated a high hydrogen evolution activity and stability. In addition, density functional theory calculations indicate that molybdenum disulfide with moderate cobalt doping content possesses the optimal activity. This study demonstrates the validity of multiscale control in molybdenum disulfide via overall consideration of the mass transport, and the accessibility, quantity and capability of active sites towards electrocatalytic hydrogen evolution, which may also be extended to other energy-related processes.
RuO2 is considered as the state‐of‐the‐art electrocatalyst for the oxygen evolution reaction (OER) in acidic media. However, its practical application is largely hindered by both the high reaction ...overpotential and severe electrochemical corrosion of the active centers. To overcome these limitations, innovative design strategies are necessary, which remains a great challenge. Herein, robust interface Ru centers between RuO2 and graphene, via a controllable oxidation of graphene encapsulating Ru nanoparticles, are presented to efficiently enhance both the activity and stability of the acidic OER. Through precisely controlling the reaction interface, a much lower OER overpotential of only 227 mV at 10 mA cm−2 in acidic electrolyte, compared with that of 290 mV for commercial RuO2, but a significantly higher durability than the commercial RuO2, are achieved. Density functional theory (DFT) calculations reveal that the interface Ru centers between the RuO2 and the graphene can break the classic scaling relationships between the free energies of HOO* and HO* to reduce the limiting potential, rendering an enhancement in the intrinsic OER activity and the resistance to over‐oxidation and corrosion for RuO2.
The robust interface Ru centers between RuO2 and graphene are found to boost both activity and stability for the acidic oxygen evolution reaction (OER), exhibiting a much lower OER overpotential of only 227 mV at 10 mA cm−2 compared with that of 290 mV for commercial RuO2 but a significantly higher durability than the commercial RuO2.
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•Microwave heating has specific effect in accelerating the degradation rates.•SMX degradation was enhanced by higher temperature, persulfate dose and initial pH.•Buffer phosphates inhibited SMX ...degradation and TOC removal in the MW/PS system.•Byproducts were identified to propose the possible pathways of SMX degradation.•Toxicity of SMX solutions increased firstly and then decreased to very low level.
Thermal activation of persulfate was confirmed to be effective in the destruction of organic pollutants. Microwave heating has different inherent mechanism from that of conventional heating, and the application of microwave heating to chemical reactions has attracted great interest. The objective of this study was to evaluate the degradation of sulfamethoxazole (SMX) in a microwave-activated persulfate (MW/PS) system. The results indicated that MW/PS degradation of SMX followed pseudo-first-order kinetics, and compared with conventional heating, microwave heating has a special effect on SMX degradation with higher reaction rate and shorter process time. The process of SMX degradation was accelerated by higher reaction temperature, persulfate dose or pH in the MW/PS system, while higher initial SMX concentration and the presence of phosphates slowed down the degradation rates. High level of chloride showed some inhibition on the SMX degradation, while low chloride level and carbonate enhanced the SMX degradation. 3-Amino-5-methylisoxazole, sulfanilic acid, hydroxyl-SMX and nitroso-SMX derivatives were identified as the major degradation intermediate products by HPLC/MS. The possible reaction pathways including hydroxylation of the benzene ring, oxidation of the amine group at the benzene ring and the S–N cleavage were proposed. The acute toxicity tests with Photobacterium phosphoreum, Vibrio fischeri and Vibrio qinghaiensis indicated that the inhibitory effect of the 10-time diluted unheated SMX mixture solution being 22.6–48.0%, increased to >99.9% after 4min and decreased to <−10% after 60minMW/PS treatment that could be attributed to the rapid formation and subsequent disappearance of oxidation products.
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