1,092 research outputs found

    Shil'nikov Chaos control using Homoclinic orbits and the Newhouse region

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    A method of controlling Shil'nikov's type chaos using windows that appear in the 1 dimensional bifurcation diagram when perturbations are applied, and using existence of stable homoclinic orbits near the unstable one is presented and applied to the electronic Chua's circuit. A demonstration of the chaos control in the electronic circuit experiments and their simulations and bifurcation analyses are given.Comment: 23 pages, 48 figure

    Costs in English and Japanese legal procedure

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    The authors suggest that Japan is a non-litigious society because of high litigation costs and lengthy procedures and explain the system of costs and changes that have been made and consider what still needs to be done. Article by Sato Niiya and Sam Jarman (British Japanese Law Association) published in Amicus Curiae - Journal of the Institute of Advanced Legal Studies and its Society for Advanced Legal Studies. The Journal is produced by the Society for Advanced Legal Studies at the Institute of Advanced Legal Studies, University of London

    Stability of transverse dunes against perturbations; a theoretical study using dune skeleton model

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    The dune skeleton model is a reduced model to describe the formation process and dynamics of characteristic types of dunes emerging under unidirectional steady wind. Using this model, we study the dependency of the morphodynamics of transverse dunes on the initial random perturbations and the lateral field size. It was found that i) an increase of the lateral field size destabilizes the transverse dune to cause deformation of a barchan, ii) the initial random perturbations decay with time by the power function until a certain time; thereafter, the dune shapes change into three phases according to the amount of sand and sand diffusion coefficient, iii) the duration time, until the transverse dune is broken, increases exponentially with increasing the amount of sand and sand diffusion coefficient. Moreover, under the condition without the sand supply from windward ground, the destabilization of transverse dune in this model qualitatively corresponds to the subaqueous dunes in water tank experiments.Comment: 7pages, 8figure

    LOX/hydrocarbon rocket engine analytical design methodology development and validation. Volume 2: Appendices

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    This final report includes a discussion of the work accomplished during the period from Dec. 1988 through Nov. 1991. The objective of the program was to assemble existing performance and combustion stability models into a usable design methodology capable of designing and analyzing high-performance and stable LOX/hydrocarbon booster engines. The methodology was then used to design a validation engine. The capabilities and validity of the methodology were demonstrated using this engine in an extensive hot fire test program. The engine used LOX/RP-1 propellants and was tested over a range of mixture ratios, chamber pressures, and acoustic damping device configurations. This volume contains time domain and frequency domain stability plots which indicate the pressure perturbation amplitudes and frequencies from approximately 30 tests of a 50K thrust rocket engine using LOX/RP-1 propellants over a range of chamber pressures from 240 to 1750 psia with mixture ratios of from 1.2 to 7.5. The data is from test configurations which used both bitune and monotune acoustic cavities and from tests with no acoustic cavities. The engine had a length of 14 inches and a contraction ratio of 2.0 using a 7.68 inch diameter injector. The data was taken from both stable and unstable tests. All combustion instabilities were spontaneous in the first tangential mode. Although stability bombs were used and generated overpressures of approximately 20 percent, no tests were driven unstable by the bombs. The stability instrumentation included six high-frequency Kistler transducers in the combustion chamber, a high-frequency Kistler transducer in each propellant manifold, and tri-axial accelerometers. Performance data is presented, both characteristic velocity efficiencies and energy release efficiencies, for those tests of sufficient duration to record steady state values

    Carbon Deposition Model for Oxygen-Hydrocarbon Combustion, Volume 2

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    Presented are details of the design, fabrication, and testing of subscale hardware used in the evaluation of carbon deposition characteristics of liquid oxygen and three hydrocarbon fuels for both main chamber and preburner/gas generator operating conditions. In main chamber conditions, the deposition of carbon on the combustion chamber wall was investigated at mixture ratios of 2.0 to 4.0 and at chamber pressures of 1000 to 1500 psia. No carbon deposition on chamber walls was detected at these main chamber mixture ratios. In preburner/gas generator operating conditions, the deposition of carbon on the turbine simulator tubes was evaluated at mixture ratios of 0.20 to 0.60 and at chamber pressures of 720 to 1650 psia. The results of the tests showed carbon deposition rate to be a strong function of mixture ratio and a weak function of chamber pressure. Further analyses evaluated the operational concequences of carbon deposition on preburner/gas generator performance. This is Volume 2 of the report, which contains data plots of all the test programs

    Camptothecin induces urokinase-type plasminogen activator gene-expression in human RC-K8 malignant lymphoma and H69 small cell lung cancer cells.

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    We previously reported that anthracyclines, which could generate reactive oxygen species (ROS), could induce the urokinase-type plasminogen activator (uPA) gene expression in human RC-K8 malignant lymphoma cells and in H69 small cell lung cancer (SCLC) cells. In screening other uPA-inducible anti-cancer agents, we found that camptothecin (CPT) and its derivative, SN38, could induce uPA in RC-K8 and H69 cells. CPT and SN38, which are also used for the treatment of lymphoma and SCLC, significantly increased the uPA accumulation in the conditioned media of both cells in a dose-dependent manner. The maximum induction of uPA mRNA levels was observed 24 h after stimulation. Pretreatment with pyrrolidine dithiocarbamate (PDTC), an anti-oxidant, inhibited the CPT-induced uPA mRNA expression. Thus, CPT induces uPA through gene expression, and, therefore, CPT may influence the tumor-cell biology by up-regulating the uPA/plasmin system.</p

    A Case of Renal Transcatheter Arterial Embolization with Ethanol in Autosomal Dominant Polycystic Kidney Disease for Volume Reduction

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    We report herein the case of a 76-year-old woman with autosomal dominant polycystic kidney disease (ADPKD) and chronic renal failure resulting in intractable abdominal distension and anorexia. Computed tomography (CT) showed enlarged and cystic kidneys. We performed transcatheter arterial embolization (TAE) for renal arteries with ethanol. Absolute ethanol with iodinated contrast medium or Lipiodol was delivered into both renal arteries. The patient's low-grade fever subsided in 5 days, and no other complication occurred. The sensation of abdominal distension diminished approximately 1 month after embolization. A progressive decrease in kidney size was observed soon after embolization. The percentage of the decrement of kidney size was approximately 50% after 17 months. These results indicate that renal TAE with ethanol is a safe, cost-effective, and minimally invasive technique to reduce kidney size in symptomatic ADPKD patients
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