228 research outputs found

    Generalized hypergeometric functions with several variables

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    We introduce a hypergoemetirc series with two complex variables, which generalizes Appell's, Lauricella's and Kemp\'e de F\'eriet's hypergeometric series, and study the system of differential equations that it satisfies. We determine the singularities, the rank and the condition for the reducibility of the system. We give complete local solutions of the system at many singular points of the system and solve the connection problem among these local solutions. Under some assumptions, the system is written as a KZ equation. We determine its spectral type in the direction of coordinates as well as simultaneous eigenspace decompositions of residue matrices. The system may or may not be rigid in the sense of N.~Katz viewed as an ordinary differential equation in some direction. We also show that the system is a special case of Gel'fand-Kapranov-Zelevinsky system. From this point of view, we discuss multivariate generalizations.Comment: 68 pages, any comment is welcom

    Performance of a carbon monoxide sensor based on zirconia-doped ceria

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    AbstractResistive-type carbon monoxide sensors were fabricated using zirconia-doped ceria, and their sensing properties were evaluated and compared with equivalent devices based on non-doped ceria. The response of both sensor types was found to increase with decreasing temperature, while the response at 450°C of a sensor fired at 950°C was greater than that of a sensor fired at 1100°C. When fired at 950°C, however, the response at 450°C of a sensor created using zirconia-doped ceria was slightly less than that of a sensor constructed from non-doped ceria. Multivariate analysis confirmed that the response of both sensor types is proportional to the resistance raised to the power of about 0.5, and inversely proportional to the particle size raised to a power of about 0.8. The sensor response time can be considered almost the same regardless of whether zirconia doping is used or not

    Thoracoscopic Localization of Small Peripheral Pulmonary Lesions Using Percutaneous Computed Tomography-guided Pleural Dye Marking: A Retrospective Analysis

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    Small pulmonary lesions are often difficult to localize during thoracoscopic surgery. We describe a new com-puted tomography (CT)-guided pleural dye-marking method for small peripheral pulmonary lesions that does not involve a visceral pleural puncture. We used this technique for 23 lesions (22 patients) who underwent tho-racoscopic partial lung resection (Nov. 2016-Jan. 2018). With the patient in the lateral decubitus position, pre-operative CT-guided marking on the skin over the lesion was performed. During the surgery, we marked the visceral pleura with a skin marker directly or with an infant-size nutrition catheter with crystal violet at the tip through a venous indwelling needle inserted perpendicular to the skin marking. We localized and resected the lesions in all cases, without complications. The median nodule size measured histopathologically was 8 (4-20) mm overall, and 7 (0-20) mm of the solid part; the median distance from the visceral pleura to the nodule was 9 (1-33) mm. The median operation time was 67 (37-180) min. The median postoperative hospital stay was 3 (3-11) days. Our CT-guided pleural dye-marking method is useful and safe for the localization of small periph-eral pulmonary lesions in thoracoscopic partial lung resections

    Resistive Oxygen Sensor Using Ceria-Zirconia Sensor Material and Ceria-Yttria Temperature Compensating Material for Lean-Burn Engine

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    Temperature compensating materials were investigated for a resistive oxygen sensor using Ce0.9Zr0.1O2 as a sensor material for lean-burn engines. The temperature dependence of a temperature compensating material should be the same as the sensor material; therefore, the Y concentration in CeO2-Y2O3 was optimized. The resistance of Ce0.5Y0.5O2-δ was independent of the air-to-fuel ratio (oxygen partial pressure), so that it was confirmed to function as a temperature compensating material. Sensor elements comprised of Ce0.9Zr0.1O2 and Ce0.5Y0.5O2-δ were fabricated and the output was determined to be approximately independent of the temperature in the wide range from 773 to 1,073 K

    Wernicke's Encephalopathy in a Patient with Peptic Ulcer Disease

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    We report a 74-year-old man with Wernicke's encephalopathy (WE) whose only prior illness was peptic ulcer disease. Upper gastrointestinal endoscopy demonstrated gastric ulcer scars accompanied by marked deformity, without pathologic evidence of malignancy. WE due to peptic ulcer disease in previous reports was substantially associated with thiamine deficiency due to recurrent vomiting or surgical procedures. In our case, however, there was no history of vomiting or gastrointestinal surgery. Besides, we thoroughly ruled out other known clinical settings related to WE. There is the possibility that peptic ulcer disease itself provoked thiamine deficiency due to malabsorption

    Effects of High-Humidity Aging on Platinum, Palladium, and Gold Loaded Tin Oxide—Volatile Organic Compound Sensors

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    This study is an investigation of high-humidity aging effects on the total volatile organic compound (T–VOC) gas-sensing properties of platinum, palladium, and gold-loaded tin oxide (Pt,Pd,Au/SnO2) thick films. The sensor responses of the high-humidity aged Pt,Pd,Au/SnO2, a non-aged Pt,Pd,Au/SnO2, and a high-humidity aged Pt/SnO2 to T–VOC test gas have been measured. The high-humidity aging is an effective treatment for resistance to humidity change for the Pt,Pd,Au/SnO2 but not effective for the Pt/SnO2. The mechanism of the high-humidity aging effects is discussed based on the change of surface state of the SnO2 particles

    Disconnectivity between Dorsal Raphe Nucleus and Posterior Cingulate Cortex in Later Life Depression

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    The dorsal raphe nucleus (DRN) has been repeatedly implicated as having a significant relationship with depression, along with its serotoninergic innervation. However, functional connectivity of the DRN in depression is not well understood. The current study aimed to isolate functional connectivity of the DRN distinct in later life depression (LLD) compared to a healthy age-matched population. Resting state functional magnetic resonance imaging (rsfMRI) data from 95 participants (33 LLD and 62 healthy) were collected to examine functional connectivity from the DRN to the whole brain in voxel-wise fashion. The posterior cingulate cortex (PCC) bilaterally showed significantly smaller connectivity in the LLD group than the control group. The DRN to PCC connectivity did not show any association with the depressive status. The findings implicate that the LLD involves disruption of serotoninergic input to the PCC, which has been suggested to be a part of the reduced default mode network in depression

    Unsteady analysis of non-isothermal natural ventilation airflow using domain decomposition technique with LES

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    Matsubara T., Kobayashi T., Yamanaka T., et al. Unsteady analysis of non-isothermal natural ventilation airflow using domain decomposition technique with LES. Building and Environment 262, 111763 (2024); https://doi.org/10.1016/j.buildenv.2024.111763.A Large Eddy Simulation (LES) can predict an unsteady airflow with high accuracy. However, the application of LES to indoor airflows is difficult because of the large computational burden of the coupled simulation of both the indoor/outdoor domains. To address this issue, a domain decomposition technique (DDT) was proposed so that the outdoor simulation results could be applied as boundary conditions for the indoor air simulation by decoupling the indoor/outdoor domains. However, most previous studies have only investigated the applicability of DDT under steady-state and isothermal conditions. In an actual natural ventilation design, if buoyancy force is expected as the primary natural ventilation driving force, the temperature difference between indoor/outdoor cannot be neglected. This study aimed to validate the DDT under non-isothermal conditions. First, wind tunnel experiments were conducted on an isolated building under non-isothermal conditions to obtain data for the computational fluid dynamics boundary conditions and accuracy verification. The wind pressure coefficient, velocity distribution, and temperature distribution were measured during the experiment. Then, unsteady analysis (i.e., whole domain simulation) was performed using LES to reproduce the wind tunnel experiment. Finally, DDT was applied to the Large Eddy Simulation, and its accuracy was verified by comparing the velocity distribution, temperature, and airflow rate between the whole domain and DDT. As a result, in the present study where the total number of grids in the entire domain was approximately 10 times that in the indoor domain, DDT exhibited good accuracy, and decreased the computational load by over 70 %
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