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Sample records for rat whisker barrel

  1. A radial map of multi-whisker correlation selectivity in the rat barrel cortex.

    Science.gov (United States)

    Estebanez, Luc; Bertherat, Julien; Shulz, Daniel E; Bourdieu, Laurent; Léger, Jean-François

    2016-11-21

    In the barrel cortex, several features of single-whisker stimuli are organized in functional maps. The barrel cortex also encodes spatio-temporal correlation patterns of multi-whisker inputs, but so far the cortical mapping of neurons tuned to such input statistics is unknown. Here we report that layer 2/3 of the rat barrel cortex contains an additional functional map based on neuronal tuning to correlated versus uncorrelated multi-whisker stimuli: neuron responses to uncorrelated multi-whisker stimulation are strongest above barrel centres, whereas neuron responses to correlated and anti-correlated multi-whisker stimulation peak above the barrel-septal borders, forming rings of multi-whisker synchrony-preferring cells.

  2. Beta 2-adrenergic receptors are colocalized and coregulated with whisker barrels in rat somatosensory cortex

    International Nuclear Information System (INIS)

    Vos, P.; Kaufmann, D.; Hand, P.J.; Wolfe, B.B.

    1990-01-01

    Autoradiography has been used to visualize independently the subtypes of beta-adrenergic receptors in rat somatosensory cortex. Beta 2-adrenergic receptors, but not beta 1-adrenergic receptors colocalize with whisker barrels in this tissue. Thus, each whisker sends a specific multisynaptic pathway to the somatosensory cortex that can be histochemically visualized and only one subtype of beta-adrenergic receptor is specifically associated with this cortical representation. Additionally, neonatal lesion of any or all of the whisker follicles results in loss of the corresponding barrel(s) as shown by histochemical markers. This loss is paralleled by a similar loss in the organization of beta 2-adrenergic receptors in the somatosensory cortex. Other results indicate that these beta 2-adrenergic receptors are not involved in moment-to-moment signal transmission in this pathway and, additionally, are not involved in a gross way in the development of whisker-barrel array

  3. Whiskers aid anemotaxis in rats.

    Science.gov (United States)

    Yu, Yan S W; Graff, Matthew M; Bresee, Chris S; Man, Yan B; Hartmann, Mitra J Z

    2016-08-01

    Observation of terrestrial mammals suggests that they can follow the wind (anemotaxis), but the sensory cues underlying this ability have not been studied. We identify a significant contribution to anemotaxis mediated by whiskers (vibrissae), a modality previously studied only in the context of direct tactile contact. Five rats trained on a five-alternative forced-choice airflow localization task exhibited significant performance decrements after vibrissal removal. In contrast, vibrissal removal did not disrupt the performance of control animals trained to localize a light source. The performance decrement of individual rats was related to their airspeed threshold for successful localization: animals that found the task more challenging relied more on the vibrissae for localization cues. Following vibrissal removal, the rats deviated more from the straight-line path to the air source, choosing sources farther from the correct location. Our results indicate that rats can perform anemotaxis and that whiskers greatly facilitate this ability. Because air currents carry information about both odor content and location, these findings are discussed in terms of the adaptive significance of the interaction between sniffing and whisking in rodents.

  4. Effects of Adaptation on Discrimination of Whisker Deflection Velocity and Angular Direction in a Model of the Barrel Cortex

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    Mainak J. Patel

    2018-06-01

    Full Text Available Two important stimulus features represented within the rodent barrel cortex are velocity and angular direction of whisker deflection. Each cortical barrel receives information from thalamocortical (TC cells that relay information from a single whisker, and TC input is decoded by barrel regular-spiking (RS cells through a feedforward inhibitory architecture (with inhibition delivered by cortical fast-spiking or FS cells. TC cells encode deflection velocity through population synchrony, while deflection direction is encoded through the distribution of spike counts across the TC population. Barrel RS cells encode both deflection direction and velocity with spike rate, and are divided into functional domains by direction preference. Following repetitive whisker stimulation, system adaptation causes a weakening of synaptic inputs to RS cells and diminishes RS cell spike responses, though evidence suggests that stimulus discrimination may improve following adaptation. In this work, I construct a model of the TC, FS, and RS cells comprising a single barrel system—the model incorporates realistic synaptic connectivity and dynamics and simulates both angular direction (through the spatial pattern of TC activation and velocity (through synchrony of the TC population spikes of a deflection of the primary whisker, and I use the model to examine direction and velocity selectivity of barrel RS cells before and after adaptation. I find that velocity and direction selectivity of individual RS cells (measured over multiple trials sharpens following adaptation, but stimulus discrimination using a simple linear classifier by the RS population response during a single trial (a more biologically meaningful measure than single cell discrimination over multiple trials exhibits strikingly different behavior—velocity discrimination is similar both before and after adaptation, while direction classification improves substantially following adaptation. This is the

  5. Repeated whisker stimulation evokes invariant neuronal responses in the dorsolateral striatum of anesthetized rats: a potential correlate of sensorimotor habits.

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    Mowery, Todd M; Harrold, Jon B; Alloway, Kevin D

    2011-05-01

    The dorsolateral striatum (DLS) receives extensive projections from primary somatosensory cortex (SI), but very few studies have used somesthetic stimulation to characterize the sensory coding properties of DLS neurons. In this study, we used computer-controlled whisker deflections to characterize the extracellular responses of DLS neurons in rats lightly anesthetized with isoflurane. When multiple whiskers were synchronously deflected by rapid back-and-forth movements, whisker-sensitive neurons in the DLS responded to both directions of movement. The latency and magnitude of these neuronal responses displayed very little variation with changes in the rate (2, 5, or 8 Hz) of whisker stimulation. Simultaneous recordings in SI barrel cortex and the DLS revealed important distinctions in the neuronal responses of these serially connected brain regions. In contrast to DLS neurons, SI neurons were activated by the initial deflection of the whiskers but did not respond when the whiskers moved back to their original position. As the rate of whisker stimulation increased, SI responsiveness declined, and the latencies of the responses increased. In fact, when whiskers were deflected at 5 or 8 Hz, many neurons in the DLS responded before the SI neurons. These results and earlier anatomic findings suggest that a component of the sensory-induced response in the DLS is mediated by inputs from the thalamus. Furthermore, the lack of sensory adaptation in the DLS may represent a critical part of the neural mechanism by which the DLS encodes stimulus-response associations that trigger motor habits and other stimulus-evoked behaviors that are not contingent on rewarded outcomes.

  6. Muscular Basis of Whisker Torsion in Mice and Rats.

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    Haidarliu, Sebastian; Bagdasarian, Knarik; Shinde, Namrata; Ahissar, Ehud

    2017-09-01

    Whisking mammals move their whiskers in the rostrocaudal and dorsoventral directions with simultaneous rolling about their long axes (torsion). Whereas muscular control of the first two types of whisker movement was already established, the anatomic muscular substrate of the whisker torsion remains unclear. Specifically, it was not clear whether torsion is induced by asymmetrical operation of known muscles or by other largely unknown muscles. Here, we report that mystacial pads of newborn and adult rats and mice contain oblique intrinsic muscles (OMs) that connect diagonally adjacent vibrissa follicles. Each of the OMs is supplied by a cluster of motor end plates. In rows A and B, OMs connect the ventral part of the rostral follicle with the dorsal part of the caudal follicle. In rows C-E, in contrast, OMs connect the dorsal part of the rostral follicle to the ventral part of the caudal follicle. This inverse architecture is consistent with previous behavioral observations [Knutsen et al.: Neuron 59 (2008) 35-42]. In newborn mice, torsion occurred in irregular single twitches. In adult anesthetized rats, microelectrode mediated electrical stimulation of an individual OM that is coupled with two adjacent whiskers was sufficient to induce a unidirectional torsion of both whiskers. Torsional movement was associated with protracting movement, indicating that in the vibrissal system, like in the ocular system, torsional movement is mechanically coupled to horizontal and vertical movements. This study shows that torsional whisker rotation is mediated by specific OMs whose morphology and attachment sites determine rotation direction and mechanical coupling, and motor innervation determines rotation dynamics. Anat Rec, 300:1643-1653, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  7. Brain-wide map of efferent projections from rat barrel cortex

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    Izabela M. Zakiewicz

    2014-02-01

    Full Text Available The somatotopically organized whisker barrel field of the rat primary somatosensory (S1 cortex is a commonly used model system for anatomical and physiological investigations of sensory processing. The neural connections of the barrel cortex have been extensively mapped. But most investigations have focused on connections to limited regions of the brain, and overviews in the literature of the connections across the brain thus build on a range of material from different laboratories, presented in numerous publications. Furthermore, given the limitations of the conventional journal article format, analyses and interpretations are hampered by lack of access to the underlying experimental data. New opportunities for analyses have emerged with the recent release of an online resource of experimental data consisting of collections of high-resolution images from 6 experiments in which anterograde tracers were injected in S1 whisker or forelimb representations. Building on this material, we have conducted a detailed analysis of the brain wide distribution of the efferent projections of the rat barrel cortex. We compare our findings with the available literature and reports accumulated in the Brain Architecture Management System (BAMS2 database. We report well-known and less known intracortical and subcortical projections of the barrel cortex, as well as distinct differences between S1 whisker and forelimb related projections. Our results correspond well with recently published overviews, but provide additional information about relative differences among S1 projection targets. Our approach demonstrates how collections of shared experimental image data are suitable for brain-wide analysis and interpretation of connectivity mapping data.

  8. Associations of unilateral whisker and olfactory signals induce synapse formation and memory cell recruitment in bilateral barrel cortices: cellular mechanism for unilateral training toward bilateral memory

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    Zilong Gao

    2016-12-01

    Full Text Available Somatosensory signals and operative skills learned by unilateral limbs can be retrieved bilaterally. In terms of cellular mechanism underlying this unilateral learning toward bilateral memory, we hypothesized that associative memory cells in bilateral cortices and synapse innervations between them were produced. In the examination of this hypothesis, we have observed that paired unilateral whisker and odor stimulations led to odorant-induced whisker motions in bilateral sides, which were attenuated by inhibiting the activity of barrel cortices. In the mice that showed bilateral cross-modal responses, the neurons in both sides of barrel cortices became to encode this new odor signal alongside the innate whisker signal. Axon projections and synapse formations from the barrel cortex, which was co-activated with the piriform cortex, toward its contralateral barrel cortex were upregulated. Glutamatergic synaptic transmission in bilateral barrel cortices was upregulated and GABAergic synaptic transmission was downregulated. The associative activations of the sensory cortices facilitate new axon projection, glutamatergic synapse formation and GABAergic synapse downregulation, which drive the neurons to be recruited as associative memory cells in the bilateral cortices. Our data reveals the productions of associative memory cells and synapse innervations in bilateral sensory cortices for unilateral training toward bilateral memory.

  9. A truncated conical beam model for analysis of the vibration of rat whiskers.

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    Yan, Wenyi; Kan, Qianhua; Kergrene, Kenan; Kang, Guozheng; Feng, Xi-Qiao; Rajan, Ramesh

    2013-08-09

    A truncated conical beam model is developed to study the vibration behaviour of a rat whisker. Translational and rotational springs are introduced to better represent the constraint conditions at the base of the whiskers in a living rat. Dimensional analysis shows that the natural frequency of a truncated conical beam with generic spring constraints at its ends is inversely proportional to the square root of the mass density. Under all the combinations of the classical free, pinned, sliding or fixed boundary conditions of a truncated conical beam, it is proved that the natural frequency can be expressed as f = α(rb/L(2))E/ρ and the frequency coefficient α only depends on the ratio of the radii at the two ends of the beam. The natural frequencies of a representative rat whisker are predicted for two typical situations: freely whisking in air and the tip touching an object. Our numerical results show that there exists a window where the natural frequencies of a rat whisker are very sensitive to the change of the rotational constraint at the base. This finding is also confirmed by the numerical results of 18 whiskers with their data available from literature. It can be concluded that the natural frequencies of a rat whisker can be adjusted within a wide range through manipulating the constraints of the follicle on the rat base by a behaving animal. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. LOCALIZATION OF NMDA AND AMPA RECEPTORS IN RAT BARREL FIELD

    NARCIS (Netherlands)

    JAARSMA, D; SEBENS, JB; KORF, J

    1991-01-01

    The aim of this study was to asses the distribution of N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-S-methyl-4-isoxazole propionic acid (AMPA) receptors in the barrel field of rat primary somatosensory (SI) cortex using light-microscopic in vitro autoradiography. NMDA receptors were labeled

  11. Barrels XXIX: Barrels go Hollywood.

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    Evans, Mathew H; Brumberg, Joshua C

    2017-03-01

    Barrels XXIX brought together researchers focusing on the rodent barrel cortex and associated systems. The meeting revolved around three themes: thalamocortical interactions in motor control, touch in rodent, monkey, and humans, and the nature of the multisensory computations the brain makes. Over two days these topics were covered as well as many more presentations that focused on the physiology, behavior, and development of the rodent whisker-to-barrel cortex system.

  12. Repeated whisker stimulation evokes invariant neuronal responses in the dorsolateral striatum of anesthetized rats: a potential correlate of sensorimotor habits

    OpenAIRE

    Mowery, Todd M.; Harrold, Jon B.; Alloway, Kevin D.

    2011-01-01

    The dorsolateral striatum (DLS) receives extensive projections from primary somatosensory cortex (SI), but very few studies have used somesthetic stimulation to characterize the sensory coding properties of DLS neurons. In this study, we used computer-controlled whisker deflections to characterize the extracellular responses of DLS neurons in rats lightly anesthetized with isoflurane. When multiple whiskers were synchronously deflected by rapid back-and-forth movements, whisker-sensitive neur...

  13. Texture coarseness responsive neurons and their mapping in layer 2–3 of the rat barrel cortex in vivo

    Science.gov (United States)

    Garion, Liora; Dubin, Uri; Rubin, Yoav; Khateb, Mohamed; Schiller, Yitzhak; Azouz, Rony; Schiller, Jackie

    2014-01-01

    Texture discrimination is a fundamental function of somatosensory systems, yet the manner by which texture is coded and spatially represented in the barrel cortex are largely unknown. Using in vivo two-photon calcium imaging in the rat barrel cortex during artificial whisking against different surface coarseness or controlled passive whisker vibrations simulating different coarseness, we show that layer 2–3 neurons within barrel boundaries differentially respond to specific texture coarsenesses, while only a minority of neurons responded monotonically with increased or decreased surface coarseness. Neurons with similar preferred texture coarseness were spatially clustered. Multi-contact single unit recordings showed a vertical columnar organization of texture coarseness preference in layer 2–3. These findings indicate that layer 2–3 neurons perform high hierarchical processing of tactile information, with surface coarseness embodied by distinct neuronal subpopulations that are spatially mapped onto the barrel cortex. DOI: http://dx.doi.org/10.7554/eLife.03405.001 PMID:25233151

  14. Rat whisker movement after facial nerve lesion: Evidence for autonomic contraction of skeletal muscle.

    NARCIS (Netherlands)

    Heaton, J.T.; Sheu, S.H.; Hohman, M.H.; Knox, C.J.; Weinberg, J.S.; Kleiss, I.J.; Hadlock, T.A.

    2014-01-01

    Vibrissal whisking is often employed to track facial nerve regeneration in rats; however, we have observed similar degrees of whisking recovery after facial nerve transection with or without repair. We hypothesized that the source of non-facial nerve-mediated whisker movement after chronic

  15. Two whisker motor areas in the rat cortex: evidence from thalamocortical connections.

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    Mohammed, Hisham; Jain, Neeraj

    2014-02-15

    In primates, the motor cortex consists of at least seven different areas, which are involved in movement planning, coordination, initiation, and execution. However, for rats, only the primary motor cortex has been well described. A rostrally located second motor area has been proposed, but its extent, organization, and even definitive existence remain uncertain. Only a rostral forelimb area (RFA) has been definitively described, besides few reports of a rostral hindlimb area. We have previously proposed existence of a second whisker area, which we termed the rostral whisker area (RWA), based on its differential response to intracortical microstimulation compared with the caudal whisker area (CWA) in animals under deep anesthesia (Tandon et al. [2008] Eur J Neurosci 27:228). To establish that RWA is distinct from the caudally contiguous CWA, we determined sources of thalamic inputs to the two proposed whisker areas. Sources of inputs to RFA, caudal forelimb area (CFA), and caudal hindlimb region were determined for comparison. The results show that RWA and CWA can be distinguished based on differences in their thalamic inputs. RWA receives major projections from mediodorsal and ventromedial nuclei, whereas the major projections to CWA are from the ventral anterior, ventrolateral, and posterior nuclei. Moreover, the thalamic nuclei that provide major inputs to RWA are the same as for RFA, and the nuclei projecting to CWA are same as for CFA. The results suggest that rats have a second rostrally located motor area with RWA and RFA as its constituents. Copyright © 2013 Wiley Periodicals, Inc.

  16. Whisker motor cortex reorganization after superior colliculus output suppression in adult rats.

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    Veronesi, Carlo; Maggiolini, Emma; Franchi, Gianfranco

    2013-10-01

    The effect of unilateral superior colliculus (SC) output suppression on the ipsilateral whisker motor cortex (WMC) was studied at different time points after tetrodotoxin and quinolinic acid injections, in adult rats. The WMC output was assessed by mapping the movement evoked by intracortical microstimulation (ICMS) and by recording the ICMS-evoked electromyographic (EMG) responses from contralateral whisker muscles. At 1 h after SC injections, the WMC showed: (i) a strong decrease in contralateral whisker sites, (ii) a strong increase in ipsilateral whisker sites and in ineffective sites, and (iii) a strong increase in threshold current values. At 6 h after injections, the WMC size had shrunk to 60% of the control value and forelimb representation had expanded into the lateral part of the normal WMC. Thereafter, the size of the WMC recovered, returning to nearly normal 12 h later (94% of control) and persisted unchanged over time (1-3 weeks). The ICMS-evoked EMG response area decreased at 1 h after SC lesion and had recovered its baseline value 12 h later. Conversely, the latency of ICMS-evoked EMG responses had increased by 1 h and continued to increase for as long as 3 weeks following the lesion. These findings provide physiological evidence that SC output suppression persistently withdrew the direct excitatory drive from whisker motoneurons and induced changes in the WMC. We suggest that the changes in the WMC are a form of reversible short-term reorganization that is induced by SC lesion. The persistent latency increase in the ICMS-evoked EMG response suggested that the recovery of basic WMC excitability did not take place with the recovery of normal explorative behaviour. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  17. Barrels XXX meeting report: Barrels in Baltimore.

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    Shin, Hyeyoung; Bitzidou, Malamati; Palaguachi, Fernando; Brumberg, Joshua C

    2018-03-01

    The Barrels meeting annually brings together researchers focused on the rodent whisker to cortical barrel system prior to the Society for Neuroscience meeting. The 2017 meeting focused on the classification of cortical interneurons, the role interneurons have in shaping brain dynamics, and finally on the circuitry underlying oral sensations. The meeting highlighted the latest advancements in this rapidly advancing field.

  18. Whisker and Nose Tactile Sense Guide Rat Behavior in a Skilled Reaching Task

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    Pierantonio Parmiani

    2018-02-01

    Full Text Available Skilled reaching is a complex movement in which a forelimb is extended to grasp food for eating. Video-recordings analysis of control rats enables us to distinguish several components of skilled reaching: Orient, approaching the front wall of the reaching box and poking the nose into the slot to locate the food pellet; Transport, advancing the forelimb through the slot to reach-grasp the pellet; and Withdrawal of the grasped food to eat. Although food location and skilled reaching is guided by olfaction, the importance of whisker/nose tactile sense in rats suggests that this too could play a role in reaching behavior. To test this hypothesis, we studied skilled reaching in rats trained in a single-pellet reaching task before and after bilateral whisker trimming and bilateral infraorbital nerve (ION severing. During the task, bilaterally trimmed rats showed impaired Orient with respect to controls. Specifically, they detected the presence of the wall by hitting it with their nose (rather than their whiskers, and then located the slot through repetitive nose touches. The number of nose touches preceding poking was significantly higher in comparison to controls. On the other hand, macrovibrissae trimming resulted in no change in reaching/grasping or withdrawal components of skilled reaching. Bilaterally ION-severed rats, displayed a marked change in the structure of their skilled reaching. With respect to controls, in ION-severed rats: (a approaches to the front wall were significantly reduced at 3–5 and 6–8 days; (b nose pokes were significantly reduced at 3–5 days, and the slot was only located after many repetitive nose touches; (c the reaching-grasping-retracting movement never appeared at 3–5 days; (d explorative paw movements, equal to zero in controls, reached significance at 9–11 days; and (e the restored reaching-grasping-retracting sequence was globally slower than in controls, but the success rate was the same. These findings

  19. Bidirectional Hebbian Plasticity Induced by Low-Frequency Stimulation in Basal Dendrites of Rat Barrel Cortex Layer 5 Pyramidal Neurons.

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    Díez-García, Andrea; Barros-Zulaica, Natali; Núñez, Ángel; Buño, Washington; Fernández de Sevilla, David

    2017-01-01

    According to Hebb's original hypothesis (Hebb, 1949), synapses are reinforced when presynaptic activity triggers postsynaptic firing, resulting in long-term potentiation (LTP) of synaptic efficacy. Long-term depression (LTD) is a use-dependent decrease in synaptic strength that is thought to be due to synaptic input causing a weak postsynaptic effect. Although the mechanisms that mediate long-term synaptic plasticity have been investigated for at least three decades not all question have as yet been answered. Therefore, we aimed at determining the mechanisms that generate LTP or LTD with the simplest possible protocol. Low-frequency stimulation of basal dendrite inputs in Layer 5 pyramidal neurons of the rat barrel cortex induces LTP. This stimulation triggered an EPSP, an action potential (AP) burst, and a Ca 2+ spike. The same stimulation induced LTD following manipulations that reduced the Ca 2+ spike and Ca 2+ signal or the AP burst. Low-frequency whisker deflections induced similar bidirectional plasticity of action potential evoked responses in anesthetized rats. These results suggest that both in vitro and in vivo similar mechanisms regulate the balance between LTP and LTD. This simple induction form of bidirectional hebbian plasticity could be present in the natural conditions to regulate the detection, flow, and storage of sensorimotor information.

  20. Bidirectional Hebbian Plasticity Induced by Low-Frequency Stimulation in Basal Dendrites of Rat Barrel Cortex Layer 5 Pyramidal Neurons

    Science.gov (United States)

    Díez-García, Andrea; Barros-Zulaica, Natali; Núñez, Ángel; Buño, Washington; Fernández de Sevilla, David

    2017-01-01

    According to Hebb's original hypothesis (Hebb, 1949), synapses are reinforced when presynaptic activity triggers postsynaptic firing, resulting in long-term potentiation (LTP) of synaptic efficacy. Long-term depression (LTD) is a use-dependent decrease in synaptic strength that is thought to be due to synaptic input causing a weak postsynaptic effect. Although the mechanisms that mediate long-term synaptic plasticity have been investigated for at least three decades not all question have as yet been answered. Therefore, we aimed at determining the mechanisms that generate LTP or LTD with the simplest possible protocol. Low-frequency stimulation of basal dendrite inputs in Layer 5 pyramidal neurons of the rat barrel cortex induces LTP. This stimulation triggered an EPSP, an action potential (AP) burst, and a Ca2+ spike. The same stimulation induced LTD following manipulations that reduced the Ca2+ spike and Ca2+ signal or the AP burst. Low-frequency whisker deflections induced similar bidirectional plasticity of action potential evoked responses in anesthetized rats. These results suggest that both in vitro and in vivo similar mechanisms regulate the balance between LTP and LTD. This simple induction form of bidirectional hebbian plasticity could be present in the natural conditions to regulate the detection, flow, and storage of sensorimotor information. PMID:28203145

  1. Spiking in primary somatosensory cortex during natural whisking in awake head-restrained rats is cell-type specific

    NARCIS (Netherlands)

    de Kock, C.P.J.; Sakmann, B.

    2009-01-01

    Sensation involves active movement of sensory organs, but it remains unknown how position or movement of sensory organs is encoded in cortex. In the rat whisker system, each whisker is represented by an individual cortical (barrel) column. Here, we quantified in awake, head-fixed rats the impact of

  2. Cortical Local Field Potential Power Is Associated with Behavioral Detection of Near-threshold Stimuli in the Rat Whisker System: Dissociation between Orbitofrontal and Somatosensory Cortices.

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    Rickard, Rachel E; Young, Andrew M J; Gerdjikov, Todor V

    2018-01-01

    There is growing evidence that ongoing brain oscillations may represent a key regulator of attentional processes and as such may contribute to behavioral performance in psychophysical tasks. OFC appears to be involved in the top-down modulation of sensory processing; however, the specific contribution of ongoing OFC oscillations to perception has not been characterized. Here we used the rat whiskers as a model system to further characterize the relationship between cortical state and tactile detection. Head-fixed rats were trained to report the presence of a vibrotactile stimulus (frequency = 60 Hz, duration = 2 sec, deflection amplitude = 0.01-0.5 mm) applied to a single vibrissa. We calculated power spectra of local field potentials preceding the onset of near-threshold stimuli from microelectrodes chronically implanted in OFC and somatosensory cortex. We found a dissociation between slow oscillation power in the two regions in relation to detection probability: Higher OFC but not somatosensory delta power was associated with increased detection probability. Furthermore, coherence between OFC and barrel cortex was reduced preceding successful detection. Consistent with the role of OFC in attention, our results identify a cortical network whose activity is differentially modulated before successful tactile detection.

  3. Rat whisker movement after facial nerve lesion: evidence for autonomic contraction of skeletal muscle.

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    Heaton, James T; Sheu, Shu Hsien; Hohman, Marc H; Knox, Christopher J; Weinberg, Julie S; Kleiss, Ingrid J; Hadlock, Tessa A

    2014-04-18

    Vibrissal whisking is often employed to track facial nerve regeneration in rats; however, we have observed similar degrees of whisking recovery after facial nerve transection with or without repair. We hypothesized that the source of non-facial nerve-mediated whisker movement after chronic denervation was from autonomic, cholinergic axons traveling within the infraorbital branch of the trigeminal nerve (ION). Rats underwent unilateral facial nerve transection with repair (N=7) or resection without repair (N=11). Post-operative whisking amplitude was measured weekly across 10weeks, and during intraoperative stimulation of the ION and facial nerves at ⩾18weeks. Whisking was also measured after subsequent ION transection (N=6) or pharmacologic blocking of the autonomic ganglia using hexamethonium (N=3), and after snout cooling intended to elicit a vasodilation reflex (N=3). Whisking recovered more quickly and with greater amplitude in rats that underwent facial nerve repair compared to resection (Pfacial-nerve-mediated whisking was elicited by electrical stimulation of the ION, temporarily diminished following hexamethonium injection, abolished by transection of the ION, and rapidly and significantly (Pfacial nerve resection. This study provides the first behavioral and anatomical evidence of spontaneous autonomic innervation of skeletal muscle after motor nerve lesion, which not only has implications for interpreting facial nerve reinnervation results, but also calls into question whether autonomic-mediated innervation of striated muscle occurs naturally in other forms of neuropathy. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  4. Whisker Deprivation Drives Two Phases of Inhibitory Synapse Weakening in Layer 4 of Rat Somatosensory Cortex.

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    Melanie A Gainey

    Full Text Available Inhibitory synapse development in sensory neocortex is experience-dependent, with sustained sensory deprivation yielding fewer and weaker inhibitory synapses. Whether this represents arrest of synapse maturation, or a more complex set of processes, is unclear. To test this, we measured the dynamics of inhibitory synapse development in layer 4 of rat somatosensory cortex (S1 during continuous whisker deprivation from postnatal day 7, and in age-matched controls. In deprived columns, spontaneous miniature inhibitory postsynaptic currents (mIPSCs and evoked IPSCs developed normally until P15, when IPSC amplitude transiently decreased, recovering by P16 despite ongoing deprivation. IPSCs remained normal until P22, when a second, sustained phase of weakening began. Delaying deprivation onset by 5 days prevented the P15 weakening. Both early and late phase weakening involved measurable reduction in IPSC amplitude relative to prior time points. Thus, deprivation appears to drive two distinct phases of active IPSC weakening, rather than simple arrest of synapse maturation.

  5. Late emergence of the vibrissa direction selectivity map in the rat barrel cortex.

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    Kremer, Yves; Léger, Jean-François; Goodman, Dan; Brette, Romain; Bourdieu, Laurent

    2011-07-20

    In the neocortex, neuronal selectivities for multiple sensorimotor modalities are often distributed in topographical maps thought to emerge during a restricted period in early postnatal development. Rodent barrel cortex contains a somatotopic map for vibrissa identity, but the existence of maps representing other tactile features has not been clearly demonstrated. We addressed the issue of the existence in the rat cortex of an intrabarrel map for vibrissa movement direction using in vivo two-photon imaging. We discovered that the emergence of a direction map in rat barrel cortex occurs long after all known critical periods in the somatosensory system. This map is remarkably specific, taking a pinwheel-like form centered near the barrel center and aligned to the barrel cortex somatotopy. We suggest that this map may arise from intracortical mechanisms and demonstrate by simulation that the combination of spike-timing-dependent plasticity at synapses between layer 4 and layer 2/3 and realistic pad stimulation is sufficient to produce such a map. Its late emergence long after other classical maps suggests that experience-dependent map formation and refinement continue throughout adult life.

  6. Developmental Changes in Sensory-Evoked Optical Intrinsic Signals in the Rat Barrel Cortex

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    Mikhail Sintsov

    2017-12-01

    Full Text Available Optical Intrinsic Signal imaging (OISi is a powerful technique for optical brain studies. OIS mainly reflects the hemodynamic response (HR and metabolism, but it may also involve changes in tissue light scattering (LS caused by transient cellular swelling in the active tissue. Here, we explored the developmental features of sensory-evoked OIS in the rat barrel cortex during the first 3 months after birth. Multispectral OISi revealed that two temporally distinct components contribute to the neonatal OIS: an early phase of LS followed by a late phase of HR. The contribution of LS to the early response was also evidenced by an increase in light transmission through the active barrel. The early OIS phase correlated in time and amplitude with the sensory-evoked electrophysiological response. Application of the Modified Beer-Lambert Law (MBLL to the OIS data revealed that HR during the early phase involved only a slight decrease in blood oxygenation without any change in blood volume. In contrast, HR during the late phase manifested an adult-like increase in blood volume and oxygenation. During development, the peak time of the delayed HR progressively shortened with age, nearly reaching the stimulus onset and overlapping with the early LS phase by the fourth postnatal week. Thus, LS contributes to the sensory-evoked OIS in the barrel cortex of rats at all ages, and it dominates the early OIS phase in neonatal rats due to delayed HR. Our results are also consistent with the delayed blood oxygen level dependent (BOLD signal in human preterm infants.

  7. Ethanolic extract of Astragali radix and Salviae radix prohibits oxidative brain injury by psycho-emotional stress in whisker removal rat model.

    Directory of Open Access Journals (Sweden)

    Hyeong-Geug Kim

    Full Text Available Myelophil, an ethanolic extract of Astragali Radix and Salviae Radix, has been clinically used to treat chronic fatigue and stress related disorders in South Korea. In this study, we investigated the protective effects of Myelophil on a whisker removal-induced psycho-emotional stress model. SD rats were subjected to whisker removal after oral administration of Myelophil or ascorbic acid for consecutive 4 days. Whisker removal considerably increased total reactive oxygen species in serum levels as well as cerebral cortex and hippocampal regions in brain tissues. Lipidperoxidation levels were also increased in the cerebral cortex, hippocampus regions, and brain tissue injuries as shown in histopathology and immunohistochemistry. However, Myelophil significantly ameliorated these alterations, and depletion of glutathione contents in both cerebral cortex and hippocampus regions respectively. Serum levels of corticosterone and adrenaline were notably altered after whisker removal stress, whereas these abnormalities were significantly normalized by pre-treatment with Myelophil. The NF-κB was notably activated in both cerebral cortex and hippocampus after whisker removal stress, while it was efficiently blocked by pre-treatment with Myelophil. Myelophil also significantly normalizes alterations of tumor necrosis factor-α, interleukin (IL-1β, IL-6 and interferon-γ in both gene expressions and protein levels. These results suggest that Myelophil has protective effects on brain damages in psycho-emotional stress, and the underlying mechanisms involve regulation of inflammatory proteins, especially NF-κB modulation.

  8. Molecular Correlates of Cortical Network Modulation by Long-Term Sensory Experience in the Adult Rat Barrel Cortex

    Science.gov (United States)

    Vallès, Astrid; Granic, Ivica; De Weerd, Peter; Martens, Gerard J. M.

    2014-01-01

    Modulation of cortical network connectivity is crucial for an adaptive response to experience. In the rat barrel cortex, long-term sensory stimulation induces cortical network modifications and neuronal response changes of which the molecular basis is unknown. Here, we show that long-term somatosensory stimulation by enriched environment…

  9. A new paradigm for the reversible blockage of whisker sensory transmission.

    Science.gov (United States)

    Gener, Thomas; Reig, Ramon; Sanchez-Vives, Maria V

    2009-01-30

    The objective of this study was to explore a paradigm that would allow a temporary deprivation of whisker information lasting for a few hours. An additional requirement was to be non-invasive in order to be usable in awake chronically implanted rats without inducing stress. With that aim, electrophysiological recordings from the barrel cortex of anesthetized rats were obtained. The pressure of an air-puff (5-10 ms) delivered to the whiskers was adjusted to evoke a consistent response of around 100 microV (extracellular) or approximately 5 mV (intracellular) in the contralateral cortex. Lidocaine was then locally applied in different forms (cream, local injection, aerosol, drops) and concentrations (2-10%) to the base of the whiskers. The stimulus-induced response was monitored once every 5s for several hours (3-6h) in order to characterize its course of action. Local injection of lidocaine induced the fastest and most complete blockage, but was ruled out for being invasive. Out of the remaining forms of application, a lidocaine drop (0.4 ml, 10%) to the base of the whiskers was found to induce a reliable blockage (to an average 9% the original response). The maximum effect was reached after 150-200 min, and the response was totally recovered approximately 300 min after lidocaine application. This characterization should be useful to induce an efficient, short term and reversible blockage of whisker sensory transmission in both anesthetized and awake preparations, while not causing stress in an awake animal.

  10. Multiple blocks of intermittent and continuous theta-burst stimulation applied via transcranial magnetic stimulation differently affect sensory responses in rat barrel cortex.

    Science.gov (United States)

    Thimm, Andreas; Funke, Klaus

    2015-02-15

    Theta-burst stimulation (TBS) applied via transcranial magnetic stimulation is able to modulate human cortical excitability. Here we investigated in a rat model how two different forms of TBS, intermittent (iTBS) and continuous (cTBS), affect sensory responses in rat barrel cortex. We found that iTBS but less cTBS promoted late (>18 ms) sensory response components while not affecting the earliest response (8-18 ms). The effect increased with each of the five iTBS blocks applied. cTBS somewhat reduced the early response component after the first block but had a similar effect as iTBS after four to five blocks. We conclude that iTBS primarly modulates the activity of (inhibitory) cortical interneurons while cTBS may first reduce general neuronal excitability with a single block but reverse to iTBS-like effects with application of several blocks. Cortical sensory processing varies with cortical state and the balance of inhibition to excitation. Repetitive transcranial magnetic stimulation (rTMS) has been shown to modulate human cortical excitability. In a rat model, we recently showed that intermittent theta-burst stimulation (iTBS) applied to the corpus callosum, to activate primarily supragranular cortical pyramidal cells but fewer subcortical neurons, strongly reduced the cortical expression of parvalbumin (PV), indicating reduced activity of fast-spiking interneurons. Here, we used the well-studied rodent barrel cortex system to test how iTBS and continuous TBS (cTBS) modulate sensory responses evoked by either single or double stimuli applied to the principal (PW) and/or adjacent whisker (AW) in urethane-anaesthetized rats. Compared to sham stimulation, iTBS but not cTBS particularly enhanced late (>18 ms) response components of multi-unit spiking and local field potential responses in layer 4 but not the very early response (iTBS diminished the suppression of the second response evoked by paired PW or AW-PW stimulation at 20 ms intervals. The effects

  11. Localization of Myosin and Actin in the Pelage and Whisker Hair Follicles of Rat

    International Nuclear Information System (INIS)

    Morioka, Kiyokazu; Matsuzaki, Toshiyuki; Takata, Kuniaki

    2006-01-01

    The combined effects of myosin II and actin enable muscle and nonmuscle cells to generate forces required for muscle contraction, cell division, cell migration, cellular morphological changes, the maintenance of cellular tension and polarity, and so on. However, except for the case of muscle contraction, the details are poorly understood. We focus on nonmuscle myosin and actin in the formation and maintenance of hair and skin, which include highly active processes in mammalian life with respect to the cellular proliferation, differentiation, and movement. The localization of nonmuscle myosin II and actin in neonatal rat dorsal skin, mystacial pad, hair follicles, and vibrissal follicles was studied by immunohistochemical technique to provide the basis for the elucidation of the roles of these proteins. Specificities of the antibodies were verified by using samples from the relevant tissues and subjecting them to immunoblotting test prior to morphological analyses. The myosin and actin were abundant and colocalized in the spinous and granular layers but scarce in the basal layer of the dorsal and mystacial epidermis. In hair and vibrissal follicles, nonmuscle myosin and actin were colocalized in the outer root sheath and some hair matrix cells adjoining dermal papillae. In contrast, most areas of the inner root sheath and hair matrix appeared to comprise very small amounts of myosin and actin. Hair shaft may comprise significant myosin during the course of its keratinization. These results suggest that the actin-myosin system plays a part in cell movement, differentiation, protection and other key functions of skin and hair cells

  12. The influence of vibrissal somatosensory processing in rat superior colliculus on prey capture.

    Science.gov (United States)

    Favaro, P D N; Gouvêa, T S; de Oliveira, S R; Vautrelle, N; Redgrave, P; Comoli, E

    2011-03-10

    The lateral part of intermediate layer of superior colliculus (SCl) is a critical substrate for successful predation by rats. Hunting-evoked expression of the activity marker Fos is concentrated in SCl while prey capture in rats with NMDA lesions in SCl is impaired. Particularly affected are rapid orienting and stereotyped sequences of actions associated with predation of fast moving prey. Such deficits are consistent with the view that the deep layers of SC are important for sensory guidance of movement. Although much of the relevant evidence involves visual control of movement, less is known about movement guidance by somatosensory input from vibrissae. Indeed, our impression is that prey contact with whiskers is a likely stimulus to trigger predation. Moreover, SCl receives whisker and orofacial somatosensory information directly from trigeminal complex, and indirectly from zona incerta, parvicelular reticular formation and somatosensory barrel cortex. To better understand sensory guidance of predation by vibrissal information we investigated prey capture by rats after whisker removal and the role of superior colliculus (SC) by comparing Fos expression after hunting with and without whiskers. Rats were allowed to hunt cockroaches, after which their whiskers were removed. Two days later they were allowed to hunt cockroaches again. Without whiskers the rats were less able to retain the cockroaches after capture and less able to pursue them in the event of the cockroach escaping. The predatory behaviour of rats with re-grown whiskers returned to normal. In parallel, Fos expression in SCl induced by predation was significantly reduced in whiskerless animals. We conclude that whiskers contribute to the efficiency of rat prey capture and that the loss of vibrissal input to SCl, as reflected by reduced Fos expression, could play a critical role in predatory deficits of whiskerless rats. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

  13. Anatomical pathways involved in generating and sensing rhythmic whisker movements

    Directory of Open Access Journals (Sweden)

    Laurens W.J. Bosman

    2011-10-01

    Full Text Available The rodent whisker system is widely used as a model system for investigating sensorimotor integration, neural mechanisms of complex cognitive tasks, neural development, and robotics. The whisker pathways to the barrel cortex have received considerable attention. However, many subcortical structures are paramount to the whisker system. They contribute to important processes, like filtering out salient features, integration with other senses and adaptation of the whisker system to the general behavioral state of the animal. We present here an overview of the brain regions and their connections involved in the whisker system. We do not only describe the anatomy and functional roles of the cerebral cortex, but also those of subcortical structures like the striatum, superior colliculus, cerebellum, pontomedullary reticular formation, zona incerta and anterior pretectal nucleus as well as those of level setting systems like the cholinergic, histaminergic, serotonergic and noradrenergic pathways. We conclude by discussing how these brain regions may affect each other and how they together may control the precise timing of whisker movements and coordinate whisker perception.

  14. Feedforward motor information enhances somatosensory responses and sharpens angular tuning of rat S1 barrel cortex neurons.

    Science.gov (United States)

    Khateb, Mohamed; Schiller, Jackie; Schiller, Yitzhak

    2017-01-06

    The primary vibrissae motor cortex (vM1) is responsible for generating whisking movements. In parallel, vM1 also sends information directly to the sensory barrel cortex (vS1). In this study, we investigated the effects of vM1 activation on processing of vibrissae sensory information in vS1 of the rat. To dissociate the vibrissae sensory-motor loop, we optogenetically activated vM1 and independently passively stimulated principal vibrissae. Optogenetic activation of vM1 supra-linearly amplified the response of vS1 neurons to passive vibrissa stimulation in all cortical layers measured. Maximal amplification occurred when onset of vM1 optogenetic activation preceded vibrissa stimulation by 20 ms. In addition to amplification, vM1 activation also sharpened angular tuning of vS1 neurons in all cortical layers measured. Our findings indicated that in addition to output motor signals, vM1 also sends preparatory signals to vS1 that serve to amplify and sharpen the response of neurons in the barrel cortex to incoming sensory input signals.

  15. A novel biomimetic whisker technology based on fiber Bragg grating and its application

    Science.gov (United States)

    Zhao, Chenlu; Jiang, Qi; Li, Yibin

    2017-09-01

    The paper describes a novel, biomimetic whisker-based sensing technology following the basic design of the facial whiskers of animals such as rats and mice. The sensor consists of a 3× 2 whisker array on each side of a robot. In experiments with the artificial whiskers, the motor drives rotating whiskers, and the center wavelength of a fiber Bragg grating pasted on the whisker will shift when the whisker touches an obstacle. The distance will be obtained by processing the wavelength shift data with algorithms. Then the shape recognition can be realized by postprocessing the distance data. The experimental results prove that the whisker array is capable of accurately gathering the distance and shape information of an object.

  16. Real-Time Million-Synapse Simulation of Rat Barrel Cortex

    Directory of Open Access Journals (Sweden)

    Thomas eSharp

    2014-05-01

    Full Text Available Simulations of neural circuits are bounded in scale and speed by available computing resources, and particularly by the differences in parallelism and communication patterns between the brain and high-performance computers. SpiNNaker is a computer architecture designed to address this problem by emulating the structure and function of neural tissue, using very many low-power processors and an interprocessor communication mechanism inspired by axonal arbors. Here we demonstrate that thousand-processor SpiNNaker prototypes can simulate models of the rodent barrel system comprising fifty thousand neurons and fifty million synapses. We use the PyNN library to specify models, and the intrinsic features of Python to control experimental procedures and analysis. The models reproduce known thalamocortical response transformations, exhibit known, balanced dynamics of excitation and inhibition, and show a spatiotemporal spread of activity though the superficial cortical layers. These demonstrations are a significant step towards tractable simulations of entire cortical areas on the million-processor SpiNNaker machines in development.

  17. Real-time million-synapse simulation of rat barrel cortex.

    Science.gov (United States)

    Sharp, Thomas; Petersen, Rasmus; Furber, Steve

    2014-01-01

    Simulations of neural circuits are bounded in scale and speed by available computing resources, and particularly by the differences in parallelism and communication patterns between the brain and high-performance computers. SpiNNaker is a computer architecture designed to address this problem by emulating the structure and function of neural tissue, using very many low-power processors and an interprocessor communication mechanism inspired by axonal arbors. Here we demonstrate that thousand-processor SpiNNaker prototypes can simulate models of the rodent barrel system comprising 50,000 neurons and 50 million synapses. We use the PyNN library to specify models, and the intrinsic features of Python to control experimental procedures and analysis. The models reproduce known thalamocortical response transformations, exhibit known, balanced dynamics of excitation and inhibition, and show a spatiotemporal spread of activity though the superficial cortical layers. These demonstrations are a significant step toward tractable simulations of entire cortical areas on the million-processor SpiNNaker machines in development.

  18. Cultured embryonic non-innervated mouse muzzle is capable of generating a whisker pattern.

    Science.gov (United States)

    Andrés, F L; Van Der Loos, H

    1983-01-01

    The whisker pattern on the muzzle of the mouse is mapped in the contralateral parietal neocortex, each whisker follicle projecting to its own multineuronal unit ('barrel'). To determine the role, if any, of the peripheral innervation in the establishment of the vibrissal array, we cultured non-innervated prospective whiskerpads from 9- and 10-day-old embryos, mostly on chorioallantoic membrane. The results show that skin, alone, is capable of generating the whisker pattern, thus adducing a strong argument for the hypothesis that the central brain maps have their origin in the periphery. Copyright © 1983. Published by Elsevier Ltd.

  19. Optogenetic conditioning of paradigm and pattern discrimination in the rat somatosensory system.

    Directory of Open Access Journals (Sweden)

    Kenta Abe

    Full Text Available The rodent whisker-barrel cortical system is a model for studying somatosensory discrimination at high spatiotemporal precision. Here, we applied optogenetics to produce somatosensory inputs in the whisker area using one of transgenic rat lines, W-TChR2V4, which expresses channelrhodopsin-2 (ChR2 in the mechanoreceptive nerve endings around whisker follicles. An awake W-TChR2V4 rat was head-fixed and irradiated by blue LED light on the whisker area with a paradigm conditioned with a reward. The Go task was designed so the rat is allowed to receive a reward, when it licked the nozzle within 5 s after photostimulation. The No-go task was designed so as the rat has to withhold licking for at least 5 s to obtain a reward after photostimulation. The Go-task conditioning was established within 1 hr of training with a reduction in the reaction time and increase of the success rate. To investigate the relationship between the spatiotemporal pattern of sensory inputs and the behavioral output, we designed a multi-optical fiber system that irradiates the whisker area at 9 spots in a 3×3 matrix. Although the Go-task conditioning was established using synchronous irradiation of 9 spots, the success rate was decreased with an increase of the reaction time for the asynchronous irradiation. After conditioning to the Go task, the rat responded to the blue LED flash irradiated on the barrel cortex, where many neurons also express ChR2, or photostimulation of the contralateral whisker area with a similar reaction time and success rate. Synchronous activation of the peripheral mechanoreceptive nerves is suggested to drive a neural circuit in the somatosensory cortex that efficiently couples with the decision. Our optogenetic system would enable the precise evaluation of the psychophysical values, such as the reaction time and success rate, to gain some insight into the brain mechanisms underlying conditioned behaviors.

  20. Efficacy and connectivity of intracolumnar pairs of layer 2/3 pyramidal cells in the barrel cortex of juvenile rats

    Science.gov (United States)

    Feldmeyer, Dirk; Lübke, Joachim; Sakmann, Bert

    2006-01-01

    Synaptically coupled layer 2/3 (L2/3) pyramidal neurones located above the same layer 4 barrel (‘barrel-related’) were investigated using dual whole-cell voltage recordings in acute slices of rat somatosensory cortex. Recordings were followed by reconstructions of biocytin-filled neurones. The onset latency of unitary EPSPs was 1.1 ± 0.4 ms, the 20–80% rise time was 0.7 ± 0.2 ms, the average amplitude was 1.0 ± 0.7 mV and the decay time constant was 15.7 ± 4.5 ms. The coefficient of variation (c.v.) of unitary EPSP amplitudes decreased with increasing EPSP peak and was 0.33 ± 0.18. Bursts of APs in the presynaptic pyramidal cell resulted in EPSPs that, over a wide range of frequencies (5–100 Hz), displayed amplitude depression. Anatomically the barrel-related pyramidal cells in the lower half of layer 2/3 have a long apical dendrite with a small terminal tuft, while pyramidal cells in the upper half of layer 2/3 have shorter and often more ‘irregularly’ shaped apical dendrites that branch profusely in layer 1. The number of putative excitatory synaptic contacts established by the axonal collaterals of a L2/3 pyramidal cell with a postsynaptic pyramidal cell in the same column varied between 2 and 4, with an average of 2.8 ± 0.7 (n = 8 pairs). Synaptic contacts were established predominantly on the basal dendrites at a mean geometric distance of 91 ± 47 μm from the pyramidal cell soma. L2/3-to-L2/3 connections formed a blob-like innervation domain containing 2.8 mm of the presynaptic axon collaterals with a bouton density of 0.3 boutons per μm axon. Within the supragranular layers of its home column a single L2/3 pyramidal cell established about 900 boutons suggesting that 270 pyramidal cells in layer 2/3 are innervated by an individual pyramidal cell. In turn, a single pyramidal cell received synaptic inputs from 270 other L2/3 pyramidal cells. The innervation domain of L2/3-to-L2/3 connections superimposes almost exactly with that of L4-to-L2

  1. High-resolution 2-deoxyglucose mapping of functional cortical columns in mouse barrel cortex.

    Science.gov (United States)

    McCasland, J S; Woolsey, T A

    1988-12-22

    Cortical columns associated with barrels in layer IV of the somatosensory cortex were characterized by high-resolution 2-deoxy-D-glucose (2DG) autoradiography in freely behaving mice. The method demonstrates a more exact match between columnar labeling and cytoarchitectonic barrel boundaries than previously reported. The pattern of cortical activation seen with stimulation of a single whisker (third whisker in the middle row of large hairs--C3) was compared with the patterns from two control conditions--normal animals with all whiskers present ("positive control")--and with all large whiskers clipped ("negative control"). Two types of measurements were made from 2DG autoradiograms of tangential cortical sections: 1) labeled cells were identified by eye and tabulated with a computer, and 2) grain densities were obtained automatically with a computer-controlled microscope and image processor. We studied the fine-grained patterns of 2DG labeling in a nine-barrel grid with the C3 barrel in the center. From the analysis we draw five major conclusions. 1. Approximately 30-40% of the total number of neurons in the C3 barrel column are activated when only the C3 whisker is stimulated. This is about twice the number of neurons labeled in the C3 column when all whiskers are stimulated and about ten times the number of neurons labeled when all large whiskers are clipped. 2. There is evidence for a vertical functional organization within a barrel-related whisker column which has smaller dimensions in the tangential direction than a barrel. There are densely labeled patches within a barrel which are unique to an individual cortex. The same patchy pattern is found in the appropriate regions of sections above and below the barrels through the full thickness of the cortex. This functional arrangement could be considered to be a "minicolumn" or more likely a group of "minicolumns" (Mountcastle: In G.M. Edelman and U.B. Mountcastle (eds): The Material Brain: Cortical Organization

  2. Response sensitivity of barrel neuron subpopulations to simulated thalamic input.

    Science.gov (United States)

    Pesavento, Michael J; Rittenhouse, Cynthia D; Pinto, David J

    2010-06-01

    Our goal is to examine the relationship between neuron- and network-level processing in the context of a well-studied cortical function, the processing of thalamic input by whisker-barrel circuits in rodent neocortex. Here we focus on neuron-level processing and investigate the responses of excitatory and inhibitory barrel neurons to simulated thalamic inputs applied using the dynamic clamp method in brain slices. Simulated inputs are modeled after real thalamic inputs recorded in vivo in response to brief whisker deflections. Our results suggest that inhibitory neurons require more input to reach firing threshold, but then fire earlier, with less variability, and respond to a broader range of inputs than do excitatory neurons. Differences in the responses of barrel neuron subtypes depend on their intrinsic membrane properties. Neurons with a low input resistance require more input to reach threshold but then fire earlier than neurons with a higher input resistance, regardless of the neuron's classification. Our results also suggest that the response properties of excitatory versus inhibitory barrel neurons are consistent with the response sensitivities of the ensemble barrel network. The short response latency of inhibitory neurons may serve to suppress ensemble barrel responses to asynchronous thalamic input. Correspondingly, whereas neurons acting as part of the barrel circuit in vivo are highly selective for temporally correlated thalamic input, excitatory barrel neurons acting alone in vitro are less so. These data suggest that network-level processing of thalamic input in barrel cortex depends on neuron-level processing of the same input by excitatory and inhibitory barrel neurons.

  3. Precision rodent whisker stimulator with integrated servo-locked control and displacement measurement.

    Science.gov (United States)

    Walker, Jennifer L; Monjaraz-Fuentes, Fernanda; Pedrow, Christi R; Rector, David M

    2011-03-15

    We developed a high speed voice coil based whisker stimulator that delivers precise deflections of a single whisker or group of whiskers in a repeatable manner. The device is miniature, quiet, and inexpensive to build. Multiple stimulators fit together for independent stimulation of four or more whiskers. The system can be used with animals under anesthesia as well as awake animals with head-restraint, and does not require trimming the whiskers. The system can deliver 1-2 mm deflections in 2 ms resulting in velocities up to 900 mm/s to attain a wide range of evoked responses. Since auditory artifacts can influence behavioral studies using whisker stimulation, we tested potential effects of auditory noise by recording somatosensory evoked potentials (SEP) with varying auditory click levels, and with/without 80 dBa background white noise. We found that auditory clicks as low as 40 dBa significantly influence the SEP. With background white noise, auditory clicks as low as 50 dBa were still detected in components of the SEP. For behavioral studies where animals must learn to respond to whisker stimulation, these sounds must be minimized. Together, the stimulator and data system can be used for psychometric vigilance tasks, mapping of the barrel cortex and other electrophysiological paradigms. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Mystacial Whisker Layout and Musculature in the Guinea Pig (Cavia porcellus): A Social, Diurnal Mammal.

    Science.gov (United States)

    Grant, Robyn A; Delaunay, Mariane G; Haidarliu, Sebastian

    2017-03-01

    All mammals (apart from apes and humans) have whiskers that make use of a similar muscle arrangement. Whisker specialists, such as rats and mice, tend to be nocturnal and arboreal, relying on their whisker sense of touch to guide exploration around tree canopies at night. As such, nocturnal arboreal rodents have many whiskers that are organised into a grid-like pattern, and moved using a complex array of muscles. Indeed, most arboreal, nocturnal mammals tend to have specialised whiskers that are longer and arranged in a dense, regular grid, compared with terrestrial, diurnal mammals. The guinea pig diverged early from murid rodents (around 75 million years ago), and are ground-dwelling, diurnal animals. It would be predicted that, as a terrestrial mammal, they may have less whiskers and a reduced muscle architecture compared to arboreal, nocturnal rodents. We examined the mystacial whisker layout, musculature and movement capacity of Guinea pig (Cavia porcellus) whiskers and found that they did indeed have a disorganized whisker layout, with a fortification around the eye area. In addition, there was a reduction in musculature, especially in the intrinsic muscles. Despite guinea pigs not cyclically moving their whiskers, the mystacial musculature was still very similar to that of murid rodents. We suggest that the conserved presence of whisker layout and musculature, even in visual mammals such as primates and guinea pigs, may indicate that whiskers still play an important role in these animals, including protecting the eyes and being involved in tactile social behaviors. Anat Rec, 300:527-536, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. Membrane potential correlates of sensory perception in mouse barrel cortex.

    Science.gov (United States)

    Sachidhanandam, Shankar; Sreenivasan, Varun; Kyriakatos, Alexandros; Kremer, Yves; Petersen, Carl C H

    2013-11-01

    Neocortical activity can evoke sensory percepts, but the cellular mechanisms remain poorly understood. We trained mice to detect single brief whisker stimuli and report perceived stimuli by licking to obtain a reward. Pharmacological inactivation and optogenetic stimulation demonstrated a causal role for the primary somatosensory barrel cortex. Whole-cell recordings from barrel cortex neurons revealed membrane potential correlates of sensory perception. Sensory responses depended strongly on prestimulus cortical state, but both slow-wave and desynchronized cortical states were compatible with task performance. Whisker deflection evoked an early (sensory response that was encoded through cell-specific reversal potentials. A secondary late (50-400 ms) depolarization was enhanced on hit trials compared to misses. Optogenetic inactivation revealed a causal role for late excitation. Our data reveal dynamic processing in the sensory cortex during task performance, with an early sensory response reliably encoding the stimulus and later secondary activity contributing to driving the subjective percept.

  6. Tin Whisker Testing and Modeling

    Science.gov (United States)

    2015-11-01

    to 25°C/85%RH. The greatest whisker nucleation and growth occurred on the Cu alloy lead terminations. During high humidity isothermal exposure...Circuits, Lead-Free Solder, Electronic Assembly, Humidity Exposure, Thermal Cycling, Corrosion, Contamination, Whisker Length Statistics 16. SECURITY...rework fluxes, and immersion Sn finished Cu circuit board pads. The assemblies were exposed to various thermal cycling and isothermal high humidity and

  7. Patchwork-Type Spontaneous Activity in Neonatal Barrel Cortex Layer 4 Transmitted via Thalamocortical Projections

    Directory of Open Access Journals (Sweden)

    Hidenobu Mizuno

    2018-01-01

    Full Text Available Summary: Establishment of precise neuronal connectivity in the neocortex relies on activity-dependent circuit reorganization during postnatal development; however, the nature of cortical activity during this period remains largely unknown. Using two-photon calcium imaging of the barrel cortex in vivo during the first postnatal week, we reveal that layer 4 (L4 neurons within the same barrel fire synchronously in the absence of peripheral stimulation, creating a “patchwork” pattern of spontaneous activity corresponding to the barrel map. By generating transgenic mice expressing GCaMP6s in thalamocortical axons, we show that thalamocortical axons also demonstrate the spontaneous patchwork activity pattern. Patchwork activity is diminished by peripheral anesthesia but is mostly independent of self-generated whisker movements. The patchwork activity pattern largely disappeared during postnatal week 2, as even L4 neurons within the same barrel tended to fire asynchronously. This spontaneous L4 activity pattern has features suitable for thalamocortical (TC circuit refinement in the neonatal barrel cortex. : By two-photon calcium imaging of layer 4 neurons and thalamocortical axon terminals in neonatal mouse barrel cortex, Mizuno et al. find a patchwork-like spontaneous activity pattern corresponding to the barrel map, which may be important for thalamocortical circuit maturation. Keywords: activity-dependent development, spontaneous activity, synchronized activity, barrel cortex, thalamocortical axons, neonates, in vivo calcium imaging, awake, single-cell labeling, whisker monitoring

  8. A Comparative Analysis of Perinatal Development of Barrel Cortex in Rat, Mouse and Guinea Pig Using Acetylcholinesterase Histochemistry

    OpenAIRE

    ŞENDEMİR, Erdoğan

    2014-01-01

    The role of acetylcholinesterase (AChE) in the developing neocortex was reexamined by comparing its expression in rats, mice and guinea pigs, following the protocol for acetylcholinesterase histochemistry (described in Sendemir et al., 1996) in order to determine the suitability of the breeding colony at UludaÛ University for use as an animal model. A total of 103 pups as well as two adult animals of each species were used. In the rat pups, acetylcholinesterase-rich patches were d...

  9. Mitigating tin whisker risks theory and practice

    CERN Document Server

    Handwerker, Carol A; Bath, Jasbir

    2016-01-01

    Discusses the growth mechanisms of tin whiskers and the effective mitigation strategies necessary to reduce whisker growth risks. This book covers key tin whisker topics, ranging from fundamental science to practical mitigation strategies. The text begins with a review of the characteristic properties of local microstructures around whisker and hillock grains to identify why these particular grains and locations become predisposed to forming whiskers and hillocks. The book discusses the basic properties of tin-based alloy finishes and the effects of various alloying elements on whisker formation, with a focus on potential mechanisms for whisker suppression or enhancement for each element. Tin whisker risk mitigation strategies for each tier of the supply chain for high reliability electronic systems are also described.

  10. Metal Whiskers: A Discussion of Risks and Mitigation

    Science.gov (United States)

    2010-11-30

    efforts to investigate – Chromate conversion finishes DO NOT appear to stop whisker formation [4] S. Arnold, "Repressing the Growth of Tin Whiskers...November 30, 2010 Metal Whiskers 10 Examples of Metal Whiskers Zinc-Plated Steel Bus Rail with Yellow Chromate Conversion Finish Zinc whiskers grew...Metal Whiskers 11 Examples of Metal Whiskers Tin-Plated D-Sub Connector Shell Connector Advertised as “RoHS Compliant” November 30, 2010 Metal

  11. Developmental changes in electrophysiological properties and a transition from electrical to chemical coupling between excitatory layer 4 neurons in the rat barrel cortex

    Directory of Open Access Journals (Sweden)

    Fliza eValiullina

    2016-01-01

    Full Text Available During development, sensory systems switch from an immature to an adult mode of function along with the emergence of the active cortical states. Here, we used patch-clamp recordings from neocortical slices in vitro to characterize the developmental changes in the basic electrophysiological properties of excitatory L4 neurons and their connectivity before and after the developmental switch, which occurs in the rat barrel cortex in vivo at postnatal day P8. Prior to the switch, L4 neurons had lower resting membrane potentials, higher input resistance, lower membrane capacity, as well as action potentials (APs with smaller amplitudes, longer durations and higher AP thresholds compared to the neurons after the switch. A sustained firing pattern also emerged around the switch. Dual patch-clamp recordings from L4 neurons revealed that recurrent connections between L4 excitatory cells do not exist before and develop rapidly across the switch. In contrast, electrical coupling between these neurons waned around the switch. We suggest that maturation of electrophysiological features, particularly acquisition of a sustained firing pattern, and a transition from the immature electrical to mature chemical synaptic coupling between excitatory L4 neurons, contributes to the developmental switch in the cortical mode of function.

  12. Whiskers and fibers of hydroxyapatite; Whiskers e fibras de hidroxiapatita

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, G.B.C.; Motisuke, M.; Zavaglia, C.A.C., E-mail: guicardoso@fem.unicamp.b [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica. Dept. de Engenharia de Materiais; Arruda, A.C.F. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica. Dept. de Engenharia de Petroleo

    2009-07-01

    Hydroxyapatite is a bioactive ceramic, which acts in tissue engineering by attracting bone cells. Occasionally it can be used as a biocompatible reinforcement. The mechanical role of this biomaterial can be defined depending of some characteristics analyzed by scanning electron microscope and X ray power diffraction. It can be classified in whiskers and fibers; each one has their own properties, which were discussed in this work. For its use as reinforcement it is necessary matrix with specific characteristics. (author)

  13. SCT Barrel Assembly Complete

    CERN Multimedia

    L. Batchelor

    As reported in the April 2005 issue of the ATLAS eNews, the first of the four Semiconductor Tracker (SCT) barrels, complete with modules and services, arrived safely at CERN in January of 2005. In the months since January, the other three completed barrels arrived as well, and integration of the four barrels into the entire barrel assembly commenced at CERN, in the SR1 building on the ATLAS experimental site, in July. Assembly was completed on schedule in September, with the addition of the innermost layer to the 4-barrel assembly. Work is now underway to seal the barrel thermal enclosure. This is necessary in order to enclose the silicon tracker in a nitrogen atmosphere and provide it with faraday-cage protection, and is a delicate and complicated task: 352 silicon module powertapes, 352 readout-fibre bundles, and over 400 Detector Control System sensors must be carefully sealed into the thermal enclosure bulkhead. The team is currently verifying the integrity of the low mass cooling system, which must be d...

  14. The crystallographic growth directions of Sn whiskers

    International Nuclear Information System (INIS)

    Stein, J.; Welzel, U.; Leineweber, A.; Huegel, W.; Mittemeijer, E.J.

    2015-01-01

    The growth directions of 55 Sn whiskers, i.e. the crystallographic orientation parallel to the whisker-growth axes, were determined using (i) a focused ion beam microscope for the determination of the physical growth angles of the whiskers with respect to a specimen (reference) coordinate system and (ii) an electron backscatter detector in a scanning electron microscope for the determination of the crystallographic orientation of the whiskers. The Sn whiskers were found to grow preferentially along low-index directions of the β-Sn crystal structure. The experimental findings of this study (and most of the results presented in the literature as well) were explained by applying, in a modified way, the Hartman–Perdok concept of periodic bond chains, i.e. chains of strong bonds running uninterruptedly through the structure, to the Sn whisker-growth phenomenon

  15. Sn whiskers removed by energy photo flashing

    International Nuclear Information System (INIS)

    Jiang, N.; Yang, M.; Novak, J.; Igor, P.; Osterman, M.

    2012-01-01

    Highlights: ► Sn whiskers were sintered by intense light flashing (Photosintering). ► Photosintering can effectively eliminate Sn whiskers. ► Photosintering would not damage electronic devices. ► Photosintering is a very promising approach to improve Sn-based electronic surface termination. - Abstract: Sn whiskers have been known to be the major issue resulting in electronic circuit shorts. In this study, we present a novel energy photo flashing approach (photosintering) to shorten and eliminate Sn whiskers. It has been found that photosintering is very effective to modify and remove Sn whiskers; only a sub-millisecond duration photosintering can amazingly get rid of over 90 vol.% of Sn whiskers. Moreover, this photosintering approach has also been proved to cause no damages to electronic devices, suggesting it is a potentially promising way to improve Sn-based electronic surface termination.

  16. NASA Goddard Space Flight Center Tin Whisker (and Other Metal Whisker) Homepage

    Science.gov (United States)

    Brusse, Jay; Sampson, Mike; Leidecker, Henning; Kadesch, Jong

    2004-01-01

    This website provides information about tin whiskers and related research. The independent research performed during the past 50+ years is so vast that it is impractical to cover all aspects of tin whiskers in this one resource. Therefore, the absence of information in this website about a particular aspect of tin whiskers should NOT be construed as evidence of absence.

  17. TRT Barrel milestones passed

    CERN Multimedia

    Ogren, H

    2004-01-01

    The barrel TRT detector passed three significant milestones this spring. The Barrel Support Structure (BSS) was completed and moved to the SR-1 building on February 24th. On March 12th the first module passed the quality assurance testing in Building 154 and was transported to the assembly site in the SR-1 building for barrel assembly. Then on April 21st the final production module that had been scanned at Hampton University was shipped to CERN. TRT Barrel Module Production The production of the full complement of barrel modules (96 plus 9 total spares) is now complete. This has been a five-year effort by Duke University, Hampton University, and Indiana University. Actual construction of the modules in the United States was completed in the first part of 2004. The production crews at each of the sites in the United States have now completed their missions. They are shown in the following pictures. Duke University: Production crew with the final completed module. Indiana University: Module producti...

  18. Plasticity-Related Gene 1 Affects Mouse Barrel Cortex Function via Strengthening of Glutamatergic Thalamocortical Transmission

    OpenAIRE

    Unichenko, Petr; Kirischuk, Sergei; Yang, Jenq-Wei; Baumgart, Jan; Roskoden, Thomas; Schneider, Patrick; Sommer, Angela; Horta, Guilherme; Radyushkin, Konstantin; Nitsch, Robert; Vogt, Johannes; Luhmann, Heiko J.

    2016-01-01

    Plasticity-related gene-1 (PRG-1) is a brain-specific protein that modulates glutamatergic synaptic transmission. Here we investigated the functional role of PRG-1 in adolescent and adult mouse barrel cortex both in vitro and in vivo. Compared with wild-type (WT) animals, PRG-1-deficient (KO) mice showed specific behavioral deficits in tests assessing sensorimotor integration and whisker-based sensory discrimination as shown in the beam balance/walking test and sandpaper tactile discriminatio...

  19. Barrelled locally convex spaces

    CERN Document Server

    Pérez Carreras, P

    1987-01-01

    This book is a systematic treatment of barrelled spaces, and of structures in which barrelledness conditions are significant. It is a fairly self-contained study of the structural theory of those spaces, concentrating on the basic phenomena in the theory, and presenting a variety of functional-analytic techniques.Beginning with some basic and important results in different branches of Analysis, the volume deals with Baire spaces, presents a variety of techniques, and gives the necessary definitions, exploring conditions on discs to ensure that they are absorbed by the barrels of the sp

  20. Electric field stimulated growth of Zn whiskers

    Science.gov (United States)

    Niraula, D.; McCulloch, J.; Warrell, G. R.; Irving, R.; Karpov, V. G.; Shvydka, Diana

    2016-07-01

    We have investigated the impact of strong (˜104 V/cm) electric fields on the development of Zn whiskers. The original samples, with considerable whisker infestation were cut from Zn-coated steel floors and then exposed to electric fields stresses for 10-20 hours at room temperature. We used various electric field sources, from charges accumulated in samples irradiated by: (1) the electron beam of a scanning electron microscope (SEM), (2) the electron beam of a medical linear accelerator, and (3) the ion beam of a linear accelerator; we also used (4) the electric field produced by a Van der Graaf generator. In all cases, the exposed samples exhibited a considerable (tens of percent) increase in whiskers concentration compared to the control sample. The acceleration factor defined as the ratio of the measured whisker growth rate over that in zero field, was estimated to approach several hundred. The statistics of lengths of e-beam induced whiskers was found to follow the log-normal distribution known previously for metal whiskers. The observed accelerated whisker growth is attributed to electrostatic effects. These results offer promise for establishing whisker-related accelerated life testing protocols.

  1. Electric field stimulated growth of Zn whiskers

    Energy Technology Data Exchange (ETDEWEB)

    Niraula, D.; McCulloch, J.; Irving, R.; Karpov, V. G. [Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States); Warrell, G. R.; Shvydka, Diana, E-mail: diana.shvydka@utoledo.edu [Department of Radiation Oncology, University of Toledo Health Science Campus, Toledo, Ohio 43614 (United States)

    2016-07-15

    We have investigated the impact of strong (∼10{sup 4} V/cm) electric fields on the development of Zn whiskers. The original samples, with considerable whisker infestation were cut from Zn-coated steel floors and then exposed to electric fields stresses for 10-20 hours at room temperature. We used various electric field sources, from charges accumulated in samples irradiated by: (1) the electron beam of a scanning electron microscope (SEM), (2) the electron beam of a medical linear accelerator, and (3) the ion beam of a linear accelerator; we also used (4) the electric field produced by a Van der Graaf generator. In all cases, the exposed samples exhibited a considerable (tens of percent) increase in whiskers concentration compared to the control sample. The acceleration factor defined as the ratio of the measured whisker growth rate over that in zero field, was estimated to approach several hundred. The statistics of lengths of e-beam induced whiskers was found to follow the log-normal distribution known previously for metal whiskers. The observed accelerated whisker growth is attributed to electrostatic effects. These results offer promise for establishing whisker-related accelerated life testing protocols.

  2. Barrel Module0 Autopsy

    CERN Document Server

    Cobal, M; Nessi, Marzio; Blanch, O; Zamora, Y

    1999-01-01

    Using the information from the Cs calibration runs, many of the problems affecting the response of the barrel Module0 prototype have been spotted out. These can be bad fibre-tile couplings, light losses from fibres bundling, broken fibres, not transparent tiles etc. After a visual inspection, most of these problems have been repaired.

  3. A crystal barrel

    CERN Multimedia

    2007-01-01

    The production of crystals for the barrel of the CMS electromagnetic calorimeter has been completed. This is an important milestone for the experiment, which received the last of its 62,960 crystals on 9 March. The members of the team responsible for the crystal acceptance testing at CERN display the last crystal for the CMS electromagnetic calorimeter barrel. From left to right: Igor Tarasov, Etiennette Auffray and Hervé Cornet.One of the six machines specially developed to measure 67 different parameters on each crystal. Igor Tarasov is seen inserting the last batch of crystals into the machine. The last of the 62,960 CMS barrel crystals arrived at CERN on 9 March. Once removed from its polystyrene protection, this delicate crystal, like thousands of its predecessors, will be inserted into the last of the 36 supermodules of the barrel electromagnetic calorimeter in a few days' time. This marks the end of an important chapter in an almost 15-year-long journey by the CMS crystals team, some of whose member...

  4. Tapered whiskers are required for active tactile sensation.

    Science.gov (United States)

    Hires, Samuel Andrew; Pammer, Lorenz; Svoboda, Karel; Golomb, David

    2013-11-19

    Many mammals forage and burrow in dark constrained spaces. Touch through facial whiskers is important during these activities, but the close quarters makes whisker deployment challenging. The diverse shapes of facial whiskers reflect distinct ecological niches. Rodent whiskers are conical, often with a remarkably linear taper. Here we use theoretical and experimental methods to analyze interactions of mouse whiskers with objects. When pushed into objects, conical whiskers suddenly slip at a critical angle. In contrast, cylindrical whiskers do not slip for biologically plausible movements. Conical whiskers sweep across objects and textures in characteristic sequences of brief sticks and slips, which provide information about the tactile world. In contrast, cylindrical whiskers stick and remain stuck, even when sweeping across fine textures. Thus the conical whisker structure is adaptive for sensor mobility in constrained environments and in feature extraction during active haptic exploration of objects and surfaces. DOI: http://dx.doi.org/10.7554/eLife.01350.001.

  5. Microscopic Structure of Metal Whiskers

    Science.gov (United States)

    Borra, Vamsi; Georgiev, Daniel G.; Karpov, V. G.; Shvydka, Diana

    2018-05-01

    We present TEM images of the interior of metal whiskers (MWs) grown on electroplated Sn films. Along with earlier published information, our observations focus on a number of questions, such as, why MWs' diameters are in the micron range (significantly exceeding the typical nanosizes of nuclei in solids), why the diameters remain practically unchanged in the course of MW growth, what the nature of MW diameter stochasticity is, and what the origin of the well-known striation structure of MW side surfaces is. In an attempt to address such questions, we perform an in-depth study of MW structure at the nanoscale by detaching a MW from its original film, reducing its size to a thin slice by cutting its sides by a focused ion beam, and performing TEM on that structure. Also, we examine the root of the MW and Cu-Sn interface for the intermetallic compounds. Our TEM observations reveal a rich nontrivial morphology suggesting that MWs may consist of many side-by-side grown filaments. This structure appears to extend to the outside whisker surface and be the reason for the striation. In addition, we put forward a theory where nucleation of multiple thin metal needles results in micron-scale and larger MW diameters. This theory is developed in the average field approximation similar to the roughening transitions of metal surfaces. The theory also predicts MW nucleation barriers and other observed features.

  6. The PANDA Barrel DIRC

    Science.gov (United States)

    Schwiening, J.; Ali, A.; Belias, A.; Dzhygadlo, R.; Gerhardt, A.; Götzen, K.; Kalicy, G.; Krebs, M.; Lehmann, D.; Nerling, F.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwarz, C.; Traxler, M.; Böhm, M.; Eyrich, W.; Lehmann, A.; Pfaffinger, M.; Uhlig, F.; Düren, M.; Etzelmüller, E.; Föhl, K.; Hayrapetyan, A.; Kreutzfeld, K.; Merle, O.; Rieke, J.; Schmidt, M.; Wasem, T.; Achenbach, P.; Cardinali, M.; Hoek, M.; Lauth, W.; Schlimme, S.; Sfienti, C.; Thiel, M.

    2018-03-01

    The PANDA experiment at the international accelerator Facility for Antiproton and Ion Research in Europe (FAIR) near GSI, Darmstadt, Germany will address fundamental questions of hadron physics. Excellent Particle Identification (PID) over a large range of solid angles and particle momenta will be essential to meet the objectives of the rich physics program. Charged PID for the barrel region of the PANDA target spectrometer will be provided by a DIRC (Detection of Internally Reflected Cherenkov light) detector. The Barrel DIRC will cover the polar angle range of 22o-140o and cleanly separate charged pions from kaons for momenta between 0.5 GeV/c and 3.5 GeV/c with a separation power of at least 3 standard deviations. The design is based on the successful BABAR DIRC and the SuperB FDIRC R&D with several important improvements to optimize the performance for PANDA, such as a focusing lens system, fast timing, a compact fused silica prism as expansion region, and lifetime-enhanced Microchannel-Plate PMTs for photon detection. This article describes the technical design of the PANDA Barrel DIRC and the result of the design validation using a "vertical slice" prototype in hadronic particle beams at the CERN PS.

  7. Fast feedback in active sensing: touch-induced changes to whisker-object interaction.

    Directory of Open Access Journals (Sweden)

    Dudi Deutsch

    Full Text Available Whisking mediated touch is an active sense whereby whisker movements are modulated by sensory input and behavioral context. Here we studied the effects of touching an object on whisking in head-fixed rats. Simultaneous movements of whiskers C1, C2, and D1 were tracked bilaterally and their movements compared. During free-air whisking, whisker protractions were typically characterized by a single acceleration-deceleration event, whisking amplitude and velocity were correlated, and whisk duration correlated with neither amplitude nor velocity. Upon contact with an object, a second acceleration-deceleration event occurred in about 25% of whisk cycles, involving both contacting (C2 and non-contacting (C1, D1 whiskers ipsilateral to the object. In these cases, the rostral whisker (C2 remained in contact with the object throughout the double-peak phase, which effectively prolonged the duration of C2 contact. These "touch-induced pumps" (TIPs were detected, on average, 17.9 ms after contact. On a slower time scale, starting at the cycle following first touch, contralateral amplitude increased while ipsilateral amplitude decreased. Our results demonstrate that sensory-induced motor modulations occur at various timescales, and directly affect object palpation.

  8. Neurons within the trigeminal mesencephalic nucleus encode for the kinematic parameters of the whisker pad macrovibrissae.

    Science.gov (United States)

    Mameli, Ombretta; Caria, Marcello A; Biagi, Francesca; Zedda, Marco; Farina, Vittorio

    2017-05-01

    It has been recently shown in rats that spontaneous movements of whisker pad macrovibrissae elicited evoked responses in the trigeminal mesencephalic nucleus (Me5). In the present study, electrophysiological and neuroanatomical experiments were performed in anesthetized rats to evaluate whether, besides the whisker displacement per se, the Me5 neurons are also involved in encoding the kinematic properties of macrovibrissae movements, and also whether, as reported for the trigeminal ganglion, even within the Me5 nucleus exists a neuroanatomical representation of the whisker pad macrovibrissae. Extracellular electrical activity of single Me5 neurons was recorded before, during, and after mechanical deflection of the ipsilateral whisker pad macrovibrissae in different directions, and with different velocities and amplitudes. In several groups of animals, single or multiple injections of the tracer Dil were performed into the whisker pad of one side, in close proximity to the vibrissae follicles, in order to label the peripheral terminals of the Me5 neurons innervating the macrovibrissae (whisking-neurons), and therefore, the respective perikaria within the nucleus. Results showed that: (1) the whisker pad macrovibrissae were represented in the medial-caudal part of the Me5 nucleus by a single cluster of cells whose number seemed to match that of the macrovibrissae; (2) macrovibrissae mechanical deflection elicited significant responses in the Me5 whisking-neurons, which were related to the direction, amplitude, and frequency of the applied deflection. The specific functional role of Me5 neurons involved in encoding proprioceptive information arising from the macrovibrissae movements is discussed within the framework of the whole trigeminal nuclei activities. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  9. Chemical vapor deposition of tetraboron silicide whiskers

    International Nuclear Information System (INIS)

    Motozima, Seizi; Sugiyama, Kozoh; Takahashi, Yasutaka

    1975-01-01

    Growth conditions of B 4 Si whiskers were investigated at the temperature range of 1000 - 1100 0 C. Optimum composition of halides was determined as BCl 3 /SiCl 4 =2 - 0.5, and BCl 3 =1 - 6 vol%, SiCl 4 =1 - 7 vol%. Gold had an excellent impurity effect with optimum concentration of 20 - 50 μg/cm 2 on whisker growth, and gave wool like whiskers of 0.1 - 1 μ in thickness and 0.5 - 2 mm in length. B 4 Si whisker growth was explained in terms of a tip VLS mechanism, for a drop-like deposit of impurity was observed on each tip. (auth.)

  10. Inorganic-whisker-reinforced polymer composites synthesis, properties and applications

    CERN Document Server

    Sun, Qiuju

    2015-01-01

    Inorganic-Whisker-Reinforced Polymer Composites: Synthesis, Properties and Applications gives a comprehensive presentation of inorganic microcrystalline fibers, or whiskers, a polymer composite filler. It covers whisker synthesis, surface modification, applications for reinforcing polymer-matrix composites, and analysis of resulting filled polymer composites. It focuses on calcium carbonate whiskers as a primary case study, introducing surface treatment methods for calcium carbonate whiskers and factors that influence them. Along with calcium carbonate, the book discusses potassium titanate and aluminum borate whiskers, which also comprise the new generation of inorganic whiskers. According to research results, composites filled by inorganic whiskers show improved strength, wear-resistance, thermal conductivity, and antistatic properties. It explains the importance of modifying polymer materials for use with inorganic whiskers and describes preparation and evaluation methods of polymers filled with inorganic ...

  11. Cellulose whisker/epoxy resin nanocomposites.

    Science.gov (United States)

    Tang, Liming; Weder, Christoph

    2010-04-01

    New nanocomposites composed of cellulose nanofibers or "whiskers" and an epoxy resin were prepared. Cellulose whiskers with aspect ratios of approximately 10 and approximately 84 were isolated from cotton and sea animals called tunicates, respectively. Suspensions of these whiskers in dimethylformamide were combined with an oligomeric difunctional diglycidyl ether of bisphenol A with an epoxide equivalent weight of 185-192 and a diethyl toluenediamine-based curing agent. Thin films were produced by casting these mixtures and subsequent curing. The whisker content was systematically varied between 4 and 24% v/v. Electron microscopy studies suggest that the whiskers are evenly dispersed within the epoxy matrix. Dynamic mechanical thermoanalysis revealed that the glass transition temperature (T(g)) of the materials was not significantly influenced by the incorporation of the cellulose filler. Between room temperature and 150 degrees C, i.e., below T(g), the tensile storage moduli (E') of the nanocomposites increased modestly, for example from 1.6 GPa for the neat polymer to 4.9 and 3.6 GPa for nanocomposites comprising 16% v/v tunicate or cotton whiskers. The relative reinforcement was more significant at 185 degrees C (i.e., above T(g)), where E' was increased from approximately 16 MPa (neat polymer) to approximately 1.6 GPa (tunicate) or approximately 215 MPa (cotton). The mechanical properties of the new materials are well-described by the percolation model and are the result of the formation of a percolating whisker network in which stress transfer is facilitated by strong interactions between the whiskers.

  12. Piriform cortical glutamatergic and GABAergic neurons express coordinated plasticity for whisker-induced odor recall.

    Science.gov (United States)

    Liu, Yahui; Gao, Zilong; Chen, Changfeng; Wen, Bo; Huang, Li; Ge, Rongjing; Zhao, Shidi; Fan, Ruichen; Feng, Jing; Lu, Wei; Wang, Liping; Wang, Jin-Hui

    2017-11-10

    Neural plasticity occurs in learning and memory. Coordinated plasticity at glutamatergic and GABAergic neurons during memory formation remains elusive, which we investigate in a mouse model of associative learning by cellular imaging and electrophysiology. Paired odor and whisker stimulations lead to whisker-induced olfaction response. In mice that express this cross-modal memory, the neurons in the piriform cortex are recruited to encode newly acquired whisker signal alongside innate odor signal, and their response patterns to these associated signals are different. There are emerged synaptic innervations from barrel cortical neurons to piriform cortical neurons from these mice. These results indicate the recruitment of associative memory cells in the piriform cortex after associative memory. In terms of the structural and functional plasticity at these associative memory cells in the piriform cortex, glutamatergic neurons and synapses are upregulated, GABAergic neurons and synapses are downregulated as well as their mutual innervations are refined in the coordinated manner. Therefore, the associated activations of sensory cortices triggered by their input signals induce the formation of their mutual synapse innervations, the recruitment of associative memory cells and the coordinated plasticity between the GABAergic and glutamatergic neurons, which work for associative memory cells to encode cross-modal associated signals in their integration, associative storage and distinguishable retrieval.

  13. Sensory prediction on a whiskered robot: A tactile analogy to "optic flow"

    Directory of Open Access Journals (Sweden)

    Christopher L Schroeder

    2012-10-01

    Full Text Available When an animal moves an array of sensors (e.g., the hand, the eye through the environment, spatial and temporal gradients of sensory data are related by the velocity of the moving sensory array. In vision, the relationship between spatial and temporal brightness gradients is quantified in the optical flow equation. In the present work, we suggest an analog to optical flow for the rodent vibrissal (whisker array, in which the perceptual intensity that flows over the array is bending moment. Changes in bending moment are directly related to radial object distance, defined as the distance between the base of a whisker and the point of contact with the object. Using both simulations and a 1x5 array (row of artificial whiskers, we demonstrate that local object curvature can be estimated based on differences in radial distance across the array. We then develop two algorithms, both based on tactile flow, to predict the future contact points that will be obtained as the whisker array translates along the object. The translation of the robotic whisker array represents the rat's head velocity. The first algorithm uses a calculation of the local object slope, while the second uses a calculation of the local object curvature. Both algorithms successfully predict future contact points for simple surfaces. The algorithm based on curvature was found to more accurately predict future contact points as surfaces became more irregular. We quantify the inter-related effects of whisker spacing and the object’s spatial frequencies, and examine the issues that arise in the presence of real-world noise, friction, and slip.

  14. Weapons barrel life cycle determination

    Directory of Open Access Journals (Sweden)

    Nebojša Pene Hristov

    2013-10-01

    Full Text Available This article describes the dynamic processes within the gun barrel during the firing process in exploitation. It generally defines the basic principles of constructing tube elements, and shows the distortion of the basic geometry of the tube interior due to wear as well as the impact it causes during exploitation. The article also defines basic empirical models as well as a model based on fracture mechanics for the calculation of a use-life of the barrel, and other elements essential for the safe use of the barrel as the basic weapon element. Erosion causes are analysed in order to control and reduce wear and prolong the lifetime of the gun barrel. It gives directions for the reparation of barrels with wasted resources. In conclusion, the most influential elements of tube wear are given as well as possible modifications of existing systems, primarily propellant charges, with a purpose of prolonging lifetime of gun barrels. The guidelines for a proper determination of the lifetime based on the barrel condition assessment are given as well. INTRODUCTION The barrel as the basic element of each weapon is described as well as the processes occurring during the firing that have impulsive character and are accompanied by large amounts of energy. The basic elements of barrel and itheir constructive characteristics are descibed. The relation between Internal ballistics, ie calculation of the propellant gas pressure in the firing process, and structural elements defined by the barrel material resistance is shown. In general, this part of the study explains the methodology of the gun barrel structural elements calculation, ie. barrel geometry, taking into account the degrees of safety in accordance with Military Standards.   TUBE WEAR AND DEFORMATIONS The weapon barrel gradually wears out during exploitation due to which it no longer satisfies the set requirements. It is considered that the barrel has experienced a lifetime when it fails to fulfill the

  15. The oil barrel price

    International Nuclear Information System (INIS)

    Blondy, J.; Papon, P.

    2009-01-01

    This paper proposes an overview and a prospective glance on the oil barrel price. It indicates the relevant indicators: Brent quotation, euro/dollar parity, economic activity indicators, world oil consumption distribution, crude oil production, refining capacity. It briefly presents the involved stake holders: crude oil producers, oil refiners, refined product dealers, and the OPEC. It discusses the major retrospective trends: evolution in relationship with geopolitical events and energy policies, strong correlation between oil demand and economic growth, prevalence of OPEC, growing importance of national oil companies. An emerging trend is noticed: growing role of emerging countries on the crude market. Some prospective issues are discussed: duration and intensity of economic recession, separation between economic growth and energy consumption, pace and ambition level of policies of struggle against climate change, exploitable resources, and geopolitical hazards. Four evolution hypotheses are discussed

  16. Plasticity-Related Gene 1 Affects Mouse Barrel Cortex Function via Strengthening of Glutamatergic Thalamocortical Transmission.

    Science.gov (United States)

    Unichenko, Petr; Kirischuk, Sergei; Yang, Jenq-Wei; Baumgart, Jan; Roskoden, Thomas; Schneider, Patrick; Sommer, Angela; Horta, Guilherme; Radyushkin, Konstantin; Nitsch, Robert; Vogt, Johannes; Luhmann, Heiko J

    2016-07-01

    Plasticity-related gene-1 (PRG-1) is a brain-specific protein that modulates glutamatergic synaptic transmission. Here we investigated the functional role of PRG-1 in adolescent and adult mouse barrel cortex both in vitro and in vivo. Compared with wild-type (WT) animals, PRG-1-deficient (KO) mice showed specific behavioral deficits in tests assessing sensorimotor integration and whisker-based sensory discrimination as shown in the beam balance/walking test and sandpaper tactile discrimination test, respectively. At P25-31, spontaneous network activity in the barrel cortex in vivo was higher in KO mice compared with WT littermates, but not at P16-19. At P16-19, sensory evoked cortical responses in vivo elicited by single whisker stimulation were comparable in KO and WT mice. In contrast, at P25-31 evoked responses were smaller in amplitude and longer in duration in WT animals, whereas KO mice revealed no such developmental changes. In thalamocortical slices from KO mice, spontaneous activity was increased already at P16-19, and glutamatergic thalamocortical inputs to Layer 4 spiny stellate neurons were potentiated. We conclude that genetic ablation of PRG-1 modulates already at P16-19 spontaneous and evoked excitability of the barrel cortex, including enhancement of thalamocortical glutamatergic inputs to Layer 4, which distorts sensory processing in adulthood. © The Author 2016. Published by Oxford University Press.

  17. CREB Regulates Experience-Dependent Spine Formation and Enlargement in Mouse Barrel Cortex

    Directory of Open Access Journals (Sweden)

    Annabella Pignataro

    2015-01-01

    Full Text Available Experience modifies synaptic connectivity through processes that involve dendritic spine rearrangements in neuronal circuits. Although cAMP response element binding protein (CREB has a key function in spines changes, its role in activity-dependent rearrangements in brain regions of rodents interacting with the surrounding environment has received little attention so far. Here we studied the effects of vibrissae trimming, a widely used model of sensory deprivation-induced cortical plasticity, on processes associated with dendritic spine rearrangements in the barrel cortex of a transgenic mouse model of CREB downregulation (mCREB mice. We found that sensory deprivation through prolonged whisker trimming leads to an increased number of thin spines in the layer V of related barrel cortex (Contra in wild type but not mCREB mice. In the barrel field controlling spared whiskers (Ipsi, the same trimming protocol results in a CREB-dependent enlargement of dendritic spines. Last, we demonstrated that CREB regulates structural rearrangements of synapses that associate with dynamic changes of dendritic spines. Our findings suggest that CREB plays a key role in dendritic spine dynamics and synaptic circuits rearrangements that account for new brain connectivity in response to changes in the environment.

  18. The Dilator Naris Muscle as a Reporter of Facial Nerve Regeneration in a Rat Model

    NARCIS (Netherlands)

    Weinberg, J.S.; Kleiss, I.J.; Knox, C.J.; Heaton, J.T.; Hadlock, T.A.

    2016-01-01

    OBJECTIVE: Many investigators study facial nerve regeneration using the rat whisker pad model, although widely standardized outcomes measures of facial nerve regeneration in the rodent have not yet been developed. The intrinsic whisker pad "sling" muscles producing whisker protraction, situated at

  19. NASA GSFC Tin Whisker Homepage http://nepp.nasa.gov/whisker

    Science.gov (United States)

    Shaw, Harry

    2000-01-01

    The NASA GSFC Tin Whisker Homepage provides general information and GSFC Code 562 experimentation results regarding the well known phenomenon of tin whisker formation from pure tin plated substrates. The objective of this www site is to provide a central repository for information pertaining to this phenomenon and to provide status of the GSFC experiments to understand the behavior of tin whiskers in space environments. The Tin Whisker www site is produced by Code 562. This www site does not provide information pertaining to patented or proprietary information. All of the information contained in this www site is at the level of that produced by industry and university researchers and is published at international conferences.

  20. Core barrel inner tube lifter

    Energy Technology Data Exchange (ETDEWEB)

    Jeffers, J P

    1968-07-16

    A core drill with means for selectively lifting a core barrel inner tube consists of a lifting means connected to the core barrel inner tube assembly. It has a closable passage to permit drilling fluid normally to pass through it. The lifting means has a normally downward facing surface and a means to direct drilling fluid pressure against that surface so that on closure of the passage to fluid flow, the pressure of the drilling fluid is caused to act selectively on it. This causes the lifting means to rise and lift the core barrel. (7 claims)

  1. CMS Barrel Pixel Detector Overview

    CERN Document Server

    Kästli, H C; Erdmann, W; Gabathuler, K; Hörmann, C; Horisberger, Roland Paul; König, S; Kotlinski, D; Meier, B; Robmann, P; Rohe, T; Streuli, S

    2007-01-01

    The pixel detector is the innermost tracking device of the CMS experiment at the LHC. It is built from two independent sub devices, the pixel barrel and the end disks. The barrel consists of three concentric layers around the beam pipe with mean radii of 4.4, 7.3 and 10.2 cm. There are two end disks on each side of the interaction point at 34.5 cm and 46.5 cm. This article gives an overview of the pixel barrel detector, its mechanical support structure, electronics components, services and its expected performance.

  2. Biopolymer nanocomposite films reinforced with nanocellulose whiskers

    Science.gov (United States)

    Amit Saxena; Marcus Foston; Mohamad Kassaee; Thomas J. Elder; Arthur J. Ragauskas

    2011-01-01

    A xylan nanocomposite film with improved strength and barrier properties was prepared by a solution casting using nanocellulose whiskers as a reinforcing agent. The 13C cross-polarization magic angle spinning (CP/MAS) nuclear magnetic resonance (NMR) analysis of the spectral data obtained for the NCW/xylan nanocomposite films indicated the signal intensity originating...

  3. Core barrel plug

    International Nuclear Information System (INIS)

    Tolino, R.W.; Hopkins, R.J.; Congleton, R.L.; Popalis, C.H.

    1986-01-01

    A plug is described for preventing flow through a port in a core barrel of a pressurized water nuclear reactor which consists of: a substantially cylindrical body formed with a cylindrical portion and a flange and defining a tapered leading open end with the other end being closed by an end plug attached to the flange, the body defining a bore therein extending from the open end to the end plug with the bore having a smaller diameter near the open end than near the end plug, the cylindrical portion having a lip near the open end and being formed with longitudinal slots extending from the open end toward the flange and extending entirely through the thickness of the cylindrical portion, the cylindrical portion having a circumferential first groove on the outer surface thereof located near the forwardmost portion of the cylindrical portion but not in the section of the cylindrical portion that has the slots therein, and a plurality of circumferential second grooves on the outer surface thereof located in the section of the cylindrical portion that has the slots therein, the first and second grooves establishing a seal between the cylindrical portion and the inside surface of the port when the cylindrical portion is expanded, and the flange and the end plug having a passageway defined therein for introducing a fluid into the body; a metal ring disposed in each of the second grooves; a mandrel slidably disposed and captured in the body and capable of being moved toward the open end of the body when the fluid is introduced through the passageway, thereby causing the cylindrical portion to be expanded into contact with the inside surface of the port; and a locking mechanism disposed in the end plug for preventing inadvertent movement of the mandrel

  4. Synaptic molecular imaging in spared and deprived columns of mouse barrel cortex with array tomography.

    Science.gov (United States)

    Weiler, Nicholas C; Collman, Forrest; Vogelstein, Joshua T; Burns, Randal; Smith, Stephen J

    2014-01-01

    A major question in neuroscience is how diverse subsets of synaptic connections in neural circuits are affected by experience dependent plasticity to form the basis for behavioral learning and memory. Differences in protein expression patterns at individual synapses could constitute a key to understanding both synaptic diversity and the effects of plasticity at different synapse populations. Our approach to this question leverages the immunohistochemical multiplexing capability of array tomography (ATomo) and the columnar organization of mouse barrel cortex to create a dataset comprising high resolution volumetric images of spared and deprived cortical whisker barrels stained for over a dozen synaptic molecules each. These dataset has been made available through the Open Connectome Project for interactive online viewing, and may also be downloaded for offline analysis using web, Matlab, and other interfaces.

  5. Theoretical and experimental analysis of the toughening behavior of whisker reinforcement in ceramic matrix composites

    International Nuclear Information System (INIS)

    Becher, P.F.; Hsueh, C.H.; Angelini, P.; Tiegs, T.N.

    1988-01-01

    Analytical solutions are presented describing the experimentally verified toughening of whisker reinforced ceramics. Clear insights are provided into the interrelationships of whiskers, matrices, and interfaces in the case of strong interfaces with minimized whisker pullout

  6. Pressureless sintering of whisker-toughened ceramic composites

    Science.gov (United States)

    Tiegs, T.N.

    1993-05-04

    A pressureless sintering method is disclosed for use in the production of whisker-toughened ceramic composites wherein the sintered density of composites containing up to about 20 vol. % SiC whiskers is improved by reducing the average aspect ratio of the whiskers to from about 10 to about 20. Sintering aids further improve the density, permitting the production of composites containing 20 vol. % SiC with sintered densities of 94% or better of theoretical density by a pressureless sintering method.

  7. Innovation Incubator: Whisker Labs Technical Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Sparn, Bethany F. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Frank, Stephen M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Earle, Lieko [National Renewable Energy Lab. (NREL), Golden, CO (United States); Scheib, Jennifer G. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-08-01

    The Wells Fargo Innovation Incubator (IN2) is a program to foster and accelerate startup companies with commercial building energy-efficiency and demand management technologies. The program is funded by the Wells Fargo Foundation and co-administered by the National Renewable Energy Laboratory (NREL). Whisker Labs, an Oakland, California-based company, was one of four awardees in the first IN2 cohort and was invited to participate in the program because of its novel electrical power sensing technology for circuit breakers. The stick-on Whisker meters install directly on the front face of the circuit breakers in an electrical panel using adhesive, eliminating the need to open the panel and install current transducers (CTs) on the circuit wiring.

  8. Whiskers and Localized Corrosion on Copper in Repository Environment

    International Nuclear Information System (INIS)

    Hermansson, Hans-Peter; Gillen, Peter

    2004-03-01

    Previous studies have demonstrated that whiskers (thread/hair shaped structures) can form on copper in a sulphide containing environment. A remaining important question is whether the attack on the copper metal surface beneath a whisker is of a localized or of a general nature. This issue has not been clarified as whiskers are very fragile and have always detached and fallen off from the surface at some stage of handling. It has therefore been very difficult to link the growth root of the whisker to underlying structures in the metal surface. A study was therefore initiated to settle the important issue of the relation between whisker position and the type of underlying metal attack. The usage of a porous medium was originally planned to support the whiskers in order to keep them in place and by post examinations characterize the nature of the whisker roots and thus the type of attack on the metal. However, the early stages of the present experimental work clearly indicated that other ways of study were necessary. A photographic method for the registration and positioning of whisker growth was therefore developed. It proved to be a successful means to coordinate whisker position and to link it with the attack on the underlying metal. Shortage of sulphide in previous experiments caused a retarded growth rate of whiskers. Therefore, in present experiments the sulphide concentration was kept at a more constant level throughout an experiment and a hindered whisker growth did not limit the attack on underlying metal. Whiskers and substrates were observed with a video camera throughout an experiment and the phase composition was examined with Laser Raman Spectroscopy, LRS and the Raman video microscope. Post examinations were also performed using light optical microscopy. By combining the results from the optical methods it has been possible to distinguish two kinds of whisker roots (small/large diameter) with the underlying metal surface. It has also been demonstrated

  9. Functional diversity of supragranular GABAergic neurons in the barrel cortex

    Directory of Open Access Journals (Sweden)

    Luc J Gentet

    2012-08-01

    Full Text Available Although the neocortex forms a distributed system comprised of several functional areas, its vertical columnar organization is largely conserved across areas and species, suggesting the existence of a canonical neocortical microcircuit. In order to elucidate the principles governing the organization of such a cortical diagram, a detailed understanding of the dynamics binding different types of cortical neurons into a coherent algorithm is essential. Within this complex circuitry, GABAergic interneurons, while forming approximately only 15-20% of all cortical neurons, appear critical in maintaining a dynamic balance between excitation and inhibition. Despite their importance, cortical GABAergic neurons have not been extensively studied in vivo and their precise role in shaping the local microcircuit sensory response still remains to be determined. Their paucity, combined with their molecular, anatomical and physiological diversity, has made it difficult to even establish a consensual nomenclature.However, recent technological advances in microscopy and mouse genetics have fostered a renewed interest in neocortical interneurons by putting them within visible reach of experimenters. The anatomically well-defined whisker-to-barrel pathway of the rodent is particularly amenable to studies attempting to link cortical circuit dynamics to behavior. To each whisker corresponds a discrete cortical unit equivalent to a single column, specialized in the encoding and processing of the sensory information it receives. In this review, we will focus on the functional role that each subtype of supragranular GABAergic neuron embedded within such a single neocortical unit may play in shaping the dynamics of the local circuit during somatosensory integration.

  10. Unimodal primary sensory cortices are directly connected by long-range horizontal projections in the rat sensory cortex

    Directory of Open Access Journals (Sweden)

    Jimmy eStehberg

    2014-09-01

    Full Text Available Research based on functional imaging and neuronal recordings in the barrel cortex subdivision of primary somatosensory cortex (SI of the adult rat has revealed novel aspects of structure-function relationships in this cortex. Specifically, it has demonstrated that single whisker stimulation evokes subthreshold neuronal activity that spreads symmetrically within gray matter from the appropriate barrel area, crosses cytoarchitectural borders of SI and reaches deeply into other unimodal primary cortices such as primary auditory (AI and primary visual (VI. It was further demonstrated that this spread is supported by a spatially matching underlying diffuse network of border-crossing, long-range projections that could also reach deeply into AI and VI. Here we seek to determine whether such a network of border-crossing, long-range projections is unique to barrel cortex or characterizes also other primary, unimodal sensory cortices and therefore could directly connect them. Using anterograde (BDA and retrograde (CTb tract-tracing techniques, we demonstrate that such diffuse horizontal networks directly and mutually connect VI, AI and SI. These findings suggest that diffuse, border-crossing axonal projections connecting directly primary cortices are an important organizational motif common to all major primary sensory cortices in the rat. Potential implications of these findings for topics including cortical structure-function relationships, multisensory integration, functional imaging and cortical parcellation are discussed.

  11. ID Barrel installed in cryostat

    CERN Multimedia

    Apsimon, R.; Romaniouk, A.

    Wednesday 23rd August was a memorable day for the Inner Detector community as they witnessed the transport and installation of the central part of the inner detector (ID-barrel) into the ATLAS detector. Many members of the collaboration gathered to witness this moment at Point 1. After years of design, construction and commissioning, the outer two detectors (TRT and SCT) of the ID barrel were moved from the SR1 cleanroom to the ATLAS cavern. The barrel was moved across the car park from building 2175 to SX1. Although only a journey of about 100 metres, this required weeks of planning and some degree of luck as far as the weather was concerned. Accelerometers were fitted to the barrel to provide real-time monitoring and no values greater than 0.1 g were recorded, fully satisfying the transport specification for this extremely precise and fragile detector. Muriel, despite her fear of heights, bravely volunteered to keep a close eye on the detector. Swapping cranes to cross the entire parking lot, while Mur...

  12. Increases in the numerical density of GAT-1 positive puncta in the barrel cortex of adult mice after fear conditioning.

    Directory of Open Access Journals (Sweden)

    Ewa Siucinska

    Full Text Available Three days of fear conditioning that combines tactile stimulation of a row of facial vibrissae (conditioned stimulus, CS with a tail shock (unconditioned stimulus, UCS expands the representation of "trained" vibrissae, which can be demonstrated by labeling with 2-deoxyglucose in layer IV of the barrel cortex. We have also shown that functional reorganization of the primary somatosensory cortex (S1 increases GABAergic markers in the hollows of "trained" barrels of the adult mouse. This study investigated how whisker-shock conditioning (CS+UCS affected the expression of puncta of a high-affinity GABA plasma membrane transporter GAT-1 in the barrel cortex of mice 24 h after associative learning paradigm. We found that whisker-shock conditioning (CS+UCS led to increase expression of neuronal and astroglial GAT-1 puncta in the "trained" row compared to controls: Pseudoconditioned, CS-only, UCS-only and Naïve animals. These findings suggest that fear conditioning specifically induces activation of systems regulating cellular levels of the inhibitory neurotransmitter GABA.

  13. Work on a ATLAS tile calorimeter Barrel

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    The Tile Calorimeter is designed as one barrel and two extended barrel hadron parts. The calorimeter consists of a cylindrical structure with inner and outer radius of 2280 and 4230 mm respectively. The barrel part is 5640 mm in length along the beam axis, while each of the extended barrel cylinders is 2910 mm long. Each detector cylinder is built of 64 independent wedges along the azimuthal direction. Between the barrel and the extended barrels there is a gap of about 600 mm, which is needed for the Inner Detector and the Liquid Argon cables, electronics and services. The barrel covers the region -1.0barrels cover the region 0.8<|h|<1.7.

  14. Composition of Whiskers Grown on Copper in Repository Environment

    International Nuclear Information System (INIS)

    Hermansson, Hans-Peter; Tarkpea, Peeter; Holgersson, Stellan

    2001-11-01

    There is a hypothesis that a special family of local attack on copper based on growth of whiskers of sulfide, oxide/hydroxide and also carbonate/malachite could appear in the repository environment. It was earlier demonstrated that such whiskers could grow in a laboratory simulated repository environment, containing sulfide. A suggested composition of whiskers has earlier been forwarded but was not demonstrated. In the present work whiskers and their substrates were grown and characterized by investigations with a combination of SEM-EDS, XRD and LRS (Laser Raman Spectroscopy) techniques. SEM-EDS was used to determine the morphology and an elemental composition and distribution of whiskers and their substrate. A special effort was made to find out if the whisker growth is of a local or global character. The phase status could be determined locally and globally by combining XRD and LRS techniques on whiskers and substrates. Ideally, LRS gives a phase resolution down to a radius of 1 μm on the sample surface. This is of great value as it is of interest to study if there are phase differences in different parts of a whisker. Such information is important to understand the whisker growth mechanism. Cylindrical samples of pure copper were prepared and exposed to the selected de-aerated model groundwater containing, among other ions, chloride and sulfide. Exposure was performed in sealed glass flasks under de-aerated conditions. After exposure the copper sample was investigated on the surface, in cross section and on whiskers using the mentioned techniques. The results show that a black, easily detached layer of corrosion products is formed on the sample surface. The corrosion layer was subdivided into at least five parallel strata (probably more) of different composition. Numerous small pits and shallow pitting attacks with a larger radius were observed in the copper metal and the metal surface was in general very rough. A multitude of very easily detached whiskers or

  15. Bulk Thermoelectric Materials Reinforced with SiC Whiskers

    Science.gov (United States)

    Akao, Takahiro; Fujiwara, Yuya; Tarui, Yuki; Onda, Tetsuhiko; Chen, Zhong-Chun

    2014-06-01

    SiC whiskers have been incorporated into Zn4Sb3 compound as reinforcements to overcome its extremely brittle nature. The bulk samples were prepared by either hot-extrusion or hot-pressing techniques. The obtained products containing 1 vol.% to 5 vol.% SiC whiskers were confirmed to exhibit sound appearance, high density, and fine-grained microstructure. Mechanical properties such as the hardness and fracture resistance were improved by the addition of SiC whiskers, as a result of dispersion strengthening and microstructural refinement induced by a pinning effect. Furthermore, crack deflection and/or bridging/pullout mechanisms are invoked by the whiskers. Regarding the thermoelectric properties, the Seebeck coefficient and electrical resistivity values comparable to those of the pure compound are retained over the entire range of added whisker amount. However, the thermal conductivity becomes large with increasing amount of SiC whiskers because of the much higher conductivity of SiC relative to the Zn4Sb3 matrix. This results in a remarkable degradation of the dimensionless figure of merit in the samples with addition of SiC whiskers. Therefore, the optimum amount of SiC whiskers in the Zn4Sb3 matrix should be determined by balancing the mechanical properties and thermoelectric performance.

  16. Nanoreinforced biocompatible hydrogels from wood hemicelluloses and cellulose whiskers

    Science.gov (United States)

    Muzaffer Ahmet Karaaslan; Mandla A. Tshabalala; Daniel J. Yelle; Gisela Buschle-Diller

    2011-01-01

    Nanoreinforced hydrogels with a unique network structure were prepared from wood cellulose whiskers coated with chemically modified wood hemicelluloses. The hemicelluloses were modified with 2-hydroxyethylmethacrylate prior to adsorption onto the cellulose whiskers in aqueous medium. Synthesis of the hydrogels was accomplished by in situ radical polymerization of the...

  17. Quantifying the Effect of Stress on Sn Whisker Nucleation Kinetics

    Science.gov (United States)

    Chason, Eric; Vasquez, Justin; Pei, Fei; Jain, Nupur; Hitt, Andrew

    2018-01-01

    Although Sn whiskers have been studied extensively, there is still a need to understand the driving forces behind whisker nucleation and growth. Many studies point to the role of stress, but confirming this requires a quantitative comparison between controlled stress and the resulting whisker evolution. Recent experimental studies applied stress to a Sn layer via thermal cycling and simultaneously monitored the evolution of the temperature, stress and number of nuclei. In this work, we analyze these nucleation kinetics in terms of classical nucleation theory to relate the observed behavior to underlying mechanisms including a stress dependent activation energy and a temperature and stress-dependent whisker growth rate. Non-linear least squares fitting of the data taken at different temperatures and strain rates to the model shows that the results can be understood in terms of stress decreasing the barrier for whisker nucleation.

  18. The PANDA Barrel DIRC detector

    International Nuclear Information System (INIS)

    Hoek, M.; Dzhygadlo, R.; Gerhardt, A.; Götzen, K.; Hohler, R.; Kalicy, G.; Kumawat, H.; Lehmann, D.; Lewandowski, B.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwarz, C.; Schwiening, J.; Traxler, M.; Zühlsdorf, M.; Dodokhov, V. Kh.; Britting, A.; Eyrich, W.

    2014-01-01

    The PANDA experiment at the new Facility for Antiproton and Ion Research in Europe (FAIR) at GSI, Darmstadt, will study fundamental questions of hadron physics and QCD using high-intensity cooled antiproton beams with momenta between 1.5 and 15 GeV/c. Efficient Particle Identification for a wide momentum range and the full solid angle is required for reconstructing the various physics channels of the PANDA program. Hadronic Particle Identification in the barrel region of the detector will be provided by a DIRC counter. The design is based on the successful BABAR DIRC with important improvements, such as focusing optics and fast photon timing. Several of these improvements, including different radiator geometries and optics, were tested in particle beams at GSI and at CERN. The evolution of the conceptual design of the PANDA Barrel DIRC and the performance of complex prototypes in test beam campaigns will be discussed

  19. The PANDA Barrel DIRC detector

    Energy Technology Data Exchange (ETDEWEB)

    Hoek, M., E-mail: matthias.hoek@uni-mainz.de [Institut für Kernphysik, Johannes Gutenberg University Mainz, Mainz (Germany); Dzhygadlo, R.; Gerhardt, A.; Götzen, K.; Hohler, R.; Kalicy, G.; Kumawat, H.; Lehmann, D.; Lewandowski, B.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwarz, C.; Schwiening, J.; Traxler, M.; Zühlsdorf, M. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt (Germany); Dodokhov, V. Kh. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Britting, A.; Eyrich, W. [Friedrich Alexander-University of Erlangen-Nuremberg, Erlangen (Germany); and others

    2014-12-01

    The PANDA experiment at the new Facility for Antiproton and Ion Research in Europe (FAIR) at GSI, Darmstadt, will study fundamental questions of hadron physics and QCD using high-intensity cooled antiproton beams with momenta between 1.5 and 15 GeV/c. Efficient Particle Identification for a wide momentum range and the full solid angle is required for reconstructing the various physics channels of the PANDA program. Hadronic Particle Identification in the barrel region of the detector will be provided by a DIRC counter. The design is based on the successful BABAR DIRC with important improvements, such as focusing optics and fast photon timing. Several of these improvements, including different radiator geometries and optics, were tested in particle beams at GSI and at CERN. The evolution of the conceptual design of the PANDA Barrel DIRC and the performance of complex prototypes in test beam campaigns will be discussed.

  20. Completion of the TRT Barrel

    CERN Multimedia

    Gagnon, P

    On February 3, the US-TRT team proudly completed the installation of the 96th barrel TRT module on its support structure in the SR building at CERN. This happy event came after many years of R&D initiated in the nineties by the TA1 team at CERN, followed by the construction of the modules in three American institutes (Duke, Hampton and Indiana Universities) from 1996 to 2003. In total, the 96 barrel modules contain 52544 kapton straws, each 4 mm in diameter and strung with a 30 micron gold-plated tungsten wire. Each wire was manually inserted, a feat in itself! The inner layer modules contain 329 straws, the middle layer modules have 520 straws and the outer layer, 793 straws. Thirty- two modules of each type form a full layer. Their special geometry was designed such as to leave no dead region. On average, a particle will cross 36 straws. Kirill Egorov, Chuck Mahlon and John Callahan inserted the last module in the Barrel Support Structure. After completion in the US, all modules were transferred...

  1. Functional testing of the ATLAS SCT barrels

    International Nuclear Information System (INIS)

    Phillips, Peter W.

    2007-01-01

    The ATLAS SCT (semiconductor tracker) comprises 2112 barrel modules mounted on four concentric barrels of length 1.6m and up to 1m diameter, and 1976 endcap modules supported by a series of nine wheels at each end of the barrel region, giving a total silicon area of 60m 2 . The assembly of modules onto each of the four barrel structures has recently been completed. In addition to functional tests made during the assembly process, each completed barrel was operated in its entirety. In the case of the largest barrel, with an active silicon area of approximately 10m 2 , this corresponds to more than one million instrumented channels. This paper documents the electrical performance of the four individual SCT barrels. An overview of the readout chain is also given

  2. Orofacial Neuropathic Pain Leads to a Hyporesponsive Barrel Cortex with Enhanced Structural Synaptic Plasticity.

    Science.gov (United States)

    Thibault, Karine; Rivière, Sébastien; Lenkei, Zsolt; Férézou, Isabelle; Pezet, Sophie

    2016-01-01

    Chronic pain is a long-lasting debilitating condition that is particularly difficult to treat due to the lack of identified underlying mechanisms. Although several key contributing processes have been described at the level of the spinal cord, very few studies have investigated the supraspinal mechanisms underlying chronic pain. Using a combination of approaches (cortical intrinsic imaging, immunohistochemical and behavioural analysis), our study aimed to decipher the nature of functional and structural changes in a mouse model of orofacial neuropathic pain, focusing on cortical areas involved in various pain components. Our results show that chronic neuropathic orofacial pain is associated with decreased haemodynamic responsiveness to whisker stimulation in the barrel field cortex. This reduced functional activation is likely due to the increased basal neuronal activity (measured indirectly using cFos and phospho-ERK immunoreactivity) observed in several cortical areas, including the contralateral barrel field, motor and cingulate cortices. In the same animals, immunohistochemical analysis of markers for active pre- or postsynaptic elements (Piccolo and phospho-Cofilin, respectively) revealed an increased immunofluorescence in deep cortical layers of the contralateral barrel field, motor and cingulate cortices. These results suggest that long-lasting orofacial neuropathic pain is associated with exacerbated neuronal activity and synaptic plasticity at the cortical level.

  3. DELPHI Barrel Muon Chamber Module

    CERN Multimedia

    1989-01-01

    The module was used as part of the muon identification system on the barrel of the DELPHI detector at LEP, and was in active use from 1989 to 2000. The module consists of 7 individual muons chambers arranged in 2 layers. Chambers in the upper layer are staggered by half a chamber width with respect to the lower layer. Each individual chamber is a drift chamber consisting of an anode wire, 47 microns in diameter, and a wrapped copper delay line. Each chamber provided 3 signal for each muon passing through the chamber, from which a 3D space-point could be reconstructed.

  4. The OPAL muon barrel detector

    International Nuclear Information System (INIS)

    Akers, R.J.; Allison, J.; Ashton, P.; Bahan, G.A.; Baines, J.T.M.; Banks, J.N.; Barlow, R.J.; Barnett, S.; Beeston, C.; Chrin, J.T.M.; Clowes, S.G.; Davies, O.W.; Duerdoth, I.P.; Hinde, P.S.; Hughes-Jones, R.E.; Lafferty, G.D.; Loebinger, F.K.; Macbeth, A.A.; McGowan, R.F.; Moss, M.W.; Murphy, P.G.; Nijjhar, B.; O'Dowd, A.J.P.; Pawley, S.J.; Phillips, P.D.; Richards, G.E.; Skillman, A.; Stephens, K.; Tresillian, N.J.; Wood, N.C.; Wyatt, T.R.

    1995-01-01

    The barrel part of the OPAL muon detector consists of 110 drift chambers forming four layers outside the hadron absorber. Each chamber covers an area of 1.2 m by up to 10.4 m and has two cells with wires parallel to the beam and a drift distance of 297 mm. A detailed description of the design, construction, operation and performance of the sub-detector is given. The system has been operating successfully since the start of LEP in 1989. ((orig.))

  5. Bio-Inspired PVDF-Based, Mouse Whisker Mimicking, Tactile Sensor

    Directory of Open Access Journals (Sweden)

    Mohsin Islam Tiwana

    2016-10-01

    Full Text Available The design and fabrication of a Polyvinylidene fluoride (PVDF based, mouse (or rodent whisker mimicking, tactile sensor is presented. Unlike previous designs reported in the literature, this sensor mimics the mouse whisker not only mechanically, but it also makes macro movements just like a real mouse whisker in a natural environment. We have developed a mathematical model and performed finite element analysis using COMSOL, in order to optimise the whisker to have the same natural frequency as that of a biological whisker. Similarly, we have developed a control system that enables the whisker mimicking sensor to vibrate at variable frequencies and conducted practical experiments to validate the response of the sensor. The natural frequency of the whisker can be designed anywhere between 35 and 110 Hz, the same as a biological whisker, by choosing different materials and physical dimensions. The control system of this sensor enables the whisker to vibrate between 5 and 236 Hz.

  6. Research on SiC Whisker Prepared by H-PSO

    Directory of Open Access Journals (Sweden)

    WANG Yao

    2017-10-01

    Full Text Available SiC whiskers were prepared on the matrix of graphite by using high hydrogenous silicone oil(PSO as raw material. The effect of surface conditions of graphite and heating temperature on the growth of SiC whisker was mainly studied in this paper. The main factor which affects the nucleation and growth of SiC whisker is the heating temperature, with the heating temperature rising, the production of SiC whisker increases. The surface condition of graphite matrix also influences the growth of SiC whisker. With the nucleation points provided by graphite matrix defects increasing, the production of SiC whisker incleases and SiC whisker starts to overlap with each other. The formation process of SiC whisker includes two steps:nucleation and growth. SiC whisker nucleates at low temperature and grows at high temperature, which follows the VLS (vapor-liquid-solid growth mechanism.

  7. TRT and SCT barrels merge

    CERN Multimedia

    Wells, P S

    2006-01-01

    The SCT barrel was inserted in the TRT on 17 February, just missing Valentine's day. This was a change of emphasis for the two detectors. In the preceeding months there had been a lot of focus on testing their performance. The TRT had been observing cosmic rays through several sectors of the barrel, and all the modules on each of the four layers of the SCT had been characterised prior to integration. In parallel, the engineering teams, lead by Marco Olcese, Andrea Catinaccio, Eric Perrin, Neil Dixon, Iourii Gusakov, Gerard Barbier and Takashi Kohriki, had been preparing for this critical operation. Figure 1: Neil Dixon and Marco Olcese verifying the final alignment The two detectors had to be painstakingly aligned to be concentric to within a millimetre. The SCT was held on a temporary cantilever stand, and the TRT in the ID trolley had to inch over it. Finally the weight of the SCT was transferred to the rails on the inside of the TRT itself. The SCT services actually protruded a little outside the oute...

  8. Low-temperature strain gauges based on silicon whiskers

    Directory of Open Access Journals (Sweden)

    Druzhinin A. A.

    2008-08-01

    Full Text Available To create low-temperature strain gauges based on p-type silicon whiskers tensoresistive characteristics of these crystals in 4,2—300 K temperature range were studied. On the basis of p-type Si whiskers with different resistivity the strain gauges for different materials operating at cryogenic temperatures with extremely high gauge factor at 4,2 K were developed, as well as strain gauges operating at liquid helium temperatures in high magnetic fields.

  9. Physiological slowing and upregulation of inhibition in cortex are correlated with behavioral deficits in protein malnourished rats.

    Directory of Open Access Journals (Sweden)

    Rahul Chaudhary

    Full Text Available Protein malnutrition during early development has been correlated with cognitive and learning disabilities in children, but the neuronal deficits caused by long-term protein deficiency are not well understood. We exposed rats from gestation up to adulthood to a protein-deficient (PD diet, to emulate chronic protein malnutrition in humans. The offspring exhibited significantly impaired performance on the 'Gap-crossing' (GC task after reaching maturity, a behavior that has been shown to depend on normal functioning of the somatosensory cortex. The physiological state of the somatosensory cortex was examined to determine neuronal correlates of the deficits in behavior. Extracellular multi-unit recording from layer 4 (L4 neurons that receive direct thalamocortical inputs and layers 2/3 (L2/3 neurons that are dominated by intracortical connections in the whisker-barrel cortex of PD rats exhibited significantly low spontaneous activity and depressed responses to whisker stimulation. L4 neurons were more severely affected than L2/3 neurons. The response onset was significantly delayed in L4 cells. The peak response latency of L4 and L2/3 neurons was delayed significantly. In L2/3 and L4 of the barrel cortex there was a substantial increase in GAD65 (112% over controls and much smaller increase in NMDAR1 (12-20%, suggesting enhanced inhibition in the PD cortex. These results show that chronic protein deficiency negatively affects both thalamo-cortical and cortico-cortical transmission during somatosensory information processing. The findings support the interpretation that sustained protein deficiency interferes with features of cortical sensory processing that are likely to underlie the cognitive impairments reported in humans who have suffered from prolonged protein deficiency.

  10. Tin Whisker Growth and Mitigation with a Nanocrysytalline Nickel Coating

    Science.gov (United States)

    Janiuk, Szymon

    Tin whiskers are a problem in the electronics industry since the EU banned the use of lead in Pb-Sn solders as part of the Restriction of Hazardous Substances (RoHS). The biggest concern with Sn whiskers is their ability to short-circuit electronics. High reliability applications such as the aerospace, defense, healthcare, and automotive industries are at most risk. This project explores Sn whisker mitigation and prevention with the use of nanocrystalline nickel coating over Sn surfaces. Sn was plated onto a pure Cu substrate using electroplating. A high temperature and high humidity condition, at 85°C and 85% RH, was effective at growing whiskers. A nNi coating was plated over Sn/Cu coupons. After subjecting the nNi/ Sn/Cu samples through 85°C/85% RH testing conditions, no whiskers were observed penetrating the surface. These results make nNi a viable material to use as a coating to prevent the growth of Sn whiskers in electronic assemblies.

  11. Developmental switch in neurovascular coupling in the immature rodent barrel cortex.

    Directory of Open Access Journals (Sweden)

    Christoph M Zehendner

    Full Text Available Neurovascular coupling (NVC in the adult central nervous system (CNS is a mechanism that provides regions of the brain with more oxygen and glucose upon increased levels of neural activation. Hemodynamic changes that go along with neural activation evoke a blood oxygen level-dependent (BOLD signal in functional magnetic resonance imaging (fMRI that can be used to study brain activity non-invasively. A correct correlation of the BOLD signal to neural activity is pivotal to understand this signal in neuronal development, health and disease. However, the function of NVC during development is largely unknown. The rodent whisker-to-barrel cortex is an experimentally well established model to study neurovascular interdependences. Using extracellular multi-electrode recordings and laser-Doppler-flowmetry (LDF we show in the murine barrel cortex of postnatal day 7 (P7 and P30 mice in vivo that NVC undergoes a physiological shift during the first month of life. In the mature CNS it is well accepted that cortical sensory processing results in a rise in regional cerebral blood flow (rCBF. We show in P7 animals that rCBF decreases during prolonged multi-whisker stimulation and goes along with multi unit activity (MUA fatigue. In contrast at P30, MUA remains stable during repetitive stimulation and is associated with an increase in rCBF. Further we characterize in both age groups the responses in NVC to single sensory stimuli. We suggest that the observed shift in NVC is an important process in cortical development that may be of high relevance for the correct interpretation of brain activity e.g. in fMRI studies of the immature central nervous system (CNS.

  12. Core barrel motion calibration factor calculation

    International Nuclear Information System (INIS)

    Shahrokhi, F.; Robinson, J.C.

    1976-01-01

    Neutron transport theory calculations were performed to obtain a calibration factor for inferring core-barrel motion from spectral density data using excore ionization chambers in PWRs. The analysis of core-barrel movement was based on the postulate that the movement is a cantilevered type, with the preferred direction x-x'

  13. Hair Follicle Bulb as a Biodosimeter for Low-Level VX Vapor Exposure: Initial Studies Validating the Presence of Potential Protein Biomarkers of Exposure in the Sprague-Dawley Rat Whisker Follicle

    Science.gov (United States)

    2006-10-01

    amphetamine, methamphetamine, heroin , marijuana, and steroids), therapeutic drugs (e.g. ephedrine, benzodiazepines, and barbiturates), and inorganic heavy...Urine, Hair, Sweat and Saliva to Detect Drug Use. Drug and Alcohol Review 2004, 23, 213-217. 13. Kidwell, D.A.; Lee, E.H.; DeLauder, S.F. Evidence...Tomic, M. Effect of Soman Intoxication on the Organization of Rat Brain Ribosomes and the Translational Activity of mRNA in a Cell-free System

  14. Prototyping the PANDA Barrel DIRC

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, C., E-mail: C.Schwarz@gsi.de [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt (Germany); Kalicy, G.; Dzhygadlo, R.; Gerhardt, A.; Götzen, K.; Hohler, R.; Kumawat, H.; Lehmann, D.; Lewandowski, B.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwiening, J.; Traxler, M.; Zühlsdorf, M. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt (Germany); Dodokhov, V.Kh. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Britting, A.; Eyrich, W.; Lehmann, A. [Friedrich Alexander-University of Erlangen-Nuremberg, Erlangen (Germany); and others

    2014-12-01

    The design of the Barrel DIRC detector for the future PANDA experiment at FAIR contains several important improvements compared to the successful BABAR DIRC, such as focusing and fast timing. To test those improvements as well as other design options a prototype was build and successfully tested in 2012 with particle beams at CERN. The prototype comprises a radiator bar, focusing lens, mirror, and a prism shaped expansion volume made of synthetic fused silica. An array of micro-channel plate photomultiplier tubes measures the location and arrival time of the Cherenkov photons with sub-nanosecond resolution. The development of a fast reconstruction algorithm allowed to tune construction details of the detector setup with test beam data and Monte-Carlo simulations.

  15. The functional upregulation of piriform cortex is associated with cross-modal plasticity in loss of whisker tactile inputs.

    Directory of Open Access Journals (Sweden)

    Bing Ye

    Full Text Available Cross-modal plasticity is characterized as the hypersensitivity of remaining modalities after a sensory function is lost in rodents, which ensures their awareness to environmental changes. Cellular and molecular mechanisms underlying cross-modal sensory plasticity remain unclear. We aim to study the role of different types of neurons in cross-modal plasticity.In addition to behavioral tasks in mice, whole-cell recordings at the excitatory and inhibitory neurons, and their two-photon imaging, were conducted in piriform cortex. We produced a mouse model of cross-modal sensory plasticity that olfactory function was upregulated by trimming whiskers to deprive their sensory inputs. In the meantime of olfactory hypersensitivity, pyramidal neurons and excitatory synapses were functionally upregulated, as well as GABAergic cells and inhibitory synapses were downregulated in piriform cortex from the mice of cross-modal sensory plasticity, compared with controls. A crosswire connection between barrel cortex and piriform cortex was established in cross-modal plasticity.An upregulation of pyramidal neurons and a downregulation of GABAergic neurons strengthen the activities of neuronal networks in piriform cortex, which may be responsible for olfactory hypersensitivity after a loss of whisker tactile input. This finding provides the clues for developing therapeutic strategies to promote sensory recovery and substitution.

  16. Preparation of Polyaniline-Doped Fullerene Whiskers

    Directory of Open Access Journals (Sweden)

    Bingzhe Wang

    2013-01-01

    Full Text Available Fullerene C60 whiskers (FWs doped with polyaniline emeraldine base (PANI-EB were synthesized by mixing PANI-EB/N-methyl pyrrolidone (NMP colloid and FWs suspension based on the nature of the electron acceptor of C60 and electron donor of PANI-EB. Scanning electron microscopy (SEM, Fourier transform infrared (FT-IR, and ultraviolet-visible (UV-Vis spectra characterized the morphology and molecular structure of the FWs doped with PANI-EB. SEM observation showed that the smooth surface of FWs was changed to worm-like surface morphology after being doped with PANI-EB. The UV-Vis spectra suggested that charge-transfer (CT complex of C60 and PANI-EB was formed as PANI-EBδ+-C60δ-. PANI-EB-doped FWs might be useful as a new type of antibacterial and self-cleaning agent as well as multifunctional material to improve the human health and living environment.

  17. Liquid Argon Barrel Cryostat Arrived

    CERN Multimedia

    Pailler, P

    Last week the first of three cryostats for the ATLAS liquid argon calorimeter arrived at CERN. It had travelled for 46 days over several thousand kilometers from Japan to CERN. During three years it has been fabricated by Kawasaki Heavy Industries Ltd. at Harima, close to Kobe, under contract from Brookhaven National Laboratory (BNL) of the U.S.. This cryostat consists of two concentric cylinders made of aluminium: the outer vacuum vessel with a diameter of 5.5 m and a length of 7 m, and the inner cold vessel which will contain the electromagnetic barrel calorimeter immersed in liquid argon. The total weight will be 270 tons including the detectors and the liquid argon. The cryostat is now located in building 180 where it will be equipped with 64 feed-throughs which serve for the passage of 122,880 electrical lines which will carry the signals of the calorimeter. After integration of the calorimeter, the solenoidal magnet of ATLAS will be integrated in the vacuum vessel. A final cold test of the cryostat inc...

  18. Celebrating the Barrel Toroid commissioning

    CERN Multimedia

    Peter Jenni

    ATLAS invited Funding Agency representatives and Laboratory Heads directly related to the funding and construction of the Barrel Toroid for a small ceremony on 13th December 2006 at Point 1, in order to mark the successful first full excitation of the BT (see last eNews). On that date, which was during the December CERN Council week, several of the Funding Agency Heads or their representatives could be present, representing CEA France, INFN Italy, BMBF Germany, Spain, Sweden, Switzerland, Russia, JINR Dubna and CERN. Speeches were delivered by the ATLAS spokesperson Peter Jenni thanking the Funding Partners in the name of the Collaboration, by Magnet Project Leader Herman ten Kate tracing the BT construction history, and by the CERN Director-General Robert Aymar congratulating all those who have contributed to the successful project. Herman ten Kate addressing the delegates. The text of the introductory address by Peter Jenni is reproduced here. "It is a great pleasure for me to welcome you all here...

  19. Strengthening and toughening of poly(L-lactide) composites by surface modified MgO whiskers

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Wei [Biomaterial Research Laboratory, Department of Material Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Luo, Binghong, E-mail: tluobh@jnu.edu.cn [Biomaterial Research Laboratory, Department of Material Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Engineering Research Center of Artificial Organs and Materials, Ministry of Education, Guangzhou 510632 (China); Qin, Xiaopeng; Li, Cairong [Biomaterial Research Laboratory, Department of Material Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Liu, Mingxian; Ding, Shan [Biomaterial Research Laboratory, Department of Material Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Engineering Research Center of Artificial Organs and Materials, Ministry of Education, Guangzhou 510632 (China); Zhou, Changren, E-mail: tcrz9@jnu.edu.cn [Biomaterial Research Laboratory, Department of Material Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Engineering Research Center of Artificial Organs and Materials, Ministry of Education, Guangzhou 510632 (China)

    2015-03-30

    Highlights: • The grafted PLLA chain on the surface of g-MgO whisker was ruled out by FTIR spectroscopy and TG/DTG analyses. • The excellent dispersion of g-MgO whiskers and the strong interfacial adhesion of g-MgO whiskers/PLLA composite were proved by FSEM. • Comparing to MgO particles and MgO whiskers, fibrous-like g-MgO whiskers are the most effective reinforcing and toughening fillers for PLLA. - Abstract: To improve both the strength and toughness of poly(L-lactide) (PLLA), fibrous-like MgO whiskers with diameters of 0.15–1 μm and lengths of 15–110 μm were prepared, and subsequently surface modified with L-lactide to obtain grafted MgO whiskers (g-MgO whiskers). The structures and properties of MgO whiskers and g-MgO whiskers were studied. Then, a series of MgO whiskers/PLLA and g-MgO whiskers/PLLA composites were prepared by solution casting method, for comparison, MgO particles/PLLA composite was prepared too. The resulting composites were evaluated in terms of hydrophilicity, crystallinity, dispersion of whiskers, interfacial adhesion and mechanical performance by means of polarized optical microscopy (POM), contact angle measurement, field emission scanning electron microscope (FSEM), transmission electron microscopy (TEM) and tensile testing. The results revealed that the crystallization rate and hydrophilicity of PLLA were improved by the introduction of MgO whiskers and g-MgO whiskers. The g-MgO whiskers can disperse more uniformly in and show stronger interfacial adhesion with the matrix than MgO whiskers as a result of the surface modification. Due to the bridge effect of the whiskers and the excellent interfacial adhesion between g-MgO whiskers and PLLA, g-MgO whiskers/PLLA composites exhibited remarkably higher strength, modulus and toughness compared to the pristine PLLA, MgO particles/PLLA and MgO whiskers/PLLA composites.

  20. DC Characterisation of C60 Whiskers and Nanowhiskers

    DEFF Research Database (Denmark)

    Larsson, Michael; Kjelstrup-Hansen, Jakob; Lucyszyn, Stepan

    2007-01-01

    C60 whiskers exhibit increasing conductivity with decreasing diameter. At diameters of 1 mm and below, a single-crystal structure predominates, and enhanced electrical characteristics are expected; however, no supporting data exists in the literature. Here, results of four-point probe measurements......, indicating strong potential for use in organic electronic applications of the future. Repeated current cycling in air is observed to promote sample degradation, possibly due to progressive oxidation of the carbon structure. A micromachined four-point probe is also used to try to establish non...... on C60 whiskers and nanowhiskers with diameters in the range 650 nm to 1.3 mm are reported for the first time. Samples are attached to pre-patterned planar and raised electrodes using FIB-deposited tungsten. A low resistivity of 3 Wcm is measured in air, on a C60 whisker having a diameter of 650 nm...

  1. Extraction and characterization of whiskers from Panicum grass cellulose fibers

    International Nuclear Information System (INIS)

    Martins, Douglas F.; Vieira, Julia G.; Pasquini, Daniel

    2011-01-01

    In this work are presented studies of the extraction of cellulose whiskers from Panicum grass fibers (Panicum maximum) by acid hydrolysis performed with H 2 SO 4 11.22 M. The fibers used in the hydrolysis process were previously purified and the efficiency of the purification process was evaluated by determining the lignin content by Klason method, before and after purification. The hydrolysis was performed at 40 degree C for 30 minutes. The whiskers were characterized by x-ray diffraction (XRD) and thermogravimetric analysis (TGA). It was verified a reduction in the crystallinity index and also a reduction of the degradation temperature of the whiskers in relation to the purified grass Panicum fibers. (author)

  2. Nanocomposite polymer electrolyte based on whisker or microfibrils polyoxyethylene nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Alloin, Fannie, E-mail: fannie.alloin@lepmi.grenoble-inp.f [LEPMI, Laboratoire d' Electrochimie et de Physicochimie des Materiaux et des Interfaces, Grenoble-INP-UJF-CNRS, UMR 5631, BP 75, 38041 Grenoble Cedex 9 (France); D' Aprea, Alessandra [Laboratoire de Rheologie, Grenoble-INP-UJF, UMR 5520, BP 53, 38041 Grenoble Cedex 9 (France); LEPMI, Laboratoire d' Electrochimie et de Physicochimie des Materiaux et des Interfaces, Grenoble-INP-UJF-CNRS, UMR 5631, BP 75, 38041 Grenoble Cedex 9 (France); Ecole Internationale du Papier, de la communication imprimee et des Biomateriaux, PAGORA- Grenoble-INP, BP 65, 38402 Saint Martin d' Heres Cedex (France); Kissi, Nadia El [Laboratoire de Rheologie, Grenoble-INP-UJF, UMR 5520, BP 53, 38041 Grenoble Cedex 9 (France); Dufresne, Alain [Ecole Internationale du Papier, de la communication imprimee et des Biomateriaux, PAGORA- Grenoble-INP, BP 65, 38402 Saint Martin d' Heres Cedex (France); Bossard, Frederic [Laboratoire de Rheologie, Grenoble-INP-UJF, UMR 5520, BP 53, 38041 Grenoble Cedex 9 (France)

    2010-07-15

    Nanocomposite polymer electrolytes composed of high molecular weight poly(oxyethylene) PEO as a matrix, LiTFSI as lithium salt and ramie, cotton and sisal whiskers with high aspect ratio and sisal microfibrils (MF), as reinforcing phase were prepared by casting-evaporation. The morphology of the composite electrolytes was investigated by scanning electron microscopy and their thermal behavior (characteristic temperatures, degradation temperature) were investigated by thermogravimetric analysis and differential scanning calorimetry. Nanocomposite electrolytes based on PEO reinforced by whiskers and MF sisal exhibited very high mechanical performance with a storage modulus of 160 MPa at high temperature. A weak decrease of the ionic conductivity was observed with the incorporation of 6 wt% of whiskers. The addition of microfibrils involved a larger decrease of the conductivity. This difference may be associated to the more restricted PEO mobility due to the addition of entangled nanofibers.

  3. Plasma deposition of polymer composite films incorporating nanocellulose whiskers

    Science.gov (United States)

    Samyn, P.; Airoudj, A.; Laborie, M.-P.; Mathew, A. P.; Roucoules, V.

    2011-11-01

    In a trend for sustainable engineering and functionalization of surfaces, we explore the possibilities of gas phase processes to deposit nanocomposite films. From an analysis of pulsed plasma polymerization of maleic anhydride in the presence of nanocellulose whiskers, it seems that thin nanocomposite films can be deposited with various patterns. By specifically modifying plasma parameters such as total power, duty cycle, and monomer gas pressure, the nanocellulose whiskers are either incorporated into a buckled polymer film or single nanocellulose whiskers are deposited on top of a polymeric film. The density of the latter can be controlled by modifying the exact positioning of the substrate in the reactor. The resulting morphologies are evaluated by optical microscopy, AFM, contact angle measurements and ellipsometry.

  4. Understanding and Predicting Gun Barrel Erosion

    National Research Council Canada - National Science Library

    Johnston, Ian A

    2005-01-01

    The Australian Defence Force will soon have to contend with gun barrel erosion issues arising from the use of new low-vulnerability gun propellants, the acquisition of new ammunition and gun systems...

  5. Work on the ATLAS semiconductor tracker barrel

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    Precision work is performed on the semiconductor tracker barrel of the ATLAS experiment. All work on these delicate components must be performed in a clean room so that impurities in the air, such as dust, do not contaminate the detector. The semiconductor tracker will be mounted in the barrel close to the heart of the ATLAS experiment to detect the path of particles produced in proton-proton collisions.

  6. The TileCal Barrel Test Assembly

    CERN Multimedia

    Leitner, R

    On 30th October, the mechanics test assembly of the central barrel of the ATLAS tile hadronic calorimeter was completed in building 185. It started on 23rd June and is the second wheel for the Tilecal completely assembled this year. The ATLAS engineers and technicians are quick: instead of the 27 weeks initially foreseen for assembling the central barrel of the tile hadronic calorimeter (Tilecal) in building 185, they inserted the last of the 64 modules on 30th October after only 19 weeks. In part, this was due to the experience gained in the dry run assembly of the first extended barrel, produced in Spain, in spring this year (see Bulletin 23/2003); however, the central barrel is twice as long - and twice as heavy. With a length of 6.4 metres, an outer diameter of 8.5 metres and an inner diameter of 4.5 metres, the object weight is 1300 tonnes. The whole barrel cylinder is supported by the stainless steel support structure weighing only 27 tons. The barrel also has to have the right shape: over the whole 8...

  7. First SCT Barrel arrives at CERN

    CERN Multimedia

    Apsimon, R

    Mid-January saw the arrival at CERN of Barrel #3, the first of four SCT barrels. The barrels are formed as low-mass cylinders of carbon fibre skins on a honeycomb carbon core. They are manufactured in industry and then have all the final precision supports added and the final geometric metrology carried out at Geneva University. Barrel #3, complete with its 384 silicon detector modules, arrived by road from Oxford University in England where the modules were mounted using a purpose-built robot. The modules had been selected from the output of all four barrel module building clusters (in Japan, Scandinavia, USA and the UK). Since Barrel #3 will be exposed to high radiation levels within the tracker volume, these modules, representing over half a million readout channels, have been extensively tested at their operational temperature of around -25 degrees Celcius and at voltages of up to 500V. The dangers of shipping such a fragile component of ATLAS were apparent to all and considerable attention was focused...

  8. Synthesis and growth mechanisms of ZrC whiskers fabricated by a VLS process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dongju [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of). Nuclear Materials Development Division; Song, Sung Ho [Kongju National Univ., Chungnam (Korea, Republic of). Division of Advanced Materials Engineering

    2017-08-15

    The mechanisms of nano-sized ZrC whisker formation by a vapor-liquid-solid process (VLS) are investigated, which produces a very high purity, single crystal whisker. Rectangular ZrC whiskers with a cross-sectional diameter of 100-200 nm and lengths up to tens of microns are formed under the catalytic effect of nickel. The ZrC whiskers are characterized using scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. ZrC whiskers can be used as a potential reinforcing and strengthening phase for ceramic composites.

  9. Processing of Niobium-Lined M240 Machine Gun Barrels

    Science.gov (United States)

    2014-11-01

    Fig. 5 Finished niobium-lined M240 machine gun barrel with flash suppressor attached ..........11 Fig. 6 End of barrel 1 showing small amount of...the finished barrel is shown in Fig. 5. 11 Fig. 5 Finished niobium-lined M240 machine gun barrel with flash suppressor attached Firing tests

  10. Vortex Shedding in the Wake Induced by a Real Elephant Seal Whisker

    Science.gov (United States)

    Turk, Jodi; Omilion, Alexis; Zhang, Wei; Kim, Jeong-Jae; Kim, Jeong-Ju; Choi, Woo-Rak; Lee, Sang-Joon

    2017-11-01

    Biomimicry has been adopted to create innovative solutions in a vast range of applications. One such application is the design of seal-whisker-inspired flow sensors for autonomous underwater vehicles (AUVs). In dark, cramped, and unstable terrain AUVs are not able to maneuver using visual and sonar-based navigation. Hence, it is critical to use underwater flow sensors to accurately detect minute disturbances in the surroundings. Certain seal whiskers exhibit a unique undulating three-dimensional morphology that can reduce vortex induced vibrations (VIVs) if the major axis of the whisker cross-section is aligned to the inflow. This allows the seal to precisely track prey fish upstream using solely their whiskers. The current study aims to understand the effect of a real seal whisker's morphology on the vortex shedding behavior. Despite extensive studies of wake induced by scaled whisker-like models, the vortex shedding in the wake of a real seal whisker is not well understood. A series of experiments are conducted with a high-speed Particle Imaging Velocimetry (PIV) system in a water channel to examine the vortex shedding downstream from a smooth whisker and an undulating whisker at a Reynolds number of a few hundred. Results of the vortex shedding induced by real seal whiskers can provide insights on developing high-sensitivity underwater flow sensors for AUVs and other whisker-inspired structures.

  11. Enhancing Mechanical and Thermal Properties of Epoxy Nanocomposites via Alignment of Magnetized SiC Whiskers.

    Science.gov (United States)

    Townsend, James; Burtovyy, Ruslan; Aprelev, Pavel; Kornev, Konstantin G; Luzinov, Igor

    2017-07-12

    This research is focused on the fabrication and properties of epoxy nanocomposites containing magnetized SiC whiskers (MSiCWs). To this end, we report an original strategy for fabrication of magnetically active SiCWs by decorating the whiskers with magnetic (iron oxide) nanoparticles via polymer-polymer (poly(acrylic acid)/poly(2-vinyl pyridine)) complexation. The obtained whiskers demonstrated a substantial magnetic response in the polymerizing epoxy resin, with application of only a 20 mT (200 G) magnetic field. We also found that the whiskers chemically reacted with the epoxy resin, causing formation of an extended interphase near the boundary of the whiskers. The SiC whiskers oriented with the magnetic field demonstrated positive effects on the behavior of epoxy-based nanocomposites. Namely, the aligned MSiCWs enhanced the thermomechanical properties of the materials significantly above that of the neat epoxy and epoxy nanocomposite, with randomly oriented whiskers.

  12. Controlled growth of filamentary crystals and fabrication of single-crystal whisker probes

    International Nuclear Information System (INIS)

    Givargizov, E. I.

    2006-01-01

    The growth of filamentary crystals (whiskers) on a single-crystal substrate through the vapour-liquid-solid mechanism is described. The possibility of fabricating oriented systems of whiskers on the basis of this mechanism of crystal growth is noted. A phenomenon that is important for nanotechnology is noted: the existence of a critical diameter of whiskers, below which they are not formed. The phenomenon of radial periodic instability, which is characteristic of nanowhiskers, is described and the ways of its elimination are shown. The possibility of transforming whiskers into single-crystal tips and the growth of crystalline diamond particles at their apices are noted as important for practice. Possible applications of systems of whiskers and tips are described briefly. Particular attention is paid to the latest direction in whisker technology-fabrication of single-crystal whisker probes for atomic force microscopy

  13. Understanding and predicting metallic whisker growth and its effects on reliability : LDRD final report.

    Energy Technology Data Exchange (ETDEWEB)

    Michael, Joseph Richard; Grant, Richard P.; Rodriguez, Mark Andrew; Pillars, Jamin; Susan, Donald Francis; McKenzie, Bonnie Beth; Yelton, William Graham

    2012-01-01

    Tin (Sn) whiskers are conductive Sn filaments that grow from Sn-plated surfaces, such as surface finishes on electronic packages. The phenomenon of Sn whiskering has become a concern in recent years due to requirements for lead (Pb)-free soldering and surface finishes in commercial electronics. Pure Sn finishes are more prone to whisker growth than their Sn-Pb counterparts and high profile failures due to whisker formation (causing short circuits) in space applications have been documented. At Sandia, Sn whiskers are of interest due to increased use of Pb-free commercial off-the-shelf (COTS) parts and possible future requirements for Pb-free solders and surface finishes in high-reliability microelectronics. Lead-free solders and surface finishes are currently being used or considered for several Sandia applications. Despite the long history of Sn whisker research and the recently renewed interest in this topic, a comprehensive understanding of whisker growth remains elusive. This report describes recent research on characterization of Sn whiskers with the aim of understanding the underlying whisker growth mechanism(s). The report is divided into four sections and an Appendix. In Section 1, the Sn plating process is summarized. Specifically, the Sn plating parameters that were successful in producing samples with whiskers will be reviewed. In Section 2, the scanning electron microscopy (SEM) of Sn whiskers and time-lapse SEM studies of whisker growth will be discussed. This discussion includes the characterization of straight as well as kinked whiskers. In Section 3, a detailed discussion is given of SEM/EBSD (electron backscatter diffraction) techniques developed to determine the crystallography of Sn whiskers. In Section 4, these SEM/EBSD methods are employed to determine the crystallography of Sn whiskers, with a statistically significant number of whiskers analyzed. This is the largest study of Sn whisker crystallography ever reported. This section includes a

  14. Tin Whisker Formation — A Stress Relieve Phenomenon

    Science.gov (United States)

    Dittes, M.; Oberndorff, P.; Crema, P.; Su, P.

    2006-02-01

    With the move towards lead-free electronics also the solderable finish of electronic components' terminations are converted. While the typical finish was containing 5 % to 20 % lead (Pb) and thus was almost whisker free, lead (Pb)-free finishes such as pure tin or high tin alloys are rather prone to grow whisker. These whiskers are spontaneous protrusions that grow to a significant length of up to millimeters with a typical diameter in the range of few microns and are suspect to cause shorts in electronic assemblies. The latest details of the mechanisms are not yet understood. However it appears to be well established that the driving force for tin whisker growth is a compressive stress in the tin layer and that this stress is released by whisker formation. Besides the mechanism for whisker growth therefore the mechanism of the stress induction is of interest. The origin of that stress may have multiple sources. Among others the most important one is the volume increase within the tin layer due the formation of intermetallics at the interface to the base material. This applies to all copper based material. For base materials with a coefficient of thermal expansion (cte) significantly different from the tin finish another mechanism plays the dominant role. This is the induction of stress during thermal cycling due to the different expansion of the materials with every temperature change. Another mechanism for stress induction may be the oxidation of the finish, which also leads to a local volume increase. Based on the knowledge of stress induction various mitigation strategies can be deducted. Most common is the introduction of a diffusion barrier (e.g. Ni) in order to prevent the growth of the Cu-Sn intermetallics, the controlled growth of Cu-Sn intermetallics in order to prevent their irregularity or the introduction of a mechanical buffer material targeting at the minimisation of the cte mismatch between base and finish material. With respect to the stress

  15. [Biomimetic mineralization of rod-like cellulose nano-whiskers and spectrum analysis].

    Science.gov (United States)

    Qu, Ping; Wang, Xuan; Cui, Xiao-xia; Zhang, Li-ping

    2012-05-01

    Cellulose nano-whiskers/nano-hydroxyapatite composite was prepared with biomimetic mineralization using rod-like cellulose nano-whiskers as template. The cellulose nano-whiskers and cellulose nano-whiskers/nano-hydroxyapatite composite were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope-energy dispersive analysis of X-rays (SEM-EDXA). Variation and distribution of carbon, oxygen, calcium, and phosphorus in the composites were studied. The morphologies and growth mechanism of nano-hydroxyapatite were analyzed. The results showed that nano-hydroxyapatite was formed on the surface of cellulose nano-whiskers; the carbon-oxygen ratio of cellulose nano-whiskers and cellulose nano-whiskers/nano-hydroxyapatite composite was 1.81 and 1.54, respectively; the calcium-phosphorus ratio of the composite was 1.70. The nucleation of nano-hydroxyapatite was around the hydroxyl groups of cellulose nano-whiskers. It is suggested that there is coordination between the hydroxyl groups of cellulose nano-whiskers and calcium ions of nano-hydroxyapatite. The nano-hydroxyapatite can distribute in the matrix of cellulose nano-whiskers. From the atomic force microscope (AFM) images, we can see that the diameter of the spherical nano-hydroxyapatite particles was about 20 nm.

  16. The CMS Barrel Muon trigger upgrade

    International Nuclear Information System (INIS)

    Triossi, A.; Sphicas, P.; Bellato, M.; Montecassiano, F.; Ventura, S.; Ruiz, J.M. Cela; Bedoya, C. Fernandez; Tobar, A. Navarro; Fernandez, I. Redondo; Ferrero, D. Redondo; Sastre, J.; Ero, J.; Wulz, C.; Flouris, G.; Foudas, C.; Loukas, N.; Mallios, S.; Paradas, E.; Guiducci, L.; Masetti, G.

    2017-01-01

    The increase of luminosity expected by LHC during Phase1 will impose tighter constraints for rate reduction in order to maintain high efficiency in the CMS Level1 trigger system. The TwinMux system is the early layer of the muon barrel region that concentrates the information from different subdetectors: Drift Tubes, Resistive Plate Chambers and Outer Hadron Calorimeter. It arranges the slow optical trigger links from the detector chambers into faster links (10 Gbps) that are sent in multiple copies to the track finders. Results from collision runs, that confirm the satisfactory operation of the trigger system up to the output of the barrel track finder, will be shown.

  17. Application of Cu-polyimide flex circuit and Al-on-glass pitch adapter for the ATLAS SCT barrel hybrid

    CERN Document Server

    Unno, Y; Ikegami, Y; Iwata, Y; Kohriki, T; Kondo, T; Nakano, I; Ohsugi, T; Takashima, R; Tanaka, R; Terada, S; Ujiie, N

    2005-01-01

    We applied the surface build-up Cu-polyimide flex-circuit technology with laser vias to the ATLAS SCT barrel hybrid to be made in one piece from the connector to the electronics sections including cables. The hybrids, reinforced with carbon-carbon substrates, provide mechanical strength, thermal conductivity, low-radiation length, and stability in application-specific integrated circuit (ASIC) operation. By following the design rules, we experienced little trouble in breaking the traces. The pitch adapter between the sensor and the ASICs was made of aluminum traces on glass substrate. We identified that the generation of whiskers around the wire-bonding feet was correlated with the hardness of metallized aluminum. The appropriate hardness has been achieved by keeping the temperature of the glasses as low as room temperature during the metallization. The argon plasma cleaning procedure cleaned the contamination on the gold pads of the hybrids for successful wire bonding, although it was unsuccessful in the alu...

  18. Synthesis of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} whiskers and cross-whisker intrinsic Josephson junction

    Energy Technology Data Exchange (ETDEWEB)

    Hatano, T.; Takano, Y.; Arisawa, S.; Ishii, A.; Togano, K. [National Research Inst. for Metals, Tsukuba, Ibaraki (Japan); Fukuyo, A. [Science Univ. of Tokyo (Japan)

    2001-03-01

    A synthesis technique of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} single-crystal whiskers was studied. The whiskers were synthesized by heating glassy melt-quenched Bi-Sr-Ca-Cu-O (3:2:2:4 in cationic ratio) plates. The atmospheric condition of the whisker growth, especially oxygen partial pressure and gas flow, was investigated. It was found out that the whisker growth rate shows a maximum at P{sub O2}=2/3 bar. For the crystalline quality of the whiskers, the airtight condition was found to be useful as compared to the conventional oxygen stream condition. The crystalline quality, especially the straightness and morphology of the surface, could be improved by keeping the growing whiskers under the equilibrium P{sub Bi} condition. Over 20-mm-long whisker crystals have been successfully synthesized by choosing optimum oxygen partial pressure around the P{sub O2}=2/3 bar in the airtight condition. The growth condition and mechanism of the Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} whiskers were investigated by an in-situ high-temperature x-ray diffraction analysis and an in-situ high-temperature microscope observation. It was found that the whiskers grow in a partially melted state at a temperature of 10-40 degrees below the melting point. The result obtained demonstrates that Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} whiskers grow at their bottom by the conventional liquid-phase growth mechanism, as was proposed by Matsubara et al. (author)

  19. Synthesis of Bi2Sr2CaCu2O8+δ whiskers and cross-whisker intrinsic Josephson junction

    International Nuclear Information System (INIS)

    Hatano, T.; Takano, Y.; Arisawa, S.; Ishii, A.; Togano, K.; Fukuyo, A.

    2001-01-01

    A synthesis technique of Bi 2 Sr 2 CaCu 2 O 8+δ single-crystal whiskers was studied. The whiskers were synthesized by heating glassy melt-quenched Bi-Sr-Ca-Cu-O (3:2:2:4 in cationic ratio) plates. The atmospheric condition of the whisker growth, especially oxygen partial pressure and gas flow, was investigated. It was found out that the whisker growth rate shows a maximum at P O2 =2/3 bar. For the crystalline quality of the whiskers, the airtight condition was found to be useful as compared to the conventional oxygen stream condition. The crystalline quality, especially the straightness and morphology of the surface, could be improved by keeping the growing whiskers under the equilibrium P Bi condition. Over 20-mm-long whisker crystals have been successfully synthesized by choosing optimum oxygen partial pressure around the P O2 =2/3 bar in the airtight condition. The growth condition and mechanism of the Bi 2 Sr 2 CaCu 2 O 8+δ whiskers were investigated by an in-situ high-temperature x-ray diffraction analysis and an in-situ high-temperature microscope observation. It was found that the whiskers grow in a partially melted state at a temperature of 10-40 degrees below the melting point. The result obtained demonstrates that Bi 2 Sr 2 CaCu 2 O 8+δ whiskers grow at their bottom by the conventional liquid-phase growth mechanism, as was proposed by Matsubara et al. (author)

  20. The development of SiC whisker fabrication technology for nuclear applications

    International Nuclear Information System (INIS)

    Kang, Thae Khapp; Kuk, Il Hiun; Kim, Chang Kyu; Lee, Jae Chun; Lee, Ho Jin; Park, Soon Dong; Im, Gyeong Soo

    1991-02-01

    Some important experiments for whisker growth reactions, fabrication processes, and experiments for fabricarion of whisker reinforced composites have been performed. In order to investigate growth reaction of SiC whiskers, a conventional carbothermic reaction was tested. Based on the results of carbothermic process, a new process called silicothermic reaction was planned and some basic experiments were performed. Reaction characteristics of silicon monoxide, core material for SiC whisker growth in both of the reactions were investigated for basic data. Additionally, a hydrofluoric acid leaching process was tested for developing SiC whisker recovery process, and powder metallurgy process and melt sqeeze process were tried to develop aluminum-SiC whisker composites. (Author)

  1. Whisker-Like Formations in Sn-3.0Ag-Pb Alloys

    Directory of Open Access Journals (Sweden)

    Koncz-Horváth D.

    2017-06-01

    Full Text Available In this study, different types of whisker-like formations of Sn-3.0Ag based alloy were presented. In the experimental process the amount of Pb element was changed between 1000 and 2000 ppm, and the furnace atmosphere and cooling rate were also modified. The novelty of this work was that whisker-like formations in macro scale size were experienced after an exothermic reaction. The whiskers of larger sizes than general provided opportunities to investigate the microstructure and the concentration nearby the whiskers. In addition, the whisker-like formations from Sn-Ag based bulk material did not only consist of pure tin but tin and silver phases. The whisker-like growth appeared in several forms including hillock, spire and nodule shaped formations in accordance with parameters. It was observed that the compound phases were clustered in many cases mainly at hillocks.

  2. Fabrication of α-chitin whisker-reinforced poly(vinyl alcohol) nanocomposite nanofibres by electrospinning

    International Nuclear Information System (INIS)

    Junkasem, Jirawut; Rujiravanit, Ratana; Supaphol, Pitt

    2006-01-01

    The present contribution reports, for the first time, the successful fabrication of α-chitin whisker-reinforced poly(vinyl alcohol) (PVA) nanocomposite nanofibres by electrospinning. The α-chitin whiskers were prepared from α-chitin flakes from shrimp shells by acid hydrolysis. The as-prepared chitin whiskers exhibited lengths in the range 231-969 nm and widths in the range 12-65 nm, with the average length and width being about 549 and 31 nm, respectively. Successful incorporation of the chitin whiskers within the as-spun PVA/chitin whisker nanocomposite nanofibres was verified by infrared spectroscopic and thermogravimetric methods. The incorporation of chitin whiskers within the as-spun nanocomposite fibre mats increased the Young's modulus by about 4-8 times over that of the neat as-spun PVA fibre mat

  3. CMS : the first barrel ring completed !

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    On 14 November, the CMS collaboration and the German firm DWE celebrated the successful construction of the detector's first yoke barrel ring. To mark the occasion, those in charge of the construction at CERN and DWE posed for the camera in the middle of the giant component.

  4. Iron Blocks of CMS Magnet Barrel Yoke.

    CERN Multimedia

    2000-01-01

    On the occasion of presenting the CMS Award 2000 to Deggendorfer Werft und Eisenbau GmbH the delivered blocks were inspected at CERN Point 5. From left to right: H. Gerwig (CERN, CMS Magnet Barrel Yoke Coordinator), G. Waurick (CERN), F. Leher (DWE, Project Engineer) and W. Schuster (DWE, Project Manager).

  5. ATLAS semiconductor tracker installed into its barrel

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    The ATLAS silicon tracker is installed in the silicon tracker barrel. Absolute precision was required in this operation to ensure that the tracker was inserted without damage through minimal clearance. The installation was performed in a clean room on the CERN site so that no impurities in the air would contaminate the tracker's systems.

  6. Building CMS Pixel Barrel Detectur Modules

    CERN Document Server

    König, S; Horisberger, R.; Meier, B.; Rohe, T.; Streuli, S.; Weber, R.; Kastli, H.Chr.; Erdmann, W.

    2007-01-01

    For the barrel part of the CMS pixel tracker about 800 silicon pixel detector modules are required. The modules are bump bonded, assembled and tested at the Paul Scherrer Institute. This article describes the experience acquired during the assembly of the first ~200 modules.

  7. Celebration for the ATLAS Barrel Toroid magnet

    CERN Multimedia

    2007-01-01

    Representatives from Funding Agencies and Barrel Toroid Magnet Laboratories during the ceremony. From left to right: Jean Zinn-Justin (Head of DAPNIA/CEA/Saclay), CERN Director-General Robert Aymar, and Roberto Petronzio (President INFN).Allan Clark (DPNC University Geneva) and Enrique Fernandez (IFAE Barcelona) were among the guests visiting the ATLAS cavern. The barrel toroid is visible in the background. A celebration took place at Point 1 on 13 December to toast the recent powering-up of the ATLAS barrel toroid magnet to full field (Bulletin No. 47-48/06). About 70 guests were invited to attend, mainly composed of representatives from funding partners and key members of the laboratory management teams of the barrel toroid magnet, representing CEA France, INFN Italy, BMBF Germany, Spain, Sweden, Switzerland, Russia, JINR Dubna and CERN. An introductory speech by ATLAS spokesperson Peter Jenni the scene for evening. This was followed by the ATLAS magnet system project leader Herman Ten Kate's account of the...

  8. Last Few Metres for the Barrel Calorimeter

    CERN Multimedia

    Nyman, T.

    On Friday 4th November, the ATLAS Barrel Calorimeter was moved from its assembly point at the side of the ATLAS cavern to the centre of the toroidal magnet system. The detector was finally aligned, to the precision of within a millimetre, on Wednesday 9th November. The ATLAS installation team, led by Tommi Nyman, after having positioned the Barrel Calorimeter in its final location in the ATLAS experimental cavern UX15. The Barrel Calorimeter which will absorb and measure the energy of photons, electrons and hadrons at the core of the ATLAS detector is 8.6 meters in diameter, 6.8 meters long, and weighs over 1600 Tonnes. It consists of two concentric cylindrical detector elements. The innermost comprises aluminium pressure vessels containing the liquid argon electromagnetic calorimeter and the solenoid magnet. The outermost is an assembly of 64 hadron tile calorimeter sectors. Assembled 18 meters away from its final position, the Barrel Calorimeter was relocated with the help of a railway, which allows ...

  9. ATLAS Barrel Toroid magnet reached nominal field

    CERN Multimedia

    2006-01-01

     On 9 November the barrel toroid magnet reached its nominal field of 4 teslas, with an electrical current of 21 000 amperes (21 kA) passing through the eight superconducting coils as shown on this graph

  10. Contributions of Stress and Oxidation on the Formation of Whiskers in Pb-free Solders

    Science.gov (United States)

    2016-01-29

    nucleation of whiskers and the confirmation of the effect of oxygen content in the formation of whiskers. Different levels of elastic stress were...substrate P Load RH Relative humidity max Stress at the top surface of the film SE Secondary Electrons SEM Scanning Electron Microscopy SRNL...demonstration of effects of stress state in the nucleation of whiskers and the confirmation of the effect of oxygen content in the formation of

  11. Surface modification of magnesium hydroxide sulfate hydrate whiskers using a silane coupling agent by dry process

    International Nuclear Information System (INIS)

    Zhu, Donghai; Nai, Xueying; Lan, Shengjie; Bian, Shaoju; Liu, Xin; Li, Wu

    2016-01-01

    Highlights: • Dry process was adopted to modify the surface of MHSH whiskers using silane. • Si−O−Mg bonds were formed directly by the reaction between Si−OC 2 H 5 and −OH of MHSH. • Dispersibility and compatibility of modified whiskers greatly improved in organic phase. • Thermal stability of whiskers was enhanced after modified. - Abstract: In order to improve the compatibility of magnesium hydroxide sulfate hydrate (MHSH) whiskers with polymers, the surface of MHSH whiskers was modified using vinyltriethoxysilane (VTES) by dry process. The possible mechanism of the surface modification and the interfacial interactions between MHSH whiskers and VTES, as well as the effect of surface modification, were studied. Scanning electronic microscopy (SEM), transmission electron microscopy (TEM) and X-ray powder diffraction (XRD) analyses showed that the agglomerations were effectively separated and a thin layer was formed on the surface of the whiskers after modification. Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) analyses showed that the VTES molecules were bound to the surface of MHSH whiskers after modification. Chemical bonds (Si−O−Mg) were formed by the reaction between Si−OC 2 H 5 or Si−OH and the hydroxyl group of MHSH whiskers. The effect of surface modification was evaluated by sedimentation tests, contact angle measurements and thermogravimetric analysis (TGA). The results showed that the surface of MHSH whiskers was transformed from hydrophilic to hydrophobic, and the dispersibility and the compatibility of MHSH whiskers were significantly improved in the organic phase. Additionally, the thermal stability of the VTES-modified MHSH whiskers was improved significantly.

  12. An Empirical Model for Estimating the Probability of Electrical Short Circuits from Tin Whiskers. Part 2

    Science.gov (United States)

    Courey, Karim; Wright, Clara; Asfour, Shihab; Onar, Arzu; Bayliss, Jon; Ludwig, Larry

    2009-01-01

    In this experiment, an empirical model to quantify the probability of occurrence of an electrical short circuit from tin whiskers as a function of voltage was developed. This empirical model can be used to improve existing risk simulation models. FIB and TEM images of a tin whisker confirm the rare polycrystalline structure on one of the three whiskers studied. FIB cross-section of the card guides verified that the tin finish was bright tin.

  13. Silicon carbide whisker reinforced composites and method for making same

    Science.gov (United States)

    Wei, G.C.

    1984-02-09

    The present invention is directed to the fabrication of ceramic composites which possess improved mechanical properties, especially increased fracture toughness. In the formation of these ceramic composites, the single-crystal SiC whiskers are mixed with fine ceramic powders of a ceramic material such as Al/sub 2/O/sub 3/, mullite, or B/sub 4/C. The mixtures which contain a homogeneous dispersion of the SiC whiskers are hot pressed at pressures in a range of about 28 to 70 MPa and temperatures in the range of about 1600 to 1950/sup 0/C with pressing times varying from about 0.75 to 2.5 hours. The resulting ceramic composites show an increase in fracture toughness of up to about 9 MPa.m/sup 1/2/ which represents as much as a two-fold increase over that of the matrix material.

  14. Extraction and characterization of cellulose nano whiskers from balsa wood

    International Nuclear Information System (INIS)

    Morelli, Carolina L.; Bretas, Rosario E.S.; Marconcini, Jose M.; Pereira, Fabiano V.; Branciforti, Marcia C.

    2011-01-01

    In this study cellulose nano whiskers were obtained from balsa wood. For this purpose, fibers of balsa wood were subjected to hydrolysis reactions for lignin and hemi cellulose digestion and acquisition of nano-scale cellulose. Cellulose nano crystals obtained had medium length and thickness of 176 nm and 7 nm respectively. Infrared spectroscopy and x-ray diffraction showed that the process used for extracting nano whiskers could digest nearly all the lignin and hemi cellulose from the balsa fiber and still preserve the aspect ratio and crystallinity, satisfactory enough for future application in polymer nano composites. Thermogravimetry showed that the onset temperature of thermal degradation of cellulose nano crystals (226 degree C) was higher than the temperature of the balsa fiber (215 degree C), allowing its use in molding processes with many polymers from the molten state.(author)

  15. Crystalline instability of Bi-2212 superconducting whiskers near room temperature

    International Nuclear Information System (INIS)

    Cagliero, Stefano; Khan, Mohammad Mizanur Rahman; Agostino, Angelo; Truccato, Marco; Orsini, Francesco; Marinone, Massimo; Poletti, Giulio; Lascialfari, Alessandro

    2009-01-01

    We report new evidences for the thermodynamic instability of whisker crystals in the Bi-Sr-Ca-Cu-O (BSCCO) system. Annealing treatments at 90 C have been performed on two sets of samples, which were monitored by means of X-rays diffraction (XRD) and atomic force microscopy (AFM) measurements, respectively. Two main crystalline domains of Bi 2 Sr 2 CuCa 2 O 8+x (Bi-2212) were identified in the samples by the XRD data, which underwent an evident crystalline segregation after about 60 hours. Very fast dynamics of the surface modifications was also described by the AFM monitoring. Two typologies of surface structures formed after about 3 annealing hours: continuous arrays of dome shaped bodies were observed along the edges of the whiskers, while in the central regions a dense texture of flat bodies was found. These modifications are described in terms of the formation of simple oxide clusters involving a degradation of the internal layers. (orig.)

  16. Peripheral optogenetic stimulation induces whisker movement and sensory perception in head-fixed mice.

    Science.gov (United States)

    Park, Sunmee; Bandi, Akhil; Lee, Christian R; Margolis, David J

    2016-06-08

    We discovered that optical stimulation of the mystacial pad in Emx1-Cre;Ai27D transgenic mice induces whisker movements due to activation of ChR2 expressed in muscles controlling retraction and protraction. Using high-speed videography in anesthetized mice, we characterize the amplitude of whisker protractions evoked by varying the intensity, duration, and frequency of optogenetic stimulation. Recordings from primary somatosensory cortex (S1) in anesthetized mice indicated that optogenetic whisker pad stimulation evokes robust yet longer latency responses than mechanical whisker stimulation. In head-fixed mice trained to report optogenetic whisker pad stimulation, psychometric curves showed similar dependence on stimulus duration as evoked whisker movements and S1 activity. Furthermore, optogenetic stimulation of S1 in expert mice was sufficient to substitute for peripheral stimulation. We conclude that whisker protractions evoked by optogenetic activation of whisker pad muscles results in cortical activity and sensory perception, consistent with the coding of evoked whisker movements by reafferent sensory input.

  17. Numerical study of whisker field lines in the periphery of the Large Helical Device

    International Nuclear Information System (INIS)

    Akao, Hideki

    1990-01-01

    The behavior of periphery magnetic field lines in the standard Large-Helical Device (l=2 heliotron/torsatron type) configuration is studied numerically. Three different types of behavior are found, corresponding to three different regions: the stochastic region near the outermost magnetic surface, the whisker region, and the inter-whisker region outside the stochastic region. The behavior of whisker and inter-whisker field lines is specifically analyzed. It is found that whisker field lines exhibit both regular and irregular types of behavior, whereas inter-whisker field lines exhibit only regular behavior. The connection lengths for the whisker field lines are usually as long as several tens of toroidal pitches, whereas those for the inter-whisker field lines are usually less than ten toroidal pitch lengths. Whisker field lines are characterized by three fundamental processes; stretching, folding, and nesting associated with the motion of a residual X-point of the separatrix. Simple modeling is performed to reproduce these three fundamental processes. (author)

  18. The Effects of Oxidation Layer, Temperature, and Stress on Tin Whisker Growth: A Short Review

    Science.gov (United States)

    Mahim, Z.; Salleh, M. A. A.; Khor, C. Y.

    2018-03-01

    In order to reduce the Tin (Sn) whisker growth phenomenon in solder alloys, the researcher all the world has studied the factor of this behaviour. However, this phenomenon still hunted the electronic devices and industries. The whiskers growth were able to cause the electrical short, which would lead to the catastrophic such as plane crush, the failure of heart pacemaker, and the lost satellite connection. This article focuses on the three factors that influence the whiskers growth in solder alloys which is stress, oxidation layer and temperature. This findings were allowed the researchers to develop various method on how to reduce the growth of the Sn whiskers.

  19. Hydrothermal formation and characterization of magnesium oxysulfate whiskers

    International Nuclear Information System (INIS)

    Xiang, L.; Liu, F.; Li, J.; Jin, Y.

    2004-01-01

    Magnesium oxysulfate (5Mg(OH) 2 ·MgSO 4 ·3H 2 O) whiskers with a diameter of 0.2-1.0 μm and a length of 20-50 μm were synthesized via the hydrothermal treatment of the slurry formed by mixing the MgSO 4 and NaOH solutions at room temperature. The composition, morphology, structure and thermal behavior of the hydrothermal products were examined with X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermo-gravimetric analysis (TGA) and chemical analysis. The experimental results indicated that the process parameters, such as the concentration of the reactant, the dispersion of the Mg(OH) 2 slurry and the temperature in hydrothermal treatment should be controlled carefully to synthesis 5Mg(OH) 2 ·MgSO 4 ·3H 2 O whiskers and to avoid the formation of the sectorial or granular impurities. 5Mg(OH) 2 ·MgSO 4 ·3H 2 O whiskers were decomposed gradually and converted finally to MgO particles after being heated in air at temperature up to 1050 deg. C. Granular products formed if the heating temperature was above 320 deg. C

  20. The Formation of Graphite Whiskers in the Primitive Solar Nebula

    Science.gov (United States)

    Nuth, Joseph A., III; Kimura, Yuki; Lucas, Christopher; Ferguson, Frank; Johnson, Natasha M.

    2010-01-01

    It has been suggested that carbonaceous grains are efficiently destroyed in the interstellar medium and must either reform in situ at very low pressures and temperatures or in an alternative environment more conducive to grain growth. Graphite whiskers have been discovered associated with high-temperature phases in meteorites such as calcium aluminum inclusions and chondrules, and it has been suggested that the expulsion of such material from proto stellar nebulae could significantly affect the optical properties of the average interstellar grain population. We have experimentally studied the potential for Fischer-Tropsch and Haber-Bosch type reactions to produce organic materials in protostellar systems from the abundant H2, CO, and N2 reacting on the surfaces of available silicate grains. When graphite grains are repeatedly exposed to H2, CO, and N2 at 875 K abundant graphite whiskers are observed to form on or from the surfaces of the graphite grains. In a dense, turbulent nebula, such extended whiskers are very likely to be broken off, and fragments could be ejected either in polar jets or by photon pressure after transport to the outer reaches of the nebula.

  1. Synthesis of whiskers of SiC microwave assisted; Sintesis de whiskers de SiC asistida por microondas

    Energy Technology Data Exchange (ETDEWEB)

    Garza-Mendez, F. J.; Vanegas, A. J.; Vazquez, B. A.; Garza-Paz, J.

    2013-06-01

    We developed a new process for the synthesis of SiC whiskers assisted by microwaves; this is based on the mixture of silica xerogels and graphite powder. As energy source were used microwaves of 2.45 GHz and 1.0 kW of power RMS. On the other hand, mesoporous silica was synthesized via sol-gel, the precursors used were TEOS/H{sub 2}O and ethanol. Through analysis of the BET is determined the value of average pore size (3.0 nm) and the surface area (1090 m2/g).By mean of X-Ray diffraction it was demonstrated that the silica obtained is an amorphous solid and, the powders obtained in the microwave synthesis are {beta}-SiC. Synthesized SiC powders were observed using a SEM in secondary electron mode, it was observed that this powders consists of SiC whiskers. The effect of microwaves on the synthesis of whiskers of SiC is discussed in the present work. (Author) 19 refs.

  2. Barrel calorimeter of the CMD-3 detector

    Energy Technology Data Exchange (ETDEWEB)

    Shebalin, V. E., E-mail: V.E.Shebalin@inp.nsk.su; Anisenkov, A. V.; Aulchenko, V. M.; Bashtovoy, N. S. [Russian Academy of Sciences, Budker Institute of Nuclear Physics, Siberian Branch (Russian Federation); Epifanov, D. A. [University of Tokyo, Department of Physics (Japan); Epshteyn, L. B.; Grebenuk, A. A.; Ignatov, F. V.; Erofeev, A. L.; Kovalenko, O. A.; Kozyrev, A. N.; Kuzmin, A. S.; Logashenko, I. B.; Mikhailov, K. Yu.; Razuvaev, G. P.; Ruban, A. A.; Shwartz, B. A.; Talyshev, A. A.; Titov, V. M.; Yudin, Yu. V. [Russian Academy of Sciences, Budker Institute of Nuclear Physics, Siberian Branch (Russian Federation)

    2015-12-15

    The structure of the barrel calorimeter of the CMD-3 detector is presented in this work. The procedure of energy calibration of the calorimeter and the method of photon energy restoration are described. The distinctive feature of this barrel calorimeter is its combined structure; it is composed of two coaxial subsystems: a liquid xenon calorimeter and a crystalline CsI calorimeter. The calorimeter spatial resolution of the photon conversion point is about 2 mm, which corresponds to an angular resolution of ∼6 mrad. The energy resolution of the calorimeter is about 8% for photons with energy of 200 MeV and 4% for photons with energy of 1 GeV.

  3. Barrel calorimeter of the CMD-3 detector

    International Nuclear Information System (INIS)

    Shebalin, V. E.; Anisenkov, A. V.; Aulchenko, V. M.; Bashtovoy, N. S.; Epifanov, D. A.; Epshteyn, L. B.; Grebenuk, A. A.; Ignatov, F. V.; Erofeev, A. L.; Kovalenko, O. A.; Kozyrev, A. N.; Kuzmin, A. S.; Logashenko, I. B.; Mikhailov, K. Yu.; Razuvaev, G. P.; Ruban, A. A.; Shwartz, B. A.; Talyshev, A. A.; Titov, V. M.; Yudin, Yu. V.

    2015-01-01

    The structure of the barrel calorimeter of the CMD-3 detector is presented in this work. The procedure of energy calibration of the calorimeter and the method of photon energy restoration are described. The distinctive feature of this barrel calorimeter is its combined structure; it is composed of two coaxial subsystems: a liquid xenon calorimeter and a crystalline CsI calorimeter. The calorimeter spatial resolution of the photon conversion point is about 2 mm, which corresponds to an angular resolution of ∼6 mrad. The energy resolution of the calorimeter is about 8% for photons with energy of 200 MeV and 4% for photons with energy of 1 GeV

  4. Taxonomy Icon Data: barrel medic [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available barrel medic Medicago truncatula Medicago_truncatula_L.png Medicago_truncatula_NL.png Medi...cago_truncatula_S.png Medicago_truncatula_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Medi...cago+truncatula&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Medicago+truncatula&t=NL http://biosci...encedbc.jp/taxonomy_icon/icon.cgi?i=Medicago+truncatula&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Medicago+truncatula&t=NS ...

  5. First half of CMS inner tracker barrel

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    The first half of the CMS inner tracker barrel is seen in this image consisting of three layers of silicon modules which will be placed at the centre of the CMS experiment at the LHC in CERN. Laying close to the interaction point of the 14 TeV proton-proton collisions, the silicon used here must be able to survive high doses of radiation and a 4 T magnetic field without damage.

  6. Alignment of the MSGC barrel support structure

    International Nuclear Information System (INIS)

    Kari, Tammi; Miikka, Kotamaki; Tommi, Vanhala; Antti, Onnela

    1999-01-01

    The MSGC barrel is a sub-part of the tracking system of the CMS experiment at the LHC. The mechanical support structure of the MSGC barrel consists of ladder-like support beams carrying the detector modules and of four disks supporting the ladders. The required alignment precision of the modules, a few tens of micrometers, is designed to be obtained by precise part manufacture and by careful measurement of the alignment during the assembly of the structure. In the paper the use of digital photogrammetry for the measurement of the alignment of the disks and for the structural verification is presented. Digital photogrammetry was chosen from a number of potential methods after a careful evaluation. The use of photogrammetry for the structural verification of a prototype is presented. The displacements were measured both of unloaded and loaded disk by using photogrammetry and linear displacement transducers for verification. The displacements obtained from the two measurement methods corresponded well, not only to each other, but also to the results given by finite element analysis. The structural verification will be done and the alignment procedure will be tested with a full-sized prototype of a half of the MSGC barrel. Preparations for the photogrammetry measurements are presented and the design of the required supplementary equipment is shown. (authors)

  7. Alignment of the MSGC barrel support structure

    Energy Technology Data Exchange (ETDEWEB)

    Kari, Tammi; Miikka, Kotamaki; Tommi, Vanhala [HIP, Helsinki Institute of Physics, CERN/EP, Geneva (Switzerland); Antti, Onnela [CERN, Conseil Europeen pour la recherche nucleaire, Laboratoire europeen pour la physique des particules, Geneve (Switzerland)

    1999-07-01

    The MSGC barrel is a sub-part of the tracking system of the CMS experiment at the LHC. The mechanical support structure of the MSGC barrel consists of ladder-like support beams carrying the detector modules and of four disks supporting the ladders. The required alignment precision of the modules, a few tens of micrometers, is designed to be obtained by precise part manufacture and by careful measurement of the alignment during the assembly of the structure. In the paper the use of digital photogrammetry for the measurement of the alignment of the disks and for the structural verification is presented. Digital photogrammetry was chosen from a number of potential methods after a careful evaluation. The use of photogrammetry for the structural verification of a prototype is presented. The displacements were measured both of unloaded and loaded disk by using photogrammetry and linear displacement transducers for verification. The displacements obtained from the two measurement methods corresponded well, not only to each other, but also to the results given by finite element analysis. The structural verification will be done and the alignment procedure will be tested with a full-sized prototype of a half of the MSGC barrel. Preparations for the photogrammetry measurements are presented and the design of the required supplementary equipment is shown. (authors)

  8. Contributions of stress and oxidation on the formation of whiskers in Pb-free solders

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, A. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hoffman, E. N. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-01-01

    Understanding the environmental factors influencing formation of tin whiskers on electrodeposited lead free, tin coatings over copper (or copper containing) substrates is the topic of this study . An interim report* summarized initial observations as to the role of stress and oxide formation on whisker growth. From the initial results, two main areas were chosen to be the focus of additional research: the demonstration of effects of elastic stress state in the nucleation of whiskers and the confirmation of the effect of oxygen content in the formation of whiskers. Different levels of elastic stress were induced with the incorporation of a custom designed fixture that loaded the sample in a four-point bending configuration and were maintained in an environmental chamber under conditions deemed favorable for whisker growth. The effects of oxygen content were studied by aging substrates in gas vials of varying absolute pressure and different oxygen partial pressure.

  9. Effect of TiC whisker addition on properties of YG1OF alloy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The cemented carbide material (YG10F) with different additions of TiC whisker (0%, 0.3%, 0.6%, mass fraction) was prepared by different techniques. The effect of TiC whisker addition on the density, microhardness and toughness of the experimental material was investigated. The results indicate that after the wet-milling for 8 h and sintering in vacuum at 1 440 ℃, the toughness of YG10F is remarkably improved and meanwhile higher microhardness is obtained by 0.3% TiC whisker addition. Preliminary analysis suggests that the main toughening mechanism of TiC whisker in YG10F is whisker pull-out and bridging phenomena.

  10. Cerebral glucose utilization after vasopressin barrel rotation or bicuculline seizures

    International Nuclear Information System (INIS)

    Wurpel, J.; Dundore, R.; Bryan, R.; Keil, L.; Severs, W.B.

    1986-01-01

    Intraventricular (ivt) arginine vasopressin (AVP) causes a violent motor behavior termed barrel rotation (BR). AVP-BR is affected by visual/vestibular sensory input and may be related to other CNS motor disorders (seizures). Local cerebral glucose utilization (LCGU) was compared in SD rats during AVP-BR and bicuculline (BIC) seizures. Three groups were used: saline-ivt; AVP-ivt 0.5 μg; BIC-5.5 mg/kg,sc. 14 C-glucose (40 μCI iv) was injected 15 sec. after ivt-saline or AVP or onset of BIC seizures. Rats were decapitated 10 min. after 14 C-glucose. Brains were removed and dissected into 19 regions which were digested and glucose uptake quantified by liquid scintillation counting. LCGU was significantly increased in all CNS areas during BIC seizures vs controls (21-92%; p < 0.05 ANOVA). LCGU exhibits variable (upward arrow, downward arrow) changes in discrete areas during AVP-BR (p < .05). Glucose uptake increased in: cortex-olfactory (21%), sensory (9%), motor (8%) cerebellum-rt (13%) and 1t (17%) hemispheres, vermis (6%); pyramidal tract (6%); mesencephalon (5%); and pons (8%). Two areas decreased LCGU during AVP-BR: auditory cortex (-8%) and hippocampus (-11%). AVP-BR exhibits distinct changes in LCGU vs BIC seizures

  11. Strain gradient plasticity effects in whisker-reinforced metals

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof

    2002-01-01

    A metal reinforced by fibers in the micron range is studied using the strain gradient plasticity theory of Fleck and Hutchinson (2001). Cell-model analyzes are used to study the influence of the material length parameters numerically. Different higher order boundary conditions are considered...... at the fiber-matrix interface. The results are presented as overall stress-strain curves for the whisker-reinforced metal, and also contour plots of effective plastic strain are shown. The strain gradient plasticity theory predicts a significant stiffening effect when compared to conventional models...

  12. Microstructure and growth mechanism of tin whiskers on RESn3 compounds

    International Nuclear Information System (INIS)

    Li Caifu; Liu Zhiquan

    2013-01-01

    Graphical abstract: Large amount of intact tin whiskers were firstly prepared without post handling, and their microstructures were investigated systematically with TEM. A growth model was proposed to explain the observed growth characteristics from Sn–RE alloys. - Abstract: An exclusive method was developed to prepare intact tin whiskers as transmission electron microscope specimens, and with this technique in situ observation of tin whisker growth from RESn 3 (RE = Nd, La, Ce) film specimen was first achieved. Electron irradiation was discovered to have an effect on the growth of a tin whisker through its root. Large quantities of tin whiskers with diameters from 20 nm to 10 μm and lengths ranging from 50 nm to 500 μm were formed at a growth rate of 0.1–1.8 nm s −1 on the surface of RESn 3 compounds. Most (>85%) of these tin whiskers have preferred growth directions of 〈1 0 0〉, 〈0 0 1〉, 〈1 0 1〉 and 〈1 0 3〉, as determined by statistics. This kind of tin whisker is single-crystal β-Sn even if it has growth striations, steps and kinks, and no dislocations or twin or grain boundaries were observed within the whisker body. RESn 3 compounds undergo selective oxidation during whisker growth, and the oxidation provides continuous tin atoms for tin whisker growth until they are exhausted. The driving force for whisker growth is the compressive stress resulting from the restriction of the massive volume expansion (38–43%) during the oxidation by the surface RE(OH) 3 layer. Tin atoms diffuse and flow to feed the continuous growth of tin whiskers under a compressive stress gradient formed from the extrusion of tin atoms/clusters at weak points on the surface RE(OH) 3 layers. A growth model was proposed to discuss the characteristics and growth mechanism of tin whiskers from RESn 3 compounds.

  13. Robotic mounting of ATLAS barrel SCT modules

    International Nuclear Information System (INIS)

    Nickerson, R.B.; Viehhauser, G.; Wastie, R.; Terada, S.; Unno, Y.; Kohriki, T.; Ikegami, Y.; Hara, K.; Kobayashi, H.; Barbier, G.; Clark, A.G.; Perrin, E.; Carter, A.A.; Mistry, J.; Morris, J.

    2006-01-01

    The 2112 silicon detector modules of the barrel part of the ATLAS SemiConductor Tracker (SCT) have been mounted on their carbon fibre support structure. Module insertion, placement and fixing were performed by robotic assembly tooling. We report on our experience with this assembly method. Part of the mounting sequence involves a partial survey of elements of the support structure which is needed to align the modules properly during insertion. An analysis of these data is used to estimate the positional accuracy of the robots

  14. 3D Printing the ATLAS' barrel toroid

    CERN Document Server

    Goncalves, Tiago Barreiro

    2016-01-01

    The present report summarizes my work as part of the Summer Student Programme 2016 in the CERN IR-ECO-TSP department (International Relations – Education, Communication & Outreach – Teacher and Student Programmes). Particularly, I worked closely with the S’Cool LAB team on a science education project. This project included the 3D designing, 3D printing, and assembling of a model of the ATLAS’ barrel toroid. A detailed description of the project' development is presented and a short manual on how to use 3D printing software and hardware is attached.

  15. Crystalline instability of Bi-2212 superconducting whiskers near room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Cagliero, Stefano; Khan, Mohammad Mizanur Rahman [Torino Universita, ' NIS' Centre of Excellence, Dip. Chimica Generale e Chimica Organica, and CNISM UdR, Turin (Italy); Torino Universita, ' NIS' Centre of Excellence, Dip. Fisica Sperimentale, and CNISM UdR, Turin (Italy); Agostino, Angelo [Torino Universita, ' NIS' Centre of Excellence, Dip. Chimica Generale e Chimica Organica, and CNISM UdR, Turin (Italy); Truccato, Marco [Torino Universita, ' NIS' Centre of Excellence, Dip. Fisica Sperimentale, and CNISM UdR, Turin (Italy); Orsini, Francesco; Marinone, Massimo; Poletti, Giulio [Universita degli Studi di Milano, Istituto di Fisiologia Generale e Chimica Biologica, Milan (Italy); CNR-INFM-S3 NRC, Modena (Italy); Lascialfari, Alessandro [Universita degli Studi di Milano, Istituto di Fisiologia Generale e Chimica Biologica, Milan (Italy); CNR-INFM-S3 NRC, Modena (Italy); Universita degli Studi di Pavia, INFM-CNR c/o Dipartimento di Fisica A. Volta, Pavia (Italy)

    2009-05-15

    We report new evidences for the thermodynamic instability of whisker crystals in the Bi-Sr-Ca-Cu-O (BSCCO) system. Annealing treatments at 90 C have been performed on two sets of samples, which were monitored by means of X-rays diffraction (XRD) and atomic force microscopy (AFM) measurements, respectively. Two main crystalline domains of Bi{sub 2}Sr{sub 2}CuCa{sub 2}O{sub 8+x} (Bi-2212) were identified in the samples by the XRD data, which underwent an evident crystalline segregation after about 60 hours. Very fast dynamics of the surface modifications was also described by the AFM monitoring. Two typologies of surface structures formed after about 3 annealing hours: continuous arrays of dome shaped bodies were observed along the edges of the whiskers, while in the central regions a dense texture of flat bodies was found. These modifications are described in terms of the formation of simple oxide clusters involving a degradation of the internal layers. (orig.)

  16. Tin Whisker Electrical Short Circuit Characteristics. Part 2

    Science.gov (United States)

    Courey, Karim J.; Asfour, Shihab S.; Onar, Arzu; Bayliss, Jon A.; Ludwig, Lawrence L.; Wright, Maria C.

    2009-01-01

    Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that has an unknown probability associated with it. Note however that due to contact resistance electrical shorts may not occur at lower voltage levels. In our first article we developed an empirical probability model for tin whisker shorting. In this paper, we develop a more comprehensive empirical model using a refined experiment with a larger sample size, in which we studied the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit. From the resulting data we estimated the probability distribution of an electrical short, as a function of voltage. In addition, the unexpected polycrystalline structure seen in the focused ion beam (FIB) cross section in the first experiment was confirmed in this experiment using transmission electron microscopy (TEM). The FIB was also used to cross section two card guides to facilitate the measurement of the grain size of each card guide's tin plating to determine its finish.

  17. Irradiation induced creep in whiskers of NaCl

    International Nuclear Information System (INIS)

    Khan, J.A.A.

    1977-09-01

    Whiskers of NaCl have been grown and irradiated under flexion by X-rays (approximately 2x10 7 R/h) at room temperature and the residual curvature measured. Complete recovery of the initial form of the whisker within an hour's annealing at 400 0 C proves clearly that the observed deformation (creep) is due to the presence of dislocation loops. The choice of NaCl extremely simplifies the experiment and its interpretation since X-rays create point defects one by one. Moreover, this mode of irradiation, at room temperature, produces a very simple situation: perfect interstitial dislocation loops and immobile point defects which are little influenced by the applied stress. The flexion leads to a stress system which hardly differs from an uniaxial stress. One can study separately the preferential nucleation of dislocation loops and their differential growth by carrying out an irradiation under stress followed by an irradiation without stress and vice versa. It is shown that the induced creep is mostly due to the preferential nucleation of dislocation loops and is little affected by the differential growth of these loops. The nucleation period of the loops is very short: a dose of approximately 10 -5 d.p.a. is largely sufficient for the quasi completion of dislocation loops in a crystal having an impurity concentration of approximately 10 -3 [fr

  18. Failure analysis of a barrel exposed to high temperature

    International Nuclear Information System (INIS)

    Usman, A.; Salam, I.; Rizvi, S.A.; Qasir, S.

    2005-01-01

    The paper deals with the study of a tank gun barrel which had failed after firing only a few rounds. The failure was in the form of bulging at the muzzle end (ME). The material of the barrel was characterized using different techniques including chemical and mechanical testing, optical microscopy and electron microscopy. Study disclosed that the barrel was subjected to excessively high temperature that resulted in its softening and consequent bulging under high pressure of the round. (author)

  19. Microstructure and fracture in SiC whisker reinforced 2124 aluminum composite

    Science.gov (United States)

    Nieh, T. G.; Raninen, R. A.; Chellman, D. J.

    1985-01-01

    The microstructures of extruded and hot-rolled 2124 Al-15 percent (by weight) SiC whisker composites have been investigated, experimentally. Among the specific factors studied were: the strength of the whisker-matrix interfaces; (2) the presence of oxides; (3) the presence of defective whiskers; (4) and the presence of distribution of intermetallic compounds, impurities in the SiC(w) powder, and microstructural inhomogeneities. Modifications in the microstructure of the SiC/AL composites due to hot rolling and extrusion are illustrated in a series of microphotographs. It was found that hot rolling along the axis of extrusion was associated with some types of whisker damage, while the whiskers still retain their original orientation. Hot-rolling perpendicular to the axis of extrusion, however, tended to rotate the whiskers and produced a nearly isotropic material. Whisker free zones were virtually eliminated or reduced in size by hot rolling. In situ Auger fractography of the composite showed that the interfacial bonding between the SiC and the Al matrix was good and that Al2O2 had no significant influence on the fracture mechanics of the composite.

  20. The development of SiC whisker fabrication technology for nuclear applications

    International Nuclear Information System (INIS)

    Kang, Thae Khapp; Kuk, Il Hiun; Lee, Jae Chun; Rhee, Chang Kyu; Lee, Ho Jin; Park, Soon Dong

    1990-02-01

    Important process factors of carbothermic process for the growth of SiC whiskers were investigated. The crystalline form of silicon dioxide, amount of carbon addition, graphite, silicon, catalysts, additive and reaction temperature were chosen as the main factors. Morphology of the resultant products was grouped into 3 different types; whisker,noodle and power types. The addition of catalyst affected in most the formation of SiC whiskers. Effects of catalyst and additive additions and reaction atmospheres on the morphology anf growth of SiC whiskers were investigated, silicon monoxide power and carbon monoxide gas were used as the raw materials. The addition of an iron containing catalyst resulted in a very long thread-like growth of the whiskers, while that of sodium chloride helical curlings. Addition of hydrogen to the non-oxidizing atmosphere enhanced the whisker formations. Crystallization of amorphous silicon monoxide raw powder was investigated at high temperatures up to 1500 deg C in Ar atmosphere using graphite crucible. Up to 900 deg C no crystallization occurred, while at 1100 - 1300 deg C silicon formation, and at 1500 deg C silicon dioxide and silicon carbide formations were detected. A slight weight loss began 1300 deg C, and the weight loss became about 33 % at 1500 deg C. After the formation reaction of SiC whiskers, the reaction products were leached by hydrofluoric acids. The optimum concentration of the hydrofluoric acid was 2 %. (author)

  1. Effect of linear alcohol molecular size on the self-assembly of fullerene whiskers

    International Nuclear Information System (INIS)

    Amer, Maher S.; Todd, T. Kyle; Busbee, John D.

    2011-01-01

    Highlights: → The longer the alcohol molecule, the shorter the length of the assembled whisker. → Interaction between alcohol and fullerene solvent is the key factor. → The stronger the alcohol/solvent interaction, the longer the whisker. - Abstract: The recent development of self-assembled fullerene whiskers and wires has created an enormous potential and resolved a serious challenge for utilizing such unique class of carbon material in advanced nano-scale, molecular-based electronic, optical, and thermal devices. In this paper we investigate, the self-assembly of C 60 molecules into one-dimensional whiskers using a series of linear alcohols H(CH 2 ) n OH, with n changing from 1 (methanol) to 3 (isopropyl alcohol), to elucidate the effect of alcohol molecular size on the size distribution of the self-assemble fullerene whiskers. Our results show that the length of the produced fullerene whiskers is affected by the molecular size of the alcohol used in the process. The crucial role played by solvent/alcohol interaction in the assembly process is discussed. In addition, Raman spectroscopy measurements support the notion that the self-assembled whiskers are primarily held by depletion forces and no evidence of fullerene polymerization was observed.

  2. Progress of the EM Barrel Presampler Assembly

    CERN Multimedia

    Hostachy, J.Y.

    The liquid argon barrel presampler is a separate detector which will be placed in front of the electromagnetic barrel calorimeter, in the same cryostat. It is made of 32×2 sectors, each of them being 3.1 m long, about 28 cm large and a few cm thick. Three countries are involved in its construction: France (ISN-Grenoble), Sweden (KTH-Stockholm) and Morocco (Universities: Hassan II Ain Chock-Casablanca and Mohamed V-Rabat, and CNESTEN-Rabat). The design of the presampler started ten years ago and the series production began at the end of the year 2000. Today two-thirds of the sectors are produced and validated. In November 2002, half the detector (i.e. 32 sectors), was inserted on the internal face of the first EM calorimeter wheel (see pictures). Despite the fact that only 0.4 mm was available between sectors, it was possible to insert them all without meeting major difficulties. This operation was led by a team of four people, the sectors being systematically tested after insertion in the wheel. The inserti...

  3. ATLAS TRT Barrel in Test Beam

    CERN Multimedia

    Luehring, F

    In July, the TRT group made a highly successful test of 6 Barrel TRT modules in the ATLAS H8 testbeam. Over 3000 TRT straw tubes (4 mm diameter gas drift tubes) were instrumented and found to operate well. The prototype represents 1/16 of the ATLAS TRT barrel and was assembled from TRT modules produced as spares. This was the largest scale test of the TRT to this date and the measured detector performance was as good as or better than what was expected in all cases. The 2004 TRT testbeam setup before final cabling was attached. The readout chain and central DAQ system used in the TRT testbeam is a final prototype for the ATLAS experiment. The TRT electronics used to read out the data were: The Amplifier/Shaper/Discriminator with Baseline Restoration (ASDBLR) chip is the front-end analog chip that shapes and discriminates the electronic pulses generated by the TRT straws. The Digital Time Measurement Read Out Chip (DTMROC) measures the time of the pulse relative to the beam crossing time. The TRT-ROD ...

  4. Cosmic Ray Data in TRT Barrel

    CERN Multimedia

    M. Hance

    "I had a great day in August when I went into SR1," said Daniel Froidevaux, former project leader of the ATLAS Transition Radiation Tracker, "not only had all SCT barrels arrived at CERN, but there were cosmic ray tracks seen in the TRT!" Daniel's excitement was mirrored by the rest of the TRT collaboration when, on July 29, the first cosmic ray tracks were seen in the barrel. Along with many others in the community, Daniel was quick to point out that this is the cumulative result of years of R&D, test beam work, and an intense installation and integration schedule. Indeed, the cosmic ray readout is only possible through the coordination of many efforts, from detector mechanics to module assembly, power and high voltage control, cooling, gas systems, electronics and cabling, data acquisition, and monitoring. "Many people have worked very hard on the the TRT, some of them for more than 10 years," said Brig Williams, the leader of the UPenn group responsible for much of the TRT front end electronics. He ...

  5. The CMS Barrel Muon Trigger Upgrade

    CERN Document Server

    Triossi, Andrea

    2017-01-01

    ABSTRACT: The increase of luminosity expected by LHC during Phase 1 will impose several constrains for rate reduction while maintaining high efficiency in the CMS Level 1 trigger system. The TwinMux system is the early layer of the muon barrel region that concentrates the information from different subdetectors DT, RPC and HO. It arranges and fan-out the slow optical trigger links from the detector chambers into faster links (10 Gbps) that are sent to the track finders. Results, from collision runs, that confirm the satisfactory operation of the trigger system up to the output of the barrel track finder, will be shown. SUMMARY: In view of the increase of luminosity during phase 1 upgrade of LHC, the muon trigger chain of the Compact Muon Solenoid (CMS) experiment underwent considerable improvements. The muon detector was designed for preserving the complementarity and redundancy of three separate muon detection systems, Cathode Strip Chambers (CSC), Drift Tubes (DT) and Resistive Plate Chambers (RPC), until ...

  6. Calcium silicate ceramic scaffolds toughened with hydroxyapatite whiskers for bone tissue engineering

    International Nuclear Information System (INIS)

    Feng, Pei; Wei, Pingpin; Li, Pengjian; Gao, Chengde; Shuai, Cijun; Peng, Shuping

    2014-01-01

    Calcium silicate possessed excellent biocompatibility, bioactivity and degradability, while the high brittleness limited its application in load-bearing sites. Hydroxyapatite whiskers ranging from 0 to 30 wt.% were incorporated into the calcium silicate matrix to improve the strength and fracture resistance. Porous scaffolds were fabricated by selective laser sintering. The effects of hydroxyapatite whiskers on the mechanical properties and toughening mechanisms were investigated. The results showed that the scaffolds had a uniform and continuous inner network with the pore size ranging between 0.5 mm and 0.8 mm. The mechanical properties were enhanced with increasing hydroxyapatite whiskers, reached a maximum at 20 wt.% (compressive strength: 27.28 MPa, compressive Young's modulus: 156.2 MPa, flexural strength: 15.64 MPa and fracture toughness: 1.43 MPa·m 1/2 ) and then decreased by addition of more hydroxyapatite whiskers. The improvement of mechanical properties was due to whisker pull-out, crack deflection and crack bridging. Moreover, the degradation rate decreased with the increase of hydroxyapatite whisker content. A layer of bone-like apatite was formed on the scaffold surfaces after being soaked in simulated body fluid. Human osteoblast-like MG-63 cells spread well on the scaffolds and proliferated with increasing culture time. These findings suggested that the calcium silicate scaffolds reinforced with hydroxyapatite whiskers showed great potential for bone regeneration and tissue engineering applications. - Highlights: • HA whiskers were incorporated into CS to improve the properties. • The scaffolds were successfully fabricated by SLS. • Toughening mechanisms was whisker pull-out, crack deflection and bridging. • The scaffolds showed excellent apatite forming ability

  7. Calcium silicate ceramic scaffolds toughened with hydroxyapatite whiskers for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Pei [State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, PR China, (China); Wei, Pingpin [Cancer Research Institute, Central South University, Changsha 410078 (China); Li, Pengjian; Gao, Chengde [State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, PR China, (China); Shuai, Cijun, E-mail: shuai@csu.edu.cn [State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, PR China, (China); Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC 29425 (United States); Peng, Shuping, E-mail: shuping@csu.edu.cn [Cancer Research Institute, Central South University, Changsha 410078 (China)

    2014-11-15

    Calcium silicate possessed excellent biocompatibility, bioactivity and degradability, while the high brittleness limited its application in load-bearing sites. Hydroxyapatite whiskers ranging from 0 to 30 wt.% were incorporated into the calcium silicate matrix to improve the strength and fracture resistance. Porous scaffolds were fabricated by selective laser sintering. The effects of hydroxyapatite whiskers on the mechanical properties and toughening mechanisms were investigated. The results showed that the scaffolds had a uniform and continuous inner network with the pore size ranging between 0.5 mm and 0.8 mm. The mechanical properties were enhanced with increasing hydroxyapatite whiskers, reached a maximum at 20 wt.% (compressive strength: 27.28 MPa, compressive Young's modulus: 156.2 MPa, flexural strength: 15.64 MPa and fracture toughness: 1.43 MPa·m{sup 1/2}) and then decreased by addition of more hydroxyapatite whiskers. The improvement of mechanical properties was due to whisker pull-out, crack deflection and crack bridging. Moreover, the degradation rate decreased with the increase of hydroxyapatite whisker content. A layer of bone-like apatite was formed on the scaffold surfaces after being soaked in simulated body fluid. Human osteoblast-like MG-63 cells spread well on the scaffolds and proliferated with increasing culture time. These findings suggested that the calcium silicate scaffolds reinforced with hydroxyapatite whiskers showed great potential for bone regeneration and tissue engineering applications. - Highlights: • HA whiskers were incorporated into CS to improve the properties. • The scaffolds were successfully fabricated by SLS. • Toughening mechanisms was whisker pull-out, crack deflection and bridging. • The scaffolds showed excellent apatite forming ability.

  8. Characterization of microstructure of Si3N4 whisker reinforced glass ceramic

    International Nuclear Information System (INIS)

    Han, Byoung Sung; Choi, Shung Shaon

    1993-01-01

    Glass ceramics, especially fiber-reinforced composite ceramics, have attracted a great deal of attention in improving the reliability of ceramic components because of the improvement in various mechanical properties. Through hot-pressing and sintering, 225 cordierite was transformed with glass ceramic and mullite phase. Particularly glass glain size increased with the increasing of the sintering temperature and the heat treatment enhance the toughness and hardness of materials. Like the increased sintering temperature, the roughness increased with increasing whisker vol.%. In case of whisker-rinforced glass ceramic, the fracture surface of samples has been associated with a whisker orientation of samples. (Author)

  9. Effects of local film properties on the nucleation and growth of tin whiskers and hillocks

    Science.gov (United States)

    Sarobol, Pylin

    Whiskers and hillocks grow spontaneously on Pb-free Sn electrodeposited films as a response to thin film stresses. Stress relaxation occurs by atom deposition to specific grain boundaries in the plane of the film, with hillocks being formed when grain boundary migration accompanies growth out of the plane of the film. The implication for whisker formation in electronics is serious: whiskers can grow to be millimeters long, sometimes causing short circuiting between adjacent components and, thereby, posing serious electrical reliability risks. In order to develop more effective whisker mitigation strategies, a predictive physics-based model has been needed. A growth model is developed, based on grain boundary faceting, localized Coble creep, as well as grain boundary sliding for whiskers, and grain boundary sliding with shear induced grain boundary migration for hillocks. In this model of whisker formation, two mechanisms are important: accretion of atoms by Coble creep on grain boundary planes normal to the growth direction inducing a grain boundary shear and grain boundary sliding in the direction of whisker growth. The model accurately captures the importance of the geometry of "surface grains"---shallow grains on film surfaces whose depths are significantly less than their in-plane grain sizes. A critical factor in the analysis is the ratio of the grain boundary sliding coefficient to the in-plane film compressive stress. If the accretion-induced shear stresses are not coupled to grain boundary motion and sliding occurs, a whisker forms. If the shear stress is coupled to grain boundary migration, a hillock forms. Based on this model, long whiskers grow from shallow surface grains with easy grain boundary sliding in the direction of growth. Other observed growth morphologies will be discussed in light of our model. Additional insights into the preferred sites for whisker and hillock growth were developed based on elastic anisotropy, local film microstructure

  10. Improved mechanical properties of hydroxyapatite whisker-reinforced poly(L-lactic acid) scaffold by surface modification of hydroxyapatite.

    Science.gov (United States)

    Fang, Zhou; Feng, Qingling

    2014-02-01

    To improve the mechanical properties of porous hydroxyapatite/poly(L-lactic acid) (HA/PLLA) composites, HA whiskers with high crystallinity and high aspect ratio were synthesized. HA whiskers were modified with γ-aminopropyltriethoxysilane (APTES) to improve the interface between HA whiskers and PLLA. The composite scaffold consists of a porous PLLA matrix with HA whiskers distributed homogeneously. The morphology and the distributions of pore sizes of PLLA scaffold was not influenced by introducing HA whiskers, while the mechanical properties were improved. Both the compressive strength and compressive modulus were increased with the weight ratio of APTES-modified HA whiskers up to 30 wt.%, but only up to 15 wt.% for non-modified HA whiskers. With more than 15 wt.% HA whiskers, the mechanical properties of HA/PLLA scaffold were better improved with APTES-modified HA whiskers than non-modified. The HA whisker/PLLA scaffold with high porosity and improved mechanical properties is attractive in the application of tissue engineering. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. 27 CFR 25.141 - Barrels and kegs.

    Science.gov (United States)

    2010-04-01

    ... OF THE TREASURY LIQUORS BEER Marks, Brands, and Labels § 25.141 Barrels and kegs. (a) General... shown on the bung or on the tap cover, or on a label securely affixed to each barrel or keg, the place... production: (i) May be shown as the only location on the bung, or on the tap cover, or on a separate label...

  12. Scraping the bottom of the barrel

    Energy Technology Data Exchange (ETDEWEB)

    Leite, L.F. [PETROBRAS (Brazil)

    2001-03-01

    This article focuses on technologies for upgrading residual streams to improve refiners margins, and reports on the refining technology programme (PROTER) set up by the Brazilian PETROBRAS company. Details are given of fluid catalytic cracking (FCC) pilot units at PETROBRAS's CENPES Research and Development Centre in Rio de Janeiro State, the development of new proprietary closed cyclone technology, the Ultramist feedstock injection device, the feed nozzle, and the high accessibility catalyst. FCC units at PETROBRAS, FCC ongoing projects, and the use of delayed coking to convert low value residues to high value residues are described along with other bottom of barrel projects such as residue hydrocracking, hydropyrolysis, and the production of a stable fuel emulsion from an asphalt residue stream.

  13. Structure and Properties of Chitin Whisker Reinforced Papers for Food Packaging Application

    Directory of Open Access Journals (Sweden)

    Zhihan Li

    2015-04-01

    Full Text Available In recent years, concerns about environmental waste caused by petroleum-derived chemicals as well as the consumer's demand for high quality food products, have prompted people to pay more attention to developing biodegradable food packaging materials using natural resources such as cellulose fibers and chitin derivatives. In this study, chitin whiskers have been successfully generated by hydrolyzing the α-chitin sample. Then the synthesized nano-sized chitin whiskers were used at ratios from 0.1% to 2% (wt% for improving strength properties of paper sheets by the dip-coating method. Transmission electron microscopy (TEM and field emission scanning electron microscopy (FE-SEM were used to investigate the morphology of chitin whiskers and cellulose fiber compounds. The results showed that coating with chitin whiskers brought about an increase in tear strength, burst strength, and wet and dry tensile strength, with a decrease in Zeta-potential value.

  14. Silicon carbide whiskers with superlattice structure: A precursor for a new type of nanoreactor

    International Nuclear Information System (INIS)

    Lutsenko, Vadym G.

    2008-01-01

    Silicon carbide whiskers exhibit growth predominantly in the direction. The high level of impurities, stacking faults and nanosized twins govern the formation of homojunctions and heterojunctions in crystals. The structure of the whiskers comprises a hybrid superlattice, i.e. contains elements of doped and composite superlattices. An individual SiC whisker can contain hundreds of quantum wells with anomalous chemical properties. This paper shows that it is possible to selectively etch quantum wells and to construct whiskers with quasi-regularly distributed slit-like nanopores (nanoreactors), which are bordered by polar planes {1 1 1}, {0 0 0 1} or a combination of them, and also to produce flat SiC nanocrystals bordered by polar planes

  15. Hydrothermal Formation Of Hemi-hydrate Calcium Sulfate Whiskers In The Presence Of Additives

    International Nuclear Information System (INIS)

    Luo, K. B.; Li, C. M.; Li, H. P.; Ning, P.; Xiang, L.

    2010-01-01

    The influence of addictives on the hydrothermal formation of hemi-hydrate calcium sulfate (CaSO 4 ·0.5H 2 O) whiskers were discussed in this paper, using CaCl 2 and Na 2 SO 4 as the reactants. The presence of NaCl, CaCl 2 or Na 2 SO 4 increased the concentrations of Ca 2+ and SO 4 2- , leading to the formation of CaSO 4 ·0.5H 2 O whiskers with aspect ratio lower than 50. The one dimensional growth of CaSO 4 ·0.5H 2 O whiskers was enhanced in water with no additives owing to the low super-saturation, leading to the formation of uniform whiskers with a length of 200-2000 μm and an aspect ratio higher than 100.

  16. Properties of ZnO whiskers under CO2-laser irradiation

    International Nuclear Information System (INIS)

    Shkumbatyuk, P. S.

    2010-01-01

    Needlelike ZnO single crystals (whiskers) 0.3-0.8 mm long and 1-10 μm in diameter with a resistivity from 3 x 10 2 to 1 Ω cm have been grown under cw CO 2 -laser irradiation. The whiskers exhibit weak electroluminescence caused by injection from contacts with participation of intrinsic defects, which affect the electric field distribution.

  17. Growth of cadmium oxide whiskers on cadmium sulphide single crystals with copper as growth activator

    Energy Technology Data Exchange (ETDEWEB)

    Koparanova, N.; Simov, S. (Bylgarska Akademiya na Naukite, Sofia. Inst. po Fizika na Tvyrdoto Tyalo); Genchev, D. (Bylgarska Akademiya na Naukite, Sofia. Inst. za Yadrena Izsledvaniya i Yadrena Energetika); Metchenov, G. (Research Inst. of Criminalistics and Criminology, Sofia (Bulgaria))

    1985-02-01

    Some results on the growth and morphology of cadmium oxide whiskers, obtained on cadmium sulphide single crystals with copper as a growth activator, are presented in this work. Cadmium oxide whiskers have been obtained on brace 112-bar0 brace faces of cadmium sulphide plates with a copper layer deposited in advance. The whiskers grew during the annealing of the plates in a weak stream of technically pure argon at temperatures 670 to 730 deg C for 15 min to 3.5 h. Details about the procedure have been given elsewhere. The composition and morphology of the whiskers have been studied by an X-ray microanalyser JEOL 35 DDS and a scanning electron microscope JEOL, JSM 35. The optical microscopic observations have shown that after annealing, a gray-black granular layer is formed on the cadmium sulphide single crystals and this layer can easily be separated from the crystal substrate. Under the granular layer the crystal is heavily damaged. The whiskers grow on the granular layer and they are coloured yellow-brown or red-brown. The maximum whisker length attains several hundreds of micrometres and in some cases up to 1 mm or more.

  18. Growth of cadmium oxide whiskers on cadmium sulphide single crystals with copper as growth activator

    International Nuclear Information System (INIS)

    Koparanova, N.; Simov, S.

    1985-01-01

    Some results on the growth and morphology of cadmium oxide whiskers, obtained on cadmium sulphide single crystals with copper as a growth activator, are presented in this work. Cadmium oxide whiskers have been obtained on brace 112-bar0 brace faces of cadmium sulphide plates with a copper layer deposited in advance. The whiskers grew during the annealing of the plates in a weak stream of technically pure argon at temperatures 670 to 730 deg C for 15 min to 3.5 h. Details about the procedure have been given elsewhere. The composition and morphology of the whiskers have been studied by an X-ray microanalyser JEOL 35 DDS and a scanning electron microscope JEOL, JSM 35. The optical microscopic observations have shown that after annealing, a gray-black granular layer is formed on the cadmium sulphide single crystals and this layer can easily be separated from the crystal substrate. Under the granular layer the crystal is heavily damaged. The whiskers grow on the granular layer and they are coloured yellow-brown or red-brown. The maximum whisker length attains several hundreds of micrometres and in some cases up to 1 mm or more. (author)

  19. Globally intertwined evolutionary history of giant barrel sponges

    Science.gov (United States)

    Swierts, Thomas; Peijnenburg, Katja T. C. A.; de Leeuw, Christiaan A.; Breeuwer, Johannes A. J.; Cleary, Daniel F. R.; de Voogd, Nicole J.

    2017-09-01

    Three species of giant barrel sponge are currently recognized in two distinct geographic regions, the tropical Atlantic and the Indo-Pacific. In this study, we used molecular techniques to study populations of giant barrel sponges across the globe and assessed whether the genetic structure of these populations agreed with current taxonomic consensus or, in contrast, whether there was evidence of cryptic species. Using molecular data, we assessed whether giant barrel sponges in each oceanic realm represented separate monophyletic lineages. Giant barrel sponges from 17 coral reef systems across the globe were sequenced for mitochondrial (partial CO1 and ATP6 genes) and nuclear (ATPsβ intron) DNA markers. In total, we obtained 395 combined sequences of the mitochondrial CO1 and ATP6 markers, which resulted in 17 different haplotypes. We compared a phylogenetic tree constructed from 285 alleles of the nuclear intron ATPsβ to the 17 mitochondrial haplotypes. Congruent patterns between mitochondrial and nuclear gene trees of giant barrel sponges provided evidence for the existence of multiple reproductively isolated species, particularly where they occurred in sympatry. The species complexes in the tropical Atlantic and the Indo-Pacific, however, do not form separate monophyletic lineages. This rules out the scenario that one species of giant barrel sponge developed into separate species complexes following geographic separation and instead suggests that multiple species of giant barrel sponges already existed prior to the physical separation of the Indo-Pacific and tropical Atlantic.

  20. In-situ measurement of bending strength of TiC whiskers in the scanning electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Seino, Yutaka; Shin, Shoichiro; Nagai, Satoshi [National Research Lab. of Metrology, Tsukuba, Ibaraki (Japan)

    1995-10-01

    The three-point bending strength of TiC whiskers was measured in a scanning electron microscope. The whisker samples have {approximately} 50 {micro}m length and 2 {approximately} 4 {micro}m diameter and are commercially available as reinforcements. For composite materials. The distribution of the bending strengths of the whiskers showed a double peak around 5.2GPa and 30.4GPa, respectively. The difference in these values is attributed to differences in the cleavage strength of two crystal planes depending on whisker growth direction.

  1. Monitoring core barrel motion by neutron noise diagnostics

    International Nuclear Information System (INIS)

    Por, G.

    1985-08-01

    The core barrel motion is detected by ionization chambers located around the reactor vessel. The method is based on the measurement of the neutron flux fluctuations. Calculations to determine the direction and the size of the motion are discussed. The identification of core barrel motion and its connection with the error of one of the main circulating pumps in the Rheinsberg nuclear power plant are described. Core barrel motion of 10 Hz with an amplitude less than 50 μm could be diagnozed at the Paks-1 reactor using the Dutch high accuracy evaluation system. (V.N.)

  2. Construction and performance of the ATLAS silicon microstrip barrel modules

    International Nuclear Information System (INIS)

    Kondo, T.; Apsimon, R.; Beck, G.A.; Bell, P.; Brenner, R.; Bruckman de Renstrom, P.; Carter, A.A.; Carter, J.R.; Charlton, D.; Dabrowski, W.; Dorholt, O.; Ekelof, T.; Eklund, L.; Gibson, M.; Gadomski, S.; Grillo, A.; Grosse-Knetter, J.; Haber, C.; Hara, K.; Hill, J.C.; Ikegami, Y.; Iwata, Y.; Johansen, L.G.; Kohriki, T.; Macpherson, A.; McMahon, S.; Moorhead, G.; Morin, J.; Morris, J.; Morrissey, M.; Nagai, K.; Nakano, I.; Pater, J.; Pernegger, H.; Perrin, E.; Phillips, P.; Robinson, D.; Skubic, B.; Spencer, N.; Stapnes, S.; Stugu, B.; Takashima, R.; Terada, S.; Tyndel, M.; Ujiie, N.; Unno, Y.; Vos, M.

    2002-01-01

    The ATLAS Semiconductor Tracker (SCT) consists of four barrel cylinders and 18 end-cap disks. This paper describes the SCT modules of the barrel region, of which more than 2000 are about to be constructed. The module design is fixed. Its design concept is given together with the electrical, thermal and mechanical specifications. The pre-series production of the barrel modules is underway using mass-production procedures and jigs. The pre-series modules have given satisfactory performances on noise, noise occupancy, electrical as well as mechanical and thermal properties. In addition, irradiated modules were demonstrated to work successfully. Also first results from a 10-module system test are given

  3. Qualification Procedures of the CMS Pixel Barrel Modules

    CERN Document Server

    Starodumov, A; Horisberger, R.; Kastli, H.Chr.; Kotlinski, D.; Langenegger, U.; Meier, B.; Rohe, T.; Trueb, P.

    2006-01-01

    The CMS pixel barrel system will consist of three layers built of about 800 modules. One module contains 66560 readout channels and the full pixel barrel system about 48 million channels. It is mandatory to test each channel for functionality, noise level, trimming mechanism, and bump bonding quality. Different methods to determine the bump bonding yield with electrical measurements have been developed. Measurements of several operational parameters are also included in the qualification procedure. Among them are pixel noise, gains and pedestals. Test and qualification procedures of the pixel barrel modules are described and some results are presented.

  4. Beam tests of the ZEUS barrel calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, A; Bienz, T; Caldwell, A; Chen, L; Derrick, M; Gialas, I; Hamri, A; Imlay, R; Kartik, S; Kim, H J; Kinnel, T; Kreutzmann, H; Li, C G; Lim, J N; Loveless, R; Lu, B; Mallik, U; McLean, K W; McNeil, R; Metcalf, W; Musgrave, B; Oh, B Y; Park, S; Parsons, J A; Reeder, D; Repond, J; Ritz, S; Roco, M T.P.; Sandler, P H; Sciulli, F; Smith, W H; Talaga, R L; Tzanakos, G; Wai, L; Wang, M Z; Whitmore, J; Wu, J; Yang, S [Argonne National Lab., IL (United States) Columbia Univ., New York, NY (United States) Nevis Labs., Irvington-on-Hudson, NY (United States) Univ. of Iowa, Iowa City, IA (United States) Louisiana State Univ., Baton Rouge, LA (United States) Ohio State Univ., Columbus, OH (United States) Pennsylvania State Univ., University Park, PA (United States) Virginia Polytechnic Inst., and State Univ., Blacksburg, VA (United States) Univ. of Wisconsin, Madison, WI (United States)

    1993-11-15

    A fully compensating uranium-scintillator calorimeter was constructed for the ZEUS detector at HERA. Several of the barrel calorimeter modules were subjected to beam tests at Fermilab before shipping them to DESY for installation. The calibrations of the modules used beams of electrons and hadrons, measuring the uniformity of the response, and checking the resolution. The runs also provided opportunity to test a large fraction of the actual ZEUS calorimeter readout system in an integrated beam environment more than one year before HERA turn on. The experiment utilized two computer controlled mechanical structures, one of which was capable of holding up to four modules in order to study shower containment, and a magnetic spectrometer with a high resolution beam tracking system. During two running periods, beams of 6 to 110 GeV containing e, [mu], [pi], and anti p were used. The results show energy resolutions of 35%/[radical]E for hadrons and 19%/[radical]E for electrons, uniformities at the 1% level, energy nonlinearity less than 1%, and equal response for electrons and hadrons. (orig.)

  5. Common barrel and forward CA tracking algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Mykhailo, Pugach [Goethe-Universitaet, Frankfurt (Germany); Frankfurt Institute for Advanced Studies, Frankfurt (Germany); KINR, Kyiv (Ukraine); Gorbunov, Sergey; Kisel, Ivan [Goethe-Universitaet, Frankfurt (Germany); Frankfurt Institute for Advanced Studies, Frankfurt (Germany); Collaboration: PANDA-Collaboration

    2016-07-01

    There are complex detector setups which consist of barrel (cylindrical) and forward parts, and such systems require a special approach in the registered charged particles track finding procedure. Currently the tracking procedure might be performed in both parts of such detector independently from each other, but the final goal on this direction is a creation of a combined tracking, which will work in both parts of the detector simultaneously. The basic algorithm is based on Kalman Filter (KF) and Cellular Automata (CA). And the tracking procedure in such a complex system is rather extraordinary as far as it requires 2 different models to describe the state vector of segments of the reconstructed track in the mathematical apparatus of the KF-algorithm. To overcome this specifics a mathematical apparatus of transition matrices must be developed and implemented, so that one can transfer from one track model to another. Afterwards the work of the CA is performed, which reduces to segments sorting, their union into track-candidates and selection of the best candidates by the chi-square criteria after fitting of the track-candidate by the KF. In this report the algorithm, status and perspectives of such combined tracking are described.

  6. Prototype test for the PANDA barrel DIRC

    Energy Technology Data Exchange (ETDEWEB)

    Dzhygadlo, Roman; Gerhardt, Andreas; Kalicy, Grzegorz; Krebs, Marvin; Lehmann, Dorothe; Schwarz, Carsten; Schwiening, Jochen; Belias, Anastasios; Traxler, Michael [GSI Helmholtzzentrum fur Schwerionenforschung GmbH, Darmstadt (Germany); Peters, Klaus [GSI Helmholtzzentrum fur Schwerionenforschung GmbH, Darmstadt (Germany); Goethe-Universitaet Frankfurt (Germany); Collaboration: PANDA-Collaboration

    2016-07-01

    The Barrel DIRC (Detector of Internally Reflected Cherenkov light) is designed to provide particle identification (PID) for the PANDA experiment at the new Facility for Antiproton and Ion Research in Europe (FAIR) at GSI, Darmstadt. It is based on the successful BABAR DIRC detector with several key improvements, such as focusing optics, fast timing, and a compact expansion volume. A large prototype was constructed and tested in a hadronic particle beam at CERN during the summer of 2015 to test the PID performance of different design options. The prototype included a fused silica radiator (either a narrow bar or a wide plate), an optional focusing lens, and a prism-shaped fused silica expansion volume. An array of microchannel-plate photomultiplier tubes measured the location and arrival time of the Cherenkov photons on 960 pixels. Data were collected for two radiator geometries and several types of focusing lenses at different beam momenta and polar angles. Results of the analysis as well as a comparison to the Geant4 simulation are presented.

  7. Comparison between two possible CMS Barrel Muon Readout Architectures

    International Nuclear Information System (INIS)

    Aguayo, P.; Barcala, J.M.; Molinero, A.; Pablos, J.L.; Willmott, C.; Alberdi, J.; Marin, J.; Navarrete, J.; Romero, L.

    1997-01-01

    A comparison between two possible readout arquitectures for the CMS muon barrel readout electronics is presented, including various aspects like costs, reliability, installation, staging and maintenance. A review of the present baseline architecture is given in the appendix. (Author)

  8. Tri-Service Green Gun Barrel (PP 1074)

    National Research Council Canada - National Science Library

    Rusch, Lawrence F

    2003-01-01

    ...) PP 1074 Tri-Service Green Gun Barrel. The program's goal was to develop an environmentally friendly process for depositing wear and erosion resistant materials onto gun bores replacing the current hazardous aqueous electro-deposition...

  9. Experimental investigation on shore hardness of barrel-finished ...

    Indian Academy of Sciences (India)

    Rupinder Singh

    2017-08-02

    Aug 2, 2017 ... Barrel finishing (BF) process is widely used to improve the surface finish and dimensional features of metallic and ... plastic-based waste can be easily recycled. However .... The pattern prepared with solid density has a dense.

  10. Integration and installation of the CMS pixel barrel detector

    CERN Document Server

    Kastli, Hans-Christian

    2008-01-01

    A 66 million pixel detector has been installed in 2008 into the CMS experiment at CERN. The development and construction time took more than 10 years. In this paper the assembly of the barrel detector is described. A simple but effective method to accomplish a survey of the module positions during assembly is discussed. Furthermore the insertion and commissioning of the CMS pixel barrel detector which took place in July 2008 is illustrated.

  11. Sodium Dichromate Barrel Landfill expedited response action proposal

    International Nuclear Information System (INIS)

    1993-09-01

    The US Environmental Protection Agency (EPA) and Washington State Department of Ecology (Ecology) recommended that the US Department of Energy (DOE) prepare an expedited response action (ERA) for the Sodium Dichromate Barrel Landfill. The Sodium Dichromate Barrel Disposal Site was used in 1945 for disposal of crushed barrels. The site location is the sole waste site within the 100-IU-4 Operable Unit. The Waste Information Data System (WIDS 1992) assumes that the crushed barrels contained 1% residual sodium dichromate at burial time and that only buried crushed barrels are at the site. Burial depth is shallow since visual inspection finds numerous barrel debris on the surface. A non-time-critical ERA proposal includes preparation of an engineering evaluation and cost analysis (EE/CA) section. The EE/CA is a rapid, focused evaluation of available technologies using specific screening factors to assess feasibility, appropriateness, and cost. The ERA goal is to reduce the potential for any contaminant migration from the landfill to the soil column, groundwater, and Columbia River. Since the landfill is the only waste site within the operable unit, the ERA will present a final remediation of the 100-IU-4 operable unit

  12. The role of whiskers in compensation of visual deficit in a mouse model of retinal degeneration.

    Science.gov (United States)

    Voller, Jaroslav; Potužáková, Barbora; Šimeček, Vojtěch; Vožeh, František

    2014-01-13

    Sensory deprivation in one modality can enhance the development of the remaining modalities via mechanisms of synaptic plasticity. Mice of the C3H strain suffer from RD1 retinal degeneration that leads to visual impairment at weaning age. We examined a role of whiskers in compensation of the visual deficit. In order to differentiate the contribution of the whiskers from other mechanisms that can take part in the compensation, we investigated the effect of both chronic and acute tactile deprivation. Three-month-old mice were used. We examined motor skills (rotarod, beam walking test), gait control (CatWalk system), spontaneous motor activity (open field) and CNS excitability to an acoustic stimulus for assessment of compensatory changes in auditory system (audiogenic epilepsy). In the sighted mice, the only effect was a decline in their rotarod test performance after acute whisker removal. In the blind animals, chronic tactile deprivation caused changes in their gait and impaired the performance in motor tests. Some other compensatory mechanisms were involved but the whiskers are essential for the compensation as it emerged from more marked change of gait and the worsening of the motor performance after the acute whisker removal. Both chronic and acute tactile deprivation induced anxiety-like behaviour. Only a combination of blindness and chronic tactile deprivation led to an increased sense of hearing. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  13. Isolation of whiskers from natural sources and their dispersed in a non-aqueous medium

    Energy Technology Data Exchange (ETDEWEB)

    Vestena, Mauro; Gross, Idejan Padilha; Pires, Alfredo Tiburcio Nunes; Muller, Carmen Maria Olivera, E-mail: mauro@utfpr.edu.br [Universidade Federal Santa Catarina (UFSC), Florianopolis, SC (Brazil)

    2016-10-15

    Whiskers have been used as a nano material dispersed in polymer matrices to modify the microscopic and macroscopic properties of the polymer. These nanomaterials can be isolated from cellulose, one of the most abundant natural renewable sources of biodegradable polymer. In this study, whiskers were isolated from sugarcane bagasse and corn cob straw fibers. Initially, the cellulose fiber was treated through an alkaline/oxidative process followed by acid hydrolysis. Dimethylformamide and dimethyl sulfoxide were used to replace the aqueous medium for the dispersion of the whiskers. For the solvent exchange, dimethylformamide or dimethyl sulfoxide was added to the aqueous dispersion and the water was then removed by fractional distillation. FTIR, TGA, XRD, TEM, Zeta and DLS techniques were used to evaluate the efficiency of the isolation process as well as the morphology and dimensions of the whiskers. The dimensions of the whiskers are comparable with values reported in the literature, maintaining the uniformity and homogeneity in both aqueous and non-aqueous solvents. (author)

  14. Isolation of whiskers from natural sources and their dispersed in a non-aqueous medium

    Directory of Open Access Journals (Sweden)

    Mauro Vestena

    Full Text Available Abstract Whiskers have been used as a nanomaterial dispersed in polymer matrices to modify the microscopic and macroscopic properties of the polymer. These nanomaterials can be isolated from cellulose, one of the most abundant natural renewable sources of biodegradable polymer. In this study, whiskers were isolated from sugarcane bagasse and corn cob straw fibers. Initially, the cellulose fiber was treated through an alkaline/oxidative process followed by acid hydrolysis. Dimethylformamide and dimethyl sulfoxide were used to replace the aqueous medium for the dispersion of the whiskers. For the solvent exchange, dimethylformamide or dimethyl sulfoxide was added to the aqueous dispersion and the water was then removed by fractional distillation. FTIR, TGA, XRD, TEM, Zeta and DLS techniques were used to evaluate the efficiency of the isolation process as well as the morphology and dimensions of the whiskers. The dimensions of the whiskers are comparable with values reported in the literature, maintaining the uniformity and homogeneity in both aqueous and non-aqueous solvents.

  15. Preparation of mullite whiskers reinforced SiC/Al2O3 composites by microwave sintering

    Directory of Open Access Journals (Sweden)

    Wei Li

    2016-12-01

    Full Text Available Mullite whiskers reinforced SiC/Al2O3 composites were prepared by microwave sintering in a microwave chamber with TE666 resonant mode. Original SiC particles were coated with SiO2 using sol-gel processing and mixed with Al2O3 particles. Mullite was formed in the reaction between SiO2 and Al2O3. The isostatically pressed cylindrical pellets were sintered from 1350 °C to 1600 °C for 30 min. Physical and chemical responses were investigated by detecting changes in reflected power during the microwave sintering process. XRD was carried out to characterize the samples and showed that mullite could be formed at 1200 °C. Bridging of mullite whiskers between Al2O3 and SiC particles was observed by SEM and is due to a so-called local hot spot effect, which was the unique feature for microwave sintering. The optimized microwave sintering temperature was 1500 °C corresponding to the maximum amount of mullite whiskers within SiC/Al2O3 composites. The high electro-magnetic field enhanced the decomposition of mullite at higher temperatures above 1550 °C. The mechanical properties of mullite whiskers reinforced SiC/Al2O3 composites are much better than the SiC/Al2O3 composites without mullite whiskers.

  16. Peculiarities of magnetoresistance in InSb whiskers at cryogenic temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Druzhinin, A., E-mail: druzh@polynet.lviv.ua [Lviv Polytechnic National University, Bandera Str., 12, 79013 Lviv (Ukraine); International Laboratory of High Magnetic Fields and Low Temperatures, Gajowicka 95, Wroclaw (Poland); Ostrovskii, I.; Khoverko, Yu. [Lviv Polytechnic National University, Bandera Str., 12, 79013 Lviv (Ukraine); International Laboratory of High Magnetic Fields and Low Temperatures, Gajowicka 95, Wroclaw (Poland); Liakh-Kaguy, N.; Khytruk, I. [Lviv Polytechnic National University, Bandera Str., 12, 79013 Lviv (Ukraine); Rogacki, K. [International Laboratory of High Magnetic Fields and Low Temperatures, Gajowicka 95, Wroclaw (Poland)

    2015-12-15

    Highlights: • Magnetoresistance in InSb whiskers with impurity concentration near MIT is studied. • SdH oscillations of transverse and longitudinal magnetoresistance are examined. • Mechanisms of electron scattering are determined • Main crystal parameters of InSb whiskers are determined. - Abstract: The study of the magnetoresistance in InSb whiskers with an impurity concentration in the vicinity to the metal-insulator phase transition, at low temperature range 4.2–77 K, and in fields, with induction up to 14 T, was conducted. The presence of Shubnikov-de Haas oscillations in both transverse and longitudinal magnetoresistance was observed. The following parameters of InSb whiskers were defined: period of oscillations 0.1 T{sup −1}, cyclotron effective mass of electrons m{sub c} ≈ 0.14m{sub o,} concentration of charge carriers 2.3 × 10{sup 17} cm{sup −3}, g-factor g{sup *} ≈ 30 and Dingle temperature T{sub D} = 14.5 K. To determine the nature of crystal defects, the electron scattering processes on the short-range potential, caused by interaction with polar and nonpolar optical phonons, piezoelectric and acoustic phonons, static strain centers and ionized impurities in n-InSb whiskers, with defect concentration 2.9 × 10{sup 17} cm{sup −3}, are considered. The temperature dependences of electron mobility in the range 4.2–500 K were calculated.

  17. Microwave absorption behaviors of tetra-needle-like ZnO whiskers

    International Nuclear Information System (INIS)

    Zhou Zuowan; Chu Longsheng; Hu Shuchun

    2006-01-01

    A novel type of microwave absorption coating was prepared using tetra-needle-like zinc oxide whiskers as the main functional agent. The results of the experiments show that the composite coatings containing ZnO whisker appear to have good efficiency of microwave absorption, and the effect is influenced by the aspect ratio (length to diameter, L/D), the content of the T-ZnO whiskers and the resistivity of the whiskers. Microwave-heat transformation of this kind of whisker and its composite was investigated, and the results indicated that the apparent density affected the efficiency of the heat generating. The suitable value of the apparent density is 0.16-0.18 g/cm 3 . The mechanism of microwave absorption and microwave-heat transformation was explained by the semiconductive networks formed by the tetra-needle shape, diffuse reflections results from quasi-antenna, multipoles due to charge concentration and the multi-interfaces in the composites

  18. Solid-state synthesis of Li_4Ti_5O_1_2 whiskers from TiO_2-B

    International Nuclear Information System (INIS)

    Yao, Wenjun; Zhuang, Wei; Ji, Xiaoyan; Chen, Jingjing; Lu, Xiaohua; Wang, Changsong

    2016-01-01

    Highlights: • The Li_4Ti_5O_1_2 whiskers were synthesized from TiO_2-B whiskers via a solid state reaction. • The TiO_2-B crystal structure for lithium diffusion is easier than anatase. • The separated diffusion and reaction process is crucial for the solid-state syntheses of Li_4Ti_5O_1_2 whiskers. - Abstract: In this work, Li_4Ti_5O_1_2 (LTO) was synthesized from the precursors of TiO_2-B and anatase whiskers, respectively. The synthesized LTO whiskers from TiO_2-B whiskers via a solid state reaction at 650 °C have a high degree of crystallinity with an average diameter of 300 nm. However, when anatase whiskers were used as the precursor, only particle morphology LTO was produced at 750 °C. The further analysis of the precursors, the intermediate products and the final products reveal that the crystal structure of the anatase hinders the diffusion of lithium, leading to a typical reaction–diffusion process. Under this condition, only particle morphology LTO can be produced. However, the crystal structure of the TiO_2-B is easy for lithium diffusion and the process is performed in two separated steps (i.e., diffusion and reaction), which makes it possible to decrease the solid-state reaction temperature down to 650 °C and then maintain the morphologies of whiskers.

  19. Growth, characterization, and physical properties of Bi-Sr-Ca-Cu-O superconducting whiskers

    International Nuclear Information System (INIS)

    Kraak, W.; Thiele, P.

    1996-01-01

    Single crystal whiskers of the Bi-based high-T c superconductors have been grown directly from the stoichiometric melt. Conditions for the preferable growth of the (2212) phase and annealing conditions for the conversion from the (2212) phase to the (2223) and (2234) Bi-based superconducting phases are achieved. The orientation and chemical composition of the crystals were characterized by X-ray diffractometry and energy dispersive X-ray analysis. Characteristic structural properties of the whiskers (incommensurable modulation in b-direction, peculiarities of dislocation networks) have been revealed by transmission electron microscopy and electron diffraction. Some special features of the broad superconducting transition in multiphase whiskers have been examined by spatially resolved measurements using low-temperature scanning electron microscopy. (orig.)

  20. Stability to irradiation of SiGe whisker crystals used for sensors of physical values

    Directory of Open Access Journals (Sweden)

    Druzhinin A. A.

    2011-04-01

    Full Text Available An influence of g-irradiation (Co60 with doze up to 1—1018 сm–2 and magnetic field with induction up to 14 T on conduction of 1–xGex (х = 0,03 whisker crystals with resistivity of 0,08—0,025 Оhm·сm in temperature range 4,2—300 K have been studied. It is shown that whisker crystals resistance faintly varies under irradiation with doze 2·1017 сm–2, while their magnetoresistance substantially changes. The strain sensors stable to irradiation action operating in high magnetic fields on the base of the whiskers have been designed.

  1. Development of 9Al2O3{center_dot}2B2O3 whiskers reinforced piston by squeeze casting. Manufacturing process and characteristics of whiskers preform; Squeeze cast ho ni yoru 9Al2O3{center_dot}2B2O3 whisker kyoka piston no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Yamauchi, T; Suzuki, M; Takahashi, M; Takada, I; Toda, M [Suzuki Motor Co. Ltd., Shizuoka (Japan)

    1997-10-01

    The properties of 9Al2O3 {center_dot} 2B2O3 whisker reinforced aluminum alloy is excellent compared with conventional material at elevated temperatures. 9Al2O3 {center_dot} 2B2O3 whisker reinforced aluminum alloy was applied to the piston head of two cycle engines. This piston was produced by a squeeze casting process with the granulated whiskers preform which was infiltrated by a molten aluminum alloy under high pressure. Since the permeability of the granulated whiskers preform is larger than that of the uniform preform in which whiskers are distributed randomly and uniformly, it became possible to suppress the preform deformation using the developed preform. 7 refs., 8 figs., 2 tabs.

  2. The 'whisker sign' as an indicator of ochronosis in skeletal scintigraphy

    International Nuclear Information System (INIS)

    Paul, R.; Ylinen, S.L.

    1991-01-01

    A patient with alkaptonuria and ochronotic arthrosis was imaged twice with ( 99m Tc-DPD) - once during a bout of arthritic knee pain and once when symptom-free. There was a marked accumulation of radioactivity in the large joints. During the episode of arthritis the knee joints had a higher uptake than when the patient was without symptoms. The intervertebral discs showed a high uptake which extended laterally from the axial vertebral column; the finding gave an impression of whiskers, and this 'whisker sign' may be characteristic of ochronosis. (orig.)

  3. The 'whisker sign' as an indicator of ochronosis in skeletal scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Paul, R.; Ylinen, S.L. (Turku Univ. (Finland). Dept. of Nuclear Medicine)

    1991-03-01

    A patient with alkaptonuria and ochronotic arthrosis was imaged twice with ({sup 99m}Tc-DPD) - once during a bout of arthritic knee pain and once when symptom-free. There was a marked accumulation of radioactivity in the large joints. During the episode of arthritis the knee joints had a higher uptake than when the patient was without symptoms. The intervertebral discs showed a high uptake which extended laterally from the axial vertebral column; the finding gave an impression of whiskers, and this 'whisker sign' may be characteristic of ochronosis. (orig.).

  4. First two barrel ECAL supermodules inserted in CMS HCAL

    CERN Multimedia

    K.Bell

    2006-01-01

    The first two barrel "supermodules" for the CMS Electromagnetic Calorimeter (ECAL) have been inserted into the barrel hadron calorimeter (HCAL) in the experimental hall (called SX5) in Cessy in preparation for the forthcoming magnet test and cosmic challenge (MTCC). Each of the two supermodules contains 1700 lead tungstate crystals in glass-fibre alveolar support structures, with associated avalanche photodiodes (APDs, for scintillation light detection), electronics and cooling system. The barrel ECAL will consist of 36 supermodules, many of which have already been produced (see CERN Bulletin 17-18, 2006). Team from CMS ECAL, CMS Integration and CEA-DAPNIA were involved in the insertion, with the production/integration of the supermodules themselves involving many technicians, engineers and physicists from many institutes. From left to right: Olivier Teller, Maf Alidra and Lucien Veillet.

  5. Correcting the Chromatic Aberration in Barrel Distortion of Endoscopic Images

    Directory of Open Access Journals (Sweden)

    Y. M. Harry Ng

    2003-04-01

    Full Text Available Modern endoscopes offer physicians a wide-angle field of view (FOV for minimally invasive therapies. However, the high level of barrel distortion may prevent accurate perception of image. Fortunately, this kind of distortion may be corrected by digital image processing. In this paper we investigate the chromatic aberrations in the barrel distortion of endoscopic images. In the past, chromatic aberration in endoscopes is corrected by achromatic lenses or active lens control. In contrast, we take a computational approach by modifying the concept of image warping and the existing barrel distortion correction algorithm to tackle the chromatic aberration problem. In addition, an error function for the determination of the level of centroid coincidence is proposed. Simulation and experimental results confirm the effectiveness of our method.

  6. Mechanical Commissioning of the ATLAS Barrel Toroid Magnet

    CERN Document Server

    Foussat, A; Dudarev, A; Bajas, H; Védrine, P; Berriaud, C; Sun, Z; Sorbi, M

    2008-01-01

    ATLAS is a general-purpose detector designed to run at the highest luminosity at the CERN Large Hadron Collider. Its features include the 4 T Barrel Toroid magnet, the largest superconducting magnet (25 m long, 20 m diameter) that provides the magnetic field for the ATLAS muon spectrometer. The coils integrated at CERN, were tested individually at maximum current of 22 kA in 2005. Following the mechanical assembly of the Barrel Toroid in the ATLAS underground cavern, the test of the full Barrel Toroid was performed in October 2006. Further tests are foreseen at the end 2007 when the system will include the two End Cap Toroids (ECT). The paper gives an overview of the good mechanical test results achieved in comparison with model predictions and the experience gained in the mechanical behavior of the ATLAS Toroidal coils is discussed.

  7. Effect analysis of core barrel openings under CEFR normal condition

    International Nuclear Information System (INIS)

    Zhang Yabo; Yang Hongyi

    2008-01-01

    Openings on the bottom of core barrel are important part of the decay heat removal system of China Experimental Fast Reactor (CEFR), which are designed to discharge the decay heat from reactor under accident condition. This paper analyses the effect of the openings design on the normal operation condition using the famouse CFD code CFX. The result indicates that the decay heat can be discharged safely and at the same time the effect of core barrel openings on the normal operation condition is acceptable. (authors)

  8. LHC-rate beam test of CMS pixel barrel modules

    International Nuclear Information System (INIS)

    Erdmann, W.; Hoermann, Ch.; Kotlinski, D.; Horisberger, R.; Kaestli, H. Chr.; Gabathuler, K.; Bertl, W.; Meier, B.; Langenegger, U.; Trueeb, P.; Rohe, T.

    2007-01-01

    Modules for the CMS pixel barrel detector have been operated in a high rate pion beam at PSI in order to verify under LHC-like conditions the final module design for the production. The test beam provided charged particle rates up to 10 8 cm -2 s -1 over the full module area. Bunch structure and randomized high trigger rates simulated realistic operation. A four layer telescope made of single pixel readout chip assemblies provided tracking needed for the determination of the modules hit reconstruction efficiency. The performance of the modules has been shown to be adequate for the CMS pixel barrel

  9. Effect of carbon coating on spontaneous C12A7 whisker formation

    Science.gov (United States)

    Zaikovskii, Vladimir I.; Volodin, Alexander M.; Stoyanovskii, Vladimir O.; Cherepanova, Svetlana V.; Vedyagin, Aleksey A.

    2018-06-01

    A carbon nanoreactor concept was applied to study the stabilization effect of carbon shell on phase composition and morphology of dodecacalcium hepta-aluminate Ca12Al14O33. The starting C12A7 powder was obtained using aluminum and calcium hydroxides as precursors. Carbon shell was formed by a chemical vapor deposition of divinyl at 550 °C. After the calcination at 1400 °C, the product was characterized by X-ray diffraction analysis (XRD) and high resolution transmission electron microscopy (HRTEM). It was observed for a first time that spontaneous formation of calcium aluminate whiskers take place under the conditions described. Each whisker consists of a 'head' (globular particle of 0.5 microns in diameter) and a 'tail' (prolonged whisker of few microns in length and 0.1-0.2 microns in diameter). According to HRTEM, the 'head' is characterized with microcrystal lattice of Ca12Al14O33 compound. XRD data show the presence of CaAl2O4 phase traces. The 'head' and 'tail' of the whisker are covered with structured graphene layers of 10 nm and 3 nm, correspondingly.

  10. 3D printed biomimetic whisker-based sensor with co-planar capacitive sensing

    NARCIS (Netherlands)

    Delamare, John; Sanders, Remco G.P.; Krijnen, Gijsbertus J.M.

    2016-01-01

    This paper describes the development of a whisker sensor for tactile purposes and which is fabricated by 3D printing. Read-out consists of a capacitive measurement of a co-planar capacitance which is affected by a dielectric that is driven into the electric field of the capacitance. The current

  11. Estimating the Probability of Electrical Short Circuits from Tin Whiskers. Part 2

    Science.gov (United States)

    Courey, Karim J.; Asfour, Shihab S.; Onar, Arzu; Bayliss, Jon A.; Ludwig, Larry L.; Wright, Maria C.

    2010-01-01

    To comply with lead-free legislation, many manufacturers have converted from tin-lead to pure tin finishes of electronic components. However, pure tin finishes have a greater propensity to grow tin whiskers than tin-lead finishes. Since tin whiskers present an electrical short circuit hazard in electronic components, simulations have been developed to quantify the risk of said short circuits occurring. Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that had an unknown probability associated with it. Note however that due to contact resistance electrical shorts may not occur at lower voltage levels. In our first article we developed an empirical probability model for tin whisker shorting. In this paper, we develop a more comprehensive empirical model using a refined experiment with a larger sample size, in which we studied the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit. From the resulting data we estimated the probability distribution of an electrical short, as a function of voltage. In addition, the unexpected polycrystalline structure seen in the focused ion beam (FIB) cross section in the first experiment was confirmed in this experiment using transmission electron microscopy (TEM). The FIB was also used to cross section two card guides to facilitate the measurement of the grain size of each card guide's tin plating to determine its finish .

  12. Analysis of the collar-whisker structure of temperate lactococcal bacteriophage TP901-1

    DEFF Research Database (Denmark)

    Vegge, Christina Skovgaard; Neve, Horst; Brøndsted, Lone

    2006-01-01

    Proteins homologous to the protein NPS (neck passage structure) are widespread among lactococcal phages. We investigated the hypothesis that NPS is involved in the infection of phage TP901-1 by analysis of an NPS mutant. NPS was determined to form a collar-whisker complex but was shown to be none...

  13. In vitro formation of the Merkel cell-neurite complex in embryonic mouse whiskers using organotypic co-cultures.

    Science.gov (United States)

    Ishida, Kentaro; Saito, Tetsuichiro; Mitsui, Toshiyuki

    2018-06-01

    A Merkel cell-neurite complex is a touch receptor composed of specialized epithelial cells named Merkel cells and peripheral sensory nerves in the skin. Merkel cells are found in touch-sensitive skin components including whisker follicles. The nerve fibers that innervate Merkel cells of a whisker follicle extend from the maxillary branch of the trigeminal ganglion. Whiskers as a sensory organ attribute to the complicated architecture of the Merkel cell-neurite complex, and therefore it is intriguing how the structure is formed. However, observing the dynamic process of the formation of a Merkel cell-neurite complex in whiskers during embryonic development is still difficult. In this study, we tried to develop an organotypic co-culture method of a whisker pad and a trigeminal ganglion explant to form the Merkel cell-neurite complex in vitro. We initially developed two distinct culture methods of a single whisker row and a trigeminal ganglion explant, and then combined them. By dissecting and cultivating a single row from a whisker pad, the morphogenesis of whisker follicles could be observed under a microscope. After the co-cultivation of the whisker row with a trigeminal ganglion explant, a Merkel cell-neurite complex composed of Merkel cells, which were positive for both cytokeratin 8 and SOX2, Neurofilament-H-positive trigeminal nerve fibers and Schwann cells expressing Nestin, SOX2 and SOX10 was observed via immunohistochemical analyses. These results suggest that the process for the formation of a Merkel cell-neurite complex can be observed under a microscope using our organotypic co-culture method. © 2018 Japanese Society of Developmental Biologists.

  14. High-temperature deformation of SiC-whisker-reinforced MgO-PSZ/mullite composites

    International Nuclear Information System (INIS)

    Parthasarathy, T.A.; Hay, R.S.; Ruh, R.

    1996-01-01

    The effect of 33.5 vol% SiC whisker loading on high-temperature deformation of 1 wt% MgO-38.5 wt% zirconia-mullite composites was studied between 1,300 and 1,400 C. At strain rates of 10 -6 to 5 x 10 -4 /s the creep resistance of zirconia-mullite composites without SiC reinforcement was inferior to monolithic mullite of similar grain size. Analysis of the results suggested that the decreased creep resistance of mullite-zirconia composites compared to pure mullite could be at least partially explained by mechanical effects of the weaker zirconia phase, increased effective diffusivity of mullite by zirconia addition, and to the differences in mullite grain morphology. With SiC whisker reinforcement, the deformation rate at high stress was nearly the same as that of the unreinforced material, but at low stress the creep rates of the SiC-reinforced material were significantly lowered. The stress dependence of the creep rate of unreinforced material suggested that diffusional creep was the operative mechanism, while the reinforced material behaved as if a threshold stress for creep existed. The threshold stress could be rationalized based on a whisker network model. This was supported by data on other whisker-containing materials; however, the threshold stress had a temperature dependence that was orders of magnitude higher than the elastic constants, leaving the physical model incomplete. The effects of residual stresses and amorphous phases at whisker/matrix interfaces are invoked to help complete the physical model for creep threshold stress

  15. End of the EM Barrel Presampler Construction and Insertion

    CERN Multimedia

    Hostachy, J.Y.

    The liquid argon barrel presampler is a thin detector placed in front of the electromagnetic barrel calorimeter, made up of two half barrels also, but with 32 sectors per half barrel instead of 16. Each of these 64 sectors is 3.1 m long, 28 cm large and 2.9 cm thick. Three countries took part in its construction: France (LPSC-Grenoble), Sweden (KTH-Stockholm) and Morocco (Hassan II Ain Chock-Casablanca and Mohamed V-Rabat universities, and CNESTEN-Rabat). The design of the presampler started 11 years ago and the series production began at the end of 2000. Cabling, mechanical and electronic tests of the anodes were achieved in Morocco. Forty-one sectors were assembled and validated at the LPSC-Grenoble and 25 at the KTH-Stockholm. In November 2002, the first half was inserted on the inner face of the first EM calorimeter wheel. The insertion of the other 32 sectors in the second EM calorimeter wheel was achieved in July 2003 (see pictures). The production of two additional sectors will allow us to study the p...

  16. barrel temperature emperature emperature effects on the ffects

    African Journals Online (AJOL)

    eobe

    Keywords: barrel temperature,plastic products, injection moulding machine , tensile strength, flexual strength. 1. INTRODUCTION. INTRODUCTION. INTRODUCTION. The utilization of process control and process monitoring are rarely fully implemented for the production of injection moulded products. This may be due to a ...

  17. Results of 3D photogrammetry on the CMS barrel yoke

    International Nuclear Information System (INIS)

    Goudard, R.; Humbertclaude, C.; Nummiaro, K.

    1999-01-01

    The CMS (Compact Muon Solenoid) detector of the new LHC will be built till 2005 at CERN in Geneva. The Barrel Yoke survey has been decided to be done mostly by photogrammetry. After this first measurement, it has been proved that a practical simulation and a study of adapted tools and procedures were helpful for measurement on such a large object. Using only conventional surveying methods would have been impossible with such constraints. The most important points were the high required accuracy compared to the size of the object, the connection of the two planes, the time intervention, the restricted factory environment and the impossibility for having any outside network. The photogrammetric method was considered to be the best way to survey the Barrel Yoke ring. Since the required precision has been reached at all levels with the first full Barrel measurements, the procedure is validated for the four remaining Barrels in the factory and afterwards again at CERN. This project was challenging due to the size of the object, the required accuracy and the lack of practical references in the field of digital industrial photogrammetry. This method is a new step for using the three dimensional photogrammetric measurements on large objects. (authors)

  18. ATLAS barrel hadron tile calorimeter: spacers plates mass production

    International Nuclear Information System (INIS)

    Artikov, A.M.; Budagov, Yu.A.; Khubua, J.

    1999-01-01

    In this article we expose the main problems of the mass production of the so-called 'spacer plates' for the ATLAS Barrel Hadron Tile Calorimeter. We describe all practical solutions of these problems. Particularly we present the measurement procedures and calculation schemes we used for the spacers dimensions determination. The results of the calculations are presented

  19. Experiences developing socially acceptable interactions for a robotic trash barrel

    DEFF Research Database (Denmark)

    Yang, Stephen; Mok, Brian Ka Jun; Sirkin, David

    2015-01-01

    strategies that seemed to evoke clear engagement and responses, both positive and negative. Observations and interviews show that a) people most welcome the robot's presence when they need its services and it actively advertises its intent through movement; b) people create mental models of the trash barrel...

  20. The barrel modules of the ATLAS semiconductor tracker

    Czech Academy of Sciences Publication Activity Database

    Abdesselam, A.; Akimoto, T.; Allport, P.; Böhm, Jan; Šťastný, Jan

    2006-01-01

    Roč. 568, - (2006), s. 642-671 ISSN 0168-9002 Institutional research plan: CEZ:AV0Z10100502 Keywords : ATLAS * SCT * silicon * microstrip * module * LHC * barrel Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.185, year: 2006

  1. New results in meson spectroscopy from the crystal barrel experiment

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, C.A. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    1994-04-01

    Recent observations by the Crystal Barrel experiment of two scalar resonances, f{sub o}(1365) and a{sub o}(1450) have allowed the authors to clarify the members of the scalar nonet. In addition, a third scalar, f{sub o}(1500), appears to be supernumerary, and is a candidate for the scalar glueball expected near 1500 MeV.

  2. Monitoring of the ageing of the DELPHI Barrel RICH MWPCs

    International Nuclear Information System (INIS)

    Apeldoorn, G.; Buys, A.; Dracos, M.; Toet, D.Z.

    1996-01-01

    We describe a method to monitor ageing effects in the multiwire proportional chambers (MWPCs) of the barrel ring imaging Cherenkov (BRICH) detector of DELPHI. It is based on a measurement of plateau-curve characteristics and the shift of these as a function of the total collected charge. Results indicate that, as yet, no ageing effects are present. (orig.)

  3. Fabrication and properties of aluminum silicate fibrous materials with in situ synthesized K2Ti6O13 whiskers

    Science.gov (United States)

    Liu, Hao; Wei, Nan; Wang, Zhou-fu; Wang, Xi-tang; Ma, Yan

    2017-11-01

    To improve their mechanical and thermal insulation properties, aluminum silicate fibrous materials with in situ synthesized K2Ti6O13 whiskers were prepared by firing a mixture of short aluminum silicate fibers and gel powders obtained from a sol-gel process. During the preparation process, the fiber surface was coated with K2Ti6O13 whiskers after the fibers were subjected to a heat treatment carried out at various temperatures. The effects of process parameters on the microstructure, compressive strength, and thermal conductivity were analyzed systematically. The results show that higher treatment temperatures and longer treatment durations promoted the development of K2Ti6O13 whiskers on the surface of aluminum silicate fibers; in addition, the intersection structure between whiskers modulated the morphology and volume of the multi-aperture structure among fibers, substantially increasing the fibers' compressive strength and reducing their heat conduction and convective heat transfer at high temperatures.

  4. The integration and engineering of the ATLAS SemiConductor Tracker Barrel

    Energy Technology Data Exchange (ETDEWEB)

    Abdesselam, A; Barr, A J [Department of Physics, Oxford University, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Allport, P P; Austin, N [Oliver Lodge Laboratory, University of Liverpool, P.O. Box 147, Oxford Street, Liverpool L69 3BX (United Kingdom); Anastopoulos, C [University of Sheffield, Department of Physics and Astronomy, Hounsfield Road, Sheffield S3 7RH (United Kingdom); Anderson, B; Attree, D J [Department of Physics and Astronomy, University College London (United Kingdom); Andricek, L; Bangert, A [Max-Planck-Institut fuer Physik, (Werner-Heisenberg-Institut), Foehringer Ring 6, 80805 Muenchen (Germany); Anghinolfi, F [CERN, CH - 1211 Geneva 23 (Switzerland); Apsimon, R; Barclay, P; Batchelor, L E [Rutherford Appleton Laboratory, Science and Technology Facilities Council, Harwell Science and Innovation Campus, Didcot OX11 0QX (United Kingdom); Atkinson, T [School of Physics, University of Melbourne, Parkville, Victoria 3010 (Australia); Barbier, G [Universite de Geneve, Section de Physique, 24 rue Ernest Ansermet, CH - 1211 Geneve 4 (Switzerland); Bates, R L; Bell, W H [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Batley, J R [Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Beck, G A [Department of Physics, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom); Bell, P J [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom)] (and others)

    2008-10-15

    The ATLAS SemiConductor Tracker (SCT) was built in three sections: a barrel and two end-caps. This paper describes the design, construction and final integration of the barrel section. The barrel is constructed around four nested cylinders that provide a stable and accurate support structure for the 2112 silicon modules and their associated services. The emphasis of this paper is directed at the aspects of engineering design that turned a concept into a fully-functioning detector, as well as the integration and testing of large sub-sections of the final SCT barrel detector. The paper follows the chronology of the construction. The main steps of the assembly are described with the results of intermediate tests. The barrel service components were developed and fabricated in parallel so that a flow of detector modules, cooling loops, opto-harnesses and Frequency-Scanning-Interferometry (FSI) alignment structures could be assembled onto the four cylinders. Once finished, each cylinder was conveyed to the next site for the mounting of modules to form a complete single barrel. Extensive electrical and thermal function tests were carried out on the completed single barrels. In the next stage, the four single barrels and thermal enclosures were combined into the complete SCT barrel detector so that it could be integrated with the Transition Radiation Tracker (TRT) barrel to form the central part of the ATLAS inner detector. Finally, the completed SCT barrel was tested together with the TRT barrel in noise tests and using cosmic rays.

  5. Magnetic whiskers of p-aminobenzoic acid and their use for preparation of filled and microchannel silicone rubbers

    International Nuclear Information System (INIS)

    Semenov, V. V.; Loginova, V. V.; Zolotareva, N. V.; Razov, E. N.; Kotomina, V. E.; Kruglov, A. V.

    2016-01-01

    A thin cobalt layer has been formed on the surface of p-aminobenzoic acid whiskers by chemical vapor deposition (CVD). The metallized crystals have been oriented in liquid polydimethylsiloxane rubber by applying a dc magnetic field. After vulcanization, the filler has been removed by processing in an alcohol solution of trifluoroacetic acid. The cobalt deposition on the surface of the organic compound and the properties of metallized whiskers are investigated by optical microscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM).

  6. Magnetic whiskers of p-aminobenzoic acid and their use for preparation of filled and microchannel silicone rubbers

    Energy Technology Data Exchange (ETDEWEB)

    Semenov, V. V., E-mail: vvsemenov@iomc.ras.ru; Loginova, V. V.; Zolotareva, N. V. [Russian Academy of Sciences, Razuvaev Institute of Organometallic Chemistry (Russian Federation); Razov, E. N. [Lobachevsky Nizhny Novgorod State University (Russian Federation); Kotomina, V. E.; Kruglov, A. V. [Lobachevsky Nizhny Novgorod State University, Physical‒Technical Research Institute (Russian Federation)

    2016-07-15

    A thin cobalt layer has been formed on the surface of p-aminobenzoic acid whiskers by chemical vapor deposition (CVD). The metallized crystals have been oriented in liquid polydimethylsiloxane rubber by applying a dc magnetic field. After vulcanization, the filler has been removed by processing in an alcohol solution of trifluoroacetic acid. The cobalt deposition on the surface of the organic compound and the properties of metallized whiskers are investigated by optical microscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM).

  7. Neonatal Whisker Trimming Impairs Fear/Anxiety-Related Emotional Systems of the Amygdala and Social Behaviors in Adult Mice.

    Directory of Open Access Journals (Sweden)

    Hitomi Soumiya

    Full Text Available Abnormalities in tactile perception, such as sensory defensiveness, are common features in autism spectrum disorder (ASD. While not a diagnostic criterion for ASD, deficits in tactile perception contribute to the observed lack of social communication skills. However, the influence of tactile perception deficits on the development of social behaviors remains uncertain, as do the effects on neuronal circuits related to the emotional regulation of social interactions. In neonatal rodents, whiskers are the most important tactile apparatus, so bilateral whisker trimming is used as a model of early tactile deprivation. To address the influence of tactile deprivation on adult behavior, we performed bilateral whisker trimming in mice for 10 days after birth (BWT10 mice and examined social behaviors, tactile discrimination, and c-Fos expression, a marker of neural activation, in adults after full whisker regrowth. Adult BWT10 mice exhibited significantly shorter crossable distances in the gap-crossing test than age-matched controls, indicating persistent deficits in whisker-dependent tactile perception. In contrast to controls, BWT10 mice exhibited no preference for the social compartment containing a conspecific in the three-chamber test. Furthermore, the development of amygdala circuitry was severely affected in BWT10 mice. Based on the c-Fos expression pattern, hyperactivity was found in BWT10 amygdala circuits for processing fear/anxiety-related responses to height stress but not in circuits for processing reward stimuli during whisker-dependent cued learning. These results demonstrate that neonatal whisker trimming and concomitant whisker-dependent tactile discrimination impairment severely disturbs the development of amygdala-dependent emotional regulation.

  8. Electrochemical preparation of Al–Sm intermetallic compound whisker in LiCl–KCl Eutectic Melts

    International Nuclear Information System (INIS)

    Ji, De−Bin; Yan, Yong−De; Zhang, Mi−Lin; Li, Xing; Jing, Xiao−Yan; Han, Wei; Xue, Yun; Zhang, Zhi−Jian; Hartmann, Thomas

    2015-01-01

    Highlights: • The reduction process of Sm(III) was investigated in LiCl–KCl melt on an aluminum electrode at 773 K. • Al–Sm alloy with different phase structure (Al 2 Sm and Al 3 Sm) was prepared by potentiostatic electrolysis on an aluminum electrode with the change of electrolytic potentials and time in LiCl–KCl–SmCl 3 melts. • Al − Sm alloy containing whiskers (Al 4 Sm) was obtained by potentiostatic electrolysis (−2.10 V) on an aluminum electrode for 7 hours with the change of electrolytic temperature and cooling rate in LiCl–KCl–SmCl 3 (16.5 wt. %) melts. The results from micro–hardness test and potentiodynamic polarization test show the micro hardness and corrosion property are remarkably improved with the help of Al–Sm intermetallic compound whiskers. - Abstract: This work presents the electrochemical study of Sm(III) on an aluminum electrode in LiCl–KCl melts at 773 K by different electrochemical methods. Three electrochemical signals in cyclic voltammetry, square wave voltammetry, open circuit chronopotentiometry, and cathode polarization curve are attributed to different kinds of Al–Sm intermetallic compounds, Al 2 Sm, Al 3 Sm, and Al 4 Sm, respectively. Al–Sm alloy with different phase structure (Al 2 Sm and Al 3 Sm) could be obtained by the potentiostatic electrolysis with the change of electrolytic potentials and time. Al–Sm alloy containing whiskers (Al 4 Sm) was obtained by potentiostatic electrolysis (−2.10 V) on an aluminum electrode for 7 hours with the change of electrolytic temperature and cooling rate in LiCl–KCl–SmCl 3 (16.5 wt. %) melts. The XRD and SEM&EDS were employed to investigate the phase composition and microstructure of Al–Sm alloy. SEM analysis shows that lots of needle−like precipitates formed in Al–Sm alloy, and their ratios of length to diameter are found to be greater than 10 to 1. The TEM and electron diffraction pattern were performed to investigate the crystal structure of the

  9. ATLAS barrel toroid integration and test area in building 180

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    The ATLAS barrel toroid system consists of eight coils, each of axial length 25.3 m, assembled radially and symmetrically around the beam axis. The coils are of a flat racetrack type with two 'double-pancake' windings made of 20.5 kA aluminium-stabilized niobium-titanium superconductor. The barrel toroid is being assembled in building 180 on the Meyrin site. In the first phase of assembly, the coils are packed into their aluminium-alloy casing. These photos show the double-pancake coils from ANSALDO and the coil casings from ALSTOM. In the foreground is the tooling from COSMI used to turn over the coil casings during this first phase. In the right background is the yellow lifting gantry manufactured at JINR-Dubna, Russia which will transport the coil casings to a heating table for prestressing. Two test benches with magnetic mirror are also visible.

  10. The bar PANDA Barrel-TOF Detector at FAIR

    Science.gov (United States)

    Zimmermann, S.; Suzuki, K.; Steinschaden, D.; Chirita, M.; Ahmed, G.; Dutta, K.; Kalita, K.; Lehmann, A.; Böhm, M.; Schwarz, K.; Orth, H.; Brinkmann, K.-Th.

    2017-08-01

    The barrel-Time-of-Flight subdetector is one of the outer layers of the multi-layer design of the \\panda target spectrometer. It is designed with a minimal material budget in mind mainly consisting of 90×30×5 mm3 thin plastic scintillator tiles read out on each end by a serial connection of 4 SiPMs. 120 such tiles are placed on 16 2460 × 180 mm2 PCB boards forming a barrel covering an azimuthal angle from 22.5o to 150o. The detector is designed to achieve a time resolution below σ< 100 ps which allows to distinguish events in the constant stream of hits, as well as particle identification below the Cherenkov threshold via the time-of-flight; simultaneously providing the interaction times of events. The current prototype achieved a time resolution of ~54 ps, well below the design goal.

  11. Simulgeo and its application for the muon barrel position monitor

    International Nuclear Information System (INIS)

    Brunel, L.

    1999-01-01

    The design process of the Muon Barrel Position Monitor of the CMS (compact muon solenoid) experiment for LHC is at the origin of the need of a software like Simulgeo. The software Silmugeo started to be developed in 1995 in order to allow the study of many systems. The idea of Simulgeo is to automatically make the modelling of a system and automatically construct the design matrix. This paper makes in part 2 an overview of the possibilities of Simulgeo, in part 3 it presents the standard objects. In part 4, it explains the mathematical basis and in part 5 the computing aspect. In part 6, it shows an application to the Muon Barrel Position Monitor Project and, in part 7, it mentions other projects where it has been used

  12. Design of the LHC US ATLAS Barrel Cryostat

    CERN Document Server

    Rehak, M L; Farah, Y; Grandinetti, R; Müller, T; Norton, S; Sondericker, J

    2002-01-01

    One of the experiments of CERN's Large Hadron Collider (LHC) is the ATLAS Liquid Argon detector. The Liquid Argon Barrel Cryostat is part of the United States contribution to the LHC project and its design is presented here. The device is made up of four concentric cylinders: the smallest and largest of which form a vacuum vessel enclosing a cold vessel cryostat filled with liquid argon. The Cryostat serves as the housing for an electromagnetic barrel calorimeter, supports and provides space in vacuum for a solenoid magnet while the toroidal opening furnishes room for a tracker detector. Design requirements are determined by its use in a collider experiment: the construction has to be compact, the material between the interaction region and the calorimeter has to be minimal and made of aluminum to reduce the amount of absorbing material. The design complies with code regulations while being optimized for its use in a physics environment. (2 refs).

  13. Fabrication and characterization of intrinsic Josephson junctions in RE-123 whiskers

    International Nuclear Information System (INIS)

    Okutsu, T.; Ueda, S.; Ishii, S.; Nagasawa, M.; Takano, Y.

    2008-01-01

    The series of REBa 2 Cu 3 O 7-δ RE-123; RE = Y, Eu, Gd, Dy, Ho, Er, Tm, and Lu) single-crystal whiskers have been successfully grown using the Te- or Sb-doping method. Intrinsic Josephson junctions (IJJs) were fabricated from the whiskers using a focused ion beam (FIB). As-grown IJJs with T c > 70 K showed a Josephson current but no multi-branches in the current-voltage (I-V) characteristics. Under-doped specimens were obtained by a post-annealing process. As-grown IJJs with lower T c and all the specimens of the post-annealed IJJs showed clear multi-branched structure. The post-annealing reduced the critical temperature (T c ) and the critical current density (J c ) of the IJJs, and increased the anisotropic parameter γ

  14. Galvano-magnetic properties and Shubnikov de Haas effect of Te-whiskers

    International Nuclear Information System (INIS)

    Berezovets, Veacheslav; Bondarchuk, Nikolai; Nikolaeva, Albina; Nijankovskii, Victor

    2009-01-01

    The work is devoted to investigation of the peculiarities of magnetoresistance, Hall effect and Shubnikov de Haas oscillations in Te-whiskers. Te-whiskers was prepared from vapor-gas phase on the substrate pure tellurium and grown naturally, of the walls of a crucible in the course of growing Te single crystals by the Czochralski method . The measurements of the galvanomagnetic properties and Shubnikov de Haas oscillation correspond to the notion of the occurrence of the effect of intraband magnetic breakdown when two different quasi-classical cyclotron trajectories coexist simultaneously in a magnetic field. This effect is a consequence of the presence of the saddle point in the dispersion law of the tellurium valence band. (authors)

  15. Poly(Butylene Terephthalate Based Composites Containing Alumina Whiskers: Influence of Filler Functionalization on Dielectric Properties

    Directory of Open Access Journals (Sweden)

    Pietro Russo

    2014-01-01

    Full Text Available Poly(butylene terephthalate (PBT is one of the most widely used semicrystalline thermoplastics polyester because of its superior thermal and mechanical properties, high dimensional stability and excellent processability. In this research PBT-based nanocomposites, including various amounts (up to 10 wt% of commercial alumina whiskers, have been prepared by using a Brabender internal chamber mixer and analysed in terms of morphological features and dielectric properties. Specific attention has been focused on the effect of the filler functionalization considering 3-glycidoxy propylmethoxysilane (GPS or 3-methacryloxypropyltrimethoxysilane (MPS as coupling agents. Tests, performed on compounds filled with neat and functionalized alumina whiskers, show a clear dependence of relative dielectric permittivity εr, invariance of dissipation factor (tgδ, and a sensible increase of volume electrical resistivity (ρv with the filler’s content and are encouraging for a future introduction of such composites in many electrical applications.

  16. Signal feedthroughs for the ATLAS barrel and endcap calorimeters

    International Nuclear Information System (INIS)

    Axen, D.; Hackenburg, R.; Hoffmann, A.; Kane, S.; Lissauer, D.; Makowiecki, D.; Muller, T.; Pate, D.; Radeka, V.; Rahm, D.; Rehak, M.; Rescia, S.; Sexton, K.; Sondericker, J.; Birney, P.; Dowling, A.W.; Fincke-Keeler, M.; Hodges, T.; Holness, F.; Honkanen, N.

    2005-01-01

    The function, design, construction, testing, and installation of the signal feedthroughs for the barrel and endcap ATLAS liquid argon calorimeters are described. The feedthroughs provide a high density and radiation hard method to extract over 200 000 signals from the cryogenic environment of the calorimeters using an application of a design based on flexible kapton circuit board transmission lines. A model to describe the frequency dependent behavior of the transmission lines is also presented

  17. Reversible man-in-the-barrel syndrome in myasthenia gravis

    OpenAIRE

    Shah, Poornima A; Wadia, Pettarusp Murzban

    2016-01-01

    Man-in-the-barrel syndrome (MBS) is an uncommon presentation due to bilateral, predominantly proximal muscle weakness that has not been described to be associated with myasthenia gravis. We describe a case of myasthenia gravis presenting as MBS. Additionally, he had significant wasting of the deltoids bilaterally with fibrillations on electromyography (EMG) at rest and brief duration (3-6 ms) bi/triphasic motor unit potentials (MUPs) on submaximal effort apart from a decremental response on r...

  18. Device for cementing radioactive of toxic waste into barrels

    International Nuclear Information System (INIS)

    Hempelmann, W.; Waldenmeier, G.; Mathis, P.; Mathis, B.; Mathis, F.

    1987-01-01

    The plant consists of conventional means, such as through mixers and dosing and transport spirals, which are accommodated in a glovebox. The inactive additives cement and sand and the active materials evaporation concentrates and sludges are mixed by them, and are then filled into a waste barrel which is empty or already filled with solid waste. Liquid radioactive wastes are used to concrete over the solid waste. (DG) [de

  19. Design and construction of the ZEUS barrel calorimeter

    International Nuclear Information System (INIS)

    Repond, J.

    1990-01-01

    The mechanical design and construction techniques of the barrel calorimeter for the ZEUS detector are presented. The calorimeter uses alternate layers of depleted uranium and scintillator with one radiation length sampling. The unit cell has e/h = 1 which yields an optimal energy resolution for hadronic jets. We discuss the placing of the structural components and cracks between modules. Details of the construction and assembly effort needed to realize the total calorimeter are reported. 4 figs., 1 tab

  20. Mechanical structure of the TOPAZ barrel drift chamber

    International Nuclear Information System (INIS)

    Morimoto, T.; Maruyama, K.; Okuno, H.

    1987-07-01

    A Barrel Drift Chamber (BDC) is constructed for the TOPAZ experiment at TRISTAN, KEK. The BDC has a cylindrical shape with dimensions of 325.2 cm in inner diameter, 347.2 cm in outer diameter and 500 cm long. It consists of 1232 drift tubes made of conductive plastic cathodes, which are staggered in four layers. In this report, a design of the mechanical structure and construction procedures are described in detail. (author)

  1. Non-compensation of the ATLAS barrel combined calorimeter prototype

    International Nuclear Information System (INIS)

    Kul'chitskij, Yu.A.; Kuz'min, M.V.

    1998-01-01

    The e / π ratio for the ATLAS Barrel Combined Calorimeter Prototype, composed from electromagnetic LArg calorimeter and hadronic Tile calorimeter was investigated. Response of Combined Calorimeter on pions and electrons in the energy region of 20-300 GeV was studied. Found e / h = 1.37 ± 0.01 ± 0.02 is in good agreement with the results from previous Combined Calorimeter tests but has more precisions

  2. Whisker growth: a new mechanism for helium blistering of surfaces in complex radiation environments

    International Nuclear Information System (INIS)

    McDonell, W.R.

    1978-01-01

    Implantation of helium concurrent with the generation of large numbers of displaced atoms in surface layers of materials exposed to 252 Cf α-particles and fission fragments produces a unique form of low temperature surface blistering. The purpose of this paper is to formulate a basis for the whisker-growth mechanism for helium blistering as an aid to the specification of conditions under which the mechanism might apply

  3. Effect of SiC whisker addition on the microstructures and mechanical properties of Ti(C, N)-based cermets

    International Nuclear Information System (INIS)

    Wu, Peng; Zheng, Yong; Zhao, Yongle; Yu, Haizhou

    2011-01-01

    Ti(C, N)-based cermets with addition of SiC whisker (SiC w ) were prepared by vacuum sintering. The microstructures of the prepared cermets were investigated by using X-ray diffractometry (XRD) and scanning electron microscopy (SEM). Mechanical properties such as transverse rupture strength (TRS), fracture toughness (K IC ) and hardness (HRA) were also measured. It was found that the grain size of the cermets was affected by the SiC whisker addition. The cermets with 1.0 wt.% SiC whisker addition exhibited the smallest grain size. The porosities of the cermets increased with increasing SiC whisker additions. The addition of the SiC whisker had no influence on the phase constituents of the cermets. Compared with the cermets with no whisker addition, the highest TRS and fracture toughness for cermets with 1.0 wt.% SiC whisker addition increased by about 24% and 29%, respectively. The strengthening mechanisms were attributed to finer grain size, homogeneous microstructure and moderate thickness of rim phase. The toughening mechanisms were characterized by crack deflection, whisker bridging and whisker pulling-out.

  4. Optical properties of the PANDA barrel DIRC radiator bars

    Energy Technology Data Exchange (ETDEWEB)

    Kalicy, Grzegorz; Krebs, Marvin; Peters, Klaus [GSI, Darmstadt (Germany); Goethe Universitaet, Frankfurt (Germany); Schwarz, Carsten; Schwiening, Jochen [GSI, Darmstadt (Germany); Collaboration: PANDA-Collaboration

    2015-07-01

    The PANDA experiment at the Facility for Antiproton and Ion Research in Europe (FAIR) at GSI, Darmstadt, will study fundamental questions of hadron physics and QCD. A fast focusing DIRC (Detection of Internally Reflected Cherenkov light) counter will provide hadronic particle identification (PID) in the barrel region of the PANDA detector. To meet the PID requirements, the Barrel DIRC has to provide precise measurements of the Cherenkov angle, which is conserved for Cherenkov photons propagating through the radiator by total internal reflection. The radiators, rectangular bars made from fused silica, have to fulfill very strict optical and mechanical requirements. This includes the squareness and parallelism of the sides of the bars, sharp corners, and a very smooth surface polish, ensuring that the Cherenkov photons reach the optical sensors without angular distortions. Currently the Barrel DIRC is at the final design stage and several different bar shapes and fabrication methods are being considered for the final detector. An optical setup, consisting of a computer-controlled positioning and a multi-wavelength laser system, is used to evaluate the radiator bars to obtain critical values like transmittance and reflectivity. The current results and techniques are presented on this poster.

  5. Motion makes sense: an adaptive motor-sensory strategy underlies the perception of object location in rats.

    Science.gov (United States)

    Saraf-Sinik, Inbar; Assa, Eldad; Ahissar, Ehud

    2015-06-10

    Tactile perception is obtained by coordinated motor-sensory processes. We studied the processes underlying the perception of object location in freely moving rats. We trained rats to identify the relative location of two vertical poles placed in front of them and measured at high resolution the motor and sensory variables (19 and 2 variables, respectively) associated with this whiskers-based perceptual process. We found that the rats developed stereotypic head and whisker movements to solve this task, in a manner that can be described by several distinct behavioral phases. During two of these phases, the rats' whiskers coded object position by first temporal and then angular coding schemes. We then introduced wind (in two opposite directions) and remeasured their perceptual performance and motor-sensory variables. Our rats continued to perceive object location in a consistent manner under wind perturbations while maintaining all behavioral phases and relatively constant sensory coding. Constant sensory coding was achieved by keeping one group of motor variables (the "controlled variables") constant, despite the perturbing wind, at the cost of strongly modulating another group of motor variables (the "modulated variables"). The controlled variables included coding-relevant variables, such as head azimuth and whisker velocity. These results indicate that consistent perception of location in the rat is obtained actively, via a selective control of perception-relevant motor variables. Copyright © 2015 the authors 0270-6474/15/358777-13$15.00/0.

  6. Optogenetic probing of nerve and muscle function after facial nerve lesion in the mouse whisker system

    Science.gov (United States)

    Bandi, Akhil; Vajtay, Thomas J.; Upadhyay, Aman; Yiantsos, S. Olga; Lee, Christian R.; Margolis, David J.

    2018-02-01

    Optogenetic modulation of neural circuits has opened new avenues into neuroscience research, allowing the control of cellular activity of genetically specified cell types. Optogenetics is still underdeveloped in the peripheral nervous system, yet there are many applications related to sensorimotor function, pain and nerve injury that would be of great benefit. We recently established a method for non-invasive, transdermal optogenetic stimulation of the facial muscles that control whisker movements in mice (Park et al., 2016, eLife, e14140)1. Here we present results comparing the effects of optogenetic stimulation of whisker movements in mice that express channelrhodopsin-2 (ChR2) selectively in either the facial motor nerve (ChAT-ChR2 mice) or muscle (Emx1-ChR2 or ACTA1-ChR2 mice). We tracked changes in nerve and muscle function before and up to 14 days after nerve transection. Optogenetic 460 nm transdermal stimulation of the distal cut nerve showed that nerve degeneration progresses rapidly over 24 hours. In contrast, the whisker movements evoked by optogenetic muscle stimulation were up-regulated after denervation, including increased maximum protraction amplitude, increased sensitivity to low-intensity stimuli, and more sustained muscle contractions (reduced adaptation). Our results indicate that peripheral optogenetic stimulation is a promising technique for probing the timecourse of functional changes of both nerve and muscle, and holds potential for restoring movement after paralysis induced by nerve damage or motoneuron degeneration.

  7. Reinforcement of thermoplastic chitosan hydrogel using chitin whiskers optimized with response surface methodology.

    Science.gov (United States)

    Sun, Guohui; Zhang, Xin; Bao, Zixian; Lang, Xuqian; Zhou, Zhongzheng; Li, Yang; Feng, Chao; Chen, Xiguang

    2018-06-01

    To strengthen the mechanical strength of thermo-sensitive hydroxybutyl chitosan (HBC) hydrogel, chitin whiskers were used as sticker to fabricate reinforced HBC (HBCW) hydrogel by using response surface methodology. Unlike the intrinsic network of HBC hydrogel, HBCW hydrogel showed a laminar shape with firm structure. The preparation condition was optimized by three-factor-three-level Box-Behnken design. The maximum mechanical strength (1011.11 Pa) was achieved at 50 °C, when the concentrations of HBC and chitin whiskers were 5.1 wt% and 2.0 wt%, respectively. The effects of temperature, pH value and NaCl concentration on mechanical strength of HBCW hydrogels were investigated via the oscillatory stress sweeps. The results showed that HBCW hydrogel could reach the maximum stiffness (∼1126 Pa) at 37 °C pH 12.0. Low pH and high salty ions could decrease the stability of hydrogel, while chitin whiskers could increase the stress tolerance and related ruptured strain of HBCW hydrogels. Copyright © 2018. Published by Elsevier Ltd.

  8. Zinc oxide crystal whiskers as a novel sorbent for solid-phase extraction of flavonoids.

    Science.gov (United States)

    Wang, Licheng; Shangguan, Yangnan; Hou, Xiudan; Jia, Yong; Liu, Shujuan; Sun, Yingxin; Guo, Yong

    2017-08-15

    As a novel solid-phase extraction material, zinc oxide crystal whiskers were used to extract flavonoid compounds and showed good extraction abilities. X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectroscopy and surface area/pore volume characterized the sorbent. The zinc oxide was packed into a solid-phase extraction micro-column and its extraction ability was evaluated by four model flavonoid compounds. The sample loading and elution parameters were optimized and the zinc oxide based analytical method for flavonoids was established. It showed that the method has wide linearities from 1 to 150μg/L and low limits of detection at 0.25μg/L. The relative standard deviations of a single column repeatability and column to column reproducibility were less than 6.8% and 10.6%. Several real samples were analyzed by the established method and satisfactory results were obtained. The interactions between flavonoids and zinc oxide were calculated and proved to be from the Van der Waals' forces between the 4p and 5d orbitals from zinc atom and the neighboring π orbitals from flavonoid phenyl groups. Moreover, the zinc oxide crystal whiskers showed good stability and could be reused more than 50 times under the operation conditions. This work proves that the zinc oxide crystal whiskers are a good candidate for flavonoids enrichment. Copyright © 2017. Published by Elsevier B.V.

  9. Whisker and Hillock formation on Sn, Sn-Cu and Sn-Pb electrodeposits

    International Nuclear Information System (INIS)

    Boettinger, W.J.; Johnson, C.E.; Bendersky, L.A.; Moon, K.-W.; Williams, M.E.; Stafford, G.R.

    2005-01-01

    High purity bright Sn, Sn-Cu and Sn-Pb layers, 3, 7 and 16 μm thick were electrodeposited on phosphor bronze cantilever beams in a rotating disk apparatus. Beam deflection measurements within 15 min of plating proved that all electrodeposits had in-plane compressive stress. In several days, the surfaces of the Sn-Cu deposits, which have the highest compressive stress, develop 50 μm contorted hillocks and 200 μm whiskers, pure Sn deposits develop 20 μm compact conical hillocks, and Sn-Pb deposits, which have the lowest compressive stress, remain unchanged. The differences between the initial compressive stresses for each alloy and pure Sn is due to the rapid precipitation of Cu 6 Sn 5 or Pb particles, respectively, within supersaturated Sn grains produced by electrodeposition. Over longer time, analysis of beam deflection measurements indicates that the compressive stress is augmented by the formation of Cu 6 Sn 5 on the bronze/Sn interface, while creep of the electrodeposit tends to decrease the compressive stress. Uniform creep occurs for Sn-Pb because it has an equi-axed grain structure. Localized creep in the form of hillocks and whiskers occurs for Sn and Sn-Cu because both have columnar structures. Compact hillocks form for the Sn deposits because the columnar grain boundaries are mobile. Contorted hillocks and whiskers form for the Sn-Cu deposits because the columnar grain boundary motion is impeded

  10. An Investigation of the Electrical Short Circuit Characteristics of Tin Whiskers

    Science.gov (United States)

    Courey, Karim J.

    2008-01-01

    Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that has a currently unknown probability associated with it. Due to contact resistance electrical shorts may not occur at lower voltage levels. In this experiment, we study the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit. From this data we can estimate the probability of an electrical short, as a function of voltage, given that a free tin whisker has bridged two adjacent exposed electrical conductors. Also, three tin whiskers grown from the same Space Shuttle Orbiter card guide used in the aforementioned experiment were cross-sectioned and studied using a focused ion beam (FIB). The rare polycrystalline structure seen in the FIB cross section was confirmed using transmission electron microscopy (TEM). The FIB was also used to cross section two card guides to facilitate the measurement of the grain size to determine that the tin plating on the card guides had a bright finish.

  11. Effect of heating parameters on sintering behaviors and properties of mullite whisker frameworks

    Science.gov (United States)

    Zhang, Y. M.; Zeng, D. J.; Wang, B.; Yang, J. F.

    2018-04-01

    Mullite whisker frameworks were fabricated by vapor-solid reaction with SiO2, Al2O3 and AlF3 powders as the whisker forming agent at high temperatures. The effects of heating temperature and soaking time on the weight loss, liner shrinkage, porosity, microstructure and compressive strength were investigated. The results showed that with the increasing of the sintering temperature and soaking time, the weight loss and liner shrinkage of the samples increased and the porosities decreased due to the accelerated vapor-solid reaction, resulting in strong bonding and grain growth of the mullite frameworks. The compressive strength of the samples increased with increasing the sintering temperature from 1500 to 1650 °C, and decreased with the soaking time extended to more than 5 h for 1500 °C and 2 h for 1650 °C. A maximum compressive strength of 142 MPa at a porosity of 62.3% was obtained for the mullite whisker framework heated at 1500 °C for 5 h. The enhanced strength was attributed to the strong bonding strength and fine mullite grains resulting from a relative lower heating temperature and a modest soaking time.

  12. Energy metrics for driving competitiveness of countries: Energy weakness magnitude, GDP per barrel and barrels per capita

    International Nuclear Information System (INIS)

    Coccia, Mario

    2010-01-01

    Energy metrics is the development of a whole new theoretical framework for the conception and measurement of energy and economic system performances, energy efficiency and productivity improvements with important political economy implications consistent with the best use of all natural and economic resources. The purpose of this research is to present some vital energy indicators based on magnitude and scale of energy weakness, GDP per barrel of oil that is an indicator of energy productivity and barrels (of oil) per capita that is an indicator of energy efficiency. Energy metrics can support the monitoring of energy and economic system performances in order to design effective energy strategy and political economy interventions focused on the 'competitive advantage' increase of countries in modern economies.

  13. The barrel muon spectrometer of the ATLAS detector has acquired its first cosmic event in a magnetic field produced by the barrel toroid magnet.

    CERN Multimedia

    2006-01-01

    A 3-D event display of a cosmic muon event, showing the path of a muon travelling through three layers of the barrel muon spectrometer. Three of the eight coils of the barrel toroid magnet can be seen in the top half of the drawing.

  14. Grinding Characteristics Of Directionally Aligned SiC Whisker Wheel-Comparison With Al2O3 Fiber Wheel

    Institute of Scientific and Technical Information of China (English)

    魏源迁; 山口胜美; 菊泽贤二; 洞口严; 中根正喜

    2003-01-01

    A unique SiC whisker wheel was invented,in which the whiskers were aligned normally to the grinding wheel surface.In this paper,grindabilities of the SiC whisker wheel are investigated and compared with those of other wheels of SiC grains,Al2O3 grains,as well as Al2O3 long and short fibres which were also aligned normally to the grinding wheel surface,respectively.The main research contents concern grinding characteristics of a directionally aligned SiC whisker wheel such as material-removal volume,wheel-wear rates,integrity of the ground surfaces,grinding ratios and grinding efficiency.Furthermore,grinding wheels of whiskers and fibres have a common disadvantage:they tend to load easily.The authors have proposed a simple method of loading-free grinding to overcome this propensity and investigate some related grinding characteristics under loading-free grinding conditions.

  15. Reversible man-in-the-barrel syndrome in myasthenia gravis

    Directory of Open Access Journals (Sweden)

    Poornima A Shah

    2016-01-01

    Full Text Available Man-in-the-barrel syndrome (MBS is an uncommon presentation due to bilateral, predominantly proximal muscle weakness that has not been described to be associated with myasthenia gravis. We describe a case of myasthenia gravis presenting as MBS. Additionally, he had significant wasting of the deltoids bilaterally with fibrillations on electromyography (EMG at rest and brief duration (3-6 ms bi/triphasic motor unit potentials (MUPs on submaximal effort apart from a decremental response on repetitive nerve stimulation (RNS at 2 Hz. While electrophysiology is an important tool in the diagnosis of myasthenia gravis, pathological EMG patterns do not exclude the diagnosis of myasthenia gravis.

  16. Reversible man-in-the-barrel syndrome in myasthenia gravis

    Science.gov (United States)

    Shah, Poornima A; Wadia, Pettarusp Murzban

    2016-01-01

    Man-in-the-barrel syndrome (MBS) is an uncommon presentation due to bilateral, predominantly proximal muscle weakness that has not been described to be associated with myasthenia gravis. We describe a case of myasthenia gravis presenting as MBS. Additionally, he had significant wasting of the deltoids bilaterally with fibrillations on electromyography (EMG) at rest and brief duration (3-6 ms) bi/triphasic motor unit potentials (MUPs) on submaximal effort apart from a decremental response on repetitive nerve stimulation (RNS) at 2 Hz. While electrophysiology is an important tool in the diagnosis of myasthenia gravis, pathological EMG patterns do not exclude the diagnosis of myasthenia gravis. PMID:27011638

  17. Spontaneous growth of whiskers on RE-bearing intermetallic compounds of Sn-RE, In-RE, and Pb-RE

    Energy Technology Data Exchange (ETDEWEB)

    Liu Meng [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Science, 72 Wenhua Road, Shenyang 110016 (China); Xian Aiping, E-mail: ap.xian@imr.ac.c [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Science, 72 Wenhua Road, Shenyang 110016 (China)

    2009-11-03

    A phenomenon of the whiskers growth on the bulk rare earth (RE)-intermetallic compounds of NdSn{sub 3}, NdIn{sub 3}, and LaPb{sub 3} is reported. The whiskers formed spontaneously on all of the RE-intermetallic compounds after exposed to room ambience (21-28 deg. C/20-56% RH, relative humidity) for several days. Among the samples, the propensity of whisker growth for NdSn{sub 3} is the strongest, on which the tin whiskers were flourishing and covered all of the surfaces after exposed to room ambience for 22 days; while LaPb{sub 3} is the secondary and NdIn{sub 3} is the last one. Observed by SEM, the whiskers were exhibited as different morphology, size, and number density. The XRD analysis confirms the existence of RE(OH){sub 3} after whiskers formed, also, the weight gain curve of the samples exposed to room ambience supports that a spontaneous chemical reaction of the RE-intermetallic compounds with water in room ambience takes place. In discussion, it is proposed that the fresh metal atoms released by the chemical reaction could be causative to result in nucleation and spontaneous growth of the whiskers, while the anisotropy of crystal structure could be a reason to understand the difference of the whisker growth behaviors between Sn and Pb.

  18. Spontaneous growth of whiskers on RE-bearing intermetallic compounds of Sn-RE, In-RE, and Pb-RE

    International Nuclear Information System (INIS)

    Liu Meng; Xian Aiping

    2009-01-01

    A phenomenon of the whiskers growth on the bulk rare earth (RE)-intermetallic compounds of NdSn 3 , NdIn 3 , and LaPb 3 is reported. The whiskers formed spontaneously on all of the RE-intermetallic compounds after exposed to room ambience (21-28 deg. C/20-56% RH, relative humidity) for several days. Among the samples, the propensity of whisker growth for NdSn 3 is the strongest, on which the tin whiskers were flourishing and covered all of the surfaces after exposed to room ambience for 22 days; while LaPb 3 is the secondary and NdIn 3 is the last one. Observed by SEM, the whiskers were exhibited as different morphology, size, and number density. The XRD analysis confirms the existence of RE(OH) 3 after whiskers formed, also, the weight gain curve of the samples exposed to room ambience supports that a spontaneous chemical reaction of the RE-intermetallic compounds with water in room ambience takes place. In discussion, it is proposed that the fresh metal atoms released by the chemical reaction could be causative to result in nucleation and spontaneous growth of the whiskers, while the anisotropy of crystal structure could be a reason to understand the difference of the whisker growth behaviors between Sn and Pb.

  19. An Empirical Model for Estimating the Probability of Electrical Short Circuits from Tin Whiskers-Part I

    Science.gov (United States)

    Courey, Karim; Wright, Clara; Asfour, Shihab; Bayliss, Jon; Ludwig, Larry

    2008-01-01

    Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that has a currently unknown probability associated with it. Due to contact resistance, electrical shorts may not occur at lower voltage levels. In this experiment, we study the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit. From this data, we can estimate the probability of an electrical short, as a function of voltage, given that a free tin whisker has bridged two adjacent exposed electrical conductors. In addition, three tin whiskers grown from the same Space Shuttle Orbiter card guide used in the aforementioned experiment were cross sectioned and studied using a focused ion beam (FIB).

  20. Anomalous growth of whisker-like bismuth-tin extrusions from tin-enriched tin-Bi deposits

    International Nuclear Information System (INIS)

    Hu, C.-C.; Tsai, Y.-D.; Lin, C.-C.; Lee, G.-L.; Chen, S.-W.; Lee, T.-C.; Wen, T.-C.

    2009-01-01

    This article shows the first finding that the anomalous growth of Bi-Sn extrusions from tin-enriched alloys (Sn-xBi with x between 20 and 10 wt.%) can be induced by post-plating annealing in N 2 between 145 and 260 deg. C for 10 min although metal whiskers were commonly formed on the surface of pure metals or alloys of the enriched component. From SEM observations, very similar to Sn whiskers, Bi-Sn extrusions vary in size, shape, length, and diameter with changing the annealing temperature, which are highly important in regarding the potential for failure of electronic products. Annealing resulting in thermal expansion of Sn grains is believed to squeeze the Bi-Sn alloys with relatively low melting points to form whisker-like extrusions although the exact mechanism is unclear

  1. Fenomen erozije cevi naoružanja / Gun barrel erosion

    Directory of Open Access Journals (Sweden)

    Slobodan Ilić

    2009-07-01

    Full Text Available U radu su prikazana dosadašnja istraživanja erozije cevi. Trošenje cevi je neizbežan proces do kojeg dolazi pri svakom opaljenju. Erozija cevi može se definisati kao progresivna povreda ili oštećenje površine cevi i proširenje kalibra usled opaljenja, koja utiče na: gubitak ili pad početne brzine projektila, tačnost i efektivnost oruđa. Kao glavni uzročnici koji utiču na intenzitet erozije cevi opisani su termički, hemijski i mehanički faktori. Njihov uticaj prikazan je u interakciji cev-projektil-barutno punjenje. / An overview of research into gun barrel erosion is presented in this paper. The gun bore wear is an unavoidable process during normal firing. The wear can be defined as progressive damage of the bore surface and enlargement of the bore, ultimately resulting in loss in the muzzle velocity, range and accuracy. Thermal, chemical and mechanical factors are described as major factors of gun barrel erosion. The influence of these factors is presented in the interaction of gun tube - projectile - propellant.

  2. Recent results from the DELPHI barrel ring imaging Cherenkov counter

    International Nuclear Information System (INIS)

    Anassontzis, E.G.; Ioannou, P.; Kalkanis, G.; Katsanevas, S.; Kontaxis, I.; Kourkoumelis, C.; Nounos, S.; Preve, P.; Resvanis, L.K.; Brunet, J.M.; Dolbeau, J.; Guglielmo, L.; Ledroit, F.; Poutot, D.; Tristram, G.

    1991-01-01

    The DELPHI detector, installed at LEP, is equipped with RICH (Ring Imaging Cherenkov) counters. The Barrel part incorporates a liquid (C 6 F 14 ) and a gaseous (C 5 F 12 ) radiator providing particle identification up to 20GeV/c. The Cherenkov protons of both radiators are detected by TPC-like photon detectors. The drift gas (75% CH 4 + 25% C 2 H 6 ) is doped with TMAE, but which the UV Cherenkov photons are converted into single free photo-electrons. These are drifted towards MWPC's at the end of the drift tubes and the space coordinates of the conversion point are determined. One half of the Barrel RICH is now equipped with drift tubes and has provided results from the liquid radiator since spring 1990. The gas radiator has been tested with C 2 F 6 as a preliminary filling since August 1990. The data obtained demonstrate the good particle identification potential. For the liquid radiator the number of detected photons per ring in hadron jets is N=8, whereas for muon pairs (single tracks) N=10 has been obtained. For the gas radiator 2.1 photons per track were observed, which demonstrates the good functioning of the focussing mirrors, as the C 2 F 6 this is close to the expected value

  3. First physics pulses in the Barrel Electromagnetic Calorimeter with cosmics

    CERN Multimedia

    Laurent Serin

    2006-01-01

    The electromagnetic barrel calorimeter has been installed in its final position in October 2005. Since then, the calorimeter is being equipped with front-end electronics. Starting in April 2006, electronics calibration runs are taken a few times per week to debug the electronics and to study the performance in the pit (stability, noise). Today, 10 out of the 32 Front End crates are being read out, amounting to about 35000 channels. cool down, few little typos --> After a 6-week cool down, the barrel cryostat was filled with Liquid Argon in May. The presence of a few shorts (~1MΩ) at the edges of the modules was indicating the possibility of conducting dust having entered into the calorimeter with the flowing liquid. In order to try to improve this situation, the calorimeter was emptied and filled again, but this time by condensating the argon instead of flowing it in liquid phase. The new High Voltage tests are not showing any significant improvement but the situation is statisfactory for ATLAS runn...

  4. Sensory Prioritization in Rats: Behavioral Performance and Neuronal Correlates.

    Science.gov (United States)

    Lee, Conrad C Y; Diamond, Mathew E; Arabzadeh, Ehsan

    2016-03-16

    Operating with some finite quantity of processing resources, an animal would benefit from prioritizing the sensory modality expected to provide key information in a particular context. The present study investigated whether rats dedicate attentional resources to the sensory modality in which a near-threshold event is more likely to occur. We manipulated attention by controlling the likelihood with which a stimulus was presented from one of two modalities. In a whisker session, 80% of trials contained a brief vibration stimulus applied to whiskers and the remaining 20% of trials contained a brief change of luminance. These likelihoods were reversed in a visual session. When a stimulus was presented in the high-likelihood context, detection performance increased and was faster compared with the same stimulus presented in the low-likelihood context. Sensory prioritization was also reflected in neuronal activity in the vibrissal area of primary somatosensory cortex: single units responded differentially to the whisker vibration stimulus when presented with higher probability compared with lower probability. Neuronal activity in the vibrissal cortex displayed signatures of multiplicative gain control and enhanced response to vibration stimuli during the whisker session. In conclusion, rats allocate priority to the more likely stimulus modality and the primary sensory cortex may participate in the redistribution of resources. Detection of low-amplitude events is critical to survival; for example, to warn prey of predators. To formulate a response, decision-making systems must extract minute neuronal signals from the sensory modality that provides key information. Here, we identify the behavioral and neuronal correlates of sensory prioritization in rats. Rats were trained to detect whisker vibrations or visual flickers. Stimuli were embedded in two contexts in which either visual or whisker modality was more likely to occur. When a stimulus was presented in the high

  5. Helical patterns of magnetization and magnetic charge density in iron whiskers

    Science.gov (United States)

    Templeton, Terry L.; Hanham, Scott D.; Arrott, Anthony S.

    2018-05-01

    Studies with the (1 1 1) axis along the long axis of an iron whisker, 40 years ago, showed two phenomena that have remained unexplained: 1) In low fields, there are six peaks in the ac susceptibility, separated by 0.2 mT; 2) Bitter patterns showed striped domain patterns. Multipole columns of magnetic charge density distort to form helical patterns of the magnetization, accounting for the peaks in the susceptibility from the propagation of edge solitons along the intersections of the six sides of a (1 1 1) whisker. The stripes follow the helices. We report micromagnetic simulations in cylinders with various geometries for the cross-sections from rectangular, to hexagonal, to circular, with wide ranges of sizes and lengths, and different anisotropies, including (0 0 1) whiskers and the hypothetical case of no anisotropy. The helical patterns have been there in previous studies, but overlooked. The surface swirls and body helices are connected, but have their own individual behaviors. The magnetization patterns are more easily understood when viewed observing the scalar divergences of the magnetization as isosurfaces of magnetic charge density. The plus and minus charge densities form columns that interact with unlike charges attracting, but not annihilating as they are paid for by a decrease in exchange energy. Just as they start to form the helix, the columns are multipoles. If one could stretch the columns, the self-energy of the charges in a column would be diminished while making the attractive interactions of the unlike charges larger. The columns elongate by becoming helical. The visualization of 3-D magnetic charge distributions aids in the understanding of magnetization in soft magnetic materials.

  6. Effects of chitin nano-whiskers on the antibacterial and physicochemical properties of maize starch films.

    Science.gov (United States)

    Qin, Yang; Zhang, Shuangling; Yu, Jing; Yang, Jie; Xiong, Liu; Sun, Qingjie

    2016-08-20

    We investigated the effects of chitin nano-whiskers (CNWs) on the antibacterial and physiochemical properties of maize starch-based films. The microstructures, crystalline structures, and thermal, mechanical and barrier properties of the nanocomposite films were characterized by using transmission electron microscopy, X-ray diffraction analysis, thermogravimetric, differential scanning calorimeter, and texture profile analysis. The tensile strength of the maize starch films increased from 1.64MPa to 3.69MPa (Pstarch films. Furthermore, the nanocomposite films exhibited strong antimicrobial activity against Gram-positive Listeria monocytogenes but not against Gram-negative Escherichia coli. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Installation of CMS EB (ECAL Barrel) Supermodules 5 and 13 inside HB+ (HCAL Barrel) on 26/27 April 2006

    CERN Multimedia

    Ken Bell, RAL

    2006-01-01

    The first two barrel "supermodules" of the CMS Electromagnetic Calorimeter (ECAL) have been inserted into the barrel hadron calorimeter (HCAL) in the CMS experimental hall (called SX5) in Cessy in preparation for the forthcoming magnet test and cosmic challenge (MTCC). Each of the two supermodules contains 1700 lead tungstate crystals in glass-fibre alveolar support structures, with associated avalanche photodiodes (APDs, for scintillation light detection), electronics and cooling system. See also the document CMS-PHO-OREACH-2006-019. The first two pictures show the two supermodules in their final position. Fig. 3: the "enfourneur" in position on the HB Cradle. Fig. 4: supermodule n. 5 and extension rails being lifted to the enforneur. Figs. 5-6: supermodule approaching the enforneur. Fig. 7: rotating the Enfourneur to the correct phi direction Figs. 8-9: aligning the extension rails with the rails inside HB and view from inside HB, once the rails are aligned. Figs. 10-12: insertion of supermodule n. 5. Fig. ...

  8. Classical clinical signs in rats experimemtally infected with Trypanosoma brucei

    Directory of Open Access Journals (Sweden)

    Nwoha Rosemary Ijeoma Ogechi

    2015-02-01

    Full Text Available Objective: To investigate clinical signs in Trypanosoma brucei infection in albino rats. Methods: Fourteen rats grouped into 2 with 7 rats in each group were used to determine classical clinical manifestation of Trypanosoma brucei infection in rats. Group A rats were uninfected control and Group B rats were infected with Trypanosoma brucei. Results: Parasitaemia was recorded in Group B by (3.86±0.34 d and the peak of parasitaemia was observed at Day 5 post infection. Classical signs observed included squint eyes, raised whiskers, lethargy, no weight loss, pyrexia, isolation from the other rats, and starry hair coat. Conclusions: These signs could be diagnostic or aid in diagnosis of Trypanosoma brucei infection in rats.

  9. Whiskers growth and self-healing in Ti-based metallic glasses during ion irradiation

    Science.gov (United States)

    Zhang, Kun; Hu, Zheng; Zhao, Ziqiang; Wei, Bingchen; Li, Yansen; Wei, Yuhang

    2018-04-01

    Ti-based metallic glasses were subjected to a 20 MeV Cl4+ ion radiation under liquid-nitrogen cooling. Their responses, as well as effects of the electronic excitation and nucleus-nucleus collision were evaluated. The collision cascade during irradiation typically changes the structure by increasing the liquid-like zone/cluster, or the content of the free volume. However, along the ion incident depth, the structure change is inhomogeneous. Numerous whiskers appear and aggregate on the side of the irradiation surface, which are several micrometers away from the edge. This corresponds with the maximum collision depth obtained by the Monte Carlo simulation, where nuclear loss plays a dominant role. Moreover, the liquid-like zone continually forms, which add to the whiskers growth and subsequent self-healing. Results suggest that the irradiation-induced local shear stress combines with the well-localized liquid-like zone results in the observed phenomena. This study demonstrates that metallic glasses have high morphological instability under ion irradiation, which assets can pave new paths for their further applications.

  10. Zirconia toughened SiC whisker reinforced alumina composites small business innovation research

    Science.gov (United States)

    Loutfy, R. O.; Stuffle, K. L.; Withers, J. C.; Lee, C. T.

    1987-01-01

    The objective of this phase 1 project was to develop a ceramic composite with superior fracture toughness and high strength, based on combining two toughness inducing materials: zirconia for transformation toughening and SiC whiskers for reinforcement, in a controlled microstructure alumina matrix. The controlled matrix microstructure is obtained by controlling the nucleation frequency of the alumina gel with seeds (submicron alpha-alumina). The results demonstrate the technical feasibility of producing superior binary composites (Al2O3-ZrO2) and tertiary composites (Al2O3-ZrO2-SiC). Thirty-two composites were prepared, consolidated, and fracture toughness tested. Statistical analysis of the results showed that: (1) the SiC type is the key statistically significant factor for increased toughness; (2) sol-gel processing with a-alumina seed had a statistically significant effect on increasing toughness of the binary and tertiary composites compared to the corresponding mixed powder processing; and (3) ZrO2 content within the range investigated had a minor effect. Binary composites with an average critical fracture toughness of 6.6MPam sup 1/2, were obtained. Tertiary composites with critical fracture toughness in the range of 9.3 to 10.1 MPam sup 1/2 were obtained. Results indicate that these composites are superior to zirconia toughened alumina and SiC whisker reinforced alumina ceramic composites produced by conventional techniques with similar composition from published data.

  11. Mapping functional connectivity in barrel-related columns reveals layer- and cell type-specific microcircuits.

    NARCIS (Netherlands)

    Schubert, D.; Kotter, R.; Staiger, J.F.

    2007-01-01

    Synaptic circuits bind together functional modules of the neocortex. We aim to clarify in a rodent model how intra- and transcolumnar microcircuits in the barrel cortex are laid out to segregate and also integrate sensory information. The primary somatosensory (barrel) cortex of rodents is the ideal

  12. Design and development of a work robot to place ATLAS SCT modules onto barrel cylinders

    International Nuclear Information System (INIS)

    Terada, S.; Kobayashi, H.; Sengoku, H.; Kato, Y.; Hara, K.; Honma, F.; Ikegami, Y.; Iwata, Y.; Kohriki, T.; Kondo, T.; Nakano, I.; Takashima, R.; Tanaka, R.; Ujiie, N.; Unno, Y.; Yasuda, S.

    2005-01-01

    More than 2000 silicon modules need to be placed and fastened on the ATLAS SCT barrel tracker. A semi-automatic pick-and-place work robot was designed and developed to cope with the module placement for the SCT barrel assembly. We found that this robot could place modules to a mechanical precision of better than 25 μm

  13. Fabrication and Tests of M240 Machine Gun Barrels Lined with Stellite 25

    Science.gov (United States)

    2016-04-01

    ARL-TR-7662 ● APR 2016 US Army Research Laboratory Fabrication and Tests of M240 Machine Gun Barrels Lined with Stellite 25...Fabrication and Tests of M240 Machine Gun Barrels Lined with Stellite 25 by William S de Rosset and Sean Fudger Weapons and Materials Research...

  14. Design and development of a work robot to place ATLAS SCT modules onto barrel cylinders

    CERN Document Server

    Terada, S; Honma, F; Ikegami, Y; Iwata, Y; Kato, Y; Kobayashi, H; Kohriki, T; Kondo, T; Nakano, I; Sengoku, H; Takashima, R; Tanaka, R; Ujiie, N; Unno, Y; Yasuda, S

    2005-01-01

    More than 2000 silicon modules need to be placed and fastened on the ATLAS SCT barrel tracker. A semi-automatic pick-and-place work robot was designed and developed to cope with the module placement for the SCT barrel assembly. We found that this robot could place modules to a mechanical precision of better than 25 mum.

  15. Shell model in-water frequencies of the core barrel

    International Nuclear Information System (INIS)

    Takeuchi, K.; De Santo, D.F.

    1980-01-01

    Natural frequencies of a 1/24th-scale core barrel/vessel model in air and in water are measured by determining frequency responses to applied forces. The measured data are analyzed by the use of the one-dimensional fluid-structure computer code, MULTIFLEX, developed to calculate the hydraulic force. The fluid-structure interaction in the downcomer annulus is computed with a one-dimensional network model formed to be equivalent to two-dimensional fluid-structure interaction. The structural model incorporated in MULTIFLEX is substantially simpler than that necessary for structural analyses. Proposed for computation of structural dynamics is the projector method than can deal with the beam mode by modal analysis and the other shell modes by a direct integration method. Computed in-air and in-water frequencies agree fairly well with the experimental data, verifying the above MULTIFLEX technique

  16. The CMS Level-1 Trigger Barrel Track Finder

    International Nuclear Information System (INIS)

    Ero, J.; Wulz, C.; Evangelou, I.; Flouris, G.; Foudas, C.; Loukas, N.; Manthos, N.; Papadopoulos, I.; Paradas, E.; Guiducci, L.; Sotiropoulos, S.; Sphicas, P.; Triossi, A.

    2016-01-01

    The design and performance of the upgraded CMS Level-1 Trigger Barrel Muon Track Finder (BMTF) is presented. Monte Carlo simulation data as well as cosmic ray data from a CMS muon detector slice test have been used to study in detail the performance of the new track finder. The design architecture is based on twelve MP7 cards each of which uses a Xilinx Virtex-7 FPGA and can receive and transmit data at 10 Gbps from 72 input and 72 output fibers. According to the CMS Trigger Upgrade TDR the BMTF receives trigger primitive data which are computed using both RPC and DT data and transmits data from a number of muon candidates to the upgraded Global Muon Trigger. Results from detailed studies of comparisons between the BMTF algorithm results and the results of a C++ emulator are also presented. The new BMTF will be commissioned for data taking in 2016

  17. Manufacturing aspects of the ATLAS barrel toroid double pancakes

    CERN Document Server

    Drago, G; Gagliardi, P; Laurenti, A; Marabotto, R; Penco, R

    2002-01-01

    In 1999 INFN (Istituto Nazionale di Fisica Nucleare) ordered to ANSALDO the manufacturing of 16 double pancakes for the ATLAS BARREL TOROID. In July 2001 four Double Pancakes have already been completed and shipped to the integration site. In this paper the main aspects of the manufacturing of the largest superconducting coils ever built (5*25 m) are described. The main phases of the manufacturing procedure are reviewed starting from the conductor preparation to the VPI impregnation, including references to the materials used as well as to the relevant customer's requirements. In particular the special winding form and the winding technique are treated. For each phase the most critical aspects and the relevant solutions are pointed out. Particular details about the technical solutions adopted for the impregnation and curing of the Double Pancake, which could not be performed inside an autoclave due to the huge dimension of the coil itself, are reported. Finally the methods used for the dimensional and electri...

  18. Effect of Friction on Barreling during cold Upset Forging of Aluminium 6082 Alloy Solid cylinders

    Science.gov (United States)

    Priyadarshini, Amrita; Kiran, C. P.; Suresh, K.

    2018-03-01

    Friction is one of the significant factors in forging operations since it affects metal flow in the die, forming load, strain distribution, tool and die life, surface quality of the product etc. In upset forging, the frictional forces at the die-workpiece interface oppose the outward flow of the material due to which the specimen develops a barrel shape. As a result, the deformation becomes non-uniform or inhomogeneous which is undesirable. Barreling can be reduced by applying effective lubricant on the surface of the platens. The objective of the present work is to study experimentally the effect of various frictional conditions (dry, grease, mineral oil) on barreling during upset forging of aluminum 6082 solid cylinders of different aspect ratio (length/diameter: 0.5, 0.75, 1). The friction coefficients are determined using the ring compression test. Curvature of barrel is determined based on the assumption that the curvature of the barrel follows the geometry of circular arc.

  19. Study and analysis for the flow-induced vibration of the core barrel of a PWR

    International Nuclear Information System (INIS)

    Yao Weida; Shi Guolin; Jiang Nanyan

    1989-01-01

    The resemblance criteria are derived and a test model is designed by applying the flow-soild coupling theory. After having completed the model analysis of the pressurized water reactor (PWR) core barrel in an 1:10 model, the dynamic characteristics are obtained. In an 1:5 reactor model with a hydraulic closed loop, the hydraulic vibration tests of the core barrel are performed, and the relations between the flow rate and the flow-induced pulse pressure on core barrel, acceleration and strain signals have been measured. The corresponding responses and a group of computational equations for hydraulic vibration are derived from these two experiments. The computational hydraulic vibration responses for core barrel in Qinshan Nuclear Power Plant are in good agreement with the test results, and it shows that the core barrel is safe within its lifetime of 30 years

  20. Hydrothermal Preparation and Characterization of Ultralong Strontium-Substituted Hydroxyapatite Whiskers Using Acetamide as Homogeneous Precipitation Reagent

    Science.gov (United States)

    Xu, Jianqiang; Yang, Yaoqi; Wan, Rong; Zhang, Weibin

    2014-01-01

    The ultralong strontium- (Sr-) substituted hydroxyapatite (SrHAp) whiskers were successfully prepared using acetamide as homogeneous precipitation reagent. The effect of the Sr substitution amount on the lattice constants and proliferation of human osteoblast cells (MG-63) was further investigated. The results showed that the SrHAp whiskers with diameter of 0.2–12 μm and ultralong length up to 200 μm were obtained and the Sr substitution level could be facilely tailored by regulating the initial molar ratio of Sr/(Sr + Ca) in raw materials. The Sr2+ replaced part of Ca2+ and the lattice constants increased apparently with the increase of the Sr substitution amount. Compared with the pure HAp whiskers, the Sr substitution apparently stimulated the proliferation of MG-63 at certain extracted concentrations. Our study suggested that the obtained SrHAp whiskers might be used as bioactive and mechanical reinforcement materials for hard tissue regeneration applications. PMID:24592192

  1. Developing an Empirical Model for Estimating the Probability of Electrical Short Circuits from Tin Whiskers. Part 2

    Science.gov (United States)

    Courey, Karim J.; Asfour, Shihab S.; Onar, Arzu; Bayliss, Jon A.; Ludwig, Larry L.; Wright, Maria C.

    2009-01-01

    To comply with lead-free legislation, many manufacturers have converted from tin-lead to pure tin finishes of electronic components. However, pure tin finishes have a greater propensity to grow tin whiskers than tin-lead finishes. Since tin whiskers present an electrical short circuit hazard in electronic components, simulations have been developed to quantify the risk of said short circuits occurring. Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that had an unknown probability associated with it. Note however that due to contact resistance electrical shorts may not occur at lower voltage levels. In our first article we developed an empirical probability model for tin whisker shorting. In this paper, we develop a more comprehensive empirical model using a refined experiment with a larger sample size, in which we studied the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit. From the resulting data we estimated the probability distribution of an electrical short, as a function of voltage. In addition, the unexpected polycrystalline structure seen in the focused ion beam (FIB) cross section in the first experiment was confirmed in this experiment using transmission electron microscopy (TEM). The FIB was also used to cross section two card guides to facilitate the measurement of the grain size of each card guide's tin plating to determine its finish.

  2. Assembly of 5.5-Meter Diameter Developmental Barrel Segments for the Ares I Upper Stage

    Science.gov (United States)

    Carter, Robert W.

    2011-01-01

    Full scale assembly welding of Ares I Upper Stage 5.5-Meter diameter cryogenic tank barrel segments has been performed at the Marshall Space Flight Center (MSFC). One full-scale developmental article produced under the Ares 1 Upper Stage project is the Manufacturing Demonstration Article (MDA) Barrel. This presentation will focus on the welded assembly of this barrel section, and associated lessons learned. Among the MDA articles planned on the Ares 1 Program, the Barrel was the first to be completed, primarily because the process of manufacture from piece parts (barrel panels) utilized the most mature friction stir process planned for use on the Ares US program: Conventional fixed pin Friction Stir Welding (FSW). This process is in use on other space launch systems, including the Shuttle s External Tank, the Delta IV common booster core, the Delta II, and the Atlas V rockets. The goals for the MDA Barrel development were several fold: 1) to prove out Marshall Space Flight Center s new Vertical Weld Tool for use in manufacture of cylindrical barrel sections, 2) to serve as a first run for weld qualification to a new weld specification, and 3) to provide a full size cylindrical section for downstream use in precision cleaning and Spray-on Foam Insulation development. The progression leading into the welding of the full size barrel included sub scale panel welding, subscale cylinder welding, a full length confidence weld, and finally, the 3 seamed MDA barrel processing. Lessons learned on this MDA program have been carried forward into the production tooling for the Ares 1 US Program, and in the use of the MSFC VWT in processing other large scale hardware, including two 8.4 meter diameter Shuttle External Tank barrel sections that are currently being used in structural analysis to validate shell buckling models.

  3. Rats

    Directory of Open Access Journals (Sweden)

    Alexey Kondrashov

    2012-01-01

    Full Text Available We aimed to perform a chemical analysis of both Alibernet red wine and an alcohol-free Alibernet red wine extract (AWE and to investigate the effects of AWE on nitric oxide and reactive oxygen species production as well as blood pressure development in normotensive Wistar Kyoto (WKY and spontaneously hypertensive rats (SHRs. Total antioxidant capacity together with total phenolic and selected mineral content was measured in wine and AWE. Young 6-week-old male WKY and SHR were treated with AWE (24,2 mg/kg/day for 3 weeks. Total NOS and SOD activities, eNOS and SOD1 protein expressions, and superoxide production were determined in the tissues. Both antioxidant capacity and phenolic content were significantly higher in AWE compared to wine. The AWE increased NOS activity in the left ventricle, aorta, and kidney of SHR, while it did not change NOS activity in WKY rats. Similarly, increased SOD activity in the plasma and left ventricle was observed in SHR only. There were no changes in eNOS and SOD1 expressions. In conclusion, phenolics and minerals included in AWE may contribute directly to increased NOS and SOD activities of SHR. Nevertheless, 3 weeks of AWE treatment failed to affect blood pressure of SHR.

  4. Fabricação de compósitos com matriz de alumina reforçada com whiskers de mulita

    OpenAIRE

    Salles, Mário César Fernandez de

    2008-01-01

    Neste trabalho foram fabricados compósitos cerâmicos utilizando alumina como matriz e whiskers de mulita como reforço. As composições de whiskers foram 10, 20, 30 e 40% em peso. Os whiskers de mulita utilizados como matérias-primas foram obtidos através do tratamento térmico do mineral topázio incolor no Laboratório de Tratamento Térmico de Materiais do ICEB/UFOP. A alumina de elevada pureza foi fornecida pela empresa Alfa Apesar. As matérias primas, após serem pesadas, foram submetidas a um ...

  5. Electroluminescence of Zn{sub 2}GeO{sub 4}:Mn through SiC whisker electric field enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Wagstaff, Brandon, E-mail: wagstabj@mcmaster.ca [McMaster University, Department of Engineering Physics, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8 (Canada); Kitai, Adrian, E-mail: kitaia@mcmaster.ca [McMaster University, Department of Engineering Physics, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8 (Canada); McMaster University, Department of Materials Science and Engineering, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8 (Canada)

    2015-11-15

    Alternating current (AC) electroluminescence of thin film oxide phosphors is well known. However in this work electroluminescence of bulk oxide powder phosphors is achieved. A new type of AC Electroluminescent (ACEL) device has been created and developed by integrating SiC whiskers into a phosphor matrix composed of manganese-activated zinc germanate (Zn{sub 2}GeO{sub 4}:Mn{sup 2+}). The conductive SiC whiskers enhance the average electric field in specific regions of the phosphor such that localized breakdown of the phosphor occurs, thus emitting green light. This field enhancement allows light emission to occur in thick film oxide powder phosphors and is notably the first time that bright and reasonably efficient electroluminescence of zinc germanate has been observed without using expensive thin film deposition techniques. Light emission has been achieved in thick pressed pellets using surface-deposited electrodes and the brightness-voltage characteristics of light emission are shown to be consistent with field emission of carriers from the embedded whiskers. - Highlights: • A new electroluminescent phosphor, Zn{sub 2}GeO{sub 4}Mn{sup 2+}+SiC whiskers, is proposed. • A procedure is described to fabricate a solid sample of this composite material. • Under an AC voltage, green light is emitted only in samples containing the SiC whiskers. • A brightness of 25 Cd/m{sup 2} and efficiency of 0.25 Lm/W is observed 9.6×10{sup 6} V/m. • This is notably the first time that ACEL has been observed in bulk Zn{sub 2}GeO{sub 4}Mn{sup 2+}.

  6. The TIM Barrel Architecture Facilitated the Early Evolution of Protein-Mediated Metabolism.

    Science.gov (United States)

    Goldman, Aaron David; Beatty, Joshua T; Landweber, Laura F

    2016-01-01

    The triosephosphate isomerase (TIM) barrel protein fold is a structurally repetitive architecture that is present in approximately 10% of all enzymes. It is generally assumed that this ubiquity in modern proteomes reflects an essential historical role in early protein-mediated metabolism. Here, we provide quantitative and comparative analyses to support several hypotheses about the early importance of the TIM barrel architecture. An information theoretical analysis of protein structures supports the hypothesis that the TIM barrel architecture could arise more easily by duplication and recombination compared to other mixed α/β structures. We show that TIM barrel enzymes corresponding to the most taxonomically broad superfamilies also have the broadest range of functions, often aided by metal and nucleotide-derived cofactors that are thought to reflect an earlier stage of metabolic evolution. By comparison to other putatively ancient protein architectures, we find that the functional diversity of TIM barrel proteins cannot be explained simply by their antiquity. Instead, the breadth of TIM barrel functions can be explained, in part, by the incorporation of a broad range of cofactors, a trend that does not appear to be shared by proteins in general. These results support the hypothesis that the simple and functionally general TIM barrel architecture may have arisen early in the evolution of protein biosynthesis and provided an ideal scaffold to facilitate the metabolic transition from ribozymes, peptides, and geochemical catalysts to modern protein enzymes.

  7. Cellulose whiskers from sisal fibers: a study about the variable of extraction by acid hydrolysis

    International Nuclear Information System (INIS)

    Teodoro, Kelcilene B.R.; Teixeira, Eliangela de Morais; Correa, Ana Carolina; Campos, Adriana de; Marconcini, Jose Manoel; Mattoso, Luiz Henrique Capparelli

    2011-01-01

    The incorporation of cellulosic nanostructures in polymeric matrices has been studied due to their properties of biodegradation, and expected higher mechanical performance than the traditional composites. In this work, cellulose nanofibers were obtained from sisal bleached with reagents without chlorine, where it was used an acid mixture, with acetic acid and nitric acid, and after the bleached fibers were submitted to acid hydrolysis. The influence of the temperature and time of hydrolysis on the morphology and dimensions, crystallinity and thermal stability were analyzed by scanning transmission electronic microscopy (TEM), x-ray diffraction (XRD) and thermogravimetric analysis (TGA), respectively. The hydrolysis condition of 60 deg C and 15 minutes showed to be the most effective condition to obtain whiskers from sisal fibers, resulting in nanostructures with higher crystallinity and thermal. (author)

  8. Enhancing light emission in flexible AC electroluminescent devices by tetrapod-like zinc oxide whiskers.

    Science.gov (United States)

    Wen, Li; Liu, Nishuang; Wang, Siliang; Zhang, Hui; Zhao, Wanqiu; Yang, Zhichun; Wang, Yumei; Su, Jun; Li, Luying; Long, Fei; Zou, Zhengguang; Gao, Yihua

    2016-10-03

    Flexible alternating current electroluminescent devices (ACEL) are more and more popular and widely used in liquid-crystal display back-lighting, large-scale architectural and decorative lighting due to their uniform light emission, low power consumption and high resolution. However, presently how to acquire high brightness under a certain voltage are confronted with challenges. Here, we demonstrate an electroluminescence (EL) enhancing strategy that tetrapod-like ZnO whiskers (T-ZnOw) are added into the bottom electrode of carbon nanotubes (CNTs) instead of phosphor layer in flexible ACEL devices emitting blue, green and orange lights, and the brightness is greatly enhanced due to the coupling between the T-ZnOw and ZnS phosphor dispersed in the flexible polydimethylsiloxane (PDMS) layer. This strategy provides a new routine for the development of high performance, flexible and large-area ACEL devices.

  9. Performance of Silicon carbide whisker reinforced ceramic inserts on Inconel 718 in end milling process

    International Nuclear Information System (INIS)

    Reddy, M M; Joshua, C X H

    2016-01-01

    An experimental investigation is planned in order to study the machinability of Inconel 718 with silicon carbide whisker reinforced ceramic inserts in end milling process. The relationship between the cutting speed, feed rate, and depth of cut against the response factors are studied to show the level of significance of each parameter. The cutting parameters are optimized by using Taguchi method. Implementing analysis of variance, the parameter which influences the surface roughness the most is determined to be the cutting speed, followed by the feed rate and depth of cut. Meanwhile, the optimal cutting condition is determined to have high cutting speed, low feed rate, and high depth of cut in the range of selected parameters. (paper)

  10. Establishment of neurovascular congruency in the mouse whisker system by an independent patterning mechanism.

    Science.gov (United States)

    Oh, Won-Jong; Gu, Chenghua

    2013-10-16

    Nerves and vessels often run parallel to one another, a phenomenon that reflects their functional interdependency. Previous studies have suggested that neurovascular congruency in planar tissues such as skin is established through a "one-patterns-the-other" model, in which either the nervous system or the vascular system precedes developmentally and then instructs the other system to form using its established architecture as a template. Here, we find that, in tissues with complex three-dimensional structures such as the mouse whisker system, neurovascular congruency does not follow the previous model but rather is established via a mechanism in which nerves and vessels are patterned independently. Given the diversity of neurovascular structures in different tissues, guidance signals emanating from a central organizer in the specific target tissue may act as an important mechanism to establish neurovascular congruency patterns that facilitate unique target tissue function. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Phase and structural transformations in annealed copper coatings in relation to oxide whisker growth

    Energy Technology Data Exchange (ETDEWEB)

    Dorogov, M.V.; Priezzheva, A.N. [Togliatti State University, Belorusskaya 14, 445667 Togliatti (Russian Federation); Vlassov, S., E-mail: vlassovs@ut.ee [Institute of Solid State Physics, University of Latvia, Kengaraga 8, LV-1063 Riga (Latvia); Kink, I.; Shulga, E. [Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia); Dorogin, L.M. [Togliatti State University, Belorusskaya 14, 445667 Togliatti (Russian Federation); Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia); ITMO University, Kronverkskiy 49, 197101 Saint Petersburg (Russian Federation); Lõhmus, R. [Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia); Tyurkov, M.N.; Vikarchuk, A.A. [Togliatti State University, Belorusskaya 14, 445667 Togliatti (Russian Federation); Romanov, A.E. [Togliatti State University, Belorusskaya 14, 445667 Togliatti (Russian Federation); Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia); ITMO University, Kronverkskiy 49, 197101 Saint Petersburg (Russian Federation); Ioffe Physical Technical Institute, RAS, Polytechnicheskaya 26, 194021 Saint Petersburg (Russian Federation)

    2015-08-15

    Highlights: • Coatings prepared by Cu microparticle electrodeposition. • Structural and phase transformation in Cu coatings annealed at 400 °C. • Annealing is accompanied by intensive growth of CuO whiskers. • Layered oxide phases (Cu{sub 2}O and CuO) in the coating are characterized. • Formation of volumetric defects in the coating is demonstrated. - Abstract: We describe structural and phase transformation in copper coatings made of microparticles during heating and annealing in air in the temperature range up to 400 °C. Such thermal treatment is accompanied by intensive CuO nanowhisker growth on the coating surface and the formation of the layered oxide phases (Cu{sub 2}O and CuO) in the coating interior. X-ray diffraction and focused ion beam (FIB) are employed to characterize the multilayer structure of annealed copper coatings. Formation of volumetric defects such as voids and cracks in the coating is demonstrated.

  12. Syria: a waited petroleum production of 600 000 barrels per day for the end of 1993

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    This paper describes the reserves of petroleum deposits and gives statistical data on the production of the main oil fields in Syria. Petroleum production has grown from 160000 barrels per day in 1984 to 515000 barrels per day in 1992 and a production at a level of 600000 barrels per day is waited in 1993. Several petroleum companies, operating in Syria, have contributed to this rise, especially Al-Furat Petroleum Company (AFPC), joint venture between Syrian Petroleum Company (SPC) and Pecten/Shell/Deminex, followed by Deiz Ezzor Petroleum Company (DEZPC), association between the french company Elf Aquitaine and SPC. 2 tabs

  13. Vinten exposure measurements of the Salem Unit 1 lower core barrel

    International Nuclear Information System (INIS)

    Glennon, P.T.

    1988-01-01

    On November 6, 1987, the lower core barrel of Salem Unit I was removed from the reactor vessel and placed in the refueling pool as part of the unit's ten year inspection program. This paper deals with the supporting actions of the dosimetry group of PSE ampersand G. Prior to the move of the lower core barrel, Westinghouse predicted dose rates at one foot in water as a function of axial distance along the core barrel. This prediction was used in planning the health physics requirements associated with the move. It was agreed that a measurement of the axial dose rates would either lend confidence to the predictions or identify weaknesses in them

  14. Second Barrel Toroid Coil Installed in ATLAS Cavern

    CERN Multimedia

    Tappern, G.

    The second barrel toroid coil was lowered into the ATLAS Cavern on Friday, 26 November. The operation takes approximately five hours of precision crane and winch operations. Before lowering, several checks are made to ensure that no loose items have been left on the coil which would fall during the lowering down the shaft. This is a very difficult, but very important check, with the first coil in position, and partly below the shaft. After changing the winch tooling on Wednesday December 1st, the coil was lifted, rotated and placed into the feet. The girders which support the coil and the Z direction stops had all been pre-set before putting the coil in the feet. The angle is controlled by an inclinometer. When the final adjustments of position have been made, which will locate the coils at the plus/minus two mm level, the connection beams (voussoirs and struts) will be put in place; this requires a complex shimming procedure. This will lock together the two coils into the feet and forms the foundation for th...

  15. First ATLAS Barrel Toroid coil casing arrives at CERN

    CERN Multimedia

    2002-01-01

    The first of eight 25-metre long coil casings for the ATLAS experiment's barrel toroid magnet system arrived at CERN on Saturday 2 March by road from Heidelberg. This structure will be part of the largest superconducting toroid magnet ever made.   The first coil casing for the toroidal magnets of Atlas arrives at Building 180. This is the start of an enormous three-dimensional jigsaw puzzle. Each of the eight sets of double pancake coils will be housed inside aluminium coil casings, which in turn will be held inside a stainless steel vacuum vessel. A huge construction, the casing that arrived at CERN measures 25 metres in length and 5 metres in width. It weighs 20 tones. And this is just the beginning of the toroid jigsaw: by early April a batch of four double pancake coils, which altogether weighs 65 tones, will arrive from Ansaldo in Italy. The first vacuum vessel will also be arriving from Felguera in Spain this month. It will take about two years for all these 25 m long structures of casings, coils a...

  16. Double Barreled Wet Colostomy: Initial Experience and Literature Review

    Science.gov (United States)

    Salgado-Cruz, Luis; Espin-Basany, Eloy; Vallribera-Valls, Francesc; Sanchez-Garcia, Jose; Jimenez-Gomez, Luis Miguel; Marti-Gallostra, Marc; Garza-Maldonado, Ana

    2014-01-01

    Background. Pelvic exenteration and multivisceral resection in colorectal have been described as a curative and palliative intervention. Urinary tract reconstruction in a pelvic exenteration is achieved in most cases with an ileal conduit of Bricker, although different urinary reservoirs have been described. Methods. A retrospective and observational study of six patients who underwent a pelvic exenteration and urinary tract reconstruction with a double barreled wet colostomy (DBWC) was done, describing the preoperative diagnosis, the indication for the pelvic exenteration, the complications associated with the procedure, and the followup in a period of 5 years. A literature review of the case series reported of the technique was performed. Results. Six patients had a urinary tract reconstruction with the DBWC technique, 5 male patients and one female patient. Age range was from 20 to 77 years, with a medium age 53.6 years. The most frequent complication presented was a pelvic abscess in 3 patients (42.85%); all complications could be resolved with a conservative treatment. Conclusion. In the group of our patients with pelvic exenteration and urinary tract reconstruction with a DBWC, it is a safe procedure and well tolerated by the patients, and most of the complications can be resolved with conservative treatment. PMID:25574498

  17. Energy Resolution of the Barrel of the CMS Electromagnetic Calorimeter

    CERN Document Server

    Adzic, Petar; Almeida, Carlos; Almeida, Nuno; Anagnostou, Georgios; Anfreville, Marc; Anicin, Ivan; Antunovic, Zeljko; Auffray, Etiennette; Baccaro, Stefania; Baffioni, Stephanie; Baillon, Paul; Barney, David; Barone, Luciano; Barrillon, Pierre; Bartoloni, Alessandro; Beauceron, Stephanie; Beaudette, Florian; Bell, Ken W; Benetta, Robert; Bercher, Michel; Berthon, Ursula; Betev, Botjo; Beuselinck, Raymond; Bhardwaj, Ashutosh; Bialas, Wojciech; Biino, Cristina; Bimbot, Stephane; Blaha, Jan; Bloch, Philippe; Blyth, Simon; Bordalo, Paula; Bornheim, Adolf; Bourotte, Jean; Britton, David; Brown, Robert M; Brunelière, Renaud; Busson, Philippe; Camporesi, Tiziano; Cartiglia, Nicolo; Cavallari, Francesca; Cerutti, Muriel; Chamont, David; Chang, Paoti; Chang, You-Hao; Charlot, Claude; Chatterji, Sudeep; Chen, E Augustine; Chipaux, Rémi; Choudhary, Brajesh C; Cockerill, David J A; Collard, Caroline; Combaret, Christophe; Cossutti, Fabio; Da Silva, J C; Dafinei, Ioan; Daskalakis, Georgios; Davatz, Giovanna; Decotigny, David; De Min, Alberto; Deiters, Konrad; Dejardin, Marc; Del Re, Daniele; Della Negra, Rodolphe; Della Ricca, Giuseppe; Depasse, Pierre; Descamp, J; Dewhirst, Guy; Dhawan, Satish; Diemoz, Marcella; Dissertori, Günther; Dittmar, Michael; Djambazov, Lubomir; Dobrzynski, Ludwik; Drndarevic, Snezana; Dupanloup, Michel; Dzelalija, Mile; Ehlers, Jan; El-Mamouni, H; Peisert, Anna; Evangelou, Ioannis; Fabbro, Bernard; Faure, Jean-Louis; Fay, Jean; Ferri, Federico; Flower, Paul S; Franzoni, Giovanni; Funk, Wolfgang; Gaillac, Anne-Marie; Gargiulo, Corrado; Gascon-Shotkin, S; Geerebaert, Yannick; Gentit, François-Xavier; Ghezzi, Alessio; Gilly, Jean; Giolo-Nicollerat, Anne-Sylvie; Givernaud, Alain; Gninenko, Sergei; Go, Apollo; Godinovic, Nikola; Golubev, Nikolai; Golutvin, Igor; Gómez-Reino, Robert; Govoni, Pietro; Grahl, James; Gras, Philippe; Greenhalgh, Justin; Guillaud, Jean-Paul; Haguenauer, Maurice; Hamel De Montechenault, G; Hansen, Magnus; Heath, Helen F; Hill, Jack; Hobson, Peter R; Holmes, Daniel; Holzner, André; Hou, George Wei-Shu; Ille, Bernard; Ingram, Quentin; Jain, Adarsh; Jarry, Patrick; Jauffret, C; Jha, Manoj; Karar, M A; Kataria, Sushil Kumar; Katchanov, V A; Kennedy, Bruce W; Kloukinas, Kostas; Kokkas, Panagiotis; Korjik, M; Krasnikov, Nikolai; Krpic, Dragomir; Kyriakis, Aristotelis; Lebeau, Michel; Lecomte, Pierre; Lecoq, Paul; Lemaire, Marie-Claude; Lethuillier, Morgan; Lin, Willis; Lintern, A L; Lister, Alison; Litvin, V; Locci, Elizabeth; Lodge, Anthony B; Longo, Egidio; Loukas, Demetrios; Luckey, D; Lustermann, Werner; Lynch, Clare; MacKay, Catherine Kirsty; Malberti, Martina; Maletic, Dimitrije; Mandjavidze, Irakli; Manthos, Nikolaos; Markou, Athanasios; Mathez, Hervé; Mathieu, Antoine; Matveev, Viktor; Maurelli, Georges; Menichetti, Ezio; Meridiani, Paolo; Milenovic, Predrag; Milleret, Gérard; Miné, Philippe; Mur, Michel; Musienko, Yuri; Nardulli, Alessandro; Nash, Jordan; Neal, Homer; Nédélec, Patrick; Negri, Pietro; Nessi-Tedaldi, Francesca; Newman, Harvey B; Nikitenko, Alexander; Obertino, Maria Margherita; Ofierzynski, Radoslaw Adrian; Organtini, Giovanni; Paganini, Pascal; Paganoni, Marco; Papadopoulos, Ioannis; Paramatti, Riccardo; Pastrone, Nadia; Pauss, Felicitas; Puljak, Ivica; Pullia, Antonino; Puzovic, Jovan; Ragazzi, Stefano; Ramos, Sergio; Rahatlou, Shahram; Rander, John; Ranjan, Kirti; Ravat, Olivier; Raymond, M; Razis, Panos A; Redaelli, Nicola; Renker, Dieter; Reucroft, Steve; Reymond, Jean-Marc; Reynaud, Michel; Reynaud, Serge; Romanteau, Thierry; Rondeaux, Françoise; Rosowsky, André; Rovelli, Chiara; Rumerio, Paolo; Rusack, Roger; Rusakov, Sergey V; Ryan, Matthew John; Rykaczewski, Hans; Sakhelashvili, Tariel; Salerno, Roberto; Santos, Marcelino; Seez, Christopher; Semeniouk, Igor; Sharif, Omar; Sharp, Peter; Shepherd-Themistocleous, Claire; Shevchenko, Sergey; Shivpuri, Ram Krishen; Sidiropoulos, Georgios; Sillou, Daniel; Singovsky, Alexander; Sirois, Y; Sirunyan, Albert M; Smith, Brian; Smith, Vincent J; Sproston, Martin; Suter, Henry; Swain, John; Tabarelli de Fatis, Tommaso; Takahashi, Maiko; Tapper, Robert J; Tcheremoukhine, Alexandre; Teixeira, Isabel; Teixeira, Joao Paulo; Teller, Olivier; Timlin, Claire; Triantis, F A; Troshin, Sergey; Tyurin, Nikolay; Ueno, Koji; Uzunian, Andrey; Varela, Joao; Vaz-Cardoso, N; Verrecchia, Patrice; Vichoudis, Paschalis; Vigano, S; Viertel, Gert; Virdee, Tejinder; Vlassov, E; Wang, Minzu; Weinstein, Alan; Williams, Jennifer C; Yaselli, Ignacio; Zabi, Alexandre; Zamiatin, Nikolai; Zelepoukine, Serguei; Zeller, Michael E; Zhang, Lin; Zhang, Jia-Wen; Zhang, Yawei; Zhu, Kejun; Zhu, Ren-Yuan

    2007-01-01

    The energy resolution of the barrel part of the CMS Electromagnetic Calorimeter has been studied using electrons of 20 to 250 GeV in a test beam. The incident electron's energy was reconstructed by summing the energy measured in arrays of 3x3 or 5x5 channels. There was no significant amount of correlated noise observed within these arrays. For electrons incident at the centre of the studied 3x3 arrays of crystals, the mean stochastic term was measured to be 2.8% and the mean constant term to be 0.3%. The amount of the incident electron's energy which is contained within the array depends on its position of incidence. The variation of the containment with position is corrected for using the distribution of the measured energy within the array. For uniform illumination of a crystal with 120 GeV electrons a resolution of 0.5% was achieved. The energy resolution meets the design goal for the detector.

  18. Cryogenic Characteristics of the ATLAS Barrel Toroid Superconducting Magnet

    CERN Document Server

    Pengo, R; Delruelle, N; Pezzetti, M; Pirotte, O; Passardi, Giorgio; Dudarev, A; ten Kate, H

    2008-01-01

    ATLAS, one of the experiments of the LHC accelerator under commissioning at CERN, is equipped with a large superconducting magnet the Barrel Toroid (BT) that has been tested at nominal current (20500 A). The BT is composed of eight race-track superconducting coils (each one weights about 45 tons) forming the biggest air core toroidal magnet ever built. By means of a large throughput centrifugal pump, a forced flow (about 10 liter/second at 4.5 K) provides the indirect cooling of the coils in parallel. The paper describes the results of the measurements carried out on the complete cryogenic system assembled in the ATLAS cavern situated 100 m below the ground level. The measurements include, among other ones, the static heat loads, i.e., with no or constant current in the magnet, and the dynamic ones, since additional heat losses are produced, during the current ramp-up or slow dump, by eddy currents induced on the coil casing.

  19. Some developments in core-barrel vibration diagnostics

    International Nuclear Information System (INIS)

    Pazsit, I.; Karlsson, J.; Garis, N.S.

    1998-01-01

    Diagnostics of core-barrel motion, and notably that of beam mode vibrations, has been usually performed by two distinct concepts. One strategy is to perform a qualitative analysis in the time domain, using descriptors such as vibration trajectory, probability distributions etc. This approach is rather realistic in the sense that it allows for general anisotropic pendular vibrations. The other strategy is to use frequency analysis with the goal of quantifying certain vibration properties. However, this second approach could so far handle only isotropic and unidirectional vibrations. In this paper we propose a unification of these two approaches by introducing a model by which general anisotropic vibrations can be quantified in the frequency domain. However, when separating the noise components prior to the frequency analysis, we suggest the use of symmetry properties of the noise in the time domain, based on reactor physics assumptions, as opposed to the earlier methods that use statistical independence of the components. Due to the unified approach, a combination of time and frequency domain analysis methods can be used for presentation and maximum information extraction

  20. Barrel Toroid fully charged to nominal field, and it works!

    CERN Multimedia

    Herman ten Kate

    After a few weeks of testing up to intermediate currents, finally, on Thursday evening November 9, the current in the Barrel Toroid was pushed up to its nominal value of 20500 A and even 500 A beyond this value to prove that we have some margin. It went surprisingly well. Of course, the 8 coils forming the toroid were already tested individually at the surface but still, some surprise may have come from those parts added to the toroid in the cavern for the first time like the 8 cryoring sections linking the coils as well as the valve box at the bottom in sector 13 regulating the helium flow or the current lead cryostat on the top in sector 5. No training quenches, nothing to worry about, and the test was concluded with a fast dump triggered at 00:40 in the very early morning of November 10. (left) The toroid current during the evening and night of November 9. (right) The test crew oscillated between fear and hope while looking at the control panels as the current approached 21kA. Big relief was in the...

  1. Solid-state synthesis of Li{sub 4}Ti{sub 5}O{sub 12} whiskers from TiO{sub 2}-B

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Wenjun [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, No. 5 Xin Mofan Road, Nanjing 210009 (China); Zhuang, Wei [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, No. 5 Xin Mofan Road, Nanjing 210009 (China); College of Biotechnology and Pharmaceutical Engineering, National Engineering Technique Research Center for Biotechnology, Nanjing Tech University, No. 30, Puzhu South Road, Nanjing 211816 (China); Ji, Xiaoyan [Division of Energy Science/Energy Engineering, Luleå University of Technology, Luleå 97187 Sweden (Sweden); Chen, Jingjing; Lu, Xiaohua [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, No. 5 Xin Mofan Road, Nanjing 210009 (China); Wang, Changsong, E-mail: wcs@njtech.edu.cn [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, No. 5 Xin Mofan Road, Nanjing 210009 (China)

    2016-03-15

    Highlights: • The Li{sub 4}Ti{sub 5}O{sub 12} whiskers were synthesized from TiO{sub 2}-B whiskers via a solid state reaction. • The TiO{sub 2}-B crystal structure for lithium diffusion is easier than anatase. • The separated diffusion and reaction process is crucial for the solid-state syntheses of Li{sub 4}Ti{sub 5}O{sub 12} whiskers. - Abstract: In this work, Li{sub 4}Ti{sub 5}O{sub 12} (LTO) was synthesized from the precursors of TiO{sub 2}-B and anatase whiskers, respectively. The synthesized LTO whiskers from TiO{sub 2}-B whiskers via a solid state reaction at 650 °C have a high degree of crystallinity with an average diameter of 300 nm. However, when anatase whiskers were used as the precursor, only particle morphology LTO was produced at 750 °C. The further analysis of the precursors, the intermediate products and the final products reveal that the crystal structure of the anatase hinders the diffusion of lithium, leading to a typical reaction–diffusion process. Under this condition, only particle morphology LTO can be produced. However, the crystal structure of the TiO{sub 2}-B is easy for lithium diffusion and the process is performed in two separated steps (i.e., diffusion and reaction), which makes it possible to decrease the solid-state reaction temperature down to 650 °C and then maintain the morphologies of whiskers.

  2. A Front-End Readout Architecture for the CMS Barrel Muon Detector: A Feasibility Study

    International Nuclear Information System (INIS)

    Aguayo, P.; Alberdi, J.; Barcala, J.M.; Marin, J.; Molinero, A.; Navarrete, J.; Pablos, J.L. de; Romero, L.; Willmot, C.

    1995-01-01

    A feasibility study of a possible architecture for the CMS barrel muon detector readout electronics is presented. some aspects of system reliability are discussed. Values for the required FIFO's to store data during the first level trigger latency are given

  3. Astrocytes control GABAergic inhibition of neurons in the mouse barrel cortex

    Science.gov (United States)

    Benedetti, B; Matyash, V; Kettenmann, H

    2011-01-01

    Astrocytes in the barrel cortex respond with a transient Ca2+ increase to neuronal stimulation and this response is restricted to the stimulated barrel field. In the present study we suppressed the astrocyte response by dialysing these cells with the Ca2+ chelator BAPTA. Electrical stimulation triggered a depolarization in stellate or pyramidal ‘regular spiking’ neurons from cortex layer 4 and 2/3 and this response was augmented in amplitude and duration after astrocytes were dialysed with BAPTA. Combined blockade of GABAA and GABAB receptors mimicked the effect of BAPTA dialysis, while glutamate receptor blockers had no effect. Moreover, the frequency of spontaneous postsynaptic currents was increased after BAPTA dialysis. Outside the range of BAPTA dialysis astrocytes responded with a Ca2+ increase, but in contrast to control, the response was no longer restricted to one barrel field. Our findings indicate that astrocytes control neuronal inhibition in the barrel cortex. PMID:21224221

  4. Study and analysis on the flow induced vibration of the core barrel of PWR

    International Nuclear Information System (INIS)

    Yao Weida; Shi Guolin; Jiang Nanyan; Peng YongYong; Zhang Huijun; Wang Yufen; Xie Yongcheng; Guo Chunhua; Shen Qinping

    1989-01-01

    The deduction of the resemblance criterion and the design of the test model by applying flow-solid coupling theory are described. The model analysis of a core barrel both in the air and stationary water were performed in a 1:10 model, thus obtaining the dynamic characteristic. In a 1:5 reactor model with a hydraulic closed loop, the inner structure and support were modeled for performing hydraulic closed loop, the inner structure and support were modeled for performing hydraulic vibration test of the core barrel. The flow induced pulse pressure of the core barrel and corresponding response were obtained by using miniature pressure capsule, strain gauge and accelerometer. Power spectrum, correlation functions, transfer function and amplitudes under different flow velocities were calculated. The hydraulic vibration test shows that the core barrel will be in safety during its 30-year life time

  5. Astrocytes control GABAergic inhibition of neurons in the mouse barrel cortex.

    Science.gov (United States)

    Benedetti, B; Matyash, V; Kettenmann, H

    2011-03-01

    Astrocytes in the barrel cortex respond with a transient Ca2+ increase to neuronal stimulation and this response is restricted to the stimulated barrel field. In the present study we suppressed the astrocyte response by dialysing these cells with the Ca2+ chelator BAPTA. Electrical stimulation triggered a depolarization in stellate or pyramidal ‘regular spiking' neurons from cortex layer 4 and 2/3 and this response was augmented in amplitude and duration after astrocytes were dialysed with BAPTA. Combined blockade of GABAA and GABAB receptors mimicked the effect of BAPTA dialysis, while glutamate receptor blockers had no effect. Moreover, the frequency of spontaneous postsynaptic currents was increased after BAPTA dialysis. Outside the range of BAPTA dialysis astrocytes responded with a Ca2+ increase, but in contrast to control, the response was no longer restricted to one barrel field. Our findings indicate that astrocytes control neuronal inhibition in the barrel cortex.

  6. Posterior Thalamic Nucleus Modulation of Tactile Stimuli Processing in Rat Motor and Primary Somatosensory Cortices

    Directory of Open Access Journals (Sweden)

    Diana Casas-Torremocha

    2017-09-01

    Full Text Available Rodents move rhythmically their facial whiskers and compute differences between signals predicted and those resulting from the movement to infer information about objects near their head. These computations are carried out by a large network of forebrain structures that includes the thalamus and the primary somatosensory (S1BF and motor (M1wk cortices. Spatially and temporally precise mechanorreceptive whisker information reaches the S1BF cortex via the ventroposterior medial thalamic nucleus (VPM. Other whisker-related information may reach both M1wk and S1BF via the axons from the posterior thalamic nucleus (Po. However, Po axons may convey, in addition to direct sensory signals, the dynamic output of computations between whisker signals and descending motor commands. It has been proposed that this input may be relevant for adjusting cortical responses to predicted vs. unpredicted whisker signals, but the effects of Po input on M1wk and S1BF function have not been directly tested or compared in vivo. Here, using electrophysiology, optogenetics and pharmacological tools, we compared in adult rats M1wk and S1BF in vivo responses in the whisker areas of the motor and primary somatosensory cortices to passive multi-whisker deflection, their dependence on Po activity, and their changes after a brief intense activation of Po axons. We report that the latencies of the first component of tactile-evoked local field potentials in M1wk and S1BF are similar. The evoked potentials decrease markedly in M1wk, but not in S1BF, by injection in Po of the GABAA agonist muscimol. A brief high-frequency electrical stimulation of Po decreases the responsivity of M1wk and S1BF cells to subsequent whisker stimulation. This effect is prevented by the local application of omega-agatoxin, suggesting that it may in part depend on GABA release by fast-spiking parvalbumin (PV-expressing cortical interneurons. Local optogenetic activation of Po synapses in different

  7. Modeling two-phase flow in barrels of weapons with combined charges

    Directory of Open Access Journals (Sweden)

    Nebojša P. Hristov

    2011-10-01

    Full Text Available The processes occurring during the firing within barrels of weapons with combined charges are described aiming at the improvement of fire power of existing weapons and the design of new ones. The firing process simulation enables the optimization of gunpowders. The analysis of the obtained results helps in choosing the best combination of input-output parameters for the highest muzzle velocity possible while keeping powder gas maximum pressures inside the barrel at the lowest possible level.

  8. The composite barrel of retail prices and its relationship to crude oil prices

    International Nuclear Information System (INIS)

    Balabanoff, S.

    1993-01-01

    This paper challenges assumptions about the relationship between refinery gate prices, retail prices paid by consumers and crude oil prices. The analysis presented here considers their relationship within the context of the Organization of Petroleum Exporting Countries' (OPEC's) composite barrel statistics, which includes taxes and other government policy effects on prices. Speed of adjustment and retail price response to taxes are analysed with respect to crude import prices. OPEC's composite barrel is explained and evaluated. Test results are summarized. (UK)

  9. Criticality safety of storage barrels for enriched uranium fresh fuel at the RB research reactor

    International Nuclear Information System (INIS)

    Pesic, M. P.

    1997-01-01

    Study on criticality safety of fresh low and high enriched uranium (LEU and HEU) fuel elements in the storage/transport barrels at the RB research reactor is carried out by using the well-known MCNP computer code. It is shown that studied arrays of tightly closed fuel barrels, each entirely loaded with 100 fresh (HEU or LEU) fuel slugs, are far away from criticality, even in cases of an unexpected flooding by light water.(author)

  10. Monitoring of core barrel vibrations in WWER type reactor using out-of-reactor ionization chambers

    International Nuclear Information System (INIS)

    Dach, K.

    1982-01-01

    Vibration of the core barrel is least desirable for safe operation of the PWR reactor. These mechanical vibrations are in correlation with the fluctuations of neutron flux density whose time and frequency analysis serves failure diagnosis. The mathematical model is described of the transfer of mechanical vibrations of the core barrel to neutron noise. Other steps are indicated indispensable for the application of the method of neutron noise analysis for in-service diagnostics of nuclear power plants. (Z.M.)

  11. Energy calibration of the barrel calorimeter of the CMD-3 detector

    International Nuclear Information System (INIS)

    Anisenkov, A.V.; Aulchenko, V.M.; Bashtovoy, N.S.; Bondar, A.E.; Grebenuk, A.A.; Epifanov, D.A.; Epshteyn, L.B.; Erofeev, A.L.; Kovalenko, O.A.; Kozyrev, A.N.; Kuzmin, A.S.; Mikhailov, K.Yu.; Logashenko, I.B.; Razuvaev, G.P.; Ruban, A.A.; Shebalin, V.E.; Shwartz, B.A.; Talyshev, A.A.; Titov, V.M.; Yudin, Yu.V.

    2017-01-01

    The VEPP-2000 e + e − collider has been operated in the Budker Institute of Nuclear Physics since 2010. Experiments are carried out with two detectors CMD-3 and SND. The calorimetry at the CMD-3 detector is based on three subsystems, two coaxial barrel calorimeters—Liquid Xenon calorimeter and crystal CsI calorimeter, and end cap calorimeter with BGO crystals. This paper describes the procedures of the energy calibration of the combined barrel calorimeter of the CMD-3 detector.

  12. First half-barrel of the CMS hadron calorimeter successfully asembled

    CERN Multimedia

    2001-01-01

    The first half barrel of the CMS hadron calorimeter has been assembled in the CMS construction hall in Cessy (neighbouring France), called SX5, in October 2001. The picture sequence shows the insertion of the last (the keystone) wedge. It is lifted up to the top of the structure and carefully inserted into the half barrel. Photos 6 and 7 show the HB- in SX5.

  13. Fluid and structural dynamics calculations to determine core barrel loads during blowdown (EV 3,000)

    International Nuclear Information System (INIS)

    Krieg, R.; Schlechtendahl, E.G.

    1977-01-01

    To begin with, the main physical phenomena in connection with blowdown loads on the care barrel and the computer models used are briefly described. These models have also been used in the design of the HTR test care barrel. The fluid dynamics part of the calculations was carried out using the WHAMMOD and DAPSY codes; for the structural dynamics part, the STRUDL/Dynal code was employed. (orig./RW) [de

  14. Evolutions of volatile sulfur compounds of Cabernet Sauvignon wines during aging in different oak barrels.

    Science.gov (United States)

    Ye, Dong-Qing; Zheng, Xiao-Tian; Xu, Xiao-Qing; Wang, Yun-He; Duan, Chang-Qing; Liu, Yan-Lin

    2016-07-01

    The evolution of volatile sulfur compounds (VSCs) in Cabernet Sauvignon wines from seven regions of China during maturation in oak barrels was investigated. The barrels were made of different wood grains (fine and medium) and toasting levels (light and medium). Twelve VSCs were quantified by GC/FPD, with dimethyl sulfide (DMS) and methionol exceeding their sensory thresholds. Most VSCs tended to decline during the aging, while DMS was found to increase. After one year aging, the levels of DMS, 2-methyltetrahy-drothiophen-3-one and sulfur-containing esters were lower in the wines aged in oak barrels than in stainless steel tanks. The wood grain and toasting level of oak barrels significantly influenced the concentration of S-methyl thioacetate and 2-methyltetrahy-drothiophen-3-one. This study reported the evolution of VSCs in wines during oak barrel aging for the first time and evaluated the influence of barrel types, which would provide wine-makers with references in making proposals about wine aging. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Magneto-resistance of Si0,97Ge0,03 whiskers irradiated by reactor fast neutrons

    International Nuclear Information System (INIS)

    Pavlovska, N.T.; Litovchenko, P.G.; Karpenko, A.Ya.; Uhryn, Yu.O.; Pavlovskyj, Yu.V.; Ostrovskii, I.P.; Khoverko, Yu.M.

    2012-01-01

    The influence of reactor fast-neutrons irradiation by the fluence of 8,6·10 17 n/cm 2 and strong magnetic field (up to 14 T) on resistance of Si 1-x Ge x (x = 0.03) whiskers in the temperature range of 4,2 - 300 K is studied. The activation energy of the of impurity levels is calculated. The interpretation of changes in the magneto-resistance is proposed

  16. Electrochemical migration, whisker formation, and corrosion behavior of printed circuit board under wet H2S environment

    International Nuclear Information System (INIS)

    Zou, Shiwen; Li, Xiaogang; Dong, Chaofang; Ding, Kangkang; Xiao, Kui

    2013-01-01

    Highlights: •The electrochemical migration, whisker formation, and corrosion behavior of PCB under wet H 2 S environment were observed and studied systematically. •The process of electrochemical migration of solder joints is explained. •The corrosion mechanism of PCB interconnectors induced by micro pores under wet H 2 S environment is discussed, and the corrosion reaction model is proposed. -- Abstract: Electrochemical migration, whisker formation, and corrosion behavior of printed circuit board (PCB) under wet H 2 S environment were analyzed by environment scanning electron microscope (ESEM), Energy dispersive X-ray spectroscopy (EDS) with mapping and element phase cluster (EPC) techniques, Raman Spectrum analysis and electrochemical impedance spectroscopy (EIS) technology. The results showed that nonuniform corrosion behavior occurred on PCB surfaces under 1 ppm wet H 2 S at 40 °C; whiskers formed on the inner sidewall of via-holes with a growth rate of 1.2 Å/s; numerous corrosion products migrated through the pore of plated gold layer, which broke off the protective layer. The corrosion rate was accelerated according to the big-cathode-small-anode model

  17. Facile synthesis of Cu/tetrapod-like ZnO whisker compounds with enhanced photocatalytic properties

    Science.gov (United States)

    Liu, Hong; Liu, Huarong; Fan, Ximei

    2017-09-01

    Cu/tetrapod-like ZnO whisker (T-ZnOw) compounds were successfully synthesized using N2H4 \\cdot H2O as a reducing agent by a simple reduction method without any insert gas at room temperature. The crystal phase composition and morphology of the as-prepared samples were investigated by XRD, SEM and FESEM tests. The photocatalytic property of the as-prepared samples was detected by the degradation of methyl orange (MO) aqueous solution under UV irradiation. It can be found that Cu nanoparticles (CuNPs) dispersed on the surface of T-ZnOw increased with the increasing of Cu/Zn molar ratios (Cu/Zn MRs), and an octahedral structure of CuNPs was obtained when the sample was prepared with less than and equal to 7.30% Cu/Zn MR, but tended to a spherical or nanorod structure of CuNPs densely arranged on the surface of T-ZnOw, which is prepared by Cu/Zn MRs up to 22.00%. All the compounds exhibited excellent photocatalytic activity in decomposing of MO than T-ZnOw, the photocatalytic property of the samples increased with the increasing of Cu/Zn MRs up to 7.30%, while it decreases when further increasing the Cu/Zn MRs. The Schottky barrier of the Cu/T-ZnOw compound can effectively capture photoinduced electrons from the interface and enhanced the photocatalytic property of T-ZnOw.

  18. [Breeding biology of the whiskered auklet (Aethia pygmaea): incubation, chick growth, and feather ontogenesis].

    Science.gov (United States)

    Koniukhov, N B; Zubakin, V A; Williams, J; Fischer, J

    2000-01-01

    This is the second publication on the results of studies of the whiskered auklet breeding biology on Buldir Island. In 1993, according to the time of chick hatching the egg-laying period began in late April-early May. The single egg was incubated by both parents, which relieved each other once a day, usually at early night. Among the chicks under observation, the first hatched on June 11; the median of hatching was on June 17. After hatching, the egg shell usually remained in the nest. The chick was continuously brooded by one of parents for the first several days but since the age of 7-9 days, it stayed in the nest by itself during the daytime. Each parent fed the chick once a day, at early night, although occasional feedings were recorded also during daytime and at dawn. A newly hatched chick was covered by typical embryonal (natal) down. The remiges, rectrices, their coverts, and large feathers on pteryla humeralis had a mesoptile stage during their growth (the second down generation). The juvenile plumage consisted of semiplumes of types I and II and contour feathers of type I and, possibly, type II. In fledglings, the ornamental feathers were underdeveloped: the crest was absent and facial plumes only began growing. By reaching 100 g, the chicks left their nests at the age of about 37 days. A longer nesting period than in other Aethia auklets appears to be related to a low feeding rate due to the nocturnal activity in the colony.

  19. Assembly of a Full-Scale External Tank Barrel Section Using Friction Stir Welding

    Science.gov (United States)

    Jones, Chip; Adams, Glynn

    1999-01-01

    A full-scale pathfinder barrel section of the External Tank for the National Aeronautics and Space Administration (NASA) Space Transport System (Space Shuttle) has been assembled at Marshall Space Flight Center (MSFC) via a collaborative effort between NASA/MSFC and Lockheed Martin Michoud Space Systems. The barrel section is 27.5 feet in diameter and 15 feet in height. The barrel was assembled using Super-Light-Weight (SLWT), orthogrid, Al-Li 2195 panel sections and a single longeron panel. A vertical weld tool at MSFC was modified to accommodate FSW and used to assemble the barrel. These modifications included the addition of a FSW weld head and new controller hardware and software, the addition of a backing anvil and the replacement of the clamping system with individually actuated clamps. Weld process 4evelopment was initially conducted to optimize the process for the welds required for completing the assembly. The variable thickness welds in the longeron section were conducted via both two-sided welds and with the use of a retractable pin tool. The barrel assembly was completed in October 1998. Details of the vertical weld tool modifications and the assembly process are presented.

  20. Triggering and measuring bent cosmic muon tracks with the Muon Spectrometer barrel for the first time

    CERN Multimedia

    Fabio Cerutti

    During the ATLAS barrel toroid stability test, bent cosmic muon tracks were seen for the first time in the ATLAS cavern by means of the ATLAS muon spectrometer. The barrel toroid has been powered at its nominal current (20.5 thousand Amperes) and kept in steady state for more than one day during the weekend of 18-19 November (see a report on this test in the Magnet section). During this test one large sector and part of a small sector of the barrel muon spectrometer were readout and used to detect the cosmic muons tracks bent by the toroidal magnetic field. Thirteen muon stations in the feet sectors (sectors 13 and 14) have been used in this test. The muon stations are formed of Resistive Plate Chambers (RPC) that were providing the muon trigger, and Monitored Drift Tubes that were used to measure with high accuracy the muon curvature hence their momentum. The Level-1 Barrel trigger chain was based on the Barrel Middle Large chambers equipped with final production modules on both the on-detector and the o...

  1. Astringency, bitterness and color changes in dry red wines before and during oak barrel aging: An updated phenolic perspective review.

    Science.gov (United States)

    Li, Si-Yu; Duan, Chang-Qing

    2018-01-30

    To understand effects of using oak barrels on the astringency, bitterness and color of dry red wines, phenolic reactions in wines before and after barrel aging are reviewed in this paper, which has been divided into three sections. The first section includes an introduction to chemical reactivities of grape-derived phenolic compounds, a summary of the phenolic reactions that occur in dry red wines before barrel aging, and a discussion of the effects of these reactions on wine astringency, bitterness and color. The second section introduces barrel types that determine the oak barrel constituents in wines (primarily oak aldehydes and ellagitannins) and presents reactions between the oak constituents and grape-derived phenolic compounds that may modulate wine astringency, bitterness and color. The final section illustrates the chemical differences between basic oxidation and over-oxidation in wines, discusses oxygen consumption kinetics in wines during barrel aging by comparing different oxygen consumption kinetics observed previously by others, and speculates on the possible preliminary phenolic reactions that occur in dry red wines during oak barrel aging that soften tannins and stabilize pigments via basic oxidation. Additionally, sulfur dioxide (SO 2 ) addition during barrel aging and suitability of adopting oak barrels for aging wines are briefly discussed.

  2. A scintillating fibre detector for the Crystal Barrel experiment at ELSA

    International Nuclear Information System (INIS)

    Suft, G.; Anton, G.; Bogendoerfer, R.; Ehmanns, A.; Foesel, A.; Hoessl, J.; Kalinowsky, H.; Kueppersbusch, C.; Walther, D.

    2005-01-01

    A scintillating fibre detector with high spatial granularity was built for the Crystal Barrel experiment at ELSA (CB-ELSA) in Bonn. It consists of 513 scintillating fibres with 2mm in diameter, arranged in three layers with cylindrical geometry inside the Crystal Barrel detector surrounding the target cell. Two layers are wound in opposite directions, the third is parallel to the incident beam direction, resulting in an unambiguous hit reconstruction and a position resolution better than 1.6mm for charged particles. The read-out is done with 16-channel multi-anode photomultipliers. The detector was designed to cover the full angular acceptance of the Crystal Barrel detector with an angular range of 12 deg. ≤θ = 168 deg. and 0 deg. ≤φ≤360 deg. in the lab frame

  3. Analysis of core and core barrel heat-up under conditions simulating severe reactor accidents

    International Nuclear Information System (INIS)

    Chellaiah, S.; Viskanta, R.; Ranganathan, P.; Anand, N.K.

    1987-01-01

    This paper reports on the development of a model for estimating the temperature distributions in the reactor core, core barrel, thermal shield and reactor pressure vessel of a PWR during an undercooling transient. A number of numerical calculations simulating the core uncovering of the TMI-2 reactor and the subsequent heat-up of the core have been performed. The results of the calculations show that the exothermic heat release due to Zircaloy oxidation contributes to the sharp heat-up of the core. However, the core barrel temperature rise which is driven by the temperature increase of the edge of the core (e.g., the core baffle) is very modest. The maximum temperature of the core barrel never exceeded 610 K (at a system pressure of 68 bar) after a 75 minute simulation following the start of core uncovering

  4. CHANGES IN VOLATILE COMPOSITION AND SENSORY PROPERTIES OF VUGAVA WINES AGED IN CROATIA OAK BARRELS

    Directory of Open Access Journals (Sweden)

    Stanka HERJAVEC

    2001-09-01

    Full Text Available Vugava musts were fermented in medium-toasted Croatian barrique barrels (225 L made from Quercus petrea and Q. robur oak wood. The oak species used in this research infl uenced the specifi c change of the aroma structure of Vugava wines. During the age period the increase in the concentration of cis and trans oaklactons, guaiacol, eugenol, furfural and 5-methylfurfural was noted. Wines fermented and aged in Q. petrea barrels have higher concentrations of most volatile phenols compared to wines from Q. robur oak wood. From the organoleptic point of view this study suggested that fermentation and on the lees ageing production method in Croatian oak barrels positively infl uenced the quality of Vugava wines where best results were achieved by use of Q. petrea oak wood.

  5. Early stages in the biogenesis of eukaryotic β-barrel proteins.

    Science.gov (United States)

    Jores, Tobias; Rapaport, Doron

    2017-09-01

    The endosymbiotic organelles mitochondria and chloroplasts harbour, similarly to their prokaryotic progenitors, β-barrel proteins in their outer membrane. These proteins are encoded on nuclear DNA, translated on cytosolic ribosomes and imported into their target organelles by a dedicated machinery. Recent studies have provided insights into the import into the organelles and the membrane insertion of these proteins. Although the cytosolic stages of their biogenesis are less well defined, it is speculated that upon their synthesis, chaperones prevent β-barrel proteins from aggregation and keep them in an import-competent conformation. In this Review, we summarize the current knowledge about the biogenesis of β-barrel proteins, focusing on the early stages from the translation on cytosolic ribosomes to the recognition on the surface of the organelle. © 2017 Federation of European Biochemical Societies.

  6. Performance of the ATLAS Level-1 muon barrel trigger during the Run 2 data taking

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00404546; The ATLAS collaboration

    2018-01-01

    The Level-1 Muon Barrel Trigger is one of the main elements of the event selection of the ATLAS experiment at the Large Hadron Collider. It exploits the Resistive Plate Chambers (RPC) detectors to generate the trigger signal. The RPCs are placed in the barrel region of the ATLAS experiment: they are arranged in three concentric double layers and operate in a strong magnetic toroidal field. RPC detectors cover the pseudo-rapidity range |η| < 1.05 for a total surface of more than 4000 m 2 and about 3600 gas volumes. The Level-1 Muon Trigger in the barrel region allows to select muon candidates according to their transverse momentum and associates them with the correct bunch-crossing. The trigger system is able to take a decision within a latency of about 2 μs. The measurement of the RPC detector efficiencies and the trigger performance during the ATLAS Run-II data taking are here presented.

  7. Distributed Wireless Monitoring System for Ullage and Temperature in Wine Barrels

    Science.gov (United States)

    Zhang, Wenqi; Skouroumounis, George K.; Monro, Tanya M.; Taylor, Dennis K.

    2015-01-01

    This paper presents a multipurpose and low cost sensor for the simultaneous monitoring of temperature and ullage of wine in barrels in two of the most important stages of winemaking, that being fermentation and maturation. The distributed sensor subsystem is imbedded within the bung of the barrel and runs on battery for a period of at least 12 months and costs around $27 AUD for all parts. In addition, software was designed which allows for the remote transmission and easy visual interpretation of the data for the winemaker. Early warning signals can be sent when the temperature or ullage deviates from a winemakers expectations so remedial action can be taken, such as when topping is required or the movement of the barrels to a cooler cellar location. Such knowledge of a wine’s properties or storage conditions allows for a more precise control of the final wine quality. PMID:26266410

  8. Development of the SSTL-300-S1 Composite Imager Barrel Structure

    Science.gov (United States)

    Hamar, Chris; Wood, Trevor; Alsami, Sami; Hallett, Ben

    2014-06-01

    The SSTL-300-S1 is the latest in the family of highly capable SSTL-300 platforms, providing high resolution imagery with all the existing mission performance of the heritage platform. In developing the product, SSTL has had to undertake the development of a composite imager barrel assembly, which forms the payload instrument's primary structure. Working to a nominal schedule of 24 months from requirements definition to structural qualification, the barrel's development philosophy has had to carefully balance the interdependent optical, structural and programmatic requirements. This paper provides a brief summary description of that development.

  9. ATLAS Level-1 Muon Barrel Trigger robustness study at X5 test facility

    CERN Document Server

    Di Mattia, A; Nisati, A; Pastore, F C; Vari, R; Veneziano, Stefano; Aielli, G; Camarri, P; Cardarelli, R; Di Ciaccio, A; Di Simone, A; Liberti, B; Santonico, R

    2004-01-01

    The present paper describes the Level-1 Barrel Muon Trigger performance as expected with the current configuration of the RPC detectors, as designed for the Barrel Muon Spectrometer of ATLAS. Results of a beam test performed at the X5-GIF facility at CERN are presented in order to show the trigger efficiency with different conditions of RPC detection efficiency and several background rates. Small RPC chambers with part of the final trigger electronics are used, while the trigger coincidence logic is applied off-line using a detailed simulation model. copy 2003 Published by Esevier B.V. 3 Refs.

  10. Application of advanced thermal management technologies to the ATLAS SCT barrel module baseboards

    Energy Technology Data Exchange (ETDEWEB)

    Apsimon, R.J. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 OQX (United Kingdom); Batchelor, L.E. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 OQX (United Kingdom); Beck, G.A. [Department of Physics, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Canard, P. [European Laboratory for Particle Physics (CERN), 1211 Geneva 23 (Switzerland); Carter, A.A. [Department of Physics, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom)]. E-mail: a.a.carter@qmul.ac.uk; Carter, J.R. [Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Davis, V.R. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 OQX (United Kingdom); Oliveira, R. de [European Laboratory for Particle Physics (CERN), 1211 Geneva 23 (Switzerland); Gibson, M.D. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 OQX (United Kingdom); Hominal, L. [European Laboratory for Particle Physics (CERN), 1211 Geneva 23 (Switzerland); Ilie, D.M. [Department of Physics, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Ilie, S.D. [European Laboratory for Particle Physics (CERN), 1211 Geneva 23 (Switzerland); Leboube, C.G. [European Laboratory for Particle Physics (CERN), 1211 Geneva 23 (Switzerland); Mistry, J. [Department of Physics, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Morin, J. [Department of Physics, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Morris, J.; Nagai, K. [Department of Physics, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Sexton, I.; Thery, X. [European Laboratory for Particle Physics (CERN), 1211 Geneva 23 (Switzerland); Tyndel, M. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 OQX (United Kingdom)

    2006-09-15

    The paper describes the application of advanced thermal management technologies to the design and production of the barrel module baseboard of the SemiConductor Tracker (SCT) of the ATLAS experiment at the Large Hadron Collider (LHC). The barrel modules contain silicon microstrip sensors and readout ASICs for tracking charged particles, and the baseboard forms the central element of the module, providing both its necessary thermal management and its mechanical structure. The baseboard requirements and specifications are given, and design and fabrication details are described. The properties of the 3000 baseboards successfully produced for the SCT are summarised.

  11. A study of aging effects of barrel Time-Of-Flight system in the BESIII experiment

    Science.gov (United States)

    Liu, Huan-Huan; Sun, Sheng-Sen; Fang, Shuang-Shi; Wu, Zhi; Dai, Hong-Liang; Heng, Yue-Kun; Zhou, Ming; Deng, Zi-Yan; Liu, Huai-Min

    2018-02-01

    The Time-Of-Flight system consisting of plastic scintillation counters plays an important role for particle identification in the BESIII experiment at the BEPCII double ring e+e- collider. Degradation of the detection efficiency of the barrel TOF system has been observed since the start of physical data taking and this effect has triggered intensive and systematic studies about aging effects of the detector. The aging rates of the attenuation lengths and relative gains are obtained based on the data acquired in past several years. This study is essential for ensuring an extended operation of the barrel TOF system in optimal conditions.

  12. Growth of single-crystal W whiskers during humid H2/N2 reduction of Ni, Fe-Ni, and Co-Ni doped tungsten oxide

    International Nuclear Information System (INIS)

    Wang Shiliang; He Yuehui; Zou Jou; Wang Yong; Huang Han

    2009-01-01

    Numbers of W whiskers were obtained by reducing Ni, Ni-Fe, and Ni-Co doped tungsten oxide in a mixed atmosphere of humid H 2 and N 2 . The phases and morphologies of the reduction products were characterized by XRD and SEM. Intensive TEM and EDS analyses showed that the obtained whiskers were W single crystals which typical have alloyed particles (Ni-W, Fe-Ni, or Co-Ni-W) at the growth tips. The formed W whiskers were presumed to be induced by the alloyed particles. Our experimental results revealed that, during the reduction process of tungsten oxide, the pre-reduced Ni, Fe-Ni, or Co-Ni particles not only served as nucleation aids for the initial growth of W phase from W oxide but also played the roles of catalysts during the reductive decomposition of gaseous WO 2 (OH) 2 .

  13. Conversion of wood flour/SiO2/phenolic composite to porous SiC ceramic containing SiC whiskers

    Directory of Open Access Journals (Sweden)

    Li Zhong

    2013-01-01

    Full Text Available A novel wood flour/SiO2/phenolic composite was chosen to be converted into porous SiC ceramic containing SiC whiskers via carbothermal reduction. At 1550°C the composite is converted into porous SiC ceramic with pore diameters of 10~40μm, and consisting of β-SiC located at the position of former wood cell walls. β-SiC wire-like whiskers of less than 50 nm in diameter and several tens to over 100 μm in length form within the pores. The surface of the resulting ceramic is coated with β-SiC necklace-like whiskers with diameters of 1~2μm.

  14. Temperature-dependent transformation from whisker- to nanoparticle-strengthened composite interface in the Al{sub 2}O{sub 3}/Ag-based alloy system and mechanical properties of the joints

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yifeng; Cao, Jian, E-mail: cao_jian@hit.edu.cn; Wang, Zhijie; Chen, Zhe; Song, Xiaoguo; Feng, Jicai

    2015-11-15

    Al{sub 4}B{sub 2}O{sub 9}-whisker-coated Al{sub 2}O{sub 3} ceramics were bonded by AgCu–4.5 wt.%Ti alloy in vacuum. The microstructure of the whisker-coated Al{sub 2}O{sub 3} joints was investigated by scanning electron microscopy, transmission electron microscopy and X-ray diffraction. A continuous (Cu,Al){sub 3}Ti{sub 3}O layer formed against the alloy at lower bonding temperatures, and a complex transition zone bordering the whiskers was observed, which consisted of Ag nanoparticles, titanium oxides, TiB{sub 2}, (Cu,Al){sub 3}Ti{sub 3}O nanoparticles and possible Ag{sub 3}Al. As the bonding temperature increased, the Al{sub 2}O{sub 3}/AgCuTi interface was found to transform from whisker- to nanoparticle-strengthened composite region. Bend test results revealed that both the whiskers grown on Al{sub 2}O{sub 3} and the dispersive nanoscale products in the alloy played positive roles in improving the joint properties. The maximum bend strength of the whisker-coated Al{sub 2}O{sub 3} joints was 313 MPa at the bonding temperature of 820 °C. - Highlights: • Al{sub 4}B{sub 2}O{sub 9}-whisker-coated Al{sub 2}O{sub 3} ceramics were bonded by AgCu–4.5 wt.%Ti alloy in vacuum. • Microstructures of whisker-coated Al{sub 2}O{sub 3} joints were investigated in detail. • Both whiskers and the dispersive nanoscale products can improve the joint properties. • The maximum bend strength of the whisker-coated Al{sub 2}O{sub 3} joints was 313 MPa.

  15. Temperature-dependent transformation from whisker- to nanoparticle-strengthened composite interface in the Al2O3/Ag-based alloy system and mechanical properties of the joints

    International Nuclear Information System (INIS)

    Wang, Yifeng; Cao, Jian; Wang, Zhijie; Chen, Zhe; Song, Xiaoguo; Feng, Jicai

    2015-01-01

    Al 4 B 2 O 9 -whisker-coated Al 2 O 3 ceramics were bonded by AgCu–4.5 wt.%Ti alloy in vacuum. The microstructure of the whisker-coated Al 2 O 3 joints was investigated by scanning electron microscopy, transmission electron microscopy and X-ray diffraction. A continuous (Cu,Al) 3 Ti 3 O layer formed against the alloy at lower bonding temperatures, and a complex transition zone bordering the whiskers was observed, which consisted of Ag nanoparticles, titanium oxides, TiB 2 , (Cu,Al) 3 Ti 3 O nanoparticles and possible Ag 3 Al. As the bonding temperature increased, the Al 2 O 3 /AgCuTi interface was found to transform from whisker- to nanoparticle-strengthened composite region. Bend test results revealed that both the whiskers grown on Al 2 O 3 and the dispersive nanoscale products in the alloy played positive roles in improving the joint properties. The maximum bend strength of the whisker-coated Al 2 O 3 joints was 313 MPa at the bonding temperature of 820 °C. - Highlights: • Al 4 B 2 O 9 -whisker-coated Al 2 O 3 ceramics were bonded by AgCu–4.5 wt.%Ti alloy in vacuum. • Microstructures of whisker-coated Al 2 O 3 joints were investigated in detail. • Both whiskers and the dispersive nanoscale products can improve the joint properties. • The maximum bend strength of the whisker-coated Al 2 O 3 joints was 313 MPa.

  16. Reproductive success of Whiskered Tern Chlidonias hybrida in eastern Spain in relation to water level variation.

    Science.gov (United States)

    Ortiz Lledó, Álvaro; Vidal Mateo, Javier; Urios Moliner, Vicente

    2018-01-01

    A study on the Whiskered Tern Chlidonias hybrida was carried out between 2002 and 2009 in wetlands of eastern Spain to evaluate how water level fluctuation affects its reproductive success (hatching, fledgling and breeding success). This species is catalogued as Vulnerable in Spain and has an unfavorable conservation status in Europe. Our study includes 18 sampling areas from five wetlands, covering a total of 663 nests, 1,618 eggs, 777 nestlings and 225 fledglings. The colonies were visited at least twice per week in breeding period. The number of eggs and/or nestlings present in each nest were annotated each time the colonies were visited with the aim to compare the evolution of these parameters with time. Hatching success was calculated as the proportion of egg that hatched successfully. Fledgling success and breeding success were calculated as the proportion of chicks that fledged successfully and the proportion of eggs that produced fledglings. We used the Kruskal-Wallis test to analyze the differences in the dependent variables hatching, fledgling and breeding success among the wetlands and the sampling areas. We explored the relationship between the different reproductive success with the average fluctuation rate and the anchoring depth of nests, using statistics of the linear regression. It was observed that the reproductive success varied significantly in the interaction among the different categories of water level fluctuation and the different areas (using the Kruskal-Wallis test). Our records showed that pronounced variations in water level destroyed several nests, which affected the Whiskered Tern reproductive success. Considering all events that occurred in 18 areas, the mean (±SD) of nests, eggs and nestlings that were lost after water level fluctuations were of 25.60 ± 21.79%, 32.06 ± 27.58% and 31.91 ± 21.28% respectively, also including the effects of rain and predation. Unfavorable climatic events, such as strong wind, rain or hail, also

  17. Reproductive success of Whiskered Tern Chlidonias hybrida in eastern Spain in relation to water level variation

    Directory of Open Access Journals (Sweden)

    Álvaro Ortiz Lledó

    2018-04-01

    Full Text Available Background A study on the Whiskered Tern Chlidonias hybrida was carried out between 2002 and 2009 in wetlands of eastern Spain to evaluate how water level fluctuation affects its reproductive success (hatching, fledgling and breeding success. This species is catalogued as Vulnerable in Spain and has an unfavorable conservation status in Europe. Methods Our study includes 18 sampling areas from five wetlands, covering a total of 663 nests, 1,618 eggs, 777 nestlings and 225 fledglings. The colonies were visited at least twice per week in breeding period. The number of eggs and/or nestlings present in each nest were annotated each time the colonies were visited with the aim to compare the evolution of these parameters with time. Hatching success was calculated as the proportion of egg that hatched successfully. Fledgling success and breeding success were calculated as the proportion of chicks that fledged successfully and the proportion of eggs that produced fledglings. We used the Kruskal–Wallis test to analyze the differences in the dependent variables hatching, fledgling and breeding success among the wetlands and the sampling areas. We explored the relationship between the different reproductive success with the average fluctuation rate and the anchoring depth of nests, using statistics of the linear regression. Results It was observed that the reproductive success varied significantly in the interaction among the different categories of water level fluctuation and the different areas (using the Kruskal–Wallis test. Our records showed that pronounced variations in water level destroyed several nests, which affected the Whiskered Tern reproductive success. Considering all events that occurred in 18 areas, the mean (±SD of nests, eggs and nestlings that were lost after water level fluctuations were of 25.60 ± 21.79%, 32.06 ± 27.58% and 31.91 ± 21.28% respectively, also including the effects of rain and predation. Discussion Unfavorable

  18. Tribo-performance of epoxy hybrid composites reinforced with carbon fibers and potassium titanate whiskers

    Science.gov (United States)

    Suresha, B.; Harshavardhan, B.; Ravishankar, R.

    2018-04-01

    The present investigation deals with the fabrication and characterization of epoxy reinforced with bidirectional carbon fiber mat (CF/Ep) and filled with 2.5, 5 and 7.5 wt% potassium titanate whiskers (PTw) composites. The effect of PTw loading on hardness, tensile properties and dry sliding wear behaviour of CF/Ep composite were carefully investigated in expectation of providing valuable information for the application of hybrid CF/Ep composites. Results indicated that the incorporation of PTw actually improved the hardness, tensile strength and tensile modulus of CF/Ep composites. Meanwhile, the specific wear rate of CF/Ep filled by 5 wt % PTw reached to 6.3× 10-14 m3/N-m, which is 41% lower than that of CF/Ep composite at the same dry sliding condition. It also seen that the fiber and filler worked synergistically to enhance the wear resistance. Further, for all composites the friction coefficient increases with increase in load and sliding velocity. However, PTw reinforced CF/Ep exhibited considerably higher coefficient of friction compared to unfilled ones, while PTw filler loading of 5 wt% was effective in reducing the specific wear rate of CF/Ep composite. The carbon fiber carried the applied load between the contact surfaces and protected the epoxy from severe abrasion of the counterface. At the same time, the exposed PTw out of the epoxy matrix around the fiber inhibited the direct scraping between the fiber and counterface so that the fibers could be less directly impacted during the subsequent wear process and they were protected from severe damage.

  19. Rapid disinhibition by adjustment of PV intrinsic excitability during whisker map plasticity in mouse S1.

    Science.gov (United States)

    Gainey, Melanie A; Aman, Joseph W; Feldman, Daniel E

    2018-04-20

    Rapid plasticity of layer (L) 2/3 inhibitory circuits is an early step in sensory cortical map plasticity, but its cellular basis is unclear. We show that, in mice of either sex, 1 day whisker deprivation drives rapid loss of L4-evoked feedforward inhibition and more modest loss of feedforward excitation in L2/3 pyramidal (PYR) cells, increasing E-I conductance ratio. Rapid disinhibition was due to reduced L4-evoked spiking by L2/3 parvalbumin (PV) interneurons, caused by reduced PV intrinsic excitability. This included elevated PV spike threshold, associated with an increase in low-threshold, voltage activated delayed rectifier (presumed Kv1) and A-type potassium currents. Excitatory synaptic input and unitary inhibitory output of PV cells were unaffected. Functionally, the loss of feedforward inhibition and excitation were precisely coordinated in L2/3 PYR cells, so that peak feedforward synaptic depolarization remained stable. Thus, rapid plasticity of PV intrinsic excitability offsets early weakening of excitatory circuits to homeostatically stabilize synaptic potentials in PYR cells of sensory cortex. SIGNIFICANCE STATEMENT Inhibitory circuits in cerebral cortex are highly plastic, but the cellular mechanisms and functional importance of this plasticity are incompletely understood. We show that brief (1-day) sensory deprivation rapidly weakens parvalbumin (PV) inhibitory circuits by reducing the intrinsic excitability of PV neurons. This involved a rapid increase in voltage-gated potassium conductances that control near-threshold spiking excitability. Functionally, the loss of PV-mediated feedforward inhibition in L2/3 pyramidal cells was precisely balanced with the separate loss of feedforward excitation, resulting in a net homeostatic stabilization of synaptic potentials. Thus, rapid plasticity of PV intrinsic excitability implements network-level homeostasis to stabilize synaptic potentials in sensory cortex. Copyright © 2018 the authors.

  20. Synthesis, characterization, antimicrobial activity and mechanism of a novel hydroxyapatite whisker/nano zinc oxide biomaterial

    International Nuclear Information System (INIS)

    Yu, Jian; Zhang, Wenyun; Li, Yang; Wang, Gang; Yang, Lidou; Jin, Jianfeng; Chen, Qinghua; Huang, Minghua

    2015-01-01

    Postoperative infections remain a risk factor that leads to failures in oral and maxillofacial artificial bone transplantation. This study aimed to synthesize and evaluate a novel hydroxyapatite whisker (HAPw) / nano zinc oxide (n-ZnO) antimicrobial bone restorative biomaterial. A scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and x-ray diffraction (XRD) were employed to characterize and analyze the material. Antibacterial capabilities against Staphylococcus aureus, Escherichia coli, Candida albicans and Streptococcus mutans were determined by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), and kinetic growth inhibition assays were performed under darkness and simulated solar irradiation. The mode of antibiotic action was observed by transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM). The MIC and MBC were 0.078–1.250 mg ml −1 and 0.156–2.500 mg ml −1 , respectively. The inhibitory function on the growth of the microorganisms was achieved even under darkness, with gram-positive bacteria found to be more sensitive than gram-negative, and enhanced antimicrobial activity was exhibited under simulated solar excitation compared to darkness. TEM and CLSM images revealed a certain level of bacterial cell membrane destruction after treatment with 1 mg ml −1 of the material for 12 h, causing the leakage of intracellular contents and bacteria death. These results suggest favorable antibiotic properties and a probable mechanism of the biomaterial for the first time, and further studies are needed to determine its potential application as a postoperative anti-inflammation method in bone transplantation. (paper)

  1. Synthesis, characterization, antimicrobial activity and mechanism of a novel hydroxyapatite whisker/nano zinc oxide biomaterial.

    Science.gov (United States)

    Yu, Jian; Zhang, Wenyun; Li, Yang; Wang, Gang; Yang, Lidou; Jin, Jianfeng; Chen, Qinghua; Huang, Minghua

    2014-12-23

    Postoperative infections remain a risk factor that leads to failures in oral and maxillofacial artificial bone transplantation. This study aimed to synthesize and evaluate a novel hydroxyapatite whisker (HAPw) / nano zinc oxide (n-ZnO) antimicrobial bone restorative biomaterial. A scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and x-ray diffraction (XRD) were employed to characterize and analyze the material. Antibacterial capabilities against Staphylococcus aureus, Escherichia coli, Candida albicans and Streptococcus mutans were determined by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), and kinetic growth inhibition assays were performed under darkness and simulated solar irradiation. The mode of antibiotic action was observed by transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM). The MIC and MBC were 0.078-1.250 mg ml(-1) and 0.156-2.500 mg ml(-1), respectively. The inhibitory function on the growth of the microorganisms was achieved even under darkness, with gram-positive bacteria found to be more sensitive than gram-negative, and enhanced antimicrobial activity was exhibited under simulated solar excitation compared to darkness. TEM and CLSM images revealed a certain level of bacterial cell membrane destruction after treatment with 1 mg ml(-1) of the material for 12 h, causing the leakage of intracellular contents and bacteria death. These results suggest favorable antibiotic properties and a probable mechanism of the biomaterial for the first time, and further studies are needed to determine its potential application as a postoperative anti-inflammation method in bone transplantation.

  2. In vitro corrosion and cytocompatibility properties of nano-whisker hydroxyapatite coating on magnesium alloy for bone tissue engineering applications.

    Science.gov (United States)

    Yang, Huawei; Yan, Xueyu; Ling, Min; Xiong, Zuquan; Ou, Caiwen; Lu, Wei

    2015-03-17

    We report here the successful fabrication of nano-whisker hydroxyapatite (nHA) coatings on Mg alloy by using a simple one-step hydrothermal process in aqueous solution. The nHA coating shows uniform structure and high crystallinity. Results indicate that nHA coating is promising for improving the in vitro corrosion and cytocompatibility properties of Mg-based implants and devices for bone tissue engineering. In addition, the simple hydrothermal deposition method used in the current study is also applicable to substrates with complex shapes or surface geometries.

  3. In Vitro Corrosion and Cytocompatibility Properties of Nano-Whisker Hydroxyapatite Coating on Magnesium Alloy for Bone Tissue Engineering Applications

    Directory of Open Access Journals (Sweden)

    Huawei Yang

    2015-03-01

    Full Text Available We report here the successful fabrication of nano-whisker hydroxyapatite (nHA coatings on Mg alloy by using a simple one-step hydrothermal process in aqueous solution. The nHA coating shows uniform structure and high crystallinity. Results indicate that nHA coating is promising for improving the in vitro corrosion and cytocompatibility properties of Mg-based implants and devices for bone tissue engineering. In addition, the simple hydrothermal deposition method used in the current study is also applicable to substrates with complex shapes or surface geometries.

  4. Whiskers de fibra de sisal obtidos sob diferentes condições de hidrólise ácida: efeito do tempo e da temperatura de extração Whiskers from sisal fibers obtained under different acid hydrolysis conditions: effect of time and temperature of extraction

    Directory of Open Access Journals (Sweden)

    Kelcilene B. R. Teodoro

    2011-01-01

    Full Text Available Neste trabalho, os efeitos de diferentes condições de tempo e temperatura usados para a preparação de whiskers de sisal foram investigados com o objetivo de se determinar a influência destes parâmetros experimentais na morfologia, cristalinidade e estabilidade térmica dos materiais preparados. A obtenção dos whiskers deu-se após o pré-branqueamento da fibra de sisal com solução alcalina de peróxido de hidrogênio. A fibra branqueada foi submetida ao processo de hidrólise com solução de ácido sulfúrico 60% (m/m sob três diferentes condições de temperatura e tempos de extração: 45 °C e 60 minutos (WS45_60; 45 °C e 75 minutos (WS45_75 e 60 °C e 30 minutos (WS60_30. Os whiskers foram caracterizados quanto à morfologia por microscopia eletrônica de transmissão (MET, quanto à cristalinidade (DRX, carga superficial (potencial zeta , teor de enxofre (análise elementar e quanto à estabilidade térmica por termogravimetria (TGA. Os resultados mostraram que os whiskers de sisal apresentaram comprimento e diâmetro médios e 210 nm e 5 nm respectivamente. Devido à alta aglomeração dos whiskers, diferenças relativas às características dimensionais não puderam ser determinadas. Os resultados obtidos revelaram uma forte dependência da cristalinidade final dos whiskers com a temperatura e tempo de extração. O uso de temperatura mais alta (60 °C associado a um menor tempo de extração (30 minutos resulta em whiskers com boa estabilidade térmica (235 °C, maior cristalinidade e sem o comprometimento da estrutura cristalina da celulose.In this work, the effects of different conditions of time and temperature, used for the preparation of whiskers from sisal, were investigated to determine the influence of experimental parameters on morphology, crystallinity and thermal stability of materials prepared. The whiskers were obtained after the bleaching of sisal raw fiber with a solution of hydrogen peroxide alkaline. The

  5. 27 CFR 25.160 - Tax adjustment for brewers who produce more than 2,000,000 barrels of beer.

    Science.gov (United States)

    2010-04-01

    ... who produce more than 2,000,000 barrels of beer. 25.160 Section 25.160 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS BEER Tax on Beer Determination of Tax § 25.160 Tax adjustment for brewers who produce more than 2,000,000 barrels of beer. Each...

  6. Start of Final Assembly of the CMS Barrel Yoke on schedule at P5 the 1st august, 2000. I

    CERN Multimedia

    Hubert Gerwig, CERN/ EP-CMI

    2000-01-01

    The Barrel Yoke and the vacuumtank weigh 6500 tonnes. The barrel Yoke consists of 5 rings eacu one weighing 1200 tonnes. The vacuum tank is a stainless steel structure weighing 270 tonnes (length = 13 m , outer diamter 7.6 m) The final assembly of these items will take approximately 1 year from now on.

  7. Involvement and necessity of the Cpx regulon in the event of aberrant β-barrel outer membrane protein assembly

    Science.gov (United States)

    Gerken, Henri; Leiser, Owen P.; Bennion, Drew; Misra, Rajeev

    2010-01-01

    Summary The Cpx and σE regulons help maintain outer membrane integrity; the Cpx pathway monitors the biogenesis of cell surface structures, such as pili, while the σE pathway monitors the biogenesis of β-barrel outer membrane proteins (OMPs). In this study we revealed the importance of the Cpx regulon in the event of β-barrel OMP mis-assembly, by utilizing mutants expressing either a defective β-barrel OMP assembly machinery (Bam) or assembly defective β-barrel OMPs. Analysis of specific mRNAs showed that ΔcpxR bam double mutants failed to induce degP expression beyond the wild type level, despite activation of the σE pathway. The synthetic conditional lethal phenotype of ΔcpxR in mutant Bam or β-barrel OMP backgrounds was reversed by wild type DegP expressed from a heterologous plasmid promoter. Consistent with the involvement of the Cpx regulon in the event of aberrant β-barrel OMP assembly, the expression of cpxP, the archetypal member of the cpx regulon, was upregulated in defective Bam backgrounds or in cells expressing a single assembly-defective β-barrel OMP species. Together, these results showed that both the Cpx and σE regulons are required to reduce envelope stress caused by aberrant β-barrel OMP assembly, with the Cpx regulon principally contributing by controlling degP expression. PMID:20487295

  8. Performance of the SLD Barrel CRID during the 1992 physics data run

    International Nuclear Information System (INIS)

    Abe, K.; Hasegawa, K.; Hasegawa, Y.; Iwasaki, Y.; Suekane, F.; Toge, N.; Yuta, H.; Baird, K.; Jacques, P.; Kalelkar, M.; Plano, R.; Stamer, P.; Word, G.; Bean, A.; Caldwell, D.O.; Duboscq, J.; Huber, J.; Lu, A.; Mathys, L.; McHugh, S.; Yellin, S.; Ben-David, R.; Manly, S.; Snyder, J.; Turk, J.; Cavalli-Sforza, M.; Colye, P.; Coyne, D.; Liu, X.; Williams, D.A.; Coller, J.; Shank, J.T.; Whitaker, J.S.; d'Oliveira, A.; Johnson, R.A.; Martinez, J.; Meadows, B.; Nussbaum, M.; Santha, A.K.S.; Sokoloff, M.D.; Stockdale, I.; Wilson, R.J.

    1992-11-01

    The SLD Barrel Cherenkov Ring Imaging Detector was fully operational in the 1992 physics data run. The electron drift velocity and magnetic field deflection of electron trajectories have been measured. Cherenkov rings have been observed from both the liquid and gas radiators. The number and the resolution of the angle of Cherenkov photons have been measured to be approximately equal to design specifications

  9. Construction and Performance of the ATLAS SCT Barrels and Cosmic Tests

    CERN Document Server

    Demirkoz, Bilge Melahat

    2007-01-01

    ATLAS is a multi-purpose detector for the LHC and will detect proton-proton collisions with center of mass energy of $14$TeV. Part of the central inner detector, the Semi-Conductor Tracker (SCT) barrels, were assembled and tested at Oxford University and later integrated at CERN with the TRT (Transition Radiation Tracker) barrel. The barrel SCT is composed of 4 layers of silicon strip modules with two sensor layers with $80 \\mu$m channel width. The design of the modules and the barrels has been optimized for low radiation length while maintaining mechanical stability, bringing services to the detector, and ensuring a cold and dry environment. The high granularity, high detector efficiency and low noise occupancy ($ < 5 \\times 10^{-4}$) of the SCT will enable ATLAS to have an efficient pattern recognition capability. Due to the binary nature of the SCT read-out, a stable read-out system and the calibration system is of critical importance. SctRodDaq is the online software framework for the calibration and a...

  10. Construction and test of the final CMS Barrel Drift Tube Muon Chamber prototype

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Benitez, M.; Alberdi, J.; Arneodo, M.; Banicz, K.; Benettoni, M.; Benvenuti, A.; Bethke, S.; Cerrada, M. E-mail: cerrada@ciemat.es; Cirio, R.; Colino, N.; Conti, E.; Dallavalle, M.; Daniel, M.; Dattola, D.; Daudo, F.; De Giorgi, M.; Dosselli, U.; Fanfani, A.; Fanin, C.; Fouz, M.C.; Gasparini, F.; Gasparini, U.; Giacomelli, P.; Giordano, V.; Gonella, F.; Grandi, C.; Guaita, P.; Guerzoni, M.; Lacaprara, S.; Lippi, I.; Marcellini, S.; Marin, J.; Martinelli, R.; Maselli, S.; Meneguzzo, A.; Migliore, E.; Mocholi, J.; Monaco, V.; Montanari, A.; Montanari, C.; Odorici, F.; Oller, J.C.; Paoletti, S.; Passaseo, M.; Pegoraro, M.; Peroni, C.; Puerta, J.; Reithler, H.; Romero, A.; Romero, L.; Ronchese, P.; Rossi, A.M.; Rovelli, T.; Sacchi, R.; Salicio, J.M.; Staiano, A.; Steinbeck, T.; Torassa, E.; Travaglini, R.; Ventura, L.; Ventura, S.; Vitelli, A.; Voetee, F.; Wegner, M.; Willmott, C.; Zotto, P.; Zumerle, G

    2002-03-21

    A prototype of the CMS Barrel Muon Detector incorporating all the features of the final chambers was built using the mass production assembly procedures and tools. The performance of this prototype was studied in a muon test beam at CERN and the results obtained are presented in this paper.

  11. Phenolic Composition and Related Properties of Aged Wine Spirits: Influence of Barrel Characteristics. A Review

    Directory of Open Access Journals (Sweden)

    Sara Canas

    2017-11-01

    Full Text Available The freshly distilled wine spirit has a high concentration of ethanol and many volatile compounds, but is devoid of phenolic compounds other than volatile phenols. Therefore, an ageing period in the wooden barrel is required to attain sensory fullness and high quality. During this process, several phenomena take place, namely the release of low molecular weight phenolic compounds and tannins from the wood into the wine spirit. Research conducted over the last decades shows that they play a decisive role on the physicochemical characteristics and relevant sensory properties of the beverage. Their contribution to the antioxidant activity has also been emphasized. Besides, some studies show the modulating effect of the ageing technology, involving different factors such as the barrel features (including the wood botanical species, those imparted by the cooperage technology, and the barrel size, the cellar conditions, and the operations performed, on the phenolic composition and related properties of the aged wine spirit. This review aims to summarize the main findings on this topic, taking into account two featured barrel characteristics—the botanical species of the wood and the toasting level.

  12. Inference of core barrel motion from neutron noise spectral density. [PWR

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, J.C.; Shahrokhi, F.; Kryter, R.C.

    1977-03-15

    A method was developed for inference of core barrel motion from the following statistical descriptors: cross-power spectral density, autopower spectral density, and amplitude probability density. To quantify the core barrel motion in a typical pressurized water reactor (PWR), a scale factor was calculated in both one- and two-dimensional geometries using forward, variational, and perturbation methods of discrete ordinates neutron transport. A procedure for selection of the proper frequency band limits for the statistical descriptors was developed. It was found that although perturbation theory is adequate for the calculation of the scale factor, two-dimensional geometric effects are important enough to rule out the use of a one-dimensional approximation for all but the crudest calculations. It was also found that contributions of gamma rays can be ignored and that the results are relatively insensitive to the cross-section set employed. The proper frequency band for the statistical descriptors is conveniently determined from the coherence and phase information from two ex-core power range neutron monitors positioned diametrically across the reactor vessel. Core barrel motion can then be quantified from the integral of the band-limited cross-power spectral density of two diametrically opposed ex-core monitors or, if the coherence between the pair is greater than or equal to 0.7, from a properly band-limited amplitude probability density function. Wide-band amplitude probability density functions were demonstrated to yield erroneous estimates for the magnitude of core barrel motion.

  13. Cosmic tests and performance of the ATLAS SemiConductor Tracker Barrels

    International Nuclear Information System (INIS)

    Demirkoez, Bilge M.

    2007-01-01

    ATLAS is a multi-purpose particle detector for the LHC and will detect proton collisions with center of mass energy of 14TeV. Part of the central inner detector, the SemiConductor Tracker (SCT) barrel, is now fully integrated with the Transition Radiation Tracker (TRT) barrel. The SCT module performance has been measured after module production, after macro-assembly of modules onto barrels, after arrival at CERN and again partially after integration with the TRT. The module noise average per channel has been stable and is 4.5x10 -5 , well below the design specification of 5x10 -4 . There is no evidence for common mode noise problems and 99.8% of the 3.2 million channels of the SCT barrels are functional. The cosmics running of the SCT and TRT was the first large scale test of the physics mode of the SCT online software framework. A large sector, 468 SCT modules, has been timed in and read out during the cosmic tests. Tracks have been reconstructed through the SCT and the TRT sectors. Present residuals from tracks (without alignment) are better than the specified building tolerances of the SCT

  14. Learning-Dependent Plasticity of the Barrel Cortex Is Impaired by Restricting GABA-Ergic Transmission.

    Science.gov (United States)

    Posluszny, Anna; Liguz-Lecznar, Monika; Turzynska, Danuta; Zakrzewska, Renata; Bielecki, Maksymilian; Kossut, Malgorzata

    2015-01-01

    Experience-induced plastic changes in the cerebral cortex are accompanied by alterations in excitatory and inhibitory transmission. Increased excitatory drive, necessary for plasticity, precedes the occurrence of plastic change, while decreased inhibitory signaling often facilitates plasticity. However, an increase of inhibitory interactions was noted in some instances of experience-dependent changes. We previously reported an increase in the number of inhibitory markers in the barrel cortex of mice after fear conditioning engaging vibrissae, observed concurrently with enlargement of the cortical representational area of the row of vibrissae receiving conditioned stimulus (CS). We also observed that an increase of GABA level accompanied the conditioning. Here, to find whether unaltered GABAergic signaling is necessary for learning-dependent rewiring in the murine barrel cortex, we locally decreased GABA production in the barrel cortex or reduced transmission through GABAA receptors (GABAARs) at the time of the conditioning. Injections of 3-mercaptopropionic acid (3-MPA), an inhibitor of glutamic acid decarboxylase (GAD), into the barrel cortex prevented learning-induced enlargement of the conditioned vibrissae representation. A similar effect was observed after injection of gabazine, an antagonist of GABAARs. At the behavioral level, consistent conditioned response (cessation of head movements in response to CS) was impaired. These results show that appropriate functioning of the GABAergic system is required for both manifestation of functional cortical representation plasticity and for the development of a conditioned response.

  15. Tob38, a novel essential component in the biogenesis of β-barrel proteins of mitochondria

    Science.gov (United States)

    Waizenegger, Thomas; Habib, Shukry J; Lech, Maciej; Mokranjac, Dejana; Paschen, Stefan A; Hell, Kai; Neupert, Walter; Rapaport, Doron

    2004-01-01

    Insertion of β-barrel proteins into the outer membrane of mitochondria is mediated by the TOB complex. Known constituents of this complex are Tob55 and Mas37. We identified a novel component, Tob38. It is essential for viability of yeast and the function of the TOB complex. Tob38 is exposed on the surface of the mitochondrial outer membrane. It interacts with Mas37 and Tob55 and is associated with Tob55 even in the absence of Mas37. The Tob38–Tob55 core complex binds precursors of β-barrel proteins and facilitates their insertion into the outer membrane. Depletion of Tob38 results in strongly reduced levels of Tob55 and Mas37 and the residual proteins no longer form a complex. Tob38-depleted mitochondria are deficient in the import of β-barrel precursor proteins, but not of other outer membrane proteins or proteins of other mitochondrial subcompartments. We conclude that Tob38 has a crucial function in the biogenesis of β-barrel proteins of mitochondria. PMID:15205677

  16. Experimental study of the single electron response of the DELPHI Barrel RICH MWPC's

    International Nuclear Information System (INIS)

    Dracos, M.

    1989-01-01

    We present herewith the results of an experimental study of the multiwire proportionnal chambers (MWPC's) used in the Barrel RICH particle identifier of the LEP-DELPHI experiment. Emphasis is given to the problem of detection efficiency and to the measurements of the charge induced by a single photoelectron

  17. Dependence of Oak-Related Volatile Compounds on the Physicochemical Characteristics of Barrel-Aged Wines

    Directory of Open Access Journals (Sweden)

    Pedro Rodríguez-Rodríguez

    2012-01-01

    Full Text Available This paper focuses on the effect of some of the physicochemical characteristics of wines such as volatile acidity, titratable acidity, pH, free SO2 and alcohol content on the accumulation of oak-related volatile compounds in barrel-aged wines, in order to give more light on the contradictory results found by other authors in this respect. For this, three different single variety wines were aged for twelve months in barrels with the same characteristics (same cooperage, wood origin, toasting level and volume, repeating the experiment in two consecutive years. Our results show that the percentage of wine alcohol and its titratable acidity positively correlated with the final concentration of vanillin and guaiacyl compounds in the oak-matured wines and negatively with the cis- and trans-β-methyl-γ-octalactone concentration. Therefore, when studying the effect of oak barrel variables (oak origin and seasoning, size of the barrel, number of uses, etc. on the concentration of oak-related volatile compounds in wine, the effect of the physicochemical variables of the wine, especially titratable acidity and alcohol content, should also be taken into account since the final wine aroma composition will also depend on these characteristics.

  18. 33 CFR 135.103 - Levy and payment of barrel fee on OCS oil.

    Science.gov (United States)

    2010-07-01

    ... SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OFFSHORE OIL POLLUTION COMPENSATION FUND Levy of Fees § 135.103 Levy and payment of barrel fee on OCS oil. (a) A fee of $.03 per... paragraph (a) of this section applies whenever the unobligated Fund balance is less than $200,000,000. (d...

  19. Test of the wire ageing induced by radiation for the CMS barrel muon chamber

    CERN Document Server

    Conti, Enrico

    2000-01-01

    We have carried out laboratory test to measure the ageing of a wire tube due to pollutant outgassed by various materials. The tested materials are those used in the muon barrel drift tubes. An X-ray gun irradiated the test tube to accelerate the ageing process. No ageing effect has been measured for a period equivalent to 10 years of operation at LHC.

  20. Performance analysis for the CALIFA Barrel calorimeter of the R{sup 3}B experiment

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez-Pol, H., E-mail: hector.alvarez@usc.es [Dpt. de Física de Partículas, Universidade de Santiago de Compostela, E-15782, Santiago de Compostela (Spain); Ashwood, N. [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Aumann, T. [Institut für Kernphysik, Technische Universität Darmstadt, D-64289 Darmstadt (Germany); GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Bertini, D. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Cabanelas, P. [Dpt. de Física de Partículas, Universidade de Santiago de Compostela, E-15782, Santiago de Compostela (Spain); Casarejos, E. [Universidade de Vigo, E-36310 Vigo (Spain); Cederkall, J. [Department of Physics, Lund University, SE 221 00 Lund (Sweden); Cortina-Gil, D.; Díaz Fernández, P.; Duran, I. [Dpt. de Física de Partículas, Universidade de Santiago de Compostela, E-15782, Santiago de Compostela (Spain); Fiori, E. [ExtreMe Matter Institute EMMI and Research Division, GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Frankfurt Institute for Advanced Studies, D-60438 Frankfurt am Main (Germany); Galaviz, D. [Centro de Fsica Nuclear da Universidade de Lisboa, 1649-003 Lisbon (Portugal); Labiche, M. [STFC Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Nacher, E. [Instituto de Estructura de la Materia CSIC, Madrid (Spain); Pietras, B. [Dpt. de Física de Partículas, Universidade de Santiago de Compostela, E-15782, Santiago de Compostela (Spain); and others

    2014-12-11

    The CALIFA calorimeter is an advanced detector for gamma rays and light charged particles, accordingly optimized for the demanding requirements of the physics programme proposed for the R{sup 3}B facility at FAIR. The multipurpose character of CALIFA is required to fulfil challenging demands in energy resolution (5–6% at 1 MeV for gamma rays) and efficiency. Charged particles, e.g. protons of energies up to 320 MeV in the Barrel section, should also be identified with an energy resolution better to 1%. CALIFA is divided into two well-separated sections: a “Forward EndCap” and a cylindrical “Barrel” covering an angular range from 43.2° to 140.3°. The Barrel section, based on long CsI(Tl) pyramidal frustum crystals coupled to large area avalanche photodiodes (LAAPDs), attains the requested high efficiency for calorimetric purposes. The construction of the CALIFA Demonstrator, comprising 20% of the total detector, has already been initiated, and commissioning experiments are expected for 2014. The assessment of the capabilities and expected performance of the detector elements is a crucial step in their design, along with the prototypes evaluation. For this purpose, the Barrel geometry has been carefully implemented in the simulation package R3BRoot, including easily variable thicknesses of crystal wrapping and carbon fibre supports. A complete characterization of the calorimeter response (including efficiency, resolution, evaluation of energy and reconstruction losses) under different working conditions, with several physics cases selected to probe the detector performance over a wide range of applications, has been undertaken. Prototypes of different sections of the CALIFA Barrel have been modeled and their responses have been evaluated and compared with the experimental results. The present paper summarizes the outcome of the simulation campaign for the entire Barrel section and for the corresponding prototypes tested at different European installations.

  1. Study on natural convection in core barrel. Experimental and numerical results for band type spacer pads

    International Nuclear Information System (INIS)

    Hayashi, Kenji; Kawamata, Nobuhiro; Kamide, Hideki

    2003-03-01

    In a fast reactor an Inter-Wrapper Flow (IWF) is one of significant phenomena for decay heat removal under natural circulation condition, when a direct reactor auxiliary cooling system (DRACS) is adopted for decay heat removal system. Cold coolant provided by dipped heat exchangers (DHX) of DRACS can penetrate into the core barrel (region between the subassemblies) and it makes natural convection int he core barrel. Such IWF will depend on a spacer pad geometry of subassemblies. Water experiment, TRIF (Test Rig for Inter-wrapper Flow), was carried out for IWF in a reactor core. The test section modeled a 1/12th sector of the core and upper plenum of reactor vessel. Experimental parameters were the spacer pad geometry and flow path geometries connecting the upper plenum and core barrel. Numerical simulation using AQUA code was also performed to confirm applicability of a simulation method. An experimental series using a button type spacer pad had been carried out. Here a band type spacer pad was examined. Temperatures at subassembly wall were measured with parameter of the flow path geometries; one was a connection pipe between the upper plenum and core barrel and the other was flow hole in core former plates between the outermost subassemblies and the core barrel. It was found that these flow paths were effective to remove heat in the core in case of the band type spacer pad. A general purpose three dimensional analysis code, AQUA, was applied to the experimental analysis. Each subassembly and inter wrapper gap region were modeled by slab mesh geometry. Pressure loss coefficient at the pacer pad was set based on the geometry. The numerical simulation results were in good agreement with measured temperature profiles in the core. (author)

  2. Sex differences underlying orofacial varicella zoster associated pain in rats.

    Science.gov (United States)

    Stinson, Crystal; Deng, Mohong; Yee, Michael B; Bellinger, Larry L; Kinchington, Paul R; Kramer, Phillip R

    2017-05-17

    Most people are initially infected with varicella zoster virus (VZV) at a young age and this infection results in chickenpox. VZV then becomes latent and reactivates later in life resulting in herpes zoster (HZ) or "shingles". Often VZV infects neurons of the trigeminal ganglia to cause ocular problems, orofacial disease and occasionally a chronic pain condition termed post-herpetic neuralgia (PHN). To date, no model has been developed to study orofacial pain related to varicella zoster. Importantly, the incidence of zoster associated pain and PHN is known to be higher in women, although reasons for this sex difference remain unclear. Prior to this work, no animal model was available to study these sex-differences. Our goal was to develop an orofacial animal model for zoster associated pain which could be utilized to study the mechanisms contributing to this sex difference. To develop this model VZV was injected into the whisker pad of rats resulting in IE62 protein expression in the trigeminal ganglia; IE62 is an immediate early gene in the VZV replication program. Similar to PHN patients, rats showed retraction of neurites after VZV infection. Treatment of rats with gabapentin, an agent often used to combat PHN, ameliorated the pain response after whisker pad injection. Aversive behavior was significantly greater for up to 7 weeks in VZV injected rats over control inoculated rats. Sex differences were also seen such that ovariectomized and intact female rats given the lower dose of VZV showed a longer affective response than male rats. The phase of the estrous cycle also affected the aversive response suggesting a role for sex steroids in modulating VZV pain. These results suggest that this rat model can be utilized to study the mechanisms of 1) orofacial zoster associated pain and 2) the sex differences underlying zoster associated pain.

  3. Involvement of ERK phosphorylation of trigeminal spinal subnucleus caudalis neurons in thermal hypersensitivity in rats with infraorbital nerve injury.

    Directory of Open Access Journals (Sweden)

    Ikuko Suzuki

    Full Text Available To evaluate the involvement of the mitogen-activated protein kinase (MAPK cascade in orofacial neuropathic pain mechanisms, this study assessed nocifensive behavior evoked by mechanical or thermal stimulation of the whisker pad skin, phosphorylation of extracellular signal-regulated kinase (ERK in trigeminal spinal subnucleus caudalis (Vc neurons, and Vc neuronal responses to mechanical or thermal stimulation of the whisker pad skin in rats with the chronic constriction nerve injury of the infraorbital nerve (ION-CCI. The mechanical and thermal nocifensive behavior was significantly enhanced on the side ipsilateral to the ION-CCI compared to the contralateral whisker pad or sham rats. ION-CCI rats had an increased number of phosphorylated ERK immunoreactive (pERK-IR cells which also manifested NeuN-IR but not GFAP-IR and Iba1-IR, and were significantly more in ION-CCI rats compared with sham rats following noxious but not non-noxious mechanical stimulation. After intrathecal administration of the MEK1 inhibitor PD98059 in ION-CCI rats, the number of pERK-IR cells after noxious stimulation and the enhanced thermal nocifensive behavior but not the mechanical nocifensive behavior were significantly reduced in ION-CCI rats. The enhanced background activities, afterdischarges and responses of wide dynamic range neurons to noxious mechanical and thermal stimulation in ION-CCI rats were significantly depressed following i.t. administration of PD98059, whereas responses to non-noxious mechanical and thermal stimulation were not altered. The present findings suggest that pERK-IR neurons in the Vc play a pivotal role in the development of thermal hypersensitivity in the face following trigeminal nerve injury.

  4. Electrospun composite nanofiber membrane of poly(l-lactide) and surface grafted chitin whiskers: Fabrication, mechanical properties and cytocompatibility.

    Science.gov (United States)

    Liu, Hua; Liu, Wenjun; Luo, Binghong; Wen, Wei; Liu, Mingxian; Wang, Xiaoying; Zhou, Changren

    2016-08-20

    To improve both the mechanical properties and cytocompatibility of poly(l-lactide) (PLLA), rod-like chitin whiskers (CHWs) were prepared, and subsequently surface modified with l-lactide to obtain grafted CHWs (g-CHWs). Then, CHWs and g-CHWs were further introduced into PLLA matrix to fabricate CHWs/PLLA and g-CHWs/PLLA nanofiber membranes by electrospinning technique. Morphologies and properties of the CHWs and g-CHWs were characterized. The surface-grafted PLLA chains played an important role in improving interfacial interaction between the whiskers and PLLA matrix. The g-CHWs dispersed more uniformly in matrix than CHWs, and the as-prepared g-CHWs/PLLA nanofiber membrane showed relative smooth and uniform fiber. As a result, the tensile strength and modulus of the g-CHWs/PLLA nanofiber membrane were obviously superior to those of the pure PLLA and CHWs/PLLA nanofiber membranes. Cells culture results indicated that g-CHWs/PLLA nanofiber membrane is more effectively in promoting MC3T3-E1 cells adhesion, spreading and proliferation than pure PLLA and CHWs/PLLA nanofiber membrane. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Highly conductive Al-doped tetra-needle-like ZnO whiskers prepared by a solid state method

    International Nuclear Information System (INIS)

    Wan Cuifeng; Tan Hairen; Jin Shengming; Yang Huaming; Tang Motang; He Jing

    2008-01-01

    Tetra-needle-like zinc oxide whiskers (T-ZnO W ) were doped with Al 3+ by a solid state method. In this study, modification conditions were thoroughly investigated to obtain low resistivity T-ZnO W , without destroying the tetra-needle-like structure. The Al-doped T-ZnO W was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transition infrared (FT-IR) spectra and electrical resistance measurement. The SEM and XRD results indicated that the tetra-needle-like structure of ZnO whiskers could be well maintained after modification and the doped (0 0 2) face was preferred. FT-IR results showed that the decrease of resistivity of Al-doped T-ZnO W resulted from formation of [AlO 4 ] configuration in T-ZnO W bulk. Experiment results showed that the annealing temperature, doping concentration and type of Al sources affected the resistivity of T-ZnO W considerably. The optimum Al-doped concentration was 7.0 at.% and the resistivity of T-ZnO W could be considerably decreased from 10 8 to 10 2 Ω cm

  6. A Preliminary Evaluation of Lyophilized Gelatin Sponges, Enhanced with Platelet-Rich Plasma, Hydroxyapatite and Chitin Whiskers for Bone Regeneration

    Directory of Open Access Journals (Sweden)

    Andrew J. Spence

    2013-04-01

    Full Text Available The purpose of this study was to perform a number of preliminary in vitro evaluations on an array of modified gelatin gel sponge scaffolds for use in a bone graft application. The gelatin gels were modified through the addition of a number of components which each possess unique properties conducive to the creation and regeneration of bone: a preparation rich in growth factors (PRGF, a bioactive, lyophilized form of platelet-rich plasma, hydroxyapatite, and chitin whiskers. Platelet-rich plasma therapy is an emerging practice that has proven effective in a number of clinical applications, including enhancing bone repair through improved deposition of new bony matrix and angiogenesis. As such, the inclusion of PRGF in our gelatin scaffolds was intended to significantly enhance scaffold bioactivity, while the addition of hydroxyapatite and chitin whiskers were anticipated to increase scaffold strength. Additionally, the gelatin sponges, which readily dissolve in aqueous solutions, were subjected to 1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC cross-linking, either during or post-gelation, to control their rate of degradation. Scaffolds were evaluated in vitro with respect to compressive strength, mass loss/degradation, protein release, and cellular interaction, with results demonstrating the potential of the gelatin gel sponge scaffold for use in the regeneration of bone.

  7. A Preliminary Evaluation of Lyophilized Gelatin Sponges, Enhanced with Platelet-Rich Plasma, Hydroxyapatite and Chitin Whiskers for Bone Regeneration

    Science.gov (United States)

    Rodriguez, Isaac A.; Sell, Scott A.; McCool, Jennifer M.; Saxena, Gunjan; Spence, Andrew J.; Bowlin, Gary L.

    2013-01-01

    The purpose of this study was to perform a number of preliminary in vitro evaluations on an array of modified gelatin gel sponge scaffolds for use in a bone graft application. The gelatin gels were modified through the addition of a number of components which each possess unique properties conducive to the creation and regeneration of bone: a preparation rich in growth factors (PRGF, a bioactive, lyophilized form of platelet-rich plasma), hydroxyapatite, and chitin whiskers. Platelet-rich plasma therapy is an emerging practice that has proven effective in a number of clinical applications, including enhancing bone repair through improved deposition of new bony matrix and angiogenesis. As such, the inclusion of PRGF in our gelatin scaffolds was intended to significantly enhance scaffold bioactivity, while the addition of hydroxyapatite and chitin whiskers were anticipated to increase scaffold strength. Additionally, the gelatin sponges, which readily dissolve in aqueous solutions, were subjected to 1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC) cross-linking, either during or post-gelation, to control their rate of degradation. Scaffolds were evaluated in vitro with respect to compressive strength, mass loss/degradation, protein release, and cellular interaction, with results demonstrating the potential of the gelatin gel sponge scaffold for use in the regeneration of bone. PMID:24709699

  8. [Effect of amount of silane coupling agent on flexural strength of dental composite resins reinforced with aluminium borate whisker].

    Science.gov (United States)

    Zhu, Ming-yi; Zhang, Xiu-yin

    2015-06-01

    To evaluate the effect of amount of silane coupling agent on flexural strength of dental composite resins reinforced with aluminium borate whisker (ABW). ABW was surface-treated with 0%, 1%, 2%, 3% and 4% silan coupling agent (γ-MPS), and mixed with resin matrix to synthesize 5 groups of composite resins. After heat-cured at 120 degrees centigrade for 1 h, specimens were tested in three-point flexure to measure strength according to ISO-4049. One specimen was selected randomly from each group and observed under scanning electron microscope (SEM). The data was analyzed with SAS 9.2 software package. The flexural strength (117.93±11.9 Mpa) of the group treated with 2% silane coupling agent was the highest, and significantly different from that of the other 4 groups (α=0.01). The amount of silane coupling agent has impact on the flexural strength of dental composite resins reinforced with whiskers; The flexual strength will be reduced whenever the amount is higher or lower than the threshold. Supported by Research Fund of Science and Technology Committee of Shanghai Municipality (08DZ2271100).

  9. Using hardware models to quantify sensory data acquisition across the rat vibrissal array.

    Science.gov (United States)

    Gopal, Venkatesh; Hartmann, Mitra J Z

    2007-12-01

    Our laboratory investigates how animals acquire sensory data to understand the neural computations that permit complex sensorimotor behaviors. We use the rat whisker system as a model to study active tactile sensing; our aim is to quantitatively describe the spatiotemporal structure of incoming sensory information to place constraints on subsequent neural encoding and processing. In the first part of this paper we describe the steps in the development of a hardware model (a 'sensobot') of the rat whisker array that can perform object feature extraction. We show how this model provides insights into the neurophysiology and behavior of the real animal. In the second part of this paper, we suggest that sensory data acquisition across the whisker array can be quantified using the complete derivative. We use the example of wall-following behavior to illustrate that computing the appropriate spatial gradients across a sensor array would enable an animal or mobile robot to predict the sensory data that will be acquired at the next time step.

  10. Spontaneous growth of whiskers from an interlayer of Mo sub 2 C beneath a diamond particle deposited in a combustion-flame

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Katsuyuki; Komatsu, Shojiro; Ishigaki, Takamasa; Matsumoto, Seiichiro; Moriyoshi, Yusuke (National Inst. for Research in Inorganic Materials, Tsukuba, Ibaraki (Japan))

    1992-02-01

    When diamond particles deposited on a molybdenum substrate in a C{sub 2}H{sub -}O{sub 2} combustion-flame were kept for one year in the ambient atmosphere at room temperature, spontaneous whisker growth from an interlayer of Mo{sub 2}C beneath the diamond particles took place. The whiskers were clarified by electron probe micro-analysis (EPMA) and transmission electron microscopy (TEM) in a polycrystal composed of MoO{sub 2}, MoOC, and Mo{sub 2}C. The growth mechanism of them is discussed from two different points of view as follows: One is that the oxidation of an interlayer of Mo{sub 2}C beneath a diamond particle effectively reduces the surface free energy between the interlayer and diamond particle; consequently, the whisker can grow by using a screw dislocation. The other is that the internal stress existing between a diamond particle and an Mo{sub 2}C interlayer provides a very reactive zone where the growth of whisker takes place through the oxidation of Mo{sub 2}C. (orig.).

  11. Diffusion bonding of an aluminium alloy (AA 2124) reinforced with SiC whiskers, using AL-Li interlayers (AA 8090)

    International Nuclear Information System (INIS)

    Urena, A.; Gomez de Salazar, J.M.; Escalera, M.D.; Escriche, E.

    1994-01-01

    The use of an AL-Li alloy as interlayer for the diffusion bonding of an aluminium matrix composite reinforced with silicon carbide whiskers has been studied. The influence of the different welding parameters on the joint microstructure and mechanical strength has also been analyzed. Besides, the failure mechanisms of shear tested joints have been investigated using fractographic techniques. (Author) 9 refs

  12. Consumer demand for green stormwater management technology in an urban setting: The case of Chicago rain barrels

    Science.gov (United States)

    Ando, Amy W.; Freitas, Luiz P. C.

    2011-12-01

    Hydrological disruption and water pollution from urbanization can be reduced if households in urban areas adopt decentralized storm water controls. We study a citywide municipal subsidized rain-barrel program in the third biggest city in the United States, Chicago, to explore what factors influence whether households purchase this sort of green storm water management technology in an urban setting. Specifically, we regress census-tract level data on the number of rain barrels adopted in different parts of the city on socioeconomic variables, data on local flood frequency, and features of the housing stock. We find that rain-barrel purchases are not correlated with local levels of flooding, even though city residents were told by program managers that rain barrels could alleviate local flooding. Instead, rain barrels are heavily concentrated in places with high-income attitudinally green populations. We do find more rain barrels were adopted in places close to rain-barrel distribution points and near sites of hydrological information campaigns; thus, policy makers might increase green-technology adoption in areas where they can do the most good by reducing transaction costs and providing education programs to those areas. Finally, our results indicate that owner occupancy is positively correlated with green-technology adoption. Low-rise rental housing may have inefficiently low levels of adoption, such that city managers might want to develop programs to encourage storm water management investments by landlords who do not live in their own properties.

  13. Effect of oak wood barrel capacity and utilization time on phenolic and sensorial profile evolution of an Encruzado white wine.

    Science.gov (United States)

    Nunes, Paulo; Muxagata, Sara; Correia, Ana C; Nunes, Fernando M; Cosme, Fernanda; Jordão, António M

    2017-11-01

    Several studies have reported the influence of diverse winemaking technologies in white wine characteristics. However, the impact of the use of different oak wood barrel capacities and utilization time on the evolution of white wine phenolic content and sensorial characteristics are not usually considered. Thus the aim of this work was to evaluate the effect of oak wood barrel capacity and utilization time on the evolution of phenolic compounds, browning potential index and sensorial profile of an Encruzado white wine. For the 180 aging days considered, the use of new oak wood barrels induced a greater increase in global phenolic composition, including several individual compounds, such as gallic and ellagic acid, independently of the barrel capacity. Tendency for a lesser increase of the browning potential index values was detected for white wines aged in new oak wood barrels. The sensorial profile evolution, showed significant differences only for the aroma descriptors, namely for 'wood aroma' and 'aroma intensity', white wine aged in 225 L new oak wood barrels being the highest scored. The results show that, in general, the use of different capacities and utilization time of oak wood barrels used for white wine aging could play an important role in white wine quality. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  14. Quantitative/Statistical Approach to Bullet-to-Firearm Identification with Consecutively Manufactured Barrels

    Energy Technology Data Exchange (ETDEWEB)

    Peter Striupaitis; R.E. Gaensslen

    2005-01-30

    Efforts to use objective image comparison and bullet scanning technologies to distinguish bullets from consecutively manufactured handgun barrels from two manufacturers gave mixed results. The ability of a technology to reliably distinguish between matching and non-matching bullets, where the non-matching bullets were as close in pattern to the matching ones as is probably possible, would provide evidence that the distinctions could be made ''objectively'', and independently of human eyes. That evidence is identical or very close to what seems to be needed to satisfy Daubert standards. It is fair to say that the FTI IBIS image comparison technology correctly distinguished between all the Springfield barrel bullets, and between most but not all of the HiPoint barrel bullets. In the HiPoint cases that were not distinguished 100% of the time, they would he distinguished correctly at least 83% of the time. These results, although obviously limited to the materials used in the comparisons, provide strong evidence that barrel-to-bullet matching is objectively reliable. The results with SciClops were less compelling. The results do not mean that bullet-to-barrel matching is not objectively reliable--rather, they mean that this version of the particular technology could not quite distinguish between these extremely similar yet different bullets as well as the image comparison technology did. In a number of cases, the numerical results made the correct distinctions, although they were close to one another. It is hard to say from this data that this technology differs in its ability to make distinctions between the manufacturers, because the results are very similar with both. The human examiner results were as expected. We did not expect any misidentifications, and there were not any. It would have been preferable to have a higher return rate, and thus more comparisons in the overall sample. As noted, the ''consecutively manufactured barrel

  15. Cobalamin-Independent Methionine Synthase (MetE): A Face-to-Face Double Barrel that Evolved by Gene Duplication

    Energy Technology Data Exchange (ETDEWEB)

    Pejcha, Robert; Ludwig, Martha L. (Michigan)

    2010-03-08

    Cobalamin-independent methionine synthase (MetE) catalyzes the transfer of a methyl group from methyltetrahydrofolate to L-homocysteine (Hcy) without using an intermediate methyl carrier. Although MetE displays no detectable sequence homology with cobalamin-dependent methionine synthase (MetH), both enzymes require zinc for activation and binding of Hcy. Crystallographic analyses of MetE from T. maritima reveal an unusual dual-barrel structure in which the active site lies between the tops of the two ({beta}{alpha}){sub 8} barrels. The fold of the N-terminal barrel confirms that it has evolved from the C-terminal polypeptide by gene duplication; comparisons of the barrels provide an intriguing example of homologous domain evolution in which binding sites are obliterated. The C-terminal barrel incorporates the zinc ion that binds and activates Hcy. The zinc-binding site in MetE is distinguished from the (Cys){sub 3}Zn site in the related enzymes, MetH and betaine-homocysteine methyltransferase, by its position in the barrel and by the metal ligands, which are histidine, cysteine, glutamate, and cysteine in the resting form of MetE. Hcy associates at the face of the metal opposite glutamate, which moves away from the zinc in the binary E {center_dot} Hcy complex. The folate substrate is not intimately associated with the N-terminal barrel; instead, elements from both barrels contribute binding determinants in a binary complex in which the folate substrate is incorrectly oriented for methyl transfer. Atypical locations of the Hcy and folate sites in the C-terminal barrel presumably permit direct interaction of the substrates in a ternary complex. Structures of the binary substrate complexes imply that rearrangement of folate, perhaps accompanied by domain rearrangement, must occur before formation of a ternary complex that is competent for methyl transfer.

  16. Cobalamin-Independent Methionine Synthase (MetE): A Face-to-Face Double Barrel that Evolved by Gene Duplication

    International Nuclear Information System (INIS)

    Pejcha, Robert; Ludwig, Martha L.

    2005-01-01

    Cobalamin-independent methionine synthase (MetE) catalyzes the transfer of a methyl group from methyltetrahydrofolate to L-homocysteine (Hcy) without using an intermediate methyl carrier. Although MetE displays no detectable sequence homology with cobalamin-dependent methionine synthase (MetH), both enzymes require zinc for activation and binding of Hcy. Crystallographic analyses of MetE from T. maritima reveal an unusual dual-barrel structure in which the active site lies between the tops of the two (βα) 8 barrels. The fold of the N-terminal barrel confirms that it has evolved from the C-terminal polypeptide by gene duplication; comparisons of the barrels provide an intriguing example of homologous domain evolution in which binding sites are obliterated. The C-terminal barrel incorporates the zinc ion that binds and activates Hcy. The zinc-binding site in MetE is distinguished from the (Cys) 3 Zn site in the related enzymes, MetH and betaine-homocysteine methyltransferase, by its position in the barrel and by the metal ligands, which are histidine, cysteine, glutamate, and cysteine in the resting form of MetE. Hcy associates at the face of the metal opposite glutamate, which moves away from the zinc in the binary E · Hcy complex. The folate substrate is not intimately associated with the N-terminal barrel; instead, elements from both barrels contribute binding determinants in a binary complex in which the folate substrate is incorrectly oriented for methyl transfer. Atypical locations of the Hcy and folate sites in the C-terminal barrel presumably permit direct interaction of the substrates in a ternary complex. Structures of the binary substrate complexes imply that rearrangement of folate, perhaps accompanied by domain rearrangement, must occur before formation of a ternary complex that is competent for methyl transfer.

  17. Cobalamin-independent methionine synthase (MetE: a face-to-face double barrel that evolved by gene duplication.

    Directory of Open Access Journals (Sweden)

    Robert Pejchal

    2005-02-01

    Full Text Available Cobalamin-independent methionine synthase (MetE catalyzes the transfer of a methyl group from methyltetrahydrofolate to L-homocysteine (Hcy without using an intermediate methyl carrier. Although MetE displays no detectable sequence homology with cobalamin-dependent methionine synthase (MetH, both enzymes require zinc for activation and binding of Hcy. Crystallographic analyses of MetE from T. maritima reveal an unusual dual-barrel structure in which the active site lies between the tops of the two (betaalpha(8 barrels. The fold of the N-terminal barrel confirms that it has evolved from the C-terminal polypeptide by gene duplication; comparisons of the barrels provide an intriguing example of homologous domain evolution in which binding sites are obliterated. The C-terminal barrel incorporates the zinc ion that binds and activates Hcy. The zinc-binding site in MetE is distinguished from the (Cys(3Zn site in the related enzymes, MetH and betaine-homocysteine methyltransferase, by its position in the barrel and by the metal ligands, which are histidine, cysteine, glutamate, and cysteine in the resting form of MetE. Hcy associates at the face of the metal opposite glutamate, which moves away from the zinc in the binary E.Hcy complex. The folate substrate is not intimately associated with the N-terminal barrel; instead, elements from both barrels contribute binding determinants in a binary complex in which the folate substrate is incorrectly oriented for methyl transfer. Atypical locations of the Hcy and folate sites in the C-terminal barrel presumably permit direct interaction of the substrates in a ternary complex. Structures of the binary substrate complexes imply that rearrangement of folate, perhaps accompanied by domain rearrangement, must occur before formation of a ternary complex that is competent for methyl transfer.

  18. Ion irradiation effects on the matrix phase of SiCf/SiC composites prepared by the whisker growing assisted CVI process

    International Nuclear Information System (INIS)

    Park, Kyeong Hwan; Park, Ji Yeon; Kang, Suk Min; Kim, Weon Ju; Jung, Choong Hwan; Ryu, Woo Seog

    2005-01-01

    SiC f /SiC composites are one of promising candidates for structural material of the next generation energy system such as GFR and fusion reactors. A number of fabrication methods have been studied for obtaining an outstanding SiC f /SiC composite with a high density, high crystallinity and purity. SiC f /SiC composites consisted of whisker-reinforced matrix have a great potential at the viewpoint both of the fabrication process and the mechanical properties. SiC whiskers formed between SiC fibers improve the densification of SiC matrix during CVI process. In addition, the reinforced whiskers would be likely to enhance the mechanical properties of matrix and SiC f /SiC composite. While there has been significant developmental work on manufacturing the SiC f /SiC composite by the whisker growing assisted CVI process, detailed understanding of what effects the complex in the operating conditions combined with realistic materials property data is not adequately understood. Especially, its irradiation effects are even less clear and not well understood. A method of charged-particle irradiation is the most important R and D topics for simulating the core conditions of the advanced nuclear systems. Many studies on radiation effects of SiC and SiC f /SiC composites using a method of ion irradiation have in progress for R and D of the advanced nuclear systems. In this present work, changes of the mechanical property of SiC whisker-reinforced matrix in SiC f /SiC composite were evaluated by means of the depth sensing indentation method before and after chargedparticle irradiation

  19. Analysis of Premature Wear-Out of Aircraft Gun Barrel by Applying a Transmission Electron Microscopy (TEM

    Directory of Open Access Journals (Sweden)

    Łęczycki Krzysztof

    2017-08-01

    Full Text Available Firing from gun armament generates a wide range of physico-chemical phenomena contributing to the degradation of barrel material, e.g. pressure, high temperature, chemically aggressive character of post-detonation gases and friction of a driving band. In this work the technique of thin foils was used in Transmission Electron Microscopy (TEM to study the influence of physicochemical phenomena on the material microstructure of aircraft gun barrel. A mechanism and reason of premature wear-out of the barrel under consideration was also outlined by utilising light microscopy and hardness measurements.

  20. SiPM photosensors and fast timing readout for the Barrel Time-of-Flight detector in bar PANDA

    Science.gov (United States)

    Suzuki, K.

    2018-03-01

    The Barrel Time-of-Flight detector system will be installed in the upcoming bar PANDA experiment at FAIR in Germany. The detector has a barrel shape of phi=0.5 m and 1.8 m long, covering about 5 m2, which corresponds to the laboratory polar angle coverage of 22oPANDA Barrel Time-of-Flight detector are presented. The test shows that the current design fulfils satisfactorily the required timing performance (σt~ 56 ps) and the timing performance depends little on the hit position on the surface.

  1. Estimating induced-activation of SCT barrel-modules in the ATLAS radiation environment.

    CERN Document Server

    Buttar, C M; Dawson, I; Mandic, I; Moraes, A

    2002-01-01

    One of the consequences of operating detector systems in the harsh radiation environments of the ATLAS inner-detector will be radioactivation of the components. If the levels of radioactivity and corresponding dose rates are significant, then there will be implications for any access or maintenance operations. Given in this note are predictions for the radioactivation of SCT barrel-modules in the expected radiation environment of the inner-detector, based on both calculations and measurements. It is shown that both neutron-capture and high-energy hadron reactions must be taken into account. The predictions show that, from a radiological point of view, the SCT barrel-modules should not pose any serious problems.

  2. Current Status of the Pixel Phase I Upgrade in CMS: Barrel Module Production

    CERN Document Server

    Bartek, Rachel

    2016-01-01

    The silicon pixel detector is the innermost component of the CMS tracking system, providing high precision space point measurements of charged particle trajectories. Before 2018 the instantaneous luminosity of the LHC is expected to reach about 2~x~$10^{34}~\\rm{cm}^{-2}\\rm{s}^{-1}$, which will significantly increase the number of interactions per bunch crossing. To maintain a high tracking efficiency, CMS has planned to replace the current pixel system during phase I by a new lightweight detector, equipped with an additional 4th layer in the barrel, and one additional forward/backward disk. The present status of barrel modules production will be presented, including preliminary results from tests on the first production pixel modules of the new pixel tracker.

  3. Double-barrelled wet colostomy formation after pelvic exenteration for locally advanced or recurrent rectal cancer.

    Science.gov (United States)

    Bloemendaal, A L A; Kraus, R; Buchs, N C; Hamdy, F C; Hompes, R; Cogswell, L; Guy, R J

    2016-11-01

    In advanced pelvic cancer it may be necessary to perform a total pelvic exenteration. In such cases urinary tract reconstruction is usually achieved with the creation of an ileal conduit with a urinary stoma on the right side of the patient's abdomen and an end colostomy separately on the left. The potential morbidity from a second stoma may be avoided by the use of a double-barrelled wet colostomy (DBWC), as a single stoma. Another advantage is the possibility of using a vertical rectus abdominis muscle flap for perineal reconstruction. All patients undergoing formation of a DBWC were included. A DBWC was formed in 10 patients. One patient underwent formation of a double-barrelled wet ileostomy. In this technical note we present our early experience in 11 cases and a video of DBWC formation in a male patient. Colorectal Disease © 2016 The Association of Coloproctology of Great Britain and Ireland.

  4. Design, Construction and Installation of the ATLAS Hadronic Barrel Scintillator-Tile Calorimeter

    CERN Document Server

    Abdallah, J; Alexa, C; Alves, R; Amaral, P; Ananiev, A; Anderson, K; Andresen, X; Antonaki, A; Batusov, V; Bednar, P; Bergeaas, E; Biscarat, C; Blanch, O; Blanchot, G; Bohm, C; Boldea, V; Bosi, F; Bosman, M; Bromberg, C; Budagov, Yu A; Calvet, D; Cardeira, C; Carli, T; Carvalho, J; Cascella, M; Castillo, M V; Costello, J; Cavalli-Sforza, M; Cavasinni, V; Cerqueira, A S; Clément, C; Cobal, M; Cogswell, F; Constantinescu, S; Costanzo, D; Da Silva, P; Davidek, M; David, T; Dawson, J; De, K; Del Prete, T; Di Girolamo, B; Dita, S; Dolejsi, J; Dolezal, Z; Dotti, A; Downing, R; Drake, G; Efthymiopoulos, I; Errede, D; Errede, S; Farbin, A; Fassouliotis, D; Feng, E; Fenyuk, A; Ferdi, C; Ferreira, B C; Ferrer, A; Flaminio, V; Flix, J; Francavilla, P; Fullana, E; Garde, V; Gellerstedt, K; Giakoumopoulou, V; Giangiobbe, V; Gildemeister, O; Gilewsky, V; Giokaris, N; Gollub, N; Gomes, A; González, V; Gouveia, J; Grenier, P; Gris, P; Guarino, V; Guicheney, C; Sen-Gupta, A; Hakobyan, H; Haney, M; Hellman, S; Henriques, A; Higón, E; Hill, N; Holmgren, S; Hruska, I; Hurwitz, M; Huston, J; Jen-La Plante, I; Jon-And, K; Junk, T; Karyukhin, A; Khubua, J; Klereborn, J; Kopikov, S; Korolkov, I; Krivkova, P; Kulchitsky, Y; Kurochkin, Yu; Kuzhir, P; Lapin, V; Le Compte, T; Lefèvre, R; Leitner, R; Li, J; Liablin, M; Lokajícek, M; Lomakin, Y; Lourtie, P; Lovas, L; Lupi, A; Maidantchik, C; Maio, A; Maliukov, S; Manousakis, A; Marques, C; Marroquim, F; Martin, F; Mazzoni, E; Merritt, F S; Myagkov, A; Miller, R; Minashvili, I; Miralles, L; Montarou, G; Némécek, S; Nessi, M; Nikitine, I; Nodulman, L; Norniella, O; Onofre, A; Oreglia, M; Palan, B; Pallin, D; Pantea, D; Pereira, A; Pilcher, J E; Pina, J; Pinhão, J; Pod, E; Podlyski, F; Portell, X; Poveda, J; Pribyl, L; Price, L E; Proudfoot, J; Ramalho, M; Ramstedt, M; Raposeiro, L; Reis, J; Richards, R; Roda, C; Romanov, V; Rosnet, P; Roy, P; Ruiz, A; Rumiantsau, V; Russakovich, N; Sada Costa, J; Salto, O; Salvachúa, B; Sanchis, E; Sanders, H; Santoni, C; Santos, J; Saraiva, J G; Sarri, F; Says, L P; Schlager, G; Schlereth, J L; Seixas, J M; Selldén, B; Shalanda, N; Shevtsov, P; Shochet, M; Simaitis, V; Simonyan, M; Sisakian, A; Sjölin, J; Solans, C; Solodkov, A; Solovianov, J; Silva, O; Sosebee, M; Spanó, F; Speckmeyer, P; Stanek, R; Starchenko, E; Starovoitov, P; Suk, M; Sykora, I; Tang, F; Tas, P; Teuscher, R; Tokar, S; Topilin, N; Torres, J; Underwood, D; Usai, G; Valero, A; Valkár, S; Valls, J A; Vartapetian, A; Vazeille, F; Vellidis, C; Ventura, F; Vichou, I; Vivarelli, I; Volpi, M; White, A; Zaitsev, A; Zenin, A; Zenis, T; Zenonos, Z; Zenz, S; Zilka, B

    2007-01-01

    The scintillator tile hadronic calorimeter is a sampling calorimeter using steel as the absorber structure and scintillator as the active medium. The scintillator is located in "pockets" in the steel structure and the wavelength-shifting fibers are contained in channels running radially within the absorber to photomultiplier tubes which are located in the outer support girders of the calorimeter structure. In addition, to its role as a detector for high energy particles, the tile calorimeter provides the direct support of the liquid argon electromagnetic calorimeter in the barrel region, and the liquid argon electromagnetic and hadronic calorimeters in the endcap region. Through these, it indirectly supports the inner tracking system and beam pipe. The steel absorber, and in particular the support girders, provide the flux return for the solenoidal field from the central solenoid. Finally, the end surfaces of the barrel calorimeter are used to mount services, power supplies and readout crates for the inner tr...

  5. A Barrel IFR Instrumented With Limited Streamer Tubes for BABAR Experiment

    International Nuclear Information System (INIS)

    Andreotti, M.; Ferrara U.; INFN, Ferrara

    2006-01-01

    The new barrel Instrumented Flux Return (IFR) of BABAR detector will be reported here. Limited Streamer Tubes (LSTs) have been chosen to replace the existing RPCs as active elements of the barrel IFR. The layout of the new detector will be discussed: in particular, a cell bigger than the standard one has been used to improve efficiency and reliability. The extruded profile is coated with a resistive layer of graphite having a typical surface resistivity between 0.2 and 0.4 MOhm/square. The tubes are assembled in modules and installed in 12 active layers of each sextant of the IFR detector. R and D studies to choose the final design and Quality Control procedure adopted during the tube production will be briefly discussed. Finally the performances of installed LSTs into 2/3 of IFR after 8 months of operations will be reported

  6. Intercalibration of the barrel electromagnetic calorimeter of the CMS experiment at start-up

    CERN Document Server

    Adzic, Petar; Almeida, Nuno; Anagnostou, Georgios; Andelin, Daniel; Anfreville, Marc; Anicin, Ivan; Antunovic, Zeljko; Arcidiacono, Roberta; Arenton, Michael Wayne; Auffray, Etiennette; Argiro, Stefano; Askew, Andrew; Atramentov, Oleksiy; Baccaro, Stefania; Baffioni, Stephanie; Balazs, Michael; Barney, David; Barone, Luciano; Bartoloni, Alessandro; Baty, Clement; Bandurin, Dmitry; Beauceron, Stephanie; Bell, Ken W; Benetta, Robert; Bercher, Michel; Bernet, Colin; Berthon, Ursula; Besançon, Marc; Betev, Botjo; Beuselinck, Raymond; Biino, Cristina; Blaha, Jan; Bloch, Philippe; Blyth, Simon; Bornheim, Adolf; Bourotte, Jean; Brett, Angela Mary; Brown, Robert M; Britton, David; Bühler, M; Busson, Philippe; Camanzi, Barbara; Camporesi, Tiziano; Carrera, E; Cartiglia, Nicolo; Cavallari, Francesca; Cerutti, Muriel; Chang, Paoti; Chang, You-Hao; Charlot, Claude; Chen, E Augustine; Chen, Wan-Ting; Chen, Zheng-Yu; Chipaux, Rémi; Choudhary, Brajesh C; Choudhury, Rajani Kant; Cockerill, David J A; Combaret, Christophe; Conetti, Sergio; Cossutti, Fabio; Cox, Bradley; Cussans, David; Dafinei, Ioan; Da Silva Di Calafiori, Diogo Raphael; Daskalakis, Georgios; Davatz, Giovanna; David, A; Deiters, Konrad; Dejardin, Marc; Djordjevic, Milos; Della Negra, Rodolphe; Della Ricca, Giuseppe; Del Re, Daniele; De Min, Alberto; Denegri, Daniel; Depasse, Pierre; Descamps, Julien; Diemoz, Marcella; Di Marco, Emanuele; Dissertori, Günther; Dittmar, Michael; Djambazov, Lubomir; Dobrzynski, Ludwik; Drndarevic, Snezana; Duboscq, Jean Etienne; Dutta, Dipanwita; Dzelalija, Mile; Peisert, A; El-Mamouni, H; Evangelou, Ioannis; Evans, David; Fabbro, Bernard; Faure, Jean-Louis; Fay, Jean; Ferri, Federico; Flower, Paul S; Franci, Daniele; Franzoni, Giovanni; Freudenreich, Klaus; Funk, Wolfgang; Ganjour, Serguei; Gargiulo, Corrado; Gascon, Susan; Gataullin, Marat; Geerebaert, Yannick; Gentit, François-Xavier; Gershtein, Yuri; Ghezzi, Alessio; Ghodgaonkar, Manohar; Gilly, Jean; Givernaud, Alain; Gninenko, Sergei; Go, Apollo; Gobbo, Benigno; Godinovic, Nikola; Golubev, Nikolai; Gong, Datao; Govoni, Pietro; Grant, Nicholas; Gras, Philippe; Greenhalgh, R J S; Guevara Riveros, Luz; Guillaud, Jean-Paul; Haguenauer, Maurice; Hamel de Monchenault, Gautier; Hansen, Magnus; Heath, Helen F; Heltsley, Brian; Hill, Jack; Hintz, Wieland; Hirosky, Robert; Hobson, Peter R; Honma, Alan; Hou, George Wei-Shu; Hsiung, Yee; Husejko, Michal; Ille, Bernard; Imlay, Richard; Ingram, Quentin; Jarry, Patrick; Jessop, Colin; Jovanovic, Dragoslav; Kaadze, Ketino; Kachanov, Vassili; Kailas, Swaminathan; Kataria, Sushil Kumar; Kennedy, Bruce W; Kloukinas, Kostas; Kokkas, Panagiotis; Kolberg, Ted; Krasnikov, Nikolai; Krpic, Dragomir; Kubota, Yuichi; Kumar, P; Kuo, Chen-Cheng; Kyberd, Paul; Kyriakis, Aristotelis; Lebeau, Michel; Lecomte, Pierre; Lecoq, Paul; Ledovskoy, Alexander; Leshev, Georgi; Lethuillier, Morgan; Lin, Sheng-Wen; Lin, Willis; Lintern, A L; Litvine, Vladimir; Locci, Elizabeth; Lodge, Anthony B; Longo, Egidio; Loukas, Demetrios; Luckey, Paul David; Lustermann, Werner; Lynch, Clare; Ma, Yousi; Mahlke-Krüger, H; Malberti, Martina; Malcles, Julie; Maletic, Dimitrije; Mandjavidze, Irakli; Manthos, Nikolaos; Maravin, Yurii; Marchica, Carmelo; Marinelli, Nancy; Markou, Athanasios; Markou, Christos; Marone, Matteo; Mathez, Hervé; Matveev, Viktor; Mavrommatis, Charalampos; Maurelli, Georges; Meridiani, Paolo; Milenovic, Predrag; Milleret, Gérard; Miné, Philippe; Mohanty, Ajit Kumar; Moortgat, Filip; Mur, Michel; Musella, Pasquale; Musienko, Yuri; Nardulli, Alessandro; Nash, Jordan; Nédélec, Patrick; Negri, Pietro; Newman, Harvey B; Nikitenko, Alexander; Nessi-Tedaldi, Francesca; Obertino, Maria Margherita; Organtini, Giovanni; Orimoto, Toyoko; Paganoni, Marco; Paganini, Pascal; Palma, Alessandro; Panev, Bozhidar; Pant, Lalit Mohan; Papadakis, Antonakis; Papadakis, Ioannis; Papadopoulos, Ioannis; Paramatti, Riccardo; Parracho, P; Pastrone, Nadia; Patterson, Juliet Ritchie; Pauss, Felicitas; Petrakou, Eleni; Phillips, D G; Piroué, Pierre; Ptochos, Fotios; Puljak, Ivica; Pullia, Antonino; Punz, Thomas; Puzovic, Jovan; Ragazzi, Stefano; Rahatlou, Shahram; Rander, John; Razis, Panos A; Redaelli, Nicola; Renker, Dieter; Reucroft, Steve; Reymond, Jean-Marc; Ribeiro, Pedro Quinaz; Röser, Ulf; Rogan, Christopher; Romanteau, Thierry; Rondeaux, Françoise; Ronquest, Michael; Rosowsky, André; Rovelli, Chiara; Rumerio, Paolo; Rusack, Roger; Rusakov, Sergey V; Ryan, Matthew John; Sala, Leonardo; Salerno, Roberto; Santanastasio, Francesco; Schinzel, Dietrich; Seez, Christopher; Sharp, Peter; Shepherd-Themistocleous, Claire; Siamitros, Christos; Sillou, Daniel; Singovsky, Alexander; Sirois, Yves; Sirunyan, Albert M; Silva, J; Silva, Pedro; Shiu, Jing-Ge; Shivpuri, Ram Krishen; Shukla, Prashant; Smith, Brian; Smith, Vincent J; Sproston, Martin; Stöckli, Fabian; Suter, Henry; Swain, John; Tabarellide Fatis, T; Takahashi, Maiko; Tcheremoukhine, Alexandre; Teller, Olivier; Theofilatos, Konstantinos; Thiebaux, Christophe; Timciuc, Vladlen; Timlin, Claire; Titov, Maksym; Tobias, A; Topkar, Anita; Triantis, Frixos A; Troshin, Sergey; Tyurin, Nikolay; Ueno, Koji; Uzunian, Andrey; Varela, Joao; Verrecchia, Patrice; Veverka, Jan; Vichoudis, Paschalis; Virdee, Tejinder; Vlassov, E; Von Gunten, Hans Peter; Wang, Minzu; Wardrope, David; Weber, Markus; Weng, Joanna; Williams, Jennifer C; Yang, Yong; Yaselli, Ignacio; Yohay, Rachel; Zabi, Alexandre; Zamiatin, Nikolai; Zelepoukine, Serguei; Zhang, Jia-Wen; Zhang, Lin; Zhu, Kejun; Zhu, Ren-Yuan

    2008-01-01

    Calibration of the relative response of the individual channels of the barrel electromagnetic calorimeter of the CMS detector was accomplished before installation with cosmic ray muons and test beams. One fourth of the calorimeter was exposed to a beam of high energy electrons and the relative calibration of the channels, the intercalibration, was found to be reproducible to a precision of about 0.3\\%. Additionally, data were collected with cosmic rays for the entire ECAL barrel during the commissioning phase. By comparing the intercalibration constants obtained with the electron beam data with those from the cosmic ray data, it is demonstrated that the latter provide an intercalibration precision of 1.5\\% over most of the ECAL. The best intercalibration precision is expected to come from the analysis of events collected {\\it in situ} during the LHC operation. Using data collected with both electrons and pion beams, several aspects of the intercalibration procedures based on electrons or neutral pions were in...

  7. TEM study of radiation induced defects in baffle-former-barrel assembly from decommissioned NPP Greifswald

    International Nuclear Information System (INIS)

    Srba, O.; Michalicka, J.; Keilova, E.; Kocik, K.

    2013-06-01

    A complex transmission electron microscopy (TEM) study of reactor vessel internal (RVI) materials from the baffle-former-barrel assembly from NPP Greifswald (VVER 440), Unit 1 decommissioned after 15 service cycles has been undertaken. All parts of the baffle-former-barrel assembly are made from Ti-stabilized austenitic stainless steel 08Ch18N10T. The materials were exposed to different dose of neutron radiation (2.4 - 11.4 dpa) at temperatures 267 - 398 deg. C depending on position in the core. Three types of radiation induced defects were identified and quantified, namely: dislocations, cavities (voids) and fine-scaled precipitated particles of Ni-Si rich phases. Black-dot type defects were observed too. Operation conditions are around ≅ 300 deg. C that is why we have observed defect typical for both low and high regions of irradiation temperatures. (authors)

  8. The CMS Barrel Calorimeter Response to Particle Beams from 2 to 350 GeV/c

    CERN Document Server

    Yazgan, Elfe

    2009-01-01

    The response of the combined CMS barrel calorimeters to hadrons, electrons and muons over a range from 2 to 350 GeV/$c$ has been measured. The analysis of the differences in calorimeter response to charged pions, kaons, protons and antiprotons and a discussion of the underlying phenomena are presented. Techniques to correct the signals from the considerably different electromagnetic (EB) and hadronic (HB) barrel calorimeters in reconstructing the energies of hadrons are also presented. Above 5 GeV/$c$, these corrections improve the energy resolution of the combined system where the stochastic term equals $84.7$\\% and the constant term is $7.4$\\%. The corrected mean response remains constant within 1.3\\% {\\it rms}.

  9. Study of a twisted ATLAS SCT Barrel deformation as revealed by a photogrammetric survey

    CERN Document Server

    Dobson, E; Heinemann, F; Karagoz-Unel, M

    2007-01-01

    A photogrammetry survey on the SCT barrels was performed as an engineering check on the structure of the ATLAS Semiconductor Tracker (SCT) shortly after construction. Analysis of the data obtained revealed small scale elliptical deformation as well as a twist of the structure. The results of the survey are presented as well as interpolation of the measured targets to the module positions and a comparison with track based alignment measurements.

  10. Diagnosis of vibrations of barrel and fuel elements in the PWRs of Relishing Sweden

    International Nuclear Information System (INIS)

    Pazsit, I.; Martin, M.

    2011-01-01

    The diagnosis of the inside of the PWR, in particular the core barrel and its support can be performed by analysis of the signals from the neutron detectors extra-nuclear. Several methods have been developed that have been used in various plants worldwide. The objective is to monitor the integrity of the core structure and the early detection and quantification of signs of fatigue, wear, etc. in the different structures.

  11. Performance Study of the CMS Barrel Resistive Plate Chambers with Cosmic Rays

    CERN Document Server

    Chatrchyan, S; Sirunyan, A M; Adam, W; Arnold, B; Bergauer, H; Bergauer, T; Dragicevic, M; Eichberger, M; Erö, J; Friedl, M; Frühwirth, R; Ghete, V M; Hammer, J; Hänsel, S; Hoch, M; Hörmann, N; Hrubec, J; Jeitler, M; Kasieczka, G; Kastner, K; Krammer, M; Liko, D; Magrans de Abril, I; Mikulec, I; Mittermayr, F; Neuherz, B; Oberegger, M; Padrta, M; Pernicka, M; Rohringer, H; Schmid, S; Schöfbeck, R; Schreiner, T; Stark, R; Steininger, H; Strauss, J; Taurok, A; Teischinger, F; Themel, T; Uhl, D; Wagner, P; Waltenberger, W; Walzel, G; Widl, E; Wulz, C E; Chekhovsky, V; Dvornikov, O; Emeliantchik, I; Litomin, A; Makarenko, V; Marfin, I; Mossolov, V; Shumeiko, N; Solin, A; Stefanovitch, R; Suarez Gonzalez, J; Tikhonov, A; Fedorov, A; Karneyeu, A; Korzhik, M; Panov, V; Zuyeuski, R; Kuchinsky, P; Beaumont, W; Benucci, L; Cardaci, M; De Wolf, E A; Delmeire, E; Druzhkin, D; Hashemi, M; Janssen, X; Maes, T; Mucibello, L; Ochesanu, S; Rougny, R; Selvaggi, M; Van Haevermaet, H; Van Mechelen, P; Van Remortel, N; Adler, V; Beauceron, S; Blyweert, S; D'Hondt, J; De Weirdt, S; Devroede, O; Heyninck, J; Kalogeropoulos, A; Maes, J; Maes, M; Mozer, M U; Tavernier, S; Van Doninck, W; Van Mulders, P; Villella, I; Bouhali, O; Chabert, E C; Charaf, O; Clerbaux, B; De Lentdecker, G; Dero, V; Elgammal, S; Gay, A P R; Hammad, G H; Marage, P E; Rugovac, S; Vander Velde, C; Vanlaer, P; Wickens, J; Grunewald, M; Klein, B; Marinov, A; Ryckbosch, D; Thyssen, F; Tytgat, M; Vanelderen, L; Verwilligen, P; Basegmez, S; Bruno, G; Caudron, J; Delaere, C; Demin, P; Favart, D; Giammanco, A; Grégoire, G; Lemaitre, V; Militaru, O; Ovyn, S; Piotrzkowski, K; Quertenmont, L; Schul, N; Beliy, N; Daubie, E; Alves, G A; Pol, M E; Souza, M H G; Carvalho, W; De Jesus Damiao, D; De Oliveira Martins, C; Fonseca De Souza, S; Mundim, L; Oguri, V; Santoro, A; Silva Do Amaral, S M; Sznajder, A; Fernandez Perez Tomei, T R; Ferreira Dias, M A; Gregores, E M; Novaes, S F; Abadjiev, K; Anguelov, T; Damgov, J; Darmenov, N; Dimitrov, L; Genchev, V; Iaydjiev, P; Piperov, S; Stoykova, S; Sultanov, G; Trayanov, R; Vankov, I; Dimitrov, A; Dyulendarova, M; Kozhuharov, V; Litov, L; Marinova, E; Mateev, M; Pavlov, B; Petkov, P; Toteva, Z; Chen, G M; Chen, H S; Guan, W; Jiang, C H; Liang, D; Liu, B; Meng, X; Tao, J; Wang, J; Wang, Z; Xue, Z; Zhang, Z; Ban, Y; Cai, J; Ge, Y; Guo, S; Hu, Z; Mao, Y; Qian, S J; Teng, H; Zhu, B; Avila, C; Baquero Ruiz, M; Carrillo Montoya, C A; Gomez, A; Gomez Moreno, B; Ocampo Rios, A A; Osorio Oliveros, A F; Reyes Romero, D; Sanabria, J C; Godinovic, N; Lelas, K; Plestina, R; Polic, D; Puljak, I; Antunovic, Z; Dzelalija, M; Brigljevic, V; Duric, S; Kadija, K; Morovic, S; Fereos, R; Galanti, M; Mousa, J; Papadakis, A; Ptochos, F; Razis, P A; Tsiakkouri, D; Zinonos, Z; Hektor, A; Kadastik, M; Kannike, K; Müntel, M; Raidal, M; Rebane, L; Anttila, E; Czellar, S; Härkönen, J; Heikkinen, A; Karimäki, V; Kinnunen, R; Klem, J; Kortelainen, M J; Lampén, T; Lassila-Perini, K; Lehti, S; Lindén, T; Luukka, P; Mäenpää, T; Nysten, J; Tuominen, E; Tuominiemi, J; Ungaro, D; Wendland, L; Banzuzi, K; Korpela, A; Tuuva, T; Nedelec, P; Sillou, D; Besancon, M; Chipaux, R; Dejardin, M; Denegri, D; Descamps, J; Fabbro, B; Faure, J L; Ferri, F; Ganjour, S; Gentit, F X; Givernaud, A; Gras, P; Hamel de Monchenault, G; Jarry, P; Lemaire, M C; Locci, E; Malcles, J; Marionneau, M; Millischer, L; Rander, J; Rosowsky, A; Rousseau, D; Titov, M; Verrecchia, P; Baffioni, S; Bianchini, L; Bluj, M; Busson, P; Charlot, C; Dobrzynski, L; Granier de Cassagnac, R; Haguenauer, M; Miné, P; Paganini, P; Sirois, Y; Thiebaux, C; Zabi, A; Agram, J L; Besson, A; Bloch, D; Bodin, D; Brom, J M; Conte, E; Drouhin, F; Fontaine, J C; Gelé, D; Goerlach, U; Gross, L; Juillot, P; Le Bihan, A C; Patois, Y; Speck, J; Van Hove, P; Baty, C; Bedjidian, M; Blaha, J; Boudoul, G; Brun, H; Chanon, N; Chierici, R; Contardo, D; Depasse, P; Dupasquier, T; El Mamouni, H; Fassi, F; Fay, J; Gascon, S; Ille, B; Kurca, T; Le Grand, T; Lethuillier, M; Lumb, N; Mirabito, L; Perries, S; Vander Donckt, M; Verdier, P; Djaoshvili, N; Roinishvili, N; Roinishvili, V; Amaglobeli, N; Adolphi, R; Anagnostou, G; Brauer, R; Braunschweig, W; Edelhoff, M; Esser, H; Feld, L; Karpinski, W; Khomich, A; Klein, K; Mohr, N; Ostaptchouk, A; Pandoulas, D; Pierschel, G; Raupach, F; Schael, S; Schultz von Dratzig, A; Schwering, G; Sprenger, D; Thomas, M; Weber, M; Wittmer, B; Wlochal, M; Actis, O; Altenhöfer, G; Bender, W; Biallass, P; Erdmann, M; Fetchenhauer, G; Frangenheim, J; Hebbeker, T; Hilgers, G; Hinzmann, A; Hoepfner, K; Hof, C; Kirsch, M; Klimkovich, T; Kreuzer, P; Lanske, D; Merschmeyer, M; Meyer, A; Philipps, B; Pieta, H; Reithler, H; Schmitz, S A; Sonnenschein, L; Sowa, M; Steggemann, J; Szczesny, H; Teyssier, D; Zeidler, C; Bontenackels, M; Davids, M; Duda, M; Flügge, G; Geenen, H; Giffels, M; Haj Ahmad, W; Hermanns, T; Heydhausen, D; Kalinin, S; Kress, T; Linn, A; Nowack, A; Perchalla, L; Poettgens, M; Pooth, O; Sauerland, P; Stahl, A; Tornier, D; Zoeller, M H; Aldaya Martin, M; Behrens, U; Borras, K; Campbell, A; Castro, E; Dammann, D; Eckerlin, G; Flossdorf, A; Flucke, G; Geiser, A; Hatton, D; Hauk, J; Jung, H; Kasemann, M; Katkov, I; Kleinwort, C; Kluge, H; Knutsson, A; Kuznetsova, E; Lange, W; Lohmann, W; Mankel, R; Marienfeld, M; Meyer, A B; Miglioranzi, S; Mnich, J; Ohlerich, M; Olzem, J; Parenti, A; Rosemann, C; Schmidt, R; Schoerner-Sadenius, T; Volyanskyy, D; Wissing, C; Zeuner, W D; Autermann, C; Bechtel, F; Draeger, J; Eckstein, D; Gebbert, U; Kaschube, K; Kaussen, G; Klanner, R; Mura, B; Naumann-Emme, S; Nowak, F; Pein, U; Sander, C; Schleper, P; Schum, T; Stadie, H; Steinbrück, G; Thomsen, J; Wolf, R; Bauer, J; Blüm, P; Buege, V; Cakir, A; Chwalek, T; De Boer, W; Dierlamm, A; Dirkes, G; Feindt, M; Felzmann, U; Frey, M; Furgeri, A; Gruschke, J; Hackstein, C; Hartmann, F; Heier, S; Heinrich, M; Held, H; Hirschbuehl, D; Hoffmann, K H; Honc, S; Jung, C; Kuhr, T; Liamsuwan, T; Martschei, D; Mueller, S; Müller, Th; Neuland, M B; 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Ignatenko, M; Jarvis, C; Mumford, J; Plager, C; Rakness, G; Schlein, P; Tucker, J; Valuev, V; Wallny, R; Yang, X; Babb, J; Bose, M; Chandra, A; Clare, R; Ellison, J A; Gary, J W; Hanson, G; Jeng, G Y; Kao, S C; Liu, F; Liu, H; Luthra, A; Nguyen, H; Pasztor, G; Satpathy, A; Shen, B C; Stringer, R; Sturdy, J; Sytnik, V; Wilken, R; Wimpenny, S; Branson, J G; Dusinberre, E; Evans, D; Golf, F; Kelley, R; Lebourgeois, M; Letts, J; Lipeles, E; Mangano, B; Muelmenstaedt, J; Norman, M; Padhi, S; Petrucci, A; Pi, H; Pieri, M; Ranieri, R; Sani, M; Sharma, V; Simon, S; Würthwein, F; Yagil, A; Campagnari, C; D'Alfonso, M; Danielson, T; Garberson, J; Incandela, J; Justus, C; Kalavase, P; Koay, S A; Kovalskyi, D; Krutelyov, V; Lamb, J; Lowette, S; Pavlunin, V; Rebassoo, F; Ribnik, J; Richman, J; Rossin, R; Stuart, D; To, W; Vlimant, J R; Witherell, M; Apresyan, A; Bornheim, A; Bunn, J; Chiorboli, M; Gataullin, M; Kcira, D; Litvine, V; Ma, Y; Newman, H B; Rogan, C; Timciuc, V; Veverka, J; Wilkinson, R; Yang, Y; Zhang, L; Zhu, K; Zhu, R Y; Akgun, B; Carroll, R; Ferguson, T; Jang, D W; Jun, S Y; Paulini, M; Russ, J; Terentyev, N; Vogel, H; Vorobiev, I; Cumalat, J P; Dinardo, M E; Drell, B R; Ford, W T; Heyburn, B; Luiggi Lopez, E; Nauenberg, U; Stenson, K; Ulmer, K; Wagner, S R; Zang, S L; Agostino, L; Alexander, J; Blekman, F; Cassel, D; Chatterjee, A; Das, S; Gibbons, L K; Heltsley, B; Hopkins, W; Khukhunaishvili, A; Kreis, B; Kuznetsov, V; Patterson, J R; Puigh, D; Ryd, A; Shi, X; Stroiney, S; Sun, W; Teo, W D; Thom, J; Vaughan, J; Weng, Y; Wittich, P; Beetz, C P; Cirino, G; Sanzeni, C; Winn, D; Abdullin, S; Afaq, M A; Albrow, M; Ananthan, B; Apollinari, G; Atac, M; Badgett, W; Bagby, L; Bakken, J A; Baldin, B; Banerjee, S; Banicz, K; Bauerdick, L A T; Beretvas, A; Berryhill, J; Bhat, P C; Biery, K; Binkley, M; Bloch, I; Borcherding, F; Brett, A M; Burkett, K; Butler, J N; Chetluru, V; Cheung, H W K; Chlebana, F; Churin, I; Cihangir, S; Crawford, M; Dagenhart, W; Demarteau, M; Derylo, G; Dykstra, D; Eartly, D P; Elias, J E; Elvira, V D; Evans, D; Feng, L; Fischler, M; Fisk, I; Foulkes, S; Freeman, J; Gartung, P; Gottschalk, E; Grassi, T; Green, D; Guo, Y; Gutsche, O; Hahn, A; Hanlon, J; Harris, R M; Holzman, B; Howell, J; Hufnagel, D; James, E; Jensen, H; Johnson, M; Jones, C D; Joshi, U; Juska, E; Kaiser, J; Klima, B; Kossiakov, S; Kousouris, K; Kwan, S; Lei, C M; Limon, P; Lopez Perez, J A; Los, S; Lueking, L; Lukhanin, G; Lusin, S; Lykken, J; Maeshima, K; Marraffino, J M; Mason, D; McBride, P; Miao, T; Mishra, K; Moccia, S; Mommsen, R; Mrenna, S; Muhammad, A S; Newman-Holmes, C; Noeding, C; O'Dell, V; Prokofyev, O; Rivera, R; Rivetta, C H; Ronzhin, A; Rossman, P; Ryu, S; Sekhri, V; Sexton-Kennedy, E; Sfiligoi, I; Sharma, S; Shaw, T M; Shpakov, D; Skup, E; Smith, R P; Soha, A; Spalding, W J; Spiegel, L; Suzuki, I; Tan, P; Tanenbaum, W; Tkaczyk, S; Trentadue, R; Uplegger, L; Vaandering, E W; Vidal, R; Whitmore, J; Wicklund, E; Wu, W; Yarba, J; Yumiceva, F; Yun, J C; Acosta, D; Avery, P; Barashko, V; Bourilkov, D; Chen, M; Di Giovanni, G P; Dobur, D; Drozdetskiy, A; Field, R D; Fu, Y; Furic, I K; Gartner, J; Holmes, D; Kim, B; Klimenko, S; Konigsberg, J; Korytov, A; Kotov, K; Kropivnitskaya, A; Kypreos, T; Madorsky, A; Matchev, K; Mitselmakher, G; Pakhotin, Y; Piedra Gomez, J; Prescott, C; Rapsevicius, V; Remington, R; Schmitt, M; Scurlock, B; Wang, D; Yelton, J; Ceron, C; Gaultney, V; Kramer, L; Lebolo, L M; Linn, S; Markowitz, P; Martinez, G; Rodriguez, J L; Adams, T; Askew, A; Baer, H; Bertoldi, M; Chen, J; Dharmaratna, W G D; Gleyzer, S V; Haas, J; Hagopian, S; Hagopian, V; Jenkins, M; Johnson, K F; Prettner, E; Prosper, H; Sekmen, S; Baarmand, M M; Guragain, S; Hohlmann, M; Kalakhety, H; Mermerkaya, H; Ralich, R; Vodopiyanov, I; Abelev, B; Adams, M R; Anghel, I M; Apanasevich, L; Bazterra, V E; Betts, R R; Callner, J; Castro, M A; Cavanaugh, R; Dragoiu, C; Garcia-Solis, E J; Gerber, C E; Hofman, D J; Khalatian, S; Mironov, C; Shabalina, E; Smoron, A; Varelas, N; Akgun, U; Albayrak, E A; Ayan, A S; Bilki, B; Briggs, R; Cankocak, K; Chung, K; Clarida, W; Debbins, P; Duru, F; Ingram, F D; Lae, C K; McCliment, E; Merlo, J P; Mestvirishvili, A; Miller, M J; Moeller, A; Nachtman, J; Newsom, C R; Norbeck, E; Olson, J; Onel, Y; Ozok, F; Parsons, J; Schmidt, I; Sen, S; Wetzel, J; Yetkin, T; Yi, K; Barnett, B A; Blumenfeld, B; Bonato, A; Chien, C Y; Fehling, D; Giurgiu, G; Gritsan, A V; Guo, Z J; Maksimovic, P; Rappoccio, S; Swartz, M; Tran, N V; Zhang, Y; Baringer, P; Bean, A; Grachov, O; Murray, M; Radicci, V; Sanders, S; Wood, J S; Zhukova, V; Bandurin, D; Bolton, T; Kaadze, K; Liu, A; Maravin, Y; Onoprienko, D; Svintradze, I; Wan, Z; Gronberg, J; Hollar, J; Lange, D; Wright, D; Baden, D; Bard, R; Boutemeur, M; Eno, S C; Ferencek, D; Hadley, N J; Kellogg, R G; Kirn, M; Kunori, S; Rossato, K; Rumerio, P; Santanastasio, F; Skuja, A; Temple, J; Tonjes, M B; Tonwar, S C; Toole, T; Twedt, E; Alver, B; Bauer, G; Bendavid, J; Busza, W; Butz, E; Cali, I A; Chan, M; D'Enterria, D; Everaerts, P; Gomez Ceballos, G; Hahn, K A; Harris, P; Jaditz, S; Kim, Y; Klute, M; Lee, Y J; Li, W; Loizides, C; Ma, T; Miller, M; Nahn, S; Paus, C; Roland, C; Roland, G; Rudolph, M; Stephans, G; Sumorok, K; Sung, K; Vaurynovich, S; Wenger, E A; Wyslouch, B; Xie, S; Yilmaz, Y; Yoon, A S; Bailleux, D; Cooper, S I; Cushman, P; Dahmes, B; De Benedetti, A; Dolgopolov, A; Dudero, P R; Egeland, R; Franzoni, G; Haupt, J; Inyakin, A; Klapoetke, K; Kubota, Y; Mans, J; Mirman, N; Petyt, D; Rekovic, V; Rusack, R; Schroeder, M; Singovsky, A; Zhang, J; Cremaldi, L M; Godang, R; Kroeger, R; Perera, L; Rahmat, R; Sanders, D A; Sonnek, P; Summers, D; Bloom, K; Bockelman, B; Bose, S; Butt, J; Claes, D R; Dominguez, A; Eads, M; Keller, J; Kelly, T; Kravchenko, I; Lazo-Flores, J; Lundstedt, C; Malbouisson, H; Malik, S; Snow, G R; Baur, U; Iashvili, I; Kharchilava, A; Kumar, A; Smith, K; Strang, M; Alverson, G; Barberis, E; Boeriu, O; Eulisse, G; Govi, G; McCauley, T; Musienko, Y; Muzaffar, S; Osborne, I; Paul, T; Reucroft, S; Swain, J; Taylor, L; Tuura, L; Anastassov, A; Gobbi, B; Kubik, A; Ofierzynski, R A; Pozdnyakov, A; Schmitt, M; Stoynev, S; Velasco, M; Won, S; Antonelli, L; Berry, D; Hildreth, M; Jessop, C; Karmgard, D J; Kolberg, T; Lannon, K; Lynch, S; Marinelli, N; Morse, D M; Ruchti, R; Slaunwhite, J; Warchol, J; Wayne, M; Bylsma, B; Durkin, L S; Gilmore, J; Gu, J; Killewald, P; Ling, T Y; Williams, G; Adam, N; Berry, E; Elmer, P; Garmash, A; Gerbaudo, D; Halyo, V; Hunt, A; Jones, J; Laird, E; Marlow, D; Medvedeva, T; Mooney, M; Olsen, J; Piroué, P; Stickland, D; Tully, C; Werner, J S; Wildish, T; Xie, Z; Zuranski, A; Acosta, J G; Bonnett Del Alamo, M; Huang, X T; Lopez, A; Mendez, H; Oliveros, S; Ramirez Vargas, J E; Santacruz, N; Zatzerklyany, A; Alagoz, E; Antillon, E; Barnes, V E; Bolla, G; Bortoletto, D; Everett, A; Garfinkel, A F; Gecse, Z; Gutay, L; Ippolito, N; Jones, M; Koybasi, O; Laasanen, A T; Leonardo, N; Liu, C; Maroussov, V; Merkel, P; Miller, D H; Neumeister, N; Sedov, A; Shipsey, I; Yoo, H D; Zheng, Y; Jindal, P; Parashar, N; Cuplov, V; Ecklund, K M; Geurts, F J M; Liu, J H; Maronde, D; Matveev, M; Padley, B P; Redjimi, R; Roberts, J; Sabbatini, L; Tumanov, A; Betchart, B; Bodek, A; Budd, H; Chung, Y S; de Barbaro, P; Demina, R; Flacher, H; Gotra, Y; Harel, A; Korjenevski, S; Miner, D C; Orbaker, D; Petrillo, G; Vishnevskiy, D; Zielinski, M; Bhatti, A; Demortier, L; Goulianos, K; Hatakeyama, K; Lungu, G; Mesropian, C; Yan, M; Atramentov, O; Bartz, E; Gershtein, Y; Halkiadakis, E; Hits, D; Lath, A; Rose, K; Schnetzer, S; Somalwar, S; Stone, R; Thomas, S; Watts, T L; Cerizza, G; Hollingsworth, M; Spanier, S; Yang, Z C; York, A; Asaadi, J; Aurisano, A; Eusebi, R; Golyash, A; Gurrola, A; Kamon, T; Nguyen, C N; Pivarski, J; Safonov, A; Sengupta, S; Toback, D; Weinberger, M; Akchurin, N; Berntzon, L; Gumus, K; Jeong, C; Kim, H; Lee, S W; Popescu, S; Roh, Y; Sill, A; Volobouev, I; Washington, E; Wigmans, R; Yazgan, E; Engh, D; Florez, C; Johns, W; Pathak, S; Sheldon, P; Andelin, D; Arenton, M W; Balazs, M; Boutle, S; Buehler, M; Conetti, S; Cox, B; Hirosky, R; Ledovskoy, A; Neu, C; Phillips II, D; Ronquest, M; Yohay, R; Gollapinni, S; Gunthoti, K; Harr, R; Karchin, P E; Mattson, M; Sakharov, A; Anderson, M; Bachtis, M; Bellinger, J N; Carlsmith, D; Crotty, I; Dasu, S; Dutta, S; Efron, J; Feyzi, F; Flood, K; Gray, L; Grogg, K S; Grothe, M; Hall-Wilton, R; Jaworski, M; Klabbers, P; Klukas, J; Lanaro, A; Lazaridis, C; Leonard, J; Loveless, R; Magrans de Abril, M; Mohapatra, A; Ott, G; Polese, G; Reeder, D; Savin, A; Smith, W H; Sourkov, A; Swanson, J; Weinberg, M; Wenman, D; Wensveen, M; White, A

    2010-01-01

    In October and November 2008, the CMS collaboration conducted a programme of cosmic ray data taking, which has recorded about 270 million events. The Resistive Plate Chamber system, which is part of the CMS muon detection system, was successfully operated in the full barrel. More than 98% of the channels were operational during the exercise with typical detection efficiency of 90%. In this paper, the performance of the detector during these dedicated runs is reported.

  12. Influence of fuel vibration on PWR neutron noise associated with core barrel motion

    International Nuclear Information System (INIS)

    Sweeney, F.J.; March-Leuba, J.

    1984-01-01

    Ex-core neutron detector noise has been utilized to monitor core support barrel (CSB) vibrations. In order to observe long-term changes, noise signals at Sequoyah-1 were monitored continuously during the whole first fuel cycle and part of the second cycle. Results suggest that neutron noise measurements performed infrequently may not provide adequate surveillance of the CSB because it may be difficult to separate noise amplitude changes due solely to CSB motion from changes caused by fuel motion and burnup

  13. Homemade battery-operated multi-barreled muzzle-loading gun.

    Science.gov (United States)

    Ramiah, R; Thirunavukkarasu, G

    2003-11-01

    In a recent shootout by a terrorist group against a law enforcement agency, some unusual firearms were seized. On examination, these firearms were found to be homemade, battery-operated, multi-barreled muzzle-loading guns, analogous to a repeater. Reference to battery-operated firearms is rather scanty in the literature. Hence, the unique design features, electrical circuit, and the operation system of these unusual guns are described.

  14. Distortion of the temporary cavity and its influence on staining in firearm barrels.

    Science.gov (United States)

    Schyma, Christian; Müller, Rolf; Brenčičová, Eva; Brünig, Julia

    2018-06-01

    After contact shots to the head, biological traces can be found inside the barrel of the firearm. Experimental protocols to generate this sort of staining, using 12 cm gelatin cubes containing thin foil bags filled with acrylic paint, human blood, and radiocontrast agent, have been developed. Previous research on shots fired at a distance has shown the underlay sustaining these gelatin cubes has an influence on experimental results. This study was conducted to investigate the role of the sustaining base of the gelatin blocks during contact shots, and its influence on the staining result inside firearm barrels. Eighteen contact shots were performed using 22 LR, 32 ACP (7.65 Browning) and 9 mm Luger semi-automatic pistols. With each pistol, shots were fired onto six gelatin cubes; three placed upon a rigid platform and three upon an elastic underlay. The shots were recorded by a high-speed video camera as they penetrated the gelatin cube. Any staining present inside the firearm barrels after the shots were fired was documented by endoscopy. Cross sections of the gelatin blocks were then compared to the high-speed video. It was found that the nature of the staining inside the barrel was not influenced by the underlay sustaining the target model. In the experiment using a 9 mm Luger, the rigid counterfort provoked a visible distortion of the temporary cavity, but, cross sectional analysis of the gelatin cubes did not reveal a relevant influence of the sustaining underlay on the crack length in the gelatin. This could be explained by a secondary expansion of the temporary cavity left by the projectile as a consequence of subsequent inflow of muzzle gases.

  15. Fluid-structure coupled dynamic response of PWR core barrel during LOCA

    International Nuclear Information System (INIS)

    Lu, M.W.; Zhang, Y.G.; Shi, F.

    1991-01-01

    This paper is engaged in the Fluid-Structure Interaction LOCA analysis of the core barrel of PWR. The analysis is performed by a multipurpose computer code SANES. The FSI inside the pressure vessel is treated by a FEM code including some structural and acoustic elements. The transient in the primary loop is solved by a two-phase flow code. Both codes are coupled one another. Some interesting conclusions are drawn. (author)

  16. Right and left support feet of the Central Barrel Yoke of the CMS Detector

    CERN Multimedia

    Franz Leher, DWE

    2000-01-01

    Fully loaded the Central Barrel will weigh 3000 tonnes. Those feet have tosupport this weight. Therefore they are made of 120 mm thick steel plates.To guarantee a maximum coverage for the muon detctor they will house a muon detector just benaeth the top plate. Weight of 1 foot is 35 tonnes.Its height is 3.5 m and it is 2.5 m large

  17. Reversibility and two state behaviour in the thermal unfolding of oligomeric TIM barrel proteins.

    Science.gov (United States)

    Romero-Romero, Sergio; Costas, Miguel; Rodríguez-Romero, Adela; Alejandro Fernández-Velasco, D

    2015-08-28

    Temperature is one of the main variables that modulate protein function and stability. Thermodynamic studies of oligomeric proteins, the dominant protein natural form, have been often hampered because irreversible aggregation and/or slow reactions are common. There are no reports on the reversible equilibrium thermal unfolding of proteins composed of (β/α)8 barrel subunits, albeit this "TIM barrel" topology is one of the most abundant and versatile in nature. We studied the eponymous TIM barrel, triosephosphate isomerase (TIM), belonging to five species of different bacterial taxa. All of them were found to be catalytically efficient dimers. The three-dimensional structure of four enzymes was solved at high/medium resolution. Irreversibility and kinetic control were observed in the thermal unfolding of two TIMs, while for the other three the thermal unfolding was found to follow a two-state equilibrium reversible process. Shifts in the global stability curves of these three proteins are related to the organismal temperature range of optimal growth and modulated by variations in maximum stability temperature and in the enthalpy change at that temperature. Reversibility appears to correlate with the low isoelectric point, the absence of a residual structure in the unfolded state, small cavity volume in the native state, low conformational stability and a low melting temperature. Furthermore, the strong coupling between dimer dissociation and monomer unfolding may reduce aggregation and favour reversibility. It is therefore very thought-provoking to find that a common topological ensemble, such as the TIM barrel, can unfold/refold in the Anfinsen way, i.e. without the help of the cellular machinery.

  18. Safety analysis of ventilation and inspection operations on barrels in which spent fuel elements are stored

    International Nuclear Information System (INIS)

    Pavlovic, R.; Todorovic, D.; Plecas, I.

    2000-01-01

    Safety analysis of possible accident during performing ventilation and inspection operations on barrels in which spent fuel elements are stored has been proposed. Investigation is confined to a case when primary contamination is localized to the disposal room and controlled release of gaseous effluents to the atmosphere. 85 Kr is the most important radionuclide considered risk estimation due to release of gaseous fission products (author) [sr

  19. Mechanical design and material budget of the CMS barrel pixel detector

    Energy Technology Data Exchange (ETDEWEB)

    Amsler, C; Boesiger, K; Chiochia, V; Maier, R; Meyer, Hp; Robmann, P; Scherr, S; Schmidt, A; Steiner, S [Universitaet Zuerich, Physik-Institut, Winterthurerstr. 190, CH-8057 Zuerich (Switzerland); Erdmann, W; Gabathuler, K; Horisberger, R; Koenig, S; Kotlinski, D; Meier, B; Streuli, S [Paul Scherrer Institut, CH-5232 Villigen (Switzerland); Rizzi, A [ETH Zuerich, Institute for Particle Physics, CH-8093 Zuerich (Switzerland)], E-mail: Alexander.Schmidt@cern.ch

    2009-05-15

    The Compact Muon Solenoid experiment at the Large Hadron Collider at CERN includes a silicon pixel detector as its innermost component. Its main task is the precise reconstruction of charged particles close to the primary interaction vertex. This paper gives an overview of the mechanical requirements and design choices for the barrel pixel detector. The distribution of material in the detector as well as its description in the Monte Carlo simulation are discussed in detail.

  20. Mechanical Design and Material Budget of the CMS Barrel Pixel Detector

    CERN Document Server

    Amsler, C; Chiochia, V; Erdmann, W; Gabathuler, K; Horisberger, R; König, S; Kotlinski, D; Maier, R; Meyer, H; Meier, B; Meyer, Hp; Rizzi, A; Robmann, P; Scherr, S; Schmidt, A; Steiner, S; Erdmann, W; Gabathuler, K; Horisberger, R; König, S; Kotlinski, D; Meier, B; Streuli, S; Rizzi, A

    2009-01-01

    The Compact Muon Solenoid experiment at the Large Hadron Collider at CERN includes a silicon pixel detector as its innermost component. Its main task is the precise reconstruction of charged particles close to the primary interaction vertex. This paper gives an overview of the mechanical requirements and design choices for the barrel pixel detector. The distribution of material in the detector as well as its description in the Monte Carlo simulation are discussed in detail.

  1. Test of the wire ageing induced by radiation for the CMS barrel muon chambers

    CERN Document Server

    Conti, E

    2001-01-01

    We have carried out laboratory tests to measure the ageing of a wire tube due to pollutants outgassed by various materials. The tested materials are those used in the barrel muon drift tubes of the CMS experiment at LHC. An X-ray gun irradiated the test tube to accelerate the ageing process. No ageing effect has been measured for a period equivalent to 10 years of operation at LHC. (15 refs).

  2. Performances of the ATLAS Level-1 Muon barrel trigger during the Run-II data taking

    CERN Document Server

    Sessa, Marco; The ATLAS collaboration

    2017-01-01

    The Level-1 Muon Barrel Trigger is one of the main elements of the event selection of the ATLAS experiment at the Large Hadron Collider. It exploits the Resistive Plate Chambers (RPC) detectors to generate the trigger signal. The RPCs are placed in the barrel region of the ATLAS experiment: they are arranged in three concentric double layers and operate in a strong magnetic toroidal field. RPC detectors cover the pseudo-rapidity range $|\\eta|<1.05$ for a total surface of more than $4000\\ m^2$ and about 3600 gas volumes. The Level-1 Muon Trigger in the barrel region allows to select muon candidates with respect to their transverse momentum and associates them with the correct bunch-crossing number. The trigger system is able to take a decision within a latency of about 2 $\\mu s$. The detailed measurement of the RPC detector efficiencies and of the trigger performance during the ATLAS Run-II data taking is here presented.

  3. Forming H-shaped and barrel-shaped nebulae with interacting jets

    Science.gov (United States)

    Akashi, Muhammad; Bear, Ealeal; Soker, Noam

    2018-04-01

    We conduct three-dimensional hydrodynamical simulations of two opposite jets with large opening angles launched from a binary stellar system into a previously ejected shell and show that the interaction can form barrel-like and H-like shapes in the descendant nebula. Such features are observed in planetary nebulae (PNe) and supernova remnants. Under our assumption, the dense shell is formed by a short instability phase of the giant star as it interacts with a stellar companion, and the jets are then launched by the companion as it accretes mass through an accretion disc from the giant star. We find that the H-shaped and barrel-shaped morphological features that the jets form evolve with time, and that there are complicated flow patterns, such as vortices, instabilities, and caps moving ahead along the symmetry axis. We compare our numerical results with images of 12 PNe, and show that jet-shell interaction that we simulate can account for the barrel-like or H-like morphologies that are observed in these PNe.

  4. Upgrade of the CMS muon trigger system in the barrel region

    CERN Document Server

    Rabady, Dinyar; Carlin, Roberto; Codispoti, Giuseppe; Dallavalle, Marco; Erö, Janos; Flouris, Giannis; Foudas, Costas; Fulcher, Jonathan; Guiducci, Luigi; Loukas, Nikitas; Mallios, Stavros; Manthos, Nikos; Papadopoulos, Ioannis; Paradas, Evangelos; Reis, Thomas; Sakulin, Hannes; Sphicas, Paris; Triossi, Andrea; Venturi, Andrea; Wulz, Claudia-Elisabeth

    2016-01-01

    To maintain the excellent performance of the LHC during its Run-1 also in Run-2, the Level-1 Trigger of the Compact Muon Solenoid experiment underwent a significant upgrade. One part of this upgrade was the re-organisation of the muon trigger path from a subsystem-centric view in which hits in the drift tubes, the cathode strip chambers, and the resistive plate chambers were treated separately in dedicated track-finding systems, to one in which complementary detector systems for a given region (barrel, overlap, and endcap) are merged already at the track-finding level. This also required the development of a new system to sort as well as cancel-out the muon tracks found by each system. An overview will be given of the new track-finder system for the barrel region, the Barrel Muon Track Finder (BMTF) as well as the cancel-out and sorting layer, the upgraded Global Muon Trigger (µGMT). While the BMTF improves on the proven and well-tested algorithms used in the Drift Tube Track Finder during Run-1, the µGMT i...

  5. Upgrade of the CMS muon trigger system in the barrel region

    CERN Document Server

    Battilana, Carlo; Codispoti, Giuseppe; Dallavalle, Gaetano-Marco; Ero, Janos; Flouris, Giannis; Fountas, Konstantinos; Fulcher, Jonathan Richard; Guiducci, Luigi; Loukas, Nikitas; Mallios, Stavros; Manthos, Nikolaos; Papadopoulos, Ioannis; Paradas, Evangelos; Rabady, Dinyar Sebastian; Reis, Thomas; Sakulin, Hannes; Sphicas, Paraskevas; Triossi, Andrea; Venturi, Andrea; Wulz, Claudia

    2016-01-01

    To maintain the excellent performance of the LHC during its Run-1 also in Run-2, the Level-1 Trigger of the Compact Muon Solenoid experiment underwent a significant upgrade. One part of this upgrade was the re-organisation of the muon trigger path from a subsystem-centric view in which hits in the drift tubes, the cathode strip chambers, and the resistive plate chambers were treated separately in dedicated track-finding systems, to one in which complementary detector systems for a given region (barrel, overlap, and endcap) are merged already at the track-finding level. This also required the development of a new system to sort as well as cancel-out the muon tracks found by each system. An overview will be given of the new track-finder system for the barrel region, the Barrel Muon Track Finder (BMTF) as well as the cancel-out and sorting layer, the upgraded Global Muon Trigger ($\\mu$GMT). While the BMTF improves on the proven and well-tested algorithms used in the Drift Tube Track Finder during Run-1, the $\\m...

  6. Upgrade of the CMS muon trigger system in the barrel region

    CERN Document Server

    Rabady, Dinyar; Carlin, Roberto; Codispoti, Giuseppe; Dallavalle, Marco; Erö, Janos; Flouris, Giannis; Foudas, Costas; Fulcher, Jonathan; Guiducci, Luigi; Loukas, Nikitas; Mallios, Stavros; Manthos, Nikos; Papadopoulos, Ioannis; Paradas, Evangelos; Reis, Thomas; Sakulin, Hannes; Sphicas, Paris; Triossi, Andrea; Venturi, Andrea; Wulz, Claudia-Elisabeth

    2017-01-01

    To maintain the excellent performance of the LHC during its Run-1 also in Run-2, the Level-1 Trigger of the Compact Muon Solenoid experiment underwent a significant upgrade. One part of this upgrade was the re-organisation of the muon trigger path from a subsystem-centric view in which hits in the drift tubes, the cathode strip chambers, and the resistive plate chambers were treated separately in dedicated track-finding systems, to one in which complementary detector systems for a given region (barrel, overlap, and endcap) are merged already at the track-finding level. This also required the development of a new system to sort as well as cancel-out the muon tracks found by each system. An overview will be given of the new track-finder system for the barrel region, the Barrel Muon Track Finder (BMTF) as well as the cancel-out and sorting layer, the upgraded Global Muon Trigger (µGMT). While the BMTF improves on the proven and well-tested algorithms used in the Drift Tube Track Finder during Run-1, the µGMT i...

  7. Design studies for the Phase II upgrade of the CMS Barrel Electromagnetic Calorimeter

    CERN Document Server

    Orimoto, Toyoko Jennifer

    2016-01-01

    The High Luminosity LHC (HL-LHC) will provide unprecedented instantaneous and integrated luminosity. The lead tungstate crystals forming the barrel part of the Electromagnetic Calorimeter (ECAL) of the Compact Muon Solenoid (CMS) will still perform well, even after the expected integrated luminosity of 3000fb-1 at the end of HL-LHC. The avalanche photodiodes (APDs) used to detect the scintillation light will also continue to be operational, although there will be some increase in noise due to radiation-induced dark currents. This will be mitigated by reducing the barrel operating temperature during HL-LHC running.The front-end electronics of the ECAL barrel will be replaced, in order to remove existing constraints on trigger rate and latency and to provide additional capability to fully exploit the higher luminosity delivered by the HL-LHC. New developments in high-speed optical links will allow single-crystal readout at 40 MHz to upgraded off-detector processors, allowing maximum flexibility and enhanced tri...

  8. Upgrade of the CMS muon trigger system in the barrel region

    CERN Document Server

    AUTHOR|(CDS)2080489; Flouris, Gianis; Fulcher, Jonathan; Loukas, Nikitas; Paradas, Evangelos; Reis,Thomas; Sakulin, Hannes; Wulz, Claudia-Elisabeth

    2016-01-01

    To maintain the excellent performance shown during the LHCs Run-1 the Level-1 Trigger of the Compact Muon Solenoid experiment underwent a significant upgrade. One part of this upgrade is the re-organization of the muon trigger path from a subsystem-centric view in which hits in the drift tubes (DT), the cathode strip chambers (CSC), and the resistive plate chambers (RPC) were treated separately in dedicated track-finding systems to one in which complementary detector systems for a given region (barrel, overlap, and endcap) are merged at the track-finding level. This fundamental restructuring of the muon trigger system required the development of a system to receive track candidates from the track-finding layer, remove potential duplicate tracks, and forward the best candidates to the global decision layer.An overview will be given of the new track-finder system for the barrel region, the Barrel Muon Track Finder (BMTF) as well as the cancel-out and sorting layer, the upgraded Global Muon Trigger ($\\mu$GMT). B...

  9. Identification of Clearance and Contact Stiffness in a Simplified Barrel-Cradle Structure of Artillery System

    Directory of Open Access Journals (Sweden)

    Bing Li

    2015-02-01

    Full Text Available In gun barrel-cradle structure, the presence of clearance usually changes the dynamic response of muzzle and results in shooting dispersion (under continuous firing condition. The parameter estimation of such clearance nonlinear system is the prerequisite for establishing quantitative relation between the clearance and muzzle disturbance. In this paper, the restoring force surface (RFS method and the nonlinear identification through feedback of outputs (NIFO method are first combined for parameter identification in a simplified barrel-cradle structure. With the RFS method, clearance value can be obtained by analyzing the restoring force plot. Then the contact stiffness can be identified by using NIFO method. This identification process is verified in a single-degree-of-freedom (SDOF system with clearance. To adapt to the rigid-flexible coupled beam system with clearances which is simplified from the barrel-cradle structure, a modification for the combined method mentioned above is proposed. The core idea of the modification is reducing the continuous system to multiple-degree-of-freedom (MDOF system to reserve the nonlinear characteristics through modal transformation matrix. The advantage of this transformation is that the linear parts of the MDOF systems are decoupled, which greatly reduces the difficulty of identification. The simulation results have shown the effectiveness of current method.

  10. Resource Review Board Celebrates the Magnet and Liquid Argon Barrel Tests in Hall 180

    CERN Multimedia

    Jenni, P.

    2004-01-01

    Address by the Director-General, R. Aymar, in front of the barrel cryostat. On 25th October 2004 many RRB delegates and guests, ATLAS National Contact Physicists, and colleagues from far and from CERN working on the Liquid Argon calorimeter and the magnet system were gathering in Hall 180 to celebrate the major milestones reached during the past months in this hall: the successful cold tests of the first barrel toroid coil, of the solenoid, and of the barrel Liquid Argon calorimeter. About 250 people spent a relaxing evening after the speeches by the Director-General R. Aymar and by the spokesperson who gave the following address: 'It is a great pleasure for me to welcome you all here in Hall 180 in the name of the ATLAS Collaboration! With a few words I would like to recall why we are actually here today to share, what I hope, is a relaxed and joyful moment. To concentrate it all in one sentence I could say: To thank cordially all the main actors for the enormous work accomplished here over many years,...

  11. Dead zone analysis of ECAL barrel modules under static and dynamic load

    Science.gov (United States)

    Pierre-Emile, T.; Anduze, M.

    2018-03-01

    In the context of ILD project, impact studies of environmental loads on the Electromagnetic CALorimeter (ECAL) have been initiated. The ECAL part considered is the barrel and it consists of several independent modules which are mounted on the Hadronic CALorimeter barrel (HCAL) itself mounted on the cryostat coil and the yoke. The estimate of the gap required between each ECAL modules is fundamental to define the assembly step and avoid mechanical contacts over the barrel lifetime. In the meantime, it has to be done in consideration to the dead spaces reduction and detector hermiticity optimization. Several Finite Element Analysis (FEA) with static and dynamic loads have been performed in order to define correctly the minimum values for those gaps. Due to the implantation site of the whole project in Japan, seismic analysis were carried out in addition to the static ones. This article shows results of these analysis done with the Finite Element Method (FEM) in ANSYS. First results show the impact of HCAL design on the ECAL modules motion in static load. The second study dedicated to seismic approach on a larger model (including yoke and cryostat) gives additional results on earthquake consequences.

  12. Functions of phenylalanine residues within the beta-barrel stem of the anthrax toxin pore.

    Directory of Open Access Journals (Sweden)

    Jie Wang

    2009-07-01

    Full Text Available A key step of anthrax toxin action involves the formation of a protein-translocating pore within the endosomal membrane by the Protective Antigen (PA moiety. Formation of this transmembrane pore by PA involves interaction of the seven 2beta2-2beta3 loops of the heptameric precursor to generate a 14-strand transmembrane beta barrel.We examined the effects on pore formation, protein translocation, and cytotoxicity, of mutating two phenylalanines, F313 and F314, that lie at the tip the beta barrel, and a third one, F324, that lies part way up the barrel.Our results show that the function of these phenylalanine residues is to mediate membrane insertion and formation of stable transmembrane channels. Unlike F427, a key luminal residue in the cap of the pore, F313, F314, and F324 do not directly affect protein translocation through the pore. Our findings add to our knowledge of structure-function relationships of a key virulence factor of the anthrax bacillus.

  13. A review on the gun barrel vibrations and control for a main battle tank

    Directory of Open Access Journals (Sweden)

    Tolga Dursun

    2017-10-01

    Full Text Available Achieving high hitting accuracy for a main battle tank is challenging while the tank is on the move. This can be reached by proper design of a weapon control and gun system. In order to design an effective gun system while the tank is moving, better understanding of the dynamic behavior of the gun system is required. In this study, the dynamic behaviour of a gun system is discussed in this respect. Both experimental and numerical applications for the determination of the dynamic behaviour of a tank gun system are investigated. Methods such as the use of muzzle reference system (MRS and vibration absorbers, and active vibration control technology for the control and the reduction of the muzzle tip deflections are also reviewed. For the existing gun systems without making substantial modifications, MRS could be useful in controlling the deflections of gun barrels with estimation/prediction algorithms. The vibration levels could be cut into half by the use of optimised vibration absorbers for an existing gun. A new gun system with a longer barrel can be as accurate as the one with a short barrel with the appropriate structural modifications.

  14. Water-Soluble Pd8L4 Self-assembled Molecular Barrel as an Aqueous Carrier for Hydrophobic Curcumin.

    Science.gov (United States)

    Bhat, Imtiyaz Ahmad; Jain, Ruchi; Siddiqui, Mujahuddin M; Saini, Deepak K; Mukherjee, Partha Sarathi

    2017-05-01

    A tetrafacial water-soluble molecular barrel (1) was synthesized by coordination driven self-assembly of a symmetrical tetrapyridyl donor (L) with a cis-blocked 90° acceptor [cis-(en)Pd(NO 3 ) 2 ] (en = ethane-1,2-diamine). The open barrel structure of (1) was confirmed by single crystal X-ray diffraction. The presence of a hydrophobic cavity with large windows makes it an ideal candidate for encapsulation and carrying hydrophobic drug like curcumin in an aqueous medium. The barrel (1) encapsulates curcumin inside its molecular cavity and protects highly photosensitive curcumin from photodegradation. The photostability of encapsulated curcumin is due to the absorption of a high proportion of the incident photons by the aromatic walls of 1 with a high absorption cross-sectional area, which helps the walls to shield the guest even against sunlight/UV radiations. As compared to free curcumin in water, we noticed a significant increase in solubility as well as cellular uptake of curcumin upon encapsulation inside the water-soluble molecular barrel (1) in aqueous medium. Fluorescence imaging confirmed that curcumin was delivered into HeLa cancer cells by the aqueous barrel (1) with the retention of its potential anticancer activity. While free curcumin is inactive toward cancer cells in aqueous medium at room temperature due to negligible solubility, the determined IC 50 value of ∼14 μM for curcumin in aqueous medium in the presence of the barrel (1) reflects the efficiency of the barrel as a potential curcumin carrier in aqueous medium without any other additives. Thus, two major challenges of increasing the bioavailability and stability of curcumin in aqueous medium even in the presence of UV light have been addressed by using a new supramolecular water-soluble barrel (1) as a drug carrier.

  15. Parameters, test criteria and fault assessment in random sampling of waste barrels from non-qualified processes

    International Nuclear Information System (INIS)

    Martens, B.R.

    1989-01-01

    In the context of random sampling tests, parameters are checked on the waste barrels and criteria are given on which these tests are based. Also, it is shown how faulty data on the properties of the waste or faulty waste barrels should be treated. To decide the extent of testing, the properties of the waste relevant to final storage are determined based on the conditioning process used. (DG) [de

  16. An outbreak of norovirus-associated acute gastroenteritis associated with contaminated barrelled water in many schools in Zhejiang, China

    Science.gov (United States)

    Sheng, Minyang; Song, Jianqiang; He, Fan; Qiu, Yinwei; Wu, Haocheng; Lu, Qinbao; Feng, Yan; Lin, Junfen; Chen, Enfu; Chai, Chengliang

    2017-01-01

    Objectives More than 900 students and teachers at many schools in Jiaxing city developed acute gastroenteritis in February 2014. An immediate epidemiological investigation was conducted to identify the pathogen, infection sources and route of transmission. Methods The probable cases and confirmed cases were defined as students or teachers with diarrhoea or vomiting present since the term began in February 2014. An active search was conducted for undiagnosed cases among students and teachers. Details such as demographic characteristics, gastrointestinal symptoms, and drinking water preference and frequency were collected via a uniform epidemiological questionnaire. A case-control study was implemented, and odds ratios (ORs) and 95% confidence intervals were calculated. Rectal swabs from several patients, food handlers and barrelled water factory workers, as well as water and food samples, were collected to test for potential bacteria and viruses. Results A total of 924 cases fit the definition of the probable case, including 8 cases of laboratory-confirmed norovirus infection at 13 schools in Jiaxing city between February 12 and February 21, 2014. The case-control study demonstrated that barrelled water was a risk factor (OR: 20.15, 95% CI: 2.59–156.76) and that bottled water and boiled barrelled water were protective factors (OR: 0.31, 95% CI: 0.13–0.70, and OR: 0.36, 95% CI: 0.16–0.77). A total of 11 rectal samples and 8 barrelled water samples were detected as norovirus-positive, and the genotypes of viral strains were the same (GII). The norovirus that contaminated the barrelled water largely came from the asymptomatic workers. Conclusions This acute gastroenteritis outbreak was caused by barrelled water contaminated by norovirus. The outbreak was controlled after stopping the supply of barrelled water. The barrelled water supply in China represents a potential source of acute gastroenteritis outbreaks due to the lack of surveillance and supervision

  17. Sr{sub 1.98}Eu{sub 0.02}SiO{sub 4} luminescence whisker based on vapor-phase deposition: Facile synthesis, uniform morphology and enhanced luminescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jian, E-mail: xujian@stu.xmu.edu.cn [Department of Materials Science and Engineering, Xiamen University, Xiamen 361005 (China); Hassan, Dhia A. [Department of Materials Science and Engineering, Xiamen University, Xiamen 361005 (China); Department of Chemistry, College of Education for Pure Science, University of Basrah, 61004 (Iraq); Zeng, Renjie; Peng, Dongliang [Department of Materials Science and Engineering, Xiamen University, Xiamen 361005 (China); Fujian Key Lab of Advanced Special Material, Xiamen University, Xiamen 361005 (China); Key Laboratory of High Performance Ceramic Fibers, Ministry of Education, Xiamen 361005 (China)

    2015-11-15

    Highlights: • For the first time, it is possible to obtain Sr{sub 1.98}Eu{sub 0.02}SiO{sub 4} whisker. • The whiskers are smooth and uniform with L/D ratio over 50. • Durability and thermal stability of the whisker are enhanced. - Abstract: A high performance strontium silicate phosphor has been successfully synthesized though a facile vapor-phase deposition method. The product consists of single crystal whiskers which are smooth and uniform, and with a sectional equivalent diameter of around 5 μm; the aspect ratio is over 50 and no agglomeration can be observed. X-ray diffraction result confirmed that the crystal structure of the whisker was α’-Sr{sub 2}SiO{sub 4}. The exact chemical composition was Sr{sub 1.98}Eu{sub 0.02}SiO{sub 4} which was analyzed by energy dispersive spectrometer and inductively coupled plasma-mass spectrometer. The whisker shows broad green emission with peak at 523 nm ranging from 470 to 600 nm (excited at 370 nm). Compared with traditional Sr{sub 2}SiO{sub 4}:Eu phosphor, durability (at 85% humidity and 85 °C) and thermal stability of the whisker are obviously improved. Moreover, growth mechanism of the Sr{sub 1.98}Eu{sub 0.02}SiO{sub 4} whiskers is Vapor–Liquid–Solid. On a macro-scale, the product is still powder which makes it suitable for the current packaging process of WLEDs.

  18. Effects of Cortical Spreading Depression on Synaptic Activity, Blood Flow and Oxygen Consumption in Rat Cerebral Cortex

    DEFF Research Database (Denmark)

    Hansen, Henning Piilgaard

    2010-01-01

    As the title of this thesis indicates I have during my PhD studied the effects of cortical spreading depression (CSD) on synaptic activity, blood flow and oxygen consumption in rat cerebral cortex. This was performed in vivo using an open cranial window approach in anesthetized rats. I applied...... parameters of the whisker/infraorbital nerve etwork (IO) targeting the same cortical area. We tested the hypothesis that the relation between increases in CBF and CMRO2 evoked by stimulation and synaptic activity differed for the two activated networks and that activation of two distinct networks activate...

  19. Electrical transport effects due to oxygen content modifications in a Bi2Sr2CaCu2O8+δ superconducting whisker

    International Nuclear Information System (INIS)

    Cagliero, Stefano; Agostino, Angelo; Bonometti, Elisabetta; Truccato, Marco

    2007-01-01

    We report a set of resistivity measurements along the a-axis of a Bi 2 Sr 2 CaCu 2 O 8+δ microscopic superconducting whisker. The effect of the storage environment on sample ageing has been studied, considering both an air atmosphere at 273 K and a helium atmosphere at about 300 K for an overall storage time of about 100 days. It is clearly shown that the material underwent a remarkable resistivity increase of 26% at 260 K accompanied by a decrease in the critical temperature of 0.6 K during the whole ageing period. The helium atmosphere increased the average process rate by about two orders of magnitude. The present results are in agreement with previous findings on room temperature structural modifications in Bi 2 Sr 2 CaCu 2 O 8+δ whiskers and can be ascribed to oxygen depletion phenomena from the material

  20. Fabrication of SiC Composites with Synergistic Toughening of Carbon Whisker and In Situ 3C-SiC Nanowire

    Directory of Open Access Journals (Sweden)

    Zhang Yunlong

    2016-01-01

    Full Text Available The SiC composites with synergistic toughening of carbon whisker and in situ 3C-SiC nanowire have been fabricated by hot press sinter technology and annealed treatment technology. Effect of annealed time on the morphology of SiC nanowires and mechanical properties of the Cw/SiC composites was surveyed in detail. The appropriate annealed time improved mechanical properties of the Cw/SiC composites. The synergistic effect of carbon whisker and SiC nanowire can improve the fracture toughness for Cw/SiC composites. The vapor-liquid-solid growth (VLS mechanism was proposed. TEM photo showed that 3C-SiC nanowire can be obtained with preferential growth plane ({111}, which corresponded to interplanar spacing about 0.25 nm.

  1. Dynamic mixed state in micron bridges on the basis of Bi sub 2 Sr sub 2 CaCu sub 2 O sub x whiskers

    CERN Document Server

    Zybtsev, S G; Pokrovskii, V Yu

    2001-01-01

    One studied destruction of superconductivity by current in BSCCO (2212) single-crystal whiskers and in bridges based on them with dimensions of the order of the magnetic field penetration efficient depth. One measured the volt-ampere characteristics (VAC) of micron bridges made of Bi sub 2 Sr sub 2 CaCu sub 2 O sub x single-crystal whiskers. It was detected that at temperatures below temperature of superconducting transition in VAC one observed current quasi-periodic abrupt changes of voltage with portions of the constant differential resistance the value of which was proportional to the number of abrupt change. In the narrowest (0.5-1 mu m) bridges one observed up to 10 abrupt changes of voltage. The result is explained by formation of vortex lines under the effect of current

  2. Extraction and characterization of cellulose nano whiskers from balsa wood; Extracao e caracterizacao de nanocristais de celulose obtidos da madeira balsa

    Energy Technology Data Exchange (ETDEWEB)

    Morelli, Carolina L.; Bretas, Rosario E.S., E-mail: bretas@ufscar.br [Universidade Federal de Sao Carlos - UFSCar, Sao Carlos, SP (Brazil); Marconcini, Jose M. [Embrapa Instrumentacao, Sao Carlos, SP (Brazil); Pereira, Fabiano V. [Universidade Federal de Minas Gerais - UFMG, Belo Horizonte, MG (Brazil); Branciforti, Marcia C. [Universidade de Sao Paulo - USP, Sao Carlos, SP (Brazil)

    2011-07-01

    In this study cellulose nano whiskers were obtained from balsa wood. For this purpose, fibers of balsa wood were subjected to hydrolysis reactions for lignin and hemi cellulose digestion and acquisition of nano-scale cellulose. Cellulose nano crystals obtained had medium length and thickness of 176 nm and 7 nm respectively. Infrared spectroscopy and x-ray diffraction showed that the process used for extracting nano whiskers could digest nearly all the lignin and hemi cellulose from the balsa fiber and still preserve the aspect ratio and crystallinity, satisfactory enough for future application in polymer nano composites. Thermogravimetry showed that the onset temperature of thermal degradation of cellulose nano crystals (226 degree C) was higher than the temperature of the balsa fiber (215 degree C), allowing its use in molding processes with many polymers from the molten state.(author)

  3. Real-time observation of growth and orientation of Sm-Ba-Cu-O phases on a Sm-211 whisker substrate by high-temperature optical microscopy

    Czech Academy of Sciences Publication Activity Database

    Sun, J.L.; Huang, Y.B.; Cheng, L.; Yao, X.; Lai, Y.J.; Jirsa, Miloš

    2009-01-01

    Roč. 9, č. 2 (2009), 898-902 ISSN 1528-7483 R&D Projects: GA ČR GA202/08/0722 Institutional research plan: CEZ:AV0Z10100520 Keywords : high-temperature optical microscopy * growth and orientation of Sm-Ba-Cu-O phases * Sm-211 whisker substrate Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.162, year: 2009

  4. The design and performance of a twenty barrel hydrogen pellet injector for Alcator C-Mod

    International Nuclear Information System (INIS)

    Urbahn, J.A.

    1994-05-01

    A twenty barrel hydrogen pellet injector has been designed, built and tested both in the laboratory and on the Alcator C-Mod Tokamak at MIT. The injector functions by firing pellets of frozen hydrogen or deuterium deep into the plasma discharge for the purpose of fueling the plasma, modifying the density profile and increasing the global energy confinement time. The design goals of the injector are: (1) Operational flexibility, (2) High reliability, (3) Remote operation with minimal maintenance. These requirements have lead to a single stage, pipe gun design with twenty barrels. Pellets are formed by in- situ condensation of the fuel gas, thus avoiding moving parts at cryogenic temperatures. The injector is the first to dispense with the need for cryogenic fluids and instead uses a closed cycle refrigerator to cool the thermal system components. The twenty barrels of the injector produce pellets of four different size groups and allow for a high degree of flexibility in fueling experiments. Operation of the injector is under PLC control allowing for remote operation, interlocked safety features and automated pellet manufacturing. The injector has been extrusively tested and shown to produce pellets reliably with velocities up to 1400 m/sec. During the period from September to November of 1993, the injector was successfully used to fire pellets into over fifty plasma discharges. Experimental results include data on the pellet penetration into the plasma using an advanced pellet tracking diagnostic with improved time and spatial response. Data from the tracker indicates pellet penetrations were between 30 and 86 percent of the plasma minor radius

  5. Evaporating short-circuits in the ATLAS liquid argon barrel presampler 006

    CERN Document Server

    Belhorma, B; Lund-Jensen, B; Rydström, S; Yamouni, M

    2005-01-01

    A technique to eliminate or limit the implications of short-circuits in the ATLAS barrel presampler is described. A high voltage capacitor with a large capacity is charged at different high voltages and discharged through the short-circuit which allows either to disintegrate the dust being the origin of the short-circuit, or to burn away a thin etched copper strip which acts as a fuse on the corresponding presampler anode. This effect is possible even in the presence of a resistive HV cable (10 to 30 ohms) in series which dampens the pulse.

  6. Correlations decrease with propagation of spiking activity in the mouse barrel cortex

    Directory of Open Access Journals (Sweden)

    Gayathri Nattar Ranganathan

    2011-05-01

    Full Text Available Propagation of suprathreshold spiking activity through neuronal populations is important for the function of the central nervous system. Neural correlations have an impact on cortical function particularly on the signaling of information and propagation of spiking activity. Therefore we measured the change in correlations as suprathreshold spiking activity propagated between recurrent neuronal networks of the mammalian cerebral cortex. Using optical methods we recorded spiking activity from large samples of neurons from two neural populations simultaneously. The results indicate that correlations decreased as spiking activity propagated from layer 4 to layer 2/3 in the rodent barrel cortex.

  7. Design, performance, and calibration of CMS hadron-barrel calorimeter wedges

    International Nuclear Information System (INIS)

    Abdullin, S.; Abramov, V.; Goncharov, P.; Khmelnikov, A.; Korablev, A.; Korneev, Y.; Krinitsyn, A.; Kryshkin, V.; Lukanin, V.; Pikalov, V.; Ryazanov, A.; Talov, V.; Turchanovich, L.; Volkov, A.; Acharya, B.; Banerjee, S.; Banerjee, S.; Chendvankar, S.; Dugad, S.; Kalmani, S.; Katta, S.; Mazumdar, K.; Mondal, N.; Nagaraj, P.; Patil, M.; Reddy, L.; Satyanarayana, B.; Sudhakar, K.; Verma, P.; Adams, M.; Burchesky, K.; Qian, W.; Akchurin, N.; Carrell, K.; Guemues, K.; Thomas, R.; Akgun, U.; Ayan, S.; Duru, F.; Merlo, J.P.; Mestvirishvili, A.; Miller, M.; Norbeck, E.; Olson, J.; Onel, Y.; Schmidt, I.; Anderson, E.W.; Hauptman, J.; Antchev, G.; Hazen, E.; Lawlor, C.; Machado, E.; Posch, C.; Rohlf, J.; Wu, S.X.; Aydin, S.; Dumanoglu, I.; Eskut, E.; Kayis-Topaksu, A.; Polatoz, A.; Onengut, G.; Ozdes-Koca, N.; Baarmand, M.; Ralich, R.; Vodopiyanov, I.; Baden, D.; Bard, R.; Eno, S.; Grassi, T.; Jarvis, C.; Kellogg, R.; Kunori, S.; Skuja, A.; Barnes, V.; Laasanen, A.; Pompos, A.; Bawa, H.; Beri, S.; Bhatnagar, V.; Kaur, M.; Kohli, J.; Kumar, A.; Singh, J.; Baiatian, G.; Sirunyan, A.; Bencze, G.; Vesztergombi, G.; Zalan, P.; Bodek, A.; Budd, H.; Chung, Y.; De Barbaro, P.; Haelen, T.; Camporesi, T.; Visser, T. de; Cankocak, K.; Cremaldi, L.; Reidy, J.; Sanders, D.A.; Cushman, P.; Sherwood, B.; Damgov, J.; Dimitrov, L.; Genchev, V.; Piperov, S.; Vankov, I.; Demianov, A.; Ershov, A.; Gribushin, A.; Kodolova, O.; Petrushanko, S.; Sarycheva, L.; Vardanyan, I.; Elias, J.; Elvira, D.; Freeman, J.; Green, D.; Los, S.; O'Dell, V.; Ronzhin, A.; Sergeyev, S.; Suzuki, I.; Vidal, R.; Whitmore, J.; Emeliantchik, I.; Massolov, V.; Shumeiko, N.; Stefanovich, R.; Fisher, W.; Tully, C.; Gavrilov, V.; Kaftanov, V.; Kisselevich, I.; Kolossov, V.; Krokhotin, A.; Kuleshov, S.; Stolin, V.; Ulyanov, A.; Gershtein, Y.; Golutvin, I.; Kalagin, V.; Kosarev, I.; Mescheryakov, G.; Smirnov, V.; Volodko, A.; Zarubin, A.; Grinev, B.; Lubinsky, V.; Senchishin, V.; Guelmez, E.; Hagopian, S.; Hagopian, V.; Johnson, K.; Heering, A.; Imboden, M.; Isiksal, E.; Karmgard, D.; Ruchti, R.; Kaya, M.; Lazic, D.; Levchuk, L.; Sorokin, P.; Litvintsev, D.; Litov, L.; Mans, J.; Ozkorucuklu, S.; Ozok, F.; Serin-Zeyrek, M.; Sever, R.; Zeyrek, M.; Paktinat, S.; Podrasky, V.; Sanzeni, C.; Winn, D.; Vlassov, E.

    2008-01-01

    Extensive measurements have been made with pions, electrons and muons on four production wedges of the compact muon solenoid (CMS) hadron barrel (HB) calorimeter in the H2 beam line at CERN with particle momenta varying from 20 to 300 GeV/c. The time structure of the events was measured with the full chain of preproduction front-end electronics running at 34 MHz. Moving-wire radioactive source data were also collected for all scintillator layers in the HB. The energy dependent time slewing effect was measured and tuned for optimal performance. (orig.)

  8. Precise Mapping of the Magnetic Field in the CMS Barrel Yoke using Cosmic Rays

    CERN Document Server

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Osborne, I; Paul, T; Reucroft, S; Swain, J; Taylor, L; Tuura, L; Anastassov, A; Gobbi, B; Kubik, A; Ofierzynski, R A; Pozdnyakov, A; Schmitt, M; Stoynev, S; Velasco, M; Won, S; Antonelli, L; Berry, D; Hildreth, M; Jessop, C; Karmgard, D J; Kolberg, T; Lannon, K; Lynch, S; Marinelli, N; Morse, D M; Ruchti, R; Slaunwhite, J; Warchol, J; Wayne, M; Bylsma, B; Durkin, L S; Gilmore, J; Gu, J; Killewald, P; Ling, T Y; Williams, G; Adam, N; Berry, E; Elmer, P; Garmash, A; Gerbaudo, D; Halyo, V; Hunt, A; Jones, J; Laird, E; Marlow, D; Medvedeva, T; Mooney, M; Olsen, J; Piroué, P; Stickland, D; Tully, C; Werner, J S; Wildish, T; Xie, Z; Zuranski, A; Acosta, J G; Bonnett Del Alamo, M; Huang, X T; Lopez, A; Mendez, H; Oliveros, S; Ramirez Vargas, J E; Santacruz, N; Zatzerklyany, A; Alagoz, E; Antillon, E; Barnes, V E; Bolla, G; Bortoletto, D; Everett, A; Garfinkel, A F; Gecse, Z; Gutay, L; Ippolito, N; Jones, M; Koybasi, O; Laasanen, A T; Leonardo, N; Liu, C; Maroussov, V; Merkel, P; Miller, D H; Neumeister, N; Sedov, A; Shipsey, I; Yoo, H D; Zheng, Y; Jindal, P; Parashar, N; Cuplov, V; Ecklund, K M; Geurts, F J M; Liu, J H; Maronde, D; Matveev, M; Padley, B P; Redjimi, R; Roberts, J; Sabbatini, L; Tumanov, A; Betchart, B; Bodek, A; Budd, H; Chung, Y S; de Barbaro, P; Demina, R; Flacher, H; Gotra, Y; Harel, A; Korjenevski, S; Miner, D C; Orbaker, D; Petrillo, G; Vishnevskiy, D; Zielinski, M; Bhatti, A; Demortier, L; Goulianos, K; Hatakeyama, K; Lungu, G; Mesropian, C; Yan, M; Atramentov, O; Bartz, E; Gershtein, Y; Halkiadakis, E; Hits, D; Lath, A; Rose, K; Schnetzer, S; Somalwar, S; Stone, R; Thomas, S; Watts, T L; Cerizza, G; Hollingsworth, M; Spanier, S; Yang, Z C; York, A; Asaadi, J; Aurisano, A; Eusebi, R; Golyash, A; Gurrola, A; Kamon, T; Nguyen, C N; Pivarski, J; Safonov, A; Sengupta, S; Toback, D; Weinberger, M; Akchurin, N; Berntzon, L; Gumus, K; Jeong, C; Kim, H; Lee, S W; Popescu, S; Roh, Y; Sill, A; Volobouev, I; Washington, E; Wigmans, R; Yazgan, E; Engh, D; Florez, C; Johns, W; Pathak, S; Sheldon, P; Andelin, D; Arenton, M W; Balazs, M; Boutle, S; Buehler, M; Conetti, S; Cox, B; Hirosky, R; Ledovskoy, A; Neu, C; Phillips II, D; Ronquest, M; Yohay, R; Gollapinni, S; Gunthoti, K; Harr, R; Karchin, P E; Mattson, M; Sakharov, A; Anderson, M; Bachtis, M; Bellinger, J N; Carlsmith, D; Crotty, I; Dasu, S; Dutta, S; Efron, J; Feyzi, F; Flood, K; Gray, L; Grogg, K S; Grothe, M; Hall-Wilton, R; Jaworski, M; Klabbers, P; Klukas, J; Lanaro, A; Lazaridis, C; Leonard, J; Loveless, R; Magrans de Abril, M; Mohapatra, A; Ott, G; Polese, G; Reeder, D; Savin, A; Smith, W H; Sourkov, A; Swanson, J; Weinberg, M; Wenman, D; Wensveen, M; White, A

    2010-01-01

    The CMS detector is designed around a large 4 T superconducting solenoid, enclosed in a 12000-tonne steel return yoke. A detailed map of the magnetic field is required for the accurate simulation and reconstruction of physics events in the CMS detector, not only in the inner tracking region inside the solenoid but also in the large and complex structure of the steel yoke, which is instrumented with muon chambers. Using a large sample of cosmic muon events collected by CMS in 2008, the field in the steel of the barrel yoke has been determined with a precision of 3 to 8% depending on the location.

  9. Upgrade of the CMS muon trigger system in the barrel region

    International Nuclear Information System (INIS)

    Rabady, Dinyar; Ero, Janos; Flouris, Giannis; Fulcher, Jonathan; Loukas, Nikitas; Paradas, Evangelos; Reis, Thomas; Sakulin, Hannes; Wulz, Claudia-Elisabeth

    2017-01-01

    To maintain the excellent performance shown during the LHC's Run-1 the Level-1 Trigger of the Compact Muon Solenoid experiment underwent a significant upgrade. One part of this upgrade is the re-organization of the muon trigger path from a subsystem-centric view in which hits in the drift tubes (DT), the cathode strip chambers (CSC), and the resistive plate chambers (RPC) were treated separately in dedicated track-finding systems to one in which complementary detector systems for a given region (barrel, overlap, and endcap) are merged at the track-finding level. This fundamental restructuring of the muon trigger system required the development of a system to receive track candidates from the track-finding layer, remove potential duplicate tracks, and forward the best candidates to the global decision layer. An overview will be given of the new track-finder system for the barrel region, the Barrel Muon Track Finder (BMTF), as well as the cancel-out and sorting layer: the upgraded Global Muon Trigger (μGMT). Both the BMTF and μGMT have been implemented in a Xilinx Virtex-7 card utilizing the microTCA architecture. While the BMTF improves on the proven and well-tested algorithms used in the Drift Tube Track Finder during Run-1, the μGMT is an almost complete re-development due to the re-organization of the underlying systems from track-finders for a specific detector to regional track finders covering a given area of the whole detector. Additionally the μGMT calculates a muon's isolation using energy information received from the calorimeter trigger. This information is added to the muon objects forwarded to the global decision layer, the so-called Global Trigger. - Highlights: • Presented upgraded Global Muon Trigger and Barrel Muon Track Finder systems. • Upgraded system moves from sub-detector centric view to geometric-view. • To improve trigger performance. • Common hardware improves maintainability and increases development speed. • Use of

  10. Precise mapping of the magnetic field in the CMS barrel yoke using cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Chatrchyan, S. [Yerevan Physics Institute (Aremenia); et al.,

    2010-03-01

    The CMS detector is designed around a large 4 T superconducting solenoid, enclosed in a 12000-tonne steel return yoke. A detailed map of the magnetic field is required for the accurate simulation and reconstruction of physics events in the CMS detector, not only in the inner tracking region inside the solenoid but also in the large and complex structure of the steel yoke, which is instrumented with muon chambers. Using a large sample of cosmic muon events collected by CMS in 2008, the field in the steel of the barrel yoke has been determined with a precision of 3 to 8% depending on the location.

  11. The drift velocity monitoring system of the CMS barrel muon chambers

    CERN Document Server

    Altenhoefer, Georg Friedrich; Heidemann, Carsten Andreas; Reithler, Hans; Sonnenschein, Lars; Teyssier, Daniel Francois

    2017-01-01

    The drift velocity is a key parameter of drift chambers. Its value depends on several parameters: electric field, pressure, temperature, gas mixture, and contamination, for example, by ambient air. A dedicated Velocity Drift Chamber (VDC) with 1-L volume has been built at the III. Phys. Institute A, RWTH Aachen, in order to monitor the drift velocity of all CMS barrel muon Drift Tube chambers. A system of six VDCs was installed at CMS and has been running since January 2011. We present the VDC monitoring system, its principle of operation, and measurements performed.

  12. The drift velocity monitoring system of the CMS barrel muon chambers

    Science.gov (United States)

    Altenhöfer, Georg; Hebbeker, Thomas; Heidemann, Carsten; Reithler, Hans; Sonnenschein, Lars; Teyssier, Daniel

    2018-04-01

    The drift velocity is a key parameter of drift chambers. Its value depends on several parameters: electric field, pressure, temperature, gas mixture, and contamination, for example, by ambient air. A dedicated Velocity Drift Chamber (VDC) with 1-L volume has been built at the III. Phys. Institute A, RWTH Aachen, in order to monitor the drift velocity of all CMS barrel muon Drift Tube chambers. A system of six VDCs was installed at CMS and has been running since January 2011. We present the VDC monitoring system, its principle of operation, and measurements performed.

  13. Progress in the construction of the B0 model of the ATLAS Barrel Toroid magnet

    CERN Document Server

    Acerbi, E; Ambrosio, G; Baccaglioni, G; Broggi, F; Rossi, L; Sorbi, M; Volpini, G

    2000-01-01

    The ATLAS Barrel Toroid air-core magnet (BT) will be composed by 8 superconducting coils, each one 25 m long and 5 m wide. In order to validate the technologies and manufacturing processes, a smaller model (9 m long) of one BT coil, named B0, is now under construction. This paper presents a general overview of the B0 project status, with special regard to the components for which the LASA Lab. is responsible: (a) the aluminium-clad NbTi conductor; (b) the double coils winding and impregnation; (c) the components of the cryostat (vacuum chamber, thermal shield and suspension rod). (6 refs).

  14. Projects to get you off the grid rain barrels, chicken coops, and solar panels

    CERN Document Server

    Instructablescom

    2014-01-01

    Instructables is back with this compact book focused on a series of projects designed to get you thinking creatively about thinking green. Twenty Instructables illustrate just how simple it can be to make your own backyard chicken coop, or turn a wine barrel into a rainwater collector.Illustrated with dozens of full-color photographs per project accompanying easy-to-follow instructions, this Instructables collection utilizes the best that the online community has to offer, turning a far-reaching group of people into a mammoth database churning out ideas to make life better, easier, and in this

  15. The inclusion of RPC only segments in the Barrel Muon Track Finder

    CERN Document Server

    CMS Collaboration

    2018-01-01

    On November 3, 2017 during the LHC fill 6360 and from the run number 306121 RPC-only segments were enable to trigger. In this document we show the impact of the RPC-only segments in the Barrel Muon Track Finder efficiency performance. The efficiency measurement was done with Tag and Probe cut and count following the Muon POG working point recommendations (tight ID and Particle Flow isolation requirements more details can be found in https://cds.cern.ch/record/2054113). The used dataset was ZMuMu corresponding to each period.

  16. High precision, low disturbance calibration of the High Voltage system of the CMS Barrel Electromagnetic Calorimeter

    CERN Document Server

    Fasanella, Giuseppe

    2017-01-01

    The CMS Electromagnetic Calorimeter utilizes scintillating lead tungstate crystals, with avalanche photodiodes (APD) as photo-detectors in the barrel part. 1224 HV channels bias groups of 50 APD pairs, each at a voltage of about 380 V. The APD gain dependence on the voltage is 3pct/V. A stability of better than 60 mV is needed to have negligible impact on the calorimeter energy resolution. Until 2015 manual calibrations were performed yearly. A new calibration system was deployed recently, which satisfies the requirement of low disturbance and high precision. The system is discussed in detail and first operational experience is presented.

  17. High precision, low disturbance calibration of the High Voltage system of the CMS Barrel Electromagnetic Calorimeter

    CERN Document Server

    Marzocchi, Badder

    2017-01-01

    The CMS Electromagnetic Calorimeter is made of scintillating lead tungstate crystals, using avalanche photodiodes (APD) as photo-detectors in the barrel part. The high voltage system, consisting of 1224 channels, biases groups of 50 APD pairs, each at a voltage of about 380 V. The APD gain dependence on the voltage is 3pct/V. A stability of better than 60 mV is needed to have negligible impact on the calorimeter energy resolution. Until 2015 manual calibrations were performed yearly. A new calibration system was deployed recently, which satisfies the requirement of low disturbance and high precision. The system is discussed in detail and first operational experience is presented.

  18. High precision, low disturbance calibration of the High Voltage system of the CMS Barrel Electromagnetic Calorimeter

    CERN Document Server

    Fasanella, Giuseppe

    2016-01-01

    The CMS Electromagnetic Calorimeter utilizes scintillating lead tungstate crystals, with avalanche photodiodes (APD) as photo-detectors in the barrel part. 1224 HV channels bias groups of 50 APD pairs, each at a voltage of about 380 V. The APD gain dependence on the voltage is 3pct/V. A stability of better than 60 mV is needed to have negligible impact on the calorimeter energy resolution. Until 2015 manual calibrations were performed yearly. A new calibration system was deployed recently, which satisfies the requirement of low disturbance and high precision. The system is discussed in detail and first operational experience is presented.

  19. Upgrade of the CMS muon trigger system in the barrel region

    Energy Technology Data Exchange (ETDEWEB)

    Rabady, Dinyar, E-mail: dinyar.rabady@cern.ch [Institute of High Energy Physics Vienna (HEPHY), Nikolsdorfer Gasse 18, 1050 Wien (Austria); Ero, Janos [Institute of High Energy Physics Vienna (HEPHY), Nikolsdorfer Gasse 18, 1050 Wien (Austria); Flouris, Giannis [University of Ioannina, 45110 Ioannina (Greece); Fulcher, Jonathan [CERN, 1211 Geneve 23 (Switzerland); Loukas, Nikitas; Paradas, Evangelos [University of Ioannina, 45110 Ioannina (Greece); Reis, Thomas; Sakulin, Hannes; Wulz, Claudia-Elisabeth [CERN, 1211 Geneve 23 (Switzerland)

    2017-02-11

    To maintain the excellent performance shown during the LHC's Run-1 the Level-1 Trigger of the Compact Muon Solenoid experiment underwent a significant upgrade. One part of this upgrade is the re-organization of the muon trigger path from a subsystem-centric view in which hits in the drift tubes (DT), the cathode strip chambers (CSC), and the resistive plate chambers (RPC) were treated separately in dedicated track-finding systems to one in which complementary detector systems for a given region (barrel, overlap, and endcap) are merged at the track-finding level. This fundamental restructuring of the muon trigger system required the development of a system to receive track candidates from the track-finding layer, remove potential duplicate tracks, and forward the best candidates to the global decision layer. An overview will be given of the new track-finder system for the barrel region, the Barrel Muon Track Finder (BMTF), as well as the cancel-out and sorting layer: the upgraded Global Muon Trigger (μGMT). Both the BMTF and μGMT have been implemented in a Xilinx Virtex-7 card utilizing the microTCA architecture. While the BMTF improves on the proven and well-tested algorithms used in the Drift Tube Track Finder during Run-1, the μGMT is an almost complete re-development due to the re-organization of the underlying systems from track-finders for a specific detector to regional track finders covering a given area of the whole detector. Additionally the μGMT calculates a muon's isolation using energy information received from the calorimeter trigger. This information is added to the muon objects forwarded to the global decision layer, the so-called Global Trigger. - Highlights: • Presented upgraded Global Muon Trigger and Barrel Muon Track Finder systems. • Upgraded system moves from sub-detector centric view to geometric-view. • To improve trigger performance. • Common hardware improves maintainability and increases development speed. • Use of

  20. The Crystal Barrel: Meson Spectroscopy at LEAR with a 4$\\pi$ Detector

    CERN Multimedia

    2002-01-01

    % PS197 \\\\ \\\\The Crystal Barrel is a 4$\\pi$ spectrometer designed to provide complete and precise information on practically every final state produced in $\\bar{p} p $ and $\\bar{p}d $ annihilations at low energy and to collect high statistics data samples. Selective triggers can be applied when necessary. \\\\ \\\\The physics goal is to identify all light mesons in the mass range from 0.14 to 2.3~GeV/c$^{2}$, to determine their quantum numbers and decay properties and to study the annihilation dynamics. The main interest is to find the glueball and hybrid degrees of freedom predicted in the framework of Quantum Chromodynamics. \\\\ \\\\\

  1. Overview of the 63000 PWO Barrel Crystals for CMS_ECAL Production

    CERN Document Server

    Auffray, E

    2008-01-01

    In March 2007, the PWO crystal production for the barrel part of the CMS electromagnetic calorimeter has been completed. Since September 1998, 63000 crystals (61000 in Russia, 2000 in China) have been produced, received and tested in two regional centers (CERN and INFN Rome). This paper presents an overview of the procedures used from the R&D phase up to the final large scale reception and quality control. The crystals characteristics and the lessons learned from the production of this unprecedented amount of crystals in a HEP experiment are also presented.

  2. Design, performance, and calibration of CMS hadron-barrel calorimeter wedges

    Energy Technology Data Exchange (ETDEWEB)

    Abdullin, S. [Fermi National Accelerator Lab., Batavia, IL (United States)]|[Univ. of Maryland, College Park, MD (United States); Abramov, V.; Goncharov, P.; Khmelnikov, A.; Korablev, A.; Korneev, Y.; Krinitsyn, A.; Kryshkin, V.; Lukanin, V.; Pikalov, V.; Ryazanov, A.; Talov, V.; Turchanovich, L.; Volkov, A. [IHEP, Protvino (Russian Federation); Acharya, B.; Banerjee, S.; Banerjee, S.; Chendvankar, S.; Dugad, S.; Kalmani, S.; Katta, S.; Mazumdar, K.; Mondal, N.; Nagaraj, P.; Patil, M.; Reddy, L.; Satyanarayana, B.; Sudhakar, K.; Verma, P. [Tata Inst. of Fundamental Research, Mumbai (India); Adams, M.; Burchesky, K.; Qian, W. [Univ. of Illinois at Chicago, Chicago, IL (United States); Akchurin, N.; Carrell, K.; Guemues, K.; Thomas, R. [Texas Tech Univ., Dept. of Physics, Lubbock, TX (United States); Akgun, U.; Ayan, S.; Duru, F.; Merlo, J.P.; Mestvirishvili, A.; Miller, M.; Norbeck, E.; Olson, J.; Onel, Y.; Schmidt, I. [Univ. of Iowa, Iowa City, IA (United States); Anderson, E.W.; Hauptman, J. [Iowa State Univ., Ames, IA (United States); Antchev, G.; Hazen, E.; Lawlor, C.; Machado, E.; Posch, C.; Rohlf, J.; Wu, S.X. [Boston Univ., Boston, MA (United States); Aydin, S.; Dumanoglu, I.; Eskut, E.; Kayis-Topaksu, A.; Polatoz, A.; Onengut, G.; Ozdes-Koca, N. [Cukurova Univ., Adana (Turkey); Baarmand, M.; Ralich, R.; Vodopiyanov, I. [Florida Inst. of Technology, Melbourne, FL (United States); Baden, D.; Bard, R.; Eno, S.; Grassi, T.; Jarvis, C.; Kellogg, R.; Kunori, S.; Skuja, A. [Univ. of Maryland, College Park, MD (United States); Barnes, V.; Laasanen, A.; Pompos, A. [Purdue Univ., West Lafayette, IN (United States); Bawa, H.; Beri, S.; Bhatnagar, V.; Kaur, M.; Kohli, J.; Kumar, A.; Singh, J. [Panjab Univ., Chandigarh (India); Baiatian, G.; Sirunyan, A. [Yerevan Physics Inst., Yerevan (Armenia); Bencze, G.; Vesztergombi, G.; Zalan, P. [KFKI-RMKI, Research Inst. for Particle and Nuclear Physics, Budapest (Hungary)] [and others

    2008-05-15

    Extensive measurements have been made with pions, electrons and muons on four production wedges of the compact muon solenoid (CMS) hadron barrel (HB) calorimeter in the H2 beam line at CERN with particle momenta varying from 20 to 300 GeV/c. The time structure of the events was measured with the full chain of preproduction front-end electronics running at 34 MHz. Moving-wire radioactive source data were also collected for all scintillator layers in the HB. The energy dependent time slewing effect was measured and tuned for optimal performance. (orig.)

  3. Responses of vibrissa-sensitive cortical neurons in normal and prenatally x-irradiated rat

    International Nuclear Information System (INIS)

    Ito, M.; Kawabata, M.; Shoji, R.

    1979-01-01

    Rats were irradiated by 200 R of x ray on day 17 of gestation through the body wall of the mother. When they underwent the following electrophysiological tests at the age of 3 to 4 month, the somatosensory cortex showed a lack of layers II, III, IV, and Va. Spike responses to quick whisker deflections were recorded from single cells in the somatosenory cortex of normal and prenatally x-irradiated rats. For the irradiated rats the response latency was prolonged when compared to the normal controls. Cortical laminar analysis of field potentials revealed that there was no difference in the latency of these potentials between the two groups, suggesting that vibrissal sensory signals reach the cortical level normally even in the irradiated rats. The prolonged latency of the irradiated cortical neuronal response could thus be ascribed to an abnormal intracortical delay, which was most likely associated with the failure of development of layer IV stellate cells in these preparations

  4. Upgrade of the ATLAS Muon Barrel Trigger for HL-LHC

    CERN Document Server

    Romano, Marino; The ATLAS collaboration

    2015-01-01

    The present ATLAS muon trigger in the barrel region (|eta|<1.05) is based on three layers of RPC chambers. It was designed to run for 10 years at the LHC luminosity of 10^{34} cm^{-2}s^{-1} and operated successfully and with high selectivity during the first run of the LHC. In order to ensure a stable performance of the RPCs until 2035 at the higher rates and at luminosities of 5-7x10^{34} cm^{-2}s^{-1} provided by HL-LHC, the chambers will have to be operated with reduced gas gain to respect the original design limits on currents and integrated charge. The ATLAS muon collaboration proposes an upgrade of the system by installing an inner layer of new generation RPCs during the LHC shutdown expected for the year 2023. This new layer will increase the system redundancy and therefore allow operation with high efficiency and high selectivity during the HL-LHC phase. The insertion of this new layer will also increase the geometrical acceptance in the barrel region from 75% to 95%. Moreover, the additional measu...

  5. Upgrade of the ATLAS Muon Barrel Trigger for HL-LHC.

    CERN Document Server

    Biondi, Silvia; The ATLAS collaboration

    2015-01-01

    The present ATLAS muon trigger in the barrel region (|η | < 1.05) is based on three layers of RPC chambers. It was designed to run for 10 years at the LHC luminosity of 1034cm−2s−1 and operated successfully and with high selectivity during the first run of the LHC. In order to ensure a stable performance of the RPCs until 2035 at the higher rates and at luminosities of 5−7x1034cm−2s−1 provided by HL-LHC, the chambers will have to be operated with reduced gas gain to respect the original design limits on currents and integrated charge. The ATLAS muon collaboration proposes an upgrade of the system by installing an inner layer of new generation RPCs during the LHC shutdown expected for the year 2023. This new layer will increase the system redundancy and therefore allow operation with high efficiency and high selectivity during the HL-LHC phase. The insertion of this new layer will also increase the geometrical acceptance in the barrel region from 75% to 95%. Moreover, the additional measurements ...

  6. Insertion of the first half-barrel of the ATLAS electromagnetic calorimeter into its cryostat

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    The first cylinder of the ATLAS electromagnetic calorimeter barrel and the presampler have been inserted in the cryostat.The ATLAS electromagnetic calorimeter is intended to detect electrons, positrons and photons by measuring the energy they deposit on being absorbed. The cylinder of the calorimeter is in two halves, that will be sunk in a liquid-argon bath cooled to 90 kelvin (-180°C). Each half-barrel is 3.2 metres long, 53 cm thick and formed by assembling 16 modules. Each module is made up of alternate lead absorbers and electrodes pressed into 64 layers folded accordion-fashion. The presampler, set up inside the cylinder, is an integral part of the calorimeter system: It measures the energy lost by a particle before it reaches the calorimeter. To ensure an ultra-clean environment, a tent (visible here) was erected round the calorimeter and entry point to the cryostat. The detector and presampler, fitted together, could then be slid gradually into the cryostat like a drawer. To do so, the insertion team...

  7. Insertion of the first half-barrel of the ATLAS electromagnetic calorimeter into its cryostat

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    The first cylinder of the ATLAS electromagnetic calorimeter barrel and the presampler have been inserted in the cryostat. The ATLAS electromagnetic calorimeter is intended to detect electrons, positrons and photons by measuring the energy they deposit on being absorbed. The cylinder of the calorimeter is in two halves, that will be sunk in a liquid-argon bath cooled to 90 kelvin (-180°C). Each half-barrel is 3.2 metres long, 53 cm thick and formed by assembling 16 modules. Each module is made up of alternate lead absorbers and electrodes pressed into 64 layers folded accordion-fashion. The presampler, set up inside the cylinder, is an integral part of the calorimeter system: It measures the energy lost by a particle before it reaches the calorimeter. To ensure an ultra-clean environment, a tent was erected round the calorimeter and entry point to the cryostat. The detector and presampler, fitted together, could then be slid gradually into the cryostat like a drawer. To do so, the insertion team had to fine-t...

  8. Installation of the Liquid Argon Calorimater Barrel in the ATLAS Experimental Cavern

    CERN Multimedia

    Vandoni, G.

    On the 27th of October, the Liquid Argon Barrel cryostat was transported from Building 180 to point 1. The next day, the Barrel was lowered into the cavern, and was placed on jacks close to its final position inside the completed lower half of the Tile calorimeter. After a day of precise adjustment, it was resting within a few millimetres of its nominal final position, waiting for the upper half of the Tile calorimeter to be installed. Tight requests had been issued by the Liquid Argon collaboration for the whole transport. It was foreseen that the cryostat should not see any acceleration larger than 0.15g along its axis, 0.08g transversally and 0.3g in the vertical direction. In addition, no acceleration higher than 0.03g (or even 0.003g for permanent oscillation) would be allowed at 20Hz, to avoid the risk of damaging the absorbers at this spontaneous vibration frequency. The difficulty would arise when coping these demands with the tortuous route, its slopes and curbs, vibration transmission from the engi...

  9. The CMS Barrel Calorimeter Response to Particle Beams from 2 to 350 GeV/c

    CERN Document Server

    Abdullin, Salavat; Acharya, Bannaje Sripathi; Adam, Nadia; Adams, Mark Raymond; Adzic, Petar; Akchurin, Nural; Akgun, Ugur; Albayrak, Elif Asli; Alemany-Fernandez, Reyes; Almeida, Nuno; Anagnostou, Georgios; Andelin, Daniel; Anderson, E Walter; Anfreville, Marc; Anicin, Ivan; Antchev, Georgy; Antunovic, Zeljko; Arcidiacono, Roberta; Arenton, Michael Wayne; Auffray, Etiennette; Argiro, Stefano; Askew, Andrew; Atramentov, Oleksiy; Ayan, S; Arcidy, M; Aydin, Sezgin; Aziz, Tariq; Baarmand, Marc M; Babich, Kanstantsin; Baccaro, Stefania; Baden, Drew; Baffioni, Stephanie; Bakirci, Mustafa Numan; Balazs, Michael; Banerjee, Sunanda; Banerjee, Sudeshna; Bard, Robert; Barge, Derek; Barnes, Virgil E; Barney, David; Barone, Luciano; Bartoloni, Alessandro; Baty, Clement; Bawa, Harinder Singh; Baiatian, G; Bandurin, Dmitry; Beauceron, Stephanie; Bell, Ken W; Bencze, Gyorgy; Benetta, Robert; Bercher, Michel; Beri, Suman Bala; Bernet, Colin; Berntzon, Lisa; Berthon, Ursula; Besançon, Marc; Betev, Botjo; Beuselinck, Raymond; Bhatnagar, Vipin; Bhatti, Anwar; Biino, Cristina; Blaha, Jan; Bloch, Philippe; Blyth, Simon; Bodek, Arie; Bornheim, Adolf; Bose, Suvadeep; Bose, Tulika; Bourotte, Jean; Brett, Angela Mary; Brown, Robert M; Britton, David; Budd, Howard; Bühler, M; Burchesky, Kyle; Busson, Philippe; Camanzi, Barbara; Camporesi, Tiziano; Cankocak, Kerem; Carrell, Kenneth Wayne; Carrera, E; Cartiglia, Nicolo; Cavallari, Francesca; Cerci, Salim; Cerutti, cM; Chang, Paoti; Chang, You-Hao; Charlot, Claude; Chen, E Augustine; Chen, Wan-Ting; Chen, Zheng-Yu; Chendvankar, Sanjay; Chipaux, Rémi; Choudhary, Brajesh C; Choudhury, Rajani Kant; Chung, Yeon Sei; Clarida, Warren; Cockerill, David J A; Combaret, Christophe; Conetti, Sergio; Cossutti, Fabio; Cox, Bradley; Cremaldi, Lucien Marcus; Cushman, Priscilla; Cussans, David; Dafinei, Ioan; Damgov, Jordan; Da Silva Di Calafiori, Diogo Raphael; Daskalakis, Georgios; Davatz, Giovanna; David, A; De Barbaro, Pawel; Debbins, Paul; Deiters, Konrad; Dejardin, Marc; Djordjevic, Milos; Deliomeroglu, Mehmet; Della Negra, Rodolphe; Della Ricca, Giuseppe; Del Re, Daniele; Demianov, A; De Min, Alberto; Denegri, Daniel; Depasse, Pierre; de Visser, Theo; Descamps, Julien; Deshpande, Pandurang Vishnu; Díaz, Jonathan; Diemoz, Marcella; Di Marco, Emanuele; Dimitrov, Lubomir; Dissertori, Günther; Dittmar, Michael; Djambazov, Lubomir; Dobrzynski, Ludwik; Drndarevic, Snezana; Duboscq, Jean Etienne; Dugad, Shashikant; Dumanoglu, Isa; Duru, Firdevs; Dutta, Dipanwita; Dzelalija, Mile; Efthymiopoulos, I; Elias, John E; Peisert, A; El-Mamouni, H; Elvira, D; Emeliantchik, Igor; Eno, Sarah Catherine; Ershov, Alexander; Erturk, Sefa; Esen, Selda; Eskut, Eda; Evangelou, Ioannis; Evans, David; Fabbro, Bernard; Faure, Jean-Louis; Fay, Jean; Fenyvesi, Andras; Ferri, Federico; Fisher, Wade Cameron; Flower, Paul S; Franci, Daniele; Franzoni, Giovanni; Freeman, Jim; Freudenreich, Klaus; Funk, Wolfgang; Ganjour, Serguei; Gargiulo, Corrado; Gascon, Susan; Gataullin, Marat; Gaultney, Vanessa; Gamsizkan, Halil; Gavrilov, Vladimir; Geerebaert, Yannick; Genchev, Vladimir; Gentit, François-Xavier; Gerbaudo, Davide; Gershtein, Yuri; Ghezzi, Alessio; Ghodgaonkar, Manohar; Gilly, Jean; Givernaud, Alain; Gleyzer, Sergei V; Gninenko, Sergei; Go, Apollo; Gobbo, Benigno; Godinovic, Nikola; Golubev, Nikolai; Golutvin, Igor; Goncharov, Petr; Gong, Datao; Govoni, Pietro; Grant, Nicholas; Gras, Philippe; Grassi, Tullio; Green, Dan; Greenhalgh, R J S; Gribushin, Andrey; Grinev, B; Guevara Riveros, Luz; Guillaud, Jean-Paul; Gurtu, Atul; Murat Guler, A; Gülmez, Erhan; Gümüs, K; Haelen, T; Hagopian, Sharon; Hagopian, Vasken; Haguenauer, Maurice; Halyo, Valerie; Hamel de Monchenault, Gautier; Hansen, Sten; Hashemi, Majid; Hauptman, John M; Hazen, Eric; Heath, Helen F; Heering, Arjan Hendrix; Heister, Arno; Heltsley, Brian; Hill, Jack; Hintz, Wieland; Hirosky, Robert; Hobson, Peter R; Honma, Alan; Hou, George Wei-Shu; Hsiung, Yee; Hunt, Adam; Husejko, Michal; Ille, Bernard; Ilyina, N; Imlay, Richard; Ingram, D; Ingram, Quentin; Isiksal, Engin; Jarry, Patrick; Jarvis, Chad; Jeong, Chiyoung; Jessop, Colin; Johnson, Kurtis F; Jones, John; Jovanovic, Dragoslav; Kaadze, Ketino; Kachanov, Vassili; Kaftanova, V; Kailas, Swaminathan; Kalagin, Vladimir; Kalinin, Alexey; Kalmani, Suresh Devendrappa; Karmgard, Daniel John; Kataria, Sushil Kumar; Kaur, Manjit; Kaya, Mithat; Kaya, Ozlem; Kayis-Topaksu, A; Kellogg, Richard G; Kennedy, Bruce W; Khmelnikov, Alexander; Kim, Heejong; Kisselevich, I; Kloukinas, Kostas; Kodolova, Olga; Kohli, Jatinder Mohan; Kokkas, Panagiotis; Kolberg, Ted; Kolossov, V; Korablev, Andrey; Korneev, Yury; Kosarev, Ivan; Kramer, Laird; Krasnikov, Nikolai; Krinitsyn, Alexander; Krokhotin, Andrey; Krpic, Dragomir; Kryshkin, V; Kubota, Yuichi; Kubrik, A; Kuleshov, Sergey; Kumar, Arun; Kumar, P; Kunori, Shuichi; Kuo, Chen-Cheng; Kurt, Pelin; Kyberd, Paul; Kyriakis, Aristotelis; Laasanen, Alvin T; Ladygin, Vladimir; Laird, Edward; Landsberg, Greg; Laszlo, Andras; Lawlor, C; Lazic, Dragoslav; Lebeau, Michel; Lecomte, Pierre; Lecoq, Paul; Ledovskoy, Alexander; Lee, Sang Joon; Leshev, Georgi; Lethuillier, Morgan; Levchuk, Leonid; Lin, Sheng-Wen; Lin, Willis; Linn, Stephan; Lintern, A L; Litvine, Vladimir; Litvintsev, Dmitri; Litov, Leander; Lobolo, L; Locci, Elizabeth; Lodge, Anthony B; Longo, Egidio; Loukas, Demetrios; Los, Serguei; Lubinsky, V; Luckey, Paul David; Lukanin, Vladimir; Lustermann, Werner; Lynch, Clare; Ma, Yousi; Machado, Emanuel; Mahlke-Krüger, H; Maity, Manas; Majumder, Gobinda; Malberti, Martina; Malclès, Julie; Maletic, Dimitrije; Mandjavidze, Irakli; Mans, Jeremy; Manthos, Nikolaos; Maravin, Yurii; Marchica, Carmelo; Marinelli, Nancy; Markou, Athanasios; Markou, Christos; Marlow, Daniel; Markowitz, Pete; Marone, Matteo; Martínez, German; Mathez, Hervé; Matveev, Viktor; Mavrommatis, Charalampos; Maurelli, Georges; Mazumdar, Kajari; Meridiani, Paolo; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mescheryakov, G; Mestvirishvili, Alexi; Mikhailin, V; Milenovic, Predrag; Miller, Michael; Milleret, Gérard; Miné, Philippe; Möller, A; Mohammadi-Najafabadi, M; Mohanty, Ajit Kumar; Moissenz, P; Mondal, Naba Kumar; Moortgat, Filip; Mossolov, Vladimir; Mur, Michel; Musella, Pasquale; Musienko, Yuri; Nagaraj, P; Nardulli, Alessandro; Nash, Jordan; Nédélec, Patrick; Negri, Pietro; Newman, Harvey B; Nikitenko, Alexander; Norbeck, Edwin; Nessi-Tedaldi, Francesca; Obertino, Maria Margherita; Olson, Jonathan; Onel, Yasar; Onengüt, G; Organtini, Giovanni; Orimoto, Toyoko; Ozkan, Cigdem; Ozkurt, Halil; Ozkorucuklu, Suat; Ozok, Ferhat; Paganoni, Marco; Paganini, Pascal; Paktinat, S; Pal, Andras; Palma, Alessandro; Panev, Bozhidar; Pant, Lalit Mohan; Papadakis, Antonakis; Papadakis, Ioannis; Papadopoulos, Ioannis; Paramatti, Riccardo; Parracho, P; Pastrone, Nadia; Patil, Mandakini Ravindra; Patterson, Juliet Ritchie; Pauss, Felicitas; Penzo, Aldo; Petrakou, Eleni; Petrushanko, Sergey; Petrosian, A; Phillips II, David; Pikalov, Vladimir; Piperov, Stefan; Piroué, Pierre; Podrasky, V; Polatoz, A; Pompos, Arnold; Popescu, Sorina; Posch, C; Pozdnyakov, Andrey; Ptochos, Fotios; Puljak, Ivica; Pullia, Antonino; Punz, Thomas; Puzovic, Jovan; Qian, Weiming; Ragazzi, Stefano; Rahatlou, Shahram; Ralich, Robert; Rande, J; Razis, Panos A; Redaelli, Nicola; Reddy, L; Reidy, Jim; Renker, Dieter; Reucroft, Steve; Reymond, Jean-Marc; Ribeiro, Pedro Quinaz; Röser, Ulf; Rogalev, Evgueni; Rogan, Christopher; Roh, Youn; Rohlf, James; Romanteau, Thierry; Rondeaux, Françoise; Ronquest, Michael; Ronzhin, Anatoly; Rosowsky, André; Rovelli, Chiara; Ruchti, Randy; Rumerio, Paolo; Rusack, Roger; Rusakov, Sergey V; Ryan, Matthew John; Ryazanov, Anton; Safronov, Grigory; Sala, Leonardo; Salerno, Roberto; Sanders, David A; Santanastasio, Francesco; Sanzeni, Christopher; Sarycheva, Ludmila; Satyanarayana, B; Schinzel, Dietrich; Schmidt, Ianos; Seez, Christopher; Sekmen, Sezen; Semenov, Sergey; Senchishin, V; Sergeyev, S; Serin, Meltem; Sever, Ramazan; Sharp, Peter; Shepherd-Themistocleous, Claire; Siamitros, Christos; Sillou, Daniel; Singh, Jas Bir; Singovsky, Alexander; Sirois, Yves; Sirunyan, Albert M; Silva, J; Silva, Pedro; Skuja, Andris; Sharma, Seema; Sherwood, Brian; Shiu, Jing-Ge; Shivpuri, Ram Krishen; Shukla, Prashant; Shumeiko, Nikolai; Smirnov, Vitaly; Smith, Brian; Smith, Vincent J; Sogut, Kenan; Sonmez, Nasuf; Sorokin, Pavel; Spezziga, Mario; Sproston, Martin; Stefanovich, R; Stockli, F; Stolin, Viatcheslav; Sudhakar, Katta; Sulak, Lawrence; Suter, Henry; Suzuki, Ichiro; Swain, John; Tabarellide Fatis, T; Talov, Vladimir; Takahashi, Maiko; Tcheremoukhine, Alexandre; Teller, Olivier; Teplov, Konstantin; Theofilatos, Konstantinos; Thiebaux, Christophe; Thomas, Ray; Timciuc, Vladlen; Timlin, Claire; Titov, Maksym; Tobias, A; Tonwar, Suresh C; Topakli, Huseyin; Topkar, Anita; Triantis, Frixos A; Troshin, Sergey; Tully, Christopher; Turchanovich, L; Tyurin, Nikolay; Ueno, Koji; Ulyanov, A; Uzunian, Andrey; Vanini, A; Vankov, Ivan; Vardanyan, Irina; Varela, F; Varela, Joao; Vasil ev, A; Velasco, Mayda; Vergili, Mehmet; Verma, Piyush; Verrecchia, Patrice; Vesztergombi, Gyorgy; Veverka, Jan; Vichoudis, Paschalis; Vidal, Richard; Virdee, Tejinder; Vishnevskiy, Alexander; Vlassov, E; Vodopiyanov, Igor; Volobouev, Igor; Volkov, Alexey; Volodko, Anton; Von Gunten, Hans Peter; Wang, Lei; Wang, Minzu; Wardrope, David; Weber, Markus; Weng, Joanna; Werner, Jeremy Scott; Wetstein, Matthew; Winn, Dave; Wigmans, Richard; Williams, Jennifer C; Whitmore, Juliana; Won, Steven; Wu, Shouxiang; Yang, Yong; Yaselli, Ignacio; Yazgan, Efe; Yetkin, Taylan; Yohay, Rachel; Zabi, Alexandre; Zálán, Peter; Zamiatin, Nikolai; Zarubin, Anatoli; Zelepoukine, Serguei; Zeyrek, Mehmet; Zhang, Jia-Wen; Zhang, Lin; Zhu, Kejun; Zhu, Ren-Yuan

    2008-01-01

    The response of the CMS barrel calorimeter (electromagnetic plus hadronic) to hadrons, electrons and muons over a wide momentum range from 2 to 350 GeV/c has been measured. To our knowledge, this is the widest range of momenta in which any calorimeter system has been studied. These tests, carried out at the H2 beam-line at CERN, provide a wealth of information, especially at low energies. The analysis of the differences in calorimeter response to charged pions, kaons, protons and antiprotons and a detailed discussion of the underlying phenomena are presented. We also show techniques that apply corrections to the signals from the considerably different electromagnetic (EB) and hadronic (HB) barrel calorimeters in reconstructing the energies of hadrons. Above 5 GeV/c, these corrections improve the energy resolution of the combined system where the stochastic term equals 84.7$\\pm$1.6$\\%$ and the constant term is 7.4$\\pm$0.8$\\%$. The corrected mean response remains constant within 1.3$\\%$ rms.

  10. Qualification of barrel pixel detector modules for the Phase 1 Upgrade of the CMS vertex detector

    CERN Document Server

    Kudella, Simon

    2016-01-01

    To withstand the higher particle rates of LHC Runs 2 and 3, with expected luminosities of up to $2\\times 10^{34}\\,\\mathrm{cm^{-2}s^{-1}}$, the current CMS pixel detector at the LHC will be replaced as part of the CMS Phase I Upgrade during the extended winter shutdown in 2016/17. The new pixel detector features a new geometry with one additional detector layer in the barrel region~(BPIX) and one pair of additional disks in the forward region~(FPIX), new digital readout chips as well as a new CO$_{2}$-based cooling system for both the barrel and forward region. The BPIX detector module production is summarized, with special focus on the different stages of quality assurance. The quality tests as well as the calibrations which all produced modules undergo in a temperature and humidity controlled environment are described. Exemplarily, the KIT/Aachen production line and its subprocesses are presented together with its quality and yields.

  11. Start of operation of the barrel measuring facility II-01. Implementation into operational processes

    International Nuclear Information System (INIS)

    Buesing, B.; Escher, M.

    2013-01-01

    For the operation of the barrel measuring facility (FAME) II-01 a variety requirements to the measuring techniques were defined and tested in the frame of start-up. The used mechanical engineering and measuring technique complies with the state-of-the-art. Using the barrel measuring facility quality assured determinations of the dose rate and the nuclide-specific activity inventory were performed. For the evaluation of the gamma spectrometric measurements of FAME II-01 appropriately qualified personnel is available. The implementation of the facility in combination with the connection to the data base system PIK-AS and AVK it guaranteed that important data are available in real-time for the measuring process and the subsequent work steps. Besides this it is guaranteed that using the import/export functions relevant data are reviewed, supplemented and exchanged between the systems without transfer errors. The determined data of the dose rate and gamma spectrometric measurements allow an activity determination of the waste package with quality assurance and close to reality. Conservative assumptions in the frame of activity calculations for the later final disposal can be reduced. The automated operation of FAME allows also the reduction of radiation exposure of the personnel.

  12. A case of adenocarcinoma occurred at site of radiated double-barrel sigmoid colostomy

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Hideaki; Kondo, Yukifumi; Takahashi, Masatoshi [Sapporo-Kosei General Hospital (Japan)] [and others

    1996-10-01

    A 60-year-old female developed an adenocarcinoma at the site of double-barrel sigmoid colostomy. She underwent a total hysterectomy and the subsequent radiation therapy due to carcinoma uteri when she was 34 years old. She had rectal stenosis one year later and underwent sigmoid colostomy. She had been healthy thereafter, however, when she was 58 years old, she noticed an elevated lesion at the site of colostomy. Biopsy revealed well-differentiated adenocarcinoma, so surgery was recommended but she refused it. Two years later, the entire stoma became a carcinoma, which directly invaded the abdominal wall on MRI images. A bow-shaped skin incision was made and en bloc resection of the tumor, colostomy and the surrounding tissues was performed. Finally, descending colostomy in the left upper quadrant of the abdomen was reconstructed. Primary adenocarcinoma occurring at a double-barrel colostomy is very rare, and such a case may never have been reported, although there were some reports of carcinoma occurring at an end colostomy. Since the site of the present carcinoma was radiated, the radiation may contribute to this carcinogenesis, suspecting its late effect. Our surgical procedure enabled simultaneously operation of combined resection and intraabdominal manipulation, and the reconstruction site of the stoma was easily selected. (author)

  13. A case of adenocarcinoma occurred at site of radiated double-barrel sigmoid colostomy

    International Nuclear Information System (INIS)

    Ogawa, Hideaki; Kondo, Yukifumi; Takahashi, Masatoshi

    1996-01-01

    A 60-year-old female developed an adenocarcinoma at the site of double-barrel sigmoid colostomy. She underwent a total hysterectomy and the subsequent radiation therapy due to carcinoma uteri when she was 34 years old. She had rectal stenosis one year later and underwent sigmoid colostomy. She had been healthy thereafter, however, when she was 58 years old, she noticed an elevated lesion at the site of colostomy. Biopsy revealed well-differentiated adenocarcinoma, so surgery was recommended but she refused it. Two years later, the entire stoma became a carcinoma, which directly invaded the abdominal wall on MRI images. A bow-shaped skin incision was made and en bloc resection of the tumor, colostomy and the surrounding tissues was performed. Finally, descending colostomy in the left upper quadrant of the abdomen was reconstructed. Primary adenocarcinoma occurring at a double-barrel colostomy is very rare, and such a case may never have been reported, although there were some reports of carcinoma occurring at an end colostomy. Since the site of the present carcinoma was radiated, the radiation may contribute to this carcinogenesis, suspecting its late effect. Our surgical procedure enabled simultaneously operation of combined resection and intraabdominal manipulation, and the reconstruction site of the stoma was easily selected. (author)

  14. Wine consumption habits and consumer preferences between wines aged in barrels or with chips.

    Science.gov (United States)

    Pérez-Magariño, Silvia; Ortega-Heras, Miriam; González-Sanjosé, María Luisa

    2011-03-30

    The use of oak wood pieces in winemaking is increasing, but the acceptance of this technique by consumers is unknown. For that reason, the main aim of this study was to measure consumers' opinion of red wines made with this new technique, their acceptance of them and their intention to purchase these wines. A preference ranking test was also carried out. A specific questionnaire was drawn up for this study and 65 frequent red wine consumers tasted four wines, two aged traditionally in barrels and two macerated with chips, and a forced choice preference test was carried out. Fifty-five per cent of respondents said that they would not buy wines made using oak chips, although most respondents would buy these wines if, after tasting them, they were as pleasant and had the same quality as the wines aged traditionally in barrels. Wines obtained with oak wood fragments were not significantly rejected either by consumers who answered the questionnaire or by consumer tasters, which could be due to the large disparity of preferences found among tasters. The results clearly indicate that producers should develop each wine taking into account the specific preferences of each consumer group. Copyright © 2011 Society of Chemical Industry.

  15. Certification and commissioning of barrel stations for the ATLAS muon spectrometer

    CERN Document Server

    Zimmermann, S

    2006-01-01

    The muon spectrometer of the ATLAS experiment, which is scheduled to commence data taking at the Large Hadron Collider, LHC at CERN in 2007, comprises more than a thousand muon stations, which have the double purpose of triggering on high-p/sub t/ muon tracks as well as providing precise trajectory reconstruction. While monitored drift tube chambers are used for track reconstruction in all of the muon spectrometer except for a region close to the beam pipe in forward direction, two different technologies are used for triggering, resistive plate chambers in the barrel region and thin gap chambers in the end-caps. Both have in common that the ATLAS geometry allows only limited accessibility after chambers are installed in the detector. A thorough testing and certification prior to installation is therefore crucial. This paper reviews the test procedure at CERN for barrel chambers of type BO and BM, i.e. of stations for which a drift chamber is coupled with one or two resistive plate chambers. The final certific...

  16. A time projection chamber for the crystal barrel experiment at ELSA

    Energy Technology Data Exchange (ETDEWEB)

    Schaab, Dimitri; Ball, Markus; Beck, Reinhard; Ketzer, Bernhard [HISKP, Bonn University (Germany); Collaboration: CBELSA/TAPS-Collaboration

    2015-07-01

    The CBELSA/TAPS experiment focuses on baryon spectroscopy by photoproduction processes off nucleons. For this purpose the experiment consists of an inner detector and an outer detector. The outer Crystal Barrel detector mainly measures photons from the decaying resonance. For charged particle identification and in order to obtain their direction, the Inner Detector consists of three layers of scintillating fibers. This inner detector will be replaced by a Time Projection Chamber (TPC). It offers improved track reconstruction capabilities, a robust pattern recognition and, if operated in a magnetic field, an excellent momentum resolution. Moreover, one obtains a particle identification of charged particles via the specific energy loss. A TPC has been developed for the FOPI experiment which also fits to the Crystal Barrel dimensions. It operates in continuous mode using Gas Electron Multipliers (GEM) as pre-amplification stage. For the TPC detector the calibration of the detector is crucial since parameters such as drift velocity or field inhomogenities have a direct impact on the detector performance. For the CBELSA TPC a calibration system is planned, which is based on the T2K calibration system. Here, the photoelectric effect is used to release electrons at well-known positions on the cathode, which drift towards the readout plane and show the integrated spatial distortions.

  17. A New Data Concentrator for the CMS Muon Barrel Track Finder

    CERN Document Server

    Triossi, Andrea

    2014-01-01

    The CMS muon trigger will undergo considerable enhancements in preparation for the LHC \\mbox{run-2}. In order to improve rate reduction and efficiency the full muon trigger chain will be completely redesigned: the plan is to move from a redundant scheme, where the three subdetectors (CSC, DT, RPC) have a separate track finder, to three geographical track finders (barrel, endcap and overlap) that combine trigger primitives of each sub-detector. In particular, the muon barrel track finder (MBTF) will host a new algorithm, that aggregating DT and RPC trigger data, will be able to improve the fake rejection and the muon momentum measurement.This report will focus on the adaptive layer of the MBTF called TwinMux. Its primary role will be to merge, arrange and fan-out the slow optical links from the chambers in faster links (10 Gbps). It will realize a full connectivity matrix between the on-detector electronics and the MBTF allowing for different processing schemes. The TwinMux will be implemented in $\\mu$TCA for...

  18. [«Man-in-the-barrel» syndrome: atypical manifestation of giant cell arteritis].

    Science.gov (United States)

    Calle-Lopez, Y; Fernandez-Ramirez, A F; Franco-Dager, E; Gomez-Lopera, J G; Vanegas-Garcia, A L

    2018-06-01

    «Man-in-the-barrel» syndrome refers to diplegia of the upper extremities in which mobility of the head and lower limbs is preserved. Brachial plexitis that presents as «man-in-the-barrel» syndrome is an unusual manifestation of giant cell arteritis. We report a case of C5-C6 plexitis as part of the clinical features of a patient with giant cell arteritis. A 70-year-old male with a two-month history of weight loss, headache, facial pain and jaw claudication, associated with a persistent elevation of acute phase reactants and bilateral brachial plexopathy, with no evidence of neck or brain injuries or occult neoplasm and with negative autoimmunity tests. Results of the biopsy study of the temporal artery were compatible with giant cell arteritis, and the positron emission tomography scan revealed extensive vascular involvement of the aorta and its branches. Although the typical clinical manifestations of giant cell arteritis are headache, jaw claudication, loss of sight, constitutional symptoms and polymyalgia rheumatica, its presence must be suspected in patients over the age of 50 who manifest alterations affecting the peripheral nerve, including brachial diplegia with no other demonstrable cause.

  19. Design and testing of a coil-unit barrel for helical coil electromagnetic launcher

    Science.gov (United States)

    Yang, Dong; Liu, Zhenxiang; Shu, Ting; Yang, Lijia; Ouyang, Jianming

    2018-01-01

    A coil-unit barrel for a helical coil electromagnetic launcher is described. It provides better features of high structural strength and flexible adjustability. It is convenient to replace the damaged coil units and easy to adjust the number of turns in the stator coils due to the modular design. In our experiments, the highest velocity measured for a 4.5-kg projectile is 47.3 m/s and the mechanical reinforcement of the launcher could bear 35 kA peak current. The relationship between the energy conversion efficiency and the inductance gradient of the launcher is also studied. In the region of low inductance gradient, the efficiency is positively correlated with the inductance gradient. However, in the region of high inductance gradient, the inter-turn arc erosion becomes a major problem of limiting the efficiency and velocity of the launcher. This modular barrel allows further studies in the inter-turn arc and the variable inductance gradient helical coil launcher.

  20. High voltage performance of a dc photoemission electron gun with centrifugal barrel-polished electrodes

    Science.gov (United States)

    Hernandez-Garcia, C.; Bullard, D.; Hannon, F.; Wang, Y.; Poelker, M.

    2017-09-01

    The design and fabrication of electrodes for direct current (dc) high voltage photoemission electron guns can significantly influence their performance, most notably in terms of maximum achievable bias voltage. Proper electrostatic design of the triple-point junction shield electrode minimizes the risk of electrical breakdown (arcing) along the insulator-cable plug interface, while the electrode shape is designed to maintain work, we describe a centrifugal barrel-polishing technique commonly used for polishing the interior surface of superconducting radio frequency cavities but implemented here for the first time to polish electrodes for dc high voltage photoguns. The technique reduced polishing time from weeks to hours while providing surface roughness comparable to that obtained with diamond-paste polishing and with unprecedented consistency between different electrode samples. We present electrode design considerations and high voltage conditioning results to 360 kV (˜11 MV/m), comparing barrel-polished electrode performance to that of diamond-paste polished electrodes. Tests were performed using a dc high voltage photogun with an inverted-geometry ceramic insulator design.

  1. Gamma ray scanner systems for nondestructive assay of heterogeneous waste barrels

    International Nuclear Information System (INIS)

    Martz, H.E.; Decman, B.J.; Roberson, G.P.; Levai, F.

    1997-01-01

    Traditional gamma safeguards measurements have usually been performed using a segmented gamma scanning (SGS) system. The accuracy of this technique relies on the assumption that the sample matrix and the activity are both uniform for a segment. Waste barrels are often highly heterogeneous, span a wide range of composition and matrix type. The primary sources of error are all directly or indirectly related to a non-uniform measurement response associated with unknown radioactive source spatial distribution and heterogeneity of the matrix. These errors can be significantly reduced by some imaging techniques that measure exact spatial locations of sources and attenuation maps. In this paper we describe a joint R ampersand D effort between the Lawrence Livermore National Laboratory (LLNL) and the Institute of Nuclear Techniques (INT) of the Technical University, Budapest, to compare results obtained by two different gamma-ray nondestructive assay (NDA) systems used for imaging waste barrels. The basic principles are the same, but the approaches are different. Key factors to judge the adequacy of a method are the detection limit and the accuracy. Test drums representing waste to be measured are used to determine basic parameters of these techniques

  2. Sam37 is crucial for formation of the mitochondrial TOM-SAM supercomplex, thereby promoting β-barrel biogenesis.

    Science.gov (United States)

    Wenz, Lena-Sophie; Ellenrieder, Lars; Qiu, Jian; Bohnert, Maria; Zufall, Nicole; van der Laan, Martin; Pfanner, Nikolaus; Wiedemann, Nils; Becker, Thomas

    2015-09-28

    Biogenesis of mitochondrial β-barrel proteins requires two preprotein translocases, the general translocase of the outer membrane (TOM) and the sorting and assembly machinery (SAM). TOM and SAM form a supercomplex that promotes transfer of β-barrel precursors. The SAM core complex contains the channel protein Sam50, which cooperates with Sam35 in precursor recognition, and the peripheral membrane protein Sam37. The molecular function of Sam37 has been unknown. We report that Sam37 is crucial for formation of the TOM-SAM supercomplex. Sam37 interacts with the receptor domain of Tom22 on the cytosolic side of the mitochondrial outer membrane and links TOM and SAM complexes. Sam37 thus promotes efficient transfer of β-barrel precursors to the SAM complex. We conclude that Sam37 functions as a coupling factor of the translocase supercomplex of the mitochondrial outer membrane. © 2015 Wenz et al.

  3. Effectiveness of low impact development practices in two urbanized watersheds: retrofitting with rain barrel/cistern and porous pavement.

    Science.gov (United States)

    Ahiablame, Laurent M; Engel, Bernard A; Chaubey, Indrajeet

    2013-04-15

    The impacts of urbanization on hydrology and water quality can be minimized with the use of low impact development (LID) practices in urban areas. This study assessed the performance of rain barrel/cistern and porous pavement as retrofitting technologies in two urbanized watersheds of 70 and 40 km(2) near Indianapolis, Indiana. Six scenarios consisting of the watershed existing condition, 25% and 50% implementation of rain barrel/cistern and porous pavement, and 25% rain barrel/cistern combined with 25% porous pavement were evaluated using a proposed LID modeling framework and the Long-Term Hydrologic Impact Assessment (L-THIA)-LID model. The model was calibrated for annual runoff from 1991 to 2000, and validated from 2001 to 2010 for the two watersheds. For the calibration period, R(2) and NSE values were greater than 0.60 and 0.50 for annual runoff and streamflow. Baseflow was not calibrated in this study. During the validation period, R(2) and NSE values were greater than 0.50 for runoff and streamflow, and 0.30 for baseflow in the two watersheds. The various application levels of barrel/cistern and porous pavement resulted in 2-12% reduction in runoff and pollutant loads for the two watersheds. Baseflow loads slightly increased with increase in baseflow by more than 1%. However, reduction in runoff led to reduction in total streamflow and associated pollutant loads by 1-9% in the watersheds. The results also indicate that the application of 50% rain barrel/cistern, 50% porous pavement and 25% rain barrel/cistern combined with 25% porous pavement are good retrofitting options in these watersheds. The L-THIA-LID model can be used to inform management and decision-making for implementation of LID practices at the watershed scale. Copyright © 2013. Published by Elsevier Ltd.

  4. Development and test of a prototype for the PANDA barrel DIRC detector at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Kalicy, Grzegorz

    2014-07-01

    The PANDA experiment at FAIR will perform world class physics studies using high-intensity cooled antiproton beams with momenta between 1.5 and 15 GeV/c. A rich physics program requires very good particle identification (PID). Charged hadron PID for the barrel section of the target spectrometer has to cover the angular range of 22-140 and separate pions from kaons for momenta up to 3.5 GeV/c with a separation power of at least 3 standard deviations. The system that will provide it has to be thin and operate in a strong magnetic field. A ring imaging Cherenkov detector using the DIRC principle meets those requirements. The design of the PANDA Barrel DIRC is based on the successful BABAR DIRC counter with several important changes to improve the performance and optimize the costs. The design options are being studied in detailed Monte Carlo simulation, and implemented in increasingly complex system prototypes and tested in particle beams. Before building the full system prototypes the radiator bars and lenses are measured on the test benches. The performance of the DIRC prototype was quantified in terms of the single photon Cherenkov angle resolution and the photon yield. Results for two full system prototypes will be presented. The prototype in 2011 aimed at investigating the full size expansion volume. It was found that the resolution for this configuration is at the level of in good agreement with ray tracing simulation results. A more complex prototype, tested in 2012, provided the first experience with a compact fused silica prism expansion volume, a wide radiator plate, and several advanced lens options for the focusing system. The performance of the baseline configuration of the prototype with a standard lens and an air gap met the requirements for the PANDA PID for most of the polar angle range but failed at polar angles around 90 due to photon loss at the air gap. Measurements with a prototype high-refractive index compound lens without an air gap at a polar

  5. Development and test of a prototype for the PANDA barrel DIRC detector at FAIR

    International Nuclear Information System (INIS)

    Kalicy, Grzegorz

    2014-01-01

    The PANDA experiment at FAIR will perform world class physics studies using high-intensity cooled antiproton beams with momenta between 1.5 and 15 GeV/c. A rich physics program requires very good particle identification (PID). Charged hadron PID for the barrel section of the target spectrometer has to cover the angular range of 22-140 and separate pions from kaons for momenta up to 3.5 GeV/c with a separation power of at least 3 standard deviations. The system that will provide it has to be thin and operate in a strong magnetic field. A ring imaging Cherenkov detector using the DIRC principle meets those requirements. The design of the PANDA Barrel DIRC is based on the successful BABAR DIRC counter with several important changes to improve the performance and optimize the costs. The design options are being studied in detailed Monte Carlo simulation, and implemented in increasingly complex system prototypes and tested in particle beams. Before building the full system prototypes the radiator bars and lenses are measured on the test benches. The performance of the DIRC prototype was quantified in terms of the single photon Cherenkov angle resolution and the photon yield. Results for two full system prototypes will be presented. The prototype in 2011 aimed at investigating the full size expansion volume. It was found that the resolution for this configuration is at the level of in good agreement with ray tracing simulation results. A more complex prototype, tested in 2012, provided the first experience with a compact fused silica prism expansion volume, a wide radiator plate, and several advanced lens options for the focusing system. The performance of the baseline configuration of the prototype with a standard lens and an air gap met the requirements for the PANDA PID for most of the polar angle range but failed at polar angles around 90 due to photon loss at the air gap. Measurements with a prototype high-refractive index compound lens without an air gap at a polar

  6. Hadron Energy Reconstruction for ATLAS Barrel Combined Calorimeter Using Non-Parametrical Method

    CERN Document Server

    Kulchitskii, Yu A

    2000-01-01

    Hadron energy reconstruction for the ATLAS barrel prototype combined calorimeter in the framework of the non-parametrical method is discussed. The non-parametrical method utilizes only the known e/h ratios and the electron calibration constants and does not require the determination of any parameters by a minimization technique. Thus, this technique lends itself to fast energy reconstruction in a first level trigger. The reconstructed mean values of the hadron energies are within \\pm1% of the true values and the fractional energy resolution is [(58\\pm 3)%{\\sqrt{GeV}}/\\sqrt{E}+(2.5\\pm0.3)%]\\bigoplus(1.7\\pm0.2) GeV/E. The value of the e/h ratio obtained for the electromagnetic compartment of the combined calorimeter is 1.74\\pm0.04. Results of a study of the longitudinal hadronic shower development are also presented.

  7. Design optimisation of the ATLAS Barrel Toroid structure - the warm structure

    International Nuclear Information System (INIS)

    Daeel, A.; Desvard, J-P.; Pabot, Y.; Sun, Z.; Hille, H. van; Vedrine, P.

    2001-01-01

    The magnetic bending of muon tracks for the ATLAS Muon Spectrometer is provided by the large air-core toroid magnets. The Barrel Toroid structure, named the warm structure, is an open structure inside which the muon chambers are installed. The physics performance of the muon spectrometer imposes stringent requirements on the design of the warm structure. It should support the muon chambers with required precision and stability, the deformation of the structure must be minimised. At the same time, the quantities of the materials used in the structure must also be minimised. Through extensive structural analyses, the design optimisation has been achieved to fit with the physics requirements. This paper gives an overview on the design considerations of the warm structure

  8. Non-compensation of the ATLAS barrel tile hadron module-0 calorimeter

    International Nuclear Information System (INIS)

    Kul'chitskij, Yu.A.; Vinogradov, V.B.

    1999-01-01

    The detailed experimental information about the electron and pion responses, the electron energy resolution and the elh ratio as a function of incident energy E, impact point Z and incidence angle Θ of the Module-0 of the ATLAS iron-scintillator barrel hadron calorimeter with the longitudinal tile configuration is presented. The results are based on the electron and pion beams data for E = 10, 20, 60, 80, 100 and 180 GeV at η = - 0.25 and -0.55, which have been obtained during the test beam period in 1996. The results are compared with the existing experimental data of TILECAL 1m prototype modules, various iron-scintillator calorimeters and with some Monte Carlo calculations

  9. STAR barrel electromagnetic calorimeter absolute calibration using 'minimum ionizing particles' from collisions at RHIC

    International Nuclear Information System (INIS)

    Cormier, T.M.; Pavlinov, A.I.; Rykov, M.V.; Rykov, V.L.; Shestermanov, K.E.

    2002-01-01

    The procedure for the STAR Barrel Electromagnetic Calorimeter (BEMC) absolute calibrations, using penetrating charged particle hits (MIP-hits) from physics events at RHIC, is presented. Its systematic and statistical errors are evaluated. It is shown that, using this technique, the equalization and transfer of the absolute scale from the test beam can be done to a percent level accuracy in a reasonable amount of time for the entire STAR BEMC. MIP-hits would also be an effective tool for continuously monitoring the variations of the BEMC tower's gains, virtually without interference to STAR's main physics program. The method does not rely on simulations for anything other than geometric and some other small corrections, and also for estimations of the systematic errors. It directly transfers measured test beam responses to operations at RHIC

  10. Optimizing Centrifugal Barrel Polishing For Mirror Finish SRF Cavity And RF Tests At Jefferson Lab

    International Nuclear Information System (INIS)

    Palczewski, Ari; Geng, Rongli; Tian, Hui

    2012-01-01

    We performed Centrifugal Barrel Polishing (CBP) on a 1.3 GHz fine grain TESLA single cell cavity and 1.5 GHz fine grain CEBAF high gradient superconducting radio frequency (SRF) single cell cavity following a modified recipe originally developed at Fermi National Accelerator Lab (FNAL). We were able to obtain a mirror like surface similar to that obtained at FNAL, while reducing the number of CBP steps and total processing time. This paper will discuss the change in surface and subsequent cavity performance post CBP, after a 800 C bake (no pre-bake chemistry) and minimal controlled electro-polishing (10 micron). In addition to Q vs. E ACC thermometry mapping with preheating characteristics and optical inspection of the cavity after CBP will also be shown.

  11. Design, Performance, and Calibration of CMS Hadron-Barrel Calorimeter Wedges

    CERN Document Server

    Baiatian, G; Emeliantchik, Igor; Massolov, V; Shumeiko, Nikolai; Stefanovich, R; Damgov, Jordan; Dimitrov, Lubomir; Genchev, Vladimir; Piperov, Stefan; Vankov, Ivan; Litov, Leander; Bencze, Gyorgy; Vesztergombi, Gyorgy; Zálán, Peter; Bawa, Harinder Singh; Beri, Suman Bala; Bhatnagar, Vipin; Kaur, Manjit; Kohli, Jatinder Mohan; Kumar, Arun; Singh, Jas Bir; Acharya, Bannaje Sripathi; Banerjee, Sunanda; Banerjee, Sudeshna; Chendvankar, Sanjay; Dugad, Shashikant; Kalmani, Suresh Devendrappa; Katta, S; Mazumdar, Kajari; Mondal, Naba Kumar; Nagaraj, P; Patil, Mandakini Ravindra; Reddy, L; Satyanarayana, B; Sudhakar, Katta; Verma, Piyush; Paktinat, S; Golutvin, Igor; Kalagin, Vladimir; Kosarev, Ivan; Mescheryakov, G; Sergeyev, S; Smirnov, Vitaly; Volodko, Anton; Zarubin, Anatoli; Gavrilov, Vladimir; Gershtein, Yuri; Kaftanov, Vitali; Kisselevich, I; Kolossov, V; Krokhotin, Andrey; Kuleshov, Sergey; Litvintsev, Dmitri; Stolin, Viatcheslav; Ulyanov, A; Demianov, A; Gribushin, Andrey; Kodolova, Olga; Petrushanko, Sergey; Sarycheva, Ludmila; Vardanyan, Irina; Yershov, A; Abramov, Victor; Goncharov, Petr; Khmelnikov, Alexander; Korablev, Andrey; Korneev, Yury; Krinitsyn, Alexander; Kryshkin, V; Lukanin, Vladimir; Pikalov, Vladimir; Ryazanov, Anton; Talov, Vladimir; Turchanovich, L; Volkov, Alexey; Camporesi, Tiziano; De Visser, Theo; Vlassov, E; Aydin, Sezgin; Dumanoglu, Isa; Eskut, Eda; Kayis-Topaksu, A; Kuzucu-Polatoz, A; Onengüt, G; Ozdes-Koca, N; Cankocak, Kerem; Ozok, Ferhat; Serin-Zeyrek, M; Sever, Ramazan; Zeyrek, Mehmet; Gülmez, Erhan; Isiksal, Engin; Kaya, Mithat; Ozkorucuklu, Suat; Levchuk, Leonid; Sorokin, Pavel; Grinev, B; Lubinsky, V; Senchishin, V; Anderson, E Walter; Hauptman, John M; Elias, John E; Elvira, D; Freeman, Jim; Green, Dan; Lazic, Dragoslav; Los, Serguei; O'Dell, Vivian; Ronzhin, Anatoly; Suzuki, Ichiro; Vidal, Richard; Whitmore, Juliana; Antchev, Georgy; Hazen, Eric; Lawlor, C; Machado, Emanuel; Posch, C; Rohlf, James; Wu, Shouxiang; Adams, Mark Raymond; Burchesky, Kyle; Qiang, W; Abdullin, Salavat; Baden, Drew; Bard, Robert; Eno, Sarah Catherine; Grassi, Tullio; Jarvis, Chad; Kellogg, Richard G; Kunori, Shuichi; Skuja, Andris; Podrasky, V; Sanzeni, Christopher; Winn, Dave; Akgun, Ugur; Ayan, S; Duru, Firdevs; Merlo, Jean-Pierre; Mestvirishvili, Alexi; Miller, Michael; Norbeck, Edwin; Olson, Jonathan; Onel, Yasar; Schmidt, Ianos; Akchurin, Nural; Carrell, Kenneth Wayne; Gumu, K; Thomas, Ray; Baarmand, Marc M; Ralich, Robert; Vodopiyanov, Igor; Cushman, Priscilla; Heering, Arjan Hendrix; Sherwood, Brian; Cremaldi, Lucien Marcus; Reidy, Jim; Sanders, David A; Karmgard, Daniel John; Ruchti, Randy; Fisher, Wade Cameron; Mans, Jeremy; Tully, Christopher; De Barbaro, Pawel; Bodek, Arie; Budd, Howard; Chung, Yeon Sei; Haelen, T; Imboden, Matthias; Hagopian, Sharon; Hagopian, Vasken; Johnson, Kurtis F; Barnes, Virgil E; Laasanen, Alvin T; Pompos, Arnold

    2007-01-01

    Extensive measurements have been made with pions, electrons and muons on four production wedges of the Compact Muon Solenoid (CMS) hadron barrel (HB) calorimeter in the H2 beam line at CERN with particle momenta varying from 20 to 300 GeV/c. Data were taken both with and without a prototype electromagnetic lead tungstate crystal calorimeter (EB) in front of the hadron calorimeter. The time structure of the events was measured with the full chain of preproduction front-end electronics running at 34 MHz. Moving-wire radioactive source data were also collected for all scintillator layers in the HB. These measurements set the absolute calibration of the HB prior to first pp collisions to approximately 4%.

  12. High performance interactive graphics for shower reconstruction in HPC, the DELPHI barrel electromagnetic calorimeter

    International Nuclear Information System (INIS)

    Stanescu, C.

    1990-01-01

    Complex software for shower reconstruction in DELPHI barrel electromagnetic calorimeter which deals, for each event, with great amounts of information, due to the high spatial resolution of this detector, needs powerful verification tools. An interactive graphics program, running on high performance graphics display system Whizzard 7555 from Megatek, was developed to display the logical steps in showers and their axes reconstruction. The program allows both operations on the image in real-time (rotation, translation and zoom) and the use of non-geometrical criteria to modify it (as the use of energy) thresholds for the representation of the elements that compound the showers (or of the associated lego plots). For this purpose graphics objects associated to user parameters were defined. Instancing and modelling features of the native graphics library were extensively used

  13. Application of linear accelerator technology to the detection of trace amounts of transuranics in waste barrels

    International Nuclear Information System (INIS)

    Cates, M.R.; Noel, B.W.; Caldwell, J.T.; Kunz, W.E.; Close, D.A.; Franks, L.A.; Pigg, J.L.

    1980-01-01

    Electron linear accelerators (linacs), as sources of photons and neutrons, can produce a significant number of fissions in transuranic isotopes contained in large barrels of waste material. Both photons and thermal neutrons have been used to detect about 1 mg of plutonium in 105-kg matrices. A sequential interrogation with neutrons and photons, easily possible with linacs, can show both fertile and fissile constituents among the heavy-mass isotopes. The advantages of linacs in solving existing assay problems include: (1) high available beam current; (2) variable beam current, beam energy, pulse width, and pulse repetition frequency; and (3) beam-scanning ability. They also are compatible with passive assay instruments. Their versatility makes it likely that they will remain useful as assay technology advances

  14. Geometrical principles of homomeric β-barrels and β-helices: Application to modeling amyloid protofilaments.

    Science.gov (United States)

    Hayward, Steven; Milner-White, E James

    2017-10-01

    Examples of homomeric β-helices and β-barrels have recently emerged. Here we generalize the theory for the shear number in β-barrels to encompass β-helices and homomeric structures. We introduce the concept of the "β-strip," the set of parallel or antiparallel neighboring strands, from which the whole helix can be generated giving it n-fold rotational symmetry. In this context, the shear number is interpreted as the sum around the helix of the fixed register shift between neighboring identical β-strips. Using this approach, we have derived relationships between helical width, pitch, angle between strand direction and helical axis, mass per length, register shift, and number of strands. The validity and unifying power of the method is demonstrated with known structures including α-hemolysin, T4 phage spike, cylindrin, and the HET-s(218-289) prion. From reported dimensions measured by X-ray fiber diffraction on amyloid fibrils, the relationships can be used to predict the register shift and the number of strands within amyloid protofilaments. This was used to construct models of transthyretin and Alzheimer β(40) amyloid protofilaments that comprise a single strip of in-register β-strands folded into a "β-strip helix." Results suggest both stabilization of an individual β-strip helix and growth by addition of further β-strip helices can involve the same pair of sequence segments associating with β-sheet hydrogen bonding at the same register shift. This process would be aided by a repeat sequence. Hence, understanding how the register shift (as the distance between repeat sequences) relates to helical dimensions will be useful for nanotube design. © 2017 Wiley Periodicals, Inc.

  15. Insights into the fold organization of TIM barrel from interaction energy based structure networks.

    Science.gov (United States)

    Vijayabaskar, M S; Vishveshwara, Saraswathi

    2012-01-01

    There are many well-known examples of proteins with low sequence similarity, adopting the same structural fold. This aspect of sequence-structure relationship has been extensively studied both experimentally and theoretically, however with limited success. Most of the studies consider remote homology or "sequence conservation" as the basis for their understanding. Recently "interaction energy" based network formalism (Protein Energy Networks (PENs)) was developed to understand the determinants of protein structures. In this paper we have used these PENs to investigate the common non-covalent interactions and their collective features which stabilize the TIM barrel fold. We have also developed a method of aligning PENs in order to understand the spatial conservation of interactions in the fold. We have identified key common interactions responsible for the conservation of the TIM fold, despite high sequence dissimilarity. For instance, the central beta barrel of the TIM fold is stabilized by long-range high energy electrostatic interactions and low-energy contiguous vdW interactions in certain families. The other interfaces like the helix-sheet or the helix-helix seem to be devoid of any high energy conserved interactions. Conserved interactions in the loop regions around the catalytic site of the TIM fold have also been identified, pointing out their significance in both structural and functional evolution. Based on these investigations, we have developed a novel network based phylogenetic analysis for remote homologues, which can perform better than sequence based phylogeny. Such an analysis is more meaningful from both structural and functional evolutionary perspective. We believe that the information obtained through the "interaction conservation" viewpoint and the subsequently developed method of structure network alignment, can shed new light in the fields of fold organization and de novo computational protein design.

  16. Usage of FT-ICR-MS Metabolomics for characterizing the chemical signatures of barrel-aged whisky

    Science.gov (United States)

    Roullier-Gall, Chloé; Signoret, Julie; Hemmler, Daniel; Witting, Michael A.; Kanawati, Basem; Schäfer, Bernhard; Gougeon, Régis D.; Schmitt-Kopplin, Philippe

    2018-02-01

    Whisky can be described as a complex matrix integrating the chemical history from the fermented cereals, the wooden barrels, the specific distillery processes, ageing and environmental factors. In this study, using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS), we analysed 150 whisky samples from 49 different distilleries, 7 countries, and ranging from 1 day new make spirit to 43 years of maturation with different types of barrel. Chemometrics revealed the unexpected impact of the wood history on the distillatés composition during barrel ageing, regardless of the whisky origin. Flavonols, oligolignols and fatty acids are examples of important chemical signatures for Bourbon casks, whereas a high number of polyphenol glycosides, including for instance quercetin-glucuronide or myricetin-glucoside as potential candidates, and carbohydrates would discriminate Sherry casks. However, the comparison of barrel aged rums and whiskies revealed specific signatures, highlighting the importance of the initial composition of the distillate and the distillery processes.

  17. A cosmic ray muon recorded by the ATLAS barrel tile calorimeter at 18:30, on 21 June 2005.

    CERN Multimedia

    2005-01-01

    The ATLAS barrel tile calorimeter has recorded its first events underground using a cosmic ray trigger, as part of the detector commissioning programme. The calorimeter has three layers and a pointing geometry. The light trapezoids represent the energy deposited in the tiles of the calorimeter depicted as a thick disk.

  18. Lock, Stock and Two Different Barrels: Comparing the Genetic Composition of Morphotypes of the Indo-Pacific Sponge

    NARCIS (Netherlands)

    Swierts, T.; Peijnenburg, K.T.C.A.; de Leeuw, C.; Cleary, D.F.R.; Hörnlein, C.; Setiawan, E.; Wörheide, G.; Erpenbeck, D.; de Voogd, N.J.

    2013-01-01

    The giant barrel sponge Xestospongia testudinaria is an ecologically important species that is widely distributed across the Indo-Pacific. Little is known, however, about the precise biogeographic distribution and the amount of morphological and genetic variation in this species. Here we provide the

  19. Lock, stock and two different barrels: comparing the genetic composition of morphotypes of the Indo-Pacific sponge Xestospongia testudinaria

    NARCIS (Netherlands)

    Swierts, T.; Peijnenburg, K.T.C.A.; Leeuw, de C.; Cleary, D.F.R.; Hörnlein, C.; Setiawan, E.; Wörheide, G.; Erpenbeck, D.; Voogd, de N.J.

    2013-01-01

    The giant barrel sponge Xestospongia testudinaria is an ecologically important species that is widely distributed across the Indo-Pacific. Little is known, however, about the precise biogeographic distribution and the amount of morphological and genetic variation in this species. Here we provide the

  20. Lock, Stock and two different barrels: comparing the genetic composition of morphotypes of the Indo-Pacific sponge Xestospongia testudinaria

    NARCIS (Netherlands)

    Swierts, T.; Peijnenburg, K.; de Leeuw, C.; Cleary, D.F.R.; Hörnlein, C.; Setiawan, E.; Wörheide, G.; Erpenbeck, D.; de Voogd, N.J.

    2013-01-01

    The giant barrel sponge Xestospongia testudinaria is an ecologically important species that is widely distributed across the Indo-Pacific. Little is known, however, about the precise biogeographic distribution and the amount of morphological and genetic variation in this species. Here we provide the