Egr3 dependent sympathetic target tissue innervation in the absence of neuron death.

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Lin Li

Full Text Available Nerve Growth Factor (NGF is a target tissue derived neurotrophin required for normal sympathetic neuron survival and target tissue innervation. NGF signaling regulates gene expression in sympathetic neurons, which in turn mediates critical aspects of neuron survival, axon extension and terminal axon branching during sympathetic nervous system (SNS development. Egr3 is a transcription factor regulated by NGF signaling in sympathetic neurons that is essential for normal SNS development. Germline Egr3-deficient mice have physiologic dysautonomia characterized by apoptotic sympathetic neuron death and abnormal innervation to many target tissues. The extent to which sympathetic innervation abnormalities in the absence of Egr3 is caused by altered innervation or by neuron death during development is unknown. Using Bax-deficient mice to abrogate apoptotic sympathetic neuron death in vivo, we show that Egr3 has an essential role in target tissue innervation in the absence of neuron death. Sympathetic target tissue innervation is abnormal in many target tissues in the absence of neuron death, and like NGF, Egr3 also appears to effect target tissue innervation heterogeneously. In some tissues, such as heart, spleen, bowel, kidney, pineal gland and the eye, Egr3 is essential for normal innervation, whereas in other tissues such as lung, stomach, pancreas and liver, Egr3 appears to have little role in innervation. Moreover, in salivary glands and heart, two tissues where Egr3 has an essential role in sympathetic innervation, NGF and NT-3 are expressed normally in the absence of Egr3 indicating that abnormal target tissue innervation is not due to deregulation of these neurotrophins in target tissues. Taken together, these results clearly demonstrate a role for Egr3 in mediating sympathetic target tissue innervation that is independent of neuron survival or neurotrophin deregulation.

Anatomy of psoas muscle innervation: Cadaveric study.

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Mahan, Mark A; Sanders, Luke E; Guan, Jian; Dailey, Andrew T; Taylor, William; Morton, David A

2017-05-01

Hip flexion weakness is relatively common after lateral transpsoas surgery. Persistent weakness may result from injury to the innervation of the psoas major muscles (PMMs); however, anatomical texts have conflicting descriptions of this innervation, and the branching pattern of the nerves within the psoas major, particularly relative to vertebral anatomy, has not been described. The authors dissected human cadavers to describe the branching pattern of nerves supplying the PMMs. Sixteen embalmed cadavers were dissected, and the fine branching pattern of the innervation to the PMM was studied in 24 specimens. The number of branches and width and length of each branch of nerves to the PMMs were quantified. Nerve branches innervating the PMMs arose from spinal nerve levels L1-L4, with an average of 6.3 ± 1.1 branches per muscle. The L1 nerve branch was the least consistently present, whereas L2 and L3 branches were the most robust, the most numerous, and always present. The nerve branches to the psoas major commonly crossed the intervertebral (IV) disc obliquely prior to ramification within the muscle; 76%, 80%, and 40% of specimens had a branch to the PMM cross the midportion of the L2-3, L3-4, and L4-5 IV discs, respectively. The PMMs are segmentally innervated from the L2-L4 ventral rami branches, where these branches course obliquely across the L2-3, L3-4, and L4-5 IV discs. Knowledge of the mapping of nerve branches to the PMMs may reduce injury and the incidence of persistent weak hip flexion during lateral transpsoas surgery. Clin. Anat. 30:479-486, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Catecholamine innervation of the caudal spinal cord in the rat

DEFF Research Database (Denmark)

Schrøder, H D; Skagerberg, G

1985-01-01

matter were found to contain catecholamines. In the dorsal horn the most intense fluorescence was seen in the superficial layers. The motoneuron neuropil exhibited the most prominent catecholamine-fluorescence of the ventral horn layers. In the sixth lumbar segment, which contains the motor nuclei....... In the intermediate gray the intermediolateral nucleus in thoracic and upper lumbar segments was the most heavily innervated area, followed by the medial lumbar sympathetic group, which contains the majority of the sympathetic preganglionic neurons innervating the pelvic organs. The parasympathetic intermediolateral...... nucleus in the upper sacral segments received a catecholamine innervation of moderate density. The catecholamine innervation pattern is discussed in relation to the patterns of other putative transmitters. The distribution of catecholamine fluorescence in relation to nuclei that control the pelvic organs...

Noradrenergic and cholinergic innervation of the bone marrow.

Science.gov (United States)

Artico, Marco; Bosco, Sandro; Cavallotti, Carlo; Agostinelli, Enzo; Giuliani-Piccari, Gabriella; Sciorio, Salvatore; Cocco, Lucio; Vitale, Marco

2002-07-01

Bone marrow is supplied by sensory and autonomic innervation. Although it is well established that hematopoiesis is regulated by cytokines and cell-to-cell contacts, the role played by neuromediators on the proliferation, differentiation and release of hematopoietic cells is still controversial. We studied the innervation of rat femur bone marrow by means of fluorescence histochemistry and immunohistochemistry. Glyoxylic acid-induced fluorescence was used to demonstrate catecholaminergic nerve fibers. The immunoperoxidase method with nickel amplification was applied to detect the distribution of nerve fibers using antibodies against the general neuronal marker PGP 9.5 (neuron-specific cytoplasmic protein), while the cholinacetyltransferase immunoreactivity was studied by immunohistochemistry. Our results show the presence of an extensive network of innervation in the rat bone marrow, providing a morphological basis for the neural modulation of hemopoiesis.

Innervation of the mammalian esophagus.

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Neuhuber, Winfried L; Raab, Marion; Berthoud, Hans-Rudolf; Wörl, Jürgen

2006-01-01

Understanding the innervation of the esophagus is a prerequisite for successful treatment of a variety of disorders, e.g., dysphagia, achalasia, gastroesophageal reflux disease (GERD) and non-cardiac chest pain. Although, at first glance, functions of the esophagus are relatively simple, their neuronal control is considerably complex. Vagal motor neurons of the nucleus ambiguus and preganglionic neurons of the dorsal motor nucleus innervate striated and smooth muscle, respectively. Myenteric neurons represent the interface between the dorsal motor nucleus and smooth muscle but they are also involved in striated muscle innervation. Intraganglionic laminar endings (IGLEs) represent mechanosensory vagal afferent terminals. They also establish intricate connections with enteric neurons. Afferent information is implemented by the swallowing central pattern generator in the brainstem, which generates and coordinates deglutitive activity in both striated and smooth esophageal muscle and orchestrates esophageal sphincters as well as gastric adaptive relaxation. Disturbed excitation/inhibition balance in the lower esophageal sphincter results in motility disorders, e.g., achalasia and GERD. Loss of mechanosensory afferents disrupts adaptation of deglutitive motor programs to bolus variables, eventually leading to megaesophagus. Both spinal and vagal afferents appear to contribute to painful sensations, e.g., non-cardiac chest pain. Extrinsic and intrinsic neurons may be involved in intramural reflexes using acetylcholine, nitric oxide, substance P, CGRP and glutamate as main transmitters. In addition, other molecules, e.g., ATP, GABA and probably also inflammatory cytokines, may modulate these neuronal functions.

Flow around a cylinder surrounded by a permeable cylinder in shallow water

Energy Technology Data Exchange (ETDEWEB)

Ozkan, Gokturk M.; Akilli, Huseyin; Sahin, Besir [Cukurova University, Department of Mechanical Engineering, Faculty of Engineering and Architecture, Adana (Turkey); Oruc, Vedat [Dicle University, Department of Mechanical Engineering, Diyarbakir (Turkey)

2012-12-15

The change in flow characteristics downstream of a circular cylinder (inner cylinder) surrounded by an outer permeable cylinder was investigated in shallow water using particle image velocimetry technique. The diameter of the inner cylinder and the water height were kept constant during the experiments as d=50 mm and h{sub w}=25 mm, respectively. The depth-averaged free-stream velocity was also kept constant as U=170 mm/s which corresponded to a Reynolds number of Re{sub d}=8,500 based on the inner cylinder diameter. In order to examine the effect of diameter and porosity of the outer cylinder on flow characteristics of the inner cylinder, five different outer cylinder diameters (D=60, 70, 80, 90 and 100 mm) and four different porosities ({beta}=0.4, 0.5, 0.6 and 0.7) were used. It was shown that both porosity and outer cylinder diameter had a substantial effect on the flow characteristics downstream of the circular cylinder. Turbulent statistics clearly demonstrated that in comparison with the bare cylinder (natural case), turbulent kinetic energy and Reynolds stresses decreased remarkably when an outer cylinder was placed around the inner cylinder. Thereby, the interaction of shear layers of the inner cylinder has been successfully prevented by the presence of outer cylinder. It was suggested by referring to the results that the outer cylinder having 1.6{<=}D/d{<=}2.0 and 0.4{<=}D/d{<=}0.6 should be preferred to have a better flow control in the near wake since the peak magnitude of turbulent kinetic energy was considerably low in comparison with the natural case and it was nearly constant for these mentioned porosities {beta}, and outer cylinder to inner cylinder diameter ratios D/d. (orig.)

Discrete innervation of murine taste buds by peripheral taste neurons.

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Zaidi, Faisal N; Whitehead, Mark C

2006-08-09

The peripheral taste system likely maintains a specific relationship between ganglion cells that signal a particular taste quality and taste bud cells responsive to that quality. We have explored a measure of the receptoneural relationship in the mouse. By injecting single fungiform taste buds with lipophilic retrograde neuroanatomical markers, the number of labeled geniculate ganglion cells innervating single buds on the tongue were identified. We found that three to five ganglion cells innervate a single bud. Injecting neighboring buds with different color markers showed that the buds are primarily innervated by separate populations of geniculate cells (i.e., multiply labeled ganglion cells are rare). In other words, each taste bud is innervated by a population of neurons that only connects with that bud. Palate bud injections revealed a similar, relatively exclusive receptoneural relationship. Injecting buds in different regions of the tongue did not reveal a topographic representation of buds in the geniculate ganglion, despite a stereotyped patterned arrangement of fungiform buds as rows and columns on the tongue. However, ganglion cells innervating the tongue and palate were differentially concentrated in lateral and rostral regions of the ganglion, respectively. The principal finding that small groups of ganglion cells send sensory fibers that converge selectively on a single bud is a new-found measure of specific matching between the two principal cellular elements of the mouse peripheral taste system. Repetition of the experiments in the hamster showed a more divergent innervation of buds in this species. The results indicate that whatever taste quality is signaled by a murine geniculate ganglion neuron, that signal reflects the activity of cells in a single taste bud.

Successful Implantation of Bioengineered, Intrinsically Innervated, Human Internal Anal Sphincter

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Raghavan, Shreya; Gilmont, Robert R.; Miyasaka, Eiichi A.; Somara, Sita; Srinivasan, Shanthi; Teitelbaum, Daniel H; Bitar, Khalil N.

2011-01-01

Background & Aims To restore fecal continence, the weakened pressure of the internal anal sphincter (IAS) must be increased. We bioengineered intrinsically innervated human IAS, to emulate sphincteric physiology, in vitro. Methods We co-cultured human IAS circular smooth muscle with immortomouse fetal enteric neurons. We investigated the ability of bioengineered innervated human IAS, implanted in RAG1−/− mice, to undergo neovascularization and preserve the physiology of the constituent myogenic and neuronal components. Results The implanted IAS was neovascularized in vivo; numerous blood vessels were observed with no signs of inflammation or infection. Real-time force acquisition from implanted and pre-implant IAS showed distinct characteristics of IAS physiology. Features included the development of spontaneous myogenic basal tone; relaxation of 100% of basal tone in response to inhibitory neurotransmitter vasoactive intestinal peptide (VIP) and direct electrical field stimulation of the intrinsic innervation; inhibition of nitrergic and VIPergic EFS-induced relaxation (by antagonizing nitric oxide synthesis or receptor interaction); contraction in response to cholinergic stimulation with acetylcholine; and intact electromechanical coupling (evidenced by direct response to potassium chloride). Implanted, intrinsically innervated bioengineered human IAS tissue preserved the integrity and physiology of myogenic and neuronal components. Conclusion Intrinsically innervated human IAS bioengineered tissue can be successfully implanted in mice. This approach might be used to treat patients with fecal incontinence. PMID:21463628

Autonomic innervation of the heart. Role of molecular imaging

Energy Technology Data Exchange (ETDEWEB)

Slart, Riemer H.J.A; Elsinga, Philip H. [Univ. Medical Center Groningen (Netherlands). Nuclear Medicine and Molecular Imaging; Tio, Rene A. [Univ. Medical Center Groningen (Netherlands). Thorax Center Cardiology; Schwaiger, Markus (ed.) [Technische Univ. Muenchen Klinikum Rechts der Isar (Germany). Nuklearmedizinische Klinik

2015-03-01

Reviews in detail the value of SPECT-CT and PET-CT in the imaging of cardiac innervation. Details the role of imaging in a range of conditions and diseases. Includes important background on pathophysiology, tracers, radiopharmaceutical production, and kinetic modeling software. This book explains in detail the potential value of the hybrid modalities, SPECT-CT and PET-CT, in the imaging of cardiac innervation in a wide range of conditions and diseases, including ischemic heart disease, diabetes mellitus, heart failure, amyloidosis, heart transplantation, and ventricular arrhythmias. Imaging of the brain-heart axis in neurodegenerative disease and stress and of cardiotoxicity is also discussed. The roles of the various available tracers are fully considered, and individual chapters address radiopharmaceutical development under GMP, imaging physics, and kinetic modeling software. Highly relevant background information is included on the autonomic nervous system of the heart and its pathophysiology, and in addition future perspectives are discussed. Awareness of the importance of autonomic innervation of the heart for the optimal management of cardiac patients is growing, and there is an evident need for objective measurement techniques or imaging modalities. In this context, Autonomic Innervation of the Heart will be of wide interest to clinicians, researchers, and industry.

Autonomic innervation of the heart. Role of molecular imaging

International Nuclear Information System (INIS)

Slart, Riemer H.J.A; Elsinga, Philip H.; Tio, Rene A.; Schwaiger, Markus

2015-01-01

Reviews in detail the value of SPECT-CT and PET-CT in the imaging of cardiac innervation. Details the role of imaging in a range of conditions and diseases. Includes important background on pathophysiology, tracers, radiopharmaceutical production, and kinetic modeling software. This book explains in detail the potential value of the hybrid modalities, SPECT-CT and PET-CT, in the imaging of cardiac innervation in a wide range of conditions and diseases, including ischemic heart disease, diabetes mellitus, heart failure, amyloidosis, heart transplantation, and ventricular arrhythmias. Imaging of the brain-heart axis in neurodegenerative disease and stress and of cardiotoxicity is also discussed. The roles of the various available tracers are fully considered, and individual chapters address radiopharmaceutical development under GMP, imaging physics, and kinetic modeling software. Highly relevant background information is included on the autonomic nervous system of the heart and its pathophysiology, and in addition future perspectives are discussed. Awareness of the importance of autonomic innervation of the heart for the optimal management of cardiac patients is growing, and there is an evident need for objective measurement techniques or imaging modalities. In this context, Autonomic Innervation of the Heart will be of wide interest to clinicians, researchers, and industry.

Cylinder monitoring program

Energy Technology Data Exchange (ETDEWEB)

Alderson, J.H. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

1991-12-31

Cylinders containing depleted uranium hexafluoride (UF{sub 6}) in storage at the Department of Energy (DOE) gaseous diffusion plants, managed by Martin Marietta Energy Systems, Inc., are being evaluated to determine their expected storage life. Cylinders evaluated recently have been in storage service for 30 to 40 years. In the present environment, the remaining life for these storage cylinders is estimated to be 30 years or greater. The group of cylinders involved in recent tests will continue to be monitored on a periodic basis, and other storage cylinders will be observed as on a statistical sample population. The program has been extended to all types of large capacity UF{sub 6} cylinders.

Intrinsic and extrinsic innervation of the heart in zebrafish (Danio rerio).

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Stoyek, Matthew R; Croll, Roger P; Smith, Frank M

2015-08-01

In the vertebrate heart the intracardiac nervous system is the final common pathway for autonomic control of cardiac output, but the neuroanatomy of this system is not well understood. In this study we investigated the innervation of the heart in a model vertebrate, the zebrafish. We used antibodies against acetylated tubulin, human neuronal protein C/D, choline acetyltransferase, tyrosine hydroxylase, neuronal nitric oxide synthase, and vasoactive intestinal polypeptide to visualize neural elements and their neurotransmitter content. Most neurons were located at the venous pole in a plexus around the sinoatrial valve; mean total number of cells was 197 ± 23, and 92% were choline acetyltransferase positive, implying a cholinergic role. The plexus contained cholinergic, adrenergic, and nitrergic axons and vasoactive intestinal polypeptide-positive terminals, some innervating somata. Putative pacemaker cells near the plexus showed immunoreactivity for hyperpolarization-activated cyclic nucleotide-gated channel 4 (HCN4) and the transcription factor Islet-1 (Isl1). The neurotracer neurobiotin showed that extrinsic axons from the left and right vagosympathetic trunks innervated the sinoatrial plexus proximal to their entry into the heart; some extrinsic axons from each trunk also projected into the medial dorsal plexus region. Extrinsic axons also innervated the atrial and ventricular walls. An extracardiac nerve trunk innervated the bulbus arteriosus and entered the arterial pole of the heart to innervate the proximal ventricle. We have shown that the intracardiac nervous system in the zebrafish is anatomically and neurochemically complex, providing a substrate for autonomic control of cardiac effectors in all chambers. © 2015 Wiley Periodicals, Inc.

Anatomic Patterns of Renal Arterial Sympathetic Innervation: New Aspects for Renal Denervation.

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Imnadze, Guram; Balzer, Stefan; Meyer, Baerbel; Neumann, Joerg; Krech, Rainer Horst; Thale, Joachim; Franz, Norbert; Warnecke, Henning; Awad, Khaled; Hayek, Salim S; Devireddy, Chandan

2016-12-01

Initial studies of catheter-based renal arterial sympathetic denervation to lower blood pressure in resistant hypertensive patients renewed interest in the sympathetic nervous system's role in the pathogenesis of hypertension. However, the SYMPLICITY HTN-3 study failed to meet its prespecified blood pressure lowering efficacy endpoint. To date, only a limited number of studies have described the microanatomy of renal nerves, of which, only two involve humans. Renal arteries were harvested from 15 cadavers from the Klinikum Osnabruck and Schuchtermann Klinik, Bad Rothenfelde. Each artery was divided longitudinally in equal thirds (proximal, middle, and distal), with each section then divided into equal superior, inferior, anterior, and posterior quadrants, which were then stained. Segments containing no renal nerves were given a score value = 0, 1-2 nerves with diameter 4 nerves or nerve diameter ≥600 µm a score = 3. A total of 22 renal arteries (9 right-sided, 13 left-sided) were suitable for examination. Overall, 691 sections of 5 mm thickness were prepared. Right renal arteries had significantly higher mean innervation grade (1.56 ± 0.85) compared to left renal arteries (1.09 ± 0.87) (P renal artery has significantly higher innervation scores than the left. The anterior and superior quadrants of the renal arteries scored higher in innervation than the posterior and inferior quadrants did. The distal third of the renal arteries are more innervated than the more proximal segments. These findings warrant further evaluation of the spatial innervation patterns of the renal artery in order to understand how it may enhance catheter-based renal arterial denervation procedural strategy and outcomes. The SYMPLICITY HTN-3 study dealt a blow to the idea of the catheter-based renal arterial sympathetic denervation. We investigated the location and patterns of periarterial renal nerves in cadaveric human renal arteries. To quantify the density of the

Catecholaminergic and serotoninergic fibres innervate the ventricular system of the hedgehog CNS.

Science.gov (United States)

Michaloudi, H C; Papadopoulos, G C

1996-01-01

Immunocytochemistry with antisera against serotonin (5-HT), dopamine (DA) and noradrenaline (NA) was used to detect monoaminergic (MA) fibres in the ventricular system of the hedgehog Erinaceus europaeus. Light microscopic examination of immunocytochemically stained sections revealed that the ventricular system of the hedgehog is unique among mammals in that the choroid plexuses receive CA axons and that the supraependyma and subependyma of the cerebral ventricles and the spinal central canal are innervated both by serotoninergic and catecholaminergic (CA) fibres. Supraependymal 5-HT axons were generally more abundant and created at places a large number of interconnected basket-like structures, whereas CA fibres were usually directed towards the ventricular lumen. In the lateral ventricles, CA fibres were more numerous in the ependyma lining grey matter, whereas a higher 5-HT innervation density was observed in the area between the corpus callosum and the caudate nucleus or the septum. In the 3rd ventricle, the ependyma of its dorsal part exhibited a higher 5-HT and NA innervation density, whereas DA fibres were preferentially distributed in the ventral half of the basal region. The ependyma lining the cerebral aqueduct displayed a higher MA innervation density in its ventral part. The ependymal wall of the 4th ventricle exhibited an extremely dense 5-HT innervation, mainly in the floor of the ventricle, relatively fewer NA fibres and only sparse DA ones. Few NA and relatively more 5-HT fibres were detected in the ependyma of the central canal. Finally, the circumventricular organs were unevenly innervated by the 3 types of MA fibres. The extensive monoaminergic innervation of the hedgehog ventricular system described here probably reflects a transitory evolutionary stage in the phylogeny of the MA systems with presently unknown functional implications. Images Fig. 1 Fig. 2 Figs 3-8 Figs 9-14 Figs 15-20 PMID:8886949

Adrenergic innervation of the rat hypothalamus

NARCIS (Netherlands)

Palkovits, M.; Mezey, E.; Záborszky, L.; Feminger, A.; Versteeg, D.H.G.; Wijnen, H.J.L.M.; Jong, Wybren de; Fekete, M.I.K.; Herman, J.P.; Kanyicska, B.

The adrenergic innervation of the hypothalamus was studied by measuring hypothalamic adrenaline levels following surgical transection of the lower brain stem or electrolytic lesion of the medullary adrenaline-containing cell groups. The adrenaline levels in some hypothalamic nuclei and in the median

Innervation of the sheep pineal gland by nonsympathetic nerve fibers containing NADPH-diaphorase activity

DEFF Research Database (Denmark)

López-Figueroa, Manuel O.; Ravault, Jean-Paul; Cozzi, Bruno

1997-01-01

Neuroanatomy, NADPH-diaphorase, nitric oxide, innervation, superior cervical ganglionectomy, neuropeptide Y.......Neuroanatomy, NADPH-diaphorase, nitric oxide, innervation, superior cervical ganglionectomy, neuropeptide Y....

Peripheral innervation patterns of vestibular nerve afferents in the bullfrog utriculus

Science.gov (United States)

Baird, Richard A.; Schuff, N. R.

1994-01-01

Vestibular nerve afferents innervating the bullfrog utriculus differ in their response dynamics and sensitivity to natural stimulation. They also supply hair cells that differ markedly in hair bundle morphology. To examine the peripheral innervation patterns of individual utricular afferents more closely, afferent fibers were labeled by the extracellular injection of horseradish peroxidase (HRP) into the vestibular nerve after sectioning the vestibular nerve medial to Scarpa's ganglion to allow the degeneration of sympathetic and efferent fibers. The peripheral arborizations of individual afferents were then correlated with the diameters of their parent axons, the regions of the macula they innervate, and the number and type of hair cells they supply. The utriculus is divided by the striola, a narrow zone of distinctive morphology, into media and lateral parts. Utiricular afferents were classified as striolar or extrastriolar according to the epithelial entrance of their parent axons and the location of their terminal fields. In general, striolar afferents had thicker parent axons, fewer subepithelial bifurcations, larger terminal fields, and more synaptic endings than afferents in extrstriolar regions. Afferents in a juxtastriolar zone, immediately adjacent to the medial striola, had innervation patterns transitional between those in the striola and more peripheral parts of the medial extrastriola. moast afferents innervated only a single macular zone. The terminal fields of striolar afferents, with the notable exception of a few afferents with thin parent axons, were generally confined to one side of the striola. Hair cells in the bullfrog utriculus have perviously been classified into four types based on hair bundle morphology. Afferents in the extrastriolar and juxtastriolar zones largely or exclusively innervated Type B hair cells, the predominant hair cell type in the utricular macula. Striolar afferents supplied a mixture of four hair cell types, but largely

Double muscle innervation using end-to-side neurorrhaphy in rats

Directory of Open Access Journals (Sweden)

Elisangela Jeronymo Stipp-Brambilla

Full Text Available CONTEXT AND OBJECTIVE: One of the techniques used for treating facial paralysis is double muscle innervation using end-to-end neurorrhaphy with sectioning of healthy nerves. The aim of this study was to evaluate whether double muscle innervation by means of end-to-side neurorrhaphy could occur, with maintenance of muscle innervation. DESIGN AND SETTING: Experimental study developed at the Experimental Research Center, Faculdade de Medicina de Botucatu, Unesp. METHODS: One hundred rats were allocated to five groups as follows: G1, control group; G2, the peroneal nerve was sectioned; G3, the tibial nerve was transected and the proximal stump was end-to-side sutured to the intact peroneal nerve; G4, 120 days after the G3 surgery, the peroneal nerve was sectioned proximally to the neurorrhaphy; G5, 120 days after the G3 surgery, the peroneal and tibial nerves were sectioned proximally to the neurorrhaphy. RESULTS: One hundred and fifty days after the surgery, G3 did not show any change in tibial muscle weight or muscle fiber diameter, but the axonal fiber diameter in the peroneal nerve distal to the neurorrhaphy had decreased. Although G4 showed atrophy of the cranial tibial muscle 30 days after sectioning the peroneal nerve, the electrophysiological test results and axonal diameter measurement confirmed that muscle reinnervation had occurred. CONCLUSION: These findings suggest that double muscle innervation did not occur through end-to-side neurorrhaphy; the tibial nerve was not able to maintain muscle innervation after the peroneal nerve had been sectioned, although muscle reinnervation was found to have occurred, 30 days after the peroneal nerve had been sectioned.

Development of the intrinsic and extrinsic innervation of the gut.

Science.gov (United States)

Uesaka, Toshihiro; Young, Heather M; Pachnis, Vassilis; Enomoto, Hideki

2016-09-15

The gastrointestinal (GI) tract is innervated by intrinsic enteric neurons and by extrinsic efferent and afferent nerves. The enteric (intrinsic) nervous system (ENS) in most regions of the gut consists of two main ganglionated layers; myenteric and submucosal ganglia, containing numerous types of enteric neurons and glial cells. Axons arising from the ENS and from extrinsic neurons innervate most layers of the gut wall and regulate many gut functions. The majority of ENS cells are derived from vagal neural crest cells (NCCs), which proliferate, colonize the entire gut, and first populate the myenteric region. After gut colonization by vagal NCCs, the extrinsic nerve fibers reach the GI tract, and Schwann cell precursors (SCPs) enter the gut along the extrinsic nerves. Furthermore, a subpopulation of cells in myenteric ganglia undergoes a radial (inward) migration to form the submucosal plexus, and the intrinsic and extrinsic innervation to the mucosal region develops. Here, we focus on recent progress in understanding the developmental processes that occur after the gut is colonized by vagal ENS precursors, and provide an up-to-date overview of molecular mechanisms regulating the development of the intrinsic and extrinsic innervation of the GI tract. Copyright © 2016 Elsevier Inc. All rights reserved.

Laminin and Matrix metalloproteinase 11 regulate Fibronectin levels in the zebrafish myotendinous junction.

Science.gov (United States)

Jenkins, Molly H; Alrowaished, Sarah S; Goody, Michelle F; Crawford, Bryan D; Henry, Clarissa A

2016-01-01

Remodeling of the extracellular matrix (ECM) regulates cell adhesion as well as signaling between cells and their microenvironment. Despite the importance of tightly regulated ECM remodeling for normal muscle development and function, mechanisms underlying ECM remodeling in vivo remain elusive. One excellent paradigm in which to study ECM remodeling in vivo is morphogenesis of the myotendinous junction (MTJ) during zebrafish skeletal muscle development. During MTJ development, there are dramatic shifts in the primary components comprising the MTJ matrix. One such shift involves the replacement of Fibronectin (Fn)-rich matrix, which is essential for both somite and early muscle development, with laminin-rich matrix essential for normal function of the myotome. Here, we investigate the mechanism underlying this transition. We show that laminin polymerization indirectly promotes Fn downregulation at the MTJ, via a matrix metalloproteinase 11 (Mmp11)-dependent mechanism. Laminin deposition and organization is required for localization of Mmp11 to the MTJ, where Mmp11 is both necessary and sufficient for Fn downregulation in vivo. Furthermore, reduction of residual Mmp11 in laminin mutants promotes a Fn-rich MTJ that partially rescues skeletal muscle architecture. These results identify a mechanism for Fn downregulation at the MTJ, highlight crosstalk between laminin and Fn, and identify a new in vivo function for Mmp11. Taken together, our data demonstrate a novel signaling pathway mediating Fn downregulation. Our data revealing new regulatory mechanisms that guide ECM remodeling during morphogenesis in vivo may inform pathological conditions in which Fn is dysregulated.

Taste Bud-Derived BDNF Is Required to Maintain Normal Amounts of Innervation to Adult Taste Buds.

Science.gov (United States)

Meng, Lingbin; Ohman-Gault, Lisa; Ma, Liqun; Krimm, Robin F

2015-01-01

Gustatory neurons transmit chemical information from taste receptor cells, which reside in taste buds in the oral cavity, to the brain. As adult taste receptor cells are renewed at a constant rate, nerve fibers must reconnect with new taste receptor cells as they arise. Therefore, the maintenance of gustatory innervation to the taste bud is an active process. Understanding how this process is regulated is a fundamental concern of gustatory system biology. We speculated that because brain-derived neurotrophic factor (BDNF) is required for taste bud innervation during development, it might function to maintain innervation during adulthood. If so, taste buds should lose innervation when Bdnf is deleted in adult mice. To test this idea, we first removed Bdnf from all cells in adulthood using transgenic mice with inducible CreERT2 under the control of the Ubiquitin promoter. When Bdnf was removed, approximately one-half of the innervation to taste buds was lost, and taste buds became smaller because of the loss of taste bud cells. Individual taste buds varied in the amount of innervation each lost, and those that lost the most innervation also lost the most taste bud cells. We then tested the idea that that the taste bud was the source of this BDNF by reducing Bdnf levels specifically in the lingual epithelium and taste buds. Taste buds were confirmed as the source of BDNF regulating innervation. We conclude that BDNF expressed in taste receptor cells is required to maintain normal levels of innervation in adulthood.

Engine Cylinder Temperature Control

Science.gov (United States)

Kilkenny, Jonathan Patrick; Duffy, Kevin Patrick

2005-09-27

A method and apparatus for controlling a temperature in a combustion cylinder in an internal combustion engine. The cylinder is fluidly connected to an intake manifold and an exhaust manifold. The method and apparatus includes increasing a back pressure associated with the exhaust manifold to a level sufficient to maintain a desired quantity of residual exhaust gas in the cylinder, and varying operation of an intake valve located between the intake manifold and the cylinder to an open duration sufficient to maintain a desired quantity of fresh air from the intake manifold to the cylinder, wherein controlling the quantities of residual exhaust gas and fresh air are performed to maintain the temperature in the cylinder at a desired level.

Delamination of Composite Cylinders

Science.gov (United States)

Davies, Peter; Carlsson, Leif A.

The delamination resistance of filament wound glass/epoxy cylinders has been characterized for a range of winding angles and fracture mode ratios using beam fracture specimens. The results reveal that the delamination fracture resistance increases with increasing winding angle and mode II (shear) fraction (GΠ/G). It was also found that interlaced fiber bundles in the filament wound cylinder wall acted as effective crack arresters in mode I loading. To examine the sensitivity of delamina-tion damage on the strength of the cylinders, external pressure tests were performed on filament-wound glass/epoxy composite cylinders with artificial defects and impact damage. The results revealed that the cylinder strength was insensitive to the presence of single delaminations but impact damage caused reductions in failure pressure. The insensitivity of the failure pressure to a single delamination is attributed to the absence of buckling of the delaminated sublaminates before the cylinder wall collapsed. The impacted cylinders contained multiple delaminations, which caused local reduction in the compressive load capability and reduction in failure pressure. The response of glass/epoxy cylinders was compared to impacted carbon reinforced cylinders. Carbon/epoxy is more sensitive to damage but retains higher implosion resistance while carbon/PEEK shows the opposite trend.

Internal combustion engine cylinder-to-cylinder balancing with balanced air-fuel ratios

Science.gov (United States)

Harris, Ralph E.; Bourn, Gary D.; Smalley, Anthony J.

2006-01-03

A method of balancing combustion among cylinders of an internal combustion engine. For each cylinder, a normalized peak firing pressure is calculated as the ratio of its peak firing pressure to its combustion pressure. Each cylinder's normalized peak firing pressure is compared to a target value for normalized peak firing pressure. The fuel flow is adjusted to any cylinder whose normalized peak firing pressure is not substantially equal to the target value.

Neurons of self-defence: neuronal innervation of the exocrine defence glands in stick insects.

Science.gov (United States)

Stolz, Konrad; von Bredow, Christoph-Rüdiger; von Bredow, Yvette M; Lakes-Harlan, Reinhard; Trenczek, Tina E; Strauß, Johannes

2015-01-01

Stick insects (Phasmatodea) use repellent chemical substances (allomones) for defence which are released from so-called defence glands in the prothorax. These glands differ in size between species, and are under neuronal control from the CNS. The detailed neural innervation and possible differences between species are not studied so far. Using axonal tracing, the neuronal innervation is investigated comparing four species. The aim is to document the complexity of defence gland innervation in peripheral nerves and central motoneurons in stick insects. In the species studied here, the defence gland is innervated by the intersegmental nerve complex (ISN) which is formed by three nerves from the prothoracic (T1) and suboesophageal ganglion (SOG), as well as a distinct suboesophageal nerve (Nervus anterior of the suboesophageal ganglion). In Carausius morosus and Sipyloidea sipylus, axonal tracing confirmed an innervation of the defence glands by this N. anterior SOG as well as N. anterior T1 and N. posterior SOG from the intersegmental nerve complex. In Peruphasma schultei, which has rather large defence glands, only the innervation by the N. anterior SOG was documented by axonal tracing. In the central nervous system of all species, 3-4 neuron types are identified by axonal tracing which send axons in the N. anterior SOG likely innervating the defence gland as well as adjacent muscles. These neurons are mainly suboesophageal neurons with one intersegmental neuron located in the prothoracic ganglion. The neuron types are conserved in the species studied, but the combination of neuron types is not identical. In addition, the central nervous system in S. sipylus contains one suboesophageal and one prothoracic neuron type with axons in the intersegmental nerve complex contacting the defence gland. Axonal tracing shows a very complex innervation pattern of the defence glands of Phasmatodea which contains different neurons in different nerves from two adjacent body segments

Quantified distribution of the noradrenaline innervation in the hippocampus of adult rat

International Nuclear Information System (INIS)

Oleskevich, S.; Descarries, L.; Lacaille, J.C.

1989-01-01

A recently developed radioautographic technique, based on the uptake labeling of monoamine terminals in vitro, was used to quantify the noradrenaline (NA) innervation in adult rat hippocampus. After incubation of brain slices with 1 microM 3H-NA, the NA varicosities were visualized as small aggregates of silver grains, in light microscope radioautographs prepared at 3 equidistant horizontal levels across the ventral 2/3 of the hippocampus. Using a computer-assisted image analyzer, counts were obtained from the subiculum (SUB), 3 sectors of Ammon's horn (CA1, CA3-a, CA3-b) and 3 sectors of the dentate gyrus (DG-medial blade, crest, and lateral blade), every lamina being sampled in each region. After a double correction for duration of radioautographic exposure and section thickness, and following measurement of varicosity diameter in electron microscope radioautographs, it was possible to express these results in number of terminals per volumetric unit of tissue. It was thus found that the overall density of hippocampal NA innervation averages 2.1 million varicosities/mm3 of tissue, a value almost twice as high as that in cerebral cortex. This innervation is 20% denser ventrally than dorsally and is heterogeneous both in terms of regional and laminar distribution. SUB and DG are more strongly innervated than Ammon's horn, wherein CA1 has the lowest overall density. In SUB and CA1, there is a clear predilection of NA varicosities for the stratum moleculare. In CA3, there is a narrow band of even stronger innervation in the stratum radiatum, near the apical border of the stratum pyramidale, contrasting with a 3 times lower density in this cell layer and the stratum oriens. In DG, the NA innervation is again the weakest in the cell body layer and exhibits an almost 3-fold greater density in the polymorph layer, the highest of all hippocampus

Sympathetic Innervation during Development Is Necessary for Pancreatic Islet Architecture and Functional Maturation

Directory of Open Access Journals (Sweden)

Philip Borden

2013-07-01

Full Text Available Sympathetic neurons depend on target-derived neurotrophic cues to control their survival and growth. However, whether sympathetic innervation contributes reciprocally to the development of target tissues is less clear. Here, we report that sympathetic innervation is necessary for the formation of the pancreatic islets of Langerhans and for their functional maturation. Genetic or pharmacological ablation of sympathetic innervation during development resulted in altered islet architecture, reduced insulin secretion, and impaired glucose tolerance in mice. Similar defects were observed with pharmacological blockade of β-adrenergic signaling. Conversely, the administration of a β-adrenergic agonist restored islet morphology and glucose tolerance in deinnervated animals. Furthermore, in neuron-islet cocultures, sympathetic neurons promoted islet cell migration in a β-adrenergic-dependent manner. This study reveals that islet architecture requires extrinsic inductive cues from neighboring tissues such as sympathetic nerves and suggests that early perturbations in sympathetic innervation might underlie metabolic disorders.

The human thoracic duct is functionally innervated by adrenergic nerves

DEFF Research Database (Denmark)

Telinius, Niklas; Baandrup, Ulrik; Rumessen, Jüri Johs.

2013-01-01

) that is predominantly adrenergic. TDs harvested from 51 patients undergoing esophageal and cardia cancer surgery were either fixed for structural investigations or maintained in vitro for the functional assessment of innervation by isometric force measurements and electrical field stimulation (EFS). Electron microscopy......, and methacholine was demonstrated by exogenous application to human TD ring segments. Norepinephrine provided the most consistent responses, whereas responses to the other agonists varied. We conclude that the human TD is functionally innervated with both cholinergic and adrenergic components, with the latter...

Relationships between cardiac innervation/perfusion imbalance and ventricular arrhythmias: impact on invasive electrophysiological parameters and ablation procedures

International Nuclear Information System (INIS)

Gimelli, Alessia; Menichetti, Francesca; Soldati, Ezio; Liga, Riccardo; Vannozzi, Andrea; Bongiorni, Maria Grazia; Marzullo, Paolo

2016-01-01

To assess the relationship between regional myocardial perfusion and sympathetic innervation parameters at myocardial scintigraphy and intra-cavitary electrophysiological data in patients with ventricular arrhythmias (VA) submitted to invasive electrophysiological study and ablation procedure. Sixteen subjects underwent invasive electrophysiological study with electroanatomical mapping (EAM) followed by trans-catheter ablations of VA. Before ablation all patients were studied with a combined evaluation of regional myocardial perfusion and sympathetic innervation by means of tomographic "9"9"mTc-tetrofosmin and "1"2"3I- metaiodobenzylguanidine cadmium-zinc-telluride (CZT) scintigraphies, respectively. Off-line spatial co-registration of CZT perfusion and innervation data with the three-dimensional EAM reconstruction was performed in every patient. CZT revealed the presence of myocardial scar in 55 (20 %) segments. Of the viable myocardial segments, 131 (60 %) presented a preserved adrenergic innervation, while 86 (40 %) showed a significantly depressed innervation (i.e. innervation/perfusion mismatch). On EAM, the invasively measured intra-cavitary voltage was significantly lower in scarred segments than in viable ones (1.7 ± 1.5 mV vs. 4.0 ± 2.2 mV, P < 0.001). Interestingly, among the viable segments, those showing an innervation/perfusion mismatch presented a significantly lower intra-cavitary voltage than those with preserved innervation (1.9 ± 2.5 mV vs. 4.7 ± 2.3 mV, P < 0.001). Intra-cardiac ablation was performed in 63 (23 %) segments. On multivariate analysis, after correction for scar burden, the segments showing an innervation/perfusion mismatch remained the most frequent ablation targets (OR 5.6, 95 % CI 1.5-20.8; P = 0.009). In patients with VA, intra-cavitary electrical abnormalities frequently originate at the level of viable myocardial segments with depressed sympathetic innervation that frequently represents the ultimate ablation target. (orig.)

Relationships between cardiac innervation/perfusion imbalance and ventricular arrhythmias: impact on invasive electrophysiological parameters and ablation procedures

Energy Technology Data Exchange (ETDEWEB)

Gimelli, Alessia [Fondazione Toscana Gabriele Monasterio, Pisa (Italy); Menichetti, Francesca; Soldati, Ezio; Liga, Riccardo; Vannozzi, Andrea; Bongiorni, Maria Grazia [University Hospital of Pisa, Cardio-Thoracic and Vascular Department, Pisa (Italy); Marzullo, Paolo [Fondazione Toscana Gabriele Monasterio, Pisa (Italy); CNR, Institute of Clinical Physiology, Pisa (Italy)

2016-12-15

To assess the relationship between regional myocardial perfusion and sympathetic innervation parameters at myocardial scintigraphy and intra-cavitary electrophysiological data in patients with ventricular arrhythmias (VA) submitted to invasive electrophysiological study and ablation procedure. Sixteen subjects underwent invasive electrophysiological study with electroanatomical mapping (EAM) followed by trans-catheter ablations of VA. Before ablation all patients were studied with a combined evaluation of regional myocardial perfusion and sympathetic innervation by means of tomographic {sup 99m}Tc-tetrofosmin and {sup 123}I- metaiodobenzylguanidine cadmium-zinc-telluride (CZT) scintigraphies, respectively. Off-line spatial co-registration of CZT perfusion and innervation data with the three-dimensional EAM reconstruction was performed in every patient. CZT revealed the presence of myocardial scar in 55 (20 %) segments. Of the viable myocardial segments, 131 (60 %) presented a preserved adrenergic innervation, while 86 (40 %) showed a significantly depressed innervation (i.e. innervation/perfusion mismatch). On EAM, the invasively measured intra-cavitary voltage was significantly lower in scarred segments than in viable ones (1.7 ± 1.5 mV vs. 4.0 ± 2.2 mV, P < 0.001). Interestingly, among the viable segments, those showing an innervation/perfusion mismatch presented a significantly lower intra-cavitary voltage than those with preserved innervation (1.9 ± 2.5 mV vs. 4.7 ± 2.3 mV, P < 0.001). Intra-cardiac ablation was performed in 63 (23 %) segments. On multivariate analysis, after correction for scar burden, the segments showing an innervation/perfusion mismatch remained the most frequent ablation targets (OR 5.6, 95 % CI 1.5-20.8; P = 0.009). In patients with VA, intra-cavitary electrical abnormalities frequently originate at the level of viable myocardial segments with depressed sympathetic innervation that frequently represents the ultimate ablation target

Innervation Patterns of Sea Otter (Enhydra lutris Mystacial Follicle-Sinus Complexes

Directory of Open Access Journals (Sweden)

Christopher Douglas Marshall

2014-10-01

Full Text Available Sea otters (Enhydra lutris are the most recent group of mammals to return to the sea, and may exemplify divergent somatosensory tactile systems among mammals. Therefore, we quantified the mystacial vibrissal array of sea otters and histologically processed follicle-sinus complexes (F-SCs to test the hypotheses that the number of myelinated axons per F-SC is greater than that found for terrestrial mammalian vibrissae and that their organization and microstructure converge with those of pinniped vibrissae. A mean of 120.5 vibrissae were arranged rostrally on a broad, blunt muzzle in 7-8 rows and 9-13 columns. The F-SCs of sea otters are tripartite in their organization and similar in microstructure to pinnipeds rather than terrestrial species. Each F-SC was innervated by a mean 1339±408.3 axons. Innervation to the entire mystacial vibrissal array was estimated at 161,313 axons. Our data support the hypothesis that the disproportionate expansion of the coronal gyrus in somatosensory cortex of sea otters is related to the high innervation investment of the mystacial vibrissal array, and that quantifying innervation investment is a good proxy for tactile sensitivity. We predict that the tactile performance of sea otter mystacial vibrissae is comparable to that of harbor seals, sea lions and walruses¬.

Taste Bud-Derived BDNF Is Required to Maintain Normal Amounts of Innervation to Adult Taste Buds123

Science.gov (United States)

Meng, Lingbin; Ohman-Gault, Lisa; Ma, Liqun

2015-01-01

Abstract Gustatory neurons transmit chemical information from taste receptor cells, which reside in taste buds in the oral cavity, to the brain. As adult taste receptor cells are renewed at a constant rate, nerve fibers must reconnect with new taste receptor cells as they arise. Therefore, the maintenance of gustatory innervation to the taste bud is an active process. Understanding how this process is regulated is a fundamental concern of gustatory system biology. We speculated that because brain-derived neurotrophic factor (BDNF) is required for taste bud innervation during development, it might function to maintain innervation during adulthood. If so, taste buds should lose innervation when Bdnf is deleted in adult mice. To test this idea, we first removed Bdnf from all cells in adulthood using transgenic mice with inducible CreERT2 under the control of the Ubiquitin promoter. When Bdnf was removed, approximately one-half of the innervation to taste buds was lost, and taste buds became smaller because of the loss of taste bud cells. Individual taste buds varied in the amount of innervation each lost, and those that lost the most innervation also lost the most taste bud cells. We then tested the idea that that the taste bud was the source of this BDNF by reducing Bdnf levels specifically in the lingual epithelium and taste buds. Taste buds were confirmed as the source of BDNF regulating innervation. We conclude that BDNF expressed in taste receptor cells is required to maintain normal levels of innervation in adulthood. PMID:26730405

Gas Cylinder Safety, Course 9518

Energy Technology Data Exchange (ETDEWEB)

Glass, George [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-10-27

This course, Gas Cylinder Safety (#9518), presents an overview of the hazards and controls associated with handling, storing, using, and transporting gas cylinders. Standard components and markings of gas cylinders are also presented, as well as the process for the procurement, delivery, and return of gas cylinders at Los Alamos National Laboratory (LANL).

Fiber Tracking Cylinder Nesting

International Nuclear Information System (INIS)

Stredde, H.

1999-01-01

The fiber tracker consists of 8 concentric carbon fiber cylinders of varying diameters, from 399mm to 1032.2mm and two different lengths. 1.66 and 2.52 meters. Each completed cylinder is covered over the entire o.d. with scintillating fiber ribbons with a connector on each ribbon. These ribbons are axial (parallel to the beam line) at one end and stereo (at 3 deg. to the beam line) at the other. The ribbon connectors have dowel pins which are used to match with the connectors on the wave guide ribbons. These dowel pins are also used during the nesting operation, locating and positioning measurements. The nesting operation is the insertion of one cylinder into another, aligning them with one another and fastening them together into a homogeneous assembly. For ease of assembly. the nesting operation is accomplished working from largest diameter to smallest. Although the completed assembly of all 8 cylinders glued and bolted together is very stiff. individual cylinders are relatively flexible. Therefore. during this operation, No.8 must be supported in a manner which maintains its integrity and yet allows the insertion of No.7. This is accomplished by essentially building a set of dummy end plates which replicate a No.9 cylinder. These end plates are mounted on a wheeled cart that becomes the nesting cart. Provisions for a protective cover fastened to these rings has been made and will be incorporated in finished product. These covers can be easily removed for access to No.8 and/or the connection of No.8 to No.9. Another wheeled cart, transfer cart, is used to push a completed cylinder into the cylinder(s) already mounted in the nesting cart.

Innervation of the Anterior Sacroiliac Joint.

Science.gov (United States)

Cox, Marcus; Ng, Garrett; Mashriqi, Faizullah; Iwanaga, Joe; Alonso, Fernando; Tubbs, Kevin; Loukas, Marios; Oskouian, Rod J; Tubbs, R Shane

2017-11-01

Sacroiliac joint pain can be disabling and recalcitrant to medical therapy. The innervation of this joint is poorly understood, especially its anterior aspect. Therefore, the present cadaveric study was performed to better elucidate this anatomy. Twenty-four cadaveric sides underwent dissection of the anterior sacroiliac joint, with special attention given to any branches from regional nerves to this joint. No femoral, obturator, or lumbosacral trunk branches destined to the anterior sacroiliac joint were identified in the 24 sides. In 20 sides, one or two small branches (less than 0.5 mm in diameter) were found to arise from the L4 ventral ramus (10%), the L5 ventral ramus (80%), or simultaneously from both the L4 and L5 ventral rami (10%). The length of the branches ranged from 5 to 31 mm (mean, 14 mm). All these branches arose from the posterior part of the nerves and traveled to the anterior surface of the sacroiliac joint. No statistical significance was found between sides or sexes. An improved knowledge of the innervation of the anterior sacroiliac joint might decrease suffering in patients with chronic sacroiliac joint pain. Copyright © 2017 Elsevier Inc. All rights reserved.

Antennas on circular cylinders

DEFF Research Database (Denmark)

Knudsen, H. L.

1959-01-01

On the basis of the results obtained by Silver and Saunders [4] for the field radiated from an arbitrary slot in a perfectly conducting circular cylinder, expressions have been derived for the field radiated by a narrow helical slot, with an arbitrary aperture field distribution, in a circular...... antenna in a circular cylinder. By a procedure similar to the one used by Silver and Saunders, expressions have been derived for the field radiated from an arbitrary surface current distribution on a cylinder surface coaxial with a perfectly conducting cylinder. The cases where the space between the two...

Wake flow behaviour behind a smaller cylinder oscillating in the wake of an upstream stationary cylinder

Energy Technology Data Exchange (ETDEWEB)

Gao, Yangyang; Sun, Zhilin [Ocean College, Zhejiang University, Hangzhou 310058 (China); Tan, Danielle S [Maritime Research Centre, Nanyang Technological University, Singapore 639798 (Singapore); Yu, Dingyong [College of Engineering, Ocean University of China, 266100 (China); Tan, Soon Keat, E-mail: yygao@zju.edu.cn [Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore 639798 (Singapore)

2014-04-01

The flow patterns around a cylinder oscillating freely in the wake of a larger cylinder upstream were investigated using the particle image velocimetry technique. The upstream cylinder was fixed at both ends while the downstream smaller cylinder was held by springs such that it was free to oscillate in the transverse direction. The flow patterns, amplitudes of oscillation and vortex shedding frequencies were compared with those of a single cylinder. In the presence of the upstream cylinder, the three parameters characterizing the oscillation response of the smaller cylinder—amplitude of oscillation, vortex shedding frequency and Reynolds stresses—were greatly reduced. While their magnitude increased with gap ratio, these three parameters were still smaller than the corresponding magnitudes for a single oscillating cylinder. The peak values of turbulence statistics such as Reynolds shear stress and normal stress behind the oscillating downstream cylinder were similarly reduced, and increased with gap ratios. (paper)

Synaptic Plasticity in Cardiac Innervation and Its Potential Role in Atrial Fibrillation

OpenAIRE

Jesse L. Ashton; Rebecca A. B. Burton; Gil Bub; Bruce H. Smaill; Bruce H. Smaill; Johanna M. Montgomery

2018-01-01

Synaptic plasticity is defined as the ability of synapses to change their strength of transmission. Plasticity of synaptic connections in the brain is a major focus of neuroscience research, as it is the primary mechanism underpinning learning and memory. Beyond the brain however, plasticity in peripheral neurons is less well understood, particularly in the neurons innervating the heart. The atria receive rich innervation from the autonomic branch of the peripheral nervous system. Sympathetic...

Innervation pattern of the suprascapular nerve within supraspinatus: a three-dimensional computer modeling study.

Science.gov (United States)

Hermenegildo, J A; Roberts, S L; Kim, S Y

2014-05-01

The relationship between the innervation pattern of the suprascapular nerve (SSN) and the muscle architecture of supraspinatus has not been thoroughly investigated. The supraspinatus is composed of two architecturally distinct regions: anterior and posterior. Each of these regions is further subdivided into three parts: superficial, middle and deep. The purpose of this study was to investigate the course of the SSN throughout the volume of supraspinatus and to relate the intramuscular branches to the distinct regions and parts of the supraspinatus. The SSN was dissected in thirty formalin embalmed cadaveric specimens and digitized throughout the muscle volume in six of those specimens. The digitized data were modeled using Autodesk(®) Maya(®) 2011. The three-dimensional (3D) models were used to relate the intramuscular innervation pattern to the muscle and tendon architecture defined by Kim et al. (2007, Clin Anat 20:648-655). The SSN bifurcated into two main trunks: medial and lateral. All parts of the anterior region were predominantly innervated by the medial trunk and its proximal and medial branches, whereas all parts of the posterior region predominantly by the lateral trunk and its posterolateral and/or posteromedial branches. The posterior region also received innervation from the proximal branch of the medial trunk in half of the specimens. These findings provide evidence that the anterior and posterior regions are distinct with respect to their innervation. The 3D map of the innervation pattern will aid in planning future clinical studies investigating muscle activation patterns and provide insight into possible injury of the nerve with supraspinatus pathology and surgical techniques. Copyright © 2013 Wiley Periodicals, Inc.

Autonomic cardiac innervation

Science.gov (United States)

Hasan, Wohaib

2013-01-01

Autonomic cardiac neurons have a common origin in the neural crest but undergo distinct developmental differentiation as they mature toward their adult phenotype. Progenitor cells respond to repulsive cues during migration, followed by differentiation cues from paracrine sources that promote neurochemistry and differentiation. When autonomic axons start to innervate cardiac tissue, neurotrophic factors from vascular tissue are essential for maintenance of neurons before they reach their targets, upon which target-derived trophic factors take over final maturation, synaptic strength and postnatal survival. Although target-derived neurotrophins have a central role to play in development, alternative sources of neurotrophins may also modulate innervation. Both developing and adult sympathetic neurons express proNGF, and adult parasympathetic cardiac ganglion neurons also synthesize and release NGF. The physiological function of these “non-classical” cardiac sources of neurotrophins remains to be determined, especially in relation to autocrine/paracrine sustenance during development.   Cardiac autonomic nerves are closely spatially associated in cardiac plexuses, ganglia and pacemaker regions and so are sensitive to release of neurotransmitter, neuropeptides and trophic factors from adjacent nerves. As such, in many cardiac pathologies, it is an imbalance within the two arms of the autonomic system that is critical for disease progression. Although this crosstalk between sympathetic and parasympathetic nerves has been well established for adult nerves, it is unclear whether a degree of paracrine regulation occurs across the autonomic limbs during development. Aberrant nerve remodeling is a common occurrence in many adult cardiovascular pathologies, and the mechanisms regulating outgrowth or denervation are disparate. However, autonomic neurons display considerable plasticity in this regard with neurotrophins and inflammatory cytokines having a central regulatory

Magnetic resonance imaging patterns of mononeuropathic denervation in muscles with dual innervation

Energy Technology Data Exchange (ETDEWEB)

Sneag, Darryl B.; Lee, Susan C.; Melisaratus, Darius P. [Hospital for Special Surgery, Department of Radiology and Imaging, New York, NY (United States); Feinberg, Joseph H. [Physical Medicine and Rehabilitation, Hospital for Special Surgery, New York, NY (United States); Amber, Ian [MedStar Georgetown University Hospital, Department of Radiology, DC, Washington (United States)

2017-12-15

Magnetic resonance imaging (MRI) of mononeuropathy in muscles with dual innervation depicts geographic denervation corresponding to the affected nerve. Knowledge of the normal distribution of a muscle's neural supply is clinically relevant as partial muscle denervation represents a potential imaging pitfall that can be confused with other pathology, such as muscle strain. This article reviews the normal innervation pattern of extremity muscles with dual supply, providing illustrative examples of mononeuropathy affecting such muscles. (orig.)

Magnetic resonance imaging patterns of mononeuropathic denervation in muscles with dual innervation

International Nuclear Information System (INIS)

Sneag, Darryl B.; Lee, Susan C.; Melisaratus, Darius P.; Feinberg, Joseph H.; Amber, Ian

2017-01-01

Magnetic resonance imaging (MRI) of mononeuropathy in muscles with dual innervation depicts geographic denervation corresponding to the affected nerve. Knowledge of the normal distribution of a muscle's neural supply is clinically relevant as partial muscle denervation represents a potential imaging pitfall that can be confused with other pathology, such as muscle strain. This article reviews the normal innervation pattern of extremity muscles with dual supply, providing illustrative examples of mononeuropathy affecting such muscles. (orig.)

Early Corneal Innervation and Trigeminal Alterations in Parkinson Disease: A Pilot Study.

Science.gov (United States)

Arrigo, Alessandro; Rania, Laura; Calamuneri, Alessandro; Postorino, Elisa Imelde; Mormina, Enricomaria; Gaeta, Michele; Marino, Silvia; Di Lorenzo, Giuseppe; Quartarone, Angelo; Anastasi, Giuseppe; Puzzolo, Domenico; Aragona, Pasquale

2018-04-01

To describe corneal innervation and trigeminal alterations in drug-naive patients with Parkinson disease (PD). A case series study was conducted by recruiting 3 early drug-naive patients with PD, 2 men and 1 woman (age: 72, 68, and 66, respectively). Ophthalmologic assessment included Ocular Surface Disease Index questionnaire, visual acuity by the logarithm of the minimum angle of resolution score, pupillary light reflexes, extrinsic ocular movements, corneal sensitivity, and slit-lamp examination. Corneal innervation parameter changes were evaluated in vivo using the Confoscan 4 confocal microscope, and they were compared with a control data set. The Heidelberg Retina Tomograph 3 (HRT3) has been used to assess retinal alterations in our patients, if compared with normal range values provided by the HRT3. Moreover, 3T magnetic resonance imaging (MRI) analysis of water diffusion property changes of trigeminal nerves was performed. All data were analyzed and compared with 2 control data sets made by 14 age-matched controls. Patients with PD showed profound alterations of corneal innervation and of trigeminal diffusion MRI parameters, compared with controls. Strong differences (PD vs. controls) were found for deep nerve tortuosity (Kallinikos mean 19.94 vs. 2.13) and the number of beadings (mean 34.2 vs. 15.5). HRT3 retinal evaluation revealed less structural changes compared with the normal range. Diffusion MRI showed profound changes of white matter diffusion properties (PD vs. controls), with fractional anisotropy decrement (mean 0.3029 vs. 0.3329) and mean diffusivity increment (mean 0.00127 vs. 0.00106). Corneal innervation changes might occur earlier in patients with PD than in retinal ones. Confocal corneal innervation analysis might provide possible early biomarkers for a better PD evaluation and for its earlier diagnosis.

Effect of longitudinal and transverse vibrations of an upstream square cylinder on vortex shedding behind two inline square cylinders

International Nuclear Information System (INIS)

Patil, Pratish P; Tiwari, Shaligram

2009-01-01

The characteristics of unsteady wakes behind a stationary square cylinder and another upstream vibrating square cylinder have been investigated numerically with the help of a developed computational code. The effect of longitudinal as well as transverse vibrations of the upstream cylinder is studied on the coupled wake between the two cylinders, which is found to control the vortex shedding behavior behind the downstream stationary cylinder. Computations are carried out for a fixed value of Reynolds number (Re = 200) and three different values of excitation frequencies of the upstream cylinder, namely less than, equal to and greater than the natural frequency of vortex shedding corresponding to flow past a stationary square cylinder. The vortex shedding characteristics of the unsteady wakes behind the vibrating and stationary cylinders are found to differ significantly for longitudinal and transverse modes of vibration of the upstream cylinder. The wake of the downstream stationary cylinder is found to depict a synchronization behavior with the upstream cylinder vibration. The spacing between the two cylinders has been identified to be the key parameter influencing the synchronization phenomenon. The effect of cylinder spacing on the wake synchronization and the hydrodynamic forces has been examined. In addition, a comparison of the drag forces for flow past transversely vibrating square and circular cylinders for similar amplitudes and frequencies of cylinder vibration has been presented while employing the tested computational code.

Reduced Sympathetic Innervation in Endometriosis is Associated to Semaphorin 3C and 3F Expression.

Science.gov (United States)

Scheerer, Claudia; Frangini, Sergio; Chiantera, Vito; Mechsner, Sylvia

2017-09-01

Endometriosis is a chronic inflammatory disease and one of the most common causes of pelvic pain. The mechanisms underlying pain emergence or chronic inflammation during endometriosis remain unknown. Several chronic inflammatory diseases including endometriosis show reduced amounts of noradrenergic nerve fibers. The source of the affected innervation is still unclear. Semaphorins represent potential elicitors, due to their known role as axonal guidance cues, and are suggested as nerve repellent factors in different chronic inflammatory diseases. Therefore, semaphorins might influence the progress of neuroinflammatory mechanisms during endometriosis. Here, we analyzed the noradrenergic innervation and the expression of the specific semaphorins and receptors possibly involved in the neuroimmunomodulation in endometriosis. Our studies revealed an affected innervation and a significant increase of semaphorins and their receptors in peritoneal endometriotic tissue. Thereby, the expression of the receptors was identified on the membrane of noradrenergic nerve fibers and vessels. Macrophages and activated fibroblasts were found in higher density levels and additionally express semaphorins in peritoneal endometriotic tissue. Inflammation leads to an increased release of immune cells, which secrete a variety of inflammatory factors capable of affecting innervation. Therefore, our data suggests that the chronic inflammatory condition in endometriosis might contribute to the increase of semaphorins, which could possibly affect the innervation in peritoneal endometriosis.

Dynamic Friction Performance of a Pneumatic Cylinder with Al2O3 Film on Cylinder Surface.

Science.gov (United States)

Chang, Ho; Lan, Chou-Wei; Wang, Hao-Xian

2015-11-01

A friction force system is proposed for accurately measuring friction force and motion properties produced by reciprocating motion of piston in a pneumatic cylinder. In this study, the proposed system is used to measure the effects of lubricating greases of different viscosities on the friction properties of pneumatic cylinder, and improvement of stick-slip motion for the cylinder bore by anodizing processes. A servo motor-driven ball screw is used to drive the pneumatic cylinder to be tested and to measure the change in friction force of the pneumatic cylinder. Experimental results show, that under similar test conditions, the lubricating grease with viscosity VG100 is best suited for measuring reciprocating motion of the piston of pneumatic cylinder. The wear experiment showed that, in the Al2O3 film obtained at a preset voltage 40 V in the anodic process, the friction coefficient and hardness decreased by 55% and increased by 274% respectively, thus achieving a good tribology and wear resistance. Additionally, the amplitude variation in the friction force of the pneumatic cylinder wall that received the anodizing treatment was substantially reduced. Additionally, the stick-slip motion of the pneumatic cylinder during low-speed motion was substantially improved.

Taste bud-derived BDNF maintains innervation of a subset of TrkB-expressing gustatory nerve fibers.

Science.gov (United States)

Tang, Tao; Rios-Pilier, Jennifer; Krimm, Robin

2017-07-01

Taste receptor cells transduce different types of taste stimuli and transmit this information to gustatory neurons that carry it to the brain. Taste receptor cells turn over continuously in adulthood, requiring constant new innervation from nerve fibers. Therefore, the maintenance of innervation to taste buds is an active process mediated by many factors, including brain-derived neurotrophic factor (BDNF). Specifically, 40% of taste bud innervation is lost when Bdnf is removed during adulthood. Here we speculated that not all gustatory nerve fibers express the BDNF receptor, TrkB, resulting in subsets of neurons that vary in their response to BDNF. However, it is also possible that the partial loss of innervation occurred because the Bdnf gene was not effectively removed. To test these possibilities, we first determined that not all gustatory nerve fibers express the TrkB receptor in adult mice. We then verified the efficiency of Bdnf removal specifically in taste buds of K14-CreER:Bdnf mice and found that Bdnf expression was reduced to 1%, indicating efficient Bdnf gene recombination. BDNF removal resulted in a 55% loss of TrkB-expressing nerve fibers, which was greater than the loss of P2X3-positive fibers (39%), likely because taste buds were innervated by P2X3+/TrkB- fibers that were unaffected by BDNF removal. We conclude that gustatory innervation consists of both TrkB-positive and TrkB-negative taste fibers and that BDNF is specifically important for maintaining TrkB-positive innervation to taste buds. In addition, although taste bud size was not affected by inducible Bdnf removal, the expression of the γ subunit of the ENaC channel was reduced. So, BDNF may regulate expression of some molecular components of taste transduction pathways. Copyright © 2017. Published by Elsevier Inc.

48 CFR 52.247-66 - Returnable Cylinders.

Science.gov (United States)

2010-10-01

... Cylinders (MAY 1994) (a) Cylinder, referred to in this clause, is a pressure vessel designed for pressures... clause. (c) For each cylinder lost or damaged beyond repair while in the Government's possession, the... associated replacement values.] These cylinders shall become Government property. (d) If any lost cylinder is...

Synaptic Plasticity in Cardiac Innervation and Its Potential Role in Atrial Fibrillation

Directory of Open Access Journals (Sweden)

Jesse L. Ashton

2018-03-01

Full Text Available Synaptic plasticity is defined as the ability of synapses to change their strength of transmission. Plasticity of synaptic connections in the brain is a major focus of neuroscience research, as it is the primary mechanism underpinning learning and memory. Beyond the brain however, plasticity in peripheral neurons is less well understood, particularly in the neurons innervating the heart. The atria receive rich innervation from the autonomic branch of the peripheral nervous system. Sympathetic neurons are clustered in stellate and cervical ganglia alongside the spinal cord and extend fibers to the heart directly innervating the myocardium. These neurons are major drivers of hyperactive sympathetic activity observed in heart disease, ventricular arrhythmias, and sudden cardiac death. Both pre- and postsynaptic changes have been observed to occur at synapses formed by sympathetic ganglion neurons, suggesting that plasticity at sympathetic neuro-cardiac synapses is a major contributor to arrhythmias. Less is known about the plasticity in parasympathetic neurons located in clusters on the heart surface. These neuronal clusters, termed ganglionated plexi, or “little brains,” can independently modulate neural control of the heart and stimulation that enhances their excitability can induce arrhythmia such as atrial fibrillation. The ability of these neurons to alter parasympathetic activity suggests that plasticity may indeed occur at the synapses formed on and by ganglionated plexi neurons. Such changes may not only fine-tune autonomic innervation of the heart, but could also be a source of maladaptive plasticity during atrial fibrillation.

Flow over an inline oscillating circular cylinder in the wake of a stationary circular cylinder

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yang; Zhu, Keqiang, E-mail: zhukeqiang@nbu.edu.cn [Faculty of Maritime and Transportation, Ningbo University, Ningbo 315211 (China)

2017-02-15

Flow interference between an upstream stationary cylinder and an inline oscillating cylinder is studied with the lattice Boltzmann method. With a fixed Reynolds number Re  = 100 and pitch ratio L / D  = 4, the effects of oscillation amplitude A / D  = [0.25, 1] and frequency f {sub e}/ f {sub s} = [0.5, 2] are investigated. The wake response state is categorized into lock-in and non-lock-in. The lock-in zone in the bifurcation diagram of amplitude versus frequency is discontinuous. Response states of upstream and downstream wakes are similar under the conditions of small amplitude or low frequency. However, with large oscillating parameters, the two wakes are prone to be in different states as the flow field becomes irregular. Two distinct flow regimes have been identified, i.e., single-cylinder and two-cylinder shedding regimes. The presence of single-cylinder shedding regime is attributed to the low shedding frequency of the downstream cylinder at large amplitude. Hydrodynamic forces of the oscillating tandem system are discussed. The results reveal that forces on the two cylinders behave differently and that the absence of vortices in the gap flow significantly reduces the forces exerting on the tandem system. (paper)

Innervation of the cow's inner ear derived from micro-computed tomography

Science.gov (United States)

Costeur, Loic; Mennecart, Bastien; Khimchenko, Anna; Müller, Bert; Schulz, Georg

2017-09-01

The innervation of the inner ear has been thoroughly investigated in humans and in some animal models such as the guinea pig, the rabbit, the cat, the dog, the rat, the pig and some monkeys. Ruminant inner ears are still poorly known and their innervation was never investigated despite its potential interest in phylogenetic reconstructions. Following earlier works on the ontogeny of the cow's ear, we expand our understanding of this structure by reconstructing the fine innervation pattern of the inner ear of the cow in two ontogenetic stages, at 7 months gestation and at an adult age. Since we work on dry skeletal specimens, only the endocast of the innervation inside the petrosal bone was reconstructed up to the internal acoustic meatus. The paths of the facial and vestibulocochlear nerves could be reconstructed together with that of the spiral ganglion canal. The nerves have a very fibrous pattern. The bony cavities of the ampular and utricular branches of the vestibulocochlear nerve could also be reconstructed. Our observations confirm that not all bony structures are present in foetal stages since the branch of cranial nerve VII is not visible on the foetus but very broad on the adult stage. The fibrous pattern within the modiolus connecting the spiral canal to the cochlear nerve is also less dense than in the adult stage. The shape of the branch of cranial nerve VII is very broad in the cow ending in a large hiatus Fallopii; this, together with the above-mentioned particularities, could constitute relevant observations for phylogenetical purposes when more data will be made available.

Innervation and immunohistochemical characteristics of epididymis in Alpaca camelid (Vicugna pacos

Directory of Open Access Journals (Sweden)

Giovanna Liguori

2013-03-01

Full Text Available Alpacas (Vicugna pacos are domesticated camelids indigenous to south America and recently also bred in Europe and Italy for their high quality wool. There is little data available regarding the innervation of the male reproductive tract of this species. In the present study, the distribution of protein gene product 9.5 (PGP 9.5, neuropeptide Y (NPY, tyrosine hydroxilase (TH, calcitonin gene related peptide (CGRP and substance P (SP was analyzed in the epididymis by using immunohistochemical methods. Specimens of the caput, corpus and cauda epididymis were fixed in Bouin’s fluid and processed for immunohistochemistry analysis with primary antibodies against PGP 9.5, NPY, TH, CGRP and SP. Immunopositivity to PGP 9.5 and TH and NPY was observed in nerve fibre bundles and in single nerve fibres contained into the peritubular connective tissue. Many TH and NPY immunopositive cells were found to innervate blood vessels. Rare CGRP and SP immunopositive nerves were observed. Several PGP 9,5 and NPY immunopositive epithelial cells were observed in the caput epididymis. The results of the present study suggest a role for the innervations in modulate reproductive functions in the alpaca epididymis.

Swap your propane cylinder with SWOP

International Nuclear Information System (INIS)

Anon.

1997-01-01

A very successful propane cylinder exchange program operated by South Western Ontario Propane (SWOP) Inc., was described. The company specializes in propane cylinder exchange and in the refurbishing and marketing of top quality domestic and commercial propane cylinders. The company, currently operating out of Bradford, Ontario, was started in 1991. It employs a staff of 25 in peak season. It has some 200 exchange outlets throughout Ontario and has accepted outdated tanks from as far west as Manitoba and as far east as Quebec. A typical transaction involves bringing an empty cylinder to the nearest SWOP location and exchanging it for a full SWOP cylinder. SWOP does about 50,000 to 60,000 exchanges a year. For the consumer, the program is said to be cheaper, safer and more convenient than getting refills. As far as dealers are concerned operating a SWOP exchange outlet can add extra profits, attract new customers, and build additional consumer loyalty without the need for extra staff or additional indoor space. SWOP delivers full cylinders to exchange outlets on a weekly basis when it also picks up the empty cylinders. At dealer locations, the cylinders (full or empty) are stored in company -designed vandal-proof metal cages. Major expansion of the network of outlets and the cylinder refurbishing and refilling facilities are planned for 1998

Expression of Sex Steroid Hormone Receptors in Vagal Motor Neurons Innervating the Trachea and Esophagus in Mouse

International Nuclear Information System (INIS)

Mukudai, Shigeyuki; Ichi Matsuda, Ken; Bando, Hideki; Takanami, Keiko; Nishio, Takeshi; Sugiyama, Yoichiro; Hisa, Yasuo; Kawata, Mitsuhiro

2016-01-01

The medullary vagal motor nuclei, the nucleus ambiguus (NA) and dorsal motor nucleus of the vagus (DMV), innervate the respiratory and gastrointestinal tracts. We conducted immunohistochemical analysis of expression of the androgen receptor (AR) and estrogen receptor α (ERα), in relation to innervation of the trachea and esophagus via vagal motor nuclei in mice. AR and ERα were expressed in the rostral NA and in part of the DMV. Tracing experiments using cholera toxin B subunit demonstrated that neurons of vagal motor nuclei that innervate the trachea and esophagus express AR and ERα. There was no difference in expression of sex steroid hormone receptors between trachea- and esophagus-innervating neurons. These results suggest that sex steroid hormones may act on vagal motor nuclei via their receptors, thereby regulating functions of the trachea and esophagus

Peribronchial innervation of the rat lung.

Science.gov (United States)

Artico, Marco; Bosco, Sandro; Bronzetti, Elena; Felici, Laura M; Pelusi, Giuseppe; Lo Vasco, Vincenza Rita; Vitale, Marco

2004-10-01

Mammalian peribronchial tissue is supplied by several peptide-containing nerve fibers. Although it is well established that different neuropeptides exert significant effects on bronchial and vascular tone in the lungs, the role played by some neuromediators on the general regulation, differentiation and release of locally active substances is still controversial. We studied the innervation of rat peribronchial tissue by immunohistochemical techniques. The immunoperoxidase method with nickel amplification was applied to detect the distribution of nerve fibers using antibodies against the general neuronal marker PGP 9.5 (neuron-specific cytoplasmic protein), while the cholinacetyltransferase immunoreactivity was studied by immunohistochemistry. A slight immunoreactivity for NT receptors is observed in lung bronchial epithelium. There is increasing evidence that NTs may act with a paracrine mechanism regulating functional activity of neuronal and non-neuronal structures. A specific immunoreactivity for NTs and NT receptors was also demonstrated within different layers of large, medium and small sized intrapulmonary arteries and veins, according to a recent study of our group. Moreover our data describe the expression of NTs and NT receptors in lymphoid aggregates of the lung (BALT) in which both lymphocytes and macrophages express TrkA receptor and synthesize NTs. Our results show the presence of an extensive network of innervation in the rat peribronchial tissue, confirming a morphological basis for a possible neural modulation of the respiratory mucosa and the physiological/pathophysiological mechanisms of the lung.

Fire testing of bare uranium hexafluoride cylinders

Energy Technology Data Exchange (ETDEWEB)

Pryor, W.A. [PAI Corp., Oak Rige, TN (United States)

1991-12-31

In 1965, the Oak Ridge Gaseous Diffusion Plant (ORGDP), now the K-25 Site, conducted a series of tests in which bare cylinders of uranium hexafluoride (UF{sub 6}) were exposed to engulfing oil fires for the US Atomic Energy Commission (AEC), now the US Department of Energy (DOE). The tests are described and the results, conclusions, and observations are presented. Two each of the following types of cylinders were tested: 3.5-in.-diam {times} 7.5-in.-long cylinders of Monel (Harshaw), 5.0-in.-diam {times} 30-in.-long cylinders of Monel, and 8-in.-diam {times} 48-in.-long cylinders of nickel. The cylinders were filled approximately to the standard UF{sub 6} fill limits of 5, 55, and 250 lb, respectively, with a U-235 content of 0.22%. The 5-in.- and 8-in.-diam cylinders were tested individually with and without their metal valve covers. For the 3.5-in.-diam Harshaw cylinders and the 5.0-in.-diam cylinder without a valve cover the valves failed and UF{sub 6} was released. The remaining cylinders ruptured explosively in time intervals ranging from about 8.5 to 11 min.

Fire testing of bare uranium hexafluoride cylinders

Energy Technology Data Exchange (ETDEWEB)

Pryor, W.A. [PAI Corp., Oak Ridge, TN (United States)

1991-12-31

In 1965, the Oak Ridge Gaseous Diffusion Plant (ORGDP), now the K-25 Site, conducted a series of tests in which bare cylinders of uranium hexafluoride (UF{sub 6}) were exposed to engulfing oil fires for the US Atomic Energy Commission (AEC), now the US Department of Energy (DOE). The tests are described and the results, conclusions, and observations are presented. Two each of the following types of cylinders were tested: 3.5-in.-diam {times} 7.5-in.-long cylinders of Monel (Harshaw), 5.0-in.-diam {times} x 30-in.-long cylinders of Monel, and 8-in.-diam {times} 48-in.-long cylinders of nickel. The cylinders were filled approximately to the standard UF{sub 6} fill limits of 5, 55, and 250 lb, respectively, with a U-235 content of 0.22%. The 5-in.- and 8-in.-diam cylinders were tested individually with and without their metal valve covers. For the 3.5-in.-diam Harshaw cylinders and the 5.0-in.-diam cylinder without a valve cover, the valves failed and UF{sub 6} was released. The remaining 6 cylinders ruptured explosively in time intervals ranging from about 8.5 to 11 min.

Flow past a rotating cylinder

Science.gov (United States)

Mittal, Sanjay; Kumar, Bhaskar

2003-02-01

Flow past a spinning circular cylinder placed in a uniform stream is investigated via two-dimensional computations. A stabilized finite element method is utilized to solve the incompressible Navier Stokes equations in the primitive variables formulation. The Reynolds number based on the cylinder diameter and free-stream speed of the flow is 200. The non-dimensional rotation rate, [alpha] (ratio of the surface speed and freestream speed), is varied between 0 and 5. The time integration of the flow equations is carried out for very large dimensionless time. Vortex shedding is observed for [alpha] cylinder. The results from the stability analysis for the rotating cylinder are in very good agreement with those from direct numerical simulations. For large rotation rates, very large lift coefficients can be obtained via the Magnus effect. However, the power requirement for rotating the cylinder increases rapidly with rotation rate.

Sensory innervation of the dorsal longitudinal ligament and the meninges in the lumbar spine of the dog.

Science.gov (United States)

Waber-Wenger, Barbara; Forterre, Franck; Kuehni-Boghenbor, Kathrin; Danuser, Renzo; Stein, Jens Volker; Stoffel, Michael Hubert

2014-10-01

Although intervertebral disc herniation is a well-known disease in dogs, pain management for this condition has remained a challenge. The goal of the present study is to address the lack of information regarding the innervation of anatomical structures within the canine vertebral canal. Immunolabeling was performed with antibodies against protein gene product 9.5, Tuj-1 (neuron-specific class III β-tubulin), calcitonin gene-related peptide, and neuropeptide Y in combination with the lectin from Lycopersicon esculentum as a marker for blood vessels. Staining was indicative of both sensory and sympathetic fibers. Innervation density was the highest in lateral areas, intermediate in dorsal areas, and the lowest in ventral areas. In the dorsal longitudinal ligament (DLL), the highest innervation density was observed in the lateral regions. Innervation was lower at mid-vertebral levels than at intervertebral levels. The presence of sensory and sympathetic fibers in the canine dura and DLL suggests that pain may originate from both these structures. Due to these regional differences in sensory innervation patterns, trauma to intervertebral DLL and lateral dura is expected to be particularly painful. The results ought to provide a better basis for the assessment of medicinal and surgical procedures.

Associations between xerostomia, histopathological alterations, and autonomic innervation of labial salivary glands in men in late midlife

DEFF Research Database (Denmark)

Sørensen, Christiane Elisabeth; Larsen, Jytte Overgaard; Reibel, Jesper

2014-01-01

connective tissue. Acinar atrophy and fibrosis were negatively correlated with the parenchymal innervation and positively related to diffuse inflammation. CONCLUSIONS: The results from the present study indicate that aspects of the autonomic innervation of labial salivary glands may play a role...

Innervating sympathetic neurons regulate heart size and the timing of cardiomyocyte cell cycle withdrawal.

Science.gov (United States)

Kreipke, R E; Birren, S J

2015-12-01

Sympathetic drive to the heart is a key modulator of cardiac function and interactions between heart tissue and innervating sympathetic fibres are established early in development. Significant innervation takes place during postnatal heart development, a period when cardiomyocytes undergo a rapid transition from proliferative to hypertrophic growth. The question of whether these innervating sympathetic fibres play a role in regulating the modes of cardiomyocyte growth was investigated using 6-hydroxydopamine (6-OHDA) to abolish early sympathetic innervation of the heart. Postnatal chemical sympathectomy resulted in rats with smaller hearts, indicating that heart growth is regulated by innervating sympathetic fibres during the postnatal period. In vitro experiments showed that sympathetic interactions resulted in delays in markers of cardiomyocyte maturation, suggesting that changes in the timing of the transition from hyperplastic to hypertrophic growth of cardiomyocytes could underlie changes in heart size in the sympathectomized animals. There was also an increase in the expression of Meis1, which has been linked to cardiomyocyte cell cycle withdrawal, suggesting that sympathetic signalling suppresses cell cycle withdrawal. This signalling involves β-adrenergic activation, which was necessary for sympathetic regulation of cardiomyocyte proliferation and hypertrophy. The effect of β-adrenergic signalling on cardiomyocyte hypertrophy underwent a developmental transition. While young postnatal cardiomyocytes responded to isoproterenol (isoprenaline) with a decrease in cell size, mature cardiomyocytes showed an increase in cell size in response to the drug. Together, these results suggest that early sympathetic effects on proliferation modulate a key transition between proliferative and hypertrophic growth of the heart and contribute to the sympathetic regulation of adult heart size. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

Sub-wavelength resonances in polygonal metamaterial cylinders

DEFF Research Database (Denmark)

Arslanagic, Samel; Breinbjerg, Olav

2008-01-01

It has been shown that the sub-wavelength resonances of circular MTM cylinders also occur for polygonal MTM cylinders. This is the case for lossless and non-dispersive cylinders as well as lossy and dispersive cylinders. The sub-wavelength resonances are thus not limited to structures of canonical...

UF{sub 6} cylinder inspections at PGDP

Energy Technology Data Exchange (ETDEWEB)

Lamb, G.W.; Whinnery, W.N. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

1991-12-31

Routine inspections of all UF{sub 6} cylinders at the Paducah Gaseous Diffusion Plant have been mandated by the Department of Energy. A specific UF{sub 6} cylinder inspection procedure for what items to inspect and training for the operators prior to inspection duty are described. The layout of the cylinder yards and the forms used in the inspections are shown. The large number of cylinders (>30,000) to inspect and the schedule for completion on the mandated time table are discussed. Results of the inspections and the actions to correct the deficiencies are explained. Future inspections and movement of cylinders for relocation of certain cylinder yards are defined.

[Efferent innervation of the arteries of human leptomeninx in arterial hypertension].

Science.gov (United States)

Chertok, V M; Kotsiuba, A E; Babich, E V

2009-01-01

Structure of the efferent nerve plexuses (adrenergic, acetylcholinestherase- and cholinacetyltranspherase-positive, NO-dependent), was studied in the arteries of human leptomeninx with different diameters. Material was obtained from the corpses of the healthy people and of the patients with initial stages of arterial hypertension (AH). It was shown that the concentrations of cholinergic and adrenergic nerve fibers and varicosities in axon terminal part, innervating the arteries with the diameters ranging from 450 till 100 microm, were not significantly different. In these arteries, NO-ergic plexuses were also detected. In patients with AH, regardless the arterial diameters, the significant increase (up to 15-20%) of adrenergic nerve fiber and varicosity concentrations was found. The changes in cholinergic nerve fiber concentration were found to depend on the vessel diameter: the significant decrease of these parameter was observed only in arteries with the diameter of 100-200 microm. No significant changes in nerve plexus concentration was noticed in the arteries with greater or smaller diameter. In NO-ergic neural conductors, the enzyme activity decreased only in the large arteries, and remained almost unchanged in the small vascular branches. The changes in the vasomotor innervation described in AH, are interpreted as a vasomotor innervation dysfunction of the leptomeninx arteries that may result in the hemodynamic disturbances.

Approximation by Cylinder Surfaces

DEFF Research Database (Denmark)

Randrup, Thomas

1997-01-01

We present a new method for approximation of a given surface by a cylinder surface. It is a constructive geometric method, leading to a monorail representation of the cylinder surface. By use of a weighted Gaussian image of the given surface, we determine a projection plane. In the orthogonal...

MRI-based 3D pelvic autonomous innervation: a first step towards image-guided pelvic surgery

Energy Technology Data Exchange (ETDEWEB)

Bertrand, M.M. [University Montpellier I, Laboratory of Experimental Anatomy Faculty of Medicine Montpellier-Nimes, Montpellier (France); Macri, F.; Beregi, J.P. [Nimes University Hospital, University Montpellier 1, Radiology Department, Nimes (France); Mazars, R.; Prudhomme, M. [University Montpellier I, Laboratory of Experimental Anatomy Faculty of Medicine Montpellier-Nimes, Montpellier (France); Nimes University Hospital, University Montpellier 1, Digestive Surgery Department, Nimes (France); Droupy, S. [Nimes University Hospital, University Montpellier 1, Urology-Andrology Department, Nimes (France)

2014-08-15

To analyse pelvic autonomous innervation with magnetic resonance imaging (MRI) in comparison with anatomical macroscopic dissection on cadavers. Pelvic MRI was performed in eight adult human cadavers (five men and three women) using a total of four sequences each: T1, T1 fat saturation, T2, diffusion weighed. Images were analysed with segmentation software in order to extract nervous tissue. Key height points of the pelvis autonomous innervation were located in every specimen. Standardised pelvis dissections were then performed. Distances between the same key points and the three anatomical references forming a coordinate system were measured on MRIs and dissections. Concordance (Lin's concordance correlation coefficient) between MRI and dissection was calculated. MRI acquisition allowed an adequate visualization of the autonomous innervation. Comparison between 3D MRI images and dissection showed concordant pictures. The statistical analysis showed a mean difference of less than 1 cm between MRI and dissection measures and a correct concordance correlation coefficient on at least two coordinates for each point. Our acquisition and post-processing method demonstrated that MRI is suitable for detection of autonomous pelvic innervations and can offer a preoperative nerve cartography. (orig.)

Unilateral variant motor innervations of flexure muscles of arm

Directory of Open Access Journals (Sweden)

A S Yogesh

2010-01-01

Full Text Available The musculocutaneous nerve usually branches out from the lateral cord of brachial plexus. It innervates the corcobrachialis, biceps brachii and brachialis muscles and continues as the lateral cutaneous nerve of forearm without exhibiting any communication with the median nerve or any other nerve. We report unilateral variation in motor innervations of the left arm in a 58-year-old male cadaver. The musculocutaneous nerve was found to be absent. A muscular branch of the median nerve was supplying the coracobrachialis muscle. In the middle of arm, the median nerve was found to be branching out, bifurcating and supplying the long and short head of biceps. The median nerve was found to be giving a separate branch, which supplied the brachialis muscle and continued as the lateral cutaneous nerve of forearm. The right sided structures were found to be normal. Surgeons should keep such variations in mind while performing arm surgeries.

Theoretical and experimental stress analyses of ORNL thin-shell cylinder-to-cylinder model 2

International Nuclear Information System (INIS)

Gwaltney, R.C.; Bolt, S.E.; Bryson, J.W.

1975-10-01

Model 2 in a series of four thin-shell cylinder-to-cylinder models was tested, and the experimentally determined elastic stress distributions were compared with theoretical predictions obtained from a thin-shell finite-element analysis. Both the cylinder and the nozzle of model 2 had outside diameters of 10 in., giving a d 0 /D 0 ratio of 1.0, and both had outside diameter/thickness ratios of 100. Sixteen separate loading cases in which one end of the cylinder was rigidly held were analyzed. An internal pressure loading, three mutually perpendicular force components, and three mutually perpendicular moment components were individually applied at the free end of the cylinder and at the end of the nozzle. In addition to these 13 loadings, 3 additional loads were applied to the nozzle (in-plane bending moment, out-of-plane bending moment, and axial force) with the free end of the cylinder restrained. The experimental stress distributions for each of the 16 loadings were obtained using 152 three-gage strain rosettes located on the inner and outer surfaces. All the 16 loading cases were also analyzed theoretically using a finite-element shell analysis. The analysis used flat-plate elements and considered five degrees of freedom per node in the final assembled equations. The comparisons between theory and experiment show reasonably good general agreement, and it is felt that the analysis would be satisfactory for most engineering purposes. (auth)

Afferent Innervation, Muscle Spindles, and Contractures Following Neonatal Brachial Plexus Injury in a Mouse Model.

Science.gov (United States)

Nikolaou, Sia; Hu, Liangjun; Cornwall, Roger

2015-10-01

We used an established mouse model of elbow flexion contracture after neonatal brachial plexus injury (NBPI) to test the hypothesis that preservation of afferent innervation protects against contractures and is associated with preservation of muscle spindles and ErbB signaling. A model of preganglionic C5 through C7 NBPI was first tested in mice with fluorescent axons using confocal imaging to confirm preserved afferent innervation of spindles despite motor end plate denervation. Preganglionic and postganglionic injuries were then created in wild-type mice. Four weeks later, we assessed total and afferent denervation of the elbow flexors by musculocutaneous nerve immunohistochemistry. Biceps muscle volume and cross-sectional area were measured by micro computed tomography. An observer who was blinded to the study protocol measured elbow flexion contractures. Biceps spindle and muscle fiber morphology and ErbB signaling pathway activity were assessed histologically and immunohistochemically. Preganglionic and postganglionic injuries caused similar total denervation and biceps muscle atrophy. However, after preganglionic injuries, afferent innervation was partially preserved and elbow flexion contractures were significantly less severe. Spindles degenerated after postganglionic injury but were preserved after preganglionic injury. ErbB signaling was inactivated in denervated spindles after postganglionic injury but ErbB signaling activity was preserved in spindles after preganglionic injury with retained afferent innervation. Preganglionic and postganglionic injuries were associated with upregulation of ErbB signaling in extrafusal muscle fibers. Contractures after NBPI are associated with muscle spindle degeneration and loss of spindle ErbB signaling activity. Preservation of afferent innervation maintained spindle development and ErbB signaling activity, and protected against contractures. Pharmacologic modulation of ErbB signaling, which is being investigated as a

Pressure cylinders under fire condition

Directory of Open Access Journals (Sweden)

Jan Hora

2016-03-01

Full Text Available The presence of pressure cylinders under fire conditions significantly increases the risk rate for the intervening persons. It is considerably problematic to predict the pressure cylinders behaviour during heat exposition, its destruction progress and possible following explosion of the produced air–gas mixture because pressure cylinders and its environment generate a highly complicated dynamic system during an uncontrolled destruction. The large scale tests carried out by the Pilsen Fire and Rescue Department and the Rapid Response Unit of the Czech Republic Police in October 2012 and in May 2014 in the Military area Brdy and in the area of the former Lachema factory in Kaznějov had several objectives, namely, to record, qualify and quantify some of the aspects of an uncontrolled heat destruction procedure of an exposed pressure cylinder in an enclosed space and to qualify and describe the process of a controlled destruction of a pressure cylinder by shooting through it including basic tactical concepts. The article describes the experiments that were carried out.

Fire exposure of empty 30B cylinders

Energy Technology Data Exchange (ETDEWEB)

Ziehlke, K.T. [MJB Technical Associates, Inc., Knoxville, TN (United States)

1991-12-31

Cylinders for UF{sub 6} handling, transport, and storage are designed and built as unfired pressure vessels under ASME Boiler and Pressure Vessel Code criteria and standards. They are normally filled and emptied while UF{sub 6} is in its liquid phase. Transport cylinders such as the Model 30B are designed for service at 200 psi and 250{degrees}F, to sustain the process conditions which prevail during filling or emptying operations. While in transport, however, at ambient temperature the UF{sub 6} is solid, and the cylinder interior is well below atmospheric pressure. When the cylinders contain isotopically enriched product (above 1.0 percent U-235), they are transported in protective overpacks which function to guard the cylinders and their contents against thermal or mechanical damage in the event of possible transport accidents. Two bare Model 30B cylinders were accidentally exposed to a storage warehouse fire in which a considerable amount of damage was sustained by stored materials and the building structure, as well as by the cylinder valves and valve protectors. The cylinders were about six years old, and had been cleaned, inspected, hydrotested, and re-certified for service, but were still empty at the time of the fire. The privately-owned cylinders were transferred to DOE for testing and evaluation of the fire damage.

Multiple Cylinder Free-Piston Stirling Machinery

Science.gov (United States)

Berchowitz, David M.; Kwon, Yong-Rak

In order to improve the specific power of piston-cylinder type machinery, there is a point in capacity or power where an advantage accrues with increasing number of piston-cylinder assemblies. In the case of Stirling machinery where primary energy is transferred across the casing wall of the machine, this consideration is even more important. This is due primarily to the difference in scaling of basic power and the required heat transfer. Heat transfer is found to be progressively limited as the size of the machine increases. Multiple cylinder machines tend to preserve the surface area to volume ratio at more favorable levels. In addition, the spring effect of the working gas in the so-called alpha configuration is often sufficient to provide a high frequency resonance point that improves the specific power. There are a number of possible multiple cylinder configurations. The simplest is an opposed pair of piston-displacer machines (beta configuration). A three-cylinder machine requires stepped pistons to obtain proper volume phase relationships. Four to six cylinder configurations are also possible. A small demonstrator inline four cylinder alpha machine has been built to demonstrate both cooling operation and power generation. Data from this machine verifies theoretical expectations and is used to extrapolate the performance of future machines. Vibration levels are discussed and it is argued that some multiple cylinder machines have no linear component to the casing vibration but may have a nutating couple. Example applications are discussed ranging from general purpose coolers, computer cooling, exhaust heat power extraction and some high power engines.

Natural convective heat transfer from square cylinder

Energy Technology Data Exchange (ETDEWEB)

Novomestský, Marcel, E-mail: marcel.novomestsky@fstroj.uniza.sk; Smatanová, Helena, E-mail: helena.smatanova@fstroj.uniza.sk; Kapjor, Andrej, E-mail: andrej.kapjor@fstroj.uniza.sk [University of Žilina, Faculty of Mechanical Engineering, Department of Power Engineering, Univerzitná 1, 010 26 Žilina (Slovakia)

2016-06-30

This article is concerned with natural convective heat transfer from square cylinder mounted on a plane adiabatic base, the cylinders having an exposed cylinder surface according to different horizontal angle. The cylinder receives heat from a radiating heater which results in a buoyant flow. There are many industrial applications, including refrigeration, ventilation and the cooling of electrical components, for which the present study may be applicable.

Investigation of breached depleted UF{sub 6} cylinders

Energy Technology Data Exchange (ETDEWEB)

DeVan, J.H. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)

1991-12-31

In June 1990, during a three-site inspection of cylinders being used for long-term storage of solid depleted UF{sub 6}, two 14-ton cylinders at Portsmouth, Ohio, were discovered with holes in the barrel section of the cylinders. An investigation team was immediately formed to determine the cause of the failures and their impact on future storage procedures and to recommend corrective actions. Subsequent investigation showed that the failures most probably resulted from mechanical damage that occurred at the time that the cylinders had been placed in the storage yard. In both cylinders evidence pointed to the impact of a lifting lug of an adjacent cylinder near the front stiffening ring, where deflection of the cylinder could occur only by tearing the cylinder. The impacts appear to have punctured the cylinders and thereby set up corrosion processes that greatly extended the openings in the wall and obliterated the original crack. Fortunately, the reaction products formed by this process were relatively protective and prevented any large-scale loss of uranium. The main factors that precipitated the failures were inadequate spacing between cylinders and deviations in the orientations of lifting lugs from their intended horizontal position. After reviewing the causes and effects of the failures, the team`s principal recommendation for remedial action concerned improved cylinder handling and inspection procedures. Design modifications and supplementary mechanical tests were also recommended to improve the cylinder containment integrity during the stacking operation.

Radiation levels on empty cylinders containing heel material

Energy Technology Data Exchange (ETDEWEB)

Shockley, C.W. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

1991-12-31

Empty UF{sub 6} cylinders containing heel material were found to emit radiation levels in excess of 200 mr/hr, the maximum amount stated in ORO-651. The radiation levels were as high as 335 mr/hr for thick wall (48X and 48Y) cylinders and 1050 mr/hr for thin wall (48G and 48H) cylinders. The high readings were found only on the bottom of the cylinders. These radiation levels exceeded the maximum levels established in DOT 49 CFR, Part 173.441 for shipment of cylinders. Holding periods of four weeks for thick-wall cylinders and ten weeks for thin-wall cylinders were established to allow the radiation levels to decay prior to shipment.

The role of Sema3–Npn-1 signaling during diaphragm innervation and muscle development

Science.gov (United States)

Huettl, Rosa-Eva; Hanuschick, Philipp; Amend, Anna-Lena; Alberton, Paolo; Aszodi, Attila; Huber, Andrea B.

2016-01-01

ABSTRACT Correct innervation of the main respiratory muscle in mammals, namely the thoracic diaphragm, is a crucial pre-requisite for the functionality of this muscle and the viability of the entire organism. Systemic impairment of Sema3A–Npn-1 (Npn-1 is also known as NRP1) signaling causes excessive branching of phrenic nerves in the diaphragm and into the central tendon region, where the majority of misguided axons innervate ectopic musculature. To elucidate whether these ectopic muscles are a result of misguidance of myoblast precursors due to the loss of Sema3A–Npn-1 signaling, we conditionally ablated Npn-1 in somatic motor neurons, which led to a similar phenotype of phrenic nerve defasciculation and, intriguingly, also formation of innervated ectopic muscles. We therefore hypothesize that ectopic myocyte fusion is caused by additional factors released by misprojecting growth cones. Slit2 and its Robo receptors are expressed by phrenic motor axons and migrating myoblasts, respectively, during innervation of the diaphragm. In vitro analyses revealed a chemoattractant effect of Slit2 on primary diaphragm myoblasts. Thus, we postulate that factors released by motor neuron growth cones have an influence on the migration properties of myoblasts during establishment of the diaphragm. PMID:27466379

Stress analysis of cylinder to cylinder intersections

International Nuclear Information System (INIS)

Revesz, Z.

1983-01-01

Cylinder to cylinder intersections have numerous applications in the power industry from different piping junctions to pressure vessel nozzles. A specific purpose computer program has been installed at the author's establishment for finite element analysis of such geometries. Some of the experiences are presented giving a short overview of the analysis of unreinforced man-holes, demonstrating how a more economical design has been verified by analysis. The program installed has linear-elastic and elasto-plastic capabilities. Further, it is prepared for heat transfer analysis with subsequent thermal stress computation. An efficient pre- and post-processor has also been installed and enhanced by the author. The software used is at its present stage capable for problem definition with input data such as outside/ inside diameters, length and number of subdivisions. Similarly simple is the load definition and the graphic representation of the full output. (author)

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.

Stabilization of flow past a rounded cylinder

Science.gov (United States)

Samtaney, Ravi; Zhang, Wei

2016-11-01

We perform global linear stability analysis on low-Re flow past a rounded cylinder. The cylinder corners are rounded with a radius R, normalized as R+ = R / D where D is the cylinder diameter, and its effect on the flow stability characteristics is investigated. We compute the critical Reynolds number (Recr) for the onset of first instability, and quantify the perturbation growth rate for the super-critical flows. It is found that the flow can be stabilized by partially rounding the cylinder. Compared with the square and circular cylinders, the partially rounded cylinder has a higher Recr , attaining a maximum at around R+ = 0 . 30 , and the perturbation growth rate of the super-critical flows is reduced for Re R+ -> 0 . 00), while only the near-wake backflow is crucial for circular-like cylinders (R+ -> 0 . 50). The stability analysis results are also verified with those of the direct simulations and very good agreement is achieved. Supported by the KAUST Office of Competitive Research Funds under Award No. URF/1/1394-01. The supercomputer Shaheen at KAUST was utilized for the simulations.

The Masticatory Contractile Load Induced Expression and Activation of Akt1/PKBα in Muscle Fibers at the Myotendinous Junction within Muscle-Tendon-Bone Unit

Directory of Open Access Journals (Sweden)

Yüksel Korkmaz

2010-01-01

Full Text Available The cell specific detection of enzyme activation in response to the physiological contractile load within muscle-tendon-bone unit is essential for understanding of the mechanical forces transmission from muscle cells via tendon to the bone. The hypothesis that the physiological mechanical loading regulates activation of Akt1/PKBα at Thr308 and at Ser473 in muscle fibers within muscle-tendon-bone unit was tested using quantitative immunohistochemistry, confocal double fluorescence analysis, and immunoblot analysis. In comparison to the staining intensities in peripheral regions of the muscle fibers, Akt1/PKBα was detected with a higher staining intensity in muscle fibers at the myotendinous junction (MTJ areas. In muscle fibers at the MTJ areas, Akt1/PKBα is dually phosphorylated at Thr308 and Ser473. The immunohistochemical results were confirmed by immunoblot analysis. We conclude that contractile load generated by masticatory muscles induces local domain-dependent expression of Akt1/PKBα as well as activation by dually phosphorylation at Thr308 and Ser473 in muscle fibers at the MTJ areas within muscle-tendon-bone unit.

Putaminal serotonergic innervation: monitoring dyskinesia risk in Parkinson disease.

Science.gov (United States)

Lee, Jee-Young; Seo, Seongho; Lee, Jae Sung; Kim, Han-Joon; Kim, Yu Kyeong; Jeon, Beom S

2015-09-08

To explore serotonergic innervation in the basal ganglia in relation to levodopa-induced dyskinesia in patients with Parkinson disease (PD). A total of 30 patients with PD without dementia or depression were divided into 3 matched groups (dyskinetic, nondyskinetic, and drug-naive) for this study. We acquired 2 PET scans and 3T MRI for each patient using [(11)C]-3-amino-4-(2-dimethylaminomethylphenylsulfanyl)-benzonitrile ((11)C-DASB) and N-(3-[(18)F]fluoropropyl)-2-carbomethoxy-3-(4-iodophenyl) nortropane ((18)F-FP-CIT). Then we analyzed binding potentials of the 2 radiotracers at basal ganglia structures and correlations with clinical variables. We observed no difference in (18)F-FP-CIT binding between dyskinetic and nondyskinetic patients, whereas there were differences in (11)C-DASB binding for the caudate and putamen. Binding potential ratios ((11)C-DASB/(18)F-FP-CIT) at the putamen, which indicate serotoninergic fiber innervation relative to dopaminergic fiber availability, were highest in the dyskinetic group, followed by the nondyskinetic and drug-naive PD groups. (11)C-DASB/(18)F-FP-CIT ratios at the putamen and pallidum correlated positively with Unified Parkinson's Disease Rating Scale (UPDRS) total scores and duration of PD, and pallidal binding ratio also correlated with the UPDRS motor scores. Ratios were not dependent on dopaminergic medication dosages for any of the regions studied. Relative serotonergic innervation of the putamen and pallidum increased with clinical PD progression and was highest in patients with established dyskinesia. The serotonin/dopamine transporter ratio might be a potential marker of disease progression and an indicator of risk for levodopa-induced dyskinesia in PD. A prospective evaluation is warranted in the future. © 2015 American Academy of Neurology.

Overseas shipments of 48Y cylinders

Energy Technology Data Exchange (ETDEWEB)

Tanaka, R.T.; Furlan, A.S. [Cameco Corp., Port Hope, Ontario (Canada)

1991-12-31

This paper describes experiences with two incidents of overseas shipments of uranium hexafluoride (UF{sub 6}) cylinders. The first incident involved nine empty UF{sub 6} cylinders in enclosed sea containers. Three UF{sub 6} cylinders broke free from their tie-downs and damaged and contaminated several sea containers. This paper describes briefly how decontamination was carried out. The second incident involved a shipment of 14 full UF{sub 6} cylinders. Although the incident did not cause an accident, the potential hazard was significant. The investigation of the cause of the near accident is recounted. Recommendations to alleviate future similar incidents for both cases are presented.

Testosterone supplementation restores vasopressin innervation in the senescent rat brain

NARCIS (Netherlands)

Goudsmit, E.; Fliers, E.; Swaab, D. F.

1988-01-01

The vasopressin (AVP) innervation in the male rat brain is decreased in senescence. This decrease is particularly pronounced in brain regions where AVP fiber density is dependent on plasma levels of sex steroids. Since plasma testosterone levels decrease progressively with age in the rat, the

Midbrain dopamine neurons associated with reward processing innervate the neurogenic subventricular zone.

Science.gov (United States)

Lennington, Jessica B; Pope, Sara; Goodheart, Anna E; Drozdowicz, Linda; Daniels, Stephen B; Salamone, John D; Conover, Joanne C

2011-09-14

Coordinated regulation of the adult neurogenic subventricular zone (SVZ) is accomplished by a myriad of intrinsic and extrinsic factors. The neurotransmitter dopamine is one regulatory molecule implicated in SVZ function. Nigrostriatal and ventral tegmental area (VTA) midbrain dopamine neurons innervate regions adjacent to the SVZ, and dopamine synapses are found on SVZ cells. Cell division within the SVZ is decreased in humans with Parkinson's disease and in animal models of Parkinson's disease following exposure to toxins that selectively remove nigrostriatal neurons, suggesting that dopamine is critical for SVZ function and nigrostriatal neurons are the main suppliers of SVZ dopamine. However, when we examined the aphakia mouse, which is deficient in nigrostriatal neurons, we found no detrimental effect to SVZ proliferation or organization. Instead, dopamine innervation of the SVZ tracked to neurons at the ventrolateral boundary of the VTA. This same dopaminergic neuron population also innervated the SVZ of control mice. Characterization of these neurons revealed expression of proteins indicative of VTA neurons. Furthermore, exposure to the neurotoxin MPTP depleted neurons in the ventrolateral VTA and resulted in decreased SVZ proliferation. Together, these results reveal that dopamine signaling in the SVZ originates from a population of midbrain neurons more typically associated with motivational and reward processing.

A methodology to identify the intake charge cylinder-to-cylinder distribution in turbocharged direct injection Diesel engines

Science.gov (United States)

Luján, José M.; Galindo, José; Serrano, José R.; Pla, Benjamín

2008-06-01

Exhaust gas recirculation (EGR) is currently the most important NOx emission control system. During the last few years the EGR rate has increased progressively as pollutant emission regulations have become more restrictive. High EGR rate levels have given the effect of the unsuitable EGR and air distribution between cylinders away, which causes undesirable engine behavior. In this sense, the study of the EGR distribution between cylinders achieves high importance. However, despite the fact that the EGR is continuously under study, not many studies have been undertaken to approach its distribution between cylinders. In concordance with the aspects outlined before, the aim of this paper is to propose a methodology that permits us to identify the EGR cylinder-to-cylinder dispersion in a commercial engine. In order to achieve this objective, experimental tests have been combined with both one-dimensional and three-dimensional fluid dynamic models.

Robust cylinder pressure estimation in heavy-duty diesel engines

NARCIS (Netherlands)

Kulah, S.; Forrai, A.; Rentmeester, F.; Donkers, T.; Willems, F.P.T.

2017-01-01

The robustness of a new single-cylinder pressure sensor concept is experimentally demonstrated on a six-cylinder heavy-duty diesel engine. Using a single-cylinder pressure sensor and a crank angle sensor, this single-cylinder pressure sensor concept estimates the in-cylinder pressure traces in the

Improvement of the Magnetic Shielding Effects by the Superposition of a Multi-Layered Ferromagnetic Cylinder over an HTS Cylinder: Relationship Between the Shielding Effects and the Layer Number of the Ferromagnetic Cylinder

International Nuclear Information System (INIS)

Yasui, K; Tarui, Y; Itoh, M

2006-01-01

The idealized magnetic shielded vessel can be realized by making use of a high-critical temperature superconductor (HTS). It is difficult for practical applications, however, to fabricate a shielding vessel that has a high value of the maximum shielded magnetic flux density B s0 . The present authors have improved the value of B s0 for the Bi-Pb-Sr-Ca-Cu-O (BPSCCO) cylinder used as the shielding vessel, by the superposition of a four-layered softiron cylinder over the BPSCCO cylinder, termed the four-layered superimposed cylinder. The B s4 value of 610 x 10 -4 T for the four-layered superimposed cylinder, is found to be about 4 times larger than that of a single-BPSCCO cylinder, and is theoretically analyzed by use of a new analysis method. The experimental values of the maximum shielded magnetic flux density B sn of n-layered superimposed cylinders are found to agree well with those of the theoretical analysis. Experimental results revealed several characteristics of the magnetic shielding within the n-layered superimposed cylinders. Also discussed is the new analysis method for the relationship between the n and B sn

Aerodynamic loading on a cylinder behind an airfoil

Energy Technology Data Exchange (ETDEWEB)

Zhang, H.J.; Huang, L.; Zhou, Y. [Hong Kong Polytechnic University, Department of Mechanical Engineering, Kowloon (Hong Kong)

2005-05-01

The interaction between the wake of a rotor blade and a downstream cylinder holds the key to the understanding and control of electronic cooling fan noise. In this paper, the aerodynamic characteristics of a circular cylinder are experimentally studied in the presence of an upstream NACA 4412 airfoil for the cylinder-diameter-based Reynolds numbers of Re{sub d}=2,100-20,000, and the airfoil chord-length-based Reynolds numbers of Re{sub c}=14,700-140,000. Lift and drag fluctuations on the cylinder, and the longitudinal velocity fluctuations of the flow behind the cylinder were measured simultaneously using a load cell and two hot wires, respectively. Data analysis shows that unsteady forces on the cylinder increase significantly in the presence of the airfoil wake. The dependence of the forces on two parameters is investigated, that is, the lateral distance (T) between the airfoil and the cylinder, and the Reynolds number. The forces decline quickly as Tincreases. For Re{sub c}<60,000, the vortices shed from the upstream airfoil make a major contribution to the unsteady forces on the cylinder compared to the vortex shedding from the cylinder itself. For Re{sub c}>60,000, no vortices are generated from the airfoil, and the fluctuating forces on the cylinder are caused by its own vortex shedding. (orig.)

Inner cylinder of the CMS vacuum tank.

CERN Multimedia

Patrice Loïez

2002-01-01

The vacuum tank of the CMS magnet system consists of inner and outer stainless-steel cylinders and houses the superconducting coil. The inner cylinder contains all the barrel sub-detectors, which it supports via a system of horizontal rails. The cylinder is pictured here in the vertical position on a yellow platform mounted on the ferris-wheel support structure. This will allow it to be pivoted and inserted into the outer cylinder already attached to the innermost ring of the barrel yoke.

UF{sub 6} pressure excursions during cylinder heating

Energy Technology Data Exchange (ETDEWEB)

Brown, P.G. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

1991-12-31

As liquid UF{sub 6} inside a cylinder changes from a liquid to a solid, it forms a porous solid which occupies approximately the same volume as that of the liquid before cooling. Simultaneously as the liquid cools, UF{sub 6} vapor in the cylinder ullage above the liquid desublimes on the upper region of the inner cylinder wall. This solid is a dense, glass-like material which can accumulate to a significant thickness. The thickness of the solid coating on the upper cylinder wall and directly behind the cylinder valve area will vary depending on the conditions during the cooling stage. The amount of time lapsed between UF{sub 6} solidification and UF{sub 6} liquefaction can also affect the UF{sub 6} coating. This is due to the daily ambient heat cycle causing the coating to sublime from the cylinder wall to cooler areas, thus decreasing the thickness. Structural weakening of the dense UF{sub 6} layer also occurs due to cylinder transport vibration and thermal expansion. During cylinder heating, the UF{sub 6} nearest the cylinder wall will liquefy first. As the solid coating behind the cylinder valve begins to liquefy, it results in increased pressure depending upon the available volume for expansion. At the Paducah Gaseous Diffusion Plant (PGDP) during the liquefaction of the UF{sub 6} in cylinders in the UF{sub 6} feed and sampling autoclaves, this pressure increase has resulted in the activation of the systems rupture discs which are rated at 100 pounds per square inch differential.

Innervation of taste buds revealed with Brainbow-labeling in mouse.

Science.gov (United States)

Zaidi, Faisal N; Cicchini, Vanessa; Kaufman, Daniel; Ko, Elizabeth; Ko, Abraham; Van Tassel, Heather; Whitehead, Mark C

2016-12-01

Nerve fibers that surround and innervate the taste bud were visualized with inherent fluorescence using Brainbow transgenic mice that were generated by mating the founder line L with nestin-cre mice. Multicolor fluorescence revealed perigemmal fibers as branched within the non-taste epithelium and ending in clusters of multiple rounded swellings surrounding the taste pore. Brainbow-labeling also revealed the morphology and branching pattern of single intragemmal fibers. These taste bud fibers frequently innervated both the peripheral bud, where immature gemmal cells are located, and the central bud, where mature, differentiated cells are located. The fibers typically bore preterminal and terminal swellings, growth cones with filopodia, swellings, and rounded retraction bulbs. These results establish an anatomical substrate for taste nerve fibers to contact and remodel among receptor cells at all stages of their differentiation, an interpretation that was supported by staining with GAP-43, a marker for growing fibers and growth cones. © 2016 Anatomical Society.

Numerical Study of Shock-Cylinder Banks Interactions

International Nuclear Information System (INIS)

Wang, S.P.; Anderson, M.H.; Oakley, J.G.; Bonazza, R.

2003-01-01

A numerical parametric study of shock-cylinder banks interactions is presented using a high resolution Euler solver. Staggered cylinder banks of five rows are chosen with the purpose of modeling IFE reactor cooling tube banks. The effect of the aspect ratio of the intercylinder pitch to the distance between successive cylinder rows on the vertical pressure forces acting on the cylinders with different geometries is investigated. Preliminary results show that the largest vertical force develops on the cylinders of the second or third row. This peak pressure force increases with decreasing values of the aspect ratio. It is shown that an increasing second force peak also appears on the successive rows, starting with the second one, with decreasing aspect ratio. It is also observed that the force on the last-row cylinders basically decreases to the level of that on the first row. The results are useful for the optimal design of the cooling tubes system of IFE reactors

Theoretical and experimental stress analyses of ORNL thin-shell cylinder-to-cylinder model 3

International Nuclear Information System (INIS)

Gwaltney, R.C.; Bolt, S.E.; Corum, J.M.; Bryson, J.W.

1975-06-01

The third in a series of four thin-shell cylinder-to-cylinder models was tested, and the experimentally determined elastic stress distributions were compared with theoretical predictions obtained from a thin-shell finite-element analysis. The models are idealized thin-shell structures consisting of two circular cylindrical shells that intersect at right angles. There are no transitions, reinforcements, or fillets in the junction region. This series of model tests serves two basic purposes: the experimental data provide design information directly applicable to nozzles in cylindrical vessels; and the idealized models provide test results for use in developing and evaluating theoretical analyses applicable to nozzles in cylindrical vessels and to thin piping tees. The cylinder of model 3 had a 10 in. OD and the nozzle had a 1.29 in. OD, giving a d 0 /D 0 ratio of 0.129. The OD/thickness ratios for the cylinder and the nozzle were 50 and 7.68 respectively. Thirteen separate loading cases were analyzed. In each, one end of the cylinder was rigidly held. In addition to an internal pressure loading, three mutually perpendicular force components and three mutually perpendicular moment components were individually applied at the free end of the cylinder and at the end of the nozzle. The experimental stress distributions for all the loadings were obtained using 158 three-gage strain rosettes located on the inner and outer surfaces. The loading cases were also analyzed theoretically using a finite-element shell analysis developed at the University of California, Berkeley. The analysis used flat-plate elements and considered five degrees of freedom per node in the final assembled equations. The comparisons between theory and experiment show reasonably good agreement for this model. (U.S.)

Theoretical and experimental stress analyses of ORNL thin-shell cylinder-to-cylinder model 4

International Nuclear Information System (INIS)

Gwaltney, R.C.; Bolt, S.E.; Bryson, J.W.

1975-06-01

The last in a series of four thin-shell cylinder-to-cylinder models was tested, and the experimentally determined elastic stress distributions were compared with theoretical predictions obtained from a thin-shell finite-element analysis. The models in the series are idealized thin-shell structures consisting of two circular cylindrical shells that intersect at right angles. There are no transitions, reinforcements, or fillets in the junction region. This series of model tests serves two basic purposes: (1) the experimental data provide design information directly applicable to nozzles in cylindrical vessels, and (2) the idealized models provide test results for use in developing and evaluating theoretical analyses applicable to nozzles in cylindrical vessels and to thin piping tees. The cylinder of model 4 had an outside diameter of 10 in., and the nozzle had an outside diameter of 1.29 in., giving a d 0 /D 0 ratio of 0.129. The OD/thickness ratios were 50 and 20.2 for the cylinder and nozzle respectively. Thirteen separate loading cases were analyzed. For each loading condition one end of the cylinder was rigidly held. In addition to an internal pressure loading, three mutually perpendicular force components and three mutually perpendicular moment components were individually applied at the free end of the cylinder and at the end of the nozzle. The experimental stress distributions for each of the 13 loadings were obtained using 157 three-gage strain rosettes located on the inner and outer surfaces. Each of the 13 loading cases was also analyzed theoretically using a finite-element shell analysis developed at the University of California, Berkeley. The analysis used flat-plate elements and considered five degrees of freedom per node in the final assembled equations. The comparisons between theory and experiment show reasonably good agreement for this model. (U.S.)

Heterogeneous sensory innervation and extensive intrabulbar connections of olfactory necklace glomeruli.

Directory of Open Access Journals (Sweden)

Renee E Cockerham

Full Text Available The mammalian nose employs several olfactory subsystems to recognize and transduce diverse chemosensory stimuli. These subsystems differ in their anatomical position within the nasal cavity, their targets in the olfactory forebrain, and the transduction mechanisms they employ. Here we report that they can also differ in the strategies they use for stimulus coding. Necklace glomeruli are the sole main olfactory bulb (MOB targets of an olfactory sensory neuron (OSN subpopulation distinguished by its expression of the receptor guanylyl cyclase GC-D and the phosphodiesterase PDE2, and by its chemosensitivity to the natriuretic peptides uroguanylin and guanylin and the gas CO(2. In stark contrast to the homogeneous sensory innervation of canonical MOB glomeruli from OSNs expressing the same odorant receptor (OR, we find that each necklace glomerulus of the mouse receives heterogeneous innervation from at least two distinct sensory neuron populations: one expressing GC-D and PDE2, the other expressing olfactory marker protein. In the main olfactory system it is thought that odor identity is encoded by a combinatorial strategy and represented in the MOB by a pattern of glomerular activation. This combinatorial coding scheme requires functionally homogeneous sensory inputs to individual glomeruli by OSNs expressing the same OR and displaying uniform stimulus selectivity; thus, activity in each glomerulus reflects the stimulation of a single OSN type. The heterogeneous sensory innervation of individual necklace glomeruli by multiple, functionally distinct, OSN subtypes precludes a similar combinatorial coding strategy in this olfactory subsystem.

Cracking investigation of Monju emergency generator C unit cylinder liner. Cylinder liner soundness confirmation by a fall cause of the materials strength of the cylinder liner and the supersonic wave speed

International Nuclear Information System (INIS)

Kobayashi, Takanori; Sakon, Miyoji; Takada, Osamu; Hatori, Masakazu; Sakamoto, Tsutomu; Sato, Toshiyuki; Kazama, Akihito; Ishizawa, Yoshihiro; Igawa, Katsuhisa; Nakae, Hideo

2012-02-01

I confirmed a leak of the effluent gas from cylinder part during a load examination after the check of the emergency generator C unit on December 28, 2010 of the facilities check average and confirmed crack in No.8 cylinder liner part. As a result, because it was not performed oil pressure management properly without attaching an oil pressure gauge when I removed cylinder liner about the cause, crack occurred by having been able to write excessive stress for the cylinder liner and reached damage. By a process of this investigation, a fall of the materials strength of some cylinder liner was confirmed, but because a lead ingredient got mixed with materials by a casting process at the time of the production of the cylinder liner, as for this, Widmannstaetten graphite occurred, and it became clear that materials strength fell. In addition, I performed inspection by the supersonic wave velocity measurement as technique to distinguish this Widmannstaetten graphite easily and confirmed that I was effective. Because this report was the knowledge that there were little inspection contents which modified soundness confirmation technique of the cylinder liner with the possibility of materials strength fall of the cylinder liner by the Widmannstaetten graphite outbreak and the mixture of lead for a report example in the field of cast iron, I gathered it in this report. (author)

Soft Ultrathin Electronics Innervated Adaptive Fully Soft Robots.

Science.gov (United States)

Wang, Chengjun; Sim, Kyoseung; Chen, Jin; Kim, Hojin; Rao, Zhoulyu; Li, Yuhang; Chen, Weiqiu; Song, Jizhou; Verduzco, Rafael; Yu, Cunjiang

2018-03-01

Soft robots outperform the conventional hard robots on significantly enhanced safety, adaptability, and complex motions. The development of fully soft robots, especially fully from smart soft materials to mimic soft animals, is still nascent. In addition, to date, existing soft robots cannot adapt themselves to the surrounding environment, i.e., sensing and adaptive motion or response, like animals. Here, compliant ultrathin sensing and actuating electronics innervated fully soft robots that can sense the environment and perform soft bodied crawling adaptively, mimicking an inchworm, are reported. The soft robots are constructed with actuators of open-mesh shaped ultrathin deformable heaters, sensors of single-crystal Si optoelectronic photodetectors, and thermally responsive artificial muscle of carbon-black-doped liquid-crystal elastomer (LCE-CB) nanocomposite. The results demonstrate that adaptive crawling locomotion can be realized through the conjugation of sensing and actuation, where the sensors sense the environment and actuators respond correspondingly to control the locomotion autonomously through regulating the deformation of LCE-CB bimorphs and the locomotion of the robots. The strategy of innervating soft sensing and actuating electronics with artificial muscles paves the way for the development of smart autonomous soft robots. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Approximation of Surfaces by Cylinders

DEFF Research Database (Denmark)

Randrup, Thomas

1998-01-01

We present a new method for approximation of a given surface by a cylinder surface. It is a constructive geometric method, leading to a monorail representation of the cylinder surface. By use of a weighted Gaussian image of the given surface, we determine a projection plane. In the orthogonal...

Cholinergic innervation of human mesenteric lymphatic vessels.

Science.gov (United States)

D'Andrea, V; Bianchi, E; Taurone, S; Mignini, F; Cavallotti, C; Artico, M

2013-11-01

The cholinergic neurotransmission within the human mesenteric lymphatic vessels has been poorly studied. Therefore, our aim is to analyse the cholinergic nerve fibres of lymphatic vessels using the traditional enzymatic techniques of staining, plus the biochemical modifications of acetylcholinesterase (AChE) activity. Specimens obtained from human mesenteric lymphatic vessels were subjected to the following experimental procedures: 1) drawing, cutting and staining of tissues; 2) staining of total nerve fibres; 3) enzymatic staining of cholinergic nerve fibres; 4) homogenisation of tissues; 5) biochemical amount of proteins; 6) biochemical amount of AChE activity; 6) quantitative analysis of images; 7) statistical analysis of data. The mesenteric lymphatic vessels show many AChE positive nerve fibres around their wall with an almost plexiform distribution. The incubation time was performed at 1 h (partial activity) and 6 h (total activity). Moreover, biochemical dosage of the same enzymatic activity confirms the results obtained with morphological methods. The homogenates of the studied tissues contain strong AChE activity. In our study, the lymphatic vessels appeared to contain few cholinergic nerve fibres. Therefore, it is expected that perivascular nerve stimulation stimulates cholinergic nerves innervating the mesenteric arteries to release the neurotransmitter AChE, which activates muscarinic or nicotinic receptors to modulate adrenergic neurotransmission. These results strongly suggest, that perivascular cholinergic nerves have little or no effect on the adrenergic nerve function in mesenteric arteries. The cholinergic nerves innervating mesenteric arteries do not mediate direct vascular responses.

Distribution, Innervation, and Cellular Organization of Taste Buds in the Sea Catfish, Plotosus japonicus.

Science.gov (United States)

Nakamura, Tatsufumi; Matsuyama, Naoki; Kirino, Masato; Kasai, Masanori; Kiyohara, Sadao; Ikenaga, Takanori

2017-01-01

The gustatory system of the sea catfish Plotosus japonicus, like that of other catfishes, is highly developed. To clarify the details of the morphology of the peripheral gustatory system of Plotosus, we used whole-mount immunohistochemistry to investigate the distribution and innervation of the taste buds within multiple organs including the barbels, oropharyngeal cavity, fins (pectoral, dorsal, and caudal), and trunk. Labeled taste buds could be observed in all the organs examined. The density of the taste buds was higher along the leading edges of the barbels and fins; this likely increases the chance of detecting food. In all the fins, the taste buds were distributed in linear arrays parallel to the fin rays. Labeling of nerve fibers by anti-acetylated tubulin antibody showed that the taste buds within each sensory field are innervated in different ways. In the barbels, large nerve bundles run along the length of the organ, with fascicles branching off to innervate polygonally organized groups of taste buds. In the fins, nerve bundles run along the axis of fin rays to innervate taste buds lying in a line. In each case, small fascicles of fibers branch from large bundles and terminate within the basal portions of the taste buds. Serotonin immunohistochemistry demonstrated that most of the taste buds in all the organs examined contained disk-shaped serotonin-immunopositive cells in their basal region. This indicates a similar organization of the taste buds, in terms of the existence of serotonin-immunopositive basal cells, across the different sensory fields in this species. © 2017 S. Karger AG, Basel.

UF{sub 6} cylinder fire test

Energy Technology Data Exchange (ETDEWEB)

Park, S.H. [Oak Ridge K-25 Site, Oak Ridge, TN (United States)

1991-12-31

With the increasing number of nuclear reactors for power generation, there is a comparable increase in the amount of UF{sub 6} being transported. Likewise, the probability of having an accident involving UF{sub 6}-filled cylinders also increases. Accident scenarios which have been difficult to assess are those involving a filled UF{sub 6} cylinder subjected to fire. A study is underway at the Oak Ridge K-25 Site, as part of the US DOE Enrichment Program, to provide empirical data and a computer model that can be used to evaluate various cylinder-in-fire scenarios. It is expected that the results will provide information leading to better handling of possible fire accidents as well as show whether changes should be made to provide different physical protection during shipment. The computer model being developed will be capable of predicting the rupture of various cylinder sizes and designs as well as the amount of UF{sub 6}, its distribution in the cylinder, and the conditions of the fire.

Three-dimensional vortex flow near the endwall of a short cylinder in crossflow: Uniform-diameter circular cylinder

International Nuclear Information System (INIS)

Chen, S.B.; Sanitjai, S.; Ghosh, K.; Goldstein, R.J.

2012-01-01

Flow characteristics, around a short uniform-diameter circular cylinder in crossflow, are investigated experimentally. Extensive flow visualization using oil-lampblack and smoke-wire methods have been performed. Near-wake velocity measurements have been performed using a hotwire anemometer. Complex secondary flows are observed on and around the cylinder in crossflow. Multiple vortices are observed in the horseshoe vortex system near the cylinder–endwall junction. Based on this flow visualization and local mass transfer measurement results, a six-vortex secondary flow model has been proposed. - Highlights: ► Flow visualizations and velocity measurements for a short circular cylinder. ► Six vortices in the horseshoe vortex system upstream of the base of the cylinder. ► Cross-stream turbulence intensity profiles show a similarity in their shape.

Ontogeny of neuro-insular complexes and islets innervation in the human pancreas.

Directory of Open Access Journals (Sweden)

Alexandra E. Proshchina

2014-04-01

Full Text Available The ontogeny of the neuro-insular complexes (NIC and the islets innervation in human pancreas has not been studied in detail. Our aim was to describe the developmental dynamics and distribution of the nervous system structures in the endocrine part of human pancreas. We used doublestaining with antibodies specific to pan-neural markers (neuron-specific enolase (NSE and S100 protein and to hormones of pancreatic endocrine cells. NSE and S100-positive nerves and ganglia were identified in the human fetal pancreas from gestation week (gw 10 onwards. Later the density of S100 and NSE-positive fibers increased. In adults this network was sparse. The islets innervation started to form from gw 14. NSE-containing endocrine cells were identified from gw 12 onwards. Additionally, S100-positive cells were detected both in the periphery and within some of the islets starting at gw 14. The analysis of islets innervation has shown that the fetal pancreas contained neuro-insular complexes and the number of these complexes was reduced in adults. The highest density of neuro-insular complexes is detected during middle and late fetal periods, when the mosaic islets, typical for adults, form. The close integration between the developing pancreatic islets and the nervous system structures may play an important role not only in the hormone secretion, but also in the islets morphogenesis.

Ontogeny of neuro-insular complexes and islets innervation in the human pancreas.

Science.gov (United States)

Proshchina, Alexandra E; Krivova, Yulia S; Barabanov, Valeriy M; Saveliev, Sergey V

2014-01-01

The ontogeny of the neuro-insular complexes (NIC) and the islets innervation in human pancreas has not been studied in detail. Our aim was to describe the developmental dynamics and distribution of the nervous system structures in the endocrine part of human pancreas. We used double-staining with antibodies specific to pan-neural markers [neuron-specific enolase (NSE) and S100 protein] and to hormones of pancreatic endocrine cells. NSE and S100-positive nerves and ganglia were identified in the human fetal pancreas from gestation week (gw) 10 onward. Later the density of S100 and NSE-positive fibers increased. In adults, this network was sparse. The islets innervation started to form from gw 14. NSE-containing endocrine cells were identified from gw 12 onward. Additionally, S100-positive cells were detected both in the periphery and within some of the islets starting at gw 14. The analysis of islets innervation has shown that the fetal pancreas contained NIC and the number of these complexes was reduced in adults. The highest density of NIC is detected during middle and late fetal periods, when the mosaic islets, typical for adults, form. The close integration between the developing pancreatic islets and the nervous system structures may play an important role not only in the hormone secretion, but also in the islets morphogenesis.

Sensory and motor innervation of the crural diaphragm by the vagus nerves.

Science.gov (United States)

Young, Richard L; Page, Amanda J; Cooper, Nicole J; Frisby, Claudine L; Blackshaw, L Ashley

2010-03-01

During gastroesophageal reflux, transient lower esophageal sphincter relaxation and crural diaphragm (CD) inhibition occur concomitantly. Modifying vagus nerve control of transient lower esophageal sphincter relaxation is a major focus of development of therapeutics for gastroesophageal reflux disease, but neural mechanisms that coordinate the CD are poorly understood. Nerve tracing and immunolabeling were used to assess innervation of the diaphragm and lower esophageal sphincter in ferrets. Mechanosensory responses of vagal afferents in the CD and electromyography responses of the CD were recorded in novel in vitro preparations and in vivo. Retrograde tracing revealed a unique population of vagal CD sensory neurons in nodose ganglia and CD motor neurons in brainstem vagal nuclei. Anterograde tracing revealed specialized vagal endings in the CD and phrenoesophageal ligament-sites of vagal afferent mechanosensitivity recorded in vitro. Spontaneous electromyography activity persisted in the CD following bilateral phrenicotomy in vivo, while vagus nerve stimulation evoked electromyography responses in the CD in vitro and in vivo. We conclude that vagal sensory and motor neurons functionally innervate the CD and phrenoesophageal ligament. CD vagal afferents show mechanosensitivity to distortion of the gastroesophageal junction, while vagal motor neurons innervate both CD and distal esophagus and may represent a common substrate for motor control of the reflux barrier. Copyright 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.

Vagal innervation is required for pulmonary function phenotype in Htr4-/- mice.

Science.gov (United States)

House, John S; Nichols, Cody E; Li, Huiling; Brandenberger, Christina; Virgincar, Rohan S; DeGraff, Laura M; Driehuys, Bastiaan; Zeldin, Darryl C; London, Stephanie J

2017-04-01

Human genome-wide association studies have identified over 50 loci associated with pulmonary function and related phenotypes, yet follow-up studies to determine causal genes or variants are rare. Single nucleotide polymorphisms in serotonin receptor 4 ( HTR4 ) are associated with human pulmonary function in genome-wide association studies and follow-up animal work has demonstrated that Htr4 is causally associated with pulmonary function in mice, although the precise mechanisms were not identified. We sought to elucidate the role of neural innervation and pulmonary architecture in the lung phenotype of Htr4 -/- animals. We report here that the Htr4 -/- phenotype in mouse is dependent on vagal innervation to the lung. Both ex vivo tracheal ring reactivity and in vivo flexiVent pulmonary functional analyses demonstrate that vagotomy abrogates the Htr4 -/- airway hyperresponsiveness phenotype. Hyperpolarized 3 He gas magnetic resonance imaging and stereological assessment of wild-type and Htr4 -/- mice reveal no observable differences in lung volume, inflation characteristics, or pulmonary microarchitecture. Finally, control of breathing experiments reveal substantive differences in baseline breathing characteristics between mice with/without functional HTR4 in breathing frequency, relaxation time, flow rate, minute volume, time of inspiration and expiration and breathing pauses. These results suggest that HTR4's role in pulmonary function likely relates to neural innervation and control of breathing. Copyright © 2017 the American Physiological Society.

Prediction of External Corrosion for Steel Cylinders--2004 Report

International Nuclear Information System (INIS)

Schmoyer, RLS

2004-01-01

Depleted uranium hexafluoride (UF 6 ) is stored in over 60,000 steel cylinders at the East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee, at the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky, and at the Portsmouth Gaseous Diffusion Plant (PORTS) in Portsmouth, Ohio. The cylinders range in age from 4 to 53 years. Although when new the cylinders had wall thicknesses specified to within manufacturing tolerances, over the years corrosion has reduced their actual wall thicknesses. The UF 6 Cylinder Project is managed by the United States Department of Energy (DOE) to safely maintain the UF 6 and the cylinders containing it. This report documents activities that address UF 6 Cylinder Project requirements and actions involving forecasting cylinder wall thicknesses. These requirements are delineated in the System Requirements Document (LMES 1997a), and the actions needed to fulfill them are specified in the System Engineering Management Plan (LMES 1997b). The report documents cylinder wall thickness projections based on models fit to ultrasonic thickness (UT) measurement data. UT data is collected at various locations on randomly sampled cylinders. For each cylinder sampled, the minimum UT measurement approximates the actual minimum thickness of the cylinder. Projections of numbers of cylinders expected to fail various thickness criteria are computed from corrosion models relating minimum wall thickness to cylinder age, initial thickness estimates, and cylinder subpopulations defined in terms of plant site, yard, top or bottom storage positions, nominal thickness, etc. In this report, UT data collected during FY03 is combined with UT data collected in earlier years (FY94-FY02), and all of the data is inventoried chronologically and by various subpopulations. The UT data is used to fit models of maximum pit depth and minimum thickness, and the fitted models are used to extrapolate minimum thickness estimates into the future and in turn to compute

Excessive peptidergic sensory innervation of cutaneous arteriole-venule shunts (AVS) in the palmar glabrous skin of fibromyalgia patients: implications for widespread deep tissue pain and fatigue.

Science.gov (United States)

Albrecht, Phillip J; Hou, Quanzhi; Argoff, Charles E; Storey, James R; Wymer, James P; Rice, Frank L

2013-06-01

To determine if peripheral neuropathology exists among the innervation of cutaneous arterioles and arteriole-venule shunts (AVS) in fibromyalgia (FM) patients. Cutaneous arterioles and AVS receive a convergence of vasoconstrictive sympathetic innervation, and vasodilatory small-fiber sensory innervation. Given our previous findings of peripheral pathologies in chronic pain conditions, we hypothesized that this vascular location may be a potential site of pathology and/or serotonergic and norepinephrine reuptake inhibitors (SNRI) drug action. Twenty-four female FM patients and nine female healthy control subjects were enrolled for study, with 14 additional female control subjects included from previous studies. AVS were identified in hypothenar skin biopsies from 18/24 FM patient and 14/23 control subjects. Multimolecular immunocytochemistry to assess different types of cutaneous innervation in 3 mm skin biopsies from glabrous hypothenar and trapezius regions. AVS had significantly increased innervation among FM patients. The excessive innervation consisted of a greater proportion of vasodilatory sensory fibers, compared with vasoconstrictive sympathetic fibers. In contrast, sensory and sympathetic innervation to arterioles remained normal. Importantly, the sensory fibers express α2C receptors, indicating that the sympathetic innervation exerts an inhibitory modulation of sensory activity. The excessive sensory innervation to the glabrous skin AVS is a likely source of severe pain and tenderness in the hands of FM patients. Importantly, glabrous AVS regulate blood flow to the skin in humans for thermoregulation and to other tissues such as skeletal muscle during periods of increased metabolic demand. Therefore, blood flow dysregulation as a result of excessive innervation to AVS would likely contribute to the widespread deep pain and fatigue of FM. SNRI compounds may provide partial therapeutic benefit by enhancing the impact of sympathetically mediated inhibitory

Associations between xerostomia, histopathological alterations, and autonomic innervation of labial salivary glands in men in late midlife.

Science.gov (United States)

Sørensen, Christiane Elisabeth; Larsen, Jytte Overgaard; Reibel, Jesper; Lauritzen, Martin; Mortensen, Erik Lykke; Osler, Merete; Pedersen, Anne Marie Lynge

2014-09-01

One aim of the present study was to investigate whether symptoms of oral dryness (xerostomia) during daytime, assessed in a study group of middle-aged male positive and negative outliers in cognition scores, were associated with age-related degenerative changes in human labial salivary glands and with quantitative measures of the glandular autonomic innervation. Another aim was to study the relation between the autonomic innervation and loss of secretory acinar cells in these glands. Labial salivary gland biopsies were taken from the lower lip from 190 men, born in 1953 and members of the Danish Metropolit birth cohort, who were examined for age-related changes in cognitive function and dental health as part of the Copenhagen University Center for Healthy Aging clinical neuroscience project. The glands were routinely processed and semi-quantitatively analyzed for inflammation, acinar atrophy, fibrosis, and adipocyte infiltration. Sections of labial salivary gland tissue were stained with the panneuronal marker PGP 9.5. In a subsample of 51 participants, the autonomic innervation of the glands was analyzed quantitatively by use of stereology. Labial salivary gland tissue samples from 33% of all participants displayed moderate to severe acinar atrophy and fibrosis (31%). Xerostomia was not significantly associated with structural changes of labial salivary glands, but in the subsample it was inversely related to the total nerve length in the glandular connective tissue. Acinar atrophy and fibrosis were negatively correlated with the parenchymal innervation and positively related to diffuse inflammation. The results from the present study indicate that aspects of the autonomic innervation of labial salivary glands may play a role in the occurrence of xerostomia which in the present study group was not significantly associated with degenerative changes in these glands. The findings further indicate that the integrity of labial salivary gland acini is related to the

Optimization and improvement of Halbach cylinder design

DEFF Research Database (Denmark)

Bjørk, Rasmus; Bahl, Christian Robert Haffenden; Smith, Anders

2008-01-01

possible volume of magnets with a given mean flux density in the cylinder bore. The volume of the cylinder bore could also be significantly increased by only slightly increasing the volume of the magnets, for a fixed mean flux density. Placing additional blocks of magnets on the end faces of the Halbach...... that this parameter was optimal for long Halbach cylinders with small rex. Using the previously mentioned additional blocks of magnets can improve the parameter by as much as 15% as well as improve the homogeneity of the field in the cylinder bore. ©2008 American Institute of Physics...

Prediction of External Corrosion for Steel Cylinders--2007 Report

Energy Technology Data Exchange (ETDEWEB)

Schmoyer, Richard L [ORNL

2008-01-01

Depleted uranium hexafluoride (DUF{sub 6}) is stored in over 62,000 containment cylinders at the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky, and at the Portsmouth Gaseous Diffusion Plant (PORTS) in Portsmouth, Ohio. Over 4,800 of the cylinders at Portsmouth were recently moved there from the East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee. The cylinders range in age up to 56 years and come in various models, but most are 48-inch diameter 'thin-wall'(312.5 mil) and 'thick-wall' (625 mil) cylinders and 30-inch diameter '30A' (including '30B') cylinders with 1/2-inch (500 mil) walls. Most of the cylinders are carbon steel, and they are subject to corrosion. The United States Department of Energy (DOE) manages the cylinders to maintain them and the DUF{sub 6} they contain. Cylinder management requirements are specified in the System Requirements Document (LMES 1997a), and the activities to fulfill them are specified in the System Engineering Management Plan (LMES 1997b). This report documents activities that address DUF{sub 6} cylinder management requirements involving measuring and forecasting cylinder wall thicknesses. As part of these activities, ultrasonic thickness (UT) measurements are made on samples of cylinders. For each sampled cylinder, multiple measurements are made in an attempt to find, approximately, the minimum wall thickness. Some cylinders have a skirt, which is an extension of the cylinder wall to protect the head (end) and valve. The head/skirt interface crevice is thought to be particularly vulnerable to corrosion, and for some skirted cylinders, in addition to the main body UT measurements, a separate suite of measurements is also made at the head/skirt interface. The main-body and head/skirt minimum thickness data are used to fit models relating minimum thickness to cylinder age, nominal thicknesses, and cylinder functional groups defined in terms of plant site, storage yard

700 bar hydrogen cylinder design, testing and certification

International Nuclear Information System (INIS)

Duncan, M.

2004-01-01

'Full text:' Light weight and high pressure cylinders for compressed hydrogen storage are essential components for fuel cell vehicles. Storage volume and mass are two key considerations. Current on-board hydrogen storage systems are based on a maximum pressure of 350 bar. While 350 bar systems are excellent solutions for many applications, some situations required higher storage densities due to space restrictions. As a result significant research and development work has been expended by cylinder manufacturers, systems providers, testing agencies and automotive manufacturers to develop 700 bar systems to reduce storage volume. Dynetek Industries Ltd has proactively developed a range of 700 bar storage cylinders based on a seamless aluminum liner over wrapped with a carbon fiber composite. This paper presents the challenges and processes involved in the design, testing and certification of the Dynetek Industries Ltd 700 bar cylinder. The paper also provides reasoning for further volume and mass optimization of compressed hydrogen cylinders by incorporating realistic cylinder usage parameters into standards. In particular the overly conservative fill life requirement for cylinders will be examined. (author)

Cylinder Position Servo Control Based on Fuzzy PID

Directory of Open Access Journals (Sweden)

Shibo Cai

2013-01-01

Full Text Available The arbitrary position control of cylinder has always been the hard challenge in pneumatic system. We try to develop a cylinder position servo control method by combining fuzzy PID with the theoretical model of the proportional valve-controlled cylinder system. The pressure differential equation of cylinder, pressure-flow equation of proportional valve, and moment equilibrium equation of cylinder are established. And the mathematical models of the cylinder driving system are linearized. Then fuzzy PID control algorithm is designed for the cylinder position control, including the detail analysis of fuzzy variables and domain, fuzzy logic rules, and defuzzification. The stability of the proposed fuzzy PID controller is theoretically proved according to the small gain theorem. Experiments for targets position of 250 mm, 300 mm, and 350 mm were done and the results showed that the absolute error of the position control is less than 0.25 mm. And comparative experiment between fuzzy PID and classical PID verified the advantage of the proposed algorithm.

Breached cylinder incident at the Portsmouth gaseous diffusion plant

Energy Technology Data Exchange (ETDEWEB)

Boelens, R.A. [Martin Marietta Energy Systems, Inc., Piketon, OH (United States)

1991-12-31

On June 16, 1990, during an inspection of valves on partially depleted product storage cylinders, a 14-ton partially depleted product cylinder was discovered breached. The cylinder had been placed in long-term storage in 1977 on the top row of Portsmouth`s (two rows high) storage area. The breach was observed when an inspector noticed a pile of green material along side of the cylinder. The breach was estimated to be approximately 8- inches wide and 16-inches long, and ran under the first stiffening ring of the cylinder. During the continuing inspection of the storage area, a second 14-ton product cylinder was discovered breached. This cylinder was stacked on the bottom row in the storage area in 1986. This breach was also located adjacent to a stiffening ring. This paper will discuss the contributing factors of the breaching of the cylinders, the immediate response, subsequent actions in support of the investigation, and corrective actions.

Prediction of External Corrosion for Steel Cylinders--2004 Report

Energy Technology Data Exchange (ETDEWEB)

Schmoyer, RLS

2004-07-07

Depleted uranium hexafluoride (UF{sub 6}) is stored in over 60,000 steel cylinders at the East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee, at the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky, and at the Portsmouth Gaseous Diffusion Plant (PORTS) in Portsmouth, Ohio. The cylinders range in age from 4 to 53 years. Although when new the cylinders had wall thicknesses specified to within manufacturing tolerances, over the years corrosion has reduced their actual wall thicknesses. The UF{sub 6} Cylinder Project is managed by the United States Department of Energy (DOE) to safely maintain the UF{sub 6} and the cylinders containing it. This report documents activities that address UF{sub 6} Cylinder Project requirements and actions involving forecasting cylinder wall thicknesses. These requirements are delineated in the System Requirements Document (LMES 1997a), and the actions needed to fulfill them are specified in the System Engineering Management Plan (LMES 1997b). The report documents cylinder wall thickness projections based on models fit to ultrasonic thickness (UT) measurement data. UT data is collected at various locations on randomly sampled cylinders. For each cylinder sampled, the minimum UT measurement approximates the actual minimum thickness of the cylinder. Projections of numbers of cylinders expected to fail various thickness criteria are computed from corrosion models relating minimum wall thickness to cylinder age, initial thickness estimates, and cylinder subpopulations defined in terms of plant site, yard, top or bottom storage positions, nominal thickness, etc. In this report, UT data collected during FY03 is combined with UT data collected in earlier years (FY94-FY02), and all of the data is inventoried chronologically and by various subpopulations. The UT data is used to fit models of maximum pit depth and minimum thickness, and the fitted models are used to extrapolate minimum thickness estimates into the future and in

Optimized Dose Distribution of Gammamed Plus Vaginal Cylinders

International Nuclear Information System (INIS)

Supe, Sanjay S.; Bijina, T.K.; Varatharaj, C.; Shwetha, B.; Arunkumar, T.; Sathiyan, S.; Ganesh, K.M.; Ravikumar, M.

2009-01-01

Endometrial carcinoma is the most common malignancy arising in the female genital tract. Intracavitary vaginal cuff irradiation may be given alone or with external beam irradiation in patients determined to be at risk for locoregional recurrence. Vaginal cylinders are often used to deliver a brachytherapy dose to the vaginal apex and upper vagina or the entire vaginal surface in the management of postoperative endometrial cancer or cervical cancer. The dose distributions of HDR vaginal cylinders must be evaluated carefully, so that clinical experiences with LDR techniques can be used in guiding optimal use of HDR techniques. The aim of this study was to optimize dose distribution for Gammamed plus vaginal cylinders. Placement of dose optimization points was evaluated for its effect on optimized dose distributions. Two different dose optimization point models were used in this study, namely non-apex (dose optimization points only on periphery of cylinder) and apex (dose optimization points on periphery and along the curvature including the apex points). Thirteen dwell positions were used for the HDR dosimetry to obtain a 6-cm active length. Thus 13 optimization points were available at the periphery of the cylinder. The coordinates of the points along the curvature depended on the cylinder diameters and were chosen for each cylinder so that four points were distributed evenly in the curvature portion of the cylinder. Diameter of vaginal cylinders varied from 2.0 to 4.0 cm. Iterative optimization routine was utilized for all optimizations. The effects of various optimization routines (iterative, geometric, equal times) was studied for the 3.0-cm diameter vaginal cylinder. The effect of source travel step size on the optimized dose distributions for vaginal cylinders was also evaluated. All optimizations in this study were carried for dose of 6 Gy at dose optimization points. For both non-apex and apex models of vaginal cylinders, doses for apex point and three dome

An update on corrosion monitoring in cylinder storage yards

Energy Technology Data Exchange (ETDEWEB)

Henson, H.M.; Newman, V.S.; Frazier, J.L. [Oak Ridge K-25 Site, TN (United States)

1991-12-31

Depleted uranium, from US uranium isotope enrichment activities, is stored in the form of solid uranium hexafluoride (UF{sub 6}) in A285 and A516 steel cylinders designed and manufactured to ASME Boiler and Pressure Vessel Code criteria. In general, storage facilities are open areas adjacent to the enrichment plants where the cylinders are exposed to weather. This paper describes the Oak Ridge program to determine the general corrosion behavior of UF{sub 6} cylinders, to determine cylinder yard conditions which are likely to affect long term storage of this material, and to assess cylinder storage yards against these criteria. This program is targeted at conditions specific to the Oak Ridge cylinder yards. Based on (a) determination of the current cylinder yard conditions, (b) determination of rusting behavior in regions of the cylinders showing accelerated attack, (c) monitoring of corrosion rates through periodic measurement of test coupons placed within the cylinder yards, and (d) establishment of a computer base to incorporate and retain these data, the technical division is working with the enrichment sites to implement an upgraded system for storage of this material until such time as it is used or converted.

Sympathetic Innervation Promotes Arterial Fate by Enhancing Endothelial ERK Activity.

Science.gov (United States)

Pardanaud, Luc; Pibouin-Fragner, Laurence; Dubrac, Alexandre; Mathivet, Thomas; English, Isabel; Brunet, Isabelle; Simons, Michael; Eichmann, Anne

2016-08-19

Arterial endothelial cells are morphologically, functionally, and molecularly distinct from those found in veins and lymphatic vessels. How arterial fate is acquired during development and maintained in adult vessels is incompletely understood. We set out to identify factors that promote arterial endothelial cell fate in vivo. We developed a functional assay, allowing us to monitor and manipulate arterial fate in vivo, using arteries isolated from quails that are grafted into the coelom of chick embryos. Endothelial cells migrate out from the grafted artery, and their colonization of host arteries and veins is quantified. Here we show that sympathetic innervation promotes arterial endothelial cell fate in vivo. Removal of sympathetic nerves decreases arterial fate and leads to colonization of veins, whereas exposure to sympathetic nerves or norepinephrine imposes arterial fate. Mechanistically, sympathetic nerves increase endothelial ERK (extracellular signal-regulated kinase) activity via adrenergic α1 and α2 receptors. These findings show that sympathetic innervation promotes arterial endothelial fate and may lead to novel approaches to improve arterialization in human disease. © 2016 American Heart Association, Inc.

Multiple Identified Neurons and Peripheral Nerves Innervating the Prothoracic Defense Glands in Stick Insects Reveal Evolutionary Conserved and Novel Elements of a Chemical Defense System

Directory of Open Access Journals (Sweden)

Johannes Strauß

2017-11-01

Full Text Available The defense glands in the dorsal prothorax are an important autapomorphic trait of stick insects (Phasmatodea. Here, we study the functional anatomy and neuronal innervation of the defense glands in Anisomorpha paromalus (Westwood, 1859 (Pseudophasmatinae, a species which sprays its defense secretions when disturbed or attacked. We use a neuroanatomical approach to identify the nerves innervating the gland muscles and the motoneurons with axons in the different nerves. The defense gland is innervated by nerves originating from two segments, the subesophageal ganglion (SOG, and the prothoracic ganglion. Axonal tracing confirms the gland innervation via the anterior subesophageal nerve, and two intersegmental nerves, the posterior subesophageal nerve, and the anterior prothoracic nerve. Axonal tracing of individual nerves reveals eight identified neuron types in the subesophageal or prothoracic ganglion. The strongest innervating nerve of the gland is the anterior subesophageal nerve, which also supplies dorsal longitudinal thorax muscles (neck muscles by separate nerve branches. Tracing of individual nerve branches reveals different sets of motoneurons innervating the defense gland (one ipsilateral and one contralateral subesophageal neuron or the neck muscle (ventral median neurons. The ipsilateral and contralateral subesophageal neurons have no homologs in related taxa like locusts and crickets, and thus evolved within stick insects with the differentiation of the defense glands. The overall innervation pattern suggests that the longitudinal gland muscles derived from dorsal longitudinal neck muscles. In sum, the innervating nerves for dorsal longitudinal muscles are conserved in stick insects, while the neuronal control system was specialized with conserved motoneurons for the persisting neck muscles, and evolutionarily novel subesophageal and prothoracic motoneurons innervating the defense gland.

NGSI: Function Requirements for a Cylinder Tracking System

International Nuclear Information System (INIS)

Branney, S.

2012-01-01

While nuclear suppliers currently track uranium hexafluoride (UF 6 ) cylinders in various ways, for their own purposes, industry practices vary significantly. The NNSA Office of Nonproliferation and International Security's Next Generation Safeguards Initiative (NGSI) has begun a 5-year program to investigate the concept of a global monitoring scheme that uniquely identifies and tracks UF 6 cylinders. As part of this effort, NGSI's multi-laboratory team has documented the 'life of a UF 6 cylinder' and reviewed IAEA practices related to UF 6 cylinders. Based on this foundation, this paper examines the functional requirements of a system that would uniquely identify and track UF 6 cylinders. There are many considerations for establishing a potential tracking system. Some of these factors include the environmental conditions a cylinder may be expected to be exposed to, where cylinders may be particularly vulnerable to diversion, how such a system may be integrated into the existing flow of commerce, how proprietary data generated in the process may be protected, what a system may require in terms of the existing standard for UF 6 cylinder manufacture or modifications to it and what the limiting technology factors may be. It is desirable that a tracking system should provide benefit to industry while imposing as few additional constraints as possible and still meeting IAEA safeguards objectives. This paper includes recommendations for this system and the analysis that generated them.

Oropharyngeal and laryngeal sensory innervation in the pathophysiology of swallowing disorders and sensory stimulation treatments.

Science.gov (United States)

Alvarez-Berdugo, Daniel; Rofes, Laia; Casamitjana, J Francesc; Padrón, Andreína; Quer, Miquel; Clavé, Pere

2016-09-01

Oropharyngeal dysphagia (OD) affects older and neurological patients, causing malnutrition and dehydration and increasing the risk for aspiration pneumonia. There is evidence that sensory deficits in those populations are closely related to swallowing disorders, and several research groups are developing new therapies based on sensory stimulation of this area. More information on the sensory innervation participating in the swallow response is needed to better understand the pathophysiology of OD and to develop new treatments. This review focuses on the sensory innervation of the human oropharynx and larynx in healthy people compared with patients with swallowing disorders in order to unravel the abnormalities that may lead to the loss of sensitivity in patients with OD. We also hypothesize the pathway through which active sensory-enhancement treatments may elicit their therapeutic effect on patients with swallowing dysfunctions. As far as we know, this is the first time a review covers the anatomy, histology, ultrastructure, and molecular biology of the sensory innervation of the swallowing function. © 2016 New York Academy of Sciences.

Target innervation is necessary for neuronal polyploidization in the terrestrial slug Limax.

Science.gov (United States)

Matsuo, Ryota; Yamagishi, Miki; Wakiya, Kyoko; Tanaka, Yoko; Ito, Etsuro

2013-08-01

The brain of gastropod mollusks contains many giant neurons with polyploid genomic DNAs. Such DNAs are generated through repeated DNA endoreplication during body growth. However, it is not known what triggers DNA endoreplication in neurons. There are two possibilities: (1) DNAs are replicated in response to some unknown molecules in the hemolymph that reflect the nutritive status of the animal; or (2) DNAs are replicated in response to some unknown factors that are retrogradely transported through axons from the innervated target organs. We first tested whether hemolymph with rich nutrition could induce DNA endoreplication. We tested whether the transplanted brain exhibits enhanced DNA endoreplication like an endogenous brain does when transplanted into the homocoel of the body of a slug whose body growth is promoted by an increased food supply. However, no enhancement was observed in the frequency of DNA endoreplication when we compared the transplanted brains in the growth-promoted and growth-suppressed host slugs, suggesting that the humoral environment is irrelevant to triggering the body growth-dependent DNA endoreplication. Next, we tested the requirement of target innervation by surgically dissecting a unilateral posterior pedal nerve of an endogenous brain. Substantially lower number of neurons exhibited DNA endoreplication in the pedal ganglion ipsilateral to the dissected nerve. These results support the view that enhanced DNA endoreplication is mediated by target innervation and is not brought about through the direct effect of humoral factors in the hemolymph during body growth. Copyright © 2013 Wiley Periodicals, Inc.

Theory of interacting dislocations on cylinders.

Science.gov (United States)

Amir, Ariel; Paulose, Jayson; Nelson, David R

2013-04-01

We study the mechanics and statistical physics of dislocations interacting on cylinders, motivated by the elongation of rod-shaped bacterial cell walls and cylindrical assemblies of colloidal particles subject to external stresses. The interaction energy and forces between dislocations are solved analytically, and analyzed asymptotically. The results of continuum elastic theory agree well with numerical simulations on finite lattices even for relatively small systems. Isolated dislocations on a cylinder act like grain boundaries. With colloidal crystals in mind, we show that saddle points are created by a Peach-Koehler force on the dislocations in the circumferential direction, causing dislocation pairs to unbind. The thermal nucleation rate of dislocation unbinding is calculated, for an arbitrary mobility tensor and external stress, including the case of a twist-induced Peach-Koehler force along the cylinder axis. Surprisingly rich phenomena arise for dislocations on cylinders, despite their vanishing Gaussian curvature.

Low-Re flow past an isolated cylinder with rounded corners

KAUST Repository

Zhang, Wei

2016-06-29

Direct numerical simulation is performed for flow past an isolated cylinder at Re=1,000. The corners of the cylinder are rounded at different radii, with the non-dimensional radius of curvature varying from R+=R/D=0.000 (square cylinder with sharp corners) to 0.500 (circular cylinder), in which R is the corner radius and D is the cylinder diameter. Our objective is to investigate the effect of the rounded corners on the development of the separated and transitional flow past the cylinder in terms of time-averaged statistics, time-dependent behavior, turbulent statistics and three-dimensional flow patterns. Numerical results reveal that the rounding of the corners significantly reduces the time-averaged drag and the force fluctuations. The wake flow downstream of the square cylinder recovers the slowest and has the largest wake width. However, the statistical quantities do not monotonically vary with the corner radius, but exhibit drastic variations between the cases of square cylinder and partially rounded cylinders, and between the latter and the circular cylinder. The free shear layer separated from the R+=0.125 cylinder is the most stable in which the first roll up of the wake vortex occurs furthest from the cylinder and results in the largest recirculation bubble, whose size reduces as R+ further increases. The coherent and incoherent Reynolds stresses are most pronounced in the near-wake close to the reattachment point, while also being noticeable in the shear layer for the square and R+=0.125 cylinders. The wake vortices translate in the streamwise direction with a convection velocity that is almost constant at approximately 80% of the incoming flow velocity. These vortices exhibit nearly the same trajectory for the rounded cylinders and are furthest away from the wake centerline for the square one. The flow past the square cylinder is strongly three-dimensional as indicated by the significant primary and secondary enstrophy, while it is dominated by the

Self-accelerating parabolic cylinder waves in 1-D

Energy Technology Data Exchange (ETDEWEB)

Yuce, C., E-mail: cyuce@anadolu.edu.tr

2016-11-25

Highlights: • We find a new class of self-accelerating waves. • We show that parabolic cylinder waves self-accelerates in a parabolic potential. • We discuss that truncated parabolic cylinder waves propagates large distance without almost being non-diffracted in free space. - Abstract: We introduce a new self-accelerating wave packet solution of the Schrodinger equation in one dimension. We obtain an exact analytical parabolic cylinder wave for the inverted harmonic potential. We show that truncated parabolic cylinder waves exhibits their accelerating feature.

Application of the exact solution for scattering by an infinite cylinder to the estimation of scattering by a finite cylinder.

Science.gov (United States)

Wang, R T; van de Hulst, H C

1995-05-20

A new algorithm for cylindrical Bessel functions that is similar to the one for spherical Bessel functions allows us to compute scattering functions for infinitely long cylinders covering sizes ka = 2πa/λ up to 8000 through the use of only an eight-digit single-precision machine computation. The scattering function and complex extinction coefficient of a finite cylinder that is seen near perpendicular incidence are derived from those of an infinitely long cylinder by the use of Huygens's principle. The result, which contains no arbitrary normalization factor, agrees quite well with analog microwave measurements of both extinction and scattering for such cylinders, even for an aspect ratio p = l/(2a) as low as 2. Rainbows produced by cylinders are similar to those for spherical drops but are brighter and have a lower contrast.

Estrogen Replacement Regulates Vaginal Innervations in Ovariectomized Adult Virgin Rats: A Histological Study

Directory of Open Access Journals (Sweden)

Ting Li

2017-01-01

Full Text Available Background. Our previous Gräfenberg spot findings confirmed that the distal-third areas of the anterior vaginal wall bore a significantly greater number of nerves and sexual hormone may have certain degree of influence on these significant differences. However, the role of estrogen in vaginal innervations remains controversial. Methods. To investigate whether hormonal-neural interactions occur in the vagina, sixty rats were randomly divided into six groups: Sham-operated, ovariectomy, and 4 treatment groups. After 2 weeks of treatment, vaginal biopsies were prepared with hematoxylin and eosin and PGP9.5 using immunohistochemistry. Results. The density of small nerve fibers was significantly higher in the distal-half areas of intact vaginal walls than the proximal-half areas (P=0.001. In contrast, the overall PGP 9.5-ir fiber innervation density was significantly decreased in the OVX rats subjected to surgical menopause. Sustained estrogen administration for 2 weeks resulted in nerve fiber proliferation, with values reaching normal levels in the low-dose estradiol valerate group. Conclusion. Our findings indicate that systemic hormonal therapy with low-dose estradiol valerate is effective and safe for treating deficient vaginal innervation caused by low level of estrogen activity in menopausal women and may aid studies to identify an optimal estradiol dose to provide relief from vaginal discomfort.

Insulin resistance is associated with impaired cardiac sympathetic innervation in patients with heart failure.

Science.gov (United States)

Paolillo, S; Rengo, G; Pellegrino, T; Formisano, R; Pagano, G; Gargiulo, P; Savarese, G; Carotenuto, R; Petraglia, L; Rapacciuolo, A; Perrino, C; Piscitelli, S; Attena, E; Del Guercio, L; Leosco, D; Trimarco, B; Cuocolo, A; Perrone-Filardi, P

2015-10-01

Insulin resistance (IR) represents, at the same time, cause and consequence of heart failure (HF) and affects prognosis in HF patients, but pathophysiological mechanisms remain unclear. Hyperinsulinemia, which characterizes IR, enhances sympathetic drive, and it can be hypothesized that IR is associated with impaired cardiac sympathetic innervation in HF. Yet, this hypothesis has never been investigated. Aim of the present observational study was to assess the relationship between IR and cardiac sympathetic innervation in non-diabetic HF patients. One hundred and fifteen patients (87% males; 65 ± 11.3 years) with severe-to-moderate HF (ejection fraction 32.5 ± 9.1%) underwent iodine-123 meta-iodobenzylguanidine ((123)I-MIBG) myocardial scintigraphy to assess sympathetic innervation and Homeostasis Model Assessment Insulin Resistance (HOMA-IR) evaluation to determine the presence of IR. From (123)I-MIBG imaging, early and late heart to mediastinum (H/M) ratios and washout rate were calculated. Seventy-two (63%) patients showed IR and 43 (37%) were non-IR. Early [1.68 (IQR 1.53-1.85) vs. 1.79 (IQR 1.66-1.95); P = 0.05] and late H/M ratio [1.50 (IQR 1.35-1.69) vs. 1.65 (IQR 1.40-1.85); P = 0.020] were significantly reduced in IR compared with non-IR patients. Early and late H/M ratio showed significant inverse correlation with fasting insulinemia and HOMA-IR. Cardiac sympathetic innervation is more impaired in patients with IR and HF compared with matched non-IR patients. These findings shed light on the relationship among IR, HF, and cardiac sympathetic nervous system. Additional studies are needed to clarify the pathogenetic relationship between IR and HF. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

46 CFR 58.30-30 - Fluid power cylinders.

Science.gov (United States)

2010-10-01

... all pneumatic power transmission systems. (b) Fluid power cylinders consisting of a container and a... 46 Shipping 2 2010-10-01 2010-10-01 false Fluid power cylinders. 58.30-30 Section 58.30-30... MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-30 Fluid power cylinders. (a) The...

Nonlinear bending and collapse analysis of a poked cylinder and other point-loaded cylinders

International Nuclear Information System (INIS)

Sobel, L.H.

1983-06-01

This paper analyzes the geometrically nonlinear bending and collapse behavior of an elastic, simply supported cylindrical shell subjected to an inward-directed point load applied at midlength. The large displacement analysis results for this thin (R/t = 638) poked cylinder were obtained from the STAGSC-1 finite element computer program. STAGSC-1 results are also presented for two other point-loaded shell problems: a pinched cylinder (R/t = 100), and a venetian blind (R/t = 250)

Experimental seismic test of fluid coupled co-axial cylinders

International Nuclear Information System (INIS)

Chu, M.L.; Brown, S.J.; Lestingi, J.F.

1979-01-01

The dynamic response of fluid coupled coaxial cylindrical shells is of interest to the nuclear industry with respect to the seismic design of the reactor vessel and thermal liner. The experiments described present a series of tests which investigate the effect of the annular clearance between the cylinders (gap) on natural frequency, damping, and seismic response of both the inner and outer cylinders. The seismic input is a time history base load to the flexible fluid filled coaxial cylinders. The outer cylinder is elastically supported at both ends while the inner cylinder is supported only at the base (lower) end

Results of ultrasonic testing evaluations on UF6 storage cylinders

International Nuclear Information System (INIS)

Lykins, M.L.

1997-02-01

The three site cylinder management program is responsible for the safe storage of the DOE owned UF 6 storage cylinders at PORTS, PGDP and at the K-25 site. To ensure the safe storage of the UF 6 in the cylinders, the structural integrity of the cylinders must be evaluated. This report represents the latest cylinder integrity investigation that utilized wall thickness evaluations to identify thinning due to atmospheric exposure

Low-Re flow past an isolated cylinder with rounded corners

KAUST Repository

Zhang, Wei; Samtaney, Ravi

2016-01-01

rounded cylinders, and between the latter and the circular cylinder. The free shear layer separated from the R+=0.125 cylinder is the most stable in which the first roll up of the wake vortex occurs furthest from the cylinder and results in the largest

Sensory Innervation of the Nonspecialized Connective Tissues in the Low Back of the Rat

Science.gov (United States)

Corey, Sarah M.; Vizzard, Margaret A.; Badger, Gary J.; Langevin, Helene M.

2011-01-01

Chronic musculoskeletal pain, including low back pain, is a worldwide debilitating condition; however, the mechanisms that underlie its development remain poorly understood. Pathological neuroplastic changes in the sensory innervation of connective tissue may contribute to the development of nonspecific chronic low back pain. Progress in understanding such potentially important abnormalities is hampered by limited knowledge of connective tissue's normal sensory innervation. The goal of this study was to evaluate and quantify the sensory nerve fibers terminating within the nonspecialized connective tissues in the low back of the rat. With 3-dimensional reconstructions of thick (30–80 μm) tissue sections we have for the first time conclusively identified sensory nerve fiber terminations within the collagen matrix of connective tissue in the low back. Using dye labeling techniques with Fast Blue, presumptive dorsal root ganglia cells that innervate the low back were identified. Of the Fast Blue-labeled cells, 60–88% also expressed calcitonin gene-related peptide (CGRP) immunoreactivity. Based on the immunolabeling with CGRP and the approximate size of these nerve fibers (≤2 μm) we hypothesize that they are Aδ or C fibers and thus may play a role in the development of chronic pain. PMID:21411968

Label inspection of approximate cylinder based on adverse cylinder panorama

Science.gov (United States)

Lin, Jianping; Liao, Qingmin; He, Bei; Shi, Chenbo

2013-12-01

This paper presents a machine vision system for automated label inspection, with the goal to reduce labor cost and ensure consistent product quality. Firstly, the images captured from each single-camera are distorted, since the inspection object is approximate cylindrical. Therefore, this paper proposes an algorithm based on adverse cylinder projection, where label images are rectified by distortion compensation. Secondly, to overcome the limited field of viewing for each single-camera, our method novelly combines images of all single-cameras and build a panorama for label inspection. Thirdly, considering the shake of production lines and error of electronic signal, we design the real-time image registration to calculate offsets between the template and inspected images. Experimental results demonstrate that our system is accurate, real-time and can be applied for numerous real- time inspections of approximate cylinders.

Limited distal organelles and synaptic function in extensive monoaminergic innervation.

Science.gov (United States)

Tao, Juan; Bulgari, Dinara; Deitcher, David L; Levitan, Edwin S

2017-08-01

Organelles such as neuropeptide-containing dense-core vesicles (DCVs) and mitochondria travel down axons to supply synaptic boutons. DCV distribution among en passant boutons in small axonal arbors is mediated by circulation with bidirectional capture. However, it is not known how organelles are distributed in extensive arbors associated with mammalian dopamine neuron vulnerability, and with volume transmission and neuromodulation by monoamines and neuropeptides. Therefore, we studied presynaptic organelle distribution in Drosophila octopamine neurons that innervate ∼20 muscles with ∼1500 boutons. Unlike in smaller arbors, distal boutons in these arbors contain fewer DCVs and mitochondria, although active zones are present. Absence of vesicle circulation is evident by proximal nascent DCV delivery, limited impact of retrograde transport and older distal DCVs. Traffic studies show that DCV axonal transport and synaptic capture are not scaled for extensive innervation, thus limiting distal delivery. Activity-induced synaptic endocytosis and synaptic neuropeptide release are also reduced distally. We propose that limits in organelle transport and synaptic capture compromise distal synapse maintenance and function in extensive axonal arbors, thereby affecting development, plasticity and vulnerability to neurodegenerative disease. © 2017. Published by The Company of Biologists Ltd.

A Study of Gas Economizing Pneumatic Cylinder

International Nuclear Information System (INIS)

Li, T C; Wu, H W; Kuo, M J

2006-01-01

The pneumatic cylinder is the most typical actuator in the pneumatic equipment, and its mechanism is so simple that it is often used to operate point to point driving without the feedback loop in various automatic machines. But, the energy efficiency of pneumatic system is very poor compared with electrical systems and hydraulic systems. So, it is very important to discuss the energy saving for the pneumatic cylinder systems. In this thesis, we proposed three methods to apply the reduction in the air consumed for pneumatic cylinder systems. An air charge accumulator is used to absorb the exhausted compress air and a boost valve boosted the air to the higher pressure for used again. From the experiments, the direct used cylinder exhaust air may save about 40% of compress air

Visual Neurons in the Superior Colliculus Innervated by Islet2+ or Islet2− Retinal Ganglion Cells Display Distinct Tuning Properties

Directory of Open Access Journals (Sweden)

Rachel B. Kay

2017-10-01

Full Text Available Throughout the visual system, different subtypes of neurons are tuned to distinct aspects of the visual scene, establishing parallel circuits. Defining the mechanisms by which such tuning arises has been a long-standing challenge for neuroscience. To investigate this, we have focused on the retina’s projection to the superior colliculus (SC, where multiple visual neuron subtypes have been described. The SC receives inputs from a variety of retinal ganglion cell (RGC subtypes; however, which RGCs drive the tuning of different SC neurons remains unclear. Here, we pursued a genetic approach that allowed us to determine the tuning properties of neurons innervated by molecularly defined subpopulations of RGCs. In homozygous Islet2-EphA3 knock-in (Isl2EA3/EA3 mice, Isl2+ and Isl2− RGCs project to non-overlapping sub-regions of the SC. Based on molecular and anatomic data, we show that significantly more Isl2− RGCs are direction-selective (DS in comparison with Isl2+ RGCs. Targeted recordings of visual responses from each SC sub-region in Isl2EA3/EA3 mice revealed that Isl2− RGC-innervated neurons were significantly more DS than those innervated by Isl2+ RGCs. Axis-selective (AS neurons were found in both sub-regions, though AS neurons innervated by Isl2+ RGCs were more tightly tuned. Despite this segregation, DS and AS neurons innervated by Isl2+ or Isl2− RGCs did not differ in their spatial summation or spatial frequency (SF tuning. Further, we did not observe alterations in receptive field (RF size or structure of SC neurons innervated by Isl2+ or Isl2− RGCs. Together, these data show that innervation by Isl2+ and Isl2− RGCs results in distinct tuning in the SC and set the stage for future studies investigating the mechanisms by which these circuits are built.

Enrichment Assay Methods Development for the Integrated Cylinder Verification System

Energy Technology Data Exchange (ETDEWEB)

Smith, Leon E.; Misner, Alex C.; Hatchell, Brian K.; Curtis, Michael M.

2009-10-22

International Atomic Energy Agency (IAEA) inspectors currently perform periodic inspections at uranium enrichment plants to verify UF6 cylinder enrichment declarations. Measurements are typically performed with handheld high-resolution sensors on a sampling of cylinders taken to be representative of the facility's entire product-cylinder inventory. Pacific Northwest National Laboratory (PNNL) is developing a concept to automate the verification of enrichment plant cylinders to enable 100 percent product-cylinder verification and potentially, mass-balance calculations on the facility as a whole (by also measuring feed and tails cylinders). The Integrated Cylinder Verification System (ICVS) could be located at key measurement points to positively identify each cylinder, measure its mass and enrichment, store the collected data in a secure database, and maintain continuity of knowledge on measured cylinders until IAEA inspector arrival. The three main objectives of this FY09 project are summarized here and described in more detail in the report: (1) Develop a preliminary design for a prototype NDA system, (2) Refine PNNL's MCNP models of the NDA system, and (3) Procure and test key pulse-processing components. Progress against these tasks to date, and next steps, are discussed.

Enrichment Assay Methods Development for the Integrated Cylinder Verification System

International Nuclear Information System (INIS)

Smith, Leon E.; Misner, Alex C.; Hatchell, Brian K.; Curtis, Michael M.

2009-01-01

International Atomic Energy Agency (IAEA) inspectors currently perform periodic inspections at uranium enrichment plants to verify UF6 cylinder enrichment declarations. Measurements are typically performed with handheld high-resolution sensors on a sampling of cylinders taken to be representative of the facility's entire product-cylinder inventory. Pacific Northwest National Laboratory (PNNL) is developing a concept to automate the verification of enrichment plant cylinders to enable 100 percent product-cylinder verification and potentially, mass-balance calculations on the facility as a whole (by also measuring feed and tails cylinders). The Integrated Cylinder Verification System (ICVS) could be located at key measurement points to positively identify each cylinder, measure its mass and enrichment, store the collected data in a secure database, and maintain continuity of knowledge on measured cylinders until IAEA inspector arrival. The three main objectives of this FY09 project are summarized here and described in more detail in the report: (1) Develop a preliminary design for a prototype NDA system, (2) Refine PNNL's MCNP models of the NDA system, and (3) Procure and test key pulse-processing components. Progress against these tasks to date, and next steps, are discussed.

Sub-wavelength metamaterial cylinders with multiple dipole resonances

DEFF Research Database (Denmark)

Arslanagic, Samel; Breinbjerg, Olav

2009-01-01

It has been shown that the sub-wavelength resonances of the individual MTM cylinders also occur for electrically small configurations combining 2 or 4 cylinders. For the 2-and 4-cylinder configurations the overall size is 1/20 and 1/12.5 of the smallest wavelength, respectively. These MTM...... configuration thus offer the possibility for multi-resonant electrically small configurations....

Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders

NARCIS (Netherlands)

De Kanter, J.L.C.G.

2006-01-01

Summary accompanying the thesis: Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders by Jens de Kanter This thesis presents the investigation of the crush behaviour of both monolithic aluminium cylinders and externally fibre reinforced aluminium cylinders. The research is based

MONOMIALS AND BASIN CYLINDERS FOR NETWORK DYNAMICS.

Science.gov (United States)

Austin, Daniel; Dinwoodie, Ian H

We describe methods to identify cylinder sets inside a basin of attraction for Boolean dynamics of biological networks. Such sets are used for designing regulatory interventions that make the system evolve towards a chosen attractor, for example initiating apoptosis in a cancer cell. We describe two algebraic methods for identifying cylinders inside a basin of attraction, one based on the Groebner fan that finds monomials that define cylinders and the other on primary decomposition. Both methods are applied to current examples of gene networks.

Imperfection effects on the buckling of hydrostatically loaded cylinders

DEFF Research Database (Denmark)

Pinna, Rodney; Madsen, Søren

2015-01-01

imperfection sensitivity. Work on cylinders with other loading conditions, such as hydrostatic loading, is more limited. Similarly, there is limited work on cylinders with boundary conditions other than simply-supported ends. This paper looks at the case of cylinders under hydrostatic load, which is often...

Dynamic Measurement of Extra Long Stroke Cylinder in the Pneumatic System

International Nuclear Information System (INIS)

Chang Ho; Lan Chouwei; Chen, L-C

2006-01-01

This paper sets up the measure and control system of the dynamic characteristics of the extra long stroke cylinder. In the different types of the control conditions (e.g. different control law, operating pressure and direct control valves), using the measure and control system to measure the relation between the pressure and the velocity of the motion of the long stroke cylinder and to observe the stick slip phenomenon of the motion of the long stroke cylinder. In the innovate measurement system, two pressure sensors are set on the long stroke cylinder to measure the difference of the pressure between the inlet and the exhaust of the long stroke cylinder. In additions, a draw line encoder is set on the system to measure the position and the velocity of the motion of the long stroke cylinder. The measuring data of the measure system is transferred to the computer via A/D interface card and counter card, and Home-made program of Haptic Interface Device is used to control the system, saving the data of the motion of the long stroke cylinder. The system uses different types of direction control valve to control the motion of the long stroke cylinder and compares the difference of the motion of the long stroke cylinder. The results show that the motion of the cylinder that pauses in the middle of the cylinder stroke and causes the stick slip phenomenon is more violent than the stick slip phenomenon in other position. When the length of the pause time reaches the some range, the acceleration of the motion of the cylinder will be rised substantially. This paper not only focuses on the testing method of the dynamic characteristics of the motion of the long stroke cylinder, but also includes the analysis of the dynamic characteristics of the motion of the long stroke cylinder. It provides the data of the dynamic characteristics of the motion of the long stroke cylinder to improve and design the pneumatic system of the long stroke cylinder

Inner and outer cylinders of the CMS vacuum tank.

CERN Multimedia

Patrice Loïez

2002-01-01

The vacuum tank of the CMS magnet system consists of inner and outer stainless-steel cylinders and houses the superconducting coil. The inner cylinder contains all the barrel sub-detectors, which it supports via a system of horizontal rails. The cylinder is pictured here in the vertical position on a yellow platform mounted on the ferris-wheel support structure. This will allow it to be pivoted and inserted into the already installed outer cylinder, through which this photo was taken.

Flow past two tandem square cylinders vibrating transversely in phase

International Nuclear Information System (INIS)

Mithun, M G; Tiwari, Shaligram

2014-01-01

Numerical investigations have been carried out to study the wake characteristics of flow past two tandem square cylinders vibrating in phase. Both the cylinders vibrate in a transverse direction, i.e., perpendicular to the incoming flow with the same frequency and amplitude. The frequency of vibration of the cylinders and the inter-cylinder spacing are varied for fixed values of the Reynolds number (Re = 100) and the amplitude ratio (A/D = 0.4). The synchronous or lock-in regime for the oscillatory wake of the vibrating cylinders has been identified by varying the frequency of the vibration from f e  = 0.4 f 0 to 1.6 f 0 (f 0 being the frequency of vortex shedding behind a stationary square cylinder). The characteristics of lift and drag and the mechanism of vortex shedding are studied by varying the excitation frequency within the lock-in range for each value of inter-cylinder spacing. The complex interaction of flow between the cylinders gives rise to a variety of characteristically different shedding patterns in their wake. For values of inter-cylinder spacing equal to 2D and 3D, periodic, as well as quasi-periodic, lock-in behaviors are observed in the synchronous range. (paper)

76 FR 38697 - High Pressure Steel Cylinders From China

Science.gov (United States)

2011-07-01

... imports from China of high pressure steel cylinders, provided for in subheading 7311.00.00 of the... threatened with material injury by reason of LTFV and subsidized imports of high pressure steel cylinders... contained in USITC Publication 4241 (July 2011), entitled High Pressure Steel Cylinders from China...

Experiments of flow-induced in-line oscillation of a circular cylinder in a water tunnel. 2. Influence of the aspect ratio of a cantilevered circular cylinder

International Nuclear Information System (INIS)

Nakamura, Akira; Okajima, Atsushi; Kosugi, Takashi

2001-01-01

The flow-induced in-line oscillation of a cantilevered circular cylinder was experimentally studied through free-oscillation tests in a water tunnel. The response displacement amplitude at a circular cylinder tip was measured at reduced velocity from 1.0 to 4.0. A cantilevered cylinder was supported by a plate spring mounted on the water tunnel wall. The cylinder aspect ratio was varied from 5 to 21 to investigate the effect of aspect ratio on the response displacement. It is found that cylinders with aspect ratios of 5 and 10 have one excitation region, while cylinders with aspect ratios of 14 and 21 have two excitation regions. The aspect ratio, therefore, affects the amplitude of the excitation regions. The influence of end-effect was also investigated using cylinders with an end plate attached to the free end. Since the cylinders with an end plate show two excitation regions, even at an aspect ratio of 5, the flow around the free end of a cantilevered cylinder causes the end-effect. The mechanism of vibration was investigated using a cylinder with a splitter plate in wake to prevent alternate vortices. The amplitude is greater than those of a normal cylinder without a splitter plate, especially at V r =2.3 to 3.0, where a cylinder with an end plate shows the second excitation region. In order words, the alternate vortices suppress the amplitude in this range. The maximum amplitude of each excitation region decreases in proportion to C n and the amplitude of the first excitation is more sensitive to C n . (author)

Modeling flow for modified concentric cylinder rheometer geometry

Science.gov (United States)

Ekeruche, Karen; Connelly, Kelly; Kavehpour, H. Pirouz

2016-11-01

Rheology experiments on biological fluids can be difficult when samples are limited in volume, sensitive to degradation, and delicate to extract from tissues. A probe-like geometry has been developed to perform shear creep experiments on biological fluids and to use the creep response to characterize fluid material properties. This probe geometry is a modified concentric cylinder setup, where the gap is large and we assume the inner cylinder rotates in an infinite fluid. To validate this assumption we perform shear creep tests with the designed probe on Newtonian and non-Newtonian fluids and vary the outer cylinder container diameter. We have also created a numerical model based on the probe geometry setup to compare with experimental results at different outer cylinder diameters. A creep test is modeled by applying rotation to the inner cylinder and solving for the deformation of the fluid throughout the gap. Steady state viscosity values are calculated from creep compliance curves and compared between experimental and numerical results.

Natural convection heat transfer on two horizontal cylinders in liquid sodium

Energy Technology Data Exchange (ETDEWEB)

Hata, K.; Shiotsu, M.; Takeuchi, Y. [Institute of Atomic Energy, Kyoto Univ. (Japan)] [and others

1995-09-01

Natural convection heat transfer on two horizontal 7.6 mm diameter test cylinders assembled with the ratio of the distance between each cylinder axis to the cylinder diameter, S/D, of 2 in liquid sodium was studied experimentally and theoretically. The heat transfer coefficients on the cylinder surface due to the same heat inputs ranging from 1.0 X 10{sup 7} to 1.0 x 10{sup 9} W/m{sup 3} were obtained experimentally for various setting angeles, {gamma}, between vertical direction and the plane including both of these cylinder axis over the range of zero to 90{degrees}. Theoretical equations for laminar natural convection heat transfer from the two horizontal cylinders were numerically solved for the same conditions as the experimental ones considering the temperature dependence of thermophysical properties concerned. The average Nusselt numbers, Nu, values on the Nu versus modified Rayleigh number, R{sub f}, graph. The experimental values of Nu for the upper cylinder are about 20% lower than those for the lower cylinder at {gamma} = 0{degrees} for the range of R{sub f} tested here. The value of Nu for the upper cylinder becomes higher and approaches that for the lower cylinder with the increase in {gamma} over range of 0 to 90{degrees}. The values of Nu for the lower cylinder at each {gamma} are almost in agreement with those for a single cylinder. The theoretical values of Nu on two cylinders except those for R{sub f}<4 at {gamma} = 0{degrees} are in agreement with the experimental data at each {gamma} with the deviations less than 15%. Correlations for Nu on the upper and lower cylinders were obtained as functions of S/D and {gamma} based n the theoretical solutions for the S/D ranged over 1.5 to 4.0.

Carbon fiber reinforced hierarchical orthogrid stiffened cylinder: Fabrication and testing

Science.gov (United States)

Wu, Hao; Lai, Changlian; Sun, Fangfang; Li, Ming; Ji, Bin; Wei, Weiyi; Liu, Debo; Zhang, Xi; Fan, Hualin

2018-04-01

To get strong, stiff and light cylindrical shell, carbon fiber reinforced hierarchical orthogrid stiffened cylinders are designed and fabricated. The cylinder is stiffened by two-scale orthogrid. The primary orthogrid has thick and high ribs and contains several sub-orthogrid cells whose rib is much thinner and lower. The primary orthogrid stiffens the bending rigidity of the cylinder to resist the global instability while the sub-orthogrid stiffens the bending rigidity of the skin enclosed by the primary orthogrid to resist local buckling. The cylinder is fabricated by filament winding method based on a silicone rubber mandrel with hierarchical grooves. Axial compression tests are performed to reveal the failure modes. With hierarchical stiffeners, the cylinder fails at skin fracture and has high specific strength. The cylinder will fail at end crushing if the end of the cylinder is not thickened. Global instability and local buckling are well restricted by the hierarchical stiffeners.

A characteristic analysis of the fluidic muscle cylinder

Science.gov (United States)

Kim, Dong-Soo; Bae, Sang-Kyu; Hong, Sung-In

2005-12-01

The fluidic muscle cylinder consists of an air bellows tube, flanges and lock nuts. It's features are softness of material and motion, simplicity of structure, low production cost and high power efficiency. Recently, unlikely the pneumatic cylinder, the fluidic muscle cylinder without air leakage, stick slip, friction, and seal was developed as a new concept actuator. It has the characteristics such as light weight, low price, high response, durable design, long life, high power, high contraction, which is innovative product fulfilling RT(Robot Technology) which is one of the nation-leading next generation strategy technologies 6T as well as cleanness technology. The application fields of the fluidic muscle cylinder are so various like fatigue tester, brake, accelerator, high technology testing device such as driving simulator, precise position, velocity, intelligent servo actuator under special environment such as load controlling system, and intelligent robot. In this study, we carried out the finite element modeling and analysis about the main design variables such as contraction ration and force, diameter increment of fluidic muscle cylinder. On the basis of finite element analysis, the prototype of fluidic muscle cylinder was manufactured and tested. Finally, we compared the results between the test and the finite element analysis.

Image analysis of moving seeds in an indented cylinder

DEFF Research Database (Denmark)

Buus, Ole; Jørgensen, Johannes Ravn

2010-01-01

inspection in seed cleaning equipment. A prototype of an indented cylinder will be constructed. To make it more dynamic, the cylinder itself will be manufactured using 3D printing technology. The input will come either from 3D scans of existing cylinders or by defining their topology using parametric B...

Beating motion of a circular cylinder in vortex-induced vibrations

Science.gov (United States)

Shen, Linwei; Chan, Eng-Soon; Wei, Yan

2018-04-01

In this paper, beating phenomenon of a circular cylinder in vortex-induced vibration is studied by numerical simulations in a systematic manner. The cylinder mass coefficients of 2 and 10 are considered, and the Reynolds number is 150. Two distinctive frequencies, namely cylinder oscillation and vortex shedding frequencies, are obtained from the harmonic analysis of the cylinder displacement. The result is consistent with that observed in laboratory experiments. It is found that the cylinder oscillation frequency changes with the natural frequency of the cylinder while the reduced velocity is varied. The added-mass coefficient of the cylinder in beating motion is therefore estimated. Meanwhile, the vortex shedding frequency does not change dramatically in the beating situations. In fact, it is very close to 0.2. Accordingly, the lift force coefficient has two main components associated with these two frequencies. Besides, higher harmonics of the cylinder oscillation frequency appear in the spectrum of the lift coefficient. Moreover, the vortex shedding timing is studied in the beating motion by examining the instantaneous flow fields in the wake, and two scenarios of the vortex formation are observed.

Inflation of polymer melts into elliptic and circular cylinders

DEFF Research Database (Denmark)

Rasmussen, Henrik Koblitz; Christensen, Jens Horslund; Gøttsche, Søren

2000-01-01

A thin sheet (membrane) of the polymeric material is clamped between a Teflon-coated thermostated plate and a thermostated aluminium cylinder. By applying thermostated air through the plate, the polymer membrane deforms into an elliptic or a circular cylinder. The position of the top of the infla......A thin sheet (membrane) of the polymeric material is clamped between a Teflon-coated thermostated plate and a thermostated aluminium cylinder. By applying thermostated air through the plate, the polymer membrane deforms into an elliptic or a circular cylinder. The position of the top...

Electromagnetic forces on type-II superconducting rotating cylinders

International Nuclear Information System (INIS)

Saif, A.G.; Refai, T.F.; El-Sabagh, M.A.

1995-01-01

Analytical solutions of the electromagnetic fields are presented for a system composed of an infinitely long superconducting cylinder rotating about its axis and placed parallel to two infinitely long normal conducting wires. Both wires carry the same alternating current. From the obtained electromagnetic fields the electromagnetic power loss on the cylinder surface, electromagnetic forces due to induced currents, electromagnetic torque, and the work opposing the rotation of the cylinder are calculated. (orig.)

Flow induced by a skewed vortex cylinder

DEFF Research Database (Denmark)

Branlard, Emmanuel Simon Pierre

2017-01-01

The velocity field induced by a skewed vortex cylinder of longitudinal and tangential vorticity is derived in this chapter by direct integration of the Biot– Savart law. The derivation steps are provided in details. The results of Castles and Durham for the skewed semi-infinite cylinder....... The content of this chapter is based on the publication of the author entitled "Cylindrical vortex wake model: skewed cylinder, application to yawed or tilted rotors" [1]. Results from this chapter are applied: in Chap. 21 to model a wind turbine (or rotor) in yaw, in Chap. 22 to derive a new yaw...

Oscillatory Stokes Flow Past a Slip Cylinder

Science.gov (United States)

Palaniappan, D.

2013-11-01

Two-dimensional transient slow viscous flow past a circular cylinder with Navier slip boundary conditions is considered in the limit of low-Reynolds number. The oscillatory Stokes flow problem around a cylinder is solved using the stream function method leading to an analytic solution in terms of modified Bessel functions of the second kind. The corresponding steady-state behavior yields the familiar paradoxical result first detected by Stokes. It is noted that the two key parameters, viz., the frequency λ, and the slip coefficient ξ have a significant impact on the flow field in the vicinity of the cylinder contour. In the limit of very low frequency, the flow is dominated by a term containing a well-known biharmonic function found by Stokes that has a singular behavior at infinity. Local streamlines for small times show interesting flow patterns. Attached eddies due to flow separation - observed in the no-slip case - either get detached or pushed away from the cylinder surface as ξ is varied. Computed asymptotic results predict that the flow exhibits inviscid behavior far away from the cylinder in the frequency range 0 < λ << 1 . Although the frequency of oscillations is finite, our exact solutions reveal fairly rapid transitions in the flow domain. Research Enhancement grant, TAMUCC.

Prediction of external corrosion for steel cylinders

International Nuclear Information System (INIS)

Lyon, B.F.

1997-02-01

The US Department of Energy (DOE) currently manages the UF 6 Cylinder Program (the program). The program was formed to address the depleted-uranium hexafluoride (UF 6 ) stored in approximately 50,000 carbon steel cylinders. The cylinders are located at three DOE sites: the K-25 site (K-25) at Oak Ridge, Tennessee; the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky, and the Portsmouth Gaseous Diffusion Plant (PORTS) in Portsmouth, Ohio. The System Requirements Document (SRD) (LMES 1996a) delineates the requirements of the program. The appropriate actions needed to fulfill these requirements are then specified within the System Engineering Management Plan (SEMP) (LMES 1996b). The report presented herein documents activities that in whole or in part satisfy specific requirements and actions stated in the UF 6 Cylinder Program SRD and SEMP with respect to forecasting cylinder conditions. The wall thickness projections made in this report are based on the assumption that the corrosion trends noted will continue. Some activities planned may substantially reduce the rate of corrosion, in which case the results presented here are conservative. The results presented here are intended to supersede those presented previously, as the quality of several of the datasets has improved

Vortex structure behind highly heated two cylinders in parallel arrangements

International Nuclear Information System (INIS)

Kurita, Eiichirou; Yahagi, Yuji

2008-01-01

Vortex structures behind twin, highly heated cylinders in parallel arrangements have been investigated experimentally. The experiments were conducted under the following conditions: cylinder diameter, D=4 mm; mean flow velocity, U ∞ =1.0 m/s; Reynolds number, Re=250; cylinder clearance, S/D=0.5 - 1.4; and cylinder heat flux, q=0 - 72.6 kW/m 2 . For S/D > 1.2, the Karman vortex street is formed alternately behind each cylinder divided on the slit flow. The slit flow velocity increases with a decrease in S/D and decreases with increasing heat flux. For S/D 2 ). As a result, the increased local kinematic viscosity and S/D play a key role for the vortex structure and formation behind arrangements of two parallel cylinders. (author)

Controlling chaos in a fluid flow past a movable cylinder

International Nuclear Information System (INIS)

Vallejo, Juan C.; Marino, Ines P.; Sanjuan, Miguel A.F.; Kurths, Juergen

2003-01-01

The model of a two-dimensional fluid flow past a cylinder is a relatively simple problem with a strong impact in many applied fields, such as aerodynamics or chemical sciences, although most of the involved physical mechanisms are not yet well known. This paper analyzes the fluid flow past a cylinder in a laminar regime with Reynolds number, Re, around 200, where two vortices appear behind the cylinder, by using an appropriate time-dependent stream function and applying non-linear dynamics techniques. The goal of the paper is to analyze under which circumstances the chaoticity in the wake of the cylinder might be modified, or even suppressed. And this has been achieved with the help of some indicators of the complexity of the trajectories for the cases of a rotating cylinder and an oscillating cylinder

76 FR 55736 - Safety Advisory: Unauthorized Marking of Compressed Gas Cylinders

Science.gov (United States)

2011-09-08

... certain of high- and low-pressure compressed gas cylinders, primarily fire extinguishers, by Atlas Fire...- pressure cylinders serviced by Atlas Fire Protection were marked and represented as requalified (visually... damage, serious personal injury, or death could result from the rupture of a cylinder. Cylinders not...

The Passive Neutron Enrichment Meter for Uranium Cylinder Assay

Energy Technology Data Exchange (ETDEWEB)

Miller, Karen A.; Menlove, Howard O.; Swinhoe, Martyn T.; Marlow, Johanna B. [Safeguards Science and Technology Group (N-1), Los Alamos National Laboratory, Los Alamos (United States)

2011-12-15

As fuel cycle technology becomes more prevalent around the world, international safeguards have become increasingly important in verifying that nuclear materials have not been diverted. Uranium enrichment technology is a critical pathway to nuclear weapons development, making safeguards of enrichment facilities especially important. Independently-verifiable material accountancy is a fundamental measure in detecting diversion of nuclear materials. This paper is about a new instrument for uranium cylinder assay for enrichment plant safeguards called the Passive Neutron Enrichment Meter (PNEM). The measurement objective is to simultaneously verify uranium mass and enrichment in Uf6 cylinders. It can be used with feed, product, and tails cylinders. Here, we consider the enrichment range up to 5% {sup 235}U. The concept is to use the Doubles-to-Singles count rate to give a measure of the {sup 235}U enrichment and the Singles count rate to provide a measure of the total uranium mass. The cadmium ratio is an additional signature for the enrichment that is especially useful for feed and tails cylinders. PNEM is a {sup 3}He-based system that consists of two portable detector pods. Uranium enrichment in UF{sub 6} cylinders is typically determined using a gamma-ray-based method that only samples a tiny volume of the cylinder's content and requires knowledge of the cylinder wall thickness. The PNEM approach has several advantages over gamma-ray-based methods including a deeper penetration depth into the cylinder, meaning it can be used with heterogeneous isotopic mixtures of UF{sub 6}. In this paper, we describe a Monte Carlo modelling study where we have examined the sensitivity of the system to systematic uncertainties such as the distribution of UF{sub 6} within the cylinder. We also compare characterization measurements of the PNEM prototype to the expected measurements calculated with Monte Carlo simulations.

Steady particulate flows in a horizontal rotating cylinder

Science.gov (United States)

Yamane, K.; Nakagawa, M.; Altobelli, S. A.; Tanaka, T.; Tsuji, Y.

1998-06-01

Results of discrete element method (DEM) simulation and magnetic resonance imaging (MRI) experiments are compared for monodisperse granular materials flowing in a half-filled horizontal rotating cylinder. Because opacity is not a problem for MRI, a long cylinder with an aspect ratio ˜7 was used and the flow in a thin transverse slice near the center was studied. The particles were mustard seeds and the ratio of cylinder diameter to particle diameter was approximately 50. The parameters compared were dynamic angle of repose, velocity field in a plane perpendicular to the cylinder axis, and velocity fluctuations at rotation rates up to 30 rpm. The agreement between DEM and MRI was good when the friction coefficient and nonsphericity were adjusted in the simulation for the best fit.

Proximity functions for general right cylinders

International Nuclear Information System (INIS)

Kellerer, A.M.

1981-01-01

Distributions of distances between pairs of points within geometrical objects, or the closely related proximity functions and geometric reduction factors, have applications to dosimetric and microdosimetric calculations. For convex bodies these functions are linked to the chord-length distributions that result from random intersections by straight lines. A synopsis of the most important relations is given. The proximity functions and related functions are derived for right cylinders with arbitrary cross sections. The solution utilizes the fact that the squares of the distances between two random points are sums of independently distributed squares of distances parallel and perpendicular to the axis of the cylinder. Analogous formulas are derived for the proximity functions or geometric reduction factors for a cylinder relative to a point. This requires only a minor modification of the solution

ROBUST CYLINDER FITTING IN THREE-DIMENSIONAL POINT CLOUD DATA

Directory of Open Access Journals (Sweden)

A. Nurunnabi

2017-05-01

Full Text Available This paper investigates the problems of cylinder fitting in laser scanning three-dimensional Point Cloud Data (PCD. Most existing methods require full cylinder data, do not study the presence of outliers, and are not statistically robust. But especially mobile laser scanning often has incomplete data, as street poles for example are only scanned from the road. Moreover, existence of outliers is common. Outliers may occur as random or systematic errors, and may be scattered and/or clustered. In this paper, we present a statistically robust cylinder fitting algorithm for PCD that combines Robust Principal Component Analysis (RPCA with robust regression. Robust principal components as obtained by RPCA allow estimating cylinder directions more accurately, and an existing efficient circle fitting algorithm following robust regression principles, properly fit cylinder. We demonstrate the performance of the proposed method on artificial and real PCD. Results show that the proposed method provides more accurate and robust results: (i in the presence of noise and high percentage of outliers, (ii for incomplete as well as complete data, (iii for small and large number of points, and (iv for different sizes of radius. On 1000 simulated quarter cylinders of 1m radius with 10% outliers a PCA based method fit cylinders with a radius of on average 3.63 meter (m; the proposed method on the other hand fit cylinders of on average 1.02 m radius. The algorithm has potential in applications such as fitting cylindrical (e.g., light and traffic poles, diameter at breast height estimation for trees, and building and bridge information modelling.

An experiments and characteristics analysis of the sealless cylinder

International Nuclear Information System (INIS)

Kim, Young Cheol; Kim, Dong Soo; Bae, Sang Kyu; Kim, Sung Jong

2004-01-01

This paper shows a performance analysis for conical type sealless cylinders and rod bearings. The pistons without seal have partly cylindrical and conical shapes. 2 dimensional Reynolds equation and FD(Finite Differential) numerical techniques are utilized for the performance analysis. The relationship among self-centering forces and leakage flows are investigated. Also, optimal design values for a sealless cylinder are presented. A prototype of sealless cylinder which had rod bearing with four pockets, five pockets, and six pockets was manufactured respectively. Leakage flow test is conducted to evaluate performance of piston and rod bearing in sealless cylinder

Effects of catheter-based renal denervation on cardiac sympathetic activity and innervation in patients with resistant hypertension.

Science.gov (United States)

Donazzan, Luca; Mahfoud, Felix; Ewen, Sebastian; Ukena, Christian; Cremers, Bodo; Kirsch, Carl-Martin; Hellwig, Dirk; Eweiwi, Tareq; Ezziddin, Samer; Esler, Murray; Böhm, Michael

2016-04-01

To investigate, whether renal denervation (RDN) has a direct effect on cardiac sympathetic activity and innervation density. RDN demonstrated its efficacy not only in reducing blood pressure (BP) in certain patients, but also in decreasing cardiac hypertrophy and arrhythmias. These pleiotropic effects occur partly independent from the observed BP reduction. Eleven patients with resistant hypertension (mean office systolic BP 180 ± 18 mmHg, mean antihypertensive medications 6.0 ± 1.5) underwent I-123-mIBG scintigraphy to exclude pheochromocytoma. We measured cardiac sympathetic innervation and activity before and 9 months after RDN. Cardiac sympathetic innervation was assessed by heart to mediastinum ratio (H/M) and sympathetic activity by wash out ratio (WOR). Effects on office BP, 24 h ambulatory BP monitoring, were documented. Office systolic BP and mean ambulatory systolic BP were significantly reduced from 180 to 141 mmHg (p = 0.006) and from 149 to 129 mmHg (p = 0.014), respectively. Cardiac innervation remained unchanged before and after RDN (H/M 2.5 ± 0.5 versus 2.6 ± 0.4, p = 0.285). Cardiac sympathetic activity was significantly reduced by 67 % (WOR decreased from 24.1 ± 12.7 to 7.9 ± 25.3 %, p = 0.047). Both, responders and non-responders experienced a reduction of cardiac sympathetic activity. RDN significantly reduced cardiac sympathetic activity thereby demonstrating a direct effect on the heart. These changes occurred independently from BP effects and provide a pathophysiological basis for studies, investigating the potential effect of RDN on arrhythmias and heart failure.

Magnetic susceptibility in the edged topological disordered nanoscopic cylinder

International Nuclear Information System (INIS)

Faizabadi, Edris; Omidi, Mahboubeh

2011-01-01

The effects of edged topological disorder on magnetic susceptibility are investigated in a nanoscopic cylinder threaded by a magnetic flux. Persistent current versus even or odd number of electrons shows different signs in ordered and disordered cylinders and also in short or long ones. In addition, temperature-averaged susceptibility has only diamagnetic signs in strong regimes and it is associated with paramagnetic signs in ordered and weak disordered ones. Besides, in an edged topological disordered cylinder, the temperature-averaged susceptibility decreases by raising the temperature somewhat and then increasing initiates and finally at high temperature tends to zero as the ordered one. - Research highlights: → Magnetic susceptibility in one-dimensional topological disordered quantum ring. → Edged topological disorder effect on magnetic susceptibility in nanoscopic cylinder. → Edged topological disorder effect on temperature-averaged susceptibility in cylinder.

Dynamical instability of a charged gaseous cylinder

Science.gov (United States)

Sharif, M.; Mumtaz, Saadia

2017-10-01

In this paper, we discuss dynamical instability of a charged dissipative cylinder under radial oscillations. For this purpose, we follow the Eulerian and Lagrangian approaches to evaluate linearized perturbed equation of motion. We formulate perturbed pressure in terms of adiabatic index by applying the conservation of baryon numbers. A variational principle is established to determine characteristic frequencies of oscillation which define stability criteria for a gaseous cylinder. We compute the ranges of radii as well as adiabatic index for both charged and uncharged cases in Newtonian and post-Newtonian limits. We conclude that dynamical instability occurs in the presence of charge if the gaseous cylinder contracts to the radius R*.

Prediction model of velocity field around circular cylinder over various Reynolds numbers by fusion convolutional neural networks based on pressure on the cylinder

Science.gov (United States)

Jin, Xiaowei; Cheng, Peng; Chen, Wen-Li; Li, Hui

2018-04-01

A data-driven model is proposed for the prediction of the velocity field around a cylinder by fusion convolutional neural networks (CNNs) using measurements of the pressure field on the cylinder. The model is based on the close relationship between the Reynolds stresses in the wake, the wake formation length, and the base pressure. Numerical simulations of flow around a cylinder at various Reynolds numbers are carried out to establish a dataset capturing the effect of the Reynolds number on various flow properties. The time series of pressure fluctuations on the cylinder is converted into a grid-like spatial-temporal topology to be handled as the input of a CNN. A CNN architecture composed of a fusion of paths with and without a pooling layer is designed. This architecture can capture both accurate spatial-temporal information and the features that are invariant of small translations in the temporal dimension of pressure fluctuations on the cylinder. The CNN is trained using the computational fluid dynamics (CFD) dataset to establish the mapping relationship between the pressure fluctuations on the cylinder and the velocity field around the cylinder. Adam (adaptive moment estimation), an efficient method for processing large-scale and high-dimensional machine learning problems, is employed to implement the optimization algorithm. The trained model is then tested over various Reynolds numbers. The predictions of this model are found to agree well with the CFD results, and the data-driven model successfully learns the underlying flow regimes, i.e., the relationship between wake structure and pressure experienced on the surface of a cylinder is well established.

Mechanical Integrity of Copper Canister Lid and Cylinder. Sensitivity study

International Nuclear Information System (INIS)

Karlsson, Marianne

2002-08-01

This report is part of a study of the mechanical integrity of canisters used for disposal of nuclear fuel waste. The overall objective is to determine and ensure the static and long-term strength of the copper canister lid and cylinder casing. The canisters used for disposal nuclear fuel waste of type BWR consists of an inner part (insert) of ductile cast iron and an outer part of copper. The copper canister is to provide a sealed barrier between the contents of the canister and the surroundings. The study in this report complements the finite element analyses performed in an earlier study. The analyses aim to evaluate the sensitivity of the canister to tolerances regarding the gap between the copper cylinder and the cast iron insert. Since great uncertainties regarding the material's long term creep properties prevail, analyses are also performed to evaluate the effect of different creep data on the resulting strain and stress state. The report analyses the mechanical response of the lid and flange of the copper canister when subjected to loads caused by pressure from swelling bentonite and from groundwater at a depth of 500 meter. The loads acting on the canister are somewhat uncertain and the cases investigated in this report are possible cases. Load cases analysed are: Pressure 15 MPa uniformly distributed on lid and 5 MPa uniformly distributed on cylinder; Pressure 5 MPa uniformly distributed on lid and 15 MPa uniformly distributed on cylinder; Pressure 20 MPa uniformly distributed on lid and cylinder; and Side pressures 10 MPa and 20 MPa uniformly distributed on part of the cylinder. Creep analyses are performed for two of the load cases. For all considered designs high principal stresses appear on the outside of the copper cylinder in the region from the weld down to the level of the lid lower edge. Altering the gap between lid and cylinder and/or between cylinder and insert only marginally affects the resulting stress state. Fitting the lid in the cylinder

Evaluation of Concrete Cylinder Tests Using Finite Elements

DEFF Research Database (Denmark)

Saabye Ottosen, Niels

1984-01-01

Nonlinear axisymmetric finite element analyses are performed on the uniaxial compressive test of concrete cylinders. The models include thick steel loading plates, and cylinders with height‐to‐diameter ratios (h/d) ranging from 1‐3 are treated. A simple constitutive model of the concrete is emplo......Nonlinear axisymmetric finite element analyses are performed on the uniaxial compressive test of concrete cylinders. The models include thick steel loading plates, and cylinders with height‐to‐diameter ratios (h/d) ranging from 1‐3 are treated. A simple constitutive model of the concrete...... uniaxial strength the use of geometrically matched loading plates seems to be advantageous. Finally, it is observed that for variations of the element size within limits otherwise required to obtain a realistic analysis, the results are insensitive to the element size....

SU-G-206-06: Analytic Dose Function for CT Scans in Infinite Cylinders as a Function of Scan Length and Cylinder Radius

Energy Technology Data Exchange (ETDEWEB)

Bakalyar, D [Henry Ford Health System, Detroit, MI (United States); Feng, W [New York Presbyterian Hospital, Tenafly, NJ (United States); McKenney, S [Children’s National Medical Center, Washington, DC (United States)

2016-06-15

Purpose: The radiation dose absorbed at a particular radius ρ within the central plane of a long cylinder following a CT scan is a function of the length of the scan L and the cylinder radius R along with kVp and cylinder composition. An analytic function was created that that not only expresses these dependencies but is integrable in closed form over the area of the central plane. This feature facilitates explicit calculation of the planar average dose. The “approach to equilibrium” h(L) discussed in the TG111 report is seamlessly included in this function. Methods: For a cylindrically symmetric radiation field, Monte Carlo calculations were performed to compute the dose distribution to long polyethylene cylinders for scans of varying L for cylinders ranging in radius from 5 to 20 cm. The function was developed from the resultant Monte Carlo data. In addition, the function was successfully fit to data taken from measurements on the 30 cm diameter ICRU/TG200 phantom using a real-time dosimeter. Results: Symmetry and continuity dictate a local extremum at the center which is a minimum for the larger sizes. There are competing effects as the beam penetrates the cylinder from the outside: attenuation, resulting in a decrease; scatter, abruptly increasing at the circumference. This competition may result in an absolute maximum between the center and outer edge leading to a “gull wing” shape for the radial dependence. For the smallest cylinders, scatter may dominate to the extent that there is an absolute maximum at the center. Conclusion: An integrable, analytic function has been developed that provides the radial dependency of dose for the central plane of a scan of length L for cylinders of varying diameter. Equivalently, we have developed h(L,R,ρ).

A Convenient Storage Rack for Graduated Cylinders

Science.gov (United States)

Love, Brian

2004-01-01

An attempt is made to find a solution to the occasional problem of a need for storing large numbers of graduated cylinders in many teaching and research laboratories. A design, which involves the creation of a series of parallel channels that are used to suspend inverted graduated cylinders by their bases, is proposed.

A constant-density Gurney approach to the Cylinder test

Energy Technology Data Exchange (ETDEWEB)

Reaugh, John E.; Souers, P. Clark [Energetic Materials Center, Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)

2004-04-01

The previous analysis of the Cylinder test required the treatment of different wall thicknesses and wall materials separately. To fix this, the Gurney analysis is used, but this results in low values for full-wall standard, ideal explosives relative to CHEETAH analyses. A new constant metal-density model is suggested, which takes account of the thinning metal wall as the cylinder expands. With this model, the inner radius of the metal cylinder moves faster than the measured outer radius. Additional small corrections occur in all cylinders because of energy trapped in the copper walls. Also, the half-wall cylinders have a small correction because the relative volumes of the gas products are smaller at a given outside wall displacement. The Fabry-Perot and streak camera measurements are compared. The Fabry method is shown to equate to the constant density model. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

Investigation on carbon nanomaterials: Coaxial CNT-cylinders and ...

Indian Academy of Sciences (India)

Wintec

carbon cylinders of CNT stacks have been formed directly inside the quartz tube. Another study is ... producing CNTs have been devised including electric arc evaporation ... process of coaxial carbon cylinder have already been de- scribed by ...

Adaptive individual-cylinder thermal state control using piston cooling for a GDCI engine

Science.gov (United States)

Roth, Gregory T; Husted, Harry L; Sellnau, Mark C

2015-04-07

A system for a multi-cylinder compression ignition engine includes a plurality of nozzles, at least one nozzle per cylinder, with each nozzle configured to spray oil onto the bottom side of a piston of the engine to cool that piston. Independent control of the oil spray from the nozzles is provided on a cylinder-by-cylinder basis. A combustion parameter is determined for combustion in each cylinder of the engine, and control of the oil spray onto the piston in that cylinder is based on the value of the combustion parameter for combustion in that cylinder. A method for influencing combustion in a multi-cylinder engine, including determining a combustion parameter for combustion taking place in in a cylinder of the engine and controlling an oil spray targeted onto the bottom of a piston disposed in that cylinder is also presented.

Prediction of External Corrosion for Steel Cylinders--2002 Report

International Nuclear Information System (INIS)

Schmoyer, RLS

2002-01-01

The United States Department of Energy (DOE) manages the UF 6 Cylinder Project. The project was formed to maintain and safely manage the depleted uranium hexafluoride (UF 6 ) stored in approximately 50,000 carbon steel cylinders. The cylinders are located at three DOE sites: the East Tennessee Technology Park (ETTP) site in Oak Ridge, Tennessee; the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky, and the Portsmouth Gaseous Diffusion Plant (PORTS) in Portsmouth, Ohio. The System Requirements Document (SRD) (LMES 1997a) delineates the requirements of the project, and the actions needed to fulfill these requirements are specified in the System Engineering Management Plan (SEMP) (LMES 1997b). This report documents activities that in whole or part satisfy specific requirements and actions stated in the UF 6 Cylinder Project SRD and SEMP with respect to forecasting cylinder conditions. The results presented here supercede those presented by Lyon (1995, 1996, 1997, 1998, 2000), and Schmoyer and Lyon (2001). Many of the wall thickness projections made in this report are conservative, because they are based on the assumption that corrosion trends will continue, despite activities such as improved monitoring, relocations to better storage, painting, and other improvements in storage conditions relative to the conditions at the times most of the wall thickness measurements were made. For thin-wall cylinders (design nominal wall thickness 312.5 mils), the critical minimum wall thicknesses criteria used in this report are 0 (breach), 62.5 mils, and 250 mils (1 mil = 0.001 in.). For thick-wall cylinders (design nominal wall thickness 625 mils), the thickness criteria used in this report are 0, 62.5 mils, and 500 mils. The criteria triples are preliminary boundaries identified within the project that indicate (1) loss of material (UF 6 ), (2) safe handling and stacking operations, and (3) standards for off-site transport and contents transfer criteria, respectively

Processing of mixed-waste compressed-gas cylinders on the Oak Ridge Reservation

International Nuclear Information System (INIS)

Morris, M.I.; Conley, T.B.; Osborne-Lee, I.W.

1998-03-01

To comply with restrictions on the storage of old compressed gas cylinders, the environmental management organization of Lockheed Martin Energy Systems must dispose of several thousand kilograms of compressed gases stored on the Oak Ridge Reservation (ORR) because the cylinders cannot be taken off-site for disposal in their current configuration. In the ORR Site Treatment Plan, a milestone is cited that requires repackaging and shipment off-site of 21 cylinders by September 30, 1997. A project was undertaken to first evaluate and then either recontainerize or neutralize these cylinders using a transportable compressed gas recontainerization skid (TCGRS), which was developed by Integrated Environmental Services of Atlanta. The transportable system can: (1) sample, analyze, and identify at the site the chemical and radiological content of each cylinder, even those with inoperable valves; (2) breach cylinders, when necessary, to release their contents into a containment chamber; and (3) either neutralize the gas or liquid contents within the containment chamber or transfer the gas or liquids to a new cylinder. The old cylinders and cylinder fragments were disposed of and the gases neutralized or transferred to new cylinders for transportation off-site for disposal. The entire operation to process the 21 cylinders took place in only 5 days once the system was approved for operation. The system performed as expected and can now be used to process the potentially thousands of more cylinders located across the US Department of Energy (DOE) complex that have not yet been declared surplus

Vortex shedding control of circular cylinder by perforated shroud in deep water

Directory of Open Access Journals (Sweden)

Ozkan Gokturk M.

2017-01-01

Full Text Available The aim of the present study is to control the vortex shedding downstream of a circular cylinder (inner cylinder by the existence of outer perforated cylinder concentrically located around the inner cylinder in deep water. The flow characteristics downstream of concentrically placed coupled cylinders were investigated quantitatively by the Particle Image Velocimetry (PIV technique. Diameter of the outer perforated cylinder and inner cylinder were kept constant as Do=100 mm and Di=50 mm. The depth-averaged free-stream velocity was also kept constant as U=100 mm/s which corresponded to the Reynolds number of ReDo=10,000 based on the outer cylinder diameter. Experiments were conducted for six porosities (β = 0.3, 0.4, 0.5, 0.6, 0.7 and 0.8 in order to show the effect of these parameters on the flow control. Maximum values of both Reynolds shear stress, and turbulence kinetic energy, significantly decreased with the existence of outer perforated cylinder and also, the location of peak magnitudes of turbulence statistics occurred at locations further downstream compared to the bare cylinder case. The most effective control was revealed for the porosity of β=0.7.

Vortex shedding control of circular cylinder by perforated shroud in deep water

Science.gov (United States)

Ozkan, Gokturk M.; Durhasan, Tahir; Pinar, Engin; Aksoy, Muhammed M.; Akilli, Huseyin; Sahin, Beşir

The aim of the present study is to control the vortex shedding downstream of a circular cylinder (inner cylinder) by the existence of outer perforated cylinder concentrically located around the inner cylinder in deep water. The flow characteristics downstream of concentrically placed coupled cylinders were investigated quantitatively by the Particle Image Velocimetry (PIV) technique. Diameter of the outer perforated cylinder and inner cylinder were kept constant as Do=100 mm and Di=50 mm. The depth-averaged free-stream velocity was also kept constant as U=100 mm/s which corresponded to the Reynolds number of ReDo=10,000 based on the outer cylinder diameter. Experiments were conducted for six porosities (β = 0.3, 0.4, 0.5, 0.6, 0.7 and 0.8) in order to show the effect of these parameters on the flow control. Maximum values of both Reynolds shear stress, and turbulence kinetic energy, significantly decreased with the existence of outer perforated cylinder and also, the location of peak magnitudes of turbulence statistics occurred at locations further downstream compared to the bare cylinder case. The most effective control was revealed for the porosity of β=0.7.

AFM tip-sample convolution effects for cylinder protrusions

Science.gov (United States)

Shen, Jian; Zhang, Dan; Zhang, Fei-Hu; Gan, Yang

2017-11-01

A thorough understanding about the AFM tip geometry dependent artifacts and tip-sample convolution effect is essential for reliable AFM topographic characterization and dimensional metrology. Using rigid sapphire cylinder protrusions (diameter: 2.25 μm, height: 575 nm) as the model system, a systematic and quantitative study about the imaging artifacts of four types of tips-two different pyramidal tips, one tetrahedral tip and one super sharp whisker tip-is carried out through comparing tip geometry dependent variations in AFM topography of cylinders and constructing the rigid tip-cylinder convolution models. We found that the imaging artifacts and the tip-sample convolution effect are critically related to the actual inclination of the working cantilever, the tip geometry, and the obstructive contacts between the working tip's planes/edges and the cylinder. Artifact-free images can only be obtained provided that all planes and edges of the working tip are steeper than the cylinder sidewalls. The findings reported here will contribute to reliable AFM characterization of surface features of micron or hundreds of nanometers in height that are frequently met in semiconductor, biology and materials fields.

Effect of Surface Coatings on Cylinders Exposed to Underwater Shock

Directory of Open Access Journals (Sweden)

Y.W. Kwon

1994-01-01

Full Text Available The response of a coated cylinder (metallic cylinder coated with a rubber material subjected to an underwater explosion is analyzed numerically. The dynamic response of the coated cylinder appears to be adversely affected when impacted by an underwater shock wave under certain conditions of geometry and material properties of the coating. When adversely affected, significant deviations in values of axial stress, hoop stress, and strain are observed. The coated cylinder exhibits a larger deformation and higher internal energy in the metallic material. Rubber coatings appeared to inhibit energy dissipation from the metallic material to the surrounding water medium. A parametric study of various coatings was performed on both aluminum and steel cylinders. The adverse effect of the coating decreased when the stiffness of the rubber layer increased, indicating the existence of a threshold value. The results of this study indicate that the stiffness of the coating is a critical factor to the shock hardening of the coated cylinder.

Long-term storage of compressed radioactive krypton in cylinders

International Nuclear Information System (INIS)

Niephaus, D.; Nommensen, O.; Bruecher, H.

1982-01-01

The recommendations of the German Radiation Protection Commission necessitate the separation of the radioactive noble gas krypton-85 (Kr-85) produced in large LWR reprocessing plants from the dissolver off-gas. A possible method of removal is a long-term storage of the compressed noble gas above ground in cylinders. The aim of the present study is to develop such a storage concept and evaluate its feasibility under the aspects of safety and cost. After having been filled, the gas cylinders are placed separately into transport racks serving to protect the cylinders. Following this, the cylinders are transferred out of the filling station in a transport cask, conveyed to the storage building and stored there. The storage building protects the gas cylinders against external impacts. The storage cells constitute a second barrier against the release of Kr-85. The heat produced during decay of the Kr-85 in the gas cylinders is carried off by natural convection of the air circulating in the storage cells. To study possible corrosion attack on special steels due to rubidium, experiments were conducted at 200 0 C during test periods up to 3500h. In order to compare properties at elevated temperatures, corrosion experiments were conducted at 500 0 C, which is far above the maximum licensed storage temperature of 200 0 C. Experiments were conducted concerning the adsorption of krypton on various adsorbents, thus reducing the pressure inside the gas cylinder during storage. A cost estimate based on 1980 prices

Effect of High Porosity Screen on the Near Wake of a Circular Cylinder

Directory of Open Access Journals (Sweden)

Sahin B.

2013-04-01

Full Text Available The change in flow characteristics downstream of a circular cylinder (inner cylinder surrounded by a permeable cylinder (outer cylinder made of a high porosity screen was investigated in shallow water using Particle Image Velocimetry (PIV technique. The diameter of the inner cylinder, outer cylinder and the water height were kept constant during the experiments as d = 50 mm, D = 100 mm and hw = 50 mm, respectively. The depth-averaged free stream velocity was also kept constant as U = 180 mm/s which corresponded to a Reynolds number of Red = 9000 based on the inner cylinder diameter. It was shown that the outer permeable cylinder had a substantialeffect on the vortex formation and consequent vortex shedding downstream of the circular cylinder, especially in the near wake. The time averaged vorticity layers, streamlines and velocity vector field depict that the location of the interaction of vortices considerably changed by the presence of the outer cylinder. Turbulent statistics clearly demonstrated that in comparison to the natural cylinder, turbulent kinetic energy and Reynolds stresses decreased remarkably downstream of the inner cylinder. Moreover, spectra of streamwise velocity fluctuations showed that the vortex shedding frequency significantly reduced compared to the natural cylinder case.

A New Wavelet-Based ECG Delineator for the Evaluation of the Ventricular Innervation

DEFF Research Database (Denmark)

Cesari, Matteo; Mehlsen, Jesper; Mehlsen, Anne-Birgitte

2017-01-01

T-wave amplitude (TWA) has been proposed as a marker of the innervation of the myocardium. Until now, TWA has been calculated manually or with poor algorithms, thus making its use not efficient in a clinical environment. We introduce a new wavelet-based algorithm for the delineation QRS complexes...

49 CFR 180.205 - General requirements for requalification of specification cylinders.

Science.gov (United States)

2010-10-01

... each cylinder tested, except that for an analog device, interpolation to 1/2 of the marked gauge... for training persons who requalify cylinders using the volumetric expansion test method. (h) Cylinder...

EVOLUTION OF NEUROENDOCRINE CELL POPULATION AND PEPTIDERGIC INNERVATION, ASSESSED BY DISCRIMINANT ANALYSIS, DURING POSTNATAL DEVELOPMENT OF THE RAT PROSTATE

Directory of Open Access Journals (Sweden)

Rosario Rodríguez

2011-05-01

Full Text Available Serotonin immunoreactive neuroendocrine cells and peptidergic nerves (NPY and VIP could have a role in prostate growth and function. In the present study, rats grouped by stages of postnatal development (prepubertal, pubertal, young and aged adults were employed in order to ascertain whether age causes changes in the number of serotoninergic neuroendocrine cells and the length of NPY and VIP fibres. Discriminant analysis was performed in order to ascertain the classificatory power of stereologic variables (absolute and relative measurements of cell number and fibre length on age groups. The following conclusions were drawn: a discriminant analysis confirms the androgen-dependence of both neuroendocrine cells and NPYVIP innervation during the postnatal development of the rat prostate; b periglandular innervation has more relevance than interglandular innervation in classifying the rats in age groups; and c peptidergic nerves from ventral, ampullar and periductal regions were more age-dependent than nerves from the dorso-lateral region.

Influence of psychomotor skills and innervation patterns on results of latissimus dorsi tendon transfer for irreparable rotator cuff tears.

Science.gov (United States)

Werner, Clément M L; Ruckstuhl, Thomas; Müller, Roland; Zanetti, Marco; Gerber, Christian

2008-01-01

This investigation was performed to analyze the influence of innervation and psychomotor skills on the outcome of latissimus dorsi transfer. Patients with the 10 best and 10 worst results after latissimus dorsi transfer for irreparable rotator cuff tears were selected. All patients meeting the inclusion criteria (n = 12) were subject to a psychomotor test battery (Motorische Leistungsserie) and electromyographic innervation assessment. There was no statistical difference between the 2 groups preoperatively in terms of the commonly tested factors known to influence the results of this procedure adversely. There was a significant difference in both the pattern and selectivity of innervation in the group that had better clinical results. The psychomotor findings were negatively correlated with the range of motion and the strength of the operative shoulder. Function of the operative shoulder could also be predicted by psychomotor function of the uninjured contralateral side. Psychomotor skills testing appears to be a new, potential method by which to predict the outcome of latissimus dorsi transfer.

Plane Wall Effect of Flow around Two Circular Cylinders in Tandem Arrangement

Directory of Open Access Journals (Sweden)

Triyogi Yuwono,

2011-02-01

Full Text Available The flow characteristic around two circular cylinders in tandem arrangement located near a plane wall were investigated experimentally in a uniform flow at a Reynolds Number of 5.3 x 104. The center to center spacing between the two cylinders relative to the cylinder diameter was constantly maintained at P/D = 1.5. The pressure distributions along the surface of the cylinder and the plane wall were measured by varying the gap-to-diameter of cylinder ratio (G/D in the range of 0 < G/D < 0.467. Surface oil-film techniques were used to investigate the flow patterns on the cylinder. The result showed that for upstream cylinder, in the gap-to-diameter ratio G/D < /D, there is no stagnation point at front side of the upstream cylinder; it is gradually raised as the gap increase. For the downstream cylinder, a peak on the lower side of the front side of the cylinder is apparent in each of the pressure distributions. This peak represents the reattachment of shear layer that separates from lower side of the upstream cylinder. The reattachment point tends to move forward close to the angular position of  = 0o as the gap ratio increase. The shear layer bifurcates into two shear layers. One shear layer continues in the downstream direction, and the other shear layer flows in the upstream direction.

UF6 Cylinder Imaging by Fast Neutron Transmission Tomography

International Nuclear Information System (INIS)

McElroy, R.; Hausladen, P.; Blackston, M.; Croft, S.

2015-01-01

The common use Non-Destructive Assay techniques for the determination of 235 U enrichment and mass of UF6 cylinders used in the production of nuclear reactor fuel require prior knowledge of the physical distribution of the UF6 within the cylinder. The measurement performance for these techniques is typically evaluated based on assumed bounding case distributions of the material. However, little direct data such as radiographic or tomographic images, regarding the distribution of the UF6 within the cylinder is available against which to judge these assumptions. We have developed and tested a prototype active neutron tomographic imaging system employing an Associated Particle Imaging (API) neutron generator and an array of pixelated neutron scintillation counters. This system has been successfully used to obtain the 3-dimensional map of the distribution of UF6 within a type 12B storage cylinder. Results from these measurements are presented and the potential performance and utility of this technique with larger 30B and 48Y cylinders is discussed. (author)

Experimental study on flow past a rotationally oscillating cylinder

Science.gov (United States)

Gao, Yang-yang; Yin, Chang-shan; Yang, Kang; Zhao, Xi-zeng; Tan, Soon Keat

2017-08-01

A series of experiments was carried out to study the flow behaviour behind a rotationally oscillating cylinder at a low Reynolds number (Re=300) placed in a recirculation water channel. A stepper motor was used to rotate the cylinder clockwise- and- counterclockwise about its longitudinal axis at selected frequencies. The particle image velocimetry (PIV) technique was used to capture the flow field behind a rotationally oscillating cylinder. Instantaneous and timeaveraged flow fields such as the vorticity contours, streamline topologies and velocity distributions were analyzed. The effects of four rotation angle and frequency ratios F r ( F r= f n/ f v, the ratio of the forcing frequency f n to the natural vortex shedding frequency f v) on the wake in the lee of a rotationally oscillating cylinder were also examined. The significant wake modification was observed when the cylinder undergoes clockwise-and-counterclockwise motion with amplitude of π, especially in the range of 0.6≤ F r≤1.0.

Adaptive individual-cylinder thermal state control using intake air heating for a GDCI engine

Science.gov (United States)

Roth, Gregory T.; Sellnau, Mark C.

2016-08-09

A system for a multi-cylinder compression ignition engine includes a plurality of heaters, at least one heater per cylinder, with each heater configured to heat air introduced into a cylinder. Independent control of the heaters is provided on a cylinder-by-cylinder basis. A combustion parameter is determined for combustion in each cylinder of the engine, and control of the heater for that cylinder is based on the value of the combustion parameter for combustion in that cylinder. A method for influencing combustion in a multi-cylinder compression ignition engine, including determining a combustion parameter for combustion taking place in a cylinder of the engine and controlling a heater configured to heat air introduced into that cylinder, is also provided.

Cracked lifting lug welds on ten-ton UF{sub 6} cylinders

Energy Technology Data Exchange (ETDEWEB)

Dorning, R.E. [Martin Marietta Energy Systems, Inc., Piketon, OH (United States)

1991-12-31

Ten-ton, Type 48X, UF{sub 6} cylinders are used at the Portsmouth Gaseous Diffusion Plant to withdraw enriched uranium hexafluoride from the cascade, transfer enriched uranium hexafluoride to customer cylinders, and feed enriched product to the cascade. To accomplish these activities, the cylinders are lifted by cranes and straddle carriers which engage the cylinder lifting lugs. In August of 1988, weld cracks on two lifting lugs were discovered during preparation to lift a cylinder. The cylinder was rejected and tagged out, and an investigating committee formed to determine the cause of cracking and recommend remedial actions. Further investigation revealed the problem may be general to this class of cylinder in this use cycle. This paper discusses the actions taken at the Portsmouth site to deal with the cracked lifting lug weld problem. The actions include inspection activities, interim corrective actions, metallurgical evaluation of cracked welds, weld repairs, and current monitoring/inspection program.

Differential serotonergic innervation of the amygdala in bonobos and chimpanzees.

Science.gov (United States)

Stimpson, Cheryl D; Barger, Nicole; Taglialatela, Jared P; Gendron-Fitzpatrick, Annette; Hof, Patrick R; Hopkins, William D; Sherwood, Chet C

2016-03-01

Humans' closest living relatives are bonobos (Pan paniscus) and chimpanzees (Pan troglodytes), yet these great ape species differ considerably from each other in terms of social behavior. Bonobos are more tolerant of conspecifics in competitive contexts and often use sexual behavior to mediate social interactions. Chimpanzees more frequently employ aggression during conflicts and actively patrol territories between communities. Regulation of emotional responses is facilitated by the amygdala, which also modulates social decision-making, memory and attention. Amygdala responsiveness is further regulated by the neurotransmitter serotonin. We hypothesized that the amygdala of bonobos and chimpanzees would differ in its neuroanatomical organization and serotonergic innervation. We measured volumes of regions and the length density of serotonin transporter-containing axons in the whole amygdala and its lateral, basal, accessory basal and central nuclei. Results showed that accessory basal nucleus volume was larger in chimpanzees than in bonobos. Of particular note, the amygdala of bonobos had more than twice the density of serotonergic axons than chimpanzees, with the most pronounced differences in the basal and central nuclei. These findings suggest that variation in serotonergic innervation of the amygdala may contribute to mediating the remarkable differences in social behavior exhibited by bonobos and chimpanzees. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Development of cardiac parasympathetic neurons, glial cells, and regional cholinergic innervation of the mouse heart.

Science.gov (United States)

Fregoso, S P; Hoover, D B

2012-09-27

Very little is known about the development of cardiac parasympathetic ganglia and cholinergic innervation of the mouse heart. Accordingly, we evaluated the growth of cholinergic neurons and nerve fibers in mouse hearts from embryonic day 18.5 (E18.5) through postnatal day 21(P21). Cholinergic perikarya and varicose nerve fibers were identified in paraffin sections immunostained for the vesicular acetylcholine transporter (VAChT). Satellite cells and Schwann cells in adjacent sections were identified by immunostaining for S100β calcium binding protein (S100) and brain-fatty acid binding protein (B-FABP). We found that cardiac ganglia had formed in close association to the atria and cholinergic innervation of the atrioventricular junction had already begun by E18.5. However, most cholinergic innervation of the heart, including the sinoatrial node, developed postnatally (P0.5-P21) along with a doubling of the cross-sectional area of cholinergic perikarya. Satellite cells were present throughout neonatal cardiac ganglia and expressed primarily B-FABP. As they became more mature at P21, satellite cells stained strongly for both B-FABP and S100. Satellite cells appeared to surround most cardiac parasympathetic neurons, even in neonatal hearts. Mature Schwann cells, identified by morphology and strong staining for S100, were already present at E18.5 in atrial regions that receive cholinergic innervation at later developmental times. The abundance and distribution of S100-positive Schwann cells increased postnatally along with nerve density. While S100 staining of cardiac Schwann cells was maintained in P21 and older mice, Schwann cells did not show B-FABP staining at these times. Parallel development of satellite cells and cholinergic perikarya in the cardiac ganglia and the increase in abundance of Schwann cells and varicose cholinergic nerve fibers in the atria suggest that neuronal-glial interactions could be important for development of the parasympathetic nervous

Guided Circumferential Waves in Layered Poroelastic Cylinders

Directory of Open Access Journals (Sweden)

Shah S.A.

2016-12-01

Full Text Available The present paper investigates the propagation of time harmonic circumferential waves in a two-dimensional hollow poroelastic cylinder with an inner shaft (shaft-bearing assembly. The hollow poroelastic cylinder and inner shaft are assumed to be infinite in axial direction. The outer surface of the cylinder is stress free and at the interface, between the inner shaft and the outer cylinder, it is assumed to be free sliding and the interfacial shear stresses are zero, also the normal stress and radial displacements are continuous. The frequency equation of guided circumferential waves for a permeable and an impermeable surface is obtained. When the angular wave number vanish the frequency equation of guided circumferential waves for a permeable and an impermeable surface degenerates and the dilatational and shear waves are uncoupled. Shear waves are independent of the nature of surface. The frequency equation of a permeable and an impermeable surface for bore-piston assembly is obtained as a particular case of the model under consideration when the outer radius of the hollow poroelastic cylinder tends to infinity. Results of previous studies are obtained as a particular case of the present study. Nondimensional frequency as a function of wave number is presented graphically for two types of models and discussed. Numerical results show that, in general, the first modes are linear for permeable and impermeable surfaces and the frequency of a permeable surface is more than that of an impermeable surface.

Aesthetic and Functional Outcomes of the Innervated and Thinned Anterolateral Thigh Flap in Reconstruction of Upper Limb Defects

Directory of Open Access Journals (Sweden)

Carlos Alberto Torres-Ortíz Zermeño

2014-01-01

Full Text Available Background. The anterolateral thigh (ALT flap has been widely described in reconstruction of the upper extremity. However, some details require refinement to improve both functional and aesthetic results. Methods. After reconstruction of upper extremity defects using thinned and innervated ALT flaps, functional and aesthetic outcomes were evaluated with the QuickDASH scale and a Likert scale for aesthetic assessment of free flaps, respectively. Results. Seven patients with a mean follow-up of 11.57 months and average flap thickness of 5 mm underwent innervation by an end-to-end neurorrhaphy. The average percentage of disability (QuickDASH was 21.88% with tenderness, pain, temperature, and two-point discrimination present in 100% of cases, and the aesthetic result gave an overall result of 15.40 (good with the best scores in color and texture. Conclusions. Simultaneous thinning and innervation of the ALT flap lead to a good cosmetic result and functional outcome with a low percentage of disability, which could result in minor surgical procedures and better recovery of motor and sensory function. Level of Evidence. IV.

Processing mixed-waste compressed-gas cylinders at the Oak Ridge Reservation

International Nuclear Information System (INIS)

Morris, M.I.; Conley, T.B.; Osborne-Lee, I.W.

1998-05-01

Until recently, several thousand kilograms of compressed gases were stored at the Oak Ridge Reservation (ORR), in Oak Ridge, Tennessee, because these cylinders could not be taken off-site in their state of configuration for disposal. Restrictions on the storage of old compressed-gas cylinders compelled the Waste Management Organization of Lockheed Martin Energy Systems, Inc. (LMES) to dispose of these materials. Furthermore, a milestone in the ORR Site Treatment Plan required repackaging and shipment off-site of 21 cylinders by September 30, 1997. A pilot project, coordinated by the Chemical Technology Division (CTD) at the Oak Ridge National Laboratory (ORNL), was undertaken to evaluate and recontainerize or neutralize these cylinders, which are mixed waste, to meet that milestone. Because the radiological component was considered to be confined to the exterior of the cylinder, the contents (once removed from the cylinder) could be handled as hazardous waste, and the cylinder could be handled as low-level waste (LLW). This pilot project to process 21 cylinders was important because of its potential impact. The successful completion of the project provides a newly demonstrated technology which can now be used to process the thousands of additional cylinders in inventory across the DOE complex. In this paper, many of the various aspects of implementing this project, including hurdles encountered and the lessons learned in overcoming them, are reported

Low-cost, low-weight CNG cylinder development. Final report

Energy Technology Data Exchange (ETDEWEB)

Richards, Mark E.; Melford, K.; Wong, J.; Gambone, L.

1999-09-01

This program was established to develop and commercialize new high-strength steel-lined, composite hoop-wrapped compressed natural gas (CNG) cylinders for vehicular applications. As much as 70% of the cost of natural gas vehicles can be related to on-board natural gas storage costs. The cost and weight targets for this program represent significant savings in each characteristic when compared to comparable containers available at the initiation of the program. The program objectives were to optimize specific weight and cost goals, yielding CNG cylinders with dimensions that should, allowing for minor modifications, satisfy several vehicle market segments. The optimization process encompassed material, design, and process improvement. In optimizing the CNG cylinder design, due consideration was given to safety aspects relative to national, international, and vehicle manufacturer cylinder standards and requirements. The report details the design and development effort, encompassing plant modifications, material selection, design issues, tooling development, prototype development, and prototype testing. Extenuating circumstances prevented the immediate commercialization of the cylinder designs, though significant progress was made towards improving the cost and performance of CNG cylinders. A new low-cost fiber was successfully employed while the weight target was met and the cost target was missed by less than seven percent.

The spatiotemporal development of innervation in spinal ligaments of chickens.

OpenAIRE

Jiang, H; Moreau, M; Greidanus, N; Bilo, J; Russell, G; Raso, J; Bagnall, K

1996-01-01

The development of the innervation of both central and lateral (intertransverse) spinal ligaments was investigated in chickens between the time of hatching and 13 wk of age. A total of 36 White Leghorn chickens in 4 groups of 9 at ages 0, 2, 7, and 13 wk were used. The spinal ligaments were dissected, serially sectioned and labelled with a monoclonal antibody against neurofilament protein and observed using either conventional fluorescence or confocal microscopy. Only a few nerve elements wer...

The role of the autonomic nervous liver innervation in the control of energy metabolism

NARCIS (Netherlands)

Yi, Chun-Xia; la Fleur, Susanne E.; Fliers, Eric; Kalsbeek, Andries

2010-01-01

Despite a longstanding research interest ever since the early work by Claude Bernard, the functional significance of autonomic liver innervation, either sympathetic or parasympathetic, is still ill defined. This scarcity of information not only holds for the brain control of hepatic metabolism, but

Convective heat transfer from a heated elliptic cylinder at uniform wall temperature

Energy Technology Data Exchange (ETDEWEB)

Kaprawi, S.; Santoso, Dyos [Mechanical Department of Sriwijaya University, Jl. Raya Palembang-Prabumulih Km. 32 Inderalaya 50062 Ogan Ilir (Indonesia)

2013-07-01

This study is carried out to analyse the convective heat transfer from a circular and an elliptic cylinders to air. Both circular and elliptic cylinders have the same cross section. The aspect ratio of cylinders range 0-1 are studied. The implicit scheme of the finite difference is applied to obtain the discretized equations of hydrodynamic and thermal problem. The Choleski method is used to solve the discretized hydrodynamic equation and the iteration method is applied to solve the discretized thermal equation. The circular cylinder has the aspect ratio equal to unity while the elliptical cylinder has the aspect ratio less than unity by reducing the minor axis and increasing the major axis to obtain the same cross section as circular cylinder. The results of the calculations show that the skin friction change significantly, but in contrast with the elliptical cylinders have greater convection heat transfer than that of circular cylinder. Some results of calculations are compared to the analytical solutions given by the previous authors.

The sympathetic innervation of the heart: Important new insights.

Science.gov (United States)

Coote, J H; Chauhan, R A

2016-08-01

Autonomic control of the heart has a significant influence over development of life threatening arrhythmias that can lead to sudden cardiac death. Sympathetic activity is known to be upregulated during these conditions and hence the sympathetic nerves present a target for treatment. However, a better understanding of the anatomy and physiology of cardiac sympathetic nerves is required for the progression of clinical interventions. This review explores the organization of the cardiac sympathetic nerves, from the preganglionic origin to the postganglionic innervations, and provides an overview of literature surrounding anti-arrhythmic therapies including thoracic sympathectomy and dorsal spinal cord stimulation. Several features of the innervation are clear. The cardiac nerves differentially supply the nodal and myocardial tissue of the heart and are dependent on activity generated in spinal neurones in the upper thoracic cord which project to synapse with ganglion cells in the stellate complex on each side. Networks of spinal interneurones determine the pattern of activity. Groups of spinal neurones selectively target specific regions of the heart but whether they exhibit a functional selectivity has still to be elucidated. Electrical or ischemic signals can lead to remodeling of nerves in the heart or ganglia. Surgical and electrical methods are proving to be clinically beneficial in reducing atrial and ventricular arrhythmias, heart failure and severe cardiac pain. This is a rapidly developing area and we need more basic understanding of how these methods work to ensure safety and reduction of side effects. Copyright © 2016 Elsevier B.V. All rights reserved.

Cylinder gauge measurement using a position sensitive detector

International Nuclear Information System (INIS)

St John, W. Doyle

2007-01-01

A position sensitive detector (PSD) has been used to determine the diameter of cylindrical pins based on the shift in a laser beam's centroid. The centroid of the light beam is defined here as the weighted average of position by the local intensity. A shift can be observed in the centroid of an otherwise axially symmetric light beam, which is partially obstructed. Additionally, the maximum shift in the centroid is a unique function of the obstructing cylinder diameter. Thus to determine the cylinder diameter, one only needs to detect this maximum shift as the cylinder is swept across the beam

Experimental and finite element prediction of bursting pressure in compound cylinders

International Nuclear Information System (INIS)

Majzoobi, G.H.; Farrahi, G.H.; Pipelzadeh, M.K.; Akbari, A.

2004-01-01

Aluminium cylinders with a constant ratio of outer to inner radii, k=2.2, with different diametral interferences and various shrinkage radii were subjected to bursting and autofrettage pressures. Numerical simulations of the compound cylinders were also performed using the finite element code, NISA. The results can predict the optimum shrinkage radius to a reasonable accuracy with the use of finite element analysis. This radius corresponds to the situation when the maximum von-Mises stress at the internal radii of both the inner and outer cylinders become equal. It was shown that the maximum von-Mises stress across the wall of the cylinder is at the minimum at this shrinkage radius. The optimum diametral interference was found to be that which sufficiently brought the contact surface of the inner and outer cylinders to the point of yielding. Should the shrinkage pressure exceed the elastic limit, the pressure capacity of the cylinder will not be improved. The numerical and experimental results show that autofrettage had no effect on the bursting pressure of the thick-walled compound cylinder for the material tested

PIV Measurements of He II Counterflow Around a Cylinder

International Nuclear Information System (INIS)

Fuzier, S.; Van Stiver, S. W.; Zhang, T.

2006-01-01

The induced flow field of counterflow He II across a circular cylinder has been quantitatively studied using the particle image velocimetry (PIV) technique. Two different size cylinders (6.35 mm and 2 mm in diameter) were used and placed in a 20 mm wide rectangular channel. In these experiments, large-scale eddy motion generated by the He II counterflow was observed both in front of and behind the cylinder, an effect which has no analogue in classical fluids

Preliminary Concept of Operations for a Global Cylinder Identification and Monitoring System

Energy Technology Data Exchange (ETDEWEB)

Whitaker, J. M. [ORNL; White-Horton, J. L. [ORNL; Morgan, J. B. [InSolves Associates

2013-08-01

This report describes a preliminary concept of operations for a Global Cylinder Identification and Monitoring System that could improve the efficiency of the International Atomic Energy Agency (IAEA) in conducting its current inspection activities and could provide a capability to substantially increase its ability to detect credible diversion scenarios and undeclared production pathways involving UF6 cylinders. There exist concerns that a proliferant State with access to enrichment technology could obtain a cylinder containing natural or low-enriched uranium hexafluoride (UF6) and produce a significant quantity (SQ)1 of highly enriched uranium in as little as 30 days. The National Nuclear Security Administration (NNSA) through the Next Generation Safeguards Initiative sponsored a multi-laboratory team to develop an integrated system that provides for detecting scenarios involving 1) diverting an entire declared cylinder for enrichment at a clandestine facility, 2) misusing a declared cylinder at a safeguarded facility, and 3) using an undeclared cylinder at a safeguarded facility. An important objective in developing this integrated system was to improve the timeliness for detecting the cylinder diversion and undeclared production scenarios. Developing this preliminary concept required in-depth analyses of current operational and safeguards practices at conversion, enrichment, and fuel fabrication facilities. The analyses evaluated the processing, movement, and storage of cylinders at the facilities; the movement of cylinders between facilities (including cylinder fabrication); and the misuse of safeguarded facilities.

Bursting pressure of autofrettaged cylinders with inclined external cracks

International Nuclear Information System (INIS)

Seifi, Rahman; Babalhavaeji, Majid

2012-01-01

Autofrettaging a pressure vessel improves its pressure capacity. This is reliable if there isn’t any crack or other type of flaws. In this paper, the effects of external surface cracks on bursting pressure of autofrettaged cylinders are studied. It is observed that bursting pressure decreases considerably (up to 30%) due to external cracks in the cylinders without autofrettage. This reduction increases for high levels of the applied autofrettage. External axial cracks have more effects than inclined cracks. Comparing experimental and numerical results show that the numerical methods can acceptably predict the bursting pressure of the autofrettaged cracked cylinders. These predictions are valid when the fracture parameter (J-Integral) is calculated from the modified equation that takes into account the effects of residual stresses. - Highlights: ► Modified J-Integral can be used for study of autofrettaged cracked cylinders. ► External axial cracks reduce considerably the pressure capacity of cylinders. ► External circumferential cracks have not considerable effects on bursting pressure. ► Autofrettage has contrary effects on external crack in compared with internal crack.

A numerical simulation of VIV on a flexible circular cylinder

International Nuclear Information System (INIS)

Xie Fangfang; Deng Jian; Zheng Yao; Xiao Qing

2012-01-01

In this paper, numerical simulations of a flexible circular cylinder subjected to a vortex-induced vibration (VIV) are conducted. The Reynolds number for simulations is fixed at 1000. The finite volume method is applied for modeling fluid flow with the moving meshes feature. The dynamic response of a flexible cylinder fixed at both ends is modeled by the Euler–Bernoulli beam theory. The comparison between two-dimensional (2D) simulations and 3D simulations for the flexible cylinder shows that the maximum response amplitude of the cross-flow oscillation is about 0.57D for 2D rigid cylinders (modeled by a spring–damper–mass model) and 1.03D for flexible cylinders, respectively. The results from 3D simulations are closer to previous experimental results. Furthermore, the results obtained with various frequency ratios show that different wake patterns exist according to the frequency ratio, such as 2S mode, 2P mode and some more complicated modes. The wake pattern is different at various sections along the cylinder length, due to the fact that the two ends of the beam are fixed. The vibration of the flexible cylinder can also greatly alter the three dimensionality in the wake, which is our research in future work, especially in the transition region for Reynolds number ranging from 170 to 300. (paper)

Surface flaw in a thermally shocked hollow cylinder

International Nuclear Information System (INIS)

Kobayashi, A.S.; Emery, A.F.; Polvanich, N.; Love, W.J.

1975-01-01

The objective of this paper is to illustrate a procedure for estimating the stress intensity factors of a semi-elliptical crack located in the inner or outer surface of a thermally shocked hollow cylinder. The first step in this procedure is to estimate the transient thermal elastic stresses induced by sudden cooling of an uncracked cylinder by numerically evaluating standard heat transfer and thermal stress formulae. The stresses at the location of the crack surface in the uncracked cylinder are eliminated by the method of superposition in order to obtain a stress free crack surface. The stress intensity factors are then determined by a judicious use of two sets of solutions, one set involving stress intensity factors for a semi-elliptical crack in a flat plate and subjected to a polynomial distribution of pressure loading, and another set involving single-edge notched plates with prescribed edge-displacements and single-edge internally or externally notched cylinders with thermal shock loading. The former solutions are determined by the alternating technique in three-dimensional fracture mechanics with a fourth order polynomial pressure distribution on the crack surface where both the front and back surface effects are accounted for. The latter solutions involve two-dimensional finite element solutions of single-edge notched plates with prescribed edge-displacements and single-edge notched cylinders with thermal shock loading. By comparing these two two-dimensional solutions, an estimate of the effect of the cylindrical curvature on an edge-cracked plate is obtained. The combination of these two sets of solutions thus yields an estimate of the stress intensity factor in an internal and external semi-elliptical crack in a thermally shocked cylinder

Response of Buried Vertically Oriented Cylinders to Dynamic Loading,

Science.gov (United States)

1980-06-01

BALSARA • , . / ,, _,-, -. 1i S ,LESPONSE OF BURIED VERTICALLY 9RIENTED CYLINDERS 𔃺 .-TO DINAMIC LOADING_ 9AYLE E. LRTOrwW&-N JIIMY P./BALSARA Nk...1.7, 2,8, and 4.0 inches). The end caps for the cylinders consisted of a steel shell filled with high- strength concrete; however, the end caps were...not designed to be test articles. The average concrete compressive strength of the cylinders on test day was 44.0 MPa (6,380 psi). The three DEOT

Advanced engine management of individual cylinders for control of exhaust species

Science.gov (United States)

Graves, Ronald L [Knoxville, TN; West, Brian H [Knoxville, TN; Huff, Shean P [Knoxville, TN; Parks, II, James E

2008-12-30

A method and system controls engine-out exhaust species of a combustion engine having a plurality of cylinders. The method typically includes various combinations of steps such as controlling combustion parameters in individual cylinders, grouping the individual cylinders into a lean set and a rich set of one or more cylinders, combusting the lean set in a lean combustion parameter condition having a lean air:fuel equivalence ratio, combusting the rich set in a rich combustion parameter condition having a rich air:fuel equivalence ratio, and adjusting the lean set and the rich set of one or more cylinders to generate net-lean combustion. The exhaust species may have elevated concentrations of hydrogen and oxygen.

Biphasic regulation of development of the high-affinity saxitoxin receptor by innervation in rat skeletal muscle

International Nuclear Information System (INIS)

Sherman, S.J.; Catterall, W.A.

1982-01-01

Specific binding of 3 H-saxitoxin (STX) was used to quantitate the density of voltage-sensitive sodium channels in developing rat skeletal muscle. In adult triceps surae, a single class of sites with a KD . 2.9 nM and a density of 21 fmol/mg wet wt was detected. The density of these high-affinity sites increased from 2.0 fmol/mg wet wt to the adult value in linear fashion during days 2-25 after birth. Denervation of the triceps surae at day 11 or 17 reduced final saxitoxin receptor site density to 10.4 or 9.2 fmol/mg wet wt, respectively, without changing KD. Denervation of the triceps surae at day 5 did not alter the subsequent development of saxitoxin receptor sites during days 5-9 and accelerated the increase of saxitoxin receptor sites during days 9-13. After day 13, saxitoxin receptor development abruptly ceased and the density of saxitoxin receptor sites declined to 11 fmol/wg wet wt. These results show that the regulation of high-affinity saxitoxin receptor site density by innervation is biphasic. During the first phase, which is independent of continuing innervation, the saxitoxin receptor density increases to 47-57% of the adult level. After day 11, the second phase of development, which is dependent on continuing innervation, gives rise to the adult density of saxitoxin receptors

Transient thermal stress problem for a circumferentially cracked hollow cylinder

Science.gov (United States)

Nied, H. F.; Erdogan, F.

1982-01-01

The transient thermal stress problem for a hollow elasticity cylinder containing an internal circumferential edge crack is considered. It is assumed that the problem is axisymmetric with regard to the crack geometry and the loading, and that the inertia effects are negligible. The problem is solved for a cylinder which is suddenly cooled from inside. First the transient temperature and stress distributions in an uncracked cylinder are calculated. By using the equal and opposite of this thermal stress as the crack surface traction in the isothermal cylinder the crack problem is then solved and the stress intensity factor is calculated. The numerical results are obtained as a function of the Fourier number tD/b(2) representing the time for various inner-to-outer radius ratios and relative crack depths, where D and b are respectively the coefficient of diffusivity and the outer radius of the cylinder.

Electromagnetic Invisibility of Elliptic Cylinder Cloaks

International Nuclear Information System (INIS)

Kan, Yao; Chao, Li; Fang, Li

2008-01-01

Structures with unique electromagnetic properties are designed based on the approach of spatial coordinate transformations of Maxwell's equations. This approach is applied to scheme out invisible elliptic cylinder cloaks, which provide more feasibility for cloaking arbitrarily shaped objects. The transformation expressions for the anisotropic material parameters and the field distribution are derived. The cloaking performances of ideal and lossy elliptic cylinder cloaks are investigated by finite element simulations. It is found that the cloaking performance will degrade in the forward direction with increasing loss. (fundamental areas of phenomenology (including applications))

Cylinder wakes in flowing soap films

International Nuclear Information System (INIS)

Vorobieff, P.; Ecke, R.E.; Vorobieff, P.

1999-01-01

We present an experimental characterization of cylinder wakes in flowing soap films. From instantaneous velocity and thickness fields, we find the vortex-shedding frequency, mean-flow velocity, and mean-film thickness. Using the empirical relationship between the Reynolds and Strouhal numbers obtained for cylinder wakes in three dimensions, we estimate the effective soap-film viscosity and its dependence on film thickness. We also compare the decay of vorticity with that in a simple Rankine vortex model with a dissipative term to account for air drag. copyright 1999 The American Physical Society

Numerical simulation coupling with experimental study on the non-uniform of each cylinder gas exchange and working processes of a multi-cylinder gasoline engine under transient conditions

International Nuclear Information System (INIS)

Zhou, Feng; Fu, Jianqin; Shu, Jun; Liu, Jingping; Wang, Shuqian; Feng, Renhua

2016-01-01

Highlights: • An approach is presented to detect the CTCV of engine under transient conditions. • The range and influence factors of CTCV of engine performances were revealed. • The maximum relative deviation of IMEP in each cylinder is larger than ±30%. • There appears a symmetry relation between CTCV of RGF and excess air coefficient. - Abstract: Cylinder-to-cylinder variation is unavoidable in multi-cylinder engine and has a severe impact on engine performance. To explore the cylinder-to-cylinder variation of engine under transient conditions, a hybrid method of dynamic signal measurement coupling with gas dynamics and thermodynamics processes simulation is presented to detect the parameters of engine. Then, this method is applied to an automobile engine under road test conditions, and the continuous state and performance parameters of each cylinder were obtained from cycle to cycle. On this basis, the range and influence factors of non-uniform of engine performance parameters were analyzed. The results show that, under transient conditions, the relative deviation of excess air coefficient in each cylinder is within ±5%, which is mainly affected by intake average pressure in low to medium speed operating regions but influenced by exhaust pressure wave and residual gas fraction in high-speed and high-load operating regions. There appears a symmetry relation between the non-uniform of RGF and excess air coefficient. The relative deviation of indicated mean effective pressure in each cylinder depends largely on the gas exchange performance, including excess air coefficient and residual gas fraction, and the maximum is larger than ±30%.

Bergmann glia and the recognition molecule CHL1 organize GABAergic axons and direct innervation of Purkinje cell dendrites.

Directory of Open Access Journals (Sweden)

Fabrice Ango

2008-04-01

Full Text Available The geometric and subcellular organization of axon arbors distributes and regulates electrical signaling in neurons and networks, but the underlying mechanisms have remained elusive. In rodent cerebellar cortex, stellate interneurons elaborate characteristic axon arbors that selectively innervate Purkinje cell dendrites and likely regulate dendritic integration. We used GFP BAC transgenic reporter mice to examine the cellular processes and molecular mechanisms underlying the development of stellate cell axons and their innervation pattern. We show that stellate axons are organized and guided towards Purkinje cell dendrites by an intermediate scaffold of Bergmann glial (BG fibers. The L1 family immunoglobulin protein Close Homologue of L1 (CHL1 is localized to apical BG fibers and stellate cells during the development of stellate axon arbors. In the absence of CHL1, stellate axons deviate from BG fibers and show aberrant branching and orientation. Furthermore, synapse formation between aberrant stellate axons and Purkinje dendrites is reduced and cannot be maintained, leading to progressive atrophy of axon terminals. These results establish BG fibers as a guiding scaffold and CHL1 a molecular signal in the organization of stellate axon arbors and in directing their dendritic innervation.

Three-dimensional vortex flow near the endwall of a short cylinder in crossflow: Stepped-diameter circular cylinder

International Nuclear Information System (INIS)

Chen, S.B.; Sanitjai, S.; Ghosh, K.; Goldstein, R.J.

2012-01-01

The effect of geometry on the flow around a cylinder in crossflow is investigated in this study. Three different stepped-diameter circular cylinders (SDCC s) with varying step heights are used. Extensive flow visualization using the oil-lampblack and smoke-wire techniques and near wake velocity measurements using a hotwire anemometer reveal complex secondary flows on and around the SDCC. Six vortices are observed in the horseshoe vortex system near the cylinder–endwall junction and six additional vortices are found in the step-induced vortex system on the step surface. Based on these experimental results, new secondary flow models are proposed. The step-induced vortices separate from the step surface at both sides and move toward the endwall, washing down the sides of the top/bottom larger diameter cylinders and interact with the separated shear layer and horseshoe vortices. In this process, they modify the near wake flow significantly: they produce an increase in velocity near the endwall region (below the step) and a decrease in velocity near the mid-span region, even altering the oscillatory behavior of the wake. - Highlights: ► Extensive flow visualization for stepped-diameter circular cylinders in crossflow. ► Six vortices in the horseshoe vortex system near the base. ► Six additional step-induced vortices on the upstream symmetry plane of step surface. ► Power spectral analysis for u′ shows oscillatory nature of the wake.

Stresses from pressure, radial, and moment loads in cylinder-to-cylinder vessel by a finite plate method

International Nuclear Information System (INIS)

Brown, S.J.; Fox, M.E.

1977-08-01

A structural problem that has received continued interest and development over the last several decades is the determination of stresses in two normally intersecting cylindrical shells subjected to internal pressure and external loading. In nuclear pressure vessels the external loading of the vessel through the attachment is encountered in thermal interaction, seismic loading and various postulated rupture or failure mechanisms. A simple technique, the Finite Plate Method, (FPM) is presented to analyze stresses in cylinder-to-cylinder junctures. The approach uses shallow shell formulations and a three term series expansion plate formulation, which limits the range of applicability. It is felt that the value of the method is its accuracy, economy, and ease in modeling a structure which falls within the range of applicability. Another appealing feature of the method is that its simplistic approach of superposition of results permits an easy extension to include additional loads not treated. For those mechanical loadings not developed, it is felt that their effect can either be accounted for by the mechanisms discussed or by simple calculations. Generally, the stresses resulting from torsional or transverse shear are small compared to the loads discussed, however, these shear effects may be included. Finally, in the instance of thermal stress within the cylinder-to-cylinder structure, it has been shown in an unpublished study by Brown that the FPM yields very good results for the range of curvatures discussed

Torsional vibrations of infinite composite poroelastic cylinders | Shah ...

African Journals Online (AJOL)

... radius of composite poroelastic solid cylinder to the radius of the inner solid cylinder. Results of previous works are shown as special case of the present analysis. By ignoring liquid effects, the results of purely elastic solid are obtained. International Journal of Engineering, Science and Technology, Vol. 2, No. 6, 2010, pp.

Changes in the substance P-containing innervation of the lumbosacral spinal cord in male Wistar rats as a consequence of ageing.

Science.gov (United States)

Ranson, Richard N; Priestley, David J; Santer, Robert M; Watson, Alan H D

2005-03-02

Quantitative image analysis was used to determine age-related changes in the substance P-containing innervation of autonomic and somatic nuclei in the lumbosacral spinal cord, which are associated with the control of micturition and sexual reflexes. In the upper lumbar segments (L1-L2), significant declines in the distribution density of substance P-containing processes were observed in the dorsal grey commissure, the intermediolateral cell column and the ventral horn. More caudally, at levels corresponding to L5 through S1, significant reductions were seen in the dorsal grey commissure and within the sacral parasympathetic nucleus. In contrast to these observations, the substance P-immunoreactive innervation of the dorsolateral nucleus remained robust in aged animals and was not significantly different from young adults. It is possible that these distinct age-related patterns of change in substance P-containing innervation, are reflected in the urinary/sexual dysfunction's in aged animals.

An online ID identification system for liquefied-gas cylinder plant

Science.gov (United States)

He, Jin; Ding, Zhenwen; Han, Lei; Zhang, Hao

2017-11-01

An automatic ID identification system for gas cylinders' online production was developed based on the production conditions and requirements of the Technical Committee for Standardization of Gas Cylinders. A cylinder ID image acquisition system was designed to improve the image contrast of ID regions on gas cylinders against the background. Then the ID digits region was located by the CNN template matching algorithm. Following that, an adaptive threshold method based on the analysis of local average grey value and standard deviation was proposed to overcome defects of non-uniform background in the segmentation results. To improve the single digit identification accuracy, two BP neural networks were trained respectively for the identification of all digits and the easily confusable digits. If the single digit was classified as one of confusable digits by the former BP neural network, it was further tested by the later one, and the later result was taken as the final identification result of this single digit. At last, the majority voting was adopted to decide the final identification result for the 6-digit cylinder ID. The developed system was installed on a production line of a liquefied-petroleum-gas cylinder plant and worked in parallel with the existing weighing step on the line. Through the field test, the correct identification rate for single ID digit was 94.73%, and none of the tested 2000 cylinder ID was misclassified through the majority voting.

Frictional properties of lubrication greases with the addition of nickel nanoparticles in pneumatic cylinder

Science.gov (United States)

Chang, Ho; Lan, Chou-Wei; Guo, Jia-Bin

2011-12-01

This paper studies the influence of addition of 100 nm diameter nickel nano-particles on the friction properties of synthetic grease (Li base, VG100) in pneumatic cylinder. The friction force test of pneumatic cylinder equipment measures the frictional force between seal and cylinder bore in pneumatic cylinders. The lubricants with addition of nickel nano-particles were used for lubricating the contact interface between seal and cylinder bore. The friction force test equipment employ a load cell force sensor to measure the friction force between seals and cylinder bores. Results obtained from experimental tests are compared to determine the friction force between seals and cylinder bore in pneumatic cylinders. The study leads to the conclusion that the addition of nickel nano-particles to synthetic grease results in a decrease in friction force between seals and cylinder bores in pneumatic cylinder. This tribological behavior is closely related to the deposition of nano-particles on the rubbing surfaces

A pneumatic cylinder driving polyhedron mobile mechanism

Science.gov (United States)

Ding, Wan; Kim, Sung-Chan; Yao, Yan-An

2012-03-01

A novel pneumatic cylinder driving polyhedron mobile mechanism is proposed in this paper. The mechanism is comprised of 5 tetrahedrons which includes a pneumatic cylinder in each edge. It locomotes by rolling and the rolling principle refers to the center of mass (CM) of the mechanism moved out of the supporting area and let it tip over through the controlling of the motion sequence of these cylinders. Firstly, the mathematical model is built to analysis the relation between the configuration and the CM of the mechanism. Then, a binary control strategy is developed to simplify and improve the control of this mobile mechanism. After that, dynamic simulation is performed to testify the analytical validity and feasibility of the rolling gaits. At last, a prototype is fabricated to achieve the rolling successfully to demonstrate the proposed concept.

The provision of clearances accuracy in piston - cylinder mating

Science.gov (United States)

Glukhov, V. I.; Shalay, V. V.

2017-08-01

The paper is aimed at increasing the quality of the pumping equipment in oil and gas industry. The main purpose of the study is to stabilize maximum values of productivity and durability of the pumping equipment based on the selective assembly of the cylinder-piston kinematic mating by optimization criterion. It is shown that the minimum clearance in the piston-cylinder mating is formed by maximum material dimensions. It is proved that maximum material dimensions are characterized by their own laws of distribution within the tolerance limits for the diameters of the cylinder internal mirror and the outer cylindrical surface of the piston. At that, their dispersion zones should be divided into size groups with a group tolerance equal to half the tolerance for the minimum clearance. The techniques for measuring the material dimensions - the smallest cylinder diameter and the largest piston diameter according to the envelope condition - are developed for sorting them into size groups. Reliable control of the dimensions precision ensures optimal minimum clearances of the piston-cylinder mating in all the size groups of the pumping equipment, necessary for increasing the equipment productivity and durability during the production, operation and repair processes.

Bursting pressure of autofrettaged cylinders with inclined external cracks

Energy Technology Data Exchange (ETDEWEB)

Seifi, Rahman, E-mail: rseifi@basu.ac.ir [Mechanical Engineering Department, Faculty of Engineering, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of); Babalhavaeji, Majid [Mechanical Engineering Department, Faculty of Engineering, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of)

2012-01-15

Autofrettaging a pressure vessel improves its pressure capacity. This is reliable if there isn't any crack or other type of flaws. In this paper, the effects of external surface cracks on bursting pressure of autofrettaged cylinders are studied. It is observed that bursting pressure decreases considerably (up to 30%) due to external cracks in the cylinders without autofrettage. This reduction increases for high levels of the applied autofrettage. External axial cracks have more effects than inclined cracks. Comparing experimental and numerical results show that the numerical methods can acceptably predict the bursting pressure of the autofrettaged cracked cylinders. These predictions are valid when the fracture parameter (J-Integral) is calculated from the modified equation that takes into account the effects of residual stresses. - Highlights: Black-Right-Pointing-Pointer Modified J-Integral can be used for study of autofrettaged cracked cylinders. Black-Right-Pointing-Pointer External axial cracks reduce considerably the pressure capacity of cylinders. Black-Right-Pointing-Pointer External circumferential cracks have not considerable effects on bursting pressure. Black-Right-Pointing-Pointer Autofrettage has contrary effects on external crack in compared with internal crack.

Adrenal hormones interact with sympathetic innervation to modulate growth of embryonic heart in oculo.

Science.gov (United States)

Tucker, D C; Torres, A

1992-02-01

To allow experimental manipulation of adrenal hormone and autonomic influences on developing myocardium without alteration of hemodynamic load, embryonic rat heart was cultured in the anterior eye chamber of an adult rat. Sympathetic innervation of embryonic day 12 heart grafts was manipulated by surgical sympathectomy of one eye chamber in each host rat. Adrenal hormone exposure was manipulated by host adrenal medullectomy (MEDX) in experiment 1 and by host adrenalectomy (ADX) in experiment 2. In experiment 1, whole heart grafts were larger in MEDX than in sham-operated hosts by 8 wk in oculo (6.14 +/- 0.71 vs. 5.09 +/- 0.69 mm2 with innervation intact and 7.97 +/- 2.07 vs. 3.09 +/- 0.63 mm2 with sympathetic innervation prevented). In experiment 2, host ADX increased growth of embryonic day 12 ventricles grafted into sympathectomized eye chambers (0.69 +/- 0.10 vs. 0.44 +/- 0.04 mm2) but did not affect growth of grafts in intact eye chambers (0.85 +/- 0.09 vs. 1.05 +/- 0.15 mm2). Corticosterone replacement (4 mg/day) entirely reversed the effect of host ADX on graft growth (superior cervical ganglionectomy, 0.47 +/- 0.03 mm2; intact eye chambers, 0.90 +/- 0.91 mm2). Beating rate of grafts was not affected by adrenal hormone manipulations. These experiments indicate that the compromised growth of embryonic heart grafts placed in sympathectomized eye chambers requires exposure to adult levels of glucocorticoids during the early days after grafting. These results suggest that interactions between neural and hormonal stimulation influence cardiac growth in the in oculo culture system and during normal development.

Sensory innervation of the temporomandibular joint in the mouse.

Science.gov (United States)

Dreessen, D; Halata, Z; Strasmann, T

1990-01-01

The sensory innervation of the temporomandibular joints (TMJs) of 8 STR/IN mice was investigated by means of light and electron microscopy. Through the cutting of complete semithin sections in series it was possible to investigate the joints thoroughly. Additionally, one joint with its nerve supply was reconstructed three-dimensionally with a computerized three-dimensional programme. The reconstruction was based on one complete semithin section series. The joint's nerve supply originates from the nervus auriculotemporalis and additionally from motor branches of the n. mandibularis: n. massetericus, n. pterygoideus lateralis and the nn. temporales posteriores. The greatest number of nerve fibres and endings is located in the dorsolateral part of the joint capsule. They lie only in the stratum fibrosum and subsynovially. Neither the stratum synoviale nor the discus articularis contain any nerve fibres or endings, whereas the peri-articular loose connective tissue is richly innervated. The only type of nerve ending observed within the joint was the free nerve ending, which is assumed to serve not only as a nociceptor but also as a polymodal mechanoreceptor. Merely within the insertion of the musculus pterygoideus lateralis at the collum mandibulae single stretch receptors of the Ruffini type were observed. Ultrastructurally, they correspond to those described in the cat's knee joint. Neither lamellated nor nerve endings of the Golgi or Pacini type were observed in the joint or in the peri-articular connective tissue. The unexpected paucity of nerve fibres and endings in the TMJ itself of the mouse suggests that the afferent information from the joint is less important for position sense and movement than the afferent information from muscles, tendons and periodontal ligaments.

Formation of whispering gallery modes by scattering of an electromagnetic plane wave by two cylinders

Energy Technology Data Exchange (ETDEWEB)

Abramov, Arnold, E-mail: qulaser@gmail.com [Kuang-Chi Institute of Advanced Technology, Shenzhen, 518057 (China); Kostikov, Alexander [Donbass State Engineering Academy, 84303, Kramatorsk, Donetsk (Ukraine)

2017-03-26

We report the effect of scattering of electromagnetic plane waves by two cylinders on whispering gallery mode (WGM) formation in a cylinder. WGM can occur because of the presence of additional cylinder scatterers at specific location, while WGMs can only form in a single cylinder for specific cylinder radius and/or wavelength values, the matching accuracy required would be much greater than that required in our model for the additional cylinders locations. Analysis of the general solution to the problem showed that the effect can be explained by the interference of waves scattered by additional cylinders and incident on the main cylinder. - Highlights: • We consider scattering of electromagnetic plane waves by two cylinders. • WGMs occur because of the presence of additional cylinder at specific location. • The accuracy for the locations is much less than required for specific values of single cylinder. • The interference of waves scattered by additional cylinders and incident on the main is responsible for the effect.

Flow around a confined cylinder: LES and PIV study

Directory of Open Access Journals (Sweden)

Palkin Egor

2017-01-01

Full Text Available We study the flow over a cylinder placed between two parallel rigid walls using Large-eddy simulations and Particle Image Velocimetry. The Reynolds number based on the inflow velocity and diameter of the cylinder is 3750 corresponding to the subcritical regime with laminar separation. Three-dimensional visualization shows the presence of the horseshoe vortex system prior to the cylinder. The comparison of time-averaged velocity fields and fluctuations shows good agreement between simulations and experiments. Spectral analysis suggests the presence of low-frequency modulations of the recirculating bubble.

Collision Probabilities for Finite Cylinders and Cuboids

Energy Technology Data Exchange (ETDEWEB)

Carlvik, I

1967-05-15

Analytical formulae have been derived for the collision probabilities of homogeneous finite cylinders and cuboids. The formula for the finite cylinder contains double integrals, and the formula for the cuboid only single integrals. Collision probabilities have been calculated by means of the formulae and compared with values obtained by other authors. It was found that the calculations using the analytical formulae are much quicker and give higher accuracy than Monte Carlo calculations.

Management of pain in autosomal dominant polycystic kidney disease and anatomy of renal innervation.

Science.gov (United States)

Tellman, Matthew W; Bahler, Clinton D; Shumate, Ashley M; Bacallao, Robert L; Sundaram, Chandru P

2015-05-01

Chronic pain is a prominent feature of autosomal dominant polycystic kidney disease that is difficult to treat and manage, often resulting in a decrease in quality of life. Understanding the underlying anatomy of renal innervation and the various etiologies of pain that occur in autosomal dominant polycystic kidney disease can help guide proper treatments to manage pain. Reviewing previously studied treatments for pain in autosomal dominant polycystic kidney disease can help characterize treatment in a stepwise fashion. We performed a literature search of the etiology and management of pain in autosomal dominant polycystic kidney disease and the anatomy of renal innervation using PubMed® and Embase® from January 1985 to April 2014 with limitations to human studies and English language. Pain occurs in the majority of patients with autosomal dominant polycystic kidney disease due to renal, hepatic and mechanical origins. Patients may experience different types of pain which can make it difficult to clinically confirm its etiology. An anatomical and histological evaluation of the complex renal innervation helps in understanding the mechanisms that can lead to renal pain. Understanding the complex nature of renal innervation is essential for surgeons to perform renal denervation. The management of pain in autosomal dominant polycystic kidney disease should be approached in a stepwise fashion. Acute causes of renal pain must first be ruled out due to the high incidence in autosomal dominant polycystic kidney disease. For chronic pain, nonopioid analgesics and conservative interventions can be used first, before opioid analgesics are considered. If pain continues there are surgical interventions such as renal cyst decortication, renal denervation and nephrectomy that can target pain produced by renal or hepatic cysts. Chronic pain in patients with autosomal dominant polycystic kidney disease is often refractory to conservative, medical and other noninvasive treatments

A numerical investigation of sub-wavelength resonances in polygonal metamaterial cylinders

DEFF Research Database (Denmark)

Arslanagic, Samel; Breinbjerg, Olav

2009-01-01

The sub-wavelength resonances, known to exist in metamaterial radiators and scatterers of circular cylindrical shape, are investigated with the aim of determining if these resonances also exist for polygonal cylinders and, if so, how they are affected by the shape of the polygon. To this end, a set...... of polygonal cylinders excited by a nearby electric line current is analyzed numerically and it is shown, through detailed analysis of the near-field distribution and radiation resistance, that these polygonal cylinders do indeed support sub-wavelength resonances similar to those of the circular cylinders...

Transient thermal stresses in circular cylinder under intermittently sudden heat generation

International Nuclear Information System (INIS)

Sugano, Y.; Saito, K.; Takeuti, Y.

1975-01-01

The thermal stresses associated with the transient temperature distribution arising in a circular cylinder under intermittently changing sudden heat generation over a finite band and with heat loss to a surrounding medium on the remainder of the cylinder surface are exactly analysed. For the first time the temperature field in a circular cylinder under sudden heat generation over a finite band of the cylinder surface is determined by combined use of Fourier cosine, Laplace transforms in axial position and time, respectively. Secondly it is assumed that the temperature fields in a circular cylinder subjected to heat generation Qsub(i) (i=0, 1, 2, ...) independently over a finite band are given by T 0 (r,z,t), T 1 (r,z,t), T 2 (r,z,t),... respectively. Tsub(i)(r,z,t) indicates the temperature field before the i-th heat generation Qsub(i). The thermal stresses associated with the temperature field described above are analysed by using the Hoyle stress functions. Numerical calculations are carried out for the extensive case of the ratio of the heat-generating length to the diameter of cylinder. It is found that the time in which the maximum stresses occur on the cylinder surface does not depend on the heat-generating length-to-diameter ratio

Stokes flow past a swarm of porous circular cylinders with Happel ...

Indian Academy of Sciences (India)

The problem of creeping flow past a swarm of porous circular cylinders with Happel and Kuwabara boundary conditions is investigated. The Brinkman equation for the flow inside the porous cylinder and the Stokes equation outside the porous cylinder in their stream function formulations are used. The force experienced by ...

Effects of fire exposure on integrity of UF6 shipping cylinders

International Nuclear Information System (INIS)

Barlow, C.R.; Ziehlke, K.T.; Pryor, W.A.

1985-01-01

Two 2-1/2-ton steel cylinders for the transport of uranium hexafluoride within the United States nuclear fuel enrichment cycle were involved in a warehouse fire where portions of the cylinders were estimated to have reached a temperature of 1600 0 F (870 0 C). The cylinders were empty at the time of the fire and therefore were not in protective overpacks in which full product cylinders are handled while in transit. Hydrostatic tests to failure showed that the integrity of the cylinders was not degraded by exposure to the temperatures generated by the fire. They withstood test pressures in excess of 10 times the design pressure, and showed a volume expansion of 30% above the original capacity before rupture in a completely ductile fashion. Reference CAPE-323. 9 figs

Four-Cylinder Stirling-Engine Computer Program

Science.gov (United States)

Daniele, C. J.; Lorenzo, C. F.

1986-01-01

Computer program developed for simulating steady-state and transient performance of four-cylinder Stirling engine. In model, four cylinders interconnected by four working spaces. Each working space contains seven volumes: one for expansion space, heater, cooler, and compression space and three for regenerator. Thermal time constant for regenerator mass associated with each regenator gas volume. Former code generates results very quickly, since it has only 14 state variables with no energy equation. Current code then used to study various aspects of Stirling engine in much more detail. Program written in FORTRAN IV for use on IBM 370 computer.

Lattice Boltzmann simulation of viscoelastic flow past a confined free rotating cylinder

Science.gov (United States)

Xia, Yi; Zhang, Peijie; Lin, Jianzhong; Ku, Xiaoke; Nie, Deming

2018-05-01

To study the dynamics of rigid body immersed in viscoelastic fluid, an Oldroyd-B fluid flow past an eccentrically situated, free rotating cylinder in a two-dimensional (2D) channel is simulated by a novel lattice Boltzmann method. Two distribution functions are employed, one of which is aimed to solve Navier-Stokes equation and the other to the constitutive equation, respectively. The unified interpolation bounce-back scheme is adopted to treat the moving curved boundary of cylinder, and the novel Galilean invariant momentum exchange method is utilized to obtain the hydrodynamic force and torque exerted on the cylinder. Results show that the center-fixed cylinder rotates inversely in the direction where a cylinder immersed in Newtonian fluid do, which generates a centerline-oriented lift force according to Magnus effect. The cylinder’s eccentricity, flow inertia, fluid elasticity and viscosity would affect the rotation of cylinder in different ways. The cylinder rotates more rapidly when located farther away from the centerline, and slows down when it is too close to the wall. The rotation frequency decreases with increasing Reynolds number, and larger rotation frequency responds to larger Weissenberg number and smaller viscosity ratio, indicating that the fluid elasticity and low solvent viscosity accelerates the flow-induced rotation of cylinder.

Flow and flow-induced vibration of a square array of cylinders in steady currents

Energy Technology Data Exchange (ETDEWEB)

Zhao, Ming [School of Computing, Engineering and Mathematics, University of Western Sydney, Locked Bag 1797, Penrith, NSW 2751 (Australia); Cheng, Liang; An, Hongwei; Tong, Feifei, E-mail: m.zhao@uws.edu.au [School of Civil, Environmental and Mining Engineering, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia)

2015-08-15

Flow and flow-induced vibration of a square array of cylinders are investigated by two-dimensional numerical simulations. Flow past 36 cylinders in an inline arranged square array and 33 cylinders in a staggered arranged square array is firstly simulated, for Re = 100 and the spacing ratios of L/D = 1.5, 2, 3, 4, 5. Only one vortex street is observed in the wake of the cylinder array when the spacing ratio is 1.5 in the inline arrangement and 1.5 and 2 in the staggered arrangement, indicating that the critical spacing ratio for the single-vortex street mode in the staggered arrangement is higher than that in the inline arrangement. The vortex shedding from the cylinders is suppressed at L/D = 3 for both inline and staggered arrangements. Vortex shedding from each individual cylinder is observed when L/D = 4. Flow-induced vibration of 36 cylinders in an inline square arrangement is studied for a constant Reynolds number of 100, two spacing ratios of 2 and 5, a constant mass ratio of 2.5 and a wide range of reduced velocities. It is found that for a spacing ratio of 2, the vibration of the cylinders in the four downstream columns does not start until the reduced velocity exceeds 4.5. The vibration of the cylinders progresses downstream with increasing reduced velocity. For a spacing ratio of 5, the vibrations of the cylinders in the most upstream column are similar to that of a single cylinder. The vibration amplitudes of the downstream cylinders peak at higher reduced velocities than that of a single cylinder. The maximum possible response amplitudes occur at the most downstream cylinders. (paper)

Dynamic Fracture Simulations of Explosively Loaded Cylinders

Energy Technology Data Exchange (ETDEWEB)

Arthur, Carly W. [Univ. of California, Davis, CA (United States). Dept. of Civil and Environmental Engineering; Goto, D. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2015-11-30

This report documents the modeling results of high explosive experiments investigating dynamic fracture of steel (AerMet® 100 alloy) cylinders. The experiments were conducted at Lawrence Livermore National Laboratory (LLNL) during 2007 to 2008 [10]. A principal objective of this study was to gain an understanding of dynamic material failure through the analysis of hydrodynamic computer code simulations. Two-dimensional and three-dimensional computational cylinder models were analyzed using the ALE3D multi-physics computer code.

Relaxation of Thick-Walled Cylinders and Spheres

DEFF Research Database (Denmark)

Saabye Ottosen, N.

1982-01-01

Using the nonlinear creep law proposed by Soderberg, (1936) closed-form solutions are derived for the relaxation of incompressible thick-walled spheres and cylinders in plane strain. These solutions involve series expressions which, however, converge very quickly. By simply ignoring these series...... expressions, extremely simple approximate solutions are obtained. Despite their simplicity these approximations possess an accuracy that is superior to approximations currently in use. Finally, several physical aspects related to the relaxation of cylinders and spheres are discussed...

Bristol cylinder. Vol. 3A - technical appraisal

Energy Technology Data Exchange (ETDEWEB)

1983-06-01

A consultants' report is presented on a UK funded wave energy device known as the Bristol Cylinder. A detailed engineering appraisal is given for each component and aspects of the device including installation, power generation and maintenance. Finally the discounted cost of energy from the device is assessed. For all topics the views of the consultants are compared with those of the team developing the Bristol Cylinder and where discrepancies occur, these are explained and discussed.

Corrosion of breached UF6 storage cylinders

International Nuclear Information System (INIS)

Barber, E.J.; Taylor, M.S.; DeVan, J.H.

1993-01-01

This paper describes the corrosion processes that occurred following the mechanical failure of two steel 14-ton storage cylinders containing depleted UF 6 . The failures both were traced to small mechanical tears that occurred during stacking of the cylinders. Although subsequent corrosion processes greatly extended the openings in the wall. the reaction products formed were quite protective and prevented any significant environmental insult or loss of uranium. The relative sizes of the two holes correlated with the relative exposure times that had elapsed from the time of stacking. From the sizes and geometries of the two holes, together with analyses of the reaction products, it was possible to determine the chemical reactions that controlled the corrosion process and to develop a scenario for predicting the rate of hydrolysis of UF 6 , the loss rate of HF, and chemical attack of a breached UF 6 storage cylinder

Flow Features of Three Side-by-side Circular Cylinders at Low Reynolds Number

Directory of Open Access Journals (Sweden)

Liu Junkao

2016-01-01

Full Text Available In order to study the fluctuation of kinetic parameter of cylinder matrix in incompressible stationary flow, the flow fluid around three side-by-side circular cylinders are simulated using Immersed Boundary–Lattice Boltzmann method (IB-LBM. Drag and lift force of the three cylinders are investigated as the interval between each cylinder varied from zero to five times of the cylinder diameter. Five flow patterns are defined according to the vortices structure in the downstream of the cylinders. Power spectrum analysis of lift force is developed to explain the vortex patterns. Through the research, we find the strength and phase of the gap flow play an important role in the vortex formatting process. The vortices shedding from different cylinders neutralize and combine in the near wake, contributing a lot to the variation of forces.

Bilateral familial vertical Duane Syndrome with synergistic convergence, aberrant trigeminal innervation, and facial hypoplasia

Directory of Open Access Journals (Sweden)

Malvika Gupta

2014-01-01

Full Text Available A 5-year-old girl presented with bilateral familial vertical  Duane retraction syndrome with alternating esotropia, elevation deficit, Marcus gunn phenomenon, and facial hypoplasia. Abnormal adducting downshoots on attempting abduction suggestive of a synergistic convergence were noted. Hypothesis suggests aberrant innervations or peripheral anatomic connections between inferior and medial recti.

Extended Analytic Linear Model of Hydraulic Cylinder With Respect Different Piston Areas and Volumes

Directory of Open Access Journals (Sweden)

Petr KOŇAŘÍK

2009-06-01

Full Text Available Standard analytic linear model of hydraulic cylinder usually comes from assumptions of identical action piston areas on both sides of hydraulic cylinder (double piston rod and suitable operation point, which is usually chosen in the middle of piston. By reason of that volumes inside of cylinder are than same. Moreover for control of that arrangement of hydraulic cylinder, usually controlled by 4/3 servovalve, the same mount of flows comes in and comes out to each of chambers of hydraulic cylinder. Presented paper deal with development of extended form of analytic linear model of single piston rod hydraulic cylinder which respects different action piston areas and volumes inside of chambers of hydraulic cylinder and also two different input flows of hydraulic cylinder. In extended model are also considered possibilities of different dead volumes in hoses and intake parts of hydraulic cylinder. Dead volume has impact on damping of hydraulic cylinder. Because the system of hydraulic cylinder is generally presented as a integrative system with inertia of second order: eq , we can than obtain time constants and damping of hydraulic cylinder for each of analytic form model. The model has arisen for needs of model fractionation on two parts. Part of behaviour of chamber A and part of behaviour of chamber B of cylinder. It was created for the reason of analysis and synthesis of control parameters of regulation circuit of multivalve control concept of hydraulic drive with separately controlled chamber A and B which could be then used for.

Optimization of In-Cylinder Pressure Filter for Engine Research

Science.gov (United States)

2017-06-01

ARL-TR-8034 ● JUN 2017 US Army Research Laboratory Optimization of In-Cylinder Pressure Filter for Engine Research by Kenneth...Laboratory Optimization of In-Cylinder Pressure Filter for Engine Research by Kenneth S Kim, Michael T Szedlmayer, Kurt M Kruger, and Chol-Bum M...

In-depth Study on Cylinder Wake Controlled by Lorentz Force

International Nuclear Information System (INIS)

Zhang Hui; Fan Bao-Chun; Chen Zhi-Hua

2011-01-01

The underlying mechanisms of the electromagnetic control of cylinder wake are investigated and discussed. The effects of Lorentz force are found to be composed of two parts, one is its direct action on the cylinder (the wall Lorentz force) and the other is applied to the fluid (called the field Lorentz force) near the cylinder surface. Our results show that the wall Lorentz force can generate thrust and reduce the drag; the field Lorentz force increases the drag. However, the cylinder drag is dominated by the wall Lorentz force. In addition, the field Lorentz force above the upper surface decreases the lift, while the upper wall Lorentz force increases it. The total lift is dominated by the upper wall Lorentz force. (fundamental areas of phenomenology(including applications))

Method and apparatus for filling cryogenic liquid cylinders

International Nuclear Information System (INIS)

Remes, S.

1984-01-01

A method and apparatus are disclosed for filling a portable cryogenic liquid cylinder from a large stand tank. The invention employs a regulator valve to perform an automatic throttling function whereby the pressure in the liquid cylinder is maintained at a value slightly lower than the upstream pressure in the stand tank. This significantly reduces filling losses due to flashing

Heart Development, Diseases, and Regeneration　- New Approaches From Innervation, Fibroblasts, and Reprogramming.

Science.gov (United States)

Ieda, Masaki

2016-09-23

It is well known that cardiac function is tightly controlled by neural activity; however, the molecular mechanism of cardiac innervation during development and the relationship with heart disease remain undetermined. My work has revealed the molecular networks that govern cardiac innervation and its critical roles in heart diseases such as silent myocardial ischemia and arrhythmias. Cardiomyocytes proliferate during embryonic development, but lose their proliferative capacity after birth. Cardiac fibroblasts are a major source of cells during fibrosis and induce cardiac hypertrophy after myocardial injury in the adult heart. Despite the importance of fibroblasts in the adult heart, the role of fibroblasts in embryonic heart development was previously not determined. I demonstrated that cardiac fibroblasts play important roles in myocardial growth and cardiomyocyte proliferation during embryonic development, and I identified key paracrine factors and signaling pathways. In contrast to embryonic cardiomyocytes, adult cardiomyocytes have little regenerative capacity, leading to heart failure and high mortality rates after myocardial infarction. Leveraging the knowledge of developmental biology, I identified cardiac reprogramming factors that can directly convert resident cardiac fibroblasts into cardiomyocytes for heart regeneration. These findings greatly improved our understanding of heart development and diseases, and provide a new strategy for heart regenerative therapy. (Circ J 2016; 80: 2081-2088).

System and method of cylinder deactivation for optimal engine torque-speed map operation

Science.gov (United States)

Sujan, Vivek A; Frazier, Timothy R; Follen, Kenneth; Moon, Suk-Min

2014-11-11

This disclosure provides a system and method for determining cylinder deactivation in a vehicle engine to optimize fuel consumption while providing the desired or demanded power. In one aspect, data indicative of terrain variation is utilized in determining a vehicle target operating state. An optimal active cylinder distribution and corresponding fueling is determined from a recommendation from a supervisory agent monitoring the operating state of the vehicle of a subset of the total number of cylinders, and a determination as to which number of cylinders provides the optimal fuel consumption. Once the optimal cylinder number is determined, a transmission gear shift recommendation is provided in view of the determined active cylinder distribution and target operating state.

Axo-somatic synapses in the normal and X-irradiated dendate gyrus; factors affecting the density of afferent innervation

International Nuclear Information System (INIS)

Lee, K.S.; Gerbrandt, L.; Lynch, G.

1982-01-01

The density of synaptic input to the somata of dentate gyrus granule cells was examined utilizing quantitative electron microscopic techniques. In control (non-irradiated) material, greater numbers of axo-somatic synapses were observed in the superficial, earlier-generated cells as compared to the deep, later-generated cells. We further studied the X-irradiated dentate gyrus, in which the majority of granule cells were destroyed during postnatal genesis. The surviving cells displayed a density of innervation on their somata which exceeded that observed in either layer of the control material. These data are discussed in terms of the possible contribution of afferent-target cell interactions to the regulation of the density of synaptic innervation. (Auth.)

Axo-somatic synapses in the normal and X-irradiated dendate gyrus; factors affecting the density of afferent innervation

Energy Technology Data Exchange (ETDEWEB)

Lee, K S [Max-Planck-Institut fuer Psychiatrie, Muenchen (Germany, F.R.); Gerbrandt, L [Neuroscience Research Program, Boston, MA (USA); Lynch, G [California Univ., Irvine (USA)

1982-10-07

The density of synaptic input to the somata of dentate gyrus granule cells was examined utilizing quantitative electron microscopic techniques. In control (non-irradiated) material, greater numbers of axo-somatic synapses were observed in the superficial, earlier-generated cells as compared to the deep, later-generated cells. We further studied the X-irradiated dentate gyrus, in which the majority of granule cells were destroyed during postnatal genesis. The surviving cells displayed a density of innervation on their somata which exceeded that observed in either layer of the control material. These data are discussed in terms of the possible contribution of afferent-target cell interactions to the regulation of the density of synaptic innervation.

Vortex shedding from tandem cylinders

Science.gov (United States)

Alam, Md. Mahbub; Elhimer, Mehdi; Wang, Longjun; Jacono, David Lo; Wong, C. W.

2018-03-01

An experimental investigation is conducted on the flow around tandem cylinders for ranges of diameter ratio d/ D = 0.25-1.0, spacing ratio L/ d = 5.5-20, and Reynolds number Re = 0.8 × 104-2.42 × 104, where d and D are the diameters of the upstream and downstream cylinders, respectively, L is the distance from the upstream cylinder center to the forward stagnation point of the downstream one. The focus is given on examining the effects of d/ D, L/ d and Re on Strouhal number St, flow structures and fluid forces measured using hotwire, particle image velocimetry (PIV) and load cell measurement techniques, respectively. Changes in d/ D and L/ d in the ranges examined lead to five flow regimes, namely lock-in, intermittent lock-in, no lock-in, subharmonic lock-in and shear-layer reattachment regimes. Time-mean drag coefficient ( C D) and fluctuating drag and lift coefficients ({C^'D} and {C^'L}) are more sensitive to L/ d than d/ D. The scenario is opposite for St where d/ D is more prominent than L/ d to change the St. The detailed facet of the dependence on d/ D and L/ d of C D, {C^'D}, {C^'L} and St is discussed based on shear-layer velocity, approaching velocity, vortex formation length, and wake width.

Faraday effect in hollow quantum cylinder of finite thickness

International Nuclear Information System (INIS)

Ismailov, T.G.; Jabrailova, G.G.

2009-01-01

The interband Faraday rotation in hollow quantum cylinder of finite thickness is theoretically investigated. Faraday rotation in the dependence on incident light energy for different values of cylinder thickness. It is seen that the resonance peaks appear on Faraday rotation curve. The roles of selection are obtained

Does crossover innervation really affect the clinical outcome? A comparison of outcome between unilateral and bilateral digital nerve repair

Directory of Open Access Journals (Sweden)

Melike Oruç

2016-01-01

Full Text Available Digital nerve injuries are the mostly detected nerve injury in the upper extremity. However, since the clinical phenomenon of crossover innervation at some degree from uninjured digital nerve to the injured side occurs after digital nerve injuries is sustained, one could argue that this concept might even result in the overestimation of the outcome of the digital nerve repair. With this knowledge in mind, this study aimed to present novel, pure, focused and valuable clinical data by comparing the outcomes of bilateral and unilateral digital nerve repair. A retrospective review of 28 fingers with unilateral or bilateral digital nerve repair using end-to-end technique in 19 patients within 2 years was performed. Weber′s two-point discrimination, sharp/dull discrimination, warm/cold sensation and Visual Analog Scale scoring were measured at final 12-month follow ups in all patients. There was no significant difference in recovery of sensibility after unilateral and bilateral digital nerve repairs. Though there is crossover innervation microscopically, it is not important in the clinical evaluation period. According to clinical findings from this study, crossover innervations appear to be negligible in the estimation of outcomes of digital neurorrhaphy.

Infinitely long cylinder in a sinusoidal field (Problem 2)

International Nuclear Information System (INIS)

Ida, N.

1986-01-01

The results presented here were obtained with a 2-D (and axisymmetric) eddy current program called EDDYNDT. The program uses the magnetic vector potential formulation and was specifically designed for the calculation of coil impedances in NDT applications. For normal applications, flux densities, forces, eddy current densities and stored and dissipated energies are not calculated. The program required minor modifications to calculated these quantities form the magnetic vector potential. In its present form, program EDDYNDT cannot handle flux normal boundary conditions. To avoid this, half the cylinder was modeled as opposed to the quarter cylinder in the mesh recommended in the problem outline. This increased the number of elements and nodes but did not change their density or location. Both a solution without the cylinder and a solution with the cylinder are presented. The fields presented are calculated at the center of each element. For this reason, the values presented are interpolated between neighboring elements. This creates a problem, particularly at discontinuities where the errors are largest

Rolling Cylinder Phase 1

DEFF Research Database (Denmark)

Margheritini, Lucia; Taraborrelli, Valeria Taraborrelli

Margheritini and Valeria Taraborrelli(valeria.taraborrelli@hotmail.it) with a total of 3 day visit from the developers. Laboratory tests in irregular waves will be performed by Lucia Margheritini. The report is aimed at the first stage testing of the Rolling Cylinder wave energy device. This phase includes...

Electrostatics of spherical metallic particles in cylinder electrostatic separators/sizers

International Nuclear Information System (INIS)

Lu Hongzhou; Li Jia; Guo Jie; Xu Zhenming

2006-01-01

This paper presents a theoretical analysis of the dynamics of spherical metallic particles in electrostatic separators/sizers (ESSs). A computational algorithm is employed to depict the cylinder-type electrode arrangements applied in some electrostatic processes generating non-uniform electric fields. The ESS consists of a pair of conducting cylinders. The upper cylinder is energized by HVdc, while the lower one is grounded and mounted horizontally on a revolvable axis. The aim of this paper is to present a new electrode configuration and demonstrate the usefulness of numerical techniques for the evaluation of the particle's motion. A computer program was employed for analysing the behavior of spherical particles in a two-dimensional electrode arrangement that models the actual electric field configuration of cylinder-type electrostatic separators/sizers. The analysis is needed for the development of any new application of this cylinder-type electrode arrangement as an electrostatic separation method. The results reveal that the particle's motion depends on its radius and density and amplitude of the applied voltage. The actual granular mixtures with different specific mass and radius could be separated applying this cylinder-type electrostatic separation method; the lift voltage is an important parameter for separation. With a program for two-dimensional analysis of the electric field, the computational procedure presented in this paper could be employed for any particle shapes

Bubbly flows around a two-dimensional circular cylinder

Science.gov (United States)

Lee, Jubeom; Park, Hyungmin

2016-11-01

Two-phase cross flows around a bluff body occur in many thermal-fluid systems like steam generators, heat exchangers and nuclear reactors. However, our current knowledge on the interactions among bubbles, bubble-induced flows and the bluff body are limited. In the present study, the gas-liquid bubbly flows around a solid circular cylinder are experimentally investigated while varying the mean void fraction from 5 to 27%. The surrounding liquid (water) is initially static and the liquid flow is only induced by the air bubbles. For the measurements, we use the high-speed two-phase particle image velocimetry techniques. First, depending on the mean void fraction, two regimes are classified with different preferential concentration of bubbles in the cylinder wake, which are explained in terms of hydrodynamic force balances acting on rising bubbles. Second, the differences between the two-phase and single-phase flows (while matching their Reynolds numbers) around a circular cylinder will be discussed in relation to effects of bubble dynamics and the bubble-induced turbulence on the cylinder wake. Supported by a Grant (MPSS-CG-2016-02) through the Disaster and Safety Management Institute funded by Ministry of Public Safety and Security of Korean government.

Case Report: Facial and eye injury following a fridge cylinder gas explosion

Directory of Open Access Journals (Sweden)

Monsudi Kehinde Fasasi

2017-11-01

Full Text Available Fridge cylinders contain liquefied petroleum gas (LPG, an inflammable gas of mixture of propane and butane [1]. It’s colourless but odourised to give warning during leakage. Injury from accidental fridge cylinder explosion is similar to any other blast injuries in terms of the release of hot gases, blast wave and metal fragments resulting in extensive skin burns, abrasions, penetrating injury and tissue loss [2-4]. Ocular trauma following gas cylinder explosion is rare however, Babar et al reported 20% of ocular trauma to be secondary to gas cylinder and battery explosion [2]. To our knowledge, this is the first case of facial and eye injury following a fridge cylinder gas explosion reported in the literature.

The sympathetic and sensory innervation of rat airways: origin and neurochemical characterisation

OpenAIRE

Radtke, Anne

2010-01-01

Sensory and sympathetic innervation of Brown Norway rat airways were investigated using retrograde neuronal tracing with fluorescent dyes and double labelling immunofluorescence. Sensory neurons projecting to the lung are located in nodose and jugular vagal ganglia. Sympathetic neuronal supply of the lung originates in the stellate ganglia and superior cervical ganglia. Concerning immuno-reactivity for the SP and NOS in sensory and NPY and TH in sympathetic neurons were investigated. IR for S...

Origins of the sympathetic innervation to the nasal-associated lymphoid tissue (NALT): an anatomical substrate for a neuroimmune connection.

Science.gov (United States)

Marafetti, Lucas E; Romeo, Horacio E

2014-11-15

The participation of sympathetic nerve fibers in the innervation of the nasal-associated lymphoid tissues (NALT) was investigated in hamsters. Vesicular monoamine transporter 2 (VMAT2), an established sympathetic marker, is expressed in all neurons of superior cervical ganglia (SCG). In addition, VMAT2 -immunoreactive nerve fibers were localized in the NALT as well as in adjacent anatomical structures of the upper respiratory tract. Unilateral surgical ablation of the SCG abolished VMAT2 innervation patterns ipsilaterally while the contra lateral side is unaffected. These results provide the anatomical substrate for a neuroimmune connection in the NALT. Copyright © 2014 Elsevier B.V. All rights reserved.

Large eight.cylinder Stirling engine for biofuels

DEFF Research Database (Denmark)

Carlsen, Henrik; Biedermann, F.; Bovin, Jonas Kabell

2003-01-01

A large Stirling engine with an electric power output of 70 kW has been developed for small-scale CHP using wood chips and other sorts of biomass as fuel. The development of the engine is based on the results from the development of a four-cylinder Stirling engine with a power output of 35 k...... in the hot end connecting the expansion space with the hot end of the regenerator through the heater panel. However, this has resulted in comparably large dead volumes and flow losses in the connections between the heater and the regenerator/expansion volume. For the new eight-cylinder engine the design...... of the connections between the heater and the regenerator/expansion volume have been improved considerably, reducing the flow losses and internal dead volume. Results from simulations indicate an improvement of power output and efficiency of about 10%. A four cylinder double acting Stirling engine is basically...

Cortical Reorganization in Dual Innervation by Single Peripheral Nerve.

Science.gov (United States)

Zheng, Mou-Xiong; Shen, Yun-Dong; Hua, Xu-Yun; Hou, Ao-Lin; Zhu, Yi; Xu, Wen-Dong

2017-09-21

Functional recovery after peripheral nerve injury and repair is related with cortical reorganization. However, the mechanism of innervating dual targets by 1 donor nerve is largely unknown. To investigate the cortical reorganization when the phrenic nerve simultaneously innervates the diaphragm and biceps. Total brachial plexus (C5-T1) injury rats were repaired by phrenic nerve-musculocutaneous nerve transfer with end-to-side (n = 15) or end-to-end (n = 15) neurorrhaphy. Brachial plexus avulsion (n = 5) and sham surgery (n = 5) rats were included for control. Behavioral observation, electromyography, and histologic studies were used for confirming peripheral nerve reinnervation. Cortical representations of the diaphragm and reinnervated biceps were studied by intracortical microstimulation techniques before and at months 0.5, 3, 5, 7, and 10 after surgery. At month 0.5 after complete brachial plexus injury, the motor representation of the injured forelimb disappeared. The diaphragm representation was preserved in the "end-to-side" group but absent in the "end-to-end" group. Rhythmic contraction of biceps appeared in "end-to-end" and "end-to-side" groups, and the biceps representation reappeared in the original biceps and diaphragm areas at months 3 and 5. At month 10, it was completely located in the original biceps area in the "end-to-end" group. Part of the biceps representation remained in the original diaphragm area in the "end-to-side" group. Destroying the contralateral motor cortex did not eliminate respiration-related contraction of biceps. The brain tends to resume biceps representation from the original diaphragm area to the original biceps area following phrenic nerve transfer. The original diaphragm area partly preserves reinnervated biceps representation after end-to-side transfer. Copyright © 2017 by the Congress of Neurological Surgeons

77 FR 37712 - High Pressure Steel Cylinders From China

Science.gov (United States)

2012-06-22

...), that an industry in the United States is materially injured by reason of imports of high pressure steel... preliminary determinations by Commerce that imports of high pressure steel cylinders from China were... Publication 4328 (June 2012), entitled High Pressure Steel Cylinders from China: Investigation Nos. 701-TA-480...

Vortex-induced vibrations of a square cylinder under linear shear flow

Energy Technology Data Exchange (ETDEWEB)

Sun, Wenjuan; Zhou, Dai; Han, Zhaolong [School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Tu, Jiahuang, E-mail: tujiahuang1982@163.com, E-mail: han.arkey@gmail.com [College of Civil Engineering and Mechanics, Xiangtan University, Xiangtan, Hunan 411105 (China)

2017-04-15

This paper investigates the numerical vortex-induced vibration (VIV) of a square cylinder which is connected to a 2-DOF mass-spring system and is immersed in the planar shear flow by employing a characteristic-based split (CBS) finite element method (FEM). The reduced mass of the square cylinder is M {sub r} = 2, while the reduced velocity, U {sub r}, is changed from 3 to 12 with an increment of Δ U {sub r} = 1. The effects of some key parameters on the cylinder dynamic responses, vibrating frequencies, the flow patterns as well as the energy transferred between the fluid and cylinder are revealed. In this study, the key parameters are selected as follows: shear ratio ( k  = 0, 0.05 and 0.1) and Reynolds numbers ( Re  = 80 and 160). Numerical results demonstrate that the X – Y trajectories of the cylinder mainly appear as a symmetrical figure ‘8’ in uniform flow ( k  = 0) and an unsymmetrical figure ‘8’ and ‘O’ in shear flows ( k  = 0.05 and 0.1). The maximum oscillation amplitudes of the square cylinder in both the inline and transverse directions have distinct characteristics compared to that of a circular cylinder. Two kinds of flow patterns, ‘2S’ and ‘P + S’, are mainly observed under the shear flow. Also, the mean values of the energy of the cylinder system increase with the reduced velocity, while the root mean square (rms) of the energy reaches its peak value at reduced velocity U {sub r} = 5. (paper)

Rotation of an immersed cylinder sliding near a thin elastic coating

Science.gov (United States)

Rallabandi, Bhargav; Saintyves, Baudouin; Jules, Theo; Salez, Thomas; Schönecker, Clarissa; Mahadevan, L.; Stone, Howard A.

2017-07-01

It is known that an object translating parallel to a soft wall in a viscous fluid produces hydrodynamic stresses that deform the wall, which in turn results in a lift force on the object. Recent experiments with cylinders sliding under gravity near a soft incline, which confirmed theoretical arguments for the lift force, also reported an unexplained steady-state rotation of the cylinders [B. Saintyves et al., Proc. Natl. Acad. Sci. USA 113, 5847 (2016), 10.1073/pnas.1525462113]. Motivated by these observations, we show, in the lubrication limit, that an infinite cylinder that translates in a viscous fluid parallel to a soft wall at constant speed and separation distance must also rotate in order to remain free of torque. Using the Lorentz reciprocal theorem, we show analytically that for small deformations of the elastic layer, the angular velocity of the cylinder scales with the cube of the sliding speed. These predictions are confirmed numerically. We then apply the theory to the gravity-driven motion of a cylinder near a soft incline and find qualitative agreement with the experimental observations, namely, that a softer elastic layer results in a greater angular speed of the cylinder.

Buckling behaviour of imperfect ring-stiffened cone-cylinder intersections under internal pressure

International Nuclear Information System (INIS)

Zhao, Y.

2005-01-01

Cone-cylinder intersections are used commonly in pressure vessels and piping. In the case of a cone large end-to-cylinder intersection under internal pressure, the intersection is subject to a large circumferential compressive force. While both the cone and the cylinder may be locally thickened to strengthen the intersection, it is often desirable and convenient to provide an annular plate ring at the cone-to-cylinder joint to supplement local thickening or as an alternative strengthening measure, leading to a ring-stiffened cone-cylinder intersection. Only limited work has been carried out specifically on ring-stiffened cone-cylinder intersections under internal pressure. This paper presents the first experimental study on such intersections. In addition to the presentation of test results including geometric imperfections, failure behaviour and the determination of buckling mode and load based on displacement measurements, results from nonlinear bifurcation analysis using the perfect shape and nonlinear analysis using the measured imperfect shape are presented and compared with the experimental results

Morfofisiologia da inervação do diafragma de ovinos Morphophysiology of diaphragm innervation in sheep

Directory of Open Access Journals (Sweden)

Ana E.F. de Almeida

2008-09-01

Full Text Available Foram estudados em 30 diafragmas de ovinos da raça Santa Inês, a origem, a divisão e a distribuição dos nervos frênicos direito e esquerdo (Fde e a participação de outros nervos na inervação do diafragma. Mediante fixação e dissecação das peças foi observado que os nervos frênicos (F originam-se a partir dos ramos ventrais do 5º (C5 e 6º (C6 nervos espinhais cervicais (Ec tanto à direita (46,67% como à esquerda (43,33%. Os F finalizam em tronco lombocostal e ramo esternal à direita (40,00% e em ramo lombar, costal e esternal à esquerda (36,68%. Os ramos lombares dos F inervam à esquerda (96,67% o pilar homolateral do diafragma e, à direita (50,00% fornecem filetes à veia caudal. Os ramos costais dos F ramificam à esquerda (90,00% e à direita (76,67% as regiões dorsal e ventral da pars costalis. Os ramos esternais dos F inervam à direita (100,00% e à esquerda (83,33% a pars sternalis e a região ventral da pars costalis do mesmo lado. Os nervos intercostais (VIII ao XII pares, 63,33% contribuem na inervação do diafragma de ovinos da raça Santa Inês.Thirty diaphragms of sheep of Santa Inês breed were studied regarding their origin, division and arrangement of the right and left phrenic nerves (Fde, and the participation of other nerves in the innervation of the diaphragm. By fixing and dissecting pieces, it was found that phrenic nerves (F frequently come from the ventral branches of the 5th (C5 and 6th (C6 cervical spinal nerves (Ec, at right (46.67% and at left (43.33%. The F often form a lumbocostal trunk, sternal branches at right (40.00% and lumbar, costal and esternal branches at left (36.68%. The lumbar branches of F innervate frequently at left (96.67% the homolateral pillar of the diaphragma, and at right (50.00% they give fillets to Vena cava caudalis. The costal branches of the F innervate at left (90.00% and at right (76.66% the dorsal and ventral regions of the pars costalis. The sternal branches of

CYLINDER OF THE DISPOSABLE MASS EXCHANGE DEVICE FOR HEMOSORPTION

Directory of Open Access Journals (Sweden)

F. I. Kazakov

2015-01-01

Full Text Available BACKGROUND. Hemocarboperfusion, previously widely used in our country, can universally pass out of use due to the lack of industrial production of disposable mass exchange devices.MATERIAl AND METHODS. Physicochemical properties of materials and design features of the body samples elements of various sizes have been studied.RESULTS. The elements and materials properties of the hemosorption mass exchanger cylinder have been studied. Hydrodynamic parameters of manipulation using the developed cylinders at different perfusion rates have been studied in bench experiments.CONCLUSION. The original cylinder of the disposable mass exchange device for hemosorption, which meets the current clinical needs, has been developed. 

Finite-size resonance dielectric cylinder in a rectangular waveguide

International Nuclear Information System (INIS)

Chuprina, V.N.; Khizhnyak, N.A.

1988-01-01

The problem on resonance spread of an electromagnetic wave by a dielectric circular cylinder of finite size in a rectangular waveguide is solved by a numerical-analytical method. The cylinder axes are parallel. The cylinder can be used as a resonance tuning element in accelerating SHF-sections. Problems on cutting off linear algebraic equation systems, to which relations of macroscopic electrodynamics in the integral differential form written for the concrete problem considered here are reduced by analytical transformations, are investigated in the stage of numerical analysis. Theoretical dependences of the insertion of the voltage standing wave coefficient on the generator wave length calculated for different values of problem parameters are constracted

Speed-variable Switched Differential Pump System for Direct Operation of Hydraulic Cylinders

DEFF Research Database (Denmark)

Schmidt, Lasse; Roemer, Daniel Beck; Pedersen, Henrik Clemmensen

2015-01-01

differential cylinders. The main idea was here to utilize an electric rotary drive, with the shaft interconnected to two antiparallel fixed displacement gear pumps, to actuate a differential cylinder. With the design carried out such that the area ratio of the cylinder matches the displacement ratio of the two...

Induced-charge electroosmosis around conducting and Janus cylinder in microchip

Directory of Open Access Journals (Sweden)

Zhang Kai

2012-01-01

Full Text Available The induced-charge elecetroosmosis around conducting/Janus cylinder with arbitrary Debye thickness is studied numerically, when an direct current weak electric filed is suddenly applied in a confined microchannel. It’s found that there are four large circulations around the conducting cylinder, and the total flux in the microchannel is zero; there are two smaller circulations around the Janus cylinder, and they are compressed to wall. A bulk flux, which has a parabolic relation with the applied electric field, is also predicted.

Performance of a Horizontal Triple Cylinder Type Pulping Machine

Directory of Open Access Journals (Sweden)

Sukrisno Widyotomo

2011-05-01

Full Text Available Pulping is one important step in wet coffee processing method. Pulping process usually uses a machine which constructed by wood or metal materials. A horizontal single cylinder type of fresh coffee cherries pulping machine is the most popular machine in coffee processing. One of the weaknesses of a horizontal single cylinder type of fresh coffee cherries pulping machine is higher in broken beans. Broken bean is one of mayor aspects in defect system that contribute to low quality. Indonesian Coffee and Cocoa Research Institute has designed and tested a horizontal double cylinder type of fresh coffee cherries pulping machine which resulted in 12.6—21.4% of broken beans. To reduce percentage of broken beans, Indonesian Coffee and Cocoa Research Institute has developed and tested a horizontal triple cylinder type of fresh coffee cherries pulping machine. Material tested was fresh mature Robusta coffee cherries, 60—65% (wet basis moisture content; has classified on 3 levels i.e. unsorted, small and medium, and clean from metal and foreign materials. The result showed that the machine produced 6,340 kg/h in optimal capacity for operational conditions, 1400 rpm rotor rotation speed for unsorted coffee cherries with composition 55.5% whole parchment coffee, 3.66% broken beans, and 1% beans in wet skin.Key words : coffee, pulp, pulper, cylinder, quality.

The thoracic muscular system and its innervation in third instar Calliphora vicina Larvae. II. Projection patterns of the nerves associated with the pro- and mesothorax and the pharyngeal complex.

Science.gov (United States)

Schoofs, Andreas; Hanslik, Ulrike; Niederegger, Senta; Heinzel, Hans-Georg; Spiess, Roland

2010-08-01

We describe the anatomy of the nerves that project from the central nervous system (CNS) to the pro- and mesothoracic segments and the cephalopharyngeal skeleton (CPS) for third instar Calliphora larvae. Due to the complex branching pattern we introduce a nomenclature that labels side branches of first and second order. Two fine nerves that were not yet described are briefly introduced. One paired nerve projects to the ventral arms (VAs) of the CPS. The second, an unpaired nerve, projects to the ventral surface of the cibarial part of the esophagus (ES). Both nerves were tentatively labeled after the structures they innervate. The antennal nerve (AN) innervates the olfactory dorsal organ (DO). It contains motor pathways that project through the frontal connectives (FC) to the frontal nerve (FN) and innervate the cibarial dilator muscles (CDM) which mediate food ingestion. The maxillary nerve (MN) innervates the sensory terminal organ (TO), ventral organ (VO), and labial organ (LO) and comprises the motor pathways to the mouth hook (MH) elevator, MH depressor, and the labial retractor (LR) which opens the mouth cavity. An anastomosis of unknown function exists between the AN and MN. The prothoracic accessory nerve (PaN) innervates a dorsal protractor muscle of the CPS and sends side branches to the aorta and the bolwig organ (BO) (stemmata). In its further course, this nerve merges with the prothoracic nerve (PN). The architecture of the PN is extremely complex. It innervates a set of accessory pharyngeal muscles attached to the CPS and the body wall musculature of the prothorax. Several anastomoses exist between side branches of this nerve which were shown to contain motor pathways. The mesothoracic nerve (MeN) innervates a MH accessor and the longitudinal and transversal body wall muscles of the second segment. J. Morphol. 271:969-979, 2010. (c) 2010 Wiley-Liss, Inc.

Sound insulation of composite cylindrical shells: a comparison between a laminated and a sandwich cylinder

OpenAIRE

Yuan, Chongxin; Roozen, Bert; Bergsma, Otto; Beukers, Adriaan

2012-01-01

The fuselages of aircraft are modeled as a cylinder in this paper, and the sound insulations of a sandwich cylinder and a laminated cylinder are studied both experimentally and numerically. The cylinders are excited by an acoustic pressure and a mechanical force respectively. Results show that under acoustic excitation, the sandwich cylinder and the laminated one have a similar sound insulation below 3000 Hz, but the sandwich cylinder has a much larger sound insulation at higher frequencies. ...

Scattering cross-section of an inhomogeneous plasma cylinder

International Nuclear Information System (INIS)

Jiaming Shi; Lijian Qiu; Ling, Y.

1995-01-01

Scattering of em waves by the plasma cylinder is of significance in radar target detection, plasma diagnosis, etc. This paper discusses the general method to calculate the scattering cross-section of em waves from a plasma cylinder which is radially inhomogeneous and infinitely long. Numerical results are also provided for several plasma density profiles. The effect of the electron density distribution on the scattering cross-section is investigated

Force Control for a Pneumatic Cylinder Using Generalized Predictive Controller Approach

Directory of Open Access Journals (Sweden)

Ahmad ’Athif Mohd Faudzi

2014-01-01

Full Text Available Pneumatic cylinder is a well-known device because of its high power to weight ratio, easy use, and environmental safety. Pneumatic cylinder uses air as its power source and converts it to a possible movement such as linear and rotary movement. In order to control the pneumatic cylinder, controller algorithm is needed to control the on-off solenoid valve with encoder and pressure sensor as the feedback inputs. In this paper, generalized predictive controller (GPC is proposed as the control strategy for the pneumatic cylinder force control. To validate and compare the performance, proportional-integral (PI controller is also presented. Both controllers algorithms GPC and PI are developed using existing linear model of the cylinder from previous research. Results are presented in simulation and experimental approach using MATLAB-Simulink as the platform. The results show that the GPC is capable of fast response with low steady state error and percentage overshoot compared to PI.

Chemical aspects of cylinder corrosion and a scenario for hole development

Energy Technology Data Exchange (ETDEWEB)

Barber, E.J. [Martin Marietta Energy Systems, Oak Ridge, TN (United States)

1991-12-31

In June 1990, two cylinders in the depleted UF{sub 6} cylinder storage yards at Portsmouth were discovered to have holes in their walls at the valve-end stiffening ring at a point below the level of the gas-solid interface of the UF{sub 6}. The cylinder with the larger hole, which extended under the stiffening ring, was stacked in a top row 13 years ago. The cylinder with the smaller hole had been stacked in a bottom row 4 years ago. The lifting lugs of the adjacent cylinders pointed directly at the holes. A Cylinder Investigating Committee was appointed to determine the cause or causes of the holes and to assess the implications of these findings. This report contains a listing of the chemically related facts established by the Investigating Committee with the cooperation of the Operations and Technical Support Divisions at the Portsmouth Gaseous Diffusion Plant, the scenario developed to explain these findings and some implications of this scenario. In summary, the interrelated reactions of water, solid UF{sub 6} and iron presented by R. L. Ritter are used to develop a scenario which explains the observations and deductions made during the investigation. The chemical processes are intimately related to the course of the last three of the four stages of hole development. A simple model is proposed which permits semiquantitative prediction of such information as the HF loss rates as a function of time, the rate of hole enlargement, the time to hydrolyze a cylinder of UF{sub 6} and the approximate size of the hole. The scenario suggests that the environmental consequences associated with a developing hole in a depleted UF{sub 6} cylinder are minimal for the first several years but will become significant if too many years pass before detection. The overall environmental picture is presented in more detail elsewhere.

Innervated boomerang flap for finger pulp reconstruction.

Science.gov (United States)

Chen, Shao-Liang; Chiou, Tai-Fung

2007-11-01

The boomerang flap originates from the dorsolateral aspect of the proximal phalanx of an adjacent digit and is supplied by the retrograde blood flow through the vascular arcades between the dorsal and palmar digital arteries. To provide sensation of the boomerang flap for finger pulp reconstruction, the dorsal sensory branch of the proper digital nerve and the superficial sensory branch of the corresponding radial or ulnar nerve are included within the skin flap. After transfer of the flap to the injured site, epineural neurorrhaphies are done between the digital nerves of the pulp and the sensory branches of the flap. We used this sensory flap in five patients, with more than 1 year follow-up, and all patients achieved measurable two-points discrimination. The boomerang flap not only preserves the proper palmar digital artery but also provides an extended and innervated skin paddle. It seems to be an alternative choice for one-stage reconstruction of major pulp defect.

Re-examination of laminar flow over twin circular cylinders in tandem arrangement

Energy Technology Data Exchange (ETDEWEB)

Liu, Ming-Ming; Lu, Lin; Teng, Bin; Tang, Guo-Qiang [State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116024 (China); Zhao, Ming [School of Computing, Engineering and Mathematics, University of Western Sydney, Penrith 2751 (Australia)

2014-04-01

Viscous fluid flow past two identical circular cylinders in a tandem arrangement is numerically investigated at a typical Reynolds number of 200. By considering a large span of spacing ratio (0.1 ⩽ G/D ⩽ 6.0) with a fine interval of 0.1 or less, the dependences on the spacing ratio of the drag force, lift force, lift fluctuation frequency, torque on the cylinder pair and phase difference between the lift fluctuations of the two cylinders are investigated in detail, where D is the diameter of the cylinder and G the surface-to-surface distance between the cylinders. The phase difference between the lift fluctuations of the two cylinders is addressed based on correlation analysis together with the phase diagram, which has received scarce attention before. The phase difference provides further understanding to the dependence of the wake evolutions behind the twin circular cylinders. The numerical investigations show that diverse regimes can be identified according to the dependence of the hydrodynamics on the spacing ratio. The hydrodynamic discontinuities at G/D = 0.9, which have previously been ignored, are reported in this work. The physical correlations between the hydrodynamic discontinuities and the wake patterns are presented. (paper)

Re-examination of laminar flow over twin circular cylinders in tandem arrangement

International Nuclear Information System (INIS)

Liu, Ming-Ming; Lu, Lin; Teng, Bin; Tang, Guo-Qiang; Zhao, Ming

2014-01-01

Viscous fluid flow past two identical circular cylinders in a tandem arrangement is numerically investigated at a typical Reynolds number of 200. By considering a large span of spacing ratio (0.1 ⩽ G/D ⩽ 6.0) with a fine interval of 0.1 or less, the dependences on the spacing ratio of the drag force, lift force, lift fluctuation frequency, torque on the cylinder pair and phase difference between the lift fluctuations of the two cylinders are investigated in detail, where D is the diameter of the cylinder and G the surface-to-surface distance between the cylinders. The phase difference between the lift fluctuations of the two cylinders is addressed based on correlation analysis together with the phase diagram, which has received scarce attention before. The phase difference provides further understanding to the dependence of the wake evolutions behind the twin circular cylinders. The numerical investigations show that diverse regimes can be identified according to the dependence of the hydrodynamics on the spacing ratio. The hydrodynamic discontinuities at G/D = 0.9, which have previously been ignored, are reported in this work. The physical correlations between the hydrodynamic discontinuities and the wake patterns are presented. (paper)

How many oxygen cylinders do you need to take on transport? A nomogram for cylinder size and duration.

Science.gov (United States)

Lutman, D; Petros, A J

2006-09-01

When undertaking patient retrieval, it is important to take adequate supplies of oxygen to ensure patient safety. Oxygen can be delivered via a flowmeter into a facemask or used to drive pneumatic ventilators. Given the lack of space in the back of an ambulance or helicopter, the numbers of cylinders that can be taken is limited, hence the number needed to complete the journey must be carefully calculated prior to embarking. We have produced nomograms to predict how many oxygen cylinders will be consumed during a given journey when using either a flowmeter or a commonly used transport ventilator.

[Microscopic innervation of the spermatic ducts and testis. I. Vas deferens].

Science.gov (United States)

Suárez-Garnacho, S; Vega, J A; Alvarez Arenal, A; Pérez Casas, A; Alvarez Menéndez, J C; Hernández, L C

1989-01-01

The microscopic innervation of the vas deferens in the rat was studied both in light and electron microscope. The nerve fibres form perivascular, intramuscular and subepithelial plexuses. Inside the connective tissue surrounding the vas deferens both isolated nerve fibres and sensory corpuscles (glomerular and Ruffine-like types) were observed. The varicosities and endings of nerve fibres contain synaptic vesicles of different sizes and electron characteristics. These varicosities were closely related to the smooth muscle cells and some of them lacked of Schwannian sheath. The nervous fibres were not in direct contact with the epithelial cells.

Buckling Experiment on Anisotropic Long and Short Cylinders

Directory of Open Access Journals (Sweden)

Atsushi Takano

2016-07-01

Full Text Available A buckling experiment was performed on anisotropic, long and short cylinders with various radius-to-thickness ratios. The 13 cylinders had symmetric and anti-symmetric layups, were between 2 and 6 in terms of the length-to-radius ratio, between 154 and 647 in radius-to-thickness ratio, and made of two kinds of carbon fiber reinforced plastic (CFRP prepreg with high or low fiber modulus. The theoretical buckling loads for the cylinders were calculated from the previously published solution by using linear bifurcation theory considering layup anisotropy and transverse shear deformation and by using deep shell theory to account for the effect of length and compared with the test results. The theoretical buckling loads for the cylinders were calculated from the previously published solution by using linear bifurcation theory considering layup anisotropy and transverse shear deformation and by using deep shell theory to account for the effect of length. The knockdown factor, defined as the ratio of the experimental value to the theoretical value, was found to be between 0.451 and 0.877. The test results indicated that a large length-to-radius ratio reduces the knockdown factor, but the radius-to-thickness ratio and other factors do not affect it.

Wave propagation in coated cylinders with reference to fretting fatigue

Indian Academy of Sciences (India)

is to study stress wave propagation in cylinders with reference to high frequency fretting. ... The motivation for studying of fretting fatigue at higher frequency is to investigate the ... Hence focus in this work is given to thin rods and cylinders. The.

Flow past an axially aligned spinning cylinder: Experimental Study

Science.gov (United States)

Carlucci, Pasquale; Buckley, Liam; Mehmedagic, Igbal; Carlucci, Donald; Thangam, Siva

2017-11-01

Experimental investigation of flow past a spinning cylinder is presented in the context of its application and relevance to flow past projectiles. A subsonic wind tunnel is used to perform experiments on the flow past a spinning cylinder that is mounted on a forward sting and oriented such that its axis of rotation is aligned with the mean flow. The experiments cover a Reynolds number of range of up to 45000 and rotation numbers of up to 2 (based on cylinder diameter). Time-averaged mean flow and turbulence profiles in the wake flow are presented with and without spin along with comparison to published experimental data. Funded in part by the U. S. Army ARDEC, Picatinny Arsenal, NJ.

The Friction of Vehicle Brake Tandem Master Cylinder

International Nuclear Information System (INIS)

Kao, M J; Chang, H; Tsung, T T; Lin, H M

2006-01-01

The behaviour of an elastomeric seal for vehicle brake Tandem master cylinder is measured and analyzed in temperature and brake fluids changed. Working conditions are simulated for different piston rod velocity and cylinder supply pressure, in temperature rising, brakefluid boundary and Nanoaluminum oxide brakefluid oxide brakefluid lubrication. The result shows that Nanoaluminum oxide brakefluid with its ball shape can highly reduce friction coefficient to avoid seal excessive wear and reduce slick slip in brake applications

Radiation dose rates from UF{sub 6} cylinders

Energy Technology Data Exchange (ETDEWEB)

Friend, P.J. [Urenco, Capenhurst (United Kingdom)

1991-12-31

This paper describes the results of many studies, both theoretical and experimental, which have been carried out by Urenco over the last 15 years into radiation dose rates from uranium hexafluoride (UF{sub 6}) cylinders. The contents of the cylinder, its history, and the geometry all affect the radiation dose rate. These factors are all examined in detail. Actual and predicted dose rates are compared with levels permitted by IAEA transport regulations.

Mobile Robot Localization by Remote Viewing of a Colored Cylinder

Science.gov (United States)

Volpe, R.; Litwin, T.; Matthies, L.

1995-01-01

A system was developed for the Mars Pathfinder rover in which the rover checks its position by viewing the angle back to a colored cylinder with different colors for different angles. The rover determines distance by the apparent size of the cylinder.

Spatiotemporal dynamics of re-innervation and hyperinnervation patterns by uninjured CGRP fibers in the rat foot sole epidermis after nerve injury

Directory of Open Access Journals (Sweden)

Duraku Liron S

2012-08-01

Full Text Available Abstract The epidermis is innervated by fine nerve endings that are important in mediating nociceptive stimuli. However, their precise role in neuropathic pain is still controversial. Here, we have studied the role of epidermal peptidergic nociceptive fibers that are located adjacent to injured fibers in a rat model of neuropathic pain. Using the Spared Nerve Injury (SNI model, which involves complete transections of the tibial and common peroneal nerve while sparing the sural and saphenous branches, mechanical hypersensitivity was induced of the uninjured lateral (sural and medial (saphenous area of the foot sole. At different time points, a complete foot sole biopsy was taken from the injured paw and processed for Calcitonin Gene-Related Peptide (CGRP immunohistochemistry. Subsequently, a novel 2D-reconstruction model depicting the density of CGRP fibers was made to evaluate the course of denervation and re-innervation by uninjured CGRP fibers. The results show an increased density of uninjured CGRP-IR epidermal fibers on the lateral and medial side after a SNI procedure at 5 and 10 weeks. Furthermore, although in control animals the density of epidermal CGRP-IR fibers in the footpads was lower compared to the surrounding skin of the foot, 10 weeks after the SNI procedure, the initially denervated footpads displayed a hyper-innervation. These data support the idea that uninjured fibers may play a considerable role in development and maintenance of neuropathic pain and that it is important to take larger biopsies to test the relationship between innervation of injured and uninjured nerve areas.

Cylinder head seal for piston engines especially internal combustion engines. Zylinderkopfdichtung fuer Hubkolbenmaschinen, insbesondere Brennkraftmaschinen

Energy Technology Data Exchange (ETDEWEB)

Kubis, H.; Winter, J.

1991-01-17

The invention concerns a cylinder head seal for reciprocating piston engines especially internal combustion engines and preferentially those with cylinder sleeves. With performances of internal combustion engines encreasing all the time it is becoming more and more difficult to seal the cylinder heat. The invention proposes a ring seal whose sides are plastically deformed when the cylinder headed screws are tightened. The inner deformations of the cylinder head resulting from the pressure forces inside the cylinder are compensated by means of elastic spring action of the combustion chamber sealing ring. The dimension of land, groove and sides are matched in such a way as to prevent any seal squeezing during plastification which would result in a deformation of the cylinder sleeve. The ring can therefore be set directly into the centering of the cylinder sleeve. Separate centering devices are not required.

Mechanical Integrity of Copper Canister Lid and Cylinder

International Nuclear Information System (INIS)

Karlsson, Marianne

2002-01-01

This report compiles finite element analyses performed to ensure the structural integrity of canisters used for storing of nuclear fuel waste of type BWR. The report comprises analyses performed on the canister lid and cylinder casing in order to determine static and long-term strength of the structure. The report analyses the mechanical response of the lid and flange of the copper canister when subjected to loads caused by pressure from swelling bentonite and from ground water at a depth of 500 meter. The loads acting on the canister are somewhat uncertain and the cases investigated in this report are possible cases. Load cases analysed are: Pressure 15 MPa uniformly distributed on lid and 5 MPa uniformly distributed on cylinder; Pressure 5 MPa uniformly distributed on lid and 15 MPa uniformly distributed on cylinder; Pressure 20 MPa uniformly distributed on lid and cylinder; Side pressures 10 MPa and 20 MPa uniformly distributed on part of the cylinder. Creep analyses are also performed in order to estimate the stresses that will arise when the canister is placed in the repository. The analyses in this report are recreated from the original analyses but the models differ in geometry. Also, there is no information in the original reports on material data, time-independent as well as creep data, and analysis procedure. The data used in the recreated analyses are based on information from References 2, 3, 6 and 7. The results presented in this report are based on the supplementary analyses. These results differ from the original results. Most likely this is due to differences in model geometry. The original results are appended to the report and are summarised for comparison with results from the supplementary analyses. Otherwise, these results are not further discussed. For all load cases, high tensile stresses are found in the lid fillet between the planar part and the flange. High tensile stresses are also found in the weld surface and on the outer side of the

Wave forces on cylinder submerged horizontally in shallow water

Energy Technology Data Exchange (ETDEWEB)

Mitani, H; Sasaki, K; Kobayashi, T; Nomura, N; Kawabe, H; Sugimoto, H

1976-12-01

To estimate the wave forces on offshore and/or coastal structures, the ideal method is undoubtedly to obtain the more accurate solution of hydrodynamic equations under suitable boundary conditions. However, in practice, it is difficult to introduce precise solutions under present technical levels because some important problems still remain. Among them is the unsteady boundary layers with separation around the objects. Consequently, every effort is being made in this field to approximate these conditions. Among these approximations, the Diffraction Wave Theory and the Morrison's Method are the most famous means in practice, although both still have some problems. Some problems with the traditional Finite Amplitude Wave Theories such as Stokes and Cnoidal Wave Theories are examined, and by applying additional computed results to the Morrison's formula, the estimated formula for wave forces on a cylinder submerged horizontally in shallow water is introduced. Subsequently, the applicability of the formula and also the specific characteristics of wave forces on a horizontally settled cylinder are investigated in detail, attaching first importance to the distinctions from the vertically settled cylinder, based on the comparison of computed results with experimental results. The experiments were carried out on two different diameters of cylinder, 70 mm and 140 mm, and bottom slopes of the experimental tanks, /sup 1///sub 100/ and /sup 1///sub 30/, under various conditions varying water depth, wave period, wave height and also setting position of cylinder.

For Vol.67, No.5 pp325-331 Phalloplasty with an Innervated Island Pedicled Anterolateral Thigh Flap in a Female-to-Male Transsexual

OpenAIRE

Hasegawa, Kenjiro; Namba, Yuzaburo; Kimata, Yoshihiro

2014-01-01

Since 2001, we have been performing phalloplasty with a radial forearm free flap as the flap of firstchoice in female-to-male transsexuals (FTMTS). In the present case, a 22-year-old FTMTS with anegative Allen test, we achieved good results by performing phalloplasty with an innervated islandpedicled anterolateral thigh flap using the “tube within a tube” technique, in which the penis and urethraare constructed with a single flap. As compared to a forearm flap, use of an innervated islandpedi...

Thermal convection of liquid sodium in inclined cylinders

Science.gov (United States)

Khalilov, Ruslan; Kolesnichenko, Ilya; Pavlinov, Alexander; Mamykin, Andrey; Shestakov, Alexander; Frick, Peter

2018-04-01

The effect of inclination on the low Prandtl number turbulent convection in a cylinder of unit aspect ratio was studied experimentally. The working fluid was sodium (Prandtl number Pr =0.0094 ), the measurements were performed for a fixed Rayleigh number Ra =(1.47 ±0.03 ) ×107 , and the inclination angle varied from β =0∘ (the Rayleigh-Bénard convection, the temperature gradient is vertical) up to β =90∘ (the applied temperature gradient is horizontal) with a step Δ β =10∘ . The effective axial heat flux characterized by the Nusselt number is minimal at β =0∘ and demonstrates a smooth growth with the increase of the cylinder inclination, reaching a maximum at angle β ≈70∘ and decreasing with a further increase of β . The maximal value of the normalized Nusselt number Nu (β )/Nu (0 ) was 1.21. In general, the dependence of Nu (β ) in a cylinder with unit aspect ratio is similar to what was observed in sodium convection in inclined long cylinders but is much weaker. The structure of the flow undergoes a significant transformation with inclination. Under moderate inclination (β ≲30∘ ), the fluctuations are strong and are provided by regular oscillations of large-scale circulation (LSC) and by turbulence. Under large inclination (β >60∘ ), the LSC is regular and the turbulence is weak, while in transient regimes (30∘border of transient and large inclinations. We find the first evidence of strong LSC fluctuations in low Prandtl number convective flow under moderate inclination. The rms azimuthal fluctuations of LSC, about 27∘ at β =0∘ , decrease almost linearly up to β =30∘ , where they are about 9∘. The angular fluctuations in the vicinity of the end faces are much stronger (about 37∘ at β =0∘ ) and weakly decrease up to β =20∘ . The strong anticorrelation of the fluctuations in two halves of the cylinder indicates the torsional character of LSC fluctuations. At β =30∘ , the intensity of the oscillations at the

Numerical simulation of VAWT on the effects of rotation cylinder

Science.gov (United States)

Xing, Shuda; Cao, Yang; Ren, Fuji

2017-06-01

Based on Finite Element Analysis Method, studying on Vertical Axis Wind Turbine (VAWT) which is added rotating cylinder in front of its air foils, especially focusing on the analysis of NACA6 series air foils about variation of lift to drag ratio. Choosing the most suitable blades with rotary cylinder added on leading edge. Analysis indicates that the front rotating cylinders on the VAWT is benefit to lift rise and drag fall. The most suitable air foil whose design lift coefficient is 0.8, the blades relative thickness is 20%, and the optimistic tip speed ratio is about 7.

Anomalous Innervation of the Median Nerve in the Arm in the Absence of the Musculocutaneous Nerve

Directory of Open Access Journals (Sweden)

Khursheed Raza

2017-03-01

Full Text Available The brachial plexus innervates the upper extremities. While variations in the formation of the brachial plexus and its terminal branches are quite common, it is uncommon for the median nerve to innervate the muscles of the arm. During the dissection of an elderly male cadaver at the Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India, in 2016, the coracobrachialis muscle was found to be supplied by a direct branch from the lateral root of the median nerve and the musculocutaneous nerve was absent. The branches of the median nerve supplied the biceps brachii and brachialis muscles and the last branch continued as the lateral cutaneous nerve of the forearm. These variations may present atypically in cases of arm flexor paralysis or sensory loss on the lateral forearm. Knowledge of these variations is important in surgeries and during the administration of regional anaesthesia near the shoulder joint and upper arm.

Criticality concerns in cleaning large uranium hexafluoride cylinders

International Nuclear Information System (INIS)

Sheaffer, M.K.; Keeton, S.C.; Lutz, H.F.

1995-06-01

Cleaning large cylinders used to transport low-enriched uranium hexafluoride (UF 6 ) presents several challenges to nuclear criticality safety. This paper presents a brief overview of the cleaning process, the criticality controls typically employed and their bases. Potential shortfalls in implementing these controls are highlighted, and a simple example to illustrate the difficulties in complying with the Double Contingency Principle is discussed. Finally, a summary of recommended criticality controls for large cylinder cleaning operations is presented

Lift and Drag on Cylinder of Octagonal Cross-Section in a Turbulent Stream

Directory of Open Access Journals (Sweden)

Md. Jomir Hossain

2013-12-01

Full Text Available An experimental investigation of surface static pressure distributions on octagonal cylinder in uniform and turbulent flows was carried out. The study was performed on both the single cylinder and the group of two cylinders, two cylinders were used, one was at the upstream side, and the other was at the downstream side of the flow. They were placed centrally along the flow direction. The inter-spacing space between the two cylinders was varied at 1D, 2D, 3D, 4D, 5D, 6D, 7D and 8D, where D is the width of the cylinder across the flow direction. The pressure coefficients were calculated from the measured values of the surface static pressure distribution on the cylinder. Then the drag and lift coefficients were obtained from the pressure coefficients by the numerical integration method. It was observed that at various angles of attack, the values of the lift coefficients and drag coefficients were insignificant compared to those for a sharp-edged square cylinder. The strength of the vortex shedding was shown to be reduced as the intensity of the incident turbulence was increased. Measurements of drag at various angles of attack (0° to 40° showed that with increase in turbulence level the minimum drag occurred at smaller values of angle of attack.

THE INTERACTION OF A COLD ATOMISED SPRAY WITH A CIRCULAR CYLINDER

Directory of Open Access Journals (Sweden)

A. AROUSSI

2010-09-01

Full Text Available The development of non-intrusive diagnostic techniques has significantly increased with the introduction of lasers. Laser based anemometry, such as Laser Doppler (LDA, Phase Doppler (PDA, and Particle Image Velocimetery (PIV can provide an accurate description of flows without interference. This study determines experimentally the fluid motion resulting from the interaction of a liquid spray with a circular cylinder. Two experimental settings were examined: the first is a discharging spray into free air and the second is a spray impinging on a circular cylinder placed 25 cylinder diameters downstream of the nozzle. These sprays were quantified using PIV. A non-intrusive droplet sizing technique was used to characterise the spray. This has shown that, within the spray, the average droplet diameter increases when the circular cylinder is introduced and so does the frequency of occurrence of these large droplets. In the wake behind the cylinder, the smaller droplets were quickly entrained and recirculated, while the larger droplets continued in the general direction of the spray cone.

Cylinder components properties, applications, materials

CERN Document Server

2016-01-01

Owing to the ever-increasing requirements to be met by gasoline and diesel engines in terms of CO2 reduction, emission behavior, weight, and service life, a comprehensive understanding of combustion engine components is essential today. It is no longer possible for professionals in automotive engineering to manage without the corresponding expertise, whether they work in the field of design, development, testing, or maintenance. This technical book provides in-depth answers to questions about design, production, and machining of cylinder components. In this second edition, every section has been revised and expanded to include the latest developments in the combustion engine. Content Piston rings Piston pins and piston pin circlips Bearings Connecting rods Crankcase and cylinder liners Target audience Engineers in the field of engine development and maintenanceLecturers and students in the areas of mechanical engineering, engine technology, and vehicle constructionAnyone interested in technology Publisher MAH...

Development of Flexible Pneumatic Cylinder with Built-in Flexible Linear Encoder and Flexible Bending Sensor

Science.gov (United States)

Akagi, Tetsuya; Dohta, Shujiro; Matsushita, Hisashi; Fukuhara, Akimasa

The purpose of this study is to develop a lightweight and intelligent soft actuator which can be safely attached to the human body. A novel flexible pneumatic cylinder that can be used even if it is deformed by external force had been proposed. The cylinder can realize both pushing and pulling motions even if the cylinder bends. In this paper, a flexible pneumatic cylinder with a built-in flexible linear encoder is proposed and tested. The encoder can detect the cylinder displacement even if the cylinder bends. In the next step, to realize an intelligent flexible cylinder, it is essential to recognize the angle of deflection of the cylinder to estimate the direction of the external force. Therefore, a flexible bending sensor that can measure the directional angle by attaching it to the end of the cylinder is also proposed and tested. The tested bending sensor also consists of four inexpensive photo-reflectors set on the circumferential surface to the cylinder tube every 90 degrees from the center of the tube. By measuring the distance between the photo reflector and the surface of the tube at each point, the bending directional angle of the cylinder can be obtained. A low cost measuring system using a micro-computer incorporating a programmed Up/Down counter to measure the displacement of the cylinder is also developed. As a result, it was confirmed that the measuring accuracy of the bending directional angle was good, less than 0.7 degrees as a standard deviation.

Natural phenomena evaluations of the K-25 site UF6 cylinder storage yards

International Nuclear Information System (INIS)

Fricke, K.E.

1996-01-01

The K-25 Site UF 6 cylinder storage yards are used for the temporary storage of UF 6 normal assay cylinders and long-term storage of other UF 6 cylinders. The K-25 Site UF 6 cylinder storage yards consist of six on-site areas: K-1066-B, K-1066-E, K-1066-F, K-1066-J, K-1066-K and K-1066-L. There are no permanent structures erected on the cylinder yards, except for five portable buildings. The operating contractor for the K-25 Site is preparing a Safety Analysis Report (SAR) to examine the safety related aspects of the K-25 Site UF 6 cylinder storage yards. The SAR preparation encompasses many tasks terminating in consequence analysis for the release of gaseous and liquid UF 6 , one of which is the evaluation of natural phenomena threats, such as earthquakes, floods, and winds. In support of the SAR, the six active cylinder storage yards were evaluated for vulnerabilities to natural phenomena, earthquakes, high winds and tornados, tornado-generated missiles, floods (local and regional), and lightning. This report summarizes those studies. 30 refs

Fundamental study on nuclear medicine imaging of cholinergic innervation in the brain; Changes of neurotransmitter and receptor in animal model of Alzheimer's disease

Energy Technology Data Exchange (ETDEWEB)

Matsuda, Hiroshi; Kinuya, Keiko; Sumiya, Hisashi; Hisada, Kinichi [Kanazawa Univ. (Japan). School of Medicine; Tsuji, Shiro; Terada, Hitoshi; Shiba, Kazuhiro; Mori, Hirofumi

1990-10-01

A fundamental study was performed on the nuclear medicine imaging of cholinergic innervation in the brain. In a cholinergic denervation model prepared by producing an unilateral basal forebrain lesion in the rat, which is reported to be one of animal models of Alzheimer' disease, quantitative determination of acetylcholine in parietal cortices revealed statistically significant 31% decrease on an average in the ipsilateral side relative to the contralateral side to the lesion. In vitro receptor autoradiography showed no significant differences in total, M{sub 1}, and M{sub 2} muscarinic acetylcholine receptors between the ipsilateral and contralateral cortices to the lesion. Simultaneous mapping of presynaptic cholinergic innervation using {sup 3}H-2-(4-phenylpiperidino) cyclohexanol (AH5183) demonstrated significant 14% decrease of AH5183 binding on an average in the ipsilateral relative to the contralateral fronto-parieto-temporal cortices to the lesion. These results suggest that AH5183 is a promising ligand for mapping cholinergic innervation in nuclear medicine imaging. (author).

Effect of plasma actuator and splitter plate on drag coefficient of a circular cylinder

Science.gov (United States)

Akbıyık, Hürrem; Erkan Akansu, Yahya; Yavuz, Hakan; Ertuğrul Bay, Ahmet

2016-03-01

In this paper, an experimental study on flow control around a circular cylinder with splitter plate and plasma actuator is investigated. The study is performed in wind tunnel for Reynolds numbers at 4000 and 8000. The wake region of circular cylinder with a splitter plate is analyzed at different angles between 0 and 180 degrees. In this the study, not only plasma actuators are activated but also splitter plate is placed behind the cylinder. A couple electrodes are mounted on circular cylinder at ±90 degrees. Also, flow visualization is achieved by using smoke wire method. Drag coefficient of the circular cylinder with splitter plate and the plasma actuator are obtained for different angles and compared with the plain circular cylinder. While attack angle is 0 degree, drag coefficient is decreased about 20% by using the splitter plate behind the circular cylinder. However, when the plasma actuators are activated, the improvement of the drag reduction is measured to be 50%.

Shear-induced autorotation of freely rotatable cylinder in a channel flow at moderate Reynolds number

Science.gov (United States)

Xia, Yi; Lin, Jianzhong; Ku, Xiaoke; Chan, Tatleung

2018-04-01

Flow past a center-pinned freely rotatable cylinder asymmetrically confined in a two-dimensional channel is simulated with the lattice Boltzmann method for a range of Reynolds number 0.1 ≤ Re ≤ 200, eccentricity ratio 0/8 ≤ ɛ ≤ 7/8, and blockage ratio 0.1 ≤ β ≤ 0.5. It is found that the inertia tends to facilitate the anomalous clockwise rotation of the cylinder. As the eccentricity ratio increases, the cylinder rotates faster in the counterclockwise direction and then slows down at a range of Re 40, there exists an anomalous clockwise rotation for the cylinder at a low eccentricity ratio and the domain where the cylinder rotates anomalously becomes larger with the increase in the Reynolds number. In a channel with a higher blockage ratio, the rotation of the cylinder is more sensitive to the change of cylinder lateral position, and the separatrix at which the cylinder remains a state of rest moves upward generally. The cylinder is more likely to rotate counterclockwise and the rotating velocity is larger. At a lower blockage ratio, the anomalous clockwise rotation is more likely to occur, and the largest rotating velocity occurs when the blockage ratio is equal to 0.3. The mechanism of distinct rotational behavior of the cylinder is attributed to the transformation of distribution of shear stress which is resulted from the variation of pressure drop, the shift of maximum or minimum pressure zones along the upper and lower semi-cylinder surface, and the movement of stagnant point and separate point. Finally, the effects of the cylinder rotation on the flow structure and hydrodynamic force exerted on the cylinder surface are analyzed as well.

Online Condition Monitoring of Gripper Cylinder in TBM Based on EMD Method

Science.gov (United States)

Li, Lin; Tao, Jian-Feng; Yu, Hai-Dong; Huang, Yi-Xiang; Liu, Cheng-Liang

2017-11-01

The gripper cylinder that provides braced force for Tunnel Boring Machine (TBM) might fail due to severe vibration when the TBM excavates in the tunnel. Early fault diagnosis of the gripper cylinder is important for the safety and efficiency of the whole tunneling project. In this paper, an online condition monitoring system based on the Empirical Mode Decomposition (EMD) method is established for fault diagnosis of the gripper cylinder while TBM is working. Firstly, the lumped mass parameter model of the gripper cylinder is established considering the influence of the variable stiffness at the rock interface, the equivalent stiffness of the oil, the seals, and the copper guide sleeve. The dynamic performance of the gripper cylinder is investigated to provide basis for its health condition evaluation. Then, the EMD method is applied to identify the characteristic frequencies of the gripper cylinder for fault diagnosis and a field test is used to verify the accuracy of the EMD method for detection of the characteristic frequencies. Furthermore, the contact stiffness at the interface between the barrel and the rod is calculated with Hertz theory and the relationship between the natural frequency and the stiffness varying with the health condition of the cylinder is simulated based on the dynamic model. The simulation shows that the characteristic frequencies decrease with the increasing clearance between the barrel and the rod, thus the defects could be indicated by monitoring the natural frequency. Finally, a health condition management system of the gripper cylinder based on the vibration signal and the EMD method is established, which could ensure the safety of TBM.

Force Control for a Pneumatic Cylinder Using Generalized Predictive Controller Approach

OpenAIRE

Mohd Faudzi, Ahmad ’Athif; Mustafa, Nu’man Din; Osman, Khairuddin

2014-01-01

Pneumatic cylinder is a well-known device because of its high power to weight ratio, easy use, and environmental safety. Pneumatic cylinder uses air as its power source and converts it to a possible movement such as linear and rotary movement. In order to control the pneumatic cylinder, controller algorithm is needed to control the on-off solenoid valve with encoder and pressure sensor as the feedback inputs. In this paper, generalized predictive controller (GPC) is proposed as the control st...

Mechanism of drag reduction for circular cylinders with patterned surface

International Nuclear Information System (INIS)

Butt, U.; Jehring, L.; Egbers, C.

2014-01-01

Highlights: • Reduced drag of patterned cylinders over a wide range of Re numbers. • Hexagonal patterns cannot be characterized as roughness structures. • Hexagonal bumps affect the flow like spherical dimples of smaller k/d ratio do. • Main separation is delayed caused by a partial separation. • Angle of a separation line is not constant over the length of cylinder. -- Abstract: In this paper, the flow over cylinders with a patterned surface (k/d = 1.98 × 10 −2 ) is investigated in a subsonic wind tunnel over Reynolds numbers ranging from 3.14 × 10 4 to 2.77 × 10 5 by measuring drag, flow visualization and measuring velocity profiles above the surface of the cylinders, to observe the effect of hexagonal patterns on the flow of air. These patterns can also be referred as hexagonal dimples or bumps depending on their configuration. The investigations revealed that a patterned cylinder with patterns pressed outwards has a drag coefficient of about 0.65 times of a smooth one. Flow visualization techniques including surface oil-film technique and velocity profile measurement were employed to elucidate this effect, and hence present the mechanism of drag reduction. The measurement of velocity profiles using hot-wire anemometry above the surface reveal that a hexagonal bump cause local separation generating large turbulence intensity along the separating shear layer. Due to this increased turbulence, the flow reattaches to the surface with higher momentum and become able to withstand the pressure gradient delaying the main separation significantly. Besides that, the separation does not appear to occur in a straight line along the length of the cylinder as in case of most passive drag control methods, but follow exactly the hexagonal patterns forming a wave with its crest at 115° and trough at 110°, in contrast to the laminar separation line at 85° for a smooth cylinder

Experimental research of the yielding behavior of a graphite cylinder subjected to line loading

International Nuclear Information System (INIS)

Liu Hetong; Ma Qinwei; Ma Shaopeng; Wang Hongtao

2014-01-01

The graphite material cylinders are widely used in High-temperature gas-cooled reactor as connecting components. For engineering design, the deformation behavior, especially the yielding process of the graphite cylinder should be investigated in order to evaluate the carrying capacity of the cylinder. The yielding formation and propagation of a graphite cylinder subjected to line loading, which corresponds to the global behavior of the structure, was experimentally studied and evaluated by measuring the strain fields on the end of the cylinder using Digital Image Correlation. The global behavior of the structure is expressed by a relationship between the average stress (load divided by contact area) and the equivalent strain (ratio of half width of contact area to radius of the cylinder), the contact area was measured by identifying the color area of the pressure film in a new experiment which graphite component is loaded and unloaded continuously. A correspondence between the yielding state and the nonlinearity of the global behavior was constructed, as loading was increased, the cylinder was found to first yield at a specific point after which a yielding core formed and propagated. Before the yielding core propagated to the surface of the cylinder, the global behavior of the structure remained linear. After the yielding core propagated to the surface of the cylinder, the global behavior became nonlinear. The correspondence constructed in the paper will be helpful to understand the failure process and to evaluate the carrying capacity of a graphite cylinder subjected to line loading in reactors. (author)

Experimental Study on Natural Convection Heat Transfer From two Parallel Horizontal Cylinders in Horizontal Cylindrical Enclosure

Directory of Open Access Journals (Sweden)

Ahmed T. Ahmed

2013-05-01

Full Text Available  An experimental study on natural convection heat transfer from two parallel horizontal cylinders in horizontal cylindrical enclosure was carried out under condition of constant surfaces temperature for two cylinders and cylindrical enclosure. The study included the effect of Rayleigh number, rotation angle that represent the confined angle between the passing horizontal plane in cylindrical enclosure center and passing line in two cylinders centers, and the spaces between two cylinders on their heat loss ability.39An experimental set-up was used for this purpose which consist watercontainer, test section which is formed of plastic cylinder that represent the cylindrical enclosure, and two heating elements which are formed of two copper cylinders with (19 mm in diameters heated internally by electrical sources that represents transfer and heat loss elements through this set-up.      The experiments were done at the range of Rayleigh number between ( , cylinders rotation angle at ( , and spacing ratio at ( .     The study showed that the ability of heat loss from two cylinders is a function of Rayleigh number, cylinders rotation angle, and the spaces between them. This ability is increased by increasing of Rayleigh number and it was showed that this ability reaches maximum value at the first cylinder ( and minimum value at the second cylinder ( at spacing ratio (S/D=3 and rotation angle ( for the first and ( for the second cylinder respectively.      The effective variables on natural convection heat transfer from the above two cylinders are related by two correlating equations, each one explains dimensionless relation of heat transfer from each cylinder that represented by Nusselt number against Rayleigh number, rotation angle, and the spacing ratio between two cylinders. 

Heat convection in a set of three vertical cylinders

International Nuclear Information System (INIS)

Serrano Ramirez, M.L. de.

1993-01-01

Experimental results on temperature and heat flow in a set of three vertical cylinders with internal generation of heat, water submerged and in free convection are presented in this work . Temperature distribution, Nusselt number and convective coefficient (h) for each rod, developed for the distance between the axis of cylinders in vertical position, as a consequence of the application of power in its outside, are analyzed. Experimental information about heat transfer by free convection in vertical cylinders and surfaces is analyzed. Information of the several author who have carried out studies about the heat transfer on vertical cylinders was compiled, and the proposed equations with the experimental data obtained in the thermo fluids laboratory of National Institute of Nuclear Research (ININ) were tested. The way in which separation distance, s, distribution temperature array, Nusselt number, and convective coefficient calculated for the proposed channel with the Keyhani, Dutton and experimental equations are tabulated and they are plotted for each power value and for each separation between rods. The scheme of the used equipment and the experimentation description as well as the observations of tests and graphical results are included. (Author)

Development of free surface flow between concentric cylinders with vertical axes

International Nuclear Information System (INIS)

Watanabe, T; Toya, Y; Nakamura, I

2005-01-01

Numerical and experimental studies are conducted on flows developing between two concentric cylinders with vertical axes. The inner cylinder rotates and the outer and the lower end wall are fixed. The upper boundary is a free surface. The flow is at rest in an initial state, and the inner cylinder impulsively begins to rotate or its rotation speed linearly increases to a prescribed value. The acceleration rate of the inner cylinder changes the formation processes of flows and/or the final flow modes. Time-dependent flows appear at higher Reynolds numbers, and the numerical and experimental results of the power spectra show some agreements. It is suggested that critical Reynolds numbers appear, at which the fluctuations in the displacement of the free surface and the kinetic energy of a velocity component steeply increase

Disk-cylinder method for using NMR to measure magnetic susceptibility

International Nuclear Information System (INIS)

Burnham, A.K.

1978-01-01

The sphere-cylinder method of using nuclear magnetic resonance (NMR) to measure the magnetic susceptibility of diamagnetic and paramagnetic materials has been generalized to the disk-cylinder method. A two-fold increase in sensitivity was obtained. Accuracies of 0.1% of the diamagnetism of water should be readily obtainable

High Reynolds number oscillations of a circular cylinder

OpenAIRE

Hirata, Miguel H.; Pereira, Luiz Antonio A.; Recicar, Jan N.; Moura, Washington H. de

2008-01-01

This paper concerns the numerical simulation of the flow around an oscillating circular cylinder, which moves with constant velocity in a quiescent Newtonian fluid with constant properties. For each time step of the simulation a number of discrete Lamb vortices is placed close to the body surface; the intensity of each of these is determined such as to satisfy the no-slip boundary condition. The aerodynamic loads acting on the surface of cylinder are computed using the integral formulation de...

Large eddy simulation of the subcritical flow over a V grooved circular cylinder

International Nuclear Information System (INIS)

Alonzo-García, A.; Gutiérrez-Torres, C. del C.; Jiménez-Bernal, J.A.

2015-01-01

Highlights: • We compared numerically the turbulent flow over a smooth circular cylinder and a V grooved cylinder in the subcritical regime. • Turbulence intensities in both streamwise and normal direction suffered attenuations. • The swirls structures on grooves peaks seemed to have a cyclic behavior. • The evolution of the flow inside grooves showed that swirls structures located in peaks suffered elongations in the normal direction. • The secondary vortex structures formed in the grooved cylinder near wake were smaller in comparison of the smooth cylinder flow. - Abstract: In this paper, a comparative numerical study of the subcritical flow over a smooth cylinder and a cylinder with V grooves (Re = 140,000) is presented. The implemented technique was the Large Eddy Simulation (LES), which according to Kolmogorov's theory, resolves directly the most energetic largest eddies and models the smallest and considered universal high frequency ones. The Navier-Stokes (N-S) equations were solved using the commercial software ANSYS FLUENT V.12.1, which applied the finite volume method (FVM) to discretize these equations in their unsteady and incompressible forms. The grid densities were 2.6 million cells and 13.5 million cells for the smooth and V grooved cylinder, respectively. Both meshes were composed of structured hexahedral cells and close to the wall of the cylinders, additional refinements were employed in order to obtain y +<5 values. All cases were simulated during at least 15 vortex shedding cycles with the aim of obtaining significant statistical data. Results: showed that for both cases (smooth and V grooved cylinder flow), the numerical code was capable of reproducing the most important physical quantities of the subcritical regime. Velocity distribution and turbulence intensity in the flow direction suffered a slight attenuation along the wake, as a consequence of grooves perturbation, which also caused an increase in the pressure coefficient

Pulsatility role in cylinder flow dynamics at low Reynolds number

KAUST Repository

Qamar, Adnan

2012-01-01

We present dynamics of pulsatile flow past a stationary cylinder characterized by three non-dimensional parameters: the Reynolds number (Re), non-dimensional amplitude (A) of the pulsatile flow velocity, and Keulegan-Carpenter number (KC = Uo/Dωc). This work is motivated by the development of total artificial lungs (TAL) device, which is envisioned to provide ambulatory support to patients. Results are presented for 0.2 ≤ A ≤ 0.6 and 0.57 ≤ KC ≤ 2 at Re = 5 and 10, which correspond to the operating range of TAL. Two distinct fluid regimes are identified. In both regimes, the size of the separated zone is much greater than the uniform flow case, the onset of separation is function of KC, and the separation vortex collapses rapidly during the last fraction of the pulsatile cycle. The vortex size is independent of KC, but with an exponential dependency on A. In regime I, the separation point remains attached to the cylinder surface. In regime II, the separation point migrates upstream of the cylinder. Two distinct vortex collapse mechanisms are observed. For A < 0.4 and all KC and Re values, collapse occurs on the cylinder surface, whereas for A > 0.4 the separation vortex detaches from the cylinder surface and collapses at a certain distance downstream of the cylinder. The average drag coefficient is found to be independent of A and KC, and depends only on Re. However, for A > 0.4, for a fraction of the pulsatile cycle, the instantaneous drag coefficient is negative indicating a thrust production. © 2012 American Institute of Physics.

Longitudinal Weld Land Buckling in Compression-Loaded Orthogrid Cylinders

Science.gov (United States)

Thornburgh, Robert P.; Hilburger, Mark W.

2010-01-01

Large stiffened cylinders used in launch vehicles (LV), such as the Space Shuttle External Tank, are manufactured by welding multiple curved panel sections into complete cylinders. The effects of the axial weld lands between the panel sections on the buckling load were studied, along with the interaction between the acreage stiffener arrangement and the weld land geometry. This document contains the results of the studies.

Mixed convection of ferrofluids in a lid driven cavity with two rotating cylinders

Directory of Open Access Journals (Sweden)

Fatih Selimefendigil

2015-09-01

Full Text Available Mixed convection of ferrofluid filled lid driven cavity in the presence of two rotating cylinders were numerically investigated by using the finite element method. The cavity is heated from below, cooled from driven wall and rotating cylinder surfaces and side vertical walls of the cavity are assumed to be adiabatic. A magnetic dipole source is placed below the bottom wall of the cavity. The study is performed for various values of Reynolds numbers (100 ≤ Re ≤ 1000, angular rotational speed of the cylinders (−400 ≤ Ω ≤ 400, magnetic dipole strengths (0 ≤ γ ≤ 500, angular velocity ratios of the cylinders (0.25≤Ωi/Ωj≤4 and diameter ratios of the cylinders (0.5≤Di/Dj≤2. It is observed that flow patterns and thermal transport within the cavity are affected by variation in Reynolds number and magnetic dipole strength. The results of this investigation revealed that cylinder angular velocities, ratio of the angular velocities and diameter ratios have profound effect on heat transfer enhancement within the cavity. Averaged heat transfer enhancements of 181.5 % is achieved for clockwise rotation of the cylinder at Ω = −400 compared to motionless cylinder case. Increasing the angular velocity ratio from Ω2/Ω1=0.25 to Ω2/Ω1=4 brings about 91.7 % of heat transfer enhancement.

"Fast" and "slow" skeleto-fusimotor innervation in cat tenuissimus spindles; a study with the glycogen-depletion method.

Science.gov (United States)

Jami, L; Lan-Couton, D; Malmgren, K; Petit, J

1978-07-01

The glycogen-depletion method was used to investigate the motor supply to tenuissimus with respect to the presence of fast beta axons and to assess the total proportion of both fast and slow beta-innervated spindles in this muscle. In a first series of 5 expts., groups of motor axons with conduction velocities higher than 85 m/s were repetitively stimulated so as to produce glycogen depletion in the muscle fibres they innervated. The whole muscle was then quick-frozen, serially cut, stained to demonstrate glycogen and examined for intrafusal glycogen depletion. Zones of glycogen depletion were found in 16 of the 46 examined spindles; they were most frequently located in the longest of the chain intrafusal muscle fibres. Since it is known that there are no purely fusimotor axons to tenuissimus with conduction velocities above 50 m/s, it was concluded that beta axons are present among the fastest axons to this muscle. In a second series of 5 expts. as many motor axons as possible with conduction velocities above 60 m/s were stimulated. Zones of glycogen depletion were found in 19 of the 47 examined spindles. They affected chain fibres in about half of the instances and bag1 fibers in the others. As this latter location is characteristic of slow dynamic beta axons, it was concluded that both slow and fast beta axons occur regularly in the motor supply to tenuissimus. beta-innervation is present in at least 40% of tenuissimus spindles with almost no convergence of fast and slow beta axons onto the same spindle.

Developmental neurotoxicity targeting hepatic and cardiac sympathetic innervation: effects of organophosphates are distinct from those of glucocorticoids.

Science.gov (United States)

Seidler, Frederic J; Slotkin, Theodore A

2011-05-30

Early-life exposure to organophosphate pesticides leads to subsequent hyperresponsiveness of β-adrenergic receptor-mediated cell signaling that regulates hepatic gluconeogenesis, culminating in metabolic abnormalities resembling prediabetes. In the current study, we evaluated the effects of chlorpyrifos or parathion on presynaptic sympathetic innervation to determine whether the postsynaptic signaling effects are accompanied by defects in neuronal input. We administered either chlorpyrifos or parathion to newborn rats using exposure paradigms known to elicit the later metabolic changes but found no alterations in either hepatic or cardiac norepinephrine levels in adolescence or adulthood. However, shifting chlorpyrifos exposure to the prenatal period did evoke changes: exposure early in gestation produced subsequent elevations in norepinephrine, whereas later gestational exposure produced significant deficits. We also distinguished the organophosphate effects from those of the glucocorticoid, dexamethasone, a known endocrine disruptor that leads to later-life metabolic and cardiovascular disruption. Postnatal exposure to dexamethasone elicited deficits in peripheral norepinephrine levels but prenatal exposure did not. Our results indicate that early-life exposure to organophosphates leads to subsequent abnormalities of peripheral sympathetic innervation through mechanisms entirely distinct from those of glucocorticoids, ruling out the possibility that the organophosphate effects are secondary to stress or disruption of the HPA axis. Further, the effects on innervation were separable from those on postsynaptic signaling, differing in critical period as well as tissue- and sex-selectivity. Organophosphate targeting of both presynaptic and postsynaptic β-adrenergic sites, each with different critical periods of vulnerability, thus sets the stage for compounding of hepatic and cardiac functional abnormalities. Copyright © 2011 Elsevier Inc. All rights reserved.

Effect of slip on vortex dynamics and forcing of a superhydrophobic cylinder

Science.gov (United States)

Muralidhar, Pranesh; Daniello, Robert; Ferrer, Nangelie; Rothstein, Jonathan

2011-11-01

Superhydrophobic surfaces have been shown to produce significant drag reduction for both laminar and turbulent flows of water through large and small-scale channels. In this presentation, a series of experiments will be presented which investigate the effect of superhydrophobic-induced slip on the vortex dynamics in the wake of a cylinder and the change in the drag and lift forces thereof. In these experiments, circular cylinders are coated with a series of superhydrophobic surfaces fabricated from PDMS with well-defined micron-sized patterns of surface roughness. Using force measurements and PIV (Particle Image Velocimetry), we will show that these surfaces have a noticeable effect on the drag/lift and vortex dynamics of cylinders. When compared to a smooth, no-slip cylinder, we will show that the lift/drag and the amount of raw vorticity that is shed in the wake of the superhydrophobic cylinder decreases. In addition, we will show that the forcing is sensitive to changes of feature spacing, size and orientation.

Research on torsional vibration modelling and control of printing cylinder based on particle swarm optimization

Science.gov (United States)

Wang, Y. M.; Xu, W. C.; Wu, S. Q.; Chai, C. W.; Liu, X.; Wang, S. H.

2018-03-01

The torsional oscillation is the dominant vibration form for the impression cylinder of printing machine (printing cylinder for short), directly restricting the printing speed up and reducing the quality of the prints. In order to reduce torsional vibration, the active control method for the printing cylinder is obtained. Taking the excitation force and moment from the cylinder gap and gripper teeth open & closing cam mechanism as variable parameters, authors establish the dynamic mathematical model of torsional vibration for the printing cylinder. The torsional active control method is based on Particle Swarm Optimization(PSO) algorithm to optimize input parameters for the serve motor. Furthermore, the input torque of the printing cylinder is optimized, and then compared with the numerical simulation results. The conclusions are that torsional vibration active control based on PSO is an availability method to the torsional vibration of printing cylinder.

Transient Simulation of a Rotating Conducting Cylinder in a Transverse Magnetic Field

Science.gov (United States)

2016-09-01

the boundary conditions and magnetic field excitation. The balloon (no fringing at infinity ) boundary condition is used for the model. Two magnetic...cylinder to study the effects of the magnetic responses of the cylinder in the time history . Table 1 summarizes the electromagnetic properties of the...and phase shift angles of the magnetic flux density in the time history , at the center of the structural steel, aluminum, and copper cylinder

Dynamic Penile Corpora Cavernosa Reconstruction Using Bilateral Innervated Gracilis Muscles: A Preclinical Investigation.

Science.gov (United States)

Yin, Zhuming; Liu, Liqiang; Xue, Bingjian; Fan, Jincai; Chen, Wenlin; Liu, Zheng

2018-03-07

Prosthesis-assisted penile reconstruction has been performed extensively to restore a cosmetically acceptable phallus. However, a large number of patients will undergo revision surgery for various prosthesis-related complications. To develop a 1-stage prosthesis-free dynamic cavernosa reconstruction method using bilateral innervated gracilis muscles and to investigate the feasibility and reliability of the surgical design. 10 fresh cadavers were dissected to assess the availability of bilateral gracilis muscles for functional cavernosa rebuilding. 11 mongrel female dogs were involved in the penile reconstruction surgery. The neophallus consisted of bilateral gracilis muscles as the neo-cavernosa, a right gracilis skin flap as the neourethra, and a lower abdominal flap with an anterior rectus sheath as the skin envelope and neo-tunica albuginea. The function and structure of the neo-phalli were assessed 7 months postoperatively. The neurovascular pedicle length of the gracilis muscles and the volume of the gracilis venter musculi were measured in the cadaveric investigation. The average dimensions of the canine neo-phalli at rest and during electrostimulated erection were obtained and the muscular fatigue-resistant curve was drawn. Histologic evaluations also were performed. The neurovascular pedicle length and volume of the gracilis muscles were sufficient to yield a nearly normal appearance of the neo-cavernosa in the cadaveric and animal studies. The muscular fatigue-resistant curve demonstrated adequate length, stiffness, and duration of erection of the neo-phalli to accomplish normal coitus. Histologic evaluations showed an intact neourethra and nearly normal muscle structure in the inner layer of the canine neo-cavernosa, except for significantly increased amount of collagen fibers and type I/III collagen ratio in the outer layer of the neo-cavernosa. The percentage of type II (fatigue-prone) muscle fibers did not change significantly. Our preclinical

On the motion of a compressible fluid in a rotating cylinder

International Nuclear Information System (INIS)

Brouwers, J.J.H.

1976-06-01

The secondary flow of an incompressible fluid or a perfect gas in a rotating cylinder is taken as a small perturbation on the isothermal state of rigid body rotation. Three types of flow are identified by increasing length-to-radius ratio L. These correspond to Esup(1/2) -1 and E -1 approximately L, where E is the Ekman number based on the radius and taken to be small. In the first range a geostrophic flow in the interior extended by Ekman layers near the end caps and Stewartson layers near the cylinder wall is found. For L approximately Esup(-1/2) and L approximately E -1 both Stewartson layers successively expand to the interior. For L approximately> E -1 radial diffusion of momentum is an important parameter describing the flow in the main section of the cylinder. For the perfect gas, special attention is focussed on strong radial density gradients. The modified Ekman number Esub(m) based on the density at the cylinder wall and on the density scale height is taken to be small. Increasing the ratio of the length to the radial density scale height Lsub(m) again three types of flow are distinguished. These correspond to Esub(m)sup(1/2) -1 and Esub(m)sup(-1) approximately Lsub(m). Compared to the incompressible fluid, two essential differences are found. (i) An inviscid flow characteristic for the first range is only observed in a limited region near the cylinder wall. Diffusive processes are important in the core of the cylinder. (ii) A change of the flow type appears when both Stewartson layers successively expand over the small radial density scale height. Diffusive regions come up from the centre of the cylinder and join. A change of the flow type appears at relatively small values of L. The theory discusses the efficiency of gas ultracentrifuges for isotope separation

Mass transfer behavior of rotating square cylinder electrochemical reactor in relation to wastewater treatment

International Nuclear Information System (INIS)

Abdel-Aziz, M.S.M.; El-Shazly, A.H.; Farag, H.A.; Sedahmed, G.H.

2011-01-01

Highlights: → The work explores a new electrochemical reactor by using square rotating cylinders. → The results show that it is superior to the traditional circular rotating cylinder. → A dimensionless design equation for the new reactor was correlated. → The oxalic acid removal by the new reactor was succeeded and found promising. → The energy consumption per kg oxalic acid removed by the unit was calculated. - Abstract: Rates of mass transfer at a rotating square cylinder were measured by an electrochemical technique which involved measuring the limiting current of the cathodic reduction of K 3 Fe(CN) 6 in a large excess of NaOH solution. Variables studied were: cylinder rotation speed, physical properties of the solution and cylinder equivalent diameter. The data for the condition 1577 0.33 Re 0.45 For a given set of conditions the rate of mass transfer at the square rotating cylinder was found to be higher than that at the traditional circular rotating cylinder by an amount ranging from 47% to 200% depending on Re. The use of the square rotating cylinder electrode in removing oxalic acid from wastewater by anodic oxidation on Pb/PbO anode was examined and found to be promising.

Reduction of sound transmission across plenum windows by incorporating an array of rigid cylinders

Science.gov (United States)

Tang, S. K.

2018-02-01

The potential improvement of plenum window noise reduction by installing rigid circular cylinder arrays into the window cavity is investigated numerically using the finite-element method in this study. A two-dimensional approach is adopted. The sound transmission characteristics and propagation within the plenum window are also examined in detail. Results show that the installation of the cylinders in general gives rise to broadband improvement of noise reduction across a plenum window regardless of the direction of sound incidence. Such acoustical performance becomes better when more cylinder columns are installed, but it is suggested that the number of cylinder rows should not exceed two. Results also show that the cylinder positions relative to the nodal/anti-nodal planes of the acoustic modes are crucial in the noise reduction enhancement mechanisms. Noise reduction can further be enhanced by staggering the cylinder rows, such that each cylinder row supports the development of a different acoustic mode. For the simple cylinder arrangements considered in this study, the traffic noise reduction enhancement observed in this study can be as high as 4-5 dB, which is already comparable to or higher than the maximum achieved by installing sound absorption into a plenum window.

Energy Loss, Velocity Distribution, and Temperature Distribution for a Baffled Cylinder Model, Special Report

Science.gov (United States)

Brevoort, Maurice J.

1937-01-01

In the design of a cowling a certain pressure drop across the cylinders of a radial air-cooled engine is made available. Baffles are designed to make use of this available pressure drop for cooling. The problem of cooling an air-cooled engine cylinder has been treated, for the most part, from considerations of a large heat-transfer coefficient. The knowledge of the precise cylinder characteristics that give a maximum heat-transfer coefficient should be the first consideration. The next problem is to distribute this ability to cool so that the cylinder cools uniformly. This report takes up the problem of the design of a baffle for a model cylinder. A study has been made of the important principles involved in the operation of a baffle for an engine cylinder and shows that the cooling can be improved 20% by using a correctly designed baffle. Such a gain is as effective in cooling the cylinder with the improved baffle as a 65% increase in pressure drop across the standard baffle and fin tips.

Analysis of composite hydrogen storage cylinders subjected to localized flame impingements

Energy Technology Data Exchange (ETDEWEB)

Hu, J.; Chen, J.; Sundararaman, S.; Chandrashekhara, K. [Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Chernicoff, William [US Department of Transportation, Washington, DC 20509 (United States)

2008-06-15

A comprehensive non-linear finite element model is developed for predicting the behavior of composite hydrogen storage cylinders subjected to high pressure and localized flame impingements. The model is formulated in an axi-symmetric coordinate system and incorporates with various sub-models to describe the behavior of the composite cylinder under extreme thermo-mechanical loadings. A heat transfer sub-model is employed to predict the temperature evolution of the composite cylinder wall and accounts for heat transport due to decomposition and mass loss. A composite decomposition sub-model described by Arrhenius's law is implemented to predict the residual resin content of thermal damaged area. A sub-model for material degradation is implemented to account for the loss of mechanical properties. A progressive failure model is adopted to detect various types of mechanical failure. These sub-models are implemented in ABAQUS commercial finite element code using user subroutines. Numerical results are presented for thermal damage, residual properties and profile of resin content in the cylinder. The developed model provides a useful tool for safe design and structural assessment of high pressure composite hydrogen storage cylinders. (author)

Failure Analysis of a Modern High Performance Diesel Engine Cylinder Head

Directory of Open Access Journals (Sweden)

Bingbin Guo

2014-05-01

Full Text Available This paper presents a failure analysis on a modern high performance diesel engine cylinder head made of gray cast iron. Cracks appeared intensively at the intersection of two exhaust passages in the cylinder head. The metallurgical examination was conducted in the crack origin zone and other zones. Meanwhile, the load state of the failure part of the cylinder head was determined through the Finite Element Analysis. The results showed that both the point of the maximum temperature and the point of the maximum thermal-mechanical coupling stress were not in the crack position. The excessive load was not the main cause of the failure. The large cooling rate in the casting process created an abnormal graphite zone that existed below the surface of the exhaust passage (about 1.1 mm depth, which led to the fracture of the cylinder head. In the fractured area, there were a large number of casting defects (dip sand, voids, etc. and inferior graphite structure (type D, type E which caused stress concentration. Moreover, high temperature gas entered the cracks, which caused material corrosion, material oxidization, and crack propagation. Finally, premature fracture of the cylinder head took place.

Buckling Response of a Large-Scale, Seamless, Orthogrid-Stiffened Metallic Cylinder

Science.gov (United States)

Rudd, Michelle Tillotson; Hilburger, Mark W.; Lovejoy, Andrew E.; Lindell, Michael C.; Gardner, Nathaniel W.; Schultz, Marc R.

2018-01-01

Results from the buckling test of a compression-loaded 8-ft-diameter seamless (i.e., without manufacturing joints), orthogrid-stiffened metallic cylinder are presented. This test was used to assess the buckling response and imperfection sensitivity characteristics of a seamless cylinder. In addition, the test article and test served as a technology demonstration to show the application of the flow forming manufacturing process to build more efficient buckling-critical structures by eliminating the welded joints that are traditionally used in the manufacturing of large metallic barrels. Pretest predictions of the cylinder buckling response were obtained using a finite-element model that included measured geometric imperfections. The buckling load predicted using this model was 697,000 lb, and the test article buckled at 743,000 lb (6% higher). After the test, the model was revised to account for measured variations in skin and stiffener geometry, nonuniform loading, and material properties. The revised model predicted a buckling load of 754,000 lb, which is within 1.5% of the tested buckling load. In addition, it was determined that the load carrying capability of the seamless cylinder is approximately 28% greater than a corresponding cylinder with welded joints.

A study on the design of a low-friction, high-speed pneumatic cylinder

International Nuclear Information System (INIS)

Kim, Do Tae; Kim, Dong Soo; Ju, Min Jin

2008-01-01

Of all of pneumatic components utilized in the make up of pneumatic circuits on either automatic assembly machine or industrial equipment, the pneumatic cylinder is more oriented toward being a structural as well as a pneumatic member. The structural design must be based to a large degree on the end of application of the cylinder on the equipment it is operating. In this paper, design studies of a double-acting pneumatic cushion type cylinder with low-friction and high-speed driving have been developed. Of interest here is to investigate the structural analysis of cylinder tube, piston rod, end cover, and to analyze the buckling of piston rod. Also, a relief valve type cushion mechanism is considered. This cushion mechanism is found to be adequate under a high-speed driving of pneumatic cylinders

Experimental vibration study of in-air and fluid coupled co-axial cylinders

International Nuclear Information System (INIS)

Chu, M.; Brown, S.; Lestingi, J.

1979-01-01

It was the objective of this study to develop and carry out an experimental program which would provide additional insight into the mechanics of fluid--solid interaction with respect to the response of a set of coaxial cylinders with water in the annulus. Such configurations are found in nuclear reactors in the vessel wall-thermal liner. The effects of cylinder thickness and the fluid filled annulus gap size on the resonant frequencies and mode shapes of the cylinders (either singly or coupled in air and a water environment) are presented in this paper; also included is an evaluation of damping for selected gaps and cylinder thicknesses. Details of the experimental setup and procedures are also outlined

Elastic torsional buckling of thin-walled composite cylinders

Science.gov (United States)

Marlowe, D. E.; Sushinsky, G. F.; Dexter, H. B.

1974-01-01

The elastic torsional buckling strength has been determined experimentally for thin-walled cylinders fabricated with glass/epoxy, boron/epoxy, and graphite/epoxy composite materials and composite-reinforced aluminum and titanium. Cylinders have been tested with several unidirectional-ply orientations and several cross-ply layups. Specimens were designed with diameter-to-thickness ratios of approximately 150 and 300 and in two lengths of 10 in. and 20 in. The results of these tests were compared with the buckling strengths predicted by the torsional buckling analysis of Chao.

Transverse magnetic scattering by parallel conducting elliptic cylinders

Science.gov (United States)

Sebak, A.

1991-10-01

A boundary value solution to the problem of transverse magnetic multiple scattering by M parallel perfectly conducting elliptic cylinders is presented. The solution is an exact one and based on the separation-of-variables technique and the addition theorem for Mathieu functions. It is expressed in terms of a system of simultaneous linear equations of infinite order, which is then truncated for numerical computations. Representative numerical results for the scattered field by two cylinders are then generated, for some selected sizes and orientations parameters, and presented.

Methods and results for stress analyses on 14-ton, thin-wall depleted UF6 cylinders

International Nuclear Information System (INIS)

Kirkpatrick, J.R.; Chung, C.K.; Frazier, J.L.; Kelley, D.K.

1996-10-01

Uranium enrichment operations at the three US gaseous diffusion plants produce depleted uranium hexafluoride (DUF 6 ) as a residential product. At the present time, the inventory of DUF 6 in this country is more than half a million tons. The inventory of DUF 6 is contained in metal storage cylinders, most of which are located at the gaseous diffusion plants. The principal objective of the project is to ensure the integrity of the cylinders to prevent causing an environmental hazard by releasing the contents of the cylinders into the atmosphere. Another objective is to maintain the cylinders in such a manner that the DUF 6 may eventually be converted to a less hazardous material for final disposition. An important task in the DUF 6 cylinders management project is determining how much corrosion of the walls can be tolerated before the cylinders are in danger of being damaged during routine handling and shipping operations. Another task is determining how to handle cylinders that have already been damaged in a manner that will minimize the chance that a breach will occur or that the size of an existing breach will be significantly increased. A number of finite element stress analysis (FESA) calculations have been done to analyze the stresses for three conditions: (1) while the cylinder is being lifted, (2) when a cylinder is resting on two cylinders under it in the customary two-tier stacking array, and (3) when a cylinder is resting on tis chocks on the ground. Various documents describe some of the results and discuss some of the methods whereby they have been obtained. The objective of the present report is to document as many of the FESA cases done at Oak Ridge for 14-ton thin-wall cylinders as possible, giving results and a description of the calculations in some detail

Influence of the stacking sequence of layers on the mechanical behavior of polymeric composite cylinders

International Nuclear Information System (INIS)

Carvalho, Osni de

2006-01-01

This work evaluated experimentally the influence of the stacking sequence of layers symmetrical and asymmetrical on the mechanical behavior of polymeric composite cylinders. For so much, two open-ended cylinders groups were manufactured by filament winding process, which had different stacking sequence related to the laminate midplane, characterizing symmetrical and asymmetrical laminates. The composite cylinders were made with epoxy matrix and carbon fiber as reinforcement. For evaluation of the mechanical strength, the cylinders were tested hydrostatically, which consisted of internal pressurization in a hydrostatic device through the utilization of a fluid until the cylinders burst. Additionally, were compared the strains and failure modes between the cylinders groups. The utilization of a finite element program allowed to conclude that this tool, very used in design, does not get to identify tensions in the fiber direction in each composite layer, as well as interlaminar shear stress, that appears in the cylinders with asymmetrical stacking sequence. The tests results showed that the stacking sequence had influence in the mechanical behavior of the composite cylinders, favoring the symmetrical construction. (author)

Vortex interactions in a two side-by-side cylinder near-wake

International Nuclear Information System (INIS)

Wang, Z.J.; Zhou, Y.

2005-01-01

The flow behind two side-by-side circular cylinders is experimentally investigated based on laser-illuminated flow-visualization, particle image velocimetry and hot-wire measurements. The flow is classified as three regimes: single street (the cylinder center-to-center spacing T/d 2.0). Special attention is given to the regime of 1.2 2.0, the flow structure change from the anti-phase to in-phase mode starts with a phase shift between gap vortices. The dynamical role of gap bleeding between cylinders for L/d < 1.2 is also examined

Use of Directional Spectra for Detection of Engine Cylinder Power Fault

Directory of Open Access Journals (Sweden)

Chong-Won Lee

1997-01-01

Full Text Available A diagnostic method, which uses the two-sided directional power spectra of complex-valued engine vibration signals, is presented and tested with four-cylinder compression and spark ignition engines for the diagnosis of cylinder power faults. As spectral estimators, the maximum likelihood and FFT methods are compared, and the multi-layer neural network is employed for pattern recognition. Experimental results show that the success rate for identifying the misfired cylinder is much higher with the use of two-sided directional power spectra than conventional one-sided power spectra.

Application of Potential Theory to Steady Flow Past Two Cylinders in Tandem Arrangement

Directory of Open Access Journals (Sweden)

Yangyang Gao

2014-01-01

Full Text Available The wake flow patterns associated with flow past a cylinder and a cylinder-pair in tandem configuration are revisited, compared, and evaluated with respect to the streamline patterns generated based on potential flow theory and superposition of various potential flow elements. The wakes, which are vortex shedding in the lee of the cylinder(s, are reproduced by placing pairs of equal but opposite circulation elements in the potential flow field. The strength of the circulation elements determines the size of the vortices produced. The streamline patterns of flow past a pair of unequal cylinders in tandem configuration provide an indirect means to establish the threshold condition for the wake transition from that of a single bluff body to alternating reattachment behavior. This threshold condition is found to be a function of the diameter ratio, d/D (diameters d and D, d≤D , spacing ratio, L/D (centre-to-centre distance, L, to cylinder diameter, D, and equivalent incident flow speed, U. A unique functional relationship f (L/D, d/D, U of this threshold condition is established.

Modelling and numerical simulation of vortex induced vibrations of single cylinder or cylinder arrays

International Nuclear Information System (INIS)

Jus, Y.

2011-01-01

This research thesis fits into the frame of researches achieved in the nuclear field in order to optimize the predictive abilities of sizing models of nuclear plant components. It more precisely addresses the modelling of the action exerted by the flowing fluid and the induced feedback by the structure dynamics. The objective is herein to investigate the interaction between the turbulence at the wall vicinity and the effects of non-conservative and potentially destabilizing unsteady coupling. The peculiar case of a single cylinder in infinite environment, and submitted to a transverse flow, is studied statically and then dynamically. The influence of flow regimes on dynamic response is characterized, and the quantification of fluid-structure interaction energy is assessed. The author then addresses the case of an array of cylinders, and highlights the contribution of three-dimensional macro-simulations for the analysis of flow-induced structure vibrations in subcritical regime within a High Performance Calculation (HPC) framework, and the interest of a CFD/CSM (computational fluid dynamics/computational structure mechanics) coupling in the case of turbulent flows in an industrial environment

An Unattended Verification Station for UF6 Cylinders: Development Status

International Nuclear Information System (INIS)

Smith, E.; McDonald, B.; Miller, K.; Garner, J.; March-Leuba, J.; Poland, R.

2015-01-01

In recent years, the International Atomic Energy Agency (IAEA) has pursued innovative techniques and an integrated suite of safeguards measures to address the verification challenges posed by advanced centrifuge technologies and the growth in separative work unit capacity at modern centrifuge enrichment plants. These measures would include permanently installed, unattended instruments capable of performing the routine and repetitive measurements previously performed by inspectors. Among the unattended instruments currently being explored by the IAEA is an Unattended Cylinder Verification Stations (UCVS) that could provide independent verification of the declared relative enrichment, U-235 mass and total uranium mass of all declared cylinders moving through the plant, as well as the application and verification of a ''Non-destructive Assay Fingerprint'' to preserve verification knowledge on the contents of each cylinder throughout its life in the facility. As IAEA's vision for a UCVS has evolved, Pacific Northwest National Laboratory (PNNL) and Los Alamos National Laboratory have been developing and testing candidate non-destructive assay (NDA) methods for inclusion in a UCVS. Modeling and multiple field campaigns have indicated that these methods are capable of assaying relative cylinder enrichment with a precision comparable to or substantially better than today's high-resolution handheld devices, without the need for manual wall-thickness corrections. In addition, the methods interrogate the full volume of the cylinder, thereby offering the IAEA a new capability to assay the absolute U-235 mass in the cylinder, and much-improved sensitivity to substituted or removed material. Building on this prior work, and under the auspices of the United States Support Programme to the IAEA, a UCVS field prototype is being developed and tested. This paper provides an overview of: a) hardware and software design of the prototypes, b) preparation

TR-PIV measurement of the wake behind a grooved cylinder at low Reynolds number

Science.gov (United States)

Liu, Ying Zheng; Shi, Liu Liu; Yu, Jun

2011-04-01

A comparative study of the wakes behind cylinders with grooved and smooth surfaces was performed with a view to understand the wake characteristics associated with the adult Saguaro cacti. A low-speed recirculation water channel was established for the experiment; the Reynolds number, based on the free-stream velocity and cylinder diameter (D), was kept at ReD=1500. State-of-the-art time-resolved particle image velocimetry (TR-PIV) was employed to measure a total of 20 480 realizations of the wake field at a frame rate of 250 Hz, enabling a comprehensive view of the time- and phase-averaged wake pattern. In comparison to the wake behind the smooth cylinder, the length of the recirculation zone behind the grooved cylinder was extended by nearly 18.2%, yet the longitudinal velocity fluctuation intensity was considerably weakened. A global view of the peaked spectrum of the longitudinal velocity component revealed that the intermediate region for the grooved cylinder, which approximately corresponds to the transition region where the shear layer vortices interact, merge and shed before the formation of the Karman-like vortex street, was much wider than that for the smooth one. The unsteady events near St=0.3-0.4 were detected in the intermediate region behind the grooved cylinder, but no such events were found in the smooth cylinder system. Although the formation of the Karman-like vortex street was delayed by about 0.6D downstream for the grooved cylinder, no prominent difference in the vortex street region was found in the far wake for both cylinders. The Proper Orthogonal Decomposition (POD) method was used extensively to decompose the vector and swirling strength fields, which gave a close-up view of the vortices in the near wake. The first two POD modes of the swirling strength clarified the spatio-temporal characteristics of the shear layer vortices behind the grooved cylinder. The small-scale vortices superimposed on the shear layers behind the grooved cylinder

Directed Assembly of Janus Cylinders by Controlling the Solvent Polarity.

Science.gov (United States)

Kim, Jongmin; Choi, Chang-Hyung; Yeom, Su-Jin; Eom, Naye; Kang, Kyoung-Ku; Lee, Chang-Soo

2017-08-01

This study demonstrates the possibility of controlling the directed self-assembly of microsized Janus cylinders by changing the solvent polarity of the assembly media. Experimental results are analyzed and theoretical calculations of the free energy of adhesion (ΔG ad ) are performed to elucidate the underlying basic principles and investigate the effects of the solvent on the self-assembled structures. This approach will pave a predictive route for controlling the structures of assembly depending on the solvent polarity. In particular, we find that a binary solvent system with precisely controlled polarity induces directional assembly of the microsized Janus cylinders. Thus, the formation of two-dimensional (2D) and three-dimensional (3D) assembled clusters can be reliably tuned by controlling the numbers of constituent Janus cylinders in a binary solvent system. Finally, this approach is expanded to stepwise assembly, which forms unique microstructures via secondary growth of primary seed clusters formed by the Janus cylinders. We envision that this investigation is highly promising for the construction of desired superstructures using a wide variety of polymeric Janus microparticles with chemical and physical multicompartments.

Mathematical Modeling of Partial-Porous Circular Cylinders with Water Waves

Directory of Open Access Journals (Sweden)

Min-Su Park

2015-01-01

Full Text Available The interaction of water waves with partially porous-surfaced circular cylinders was investigated. A three-dimensional numerical modeling was developed based on the complete mathematical formulation of the eigenfunction expansion method in the potential flow. Darcy’s law was applied to describe the porous boundary. The partial-porous cylinder is composed of a porous-surfaced body near the free surface, and an impermeable-surfaced body with an end-capped rigid bottom below the porous region. The optimal ratio of the porous portion to the impermeable portion can be adopted to design an effective ocean structure with minimal hydrodynamic impact. To scrutinize the hydrodynamic interactions in N partial-porous circular cylinders, the computational fluid domain is divided into three regions: an exterior region, N inner porous body regions, and N regions beneath the body. Wave excitation forces and wave run-up on multibodied partial-porous cylinders are calculated and compared for various porous-portion ratios and wave conditions, all of which significantly influence the hydrodynamic property.

Absolute measurement of the viscosity of classical and quantum fluids by rotating-cylinder viscometers

International Nuclear Information System (INIS)

Donnelly, R.J.; LaMar, M.M.

1987-01-01

We discuss the use of rotating-cylinder viscometers to determine absolute shear viscosities of classical fluids and of helium II in the context of past and current knowledge of the stability and flow of these fluids between concentric cylinders. We identify a problem in measuring the absolute viscosity when the inner cylinder is rotating and the outer cylinder is at rest. We conclude by discussing the design of viscometers for absolute viscosity measurements in helium I and helium II

Stress distribution and pressure-bearing capacity of a high-pressure split-cylinder die with prism cavity

Science.gov (United States)

Zhao, Liang; Li, Mingzhe; Wang, Liyan; Qu, Erhu; Yi, Zhuo

2018-03-01

A novel high-pressure belt-type die with a split-type cylinder is investigated with respect to extending its lifetime and improving its pressure bearing capacity. Specifically, a tungsten carbide cylinder is split into several parts along the radial direction with a prism-type cavity. In this paper, the cylinders with different split numbers are chosen to study the stress distribution and compare them with the traditional belt-type die. The simulation results indicate that the split cylinder has much smaller stress than those in the belt-type cylinder, and the statistical analysis reveals that the split-pressure cylinder is able to bear higher pressure. Experimental tests also show that the high-pressure die with a split cylinder and prism cavity has a stronger pressure-bearing capacity than a belt-type die. The split cylinder has advantages of easy manufacturing, high pressure bearing capacity, and replaceable performance.

Effect of intake swirl on the performance of single cylinder direct injection diesel engine

Science.gov (United States)

Sharma, Vinod Kumar; Mohan, Man; Mouli, Chandra

2017-11-01

In the present work, the effect of inlet manifold geometry and swirl intensity on the direct injection (DI) diesel engine performance was investigated experimentally. Modifications in inlet manifold geometry have been suggested to achieve optimized swirl for the better mixing of fuel with air. The intake swirl intensities of modified cylinder head were measured in swirl test rig at different valve lifts. Later, the overall performance of 435 CC DI diesel engine was measured using modified cylinder head. In addition, the performance of engine was compared for both modified and old cylinder head. For same operating conditions, the brake power and brake specific fuel consumption was improved by 6% and 7% respectively with modified cylinder head compared to old cylinder head. The maximum brake power of 9 HP was achieved for modified cylinder head. The results revealed that the intake swirl has great influence on engine performance.

Gas cylinder disposal pit remediation waste minimization and management

International Nuclear Information System (INIS)

Alas, C.A.; Solow, A.; Criswell, C.W.; Spengler, D.; Brannon, R.; Schwender, J.M.; Eckman, C.K.; Rusthoven, T.

1995-01-01

A remediation of a gas cylinder disposal pit at Sandia National Laboratories, New Mexico has recently been completed. The cleanup prevented possible spontaneous releases of hazardous gases from corroded cylinders that may have affected nearby active test areas at Sandia's Technical Area III. Special waste management, safety, and quality plans were developed and strictly implemented for this project. The project was conceived from a waste management perspective, and waste minimization and management were built into the planning and implementation phases. The site layout was planned to accommodate light and heavy equipment, storage of large quantities of suspect soil, and special areas to stage and treat gases and reactive chemicals removed from the pit, as well as radiation protection areas. Excavation was a tightly controlled activity using experienced gas cylinder and reactive chemical specialists. Hazardous operations were conducted at night under lights, to allow nearby daytime operations to function unhindered. The quality assurance plan provided specific control of, and documentation for, critical decisions, as well as the record of daily operations. Both hand and heavy equipment excavation techniques were utilized. Hand excavation techniques were utilized. Hand excavation techniques allows sealed glass containers to be exhumed unharmed. In the end, several dozen thermal batteries; 5 pounds (2.3 kg) of lithium metal; 6.6 pounds (3.0 kg) of rubidium metal; several kilograms of unknown chemicals; 140 cubic yards (107 cubic meters) of thorium-contaminated soil; 270 cubic yards (205 cubic meters) of chromium-contaminated soil; and 450 gas cylinders, including 97 intact cylinders containing inert, flammable, toxic, corrosive, or oxidizing gases were removed and effectively managed to minimize waste

Global Monitoring Of Uranium Hexifloride Cylinders Next Steps In Development Of An Action Plan

International Nuclear Information System (INIS)

Hanks, D.

2010-01-01

Over 40 industrial facilities world-wide use standardized uranium hexafluoride (UF 6 ) cylinders for transport, storage and in-process receiving in support of uranium conversion, enrichment and fuel fabrication processes. UF 6 is processed and stored in the cylinders, with over 50,000 tU of UF 6 transported each year in these International Organization for Standardization (ISO) qualified containers. Although each cylinder is manufactured to an ISO standard that calls for a nameplate with the manufacturer's identification number (ID) and the owner's serial number engraved on it, these can be quite small and difficult to read. Recognizing that each facility seems to use a different ID, a cylinder can have several different numbers recorded on it by means of metal plates, sticky labels, paint or even marker pen as it travels among facilities around the world. The idea of monitoring movements of UF 6 cylinders throughout the global uranium fuel cycle has become a significant issue among industrial and safeguarding stakeholders. Global monitoring would provide the locations, movements, and uses of cylinders in commercial nuclear transport around the world, improving the efficiency of industrial operations while increasing the assurance that growing nuclear commerce does not result in the loss or misuse of cylinders. It should be noted that a unique ID (UID) attached to a cylinder in a verifiable manner is necessary for safeguarding needs and ensuring positive ID, but not sufficient for an effective global monitoring system. Modern technologies for tracking and inventory control can pair the UID with sensors and secure data storage for content information and complete continuity of knowledge over the cylinder. This paper will describe how the next steps in development of an action plan for employing a global UF 6 cylinder monitoring network could be cultivated using four primary UID functions - identification, tracking, controlling, and accounting.

Effect of corner radius in stabilizing the low-Re flow past a cylinder

KAUST Repository

Zhang, Wei

2017-08-03

We perform global linear stability analysis on low-Re flow past an isolated cylinder with rounded corners. The objective of the present work is to investigate the effect of the cylinder geometry (corner radius) on the stability characteristics of the flow. Our investigation sheds light on new physics that the flow can be stabilized by partially rounding the cylinder in the critical and weakly super-critical flow regimes. The flow is first stabilized and then gradually destabilized as the cylinder varies from square to circular geometry. The sensitivity analysis reveals that the variation of stability is attributed to the different spatial variation trends of the backflow velocity in the near- and far-wake regions for various cylinder geometries. The results from the stability analysis are also verified with those of the direct simulations and very good agreement is achieved.

Effect of corner radius in stabilizing the low-Re flow past a cylinder

KAUST Repository

Zhang, Wei; Samtaney, Ravindra

2017-01-01

We perform global linear stability analysis on low-Re flow past an isolated cylinder with rounded corners. The objective of the present work is to investigate the effect of the cylinder geometry (corner radius) on the stability characteristics of the flow. Our investigation sheds light on new physics that the flow can be stabilized by partially rounding the cylinder in the critical and weakly super-critical flow regimes. The flow is first stabilized and then gradually destabilized as the cylinder varies from square to circular geometry. The sensitivity analysis reveals that the variation of stability is attributed to the different spatial variation trends of the backflow velocity in the near- and far-wake regions for various cylinder geometries. The results from the stability analysis are also verified with those of the direct simulations and very good agreement is achieved.

Rotational friction coefficient of a permeable cylinder in a viscous fluid

NARCIS (Netherlands)

Wiegel, F.W.

1979-01-01

An exact expression is derived for the rotational friction coefficient of a cylinder of infinite length and constant permeability immersed in an incompressible viscous fluid. An asymptotic expression for the translational friction coefficient of a permeable cylinder moving in a sheet of viscous

Testing of the Model 48-14 overpack for UF6 cylinders

International Nuclear Information System (INIS)

Stitt, D.H.

1983-01-01

Shipment of UF 6 enriched to 1.0% or greater assay 235 U currently is done in either the 30-B overpack or the Paducah tiger overpack. The former contains a 2-1/2 ton cylinder, 30 in. in diameter, while the latter contains a 10-ton cylinder, 48 in. in diameter. There are apparent economy and safety considerations associated with shipping in the larger containers due to the reduced number of shipments and connect and disconnect operations. Further reductions in connect and disconnect operations and shipping costs could be achieved through use of the 14-ton cylinder for shipment of enriched material. With this thought, a program was initiated in 1980 to develop a protective overpack for the Model 48Y cylinder. Two prototype overpacks of wood and stainless steel construction were fabricated. The results from the drop tests and the thermal exposure test are presented

Water Entry and Exit of Horizontal Cylinder in Free Surface Flow

International Nuclear Information System (INIS)

Hafsia, Zouhaier; Maalel, Khlifa; Mnasri, Chokri; Mohamed, Omri

2009-01-01

This paper describes two-dimensional numerical simulations of the water entry and exit of horizontal circular cylinder at constant velocity. The deformation of free surface is described by Navier-Stokes (N S) equations of incompressible and viscous fluid with additional transport equation of the volume-of-fluid (VOF). The motion of the cylinder is modeled by the associated momentum source term implemented in the Phoenicis (Parabolic Hyperbolic Or Elliptic Numerical Integration Code Series) code. The domain is discretized by a fixed Cartesian grid using a finite volume method and the cylinder is represented and cut cell method. The simulated results are compared with the numerical results of Lin (2007). This comparison shows good agreement in terms of free surface evolution for water exit and sinking. However, for water entry, the jet flow simulated by Lin is not reproduced. The free surface deformation around the cylinder in downward direction is accurately predicted

Evaluation of Flow Accelerated Corrosion of Carbon Steel with Rotating Cylinder

International Nuclear Information System (INIS)

Park, Tae Jun; Lee, Eun Hee; Kim, Kyung Mo; Kim, Hong Pyo

2012-01-01

Flow accelerated corrosion (FAC) of the carbon steel piping in nuclear power plants (NPPs) has been major issue in nuclear industry. Rotating cylinder FAC test facility was designed and fabricated and then performance of the facility was evaluated. The facility is very simple in design and economic in fabrication and can be used in material and chemistry screening test. The facility is equipped with on line monitoring of pH, conductivity, dissolved oxygen(DO), and temperature. Fluid velocity is controlled with rotating speed of the cylinder with a test specimen. FAC test of SA106 Gr. B carbon steel under 4 m/s flow velocity was performed with the rotating cylinder at DO concentration of less than 1 ppb and of 1.3 ppm. Also a corrosion test of the carbon steel at static condition, that is at zero fluid velocity, of test specimen and solution was performed at pH from 8 to 10 for comparison with the FAC data. For corrosion test in static condition, the amount of non adherent corrosion product was almost constant at pH ranging from 8 to 10. But adherent corrosion product decreased with increasing pH. This trend is consistent with decrease of Fe solubility with an increase in pH. For FAC test with rotating cylinder FAC test facility, the amount of non adherent corrosion product was also almost same for both DO concentrations. The rotating cylinder FAC test facility will be further improved by redesigning rotating cylinder and FAC specimen geometry for future work

Extended Analytic Linear Model of Hydraulic Cylinder With Respect Different Piston Areas and Volumes

OpenAIRE

Petr KOŇAŘÍK

2009-01-01

Standard analytic linear model of hydraulic cylinder usually comes from assumptions of identical action piston areas on both sides of hydraulic cylinder (double piston rod) and suitable operation point, which is usually chosen in the middle of piston. By reason of that volumes inside of cylinder are than same. Moreover for control of that arrangement of hydraulic cylinder, usually controlled by 4/3 servovalve, the same mount of flows comes in and comes out to each of chambers of hydraulic cyl...

Flow structure from a horizontal cylinder coincident with a free surface in shallow water flow

Directory of Open Access Journals (Sweden)

Kahraman Ali

2012-01-01

Full Text Available Vortex formation from a horizontal cylinder coincident with a free surface of a shallow water flow having a depth of 25.4 [mm] was experimentally investigated using the PIV technique. Instantaneous and time-averaged flow patterns in the wake region of the cylinder were examined for three different cylinder diameter values under the fully developed turbulent boundary layer condition. Reynolds numbers were in the range of 1124£ Re£ 3374 and Froude numbers were in the range of 0.41 £ Fr £ 0.71 based on the cylinder diameter. It was found that a jet-like flow giving rise to increasing the flow entrainment between the core and wake regions depending on the cylinder diameter was formed between the lower surface of the cylinder and bottom surface of the channel. Vorticity intensity, Reynolds stress correlations and the primary recirculating bubble lengths were grown to higher values with increasing the cylinder diameter. On the other hand, in the case of the lowest level of the jet-like flow emanating from the beneath of the smallest cylinder, the variation of flow characteristics were attenuated significantly in a shorter distance. The variation of the reattachment location of the separated flow to the free-surface is a strong function of the cylinder diameter and the Froude number.

Induced charge electrophoresis of a conducting cylinder in a nonconducting cylindrical pore and its micromotoring application

Science.gov (United States)

Feng, Huicheng; Wong, Teck Neng; Che, Zhizhao

2016-08-01

Induced charge electrophoresis of a conducting cylinder suspended in a nonconducting cylindrical pore is theoretically analyzed and a micromotor is proposed that utilizes the cylinder rotation. The cylinder velocities are analytically obtained in the Dirichlet and the Neumann boundary conditions of the electric field on the cylindrical pore. The results show that the cylinder not only translates but also rotates when it is eccentric with respect to the cylindrical pore. The influences of a number of parameters on the cylinder velocities are characterized in detail. The cylinder trajectories show that the cylinder approaches and becomes stationary at certain positions within the cylindrical pore. The proposed micromotor is capable of working under a heavy load with a high rotational velocity when the eccentricity is large and the applied electric field is strong.

Results of the remote sensing feasibility study for the uranium hexafluoride storage cylinder yard program

International Nuclear Information System (INIS)

Balick, L.K.; Bowman, D.R.

1997-02-01

The US DOE manages the safe storage of approximately 650,000 tons of depleted uranium hexafluoride remaining from the Cold War. This slightly radioactive, but chemically active, material is contained in more than 46,000 steel storage cylinders that are located at Oak Ridge, Tennessee; Paducah, Kentucky; and Portsmouth, Ohio. Some of the cylinders are more than 40 years old, and approximately 17,500 are considered problem cylinders because their physical integrity is questionable. These cylinders require an annual visual inspection. The remainder of the 46,000-plus cylinders must be visually inspected every four years. Currently, the cylinder inspection program is extremely labor intensive. Because these inspections are accomplished visually, they may not be effective in the early detection of leaking cylinders. The inspection program requires approximately 12--14 full-time-equivalent (FTE) employees. At the cost of approximately $125K per FTE, this translates to $1,500K per annum just for cylinder inspection. As part of the technology-development portion of the DOE Cylinder Management Program, the DOE Office of Facility Management requested the Remote Sensing Laboratory (RSL) to evaluate remote sensing techniques that have potential to increase the effectiveness of the inspection program and, at the same time, reduce inspection costs and personnel radiation exposure. During two site visits (March and May 1996) to the K-25 Site at Oak Ridge, TN, RSL personnel tested and characterized seven different operating systems believed to detect leakage, surface contamination, thickness and corrosion of cylinder walls, and general area contamination resulting from breached cylinders. The following techniques were used and their performances are discussed: Laser-induced fluorescent imaging; Long-range alpha detection; Neutron activation analysis; Differential gamma-ray attenuation; Compton scatterometry; Active infrared inspection; and Passive thermal infrared imaging

Richly innervated soft tissues covering the superficial aspect of the extensor origin in patients with chronic painful tennis elbow - Implication for treatment?

Science.gov (United States)

Spang, C; Alfredson, H

2017-06-01

Tennis elbow is difficult to treat. The results of surgical treatments are not convincing. Treatment studies on Achilles and patellar tendinopathy targeting the richly innervated and vascularized soft tissues outside the tendon have shown promising outcomes. The innervation patterns in the fibrous/fatty tissues superficially to the elbow extensor origin have not been clarified. Nine tissue specimens from the fibrous/fatty tissue covering the extensor origin was taken from seven patients (mean age: 45 years) undergoing surgical treatment for chronic painful tennis elbow. The specimens were stained for morphology (haematoxylin and eosin, H and E) and immunohistochemically for general nerve marker protein gene product 9.5 (PGP 9.5) and markers for sympathetic (tyrosine hydroxylase, TH) and sensory nerve fibres (calcitonin gene-related peptide, CGRP). All specimens contained multiple blood vessels and nerve structures indicated by morphology and immunoreactions. There was a frequent occurrence of TH reactions, especially peri-vascularly, but also in nerve fascicles. Immunoreactions for CGRP were seen in nerve fascicles and isolated nerve fibres. The results provide new information on the innervation patterns of the superficial tissues of the extensor origin and their potential as source of tennis elbow pain. IV.

Cylinder with differential piston for mass measurements

Energy Technology Data Exchange (ETDEWEB)

Bordeaşu, I.; Bălăşoiu, V. [Universitatea Politehnica din Timişoara, Timosoara (Romania); Hadă, A. [UniversitateaPolitehnicaBucureşti, Bucureşti (Romania); Popoviciu, M. [Academy of Romanian ScientistsTimişoara Branch (Romania)

2007-07-01

The paper presents a cylinder with differential piston, adapted for measuring the weight of fixed objects such as: fuel tanks (regardless of their capacity), bunkers and silos for all kind of materials, or mobile objects such as: automobiles, trucks, locomotives and railway cars. Although, the cylinder with differential piston is used on a large scale in hydraulic drive or hydraulic control circuits, till now it was not used as constituent part for weight measurements devices. The novelty of the present paper is precisely the use of the device for such purposes. Based on a computation algorithm, the paper presents the general design (assembly), of the device used for weighing important masses (1…. 100 tones). The fundamental idea consist in the fact that, a mass over 10 tones may be weighted with a helicoidally spring subjected to an axial force between 0 and 3000 N, with a deflection of about 30 mm. Simultaneously with the mechanical part, the electronic recording system is also described. The great advantage of the presented device consist in the fact that it can be used in heavy polluted atmosphere or difficult topographic conditions as a result of both the small dimensions and the protection systems adopted. Keywords: cylinder hydraulic with differential piston, hydrostatic pressure, measuring devices.

Experimental Study of 3D Movement in Cushioning of Hydraulic Cylinder

Directory of Open Access Journals (Sweden)

Antonio Algar

2017-05-01

Full Text Available A double acting cylinder operation has been fully monitored in its key functional parameters, focused on characterization of end-of-stroke cushioning and starting phases. Being the cylinder performance reliant in the piston constructive geometry, the number and location of piston circumferential grooves is a significant parameter affecting the internal cushioning system performance. An eddy current displacement sensor assembled in the piston allows assessment of piston radial displacement inside the cylinder tube, which is directly related with the studied operating phases. Due to such 3D displacements, the piston becomes as an active and self-adjusting element along the functional cycle of the cylinder. Mechanical joints orientation and operating pressure are also relevant parameters affecting piston radial displacement and, thus, the cushioning and starting performance. Computational Fluid Dynamics (CFD results confirm the observed functional role of the perimeter grooves; the flow and pressure distributions, where develops a significant radial force, are also in accordance with the registered radial displacement.

Magnus effect on laminar flow around a rotating cylinder

International Nuclear Information System (INIS)

Amarante, J.C.A.

1989-01-01

The laminar flow around a rotating cylinder is studied, through the numerical solution of the full Navier-Stokes equations, for Reynolds number, based on cylinder radius, varying between 0.5 and 25 and for non-dimensional tangential velocities of the body surface between zero and 8. The Taylor and Hughes method is employed in the theoretical investigation. The Magnus lift coefficient and the drag coefficient are obtained and the presure and vorticity distribution are calculated. (author)

Cylinders out of a top hat: counts-in-cells for projected densities

Science.gov (United States)

Uhlemann, Cora; Pichon, Christophe; Codis, Sandrine; L'Huillier, Benjamin; Kim, Juhan; Bernardeau, Francis; Park, Changbom; Prunet, Simon

2018-06-01

Large deviation statistics is implemented to predict the statistics of cosmic densities in cylinders applicable to photometric surveys. It yields few per cent accurate analytical predictions for the one-point probability distribution function (PDF) of densities in concentric or compensated cylinders; and also captures the density dependence of their angular clustering (cylinder bias). All predictions are found to be in excellent agreement with the cosmological simulation Horizon Run 4 in the quasi-linear regime where standard perturbation theory normally breaks down. These results are combined with a simple local bias model that relates dark matter and tracer densities in cylinders and validated on simulated halo catalogues. This formalism can be used to probe cosmology with existing and upcoming photometric surveys like DES, Euclid or WFIRST containing billions of galaxies.

Localized surface plasmon modes in a system of two interacting metallic cylinders

DEFF Research Database (Denmark)

Babicheva, Viktoriia; Vergeles, Sergey S.; Vorobev, Petr E.

2012-01-01

We study an optical response of a system of two parallel close metallic cylinders having nanoscale dimensions. Surface plasmon excitation in the gap between the cylinders are specifically analyzed. In particular, resonance frequencies and field enhancement were investigated as functions of geomet......We study an optical response of a system of two parallel close metallic cylinders having nanoscale dimensions. Surface plasmon excitation in the gap between the cylinders are specifically analyzed. In particular, resonance frequencies and field enhancement were investigated as functions...... of geometrical characteristics of the system and Ohmic losses in the metal. The results of numerical simulations were systematically compared with the analytical theory, obtained in the quasi-static limit. The analytical method was generalized in order to take into account the retardation effects. We also...

Analysis of residual stresses in a long hollow cylinder

International Nuclear Information System (INIS)

Tokovyy, Yuriy V.; Ma, Chien-Ching

2011-01-01

This paper presents an analytical method for solving the axisymmetric stress problem for a long hollow cylinder subjected to locally-distributed residual (incompatible) strains. This method is based on direct integration of the equilibrium and compatibility equations, which thereby have been reduced to the set of two governing equations for two key functions with corresponding boundary and integral conditions. The governing equations were solved by making use of the Fourier integral transformation. Application of the method is illustrated with an analysis of the welding residual stresses in a butt-welded thick-walled pipe. - Highlights: → A solution to the axisymmetric stress problem for a hollow cylinder is constructed. → The cylinder is subjected to a field of locally-distributed residual strains. → The method is based on direct integration of the equilibrium equations. → An application of our solution to analysis of welding residual stresses is considered.

Criticality safety review of 2 1/2-, 10-, and 14-ton UF6 cylinders

International Nuclear Information System (INIS)

Broadhead, B.L.

1991-10-01

Currently, UF 6 cylinders designed to contain 2 1/2 tons of UF 6 are classified as Fissile Class 2 packages with a transport index (TI) of 5 for the purpose of transportation. The 10-ton UF 6 cylinders are classified as Fissile Class 1 with no TI assigned for transportation. The 14-ton cylinders, although not certified for transport with enrichments greater than 1 wt % because they have no approved overpack, can be used in on-site operations for enrichments greater than 1 wt %. The maximum 235 U enrichments for these cylinders are 5.0 wt % for the 2 1/2-ton cylinder and 4.5 wt % for the 10- and 14-ton cylinders. This work reviews the suitability for reclassification of the 2 1/2-ton UF 6 packages as Fissile Class 1 with a maximum 235 U enrichment of 5 wt %. Additionally, the 10- and 14-ton cylinders are reviewed to address a change in maximum 235 U enrichment from 4.5 to 5 wt %. Based on this evaluation, the 2 1/2-ton UF 6 cylinders meet the 10 CFR.71 criteria for Fissile Class 1 packages, and no TI is needed for criticality safety purposes; however, a TI may be required based on radiation from the packages. Similarly, the 10- and 14-ton UF 6 packages appear acceptable for a maximum enrichment rating change to 5 wt % 235 U. 11 refs., 13 figs., 7 tabs

Evanescent wave scattering at off-axis incidence on multiple cylinders located near a surface

International Nuclear Information System (INIS)

Lee, Siu-Chun

2015-01-01

The scattering characteristics of an infinite cylinder are strongly influenced by the incidence angle relative to its axis. If the incident wave propagates in the plane normal to the axis of the cylinder, the polarization of the scattered wave remains unchanged and the scattered wave propagates in the same plan as the incident wave. At off-axis incidence such that the incident direction makes an oblique angle with the cylinder axis, the scattered wave is depolarized, and its spatial distribution becomes three-dimensional. This paper presents the scattering solution for oblique incidence on multiple parallel cylinders located near a planar interface by an evanescent wave that is generated by total internal reflection of the source wave propagating in the higher refractive index substrate. Hertz potentials are utilized to formulate the interaction of inhomogeneous waves with the cylinders, scattering at the substrate interface, and near field scattering between the cylinders. Analytic formulas are derived for the electromagnetic fields and Poynting vector of scattered radiation in the near-field and their asymptotic forms in the far-field. Numerical examples are shown to illustrate scattering of evanescent wave by multiple cylinders at off-axis incidence. - Highlights: • Developed an exact solution for off-axis incidence on multiple cylinders. • Included depolarization, near-field scattering, and Fresnel effect in theory. • Derived analytic formulas for scattered radiation in the far field. • Illustrated evanescent scattering at off-axis incidence by numerical data

Effect of catalytic cylinders on autothermal reforming of methane for hydrogen production in a microchamber reactor.

Science.gov (United States)

Yan, Yunfei; Guo, Hongliang; Zhang, Li; Zhu, Junchen; Yang, Zhongqing; Tang, Qiang; Ji, Xin

2014-01-01

A new multicylinder microchamber reactor is designed on autothermal reforming of methane for hydrogen production, and its performance and thermal behavior, that is, based on the reaction mechanism, is numerically investigated by varying the cylinder radius, cylinder spacing, and cylinder layout. The results show that larger cylinder radius can promote reforming reaction; the mass fraction of methane decreased from 26% to 21% with cylinder radius from 0.25 mm to 0.75 mm; compact cylinder spacing corresponds to more catalytic surface and the time to steady state is decreased from 40 s to 20 s; alteration of staggered and aligned cylinder layout at constant inlet flow rates does not result in significant difference in reactor performance and it can be neglected. The results provide an indication and optimize performance of reactor; it achieves higher conversion compared with other reforming reactors.

The Present Status of Using Natural Gas Cylinders and Acoustic Emission in Thailand

Science.gov (United States)

Jomdecha, C.; Jirarungsatian, C.; Methong, W.; Poopat, B.

This chapter presents the status of using natural gas cylinders (CNG/NGV) and acoustic emission (AE) in Thailand. During the period from 2006 to 2013, more than 600,000 CNG cylinder units for vehicles were installed and used for transportation, cars, and trucks in Thailand. The number of cylinder units will be tentatively increased in the future due to the increase in gasoline price. Due to the use of high-pressurization equipment in public, the issue of a risk to public safety has been raised. As of this writing, in 2013, the testing standard from the Thai Department of Energy Business recommends inspection every 5 years using effective inspection methods in order to guarantee safe usage of gas cylinders, including the AE method, following ISO 16148. Normally in Thailand, AE is used in research and petrochemical plants as a special technique. The main applications are testing of pressure vessels, aboveground storage tanks, and university research. Few companies are available to conduct AE for testing natural gas cylinders due to the limited safety of the high-pressure operation and AE equipment and a lack of qualified AE personnel. To develop AE techniques, equipment, procedures, and acceptance criteria of natural gas cylinders are the main focus of AE personnel in Thailand. A desired achievement for current development is for natural gas cylinder testing, which can be applied in field tests and supported by a national testing standard.

Characterization of fluid forces exerted on a cylinder array oscillating laterally in axial flow

International Nuclear Information System (INIS)

Divaret, Lise

2014-01-01

This thesis presents an experimental and a numerical study of the fluid forces exerted on a cylinder or a cylinder array oscillating laterally in an axial flow. The parameters of the system are the amplitude, the oscillation frequency, the confinement and the length to diameter ratio of the cylinder. The objective is to determine the fluid damping created by the axial flow, i.e. the dissipative force. The industrial application of this thesis is the determination of the fluid damping of the fuel assemblies in the core of a nuclear power plant during an earthquake. The study focuses on the configurations where the oscillation velocity is small compared to the axial flow velocity. In a first part, we study the case of a cylinder with no confinement oscillating in axial flow. Two methods are used: a dynamical and a quasi-static approach. In dynamics, the damping rate is measured during free oscillations of the cylinder. In the quasi-static approach, the damping coefficient is calculated from the normal force measured on a yawed cylinder. The range of the small ratios between the oscillation and the axial flow velocities corresponds to a range of low yaw angle where the cylinder is in near-axial flow in statics. The case of a yawed cylinder has been studied both experimentally with experiments in a wind tunnel and numerically with CFD calculations. The analyses of the fluid forces shows that for yaw angles smaller than 5 degrees, a linear lift with the yaw angle creates the damping. The origin of the lift force is discussed from pressure and velocity measurements. The results of the quasi-static approach are compared to the results of the dynamical experiments. In a second part, an experimental study is performed on a rigid cylinder array made up of 40 cylinders oscillating in an axial flow. The normal force and the displacement of the cylinder array are measured simultaneously. The added mass and damping coefficient are calculated and their variation with the

Effect of heat transfer in cylinder on air quantity of 4-stroke cycle gasoline engine; 4 Stroke gasoline engine no kyunyu shinkiryo ni oyobosu cylinder nai dennetsu no eikyo

Energy Technology Data Exchange (ETDEWEB)

Yoshida, M.; Oguri, Y.; Suzuki, T. [Sophia University, Tokyo (Japan). Faculty of Science and Technology

2000-01-25

Many papers concerning air quantity of 4-stroke cycle gasoline engine have been published. It has been reported in these papers that heat transfer in surface of cylinder and inlet port gives big influence to the air quantity. But it has not been clear which influence of heat transfer in cylinder and inlet port is strong. So the authors derived a function of the air quantity thermodynamically considering heat transfer, and examined which of influence of heat transfer was strong. The results show ; (1) The influence of heat transfer in cylinder is small (about 1%) at full load, and is also small (about 5%) at light load. (2) Heat transfer in cylinder almost increases the air quantity. (3) The influence of heat transfer in inlet port decreases the air quantity with around 30% greatly. (author)

Structural Stress Analysis of an Engine Cylinder Head

Directory of Open Access Journals (Sweden)

R. Tichánek

2005-01-01

Full Text Available This paper deals with a structural stress analysis of the cylinder head assembly of the C/28 series engine. A detailed FE model was created for this purpose. The FE model consists of the main parts of the cylinder head assembly, and it includes a description of the thermal and mechanical loads and the contact interaction between their parts. The model considers the temperature dependency of the heat transfer coefficient on wall temperature in cooling passages. The paper presents a comparison of computed and measured temperature. The analysis was carried out using the FE program ABAQUS. 

An experiment in heat conduction using hollow cylinders

Energy Technology Data Exchange (ETDEWEB)

Ortuno, M; Marquez, A; Gallego, S; Neipp, C; Belendez, A, E-mail: a.belendez@ua.es [Departamento de Fisica, IngenierIa de Sistemas y TeorIa de la Senal, Universidad de Alicante, Apartado 99, E-03080 Alicante (Spain)

2011-07-15

An experimental apparatus was designed and built to allow students to carry out heat conduction experiments in hollow cylinders made of different materials, as well as to determine the thermal conductivity of these materials. The evolution of the temperature difference between the inner and outer walls of the cylinder as a function of time is analysed, and when the process reaches the steady state regime the thermal conductivity can be easily calculated. Several materials such as wood, plastic and metals are considered and the values of their thermal conductivities, obtained experimentally, are compared with those given in the reference list.

Cylinder head fastening structure for internal combustion engines

Energy Technology Data Exchange (ETDEWEB)

Futakuchi, Y.; Oshiro, N.

1988-01-26

In a construction for an overhead cam internal combustion engine comprising a cylinder head adapted to be affixed to another component of the engine by at least one fastener having a tool receiving portion for tightening thereof and having a bearing cap affixed to the cylinder head and rotatably journaling the overhead camshaft, the improvement is described comprising the bearing cap having a portion overlying the fastener tool receiving portion, and means defining an access opening passing through the bearing cap and adapted to pass a tool for tightening of the fastener without removal of the bearing cap.

Development of Advanced In-Cylinder Components and Tribological Systems for Low Heat Rejection Diesel Engines

Science.gov (United States)

Yonushonis, T. M.; Wiczynski, P. D.; Myers, M. R.; Anderson, D. D.; McDonald, A. C.; Weber, H. G.; Richardson, D. E.; Stafford, R. J.; Naylor, M. G.

1999-01-01

In-cylinder components and tribological system concepts were designed, fabricated and tested at conditions anticipated for a 55% thermal efficiency heavy duty diesel engine for the year 2000 and beyond. A Cummins L10 single cylinder research engine was used to evaluate a spherical joint piston and connecting rod with 19.3 MPa (2800 psi) peak cylinder pressure capability, a thermal fatigue resistant insulated cylinder head, radial combustion seal cylinder liners, a highly compliant steel top compression ring, a variable geometry turbocharger, and a microwave heated particulate trap. Components successfully demonstrated in the final test included spherical joint connecting rod with a fiber reinforced piston, high conformability steel top rings with wear resistant coatings, ceramic exhaust ports with strategic oil cooling and radial combustion seal cylinder liner with cooling jacket transfer fins. A Cummins 6B diesel was used to develop the analytical methods, materials, manufacturing technology and engine components for lighter weight diesel engines without sacrificing performance or durability. A 6B diesel engine was built and tested to calibrate analytical models for the aluminum cylinder head and aluminum block.

An efficient cost function for the optimization of an n-layered isotropic cloaked cylinder

International Nuclear Information System (INIS)

Paul, Jason V; Collins, Peter J; Coutu, Ronald A Jr

2013-01-01

In this paper, we present an efficient cost function for optimizing n-layered isotropic cloaked cylinders. Cost function efficiency is achieved by extracting the expression for the angle independent scatterer contribution of an associated Green's function. Therefore, since this cost function is not a function of angle, accounting for every bistatic angle is not necessary and thus more efficient than other cost functions. With this general and efficient cost function, isotropic cloaked cylinders can be optimized for many layers and material parameters. To demonstrate this, optimized cloaked cylinders made of 10, 20 and 30 equal thickness layers are presented for TE and TM incidence. Furthermore, we study the effect layer thickness has on optimized cloaks by optimizing a 10 layer cloaked cylinder over the material parameters and individual layer thicknesses. The optimized material parameters in this effort do not exhibit the dual nature that is evident in the ideal transformation optics design. This indicates that the inevitable field penetration and subsequent PEC boundary condition at the cylinder must be taken into account for an optimal cloaked cylinder design. Furthermore, a more effective cloaked cylinder can be designed by optimizing both layer thickness and material parameters than by additional layers alone. (paper)

Stability of plasma cylinder with current in a helical plasma flow

Science.gov (United States)

Leonovich, Anatoly S.; Kozlov, Daniil A.; Zong, Qiugang

2018-04-01

Stability of a plasma cylinder with a current wrapped by a helical plasma flow is studied. Unstable surface modes of magnetohydrodynamic (MHD) oscillations develop at the boundary of the cylinder enwrapped by the plasma flow. Unstable eigenmodes can also develop for which the plasma cylinder is a waveguide. The growth rate of the surface modes is much higher than that for the eigenmodes. It is shown that the asymmetric MHD modes in the plasma cylinder are stable if the velocity of the plasma flow is below a certain threshold. Such a plasma flow velocity threshold is absent for the symmetric modes. They are unstable in any arbitrarily slow plasma flows. For all surface modes there is an upper threshold for the flow velocity above which they are stable. The helicity index of the flow around the plasma cylinder significantly affects both the Mach number dependence of the surface wave growth rate and the velocity threshold values. The higher the index, the lower the upper threshold of the velocity jump above which the surface waves become stable. Calculations have been carried out for the growth rates of unstable oscillations in an equilibrium plasma cylinder with current serving as a model of the low-latitude boundary layer (LLBL) of the Earth's magnetic tail. A tangential discontinuity model is used to simulate the geomagnetic tail boundary. It is shown that the magnetopause in the geotail LLBL is unstable to a surface wave (having the highest growth rate) in low- and medium-speed solar wind flows, but becomes stable to this wave in high-speed flows. However, it can remain weakly unstable to the radiative modes of MHD oscillations.

GLOBAL MONITORING OF URANIUM HEXIFLORIDE CYLINDERS NEXT STEPS IN DEVELOPMENT OF AN ACTION PLAN

Energy Technology Data Exchange (ETDEWEB)

Hanks, D.

2010-06-09

Over 40 industrial facilities world-wide use standardized uranium hexafluoride (UF{sub 6}) cylinders for transport, storage and in-process receiving in support of uranium conversion, enrichment and fuel fabrication processes. UF{sub 6} is processed and stored in the cylinders, with over 50,000 tU of UF{sub 6} transported each year in these International Organization for Standardization (ISO) qualified containers. Although each cylinder is manufactured to an ISO standard that calls for a nameplate with the manufacturer's identification number (ID) and the owner's serial number engraved on it, these can be quite small and difficult to read. Recognizing that each facility seems to use a different ID, a cylinder can have several different numbers recorded on it by means of metal plates, sticky labels, paint or even marker pen as it travels among facilities around the world. The idea of monitoring movements of UF{sub 6} cylinders throughout the global uranium fuel cycle has become a significant issue among industrial and safeguarding stakeholders. Global monitoring would provide the locations, movements, and uses of cylinders in commercial nuclear transport around the world, improving the efficiency of industrial operations while increasing the assurance that growing nuclear commerce does not result in the loss or misuse of cylinders. It should be noted that a unique ID (UID) attached to a cylinder in a verifiable manner is necessary for safeguarding needs and ensuring positive ID, but not sufficient for an effective global monitoring system. Modern technologies for tracking and inventory control can pair the UID with sensors and secure data storage for content information and complete continuity of knowledge over the cylinder. This paper will describe how the next steps in development of an action plan for employing a global UF{sub 6} cylinder monitoring network could be cultivated using four primary UID functions - identification, tracking, controlling, and

Efferent innervation of turtle semicircular canal cristae: comparisons with bird and mouse

Science.gov (United States)

Jordan, Paivi M.; Fettis, Margaret; Holt, Joseph C.

2014-01-01

In the vestibular periphery of nearly every vertebrate, cholinergic vestibular efferent neurons give rise to numerous presynaptic varicosities that target hair cells and afferent processes in the sensory neuroepithelium. Although pharmacological studies have described the postsynaptic actions of vestibular efferent stimulation in several species, characterization of efferent innervation patterns and the relative distribution of efferent varicosities among hair cells and afferents are also integral to understanding how efferent synapses operate. Vestibular efferent markers, however, have not been well characterized in the turtle, one of the animal models utilized by our laboratory. Here, we sought to identify reliable efferent neuronal markers in the vestibular periphery of turtle, to utilize these markers to understand how efferent synapses are organized, and to compare efferent neuronal labeling patterns in turtle with two other amniotes using some of the same markers. Efferent fibers and varicosities were visualized in the semicircular canal of Red-Eared Turtles (Trachemys scripta elegans), Zebra Finches (Taeniopygia guttata), and mice (Mus musculus) utilizing fluorescent immunohistochemistry with antibodies against choline acetyltransferase (ChAT). Vestibular hair cells and afferents were counterstained using antibodies to myosin VIIa and calretinin. In all species, ChAT labeled a population of small diameter fibers giving rise to numerous spherical varicosities abutting type II hair cells and afferent processes. That these ChAT-positive varicosities represent presynaptic release sites were demonstrated by colabeling with antibodies against the synaptic vesicle proteins synapsin I, SV2, or syntaxin and the neuropeptide calcitonin gene-related peptide (CGRP). Comparisons of efferent innervation patterns among the three species are discussed. PMID:25560461

Scattering by multiple parallel radially stratified infinite cylinders buried in a lossy half space.

Science.gov (United States)

Lee, Siu-Chun

2013-07-01

The theoretical solution for scattering by an arbitrary configuration of closely spaced parallel infinite cylinders buried in a lossy half space is presented in this paper. The refractive index and permeability of the half space and cylinders are complex in general. Each cylinder is radially stratified with a distinct complex refractive index and permeability. The incident radiation is an arbitrarily polarized plane wave propagating in the plane normal to the axes of the cylinders. Analytic solutions are derived for the electric and magnetic fields and the Poynting vector of backscattered radiation emerging from the half space. Numerical examples are presented to illustrate the application of the scattering solution to calculate backscattering from a lossy half space containing multiple homogeneous and radially stratified cylinders at various depths and different angles of incidence.

MATHEMATICAL METHODS TO DETERMINE THE INTERSECTION CURVES OF THE CYLINDERS

Directory of Open Access Journals (Sweden)

POPA Carmen

2010-07-01

Full Text Available The aim of this paper is to establish the intersection curves between cylinders, by using the Mathematica program. This thing can be obtained by introducing the curves equations, which are inferred, in Mathematica program. This paper take into discussion three right cylinders and another inclined to 45 degrees. The intersection curves can also be obtained by using the classical methods of the descriptive geometry.

Gas storage cylinder formed from a composition containing thermally exfoliated graphite

Science.gov (United States)

Prud'Homme, Robert K. (Inventor); Aksay, Ilhan A. (Inventor)

2012-01-01

A gas storage cylinder or gas storage cylinder liner, formed from a polymer composite, containing at least one polymer and a modified graphite oxide material, which is a thermally exfoliated graphite oxide with a surface area of from about 300 m(exp 2)/g to 2600 m(exp 2)2/g.

Mechanism of transition to turbulence in a circular cylinder wake in a channel

Directory of Open Access Journals (Sweden)

Molochnikov Valery

2017-01-01

Full Text Available Transition to turbulence in the circular cylinder wake has been studied experimentally and numerically at growing Reynolds number. Good agreement of calculation results with the flow visualization and measurements of instantaneous vector fields of velocity and vorticity has been demonstrated. The growing Reynolds number is shown to make large-scale vortex generation onset move upstream. It also triggers the transition to 3D flow pattern in the cylinder wake. This process is accompanied by non-monotonous behavior of the profiles of velocity and its turbulent fluctuations at equal distances from the cylinder. Non-monotonous behavior of the cylinder drag has been revealed for the Reynolds numbers ranging from 120 to 300.

Mathematic modelling of circular cylinder deformation under inner grouwth

Directory of Open Access Journals (Sweden)

A. V. Siasiev

2009-09-01

Full Text Available A task on the intensive deformed state (IDS of a viscoelastic declivous cylinder, which is grown under the action of inner pressure, is considered. The process of continuous increase takes a place on an internal radius so, that a radius and pressure change on set to the given law. The special case of linear law of creeping is considered, and also numeral results are presented as the graphs of temporal dependence of tensions and moving for different points of cylinder.

Effect of Catalytic Cylinders on Autothermal Reforming of Methane for Hydrogen Production in a Microchamber Reactor

Directory of Open Access Journals (Sweden)

Yunfei Yan

2014-01-01

Full Text Available A new multicylinder microchamber reactor is designed on autothermal reforming of methane for hydrogen production, and its performance and thermal behavior, that is, based on the reaction mechanism, is numerically investigated by varying the cylinder radius, cylinder spacing, and cylinder layout. The results show that larger cylinder radius can promote reforming reaction; the mass fraction of methane decreased from 26% to 21% with cylinder radius from 0.25 mm to 0.75 mm; compact cylinder spacing corresponds to more catalytic surface and the time to steady state is decreased from 40 s to 20 s; alteration of staggered and aligned cylinder layout at constant inlet flow rates does not result in significant difference in reactor performance and it can be neglected. The results provide an indication and optimize performance of reactor; it achieves higher conversion compared with other reforming reactors.

Analysis of an indirect neutron signature for enhanced UF_6 cylinder verification

International Nuclear Information System (INIS)

Kulisek, J.A.; McDonald, B.S.; Smith, L.E.; Zalavadia, M.A.; Webster, J.B.

2017-01-01

The International Atomic Energy Agency (IAEA) currently uses handheld gamma-ray spectrometers combined with ultrasonic wall-thickness gauges to verify the declared enrichment of uranium hexafluoride (UF_6) cylinders. The current method provides relatively low accuracy for the assay of "2"3"5U enrichment, especially for natural and depleted UF_6. Furthermore, the current method provides no capability to assay the absolute mass of "2"3"5U in the cylinder due to the localized instrument geometry and limited penetration of the 186-keV gamma-ray signature from "2"3"5U. Also, the current verification process is a time-consuming component of on-site inspections at uranium enrichment plants. Toward the goal of a more-capable cylinder assay method, the Pacific Northwest National Laboratory has developed the hybrid enrichment verification array (HEVA). HEVA measures both the traditional 186-keV direct signature and a non-traditional, high-energy neutron-induced signature (HEVA_N_T). HEVA_N_T enables full-volume assay of UF_6 cylinders by exploiting the relatively larger mean free paths of the neutrons emitted from the UF_6. In this work, Monte Carlo modeling is used as the basis for characterizing HEVA_N_T in terms of the individual contributions to HEVA_N_T from nuclides and hardware components. Monte Carlo modeling is also used to quantify the intrinsic efficiency of HEVA for neutron detection in a cylinder-assay geometry. Modeling predictions are validated against neutron-induced gamma-ray spectra from laboratory measurements and a relatively large population of Type 30B cylinders spanning a range of enrichments. Implications of the analysis and findings on the viability of HEVA for cylinder verification are discussed, such as the resistance of the HEVA_N_T signature to manipulation by the nearby placement of neutron-conversion materials.

Engine cylinder pressure reconstruction using crank kinematics and recurrently-trained neural networks

Science.gov (United States)

Bennett, C.; Dunne, J. F.; Trimby, S.; Richardson, D.

2017-02-01

A recurrent non-linear autoregressive with exogenous input (NARX) neural network is proposed, and a suitable fully-recurrent training methodology is adapted and tuned, for reconstructing cylinder pressure in multi-cylinder IC engines using measured crank kinematics. This type of indirect sensing is important for cost effective closed-loop combustion control and for On-Board Diagnostics. The challenge addressed is to accurately predict cylinder pressure traces within the cycle under generalisation conditions: i.e. using data not previously seen by the network during training. This involves direct construction and calibration of a suitable inverse crank dynamic model, which owing to singular behaviour at top-dead-centre (TDC), has proved difficult via physical model construction, calibration, and inversion. The NARX architecture is specialised and adapted to cylinder pressure reconstruction, using a fully-recurrent training methodology which is needed because the alternatives are too slow and unreliable for practical network training on production engines. The fully-recurrent Robust Adaptive Gradient Descent (RAGD) algorithm, is tuned initially using synthesised crank kinematics, and then tested on real engine data to assess the reconstruction capability. Real data is obtained from a 1.125 l, 3-cylinder, in-line, direct injection spark ignition (DISI) engine involving synchronised measurements of crank kinematics and cylinder pressure across a range of steady-state speed and load conditions. The paper shows that a RAGD-trained NARX network using both crank velocity and crank acceleration as input information, provides fast and robust training. By using the optimum epoch identified during RAGD training, acceptably accurate cylinder pressures, and especially accurate location-of-peak-pressure, can be reconstructed robustly under generalisation conditions, making it the most practical NARX configuration and recurrent training methodology for use on production engines.

A Tendon Cell Specific RNAi Screen Reveals Novel Candidates Essential for Muscle Tendon Interaction.

Directory of Open Access Journals (Sweden)

Prabhat Tiwari

Full Text Available Tendons are fibrous connective tissue which connect muscles to the skeletal elements thus acting as passive transmitters of force during locomotion and provide appropriate body posture. Tendon-derived cues, albeit poorly understood, are necessary for proper muscle guidance and attachment during development. In the present study, we used dorsal longitudinal muscles of Drosophila and their tendon attachment sites to unravel the molecular nature of interactions between muscles and tendons. We performed a genetic screen using RNAi-mediated knockdown in tendon cells to find out molecular players involved in the formation and maintenance of myotendinous junction and found 21 candidates out of 2507 RNAi lines screened. Of these, 19 were novel molecules in context of myotendinous system. Integrin-βPS and Talin, picked as candidates in this screen, are known to play important role in the cell-cell interaction and myotendinous junction formation validating our screen. We have found candidates with enzymatic function, transcription activity, cell adhesion, protein folding and intracellular transport function. Tango1, an ER exit protein involved in collagen secretion was identified as a candidate molecule involved in the formation of myotendinous junction. Tango1 knockdown was found to affect development of muscle attachment sites and formation of myotendinous junction. Tango1 was also found to be involved in secretion of Viking (Collagen type IV and BM-40 from hemocytes and fat cells.

Lubrication of ceramics in ring/cylinder applications

International Nuclear Information System (INIS)

Gaydos, P.A.; Dufrane, K.F.

1989-01-01

In support of efforts to apply ceramics to advanced heat engines, a study was performed of the wear mechanisms of ceramics at the ring/cylinder interface. A laboratory apparatus was constructed to reproduce most of the conditions of an actual engine but used easily prepared ring and cylinder specimens to facilitate their fabrication. Plasma-sprayed coatings of Cr 2 O 3 and hypersonic flame-sprayed coatings of cobalt-bonded WC performed particularly well as ring coatings. Similar performance was obtained with these coatings operating against SiC, Si 3 N 4 , SiC whisker-reinforced Al 2 O 3 and Cr 2 O 2 coatings. The study demonstrated the critical need for lubrication and evaluated the performance of two available lubricants

On the development of lift and drag in a rotating and translating cylinder

Science.gov (United States)

Martin-Alcantara, Antonio; Sanmiguel-Rojas, Enrique; Fernandez-Feria, Ramon

2014-11-01

The two-dimensional flow around a rotating cylinder is investigated numerically using a vorticity forces formulation with the aim of analyzing the flow structures, and their evolutions, that contribute to the lift and drag forces on the cylinder. The Reynolds number, based on the cylinder diameter and steady free-stream speed, considered is Re = 200 , while the non-dimensional rotation rate (ratio of the surface speed and free-stream speed) selected were α = 1 and 3. For α = 1 the wake behind the cylinder for the fully developed flow is oscillatory due to vortex shedding, and so are the lift and drag forces. For α = 3 the fully developed flow is steady with constant (high) lift and (low) drag. Each of these cases is considered in two different transient problems, one with angular acceleration of the cylinder and constant speed, and the other one with translating acceleration of the cylinder and constant rotation. Special attention is paid to explaining the mechanisms of vortex shedding suppression for high rotation (when α = 3) and its relation to the mechanisms by which the lift is enhanced and the drag is almost suppressed when the fully developed flow is reached. Supported by the Ministerio de Economia y Competitividad of Spain Grant No. DPI2013-40479-P.

Dynamics of spherical metallic particles in cylinder electrostatic separators/purifiers.

Science.gov (United States)

Lu, Hong-Zhou; Li, Jia; Guo, Jie; Xu, Zhen-Ming

2008-08-15

This paper presents a theoretical analysis of the dynamics of spherical metallic particles in electrostatic separators/purifiers (ESPs). The particle equations of motion are numerically solved in two dimensions using a computational algorithm. The ESPs consist of a pair of conductor cylinder electrodes. The upper cylinder is energized by HVdc, while the lower one is grounded and fixed horizontally on a revolvable axis. Some phenomena and aspects of separation process are explained and depicted including lifting off, impact, "motion collapse" and "sudden bouncing". The results reveal that the several phenomena depend on initial position, radius and density of the particle, curvature of the cylinder electrodes, distance between the electrodes and amplitude of the applied voltage. Optimization of the parameters is presented in order to get better separation/purification processes.

Integrated approach for stress analysis of high performance diesel engine cylinder head

Science.gov (United States)

Chainov, N. D.; Myagkov, L. L.; Malastowski, N. S.; Blinov, A. S.

2018-03-01

Growing thermal and mechanical loads due to development of engines with high level of a mean effective pressure determine requirements to cylinder head durability. In this paper, computational schemes for thermal and mechanical stress analysis of a high performance diesel engine cylinder head were described. The most important aspects in this approach are the account of temperature fields of conjugated details (valves and saddles), heat transfer modeling in a cooling jacket of a cylinder head and topology optimization of the detail force scheme. Simulation results are shown and analyzed.

Natural Gas Vehicle Cylinder Safety, Training and Inspection Project

Energy Technology Data Exchange (ETDEWEB)

Hank Seiff

2008-12-31

Under the auspices of the National Energy Technology Laboratory and the US Department of Energy, the Clean Vehicle Education Foundation conducted a three-year program to increase the understanding of the safe and proper use and maintenance of vehicular compressed natural gas (CNG) fuel systems. High-pressure fuel systems require periodic inspection and maintenance to insure safe and proper operation. The project addressed the needs of CNG fuel containers (cylinders) and associated high-pressure fuel system components related to existing law, codes and standards (C&S), available training and inspection programs, and assured coordination among vehicle users, public safety officials, fueling station operators and training providers. The program included a public and industry awareness campaign, establishment and administration of a cylinder inspector certification training scholarship program, evaluation of current safety training and testing practices, monitoring and investigation of CNG vehicle incidents, evaluation of a cylinder recertification program and the migration of CNG vehicle safety knowledge to the nascent hydrogen vehicle community.

Shaping the Microstructure of Cast Iron Automobile Cylinder Liners Aimed at Providing High Service Properties

Directory of Open Access Journals (Sweden)

Orłowicz A.W.

2015-06-01

Full Text Available The paper presents an analysis of factors affecting the wear of cylinder liners. The effect of the graphite precipitation morphology on the cylinder liner wear mechanism is presented. Materials used to cast cylinder liners mounted in a number of engines have been examined for their conformity with requirements set out in applicable Polish industrial standard. A casting for a prototype cylinder liner has been made with a microstructure guaranteeing good service properties of the part.

Control of the flow in the annular region of a shrouded cylinder with splitter plate

Directory of Open Access Journals (Sweden)

Ozkan Gokturk Memduh

2017-01-01

Full Text Available In the present study, the flow control with a splitter plate was studied considering the annular region of a shrouded cylinder. The effect of splitter plate angle, α which was defined according to the cylinder centreline is investigated experimentally in deep water using Particle image Velocimetry (PIV technique and flow visualization by dye injection method. The range of splitter plate angle was selected within 60°≤ α ≤180° with an increment of 30°. The porosity of the shroud which is a perforated cylinder was selected as β=0.7 in order to have larger fluid entrainment through the cylinder. The results were compared with the no-plate case and showed that the splitter plate located in the annular region of shrouded cylinders is effective on reducing the turbulence levels just behind the cylinder base, as well as the near wake of the perforated shroud.

Control of the flow in the annular region of a shrouded cylinder with splitter plate

Science.gov (United States)

Ozkan, Gokturk Memduh; Durhasan, Tahir; Pinar, Engin; Yenicun, Arda; Akilli, Huseyin; Sahin, Besir

In the present study, the flow control with a splitter plate was studied considering the annular region of a shrouded cylinder. The effect of splitter plate angle, α which was defined according to the cylinder centreline is investigated experimentally in deep water using Particle image Velocimetry (PIV) technique and flow visualization by dye injection method. The range of splitter plate angle was selected within 60°≤ α ≤180° with an increment of 30°. The porosity of the shroud which is a perforated cylinder was selected as β=0.7 in order to have larger fluid entrainment through the cylinder. The results were compared with the no-plate case and showed that the splitter plate located in the annular region of shrouded cylinders is effective on reducing the turbulence levels just behind the cylinder base, as well as the near wake of the perforated shroud.

A Design to Digitalize Hydraulic Cylinder Control of a Machine Tool ...

African Journals Online (AJOL)

Conventionally hydraulic piston - cylinder servos are actuated using analogue controls for machine tool axis drives. In this paper a design of the axis control system of an NC milling machine which employs a small stepping motor to digitally actuated hydraulic piston - cylinder servo drives existing on the machines Y-axis is ...

Rupture of Model 48Y UF6 cylinder and release of uranium hexafluoride. Cylinder overfill, March 12-13, 1986. Investigation of a failed UF6 shipping container. Volume 2

International Nuclear Information System (INIS)

1986-06-01

NUREG-1179, Volume 1, reported on the rupture of a Model 48Y uranium hexafluoride (UF 6 ) cylinder and the subsequent release of UF 6 . At the time of publication, a detailed metallurgical examination of the damaged cylinder was under way and results were not available. Subsequent to the publication of Volume 1, a second incident occurred at the Sequoyah Fuels Corporation facility. On March 13, 1986, a Model 48X cylinder was overfilled during a special one-time draining procedure; however, no release of UF 6 occurred. An Augmented Investigation Team investigated this second incident. This report, NUREG-1179, Volume 2, presents the findings made by the Augmented Investigation Team of the March 13 incident and the report of the detailed metallurgical examination conducted by Battelle Columbus Division of the cylinder damaged on January 4, 1986

Dorsal root ganglion neurons innervating skeletal muscle respond to physiological combinations of protons, ATP, and lactate mediated by ASIC, P2X, and TRPV1.

Science.gov (United States)

Light, Alan R; Hughen, Ronald W; Zhang, Jie; Rainier, Jon; Liu, Zhuqing; Lee, Jeewoo

2008-09-01

The adequate stimuli and molecular receptors for muscle metaboreceptors and nociceptors are still under investigation. We used calcium imaging of cultured primary sensory dorsal root ganglion (DRG) neurons from C57Bl/6 mice to determine candidates for metabolites that could be the adequate stimuli and receptors that could detect these stimuli. Retrograde DiI labeling determined that some of these neurons innervated skeletal muscle. We found that combinations of protons, ATP, and lactate were much more effective than individually applied compounds for activating rapid calcium increases in muscle-innervating dorsal root ganglion neurons. Antagonists for P2X, ASIC, and TRPV1 receptors suggested that these three receptors act together to detect protons, ATP, and lactate when presented together in physiologically relevant concentrations. Two populations of muscle-innervating DRG neurons were found. One responded to low metabolite levels (likely nonnoxious) and used ASIC3, P2X5, and TRPV1 as molecular receptors to detect these metabolites. The other responded to high levels of metabolites (likely noxious) and used ASIC3, P2X4, and TRPV1 as their molecular receptors. We conclude that a combination of ASIC, P2X5 and/or P2X4, and TRPV1 are the molecular receptors used to detect metabolites by muscle-innervating sensory neurons. We further conclude that the adequate stimuli for muscle metaboreceptors and nociceptors are combinations of protons, ATP, and lactate.

Ontogeny and innervation of taste buds in mouse palatal gustatory epithelium.

Science.gov (United States)

Rashwan, Ahmed; Konishi, Hiroyuki; El-Sharaby, Ashraf; Kiyama, Hiroshi

2016-01-01

We investigated the relationship between mouse taste bud development and innervation of the soft palate. We employed scanning electron microscopy and immunohistochemistry using antibodies against protein gene product 9.5 and peripherin to detect sensory nerves, and cytokeratin 8 and α-gustducin to stain palatal taste buds. At E14, nerve fibers were observed along the medial border of the palatal shelves that tracked toward the epithelium. At E15.5, primordial stages of taste buds in the basal lamina of the soft palate first appeared. At E16, the taste buds became large spherical masses of columnar cells scattered in the soft palate basal lamina. At E17, the morphology and also the location of taste buds changed. At E18-19, some taste buds acquired a more elongated shape with a short neck, extending a variable distance from the soft palate basal lamina toward the surface epithelium. At E18, mature taste buds with taste pores and perigemmal nerve fibers were observed on the surface epithelium of the soft palate. The expression of α-gustducin was demonstrated at postnatal day 1 and the number of pored taste buds increased with age and they became pear-shaped at 8 weeks. The percent of pored fungiform-like papillae at birth was 58.3% of the whole palate; this increased to 83.8% at postnatal day 8 and reached a maximum of 95.7% at 12 weeks. The innervation of the soft palate was classified into three types of plexuses in relation to taste buds: basal nerve plexus, intragemmal and perigemmal nerve fibers. This study reveals that the nerve fibers preceded the development of taste buds in the palate of mice, and therefore the nerve fibers have roles in the initial induction of taste buds in the soft palate. Copyright © 2015 Elsevier B.V. All rights reserved.

Interface dilation : the overflowing cylinder technique

NARCIS (Netherlands)

Bergink - Martens, D.J.M.

1993-01-01

A pure steady-state dilation of a liquid interface, either liquid-air or water-oil, can be accomplished far from equilibrium by means of the overflowing cylinder technique. The resulting dynamic surface tension data correlate well with characteristic parameters of processes like foaming,

Cluster-based Reduced-order Modelling of Flow in the Wake of a Seal-vibrissa-shaped Cylinder

Science.gov (United States)

Wei, Zheng; Li, Qiliang; Yang, Zhigang; Xia, Chao; Shanghai Automotive Wind Tunnel Center Team

2017-11-01

The flow around a seal-vibrissa-shaped cylinder is numerically calculated using large eddy simulation (LES) at the Reynolds number of 20000, along with a smooth and a twisted cylinder for comparison. The mean drag coefficient of the seal-vibrissa-shaped cylinder is lower than that of the smooth and twisted cylinders, respectively. The fluctuating lift coefficient of the seal-vibrissa-shaped cylinder shows a substantial decrease compared with the smooth cylinder. The seal-vibrissa-shaped surface leads to more stable wake, longer vortex formation length, higher base pressure and three-dimensional separation. In addition, cluster-based reduced-order modelling (CROM) is performed to analyze phase-dependent variations of the wake flow, which discloses the complex unsteady behavior in different cross sections. Meanwhile, two flow regimes, anti-phased and in-phase-dominated vortex shedding, generated by the twisted cylinder and the seal-vibrissa-shaped cylinder are distinguished and extracted, their interrelationship are evaluated, and the question how forces are affected is answered. Supported by the National Key Research and Development Program of China (2016YFB1200503-04) and the Shanghai Automotive Wind Tunnel Technical Service Platform (16DZ2290400).

Natural convection in a cubical cavity with a coaxial heated cylinder

Energy Technology Data Exchange (ETDEWEB)

Aithal, S. M.

2018-03-01

High-resolution three-dimensional simulations were conducted to investigate the velocity and temperature fields in a cold cubical cavity due to natural convection induced by a centrally placed hot cylinder. Unsteady, incompressible Navier-Stokes equations were solved by using a spectral- element method for Rayleigh numbers ranging from 103 to 109. The effect of spanwise thermal boundary conditions, aspect ratio (radius of the cylinder to the side of the cavity), and spanwise temperature distribution of the inner cylinder on the velocity and thermal fields were investigated for each Rayleigh number. Results from two-dimensional calculations were compared with three-dimensional simulations. The 3D results indicate a complex flow structure in the vicinity of the spanwise walls. The results also show that the imposed thermal wall boundary condition impacts the flow and temperature fields strongly near the spanwise walls. The variation of the local Nusselt number on the cylinder surface and enclosure walls at various spanwise locations was also investigated. The local Nusselt number on the cylinder surface and enclosure walls at the cavity mid-plane (Z = 0) is close to 2D simulations for 103 ≤ Ra ≤ 108. Simulations also show a variation in the local Nusselt number, on both the cylinder surface and the enclosure walls, in the spanwise direction, for all Rayleigh numbers studied in this work. The results also indicate that if the enclosure walls are insulated in the spanwise direction (as opposed to a constant temperature), the peak Nusselt number on the enclosure surface occurs near the spanwise walls and is about 20% higher than the peak Nusselt number at the cavity mid-plane. The temporal characteristics of 3D flows are also different from 2D results for Ra > 108. These results suggest that 3D simulations would be more appropriate for flows with Ra > 108.

Rayleigh scattering of a cylindrical sound wave by an infinite cylinder.

Science.gov (United States)

Baynes, Alexander B; Godin, Oleg A

2017-12-01

Rayleigh scattering, in which the wavelength is large compared to the scattering object, is usually studied assuming plane incident waves. However, full Green's functions are required in a number of problems, e.g., when a scatterer is located close to the ocean surface or the seafloor. This paper considers the Green's function of the two-dimensional problem that corresponds to scattering of a cylindrical wave by an infinite cylinder embedded in a homogeneous fluid. Soft, hard, and impedance cylinders are considered. Exact solutions of the problem involve infinite series of products of Bessel functions. Here, simple, closed-form asymptotic solutions are derived, which are valid for arbitrary source and receiver locations outside the cylinder as long as its diameter is small relative to the wavelength. The scattered wave is given by the sum of fields of three linear image sources. The viability of the image source method was anticipated from known solutions of classical electrostatic problems involving a conducting cylinder. The asymptotic acoustic Green's functions are employed to investigate reception of low-frequency sound by sensors mounted on cylindrical bodies.

A COMPUTATIONAL STUDY OF THE ACTUATION SPEED OF THE HYDRAULIC CYLINDER UNDER DIFFERENT PORTS’ SIZES AND CONFIGURATIONS

Directory of Open Access Journals (Sweden)

M. O. ABDALLA

2015-02-01

Full Text Available The discharged oil from hydraulic cylinder, during its operation, is highly restricted by the small sized outlets. As a result, a back pressure builds up and the piston motion, therefore, is slowed down; the system pump has to do additional work to overcome this hydraulic resistance so as to preserve the required speed. In this study the possibility of improvement of the actuation speed of the hydraulic cylinders was investigated and analysed. Both a four-port cylinder and a resized-ports cylinder were proposed as fast cylinders. FLUENT 6.3 was used for the simulation of the oil flow field of the hydraulic cylinders. Results showed that relation between discharge flow and the outlets diameters is best described by a power law having coefficients partially depending on the system pressure. It had also shown that for any given total outlet area, the actuation speed of the single outlet cylinders is always higher than that of the double outlets cylinders. In one case where the total outlet area is 3.93E-05m2, the actuation speed of the single outlet cylinder is 21% higher than that of the double outlets cylinder; whereas, when doubling the total outlet area the different is reduced to just 6% . Resizing the outlet for small ports was more efficient than using multi-outlets; while for a large ports it shows no significant difference to use either one outlet port or multi-outlets. Both the solutions of resizing or ports addition need special valve to be fit to the cylinder so that the cylinder could be effectively operated under the control of the proportional valve.

Testing of one-inch UF{sub 6} cylinder valves under simulated fire conditions

Energy Technology Data Exchange (ETDEWEB)

Elliott, P.G. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

1991-12-31

Accurate computational models which predict the behavior of UF{sub 6} cylinders exposed to fires are required to validate existing firefighting and emergency response procedures. Since the cylinder valve is a factor in the containment provided by the UF{sub 6} cylinder, its behavior under fire conditions has been a necessary assumption in the development of such models. Consequently, test data is needed to substantiate these assumptions. Several studies cited in this document provide data related to the behavior of a 1-inch UF{sub 6} cylinder valve in fire situations. To acquire additional data, a series of tests were conducted at the Paducah Gaseous Diffusion Plant (PGDP) under a unique set of test conditions. This document describes this testing and the resulting data.

Some integral representations and limits for (products of) the parabolic cylinder function

NARCIS (Netherlands)

Veestraeten, D.

2016-01-01

Recently, [Veestraeten D. On the inverse transform of Laplace transforms that contain (products of) the parabolic cylinder function. Integr Transf Spec F 2015;26:859-871] derived inverse Laplace transforms for Laplace transforms that contain products of two parabolic cylinder functions by exploiting

The Weight Loss Effect of Heated Inner Cylinder by Free Convection in Horizontal Cylindrical Enclosure

Science.gov (United States)

Sboev, I. O.; Kondrashov, A. N.; Rybkin, K. A.; Burkova, L. N.; Goncharov, M. M.

2018-03-01

The work presents results of numerical simulations of natural convection in cavity formed by the surfaces of two horizontal coaxial cylinders. The temperature of the outer cylinder is constant. The area between the cylinders is filled with an ideal incompressible fluid. The inner cylinder is set as the heater. The solution of the equations of thermal convection in a two-dimensional approximation performed by the software package ANSYS Fluent with finite volume method. The study compares the results of numerical simulation with several well-known theoretical and experimental results. The nature of interaction of the inner cylinder with a convection current created in the gap was observed. It was shown that the flux appeared around a heated cylinder affects the weight of the heat source and causes an additional lift force from the surrounding fluid. The various Rayleigh numbers (from 1.0 ṡ 103 to 1.5 ṡ 106) and fluid with different Prandtl number (from 0.5 to 1.0 ṡ 105) are considered.

Transient Vibrations of an Elastic Cylinder Inserted in the Elastic Medium

Directory of Open Access Journals (Sweden)

Sulym Heorgij

2016-06-01

Full Text Available Using method of Laguerre polynomials we have obtained the solution of the dynamic problem of the theory of elasticity for elastic cylinder inserted into massive body modeled as a space. The source of non-stationary processes in composite is high intensity force load of the inner surface of the cylinder. On the surface separation of materials of space and cylinder the conditions of ideal mechanical contact are satisfied. The solution is obtained as series of Laguerre polynomials, which coefficients are found from recurrent relations. The results of numerical analysis of transient stress-strain state in elastic space with cylindrical insertion might be used for the technological process of hydraulic fracturing during shale gas extraction.

Motion control of servo cylinder using neural network

International Nuclear Information System (INIS)

Hwang, Un Kyoo; Cho, Seung Ho

2004-01-01

In this paper, a neural network controller that can be implemented in parallel with a PD controller is suggested for motion control of a hydraulic servo cylinder. By applying a self-excited oscillation method, the system design parameters of open loop transfer function of servo cylinder system are identified. Based on system design parameters, the PD gains are determined for the desired closed loop characteristics. The neural network is incorporated with PD control in order to compensate the inherent nonlinearities of hydraulic servo system. As an application example, a motion control using PD-NN has been performed and proved its superior performance by comparing with that of a PD control

Measurement of functional cholinergic innervation in rat heart with a novel vesamicol receptor ligand

International Nuclear Information System (INIS)

Coffeen, Paul R.; Efange, S.M.N.; Haidet, George C.; McKnite, Scott; Langason, Rosemary B.; Khare, A.B.; Pennington, Jennifer; Lurie, Keith G.

1996-01-01

Regional differences in cholinergic activity in the cardiac conduction system have been difficult to study. We tested the utility of (+)-m-[ 125 I]iodobenzyl)trozamicol(+)-[ 125 I]MIBT), a novel radioligand that binds to the vesamicol receptor located on the synaptic vesicle in presynaptic cholinergic neurons, as a functional marker of cholinergic activity in the conduction system. The (+)-[ 125 I]MIBT was injected intravenously into four rats. Three hours later, the rats were killed and their hearts were frozen. Quantitative autoradiography was performed on 20-micron-thick sections that were subsequently stained for acetylcholinesterase to identify specific conduction-system elements. Marked similarities existed between (+)-[ 125 I]MIBT uptake and acetylcholinesterase-positive regions. Optical densitometric analysis of regional (+)-[ 125 I]MIBT uptake revealed significantly greater (+)-[ 125 I]MIBT binding (nCi/mg) in the atrioventricular node (AVN) and His bundle regions compared with other conduction and contractile elements (AVN: 3.43 ± 0.37; His bundle: 2.16 ± 0.30; right bundle branch: 0.95 ± 0.13; right atrium: 0.68 ± 0.05; right ventricle: 0.57 ± 0.03; and left ventricle: 0.57 ± 0.03; p 125 I]MIBT binds avidly to cholinergic nerve tissue innervating specific conduction-system elements. Thus, (+)-[ 125 I]MIBT may be a useful functional marker in studies on cholinergic innervation in the cardiac conduction system

Estimation of Individual Cylinder Air-Fuel Ratio in Gasoline Engine with Output Delay

Directory of Open Access Journals (Sweden)

Changhui Wang

2016-01-01

Full Text Available The estimation of the individual cylinder air-fuel ratio (AFR with a single universal exhaust gas oxygen (UEGO sensor installed in the exhaust pipe is an important issue for the cylinder-to-cylinder AFR balancing control, which can provide high-quality torque generation and reduce emissions in multicylinder engine. In this paper, the system dynamic for the gas in exhaust pipe including the gas mixing, gas transport, and sensor dynamics is described as an output delay system, and a new method using the output delay system observer is developed to estimate the individual cylinder AFR. With the AFR at confluence point augmented as a system state, an observer for the augmented discrete system with output delay is designed to estimate the AFR at confluence point. Using the gas mixing model, a method with the designed observer to estimate the individual cylinder AFR is presented. The validity of the proposed method is verified by the simulation results from a spark ignition gasoline engine from engine software enDYNA by Tesis.

The amplitude of fluid-induced vibration of cylinders in axial flow

Energy Technology Data Exchange (ETDEWEB)

Paidoussis, M. P.

1965-03-15

This report describes a new empirical expression of the amplitude of transverse vibration of cylindrical beams and clusters of cylinders in axial flow, for application to reactor fuel. The expression is based on reported experimental observations covering a variety of geometries, cylinder materials and types of support in water, superheated steam and two-phase mixture flows. (author)

The amplitude of fluid-induced vibration of cylinders in axial flow

International Nuclear Information System (INIS)

Paidoussis, M.P.

1965-03-01

This report describes a new empirical expression of the amplitude of transverse vibration of cylindrical beams and clusters of cylinders in axial flow, for application to reactor fuel. The expression is based on reported experimental observations covering a variety of geometries, cylinder materials and types of support in water, superheated steam and two-phase mixture flows. (author)

Surface Morphology Diagram for Cylinder-Forming Block Copolymer Thin Films

International Nuclear Information System (INIS)

Zhang, Xiaohua; Berry, Brian C.; Yager, Kevin G.; Kim, Sangcheol; Jones, Ronald L.; Satija, Sushil; Pickel, Deanna L.; Douglas, Jack F.; Karim, Alamgir

2008-01-01

We investigate the effect of annealing temperature (T), film thickness (hf) on the surface morphology of flow coated films of a cylinder forming block copolymer, poly (styrene-block-methyl methacrylate) (PS-b-PMMA). Surface morphology transitions from a perpendicular to a parallel cylinder orientation with respect to the substrate with increasing hf are observed in these model 'frustrated-interaction' films where the substrate interaction is preferential for one of the blocks (PMMA) and nearly neutral for the other interface (polymer-air). In these films a transition occurs from cylinders oriented parallel to the substrate to a mixed or 'hybrid' state where the two orientations coexist followed by a transition to cylinders oriented perpendicularly to the polymer-air interface for larger hf. The characteristic values of hf defining these surface morphological transitions depend on T and we construct a surface morphology diagram as a function of hf and T. The surface morphology diagram is found to depend on the method of film formation (flow coated versus spun cast films) so non-equilibrium effects evidently have a large effect on the surface pattern morphology. In particular, the residual solvent within the film (quantified by neutron reflectivity measurements) in the context of physics of glass-formation can have a large effect on the surface morphology diagram

Design of nested Halbach cylinder arrays for magnetic refrigeration applications

Energy Technology Data Exchange (ETDEWEB)

Trevizoli, Paulo V., E-mail: trevizoli@polo.ufsc.br; Lozano, Jaime A.; Peixer, Guilherme F.; Barbosa Jr, Jader R.

2015-12-01

We present an experimentally validated analytical procedure to design nested Halbach cylinder arrays for magnetic cooling applications. The procedure aims at maximizing the magnetic flux density variation in the core of the array for a given set of design parameters, namely the inner diameter of the internal magnet, the air gap between the magnet cylinders, the number of segments of each magnet and the remanent flux density of the Nd{sub 2}Fe{sub 14}B magnet grade. The design procedure was assisted and verified by 3-D numerical modeling using a commercial software package. An important aspect of the optimal design is to maintain an uniform axial distribution of the magnetic flux density in the region of the inner gap occupied by the active magnetocaloric regenerator. An optimal nested Halbach cylinder array was manufactured and experimentally evaluated for the magnetic flux density in the inner gap. The analytically calculated magnetic flux density variation agreed to within 5.6% with the experimental value for the center point of the magnet gap. - Highlights: • An analytical procedure to design nested Halbach cylinder arrays is proposed. • An optimal magnet configuration was built based on the analytical procedure. • The procedure was validated with 3D COMSOL simulations and experimental data.

Influence of plane bed on the force exerted on a cylinder oscillating in still water

Energy Technology Data Exchange (ETDEWEB)

Naeeni, S.T.O. [Tehran Univ., Dept. of Civil Engineering, Tehran (Iran); Narayanan, R. [Universiti Teknologi Malaysia, Faculty of Civil Engineering, Johor Bahru (Malaysia)

2005-12-01

The wall pressure field on a cylinder oscillating over a plane bed in still water is reported in this paper. Two gaps between the cylinder and the bed were considered. Pressures on the periphery of the cylinder were measured by a transducer and were found to be essentially repeatable from one cycle to the next. The forces determined from the pressure profiles compare well with those measured directly by a force transducer except significantly at Keulegan-Carpenter number of 15.0. The importance of the plane bed when it is stationary or moving with the cylinder is examined. The significance of the roughness of the bed with respect to the oscillatory forces exerted on the cylinder is also assessed. (Author)

Two dimensional numerical analysis of aerodynamic characteristics for rotating cylinder on concentrated air flow

Science.gov (United States)

Alias, M. S.; Rafie, A. S. Mohd; Marzuki, O. F.; Hamid, M. F. Abdul; Chia, C. C.

2017-12-01

Over the years, many studies have demonstrated the feasibility of the Magnus effect on spinning cylinder to improve lift production, which can be much higher than the traditional airfoil shape. With this characteristic, spinning cylinder might be used as a lifting device for short take-off distance aircraft or unmanned aerial vehicle (UAV). Nonetheless, there is still a gap in research to explain the use of spinning cylinder as a good lifting device. Computational method is used for this study to analyse the Magnus effect, in which two-dimensional finite element numerical analysis method is applied using ANSYS FLUENT software to examine the coefficients of lift and drag, and to investigate the flow field around the rotating cylinder surface body. Cylinder size of 30mm is chosen and several configurations in steady and concentrated air flows have been evaluated. All in all, it can be concluded that, with the right configuration of the concentrated air flow setup, the rotating cylinder can be used as a lifting device for very short take-off since it can produce very high coefficient of lift (2.5 times higher) compared with steady air flow configuration.

Nonlinear Fracture Mechanics and Plasticity of the Split Cylinder Test

DEFF Research Database (Denmark)

Olesen, John Forbes; Østergaard, Lennart; Stang, Henrik

2006-01-01

properties. This implies that the linear elastic interpretation of the ultimate splitting force in term of the uniaxial tensile strength of the material is only valid for special situations, e.g. for very large cylinders. Furthermore, the numerical analysis suggests that the split cylinder test is not well...... models are presented, a simple semi-analytical model based on analytical solutions for the crack propagation in a rectangular prismatic body, and a finite element model including plasticity in bulk material as well as crack propagation in interface elements. A numerical study applying these models...... demonstrates the influence of varying geometry or constitutive properties. For a split cylinder test in load control it is shown how the ultimate load is either plasticity dominated or fracture mechanics dominated. The transition between the two modes is related to changes in geometry or constitutive...

Optimized thick-wall cylinders by virtue of Poisson's ratio selection

International Nuclear Information System (INIS)

Whitty, J.P.M.; Henderson, B.; Francis, J.; Lloyd, N.

2011-01-01

The principal stress distributions in thick-wall cylinders due to variation in the Poisson's ratio are predicted using analytical and finite element methods. Analyses of appropriate brittle and ductile failure criteria show that under the isochoric pressure conditions investigated that auextic (i.e. those possessing a negative Poisson's ratio) materials act as stress concentrators; hence they are predicted to fail before their conventional (i.e. possessing a positive Poisson's ratio) material counterparts. The key finding of the work presented shows that for constrained thick-wall cylinders the maximum tensile principal stress can vanish at a particular Poisson's ratio and aspect ratio. This phenomenon is exploited in order to present an optimized design criterion for thick-wall cylinders. Moreover, via the use of a cogent finite element model, this criterion is also shown to be applicable for the design of micro-porous materials.

Effect of instantaneous rotational speed on the analysis of measured diesel engine cylinder pressure data

International Nuclear Information System (INIS)

Antonopoulos, Antonis K.; Hountalas, Dimitrios T.

2012-01-01

Highlights: ► The effect of in-cycle speed fluctuation on cylinder pressure measurement is investigated. ► A phasing error is introduced when sampling cylinder pressure at constant time intervals. ► The phasing error increases with the increase of engine load and decrease of engine speed. ► Measurement using constant sampling rate affects estimation of HRR, ignition angle etc. - Abstract: Diesel engine cylinder pressure measurements are widely used in field and lab applications to support among other control, monitoring and diagnostic applications. There are two methods to measure cylinder pressure, the use of a crank angle encoder, which guarantees pressure samples at fixed crank angles, and the use of constant time sampling rate. The last is frequently used due to its simplicity or because of practical restrictions. However, in order to perform thermodynamic calculations it is necessary to attribute a crank angle value to each measured pressure value. But if the in-cycle rotational speed fluctuates and this is neglected, an error will result in the values derived from the processing of the measured cylinder pressure. For this reason in the present work an experimental investigation is conducted on a single cylinder diesel test engine to identify the aforementioned problem. During the tests cylinder pressure and instantaneous speed were recorded using an accurate crank angle reference. These where then used to simulate the measurement of cylinder pressure digitized using a fixed time step. The comparison of the two cylinder pressure traces and the thermodynamic parameters derived from them, reveals the introduction of an error which depends on engine load and speed.

Classification of gap flow regimes in two side-by-side circular cylinders

CSIR Research Space (South Africa)

Atkins, M

2014-02-01

Full Text Available The behavior of the flow around two circular cylinders arranged in a side-by-side configuration strongly depends on the transverse center-to-center gap spacing ratio (T/D) where D is the cylinder diameter. Based on the observed wake structure [13...

The effects of axis ratio on laminar fluid flow around an elliptical cylinder

International Nuclear Information System (INIS)

Faruquee, Zakir; Ting, David S-K.; Fartaj, Amir; Barron, Ronald M.; Carriveau, Rupp

2007-01-01

An elliptical cylinder is a generic shape which represents a flat plate at its minor to major axis ratio (AR) limits of zero and infinity, and a circular cylinder at AR of unity. While incompressible flows over a streamwise flat plate (AR = 0), a cross-stream flat plate (AR = ∞), and a circular cylinder have been studied extensively, the role of AR on the detailed flow structure is still not well understood. Therefore, a numerical study was conducted to examine the flow field around an elliptical cylinder over a range of ARs from 0.3 to 1, with the major axis parallel to the free-stream, at a Reynolds number of 40 based on the hydraulic diameter. The control volume approach of FLUENT was used to solve the fluid flow equations, assuming the flow over the cylinder is unbounded, steady, incompressible and two-dimensional. It has been found that a pair of steady vortices forms when AR reaches a critical value of 0.34; below this value no vortices are formed behind the elliptical cylinder. Various wake parameters, drag coefficient, pressure and velocity distributions, have been characterized as functions of AR. The wake size and the drag coefficient are found to increase with the increase of AR. Quadratic correlations have been obtained to describe the relations of wake length and drag coefficient with axis ratio

Suppression of vortex-induced vibrations in a flexible cylinder with elastic splitter plates

Science.gov (United States)

Huera-Huarte, Francisco

2013-11-01

Suppression of vortex-induced vibrations (VIV) is a topic that has received a lot of attention due to its practical implications in engineering design. Experiments have been conducted in a recirculating free surface water channel, with a working section of dimensions 1 × 1.1 × 2.5 m. A cylinder model made of a spring and a plastic cover was used for the experiments. It was placed horizontally and fully submerged in the water channel's free stream, hanging from two submersible load cells arranged to measure the total drag force on the cylinder. The model had several white points painted on its surface, so its VIV motion was obtained by imaging it with two cameras synchronised with a strobe light. Image processing allowed to obtain the displacements along the length of the cylinder with sub-pixel accuracy. Digital Particle Image Velocimetry (DPIV) was also used to quantify the wake downstream the cylinder. A full set of experiments was made for reference purposes with a plain cylinder without suppressors, and for the same conditions, several passive suppression devices such as elastic splitter plates of different sizes and shapes, were installed on the cylinder. Passive VIV suppression with drag reduction was achieved with some of the configurations tested. Funding provided by the Spanish Ministry of Science through grant DPI2012-37904 is acknowledged.

Integrated two-cylinder liquid piston Stirling engine

Energy Technology Data Exchange (ETDEWEB)

Yang, Ning; Rickard, Robert; Pluckter, Kevin; Sulchek, Todd, E-mail: todd.sulchek@me.gatech.edu [George W. Woodruff School of Mechanical Engineering and Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

2014-10-06

Heat engines utilizing the Stirling cycle may run on low temperature differentials with the capacity to function at high efficiency due to their near-reversible operation. However, current approaches to building Stirling engines are laborious and costly. Typically the components are assembled by hand and additional components require a corresponding increase in manufacturing complexity, akin to electronics before the integrated circuit. We present a simple and integrated approach to fabricating Stirling engines with precisely designed cylinders. We utilize computer aided design and one-step, planar machining to form all components of the engine. The engine utilizes liquid pistons and displacers to harness useful work from heat absorption and rejection. As a proof of principle of the integrated design, a two-cylinder engine is produced and characterized and liquid pumping is demonstrated.

Integrated two-cylinder liquid piston Stirling engine

International Nuclear Information System (INIS)

Yang, Ning; Rickard, Robert; Pluckter, Kevin; Sulchek, Todd

2014-01-01

Heat engines utilizing the Stirling cycle may run on low temperature differentials with the capacity to function at high efficiency due to their near-reversible operation. However, current approaches to building Stirling engines are laborious and costly. Typically the components are assembled by hand and additional components require a corresponding increase in manufacturing complexity, akin to electronics before the integrated circuit. We present a simple and integrated approach to fabricating Stirling engines with precisely designed cylinders. We utilize computer aided design and one-step, planar machining to form all components of the engine. The engine utilizes liquid pistons and displacers to harness useful work from heat absorption and rejection. As a proof of principle of the integrated design, a two-cylinder engine is produced and characterized and liquid pumping is demonstrated.

Integrated two-cylinder liquid piston Stirling engine

Science.gov (United States)

Yang, Ning; Rickard, Robert; Pluckter, Kevin; Sulchek, Todd

2014-10-01

Heat engines utilizing the Stirling cycle may run on low temperature differentials with the capacity to function at high efficiency due to their near-reversible operation. However, current approaches to building Stirling engines are laborious and costly. Typically the components are assembled by hand and additional components require a corresponding increase in manufacturing complexity, akin to electronics before the integrated circuit. We present a simple and integrated approach to fabricating Stirling engines with precisely designed cylinders. We utilize computer aided design and one-step, planar machining to form all components of the engine. The engine utilizes liquid pistons and displacers to harness useful work from heat absorption and rejection. As a proof of principle of the integrated design, a two-cylinder engine is produced and characterized and liquid pumping is demonstrated.

Magnetic moment jumps in flat and nanopatterned Nb thin-walled cylinders

Energy Technology Data Exchange (ETDEWEB)

Tsindlekht, M.I., E-mail: mtsindl@vms.huji.ac.il [The Racah Institute of Physics, The Hebrew University of Jerusalem, 91904 Jerusalem (Israel); Genkin, V.M.; Felner, I.; Zeides, F.; Katz, N. [The Racah Institute of Physics, The Hebrew University of Jerusalem, 91904 Jerusalem (Israel); Gazi, Š.; Chromik, Š. [The Institute of Electrical Engineering SAS, Dúbravská cesta 9, 84104 Bratislava (Slovakia); Dobrovolskiy, O.V. [Physikalisches Institut, Goethe University, 60438 Frankfurt am Main (Germany); Physics Department, V. Karazin Kharkiv National University, 61077 Kharkiv (Ukraine); Sachser, R.; Huth, M. [Physikalisches Institut, Goethe University, 60438 Frankfurt am Main (Germany)

2017-02-15

Highlights: • Magnetization curves of as-prepared and patterned thin-walled cylinders were measured in magnetic fields applied parallel to cylinders axis. • Magnetic moment jumps were observed in magnetic fields lower and above Hc1. • Critical current density in isthmus between two antidots is higher than in a film itself. - Abstract: Penetration of magnetic flux into hollow superconducting cylinders is investigated by magnetic moment measurements. The magnetization curves of a flat and a nanopatterned thin-walled superconducting Nb cylinders with a rectangular cross section are reported for the axial field geometry. In the nanopatterned sample, a row of micron-sized antidots (holes) was milled in the film along the cylinder axis. Magnetic moment jumps are observed for both samples at low temperatures for magnetic fields not only above H{sub c1}, but also in fields lower than H{sub c1}, i. e., in the vortex-free regime. The positions of the jumps are not reproducible and they change from one experiment to another, resembling vortex lattice instabilities usually observed for magnetic fields larger than H{sub c1}. At temperatures above 0.66T{sub c} and 0.78T{sub c} the magnetization curves become smooth for the patterned and the as-prepared sample, respectively. The magnetization curve of a reference flat Nb film in the parallel field geometry does not exhibit jumps in the entire range of accessible temperatures.

NK-1 Removable Cryogenic Shroud (A Study of the Bimba Pneumatic Cylinder)

International Nuclear Information System (INIS)

Anderson, K.; Stefanescu, D.

2003-01-01

The Mark 1 Cryostat requires a cryogenic shroud that must be retracted immediately before firing the NIF laser. This paper evaluates a pneumatic cylinder that has been chosen to open and close the shroud. After a variety of motion control and vacuum compatibility experiments, we concluded that the Bimba feedback control cylinder may be used to retract the shroud with certain modifications to its control system and additional rod seals. The Mark I Cryostat is a system that allows fielding of a wide range of targets on the National Ignition Facility (NIF). The purpose is to have a system with the capability of controlling the target temperature between ∼10 and 300 K. While in the Target Chamber, a shroud must cover the cooled targets. This shroud allows the cold target to be shielded from condensable residual gasses in the target chamber. The removable shroud may be cooled to 80 K to provide a radiant shield for the target from the room temperature target chamber. The shroud must remain over the target until approximately one second before shot time, and then retract on command, without inducing vibration into the target. An actuation system design, which removes the shroud, is constrained by the size limitations of the MK-1, the need to build from low-activation materials, the need to operate in a vacuum, and the need for high reliability. The scheme for retracting the shroud that they investigated was a pressurized air cylinder. The pneumatic cylinder tested in our experiments was built by the Bimba Manufacturing Company. We thought it would be suitable for shroud retraction because its manufacturer claimed that its motion was smooth, highly accurate, controllable and the appropriate size for our needs. The pneumatic cylinder moves a piston by changing the gas pressure in the two sections of the cylinder on either side of the piston. The cylinder also uses the piston as a voltage potentiometer to determine the current position of the piston. This voltage is then

Flexural vibrations of finite composite poroelastic cylinders

Indian Academy of Sciences (India)

We know from daily experience that many man-made structures consist of ..... The physical parameters of these composite cylinders following Eq. (38) are given in ... Titanium implants remain virtually unchanged in appearance, which offers ...

Three-dimensional diffraction of a thin metallic cylinder illuminated in conical incidence: application to diameter estimation

International Nuclear Information System (INIS)

Miguel Sanchez-Brea, Luis; Javier Salgado-Remacha, Francisco

2008-01-01

We present a model to determine the far-field diffraction pattern of a metallic cylinder of infinite length when it is illuminated in oblique incidence. This model is based on the Helmholtz-Kirchhoff integral using the Beckmann conditions for reflection. It considers the three-dimensional nature of the diffracting object as well as the material of which the cylinder is made. This model shows that the diffraction orders are placed in a cone of light. The amplitude at the far field can be divided into three terms: the first term accounts for Babinet's principle, that is, the contribution of the cylinder projection; the second term accounts for the three dimensionality of the cylinder; and the third term accounts for the material of which the cylinder is made. This model is applied to the diameter estimation of the cylinder. Since the amplitude of the Babinet contribution is much larger than the light reflected by the surface, the cylinder diameter can be obtained in a simple way. With this approximation, the locations of the diffraction minima do not vary when the cylinder is inclined. On the other hand, when the reflected light is considered the location of the minima and, hence, the estimation of the diameter, varies. Also, a modification of the diffraction minima is produced by the material of which the cylinder is made. Experimental results are also obtained that corroborate the theoretical approach

Self-contact for rods on cylinders

NARCIS (Netherlands)

G.H.M. van der Heijden; M.A. Peletier (Mark); R. Planqué (Robert)

2004-01-01

textabstractWe study self-contact phenomena in elastic rods that are constrained to lie on a cylinder. By choosing a particular set of variables to describe the rod centerline the variational setting is made particularly simple: the strain energy is a second-order functional of a single scalar

Boundary value problems of the circular cylinders in the strain-gradient theory of linear elasticity

International Nuclear Information System (INIS)

Kao, B.G.

1979-11-01

Three boundary value problems in the strain-gradient theory of linear elasticity are solved for circular cylinders. They are the twisting of circular cylinder, uniformly pressuring of concentric circular cylinder, and pure-bending of simply connected cylinder. The comparisons of these solutions with the solutions in classical elasticity and in couple-stress theory reveal the differences in the stress fields as well as the apparent stress fields due to the influences of the strain-gradient. These aspects of the strain-gradient theory could be important in modeling the failure behavior of structural materials

Innervation status in chronic vocal fold paralysis and implications for laryngeal reinnervation.

Science.gov (United States)

Lin, R Jun; Smith, Libby J; Munin, Michael C; Sridharan, Shaum; Rosen, Clark A

2018-01-22

Treatment options for symptomatic unilateral vocal fold paralysis (VFP) include vocal fold augmentation, laryngeal framework surgery, and laryngeal reinnervation. Laryngeal reinnervation (LR) has been suggested to provide "tone" to the paralyzed VF. This implies a loss of tone as a result of denervation without reinnervation. We performed laryngeal electromyography (LEMG) in patients with chronic VFP to understand the innervation status associated with a chronically paralyzed vocal fold. Retrospective review of LEMG data in adult patients with chronic VFP from January 2009 to December 2014. LEMG was performed at least 6 months after-onset of VFP. Qualitative LEMG, quantitative LEMG, and adductory synkinesis testing were performed, and the parameters were collected. Twenty-seven vocal folds were studied (23 unilateral VFP and 2 bilateral VFP). Average age was 59 ± 17 years. The median duration from recurrent laryngeal nerve injury to LEMG was 8.5 months (range 6-90 months). The majority of patients, 24 of 27 (89%), had motor unit potentials during phonation tasks on LEMG, and only 3 of 27 (11%) patients were electrically silent. Quantitative LEMG showed 287.8 mean turns per second (normal ≥ 400). Motor unit configuration was normal in 12 of 27 (44%), polyphasic in 12 of 27 (44%), and absent in the electrically silent patients. Adductory synkinesis was found in 6 of 20 (30%) patients. Chronic vocal fold paralysis is infrequently associated with absent motor-unit recruitment, indicating some degree of preserved innervation and/or reinnervation in these patients. LEMG should be part of the routine workup for chronic VFP prior to consideration of LR. 4. Laryngoscope, 2018. © 2018 The American Laryngological, Rhinological and Otological Society, Inc.

Function and Innervation of the Locus Ceruleus in a Macaque Model of Functional Hypothalamic Amenorrhea

OpenAIRE

Bethea, Cynthia L; Kim, Aaron; Cameron, Judy L

2012-01-01

A body of knowledge implicates an increase in output from the locus ceruleus (LC) during stress. We questioned the innervation and function of the LC in our macaque model of Functional Hypothalamic Amenorrhea, also known as Stress-Induced Amenorrhea. Cohorts of macaques were initially characterized as highly stress resilient (HSR) or stress-sensitive (SS) based upon the presence or absence of ovulation during a protocol involving 2 menstrual cycles with psychosocial and metabolic stress. Afte...

A comparative analysis on the shed vortices from the wake of finned, foam-wrapped cylinders

Energy Technology Data Exchange (ETDEWEB)

Khashehchi, Morteza [Department of Agro-Technology, College of Aburaihan, University of Tehran, Tehran (Iran, Islamic Republic of); Ashtiani Abdi, Iman; Hooman, Kamel, E-mail: m.khashehchi@ut.ac.ir [School of Mechanical and mining Engineering, University of Queensland, Brisbane (Australia)

2017-08-15

The wake characteristics behind a finned and a foam-wrapped circular cylinder has been compared in a study (Khashehchi et al 2014 Exp. Therm. Fluid Sci. 52 328–38) done by the Authors. In this paper, the shed vortices from the wake of the same cylinders have been studied. Shedding in a bluff body has an important effect on increasing the pressure drop downstream of the object. Here, we have used particle image velocimetry to investigate the detached vortices from the wake behind a foam-wrapped and a finned cylinder. The standard case of cross-flow over a bare cylinder, i.e. no surface extension, has also been tested as a benchmark. The experiments have been performed for Reynolds numbers 2000 based on the mean air velocity and the cylinder’s outer diameter. To identify the features of each aforementioned case, linear stochastic estimation has been applied to the velocity fields. Results show that unlike the fin, adding foam to the cylinder surface increases the size of detached vortices and amplifies the core strength. Moreover, foam-wrapped cylinder in contrast to the finned one produces strong three-dimensionality. Interestingly, finned cylinder’s results show less three-dimensionality compared to the bare cylinder. (paper)

76 FR 33239 - High Pressure Steel Cylinders From the People's Republic of China; Initiation of Countervailing...

Science.gov (United States)

2011-06-08

... DEPARTMENT OF COMMERCE International Trade Administration [C-570-978] High Pressure Steel... countervailing duty (``CVD'') petition concerning imports of high pressure steel cylinders (``steel cylinders... of Antidumping Duties and Countervailing Duties on High Pressure Steel Cylinders from the People's...

Life Prediction on a T700 Carbon Fiber Reinforced Cylinder with Limited Accelerated Life Testing Data

OpenAIRE

Ma Xiaobing; Zhang Yongbo

2015-01-01

An accelerated life testing investigation was conducted on a composite cylinder that consists of aluminum alloy and T700 carbon fiber. The ultimate failure stress predictions of cylinders were obtained by the mixing rule and verified by the blasting static pressure method. Based on the stress prediction of cylinder under working conditions, the constant stress accelerated life test of the cylinder was designed. However, the failure data cannot be sufficiently obtained by the accelerated life ...

Experimental investigation of turbulent flow past four grooved and smooth cylinders in an in-line square arrangement

Directory of Open Access Journals (Sweden)

Ladjedel O.

2015-01-01

Full Text Available An experimental study of turbulent flow past four cylinders in square arrangement with a space ratio of (T/D = P/D = 2.88 is performed. The investigation focuses on effects of Reynolds number and the shape of cylinders on the force and pressure coefficients of the cylinders. Two cases are investigated: four smooth cylinders (case1 and four grooved cylinders (case2. The cylinders are equipped with two grooves placed on the external surface at 90° and 270° degrees. The pressure distributions along the tubes (22 circumferential pressure taping were determined for a variation of the azimuthal angle from 0 to 360deg. The drag and lift forces are measured using the TE 44 balance. The results show a bistable flow often exists behind the downstream cylinders is observed. By rising the Reynolds number the pressure coefficient increases in the absolute value.