WorldWideScience

Sample records for intranuclear cascades

  1. Time-dependent intranuclear cascade model

    International Nuclear Information System (INIS)

    Barashenkov, V.S.; Kostenko, B.F.; Zadorogny, A.M.

    1980-01-01

    An intranuclear cascade model with explicit consideration of the time coordinate in the Monte Carlo simulation of the development of a cascade particle shower has been considered. Calculations have been performed using a diffuse nuclear boundary without any step approximation of the density distribution. Changes in the properties of the target nucleus during the cascade development have been taken into account. The results of these calculations have been compared with experiment and with the data which had been obtained by means of a time-independent cascade model. The consideration of time improved agreement between experiment and theory particularly for high-energy shower particles; however, for low-energy cascade particles (with grey and black tracks in photoemulsion) a discrepancy remains at T >= 10 GeV. (orig.)

  2. Influence of non-binary effects on intranuclear cascade method

    International Nuclear Information System (INIS)

    Gomes, E.H.C.

    1985-01-01

    The importance of non binary process effects in the intranuclear cascade method is analysed. It is shown that, in the higher density steps, the non binary collisions lead to baryon density distribution and rapidity differents from the one obtained using the usual intranuclear cascade method (limited to purely binary collisions). The validity of the applications of binary intranuclear cascade method to the simulation of the thermal equilibrium, nuclear transparency and particle production, is discussed. (M.C.K.) [pt

  3. Participant intimacy: A cluster analysis of the intranuclear cascade

    International Nuclear Information System (INIS)

    Cugnon, J.; Knoll, J.; Randrup, J.

    1981-01-01

    The intranuclear cascade for relativistic nuclear collisions is analyzed in terms of clusters consisting of groups of nucleons which are dynamically linked to each other by violent interactions. The formation cross sections for the different cluster types as well as their intrinsic dynamics are studied and compared with the predictions of the linear cascade model ( rows-on-rows ). (orig.)

  4. Causality and relativistic effects in intranuclear cascade calculations

    International Nuclear Information System (INIS)

    Kodama, T.; Duarte, S.B.; Chung, K.C.; Donangelo, R.J.; Nazareth, R.A.M.S.

    1983-01-01

    Relativistic effects in high energy nuclear collisions, when non-invariance of simultaneity is taken into account, are studied. It is shown that the time ordering of nucleon-nucleon collisions is quite different for different observers, giving in some cases non-invariant final results for intranuclear cascade (INC) calculations. In particular, an example of such a case is shown, in which the INC simulation, depending on the reference frame, presents a kind of density instability caused by a specific time ordering of collision events. A new INC calculation, using a causality preserving scheme, which minimizes this kind of relativistic effect is proposed. It is verified that the causality preserving INC prescription essentially recovers the relativistic invariance. (Author) [pt

  5. Relativistic nuclear reactions and the intranuclear cascade method

    International Nuclear Information System (INIS)

    Duarte, S.J.B.

    1983-01-01

    The intranuclear cascade (INC) procedure is analised as a method to describe the processes of relativistic heavy ions collisions. The effects caused by nucleon concentration during the collision are discussed. It is shown explicitly that the occurence of nonbinary collisions among particles is not at all negligible, in spite of the fact that the convencional INC only permits nucleon-nucleon binary collisions. The relativistic invariance of the results obtained by the INC method is discussed. This is especially important when the method is applied for much higher energies. Many of conventional procedures in the method will give certainly different predictions depending on what system of reference is used. The origin of such non-invariance nature of INC calculations is discussed and an alternative way of defining the INC procedure which presents a better credibility with respect to the relativistic invariance property is proposed. (Author) [pt

  6. Monte Carlo event generator MCMHA for high energy hadron-nucleus collisions and intranuclear cascade interactions

    International Nuclear Information System (INIS)

    Iga, Y.; Hamatsu, R.; Yamazaki, S.

    1988-01-01

    The Monte Carlo event generator for high energy hadron-nucleus (h-A) collisions has been developed which is based on the multi-chain model. The concept of formation zone and the cascade interactions of secondary particles are properly taken into account in this Monte Carlo code. Comparing the results of this code with experimental data, the importance of intranuclear cascade interactions becomes very clear. (orig.)

  7. The performance of a new Geant4 Bertini intra-nuclear cascade model in high throughput computing (HTC) cluster architecture

    Energy Technology Data Exchange (ETDEWEB)

    Aatos, Heikkinen; Andi, Hektor; Veikko, Karimaki; Tomas, Linden [Helsinki Univ., Institute of Physics (Finland)

    2003-07-01

    We study the performance of a new Bertini intra-nuclear cascade model implemented in the general detector simulation tool-kit Geant4 with a High Throughput Computing (HTC) cluster architecture. A 60 node Pentium III open-Mosix cluster is used with the Mosix kernel performing automatic process load-balancing across several CPUs. The Mosix cluster consists of several computer classes equipped with Windows NT workstations that automatically boot, daily and become nodes of the Mosix cluster. The models included in our study are a Bertini intra-nuclear cascade model with excitons, consisting of a pre-equilibrium model, a nucleus explosion model, a fission model and an evaporation model. The speed and accuracy obtained for these models is presented. (authors)

  8. Intranuclear cascade+percolation+evaporation model applied to the {sup 12}C+{sup 197}Au system at 1 GeV/nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Volant, C.; Turzo, K.; Trautmann, W.; Auger, G.; Begemann-Blaich, M.-L.; Bittiger, R.; Borderie, B.; Botvina, A.S.; Bougault, R.; Bouriquet, B.; Charvet, J.-L.; Chbihi, A.; Dayras, R.; Dore, D.; Durand, D.; Frankland, J.D.; Galichet, E.; Gourio, D.; Guinet, D.; Hudan, S.; Imme, G.; Lautesse, Ph.; Lavaud, F.; Le Fevre, A.; Lopez, O.; Lukasik, J.; Lynen, U.; Mueller, W.F.J.; Nalpas, L.; Orth, H.; Plagnol, E.; Raciti, G.; Rosato, E.; Saija, A.; Schwarz, C.; Seidel, W.; Sfienti, C.; Steckmeyer, J.C.; Tamain, B.; Trzcinski, A.; Vient, E.; Vigilante, M.; Zwieglinski, B

    2004-04-05

    The nucleus-nucleus Liege intranuclear-cascade+percolation+evaporation model has been applied to the {sup 12}C+{sup 197}Au data measured by the INDRA-ALADIN collaboration at GSI. After the intranuclear cascade stage, the data are better reproduced when using the Statistical Multiframentation Model as afterburner. Further checks of the model are done on data from the EOS and KAOS collaborations.

  9. Statistical simulation of hadron-nucleus and light nucleus-nucleus interaction. Intranuclear cascade model

    International Nuclear Information System (INIS)

    Lobov, G.A.; Stepanov, N.V.; Sibirtsev, A.A.; Trebukhovskij, Yu.V.

    1983-01-01

    A new version of the program of statistical simulation of hadron-nucleus and light nucleus-nucleus interaction is elaborated. The cascade part of the program is described. The comparison of model predictions with the proton-nucleus interaction experiments is performed. A satisfactory calculations-experiment agreement is obtained

  10. Participant intimacy A cluster analysis of the intranuclear cascadet

    Science.gov (United States)

    Cugnon, J.; Knoll, J.; Randrup, J.

    1981-05-01

    The intranuclear cascade for relativistic nuclear collisions is analyzed in terms of "clusters" consisting of groups of nucleons which are dynamically linked to each other by violent interactions. The formation cross sections for the different cluster types as well as their intrinsic dynamics are studied and compared with the predictions of the linear cascade model ("rows-on-rows").

  11. Intranuclear cascade evaporation model predictions of double differential A(p,xn) neutron cross sections and comparison with experiments at 318 MeV and 800 MeV proton energy

    International Nuclear Information System (INIS)

    Cloth, P.; Dragovitsch, P.; Filges, D.; Reul, C.

    1989-08-01

    The intranuclear-cascade evaporation model as implemented in the high energy radiation transport code HETC, subsystem of HERMES is used in the calculation of double differential cross sections of proton induced neutron production. The investigations were done on target elements C, Al, Ta, Ni, W, Pb, and U at 318 MeV incident proton energy and on C, Al, Pb, and U at 800 MeV, respectively. The predictions of the INCE model were compared with experimental data for double differential cross sections taken at 7.5 and 30 degrees scattering angles at the Los Alamos WNR facility utilizing the Time of Flight technique at LANL. The calculations performed here are part of a experimental-theoretical program within the LANL-KFA collaboration concerning medium energy cross section measurements mainly neutrons and state of the art computer code validations of these measurements. In general, the model predictions reproduce the correct neutron production for evaporation neutrons and are also in good agreement with the experimental data at high neutron energies. In the energy range dominated by preequilibrium processes an underestimation of experimental yields has to be remarked. (orig.)

  12. Improvement of the spallation-reaction simulation code by considering both the high-momentum intranuclear nucleons and the preequilibrium process

    International Nuclear Information System (INIS)

    Ishibashi, K.; Miura, Y.; Sakae, T.

    1990-01-01

    In the present study, intranuclear nucleons with a high momentum are introduced into intranuclear cascade calculation, and the preequilibrium effects are considered at the end of the cascade process. The improvements made in the HETC (High Energy Transport Code) are outlined, focusing on intranuclear nucleons with a high momentum, and termination of the intranuclear cascade process. Discussion is made of the cutoff energy, and Monte Carlo calculations based on an excitation model are presented and analyzed. The experimental high energy neutrons in the backward direction are successfully reproduced. The preequilibrium effect is considered in a local manner, and this is introduced as a simple probability density function for terminating the intranuclear cascade process. The resultant neutron spectra reproduce the shoulders of the experimental data in the region of 20 to 50 MeV. The exciton model is coded with a Monte Carlo algorithm. The results of the exciton model calculation is not so appreciable except for intermediate energy neutrons in the backward direction. (N.K.)

  13. Ultrastructural cytochemical analysis of intranuclear arsenic inclusions

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, E.M.B.

    1987-01-01

    To establish the chemical composition of the arsenic inclusion, freshly isolated preparations of inclusions and epon-embedded thin sections of inclusions were subjected to ultrastructural cytochemical analysis. Intranuclear inclusions are composed of amorphous, arsenic-containing subunits aligned linearly to form a coiled complex. Lipase, ribonuclease, deoxyribonuclease, trypsin, pepsin, protease, amylase, or ethylenediaminetetraacetic acid (EDTA) was used to digest or chelate these inclusions. Following enzymatic digestion or chelation, the electron opacity of inclusions was compared with that of control sections exposed for equal times to equivalent solutions lacking the enzymes. Exposure to amylase caused a consistent reduction in the electron opacity of thin sections of inclusions and almost complete digestion of the freshly isolated preparations of inclusions. This was indicative of the presence of a carbohydrate moiety within arsenic inclusions. Incubation of inclusions with EDTA resulted in solubilization of freshly isolated and thin-sectioned embedded material. These data indicated that the intranuclear arsenic inclusion is composed of both metallic and carbohydrate moieties, confirming earlier studies which identified arsenic within inclusions using instrumental neutron activation analysis and x-ray microprobe analysis.

  14. Identification of intranuclear inclusions is useful for the cytological diagnosis of ovarian clear cell carcinoma.

    Science.gov (United States)

    Naka, Masaki; Ohishi, Yoshihiro; Kaku, Tsunehisa; Watanabe, Sumiko; Tamiya, Sadafumi; Ookubo, Fumihiko; Kato, Kiyoko; Oda, Yoshinao; Sugishima, Setsuo

    2015-11-01

    The aim of this study was to clarify the diagnostic significance of the presence of intranuclear inclusions in clear cell carcinoma (CCC). We analyzed 98 imprint specimens and 53 ascites specimens from 98 ovarian carcinoma cases [28 CCCs, 37 serous carcinomas (SCs), 22 endometrioid carcinomas (ECs), and 11 mucinous carcinomas (MCs)]. We examined (1) frequency of intranuclear inclusion-positive cases of each ovarian carcinoma subtype, using imprint specimens, (2) frequency of intranuclear inclusion-positive cells of each ovarian carcinoma subtype, using imprint specimens, (3) frequency of intranuclear inclusion-positive cases of each ovarian carcinoma subtype, using ascites specimens, and (4) sensitivity and specificity of the presence of intranuclear inclusions for the cytological diagnosis of CCC. (1) The frequency of intranuclear inclusion-positive cases in CCC (96.4%) was significantly higher than in SC (13.5%), EC (13.6%), and MC (18.2%) (P < 0.001). Two or more intranuclear inclusions in a single nucleus were observed only in CCC. (2) The frequency of intranuclear inclusion-positive cells in CCC (median, 0.41%) was significantly higher than in non-CCC subtypes (0.010%) (P < 0.001). (3) Using ascites specimens, the frequency of intranuclear inclusion-positive cases in CCC (78.6%) was significantly higher than in SC (10.3%), EC (0%), and MC (0%) (P < 0.001). (4) The sensitivity of intranuclear inclusions was 96.4%, and the specificity was 85.7%. The identification of intranuclear inclusions, in particular a high frequency and multiple intranuclear inclusions in a single nucleus, is useful for the cytological diagnosis of CCC. Furthermore, these results may be applicable to ascites cytology. © 2015 Wiley Periodicals, Inc.

  15. Intranuclear coccidiosis caused by Cyclospora spp. in calves.

    Science.gov (United States)

    Yamada, Minako; Hatama, Shinichi; Ishikawa, Yoshiharu; Kadota, Koichi

    2014-09-01

    Intranuclear coccidiosis in 3 calves is described. Two calves with no genetic relationship were kept in the same pen, and the third calf was on another farm. The animals suffered from watery diarrhea or severe emaciation. Histologic examination showed epithelial desquamation (cases 1 and 2) or atrophy (case 3) of the jejunal villi. Coccidial meronts or merozoites were present in the nuclei of the majority of villus epithelial cells. There were rare intranuclear macrogametocytes, macrogametes, microgametocytes, microgametes, and oocysts in cases 1 and 2, but these were more easily observed in case 3. Parasite 18S ribosomal RNA sequences from case 1 showed 99.5% sequence identity with Cyclospora sp. Guangzhou 1, which has been found in fecal samples of cattle from China. In addition to the molecular results in one of the cases, the fact that the microgametocytes and oocysts were noticeably smaller in size than those of Eimeria alabamensis in all cases indicates the close association between Cyclospora and the 3 cases described herein. © 2014 The Author(s).

  16. Comparative Genomic Analysis of Holospora spp., Intranuclear Symbionts of Paramecia

    Directory of Open Access Journals (Sweden)

    Sofya K. Garushyants

    2018-04-01

    Full Text Available While most endosymbiotic bacteria are transmitted only vertically, Holospora spp., an alphaproteobacterium from the Rickettsiales order, can desert its host and invade a new one. All bacteria from the genus Holospora are intranuclear symbionts of ciliates Paramecium spp. with strict species and nuclear specificity. Comparative metabolic reconstruction based on the newly sequenced genome of Holospora curviuscula, a macronuclear symbiont of Paramecium bursaria, and known genomes of other Holospora species shows that even though all Holospora spp. can persist outside the host, they cannot synthesize most of the essential small molecules, such as amino acids, and lack some central energy metabolic pathways, including glycolysis and the citric acid cycle. As the main energy source, Holospora spp. likely rely on nucleotides pirated from the host. Holospora-specific genes absent from other Rickettsiales are possibly involved in the lifestyle switch from the infectious to the reproductive form and in cell invasion.

  17. Spallation neutron production and the current intra-nuclear cascade and transport codes

    Science.gov (United States)

    Filges, D.; Goldenbaum, F.; Enke, M.; Galin, J.; Herbach, C.-M.; Hilscher, D.; Jahnke, U.; Letourneau, A.; Lott, B.; Neef, R.-D.; Nünighoff, K.; Paul, N.; Péghaire, A.; Pienkowski, L.; Schaal, H.; Schröder, U.; Sterzenbach, G.; Tietze, A.; Tishchenko, V.; Toke, J.; Wohlmuther, M.

    A recent renascent interest in energetic proton-induced production of neutrons originates largely from the inception of projects for target stations of intense spallation neutron sources, like the planned European Spallation Source (ESS), accelerator-driven nuclear reactors, nuclear waste transmutation, and also from the application for radioactive beams. In the framework of such a neutron production, of major importance is the search for ways for the most efficient conversion of the primary beam energy into neutron production. Although the issue has been quite successfully addressed experimentally by varying the incident proton energy for various target materials and by covering a huge collection of different target geometries --providing an exhaustive matrix of benchmark data-- the ultimate challenge is to increase the predictive power of transport codes currently on the market. To scrutinize these codes, calculations of reaction cross-sections, hadronic interaction lengths, average neutron multiplicities, neutron multiplicity and energy distributions, and the development of hadronic showers are confronted with recent experimental data of the NESSI collaboration. Program packages like HERMES, LCS or MCNPX master the prevision of reaction cross-sections, hadronic interaction lengths, averaged neutron multiplicities and neutron multiplicity distributions in thick and thin targets for a wide spectrum of incident proton energies, geometrical shapes and materials of the target generally within less than 10% deviation, while production cross-section measurements for light charged particles on thin targets point out that appreciable distinctions exist within these models.

  18. Spallation neutron production and the current intra-nuclear cascade and transport codes

    International Nuclear Information System (INIS)

    Filges, D.; Goldenbaum, F.

    2001-01-01

    A recent renascent interest in energetic proton-induced production of neutrons originates largely from the inception of projects for target stations of intense spallation neutron sources, like the planned European Spallation Source (ESS), accelerator-driven nuclear reactors, nuclear waste transmutation, and also from the application for radioactive beams. In the framework of such a neutron production, of major importance is the search for ways for the most efficient conversion of the primary beam energy into neutron production. Although the issue has been quite successfully addressed experimentally by varying the incident proton energy for various target materials and by covering a huge collection of different target geometries --providing an exhaustive matrix of benchmark data-- the ultimate challenge is to increase the predictive power of transport codes currently on the market. To scrutinize these codes, calculations of reaction cross-sections, hadronic interaction lengths, average neutron multiplicities, neutron multiplicity and energy distributions, and the development of hadronic showers are confronted with recent experimental data of the NESSI collaboration. Program packages like HERMES, LCS or MCNPX master the prevision of reaction cross-sections, hadronic interaction lengths, averaged neutron multiplicities and neutron multiplicity distributions in thick and thin targets for a wide spectrum of incident proton energies, geometrical shapes and materials of the target generally within less than 10% deviation, while production cross-section measurements for light charged particles on thin targets point out that appreciable distinctions exist within these models. (orig.)

  19. DETECTION OF INTRANUCLEAR COCCIDIOSIS IN TORTOISES IN EUROPE AND CHINA.

    Science.gov (United States)

    Kolesnik, Ekaterina; Dietz, Janosch; Heckers, Kim O; Marschang, Rachel E

    2017-06-01

    Intranuclear coccidiosis of tortoises (TINC) has been described in association with systemic disease in various species of tortoises. TINC has been detected in numerous tortoises from the United States, but there are only a few reports from tropical tortoises in Germany and no reports from Asia. Using a real-time polymerase chain reaction assay, samples from 1,011 tortoises were screened for the presence of TINC. Samples originated from animals kept in captivity in Europe and in China. Coccidia were detected in a total of 27 chelonians (2.7%), including the first description of TINC in a marginated tortoise ( Testudo marginata ), Hermann's tortoise ( Testudo hermanni ), African spurred tortoise (Centrochelys sulcata), and yellow-footed tortoise (Chelonoidis denticulatus). The highest percentage of positive animals was found in radiated tortoises ( Astrochelys radiata ). Although the percentage of positive animals was relatively low, this study demonstrates the global distribution of TINC in captive chelonians as well as expanding the known host range for these pathogens.

  20. Intranuclear localization and UV response of ERCC5/XPG protein

    Energy Technology Data Exchange (ETDEWEB)

    Park, M.S.; Marrone, B.L.; MacInnes, M.A. [Los Alamos National Laboratory, NM (United States)] [and others

    1995-11-01

    The human ERCC5/XPG protein is defective in the hereditary genetic disorder xeroderma pigmentosum, group-G. The XPG gene encodes a single-strand DNA endonuclease which is essential for the incision step of nucleotide excision repair for a wide variety of DNA damages. We have shown previously by indirect immunofluorescence and biochemical fractionation that the XPG protein is localized in the nucleus, in discrete foci, and probably associated with the nuclear matrix. However, the intranuclear localization of XPG is markedly altered for a short time after UV irradiation. Here, we report the identification of XPG protein regions involved in the UV response, and its putative nuclear localization signals (NLS) using a B-galactosidase (B-gal) reporter gene system. Control and fusion reporter genes were expressed in Hela S3 cells after CaPO{sub 4} transfection. B-gal protein was detected by indirect immuno-fluorescence using an anti B-gal monoclonal antibody and FITC-labeled goat anti-mouse antiserum. Two NLS peptides of the XPG carboxy-terminal region (AA 1029-1069 and 1146-1186 term) were shown to independently localize B-gal fusion proteins to the nucleus (>90%). The C-terminus peptide was observed to further localize B-gal into nuclear foci and the perinucleolar regions. When B-gal was fused with two copies of the C-terminal NLS, in tandem, B-gal was extensively sublocalized to the perinucleolar regions. Shortly after cell UV irradiation (5 J/m{sup 2}) this B-gal fusion protein became dissociated from the perinucleolar regions whereupon it was distributed throughout the nucleus. Within 6 hours post-irradiation, the fusion protein reassociated again with the perinucleolar regions. These observations confirm and extend a similar UV response of endogenous XPG protein in UV-irradiation human cells. The involvement of XPG protein and its UV responses will be discussed in context of models nuclear matrix and preferential DNA repair in actively transcribed genes.

  1. Wavelet cascades

    Science.gov (United States)

    Giesemann, Jens; Greiner, Martin; Lipa, Peter

    1997-02-01

    The generators of binary multiplicative cascade models with a non-overlapping branching structure are given by the Haar wavelets. We construct specific generalizations of these models for which any given wavelet represents the generators of the local cascade branchings. Such “wavelet cascades”, for which we calculate spatial correlation functions, have spatially overlapping branches and are therefore useful for modeling recombination effects in hierarchical branching processes.

  2. Massive target nuclei as disc-shaped slabs and spherical objects of intranuclear matter in high-energy nuclear collisions

    International Nuclear Information System (INIS)

    Zewislawski, Z.; Strugalski, Z.; Mausa, M.

    1990-01-01

    It has been found experimentally that a definite number of emitted nucleons corresponds to a definite impact parameter in hadron-nucleus collisions. This finding allows one: to treat the massive target nucleus as a piece of intranuclear matter of a definite thickness; to treat a numerous sample of collisions of monoenergetic identical hadrons with the nucleus as collection of interactions of a homogeneous beam of hadrons with disc-shaped slabs of intranuclear matter of definite thicknesses. 17 refs.; 1 fig

  3. Survival and Intra-Nuclear Trafficking of Burkholderia pseudomallei: Strategies of Evasion from Immune Surveillance?

    Directory of Open Access Journals (Sweden)

    Jamuna Vadivelu

    2017-01-01

    Full Text Available During infection, successful bacterial clearance is achieved via the host immune system acting in conjunction with appropriate antibiotic therapy. However, it still remains a tip of the iceberg as to where persistent pathogens namely, Burkholderia pseudomallei (B. pseudomallei reside/hide to escape from host immune sensors and antimicrobial pressure.We used transmission electron microscopy (TEM to investigate post-mortem tissue sections of patients with clinical melioidosis to identify the localisation of a recently identified gut microbiome, B. pseudomallei within host cells. The intranuclear presence of B. pseudomallei was confirmed using transmission electron microscopy (TEM of experimentally infected guinea pig spleen tissues and Live Z-stack, and ImageJ analysis of fluorescence microscopy analysis of in vitro infection of A549 human lung epithelial cells.TEM investigations revealed intranuclear localization of B. pseudomallei in cells of infected human lung and guinea pig spleen tissues. We also found that B. pseudomallei induced actin polymerization following infection of A549 human lung epithelial cells. Infected A549 lung epithelial cells using 3D-Laser scanning confocal microscopy (LSCM and immunofluorescence microscopy confirmed the intranuclear localization of B. pseudomallei.B. pseudomallei was found within the nuclear compartment of host cells. The nucleus may play a role as an occult or transient niche for persistence of intracellular pathogens, potentially leading to recurrrent episodes or recrudescence of infection.

  4. The nucleoporin Nup98 associates with the intranuclear filamentous protein network of TPR

    Science.gov (United States)

    Fontoura, Beatriz M. A.; Dales, Samuel; Blobel, Günter; Zhong, Hualin

    2001-01-01

    The Nup98 gene codes for several alternatively spliced protein precursors. Two in vitro translated and autoproteolytically cleaved precursors yielded heterodimers of Nup98-6kDa peptide and Nup98-Nup96. TPR (translocated promoter region) is a protein that forms filamentous structures extending from nuclear pore complexes (NPCs) to intranuclear sites. We found that in vitro translated TPR bound to in vitro translated Nup98 and, via Nup98, to Nup96. Double-immunofluorescence microscopy with antibodies to TPR and Nup98 showed colocalization. In confocal sections the nucleolus itself was only weakly stained but there was intensive perinucleolar staining. Striking spike-like structures emanated from this perinucleolar ring and attenuated into thinner structures as they extended to the nuclear periphery. This characteristic staining pattern of the TPR network was considerably enhanced when a myc-tagged pyruvate kinase-6kDa fusion protein was overexpressed in HeLa cells. Double-immunoelectron microscopy of these cells using anti-myc and anti-TPR antibodies and secondary gold-coupled antibodies yielded row-like arrangements of gold particles. Taken together, the immunolocalization data support previous electron microscopical data, suggesting that TPR forms filaments that extend from the NPC to the nucleolus. We discuss the possible implications of the association of Nup98 with this intranuclear TPR network for an intranuclear phase of transport. PMID:11248057

  5. Learning Cascading

    CERN Document Server

    Covert, Michael

    2015-01-01

    This book is intended for software developers, system architects and analysts, big data project managers, and data scientists who wish to deploy big data solutions using the Cascading framework. You must have a basic understanding of the big data paradigm and should be familiar with Java development techniques.

  6. Investigating the intra-nuclear cascade process using the reaction 136Xe on deuterium at 500 AMeV

    Directory of Open Access Journals (Sweden)

    Rejmund F.

    2010-10-01

    Full Text Available More than 600 residual nuclei, formed in the spallation of 136Xe projectiles impinging on deuterium at 500 AMeV of incident energy, have been unambiguously identified and their production cross sections have been determined with high accuracy. By comparing these data to others previously measured for the reactions 136Xe  +  p at 1 AGeV and 136Xe  +  p at 500 AMeV we investigated the role that neutrons play in peripheral collisions and to understand the energy dissipation in frontal collisions in spallation reactions.

  7. Ubiquitin-Positive Intranuclear Inclusions in Neuronal and Glial Cells in a Mouse Model of the Fragile-X Premutation

    Science.gov (United States)

    Wenzel, H. Jürgen; Hunsaker, Michael R.; Greco, Claudia M.; Willemsen, Rob; Berman, Robert F.

    2010-01-01

    Fragile X-associated tremor/ataxia syndrome (FXTAS) is an adult-onset neurodegenerative disorder caused by CGG trinucleotide repeat expansions in the fragile X mental retardation 1 (FMR1) gene. The neuropathological hallmark of the disease is the presence of ubiquitin-positive intranuclear inclusions in neurons and in astrocytes. Ubiquitin-positive intranuclear inclusions have also been found in the neurons of transgenic mice model carrying an expanded CGG(98) trinucleotide repeat of human origin, but have not previously been described in glial cells. Therefore, we used immunocytochemical methods to determine the pathological features of nuclear and/or cytoplasmic inclusions in astrocytes, Bergmann glia and neurons, as well as relationships between inclusion patterns, age, and repeat length in CGG knock-in (KI) mice in comparison with wild type mice. In CGG KI mice, ubiquitin-positive intranuclear inclusions were found in neurons (e.g., pyramidal cells, GABAergic neurons) throughout the brain in cortical and subcortical brain regions; these inclusions increased in number and size with advanced age. Ubiquitin-positive intranuclear inclusions were also present in protoplasmic astrocytes, including Bergmann glia in the cerebellum. The morphology of intranuclear inclusions in CGG KI mice was compared to that of typical inclusions in human neurons and astrocytes in postmortem FXTAS brain tissue. This new finding of previously unreported pathology in astrocytes of CGG KI mice now provides an important mouse model to study astrocyte pathology in human FXTAS. PMID:20051238

  8. C-terminal region of herpes simplex virus ICP8 protein needed for intranuclear localization

    International Nuclear Information System (INIS)

    Taylor, Travis J; Knipe, David M.

    2003-01-01

    The herpes simplex virus single-stranded DNA-binding protein, ICP8, localizes initially to structures in the nucleus called prereplicative sites. As replication proceeds, these sites mature into large globular structures called replication compartments. The details of what signals or proteins are involved in the redistribution of viral and cellular proteins within the nucleus between prereplicative sites and replication compartments are poorly understood; however, we showed previously that the dominant-negative d105 ICP8 does not localize to prereplicative sites and prevents the localization of other viral proteins to prereplicative sites (J. Virol. 74 (2000) 10122). Within the residues deleted in d105 (1083 to 1168), we identified a region between amino acid residues 1080 and 1135 that was predicted by computer models to contain two α-helices, one with considerable amphipathic nature. We used site-specific and random mutagenesis techniques to identify residues or structures within this region that are required for proper ICP8 localization within the nucleus. Proline substitutions in the predicted helix generated ICP8 molecules that did not localize to prereplicative sites and acted as dominant-negative inhibitors. Other substitutions that altered the charged residues in the predicted α-helix to alanine or leucine residues had little or no effect on ICP8 intranuclear localization. The predicted α-helix was dispensable for the interaction of ICP8 with the U L 9 origin-binding protein. We propose that this C-terminal α-helix is required for localization of ICP8 to prereplicative sites by binding viral or cellular factors that target or retain ICP8 at specific intranuclear sites

  9. Intranuclear interactomic inhibition of NF-κB suppresses LPS-induced severe sepsis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung-Dong [Translational Research Center for Protein Function Control, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Cheon, So Yeong [Department of Anesthesiology and Pain Medicine, Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Park, Tae-Yoon; Shin, Bo-Young [Translational Research Center for Protein Function Control, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Oh, Hyunju; Ghosh, Sankar [Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, New York, NY 10032 (United States); Koo, Bon-Nyeo, E-mail: koobn@yuhs.ac [Department of Anesthesiology and Pain Medicine, Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Lee, Sang-Kyou, E-mail: sjrlee@yonsei.ac.kr [Translational Research Center for Protein Function Control, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2015-08-28

    Suppression of nuclear factor-κB (NF-κB) activation, which is best known as a major regulator of innate and adaptive immune responses, is a potent strategy for the treatment of endotoxic sepsis. To inhibit NF-κB functions, we designed the intra-nuclear transducible form of transcription modulation domain (TMD) of RelA (p65), called nt-p65-TMD, which can be delivered effectively into the nucleus without influencing the cell viability, and work as interactomic inhibitors via disruption of the endogenous p65-mediated transcription complex. nt-p65-TMD effectively inhibited the secretion of pro-inflammatory cytokines, including TNF-α, IL-1β, or IL-6 from BV2 microglia cells stimulated by lipopolysaccharide (LPS). nt-p65-TMD did not inhibit tyrosine phosphorylation of signaling mediators such as ZAP-70, p38, JNK, or ERK involved in T cell activation, but was capable of suppressing the transcriptional activity of NF-κB without the functional effect on that of NFAT upon T-cell receptor (TCR) stimulation. The transduced nt-p65-TMD in T cell did not affect the expression of CD69, however significantly inhibited the secretion of T cell-specific cytokines such as IL-2, IFN-γ, IL-4, IL-17A, or IL-10. Systemic administration of nt-p65-TMD showed a significant therapeutic effect on LPS-induced sepsis model by inhibiting pro-inflammatory cytokines secretion. Therefore, nt-p65-TMD can be a novel therapeutics for the treatment of various inflammatory diseases, including sepsis, where a transcription factor has a key role in pathogenesis, and further allows us to discover new functions of p65 under normal physiological condition without genetic alteration. - Highlights: • The nt-p65-TMD is intra-nuclear interactomic inhibitor of endogenous p65. • The nt-p65-TMD effectively inhibited the secretion of pro-inflammatory cytokines. • The excellent therapeutic potential of nt-p65-TMD was confirmed in sepsis model.

  10. Intranuclear interactomic inhibition of NF-κB suppresses LPS-induced severe sepsis

    International Nuclear Information System (INIS)

    Park, Sung-Dong; Cheon, So Yeong; Park, Tae-Yoon; Shin, Bo-Young; Oh, Hyunju; Ghosh, Sankar; Koo, Bon-Nyeo; Lee, Sang-Kyou

    2015-01-01

    Suppression of nuclear factor-κB (NF-κB) activation, which is best known as a major regulator of innate and adaptive immune responses, is a potent strategy for the treatment of endotoxic sepsis. To inhibit NF-κB functions, we designed the intra-nuclear transducible form of transcription modulation domain (TMD) of RelA (p65), called nt-p65-TMD, which can be delivered effectively into the nucleus without influencing the cell viability, and work as interactomic inhibitors via disruption of the endogenous p65-mediated transcription complex. nt-p65-TMD effectively inhibited the secretion of pro-inflammatory cytokines, including TNF-α, IL-1β, or IL-6 from BV2 microglia cells stimulated by lipopolysaccharide (LPS). nt-p65-TMD did not inhibit tyrosine phosphorylation of signaling mediators such as ZAP-70, p38, JNK, or ERK involved in T cell activation, but was capable of suppressing the transcriptional activity of NF-κB without the functional effect on that of NFAT upon T-cell receptor (TCR) stimulation. The transduced nt-p65-TMD in T cell did not affect the expression of CD69, however significantly inhibited the secretion of T cell-specific cytokines such as IL-2, IFN-γ, IL-4, IL-17A, or IL-10. Systemic administration of nt-p65-TMD showed a significant therapeutic effect on LPS-induced sepsis model by inhibiting pro-inflammatory cytokines secretion. Therefore, nt-p65-TMD can be a novel therapeutics for the treatment of various inflammatory diseases, including sepsis, where a transcription factor has a key role in pathogenesis, and further allows us to discover new functions of p65 under normal physiological condition without genetic alteration. - Highlights: • The nt-p65-TMD is intra-nuclear interactomic inhibitor of endogenous p65. • The nt-p65-TMD effectively inhibited the secretion of pro-inflammatory cytokines. • The excellent therapeutic potential of nt-p65-TMD was confirmed in sepsis model

  11. Protein crystals in Adenovirus type 5-infected cells: requirements for intranuclear crystallogenesis, structural and functional analysis.

    Directory of Open Access Journals (Sweden)

    Laure Franqueville

    Full Text Available Intranuclear crystalline inclusions have been observed in the nucleus of epithelial cells infected with Adenovirus serotype 5 (Ad5 at late steps of the virus life cycle. Using immuno-electron microscopy and confocal microscopy of cells infected with various Ad5 recombinants modified in their penton base or fiber domains, we found that these inclusions represented crystals of penton capsomers, the heteromeric capsid protein formed of penton base and fiber subunits. The occurrence of protein crystals within the nucleus of infected cells required the integrity of the fiber knob and part of the shaft domain. In the knob domain, the region overlapping residues 489-492 in the FG loop was found to be essential for crystal formation. In the shaft, a large deletion of repeats 4 to 16 had no detrimental effect on crystal inclusions, whereas deletion of repeats 8 to 21 abolished crystal formation without altering the level of fiber protein expression. This suggested a crucial role of the five penultimate repeats in the crystallisation process. Chimeric pentons made of Ad5 penton base and fiber domains from different serotypes were analyzed with respect to crystal formation. No crystal was found when fiber consisted of shaft (S from Ad5 and knob (K from Ad3 (heterotypic S5-K3 fiber, but occurred with homotypic S3K3 fiber. However, less regular crystals were observed with homotypic S35-K35 fiber. TB5, a monoclonal antibody directed against the Ad5 fiber knob was found by immunofluorescence microscopy to react with high efficiency with the intranuclear protein crystals in situ. Data obtained with Ad fiber mutants indicated that the absence of crystalline inclusions correlated with a lower infectivity and/or lower yields of virus progeny, suggesting that the protein crystals might be involved in virion assembly. Thus, we propose that TB5 staining of Ad-infected 293 cells can be used as a prognostic assay for the viability and productivity of fiber-modified Ad5

  12. Cascade annealing: an overview

    International Nuclear Information System (INIS)

    Doran, D.G.; Schiffgens, J.O.

    1976-04-01

    Concepts and an overview of radiation displacement damage modeling and annealing kinetics are presented. Short-term annealing methodology is described and results of annealing simulations performed on damage cascades generated using the Marlowe and Cascade programs are included. Observations concerning the inconsistencies and inadequacies of current methods are presented along with simulation of high energy cascades and simulation of longer-term annealing

  13. Improving nuclear envelope dynamics by EBV BFRF1 facilitates intranuclear component clearance through autophagy.

    Science.gov (United States)

    Liu, Guan-Ting; Kung, Hsiu-Ni; Chen, Chung-Kuan; Huang, Cheng; Wang, Yung-Li; Yu, Cheng-Pu; Lee, Chung-Pei

    2018-02-26

    Although a vesicular nucleocytoplasmic transport system is believed to exist in eukaryotic cells, the features of this pathway are mostly unknown. Here, we report that the BFRF1 protein of the Epstein-Barr virus improves vesicular transport of nuclear envelope (NE) to facilitate the translocation and clearance of nuclear components. BFRF1 expression induces vesicles that selectively transport nuclear components to the cytoplasm. With the use of aggregation-prone proteins as tools, we found that aggregated nuclear proteins are dispersed when these BFRF1-induced vesicles are formed. BFRF1-containing vesicles engulf the NE-associated aggregates, exit through from the NE, and putatively fuse with autophagic vacuoles. Chemical treatment and genetic ablation of autophagy-related factors indicate that autophagosome formation and autophagy-linked FYVE protein-mediated autophagic proteolysis are involved in this selective clearance of nuclear proteins. Remarkably, vesicular transport, elicited by BFRF1, also attenuated nuclear aggregates accumulated in neuroblastoma cells. Accordingly, induction of NE-derived vesicles by BFRF1 facilitates nuclear protein translocation and clearance, suggesting that autophagy-coupled transport of nucleus-derived vesicles can be elicited for nuclear component catabolism in mammalian cells.-Liu, G.-T., Kung, H.-N., Chen, C.-K., Huang, C., Wang, Y.-L., Yu, C.-P., Lee, C.-P. Improving nuclear envelope dynamics by EBV BFRF1 facilitates intranuclear component clearance through autophagy.

  14. Degeneração oxychromatica ("inclusões intranucleares" na febre amarella

    Directory of Open Access Journals (Sweden)

    C. Magarinos Torres

    1931-05-01

    ção oxychromatica (figs. 37 e 40; são escassos e de caracterisação duvidosa em virtude da concomitancia de alterações necrobíoticas não específicas. 2- Durante a epidemia de febre amarella em 1928 no Rio de Janeiro, notamos differenças assaz pronunciadas entre as lesões hepaticas no homem e no M. rhesus. Taes differenças, existindo em material assaz homogeneo quanto ás amostras de virus em questão, nos levam a concluir que a capacidade de formar corpusculos intranucleares especificos, como tambem a já conhecida permanencia do virus no sangue e nos tecidos, depende, de modo evidente, da especie animal usada e não da propria amostra empregada, nem do numero de passagens que ella soffreu no macaco. Embora os doentes pertencessem a raças differentes (quadro VIII e embora, possivelmente diversas amostras de virus tenham sido nelles inoculadas, estamos autorisados a concluir que a amostra ou amostras que infectaram o homem na epidemia de 1928, no Rio de janeiro, possuem nelle uma fraca capacidade de determinar inclusões intranucleares. Ao contrario, a mesma amostra ou amostras são capazes de produzir no M. rhesus, logo na primeira passagem, inclusões intranucleares assaz abundantes. Outra diferença que notamos e attribuimos a especie animal empregada foi; as alterações hepaticas de natureza toxica e circulatoria (congestão, necrose e necrobiose da cellula hepatica são nitidamente mais intensas no homem que nos macacos injectados com as amostras brasileiras do virus da febre amarella isoladas durante a epidemia de 1928 no Rio de Janeiro. Conseguimos, no homem, evidencia de inclusões typicas na cellula hepatica, apenas em tres casos dentre dezesete examinados. Esse resultado, provavelmente, ainda não é definitivo, indicando, apenas a raridade extrema que os corpusculos podem apresentar nos casos de febre amarella que ordinariamente chegam á autopsia. Tambem não realisamos uma pesquiza exhaustiva dos corpusculos em outros orgãos além do figado. O caso no qual

  15. Fitness Impact of Obligate Intranuclear Bacterial Symbionts Depends on Host Growth Phase.

    Science.gov (United States)

    Bella, Chiara; Koehler, Lars; Grosser, Katrin; Berendonk, Thomas U; Petroni, Giulio; Schrallhammer, Martina

    2016-01-01

    According to text book definition, parasites reduce the fitness of their hosts whereas mutualists provide benefits. But biotic and abiotic factors influence symbiotic interactions, thus under certain circumstances parasites can provide benefits and mutualists can harm their host. Here we addressed the question which intrinsic biotic factors shape a symbiosis and are crucial for the outcome of the interaction between the obligate intranuclear bacterium Holospora caryophila ( Alphaproteobacteria; Rickettsiales ) and its unicellular eukaryotic host Paramecium biaurelia (Alveolata; Ciliophora). The virulence of H. caryophila , i.e., the negative fitness effect on host division and cell number, was determined by growth assays of several P. biaurelia strains. The performances of genetically identical lines either infected with H. caryophila or symbiont-free were compared. Following factors were considered as potentially influencing the outcome of the interaction: (1) host strain, (2) parasite strain, and (3) growth phases of the host. All three factors revealed a strong effect on the symbiosis. In presence of H. caryophila , the Paramecium density in the stationary growth phase decreased. Conversely, a positive effect of the bacteria during the exponential phase was observed for several host × parasite combinations resulting in an increased growth rate of infected P. biaurelia . Furthermore, the fitness impact of the tested endosymbionts on different P. biaurelia lines was not only dependent on one of the two involved strains but distinct for the specific combination. Depending on the current host growth phase, the presence of H. caryophila can be harmful or advantageous for P. biaurelia . Thus, under the tested experimental conditions, the symbionts can switch from the provision of benefits to the exploitation of host resources within the same host population and a time-span of less than 6 days.

  16. The Cascade-Exciton Approach to Nuclear Reactions. (Foundation and Achievements)

    International Nuclear Information System (INIS)

    Mashnik, S.G.

    1994-01-01

    The relativistic kinetic equations describing nuclear reactions at intermediate energies are obtained on the dynamical basis. These equations are analyzed and realized in several versions of the Cascade Exciton Model (CEM). The CEM assumes that reactions occur in three stages: the intranuclear cascade, pre-equilibrium and the evaporative ones. A large variety of experimental data on hadron- and photonuclear reactions in the bombarding energy range up to several GeV are analyzed in this approach. The contributions of different pion and photon absorption mechanisms and the relative role of different particle and photon production mechanisms in these reactions are estimated. The CEM describes adequately nuclear reactions at intermediate energies and has one of the best predictive powers as compared to other available modern models. 55 refs., 10 figs., 1 tab

  17. Deep cascade learning

    OpenAIRE

    Marquez, Enrique, Salvador; Hare, Jonathon; Niranjan, Mahesan

    2018-01-01

    In this paper, we propose a novel approach for efficient training of deep neural networks in a bottom-up fashion using a layered structure. Our algorithm, which we refer to as Deep Cascade Learning, is motivated by the Cascade Correlation approach of Fahlman who introduced it in the context of perceptrons. We demonstrate our algorithm on networks of convolutional layers, though its applicability is more general. Such training of deep networks in a cascade, directly circumvents the well-know...

  18. Cascaded automatic target recognition (Cascaded ATR)

    Science.gov (United States)

    Walls, Bradley

    2010-04-01

    The global war on terror has plunged US and coalition forces into a battle space requiring the continuous adaptation of tactics and technologies to cope with an elusive enemy. As a result, technologies that enhance the intelligence, surveillance, and reconnaissance (ISR) mission making the warfighter more effective are experiencing increased interest. In this paper we show how a new generation of smart cameras built around foveated sensing makes possible a powerful ISR technique termed Cascaded ATR. Foveated sensing is an innovative optical concept in which a single aperture captures two distinct fields of view. In Cascaded ATR, foveated sensing is used to provide a coarse resolution, persistent surveillance, wide field of view (WFOV) detector to accomplish detection level perception. At the same time, within the foveated sensor, these detection locations are passed as a cue to a steerable, high fidelity, narrow field of view (NFOV) detector to perform recognition level perception. Two new ISR mission scenarios, utilizing Cascaded ATR, are proposed.

  19. Familial frontotemporal dementia with neuronal intranuclear inclusions is not a polyglutamine expansion disease

    Directory of Open Access Journals (Sweden)

    Neal Scott J

    2006-08-01

    Full Text Available Abstract Background Many cases of frontotemporal dementia (FTD are familial, often with an autosomal dominant pattern of inheritance. Some are due to a mutation in the tau- encoding gene, on chromosome 17, and show an accumulation of abnormal tau in brain tissue (FTDP-17T. Most of the remaining familial cases do not exhibit tau pathology, but display neuropathology similar to patients with dementia and motor neuron disease, characterized by the presence of ubiquitin-immunoreactive (ub-ir, dystrophic neurites and neuronal cytoplasmic inclusions in the neocortex and hippocampus (FTLD-U. Recently, we described a subset of patients with familial FTD with autopsy-proven FTLD-U pathology and with the additional finding of ub-ir neuronal intranuclear inclusions (NII. NII are a characteristic feature of several other neurodegenerative conditions for which the genetic basis is abnormal expansion of a polyglutamine-encoding trinucleotide repeat region. The genetic basis of familial FTLD-U is currently not known, however the presence of NII suggests that a subset of cases may represent a polyglutamine expansion disease. Methods We studied DNA and post mortem brain tissue from 5 affected members of 4 different families with NII and one affected individual with familial FTLD-U without NII. Patient DNA was screened for CAA/CAG trinucleotide expansion in a set of candidate genes identified using a genome-wide computational approach. Genes containing CAA/CAG trinucleotide repeats encoding at least five glutamines were examined (n = 63, including the nine genes currently known to be associated with human disease. CAA/CAG tract sizes were compared with published normal values (where available and with those of healthy controls (n = 94. High-resolution agarose gel electrophoresis was used to measure allele size (number of CAA/CAG repeats. For any alleles estimated to be equal to or larger than the maximum measured in the control population, the CAA/CAG tract

  20. Mechanisms of cascade collapse

    International Nuclear Information System (INIS)

    Diaz de la Rubia, T.; Smalinskas, K.; Averback, R.S.; Robertson, I.M.; Hseih, H.; Benedek, R.

    1988-12-01

    The spontaneous collapse of energetic displacement cascades in metals into vacancy dislocation loops has been investigated by molecular dynamics (MD) computer simulation and transmission electron microscopy (TEM). Simulations of 5 keV recoil events in Cu and Ni provide the following scenario of cascade collapse: atoms are ejected from the central region of the cascade by replacement collision sequences; the central region subsequently melts; vacancies are driven to the center of the cascade during resolidification where they may collapse into loops. Whether or not collapse occurs depends critically on the melting temperature of the metal and the energy density and total energy in the cascade. Results of TEM are presented in support of this mechanism. 14 refs., 4 figs., 1 tab

  1. Hsp70 chaperones and type I PRMTs are sequestered at intranuclear inclusions caused by polyalanine expansions in PABPN1.

    Directory of Open Access Journals (Sweden)

    João Paulo Tavanez

    2009-07-01

    Full Text Available Genomic instability at loci with tandem arrays of simple repeats is the cause for many neurological, neurodegenerative and neuromuscular diseases. When located in coding regions, disease-associated expansions of trinucleotide repeats are translated into homopolymeric amino acid stretches of glutamine or alanine. Polyalanine expansions in the poly(A-binding protein nuclear 1 (PABPN1 gene causes oculopharyngeal muscular dystrophy (OPMD. To gain novel insight into the molecular pathophysiology of OPMD, we studied the interaction of cellular proteins with normal and expanded PABPN1. Pull-down assays show that heat shock proteins including Hsp70, and type I arginine methyl transferases (PRMT1 and PRMT3 associate preferentially with expanded PABPN1. Immunofluorescence microscopy further reveals accumulation of these proteins at intranuclear inclusions in muscle from OPMD patients. Recombinant PABPN1 with expanded polyalanine stretches binds Hsp70 with higher affinity, and data from molecular simulations suggest that expansions of the PABPN1 polyalanine tract result in transition from a disordered, flexible conformation to a stable helical secondary structure. Taken together, our results suggest that the pathological mutation in the PABPN1 gene alters the protein conformation and induces a preferential interaction with type I PRMTs and Hsp70 chaperones. This in turn causes sequestration in intranuclear inclusions, possibly leading to a progressive cellular defect in arginine methylation and chaperone activity.

  2. Biocatalysis: Chiral cascades

    Science.gov (United States)

    Wang, Jian-Bo; Reetz, Manfred T.

    2015-12-01

    Racemic or enantiomerically pure alcohols can be converted with high yield into enantiopure chiral amines in a one-pot redox-neutral cascade process by the clever combination of an alcohol dehydrogenase and an appropriate amine dehydrogenase.

  3. Conjugation of cascades

    International Nuclear Information System (INIS)

    San Martin, Jesus; Rodriguez-Perez, Daniel

    2009-01-01

    Presented in this work are some results relative to sequences found in the logistic equation bifurcation diagram, which is the unimodal quadratic map prototype. All of the different saddle-node bifurcation cascades, associated with every last appearance p-periodic orbit (p=3,4,5,...), can also be generated from the very Feigenbaum cascade. In this way it is evidenced the relationship between both cascades. The orbits of every saddle-node bifurcation cascade, mentioned above, are located in different chaotic bands, and this determines a sequence of orbits converging to every band-merging Misiurewicz point. In turn, these accumulation points form a sequence whose accumulation point is the Myrberg-Feigenbaum point. It is also proven that the first appearance orbits in the n-chaotic band converge to the same point as the last appearance orbits of the (n + 1)-chaotic band. The symbolic sequences of band-merging Misiurewicz points are computed for any window.

  4. Learning optimal embedded cascades.

    Science.gov (United States)

    Saberian, Mohammad Javad; Vasconcelos, Nuno

    2012-10-01

    The problem of automatic and optimal design of embedded object detector cascades is considered. Two main challenges are identified: optimization of the cascade configuration and optimization of individual cascade stages, so as to achieve the best tradeoff between classification accuracy and speed, under a detection rate constraint. Two novel boosting algorithms are proposed to address these problems. The first, RCBoost, formulates boosting as a constrained optimization problem which is solved with a barrier penalty method. The constraint is the target detection rate, which is met at all iterations of the boosting process. This enables the design of embedded cascades of known configuration without extensive cross validation or heuristics. The second, ECBoost, searches over cascade configurations to achieve the optimal tradeoff between classification risk and speed. The two algorithms are combined into an overall boosting procedure, RCECBoost, which optimizes both the cascade configuration and its stages under a detection rate constraint, in a fully automated manner. Extensive experiments in face, car, pedestrian, and panda detection show that the resulting detectors achieve an accuracy versus speed tradeoff superior to those of previous methods.

  5. Cascade Organic Solar Cells

    KAUST Repository

    Schlenker, Cody W.

    2011-09-27

    We demonstrate planar organic solar cells consisting of a series of complementary donor materials with cascading exciton energies, incorporated in the following structure: glass/indium-tin-oxide/donor cascade/C 60/bathocuproine/Al. Using a tetracene layer grown in a descending energy cascade on 5,6-diphenyl-tetracene and capped with 5,6,11,12-tetraphenyl- tetracene, where the accessibility of the π-system in each material is expected to influence the rate of parasitic carrier leakage and charge recombination at the donor/acceptor interface, we observe an increase in open circuit voltage (Voc) of approximately 40% (corresponding to a change of +200 mV) compared to that of a single tetracene donor. Little change is observed in other parameters such as fill factor and short circuit current density (FF = 0.50 ± 0.02 and Jsc = 2.55 ± 0.23 mA/cm2) compared to those of the control tetracene-C60 solar cells (FF = 0.54 ± 0.02 and Jsc = 2.86 ± 0.23 mA/cm2). We demonstrate that this cascade architecture is effective in reducing losses due to polaron pair recombination at donor-acceptor interfaces, while enhancing spectral coverage, resulting in a substantial increase in the power conversion efficiency for cascade organic photovoltaic cells compared to tetracene and pentacene based devices with a single donor layer. © 2011 American Chemical Society.

  6. Hadron cascades produced by electromagnetic cascades

    International Nuclear Information System (INIS)

    Nelson, W.R.; Jenkins, T.M.; Ranft, J.

    1986-12-01

    A method for calculating high energy hadron cascades induced by multi-GeV electron and photon beams is described. Using the EGS4 computer program, high energy photons in the EM shower are allowed to interact hadronically according to the vector meson dominance (VMD) model, facilitated by a Monte Carlo version of the dual multistring fragmentation model which is used in the hadron cascade code FLUKA. The results of this calculation compare very favorably with experimental data on hadron production in photon-proton collisions and on the hadron production by electron beams on targets (i.e., yields in secondary particle beam lines). Electron beam induced hadron star density contours are also presented and are compared with those produced by proton beams. This FLUKA-EGS4 coupling technique could find use in the design of secondary beams, in the determination high energy hadron source terms for shielding purposes, and in the estimation of induced radioactivity in targets, collimators and beam dumps

  7. Citoquímica de inclusões intranucleares associadas ao vírus do mosaico amarelo do salsão Cytochemical studies of the intranuclear inclusions associated with the celery yellow mosaic virus (CYMV

    Directory of Open Access Journals (Sweden)

    Neusa D. da Cruz

    1972-01-01

    Full Text Available Estudos citoquímicos, ao nível do microscópio óptico, foram efetuados para determinar a natureza química de inclusões intranucleares, de aspecto fibroso, induzidas pelo vírus do mosaico amarelo do salsão na maioria de suas hospedeiras. Os testes citoquímicos foram conduzidos em material foliar fresco ou fixado (aldeído glutárico, Carnoy 3:1 ou Bouin, tendo sido feitas as seguintes reações: hematoxilina férrica (testemunha; Sudan IV e Azul do Nilo (lipídios; iodo-iodeto (amido; Feulgen, Azur B e verde-de-metila-pironina (ácidos nucleicos; ninidrina-Schiff e "Fast Green", este último em soluções ácida e alcalina (proteínas. Os testes com verde-de-metila-pironina, Azur B e ninidrina-Schiff foram combinados com digestão enzimática pela ribonuclease ou pepsina. Os dados obtidos sugerem que, dentro da sensibilidade dos testes realizados, a inclusão contenha proteína, mas não tenha amido, lipídios ou ácidos nucleicos. Isso permite supor, portanto, que essas inclusões não sejam formadas de partículas de vírus.Cytochemical studies at optical microscopic level were made to determine the chemical nature of intranuclear inclusions with fibrous aspect which were induced by the celery yellow mosaic virus (CYMV in most of its hosts. The cytochemical tests were carried on fresh as well on fixed foliar material, fixation being in glutaric aldeid, Carnoy 3:1 or Bouin. The following reactions were tried: ferric haematoxylin (control; Sudan IV and Nile blue (for lipids; iodine ioduret (for starch; Feulgen, azur B and methyl green-pyronin (for nucleic acids; ninhydrin-Schiff and fast-green, the latter in acid and in alcaline solution (for protein. The tests with methyl green-pyronin, azur B and ninhydrin-Schiff were combined with enzimatic digestion with RNase or pepsin. The results suggest that, within the sensibility of the tests, the inclusion contains protein but does not contain starch, lipids or nucleic acids. This permit to

  8. Quantitative analysis of nanoscale intranuclear structural alterations in hippocampal cells in chronic alcoholism via transmission electron microscopy imaging

    Science.gov (United States)

    Sahay, Peeyush; Shukla, Pradeep K.; Ghimire, Hemendra M.; Almabadi, Huda M.; Tripathi, Vibha; Mohanty, Samarendra K.; Rao, Radhakrishna; Pradhan, Prabhakar

    2017-04-01

    Chronic alcoholism is known to alter the morphology of the hippocampus, an important region of cognitive function in the brain. Therefore, to understand the effect of chronic alcoholism on hippocampal neural cells, we employed a mouse model of chronic alcoholism and quantified intranuclear nanoscale structural alterations in these cells. Transmission electron microscopy (TEM) images of hippocampal neurons were obtained, and the degree of structural alteration in terms of mass density fluctuation was determined using the light-localization properties of optical media generated from TEM imaging. The results, which were obtained at length scales ranging from ~30 to 200 nm, show that 10-12 week-old mice fed a Lieber-DeCarli liquid (alcoholic) diet had a higher degree of structural alteration than control mice fed a normal diet without alcohol. The degree of structural alteration became significantly distinguishable at a sample length of ~100 nm, which is the typical length scale of the building blocks of cells, such as DNA, RNA, proteins and lipids. Interestingly, different degrees of structural alteration at such length scales suggest possible structural rearrangement of chromatin inside the nuclei in chronic alcoholism.

  9. Cascading Corruption News

    DEFF Research Database (Denmark)

    Damgaard, Mads

    2018-01-01

    Through a content analysis of 8,800 news items and six months of front pages in three Brazilian newspapers, all dealing with corruption and political transgression, this article documents the remarkable skew of media attention to corruption scandals. The bias is examined as an information...... phenomenon, arising from systemic and commercial factors of Brazil’s news media: An information cascade of news on corruption formed, destabilizing the governing coalition and legitimizing the impeachment process of Dilma Rousseff. As this process gained momentum, questions of accountability were disregarded...... by the media, with harmful effects on democracy....

  10. Cascading Corruption News

    DEFF Research Database (Denmark)

    Damgaard, Mads

    2018-01-01

    Through a content analysis of 8,800 news items and six months of front pages in three Brazilian newspapers, all dealing with corruption and political transgression, this article documents the remarkable skew of media attention to corruption scandals. The bias is examined as an information...... phenomenon, arising from systemic and commercial factors of Brazil’s news media: An information cascade of news on corruption formed, destabilizing the governing coalition and legitimizing the impeachment process of Dilma Rousseff. As this process gained momentum, questions of accountability were disregarded...

  11. In vivo monitoring of intranuclear p27{sup kip1} protein expression in breast cancer cells during trastuzumab (Herceptin) therapy

    Energy Technology Data Exchange (ETDEWEB)

    Cornelissen, Bart [Division of Nuclear Medicine, University Health Network, Toronto, ON, Canada M5S 3E2 (Canada); Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, M5S 3M2 (Canada); MRC/CRUK Gray Institute for Radiation Oncology and Biology, Oxford University, OX3 7LJ Oxford (United Kingdom)], E-mail: bart.cornelissen@rob.ox.ac.uk; Kersemans, Veerle; McLarty, Kristin [Division of Nuclear Medicine, University Health Network, Toronto, ON, M5S 3E2 (Canada); Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, M5S 3M2 (Canada); Tran, Lara [Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, M5S 3M2 (Canada); Vallis, Katherine A. [MRC/CRUK Gray Institute for Radiation Oncology and Biology, Oxford University, OX3 7LJ Oxford (United Kingdom); Reilly, Raymond M. [Division of Nuclear Medicine, University Health Network, Toronto, ON, M5S 3E2 (Canada); Department of Medical Imaging, University of Toronto, Toronto, ON, M5S 3E2 (Canada); Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, M5S 3M2 (Canada)

    2009-10-15

    Introduction: Trastuzumab, a humanized antibody directed against the Her2 receptor, induces the expression of p27{sup kip1}, an intranuclear cyclin-dependent kinase inhibitor in some breast cancer cells. The aim of this study was to develop a radioimmunoconjugate (RIC) to monitor trastuzumab-induced p27{sup kip1} protein up-regulation in vivo. Materials and Methods: Anti-p27{sup kip1} IgG was purified, and conjugated to diethylenetriaminopentaacetate, to allow radiolabeling with {sup 111}In for in vivo detection. Then tat peptide (GRKKRRQRRRPPQGYG), containing a nuclear localization sequence (underlined), was conjugated to the Fc-domain of IgG, using NaIO{sub 4} oxidation of carbohydrates and the resulting Schiff base stabilized with NaCNBH{sub 3}. The conjugate was radiolabeled with {sup 111}In, yielding [{sup 111}In]-anti-p27{sup kip1}-tat. {sup 111}In labeling efficiency, purity and p27{sup kip1} binding were measured. Trastuzumab-induced p27{sup kip1} up-regulation was assessed in a panel of breast cancer cell lines by Western blot analysis. Uptake and retention of [{sup 111}In]-anti-p27{sup kip1}-tat were measured in MDA-MB-361 and SKBr3 cells after exposure to trastuzumab. Uptake of [{sup 111}In]-anti-p27{sup kip1}-tat was determined at 72 h postintravenous injection in MDA-MB-361 xenografts in athymic mice treated with trastuzumab or saline. Results: [{sup 111}In]-anti-p27{sup kip1}-tat was synthesized to 97% purity. The RIC was able to bind to p27{sup kip1} protein and internalized in the cells and was transported to the nuclei of MDA-MB-361 cells. The level of p27{sup kip1} protein in MDA-MB-361 cells was increased after exposure to clinically relevant doses of trastuzumab for 3 days. Trastuzumab-mediated induction of p27{sup kip1} was not associated with increased cellular uptake or nuclear localization of [{sup 111}In]-anti-p27{sup kip1}-tat (6.53{+-}0.61% vs. 6.98{+-}1.36% internalized into trastuzumab-treated vs. control cells, respectively). However

  12. Cascade Error Projection Learning Algorithm

    Science.gov (United States)

    Duong, T. A.; Stubberud, A. R.; Daud, T.

    1995-01-01

    A detailed mathematical analysis is presented for a new learning algorithm termed cascade error projection (CEP) and a general learning frame work. This frame work can be used to obtain the cascade correlation learning algorithm by choosing a particular set of parameters.

  13. Interband cascade lasers

    International Nuclear Information System (INIS)

    Vurgaftman, I; Meyer, J R; Canedy, C L; Kim, C S; Bewley, W W; Merritt, C D; Abell, J; Weih, R; Kamp, M; Kim, M; Höfling, S

    2015-01-01

    We review the current status of interband cascade lasers (ICLs) emitting in the midwave infrared (IR). The ICL may be considered the hybrid of a conventional diode laser that generates photons via electron–hole recombination, and an intersubband-based quantum cascade laser (QCL) that stacks multiple stages for enhanced current efficiency. Following a brief historical overview, we discuss theoretical aspects of the active region and core designs, growth by molecular beam epitaxy, and the processing of broad-area, narrow-ridge, and distributed feedback (DFB) devices. We then review the experimental performance of pulsed broad area ICLs, as well as the continuous-wave (cw) characteristics of narrow ridges having good beam quality and DFBs producing output in a single spectral mode. Because the threshold drive powers are far lower than those of QCLs throughout the λ = 3–6 µm spectral band, ICLs are increasingly viewed as the laser of choice for mid-IR laser spectroscopy applications that do not require high output power but need to be hand-portable and/or battery operated. Demonstrated ICL performance characteristics to date include threshold current densities as low as 106 A cm −2 at room temperature (RT), cw threshold drive powers as low as 29 mW at RT, maximum cw operating temperatures as high as 118 °C, maximum cw output powers exceeding 400 mW at RT, maximum cw wallplug efficiencies as high as 18% at RT, maximum cw single-mode output powers as high as 55 mW at RT, and single-mode output at λ = 5.2 µm with a cw drive power of only 138 mW at RT. (topical review)

  14. Interband cascade lasers

    Science.gov (United States)

    Vurgaftman, I.; Weih, R.; Kamp, M.; Meyer, J. R.; Canedy, C. L.; Kim, C. S.; Kim, M.; Bewley, W. W.; Merritt, C. D.; Abell, J.; Höfling, S.

    2015-04-01

    We review the current status of interband cascade lasers (ICLs) emitting in the midwave infrared (IR). The ICL may be considered the hybrid of a conventional diode laser that generates photons via electron-hole recombination, and an intersubband-based quantum cascade laser (QCL) that stacks multiple stages for enhanced current efficiency. Following a brief historical overview, we discuss theoretical aspects of the active region and core designs, growth by molecular beam epitaxy, and the processing of broad-area, narrow-ridge, and distributed feedback (DFB) devices. We then review the experimental performance of pulsed broad area ICLs, as well as the continuous-wave (cw) characteristics of narrow ridges having good beam quality and DFBs producing output in a single spectral mode. Because the threshold drive powers are far lower than those of QCLs throughout the λ = 3-6 µm spectral band, ICLs are increasingly viewed as the laser of choice for mid-IR laser spectroscopy applications that do not require high output power but need to be hand-portable and/or battery operated. Demonstrated ICL performance characteristics to date include threshold current densities as low as 106 A cm-2 at room temperature (RT), cw threshold drive powers as low as 29 mW at RT, maximum cw operating temperatures as high as 118 °C, maximum cw output powers exceeding 400 mW at RT, maximum cw wallplug efficiencies as high as 18% at RT, maximum cw single-mode output powers as high as 55 mW at RT, and single-mode output at λ = 5.2 µm with a cw drive power of only 138 mW at RT.

  15. A new intranuclear microsporidium, Enterospora nucleophila n. sp., causing an emaciative syndrome in a piscine host (Sparus aurata), prompts the redescription of the family Enterocytozoonidae.

    Science.gov (United States)

    Palenzuela, Oswaldo; Redondo, María José; Cali, Ann; Takvorian, Peter M; Alonso-Naveiro, María; Alvarez-Pellitero, Pilar; Sitjà-Bobadilla, Ariadna

    2014-03-01

    The presence of a new microsporidium is believed to be responsible for an emaciative syndrome observed in farmed gilthead sea bream (Sparus aurata) from different facilities along the Spanish coast. Infected fish were approximately half the average weight and significant mortality was attributed to the condition in some facilities. Clinical signs included anorexia, cachexia and pale internal organs. The microsporidium was found mainly in the intestinal mucosa and occasionally in the submucosa. Morphological, histopathological, ultrastructural and molecular phylogenetic studies were conducted to characterise this organism. This microsporidium undergoes intranuclear development in rodlet cells and enterocytes, and cytoplasmic development mainly in enterocytes and macrophages. The nucleus-infecting plasmodium contains several diplokarya and displays polysporous development which occurs without an interfacial envelope. In the host cell cytoplasm, the parasite develops within a membrane-bound matrix. In both infection locations, the polar tube precursors appear as disks, first with lucent centres, then as fully dense disks as they fuse to form the polar filament, all before division of the plasmodium into sporoblasts. Up to 16 intranuclear spores result from the sporogonic development of a single plasmodium, whereas more than 40 spores result from several asynchronous reproductive cycles in the cytoplasmic infection. Fixed spores are ellipsoidal and diplokaryotic, with five to six coils of an isofilar polar filament in a single row. ssrDNA-based molecular phylogenetic inference places this parasite as a sister clade to crustacean-infecting species of the Enterocytozoonidae and closer to Enterocytozoon bieneusi than to other fish-infecting microsporidians presenting intranuclear development, i.e. Nucleospora, Paranucleospora and Desmozoon. Our studies result in the erection of a new species, Enterospora nucleophila, within the family Enterocytozoonidae, and the

  16. Cascade Mountain Range in Oregon

    Science.gov (United States)

    Sherrod, David R.

    2016-01-01

    The Cascade mountain system extends from northern California to central British Columbia. In Oregon, it comprises the Cascade Range, which is 260 miles long and, at greatest breadth, 90 miles wide (fig. 1). Oregon’s Cascade Range covers roughly 17,000 square miles, or about 17 percent of the state, an area larger than each of the smallest nine of the fifty United States. The range is bounded on the east by U.S. Highways 97 and 197. On the west it reaches nearly to Interstate 5, forming the eastern margin of the Willamette Valley and, farther south, abutting the Coast Ranges. 

  17. Inferring network structure from cascades

    Science.gov (United States)

    Ghonge, Sushrut; Vural, Dervis Can

    2017-07-01

    Many physical, biological, and social phenomena can be described by cascades taking place on a network. Often, the activity can be empirically observed, but not the underlying network of interactions. In this paper we offer three topological methods to infer the structure of any directed network given a set of cascade arrival times. Our formulas hold for a very general class of models where the activation probability of a node is a generic function of its degree and the number of its active neighbors. We report high success rates for synthetic and real networks, for several different cascade models.

  18. Cascade orificial resistive device

    Science.gov (United States)

    Bitsakis, Nicholas; Cassidy, James

    1994-07-01

    A cascade orificial resistive device for throttling fluid flow which minimizes acoustic noise and internal vibrations is described herein. The device has a hollow body defining a fluid passageway, a plurality of perforated plates mounted within the passageway, a fixed end ring adjacent one end of the perforated plates, and a threadable end ring adjacent an opposite end of the perforated plates to place the plates in compression. Each of the perforated plates is a single piece molded plate having an integral outer ring and an integrally formed center keying mechanism as well as a plurality of orifices. The keying mechanism formed on each plate is designed so that adjacent ones of the plates have their orifices misaligned. In this manner, a pressure drop across each plate is created and the fluid flow through the device is throttled. The device of the present invention has utility in a number of onboard marine vessel systems wherein reduced acoustic noise and internal vibrations are particularly desirable.

  19. Arginine-rich cross-linking peptides with different SV40 nuclear localization signal content as vectors for intranuclear DNA delivery.

    Science.gov (United States)

    Bogacheva, Mariia; Egorova, Anna; Slita, Anna; Maretina, Marianna; Baranov, Vladislav; Kiselev, Anton

    2017-11-01

    The major barriers for intracellular DNA transportation by cationic polymers are their toxicity, poor endosomal escape and inefficient nuclear uptake. Therefore, we designed novel modular peptide-based carriers modified with SV40 nuclear localization signal (NLS). Core peptide consists of arginine, histidine and cysteine residues for DNA condensation, endosomal escape promotion and interpeptide cross-linking, respectively. We investigated three polyplexes with different NLS content (10 mol%, 50 mol% and 90 mol% of SV40 NLS) as vectors for intranuclear DNA delivery. All carriers tested were able to condense DNA, to protect it from DNAase I and were not toxic to the cells. We observed that cell cycle arrest by hydroxyurea did not affect transfection efficacy of NLS-modified carriers which we confirmed using quantitative confocal microscopy analysis. Overall, peptide carrier modified with 90 mol% of SV40 NLS provided efficient transfection and nuclear uptake in non-dividing cells. Thus, incorporation of NLS into arginine-rich cross-linking peptides is an adequate approach to the development of efficient intranuclear gene delivery vehicles. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Ultrarelativistic cascades and strangeness production

    International Nuclear Information System (INIS)

    Kahana, D.E.; Kahana, S.H.

    1998-01-01

    A two-phase cascade code, LUCIFER II, developed for the treatment of ultra high energy-ion-ion collisions is applied to the production of strangeness at SPS energies √(s)=17-20. This simulation is able to simultaneously describe both hard processes such as Drell-Yan and slower, soft processes such as the production of light mesons by separating the dynamics into two steps, a fast cascade involving only the nucleons in the original colliding relativistic ions followed, after an appropriate delay, by a normal multiscattering of the resulting excited baryons and mesons produced virtually in the first step. No energy loss can take place in the short time interval over which the first cascade takes place. The chief result is a reconciliation of the important Drell-Yan measurements with the apparent success of standard cascades to describe the nucleon stopping and meson production in heavy-ion experiments at the CERN SPS. (orig.)

  1. Ultrarelativistic cascades and strangeness production

    Energy Technology Data Exchange (ETDEWEB)

    Kahana, D.E. [State Univ. of New York, Stony Brook, NY (United States). Physics Dept.; Kahana, S.H. [Brookhaven National Lab., Upton, NY (United States). Physics Dept.

    1998-02-01

    A two phase cascade, LUCIFER II, developed for the treatment of ultra high energy Ion-Ion collisions is applied to the production of strangeness at SPS energies. This simulation is able to simultaneously describe both hard processes such as Drell-Yan and slower, soft processes such as the production of light mesons by separating the dynamics into two steps, a fast cascade involving only the nucleons in the original colliding relativistic ions followed, after an appropriate delay, by a normal multiscattering of the resulting excited baryons and mesons produced virtually in the first step. No energy loss can take place in the short time interval over which the first cascade takes place. The chief result is a reconciliation of the important Drell-Yan measurements with the apparent success of standard cascades to describe the nucleon stopping and meson production in heavy ion experiments at the CERN SPS.

  2. Ultrarelativistic cascades and strangeness production

    International Nuclear Information System (INIS)

    Kahana, D.E.; Kahana, S.H.

    1998-02-01

    A two phase cascade, LUCIFER II, developed for the treatment of ultra high energy Ion-Ion collisions is applied to the production of strangeness at SPS energies. This simulation is able to simultaneously describe both hard processes such as Drell-Yan and slower, soft processes such as the production of light mesons by separating the dynamics into two steps, a fast cascade involving only the nucleons in the original colliding relativistic ions followed, after an appropriate delay, by a normal multiscattering of the resulting excited baryons and mesons produced virtually in the first step. No energy loss can take place in the short time interval over which the first cascade takes place. The chief result is a reconciliation of the important Drell-Yan measurements with the apparent success of standard cascades to describe the nucleon stopping and meson production in heavy ion experiments at the CERN SPS

  3. Computation of inverse magnetic cascades

    International Nuclear Information System (INIS)

    Montgomery, D.

    1981-10-01

    Inverse cascades of magnetic quantities for turbulent incompressible magnetohydrodynamics are reviewed, for two and three dimensions. The theory is extended to the Strauss equations, a description intermediate between two and three dimensions appropriate to tokamak magnetofluids. Consideration of the absolute equilibrium Gibbs ensemble for the system leads to a prediction of an inverse cascade of magnetic helicity, which may manifest itself as a major disruption. An agenda for computational investigation of this conjecture is proposed

  4. Stochastic background of atmospheric cascades

    International Nuclear Information System (INIS)

    Wilk, G.; Wlodarczyk, Z.

    1993-01-01

    Fluctuations in the atmospheric cascades developing during the propagation of very high energy cosmic rays through the atmosphere are investigated using stochastic branching model of pure birth process with immigration. In particular, we show that the multiplicity distributions of secondaries emerging from gamma families are much narrower than those resulting from hadronic families. We argue that the strong intermittent like behaviour found recently in atmospheric families results from the fluctuations in the cascades themselves and are insensitive to the details of elementary interactions

  5. Correlation Structure of Wavelet Cascades

    Science.gov (United States)

    Greiner, Martin; Giesemann, Jens

    The following sections are included: * Introduction * Some Basics about Wavelets * Multiresolution analysis * Dilation equations * Wavelet transformation * Multiplicative Haar-Wavelet Cascade * Binary random multiplicative branching processes * n-point correlation densities * Haar-wavelet transformed correlation densities * Daubechies-wavelet transformed correlation densities * Multiplicative Daubechies-Wavelet Cascade * Random multiplicative branching processes on a D4-wavelet tree * n-point correlation densities * Wavelet transformed correlation densities * Scaling behavior of moments * Conclusion * REFERENCES

  6. Interband Cascade Photovoltaic Cells

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Rui Q. [Univ. of Oklahoma, Norman, OK (United States); Santos, Michael B. [Univ. of Oklahoma, Norman, OK (United States); Johnson, Matthew B. [Univ. of Oklahoma, Norman, OK (United States)

    2014-09-24

    In this project, we are performing basic and applied research to systematically investigate our newly proposed interband cascade (IC) photovoltaic (PV) cells [1]. These cells follow from the great success of infrared IC lasers [2-3] that pioneered the use of quantum-engineered IC structures. This quantum-engineered approach will enable PV cells to efficiently convert infrared radiation from the sun or other heat source, to electricity. Such cells will have important applications for more efficient use of solar energy, waste-heat recovery, and power beaming in combination with mid-infrared lasers. The objectives of our investigations are to: achieve extensive understanding of the fundamental aspects of the proposed PV structures, develop the necessary knowledge for making such IC PV cells, and demonstrate prototype working PV cells. This research will focus on IC PV structures and their segments for utilizing infrared radiation with wavelengths from 2 to 5 μm, a range well suited for emission by heat sources (1,000-2,000 K) that are widely available from combustion systems. The long-term goal of this project is to push PV technology to longer wavelengths, allowing for relatively low-temperature thermal sources. Our investigations address material quality, electrical and optical properties, and their interplay for the different regions of an IC PV structure. The tasks involve: design, modeling and optimization of IC PV structures, molecular beam epitaxial growth of PV structures and relevant segments, material characterization, prototype device fabrication and testing. At the end of this program, we expect to generate new cutting-edge knowledge in the design and understanding of quantum-engineered semiconductor structures, and demonstrate the concepts for IC PV devices with high conversion efficiencies.

  7. Time structure of cascade showers

    International Nuclear Information System (INIS)

    Nakatsuka, Takao

    1984-01-01

    Interesting results have been reported on the time structure of the electromagnetic components of air showers which have been obtained by using recent fast electronic circuit technology. However, these analyses and explanations seem not very persuasive. One of the reasons is that there is not satisfactory theoretical calculation yet to explain the delay of electromagnetic components in cascade processes which are the object of direct observation. Therefore, Monte Carlo calculation was attempted for examining the relationship between the altitude at which high energy γ-ray is generated up in the air and the time structure of cascade showers at the level of observation. The investigation of a dominant factor over the delay of electromagnetic components indicated that the delay due to the multiple scattering of electrons was essential. The author used the analytical solution found by himself of C. N. Yang's equation for the study on the delay due to multiple scattering. The results were as follows: The average delay time and the spread of distribution of electromagnetic cascades were approximately in linear relationship with the mass of a material having passed in a thin uniform medium; the rise time of arrival time distribution for electromagnetic cascade showers was very steep under the condition that they were generated up in the air and observed on the ground; the subpeaks delayed by tens of ns in arrival time may sometimes appear due to the perturbation in electromagnetic cascade processes. (Wakatsuki, Y.)

  8. Contribution to the energy calibration of GLAST-LAT's calorimeter and validation of hadronic cascade models available with GEANT4

    International Nuclear Information System (INIS)

    Bregeon, J.

    2005-09-01

    GLAST is the new generation of Gamma-ray telescope and should dramatically improve our knowledge of the gamma-ray sky when it is launched on September 7. 2007. Data from the beam test that was held at GANIL with low energy ions were analyzed in order to measure the light quenching factor of CsI for all kinds of ions from proton to krypton of energy between 0 and 73 MeV per nucleon. These results have been very useful to understand the light quenching for relativistic ions that was measured during the GSI beam test. The knowledge of light quenching in GLAST CsI detectors for high energy ions is required for the on-orbit calibration with cosmic rays to succeed. Hadronic background rejection is another major issue for GLAST, thus, all the algorithms rely on the GLAST official Monte-Carlo simulation, GlastRelease. Hadronic cascade data from the GSI beam test and from another beam test held at CERN on the SPS have been used to benchmark hadronic cascade simulation within the framework of GEANT4, on which GlastRelease is based. Testing the good reproduction of simple parameters in GLAST-like calorimeters for hadronic cascades generated by 1.7 GeV, 3.4 GeV, 10 GeV and 20 GeV protons or pions led us to the conclusion that at high energy the default LHEP model is good enough, whereas at low energy the Bertini intra-nuclear cascade model should be used. (author)

  9. Multiplicity distributions in QCD cascades

    International Nuclear Information System (INIS)

    Gustafson, G.

    1992-03-01

    Multiplicity distributions for hadrons and for jets are studied in QCD parton cascades. The colour dipole formalism is used and earlier results in the double log approximation are generalized to include terms which are suppressed by colour factors or factors of ln s. The result is a set of coupled differential equations, together with appropriate boundary conditions

  10. Azobenzene-functionalized cascade molecules

    DEFF Research Database (Denmark)

    Archut, A.; Vogtle, F.; De Cola, L.

    1998-01-01

    Cascade molecules bearing up to 32 azobenzene groups in the periphery have been prepared from poly(propylene imine) dendrimers and N-hydroxysuccinimide esters. The dendritic azobenzene species show similar isomerization properties as the corresponding azobenzene monomers. The all-E azobenzene...

  11. CASCADE: Introducing AI into CBT.

    Science.gov (United States)

    Hendley, R. J.; Jurascheck, N.

    1992-01-01

    Discusses changes in training requirements of commerce and industry in the United Kingdom and describes a project, CASCADE, that was developed to investigate and implement the introduction of artificial intelligence (AI) techniques into computer-based training (CBT). An overview of pilot projects in higher education settings is provided. (eight…

  12. Cascade Support Vector Machines with Dimensionality Reduction

    Directory of Open Access Journals (Sweden)

    Oliver Kramer

    2015-01-01

    Full Text Available Cascade support vector machines have been introduced as extension of classic support vector machines that allow a fast training on large data sets. In this work, we combine cascade support vector machines with dimensionality reduction based preprocessing. The cascade principle allows fast learning based on the division of the training set into subsets and the union of cascade learning results based on support vectors in each cascade level. The combination with dimensionality reduction as preprocessing results in a significant speedup, often without loss of classifier accuracies, while considering the high-dimensional pendants of the low-dimensional support vectors in each new cascade level. We analyze and compare various instantiations of dimensionality reduction preprocessing and cascade SVMs with principal component analysis, locally linear embedding, and isometric mapping. The experimental analysis on various artificial and real-world benchmark problems includes various cascade specific parameters like intermediate training set sizes and dimensionalities.

  13. Computer simulation of displacement cascades in copper

    International Nuclear Information System (INIS)

    Heinisch, H.L.

    1983-06-01

    More than 500 displacement cascades in copper have been generated with the computer simulation code MARLOWE over an energy range pertinent to both fission and fusion neutron spectra. Three-dimensional graphical depictions of selected cascades, as well as quantitative analysis of cascade shapes and sizes and defect densities, illustrate cascade behavior as a function of energy. With increasing energy, the transition from production of single compact damage regions to widely spaced multiple damage regions is clearly demonstrated

  14. Cascaded Bragg scattering in fiber optics.

    Science.gov (United States)

    Xu, Y Q; Erkintalo, M; Genty, G; Murdoch, S G

    2013-01-15

    We report on a theoretical and experimental study of cascaded Bragg scattering in fiber optics. We show that the usual energy-momentum conservation of Bragg scattering can be considerably relaxed via cascade-induced phase-matching. Experimentally we demonstrate frequency translation over six- and 11-fold cascades, in excellent agreement with derived phase-matching conditions.

  15. Cascade Chaotic System With Applications.

    Science.gov (United States)

    Zhou, Yicong; Hua, Zhongyun; Pun, Chi-Man; Chen, C L Philip

    2015-09-01

    Chaotic maps are widely used in different applications. Motivated by the cascade structure in electronic circuits, this paper introduces a general chaotic framework called the cascade chaotic system (CCS). Using two 1-D chaotic maps as seed maps, CCS is able to generate a huge number of new chaotic maps. Examples and evaluations show the CCS's robustness. Compared with corresponding seed maps, newly generated chaotic maps are more unpredictable and have better chaotic performance, more parameters, and complex chaotic properties. To investigate applications of CCS, we introduce a pseudo-random number generator (PRNG) and a data encryption system using a chaotic map generated by CCS. Simulation and analysis demonstrate that the proposed PRNG has high quality of randomness and that the data encryption system is able to protect different types of data with a high-security level.

  16. Bankruptcy cascades in interbank markets.

    Directory of Open Access Journals (Sweden)

    Gabriele Tedeschi

    Full Text Available We study a credit network and, in particular, an interbank system with an agent-based model. To understand the relationship between business cycles and cascades of bankruptcies, we model a three-sector economy with goods, credit and interbank market. In the interbank market, the participating banks share the risk of bad debits, which may potentially spread a bank's liquidity problems through the network of banks. Our agent-based model sheds light on the correlation between bankruptcy cascades and the endogenous economic cycle of booms and recessions. It also demonstrates the serious trade-off between, on the one hand, reducing risks of individual banks by sharing them and, on the other hand, creating systemic risks through credit-related interlinkages of banks. As a result of our study, the dynamics underlying the meltdown of financial markets in 2008 becomes much better understandable.

  17. Bankruptcy cascades in interbank markets.

    Science.gov (United States)

    Tedeschi, Gabriele; Mazloumian, Amin; Gallegati, Mauro; Helbing, Dirk

    2012-01-01

    We study a credit network and, in particular, an interbank system with an agent-based model. To understand the relationship between business cycles and cascades of bankruptcies, we model a three-sector economy with goods, credit and interbank market. In the interbank market, the participating banks share the risk of bad debits, which may potentially spread a bank's liquidity problems through the network of banks. Our agent-based model sheds light on the correlation between bankruptcy cascades and the endogenous economic cycle of booms and recessions. It also demonstrates the serious trade-off between, on the one hand, reducing risks of individual banks by sharing them and, on the other hand, creating systemic risks through credit-related interlinkages of banks. As a result of our study, the dynamics underlying the meltdown of financial markets in 2008 becomes much better understandable.

  18. Atom-atom collision cascades localization

    International Nuclear Information System (INIS)

    Kirsanov, V.V.

    1980-01-01

    The presence of an impurity and thermal vibration influence on the atom-atom collision cascade development is analysed by the computer simulation method (the modificated dynamic model). It is discovered that the relatively low energetic cascades are localized with the temperature increase of an irradiated crystal. On the basis of the given effect the mechanism of splitting of the high energetic cascades into subcascades is proposed. It accounts for two factors: the primary knocked atom energy and the irradiated crystal temperature. Introduction of an impurity also localizes the cascades independently from the impurity atom mass. The cascades localization leads to intensification of the process of annealing in the cascades and reduction of the post-cascade vacancy cluster sizes. (author)

  19. Abnormal cascading failure spreading on complex networks

    International Nuclear Information System (INIS)

    Wang, Jianwei; Sun, Enhui; Xu, Bo; Li, Peng; Ni, Chengzhang

    2016-01-01

    Applying the mechanism of the preferential selection of the flow destination, we develop a new method to quantify the initial load on an edge, of which the flow is transported along the path with the shortest edge weight between two nodes. Considering the node weight, we propose a cascading model on the edge and investigate cascading dynamics induced by the removal of the edge with the largest load. We perform simulated attacks on four types of constructed networks and two actual networks and observe an interesting and counterintuitive phenomenon of the cascading spreading, i.e., gradually improving the capacity of nodes does not lead to the monotonous increase in the robustness of these networks against cascading failures. The non monotonous behavior of cascading dynamics is well explained by the analysis on a simple graph. We additionally study the effect of the parameter of the node weight on cascading dynamics and evaluate the network robustness by a new metric.

  20. Interband Cascade Laser Photon Noise

    Science.gov (United States)

    2009-09-01

    separated by an injection region composed of digitally graded Indium Arsenide (InAs)/ Aluminum Indium Antimonide (Al(In)Sb) multi-QWs. The active region...consists of coupled InAs, Gallium Indium Antimonide (GaInSb) and Gallium Antimonide (GaSb) QWs separated by Aluminum Antimonide (AlSb) barriers. Under... Antimonide AlInSb Aluminum Indium Antimonide cw constant wave DC direct current GaSb Gallium Antimonide IC Interband cascade InAs Indium Arsenide InSb

  1. Availability Cascades & the Sharing Economy

    DEFF Research Database (Denmark)

    Netter, Sarah

    2014-01-01

    attention. This conceptual paper attempts to explain the emergent focus on the sharing economy and associated business and consumption models by applying cascade theory. Risks associated with this behavior will be especially examined with regard to the sustainability claim of collaborative consumption....... With academics, practitioners, and civil society alike having a shared history in being rather fast in accepting new concepts that will not only provide business opportunities but also a good conscience, this study proposes a critical study of the implications of collaborative consumption, before engaging...

  2. Inverse design technique for cascades

    Science.gov (United States)

    Zannetti, L.; Pandolfi, M.

    1984-01-01

    A numerical technique to generate cascades is presented. The basic prescribed parameters are: inlet angle, exit pressure, and distribution of blade thickness and lift along a blade. Other sets of parameters are also discussed. The technique is based on the lambda scheme. The problem of stability of the computation as a function of the prescribed set of parameters and the treatment of boundary conditions is discussed. A one dimensional analysis to indicate a possible way for assuring stability for any two dimensional calculation is provided.

  3. Disaster Mythology and Availability Cascades

    Directory of Open Access Journals (Sweden)

    Lisa Grow Sun

    2013-04-01

    Full Text Available Sociological research conducted in the aftermath of natural disasters has uncovered a number of “disaster myths” – widely shared misconceptions about typical post-disaster human behavior. This paper discusses the possibility that perpetuation of disaster mythology reflects an “availability cascade,” defined in prior scholarship as a “self-reinforcing process of collective belief formation by which an expressed perception triggers a chain reaction that gives the perception increasing plausibility through its rising availability in public discourse.” (Kuran and Sunstein 1999. Framing the spread of disaster mythology as an availability cascade suggests that certain tools may be useful in halting the myths’ continued perpetuation. These tools include changing the legal and social incentives of so-called “availability entrepreneurs” – those principally responsible for beginning and perpetuating the cascade, as well as insulating decision-makers from political pressures generated by the availability cascade. This paper evaluates the potential effectiveness of these and other solutions for countering disaster mythology. Las investigaciones sociológicas realizadas tras los desastres naturales han hecho evidentes una serie de “mitos del desastre”, conceptos erróneos ampliamente compartidos sobre el comportamiento humano típico tras un desastre. Este artículo analiza la posibilidad de que la perpetuación de los mitos del desastre refleje una “cascada de disponibilidad”, definida en estudios anteriores como un “proceso de auto-refuerzo de la formación de una creencia colectiva, a través del que una percepción expresada produce una reacción en cadena que hace que la percepción sea cada vez más verosímil, a través de una mayor presencia en el discurso público” (Kuran y Sunstein 1999. Enmarcar la propagación de los mitos del desastre como una cascada de disponibilidad sugiere que ciertas herramientas pueden ser

  4. Ion-implantation dense cascade data

    International Nuclear Information System (INIS)

    Winterbon, K.B.

    1983-04-01

    A tabulation is given of data useful in estimating various aspects of ion-implantation cascades in the nuclear stopping regime, particularly with respect to nonlinearity of the cascade at high energy densities. The tabulation is restricted to self-ion implantation. Besides power-cross-section cascade dimensions, various material properties are included. Scaling of derived quantities with input data is noted, so one is not limited to the values assumed by the author

  5. A non-conventional isotope separation cascade without any mixing: net cascade

    International Nuclear Information System (INIS)

    Zeng Shi; Jiang Dongjun; Ying Zhengen

    2012-01-01

    A component has different concentrations in the incoming flows at a confluent point in all existing isotope separations cascades for multi-component isotope separation and mixing is inevitable, which results in deterioration of separation performance of the separation cascade. However, realization of no-mixing at a confluent point is impossible with a conventional cascade. A non-conventional isotope separation cascade, net cascade, is found to be able to realize no mixings for all components at confluent points, and its concept is further developed here. No-mixing is fulfilled by requiring symmetrical separation of two specified key components at every stage, and the procedure of realizing no-mixing is presented in detail. Some properties of net cascade are investigated preliminarily, and the results demonstrated the no-mixing property is indeed realized. Net cascade is the only separation cascade that so far possesses the no-mixing property. (authors)

  6. Effects of deletion and overexpression of the Autographa californica nuclear polyhedrosis virus FP25K gene on synthesis of two occlusion-derived virus envelope proteins and their transport into virus-induced intranuclear membranes.

    Science.gov (United States)

    Rosas-Acosta, G; Braunagel, S C; Summers, M D

    2001-11-01

    Partial deletions within Autographa californica open reading frame 61 (FP25K) alter the expression and accumulation profile of several viral proteins and the transport of occlusion-derived virus (ODV)-E66 to intranuclear membranes during infection (S. C. Braunagel et al., J. Virol. 73:8559-8570, 1999). Here we show the effects of a full deletion and overexpression of FP25K on the transport and expression of two ODV envelope proteins, ODV-E66 (E66) and ODV-E25 (E25). Deletion and overexpression of FP25K substantially altered the levels of expression of E66 during infection. Compared with cells infected with wild-type (wt) virus, the levels of E66 were reduced fivefold in cells infected with a viral mutant lacking FP25K (DeltaFP25K) and were slightly increased in cells infected with a viral mutant overexpressing FP25K (FP25K(polh)). In contrast, no significant changes were observed in the levels of E25 among wt-, DeltaFP25K-, and FP25K(polh)-infected cells. The changes observed in the levels of E66 among the different viral mutants were not accompanied by changes in either the time of synthesis, membrane association, protein turnover, or steady-state transcript abundance. Deletion of FP25K also substantially altered the transport and localization of E66 during infection. In cells infected with the DeltaFP25K mutant virus, E66 accumulated in localized regions at the nuclear periphery and the outer nuclear membrane and did not traffic to intranuclear membranes. In contrast, in cells infected with the FP25K(polh) mutant virus E66 trafficked to intranuclear membranes. For comparison, E25 was normally transported to intranuclear membranes in both DeltaFP25K- and FP25K(polh)-infected cells. Altogether these studies suggest that FP25K affects the synthesis of E66 at a posttranscriptional level, probably by altering the translation of E66; additionally, the block in transport of E66 at the nuclear envelope in DeltaFP25K-infected cells suggests that the pathway of E66

  7. Contingency Analysis of Cascading Line Outage Events

    Energy Technology Data Exchange (ETDEWEB)

    Thomas L Baldwin; Magdy S Tawfik; Miles McQueen

    2011-03-01

    As the US power systems continue to increase in size and complexity, including the growth of smart grids, larger blackouts due to cascading outages become more likely. Grid congestion is often associated with a cascading collapse leading to a major blackout. Such a collapse is characterized by a self-sustaining sequence of line outages followed by a topology breakup of the network. This paper addresses the implementation and testing of a process for N-k contingency analysis and sequential cascading outage simulation in order to identify potential cascading modes. A modeling approach described in this paper offers a unique capability to identify initiating events that may lead to cascading outages. It predicts the development of cascading events by identifying and visualizing potential cascading tiers. The proposed approach was implemented using a 328-bus simplified SERC power system network. The results of the study indicate that initiating events and possible cascading chains may be identified, ranked and visualized. This approach may be used to improve the reliability of a transmission grid and reduce its vulnerability to cascading outages.

  8. Lifespans of Cascade Arc volcanoes

    Science.gov (United States)

    Calvert, A. T.

    2015-12-01

    Compiled argon ages reveal inception, eruptive episodes, ages, and durations of Cascade stratovolcanoes and their ancestral predecessors. Geologic mapping and geochronology show that most Cascade volcanoes grew episodically on multiple scales with periods of elevated behavior lasting hundreds of years to ca. 100 kyr. Notable examples include the paleomag-constrained, few-hundred-year-long building of the entire 15-20 km3 Shastina edifice at Mt. Shasta, the 100 kyr-long episode that produced half of Mt. Rainier's output, and the 30 kyr-long episode responsible for all of South and Middle Sister. Despite significant differences in timing and rates of construction, total durations of active and ancestral volcanoes at discrete central-vent locations are similar. Glacier Peak, Mt. Rainier, Mt. Adams, Mt. Hood, and Mt. Mazama all have inception ages of 400-600 ka. Mt. St. Helens, Mt. Jefferson, Newberry Volcano, Mt. Shasta and Lassen Domefield have more recent inception ages of 200-300 ka. Only the Sisters cluster and Mt. Baker have established eruptive histories spanning less than 50 kyr. Ancestral volcanoes centered 5-20 km from active stratocones appear to have similar total durations (200-600 kyr), but are less well exposed and dated. The underlying mechanisms governing volcano lifecycles are cryptic, presumably involving tectonic and plumbing changes and perhaps circulation cycles in the mantle wedge, but are remarkably consistent along the arc.

  9. A Honey Bee Hexamerin, HEX 70a, Is Likely to Play an Intranuclear Role in Developing and Mature Ovarioles and Testioles

    Science.gov (United States)

    Martins, Juliana R.; Anhezini, Lucas; Dallacqua, Rodrigo P.; Simões, Zilá L. P.; Bitondi, Márcia M. G.

    2011-01-01

    Insect hexamerins have long been known as storage proteins that are massively synthesized by the larval fat body and secreted into hemolymph. Following the larval-to-pupal molt, hexamerins are sequestered by the fat body via receptor-mediated endocytosis, broken up, and used as amino acid resources for metamorphosis. In the honey bee, the transcript and protein subunit of a hexamerin, HEX 70a, were also detected in ovaries and testes. Aiming to identify the subcellular localization of HEX 70a in the female and male gonads, we used a specific antibody in whole mount preparations of ovaries and testes for analysis by confocal laser-scanning microscopy. Intranuclear HEX 70a foci were evidenced in germ and somatic cells of ovarioles and testioles of pharate-adult workers and drones, suggesting a regulatory or structural role. Following injection of the thymidine analog EdU we observed co-labeling with HEX 70a in ovariole cell nuclei, inferring possible HEX 70a involvement in cell proliferation. Further support to this hypothesis came from an injection of anti-HEX 70a into newly ecdysed queen pupae where it had a negative effect on ovariole thickening. HEX 70a foci were also detected in ovarioles of egg laying queens, particularly in the nuclei of the highly polyploid nurse cells and in proliferating follicle cells. Additional roles for this storage protein are indicated by the detection of nuclear HEX 70a foci in post-meiotic spermatids and spermatozoa. Taken together, these results imply undescribed roles for HEX 70a in the developing gonads of the honey bee and raise the possibility that other hexamerins may also have tissue specific functions. PMID:22205988

  10. A honey bee hexamerin, HEX 70a, is likely to play an intranuclear role in developing and mature ovarioles and testioles.

    Directory of Open Access Journals (Sweden)

    Juliana R Martins

    Full Text Available Insect hexamerins have long been known as storage proteins that are massively synthesized by the larval fat body and secreted into hemolymph. Following the larval-to-pupal molt, hexamerins are sequestered by the fat body via receptor-mediated endocytosis, broken up, and used as amino acid resources for metamorphosis. In the honey bee, the transcript and protein subunit of a hexamerin, HEX 70a, were also detected in ovaries and testes. Aiming to identify the subcellular localization of HEX 70a in the female and male gonads, we used a specific antibody in whole mount preparations of ovaries and testes for analysis by confocal laser-scanning microscopy. Intranuclear HEX 70a foci were evidenced in germ and somatic cells of ovarioles and testioles of pharate-adult workers and drones, suggesting a regulatory or structural role. Following injection of the thymidine analog EdU we observed co-labeling with HEX 70a in ovariole cell nuclei, inferring possible HEX 70a involvement in cell proliferation. Further support to this hypothesis came from an injection of anti-HEX 70a into newly ecdysed queen pupae where it had a negative effect on ovariole thickening. HEX 70a foci were also detected in ovarioles of egg laying queens, particularly in the nuclei of the highly polyploid nurse cells and in proliferating follicle cells. Additional roles for this storage protein are indicated by the detection of nuclear HEX 70a foci in post-meiotic spermatids and spermatozoa. Taken together, these results imply undescribed roles for HEX 70a in the developing gonads of the honey bee and raise the possibility that other hexamerins may also have tissue specific functions.

  11. Detection of intranuclear forces by the use of laser optics during the recovery process of elongated interphase nuclei in centrifuged protonemal cells of Adiantum capillus-veneris

    International Nuclear Information System (INIS)

    Wunsch, C.; Kurachi, M.; Kikumoto, M.; Tashiro, H.; Wada, M.

    1998-01-01

    For the direct investigation of intranuclear dynamics in living cells, extremely deformed nuclei of basipetally centrifuged protonemal cells of the fern Adiantum capillusveneris were manipulated by the laser rap and the laser scalpel. Whereas the nucleolus was tightly fixed at the central position inside the non-centrifuged nucleus and proved to be immovable by the optical trap, it could easily be trapped and moved towards three directions inside the bubble-like terminal widening of the basal thread-like extension of centrifuged nuclei. Due to the connection of the nucleolus to the chromatin inside the nuclear thread (NT), moving was not possible against the direction of the nuclear apical main body. Nucleoli in recovered nuclei were again immovable, thus indicating the presence of a dynamic nucleolar anchoring system inside the nucleus. When the nucleolus in the bubble was arrested during the thread shortening process by the optical trap, the acropetal movement of the bubble continued. Probably dye to dragging forces, some nucleoli became stretched, and a thick strand of a still unknown composition stretched between the nucleolus and the insertion site of the shortening NT. To assess whether the shrinking of the nuclear envelop (NE) and the shortening of the chromatin inside the NT were independent processes, the chromatin above the bubble was cut inside the Nt by the laser scalpel. After severance, a gap between the nucleolus and the end of the chromatin strand in the NT indicated the shortening of the chromatin inside the Nt. From these findings it was concluded that a shortening force was existing in the chromatin of the NT and that probably no physical link existed between the chromatin and the NE

  12. Centrifugal separator cascade connected in zigzag manner

    International Nuclear Information System (INIS)

    Kai, Tsunetoshi; Inoue, Yoshiya; Oya, Akio; Nagakura, Masaaki.

    1974-01-01

    Object: To effectively accommodate centrifugal separators of the entire cascade within the available space in a plant by freely selecting perpendicular direction of connection of the centrifugal separator. Structure: Centrifugal separators are connected in zigzag fashion by using a single header for each stage so that in a rectangular shape the entire cascade is arranged. (Kamimura, M.)

  13. Cascade Harvest’ red raspberry

    Science.gov (United States)

    Cascade Harvest’ is a new floricane fruiting raspberry cultivar (Rubus idaeus L.) jointly released by Washington State University (WSU), Oregon State University (OSU) and the U.S. Department of Agriculture (USDA). ‘Cascade Harvest’ produces a high yield of large, firm fruit suited to machine harves...

  14. Availability Cascades & the Sharing Economy

    DEFF Research Database (Denmark)

    Netter, Sarah

    2014-01-01

    In search of a new concept that will provide answers to as to how modern societies should not only make sense but also resolve the social and environmental problems linked with our modes of production and consumption, collaborative consumption and the sharing economy are increasingly attracting...... attention. This conceptual paper attempts to explain the emergent focus on the sharing economy and associated business and consumption models by applying cascade theory. Risks associated with this behavior will be especially examined with regard to the sustainability claim of collaborative consumption....... With academics, practitioners, and civil society alike having a shared history in being rather fast in accepting new concepts that will not only provide business opportunities but also a good conscience, this study proposes a critical study of the implications of collaborative consumption, before engaging...

  15. Cascade Error Projection: An Efficient Hardware Learning Algorithm

    Science.gov (United States)

    Duong, T. A.

    1995-01-01

    A new learning algorithm termed cascade error projection (CEP) is presented. CEP is an adaption of a constructive architecture from cascade correlation and the dynamical stepsize of A/D conversion from the cascade back propagation algorithm.

  16. Experimental study of flow through compressor Cascade

    Directory of Open Access Journals (Sweden)

    Satyam Panchal

    2017-09-01

    Full Text Available The objective of this research work is to study the behaviour of flow at the inlet, within the blade passage and at the exit of a compressor cascade. For this purpose, a cascade with six numbers of aerofoil blades was designed and constructed. The cascade was fitted on the cascade test tunnel. Out of six blades two were instrumented for measuring the pressure distribution on the pressure and suction surface. The blades had a parabolic camber line, with a maximum camber position at 40% of the chord from the leading edge of the blade. The profile of the blade was C4, height of the blade was 160 mm, chord length was 80 mm, camber angle was 45° and stagger angle was 30°. Similarly, the length of the cascade was 300 mm, span was 160 mm, pitch was 60 mm, the actual chord of the cascade was 80 mm, the axial chord of the cascade was 70 mm, the stagger angle of the cascade was 30° and the pitch-chord ratio was 0.75. The data was taken and analyzed at −500% of the axial chord before the cascade, −25% of the axial chord before the leading edge, 25%, 50%, 75% and 150% of the axial chord from the leading edge of the blade. The readings were taken from the cascade wall to the mid span position along the pitch wise direction. The angle of incidence was also changed during the experiment and varied from i=−50°, −30°, −10° to 5°.

  17. Collision cascades in Zr3Fe

    International Nuclear Information System (INIS)

    Howe, L.M.; Rainville, M.H.; Phillips, D.; Plattner, H.H.; Bonnett, J.D.

    1994-11-01

    The objective of the present research is to understand better the processes that control irradiation-induced phase changes and solute segregation in zirconium alloys. Previously, it was found that 0.5 - 1.5 MeV 40 Ar ion irradiations resulted in the conversion of the crystalline Zr 3 Fe orthorhombic phase to the amorphous state. In the present investigation, 15 - 1500 keV 209 Bi ion irradiations (10 11 - 10 14 ions cm -2 ) were performed to provide more detailed information on collision cascades in Zr 3 Fe. Consecutive ion bombardments with 1.5, 1.0 and 0.5 MeV 209 Bi ions showed that complete amorphization occurred from 35 K to at least 600 K. Low fluence (10 11 - 101 12 ions cm -2 ) irradiations performed at 35 - 40 K with 15 - 350 keV 209 Bi ions provided information on the nature of the damage produced within individual damage cascades. At high values for the average deposited-energy density θυ in the cascade, which correspond to low-energy heavy-ion implants (e.g., 15-30 keV in Zr 3 Fe), the visible damage produced in a cascade consisted of single damaged region. With decreasing values of θυ (i.e., increasing ion implant energies), there was an increasing tendency for multiple damaged regions (subcascades) to form within a main cascade. The visible damaged regions appeared to be amorphous. It was also found that as the Bi ion energy increased (θυ decreased), the fraction of the theoretical collision-cascade volume that was occupied by the visible damage regions within a cascade decreased rapidly. The crystalline-to-amorphous transformation appeared to be the result of direct amorphization within the collision cascades and a critical defect concentration being reached in the cascade overlap regions, thus producing additional amorphous regions. (author). 30 refs., 2 tabs., 3 figs

  18. Cascade Baryon Spectrum from Lattice QCD

    International Nuclear Information System (INIS)

    Mathur, Nilmani; Bulava, John; Edwards, Robert; Engelson, Eric; Joo, Balint; Lichtl, Adam; Lin, Huey-Wen; Morningstar, Colin; Richards, David; Wallace, Stephen

    2008-01-01

    A comprehensive study of the cascade baryon spectrum using lattice QCD affords the prospect of predicting the masses of states not yet discovered experimentally, and determining the spin and parity of those states for which the quantum numbers are not yet known. The study of the cascades, containing two strange quarks, is particularly attractive for lattice QCD in that the chiral effects are reduced compared to states composed only of u/d quarks, and the states are typically narrow. We report preliminary results for the cascade spectrum obtained by using anisotropic Nf = 2 Wilson lattices with temporal lattice spacing 5.56 GeV?1.

  19. Aspects of the QCD cascade

    International Nuclear Information System (INIS)

    Olsson, Magnus.

    1993-02-01

    A model is proposed for the production of transverse jets from diffractively excited protons. We propose that transverse jets can be obtained from gluonic bremsstrahlung in a way similar to the emission in DIS. Qualitative agreement is obtained between the model and the uncorrected data published by the UA8 collaboration. Perturbative QCD in the MLLA approximation is applied to multiple jet production in e + e - -annihilation. We propose modified evolution equations for deriving the jet cross sections, defined in the 'k t ' or 'Durham' algorithm. The mean number of jets as a function of the jet resolution is studied, and analytical predictions are compared to the results of MC simulations. We also study a set of differential-difference equations for multiplicity distributions in e + e - -annihilations, supplemented with appropriate boundary conditions. These equations take into account nonsingular terms in the GLAP splitting functions as well as kinematical constraints related to recoil effects. The presence of retarded terms imply that the cascade develops more slowly and reduces the fluctuations. The solutions agree well with MC simulations and experimental data. (authors)

  20. Cascade theory in isotopic separation processes

    International Nuclear Information System (INIS)

    Agostini, J.P.

    1994-06-01

    Three main areas are developed within the scope of this work: - the first one is devoted to fundamentals: separative power, value function, ideal cascade and square cascade. Applications to two main cases are carried out, namely: Study of binary isotopic mix, Study of processes with a small enrichment coefficient. - The second one is devoted to cascade coupling -high-flux coupling (more widely used and better known) as well as low-flux coupling are presented and compared to one another. - The third one is an outlook on problems linked to cascade transients. Those problem are somewhat intricate and their interest lies mainly into two areas: economics where the start-up time may have a large influence on the interests paid during the construction and start-up period, military productions where the start-up time has a direct bearing on the production schedule. (author). 50 figs. 3 annexes. 12 refs. 6 tabs

  1. MAP kinase cascades in Arabidopsis innate immunity

    DEFF Research Database (Denmark)

    Rasmussen, Magnus Wohlfahrt; Roux, Milena Edna; Petersen, Morten

    2012-01-01

    Plant mitogen-activated protein kinase (MAPK) cascades generally transduce extracellular stimuli into cellular responses. These stimuli include the perception of pathogen-associated molecular patterns (PAMPs) by host transmembrane pattern recognition receptors which trigger MAPK-dependent innate ...

  2. {tau} polarization in SUSY cascade decays

    Energy Technology Data Exchange (ETDEWEB)

    Choi, S.Y. [Chonbuk Univ., Jeonju (Korea), Dept. of Physics and RIPC]|[Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Hagiwara, K. [KEK National High Energy Physics, Tsukuba (Japan); Kim, Y.G. [Sejong Univ., Seoul (Korea). ARCSEC; Mawatari, K. [Korea Institute for Advanced Study, Seoul (Korea). School of Physics; Zerwas, P.M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)]|[KEK National High Energy Physics, Tsukuba (Japan)

    2006-12-15

    {tau} leptons emitted in cascade decays of supersymmetric particles are polarized. The polarization may be exploited to determine spin and mixing properties of the neutralinos and stau particles involved. (orig.)

  3. Cascade Error Projection: A New Learning Algorithm

    Science.gov (United States)

    Duong, T. A.; Stubberud, A. R.; Daud, T.; Thakoor, A. P.

    1995-01-01

    A new neural network architecture and a hardware implementable learning algorithm is proposed. The algorithm, called cascade error projection (CEP), handles lack of precision and circuit noise better than existing algorithms.

  4. High energy evolution of soft gluon cascades

    International Nuclear Information System (INIS)

    Shuvaev, A.; Wallon, S.

    2006-01-01

    In this paper we derive an evolution equation for the gluon density in soft gluon cascades emitted from any colored source, in the leading logarithmic approximation of perturbative QCD. We show that this equation has the same form as the BFKL equation in the forward case. An explicit expression for the total cascade wavefunction involving an arbitrary number of soft gluons is obtained. Renormalization of the colored source wavefunction turns out to be responsible for the reggeization of the source. (orig.)

  5. High energy evolution of soft gluon cascades

    Energy Technology Data Exchange (ETDEWEB)

    Shuvaev, A. [St. Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg district (Russian Federation); Wallon, S. [Universite Paris XI, Laboratoire de Physique Theorique, Orsay Cedex (France)

    2006-04-15

    In this paper we derive an evolution equation for the gluon density in soft gluon cascades emitted from any colored source, in the leading logarithmic approximation of perturbative QCD. We show that this equation has the same form as the BFKL equation in the forward case. An explicit expression for the total cascade wavefunction involving an arbitrary number of soft gluons is obtained. Renormalization of the colored source wavefunction turns out to be responsible for the reggeization of the source. (orig.)

  6. Compression limits in cascaded quadratic soliton compression

    DEFF Research Database (Denmark)

    Bache, Morten; Bang, Ole; Krolikowski, Wieslaw

    2008-01-01

    Cascaded quadratic soliton compressors generate under optimal conditions few-cycle pulses. Using theory and numerical simulations in a nonlinear crystal suitable for high-energy pulse compression, we address the limits to the compression quality and efficiency.......Cascaded quadratic soliton compressors generate under optimal conditions few-cycle pulses. Using theory and numerical simulations in a nonlinear crystal suitable for high-energy pulse compression, we address the limits to the compression quality and efficiency....

  7. Cascade of links in complex networks

    International Nuclear Information System (INIS)

    Feng, Yeqian; Sun, Bihui; Zeng, An

    2017-01-01

    Cascading failure is an important process which has been widely used to model catastrophic events such as blackouts and financial crisis in real systems. However, so far most of the studies in the literature focus on the cascading process on nodes, leaving the possibility of link cascade overlooked. In many real cases, the catastrophic events are actually formed by the successive disappearance of links. Examples exist in the financial systems where the firms and banks (i.e. nodes) still exist but many financial trades (i.e. links) are gone during the crisis, and the air transportation systems where the airports (i.e. nodes) are still functional but many airlines (i.e. links) stop operating during bad weather. In this letter, we develop a link cascade model in complex networks. With this model, we find that both artificial and real networks tend to collapse even if a few links are initially attacked. However, the link cascading process can be effectively terminated by setting a few strong nodes in the network which do not respond to any link reduction. Finally, a simulated annealing algorithm is used to optimize the location of these strong nodes, which significantly improves the robustness of the networks against the link cascade. - Highlights: • We propose a link cascade model in complex networks. • Both artificial and real networks tend to collapse even if a few links are initially attacked. • The link cascading process can be effectively terminated by setting a few strong nodes. • A simulated annealing algorithm is used to optimize the location of these strong nodes.

  8. Cascade of links in complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Yeqian; Sun, Bihui [Department of Management Science, School of Government, Beijing Normal University, 100875 Beijing (China); Zeng, An, E-mail: anzeng@bnu.edu.cn [School of Systems Science, Beijing Normal University, 100875 Beijing (China)

    2017-01-30

    Cascading failure is an important process which has been widely used to model catastrophic events such as blackouts and financial crisis in real systems. However, so far most of the studies in the literature focus on the cascading process on nodes, leaving the possibility of link cascade overlooked. In many real cases, the catastrophic events are actually formed by the successive disappearance of links. Examples exist in the financial systems where the firms and banks (i.e. nodes) still exist but many financial trades (i.e. links) are gone during the crisis, and the air transportation systems where the airports (i.e. nodes) are still functional but many airlines (i.e. links) stop operating during bad weather. In this letter, we develop a link cascade model in complex networks. With this model, we find that both artificial and real networks tend to collapse even if a few links are initially attacked. However, the link cascading process can be effectively terminated by setting a few strong nodes in the network which do not respond to any link reduction. Finally, a simulated annealing algorithm is used to optimize the location of these strong nodes, which significantly improves the robustness of the networks against the link cascade. - Highlights: • We propose a link cascade model in complex networks. • Both artificial and real networks tend to collapse even if a few links are initially attacked. • The link cascading process can be effectively terminated by setting a few strong nodes. • A simulated annealing algorithm is used to optimize the location of these strong nodes.

  9. Defect production in simulated cascades: cascade quenching and short-term annealing

    International Nuclear Information System (INIS)

    Heinisch, H.L.

    1982-01-01

    Defect production in high energy displacement cascades has been modeled using the computer code MARLOWE to generate the cascades and the stochastic computer code ALSOME to simulate the cascade quenching and short-term annealing of isolated cascades. The quenching is accomplished by using ALSOME with exaggerated values for defect mobilities and critical reaction distanes for recombination and clustering, which are in effect until the number of defect pairs is equal to the value determined from resistivity experiments at 4K. Then normal mobilities and reaction distances are used during short-term annealing to a point representative of Stage III recovery. Effects of cascade interactions at low fluences are also being investigated. The quenching parameter values were empirically determined for 30 keV cascades. The results agree well with experimental information throughout the range from 1 keV to 100 keV. Even after quenching and short-term annealing the high energy cascades behave as a collection of lower energy subcascades and lobes. Cascades generated in a crystal having thermal displacements were found to be in better agreement with experiments after quenching and annealing than those generated in a non-thermal crystal

  10. MAP Kinase Cascades in Plant Innate Immunity

    Directory of Open Access Journals (Sweden)

    Magnus Wohlfahrt Rasmussen

    2012-07-01

    Full Text Available Plant mitogen-activated protein kinase (MAPK cascades generally transduce extracellular stimuli into cellular responses. These stimuli include the perception of pathogen-associated molecular patterns (PAMPs by host transmembrane pattern recognition receptors (PRRs which trigger MAPK-dependent innate immune responses. In the model Arabidopsis, molecular genetic evidence implicates a number of MAPK cascade components in PAMP signaling, and in responses to immunity-related phytohormones such as ethylene, jasmonate and salicylate. In a few cases, cascade components have been directly linked to the transcription of target genes or to the regulation of phytohormone synthesis. Thus MAPKs are obvious targets for bacterial effector proteins and are likely guardees of resistance (R proteins, which mediate defense signaling in response to the action of effectors, or effector-triggered immunity (ETI. This mini-review discusses recent progress in this field with a focus on the Arabidopsis MAPKs MPK3, 4, 6 and 11 in their apparent pathways.

  11. Epidemic and Cascading Survivability of Complex Networks

    DEFF Research Database (Denmark)

    Manzano, Marc; Calle, Eusebi; Ripoll, Jordi

    2014-01-01

    Our society nowadays is governed by complex networks, examples being the power grids, telecommunication networks, biological networks, and social networks. It has become of paramount importance to understand and characterize the dynamic events (e.g. failures) that might happen in these complex...... networks. For this reason, in this paper, we propose two measures to evaluate the vulnerability of complex networks in two different dynamic multiple failure scenarios: epidemic-like and cascading failures. Firstly, we present epidemic survivability ( ES ), a new network measure that describes...... the vulnerability of each node of a network under a specific epidemic intensity. Secondly, we propose cascading survivability ( CS ), which characterizes how potentially injurious a node is according to a cascading failure scenario. Then, we show that by using the distribution of values obtained from ES and CS...

  12. Non-spill control squared cascade

    International Nuclear Information System (INIS)

    Kai, Tsunetoshi; Inoue, Yoshiya; Oya, Akio; Suemori, Nobuo.

    1974-01-01

    Object: To reduce a mixed loss thus enhancing separating efficiency by the provision of a simple arrangement wherein a reflux portion in a conventional spill control squared cascade is replaced by a special stage including centrifugal separators. Structure: Steps in the form of a square cascade, in which a plurality of centrifugal separators are connected by pipe lines, are accumulated in multistage fashion to form a squared cascade. Between the adjoining steps is disposed a special stage including a centrifugal separator which receives both lean flow from the upper step and rich flow from the lower step. The centrifugal separator in the special stage has its rich side connected to the upper step and its lean side connected to the lower step. Special stages are each disposed at the upper side of the uppermost step and at the lower side of the lowermost step. (Kamimura, M.)

  13. Cascade enzymatic reactions for efficient carbon sequestration.

    Science.gov (United States)

    Xia, Shunxiang; Zhao, Xueyan; Frigo-Vaz, Benjamin; Zheng, Wenyun; Kim, Jungbae; Wang, Ping

    2015-04-01

    Thermochemical processes developed for carbon capture and storage (CCS) offer high carbon capture capacities, but are generally hampered by low energy efficiency. Reversible cascade enzyme reactions are examined in this work for energy-efficient carbon sequestration. By integrating the reactions of two key enzymes of RTCA cycle, isocitrate dehydrogenase and aconitase, we demonstrate that intensified carbon capture can be realized through such cascade enzymatic reactions. Experiments show that enhanced thermodynamic driving force for carbon conversion can be attained via pH control under ambient conditions, and that the cascade reactions have the potential to capture 0.5 mol carbon at pH 6 for each mole of substrate applied. Overall it manifests that the carbon capture capacity of biocatalytic reactions, in addition to be energy efficient, can also be ultimately intensified to approach those realized with chemical absorbents such as MEA. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Piscivores, Trophic Cascades, and Lake Management

    Directory of Open Access Journals (Sweden)

    Ray W. Drenner

    2002-01-01

    Full Text Available The concept of cascading trophic interactions predicts that an increase in piscivore biomass in lakes will result in decreased planktivorous fish biomass, increased herbivorous zooplankton biomass, and decreased phytoplankton biomass. Though often accepted as a paradigm in the ecological literature and adopted by lake managers as a basis for lake management strategies, the trophic cascading interactions hypothesis has not received the unequivocal support (in the form of rigorous experimental testing that might be expected of a paradigm. Here we review field experiments and surveys, testing the hypothesis that effects of increasing piscivore biomass will cascade down through the food web yielding a decline in phytoplankton biomass. We found 39 studies in the scientific literature examining piscivore effects on phytoplankton biomass. Of the studies, 22 were confounded by supplemental manipulations (e.g., simultaneous reduction of nutrients or removal of planktivores and could not be used to assess piscivore effects. Of the 17 nonconfounded studies, most did not find piscivore effects on phytoplankton biomass and therefore did not support the trophic cascading interactions hypothesis. However, the trophic cascading interactions hypothesis also predicts that lake systems containing piscivores will have lower phytoplankton biomass for any given phosphorus concentration. Based on regression analyses of chlorophyll�total phosphorus relationships in the 17 nonconfounded piscivore studies, this aspect of the trophic cascading interactions hypothesis was supported. The slope of the chlorophyll vs. total phosphorus regression was lower in lakes with planktivores and piscivores compared with lakes containing only planktivores but no piscivores. We hypothesize that this slope can be used as an indicator of “functional piscivory” and that communities with extremes of functional piscivory (zero and very high represent classical 3- and 4-trophic level

  15. Volcano geodesy in the Cascade arc, USA

    Science.gov (United States)

    Poland, Michael; Lisowski, Michael; Dzurisin, Daniel; Kramer, Rebecca; McLay, Megan; Pauk, Benjamin

    2017-01-01

    Experience during historical time throughout the Cascade arc and the lack of deep-seated deformation prior to the two most recent eruptions of Mount St. Helens might lead one to infer that Cascade volcanoes are generally quiescent and, specifically, show no signs of geodetic change until they are about to erupt. Several decades of geodetic data, however, tell a different story. Ground- and space-based deformation studies have identified surface displacements at five of the 13 major Cascade arc volcanoes that lie in the USA (Mount Baker, Mount St. Helens, South Sister, Medicine Lake, and Lassen volcanic center). No deformation has been detected at five volcanoes (Mount Rainier, Mount Hood, Newberry Volcano, Crater Lake, and Mount Shasta), and there are not sufficient data at the remaining three (Glacier Peak, Mount Adams, and Mount Jefferson) for a rigorous assessment. In addition, gravity change has been measured at two of the three locations where surveys have been repeated (Mount St. Helens and Mount Baker show changes, while South Sister does not). Broad deformation patterns associated with heavily forested and ice-clad Cascade volcanoes are generally characterized by low displacement rates, in the range of millimeters to a few centimeters per year, and are overprinted by larger tectonic motions of several centimeters per year. Continuous GPS is therefore the best means of tracking temporal changes in deformation of Cascade volcanoes and also for characterizing tectonic signals so that they may be distinguished from volcanic sources. Better spatial resolution of volcano deformation can be obtained through the use of campaign GPS, semipermanent GPS, and interferometric synthetic aperture radar observations, which leverage the accumulation of displacements over time to improve signal to noise. Deformation source mechanisms in the Cascades are diverse and include magma accumulation and withdrawal, post-emplacement cooling of recent volcanic deposits, magmatic

  16. Dynamics of soliton cascades in fiber amplifiers.

    Science.gov (United States)

    Arteaga-Sierra, F R; Antikainen, A; Agrawal, Govind P

    2016-11-15

    We study numerically the formation of cascading solitons when femtosecond optical pulses are launched into a fiber amplifier with less energy than required to form a soliton of equal duration. As the pulse is amplified, cascaded fundamental solitons are created at different distances, without soliton fission, as each fundamental soliton moves outside the gain bandwidth through the Raman-induced spectral shifts. As a result, each input pulse creates multiple, temporally separated, ultrashort pulses of different wavelengths at the amplifier output. The number of pulses depends not only on the total gain of the amplifier but also on the width of the input pulse.

  17. Cascade Processes in Muonic Hydrogen Atoms

    International Nuclear Information System (INIS)

    Faifman, M. P.; Men'Shikov, L. I.

    2001-01-01

    The QCMC scheme created earlier for cascade calculations in heavy hadronic atoms of hydrogen isotopes has been modified and applied to the study of cascade processes in the μp muonic hydrogen atoms. The distribution of μp atoms over kinetic energies has been obtained and the yields of K-series X-rays per one stopped muon have been calculated.Comparison with experimental data indicated directly that for muonic and pionic atoms new types of non-radiative transitions are essential, while they are negligible for heavy (kaonic, antiprotonic, etc.) atoms. These processes have been considered and their probabilities have been estimated.

  18. EDITORIAL A CASCADE OF BIOCHEMICAL AND PHYSIOLOGICAL ...

    African Journals Online (AJOL)

    pharm-chem

    A CASCADE OF BIOCHEMICAL AND PHYSIOLOGICAL MARKERS IN PATHOLOGICAL. DISORDERS. A few years ago, a neurophysiology lecturer in the Department of Medical Physiology, University of. Nairobi, was doing ... from haemolysis of RBC is rapidly distributed into cells and excreted in kidney. It would have been.

  19. Cascading effects of overfishing marine systems

    NARCIS (Netherlands)

    Scheffer, M.; Carpenter, S.; Young, de B.

    2005-01-01

    Profound indirect ecosystem effects of overfishing have been shown for coastal systems such as coral reefs and kelp forests. A new study from the ecosystem off the Canadian east coast now reveals that the elimination of large predatory fish can also cause marked cascading effects on the pelagic food

  20. Dynamics of cascade processes of muonic atoms

    International Nuclear Information System (INIS)

    Kalantari, Z.; Pirahmadian, M. H.; Ebrahimi, A.

    2006-01-01

    Studies on exotic atoms are important in different ways. They are important for strong interaction with nucleus and the theory of QCD in low energies. They are also important in muon catalyzed fusion. Their properties can be revealed by studies on cascade of muonic atoms. In this paper, unlike the others, we do not consider the kinetic energy of muonic atoms, constant (the kinetic energy of muonic atoms can vary due to cascade processes). We have used multi group method. The energy dependence of the rates of collisional cascade processes can take into account by this method. In addition, the energy spectra of muonic atoms in the ground state are calculated. For this purpose we divided the energy spectrum to 10 groups, and then use the rate of external Auger effect, Coulomb de-excitation, muon transfer and elastic scattering to solve the dynamics of cascade processes in each group. These equations are coupled linear differential equations. To solve them we use the Runge-Kutta method in the fourth order. One of the conclusions of this paper is that, this energy spectrum is not Maxwellian distribution. Finally our results are compared with the results of the Monte-Carlo simulation.

  1. Geothermal research, Oregon Cascades: Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Priest, G.R.; Black, G.L.

    1988-10-27

    Previous USDOE-funded geothermal studies have produced an extensive temperature gradient and heat flow data base for the State of Oregon. One of the important features identified as a result of these studies is a rapid transition from heat flow values on the order of 40 mW/m/sup 2/ in the Willamette Valley and Western Cascades to values of greater than or equal to100 mW/m/sup 2/ in the High Cascades and the eastern portion of the Western Cascades. These data indicate that the Cascade Range in Oregon has potential as a major geothermal province and stimulated much of the later work completed by government agencies and private industry. Additional data generated as a result of this grant and published in DOGAMI Open-File Report 0-86-2 further define the location and magnitude of this transition zone. In addition, abundant data collected from the vicinity of Breitenbush and Austin Hot Springs have permitted the formulation of relatively detailed models of these hydrothermal systems. These models are published in DOGAMI Open-File Report 0-88-5. Task 1.2 of the Deliverables section of Amendment M001 is fulfilled by DOGAMI publication GMS-48, Geologic map of the McKenzie Bridge quadrangle, Lane County, Oregon. This map was printed in October, 1988, and is part of the final submission to USDOE. 8 refs.

  2. Gene regulation by MAP kinase cascades

    DEFF Research Database (Denmark)

    Fiil, Berthe Katrine; Petersen, Klaus; Petersen, Morten

    2009-01-01

    Mitogen-activated protein kinase (MAPK) cascades are signaling modules that transduce extracellular stimuli to a range of cellular responses. Research in yeast and metazoans has shown that MAPK-mediated phosphorylation directly or indirectly regulates the activity of transcription factors. Plant ...

  3. MID-INFRARED QUANTUM CASCADE LASERS

    African Journals Online (AJOL)

    2012-11-03

    Nov 3, 2012 ... Abstract. Quantum cascade lasers (QCL) based on intersubband transitions operating at room temperature in the mid-infrared or 'molecular fingerprint' spectral region (3.4–17 im) have been found useful for several applications including environmental sensing, pollution monitoring, and medical appli-.

  4. Population analysis for atomic cascade decay processes

    International Nuclear Information System (INIS)

    Suto, Keiko; Kagawa, Takashi; Futaba, Kaoru

    1998-01-01

    Down-stream cascade decay processes in atomic systems are analyzed by solving a coupled rate equation for which an analytical solution for a population in each excited state is obtained. Some typical numerical examples for populations to interpret the decay passes connecting to features of optical or electron spectra observed in various collision experiments are also given. (author)

  5. Quantum-engineered interband cascade photovoltaic devices

    Energy Technology Data Exchange (ETDEWEB)

    Razeghi, Manijeh; Tournié, Eric; Brown, Gail J.; Yang, Rui Q.; Lotfi, Hossein; Li, Lu; Hinkey, Robert T.; Ye, Hao; Klem, John F.; Lei, L.; Mishima, T. D.; Keay, J. C.; Santos, M. B.; Johnson, M. B.

    2013-12-18

    Quantum-engineered multiple stage photovoltaic (PV) devices are explored based on InAs/GaSb/AlSb interband cascade (IC) structures. These ICPV devices employ multiple discrete absorbers that are connected in series by widebandgap unipolar barriers using type-II heterostructure interfaces for facilitating carrier transport between cascade stages similar to IC lasers. The discrete architecture is beneficial for improving the collection efficiency and for spectral splitting by utilizing absorbers with different bandgaps. As such, the photo-voltages from each individual cascade stage in an ICPV device add together, creating a high overall open-circuit voltage, similar to conventional multi-junction tandem solar cells. Furthermore, photo-generated carriers can be collected with nearly 100% efficiency in each stage. This is because the carriers travel over only a single cascade stage, designed to be shorter than a typical diffusion length. The approach is of significant importance for operation at high temperatures where the diffusion length is reduced. Here, we will present our recent progress in the study of ICPV devices, which includes the demonstration of ICPV devices at room temperature and above with narrow bandgaps (e.g. 0.23 eV) and high open-circuit voltages. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  6. Cascade theory in isotopic separation processes; Theorie des cascades en separation isotopique

    Energy Technology Data Exchange (ETDEWEB)

    Agostini, J.P.

    1994-06-01

    Three main areas are developed within the scope of this work: - the first one is devoted to fundamentals: separative power, value function, ideal cascade and square cascade. Applications to two main cases are carried out, namely: Study of binary isotopic mix, Study of processes with a small enrichment coefficient. - The second one is devoted to cascade coupling -high-flux coupling (more widely used and better known) as well as low-flux coupling are presented and compared to one another. - The third one is an outlook on problems linked to cascade transients. Those problem are somewhat intricate and their interest lies mainly into two areas: economics where the start-up time may have a large influence on the interests paid during the construction and start-up period, military productions where the start-up time has a direct bearing on the production schedule. (author). 50 figs. 3 annexes. 12 refs. 6 tabs.

  7. Cascading Generative Adversarial Networks for Targeted

    KAUST Repository

    Hamdi, Abdullah

    2018-04-09

    Abundance of labelled data played a crucial role in the recent developments in computer vision, but that faces problems like scalability and transferability to the wild. One alternative approach is to utilize the data without labels, i.e. unsupervised learning, in learning valuable information and put it in use to tackle vision problems. Generative Adversarial Networks (GANs) have gained momentum for their ability to model image distributions in unsupervised manner. They learn to emulate the training set and that enables sampling from that domain and using the knowledge learned for useful applications. Several methods proposed enhancing GANs, including regularizing the loss with some feature matching. We seek to push GANs beyond the data in the training and try to explore unseen territory in the image manifold. We first propose a new regularizer for GAN based on K-Nearest Neighbor (K-NN) selective feature matching to a target set Y in high-level feature space, during the adversarial training of GAN on the base set X, and we call this novel model K-GAN. We show that minimizing the added term follows from cross-entropy minimization between the distributions of GAN and set Y. Then, we introduce a cascaded framework for GANs that try to address the task of imagining a new distribution that combines the base set X and target set Y by cascading sampling GANs with translation GANs, and we dub the cascade of such GANs as the Imaginative Adversarial Network (IAN). Several cascades are trained on a collected dataset Zoo-Faces and generated innovative samples are shown, including from K-GAN cascade. We conduct an objective and subjective evaluation for different IAN setups in the addressed task of generating innovative samples and we show the effect of regularizing GAN on different scores. We conclude with some useful applications for these IANs, like multi-domain manifold traversing.

  8. Hollow Anode Cascading Plasma Focus | Alabraba | Journal of the ...

    African Journals Online (AJOL)

    Using the 3-phase model for each focus event, the 9-phase, two solid disc auxiliary anode cascading plasma focus has been extended to include holes at the center of each cascade anode (hereafter referred to as hollow anode cascading focus) with a view of increasing the neutron yield with each focus event. Results ...

  9. A simple method for potential flow simulation of cascades

    Indian Academy of Sciences (India)

    Keywords. Cascade; turbo-machinery; aerodynamics; conformal mapping. Abstract. A simple method using a combination of conformal mapping and vortex panel method to simulate potential flow in cascades is presented. The cascade is first transformed to a single body using a conformal mapping, and the potential flow ...

  10. Quantum Cascade Lasers Modulation and Applications

    Science.gov (United States)

    Luzhansky, Edward

    The mid-wave IR (MWIR) spectral band, extending from 3 to 5 microns, is considered to be a low loss atmospheric window. There are several spectral sub-bands with relatively low atmospheric attenuation in this region making it popular for various commercial and military applications. Relatively low thermal and solar background emissions, effective penetration through the natural and anthropogenic obscurants and eye safety add to the long list of advantages of MWIR wavelengths. Quantum Cascade Lasers are compact semiconductor devices capable of operating in MWIR spectrum. They are based on inter-subband transitions in a multiple-quantum-well (QW) hetero-structure, designed by means of band-structure engineering. The inter-subband nature of the optical transition has several key advantages. First, the emission wavelength is primarily a function of the QW thickness. This characteristic allows choosing well-understood and reliable semiconductors for the generation of light in a wavelength range of interest. Second, a cascade process in which tens of photons are generated per injected electron. This cascading process is behind the intrinsic high-power capabilities of QCLs. This dissertation is focused on modulation properties of Quantum Cascade Lasers. Both amplitude and phase/frequency modulations were studied including modulation bandwidth, modulation efficiency and chirp linearity. Research was consisted of the two major parts. In the first part we describe the theory of frequency modulation (FM) response of Distributed Feedback Quantum Cascade Lasers (DFB QCL). It includes cascading effect on the QCL's maximum modulation frequency. The "gain levering" effect for the maximum FM response of the two section QCLs was studied as well. In the second part of research we concentrated on the Pulse Position Amplitude Modulation of a single section QCL. The low complexity, low size, weight and power Mid-Wavelength Infra-Red optical communications transceiver concept is

  11. Biexciton cascade emission in multilayered organic nanofibers

    Science.gov (United States)

    Evaristo de Sousa, Leonardo; Ferreira da Cunha, Wiliam; Antônio da Silva Filho, Demétrio; de Oliveira Neto, Pedro Henrique

    2018-04-01

    The optical performance of multilayered organic nanofibers results from the dynamics of excited states in the system. Here, we show that the presence of biexcitons is crucial to correctly describe such dynamics. This may be the case even if the intensity of the light source is not high. The cascade emission mediated by biexcitons is mainly responsible for the behavior of the photoluminescence profile in the initial steps after light absorption. By using a combination of Kinetic Monte Carlo model and Genetic Algorithm, we simulate Time-Resolved Photoluminescence measurements of multilayered nanofibers. These simulations are compared with experimental results, thus revealing that the usual singlet exciton recombination is insufficient to reproduce the complete physical picture. Our results also include predictions for the behavior of the biexciton signal. These findings are observed to be valid for a wide temperature range, showing the importance of the biexciton cascade emission in several regimes for organic nanofibers in general.

  12. Cascade Apartments: Deep Energy Multifamily Retrofit

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, A. [Washington State Univ. Energy Program, Olympia, WA (United States); Mattheis, L. [Washington State Univ. Energy Program, Olympia, WA (United States); Kunkle, R. [Washington State Univ. Energy Program, Olympia, WA (United States); Howard, L. [Washington State Univ. Energy Program, Olympia, WA (United States); Lubliner, M. [Washington State Univ. Energy Program, Olympia, WA (United States)

    2014-02-01

    In December of 2009-10, King County Housing Authority (KCHA) implemented energy retrofit improvements in the Cascade multifamily community, located in Kent, Washington (marine climate.)This research effort involved significant coordination from stakeholders KCHA, WA State Department of Commerce, utility Puget Sound Energy, and Cascade tenants. This report focuses on the following three primary BA research questions: 1. What are the modeled energy savings using DOE low income weatherization approved TREAT software? 2. How did the modeled energy savings compare with measured energy savings from aggregate utility billing analysis? 3. What is the Savings to Investment Ratio (SIR) of the retrofit package after considering utility window incentives and KCHA capitol improvement funding.

  13. Cascaded impedance networks for NPC inverter

    DEFF Research Database (Denmark)

    Li, Ding; Gao, Feng; Loh, Poh Chiang

    2010-01-01

    Multilevel inverters are getting more and more attracted because they have better output waveform quality and lower semiconductor voltage stress. The Z-source NPC is a kind of single stage multilevel inverter which has the ability of voltage boost. But the boost capability is relatively low when...... they are subject to the renewable sources. To date, three distinct types of impedance networks can be summarized for implementing a hybrid source impedance network, which can in principle be combined and cascaded before connected to a NPC inverter by proposed two ways. The resulting cascaded impedance network NPC...... would have a higher output voltage gain. It is anticipated that it would help the formed inverters find applications in photovoltaic and other renewable systems, where a high voltage gain is usually requested. Experimental testing has already been conducted and verifies the theory....

  14. Cascaded Multicell Trans-Z-Source Inverters

    DEFF Research Database (Denmark)

    Li, Ding; Chiang Loh, Poh; Zhu, Miao

    2013-01-01

    Inverters with high-output voltage gain usually face the problem of high-input current flowing through their components. The problem might further be exaggerated if the inverters use high-frequency magnetic devices like transformers or coupled inductors. Leakage inductances of these devices must...... strictly be small to prevent overvoltages caused by switching of their winding currents. To avoid these related problems, cascaded trans-Z-source inverters are proposed. They use multiple magnetic cells in an alternately cascading pattern rather than a single magnetic cell with large turns ratio....... Simulation and experimental results have shown that the multicell inverters can produce the same high-voltage gain, while keeping currents and voltages of the components low. The inverters can also step down their output voltages like a traditional voltage-source inverter without compromising waveform...

  15. Cascade Apartments: Deep Energy Multifamily Retrofit

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, A. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mattheis, L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kunkle, R. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Howard, L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lubliner, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2014-02-01

    In December of 2009-10, King County Housing Authority (KCHA) implemented energy retrofit improvements in the Cascade multifamily community, located in Kent, Washington (marine climate.)This research effort involved significant coordination from stakeholders KCHA, WA State Department of Commerce, utility Puget Sound Energy, and Cascade tenants. This report focuses on the following three primary BA research questions : 1. What are the modeled energy savings using DOE low income weatherization approved TREAT software? 2. How did the modeled energy savings compare with measured energy savings from aggregate utility billing analysis? 3. What is the Savings to Investment Ratio (SIR) of the retrofit package after considering utility window incentives and KCHA capitol improvement funding.

  16. Cascadable spatial-soliton logic gates.

    Science.gov (United States)

    Blair, S; Wagner, K

    2000-11-10

    The three-terminal spatial-soliton angular-deflection geometry provides the characteristics of an inverting logic gate with gain, and phase-insensitive implementations can be realized by a number of specific nonlinear interactions between orthogonally polarized waves. In particular, numerical simulations of spatial-soliton dragging and collision are used to calculate the transfer functions of inverter and multiple configurations of two-input nor gates and to address their cascadability. These transfer functions converge in cascaded operation and suggest that fan-out greater than 2 with a large noise margin is attainable in a system with standardized signal levels. These results are obtained with the material properties of fused silica and are representative of low-loss Kerr media.

  17. Design Mining Microbial Fuel Cell Cascades

    OpenAIRE

    Preen, Richard J.; You, Jiseon; Bull, Larry; Ieropoulos, Ioannis A.

    2016-01-01

    Microbial fuel cells (MFCs) perform wastewater treatment and electricity production through the conversion of organic matter using microorganisms. For practical applications, it has been suggested that greater efficiency can be achieved by arranging multiple MFC units into physical stacks in a cascade with feedstock flowing sequentially between units. In this paper, we investigate the use of computational intelligence to physically explore and optimise (potentially) heterogeneous MFC designs ...

  18. Hadron cascades in iron and uranium

    CERN Document Server

    Fabjan, Christian Wolfgang; Lankford, A J; Rehak, P; Struczinski, W; Willis, W J

    1975-01-01

    Cascade developments of hadrons and electrons are studied in iron and uranium-238 through the measurement of the total ionization produced in a fine grained multiplate ion chamber array. In iron the distribution of total ionization is dominated by nuclear binding energy fluctuations. In uranium-238, however, this fluctuation is compensated by correlated fission energy deposit resulting in a considerable reduction in the measured ionization fluctuation. (7 refs).

  19. Cascade of circulations in fluid turbulence.

    Science.gov (United States)

    Eyink, Gregory L

    2006-12-01

    Kelvin's theorem on conservation of circulations is an essential ingredient of Taylor's theory of turbulent energy dissipation by the process of vortex-line stretching. In previous work, we have proposed a nonlinear mechanism for the breakdown of Kelvin's theorem in ideal turbulence at infinite Reynolds number. We develop here a detailed physical theory of this cascade of circulations. Our analysis is based upon an effective equation for large-scale coarse-grained velocity, which contains a turbulent-induced vortex force that can violate Kelvin's theorem. We show that singularities of sufficient strength, which are observed to exist in turbulent flow, can lead to nonvanishing dissipation of circulation for an arbitrarily small coarse-graining length in the effective equations. This result is an analog for circulation of Onsager's theorem on energy dissipation for singular Euler solutions. The physical mechanism of the breakdown of Kelvin's theorem is diffusion of lines of large-scale vorticity out of the advected loop. This phenomenon can be viewed as a classical analog of the Josephson-Anderson phase-slip phenomenon in superfluids due to quantized vortex lines. We show that the circulation cascade is local in scale and use this locality to develop concrete expressions for the turbulent vortex force by a multiscale gradient expansion. We discuss implications for Taylor's theory of turbulent dissipation and we point out some related cascade phenomena, in particular for magnetic flux in magnetohydrodynamic turbulence.

  20. Bounded Target Cascading in Hierarchical Design Optimization

    Directory of Open Access Journals (Sweden)

    Xiaoling Zhang

    2014-06-01

    Full Text Available For large scale systems, as a hierarchical multilevel decomposed design optimization method, analytical target cascading coordinates the inconsistency between the assigned targets and response in each level by a weighted-sum formulation. To avoid the problems associated with the weighting coefficients, single objective functions in the hierarchical design optimization are formulated by a bounded target cascading method in this paper. In the BTC method, a single objective optimization problem is formulated in the system level, and two kinds of coordination constraints are added: one is bound constraint for the design points based on the response from each subsystem level and the other is linear equality constraint for the common variables based on their sensitivities with respect to each subsystem. In each subsystem level, the deviation with target for design point is minimized in the objective function, and the common variables are constrained by target bounds. Therefore, in the BTC method, the targets are coordinated based on the optimization iteration information in the hierarchical design problem and the performance of the subsystems, and BTC method will converge to the global optimum efficiently. Finally, comparisons of the results from BTC method and the weighted-sum analytical target cascading method are presented and discussed.

  1. Modeling of cascade and sub-cascade formation at high pka energies in irradiated fusion structural materials

    International Nuclear Information System (INIS)

    Ryazanov, A.; Metelkin, E.V.; Semenov, E.A.

    2007-01-01

    Full text of publication follows: A new theoretical model is developed for the investigations of cascade and sub-cascade formation in fusion structural materials under fast neutron irradiation at high primary knock atom (PKA) energies. Under 14 MeV neutron irradiation especially of light fusion structural materials such as Be, C, SiC materials PKA will have the energies up to 1 MeV. At such high energies it is very difficult to use the Monte Carlo or molecular dynamic simulations. The developed model is based on the analytical consideration of elastic collisions between displaced moving atoms into atomic cascades produced by a PKAs with the some kinetic energy obtained from fast neutrons. The Tomas-Fermy interaction potential is used for the describing of elastic collisions between moving atoms. The suggested model takes into account also the electronic losses for moving atoms between elastic collisions. The self consistent criterion for sub-cascade formation is suggested here which is based on the comparison of mean distance between two consequent PKA collisions and size of sub-cascade produced by PKA. The analytical relations for the most important characteristics of cascades and sub-cascade are determined including the average number of sub-cascades per one PKA in the dependence on PKA energy, the distance between sub-cascades and the average cascade and sub-cascade sizes as a function of PKA energy. The developed model allows determining the total numbers, distribution functions of cascades and sub-cascades in dependence on their sizes and generation rate of cascades and sub-cascades for different fusion neutron energy spectra. Based on the developed model the numerical calculations for main characteristics of cascades and sub-cascades in different fusion structural materials are performed using the neutron flux and PKA energy spectra for fusion reactors: ITER and DEMO. The main characteristics for cascade and sub-cascade formation are calculated here for the

  2. Cascade plant control by timer method

    International Nuclear Information System (INIS)

    Kiguchi, Takashi; Inoue, Kotaro; Kawai, Toshio; Senoo, Makoto.

    1970-01-01

    The present invention relates to a method of controlling uranium flow rate through a cascaded centrifuge plant for the purpose of enriching uranium 235. Such a cascade includes multiple gas separation stage each of which consists of a plurality of centrifuges. The product gas usually includes a large amount of He gas, and a cold trap is used to eliminate the He from UF 6 . The cold trap is operated periodically in such a way that the mixed gas of He and UF 6 is cooled to solidify only UF 6 and then warmed to obtain UF 6 by gasification. In order to operate the plant continuously, parallel multiple cold traps are operated alternatively. The operating conditions in such a complex cascade system are difficult to alter by conventional control methods. The present invention provides a rapid method of controlling the system when a certain percentage of the centrifuges in one stage malfunction. The control system consists of timers which are provided one for each cold trap to control the operational period of the trap. For example, if 20% of the centrifuges in a particular stage malfunction, the timer period of the cold traps attached to the normally operating centrifuge within the stage is maintained, and the period of all the other centrifuges are changed to 10/8 times that of the initial value. In this way the flow volume through all centrifuges except that in the particular stage is reduced to 80% of the initial value and the operation of the system can be continued with reduced efficiency. (Masui, R.)

  3. Split energy cascade in turbulent thin fluid layers

    Science.gov (United States)

    Musacchio, Stefano; Boffetta, Guido

    2017-11-01

    We discuss the phenomenology of the split energy cascade in a three-dimensional thin fluid layer by means of high resolution numerical simulations of the Navier-Stokes equations. We observe the presence of both an inverse energy cascade at large scales, as predicted for two-dimensional turbulence, and a direct energy cascade at small scales, as in three-dimensional turbulence. The inverse energy cascade is associated with a direct cascade of enstrophy in the intermediate range of scales. Notably, we find that the inverse cascade of energy in this system is not a purely 2D phenomenon, as the coupling with the 3D velocity field is necessary to guarantee the constancy of fluxes.

  4. Atom localization with double-cascade configuration

    Science.gov (United States)

    Gordeev, Maksim Yu; Efremova, Ekaterina A.; Rozhdestvensky, Yuri V.

    2016-03-01

    We investigate the one-dimensional (1D) and two-dimensional (2D) atom localization of a four-level system in a double-cascade configuration. We demonstrate the possibility of 1D localization in the field of a standing wave, 2D localization in the field of two standing waves and 2D localization only in the field of running waves by using different configurations of driven waves on transitions. In addition, for each configuration we reached a high-precision atom localization in one of the states at scales much smaller than the wavelength of the incident optical radiation.

  5. Quadrotor trajectory tracking using PID cascade control

    Science.gov (United States)

    Idres, M.; Mustapha, O.; Okasha, M.

    2017-12-01

    Quadrotors have been applied to collect information for traffic, weather monitoring, surveillance and aerial photography. In order to accomplish their mission, quadrotors have to follow specific trajectories. This paper presents proportional-integral-derivative (PID) cascade control of a quadrotor for path tracking problem when velocity and acceleration are small. It is based on near hover controller for small attitude angles. The integral of time-weighted absolute error (ITAE) criterion is used to determine the PID gains as a function of quadrotor modeling parameters. The controller is evaluated in three-dimensional environment in Simulink. Overall, the tracking performance is found to be excellent for small velocity condition.

  6. The identification of a cascade hypernucleus

    CERN Document Server

    Mondal, A S; Husain, A; Kasim, M M

    1979-01-01

    In a systematic search for rare hypernuclear species in nuclear emulsion exposed to 3.0 GeV/c K/sup -/-mesons at the CERN PS, an event with three connecting stars has been observed. The two secondary stars are most probably due to the decay of a cascade hypernucleus according to the following channel: /sub Xi //sup -13/-C to /sub Lambda //sup 8 /Be+/sub Lambda //sup 5/He+Q. The binding energy of the Xi - hypernucleus is B/sub Xi /-(/sub Xi //sup 13/-C)=(18.1+or-3.2) MeV. (11 refs).

  7. Plant MAPK cascades: Just rapid signaling modules?

    KAUST Repository

    Boudsocq, Marie

    2015-08-27

    © 2015 Taylor & Francis Group, LLC. Abscisic acid (ABA) is a major phytohormone mediating important stress-related processes. We recently unveiled an ABA-activated MAPK signaling module constituted of MAP3K17/18-MKK3-MPK1/2/7/14. Unlike classical rapid MAPK activation, we showed that the activation of the new MAPK module is delayed and relies on the MAP3K protein synthesis. In this addendum, we discuss the role of this original and unexpected activation mechanism of MAPK cascades which suggests that MAPKs can regulate both early and longterm plant stress responses.

  8. The Cascade of Non-Stationarity

    Science.gov (United States)

    Belmont, P.; Kumarasamy, K.; Kelly, S. A.; Schaffrath, K. R.; Beach, T. J.

    2014-12-01

    Landscapes and channel networks are dynamic systems, often characterized by immense variability in time and space. Systematic shifts in hydrologic, geomorphic, or ecologic drivers can cause a cascade of changes within the system, which may fundamentally alter the way the system itself functions. Due to variability in resilience and resisting forces throughout the landscape, this cascade of changes may manifest in different ways within any given system. Humans may also exert considerable influence, often amplifying or damping system response. We illustrate the cascading effects of non-stationary hydrology and geomorphology in the Minnesota River Basin (MRB), a 44,000 km2 natural laboratory in which pervasive landscape disturbance has been triggered by several well-documented events. Rapid base-level lowering 13,400 YBP along the mainstem Minnesota River created a wave of incision, which continues to propagate up tributary channel networks. Temperature and precipitation have changed significantly in the MRB over the past century with rising temperatures, shifting precipitation patterns and an increase in heavy rainfall events. Streamflow has changed drastically and variably throughout the basin with 5% exceedance flows increasing 60-100% in recent decades, as increases in precipitation have been amplified by land management and artificial drainage. Increases in channel width and depth have occurred variably in the mainstem Minnesota River, the actively incising lower (knick zone) reaches of tributaries, and the low gradient, passively meandering reaches above the knick zones. Altered hydrologic regimes and channel morphologies, combined with increased sedimentation and nutrient loading have adversely affected aquatic biota via disruption of life cycles and habitat degradation. Existing landscape, water quality, and flood risk models are poorly equipped to deal with the cascading effects of non-stationarity and therefore may grossly over- or under

  9. Long-Haul TCP vs. Cascaded TCP

    OpenAIRE

    Feng, Wu-chun

    2006-01-01

    In this work, we investigate the bandwidth and transfer time of long-haul TCP versus cascaded TCP [5]. First, we discuss the models for TCP throughput. For TCP flows in support of bulk data transfer (i.e., long-lived TCP flows), the TCP throughput models have been derived [2, 3]. These models rely on the congestion-avoidance algorithm of TCP. Though these models cannot be applied with short-lived TCP connections, our interest relative to logistical networking is in longer-li...

  10. Multiheterodyne spectroscopy using interband cascade lasers

    Science.gov (United States)

    Sterczewski, Lukasz A.; Westberg, Jonas; Patrick, Charles Link; Kim, Chul Soo; Kim, Mijin; Canedy, Chadwick L.; Bewley, William W.; Merritt, Charles D.; Vurgaftman, Igor; Meyer, Jerry R.; Wysocki, Gerard

    2018-01-01

    While midinfrared radiation can be used to identify and quantify numerous chemical species, contemporary broadband midinfrared spectroscopic systems are often hindered by large footprints, moving parts, and high power consumption. In this work, we demonstrate multiheterodyne spectroscopy (MHS) using interband cascade lasers, which combines broadband spectral coverage with high spectral resolution and energy-efficient operation. The lasers generate up to 30 mW of continuous-wave optical power while consuming portable and high-resolution solid-state spectroscopic chemical sensors operating in the midinfrared.

  11. Atom localization with double-cascade configuration

    International Nuclear Information System (INIS)

    Gordeev, Maksim Yu; Rozhdestvensky, Yuri V; Efremova, Ekaterina A

    2016-01-01

    We investigate the one-dimensional (1D) and two-dimensional (2D) atom localization of a four-level system in a double-cascade configuration. We demonstrate the possibility of 1D localization in the field of a standing wave, 2D localization in the field of two standing waves and 2D localization only in the field of running waves by using different configurations of driven waves on transitions. In addition, for each configuration we reached a high-precision atom localization in one of the states at scales much smaller than the wavelength of the incident optical radiation. (paper)

  12. Cascaded recompression closed brayton cycle system

    Energy Technology Data Exchange (ETDEWEB)

    Pasch, James J.

    2018-01-02

    The present disclosure is directed to a cascaded recompression closed Brayton cycle (CRCBC) system and method of operation thereof, where the CRCBC system includes a compressor for compressing the system fluid, a separator for generating fluid feed streams for each of the system's turbines, and separate segments of a heater that heat the fluid feed streams to different feed temperatures for the system's turbines. Fluid exiting each turbine is used to preheat the fluid to the turbine. In an embodiment, the amount of heat extracted is determined by operational costs.

  13. Alterações dos folículos pilo-sebáceos em um caso de sindromo bolhoso do grupo pênfigo: presença de inclusões intranucleares das doenças por virus filtraveis

    Directory of Open Access Journals (Sweden)

    Carlos Gatti

    1947-12-01

    Full Text Available Tendo a oportunidade de estudar fragmentos de pele retirados de diversas regiões, algumas providas de abundante revestimento capilar, em um caso de autopsia de doente com sindromo bolhoso do grupo pênfigo, chamaram a nossa atenção as alterações histologicas dos folículos pilo-sebaceso, sôbre as quais não encontramos referencia especial na literatura que nos foi dado consultar.Several skin fragments were available for histological study some of them from hairy regions in a case of pemphigus vulgaris observed in Asunción, Paraguay, which came to autopsy. The lesions on the skin are similar to those described in "fogo selvagem", a subtype of pemphigus which is endemic and sometimes epidemic in South America. The hair follicle shows hyperplasia of the outer sheath (acanthosis, acantholysis, dyskeratosis as well as necrosis of epithelial cells, dilatation of its mouth, loosening and loos of the hair. The first changes mentioned are more or less similar to those described in the epidermis. The striking finding, however, is the presence in some of them of intranuclear inclusion bodies in most cells of the outer sheath. The enlarged nuclei show thickening of the nuclear membrane and condensation of most intranuclear structures in acidophilic corpuscles of irregular shape, sometimes single, other times multiple, always separated from the nuclear membrane by a clear space apparently deprived of structure. Remaining portions of the linin reticulum are sometimes recognised besides the inclusion bodies. Minute granules suggestive of elementary corpuscles appear scattered in other nuclei faintly blue stained (advanced stages of the intranuclear inclusion bodies?. Intranuclear inclusion bodies could be demonstrated also in the epithelial cells of sebaceous glands which presented changes similar to those found in the hair follicles, but never in the cells of the epidermis. The histological changes in the epidermis however were quite similar to those

  14. The comparison of extraction of energy in two-cascade and one-cascade targets

    Energy Technology Data Exchange (ETDEWEB)

    Dolgoleva, G. V., E-mail: dolgg@list.ru [National Research Tomsk State University, 36, Lenin Ave., 634050, Tomsk (Russian Federation); Ponomarev, I. V., E-mail: wingof17@mail.ru [Moscow State University, Department of Mechanics and Mathematics, 1, Vorobyovy Gory, Moscow,119961 (Russian Federation)

    2016-01-15

    The paper is devoted to numerical designing of cylindrical microtargets on the basis of shock-free compression. When designing microtargets for the controlled thermonuclear fusion, the core tasks are to select geometry and make-up of layers, and the law of energy embedding as well, which allow receiving of “burning” of deuterium- tritium mix, that is, the existence of thermonuclear reactions of working area. Yet, the energy yield as a result of thermonuclear reactions has to be more than the embedded energy (the coefficient of amplification is more than a unit). So, an important issue is the value of the embedded energy. The purpose of the present paper is to study the extraction of energy by working DT area in one-cascade and two-cascade targets. A bigger extraction of energy will contribute to a better burning of DT mix and a bigger energy yield as a result of thermonuclear reactions. The comparison of analytical results to numerical calculations is carried out. The received results show advantages of a two-cascade target compared to a one-cascade one.

  15. All passive architecture for high efficiency cascaded Raman conversion

    Science.gov (United States)

    Balaswamy, V.; Arun, S.; Chayran, G.; Supradeepa, V. R.

    2018-02-01

    Cascaded Raman fiber lasers have offered a convenient method to obtain scalable, high-power sources at various wavelength regions inaccessible with rare-earth doped fiber lasers. A limitation previously was the reduced efficiency of these lasers. Recently, new architectures have been proposed to enhance efficiency, but this came at the cost of enhanced complexity, requiring an additional low-power, cascaded Raman laser. In this work, we overcome this with a new, all-passive architecture for high-efficiency cascaded Raman conversion. We demonstrate our architecture with a fifth-order cascaded Raman converter from 1117nm to 1480nm with output power of ~64W and efficiency of 60%.

  16. Gas separation performance of tapered cascade with membrane

    International Nuclear Information System (INIS)

    Ohno, Masayoshi; Morisue, Tetsuo; Ozaki, Osamu; Miyauchi, Terukatsu.

    1978-01-01

    Membrane gas separation cascades are analyzed at steady state. The method of calculating the flow rate and concentration profiles in the cascade are examined, using formulas expressing the various membrane separation cell characteristics. The method adopted is applicable to relatively high concentrations and separation factors. Considerations are further given on the steady state performance of four theoretical forms of cascade: (a) with common value of cut for all stages, (b) with symmetric separation cells, (c) with no mixing at the junction at each stage, and (d) ideal cascade. The analysis showed that, with membrane cells, the ideal cascade would have a pressure ratio varying from stage to stage. The symmetric separation cascade would provide a separation performance lower than the ideal cascade on account of the mixing at the junctions of streams possessing different concentrations, whereas the cut and separation factor of the no-mixing cascade requiring minimum membrane area exhibits zig-zag curves when plotted against stage number. Both these circumstances contribute to the lower separation performance obtained with these two forms as compared with the ideal cascade, and results in larger total membrane area; but these semi-ideal forms retain the advantage of easy practical treatment with their pressure ratio common to all stages. (auth.)

  17. Systems theory and cascades in developmental psychopathology.

    Science.gov (United States)

    Cox, Martha J; Mills-Koonce, Roger; Propper, Cathi; Gariépy, Jean-Louis

    2010-08-01

    In the wake of prominent theoreticians in developmental science, whose contributions we review in this article, many developmental psychologists came to endorse a systems approach to understanding how the individual, as it develops, establishes functional relationships to social ecological contexts that from birth to school entry rapidly increase in complexity. The concept of developmental cascade has been introduced in this context to describe lawful processes by which antecedent conditions may be related with varying probabilities to specified outcomes. These are understood as processes by which function at one level or in one domain of behavior affect the organization of competency in later developing domains of general adaptation. Here we propose a developmental sequence by which the developing child acquires regulative capacities that are key to adjustment to a society that demands considerable control of emotional and cognitive functions early in life. We report empirical evidence showing that the acquisition of regulative capacities may be understood as a cascade of shifts in control parameters induced by the progressive integration of biological, transactional, and socioaffective systems over development. We conclude by suggesting how the developmental process may be accessed for effective intervention in populations deemed "at risk" for later problems of psychosocial adjustment.

  18. Cascade biocatalysis by multienzyme-nanoparticle assemblies.

    Science.gov (United States)

    Kang, Wei; Liu, Jiahui; Wang, Jianpeng; Nie, Yunyu; Guo, Zhihong; Xia, Jiang

    2014-08-20

    Multienzyme complexes are of paramount importance in biosynthesis in cells. Yet, how sequential enzymes of cascade catalytic reactions synergize their activities through spatial organization remains elusive. Recent development of site-specific protein-nanoparticle conjugation techniques enables us to construct multienzyme assemblies using nanoparticles as the template. Sequential enzymes in menaquinone biosynthetic pathway were conjugated to CdSe-ZnS quantum dots (QDs, a nanosized particulate material) through metal-affinity driven self-assembly. The assemblies were characterized by electrophoretic methods, the catalytic activities were monitored by reverse-phase chromatography, and the composition of the multienzyme-QD assemblies was optimized through a progressive approach to achieve highly efficient catalytic conversion. Shorter enzyme-enzyme distance was discovered to facilitate intermediate transfer, and a fine control on the stoichiometric ratio of the assembly was found to be critical for the maximal synergy between the enzymes. Multienzyme-QD assemblies thereby provide an effective model to scrutinize the synergy of cascade enzymes in multienzyme complexes.

  19. Turbulent cascades in foreign exchange markets

    Science.gov (United States)

    Ghashghaie, S.; Breymann, W.; Peinke, J.; Talkner, P.; Dodge, Y.

    1996-06-01

    THE availability of high-frequency data for financial markets has made it possible to study market dynamics on timescales of less than a day1. For foreign exchange (FX) rates Müller et al.2 have shown that there is a net flow of information from long to short timescales: the behaviour of long-term traders (who watch the markets only from time to time) influences the behaviour of short-term traders (who watch the markets continuously). Motivated by this hierarchical feature, we have studied FX market dynamics in more detail, and report here an analogy between these dynamics and hydrodynamic turbulence3-8. Specifically, the relationship between the probability density of FX price changes (δx) and the time delay (δt) (Fig. la) is much the same as the relationship between the probability density of the velocity differences (δv) of two points in a turbulent flow and their spatial separation δr (Fig. 1b). Guided by this similarity we claim that there is an information cascade in FX market dynamics that corresponds to the energy cascade in hydrodynamic turbulence. On the basis of this analogy we can now rationalize the statistics of FX price differences at different time delays, which is important for, for example, option pricing. The analogy also provides a conceptual framework for understanding the short-term dynamics of speculative markets.

  20. Cascaded clocks measurement and simulation findings

    Science.gov (United States)

    Chislow, Don; Zampetti, George

    1994-05-01

    This paper will examine aspects related to network synchronization distribution and the cascading of timing elements. Methods of timing distribution have become a much debated topic in standards forums and among network service providers (both domestically and internationally). Essentially these concerns focus on the need to migrate their existing network synchronization plans (and capabilities) to those required for the next generation of transport technologies (namely, the Synchronous Digital Hierarchy (SDH), Synchronous Optical Networks (SONET), and Asynchronous Transfer Mode (ATM). The particular choices for synchronization distribution network architectures are now being evaluated and are demonstrating that they can indeed have a profound effect on the overall service performance levels that will be delivered to the customer. The salient aspects of these concerns reduce to the following: (1) identifying that the devil is in the details of the timing element specifications and the distribution of timing information (i.e., small design choices can have a large performance impact); (2) developing a standardized method of performance verification that will yield unambiguous results; and (3) presentation of those results. Specifically, this will be done for two general cases: an ideal input, and a noisy input to a cascaded chain of slave clocks.

  1. Quaternary Magmatism in the Cascades - Geologic Perspectives

    Science.gov (United States)

    Hildreth, Wes

    2007-01-01

    Foreward The Cascade magmatic arc is a belt of Quaternary volcanoes that extends 1,250 km from Lassen Peak in northern California to Meager Mountain in Canada, above the subduction zone where the Juan de Fuca Plate plunges beneath the North American Plate. This Professional Paper presents a synthesis of the entire volcanic arc, addressing all 2,300 known Quaternary volcanoes, not just the 30 or so visually prominent peaks that comprise the volcanic skyline. Study of Cascade volcanoes goes back to the geological explorers of the late 19th century and the seminal investigations of Howel Williams in the 1920s and 1930s. However, major progress and application of modern scientific methods and instrumentation began only in the 1970s with the advent of systematic geological, geophysical, and geochemical studies of the entire arc. Initial stimulus from the USGS Geothermal Research Program was enhanced by the USGS Volcano Hazards Program following the 1980 eruption of Mount St. Helens. Together, these two USGS Programs have provided more than three decades of stable funding, staffing, and analytical support. This Professional Paper summarizes the resultant USGS data sets and integrates them with the parallel contributions of other investigators. The product is based upon an all-encompassing and definitive geological database, including chemical and isotopic analyses to characterize the rocks and geochronology to provide the critical time constraints. Until now, this massive amount of data has not been summarized, and a systematic and uniform interpretation firmly grounded in geological fact has been lacking. Herein lies the primary utility of this Cascade volume. It not only will be the mandatory starting point for new workers, but also will provide essential geological context to broaden the perspectives of current investigators of specific Cascade volcanoes. Wes Hildreth's insightful understanding of volcanic processes and his uncompromising scientific integrity make him

  2. The critical care cascade: a systems approach.

    Science.gov (United States)

    Ghosh, Rishi; Pepe, Paul

    2009-08-01

    To emphasize the evolving body of evidence that supports the need for a more seamless and interconnected continuum of patient care for a growing compendium of critical care conditions, starting in the prehospital and emergency department (ED) phases of management and continuing through ICU and rehabilitation services. The care of critically ill and injured patients has become increasingly complex. It now has been demonstrated that, for a number of such critical care conditions, optimal management not only relies heavily on the talents of highly coordinated, multidisciplinary teams, but it also may require shared responsibilities across a continuum of longitudinal care involving numerous specialties and departments. This continuum usually needs to begin in the prehospital and ED settings with management extending through specialized in-hospital diagnostic and interventional suites to traditional ICU and rehabilitation programs. In recent years, examples of these conditions have included the development of systems of care for trauma, cardiac arrest, myocardial infarction, stroke, sepsis syndromes, toxicology and other critical illnesses. Although the widespread implementation of such multidisciplinary, multispecialty critical care cascades of care has been achieved most commonly in trauma care, current healthcare delivery systems generally tend to employ compartmentalized organization for the majority of other critical care patients. Accordingly, optimal systematic care often breaks down in the management of these complex patients due to barriers such as lack of interoperable communication between teams, disjointed transfers between services, unnecessary time-consuming, re-evaluations and transitional pauses in time-dependent circumstances, deficiencies in cross-disciplinary education and quality assurance loops, and significant variability in patient care practices. Such barriers can lead to adverse outcomes in this fragile patient population. This article discusses

  3. 36 CFR 7.66 - North Cascades National Park.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false North Cascades National Park. 7.66 Section 7.66 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.66 North Cascades National Park. (a...

  4. A cascaded online uninterruptible power supply using reduced semiconductor

    DEFF Research Database (Denmark)

    Zhang, Lei; Loh, Poh Chiang; Gao, Feng

    2011-01-01

    A cascaded online uninterruptible power supply (UPS) is proposed here that uses 25% lesser semiconductor, as compared to its traditional H-bridge cascaded precedence. Unlike other component-saving configurations where compromises are unavoidable, almost no performance degradations and constraints...

  5. Intermittent Flow Regimes in a Transonic Fan Airfoil Cascade

    Directory of Open Access Journals (Sweden)

    J. Lepicovsky

    2004-01-01

    velocity.To date, this flow behavior has only been observed in a linear transonic cascade. Further research is necessary to confirm this phenomenon occurs in actual transonic fans and is not the by-product of an endwall restricted linear cascade.

  6. Climate Change and Baleen Whale Trophic Cascades in Greenland

    Science.gov (United States)

    2009-09-30

    DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited. Climate Change and Baleen Whale Trophic Cascades in Greenland...SUBTITLE Climate Change And Baleen Whale Trophic Cascades In Greenland 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S

  7. Hybrid Modulation Scheme for Cascaded H-Bridge Inverter Cells ...

    African Journals Online (AJOL)

    This work proposes a switching technique for cascaded H-Bridge (CHB) cells. Single carrier Sinusoidal PWM (SCSPWM) scheme is employed in the generation of the gating signals. A sequential switching and base PWM circulation schemes are presented for this fundamental cascaded multilevel inverter topology.

  8. A nine-level hybrid symmetric cascaded multilevel converter for ...

    Indian Academy of Sciences (India)

    Indrajit Sarkar

    Abstract. A nine-level hybrid symmetric cascaded multilevel converter (MLC) fed induction motor drive is proposed in this paper. The proposed converter is capable of producing nine output voltage levels by using the same number of power cells as that of conventional five-level symmetric cascaded H-bridge converter.

  9. Cascade vulnerability for risk analysis of water infrastructure.

    Science.gov (United States)

    Sitzenfrei, R; Mair, M; Möderl, M; Rauch, W

    2011-01-01

    One of the major tasks in urban water management is failure-free operation for at least most of the time. Accordingly, the reliability of the network systems in urban water management has a crucial role. The failure of a component in these systems impacts potable water distribution and urban drainage. Therefore, water distribution and urban drainage systems are categorized as critical infrastructure. Vulnerability is the degree to which a system is likely to experience harm induced by perturbation or stress. However, for risk assessment, we usually assume that events and failures are singular and independent, i.e. several simultaneous events and cascading events are unconsidered. Although failures can be causally linked, a simultaneous consideration in risk analysis is hardly considered. To close this gap, this work introduces the term cascade vulnerability for water infrastructure. Cascade vulnerability accounts for cascading and simultaneous events. Following this definition, cascade risk maps are a merger of hazard and cascade vulnerability maps. In this work cascade vulnerability maps for water distribution systems and urban drainage systems based on the 'Achilles-Approach' are introduced and discussed. It is shown, that neglecting cascading effects results in significant underestimation of risk scenarios.

  10. Influence of blood flow on the coagulation cascade

    DEFF Research Database (Denmark)

    The influence of diffusion and convetive flows on the blood coagulation cascade is investigated for a controlled perfusion experiment. We present a cartoon model and reaction schemes for parts of the coagulation cascade with sunsequent set up of a mathematical model in two space dimensions plus one...

  11. A nine-level hybrid symmetric cascaded multilevel converter for ...

    Indian Academy of Sciences (India)

    A nine-level hybrid symmetric cascaded multilevel converter (MLC) fed induction motor drive is proposed in this paper. The proposed converter is capable of producing nine output voltage levels by using the same number of power cells as that of conventional five-level symmetric cascaded H-bridge converter. Eachphase in ...

  12. Decoherence in high barrier quantum cascade structures

    Science.gov (United States)

    Freeman, Will

    2017-07-01

    High barrier AlxGa1-xAs terahertz quantum cascade structures with AlAs compositions up to 30% are studied. The influence of thermally excited leakage scattering to higher bound energy states and decoherence effects are investigated using a density matrix method where the pure dephasing time is self-consistently solved. The lattice temperature dependence of the light output in diagonal optical transition structures is calculated and shown to be consistent with experiment. Scattering from the upper lasing state to higher bound energy states is found to have minimal effects, and rather the decoherence from the calculated reduction of the pure dephasing time due to the impurity interaction is primarily responsible for the temperature dependence of a recently reported structure. This shows that the effects from an increased impurity interaction due to thinner barriers and different well dimensions can dominate over that from the increased interface roughness interaction due to higher potentials.

  13. Prolate yrast cascade in 183Tl

    International Nuclear Information System (INIS)

    Reviol, W.; Carpenter, M. P.; Janssens, R. V. F.; Jenkins, D.; Toth, K. S.; Bingham, C. R.; Riedinger, L. L.; Weintraub, W.; Cizewski, J. A.; Lauritsen, T.

    2000-01-01

    The yrast sequence in 183 Tl has been studied for the first time in recoil-mass selected γ-ray spectroscopic measurements. A rotational-like cascade of seven transitions is established down to the band head with probable spin and parity (13/2 + ). Unlike in the adjacent odd-mass Tl nuclei, prompt γ decay from the yrast band to a lower lying weakly deformed (oblate) structure is not observed. These features are consistent with the predicted drop of the prolate band head in 183 Tl compared to 185 Tl. The implications for the prolate energy minimum in odd-mass Tl nuclei at the neutron i 13/2 midshell (N=103) are discussed. (c) 2000 The American Physical Society

  14. Cascaded face alignment via intimacy definition feature

    Science.gov (United States)

    Li, Hailiang; Lam, Kin-Man; Chiu, Man-Yau; Wu, Kangheng; Lei, Zhibin

    2017-09-01

    Recent years have witnessed the emerging popularity of regression-based face aligners, which directly learn mappings between facial appearance and shape-increment manifolds. We propose a random-forest based, cascaded regression model for face alignment by using a locally lightweight feature, namely intimacy definition feature. This feature is more discriminative than the pose-indexed feature, more efficient than the histogram of oriented gradients feature and the scale-invariant feature transform feature, and more compact than the local binary feature (LBF). Experimental validation of our algorithm shows that our approach achieves state-of-the-art performance when testing on some challenging datasets. Compared with the LBF-based algorithm, our method achieves about twice the speed, 20% improvement in terms of alignment accuracy and saves an order of magnitude on memory requirement.

  15. Cascaded Quadratic Soliton Compression in Waveguide Structures

    DEFF Research Database (Denmark)

    Guo, Hairun

    to further push such multi-cycle pulses into few-cycle and even single-cycle. In this thesis, we investigate the high order soliton compression in quadratic nonlinear waveguide structures, which is a one-step pulse compression scheme making use of the soliton regime -- with the spontaneous cancelation...... and self-defocusing Kerr effect so that the soliton is created and the soliton self-compression happens in the normal dispersion region. Meanwhile, the chromatic dispersion in the waveguide is also tunable, understood as the dispersion engineering with structural designs. Therefore, compared to commonly...... used two-step compression scheme with e.g. hollow-core photonic crystal fibers plus a dispersion compensation component, our scheme, called the cascaded quadratic soliton compression (CQSC), provides a simpler setup with larger tunability on the nonlinearity, and could avoid the problem with the self...

  16. RG cascades in hyperbolic quiver gauge theories

    International Nuclear Information System (INIS)

    Ahl Laamara, R.; Ait Ben Haddou, M.; Belhaj, A.; Drissi, L.B.; Saidi, E.H.

    2004-01-01

    In this paper, we provide a general classification of supersymmatric QFT4s into three basic sets: ordinary, affine and indefinite classes. The last class, which has not been enough explored in literature, is shown to share most of properties of ordinary and affine super-QFT4s. This includes, amongst others, its embedding in type II string on local Calabi-Yau threefolds. We give realizations of these supersymmetric QFT4s as D-brane world volume gauge theories. A special interest is devoted to hyperbolic subset for its peculiar features and for the role it plays in type IIB background with non-zero axion. We also study RG flows and duality cascades in case of hyperbolic quiver theories. Comments regarding the full indefinite sector are made

  17. Cascaded FSO-VLC Communication System

    KAUST Repository

    Gupta, Akash

    2017-08-28

    The proposed cascaded free space optics (FSO)-visible light communication (VLC) system consists of multiple VLC access points which caters the end users connected via a decode and forward (DF) relay to the FSO backhaul link. The FSO link is assumed to be affected by path-loss, pointing error and atmospheric turbulence while the end-to-end signal-to-noise ratio (SNR) of VLC downlinks are statistically characterized considering the randomness of users position. In this study, the novel closed form expressions of the statistics like probability density function (PDF) and cumulative distribution function (CDF) of the equivalent SNR are derived. Capitalizing on these, the closed form expressions for various performance metrics such as outage probability and error probability are provided. The simulation results are provided to verify the functional curves of mathematical analysis.

  18. Mid infrared DFB interband cascade lasers

    Science.gov (United States)

    Koeth, J.; Weih, R.; Scheuermann, J.; Fischer, M.; Schade, A.; Kamp, M.; Höfling, S.

    2017-08-01

    The mid infrared spectral range (MIR) is of great interest for a variety of industrial, medical and environmental applications since numerous molecules have strong absorption lines therein. Interband cascade lasers (ICLs) have the ability to cover the entire MIR almost independently from the bandgap of the utilized semiconductors. Combined with a DFB technology which is applicable for most kinds of interband transition based semiconductor lasers the spectral range between 2.8 and 5.9 μm could be covered with application grade single mode devices with low power consumption. Recent optimizations regarding the layer design as well as the device processing yielded DFB laser chips with improved performance that will pave the way for a variety of applications that benefit from reasonable output power.

  19. Seeking heavy Higgs bosons through cascade decays

    Science.gov (United States)

    Coleppa, Baradhwaj; Fuks, Benjamin; Poulose, P.; Sahoo, Shibananda

    2018-04-01

    We investigate the LHC discovery prospects for a heavy Higgs boson decaying into the standard model Higgs boson and additional weak bosons. We consider a generic model-independent new physics configuration where this decay proceeds via a cascade involving other intermediate scalar bosons and focus on an LHC final-state signature comprised either of four b -jets and two charged leptons or of four charged leptons and two b -jets. We design two analyses of the corresponding signals, and demonstrate that a 5 σ discovery at the 14 TeV LHC is possible for various combinations of the parent and daughter Higgs-boson masses. We moreover find that the standard model backgrounds can be sufficiently rejected to guarantee the reconstruction of the parent Higgs boson mass. We apply our analyses to the Type-II two-Higgs-doublet model and identify the regions of the parameter space to which the LHC is sensitive.

  20. Availability Cascades and the Sharing Economy

    DEFF Research Database (Denmark)

    Netter, Sarah

    2016-01-01

    As scholars search for a new concept that will provide answers on how modern societies should make sense of and resolve the social and environmental problems linked to our modes of production and consumption, the sharing economy is attracting increased attention. To better understand this emergent...... focus on a sharing economy and associated business and consumption models, this conceptual chapter applies cascade theory to some of the most pronounced narratives , suggesting a win-win scenario, especially as they relate to the claim of sustainability. Given academics, practitioners, and civil society......’s shared history of (too) rapidly embracing new concepts that enable both business opportunities and a clear conscience, this chapter proposes that the implications of the sharing economy should be critically explored before it is actively promoted as the latest best fix....

  1. Ion-irradiation studies of cascade damage in metals

    International Nuclear Information System (INIS)

    Averback, R.S.

    1982-03-01

    Ion-irradiation studies of the fundamental aspects of cascade damage in metals are reviewed. The emphasis of these studies has been the determination of the primary state of damage (i.e. the arrangement of atoms in the cascade region prior to thermal migration of defects). Progress has been made towards understanding the damage function (i.e. the number of Frenkel pairs produced as a function of primary recoil atom energy), the spatial configuration of vacancies and interstitials in the cascade and the cascade-induced mixing of atoms. It is concluded for these studies that the agitation of the lattice in the vicinity of energetic displacement cascades stimulates the defect motion and that such thermal spike motion induces recombination and clustering of Frenkel defects. 9 figures

  2. Risk Assessment of Cascading Outages: Methodologies and Challenges

    Energy Technology Data Exchange (ETDEWEB)

    Vaiman, Marianna; Bell, Keith; Chen, Yousu; Chowdhury, Badrul; Dobson, Ian; Hines, Paul; Papic, Milorad; Miller, Stephen; Zhang, Pei

    2012-05-31

    Abstract- This paper is a result of ongoing activity carried out by Understanding, Prediction, Mitigation and Restoration of Cascading Failures Task Force under IEEE Computer Analytical Methods Subcommittee (CAMS). The task force's previous papers are focused on general aspects of cascading outages such as understanding, prediction, prevention and restoration from cascading failures. This is the first of two new papers, which extend this previous work to summarize the state of the art in cascading failure risk analysis methodologies and modeling tools. This paper is intended to be a reference document to summarize the state of the art in the methodologies for performing risk assessment of cascading outages caused by some initiating event(s). A risk assessment should cover the entire potential chain of cascades starting with the initiating event(s) and ending with some final condition(s). However, this is a difficult task and heuristic approaches and approximations have been suggested. This paper discusses different approaches to this and suggests directions for future development of methodologies. The second paper summarizes the state of the art in modeling tools for risk assessment of cascading outages.

  3. Cascading Failures as Continuous Phase-Space Transitions

    Science.gov (United States)

    Yang, Yang; Motter, Adilson E.

    2017-12-01

    In network systems, a local perturbation can amplify as it propagates, potentially leading to a large-scale cascading failure. Here we derive a continuous model to advance our understanding of cascading failures in power-grid networks. The model accounts for both the failure of transmission lines and the desynchronization of power generators and incorporates the transient dynamics between successive steps of the cascade. In this framework, we show that a cascade event is a phase-space transition from an equilibrium state with high energy to an equilibrium state with lower energy, which can be suitably described in a closed form using a global Hamiltonian-like function. From this function, we show that a perturbed system cannot always reach the equilibrium state predicted by quasi-steady-state cascade models, which would correspond to a reduced number of failures, and may instead undergo a larger cascade. We also show that, in the presence of two or more perturbations, the outcome depends strongly on the order and timing of the individual perturbations. These results offer new insights into the current understanding of cascading dynamics, with potential implications for control interventions.

  4. A thermal modelling of displacement cascades in uranium dioxide

    Science.gov (United States)

    Martin, G.; Garcia, P.; Sabathier, C.; Devynck, F.; Krack, M.; Maillard, S.

    2014-05-01

    The space and time dependent temperature distribution was studied in uranium dioxide during displacement cascades simulated by classical molecular dynamics (MD). The energy for each simulated radiation event ranged between 0.2 keV and 20 keV in cells at initial temperatures of 700 K or 1400 K. Spheres into which atomic velocities were rescaled (thermal spikes) have also been simulated by MD to simulate the thermal excitation induced by displacement cascades. Equipartition of energy was shown to occur in displacement cascades, half of the kinetic energy of the primary knock-on atom being converted after a few tenths of picoseconds into potential energy. The kinetic and potential parts of the system energy are however subjected to little variations during dedicated thermal spike simulations. This is probably due to the velocity rescaling process, which impacts a large number of atoms in this case and would drive the system away from a dynamical equilibrium. This result makes questionable MD simulations of thermal spikes carried out up to now (early 2014). The thermal history of cascades was compared to the heat equation solution of a punctual thermal excitation in UO2. The maximum volume brought to a temperature above the melting temperature during the simulated cascade events is well reproduced by this simple model. This volume eventually constitutes a relevant estimate of the volume affected by a displacement cascade in UO2. This definition of the cascade volume could also make sense in other materials, like iron.

  5. Cascade multiplicity inside deuteron in Π d high energy collisions

    International Nuclear Information System (INIS)

    Kisielewska, D.

    1983-01-01

    Multiplicity distribution of double scattering events is analysed using the additive quark model including the cascading effect. The mean multiplicity of particles produced in the process of cascading estimated for Π d experiments at 100, 205 and 360 GeV/c is equal to 1.15 ± .31. This value does not depend on the momentum of the incident pion. Some indications are found that the probability of cascading depends on multiplicity of the collision with the first nucleon and is smaller for low multiplicities. (author)

  6. MCDF calculations of Auger cascade processes

    Science.gov (United States)

    Beerwerth, Randolf; Fritzsche, Stephan

    2017-10-01

    We model the multiple ionization of near-neutral core-excited atoms where a cascade of Auger processes leads to the emission of several electrons. We utilize the multiconfiguration Dirac-Fock (MCDF) method to generate approximate wave functions for all fine-structure levels and to account for all decays between them. This approach allows to compute electron spectra, the population of final-states and ion yields, that are accessible in many experiments. Furthermore, our approach is based on the configuration interaction method. A careful treatment of correlation between electronic configurations enables one to model three-electron processes such as an Auger decay that is accompanied by an additional shake-up transition. Here, this model is applied to the triple ionization of atomic cadmium, where we show that the decay of inner-shell 4p holes to triply-charged final states is purely due to the shake-up transition of valence 5s electrons. Contribution to the Topical Issue "Atomic and Molecular Data and their Applications", edited by Gordon W.F. Drake, Jung-Sik Yoon, Daiji Kato, Grzegorz Karwasz.

  7. Optimization Issues in a Harmonic Cascade FEL

    CERN Document Server

    De Ninno, G

    2005-01-01

    Presently there is significant interest by multiple groups (e.g. BNL, ELETTRA, LBNL, BESSY, MIT) to reach short output wavelengths via a harmonic cascade FEL using an external seed laser. In a multistage device, there are a number of "free" parameters such as the nominal power of the input seed, the lengths of the individual modulator and radiator undulators, the strengths (i.e. the R56's) of the dispersive sections, the choice of the actual harmonic numbers to reach a given wavelength, etc., whose optimization is a non-trivial exercise. In particular, one can choose whether to operate predominantly in the "high gain" regime such as was proposed by Yu [1] in which case each radiator undulator is many gain lengths long or, alternatively, in the "low gain" regime in which case all undulators (except possibly the last radiator) are a couple gain lengths or less long and the output from each radiator essentially corresponds to coherent spontaneous emission from a pre-bunched beam. With particular emphasis upon th...

  8. Cascading reminiscence bumps in popular music.

    Science.gov (United States)

    Krumhansl, Carol Lynne; Zupnick, Justin Adam

    2013-10-01

    Autobiographical memories are disproportionately recalled for events in late adolescence and early adulthood, a phenomenon called the reminiscence bump. Previous studies on music have found autobiographical memories and life-long preferences for music from this period. In the present study, we probed young adults' personal memories associated with top hits over 5-and-a-half decades, as well as the context of their memories and their recognition of, preference for, quality judgments of, and emotional reactions to that music. All these measures showed the typical increase for music released during the two decades of their lives. Unexpectedly, we found that the same measures peaked for the music of participants' parents' generation. This finding points to the impact of music in childhood and suggests that these results reflect the prevalence of music in the home environment. An earlier peak occurred for 1960s music, which may be explained by its quality or by its transmission through two generations. We refer to this pattern of musical cultural transmission over generations as cascading reminiscence bumps.

  9. Dissipation range turbulent cascades in plasmas

    International Nuclear Information System (INIS)

    Terry, P. W.; Almagri, A. F.; Forest, C. B.; Nornberg, M. D.; Rahbarnia, K.; Sarff, J. S.; Fiksel, G.; Hatch, D. R.; Jenko, F.; Prager, S. C.; Ren, Y.

    2012-01-01

    Dissipation range cascades in plasma turbulence are described and spectra are formulated from the scaled attenuation in wavenumber space of the spectral energy transfer rate. This yields spectra characterized by the product of a power law and exponential fall-off, applicable to all scales. Spectral indices of the power law and exponential fall-off depend on the scaling of the dissipation, the strength of the nonlinearity, and nonlocal effects when dissipation rates of multiple fluctuation fields are different. The theory is used to derive spectra for MHD turbulence with magnetic Prandtl number greater than unity, extending previous work. The theory is also applied to generic plasma turbulence by considering the spectrum from damping with arbitrary wavenumber scaling. The latter is relevant to ion temperature gradient turbulence modeled by gyrokinetics. The spectrum in this case has an exponential component that becomes weaker at small scale, giving a power law asymptotically. Results from the theory are compared to three very different types of turbulence. These include the magnetic plasma turbulence of the Madison Symmetric Torus, the MHD turbulence of liquid metal in the Madison Dynamo Experiment, and gyrokinetic simulation of ion temperature gradient turbulence.

  10. Chemical sensors based on quantum cascade lasers

    Science.gov (United States)

    Tittel, Frank K.; Kosterev, Anatoliy A.; Rochat, Michel; Beck, Mattias; Faist, Jerome

    2002-09-01

    There is an increasing need in many chemical sensing applications ranging from industrial process control to environmental science and medical diagnostics for fast, sensitive, and selective gas detection based on laser spectroscopy. The recent availability of novel pulsed and cw quantum cascade distributed feedback (QC-DFB) lasers as mid-infrared spectroscopic sources address this need. A number of spectroscopic techniques have been demonstrated. For example, the authors have employed QC-DFB lasers for the monitoring and quantification of several trace gases and isotopic species in ambient air at ppmv and ppbv levels by means of direct absorption, wavelength modulation, cavity enhanced and cavity ringdown spectroscopy. In this work, pulsed thermoelectrically cooled QC-DFB lasers operating at ~15.6 μm were characterized for spectroscopic gas sensing applications. A new method for wavelength scanning based on the repetition rate modulation was developed. A non-wavelength-selective pyroelectric detector was incorporated in the gas sensor giving an advantage of room-temperature operation and low cost. Absorption lines of CO2 and H2O were observed in ambient air providing information about the concentration of these species.

  11. Cascaded Amplitude Modulations in Sound Texture Perception

    Directory of Open Access Journals (Sweden)

    Richard McWalter

    2017-09-01

    Full Text Available Sound textures, such as crackling fire or chirping crickets, represent a broad class of sounds defined by their homogeneous temporal structure. It has been suggested that the perception of texture is mediated by time-averaged summary statistics measured from early auditory representations. In this study, we investigated the perception of sound textures that contain rhythmic structure, specifically second-order amplitude modulations that arise from the interaction of different modulation rates, previously described as “beating” in the envelope-frequency domain. We developed an auditory texture model that utilizes a cascade of modulation filterbanks that capture the structure of simple rhythmic patterns. The model was examined in a series of psychophysical listening experiments using synthetic sound textures—stimuli generated using time-averaged statistics measured from real-world textures. In a texture identification task, our results indicated that second-order amplitude modulation sensitivity enhanced recognition. Next, we examined the contribution of the second-order modulation analysis in a preference task, where the proposed auditory texture model was preferred over a range of model deviants that lacked second-order modulation rate sensitivity. Lastly, the discriminability of textures that included second-order amplitude modulations appeared to be perceived using a time-averaging process. Overall, our results demonstrate that the inclusion of second-order modulation analysis generates improvements in the perceived quality of synthetic textures compared to the first-order modulation analysis considered in previous approaches.

  12. A simple method for potential flow simulation of cascades

    Indian Academy of Sciences (India)

    machinery; aerodynamics; conformal mapping. 1. Introduction. Potential flow in cascades is a well-studied problem. Gostelow (1984) gives reference to several sources in the literature where such studies have been undertaken. Broadly, the problem ...

  13. Packaged, cascadable wideband monolithic feedback amplifiers for radar systems applications

    OpenAIRE

    Alleva, V.; Calori, M.; Cetronio, A.; Lanzieri, C.; Proietti, C.; Rapisarda, S.

    1990-01-01

    Design criteria and fabrication of a packaged, monolithic, cascadable, feedback amplifier are presented. The good performances in term of bandwidth, gain, flatness, reproducibility and reliability makes this component highly suitable for many radar applications.

  14. Enantiomer separation in a cascaded micellar-enhanced ultrafiltration system

    NARCIS (Netherlands)

    Overdevest, P.E.M.; Hoenders, M.H.J.; Riet, van 't K.; Padt, van der A.; Keurentjes, J.T.F.

    2002-01-01

    The increasing demand for optically pure compounds (enantiomers) stimulates the development of new enantiomer separation processes on an industrial scale. The separation of enantiomers by ultrafiltration of enantioselective micelles was studied in a cascaded system. The feasibility of this

  15. Numerical optimization of a transcritical CO2/propylene cascaded ...

    Indian Academy of Sciences (India)

    - rofluorocarbons have been criticized for their adverse impact on the Earth's protective ozone layer and for their significant global warming potential (GWP). CO2 has been receiving great concern as an alternative refrigerant. Cascade ...

  16. Minimum Entropy-Based Cascade Control for Governing Hydroelectric Turbines

    Directory of Open Access Journals (Sweden)

    Mifeng Ren

    2014-06-01

    Full Text Available In this paper, an improved cascade control strategy is presented for hydroturbine speed governors. Different from traditional proportional-integral-derivative (PID control and model predictive control (MPC strategies, the performance index of the outer controller is constructed by integrating the entropy and mean value of the tracking error with the constraints on control energy. The inner controller is implemented by a proportional controller. Compared with the conventional PID-P and MPC-P cascade control methods, the proposed cascade control strategy can effectively decrease fluctuations of hydro-turbine speed under non-Gaussian disturbance conditions in practical hydropower plants. Simulation results show the advantages of the proposed cascade control method.

  17. On periodic orbits in discrete-time cascade systems

    Directory of Open Access Journals (Sweden)

    Huimin Li

    2006-01-01

    Full Text Available We present some results on existence, minimum period, number of periodic orbits, and stability of periodic orbits in discrete-time cascade systems. Some examples are presented to illustrate these results.

  18. Cascade Structure of Digital Predistorter for Power Amplifier Linearization

    Directory of Open Access Journals (Sweden)

    E. B. Solovyeva

    2015-12-01

    Full Text Available In this paper, a cascade structure of nonlinear digital predistorter (DPD synthesized by the direct learning adaptive algorithm is represented. DPD is used for linearization of power amplifier (PA characteristic, namely for compensation of PA nonlinear distortion. Blocks of the cascade DPD are described by different models: the functional link artificial neural network (FLANN, the polynomial perceptron network (PPN and the radially pruned Volterra model (RPVM. At synthesis of the cascade DPD there is possibility to overcome the ill conditionality problem due to reducing the dimension of DPD nonlinear operator approximation. Results of compensating nonlinear distortion in Wiener–Hammerstein model of PA at the GSM–signal with four carriers are shown. The highest accuracy of PA linearization is produced by the cascade DPD containing PPN and RPVM.

  19. Damped trophic cascades driven by fishing in model marine ecosystems

    DEFF Research Database (Denmark)

    Andersen, Ken Haste; Pedersen, Martin

    2010-01-01

    The largest perturbation on upper trophic levels of many marine ecosystems stems from fishing. The reaction of the ecosystem goes beyond the trophic levels directly targeted by the fishery. This reaction has been described either as a change in slope of the overall size spectrum or as a trophic...... cascade triggered by the removal of top predators. Here we use a novel size- and trait-based model to explore how marine ecosystems might react to perturbations from different types of fishing pressure. The model explicitly resolves the whole life history of fish, from larvae to adults. The results show...... that fishing does not change the overall slope of the size spectrum, but depletes the largest individuals and induces trophic cascades. A trophic cascade can propagate both up and down in trophic levels driven by a combination of changes in predation mortality and food limitation. The cascade is damped...

  20. Quantum cascade laser infrared spectroscopy of single cancer cells

    KAUST Repository

    Patel, Imran

    2017-03-27

    Quantum cascade laser infrared spectroscopy is a next generation novel imaging technique allowing high resolution spectral imaging of cells. We show after spectral pre-processing, identification of different cancer cell populations within minutes.

  1. Production of defects in metals by collision cascades: TEM experiments

    International Nuclear Information System (INIS)

    Kirk, M.A.

    1995-01-01

    The author reviews his experimental TEM data on the production of dislocation loops by low energy ion bombardment to low doses, as simulations of similar collision cascades produced by fast neutron irradiation, in various metal and alloys. The dependence of vacancy dislocation loop formation on recoil energy, sample temperature, and specific metal or alloy will be examined. Special emphasis will be placed on the effects of dilute alloy additions. A model for cascade melting will be employed to understand these effects, and will require an examination of the role of electron-phonon coupling in cascade cooling and recrystallization. The formation of interstitial dislocation loops as cascade defects, and the influence of the nearby surfaces in these experiments will be briefly discussed

  2. A cascading failure model for analyzing railway accident causation

    Science.gov (United States)

    Liu, Jin-Tao; Li, Ke-Ping

    2018-01-01

    In this paper, a new cascading failure model is proposed for quantitatively analyzing the railway accident causation. In the model, the loads of nodes are redistributed according to the strength of the causal relationships between the nodes. By analyzing the actual situation of the existing prevention measures, a critical threshold of the load parameter in the model is obtained. To verify the effectiveness of the proposed cascading model, simulation experiments of a train collision accident are performed. The results show that the cascading failure model can describe the cascading process of the railway accident more accurately than the previous models, and can quantitatively analyze the sensitivities and the influence of the causes. In conclusion, this model can assist us to reveal the latent rules of accident causation to reduce the occurrence of railway accidents.

  3. Terahertz Quantum Cascade Laser Based 3D Imaging Project

    Data.gov (United States)

    National Aeronautics and Space Administration — LongWave Photonics proposes a terahertz quantum-cascade laser based swept-source optical coherence tomography (THz SS-OCT) system for single-sided, 3D,...

  4. Vulnerability and Cosusceptibility Determine the Size of Network Cascades

    Science.gov (United States)

    Yang, Yang; Nishikawa, Takashi; Motter, Adilson E.

    2017-01-01

    In a network, a local disturbance can propagate and eventually cause a substantial part of the system to fail in cascade events that are easy to conceptualize but extraordinarily difficult to predict. Here, we develop a statistical framework that can predict cascade size distributions by incorporating two ingredients only: the vulnerability of individual components and the cosusceptibility of groups of components (i.e., their tendency to fail together). Using cascades in power grids as a representative example, we show that correlations between component failures define structured and often surprisingly large groups of cosusceptible components. Aside from their implications for blackout studies, these results provide insights and a new modeling framework for understanding cascades in financial systems, food webs, and complex networks in general.

  5. Molecular dynamics simulation of displacement cascades in iron-alpha

    International Nuclear Information System (INIS)

    Vascon, R.

    1997-01-01

    Radiation damage by neutrons or ions in bcc iron has been investigated by molecular dynamics simulations using an embedded atom type many-body potential (EAM). Displacement cascades with energies of 1 to 30 keV were generated in the microcanonical system where the number of atoms (up to 1.5 million) is chosen high enough to compensate the fact that the dissipation of energy is not taken into account in our model. The defect number at the end of cascade lifetime was found to be 60 percent of the NRT standard value. This tendency is in good agreement with experimental data. However, compared with other simulations in iron, we found significant differences in the defect production and distribution. The comparison with results obtained form simulations of cascades in other metals, leads on the one hand to a higher value of the defect number in bcc iron than in fcc metals like copper or nickel, and on the other hand to a ratio, between the number of replacements and the number of defects, lower in iron ( 100). We observed the transient melting of the core of the cascade during simulations. We showed that a higher value of the initial iron crystal temperature, as the mass difference between the components of an artificial binary alloy Fe-X(X=Al,Sb,Au,U) both produce a 'cascade effect': a decrease of the number of defects and an increase of the number of replacements. We also showed up the quasi-channeling of some atoms in high energy cascades. They are at the origin of sub-cascades formation; as a result they induce an opposite effect to the 'cascade effect'. (author)

  6. Cascaded Soliton Compression of Energetic Femtosecond Pulses at 1030 nm

    DEFF Research Database (Denmark)

    Bache, Morten; Zhou, Binbin

    2012-01-01

    We discuss soliton compression with cascaded second-harmonic generation of energetic femtosecond pulses at 1030 nm. We discuss problems encountered with soliton compression of long pulses and show that sub-10 fs compressed pulses can be achieved.......We discuss soliton compression with cascaded second-harmonic generation of energetic femtosecond pulses at 1030 nm. We discuss problems encountered with soliton compression of long pulses and show that sub-10 fs compressed pulses can be achieved....

  7. Critical Boundary of Cascaded Quadratic Soliton Compression in PPLN

    DEFF Research Database (Denmark)

    Guo, Hairun; Zeng, Xianglong; Zhou, Binbin

    2012-01-01

    Cascaded quadratic soliton compression in PPLN is investigated and a general critical soliton number is found as the compression boundary. An optimal-parameter diagram for compression at 1550 nm is presented.......Cascaded quadratic soliton compression in PPLN is investigated and a general critical soliton number is found as the compression boundary. An optimal-parameter diagram for compression at 1550 nm is presented....

  8. Synthesis of Pyridoacridines through Anionic Cascade Ring Closure

    DEFF Research Database (Denmark)

    Petersen, I.N.; Kristensen, Jesper Langgaard

    2014-01-01

    A new synthesis of 13-deazaascididemin (AK-37) based on a recently developed anionic cascade ring closure is presented. Although the isolated yields are modest, the approach provides ready access to new substituted derivatives of 13-deazaascididemin.......A new synthesis of 13-deazaascididemin (AK-37) based on a recently developed anionic cascade ring closure is presented. Although the isolated yields are modest, the approach provides ready access to new substituted derivatives of 13-deazaascididemin....

  9. Noise properties and cascadability of SOA-EA regenerators

    DEFF Research Database (Denmark)

    Öhman, Filip; Bischoff, Svend; Tromborg, Bjarne

    2002-01-01

    We suggest and analyse a new device containing concatenated pairs of semiconductor optical amplifiers (SOAs) and electroabsorption modulators (EAs). The device has regenerative properties and improves the cascadability of optical fibre links.......We suggest and analyse a new device containing concatenated pairs of semiconductor optical amplifiers (SOAs) and electroabsorption modulators (EAs). The device has regenerative properties and improves the cascadability of optical fibre links....

  10. Vortex merging and spectral cascade in two-dimensional flows

    DEFF Research Database (Denmark)

    Nielsen, A.H.; He, X.; Juul Rasmussen, J.

    1996-01-01

    The merging of two identical vortices is studied numerically using a spectral code. It is noted that the enstrophy cascade is most active on the distorted vortex boundaries, with a Kolmogorov-like spectrum E(k) approximate to k(-alpha), alpha less than or equal to 4, developed at high wave numbers....... The inverse energy cascade is completed when the vortices merge into one of larger size. (C) 1996 American Institute of Physics....

  11. Signal transduction in a covalent post-assembly modification cascade

    Science.gov (United States)

    Pilgrim, Ben S.; Roberts, Derrick A.; Lohr, Thorsten G.; Ronson, Tanya K.; Nitschke, Jonathan R.

    2017-12-01

    Natural reaction cascades control the movement of biomolecules between cellular compartments. Inspired by these systems, we report a synthetic reaction cascade employing post-assembly modification reactions to direct the partitioning of supramolecular complexes between phases. The system is composed of a self-assembled tetrazine-edged FeII8L12 cube and a maleimide-functionalized FeII4L6 tetrahedron. Norbornadiene (NBD) functions as the stimulus that triggers the cascade, beginning with the inverse-electron-demand Diels-Alder reaction of NBD with the tetrazine moieties of the cube. This reaction generates cyclopentadiene as a transient by-product, acting as a relay signal that subsequently undergoes a Diels-Alder reaction with the maleimide-functionalized tetrahedron. Cyclooctyne can selectively inhibit the cascade by outcompeting NBD as the initial trigger. Initiating the cascade with 2-octadecyl NBD leads to selective alkylation of the tetrahedron upon cascade completion. The increased lipophilicity of the C18-tagged tetrahedron drives this complex into a non-polar phase, allowing its isolation from the initially inseparable mixture of complexes.

  12. Cascade of negative muons in atoms

    International Nuclear Information System (INIS)

    Akylas, V.R.

    1978-01-01

    A study is made of the evolution of a negative muon captured in an atom and the formalism of energy loss associated with the muonic atom. The principal goals are to calculate reliability the muon x-ray intensities, given the initial population of the muonic orbits, to invert the problem and deduce the initial distribution from the x-ray intensities, to provide a reasonably simple and convenient tool to correlate observations, and finally, to systematize some questions of theoretical interest. The early part of the history of the muon in matter, including the atomic capture and classical phase of the atomic cascade are reviewed. In the quantal treatment of the transition rates, both radiative and electron Auger transitions are considered. In general, multipolarities up to E3 and K, L, and M electronic shells are fully investigated. Multipole radiation is treated in the conventinal way and pesents no special problems. Magnetic type transitions between states with different principal quantum numbers are shown to be small. Auger electron ejection rates are more complicated and several approximations have been adopted. The basic results have been computed in terms of elemetary functions. In the Auger transitions we have shown that magnetic multipoles can be safety neglected. The relative sizes of the rates corresponding to different multipoles are systematically studied. A comparison of results is made with atomic photoelectric effect data and with the nuclear internal conversion coefficients. A general agreement is found, except around shell thresholds. The existing data of muonic x-ray intensities in iron and thallium are analyzed in a systematic way. It is found that for Fe the initial l-distribution is almost flat, whereas that for T1 is weighted towards the high l values, sharper than statistical. As a result of the investigations and in order to make our findings usable, a computer program has been developed. 36 references

  13. Trophic redundancy reduces vulnerability to extinction cascades.

    Science.gov (United States)

    Sanders, Dirk; Thébault, Elisa; Kehoe, Rachel; Frank van Veen, F J

    2018-03-06

    Current species extinction rates are at unprecedentedly high levels. While human activities can be the direct cause of some extinctions, it is becoming increasingly clear that species extinctions themselves can be the cause of further extinctions, since species affect each other through the network of ecological interactions among them. There is concern that the simplification of ecosystems, due to the loss of species and ecological interactions, increases their vulnerability to such secondary extinctions. It is predicted that more complex food webs will be less vulnerable to secondary extinctions due to greater trophic redundancy that can buffer against the effects of species loss. Here, we demonstrate in a field experiment with replicated plant-insect communities, that the probability of secondary extinctions is indeed smaller in food webs that include trophic redundancy. Harvesting one species of parasitoid wasp led to secondary extinctions of other, indirectly linked, species at the same trophic level. This effect was markedly stronger in simple communities than for the same species within a more complex food web. We show that this is due to functional redundancy in the more complex food webs and confirm this mechanism with a food web simulation model by highlighting the importance of the presence and strength of trophic links providing redundancy to those links that were lost. Our results demonstrate that biodiversity loss, leading to a reduction in redundant interactions, can increase the vulnerability of ecosystems to secondary extinctions, which, when they occur, can then lead to further simplification and run-away extinction cascades. Copyright © 2018 the Author(s). Published by PNAS.

  14. Cascaded processing in written compound word production.

    Science.gov (United States)

    Bertram, Raymond; Tønnessen, Finn Egil; Strömqvist, Sven; Hyönä, Jukka; Niemi, Pekka

    2015-01-01

    In this study we investigated the intricate interplay between central linguistic processing and peripheral motor processes during typewriting. Participants had to typewrite two-constituent (noun-noun) Finnish compounds in response to picture presentation while their typing behavior was registered. As dependent measures we used writing onset time to assess what processes were completed before writing and inter-key intervals to assess what processes were going on during writing. It was found that writing onset time was determined by whole word frequency rather than constituent frequencies, indicating that compound words are retrieved as whole orthographic units before writing is initiated. In addition, we found that the length of the first syllable also affects writing onset time, indicating that the first syllable is fully prepared before writing commences. The inter-key interval results showed that linguistic planning is not fully ready before writing, but cascades into the motor execution phase. More specifically, inter-key intervals were largest at syllable and morpheme boundaries, supporting the view that additional linguistic planning takes place at these boundaries. Bigram and trigram frequency also affected inter-key intervals with shorter intervals corresponding to higher frequencies. This can be explained by stronger memory traces for frequently co-occurring letter sequences in the motor memory for typewriting. These frequency effects were even larger in the second than in the first constituent, indicating that low-level motor memory starts to become more important during the course of writing compound words. We discuss our results in the light of current models of morphological processing and written word production.

  15. Cascade screening program for familial hypercholesterolemia.

    Science.gov (United States)

    Rubio-Marín, Patricia; Michán-Doña, Alfredo; Maraver-Delgado, Juan; Arroyo-Olivares, Raquel; Barrado Varea, Rosalía; Pérez de Isla, Leopoldo; Mata, Pedro

    2018-03-06

    Early detection of heterozygous familial hypercholesterolemia (HFH) is needed to prevent premature cardiovascular events. Our aim isto describe the course of an HFH screening detection day in the Northern Cadiz Health Area in Spain and to analyze the data recorded. Descriptive study of an FH cascade screening program. Index cases (ICs) and their 1st and 2nd grade relatives were appointed during a weekend by the FH Foundation. Venous blood samples were taken from the subjects for genetic, blood, and chemistry tests; specialized medical consultation and physical examination were performed. The study sample consisted of 132 subjects: 21 ICs and 111 relatives (16 under 18years old), with a mean age of 11.4years (SD4.57). Mean age of subjects over 18years was 45.2years. A gene mutation was found in 90 relatives. Mean age at diagnosis was 25years (SD17.7) for relatives and for 36.4years (SD17.2; P=.01) for ICs. Smoking rate was higher in relatives than in ICs (26.3% vs 4.8%; P=.02) and corneal arcus was more common in ICs as compared to relatives (47.6% vs 12.6%; P<.001). Prior myocardial infarction was recorded in 14.3% of ICs and 4.2% of relatives respectively (P=.07). Maximum lipid lowering treatment was being administered to 43.1%. The screening detection approach identified the estimated 4% population with HFH in the area, and allows for diagnosing HFH 11.4years earlier. Copyright © 2018 SEEN y SED. Publicado por Elsevier España, S.L.U. All rights reserved.

  16. Cascaded Subpatch Networks for Effective CNNs.

    Science.gov (United States)

    Jiang, Xiaoheng; Pang, Yanwei; Sun, Manli; Li, Xuelong

    2017-05-12

    Conventional convolutional neural networks use either a linear or a nonlinear filter to extract features from an image patch (region) of spatial size Hx W (typically, H is small and is equal to W, e.g., H is 5 or 7 ). Generally, the size of the filter is equal to the size Hx W of the input patch. We argue that the representational ability of equal-size strategy is not strong enough. To overcome the drawback, we propose to use subpatch filter whose spatial size hx w is smaller than Hx W . The proposed subpatch filter consists of two subsequent filters. The first one is a linear filter of spatial size hx w and is aimed at extracting features from spatial domain. The second one is of spatial size 1x 1 and is used for strengthening the connection between different input feature channels and for reducing the number of parameters. The subpatch filter convolves with the input patch and the resulting network is called a subpatch network. Taking the output of one subpatch network as input, we further repeat constructing subpatch networks until the output contains only one neuron in spatial domain. These subpatch networks form a new network called the cascaded subpatch network (CSNet). The feature layer generated by CSNet is called the csconv layer. For the whole input image, we construct a deep neural network by stacking a sequence of csconv layers. Experimental results on five benchmark data sets demonstrate the effectiveness and compactness of the proposed CSNet. For example, our CSNet reaches a test error of 5.68% on the CIFAR10 data set without model averaging. To the best of our knowledge, this is the best result ever obtained on the CIFAR10 data set.

  17. MOLECULAR DYNAMICS SIMULATIONS OF DISPLACEMENT CASCADES IN MOLYBDENUM

    International Nuclear Information System (INIS)

    Smith, Richard Whiting

    2003-01-01

    Molecular dynamics calculations have been employed to simulate displacement cascades in neutron irradiated Mo. A total of 90 simulations were conducted for PKA energies between 1 and 40 keV and temperatures from 298 to 923K. The results suggest very little effect of temperature on final defect count and configuration, but do display a temperature effect on peak defect generation prior to cascade collapse. Cascade efficiency, relative to the NRT model, is computed to lie between 1/4 and 1/3 in agreement with simulations performed on previous systems. There is a tendency for both interstitials and vacancies to cluster together following cascade collapse producing vacancy rich regions surrounded by interstitials. Although coming to rest in close proximity, the point defects comprising the clusters generally do not lie within the nearest neighbor positions of one another, except for the formation of dumbbell di-interstitials. Cascades produced at higher PKA energies (20 or 40 keV) exhibit the formation of subcascades

  18. Cascades and Dissipative Anomalies in Compressible Fluid Turbulence

    Science.gov (United States)

    Eyink, Gregory L.; Drivas, Theodore D.

    2018-02-01

    We investigate dissipative anomalies in a turbulent fluid governed by the compressible Navier-Stokes equation. We follow an exact approach pioneered by Onsager, which we explain as a nonperturbative application of the principle of renormalization-group invariance. In the limit of high Reynolds and Péclet numbers, the flow realizations are found to be described as distributional or "coarse-grained" solutions of the compressible Euler equations, with standard conservation laws broken by turbulent anomalies. The anomalous dissipation of kinetic energy is shown to be due not only to local cascade but also to a distinct mechanism called pressure-work defect. Irreversible heating in stationary, planar shocks with an ideal-gas equation of state exemplifies the second mechanism. Entropy conservation anomalies are also found to occur via two mechanisms: an anomalous input of negative entropy (negentropy) by pressure work and a cascade of negentropy to small scales. We derive "4 /5 th-law"-type expressions for the anomalies, which allow us to characterize the singularities (structure-function scaling exponents) required to sustain the cascades. We compare our approach with alternative theories and empirical evidence. It is argued that the "Big Power Law in the Sky" observed in electron density scintillations in the interstellar medium is a manifestation of a forward negentropy cascade or an inverse cascade of usual thermodynamic entropy.

  19. Efficiency criteria for optimization of separation cascades for uranium enrichment

    Directory of Open Access Journals (Sweden)

    Georgy Sulaberidze

    2018-02-01

    Full Text Available As it is known, uranium enrichment is carried out on industrial scale by means of multistage separation facilities, i.e., separation cascades in which gas centrifuges (GCs are connected in series and parallel. Design and construction of these facilities require significant investment. So, the problem of calculation and optimization of cascade working parameters is still relevant today. At the same time, in many cases, the minimum unit cost of a product is related to the cascade having the smallest possible number of separation elements/GCs. Also, in theoretical studies, it is often acceptable to apply as an efficiency criterion the minimum total flow to supply cascade stages instead of the abovementioned minimum unit cost or the number of separation elements. In this article, cascades with working parameter of a single GC changing from stage to stage are optimized by two of the abovementioned performance criteria and are compared. The results obtained allow us to make a conclusion about their differences.

  20. INCAS: an analytical model to describe displacement cascades

    International Nuclear Information System (INIS)

    Jumel, Stephanie; Claude Van-Duysen, Jean

    2004-01-01

    REVE (REactor for Virtual Experiments) is an international project aimed at developing tools to simulate neutron irradiation effects in Light Water Reactor materials (Fe, Ni or Zr-based alloys). One of the important steps of the project is to characterise the displacement cascades induced by neutrons. Accordingly, the Department of Material Studies of Electricite de France developed an analytical model based on the binary collision approximation. This model, called INCAS (INtegration of CAScades), was devised to be applied on pure elements; however, it can also be used on diluted alloys (reactor pressure vessel steels, etc.) or alloys composed of atoms with close atomic numbers (stainless steels, etc.). INCAS describes displacement cascades by taking into account the nuclear collisions and electronic interactions undergone by the moving atoms. In particular, it enables to determine the mean number of sub-cascades induced by a PKA (depending on its energy) as well as the mean energy dissipated in each of them. The experimental validation of INCAS requires a large effort and could not be carried out in the framework of the study. However, it was verified that INCAS results are in conformity with those obtained from other approaches. As a first application, INCAS was applied to determine the sub-cascade spectrum induced in iron by the neutron spectrum corresponding to the central channel of the High Flux Irradiation Reactor of Oak Ridge National Laboratory

  1. Positional information generated by spatially distributed signaling cascades.

    Directory of Open Access Journals (Sweden)

    Javier Muñoz-García

    2009-03-01

    Full Text Available The temporal and stationary behavior of protein modification cascades has been extensively studied, yet little is known about the spatial aspects of signal propagation. We have previously shown that the spatial separation of opposing enzymes, such as a kinase and a phosphatase, creates signaling activity gradients. Here we show under what conditions signals stall in the space or robustly propagate through spatially distributed signaling cascades. Robust signal propagation results in activity gradients with long plateaus, which abruptly decay at successive spatial locations. We derive an approximate analytical solution that relates the maximal amplitude and propagation length of each activation profile with the cascade level, protein diffusivity, and the ratio of the opposing enzyme activities. The control of the spatial signal propagation appears to be very different from the control of transient temporal responses for spatially homogenous cascades. For spatially distributed cascades where activating and deactivating enzymes operate far from saturation, the ratio of the opposing enzyme activities is shown to be a key parameter controlling signal propagation. The signaling gradients characteristic for robust signal propagation exemplify a pattern formation mechanism that generates precise spatial guidance for multiple cellular processes and conveys information about the cell size to the nucleus.

  2. Cascades and Dissipative Anomalies in Compressible Fluid Turbulence

    Directory of Open Access Journals (Sweden)

    Gregory L. Eyink

    2018-02-01

    Full Text Available We investigate dissipative anomalies in a turbulent fluid governed by the compressible Navier-Stokes equation. We follow an exact approach pioneered by Onsager, which we explain as a nonperturbative application of the principle of renormalization-group invariance. In the limit of high Reynolds and Péclet numbers, the flow realizations are found to be described as distributional or “coarse-grained” solutions of the compressible Euler equations, with standard conservation laws broken by turbulent anomalies. The anomalous dissipation of kinetic energy is shown to be due not only to local cascade but also to a distinct mechanism called pressure-work defect. Irreversible heating in stationary, planar shocks with an ideal-gas equation of state exemplifies the second mechanism. Entropy conservation anomalies are also found to occur via two mechanisms: an anomalous input of negative entropy (negentropy by pressure work and a cascade of negentropy to small scales. We derive “4/5th-law”-type expressions for the anomalies, which allow us to characterize the singularities (structure-function scaling exponents required to sustain the cascades. We compare our approach with alternative theories and empirical evidence. It is argued that the “Big Power Law in the Sky” observed in electron density scintillations in the interstellar medium is a manifestation of a forward negentropy cascade or an inverse cascade of usual thermodynamic entropy.

  3. Bearing-Only Formation Control for Cascade Multirobots

    Directory of Open Access Journals (Sweden)

    Qing Han

    2016-01-01

    Full Text Available A new formation control method is proposed, which is used to queue multirobots in a single-direction cascade structure. In the cascade formation, each robot is a follower for the previous robot and a leader for the next robot, and the robots in the middle act as both leader and follower. The follower robot can only observe the bearing information of the leader robot. The observability of the cascade leader-follower formation is studied, which shows that the bearing-only observation meets the observability conditions required for the nonlinear system. Based on the bearing-only observations, the unscented Kalman filter (UKF is employed for the state estimation of the leader and the follower robots at all levels, which enables the real-time movement control of the follower robots via the input-output feedback control. Simulation results demonstrate that the proposed approach can efficiently control the formation of multirobots as desired.

  4. Cascade: a review of heat transport and plant design issues

    International Nuclear Information System (INIS)

    Murray, K.A.; McDowell, M.W.

    1984-01-01

    A conceptual heat transfer loop for Cascade, a centrifugal-action solid-breeder reaction chamber, has been investigated and results are presented. The Cascade concept, a double-cone-shaped reaction chamber, rotates along its horizontal axis. Solid Li 2 O or other lithium-ceramic granules are injected tangentially through each end of the chamber. The granules cascade axially from the smaller radii at the ends to the larger radius at the center, where they are ejected into a stationary granule catcher. Heat and tritium are then removed from the granules and the granules are reinjected into the chamber. A 50% dense Li 2 O granule throughput of 2.8 m 3 /s is transferred from the reaction chamber to the steam generators via continuous bucket elevators. The granules then fall by gravity through 4 vertical steam generators. The entire transport system is maintained at the same vacuum conditions present inside the reaction chamber

  5. Substrate-driven chemotactic assembly in an enzyme cascade

    Science.gov (United States)

    Zhao, Xi; Palacci, Henri; Yadav, Vinita; Spiering, Michelle M.; Gilson, Michael K.; Butler, Peter J.; Hess, Henry; Benkovic, Stephen J.; Sen, Ayusman

    2018-03-01

    Enzymatic catalysis is essential to cell survival. In many instances, enzymes that participate in reaction cascades have been shown to assemble into metabolons in response to the presence of the substrate for the first enzyme. However, what triggers metabolon formation has remained an open question. Through a combination of theory and experiments, we show that enzymes in a cascade can assemble via chemotaxis. We apply microfluidic and fluorescent spectroscopy techniques to study the coordinated movement of the first four enzymes of the glycolysis cascade: hexokinase, phosphoglucose isomerase, phosphofructokinase and aldolase. We show that each enzyme independently follows its own specific substrate gradient, which in turn is produced by the preceding enzymatic reaction. Furthermore, we find that the chemotactic assembly of enzymes occurs even under cytosolic crowding conditions.

  6. The performance of pip-cascade controler in HVAC system

    Directory of Open Access Journals (Sweden)

    Legweel Khaled M.B.

    2014-01-01

    Full Text Available Primitive controllers used in the early version for HVAC systems, like the on-off (Bang-Bang controller, are inefficient, inaccurate, unstable, and suffer from high-level mechanical wear. On the other hand, other controllers like PI and cascade controllers, overcome these disadvantages but when an offset response (inaccurate response occurs, power consumption will increase. In order to acquire better performance in the central air-conditioning system, PIP-cascade control is investigated in this paper and compared to the traditional PI and PID, in simulation of experimental data. The output of the system is predicted through disturbances. Based on the mathematical model of air-conditioning space, the simulations in this paper have found that the PIP-cascade controller has the capability of self-adapting to system changes and results in faster response and better performance.

  7. Vortex annihilation and inverse cascades in two dimensional superfluid turbulence

    Science.gov (United States)

    Lucas, Andrew; Chesler, Paul M.

    2015-03-01

    The dynamics of a dilute mixture of vortices and antivortices in a turbulent two-dimensional superfluid at finite temperature is well described by first order Hall-Vinen-Iordanskii equations, or dissipative point vortex dynamics. These equations are governed by a single dimensionless parameter: the ratio of the strength of drag forces to Magnus forces on vortices. When this parameter is small, we demonstrate using numerical simulations that the resulting superfluid enjoys an inverse energy cascade where small scale stirring leads to large scale vortex clustering. We argue analytically and numerically that the vortex annihilation rate in a laminar flow may be parametrically smaller than the rate in a turbulent flow with an inverse cascade. This suggests a new way to detect inverse cascades in experiments on two-dimensional superfluid turbulence using cold atomic gases, where traditional probes of turbulence such as the energy spectrum are not currently accessible.

  8. Optimization Control of Bidirectional Cascaded DC-AC Converter Systems

    DEFF Research Database (Denmark)

    Tian, Yanjun

    in bidirectional cascaded converter. This research work analyses the control strategies based on the topology of dual active bridges converter cascaded with a three phase inverter. It firstly proposed a dc link voltage and active power coordinative control method for this cascaded topology, and it can reduce dc....... The connections of the renewable energy sources to the power system are mostly through the power electronic converters. Moreover, for high controllability and flexibility, power electronic devices are gradually acting as the interface between different networks in power systems, promoting conventional power...... the bidirectional power flow in the distribution level of power systems. Therefore direct contact of converters introduces significant uncertainties to power system, especially for the stability and reliability. This dissertation studies the optimization control of the two stages directly connected converters...

  9. Investigation of cascade effect failure for tungsten armour

    International Nuclear Information System (INIS)

    Makhankov, A.; Barabash, V.; Berkhov, N.; Divavin, V.; Giniatullin, R.; Grigoriev, S.; Ibbott, C.; Komarov, V.; Labusov, A.; Mazul, I.; McDonald, J.; Tanchuk, V.; Youchison, D.

    2001-01-01

    The glancing angle of incident power on the target of a tokamak divertor results in doubled and highly peaked heat flux onto adjacent downstream tile in the case of lost of tile event (LOTE). As a result downstream tile has higher probability to fail resulting in triple loads to the next downstream tile and so on (cascade effect). This paper devoted to analytical and experimental investigation of the cascade effect failure for the flat tile option of tungsten armoured plasma facing components. Armour geometry resistant to the cascade effect failure was selected on the base of thermal and stress analyses. Experimental investigation of the LOTE has been performed also. Small size W/Cu mock-up withstood not only LOTE simulation load, but also survived afterwards for 1500 cycles at 26-28 MW/m 2 without damage in joint

  10. A Cascade-Based Emergency Model for Water Distribution Network

    Directory of Open Access Journals (Sweden)

    Qing Shuang

    2015-01-01

    Full Text Available Water distribution network is important in the critical physical infrastructure systems. The paper studies the emergency resource strategies on water distribution network with the approach of complex network and cascading failures. The model of cascade-based emergency for water distribution network is built. The cascade-based model considers the network topology analysis and hydraulic analysis to provide a more realistic result. A load redistribution function with emergency recovery mechanisms is established. From the aspects of uniform distribution, node betweenness, and node pressure, six recovery strategies are given to reflect the network topology and the failure information, respectively. The recovery strategies are evaluated with the complex network indicators to describe the failure scale and failure velocity. The proposed method is applied by an illustrative example. The results showed that the recovery strategy considering the node pressure can enhance the network robustness effectively. Besides, this strategy can reduce the failure nodes and generate the least failure nodes per time.

  11. Performance validation of a cascade control system through

    Directory of Open Access Journals (Sweden)

    A. Lakshmi Sangeetha

    2016-11-01

    Full Text Available The work analyzes the performance characteristics of a cascade control system when interconnected with various network architectures, such as Internet, mobile and wireless networks. The cascade control system consists of level and flow as primary and secondary variables, respectively. The web-enabled monitoring and control are realized using three techniques namely remote client–server, ActiveX-data socket and web publishing tool. Mobile network is established by interfacing the control system with a GSM modem which enables the monitoring of process parameters through mobile phones. The cascade control system is also monitored wirelessly from remote locations with advent of an indigenous wireless sensor node. The performance analysis proved that wireless monitoring may be considered as an effective alternate technique to the Internet-based communication especially for shorter distances.

  12. Node vulnerability of water distribution networks under cascading failures

    International Nuclear Information System (INIS)

    Shuang, Qing; Zhang, Mingyuan; Yuan, Yongbo

    2014-01-01

    Water distribution networks (WDNs) are important in modern lifeline system. Its stability and reliability are critical for guaranteeing high living quality and continuous operation of urban functions. The aim of this paper is to evaluate the nodal vulnerability of WDNs under cascading failures. Vulnerability is defined to analyze the effects of the consequent failures. A cascading failure is a step-by-step process which is quantitatively investigated by numerical simulation with intentional attack. Monitored pressures in different nodes and flows in different pipes have been used to estimate the network topological structure and the consequences of nodal failure. Based on the connectivity loss of topological structure, the nodal vulnerability has been evaluated. A load variation function is established to record the nodal failure reason and describe the relative differences between the load and the capacity. The proposed method is validated by an illustrative example. The results revealed that the network vulnerability should be evaluated with the consideration of hydraulic analysis and network topology. In the case study, 70.59% of the node failures trigger the cascading failures with different failure processes. It is shown that the cascading failures result in severe consequences in WDNs. - Highlights: • The aim of this paper is to evaluate the nodal vulnerability of water distribution networks under cascading failures. • Monitored pressures and flows have been used to estimate the network topological structure and the consequences of nodal failure. • Based on the connectivity loss of topological structure, the nodal vulnerability has been evaluated. • A load variation function is established to record the failure reason and describe the relative differences between load and capacity. • The results show that 70.59% of the node failures trigger the cascading failures with different failure processes

  13. PULSE MODULATION POWER AMPLIFIER WITH ENHANCED CASCADE CONTROL METHOD

    DEFF Research Database (Denmark)

    1998-01-01

    A digital switching power amplifier with Multivariable Enhanced Cascade Controlled (MECC) includes a modulator, a switching power stage and a low pass filter. In the first preferred embodiment an enhanced cascade control structure local to the switching power stage is added, characterised by havi...... and feedback path A to determine stable self-oscillating conditions. An implemented 250W example MECC digital power amplifier has proven superior performance in terms of audio performance (0.005 % distortion, 115 dB dynamic range) and efficiency (92 %)....

  14. General introduction to microstructural evolution under cascade damage conditions

    International Nuclear Information System (INIS)

    Wiedersich, H.

    1993-06-01

    A short overview of the processes that affect the evolution of the microstructure during irradiation is given. The processes include defect production with an emphasis on the effects of the dynamic cascade events, defect clustering, irradiation-enhanced diffusion, radiation-induced segregation, phase decompositions and phase transformations. A simple model for the description of the development of the defect microstructure in a pure metal during cascade producing irradiation is also outlined which can provide, in principle, defect fluxes required for the description of the microstructural processes such as phase decomposition and irradiation-induced precipitation

  15. General introduction to microstructural evolution under cascade damage conditions

    Energy Technology Data Exchange (ETDEWEB)

    Wiedersich, H.

    1993-06-01

    A short overview of the processes that affect the evolution of the microstructure during irradiation is given. The processes include defect production with an emphasis on the effects of the dynamic cascade events, defect clustering, irradiation-enhanced diffusion, radiation-induced segregation, phase decompositions and phase transformations. A simple model for the description of the development of the defect microstructure in a pure metal during cascade producing irradiation is also outlined which can provide, in principle, defect fluxes required for the description of the microstructural processes such as phase decomposition and irradiation-induced precipitation.

  16. Limits to compression with cascaded quadratic soliton compressors

    DEFF Research Database (Denmark)

    Bache, Morten; Bang, Ole; Krolikowski, Wieslaw

    2008-01-01

    We study cascaded quadratic soliton compressors and address the physical mechanisms that limit the compression. A nonlocal model is derived, and the nonlocal response is shown to have an additional oscillatory component in the nonstationary regime when the group-velocity mismatch (GVM) is strong....... This inhibits efficient compression. Raman-like perturbations from the cascaded nonlinearity, competing cubic nonlinearities, higher-order dispersion, and soliton energy may also limit compression, and through realistic numerical simulations we point out when each factor becomes important. We find...

  17. Modeling of Bit Error Rate in Cascaded 2R Regenerators

    DEFF Research Database (Denmark)

    Öhman, Filip; Mørk, Jesper

    2006-01-01

    This paper presents a simple and efficient model for estimating the bit error rate in a cascade of optical 2R-regenerators. The model includes the influences of of amplifier noise, finite extinction ratio and nonlinear reshaping. The interplay between the different signal impairments and the rege......This paper presents a simple and efficient model for estimating the bit error rate in a cascade of optical 2R-regenerators. The model includes the influences of of amplifier noise, finite extinction ratio and nonlinear reshaping. The interplay between the different signal impairments...

  18. Fast perceptual image hash based on cascade algorithm

    Science.gov (United States)

    Ruchay, Alexey; Kober, Vitaly; Yavtushenko, Evgeniya

    2017-09-01

    In this paper, we propose a perceptual image hash algorithm based on cascade algorithm, which can be applied in image authentication, retrieval, and indexing. Image perceptual hash uses for image retrieval in sense of human perception against distortions caused by compression, noise, common signal processing and geometrical modifications. The main disadvantage of perceptual hash is high time expenses. In the proposed cascade algorithm of image retrieval initializes with short hashes, and then a full hash is applied to the processed results. Computer simulation results show that the proposed hash algorithm yields a good performance in terms of robustness, discriminability, and time expenses.

  19. Special Issue ;Sediment cascades in cold climate geosystems;

    Science.gov (United States)

    Morche, David; Krautblatter, Michael; Beylich, Achim A.

    2017-06-01

    This Editorial introduces the Special Issue on sediment cascades in cold climate geosystems that evolved from the eighth I.A.G./A.I.G. SEDIBUD (Sediment Budgets in Cold Environments; http://www.geomorph.org/sedibud-working-group/) workshop. The workshop was held from 1st to 4th September 2014 at the Environmental Research Station ;Schneefernerhaus; (http://www.schneefernerhaus.de/en/home.html) located at Mt. Zugspitze, the highest peak of Germany, (2962 m asl). Paper and poster presentations focused on observations, measurements and modeling of geomorphological processes in sediment cascades in cold climate geosystems. This resulting Special Issue brings together ten selected contributions from arctic and alpine environments.

  20. Numerical modelling of compressible viscous flow in turbine cascades

    Science.gov (United States)

    Louda, P.; Kozel, K.; Příhoda, J.

    2014-03-01

    The work deals with mathematical models of turbulent flow through turbine cascade in 2D and 3D. It is based on the Favre-averaged Navier-Stokes equations with SST or EARSM turbulence models. A two-equation model of transition to turbulence is considered too. The solution is obtained by implicit AUSM finite volume method. The 2D and 3D results are shown flow through the SE1050 cascade including simulation of a range of off-design angles of attack.

  1. On the trajectories of CRL...LR...R orbits, their period-doubling cascades and saddle-node bifurcation cascades

    International Nuclear Information System (INIS)

    Cerrada, Lucia; San Martin, Jesus

    2011-01-01

    In this Letter, it is shown that from a two region partition of the phase space of a one-dimensional dynamical system, a p-region partition can be obtained for the CRL...LR...R orbits. That is, permutations associated with symbolic sequences are obtained. As a consequence, the trajectory in phase space is directly deduced from permutation. From this permutation other permutations associated with period-doubling and saddle-node bifurcation cascades are derived, as well as other composite permutations. - Research highlights: → Symbolic sequences are the usual topological approach to dynamical systems. → Permutations bear more physical information than symbolic sequences. → Period-doubling cascade permutations associated with original sequences are obtained. → Saddle-node cascade permutations associated with original sequences are obtained. → Composite permutations are derived.

  2. Interrelation of structure and operational states in cascading failure of overloading lines in power grids

    Science.gov (United States)

    Xue, Fei; Bompard, Ettore; Huang, Tao; Jiang, Lin; Lu, Shaofeng; Zhu, Huaiying

    2017-09-01

    As the modern power system is expected to develop to a more intelligent and efficient version, i.e. the smart grid, or to be the central backbone of energy internet for free energy interactions, security concerns related to cascading failures have been raised with consideration of catastrophic results. The researches of topological analysis based on complex networks have made great contributions in revealing structural vulnerabilities of power grids including cascading failure analysis. However, existing literature with inappropriate assumptions in modeling still cannot distinguish the effects between the structure and operational state to give meaningful guidance for system operation. This paper is to reveal the interrelation between network structure and operational states in cascading failure and give quantitative evaluation by integrating both perspectives. For structure analysis, cascading paths will be identified by extended betweenness and quantitatively described by cascading drop and cascading gradient. Furthermore, the operational state for cascading paths will be described by loading level. Then, the risk of cascading failure along a specific cascading path can be quantitatively evaluated considering these two factors. The maximum cascading gradient of all possible cascading paths can be used as an overall metric to evaluate the entire power grid for its features related to cascading failure. The proposed method is tested and verified on IEEE30-bus system and IEEE118-bus system, simulation evidences presented in this paper suggests that the proposed model can identify the structural causes for cascading failure and is promising to give meaningful guidance for the protection of system operation in the future.

  3. Numerical optimization of a transcritical CO2/propylene cascaded ...

    Indian Academy of Sciences (India)

    Use of organic refrigerants such as Hydrochlorofluorocarbons and Chlorofluorocarbons have been criticized for their adverse impact on the Earth's protective ozone layer and for their significant global warming potential (GWP). CO2 has been receiving great concern as an alternative refrigerant. Cascade refrigeration ...

  4. Gamma irradiation of Fabry–Perot interband cascade lasers

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Tanya L. [Pacific Northwest National Laboratory, Richland, Washington; Cannon, Bret D. [Pacific Northwest National Laboratory, Richland, Washington; Brauer, Carolyn S. [Pacific Northwest National Laboratory, Richland, Washington; Canedy, Chadwick L. [Naval Research Laboratory, Washington, DC; Kim, Chul Soo [Naval Research Laboratory, Washington, DC; Kim, Mijin [Sotera Defense Solutions, Inc., Columbia, Maryland; Merritt, Charles D. [Naval Research Laboratory, Washington, DC; Bewley, William W. [Naval Research Laboratory, Washington, DC; Vurgaftman, Igor [Naval Research Laboratory, Washington, DC; Meyer, Jerry R. [Naval Research Laboratory, Washington, DC

    2017-09-20

    Two Fabry-Perot interband cascade lasers (ICLs) were exposed to Cobalt-60 gamma rays for a dosage of 500 krad(Si) each, which is higher than is typically encountered in space applications. The ICLs do not show any significant changes in threshold current or slope efficiency, suggesting the suitability of ICLs for use in radiation environments.

  5. Probing supersymmetry with third-generation cascade decays

    Energy Technology Data Exchange (ETDEWEB)

    Graesser, Michael [Los Alamos National Laboratory; Shelton, Jessie [RUTGERS UNIV

    2008-01-01

    The chiral structure of supersymmetric particle couplings involving third generation Standard Model fermions depends on left-right squark and slepton mixings as well as gaugino-higgsino mixings. The shapes and intercorrelations of invariant mass distributions of a first or second generation lepton with bottoms and taus arising from adjacent branches of SUSY cascade decays are shown to be a sensitive probe of this chiral structure. All possible cascade decays that can give rise to such correlations within the MSSM are considered. For bottom-lepton correlations the distinctive structure of the invariant mass distributions distinguishes between decays originating from stop or sbottom squarks through either an intermediate chargino or neutralino. For decay through a chargino the spins of the stop and chargino are established by the form of the distribution. When the bottom charge is signed through soft muon tagging, the structure of the same-sign and opposite-sign invariant mass distributions depends on a set function of left-right and gaugino-higgsino mixings, as well as establishes the spins of all the superpartners in the sequential two-body cascade decay. Tau-lepton and tau-tau invariant mass distributions arising from MSSM cascade decays are likewise systematically considered with particular attention to their dependence on tau polarization. All possible tau-lepton and tau-tau distributions are plotted using a semi-analytic model for hadronic one-prong taus. Algorithms for fitting tau-tau and tau-lepton distributions to data are suggested.

  6. ECG classification and abnormality detection using cascade forward ...

    African Journals Online (AJOL)

    user

    Keywords: Arrhythmia, MATLAB, Artificial Neural Networks, Back propagation, Cascade- Forward Network, MIT-BIH arrhythmia ... and prominent among them is the use of Artificial Neural Networks (Zurada, 1999) which has given promising results to such ..... and uses the artificial intelligence techniques in her research.

  7. A nine-level hybrid symmetric cascaded multilevel converter for ...

    Indian Academy of Sciences (India)

    Indrajit Sarkar

    To address these limitations, a nine-level hybrid sym- metric cascaded converter using one five-level and one three-level HB power cell per phase is proposed in this work for induction motor drive applications. The features of proposed configuration are as follows: (a) increase in output voltage levels to nearly double of that ...

  8. Numerical optimization of a transcritical CO2/propylene cascaded ...

    Indian Academy of Sciences (India)

    liquefaction of petroleum vapors and natural gas, manufacturing of dry ice, precipitation hard- ening of special alloy ..... vement of a transcritical CO2 cycle by using piston–cylinder work producing expansion device. Groll et al ... (v) Heat transfer processes in cascade heat exchanger, evaporator, economizer and gas cooler.

  9. A network approach for power grid robustness against cascading failures

    NARCIS (Netherlands)

    Wang, X.; Koc, Y.; Kooij, R.E.; Van Mieghem, P.

    2015-01-01

    Cascading failures are one of the main reasons for blackouts in electrical power grids. Stable power supply requires a robust design of the power grid topology. Currently, the impact of the grid structure on the grid robustness is mainly assessed by purely topological metrics, that fail to capture

  10. Cascading pressure reactor and method for solar-thermochemical reactions

    Science.gov (United States)

    Ermanoski, Ivan

    2017-11-14

    Reactors and methods for solar thermochemical reactions are disclosed. The reactors and methods include a cascade of reduction chambers at successively lower pressures that leads to over an order of magnitude pressure decrease compared to a single-chambered design. The resulting efficiency gains are substantial, and represent an important step toward practical and efficient solar fuel production on a large scale.

  11. Exciton management in organic photovoltaic multidonor energy cascades.

    Science.gov (United States)

    Griffith, Olga L; Forrest, Stephen R

    2014-05-14

    Multilayer donor regions in organic photovoltaics show improved power conversion efficiency when arranged in decreasing exciton energy order from the anode to the acceptor interface. These so-called "energy cascades" drive exciton transfer from the anode to the dissociating interface while reducing exciton quenching and allowing improved overlap with the solar spectrum. Here we investigate the relative importance of exciton transfer and blocking in a donor cascade employing diphenyltetracene (D1), rubrene (D2), and tetraphenyldibenzoperiflanthene (D3) whose optical gaps monotonically decrease from D1 to D3. In this structure, D1 blocks excitons from quenching at the anode, D2 accepts transfer of excitons from D1 and blocks excitons at the interface between D2 and D3, and D3 contributes the most to the photocurrent due to its strong absorption at visible wavelengths, while also determining the open circuit voltage. We observe singlet exciton Förster transfer from D1 to D2 to D3 consistent with cascade operation. The power conversion efficiency of the optimized cascade OPV with a C60 acceptor layer is 7.1 ± 0.4%, which is significantly higher than bilayer devices made with only the individual donors. We develop a quantitative model to identify the dominant exciton processes that govern the photocurrent generation in multilayer organic structures.

  12. Efficient cascade multiple heterojunction organic solar cells with inverted structure

    Science.gov (United States)

    Guo, Tingting; Li, Mingtao; Qiao, Zhenfang; Yu, Leiming; Zhao, Jianhong; Feng, Nianjun; Shi, Peiguang; Wang, Xiaoyan; Pu, Xiaoyun; Wang, Hai

    2018-05-01

    In this work, we demonstrate an efficient cascade multiple heterojunction organic solar cell with inverted structure. By using two donor materials, poly(3-hexylthiosphene) (P3HT) and titanyl phthalocyanine (TiOPc), as well as two acceptor materials, [6,6]-phenyl C61 butyric acid methyl ester (PCBM) and C60, the cascade multiple heterojunctions of P3HT:PCBM/TiOPc:C60/C60 have been constructed. Applying the optimized inverted configuration of FTO/Zinc Tin Oxide (ZTO)/C60 (30 nm)/TiOPc:C60 (1:1.5, 25 nm)/P3HT:PCBM (1:0.8, 100 nm)/MoO3 (4 nm)/Ag, the considerably enhanced open circuit voltage (VOC) and short circuit current (JSC) can be harvested together, and the power conversion efficiency (PCE) is three times higher than that of the control cell with conventional structure. The significant improvements of the inverted cell are mostly due to the broadened spectral absorption and high efficient multi-interface exciton dissociation in the cascade multiple heterojunctions, indicating that the optimized cascade heterojunctions match the inverted structure well.

  13. Aspects of microstructure evolution under cascade damage conditions

    DEFF Research Database (Denmark)

    Singh, B.N.; Golubov, S.I.; Trinkaus, H.

    1997-01-01

    in the cascades. Recently, it has been suggested that the problem can be treated in terms of 'production bias' and one-dimensional glide of small SIA clusters. In the earlier treatments a 'mean size approximation' was used for the defect clusters and cavities evolving during irradiation. In the present work, we...

  14. Neutron spallation source and the Dubna Cascade Code

    Indian Academy of Sciences (India)

    nuclear cascade and includes all those ... by numerous elastic nuclear collisions up to a very low energy. At the same time in. 470 ..... in table 6 that at low incident energy, major heat contribution comes from the ionization process. For example, it ...

  15. Successful Treatment Of Homozygous Familial Hypercholesterolemia Using Cascade Filtration Plasmapheresis

    Directory of Open Access Journals (Sweden)

    Fatih Kardas

    2012-12-01

    Full Text Available OBJECTIVE: The aim of our study is to discuss the efficacy of low-density lipoprotein-cholesterol (LDL-C apheresis procedure using the cascade filtration system for pediatric patients with homozygous familial hypercholesterolemia (FH, and to clarify the adverse effects and difficulties. METHODS: LDL apheresis using the cascade filtration system was performed in 3 pediatric patients with homozygous FH. In total, 120 apheresis sessions were performed for all patients. RESULTS: Cascade filtration therapy significantly reduced the mean LDL-C values from 418 ± 62 mg/dl to 145 ± 43 mg/dl (p<0.05. We determined an acute mean reduction in the plasma levels of total cholesterol (57.9%, LDL cholesterol (70.8%, and high-density lipoprotein (HDL cholesterol (40.7%. Treatments were well tolerated. The most frequent clinical adverse effects were hypotension in 3 sessions (2.5%, chills/feeling cold (1.7% in 2 sessions, and nausea and vomiting in 3 sessions (2.5%. CONCLUSION: Our experience with three patients using the cascade filtration system were, good clinical outcomes, laboratory findings, safety of usage, minor adverse effects and technical problems.

  16. Dispersive waves in fs cascaded second-harmonic generation

    DEFF Research Database (Denmark)

    Bache, Morten; Bang, Ole; Krolikowski, Wieslaw

    2009-01-01

    Dispersive waves are observed in simulations of cascaded (phase-mismatched) second-harmonic generation. When generating ultra-short fs compressed near-IR solitons the dispersive waves are strongly red-shifted, depending on the soliton wavelength. Semi-analytical calculations predict the wavelengths....

  17. Checklist of vertebrate animals of the Cascade Head Experimental Forest.

    Science.gov (United States)

    Chris Maser; Jerry F. Franklin

    1974-01-01

    Three months, April and August 1971 and August 1972, were spent studying the vertebrate fauna of Cascade Head Experimental Forest. The resulting annotated checklist includes 9 amphibians, 2 reptiles, 35 birds, and 40 mammals. A standardized animal habitat classification is presented in an effort to correlate the vertebrates in some meaningful way to their environment...

  18. DNA binding properties of the small cascade subunit Csa5.

    Directory of Open Access Journals (Sweden)

    Michael Daume

    Full Text Available CRISPR-Cas systems provide immunity against viral attacks in archaeal and bacterial cells. Type I systems employ a Cas protein complex termed Cascade, which utilizes small CRISPR RNAs to detect and degrade the exogenic DNA. A small sequence motif, the PAM, marks the foreign substrates. Previously, a recombinant type I-A Cascade complex from the archaeon Thermoproteus tenax was shown to target and degrade DNA in vitro, dependent on a native PAM sequence. Here, we present the biochemical analysis of the small subunit, Csa5, of this Cascade complex. T. tenax Csa5 preferentially bound ssDNA and mutants that showed decreased ssDNA-binding and reduced Cascade-mediated DNA cleavage were identified. Csa5 oligomerization prevented DNA binding. Specific recognition of the PAM sequence was not observed. Phylogenetic analyses identified Csa5 as a universal member of type I-A systems and revealed three distinct groups. A potential role of Csa5 in R-loop stabilization is discussed.

  19. Enzymatic cascade reactions involving phosphorylated intermediates: immobilization and process optimization

    NARCIS (Netherlands)

    Babich, L.

    2013-01-01

    The research described in this thesis aims to develop new strategies for the synthesis of fine chemicals by replacing conventional methods by nature-inspired technologies. The integration of multiple enzymatic steps into one-pot cascade processes is the ultimate goal to convert cheap renewable

  20. Experiments on Cascaded Quadratic Soliton Compression in Unpoled LN Waveguide

    DEFF Research Database (Denmark)

    Guo, Hairun; Zhou, Binbin; Zeng, Xianglong

    2014-01-01

    Experiments on cascaded quadratic soliton compression in unpoled phasemismatched lithium niobate waveguides are presented. Pulse self-phasemodulation dominated by an overall self-defocusing nonlinearity is observed, with an variation of pump wavelength and waveguide core width. © 2014 Optical...

  1. Advanced Dementia Research in the Nursing Home: The CASCADE Study

    Science.gov (United States)

    Mitchell, Susan L.; Kiely, Dan K.; Jones, Richard N.; Prigerson, Holly; Volicer, Ladislav; Teno, Joan M.

    2009-01-01

    Despite the growing number of persons with advanced dementia, and the need to improve their end-of-life care, few studies have addressed this important topic. The objectives of this report are to present the methodology established in the CASCADE (Choices, Attitudes, and Strategies for Care of Advanced Dementia at the End-of-Life) study, and to describe how challenges specific to this research were met. The CASCADE study is an ongoing, federally funded, 5-year prospective cohort study of nursing [nursing home (NH)] residents with advanced dementia and their health care proxies (HCPs) initiated in February 2003. Subjects were recruited from 15 facilities around Boston. The recruitment and data collection protocols are described. The demographic features, ownership, staffing, and quality of care of participant facilities are presented and compared to NHs nationwide. To date, 189 resident/HCP dyads have been enrolled. Baseline data are presented, demonstrating the success of the protocol in recruiting and repeatedly assessing NH residents with advanced dementia and their HCPs. Factors challenging and enabling implementation of the protocol are described. The CASCADE experience establishes the feasibility of conducting rigorous, multisite dementia NH research, and the described methodology serves as a detailed reference for subsequent CASCADE publications as results from the study emerge. PMID:16917187

  2. Cascade probabilistic function and the Markov's processes. Chapter 1

    International Nuclear Information System (INIS)

    2002-01-01

    In the Chapter 1 the physical and mathematical descriptions of radiation processes are carried out. The relation of the cascade probabilistic functions (CPF) for electrons, protons, alpha-particles and ions with Markov's chain is shown. The algorithms for CPF calculation with accounting energy losses are given

  3. Extension of CASCADE.04 to estimate neutron fluence and dose ...

    Indian Academy of Sciences (India)

    Capability to compute neutron dose rate is introduced for the first time in the new version of the CASCADE.04 code. Two different methods, `track length estimator' and `collision estimator' are adapted for the estimation of neutron fluence rate needed to calculate the ambient dose rate. For the validation of the methods, ...

  4. Cascade rainfall disaggregation application in U.S. Central Plains

    Science.gov (United States)

    Hourly rainfall are increasingly used in complex, process-based simulations of the environment. Long records of daily rainfall are common, but long continuous records of hourly rainfall are rare and must be developed. A Multiplicative Random Cascade (MRC) model is proposed to disaggregate observed d...

  5. Cascaded column generation for scalable predictive demand side management

    NARCIS (Netherlands)

    Toersche, Hermen; Molderink, Albert; Hurink, Johann L.; Smit, Gerardus Johannes Maria

    2014-01-01

    We propose a nested Dantzig-Wolfe decomposition, combined with dynamic programming, for the distributed scheduling of a large heterogeneous fleet of residential appliances with nonlinear behavior. A cascaded column generation approach gives a scalable optimization strategy, provided that the problem

  6. Cascading Constrained 2-D Arrays using Periodic Merging Arrays

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Laursen, Torben Vaarby

    2003-01-01

    We consider a method for designing 2-D constrained codes by cascading finite width arrays using predefined finite width periodic merging arrays. This provides a constructive lower bound on the capacity of the 2-D constrained code. Examples include symmetric RLL and density constrained codes...

  7. Trophic cascades: the primacy of trait-mediated indirect interactions

    Czech Academy of Sciences Publication Activity Database

    Schmitz, O. J.; Křivan, Vlastimil; Ovadia, O.

    2004-01-01

    Roč. 7, - (2004), s. 153-163 ISSN 1461-023X R&D Projects: GA ČR GA201/03/0091 Institutional research plan: CEZ:AV0Z5007907 Keywords : adaptive foraging * anti-predator behaviour * cascading effects Subject RIV: EH - Ecology, Behaviour Impact factor: 3.914, year: 2004

  8. Learning from a role model: A cascade or whirlpool effect?

    NARCIS (Netherlands)

    Jochemsen-van der Leeuw, H. G. A. Ria; Buwalda, Nienke; Wieringa-de Waard, Margreet; van Dijk, Nynke

    2015-01-01

    Continuing Professional Development (CPD) and Faculty Development (FD) courses have been designed in the expectation that a cascade effect will occur, consisting of a conveyance of information from the courses to clinical trainers to daily practice and/or to trainees by means of role modeling. The

  9. A short review of hadronic cascade transitions in heavy quarkonia

    International Nuclear Information System (INIS)

    Chemtob, M.; Navelet, H.

    1989-01-01

    We review briefly the current algebra, the QCD multipole expansion and the partonic quark-gluon model approaches to the hadronic cascades. We discuss the various proposals to explain the flat invariant mass observed in Υ''→ Υ + π π

  10. Emergence of a turbulent cascade in a quantum gas

    Science.gov (United States)

    Navon, Nir; Gaunt, Alexander L.; Smith, Robert P.; Hadzibabic, Zoran

    2016-11-01

    A central concept in the modern understanding of turbulence is the existence of cascades of excitations from large to small length scales, or vice versa. This concept was introduced in 1941 by Kolmogorov and Obukhov, and such cascades have since been observed in various systems, including interplanetary plasmas, supernovae, ocean waves and financial markets. Despite much progress, a quantitative understanding of turbulence remains a challenge, owing to the interplay between many length scales that makes theoretical simulations of realistic experimental conditions difficult. Here we observe the emergence of a turbulent cascade in a weakly interacting homogeneous Bose gas—a quantum fluid that can be theoretically described on all relevant length scales. We prepare a Bose-Einstein condensate in an optical box, drive it out of equilibrium with an oscillating force that pumps energy into the system at the largest length scale, study its nonlinear response to the periodic drive, and observe a gradual development of a cascade characterized by an isotropic power-law distribution in momentum space. We numerically model our experiments using the Gross-Pitaevskii equation and find excellent agreement with the measurements. Our experiments establish the uniform Bose gas as a promising new medium for investigating many aspects of turbulence, including the interplay between vortex and wave turbulence, and the relative importance of quantum and classical effects.

  11. Evidence for proteins involved in prophenoloxidase cascade Eisenia fetida earthworms

    Czech Academy of Sciences Publication Activity Database

    Kohlerová, Petra; Šilerová, Marcela; Stijlemans, B.; Dieu, M.; Halada, Petr; Josková, Radka; Beschin, A.; De Baetselier, P.; Bilej, Martin

    2006-01-01

    Roč. 176, - (2006), s. 581-587 ISSN 0174-1578 R&D Projects: GA ČR GA310/04/0806; GA AV ČR KJB500200613 Institutional research plan: CEZ:AV0Z50200510 Keywords : protein * prophenoloxidase cascade * eisenia fetida Subject RIV: EE - Microbiology, Virology Impact factor: 1.740, year: 2006

  12. Neutron spallation source and the Dubna Cascade Code

    Indian Academy of Sciences (India)

    Neutron multiplicity per incident proton, /, in collision of high energy proton beam with voluminous Pb and W targets has been estimated from the Dubna Cascade Code and compared with the available experimental data for the purpose of benchmarking of the code. Contributions of various atomic and nuclear processes ...

  13. Cascaded incremental nonlinear dynamic inversion for MAV disturbance rejection

    NARCIS (Netherlands)

    Smeur, E.J.J.; de Croon, G.C.H.E.; Chu, Q.

    2018-01-01

    This paper presents the cascaded integration of Incremental Nonlinear Dynamic Inversion (INDI) for attitude control and INDI for position control of micro air vehicles. Significant improvements over a traditional Proportional Integral Derivative (PID) controller are demonstrated in an experiment

  14. Total synthesis of ascididemin via anionic cascade ring closure

    DEFF Research Database (Denmark)

    Petersen, Ida Nymann; Crestey, François; Kristensen, Jesper Langgaard

    2012-01-01

    A new and convergent synthesis of ascididemin is presented. Using an anionic cascade ring closure as the key step, this natural product is obtained in 45% overall yield in just 6 steps starting from 2'-fluoroacetophenone. This new approach was extended to the synthesis of a new isomer...

  15. 'Cascading participation' and the role of teachers in a collaborative ...

    African Journals Online (AJOL)

    'Cascading participation' and the role of teachers in a collaborative HIV and Aids curriculum development project. D Scott, A Cooper, S Swartz. Abstract. This paper presents findings of four Grade 6 teachers' involvement as facilitators of a participatory action research (PAR) project conducted in three South African primary ...

  16. Cascade: an RNA-seq visualization tool for cancer genomics.

    Science.gov (United States)

    Shifman, Aaron R; Johnson, Radia M; Wilhelm, Brian T

    2016-01-25

    Cancer genomics projects are producing ever-increasing amounts of rich and diverse data from patient samples. The ability to easily visualize this data in an integrated an intuitive way is currently limited by the current software available. As a result, users typically must use several different tools to view the different data types for their cohort, making it difficult to have a simple unified view of their data. Here we present Cascade, a novel web based tool for the intuitive 3D visualization of RNA-seq data from cancer genomics experiments. The Cascade viewer allows multiple data types (e.g. mutation, gene expression, alternative splicing frequency) to be simultaneously displayed, allowing a simplified view of the data in a way that is tuneable based on user specified parameters. The main webpage of Cascade provides a primary view of user data which is overlaid onto known biological pathways that are either predefined or added by users. A space-saving menu for data selection and parameter adjustment allows users to access an underlying MySQL database and customize the features presented in the main view. There is currently a pressing need for new software tools to allow researchers to easily explore large cancer genomics datasets and generate hypotheses. Cascade represents a simple yet intuitive interface for data visualization that is both scalable and customizable.

  17. Intensity correlations and anticorrelations in a three-level cascade ...

    Indian Academy of Sciences (India)

    2016-11-02

    Nov 2, 2016 ... absorption spectra and the corresponding intensity– intensity correlation function (using the convention of refs [8–12]) for the probe transition. 2. Formulation. We model the atom as a three-level system in cascade configuration. The atomic level scheme is shown in figure 1. The top level |3〉 (energy E3) ...

  18. DISPLACEMENT CASCADE SIMULATION IN TUNGSTEN AT 1025 K

    Energy Technology Data Exchange (ETDEWEB)

    Setyawan, Wahyu; Nandipati, Giridhar; Roche, Kenneth J.; Heinisch, Howard L.; Kurtz, Richard J.; Wirth, Brian D.

    2013-09-30

    Molecular dynamics simulation was employed to investigate the irradiation damage properties of bulk tungsten at 1025 K (0.25 melting temperature). A comprehensive data set of primary cascade damage was generated up to primary knock-on atom (PKA) energies 100 keV. The dependence of the number of surviving Frenkel pairs (NFP) on the PKA energy (E) exhibits three different characteristic domains presumably related to the different cascade morphologies that form. The low-energy regime < 0.2 keV is characterized by a hit-or-miss type of Frenkel pair (FP) production near the displacement threshold energy of 128 eV. The middle regime 0.3 – 30 keV exhibits a sublinear dependence of log(NFP) vs log(E) associated with compact cascade morphology with a slope of 0.73. Above 30 keV, the cascade morphology consists of complex branches or interconnected damage regions. In this extended morphology, large interstitial clusters form from superposition of interstitials from nearby damage regions. Strong clustering above 30 keV results in a superlinear dependence of log(NFP) vs log(E) with a slope of 1.365. At 100 keV, an interstitial cluster of size 92 and a vacancy cluster of size 114 were observed.

  19. Separation of an inulin mixture using cascaded nanofiltration

    NARCIS (Netherlands)

    Patil, N.V.; Feng, Xiaoxia; Sewalt, J.J.W.; Boom, R.M.; Janssen, A.E.M.

    2015-01-01

    This paper examines the use of a pilot-scale spiral wound nanofiltration cascade with regard to separation of mono- and disaccharides from a mixture of inulin of different polymer sizes. The choices of the membrane and operational conditions were based on single stage experiments. Two 3-stage

  20. Energy Cascade Analysis: from Subscale Eddies to Mean Flow

    Science.gov (United States)

    Cheikh, Mohamad Ibrahim; Wonnell, Louis; Chen, James

    2017-11-01

    Understanding the energy transfer between eddies and mean flow can provide insights into the energy cascade process. Much work has been done to investigate the energy cascade at the level of the smallest eddies using different numerical techniques derived from the Navier-Stokes equations. These methodologies, however, prove to be computationally inefficient when producing energy spectra for a wide range of length scales. In this regard, Morphing Continuum Theory (MCT) resolves the length-scales issues by assuming the fluid continuum to be composed of inner structures that play the role of subscale eddies. The current study show- cases the capabilities of MCT in capturing the dynamics of energy cascade at the level of subscale eddies, through a supersonic turbulent flow of Mach 2.93 over an 8× compression ramp. Analysis of the results using statistical averaging procedure shows the existence of a statistical coupling of the internal and translational kinetic energy fluctuations with the corresponding rotational kinetic energy of the subscale eddies, indicating a multiscale transfer of energy. The results show that MCT gives a new characterization of the energy cascade within compressible turbulence without the use of excessive computational resources. This material is based upon work supported by the Air Force Office of Scientific Research under Award Number FA9550-17-1-0154.

  1. An Algebraic Approach to Signaling Cascades with n Layers

    DEFF Research Database (Denmark)

    Feliu, Elisenda; Knudsen, Michael; Andersen, Lars Nørvang

    2011-01-01

    Posttranslational modification of proteins is key in transmission of signals in cells. Many signaling pathways contain several layers of modification cycles that mediate and change the signal through the pathway. Here, we study a simple signaling cascade consisting of n layers of modification...

  2. Effect of field quantization on Rabi oscillation of equidistant cascade ...

    Indian Academy of Sciences (India)

    We have exactly solved a model of equidistant cascade four-level system interacting with a single-mode radiation field both semiclassically and quantum mechanically by exploiting its similarity with Jaynes-Cummings model. For the classical field, it is shown that the Rabi oscillation of the system initially in the first level ...

  3. Intensity correlations and anticorrelations in a three-level cascade ...

    Indian Academy of Sciences (India)

    2016-11-02

    Nov 2, 2016 ... Abstract. We study the intensity–intensity correlations of the radiation emitted on probe transition in a three- level cascade electromagnetically-induced transparency (EIT) scheme. Further, we show that by applying even a very weak incoherent pump, the nature of the emitted radiation can be switched from ...

  4. Dynamics of cascade three-level system interacting with the ...

    Indian Academy of Sciences (India)

    Abstract. We study the exact solutions of the cascade three-level atom interacting with a single mode classical and quantized field with different initial conditions of the atom. For the semiclassical model, it is found that if the atom is initially in the middle level, the time-dependent populations of the upper and lower levels are ...

  5. Dynamic signaling cascades: reversible covalent reaction-coupled molecular switches.

    Science.gov (United States)

    Ren, Yulong; You, Lei

    2015-11-11

    The research of systems chemistry exploring complex mixtures of interacting synthetic molecules has been burgeoning recently. Herein we demonstrate for the first time the coupling of molecular switches with a dynamic covalent reaction (DCR) and the modulation of created chemical cascades with a variety of inputs, thus closely mimicking a biological signaling system. A novel Michael type DCR of 10-methylacridinium perchlorate and monothiols exhibiting excellent regioselectivity and tunable affinity was discovered. A delicate balance between the unique reactivity of the reactant and the stability of the adduct leads to the generation of a strong acid in a thermodynamically controlled system. The dynamic cascade was next created via coupling of the DCR and a protonation-induced configurational switch (E/Z isomerization) through a proton relay. Detailed examination of the interdependence of the equilibrium enabled us to rationally optimize the cascade and also shed light on the possible intermediate of the switching process. Furthermore, relative independence of the coupled reactions was verified by the identification of stimuli that are able to facilitate one reaction but suppress the other. To further enhance systematic complexity, a second DCR of electrophilic aldehydes and thiols was employed for the reversible inhibition of the binary system, thus achieving the interplay of multiple equilibria. Finally, a fluorescence switch was turned on through coupling with the DCR, showcasing the versatility of our strategy. The results described herein should pave the way for the exploitation of multifunctional dynamic covalent cascades.

  6. Current Decoupling Control Strategy of Medium Voltage Cascaded Multilevel STATCOM

    Directory of Open Access Journals (Sweden)

    Zhao Xuehua

    2014-10-01

    Full Text Available As one of effective regulation methods, static synchronous compensator (STATCOM has been widespread used to regulate dynamic reactive power and solve dynamic voltage stability problems into power-grid. Through the analysis of mathematical model, cascaded STATCOM, which is constructed by several cascaded H-bridges, is a nonlinear, multivariable, strongly coupled system. It will make difficulties in the design and practical application of controller. In this paper, mathematical models of cascaded STATCOM in a -b- c and d-q coordinates are deduced. Based on the theory of internal model control and PI control strategy, the internal decoupling control algorithm is introduced to realize independent control of active current and reactive current. At the same time, decoupling control algorithms are designed and decoupling control models are given and simulated. From the combined circuit topology and control with multi-FPGA, the simulation and experimental platform of cascaded SVG, which use the control algorithms of double-loop control with the current inner loop and capacitor voltage outer loop. Both in a-b-c coordinates and d-q-0 coordinates, experiment and simulation results show that three-phase current of STATCOM has good tracking performance and control precision, which show the regulator design method and parameters setting are feasible and effective.

  7. A psychological cascade model for persisting voice problems in teachers.

    NARCIS (Netherlands)

    Jong, F.I.C.R.S. de; Cornelis, B.E.; Wuyts, F.L.; Kooijman, P.G.C.; Schutte, H.K.; Oudes, M.J.; Graamans, K.

    2003-01-01

    In 76 teachers with persisting voice problems, the maintaining factors and coping strategies were examined. Physical, functional, psychological and socioeconomic factors were assessed. A parallel was drawn to a psychological cascade model designed for patients with chronic back pain. The majority of

  8. Effect of field quantization on Rabi oscillation of equidistant cascade ...

    Indian Academy of Sciences (India)

    unitary gates relevant for the quantum computation [41,42]. However, these treat- ments are not ... veloped a dressed atom approach of calculating the probabilities with all possible initial conditions especially in the ..... the Rabi oscillation for the equidistant cascade [44] and also for lambda and vee three-level systems [46].

  9. Hydrothermal heat discharge in the Cascade Range, northwestern United States

    Science.gov (United States)

    Ingebritsen, S.E.; Mariner, R.H.

    2010-01-01

    Hydrothermal heat discharge in the Cascade Range includes the heat discharged by thermal springs, by "slightly thermal" springs that are only a few degrees warmer than ambient temperature, and by fumaroles. Thermal-spring heat discharge is calculated on the basis of chloride-flux measurements and geothermometer temperatures and totals ~ 240 MW in the U.S. part of the Cascade Range, excluding the transient post-1980 discharge at Mount St. Helens (~80 MW as of 2004-5). Heat discharge from "slightly thermal" springs is based on the degree of geothermal warming (after correction for gravitational potential energy effects) and totals ~. 660. MW. Fumarolic heat discharge is calculated by a variety of indirect and direct methods and totals ~160 MW, excluding the transient mid-1970s discharge at Mount Baker (~80 MW) and transient post-1980 discharge at Mount St. Helens (>. 230. MW as of 2005). Other than the pronounced transients at Mount St. Helens and Mount Baker, hydrothermal heat discharge in the Cascade Range appears to be fairly steady over a ~25-year period of measurement. Of the total of ~. 1050. MW of "steady" hydrothermal heat discharge identified in the U.S. part of the Cascade Range, less than 50. MW occurs north of latitude 45??15' N (~0.1 MW per km arc length from 45??15' to 49??N). Much greater rates of hydrothermal heat discharge south of 45??15'N (~1.7 MW per km arc length from 40?? to 45??15'N) may reflect the influence of Basin and Range-style extensional tectonics (faulting) that impinges on the Cascades as far north as Mount Jefferson but is not evident farther north. ?? 2010.

  10. Cascading failures in interdependent systems under a flow redistribution model

    Science.gov (United States)

    Zhang, Yingrui; Arenas, Alex; Yaǧan, Osman

    2018-02-01

    Robustness and cascading failures in interdependent systems has been an active research field in the past decade. However, most existing works use percolation-based models where only the largest component of each network remains functional throughout the cascade. Although suitable for communication networks, this assumption fails to capture the dependencies in systems carrying a flow (e.g., power systems, road transportation networks), where cascading failures are often triggered by redistribution of flows leading to overloading of lines. Here, we consider a model consisting of systems A and B with initial line loads and capacities given by {LA,i,CA ,i} i =1 n and {LB,i,CB ,i} i =1 n, respectively. When a line fails in system A , a fraction of its load is redistributed to alive lines in B , while remaining (1 -a ) fraction is redistributed equally among all functional lines in A ; a line failure in B is treated similarly with b giving the fraction to be redistributed to A . We give a thorough analysis of cascading failures of this model initiated by a random attack targeting p1 fraction of lines in A and p2 fraction in B . We show that (i) the model captures the real-world phenomenon of unexpected large scale cascades and exhibits interesting transition behavior: the final collapse is always first order, but it can be preceded by a sequence of first- and second-order transitions; (ii) network robustness tightly depends on the coupling coefficients a and b , and robustness is maximized at non-trivial a ,b values in general; (iii) unlike most existing models, interdependence has a multifaceted impact on system robustness in that interdependency can lead to an improved robustness for each individual network.

  11. Numerical integration of electromagnetic cascade equations, discussion of results for air, copper, iron, and lead

    International Nuclear Information System (INIS)

    Adler, A.; Fuchs, B.; Thielheim, K.O.

    1977-01-01

    The longitudinal development of electromagnetic cascades in air, copper, iron, and lead is studied on the basis of results derived recently by numerical integration of the cascade equations applying rather accurate expressions for the cross-sections involved with the interactions of high energy electrons, positrons, and photons in electromagnetic cascades. Special attention is given to scaling properties of transition curves. It is demonstrated that a good scaling may be achieved by means of the depth of maximum cascade development. (author)

  12. Some characteristics of the development of high energy electromagnetic cascades in the atmosphere

    International Nuclear Information System (INIS)

    Jablonski, Z.; Tomaszewski, A.; Wrotniak, J.A.

    1977-01-01

    Results of the calculations of some characteristics of electromagnetic cascades induced by cosmic radiation are showed. The cascade parameters are influenced by effect of threshold energy of gamma quanta registration in emulsion chambers. Ratio of integral gamma quanta energies in cascade to initial particle energy and mean energy weighted radius as a function of primary interaction hight, as well as total energy and number of gamma quanta in the cascade are calculated. (S.B.)

  13. DECREASING OF WATER TROPHY IN CASCADE SYSTEMS, ON EXAMPLE OF THE SOŁA RIVER DAM CASCADE (SOUTHERN POLAND

    Directory of Open Access Journals (Sweden)

    Ewa Jachniak

    2014-10-01

    Full Text Available In this thesis the subject of water self-purification in cascade systems of water reservoirs was engaged. The results of hydrobiological research of three dam reservoirs (Tresna, Porąbka and Czaniec, creating the Soła river dam cascade were presented. The trophic status of these reservoirs was defined on the grounds of the concentration of chlorophyll a, biomass of phytoplankton and occurrence of indicating species of planktonic algae. The results of research indicated on decreasing of water trophy in the layout from the highest into the lowest reservoir of the cascade. The average concentrations of chlorophyll a amounted appropriately 19,99 μg·dm-3, 8,74 μg·dm-3 and 4,29 μg·dm-3, instead the average biomass of phytoplankton amounted appropriately 4,1 mg·dm-3, 3,4 mg·dm-3 and 0,1 mg·dm-3. The observed species of algae confirmed occurrence of differences between reservoirs. In Tresna reservoir more species of phytoplankton indicating for eutrophy were thrived, instead in Porąbka and Czaniec reservoirs the species occurring in oligomesotrophic water thrived. Water self-purification in the Soła river dam cascade expressed decreasing of their fertility is important for water management of the region, because the Czaniec reservoir fulfill a function of water-supply reservoir.

  14. High-yield continuous production of nicotinic acid via nitrile hydratase–amidase cascade reactions using cascade CSMRs

    Czech Academy of Sciences Publication Activity Database

    Cantarella, L.; Gallifuoco, A.; Malandra, A.; Martínková, Ludmila; Spera, A.; Cantarella, M.

    2011-01-01

    Roč. 48, 4-5 (2011), 345-350 ISSN 0141-0229 R&D Projects: GA MŠk OC09046 Institutional research plan: CEZ:AV0Z50200510 Keywords : Nitrile hydratase-amidase cascade system * 3-Cyanopyridine bioconversion * Nicotinic acid Subject RIV: EE - Microbiology, Virology Impact factor: 2.367, year: 2011

  15. 77 FR 73651 - Cascade Energy Storage, LLC; Notice of Preliminary Permit Application Accepted for Filing and...

    Science.gov (United States)

    2012-12-11

    ... No. 14464-000] Cascade Energy Storage, LLC; Notice of Preliminary Permit Application Accepted for..., Cascade Energy Storage, LLC, filed an application for a preliminary permit, pursuant to section 4(f) of... Executive Officer, Cascade Energy Storage, LLC, 1210 W. Franklin Street, Ste. 2, Boise, Idaho 83702; phone...

  16. Single phase cascaded H5 inverter with leakage current elimination for transformerless photovoltaic system

    DEFF Research Database (Denmark)

    Guo, Xiaoqiang; Jia, X.; Lu, Z.

    2016-01-01

    Leakage current reduction is one of the important issues for the transformelress PV systems. In this paper, the transformerless single-phase cascaded H-bridge PV inverter is investigated. The common mode model for the cascaded H4 inverter is analyzed. And the reason why the conventional cascade H...

  17. The potential impact of membrane cascading on downstream processing of oligosaccharides

    NARCIS (Netherlands)

    Patil, N.V.; Janssen, A.E.M.; Boom, R.M.

    2014-01-01

    To assess the potential use of ideal nanofiltration cascades for the industrial fractionation of oligosac- charides, simulations of single, three and five stage NF cascades were carried out.Three and five stage ideal cascades show significant improvement in separation with diafiltration compared to

  18. Transplantação de baço de coelho com mixoma infeccioso na câmara anterior do ôlho da cobaia: sôbre a degeneração mixomatosa: inclusões intranucleares

    Directory of Open Access Journals (Sweden)

    C. Magarinos Torres

    1955-12-01

    Full Text Available Heterotranplantability of myxoma of rabbits was formely demonstrated when grafts from subcutaneous tissue in skin were used (MARGARINOS TÔRRES & RITA CARDOSOS, 1949. Better results are reported in this paper when grafts from the spleen of infected rabbits were employed. While grafts from normal spleen are almost completely absorbed in sixteen days, those from infected rabbits give origin to full-grown and vascularised tissue in which typical myxoma cells are predominant elements. Progressive growth of heterotransplantated myxoma cells is another similarity between infectious myxoma and malignant tumors. Formation of clear areas of circular contour (interference of a diffusible substance? associated to myxomatous degeneration is very conspicuous. Peculiar changes of the ground substance, reticular and collagenous fibers (globular swelling, rosary and bulb formation apparently related to myxomatous degeneration are described. An unexpected finding was the presence of typical intranuclear inclusion bodies in five among forty-eight grafts examined in the sixth day.

  19. Assessment on tracking error performance of Cascade P/PI, NPID and N-Cascade controller for precise positioning of xy table ballscrew drive system

    International Nuclear Information System (INIS)

    Abdullah, L; Jamaludin, Z; Rafan, N A; Jamaludin, J; Chiew, T H

    2013-01-01

    At present, positioning plants in machine tools are looking for high degree of accuracy and robustness attributes for the purpose of compensating various disturbance forces. The objective of this paper is to assess the tracking performance of Cascade P/PI, Nonlinear PID (NPID) and Nonlinear cascade (N-Cascade) controller with the existence of disturbance forces in the form of cutting forces. Cutting force characteristics at different cutting parameters; such as spindle speed rotations is analysed using Fast Fourier Transform. The tracking performance of a Nonlinear cascade controller in presence of these cutting forces is compared with NPID controller and Cascade P/PI controller. Robustness of these controllers in compensating different cutting characteristics is compared based on reduction in the amplitudes of cutting force harmonics using Fast Fourier Transform. It is found that the N-cascade controller performs better than both NPID controller and Cascade P/PI controller. The average percentage error reduction between N-cascade controller and Cascade P/PI controller is about 65% whereas the average percentage error reduction between cascade controller and NPID controller is about 82% at spindle speed of 3000 rpm spindle speed rotation. The finalized design of N-cascade controller could be utilized further for machining application such as milling process. The implementation of N-cascade in machine tools applications will increase the quality of the end product and the productivity in industry by saving the machining time. It is suggested that the range of the spindle speed could be made wider to accommodate the needs for high speed machining

  20. Mechanisms of defect production and atomic mixing in high energy displacement cascades: A molecular dynamics study

    International Nuclear Information System (INIS)

    Diaz de la Rubia, T.; Guinan, M.W.

    1991-01-01

    We have performed molecular dynamics computer simulation studies of displacement cascades in Cu at low temperature. For 25 keV recoils we observe the splitting of a cascade into subcascades and show that cascades in Cu may lead to the formation of vacancy and interstitial dislocation loops. We discuss a new mechanism of defect production based on the observation of interstitial prismatic dislocation loop punching from cascades at 10 K. We also show that below the subcascade threshold, atomic mixing in the cascade is recoil-energy dependent and obtain a mixing efficiency that scales as the square root of the primary recoil energy. 44 refs., 12 figs

  1. Basic characteristics of a low uranium enrichment cascade by centrifugation, (2)

    International Nuclear Information System (INIS)

    Kai, Tsunetoshi

    1975-01-01

    The theory for a cascade of centrifuges described in the preceding report of the same general title is further developed. First, equations describing the distributions of the flow and the mole concentration are derived from the material balance relations for a square cascade. Corresponding equations are next obtained to cover a squared-off cascade consisting of a series of square cascades. A computer program is outlined which makes it possible to obtain the shape of the most efficient squared-off cascade. The efficiency of the current form of squared-off centrifuge cascade with reflux pipes is found to be lower than obtainable with gaseous diffusion. The efficiency can be improved by the adoption of a tapered squared-off cascade with centrifuges provided with eccentric cuts to take the place of reflux pipes. The dynamic characteristics are also discussed. Analysis of the start-up behavior reveals that the equilibrium time of the centrifuge cascade is much shorter than for a coresponding gaseous diffusion cascade, and that the mole concentration of the product rapidly rises to attain steady state condition. It is also found that even when the feed flow rate fluctuates, the mole concentration of the product is relatively stable. The effect of a centrifuge failure in the cascade is examined. The optimum mole concentration for the waste effluent discarded from the cascade is calculated from the viewpoint of cost. (auth.)

  2. Damage production in atomic displacement cascades in beryllium

    Directory of Open Access Journals (Sweden)

    V.A. Borodin

    2016-12-01

    Full Text Available The paper presents the results of a molecular dynamics simulation of cascade damage production in beryllium caused by self-ion recoils in the energy range of 0.5–3keV. It is demonstrated that point defects are produced in Be preferentially in well-separated subcascades generated by secondary and higher order recoils. A linear dependence of the point defect number on the primary recoil energy is obtained with the slope that corresponds to formal atom displacement energy of ∼21eV. Most of the damage is created as single defects and the relatively high part of created point defects (∼50% survives the correlated recombination following the ballistic cascade stage and becomes freely-migrating.

  3. Beyond KNO multiplicative cascades and novel multiplicity scaling laws

    CERN Document Server

    Hegyi, S

    1999-01-01

    The collapse of multiplicity distributions P/sub n/ onto a universal scaling curve arises when P/sub n/ is expressed as a function of the standardized multiplicity (n-c)/ lambda with c and lambda being location and scale parameters governed by leading particle effects and the growth of average multiplicity. It is demonstrated that self- similar multiplicative cascade processes such as QCD parton branching naturally lead to a novel type of scaling behavior of P/sub n/ which manifests itself in Mellin space through a location change controlled by the degree of multifractality and a scale change governed by the depth of the cascade. Applying the new scaling rule it is shown how to restore data collapsing behavior of P/sub n/ measured in hh collisions at ISR and SPS energies. (21 refs).

  4. InAs based terahertz quantum cascade lasers

    Energy Technology Data Exchange (ETDEWEB)

    Brandstetter, Martin, E-mail: martin.brandstetter@tuwien.ac.at; Kainz, Martin A.; Krall, Michael; Schönhuber, Sebastian; Unterrainer, Karl [Photonics Institute and Center for Micro- and Nanostructures, Technische Universität Wien, Gusshausstrasse 27-29, 1040 Vienna (Austria); Zederbauer, Tobias; Schrenk, Werner; Andrews, Aaron Maxwell; Strasser, Gottfried [Institute for Solid State Electronics and Center for Micro- and Nanostructures, Technische Universität Wien, Floragasse 7, 1040 Vienna (Austria); Detz, Hermann [Austrian Academy of Sciences, Dr. Ignaz Seipel-Platz 2, 1010 Vienna (Austria)

    2016-01-04

    We demonstrate terahertz lasing emission from a quantum cascade structure, realized with InAs/AlAs{sub 0.16}Sb{sub 0.84} heterostructures. Due to the lower effective electron mass, InAs based active regions are expected to provide a higher optical gain compared to structures consisting of GaAs or InGaAs. The growth by molecular beam epitaxy enabled the fabrication of monolayer-thick barriers, required for the active region, which is based on a 3-well resonant phonon depletion design. Devices were processed in a double-metal waveguide geometry to ensure high mode confinement and low optical losses. Lasing emission at 3.8 THz was observed at liquid helium temperatures by applying a magnetic field perpendicular to the layered structure in order to suppress parasitic scattering channels. These results demonstrate the feasibility of InAs based active regions for terahertz quantum cascade lasers, potentially enabling higher operating temperatures.

  5. Preliminary Results of the CASCADE Hidden Sector Photon Search

    CERN Document Server

    Woollett, Nathan; Burt, Graeme; Chattopadhyay, Swapan; Dainton, John; Dexter, Amos; Goudket, Phillipe; Jenkins, Michael; Kalliokoski, Matti; Moss, Andrew; Pattalwar, Shrikant; Thakker, Trina; Williams, Peter

    2015-01-01

    Light shining through a wall experiments can be used to make measurements of photon-WISP couplings. The first stage of the CASCADE experiment at the Cockcroft Institute of Accelerator Science and Technology is intended to be a proof-of-principle experiment utilising standard microwave technologies to make a modular, cryogenic HSP detector to take advantage of future high-power superconducting cavity tests. In these proceedings we will be presenting the preliminary results of the CASCADE LSW experiment showing a peak expected exclusion of $1.10 \\times 10^{-8}$ in the mass range from 1.96$\\mu$eV to 5.38$\\mu$eV, exceeding current limits.

  6. Strontium 90 in silts of the Dnieper cascade water reservoirs

    International Nuclear Information System (INIS)

    Romanenko, V.D.; Kuz'menko, M.I.; Matvienko, L.P.; Klenus, V.G.; Nasvit, O.I.

    1989-01-01

    The change of strontium-90 content in water and silts of the Dnieper cascade water reservoirs was analyzed. It was shown, that decrease of strontium-90 content in water in time connected basically with ion exchange adsorption of strontium-90 by residues. A high sorption ability of residues made it possible for radioisotopes to reduce sharply their concentration along depth of soils. The highest concentration of radioisotopes was in the upper layers, enriched by silt. It was ascertained, that strontium-90 migration along depth of residues took place rapidly in the Kiev's water reservoir. Down the cascade strontium-90 content reduced in lower layers of residues as well as in upper layers. 4 tabs

  7. Hybrid-source impedance network and its generalized cascading concepts

    DEFF Research Database (Denmark)

    Li, Ding; Gao, Feng; Loh, Poh Chiang

    2009-01-01

    for current-type inverters. These impedance networks can in principle be combined into a single generic network entity, before generalized cascading concepts are proposed for connecting multiple of them together to form energy converters with a higher output voltage gain and other unique advantages....... It is anticipated that these concepts and their formed inverters can find applications in photovoltaic and other renewable systems, which in turn motivate the investigation initiated here on two-level and three-level generalized cascading concepts. In addition to their theoretical performance merits, practical...... shortcomings and relevant transient phenomena exhibited by the generalized concepts are discussed to provide a comprehensive knowledge base needed for weighing relevant tradeoffs before deciding on a particular application....

  8. A weakened cascade model for turbulence in astrophysical plasmas

    International Nuclear Information System (INIS)

    Howes, G. G.; TenBarge, J. M.; Dorland, W.

    2011-01-01

    A refined cascade model for kinetic turbulence in weakly collisional astrophysical plasmas is presented that includes both the transition between weak and strong turbulence and the effect of nonlocal interactions on the nonlinear transfer of energy. The model describes the transition between weak and strong MHD turbulence and the complementary transition from strong kinetic Alfven wave (KAW) turbulence to weak dissipating KAW turbulence, a new regime of weak turbulence in which the effects of shearing by large scale motions and kinetic dissipation play an important role. The inclusion of the effect of nonlocal motions on the nonlinear energy cascade rate in the dissipation range, specifically the shearing by large-scale motions, is proposed to explain the nearly power-law energy spectra observed in the dissipation range of both kinetic numerical simulations and solar wind observations.

  9. A weakened cascade model for turbulence in astrophysical plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Howes, G. G. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States); Isaac Newton Institute for Mathematical Sciences, Cambridge, CB3 0EH (United Kingdom); TenBarge, J. M. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States); Dorland, W. [Department of Physics, University of Maryland, College Park, Maryland 20742-3511 (United States); Isaac Newton Institute for Mathematical Sciences, Cambridge, CB3 0EH (United Kingdom)

    2011-10-15

    A refined cascade model for kinetic turbulence in weakly collisional astrophysical plasmas is presented that includes both the transition between weak and strong turbulence and the effect of nonlocal interactions on the nonlinear transfer of energy. The model describes the transition between weak and strong MHD turbulence and the complementary transition from strong kinetic Alfven wave (KAW) turbulence to weak dissipating KAW turbulence, a new regime of weak turbulence in which the effects of shearing by large scale motions and kinetic dissipation play an important role. The inclusion of the effect of nonlocal motions on the nonlinear energy cascade rate in the dissipation range, specifically the shearing by large-scale motions, is proposed to explain the nearly power-law energy spectra observed in the dissipation range of both kinetic numerical simulations and solar wind observations.

  10. SCC: Semantic Context Cascade for Efficient Action Detection

    KAUST Repository

    Heilbron, Fabian Caba

    2017-11-09

    Despite the recent advances in large-scale video analysis, action detection remains as one of the most challenging unsolved problems in computer vision. This snag is in part due to the large volume of data that needs to be analyzed to detect actions in videos. Existing approaches have mitigated the computational cost, but still, these methods lack rich high-level semantics that helps them to localize the actions quickly. In this paper, we introduce a Semantic Cascade Context (SCC) model that aims to detect action in long video sequences. By embracing semantic priors associated with human activities, SCC produces high-quality class-specific action proposals and prune unrelated activities in a cascade fashion. Experimental results in ActivityNet unveils that SCC achieves state-of-the-art performance for action detection while operating at real time.

  11. Superfluid Turbulence from Quantum Kelvin Wave to Classical Kolmogorov Cascades

    International Nuclear Information System (INIS)

    Yepez, Jeffrey; Vahala, George; Vahala, Linda; Soe, Min

    2009-01-01

    The main topological feature of a superfluid is a quantum vortex with an identifiable inner and outer radius. A novel unitary quantum lattice gas algorithm is used to simulate quantum turbulence of a Bose-Einstein condensate superfluid described by the Gross-Pitaevskii equation on grids up to 5760 3 . For the first time, an accurate power-law scaling for the quantum Kelvin wave cascade is determined: k -3 . The incompressible kinetic energy spectrum exhibits very distinct power-law spectra in 3 ranges of k space: a classical Kolmogorov k -(5/3) spectrum at scales greater than the outer radius of individual quantum vortex cores and a quantum Kelvin wave cascade spectrum k -3 on scales smaller than the inner radius of the quantum vortex core. The k -3 quantum Kelvin wave spectrum due to phonon radiation is robust, while the k -(5/3) classical Kolmogorov spectrum becomes robust on large grids.

  12. Cascading quantum light-matter interfaces with minimal interconnection losses

    Science.gov (United States)

    Namazi, Mehdi; Mittiga, Thomas; Kupchak, Connor; Figueroa, Eden

    2015-09-01

    The ability to interface multiple optical quantum devices is a key milestone towards the development of future quantum information processors and networks. One of the requirements for any of their constituent elements will be cascadability, i.e., the ability to drive the input of a device using the output of another one. Here, we report the cascading of quantum light-matter interfaces by storing few-photon level pulses of light in warm vapor followed by the subsequent storage of the retrieved field onto a second ensemble. We demonstrate that by using built-in purification mechanisms in the sequential storage, the final signal-to-background ratio can remain greater than one for weak pulses containing eight input photons on average.

  13. Delay time calculation for dual-wavelength quantum cascade lasers

    Energy Technology Data Exchange (ETDEWEB)

    Hamadou, A., E-mail: abd-hamado@yahoo.fr [Département des Sciences et Techniques, Faculté des Sciences et de la Technologie, Université de Bordj Bou Arreridj 34000 (Algeria); Laboratoire d’étude des surfaces et interfaces des matériaux solides (LESIMS), Sétif 19000 (Algeria); Lamari, S. [Laboratoire d’étude des surfaces et interfaces des matériaux solides (LESIMS), Sétif 19000 (Algeria); Département de Physique, Faculté des Sciences, Université Sétif 1, 19000 (Algeria); Thobel, J.-L. [Institut d' Electronique, de Microélectronique et de Nanotechnologie (IEMN), UMR 8520, Université Lille1, Avenue Poincaré, BP 60069, 59652 Villeneuve d' Ascq Cédex (France)

    2013-11-28

    In this paper, we calculate the turn-on delay (t{sub th}) and buildup (Δt) times of a midinfrared quantum cascade laser operating simultaneously on two laser lines having a common upper level. The approach is based on the four-level rate equations model describing the variation of the electron number in the states and the photon number present within the cavity. We obtain simple analytical formulae for the turn-on delay and buildup times that determine the delay times and numerically apply our results to both the single and bimode states of a quantum cascade laser, in addition the effects of current injection on t{sub th} and Δt are explored.

  14. Computer simulation studies of high energy collision cascades

    International Nuclear Information System (INIS)

    Robinson, M.T.

    1991-07-01

    A modified binary collision approximation allowing the proper order of the collisions in time was used to study cascades in Cu and Au at primary kinetic energies up to 100 keV. Nonlinearities were approximated by letting already-stopped cascade atoms become targets in later collisions, using an improved method of locating potential targets to extend the calculations to energies much higher than heretofore. Beside the effect of the approximate nonlinearity, the effect of thermal disorder in the targets was examined. Target redisplacements reduce the damage in Cu by 3% at most, but in Au they reduce it by amounts up to 20% at 100 keV. Thermal disorder is also important: by disrupting crystal effects, the damage is reduced significantly. 11 refs., 4 figs

  15. Cascade Apartments - Deep Energy Multifamily Retrofit , Kent, Washington (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2014-02-01

    In December of 2009-10, King County Housing Authority (KCHA) implemented energy retrofit improvements in the Cascade multifamily community, located in Kent, Washington (marine climate.)This research effort involved significant coordination from stakeholders KCHA, WA State Department of Commerce, utility Puget Sound Energy, and Cascade tenants. This report focuses on the following three primary BA research questions : 1. What are the modeled energy savings using DOE low income weatherization approved TREAT software? 2. How did the modeled energy savings compare with measured energy savings from aggregate utility billing analysis? 3. What is the Savings to Investment Ratio (SIR) of the retrofit package after considering utility window incentives and KCHA capitol improvement funding.

  16. Development of the cascade inertial-confinement-fusion reactor

    International Nuclear Information System (INIS)

    Pitts, J.H.

    1985-01-01

    Cascade, originally conceived as a football-shaped, steel-walled reactor containing a Li 2 O granule blanket, is now envisaged as a double-cone-shaped reactor containing a two-layered (three-zone) flowing blanket of BeO and LiAlO 2 granules. Average blanket exit temperature is 1670 0 K and gross plant efficiency (net thermal conversion efficiency) using a Brayton cycle is 55%. The reactor has a low-activation SiC-tiled wall. It rotates at 50 rpm, and the granules are transported to the top of the heat exchanger using their peripheral speed; no conveyors or lifts are required. The granules return to the reactor by gravity. After considerable analysis and experimentation, we continue to regard Cascade as a promising reactor concept with the advantages of safety, efficiency, and low activation

  17. Analysis and improvement of face detection based on surf cascade

    Science.gov (United States)

    Hu, Siquan; Zhang, Caihong; Liu, Lei

    2017-08-01

    This paper aims to study limitations of the commonly employed boosting cascade framework. We focus on the factors like data, feature, weak classifier and stages. A set of novel experiments were done to show the relationship. The model contains three key points: SURF feature, weak classifier based on logistic regression and AUC-based cascade learning algorithm. This paper adds cross validation in logistic regression creatively which improves accuracy and speeds up convergence greatly. Eventually only five stages and about 100 weak classifiers are needed. The frontal face detector improves reject rate to 99% for the first three stages, decreases number of false positive greatly and achieves comparable performance among non-CNN techniques on FDDB dataset.

  18. Continuous Emission Monitoring of Tetrafluoromethane Using Quantum Cascade Lasers

    Directory of Open Access Journals (Sweden)

    Peter Geiser

    2016-04-01

    Full Text Available Recent developments in quantum cascade lasers have enabled the development of new sensors for in-situ applications that have so far only been possible with extractive systems. In this work, a sensor is presented using a unique Wavelength Modulation Spectroscopy approach to measure tetrafluoromethane, a strong greenhouse gas. The sensor was characterized in a laboratory environment indicating a long-term detection limit of 20 ppb·m and a short-term value of well below 10 ppb·m. To demonstrate the feasibility of the sensor in a real-world environment, it was installed at an Alcoa aluminum smelter. A co-located Fourier Transform Infrared Spectrometer allowed direct comparison measurements of both systems. General agreement between the two methods was observed, leading to the conclusion that the developed in-situ quantum cascade laser based sensor has the potential to continuously measure tetrafluoromethane at aluminum smelters.

  19. Enantioselective cyclizations and cyclization cascades of samarium ketyl radicals

    Science.gov (United States)

    Kern, Nicolas; Plesniak, Mateusz P.; McDouall, Joseph J. W.; Procter, David J.

    2017-12-01

    The rapid generation of molecular complexity from simple starting materials is a key challenge in synthesis. Enantioselective radical cyclization cascades have the potential to deliver complex, densely packed, polycyclic architectures, with control of three-dimensional shape, in one step. Unfortunately, carrying out reactions with radicals in an enantiocontrolled fashion remains challenging due to their high reactivity. This is particularly the case for reactions of radicals generated using the classical reagent, SmI2. Here, we demonstrate that enantioselective SmI2-mediated radical cyclizations and cascades that exploit a simple, recyclable chiral ligand can convert symmetrical ketoesters to complex carbocyclic products bearing multiple stereocentres with high enantio- and diastereocontrol. A computational study has been used to probe the origin of the enantioselectivity. Our studies suggest that many processes that rely on SmI2 can be rendered enantioselective by the design of suitable ligands.

  20. Cascades of pile-up and dead time

    International Nuclear Information System (INIS)

    Pomme, S.

    2008-01-01

    Count loss through a cascade of pile-up and dead time is studied. Time interval density-distribution functions and throughput factors are presented for counters with a series arrangement of pile-up and extending or non-extending dead time. A counter is considered, where an artificial dead time is imposed on every counted event, in order to control the length and type of dead time. For such a system, it is relatively easy to determine an average count-loss correction factor via a live-time clock gated by the imposed dead-time signal ('live-time mode'), or otherwise to apply a correction factor based on the inversion of the throughput function ('real-time mode'). However, these techniques do not account for additional loss through pulse pile-up. In this work, counting errors associated with neglecting cascade effects are calculated for measurements in live-time and real-time mode

  1. The effects of self-interstitial clusters on cascade defect evolution beyond the primary damage state

    International Nuclear Information System (INIS)

    Heinisch, H.L.

    1997-01-01

    The intracascade evolution of the defect distributions of cascades in copper is investigated using stochastic annealing simulations applied to cascades generated with molecular dynamics (MD). The temperature and energy dependencies of annihilation, clustering and free defect production are determined for individual cascades. The annealing simulation results illustrate the strong influence on intracascade evolution of the defect configuration existing in the primary damage state. Another factor significantly affecting the evolution of the defect distribution is the rapid one-dimensional diffusion of small, glissile interstitial loops produced directly in cascades. This phenomenon introduces a cascade energy dependence of defect evolution that is apparent only beyond the primary damage state, amplifying the need for further study of the annealing phase of cascade evolution and for performing many more MD cascade simulations at higher energies

  2. A virtual component method in numerical computation of cascades for isotope separation

    International Nuclear Information System (INIS)

    Zeng Shi; Cheng Lu

    2014-01-01

    The analysis, optimization, design and operation of cascades for isotope separation involve computations of cascades. In analytical analysis of cascades, using virtual components is a very useful analysis method. For complicated cases of cascades, numerical analysis has to be employed. However, bound up to the conventional idea that the concentration of a virtual component should be vanishingly small, virtual component is not yet applied to numerical computations. Here a method of introducing the method of using virtual components to numerical computations is elucidated, and its application to a few types of cascades is explained and tested by means of numerical experiments. The results show that the concentration of a virtual component is not restrained at all by the 'vanishingly small' idea. For the same requirements on cascades, the cascades obtained do not depend on the concentrations of virtual components. (authors)

  3. Use Deflected Trailing Edge to Improve the Aerodynamic Performance and Develop Low Solidity LPT Cascade

    Science.gov (United States)

    Chao, Li; Peigang, Yan; Xiangfeng, Wang; Wanjin, Han; Qingchao, Wang

    2017-08-01

    This paper investigates the feasibility of improving the aerodynamic performance of low pressure turbine (LPT) blade cascades and developing low solidity LPT blade cascades through deflected trailing edge. A deflected trailing edge improved aerodynamic performance of both LPT blade cascades and low solidity LPT blade cascades. For standard solidity LPT cascades, deflecting the trailing edge can decrease the energy loss coefficient by 20.61 % for a Reynolds number (Re) of 25,000 and freestream turbulence intensities (FSTI) of 1 %. For a low solidity LPT cascade, aerodynamic performance was also improved by deflecting the trailing edge. Solidity of the LPT cascade can be reduced by 12.5 % for blades with a deflected trailing edge without a drop in efficiency. Here, the flow control mechanism surrounding a deflected trailing edge was also revealed.

  4. Optimized preventive replacement policy for large cascade systems

    International Nuclear Information System (INIS)

    Kretzen, H.H.

    1986-01-01

    The repair-bottleneck problem as a limiting factor for system reliability can be overcome. Design need only cover the steady state, wearout induced accumulations of failures being precluded by preventive replacements with subsequent recycling. As a result, a reliable system appears to be feasible on an economic basis, optimization in detail to be left to more precised cost-benefit studies. As a reference system the radio-frequency-generator cascade of a single-cell linear accelerator is considered. (DG)

  5. Gamma irradiation of Fabry-Perot interband cascade lasers

    Science.gov (United States)

    Myers, Tanya L.; Cannon, Bret D.; Brauer, Carolyn S.; Canedy, Chadwick L.; Kim, Chul Soo; Kim, Mijin; Merritt, Charles D.; Bewley, William W.; Vurgaftman, Igor; Meyer, Jerry R.

    2018-01-01

    The effects of gamma radiation on Fabry-Perot interband cascade lasers (ICLs) were investigated. Two ICLs were exposed to cobalt-60 gamma rays for a total dose of 500 krad(Si) each. The ICLs do not show any evidence of changes in performance, including output power, threshold current, slope efficiency, or spectral frequency. These results demonstrate that ICLs are insensitive to gamma irradiation up to exposure rates above those normally encountered within a shielded spacecraft.

  6. Spectrally resolved far-fields of terahertz quantum cascade lasers

    OpenAIRE

    Brandstetter, Martin; Schönhuber, Sebastian; Krall, Michael; Kainz, Martin A.; Detz, Hermann; Zederbauer, Tobias; Andrews, Aaron M.; Strasser, Gottfried; Unterrainer, Karl

    2016-01-01

    We demonstrate a convenient and fast method to measure the spectrally resolved far-fields of multimode terahertz quantum cascade lasers by combining a microbolometer focal plane array with an FTIR spectrometer. Far-fields of fundamental TM0 and higher lateral order TM1 modes of multimode Fabry-P\\'erot type lasers have been distinguished, which very well fit to the results obtained by a 3D finite-element simulation. Furthermore, multimode random laser cavities have been investigated, analyzing...

  7. Cascaded photonic crystal fibers for three-stage soliton compression.

    Science.gov (United States)

    Li, Qian; Cheng, Zihao

    2016-11-01

    Cascaded higher-order soliton compression in photonic crystal fibers (PCFs) is demonstrated, where both the hyperbolic secant and Gaussian input pulses are considered. Detailed fiber designs for three-stage higher-order soliton compression where soliton order is three or non-integer are presented. A highest compression factor of 221.32 has been achieved with only 49.48% pedestal energy.

  8. Cascaded VLSI neural network architecture for on-line learning

    Science.gov (United States)

    Duong, Tuan A. (Inventor); Daud, Taher (Inventor); Thakoor, Anilkumar P. (Inventor)

    1995-01-01

    High-speed, analog, fully-parallel and asynchronous building blocks are cascaded for larger sizes and enhanced resolution. A hardware-compatible algorithm permits hardware-in-the-loop learning despite limited weight resolution. A comparison-intensive feature classification application has been demonstrated with this flexible hardware and new algorithm at high speed. This result indicates that these building block chips can be embedded as application-specific-coprocessors for solving real-world problems at extremely high data rates.

  9. Scaling structure of electromagnetic cascades in dense amorphous media

    International Nuclear Information System (INIS)

    Slowinski, B.; Furtek, A.; Hassan, N.

    1996-01-01

    Experimental data concerning the longitudinal profiles of electromagnetic cascades produced by electrons of energy 2-512 GeV in lead and electrons of energy 4-49 GeV in tungsten, as well as gamma quanta of energy 100-3500 MeV in liquid xenon are analyzed from the point of view of scaling property with respect of primary energy and medium characteristics

  10. Mie scattering as a cascade of Fano resonances.

    Science.gov (United States)

    Rybin, Mikhail V; Samusev, Kirill B; Sinev, Ivan S; Semouchkin, George; Semouchkina, Elena; Kivshar, Yuri S; Limonov, Mikhail F

    2013-12-02

    We reveal that the resonant Mie scattering by high-index dielectric nanoparticles can be presented through cascades of Fano resonances. We employ the exact solution of Maxwell's equations and demonstrate that the Lorenz-Mie coefficients of the Mie problem can be expressed generically as infinite series of Fano functions as they describe interference between the background radiation originated from an incident wave and narrow-spectrum Mie scattering modes that lead to Fano resonances.

  11. Null controllability of a cascade system of Schrodinger equations

    Directory of Open Access Journals (Sweden)

    Marcos Lopez-Garcia

    2016-03-01

    Full Text Available This article presents a control problem for a cascade system of two linear N-dimensional Schrodinger equations. We address the problem of null controllability by means of a control supported in a region not satisfying the classical geometrical control condition. The proof is based on the application of a Carleman estimate with degenerate weights to each one of the equations and a careful analysis of the system in order to prove null controllability with only one control force.

  12. Cascade upgrading of γ-valerolactone to biofuels.

    Science.gov (United States)

    Yan, Kai; Lafleur, Todd; Wu, Xu; Chai, Jiajue; Wu, Guosheng; Xie, Xianmei

    2015-04-25

    Cascade upgrading of γ-valerolactone (GVL), produced from renewable cellulosic biomass, with selective conversion to biofuels pentyl valerate (PV) and pentane in one pot using a bifunctional Pd/HY catalyst is described. Excellent catalytic performance (over 99% conversion of GVL, 60.6% yield of PV and 22.9% yield of pentane) was achieved in one step. These biofuels can be targeted for gasoline and jet fuel applications.

  13. Multichannel photonic mixing based on cascade carrier suppression

    Science.gov (United States)

    Xu, Fangxing

    2015-10-01

    Designed a multi-channel photonic mixing system based on cascade carrier suppression, which can achieve frequency conversions simultaneously for multi-channels, effectively inhibit the generation of third-order intermodulation, and significantly reduce the insertion loss in the conversion process. Meanwhile, a simulation with the software Optisystem has been done, indicating excellent frequency-conversion characteristics and good scalability of this scheme, that shows the microwave photonic frequency conversion can be a potential application for microwave signal parallel processing.

  14. Tripartite correlations over two octaves from cascaded harmonic generation

    Science.gov (United States)

    Olsen, M. K.

    2018-03-01

    We analyse the output quantum tripartite correlations from an intracavity nonlinear optical system which uses cascaded nonlinearities to produce both second and fourth harmonic outputs from an input field at the fundamental frequency. Using fully quantum equations of motion, we investigate two parameter regimes and show that the system produces tripartite inseparability, entanglement and EPR steering, with the detection of these depending on the correlations being considered.

  15. A simple method for potential flow simulation of cascades

    Indian Academy of Sciences (India)

    The cascade is first transformed to a single body using a conformal mapping, and the potential flow over this body is solved using a simple higher order vortex panel method. The advantage of this method over existing methodologies is that it enables the use of higher order panel methods, as are used to solve flow past an ...

  16. The Southern Washington Cascades magmatic system imaged with magnetotellurics

    Science.gov (United States)

    Bowles-martinez, E.; Bedrosian, P.; Schultz, A.; Hill, G. J.; Peacock, J.

    2016-12-01

    The goal of the interdisciplinary iMUSH project (Imaging Magma Under Saint Helens) is to image the magmatic system of Mount Saint Helens (MSH), and to determine the relationship of this system to the greater Cascades volcanic arc. We are especially interested in an anomalously conductive crustal zone between MSH and Mount Adams known as the Southern Washington Cascades Conductor (SWCC), which early studies interpreted as accreted sediments, but more recently has been interpreted as a broad region of partial melt. MSH is located 50 km west of the main arc and is the most active of the Cascade volcanoes. Its 1980 eruption highlighted the need to understand this potentially hazardous volcanic system. We use wideband magnetotelluric (MT) data collected in 2014-2015 along with data from earlier studies to create a 3D model of the electrical resistivity throughout the region, covering MSH as well as Mount Adams and Mount Rainier along the main volcanic arc. We look at not only the volcanoes themselves, but also their relationship to one another and to regional geologic structures. Preliminary modeling identifies several conductive features, including a mid-crustal conductive region between MSH and Mount Adams that passes below Indian Heaven Volcanic Field and coincides with a region with a high Vp/Vs ratio identified in the seismic component of iMUSH. This suggests that it could be magmatic, but does not preclude the possibility of conductive sediments. Synthesis of seismic and MT data to address this question is ongoing. We also note a conductive zone running north-south just west of MSH that is likely associated with fluids within faults of the Saint Helens Seismic Zone. We finally note that curvature of the conductive lineament that defines the main Cascade arc suggests that the boundary of magmatism is influenced by compression within the Yakima Fold and Thrust Belt, east and southeast of Mount Adams.

  17. Digital Speed Cascade Control, using Scilab / Xcos Environment

    Directory of Open Access Journals (Sweden)

    Petru Chioncel

    2016-10-01

    Full Text Available This paper presents an application of digital cascade control implemented in Scilab / Xcos environment, using a P type regulator for the position adjustment circuit, a PI controller for the speed circuit adjustment; the current respectively moments control circuits are rendered by elements of PT1 type. On this basis the program is done in Scilab and the related signal block diagram implemented in Xcos; through simulation, the step response of the system is analyzed for different sampling times.

  18. A Unified Model of Secondary Electron Cascades in Diamond

    Energy Technology Data Exchange (ETDEWEB)

    Ziaja, B; London, R A; Hajdu, J

    2004-10-13

    In this paper we present a detailed and unified theoretical treatment of secondary electron cascades that follow the absorption of an X-ray photon. A Monte Carlo model has been constructed that treats in detail the evolution of electron cascades induced by photoelectrons and by Auger electrons following inner shell ionizations. Detailed calculations are presented for cascades initiated by electron energies between 0.1-10 keV. The present paper expands our earlier work by extending the primary energy range, by improving the treatment of secondary electrons, especially at low electron energies, by including ionization by holes, and by taking into account their coupling to the crystal lattice. The calculations describe the three-dimensional evolution of the electron cloud, and monitor the equivalent instantaneous temperature of the free-electron gas as the system cools. The dissipation of the impact energy proceeds predominantly through the production of secondary electrons whose energies are comparable to the binding energies of the valence (40-50 eV) and of the core electrons (300 eV). The electron cloud generated by a 10 keV electron is strongly anisotropic in the early phases of the cascade (t {le} 1 fs). At later times, the sample is dominated by low energy electrons, and these are scattered more isotropically by atoms in the sample. Our results for the total late time number of secondary electrons agree with available experimental data, and show that the emission of secondary electrons approaches saturation within about 100 fs, following the primary impact.

  19. Cascading Events, Technology and the Floods Directive: future challenges

    Directory of Open Access Journals (Sweden)

    Pescaroli Gianluca

    2016-01-01

    Full Text Available Cascading events can be referred to multidimensional disasters, where a primary trigger generates a nonlinear series of secondary emergencies that escalate in time, becoming eventually the priority to tackle. In this process, critical infrastructure can be handled as roots of vulnerabilities, because they accumulate both physical attributes and functional nodes. When compromised, they produce widespread breakdowns of society, but also orient emergency responses and long-term recovery. Although floods have been widely associated to the failure of vulnerable equipments or to the disruption of strategic sectors such as energy, communication and transportation, their integration with the emerging concept of cascading has been limited. This open topic presents many challenges for scholars, researchers and practitioners, in particular when the implementation of the EU Floods Directive is considered. The paper presents an overview of the Floods Directive and its relation with the cascading events, using case studies and examples from the existing literature to point out missing links and gaps in the legislation. Conclusions argue that the Directive considers only local geographical scales and limited temporal horizons, which can be result inadequate to limit the escalation of events.

  20. Photoexcitation cascade and quantum-relativistic jet formation in graphene

    Science.gov (United States)

    Lewandowski, Cyprian; Levitov, Leonid

    Interactions between ultra-relativistic particles can lead to striking behavior in which a high-energy particle creates showers of softer particles characterized by a collimated angular distribution aligned with the particle velocity. These showers, known as jets, are a generic phenomenon relevant for all quantum cascades of linearly dispersing particles. This talk will discuss jets formed upon photoexcitation in graphene, which due to its linear dispersion provides an appealing medium for exploring quantum-relativistic phenomena. We will study the cascade generated by carrier-carrier collisions in photon absorption, wherein a single photon creates an electron-hole (e-h) excitation that decays producing multiple near-collinear secondary e-h excitations. We will argue that the cascade can occur through an off-shell mechanism such that all the particles and holes involved reside outside the energy-momentum dispersion manifold, relieving the bottleneck arising in the on-shell process due to energy and momentum conservation. The characteristics of the jets such as the angular and energy distribution of the particles will be discussed. Photogenerated jets provide an interesting setting to investigate the carrier-carrier collision processes in graphene and other Dirac materials. We acknowledge support of the Center for Integrated Quantum Materials (CIQM) under NSF award DMR-1231319.

  1. Is current disruption associated with an inverse cascade?

    Directory of Open Access Journals (Sweden)

    Z. Vörös

    2010-06-01

    Full Text Available Current disruption (CD and the related kinetic instabilities in the near-Earth magnetosphere represent physical mechanisms which can trigger multi-scale substorm activity including global reorganizations of the magnetosphere. Lui et al. (2008 proposed a CD scenario in which the kinetic scale linear modes grow and reach the typical dipolarization scales through an inverse cascade. The experimental verification of the inverse nonlinear cascade is based on wavelet analysis. In this paper the Hilbert-Huang transform is used which is suitable for nonlinear systems and allows to reconstruct the time-frequency representation of empirical decomposed modes in an adaptive manner. It was found that, in the Lui et al. (2008 event, the modes evolve globally from high-frequencies to low-frequencies. However, there are also local frequency evolution trends oriented towards high-frequencies, indicating that the underlying processes involve multi-scale physics and non-stationary fluctuations for which the simple inverse cascade scenario is not correct.

  2. A cascaded three-phase symmetrical multistage voltage multiplier

    International Nuclear Information System (INIS)

    Iqbal, Shahid; Singh, G K; Besar, R; Muhammad, G

    2006-01-01

    A cascaded three-phase symmetrical multistage Cockcroft-Walton voltage multiplier (CW-VM) is proposed in this report. It consists of three single-phase symmetrical voltage multipliers, which are connected in series at their smoothing columns like string of batteries and are driven by three-phase ac power source. The smoothing column of each voltage multiplier is charged twice every cycle independently by respective oscillating columns and discharged in series through load. The charging discharging process completes six times a cycle and therefore the output voltage ripple's frequency is of sixth order of the drive signal frequency. Thus the proposed approach eliminates the first five harmonic components of load generated voltage ripples and sixth harmonic is the major ripple component. The proposed cascaded three-phase symmetrical voltage multiplier has less than half the voltage ripple, and three times larger output voltage and output power than the conventional single-phase symmetrical CW-VM. Experimental and simulation results of the laboratory prototype are given to show the feasibility of proposed cascaded three-phase symmetrical CW-VM

  3. Overload cascading failure on complex networks with heterogeneous load redistribution

    Science.gov (United States)

    Hou, Yueyi; Xing, Xiaoyun; Li, Menghui; Zeng, An; Wang, Yougui

    2017-09-01

    Many real systems including the Internet, power-grid and financial networks experience rare but large overload cascading failures triggered by small initial shocks. Many models on complex networks have been developed to investigate this phenomenon. Most of these models are based on the load redistribution process and assume that the load on a failed node shifts to nearby nodes in the networks either evenly or according to the load distribution rule before the cascade. Inspired by the fact that real power-grid tends to place the excess load on the nodes with high remaining capacities, we study a heterogeneous load redistribution mechanism in a simplified sandpile model in this paper. We find that weak heterogeneity in load redistribution can effectively mitigate the cascade while strong heterogeneity in load redistribution may even enlarge the size of the final failure. With a parameter θ to control the degree of the redistribution heterogeneity, we identify a rather robust optimal θ∗ = 1. Finally, we find that θ∗ tends to shift to a larger value if the initial sand distribution is homogeneous.

  4. The importance of sensory integration processes for action cascading

    Science.gov (United States)

    Gohil, Krutika; Stock, Ann-Kathrin; Beste, Christian

    2015-01-01

    Dual tasking or action cascading is essential in everyday life and often investigated using tasks presenting stimuli in different sensory modalities. Findings obtained with multimodal tasks are often broadly generalized, but until today, it has remained unclear whether multimodal integration affects performance in action cascading or the underlying neurophysiology. To bridge this gap, we asked healthy young adults to complete a stop-change paradigm which presented different stimuli in either one or two modalities while recording behavioral and neurophysiological data. Bimodal stimulus presentation prolonged response times and affected bottom-up and top-down guided attentional processes as reflected by the P1 and N1, respectively. However, the most important effect was the modulation of response selection processes reflected by the P3 suggesting that a potentially different way of forming task goals operates during action cascading in bimodal vs. unimodal tasks. When two modalities are involved, separate task goals need to be formed while a conjoint task goal may be generated when all stimuli are presented in the same modality. On a systems level, these processes seem to be related to the modulation of activity in fronto-polar regions (BA10) as well as Broca's area (BA44). PMID:25820681

  5. Boolean Models of Biological Processes Explain Cascade-Like Behavior

    Science.gov (United States)

    Chen, Hao; Wang, Guanyu; Simha, Rahul; Du, Chenghang; Zeng, Chen

    2016-01-01

    Biological networks play a key role in determining biological function and therefore, an understanding of their structure and dynamics is of central interest in systems biology. In Boolean models of such networks, the status of each molecule is either “on” or “off” and along with the molecules interact with each other, their individual status changes from “on” to “off” or vice-versa and the system of molecules in the network collectively go through a sequence of changes in state. This sequence of changes is termed a biological process. In this paper, we examine the common perception that events in biomolecular networks occur sequentially, in a cascade-like manner, and ask whether this is likely to be an inherent property. In further investigations of the budding and fission yeast cell-cycle, we identify two generic dynamical rules. A Boolean system that complies with these rules will automatically have a certain robustness. By considering the biological requirements in robustness and designability, we show that those Boolean dynamical systems, compared to an arbitrary dynamical system, statistically present the characteristics of cascadeness and sequentiality, as observed in the budding and fission yeast cell- cycle. These results suggest that cascade-like behavior might be an intrinsic property of biological processes. PMID:26821940

  6. Kinetic Simulation of the Dissipation of a Turbulent Cascade

    Science.gov (United States)

    Roberts, D. A.; Roytershteyn, V.; Wicks, R. T.

    2015-12-01

    The solar wind fluctuations undergo a turbulent cascade that presumably results, in some unknown fashion, in the deposition of energy into randomized motions, i.e. "heating." The observed evolution of spectra, cross-helicity, and non-adiabatic thermal properties of the plasma provide strong evidence for a nonlinear cascade, but the currently available temporal/spatial resolution of (mostly) single spacecraft measurments leaves many questions open. Large-scale particle-in-cell simulations allow us to explore the fate of cascading energy from "MHD" scales to the scales where wave-particle interactions become important. Simulations to date have shown a number of characteristics similar to that of solar wind plasma, including steeper magnetic spectra parallel to the mean magnetic field than perpendicular to it, a spectral break near the ion inertial length, and bounded anisotropic temperatures. Detailed analysis has revealed "magnetic holes" and nonthermal particle distributions. We are in the process of analyzing a variety of initial conditions as well as looking in more detail at issues such as nonlinear vs linear dynamics, and of how distribution functions vary with conditions in the plasma. This paper will report latest results on these and other issues.

  7. US geothermal database and Oregon cascade thermal studies: (Final report)

    Energy Technology Data Exchange (ETDEWEB)

    Blackwell, D.D.; Steele, J.L.; Carter, L.

    1988-05-01

    This report describes two tasks of different nature. The first of these tasks was the preparation of a data base for heat flow and associated ancillary information for the United States. This data base is being used as the basis for preparation of the United States portion of a geothermal map of North America. The ''Geothermal Map of North America'' will be published as part of the Decade of North American Geology (DNAG) series of the Geological Society of America. The second of these tasks was to make a geothermal evaluation of holes drilled in the Cascade Range as part of a Department of Energy (DOE)/Industry co-sponsored deep drilling project. This second task involved field work, making temperature logs in the holes, and laboratory work, measuring thermal conductivity measurements on an extensive set of samples from these holes. The culmination of this task was an interpretation of heat flow values in terms of the regional thermal conditions; implications for geothermal systems in the Cascade Range; evaluation of the effect of groundwater flow on the depths that need to be drilled for successful measurements in the Cascade Range; and investigation of the nature of the surface groundwater effects on the temperature-depth curves. 40 refs., 7 figs., 7 tabs.

  8. Synthetic cascades are enabled by combining biocatalysts with artificial metalloenzymes

    Science.gov (United States)

    Köhler, V.; Wilson, Y. M.; Dürrenberger, M.; Ghislieri, D.; Churakova, E.; Quinto, T.; Knörr, L.; Häussinger, D.; Hollmann, F.; Turner, N. J.; Ward, T. R.

    2013-02-01

    Enzymatic catalysis and homogeneous catalysis offer complementary means to address synthetic challenges, both in chemistry and in biology. Despite its attractiveness, the implementation of concurrent cascade reactions that combine an organometallic catalyst with an enzyme has proven challenging because of the mutual inactivation of both catalysts. To address this, we show that incorporation of a d6-piano stool complex within a host protein affords an artificial transfer hydrogenase (ATHase) that is fully compatible with and complementary to natural enzymes, thus enabling efficient concurrent tandem catalysis. To illustrate the generality of the approach, the ATHase was combined with various NADH-, FAD- and haem-dependent enzymes, resulting in orthogonal redox cascades. Up to three enzymes were integrated in the cascade and combined with the ATHase with a view to achieving (i) a double stereoselective amine deracemization, (ii) a horseradish peroxidase-coupled readout of the transfer hydrogenase activity towards its genetic optimization, (iii) the formation of L-pipecolic acid from L-lysine and (iv) regeneration of NADH to promote a monooxygenase-catalysed oxyfunctionalization reaction.

  9. Photoproduction of the Cascade Baryons at GlueX

    Science.gov (United States)

    Ernst, Ashley; GlueX Collaboration

    2017-09-01

    Multi-strange baryons play an important role in understanding the strong interaction and despite their importance, little is known about such hyperons. Almost all knowledge of the Cascades today stems from Kaon-nucleon interactions in bubble chamber experiments performed in the 1960s and 1970s, of which only the octet and decuplet ground states, Ξ (1320) and Ξ (1530) respectively, are well established. This research uses the GlueX experiment at Jefferson Laboratory to map out the spectrum of doubly-strange Cascade resonances, as well as to measure the spin-parity for each of the detected resonances. The first physics run for GlueX has recently been completed and a clear signature of the Ξ (1320) is observed. The systematics of the Cascade spectrum will be presented motivated by prior discoveries in the N* program. This work was supported by the U.S. Department of Energy Grant DE-FG02-92ER40735 and National Science Foundation Grant 1449440.

  10. Multi Agent System Based Wide Area Protection against Cascading Events

    DEFF Research Database (Denmark)

    Liu, Zhou; Chen, Zhe; Liu, Leo

    2012-01-01

    In this paper, a multi-agent system based wide area protection scheme is proposed in order to prevent long term voltage instability induced cascading events. The distributed relays and controllers work as a device agent which not only executes the normal function automatically but also can be mod...... the effectiveness of proposed protection strategy. The simulation results indicate that the proposed multi agent control system can effectively coordinate the distributed relays and controllers to prevent the long term voltage instability induced cascading events.......In this paper, a multi-agent system based wide area protection scheme is proposed in order to prevent long term voltage instability induced cascading events. The distributed relays and controllers work as a device agent which not only executes the normal function automatically but also can...... be modified to fulfill the extra function according to external requirements. The control center is designed as a highest level agent in MAS to coordinate all the lower agents to prevent the system wide voltage disturbance. A hybrid simulation platform with MATLAB and RTDS is set up to demonstrate...

  11. Computer simulation of cascade damage in iron: PKA mass effects

    International Nuclear Information System (INIS)

    Calder, A.; Bacon, D.J.; Barashev, A.; Osetsky, Y.

    2007-01-01

    Full text of publication follows: Results are presented from an extensive series of computer simulations of the damage created by displacement cascades in alpha-iron. The objective has been to determine for the first time the effect of the mass of the primary knock-on atom (PKA) on defect number, defect clustering and cluster morphology. Cascades with PKA energy in the range 5 to 20 keV have been simulated by molecular dynamics for temperature up to 600 K using an interatomic potential for iron for which the energy difference between the dumbbell interstitial and the crowdion is close to the value from ab initio calculation (Ackland et al., J. Phys.: Condens. Matter 2004). At least 30 cascades have been simulated for each condition in order to generate reasonable statistics. The influence of PKA species on damage has been investigated in two ways. In one, the PKA atom was treated as an Fe atom as far as its interaction with other atoms was concerned, but its atomic weight (in amu) was either 12 (C), 56 (Fe) or 209 (Bi). Pairs of Bi PKAs have also been used to mimic heavy molecular ion irradiation. In the other approach, the short-range pair part of the interatomic potential was changed from Fe-Fe to that for Bi-Fe, either with or without a change of PKA mass, in order to study the influence of high-energy collisions on the cascade outcome. It is found that PKA mass is more influential than the interatomic potential between the PKA and Fe atoms. At low cascade energy (5-10 keV), increasing PKA mass leads to a decrease in number of interstitials and vacancies. At high energy (20 keV), the main effect of increasing mass is to increase the probability of creation of interstitial and vacancy clusters in the form of 1/2 and dislocation loops. The simulation results are consistent with experimental TEM observations of damage in irradiated iron. (authors)

  12. CNNcon: improved protein contact maps prediction using cascaded neural networks.

    Directory of Open Access Journals (Sweden)

    Wang Ding

    Full Text Available BACKGROUNDS: Despite continuing progress in X-ray crystallography and high-field NMR spectroscopy for determination of three-dimensional protein structures, the number of unsolved and newly discovered sequences grows much faster than that of determined structures. Protein modeling methods can possibly bridge this huge sequence-structure gap with the development of computational science. A grand challenging problem is to predict three-dimensional protein structure from its primary structure (residues sequence alone. However, predicting residue contact maps is a crucial and promising intermediate step towards final three-dimensional structure prediction. Better predictions of local and non-local contacts between residues can transform protein sequence alignment to structure alignment, which can finally improve template based three-dimensional protein structure predictors greatly. METHODS: CNNcon, an improved multiple neural networks based contact map predictor using six sub-networks and one final cascade-network, was developed in this paper. Both the sub-networks and the final cascade-network were trained and tested with their corresponding data sets. While for testing, the target protein was first coded and then input to its corresponding sub-networks for prediction. After that, the intermediate results were input to the cascade-network to finish the final prediction. RESULTS: The CNNcon can accurately predict 58.86% in average of contacts at a distance cutoff of 8 Å for proteins with lengths ranging from 51 to 450. The comparison results show that the present method performs better than the compared state-of-the-art predictors. Particularly, the prediction accuracy keeps steady with the increase of protein sequence length. It indicates that the CNNcon overcomes the thin density problem, with which other current predictors have trouble. This advantage makes the method valuable to the prediction of long length proteins. As a result, the effective

  13. An Arabidopsis kinase cascade influences auxin-responsive cell expansion.

    Science.gov (United States)

    Enders, Tara A; Frick, Elizabeth M; Strader, Lucia C

    2017-10-01

    Mitogen-activated protein kinase (MPK) cascades are conserved mechanisms of signal transduction across eukaryotes. Despite the importance of MPK proteins in signaling events, specific roles for many Arabidopsis MPK proteins remain unknown. Multiple studies have suggested roles for MPK signaling in a variety of auxin-related processes. To identify MPK proteins with roles in auxin response, we screened mpk insertional alleles and identified mpk1-1 as a mutant that displays hypersensitivity in auxin-responsive cell expansion assays. Further, mutants defective in the upstream MAP kinase kinase MKK3 also display hypersensitivity in auxin-responsive cell expansion assays, suggesting that this MPK cascade affects auxin-influenced cell expansion. We found that MPK1 interacts with and phosphorylates ROP BINDING PROTEIN KINASE 1 (RBK1), a protein kinase that interacts with members of the Rho-like GTPases from Plants (ROP) small GTPase family. Similar to mpk1-1 and mkk3-1 mutants, rbk1 insertional mutants display auxin hypersensitivity, consistent with a possible role for RBK1 downstream of MPK1 in influencing auxin-responsive cell expansion. We found that RBK1 directly phosphorylates ROP4 and ROP6, supporting the possibility that RBK1 effects on auxin-responsive cell expansion are mediated through phosphorylation-dependent modulation of ROP activity. Our data suggest a MKK3 • MPK1 • RBK1 phosphorylation cascade that may provide a dynamic module for altering cell expansion. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  14. Probabilistic study of cascading failures in complex interdependent lifeline systems

    International Nuclear Information System (INIS)

    Hernandez-Fajardo, Isaac; Dueñas-Osorio, Leonardo

    2013-01-01

    The internal complexity of lifeline systems and their standing interdependencies can operate in conjunction to amplify the negative effects of external disruptions. This paper introduces a simulation-based methodology to evaluate the joint impact of interdependence, component fragilities, and cascading failures in systemic fragility estimates. The proposed strategy uses a graph model of interdependent networks, an enhanced betweenness centrality for cascading failures approximation, and an interdependence model accounting for coupling uncertainty in the simulation of damage propagation for probabilistic performance assessment. This methodology is illustrated through its application to a realistic set of power and water networks subjected to earthquake scenarios and random failures. Test case results reveal two key insights: (1) the intensity of a perturbation influences interdependent systemic fragility by shaping the magnitudes of initial component damage and, sometimes counter-intuitively, the subsequent interdependence effects and (2) increasing local redundancy mitigates the effects of interdependence on systemic performance, but such intervention is incapable of eliminating interdependent effects completely. The previous insights provide basic guidelines for the design of systemic retrofitting policies. Additionally, the limitations of local capacity redundancy as a fragility control measure highlight the need for a critical assessment of intervention strategies in distributed infrastructure networks. Future work will assess the fragility-reduction efficiency of strategies involving informed manipulation of individual systemic topologies and the interdependence interfaces connecting them. - Highlights: ► An new simulation methodology effectively produces interdependent fragility assessments, IFAs. ► IFAs include perturbation action, cascading failures, and interdependent effects. ► Method tested using coupled networks exposed to earthquake and random

  15. Translating Volcano Hazards Research in the Cascades Into Community Preparedness

    Science.gov (United States)

    Ewert, J. W.; Driedger, C. L.

    2015-12-01

    Research by the science community into volcanic histories and physical processes at Cascade volcanoes in the states of Washington, Oregon, and California has been ongoing for over a century. Eruptions in the 20th century at Lassen Peak and Mount St. Helen demonstrated the active nature of Cascade volcanoes; the 1980 eruption of Mount St. Helens was a defining moment in modern volcanology. The first modern volcano hazards assessments were produced by the USGS for some Cascade volcanoes in the 1960s. A rich scientific literature exists, much of which addresses hazards at these active volcanoes. That said community awareness, planning, and preparation for eruptions generally do not occur as a result of a hazard analyses published in scientific papers, but by direct communication with scientists. Relative to other natural hazards, volcanic eruptions (or large earthquakes, or tsunami) are outside common experience, and the public and many public officials are often surprised to learn of the impacts volcanic eruptions could have on their communities. In the 1980s, the USGS recognized that effective hazard communication and preparedness is a multi-faceted, long-term undertaking and began working with federal, state, and local stakeholders to build awareness and foster community action about volcano hazards. Activities included forming volcano-specific workgroups to develop coordination plans for volcano emergencies; a concerted public outreach campaign; curriculum development and teacher training; technical training for emergency managers and first responders; and development of hazard information that is accessible to non-specialists. Outcomes include broader ownership of volcano hazards as evidenced by bi-national exchanges of emergency managers, community planners, and first responders; development by stakeholders of websites focused on volcano hazards mitigation; and execution of table-top and functional exercises, including evacuation drills by local communities.

  16. Lack of plasma kallikrein-kinin system cascade in teleosts.

    Directory of Open Access Journals (Sweden)

    Marty Kwok-Shing Wong

    Full Text Available The kallikrein-kinin system (KKS consists of two major cascades in mammals: "plasma KKS" consisting of high molecular-weight (HMW kininogen (KNG, plasma kallikrein (KLKB1, and bradykinin (BK; and "tissue KKS" consisting of low molecular-weight (LMW KNG, tissue kallikreins (KLKs, and [Lys(0]-BK. Some components of the KKS have been identified in the fishes, but systematic analyses have not been performed, thus this study aims to define the KKS components in teleosts and pave a way for future physiological and evolutionary studies. Through a combination of genomics, molecular, and biochemical methods, we showed that the entire plasma KKS cascade is absent in teleosts. Instead of two KNGs as found in mammals, a single molecular weight KNG was found in various teleosts, which is homologous to the mammalian LMW KNG. Results of molecular phylogenetic and synteny analyses indicated that the all current teleost genomes lack KLKB1, and its unique protein structure, four apple domains and one trypsin domain, could not be identified in any genome or nucleotide databases. We identified some KLK-like proteins in teleost genomes by synteny and conserved domain analyses, which could be the orthologs of tetrapod KLKs. A radioimmunoassay system was established to measure the teleost BK and we found that [Arg(0]-BK is the major circulating form instead of BK, which supports that the teleost KKS is similar to the mammalian tissue KKS. Coincidently, coelacanths are the earliest vertebrate that possess both HMW KNG and KLKB1, which implies that the plasma KKS could have evolved in the early lobe-finned fish and descended to the tetrapod lineage. The co-evolution of HMW KNG and KLKB1 in lobe-finned fish and early tetrapods may mark the emergence of the plasma KKS and a contact activation system in blood coagulation, while teleosts may have retained a single KKS cascade.

  17. Multicomponent isotope separation in matched abundance ratio cascades composed of stages with large separation factors

    International Nuclear Information System (INIS)

    Von Halle, E.

    1987-06-01

    The concept of the matched abundance ratio cascade and the system of equations for performing multicomponent productivity calculations upon them has proven extremely useful for analyzing the behavior of gaseous diffusion plants in which the stage separation factors are very nearly equal to unity. Recent interest in the gas centrifuge process, in which the separation factor of a single centrifuge can be relatively large, makes desirable the extension of the theory of the matched abundance ratio cascade to cascades composed of stages with large separation factors. Equations permit the calculation of the productivity for simple cascades composed of stages with large separation factors. The concentration gradient of each of the isotopic species present can be calculated and the cascade description can be determined. An illustrative example dealing with the separation of the isotopes of tungsten in a cascade composed of gas centrifuges is included

  18. Computer codes for simulating atomic-displacement cascades in solids subject to irradiation

    International Nuclear Information System (INIS)

    Asaoka, Takumi; Taji, Yukichi; Tsutsui, Tsuneo; Nakagawa, Masayuki; Nishida, Takahiko

    1979-03-01

    In order to study atomic displacement cascades originating from primary knock-on atoms in solids subject to incident radiation, the simulation code CASCADE/CLUSTER is adapted for use on FACOM/230-75 computer system. In addition, the code is modified so as to plot the defect patterns in crystalline solids. As other simulation code of the cascade process, MARLOWE is also available for use on the FACOM system. To deal with the thermal annealing of point defects produced in the cascade process, the code DAIQUIRI developed originally for body-centered cubic crystals is modified to be applicable also for face-centered cubic lattices. By combining CASCADE/CLUSTER and DAIQUIRI, we then prepared a computer code system CASCSRB to deal with heavy irradiation or saturation damage state of solids at normal temperature. Furthermore, a code system for the simulation of heavy irradiations CASCMARL is available, in which MARLOWE code is substituted for CASCADE in the CASCSRB system. (author)

  19. Magnetotransport in quantum cascade detectors: analyzing the current under illumination

    Directory of Open Access Journals (Sweden)

    Buffaz Amandine

    2011-01-01

    Full Text Available Abstract Photocurrent measurements have been performed on a quantum cascade detector structure under strong magnetic field applied parallel to the growth axis. The photocurrent shows oscillations as a function of B. In order to describe that behavior, we have developed a rate equation model. The interpretation of the experimental data supports the idea that an elastic scattering contribution plays a central role in the behavior of those structures. We present a calculation of electron lifetime versus magnetic field which suggests that impurities scattering in the active region is the limiting factor. These experiments lead to a better understanding of these complex structures and give key parameters to optimize them further.

  20. Study for Gamma Ray Spectra of Cascading Decay

    International Nuclear Information System (INIS)

    Jassim, F.A.

    2005-01-01

    Relative intensity to the single peaks and true sum peaks to the elements of cascading decay of gamma-rays as 60 Co and 88 Y have been measured for different point source-detector distances by using 3 * 3 N al(Tl) detector into two different methods. These methods give a good information to distinguish between single and true sum peaks especially in analysis a complex pulse height spectrum ; where the relative intensity for true sum peak varies with source - detector distance while it is independent for single peak. The results of two the methods are in fair agreement

  1. Cyclization cascade of allenyl azides: A dual mechanism

    Science.gov (United States)

    López, Carlos Silva; Faza, Olalla Nieto; Feldman, Ken S.; Iyer, Malliga R.; Hester, D. Keith

    2008-01-01

    A density functional theory based computational approach to describing the mechanistic course of the allene azide cycloaddition cascade sequence has been developed. The results of these calculations permit characterization of key reactive intermediates (diradicals and/or indolidenes), and explain the different behaviour observed in the experimental studies between conjugated and non-conjugated species. Furthermore, computational analysis of certain intermediates offer insight into issues of regioselectivity and stereoselectivity in cases where different reaction channels are in competition, suggesting suitable substitutions to achieve a single regioisomer in the indole synthesis via azide-allene cyclization. PMID:17530848

  2. Intelligence Controller for STATCOM Using Cascaded Multilevel Inverter

    Directory of Open Access Journals (Sweden)

    C. C. Asir Rajan

    2010-01-01

    Full Text Available This paper presents a special gating pattern swapping technique for cascaded multilevel inverter, which is used for STATCOM.By using this technique besides minimizing the harmonic level, the inverter unit fundamental output voltages areequalized. Therefore, all the inverter units in each phase leg can equally share the exchanged active and reactive powerwith the utility grid. This greatly helps the dc-link voltages balancing control. PI Control is employed for improving performance.Fuzzy control is employed to the system for enhancing transient stability. The performance is analyzed usingdigital simulation.

  3. Complex delay dynamics of high power quantum cascade oscillators

    Science.gov (United States)

    Grillot, F.; Newell, T. C.; Gavrielides, A.; Carras, M.

    2017-08-01

    Quantum cascade lasers (QCL) have become the most suitable laser sources from the mid-infrared to the THz range. This work examines the effects of external feedback in different high power mid infrared QCL structures and shows that different conditions of the feedback wave can produce complex dynamics hence stabilization, destabilization into strong mode-competition or undamping nonlinear oscillations. As a dynamical system, reinjection of light back into the cavity also can also provoke apparition of chaotic oscillations, which must be avoided for a stable operation both at mid-infrared and THz wavelengths.

  4. Signaling Cascades of Pasteurella multocida Toxin in Immune Evasion

    Science.gov (United States)

    Kubatzky, Katharina F.; Kloos, Bianca; Hildebrand, Dagmar

    2013-01-01

    Pasteurella multocida toxin (PMT) is a protein toxin found in toxigenic strains of Pasteurella multocida. PMT is the causative agent for atrophic rhinitis in pigs, a disease characterized by loss of nasal turbinate bones due to an inhibition of osteoblast function and an increase in osteoclast activity and numbers. Apart from this, PMT acts as a strong mitogen, protects from apoptosis and has an impact on the differentiation and function of immune cells. Many signaling pathways have been elucidated, however, the effect of these signaling cascades as a means to subvert the host’s immune system are just beginning to unravel. PMID:24064721

  5. Parton cascade description of nuclear collisions at RHIC

    International Nuclear Information System (INIS)

    Nara, Yasushi

    2000-01-01

    The baryon distribution is studied by using a parton cascade model which is based on pQCD incorporating hard partonic scattering and dynamical hadronization scheme. In order to study baryon distribution, baryonic cluster formation is newly implemented as well as hadronic higher resonance states from parton/beam cluster decay. The net baryon number and charged hadron distributions are calculated with different K-factors in which parameters are fixed by elementary pp-bar data at E c.m. =200 GeV. It is found that baryon stopping behavior at SPS and RHIC energies are not consequence of hard parton scattering but soft processes. (author)

  6. Surface emitting ring quantum cascade lasers for chemical sensing

    Science.gov (United States)

    Szedlak, Rolf; Hayden, Jakob; Martín-Mateos, Pedro; Holzbauer, Martin; Harrer, Andreas; Schwarz, Benedikt; Hinkov, Borislav; MacFarland, Donald; Zederbauer, Tobias; Detz, Hermann; Andrews, Aaron Maxwell; Schrenk, Werner; Acedo, Pablo; Lendl, Bernhard; Strasser, Gottfried

    2018-01-01

    We review recent advances in chemical sensing applications based on surface emitting ring quantum cascade lasers (QCLs). Such lasers can be implemented in monolithically integrated on-chip laser/detector devices forming compact gas sensors, which are based on direct absorption spectroscopy according to the Beer-Lambert law. Furthermore, we present experimental results on radio frequency modulation up to 150 MHz of surface emitting ring QCLs. This technique provides detailed insight into the modulation characteristics of such lasers. The gained knowledge facilitates the utilization of ring QCLs in combination with spectroscopic techniques, such as heterodyne phase-sensitive dispersion spectroscopy for gas detection and analysis.

  7. Beginning CSS Cascading Style Sheets for Web Design

    CERN Document Server

    Pouncey, Ian

    2011-01-01

    Completely updated material and new examples show you what CSS can do With the latest versions of Firefox, Safari, Internet Explorer, and other browsers released, CSS is more essential than ever. This beginner guide demonstrates how cascading style sheets can be used to define styles to items in Web pages, rather than format each item individually. Each lesson in this full-color book has been methodically revised to be more concise and efficient, making your learning experience as productive as possible.Covers the latest in CSS, including the new features of Internet Explorer, Firefox, Safari,

  8. Turbulent cascade of Kelvin waves on vortex filaments

    International Nuclear Information System (INIS)

    Baggaley, Andrew W; Barenghi, Carlo F

    2011-01-01

    By numerically integrating in time the motion of vortex filaments, we study how the nonlinear interaction of Kelvin waves along vortices generates Kelvin waves of larger and larger wavenumbers (smaller and smaller wavelength). At sufficiently large wavenumbers the angular velocity of the vortices is large enough that kinetic energy is lost by sound emission. This turbulent cascade of Kelvin waves should explain why turbulence, generated in superfluid helium at very low temperature near absolute zero, quickly decays, despite the lack of any viscous dissipation.

  9. Kelvin-wave cascade and decay of superfluid turbulence

    International Nuclear Information System (INIS)

    Kozik, Evgeny; Svistunov, Boris

    2004-01-01

    Kelvin waves (kelvons), the distortion waves on vortex lines, play a key part in the relaxation of superfluid turbulence at low temperatures. We present a weak-turbulence theory of kelvons. We show that nontrivial kinetics arises only beyond the local-induction approximation and is governed by three-kelvon collisions; a corresponding kinetic equation is derived. We prove the existence of Kolmogorov cascade and find its spectrum. The qualitative analysis is corroborated by numeric study of the kinetic equation. The application of the results to the theory of superfluid turbulence is discussed

  10. Influence of interface roughness in quantum cascade lasers

    International Nuclear Information System (INIS)

    Krivas, K. A.; Winge, D. O.; Franckié, M.; Wacker, A.

    2015-01-01

    We use a numerical model based on non-equilibrium Green's functions to investigate the influence of interface roughness (IFR) scattering in terahertz quantum cascade lasers. We confirm that IFR is an important phenomenon that affects both current and gain. The simulations indicate that IFR causes a leakage current that transfers electrons from the upper to the lower laser state. In certain cases, this current can greatly reduce gain. In addition, individual interfaces and their impact on the renormalized single particle energies are studied and shown to give both blue- and red-shifts of the gain spectrum

  11. HIV treatment cascade in migrants and mobile populations.

    Science.gov (United States)

    Tanser, Frank; Bärnighausen, Till; Vandormael, Alain; Dobra, Adrian

    2015-11-01

    Health policy makers aspire to achieve an HIV treatment 'cascade' in which diagnostic and treatment services are accessed early and routinely by HIV-infected individuals. However, migrants and highly mobile individuals are likely to interact with HIV treatment programs and the healthcare system in ways that reflect their movement through time and place, affecting their successful progression through the HIV treatment cascade. We review recent research that has examined the challenges in effective and sustained HIV treatment for migrants and mobile populations. Mobility is associated with increased risk of antiretroviral therapy (ART) nonadherence, lost to follow-up, deterioration in CD4 count, HIV-related death, development of drug resistance and general noncontinuity of HIV care. Migrants' slow progression through the HIV treatment cascade can be attributed to feelings of confusion, helplessness; an inability to effectively communicate in the native language; poor knowledge about administrative or logistical requirements of the healthcare system; the possibility of deportation or expulsion based on the legal status of the undocumented migrant; fear of disclosure and social isolation from the exile or compatriot group. Travel or transition to the host country commonly makes it difficult for migrants to remain enrolled in ART programs and to maintain adherence to treatment. Existing public health systems fail to properly account for migration, and actionable knowledge of the health requirements of migrants is still lacking. A large body of research has shown that migrants are more likely to enter into the healthcare system late and are less likely to be retained at successive stages of the HIV treatment cascade. HIV-infected migrants are especially vulnerable to a wide range of social, economic and political factors that include a lack of direct access to healthcare services; exposure to difficult or oppressive work environments; the separation from family, friends

  12. On the electron-positron cascade in AGN central engines

    Science.gov (United States)

    Ford, Alex; Keenan, Brett; Medvedev, Mikhail

    2016-03-01

    Processes around spinning supermassive black holes (BH) in active galactic nuclei (AGN) are believed to determine how relativistic jets are launched and how the BH energy is extracted. The key ``ingredient'' is the origin of plasma in BH magnetospheres. In order to explore the process of the electron-positron plasma production, we developed a numerical code which models a one-dimensional (along a magnetic field line) dynamics of the cascade. Our simulations show that plasma production is controlled by the spectrum of the ambient photon field, the B-field strength, the BH spin and mass. Implications of our results to the Galactic Center and AGNs are discussed.

  13. Heat and mass transfer induced by collision cascades

    International Nuclear Information System (INIS)

    Caro, A.; Saliba, R.; Caro, M.; Alurralde, M.

    1997-01-01

    Irradiation of materials with energetic particles produces changes in the microstructure that affect mechanical properties. In previous work the authors studied the thermal aspects of the quenching of collision cascades that involve nanoscale phase transitions between the solid and the liquid states of the target. In this work they present a rigorous treatment of these phenomena, including a detailed description of the Stefan problem in three dimensions and diffusion in thermal gradients. This approach is oriented to give a quantitative description of the influence of the primary knock-on spectrum on the microstructure short after the quenching of the heat spike

  14. Cascade Classification with Adaptive Feature Extraction for Arrhythmia Detection.

    Science.gov (United States)

    Park, Juyoung; Kang, Mingon; Gao, Jean; Kim, Younghoon; Kang, Kyungtae

    2017-01-01

    Detecting arrhythmia from ECG data is now feasible on mobile devices, but in this environment it is necessary to trade computational efficiency against accuracy. We propose an adaptive strategy for feature extraction that only considers normalized beat morphology features when running in a resource-constrained environment; but in a high-performance environment it takes account of a wider range of ECG features. This process is augmented by a cascaded random forest classifier. Experiments on data from the MIT-BIH Arrhythmia Database showed classification accuracies from 96.59% to 98.51%, which are comparable to state-of-the art methods.

  15. Continuous Emission Monitoring of Tetrafluoromethane Using Quantum Cascade Lasers

    OpenAIRE

    Peter Geiser; Viacheslav Avetisov; Luis Espinoza-Nava; Nicola Menegazzo; Peter Kaspersen

    2016-01-01

    Recent developments in quantum cascade lasers have enabled the development of new sensors for in-situ applications that have so far only been possible with extractive systems. In this work, a sensor is presented using a unique Wavelength Modulation Spectroscopy approach to measure tetrafluoromethane, a strong greenhouse gas. The sensor was characterized in a laboratory environment indicating a long-term detection limit of 20 ppb·m and a short-term value of well below 10 ppb·m. To demonstrate ...

  16. Neutron spallation source and the Dubna cascade code

    CERN Document Server

    Kumar, V; Goel, U; Barashenkov, V S

    2003-01-01

    Neutron multiplicity per incident proton, n/p, in collision of high energy proton beam with voluminous Pb and W targets has been estimated from the Dubna cascade code and compared with the available experimental data for the purpose of benchmarking of the code. Contributions of various atomic and nuclear processes for heat production and isotopic yield of secondary nuclei are also estimated to assess the heat and radioactivity conditions of the targets. Results obtained from the code show excellent agreement with the experimental data at beam energy, E < 1.2 GeV and differ maximum up to 25% at higher energy. (author)

  17. New quantum cascade laser sources for sensing applications (Conference Presentation)

    Science.gov (United States)

    Troccoli, Mariano

    2017-05-01

    In this presentation we will review our most recent results on development of Quantum Cascade Lasers (QCLs) for analytical and industrial applications. QCLs have demonstrated the capability to cover the entire range of Mid-IR, Far-IR, and THz wavelengths by skillful tuning of the material design and composition and by use of intrinsic material properties via a set of techniques collectively called "bandgap engineering". The use of MOCVD, pioneered on industrial scale by AdTech Optics, has enabled the deployment of QCL devices into a diverse range of environments and applications. QCLs can be tailored to the specific application requirements due to their unprecedented flexibility in design and thanks to the leveraging of well-known III-V fabrication technologies inherited from the NIR domain. Nevertheless, several applications and new frontiers in R and D need the constant support of new developments in device features, capabilities, and performances. We have developed a wide range of devices, from high power, high efficiency multi-mode sources, to narrow-band, single mode devices with low-power consumption, and from non-linear, multi-wavelength generating devices to broadband sources and multi-emitter arrays. All our devices are grown and processed using MOCVD technology and allow us to attain competitive performances across the whole mid-IR spectral range. This talk will present an overview of our current achievements. References 1. M. Troccoli, "High power emission and single mode operation of quantum cascade lasers for industrial applications", J. Sel. Topics in Quantum Electron., 21 (6), 1-7 (2015). Invited Review. 2. Seungyong Jung, Aiting Jiang, Yifan Jiang, Karun Vijayraghavan, Xiaojun Wang, Mariano Troccoli, and Mikhail A. Belkin, "Broadly Tunable Monolithic Terahertz Quantum Cascade Laser Sources", Nature Comm. 5, 4267 (2014).. 3. Mariano Troccoli, Arkadiy Lyakh, Jenyu Fan, Xiaojun Wang, Richard Maulini, Alexei G Tsekoun, Rowel Go, C Kumar N Patel, "Long

  18. Controle qualite de l'eau de baignade de la Cascade de Man en ...

    African Journals Online (AJOL)

    La cascade Ypou du mont Tonkoui appelée couramment « cascade de Man » est un joyau naturel qui attire de nombreux touristes. Elle est très fréquentée pour sa beauté mais aussi pour la baignade. En amont de cette cascade, le paysage se compose de champs de café et selon la période, de maïs et de manioc. Il nous ...

  19. Electromagnetic Transient Response Analysis of DFIG under Cascading Grid Faults Considering Phase Angel Jumps

    DEFF Research Database (Denmark)

    Wang, Yun; Wu, Qiuwei

    2014-01-01

    This paper analysis the electromagnetic transient response characteristics of DFIG under symmetrical and asymmetrical cascading grid fault conditions considering phaseangel jump of grid. On deriving the dynamic equations of the DFIG with considering multiple constraints on balanced and unbalanced...... conditions, phase angel jumps, interval of cascading fault, electromagnetic transient characteristics, the principle of the DFIG response under cascading voltage fault can be extract. The influence of grid angel jump on the transient characteristic of DFIG is analyzed and electromagnetic response...

  20. Evaluation of refrigerating and air-conditioning technologies in heat cascading systems under the carbon dioxide emissions constraint: the proposal of the energy cascade balance table

    International Nuclear Information System (INIS)

    Shimazaki, Yoichi

    2003-01-01

    The aim of this study was to evaluate the refrigerating and air-conditioning technologies in cases of introducing both heat cascading systems and thermal recycling systems in industries located around urban areas. It is necessary to introduce heat cascading systems in the industrial sector in Japan to reduce carbon dioxide emissions. The concept of heat cascading is the multi-stage use of thermal energy by temperature level. This paper introduces three energy policies for introducing the heat cascading systems. The author develops an energy cascade model based on linear programming so as to minimize the total system costs with carbon taxes. Five cases are investigated. Carbon dioxide emission constraints result in the enhancement of heat cascading, where high temperature heat is supplied for process heating while low temperature heat is shifted to refrigeration. It was found that increasing the amount of garbage combustion waste heat could reduce electric power for the turbo compression refrigerator by promoting waste heat driven ammonia absorption refrigerator. In addition, this study proposes an energy cascade balance table with respect to the temperature level

  1. Rate theory modeling of defect evolution under cascade damage conditions: the influence of vacancy-type cascade remnants and application to the defect production characterization by microstructural analysis

    International Nuclear Information System (INIS)

    Katoh, Yutai; Muroga, Takeo; Kohyama, Akira; Stoller, R.E.; Namba, Chusei; Motojima, Osamu.

    1995-11-01

    Recent computational and experimental studies have confirmed that high energy cascades produce clustered defects of both vacancy- and interstitial-types as well as isolated point defects. However, the production probability, configuration, stability and other characteristics of the cascade clusters are not well understood in spite of the fact that clustered defect production would substantially affect the irradiation-induced microstructures and the consequent property changes in a certain range of temperatures and displacement rates. In this work, a model of point defect and cluster evolution in irradiated materials under cascade damage conditions was developed by combining the conventional reaction rate theory and the results from the latest molecular dynamics simulation studies. This paper provides a description of the model and a model-based fundamental investigation of the influence of configuration, production efficiency and the initial size distribution of cascade-produced vacancy clusters. In addition, using the model, issues on characterizing cascade-induced defect production by microstructural analysis will be discussed. In particular, the determination of cascade vacancy cluster configuration, surviving defect production efficiency and cascade-interaction volume is attempted by analyzing the temperature dependence of swelling rate and loop growth rate in austenitic steels and model alloys. (author)

  2. LIMIT SOLUTIONS OF EQUATIONS OF A DC HIGH-VOLTAGE CASCADE GENERATOR

    Directory of Open Access Journals (Sweden)

    V. O. Brzhezitsky

    2015-04-01

    Full Text Available In the paper the issue of calculating the high voltage cascade mode oscillator with a nonlinear load using the analytical method under different conditions of selection values of its components is presented. The peculiarity of the method of the study is that during multivariate calculations output parameters load generator remain unchanged. For high-voltage cascade direct current power found conditions under which can be significantly reduced high capacity capacitors cascade generator. The calculations show that acceptable for practical applications of high-voltage characteristics of cascade generators can be achieved with substantial reduction of the volume of their constituents, and thus substantial decline in their value.

  3. Method and apparatus for rapid adjustment of process gas inventory in gaseous diffusion cascades

    International Nuclear Information System (INIS)

    Dyer, R.H.; Fowler, A.H.; Vanstrum, P.R.

    1977-01-01

    The invention relates to an improved method and system for making relatively large and rapid adjustments in the process gas inventory of an electrically powered gaseous diffusion cascade in order to accommodate scheduled changes in the electrical power available for cascade operation. In the preferred form of the invention, the cascade is readied for a decrease in electrical input by simultaneously withdrawing substreams of the cascade B stream into respective process-gas-freezing and storage zones while decreasing the datum-pressure inputs to the positioning systems for the cascade control valves in proportion to the weight of process gas so removed. Consequently, the control valve positions are substantially unchanged by the reduction in invention, and there is minimal disturbance of the cascade isotopic gradient. The cascade is readied for restoration of the power cut by simultaneously evaporating the solids in the freezing zones to regenerate the process gas substreams and introducing them to the cascade A stream while increasing the aforementioned datum pressure inputs in proportion to the weight of process gas so returned. In the preferred form of the system for accomplishing these operations, heat exchangers are provided for freezing, storing, and evaporating the various substreams. Preferably, the heat exchangers are connected to use existing cascade auxiliary systems as a heat sink. A common control is employed to adjust and coordinate the necessary process gas transfers and datum pressure adjustments

  4. Predictive Current Control of Grid-tied Cascade H-bridge Inverter

    OpenAIRE

    Pástor, Marek; Dudrik, Jaroslav

    2013-01-01

    This paper presents a grid-tied cascade H-bridge inverter with predictive current control technique. The proposed 15-level cascade inverter consists of three H-bridge inverters with separated DC sources. At the output of the cascade inverter an L filter is used as a grid filter. The cascade inverter is controlled by the mean of RT-Lab. The predictive current regulator and one-phase synchronous reference frame PLL are designed with help of Rapid Control Prototyping. The proposed control method...

  5. Volatile emissions from Cascade cinder cone eruptions: Implications for future hazard assessments in the Central and Southern Cascades

    Science.gov (United States)

    Walsh, L. K.; Wallace, P. J.; Cashman, K. V.

    2012-12-01

    An abundance of hazardous effects including ash fall out, basaltic lava flows and poisonous volcanic gas have been documented at active volcanic centers (e.g. Auckland Volcanic Field, New Zealand; Bebbington and Cronin 2011) and have been inferred using tools such as geologic mapping and geochemical analyses for prehistoric eruptions (e.g. Cerro Negro, Nicaragua; Hill et al. 1995; McKnight and Williams 1997). The Cascades volcanic history is also dominated by prehistoric eruptions; however the associated hazards have yet to be studied in-depth. Short recurrence rates of cinder cone volcanism (1x10-5 to 5x10-4 events/yr; Smid et al. 2009) likely intensify the probability of human experience with cinder cone hazards. Hence, it is important to understand the effects that cinder cone volcanism can have on communities near the Cascades. In this study, we estimate volatile fluxes of prehistoric Cascade cinder cone eruptions by analyzing olivine-hosted melt inclusions and rapidly quenched tephra matrix glass. The melt inclusions provide pre-eruptive volatile concentrations whereas tephra groundmass glass provides post-eruptive volatile concentrations. By comparing initial and final concentrations we can determine the amounts of sulfur, chlorine and fluorine released into the atmosphere. We have analyzed S, Cl and F concentrations in melt inclusions from cinder cones in the Central Oregon Cascades (Collier Cone, Yapoah Crater, Four-in-One Fissure, Garrison Butte) and in Northern California near Mt. Lassen (Cinder Cone, Basalt of Old Railroad Grade, Basalt of Highway 44). Analyses of volatiles in melt inclusions and matrix glasses were done using the Cameca SX100 electron microprobe at the University of Oregon. Melt inclusions and matrix glass were run under 15kV, 50nA, and 10μm-beam conditions. For F analyses, a use of an LTAP crystal and relatively long counting times (160 sec. on peak) resulted in good analytical precision. Preliminary results for melt inclusions from

  6. Monte Carlo Modeling Electronuclear Processes in Cascade Subcritical Reactor

    CERN Document Server

    Bznuni, S A; Zhamkochyan, V M; Polyanskii, A A; Sosnin, A N; Khudaverdian, A G

    2000-01-01

    Accelerator driven subcritical cascade reactor composed of the main thermal neutron reactor constructed analogous to the core of the VVER-1000 reactor and a booster-reactor, which is constructed similar to the core of the BN-350 fast breeder reactor, is taken as a model example. It is shown by means of Monte Carlo calculations that such system is a safe energy source (k_{eff}=0.94-0.98) and it is capable of transmuting produced radioactive wastes (neutron flux density in the thermal zone is PHI^{max} (r,z)=10^{14} n/(cm^{-2} s^{-1}), neutron flux in the fast zone is respectively equal PHI^{max} (r,z)=2.25 cdot 10^{15} n/(cm^{-2} s^{-1}) if the beam current of the proton accelerator is k_{eff}=0.98 and I=5.3 mA). Suggested configuration of the "cascade" reactor system essentially reduces the requirements on the proton accelerator current.

  7. Robustness of interrelated traffic networks to cascading failures.

    Science.gov (United States)

    Su, Zhen; Li, Lixiang; Peng, Haipeng; Kurths, Jürgen; Xiao, Jinghua; Yang, Yixian

    2014-06-24

    The vulnerability to real-life networks against small initial attacks has been one of outstanding challenges in the study of interrelated networks. We study cascading failures in two interrelated networks S and B composed from dependency chains and connectivity links respectively. This work proposes a realistic model for cascading failures based on the redistribution of traffic flow. We study the Barabási-Albert networks (BA) and Erdős-Rényi graphs (ER) with such structure, and found that the efficiency sharply decreases with increasing percentages of the dependency nodes for removing a node randomly. Furthermore, we study the robustness of interrelated traffic networks, especially the subway and bus network in Beijing. By analyzing different attacking strategies, we uncover that the efficiency of the city traffic system has a non-equilibrium phase transition at low capacity of the networks. This explains why the pressure of the traffic overload is relaxed by singly increasing the number of small buses during rush hours. We also found that the increment of some buses may release traffic jam caused by removing a node of the bus network randomly if the damage is limited. However, the efficiencies to transfer people flow will sharper increase when the capacity of the subway network α(S) > α0.

  8. FY 2005 Quantum Cascade Laser Alignment System Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Tanya L.; Cannon, Bret D.; Wojcik, Michael D.; Broocks, Bryan T.; Stewart, Timothy L.; Hatchell, Brian K.

    2006-01-11

    The Alignment Lasers Task of Pacific Northwest National Laboratory's (PNNL's) Remote Spectroscopy Project (Project PL211I) is a co-funded project between DOE NA-22 and a Classified Client. This project, which began in the second half of FY03, involved building and delivering a Quantum Cascade (QC) Laser Alignment System to be used for testing the pupil alignment of an infrared sensor by measuring the response from four pairs of diametrically opposed QC lasers. PNNL delivered the system in FY04 and provided technical assistance in FY05 culminating into a successful demonstration of the system. This project evolved from the Laser Development Task of PL211I, which is involved in developing novel laser technology to support development of advanced chemical sensors for detecting the proliferation of nuclear weapons. The laser systems are based on quantum cascade (QC) lasers, a new semiconductor source in the infrared. QC lasers can be tailored to emit light throughout the infrared region (3.5 ? 17 ?m) and have high output power and stability. Thus, these lasers provide an infrared source with superb power and spectral stability enabling them to be used for applications such as alignment and calibration in addition to chemical sensing.

  9. Emotional intelligence: an integrative meta-analysis and cascading model.

    Science.gov (United States)

    Joseph, Dana L; Newman, Daniel A

    2010-01-01

    Research and valid practice in emotional intelligence (EI) have been impeded by lack of theoretical clarity regarding (a) the relative roles of emotion perception, emotion understanding, and emotion regulation facets in explaining job performance; (b) conceptual redundancy of EI with cognitive intelligence and Big Five personality; and (c) application of the EI label to 2 distinct sets of constructs (i.e., ability-based EI and mixed-based EI). In the current article, the authors propose and then test a theoretical model that integrates these factors. They specify a progressive (cascading) pattern among ability-based EI facets, in which emotion perception must causally precede emotion understanding, which in turn precedes conscious emotion regulation and job performance. The sequential elements in this progressive model are believed to selectively reflect Conscientiousness, cognitive ability, and Neuroticism, respectively. "Mixed-based" measures of EI are expected to explain variance in job performance beyond cognitive ability and personality. The cascading model of EI is empirically confirmed via meta-analytic data, although relationships between ability-based EI and job performance are shown to be inconsistent (i.e., EI positively predicts performance for high emotional labor jobs and negatively predicts performance for low emotional labor jobs). Gender and race differences in EI are also meta-analyzed. Implications for linking the EI fad in personnel selection to established psychological theory are discussed. Copyright 2009 APA, all rights reserved.

  10. Electron-positron-photon cascades in the strong laser field

    Science.gov (United States)

    Legkov, Maxim; Fedotov, Alexander

    2012-06-01

    At nearest future several ambitious projects (such as ELI and HiPER) may provide laser filed intensity up to 10^23--10^24 W/cm^2. In such strong fields quantum effects are essential. The most important among them is production of QED cascades. In this paper external field intensity is considered as ultra-relativistic but subcritical. Using a model of two colliding counter-propagating laser beams it was shown that the number of particles during the process is growing exponentially in time. This leads to vast formation of electron-positron-photon plasma. According to numerical simulations, this plasma quickly absorbs an essential part of the energy of the laser field thus leading to its depletion. Numerical simulation has been also performed for a case of high-energetic particle and laser beam collision. Probability rates of direct and recombination processes have been theoretically studied. Under some conditions, recombination may come into play and suppress cascade development. Using approximation of radiation in forward direction, system of kinetic equations, which describes plasma evaluation, was constructed. According to qualitative estimations based on kinetic equations, it was shown that recombination processes can be neglected for optical frequencies range of external field.

  11. Landscape variation influences trophic cascades in dengue vector food webs.

    Science.gov (United States)

    Weterings, Robbie; Umponstira, Chanin; Buckley, Hannah L

    2018-02-01

    The epidemiology of vector-borne diseases is governed by a structured array of correlative and causative factors, including landscape (for example, rural versus urban), abiotic (for example, weather), and biotic (for example, food web) factors. Studies of mosquito-borne diseases rarely address these multiple factors at large spatial scales, which limits insights into how human alterations of landscapes and food webs alter mosquito abundance. We used structural equation modeling to identify the relative magnitude and direction of landscape, abiotic, and food web factors on Aedes larvae and adults across 70 sites in northern Thailand. Food web factors were modeled as mosquito-predator trophic cascades. Landscape context affected mosquito-predator communities in aquatic and terrestrial environments via cascading food web interactions. Several mosquito predators within these food webs showed potential as biocontrol agents in mosquito population control, but their potentials for control were landscape-dependent. In terrestrial food webs, the habitat-sensitive tokay gecko structured mosquito-predator communities, indicating that a conservation approach to vector control could be a useful addition to existing control efforts.

  12. Artifact removal from EEG signals using adaptive filters in cascade

    International Nuclear Information System (INIS)

    Garces Correa, A; Laciar, E; Patino, H D; Valentinuzzi, M E

    2007-01-01

    Artifacts in EEG (electroencephalogram) records are caused by various factors, like line interference, EOG (electro-oculogram) and ECG (electrocardiogram). These noise sources increase the difficulty in analyzing the EEG and to obtaining clinical information. For this reason, it is necessary to design specific filters to decrease such artifacts in EEG records. In this paper, a cascade of three adaptive filters based on a least mean squares (LMS) algorithm is proposed. The first one eliminates line interference, the second adaptive filter removes the ECG artifacts and the last one cancels EOG spikes. Each stage uses a finite impulse response (FIR) filter, which adjusts its coefficients to produce an output similar to the artifacts present in the EEG. The proposed cascade adaptive filter was tested in five real EEG records acquired in polysomnographic studies. In all cases, line-frequency, ECG and EOG artifacts were attenuated. It is concluded that the proposed filter reduces the common artifacts present in EEG signals without removing significant information embedded in these records

  13. Temperature insensitive curvature sensor based on cascading photonic crystal fiber

    Science.gov (United States)

    Fu, Guangwei; Li, Yunpu; Fu, Xinghu; Jin, Wa; Bi, Weihong

    2018-03-01

    A temperature insensitive curvature sensor is proposed based on cascading photonic crystal fiber. Using the arc fusion splicing method, this sensor is fabricated by cascading together a single-mode fiber (SMF), a three layers air holes structure of photonic crystal fiber (3PCF), a five layers air holes structure of photonic crystal fiber (5PCF) and a SMF in turn. So the structure SMF-3PCF-5PCF-SMF can be obtained with a total length of 20 mm. During the process of fabrication, the splicing machine parameters and the length of each optical fiber are adjusted to obtain a high sensitivity curvature sensor. The experimental results show that the curvature sensitivity is -8.40 nm/m-1 in the curvature variation range of 0-1.09 m-1, which also show good linearity. In the range of 30-90 °C, the temperature sensitivity is only about 3.24 pm/°C, indicating that the sensor is not sensitive to temperature. The sensor not only has the advantages of easy fabricating, simple structure, high sensitivity but also can solve the problem of temperature measurement cross sensitivity, so it can be used for different areas including aerospace, large-scale bridge, architectural structure health monitoring and so on.

  14. Design strategy for terahertz quantum dot cascade lasers.

    Science.gov (United States)

    Burnett, Benjamin A; Williams, Benjamin S

    2016-10-31

    The development of quantum dot cascade lasers has been proposed as a path to obtain terahertz semiconductor lasers that operate at room temperature. The expected benefit is due to the suppression of nonradiative electron-phonon scattering and reduced dephasing that accompanies discretization of the electronic energy spectrum. We present numerical modeling which predicts that simple scaling of conventional quantum well based designs to the quantum dot regime will likely fail due to electrical instability associated with high-field domain formation. A design strategy adapted for terahertz quantum dot cascade lasers is presented which avoids these problems. Counterintuitively, this involves the resonant depopulation of the laser's upper state with the LO-phonon energy. The strategy is tested theoretically using a density matrix model of transport and gain, which predicts sufficient gain for lasing at stable operating points. Finally, the effect of quantum dot size inhomogeneity on the optical lineshape is explored, suggesting that the design concept is robust to a moderate amount of statistical variation.

  15. Infinite cascades of phase transitions in the classical Ising chain

    Science.gov (United States)

    Timonin, P. N.; Chitov, Gennady Y.

    2017-12-01

    We report exact results on one of the best studied models in statistical physics: the classical antiferromagnetic Ising chain in a magnetic field. We show that the model possesses an infinite cascade of thermal phase transitions (also known as disorder lines or geometric phase transitions). The phase transition is signaled by a change of asymptotic behavior of the nonlocal string-string correlation functions when their monotonic decay becomes modulated by incommensurate oscillations. The transitions occur for rarefied (m -periodic) strings with arbitrary odd m . We propose a duality transformation which maps the Ising chain onto the m -leg Ising tube with nearest-neighbor couplings along the legs and the plaquette four-spin interactions of adjacent legs. Then the m -string correlation functions of the Ising chain are mapped onto the two-point spin-spin correlation functions along the legs of the m -leg tube. We trace the origin of these cascades of phase transitions to the lines of the Lee-Yang zeros of the Ising chain in m -periodic complex magnetic field, allowing us to relate these zeros to the observable (and potentially measurable) quantities.

  16. High-Speed Operation of Interband Cascade Lasers

    Science.gov (United States)

    Soibel, Alexander; Hill, Cory J.; Keo, Sam A.; Wright, Malcom W.; Farr, William H.; Yang, Rui Q.; Liu, H. C.

    2010-01-01

    Optical sources operating in the atmospheric window of 3-5 microns are of particular interest for the development of free-space optical communication link. It is more advantageous to operate the free-space optical communication link in 3-5-microns atmospheric transmission window than at the telecom wavelength of 1.5 m due to lower optical scattering, scintillation, and background radiation. However, the realization of optical communications at the longer wavelength has encountered significant difficulties due to lack of adequate optical sources and detectors operating in the desirable wavelength regions. Interband Cascade (IC) lasers are novel semiconductor lasers that have a great potential for the realization of high-power, room-temperature optical sources in the 3-5-microns wavelength region, yet no experimental work, until this one, was done on high-speed direct modulation of IC lasers. Here, highspeed interband cascade laser, operating at wavelength 3.0 m, has been developed and the first direct measurement of the laser modulation bandwidth has been performed using a unique, highspeed quantum well infrared photodetector (QWIP). The developed laser has modulation bandwidth exceeding 3 GHz. This constitutes a significant increase of the IC laser modulation bandwidth over currently existing devices. This result has demonstrated suitability of IC lasers as a mid-IR light source for multi-GHz free-space optical communications links

  17. Aspects of microstructure evolution under cascade damage conditions

    International Nuclear Information System (INIS)

    Singh, B.N.; Trinkaus, H.; Barashev, A.V.

    1997-01-01

    The conventional theoretical models describing the damage accumulation, particularly void swelling, under cascade damage conditions do not include treatments of important features such as intracascade clustering of self-interstitial atoms (SIAs) and one-dimensional glide of SIA clusters produced in the cascades. Recently, it has been suggested that the problem can be treated in terms of 'production bias' and one-dimensional glide of small SIA clusters. In the earlier treatments a 'mean size approximation' was used for the defect clusters and cavities evolving during irradiation. In the present work, we use the 'size distribution function' to determine the dose dependence of sink strengths, vacancy supersaturation and void swelling as a function of dislocation density and grain size within the framework of production bias model and glide of small SIA clusters. In this work, the role of the sessile-glissile loop transformation (due to vacancy supersaturation) on the damage accumulation behaviour is included. The calculated results on void swelling are compared with the experimental results as well as the results of the earlier calculations using the 'mean size approximation'. The calculated results agree very well with the experimental results. (orig.)

  18. Particulate size distribution cascade analyzer for spacecraft contamination monitoring

    Science.gov (United States)

    Wallace, D. A.; Chuan, R. L.

    1975-01-01

    A cascade particulate analyzer was developed for nearly real time measurement of the contaminating particulate size distribution in the spacecraft interior ambient environment and as a real time total impacting particulate mass monitor under vacuum conditions. The analyzer has four stages, the first stage is a basic 10 MHz quartz crystal microbalance used widely on spacecraft (such as Skylab) for contamination monitoring purposes. In this application the front sensing crystal is coated with a low vapor pressure adhesive grease which captures impacting particles. This first stage has a wide viewing angle and measures total particulate mass impacting the crystal while the unit is exposed to the vacuum environment. The remaining three states form an aerodynamic impaction cascade with individual quartz crystal microbalances at each stage acting as accumulated mass sensing elements. These three stages thus give relative mass distribution of particulates in three ranges, particles having effective diameter greater than 5 micron, particles between 1 and 5 micron diameter and particles 0.3 to 1 micron diameter.

  19. Honeywell Cascade Distiller System Performance Testing Interim Results

    Science.gov (United States)

    Callahan, Michael R.; Sargusingh, Miriam

    2014-01-01

    The ability to recover and purify water through physiochemical processes is crucial for realizing long-term human space missions, including both planetary habitation and space travel. Because of their robust nature, distillation systems have been actively pursued as one of the technologies for water recovery. The Cascade Distillation System (CDS) is a vacuum rotary distillation system with potential for greater reliability and lower energy costs than existing distillation systems. The CDS was previously under development through Honeywell and NASA. In 2009, an assessment was performed to collect data to support down-selection and development of a primary distillation technology for application in a lunar outpost water recovery system. Based on the results of this testing, an expert panel concluded that the CDS showed adequate development maturity, TRL-4, together with the best product water quality and competitive weight and power estimates to warrant further development. The Advanced Exploration Systems (AES) Water Recovery Project (WRP) worked to address weaknesses identified by The Panel; namely bearing design and heat pump power efficiency. Testing at the NASA-JSC Advanced Exploration System Water Laboratory (AES Water Lab) using a prototype Cascade Distillation Subsystem (CDS) wastewater processor (Honeywell International, Torrance, Calif.) with test support equipment and control system developed by Johnson Space Center was performed to evaluate performance of the system with the upgrades. The CDS will also have been challenged with ISS analog waste streams and a subset of those being considered for Exploration architectures. This paper details interim results of the AES WRP CDS performance testing.

  20. Targeting the Complement Cascade: Novel Treatments Coming down the Pike

    Science.gov (United States)

    Thurman, Joshua M.; Le Quintrec, Moglie

    2016-01-01

    The complement cascade is a vital component of both the innate and adaptive immune systems. Complement activation also contributes to the pathogenesis of many diseases, however, and the kidney is particularly susceptible to complement-mediated injury. Drugs that block complement activation can rapidly reduce tissue inflammation and also attenuate the adaptive immune response to foreign and tissue antigens. Eculizumab is a monoclonal antibody that prevents the cleavage of C5. It has been approved for the treatment of atypical hemolytic uremic syndrome (aHUS), and it has been used in selected patients with other kidney diseases. Many additional drugs are also in development for blocking the complement cascade, including new monoclonal antibodies, recombinant proteins, small molecules, and small interfering RNA (siRNA) agents. Validation of these new drugs as effective treatments for kidney diseases faces several challenges. Many complement-mediated kidney diseases are rare, so it is not feasible to test all of the new drugs in numerous different rare diseases. The onset and course of the diseases are heterogeneous and many of these diseases also carry a life-long risk of recurrence, and it is not clear how long complement inhibition must be maintained. In spite of these challenges, new therapeutic options for targeting the complement system will likely become available in the near future and may prove useful for treating patients with kidney disease. PMID:27325183

  1. Bending mode flutter in a transonic linear cascade

    Science.gov (United States)

    Govardhan, Raghuraman; Jutur, Prahallada

    2017-11-01

    Vibration related issues like flutter pose a serious challenge to aircraft engine designers. The phenomenon has gained relevance for modern engines that employ thin and long fan blade rows to satisfy the growing need for compact and powerful engines. The tip regions of such blade rows operate with transonic relative flow velocities, and are susceptible to bending mode flutter. In such cases, the flow field around individual blades of the cascade is dominated by shock motions generated by the blade motions. In the present work, a new transonic linear cascade facility with the ability to oscillate a blade at realistic reduced frequencies has been developed. The facility operates at a Mach number of 1.3, with the central blade being oscillated in heave corresponding to the bending mode of the rotor. The susceptibility of the blade to undergo flutter at different reduced frequencies is quantified by the cycle-averaged power transfer to the blade calculated using the measured unsteady load on the oscillating blade. These measurements show fluid excitation (flutter) at low reduced frequencies and fluid damping (no flutter) at higher reduced frequencies. Simultaneous measurements of the unsteady shock motions are done with high speed shadowgraphy to elucidate the differences in shock motions between the excitation and damping cases.

  2. Probability of large explosive volcanic eruptions in the Cascades

    Science.gov (United States)

    Nathenson, M.; Clynne, M. A.

    2011-12-01

    Estimating the probability of large explosive eruptions in the Cascades is problematic because they occur relatively infrequently. Although some volcanic centers have been more likely to have large eruptions than others, the calculation of the probability of large eruptions for individual volcanic centers is inappropriate. A center that has had a large eruption in the past will not necessarily have a large eruption in the future, and the occurrence for individual volcanic centers is too infrequent to have much confidence in a probability estimate. The sources of some large eruptions are ambiguous (e.g. Shevlin Park Tuff, Oregon) or unknown (Dibekulewe ash), but because the effects of large eruptions are quite widespread, the precise location of the source is less important in terms of hazards. Thus, we focus on the calculation of probability of large eruptions for the Cascade arc as a whole. To estimate the probability, we have chosen a time period for documenting eruptions of 1.15 Ma (the age of the eruption of Kulshan caldera) as a balance between the likelihood of there being good information but with a long enough time period to get a reasonable number of occurrences. We have compiled data from the literature on eruptions larger than 5 km3 in erupted volume to exclude the relatively frequent eruptions ~1-2 km3. The largest eruptions are clearly or likely to have been associated with caldera formation. For erupted volumes greater than 5 km3, 19 events have occurred in the last 1.15 Ma. A plot of event number versus age shows a high rate of occurrence since 13.5 ka and a much lower rate before then. Most of the events since 13.5 ka are 5-10 km3. Events 10 km3 and larger have occurred at a reasonably constant rate since 630 ka. The difference between the two data sets is probably the poor preservation of deposits for events between 5 and 10 km3 that occurred prior to the ending of the glaciation at about 15 ka. Before 630 ka, the only eruption > 10 km3 is Kulshan

  3. Slab melting and magma formation beneath the southern Cascade arc

    Science.gov (United States)

    Walowski, Kristina J.; Wallace, Paul J.; Clynne, Michael A.; Rasmussen, D.J.; Weis, D.

    2016-01-01

    The processes that drive magma formation beneath the Cascade arc and other warm-slab subduction zones have been debated because young oceanic crust is predicted to largely dehydrate beneath the forearc during subduction. In addition, geochemical variability along strike in the Cascades has led to contrasting interpretations about the role of volatiles in magma generation. Here, we focus on the Lassen segment of the Cascade arc, where previous work has demonstrated across-arc geochemical variations related to subduction enrichment, and H-isotope data suggest that H2O in basaltic magmas is derived from the final breakdown of chlorite in the mantle portion of the slab. We use naturally glassy, olivine-hosted melt inclusions (MI) from the tephra deposits of eight primitive (MgO>7 wt%) basaltic cinder cones to quantify the pre-eruptive volatile contents of mantle-derived melts in this region. The melt inclusions have B concentrations and isotope ratios that are similar to mid-ocean ridge basalt (MORB), suggesting extensive dehydration of the downgoing plate prior to reaching sub-arc depths and little input of slab-derived B into the mantle wedge. However, correlations of volatile and trace element ratios (H2O/Ce, Cl/Nb, Sr/Nd) in the melt inclusions demonstrate that geochemical variability is the result of variable addition of a hydrous subduction component to the mantle wedge. Furthermore, correlations between subduction component tracers and radiogenic isotope ratios show that the subduction component has less radiogenic Sr and Pb than the Lassen sub-arc mantle, which can be explained by melting of subducted Gorda MORB beneath the arc. Agreement between pMELTS melting models and melt inclusion volatile, major, and trace element data suggests that hydrous slab melt addition to the mantle wedge can produce the range in primitive compositions erupted in the Lassen region. Our results provide further evidence that chlorite-derived fluids from the mantle portion of the

  4. Nitrogen Cascade: An Opportunity to Integrate Biogeochemistry and Policy

    Science.gov (United States)

    Galloway, J. N.; Moomaw, W. R.; Theis, T. L.

    2008-12-01

    It began with micro-organisms millions of years ago, was enhanced by the burning of fossil carbon in the last several hundred years, and was magnified by a patent filed one hundred years ago. Today, the combined actions of cultivation-induced biological nitrogen fixation, fossil fuel combustion and the Haber-Bosch process have exceeded natural terrestrial processes in converting N22 to nitrogen compounds that are biologically, chemically or physically reactive (reactive nitrogen, Nr). While the benefits of Nr are well understood, many of the adverse consequences of excessive Nr are invisible from a policy perspective. Over the past century, the fundamental knowledge on nitrogen processes has advanced to the point where we have a good understanding of nitrogen's biogeochemical cycle, the role of humans in altering the cycle, and the consequences of the alterations. This knowledge has collectively led us to two conclusions-the consequences of intensive human influence on the nitrogen cycle leads to a cascade of ecosystem and human effects which need to be managed. Secondly, the management is complicated by the facts that it not only has to be integrated, but it also has to take into account that the management should not lower the ability of managed ecosystems to produce food for the world's peoples. The framework of the nitrogen cascade provides us with a structure for better identifying intervention points, and more effective policies, technologies and measures to prevent or mitigate the adverse impacts of reactive nitrogen, while enhancing its beneficial uses. We can now begin to use our understanding of science to set priorities and craft new policy strategies. For many regions of the world, the science is strong enough to manage nitrogen and there are existing tools to do so. However, the tools are not integrated, critical tools are missing and most importantly, there are nitrogen-rich regions of the world where the science is lacking, and nitrogen-poor regions

  5. Three-beam double stimulated Raman scatterings: Cascading configuration

    Science.gov (United States)

    Rao, B. Jayachander; Cho, Minhaeng

    2018-03-01

    Two-beam stimulated Raman scattering (SRS) has been used in diverse label-free spectroscopy and imaging applications of live cells, biological tissues, and functional materials. Recently, we developed a theoretical framework for the three-beam double SRS processes that involve pump, Stokes, and depletion beams, where the pump-Stokes and pump-depletion SRS processes compete with each other. It was shown that the net Stokes gain signal can be suppressed by increasing the depletion beam intensity. The theoretical prediction has been experimentally confirmed recently. In the previous scheme for a selective suppression of one SRS by making it compete with another SRS, the two SRS processes occur in a parallel manner. However, there is another possibility of three-beam double SRS scheme that can be of use to suppress either Raman gain of the Stokes beam or Raman loss of the pump beam by depleting the Stokes photons with yet another SRS process induced by the pair of Stokes and another (second) Stokes beam. This three-beam double SRS process resembles a cascading energy transfer process from the pump beam to the first Stokes beam (SRS-1) and subsequently from the first Stokes beam to the second Stokes beam (SRS-2). Here, the two stimulated Raman gain-loss processes are associated with two different Raman-active vibrational modes of solute molecule. In the present theory, both the radiation and the molecules are treated quantum mechanically. We then show that the cascading-type three-beam double SRS can be described by coupled differential equations for the photon numbers of the pump and Stokes beams. From the approximate solutions as well as exact numerical calculation results for the coupled differential equations, a possibility of efficiently suppressing the stimulated Raman loss of the pump beam by increasing the second Stokes beam intensity is shown and discussed. To further prove a potential use of this scheme for developing a super-resolution SRS microscopy, we

  6. Scaling laws for soliton pulse compression by cascaded quadratic nonlinearities (vol 24, pg 2752, 2007)

    DEFF Research Database (Denmark)

    Bache, Morten; Moses, J.; Wise, F.W.

    2010-01-01

    Erratum for [M. Bache, J. Moses, and F. W. Wise, "Scaling laws for soliton pulse compression by cascaded quadratic nonlinearities," J. Opt. Soc. Am. B 24, 2752-2762 (2007)].......Erratum for [M. Bache, J. Moses, and F. W. Wise, "Scaling laws for soliton pulse compression by cascaded quadratic nonlinearities," J. Opt. Soc. Am. B 24, 2752-2762 (2007)]....

  7. Distributed monitoring for the prevention of cascading failures in operational power grids

    NARCIS (Netherlands)

    M.E. Warnier (Martijn); S.O. Dulman (Stefan); Y. Koç (Yakup); E.J. Pauwels (Eric)

    2017-01-01

    textabstractElectrical power grids are vulnerable to cascading failures that can lead to large blackouts. The detection and prevention of cascading failures in power grids are important problems. Currently, grid operators mainly monitor the states (loading levels) of individual components in a power

  8. A cross-scale trophic cascade from large predatory fish to algae in coastal ecosystems

    NARCIS (Netherlands)

    Donadi, S.; Austin, A. N.; Bergstrom, U.; Eriksson, B. K.; Hansen, J. P.; Jacobson, P.; Sundblad, G.; van Regteren, M.; Eklof, J. S.

    2017-01-01

    Trophic cascades occur in many ecosystems, but the factors regulating them are still elusive. We suggest that an overlooked factor is that trophic interactions (TIs) are often scale-dependent and possibly interact across spatial scales. To explore the role of spatial scale for trophic cascades, and

  9. Meadow contraction and extinction debt in meadow plants and moths in the Western Cascades

    Science.gov (United States)

    Meadows in the western Cascades have contracted and fragmented by approximately 50% in the past 60 years. These habitats occupy only about 5% of the landscape of the western Cascades but are important for the preservation of biodiversity and rare species. This habitat loss and ...

  10. Molecular-dynamics simulation of displacement cascades in Cu: analysis of replacement sequences

    International Nuclear Information System (INIS)

    King, W.E.; Benedek, R.

    1981-01-01

    Molecular-dynamics computer simulations of displacement cascades in copper have been performed for recoil energies up to 450 eV. Statistical analyses of the atomic replacements are presented. Linear replacement sequence lengths are extremely short on the average. The effect of the cooling phase of the cascade is discussed

  11. Fire and water: volcanology, geomorphology, and hydrogeology of the Cascade Range, central Oregon

    Science.gov (United States)

    Katharine V. Cashman; Natalia I. Deligne; Marshall W. Gannett; Gordon E. Grant; Anne. Jefferson

    2009-01-01

    This field trip guide explores the interactions among the geologic evolution, hydrology, and fluvial geomorphology of the central Oregon Cascade Range. Key topics include the geologic control of hydrologic regimes on both the wet and dry sides of the Cascade Range crest, groundwater dynamics and interaction between surface and groundwater in young volcanic arcs, and...

  12. Assessing wood use efficiency and greenhouse gas emissions of wood product cascading in the European Union

    NARCIS (Netherlands)

    Bais-Moleman, A.L.; Sikkema, Richard; Vis, Martijn; Reumerman, Patrick; Theurl, Michaela; Erb, Karl Heinz

    2017-01-01

    Cascading use of biomass is a recognized strategy contributing to an efficient development of the bioeconomy and for mitigating climate change. This study aims at assessing the potential of cascading use of woody biomass for reducing GHG (greenhouse gas) emissions and increasing the overall wood

  13. Multiobjective reservoir operating rules based on cascade reservoir input variable selection method

    Science.gov (United States)

    Yang, Guang; Guo, Shenglian; Liu, Pan; Li, Liping; Xu, Chongyu

    2017-04-01

    The input variable selection in multiobjective cascade reservoir operation is an important and difficult task. To address this problem, this study proposes the cascade reservoir input variable selection (CIS) method that searches for the most valuable input variables for decision making in multiple-objectivity cascade reservoir operations. From a case study of Hanjiang cascade reservoirs in China, we derive reservoir operating rules based on the combination of CIS and Gaussian radial basis functions (RBFs) methods and optimize the rules through Pareto-archived dynamically dimensioned search (PA-DDS) with two objectives: to maximize both power generation and water supply. We select the most effective input variables and evaluate their impacts on cascade reservoir operations. From the simulated trajectories of reservoir water level, power generation, and water supply, we analyze the multiobjective operating rules with several input variables. The results demonstrate that the CIS method performs well in the selection of input variables for the cascade reservoir operation, and the RBFs method can fully express the nonlinear operating rules for cascade reservoirs. We conclude that the CIS method is an effective and stable approach to identifying the most valuable information from a large number of candidate input variables. While the reservoir storage state is the most valuable information for the Hanjiang cascade reservoir multiobjective operation, the reservoir inflow is the most effective input variable for the single-objective operation of Danjiangkou.

  14. The Utrecht 850 kV cascade generator I. Beam deflection and energy control

    NARCIS (Netherlands)

    Braams, C.M.; Smith, P.B.

    The beam deflection magnet and energy control system of the Utrecht cascade generator are described. The uniform-field magnet has entrance and exit slits located outside the magnetic held. Since the cascade generator produces a vertical beam, the most convenient choice for the angle of deflection

  15. A topological investigation of phase transitions of cascading failures in power grids

    NARCIS (Netherlands)

    Koç, Y.; Warnier, M.; Mieghem, P. van; Kooij, R.E.; Brazier, F.M.T.

    2014-01-01

    Cascading failures are one of the main reasons for blackouts in electric power transmission grids. The economic cost of such failures is in the order of tens of billion dollars annually. The loading level of power system is a key aspect to determine the amount of the damage caused by cascading

  16. Effect of collision cascades on dislocations in tungsten: A molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Fu, B.Q., E-mail: bqfu@scu.edu.cn [Key Laboratory for Radiation Physics and Technology, Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610065 (China); Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Fitzgerald, S.P. [Department of Applied Mathematics, University of Leeds, Leeds LS2 9JT (United Kingdom); Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Hou, Q.; Wang, J.; Li, M. [Key Laboratory for Radiation Physics and Technology, Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610065 (China)

    2017-02-15

    Highlights: • A cascde near a dislocation promotes climb motion. • Kinks induced by cascade facilitate the dipoles motion toward the cascade. • Shearing of dipole is dependent on PKA energy, position, direction, and dipole width. - Abstract: Tungsten (W) is the prime candidate material for the divertor and other plasma-facing components in DEMO. The point defects (i.e. vacancies and self-interstitials) produced in collision cascades caused by incident neutrons aggregate into dislocation loops (and voids), which strongly affect the mechanical properties. The point defects also interact with existing microstructural features, and understanding these processes is crucial for modelling the long term microstructural evolution of the material under fusion conditions. In this work, we performed molecular dynamics simulations of cascades interacting with initially straight edge dislocation dipoles. It was found that the residual vacancy number usually exceeds the residual interstitial number for cascades interacting with vacancy type dipoles, but for interstitial type dipoles these are close. We observed that a cascade near a dislocation promotes climb, i.e. it facilitates the movement of point defects along the climb direction. We also observed that the dislocations move easily along the glide direction, and that kinks are formed near the centre of the cascade, which then facilitate the movement of the dipoles. Some dipoles are sheared off by the cascade, and this is dependent on PKA energy, position, direction, and the width of dipole.

  17. Fabrication of a novel cascade high-pressure electro-osmotic pump.

    Science.gov (United States)

    Zhang, Feifang; Wang, Rong; Han, Tingting; Yang, Bingcheng; Liang, Xinmiao

    2011-07-07

    A novel cascade electro-osmotic pump (EOP) has been fabricated by alternately connecting a cation monolithic column and anion monolithic column in series. In this manner, the change of electric polarity between each stage of the cascade EOP is easily achieved and the pressure output of the EOP could be greatly enhanced without increase of the applied voltage.

  18. CFD analysis of cascade effects in marine propellers with trailing edge modification

    DEFF Research Database (Denmark)

    Shin, Keun Woo; Andersen, Poul

    2015-01-01

    Propeller blades are different from a single hydrofoilin isolation due to cascade effects that blades mutually affect hydrodynamic characteristics of each other in proximity. Propeller design programs based lifting-line theory and blade element momentum theory take into account cascade effect by ...

  19. Developmental Cascade Model for Adolescent Substance Use from Infancy to Late Adolescence

    Science.gov (United States)

    Eiden, Rina D.; Lessard, Jared; Colder, Craig R.; Livingston, Jennifer; Casey, Meghan; Leonard, Kenneth E.

    2016-01-01

    A developmental cascade model for adolescent substance use beginning in infancy was examined in a sample of children with alcoholic and nonalcoholic parents. The model examined the role of parents' alcohol diagnoses, depression and antisocial behavior in a cascading process of risk via 3 major hypothesized pathways: first, via parental…

  20. Turbulence Amplification with Incidence at the Leading Edge of a Compressor Cascade

    Directory of Open Access Journals (Sweden)

    Garth V. Hobson

    1999-01-01

    Full Text Available Detailed measurements, with a two-component laser-Doppler velocimeter and a thermal anemometer were made near the suction surface leading edge of controlled-diffusion airfoils in cascade. The Reynolds number was near 700,000, Mach number equal to 0.25, and freestream turbulence was at 1.5% ahead of the cascade.

  1. Estimation of LOCA break size using cascaded Fuzzy neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Geon Pil; Yoo, Kwae Hwan; Back, Ju Hyun; Na, Man Gyun [Dept. of Nuclear Engineering, Chosun University, Gwangju (Korea, Republic of)

    2017-04-15

    Operators of nuclear power plants may not be equipped with sufficient information during a loss-of-coolant accident (LOCA), which can be fatal, or they may not have sufficient time to analyze the information they do have, even if this information is adequate. It is not easy to predict the progression of LOCAs in nuclear power plants. Therefore, accurate information on the LOCA break position and size should be provided to efficiently manage the accident. In this paper, the LOCA break size is predicted using a cascaded fuzzy neural network (CFNN) model. The input data of the CFNN model are the time-integrated values of each measurement signal for an initial short-time interval after a reactor scram. The training of the CFNN model is accomplished by a hybrid method combined with a genetic algorithm and a least squares method. As a result, LOCA break size is estimated exactly by the proposed CFNN model.

  2. Deep Feature Learning and Cascaded Classifier for Large Scale Data

    DEFF Research Database (Denmark)

    Prasoon, Adhish

    from data rather than having a predefined feature set. We explore deep learning approach of convolutional neural network (CNN) for segmenting three dimensional medical images. We propose a novel system integrating three 2D CNNs, which have a one-to-one association with the xy, yz and zx planes of 3D......This thesis focuses on voxel/pixel classification based approaches for image segmentation. The main application is segmentation of articular cartilage in knee MRIs. The first major contribution of the thesis deals with large scale machine learning problems. Many medical imaging problems need huge...... amount of training data to cover sufficient biological variability. Learning methods scaling badly with number of training data points cannot be used in such scenarios. This may restrict the usage of many powerful classifiers having excellent generalization ability. We propose a cascaded classifier which...

  3. Complements and the Wound Healing Cascade: An Updated Review

    Directory of Open Access Journals (Sweden)

    Hani Sinno

    2013-01-01

    Full Text Available Wound healing is a complex pathway of regulated reactions and cellular infiltrates. The mechanisms at play have been thoroughly studied but there is much still to learn. The health care system in the USA alone spends on average 9 billion dollars annually on treating of wounds. To help reduce patient morbidity and mortality related to abnormal or prolonged skin healing, an updated review and understanding of wound healing is essential. Recent works have helped shape the multistep process in wound healing and introduced various growth factors that can augment this process. The complement cascade has been shown to have a role in inflammation and has only recently been shown to augment wound healing. In this review, we have outlined the biology of wound healing and discussed the use of growth factors and the role of complements in this intricate pathway.

  4. Analysis of car-following model with cascade compensation strategy

    Science.gov (United States)

    Zhu, Wen-Xing; Zhang, Li-Dong

    2016-05-01

    Cascade compensation mechanism was designed to improve the dynamical performance of traffic flow system. Two compensation methods were used to study unit step response in time domain and frequency characteristics with different parameters. The overshoot and phase margins are proportional to the compensation parameter in an underdamped condition. Through the comparison we choose the phase-lead compensation method as the main strategy in suppressing the traffic jam. The simulations were conducted under two boundary conditions to verify the validity of the compensator. The conclusion can be drawn that the stability of the system is strengthened with increased phase-lead compensation parameter. Moreover, the numerical simulation results are in good agreement with analytical results.

  5. Wnt Signaling Cascades and the Roles of Syndecan Proteoglycans

    DEFF Research Database (Denmark)

    Pataki, Csilla A; Couchman, John R; Brábek, Jan

    2015-01-01

    Wnt signaling comprises a group of pathways emanating from the extracellular environment through cell-surface receptors into the intracellular milieu. Wnt signaling cascades can be divided into two main branches, the canonical/β-catenin pathway and the non-canonical pathways containing the Wnt....../planar cell polarity and Wnt/calcium signaling. Syndecans are type I transmembrane proteoglycans with a long evolutionary history, being expressed in all Bilateria and in almost all cell types. Both Wnt pathways have been extensively studied over the past 30 years and shown to have roles during development...... and in a multitude of diseases. Although the first evidence for interactions between syndecans and Wnts dates back to 1997, the number of studies connecting these pathways is low, and many open questions remained unanswered. In this review, syndecan's involvement in Wnt signaling pathways as well as some...

  6. Qualification of quantum cascade lasers for space environments

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Tanya L.; Cannon, Bret D.; Brauer, Carolyn S.; Crowther, Blake; Hansen, Stewart

    2014-06-11

    Laser-based instruments are enabling a new generation of scientific instruments for space environments such as those used in the exploration of Mars. The lasers must be robust and able to withstand the harsh environment of space, including radiation exposure. Quantum cascade lasers (QCLs), which are semiconductor lasers that emit in the infrared spectral region, offer the potential for the development of novel laser-based instruments for space applications. The performance of QCLs after radiation exposure, however, has not been reported. We report on work to quantify the performance of QCLs after exposure to two different radiation sources, 64 MeV protons and Cobalt-60 gamma rays, at radiation levels likely to be encountered during a typical space flight mission. No significant degradation in threshold current or slope efficiency is observed for any of the seven Fabry-Perot QCLs that are tested.

  7. Coalescence cascade of dissipative solitons in parametrically driven systems

    Science.gov (United States)

    Clerc, M. G.; Coulibaly, S.; Gordillo, L.; Mujica, N.; Navarro, R.

    2011-09-01

    Parametrically driven spatially extended systems exhibit uniform oscillations which are modulationally unstable. The resulting periodic state evolves to the creation of a gas of dissipative solitons. Driven by the interaction of dissipative solitons, the multisoliton state undergoes a cascade of coalescence processes, where the average soliton separation distance obeys a temporal self-similar law. Starting from the soliton pair interaction law, we have derived analytically and characterized the law of this multisoliton coarsening process. A comparison of numerical results obtained with different models such as the parametrically driven damped nonlinear Schrödinger equation, a vertically driven chain of pendula, and a parametrically forced magnetic wire, shows remarkable agreement. Both phenomena, the pair interaction law and the coarsening process, are also observed experimentally in a quasi-one-dimensional layer of Newtonian fluid which is oscillated vertically.

  8. Free-space communication based on quantum cascade laser

    International Nuclear Information System (INIS)

    Liu Chuanwei; Zhai Shenqiang; Zhang Jinchuan; Zhou Yuhong; Jia Zhiwei; Liu Fengqi; Wang Zhanguo

    2015-01-01

    A free-space communication based on a mid-infrared quantum cascade laser (QCL) is presented. A room-temperature continuous-wave distributed-feedback (DFB) QCL combined with a mid-infrared detector comprise the basic unit of the communication system. Sinusoidal signals at a highest frequency of 40 MHz and modulated video signals with a carrier frequency of 30 MHz were successfully transmitted with this experimental setup. Our research has provided a proof-of-concept demonstration of space optical communication application with QCL. The highest operation frequency of our setup was determined by the circuit-limited modulation bandwidth. A high performance communication system can be obtained with improved modulation circuit system. (paper)

  9. High efficiency heat transport and power conversion system for cascade

    International Nuclear Information System (INIS)

    Maya, I.; Bourque, R.F.; Creedon, R.L.; Schultz, K.R.

    1985-02-01

    The Cascade ICF reactor features a flowing blanket of solid BeO and LiAlO 2 granules with very high temperature capability (up to approx. 2300 K). The authors present here the design of a high temperature granule transport and heat exchange system, and two options for high efficiency power conversion. The centrifugal-throw transport system uses the peripheral speed imparted to the granules by the rotating chamber to effect granule transport and requires no additional equipment. The heat exchanger design is a vacuum heat transfer concept utilizing gravity-induced flow of the granules over ceramic heat exchange surfaces. A reference Brayton power cycle is presented which achieves 55% net efficiency with 1300 K peak helium temperature. A modified Field steam cycle (a hybrid Rankine/Brayton cycle) is presented as an alternate which achieves 56% net efficiency

  10. Cascaded adaptive control of ocean vehicles with significant actuator dynamics

    Directory of Open Access Journals (Sweden)

    Thor I. Fossen

    1994-04-01

    Full Text Available This paper presents a cascade adaptive control scheme for marine vehicles where the non-linear equations of motion include a model of the actuator dynamics. The adaptive controller does not require the parameters of the vehicle dynamics and the actuator time constants to be known a priori. Both the velocity and position tracking errors are shown to converge to zero by applying Barbalat's lemma. Global asymptotic stability is proven for the velocity scheme while the position/attitude controller is only proven to be convergent. Furthermore, all parameter estimates are shown to be bounded. Computer simulations of an ROV speed control system and an autopilot for automatic ship steering are used to illustrate the design methodology.

  11. Discerning supersymmetry in adjacent branch cascade decay correlations

    Energy Technology Data Exchange (ETDEWEB)

    Graesser, Michael [Los Alamos National Laboratory; Shelton, Jessie [RUTGERS; Thomas, Scott [RUTGERS

    2008-01-01

    Many models of new physics have mass spectra that lead to production of new coloured particles which decay through long decay chains into a number of quarks and leptons. It is known that invariant mass distributions formed from the visible fermion four-momenta depend on the physical properties of intermediate particles, such as their spin, mass, chiral couplings and other interactions. Here it is emphasized that correlations between these distributions provides useful checks and tests on the underlying model and its theoretical assumptions. This is illustrated in supersymmetric models having cascade decays producing leptons, including taus. Moreover, such correlations can provide evidence on whether the symmetry stabilizing the lightest superpartner is discrete, continuous or approximately continuous. The richer phenomenology of third generation superpartners, and their interactions with neutralinos and charginos, can with sufficient luminosity be investigated with di-fermion distributions involving taus and/or signed b-quarks.

  12. Geothermal gradient drilling, north-central Cascades of Oregon, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Youngquist, W.

    1980-01-01

    A geothermal gradient drilling program was conducted on the western flank of the north-central Cascade Mountains in Oregon. Six wells were drilled during this program, although in effect seven were drilled, as two wells were drilled at site 3, the second well, however, actually going to a lesser depth than the first. Three of the wells (3, 4, and 5) were drilled in areas which topographically are subject to strong throughflows of ground water. None of these wells reached the regional water table, and all showed essentially isothermal geothermal gradients. The single well which was started essentially at the water table (well 6) shows a linear temperature rise with depth essentially from the top of the well bore. Well No. 2 shows an isothermal gradient down to the level of the regional water table and then shows a linear gradient of about 70/sup 0/C/km from the regional water table to total depth.

  13. Double-Cascade Events from New Physics in Icecube

    Science.gov (United States)

    Coloma, Pilar; Machado, Pedro A. N.; Martinez-Soler, Ivan; Shoemaker, Ian M.

    2017-11-01

    A variety of new physics models allows for neutrinos to up-scatter into heavier states. If the incident neutrino is energetic enough, the heavy neutrino may travel some distance before decaying. In this work, we consider the atmospheric neutrino flux as a source of such events. At IceCube, this would lead to a "double-bang" (DB) event topology, similar to what is predicted to occur for tau neutrinos at ultrahigh energies. The DB event topology has an extremely low background rate from coincident atmospheric cascades, making this a distinctive signature of new physics. Our results indicate that IceCube should already be able to derive new competitive constraints on models with GeV-scale sterile neutrinos using existing data.

  14. Recondensation of vaporized material in the Cascade ICF reactor

    International Nuclear Information System (INIS)

    Hogan, W.J.; Peterson, R.R.

    1985-01-01

    In the Cascade inertial fusion reactor, the innermost blanket zone consists of solid granules of C or BeO. The x rays from a fusion pulse of 300 MJ will vaporize up to 1 kg of material. The temperature of this vaporized material may reach 1 to 2 electron volts. The CONRAD code was used to calculate the energy and mass exchange between this hot plasma and the cold wall until complete recondensation of the material reduces the chamber particle density to 3 x 10 15 cm -3 , which is required for propagation of the next laser pulse. Our calculations indicate that recondensation times are in the few to tens of milliseconds range even if only the first layer of granules is available for recondensation. Gas flow calculations indicate that several layers of granules should be available for recondensation. We discuss phenomenology, not currently in the CONRAD model, that could lead to increased recondensation times. 17 refs., 5 figs

  15. A cascade method for TFT-LCD defect detection

    Science.gov (United States)

    Yi, Songsong; Wu, Xiaojun; Yu, Zhiyang; Mo, Zhuoya

    2017-07-01

    In this paper, we propose a novel cascade detection algorithm which focuses on point and line defects on TFT-LCD. At the first step of the algorithm, we use the gray level difference of su-bimage to segment the abnormal area. The second step is based on phase only transform (POT) which corresponds to the Discrete Fourier Transform (DFT), normalized by the magnitude. It can remove regularities like texture and noise. After that, we improve the method of setting regions of interest (ROI) with the method of edge segmentation and polar transformation. The algorithm has outstanding performance in both computation speed and accuracy. It can solve most of the defect detections including dark point, light point, dark line, etc.

  16. Radiative distortion of kinematic edges in cascade decays

    Directory of Open Access Journals (Sweden)

    M. Beneke

    2017-07-01

    Full Text Available Kinematic edges of cascade decays of new particles produced in high-energy collisions may provide important constraints on the involved particles' masses. For the exemplary case of gluino decay g˜→qq¯χ˜ into a pair of quarks and a neutralino through a squark resonance, we study the hadronic invariant mass distribution in the vicinity of the kinematic edge. We perform a next-to-leading order calculation in the strong coupling αs and the ratio of squark width and squark mass Γq˜/mq˜, based on a systematic expansion in Γq˜/mq˜. The separation into hard, collinear and soft contributions elucidates the process-dependent and universal features of distributions in the edge region, represented by on-shell decay matrix elements, universal jet functions and a soft function that depends on the resonance propagator and soft Wilson lines.

  17. Organocatalytic cascade reactions as a new tool in total synthesis

    Science.gov (United States)

    Grondal, Christoph; Jeanty, Matthieu; Enders, Dieter

    2010-03-01

    The total synthesis of natural products and biologically active compounds, such as pharmaceuticals and agrochemicals, has reached an extraordinary level of sophistication. We are, however, still far away from the 'ideal synthesis' and the state of the art is still frequently hampered by lengthy protecting-group strategies and costly purification procedures derived from the step-by-step protocols. In recent years several new criteria have been brought forward to solve these problems and to improve total synthesis: atom, step and redox economy or protecting-group-free synthesis. Over the past decade the research area of organocatalysis has rapidly grown to become a third pillar of asymmetric catalysis standing next to metal and biocatalysis, thus paving the way for a new and powerful strategy that can help to address these issues - organocatalytic cascade reactions. In this Review we present the first applications of such asymmetric organocascade reactions to the total synthesis of natural products.

  18. Interband cascade (IC) photovoltaic (PV) architecture for PV devices

    Science.gov (United States)

    Yang, Rui Q.; Tian, Zhaobing; Mishima, Tetsuya D.; Santos, Michael B.; Johnson, Matthew B.; Klem, John F.

    2015-10-20

    A photovoltaic (PV) device, comprising a PV interband cascade (IC) stage, wherein the IC PV stage comprises an absorption region with a band gap, the absorption region configured to absorb photons, an intraband transport region configured to act as a hole barrier, and an interband tunneling region configured to act as an electron barrier. An IC PV architecture for a photovoltaic device, the IC PV architecture comprising an absorption region, an intraband transport region coupled to the absorption region, and an interband tunneling region coupled to the intraband transport region and to the adjacent absorption region, wherein the absorption region, the intraband transport region, and the interband tunneling region are positioned such that electrons will flow from the absorption region to the intraband transport region to the interband tunneling region.

  19. Some time dependent aspects of fast neutron induced atomic cascades

    International Nuclear Information System (INIS)

    Williams, M.M.R.

    1976-01-01

    Analytical results are obtained for the time-energy distribution of neutrons and the associated displaced atoms slowing down in an amorphous medium according to a general force law. Explicit results are given for the inverse power law, and applications to hard-sphere and Coulomb scattering are discussed. Complete results are obtained for the steady state energy distribution of particles arising from a primary knock-on, and from a neutron initiated cascade. The speed of the slowing down process is assessed by calculating the slowing down time of particles. Two different concepts of slowing down time are discussed, one based upon a density average and the other on a slowing down density average. It is shown that the latter definition is physically more realistic and mathematically simpler. (author)

  20. Synthesis of Cascadable DDCC-Based Universal Filter Using NAM

    Directory of Open Access Journals (Sweden)

    Huu-Duy Tran

    2015-08-01

    Full Text Available A novel systematic approach for synthesizing DDCC-based voltage-mode biquadratic universal filters is proposed. The DDCCs are described by infinity-variables’ models of nullor-mirror elements which can be used in the nodal admittance matrix expansion process. Applying the proposed method, the obtained 12 equivalent filters offer the following features: multi-input and two outputs, realization of all five standard filter functions, namely lowpass, bandpass, highpass, notch and allpass, high-input impedance, employing only grounded capacitors and resistors, orthogonal controllability between pole frequency and quality factor, and cascadable, low active and passive sensitivities. The workability of some synthesized filters is verified by HSPICE simulations to demonstrate the feasibility of the proposed method.

  1. Amyloid cascade hypothesis: Pathogenesis and therapeutic strategies in Alzheimer's disease.

    Science.gov (United States)

    Barage, Sagar H; Sonawane, Kailas D

    2015-08-01

    Alzheimer's disease is an irreversible, progressive neurodegenerative disorder. Various therapeutic approaches are being used to improve the cholinergic neurotransmission, but their role in AD pathogenesis is still unknown. Although, an increase in tau protein concentration in CSF has been described in AD, but several issues remains unclear. Extensive and accurate analysis of CSF could be helpful to define presence of tau proteins in physiological conditions, or released during the progression of neurodegenerative disease. The amyloid cascade hypothesis postulates that the neurodegeneration in AD caused by abnormal accumulation of amyloid beta (Aβ) plaques in various areas of the brain. The amyloid hypothesis has continued to gain support over the last two decades, particularly from genetic studies. Therefore, current research progress in several areas of therapies shall provide an effective treatment to cure this devastating disease. This review critically evaluates general biochemical and physiological functions of Aβ directed therapeutics and their relevance. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Integration of quantum cascade lasers and passive waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Montoya, Juan, E-mail: juan.montoya@ll.mit.edu; Wang, Christine; Goyal, Anish; Creedon, Kevin; Connors, Michael; Daulton, Jeffrey; Donnelly, Joseph; Missaggia, Leo; Aleshire, Chris; Sanchez-Rubio, Antonio; Herzog, William [MIT Lincoln Laboratory, 244 Wood St, Lexington, Massachusetts 02420 (United States)

    2015-07-20

    We report on monolithic integration of active quantum cascade laser (QCL) materials with passive waveguides formed by using proton implantation. Proton implantation reduces the electron concentration in the QCL layers by creating deep levels that trap carriers. This strongly reduces the intersubband absorption and the free-carrier absorption in the gain region and surrounding layers, thus significantly reducing optical loss. We have measured loss as low as α = 0.33 cm{sup −1} in λ = 9.6 μm wavelength proton-implanted QCL material. We have also demonstrated lasing in active-passive integrated waveguides. This simple integration technique is anticipated to enable low-cost fabrication in infrared photonic integrated circuits in the mid-infrared (λ ∼ 3–16 μm)

  3. Ultraviolet cascade in classical Yang-Mills theory

    Science.gov (United States)

    Kurkela, Aleksi; Moore, Guy D.

    2012-09-01

    We study the real-time behavior of classical Yang-Mills theory under initial conditions with nonperturbatively large, infrared field amplitudes. Our lattice study confirms the cascade of energy toward higher momenta and lower occupancy, which occurs via a scaling solution f[p,t1]=(t0/t1)(4)/(7)f[p(t0/t1)(1)/(7),t0]. Above a characteristic scale pmax⁡, f falls exponentially; below pmax⁡, f[p]∝p(-4)/(3). We find no evidence for different infrared exponents or for infrared occupancies in excess of those described by this scaling solution. We also investigate what the fate of large occupancies would be, both in the electric and the magnetic sector.

  4. Cascade Distillation System Design for Safety and Mission Assurance

    Science.gov (United States)

    Sarguisingh, Miriam; Callahan, Michael R.; Okon, Shira

    2015-01-01

    Per the NASA Human Health, Life Support and Habitation System Technology Area 06 report "crewed missions venturing beyond Low-Earth Orbit (LEO) will require technologies with improved reliability, reduced mass, self-sufficiency, and minimal logistical needs as an emergency or quick-return option will not be feasible".1 To meet this need, the development team of the second generation Cascade Distillation System (CDS 2.0) chose a development approach that explicitly incorporate consideration of safety, mission assurance, and autonomy. The CDS 2.0 preliminary design focused on establishing a functional baseline that meets the CDS core capabilities and performance. The critical design phase is now focused on incorporating features through a deliberative process of establishing the systems failure modes and effects, identifying mitigation strategies, and evaluating the merit of the proposed actions through analysis and test. This paper details results of this effort on the CDS 2.0 design.

  5. Terahertz Quantum Cascade Laser With Efficient Coupling and Beam Profile

    Science.gov (United States)

    Chattopadhyay, Goutam; Kawamura, Jonathan H.; Lin, Robert H.; Williams, Benjamin

    2012-01-01

    Quantum cascade lasers (QCLs) are unipolar semiconductor lasers, where the wavelength of emitted radiation is determined by the engineering of quantum states within the conduction band in coupled multiple-quantum-well heterostructures to have the desired energy separation. The recent development of terahertz QCLs has provided a new generation of solid-state sources for radiation in the terahertz frequency range. Terahertz QCLs have been demonstrated from 0.84 to 5.0 THz both in pulsed mode and continuous wave mode (CW mode). The approach employs a resonant-phonon depopulation concept. The metal-metal (MM) waveguide fabrication is performed using Cu-Cu thermo-compression bonding to bond the GaAs/AlGaAs epitaxial layer to a GaAs receptor wafer.

  6. Single-Mode, Distributed Feedback Interband Cascade Lasers

    Science.gov (United States)

    Frez, Clifford F. (Inventor); Borgentun, Carl E. (Inventor); Briggs, Ryan M. (Inventor); Bagheri, Mahmood (Inventor); Forouhar, Siamak (Inventor)

    2016-01-01

    Single-mode, distributed feedback interband cascade lasers (ICLs) using distributed-feedback gratings (e.g., lateral Bragg gratings) and methods of fabricating such ICLs are provided. The ICLs incorporate distributed-feedback gratings that are formed above the laser active region and adjacent the ridge waveguide (RWG) of the ICL. The ICLs may incorporate a double-ridge system comprising an optical confinement structure (e.g., a RWG) disposed above the laser active region that comprises the first ridge of the double ridge system, a DFB grating (e.g., lateral Bragg grating) disposed above the laser active region and adjacent the optical confinement structure, and an electric confinement structure that passes at least partially through the laser active region and that defines the boundary of the second ridge comprises and the termination of the DFB grating.

  7. Nonequilibrium phonon effects in midinfrared quantum cascade lasers

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Y. B., E-mail: yshi9@wisc.edu; Knezevic, I., E-mail: knezevic@engr.wisc.edu [Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706-1691 (United States)

    2014-09-28

    We investigate the effects of nonequilibrium phonon dynamics on the operation of a GaAs-based midinfrared quantum cascade laser over a range of temperatures (77–300 K) via a coupled ensemble Monte Carlo simulation of electron and optical-phonon systems. Nonequilibrium phonon effects are shown to be important below 200 K. At low temperatures, nonequilibrium phonons enhance injection selectivity and efficiency by drastically increasing the rate of interstage electron scattering from the lowest injector state to the next-stage upper lasing level via optical-phonon absorption. As a result, the current density and modal gain at a given field are higher and the threshold current density lower and considerably closer to experiment than results obtained with thermal phonons. By amplifying phonon absorption, nonequilibrium phonons also hinder electron energy relaxation and lead to elevated electronic temperatures.

  8. Phosphoinositolphosphate (PIP) cascade induction by hypertonic stress of plant tissue

    International Nuclear Information System (INIS)

    Srivastava, A.; Jacoby, B.

    1989-01-01

    Inositol 1,4,5-trisphosphate (IP 3 ) was determined by competition with [ 3 H]-IP 3 for binding to an IP 3 specific protein. A hypertonic mannitol, sorbitol or lactose shock induced an increase in the rate of K + uptake and raised the IP 3 content of Beta vulgaris slices, excised Vigna mungo and Sorghum bicolor roots, as well as attached V. mungo roots. Increased K + uptake could also be induced by compounds that artificially induce the PIP cascade, or mimic it's products. A hypertonic shock, administered to intact B. vulgaris slices, further enhanced the phosphorylation of a 20 kD protein in the plasmalemma. Maximal IP 3 content was found 10 min after hypertonic induction and maximal K + uptake was obtained 10 min later. The effect of a continuous hypertonic treatment on IP 3 content, but not on K + uptake, was transient. Li + decreased the rate of IP 3 metabolism

  9. Numerical simulation of steady and unsteady flows through plane cascades

    Science.gov (United States)

    Fořt, J.; Huněk, M.; Kozel, K.; Lain, J.; Šejna, M.; Vavřincová, M.

    This paper of a few co-authors presents some works of the group of the Department of Technical Mathematics, Faculty of Mechanical Eng., TU Prague, which deals with numerical methods in fluid dynamics. We present numerical methods for a solution of different physical and mathematical models of flow through plane cascades. We use the Mac Cormack's scheme, Ron — Ho — Ni's scheme and Runge — Kutta schemes on H — type structured grid and upwind schemes on an unstructured triangular grid. This methods are used for simulation of steady or unsteady inviscid flow and for simulation of viscous laminar flow. We deal with comparison of different methods mutually and with experimental data and with comparison of different physical and mathematical models of flow used for numerical simulation.

  10. Double-Cascade Events from New Physics in Icecube.

    Science.gov (United States)

    Coloma, Pilar; Machado, Pedro A N; Martinez-Soler, Ivan; Shoemaker, Ian M

    2017-11-17

    A variety of new physics models allows for neutrinos to up-scatter into heavier states. If the incident neutrino is energetic enough, the heavy neutrino may travel some distance before decaying. In this work, we consider the atmospheric neutrino flux as a source of such events. At IceCube, this would lead to a "double-bang" (DB) event topology, similar to what is predicted to occur for tau neutrinos at ultrahigh energies. The DB event topology has an extremely low background rate from coincident atmospheric cascades, making this a distinctive signature of new physics. Our results indicate that IceCube should already be able to derive new competitive constraints on models with GeV-scale sterile neutrinos using existing data.

  11. Development of the cascade inertial-confinement-fusion reactor

    International Nuclear Information System (INIS)

    Pitts, J.H.

    1985-01-01

    Caqscade, originally conceived as a football-shaped, steel-walled reactor containing a Li 2 O granule blanket, is now envisaged as a double-cone-shaped reactor containing a two-layered (three-zone) flowing blanket of BeO and LiAlO 2 granules. Average blanket exit temperature is 1670 K and gross plant efficiency (net thermal conversion efficiency) using a Brayton cycle is 55%. The reactor has a low-activation SiC-tiled wall. It rotates at 50 rpm, and the granules are transported to the top of the heat exchanger using their peripheral speed; no conveyors or lifts are required. The granules return to the reactor by gravity. After considerable analysis and experimentation, we continue to regard Cascade as a promising reactor concept with the advantages of safety, efficiency, and low activation

  12. Deep Feature Learning and Cascaded Classifier for Large Scale Data

    DEFF Research Database (Denmark)

    Prasoon, Adhish

    from data rather than having a predefined feature set. We explore deep learning approach of convolutional neural network (CNN) for segmenting three dimensional medical images. We propose a novel system integrating three 2D CNNs, which have a one-to-one association with the xy, yz and zx planes of 3D...... image, respectively and this system is referred as triplanar convolutional neural network in the thesis. We applied the triplanar CNN for segmenting articular cartilage in knee MRI and compared its performance with the same state-of-the-art method which was used as a benchmark for cascaded classifier...... contextualized convolutional neural network (SCCNN) which incorporates the labels of the neighbouring pixels/voxels while training the network. We demonstrate its application for the 2D problem of segmenting horses from the Weizmann horses database using 2D CNN and our 3D problem of segmenting tibial cartilage...

  13. Euler flow predictions for an oscillating cascade using a high resolution wave-split scheme

    Science.gov (United States)

    Huff, Dennis L.; Swafford, Timothy W.; Reddy, T. S. R.

    1991-01-01

    A compressible flow code that can predict the nonlinear unsteady aerodynamic associated with transonic flows over oscillating cascades is developed and validated. The code solves the two dimensional, unsteady Euler equations using a time-marching, flux-difference splitting scheme. The unsteady pressures and forces can be determined for arbitrary input motions, although only harmonic pitching and plunging motions are addressed. The code solves the flow equations on a H-grid which is allowed to deform with the airfoil motion. Predictions are presented for both flat plate cascades and loaded airfoil cascades. Results are compared to flat plate theory and experimental data. Predictions are also presented for several oscillating cascades with strong normal shocks where the pitching amplitudes, cascade geometry and interblade phase angles are varied to investigate nonlinear behavior.

  14. Space partitioning strategies for indoor WLAN positioning with cascade-connected ANN structures.

    Science.gov (United States)

    Borenović, Miloš; Nešković, Aleksandar; Budimir, Djuradj

    2011-02-01

    Position information in indoor environments can be procured using diverse approaches. Due to the ubiquitous presence of WLAN networks, positioning techniques in these environments are the scope of intense research. This paper explores two strategies for space partitioning when utilizing cascade-connected Artificial Neural Networks (ANNs) structures for indoor WLAN positioning. A set of cascade-connected ANN structures with different space partitioning strategies are compared mutually and to the single ANN structure. The benefits of using cascade-connected ANNs structures are shown and discussed in terms of the size of the environment, number of subspaces and partitioning strategy. The optimal cascade-connected ANN structures with space partitioning show up to 50% decrease in median error and up to 12% decrease in the average error with respect to the single ANN model. Finally, the single ANN and the optimal cascade-connected ANN model are compared against other well-known positioning techniques.

  15. Model and Study on Cascade Control System Based on IGBT Chopping Control

    Science.gov (United States)

    Niu, Yuxin; Chen, Liangqiao; Wang, Shuwen

    2018-01-01

    Thyristor cascade control system has a wide range of applications in the industrial field, but the traditional cascade control system has some shortcomings, such as a low power factor, serious harmonic pollution. In this paper, not only analyzing its system structure and working principle, but also discussing the two main factors affecting the power factor. Chopping-control cascade control system, adopted a new power switching device IGBT, which could overcome traditional cascade control system’s two main drawbacks efficiently. The basic principle of this cascade control system is discussed in this paper and the model of speed control system is built by using MATLAB/Simulink software. Finally, the simulation results of the system shows that the system works efficiently. This system is worthy to be spread widely in engineering application.

  16. Collision cascades in HTSC [high temperature superconductors] as possible pinning centres

    International Nuclear Information System (INIS)

    Kirsanov, V.V.; Musin, N.N.; Roskin, D.G.; Shamarina, E.I.

    1993-01-01

    Computer simulation was used to study the development of collision cascades in monocrystals of YBa 2 Cu 3 O 7 , YBa 2 Cu 3 O 6.5 and YBa 2 Cu 3 O 6 which were produced by primary knock-on atoms (PKAs) during fast particle irradiation. Oxygen deficit was found to have an effect on the development of cascades in these phases, with a lowering of oxygen deficit decreasing cascade sizes. The type of PKA was observed to influence the geometry of a cascade. When heavy PKAs form a cascade, the oxygen sublattice is practically undisturbed, with very little disorder; while with oxygen ions as the PKA, the main displacements fall within the oxygen subsystem. In addition, the angular dependences of the displacement threshold energy for yttrium and barium ions are given. (Author)

  17. Peak Operation of Cascaded Hydropower Plants Serving Multiple Provinces

    Directory of Open Access Journals (Sweden)

    Jianjian Shen

    2015-10-01

    Full Text Available The bulk hydropower transmission via trans-provincial and trans-regional power networks in China provides great operational flexibility to dispatch power resources between multiple power grids. This is very beneficial to alleviate the tremendous peak load pressure of most provincial power grids. This study places the focus on peak operations of cascaded hydropower plants serving multiple provinces under a regional connected AC/DC network. The objective is to respond to peak loads of multiple provincial power grids simultaneously. A two-stage search method is developed for this problem. In the first stage, a load reconstruction strategy is proposed to combine multiple load curves of power grids into a total load curve. The purpose is to deal with different load features in load magnitudes, peaks and valleys. A mutative-scale optimization method is then used to determine the generation schedules of hydropower plants. In the second stage, an exterior point search method is established to allocate the generation among multiple receiving power grids. This method produces an initial solution using the load shedding algorithm, and further improves it by iteratively coordinating the generation among different power grids. The proposed method was implemented to the operations of cascaded hydropower plants on Xin-Fu River and another on Hongshui River. The optimization results in two cases satisfied the peak demands of receiving provincial power grids. Moreover, the maximum load difference between peak and valley decreased 12.67% and 11.32% in Shanghai Power Grid (SHPG and Zhejiang Power Grid (ZJPG, exceeding by 4.85% and 6.72% those of the current operational method, respectively. The advantage of the proposed method in alleviating peak-shaving pressure is demonstrated.

  18. Applications of quantum cascade lasers in plasma diagnostics: a review

    Science.gov (United States)

    Röpcke, J.; Davies, P. B.; Lang, N.; Rousseau, A.; Welzel, S.

    2012-10-01

    Over the past few years mid-infrared absorption spectroscopy based on quantum cascade lasers operating over the region from 3 to 12 µm and called quantum cascade laser absorption spectroscopy or QCLAS has progressed considerably as a powerful diagnostic technique for in situ studies of the fundamental physics and chemistry of molecular plasmas. The increasing interest in processing plasmas containing hydrocarbons, fluorocarbons, nitrogen oxides and organo-silicon compounds has led to further applications of QCLAS because most of these compounds and their decomposition products are infrared active. QCLAS provides a means of determining the absolute concentrations of the ground states of stable and transient molecular species at time resolutions below a microsecond, which is of particular importance for the investigation of reaction kinetics and dynamics. Information about gas temperature and population densities can also be derived from QCLAS measurements. Since plasmas with molecular feed gases are used in many applications such as thin film deposition, semiconductor processing, surface activation and cleaning, and materials and waste treatment, this has stimulated the adaptation of QCLAS techniques to industrial requirements including the development of new diagnostic equipment. The recent availability of external cavity (EC) QCLs offers a further new option for multi-component detection. The aim of this paper is fourfold: (i) to briefly review spectroscopic issues arising from applying pulsed QCLs, (ii) to report on recent achievements in our understanding of molecular phenomena in plasmas and at surfaces, (iii) to describe the current status of industrial process monitoring in the mid-infrared and (iv) to discuss the potential of advanced instrumentation based on EC-QCLs for plasma diagnostics.

  19. Comprehensive integration of homogeneous bioassays via centrifugo-pneumatic cascading.

    Science.gov (United States)

    Godino, Neus; Gorkin, Robert; Linares, Ana V; Burger, Robert; Ducrée, Jens

    2013-02-21

    This work for the first time presents the full integration and automation concept for a range of bioassays leveraged by cascading a centrifugo-pneumatic valving scheme to sequentially move several liquids through shared channel segments for multi-step sample preparation into the detection zone. This novel centrifugo-pneumatic liquid handling significantly simplifies system manufacture by obviating the need for complex surface functionalization procedures or hybrid material integration, as it is common in conventional valving methods such as capillary burst valves or sacrificial valves. Based on the centrifugo-pneumatic valving scheme, this work presents a toolkit of operational elements implementing liquid loading/transfer, metering, mixing and sedimentation in a microstructured polymer disc. As a proof of concept for the broad class of homogeneous bioassays, the full integration and automation of a colorimetric nitrate/nitrite test for the detection of clinically relevant nitric oxide (NO) in whole blood is implemented. First, 40 μL of plasma is extracted from a 100 μL sample of human blood, incubated for one hour with the enzymatic mixture (60 μL), and finally reacted with 100 μL of colorimetric (Greiss) reagents. Following just a single loading phase at the beginning of the process, all of these steps are automated through the centrifugo-pneumatic cascade with a high level of flow control and synchronization. Our system shows good correlation with controls up to 50 μM of nitrate, which adequately covers the healthy human range (4 to 45.3 μM).

  20. Cascade Defect Evolution Processes: Comparison of Atomistic Methods

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Haixuan [ORNL; Stoller, Roger E [ORNL; Osetskiy, Yury N [ORNL

    2013-11-01

    Determining the defect evolution beyond the molecular dynamics (MD) time scale is critical in bridging the gap between atomistic simulations and experiments. The recently developed self-evolving atomistic kinetic Monte Carlo (SEAKMC) method provides new opportunities to simulate long-term defect evolution with MD-like fidelity. In this study, SEAKMC is applied to investigate the cascade defect evolution in bcc iron. First, the evolution of a vacancy rich region is simulated and compared with results obtained using autonomous basin climbing (ABC) +KMC and kinetic activation-relaxation technique (kART) simulations. Previously, it is found the results from kART are orders of magnitude faster than ABC+KMC. The results obtained from SEAKMC are similar to kART but the time predicted is about one order of magnitude faster than kART. The fidelity of SEAKMC is confirmed by statistically relevant MD simulations at multiple higher temperatures, which proves that the saddle point sampling is close to complete in SEAKMC. The second is the irradiation-induced formation of C15 Laves phase nano-size defect clusters. In contrast to previous studies, which claim the defects can grow by capturing self-interstitials, we found these highly stable clusters can transform to <111> glissile configuration on a much longer time scale. Finally, cascade-annealing simulations using SEAKMC is compared with traditional object KMC (OKMC) method. SEAKMC predicts substantially fewer surviving defects compared with OKMC. The possible origin of this difference is discussed and a possible way to improve the accuracy of OKMC based on SEAKMC results is outlined. These studies demonstrate the atomistic fidelity of SEAKMC in comparison with other on-the-fly KMC methods and provide new information on long-term defect evolution in iron.

  1. LNG cascading damage study. Volume I, fracture testing report.

    Energy Technology Data Exchange (ETDEWEB)

    Petti, Jason P.; Kalan, Robert J.

    2011-12-01

    As part of the liquefied natural gas (LNG) Cascading Damage Study, a series of structural tests were conducted to investigate the thermal induced fracture of steel plate structures. The thermal stresses were achieved by applying liquid nitrogen (LN{sub 2}) onto sections of each steel plate. In addition to inducing large thermal stresses, the lowering of the steel temperature simultaneously reduced the fracture toughness. Liquid nitrogen was used as a surrogate for LNG due to safety concerns and since the temperature of LN{sub 2} is similar (-190 C) to LNG (-161 C). The use of LN{sub 2} ensured that the tests could achieve cryogenic temperatures in the range an actual vessel would encounter during a LNG spill. There were four phases to this test series. Phase I was the initial exploratory stage, which was used to develop the testing process. In the Phase II series of tests, larger plates were used and tested until fracture. The plate sizes ranged from 4 ft square pieces to 6 ft square sections with thicknesses from 1/4 inches to 3/4 inches. This phase investigated the cooling rates on larger plates and the effect of different notch geometries (stress concentrations used to initiate brittle fracture). Phase II was divided into two sections, Phase II-A and Phase II-B. Phase II-A used standard A36 steel, while Phase II-B used marine grade steels. In Phase III, the test structures were significantly larger, in the range of 12 ft by 12 ft by 3 ft high. These structures were designed with more complex geometries to include features similar to those on LNG vessels. The final test phase, Phase IV, investigated differences in the heat transfer (cooling rates) between LNG and LN{sub 2}. All of the tests conducted in this study are used in subsequent parts of the LNG Cascading Damage Study, specifically the computational analyses.

  2. Amyloid cascade in Alzheimer's disease: Recent advances in medicinal chemistry.

    Science.gov (United States)

    Mohamed, Tarek; Shakeri, Arash; Rao, Praveen P N

    2016-05-04

    Alzheimer's disease is of major concern all over the world due to a number of factors including (i) an aging population (ii) increasing life span and (iii) lack of effective pharmacotherapy options. The past decade has seen intense research in discovering disease-modifying multitargeting small molecules as therapeutic options. The pathophysiology of Alzheimer's disease is attributed to a number of factors such as the cholinergic dysfunction, amyloid/tau toxicity and oxidative stress/mitochondrial dysfunction. In recent years, targeting the amyloid cascade has emerged as an attractive strategy to discover novel neurotherapeutics. Formation of beta-amyloid species, with different degrees of solubility and neurotoxicity is associated with the gradual decline in cognition leading to dementia. The two commonly used approaches to prevent beta-amyloid accumulation in the brain include (i) development of beta-secretase inhibitors and (ii) designing direct inhibitors of beta-amyloid (self-induced) aggregation. This review highlights the amyloid cascade hypothesis and the key chemical features required to design small molecules that inhibit lower and higher order beta-amyloid aggregates. Several recent examples of small synthetic molecules with disease-modifying properties were considered and their molecular docking studies were conducted using either a dimer or steric-zipper assembly of beta-amyloid. These investigations provide a mechanistic understanding on the structural requirements needed to design novel small molecules with anti-amyloid aggregation properties. Significantly, this work also demonstrates that the structural requirements to prevent aggregation of various amyloid species differs considerably, which explains the fact that many small molecules do not exhibit similar inhibition profile toward diverse amyloid species such as dimers, trimers, tetramers, oligomers, protofibrils and fibrils. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  3. An ant colony based resilience approach to cascading failures in cluster supply network

    Science.gov (United States)

    Wang, Yingcong; Xiao, Renbin

    2016-11-01

    Cluster supply chain network is a typical complex network and easily suffers cascading failures under disruption events, which is caused by the under-load of enterprises. Improving network resilience can increase the ability of recovery from cascading failures. Social resilience is found in ant colony and comes from ant's spatial fidelity zones (SFZ). Starting from the under-load failures, this paper proposes a resilience method to cascading failures in cluster supply chain network by leveraging on social resilience of ant colony. First, the mapping between ant colony SFZ and cluster supply chain network SFZ is presented. Second, a new cascading model for cluster supply chain network is constructed based on under-load failures. Then, the SFZ-based resilience method and index to cascading failures are developed according to ant colony's social resilience. Finally, a numerical simulation and a case study are used to verify the validity of the cascading model and the resilience method. Experimental results show that, the cluster supply chain network becomes resilient to cascading failures under the SFZ-based resilience method, and the cluster supply chain network resilience can be enhanced by improving the ability of enterprises to recover and adjust.

  4. Is cascade reinforcement likely when sympatric and allopatric populations exchange migrants?

    Science.gov (United States)

    Yukilevich, Roman; Aoki, Fumio

    2016-04-01

    When partially reproductively isolated species come back into secondary contact, these taxa may diverge in mating preferences and sexual cues to avoid maladaptive hybridization, a process known as reinforcement. This phenomenon often leads to reproductive character displacement (RCD) between sympatric and allopatric populations of reinforcing species that differ in their exposure to hybridization. Recent discussions have reinvigorated the idea that RCD may give rise to additional speciation between conspecific sympatric and allopatric populations, dubbing the concept "cascade reinforcement." Despite some empirical studies supporting cascade reinforcement, we still know very little about the conditions for its evolution. In the present article, we address this question by developing an individual-based population genetic model that explicitly simulates cascade reinforcement when one of the hybridizing species is split into sympatric and allopatric populations. Our results show that when sympatric and allopatric populations reside in the same environment and only differ in their exposure to maladaptive hybridization, migration between them generally inhibits the evolution of cascade by spreading the reinforcement alleles from sympatry into allopatry and erasing RCD. Under these conditions, cascade reinforcement only evolved when migration rate between sympatric and allopatric populations was very low. This indicates that stabilizing sexual selection in allopatry is generally ineffective in preventing the spread of reinforcement alleles. Only when sympatric and allopatric populations experienced divergent ecological selection did cascade reinforcement evolve in the presence of substantial migration. These predictions clarify the conditions for cascade reinforcement and facilitate our understanding of existing cases in nature.

  5. Robustness of scale-free networks with various parameters against cascading failures

    Science.gov (United States)

    Yang, Zhirou; Liu, Jing

    2018-02-01

    Many crucial real-world networks could be modeled as scale-free networks, which play an important role in the human society. Once these functional network systems suffer from cascading failures, they may lead to the malfunction of the rest part of networks. In recent years, the researches on cascading failures of scale-free networks have drawn great attention, and many studies focused on modeling the cascading phenomena and studying how to improve the robustness of networks against failures. However, the scale-free networks used in most existing studies are with fixed network parameters including scaling exponent and assortativity, which is segmentary for depicting the functionality of networked systems comprehensively. Therefore, in this paper, a series of generated scale-free networks with a certain range of parameters is adopted to evaluate the robustness against cascading failures. In addition, to make an accurate description of the ability of scale-free networks against cascading failures, we propose a link-based robustness index. The results show that influenced by the network structure, the enlargement of assortativity makes the networks weaker to resist node-based cascading failures, yet the impact on promoting link-based robustness is not clear enough. With higher scaling exponents, the tolerance of scale-free networks against link-based cascading failures decreases, however, it does not show obvious relation to node-based robustness.

  6. Molecular dynamics studies on the structural effects of displacement cascades in UO2 matrix

    International Nuclear Information System (INIS)

    Brutzel, L. Van; Rarivomanantsoa, M.; Ghaleb, D.

    2004-01-01

    A set of molecular dynamics simulations have been carried out in order to study, at the atomic scale, the ballistic damages undergo by the UO 2 matrix. The morphologies of the displacement cascades simulations initiated by an uranium atoms with a Primary Knout on Atom (PKA) energy ranges from 1 keV to 20 keV are analysed. In agreement with all the experimental results no amorphization has been found even at small scales. For the cascade initiated with a PKA energy of 20 keV several sub-cascade branches appear in many directions from the cascade core. It seems that these sub-cascades arise from a quasi channeling of uranium atoms in specific direction over long distances. However, in average the atoms are displaced no more than 2 to 3 crystallographic sites. The evolution of the Frenkel pairs with the initial energy of the PKA exhibits a power law behavior with an exponent close to 0.9 showing a discrepancy with the linear NRT law. No significant clustering of local defects such as vacancies and interstitials have been found, nevertheless vacancies are preferentially created near the core of the cascade whereas the atoms in interstitial positions are mainly located at the periphery of the sub-cascade branches. (authors)

  7. Optimization of the hydrofoil cascade and validation with quasi-analytical solution for hydraulic machinery

    Energy Technology Data Exchange (ETDEWEB)

    Frunza, T; Susan-Resiga, R [Department of Hydraulic Machinery, ' Politehnica' University of Timisoara Bv. Mihai Viteazu 1, RO-300222, Timisoara (Romania); Muntean, S; Bernad, S, E-mail: tfrunza@yahoo.co [Centre of Advanced Research in Engineering Sciences, Romanian Academy - Timisoara Branch, Bv. Mihai Viteazu 24, RO-300223, Timisoara (Romania)

    2010-08-15

    The paper presents the authors ongoing efforts to develop a robust and efficient numerical methodology, and the associated expert software, for analysis, design and optimization of hydrofoil cascades. We developed, so far, a Finite Element solver with streamfunction formulation for incompressible, inviscid and irrotational cascade flow, using a modern software infrastructure, and efficient implementation. Two test cases will be presented to evaluate the accuracy of our CASCADExpert code. In the first case, our code is tested for a thin hydrofoil cascade designed with the quasi-analytical approach. Second, the blade loading and thickness distributions obtain with our code from a given hydrofoil shape are used in an inverse design method. As a result, an optimized hydrofoil cascade is obtained. The pressure distribution on the original and optimized hydrofoil cascades is compared. We have applied the method in order to optimize the turbine and pump hydrofoil cascades, respectively. Consequently, a new method is developed in order to generate the optimized hydrofoil cascade geometry for hydraulic machinery.

  8. A new cascade NN based method to short-term load forecast in deregulated electricity market

    International Nuclear Information System (INIS)

    Kouhi, Sajjad; Keynia, Farshid

    2013-01-01

    Highlights: • We are proposed a new hybrid cascaded NN based method and WT to short-term load forecast in deregulated electricity market. • An efficient preprocessor consist of normalization and shuffling of signals is presented. • In order to select the best inputs, a two-stage feature selection is presented. • A new cascaded structure consist of three cascaded NNs is used as forecaster. - Abstract: Short-term load forecasting (STLF) is a major discussion in efficient operation of power systems. The electricity load is a nonlinear signal with time dependent behavior. The area of electricity load forecasting has still essential need for more accurate and stable load forecast algorithm. To improve the accuracy of prediction, a new hybrid forecast strategy based on cascaded neural network is proposed for STLF. This method is consists of wavelet transform, an intelligent two-stage feature selection, and cascaded neural network. The feature selection is used to remove the irrelevant and redundant inputs. The forecast engine is composed of three cascaded neural network (CNN) structure. This cascaded structure can be efficiently extract input/output mapping function of the nonlinear electricity load data. Adjustable parameters of the intelligent feature selection and CNN is fine-tuned by a kind of cross-validation technique. The proposed STLF is tested on PJM and New York electricity markets. It is concluded from the result, the proposed algorithm is a robust forecast method

  9. Atomistic simulations of displacement cascades in Y2O3 single crystal

    International Nuclear Information System (INIS)

    Dholakia, Manan; Chandra, Sharat; Valsakumar, M.C.; Mathi Jaya, S.

    2014-01-01

    Graphical abstract: (a) The averaged distortion index and the Y–O bond length of the Y 2 O 3 octahedra as a function of the simulation time for 5 keV PKA. (b) Shows the nearest neighbourhood of one of the Y ions as a function of simulation time, showing the destruction and the recovery of the YO 6 octahedron during the cascade corresponding to 5 keV Y PKA. - Highlights: • Qualitative difference in displacement cascades exists for Y and O PKA. • Nearest neighbour correlation between Y and O ions exists even at cascade peak. • Cascade core in Y 2 O 3 does not undergo melting. • Topological connectivity of YO 6 polyhedra plays important role in stability of Y 2 O 3 . - Abstract: We study the characteristics of displacement cascades in single crystal Y 2 O 3 using classical molecular dynamics. There are two possible ways to generate the cascades in yttria, using either the Y or the O atoms as the primary knock-on (PKA) atom. It is shown that there is a qualitative difference in the characteristics of the cascades obtained in these two cases. Even though the crystal is seen to be in a highly disordered state in the cascade volume, as seen from the plots of radial distribution function, the correlation between the Y and O atoms is not completely lost. This facilitates a quick recovery of the system during the annealing phase. Topological connectivity of the YO 6 polyhedral units plays an important role in imparting stability to the Y 2 O 3 crystal. These characteristics of the cascades can help explain the stability of the yttria nanoparticles when they are dispersed in oxide dispersion strengthened steels

  10. Computer simulation of electronic excitation in atomic collision cascades

    Energy Technology Data Exchange (ETDEWEB)

    Duvenbeck, A.

    2007-04-05

    The impact of an keV atomic particle onto a solid surface initiates a complex sequence of collisions among target atoms in a near-surface region. The temporal and spatial evolution of this atomic collision cascade leads to the emission of particles from the surface - a process usually called sputtering. In modern surface analysis the so called SIMS technology uses the flux of sputtered particles as a source of information on the microscopical stoichiometric structure in the proximity of the bombarded surface spots. By laterally varying the bombarding spot on the surface, the entire target can be scanned and chemically analyzed. However, the particle detection, which bases upon deflection in electric fields, is limited to those species that leave the surface in an ionized state. Due to the fact that the ionized fraction of the total flux of sputtered atoms often only amounts to a few percent or even less, the detection is often hampered by rather low signals. Moreover, it is well known, that the ionization probability of emitted particles does not only depend on the elementary species, but also on the local environment from which a particle leaves the surface. Therefore, the measured signals for different sputtered species do not necessarily represent the stoichiometric composition of the sample. In the literature, this phenomenon is known as the Matrix Effect in SIMS. In order to circumvent this principal shortcoming of SIMS, the present thesis develops an alternative computer simulation concept, which treats the electronic energy losses of all moving atoms as excitation sources feeding energy into the electronic sub-system of the solid. The particle kinetics determining the excitation sources are delivered by classical molecular dynamics. The excitation energy calculations are combined with a diffusive transport model to describe the spread of excitation energy from the initial point of generation. Calculation results yield a space- and time-resolved excitation

  11. Combinatorial and off-shell effects in new physics cascades

    Energy Technology Data Exchange (ETDEWEB)

    Wiesler, Daniel

    2012-12-15

    Up to now, the Standard Model of elementary particle physics is in very good agreement with most data. However, it has various shortcomings which motivate the presence of new physics at the TeV scale. The first major step following a potential discovery of new particles at the Large Hadron Collider (LHC) is the determination of their intrinsic properties, foremost masses and spins. Event topologies of new physics signals with a conserved parity motivated by precision data and the dark matter paradigm require for sophisticated measurement procedures, which have been developed in recent years. These techniques often rely on simplifying assumptions, albeit they need not necessarily be fulfilled. In this thesis we investigate the impact of combinatorial and off-shell effects on new physics cascades in three different contexts. A detailed understanding of these effects is essential for the topic of model parameter determination of new physics signatures at the LHC. First, we study the non-resonant contributions of a broad gluino on mass and spin measurements as a prime example for the importance of off-shell effects. A phenomenological scan over the gluino's width-to-mass ratio yields a severe smearing of invariant mass distributions and as a consequence thereof drastically shifted endpoint positions. Spin determinations, on the other hand, are barely affected and a model discrimination of the two prime candidates SUSY and UED is not at risk. In the second part, we assess the feasibility of the gluino dijet endpoint measurement in three fully inclusive scenarios at the LHC to investigate the impact of combinatorial and SUSY backgrounds on its precise determination. We develop a method to disentangle two major signal contributions and extract their associated edges with good accuracy. For this we use existent kinematic variables and propose new ones to overcome the former's deficiencies. The last part governs the issue of so-called 'fake combinatorics

  12. Cascade processing of wheat bran through a biorefinery approach

    International Nuclear Information System (INIS)

    Celiktas, Melih Soner; Kirsch, Christian; Smirnova, Irina

    2014-01-01

    Highlights: • About 98% of total sugars were successfully converted and recovered from wheat bran. • LHW and effective enzyme-assisted extraction method is used to obtain total sugar. • Sequential treatment of various materials can be a great value to the industry. • High pressure and LHW can be a valuable treatment for the lignocellulosic materials. • Protein separation can be done with LHW. - Abstract: Structural characteristics of wheat bran such as surface area, crystallinity, cellulose, hemicellulose, and lignin content significantly affect the yield of biorefinery products such as protein, fermentable sugar and lignin. The aim of the study was to use a sequence of high pressure extraction and hydrolysis processes in a cascade to create high potential value added products, namely, proteins, fermentable sugars and lignin. In the present study, four different sets of experiments were carried out step by step in a cascade sequence. The main experiments were the sequential extraction and hydrolysis which were optimized using design of experiments. Protein extraction from wheat bran was performed in a fixed bed reactor and was maximized to 1.976 g/L at the elicited optimum conditions which were 80 °C, pH 9.3 for a duration of 30 min. In the sequential experiment, process parameters such as temperature, flow rate and duration were optimized for liquid hot water (LHW) hydrolysis. The maximum reducing sugar concentration was 200 g/kg which corresponded to 34% per dry biomass obtained at a flow rate of 5 ml/min, temperature of 210 °C during a 45 min treatment. The following step was enzymatic hydrolysis to saccharify the cellulose under high pressure, where the independent variables were pressure, temperature and process time in order to ascertain the process conditions maximizing the reducing sugar content, where a positive correlation was observed between the solid–liquid loading ratio and reducing sugar yield. In the final step, the lignin content of

  13. Techniques for detecting the Cherenkov light from cascade showers in water

    Science.gov (United States)

    Khomyakov, V. A.; Bogdanov, A. G.; Kindin, V. V.; Kokoulin, R. P.; Petrukhin, A. A.; Khokhlov, S. S.; Shutenko, V. V.; Yashin, I. I.

    2018-01-01

    The NEVOD Cherenkov water detector (CWD) features a denser lattice of sensitive elements than the existing large-scale CWDs, whereby the spatial distribution of Cherenkov light from cascade showers is sampled with a superior resolution of 0.5 m, which is close to one radiation length for water (36 cm). The experimental techniques for investigating the Cherenkov light generated by particle cascades in water is proposed. The dependence of light intensity on the depth of shower development is for the first time measured at different distances from the shower axis. The results are compared with the Cherenkov light distributions predicted by various model descriptions for the scattering of cascade particles.

  14. Generalized weighted crosstalk for DWDM systems with cascaded wavelength-selective switches.

    Science.gov (United States)

    Filer, Mark; Tibuleac, Sorin

    2012-07-30

    A generalized method for estimating transmission penalties from spectrally-shaped crosstalk in cascaded multi-port WSS networks is derived, including effects of ASE, signal filtering, and crosstalk filtering. The weighted crosstalk value is computed by multiplying the shaped interfering signal by the power spectral density of the primary signal. This value is used to predict OSNR penalties in networks with cascaded WSSs of arbitrary port count. Theoretical treatment is supported by extensive numerical simulations and experiments for a variety of network configurations. Examples are presented for 43 Gb/s DPSK and 120 Gb/s DP-QPSK in cascaded ROADM networks with three distinct WSS types.

  15. R&D Experiments at BNL to Address the Associated Issues in the Cascading HGHG Scheme

    CERN Document Server

    Yu Li Hua

    2004-01-01

    We discuss several experiments that can be carried out at BNL's DUVFEL to address several issues associated with cascaded HGHG FELs. These include: Chirped Pulse Amplification (CPA); HGHG with seed shorter than electron bunch length; 8th harmonic HGHG (from 800nm to 100nm); Regenerative synchronization of seed pulse and electron bunch; Tuning of HGHG without changing seed, proposed by Timur Shaftan; Cascading using NISUS and VISA: from 400nm to 100nm to 50nm. These experiments may have important impact on the development of multi-stage cascaded HGHG FELs.

  16. Scale-separation scheme for simulating superfluid turbulence: Kelvin-Wave cascade

    International Nuclear Information System (INIS)

    Kozik, Evgeny; Svistunov, Boris

    2005-01-01

    A Kolmogorov-type cascade of Kelvin waves--the distortion waves on vortex lines--plays a key part in the relaxation of superfluid turbulence at low temperatures. We propose an efficient numeric scheme for simulating the Kelvin-wave cascade on a single vortex line. This idea is likely to be generalizable for a full-scale simulation of different regimes of superfluid turbulence. With the new scheme, we are able to unambiguously resolve the cascade spectrum exponent, and thus to settle the controversy between recent simulations of Vinen, Tsubota, and Mitani [Phys. Rev. Lett. 91, 135301 (2003)] and recently developed analytic theory [Phys. Rev. Lett. 92, 035301 (2004)

  17. Technical note: Cascade of submerged reservoirs as a rainfall-runoff model

    Science.gov (United States)

    Kurnatowski, Jacek

    2017-09-01

    The rainfall-runoff conceptual model as a cascade of submerged linear reservoirs with particular outflows depending on storages of adjoining reservoirs is developed. The model output contains different exponential functions with roots of Chebyshev polynomials of the first kind as exponents. The model is applied to instantaneous unit hydrograph (IUH) and recession curve problems and compared with the analogous results of the Nash cascade. A case study is performed on a basis of 46 recession periods. Obtained results show the usefulness of the model as an alternative concept to the Nash cascade.

  18. Distributed dual-parameter optical fiber sensor based on cascaded microfiber Fabry-Pérot interferometers

    Science.gov (United States)

    Xiang, Yang; Luo, Yiyang; Zhang, Wei; Liu, Deming; Sun, Qizhen

    2017-04-01

    We propose and demonstrate a distributed fiber sensor based on cascaded microfiber Fabry-Perot interferometers (MFPI) for simultaneous refractive index (SRI) and temperature measurement. By employing MFPI which is fabricated by taper-drawing the center of a uniform fiber Bragg grating (FBG) on standard fiber into a section of microfiber, dual parameters including SRI and temperature can be detected through demodulating the reflection spectrum of the MFPI. Further, wavelength-division-multiplexing (WDM) is applied to realize distributed dual-parameter fiber sensor by using cascaded MFPIs with different Bragg wavelengths. A prototype sensor system with 5 cascaded MFPIs is constructed to experimentally demonstrate the sensing performance.

  19. On a possibility of restoration of an arbitrary shape hadron cascade in the atmosphere

    International Nuclear Information System (INIS)

    Kvashnin, A.N.; Rubtsov, V.I.; Smirnov, A.Yu.; Yakovlev, V.I.

    1985-01-01

    A problem of restoring hadron cascade of an arbitrary form in the atmosphere has been considered. The restoration method of hadron cascade is based on using time and amplitude detectors of the Cherenkov radiation. The calculation of the Cherenkov radiation intensity at distances above 200 m from the shower axis was conducted in the approximation of a luminous point model. It is shown that using 5-6 time and amplitude detectors at the above-mentioned distance parameters of a cascade curve can be estimated solving a set of nonlinear equations

  20. Miniaturized high-temperature superconducting multiplexer with cascaded quadruplet structure

    Science.gov (United States)

    Xu, Zhang; Jingping, Liu; Shaolin, Yan; Lan, Fang; Bo, Zhang; Xinjie, Zhao

    2015-06-01

    In this paper, compact high temperature superconducting (HTS) multiplexers are presented for satellite communication applications. The first multiplexer consists of an input coupling node and three high-order bandpass filters, which is named triplexer. The node is realized by a loop microstrip line instead of conventional T-junction to eliminate the redundant susceptance due to combination of three filters. There are two eight-pole band-pass filters and one ten-pole band-pass filter with cascaded quadruplet structure for realizing high isolation. Moreover, the triplexer is extended to a multiplexer with six channels so as to verify the expansibility of the suggested approach. The triplexer is fabricated using double-sided YBa2Cu3O7 thin films on a 38 × 25 mm2 LaAlO3 substrate. The experimental results, when compared with those ones from the T-junction multiplexer, show that our multiplexer has lower insertion loss, smaller sizes and higher isolation between any two channels. Also, good agreement has been achieved between simulations and measurements, which illustrate the effectiveness of our methods for the design of high performance HTS multiplexers.

  1. Terahertz GaAs/AlAs quantum-cascade lasers

    Energy Technology Data Exchange (ETDEWEB)

    Schrottke, L., E-mail: lutz@pdi-berlin.de; Lü, X.; Rozas, G.; Biermann, K.; Grahn, H. T. [Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5–7, 10117 Berlin (Germany)

    2016-03-07

    We have realized GaAs/AlAs quantum-cascade lasers operating at 4.75 THz exhibiting more than three times higher wall plug efficiencies than GaAs/Al{sub 0.25}Ga{sub 0.75}As lasers with an almost identical design. At the same time, the threshold current density at 10 K is reduced from about 350 A/cm{sup 2} for the GaAs/Al{sub 0.25}Ga{sub 0.75}As laser to about 120 A/cm{sup 2} for the GaAs/AlAs laser. Substituting AlAs for Al{sub 0.25}Ga{sub 0.75}As barriers leads to a larger energy separation between the subbands reducing the probability for leakage currents through parasitic states and for reabsorption of the laser light. The higher barriers allow for a shift of the quasi-continuum of states to much higher energies. The use of a binary barrier material may also reduce detrimental effects due to the expected composition fluctuations in ternary alloys.

  2. Complex interdependent supply chain networks: Cascading failure and robustness

    Science.gov (United States)

    Tang, Liang; Jing, Ke; He, Jie; Stanley, H. Eugene

    2016-02-01

    A supply chain network is a typical interdependent network composed of an undirected cyber-layer network and a directed physical-layer network. To analyze the robustness of this complex interdependent supply chain network when it suffers from disruption events that can cause nodes to fail, we use a cascading failure process that focuses on load propagation. We consider load propagation via connectivity links as node failure spreads through one layer of an interdependent network, and we develop a priority redistribution strategy for failed loads subject to flow constraint. Using a giant component function and a one-to-one directed interdependence relation between nodes in a cyber-layer network and physical-layer network, we construct time-varied functional equations to quantify the dynamic process of failed loads propagation in an interdependent network. Finally, we conduct a numerical simulation for two cases, i.e., single node removal and multiple node removal at the initial disruption. The simulation results show that when we increase the number of removed nodes in an interdependent supply chain network its robustness undergoes a first-order discontinuous phase transition, and that even removing a small number of nodes will cause it to crash.

  3. A cascade modelling approach to flood extent estimation

    Science.gov (United States)

    Pedrozo-Acuña, Adrian; Rodríguez-Rincón, Juan Pablo; Breña-Naranjo, Agustin

    2014-05-01

    Recent efforts dedicated to the generation of new flood risk management strategies, have pointed out that a possible way forward for an improvement in this field relies on the reduction and quantification of uncertainties associated to the prediction system. With the purpose of reducing these uncertainties, this investigation follows a cascade modelling approach (meteorological - hydrological - 2D hydrodynamic) in combination with high-quality data (LiDAR, satellite imagery, precipitation), to study an extreme event registered last year in Mexico. The presented approach is useful for both, the characterisation of epistemic uncertainties and the generation of flood management strategies through probabilistic flood maps. Uncertainty is considered in both meteorological and hydrological models, and is propagated to a given flood extent as determined with a hydrodynamic model. Despite the methodology does not consider all the uncertainties that may be involved in the determination of a flooded area, it enables better understanding of the interaction between errors in the set-up of models and their propagation to a given result.

  4. Is Neurotoxicity of Metallic Nanoparticles the Cascades of Oxidative Stress?

    Science.gov (United States)

    Song, Bin; Zhang, YanLi; Liu, Jia; Feng, XiaoLi; Zhou, Ting; Shao, LongQuan

    2016-06-01

    With the rapid development of nanotechnology, metallic (metal or metal oxide) nanoparticles (NPs) are widely used in many fields such as cosmetics, the food and building industries, and bio-medical instruments. Widespread applications of metallic NP-based products increase the health risk associated with human exposures. Studies revealed that the brain, a critical organ that consumes substantial amounts of oxygen, is a primary target of metallic NPs once they are absorbed into the body. Oxidative stress (OS), apoptosis, and the inflammatory response are believed to be the main mechanisms underlying the neurotoxicity of metallic NPs. Other studies have disclosed that antioxidant pretreatment or co-treatment can reverse the neurotoxicity of metallic NPs by decreasing the level of reactive oxygen species, up-regulating the activities of antioxidant enzymes, decreasing the proportion of apoptotic cells, and suppressing the inflammatory response. These findings suggest that the neurotoxicity of metallic NPs might involve a cascade of events following NP-induced OS. However, additional research is needed to determine whether NP-induced OS plays a central role in the neurotoxicity of metallic NPs, to develop a comprehensive understanding of the correlations among neurotoxic mechanisms and to improve the bio-safety of metallic NP-based products.

  5. Interaction of LRRK2 with kinase and GTPase signaling cascades

    Directory of Open Access Journals (Sweden)

    Joon Y Boon

    2014-07-01

    Full Text Available LRRK2 is a protein that interacts with a plethora of signaling molecules, but the complexity of LRRK2 function presents a challenge for understanding the role of LRRK2 in the pathophysiology of Parkinson’s disease. Studies of LRRK2 using over-expression in transgenic mice have been disappointing, however studies using invertebrate systems have yielded a much clearer picture, with clear effects of LRRK2 expression, knockdown or deletion in C. elegans and Drosophila on modulation of survival of dopaminergic neurons. Recent studies have begun to focus attention on particular signaling cascades that are a target of LRRK2 function. LRRK2 interacts with members of the MAPK pathway and might regulate the pathway action by acting as a scaffold that directs the location of MAPK pathway activity, without strongly affecting the amount of MAPK pathway activity. Binding to GTPases, GAPs and GEFs are another strong theme in LRRK2 biology, with LRRK2 binding to Rac1, cdc42, rab5, rab7L1, endoA, RGS2, ArfGAP1 and ArhGEF7. All of these molecules appear to feed into a function output for LRRK2 that modulates cytoskeletal outgrowth and vesicular dynamics, including autophagy. These functions likely impact modulation of α-synuclein aggregation and associated toxicity eliciting the disease processes that we term Parkinson’s disease.

  6. Contrasting effects of aquatic subsidies on a terrestrial trophic cascade.

    Science.gov (United States)

    Graf, Nadin; Bucher, Roman; Schäfer, Ralf B; Entling, Martin H

    2017-05-01

    Subsidies from adjacent ecosystems can alter recipient food webs and ecosystem functions, such as herbivory. Emerging aquatic insects from streams can be an important prey in the riparian zone. Such aquatic subsidies can enhance predator abundances or cause predators to switch prey, depending on the herbivores. This can lead to an increase or decrease of in situ herbivores and herbivory. We examined the effects of aquatic subsidies on a simplified terrestrial food web consisting of two types of herbivores, plants and predators (spiders). In our six-week experiment, we focused on the prey choice of the spiders by excluding predator immigration and reproduction. In accordance with predator switching, survival of leafhoppers increased in the presence of aquatic subsidies. By contrast, the presence of aquatic subsidies indirectly reduced weevils and herbivory. Our study shows that effects of aquatic subsidies on terrestrial predators can propagate through the food web in contrasting ways. Thereby, the outcome of the trophic cascade is determined by the prey choice of predators. © 2017 The Author(s).

  7. What is turbulence and which way does it cascade?

    Science.gov (United States)

    Gibson, Carl

    2017-11-01

    Turbulence is defined as an eddy-like state of fluid motion, where the inertial vortex forces v x curl v of the eddies are larger than any other forces that tend to damp the eddies out. In the beginning at Planck conditions, it is assumed that the relevant dimensional parameters were the speed of light c, the Planck constant h, the Newton constant G, and the Boltzmann constant k. The first turbulence appeared at 10-43 s, 10-35 m, 1032 K when the Kolmogorov scale first matched the horizon scale ct. Inertial vortex forces of adjacent fluid particles with the same spin cause them to merge, so the turbulence cascade is always from small scales to large, as observed, contrary to the standard Taylor-Lumley model which must be abandoned. Adjacent fluid particles with opposite spin repel each other and are repelled by walls, which explains boundary layer separation and turbulent diffusion. The second turbulence appeared at 1012 seconds at density 10-17 kg m-3 with the fragmentation of protogalaxies along fossil big bang turbulence vortex lines. Life began at 1013 seconds in Jeans mass clumps of a trillion planets.

  8. A reverse energy cascade for crustal magma transport

    Science.gov (United States)

    Karlstrom, Leif; Paterson, Scott R.; Jellinek, A. Mark

    2017-08-01

    Direct constraints on the ascent, storage and eruption of mantle melts come primarily from exhumed, long-frozen intrusions. These structures, relics of a dynamic magma transport network, encode how Earth's crust grows and differentiates over time. Furthermore, they connect mantle melting to an evolving distribution of surface volcanism. Disentangling magma transport processes from the plutonic record is consequently a seminal but unsolved problem. Here we use field data analyses, scaling theory and numerical simulations to show that the size distribution of intrusions preserved as plutonic complexes in the North American Cordillera suggests a transition in the mechanical response of crustal rocks to protracted episodes of magmatism. Intrusion sizes larger than about 100 m follow a power-law scaling expected if energy delivered from the mantle to open very thin dykes and sills is transferred to intrusions of increasing size. Merging, assimilation and mixing of small intrusions into larger ones occurs until irreversible deformation and solidification dissipate available energy. Mantle magma supply over tens to hundreds of thousands of years will trigger this regime, a type of reverse energy cascade, depending on the influx rate and efficiency of crustal heating by intrusions. Identifying regimes of magma transport provides a framework for inferring subsurface magmatic processes from surface patterns of volcanism, information preservation in the plutonic record, and related effects including climate.

  9. High power-efficiency terahertz quantum cascade laser

    Science.gov (United States)

    Li, Yuan-Yuan; Liu, Jun-Qi; Liu, Feng-Qi; Zhang, Jin-Chuan; Zhai, Shen-Qiang; Zhuo, Ning; Wang, Li-Jun; Liu, Shu-Man; Wang, Zhan-Guo

    2016-08-01

    We demonstrate continuous-wave (CW) high power-efficiency terahertz quantum cascade laser based on semi-insulating surface-plasmon waveguide with epitaxial-side down (Epi-down) mounting process. The performance of the device is analyzed in detail. The laser emits at a frequency of ˜ 3.27 THz and has a maximum CW operating temperature of ˜ 70 K. The peak output powers are 177 mW in pulsed mode and 149 mW in CW mode at 10 K for 130-μm-wide Epi-down mounted lasers. The record wall-plug efficiencies in direct measurement are 2.26% and 2.05% in pulsed and CW mode, respectively. Project supported by the National Basic Research Program of China (Grant Nos. 2014CB339803 and 2013CB632801), the Special-funded Program on National Key Scientific Instruments and Equipment Development, China (Grant No. 2011YQ13001802-04), and the National Natural Science Foundation of China (Grant No. 61376051).

  10. Estimation of Minimum DNBR Using Cascaded Fuzzy Neural Networks

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Yeong; Yoo, Kwae Hwan; Na, Man Gyun [Chosun University, Gwangju (Korea, Republic of)

    2015-05-15

    This phenomenon of boiling crisis is called a departure from nucleate boiling (DNB). The DNB phenomena can influence the fuel cladding and fuel pellets. The DNB ratio (DNBR) is defined as the ratio of the expected DNB heat flux to the actual fuel rod heat flux. Since it is very important to monitor and predict the minimum DNBR in a reactor core to prevent the boiling crisis and clad melting, a number of researches have been conducted to predict DNBR values. The aim of this study is to estimate the minimum DNBR in a reactor core using the measured signals of the reactor coolant system (RCS) by applying cascaded fuzzy neural networks (CFNN) according to operating conditions. Reactor core monitoring and protection systems require minimum DNBR prediction. The CFNN can be used to optimize the minimum DNBR value through the process of adding fuzzy neural networks (FNN) repeatedly. The proposed algorithm is trained by using the data set prepared for training (development data) and verified by using another data set different (independent) from the development data. The developed CFNN models were applied to the first fuel cycle of OPR1000. The RMS errors are 0.23% and 0.12% for the positive and negative ASI, respectively.

  11. Cascaded H-bridge multilevel inverter for renewable energy generation

    Science.gov (United States)

    Pandey, Ravikant; Nath Tripathi, Ravi; Hanamoto, Tsuyoshi

    2016-04-01

    In this paper cascaded H-bridge multilevel inverter (CHBMLI) has been investigated for the application of renewable energy generation. Energy sources like solar, wind, hydro, biomass or combination of these can be manipulated to obtain alternative sources for renewable energy generation. These renewable energy sources have different electrical characteristics like DC or AC level so it is challenging to use generated power by connecting to grid or load directly. The renewable energy source require specific power electronics converter as an interface for conditioning generated power .The multilevel inverter can be utilized for renewable energy sources in two different modes, the power generation mode (stand-alone mode), and compensator mode (statcom). The performance of the multilevel inverter has been compared with two level inverter. In power generation mode CHBMLI supplies the active and reactive power required by the different loads. For operation in compensator mode the indirect current control based on synchronous reference frame theory (SRFT) ensures the grid operating in unity power factor and compensate harmonics and reactive power.

  12. Cascade damage in nickel: Production, saturation and recovery

    International Nuclear Information System (INIS)

    Birtcher, R.C.; Blewitt, T.H.

    1988-01-01

    Changes in the electrical resistivity and length were simultaneously measured during the bombardment of nickel at 70 K with 235 U fission fragments and during a subsequent isothermal annealing program. The resistivity changes and length changes were linearly related during the damage production for damage concentrations less 80% of the defect saturation limit. The initial ratio of the length change to the resistivity change was 8.4x10 4 /Ω m. At high damage concentrations, the length change increased at a slightly higher rate than the resistivity change. During isothermal annealing of the near-saturation defect concentration, the resistivity and the length changes had identical recoveries through stage I and most of stage II. During stage III annealing, the ratio of the length change to the resistivity change showed a small increase. At temperatures above 475 K, this ratio showed a marked increase as the resistivity change exhibited recovery without a corresponding recovery of the length change. These differences, which are attributed to the direct formation and growth of three-dimensional vacancy agglomerates, and results of tranmission electron microscopy suggest that the sign of the third derivative of the resistivity with respect to fast-neutron fluence (the sense of curvature in the damage rate) is positive for materials in which cascades collapse to loops, and negative for materials in which three-dimensional vacancy agglomerates are stable. (orig.)

  13. Void nucleation at elevated temperatures under cascade-damage irradiation

    International Nuclear Information System (INIS)

    Semenov, A.A.; Woo, C.H.

    2002-01-01

    The effects on void nucleation of fluctuations respectively due to the randomness of point-defect migratory jumps, the random generation of free point defects in discrete packages, and the fluctuating rate of vacancy emission from voids are considered. It was found that effects of the cascade-induced fluctuations are significant only at sufficiently high total sink strength. At lower sink strengths and elevated temperatures, the fluctuation in the rate of vacancy emission is the dominant factor. Application of the present theory to the void nucleation in annealed pure copper neutron-irradiated at elevated temperatures with doses of 10 -4 -10 -2 NRT dpa showed reasonable agreement between theory and experiment. This application also predicts correctly the temporal development of large-scale spatial heterogeneous microstructure during the void nucleation stage. Comparison between calculated and experimental void nucleation rates in neutron-irradiated molybdenum at temperatures where vacancy emission from voids is negligible showed reasonable agreement as well. It was clearly demonstrated that the athermal shrinkage of relatively large voids experimentally observable in molybdenum at such temperatures may be easily explained in the framework of the present theory

  14. Experimental and theoretical study of cascade solar stills in Iran

    International Nuclear Information System (INIS)

    Tabrizi, F.F.; Sharak, A.Z.

    2009-01-01

    Due to low annual rainfall, most of Iran is dominated by arid and semi-arid areas. The solar radiation intensity is extremely high in most of the country. The need to produce fresh water from brackish water is considerably high, especially in dry regions. Desalination of brackish water may become a competitive potential water resource to meet potable water demand, and as the price of oil goes higher, using solar energy for water desalinisation becomes more economical. This paper presented a study that involved mathematical modeling of the first solar still in Iran. The cumulative fresh water production and water temperature were calculated as a function of time. The obtained results were verified by one month daily-based experimental data. The paper also provided background information on the Koshk village, situated in the south part of Iran near Badar Abbas city. Various investigations regarding meteorological conditions, economical considerations, and technical and operational appropriateness demonstrated that the cascade solar still is suitable for desalination of brackish water. 100 solar stills were installed at the site to provide potable water for a nearby village. It was concluded that the model could be used to simulate and optimize the effective design parameters in future studies. 6 refs., 7 figs

  15. Cascaded deep decision networks for classification of endoscopic images

    Science.gov (United States)

    Murthy, Venkatesh N.; Singh, Vivek; Sun, Shanhui; Bhattacharya, Subhabrata; Chen, Terrence; Comaniciu, Dorin

    2017-02-01

    Both traditional and wireless capsule endoscopes can generate tens of thousands of images for each patient. It is desirable to have the majority of irrelevant images filtered out by automatic algorithms during an offline review process or to have automatic indication for highly suspicious areas during an online guidance. This also applies to the newly invented endomicroscopy, where online indication of tumor classification plays a significant role. Image classification is a standard pattern recognition problem and is well studied in the literature. However, performance on the challenging endoscopic images still has room for improvement. In this paper, we present a novel Cascaded Deep Decision Network (CDDN) to improve image classification performance over standard Deep neural network based methods. During the learning phase, CDDN automatically builds a network which discards samples that are classified with high confidence scores by a previously trained network and concentrates only on the challenging samples which would be handled by the subsequent expert shallow networks. We validate CDDN using two different types of endoscopic imaging, which includes a polyp classification dataset and a tumor classification dataset. From both datasets we show that CDDN can outperform other methods by about 10%. In addition, CDDN can also be applied to other image classification problems.

  16. The cascading pebble divertor for the spherical tokamak power plant

    International Nuclear Information System (INIS)

    Voss, G.M.; Bond, A.; Davis, S.; Harte, M.; Watson, R.

    2006-01-01

    The design of a power plant based on the spherical tokamak (ST) is being developed in order to explore its potential advantages. The plasma is operated in a double null configuration, forming both an upper and lower divertor. In order to accommodate the high erosion rates and heat fluxes developed in the divertors, a system based on a cascading flow of silicon carbide pebbles is being developed. The pebbles flow into the upper divertor where they fall as a toroidal curtain, which intercepts the divertor particle flux. The pebbles then flow under gravity through ducts to the lower divertor where they form a similar curtain. The bulk temperature of the pebbles rises to about 1150 deg. C although the outer surface is transiently heated to about 1800 deg. C. The pebbles pass out of the vacuum chamber into holding tanks and then into a fluidised bed heat exchanger. Here the pebbles are cooled down to about 340 deg. C and dust and damaged pebbles are removed. The pebbles are transferred to an upper tank by a pneumatic conveyor where the remaining gas is removed and the pebbles flow into the upper divertor again

  17. Defence and security applications of quantum cascade lasers

    Science.gov (United States)

    Grasso, Robert J.

    2016-09-01

    Quantum Cascade Lasers (QCL) have seen tremendous recent application in the realm of Defence and Security. And, in many instances replacing traditional solid state lasers as the source of choice for Countermeasures, Remote Sensing, In-situ Sensing, Through-Barrier Sensing, and many others. Following their development and demonstration in the early 1990's, QCL's reached some maturity and specific defence and security application prior to 2005; with much initial development fostered by DARPA initiatives in the US, dstl, MoD, and EOARD funding initiatives in the UK, and University level R&D such as those by Prof Manijeh Razeghi at Northwestern University [1], and Prof Ted Masselink at Humboldt University [2]. As QCL's provide direct mid-IR laser output for electrical input, they demonstrate high quantum efficiency compared with diode pumped solid state lasers with optical parametric oscillators (OPOs) to generate mid-Infrared output. One particular advantage of QCL's is their very broad operational bandwidth, extending from the terahertz to the near-infrared spectral regions. Defence and Security areas benefiting from QCL's include: Countermeasures, Remote Sensing, Through-the-Wall Sensing, and Explosive Detection. All information used to construct this paper obtained from open sources.

  18. Cascades and Dissipative Anomalies in Relativistic Fluid Turbulence

    Science.gov (United States)

    Eyink, Gregory L.; Drivas, Theodore D.

    2018-02-01

    We develop a first-principles theory of relativistic fluid turbulence at high Reynolds and Péclet numbers. We follow an exact approach pioneered by Onsager, which we explain as a nonperturbative application of the principle of renormalization-group invariance. We obtain results very similar to those for nonrelativistic turbulence, with hydrodynamic fields in the inertial range described as distributional or "coarse-grained" solutions of the relativistic Euler equations. These solutions do not, however, satisfy the naive conservation laws of smooth Euler solutions but are afflicted with dissipative anomalies in the balance equations of internal energy and entropy. The anomalies are shown to be possible by exactly two mechanisms, local cascade and pressure-work defect. We derive "4 /5 th-law" type expressions for the anomalies, which allow us to characterize the singularities (structure-function scaling exponents) required for their not vanishing. We also investigate the Lorentz covariance of the inertial-range fluxes, which we find to be broken by our coarse-graining regularization but which is restored in the limit where the regularization is removed, similar to relativistic lattice quantum field theory. In the formal limit as speed of light goes to infinity, we recover the results of previous nonrelativistic theory. In particular, anomalous heat input to relativistic internal energy coincides in that limit with anomalous dissipation of nonrelativistic kinetic energy.

  19. Cascades and Dissipative Anomalies in Relativistic Fluid Turbulence

    Directory of Open Access Journals (Sweden)

    Gregory L. Eyink

    2018-02-01

    Full Text Available We develop a first-principles theory of relativistic fluid turbulence at high Reynolds and Péclet numbers. We follow an exact approach pioneered by Onsager, which we explain as a nonperturbative application of the principle of renormalization-group invariance. We obtain results very similar to those for nonrelativistic turbulence, with hydrodynamic fields in the inertial range described as distributional or “coarse-grained” solutions of the relativistic Euler equations. These solutions do not, however, satisfy the naive conservation laws of smooth Euler solutions but are afflicted with dissipative anomalies in the balance equations of internal energy and entropy. The anomalies are shown to be possible by exactly two mechanisms, local cascade and pressure-work defect. We derive “4/5th-law” type expressions for the anomalies, which allow us to characterize the singularities (structure-function scaling exponents required for their not vanishing. We also investigate the Lorentz covariance of the inertial-range fluxes, which we find to be broken by our coarse-graining regularization but which is restored in the limit where the regularization is removed, similar to relativistic lattice quantum field theory. In the formal limit as speed of light goes to infinity, we recover the results of previous nonrelativistic theory. In particular, anomalous heat input to relativistic internal energy coincides in that limit with anomalous dissipation of nonrelativistic kinetic energy.

  20. Apolipoprotein E: Essential Catalyst of the Alzheimer Amyloid Cascade

    Directory of Open Access Journals (Sweden)

    Huntington Potter

    2012-01-01

    Full Text Available The amyloid cascade hypothesis remains a robust model of AD neurodegeneration. However, amyloid deposits contain proteins besides Aβ, such as apolipoprotein E (apoE. Inheritance of the apoE4 allele is the strongest genetic risk factor for late-onset AD. However, there is no consensus on how different apoE isotypes contribute to AD pathogenesis. It has been hypothesized that apoE and apoE4 in particular is an amyloid catalyst or “pathological chaperone”. Alternatively it has been posited that apoE regulates Aβ clearance, with apoE4 been worse at this function compared to apoE3. These views seem fundamentally opposed. The former would indicate that removing apoE will reduce AD pathology, while the latter suggests increasing brain ApoE levels may be beneficial. Here we consider the scientific basis of these different models of apoE function and suggest that these seemingly opposing views can be reconciled. The optimal therapeutic target may be to inhibit the interaction of apoE with Aβ rather than altering apoE levels. Such an approach will not have detrimental effects on the many beneficial roles apoE plays in neurobiology. Furthermore, other Aβ binding proteins, including ACT and apo J can inhibit or promote Aβ oligomerization/polymerization depending on conditions and might be manipulated to effect AD treatment.