111 research outputs found

    Microtremor exploration in Tsushima Campus, Okayama University

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     In this report, microtremor array observations were conducted in the Tsushima Campus of Okayama University, and the subsurface velocity structure was estimated from the analysis of the records. The results indicate that a five-layer S-wave velocity structure from the surface to the seismic basement equivalent layer with thicknesses of 8, 24, 80 and 180 m and velocities of 150, 450, 1100, 1700 and 3200 m/s, respectively, is reasonable. This model explains to some extent the observed phase velocity and H/V spectral ratios. It is also consistent with the surface borehole results. Furthermore, the areal characteristics of the H/V spectral ratios were also presented, allowing us to estimate the trend of the ground structure in shallow areas

    Visualization and Measurement of Adsorption/Desorption Process of Ethanol in Activated Carbon Adsorber

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    Proceedings of the 10th World Conference on Neutron Radiography (WCNR-10) Grindelwald, Switzerland October 5–10, 2014Adsorption refrigerator is one of the efficient tools for waste heat recovery, because the system is driven by heat at relative low temperature. However, the coefficient of performance is low due to its batch operation and the heat capacity of the adsorber. In order to improve the performance, it is important to optimize the configuration to minimize the amount of driving heat, and to clarify adsorption/desorption phenomena in transient conditions. Neutron radiography was applied to visualize and measure the adsorption amount distribution in an adsorber. The visualization experiments had been performed at the neutron radiography facility of E-2 port of Kyoto University Research Reactor. Activated carbon and ethanol were used as the adsorbent and refrigerant. From the acquired radiographs, adsorption amount was quantitatively measured by applying the umbra method using a checkered neutron absorber with boron powder. Then, transient adsorption and desorption processes of a rectangular adsorber with 84 mm in width, 50 mm in height and 20 mm in depth were visualized. As the result, the effect of fins in the adsorbent layer on the adsorption amount distribution was clearly visualized

    In-situ Neutron Tomography on Mixing Behavior of Supercritical Water and Room Temperature Water in a Tubular Flow Reactor

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    We have synthesized metal oxide nanoparticles through hydrothermal reaction at around 400 °C and 25 MPa by mixing the stream of metal ion solution at room temperature with another stream of supercritical water in a continuous flow-type reactor. In order to visualize the mixing behavior of the two streams, we performed neutron tomography measurements. By performing tomography measurements while rotating the mixing piece with supplying supercritical water and room temperature water, we succeeded in obtaining the three dimensional distribution of neutron attenuation. The results clearly showed how the two streams mix, which serves as a reference for numerical simulation

    Circulation Characteristics and Density Wave Oscillation in a Natural Circulation Loop of Liquid Nitrogen

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    Circulation characteristics and flow instabilities are investigated in a natural circulation loop of liquid nitrogen. The circulation velocity increases with the increase in the heat flux and decreases with the increase in the flow restriction. Beyond a certain limit of heat flux, so called "density wave oscillation"occurs. By applying a lumped-parameter model and homogeneous two-phase flow model to the present natural circulation system, the numerical simulation is conducted. The simulation well represents the transient behavior of the system and the estimated threshold conditions of the flow oscillation agree well with the experimental results

    Visualization of Bubble and Large Particle Movements in a Fluidized-Bed of Binary Mixture of Particles

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    Fluidized-bed combustion systems are composed of many kinds of particles with avariety of sizes,e.g.coal,sand,RDF,limestone etc.ln such a binary system of particles,the segregation,if occurs,many harm the combustion,mixing and heat transfer in the bed,depending on the particle movement. The particle movement or circulation in the fluidized-bed depends on many factors,such as the density ratio,size ratio,shape of particle,fluidization velocity. Owing to the difficulty of flow visualization,such particle movement has not been fully understood so far. This paper describes large-particle movement obtained by the flow visualization using neutron radiography. Tracer particles mixed into the fluidized particles indicated clearly bubbles and the cloud behavior around the bubble. Image processing,i.e. PIV and PTV,gives rather clear understanding on the interaction between the large particle,emulsion and/or cloud behavior in the bed

    Acute adrenal crisis after orthopedic surgery for pathologic fracture

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    BACKGROUND: Adrenal crisis after surgical procedure is a rare but potentially catastrophic life-threatening event. Its manifestations, such as hypotension, tachycardia, hypoxia, and fever mimic the other more common postoperative complications. Clinical outcome is dependent upon early recognition of the condition and proper management with exogenous steroid administration. CASE PRESENTATION: We report a 75-year-old man who presented with shock immediately after surgery for a femoral fracture from lung cancer metastasis. Anemia and severe hyponatremia were detected. Despite adequate fluid resuscitation, nonspecific symptoms including hypotension, tachycardia, hypoxia, fever and confusion occurred. Emergent CT revealed enlarged bilateral adrenal glands. Under the diagnosis of adrenal crisis due to metastatic infiltration of adrenal glands, the patient was treated with appropriate steroid replacement resulting in rapid improvement and recovery. CONCLUSION: We describe a case of adrenal crisis caused by the lack of adrenal reserve based on metastatic involvement and surgical stress, the first published case of adrenal crisis after surgery for a pathologic fracture from lung cancer metastasis. Surgeons treating pathologic fractures should be aware of this complication and familiar with its appropriate therapy because of increasing opportunity to care patients with metastatic bone tumors due to recent advances in cancer treatment

    Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

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    Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation
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