408 research outputs found

    Reversible Anionic Redox Activities in Conventional LiNi1/3 Co1/3 Mn1/3 O2 Cathodes.

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    Redox reactions of oxygen have been considered critical in controlling the electrochemical properties of lithium-excessive layered-oxide electrodes. However, conventional electrode materials without overlithiation remain the most practical. Typically, cationic redox reactions are believed to dominate the electrochemical processes in conventional electrodes. Herein, we show unambiguous evidence of reversible anionic redox reactions in LiNi1/3 Co1/3 Mn1/3 O2 . The typical involvement of oxygen through hybridization with transition metals is discussed, as well as the intrinsic oxygen redox process at high potentials, which is 75 % reversible during initial cycling and 63 % retained after 10 cycles. Our results clarify the reaction mechanism at high potentials in conventional layered electrodes involving both cationic and anionic reactions and indicate the potential of utilizing reversible oxygen redox reactions in conventional layered oxides for high-capacity lithium-ion batteries

    Circuit Structure and Control Method to Reduce Size and Harmonic Distortion of Interleaved Dual Buck Inverter

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    A new circuit structure and control method for a high power interleaved dual-buck inverter are proposed. The proposed inverter consists of six switches, four diodes and two inductors, uses a dual-buck structure to eliminate zero-cross distortion, and operates in an interleaved mode to reduce the current stress of switch. To reduce the total harmonic distortion at low output power, the inverter is controlled using discontinuous-current-mode control combined with continuous-current-mode control. The experimental inverter had a power-conversion efficiency of 98.5% at output power = 1300 W and 98.3% at output power = 2 kW, when the inverter was operated at an input voltage of 400 V-DC, output voltage of 220 V-AC/60 Hz, and switching frequency of 20 kHz. The total harmonic distortion was < 0.66%, which demonstrates that the inverter is suitable for high-power dc-ac power conversion.11Ysciescopu

    Ku-band High Efficiency Antenna with Corporate-Series-Fed Microstrip Array

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    Excellent efficiency of a linearly polarized microstrip array in Ku-band is achieved by having proper impedance matching throughout the array and by properly using the corporate and series fed by microstrip transmission lines. The cavity-backed microstrip patch is used to obtain relatively wide bandwidth. The auto-tracking Ku-band antenna in the azimuth direction has developed with a very low profile for vehicle\u27s rooftop mounting, as well as, a low manufacturing cost. The main beam of array is tilted 15° away from the broadside direction to provide optimum coverage for Korea satellite III

    Triple Band Internal Antenna Using Matching Circuits

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    In this paper, a triple-band internal antenna for mobile handsets is present. Dual band operation is generated by using a band reject filter as a matching circuit and without any transformations on its radiator. Moreover, the antenna gives a wide impedance bandwidth in high band by using an additional chip capacitor so that the antenna can operate in triple-band with only one radiator. Details of the proposed antenna are presented

    Unusual Cause of Acute Right Ventricular Dysfunction: Rapid Progression of Superior Vena Cava Aneurysm Complicated by Thrombosis and Pulmonary Thromboembolism

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    Aneurysms of the major thoracic veins are rare. They are usually asymptomatic and thus treated conservatively. We report an extremely rare case of rapidly progressing superior vena cava (SVC) aneurysm complicated by thrombosis and acute pulmonary thromboembolism (PTE) with right ventricular dysfunction. Thrombolytic therapy for hemodynamically significant acute PTE was harmful to the patient in the present case, because it induced further thrombosis and mobilization of the thrombi within the aneurysm, subsequently causing de novo PTE. Surgical aneurysmectomy combined with pulmonary artery embolectomy would be a treatment of choice in patients with SVC aneurysm complicated by acute PTE

    Primary Malignant Pericardial Mesothelioma Presenting as Acute Pericarditis

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    We report on a 21-year-old man with fever, dyspnea, and pleuritic chest pain. An electrocardiography showed ST elevation in multiple lead and thoracic echocardiography revealed moderate pericardial effusion. He was initially diagnosed with acute pericarditis, and treated with nonsteroidal anti-inflammatory drugs and colchicines with clinical and laboratory improvement. After 1 month of medication, his symptoms recurred. An echocardiography showed constrictive physiology and the patient was treated with steroid on the top of current medication. The patient had been well for 7 months until dyspnea and edema developed, when an echocardiography showed marked increased pericardial thickness and constriction. Pericardial biopsy was performed and primary malignant pericardial mesothelioma was diagnosed. Malignancy should be considered in the differential diagnosis of recurrent pericarditis

    Unilateral Hydronephrosis and Hydroureter by Foreign Body in Urinary Bladder: A Case Report

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    Foreign bodies inserted through the urethra are often found in the urinary bladder. We presently report the first case of hydronephrosis and hydroureter due to direct compression in the urinary bladder by silicon, which had been introduced by the patient himself 2 yr prior to presentation with severe right flank pain. Computed tomography indicated a convoluted, high-attenuation mass in the urinary bladder; unilateral hydronephrosis and hydroureter were also present due to direct compression by the mass. The foreign body was removed using a cystoscope. This foreign body was proven to be silicon

    Cutting-edge knowledge on the roles of phytobiotics and their proposed modes of action in swine

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    With the ban on antibiotics in the swine industry, the exploration of alternative options has highlighted phytobiotics as a promising substitute for antibiotic growth promoters, aiming to foster a more sustainable swine industry. Phytobiotics are non-nutritive natural bioactive components derived from plants that offer numerous health benefits. They exhibit antioxidative, antimicrobial, and anti-inflammatory effects. Phytobiotics can be utilized in various forms, including solid, dried, ground, or as extracts, either in crude or concentrated form. They are characterized by low residual levels, a lack of resistance development, and minimal adverse effects. These qualities make phytobiotics an attractive choice for enhancing health and productivity in swine, presenting them as a viable alternative to antibiotics. While there is a general understanding of the effects of phytobiotics, there is still a need for detailed information regarding their effectiveness and mechanisms of action in practical settings. Therefore, the purpose of this mini review was to summarize the current knowledge supporting the roles of phytobiotics and their proposed modes of action, with a specific focus on swine
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