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Sample records for bundle sheath cells

  1. FUNCTION OF MALATDEHYDROGENASE COMPLEX OF MAIZE MESOPHYLL AND BUNDLE SHEATH CELLS UNDER SALT STRESS CONDITION

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    Еprintsev А.Т.

    2006-12-01

    Full Text Available Salt-induced changes in malatdehydrogenase system activity make the essential contribution to cell adaptation to stress condition. The enzyme systems of C4-plants are most interesting due to their ability for adaptation to environment conditions. The role of separate components of malatdehydrogenase complex of mesophyll and bundle sheath cells of corn in formation of adaptive reaction in stressful conditions is investigated in presented work.The activation of all enzymes of malatdehydrogenase system and the subsequent decrease in their activity was observed in mesophyll durring the first stage of adaptation to salt influence. In bundle sheath cells such parameters are differed from control less essentially. Fast accumulation of piruvate in cells and malate in both investigated tissues was induced. The further salinity led to falling of concentration this intermediate. The concentration of piruvate was below control level, and it was raised by the end of an exposition.The results show that sodium chloride causes induction of Krebs-cycle in mesophyll and bundle sheath cells of corn and intensification of Hatch-Slack cycle. The described differences in function malatdehydrogenase systems of mesophyll and bundle sheath cells of leaves of corn under salinity mainly consist of the activity of enzymes of a studied complex in bundle sheath cells is subject to the minimal changes in comparison with mesophyll. Role of this enzymesystem in mechanisms of adaptive reaction of various tissues of corn to salt stress is discussed.

  2. Post-Transcriptional Regulation Prevents Accumulation of Glutathione Reductase Protein and Activity in the Bundle Sheath Cells of Maize1

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    Pastori, Gabriela M.; Mullineaux, Philip M.; Foyer, Christine H.

    2000-01-01

    Glutathione reductase (GR; EC 1.6.4.2) activity was assayed in bundle sheath and mesophyll cells of maize (Zea mays L. var H99) from plants grown at 20°C, 18°C, and 15°C. The purity of each fraction was determined by measuring the associated activity of the compartment-specific marker enzymes, Rubisco and phosphoenolpyruvate carboxylase, respectively. GR activity and the abundance of GR protein and mRNA increased in plants grown at 15°C and 18°C compared with those grown at 20°C. In all cases GR activity was found only in mesophyll fractions of the leaves, with no GR activity being detectable in bundle sheath extracts. Immunogold labeling with GR-specific antibodies showed that the GR protein was exclusively localized in the mesophyll cells of leaves at all growth temperatures, whereas GR transcripts (as determined by in situ hybridization techniques) were observed in both cell types. These results indicate that post-transcriptional regulation prevents GR accumulation in the bundle sheath cells of maize leaves. The resulting limitation on the capacity for regeneration of reduced glutathione in this compartment may contribute to the extreme chilling sensitivity of maize leaves. PMID:10712529

  3. Consequences of C4 differentiation for chloroplast membrane proteomes in maize mesophyll and bundle sheath cells.

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    Majeran, Wojciech; Zybailov, Boris; Ytterberg, A Jimmy; Dunsmore, Jason; Sun, Qi; van Wijk, Klaas J

    2008-09-01

    Chloroplasts of maize leaves differentiate into specific bundle sheath (BS) and mesophyll (M) types to accommodate C(4) photosynthesis. Chloroplasts contain thylakoid and envelope membranes that contain the photosynthetic machineries and transporters but also proteins involved in e.g. protein homeostasis. These chloroplast membranes must be specialized within each cell type to accommodate C(4) photosynthesis and regulate metabolic fluxes and activities. This quantitative study determined the differentiated state of BS and M chloroplast thylakoid and envelope membrane proteomes and their oligomeric states using innovative gel-based and mass spectrometry-based protein quantifications. This included native gels, iTRAQ, and label-free quantification using an LTQ-Orbitrap. Subunits of Photosystems I and II, the cytochrome b(6)f, and ATP synthase complexes showed average BS/M accumulation ratios of 1.6, 0.45, 1.0, and 1.33, respectively, whereas ratios for the light-harvesting complex I and II families were 1.72 and 0.68, respectively. A 1000-kDa BS-specific NAD(P)H dehydrogenase complex with associated proteins of unknown function containing more than 15 proteins was observed; we speculate that this novel complex possibly functions in inorganic carbon concentration when carboxylation rates by ribulose-bisphosphate carboxylase/oxygenase are lower than decarboxylation rates by malic enzyme. Differential accumulation of thylakoid proteases (Egy and DegP), state transition kinases (STN7,8), and Photosystem I and II assembly factors was observed, suggesting that cell-specific photosynthetic electron transport depends on post-translational regulatory mechanisms. BS/M ratios for inner envelope transporters phosphoenolpyruvate/P(i) translocator, Dit1, Dit2, and Mex1 were determined and reflect metabolic fluxes in carbon metabolism. A wide variety of hundreds of other proteins showed differential BS/M accumulation. Mass spectral information and functional annotations are

  4. Cyst(e)ine Is the Transport Metabolite of Assimilated Sulfur from Bundle-Sheath to Mesophyll Cells in Maize Leaves1

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    Burgener, Marta; Suter, Marianne; Jones, Stephanie; Brunold, Christian

    1998-01-01

    The intercellular distribution of the enzymes and metabolites of assimilatory sulfate reduction and glutathione synthesis was analyzed in maize (Zea mays L. cv LG 9) leaves. Mesophyll cells and strands of bundle-sheath cells from second leaves of 11-d-old maize seedlings were obtained by two different mechanical-isolation methods. Cross-contamination of cell preparations was determined using ribulose bisphosphate carboxylase (EC 4.1.1.39) and nitrate reductase (EC 1.6.6.1) as marker enzymes for bundle-sheath and mesophyll cells, respectively. ATP sulfurylase (EC 2.7.7.4) and adenosine 5′-phosphosulfate sulfotransferase activities were detected almost exclusively in the bundle-sheath cells, whereas GSH synthetase (EC 6.3.2.3) and cyst(e)ine, γ-glutamylcysteine, and glutathione were located predominantly in the mesophyll cells. Feeding experiments using [35S]sulfate with intact leaves indicated that cyst(e)ine was the transport metabolite of reduced sulfur from bundle-sheath to mesophyll cells. This result was corroborated by tracer experiments, which showed that isolated bundle-sheath strands fed with [35S]sulfate secreted radioactive cyst(e)ine as the sole thiol into the resuspending medium. The results presented in this paper show that assimilatory sulfate reduction is restricted to the bundle-sheath cells, whereas the formation of glutathione takes place predominantly in the mesophyll cells, with cyst(e)ine functioning as a transport metabolite between the two cell types. PMID:9536048

  5. Evidence for a Role for NAD(P)H Dehydrogenase in Concentration of CO2 in the Bundle Sheath Cell of Zea mays.

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    Peterson, Richard B; Schultes, Neil P; McHale, Neil A; Zelitch, Israel

    2016-05-01

    Prior studies with Nicotiana and Arabidopsis described failed assembly of the chloroplastic NDH [NAD(P)H dehydrogenase] supercomplex by serial mutation of several subunit genes. We examined the properties of Zea mays leaves containing Mu and Ds insertions into nuclear gene exons encoding the critical o- and n-subunits of NDH, respectively. In vivo reduction of plastoquinone in the dark was sharply diminished in maize homozygous mutant compared to normal leaves but not to the extreme degree observed for the corresponding lesions in Arabidopsis. The net carbon assimilation rate (A) at high irradiance and saturating CO2 levels was reduced by one-half due to NDH mutation in maize although no genotypic effect was evident at very low CO2 levels. Simultaneous assessment of chlorophyll fluorescence and A in maize at low (2% by volume) and high (21%) O2 levels indicated the presence of a small, yet detectable, O2-dependent component of total linear photosynthetic electron transport in 21% O2 This O2-dependent component decreased with increasing CO2 level indicative of photorespiration. Photorespiration was generally elevated in maize mutant compared to normal leaves. Quantification of the proportion of total electron transport supporting photorespiration enabled estimation of the bundle sheath cell CO2 concentration (Cb) using a simple kinetic model of ribulose bisphosphate carboxylase/oxygenase function. The A versus Cb relationships overlapped for normal and mutant lines consistent with occurrence of strictly CO2-limited photosynthesis in the mutant bundle sheath cell. The results are discussed in terms of a previously reported CO2 concentration model [Laisk A, Edwards GE (2000) Photosynth Res 66: 199-224]. © 2016 American Society of Plant Biologists. All Rights Reserved.

  6. Barrier cell sheath formation

    International Nuclear Information System (INIS)

    Kesner, J.

    1980-04-01

    The solution for electrostatic potential within a simply modeled tandem mirror thermal barrier is seen to exhibit a sheath at each edge of the cell. The formation of the sheath requires ion collisionality and the analysis assmes that the collisional trapping rate into the barrier is considerably slower than the barrier pump rate

  7. Intracellular position of mitochondria and chloroplasts in bundle sheath and mesophyll cells of C3 grasses in relation to photorespiratory CO2 loss

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    Yuto Hatakeyama

    2016-10-01

    Full Text Available In C3 plants, photosynthetic efficiency is reduced by photorespiration. A part of CO2 fixed during photosynthesis in chloroplasts is lost from mitochondria during photorespiration by decarboxylation of glycine by glycine decarboxylase (GDC. Thus, the intracellular position of mitochondria in photosynthetic cells is critical to the rate of photorespiratory CO2 loss. We investigated the intracellular position of mitochondria in parenchyma sheath (PS and mesophyll cells of 10 C3 grasses from 3 subfamilies (Ehrhartoideae, Panicoideae, and Pooideae by immunostaining for GDC and light and electron microscopic observation. Immunostaining suggested that many mitochondria were located in the inner half of PS cells and on the vacuole side of chloroplasts in mesophyll cells. Organelle quantification showed that 62–75% of PS mitochondria were located in the inner half of cells, and 62–78% of PS chloroplasts were in the outer half. In mesophyll cells, 61–92% of mitochondria were positioned on the vacuole side of chloroplasts and stromules. In PS cells, such location would reduce the loss of photorespiratory CO2 by lengthening the path of CO2 diffusion and allow more efficient fixation of CO2 from intercellular spaces. In mesophyll cells, it would facilitate scavenging by chloroplasts of photorespiratory CO2 released from mitochondria. Our data suggest that the PS cells of C3 grasses have already acquired an initial structure leading to proto-Kranz and further C3–C4 intermediate anatomy. We also found that in the Pooideae, organelle positioning in PS cells on the phloem side resembles that in mesophyll cells.

  8. Bundle-sheath leakiness in C4 photosynthesis: a careful balancing act between CO2 concentration and assimilation.

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    Kromdijk, Johannes; Ubierna, Nerea; Cousins, Asaph B; Griffiths, Howard

    2014-07-01

    Crop species with the C4 photosynthetic pathway are generally characterized by high productivity, especially in environmental conditions favouring photorespiration. In comparison with the ancestral C3 pathway, the biochemical and anatomical modifications of the C4 pathway allow spatial separation of primary carbon acquisition in mesophyll cells and subsequent assimilation in bundle-sheath cells. The CO2-concentrating C4 cycle has to operate in close coordination with CO2 reduction via the Calvin-Benson-Bassham (CBB) cycle in order to keep the C4 pathway energetically efficient. The gradient in CO2 concentration between bundle-sheath and mesophyll cells facilitates diffusive leakage of CO2. This rate of bundle-sheath CO2 leakage relative to the rate of phosphoenolpyruvate carboxylation (termed leakiness) has been used to probe the balance between C4 carbon acquisition and subsequent reduction as a result of environmental perturbations. When doing so, the correct choice of equations to derive leakiness from stable carbon isotope discrimination (Δ(13)C) during gas exchange is critical to avoid biased results. Leakiness responses to photon flux density, either short-term (during measurements) or long-term (during growth and development), can have important implications for C4 performance in understorey light conditions. However, recent reports show leakiness to be subject to considerable acclimation. Additionally, the recent discovery of two decarboxylating C4 cycles operating in parallel in Zea mays suggests that flexibility in the transported C4 acid and associated decarboxylase could also aid in maintaining C4/CBB balance in a changing environment. In this paper, we review improvements in methodology to estimate leakiness, synthesize reports on bundle-sheath leakiness, discuss different interpretations, and highlight areas where future research is necessary. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology

  9. Differential gene expression and transport functionality in the bundle sheath versus mesophyll - a potential role in leaf mineral homeostasis.

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    Wigoda, Noa; Pasmanik-Chor, Metsada; Yang, Tianyuan; Yu, Ling; Moshelion, Menachem; Moran, Nava

    2017-06-01

    Under fluctuating ambient conditions, the ability of plants to maintain hydromineral homeostasis requires the tight control of long distance transport. This includes the control of radial transport within leaves, from veins to mesophyll. The bundle sheath is a structure that tightly wraps around leaf vasculature. It has been suggested to act as a selective barrier in the context of radial transport. This suggestion is based on recent physiological transport assays of bundle sheath cells (BSCs), as well as the anatomy of these cells.We hypothesized that the unique transport functionality of BSCs is apparent in their transcriptome. To test this, we compared the transcriptomes of individually hand-picked protoplasts of GFP-labeled BSCs and non-labeled mesophyll cells (MCs) from the leaves of Arabidopsis thaliana. Of the 90 genes differentially expressed between BSCs and MCs, 45% are membrane related and 20% transport related, a prominent example being the proton pump AHA2. Electrophysiological assays showed that the major AKT2-like membrane K+ conductances of BSCs and MCs had different voltage dependency ranges. Taken together, these differences may cause simultaneous but oppositely directed transmembrane K+ fluxes in BSCs and MCs, in otherwise similar conditions. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  10. Impact of anatomical traits of maize (Zea mays L.) leaf as affected by nitrogen supply and leaf age on bundle sheath conductance.

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    Retta, Moges; Yin, Xinyou; van der Putten, Peter E L; Cantre, Denis; Berghuijs, Herman N C; Ho, Quang Tri; Verboven, Pieter; Struik, Paul C; Nicolaï, Bart M

    2016-11-01

    The mechanism of photosynthesis in C 4 crops depends on the archetypal Kranz-anatomy. To examine how the leaf anatomy, as altered by nitrogen supply and leaf age, affects the bundle sheath conductance (g bs ), maize (Zea mays L.) plants were grown under three contrasting nitrogen levels. Combined gas exchange and chlorophyll fluorescence measurements were done on fully grown leaves at two leaf ages. The measured data were analysed using a biochemical model of C 4 photosynthesis to estimate g bs . The leaf microstructure and ultrastructure were quantified using images obtained from micro-computed tomography and microscopy. There was a strong positive correlation between g bs and leaf nitrogen content (LNC) while old leaves had lower g bs than young leaves. Leaf thickness, bundle sheath cell wall thickness and surface area of bundle sheath cells per unit leaf area (S b ) correlated well with g bs although they were not significantly affected by LNC. As a result, the increase of g bs with LNC was little explained by the alteration of leaf anatomy. In contrast, the combined effect of LNC and leaf age on S b was responsible for differences in g bs between young leaves and old leaves. Future investigations should consider changes at the level of plasmodesmata and membranes along the CO 2 leakage pathway to unravel LNC and age effects further. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. Genetic instability in nerve sheath cell tumors

    DEFF Research Database (Denmark)

    Rogatto, Silvia Regina; Casartelli, Cacilda; Rainho, Claudia Aparecida

    1995-01-01

    After in vitro culture, we analyzed cytogenetically four acoustic nerve neurinomas, one intraspinal neurinoma and one neurofibroma obtainedfrom unrelated patients. Monosomy of chromosomes 22 and 16 was an abnormality common to all cases, followed in frequency by loss of chromosomes 18 (three cases...... by the presence of polyploid cells with inconsistent abnormalities, endoreduplications and telomeric associations resulting in dicentric chromosomes. It is probable that these cytogenetic abnormalities represent some kind of evolutionary advantage for the in vitro progression of nerve sheath tumors....

  12. Cell Based Meniscal Repair Using an Aligned Bioactive Nanofibrous Sheath

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    2017-07-01

    to subsequently guide tissue regeneration , for example, by seeded tissue progenitor cells . To achieve this objective, the first step is to develop...AWARD NUMBER: W81XWH-15-1-0104 TITLE: Cell -Based Meniscal Repair Using an Aligned Bioactive Nanofibrous Sheath PRINCIPAL INVESTIGATOR...SUBTITLE 5a. CONTRACT NUMBER Cell -Based Meniscal Repair Using an Aligned Bioactive Nanofibrous Sheath 5b. GRANT NUMBER W81XWH-15-1-0104 5c. PROGRAM

  13. Bilateral giant cell tumor of tendon sheath of tendoachilles

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    Soma Datta

    2014-01-01

    Full Text Available Giant cell tumor of tendon sheath arises from the synovium of tendon sheaths, joints, or bursae, mostly affects adults between 30 and 50 years of age, and is slightly more common in females. We report the case of a 32-years-old male presenting with pain in both ankles without any history of trauma. On clinical examination, tenderness on both tendoachilles and local thickening were observed. Ultrasonography showed thickening of local tendinous area with increase in anteroposterior diameter, and Doppler demonstrated increased flow in peritendinous area. MRI findings showed that most of the tumor had intermediate signal intensity and portions of the tumor had low signal intensity. Fine needle aspiration cytology confirmed the diagnosis of giant cell tumor of tendon sheath. Excision biopsy was done with no recurrence on five month follow-up. Review of literature did not reveal any similar result; so, bilateral giant cell tumor of tendon sheath of tendoachilles is a rare presentation.

  14. Measurements of Sheath Temperature Profiles in Bruce LVRF Bundles Under Post-Dryout Heat Transfer Conditions in Freon

    International Nuclear Information System (INIS)

    Guo, Y.; Bullock, D.E.; Pioro, I.L.; Martin, J.

    2006-01-01

    An experimental program has been completed to study the behaviour of sheath wall temperatures in the Bruce Power Station Low Void Reactivity Fuel (shortened hereafter to Bruce LVRF) bundles under post-dryout (PDO) heat-transfer conditions. The experiment was conducted with an electrically heated simulator of a string of nine Bruce LVRF bundles, installed in the MR-3 Freon heat transfer loop at the Chalk River Laboratories (CRL), Atomic Energy of Canada Limited (AECL). The loop used Freon R-134a as a coolant to simulate typical flow conditions in CANDU R nuclear power stations. The simulator had an axially uniform heat flux profile. Two radial heat flux profiles were tested: a fresh Bruce LVRF profile and a fresh natural uranium (NU) profile. For a given set of flow conditions, the channel power was set above the critical power to achieve dryout, while heater-element wall temperatures were recorded at various overpower levels using sliding thermocouples. The maximum experimental overpower achieved was 64%. For the conditions tested, the results showed that initial dryout occurred at an inner-ring element at low flows and an outer-ring element facing internal subchannels at high flows. Dry-patches (regions of dryout) spread with increasing channel power; maximum wall temperatures were observed at the downstream end of the simulator, and immediately upstream of the mid-bundle spacer plane. In general, maximum wall temperatures were observed at the outer-ring elements facing the internal subchannels. The maximum water-equivalent temperature obtained in the test, at an overpower level of 64%, was significantly below the acceptable maximum temperature, indicating that the integrity of the Bruce LVRF will be maintained at PDO conditions. Therefore, the Bruce LVRF exhibits good PDO heat transfer performance. (authors)

  15. Matrix remodeling between cells and cellular interactions with collagen bundle

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    Kim, Jihan; Sun, Bo

    When cells are surrounded by complex environment, they continuously probe and interact with it by applying cellular traction forces. As cells apply traction forces, they can sense rigidity of their local environment and remodel the matrix microstructure simultaneously. Previous study shows that single human carcinoma cell (MDA-MB-231) remodeled its surrounding extracellular matrix (ECM) and the matrix remodeling was reversible. In this study we examined the matrix microstructure between cells and cellular interaction between them using quantitative confocal microscopy. The result shows that the matrix microstructure is the most significantly remodeled between cells consisting of aligned, and densified collagen fibers (collagen bundle)., the result shows that collagen bundle is irreversible and significantly change micromechanics of ECM around the bundle. We further examined cellular interaction with collagen bundle by analyzing dynamics of actin and talin formation along with the direction of bundle. Lastly, we analyzed dynamics of cellular protrusion and migrating direction of cells along the bundle.

  16. Comparative proteomics of chloroplasts envelopes from bundle sheath and mesophyll chloroplasts reveals novel membrane proteins with a possible role in C4-related metabolite fluxes and development.

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    Kalpana eManandhar-Shrestha

    2013-03-01

    Full Text Available As the world population grows, our need for food increases drastically. Limited amounts of arable land lead to a competition between food and fuel crops, while changes in the global climate may impact future crop yields. Thus, a second green revolution will need a better understanding of the processes essential for plant growth and development. One approach toward the solution of this problem is to better understand regulatory and transport processes in C4 plants. C4 plants display an up to 10-fold higher apparent CO2 assimilation and higher yields while maintaining high water use efficiency. This requires differential regulation of mesophyll (M and bundle sheath (BS chloroplast development as well as higher metabolic fluxes of photosynthetic intermediates between cells and across chloroplast envelopes. While previous analyses of overall chloroplast membranes have yielded significant insight, our comparative proteomics approach using enriched BS and M chloroplast envelopes of Zea mays allowed us to identify 37 proteins of unknown function that have not been seen in these earlier studies. We identified 280 proteins, 84% of which are known/predicted to be present in chloroplasts (cp. 74% have a known or predicted membrane association. 21 membrane proteins were 2-15 times more abundant in BS cells, while 36 proteins were more abundant in M cp envelopes. These proteins could represent additional candidates of proteins essential for development or metabolite transport processes in C4 plants. RT-PCR confirmed differential expression of thirteen candidate genes. Cp association was confirmed using GFP labeling. Genes for a PIC-like protein and an ER-AP-like protein show an early transient increase in gene expression during the transition to light. In addition, PIC gene expression is increased in the immature part of the leaf and was lower in the fully developed parts of the leaf, suggesting a need for/incorporation of the protein during chloroplast

  17. Osteocalcin expressing cells from tendon sheaths in mice contribute to tendon repair by activating Hedgehog signaling

    OpenAIRE

    Wang, Yi; Zhang, Xu; Huang, Huihui; Xia, Yin; Yao, YiFei; Mak, Arthur Fuk-Tat; Yung, Patrick Shu-Hang; Chan, Kai-Ming; Wang, Li; Zhang, Chenglin; Huang, Yu; Mak, Kingston King-Lun

    2017-01-01

    Both extrinsic and intrinsic tissues contribute to tendon repair, but the origin and molecular functions of extrinsic tissues in tendon repair are not fully understood. Here we show that tendon sheath cells harbor stem/progenitor cell properties and contribute to tendon repair by activating Hedgehog signaling. We found that Osteocalcin (Bglap) can be used as an adult tendon-sheath-specific marker in mice. Lineage tracing experiments show that Bglap-expressing cells in adult sheath tissues pos...

  18. Giant Cell Tumour of Tendon Sheath Masquerading As Trigger Finger

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    N Rahimawati

    2010-11-01

    Full Text Available We report a case of a 59-year-old female who presented in the general orthopaedic clinic with triggering of her right middle finger. She did not respond to conventional treatment methods; subsequently she underwent surgical open release under local anaesthesia. Five months postoperatively, the patient presented with signs and symptoms of acute flexor tenosynovitis, and was thought to have a postoperative infection. Re-examination by a hand surgeon raised the possibility of a different aetiology. Based on clinical findings and response to initial treatment, giant cell tumour of the flexor tendon sheath was suspected and later confirmed following surgical biopsy. A high index of suspicion and knowledge of the variegated presentations of giant cell tumour in the hand are beneficial in these types of cases.

  19. Interconnection of bundled solid oxide fuel cells

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    Brown, Michael; Bessette, II, Norman F; Litka, Anthony F; Schmidt, Douglas S

    2014-01-14

    A system and method for electrically interconnecting a plurality of fuel cells to provide dense packing of the fuel cells. Each one of the plurality of fuel cells has a plurality of discrete electrical connection points along an outer surface. Electrical connections are made directly between the discrete electrical connection points of adjacent fuel cells so that the fuel cells can be packed more densely. Fuel cells have at least one outer electrode and at least one discrete interconnection to an inner electrode, wherein the outer electrode is one of a cathode and and anode and wherein the inner electrode is the other of the cathode and the anode. In tubular solid oxide fuel cells the discrete electrical connection points are spaced along the length of the fuel cell.

  20. The endomembrane sheath: a key structure for understanding the plant cell?

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    Reuzeau, C.; McNally, J. G.; Pickard, B. G.

    1997-01-01

    Recent evidence suggests that integrin is abundant in endomembranes of plant cells, and the endomembranes are clad by a sheath of cytoskeleton including F-actin. A role for endomembrane integrin and the endomembrane sheath is proposed: this system might orchestrate metabolic regulation by providing and modulating loci for channelling, and might accelerate channeling as needed by dragging the endoplasmic reticulum (ER) and organelles through the cytoplasm. To accomplish this "streaming", F-actin might lever against the rest of the endomembrane sheath and the ER might also lever against adhesion sites (i.e., plasmodesmata and plasmalemmal control centers). As an important agent in the control of cellular activities, according to this model, the endomembrane sheath would play a major part in responses to diverse signals and stresses, and under extreme stress cell survival would depend on the ability of the system to maintain enough integrity to direct critical syntheses and degradations.

  1. A smart core-sheath nanofiber that captures and releases red blood cells from the blood

    Science.gov (United States)

    Shi, Q.; Hou, J.; Zhao, C.; Xin, Z.; Jin, J.; Li, C.; Wong, S.-C.; Yin, J.

    2016-01-01

    A smart core-sheath nanofiber for non-adherent cell capture and release is demonstrated. The nanofibers are fabricated by single-spinneret electrospinning of poly(N-isopropylacrylamide) (PNIPAAm), polycaprolactone (PCL) and nattokinase (NK) solution blends. The self-assembly of PNIPAAm and PCL blends during the electrospinning generates the core-sheath PCL/PNIPAAm nanofibers with PNIPAAm as the sheath. The PNIPAAm-based core-sheath nanofibers are switchable between hydrophobicity and hydrophilicity with temperature change and enhance stability in the blood. When the nanofibers come in contact with blood, the NK is released from the nanofibers to resist platelet adhesion on the nanofiber surface, facilitating the direct capture and isolation of red blood cells (RBCs) from the blood above phase-transition temperature of PNIPAAm. Meanwhile, the captured RBCs are readily released from the nanofibers with temperature stimuli in an undamaged manner. The release efficiency of up to 100% is obtained while maintaining cellular integrity and function. This work presents promising nanofibers to effectively capture non-adherent cells and release for subsequent molecular analysis and diagnosis of single cells.A smart core-sheath nanofiber for non-adherent cell capture and release is demonstrated. The nanofibers are fabricated by single-spinneret electrospinning of poly(N-isopropylacrylamide) (PNIPAAm), polycaprolactone (PCL) and nattokinase (NK) solution blends. The self-assembly of PNIPAAm and PCL blends during the electrospinning generates the core-sheath PCL/PNIPAAm nanofibers with PNIPAAm as the sheath. The PNIPAAm-based core-sheath nanofibers are switchable between hydrophobicity and hydrophilicity with temperature change and enhance stability in the blood. When the nanofibers come in contact with blood, the NK is released from the nanofibers to resist platelet adhesion on the nanofiber surface, facilitating the direct capture and isolation of red blood cells (RBCs) from

  2. Electromagnetic particle in cell modeling of the plasma focus: Current sheath formation and lift off

    International Nuclear Information System (INIS)

    Seng, Y. S.; Lee, P.; Rawat, R. S.

    2014-01-01

    The shaping and formation of the current sheath takes place in the breakdown phase of a plasma focus device and critically controls the device performance. Electrostatic particle in cell codes, with magnetic effects ignored, have been used to model the breakdown phase. This Letter reports the successful development and implementation of an electromagnetic particle in cell (EMPIC) code, including magnetic effects self-consistently, to simulate the breakdown phase; from the ionization, localization and gliding discharge along the insulator to the time instant of current sheath lift off. The magnetic field was found to be appreciable from the time the current sheath came into contact with the anode with increased local current, initiating the voltage breakdown of the device as a result

  3. Wilms Tumor 1b defines a wound-specific sheath cell subpopulation associated with notochord repair

    Science.gov (United States)

    Lopez-Baez, Juan Carlos; Zeng, Zhiqiang; Brunsdon, Hannah; Salzano, Angela; Brombin, Alessandro; Wyatt, Cameron; Rybski, Witold; Huitema, Leonie F A; Dale, Rodney M; Kawakami, Koichi; Englert, Christoph; Chandra, Tamir; Schulte-Merker, Stefan

    2018-01-01

    Regenerative therapy for degenerative spine disorders requires the identification of cells that can slow down and possibly reverse degenerative processes. Here, we identify an unanticipated wound-specific notochord sheath cell subpopulation that expresses Wilms Tumor (WT) 1b following injury in zebrafish. We show that localized damage leads to Wt1b expression in sheath cells, and that wt1b+cells migrate into the wound to form a stopper-like structure, likely to maintain structural integrity. Wt1b+sheath cells are distinct in expressing cartilage and vacuolar genes, and in repressing a Wt1b-p53 transcriptional programme. At the wound, wt1b+and entpd5+ cells constitute separate, tightly-associated subpopulations. Surprisingly, wt1b expression at the site of injury is maintained even into adult stages in developing vertebrae, which form in an untypical manner via a cartilage intermediate. Given that notochord cells are retained in adult intervertebral discs, the identification of novel subpopulations may have important implications for regenerative spine disorder treatments. PMID:29405914

  4. The study of sheath flow dark zone phenomenon in dynamic individual cells scattering measurement

    Science.gov (United States)

    Zhang, Lu; Zhao, Hong; Wang, Xiaopin; Zhang, Weiguang

    2008-09-01

    Dynamic cells scattering is one of the most efficient approaches exploring in measurements of cells size, morphology and growth states. This technique can be widely applied in real-time detection for pharmaceutical industry, food industry, liquor industry and other biological fields. A novel method named dynamic individual cells scattering measurement is designed in this paper, which can make cells pass through quartz glass measurement zone one by one with sheath flow driving force. During the experiments, an obvious phenomenon has been found which is called sheath flow dark zone phenomenon (SFDZ). Under the influence of SFDZ, sheath flow forming detection becomes very difficult. In this paper, the causes giving rise to SFDZ have been analyzed. And an improved method is put forward, in which the orifice inside the measurement zone is set as an optical system. Then the illuminating system is redesigned. In this way, almost all the illuminating light can enter orifice so that the total reflection energy decreases substantially. A comparison experiments have been done, which proves the efficiency of this redesigned optical system and its sound effects on SFDZ avoiding.

  5. Giant cell tumour of tendon sheath and synovial membrane: A review of 26 cases.

    Science.gov (United States)

    Kant, Kumar Shashi; Manav, Ajoy Kumar; Kumar, Rakesh; Abhinav; Sinha, Vishvendra Kumar; Sharma, Akshat

    2017-11-01

    Aim of our study is to highlight the incidence and benign nature of Giant cell tumour of tendon sheath and need for complete removal, thus minimizing the chances of recurrence. A total of 26 cases of Giant cell tumour of tendon sheath operated in the department of Orthopaedics, Patna Medical College & Hospital, Patna from 2003 to 2010 were included in this study. The surgery was performed after clinical evaluation of the lesion and Fine Needle Aspiration Cytology (FNAC). The tumour underwent en bloc marginal excision. The patients were followed up for minimum two year. Our study population consisted of 18 females and 8 males. The mean age at the time of surgery was 38.3 years (range, 18-62 years). Twenty three cases were found in the 3rd and 4th decade. Twenty two cases involved upper extremity and only 4 cases in lower extremity. MRI was done in 2 cases where diagnosis was in doubt. Bony indentation on X-ray film was found in 7 cases and thorough curettage of cortical shell was done. All the cases were treated by marginal excision. Three cases developed post-operative stiffness but regained full range of movement with physiotherapy. Sensory impairment was seen in 3 cases. Recurrence occurred in 2 case and they were treated by repeat marginal excision. Meticulous en-masse marginal excision of the giant cell tumour of tendon sheath in blood less field using magnification is the treatment of choice.

  6. A Case of Basal Cell Carcinoma with Outer Hair Follicle Sheath Differentiation

    Directory of Open Access Journals (Sweden)

    Masazumi Onishi

    2015-12-01

    Full Text Available A 70-year-old Japanese man presented at our hospital with an asymptomatic, blackish, irregularly shaped plaque with a gray nodule in the periphery on his left lower leg. The lesion had been present for 10 years and had recently enlarged, associated with bleeding. Histopathologically, the tumor consisted of three distinct parts: The first part showed massive aggregation of basophilic basaloid cells with peripheral palisading and abundant melanin granules, and was diagnosed as solid-type basal cell carcinoma. The second part showed aggregation of clear cells with squamous eddies, and was diagnosed as proliferating trichilemmal tumor. The third part showed reticular aggregation of basaloid cells with infundibular cysts in the papillary dermis, and was diagnosed as infundibulocystic basal cell carcinoma. We diagnosed this tumor as basal cell carcinoma with various forms of hair follicle differentiation, including differentiation into the outer root sheath.

  7. Does the peritumoral stroma of basal cell carcinoma recapitulate the follicular connective tissue sheath?

    Science.gov (United States)

    Sellheyer, Klaus; Krahl, Dieter

    2011-07-01

    There are compelling embryologic and anatomic relationships within adnexal tumors. However, these are mostly perceived within the epithelial component while the stromal component of the tumors is frequently overlooked. In postnatal skin, nestin is almost exclusively expressed in the perifollicular mesenchyme. This study examines the expression of this neuroepithelial stem cell protein in trichoblastoma/trichoepithelioma and in basal cell carcinoma (BCC), which is increasingly being viewed as follicular in nature. We employed standard immunohistochemical methods with three different antibodies to examine the expression of nestin in 25 BCCs and compared the staining pattern with that of 7 trichoblastomas and 11 trichoepitheliomas. Nestin is expressed in the peritumoral stroma of all tumors examined and is limited to the immediate layer of mesenchymal cells surrounding the tumor epithelium. In BCC, nestin-immunoreactive cells are found as a sheath of thin, spindled fibroblasts, while reactive cells are plump in trichoepitheliomas/trichoblastomas. We postulate that the peritumoral stroma of BCC imitates the perifollicular connective tissue sheath, while in contrast that of trichoepithelioma/trichoblastoma is similar to the papillary and immediate peripapillary follicular mesenchyme. Further functional and animal experimental studies are needed to test this hypothesis. Copyright © 2011 John Wiley & Sons A/S.

  8. Fast wave experiments in LAPD: RF sheaths, convective cells and density modifications

    Science.gov (United States)

    Carter, T. A.; van Compernolle, B.; Martin, M.; Gekelman, W.; Pribyl, P.; van Eester, D.; Crombe, K.; Perkins, R.; Lau, C.; Martin, E.; Caughman, J.; Tripathi, S. K. P.; Vincena, S.

    2017-10-01

    An overview is presented of recent work on ICRF physics at the Large Plasma Device (LAPD) at UCLA. The LAPD has typical plasma parameters ne 1012 -1013 cm-3, Te 1 - 10 eV and B 1000 G. A new high-power ( 150 kW) RF system and fast wave antenna have been developed for LAPD. The source runs at a frequency of 2.4 MHz, corresponding to 1 - 7fci , depending on plasma parameters. Evidence of rectified RF sheaths is seen in large increases ( 10Te) in the plasma potential on field lines connected to the antenna. The rectified potential scales linearly with antenna current. The rectified RF sheaths set up convective cells of local E × B flows, measured indirectly by potential measurements, and measured directly with Mach probes. At high antenna powers substantial modifications of the density profile were observed. The plasma density profile initially exhibits transient low frequency oscillations (10 kHz). The amplitude of the fast wave fields in the core plasma is modulated at the same low frequency, suggesting fast wave coupling is affected by the density rearrangement. Work performed at the Basic Plasma Science Facility, supported jointly by the National Science Foundation and the Department of Energy.

  9. Eps8 regulates hair bundle length and functional maturation of mammalian auditory hair cells.

    Directory of Open Access Journals (Sweden)

    Valeria Zampini

    2011-04-01

    Full Text Available Hair cells of the mammalian cochlea are specialized for the dynamic coding of sound stimuli. The transduction of sound waves into electrical signals depends upon mechanosensitive hair bundles that project from the cell's apical surface. Each stereocilium within a hair bundle is composed of uniformly polarized and tightly packed actin filaments. Several stereociliary proteins have been shown to be associated with hair bundle development and function and are known to cause deafness in mice and humans when mutated. The growth of the stereociliar actin core is dynamically regulated at the actin filament barbed ends in the stereociliary tip. We show that Eps8, a protein with actin binding, bundling, and barbed-end capping activities in other systems, is a novel component of the hair bundle. Eps8 is localized predominantly at the tip of the stereocilia and is essential for their normal elongation and function. Moreover, we have found that Eps8 knockout mice are profoundly deaf and that IHCs, but not OHCs, fail to mature into fully functional sensory receptors. We propose that Eps8 directly regulates stereocilia growth in hair cells and also plays a crucial role in the physiological maturation of mammalian cochlear IHCs. Together, our results indicate that Eps8 is critical in coordinating the development and functionality of mammalian auditory hair cells.

  10. Eps8 regulates hair bundle length and functional maturation of mammalian auditory hair cells.

    Science.gov (United States)

    Zampini, Valeria; Rüttiger, Lukas; Johnson, Stuart L; Franz, Christoph; Furness, David N; Waldhaus, Jörg; Xiong, Hao; Hackney, Carole M; Holley, Matthew C; Offenhauser, Nina; Di Fiore, Pier Paolo; Knipper, Marlies; Masetto, Sergio; Marcotti, Walter

    2011-04-01

    Hair cells of the mammalian cochlea are specialized for the dynamic coding of sound stimuli. The transduction of sound waves into electrical signals depends upon mechanosensitive hair bundles that project from the cell's apical surface. Each stereocilium within a hair bundle is composed of uniformly polarized and tightly packed actin filaments. Several stereociliary proteins have been shown to be associated with hair bundle development and function and are known to cause deafness in mice and humans when mutated. The growth of the stereociliar actin core is dynamically regulated at the actin filament barbed ends in the stereociliary tip. We show that Eps8, a protein with actin binding, bundling, and barbed-end capping activities in other systems, is a novel component of the hair bundle. Eps8 is localized predominantly at the tip of the stereocilia and is essential for their normal elongation and function. Moreover, we have found that Eps8 knockout mice are profoundly deaf and that IHCs, but not OHCs, fail to mature into fully functional sensory receptors. We propose that Eps8 directly regulates stereocilia growth in hair cells and also plays a crucial role in the physiological maturation of mammalian cochlear IHCs. Together, our results indicate that Eps8 is critical in coordinating the development and functionality of mammalian auditory hair cells.

  11. Giant cell tumor of the tendon sheath of the hand - magnetic resonance image and orthopaedic treatment

    International Nuclear Information System (INIS)

    Kirova, G.; Monovska, T.; Jablanski, V.; Alexieva, K.; Velev, M.

    2009-01-01

    Giant cell tumour of the tendon sheath (GCT-TS), also known as localized nodular tenosynovitis, is a benign neoplasm that occurs dominantly on the digits. These tumours most commonly occur in patients aged 30-50 years and are associated with degenerative joint disease. GCT-TS usually arises from the synovium of tendon sheets, affecting interfalangeal joints of the hand, feet, ankle and knees. Magnetic Resonance Imaging is able to depict characteristic signal intensities and can accurately assess the tumor size and degree of extent around the phalanx. We present a case of a 36 years-old male patient with GCT-TS in the flexor tendon of his left second finger, diagnosed with Magnetic Resonance imaging. The mass was excised widely with preservation of the flexor tendon without recurrence. (authors)

  12. Hair Follicle Dermal Sheath Derived Cells Improve Islet Allograft Survival without Systemic Immunosuppression

    Directory of Open Access Journals (Sweden)

    Xiaojie Wang

    2015-01-01

    Full Text Available Immunosuppressive drugs successfully prevent rejection of islet allografts in the treatment of type I diabetes. However, the drugs also suppress systemic immunity increasing the risk of opportunistic infection and cancer development in allograft recipients. In this study, we investigated a new treatment for autoimmune diabetes using naturally immune privileged, hair follicle derived, autologous cells to provide localized immune protection of islet allotransplants. Islets from Balb/c mouse donors were cotransplanted with syngeneic hair follicle dermal sheath cup cells (DSCC, group 1 or fibroblasts (FB, group 2 under the kidney capsule of immune-competent, streptozotocin induced, diabetic C57BL/6 recipients. Group 1 allografts survived significantly longer than group 2 (32.2 ± 12.2 versus 14.1 ± 3.3 days, P<0.001 without administration of any systemic immunosuppressive agents. DSCC reduced T cell activation in the renal lymph node, prevented graft infiltrates, modulated inflammatory chemokine and cytokine profiles, and preserved better beta cell function in the islet allografts, but no systemic immunosuppression was observed. In summary, DSCC prolong islet allograft survival without systemic immunosuppression by local modulation of alloimmune responses, enhancing of beta cell survival, and promoting of graft revascularization. This novel finding demonstrates the capacity of easily accessible hair follicle cells to be used as local immunosuppression agents in islet transplantation.

  13. Expression patterns of cell cycle components in sporadic and neurofibromatosis type 1-related malignant peripheral nerve sheath tumors

    NARCIS (Netherlands)

    Agesen, Trude Holmeide; Florenes, Viva Ann; Molenaar, Willemina M.; Lind, Guro E.; Berner, Jeane-Marie; Plaat, Boudewijn E.C.; Komdeur, Rudy; Myklebost, Ola; van den Berg, Eva; Lothe, Ragnhild A.

    The molecular biology underlying the development of highly malignant peripheral nerve sheath tumors (MPNSTs) remains mostly unknown. In the present study, the expression pattern of 10 selected cell cycle components is investigated in a series of 15 MPNSTs from patients with (n = 9) or without (n =

  14. Giant cell tumors of the tendon sheath may present radiologically as intrinsic osseous lesions

    Energy Technology Data Exchange (ETDEWEB)

    Schepper, A.M. de; Bloem, J.L. [Leiden University Medical Center, Department of Radiology, Albinusdreef 2, P.O. Box 9600, RC Leiden (Netherlands); Hogendoorn, P.C.W. [Leiden University Medical Center, Department of Pathology, Albinusdreef 2, P.O. Box 9600, RC Leiden (Netherlands)

    2007-02-15

    The purpose of this study was to explain radiographic features of giant cell tumors of the tendon sheath (GCTTS), in particular, osseous extension, by correlating imaging findings with histology in order to increase the accuracy of radiological diagnosis. In a series of 200 consecutive osseous (pseudo) tumors of the hand, on radiography, six patients presented with an intrinsic osseous lesion caused by a histologically confirmed neighboring GCTTS. Available radiographs, computed tomography (CT), and contrast-enhanced magnetic resonance (MR) images were correlated with histology. Radiography showed osseous lesions consisting of well-defined cortical defects in four (one of whom also demonstrated cortical scalloping) and a slightly expansile, well-defined osteolytic lesion in two patients. MR obtained in four patients showed the extraosseous tumor invading/eroding bone and causing cortical scalloping (three and one patients, respectively). Extension depicted on MR was confirmed on the two available resection specimens. All lesions were polylobular (cauliflower or mushroom like) and neighbored tendon sheaths. Dense collagen and hemosiderin-loaded macrophages explained the high CT attenuation and the low MR signal intensity on T2-weighted images that was observed in all four MR and in all two CT scans. The high density of proliferative capillaries explained the marked enhancement observed in all four patients with gadolinium (Gd)-chelate-enhanced MR imaging. GCTTS is a soft tissue (pseudo) tumor that may invade bone and as a consequence mimick an intrinsic osseous lesion on radiographs. In such cases, specific MR and CT features that can be explained by histological findings can be used to suggest the correct diagnosis. (orig.)

  15. The design, calibration, and use of a water microjet for stimulating hair cell sensory hair bundles.

    Science.gov (United States)

    Saunders, J C; Szymko, Y M

    1989-11-01

    The design, calibration, and use of a noninvasive, noncontact device for stimulating hair cell hair bundles in vitro are described. This device employed a piezoelectric crystal, driven at high frequencies, to generate sinusoidal pressure in a contained fluid volume. The pressure was propagated to the tip of a glass micropipette and the oscillating water jet stimulus produced at the tip was used to stimulate sensory hair bundles. The movements of glass microbeads, caught in the oscillating pressure field of the water jet, provided a means of calibrating this stimulus. The linearity of the jet, its waveform and frequency response, the influence of pipette shape and tip diameter, as well as models to explain the operation of the water jet, are described. The use of this stimulus for measuring hair bundle micromechanics at high frequencies is then demonstrated.

  16. Cell wall and enzyme changes during the graviresponse of the leaf-sheath pulvinus of oat (Avena sativa)

    Science.gov (United States)

    Gibeaut, David M.; Karuppiah, Nadarajah; Chang, S.-R.; Brock, Thomas G.; Vadlamudi, Babu; Kim, Donghern; Ghosheh, Najati S.; Rayle, David L.; Carpita, Nicholas C.; Kaufman, Peter B.

    1990-01-01

    The graviresponse of the leaf-sheath pulvinus of oat (Avena sativa) involves an asymmetric growth response and asymmetric processes involving degradation of starch and cell wall synthesis. Cellular and biochemical events were studied by investigation of the activities of related enzymes and changes in cell walls and their constituents. It is suggested that an osmotic potential gradient acts as the driving factor for growth, while wall extensibility is a limiting factor in pulvinus growth.

  17. Verification of high voltage rf capacitive sheath models with particle-in-cell simulations

    Science.gov (United States)

    Wang, Ying; Lieberman, Michael; Verboncoeur, John

    2009-10-01

    Collisionless and collisional high voltage rf capacitive sheath models were developed in the late 1980's [1]. Given the external parameters of a single-frequency capacitively coupled discharge, plasma parameters including sheath width, electron and ion temperature, plasma density, power, and ion bombarding energy can be estimated. One-dimensional electrostatic PIC codes XPDP1 [2] and OOPD1 [3] are used to investigate plasma behaviors within rf sheaths and bulk plasma. Electron-neutral collisions only are considered for collisionless sheaths, while ion-neutral collisions are taken into account for collisional sheaths. The collisionless sheath model is verified very well by PIC simulations for the rf current-driven and voltage-driven cases. Results will be reported for collisional sheaths also. [1] M. A. Lieberman, IEEE Trans. Plasma Sci. 16 (1988) 638; 17 (1989) 338 [2] J. P. Verboncoeur, M. V. Alves, V. Vahedi, and C. K. Birdsall, J. Comp. Phys. 104 (1993) 321 [3] J. P. Verboncoeur, A. B. Langdon and N. T. Gladd, Comp. Phys. Comm. 87 (1995) 199

  18. Ultrastructure of the extracellular matrix of bovine dura mater, optic nerve sheath and sclera.

    OpenAIRE

    Raspanti, M; Marchini, M; Della Pasqua, V; Strocchi, R; Ruggeri, A

    1992-01-01

    The sclera, the outermost sheath of the optic nerve and the dura mater have been investigated histologically and ultrastructurally. Although these tissues appear very similar under the light microscope, being dense connective tissues mainly composed of collagen bundles and a limited amount of cells and elastic fibres, they exhibit subtle differences on electron microscopy. In the dura and sclera collagen appears in the form of large, nonuniform fibrils, similar to those commonly found in tend...

  19. Multilamellar structures and filament bundles are found on the cell surface during bunyavirus egress.

    Directory of Open Access Journals (Sweden)

    Laura Sanz-Sánchez

    Full Text Available Inside cells, viruses build specialized compartments for replication and morphogenesis. We observed that virus release associates with specific structures found on the surface of mammalian cells. Cultured adherent cells were infected with a bunyavirus and processed for oriented sectioning and transmission electron microscopy. Imaging of cell basal regions showed sophisticated multilamellar structures (MLS and extracellular filament bundles with attached viruses. Correlative light and electron microscopy confirmed that both MLS and filaments proliferated during the maximum egress of new viruses. MLS dimensions and structure were reminiscent of those reported for the nanostructures on gecko fingertips, which are responsible for the extraordinary attachment capacity of these lizards. As infected cells with MLS were more resistant to detachment than control cells, we propose an adhesive function for these structures, which would compensate for the loss of adherence during release of new virus progeny.

  20. Effect of Ethanol Stress on Fermentation Performance of Saccharomyces cerevisiae Cells Immobilized on Nypa fruticans Leaf Sheath Pieces

    Directory of Open Access Journals (Sweden)

    Hoang Phong Nguyen

    2015-01-01

    Full Text Available The yeast cells of Saccharomyces cerevisiae immobilized on Nypa fruticans leaf sheath pieces were tested for ethanol tolerance (0, 23.7, 47.4, 71.0 and 94.7 g/L. Increase in the initial ethanol concentration from 23.7 to 94.7 g/L decreased the average growth rate and concentration of ethanol produced by the immobilized yeast by 5.2 and 4.1 times, respectively. However, in the medium with initial ethanol concentration of 94.7 g/L, the average growth rate, glucose uptake rate and ethanol formation rate of the immobilized yeast were 3.7, 2.5 and 3.5 times, respectively, higher than those of the free yeast. The ethanol stress inhibited ethanol formation by Saccharomyces cerevisiae cells and the yeast responded to the stress by changing the fatty acid composition of cellular membrane. The adsorption of yeast cells on Nypa fruticans leaf sheath pieces of the growth medium increased the saturated fatty acid (C16:0 and C18:0 mass fraction in the cellular membrane and that improved alcoholic fermentation performance of the immobilized yeast.

  1. Mammalian Auditory Hair Cell Bundle Stiffness Affects Frequency Tuning by Increasing Coupling along the Length of the Cochlea.

    Science.gov (United States)

    Dewey, James B; Xia, Anping; Müller, Ulrich; Belyantseva, Inna A; Applegate, Brian E; Oghalai, John S

    2018-06-05

    The stereociliary bundles of cochlear hair cells convert mechanical vibrations into the electrical signals required for auditory sensation. While the stiffness of the bundles strongly influences mechanotransduction, its influence on the vibratory response of the cochlear partition is unclear. To assess this, we measured cochlear vibrations in mutant mice with reduced bundle stiffness or with a tectorial membrane (TM) that is detached from the sensory epithelium. We found that reducing bundle stiffness decreased the high-frequency extent and sharpened the tuning of vibratory responses obtained postmortem. Detaching the TM further reduced the high-frequency extent of the vibrations but also lowered the partition's resonant frequency. Together, these results demonstrate that the bundle's stiffness and attachment to the TM contribute to passive longitudinal coupling in the cochlea. We conclude that the stereociliary bundles and TM interact to facilitate passive-wave propagation to more apical locations, possibly enhancing active-wave amplification in vivo. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  2. Covisualization in living onion cells of putative integrin, putative spectrin, actin, putative intermediate filaments, and other proteins at the cell membrane and in an endomembrane sheath

    Science.gov (United States)

    Reuzeau, C.; Doolittle, K. W.; McNally, J. G.; Pickard, B. G.; Evans, M. L. (Principal Investigator)

    1997-01-01

    Covisualizations with wide-field computational optical-sectioning microscopy of living epidermal cells of the onion bulb scale have evidenced two major new cellular features. First, a sheath of cytoskeletal elements clads the endomembrane system. Similar elements clad the inner faces of punctate plasmalemmal sites interpreted as plasmalemmal control centers. One component of the endomembrane sheath and plasmalemmal control center cladding is anti-genicity-recognized by two injected antibodies against animal spectrin. Immunoblots of separated epidermal protein also showed bands recognized by these antibodies. Injected phalloidin identified F-actin with the same cellular distribution pattern, as did antibodies against intermediate-filament protein and other cytoskeletal elements known from animal cells. Injection of general protein stains demonstrated the abundance of endomembrane sheath protein. Second, the endomembrane system, like the plasmalemmal puncta, contains antigen recognized by an anti-beta 1 integrin injected into the cytoplasm. Previously, immunoblots of separated epidermal protein were shown to have a major band recognized both by this antibody prepared against a peptide representing the cytosolic region of beta 1 integrin and an antibody against the matrix region of beta 1 integrin. The latter antiboby also identified puncta at the external face of protoplasts. It is proposed that integrin and associated transmembrane proteins secure the endomembrane sheath and transmit signals between it and the lumen or matrix of the endoplasmic reticulum and organellar matrices. This function is comparable to that proposed for such transmembrane linkers in the plasmalemmal control centers, which also appear to bind cytoskeleton and a host of related molecules and transmit signals between them and the wall matrix. It is at the plasmalemmal control centers that the endoplasmic reticulum, a major component of the endomembrane system, attaches to the plasma membrane.

  3. Tin-oxide-coated single-walled carbon nanotube bundles supporting platinum electrocatalysts for direct ethanol fuel cells

    International Nuclear Information System (INIS)

    Hsu, Ryan S; Higgins, Drew; Chen Zhongwei

    2010-01-01

    Novel tin-oxide (SnO 2 )-coated single-walled carbon nanotube (SWNT) bundles supporting platinum (Pt) electrocatalysts for ethanol oxidation were developed for direct ethanol fuel cells. SnO 2 -coated SWNT (SnO 2 -SWNT) bundles were synthesized by a simple chemical-solution route. SnO 2 -SWNT bundles supporting Pt (Pt/SnO 2 -SWNTs) electrocatalysts and SWNT-supported Pt (Pt/SWNT) electrocatalysts were prepared by an ethylene glycol reduction method. The catalysts were physically characterized using TGA, XRD and TEM and electrochemically evaluated through cyclic voltammetry experiments. The Pt/SnO 2 -SWNTs showed greatly enhanced electrocatalytic activity for ethanol oxidation in acid medium, compared to the Pt/SWNT. The optimal SnO 2 loading of Pt/SnO 2 -SWNT catalysts with respect to specific catalytic activity for ethanol oxidation was also investigated.

  4. Tin-oxide-coated single-walled carbon nanotube bundles supporting platinum electrocatalysts for direct ethanol fuel cells.

    Science.gov (United States)

    Hsu, Ryan S; Higgins, Drew; Chen, Zhongwei

    2010-04-23

    Novel tin-oxide (SnO(2))-coated single-walled carbon nanotube (SWNT) bundles supporting platinum (Pt) electrocatalysts for ethanol oxidation were developed for direct ethanol fuel cells. SnO(2)-coated SWNT (SnO(2)-SWNT) bundles were synthesized by a simple chemical-solution route. SnO(2)-SWNT bundles supporting Pt (Pt/SnO(2)-SWNTs) electrocatalysts and SWNT-supported Pt (Pt/SWNT) electrocatalysts were prepared by an ethylene glycol reduction method. The catalysts were physically characterized using TGA, XRD and TEM and electrochemically evaluated through cyclic voltammetry experiments. The Pt/SnO(2)-SWNTs showed greatly enhanced electrocatalytic activity for ethanol oxidation in acid medium, compared to the Pt/SWNT. The optimal SnO(2) loading of Pt/SnO(2)-SWNT catalysts with respect to specific catalytic activity for ethanol oxidation was also investigated.

  5. Supramolecular assembly of biological molecules purified from bovine nerve cells: from microtubule bundles and necklaces to neurofilament networks

    International Nuclear Information System (INIS)

    Needleman, Daniel J; Jones, Jayna B; Raviv, Uri; Ojeda-Lopez, Miguel A; Miller, H P; Li, Y; Wilson, L; Safinya, C R

    2005-01-01

    With the completion of the human genome project, the biosciences community is beginning the daunting task of understanding the structures and functions of a large number of interacting biological macromolecules. Examples include the interacting molecules involved in the process of DNA condensation during the cell cycle, and in the formation of bundles and networks of filamentous actin proteins in cell attachment, motility and cytokinesis. In this proceedings paper we present examples of supramolecular assembly based on proteins derived from the vertebrate nerve cell cytoskeleton. The axonal cytoskeleton in vertebrate neurons provides a rich example of bundles and networks of neurofilaments, microtubules (MTs) and filamentous actin, where the nature of the interactions, structures, and structure-function correlations remains poorly understood. We describe synchrotron x-ray diffraction, electron microscopy, and optical imaging data, in reconstituted protein systems purified from bovine central nervous system, which reveal unexpected structures not predicted by current electrostatic theories of polyelectrolyte bundling, including three-dimensional MT bundles and two-dimensional MT necklaces

  6. Assessments of sheath strain and fission gas release data from 20 years of power reactor fuel irradiations

    International Nuclear Information System (INIS)

    Purdy, P.L.; Manzer, A.M.; Hu, R.H.; Gibb, R.A.; Kohn, E.

    1997-01-01

    Over the past 20 years, many fuel elements or bundles discharged from Canadian CANDU power reactors have been examined in the AECL hot cells. The post-irradiation examination (PIE) database covers a wide range of operating conditions, from which fuel performance characteristics can be assessed. In the present analysis, a PIE database was compiled representing elements from a total of 129 fuel bundles, of which 26% (34 bundles) were confirmed to have one or more defective elements. This comprehensive database was assessed in terms of measured sheath strain and fission gas release (FGR) for intact elements, in an attempt to identify any changes in these parameters over the history of CANDU reactor operation. Results from this assessment indicate that, for the data that are typical of normal CANDU operating conditions, tensile sheath strain and FGR have remained within 0.5% and 8%, respectively. Those data beyond these ranges are from fuel operated under abnormal conditions, not representative of normal operation, and thus do not indicate a trend toward unexpected fuel behaviour. The distributions of the PIE measurements indicate that maximum expected sheath strains and FGR for normally operated fuel are 0.7% and 13%, respectively. (author)

  7. Communication through plasma sheaths

    International Nuclear Information System (INIS)

    Korotkevich, A. O.; Newell, A. C.; Zakharov, V. E.

    2007-01-01

    We wish to transmit messages to and from a hypersonic vehicle around which a plasma sheath has formed. For long distance transmission, the signal carrying these messages must be necessarily low frequency, typically 2 GHz, to which the plasma sheath is opaque. The idea is to use the plasma properties to make the plasma sheath appear transparent

  8. Polyelectrolyte bundles

    Energy Technology Data Exchange (ETDEWEB)

    Limbach, H J; Sayar, M; Holm, C [Max-Planck-Institut fuer Polymerforschung, Ackermannweg 10, 55128 Mainz (Germany)

    2004-06-09

    Using extensive molecular dynamics simulations we study the behaviour of polyelectrolytes with hydrophobic side chains, which are known to form cylindrical micelles in aqueous solution. We investigate the stability of such bundles with respect to hydrophobicity, the strength of the electrostatic interaction and the bundle size. We show that for the parameter range relevant for sulfonated poly(para-phenylenes) (PPP) one finds a stable finite bundle size. In a more generic model we also show the influence of the length of the precursor oligomer on the stability of the bundles. We also point out that our model has close similarities to DNA solutions with added condensing agents, hinting at the possibility that the size of DNA aggregates is, under certain circumstances, thermodynamically limited.

  9. Polyelectrolyte bundles

    International Nuclear Information System (INIS)

    Limbach, H J; Sayar, M; Holm, C

    2004-01-01

    Using extensive molecular dynamics simulations we study the behaviour of polyelectrolytes with hydrophobic side chains, which are known to form cylindrical micelles in aqueous solution. We investigate the stability of such bundles with respect to hydrophobicity, the strength of the electrostatic interaction and the bundle size. We show that for the parameter range relevant for sulfonated poly(para-phenylenes) (PPP) one finds a stable finite bundle size. In a more generic model we also show the influence of the length of the precursor oligomer on the stability of the bundles. We also point out that our model has close similarities to DNA solutions with added condensing agents, hinting at the possibility that the size of DNA aggregates is, under certain circumstances, thermodynamically limited

  10. Polyelectrolyte bundles

    Science.gov (United States)

    Limbach, H. J.; Sayar, M.; Holm, C.

    2004-06-01

    Using extensive Molecular Dynamics simulations we study the behavior of polyelectrolytes with hydrophobic side chains, which are known to form cylindrical micelles in aqueous solution. We investigate the stability of such bundles with respect to hydrophobicity, the strength of the electrostatic interaction, and the bundle size. We show that for the parameter range relevant for sulfonated poly-para-phenylenes (PPP) one finds a stable finite bundle size. In a more generic model we also show the influence of the length of the precursor oligomer on the stability of the bundles. We also point out that our model has close similarities to DNA solutions with added condensing agents, hinting to the possibility that the size of DNA aggregates is under certain circumstances thermodynamically limited.

  11. Ultrastructure of the extracellular matrix of bovine dura mater, optic nerve sheath and sclera.

    Science.gov (United States)

    Raspanti, M; Marchini, M; Della Pasqua, V; Strocchi, R; Ruggeri, A

    1992-10-01

    The sclera, the outermost sheath of the optic nerve and the dura mater have been investigated histologically and ultrastructurally. Although these tissues appear very similar under the light microscope, being dense connective tissues mainly composed of collagen bundles and a limited amount of cells and elastic fibres, they exhibit subtle differences on electron microscopy. In the dura and sclera collagen appears in the form of large, nonuniform fibrils, similar to those commonly found in tendons, while in the optic nerve sheath the fibrils appear smaller and uniform, similar to those commonly observed in reticular tissues, vessel walls and skin. Freeze-fracture also reveals these fibrils to have different subfibrillar architectures, straight or helical, which correspond to 2 distinct forms of collagen fibril previously described (Raspanti et al. 1989). The other extracellular matrix components also vary with the particular collagen fibril structure. Despite their common embryological derivation, the dura mater, optic nerve sheath and sclera exhibit diversification of their extracellular matrix consistent with the mechanical loads to which these tissues are subjected. Our observations indicate that the outermost sheath of the optic nerve resembles the epineurium of peripheral nerves rather than the dura to which it is commonly likened.

  12. Cell-Based Meniscal Repair Using an Aligned Bioactive Nanofibrous Sheath

    Science.gov (United States)

    2016-07-01

    Engineering . Overlap: None Title: “Development of Novel Bioartificial Ligament Using Autologous Biological Scaffold and Cells” Grant#: W81XWH-13-2-0030...patient to rapid joint degeneration (i.e., osteoarthritis). Tissue engineering approaches, including the combination of cells, scaffolds, and...electrospun nano/microfibers comprising engineered scaffolds can mimic the ultrastructure of the native meniscal extracellular matrix (ECM); when seeded with

  13. Fuel cell integral bundle assembly including ceramic open end seal and vertical and horizontal thermal expansion control

    Science.gov (United States)

    Zafred, Paolo R [Murrysville, PA; Gillett, James E [Greensburg, PA

    2012-04-24

    A plurality of integral bundle assemblies contain a top portion with an inlet fuel plenum and a bottom portion containing a base support, the base supports a dense, ceramic air exhaust manifold having four supporting legs, the manifold is below and connects to air feed tubes located in a recuperator zone, the air feed tubes passing into the center of inverted, tubular, elongated, hollow electrically connected solid oxide fuel cells having an open end above a combustion zone into which the air feed tubes pass and a closed end near the inlet fuel plenum, where the open end of the fuel cells rest upon and within a separate combination ceramic seal and bundle support contained in a ceramic support casting, where at least one flexible cushion ceramic band seal located between the recuperator and fuel cells protects and controls horizontal thermal expansion, and where the fuel cells operate in the fuel cell mode and where the base support and bottom ceramic air exhaust manifolds carry from 85% to all of the weight of the generator.

  14. Imaging in a case of giant cell tumor of tendon sheath in foot: A case report with re-view of literature

    Directory of Open Access Journals (Sweden)

    Sujata Patnaik

    2014-07-01

    Full Text Available Large sized Giant cell tumors (GCT of the tendon sheaths of the foot are rare. We present a case with a large tumor over the dor-sum of foot which was diagnosed and studied by plain radiog-raphy, Ultrasound, CT and MRI scans. It was histologically con-firmed on biopsy. When the size of the tumor (like Giant cell tu-mor is too large and spread over multiple bones of the foot MRI is the imaging modality of choice to precisely define the anatomy to help in taking surgical decisions.

  15. Three-dimensional analysis of antenna sheaths

    International Nuclear Information System (INIS)

    Myra, J.R.; D'Ippolito, D.A.; Ho, Y.L.

    1996-01-01

    The present work is motivated by the importance of r.f. sheaths in determining the antenna-plasma interaction and the sensitivity of the sheaths to the complicated three-dimensional structure of modern ion cyclotron range of frequency (ICRF) antennas. To analyze r.f. sheaths on the plasma facing regions of the launcher, we first calculate the contact points of the tokamak magnetic field lines on the surface of the antenna Faraday screen and nearby limiters for realistic three-dimensional magnetic flux surface and antenna geometries. Next, the r.f. voltage that can drive sheaths at the contact points is determined and used to assess the resulting sheath power dissipation, r.f.-driven sputtering, and r.f.-induced convective cells (which produce edge profile modification). The calculations are embodied in a computer code, ANSAT (antenna sheath analysis tool), and sample ANSAT runs are shown to highlight the physics- and geometry-dependent characteristics of the r.f. sheaths and their relationship to the antenna design. One use of ANSAT is therefore as a design tool, to assess the strengths and weaknesses of a given design with respect to critical voltage handling and edge plasma interaction issues. Additionally, examples are presented where ANSAT has been useful in the analysis and interpretation of ICRF experiments (orig.)

  16. A Genome-wide RNAi Screen for Microtubule Bundle Formation and Lysosome Motility Regulation in Drosophila S2 Cells

    Directory of Open Access Journals (Sweden)

    Amber L. Jolly

    2016-01-01

    Full Text Available Long-distance intracellular transport of organelles, mRNA, and proteins (“cargo” occurs along the microtubule cytoskeleton by the action of kinesin and dynein motor proteins, but the vast network of factors involved in regulating intracellular cargo transport are still unknown. We capitalize on the Drosophila melanogaster S2 model cell system to monitor lysosome transport along microtubule bundles, which require enzymatically active kinesin-1 motor protein for their formation. We use an automated tracking program and a naive Bayesian classifier for the multivariate motility data to analyze 15,683 gene phenotypes and find 98 proteins involved in regulating lysosome motility along microtubules and 48 involved in the formation of microtubule filled processes in S2 cells. We identify innate immunity genes, ion channels, and signaling proteins having a role in lysosome motility regulation and find an unexpected relationship between the dynein motor, Rab7a, and lysosome motility regulation.

  17. Zebrafish Models for the Mechanosensory Hair Cell Dysfunction in Usher Syndrome 3 Reveal That Clarin-1 Is an Essential Hair Bundle Protein.

    Science.gov (United States)

    Gopal, Suhasini R; Chen, Daniel H-C; Chou, Shih-Wei; Zang, Jingjing; Neuhauss, Stephan C F; Stepanyan, Ruben; McDermott, Brian M; Alagramam, Kumar N

    2015-07-15

    Usher syndrome type III (USH3) is characterized by progressive loss of hearing and vision, and varying degrees of vestibular dysfunction. It is caused by mutations that affect the human clarin-1 protein (hCLRN1), a member of the tetraspanin protein family. The missense mutation CLRN1(N48K), which affects a conserved N-glycosylation site in hCLRN1, is a common causative USH3 mutation among Ashkenazi Jews. The affected individuals hear at birth but lose that function over time. Here, we developed an animal model system using zebrafish transgenesis and gene targeting to provide an explanation for this phenotype. Immunolabeling demonstrated that Clrn1 localized to the hair cell bundles (hair bundles). The clrn1 mutants generated by zinc finger nucleases displayed aberrant hair bundle morphology with diminished function. Two transgenic zebrafish that express either hCLRN1 or hCLRN1(N48K) in hair cells were produced to examine the subcellular localization patterns of wild-type and mutant human proteins. hCLRN1 localized to the hair bundles similarly to zebrafish Clrn1; in contrast, hCLRN1(N48K) largely mislocalized to the cell body with a small amount reaching the hair bundle. We propose that this small amount of hCLRN1(N48K) in the hair bundle provides clarin-1-mediated function during the early stages of life; however, the presence of hCLRN1(N48K) in the hair bundle diminishes over time because of intracellular degradation of the mutant protein, leading to progressive loss of hair bundle integrity and hair cell function. These findings and genetic tools provide an understanding and path forward to identify therapies to mitigate hearing loss linked to the CLRN1 mutation. Mutations in the clarin-1 gene affect eye and ear function in humans. Individuals with the CLRN1(N48K) mutation are born able to hear but lose that function over time. Here, we develop an animal model system using zebrafish transgenesis and gene targeting to provide an explanation for this phenotype

  18. Tumor de células gigantes de bainha de tendão no LCA Tendon sheath giant cells tumor in ACL

    Directory of Open Access Journals (Sweden)

    André Pedrinelli

    2007-01-01

    Full Text Available Trata-se de um relato de caso de tumor de células gigantes de bainha do ligamento cruzado anterior, uma localização extremamente rara para esse tipo de lesão. O paciente do sexo feminino apresentava dor no joelho, sem relato de trauma anterior. Foi submetido ao exame clínico, ao estudo radiográfico e de ressonância magnética da região. Feita a hipótese diagnóstica de TGC de Bainha, o paciente foi então tratado com ressecção artroscópica do tumor. O diagnóstico foi confirmado com exame anátomo-patológico. O paciente evoluiu bem, com melhora dos sintomas referidos no pré-operatório.The author presents a case report of Tumor Giant Cells (TGC localized on the anterior cruciate ligament sheath, an extremely rare site for this kind of lesion. A 37 y-o female patient presented with knee pain, with no history of previous trauma. She underwent clinical examination, X-ray study and magnetic resonance of the region. The diagnostic hypothesis of Sheath TGC was provided, and the patient was treated with tumor arthroscopy resection. Diagnosis was confirmed by anatomicopathological examination. By the end point assessment, none of the pre-operative symptoms were reported.

  19. Theory of the Electron Sheath and Presheath

    Science.gov (United States)

    Scheiner, Brett; Baalrud, Scott; Yee, Benjamin; Hopkins, Matthew; Barnat, Edward

    2015-09-01

    Electron sheaths are commonly found near Langmuir probes collecting the electron saturation current. The common assumption is that the probe collects the random flux of electrons incident on the sheath, which tacitly implies that there is no electron presheath and that the flux collected is due to a velocity space truncation of the velocity distribution function (VDF). This work provides a dedicated theory of electron sheaths, which suggests that electron sheaths are not so simple. Motivated by VDFs observed in recent Particle-In-Cell (PIC) simulations, we develop a 1D model for the electron sheath and presheath. In the model, under low temperature plasma conditions, an electron pressure gradient accelerates electrons in the presheath to a flow velocity that exceeds the electron thermal speed at the sheath edge. This pressure gradient allows the generation of large flows compared to those that would be generated by the electric field alone. It is due to this pressure gradient that the electron presheath extends much further into the plasma (nominally by a factor of √{mi /me }) than an analogous ion presheath. Results of the model are compared with PIC simulations. This work was supported by the Office of Fusion Energy Science at the U.S. Department of Energy under contract DE-AC04-94SL85000 and by the Office of Science Graduate Student Research (SCGSR) program under Contract Number DE-AC05-06OR23100.

  20. Plant 115-kDa actin-filament bundling protein, P-115-ABP, is a homologue of plant villin and is widely distributed in cells.

    Science.gov (United States)

    Yokota, Etsuo; Vidali, Luis; Tominaga, Motoki; Tahara, Hiroshi; Orii, Hidefumi; Morizane, Yosuke; Hepler, Peter K; Shimmen, Teruo

    2003-10-01

    In many cases, actin filaments are arranged into bundles and serve as tracks for cytoplasmic streaming in plant cells. We have isolated an actin-filament bundling protein, which is composed of 115-kDa polypeptide (P-115-ABP), from the germinating pollen of lily, Lilium longiflorum [Nakayasu et al. (1998) BIOCHEM: Biophys. Res. Commun. 249: 61]. P-115-ABP shared similar antigenicity with a plant 135-kDa actin-filament bundling protein (P-135-ABP), a plant homologue of villin. A full-length cDNA clone (ABP115; accession no. AB097407) was isolated from an expression cDNA library of lily pollen by immuno-screening using antisera against P-115-ABP and P-135-ABP. The amino acid sequence of P-115-ABP deduced from this clone showed high homology with those of P-135-ABP and four villin isoforms of Arabidopsis thaliana (AtVLN1, AtVLN2, AtVLN3 and AtVLN4), especially AtVLN4, indicating that P-115-ABP can also be classified as a plant villin. The P-115-ABP isolated biochemically from the germinating lily pollen was able to arrange F-actin filaments with uniform polarity into bundles and this bundling activity was suppressed by Ca2+-calmodulin (CaM), similar to the actin-filament bundling properties of P-135-ABP. The P-115-ABP type of plant villin was widely distributed in plant cells, from algae to land plants. In root hair cells of Hydrocharis dubia, this type of plant villin was co-localized with actin-filament bundles in the transvacuolar strands and the sub-cortical regions. Microinjection of the antiserum against P-115-ABP into living root hair cells caused the disappearance of transvaculor strands and alteration of the route of cytoplasmic streaming. In internodal cells of Chara corallina in which the P-135-ABP type of plant villin is lacking, the P-115-ABP type showed co-localization with actin-filament cables anchored on the intracellular surface of chloroplasts. These results indicated that plant villins are widely distributed and involved in the organization of actin

  1. Sheath insulator final test report, TFE Verification Program

    International Nuclear Information System (INIS)

    1994-07-01

    The sheath insulator in a thermionic cell has two functions. First, the sheath insulator must electrically isolate the collector form the outer containment sheath tube that is in contact with the reactor liquid metal coolant. Second, The sheath insulator must provide for high uniform thermal conductance between the collector and the reactor coolant to remove away waste heat. The goals of the sheath insulator test program were to demonstrate that suitable ceramic materials and fabrication processes were available, and to validate the performance of the sheath insulator for TFE-VP requirements. This report discusses the objectives of the test program, fabrication development, ex-reactor test program, in-reactor test program, and the insulator seal specifications

  2. Sheath insulator final test report, TFE Verification Program

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

    The sheath insulator in a thermionic cell has two functions. First, the sheath insulator must electrically isolate the collector form the outer containment sheath tube that is in contact with the reactor liquid metal coolant. Second, The sheath insulator must provide for high uniform thermal conductance between the collector and the reactor coolant to remove away waste heat. The goals of the sheath insulator test program were to demonstrate that suitable ceramic materials and fabrication processes were available, and to validate the performance of the sheath insulator for TFE-VP requirements. This report discusses the objectives of the test program, fabrication development, ex-reactor test program, in-reactor test program, and the insulator seal specifications.

  3. Sheath heating in low-pressure capacitive radio frequency discharges

    International Nuclear Information System (INIS)

    Wood, B.P.

    1991-01-01

    Capacitively coupled, parallel plate, r.f. discharges are commonly used for materials processing. The electrons in such a discharge gain and lose energy by reflection from the oscillating sheaths which form at the electrodes. Previous models of the electron heating by this mechanism have assumed that the sheath motion is slow compared to the electron thermal velocity, so that the electron energy change from each reflection is small. Here, the heating rate, density, and sheath width relations are derived analytically in the limit of very fast sheath motion. Numerical results are presented spanning the slow and fast limits. Results from particle-in-cell simulations show that in the large-energy-change regime, an electron beam is produced on each sheath expansion. At low pressure, this beam can traverse the plasma and interact with the sheath at the opposite electrode, producing a beam energy and density dependence on the length of the discharge. The beam produces a time and space varying warm tail on the electron energy distribution. Two revised heating models are derived, assuming power-law and two-temperature electron energy distributions, with temporal variation in electron temperature. These revised models yield new predictions for the variation of the power, density, and sheath thickness with applied r.f. voltage. These predictions are compared with simulation results and laboratory experiment. The electron sheath motion is investigated experimentally by observing the signal on a floating probe in the sheath region. This is compared to the signal product by a non-linear circuit model which accounts for the perturbation of the sheath potential by the probe and includes various forms of sheath motion. The experimental observations are consistent with the analytical predictions. Experimental observations of plasma-sheath resonance oscillations are presented which agree with analytical predictions

  4. Reexcision Perineural Invasion and Epithelial Sheath Neuroma Possibly on a Spectrum of Postinjury Reactive Hyperplasia Mediated by IL-6.

    Science.gov (United States)

    Wang, James Y; Nuovo, Gerard; Kline, Mitchell; Magro, Cynthia M

    2017-01-01

    Epithelial sheath neuroma is a rarely recognized but established entity in the medical literature. First described in 2000 by Requena et al, there have only been 7 published cases to date, mostly in female patients and presenting as symptomatic solitary lesions on the back without a known history of trauma. In 2006, Beer et al described and reviewed a dozen cases in which epithelial sheath neuroma-like features were seen in the advent of a surgical procedure, which was termed "re-excision perineural invasion" and attributed to possible eccrine duct implantation during surgery. Our case is a 66-year-old male patient who underwent an excision of a melanocytic neoplasm in which a reactive epithelial sheath neuroma was incidentally discovered in the excision specimen, adjacent to the biopsy site cicatrix. Histologically, there was benign cutaneous nerve hyperplasia with a proliferation of squamous epithelium in intimate apposition to the nerve bundles in the superficial dermis. We postulate that the process active in the formation of re-excision perineural invasion is the same as in epithelial sheath neuroma and that minor trauma not appreciable on histologic examination is responsible in the latter entity. We performed IL-6 staining and documented that IL-6 was upregulated at the interface of the nerve and reactive epithelium, but was absent in nerves distant from the site of surgery, suggesting that IL-6 may be essential to the lesion's development. The recognition of reactive epithelial sheath neuroma including the subcategory of re-excision perineural invasion is crucial for the dermatopathologist to prevent mislabeling this reactive entity as a perineural squamous cell carcinoma, which has clinical consequences for the patient such as wider re-excision and radiation treatment. Additionally, we have identified a potential pathophysiologic basis for this lesion.

  5. CFD method research on characteristics cells in rod bundle fuel assembly

    International Nuclear Information System (INIS)

    Chen Jie; Chen Bingyan; Zhang Hong

    2011-01-01

    Two characteristic cells are in AFA-3G fuel assembly, that is typical cell and control rod guide cell. And there are some rules on the arrangement of mixing vanes. For the two characteristic cells, mixing capability is evaluated axially from the point of the first and second kind of sub-channel with CFD method. Mass mixing and heat mixing are interaction but different with each other. Although the mass mixing in the first kind of sub-channel is stronger, the thermal capability of the two is to some tune from the point of heat transfer. In the experiment research on thermal-hydraulic performance of AFA-3G fuel assembly, the arrangements of mixing vanes should refer to the two spacer grids of characteristic cells. (authors)

  6. Nonabelian bundle 2-gerbes

    OpenAIRE

    Jurco, Branislav

    2009-01-01

    We define 2-crossed module bundle 2-gerbes related to general Lie 2-crossed modules and discuss their properties. A 2-crossed module bundle 2-gerbe over a manifold is defined in terms of a so called 2-crossed module bundle gerbe, which is a crossed module bundle gerbe equipped with an extra sructure. It is shown that string structures can be described and classified using 2-crossed module bundle 2-gerbes.

  7. Gating energies and forces of the mammalian hair cell transducer channel and related hair bundle mechanics

    NARCIS (Netherlands)

    van Netten, SM; Kros, CJ

    2000-01-01

    We quantified the molecular energies and forces involved in opening and closing of mechanoelectrical transducer channels in hair cells using a novel generally applicable method. It relies on a thermodynamic description of the free energy of an ion channel in terms of its open probability. The

  8. Strategic Aspects of Bundling

    International Nuclear Information System (INIS)

    Podesta, Marion

    2008-01-01

    The increase of bundle supply has become widespread in several sectors (for instance in telecommunications and energy fields). This paper review relates strategic aspects of bundling. The main purpose of this paper is to analyze profitability of bundling strategies according to the degree of competition and the characteristics of goods. Moreover, bundling can be used as price discrimination tool, screening device or entry barriers. In monopoly case bundling strategy is efficient to sort consumers in different categories in order to capture a maximum of surplus. However, when competition increases, the profitability on bundling strategies depends on correlation of consumers' reservations values. (author)

  9. Signal detection by active, noisy hair bundles

    Science.gov (United States)

    O'Maoiléidigh, Dáibhid; Salvi, Joshua D.; Hudspeth, A. J.

    2018-05-01

    Vertebrate ears employ hair bundles to transduce mechanical movements into electrical signals, but their performance is limited by noise. Hair bundles are substantially more sensitive to periodic stimulation when they are mechanically active, however, than when they are passive. We developed a model of active hair-bundle mechanics that predicts the conditions under which a bundle is most sensitive to periodic stimulation. The model relies only on the existence of mechanotransduction channels and an active adaptation mechanism that recloses the channels. For a frequency-detuned stimulus, a noisy hair bundle's phase-locked response and degree of entrainment as well as its detection bandwidth are maximized when the bundle exhibits low-amplitude spontaneous oscillations. The phase-locked response and entrainment of a bundle are predicted to peak as functions of the noise level. We confirmed several of these predictions experimentally by periodically forcing hair bundles held near the onset of self-oscillation. A hair bundle's active process amplifies the stimulus preferentially over the noise, allowing the bundle to detect periodic forces less than 1 pN in amplitude. Moreover, the addition of noise can improve a bundle's ability to detect the stimulus. Although, mechanical activity has not yet been observed in mammalian hair bundles, a related model predicts that active but quiescent bundles can oscillate spontaneously when they are loaded by a sufficiently massive object such as the tectorial membrane. Overall, this work indicates that auditory systems rely on active elements, composed of hair cells and their mechanical environment, that operate on the brink of self-oscillation.

  10. Sheath impedance effects in very high frequency plasma experiments

    International Nuclear Information System (INIS)

    Schwarzenbach, W.; Howling, A.A.; Fivaz, M.; Brunner, S.; Hollenstein, C.

    1995-05-01

    The frequency dependence (13.56 MHz to 70 MHz) of the ion energy distribution at the ground electrode was measured by mass spectrometry in a symmetrical capacitive argon discharge. Reduced sheath impedance at Very High Frequency allows high levels of plasma power and substrate ion flux whilst maintaining low levels of ion energy and electrode voltage. The lower limit of ion bombardment energy is fixed by the sheath floating potential at high frequency, in contrast to low frequencies where only the rf voltage amplitude is determinant. The capacitive sheaths are thinner at high frequencies which accentuates the high frequency reduction in sheath impedance. It is argued that the frequency dependence of sheath impedance is responsible for the principal characteristics of Very High Frequency plasmas. The measurements are summarised by simple physical descriptions and compared with a Particle-In-Cell simulation. (author) figs., tabs., refs

  11. Sheath structure transition controlled by secondary electron emission

    Science.gov (United States)

    Schweigert, I. V.; Langendorf, S. J.; Walker, M. L. R.; Keidar, M.

    2015-04-01

    In particle-in-cell Monte Carlo collision (PIC MCC) simulations and in an experiment we study sheath formation over an emissive floating Al2O3 plate in a direct current discharge plasma at argon gas pressure 10-4 Torr. The discharge glow is maintained by the beam electrons emitted from a negatively biased hot cathode. We observe three types of sheaths near the floating emissive plate and the transition between them is driven by changing the negative bias. The Debye sheath appears at lower voltages, when secondary electron emission is negligible. With increasing applied voltage, secondary electron emission switches on and a first transition to a new sheath type, beam electron emission (BEE), takes place. For the first time we find this specific regime of sheath operation near the floating emissive surface. In this regime, the potential drop over the plate sheath is about four times larger than the temperature of plasma electrons. The virtual cathode appears near the emissive plate and its modification helps to maintain the BEE regime within some voltage range. Further increase of the applied voltage U initiates the second smooth transition to the plasma electron emission sheath regime and the ratio Δφs/Te tends to unity with increasing U. The oscillatory behavior of the emissive sheath is analyzed in PIC MCC simulations. A plasmoid of slow electrons is formed near the plate and transported to the bulk plasma periodically with a frequency of about 25 kHz.

  12. Bundle Branch Block

    Science.gov (United States)

    ... known cause. Causes can include: Left bundle branch block Heart attacks (myocardial infarction) Thickened, stiffened or weakened ... myocarditis) High blood pressure (hypertension) Right bundle branch block A heart abnormality that's present at birth (congenital) — ...

  13. Abiotic Deposition of Fe Complexes onto Leptothrix Sheaths

    Science.gov (United States)

    Kunoh, Tatsuki; Hashimoto, Hideki; McFarlane, Ian R.; Hayashi, Naoaki; Suzuki, Tomoko; Taketa, Eisuke; Tamura, Katsunori; Takano, Mikio; El-Naggar, Mohamed Y.; Kunoh, Hitoshi; Takada, Jun

    2016-01-01

    Bacteria classified in species of the genus Leptothrix produce extracellular, microtubular, Fe-encrusted sheaths. The encrustation has been previously linked to bacterial Fe oxidases, which oxidize Fe(II) to Fe(III) and/or active groups of bacterial exopolymers within sheaths to attract and bind aqueous-phase inorganics. When L. cholodnii SP-6 cells were cultured in media amended with high Fe(II) concentrations, Fe(III) precipitates visibly formed immediately after addition of Fe(II) to the medium, suggesting prompt abiotic oxidation of Fe(II) to Fe(III). Intriguingly, these precipitates were deposited onto the sheath surface of bacterial cells as the population was actively growing. When Fe(III) was added to the medium, similar precipitates formed in the medium first and were abiotically deposited onto the sheath surfaces. The precipitates in the Fe(II) medium were composed of assemblies of globular, amorphous particles (ca. 50 nm diameter), while those in the Fe(III) medium were composed of large, aggregated particles (≥3 µm diameter) with a similar amorphous structure. These precipitates also adhered to cell-free sheaths. We thus concluded that direct abiotic deposition of Fe complexes onto the sheath surface occurs independently of cellular activity in liquid media containing Fe salts, although it remains unclear how this deposition is associated with the previously proposed mechanisms (oxidation enzyme- and/or active group of organic components-involved) of Fe encrustation of the Leptothrix sheaths. PMID:27271677

  14. Abiotic Deposition of Fe Complexes onto Leptothrix Sheaths

    Directory of Open Access Journals (Sweden)

    Tatsuki Kunoh

    2016-06-01

    Full Text Available Bacteria classified in species of the genus Leptothrix produce extracellular, microtubular, Fe-encrusted sheaths. The encrustation has been previously linked to bacterial Fe oxidases, which oxidize Fe(II to Fe(III and/or active groups of bacterial exopolymers within sheaths to attract and bind aqueous-phase inorganics. When L. cholodnii SP-6 cells were cultured in media amended with high Fe(II concentrations, Fe(III precipitates visibly formed immediately after addition of Fe(II to the medium, suggesting prompt abiotic oxidation of Fe(II to Fe(III. Intriguingly, these precipitates were deposited onto the sheath surface of bacterial cells as the population was actively growing. When Fe(III was added to the medium, similar precipitates formed in the medium first and were abiotically deposited onto the sheath surfaces. The precipitates in the Fe(II medium were composed of assemblies of globular, amorphous particles (ca. 50 nm diameter, while those in the Fe(III medium were composed of large, aggregated particles (≥3 µm diameter with a similar amorphous structure. These precipitates also adhered to cell-free sheaths. We thus concluded that direct abiotic deposition of Fe complexes onto the sheath surface occurs independently of cellular activity in liquid media containing Fe salts, although it remains unclear how this deposition is associated with the previously proposed mechanisms (oxidation enzyme- and/or active group of organic components-involved of Fe encrustation of the Leptothrix sheaths.

  15. The Tubular Sheaths Encasing Methanosaeta thermophila Filaments Are Functional Amyloids.

    Science.gov (United States)

    Dueholm, Morten S; Larsen, Poul; Finster, Kai; Stenvang, Marcel R; Christiansen, Gunna; Vad, Brian S; Bøggild, Andreas; Otzen, Daniel E; Nielsen, Per Halkjær

    2015-08-14

    Archaea are renowned for their ability to thrive in extreme environments, although they can be found in virtually all habitats. Their adaptive success is linked to their unique cell envelopes that are extremely resistant to chemical and thermal denaturation and that resist proteolysis by common proteases. Here we employ amyloid-specific conformation antibodies and biophysical techniques to show that the extracellular cell wall sheaths encasing the methanogenic archaea Methanosaeta thermophila PT are functional amyloids. Depolymerization of sheaths and subsequent MS/MS analyses revealed that the sheaths are composed of a single major sheath protein (MspA). The amyloidogenic nature of MspA was confirmed by in vitro amyloid formation of recombinant MspA under a wide range of environmental conditions. This is the first report of a functional amyloid from the archaeal domain of life. The amyloid nature explains the extreme resistance of the sheath, the elastic properties that allow diffusible substrates to penetrate through expandable hoop boundaries, and how the sheaths are able to split and elongate outside the cell. The archaeal sheath amyloids do not share homology with any of the currently known functional amyloids and clearly represent a new function of the amyloid protein fold. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. In vivo engineering of a functional tendon sheath in a hen model.

    Science.gov (United States)

    Xu, Liang; Cao, Dejun; Liu, Wei; Zhou, Guangdong; Zhang, Wen Jie; Cao, Yilin

    2010-05-01

    Repair of injured tendon sheath remains a major challenge and this study explored the possibility of in vivo reconstruction of a tendon sheath with tendon sheath derived cells and polyglycolic acid (PGA) fibers in a Leghorn hen model. Total 55 Leghorn hens with a 1cm tendon sheath defect created in the left middle toe of each animal were randomly assigned into: (1) experimental group (n=19) that received a cell-PGA construct; (2) scaffold control group (n=18) that received a cell-free PGA scaffold; (3) blank control group (n=18) with the defect untreated. Tendon sheath cells were isolated, in vitro expanded, and seeded onto PGA scaffolds. After in vitro culture for 7 days, the constructs were in vivo implanted to repair the sheath defects. Alcian blue staining confirmed the ability of cultured cells to produce specific matrices containing acidic carboxyl mucopolysaccharide (mainly hyaluronic acid). In addition, the engineered sheath formed a relatively mature structure at 12 weeks post-surgery, which was similar to that of native counterpart, including a smooth inner surface, a well-developed sheath histological structure with a clear space between the tendon and the engineered sheath. More importantly, Work of Flexion assay revealed that the tendons needed less power consumption to glide inside the engineered sheath when compared to the tendons which were surrounded by scar-repaired tissues, indicating that the engineered sheaths had gained the function to a certain extent of preventing tendon adhesion. Taken together, these results suggest that tendon sheaths that are functionally and structurally similar to native sheaths are possible to be engineered in vivo using tendon sheath cells and PGA scaffolds. Copyright 2010 Elsevier Ltd. All rights reserved.

  17. Gene Expression Profiling of the Intact Dermal Sheath Cup of Human Hair Follicles.

    Science.gov (United States)

    Niiyama, Shiro; Ishimatsu-Tsuji, Yumiko; Nakazawa, Yosuke; Yoshida, Yuzo; Soma, Tsutomu; Ideta, Ritsuro; Mukai, Hideki; Kishimoto, Jiro

    2018-04-24

    Cells that constitute the dermal papillae of hair follicles might be derived from the dermal sheath, the peribulbar component of which is the dermal sheath cup. The dermal sheath cup is thought to include the progenitor cells of the dermal papillae and possesses hair inductive potential; however, it has not yet been well characterized. This study investigated the gene expression profile of the intact dermal sheath cup, and identified dermal sheath cup signature genes, including extracellular matrix components and BMP-binding molecules, as well as TGF-b1 as an upstream regulator. Among these, GREM2, a member of the BMP antagonists, was found by in situ hybridization to be highly specific to the dermal sheath cup, implying that GREM2 is a key molecule contributing to maintenance of the properties of the dermal sheath cup.

  18. Electric fields in the sheath formed in a 300 mm, dual frequency capacitive argon discharge

    International Nuclear Information System (INIS)

    Barnat, E V; Miller, P A; Hebner, G A; Paterson, A M; Panagopoulos, T; Hammond, E; Holland, J

    2007-01-01

    The spatial structure and temporal evolution of the electric fields in a sheath formed in a dual frequency, 300 mm capacitive argon discharge are measured as functions of relative mixing between a low frequency current and a high frequency current. It is found that the overall structure of the sheath (potential across the sheath and the thickness of the sheath) are dominated by the lower frequency component while (smaller) oscillations in these quantities are dictated by the higher frequency component. Comparisons of the measured spatial and temporal profiles are made for Lieberman's and Robiche et al sheath model and with a particle in a cell calculation

  19. Stability of the plasma sheath

    International Nuclear Information System (INIS)

    Franklin, R.N.

    1979-12-01

    The stability of a collisionless sheath joined to a plasma in the presence of secondary emission of electrons from the sheath boundary is examined in the fluid approximation. Instability is unlikely to occur under floating conditions but if significant currents flow corresponding to increased wall-plasma potentials the system can go unstable. (author)

  20. CANDU fuel bundle deformation modelling with COMSOL multiphysics

    International Nuclear Information System (INIS)

    Bell, J.S.; Lewis, B.J.

    2012-01-01

    Highlights: ► The deformation behaviour of a CANDU fuel bundle was modelled. ► The model has been developed on a commercial finite-element platform. ► Pellet/sheath interaction and end-plate restraint effects were considered. ► The model was benchmarked against the BOW code and a variable-load experiment. - Abstract: A model to describe deformation behaviour of a CANDU 37-element bundle has been developed under the COMSOL Multiphysics finite-element platform. Beam elements were applied to the fuel elements (composed of fuel sheaths and pellets) and endplates in order to calculate the bowing behaviour of the fuel elements. This model is important to help assess bundle-deformation phenomena, which may lead to more restrictive coolant flow through the sub-channels of the horizontally oriented bundle. The bundle model was compared to the BOW code for the occurrence of a dry-out patch, and benchmarked against an out-reactor experiment with a variable load on an outer fuel element.

  1. Synovial sarcoma mimicking benign peripheral nerve sheath tumor

    Energy Technology Data Exchange (ETDEWEB)

    Larque, Ana B.; Nielsen, G.P.; Chebib, Ivan [Massachusetts General Hospital and Harvard Medical School, Department of Pathology, Boston, MA (United States); Bredella, Miriam A. [Massachusetts General Hospital and Harvard Medical School, Department of Radiology, Boston, MA (United States)

    2017-11-15

    To assess the radiographic and clinicopathologic features of synovial sarcoma of the nerve that were clinically or radiologically interpreted as benign peripheral nerve sheath tumor. Five patients with synovial sarcoma arising from the peripheral nerve and interpreted clinically and radiologically as peripheral nerve sheath tumors were identified. Clinicopathologic and imaging features were evaluated. There were three females and two males, ranging in age from 28 to 50 (mean 35.8) years. Most patients (4/5) complained of a mass, discomfort or pain. MR images demonstrated a heterogeneous, enhancing, soft tissue mass contiguous with the neurovascular bundle. On histologic examination, most tumors were monophasic synovial sarcoma (4/5). At the time of surgery, all tumors were noted to arise along or within a peripheral nerve. All patients were alive with no evidence of disease with median follow-up of 44 (range 32-237) months. For comparison, approximately 775 benign peripheral nerve sheath tumors of the extremities were identified during the same time period. Primary synovial sarcoma of the nerve can mimic peripheral nerve sheath tumors clinically and on imaging and should be included in the differential diagnosis for tumors arising from peripheral nerves. (orig.)

  2. The actin-binding proteins eps8 and gelsolin have complementary roles in regulating the growth and stability of mechanosensory hair bundles of mammalian cochlear outer hair cells.

    Directory of Open Access Journals (Sweden)

    Jennifer Olt

    Full Text Available Sound transduction depends upon mechanosensitive channels localized on the hair-like bundles that project from the apical surface of cochlear hair cells. Hair bundles show a stair-case structure composed of rows of stereocilia, and each stereocilium contains a core of tightly-packed and uniformly-polarized actin filaments. The growth and maintenance of the stereociliary actin core are dynamically regulated. Recently, it was shown that the actin-binding protein gelsolin is expressed in the stereocilia of outer hair cells (OHCs and in its absence they become long and straggly. Gelsolin is part of a whirlin scaffolding protein complex at the stereocilia tip, which has been shown to interact with other actin regulatory molecules such as Eps8. Here we investigated the physiological effects associated with the absence of gelsolin and its possible overlapping role with Eps8. We found that, in contrast to Eps8, gelsolin does not affect mechanoelectrical transduction during immature stages of development. Moreover, OHCs from gelsolin knockout mice were able to mature into fully functional sensory receptors as judged by the normal resting membrane potential and basolateral membrane currents. Mechanoelectrical transducer current in gelsolin-Eps8 double knockout mice showed a profile similar to that observed in the single mutants for Eps8. We propose that gelsolin has a non-overlapping role with Eps8. While Eps8 is mainly involved in the initial growth of stereocilia in both inner hair cells (IHCs and OHCs, gelsolin is required for the maintenance of mature hair bundles of low-frequency OHCs after the onset of hearing.

  3. Myosin VIIa, harmonin and cadherin 23, three Usher I gene products that cooperate to shape the sensory hair cell bundle

    Science.gov (United States)

    Boëda, Batiste; El-Amraoui, Aziz; Bahloul, Amel; Goodyear, Richard; Daviet, Laurent; Blanchard, Stéphane; Perfettini, Isabelle; Fath, Karl R.; Shorte, Spencer; Reiners, Jan; Houdusse, Anne; Legrain, Pierre; Wolfrum, Uwe; Richardson, Guy; Petit, Christine

    2002-01-01

    Deaf-blindness in three distinct genetic forms of Usher type I syndrome (USH1) is caused by defects in myosin VIIa, harmonin and cadherin 23. Despite being critical for hearing, the functions of these proteins in the inner ear remain elusive. Here we show that harmonin, a PDZ domain-containing protein, and cadherin 23 are both present in the growing stereocilia and that they bind to each other. Moreover, we demonstrate that harmonin b is an F-actin-bundling protein, which is thus likely to anchor cadherin 23 to the stereocilia microfilaments, thereby identifying a novel anchorage mode of the cadherins to the actin cytoskeleton. Moreover, harmonin b interacts directly with myosin VIIa, and is absent from the disorganized hair bundles of myosin VIIa mutant mice, suggesting that myosin VIIa conveys harmonin b along the actin core of the developing stereocilia. We propose that the shaping of the hair bundle relies on a functional unit composed of myosin VIIa, harmonin b and cadherin 23 that is essential to ensure the cohesion of the stereocilia. PMID:12485990

  4. Polycation induced actin bundles

    OpenAIRE

    Muhlrad, Andras; Grintsevich, Elena E.; Reisler, Emil

    2011-01-01

    Three polycations, polylysine, the polyamine spermine and the polycationic protein lysozyme were used to study the formation, structure, ionic strength sensitivity and dissociation of polycation-induced actin bundles. Bundles form fast, simultaneously with the polymerization of MgATP-G-actins, upon addition of polycations to solutions of actins at low ionic strength conditions. This indicates that nuclei and/or nascent filaments bundle due to attractive, electrostatic effect of polycations an...

  5. Polycation induced actin bundles.

    Science.gov (United States)

    Muhlrad, Andras; Grintsevich, Elena E; Reisler, Emil

    2011-04-01

    Three polycations, polylysine, the polyamine spermine and the polycationic protein lysozyme were used to study the formation, structure, ionic strength sensitivity and dissociation of polycation-induced actin bundles. Bundles form fast, simultaneously with the polymerization of MgATP-G-actins, upon the addition of polycations to solutions of actins at low ionic strength conditions. This indicates that nuclei and/or nascent filaments bundle due to attractive, electrostatic effect of polycations and the neutralization of repulsive interactions of negative charges on actin. The attractive forces between the filaments are strong, as shown by the low (in nanomolar range) critical concentration of their bundling at low ionic strength. These bundles are sensitive to ionic strength and disassemble partially in 100 mM NaCl, but both the dissociation and ionic strength sensitivity can be countered by higher polycation concentrations. Cys374 residues of actin monomers residing on neighboring filaments in the bundles can be cross-linked by the short span (5.4Å) MTS-1 (1,1-methanedyl bismethanethiosulfonate) cross-linker, which indicates a tight packing of filaments in the bundles. The interfilament cross-links, which connect monomers located on oppositely oriented filaments, prevent disassembly of bundles at high ionic strength. Cofilin and the polysaccharide polyanion heparin disassemble lysozyme induced actin bundles more effectively than the polylysine-induced bundles. The actin-lysozyme bundles are pathologically significant as both proteins are found in the pulmonary airways of cystic fibrosis patients. Their bundles contribute to the formation of viscous mucus, which is the main cause of breathing difficulties and eventual death in this disorder. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Stability of the Tonks–Langmuir discharge pre-sheath

    Energy Technology Data Exchange (ETDEWEB)

    Tskhakaya, D. D. [Fusion@ÖAW, Institute of Applied Physics, TU Wien, Wiedner Hauptstraße 8-10, 1040 Vienna (Austria); Kos, L. [LECAD Laboratory, Faculty of Mechanical Engineering, University of Ljubljana, SI-1000 Ljubljana (Slovenia); Tskhakaya, D. [Fusion@ÖAW, Institute of Applied Physics, TU Wien, Wiedner Hauptstraße 8-10, 1040 Vienna (Austria); Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck (Austria)

    2016-03-15

    The article formulates the stability problem of the plasma sheath in the Tonks–Langmuir discharge. Using the kinetic description of the ion gas, i.e., the stability of the potential shape in the quasi-neutral pre-sheath regarding the high and low frequency, the perturbations are investigated. The electrons are assumed to be Maxwell–Boltzmann distributed. Regarding high-frequency perturbations, the pre-sheath is shown to be stable. The stability problem regarding low-frequency perturbations can be reduced to an analysis of the “diffusion like” equation, which results in the instability of the potential distribution in the pre-sheath. By means of the Particle in Cell simulations, also the nonlinear stage of low frequency oscillations is investigated. Comparing the figure obtained with the figure for linear stage, one can find obvious similarity in the spatial-temporal behavior of the potential.

  7. The electrostatic cylindrical sheath in a plasma

    International Nuclear Information System (INIS)

    Wang Chunhua; Sun Xiaoxia; Bai Dongxue

    2004-01-01

    The electrostatic sheath with a cylindrical geometry in an ion-electron plasma is investigated. Assuming a Boltzmann response to electrons and cold ions with bulk flow, it is shown that the radius of the cylindrical geometry do not affect the sheath potential significantly. The authors also found that the sheath potential profile is steeper in the cylindrical sheath compared to the slab sheath. The distinct feature of the cylindrical sheath is that the ion density distribution is not monotonous. The sheath region can be divided into three regions, two ascendant regions and one descendant region. (author)

  8. Anode sheath in Hall thrusters

    International Nuclear Information System (INIS)

    Dorf, L.; Semenov, V.; Raitses, Y.

    2003-01-01

    A set of hydrodynamic equations is used to describe quasineutral plasma in ionization and acceleration regions of a Hall thruster. The electron distribution function and Poisson equation are invoked for description of a near-anode region. Numerical solutions suggest that steady-state operation of a Hall thruster can be achieved at different anode sheath regimes. It is shown that the anode sheath depends on the thruster operating conditions, namely the discharge voltage and the mass flow rate

  9. Principal noncommutative torus bundles

    DEFF Research Database (Denmark)

    Echterhoff, Siegfried; Nest, Ryszard; Oyono-Oyono, Herve

    2008-01-01

    of bivariant K-theory (denoted RKK-theory) due to Kasparov. Using earlier results of Echterhoff and Williams, we shall give a complete classification of principal non-commutative torus bundles up to equivariant Morita equivalence. We then study these bundles as topological fibrations (forgetting the group...

  10. Effects of emitted electron temperature on the plasma sheath

    International Nuclear Information System (INIS)

    Sheehan, J. P.; Kaganovich, I. D.; Wang, H.; Raitses, Y.; Sydorenko, D.; Hershkowitz, N.

    2014-01-01

    It has long been known that electron emission from a surface significantly affects the sheath surrounding that surface. Typical fluid theory of a planar sheath with emitted electrons assumes that the plasma electrons follow the Boltzmann relation and the emitted electrons are emitted with zero energy and predicts a potential drop of 1.03T e /e across the sheath in the floating condition. By considering the modified velocity distribution function caused by plasma electrons lost to the wall and the half-Maxwellian distribution of the emitted electrons, it is shown that ratio of plasma electron temperature to emitted electron temperature significantly affects the sheath potential when the plasma electron temperature is within an order of magnitude of the emitted electron temperature. When the plasma electron temperature equals the emitted electron temperature the emissive sheath potential goes to zero. One dimensional particle-in-cell simulations corroborate the predictions made by this theory. The effects of the addition of a monoenergetic electron beam to the Maxwellian plasma electrons were explored, showing that the emissive sheath potential is close to the beam energy only when the emitted electron flux is less than the beam flux

  11. Simulations of rf-driven sheath formation in two dimensions

    International Nuclear Information System (INIS)

    Riyopoulos, S.; Grossmann, W.; Drobot, A.; Kress, M.

    1992-01-01

    The results from two-dimensional particle simulations of sheath formation around periodic metal arrays placed inside magnetized plasmas and driven by oscillating voltages are reported. The main goal is the modeling of the plasma interaction with the Faraday bars surrounding the antennas during ion cyclotron tokamak heating. The study of the time-averaged potentials shows that the two-dimensional sheath structure depends on both the sheath length-to-thickness ratio and the inclination of the magnetic lines. The equipotential surfaces form closed, nested cells between adjacent bars. When the magnetic lines are nearly perpendicular to the potential gradients, the ion motion is dominated by the ExB drift, and ion streamlines form vortices around the equipotentials. At larger inclinations of the magnetic lines, the flow decouples from the equipotentials and ion transport is mainly along the potential gradients. The critical angle for the transition from vortex circulation to field aligned flow is computed. The effects of the cross-field ion transport on the sheath properties are discussed. It is shown that the sheath length and the magnetic line inclination affect the sheath scaling in the two-dimensional case. The one-dimensional theory results are recovered in the limit of high length-to-thickness ratio and large inclination of the magnetic lines

  12. Photovoltaic building sheathing element with anti-slide features

    Science.gov (United States)

    Keenihan, James R.; Langmaid, Joseph A.; Lopez, Leonardo C.

    2015-09-08

    The present invention is premised` upon an assembly that includes at least a photovoltaic building sheathing element capable of being affixed on a building structure, the photovoltaic building sheathing element. The element including a photovoltaic cell assembly, a body portion attached to one or more portions of the photovoltaic cell assembly; and at feast a first and a second connector assembly capable of directly or indirectly electrically connecting the photovoltaic cell assembly to one or more adjoining devices; wherein the body portion includes one or more geometric features adapted to engage a vertically adjoining device before installation.

  13. Filament bundle location influence on coupling losses in superconducting composites

    International Nuclear Information System (INIS)

    Ito, Daisuke; Koizumi, Misao; Hamajima, Takataro; Nakane, Fumoto.

    1983-01-01

    The ac losses in multifilamentary superconducting composites with different superconducting filament bundle positions have been measured using the magnetization method in order to reveal the relation between filament bundle position and coupling losses. Loss components depending on dB/dt in a mixed matrix superconducting composite, whose filament bundle is located in a central region surrounded by an outer stabilizing copper sheath, has been compared with another superconducting composite whose stabilizing copper is located in a central region surrounded by an outer filament bundle. In both conductors, key parameters, such as filament twistpitch, wire diameter and amount of copper stabilizer, were almost the same. Applied magnetic field is 2 Tesla with 0.05-2 Tesla/sec field change rate. Experimental results indicate that coupling losses between filaments in the composite with the filament bundle located in the central region is smaller than the composite with the filament bundle located in the outer region. A similar conclusion was reached theoretically by B. Truck. Coupling loss values obtained by the experiment show good agreement with calculated values with the equations proposed by B. Truck. It is also pointed out that a copper stabilizer, divided by the CuNi barrier into small regions, like a honeycomb, causes anomalous increasing in the copper resistivity due to Ni diffusion during heat treatment. (author)

  14. Sheath waves, non collisional dampings

    International Nuclear Information System (INIS)

    Marec, Jean Lucien Ernest

    1974-01-01

    When a metallic conductor is inserted into an ionised gas, an area of electron depletion is formed between the conductor and the plasma: the ionic sheath. Moreover, if the conductor is excited by an electric field, this ionic sheath plays an important role with respect to microwave properties. In this research thesis, the author addresses the range of frequencies smaller than the plasma frequency, and reports the study of resonance phenomena. After a presentation of the problem through a bibliographical study, the author recalls general characteristics of sheath wave propagation and of sheath resonances, and discusses the validity of different hypotheses (for example and among others, electrostatic approximations, cold plasma). Then, the author more particularly addresses theoretical problems related to non collisional dampings: brief bibliographical study, detailed presentation and description of the theoretical model, damping calculation methods. The author then justifies the design and performance of an experiment, indicates measurement methods used to determine plasma characteristics as well as other magnitudes which allow the description of mechanisms of propagation and damping of sheath waves. Experimental results are finally presented with respect to various parameters. The author discusses to which extent the chosen theoretical model is satisfying [fr

  15. Self-consistent radial sheath

    International Nuclear Information System (INIS)

    Hazeltine, R.D.

    1988-12-01

    The boundary layer arising in the radial vicinity of a tokamak limiter is examined, with special reference to the TEXT tokamak. It is shown that sheath structure depends upon the self-consistent effects of ion guiding-center orbit modification, as well as the radial variation of E /times/ B-induced toroidal rotation. Reasonable agreement with experiment is obtained from an idealized model which, however simplified, preserves such self-consistent effects. It is argued that the radial sheath, which occurs whenever confining magnetic field-lines lie in the plasma boundary surface, is an object of some intrinsic interest. It differs from the more familiar axial sheath because magnetized charges respond very differently to parallel and perpendicular electric fields. 11 refs., 1 fig

  16. Vibration of fuel bundles

    International Nuclear Information System (INIS)

    Chen, S.S.

    1975-06-01

    Several mathematical models have been proposed for calculating fuel rod responses in axial flows based on a single rod consideration. The spacing between fuel rods in liquid metal fast breeder reactors is small; hence fuel rods will interact with one another due to fluid coupling. The objective of this paper is to study the coupled vibration of fuel bundles. To account for the fluid coupling, a computer code, AMASS, is developed to calculate added mass coefficients for a group of circular cylinders based on the potential flow theory. The equations of motion for rod bundles are then derived including hydrodynamic forces, drag forces, fluid pressure, gravity effect, axial tension, and damping. Based on the equations, a method of analysis is presented to study the free and forced vibrations of rod bundles. Finally, the method is applied to a typical LMFBR fuel bundle consisting of seven rods

  17. Intrapontine malignant nerve sheath tumor

    DEFF Research Database (Denmark)

    Kozić, Dusko; Nagulić, Mirjana; Samardzić, Miroslav

    2008-01-01

    . On pathological examination, the neoplasm appeared to be an intrapontine nerve sheath tumor originating most likely from the intrapontine segment of one of the cranial nerve fibres. The tumor showed exophytic growth, with consequent spread to adjacent subaracnoid space. MR spectroscopy revealed the presence......The primary source of malignant intracerebral nerve sheath tumors is still unclear We report the imaging and MR spectroscopic findings in a 39-year-old man with a very rare brain stem tumor MR examination revealed the presence of intraaxial brain stem tumor with a partial exophytic growth...

  18. Optic Nerve Sheath Mechanics in VIIP Syndrome

    Science.gov (United States)

    Raykin, Julia; Forte, Taylor E.; Wang, Roy; Feola, Andrew; Samuels, Brian; Myers, Jerry; Nelson, Emily; Gleason, Rudy; Ethier, C. Ross

    2016-01-01

    to the tissue; i.e., as the axial load is varied, the diameter of the dura mater remains constant. This cross-over in the pressure-diameter curves occurred in all optic nerve sheaths that were tested, and may correspond with in vivo ICP levels for pigs. These data suggest that diameter of the dura mater of the optic nerve remains nearly constant in vivo despite being stretched axially. This may be a homeostatic mechanism aimed at maintaining target stresses/strains on the cells in the dura mater, and deviations from these stresses may play an important role in optic nerve sheath remodeling. Future studies will involve subjecting the dura mater to varying pressures and axial tensions for extended periods of time, while monitoring changes in the biomechanical properties. The data can then be used to study the effects of changes in ICP on the remodeling of the dura mater.

  19. On the biogenesis of the myelin sheath : Cognate polarized trafficking pathways in oligodendrocytes

    NARCIS (Netherlands)

    de Vries, H; Hoekstra, D

    2000-01-01

    Oligodendrocytes, the myelinating cells of the central nervous system, are capable of transporting vast quantities of proteins and of lipids, In particular galactosphingolipids, to the myelin sheath. The sheath is continuous with the plasma membrane of the oligodendrocyte, but the composition of

  20. Plasma sheath criterion in thermal electronegative plasmas

    International Nuclear Information System (INIS)

    Ghomi, Hamid; Khoramabadi, Mansour; Ghorannevis, Mahmod; Shukla, Padma Kant

    2010-01-01

    The sheath formation criterion in electronegative plasma is examined. By using a multifluid model, it is shown that in a collisional sheath there will be upper as well as lower limits for the sheath velocity criterion. However, the parameters of the negative ions only affect the lower limit.

  1. Hertwig’s Epithelial Root Sheath Fate during Initial Cellular Cementogenesis in Rat Molars

    International Nuclear Information System (INIS)

    Yamamoto, Tsuneyuki; Yamada, Tamaki; Yamamoto, Tomomaya; Hasegawa, Tomoka; Hongo, Hiromi; Oda, Kimimitsu; Amizuka, Norio

    2015-01-01

    To elucidate the fate of the epithelial root sheath during initial cellular cementogenesis, we examined developing maxillary first molars of rats by immunohistochemistry for keratin, vimentin, and tissue non-specific alkaline phosphatase (TNALP) and by TdT-mediated dUTP nick end labeling (TUNEL). The advancing root end was divided into three sections, which follow three distinct stages of initial cellular cementogenesis: section 1, where the epithelial sheath is intact; section 2, where the epithelial sheath becomes fragmented; and section 3, where initial cellular cementogenesis begins. After fragmentation of the epithelial sheath, many keratin-positive epithelial sheath cells were embedded in the rapidly growing cellular cementum. A few unembedded epithelial cells located on the cementum surface. Dental follicle cells, precementoblasts, and cementoblasts showed immunoreactivity for vimentin and TNALP. In all three sections, there were virtually no cells possessing double immunoreactivity for vimentin-keratin or TNALP-keratin and only embedded epithelial cells showed TUNEL reactivity. Taken together, these findings suggest that: (1) epithelial sheath cells divide into two groups; one group is embedded in the cementum and thereafter dies by apoptosis, and the other survives on the cementum surface as epithelial cell rests of Malassez; and (2) epithelial sheath cells do not undergo epithelial-mesenchymal transition during initial cellular cementogenesis

  2. Ontogeny of the sheathing leaf base in maize (Zea mays).

    Science.gov (United States)

    Johnston, Robyn; Leiboff, Samuel; Scanlon, Michael J

    2015-01-01

    Leaves develop from the shoot apical meristem (SAM) via recruitment of leaf founder cells. Unlike eudicots, most monocot leaves display parallel venation and sheathing bases wherein the margins overlap the stem. Here we utilized computed tomography (CT) imaging, localization of PIN-FORMED1 (PIN1) auxin transport proteins, and in situ hybridization of leaf developmental transcripts to analyze the ontogeny of monocot leaf morphology in maize (Zea mays). CT imaging of whole-mounted shoot apices illustrates the plastochron-specific stages during initiation of the basal sheath margins from the tubular disc of insertion (DOI). PIN1 localizations identify basipetal auxin transport in the SAM L1 layer at the site of leaf initiation, a process that continues reiteratively during later recruitment of lateral leaf domains. Refinement of these auxin transport domains results in multiple, parallel provascular strands within the initiating primordium. By contrast, auxin is transported from the L2 toward the L1 at the developing margins of the leaf sheath. Transcripts involved in organ boundary formation and dorsiventral patterning accumulate within the DOI, preceding the outgrowth of the overlapping margins of the sheathing leaf base. We suggest a model wherein sheathing bases and parallel veins are both patterned via the extended recruitment of lateral maize leaf domains from the SAM. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  3. Fabrication of CANFLEX bundle kit for irradiation test in NRU

    International Nuclear Information System (INIS)

    Cho, Moon Sung; Kwon, Hyuk Il; Ji, Chul Goo; Chang, Ho Il; Sim, Ki Seob; Suk, Ho Chun.

    1997-10-01

    CANFLEX bundle kit was prepared at KAERI for the fabrication of complete bundle at AECL. Completed bundle will be used for irradiation test in NRU. Provisions in the 'Quality Assurance Manual for HWR Fuel Projects,' 'Manufacturing Plan' and 'Quality Verification, Inspection and Test Plan' were implemented as appropriately for the preparation of CANFLEX kit. A set of CANFLEX kit consist of 43 fuel sheath of two different sizes with spacers, bearing pads and buttons attached, 2 pieces of end plates and 86 pieces of end caps with two different sizes. All the documents utilized as references for the fabrication such as drawings, specifications, operating instructions, QC instructions and supplier's certificates are specified in this report. Especially, suppliers' certificates and inspection reports for the purchased material as well as KAERI's inspection report are integrated as attachments to this report. Attached to this report are supplier's certificates and KAERI inspection reports for the procured materials and KAERI QC inspection reports for tubes, pads, spacers, buttons, end caps, end plates and fuel sheath. (author). 37 refs

  4. Ion acceleration in the plasma source sheath

    International Nuclear Information System (INIS)

    Birdsall, C.K.

    1986-01-01

    This note is a calculation of the potential drop for a planar plasma source, across the source sheath, into a uniform plasma region defined by vector E = 0 and/or perhaps ∂ 2 PHI/∂ x 2 = 0. The calculation complements that of Bohm who obtained the potential drop at the other end of a plasma, at a planar collector sheath. The result is a relation between the source ion flux and the source sheath potential drop and the accompanying ion acceleration. This planar source sheath ion acceleration mechanism (or that from a distributed source) can provide the pre-collector-sheath ion acceleration as found necessary by Bohm. 3 refs

  5. Fibroma of the tendon sheath of the long head of the biceps tendon

    International Nuclear Information System (INIS)

    Maeseneer, Michel de; Shahabpour, Maryam; Isacker, Tom van; Lenchik, Leon; Caillie, Marie-Astrid van

    2014-01-01

    Fibroma of the tendon sheath is a benign tumor that is less common than giant cell tumor of the tendon sheath. Both tumors may present as a painless, slowly enlarging mass. Radiological findings may be similar for both tumors. Histologically, fibroma of the tendon sheath lacks the hemosiderin-laden macrophages that are typical for giant cell tumor of the tendon sheath. We report on a 49-year-old woman with fibroma of the tendon sheath of the long head of the biceps tendon. In our case, on MR images, we observed band-like hypointense areas centrally in the tumor, mild patchy contrast enhancement, and most importantly, no decrease of signal intensity on gradient echo images. These characteristics reflected histological findings. (orig.)

  6. Dissociation and Re-Aggregation of Multicell-Ensheathed Fragments Responsible for Rapid Production of Massive Clumps of Leptothrix Sheaths

    Science.gov (United States)

    Kunoh, Tatsuki; Nagaoka, Noriyuki; McFarlane, Ian R.; Tamura, Katsunori; El-Naggar, Mohamed Y.; Kunoh, Hitoshi; Takada, Jun

    2016-01-01

    Species of the Fe/Mn-oxidizing bacteria Leptothrix produce tremendous amounts of microtubular, Fe/Mn-encrusted sheaths within a few days in outwells of groundwater that can rapidly clog water systems. To understand this mode of rapid sheath production and define the timescales involved, behaviors of sheath-forming Leptothrix sp. strain OUMS1 were examined using time-lapse video at the initial stage of sheath formation. OUMS1 formed clumps of tangled sheaths. Electron microscopy confirmed the presence of a thin layer of bacterial exopolymer fibrils around catenulate cells (corresponding to the immature sheath). In time-lapse videos, numerous sheath filaments that extended from the periphery of sheath clumps repeatedly fragmented at the apex of the same fragment, the fragments then aggregated and again elongated, eventually forming a large sheath clump comprising tangled sheaths within two days. In this study, we found that fast microscopic fragmentation, dissociation, re-aggregation and re-elongation events are the basis of the rapid, massive production of Leptothrix sheaths typically observed at macroscopic scales. PMID:27490579

  7. Spine Patterning Is Guided by Segmentation of the Notochord Sheath

    NARCIS (Netherlands)

    Wopat, Susan; Bagwell, Jennifer; Sumigray, Kaelyn D.; Dickson, Amy L.; Huitema, Leonie F.A.; Poss, Kenneth D.; Schulte-Merker, Stefan; Bagnat, Michel

    2018-01-01

    The spine is a segmented axial structure made of alternating vertebral bodies (centra) and intervertebral discs (IVDs) assembled around the notochord. Here, we show that, prior to centra formation, the outer epithelial cell layer of the zebrafish notochord, the sheath, segments into alternating

  8. Flow in rod bundles

    International Nuclear Information System (INIS)

    Hazi, G.; Mayer, G.

    2005-01-01

    For power upgrading VVER-440 reactors we need to know exactly how the temperature measured by the thermocouples is related to the average outlet temperature of the fuel assemblies. Accordingly, detailed knowledge on mixing process in the rod bundles and in the fuel assembly head have great importance. Here we study the hydrodynamics of rod bundles based on the results of direct numerical and large eddy simulation of flows in subchannels. It is shown that secondary flow and flow pulsation phenomena can be observed using both methodologies. Some consequences of these observations are briefly discussed. (author)

  9. Standard-model bundles

    CERN Document Server

    Donagi, Ron; Pantev, Tony; Waldram, Dan; Donagi, Ron; Ovrut, Burt; Pantev, Tony; Waldram, Dan

    2002-01-01

    We describe a family of genus one fibered Calabi-Yau threefolds with fundamental group ${\\mathbb Z}/2$. On each Calabi-Yau $Z$ in the family we exhibit a positive dimensional family of Mumford stable bundles whose symmetry group is the Standard Model group $SU(3)\\times SU(2)\\times U(1)$ and which have $c_{3} = 6$. We also show that for each bundle $V$ in our family, $c_{2}(Z) - c_{2}(V)$ is the class of an effective curve on $Z$. These conditions ensure that $Z$ and $V$ can be used for a phenomenologically relevant compactification of Heterotic M-theory.

  10. Data on the effect of in vivo knockdown using artificial ErbB3 miRNA on Remak bundle structure

    Directory of Open Access Journals (Sweden)

    Yuki Miyamoto

    2017-06-01

    Full Text Available Mature Schwann cells, the peripheral nervous system (PNS glial cells, have two major roles for neuronal axons (Bunge, 1993 [1]. For large diameter axons, Schwann cells form myelin sheaths with multiple layers. For small diameter axons, they form Remak bundle composed only of single layer of the Schwann cell plasma membrane. In the PNS, ErbB3 forms a dimer with ErbB2 on the Schwann cell plasma membrane. ErbB3 plays a key role in myelination by myelinating Schwann cells, that is to say, its role in myelin thickness. Herein we provide the data regarding the effect of in vivo knockdown of ErbB3 on the thickness between an axon and a neighboring axon in Remak bundle, which is formed by non-myelinating Schwann cells. Since ErbB3 knockout mice are embryonically lethal, Schwann cell lineage-specific transgenic mice transcribing ErbB3 shRNA with an artificial miRNA backbone were generated and used in these experiments (Torii et al., 2014 [2].

  11. Performance of candu-6 fuel bundles manufactured in romania nuclear fuel plant

    International Nuclear Information System (INIS)

    Bailescu, A.; Barbu, A.; Din, F.; Dinuta, G.; Dumitru, I.; Musetoiu, A.; Serban, G.; Tomescu, A.

    2013-01-01

    The purpose of this article is to present the performance of nuclear fuel produced by Nuclear Fuel Plant (N.F.P.) - Pitesti during 1995 - 2012 and irradiated in units U1 and U2 from Nuclear Power Plant (N.P.P.) Cernavoda and also present the Nuclear Fuel Plant (N.F.P.) - Pitesti concern for providing technology to prevent the failure causes of fuel bundles in the reactor. This article presents Nuclear Fuel Plant (N.F.P.) - Pitesti experience on tracking performance of nuclear fuel in reactor and strategy investigation of fuel bundles notified as suspicious and / or defectives both as fuel element and fuel bundle, it analyzes the possible defects that can occur at fuel bundle or fuel element and can lead to their failure in the reactor. Implementation of modern technologies has enabled optimization of manufacturing processes and hence better quality stability of achieving components (end caps, chamfered sheath), better verification of end cap - sheath welding. These technologies were qualified by Nuclear Fuel Plant (N.F.P.) - Pitesti on automatic and Computer Numerical Control (C.N.C.) programming machines. A post-irradiation conclusive analysis which will take place later this year (2013) in Institute for Nuclear Research Pitesti (the action was initiated earlier this year by bringing a fuel bundle which has been reported defective by pool visual inspection) will provide additional information concerning potential damage causes of fuel bundles due to manufacturing processes. (authors)

  12. Non-Maxwellian plasma sheaths

    International Nuclear Information System (INIS)

    Haines, M.G.

    1998-01-01

    There is much experimental evidence that heat flux to divertor plates or to limiters is very asymmetric. For example, Lowry made measurements on poloidal limiters in JET, Stangeby and McCracken reported asymmetries in several experiments. In 1991 Haines considered the effects on the Child-Langmuir sheaths of having a net current flow. It was found that a sheath that receives more ions than electrons receives more energy flux than a sheath that receives more electrons than ions. We now extend the model to include for the electrons departures from a Maxwellian distribution arising from a net current flow, heat flow and thermoelectric effects in the scrape-off layer (SOL). It is envisaged that a net current flows in the SOL due to applied or induced electric fields, and is of a magnitude similar to that in the adjacent bulk plasma, though reduced due to the lower temperature in the SOL. We employ conventional linear transport theory eg. Braginskii, Epperlein and Haines in which the ions are a stationary Maxwellian. (orig.)

  13. ELESTRES: performance of nuclear fuel, circumferential ridging, and multiaxial elastic-plastic stresses in sheaths

    International Nuclear Information System (INIS)

    Tayal, M.

    1986-10-01

    The finite element code ELESTRES models the two-dimensional axisymmetric behaviour of a CANDU fuel element during normal operation. The main focus of the code is to estimate temperatures, fission gas release, and axial variations of deformation/stresses in the pellet and in the sheath. Thus the code is able to predict details like stresses/strains at circumferential ridges. This paper describes the current version of ELESTRES. The emphasis is on a recent addition: multiaxial stresses in the sheath near circumferential ridges. For accuracy in the critical region, a fine mesh is used near the ridge. To keep computing costs low, a coarse mesh is used near the midplane of the pellet. Predictions of ELESTRES show good agreement with abouth 80 measurements of fission-gas-release. In this paper, we also present ELESTRES predictions of hoop strains in sheaths, for two irradiations: element ABS and bundle GB. For both irradiations, predictions, compare favourably with measurements. An illustrative example shows that near circumferential ridges, bending contributes to multiaxial stresses in the sheath. This can have a significant effect on sheath integrity, such as during stress-corrosion-cracking due to power-increases, or during corrosion-assisted-fatigue due to power cycling

  14. Irradiated fuel bundle counter

    International Nuclear Information System (INIS)

    Campbell, J.W.; Todd, J.L.

    1975-01-01

    The design of a prototype safeguards instrument for determining the number of irradiated fuel assemblies leaving an on-power refueled reactor is described. Design details include radiation detection techniques, data processing and display, unattended operation capabilities and data security methods. Development and operating history of the bundle counter is reported. (U.S.)

  15. Irradiated fuel bundle counter

    International Nuclear Information System (INIS)

    Campbell, J.W.; Todd, J.L.

    1975-01-01

    The design of a prototype safeguards instrument for determining the number of irradiated fuel assemblies leaving an on-power refueled reactor is described. Design details include radiation detection techniques, data processing and display, unattended operation capabilities and data security methods. Development and operating history of the bundle counter is reported

  16. ALUMINUM BOX BUNDLING PRESS

    Directory of Open Access Journals (Sweden)

    Iosif DUMITRESCU

    2015-05-01

    Full Text Available In municipal solid waste, aluminum is the main nonferrous metal, approximately 80- 85% of the total nonferrous metals. The income per ton gained from aluminum recuperation is 20 times higher than from glass, steel boxes or paper recuperation. The object of this paper is the design of a 300 kN press for aluminum box bundling.

  17. Kernel bundle EPDiff

    DEFF Research Database (Denmark)

    Sommer, Stefan Horst; Lauze, Francois Bernard; Nielsen, Mads

    2011-01-01

    In the LDDMM framework, optimal warps for image registration are found as end-points of critical paths for an energy functional, and the EPDiff equations describe the evolution along such paths. The Large Deformation Diffeomorphic Kernel Bundle Mapping (LDDKBM) extension of LDDMM allows scale space...

  18. Benign nerve sheath tumor of stomach

    International Nuclear Information System (INIS)

    Chaudry, N.U.; Zafar, S.; Haque, I.U.

    2007-01-01

    Gastrointestinal mesenchymal tumors are a group of tumors, which originate from the mesenchymal stem cells of the gastrointestinal tract. Gastric schwannoma is a very rare gastrointestinal mesenchymal tumor, which represents only 0.2% of all gastric tumors and 4% of all benign gastric neoplasms. We report a 55 years old lady who suffered from pain epigastrium, vomiting, occasionally with blood, loss of appetite and weight loss. Endoscopic examination showed a round submucosal tumor with a central ulceration along the greater curvature of the stomach. The pathological examination revealed a picture of spindle cell tumor. Immunohistochemical stain was strongly positive for S-100 protein stain, and non-reactive for CD34, CD117, consistent with benign nerve sheath tumor of stomach i.e. gastric schwannoma. (author)

  19. RF sheaths for arbitrary B field angles

    Science.gov (United States)

    D'Ippolito, Daniel; Myra, James

    2014-10-01

    RF sheaths occur in tokamaks when ICRF waves encounter conducting boundaries and accelerate electrons out of the plasma. Sheath effects reduce the efficiency of ICRF heating, cause RF-specific impurity influxes from the edge plasma, and increase the plasma-facing component damage. The rf sheath potential is sensitive to the angle between the B field and the wall, the ion mobility and the ion magnetization. Here, we obtain a numerical solution of the non-neutral rf sheath and magnetic pre-sheath equations (for arbitrary values of these parameters) and attempt to infer the parametric dependences of the Child-Langmuir law. This extends previous work on the magnetized, immobile ion regime. An important question is how the rf sheath voltage distributes itself between sheath and pre-sheath for various B field angles. This will show how generally previous estimates of the rf sheath voltage and capacitance were reasonable, and to improve the RF sheath BC. Work supported by US DOE grants DE-FC02-05ER54823 and DE-FG02-97ER54392.

  20. Formation of Stylet Sheaths in āere (in air from eight species of phytophagous hemipterans from six families (Suborders: Auchenorrhyncha and Sternorrhyncha.

    Directory of Open Access Journals (Sweden)

    J Kent Morgan

    Full Text Available Stylet sheath formation is a common feature among phytophagous hemipterans. These sheaths are considered essential to promote a successful feeding event. Stylet sheath compositions are largely unknown and their mode of solidification remains to be elucidated. This report demonstrates the formation and solidification of in āere (in air produced stylet sheaths by six hemipteran families: Diaphorina citri (Psyllidae, Asian citrus psyllid, Aphis nerii (Aphididae, oleander/milkweed aphid, Toxoptera citricida (Aphididae, brown citrus aphid, Aphis gossypii (Aphididae, cotton melon aphid, Bemisia tabaci biotype B (Aleyrodidae, whitefly, Homalodisca vitripennis (Cicadellidae, glassy-winged sharpshooter, Ferrisia virgata (Pseudococcidae, striped mealybug, and Protopulvinaria pyriformis (Coccidae, pyriform scale. Examination of in āere produced stylet sheaths by confocal and scanning electron microscopy shows a common morphology of an initial flange laid down on the surface of the membrane followed by continuous hollow core structures with sequentially stacked hardened bulbous droplets. Single and multi-branched sheaths were common, whereas mealybug and scale insects typically produced multi-branched sheaths. Micrographs of the in āere formed flanges indicate flange sealing upon stylet bundle extraction in D. citri and the aphids, while the B. tabaci whitefly and H. vitripennis glassy-winged sharpshooter flanges remain unsealed. Structural similarity of in āere sheaths are apparent in stylet sheaths formed in planta, in artificial diets, or in water. The use of 'Solvy', a dissolvable membrane, for intact stylet sheath isolation is reported. These observations illustrate for the first time this mode of stylet sheath synthesis adding to the understanding of stylet sheath formation in phytophagous hemipterans and providing tools for future use in structural and compositional analysis.

  1. Bundling Actin Filaments From Membranes: Some Novel Players

    Directory of Open Access Journals (Sweden)

    Clément eThomas

    2012-08-01

    Full Text Available Progress in live-cell imaging of the cytoskeleton has significantly extended our knowledge about the organization and dynamics of actin filaments near the plasma membrane of plant cells. Noticeably, two populations of filamentous structures can be distinguished. On the one hand, fine actin filaments which exhibit an extremely dynamic behavior basically characterized by fast polymerization and prolific severing events, a process referred to as actin stochastic dynamics. On the other hand, thick actin bundles which are composed of several filaments and which are comparatively more stable although they constantly remodel as well. There is evidence that the actin cytoskeleton plays critical roles in trafficking and signaling at both the cell cortex and organelle periphery but the exact contribution of actin bundles remains unclear. A common view is that actin bundles provide the long-distance tracks used by myosin motors to deliver their cargo to growing regions and accordingly play a particularly important role in cell polarization. However, several studies support that actin bundles are more than simple passive highways and display multiple and dynamic roles in the regulation of many processes, such as cell elongation, polar auxin transport, stomatal and chloroplast movement, and defense against pathogens. The list of identified plant actin-bundling proteins is ever expanding, supporting that plant cells shape structurally and functionally different actin bundles. Here I review the most recently characterized actin-bundling proteins, with a particular focus on those potentially relevant to membrane trafficking and/or signaling.

  2. Ultrasound diagnosis of rectus sheath hematoma

    International Nuclear Information System (INIS)

    Hwang, M. S.; Chang, J. C.; Rhee, C. B.

    1984-01-01

    6 cases of rectus sheath hematoma were correctly diagnosed by ultrasound. 2 cases had bilateral rectus sheath hematoma and 4 cases were unilateral. On ultrasound finding, relatively well defined oval or spindle like cystic mass situated in the area of rectus muscle on all cases. Ultrasound examination may give more definite diagnosis and extension rectus sheath hematoma and also helpful to follow up study of hematoma

  3. Right bundle branch block

    DEFF Research Database (Denmark)

    Bussink, Barbara E; Holst, Anders Gaarsdal; Jespersen, Lasse

    2013-01-01

    AimsTo determine the prevalence, predictors of newly acquired, and the prognostic value of right bundle branch block (RBBB) and incomplete RBBB (IRBBB) on a resting 12-lead electrocardiogram in men and women from the general population.Methods and resultsWe followed 18 441 participants included...... in the Copenhagen City Heart Study examined in 1976-2003 free from previous myocardial infarction (MI), chronic heart failure, and left bundle branch block through registry linkage until 2009 for all-cause mortality and cardiovascular outcomes. The prevalence of RBBB/IRBBB was higher in men (1.4%/4.7% in men vs. 0.......5%/2.3% in women, P block was associated with significantly...

  4. Reminiscences Of The First His Bundle Electrography In India

    Directory of Open Access Journals (Sweden)

    Nambiar C.A

    2002-04-01

    Full Text Available Dr Onkar Narula was making a huge wave those days with his work on His Bundle Electrocardiography and Corrected Sinus Node Recovery Time. He visited us in late 1972 or early 1973,probably the latter date. Till then venous catheterizations (including pacing were done by open cut down. I remember the first time we used venous sheath through right femoral vein. Dr Bhatia was the operator and I was assisting him and Dr Savithri Srivasthava was the senior Registrar. With Dr Narula showing the way we did the first His Bundle Recording and I analysed the whole roll manually as was the method those days. We had to improvise a junction box as the recording equipment did not have a proper connecting accessory at that time. After Dr Narula left we did His Bundle recording on many more patients and undertook a study. This was published as: Effect of acute digitalization on His Bundle Intervals and Corrected Sinus Node Recovery Time in young adults.M.L.Bhatia,C.Ashokan Nambiar,S.Shrivastava and Sujoy B.Roy: Indian Heart Journal:Vol-2:1977.1The article was received for publication on 29/11/1973 as acknowledged underneath, but strangely it took a long time to come in print. I have preserved some of the cath rolls and reprint of the article.

  5. Photovoltaic sheathing element with one or more tabs

    Energy Technology Data Exchange (ETDEWEB)

    Keenihan, James R; Langmaid, Joseph A; Lopez, Leonardo C.

    2017-02-07

    The present invention is premised upon an assembly that includes at least a photovoltaic sheathing element capable of being affixed on a building structure. The shingle including at least a photovoltaic cell assembly, a body portion attached to one or more portions of the photovoltaic cell assembly. Wherein the body portion includes one or more top peripheral tabs each capable of fitting under one or more vertically adjoining devices.

  6. Tendon sheath fibroma in the thigh.

    Science.gov (United States)

    Moretti, Vincent M; Ashana, Adedayo O; de la Cruz, Michael; Lackman, Richard D

    2012-04-01

    Tendon sheath fibromas are rare, benign soft tissue tumors that are predominantly found in the fingers, hands, and wrists of young adult men. This article describes a tendon sheath fibroma that developed in the thigh of a 70-year-old man, the only known tendon sheath fibroma to form in this location. Similar to tendon sheath fibromas that develop elsewhere, our patient's lesion presented as a painless, slow-growing soft tissue nodule. Physical examination revealed a firm, nontender mass with no other associated signs or symptoms. Although the imaging appearance of tendon sheath fibromas varies, our patient's lesion appeared dark on T1- and bright on T2-weighted magnetic resonance imaging. It was well marginated and enhanced with contrast.Histologically, tendon sheath fibromas are composed of dense fibrocollagenous stromas with scattered spindle-shaped fibroblasts and narrow slit-like vascular spaces. Most tendon sheath fibromas can be successfully removed by marginal excision, although 24% of lesions recur. No lesions have metastasized. Our patient's tendon sheath fibroma was removed by marginal excision, and the patient remained disease free 35 months postoperatively. Despite its rarity, tendon sheath fibroma should be included in the differential diagnosis of a thigh mass on physical examination or imaging, especially if it is painless, nontender, benign appearing, and present in men. Copyright 2012, SLACK Incorporated.

  7. Bundling harvester; Nippukorjausharvesteri

    Energy Technology Data Exchange (ETDEWEB)

    Koponen, K. [Eko-Log Oy, Kuopio (Finland)

    1996-12-31

    The staring point of the project was to design and construct, by taking the silvicultural point of view into account, a harvesting and processing system especially for energy-wood, containing manually driven bundling harvester, automatizing of the harvester, and automatized loading. The equipment forms an ideal method for entrepreneur`s-line harvesting. The target is to apply the system also for owner`s-line harvesting. The profitability of the system promotes the utilization of the system in both cases. The objectives of the project were: to construct a test equipment and prototypes for all the project stages, to carry out terrain and strain tests in order to examine the usability and durability, as well as the capacity of the machine, to test the applicability of the Eko-Log system in simultaneous harvesting of energy and pulp woods, and to start the marketing and manufacturing of the products. The basic problems of the construction of the bundling harvester have been solved using terrain-tests. The prototype machine has been shown to be operable. Loading of the bundles to form sufficiently economically transportable loads has been studied, and simultaneously, the branch-biomass has been tried to be utilized without loosing the profitability of transportation. The results have been promising, and will promote the profitable utilization of wood-energy

  8. Bundling harvester; Nippukorjausharvesteri

    Energy Technology Data Exchange (ETDEWEB)

    Koponen, K [Eko-Log Oy, Kuopio (Finland)

    1997-12-31

    The staring point of the project was to design and construct, by taking the silvicultural point of view into account, a harvesting and processing system especially for energy-wood, containing manually driven bundling harvester, automatizing of the harvester, and automatized loading. The equipment forms an ideal method for entrepreneur`s-line harvesting. The target is to apply the system also for owner`s-line harvesting. The profitability of the system promotes the utilization of the system in both cases. The objectives of the project were: to construct a test equipment and prototypes for all the project stages, to carry out terrain and strain tests in order to examine the usability and durability, as well as the capacity of the machine, to test the applicability of the Eko-Log system in simultaneous harvesting of energy and pulp woods, and to start the marketing and manufacturing of the products. The basic problems of the construction of the bundling harvester have been solved using terrain-tests. The prototype machine has been shown to be operable. Loading of the bundles to form sufficiently economically transportable loads has been studied, and simultaneously, the branch-biomass has been tried to be utilized without loosing the profitability of transportation. The results have been promising, and will promote the profitable utilization of wood-energy

  9. Retroperitoneal and rectus sheath hematomas.

    Science.gov (United States)

    Kasotakis, George

    2014-02-01

    The retroperitoneum is rich in vascular structures and can harbor large hematomas, traumatic or spontaneous. The management of retroperitoneal hematomas depends on the mechanism of injury and whether they are pulsatile/expanding. Rectus sheath hematomas are uncommon abdominal wall hematomas secondary to trauma to the epigastric arteries of the rectus muscle. The common risk factors include anticoagulation, strenuous exercise, coughing, coagulation disorders, and invasive procedures on/through the abdominal wall. The management is largely supportive, with the reversal of anticoagulation and transfusions; angioembolization may be necessary. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. SEU43 fuel bundles in CANDU 600

    International Nuclear Information System (INIS)

    Catana, Alexandru; Prodea, Iosif; Danila, Nicolae; Prisecaru, Ilie; Dupleac, Daniel

    2008-01-01

    Cernavoda Unit 1 and Unit 2 are pressure tube 650 MWe nuclear stations moderated and cooled with heavy water, of Canada design, located in Romania. Fuelling is on-power and the plant is currently fuelled with natural uranium dioxide. Fuel is encapsulated in a 37 fuel rod assembly having a specific standard geometry (STD37). In order to reduce fuel cycle costs programs were initiated in Canada, South Korea and at SCN Pitesti, Romania for design and build of a new, improved geometry fuel bundle and some fuel compositions. Among fuel compositions, which are considered, is the slightly enriched uranium (SEU) fuel (0.96 w% U-235) with an associated burn-up increase from ∼7900 MWd/tU up to ∼15000 MWd/tU. Neutron analysis showed that the Canadian-Korean fuel bundle geometry with 43 rods called SEU (SEU43) can be used in already operated reactors. A new fuel bundle resulted. Extended, comprehensive analysis must be conducted in order to assess the TH behavior of SEU43 besides the neutron, mechanical (drag force, etc) analyses. In this paper, using the sub-channel approach, main thermal-hydraulic parameters were analyzed: pressure drop; fuel, sheath and coolant temperatures; coolant density; critical heat flux. Some significant differences versus standard fuel are outlined in the paper and some conclusions are drawn. While, by using this new fuel, there are many benefits to be attained like: fuel costs reduction, spent fuel waste minimization, increase in competitiveness of nuclear power generation against other sources of generation, etc., the safety margins must be, at least, conserved. The introduction of a new fuel bundle type, different in geometry and fuel composition, requires a detailed preparation, a testing program and a series of neutron and thermal-hydraulic analysis. The results reported by this paper is part of this effort. The feasibility to increase the enrichment from 0.71% U-235 (NU) to 0.96% U-235, with an estimated burn-up increase up to 14000 MWd

  11. Collagen-based mechanical anisotropy of the tectorial membrane: implications for inter-row coupling of outer hair cell bundles.

    Directory of Open Access Journals (Sweden)

    Núria Gavara

    Full Text Available The tectorial membrane (TM in the mammalian cochlea displays anisotropy, where mechanical or structural properties differ along varying directions. The anisotropy arises from the presence of collagen fibrils organized in fibers of approximately 1 microm diameter that run radially across the TM. Mechanical coupling between the TM and the sensory epithelia is required for normal hearing. However, the lack of a suitable technique to measure mechanical anisotropy at the microscale level has hindered understanding of the TM's precise role.Here we report values of the three elastic moduli that characterize the anisotropic mechanical properties of the TM. Our novel technique combined Atomic Force Microscopy (AFM, modeling, and optical tracking of microspheres to determine the elastic moduli. We found that the TM's large mechanical anisotropy results in a marked transmission of deformations along the direction that maximizes sensory cell excitation, whereas in the perpendicular direction the transmission is greatly reduced.Computational results, based on our values of elastic moduli, suggest that the TM facilitates the directional cooperativity of sensory cells in the cochlea, and that mechanical properties of the TM are tuned to guarantee that the magnitude of sound-induced tip-link stretching remains similar along the length of the cochlea. Furthermore, we anticipate our assay to be a starting point for other studies of biological tissues that require directional functionality.

  12. The Atiyah bundle and connections on a principal bundle

    Indian Academy of Sciences (India)

    be the fiber bundle constructed as in (1.1) for the universal principal G-bundle. In a work in progress, we hope to show that the universal G-connection can be realized as a fiber bundle over C(EG). Turning this ... a G-invariant vector field on EG|U . In other words, we get a bijective linear map between. A(EG)(U) (the space of ...

  13. Bundling of elastic filaments induced by hydrodynamic interactions

    Science.gov (United States)

    Man, Yi; Page, William; Poole, Robert J.; Lauga, Eric

    2017-12-01

    Peritrichous bacteria swim in viscous fluids by rotating multiple helical flagellar filaments. As the bacterium swims forward, all its flagella rotate in synchrony behind the cell in a tight helical bundle. When the bacterium changes its direction, the flagellar filaments unbundle and randomly reorient the cell for a short period of time before returning to their bundled state and resuming swimming. This rapid bundling and unbundling is, at its heart, a mechanical process whereby hydrodynamic interactions balance with elasticity to determine the time-varying deformation of the filaments. Inspired by this biophysical problem, we present in this paper what is perhaps the simplest model of bundling whereby two or more straight elastic filaments immersed in a viscous fluid rotate about their centerline, inducing rotational flows which tend to bend the filaments around each other. We derive an integrodifferential equation governing the shape of the filaments resulting from mechanical balance in a viscous fluid at low Reynolds number. We show that such equation may be evaluated asymptotically analytically in the long-wavelength limit, leading to a local partial differential equation governed by a single dimensionless bundling number. A numerical study of the dynamics predicted by the model reveals the presence of two configuration instabilities with increasing bundling numbers: first to a crossing state where filaments touch at one point and then to a bundled state where filaments wrap along each other in a helical fashion. We also consider the case of multiple filaments and the unbundling dynamics. We next provide an intuitive physical model for the crossing instability and show that it may be used to predict analytically its threshold and adapted to address the transition to a bundling state. We then use a macroscale experimental implementation of the two-filament configuration in order to validate our theoretical predictions and obtain excellent agreement. This long

  14. Effective thermal conductivity of a heat generating rod bundle dissipating heat by natural convection and radiation

    International Nuclear Information System (INIS)

    Senve, Vinay; Narasimham, G.S.V.L.

    2011-01-01

    Highlights: → Transport processes in isothermal hexagonal sheath with 19 heat generating rods is studied. → Correlation is given to predict the maximum temperature considering all transport processes. → Effective thermal conductivity of rod bundle can be obtained using max temperature. → Data on the critical Rayleigh numbers for p/d ratios of 1.1-2.0 is presented. → Radiative heat transfer contributes to heat dissipation of 38-65% of total heat. - Abstract: A numerical study of conjugate natural convection and surface radiation in a horizontal hexagonal sheath housing 19 solid heat generating rods with cladding and argon as the fill gas, is performed. The natural convection in the sheath is driven by the volumetric heat generation in the solid rods. The problem is solved using the FLUENT CFD code. A correlation is obtained to predict the maximum temperature in the rod bundle for different pitch-to-diameter ratios and heat generating rates. The effective thermal conductivity is related to the heat generation rate, maximum temperature and the sheath temperature. Results are presented for the dimensionless maximum temperature, Rayleigh number and the contribution of radiation with changing emissivity, total wattage and the pitch-to-diameter ratio. In the simulation of a larger system that contains a rod bundle, the effective thermal conductivity facilitates simplified modelling of the rod bundle by treating it as a solid of effective thermal conductivity. The parametric studies revealed that the contribution of radiation can be 38-65% of the total heat generation, for the parameter ranges chosen. Data for critical Rayleigh number above which natural convection comes into effect is also presented.

  15. Managing bundled payments.

    Science.gov (United States)

    Draper, Andrew

    2011-04-01

    Results of Medicare's ACE demonstration project and Geisinger Health System's ProvenCare initiative provide insight into the challenges hospitals will face as bundled payment proliferates. An early analysis of these results suggests that hospitals would benefit from bringing full automation using clinical IT tools to bear in their efforts to meet these challenges. Other important factors contributing to success include board and physician leadership, organizational structure, pricing methodology for bidding, evidence-based medical practice guidelines, supply cost management, process efficiency management, proactive and aggressive case management, business development and marketing strategy, and the financial management system.

  16. Muon bundles from the Universe

    Directory of Open Access Journals (Sweden)

    Kankiewicz P.

    2018-01-01

    Full Text Available Recently the CERN ALICE experiment, in its dedicated cosmic ray run, observed muon bundles of very high multiplicities, thereby confirming similar findings from the LEP era at CERN (in the CosmoLEP project. Significant evidence for anisotropy of arrival directions of the observed high multiplicity muonic bundles is found. Estimated directionality suggests their possible extragalactic provenance. We argue that muonic bundles of highest multiplicity are produced by strangelets, hypothetical stable lumps of strange quark matter infiltrating our Universe.

  17. Infinitesimal bundles and projective relativity

    International Nuclear Information System (INIS)

    Evans, G.T.

    1973-01-01

    An intrinsic and global presentation of five-dimensional relativity theory is developed, in which special coordinate conditions are replaced by conditions of Lie invariance. The notion of an infinitesimal bundle is introduced, and the theory of connexions on principal bundles is extended to infinitesimal bundles. Global aspects of projective relativity are studied: it is shown that projective relativity can describe almost any space-time. In particular, it is not necessary to assume that the electromagnetic field have a global potential. (author)

  18. The Tubular Sheaths Encasing Methanosaeta and Methanospirillum Filaments are Functional Amyloids

    DEFF Research Database (Denmark)

    Dueholm, Morten Simonsen; Larsen, Poul; Nielsen, Per Halkjær

    Archaea are well-recognized for their ability to thrive in extreme environments, although they can be found in virtually all habitats. Their adaptive success is linked to their unique cell envelopes, which often display extremely resistant to chemical and thermal denaturation and resist proteolysis...... techniques to show that the extracellular cell wall sheaths of the methanogenic archaea Methanosaeta and Methanospirillum are functional amyloid structures. Depolymerization of sheaths with formic acid and reducing agents and subsequent MS/MS analysis revealed that the sheaths are composed of a single major...... sheath protein (MspA). The amyloidogenic nature of MspA was confirmed by in vitro amyloid formation of recombinant MspA under a wide range of environmental conditions. This is the first report of a functional amyloid from the archaeal domain of life. The amyloid properties explain the extreme resistance...

  19. Primary optic nerve sheath meningioma

    Energy Technology Data Exchange (ETDEWEB)

    Jeremic, Branislav [International Atomic Energy Agency, Vienna (Austria); Pitz, Susanne (eds.) [University Eye Hospital, Mainz (Germany)

    2008-07-01

    Optic nerve sheath meningioma (ONSM) is a rare tumour. Cases are usually separated into primary ONSM, which arises either intraorbitally or, less commonly, intracanalicularly, and secondary ONSM, which arises intracranially and subsequently invades the optic canal and orbit. This is the first book to cover all important aspects of the diagnosis and treatment of primary ONSM. After a general introduction, individual chapters discuss the clinical presentation, clinical examination and diagnosis, imaging, and histology. Treatment options are then addressed in detail, with special emphasis on external beam radiation therapy, and in particular stereotactic fractionated radiation therapy. The latter has recently produced consistently good results and is now considered the emerging treatment of choice for the vast majority of patients with primary ONSM. This well-illustrated book will prove invaluable to all practitioners who encounter primary ONSM in their clinical work. (orig.)

  20. Interface between breast cancer cells and the tumor microenvironment using platelet-rich plasma to promote tumor angiogenesis - influence of platelets and fibrin bundles on the behavior of breast tumor cells.

    Science.gov (United States)

    Andrade, Sheila Siqueira; Sumikawa, Joana Tomomi; Castro, Eloísa Dognani; Batista, Fabricio Pereira; Paredes-Gamero, Edgar; Oliveira, Lilian Carolina; Guerra, Izabel Monastério; Peres, Giovani Bravin; Cavalheiro, Renan Pelluzzi; Juliano, Luiz; Nazário, Afonso Pinto; Facina, Gil; Tsai, Siu Mui; Oliva, Maria Luiza Vilela; Girão, Manoel João Batista Castello

    2017-03-07

    Cancer progression is associated with an evolving tissue interface of direct epithelial-tumor microenvironment interactions. In biopsies of human breast tumors, extensive alterations in molecular pathways are correlated with cancer staging on both sides of the tumor-stroma interface. These interactions provide a pivotal paracrine signaling to induce malignant phenotype transition, the epithelial-mesenchymal transition (EMT). We explored how the direct contact between platelets-fibrin bundles primes metastasis using platelet-rich plasma (PRP) as a source of growth factors and mimics the provisional fibrin matrix between actively growing breast cancer cells and the tumor stroma. We have demonstrated PRP functions, modulating cell proliferation that is tumor-subtype and cancer cell-type-specific. Epithelial and stromal primary cells were prepared from breast cancer biopsies from 21 women with different cancer subtypes. Cells supplemented with PRP were immunoblotted with anti-phospho and total Src-Tyr-416, FAK-Try-925, E-cadherin, N-cadherin, TGF-β, Smad2, and Snail monoclonal antibodies. Breast tumor cells from luminal B and HER2 subtypes showed the most malignant profiles and the expression of thrombin and other classes of proteases at levels that were detectable through FRET peptide libraries. The angiogenesis process was investigated in the interface obtained between platelet-fibrin-breast tumor cells co-cultured with HUVEC cells. Luminal B and HER2 cells showed robust endothelial cell capillary-like tubes ex vivo. The studied interface contributes to the attachment of endothelial cells, provides a source of growth factors, and is a solid substrate. Thus, replacement of FBS supplementation with PRP supplementation represents an efficient and simple approach for mimicking the real multifactorial tumor microenvironment.

  1. REBEKA bundle experiments

    International Nuclear Information System (INIS)

    Wiehr, K.

    1988-05-01

    This report is a summary of experimental investigations describing the fuel rod behavior in the refilling and reflooding phase of a loss-of-coolant accident of a PWR. The experiments were performed with 5x5 and 7x7 rod bundles, using indirectly electrically heated fuel rod simulators of full length with original PWR-KWU-geometry, original grid spacers and Zircaloy-4-claddings (Type Biblis B). The fuel rod simulators showed a cosine shaped axial power profile in 7 steps and continuous, respectively. The results describe the influence of the different parameters such as bundle size on the maximum coolant channel blockage, that of the cooling on the size of the circumferential strain of the cladding (azimuthal temperature distribution) a cold control rod guide thimble and the flow direction (axial temperature distribution) on the resulting coolant channel blockage. The rewetting behavior of different fuel rod simulators including ballooned and burst Zircaloy claddings is discussed as well as the influence of thermocouples on the cladding temperature history and the rewetting behavior. All results prove the coolability of a PWR in the case of a LOCA. Therefore, it can be concluded that the ECC-criteria established by licensing authorities can be fulfilled. (orig./HP) [de

  2. Nefness of adjoint bundles for ample vector bundles

    Directory of Open Access Journals (Sweden)

    Hidetoshi Maeda

    1995-11-01

    Full Text Available Let E be an ample vector bundle of rank >1 on a smooth complex projective variety X of dimension n. This paper gives a classification of pairs (X,E whose adjoint bundles K_X+det E are not nef in the case when  r=n-2.

  3. Genomic and Expression Profiling of Benign and Malignant Nerve Sheath Tumors in Neurofibromatosis Patients

    Science.gov (United States)

    2008-05-01

    DAMD17-03-1-0297 Title: Genomic and Expression Pr ofiling of Benign and Malignant Nerve Sheath Tumors in Neurofibromatosis Patients...have determined the gene expression signature for benign and malignant peripheral nerve sheath tumors and found that the major trend in transformation...However, EGFR data in soft tissue neoplasms is limited. Using a variety of benign and malignant spindle cell neoplasms, we assessed EGFR status by

  4. Assessment of ASSERT-PV for prediction of post-dryout heat transfer in CANDU bundles

    International Nuclear Information System (INIS)

    Cheng, Z.; Rao, Y.F.; Waddington, G.M.

    2014-01-01

    Highlights: • Assessment of the new Canadian subchannel code ASSERT-PV 3.2 for PDO sheath temperature prediction. • CANDU 28-, 37- and 43-element bundle PDO experiments. • Prediction improvement of ASSERT-PV 3.2 over previous code versions. • Sensitivity study of the effect of PDO model options. - Abstract: Atomic Energy of Canada Limited (AECL) has developed the subchannel thermalhydraulics code ASSERT-PV for the Canadian nuclear industry. The recently released ASSERT-PV 3.2 provides enhanced models for improved predictions of subchannel flow distribution, critical heat flux (CHF), and post-dryout (PDO) heat transfer in horizontal CANDU fuel channels. This paper presents results of an assessment of the new code version against PDO tests performed during five full-size CANDU bundle experiments conducted between 1992 and 2009 by Stern Laboratories (SL), using 28-, 37- and 43-element bundles. A total of 10 PDO test series with varying pressure-tube creep and/or bearing-pad height were analyzed. The SL experiments encompassed the bundle geometries and range of flow conditions for the intended ASSERT-PV applications for existing CANDU reactors. Code predictions of maximum PDO fuel-sheath temperature were compared against measurements from the SL PDO tests to quantify the code's prediction accuracy. The prediction statistics using the recommended model set of ASSERT-PV 3.2 were compared to those from previous code versions. Furthermore, separate-effects sensitivity studies quantified the contribution of each PDO model change or enhancement to the improvement in PDO heat transfer prediction. Overall, the assessment demonstrated significant improvement in prediction of PDO sheath temperature in horizontal fuel channels containing CANDU bundles

  5. Cytoplasmic pH dynamics in maize pulvinal cells induced by gravity vector changes

    Science.gov (United States)

    Johannes, E.; Collings, D. A.; Rink, J. C.; Allen, N. S.; Brown, C. S. (Principal Investigator)

    2001-01-01

    In maize (Zea mays) and other grasses, changes in orientation of stems are perceived by pulvinal tissue, which responds to the stimulus by differential growth resulting in upward bending of the stem. The amyloplast-containing bundle sheath cells are the sites of gravity perception, although the initial steps of gravity perception and transmission remain unclear. In columella cells of Arabidopsis roots, we previously found that cytoplasmic pH (pH(c)) is a mediator in early gravitropic signaling (A.C. Scott, N.S. Allen [1999] Plant Physiol 121: 1291-1298). The question arises whether pH(c) has a more general role in signaling gravity vector changes. Using confocal ratiometric imaging and the fluorescent pH indicator carboxy seminaphtorhodafluor acetoxymethyl ester acetate, we measured pH(c) in the cells composing the maize pulvinus. When stem slices were gravistimulated and imaged on a horizontally mounted confocal microscope, pH(c) changes were only apparent within the bundle sheath cells, and not in the parenchyma cells. After turning, cytoplasmic acidification was observed at the sides of the cells, whereas the cytoplasm at the base of the cells where plastids slowly accumulated became more basic. These changes were most apparent in cells exhibiting net amyloplast sedimentation. Parenchyma cells and isolated bundle sheath cells did not show any gravity-induced pH(c) changes although all cell types responded to external stimuli in the predicted way: Propionic acid and auxin treatments induced acidification, whereas raising the external pH caused alkalinization. The results suggest that pH(c) has an important role in the early signaling pathways of maize stem gravitropism.

  6. Application of Spray Foam Insulation Under Plywood and Oriented Strand Board Roof Sheathing

    Energy Technology Data Exchange (ETDEWEB)

    Grin, A. [Building Science Corporation, Somerville, MA (United States); Smegal, J. [Building Science Corporation, Somerville, MA (United States); Lstiburek, J. [Building Science Corporation, Somerville, MA (United States)

    2013-10-01

    Unvented roof strategies with open cell and closed cell spray polyurethane foam insulation sprayed to the underside of roof sheathing have been used since the mid-1990's to provide durable and efficient building enclosures. However, there have been isolated moisture related incidents reported anecdotally that raise potential concerns about the overall hygrothermal performance of these systems. This project involved hygrothermal modeling of a range of rainwater leakage and field evaluations of in-service residential roofs using spray foam insulation. All of the roof assemblies modeled exhibited drying capacity to handle minor rainwater leakage. All field evaluation locations of in-service residential roofs had moisture contents well within the safe range for wood-based sheathing. Explorations of eleven in-service roof systems were completed. The exploration involved taking a sample of spray foam from the underside of the roof sheathing, exposing the sheathing, then taking a moisture content reading. All locations had moisture contents well within the safe range for wood-based sheathing. One full-roof failure was reviewed, as an industry partner was involved with replacing structurally failed roof sheathing. In this case the manufacturer's investigation report concluded that the spray foam was installed on wet OSB based on the observation that the spray foam did not adhere well to the substrate and the pore structure of the closed cell spray foam at the ccSPF/OSB interface was indicative of a wet substrate.

  7. Bundle Security Protocol for ION

    Science.gov (United States)

    Burleigh, Scott C.; Birrane, Edward J.; Krupiarz, Christopher

    2011-01-01

    This software implements bundle authentication, conforming to the Delay-Tolerant Networking (DTN) Internet Draft on Bundle Security Protocol (BSP), for the Interplanetary Overlay Network (ION) implementation of DTN. This is the only implementation of BSP that is integrated with ION.

  8. CANFLEX fuel bundle impact test

    International Nuclear Information System (INIS)

    Chang, Seok Kyu; Chung, C. H.; Park, J. S.; Hong, S. D.; Kim, B. D.

    1997-08-01

    This document outlines the test results for the impact test of the CANFLEX fuel bundle. Impact test is performed to determine and verify the amount of general bundle shape distortion and defect of the pressure tube that may occur during refuelling. The test specification requires that the fuel bundles and the pressure tube retain their integrities after the impact test under the conservative conditions (10 stationary bundles with 31kg/s flow rate) considering the pressure tube creep. The refuelling simulator operating with pneumatic force and simulated shield plug were fabricated and the velocity/displacement transducer and the high speed camera were also used in this test. The characteristics of the moving bundle (velocity, displacement, impacting force) were measured and analyzed with the impact sensor and the high speed camera system. The important test procedures and measurement results were discussed as follows. 1) Test bundle measurements and the pressure tube inspections 2) Simulated shield plug, outlet flange installation and bundle loading 3) refuelling simulator, inlet flange installation and sensors, high speed camera installation 4) Perform the impact test with operating the refuelling simulator and measure the dynamic characteristics 5) Inspections of the fuel bundles and the pressure tube. (author). 8 refs., 23 tabs., 13 figs

  9. Connections on discrete fibre bundles

    International Nuclear Information System (INIS)

    Manton, N.S.; Cambridge Univ.

    1987-01-01

    A new approach to gauge fields on a discrete space-time is proposed, in which the fundamental object is a discrete version of a principal fibre bundle. If the bundle is twisted, the gauge fields are topologically non-trivial automatically. (orig.)

  10. Sasakian and Parabolic Higgs Bundles

    Science.gov (United States)

    Biswas, Indranil; Mj, Mahan

    2018-03-01

    Let M be a quasi-regular compact connected Sasakian manifold, and let N = M/ S 1 be the base projective variety. We establish an equivalence between the class of Sasakian G-Higgs bundles over M and the class of parabolic (or equivalently, ramified) G-Higgs bundles over the base N.

  11. Rectus sheath abscess after laparoscopic appendicectomy

    Directory of Open Access Journals (Sweden)

    Golash Vishwanath

    2007-01-01

    Full Text Available Port site wound infection, abdominal wall hematoma and intraabdominal abscess formation has been reported after laparoscopic appendicectomy. We describe here a rectus sheath abscess which occurred three weeks after the laparoscopic appendicectomy. It was most likely the result of secondary infection of the rectus sheath hematoma due to bleeding into the rectus sheath from damage to the inferior epigastric arteries or a direct tear of the rectus muscle. As far as we are aware this complication has not been reported after laparoscopic appendicectomy.

  12. Twisted Vector Bundles on Pointed Nodal Curves

    Indian Academy of Sciences (India)

    Abstract. Motivated by the quest for a good compactification of the moduli space of -bundles on a nodal curve we establish a striking relationship between Abramovich's and Vistoli's twisted bundles and Gieseker vector bundles.

  13. Textor bundle divertor

    International Nuclear Information System (INIS)

    Yang, T.F.; Wan, A.; Gierszewski, P.; Rapperport, E.; Montgomery, D.B.

    1982-01-01

    This report presents a preliminary bundle divertor conceptual design for installation on the TEXTOR tokamak. An advanced cascade T-shaped coil configuration is used. This divertor design has the following important characteristics: (1) the current density in the conductor is less than 6 kAmp/cm 2 , and the maximum field is less than 6 Tesla; (2) the divertor can be operated at steady-state either for copper or superconducting conductors; (3) the power consumption is about 7 MW for a normal conductor; (4) the divertor can be inserted into the existing geometry of TEXTOR; (5) the ripple on axis is only 0.3% and the mirror ratio is 2 to 4; (6) the stagnation axis is concave toward the plasma, therefore q/sub D/ is smaller, the acceptance angle is larger, and the efficiency may be better than the conventional circular coil design

  14. TEXTOR bundle divertor

    International Nuclear Information System (INIS)

    Yang, T.F.; Wan, A.; Gierszewski, P.; Rapperport, E.; Montgomery, D.B.

    1982-01-01

    This report presents a preliminary bundle divertor conceptual design for installation on the TEXTOR tokamak. An advanced cascade T-shaped coil configuration is used. This divertor design has the following important characteristics: (1) the current density in the conductor is less than 6 kAmp/cm 2 , and the maximum field is less than 6 Tesla; (2) the divertor can be operated at steady-state either for copper or superconducting conductors; (3) the power consumption is about 7 MW for a normal conductor; (4) the divertor can be inserted into the existing geometry of TEXTOR; (5) the ripple on axis is only 0.3% and the mirror ratio is 2 to 4; (6) the stagnation axis is concave toward the plasma, therefore q/sub D/ is smaller, the acceptance angle is larger, and the efficiency may be better than the conventional circular coil design

  15. Reactor physics assessment of modified 37-element CANDU fuel bundles

    International Nuclear Information System (INIS)

    Pristavu, R.; Rizoiu, A.

    2016-01-01

    Reducing the central element diameter in order to improve the total flow area of CANDU fuel bundle and redistribute the power density of all remaining elements was studied in Canada and Korea when considering the effect of aging pressure tube diametral creep. The aim of this paper is to study the modified bundle behavior using the transport codes WIMS and DRAGON. In calculations, a WIMS nuclear data library on 172 energy groups was used. 2-D transport calculations were performed with WIMS and DRAGON, leading to similar results in estimated cell parameters. Additionally, 3-D DRAGON calculations were carried on in order to evaluate the local flux distribution shift, as well as the incremental cross sections for supercells containing modified CANDU bundles and reactivity devices. The overall effect of using modified fuel bundles was meaningless for both cell and supercell parameters, thus ensuring this possibility of fuel improvement for thermal-hydraulic purposes only. (authors)

  16. Effects of Fast-Ion Injection on a Magnetized Sheath near a Floating Wall

    International Nuclear Information System (INIS)

    Li Jiajia; Hu Zhanghu; Song Yuanhong; Wang Younian

    2013-01-01

    A fully kinetic particle-in-cell/Monte Carlo model is employed to self-consistently study the effects of fast-ion injection on sheath potential and electric field profile in collisional magnetized plasma with a floating absorbing wall. The influences of the fast-ion injection velocity and density, the magnetic field and angle θ 0 formed by the magnetic field and the x-axis on the sheath potential and electric field are discussed in detail. Numerical results show that increasing fast-ion injection density or decreasing injection velocity can enhance the potential drop and electric field in the sheath. Also, increasing the magnetic field strength can weaken the loss of charged particles to the wall and thus decrease the potential and electric field in the sheath. The time evolution of ion flux and velocity distribution on the wall is found to be significantly affected by the magnetic field.

  17. ASSERT-PV 3.2: Advanced subchannel thermalhydraulics code for CANDU fuel bundles

    International Nuclear Information System (INIS)

    Rao, Y.F.; Cheng, Z.; Waddington, G.M.; Nava-Dominguez, A.

    2014-01-01

    Highlights: • Introduction to a new version of the Canadian subchannel code, ASSERT-PV 3.2. • Enhanced models for flow-distribution, CHF and post-dryout heat transfer prediction. • Model changes focused on unique features of horizontal CANDU bundles. • Detailed description of model changes for all major thermalhydraulics models. • Discussion on rationale and limitation of the model changes. - Abstract: Atomic Energy of Canada Limited (AECL) has developed the subchannel thermalhydraulics code ASSERT-PV for the Canadian nuclear industry. The most recent release version, ASSERT-PV 3.2 has enhanced phenomenon models for improved predictions of flow distribution, dryout power and CHF location, and post-dryout (PDO) sheath temperature in horizontal CANDU fuel bundles. The focus of the improvements is mainly on modeling considerations for the unique features of CANDU bundles such as horizontal flows, small pitch to diameter ratios, high mass fluxes, and mixed and irregular subchannel geometries, compared to PWR/BWR fuel assemblies. This paper provides a general introduction to ASSERT-PV 3.2, and describes the model changes or additions in the new version to improve predictions of flow distribution, dryout power and CHF location, and PDO sheath temperatures in CANDU fuel bundles

  18. ASSERT-PV 3.2: Advanced subchannel thermalhydraulics code for CANDU fuel bundles

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Y.F., E-mail: raoy@aecl.ca; Cheng, Z., E-mail: chengz@aecl.ca; Waddington, G.M., E-mail: waddingg@aecl.ca; Nava-Dominguez, A., E-mail: navadoma@aecl.ca

    2014-08-15

    Highlights: • Introduction to a new version of the Canadian subchannel code, ASSERT-PV 3.2. • Enhanced models for flow-distribution, CHF and post-dryout heat transfer prediction. • Model changes focused on unique features of horizontal CANDU bundles. • Detailed description of model changes for all major thermalhydraulics models. • Discussion on rationale and limitation of the model changes. - Abstract: Atomic Energy of Canada Limited (AECL) has developed the subchannel thermalhydraulics code ASSERT-PV for the Canadian nuclear industry. The most recent release version, ASSERT-PV 3.2 has enhanced phenomenon models for improved predictions of flow distribution, dryout power and CHF location, and post-dryout (PDO) sheath temperature in horizontal CANDU fuel bundles. The focus of the improvements is mainly on modeling considerations for the unique features of CANDU bundles such as horizontal flows, small pitch to diameter ratios, high mass fluxes, and mixed and irregular subchannel geometries, compared to PWR/BWR fuel assemblies. This paper provides a general introduction to ASSERT-PV 3.2, and describes the model changes or additions in the new version to improve predictions of flow distribution, dryout power and CHF location, and PDO sheath temperatures in CANDU fuel bundles.

  19. Rectus sheath hematoma: three case reports

    Directory of Open Access Journals (Sweden)

    Kapan Selin

    2008-01-01

    Full Text Available Abstract Introduction Rectus sheath hematoma is an uncommon cause of acute abdominal pain. It is an accumulation of blood in the sheath of the rectus abdominis, secondary to rupture of an epigastric vessel or muscle tear. It could occur spontaneously or after trauma. They are usually located infraumblically and often misdiagnosed as acute abdomen, inflammatory diseases or tumours of the abdomen. Case presentation We reported three cases of rectus sheath hematoma presenting with a mass in the abdomen and diagnosed by computerized tomography. The patients recovered uneventfully after bed rest, intravenous fluid replacement, blood transfusion and analgesic treatment. Conclusion Rectus sheath hematoma is a rarely seen pathology often misdiagnosed as acute abdomen that may lead to unnecessary laparotomies. Computerized tomography must be chosen for definitive diagnosis since ultrasonography is subject to error due to misinterpretation of the images. Main therapy is conservative management.

  20. Fabrication of a CANFLEX-RU designed bundle for power ramp irradiation test in NRU

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Moon Sung

    2000-11-01

    The BDL-443 CANFLEX-RU bundle AKW was fabricated at Korea Atomic Energy Research Institute (KAERI) for power ramp irradiation testing in NRU reactor. The bundle was fabricated with IDR and ADU fuel pellets in adjacent elements and contains fuel pellets enriched to 1.65 wt% {sup 235}U in the outer and intermediate rings and also contains pellets enriched to 2.00 wt% {sup 235}U in the inner ring. This bundle does not have a center element to allow for insertion on a hanger bar. KAERI produced the IDR pellets with the IDR-source UO{sub 2} powder supplied by BNFL. ADU pellets were fabricated and supplied by AECL. Bundle kits (Zircaloy-4 end plates, end plugs, and sheaths with brazed appendages) manufactured at KAERI earlier in 1996 were used for the fabrication of the bundle. The CANFLEX bundle was fabricated successfully at KAERI according to the QA provisions specified in references and as per relevant KAERI drawings and technical specification. This report covers the fabrication activities performed at KAERI. Fabrication processes performed at AECL will be documented in a separate report.

  1. Fabrication of a CANFLEX-RU designed bundle for power ramp irradiation test in NRU

    International Nuclear Information System (INIS)

    Cho, Moon Sung

    2000-11-01

    The BDL-443 CANFLEX-RU bundle AKW was fabricated at Korea Atomic Energy Research Institute (KAERI) for power ramp irradiation testing in NRU reactor. The bundle was fabricated with IDR and ADU fuel pellets in adjacent elements and contains fuel pellets enriched to 1.65 wt% 235 U in the outer and intermediate rings and also contains pellets enriched to 2.00 wt% 235 U in the inner ring. This bundle does not have a center element to allow for insertion on a hanger bar. KAERI produced the IDR pellets with the IDR-source UO 2 powder supplied by BNFL. ADU pellets were fabricated and supplied by AECL. Bundle kits (Zircaloy-4 end plates, end plugs, and sheaths with brazed appendages) manufactured at KAERI earlier in 1996 were used for the fabrication of the bundle. The CANFLEX bundle was fabricated successfully at KAERI according to the QA provisions specified in references and as per relevant KAERI drawings and technical specification. This report covers the fabrication activities performed at KAERI. Fabrication processes performed at AECL will be documented in a separate report

  2. A sheath model for arbitrary radiofrequency waveforms

    Science.gov (United States)

    Turner, M. M.; Chabert, Pascal

    2012-10-01

    The sheath is often the most important region of a rf plasma, because discharge impedance, power absorption and ion acceleration are critically affected by the behaviour of the sheath. Consequently, models of the sheath are central to any understanding of the physics of rf plasmas. Lieberman has supplied an analytical model for a radio-frequency sheath driven by a single frequency, but in recent years interest has been increasing in radio-frequency discharges excited by increasingly complex wave forms. There has been limited success in generalizing the Lieberman model in this direction, because of mathematical complexities. So there is essentially no sheath model available to describe many modern experiments. In this paper we present a new analytical sheath model, based on a simpler mathematical framework than that of Lieberman. For the single frequency case, this model yields scaling laws that are identical in form to those of Lieberman, differing only by numerical coefficients close to one. However, the new model may be straightforwardly solved for arbitrary current waveforms, and may be used to derive scaling laws for such complex waveforms. In this paper, we will describe the model and present some illustrative examples.

  3. How to Patch Active Plasma and Collisionless Sheath: Practical Guide

    International Nuclear Information System (INIS)

    Kaganovich, Igor D.

    2002-01-01

    Most plasmas have a very thin sheath compared with the plasma dimension. This necessitates separate calculations of the plasma and sheath. The Bohm criterion provides the boundary condition for calculation of plasma profiles. To calculate sheath properties, a value of electric field at the plasma-sheath interface has to be specified in addition to the Bohm criterion. The value of the boundary electric field and robust procedure to approximately patch plasma and collisionless sheath with a very good accuracy are reported

  4. Evaluating big deal journal bundles.

    Science.gov (United States)

    Bergstrom, Theodore C; Courant, Paul N; McAfee, R Preston; Williams, Michael A

    2014-07-01

    Large commercial publishers sell bundled online subscriptions to their entire list of academic journals at prices significantly lower than the sum of their á la carte prices. Bundle prices differ drastically between institutions, but they are not publicly posted. The data that we have collected enable us to compare the bundle prices charged by commercial publishers with those of nonprofit societies and to examine the types of price discrimination practiced by commercial and nonprofit journal publishers. This information is of interest to economists who study monopolist pricing, librarians interested in making efficient use of library budgets, and scholars who are interested in the availability of the work that they publish.

  5. Nonsurgical giant cell tumour of the tendon sheath or of the diffuse type: Are MRI or 18F-FDG PET/CT able to provide an accurate prediction of long-term outcome?

    International Nuclear Information System (INIS)

    Dercle, Laurent; Chisin, Roland; Ammari, Samy; Gillebert, Quentin; Ouali, Monia; Jaudet, Cyril; Dierickx, Lawrence; Zerdoud, Slimane; Courbon, Frederic; Delord, Jean-Pierre; Schlumberger, Martin

    2015-01-01

    To investigate whether MRI (RECIST 1.1, WHO criteria and the volumetric approach) or 18 F-FDG PET/CT (PERCIST 1.0) are able to predict long-term outcome in nonsurgical patients with giant cell tumour of the tendon sheath or of the diffuse type (GCT-TS/DT). Fifteen ''nonsurgical'' patients with a histological diagnosis of GCT-TS/DT were divided into two groups: symptomatic patients receiving targeted therapy and asymptomatic untreated patients. All 15 patients were evaluated by MRI of whom 10 were treated, and a subgroup of 7 patients were evaluated by PET/CT of whom 4 were treated. Early evolution was assessed according to MRI and PET/CT scans at baseline and during follow-up. Cohen's kappa coefficient was used to evaluate the degree of agreement between PERCIST 1.0, RECIST 1.1, WHO criteria, volumetric approaches and the reference standard (long-term outcome, delay 505 ± 457 days). The response rate in symptomatic patients with GCT-TS/DT receiving targeted therapy was also assessed in a larger population that included additional patients obtained from a review of the literature. The kappa coefficients for agreement between RECIST/WHO/volumetric criteria and outcome (15 patients) were respectively: 0.35 (p = 0.06), 0.26 (p = 0.17) and 0.26 (p = 0.17). In the PET/CT subgroup (7 patients), PERCIST was in perfect agreement with the late symptomatic evolution (kappa = 1, p 18 F-FDG PET/CT with PERCIST is a promising approach to the prediction of the long-term outcome in GCT-TS/DT and may avoid unnecessary treatments, toxicity and costs. On MRI, WHO and volumetric approaches are not more effective than RECIST using the current thresholds. (orig.)

  6. Effects of an anode sheath on energy and momentum transfer in vacuum arcs

    International Nuclear Information System (INIS)

    Wang, Zhenxing; Zhou, Zhipeng; Tian, Yunbo; Wang, Haoran; Wang, Jianhua; Geng, Yingsan; Liu, Zhiyuan

    2017-01-01

    Anode phenomena under high-current vacuum arcs have a significant impact on the interrupting capacity of vacuum interrupters. However, the vacuum arc energy flux and momentum flux on the anode—which are necessary boundary conditions for simulations—are either set to an imaginary distribution or calculated using simple formulas without considering anode sheath regulatory effects. The objective of this paper is to reveal the anode sheath effects on regulating the energy and momentum transfer from the arc column to the anode surface in vacuum arcs. A particle-in-cell model for the anode sheath is developed. The required input parameters are obtained from a magnetohydrodynamic model for the arc column. From the results, there exists a sheath near the anode with a negative voltage drop. Both the electron density and the ion density significantly decline in the anode sheath region. The kinetic energy of the ions absorbed by the anode consists of directed kinetic energy, random kinetic energy, and sheath acceleration energy. The sheath acceleration energy contribution is the largest, and the random kinetic energy also accounts for a large part that cannot be ignored. The arc pressure on the anode surface is mainly caused by ion impact, and the accelerating effect of the anode sheath on the ions cannot be neglected in pressure calculations. In addition, in the case of an arc current at 15 kA, the input energy and momentum upon the anode surface is not obviously affected by the evaporated atoms at surface temperatures of 1600 K and 2000 K. (paper)

  7. Fibrin Sheath Angioplasty: A Technique to Prevent Superior Vena Cava Stenosis Secondary to Dialysis Catheters

    Science.gov (United States)

    Hacker, Robert I.; Garcia, Lorena De Marco; Chawla, Ankur; Panetta, Thomas F.

    2012-01-01

    Fibrin sheaths are a heterogeneous matrix of cells and debris that form around catheters and are a known cause of central venous stenosis and catheter failure. A total of 50 cases of central venous catheter fibrin sheath angioplasty (FSA) after catheter removal or exchange are presented. A retrospective review of an outpatient office database identified 70 eligible patients over a 19-month period. After informed consent was obtained, the dialysis catheter exiting the skin was clamped, amputated, and a wire was inserted. The catheter was then removed and a 9-French sheath was inserted into the superior vena cava, a venogram was performed. If a fibrin sheath was present, angioplasty was performed using an 8 × 4 or 10 × 4 balloon along the entire length of the fibrin sheath. A completion venogram was performed to document obliteration of the sheath. During the study, 50 patients were diagnosed with a fibrin sheath, and 43 had no pre-existing central venous stenosis. After FSA, 39 of the 43 patient's (91%) central systems remained patent without the need for subsequent interventions; 3 patients (7%) developed subclavian stenoses requiring repeat angioplasty and stenting; 1 patent (2.3%) developed an occlusion requiring a reintervention. Seven patients with prior central stenosis required multiple angioplasties; five required stenting of their central lesions. Every patient had follow-up fistulograms to document long-term patency. We propose that FSA is a prudent and safe procedure that may help reduce the risk of central venous stenosis from fibrin sheaths due to central venous catheters. PMID:23997555

  8. Effect of rise-time patterns on dynamics of sheath expansion during plasma immersion ion implantation

    International Nuclear Information System (INIS)

    Huang Yongxian; Tian Xiubo; Yang Shiqin; Fu Ricky; Paul, C.K.

    2007-01-01

    Plasma immersion ion implantation (PIII) has been developed as a low-cost and efficient surface modification technique of irregularly-shaped objects. The effect of six pulse waves with different rise-time patterns on the spatio-temporal evolution of plasma sheath,energy and dose of ion implantation has been simulated by particle-in-cell modeling. Statistical results may be obtained through assuming the Boltzmann distribution of electrons, and solving Poisson and Newton equations for tracing each ion in the plasma sheath. The results show that rise-time pattern has a critical influence on the evolution of plasma sheath. There exists maximum thickness difference of plasma sheath for different waveforms. The acceleration of ions is non-uniform due to the non-uniformity of electrical field strength. The maximum gradient of electrical field appears near the edge of plasma sheath. The results also show that optimization of dose and energy of incident ions may be achieved through modification of rise-time pattern. The numerical simulation of sheath expansion can be effectively used to provide a scientific basis for optimizing the PIII process. (authors)

  9. Left bundle-branch block

    DEFF Research Database (Denmark)

    Risum, Niels; Strauss, David; Sogaard, Peter

    2013-01-01

    The relationship between myocardial electrical activation by electrocardiogram (ECG) and mechanical contraction by echocardiography in left bundle-branch block (LBBB) has never been clearly demonstrated. New strict criteria for LBBB based on a fundamental understanding of physiology have recently...

  10. MAVEN EUV Modelled Data Bundle

    Data.gov (United States)

    National Aeronautics and Space Administration — This bundle contains solar irradiance spectra in 1-nm bins from 0-190 nm. The spectra are generated based upon the Flare Irradiance Spectra Model - Mars (FISM-M)...

  11. MAVEN SEP Calibrated Data Bundle

    Data.gov (United States)

    National Aeronautics and Space Administration — The maven.sep.calibrated Level 2 Science Data Bundle contains fully calibrated SEP data, as well as the raw count data from which they are derived, and ancillary...

  12. Bundling ecosystem services in Denmark

    DEFF Research Database (Denmark)

    Turner, Katrine Grace; Odgaard, Mette Vestergaard; Bøcher, Peder Klith

    2014-01-01

    We made a spatial analysis of 11 ecosystem services at a 10 km × 10 km grid scale covering most of Denmark. Our objective was to describe their spatial distribution and interactions and also to analyze whether they formed specific bundle types on a regional scale in the Danish cultural landscape....... We found clustered distribution patterns of ecosystem services across the country. There was a significant tendency for trade-offs between on the one hand cultural and regulating services and on the other provisioning services, and we also found the potential of regulating and cultural services...... to form synergies. We identified six distinct ecosystem service bundle types, indicating multiple interactions at a landscape level. The bundle types showed specialized areas of agricultural production, high provision of cultural services at the coasts, multifunctional mixed-use bundle types around urban...

  13. Line bundles and flat connections

    Indian Academy of Sciences (India)

    1School of Mathematics, Tata Institute of Fundamental Research, Homi Bhabha Road, .... sequence for complex analytic bundles, Appendix to Topological Methods ... Society of Japan 15 (1987) (Iwanami Shoten Publishers and Princeton ...

  14. Holomorphic bundles over elliptic manifolds

    International Nuclear Information System (INIS)

    Morgan, J.W.

    2000-01-01

    In this lecture we shall examine holomorphic bundles over compact elliptically fibered manifolds. We shall examine constructions of such bundles as well as (duality) relations between such bundles and other geometric objects, namely K3-surfaces and del Pezzo surfaces. We shall be dealing throughout with holomorphic principal bundles with structure group GC where G is a compact, simple (usually simply connected) Lie group and GC is the associated complex simple algebraic group. Of course, in the special case G = SU(n) and hence GC = SLn(C), we are considering holomorphic vector bundles with trivial determinant. In the other cases of classical groups, G SO(n) or G = Sympl(2n) we are considering holomorphic vector bundles with trivial determinant equipped with a non-degenerate symmetric, or skew symmetric pairing. In addition to these classical cases there are the finite number of exceptional groups. Amazingly enough, motivated by questions in physics, much interest centres around the group E8 and its subgroups. For these applications it does not suffice to consider only the classical groups. Thus, while often first doing the case of SU(n) or more generally of the classical groups, we shall extend our discussions to the general semi-simple group. Also, we shall spend a good deal of time considering elliptically fibered manifolds of the simplest type, namely, elliptic curves

  15. Beryllium brazing considerations in CANDU fuel bundle manufacture

    International Nuclear Information System (INIS)

    Harmsen, J.; Pant, A.; Lewis, B.J.; Thompson, W.T.

    2010-01-01

    'Full text:' Appendages of CANDU fuel bundle elements are currently joined to zircaloy sheaths by vacuum beryllium brazing. Ongoing environmental and workplace concerns about beryllium combined with the continuous efforts by Cameco Fuel Manufacturing in its improvement process, initiated this study to find a substitute for pure beryllium. The presentation will review the necessary functionality of brazing alloy components and short list a series of alloys with the potential to duplicate the performance of pure beryllium. Modifications to current manufacturing processes based on in-plant testing will be discussed in relation to the use of these alloys. The presentation will conclude with a summary of the progress to date and further testing expected to be necessary.

  16. Plasma sheath in non-Maxwellian plasma

    International Nuclear Information System (INIS)

    Shimizu, Takuo; Horigome, Takashi

    1992-01-01

    Reviewing many theoretical and experimental works on the electron-energy distributions (EEDF) of various plasmas, we point out that many plasmas have EEDF of non-Maxwellian in shape. Therefore, the recent treatment of plasma sheath using the Maxwell-Boltzmann distribution approximation should be improved. To do this, we have adopted Rutcher's standard distribution as a generalized form in place of the traditional Maxwellian, and found that the minimum energy of ions entering the sheath edge (Bohm's criterion) varies largely, and have also shown the variation of Debye length with the shape of EEDF. The length is the most important parameter to proceed with more detailed analysis on plasma-sheaths, and also to control them in the future. (author)

  17. Histones bundle F-actin filaments and affect actin structure.

    Directory of Open Access Journals (Sweden)

    Edna Blotnick

    Full Text Available Histones are small polycationic proteins complexed with DNA located in the cell nucleus. Upon apoptosis they are secreted from the cells and react with extracellular polyanionic compounds. Actin which is a polyanionic protein, is also secreted from necrotic cells and interacts with histones. We showed that both histone mixture (histone type III and the recombinant H2A histone bundles F-actin, increases the viscosity of the F-actin containing solution and polymerizes G-actin. The histone-actin bundles are relatively insensitive to increase of ionic strength, unlike other polycation, histatin, lysozyme, spermine and LL-37 induced F-actin bundles. The histone-actin bundles dissociate completely only in the presence of 300-400 mM NaCl. DNA, which competes with F-actin for histones, disassembles histone induced actin bundles. DNase1, which depolymerizes F- to G-actin, actively unbundles the H2A histone induced but slightly affects the histone mixture induced actin bundles. Cofilin decreases the amount of F-actin sedimented by low speed centrifugation, increases light scattering and viscosity of F-actin-histone mixture containing solutions and forms star like superstructures by copolymerizing G-actin with H2A histone. The results indicate that histones are tightly attached to F-actin by strong electrostatic and hydrophobic forces. Since both histones and F-actin are present in the sputum of patients with cystic fibrosis, therefore, the formation of the stable histone-actin bundles can contribute to the pathology of this disease by increasing the viscosity of the sputum. The actin-histone interaction in the nucleus might affect gene expression.

  18. Histones bundle F-actin filaments and affect actin structure.

    Science.gov (United States)

    Blotnick, Edna; Sol, Asaf; Muhlrad, Andras

    2017-01-01

    Histones are small polycationic proteins complexed with DNA located in the cell nucleus. Upon apoptosis they are secreted from the cells and react with extracellular polyanionic compounds. Actin which is a polyanionic protein, is also secreted from necrotic cells and interacts with histones. We showed that both histone mixture (histone type III) and the recombinant H2A histone bundles F-actin, increases the viscosity of the F-actin containing solution and polymerizes G-actin. The histone-actin bundles are relatively insensitive to increase of ionic strength, unlike other polycation, histatin, lysozyme, spermine and LL-37 induced F-actin bundles. The histone-actin bundles dissociate completely only in the presence of 300-400 mM NaCl. DNA, which competes with F-actin for histones, disassembles histone induced actin bundles. DNase1, which depolymerizes F- to G-actin, actively unbundles the H2A histone induced but slightly affects the histone mixture induced actin bundles. Cofilin decreases the amount of F-actin sedimented by low speed centrifugation, increases light scattering and viscosity of F-actin-histone mixture containing solutions and forms star like superstructures by copolymerizing G-actin with H2A histone. The results indicate that histones are tightly attached to F-actin by strong electrostatic and hydrophobic forces. Since both histones and F-actin are present in the sputum of patients with cystic fibrosis, therefore, the formation of the stable histone-actin bundles can contribute to the pathology of this disease by increasing the viscosity of the sputum. The actin-histone interaction in the nucleus might affect gene expression.

  19. Optic Nerve Sheath Meningocele: A Case Report

    Science.gov (United States)

    Halimi, E.; Wavreille, O.; Rosenberg, R.; Bouacha, I.; Lejeune, J.-P.; Defoort-Dhellemmes, S.

    2013-01-01

    Abstract Isolated optic nerve sheath meningocele is a rare affection defined as the cystic enlargement of the optic nerve sheath filled with cerebrospinal fluid. We report the case of a 39-year-old woman presenting with bilateral meningocele uncovered during a routine examination for headache complaints. A 5-year follow-up validated the lesion’s clinical and imaging stability. Magnetic resonance imaging (MRI) is an essential tool in the diagnosis of this pathology, alongside characteristic symptoms indicating that the meningocele might have progressively expanded into the orbit. In this case we present a therapeutic approach based on pathophysiological hypotheses and review of the literature. PMID:28163760

  20. Parametric investigations of target normal sheath acceleration experiments

    International Nuclear Information System (INIS)

    Zani, Alessandro; Sgattoni, Andrea; Passoni, Matteo

    2011-01-01

    One of the most important challenges related to laser-driven ion acceleration research is to actively control some important ion beam features. This is a peculiar topic in the light of future possible technological applications. In the present work we make use of one theoretical model for target normal sheath acceleration in order to reproduce recent experimental parametric studies about maximum ion energy dependencies on laser parameters. The key role played by pulse energy and intensity is enlightened. Finally the effective dependence of maximum ion energy on intensity is evaluated using a combined theoretical approach, obtained by means of an analytical and a particle-in-cell numerical investigation.

  1. Parametric investigations of target normal sheath acceleration experiments

    Science.gov (United States)

    Zani, Alessandro; Sgattoni, Andrea; Passoni, Matteo

    2011-10-01

    One of the most important challenges related to laser-driven ion acceleration research is to actively control some important ion beam features. This is a peculiar topic in the light of future possible technological applications. In the present work we make use of one theoretical model for target normal sheath acceleration in order to reproduce recent experimental parametric studies about maximum ion energy dependencies on laser parameters. The key role played by pulse energy and intensity is enlightened. Finally the effective dependence of maximum ion energy on intensity is evaluated using a combined theoretical approach, obtained by means of an analytical and a particle-in-cell numerical investigation.

  2. GPU Parallel Bundle Block Adjustment

    Directory of Open Access Journals (Sweden)

    ZHENG Maoteng

    2017-09-01

    Full Text Available To deal with massive data in photogrammetry, we introduce the GPU parallel computing technology. The preconditioned conjugate gradient and inexact Newton method are also applied to decrease the iteration times while solving the normal equation. A brand new workflow of bundle adjustment is developed to utilize GPU parallel computing technology. Our method can avoid the storage and inversion of the big normal matrix, and compute the normal matrix in real time. The proposed method can not only largely decrease the memory requirement of normal matrix, but also largely improve the efficiency of bundle adjustment. It also achieves the same accuracy as the conventional method. Preliminary experiment results show that the bundle adjustment of a dataset with about 4500 images and 9 million image points can be done in only 1.5 minutes while achieving sub-pixel accuracy.

  3. Post-irradiation examination of overheated fuel bundles

    International Nuclear Information System (INIS)

    Sears, D.F.; Primeau, M.F.; Leach, D.A.

    1995-01-01

    Post-irradiation examinations (PIE) were conducted on prototype 43-element CANDU fuel bundles that overheated during test irradiations in the NRU reactor. PIE revealed that the bundles remained physically intact, but on several elements the Zr-4 sheath collapsed into axial gaps between the pellet stack and end caps, between adjacent pellets within the stacks, and into missing pellet chips and cracks. Helium pressurization tests showed that none of the collapsed elements leaked. Hydride blisters were discovered on a few elements, but the source of the hydrogen was not linked to a breach of the cladding or end caps. These defects were attributed to primary hydriding. Microstructural changes in the fuel and cladding indicate that the cladding-was briefly exposed to temperatures in the range 600-800 o C and pressures above 11.2 MPa. The results show that Zr-4 cladding behaves in a highly ductile manner during such transient, high-temperature and high-pressure excursions. (author)

  4. Post-irradiation examination of overheated fuel bundles

    International Nuclear Information System (INIS)

    Sears, D.F.; Primeau, M.F.; Leach, D.A.

    1997-08-01

    Post-irradiation examinations (PIE) were conducted on prototype 43-element CANDU fuel bundles that overheated during test irradiations in the NRU reactor. PIE revealed that the bundles remained physically intact, but on several elements the Zr-4 sheath collapsed into axial gaps between the pellet stack and end caps, between adjacent pellets within the stacks, and into missing pellet chips and cracks. Helium pressurization tests showed that none of the collapsed elements leaked. Hydride blisters were discovered on a few elements, but the source of the hydrogen was.not linked to a breach of the cladding or end caps. These defects were attributed to primary hydriding. Microstructural changes in the fuel and cladding indicate that the cladding was briefly exposed to temperatures in the range 600-800 o C and pressures above 11.2MPa. The results show that Zr-4 cladding behaves in a highly ductile manner during such transient, high-temperature and high-pressure excursions. (author)

  5. Principal bundles the classical case

    CERN Document Server

    Sontz, Stephen Bruce

    2015-01-01

    This introductory graduate level text provides a relatively quick path to a special topic in classical differential geometry: principal bundles.  While the topic of principal bundles in differential geometry has become classic, even standard, material in the modern graduate mathematics curriculum, the unique approach taken in this text presents the material in a way that is intuitive for both students of mathematics and of physics. The goal of this book is to present important, modern geometric ideas in a form readily accessible to students and researchers in both the physics and mathematics communities, providing each with an understanding and appreciation of the language and ideas of the other.

  6. Arthroscopic sheath design and technical evaluation

    NARCIS (Netherlands)

    Tuijthof, Gabriëlle J. M.; Blankevoort, Leendert; Herder, Just L.; van Dijk, C. Niek

    2009-01-01

    The maintenance of a clear view on the operation area is essential to perform a minimally invasive procedure In arthroscopy, this is achieved by irrigating the Joint with a saline fluid that is pumped through the joint At present the arthroscopic sheaths are not designed for optimal irrigation,

  7. PDS4 Bundle Creation Governance Using BPMN

    Science.gov (United States)

    Radulescu, C.; Levoe, S. R.; Algermissen, S. S.; Rye, E. D.; Hardman, S. H.

    2015-06-01

    The AMMOS-PDS Pipeline Service (APPS) provides a Bundle Builder tool, which governs the process of creating, and ultimately generates, PDS4 bundles incrementally, as science products are being generated.

  8. Theoretical and computational studies of the sheath of a planar wall

    Science.gov (United States)

    Giraudo, Martina; Camporeale, Enrico; Delzanno, Gian Luca; Lapenta, Giovanni

    2012-03-01

    We present an investigation of the stability and nonlinear evolution of the sheath of a planar wall. We focus on the electrostatic limit. The stability analysis is conducted with a fluid model where continuity and momentum equations for the electrons and ions are coupled through Poisson's equation. The effect of electron emission from the wall is studied parametrically. Our results show that a sheath instability associated with the emitted electrons can exist. Following Ref. [1], it is interpreted as a Rayleigh-Taylor instability driven by the favorable combination of the sheath electron density gradient and electric field. Fully kinetic Particle-In-Cell (PIC) simulations will also be presented to investigate whether this instability indeed exists and to study the nonlinear effect of electron emission on the sheath profiles. The simulations will be conducted with CPIC, a new electrostatic PIC code that couples the standard PIC algorithm with strategies for generation and adaptation of the computational grid. [4pt] [1] G.L. Delzanno, ``A paradigm for the stability of the plasma sheath against fluid perturbations,'' Phys. Plasmas 18, 103508 (2011).

  9. Numerical Investigation of Characteristic of Anisotropic Thermal Conductivity of Natural Fiber Bundle with Numbered Lumens

    Directory of Open Access Journals (Sweden)

    Guan-Yu Zheng

    2014-01-01

    Full Text Available Natural fiber bundle like hemp fiber bundle usually includes many small lumens embedded in solid region; thus, it can present lower thermal conduction than that of conventional fibers. In the paper, characteristic of anisotropic transverse thermal conductivity of unidirectional natural hemp fiber bundle was numerically studied to determine the dependence of overall thermal property of the fiber bundle on that of the solid region phase. In order to efficiently predict its thermal property, the fiber bundle was embedded into an imaginary matrix to form a unit composite cell consisting of the matrix and the fiber bundle. Equally, another unit composite cell including an equivalent solid fiber was established to present the homogenization of the fiber bundle. Next, finite element thermal analysis implemented by ABAQUS was conducted in the two established composite cells by applying proper thermal boundary conditions along the boundary of unit cell, and influences of the solid region phase and the equivalent solid fiber on the composites were investigated, respectively. Subsequently, an optional relationship of thermal conductivities of the natural fiber bundle and the solid region was obtained by curve fitting technique. Finally, numerical results from the obtained fitted curves were compared with the analytic Hasselman-Johnson’s results and others to verify the present numerical model.

  10. Exploring Bundling Theory with Geometry

    Science.gov (United States)

    Eckalbar, John C.

    2006-01-01

    The author shows how instructors might successfully introduce students in principles and intermediate microeconomic theory classes to the topic of bundling (i.e., the selling of two or more goods as a package, rather than separately). It is surprising how much students can learn using only the tools of high school geometry. To be specific, one can…

  11. Episodic payments (bundling): PART I.

    Science.gov (United States)

    Jacofsky, D J

    2017-10-01

    Episodic, or bundled payments, is a concept now familiar to most in the healthcare arena, but the models are often misunderstood. Under a traditional fee-for-service model, each provider bills separately for their services which creates financial incentives to maximise volumes. Under a bundled payment, a single entity, often referred to as a convener (maybe the hospital, the physician group, or a third party) assumes the risk through a payer contract for all services provided within a defined episode of care, and receives a single (bundled) payment for all services provided for that episode. The time frame around the intervention is variable, but defined in advance, as are included and excluded costs. Timing of the actual payment in a bundle may either be before the episode occurs (prospective payment model), or after the end of the episode through a reconciliation (retrospective payment model). In either case, the defined costs over the defined time frame are borne by the convener. Cite this article: Bone Joint J 2017;99-B:1280-5. ©2017 The British Editorial Society of Bone & Joint Surgery.

  12. Deformation quantization of principal fibre bundles

    International Nuclear Information System (INIS)

    Weiss, S.

    2007-01-01

    Deformation quantization is an algebraic but still geometrical way to define noncommutative spacetimes. In order to investigate corresponding gauge theories on such spaces, the geometrical formulation in terms of principal fibre bundles yields the appropriate framework. In this talk I will explain what should be understood by a deformation quantization of principal fibre bundles and how associated vector bundles arise in this context. (author)

  13. Output commitment through product bundling : Experimental evidence

    NARCIS (Netherlands)

    Hinloopen, Jeroen; Mueller, Wieland; Normann, Hans-Theo

    We analyze the impact of product bundling in experimental markets. One firm has monopoly power in a first market but competes with another firm la Cournot in a second market. We compare treatments where the multi-product firm (i) always bundles, (ii) never bundles, and (iii) chooses whether to

  14. Dimensional measurements and eddy currents control of the sheath integrity for a set of irradiated candu fuel elements

    International Nuclear Information System (INIS)

    Gheorghe, G.; Man, I.

    2015-01-01

    During irradiation in the nuclear reactor, fuel elements undergo dimensional and structural changes, and changes of sheath surface condition as well, which can lead to damages and even loss of integrity. This paper presents the results of dimensional measurements and of examination technique with eddy currents for three fuel elements of an irradiated CANDU fuel bundle. One of the fuel elements (FE), which is studied in detail, presented a crack about 40 mm long. The purpose of these nondestructive examination techniques is to determine those parameters that characterize the behavior and performance of nuclear fuel operation. This paper contains images of defects and interpretations of the causes of their occurrence. (authors)

  15. Tumor targeted delivery of doxorubicin in malignant peripheral nerve sheath tumors.

    Directory of Open Access Journals (Sweden)

    A B Madhankumar

    Full Text Available Peripheral nerve sheath tumors are benign tumors that have the potential to transform into malignant peripheral nerve sheath tumors (MPNSTs. Interleukin-13 receptor alpha 2 (IL13Rα2 is a cancer associated receptor expressed in glioblastoma and other invasive cancers. We analyzed IL13Rα2 expression in several MPNST cell lines including the STS26T cell line, as well as in several peripheral nerve sheath tumors to utilize the IL13Rα2 receptor as a target for therapy. In our studies, we demonstrated the selective expression of IL13Rα2 in several peripheral nerve sheath tumors by immunohistochemistry (IHC and immunoblots. We established a sciatic nerve MPNST mouse model in NIH III nude mice using a luciferase transfected STS26T MPNST cell line. Similarly, analysis of the mouse sciatic nerves after tumor induction revealed significant expression of IL13Rα2 by IHC when compared to a normal sciatic nerve. IL13 conjugated liposomal doxorubicin was formulated and shown to bind and internalized in the MPNST cell culture model demonstrating cytotoxic effect. Our subsequent in vivo investigation in the STS26T MPNST sciatic nerve tumor model indicated that IL13 conjugated liposomal doxorubicin (IL13LIPDXR was more effective in inhibiting tumor progression compared to unconjugated liposomal doxorubicin (LIPDXR. This further supports that IL13 receptor targeted nanoliposomes is a potential approach for treating MPNSTs.

  16. Higher order jet prolongations type gauge natural bundles over vector bundles

    Directory of Open Access Journals (Sweden)

    Jan Kurek

    2004-05-01

    Full Text Available Let $rgeq 3$ and $mgeq 2$ be natural numbers and $E$ be a vector bundle with $m$-dimensional basis. We find all gauge natural bundles ``similar" to the $r$-jet prolongation bundle $J^rE$ of $E$. We also find all gauge natural bundles ``similar" to the vector $r$-tangent bundle $(J^r_{fl}(E,R_0^*$ of $E$.

  17. Stress generation by myosin minifilaments in actin bundles

    International Nuclear Information System (INIS)

    Dasanayake, Nilushi L; Carlsson, Anders E

    2013-01-01

    Forces and stresses generated by the action of myosin minifilaments are analyzed in idealized computer-generated actin bundles, and compared to results for isotropic actin networks. The bundles are generated as random collections of actin filaments in two dimensions with constrained orientations, crosslinked and attached to two fixed walls. Myosin minifilaments are placed on actin filament pairs and allowed to move and deform the network so that it exerts forces on the walls. The vast majority of simulation runs end with contractile minifilament stress, because minifilaments rotate into energetically stable contractile configurations. This process is aided by the bending and stretching of actin filaments, which accomodate minifilament rotation. Stresses for bundles are greater than those for isotropic networks, and antiparallel filaments generate more tension than parallel filaments. The forces transmitted by the actin network to the walls of the simulation cell often exceed the tension in the minifilament itself. (paper)

  18. Engineering biomimetic hair bundle sensors for underwater sensing applications

    Science.gov (United States)

    Kottapalli, Ajay Giri Prakash; Asadnia, Mohsen; Karavitaki, K. Domenica; Warkiani, Majid Ebrahimi; Miao, Jianmin; Corey, David P.; Triantafyllou, Michael

    2018-05-01

    We present the fabrication of an artificial MEMS hair bundle sensor designed to approximate the structural and functional principles of the flow-sensing bundles found in fish neuromast hair cells. The sensor consists of micro-pillars of graded height connected with piezoelectric nanofiber "tip-links" and encapsulated by a hydrogel cupula-like structure. Fluid drag force actuates the hydrogel cupula and deflects the micro-pillar bundle, stretching the nanofibers and generating electric charges. These biomimetic sensors achieve an ultrahigh sensitivity of 0.286 mV/(mm/s) and an extremely low threshold detection limit of 8.24 µm/s. A complete version of this paper has been published [1].

  19. Post-irradiation examination of CANDU fuel bundles fuelled with (Th, Pu)O2

    International Nuclear Information System (INIS)

    Karam, M.; Dimayuga, F.C.; Montin, J.

    2010-01-01

    AECL has extensive experience with thoria-based fuel irradiations as part of an ongoing R&D program on thorium within the Advanced Fuel Cycles Program. The BDL-422 experiment was one component of the thorium program that involved the fabrication and irradiation testing of six Bruce-type bundles fuelled with (Th, Pu)O 2 pellets. The fuel was manufactured in the Recycle Fuel Fabrication Laboratories (RFFL) at Chalk River allowing AECL to gain valuable experience in fabrication and handling of thoria fuel. The fuel pellets contained 86.05 wt.% Th and 1.53 wt.% Pu in (Th, Pu)O 2 . The objectives of the BDL-422 experiment were to demonstrate the ability of 37-element geometry (Th, Pu)O 2 fuel bundles to operate to high burnups up to 1000 MWh/kgHE (42 MWd/kgHE), and to examine the (Th, Pu)O 2 fuel performance. This paper describes the post-irradiation examination (PIE) results of BDL-422 fuel bundles irradiated to burnups up to 856 MWh/kgHE (36 MWd/kgHE), with power ratings ranging from 52 to 67 kW/m. PIE results for the high burnup bundles (>1000 MWh/kgHE) are being analyzed and will be reported at a later date. The (Th, Pu)O 2 fuel performance characteristics were superior to UO 2 fuel irradiated under similar conditions. Minimal grain growth was observed and was accompanied by benign fission gas release and sheath strain. Other fuel performance parameters, such as sheath oxidation and hydrogen distribution, are also discussed. (author)

  20. Co-Higgs bundles on P^1

    OpenAIRE

    Rayan, Steven

    2010-01-01

    Co-Higgs bundles are Higgs bundles in the sense of Simpson, but with Higgs fields that take values in the tangent bundle instead of the cotangent bundle. Given a vector bundle on P^1, we find necessary and sufficient conditions on its Grothendieck splitting for it to admit a stable Higgs field. We characterize the rank-2, odd-degree moduli space as a universal elliptic curve with a globally-defined equation. For ranks r=2,3,4, we explicitly verify the conjectural Betti numbers emerging from t...

  1. Boiling heat transfer on horizontal tube bundles

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    Nucleate boiling heat transfer characteristics for a tube in a bundle differ from that for a single tube in a pool and this difference is known as 'tube bundle effect.' There exist two bundle effects, positive and negative. The positive bundle effect enhances heat transfer due to convective flow induced by rising bubbles generated from the lower tubes, while the negative bundle effect deteriorates heat transfer due to vapor blanketing caused by accumulation of bubbles. Staggered tube bundles tested and found that the upper tubes in bundles have higher heat transfer coefficients than the lower tubes. The effects of various parameters such as pressure, tube geometry and oil contamination on heat transfer have been examined. Some workers attempted to clarify the mechanism of occurrence of 'bundle effect' by testing tube arrangements of small scale. All reported only enhancement in heat transfer but results showed the symptom of heat transfer deterioration at higher heat fluxes. As mentioned above, it has not been clarified so far even whether the 'tube bundle effect' should serve as enhancement or deterioration of heat transfer in nucleate boiling. In this study, experiments are performed in detail by using bundles of small scale, and effects of heat flux distribution, pressure and tube location are clarified. Furthermore, some consideration on the mechanisms of occurrence of 'tube bundle effect' is made and a method for prediction of heat transfer rate is proposed

  2. Fluid structure interaction in tube bundles

    International Nuclear Information System (INIS)

    Brochard, D.; Jedrzejewski, F.; Gibert, R.J.

    1995-01-01

    A lot of industrial components contain tube bundles immersed in a fluid. The mechanical analysis of such systems requires the study of the fluid structure interaction in the tube bundle. Simplified methods, based on homogenization methods, have been developed to analyse such phenomenon and have been validated through experimental results. Generally, these methods consider only the fluid motion in a plan normal to the bundle axis. This paper will analyse, in a first part, the fluid structure interaction in a tube bundle through a 2D finite element model representing the bundle cross section. The influence of various parameters like the bundle size, and the bundle confinement will be studied. These results will be then compared with results from homogenization methods. Finally, the influence of the 3D fluid motion will be investigated, in using simplified methods. (authors). 11 refs., 12 figs., 2 tabs

  3. Development of CANFLEX fuel bundle

    International Nuclear Information System (INIS)

    Suk, Ho Chun; Hwang, Woan; Jeong, Young Hwan

    1991-12-01

    This research project is underway in cooperation with AECL to develop the CANDU advanced fuel bundle(so-called CANFLEX) which can enhance reactor safety and fuel economy in comparison with the current CANDU fuel and which can be used with natural uranium, slightly enriched uranium and other advanced fuel cycle. As the final schedule, the advanced fuel will be verified by carrying out a large scale demonstration of the bundle irradiation in a commercial CANDU reactors for 1996 and 1997, and consequently will be used in the existing and future reactors in Korea. The research activities during this year include the basic design of CANFLEX fuel with slightly enriched uranium(CANFLEX-SEU), with emphasis on the extension of fuel operation limit. Based on this basic design, CANFLEX fuel was mocked up. Out-of-pile hydraulic scoping tests were conducted with the fuel. (Author)

  4. Modelling disassembled fuel bundles using CATHENA MOD-3.5a under LOCA/LOECC conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lei, Q M; Sanderson, D B; Dutton, R [Atomic Energy of Canada Ltd., Pinawa, MB (Canada). Whiteshell Labs.

    1996-12-31

    CATHENA MOD-3.5a is a multipurpose thermalhydraulic computer code developed primarily to analyse postulated loss-of-coolant scenarios for CANDU nuclear reactors. The code contains a generalized heat transfer package that enables it to model the behaviour of a fuel channel in great detail. Throughout the development of the CATHENA code, considerable effort has been devoted to evaluating, validating and documenting its overall capability as a design and safety assessment tool. Specific attention has focused on its ability to predict fuel channel behaviour under postulated accident conditions. This paper describes an investigation of CATHENA`s ability to predict the thermal-chemical responses of a fuel channel in which the 37-element bundles were assumed to disassemble and rearrange into a closed-packed stack of elements at the bottom of the pressure tube. A representative disassembled bundle geometry was modelled during a simulated loss-of-coolant accident scenario using CATHENA MOD-3.5a/Rev 0, with superheated steam being the only coolant available. Thermal conduction in the radial and circumferential directions was calculated for individual fuel elements, the pressure tube, and the calandria tube. Radiation view factors for the intact and disassembled bundle geometries were calculated using a CATHENA utility program. Inter-element metal-to-metal contact was accounted for using the CATHENA solid-solid contact model. An offset pressure-tube configuration, representing a partially sagged pressure tube, and the effect of steam starvation on the exothermic zirconium-steam reaction, were included in the CATHENA model. The CATHENA-predicted results show a dramatic suppression of heat generation from the zirconium-steam reaction when bundle disassembly is initiated. The predicted results show a smaller temperature increase in the fuel sheaths and the pressure tube for the disassembled bundle geometry, compared to the temperature excursion for the intact bundle. (author

  5. Competitive nonlinear pricing and bundling

    OpenAIRE

    Armstrong, Mark; Vickers, John

    2006-01-01

    We examine the impact of multiproduct nonlinear pricing on profit, consumer surplus and welfare in a duopoly. When consumers buy all their products from one firm (the one-stop shopping model), nonlinear pricing leads to higher profit and welfare, but often lower consumer surplus, than linear pricing. By contrast, in a unit-demand model where consumers may buy one product from one firm and another product from another firm, bundling generally acts to reduce profit and welfare and to boost cons...

  6. Radio frequency sheaths in an oblique magnetic field

    International Nuclear Information System (INIS)

    Myra, J. R.; D'Ippolito, D. A.

    2015-01-01

    The physics of radio-frequency (rf) sheaths near a conducting surface is studied for plasmas immersed in a magnetic field that makes an oblique angle θ with the surface. A set of one-dimensional equations is developed that describes the dynamics of the time-dependent magnetic presheath and non-neutral Debye sheath. The model employs Maxwell-Boltzmann electrons, and the magnetization and mobility of the ions is determined by the magnetic field strength, and wave frequency, respectively. The angle θ, assumed to be large enough to insure an electron-poor sheath, is otherwise arbitrary. Concentrating on the ion-cyclotron range of frequencies, the equations are solved numerically to obtain the rectified (dc) voltage, the rf voltage across the sheath, and the rf current flowing through the sheath. As an application of this model, the sheath voltage-current relation is used to obtain the rf sheath impedance, which in turn gives an rf sheath boundary condition for the electric field at the sheath-plasma interface that can be used in rf wave codes. In general, the impedance has both resistive and capacitive contributions, and generalizes previous sheath boundary condition models. The resistive part contributes to parasitic power dissipation at the wall

  7. The Analysis of SBWR Critical Power Bundle Using Cobrag Code

    Directory of Open Access Journals (Sweden)

    Yohannes Sardjono

    2013-03-01

    Full Text Available The coolant mechanism of SBWR is similar with the Dodewaard Nuclear Power Plant (NPP in the Netherlands that first went critical in 1968. The similarity of both NPP is cooled by natural convection system. These coolant concept is very related with same parameters on fuel bundle design especially fuel bundle length, core pressure drop and core flow rate as well as critical power bundle. The analysis was carried out by using COBRAG computer code. COBRAG computer code is GE Company proprietary. Basically COBRAG computer code is a tool to solve compressible three-dimensional, two fluid, three field equations for two phase flow. The three fields are the vapor field, the continuous liquid field, and the liquid drop field. This code has been applied to analyses model flow and heat transfer within the reactor core. This volume describes the finitevolume equations and the numerical solution methods used to solve these equations. This analysis of same parameters has been done i.e.; inlet sub cooling 20 BTU/lbm and 40 BTU/lbm, 1000 psi pressure and R-factor is 1.038, mass flux are 0.5 Mlb/hr.ft2, 0.75 Mlb/hr.ft2, 1.00 Mlb/hr.ft2 and 1.25 Mlb/hr.ft2. Those conditions based on history operation of some type of the cell fuel bundle line at GE Nuclear Energy. According to the results, it can be concluded that SBWR critical power bundle is 10.5 % less than current BWR critical power bundle with length reduction of 12 ft to 9 ft.

  8. Multicell slug flow heat transfer analysis of finite LMFBR bundles

    International Nuclear Information System (INIS)

    Yeung, M.K.; Wolf, L.

    1978-12-01

    An analytical two-dimensional, multi-region, multi-cell technique has been developed for the thermal analysis of LMFBR rod bundles. Local temperature fields of various unit cells were obtained for 7, 19, and 37-rod bundles of different geometries and power distributions. The validity of the technique has been verified by its excellent agreement with the THTB calculational result. By comparing the calculated fully-developed circumferential clad temperature distribution with those of the experimental measurements, an axial correction factor has been derived to account for the entrance effect for practical considerations. Moreover, the knowledge of the local temperature field of the rod bundle leads to the determination of the effective mixing lengths L/sub ij/ for adjacent subchannels of various geometries. It was shown that the implementation of the accurately determined L/sub ij/ into COBRA-IIIC calculations has fairly significant effects on intersubchannel mixing. In addition, a scheme has been proposed to couple the 2-D distributed and lumped parameter calculation by COBRA-IIIC such that the entrance effect can be implanted into the distributed parameter analysis. The technique has demonstrated its applicability for a 7-rod bundle and the results of calculation were compared to those of three-dimensional analyses and experimental measurements

  9. Nondestructive testing of metallic sheath for internally cooled superconductor

    International Nuclear Information System (INIS)

    McClung, R.W.; Cook, K.V.; Dodd, C.V.; Smith, J.H.

    1983-01-01

    For quality assurance in the Oak Ridge National Laboratory Large Coil Program, we developed ultrasonic and eddy-current techniques to examine the JBK-75 alloy sheath for superconducting cable for a large magnet. Ultrasound was used to examine the strip before forming into the sheath, and eddy currents were used to examine the seam weld after the sheath had been formed around the cable

  10. Characterization of midrib vascular bundles of selected medicinal species in Rubiaceae

    Science.gov (United States)

    Nurul-Syahirah, M.; Noraini, T.; Latiff, A.

    2016-11-01

    An anatomical study was carried out on mature leaves of five selected medicinal species of Rubiaceae from Peninsular Malaysia. The chosen medicinal species were Aidia densiflora, Aidia racemosa, Chasallia chartacea, Hedyotis auricularia and Ixora grandifolia. The objective of this study is to determine the taxonomic value of midrib anatomical characteristics. Leaves samples were collected from Taman Paku Pakis, Universiti Kebangsaan Malaysia, Bangi, Selangor and Kledang Saiong Forest Reserve, Perak, Malaysia. Leaves samples then were fixed in spirit and acetic acid (3:1), the midrib parts then were sectioned using sliding microtome, cleared using Clorox, stained in Safranin and Alcian blue, mounted in Euparal and were observed under light microscope. Findings in this study have shown all species have collateral bundles. The midrib vascular bundles characteristics that can be used as tool to differentiate between species or genus are vascular bundles system (opened or closed), shape and arrangement of main vascular bundles, presence of both additional and medullary vascular bundles, position of additional vascular bundles, shape of medullary vascular bundles, presence of sclerenchyma cells ensheathed the vascular bundles. As a conclusion, midrib anatomical characteristics can be used to identify and discriminate medicinal plants species studied in the Rubiaceae.

  11. Expansion and Polarity Sorting in Microtubule-Dynein Bundles(WHAT IS LIFE? THE NEXT 100 YEARS OF YUKAWA'S DREAM)

    OpenAIRE

    Assaf, ZEMEL; Alex, MOGILNER; Department of Neurobiology, Physiology and Behavior, University of California; Department of Neurobiology, Physiology and Behavior, University of California

    2008-01-01

    Interactions of multiple molecular motors with dynamic polymers, such as actin and microtubules, form the basis for many processes in the cell cytoskeleton. One example is the active 'sorting' of microtubule bundles by dynein molecular motors into aster-like arrays of microtubules; in these bundles dynein motors cross-link and slide neighboring microtubules apart. A number of models have been suggested to quantify the active dynamics of cross-linked bundles of polar filaments. In the case of ...

  12. Annihilation model of the Tormac sheath

    International Nuclear Information System (INIS)

    Hammer, J.H.

    1979-02-01

    A one-dimensional, steady state fluid model is developed to describe the boundary layer between plasma and magnetic field that occurs in the Tormac sheath. Similar systems which may be treatable by the same model are tokamaks with divertors and reversed field mirrors. The model includes transport across the magnetic field as well as mirror losses along the field, the latter being represented as annihilation terms in the one-dimensional equations. The model equations are derived from the two-dimensional, time dependent hierarchy of equations generated by taking velocity moments of the kinetic equation including collisions

  13. ICRF antenna Faraday shield plasma sheath model

    International Nuclear Information System (INIS)

    Whealton, J.H.; Ryan, P.M.; Raridon, R.J.

    1990-01-01

    A two-dimensional nonlinear formulation that explicitly considers the plasma edge near a Faraday shield in a self-consistent manner is used in the modeling of the ion motion for a Faraday shield concept and model suggested by Perkins. Two models are considered that may provide significant insight into the generation of impurities for ion cyclotron resonance heating (ICRH) antennas. In one of these models a significant sheath periodically forms next to the Faraday screen, with ion acoustic waves heating the ions in the plasma. (orig.)

  14. Effect of power variations across a fuel bundle and within a fuel element on fuel centerline temperature in PHWR bundles in uncrept and crept pressure tubes

    International Nuclear Information System (INIS)

    Onder, E.N.; Roubtsov, D.; Rao, Y.F.; Wilhelm, B.

    2017-01-01

    Highlights: • Pressure tube creep effect on fuel pin power and temperatures was investigated. • Noticeable effects were observed for 5.1% crept pressure tube. • Bundle eccentricity effect on power variations was insignificant for uncrept channels. • Difference of 112 °C was observed between top & bottom elements in 5.1% crept channel. • Not discernible fission gas release was expected with temperature difference of 112 °C. - Abstract: The neutron flux and fission power profiles through a fuel bundle and across a fuel element are important aspects of nuclear fuel analysis in multi-scale/multi-physics modelling of Pressurized Heavy Water Reactors (PHWRs) with advanced fuel bundles. Fuel channels in many existing PHWRs are horizontal. With ageing, pressure tubes creep and fuel bundles in these pressure tubes are eccentrically located, which results in an asymmetric coolant flow distribution between the top and bottom of the fuel bundles. The diametral change of the pressure tube due to creep is not constant along the fuel channel; it reaches a maximum in the vicinity of the maximum neutron flux location. The cross-sectional asymmetric positioning of fuel bundles in a crept pressure tube contributes to an asymmetric power distribution within a ring of fuel elements. Modern reactor physics lattice codes (such as WIMS-AECL) are capable of predicting the details of power distribution from basic principles. Thermalhydraulics subchannel codes (such as ASSERT-PV) use models to describe inhomogeneous power distribution within and across fuel elements (e.g., flux tilt model, different powers in different ring elements, or radial power profiles). In this work, physics and thermalhydraulics codes are applied to quantify the effect of eccentricity of a fuel bundle on power variations across it and within a fuel element, and ultimately on the fuel temperature distribution and fuel centerline temperature, which is one of the indicators of fuel performance under normal

  15. Microtubule bundling plays a role in ethylene-mediated cortical microtubule reorientation in etiolated Arabidopsis hypocotyls.

    Science.gov (United States)

    Ma, Qianqian; Sun, Jingbo; Mao, Tonglin

    2016-05-15

    The gaseous hormone ethylene is known to regulate plant growth under etiolated conditions (the 'triple response'). Although organization of cortical microtubules is essential for cell elongation, the underlying mechanisms that regulate microtubule organization by hormone signaling, including ethylene, are ambiguous. In the present study, we demonstrate that ethylene signaling participates in regulation of cortical microtubule reorientation. In particular, regulation of microtubule bundling is important for this process in etiolated hypocotyls. Time-lapse analysis indicated that selective stabilization of microtubule-bundling structures formed in various arrays is related to ethylene-mediated microtubule orientation. Bundling events and bundle growth lifetimes were significantly increased in oblique and longitudinal arrays, but decreased in transverse arrays in wild-type cells in response to ethylene. However, the effects of ethylene on microtubule bundling were partially suppressed in a microtubule-bundling protein WDL5 knockout mutant (wdl5-1). This study suggests that modulation of microtubule bundles that have formed in certain orientations plays a role in reorienting microtubule arrays in response to ethylene-mediated etiolated hypocotyl cell elongation. © 2016. Published by The Company of Biologists Ltd.

  16. The characteristics of RF modulated plasma boundary sheaths: An analysis of the standard sheath model

    Science.gov (United States)

    Naggary, Schabnam; Brinkmann, Ralf Peter

    2015-09-01

    The characteristics of radio frequency (RF) modulated plasma boundary sheaths are studied on the basis of the so-called ``standard sheath model.'' This model assumes that the applied radio frequency ωRF is larger than the plasma frequency of the ions but smaller than that of the electrons. It comprises a phase-averaged ion model - consisting of an equation of continuity (with ionization neglected) and an equation of motion (with collisional ion-neutral interaction taken into account) - a phase-resolved electron model - consisting of an equation of continuity and the assumption of Boltzmann equilibrium -, and Poisson's equation for the electrical field. Previous investigations have studied the standard sheath model under additional approximations, most notably the assumption of a step-like electron front. This contribution presents an investigation and parameter study of the standard sheath model which avoids any further assumptions. The resulting density profiles and overall charge-voltage characteristics are compared with those of the step-model based theories. The authors gratefully acknowledge Efe Kemaneci for helpful comments and fruitful discussions.

  17. Job Management and Task Bundling

    Science.gov (United States)

    Berkowitz, Evan; Jansen, Gustav R.; McElvain, Kenneth; Walker-Loud, André

    2018-03-01

    High Performance Computing is often performed on scarce and shared computing resources. To ensure computers are used to their full capacity, administrators often incentivize large workloads that are not possible on smaller systems. Measurements in Lattice QCD frequently do not scale to machine-size workloads. By bundling tasks together we can create large jobs suitable for gigantic partitions. We discuss METAQ and mpi_jm, software developed to dynamically group computational tasks together, that can intelligently backfill to consume idle time without substantial changes to users' current workflows or executables.

  18. Job Management and Task Bundling

    Directory of Open Access Journals (Sweden)

    Berkowitz Evan

    2018-01-01

    Full Text Available High Performance Computing is often performed on scarce and shared computing resources. To ensure computers are used to their full capacity, administrators often incentivize large workloads that are not possible on smaller systems. Measurements in Lattice QCD frequently do not scale to machine-size workloads. By bundling tasks together we can create large jobs suitable for gigantic partitions. We discuss METAQ and mpi_jm, software developed to dynamically group computational tasks together, that can intelligently backfill to consume idle time without substantial changes to users’ current workflows or executables.

  19. Fuel bundle for nuclear reactor

    International Nuclear Information System (INIS)

    Long, J.W.; Flora, B.S.; Ford, K.L.

    1977-01-01

    The invention concerns a new, simple and inexpensive system for assembling and dismantling a nuclear reactor fuel bundle. Several fuel rods are fitted in parallel rows between two retaining plates which secure the fuel rods in position and which are maintained in an assembled position by means of several stays fixed to the two end plates. The invention particularly refers to an improved apparatus for fixing the stays to the upper plate by using locking fittings secured to rotating sleeves which are applied against this plate [fr

  20. Reduction of symplectic principal R-bundles

    International Nuclear Information System (INIS)

    Lacirasella, Ignazio; Marrero, Juan Carlos; Padrón, Edith

    2012-01-01

    We describe a reduction process for symplectic principal R-bundles in the presence of a momentum map. These types of structures play an important role in the geometric formulation of non-autonomous Hamiltonian systems. We apply this procedure to the standard symplectic principal R-bundle associated with a fibration π:M→R. Moreover, we show a reduction process for non-autonomous Hamiltonian systems on symplectic principal R-bundles. We apply these reduction processes to several examples. (paper)

  1. ACM Bundles on Del Pezzo surfaces

    Directory of Open Access Journals (Sweden)

    Joan Pons-Llopis

    2009-11-01

    Full Text Available ACM rank 1 bundles on del Pezzo surfaces are classified in terms of the rational normal curves that they contain. A complete list of ACM line bundles is provided. Moreover, for any del Pezzo surface X of degree less or equal than six and for any n ≥ 2 we construct a family of dimension ≥ n − 1 of non-isomorphic simple ACM bundles of rank n on X.

  2. Bundling and mergers in energy markets

    International Nuclear Information System (INIS)

    Granier, Laurent; Podesta, Marion

    2010-01-01

    Does bundling trigger mergers in energy industries? We observe mergers between firms belonging to various energy markets, for instance between gas and electricity providers. These mergers enable firms to bundle. We consider two horizontally differentiated markets. In this framework, we show that bundling strategies in energy markets create incentives to form multi-market firms in order to supply bi-energy packages. Moreover, we find that this type of merger is detrimental to social welfare. (author)

  3. Entropy for frame bundle systems and Grassmann bundle systems induced by a diffeomorphism

    Institute of Scientific and Technical Information of China (English)

    SUN; Weniang(孙文祥)

    2002-01-01

    ALiao hyperbolic diffeomorphism has equal measure entropy and topological entropy to that ofits induced systems on frame bundles and Grassmann bundles. This solves a problem Liao posed in 1996 forLiao hyperbolic diffeomorphisms.

  4. A contribution to understanding the structure of amphivasal secondary bundles in monocotyledons

    Directory of Open Access Journals (Sweden)

    Joanna Jura-Morawiec

    2014-04-01

    Full Text Available Secondary growth of monocotyledonous plants is connected with the activity of the monocot cambium that accumulates most of the derivatives inner to the cambial cylinder. These derivatives differentiate into (a secondary bundles with the amphivasal arrangement, i.e. xylem composed of tracheids surrounds the phloem cells and (b the parenchymatous secondary conjunctive tissue in which the bundles are embedded. The amphivasal secondary bundles differ in the arrangement of xylem cells as visible on single cross sections through the secondary body of the monocots. Apart from the bundles with typical ring of tracheids also the bundles where tracheids do not quite surround the phloem are present. We aimed to elucidate the cross sectional anatomy of the amphivasal secondary bundles with the use of the serial sectioning method which allowed us to follow very precisely the bundle structure along its length. The studies were carried out with the samples of secondary tissues collected from the stem of Dracaena draco L. growing in the greenhouses of the Polish Academy of Sciences Botanical Garden – CBDC in Powsin and the Adam Mickiewicz University Botanical Garden. The material was fixed in a mixture of glycerol and ethanol (1:1; v/v, dehydrated stepwise with graded ethanol series and finally embedded in epon resin. Afterwards, the material was sectioned with microtome into continuous series of thin (3 μm sections, stained with PAS/toluidine blue and examined under the light microscope. The results, described in details in Jura‑Morawiec & Wiland-Szymańska (2014, revealed novel facts about tracheids arrangement. Each amphivasal bundle is composed of sectors where tracheids form a ring as well as of such where tracheids are separated by vascular parenchyma cells. We hypothesize that strands of vascular parenchyma cells locally separating the tracheids enable radial transport of assimilates from sieve elements of the bundle towards the sink tissues, e

  5. Hedgehog signaling is required for formation of the notochord sheath and patterning of nuclei pulposi within the intervertebral discs.

    Science.gov (United States)

    Choi, Kyung-Suk; Harfe, Brian D

    2011-06-07

    The vertebrae notochord is a transient rod-like structure that produces secreted factors that are responsible for patterning surrounding tissues. During later mouse embryogenesis, the notochord gives rise to the middle part of the intervertebral disc, called the nucleus pulposus. Currently, very little is known about the molecular mechanisms responsible for forming the intervertebral discs. Here we demonstrate that hedgehog signaling is required for formation of the intervertebral discs. Removal of hedgehog signaling in the notochord and nearby floorplate resulted in the formation of an aberrant notochord sheath that normally surrounds this structure. In the absence of the notochord sheath, small nuclei pulposi were formed, with most notochord cells dispersed throughout the vertebral bodies during embryogenesis. Our data suggest that the formation of the notochord sheath requires hedgehog signaling and that the sheath is essential for maintaining the rod-like structure of the notochord during early embryonic development. As notochord cells form nuclei pulposi, we propose that the notochord sheath functions as a "wrapper" around the notochord to constrain these cells along the vertebral column.

  6. Hydraulic characteristics of HANARO fuel bundles

    Energy Technology Data Exchange (ETDEWEB)

    Cho, S.; Chung, H. J.; Chun, S. Y.; Yang, S. K.; Chung, M. K. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    This paper presents the hydraulic characteristics measured by using LDV (Laser Doppler Velocimetry) in subchannels of HANARO, KAERI research reactor, fuel bundle. The fuel bundle consists of 18 axially finned rods with 3 spacer grids, which are arranged in cylindrical configuration. The effects of the spacer grids on the turbulent flow were investigated by the experimental results. Pressure drops for each component of the fuel bundle were measured, and the friction factors of fuel bundle and loss coefficients for the spacer grids were estimated from the measured pressure drops. Implications regarding the turbulent thermal mixing were discussed. Vibration test results measured by using laser vibrometer were presented. 9 refs., 12 figs. (Author)

  7. Hydraulic characteristics of HANARO fuel bundles

    Energy Technology Data Exchange (ETDEWEB)

    Cho, S; Chung, H J; Chun, S Y; Yang, S K; Chung, M K [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    This paper presents the hydraulic characteristics measured by using LDV (Laser Doppler Velocimetry) in subchannels of HANARO, KAERI research reactor, fuel bundle. The fuel bundle consists of 18 axially finned rods with 3 spacer grids, which are arranged in cylindrical configuration. The effects of the spacer grids on the turbulent flow were investigated by the experimental results. Pressure drops for each component of the fuel bundle were measured, and the friction factors of fuel bundle and loss coefficients for the spacer grids were estimated from the measured pressure drops. Implications regarding the turbulent thermal mixing were discussed. Vibration test results measured by using laser vibrometer were presented. 9 refs., 12 figs. (Author)

  8. Cotangent bundle approach to noninertial frames

    International Nuclear Information System (INIS)

    DeFacio, B.; Retzloff, D.

    1980-01-01

    The most general possible noninertial acceleration in special relativity is formulated with differential forms in the cotangent bundle. We show that the Lie derivative plays the same role in the cotangent bundle that the covariant derivative plays in the tangent bundle. We also show that a cotangent bundle analog of Fermi--Walker transport can be based upon the, ''cotangent-geodesic'' equation, L/sub u/ω=0. This gives a generalization of the work by Kiehn on classical Hamiltonian mechanics to special relativity

  9. The ion polytropic coefficient in a collisionless sheath containing hot ions

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Binbin; Xiang, Nong, E-mail: xiangn@ipp.ac.cn; Ou, Jing [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Center for Magnetic Fusion Theory, Chinese Academy of Sciences, Hefei 230031 (China)

    2016-08-15

    The fluid approach has been widely used to study plasma sheath dynamics. For a sheath containing hot ions whose temperature is greater than the electron's, how to truncate the fluid hierarchy chain equations while retaining to the fullest extent of the kinetic effects is always a difficult problem. In this paper, a one-dimensional, collisionless sheath containing hot ions is studied via particle-in-cell simulations. By analyzing the ion energy equation and taking the kinetic effects into account, we have shown that the ion polytropic coefficient in the vicinity of the sheath edge is approximately constant so that the state equation with the modified polytropic coefficient can be used to close the hierarchy chain of the ion fluid equations. The value of the polytropic coefficient strongly depends on the hot ion temperature and its concentration in the plasma. The semi-analytical model is given to interpret the simulation results. As an application, the kinetic effects on the ion saturation current density in the probe theory are discussed.

  10. The plasma-sheath boundary region

    International Nuclear Information System (INIS)

    Franklin, R N

    2003-01-01

    In this review an attempt is made to give a broad coverage of the problem of joining plasma and sheath over a wide range of physical conditions. We go back to the earliest works quoting them, where appropriate, to understand what those who introduced the various terms associated with the structure of the plasma-sheath had in mind. We try to bring out the essence of the insights that have been gained subsequently, by quoting from the literature selectively, indicating how misunderstandings have arisen. In order to make it accessible to the generality of those currently working in low temperature plasmas we have sought to avoid mathematical complexity but retain physical insight, quoting from published work where appropriate. Nevertheless, in clarifying my own ideas I have found it necessary to do additional original work in order to give a consistent picture. In this way I have sought to bring together work in the late 1920s, the 1960s, and now mindful of the commercial importance of plasma processing, work over the past 15 years that adds to the general understanding. (topical review)

  11. Sperm protein 17 is expressed in the sperm fibrous sheath

    Directory of Open Access Journals (Sweden)

    Albani Elena

    2009-07-01

    Full Text Available Abstract Background Sperm protein 17 (Sp17 is a highly conserved mammalian protein characterized in rabbit, mouse, monkey, baboon, macaque, human testis and spermatozoa. mRNA encoding Sp17 has been detected in a range of murine and human somatic tissues. It was also recognized in two myeloma cell lines and in neoplastic cells from patients with multiple myeloma and ovarian carcinoma. These data all indicate that Sp17 is widely distributed in humans, expressed not only in germinal cells and in a variety of somatic tissues, but also in neoplastic cells of unrelated origin. Methods Sp17 expression was analyzed by immunocytochemistry and transmission electron microscopy on spermatozoa. Results Here, we demonstrate the ultrastructural localization of human Sp17 throughout the spermatozoa flagellar fibrous sheath, and its presence in spermatozoa during in vitro states from their ejaculation to the oocyte fertilization. Conclusion These findings suggest a possible role of Sp17 in regulating sperm maturation, capacitation, acrosomal reaction and interactions with the oocyte zona pellucida during the fertilization process. Further, the high degree of sequence conservation throughout its N-terminal half, and the presence of an A-kinase anchoring protein (AKAP-binding motif within this region, suggest that Sp17 might play a regulatory role in a protein kinase A-independent AKAP complex in both germinal and somatic cells.

  12. Birefringence of single and bundled microtubules.

    Science.gov (United States)

    Oldenbourg, R; Salmon, E D; Tran, P T

    1998-01-01

    We have measured the birefringence of microtubules (MTs) and of MT-based macromolecular assemblies in vitro and in living cells by using the new Pol-Scope. A single microtubule in aqueous suspension and imaged with a numerical aperture of 1.4 had a peak retardance of 0.07 nm. The peak retardance of a small bundle increased linearly with the number of MTs in the bundle. Axonemes (prepared from sea urchin sperm) had a peak retardance 20 times higher than that of single MTs, in accordance with the nine doublets and two singlets arrangement of parallel MTs in the axoneme. Measured filament retardance decreased when the filament was defocused or the numerical aperture of the imaging system was decreased. However, the retardance "area," which we defined as the image retardance integrated along a line perpendicular to the filament axis, proved to be independent of focus and of numerical aperture. These results are in good agreement with a theory that we developed for measuring retardances with imaging optics. Our theoretical concept is based on Wiener's theory of mixed dielectrics, which is well established for nonimaging applications. We extend its use to imaging systems by considering the coherence region defined by the optical set-up. Light scattered from within that region interferes coherently in the image point. The presence of a filament in the coherence region leads to a polarization dependent scattering cross section and to a finite retardance measured in the image point. Similar to resolution measurements, the linear dimension of the coherence region for retardance measurements is on the order lambda/(2 NA), where lambda is the wavelength of light and NA is the numerical aperture of the illumination and imaging lenses.

  13. Molecular mechanism of bundle formation by the bacterial actin ParM

    Energy Technology Data Exchange (ETDEWEB)

    Popp, David, E-mail: dpopp@imcb.a-star.edu.sg [ERATO ' Actin Filament Dynamics' Project, Japan Science and Technology Corporation, c/o RIKEN Harima Institute at Spring 8, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, 138673 Singapore (Singapore); Narita, Akihiro [ERATO ' Actin Filament Dynamics' Project, Japan Science and Technology Corporation, c/o RIKEN Harima Institute at Spring 8, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Nagoya University Graduate School of Science, Structural Biology Research Center and Division of Biological Sciences, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan); Iwasa, Mitsusada [ERATO ' Actin Filament Dynamics' Project, Japan Science and Technology Corporation, c/o RIKEN Harima Institute at Spring 8, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Maeda, Yuichiro [ERATO ' Actin Filament Dynamics' Project, Japan Science and Technology Corporation, c/o RIKEN Harima Institute at Spring 8, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Nagoya University Graduate School of Science, Structural Biology Research Center and Division of Biological Sciences, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan); Robinson, Robert C. [Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, 138673 Singapore (Singapore)

    2010-01-22

    The actin homolog ParM plays a microtubule-like role in segregating DNA prior to bacterial cell division. Fluorescence and cryo-electron microscopy have shown that ParM forms filament bundles between separating DNA plasmids in vivo. Given the lack of ParM bundling proteins it remains unknown how ParM bundles form at the molecular level. Here we show using time-lapse TIRF microscopy, under in vitro molecular crowding conditions, that ParM-bundle formation consists of two distinct phases. At the onset of polymerization bundle thickness and shape are determined in the form of nuclei of short helically disordered filaments arranged in a liquid-like lattice. These nuclei then undergo an elongation phase whereby they rapidly increase in length. At steady state, ParM bundles fuse into one single large aggregate. This behavior had been predicted by theory but has not been observed for any other cytomotive biopolymer, including F-actin. We employed electron micrographs of ParM rafts, which are 2-D analogs of 3-D bundles, to identify the main molecular interfilament contacts within these suprastructures. The interface between filaments is similar for both parallel and anti-parallel orientations and the distribution of filament polarity is random within a bundle. We suggest that the interfilament interactions are not due to the interactions of specific residues but rather to long-range, counter ion mediated, electrostatic attractive forces. A randomly oriented bundle ensures that the assembly is rigid and that DNA may be captured with equal efficiency at both ends of the bundle via the ParR binding protein.

  14. Simulation of the influence high-frequency (2 MHz) capacitive gas discharge and magnetic field on the plasma sheath near a surface in hypersonic gas flow

    International Nuclear Information System (INIS)

    Schweigert, I. V.

    2012-01-01

    The plasma sheath near the surface of a hypersonic aircraft formed under associative ionization behind the shock front shields the transmission and reception of radio signals. Using two-dimensional kinetic particle-in-cell simulations, we consider the change in plasma-sheath parameters near a flat surface in a hypersonic flow under the action of electrical and magnetic fields. The combined action of a high-frequency 2-MHz capacitive discharge, a constant voltage, and a magnetic field on the plasma sheath allows the local electron density to be reduced manyfold.

  15. Embedded cladding surface thermocouples on Zircaloy-sheathed heater rods

    International Nuclear Information System (INIS)

    Wilkins, S.C.

    1977-06-01

    Titanium-sheathed Type K thermocouples embedded in the cladding wall of zircaloy-sheathed heater rods are described. These thermocouples constitute part of a program intended to characterize the uncertainty of measurements made by surface-mounted cladding thermocouples on nuclear fuel rods. Fabrication and installation detail, and laboratory testing of sample thermocouple installations are included

  16. Electrospinning jet behaviors under the constraints of a sheath gas

    Directory of Open Access Journals (Sweden)

    Yang Zhao

    2016-11-01

    Full Text Available Increasing the ejection efficiency and uniformity of nanofibers is the key to applications of electrospinning technology. In this work, a novel electrospinning spinneret with a sheath gas passageway is designed. The frictional resistance that stems from the sheath gas provides additional stretching and restriction forces on the jet. The sheath gas also reduces interference and enhances the stability of the charged jet. A bead-on-strain simulation model is built up to determine the constraint effects of the sheath gas. Simulation results show that the sheath gas decreases the motion area and increases the stretching ratio of the liquid jet. The stretching force from the sheath gas decreases the diameter and increases the uniformity of the nanofiber. As the gas pressure increases from 0 kPa to 50 kPa, the critical voltage of the jet ejection decreases from 8.4 kV to 2.5 kV, the diameter of the nanofiber deposition zone decreases from 40 cm to 10 cm, and the diameter of the nanofibers decreases from 557.97 nm to 277.73 nm. The uniformity of nanofibers can be improved significantly using a sheath gas. The sheath gas contributes to the rapid deposition of a uniform nanofibrous membrane and the industrial applications of electrospinning.

  17. Significance of rice sheath photosynthesis: Yield determination by ...

    African Journals Online (AJOL)

    Using high-yielding hybrid rice Liangyopeijiu (LYP9), its male parent 9311 and hybrid rice Shanyou 63 (SY63) as the experimental materials, the photosynthesis of rice sheath was studied by 14C radio-autography. The results showed that rice sheath could trap sunlight and produce photosynthates, and these ...

  18. Anode Sheath Switching in a Carbon Nanotube Arc Plasma

    International Nuclear Information System (INIS)

    Fetterman, Abe; Raitses, Yevgeny; Keidar, Michael

    2008-01-01

    The anode ablation rate is investigated as a function of anode diameter for a carbon nanotube arc plasma. It is found that anomalously high ablation occurs for small anode diameters. This result is explained by the formation of a positive anode sheath. The increased ablation rate due to this positive anode sheath could imply greater production rate for carbon nanotubes.

  19. What is the size of a floating sheath? An answer

    Science.gov (United States)

    Voigt, Farina; Naggary, Schabnam; Brinkmann, Ralf Peter

    2016-09-01

    The formation of a non-neutral boundary sheath in front of material surfaces is universal plasma phenomenon. Despite several decades of research, however, not all related issues are fully clarified. In a recent paper, Chabert pointed out that this lack of clarity applies even to the seemingly innocuous question ``What the size of a floating sheath?'' This contribution attempts to provide an answer that is not arbitrary: The size of a floating sheath is defined as the plate separation of an equivalent parallel plate capacitor. The consequences of the definition are explored with the help of a self-consistent sheath model, and a comparison is made with other sheath size definitions. Deutsche Forschungsgemeinschaft within SFB TR 87.

  20. Effect of collisions on photoelectron sheath in a gas

    Science.gov (United States)

    Sodha, Mahendra Singh; Mishra, S. K.

    2016-02-01

    This paper presents a study of the effect of the collision of electrons with atoms/molecules on the structure of a photoelectron sheath. Considering the half Fermi-Dirac distribution of photo-emitted electrons, an expression for the electron density in the sheath has been derived in terms of the electric potential and the structure of the sheath has been investigated by incorporating Poisson's equation in the analysis. The method of successive approximations has been used to solve Poisson's equation with the solution for the electric potential in the case of vacuum, obtained earlier [Sodha and Mishra, Phys. Plasmas 21, 093704 (2014)], being used as the zeroth order solution for the present analysis. The inclusion of collisions influences the photoelectron sheath structure significantly; a reduction in the sheath width with increasing collisions is obtained.

  1. Photosynthetic and light-enhanced dark fixation of 14CO2 from the ambient atmosphere and 14C-bicarbonate infiltrated through vascular bundles in maize leaves

    International Nuclear Information System (INIS)

    Samejima, Muneaki; Miyachi, Shigetoh

    1978-01-01

    Preillumination of maize leaves in the absence of CO 2 greatly enhanced the capacity for fixing 14 CO 2 into malate and aspartate in the subsequent dark period. The light-enhanced dark fixation of 14 CO 2 lasted for about 1 min. The level of phosphoenolypyruvate in maize leaves in CO 2 -free air did not decrease in the dark subsequent to preillumination. These results indicate that phosphoenolpyruvate carboxylase is activated in light and quickly inactivated in the following darkness. First, labeling method is described, and next, the experiments on the analysis of 14 CO 2 fixation products, the degradation of malate, and the determination of phosphoenolpyruvate in maize leaves are explained. Oxygen-free condition in the atmosphere where the experiments were carried out did not exert any effect on the products by the light-enhanced dark fixation of 14 CO 2 provided from the atmosphere, and the major labeled compounds were malate and aspartate. This indicates that the transfer of carboxyl carbon of C 4 -acids to form 3-phosphoglycerate is light-dependent. When NaH 14 CO 3 solution was vacuum-infiltrated through vascular bundles of maize leaves, the main initial photosynthetic 14 CO 2 -fixation products were phosphate esters. This indicates that by this technique, 14 CO 2 could be directly provided to the bundle sheath cells, and was fixed via the reductive pentose phosphate cycle. While, the main initial 14 CO 2 -fixation products were malate and aspartate even when 14 CO 2 was given through vascular tissues in the dark immediately following preillumination. The possible regulatory mechanisms underlying the above findings are discussed. (Wakatsuki, Y.)

  2. CANFLEX fuel bundle junction pressure drop

    International Nuclear Information System (INIS)

    Chung, H. J.; Chung, C. H.; Jun, J. S.; Hong, S. D.; Chang, S. K.; Kim, B. D.

    1996-11-01

    This report describes the junction pressure drop test results which are to used to determine the alignment angle between bundles to achieve the most probable fuel string pressure drop for randomly aligned bundles for use in the fuel string total pressure drop test. (author). 4 tabs., 17 figs

  3. Anatomic Double-bundle ACL Reconstruction

    NARCIS (Netherlands)

    Schreiber, Verena M.; van Eck, Carola F.; Fu, Freddie H.

    2010-01-01

    Rupture of the anterior cruciate ligament (ACL) is one of the most frequent forms of knee trauma. The traditional surgical treatment for ACL rupture is single-bundle reconstruction. However, during the past few years there has been a shift in interest toward double-bundle reconstruction to closely

  4. CANFLEX fuel bundle strength tests (test report)

    International Nuclear Information System (INIS)

    Chang, Seok Kyu; Chung, C. H.; Kim, B. D.

    1997-08-01

    This document outlines the test results for the strength tests of the CANFLEX fuel bundle. Strength tests are performed to determine and verify the amount of the bundle shape distortion which is against the side-stops when the bundles are refuelling. There are two cases of strength test; one is the double side-stop test which simulates the normal bundle refuelling and the other is the single side-stop test which simulates the abnormal refuelling. the strength test specification requires that the fuel bundle against the side-stop(s) simulators for this test were fabricated and the flow rates were controlled to provide the required conservative hydraulic forces. The test rig conditions of 120 deg C, 11.2 MPa were retained for 15 minutes after the flow rate was controlled during the test in two cases, respectively. The bundle loading angles of number 13- number 15 among the 15 bundles were 67.5 deg CCW and others were loaded randomly. After the tests, the bundle shapes against the side-stops were measured and inspected carefully. The important test procedures and measurements were discussed as follows. (author). 5 refs., 22 tabs., 5 figs

  5. CANFLEX fuel bundle junction pressure drop

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H. J.; Chung, C. H.; Jun, J. S.; Hong, S. D.; Chang, S. K.; Kim, B. D.

    1996-11-01

    This report describes the junction pressure drop test results which are to used to determine the alignment angle between bundles to achieve the most probable fuel string pressure drop for randomly aligned bundles for use in the fuel string total pressure drop test. (author). 4 tabs., 17 figs.

  6. Output commitment through product bundling: experimental evidence

    NARCIS (Netherlands)

    Hinloopen, J.; Mueller, W.; Normann, H.T.

    2011-01-01

    We analyze the impact of product bundling in experimental markets. A firm has monopoly power in one market but faces competition by a second firm in another market. We compare treatments where the monopolist can bundle its two products to treatments where it cannot, and we contrast simultaneous and

  7. Similarities and distinctions of CIR and Sheath

    Science.gov (United States)

    Yermolaev, Yuri; Lodkina, Irina; Nikolaeva, Nadezhda; Yermolaev, Michael

    2016-04-01

    On the basis of OMNI data and our catalog of large scale solar wind (SW) streams during 1976-2000 [Yermolaev et al., 2009] we study the average temporal profiles for two types of compressed regions: CIR (corotating interaction region - compressed region before High Speed Stream (HSS)) and Sheath (compressed region before fast Interplanetary CMEs (ICMEs), including Magnetic Cloud (MC) and Ejecta). As have been shown by Nikolaeva et al, [2015], the efficiency of magnetic storm generation is ~50% higher for Sheath and CIR than for ICME (MC and Ejecta), i.e. reaction magnetosphere depends on type of driver. To take into account the different durations of SW types, we use the double superposed epoch analysis (DSEA) method: rescaling the duration of the interval for all types in such a manner that, respectively, beginning and end for all intervals of selected type coincide [Yermolaev et al., 2010; 2015]. Obtained data allows us to suggest that the formation of all types of compression regions has the same physical mechanism irrespective of piston (HSS or ICME) type and differences are connected with geometry and full jumps of speed in edges of compression regions. If making the natural assumption that the gradient of speed is directed approximately on normal to the piston, CIR has the largest angle between the gradient of speed and the direction of average SW speed, and ICME - the smallest angle. The work was supported by the Russian Foundation for Basic Research, projects 13-02-00158, 16-02-00125 and by Program of Presidium of the Russian Academy of Sciences. References: Nikolaeva, N. S. , Yu. I. Yermolaev, and I. G. Lodkina (2015), Modeling of the Corrected Dst* Index Temporal Profile on the Main Phase of the Magnetic Storms Generated by Different Types of Solar Wind, Cosmic Research, Vol. 53, No. 2, pp. 119-127. Yermolaev, Yu. I., N. S. Nikolaeva, I. G. Lodkina, and M. Yu. Yermolaev (2009), Catalog of Large-Scale Solar Wind Phenomena during 1976-2000, Cosmic Research

  8. Fuel bundle movement due to reverse flow

    Energy Technology Data Exchange (ETDEWEB)

    Wahba, N N; Akalin, O [Ontario Hydro, Toronto, ON (Canada)

    1996-12-31

    When a break occurs in the inlet feeder or inlet header, the rapid depressurization will cause the channel flow to reverse forcing the string of bundles to accelerate and impact with upstream shield plug. A model has been developed to predict the bundle motion due to the channel flow reversal. The model accounts for various forces acting on the bundle. A series of five reverse flow, bundle acceleration experiments have been conducted simulating a break in the inlet feeder of a CANDU fuel channel. The model has been validated against the experiments. The predicted impact velocities are in good agreement with the measured values. It is demonstrated that the model may be successfully used in predicting bundle relocation timing following a large LOCA (loss of coolant). (author). 7 refs., 3 tabs., 11 figs.

  9. Sheath rendezvous method: a novel distal protection technique during endovascular treatment of subclavian artery occlusions.

    Science.gov (United States)

    Haraguchi, Takuya; Urasawa, Kazushi; Nakama, Tatsuya; Nakagawa, Yuya; Tan, Michinao; Koshida, Ryoji; Sato, Katsuhiko

    2016-10-01

    To describe an innovative distal protection technique, "sheath rendezvous method", during endovascular treatment for subclavian arterial occlusions. 4.5F and 6F guiding sheath were inserted from left brachial and common femoral artery, respectively. 0.014″ guidewire retrogradely passed through occlusion and into antegrade sheath to establish a pull-through system. 3.0 mm balloon was used to expand occlusion and anchor to deliver retrograde sheath into antegrade one. Both sheaths locked by balloon dilatation crossed occlusion until antegrade sheath passed over lesion. Balloon expandable stent was delivered within antegrade sheath. Sheath was removed, and stent was implanted. We obtained an excellent outcome without complications.

  10. Chiral equations and fiber bundles

    International Nuclear Information System (INIS)

    Mateos, T.; Becerril, R.

    1992-01-01

    Using the hypothesis g = g (lambda i ), the chiral equations (rhog, z g -1 ), z -bar + (rhog, z -barg -1 ), z = 0 are reduced to a Killing equation of a p-dimensional space V p , being lambda i lambda i (z, z-bar) 'geodesic' parameters of V p . Supposing that g belongs to a Lie group G, one writes the corresponding Lie algebra elements (F) in terms of the Killing vectors of V p and the generators of the subalgebra of F of dimension d = dimension of the Killing space. The elements of the subalgebras belong to equivalence classes which in the respective group form a principal fiber bundle. This is used to integrate the matrix g in terms of the complex variables z and z-bar ( Author)

  11. Characteristics of metal sheathed thermocouples in thermowell

    International Nuclear Information System (INIS)

    Okuda, Takehiro; Nakase, Tsuyoshi; Tanabe, Yutaka; Yamada, Kunitaka; Yoshizaki, Akio; Roko, Kiyokazu

    1987-01-01

    Static and dynamic characteristics of thermowell type thermocouples which are planned to be used for the High-Temperature engineering Test Reactor (HTTR) have been investigated. A mock-up test section was installed in Kawasaki's Helium Test Loop (KH-200). Thermal characteristics tests were carried out under the 600 ∼ 1000 deg C temperature conditions. The test section was equipped with four types sheathed thermocouples; the well type, the non well type, and ones with and without the thermal radiation shielding plate. The measured temperature by the well type thermocouples with the shielding plate was only about 1.3 deg C higher than the one without the shielding plate at gas temperature 990 deg C. The measured time constant of the well type thermocouples was about 7 seconds in the condition of the heat transfer coefficient 1600 Kcal/m 2 h deg C on the well surface, and coincided with the calculated one by ''TRUMP'' code. (author)

  12. Estimation of radiation losses from sheathed thermocouples

    International Nuclear Information System (INIS)

    Roberts, I.L.; Coney, J.E.R.; Gibbs, B.M.

    2011-01-01

    Thermocouples are often used for temperature measurements in heat exchangers. However if the radiation losses from a thermocouple in a high temperature gas flow to colder surroundings are ignored significant errors can occur. Even at moderate temperature differences, these can be significant. Prediction of radiation losses from theory can be problematic, especially in situations where there are large variations in the measured temperatures as the emissivity and radiative heat transfer coefficient of the thermocouple are not constant. The following approach combines experimental results with established empirical relationships to estimate losses due to radiation in an annular heat exchanger at temperatures up to 950 o C. - Highlights: → Sheathed thermocouples are often used to measure temperatures in heat exchangers. → Errors are introduced if radiation losses are ignored. → Radiation losses are environment specific and may be significant. → Experimental and theoretical methods are used to estimate losses. → Hot side maximum temperature 950 o C.

  13. The Sheath-less Planar Langmuir Probe

    Science.gov (United States)

    Cooke, D. L.

    2017-12-01

    The Langmuir probe is one of the oldest plasma diagnostics, provided the plasma density and species temperature from analysis of a current-voltage curve as the voltage is swept over a practically chosen range. The analysis depends on a knowledge or theory of the many factors that influence the current-voltage curve including, probe shape, size, nearby perturbations, and the voltage reference. For applications in Low Earth Orbit, the Planar Langmuir Probe, PLP, is an attractive geometry because the ram ion current is very constant over many Volts of a sweep, allowing the ion density and electron temperature to be determined independently with the same instrument, at different points on the sweep. However, when the physical voltage reference is itself small and electrically floating as with a small spacecraft, the spacecraft and probe system become a double probe where the current collection theory depends on the interaction of the spacecraft with the plasma which is generally not as simple as the probe itself. The Sheath-less PLP, SPLP, interlaces on a single ram facing surface, two variably biased probe elements, broken into many small and intertwined segments on a scale smaller than the plasma Debye length. The SPLP is electrically isolated from the rest of the spacecraft. For relative bias potentials of a few volts, the ion current to all segments of each element will be constant, while the electron currents will vary as a function of the element potential and the electron temperature. Because the segments are small, intertwined, and floating, the assembly will always present the same floating potential to the plasma, with minimal growth as a function of voltage, thus sheath-less and still planar. This concept has been modelled with Nascap, and tested with a physical model inserted into a Low Earth Orbit-like chamber plasma. Results will be presented.

  14. Constructing co-Higgs bundles on CP^2

    OpenAIRE

    Rayan, Steven

    2013-01-01

    On a complex manifold, a co-Higgs bundle is a holomorphic vector bundle with an endomorphism twisted by the tangent bundle. The notion of generalized holomorphic bundle in Hitchin's generalized geometry coincides with that of co-Higgs bundle when the generalized complex manifold is ordinary complex. Schwarzenberger's rank-2 vector bundle on the projective plane, constructed from a line bundle on the double cover CP^1 \\times CP^1 \\to CP^2, is naturally a co-Higgs bundle, with the twisted endom...

  15. Plasma-Sheath Instability in Hall Thrusters Due to Periodic Modulation of the Energy of Secondary Electrons in Cyclotron Motion

    International Nuclear Information System (INIS)

    Sydorenko, D.; Smolyakov, A.; Kaganovich, I.; Raitses, Y.

    2008-01-01

    Particle-in-cell simulation of Hall thruster plasmas reveals a plasma-sheath instability manifesting itself as a rearrangement of the plasma sheath near the thruster channel walls accompanied by a sudden change of many discharge parameters. The instability develops when the sheath current as a function of the sheath voltage is in the negative conductivity regime. The major part of the sheath current is produced by beams of secondary electrons counter-streaming between the walls. The negative conductivity is the result of nonlinear dependence of beam-induced secondary electron emission on the plasma potential. The intensity of such emission is defined by the beam energy. The energy of the beam in crossed axial electric and radial magnetic fields is a quasi-periodical function of the phase of cyclotron rotation, which depends on the radial profile of the potential and the thruster channel width. There is a discrete set of stability intervals determined by the final phase of the cyclotron rotation of secondary electrons. As a result, a small variation of the thruster channel width may result in abrupt changes of plasma parameters if the plasma state jumps from one stability interval to another

  16. Use of guiding sheaths in peroral fluoroscopic gastroduodenal stent placement

    International Nuclear Information System (INIS)

    Bae, Jae-Ik; Shin, Ji Hoon; Song, Ho-Young; Yoon, Chang Jin; Nam, Deok Ho; Choi, Won-Chan; Lim, Jin-Oh

    2005-01-01

    Our purpose was to assess the safety and usefulness of guiding sheaths in peroral fluoroscopic gastroduodenal stent placement. Two types of guiding sheath were made from straight polytetrafluoroethylene tubes. Type A was 80 cm in length, 4 mm in outer diameter and 3 mm in inner diameter. Type B was 70 cm in length, 6 mm in outer diameter and 5 mm in inner diameter. The type A sheath was used in 18 patients in whom a catheter-guide wire combination failed to pass through a stricture. The type B sheath was used in 22 patients in whom a stent delivery system failed to pass through the stricture due to loop formation within the gastric lumen. The overall success rate for guiding a catheter-guide wire through a stricture after using the type A sheath was 89%. The overall success rate for passing a stent delivery system through a stricture after using the type B sheath was 100%. All procedures were tolerated by the patients without any significant complications. The guiding sheaths were safe and useful in peroral fluoroscopic gastroduodenal stent placement. (orig.)

  17. ALINE: A device dedicated to understanding radio-frequency sheaths

    Directory of Open Access Journals (Sweden)

    S. Devaux

    2017-08-01

    Full Text Available In fusion devices, radiofrequency (RF antennas are used for heating the plasma. Those antennas and the plasma interact with each other through the so-called RF sheaths, layers of plasma where the quasi-neutrality breaks down and large electric fields arise. Among the effects of RF sheaths, there is the enhancement of the particles and energy fluxes toward the surface of the antenna, which in turn generate hot spots and release impurities, which are both deleterious for plasma operations. RF sheaths comprehension stumbles on the difficulty to achieve in situ measurements of the sheath properties, as scrape-off layer plasmas are a harsh environment. The very goal of the ALINE device is to tackle this issue and to fulfil the blank between numerical simulations and full-scale experiment by providing measurements within the RF sheaths in a controlled environment. In this paper we report on the latest experimental results from ALINE, in which a cylindrical Langmuir probe mounted on a remotely controlled and programmable arm allows for plasma characterizations in the three dimensions of space around the stainless steel antenna, including the sheath. We present a series of density and potential profiles and three dimension (3D maps in the plasma surrounding a stainless-steel RF antenna as well as in the sheath itself, for unmagnetized and magnetized plasmas.

  18. Farris-Tang retractor in optic nerve sheath decompression surgery.

    Science.gov (United States)

    Spiegel, Jennifer A; Sokol, Jason A; Whittaker, Thomas J; Bernard, Benjamin; Farris, Bradley K

    2016-01-01

    Our purpose is to introduce the use of the Farris-Tang retractor in optic nerve sheath decompression surgery. The procedure of optic nerve sheath fenestration was reviewed at our tertiary care teaching hospital, including the use of the Farris-Tang retractor. Pseudotumor cerebri is a syndrome of increased intracranial pressure without a clear cause. Surgical treatment can be effective in cases in which medical therapy has failed and disc swelling with visual field loss progresses. Optic nerve sheath decompression surgery (ONDS) involves cutting slits or windows in the optic nerve sheath to allow cerebrospinal fluid to escape, reducing the pressure around the optic nerve. We introduce the Farris-Tang retractor, a retractor that allows for excellent visualization of the optic nerve sheath during this surgery, facilitating the fenestration of the sheath and visualization of the subsequent cerebrospinal fluid egress. Utilizing a medial conjunctival approach, the Farris-Tang retractor allows for easy retraction of the medial orbital tissue and reduces the incidence of orbital fat protrusion through Tenon's capsule. The Farris-Tang retractor allows safe, easy, and effective access to the optic nerve with good visualization in optic nerve sheath decompression surgery. This, in turn, allows for greater surgical efficiency and positive patient outcomes.

  19. Evaluation of droplet deposition in rod bundle

    International Nuclear Information System (INIS)

    Ji, W.; Gu, C.Y.; Anglart, H.

    1997-01-01

    Deposition model for droplets in gas droplet two-phase flow in rod bundle is developed in this work using the Lagrangian method. The model is evaluated in a 9-rod bundle geometry. The deposition coefficient in the bundle geometry are compared with that in round tube. The influences of the droplet size and gas mass flow rate on deposition coefficient are investigated. Furthermore, the droplet motion is studied in more detail by dividing the bundle channel into sub-channels. The results show that the overall deposition coefficient in the bundle geometry is close to that in the round tube with the diameter equal to the bundle hydraulic diameter. The calculated deposition coefficient is found to be higher for higher gas mass flux and smaller droplets. The study in the sub-channels show that the ratio between the local deposition coefficient for a sub-channel and the averaged value for the whole bundle is close to a constant value, deviations from the mean value for all the calculated cases being within the range of ±13%. (author)

  20. Preliminary report: NIF laser bundle review

    International Nuclear Information System (INIS)

    Tietbohl, G.L.; Larson, D.W.; Erlandson, A.C.

    1995-01-01

    As requested in the guidance memo 1 , this committe determined whether there are compelling reasons to recommend a change from the NIF CDR baseline laser. The baseline bundle design based on a tradeoff between cost and technical risk, which is replicated four times to create the required 192 beams. The baseline amplifier design uses bottom loading 1x4 slab and flashlamp cassettes for amplifier maintenance and large vacuum enclosures (2.5m high x 7m wide in cross-section for each of the two spatial filters in each of the four bundles. The laser beams are arranged in two laser bays configured in a u-shape around the target area. The entire bundle review effort was performed in a very short time (six weeks) and with limited resources (15 personnel part-time). This should be compared to the effort that produced the CDR design (12 months, 50 to 100 personnel). This committee considered three alternate bundle configurations (2x2, 4x2, and 4x4 bundles), and evaluated each bundle against the baseline design using the seven requested issues in the guidance memo: Cost; schedule; performance risk; maintainability/operability; hardware failure cost exposure; activation; and design flexibility. The issues were reviewed to identify differences between each alternate bundle configuration and the baseline

  1. Reconstruction of the time-averaged sheath potential profile in an argon RF plasma using the ion energy distribution

    International Nuclear Information System (INIS)

    Fivaz, M.; Brunner, S.; Schwarzenbach, W.; Howling, A.A.; Hollenstein, C.

    1994-10-01

    Charge-exchange collisions and radio-frequency excitation combine to give peaks in the ion energy distribution measured at the ground electrode of an argon plasma in a capacitive reactor. These peaks are used as a diagnostic to reconstruct the profile of the time-averaged potential in the sheath. Particle-In-Cell simulations show that the method is accurate. The method is applied to investigate the sheath thickness as a function of excitation frequency at constant plasma power. The time-averaged potential is found to be parabolic in both experimental measurements and numerical simulation. (author) 6 figs., 1 tab., 15 refs

  2. Ultrasonographic findings of pilar sheath acanthoma: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Dong Joo; Lee, Sun Joo; Kim, Seong Jin [Inje University College of Medicine, Busan Paik Hospital, Busan (Korea, Republic of)

    2017-08-15

    Pilar sheath acanthoma is a rare benign follicular hamartoma that presents with a central sinus containing keratinous material and is lined by epithelium. It typically occurs on the face, especially on the upper lip and forehead. In our case, the ultrasound (US) feature of pilar sheath acanthoma revealed a well-defined, oval hypoechoic nodule with hypoechoic capping within the dermis over the medial aspect of the calf. To the best of our knowledge, despite many reports on the clinicopathological aspects of pilar sheath acanthoma, this entity has not been well described in the radiologic literature, and US findings have not been documented.

  3. Experimental test of models of radio-frequency plasma sheaths

    International Nuclear Information System (INIS)

    Sobolewski, M.A.

    1997-01-01

    The ion current and sheath impedance were measured at the radio-frequency-powered electrode of an asymmetric, capacitively coupled plasma reactor, for discharges in argon at 1.33 endash 133 Pa. The measurements were used to test the models of the radio frequency sheath derived by Lieberman [IEEE Trans. Plasma Sci. 17, 338 (1989)] and Godyak and Sternberg [Phys. Rev. A 42, 2299 (1990)], and establish the range of pressure and sheath voltage in which they are valid. copyright 1997 American Institute of Physics

  4. Dynamics of Dust in a Plasma Sheath with Magnetic Field

    International Nuclear Information System (INIS)

    Duan Ping; Liu Jinyuan; Gon Ye; Liu Yue; Wang Xiaogang

    2007-01-01

    Dynamics of dust in a plasma sheath with a magnetic field was investigated using a single particle model. The result shows that the radius, initial position, initial velocity of the dust particles and the magnetic field do effect their movement and equilibrium position in the plasma sheath. Generally, the dust particles with the same size, whatever original velocity and position they have, will locate at the same position in the end under the net actions of electrostatic, gravitational, neutral collisional, and Lorentz forces. But the dust particles will not locate in the plasma sheath if their radius is beyond a certain value

  5. Bundle duct interaction studies for fuel assemblies

    International Nuclear Information System (INIS)

    Hsia, H.T.S.; Kaplan, S.

    1981-06-01

    It is known that the wire-wrapped rods and duct in an LMFBR are undergoing a gradual structural distortion from the initially uniform geometry under the combined effects of thermal expansion and irradiation induced swelling and creep. These deformations have a significant effect on flow characteristics, thus causing changes in thermal behavior such as cladding temperature and temperature distribution within a bundle. The temperature distribution may further enhance or retard irradiation induced deformation of the bundle. This report summarizes the results of the continuing effort in investigating the bundle-duct interaction, focusing on the need for the large development plant

  6. Geometry of Quantum Principal Bundles. Pt. 1

    International Nuclear Information System (INIS)

    Durdevic, M.

    1996-01-01

    A theory of principal bundles possessing quantum structure groups and classical base manifolds is presented. Structural analysis of such quantum principal bundles is performed. A differential calculus is constructed, combining differential forms on the base manifold with an appropriate differential calculus on the structure quantum group. Relations between the calculus on the group and the calculus on the bundle are investigated. A concept of (pseudo)tensoriality is formulated. The formalism of connections is developed. In particular, operators of horizontal projection, covariant derivative and curvature are constructed and analyzed. Generalizations of the first Structure Equation and of the Bianchi identity are found. Illustrative examples are presented. (orig.)

  7. Bundles of C*-categories and duality

    OpenAIRE

    Vasselli, Ezio

    2005-01-01

    We introduce the notions of multiplier C*-category and continuous bundle of C*-categories, as the categorical analogues of the corresponding C*-algebraic notions. Every symmetric tensor C*-category with conjugates is a continuous bundle of C*-categories, with base space the spectrum of the C*-algebra associated with the identity object. We classify tensor C*-categories with fibre the dual of a compact Lie group in terms of suitable principal bundles. This also provides a classification for ce...

  8. Element bow profiles from new and irradiated CANDU fuel bundles

    International Nuclear Information System (INIS)

    Dennier, D.; Manzer, A.M.; Ryz, M.A.

    1996-01-01

    Improved methods of measuring element profiles on new CANDU fuel bundles were developed at the Sheridan Park Engineering Laboratory, and have now been applied in the hot cells at Whiteshell Laboratories. For the first time, the outer element profiles have been compared between new, out-reactor tested, and irradiated fuel elements. The comparison shows that irradiated element deformation is similar to that observed on elements in out-reactor tested bundles. In addition to the restraints applied to the element via appendages, the element profile appears to be strongly influenced by gravity and the end loads applied by local deformation of the endplate. Irradiation creep in the direction of gravity also tends to be a dominant factor. (author)

  9. Evaluation of bundle duct interaction by out of pile compressive test of FBR bundles. FFTF type bundle

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Kosuke; Yamamoto, Yuji; Nagamine, Tsuyoshi; Maeda, Koji [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center

    2000-10-01

    Bundle duct interaction (BDI) caused by expansion of fuel pin bundle becomes one of the main limiting factors for fuel life times. Then, it is important for the design of fast reactor fuel assembly to understand the BDI behavior in detail. In order to understand the BDI behavior, out of pile compressive tests were conducted for FFTF type bundle by use of X-ray CT equipment. In these compressive tests, two type bundles with different accuracy of initial wire position were conducted. The objective of this test is to evaluate the influence of the initial error from standard position of wire at the same axial position. The locations of the pins and the duct flats are analyzed from CT image data. Quantitative evaluation was performed at the CT image data and discussed the bundle deformation status under BDI condition. Following results are obtained. 1) The accuracy of initial wire position is strongly depends on the pin-to-duct contact behavior. In the case of bundle with large error from standard position, pin-to-duct contact is delayed. 2) The BDI mitigation of the bundle with small error from standard wire position is following: The elastic ovality is the dominant deformation in mild BDI condition, then the wire dispersion and pin dispersion are occurred in severe BDI condition. 3) The BDI mitigation of the bundle with large error from standard wire position is following: The elastic ovality and local bowing of pins with large error from standard wire position are occurred in mild BDI condition, then pin dispersion is occurred around pins with large error from standard wire position, finally wire dispersion is occurred in severe BDI condition. 4) The existence of pins with large error from standard wire position is effective to delay the pin-to-duct contact, but the existence of these pins is possible to contact of pin- to- pin. (author)

  10. Plasma sheath physics and dose uniformity in enhanced glow discharge plasma immersion ion implantation and deposition

    International Nuclear Information System (INIS)

    Li Liuhe; Li Jianhui; Kwok, Dixon T. K.; Chu, Paul K.; Wang Zhuo

    2009-01-01

    Based on the multiple-grid particle-in-cell code, an advanced simulation model is established to study the sheath physics and dose uniformity along the sample stage in order to provide the theoretical basis for further improvement of enhanced glow discharge plasma immersion ion implantation and deposition. At t=7.0 μs, the expansion of the sheath in the horizontal direction is hindered by the dielectric cage. The electron focusing effect is demonstrated by this model. Most of the ions at the inside wall of the cage are implanted into the edge of the sample stage and a relatively uniform ion fluence distribution with a large peak is observed at the end. Compared to the results obtained from the previous model, a higher implant fluence and larger area of uniformity are disclosed.

  11. Epithelioid variant of malignant peripheral nerve sheath tumor (malignant schwannoma) of the urinary bladder.

    Science.gov (United States)

    Eltoum, I A; Moore, R J; Cook, W; Crowe, D R; Rodgers, W H; Siegal, G P

    1999-10-01

    Sarcoma represents less than 2% of all neoplasms diagnosed or recognized in effusions. Epithelioid peripheral nerve sheath tumor is a rare tumor that is difficult to differentiate from other epithelioid tumors without the use of ancillary studies. A 39-year-old paraplegic man presented with hematuria and a bladder mass that extended to involve the pelvic peritoneum. Light microscopy using hematoxylin-eosin, Papanicolaou, and immunohistochemical stains as well as transmission electron microscopy showed features of epithelioid malignant peripheral nerve sheath tumor with rhabdoid features and an accompanying eosinophilic infiltrate. Cytologic smears confirmed the similarities between the primary tumor in the bladder and the cells in the pelvic fluid and excluded the possibility of reactive changes related to postsurgical radiation. Ancillary studies were critical in narrowing the differential diagnoses and reaching the final conclusion.

  12. Salvianolic acid B protects the myelin sheath around injured spinal cord axons

    Directory of Open Access Journals (Sweden)

    Zhe Zhu

    2016-01-01

    Full Text Available Salvianolic acid B, an active pharmaceutical compound present in Salvia miltiorrhiza, exerts a neuroprotective effect in animal models of brain and spinal cord injury. Salvianolic acid B can promote recovery of neurological function; however, its protective effect on the myelin sheath after spinal cord injury remains poorly understood. Thus, in this study, in vitro tests showed that salvianolic acid B contributed to oligodendrocyte precursor cell differentiation, and the most effective dose was 20 μg/mL. For in vivo investigation, rats with spinal cord injury were intraperitoneally injected with 20 mg/kg salvianolic acid B for 8 weeks. The amount of myelin sheath and the number of regenerating axons increased, neurological function recovered, and caspase-3 expression was decreased in the spinal cord of salvianolic acid B-treated animals compared with untreated control rats. These results indicate that salvianolic acid B can protect axons and the myelin sheath, and can promote the recovery of neurological function. Its mechanism of action is likely to be associated with inhibiting apoptosis and promoting the differentiation and maturation of oligodendrocyte precursor cells.

  13. Microgravity-Driven Optic Nerve/Sheath Biomechanics Simulations

    Science.gov (United States)

    Ethier, C. R.; Feola, A.; Myers, J. G.; Nelson, E.; Raykin, J.; Samuels, B.

    2016-01-01

    Visual Impairment and Intracranial Pressure (VIIP) syndrome is a concern for long-duration space flight. Current thinking suggests that the ocular changes observed in VIIP syndrome are related to cephalad fluid shifts resulting in altered fluid pressures [1]. In particular, we hypothesize that increased intracranial pressure (ICP) drives connective tissue remodeling of the posterior eye and optic nerve sheath (ONS). We describe here finite element (FE) modeling designed to understand how altered pressures, particularly altered ICP, affect the tissues of the posterior eye and optic nerve sheath (ONS) in VIIP. METHODS: Additional description of the modeling methodology is provided in the companion IWS abstract by Feola et al. In brief, a geometric model of the posterior eye and optic nerve, including the ONS, was created and the effects of fluid pressures on tissue deformations were simulated. We considered three ICP scenarios: an elevated ICP assumed to occur in chronic microgravity, and ICP in the upright and supine positions on earth. Within each scenario we used Latin hypercube sampling (LHS) to consider a range of ICPs, ONH tissue mechanical properties, intraocular pressures (IOPs) and mean arterial pressures (MAPs). The outcome measures were biomechanical strains in the lamina cribrosa, optic nerve and retina; here we focus on peak values of these strains, since elevated strain alters cell phenotype and induce tissue remodeling. In 3D, the strain field can be decomposed into three orthogonal components, denoted as first, second and third principal strains. RESULTS AND CONCLUSIONS: For baseline material properties, increasing ICP from 0 to 20 mmHg significantly changed strains within the posterior eye and ONS (Fig. 1), indicating that elevated ICP affects ocular tissue biomechanics. Notably, strains in the lamina cribrosa and retina became less extreme as ICP increased; however, within the optic nerve, the occurrence of such extreme strains greatly increased as

  14. Association of a new type of gliding, filamentous, purple phototrophic bacterium inside bundles of Microcoleus chthonoplastes in hypersaline cyanobacterial mats

    Science.gov (United States)

    D'Amelio, E. D.; Cohen, Y.; Des Marais, D. J.

    1987-01-01

    An unidentified filamentous purple bacterium, probably belonging to a new genus or even a new family, is found in close association with the filamentous, mat-forming cyanobacterium Microcoleus chthonoplastes in a hypersaline pond at Guerrero Negro, Baja California Sur, Mexico, and in Solar Lake, Sinai, Egypt. This organism is a gliding, segmented trichome, 0.8-0.9 micrometer wide. It contains intracytoplasmic stacked lamellae which are perpendicular and obliquely oriented to the cell wall, similar to those described for the purple sulfur bacteria Ectothiorhodospira. These bacteria are found inside the cyanobacterial bundle, enclosed by the cyanobacterial sheath. Detailed transmission electron microscopical analyses carried out in horizontal sections of the upper 1.5 mm of the cyanobacterial mat show this cyanobacterial-purple bacterial association at depths of 300-1200 micrometers, corresponding to the zone below that of maximal oxygenic photosynthesis. Sharp gradients of oxygen and sulfide are established during the day at this microzone in the two cyanobacterial mats studied. The close association, the distribution pattern of this association and preliminary physiological experiments suggest a co-metabolism of sulfur by the two-membered community. This probable new genus of purple bacteria may also grow photoheterotrophically using organic carbon excreted by the cyanobacterium. Since the chemical gradients in the entire photic zone fluctuate widely in a diurnal cycle, both types of metabolism probably take place. During the morning and afternoon, sulfide migrates up to the photic zone allowing photoautotrophic metabolism with sulfide as the electron donor. During the day the photic zone is highly oxygenated and the purple bacteria may either use oxidized species of sulfur such as elemental sulfur and thiosulfate in the photoautotrophic mode or grow photoheterotrophically using organic carbon excreted by M. chthonoplastes. The new type of filamentous purple sulfur

  15. Nuclear fuel bundle disassembly and assembly tool

    International Nuclear Information System (INIS)

    Yates, J.; Long, J.W.

    1975-01-01

    A nuclear power reactor fuel bundle is described which has a plurality of tubular fuel rods disposed in parallel array between two transverse tie plates. It is secured against disassembly by one or more locking forks which engage slots in tie rods which position the transverse plates. Springs mounted on the fuel and tie rods are compressed when the bundle is assembled thereby maintaining a continual pressure against the locking forks. Force applied in opposition to the springs permits withdrawal of the locking forks so that one tie plate may be removed, giving access to the fuel rods. An assembly and disassembly tool facilitates removal of the locking forks when the bundle is to be disassembled and the placing of the forks during assembly of the bundle. (U.S.)

  16. In-pool damaged fuel bundle recovery

    International Nuclear Information System (INIS)

    Piascik, T.G.; Patenaude, R.S.

    1988-01-01

    While preparing to rerack the Oyster Creek Nuclear Generating Station, GPU Nuclear had need to move a damaged fuel bundle. This bundle had no upper tie plate and could not be moved in the normal manner. GPU Nuclear formed a small, dedicated project team to disassemble, package and move this damaged bundle. The team was composed of key personnel from GPU Nuclear Fuels Projects, OCNGS Operations and Proto-Power / Bisco, a specialty contractor who has fuel bundle reconstitution and rod consolidation experience, remote tooling, underwater video systems and experienced technicians. Proven tooling, clear procedures and a simple approach were important, but the key element was the spirit of teamwork and leadership exhibited by the people involved

  17. In-pool damaged fuel bundle recovery

    International Nuclear Information System (INIS)

    Piascik, T.G.; Patenaude, R.S.

    1988-01-01

    While preparing to rerack the Oyster Creek Nuclear Generating Station, GPU Nuclear had need to move a damaged fuel bundle. This bundle had no upper tie plate and could not be moved in the normal manner. GPU Nuclear formed a small, dedicated project team to disassemble, package, and move this damaged bundle. The team was composed of key personnel from GPU Nuclear Fuels Projects, OCNGS Operations and Proto-Power/Bisco, a specialty contractor who has fuel bundle reconstitution and rod consolidation experience, remote tooling, underwater video systems and experienced technicians. Proven tooling, clear procedures and a simple approach were important, but the key element was the spirit of teamwork and leadership exhibited by the people involved. In spite of several emergent problems which a task of this nature presents, this small, close knit utility/vendor team completed the work on schedule and within the exposure and cost budgets

  18. Cadherin-23 may be dynamic in hair bundles of the model sea anemone Nematostella vectensis.

    Directory of Open Access Journals (Sweden)

    Pei-Ciao Tang

    Full Text Available Cadherin 23 (CDH23, a component of tip links in hair cells of vertebrate animals, is essential to mechanotransduction by hair cells in the inner ear. A homolog of CDH23 occurs in hair bundles of sea anemones. Anemone hair bundles are located on the tentacles where they detect the swimming movements of nearby prey. The anemone CDH23 is predicted to be a large polypeptide featuring a short exoplasmic C-terminal domain that is unique to sea anemones. Experimentally masking this domain with antibodies or mimicking this domain with free peptide rapidly disrupts mechanotransduction and morphology of anemone hair bundles. The loss of normal morphology is accompanied, or followed by a decrease in F-actin in stereocilia of the hair bundles. These effects were observed at very low concentrations of the reagents, 0.1-10 nM, and within minutes of exposure. The results presented herein suggest that: (1 the interaction between CDH23 and molecular partners on stereocilia of hair bundles is dynamic and; (2 the interaction is crucial for normal mechanotransduction and morphology of hair bundles.

  19. Zircaloy sheathed thermocouples for PWR fuel rod temperature measurements

    International Nuclear Information System (INIS)

    Anderson, J.V.; Wesley, R.D.; Wilkins, S.C.

    1979-01-01

    Small diameter zircaloy sheathed thermocouples have been developed by EG and G Idaho, Inc., at the Idaho National Engineering Laboratory. Surface mounted thermocouples were developed to measure the temperature of zircaloy clad fuel rods used in the Thermal Fuels Behavior Program (TFBP), and embedded thermocouples were developed for use by the Loss-of-Fluid Test (LOFT) Program for support tests using zircaloy clad electrically heated nuclear fuel rod simulators. The first objective of this developmental effort was to produce zircaloy sheathed thermocouples to replace titanium sheathed thermocouples and thereby eliminate the long-term corrosion of the titanium-to-zircaloy attachment weld. The second objective was to reduce the sheath diameter to obtain faster thermal response and minimize cladding temperature disturbance due to thermocouple attachment

  20. significance of rice sheath photosynthesis: yield determination by c ...

    African Journals Online (AJOL)

    ACSS

    1State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha 410125, P.R. China. 2School of ... for contribution rates of sheath photosynthesis to economical yield. ..... related processes during ripening in rice plants.

  1. Malignant Peripheral Nerve Sheath Tumour of the Maxilla

    Directory of Open Access Journals (Sweden)

    Puja Sahai

    2014-01-01

    Full Text Available A 38-year-old man was diagnosed with malignant peripheral nerve sheath tumour of the maxilla. He was treated with total maxillectomy. Histopathological examination of the resected specimen revealed a close resection margin. The tumour was of high grade with an MIB-1 labelling index of almost 60%. At six weeks following the surgery, he developed local tumour relapse. The patient succumbed to the disease at five months from the time of diagnosis. The present report underlines the locally aggressive nature of malignant peripheral nerve sheath tumour of the maxilla which necessitates an early therapeutic intervention. A complete resection with clear margins is the most important prognostic factor for malignant peripheral nerve sheath tumour in the head and neck region. Adjuvant radiotherapy may be considered to improve the local control. Future research may demarcate the role of targeted therapy for patients with malignant peripheral nerve sheath tumour.

  2. Measure Guideline: Guidance on Taped Insulating Sheathing Drainage Planes

    Energy Technology Data Exchange (ETDEWEB)

    Grin, A. [Building Science Corporation, Somerville, MA (United States); Lstiburek, J. [Building Science Corporation, Somerville, MA (United States)

    2014-09-01

    The goal of this research is to provide durable and long-term water management solutions using exterior insulating sheathing as part of the water management system. It is possible to tape or seal the joints in insulating sheathing to create a drainage plane and even an air control layer. There exists the material durability component of the tape as well as the system durability component being the taped insulating sheathing as the drainage plane. This measure guideline provides best practice and product recommendations from the interviewed contractors and homebuilders who collectively have a vast amount of experience. Three significant issues were discussed with the group, which are required to make taped insulating sheathing a simple, long-term, and durable drainage plane: horizontal joints should be limited or eliminated wherever possible; where a horizontal joint exists use superior materials; and frequent installation inspection and regular trade training are required to maintain proper installation.

  3. Group Coupons: Interpersonal Bundling on the Internet

    OpenAIRE

    Yongmin Chen; Tianle Zhang

    2012-01-01

    Sellers sometimes offer goods for sale under both a regular price and a discount for group purchase if the consumer group reaches some minimum size. This selling practice, which we term interpersonal bundling, has been popularized on the Internet by companies such as Groupon. We explain why interpersonal bundling is a profitable strategy in the presence of demand uncertainty, and how it may further boost profits by stimulating product information dissemination. Other reasons for its profitabi...

  4. A Brief Survey of Higgs Bundles

    OpenAIRE

    Zúñiga-Rojas, Ronald Alberto

    2018-01-01

    Considering a compact Riemann surface of genus greater than two, a Higgs~bundle is a pair composed of a holomorphic bundle over the Riemann surface, joint with an auxiliar vector field, so-called Higgs field. This theory started around thirty years ago, with Hitchin's work, when he reduced the self-duality equations from dimension four to dimension two, and so, studied those equations over Riemann surfaces. Hitchin baptized those fields as "Higgs fields" beacuse in the context of physics and ...

  5. Frobenius splitting of projective toric bundles

    Indian Academy of Sciences (India)

    He Xin

    2018-03-19

    Mar 19, 2018 ... Firstly it is easy to see that the image of s under the restriction map (2.5) falls in the χ-isotypical component of (Uσ , E), i.e. for all t ∈ T .... σ falls in the χ-isotypical component of (E,Uσ ). D. As mentioned in Remark 2.3, for a vector v .... The determinant of a toric bundle. LetE be a toric bundle on a toric variety X ...

  6. Properties of leaves particleboard for sheathing application

    Science.gov (United States)

    Nuryawan, Arif; Rahmawaty

    2018-03-01

    Manufacturing particleboard (PB) made of leaves was carried out to make non-structural building components, such as insulation, partition, wall, and sheathing. Raw materials used dry leaves originated from plantation (palm oil leaves) and forest plantation (magahony leaves). The adhesive used was interior type thermosetting commercial resins, namely 10% urea-formaldehyde (UF) based on oven dry leaves. Hardener used for UF resin was 1% and 3% ammonium chloride (NH4Cl) 20% (w/w), respectively. Technically, the target density of PB was 0.8 g/cm3 with the dimension’s size of (250 x 250 x 10) mm3. The pressure, temperature, and time of pressing of the hot press were 25 kgf/cm2, 120C, and 10 minutes, respectively. After conditioning for one week, the PB then was evaluated their physical and mechanical properties according to Japanese Industrial Standard (JIS) A 5908 (2003). Results of this work showed: 1) Both types of PB (palm oil and mahagony leaves) were feasible to be produced for non-structural applications; 2) Addition of hardener enhanced the physical and mechanical properties of PB; 3) It was recommended to enhance the performance of the PB by manipulation of the raw materials and the design.

  7. Axial sheath dynamics in a plasma focus

    International Nuclear Information System (INIS)

    Soliman, H.M.; El-Khalafawy, T.A.; Masoud, M.M.

    1990-01-01

    This paper presents the result of investigation with a 10 kJ Mather type plasma focus. It is operated in hydrogen gas at ambient pressure of 0.15--1 torr and charging voltage of 8--11 kV. Radial distribution of the current sheath density with axial distance has been estimated. Plasma rotation in the expansion chamber in the absence of external magnetic field has been detected. A plasma flare from the plasma focus region propagating in the radial direction has been observed. Streak photography shows two plasma streams flowing simultaneously out of the muzzle. The mean energy of the electron beam ejected from the pinch region of the focused plasma, was measured by retarding field analyzer to be 0.32 keV. The electron temperature of the plasma focus at peak compression was determined by measuring the X-ray intensity as a function of absorber thickness at a distance of 62 cm from the focus. The electron temperature has been found to 3 keV

  8. Contrast material filling of the peroneal tendon sheath

    International Nuclear Information System (INIS)

    Zadravecz, Gy.; Grexa, E.

    1981-01-01

    In case of complaints after fracture of the calcaneus the common sheath of the peroneus tendons was filled up with contrast material. The tendon sheath was punctured Oehind the external ankle. The three-directional radiograms clearly showed the dislocation and compression of the tendons, caused by the exostosis of the calcaneus. The concomitant tendovaginitis caused the complaints. This alteration was observed in 11% of all the calcaneus fractures. (L.E.)

  9. Composition of the sheath produced by the green alga Chlorella sorokiniana.

    Science.gov (United States)

    Watanabe, K; Imase, M; Sasaki, K; Ohmura, N; Saiki, H; Tanaka, H

    2006-05-01

    To investigate the chemical characterization of the mucilage sheath produced by Chlorella sorokiniana. Algal mucilage sheath was hydrolysed with NaOH, containing EDTA. The purity of the hydrolysed sheath was determined by an ATP assay. The composition of polysaccharide in the sheath was investigated by high-performance anion-exchange chromatography with pulsed amperometric detection. Sucrose, galacturonic acid, xylitol, inositol, ribose, mannose, arabinose, galactose, rhamnose and fructose were detected in the sheath as sugar components. Magnesium was detected in the sheath as a divalent cation using inductively coupled argon plasma. The sheath matrix also contained protein. It appears that the sheath is composed of sugars and metals. Mucilage sheath contains many kinds of saccharides that are produced as photosynthetic metabolites and divalent cations that are contained in the culture medium. This is the first report on chemical characterization of the sheath matrix produced by C. sorokiniana.

  10. Dynamic behaviour of FBR fuel pin bundles

    International Nuclear Information System (INIS)

    Martin, P.H.; Van Dorsselaere, J.P.; Ravenet, A.

    1990-01-01

    A programme of shock tests on a fast neutron reactor subassembly model (SPX1 geometry) including a complete bundle of fuel pins (dummy elements) is being carried out in the BELIER test facility at Cadarache. The purpose of these tests is: to determine the distribution of dynamic forces applied to the fuel rod clads under the impact conditions encountered in a reactor during a earthquake; to reduce as much as possible the conservatism of the methods presently used for the calculation of those forces. The test programme, now being completed, consists of the following steps: impacts on the mock-up in air with an non-compact bundle (situation of the subassembly at beginning of life (BOL) with clearances within the bundle); impacts under the same conditions but with fluid (water) in the subassembly; impacts on the mock-up in air and with a compacted bundle (simulating the conditions of an end-of-life (EOL) bundle with no clearance within the bundle). The accelerations studied in these tests cover the range encountered in design calculations for the subassembly frequencies in beam mode. (author)

  11. Studies of irradiated zircaloy fuel sheathing using XPS

    International Nuclear Information System (INIS)

    Chan, P.K.; Irving, K.G.; Hocking, W.H.; Duclos, A.M.; Gerwing, A.F.

    1995-01-01

    The preliminary results reported here support the hypothesis that CANLUB graphite coating reduces the rate at which oxygen can react with fuel sheathing. X-ray photoelectron spectroscopic (XPS) characterization of Zircaloy sheathing obtained from extended-burnup Bruce-type elements (BDL-406-XY (555 MW.h/kgU) and BDL-406-AAH (731 MW.h/kgU)) irradiated in NRU indicates that CANLUB may reduce fuel sheath oxidation, and hence that fission-liberated oxygen may remain in the fuel. Chemical shifts in the Zr 3d spectra suggest that a stoichiometric (ZrO 2 ) oxide film was formed only on Zircaloy in direct contact with fuel. Particulate fuel adhering to the sheath was also determined to be systematically more oxidized on surfaces with CANLUB than on those without it. The unique association of tin on sheathing specimens with the non-CANLUB-coated specimens might also suggest that the tin had segregated from the sheathing. It must be emphasized that further experiments are required to better define the effect of CANLUB on fuel oxidation. (author). 14 refs., 1 tab., 3 figs

  12. Plasma Sheath Behavior in a Coaxial Discharge Device

    International Nuclear Information System (INIS)

    EL-Aragi, G.; Soliman, H.M.; Masoud, M.M.

    2001-01-01

    The behavior of the plasma sheath has been studied experimentally and theoretically for 3 kJ coaxial discharge device. The discharge takes place in argon gas with pressure of 0.8 mbar. The experiments are conducted with a 10 kV bank charging voltage, which corresponds to 110 kA peak discharge current with time period of 34 μs. The experimental investigations have been studied using a magnetic probes and a miniature Rogowsky coil. A snowplough model is used to drive an analytical solution of the plasma sheath behavior in axial direction. Measurements of radial distribution of plasma sheath current density J r at the muzzle, show that J r has the following relation, J r is proportional to r -1.1 . From the experimental results and theoretical calculations of axial distribution of azimuthal magnetic field induction and plasma sheath velocity, the inclination angle between the normal of the plasma sheath with the axial distance at any axial position is evaluated and it has approximately a constant value for most axial distances. Also, the axial motion of plasma sheath acceleration is estimated experimentally a max = 0.13 x 10 12 ' cm / s 2 at z = 11 cm and from theoretical calculations a max = 0.15 x 10 12 cm/ s 2 at max z = 1.6 cm. A comparison of the experimental results with the theoretical calculations, under the assumption of the snowplough model are not in agreement. (author)

  13. Studies of irradiated zircaloy fuel sheathing using XPS

    Energy Technology Data Exchange (ETDEWEB)

    Chan, P K; Irving, K G [Atomic Energy of Canada Ltd., Chalk River, ON (Canada); Hocking, W H; Duclos, A M; Gerwing, A F [Atomic Energy of Canada Ltd., Pinawa, MB (Canada). Whiteshell Labs.

    1996-12-31

    The preliminary results reported here support the hypothesis that CANLUB graphite coating reduces the rate at which oxygen can react with fuel sheathing. X-ray photoelectron spectroscopic (XPS) characterization of Zircaloy sheathing obtained from extended-burnup Bruce-type elements (BDL-406-XY (555 MW.h/kgU) and BDL-406-AAH (731 MW.h/kgU)) irradiated in NRU indicates that CANLUB may reduce fuel sheath oxidation, and hence that fission-liberated oxygen may remain in the fuel. Chemical shifts in the Zr 3d spectra suggest that a stoichiometric (ZrO{sub 2}) oxide film was formed only on Zircaloy in direct contact with fuel. Particulate fuel adhering to the sheath was also determined to be systematically more oxidized on surfaces with CANLUB than on those without it. The unique association of tin on sheathing specimens with the non-CANLUB-coated specimens might also suggest that the tin had segregated from the sheathing. It must be emphasized that further experiments are required to better define the effect of CANLUB on fuel oxidation. (author). 14 refs., 1 tab., 3 figs.

  14. Dynamic sheath studies in plasma source ion implantation

    International Nuclear Information System (INIS)

    Schever, J.T.; Shamim, M.; Conrad, J.R.

    1990-01-01

    Plasma Source Ion Implantation (PSII) is a non-line-of-sight method for materials processing in which a target is immersed in a plasma and pulse biased to a high negative voltage (∼ 50 kV). A model of the dynamic sheath which forms under these conditions has been developed and applied to planar, cylindrical and spherical geometries. This model assumes that the transient sheath obeys the Child-Langmuir law for space charge limited emission at each instant during the propagation. Ions uncovered by the propagating sheath edge supply the space charge limited current. This yields an equation relating sheath edge velocity to position, which can be integrated to obtain the sheath edge position as a function of time. The same procedure used in cylindrical and spherical geometry results in a similar equation which must be integrated numerically. Comparison of results of experimental measurements, our model and simulation will be presented for the dynamic sheath edge position and target current waveform. Measurements of implanted dose uniformity of wedge shaped targets are also presented

  15. Multimodal imaging in neurofibromatosis type 1-associated nerve sheath tumors

    International Nuclear Information System (INIS)

    Salamon, J.; Adam, G.; Mautner, V.F.; Derlin, T.

    2015-01-01

    Neurofibromatosis type 1 (NF1) is a neurogenetic disorder. Individuals with NF1 may develop a variety of benign and malignant tumors of which peripheral nerve sheath tumors represent the most frequent entity. Plexiform neurofibromas may demonstrate a locally destructive growth pattern, may cause severe symptoms and may undergo malignant transformation into malignant peripheral nerve sheath tumors (MPNSTs). Whole-body magnetic resonance imaging (MRI) represents the reference standard for detection of soft tissue tumors in NF1. It allows for identification of individuals with plexiform neurofibromas, for assessment of local tumor extent, and for evaluation of whole-body tumor burden on T2-weighted imaging. Multiparametric MRI may provide a comprehensive characterization of different tissue properties of peripheral nerve sheath tumors, and may identify parameters associated with malignant transformation. Due to the absence of any radiation exposure, whole-body MRI may be used for serial follow-up of individuals with plexiform neurofibromas. 18 F-fluorodeoxyglucose positron-emission-tomography (FDG PET/CT) allows a highly sensitive and specific detection of MPNST, and should be used in case of potential malignant transformation of a peripheral nerve sheath tumor. PET/CT provides a sensitive whole-body tumor staging. The use of contrast-enhanced CT for diagnosis of peripheral nerve sheath tumors is limited to special indications. To obtain the most precise readings, optimized examination protocols and dedicated radiologists and nuclear medicine physicians familiar with the complex and variable morphologies of peripheral nerve sheath tumors are required.

  16. Atomic Structure of Type VI Contractile Sheath from Pseudomonas aeruginosa.

    Science.gov (United States)

    Salih, Osman; He, Shaoda; Planamente, Sara; Stach, Lasse; MacDonald, James T; Manoli, Eleni; Scheres, Sjors H W; Filloux, Alain; Freemont, Paul S

    2018-02-06

    Pseudomonas aeruginosa has three type VI secretion systems (T6SSs), H1-, H2-, and H3-T6SS, each belonging to a distinct group. The two T6SS components, TssB/VipA and TssC/VipB, assemble to form tubules that conserve structural/functional homology with tail sheaths of contractile bacteriophages and pyocins. Here, we used cryoelectron microscopy to solve the structure of the H1-T6SS P. aeruginosa TssB1C1 sheath at 3.3 Å resolution. Our structure allowed us to resolve some features of the T6SS sheath that were not resolved in the Vibrio cholerae VipAB and Francisella tularensis IglAB structures. Comparison with sheath structures from other contractile machines, including T4 phage and R-type pyocins, provides a better understanding of how these systems have conserved similar functions/mechanisms despite evolution. We used the P. aeruginosa R2 pyocin as a structural template to build an atomic model of the TssB1C1 sheath in its extended conformation, allowing us to propose a coiled-spring-like mechanism for T6SS sheath contraction. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Analytical expression for sheath edge around corner cathodes

    International Nuclear Information System (INIS)

    Sheridan, T E

    2009-01-01

    A simple analytical expression for the position of the sheath edge around a two-dimensional corner cathode with included angle θ c has been discovered. This expression is valid for weakly collisional sheaths in the Child-Langmuir regime φ c >> kT e /e, where -φ c e is the electron temperature. In polar coordinates (r, θ), the sheath edge is given by (r/s 0 )sin[πθ/(2π - θ c )] = [π/(2π - θ c )] where s 0 is the planar sheath width far from the vertex of the corner. This result is verified by comparison with previous numerical solutions (Watterson P A 1989 J. Phys. D: Appl. Phys. 22 1300) for the knife edge (θ c = 0) and convex square corner (θ c = π/2). The observed agreement suggests that this expression gives the sheath edge for all corner angles, both concave and convex. The utility of this result is demonstrated by computing the full sheath solution for a knife-edge cathode with φ c = 100kT e /e.

  18. Genomic and Expression Profiling of Benign and Malignant Nerve Sheath Profiling of Benign and Malignant Nerve Sheath

    Science.gov (United States)

    2007-05-01

    Benign and Malignant Nerve Sheath Tumors in Neurofibromatosis Patients PRINCIPAL INVESTIGATOR: Matt van de Rijn, M.D., Ph.D. Torsten...Annual 3. DATES COVERED 1 May 2006 –30 Apr 2007 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Genomic and Expression Profiling of Benign and Malignant Nerve...Award Number: DAMD17-03-1-0297 Title: Genomic and Expression Profiling of Benign and Malignant Nerve Sheath Tumors in Neurofibromatosis

  19. Modeling of polarization phenomena due to RF sheaths and electron beams in magnetized plasma

    International Nuclear Information System (INIS)

    Faudot, E.

    2005-01-01

    This work investigates the problematic of hot spots induced by accelerated particle fluxes in tokamaks. It is shown that the polarization due to sheaths in the edge plasma in which an electron beam at a high level of energy is injected, can reach several hundreds volts and thus extend the deposition area. The notion of obstructed sheath is introduced and explains the acceleration of energy deposition by the decreasing of the sheath potential. Then, a 2-dimensional fluid modeling of flux tubes in front of ICRF antennae allows us to calculate the rectified potentials taking into account RF polarization currents transverse to magnetic field lines. The 2-dimensional fluid code designed validates the analytical results which show that the DC rectified potential is 50% greater with polarization currents than without. Finally, the simultaneous application of an electron beam and a RF potential reveals that the potentials due to each phenomenon are additives when RF potential is much greater than beam polarization. The density depletion of polarized flux tubes in 2-dimensional PIC (particles in cells) simulations is characterized but not yet explained. (author)

  20. Emilin3 is required for notochord sheath integrity and interacts with Scube2 to regulate notochord-derived Hedgehog signals.

    Science.gov (United States)

    Corallo, Diana; Schiavinato, Alvise; Trapani, Valeria; Moro, Enrico; Argenton, Francesco; Bonaldo, Paolo

    2013-11-01

    The notochord is a transient and essential structure that provides both mechanical and signaling cues to the developing vertebrate embryo. In teleosts, the notochord is composed of a core of large vacuolated cells and an outer layer of cells that secrete the notochord sheath. In this work, we have identified the extracellular matrix glycoprotein Emilin3 as a novel essential component of the zebrafish notochord sheath. The development of the notochord sheath is impaired in Emilin3 knockdown embryos. The patterning activity of the notochord is also affected by Emilin3, as revealed by the increase of Hedgehog (Hh) signaling in Emilin3-depleted embryos and the decreased Hh signaling in embryos overexpressing Emilin3 in the notochord. In vitro and in vivo experiments indicate that Emilin3 modulates the availability of Hh ligands by interacting with the permissive factor Scube2 in the notochord sheath. Overall, this study reveals a new role for an EMILIN protein and reinforces the concept that structure and function of the notochord are strictly linked.

  1. Elevated temperature triggers human respiratory syncytial virus F protein six-helix bundle formation

    International Nuclear Information System (INIS)

    Yunus, Abdul S.; Jackson, Trent P.; Crisafi, Katherine; Burimski, Irina; Kilgore, Nicole R.; Zoumplis, Dorian; Allaway, Graham P.; Wild, Carl T.; Salzwedel, Karl

    2010-01-01

    Human respiratory syncytial virus (RSV) is a major cause of severe lower respiratory tract infection in infants, immunocompromised patients, and the elderly. The RSV fusion (F) protein mediates fusion of the viral envelope with the target cell membrane during virus entry and is a primary target for antiviral drug and vaccine development. The F protein contains two heptad repeat regions, HR1 and HR2. Peptides corresponding to these regions form a six-helix bundle structure that is thought to play a critical role in membrane fusion. However, characterization of six-helix bundle formation in native RSV F protein has been hindered by the fact that a trigger for F protein conformational change has yet to be identified. Here we demonstrate that RSV F protein on the surface of infected cells undergoes a conformational change following exposure to elevated temperature, resulting in the formation of the six-helix bundle structure. We first generated and characterized six-helix bundle-specific antibodies raised against recombinant peptides modeling the RSV F protein six-helix bundle structure. We then used these antibodies as probes to monitor RSV F protein six-helix bundle formation in response to a diverse array of potential triggers of conformational changes. We found that exposure of 'membrane-anchored' RSV F protein to elevated temperature (45-55 deg. C) was sufficient to trigger six-helix bundle formation. Antibody binding to the six-helix bundle conformation was detected by both flow cytometry and cell-surface immunoprecipitation of the RSV F protein. None of the other treatments, including interaction with a number of potential receptors, resulted in significant binding by six-helix bundle-specific antibodies. We conclude that native, untriggered RSV F protein exists in a metastable state that can be converted in vitro to the more stable, fusogenic six-helix bundle conformation by an increase in thermal energy. These findings help to better define the mechanism of

  2. Can the progressive increase of C4 bundle sheath leakiness at low PFD be explained by incomplete suppression of photorespiration?

    NARCIS (Netherlands)

    Kromdijk, J.; Griffiths, H.; Schepers, H.E.

    2010-01-01

    The ability to concentrate CO2 around Rubisco allows C-4 crops to suppress photorespiration. However, as phosphoenolpyruvate regeneration requires ATP, the energetic efficiency of the C-4 pathway at low photosynthetic flux densities (PFD) becomes a balancing act between primary fixation and

  3. Deformations of the generalised Picard bundle

    International Nuclear Information System (INIS)

    Biswas, I.; Brambila-Paz, L.; Newstead, P.E.

    2004-08-01

    Let X be a nonsingular algebraic curve of genus g ≥ 3, and let Mξ denote the moduli space of stable vector bundles of rank n ≥ 2 and degree d with fixed determinant ξ over X such that n and d are coprime. We assume that if g = 3 then n ≥ 4 and if g = 4 then n ≥ 3, and suppose further that n 0 , d 0 are integers such that n 0 ≥ 1 and nd 0 + n 0 d > nn 0 (2g - 2). Let E be a semistable vector bundle over X of rank n 0 and degree d 0 . The generalised Picard bundle W ξ (E) is by definition the vector bundle over M ξ defined by the direct image p M ξ *(U ξ x p X * E) where U ξ is a universal vector bundle over X x M ξ . We obtain an inversion formula allowing us to recover E from W ξ (E) and show that the space of infinitesimal deformations of W ξ (E) is isomorphic to H 1 (X, End(E)). This construction gives a locally complete family of vector bundles over M ξ parametrised by the moduli space M(n 0 ,d 0 ) of stable bundles of rank n 0 and degree d 0 over X. If (n 0 ,d 0 ) = 1 and W ξ (E) is stable for all E is an element of M(n 0 ,d 0 ), the construction determines an isomorphism from M(n 0 ,d 0 ) to a connected component M 0 of a moduli space of stable sheaves over M ξ . This applies in particular when n 0 = 1, in which case M 0 is isomorphic to the Jacobian J of X as a polarised variety. The paper as a whole is a generalisation of results of Kempf and Mukai on Picard bundles over J, and is also related to a paper of Tyurin on the geometry of moduli of vector bundles. (author)

  4. NIF laser bundle review. Final report

    International Nuclear Information System (INIS)

    Tietbohl, G.L.; Larson, D.W.; Erlandson, A.C.

    1995-01-01

    We performed additional bundle review effort subsequent to the completion of the preliminary report and are revising our original recommendations. We now recommend that the NIF baseline laser bundle size be changed to the 4x2 bundle configuration. There are several 4x2 bundle configurations that could be constructed at a cost similar to that of the baseline 4x12 (from $11M more to about $11M less than the baseline; unescalated, no contingency) and provide significant system improvements. We recommend that the building cost estimates (particularly for the in-line building options) be verified by an architect/engineer (A/E) firm knowledgeable about building design. If our cost estimates of the in-line building are accurate and therefore result in a change from the baseline U-shaped building layout, the acceptability of the in-line configuration must be reviewed from an operations viewpoint. We recommend that installation, operation, and maintenance of all laser components be reviewed to better determine the necessity of aisles, which add to the building cost significantly. The need for beam expansion must also be determined since it affects the type of bundle packing that can be used and increases the minimum laser bay width. The U-turn laser architecture (if proven viable) offers a reduction in building costs since this laser design is shorter than the baseline switched design and requires a shorter laser bay

  5. The Child-Langmuir law and analytical theory of collisionless to collision-dominated sheaths

    International Nuclear Information System (INIS)

    Benilov, M S

    2009-01-01

    This paper is concerned with summarizing simple analytical models of space-charge sheaths and tracing their relation to the Child-Langmuir model of an ion sheath. The topics discussed include the Child-Langmuir law and model of a collisionless ion sheath, the Mott-Gurney law and model of a collision-dominated ion sheath, the Bohm model of a collisionless ion-electron sheath, the Su-Lam-Cohen model of a collision-dominated ion-electron sheath, ion sheaths with arbitrary collisionality, high-accuracy boundary conditions for the Child-Langmuir and Mott-Gurney models of an ion sheath and the mathematical sense of Child-Langmuir type models of an ion sheath from the point of view of modern theoretical physics.

  6. Behavior of collisional sheath in electronegative plasma with q-nonextensive electron distribution

    Science.gov (United States)

    Borgohain, Dima Rani; Saharia, K.

    2018-03-01

    Electronegative plasma sheath is addressed in a collisional unmagnetized plasma consisting of q-nonextensive electrons, Boltzmann distributed negative ions and cold fluid positive ions. Considering the positive ion-neutral collisions and ignoring the effects of ionization and collisions between negative species and positive ions (neutrals), a modified Bohm sheath criterion and hence floating potential are derived by using multifluid model. Using the modified Bohm sheath criterion, the sheath characteristics such as spatial profiles of density, potential and net space charge density have been numerically investigated. It is found that increasing values of q-nonextensivity, electronegativity and collisionality lead to a decrease of the sheath thickness and an increase of the sheath potential and the net space charge density. With increasing values of the electron temperature to negative ion temperature ratio, the sheath thickness increases and the sheath potential as well as the net space charge density in the sheath region decreases.

  7. Coronal mass ejections and their sheath regions in interplanetary space

    Science.gov (United States)

    Kilpua, Emilia; Koskinen, Hannu E. J.; Pulkkinen, Tuija I.

    2017-11-01

    Interplanetary coronal mass ejections (ICMEs) are large-scale heliospheric transients that originate from the Sun. When an ICME is sufficiently faster than the preceding solar wind, a shock wave develops ahead of the ICME. The turbulent region between the shock and the ICME is called the sheath region. ICMEs and their sheaths and shocks are all interesting structures from the fundamental plasma physics viewpoint. They are also key drivers of space weather disturbances in the heliosphere and planetary environments. ICME-driven shock waves can accelerate charged particles to high energies. Sheaths and ICMEs drive practically all intense geospace storms at the Earth, and they can also affect dramatically the planetary radiation environments and atmospheres. This review focuses on the current understanding of observational signatures and properties of ICMEs and the associated sheath regions based on five decades of studies. In addition, we discuss modelling of ICMEs and many fundamental outstanding questions on their origin, evolution and effects, largely due to the limitations of single spacecraft observations of these macro-scale structures. We also present current understanding of space weather consequences of these large-scale solar wind structures, including effects at the other Solar System planets and exoplanets. We specially emphasize the different origin, properties and consequences of the sheaths and ICMEs.

  8. Revisiting the plasma sheath—dust in plasma sheath

    Energy Technology Data Exchange (ETDEWEB)

    Das, G. C. [Mathematical Science Division, IASST, Guwahati 781014 (India); Deka, R.; Bora, M. P., E-mail: mpbora@gauhati.ac.in [Physics Department, Gauhati University, Guwahati 781014 (India)

    2016-04-15

    In this work, we have considered the formation of warm plasma sheath in the vicinity of a wall in a plasma with considerable presence of dust particles. As an example, we have used the parameters relevant in case of plasma sheath formed around surfaces of various solid bodies in space, though the results obtained in this work can be applied to any other physical situation such as laboratory plasma. In the ion-acoustic time scale, we neglect the dust dynamics. The dust particles affect the sheath dynamics by affecting the Poisson equation which determines the plasma potential in the sheath region. It is important to note that our calculations are valid only when the amount of dust particles is not sufficient so as to affect the plasma dynamics in the dust-acoustic time scale, but enough to affect the plasma sheath. We have assumed the current to a dust particle to be balanced throughout the analysis. This makes the grain potential dependent on plasma potential, which is then incorporated into the Poisson equation. The resultant numerical model becomes an initial value problem, which is described by a 1-D integro-differential equation, which is then solved self-consistently by incorporating the change in plasma potential caused by inclusion of the dust potential in the Poisson equation.

  9. Sheath-accumulating Propagation of Interplanetary Coronal Mass Ejection

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Takuya; Shibata, Kazunari, E-mail: takahasi@kusastro.kyoto-u.ac.jp [Kwasan and Hida Observatories, Kyoto University, Yamashina, Kyoto 607–8471 (Japan)

    2017-03-10

    Fast interplanetary coronal mass ejections (ICMEs) are the drivers of strong space weather storms such as solar energetic particle events and geomagnetic storms. The connection between the space-weather-impacting solar wind disturbances associated with fast ICMEs at Earth and the characteristics of causative energetic CMEs observed near the Sun is a key question in the study of space weather storms, as well as in the development of practical space weather prediction. Such shock-driving fast ICMEs usually expand at supersonic speeds during the propagation, resulting in the continuous accumulation of shocked sheath plasma ahead. In this paper, we propose a “sheath-accumulating propagation” (SAP) model that describes the coevolution of the interplanetary sheath and decelerating ICME ejecta by taking into account the process of upstream solar wind plasma accumulation within the sheath region. Based on the SAP model, we discuss (1) ICME deceleration characteristics; (2) the fundamental condition for fast ICMEs at Earth; (3) the thickness of interplanetary sheaths; (4) arrival time prediction; and (5) the super-intense geomagnetic storms associated with huge solar flares. We quantitatively show that not only the speed but also the mass of the CME are crucial for discussing the above five points. The similarities and differences between the SAP model, the drag-based model, and the“snow-plow” model proposed by Tappin are also discussed.

  10. An investigation of tendon sheathing filler migration into concrete

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.

    1998-03-01

    During some of the inspections at nuclear power plants with prestressed concrete containments, it was observed that the containments has experienced leakage of the tendon sheathing filler (i.e., streaks). The objective of this activity was to provide an indication of the extent of tendon sheathing filler leakage into the concrete and its affects on concrete properties. Literature was reviewed and concrete core samples were obtained from the Trojan Nuclear Plant and tested. The literature primarily addressed effects of crude or lubricating oils that are known to cause concrete damage. However, these materials have significantly different characteristics relative to the materials used as tendon sheathing fillers. Examination and testing of the concrete cores indicated that the appearance of tendon sheathing filler on the concrete surface was due to leakage from the conduits and its subsequent migration through cracks that were present. Migration of the tendon sheathing filler was confined to the cracks and there was no perceptible movement into the concrete. Results of compressive strength testing indicated that the concrete quality was consistent in the containment and that the strength had increased over 40% in 25.4 years relative to the average compressive strength at 28-days age

  11. Dust crystal in the electrode sheath of a gaseous discharge

    International Nuclear Information System (INIS)

    Schweigert, I.V.; Schweigert, V.A.

    2002-01-01

    The phenomena observed in strongly coupled dusty plasmas in the electrode sheath of gas discharge clearly indicate that the screened Coulomb potential is not valid for inter-particle interaction. The reason why the conventional model breaks down is clear now. The strong electric field, accelerating ions toward the cathode, leads to an asymmetrical particle shielding and the appearance of an attractive component in the inter-particle force. The sheath plasma with micro-particles is non Hamiltonian system because of input of energy from ion flux from the bulk plasma. The models of interaction potential of microparticles in sheath are proposed. The first is the linear effective positive charge (EPC). On the basis of this model the stability of the dust crystal in the sheath is analyzed both analytically and in MD simulations. The scenario of crystal melting is described. The role of different types of defects in the local heating of the crystal is considered. The next non-linear model of sheath plasma with micro-particles allows to find all parameter of plasma crystal: particle charge, inter-particle distance and study the structural transition. We constructed the analytical expression for inter-particle potential and have found the mechanism acceleration of extra particle beneath the monolayer. Recently new more simple analytical kinetic approach, accounting for ion collisions, have been developed. The structural transition in the dust molecular was obtained in simulation with multipole expansion model interaction potential

  12. Coronal mass ejections and their sheath regions in interplanetary space

    Directory of Open Access Journals (Sweden)

    Emilia Kilpua

    2017-11-01

    Full Text Available Abstract Interplanetary coronal mass ejections (ICMEs are large-scale heliospheric transients that originate from the Sun. When an ICME is sufficiently faster than the preceding solar wind, a shock wave develops ahead of the ICME. The turbulent region between the shock and the ICME is called the sheath region. ICMEs and their sheaths and shocks are all interesting structures from the fundamental plasma physics viewpoint. They are also key drivers of space weather disturbances in the heliosphere and planetary environments. ICME-driven shock waves can accelerate charged particles to high energies. Sheaths and ICMEs drive practically all intense geospace storms at the Earth, and they can also affect dramatically the planetary radiation environments and atmospheres. This review focuses on the current understanding of observational signatures and properties of ICMEs and the associated sheath regions based on five decades of studies. In addition, we discuss modelling of ICMEs and many fundamental outstanding questions on their origin, evolution and effects, largely due to the limitations of single spacecraft observations of these macro-scale structures. We also present current understanding of space weather consequences of these large-scale solar wind structures, including effects at the other Solar System planets and exoplanets. We specially emphasize the different origin, properties and consequences of the sheaths and ICMEs.

  13. Sheath-accumulating Propagation of Interplanetary Coronal Mass Ejection

    International Nuclear Information System (INIS)

    Takahashi, Takuya; Shibata, Kazunari

    2017-01-01

    Fast interplanetary coronal mass ejections (ICMEs) are the drivers of strong space weather storms such as solar energetic particle events and geomagnetic storms. The connection between the space-weather-impacting solar wind disturbances associated with fast ICMEs at Earth and the characteristics of causative energetic CMEs observed near the Sun is a key question in the study of space weather storms, as well as in the development of practical space weather prediction. Such shock-driving fast ICMEs usually expand at supersonic speeds during the propagation, resulting in the continuous accumulation of shocked sheath plasma ahead. In this paper, we propose a “sheath-accumulating propagation” (SAP) model that describes the coevolution of the interplanetary sheath and decelerating ICME ejecta by taking into account the process of upstream solar wind plasma accumulation within the sheath region. Based on the SAP model, we discuss (1) ICME deceleration characteristics; (2) the fundamental condition for fast ICMEs at Earth; (3) the thickness of interplanetary sheaths; (4) arrival time prediction; and (5) the super-intense geomagnetic storms associated with huge solar flares. We quantitatively show that not only the speed but also the mass of the CME are crucial for discussing the above five points. The similarities and differences between the SAP model, the drag-based model, and the“snow-plow” model proposed by Tappin are also discussed.

  14. Structural Conservation of the Myoviridae Phage Tail Sheath Protein Fold

    Energy Technology Data Exchange (ETDEWEB)

    Aksyuk, Anastasia A.; Kurochkina, Lidia P.; Fokine, Andrei; Forouhar, Farhad; Mesyanzhinov, Vadim V.; Tong, Liang; Rossmann, Michael G. (SOIBC); (Purdue); (Columbia)

    2012-02-21

    Bacteriophage phiKZ is a giant phage that infects Pseudomonas aeruginosa, a human pathogen. The phiKZ virion consists of a 1450 {angstrom} diameter icosahedral head and a 2000 {angstrom}-long contractile tail. The structure of the whole virus was previously reported, showing that its tail organization in the extended state is similar to the well-studied Myovirus bacteriophage T4 tail. The crystal structure of a tail sheath protein fragment of phiKZ was determined to 2.4 {angstrom} resolution. Furthermore, crystal structures of two prophage tail sheath proteins were determined to 1.9 and 3.3 {angstrom} resolution. Despite low sequence identity between these proteins, all of these structures have a similar fold. The crystal structure of the phiKZ tail sheath protein has been fitted into cryo-electron-microscopy reconstructions of the extended tail sheath and of a polysheath. The structural rearrangement of the phiKZ tail sheath contraction was found to be similar to that of phage T4.

  15. Catheter Associated Urinary Tract Infection Prevention bundle

    Directory of Open Access Journals (Sweden)

    O. Zarkotou

    2017-01-01

    Full Text Available Catheter-associated urinary tract infections (CAUTI are among the most common healthcare-associated infections, and potentially lead to significant morbidity and mortality. Multifaceted infection control strategies implemented as bundles can prevent nosocomial infections associated with invasive devices such as CAUTIs. The components of the CAUTI bundle proposed herein, include appropriate indications for catheterization and recommendations for the procedures of catheter insertion and catheter maintenance and care. Avoiding unnecessary urinary catheter use is the most effective measure for their prevention. To minimize the risk of CAUTI, urinary catheters should be placed only when a clinical valid indication is documented and they should be removed as soon as possible; alternatives to catheterization should also be considered. Aseptic insertion technique, maintenance of closed drainage system and strict adherence to hand hygiene are essential for preventing CAUTI. The successful implementation of the bundle requires education and training for all healthcare professionals and evaluation of surveillance data.

  16. Development of CANDU advanced fuel bundle

    International Nuclear Information System (INIS)

    Suk, H. C.; Hwang, W.; Rhee, B. W.; Jung, S. H.; Chung, C. H.

    1992-05-01

    This research project is underway in cooperation with AECL to develop the CANDU advanced fuel bundle (so-called, CANFLEX) which can enhance reactor safety and fuel economy in comparison with the current CANDU fuel and which can be used with natural uranium, slightly enriched uranium and other advanced fuel cycle. As the final schedule, the advanced fuel will be verified by carrying out a large scale demonstration of the bundle irradiation in a commercial CANDU reactor for 1996 and 1997, and consequently will be used in the existing and future CANDU reactors in Korea. The research activities during this year include the detail design of CANFLEX fuel with natural enriched uranium (CANFLEX-NU). Based on this design, CANFLEX fuel was mocked up. Out-of-pile hydraulic scoping tests were conducted with the fuel in the CANDU Cold Test Loop to investigate the condition under which maximum pressure drop occurs and the maximum value of the bundle pressure drop. (Author)

  17. Experimental investigation of plasma sheaths in magnetic mirror and cusp configurations

    Science.gov (United States)

    Jiang, Zhengqi; Wei, Zi-an; Ma, J. X.

    2017-11-01

    Sheath structures near a metal plate in a magnetized plasma were experimentally investigated in magnetic mirror and cusp configurations. Plasma parameters and the sheath potential distributions were probed by a planar and an emissive probe, respectively. The measured sheath profiles in the mirror configuration show that the sheath thickness first decreases and then increases when the magnetic strength is raised. A magnetic flux-tube model was used to explain this result. In the cusp configuration, the measured sheath thickness decreases with the increase of the coil current creating the magnetic cusp. However, when normalized by the electron Debye length, the dependence of the sheath thickness on the coil current is reversed.

  18. Polyelectrolyte Bundles: Finite size at thermodynamic equilibrium?

    Science.gov (United States)

    Sayar, Mehmet

    2005-03-01

    Experimental observation of finite size aggregates formed by polyelectrolytes such as DNA and F-actin, as well as synthetic polymers like poly(p-phenylene), has created a lot of attention in recent years. Here, bundle formation in rigid rod-like polyelectrolytes is studied via computer simulations. For the case of hydrophobically modified polyelectrolytes finite size bundles are observed even in the presence of only monovalent counterions. Furthermore, in the absence of a hydrophobic backbone, we have also observed formation of finite size aggregates via multivalent counterion condensation. The size distribution of such aggregates and the stability is analyzed in this study.

  19. Bundled payment and enhanced recovery after surgery.

    Science.gov (United States)

    Huang, Jeffrey

    2015-01-01

    Medicare's fee-for-service (FFS) payment model may contribute to unsustainable spending growth. Payers are turning to alternative payment methods. The leading alternative payment model to the FFS problem is bundled payment. The Centers for Medicare & Medicaid Services (CMS) is taking another step to improve healthcare quality at lower cost. The CMS's Center for Medicare and Medicaid Innovation developed four models of bundled payments and 48 discrete clinical condition episodes. Many surgical care procedures are included in the 48 different clinical condition episodes.

  20. Direct His bundle pacing post AVN ablation.

    Science.gov (United States)

    Lakshmanadoss, Umashankar; Aggarwal, Ashim; Huang, David T; Daubert, James P; Shah, Abrar

    2009-08-01

    Atrioventricular nodal (AVN) ablation with concomitant pacemaker implantation is one of the strategies that reduce symptoms in patients with atrial fibrillation (AF). However, the long-term adverse effects of right ventricular (RV) apical pacing have led to the search for alternating sites of pacing. Biventricular pacing produces a significant improvement in functional capacity over RV pacing in patients undergoing AVN ablation. Another alternative site for pacing is direct His bundle to reduce the adverse outcome of RV pacing. Here, we present a case of direct His bundle pacing using steerable lead delivery system in a patient with symptomatic paroxysmal AF with concurrent AVN ablation.

  1. Malignant transformation in a hybrid schwannoma/perineurioma: Addition to the spectrum of a malignant peripheral nerve sheath tumor

    Directory of Open Access Journals (Sweden)

    Bharat Rekhi

    2011-01-01

    Full Text Available Benign nerve sheath tumors include schwannomas, neurofibromas and perineuriomas. The malignant counterpart of a nerve sheath tumor is designated as a malignant peripheral nerve sheath tumor (MPNST. Lately, benign nerve sheath tumors comprising more than one component have been described, including hybrid schwannomas/perineuriomas. However, malignant transformation in a hybrid schwannoma/perineurioma has not been documented so far. Herein, we present a rare case of a young adult male who presented with a soft tissue mass in his right thigh that was excised elsewhere and submitted to us for histopathological review. One of the tissue sections displayed histopathological features of a hybrid schwannoma/perineurioma, including alternate arrangement of benign schwann and perineurial cells, reinforced with S100-P and epithelial membrane antigen positivity, respectively, along with low MIB1 and negative p53 immunostaining. The other two tissue sections showed a spindly sarcomatous tumor that was immunohistochemically positive for S100-P, CD34, p53 and exhibited high MIB1 (30-40%. Diagnosis of a MPNST arising in a hybrid schwannoma/perineurioma was made. This unusual case forms yet another addition to the spectrum of a MPNST.

  2. Effect of electron emission on an ion sheath structure

    International Nuclear Information System (INIS)

    Mishra, M K; Phukan, A; Chakraborty, M

    2014-01-01

    This article reports on the variations of ion sheath structures due to the emission of both hot and cold electrons in the target plasma region of a double plasma device. The ion sheath is produced in front of a negatively biased plate. The plasma is produced by hot filament discharge in the source region, and no discharge is created in the target region of the device. The plate is placed in the target (diffused plasma) region where cold electron emitting filaments are present. These cold electrons are free from maintenance of discharge, which is sustained in the source region. The hot ionizing electrons are present in the source region. Three important parameters are changed by both hot and cold electrons i.e. plasma density, plasma potential and electron temperature. The decrease in plasma potential and the increase in plasma density lead to the contraction of the sheath. (paper)

  3. Anomalous Capacitive Sheath with Deep Radio Frequency Electric Field Penetration

    International Nuclear Information System (INIS)

    Kaganovich, Igor D.

    2002-01-01

    A novel nonlinear effect of anomalously deep penetration of an external radio-frequency electric field into a plasma is described. A self-consistent kinetic treatment reveals a transition region between the sheath and the plasma. Because of the electron velocity modulation in the sheath, bunches in the energetic electron density are formed in the transition region adjusted to the sheath. The width of the region is of order V(subscript T)/omega, where V(subscript T) is the electron thermal velocity, and w is frequency of the electric field. The presence of the electric field in the transition region results in a cooling of the energetic electrons and an additional heating of the cold electrons in comparison with the case when the transition region is neglected

  4. Plasma sheath axial phase dynamics in coaxial device

    Energy Technology Data Exchange (ETDEWEB)

    Soliman, H.M. (Plasma Physics Dept., NRC, Atomic Energy Authority, Cairo (Egypt)); Masoud, M.M. (Plasma Physics Dept., NRC, Atomic Energy Authority, Cairo (Egypt))

    1994-10-01

    The study of the plasma sheath dynamics in the axial phase has been carried out in a 3 kJ coaxial system of Mather type for two different inner electrode (IE) lengths, 20 cm and 31.5 cm. For both lengths, measurements showed that the plasma sheath is splitted into two layers at the breech, which is referred to as a shock front and its magnetic piston. It has been found that the two layers of the plasma current sheath rotate around the inner electrode. At the muzzle the back layer reverse its rotation direction due to the magnetic field structure of the system. Results showed that the axial velocity of the first layer is greater than the second one all over the axial phase within the range between 1.4 and 1.7. (orig.).

  5. Plasma sheath axial phase dynamics in coaxial device

    International Nuclear Information System (INIS)

    Soliman, H.M.; Masoud, M.M.

    1994-01-01

    The study of the plasma sheath dynamics in the axial phase has been carried out in a 3 kJ coaxial system of Mather type for two different inner electrode (IE) lengths, 20 cm and 31.5 cm. For both lengths, measurements showed that the plasma sheath is splitted into two layers at the breech, which is referred to as a shock front and its magnetic piston. It has been found that the two layers of the plasma current sheath rotate around the inner electrode. At the muzzle the back layer reverse its rotation direction due to the magnetic field structure of the system. Results showed that the axial velocity of the first layer is greater than the second one all over the axial phase within the range between 1.4 and 1.7. (orig.)

  6. Spontaneous rectus sheath hematoma: The utility of CT angiography

    Directory of Open Access Journals (Sweden)

    Antonio Pierro, MD

    2018-04-01

    Full Text Available We described the utility of computed tomography (CT angiography in detection of bleeding vessels for a rapid percutaneous arterial embolization of the spontaneous rectus sheath hematoma. A 70-year-old woman comes to our attention with acute abdominal pain and a low hemoglobin level. An unenhanced CT was performed demonstrating a large rectus sheath hematoma. A conservative management was initially established. Despite this therapy, the abdominal pain increased together with a further decrease of hemoglobin values. A CT angiography was then performed, demonstrating an active bleeding within the hematoma and addressing the patient to a rapid percutaneous arterial embolization. Keywords: Rectus sheath hematoma, Acute abdomen, Arterial embolization, CT angiography, Active bleeding

  7. Characteristics of CANDU fuel bundles that caused pressure tube fretting at the bundle midplane

    Energy Technology Data Exchange (ETDEWEB)

    Dennier, D; Manzer, A M [Atomic Energy of Canada Ltd., Mississauga, ON (Canada); Koehn, E [Ontario Hydro, Toronto, ON (Canada)

    1996-12-31

    Detailed measurements on new bundles, and those that caused fretting during in- and out-reactor tests, have given insight into the factors responsible for fretting at the midplane of the inlet bundle. Bottom fuel elements that were attached near radial endplate spokes and had inboard bearing pads in the rolled joint cavity produced a significant portion of the observed fret marks. These elements are influenced by several driving forces that deflect the centre bearing pads towards the pressure tube surface. The evidence suggests that slight changes in bundle design may be possible to reduce pressure tube fretting. (author). 4 refs., 3 tabs., 8 figs.

  8. Impact of bundle deformation on CHF: ASSERT-PV assessment of extended burnup Bruce B bundle G85159W

    International Nuclear Information System (INIS)

    Rao, Y.F.; Manzer, A.M.

    2005-01-01

    This paper presents a subchannel thermalhydraulic analysis of the effect on critical heat flux (CHF) of bundle deformation such as element bow and diametral creep. The bundle geometry is based on the post-irradiation examination (PIE) data of a single bundle from the Bruce B Nuclear Generating Station, Bruce B bundle G85159W, which was irradiated for more than two years in the core during reactor commissioning. The subchannel code ASSERT-PV IST is used to assess changes in CHF and dryout power due to bundle deformation, compared to the reference, undeformed bundle. (author)

  9. Dengue fever with rectus sheath hematoma: A case report

    Directory of Open Access Journals (Sweden)

    Anurag Sharma

    2014-01-01

    Full Text Available Dengue fever, also known as breakbone fever, is an infectious tropical disease caused by the Dengue virus. It is associated with a number of complications, which are well documented. However, Dengue fever associated with rectus sheath hematoma (RSH is a very rare complication. Only one case report has been published prior supporting the association of Dengue fever with RSH. We report a case of Dengue fever who presented with RSH and was successfully treated conservatively. RSH is also an uncommon cause of acute abdominal pain. It is accumulation of blood in the sheath of the rectus abdominis, secondary to rupture of an epigastric vessel or muscle tear.

  10. Use of a hot sheath Tormac for advance fuels

    International Nuclear Information System (INIS)

    Levine, M.A.

    1977-01-01

    The use of hot electrons in a Tormac sheath is predicted to improve stability and increase ntau by an order of magnitude. An effective ntau for energy containment is derived and system parameters for several advance fuels are shown. In none of the advance fuels cases considered is a reactor with fields greater than 10 Wb or major plasma radius of more than 3 m required for ignition. Minimum systems have power output of under 100 MW thermal. System parameters for a hot sheath Tormac have a wide latitude. Sizes, magnetic fields, operating temperatures can be chosen to optimize engineering and economic considerations

  11. BWR fuel assembly with improved spacer and fuel bundle design for enhanced thermal-hydraulic performance

    International Nuclear Information System (INIS)

    Mildrum, C.M.; Taleyarkhan, R.P.

    1987-01-01

    In a fuel assembly having a bundle of elongated fuel rods disposed in side-by-side relationship so as to form an array of spaced fuel rods, an outer tubular flow channel surrounding the fuel rods so as to direct flow of coolant/moderator fluid along the fuel rods, a hollow water cross extending centrally through and interconnected with the outer flow channel so as to divide the channel into separate compartments and the bundle of fuelrods into a plurality of mini-bundles thereof being disposed in the compartments, and spacers axially displaced along the fuel rods in each of the mini-bundles thereof. Each spacer is composed of inner and outer means which together define spacer cells at corner, side and interior locations of the spacer and have respective protrusions formed thereon which extend into cells so as to maintain the fuel rods received through the spacer cells in laterally spaced relationships. The improvement is described which comprises: (a) a generally uniform poison coating within at least a majority of the fuel rods; (b) a predetermined pattern of fuel enrichment with respect to the fuel rods of each mini-bundle thereof which together with the uniform poison coating within the fuel rods ensures that the packing powers of the fuel rods in the corner and side cells of the spacers are less than the peaking power of a leading one of the fuel rods in the interior cells of the spacers; and (c) each of the fuel rods being received through the cells of each spacer having a diametric size smaller than that of each of the fuel rods received through the side and interior cells of each spacer, the diametric sizes of each of the fuel rods received through the side and interior cells of each spacer being generally equal

  12. Fiber bundle geometry and space-time structure

    International Nuclear Information System (INIS)

    Nascimento, J.C.

    1977-01-01

    Within the framework of the geometric formulation of Gauge theories in fiber bundles, the general relation between the bundle connection (Gauge field) and the geometry of the base space is obtained. A possible Gauge theory for gravitation is presented [pt

  13. Automated negotiation and bundling of information goods

    NARCIS (Netherlands)

    Somefun, D.J.A.; Gerding, E.H.; Bohté, S.M.; Poutré, la J.A.; Faratin, P.; Parkes, D.; Rodriquez-Aguilar, J.

    2004-01-01

    In this paper, we present a novel system for selling bundles of news items. Through the system, customers bargain with the seller over the price and quality of the delivered goods. The advantage of the developed system is that it allows for a high degree of flexibility in the price, quality, and

  14. Jacobi bundles and the BFV-complex

    Czech Academy of Sciences Publication Activity Database

    Le, Hong-Van; Tortorella, A. G.; Vitagliano, L.

    2017-01-01

    Roč. 121, November (2017), s. 347-377 ISSN 0393-0440 Institutional support: RVO:67985840 Keywords : Jacobi manifold * Jacobi bundle * coisotropic submanifolds Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.819, year: 2016 http://www.sciencedirect.com/science/article/pii/S0393044017301948

  15. Optimization of a bundle divertor for FED

    International Nuclear Information System (INIS)

    Hively, L.M.; Rothe, K.E.; Minkoff, M.

    1982-01-01

    Optimal double-T bundle divertor configurations have been obtained for the Fusion Engineering Device (FED). On-axis ripple is minimized, while satisfying a series of engineering constraints. The ensuing non-linear optimization problem is solved via a sequence of quadratic programming subproblems, using the VMCON algorithm. The resulting divertor designs are substantially improved over previous configurations

  16. Large eddy simulation of bundle turbulent flows

    International Nuclear Information System (INIS)

    Hassan, Y.A.; Barsamian, H.R.

    1995-01-01

    Large eddy simulation may be defined as simulation of a turbulent flow in which the large scale motions are explicitly resolved while the small scale motions are modeled. This results into a system of equations that require closure models. The closure models relate the effects of the small scale motions onto the large scale motions. There have been several models developed, the most popular is the Smagorinsky eddy viscosity model. A new model has recently been introduced by Lee that modified the Smagorinsky model. Using both of the above mentioned closure models, two different geometric arrangements were used in the simulation of turbulent cross flow within rigid tube bundles. An inlined array simulations was performed for a deep bundle (10,816 nodes) as well as an inlet/outlet simulation (57,600 nodes). Comparisons were made to available experimental data. Flow visualization enabled the distinction of different characteristics within the flow such as jet switching effects in the wake of the bundle flow for the inlet/outlet simulation case, as well as within tube bundles. The results indicate that the large eddy simulation technique is capable of turbulence prediction and may be used as a viable engineering tool with the careful consideration of the subgrid scale model. (author)

  17. Laughter-induced left bundle branch block.

    Science.gov (United States)

    Chow, Grant V; Desai, Dipan; Spragg, David D; Zakaria, Sammy

    2012-10-01

    We present the case of a patient with ischemic heart disease and intermittent left bundle branch block, reproducibly induced by laughter. Following treatment of ischemia with successful deployment of a drug-eluting stent, no further episodes of inducible LBBB were seen. Transient ischemia, exacerbated by elevated intrathoracic pressure during laughter, may have contributed to onset of this phenomenon. © 2012 Wiley Periodicals, Inc.

  18. LL-37 induces polymerization and bundling of actin and affects actin structure.

    Directory of Open Access Journals (Sweden)

    Asaf Sol

    Full Text Available Actin exists as a monomer (G-actin which can be polymerized to filaments F-actin that under the influence of actin-binding proteins and polycations bundle and contribute to the formation of the cytoskeleton. Bundled actin from lysed cells increases the viscosity of sputum in lungs of cystic fibrosis patients. The human host defense peptide LL-37 was previously shown to induce actin bundling and was thus hypothesized to contribute to the pathogenicity of this disease. In this work, interactions between actin and the cationic LL-37 were studied by optical, proteolytic and surface plasmon resonance methods and compared to those obtained with scrambled LL-37 and with the cationic protein lysozyme. We show that LL-37 binds strongly to CaATP-G-actin while scrambled LL-37 does not. While LL-37, at superstoichiometric LL-37/actin concentrations polymerizes MgATP-G-actin, at lower non-polymerizing concentrations LL-37 inhibits actin polymerization by MgCl(2 or NaCl. LL-37 bundles Mg-F-actin filaments both at low and physiological ionic strength when in equimolar or higher concentrations than those of actin. The LL-37 induced bundles are significantly less sensitive to increase in ionic strength than those induced by scrambled LL-37 and lysozyme. LL-37 in concentrations lower than those needed for actin polymerization or bundling, accelerates cleavage of both monomer and polymer actin by subtilisin. Our results indicate that the LL-37-actin interaction is partially electrostatic and partially hydrophobic and that a specific actin binding sequence in the peptide is responsible for the hydrophobic interaction. LL-37-induced bundles, which may contribute to the accumulation of sputum in cystic fibrosis, are dissociated very efficiently by DNase-1 and also by cofilin.

  19. Fiber bundles in non-relativistic quantum mechanics

    International Nuclear Information System (INIS)

    Moylan, P.

    1979-11-01

    The problem of describing a quantum-mechanical system with symmetry by a fiber bundle is considered. The quantization of a fiber bundle is introduced. Fiber bundles for the Kepler problem and the rotator are constructed. The fiber bundle concept provides a new model for a physical system: it provides a model for an elementary particle with extension having integral values of spin. 5 figures

  20. A suitable boundary condition for bounded plasma simulation without sheath resolution

    International Nuclear Information System (INIS)

    Parker, S.E.; Procassini, R.J.; Birdsall, C.K.; Cohen, B.I.

    1993-01-01

    We have developed a technique that allows for a sheath boundary layer without having to resolve the inherently small space and time scales of the sheath region. We refer to this technique as the logical sheath boundary condition. This boundary condition, when incorporated into a direct-implicit particle code, permits large space- and time-scale simulations of bounded systems, which would otherwise be impractical on current supercomputers. The lack of resolution of the collector sheath potential drop obtained from conventional implicit simulations at moderate values of ω pe Δt and Δz/λ De provides the motivation for the development of the logical sheath boundary condition. The algorithm for use of the logical sheath boundary condition in a particle simulation is presented. Results from simulations which use the logical sheath boundary condition are shown to compare reasonably well with those from an analytic theory and simulations in which the sheath is resolved

  1. Interplanetary Overlay Network Bundle Protocol Implementation

    Science.gov (United States)

    Burleigh, Scott C.

    2011-01-01

    The Interplanetary Overlay Network (ION) system's BP package, an implementation of the Delay-Tolerant Networking (DTN) Bundle Protocol (BP) and supporting services, has been specifically designed to be suitable for use on deep-space robotic vehicles. Although the ION BP implementation is unique in its use of zero-copy objects for high performance, and in its use of resource-sensitive rate control, it is fully interoperable with other implementations of the BP specification (Internet RFC 5050). The ION BP implementation is built using the same software infrastructure that underlies the implementation of the CCSDS (Consultative Committee for Space Data Systems) File Delivery Protocol (CFDP) built into the flight software of Deep Impact. It is designed to minimize resource consumption, while maximizing operational robustness. For example, no dynamic allocation of system memory is required. Like all the other ION packages, ION's BP implementation is designed to port readily between Linux and Solaris (for easy development and for ground system operations) and VxWorks (for flight systems operations). The exact same source code is exercised in both environments. Initially included in the ION BP implementations are the following: libraries of functions used in constructing bundle forwarders and convergence-layer (CL) input and output adapters; a simple prototype bundle forwarder and associated CL adapters designed to run over an IPbased local area network; administrative tools for managing a simple DTN infrastructure built from these components; a background daemon process that silently destroys bundles whose time-to-live intervals have expired; a library of functions exposed to applications, enabling them to issue and receive data encapsulated in DTN bundles; and some simple applications that can be used for system checkout and benchmarking.

  2. Fabrication and use of zircaloy/tantalum-sheathed cladding thermocouples and molybdenum/rhenium-sheathed fuel centerline thermocouples

    International Nuclear Information System (INIS)

    Wilkins, S.C.; Sepold, L.K.

    1985-01-01

    The thermocouples described in this report are zircaloy/tantalum-sheathed and molybdenum/rhenium alloy-sheathed instruments intended for fuel rod cladding and fuel centerline temperature measurements, respectively. Both types incorporate beryllium oxide insulation and tungsten/rhenium alloy thermoelements. These thermocouples, operated at temperatures of 2000 0 C and above, were developed for use in the internationally sponsored Severe Fuel Damage test series in the Power Burst Facility. The fabrication steps for both thermocouple types are described in detail. A laser-welding attachment technique for the cladding-type thermocouple is presented, and experience with alternate materials for cladding and fuel therocouples is discussed

  3. Deformation quantization with separation of variables of an endomorphism bundle

    OpenAIRE

    Karabegov, Alexander

    2013-01-01

    Given a holomorphic Hermitian vector bundle and a star-product with separation of variables on a pseudo-Kaehler manifold, we construct a star product on the sections of the endomorphism bundle of the dual bundle which also has the appropriately generalized property of separation of variables. For this star product we prove a generalization of Gammelgaard's graph-theoretic formula.

  4. Image-Based Edge Bundles : Simplified Visualization of Large Graphs

    NARCIS (Netherlands)

    Telea, A.; Ersoy, O.

    2010-01-01

    We present a new approach aimed at understanding the structure of connections in edge-bundling layouts. We combine the advantages of edge bundles with a bundle-centric simplified visual representation of a graph's structure. For this, we first compute a hierarchical edge clustering of a given graph

  5. Effect of radiofrequency on capacitance of low density plasma sheath

    International Nuclear Information System (INIS)

    Carneiro, L.T.; Cunha Rapozo, C. da

    1988-01-01

    It is shown that the influence of induced radiofrequency potential (V RF ) modifies the Bohm theory on ion saturation current, measured with Langmuir probes. The effect of radiofrequency potential on diode type plasma sheath resonance is also investigated. (M.C.K.)

  6. Malignant peripheral nerve sheath tumor of the oculomotor nerve

    DEFF Research Database (Denmark)

    Kozic, D; Nagulic, M; Ostojic, J

    2006-01-01

    We present the short-term follow-up magnetic resonance (MR) studies and 1H-MR spectroscopy in a child with malignant peripheral nerve sheath tumor of the oculomotor nerve associated with other less aggressive cranial nerve schwannomas. The tumor revealed perineural extension and diffuse nerve...

  7. Double polymer sheathed carbon nanotube supercapacitors show enhanced cycling stability

    Science.gov (United States)

    Zhao, Wenqi; Wang, Shanshan; Wang, Chunhui; Wu, Shiting; Xu, Wenjing; Zou, Mingchu; Ouyang, An; Cao, Anyuan; Li, Yibin

    2015-12-01

    Pseudo-materials are effective in boosting the specific capacitance of supercapacitors, but during service their degradation may also be very strong, causing reduced cycling stability. Here, we show that a carbon nanotube sponge grafted by two conventional pseudo-polymer layers in sequence can serve as a porous supercapacitor electrode with significantly enhanced cycling stability compared with single polymer grafting. Creating conformal polymer coatings on the nanotube surface and the resulting double-sheath configuration are important structural factors leading to the enhanced performance. Combining different polymers as double sheaths as reported here might be a potential route to circumvent the dilemma of pseudo-materials, and to simultaneously improve the capacitance and stability for various energy storage devices.Pseudo-materials are effective in boosting the specific capacitance of supercapacitors, but during service their degradation may also be very strong, causing reduced cycling stability. Here, we show that a carbon nanotube sponge grafted by two conventional pseudo-polymer layers in sequence can serve as a porous supercapacitor electrode with significantly enhanced cycling stability compared with single polymer grafting. Creating conformal polymer coatings on the nanotube surface and the resulting double-sheath configuration are important structural factors leading to the enhanced performance. Combining different polymers as double sheaths as reported here might be a potential route to circumvent the dilemma of pseudo-materials, and to simultaneously improve the capacitance and stability for various energy storage devices. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr05978j

  8. Extraction of antioxidant pigments from dye sorghum leaf sheaths

    NARCIS (Netherlands)

    Kayode, A.P.P.; Bara, C.A.; Dalode-Vieira, G.; Linnemann, A.R.; Nout, M.J.R.

    2012-01-01

    Extraction of antioxidant biocolorant pigments from leaf sheaths of dye sorghum was optimized. Effects of temperature and ethanol concentration of the extraction solvent on the concentrations of the 3-deoxyanthocyanidins, total phenolics and total anthocyanins, and the colour parameters of the

  9. Ion clusters, REB, and current sheath characteristics in focused discharges

    International Nuclear Information System (INIS)

    Bortolotti, A.; Brzosko, J.; DeChiara, P.; Kilic, H.; Mezzetti, F.; Nardi, V.; Powell, C.; Zeng, D.

    1990-01-01

    Small fluctuations in the current sheath characteristics (peak current density, FWHM of leading sheath, control parameters of sheath internal structure) are linked to wide fluctuations of ion and ion cluster emission from the pinch. Magnetic probe data are used for correlating variations of current sheath parameters with particle emission intensity, Z/M composition, particle energy spectrum. The emission of ion and ion clusters at 90 degrees from the axis of a plasma focus discharge is monitored simultaneously with the 0 degrees emission. The particle energy spectrum is analyzed with a Thomson (parabola) spectrometer (time resolution ∼ 1 nanosec). The cross-sectional structure of the REB at 180 degrees along the discharge axis is monitored via the deposition of collective-field accelerated ions on a target in the REB direction. Etched tracks of ion and ion clusters are in all cases recorded on CR-39 plates. Sharp peaks of the D + -ion spectrum at 90 degrees are found for E > 200 keV/unit charge in all focused discharges. These peaks are due to ion crossing of the azimuthal magnetic field of the pinch region, in a predominant ion cluster structure

  10. Electron sheath collapse in an applied-B ion diode

    International Nuclear Information System (INIS)

    Grechikha, A.V.

    1996-01-01

    The effect of the electron sheath collapse in an applied-B ion diode due to the presence of the resistive anode plasma layer was found. This effect is more damaging at higher diode voltages and may be responsible for the parasitic load effect observed in the experiments. (author). 4 figs., 2 refs

  11. Charge of a macroscopic particle in a plasma sheath

    International Nuclear Information System (INIS)

    Samarian, A.A.; Vladimirov, S.V.

    2003-01-01

    Charging of a macroscopic body levitating in a rf plasma sheath is studied experimentally and theoretically. The nonlinear charge vs size dependence is obtained. The observed nonlinearity is explained on the basis of an approach taking into account different plasma conditions for the levitation positions of different particles. The importance of suprathermal electrons' contribution to the charging process is demonstrated

  12. Mineralized fibroma of the tendon sheath presenting as a bursitis

    Energy Technology Data Exchange (ETDEWEB)

    Le Corroller, Thomas; Champsaur, Pierre [Hopital Sainte-Marguerite, Service de Radiologie, Marseille (France); Faculte de Medecine de Marseille, Departement d' Anatomie, Marseille (France); Bouvier-Labit, Corinne [Hopital La Timone, Service d' Anatomopathologie, Marseille (France); Sbihi, Abderrahmane [Clinique Juge, Service de Chirurgie orthopedique, Marseille (France)

    2008-12-15

    We report on the clinical, imaging - including ultrasound, computed tomography, and magnetic resonance imaging - and histological features of a fibroma of the tendon sheath with mineralized chondroid and osseous metaplasia, presenting as a semimembranosus bursitis. The anatomical characteristics of the semimembranosus bursa are demonstrated by dissection in a cadaveric specimen and correlated with the imaging findings in our patient. (orig.)

  13. Mineralized fibroma of the tendon sheath presenting as a bursitis

    International Nuclear Information System (INIS)

    Le Corroller, Thomas; Champsaur, Pierre; Bouvier-Labit, Corinne; Sbihi, Abderrahmane

    2008-01-01

    We report on the clinical, imaging - including ultrasound, computed tomography, and magnetic resonance imaging - and histological features of a fibroma of the tendon sheath with mineralized chondroid and osseous metaplasia, presenting as a semimembranosus bursitis. The anatomical characteristics of the semimembranosus bursa are demonstrated by dissection in a cadaveric specimen and correlated with the imaging findings in our patient. (orig.)

  14. The Bohm criterion for a dusty plasma sheath

    Indian Academy of Sciences (India)

    undergo temperature fluctuations due to collision, the mean square fluctuation in their temperature is much less than the equilibrium temperature. The problem of sheath dynamics with the plasma–wall interactions is of great importance in a number of areas, viz., plasma ion implantation, high-density com- puter chip ...

  15. Malignant Peripheral Nerve Sheath Tumor: MRI and CT Findings

    Directory of Open Access Journals (Sweden)

    K. O. Kragha

    2015-01-01

    important in its diagnosis. A rare case of MPNST that produced urinary retention and bowel incontinence is presented that may aid clinicians in the diagnosis of this rare clinical entity. Motor weakness, central enhancement, and immunohistochemistry may assist in the diagnosis of MPNST and differentiation between benign peripheral nerve sheath tumor (BPNST and MPNST.

  16. On the upper bound in the Bohm sheath criterion

    Energy Technology Data Exchange (ETDEWEB)

    Kotelnikov, I. A., E-mail: I.A.Kotelnikov@inp.nsk.su; Skovorodin, D. I., E-mail: D.I.Skovorodin@inp.nsk.su [Russian Academy of Sciences, Budker Institute of Nuclear Physics, Siberian Branch (Russian Federation)

    2016-02-15

    The question is discussed about the existence of an upper bound in the Bohm sheath criterion, according to which the Debye sheath at the interface between plasma and a negatively charged electrode is stable only if the ion flow velocity in plasma exceeds the ion sound velocity. It is stated that, with an exception of some artificial ionization models, the Bohm sheath criterion is satisfied as an equality at the lower bound and the ion flow velocity is equal to the speed of sound. In the one-dimensional theory, a supersonic flow appears in an unrealistic model of a localized ion source the size of which is less than the Debye length; however, supersonic flows seem to be possible in the two- and three-dimensional cases. In the available numerical codes used to simulate charged particle sources with a plasma emitter, the presence of the upper bound in the Bohm sheath criterion is not supposed; however, the correspondence with experimental data is usually achieved if the ion flow velocity in plasma is close to the ion sound velocity.

  17. Electron sheath collapse in an applied-B ion diode

    Energy Technology Data Exchange (ETDEWEB)

    Grechikha, A V [Forschungszentrum Karlsruhe (Germany). Institut fuer Neutronenphysik und Reaktortechnik

    1997-12-31

    The effect of the electron sheath collapse in an applied-B ion diode due to the presence of the resistive anode plasma layer was found. This effect is more damaging at higher diode voltages and may be responsible for the parasitic load effect observed in the experiments. (author). 4 figs., 2 refs.

  18. Internal pressure effects in the AIRCO-LCT conductor sheath

    International Nuclear Information System (INIS)

    Luton, J.N.; Clinard, J.A.; Lue, J.W.; Gray, W.H.; Summers, L.T.; Kershaw, R.

    1985-01-01

    The large Nb 3 Sn superconducting test coil produced by Westinghouse Electric Corporation for the international Large Coil Task (LCT) utilizes a conductor composed of cabled multifilamentary strands immersed in flowing supercritical helium contained by a square structural sheath made of the high-strength stainless alloy JBX-75. Peak pressures of a few hundred atmospheres are predicted to occur during quench, and measurement of these pressures seems feasible only through penetrations of the sheath wall. Fully processed short lengths of conductor were taken from production ends, fitted with pressure taps and strain gauges, and pressurized with helium gas. Failure, at 1000 atm at liquid nitrogen temperature, was by a catastrophic splitting of the sheath at a corner. Strain measurements and burst pressure agreed with elastic-plastic finite element stress calculations made for the sheath alone. Neither the production seam weld nor the pressure tap penetrations or their fillet welds contributed to the failure, although the finite element calculations show that these areas were also highly stressed, and examination of the failed sample showed that the finite welds were of poor quality. Failure was by tensile overload, with no evidence of fatigue

  19. Calculation Of A Lattice Physics Parameter For SBWR Fuel Bundle Design

    International Nuclear Information System (INIS)

    Sardjono, Y.

    1996-01-01

    The maximum power peaking factor for Nuclear Power Plant SBWR type is 1.5. The precision for that calculation is related with the result of unit cell analysis each rod in the fuel bundles. This analysis consist of lattice eigenvalue, lattice average diffusion cross section as well as relative power peaking factor in the fuel rod for each fuel bundles. The calculation by using TGBLA computer code which is based on the transport and 168 group diffusion theory. From this calculation can be concluded that the maximum relative power peaking factor is 1.304 and lower than design limit

  20. Tau can switch microtubule network organizations: from random networks to dynamic and stable bundles.

    Science.gov (United States)

    Prezel, Elea; Elie, Auréliane; Delaroche, Julie; Stoppin-Mellet, Virginie; Bosc, Christophe; Serre, Laurence; Fourest-Lieuvin, Anne; Andrieux, Annie; Vantard, Marylin; Arnal, Isabelle

    2018-01-15

    In neurons, microtubule networks alternate between single filaments and bundled arrays under the influence of effectors controlling their dynamics and organization. Tau is a microtubule bundler that stabilizes microtubules by stimulating growth and inhibiting shrinkage. The mechanisms by which tau organizes microtubule networks remain poorly understood. Here, we studied the self-organization of microtubules growing in the presence of tau isoforms and mutants. The results show that tau's ability to induce stable microtubule bundles requires two hexapeptides located in its microtubule-binding domain and is modulated by its projection domain. Site-specific pseudophosphorylation of tau promotes distinct microtubule organizations: stable single microtubules, stable bundles, or dynamic bundles. Disease-related tau mutations increase the formation of highly dynamic bundles. Finally, cryo-electron microscopy experiments indicate that tau and its variants similarly change the microtubule lattice structure by increasing both the protofilament number and lattice defects. Overall, our results uncover novel phosphodependent mechanisms governing tau's ability to trigger microtubule organization and reveal that disease-related modifications of tau promote specific microtubule organizations that may have a deleterious impact during neurodegeneration. © 2018 Prezel, Elie, et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  1. Interplay between microtubule bundling and sorting factors ensures acentriolar spindle stability during C. elegans oocyte meiosis.

    Directory of Open Access Journals (Sweden)

    Timothy J Mullen

    2017-09-01

    Full Text Available In many species, oocyte meiosis is carried out in the absence of centrioles. As a result, microtubule organization, spindle assembly, and chromosome segregation proceed by unique mechanisms. Here, we report insights into the principles underlying this specialized form of cell division, through studies of C. elegans KLP-15 and KLP-16, two highly homologous members of the kinesin-14 family of minus-end-directed kinesins. These proteins localize to the acentriolar oocyte spindle and promote microtubule bundling during spindle assembly; following KLP-15/16 depletion, microtubule bundles form but then collapse into a disorganized array. Surprisingly, despite this defect we found that during anaphase, microtubules are able to reorganize into a bundled array that facilitates chromosome segregation. This phenotype therefore enabled us to identify factors promoting microtubule organization during anaphase, whose contributions are normally undetectable in wild-type worms; we found that SPD-1 (PRC1 bundles microtubules and KLP-18 (kinesin-12 likely sorts those bundles into a functional orientation capable of mediating chromosome segregation. Therefore, our studies have revealed an interplay between distinct mechanisms that together promote spindle formation and chromosome segregation in the absence of structural cues such as centrioles.

  2. Thick filament length and isoform composition determine self-organized contractile units in actomyosin bundles.

    Science.gov (United States)

    Thoresen, Todd; Lenz, Martin; Gardel, Margaret L

    2013-02-05

    Diverse myosin II isoforms regulate contractility of actomyosin bundles in disparate physiological processes by variations in both motor mechanochemistry and the extent to which motors are clustered into thick filaments. Although the role of mechanochemistry is well appreciated, the extent to which thick filament length regulates actomyosin contractility is unknown. Here, we study the contractility of minimal actomyosin bundles formed in vitro by mixtures of F-actin and thick filaments of nonmuscle, smooth, and skeletal muscle myosin isoforms with varied length. Diverse myosin II isoforms guide the self-organization of distinct contractile units within in vitro bundles with shortening rates similar to those of in vivo myofibrils and stress fibers. The tendency to form contractile units increases with the thick filament length, resulting in a bundle shortening rate proportional to the length of constituent myosin thick filament. We develop a model that describes our data, providing a framework in which to understand how diverse myosin II isoforms regulate the contractile behaviors of disordered actomyosin bundles found in muscle and nonmuscle cells. These experiments provide insight into physiological processes that use dynamic regulation of thick filament length, such as smooth muscle contraction. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  3. Malignant peripheral nerve sheath tumour of the bladder associated with neurofibromatosis I.

    LENUS (Irish Health Repository)

    O'Brien, Julie

    2008-12-01

    Neurofibromatosis is a hamartomatous disorder of autonomic peripheral nerve sheaths associated with peripheral nerve sheath tumours. Most tumours are neurofibromas; however, the genitourinary system is rarely involved. We present a rare case of a nerve sheath tumour of the bladder in a young patient, which was discovered to be malignant.

  4. 30 CFR 15.32 - Tolerances for weight of explosive, sheath, wrapper, and specific gravity.

    Science.gov (United States)

    2010-07-01

    ..., wrapper, and specific gravity. 15.32 Section 15.32 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... explosive, sheath, wrapper, and specific gravity. (a) The weight of the explosive, the sheath, and the outer.... (c) The specific gravity of the explosive and sheath shall be within ±7.5 percent of that specified...

  5. File list: His.Neu.50.AllAg.Nerve_Sheath_Neoplasms [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Neu.50.AllAg.Nerve_Sheath_Neoplasms mm9 Histone Neural Nerve Sheath Neoplasms h...ttp://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.50.AllAg.Nerve_Sheath_Neoplasms.bed ...

  6. File list: ALL.Neu.50.AllAg.Nerve_Sheath_Neoplasms [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Neu.50.AllAg.Nerve_Sheath_Neoplasms mm9 All antigens Neural Nerve Sheath Neopla...sms SRX337965 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Neu.50.AllAg.Nerve_Sheath_Neoplasms.bed ...

  7. File list: Oth.Neu.05.AllAg.Nerve_Sheath_Neoplasms [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.05.AllAg.Nerve_Sheath_Neoplasms mm9 TFs and others Neural Nerve Sheath Neop...lasms SRX337965 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.05.AllAg.Nerve_Sheath_Neoplasms.bed ...

  8. File list: Pol.Neu.50.AllAg.Nerve_Sheath_Neoplasms [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Neu.50.AllAg.Nerve_Sheath_Neoplasms mm9 RNA polymerase Neural Nerve Sheath Neop...lasms http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Neu.50.AllAg.Nerve_Sheath_Neoplasms.bed ...

  9. File list: Oth.Neu.50.AllAg.Nerve_Sheath_Neoplasms [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.50.AllAg.Nerve_Sheath_Neoplasms mm9 TFs and others Neural Nerve Sheath Neop...lasms SRX337965 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.50.AllAg.Nerve_Sheath_Neoplasms.bed ...

  10. File list: Pol.Neu.20.AllAg.Nerve_Sheath_Neoplasms [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Neu.20.AllAg.Nerve_Sheath_Neoplasms mm9 RNA polymerase Neural Nerve Sheath Neop...lasms http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Neu.20.AllAg.Nerve_Sheath_Neoplasms.bed ...

  11. File list: His.Neu.05.AllAg.Nerve_Sheath_Neoplasms [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Neu.05.AllAg.Nerve_Sheath_Neoplasms mm9 Histone Neural Nerve Sheath Neoplasms h...ttp://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.05.AllAg.Nerve_Sheath_Neoplasms.bed ...

  12. File list: Oth.Neu.20.AllAg.Nerve_Sheath_Neoplasms [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  16. File list: ALL.Neu.20.AllAg.Nerve_Sheath_Neoplasms [Chip-atlas[Archive

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    Lifescience Database Archive (English)

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  20. File list: DNS.Neu.20.AllAg.Nerve_Sheath_Neoplasms [Chip-atlas[Archive

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  1. File list: His.Neu.20.AllAg.Nerve_Sheath_Neoplasms [Chip-atlas[Archive

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  5. File list: His.Neu.10.AllAg.Nerve_Sheath_Neoplasms [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  6. File list: Pol.Neu.05.AllAg.Nerve_Sheath_Neoplasms [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  7. File list: ALL.Neu.05.AllAg.Nerve_Sheath_Neoplasms [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  8. Bundling of harvesting residues and whole-trees and the treatment of bundles; Hakkuutaehteiden ja kokopuiden niputus ja nippujen kaesittely

    Energy Technology Data Exchange (ETDEWEB)

    Kaipainen, H; Seppaenen, V; Rinne, S

    1997-12-31

    The conditions on which the bundling of the harvesting residues from spruce regeneration fellings would become profitable were studied. The calculations showed that one of the most important features was sufficient compaction of the bundle, so that the portion of the wood in the unit volume of the bundle has to be more than 40 %. The tests showed that the timber grab loader of farm tractor was insufficient for production of dense bundles. The feeding and compression device of the prototype bundler was constructed in the research and with this device the required density was obtained.The rate of compaction of the dry spruce felling residues was about 40 % and that of the fresh residues was more than 50 %. The comparison between the bundles showed that the calorific value of the fresh bundle per unit volume was nearly 30 % higher than that of the dry bundle. This means that the treatment of the bundles should be done of fresh felling residues. Drying of the bundles succeeded well, and the crushing and chipping tests showed that the processing of the bundles at the plant is possible. The treatability of the bundles was also excellent. By using the prototype, developed in the research, it was possible to produce a bundle of the fresh spruce harvesting residues, the diameter of which was about 50 cm and the length about 3 m, and the rate of compaction over 50 %. By these values the reduction target of the costs is obtainable

  9. Bundling of harvesting residues and whole-trees and the treatment of bundles; Hakkuutaehteiden ja kokopuiden niputus ja nippujen kaesittely

    Energy Technology Data Exchange (ETDEWEB)

    Kaipainen, H.; Seppaenen, V.; Rinne, S.

    1996-12-31

    The conditions on which the bundling of the harvesting residues from spruce regeneration fellings would become profitable were studied. The calculations showed that one of the most important features was sufficient compaction of the bundle, so that the portion of the wood in the unit volume of the bundle has to be more than 40 %. The tests showed that the timber grab loader of farm tractor was insufficient for production of dense bundles. The feeding and compression device of the prototype bundler was constructed in the research and with this device the required density was obtained.The rate of compaction of the dry spruce felling residues was about 40 % and that of the fresh residues was more than 50 %. The comparison between the bundles showed that the calorific value of the fresh bundle per unit volume was nearly 30 % higher than that of the dry bundle. This means that the treatment of the bundles should be done of fresh felling residues. Drying of the bundles succeeded well, and the crushing and chipping tests showed that the processing of the bundles at the plant is possible. The treatability of the bundles was also excellent. By using the prototype, developed in the research, it was possible to produce a bundle of the fresh spruce harvesting residues, the diameter of which was about 50 cm and the length about 3 m, and the rate of compaction over 50 %. By these values the reduction target of the costs is obtainable

  10. Equipment for detach the fuel elements of the irradiated candu fuel bundle

    International Nuclear Information System (INIS)

    Cojocaru, V.; Dinuta, G.

    2013-01-01

    Monitoring the behaviour of the fuel bundles during their combustion provides useful information for the operation of the nuclear power plant as well as for the fuel manufacturer. Before placing it inside the reactor, the fuel bundle is inspected visually, dimensionally and, during combustion in the reactor, its radioactive behaviour is monitored. The purpose of the presented equipment is to allow the visual external inspection of the damaged fuel bundle in order to identify visible defects and to detach the fuel element by breaking the welded connection between the cap and grid. These devices are operated using the handler devices already existing in the hot cells Post-Irradiation Examination Laboratory (LEPI). This equipment has been used successfully in the LEPI laboratory at SCN Pitesti to inspect the damaged fuel from Cernavoda NPP, in March 2013. (authors)

  11. Comparison of ASSERT subchannel code with Marviken bundle data

    International Nuclear Information System (INIS)

    Tahir, A.; Carver, M.B.

    1984-04-01

    In this paper ASSERT predictions are compared with the Marviken 6-rod bundle and 36+1 rod bundle. The predictions are presented for two experiments in the 6-rod bundle and four experiments in the 36+1 rod bundle. For low inlet subcooling, the void predictions are in good agreement with the experimental data. For high inlet subcooling, however, the agreement is not as good. This is attributed to the fact that in the high inlet subcooling experiments, single phase turbulent mixing plays a more important role in determining flow conditions in the bundle

  12. Triviality and Split of Vector Bundles on Rationally Connected Varieties

    OpenAIRE

    Pan, Xuanyu

    2013-01-01

    In this paper, we give a simple proof of a triviality criterion due to I.Biswas and J.Pedro and P.Dos Santos. We also prove a vector bundle on a homogenous space is trivial if and only if the restrictions of the vector bundle to Schubert lines are trivial. Using this result and Chern classes of vector bundles, we give a general criterion of a uniform vector bundle on a homogenous space to be splitting. As an application, we prove a uniform vector bundle on classical Grassmannians and quadrics...

  13. DP-THOT - a calculational tool for bundle-specific decay power based on actual irradiation history

    International Nuclear Information System (INIS)

    Johnston, S.; Morrison, C.A.; Albasha, H.; Arguner, D.

    2005-01-01

    A tool has been created for calculating the decay power of an individual fuel bundle to take account of its actual irradiation history, as tracked by the fuel management code SORO. The DP-THOT tool was developed in two phases: first as a standalone executable code for decay power calculation, which could accept as input an entirely arbitrary irradiation history; then as a module integrated with SORO auxiliary codes, which directly accesses SORO history files to retrieve the operating power history of the bundle since it first entered the core. The methodology implemented in the standalone code is based on the ANSI/ANS-5.1-1994 formulation, which has been specifically adapted for calculating decay power in irradiated CANDU reactor fuel, by making use of fuel type specific parameters derived from WIMS lattice cell simulations for both 37 element and 28 element CANDU fuel bundle types. The approach also yields estimates of uncertainty in the calculated decay power quantities, based on the evaluated error in the decay heat correlations built-in for each fissile isotope, in combination with the estimated uncertainty in user-supplied inputs. The method was first implemented in the form of a spreadsheet, and following successful testing against decay powers estimated using the code ORIGEN-S, the algorithm was coded in FORTRAN to create an executable program. The resulting standalone code, DP-THOT, accepts an arbitrary irradiation history and provides the calculated decay power and estimated uncertainty over any user-specified range of cooling times, for either 37 element or 28 element fuel bundles. The overall objective was to produce an integrated tool which could be used to find the decay power associated with any identified fuel bundle or channel in the core, taking into account the actual operating history of the bundles involved. The benefit is that the tool would allow a more realistic calculation of bundle and channel decay powers for outage heat sink planning

  14. Rod bundle burnout data and correlation comparisons

    International Nuclear Information System (INIS)

    Yoder, G.L.; Morris, D.G.; Mullins, C.B.

    1985-01-01

    Rod bundle burnout data from 30 steady-state and 3 transient tests were obtained from experiments performed in the Thermal Hydraulic Test Facility at the Oak Ridge National Laboratory. The tests covered a parameter range relevant to intact core reactor accidents ranging from large break to small break loss-ofcoolant conditions. Instrumentation within the 64-rod test section indicated that burnout occurred over an axial range within the bundle. The distance from the point where the first dry rod was detected to the point where all rods were dry was up to 60 cm in some of the tests. The burnout data should prove useful in developing new correlations for use in reactor thermalhydraulic codes. Evaluation of several existing critical heat flux correlations using the data show that three correlations, the Barnett, Bowring, and Katto correlations, perform similarly and correlate the data better than the Biasi correlation

  15. The turbulent flow in rod bundles

    International Nuclear Information System (INIS)

    Moeller, S.V.

    1989-01-01

    Experimental studies have shown that the axial and azimuthal turbulence intensities in the gap regions of rod bundles increase strongly with decreasing rod spacing; the fluctuating velocities in the axial and azimuthal directions have a quasi-periodic behaviour. To determine the origin of this phenomenon, an its characteristics as a function of the geometry and the Reynolds number, an experimental investigation was performed on the turbulent in several rod bundles with different aspect ratios (P/D, W/D). Hot-wires and microsphones were used for the measurements of velocity and wall pressure fluctuations. The data were evaluated to obtain spectra as well as auto and cross correlations. Based on the results, a phenomenological model is presented to explain this phenomenon. By means of the model, the mass exchange between neighbouring subchannels is explained [pt

  16. Reactor application of an improved bundle divertor

    International Nuclear Information System (INIS)

    Yang, T.F.; Ruck, G.W.; Lee, A.Y.; Smeltzer, G.; Prevenslik, T.

    1978-11-01

    A Bundle Divertor was chosen as the impurity control and plasma exhaust system for the beam driven Demonstration Tokamak Hybrid Reactor - DTHR. In the context of a preconceptual design study of the reactor and associated facility a bundle divertor concept was developed and integrated into the reactor system. The overall system was found feasible and scalable for reactors with intermediate torodial field strengths on axis. The important design characteristics are: the overall average current density of the divertor coils is 0.73 kA for each tesla of toroidal field on axis; the divertor windings are made from super-conducting cables supported by steel structures and are designed to be maintainable; the particle collection assembly and auxiliary cryosorption vacuum pump are dual systems designed such that they can be reactivated alterntively to allow for continuous reactor operation; and the power requirement for energizing and operating the divertor is about 5 MW

  17. On stability of Kummer surfaces' tangent bundle

    International Nuclear Information System (INIS)

    Bozhkov, Y.D.

    1988-10-01

    In this paper we propose an explicit approximation of the Kaehler-Einstein-Calabi-Yau metric on the Kummer surfaces, which are manifolds of type K3. It is constructed by gluing 16 pieces of the Eguchi-Hanson metric and 16 pieces of the Euclidean metric. Two estimates on its curvature are proved. Then we prove an estimate on the first eigenvalue of a covariant differential operator of second order. This enables us to apply Taubes' iteration procedure to obtain that there exists an anti-self-dual connection on the considered Kummer surface. In fact, it is a Hermitian-Einstein connection from which we conclude that Kummer surfaces' co-tangent bundle is stable and therefore their tangent bundle is stable too. (author). 40 refs

  18. SIKAP KONSUMEN TERHADAP PRODUK BUNDLING AGRIBISNIS

    Directory of Open Access Journals (Sweden)

    Didi Junaedi

    2017-04-01

    implementation to Dekalb brand hybrid corn and Round-up brand herbicide. By analyzes how consumer attitudes toward buying intention in this regard farmers as buyer and retailers as products services. The data used is primary data. Primary data is obtained using 2 kind of respondents are retailers and farmers. The data obtained by distributed 30 questionnaires for retailers and 110 farmers in Grobogan. The descriptive statistic employed to analyzed data by using multiple linear regressions with t test, F test and coefficient of determination. The result showed that on retailers respondents attribute the product bundling has no significant influence to consumer buying intention but consumer attitudes significantly influence the buying intention. On the farmers respondents showed that attributes of the product bundling and consumer attitudes positive and significant influence to buying intention.

  19. Tube bundle vibrations in transversal flow

    International Nuclear Information System (INIS)

    Gibert, R.J.; Sagner, M.

    1978-01-01

    This study gives important information concerning characteristic parameters about lock-in and whirling instability phenomena, in the case of tube arrays. The work is mainly an experimental one though models are also developed: 1) an equilateral pitch bundle (p=1,5 D with D=tube diameter) is tested. Tube damping (epsilon) and first eigenfrequency (f), flow velocity are explored in a large domain. Vibratory level of the tubes are measured and critical points are ploted on the fluidelastic parameters diagram. Several bundles with various usual pitches and arrangements (in line or staggered) are tested. Critical velocities are measured and the whirling instability characteristic coefficient is tabulated. A complementary experiment is made on tube rows with various pitches. This gives valuable informations concerning the look-in domain in VR and A'R diagram. Furthermore this puts in evidence the important effect of a frequency difference between two adjacent tubes on the whirling critical velocity

  20. Constrained ripple optimization of Tokamak bundle divertors

    International Nuclear Information System (INIS)

    Hively, L.M.; Rome, J.A.; Lynch, V.E.; Lyon, J.F.; Fowler, R.H.; Peng, Y-K.M.; Dory, R.A.

    1983-02-01

    Magnetic field ripple from a tokamak bundle divertor is localized to a small toroidal sector and must be treated differently from the usual (distributed) toroidal field (TF) coil ripple. Generally, in a tokamak with an unoptimized divertor design, all of the banana-trapped fast ions are quickly lost due to banana drift diffusion or to trapping between the 1/R variation in absolute value vector B ω B and local field maxima due to the divertor. A computer code has been written to optimize automatically on-axis ripple subject to these constraints, while varying up to nine design parameters. Optimum configurations have low on-axis ripple ( 0 ) are lost. However, because finite-sized TF coils have not been used in this study, the flux bundle is not expanded

  1. Fiber Bundle Model Under Heterogeneous Loading

    Science.gov (United States)

    Roy, Subhadeep; Goswami, Sanchari

    2018-03-01

    The present work deals with the behavior of fiber bundle model under heterogeneous loading condition. The model is explored both in the mean-field limit as well as with local stress concentration. In the mean field limit, the failure abruptness decreases with increasing order k of heterogeneous loading. In this limit, a brittle to quasi-brittle transition is observed at a particular strength of disorder which changes with k. On the other hand, the model is hardly affected by such heterogeneity in the limit where local stress concentration plays a crucial role. The continuous limit of the heterogeneous loading is also studied and discussed in this paper. Some of the important results related to fiber bundle model are reviewed and their responses to our new scheme of heterogeneous loading are studied in details. Our findings are universal with respect to the nature of the threshold distribution adopted to assign strength to an individual fiber.

  2. Uncovering ecosystem service bundles through social preferences.

    Directory of Open Access Journals (Sweden)

    Berta Martín-López

    Full Text Available Ecosystem service assessments have increasingly been used to support environmental management policies, mainly based on biophysical and economic indicators. However, few studies have coped with the social-cultural dimension of ecosystem services, despite being considered a research priority. We examined how ecosystem service bundles and trade-offs emerge from diverging social preferences toward ecosystem services delivered by various types of ecosystems in Spain. We conducted 3,379 direct face-to-face questionnaires in eight different case study sites from 2007 to 2011. Overall, 90.5% of the sampled population recognized the ecosystem's capacity to deliver services. Formal studies, environmental behavior, and gender variables influenced the probability of people recognizing the ecosystem's capacity to provide services. The ecosystem services most frequently perceived by people were regulating services; of those, air purification held the greatest importance. However, statistical analysis showed that socio-cultural factors and the conservation management strategy of ecosystems (i.e., National Park, Natural Park, or a non-protected area have an effect on social preferences toward ecosystem services. Ecosystem service trade-offs and bundles were identified by analyzing social preferences through multivariate analysis (redundancy analysis and hierarchical cluster analysis. We found a clear trade-off among provisioning services (and recreational hunting versus regulating services and almost all cultural services. We identified three ecosystem service bundles associated with the conservation management strategy and the rural-urban gradient. We conclude that socio-cultural preferences toward ecosystem services can serve as a tool to identify relevant services for people, the factors underlying these social preferences, and emerging ecosystem service bundles and trade-offs.

  3. Principal bundles on the projective line

    Indian Academy of Sciences (India)

    M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

    LetX be a complete nonsingular curve over the algebraic closurek ofk andGa reductive group over k. Let E → X be a principal G-bundle on X. E is said to be semistable if, for every reduction of structure group EP ⊂ E to a maximal parabolic subgroup P of G, we have degree EP (p) ≤ 0, where p is the Lie algebra of P and EP ...

  4. Spanning forests and the vector bundle Laplacian

    OpenAIRE

    Kenyon, Richard

    2011-01-01

    The classical matrix-tree theorem relates the determinant of the combinatorial Laplacian on a graph to the number of spanning trees. We generalize this result to Laplacians on one- and two-dimensional vector bundles, giving a combinatorial interpretation of their determinants in terms of so-called cycle rooted spanning forests (CRSFs). We construct natural measures on CRSFs for which the edges form a determinantal process. ¶ This theory gives a natural generalization of the spanning tre...

  5. Uncovering Ecosystem Service Bundles through Social Preferences

    Science.gov (United States)

    Martín-López, Berta; Iniesta-Arandia, Irene; García-Llorente, Marina; Palomo, Ignacio; Casado-Arzuaga, Izaskun; Amo, David García Del; Gómez-Baggethun, Erik; Oteros-Rozas, Elisa; Palacios-Agundez, Igone; Willaarts, Bárbara; González, José A.; Santos-Martín, Fernando; Onaindia, Miren; López-Santiago, Cesar; Montes, Carlos

    2012-01-01

    Ecosystem service assessments have increasingly been used to support environmental management policies, mainly based on biophysical and economic indicators. However, few studies have coped with the social-cultural dimension of ecosystem services, despite being considered a research priority. We examined how ecosystem service bundles and trade-offs emerge from diverging social preferences toward ecosystem services delivered by various types of ecosystems in Spain. We conducted 3,379 direct face-to-face questionnaires in eight different case study sites from 2007 to 2011. Overall, 90.5% of the sampled population recognized the ecosystem’s capacity to deliver services. Formal studies, environmental behavior, and gender variables influenced the probability of people recognizing the ecosystem’s capacity to provide services. The ecosystem services most frequently perceived by people were regulating services; of those, air purification held the greatest importance. However, statistical analysis showed that socio-cultural factors and the conservation management strategy of ecosystems (i.e., National Park, Natural Park, or a non-protected area) have an effect on social preferences toward ecosystem services. Ecosystem service trade-offs and bundles were identified by analyzing social preferences through multivariate analysis (redundancy analysis and hierarchical cluster analysis). We found a clear trade-off among provisioning services (and recreational hunting) versus regulating services and almost all cultural services. We identified three ecosystem service bundles associated with the conservation management strategy and the rural-urban gradient. We conclude that socio-cultural preferences toward ecosystem services can serve as a tool to identify relevant services for people, the factors underlying these social preferences, and emerging ecosystem service bundles and trade-offs. PMID:22720006

  6. A palladium-doped ceria@carbon core-sheath nanowire network: a promising catalyst support for alcohol electrooxidation reactions

    Science.gov (United States)

    Tan, Qiang; Du, Chunyu; Sun, Yongrong; Du, Lei; Yin, Geping; Gao, Yunzhi

    2015-08-01

    A novel palladium-doped ceria and carbon core-sheath nanowire network (Pd-CeO2@C CSNWN) is synthesized by a template-free and surfactant-free solvothermal process, followed by high temperature carbonization. This hierarchical network serves as a new class of catalyst support to enhance the activity and durability of noble metal catalysts for alcohol oxidation reactions. Its supported Pd nanoparticles, Pd/(Pd-CeO2@C CSNWN), exhibit >9 fold increase in activity toward the ethanol oxidation over the state-of-the-art Pd/C catalyst, which is the highest among the reported Pd systems. Moreover, stability tests show a virtually unchanged activity after 1000 cycles. The high activity is mainly attributed to the superior oxygen-species releasing capability of Pd-doped CeO2 nanowires by accelerating the removal of the poisoning intermediate. The unique interconnected one-dimensional core-sheath structure is revealed to facilitate immobilization of the metal catalysts, leading to the improved durability. This core-sheath nanowire network opens up a new strategy for catalyst performance optimization for next-generation fuel cells.A novel palladium-doped ceria and carbon core-sheath nanowire network (Pd-CeO2@C CSNWN) is synthesized by a template-free and surfactant-free solvothermal process, followed by high temperature carbonization. This hierarchical network serves as a new class of catalyst support to enhance the activity and durability of noble metal catalysts for alcohol oxidation reactions. Its supported Pd nanoparticles, Pd/(Pd-CeO2@C CSNWN), exhibit >9 fold increase in activity toward the ethanol oxidation over the state-of-the-art Pd/C catalyst, which is the highest among the reported Pd systems. Moreover, stability tests show a virtually unchanged activity after 1000 cycles. The high activity is mainly attributed to the superior oxygen-species releasing capability of Pd-doped CeO2 nanowires by accelerating the removal of the poisoning intermediate. The unique

  7. Bundling harvester; Harvennuspuun automaattisen nippukorjausharvesterin kehittaeminen

    Energy Technology Data Exchange (ETDEWEB)

    Koponen, K [Eko-Log Oy, Kuopio (Finland)

    1997-12-01

    The starting point of the project was to design and construct, by taking the silvicultural point of view into account, a harvesting and processing system especially for energy-wood, containing manually driven bundling harvester, automating of the harvester, and automated loading. The equipment forms an ideal method for entrepreneur`s-line harvesting. The target is to apply the system also for owner`s-line harvesting. The profitability of the system promotes the utilisation of the system in both cases. The objectives of the project were: to construct a test equipment and prototypes for all the project stages, to carry out terrain and strain tests in order to examine the usability and durability, as well as the capacity of the machine, to test the applicability of the Eko-Log system in simultaneous harvesting of energy and pulp woods, and to start the marketing and manufacturing of the products. The basic problems of the construction of the bundling harvester have been solved using terrain-tests. The prototype machine has been shown to be operable. Loading of the bundles to form sufficiently economically transportable loads has been studied, and simultaneously, the branch-biomass has been tried to be utilised without loosing the profitability of transportation. The results have been promising, and will promote the profitable utilisation of wood-energy. (orig.)

  8. Experimental heat transfer in tube bundle

    International Nuclear Information System (INIS)

    Khattab, M.; Mariy, A.; Habib, M.

    1983-01-01

    Previous work has looked for the problem of heat transfer with flow parallel to rod bundle either by treating each rod individually as a separate channel or by treating the bundle as one unit. The present work will consider the existence of both the central and corner rods simultaneously inside the cluster itself under the same working conditions. The test section is geometrically similar to the fuel assembly of the Egyptian Research Reactor-1. The hydro-thermal performance of bundle having 16 - stainless steel tubes arranged in square array of 1.5 pitch to diameter ratio is investigated. Surface temperature and pressure distributions are determined. Average heat transfer coefficient for both central and corner tubes are correlated. Also, pressure drop and friction factor correlations are predicted. The maximum experimental range of the measured parameters are determined in the nonboiling region at 1400 Reynolds number and 3.64 W/cm 2 . It is found that the average heat transfer coefficient of the central tube is higher than that of the corner tube by 27%. Comparison with the previous work shows satisfactory agreement particularly with the circular tubes correlation - Dittus et al. - at 104 Reynolds number

  9. Study of fuel bundle geometry on inter subchannel flow in a 19 pin wire wrapped bundle

    International Nuclear Information System (INIS)

    Naveen Raj, M.; Velusamy, D.K.

    2015-01-01

    In typical sodium cooled fast reactor (SFR) fuel pin bundle, gap between the pins is maintained by helically wound wire wrap around each pin. The presence of wire induces large inter-subchannel transverse flow, eventually promoting mixing and heat transfer. The magnitude of the transverse flow is highly dependent on the various pin-bundle dimensions. Appropriate modeling of these transverse flows in subchannel codes is necessary to predict realistic temperature distribution in pin bundle. Hence, detailed parametric study of transverse flow on pin-bundle geometric parameters has been conducted. The parameters taken for the present study are pin diameter, wire diameter, helical wire pitch and edge gap. Towards this 3-D computational fluid dynamic analysis on a structured mesh of 19 pin bundle is carried out using k-epsilon turbulence model. Periodic oscillations along the primacy flow direction were found in subchannel transverse flow and peripheral pin clad temperatures with periodicity over one pitch length. Based on parametric studies, correlations for transverse flow in central subchannels are proposed. (author)

  10. Bundled payment fails to gain a foothold In California: the experience of the IHA bundled payment demonstration.

    Science.gov (United States)

    Ridgely, M Susan; de Vries, David; Bozic, Kevin J; Hussey, Peter S

    2014-08-01

    To determine whether bundled payment could be an effective payment model for California, the Integrated Healthcare Association convened a group of stakeholders (health plans, hospitals, ambulatory surgery centers, physician organizations, and vendors) to develop, through a consensus process, the methods and means of implementing bundled payment. In spite of a high level of enthusiasm and effort, the pilot did not succeed in its goal to implement bundled payment for orthopedic procedures across multiple payers and hospital-physician partners. An evaluation of the pilot documented a number of barriers, such as administrative burden, state regulatory uncertainty, and disagreements about bundle definition and assumption of risk. Ultimately, few contracts were signed, which resulted in insufficient volume to test hypotheses about the impact of bundled payment on quality and costs. Although bundled payment failed to gain a foothold in California, the evaluation provides lessons for future bundled payment initiatives. Project HOPE—The People-to-People Health Foundation, Inc.

  11. The magnetized sheath of a dusty plasma with grains size distribution

    International Nuclear Information System (INIS)

    Ou, Jing; Gan, Chunyun; Lin, Binbin; Yang, Jinhong

    2015-01-01

    The structure of a plasma sheath in the presence of dust grains size distribution (DGSD) is investigated in the multi-fluid framework. It is shown that effect of the dust grains with different sizes on the sheath structure is a collective behavior. The spatial distributions of electric potential, the electron and ion densities and velocities, and the dust grains surface potential are strongly affected by DGSD. The dynamics of dust grains with different sizes in the sheath depend on not only DGSD but also their radius. By comparison of the sheath structure, it is found that under the same expected value of DGSD condition, the sheath length is longer in the case of lognormal distribution than that in the case of uniform distribution. In two cases of normal and lognormal distributions, the sheath length is almost equal for the small variance of DGSD, and then the difference of sheath length increases gradually with increase in the variance

  12. Fast, kinetically self-consistent simulation of RF modulated plasma boundary sheaths

    International Nuclear Information System (INIS)

    Shihab, Mohammed; Ziegler, Dennis; Brinkmann, Ralf Peter

    2012-01-01

    A mathematical model is presented which enables the efficient, kinetically self-consistent simulation of RF modulated plasma boundary sheaths in all technically relevant discharge regimes. It is defined on a one-dimensional geometry where a Cartesian x-axis points from the electrode or wall at x E ≡ 0 towards the plasma bulk. An arbitrary endpoint x B is chosen ‘deep in the bulk’. The model consists of a set of kinetic equations for the ions, Boltzmann's relation for the electrons and Poisson's equation for the electrical field. Boundary conditions specify the ion flux at x B and a periodically—not necessarily harmonically—modulated sheath voltage V(t) or sheath charge Q(t). The equations are solved in a statistical sense. However, it is not the well-known particle-in-cell (PIC) scheme that is employed, but an alternative iterative algorithm termed ensemble-in-spacetime (EST). The basis of the scheme is a discretization of the spacetime, the product of the domain [x E , x B ] and the RF period [0, T]. Three modules are called in a sequence. A Monte Carlo module calculates the trajectories of a large set of ions from their start at x B until they reach the electrode at x E , utilizing the potential values on the nodes of the spatio-temporal grid. A harmonic analysis module reconstructs the Fourier modes n im (x) of the ion density n i (x, t) from the calculated trajectories. A field module finally solves the Boltzmann-Poisson equation with the calculated ion densities to generate an updated set of potential values for the spatio-temporal grid. The iteration is started with the potential values of a self-consistent fluid model and terminates when the updates become sufficiently small, i.e. when self-consistency is achieved. A subsequent post-processing determines important quantities, in particular the phase-resolved and phase-averaged values of the ion energy and angular distributions and the total energy flux at the electrode. A drastic reduction of the

  13. Enhanced target normal sheath acceleration of protons from intense laser interaction with a cone-tube target

    Directory of Open Access Journals (Sweden)

    K. D. Xiao

    2016-01-01

    Full Text Available Laser driven proton acceleration is proposed to be greatly enhanced by using a cone-tube target, which can be easily manufactured by current 3D-print technology. It is observed that energetic electron bunches are generated along the tube and accelerated to a much higher temperature by the combination of ponderomotive force and longitudinal electric field which is induced by the optical confinement of the laser field. As a result, a localized and enhanced sheath field is produced at the rear of the target and the maximum proton energy is about three-fold increased based on the two-dimentional particle-in-cell simulation results. It is demonstrated that by employing this advanced target scheme, the scaling of the proton energy versus the laser intensity is much beyond the normal target normal sheath acceleration (TNSA case.

  14. Co-electrospinning fabrication and photocatalytic performance of TiO2/SiO2 core/sheath nanofibers with tunable sheath thickness

    International Nuclear Information System (INIS)

    Cao, Houbao; Du, Pingfan; Song, Lixin; Xiong, Jie; Yang, Junjie; Xing, Tonghai; Liu, Xin; Wu, Rongrong; Wang, Minchao; Shao, Xiaoli

    2013-01-01

    Graphical abstract: - Highlights: • The core–sheath TiO 2 /SiO 2 nanofibers were fabricated by co-electrospinning technique. • The catalytic property of nanofibers with different sheath thickness was studied. • The potential methods of improving catalytic efficiency are suggested. - Abstract: In this paper, core/sheath TiO 2 /SiO 2 nanofibers with tunable sheath thickness were directly fabricated via a facile co-electrospinning technique with subsequent calcination at 500 °C. The morphologies and structures of core/sheath TiO 2 /SiO 2 nanofibers were characterized by TGA, FESEM, TEM, FTIR, XPS and BET. It was found that the 1D core/sheath nanofibers are made up of anatase–rutile TiO 2 core and amorphous SiO 2 sheath. The influences of SiO 2 sheath and its thickness on the photoreactivity were evaluated by observing photo-degradation of methylene blue aqueous solution under the irradiation of UV light. Compared with pure TiO 2 nanofibers, the core/sheath TiO 2 /SiO 2 nanofibers performed a better catalytic performance. That was attributed to not only efficient separation of hole–electron pairs resulting from the formation of heterojunction but also larger surface area and surface silanol group which will be useful to provide higher capacity for oxygen adsorption to generate more hydroxyl radicals. And the optimized core/sheath TiO 2 /SiO 2 nanofibers with a sheath thickness of 37 nm exhibited the best photocatalytic performance

  15. Nanotube bundle oscillators: Carbon and boron nitride nanostructures

    International Nuclear Information System (INIS)

    Thamwattana, Ngamta; Hill, James M.

    2009-01-01

    In this paper, we investigate the oscillation of a fullerene that is moving within the centre of a bundle of nanotubes. In particular, certain fullerene-nanotube bundle oscillators, namely C 60 -carbon nanotube bundle, C 60 -boron nitride nanotube bundle, B 36 N 36 -carbon nanotube bundle and B 36 N 36 -boron nitride nanotube bundle are studied using the Lennard-Jones potential and the continuum approach which assumes a uniform distribution of atoms on the surface of each molecule. We address issues regarding the maximal suction energies of the fullerenes which lead to the generation of the maximum oscillation frequency. Since bundles are also found to comprise double-walled nanotubes, this paper also examines the oscillation of a fullerene inside a double-walled nanotube bundle. Our results show that the frequencies obtained for the oscillation within double-walled nanotube bundles are slightly higher compared to those of single-walled nanotube bundle oscillators. Our primary purpose here is to extend a number of established results for carbon to the boron nitride nanostructures.

  16. Dimensional measurement of fresh fuel bundle for CANDU reactor

    International Nuclear Information System (INIS)

    Jo, Chang Keun; Cho, Moon Sung; Suk, Ho Chun; Koo, Dae Seo; Jun, Ji Su; Jung, Jong Yeob

    2005-01-01

    This report describes the results of the dimensional measurement of fresh fuel bundles for the CANDU reactor in order to estimate the integrity of fuel bundle in two-phase flow in the CANDU-6 fuel channel. The dimensional measurements of fuel bundles are performed by using the 'CANDU Fuel In-Bay Inspection and Dimensional Measurement System', which was developed by this project. The dimensional measurements are done from February 2004 to March 2004 in the CANDU fuel storage of KNFC for the 36 fresh fuel bundles, which are produced by KNFC and are waiting for the delivery to the Wolsong-3 plant. The detail items of dimensional measurements are included fuel rod and bearing pad profiles of the outer ring in fuel bundle, diameter of fuel bundle, bowing of fuel bundle, fuel rod length, and surface profile of end plate profile. The measurement data will be compared with those of the post-irradiated bundles cooled in Wolsong-3 NPP spent fuel pool by using the same bundles and In-Bay Measurement System. So, this analysis of data will be applied for the evaluation of fuel bundle integrity in two-phase flow of the CANDU-6 fuel channel

  17. Zircaloy-sheathed element rods fitted with thermo-couples

    International Nuclear Information System (INIS)

    Bernardy de Sigoyer, B.; Jacques, F.; Thome, P.

    1963-01-01

    In order to carry out thermal conductivity measurements on UO 2 in conditions similar to those under which fuel rods are used, it was necessary to measure the temperature at the interior of a fuel element sheathed in zircaloy. The temperatures are taken with Thermocoax type thermocouples, that is to say fitted with a very thin sheath of stainless steel or Inconel. It is known also that fusion welding of zircaloy onto stainless steel is impossible and that high temperature welded joints are very difficult because of their aggressiveness. The technique used consists in brazing the thermocouples to relatively large stainless steel parts and then joining these plugs by electron bombardment welding to diffused stainless steel-zircaloy couplings. The properties of these diffused couplings and of the brazed joints were studied; the various stages in the fabrication of the containers are also described. (authors) [fr

  18. Moisture Durability with Vapor-Permeable Insulating Sheathing

    Energy Technology Data Exchange (ETDEWEB)

    Lepage, R. [Building Science Corporation, Somerville, MA (United States); Lstiburek, J. [Building Science Corporation, Somerville, MA (United States)

    2013-09-01

    Exterior sheathing insulation is an effective strategy in increasing the overall R-value of wall assemblies; other benefits include decreasing the effects of thermal bridging and increasing the moisture durability of the built assembly. Vapor-permeable exterior insulation, such as mineral board or expanded polystyrene foam, are one such product that may be used to achieve these benefits. However, uncertainty exists on the effects of inward driven moisture and the interaction of increased sheathing temperatures on the moisture durability of the edifice. To address these concerns, Building Science Corporation (BSC) conducted a series of hygrothermal models for cities representing a range of different climate zones. This report describes the research project, key research questions, and the procedures utilized to analyse the problems.

  19. Moisture Durability with Vapor-Permeable Insulating Sheathing

    Energy Technology Data Exchange (ETDEWEB)

    Lepage, R. [Building Science Corporation, Somerville, MA (United States); Lstiburek, J. [Building Science Corporation, Somerville, MA (United States)

    2013-09-01

    Exterior sheathing insulation is an effective strategy in increasing the overall R-value of wall assemblies; other benefits include decreasing the effects of thermal bridging and increasing the moisture durability of the built assembly. Vapor-permeable exterior insulation, such as mineral board or expanded polystyrene foam, are one such product that may be used to achieve these benefits. However,uncertainty exists on the effects of inward driven moisture and the interaction of increased sheathing temperatures on the moisture durability of the edifice. To address these concerns, Building Science Corporation (BSC) conducted a series of hygrothermal models for cities representing a range of different climate zones. This report describes the research project, key research questions, and theprocedures utilized to analyse the problems.

  20. Sheath structure in negative ion sources for fusion (invited)

    International Nuclear Information System (INIS)

    McAdams, R.; King, D. B.; Surrey, E.; Holmes, A. J. T.

    2012-01-01

    In fusion negative ion sources, the negative ions are formed on the caesiated plasma grid predominantly by hydrogen atoms from the plasma. The space charge of the negative ions leaving the wall is not fully compensated by incoming positive ions and at high enough emission a virtual cathode is formed. This virtual cathode limits the flux of negative ions transported across the sheath to the plasma. A 1D collisionless model of the sheath is presented taking into account the virtual cathode. The model will be applied to examples of the ion source operation. Extension of the model to the bulk plasma shows good agreement with experimental data. A possible role for fast ions is discussed.

  1. Out-of-pile fatigue tests on Zircaloy CANDU sheaths

    International Nuclear Information System (INIS)

    Roth, Maria; Ciocanescu, Marin; Gheorghiu, Constantin; Pitigoi, Vasile; Ducu, Catalin; Malinovschi, Viorel

    2005-01-01

    The paper outlines the achievements in the nuclear research field of cooperation on Nuclear Fuel performed as part of the collaboration under the Memorandum of Understanding, settled between Atomic Energy of Canada Limited (AECL) and Institute for Nuclear Research (ICN), The sheath behavior was simulated using out-of-pile fatigue tests, in conditions identical with those met during the operation in power cycling of CANDU reactor, except for irradiation. A special test rig, designed and carried-out at ICN ensured the experimental requirements according to the Canadian testing procedure. The description of the experimental setup and monitoring of testing parameters were also done. The fatigue life time, expressed as number of cycles to rupture (N), was measured as a function of the total strain amplitude (e) induced in the Zircaloy-4 sheath samples. Strain-Life time fatigue dependence (e-N) under low cycle fatigue conditions was also verified using the Coffin-Manson correlation. (authors)

  2. Retroperitoneal Malignant Peripheral Nerve Sheath Tumour: A Rare Case Report.

    Science.gov (United States)

    Deger, Ayse Nur; Bayar, Mehmet Akif; Caydere, Muzaffer; Deger, Hakki; Tayfur, Mahir

    2015-09-01

    Malignant nerve sheath tumours (MPNST) are rare neoplasias and retroperitoneal cases are fairly rare and clinically difficult to be detected, but they are very agressive neoplasias. MPNST are frequently seen in head, neck and upper extremities. In patients with NF1; MPNST, a poor-prognostic lesion, may result from a malignant degeneration of a former plexiform neurofibroma. It is necessary to be aware of a potential malignancy in patients diagnosed with plexiform neurofibroma. We present a 21-year-old female with a diagnosis of MPNST. The patient was admited to the hospital because of a tumour in the subcutaneous region on her left buttock. The surgeon's clinical diagnosis was lipoma. After the pathological examination of biopsy specimen, the lesion was identified as "plexiform neurofibroma" and then the patient was diagnosed with Neurofibromatosis Type 1 (NF1). Simultaneously, another mass on the retroperitoneal region was identified as malignant peripheral nerve sheath tumour (MPNST).

  3. Studies of RF sheaths and diagnostics on IShTAR

    Energy Technology Data Exchange (ETDEWEB)

    Crombé, K., E-mail: Kristel.Crombe@UGent.be [Department of Applied Physics, Ghent University, Ghent (Belgium); LPP-ERM/KMS, Royal Military Academy, Brussels (Belgium); Devaux, S.; Faudot, E.; Heuraux, S.; Moritz, J. [YIJL, UMR7198 CNRS-Université de Lorraine, Nancy (France); D’Inca, R.; Faugel, H.; Fünfgelder, H.; Jacquot, J.; Ochoukov, R. [Max-Planck-Institut für Plasmaphysik, Garching (Germany); Louche, F.; Tripsky, M.; Van Eester, D.; Wauters, T. [LPP-ERM/KMS, Royal Military Academy, Brussels (Belgium); Noterdaeme, J.-M. [Department of Applied Physics, Ghent University, Ghent (Belgium); Max-Planck-Institut für Plasmaphysik, Garching (Germany)

    2015-12-10

    IShTAR (Ion cyclotron Sheath Test ARrangement) is a linear magnetised plasma test facility for RF sheaths studies at the Max-Planck-Institut für Plasmaphysik in Garching. In contrast to a tokamak, a test stand provides more liberty to impose the parameters and gives better access for the instrumentation and antennas. The project will support the development of diagnostic methods for characterising RF sheaths and validate and improve theoretical predictions. The cylindrical vacuum vessel has a diameter of 1 m and is 1.1 m long. The plasma is created by an external cylindrical plasma source equipped with a helical antenna that has been designed to excite the m=1 helicon mode. In inductive mode, plasma densities and electron temperatures have been characterised with a planar Langmuir probe as a function of gas pressure and input RF power. A 2D array of RF compensated Langmuir probes and a spectrometer are planned. A single strap RF antenna has been designed; the plasma-facing surface is aligned to the cylindrical plasma to ease the modelling. The probes will allow direct measurements of plasma density profiles in front of the RF antenna, and thus a detailed study of the density modifications induced by RF sheaths, which influences the coupling. The RF antenna frequency has been chosen to study different plasma wave interactions: the accessible plasma density range includes an evanescent and propagative behaviour of slow or fast waves, and allows the study of the effect of the lower hybrid resonance layer.

  4. Comparative Oncogenomics for Peripheral Nerve Sheath Cancer Gene Discovery

    Science.gov (United States)

    2015-06-01

    and MPNSTs by determining whether these same genes are mutated in human tumors. 15. SUBJECT TERMS Nothing listed 16. SECURITY CLASSIFICATION OF: 17...sheath tumour (MPNST). In: Louis DNO, H.;Wiestler,O.D.;Cavenee,W.K., editor. WHO Classification of Tumours of the Central Nervous System. Lyon: IARC...Location Sex Major or Micro WHO Grade H6 DRG Male Major IV H9 Trigeminal ganglion Female Major III H17 Trigeminal ganglion Male Major II H19 Sciatic

  5. Comprehensive Study of Plasma-Wall Sheath Transport Phenomena

    Science.gov (United States)

    2016-10-26

    the floating potential of wall material samples immersed in a low-temperature plasma were studied. Hysteresis is found to be due to secondary electron...continued research into plasma sheath physics. Hysteresis effects observed in the floating potential of wall material samples immersed in a low... Journal of Applied Physics, Volume 119, March 2016, pp. 113305 1-5. DISTRIBUTION A: Distribution approved for public release. 8 Figure 2

  6. A rare case of bilateral optic nerve sheath meningioma

    Directory of Open Access Journals (Sweden)

    Somen Misra

    2014-01-01

    Full Text Available A 60-year-old female presented with gradual, painless, progressive diminution of vision, and progressive proptosis of left eye since 7 years. Ophthalmological examination revealed mild proptosis and total optic atrophy in the left eye. Magnetic resonance imaging (MRI and computed tomography (CT brain with orbit showed bilateral optic nerve sheath meningioma (ONSM involving the intracranial, intracanalicular, intraorbital part of the optic nerve extending up to optic chiasma and left cavernous sinus.

  7. Stability of Picard bundle over moduli space of stable vector bundles ...

    Indian Academy of Sciences (India)

    Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

    Since the morphism ϕ is given by the universal property of the moduli space, the pullback of the universal bundle E on X × M to X × P by the map idX × ϕ is isomorphic (up to a twist by a line bundle coming from P) to ˜E. In other words, there is an integer k such that. 0 −→ (idX × ϕ)∗E −→ W ⊠ OP (k) −→ Ox×P (k + 1) −→ 0.

  8. A fully kinetic, self-consistent particle simulation model of the collisionless plasma--sheath region

    International Nuclear Information System (INIS)

    Procassini, R.J.; Birdsall, C.K.; Morse, E.C.

    1990-01-01

    A fully kinetic particle-in-cell (PIC) model is used to self-consistently determine the steady-state potential profile in a collisionless plasma that contacts a floating, absorbing boundary. To balance the flow of particles to the wall, a distributed source region is used to inject particles into the one-dimensional system. The effect of the particle source distribution function on the source region and collector sheath potential drops, and particle velocity distributions is investigated. The ion source functions proposed by Emmert et al. [Phys. Fluids 23, 803 (1980)] and Bissell and Johnson [Phys. Fluids 30, 779 (1987)] (and various combinations of these) are used for the injection of both ions and electrons. The values of the potential drops obtained from the PIC simulations are compared to those from the theories of Emmert et al., Bissell and Johnson, and Scheuer and Emmert [Phys. Fluids 31, 3645 (1988)], all of which assume that the electron density is related to the plasma potential via the Boltzmann relation. The values of the source region and total potential drop are found to depend on the choice of the electron source function, as well as the ion source function. The question of an infinite electric field at the plasma--sheath interface, which arises in the analyses of Bissell and Johnson and Scheuer and Emmert, is also addressed

  9. Cilia-like structures anchor the amphioxus notochord to its sheath.

    Science.gov (United States)

    Bočina, Ivana; Ljubešić, Nikola; Saraga-Babić, Mirna

    2011-01-01

    Body stiffness is important during undulatory locomotion in fish. In amphioxus, the myosepta play an important role in transmission of muscular forces to the notochord. In order to define the specific supporting role of the notochord in amphioxus during locomotion, the ultrastructure of 10 adult amphioxus specimens was analyzed using transmission electron microscopy. Numerous cilia-like structures were found on the surface of each notochordal cell at the sites of their attachment to the notochordal sheath. Ultrastructurally, these structures consisted of the characteristic arrangement of peripheral and central microtubular doublets and were anchored to the inner layer of the notochordal sheath. Immunohistochemically, a positive reaction to applied dynein and β-tubulin antibodies characterized the area of the cilia-like structures. We propose that reduced back-and-forth movements of the cilia-like structures might contribute to the flow of the fluid content inside the notochord, thus modulating the stiffness of the amphioxus body during its undulatory locomotion. Copyright © 2009 Elsevier GmbH. All rights reserved.

  10. Contribution to the physical study of sheath failure detections

    International Nuclear Information System (INIS)

    Mangin, Jean-Paul

    1968-11-01

    As the study of an installation aimed at the detection of sheath failure requires the knowledge of a great number of data related to all the fields of nuclear technology (fission mechanisms, sheath failure mechanisms, recoil of fission products, distribution of the heat transfer fluid in the reactor, techniques of measurement of beta and gamma neutrons, nuclear safety, and so on), this report aims at highlighting some specific issues, more particularly those related to sensors based on delayed neutrons. After having recalled the principles of sheath failure detection, the author presents the various aspects of the study of the formation of fission products and of their passage into the heat transfer fluid: detection by using delayed neutrons, detection by electrostatic collection, passage of fuel fission products into the coolant (recoil, corrosion, gaseous diffusion in the fuel), formation of fission products in the fuel (fission product efficiency). He reports the study of the transport of fission products by the coolant from their place of birth to the place of measurement. He presents the system of measurement by detection of delayed neutrons and by electrostatic collection, reports a sensitivity calculation, a background noise assessment, the determination of detection threshold, and the application of sensitivity and detection thresholds calculations [fr

  11. Unirradiated UO2 in irradiated zirconium alloy sheathing

    International Nuclear Information System (INIS)

    MacDonald, R.D.; Hardy, D.G.; Hunt, C.E.L.; Scoberg, J.A.

    1979-07-01

    Zircaloy-clad UO 2 fuel elements have defected in power reactors when element power outputs were raised significantly after a long irradiation at low power. We have irradiated fuel elements fabricated from fresh UO 2 pellets and zirconium alloy sheaths previously irradiated without fuel. This gave a fuel element with radiation-damaged low-ductility sheathing but with no fission products in the fuel. The elements were power boosted in-reactor to linear power outputs up to 84 kW/m for two five-day periods. No elements defected despite sheath strains of 0.82 percent at circumferential ridge postions. Half of these elements were subsequently soaked at low power to build up the fission product inventory in the fuel and then power boosted to 63 kW/m for a third time. Two elements defected on this final boost. We conclude that these defects were caused by fission product induced stress-corrosion cracking and that this mechanism plays an importent role in power reactor fuel defects. (auth)

  12. Measurements of the sheath potential in low density plasmas

    International Nuclear Information System (INIS)

    Bradley, J.W.; Khamis, R.A.; Sanduk, M.I.; Elliott, J.A.; Rusbridge, M.G.

    1992-01-01

    We have measured the sheath potential around a probe in a range of different plasma conditions in the UMIST, University of Manchester Institute of Science and Technology, quadrupole GOLUX and in a related experiment in which the plasma expands freely to supersonic velocity. In the latter case, the sheath potential agrees well with an appropriately modified form of the usual expression for a field-free plasma, for both hydrogen and argon plasmas. In GOLUX, however, the sheath potential is found to be significantly less than the accepted value, even when the magnetic field is taken into account. For the slow moving plasma in the outer part of the quadrupole confining field, we present both theoretical and experimental results showing that the reduction is due to truncation of the electron velocity distribution as the probe drains electrons from a closed flux tube faster than they can be replaced. In the central hot plasma, however, this explanation cannot apply. Here, the plasma is moving at about sonic speed and magnetic effects are weak. Nevertheless, the results are significantly different from both in the field free experiment. (author)

  13. Malignant peripheral nerve sheath tumor of the tongue with an unusual pattern of recurrence

    Directory of Open Access Journals (Sweden)

    Soumyajit Roy, MD

    2017-06-01

    Full Text Available Malignant peripheral nerve sheath tumor (MPNST of oral cavity is an extremely uncommon malignancy. Less than 15 cases have been reported since 1973 though none of them describes a distant metastasis. We present a rare case of MPNST of the tongue who presented with features of hypoglossal nerve palsy. Incisional biopsy showed a malignant spindle cell tumor in the sub-epithelial connective tissue. The tumor cells were immune-positive for S-100. He underwent surgery followed by adjuvant chemo-radiation. Later the disease recurred in the form of isolated pelvic bone metastasis. Palliative chemotherapy was offered to him. With this case report we intend to refer to such unusual presentation and pattern of recurrence in a MPNST of tongue.

  14. Influence of Bundle Diameter and Attachment Point on Kinematic Behavior in Double Bundle Anterior Cruciate Ligament Reconstruction Using Computational Model

    Directory of Open Access Journals (Sweden)

    Oh Soo Kwon

    2014-01-01

    Full Text Available A protocol to choose the graft diameter attachment point of each bundle has not yet been determined since they are usually dependent on a surgeon’s preference. Therefore, the influence of bundle diameters and attachment points on the kinematics of the knee joint needs to be quantitatively analyzed. A three-dimensional knee model was reconstructed with computed tomography images of a 26-year-old man. Based on the model, models of double bundle anterior cruciate ligament (ACL reconstruction were developed. The anterior tibial translations for the anterior drawer test and the internal tibial rotation for the pivot shift test were investigated according to variation of bundle diameters and attachment points. For the model in this study, the knee kinematics after the double bundle ACL reconstruction were dependent on the attachment point and not much influenced by the bundle diameter although larger sized anterior-medial bundles provided increased stability in the knee joint. Therefore, in the clinical setting, the bundle attachment point needs to be considered prior to the bundle diameter, and the current selection method of graft diameters for both bundles appears justified.

  15. Exploring the membrane fusion mechanism through force-induced disassembly of HIV-1 six-helix bundle

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Kai [Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Beijing Key Laboratory of Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Yong [Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Beijing Key Laboratory of Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Lou, Jizhong, E-mail: jlou@ibp.ac.cn [Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Beijing Key Laboratory of Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China)

    2016-05-13

    Enveloped virus, such as HIV-1, employs membrane fusion mechanism to invade into host cell. HIV-1 gp41 ectodomain uses six-helix bundle configuration to accomplish this process. Using molecular dynamic simulations, we confirmed the stability of this six-helix bundle by showing high occupancy of hydrogen bonds and hydrophobic interactions. Key residues and interactions important for the bundle integration were characterized by force-induced unfolding simulations of six-helix bundle, exhibiting the collapse order of these groups of interactions. Moreover, our results in some way concerted with a previous theory that the formation of coiled-coil choose a route which involved cooperative interactions between the N-terminal and C-terminal helix. -- Highlights: •Unfolding of HIV-1 gp41 six-helix bundle is studied by molecular dynamics simulations. •Specific interactions responsible for the stability of HIV-1 envelope post-fusion conformation were identified. •The gp41 six-helix bundle transition inducing membrane fusion might be a cooperative process of the three subunits.

  16. A Tannakian approach to dimensional reduction of principal bundles

    Science.gov (United States)

    Álvarez-Cónsul, Luis; Biswas, Indranil; García-Prada, Oscar

    2017-08-01

    Let P be a parabolic subgroup of a connected simply connected complex semisimple Lie group G. Given a compact Kähler manifold X, the dimensional reduction of G-equivariant holomorphic vector bundles over X × G / P was carried out in Álvarez-Cónsul and García-Prada (2003). This raises the question of dimensional reduction of holomorphic principal bundles over X × G / P. The method of Álvarez-Cónsul and García-Prada (2003) is special to vector bundles; it does not generalize to principal bundles. In this paper, we adapt to equivariant principal bundles the Tannakian approach of Nori, to describe the dimensional reduction of G-equivariant principal bundles over X × G / P, and to establish a Hitchin-Kobayashi type correspondence. In order to be able to apply the Tannakian theory, we need to assume that X is a complex projective manifold.

  17. Analytical prediction of turbulent friction factor for a rod bundle

    International Nuclear Information System (INIS)

    Bae, Jun Ho; Park, Joo Hwan

    2011-01-01

    An analytical calculation has been performed to predict the turbulent friction factor in a rod bundle. For each subchannel constituting a rod bundle, the geometry parameters are analytically derived by integrating the law of the wall over each subchannel with the consideration of a local shear stress distribution. The correlation equations for a local shear stress distribution are supplied from a numerical simulation for each subchannel. The explicit effect of a subchannel shape on the geometry parameter and the friction factor is reported. The friction factor of a corner subchannel converges to a constant value, while the friction factor of a central subchannel steadily increases with a rod distance ratio. The analysis for a rod bundle shows that the friction factor of a rod bundle is largely affected by the characteristics of each subchannel constituting a rod bundle. The present analytic calculations well predict the experimental results from the literature with rod bundles in circular, hexagonal, and square channels.

  18. AC losses of single-core MgB{sub 2} wires with different metallic sheaths

    Energy Technology Data Exchange (ETDEWEB)

    Kováč, J., E-mail: elekjkov@savba.sk; Šouc, J.; Kováč, P.; Hušek, I.

    2015-12-15

    Highlights: • AC losses in single-core MgB{sub 2} wires with different metallic sheaths have been measured. • It has been shown that metallic sheath can affect the measured AC loss considerably. • GlidCop and Stainless Steel have negligible effect to the overall loss. • Strong contribution of eddy currents has been found in the wire with well conductive copper sheath. • Due to Monel sheath AC loss of MgB{sub 2} core is not visible. - Abstract: AC losses of single-core MgB{sub 2} superconductors with different metallic sheaths (Cu, GlidCop, stainless steel and Monel) have been measured and analyzed. These wires were exposed to external magnetic field with frequencies 72 and 144 Hz and amplitudes up to 0.1 T at temperatures ranged from 18 to 40 K. The obtained results have shown that applied metallic sheath can affect the measured AC loss considerably. In the case of GlidCop and Stainless Steel a negligible small effect of metallic sheath was observed. Strong contribution of eddy currents has been found in the wire with well conductive copper sheath. In the case of Monel sheath, the hysteresis loss of magnetic sheath is dominated and AC loss of MgB{sub 2} core is practically not visible.

  19. Studies on the transmission of sub-THz waves in magnetized inhomogeneous plasma sheath

    Science.gov (United States)

    Yuan, Kai; Shen, Linfang; Yao, Ming; Deng, Xiaohua; Chen, Zhou; Hong, Lujun

    2018-01-01

    There have been many studies on the sub-terahertz (sub-THz) wave transmission in reentry plasma sheaths. However, only some of them have paid attention to the transmission of sub-THz waves in magnetized plasma sheaths. In this paper, the transmission of sub-THz waves in both unmagnetized and magnetized reentry plasma sheaths was investigated. The impacts of temporal evolution of the plasma sheath on the wave transmission were studied. The transmission of "atmospheric window" frequencies in a magnetized plasma sheath was discussed in detail. According to the study, the power transmission rates (Tp) for the left hand circular (LHC) and the right hand circular modes in the magnetized plasma sheath are obviously higher and lower than those in the unmagnetized plasma sheath, respectively. The Tp of LHC mode increases with both wave frequency and external magnetic field strength. Also, the Tp of LHC mode in both magnetized and unmagnetized plasma sheaths varies with time due to the temporal evolution of the plasma sheath. Moreover, the performance of sub-THz waves in magnetized plasma sheath hints at a new approach to the "blackout" problem. The new approach, which is in the capability of modern technology, is to utilize the communication system operating at 140 GHz with an onboard magnet installed near the antenna.

  20. MODULAR BUNDLE ADJUSTMENT FOR PHOTOGRAMMETRIC COMPUTATIONS

    Directory of Open Access Journals (Sweden)

    N. Börlin

    2018-05-01

    Full Text Available In this paper we investigate how the residuals in bundle adjustment can be split into a composition of simple functions. According to the chain rule, the Jacobian (linearisation of the residual can be formed as a product of the Jacobians of the individual steps. When implemented, this enables a modularisation of the computation of the bundle adjustment residuals and Jacobians where each component has limited responsibility. This enables simple replacement of components to e.g. implement different projection or rotation models by exchanging a module. The technique has previously been used to implement bundle adjustment in the open-source package DBAT (Börlin and Grussenmeyer, 2013 based on the Photogrammetric and Computer Vision interpretations of Brown (1971 lens distortion model. In this paper, we applied the technique to investigate how affine distortions can be used to model the projection of a tilt-shift lens. Two extended distortion models were implemented to test the hypothesis that the ordering of the affine and lens distortion steps can be changed to reduce the size of the residuals of a tilt-shift lens calibration. Results on synthetic data confirm that the ordering of the affine and lens distortion steps matter and is detectable by DBAT. However, when applied to a real camera calibration data set of a tilt-shift lens, no difference between the extended models was seen. This suggests that the tested hypothesis is false and that other effects need to be modelled to better explain the projection. The relatively low implementation effort that was needed to generate the models suggest that the technique can be used to investigate other novel projection models in photogrammetry, including modelling changes in the 3D geometry to better understand the tilt-shift lens.

  1. Historical dynamics in ecosystem service bundles.

    Science.gov (United States)

    Renard, Delphine; Rhemtulla, Jeanine M; Bennett, Elena M

    2015-10-27

    Managing multiple ecosystem services (ES), including addressing trade-offs between services and preventing ecological surprises, is among the most pressing areas for sustainability research. These challenges require ES research to go beyond the currently common approach of snapshot studies limited to one or two services at a single point in time. We used a spatiotemporal approach to examine changes in nine ES and their relationships from 1971 to 2006 across 131 municipalities in a mixed-use landscape in Quebec, Canada. We show how an approach that incorporates time and space can improve our understanding of ES dynamics. We found an increase in the provision of most services through time; however, provision of ES was not uniformly enhanced at all locations. Instead, each municipality specialized in providing a bundle (set of positively correlated ES) dominated by just a few services. The trajectory of bundle formation was related to changes in agricultural policy and global trends; local biophysical and socioeconomic characteristics explained the bundles' increasing spatial clustering. Relationships between services varied through time, with some provisioning and cultural services shifting from a trade-off or no relationship in 1971 to an apparent synergistic relationship by 2006. By implementing a spatiotemporal perspective on multiple services, we provide clear evidence of the dynamic nature of ES interactions and contribute to identifying processes and drivers behind these changing relationships. Our study raises questions about using snapshots of ES provision at a single point in time to build our understanding of ES relationships in complex and dynamic social-ecological systems.

  2. Hydrodynamic behavior of a bare rod bundle

    International Nuclear Information System (INIS)

    Bartzis, J.G.; Todreas, N.E.

    1977-06-01

    The temperature distribution within the rod bundle of a nuclear reactor is of major importance in nuclear reactor design. However temperature information presupposes knowledge of the hydrodynamic behavior of the coolant which is the most difficult part of the problem due to complexity of the turbulence phenomena. In the present work a 2-equation turbulence model--a strong candidate for analyzing actual three dimensional turbulent flows--has been used to predict fully developed flow of infinite bare rod bundle of various aspect ratios (P/D). The model has been modified to take into account anisotropic effects of eddy viscosity. Secondary flow calculations have been also performed although the model seems to be too rough to predict the secondary flow correctly. Heat transfer calculations have been performed to confirm the importance of anisotropic viscosity in temperature predictions. All numerical calculations for flow and heat have been performed by two computer codes based on the TEACH code. Experimental measurements of the distribution of axial velocity, turbulent axial velocity, turbulent kinetic energy and radial Reynolds stresses were performed in the developing and fully developed regions. A 2-channel Laser Doppler Anemometer working on the Reference mode with forward scattering was used to perform the measurements in a simulated interior subchannel of a triangular rod array with P/D = 1.124. Comparisons between the analytical results and the results of this experiment as well as other experimental data in rod bundle array available in literature are presented. The predictions are in good agreement with the results for the high Reynolds numbers

  3. Global properties of systems quantized via bundles

    International Nuclear Information System (INIS)

    Doebner, H.D.; Werth, J.E.

    1978-03-01

    Take a smooth manifold M and a Lie algebra action (g-ation) theta on M as the geometrical arena of a physical system moving on M with momenta given by theta. It is proposed to quantize the system with a Mackey-like method via the associated vector bundle xisub(rho) of a principal bundle xi=(P,π,M,H) with model dependent structure group H and with g-action phi on P lifted from theta on M. This (quantization) bundle xisub(rho) gives the Hilbert space equal to L 2 (xisub(rho),ω) of the system as the linear space of sections in xisub(rho) being square integrable with respect to a volume form ω on M; the usual position operators are obtained; phi leads to a vector field representation D(phisub(rho),theta) of g in an hence Hilbert space to momentum operators. So Hilbert space carries the quantum kinematics. In this quantuzation the physically important connection between geometrical properties of the system, e.g. quasi-completeness of theta and G-maximality of phisub(rho), and global properties of its quantized kinematics, e.g. skew-adjointness of the momenta and integrability of D(phisub(rho), theta) can easily be studied. The relation to Nelson's construction of a skew-adjoint non-integrable Lie algebra representation and to Palais' local G-action is discussed. Finally the results are applied to actions induced by coverings as examples of non-maximal phisub(rho) on Esub(rho) lifted from maximal theta on M which lead to direct consequences for the corresponding quantum kinematics

  4. Modular Bundle Adjustment for Photogrammetric Computations

    Science.gov (United States)

    Börlin, N.; Murtiyoso, A.; Grussenmeyer, P.; Menna, F.; Nocerino, E.

    2018-05-01

    In this paper we investigate how the residuals in bundle adjustment can be split into a composition of simple functions. According to the chain rule, the Jacobian (linearisation) of the residual can be formed as a product of the Jacobians of the individual steps. When implemented, this enables a modularisation of the computation of the bundle adjustment residuals and Jacobians where each component has limited responsibility. This enables simple replacement of components to e.g. implement different projection or rotation models by exchanging a module. The technique has previously been used to implement bundle adjustment in the open-source package DBAT (Börlin and Grussenmeyer, 2013) based on the Photogrammetric and Computer Vision interpretations of Brown (1971) lens distortion model. In this paper, we applied the technique to investigate how affine distortions can be used to model the projection of a tilt-shift lens. Two extended distortion models were implemented to test the hypothesis that the ordering of the affine and lens distortion steps can be changed to reduce the size of the residuals of a tilt-shift lens calibration. Results on synthetic data confirm that the ordering of the affine and lens distortion steps matter and is detectable by DBAT. However, when applied to a real camera calibration data set of a tilt-shift lens, no difference between the extended models was seen. This suggests that the tested hypothesis is false and that other effects need to be modelled to better explain the projection. The relatively low implementation effort that was needed to generate the models suggest that the technique can be used to investigate other novel projection models in photogrammetry, including modelling changes in the 3D geometry to better understand the tilt-shift lens.

  5. A Hodge dual for soldered bundles

    International Nuclear Information System (INIS)

    Lucas, Tiago Gribl; Pereira, J G

    2009-01-01

    In order to account for all possible contractions allowed by the presence of the solder form, a generalized Hodge dual is defined for the case of soldered bundles. Although for curvature the generalized dual coincides with the usual one, for torsion it gives a completely new dual definition. Starting from the standard form of a gauge Lagrangian for the translation group, the generalized Hodge dual yields precisely the Lagrangian of the teleparallel equivalent of general relativity, and consequently also the Einstein-Hilbert Lagrangian of general relativity

  6. Bundling Products and Services Through Modularization Strategies

    DEFF Research Database (Denmark)

    Bask, Anu; Hsuan, Juliana; Rajahonka, Mervi

    2012-01-01

    Modularity has been recognized as a powerful tool in improving the efficiency and management of product design and manufacturing. However, the integrated view on covering both, product and service modularity for product-service systems (PSS), is under researched. Therefore, in this paper our...... objective is to contribute to the PSS modularity. Thus, we describe configurations of PSSs and the bundling of products and services through modularization strategies. So far there have not been tools to analyze and determine the correct combinations of degrees of product and service modularities....

  7. Vector bundles on complex projective spaces

    CERN Document Server

    Okonek, Christian; Spindler, Heinz

    1980-01-01

    This expository treatment is based on a survey given by one of the authors at the Séminaire Bourbaki in November 1978 and on a subsequent course held at the University of Göttingen. It is intended to serve as an introduction to the topical question of classification of holomorphic vector bundles on complex projective spaces, and can easily be read by students with a basic knowledge of analytic or algebraic geometry. Short supplementary sections describe more advanced topics, further results, and unsolved problems.

  8. Differential geometry bundles, connections, metrics and curvature

    CERN Document Server

    Taubes, Clifford Henry

    2011-01-01

    Bundles, connections, metrics and curvature are the 'lingua franca' of modern differential geometry and theoretical physics. This book will supply a graduate student in mathematics or theoretical physics with the fundamentals of these objects. Many of the tools used in differential topology are introduced and the basic results about differentiable manifolds, smooth maps, differential forms, vector fields, Lie groups, and Grassmanians are all presented here. Other material covered includes the basic theorems about geodesics and Jacobi fields, the classification theorem for flat connections, the

  9. Assembly mechanism for nuclear fuel bundles

    International Nuclear Information System (INIS)

    Long, J.W.; Flora, B.S.; Ford, K.L.

    1980-01-01

    The invention relates to a nuclear power reactor fuel bundle of the type wherein several rods are mounted in parallel array between two tie plates which secure the fuel rods in place and are maintained in assembled position by means of a number of tie rods secured to both of the end plates. Improved apparatus is provided for attaching the tie rods to the upper tie plate by the use of locking lugs fixed to rotatable sleeves which engage the upper tie plate. (auth)

  10. Deformation quantization with separation of variables of an endomorphism bundle

    Science.gov (United States)

    Karabegov, Alexander

    2014-01-01

    Given a holomorphic Hermitian vector bundle E and a star-product with separation of variables on a pseudo-Kähler manifold, we construct a star product on the sections of the endomorphism bundle of the dual bundle E∗ which also has the appropriately generalized property of separation of variables. For this star product we prove a generalization of Gammelgaard's graph-theoretic formula.

  11. Relativistic rotators: a quantum mechanical de Sitter bundle

    International Nuclear Information System (INIS)

    Boehm, A.

    1976-02-01

    If de Sitter fiber bundle over space time is the classical picture of hadrons then for a quantum mechanical description one has to generalize the concept of a principal fiber bundle to a bundle that contains the representation of the group of motion. This idea is related to the relativistic rotator model, and the radius of the de Sitter fiber is determined from the experimental hadron spectrum

  12. Crossed Module Bundle Gerbes; Classification, String Group and Differential Geometry

    OpenAIRE

    Jurco, Branislav

    2005-01-01

    We discuss nonabelian bundle gerbes and their differential geometry using simplicial methods. Associated to any crossed module there is a simplicial group NC, the nerve of the 1-category defined by the crossed module and its geometric realization |NC|. Equivalence classes of principal bundles with structure group |NC| are shown to be one-to-one with stable equivalence classes of what we call crossed module gerbes bundle gerbes. We can also associate to a crossed module a 2-category C'. Then t...

  13. Analytic convergence of harmonic metrics for parabolic Higgs bundles

    Science.gov (United States)

    Kim, Semin; Wilkin, Graeme

    2018-04-01

    In this paper we investigate the moduli space of parabolic Higgs bundles over a punctured Riemann surface with varying weights at the punctures. We show that the harmonic metric depends analytically on the weights and the stable Higgs bundle. This gives a Higgs bundle generalisation of a theorem of McOwen on the existence of hyperbolic cone metrics on a punctured surface within a given conformal class, and a generalisation of a theorem of Judge on the analytic parametrisation of these metrics.

  14. Early Results of Anatomic Double Bundle Anterior Cruciate Ligament Reconstruction

    OpenAIRE

    Demet Pepele

    2014-01-01

    Aim: The goal in anterior cruciate ligament reconstruction (ACLR) is to restore the normal anatomic structure and function of the knee. In the significant proportion of patients after the traditional single-bundle ACLR, complaints of instability still continue. Anatomic double bundle ACLR may provide normal kinematics in knees, much closer to the natural anatomy. The aim of this study is to clinically assess the early outcomes of our anatomical double bundle ACLR. Material and Method: In our ...

  15. Heat Transfer Analysis in Wire Bundles for Aerospace Vehicles

    Science.gov (United States)

    Rickman, S. L.; Iamello, C. J.

    2016-01-01

    Design of wiring for aerospace vehicles relies on an understanding of "ampacity" which refers to the current carrying capacity of wires, either, individually or in wire bundles. Designers rely on standards to derate allowable current flow to prevent exceedance of wire temperature limits due to resistive heat dissipation within the wires or wire bundles. These standards often add considerable margin and are based on empirical data. Commercial providers are taking an aggressive approach to wire sizing which challenges the conventional wisdom of the established standards. Thermal modelling of wire bundles may offer significant mass reduction in a system if the technique can be generalized to produce reliable temperature predictions for arbitrary bundle configurations. Thermal analysis has been applied to the problem of wire bundles wherein any or all of the wires within the bundle may carry current. Wire bundles present analytical challenges because the heat transfer path from conductors internal to the bundle is tortuous, relying on internal radiation and thermal interface conductance to move the heat from within the bundle to the external jacket where it can be carried away by convective and radiative heat transfer. The problem is further complicated by the dependence of wire electrical resistivity on temperature. Reduced heat transfer out of the bundle leads to higher conductor temperatures and, hence, increased resistive heat dissipation. Development of a generalized wire bundle thermal model is presented and compared with test data. The steady state heat balance for a single wire is derived and extended to the bundle configuration. The generalized model includes the effects of temperature varying resistance, internal radiation and thermal interface conductance, external radiation and temperature varying convective relief from the free surface. The sensitivity of the response to uncertainties in key model parameters is explored using Monte Carlo analysis.

  16. Local load-sharing fiber bundle model in higher dimensions.

    Science.gov (United States)

    Sinha, Santanu; Kjellstadli, Jonas T; Hansen, Alex

    2015-08-01

    We consider the local load-sharing fiber bundle model in one to five dimensions. Depending on the breaking threshold distribution of the fibers, there is a transition where the fracture process becomes localized. In the localized phase, the model behaves as the invasion percolation model. The difference between the local load-sharing fiber bundle model and the equal load-sharing fiber bundle model vanishes with increasing dimensionality with the characteristics of a power law.

  17. Multiple large filament bundles observed in Caulobacter crescentus by electron cryotomography

    DEFF Research Database (Denmark)

    Briegel, A; Dias, DP; Li, Z

    2006-01-01

    While the absence of any cytoskeleton was once recognized as a distinguishing feature of prokaryotes, it is now clear that a number of different bacterial proteins do form filaments in vivo. Despite the critical roles these proteins play in cell shape, genome segregation and cell division...... on shape and location, referred to here as 'inner curvature', 'cytoplasmic', 'polar' and 'ring-like'. In an attempt to identify at least some of the filaments, we imaged cells where crescentin and MreB filaments would not be present. The inner curvature and cytoplasmic bundles persisted, which together...... with their localization patterns, suggest that they are composed of as-yet unidentified cytoskeletal proteins. Thus bacterial filaments are frequently found as bundles, and their variety and abundance is greater than previously suspected....

  18. Warps, grids and curvature in triple vector bundles

    Science.gov (United States)

    Flari, Magdalini K.; Mackenzie, Kirill

    2018-06-01

    A triple vector bundle is a cube of vector bundle structures which commute in the (strict) categorical sense. A grid in a triple vector bundle is a collection of sections of each bundle structure with certain linearity properties. A grid provides two routes around each face of the triple vector bundle, and six routes from the base manifold to the total manifold; the warps measure the lack of commutativity of these routes. In this paper we first prove that the sum of the warps in a triple vector bundle is zero. The proof we give is intrinsic and, we believe, clearer than the proof using decompositions given earlier by one of us. We apply this result to the triple tangent bundle T^3M of a manifold and deduce (as earlier) the Jacobi identity. We further apply the result to the triple vector bundle T^2A for a vector bundle A using a connection in A to define a grid in T^2A . In this case the curvature emerges from the warp theorem.

  19. Experimental and numerical investigations of BWR fuel bundle inlet flow

    International Nuclear Information System (INIS)

    Hoashi, E; Morooka, S; Ishitori, T; Komita, H; Endo, T; Honda, H; Yamamoto, T; Kato, T; Kawamura, S

    2009-01-01

    We have been studying the mechanism of the flow pattern near the fuel bundle inlet of BWR using both flow visualization test and computational fluid dynamics (CFD) simulation. In the visualization test, both single- and multi-bundle test sections were used. The former test section includes only a corner orifice facing two support beams and the latter simulates 16 bundles surrounded by four beams. An observation window is set on the side of the walls imitating the support beams upstream of the orifices in both test sections. In the CFD simulation, as well as the visualization test, the single-bundle model is composed of one bundle with a corner orifice and the multi-bundle model is a 1/4 cut of the test section that includes 4 bundles with the following four orifices: a corner orifice facing the corner of the two neighboring support beams, a center orifice at the opposite side from the corner orifice, and two side orifices. Twin-vortices were observed just upstream of the corner orifice in the multi-bundle test as well as the single-bundle test. A single-vortex and a vortex filament were observed at the side orifice inlet and no vortex was observed at the center orifice. These flow patterns were also predicted in the CFD simulation using Reynolds Stress Model as a turbulent model and the results were in good agreement with the test results mentioned above. (author)

  20. Enthalpy and void distributions in subchannels of PHWR fuel bundles

    Energy Technology Data Exchange (ETDEWEB)

    Park, J W; Choi, H; Rhee, B W [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1999-12-31

    Two different types of the CANDU fuel bundles have been modeled for the ASSERT-IV code subchannel analysis. From calculated values of mixture enthalpy and void fraction distribution in the fuel bundles, it is found that net buoyancy effect is pronounced in the central region of the DUPIC fuel bundle when compared with the standard CANDU fuel bundle. It is also found that the central region of the DUPIC fuel bundle can be cooled more efficiently than that of the standard fuel bundle. From the calculated mixture enthalpy distribution at the exit of the fuel channel, it is found that the mixture enthalpy and void fraction can be highest in the peripheral region of the DUPIC fuel bundle. On the other hand, the enthalpy and the void fraction were found to be highest in the central region of the standard CANDU fuel bundle at the exit of the fuel channel. This study shows that the subchannel analysis is very useful in assessing thermal behavior of the fuel bundle that could be used in CANDU reactors. 10 refs., 4 figs., 2 tabs. (Author)

  1. Enthalpy and void distributions in subchannels of PHWR fuel bundles

    Energy Technology Data Exchange (ETDEWEB)

    Park, J. W.; Choi, H.; Rhee, B. W. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    Two different types of the CANDU fuel bundles have been modeled for the ASSERT-IV code subchannel analysis. From calculated values of mixture enthalpy and void fraction distribution in the fuel bundles, it is found that net buoyancy effect is pronounced in the central region of the DUPIC fuel bundle when compared with the standard CANDU fuel bundle. It is also found that the central region of the DUPIC fuel bundle can be cooled more efficiently than that of the standard fuel bundle. From the calculated mixture enthalpy distribution at the exit of the fuel channel, it is found that the mixture enthalpy and void fraction can be highest in the peripheral region of the DUPIC fuel bundle. On the other hand, the enthalpy and the void fraction were found to be highest in the central region of the standard CANDU fuel bundle at the exit of the fuel channel. This study shows that the subchannel analysis is very useful in assessing thermal behavior of the fuel bundle that could be used in CANDU reactors. 10 refs., 4 figs., 2 tabs. (Author)

  2. Annular burnout data from rod-bundle experiments

    International Nuclear Information System (INIS)

    Yoder, G.L.; Morris, D.G.; Mullins, C.B.

    1983-01-01

    Burnout data for annular flow in a rod bundle are presented for both transient and steady-state conditions. Tests were performed at the Oak Ridge National Laboratory in the Thermal Hydraulic Test Facility (THTF), a pressurized-water loop containing an electrically heated 64-rod bundle. The bundle configuration is typical of later generation pressurized-water reactors with 17 x 17 fuel arrays. Both axial and radial power profiles are flat. All experiments were carried out in upflow with subcooled inlet conditions, insuring accurate flow measurement. Conditions within the bundle were typical of those which could be encountered during a nuclear reactor loss-of-coolant accident

  3. The differential geometry of higher order jets and tangent bundles

    International Nuclear Information System (INIS)

    De Leon, M.; Rodrigues, P.R.

    1985-01-01

    This chapter is devoted to the study of basic geometrical notions required for the development of the main object of the text. Some facts about Jet theory are reviewed. A particular case of Jet manifolds is considered: the tangent bundle of higher order. It is shown that this jet bundle possesses in a canonical way a certain kind of geometric structure, the so called almost tangent structure of higher order, and which is a generalization of the almost tangent geometry of the tangent bundle. Another important fact examined is the extension of the notion of 'spray' to higher order tangent bundles. (Auth.)

  4. Restriction Theorem for Principal bundles in Arbitrary Characteristic

    DEFF Research Database (Denmark)

    Gurjar, Sudarshan

    2015-01-01

    The aim of this paper is to prove two basic restriction theorem for principal bundles on smooth projective varieties in arbitrary characteristic generalizing the analogues theorems of Mehta-Ramanathan for vector bundles. More precisely, let G be a reductive algebraic group over an algebraically...... closed field k and let X be a smooth, projective variety over k together with a very ample line bundle O(1). The main result of the paper is that if E is a semistable (resp. stable) principal G-bundle on X w.r.t O(1), then the restriction of E to a general, high multi-degree, complete-intersection curve...

  5. Molybdenum-99-producing 37-element fuel bundle neutronically and thermal-hydraulically equivalent to a standard CANDU fuel bundle

    Energy Technology Data Exchange (ETDEWEB)

    Nichita, E., E-mail: Eleodor.Nichita@uoit.ca; Haroon, J., E-mail: Jawad.Haroon@uoit.ca

    2016-10-15

    Highlights: • A 37-element fuel bundle modified for {sup 99}Mo production in CANDU reactors is presented. • The modified bundle is neutronically and thermal-hydraulically equivalent to the standard bundle. • The modified bundle satisfies all safety criteria satisfied by the standard bundle. - Abstract: {sup 99m}Tc, the most commonly used radioisotope in diagnostic nuclear medicine, results from the radioactive decay of {sup 99}Mo which is currently being produced at various research reactors around the globe. In this study, the potential use of CANDU power reactors for the production of {sup 99}Mo is investigated. A modified 37-element fuel bundle, suitable for the production of {sup 99}Mo in existing CANDU-type reactors is proposed. The new bundle is specifically designed to be neutronically and thermal-hydraulically equivalent to the standard 37-element CANDU fuel bundle in normal, steady-state operation and, at the same time, be able to produce significant quantities of {sup 99}Mo when irradiated in a CANDU reactor. The proposed bundle design uses fuel pins consisting of a depleted-uranium centre surrounded by a thin layer of low-enriched uranium. The new molybdenum-producing bundle is analyzed using the lattice transport code DRAGON and the diffusion code DONJON. The proposed design is shown to produce 4081 six-day Curies of {sup 99}Mo activity per bundle when irradiated in the peak-power channel of a CANDU core, while maintaining the necessary reactivity and power rating limits. The calculated {sup 99}Mo yield corresponds to approximately one third of the world weekly demand. A production rate of ∼3 bundles per week can meet the global demand of {sup 99}Mo.

  6. David et al (12)

    African Journals Online (AJOL)

    DELL

    larger mesophyll cells, xylem tissues, vascular bundles and bundle sheaths than other cultivars. Thus, larger ... mechanism to cope with drought stress. There was an ... where solar radiation is intense (Løe et al., 2007). Most ecological studies ...

  7. Confinement-Dependent Friction in Peptide Bundles

    Science.gov (United States)

    Erbaş, Aykut; Netz, Roland R.

    2013-01-01

    Friction within globular proteins or between adhering macromolecules crucially determines the kinetics of protein folding, the formation, and the relaxation of self-assembled molecular systems. One fundamental question is how these friction effects depend on the local environment and in particular on the presence of water. In this model study, we use fully atomistic MD simulations with explicit water to obtain friction forces as a single polyglycine peptide chain is pulled out of a bundle of k adhering parallel polyglycine peptide chains. The whole system is periodically replicated along the peptide axes, so a stationary state at prescribed mean sliding velocity V is achieved. The aggregation number is varied between k = 2 (two peptide chains adhering to each other with plenty of water present at the adhesion sites) and k = 7 (one peptide chain pulled out from a close-packed cylindrical array of six neighboring peptide chains with no water inside the bundle). The friction coefficient per hydrogen bond, extrapolated to the viscous limit of vanishing pulling velocity V → 0, exhibits an increase by five orders of magnitude when going from k = 2 to k = 7. This dramatic confinement-induced friction enhancement we argue to be due to a combination of water depletion and increased hydrogen-bond cooperativity. PMID:23528088

  8. Reversibility and Viscoelastic Properties of Micropillar Supported and Oriented Magnesium Bundled F-Actin.

    Directory of Open Access Journals (Sweden)

    Timo Maier

    Full Text Available Filamentous actin is one of the most important cytoskeletal elements. Not only is it responsible for the elastic properties of many cell types, but it also plays a vital role in cellular adhesion and motility. Understanding the bundling kinetics of actin filaments is important in the formation of various cytoskeletal structures, such as filopodia and stress fibers. Utilizing a unique pillar-structured microfluidic device, we investigated the time dependence of bundling kinetics of pillar supported free-standing actin filaments. Microparticles attached to the filaments allowed the measurement of thermal motion, and we found that bundling takes place at lower concentrations than previously found in 3-dimensional actin gels, i.e. actin filaments formed bundles in the presence of 5-12 mM of magnesium chloride in a time-dependent manner. The filaments also displayed long term stability for up to hours after removing the magnesium ions from the buffer, which suggests that there is an extensive hysteresis between cation induced crosslinking and decrosslinking.

  9. Safety assessment for the CANFLEX-NU fuel bundles with respect to the 37-element fuel bundles

    Energy Technology Data Exchange (ETDEWEB)

    Suk, H. C.; Lim, H. S. [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-11-01

    The KAERI and AECL have jointly developed an advanced CANDU fuel, called CANFLEX-NU fuel bundle. CANFLEX 43-element bundle has some improved features of increased operating margin and enhanced safety compared to the existing 37-element bundle. Since CANFLEX fuel bundle is designed to be compatible with the CANDU-6 reactor design, the behaviour in the thermalhydraulic system will be nearly identical with 37-element bundle. But due to different element design and linear element power distribution between the two bundles, it is expected that CANFLEX fuel behaviour would be different from the behaviour of the 37-element fuel. Therefore, safety assessments on the design basis accidents which result if fuel failures are performed. For all accidents selected, it is observed that the loading of CANFLEX bundle in an existing CANDU-6 reactor would not worsen the reactor safety. It is also predicted that fission product release for CANFLEX fuel bundle generally is lower than that for 37-element bundle. 3 refs., 2 figs., 2 tabs. (Author)

  10. Real-time wavelet-based inline banknote-in-bundle counting for cut-and-bundle machines

    Science.gov (United States)

    Petker, Denis; Lohweg, Volker; Gillich, Eugen; Türke, Thomas; Willeke, Harald; Lochmüller, Jens; Schaede, Johannes

    2011-03-01

    Automatic banknote sheet cut-and-bundle machines are widely used within the scope of banknote production. Beside the cutting-and-bundling, which is a mature technology, image-processing-based quality inspection for this type of machine is attractive. We present in this work a new real-time Touchless Counting and perspective cutting blade quality insurance system, based on a Color-CCD-Camera and a dual-core Computer, for cut-and-bundle applications in banknote production. The system, which applies Wavelet-based multi-scale filtering is able to count banknotes inside a 100-bundle within 200-300 ms depending on the window size.

  11. Evaluation of Single-Bundle versus Double-Bundle PCL Reconstructions with More Than 10-Year Follow-Up

    Directory of Open Access Journals (Sweden)

    Masataka Deie

    2015-01-01

    Full Text Available Background. Posterior cruciate ligament (PCL injuries are not rare in acute knee injuries, and several recent anatomical studies of the PCL and reconstructive surgical techniques have generated improved patient results. Now, we have evaluated PCL reconstructions performed by either the single-bundle or double-bundle technique in a patient group followed up retrospectively for more than 10 years. Methods. PCL reconstructions were conducted using the single-bundle (27 cases or double-bundle (13 cases method from 1999 to 2002. The mean age at surgery was 34 years in the single-bundle group and 32 years in the double-bundle group. The mean follow-up period was 12.5 years. Patients were evaluated by Lysholm scoring, the gravity sag view, and knee arthrometry. Results. The Lysholm score after surgery was 89.1±5.6 points for the single-bundle group and 91.9±4.5 points for the double-bundle group. There was no significant difference between the methods in the side-to-side differences by gravity sag view or knee arthrometer evaluation, although several cases in both groups showed a side-to-side difference exceeding 5 mm by the latter evaluation method. Conclusions. We found no significant difference between single- and double-bundle PCL reconstructions during more than 10 years of follow-up.

  12. Design of Cold-Formed Steel Screw Connections with Gypsum Sheathing at Ambient and Elevated Temperatures

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2016-09-01

    Full Text Available Load-bearing cold-formed steel (CFS walls sheathed with double layers of gypsum plasterboard on both sides have demonstrated good fire resistance and attracted increasing interest for use in mid-rise CFS structures. As the main connection method, screw connections between CFS and gypsum sheathing play an important role in both the structural design and fire resistance of this wall system. However, studies on the mechanical behavior of screw connections with double-layer gypsum sheathing are still limited. In this study, 200 monotonic tests of screw connections with single- or double-layer gypsum sheathing at both ambient and elevated temperatures were conducted. The failure of screw connections with double-layer gypsum sheathing in shear was different from that of single-layer gypsum sheathing connections at ambient temperature, and it could be described as the breaking of the loaded sheathing edge combined with significant screw tilting and the loaded sheathing edge flexing fracture. However, the screw tilting and flexing fracture of the loaded sheathing edge gradually disappear at elevated temperatures. In addition, the influence of the loaded edge distance, double-layer sheathing and elevated temperatures is discussed in detail with clear conclusions. A unified design formula for the shear strength of screw connections with gypsum sheathing is proposed for ambient and elevated temperatures with adequate accuracy. A simplified load–displacement model with the post-peak branch is developed to evaluate the load–displacement response of screw connections with gypsum sheathing at ambient and elevated temperatures.

  13. Stimulation of hair cells with ultraviolet light

    Science.gov (United States)

    Azimzadeh, Julien B.; Fabella, Brian A.; Hudspeth, A. J.

    2018-05-01

    Hair bundles are specialized organelles that transduce mechanical inputs into electrical outputs. To activate hair cells, physiologists have resorted to mechanical methods of hair-bundle stimulation. Here we describe a new method of hair-bundle stimulation, irradiation with ultraviolet light. A hair bundle illuminated by ultraviolet light rapidly moves towards its tall edge, a motion typically associated with excitatory stimulation. The motion disappears upon tip-link rupture and is associated with the opening of mechanotransduction channels. Hair bundles can be induced to move sinusoidally with oscillatory modulation of the stimulation power. We discuss the implications of ultraviolet stimulation as a novel hair-bundle stimulus.

  14. Infrared Imaging of Cotton Fiber Bundles Using a Focal Plane Array Detector and a Single Reflectance Accessory

    Directory of Open Access Journals (Sweden)

    Michael Santiago Cintrón

    2016-11-01

    Full Text Available Infrared imaging is gaining attention as a technique used in the examination of cotton fibers. This type of imaging combines spectral analysis with spatial resolution to create visual images that examine sample composition and distribution. Herein, we report on the use of an infrared instrument equipped with a reflection accessory and an array detector system for the examination of cotton fiber bundles. Cotton vibrational spectra and chemical images were acquired by grouping pixels in the detector array. This technique reduced spectral noise and was employed to visualize cell wall development in cotton fibers bundles. Fourier transform infrared spectra reveal band changes in the C–O bending region that matched previous studies. Imaging studies were quick, relied on small amounts of sample and provided a distribution of the cotton fiber cell wall composition. Thus, imaging of cotton bundles with an infrared detector array has potential for use in cotton fiber examinations.

  15. Properties of plasma sheath with ion temperature in magnetic fusion devices

    International Nuclear Information System (INIS)

    Liu Jinyuan; Wang Feng; Sun Jizhong

    2011-01-01

    The plasma sheath properties in a strong magnetic field are investigated in this work using a steady state two-fluid model. The motion of ions is affected heavily by the strong magnetic field in fusion devices; meanwhile, the effect of ion temperature cannot be neglected for the plasma in such devices. A criterion for the plasma sheath in a strong magnetic field, which differs from the well-known Bohm criterion for low temperature plasma sheath, is established theoretically with a fluid model. The fluid model is then solved numerically to obtain detailed sheath information under different ion temperatures, plasma densities, and magnetic field strengths.

  16. Electric sheath and presheath in a collisionless, finite ion temperature plasma

    International Nuclear Information System (INIS)

    Emmert, G.A.; Wieland, R.M.; Mense, A.T.; Davidson, J.N.

    1980-01-01

    The plasma-sheath equation for a collisionless plasma with arbitrary ion temperature in plane geometry is formulated. Outside the sheath, this equation is approximated by the plasma equation, for which an analytic solution for the electrostatic potential is obtained. In addition, the ion distribution function, the wall potential, and the ion energy and particle flux into the sheath are explicitly calculated. The plasma-sheath equation is also solved numerically with no approximation of the Debye length. The numerical results compare well with the analytical results when the Debye length is small

  17. The dust motion inside the magnetized sheath - The effect of drag forces

    International Nuclear Information System (INIS)

    Pandey, B. P.; Samarian, A.; Vladimirov, S. V.

    2010-01-01

    The isolated charged dust inside the magnetized plasma sheath moves under the influence of the electron and ion drag force and the sheath electrostatic field. The charge on the dust is a function of its radius as well as the value of the ambient sheath potential. It is shown that the charge on the dust determines its trajectory and dust performs the spiraling motion inside the sheath. The location of the turning spiral is determined by the number of negative charge on the dust, which in turn is a function of the dust radius. The back and forth spiraling motion finally causes the dust to move in a small, narrow region of the sheath. For a bigger dust particle, the dust moves closer to the sheath presheath boundary suggesting that the bigger grains, owing to the strong repulsion between the wall and dust, will be unable to travel inside the sheath. Only small, micron-sized grains can travel closer to the wall before repulsion pushes it back toward the plasma-sheath boundary. The temporal behavior of the spiraling dust motion appears like a damped harmonic oscillation, suggesting that the plasma drag force causes dissipation of the electrostatic energy. However, after initial damping, the grain keeps oscillating although with much smaller amplitude. The possible application of the present results to the ongoing sheath experiments is discussed.

  18. Slow Wave Propagation and Sheath Interaction for ICRF Waves in the Tokamak SOL

    International Nuclear Information System (INIS)

    Myra, J. R.; D'Ippolito, D. A.

    2009-01-01

    In previous work we studied the propagation of slow-wave resonance cones launched parasitically by a fast-wave antenna into a tenuous magnetized plasma. Here we extend the previous calculation to ''dense'' scrape-off-layer (SOL) plasmas where the usual slow wave is evanescent. Using the sheath boundary condition, it is shown that for sufficiently close limiters, the slow wave couples to a sheath plasma wave and is no longer evanescent, but radially propagating. A self-consistent calculation of the rf-sheath width yields the resulting sheath voltage in terms of the amplitude of the launched SW, plasma parameters and connection length.

  19. Role of CD44 in Malignant Peripheral Nerve Sheath Tumor Growth and Metastasis

    National Research Council Canada - National Science Library

    Sherman, Larry

    2003-01-01

    Malignant peripheral nerve sheath tumors (MPNST) are aggressive, difficult to treat tumors that occur in type I neurofibromatosis patients with an increased incidence compared to the general population...

  20. Role of CD44 in Malignant Peripheral Nerve Sheath Tumor Growth and Metastasis

    National Research Council Canada - National Science Library

    Sherman, Larry

    2001-01-01

    Malignant peripheral nerve sheath tumors (MPNST) are aggressive, difficult to treat tumors that occur in type I neurofibromatosis patients with an increased incidence compared to the general population...

  1. Community structure of filamentous, sheath-building sulfur bacteria, Thioploca spp, off the coast of Chile

    DEFF Research Database (Denmark)

    Schulz, HN; Jørgensen, BB; Fossing, HA

    1996-01-01

    of Concepcion was investigated,vith respect to biomass, species distribution, and three-dimensional orientation of the sheaths, Thioploca sheaths and filaments were found across the whole shelf area within the oxygen minimum zone, The maximum wet weight of sheaths, 800 g m(-2), was found at a depth of 90 m......The filamentous sulfur bacteria Thioploca spp, produce dense bacterial mats in the shelf area off the coast of Chile and Peru. The mat consists of common sheaths, shared by many filaments, that reach 5 to 10 cm dean into the sediment, The structure of the Thioploca communities off the Bay...

  2. Miscellaneous conditions of tendons, tendon sheaths, and ligaments.

    Science.gov (United States)

    Dyson, S J; Dik, K J

    1995-08-01

    The use of diagnostic ultrasonography has greatly enhances our ability to diagnose injuries of tendons and tendon sheaths that were previously either unrecognized or poorly understood. For may of these injuries, there is currently only a small amount of follow-up data. This article considers injuries of the deep digital flexor tendon and its accessory ligament, the carpal tunnel syndrome soft tissue swellings on the dorsal aspect of the carpus, intertubercular (bicipital) bursitis and bicipital tendinitis, injuries of the gastrocnemius tendon, common calcaneal tendinitis, rupture of peroneus (fibularis tertius) and ligaments injuries of the back.

  3. The new concept of ureteral access sheath with guidewire disengagement

    DEFF Research Database (Denmark)

    Breda, Alberto; Emiliani, Esteban; Millán, Felix

    2016-01-01

    PURPOSE: To prospectively evaluate the new Flexor©Parallel™ Rapid Release™ (Cook(®), Bloomington, IN, USA) access sheath (UAS) which allows the use of a single wire to serve as both safety and working guide. MATERIALS AND METHODS: Between June and September 2014, adult patients from five European...... by the surgeons on a scale from very bad to very good. RESULTS: In total, 134 UASs were used in 67 male and 67 female patients. Fifty percent of ureters (67 patients) were pre-stented. Ninety percent of the procedures were therapeutic. The overall successful insertion rate was 94 %. Pre-stenting status...

  4. Repairing a steam generator tube by inserting a sheath

    International Nuclear Information System (INIS)

    Gaudin, J.P.

    1986-01-01

    According to the invention, the mechanical deformation of the sheath, realized by expansion in its end part opposite to the expanded end within the tube plate, is situated along a limited height, and the parameters of the said mechanical deformation are calculated according to the welding parameters applied consecutively. Besides, the said welding parameters are determined according to the initial mechanical deformation to obtain stress relaxation more particularly in the singular zones of the mechanical deformation. The present invention applies to the repair of PWR steam generator tubes [fr

  5. The WUW ML bundle detector A flow through detector for alpha-emitters

    CERN Document Server

    Wenzel, U; Lochny, M

    1999-01-01

    Using conventional laboratory ware, we designed and manufactured a flow through cell for monitoring alpha-bearing solutions. The cell consists of a bundle of thermoplastic, transparent tubes coated with a thin layer of the meltable scintillator MELTILEX sup T sup M at the inner surface. With appropriate energy windows set, the detector can suppress beta-particles to a great extent due to its geometrical dimensions. For pure alpha-solutions, the detection limits are 5 Bq/ml, for composite nuclide mixtures, the detector is capable to monitor the decontamination of medium active waste (<=10 sup 7 Bq/ml) down to 100 Bq alpha/g solution. At a throughput of 1 ml/s, the pressure build-up amounts to approx 2 bar. We have developed a quality control program to ensure the regularity of the individual bundle loops.

  6. Moduli of Parabolic Higgs Bundles and Atiyah Algebroids

    DEFF Research Database (Denmark)

    Logares, Marina; Martens, Johan

    2010-01-01

    In this paper we study the geometry of the moduli space of (non-strongly) parabolic Higgs bundles over a Riemann surface with marked points. We show that this space possesses a Poisson structure, extending the one on the dual of an Atiyah algebroid over the moduli space of parabolic vector bundle...

  7. Infinite Grassmannian and moduli space of G-bundles

    International Nuclear Information System (INIS)

    Kumar, S.; Ramanathan, A.

    1993-03-01

    Let C be a smooth irreducible projective curve and G a simply connected simple affine algebraic group of C. We study in this paper the relationship between the space of vacua defined in Conformal Field Theory and the space of sections of a line bundle on the moduli space of G-bundles over C. (author). 33 refs

  8. Monoubiquitination Inhibits the Actin Bundling Activity of Fascin.

    Science.gov (United States)

    Lin, Shengchen; Lu, Shuang; Mulaj, Mentor; Fang, Bin; Keeley, Tyler; Wan, Lixin; Hao, Jihui; Muschol, Martin; Sun, Jianwei; Yang, Shengyu

    2016-12-30

    Fascin is an actin bundling protein that cross-links individual actin filaments into straight, compact, and stiff bundles, which are crucial for the formation of filopodia, stereocillia, and other finger-like membrane protrusions. The dysregulation of fascin has been implicated in cancer metastasis, hearing loss, and blindness. Here we identified monoubiquitination as a novel mechanism that regulates fascin bundling activity and dynamics. The monoubiquitination sites were identified to be Lys 247 and Lys 250 , two residues located in a positive charge patch at the actin binding site 2 of fascin. Using a chemical ubiquitination method, we synthesized chemically monoubiquitinated fascin and determined the effects of monoubiquitination on fascin bundling activity and dynamics. Our data demonstrated that monoubiquitination decreased the fascin bundling EC 50 , delayed the initiation of bundle assembly, and accelerated the disassembly of existing bundles. By analyzing the electrostatic properties on the solvent-accessible surface of fascin, we proposed that monoubiquitination introduced steric hindrance to interfere with the interaction between actin filaments and the positively charged patch at actin binding site 2. We also identified Smurf1 as a E3 ligase regulating the monoubiquitination of fascin. Our findings revealed a previously unidentified regulatory mechanism for fascin, which will have important implications for the understanding of actin bundle regulation under physiological and pathological conditions. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  9. Monoubiquitination Inhibits the Actin Bundling Activity of Fascin*

    Science.gov (United States)

    Lin, Shengchen; Lu, Shuang; Mulaj, Mentor; Fang, Bin; Keeley, Tyler; Wan, Lixin; Hao, Jihui; Muschol, Martin; Sun, Jianwei; Yang, Shengyu

    2016-01-01

    Fascin is an actin bundling protein that cross-links individual actin filaments into straight, compact, and stiff bundles, which are crucial for the formation of filopodia, stereocillia, and other finger-like membrane protrusions. The dysregulation of fascin has been implicated in cancer metastasis, hearing loss, and blindness. Here we identified monoubiquitination as a novel mechanism that regulates fascin bundling activity and dynamics. The monoubiquitination sites were identified to be Lys247 and Lys250, two residues located in a positive charge patch at the actin binding site 2 of fascin. Using a chemical ubiquitination method, we synthesized chemically monoubiquitinated fascin and determined the effects of monoubiquitination on fascin bundling activity and dynamics. Our data demonstrated that monoubiquitination decreased the fascin bundling EC50, delayed the initiation of bundle assembly, and accelerated the disassembly of existing bundles. By analyzing the electrostatic properties on the solvent-accessible surface of fascin, we proposed that monoubiquitination introduced steric hindrance to interfere with the interaction between actin filaments and the positively charged patch at actin binding site 2. We also identified Smurf1 as a E3 ligase regulating the monoubiquitination of fascin. Our findings revealed a previously unidentified regulatory mechanism for fascin, which will have important implications for the understanding of actin bundle regulation under physiological and pathological conditions. PMID:27879315

  10. An overview on rod-bundle thermal-hydraulic analyses

    International Nuclear Information System (INIS)

    Sha, W.T.

    1980-01-01

    Three methods used in rod-bundle thermal-hydraulic analysis are summarized. These methods are: (1) subchannel analysis, (2) porous medium formulation with volume porosity, surface permeability, distributed resistance and distributed heat source (sink) and, (3) bench-mark rod-bundle thermal-hydraulic analysis using a boundary-fitted coordinate system. Basic limitations and merits of each method are delineated. (orig.)

  11. Computational imaging through a fiber-optic bundle

    Science.gov (United States)

    Lodhi, Muhammad A.; Dumas, John Paul; Pierce, Mark C.; Bajwa, Waheed U.

    2017-05-01

    Compressive sensing (CS) has proven to be a viable method for reconstructing high-resolution signals using low-resolution measurements. Integrating CS principles into an optical system allows for higher-resolution imaging using lower-resolution sensor arrays. In contrast to prior works on CS-based imaging, our focus in this paper is on imaging through fiber-optic bundles, in which manufacturing constraints limit individual fiber spacing to around 2 μm. This limitation essentially renders fiber-optic bundles as low-resolution sensors with relatively few resolvable points per unit area. These fiber bundles are often used in minimally invasive medical instruments for viewing tissue at macro and microscopic levels. While the compact nature and flexibility of fiber bundles allow for excellent tissue access in-vivo, imaging through fiber bundles does not provide the fine details of tissue features that is demanded in some medical situations. Our hypothesis is that adapting existing CS principles to fiber bundle-based optical systems will overcome the resolution limitation inherent in fiber-bundle imaging. In a previous paper we examined the practical challenges involved in implementing a highly parallel version of the single-pixel camera while focusing on synthetic objects. This paper extends the same architecture for fiber-bundle imaging under incoherent illumination and addresses some practical issues associated with imaging physical objects. Additionally, we model the optical non-idealities in the system to get lower modelling errors.

  12. The behaviour of Phenix fuel pin bundle under irradiation

    International Nuclear Information System (INIS)

    Marbach, G.; Millet, P.; Blanchard, P.; Huillery, R.

    1979-07-01

    An entire Phenix sub-assembly has been mounted and sectioned after irradiation. The examination of cross-sections revealed the effects of mechanical interaction in the bundle (ovalisations and contacts between clads). According to analysis of the sodium channels, cooling of the pin bundle remained uniform. (author)

  13. Smooth Bundling of Large Streaming and Sequence Graphs

    NARCIS (Netherlands)

    Hurter, C.; Ersoy, O.; Telea, A.

    2013-01-01

    Dynamic graphs are increasingly pervasive in modern information systems. However, understanding how a graph changes in time is difficult. We present here two techniques for simplified visualization of dynamic graphs using edge bundles. The first technique uses a recent image-based graph bundling

  14. Two-categorical bundles and their classifying spaces

    DEFF Research Database (Denmark)

    Baas, Nils A.; Bökstedt, M.; Kro, T.A.

    2012-01-01

    -category is a classifying space for the associated principal 2-bundles. In the process of proving this we develop a lot of powerful machinery which may be useful in further studies of 2-categorical topology. As a corollary we get a new proof of the classification of principal bundles. A calculation based...

  15. Multi-bundle shashlik calorimeter prototypes beam-test results

    International Nuclear Information System (INIS)

    Badier, J.; Bloch, P.; Bityukov, S.; Bordalo, P.; Busson, P.; Charlot, C.; Dobrzynski, L.; Golutvin, I.; Guschin, E.; Issakov, V.; Ivanchenko, I.; Klimenko, V.; Marin, V.; Moissenz, P.; Obraztsov, V.; Ostankov, A.; Popov, V.; Puljak, I.; Ramos, S.; Seez, C.; Sergueev, S.; Soushkov, V.; Tanaka, R.; Varela, J.; Virdee, T.S.; Zaitchenko, A.; Zamiatin, N.

    1995-01-01

    The first beam-test results for two- and three-bundle shashlik tower prototypes are described. We found that the spatial resolution, the uniformity of energy response, the calorimeter reliability and hermeticity and also two showers separation are improved in multi-bundle design approach. ((orig.))

  16. Stability of Picard Bundle Over Moduli Space of Stable Vector ...

    Indian Academy of Sciences (India)

    Abstract. Answering a question of [BV] it is proved that the Picard bundle on the moduli space of stable vector bundles of rank two, on a Riemann surface of genus at least three, with fixed determinant of odd degree is stable.

  17. Tokyo Guidelines 2018: management bundles for acute cholangitis and cholecystitis

    NARCIS (Netherlands)

    Mayumi, Toshihiko; Okamoto, Kohji; Takada, Tadahiro; Strasberg, Steven M.; Solomkin, Joseph S.; Schlossberg, David; Pitt, Henry A.; Yoshida, Masahiro; Gomi, Harumi; Miura, Fumihiko; Garden, O. James; Kiriyama, Seiki; Yokoe, Masamichi; Endo, Itaru; Asbun, Horacio J.; Iwashita, Yukio; Hibi, Taizo; Umezawa, Akiko; Suzuki, Kenji; Itoi, Takao; Hata, Jiro; Han, Ho-Seong; Hwang, Tsann-Long; Dervenis, Christos; Asai, Koji; Mori, Yasuhisa; Huang, Wayne Shih-Wei; Belli, Giulio; Mukai, Shuntaro; Jagannath, Palepu; Cherqui, Daniel; Kozaka, Kazuto; Baron, Todd H.; de Santibañes, Eduardo; Higuchi, Ryota; Wada, Keita; Gouma, Dirk J.; Deziel, Daniel J.; Liau, Kui-Hin; Wakabayashi, Go; Padbury, Robert; Jonas, Eduard; Supe, Avinash Nivritti; Singh, Harjit; Gabata, Toshifumi; Chan, Angus C. W.; Lau, Wan Yee; Fan, Sheung Tat; Chen, Miin-Fu; Ker, Chen-Guo; Yoon, Yoo-Seok; Choi, In-Seok; Kim, Myung-Hwan; Yoon, Dong-Sup; Kitano, Seigo; Inomata, Masafumi; Hirata, Koichi; Inui, Kazuo; Sumiyama, Yoshinobu; Yamamoto, Masakazu

    2018-01-01

    Management bundles that define items or procedures strongly recommended in clinical practice have been used in many guidelines in recent years. Application of these bundles facilitates the adaptation of guidelines and helps improve the prognosis of target diseases. In Tokyo Guidelines 2013 (TG13),

  18. The avalanche process of the multilinear fiber bundles model

    International Nuclear Information System (INIS)

    Hao, Da-Peng; Tang, Gang; Xun, Zhi-Peng; Xia, Hui; Han, Kui

    2012-01-01

    In order to describe the smooth nonlinear constitutive behavior in the process of fracture of ductile micromechanics structures, the multilinear fiber bundle model was constructed, based on the bilinear fiber bundle model. In the multilinear fiber bundle model, the Young modulus of a fiber is assumed to decay K max times before the final failure occurs. For the large K max region, this model can describe the smooth nonlinear constitutive behavior well. By means of analytical approximation and numerical simulation, we show that the two critical parameters, i.e. the decay ratio of the Young modulus and the maximum number of decays, have substantial effects on the failure process of the bundle. From a macroscopic view, the model can provide various shapes of constitutive curves, which represent diverse kinds of tensile fracture processes. However, at the microscopic scale, the statistical properties of the model are in accord with the classical fiber bundle model. (paper)

  19. Introduction to the theory of fiber bundles and connections I

    International Nuclear Information System (INIS)

    Socolvsky, M.

    1990-01-01

    In lectures 1 and 2 we discuss basic concepts of topology and differential geometry: definition of a topological space and of Hausdorff, compact, connected and paracompact spaces; topological groups and actions of groups on spaces; differentiable manifolds, tangent vectors and 1 forms; partitions of unity and Lie groups. In lecture 3 we present the concept of a fiber bundle and discuss vector bundles and principal bundles. The concept of a connection on a smooth vector bundle is defined in lecture 4, together with the associated concepts of curvature and parallel transport; as an illustration we present the Levi-Civita connection on a Riemannian manifold. Finally, in lecture 5 we define connections on principal bundles and present examples with the Lie groups U(1) and SU(2). For reasons of space the present article only includes lectures 1, 2 and 3. Lectures 4 and 5 will be published in a forthcoming paper. (Author)

  20. Bundles over Quantum RealWeighted Projective Spaces

    Directory of Open Access Journals (Sweden)

    Tomasz Brzeziński

    2012-09-01

    Full Text Available The algebraic approach to bundles in non-commutative geometry and the definition of quantum real weighted projective spaces are reviewed. Principal U(1-bundles over quantum real weighted projective spaces are constructed. As the spaces in question fall into two separate classes, the negative or odd class that generalises quantum real projective planes and the positive or even class that generalises the quantum disc, so do the constructed principal bundles. In the negative case the principal bundle is proven to be non-trivial and associated projective modules are described. In the positive case the principal bundles turn out to be trivial, and so all the associated modules are free. It is also shown that the circle (coactions on the quantum Seifert manifold that define quantum real weighted projective spaces are almost free.