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Sample records for annulus closure technology

  1. ANNULUS CLOSURE TECHNOLOGY DEVELOPMENT INSPECTION/SALT DEPOSIT CLEANING MAGNETIC WALL CRAWLER

    Energy Technology Data Exchange (ETDEWEB)

    Minichan, R; Russell Eibling, R; James Elder, J; Kevin Kane, K; Daniel Krementz, D; Rodney Vandekamp, R; Nicholas Vrettos, N

    2008-06-01

    The Liquid Waste Technology Development organization is investigating technologies to support closure of radioactive waste tanks at the Savannah River Site (SRS). Tank closure includes removal of the wastes that have propagated to the tank annulus. Although amounts and types of residual waste materials in the annuli of SRS tanks vary, simple salt deposits are predominant on tanks with known leak sites. This task focused on developing and demonstrating a technology to inspect and spot clean salt deposits from the outer primary tank wall located in the annulus of an SRS Type I tank. The Robotics, Remote and Specialty Equipment (RRSE) and Materials Science and Technology (MS&T) Sections of the Savannah River National Laboratory (SRNL) collaborated to modify and equip a Force Institute magnetic wall crawler with the tools necessary to demonstrate the inspection and spot cleaning in a mock-up of a Type I tank annulus. A remote control camera arm and cleaning head were developed, fabricated and mounted on the crawler. The crawler was then tested and demonstrated on a salt simulant also developed in this task. The demonstration showed that the camera is capable of being deployed in all specified locations and provided the views needed for the planned inspection. It also showed that the salt simulant readily dissolves with water. The crawler features two different techniques for delivering water to dissolve the salt deposits. Both water spay nozzles were able to dissolve the simulated salt, one is more controllable and the other delivers a larger water volume. The cleaning head also includes a rotary brush to mechanically remove the simulated salt nodules in the event insoluble material is encountered. The rotary brush proved to be effective in removing the salt nodules, although some fine tuning may be required to achieve the best results. This report describes the design process for developing technology to add features to a commercial wall crawler and the results of the

  2. An annulus fibrosus closure device based on a biodegradable shape-memory polymer network.

    Science.gov (United States)

    Sharifi, Shahriar; van Kooten, Theo G; Kranenburg, Hendrik-Jan C; Meij, Björn P; Behl, Marc; Lendlein, Andreas; Grijpma, Dirk W

    2013-11-01

    Injuries to the intervertebral disc caused by degeneration or trauma often lead to tearing of the annulus fibrosus (AF) and extrusion of the nucleus pulposus (NP). This can compress nerves and cause lower back pain. In this study, the characteristics of poly(D,L-lactide-co-trimethylene carbonate) networks with shape-memory properties have been evaluated in order to prepare biodegradable AF closure devices that can be implanted minimally invasively. Four different macromers with (D,L-lactide) to trimethylene carbonate (DLLA:TMC) molar ratios of 80:20, 70:30, 60:40 and 40:60 with terminal methacrylate groups and molecular weights of approximately 30 kg mol(-1) were used to prepare the networks by photo-crosslinking. The mechanical properties of the samples and their shape-memory properties were determined at temperatures of 0 °C and 40 °C by tensile tests- and cyclic, thermo-mechanical measurements. At 40 °C all networks showed rubber-like behavior and were flexible with elastic modulus values of 1.7-2.5 MPa, which is in the range of the modulus values of human annulus fibrosus tissue. The shape-memory characteristics of the networks were excellent with values of the shape-fixity and the shape-recovery ratio higher than 98 and 95%, respectively. The switching temperatures were between 10 and 39 °C. In vitro culture and qualitative immunocytochemistry of human annulus fibrosus cells on shape-memory films with DLLA:TMC molar ratios of 60:40 showed very good ability of the networks to support the adhesion and growth of human AF cells. When the polymer network films were coated by adsorption of fibronectin, cell attachment, cell spreading, and extracellular matrix production was further improved. Annulus fibrosus closure devices were prepared from these AF cell-compatible materials by photo-polymerizing the reactive precursors in a mold. Insertion of the multifunctional implant in the disc of a cadaveric canine spine showed that these shape-memory devices could be

  3. An annulus fibrosus closure device based on a biodegradable shape-memory polymer network

    NARCIS (Netherlands)

    Sharifi, Shahriar; van Kooten, Theo G.; Kranenburg, Hendrik-Jan C.; Meij, Bjorn P.; Behl, Marc; Lendlein, Andreas; Grijpma, Dirk W.

    2013-01-01

    Injuries to the intervertebral disc caused by degeneration or trauma often lead to tearing of the annulus fibrosus (AF) and extrusion of the nucleus pulposus (NP). This can compress nerves and cause lower back pain. In this study, the characteristics of poly(D,L-lactide-co-trimethylene carbonate) ne

  4. Primary limited lumbar discectomy with an annulus closure device: one-year clinical and radiographic results from a prospective, multi-center study.

    Science.gov (United States)

    Lequin, Michiel B; Barth, Martin; Thomė, Claudius; Bouma, Gerrit J

    2012-12-01

    Discectomy as a treatment for herniated lumbar discs results in outcomes after surgery that are not uniformly positive. Surgeons face the dilemma between limited nucleus removal which is associated with a higher risk of recurrence, or more aggressive nucleus removal which may lead to disc height loss and persistent back-pain. annulus closure devices may allow for the benefits of limited nucleus removal without the increased risk of recurrence. This is an interim report of an ongoing 24-month post-marketing study of the Barricaid® annulus closure device, consisting of a flexible polymer mesh that blocks the defect, held in place by a titanium bone anchor. We prospectively enrolled 45 patients at four hospitals, and implanted the Barricaid® after a limited discectomy. annulus defect size and volume of removed nucleus were recorded. Reherniations were reported, pain and function were monitored and imaging was performed at regular intervals during 24 months of follow-up. At 12 months postsurgery, pain and function were significantly improved, comparing favorably to reported results from limited discectomy. Disc height has been well maintained. One reherniation has occurred (2.4%), which was associated with a misplaced device. No device fracture, subsidence or migration has been observed. The use of an annulus closure device may provide a reduction in reherniation rate for lumbar discectomy patients with large annulus defects who are at the greatest risk of recurrence. Using such a device should provide the surgeon increased confidence in minimizing nucleus removal, which, in turn, may preserve disc height and biomechanics, reducing degeneration and associated poor clinical outcomes in the long-term. A randomized multicenter study evaluating limited discectomy with and without the Barricaid® is currently underway, and will provide a higher level of evidence.

  5. The dura gide to annulus fibrosus closurement%人工生物膜修复椎间盘纤维环的研究

    Institute of Scientific and Technical Information of China (English)

    丁文元; 申勇; 郭金库; 贺延雷; 吴海龙; 曹来震; 李鹏飞

    2010-01-01

    Objective To evaluate the repair efficiency of dura gide to intervertebral disc annulus fibrosus defect. Methods Totallly 24 lumbar intervertebral discs of 8 sheep underwent one of the following 3 methods: (1) the disc annulus fibrosus was exposed through retroperitoneal approach without any farther procedure; (2) the disc annulus fibrosus was exposed and a defect was made, and then the defect was repaired with dura gide; (3) the disc annulus fibrosus was exposed and a defect was made as control. At the 12th week after surgery, 15 discs of 5 sheep underwent pressure-volume testing to assess the competency of the annulus fibrosus. MRI images and decalcified histology were performed on the remaining 9 discs of 3sheep. Results At the 12th week, the mean max-pressure in expose-only, excise-only and dura gide-reparied group was (4. 92 ±0. 17), (2. 48 ±0.39) and (3.76 ± 1.56) MPa, respectively. Both the competency in excised-only and dura gide-repaired groups was lower than in exposed-only group. The competency in dura gide-repaired groups was higher than in excise-only group ( P < 0. 05 ). MRI images and histology indicated that dura gide-repaired specimens were integrated well with the disc annulus fibrosus collagen.Conclusion There was a repair efficiency of dura gide to intervertebral disc annulus fibrosus defect. The mean competency recovery rate was 76.4%.%目的 用不同方法处理椎间盘纤维环,观察人工生物膜对椎间盘纤维环缺损的修复作用.方法 成年山羊8只,雌雄各4只,对每只羊的腰椎(腰2/3、腰3/4、腰4/5)椎间盘纤维环进行随机处理,处理方法包括:(1)暴露出椎间盘纤维环,不作任何处理;(2)暴露出椎间盘纤维环后,将其切开,用人下生物膜填充缺口;(3)暴露出椎间盘纤维环,尖刀将其切开,作为对照组.12周后,通过生物力学测试、核磁共振(MRI)及脱钙病理切片染色观察椎间盘纤维环的修复效果.结果 12周后,测试纤维环承受最

  6. Closure

    NARCIS (Netherlands)

    Stigter, C.J.

    1988-01-01

    At least an easier task than I have carried out the previous hour when we discussed the preliminary conclusions and recommendations has, as a compensation I guess, been given to me as well. To say a few words as a closure of this symposium. The beginning of such a series of closing statements is mos

  7. Cervical spine annulus vacuum.

    Science.gov (United States)

    Bohrer, S P; Chen, Y M

    1988-01-01

    Thirty-eight annulus vacuums in 27 patients were analyzed with regard to location, configuration, and associated vertebral abnormalities such as degenerative changes, absent and compressed anterosuperior vertebral body corners, and annulus calcification. It is concluded that most annulus vacuums are a degenerative phenomenon at the attachment of the annulus to bone. These vacuums may be associated with other degenerative changes such as osteophytes and annulus calcification. Vacuums have a strong association with compressed anterosuperior corners. These deformed corners are thought to be early osteophytes and may be related to previous trauma, a vertebra with an absent corner, and/or normal motion. Small annulus vacuums adjacent to vertebral corners with a normal appearance are more likely to result from acute trauma.

  8. Cervical spine annulus vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Bohrer, S.P.; Chen, Y.M.

    1988-07-01

    Thirty-eight annulus vacuums in 27 patients were analyzed with regard to location, configuration, and associated vertebral abnormalities such as degenerative changes, absent and compressed anterosuperior vertebral body corners, and annulus calcification. It is concluded that most annulus vacuums are a degenerative phenomenon at the attachment of the annulus to bone. These vacuums may be associated with other degenerative changes such as osteophytes and annulus calcification. Vacuums have a strong association with compressed anterosuperior corners. These deformed corners are thought to be early osteophytes and may be related to previous trauma, a vertebra with an absent corner, and/or normal motion. Small annulus vacuums adjacent to vertebral corners with a normal appearance are more likely to result from acute trauma.

  9. Advanced Technologies to Improve Closure of Life Support Systems

    Science.gov (United States)

    Barta, Daniel J.

    2016-01-01

    As NASA looks beyond the International Space Station toward long-duration, deep space missions away from Earth, the current practice of supplying consumables and spares will not be practical nor affordable. New approaches are sought for life support and habitation systems that will reduce dependency on Earth and increase mission sustainability. To reduce launch mass, further closure of Environmental Control and Life Support Systems (ECLSS) beyond the current capability of the ISS will be required. Areas of particular interest include achieving higher degrees of recycling within Atmosphere Revitalization, Water Recovery and Waste Management Systems. NASA is currently investigating advanced carbon dioxide reduction processes that surpass the level of oxygen recovery available from the Sabatier Carbon Dioxide Reduction Assembly (CRA) on the ISS. Candidate technologies will potentially improve the recovery of oxygen from about 50% (for the CRA) to as much as 100% for technologies who's end product is solid carbon. Improving the efficiency of water recycling and recovery can be achieved by the addition of advanced technologies to recover water from brines and solid wastes. Bioregenerative technologies may be utilized for water reclaimation and also for the production of food. Use of higher plants will simultaneously benefit atmosphere revitalization and water recovery through photosynthesis and transpiration. The level at which bioregenerative technologies are utilized will depend on their comparative requirements for spacecraft resources including mass, power, volume, heat rejection, crew time and reliability. Planetary protection requirements will need to be considered for missions to other solar system bodies.

  10. Functional myelographic differentiation of lumbar bulging annulus

    Energy Technology Data Exchange (ETDEWEB)

    Park, Choong Ki; Kim, Hong Kil; Park, Sang Gyu; Lee, Young Jung; Yoon, Jong Sup [Hallym University College of Medicine, Seoul (Korea, Republic of)

    1988-08-15

    Herniated disk and bulging annulus are the major causes of lower back pain. It is necessary to differentiate bulging annulus from herniated disk because of their different methods of treatment. Myelography is one of the useful diagnostic methods for disk diseases even though advanced diagnostic modalities such as CT and MRI are more accurate. Functional myelography is not a new technology expect for two additional views, flexion and extension, are obtained with conventional myelography. Differentiation between bulging annulus and herniated disk by conventional myelography is based on the extent and multiplicity of extradural deformity of the contrast filled dural sac and neural sleeve as well as the changes of nerve root. There is no previous report about differential points between bulging annulus and herniated disk according to functional myelography. It is the purpose of this study to find any additional differential points on functional myelography between bulging annulus and herniated disk over convectional myelography. Authors analysed functional myelographic findings of 152 cases from July 1986 to July 1987. Among them, 22 cases who had been suffered from cervical abnormality or vague lower back pain were diagnosed as normal by myelography, and 30 cases of L4-5 herniated disk and 21 cases of L4-5 bulging annulus which had been finally diagnosed by operation were studied. The results were as follows. 1. In normal group, anterior epidural space was gradually widened from the upper lumbar vertebra downward. And anterior epidural space was more sidened at the disk level in extension view than in flexion except for L5-S1 lever. 2. In bulging annulus group, the shape of anterior epidural space in flexion state was as similar as normal. Anoterior epidural space in extension state was more sidened at the buldging annulus than normal, but lesser than herniated disk. 3. In herniated disk group, widening of anterior epidural space at the herniated disk level was

  11. A combined biomaterial and cellular approach for annulus fibrosus rupture repair

    NARCIS (Netherlands)

    Pirvu, Tatiana; Blanquer, Sebastien B. G.; Benneker, Lorin M.; Grijpma, Dirk W.; Richards, Robert G.; Alini, Mauro; Eglin, David; Grad, Sibylle; Li, Zhen

    2015-01-01

    Recurrent intervertebral disc (IVD) herniation and degenerative disc disease have been identified as the most important factors contributing to persistent pain and disability after surgical discectomy. An annulus fibrosus (AF) closure device that provides immediate closure of the AF rupture, restore

  12. Ultrasonic defect detection and size approximation using thin annulus probes

    Energy Technology Data Exchange (ETDEWEB)

    Light, G.M.; Fisher, J.L.; Tennis, R.F.; Stolte, J.S.; Hendrix, G.J. [Southwest Research Inst., San Antonio, TX (United States)

    1994-12-31

    Concern has been generated recently about the capabilities of performing nondestructive evaluation (NDE) of the closure head penetrations in nuclear-reactor pressure vessels (PV). These penetrations, primarily for instrumentation and control rod drive mechanisms (CRDMs), are usually thick-walled Inconel tubes, shrink-fitted into the steel closure head. The penetrations are then welded between the outside surface of the penetration and inside surface of the closure head. Stress corrosion cracks initiating at the inner surface of the penetration have been reported at several plants. Through wall cracks in the CRDM penetration or CRDM weld could lead to loss of PV coolant. The penetration presents a complex geometry for conventional NDE techniques. A thermal sleeve, through which pass the mechanical linkages for control-rod operation, is inserted into the penetration so that only a small annulus (nominally 3 mm) exists between the thermal sleeve and inside surface of the penetration. SwRI has developed and evaluated ultrasonic techniques for sizing defects in this area. Long, thin probes were designed to fit into the annulus to carry irrigated ultrasonic transducers into the region of interest. The probes were used to detect cracks in the penetration and to estimate remaining wall thickness.

  13. The Annulus Property of Simple Holomorphic Discs

    CERN Document Server

    Zehmisch, Kai

    2010-01-01

    We show that any simple holomorphic disc admits the annulus property, i.e., each interior point is surrounded by an arbitrary small annulus consisting entirely of injective points. As an application we show that interior singularities of holomorphic discs can be resolved after slight perturbation of the involved almost complex structure. Moreover, for boundary points the analogue notion, the half-annulus property, is introduced and studied in detail.

  14. The annulus property of simple holomorphic discs

    OpenAIRE

    Zehmisch, Kai

    2013-01-01

    We show that any simple holomorphic disc admits the annulus property, i.e., each interior point is surrounded by an arbitrary small annulus consisting entirely of injective points. As an application we show that interior singularities of holomorphic discs can be resolved after slight perturbation of the almost complex structure. Moreover, for boundary points the analogue notion, the half-annulus property, is introduced and studied in detail.

  15. Closure phase and lucky imaging.

    Science.gov (United States)

    Rhodes, William T

    2009-01-01

    Since its introduction by Jennison in 1958, the closure-phase method for removing the effects of electrical path-length errors in radio astronomy and of atmospheric turbulence in optical astronomy has been based on the non-redundant-spacing triple interferometer. It is shown that through application of lucky imaging concepts it is possible to relax this condition, making closure-phase methods possible with redundantly spaced interferometer configurations and thereby widening their range of application. In particular, a quadruple-interferometer can, under lucky imaging conditions, be treated as though it were a triple interferometer. The slit-annulus aperture is investigated as a special case.

  16. Annulus electromagnetic stirring for preparing semisolid A357 aluminum alloy slurry

    Institute of Scientific and Technical Information of China (English)

    BAI Yue-long; XU Jun; ZHANG Zhi-feng; SHI Li-kai

    2009-01-01

    The effects of pouring temperature and annulus gap width on the microstructure of the semi-solid A357 aluminum alloy slurry prepared by annulus electromagnetic stirring(AEMS) technology were investigated. The results show that low pouring temperature and narrow annulus gap are advantageous to obtaining the small spherical primary α(Al) phase. The lower the pouring temperature is and the smaller the annulus gap width is, the more uniform, the smaller and the more spherical the microstructure is. The microstructures obtained by the ordinary electromagnetic stirring and AEMS were compared. The results indicate that the primary α(Al) particles are globular, small and distribute homogeneously in the slurry obtained by AEMS. But in the slurry obtained by the ordinary electromagnetic stirring, the primary α(Al) particles are small dendrites in the edge of the slurry and they are large and rosette-like or dendritic in the inner of the slurry.

  17. Left Atrial Appendage Closure Device With Delivery System: A Health Technology Assessment

    Science.gov (United States)

    Nevis, Immaculate; Falk, Lindsey; Wells, David; Higgins, Caroline

    2017-01-01

    Background Atrial fibrillation is a common cardiac arrhythmia, and 15% to 20% of those who have experienced stroke have atrial fibrillation. Treatment options to prevent stroke in people with atrial fibrillation include pharmacological agents such as novel oral anticoagulants or nonpharmacological devices such as the left atrial appendage closure device with delivery system (LAAC device). The objectives of this health technology assessment were to assess the clinical effectiveness and cost-effectiveness of the LAAC device versus novel oral anticoagulants in patients without contraindications to oral anticoagulants and versus antiplatelet agents in patients with contraindications to oral anticoagulants. Methods We performed a systematic review and network meta-analysis. We also conducted an economic literature review, economic evaluation, and budget impact analysis to assess the cost-effectiveness and budget impact of the LAAC device compared with novel oral anticoagulants and oral antiplatelet agents (e.g., aspirin). We also spoke with patients to better understand their preferences, perspectives, and values. Results Seven randomized controlled studies met the inclusion criteria for indirect comparison. Five studies assessed the effectiveness of novel oral anticoagulants versus warfarin, and two studies compared the LAAC device with warfarin. No studies were identified that compared the LAAC device with aspirin in patients in whom oral anticoagulants were contraindicated. Using the random effects model, we found that the LAAC device was comparable to novel oral anticoagulants in reducing stroke (odds ratio [OR] 0.85; credible interval [Cr.I] 0.63–1.05). Similarly, the reduction in the risk of all-cause mortality was comparable between the LAAC device and novel oral anticoagulants (OR 0.71; Cr.I 0.49–1.22). The LAAC device was found to be superior to novel oral anticoagulants in preventing hemorrhagic stroke (OR 0.45; Cr.I 0.29–0.79), whereas novel oral

  18. Injectable, high-density collagen gels for annulus fibrosus repair: An in vitro rat tail model.

    Science.gov (United States)

    Borde, Brandon; Grunert, Peter; Härtl, Roger; Bonassar, Lawrence J

    2015-08-01

    A herniated intervertebral disc often causes back pain when disc tissue is displaced through a damaged annulus fibrosus. Currently, the only methods available for annulus fibrosus repair involve mechanical closure of defect, which does little to address biological healing in the damaged tissue. Collagen hydrogels are injectable and have been used to repair annulus defects in vivo. In this study, high-density collagen hydrogels at 5, 10, and 15 mg/mL were used to repair defects made to intact rat caudal intervertebral discs in vitro. A group of gels at 15 mg/mL were also cross-linked with riboflavin at 0.03 mM, 0.07 mM, or 0.10 mM. These cross-linked, high-density collagen gels maintained their presence in the defect under loading and contributed positively to the mechanical response of damaged discs. Discs exhibited increases to 95% of undamaged effective equilibrium and instantaneous moduli as well as up to fourfold decreases in effective hydraulic permeability from the damaged discs. These data suggest that high-density collagen gels may be effective at restoring mechanical function of injured discs as well as potential vehicles for the delivery of biological agents such as cells or growth factors that may aid in the repair of the annulus fibrosus.

  19. Local Casimir Energies for an Annulus

    CERN Document Server

    Cavero-Pelaez, I; Wagner, J; Cavero-Pelaez, Ines; Milton, Kimball A.; Wagner, Jeffrey

    2005-01-01

    The local Casimir energy density for a massless scalar field associated with step-function potentials in a 3+1 dimensional spherical geometry is considered. The potential is chosen to be zero except in an annulus of thickness $\\delta$, where it has height $h$, $h\\delta=1$. In the limit of zero thickness, an ideal $\\delta$-function shell is recovered. The behavior of the energy density as the surface of the annulus is approached is studied in both the strong and weak coupling regimes. The former case corresponds to the well-known Dirichlet shell limit. New results, which shed light on the nature of surface divergences and on the energy contained within the annulus, are obtained in the weak coupling limit. In that case, the energy has a contribution not only from the local energy density, but from an energy term residing entirely on the surface. It is shown that the latter coincides with the integrated local energy density within the annulus. We also study the dependence of local and global quantities on the co...

  20. Incomplete RV Remodeling After Transcatheter ASD Closure in Pediatric Age.

    Science.gov (United States)

    Agha, Hala M; El-Saiedi, Sonia A; Shaltout, Mohamed F; Hamza, Hala S; Nassar, Hayat H; Abdel-Aziz, Doaa M; Tantawy, Amira Esmat El

    2015-10-01

    Published data showing the intermediate effect of transcatheter device closure of atrial septal defect (ASD) in the pediatric age-group are scarce. The objective of the study was to assess the effects of transcatheter ASD closure on right and left ventricular functions by tissue Doppler imaging (TDI). The study included 37 consecutive patients diagnosed as ASD secundum by transthoracic echocardiography and TEE and referred for transcatheter closure at Cairo University Specialized Pediatric Hospital, Egypt, from October 2010 to July 2013. Thirty-seven age- and sex-matched controls were selected. TDI was obtained using the pulsed Doppler mode, interrogating the right cardiac border (the tricuspid annulus) and lateral mitral annulus, and myocardial performance index (MPI) was calculated at 1-, 3-, 6- and 12-month post-device closure. Transcatheter closure of ASD and echocardiographic examinations were successfully performed in all patients. There were no significant differences between two groups as regards the age, gender, weight or BSA. TDI showed that patients with ASD had significantly prolonged isovolumetric contraction, relaxation time and MPI compared with control group. Decreased tissue Doppler velocities of RV and LV began at one-month post-closure compared with the controls. Improvement in RVMPI and LVMPI began at 1-month post-closure, but they are still prolonged till 1 year. Reverse remodeling of right and left ventricles began 1 month after transcatheter ASD closure, but did not completely normalize even after 1 year of follow-up by tissue Doppler imaging.

  1. Rarefied gas flow in a cylindrical annulus

    Science.gov (United States)

    Lo, S. S.; Loyalka, S. K.; Storvick, T. S.

    1983-09-01

    The Hansen-Morse model of the linearized Wang Chang-Uhlenbeck equation is used to study the thermal transpiration and mechanocaloric effects for rarefied polyatomic gases in a cylindrical annulus, where boundary conditions are characterized by diffuse reflection. Phenomenological coefficients at all degrees of rarefaction are reported for physical parameters that represent helium, hydrogen, carbon dioxide, and air. Comparisons with isothermal flow data are given.

  2. Mechanisms for mechanical damage in the intervertebral disc annulus fibrosus.

    Science.gov (United States)

    Iatridis, J C James C; ap Gwynn, Iolo

    2004-08-01

    Intervertebral disc degeneration results in disorganization of the laminate structure of the annulus that may arise from mechanical microfailure. Failure mechanisms in the annulus were investigated using composite lamination theory and other analyses to calculate stresses in annulus layers, interlaminar shear stress, and the region of stress concentration around a fiber break. Scanning electron microscopy (SEM) was used to evaluate failure patterns in the annulus and evaluate novel structural features of the disc tissue. Stress concentrations in the annulus due to an isolated fiber break were localized to approximately 5 microm away from the break, and only considered a likely cause of annulus fibrosus failure (i.e., radial tears in the annulus) under extreme loading conditions or when collagen damage occurs over a relatively large region. Interlaminar shear stresses were calculated to be relatively large, to increase with layer thickness (as reported with degeneration), and were considered to be associated with propagation of circumferential tears in the annulus. SEM analysis of intervertebral disc annulus fibrosus tissue demonstrated a clear laminate structure, delamination, matrix cracking, and fiber failure. Novel structural features noted with SEM also included the presence of small tubules that appear to run along the length of collagen fibers in the annulus and a distinct collagenous structure representative of a pericellular matrix in the nucleus region.

  3. Environmental Assessment For Cleanup and Closure of the Energy Technology Engineering Center. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2003-03-01

    DOE analyzed two cleanup and closure alternatives and the No Action Alternative, in accordance with the Council on Environmental Quality regulations implementing NEPA (40 CFR Parts 1500-1508) and DOE's NEPA implementing regulations (10 CFR Part 1021). Under Alternative 1, DOE is proposing to clean up the remaining ETEC facilities using the existing site specific cleanup standard of 15 mrem/yr. (plus DOE's As Low As Reasonably Achievable--ALARA-principle) for decontamination of radiological facilities and surrounding soils (Alternative 1). An annual 15-millirem additional radiation dose to the maximally exposed individual (assumed to be an individual living in a residential setting on Area IV) from all exposure pathways (air, soil, groundwater) equates to an additional theoretical lifetime cancer risk of no more than 3 x 10-4 (3 in 10,000). For perspective, it is estimated that the average individual in the United States receives a dose of about 300 millirem each year from natural sources of radiation. However, actual exposures generally will be much lower as a result of the application of the ''as low as reasonably achievable'' (ALARA) principle. Based on post-remediation verification sampling previous cleanups have generally resulted in a 2 x 10-6 level of residual risk. DOE would decontaminate, decommission, and demolish the remaining radiological facilities. DOE would also decommission and demolish the one remaining sodium facility and all of the remaining uncontaminated support buildings for which it is responsible. The ongoing RCRA corrective action program, including groundwater treatment (interim measures), would continue. Other environmental impacts would include 2.5 x 10-3 fatalities as a result of LLW shipments and 6.0 x 10-3 fatalities as a result of emission exhaust from all shipments. DOE would also decommission and demolish the remaining sodium facility and decommission and

  4. Environmental Assessment For Cleanup and Closure of the Energy Technology Engineering Center. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2003-03-01

    DOE analyzed two cleanup and closure alternatives and the No Action Alternative, in accordance with the Council on Environmental Quality regulations implementing NEPA (40 CFR Parts 1500-1508) and DOE's NEPA implementing regulations (10 CFR Part 1021). Under Alternative 1, DOE is proposing to clean up the remaining ETEC facilities using the existing site specific cleanup standard of 15 mrem/yr. (plus DOE's As Low As Reasonably Achievable--ALARA-principle) for decontamination of radiological facilities and surrounding soils (Alternative 1). An annual 15-millirem additional radiation dose to the maximally exposed individual (assumed to be an individual living in a residential setting on Area IV) from all exposure pathways (air, soil, groundwater) equates to an additional theoretical lifetime cancer risk of no more than 3 x 10-4 (3 in 10,000). For perspective, it is estimated that the average individual in the United States receives a dose of about 300 millirem each year from natural sources of radiation. However, actual exposures generally will be much lower as a result of the application of the ''as low as reasonably achievable'' (ALARA) principle. Based on post-remediation verification sampling previous cleanups have generally resulted in a 2 x 10-6 level of residual risk. DOE would decontaminate, decommission, and demolish the remaining radiological facilities. DOE would also decommission and demolish the one remaining sodium facility and all of the remaining uncontaminated support buildings for which it is responsible. The ongoing RCRA corrective action program, including groundwater treatment (interim measures), would continue. Other environmental impacts would include 2.5 x 10-3 fatalities as a result of LLW shipments and 6.0 x 10-3 fatalities as a result of emission exhaust from all shipments. DOE would also decommission and demolish the remaining sodium facility and decommission and

  5. Modeling mantle convection in the spherical annulus

    Science.gov (United States)

    Hernlund, John W.; Tackley, Paul J.

    2008-12-01

    Most methods for modeling mantle convection in a two-dimensional (2D) circular annular domain suffer from innate shortcomings in their ability to capture several characteristics of the spherical shell geometry of planetary mantles. While methods such as rescaling the inner and outer radius to reduce anomalous effects in a 2D polar cylindrical coordinate system have been introduced and widely implemented, such fixes may have other drawbacks that adversely affect the outcome of some kinds of mantle convection studies. Here we propose a new approach that we term the "spherical annulus," which is a 2D slice that bisects the spherical shell and is quantitatively formulated at the equator of a spherical polar coordinate system after neglecting terms in the governing equations related to variations in latitude. Spherical scaling is retained in this approximation since the Jacobian function remains proportional to the square of the radius. We present example calculations to show that the behavior of convection in the spherical annulus compares favorably against calculations performed in other 2D annular domains when measured relative to those in a fully three-dimensional (3D) spherical shell.

  6. Tank closure reducing grout

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, T.B.

    1997-04-18

    A reducing grout has been developed for closing high level waste tanks at the Savannah River Site in Aiken, South Carolina. The grout has a low redox potential, which minimizes the mobility of Sr{sup 90}, the radionuclide with the highest dose potential after closure. The grout also has a high pH which reduces the solubility of the plutonium isotopes. The grout has a high compressive strength and low permeability, which enhances its ability to limit the migration of contaminants after closure. The grout was designed and tested by Construction Technology Laboratories, Inc. Placement methods were developed by the Savannah River Site personnel.

  7. Peratrial Device Closure of a Congenital Coronary Artery Fistula through a Right Parasternal Approach: Innovative Use of Available Technology.

    Science.gov (United States)

    Jia, Yanting; Hongxin, Li; Wenbin, Guo; Zhang, Haizhou; Zou, Chengwei

    2016-02-16

    Current treatments for congenital coronary artery fistulas (CAFs) include surgical obliteration and transcatheter occlusion. However, surgical techniques involve significant trauma. Transcatheter occlusion is performed under fluoroscopy and angiography, in which radiation injury is inevitable. We present a patient, with a CAF from the left coronary artery to the right atrium, who underwent peratrial device closure of the CAF with a right parasternal approach under transesophageal echocardiography guidance. Complete occlusion was achieved by a symmetric ventricular septal occluder. We suggest that peratrial device closure of a congenital coronary artery fistula through a right parasternal approach may be a safe and effective option.

  8. Asymptotic Analysis of Transport Equation in Annulus

    Science.gov (United States)

    Wu, Lei; Yang, Xiongfeng; Guo, Yan

    2016-09-01

    We consider the diffusive limit of a steady neutron transport equation with one-speed velocity in a two-dimensional annulus. A classical theorem in Bensoussan et al. (Publ Res Inst Math Sci 15:53-157, 1979) states that the solution can be approximated in L^{∞} by the sum of the interior solution and Knudsen layer derived from Milne problem. However, this result was disproved in Wu and Guo (Commun Math Phys 336:1473-1553, 2015) in a plate via a different boundary layer expansion with geometric correction. In this paper, we established the diffusive limit and provide a counterexample to Bensoussan et al. (1979) in non-convex domains.

  9. COMPARISON OF PREOPERATIVE NONINVASIVE AND INTRAOPERATIVE MEASUREMENTS OF AORTIC ANNULUS

    Directory of Open Access Journals (Sweden)

    Manish Hinduja

    2016-10-01

    Full Text Available BACKGROUND Precise preoperative assessment of aortic annulus diameter is essential for sizing of aortic valve especially in patients planned for transcatheter aortic valve replacement. Computed Tomographic (CT and echocardiographic measurements of the aortic annulus vary because of elliptical shape of aortic annulus. This study was undertaken to compare the measurement of aortic annulus intraoperatively with preoperative noninvasive methods in patients undergoing aortic valve replacement. MATERIALS AND METHODS Aortic annulus diameter was measured with cardiac CT and Transesophageal Echocardiography (TEE prior to open aortic valve replacement in 30 patients with aortic valve stenosis. In CT, aortic annulus dimensions were measured in coronal plane, sagittal oblique plane and by planimetry. Both 2-dimensional and 3-dimensional TEE were used. These were compared with intraoperative measurements done by valve sizers and Hegar dilators. Pearson analysis was applied to test for degree of correlation. RESULTS CT in coronal and sagittal oblique plane tends to overestimate the diameter of aortic annulus when compared with intraoperative measurements (coefficient of relation, r = 0.798 and 0.749, respectively. CT measurements in single oblique plane showed a weaker correlation with intraoperative measurements than 3D TEE and 2D TEE (r = 0.917 and 0.898, respectively. However, CT measurements by planimetry method were most correlating with the intraoperative measurements (r = 0.951. CONCLUSION Noninvasive investigations with 3-dimensional views (CT-based measurement employing calculated average diameter assessment by planimetry and 3-dimensional TEE showed better correlation with intraoperative measurement of aortic annulus. CT-based aortic annulus measurement by planimetry seems to provide adequate dimensions most similar to operative measurements.

  10. Absence of annulus in human asthenozoospermia: case report.

    Science.gov (United States)

    Lhuillier, P; Rode, B; Escalier, D; Lorès, P; Dirami, T; Bienvenu, T; Gacon, G; Dulioust, E; Touré, A

    2009-06-01

    The annulus is a septin-based ring structure located at the junction of the midpiece (MP) and the principal piece (PP) of spermatozoa flagellum. In the mouse, deletion of Septin 4, a structural component of the sperm annulus, prevents annulus formation and leads to MP-PP disjunction, flagellar bending, asthenozoospermia and male sterility. Testis anion transporter 1 (Tat1) is a germ cell-specific member of the SLC26 anion transporter family and is co-expressed with Septin 4 at the sperm annulus. Interestingly, Tat1 null sperm bear an atrophic annulus, causing a phenotype similar to that of Sept4 null sperm. We searched for Tat1 misexpression and/or mislocalization in spermatozoa from asthenozoospermic subjects (n = 75) and controls by performing an immunofluorescence detection assay on sperm smear preparations. We found one patient showing moderate asthenozoospermia, with 97% of sperm lacking Tat1, Septin 4 and Septin 7 proteins at the annulus. We confirmed the absence of the annulus structure by transmission electron microscopy and observed that spermatozoa from the patient displayed MP-PP disjunction and abnormal mitochondrial organization. We show that the structural defects in sperm are not caused by abnormal transcription or point mutations of the TAT1 and SEPT4 genes; however, although both proteins are expressed, they are not properly localized at sperm annulus. The case we studied, so far unreported in human, confirms the involvement of Tat1 and Septin proteins in the constitution of the annulus, but also raises questions about the function of this structure in human sperm motility.

  11. Achieving closure at Fernald

    Energy Technology Data Exchange (ETDEWEB)

    Bradburne, John; Patton, Tisha C.

    2001-02-25

    When Fluor Fernald took over the management of the Fernald Environmental Management Project in 1992, the estimated closure date of the site was more than 25 years into the future. Fluor Fernald, in conjunction with DOE-Fernald, introduced the Accelerated Cleanup Plan, which was designed to substantially shorten that schedule and save taxpayers more than $3 billion. The management of Fluor Fernald believes there are three fundamental concerns that must be addressed by any contractor hoping to achieve closure of a site within the DOE complex. They are relationship management, resource management and contract management. Relationship management refers to the interaction between the site and local residents, regulators, union leadership, the workforce at large, the media, and any other interested stakeholder groups. Resource management is of course related to the effective administration of the site knowledge base and the skills of the workforce, the attraction and retention of qualified a nd competent technical personnel, and the best recognition and use of appropriate new technologies. Perhaps most importantly, resource management must also include a plan for survival in a flat-funding environment. Lastly, creative and disciplined contract management will be essential to effecting the closure of any DOE site. Fluor Fernald, together with DOE-Fernald, is breaking new ground in the closure arena, and ''business as usual'' has become a thing of the past. How Fluor Fernald has managed its work at the site over the last eight years, and how it will manage the new site closure contract in the future, will be an integral part of achieving successful closure at Fernald.

  12. Restaurant closures

    CERN Multimedia

    Novae Restauration

    2012-01-01

    Christmas Restaurant closures Please note that the Restaurant 1 and Restaurant 3 will be closed from Friday, 21 December at 5 p.m. to Sunday, 6 January, inclusive. They will reopen on Monday, 7 January 2013.   Restaurant 2 closure for renovation To meet greater demand and to modernize its infrastructure, Restaurant 2 will be closed from Monday, 17 December. On Monday, 14 January 2013, Sophie Vuetaz’s team will welcome you to a renovated self-service area on the 1st floor. The selections on the ground floor will also be expanded to include pasta and pizza, as well as snacks to eat in or take away. To ensure a continuity of service, we suggest you take your break at Restaurant 1 or Restaurant 3 (Prévessin).

  13. Small aortic valve annulus in children with fixed subaortic stenosis.

    Science.gov (United States)

    Thilenius, O G; Campbell, D; Bharati, S; Lev, M; Arcilla, R A

    1989-01-01

    Twenty-one hearts with fixed subaortic stenosis (FSAS) were examined pathologically. Thirty children with no hemodynamically significant heart disease, 31 children with valvar aortic stenosis, and 25 children with FSAS were studied by echo- and angiocardiography. The following conclusions were drawn: (1) Patients with FSAS often have abnormal aortic valve leaflets as well as small aortic valve annulus. (2) A small aortic annulus/descending aorta ratio is probably present at birth, and may decrease with increasing age. (3) In some patients with FSAS the aortic valve annulus is too small for simple resection of the fibroelastic tissue. A Konno operation is needed for these patients. (4) M-mode echocardiography has not been useful in identifying abnormally small aortic valve annulus in FSAS patients.

  14. Role of Mitral Annulus Diastolic Geometry on Intraventricular Filling Dynamics.

    Science.gov (United States)

    Okafor, Ikechukwu U; Santhanakrishnan, Arvind; Raghav, Vrishank S; Yoganathan, Ajit P

    2015-12-01

    The mitral valve (MV) is a bileaflet valve positioned between the left atrium and ventricle of the heart. The annulus of the MV has been observed to undergo geometric changes during the cardiac cycle, transforming from a saddle D-shape during systole to a flat (and less eccentric) D-shape during diastole. Prosthetic MV devices, including heart valves and annuloplasty rings, are designed based on these two configurations, with the circular design of some prosthetic heart valves (PHVs) being an approximation of the less eccentric, flat D-shape. Characterizing the effects of these geometrical variations on the filling efficiency of the left ventricle (LV) is required to understand why the flat D-shaped annulus is observed in the native MV during diastole in addition to optimizing the design of prosthetic devices. We hypothesize that the D-shaped annulus reduces energy loss during ventricular filling. An experimental left heart simulator (LHS) consisting of a flexible-walled LV physical model was used to characterize the filling efficiency of the two mitral annular geometries. The strength of the dominant vortical structure formed and the energy dissipation rate (EDR) of the measured fields, during the diastolic period of the cardiac cycle, were used as metrics to quantify the filling efficiency. Our results indicated that the O-shaped annulus generates a stronger (25% relative to the D-shaped annulus) vortical structure than that of the D-shaped annulus. It was also found that the O-shaped annulus resulted in higher EDR values throughout the diastolic period of the cardiac cycle. The results support the hypothesis that a D-shaped mitral annulus reduces dissipative energy losses in ventricular filling during diastole and in turn suggests that a symmetric stent design does not provide lower filling efficiency than an equivalent asymmetric design.

  15. Stability of fluid flow in a cylindrical annulus

    Science.gov (United States)

    Ludwieg, H.

    1984-01-01

    Helical flow in an annulus between two coaxial cylinders is investigated with regard to its stability against the formation of helical vortices of the type known as Taylor's annular vortices. Assuming the annulus to be small and the velocities to vary linearly with radius, it is shown that the problem can be reduced to the classical case of flow between two rotating cylinders. An appropriate stability criterion for helical flows is derived from Rayleigh's stability criterion applicable to such flows.

  16. Caseous Necrosis of Mitral Annulus: A Rare Cause of Stroke

    Directory of Open Access Journals (Sweden)

    Jérôme Corre

    2013-01-01

    Full Text Available The current report describes a rare case of a caseous necrosis presenting as a pseudotumor in ventricle, revealed by stroke. Cerebral MRI, showing multiples lacunes, evocates a cardioembolic mechanism. Transthoracic and transesophageal echocardiography demonstrate a large hyperechogenic mass fixed to the posterior mitral valve and annulus while thoracic tomography revealed a fully calcified lesion, at the mitral annulus, evocative of caseus necrosis. Medical therapy was preferred (anticoagulation, because of her age and the decaying nature of surgery.

  17. Loewner Theory in annulus II: Loewner chains

    CERN Document Server

    Contreras, Manuel D; Gumenyuk, Pavel

    2011-01-01

    Loewner Theory, based on dynamical viewpoint, proved itself to be a powerful tool in Complex Analysis and its applications. Recently Bracci et al [Bracci et al, to appear in J. Reine Angew. Math. Available on ArXiv 0807.1594; Bracci et al, Math. Ann. 344(2009), 947--962; Contreras et al, Revista Matematica Iberoamericana 26(2010), 975--1012] have proposed a new approach bringing together all the variants of the (deterministic) Loewner Evolution in a simply connected reference domain. This paper is devoted to the construction of a general version of Loewner Theory for the annulus launched in [ArXiv 1011.4253]. We introduce the general notion of a Loewner chain over a system of annuli and obtain a 1-to-1 correspondence between Loewner chains and evolution families in the doubly connected setting similar to that in the Loewner Theory for the unit disk. Futhermore, we establish a conformal classification of Loewner chains via the corresponding evolution families and via semicomplete weak holomorphic vector fields...

  18. SMART MONITORING AND DECISION MAKING FOR REGULATING ANNULUS BOTTOM HOLE PRESSURE WHILE DRILLING OIL WELLS

    Directory of Open Access Journals (Sweden)

    M. P. Vega

    Full Text Available Abstract Real time measurements and development of sensor technology are research issues associated with robustness and safety during oil well drilling operations, making feasible the diagnosis of problems and the development of a regulatory strategy. The major objective of this paper is to use an experimental plant and also field data, collected from a basin operation, offshore Brazil, for implementing smart monitoring and decision making, in order to assure drilling inside operational window, despite the commonly observed disturbances that produce fluctuations in the well annulus bottom hole pressure. Using real time measurements, the performance of a continuous automated drilling unit is analyzed under a scenario of varying levels of rate of penetration; aiming pressure set point tracking (inside the operational drilling window and also rejecting kick, a phenomenon that occurs when the annulus bottom hole pressure is inferior to the porous pressure, producing the migration of reservoir fluids into the annulus region. Finally, an empirical model was built, using real experimental data from offshore Brazil basins, enabling diagnosing and regulating a real drilling site by employing classic and advanced control strategies.

  19. CHARACTERIZATION OF TANK 16H ANNULUS SAMPLES PART II: LEACHING RESULTS

    Energy Technology Data Exchange (ETDEWEB)

    Hay, M.; Reboul, S.

    2012-06-19

    The closure of Tank 16H will require removal of material from the annulus of the tank. Samples from Tank 16H annulus were characterized and tested to provide information to evaluate various alternatives for removing the annulus waste. The analysis found all four annulus samples to be composed mainly of Si, Na, and Al and lesser amounts of other elements. The XRD data indicate quartz (SiO{sub 2}) and sodium aluminum nitrate silicate hydrate (Na{sub 8}(Al{sub 6}Si{sub 6}O{sub 24})(NO{sub 3}){sub 2}.4H{sub 2}O) as the predominant crystalline mineral phases in the samples. The XRD data also indicate the presence of crystalline sodium nitrate (NaNO{sub 3}), sodium nitrite (NaNO{sub 2}), gibbsite (Al(OH){sub 3}), hydrated sodium bicarbonate (Na{sub 3}H(CO{sub 3}){sub 2}.2H{sub 2}O), and muscovite (KAl{sub 2}(AlSi{sub 3}O{sub 10})(OH){sub 2}). Based on the weight of solids remaining at the end of the test, the water leaching test results indicate 20-35% of the solids dissolved after three contacts with an approximately 3:1 volume of water at 45 C. The chemical analysis of the leachates and the XRD results of the remaining solids indicate sodium salts of nitrate, nitrite, sulfate, and possibly carbonate/bicarbonate make up the majority of the dissolved material. The majority of these salts were dissolved in the first water contact and simply diluted with each subsequent water contact. The water leaching removed large amounts of the uranium in two of the samples and approximately 1/3 of the {sup 99}Tc from all four samples. Most of the other radionuclides analyzed showed low solubility in the water leaching test. The oxalic acid leaching test result indicate approximately 34-47% of the solids in the four annulus samples will dissolve after three contacts with an approximately 3:1 volume of acid to solids at 45 C. The same sodium salts found in the water leaching test comprise the majority of dissolved material in the oxalic acid leaching test. However, the oxalic acid was

  20. Tricuspid annulus: A spatial and temporal analysis

    Directory of Open Access Journals (Sweden)

    Ziyad O Knio

    2016-01-01

    Full Text Available Background: Traditional two-dimensional (2D echocardiographic evaluation of tricuspid annulus (TA dilation is based on single-frame measurements of the septolateral (S-L dimension. This may not represent either the axis or the extent of dynamism through the entire cardiac cycle. In this study, we used real-time 3D transesophageal echocardiography (TEE to analyze geometric changes in multiple axes of the TA throughout the cardiac cycle in patients without right ventricular abnormalities. Materials and Methods: R-wave-gated 3D TEE images of the TA were acquired in 39 patients undergoing cardiovascular surgery. The patients with abnormal right ventricular/tricuspid structure or function were excluded from the study. For each patient, eight points along the TA were traced in the 3D dataset and used to reconstruct the TA at four stages of the cardiac cycle (end- and mid-systole, end- and mid-diastole. Statistical analyses were applied to determine whether TA area, perimeter, axes, and planarity changed significantly over each stage of the cardiac cycle. Results: TA area (P = 0.012 and perimeter (P = 0.024 both changed significantly over the cardiac cycle. Of all the axes, only the posterolateral-anteroseptal demonstrated significant dynamism (P < 0.001. There was also a significant displacement in the vertical axis between the points and the regression plane in end-systole (P < 0.001, mid-diastole (P = 0.014, and mid-systole (P < 0.001. Conclusions: The TA demonstrates selective dynamism over the cardiac cycle, and its axis of maximal dynamism is different from the axis (S-L that is routinely measured with 2D TEE.

  1. Design of closure works

    NARCIS (Netherlands)

    Verhagen, H.J.

    2007-01-01

    This chapter discusses the design aspects of estuary and river closures and those of reservoir dams and certain other hydraulic structures. The focus of this chapter is on closures, not on the situation after the closure has been completed.

  2. Flow of viscoplastic fluids in a rotating concentric annulus

    DEFF Research Database (Denmark)

    Hassager, Ole; Bittleston, Simon H.

    1992-01-01

    pressure gradient is small compared to the yield stress of the fluid then the full solution predicts the existence of plugs attached to the outer wall of the annulus. The slot approximation fails to predict this feature. For larger pressure gradients the two solutions are in good agreement. The analytical......A difficulty in any flow calculation with viscoplastic fluids such as Bingham fluids is the determination of possible plug zones in which no deformation occurs. This paper investigates the flow in a concentric annulus when there is both an axial and tangential flow, the tangent flow arising from...... rotation of the inner cylinder of the annulus. The flow is analyzed by considering flow in a slot, for which an analytical solution is given, and by solving the full problem numerically. It is shown that when the boundary is set in motion an applied pressure gradient will always cause flow. If the applied...

  3. Nucleate boiling pressure drop in an annulus: Book 3

    Energy Technology Data Exchange (ETDEWEB)

    Block, J.A.; Crowley, C.; Dolan, F.X.; Sam, R.G.; Stoedefalke, B.H.

    1992-11-01

    The application of the work described in this report is the production reactors at the Savannah River Site, and the context is nuclear reactor safety. The Loss of Coolant Accident (LOCA) scenario considered involves a double-ended break of a primary coolant pipe in the reactor. During a LOCA, the flow through portions of the reactor may reverse direction or be greatly reduced, depending upon the location of the break. The reduced flow rate of coolant (D{sub 2}O) through the fuel assembly channels of the reactor -- downflow in this situation -- can lead to boiling and to the potential for flow instabilities which may cause some of the fuel assembly channels to overheat and melt. That situation is to be avoided. The experimental approach is to provide a test annulus which simulates geometry, materials, and flow conditions in a Mark-22 fuel assembly (Coolant Channel 3) to the extent possible. The annulus has a full-scale geometry, and in fat uses SRL dummy hardware for the inner annulus wall in the ribbed geometry. The materials aluminum. The annulus is uniformly heated in the axial direction, but the circumferential heat flux can be varied to provide ``power tilt`` or asymmetric heating of the inner and outer annulus walls. The test facility uses H{sub 2}O rather than D{sub 2}O, but it includes the effects of dissolved helium gas present in the reactor. The key analysis approaches are: To compare the minima in the measured demand curves with analytical criteria, in particular the Saha-Zuber (1974) model; and to compare the pressure and temperature as a function of length in the annulus with an integral model for flow boiling in a heated channel. This document consists of data plots and summary files of temperature measurements.

  4. Nucleate boiling pressure drop in an annulus: Book 6

    Energy Technology Data Exchange (ETDEWEB)

    1992-11-01

    The application of the work described in this report is the production reactors at the Savannah River Site, and the context is nuclear reactor safety. The Loss of Coolant Accident (LOCA) scenario considered involves a double-ended break of a primary coolant pipe in the reactor. During a LOCA, the flow through portions of the reactor may reverse direction or be greatly reduced, depending upon the location of the break. The reduced flow rate of coolant (D{sub 2}O) through the fuel assembly channels of the reactor -- downflow in this situation -- can lead to boiling and to the potential for flow instabilities which may cause some of the fuel assembly channels to overheat and melt. That situation is to be avoided. The experimental approach is to provide a test annulus which simulates geometry, materials, and flow conditions in a Mark-22 fuel assembly (Coolant Channel 3) to the extent possible. The annulus has a full-scale geometry, and in fat uses SRL dummy hardware for the inner annulus wall in the ribbed geometry. The materials aluminum. The annulus is uniformly heated in the axial direction, but the circumferential heat flux can be varied to provide ``power tilt`` or asymmetric heating of the inner and outer annulus walls. The test facility uses H{sub 2}O rather than D{sub 2}O, but it includes the effects of dissolved helium gas present in the reactor. The key analysis approaches are: To compare the minima in the measured demand curves with analytical criteria, in particular the Saha-Zuber (1974) model; and to compare the pressure and temperature as a function of length in the annulus with an integral model for flow boiling in a heated channel. This document consists of a summary of temperature measurements to include recorded minima, maxima, averages and standard deviations.

  5. Nucleate boiling pressure drop in an annulus: Book 4

    Energy Technology Data Exchange (ETDEWEB)

    Block, J.A.; Crowley, C.; Dolan, F.X.; Sam, R.G.; Stoedefalke, B.H.

    1992-11-01

    The application of the work described in this report is the production reactors at the Savannah River Site, and the context is nuclear reactor safety. The Loss of Coolant Accident (LOCA) scenario considered involves a double-ended break of a primary coolant pipe in the reactor. During a LOCA, the flow through portions of the reactor may reverse direction or be greatly reduced, depending upon the location of the break. The reduced flow rate of coolant (D{sub 2}O) through the fuel assembly channels of the reactor -- downflow in this situation -- can lead to boiling and to the potential for flow instabilities which may cause some of the fuel assembly channels to overheat and melt. That situation is to be avoided. The experimental approach is to provide a test annulus which simulates geometry, materials, and flow conditions in a Mark-22 fuel assembly (Coolant Channel 3) to the extent possible. The annulus has a full-scale geometry, and in fat uses SRL dummy hardware for the inner annulus wall in the ribbed geometry. The materials aluminum. The annulus is uniformly heated in the axial direction, but the circumferential heat flux can be varied to provide ``power tilt`` or asymmetric heating of the inner and outer annulus walls. The test facility uses H{sub 2}O rather than D{sub 2}O, but it includes the effects of dissolved helium gas present in the reactor. The key analysis approaches are: To compare the minima in the measured demand curves with analytical criteria, in particular the Saha-Zuber (1974) model; and to compare the pressure and temperature as a function of length in the annulus with an integral model for flow boiling in a heated channel. This document consists of data plots and summary files of temperature measurements.

  6. Nucleate boiling pressure drop in an annulus: Book 2

    Energy Technology Data Exchange (ETDEWEB)

    Block, J.A.; Crowley, C.; Dolan, F.X.; Sam, R.G.; Stoedefalke, B.H.

    1992-11-01

    The application of the work described in this report is the production reactors at the Savannah River Site, and the context is nuclear reactor safety. The Loss of Coolant Accident (LOCA) scenario considered involves a double-ended break of a primary coolant pipe in the reactor. During a LOCA, the flow through portions of the reactor may reverse direction or be greatly reduced, depending upon the location of the break. The reduced flow rate of coolant (D{sub 2}O) through the fuel assembly channels of the reactor -- downflow in this situation -- can lead to boiling and to the potential for flow instabilities which may cause some of the fuel assembly channels to overheat and melt. That situation is to be avoided. The experimental approach is to provide a test annulus which simulates geometry, materials, and flow conditions in a Mark-22 fuel assembly (Coolant Channel 3) to the extent possible. The annulus has a full-scale geometry, and in fat uses SRL dummy hardware for the inner annulus wall in the ribbed geometry. The materials aluminum. The annulus is uniformly heated in the axial direction, but the circumferential heat flux can be varied to provide ``power tilt`` or asymmetric heating of the inner and outer annulus walls. The test facility uses H{sub 2}O rather than D{sub 2}O, but it includes the effects of dissolved helium gas present in the reactor. The key analysis approaches are: To compare the minima in the measured demand curves with analytical criteria, in particular the Saha-Zuber (1974) model; and to compare the pressure and temperature as a function of length in the annulus with an integral model for flow boiling in a heated channel. Nineteen test series and a total of 178 tests were performed. Testing addressed the effects of: Heat flux; pressure; helium gas; power tilt; ribs; asymmetric heat flux.

  7. Nucleate boiling pressure drop in an annulus: Book 8

    Energy Technology Data Exchange (ETDEWEB)

    1992-11-01

    The application of the work described in this report is the production reactors at the Savannah River Site, and the context is nuclear reactor safety. The Loss of Coolant Accident (LOCA) scenario considered involves a double-ended break of a primary coolant pipe in the reactor. During a LOCA, the flow through portions of the reactor may reverse direction or be greatly reduced, depending upon the location of the break. The reduced flow rate of coolant (D{sub 2}O) through the fuel assembly channels of the reactor -- downflow in this situation -- can lead to boiling and to the potential for flow instabilities which may cause some of the fuel assembly channels to overheat and melt. That situation is to be avoided. The experimental approach is to provide a test annulus which simulates geometry, materials, and flow conditions in a Mark-22 fuel assembly (Coolant Channel 3) to the extent possible. The annulus has a full-scale geometry, and in fat uses SRL dummy hardware for the inner annulus wall in the ribbed geometry. The materials aluminum. The annulus is uniformly heated in the axial direction, but the circumferential heat flux can be varied to provide ``power tilt`` or asymmetric heating of the inner and outer annulus walls. The test facility uses H{sub 2}O rather than D{sub 2}O, but it includes the effects of dissolved helium gas present in the reactor. The key analysis approaches are: To compare the minima in the measured demand curves with analytical criteria, in particular the Saha-Zuber (1974) model; and to compare the pressure and temperature as a function of length in the annulus with an integral model for flow boiling in a heated channel. This document consists of tables of temperature measurements.

  8. Flow in a small annulus between concentric cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Luecke, M.; Mihelcic, M.; Wingerath, K. (Kernforschungsanlage Juelich G.m.b.H. (Germany, F.R.). Inst. fuer Festkoerperforschung); Pfister, G. (Kiel Univ. (Germany, F.R.). Inst. fuer Angewandte Physik)

    1984-03-01

    Rotationally symmetric vortex flows between concentric cylinders with the inner one rotating and the outer one at rest have been investigated by numerical simulation and by laser-Doppler velocimetry for an annulus of aspect ratio GAMMA = 1.05 with a radius ratio eta = 0.5066. Stationary states and relaxation towards them were explored close to the transition from the primary flow, which is mirror symmetric with respect to the midplane of the annulus, to a flow which gradually loses the symmetry. Detailed comparison of numerically simulated and measured velocity fields is made.

  9. Treatment of the degenerated intervertebral disc; closure, repair and regeneration of the annulus fibrosus

    NARCIS (Netherlands)

    Sharifi, Shahriar; Bulstra, Sjoerd K.; Grijpma, Dirk W.; Kuijer, Roel

    2015-01-01

    Degeneration of the intervertebral disc (IVD) and disc herniation are two causes of low back pain. The aetiology of these disorders is unknown, but tissue weakening, which primarily occurs due to inherited genetic factors, ageing, nutritional compromise and loading history, is the basic factor causi

  10. Treatment of the degenerated intervertebral disc; closure, repair and regeneration of the annulus fibrosus

    NARCIS (Netherlands)

    Sharifi, Shahriar; Bulstra, S.K.; Grijpma, Dirk W.; Kuijer, R.

    2015-01-01

    Degeneration of the intervertebral disc (IVD) and disc herniation are two causes of low back pain. The aetiology of these disorders is unknown, but tissue weakening, which primarily occurs due to inherited genetic factors, ageing, nutritional compromise and loading history, is the basic factor

  11. Radius ratio effects on natural heat transfer in concentric annulus

    DEFF Research Database (Denmark)

    Alipour, M.; Hosseini, R.; Kolaei, Alireza Rezania

    2013-01-01

    This paper studies natural convection heat transfer in vertical and electrically heated annulus. The metallic cylinders mounted concentrically in a parallel tube. Measurements are carried out for four input electric powers and three radius ratios with an apparatus immersed in stagnant air...

  12. Flow of viscoplastic fluids in a rotating concentric annulus

    DEFF Research Database (Denmark)

    Hassager, Ole; Bittleston, Simon H.

    1992-01-01

    A difficulty in any flow calculation with viscoplastic fluids such as Bingham fluids is the determination of possible plug zones in which no deformation occurs. This paper investigates the flow in a concentric annulus when there is both an axial and tangential flow, the tangent flow arising from ...

  13. Reproducibility of aortic annulus measurements by computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Schuhbaeck, Annika; Achenbach, Stephan [University of Erlangen, Department of Cardiology, Erlangen (Germany); University of Giessen, Department of Cardiology, Giessen (Germany); Pflederer, Tobias; Marwan, Mohamed; Schmid, Jasmin; Arnold, Martin [University of Erlangen, Department of Cardiology, Erlangen (Germany); Nef, Holger; Rixe, Johannes; Hecker, Franziska [University of Giessen, Department of Cardiology, Giessen (Germany); Schneider, Christian [University of Giessen, Department of Radiology, Giessen (Germany); Lell, Michael; Uder, Michael [University of Erlangen, Department of Radiology, Erlangen (Germany)

    2014-08-15

    To evaluate a systematic approach for measurement of aortic annulus dimensions by cardiac computed tomography. CT data sets of 64 patients were evaluated. An oblique cross-section aligned with the aortic root was created by systematically identifying the caudal insertion points of the three aortic cusps and sequentially aligning them in a double oblique plane. Aortic annulus dimensions, distances of coronary ostia and a suitable fluoroscopic projection angle were independently determined by two observers. Interobserver intraclass correlation coefficients (ICC) for aortic annulus diameters were excellent (ICC 0.89-0.93). Agreement for prosthesis size selection was excellent (k = 0.86 for mean, k = 0.84 for area-derived and k = 0.91 for circumference-derived diameter). Mean distances of the left/right coronary ostium were 13.4 ± 2.4/14.4 ± 2.8 mm for observer 1 and 13.2 ± 2.7/13.5 ± 3.2 mm for observer 2 (p = 0.30 and p = 0.0001, respectively; ICC 0.76/0.77 for left/right coronary artery). A difference of less than 10 for fluoroscopic projection angle was achieved in 84.3 % of patients. A systematic approach to generate a double oblique imaging plane exactly aligned with the aortic annulus demonstrates high interobserver and intraobserver agreements for derived measurements which are not influenced by aortic root calcification. (orig.)

  14. [Aortic valve replacement for the small aortic annulus].

    Science.gov (United States)

    Oshima, H; Usui, A; Akita, T; Ueda, Y

    2006-04-01

    Aortic valve surgery for the small aortic annulus is still challenging for surgeons. Recently, the new types of high performance prosthesis have been developed and the chance of an aortic root enlargement (ARE) is decreasing. In this study, we propose the ideal strategy of the aortic surgery for the small aortic annulus. We analyzed the clinical records of 158 patients who underwent aortic valve replacement from August 1999 to October 2005 in our institution. The small aortic annulus was observed in 38 patients (24%). Fourteen patients of this group underwent ARE. Patient-prosthesis mismatch (PPM) was less frequently observed in patients with ARE compared to those without ARE. The additional time required for ARE was not considerable, and neither ischemic time nor cardiopulmonary bypass time was significantly prolonged by ARE. In conclusion, we have to select a prosthesis with sufficient orifice area to avoid PPM, otherwise we should choose an option of ARE. For this consideration, we definitely need the chart that demonstrates the relationship between the nominal size of various types of prostheses and the size of a patient's annulus that those prostheses actually fit.

  15. Stability of Unsteady Mixed Convection in a Horizontal Concentric Annulus

    Directory of Open Access Journals (Sweden)

    Kamil Kahveci

    2016-01-01

    Full Text Available In this study, stability of unsteady mixed convection in a horizontal annulus between two concentric cylinders was investigated numerically. The surfaces of the cylinders were considered to be at fixed temperatures and it was assumed that the hot inner cylinder is rotating at a constant angular velocity. The buoyancy forces were formulated utilizing the Boussinesq approximation. The governing equations of fluid flow and heat transfer in the annulus were solved with a finite element method for different values of the geometric (radius ratio and transport parameters (Rayleigh number and Reynolds number. Development of the convective flow and heat transfer was expressed by the average Nusselt number for the outer cylinder. The results show that, for a narrow gap annulus, convective flow induces flow bifurcation and becomes unstable for high values of the Rayleigh number. Flow becomes more unstable with an increase in the Reynolds number. For a wide gap annulus, flow is stable for all values of the Rayleigh number if the rotation effects are small. On the other hand, convective flow becomes unstable for the modest and high values of the Ra number with an increase in the Re number.

  16. Hyperelastic anisotropic microplane constitutive model for annulus fibrosus.

    Science.gov (United States)

    Caner, Ferhun C; Guo, Zaoyang; Moran, Brian; Bazant, Zdenek P; Carol, Ignacio

    2007-10-01

    In a recent paper, Peng et al. (2006, "An Anisotropic Hyperelastic Constitutive Model With Fiber-Matrix Interaction for the Human Annulus Fibrosis," ASME J. Appl. Mech., 73(5), pp. 815-824) developed an anisotropic hyperelastic constitutive model for the human annulus fibrosus in which fiber-matrix interaction plays a crucial role in simulating experimental observations reported in the literature. Later, Guo et al. (2006, "A Composites-Based Hyperelastic Constitutive Model for Soft Tissue With Application to the Human Fibrosis," J. Mech. Phys. Solids, 54(9), pp. 1952-1971) used fiber reinforced continuum mechanics theory to formulate a model in which the fiber-matrix interaction was simulated using only composite effect. It was shown in these studies that the classical anisotropic hyperelastic constitutive models for soft tissue, which do not account for this shear interaction, cannot accurately simulate the test data on human annulus fibrosus. In this study, we show that the microplane model for soft tissue developed by Caner and Carol (2006, "Microplane Constitutive Model and Computational Framework for Blood Vessel Tissue," ASME J. Biomech. Eng., 128(3), pp. 419-427) can be adjusted for human annulus fibrosus and the resulting model can accurately simulate the experimental observations without explicit fiber-matrix interaction because, in microplane model, the shear interaction between the individual fibers distributed in the tissue provides the required additional rigidity to explain these experimental facts. The intensity of the shear interaction between the fibers can be adjusted by adjusting the spread in the distribution while keeping the total amount of the fiber constant. A comparison of results obtained from (i) a fiber-matrix parallel coupling model, which does not account for the fiber-matrix interaction, (ii) the same model but enriched with fiber-matrix interaction, and (iii) microplane model for soft tissue adapted to annulus fibrosus with two

  17. Growth of mitral annulus in the pediatric patient after suture annuloplasty of the entire posterior mitral annulus.

    Science.gov (United States)

    Komoda, Takeshi; Huebler, Michael; Berger, Felix; Hetzer, Roland

    2009-08-01

    When mitral annuloplasty is performed in small children, room for annular growth should be allowed. However, it has not been reported how the valve develops after mitral annuloplasty of the entire posterior annulus. We report a case showing traces of annular growth at redo surgery. A female patient suffering from mitral valve insufficiency due to annular dilatation underwent modified Paneth plasty with Kay-Wooler commissural plication annuloplasty at the age of two years one month. In redo surgery 8.4 years after initial repair, enlargement of the commissural portion of the posterior annulus in addition to enlargement of the anterior leaflet and anterior annulus was observed. Modified Paneth plasty reinforced with a pericardial strip and Kay-Wooler annuloplasty of the posteromedial commissure were performed. Mitral orifice size measured with the Hegar dilator was 18 mm after the re-repair, increasing from 16 mm after the initial repair. Taking into account the normal mitral annulus diameter related to body surface area (BSA) of 16 mm at initial operation and 20 mm at redo surgery, the increase in mitral orifice size from 16 mm to 18 mm in this patient may be regarded as the annular growth in 8.4 years.

  18. Nematic Equilibria on a Two-Dimensional Annulus

    KAUST Repository

    Lewis, A. H.

    2017-01-16

    We study planar nematic equilibria on a two-dimensional annulus with strong and weak tangent anchoring, in the Oseen–Frank theoretical framework. We analyze a radially invariant defect-free state and compute analytic stability criteria for this state in terms of the elastic anisotropy, annular aspect ratio, and anchoring strength. In the strong anchoring case, we define and characterize a new spiral-like equilibrium which emerges as the defect-free state loses stability. In the weak anchoring case, we compute stability diagrams that quantify the response of the defect-free state to radial and azimuthal perturbations. We study sector equilibria on sectors of an annulus, including the effects of weak anchoring and elastic anisotropy, giving novel insights into the correlation between preferred numbers of boundary defects and the geometry. We numerically demonstrate that these sector configurations can approximate experimentally observed equilibria with boundary defects.

  19. Formation of the Terrestrial Planets from a Narrow Annulus

    CERN Document Server

    Hansen, Brad

    2009-01-01

    We show that the assembly of the Solar System terrestrial planets can be successfully modelled with all of the mass initially confined to a narrow annulus between 0.7 and 1.0 AU. With this configuration, analogues of Mercury and Mars often form from the collisional evolution of material diffusing out of the annulus under the scattering of the forming Earth and Venus analogues. The final systems also possess eccentricities and inclinations that match the observations, without recourse to dynamical friction from remnant small body populations. Finally, the characteristic assembly timescale for Earth analogues is rapid in this model, and consistent with cosmochemical models based on the $^{182}$Hf--$^{182}$W isotopes. The agreement between this model and the observations suggests that terrestrial planet systems may also be formed in `planet traps', as has been proposed recently for the cores of giant planets in our solar system and others.

  20. A numerical study of natural convection in a narrow annulus

    Energy Technology Data Exchange (ETDEWEB)

    Sahai, V.

    1991-12-01

    Various numerical models were used to predict the natural convection of a solidifying liquid metal in a narrow annulus. Previous work in this area do not consider the temperature variation that exists in the fluid and the resulting heat conduction in the solid mold material. The finite element fluid dynamics code FIDAP was sued to solve these models. The results indicate that the natural convective effects are small. 6 refs.

  1. A numerical study of natural convection in a narrow annulus

    Science.gov (United States)

    Sahai, V.

    1991-12-01

    Various numerical models were used to predict the natural convection of a solidifying liquid metal in a narrow annulus. Previous work in this area does not consider the temperature variation that exists in the fluid and the resulting heat conduction in the solid mold material. The finite element fluid dynamics code FIDAP was used to solve these models. The results indicate that the natural convective effects are small.

  2. Instability of diverging and converging flows in an annulus

    CERN Document Server

    Ilin, Konstantin

    2012-01-01

    The stability of two-dimensional diverging and converging flows in an annulus between two permeable cylinders is examined. The basic flow is irrotational and has both the radial and azimuthal components. It is shown that for a wide range of the parameters of the problem, the basic flow is unstable to small two-dimensional perturbations. The instability is inviscid and oscillatory and persists if the viscosity of the fluid is taken into consideration.

  3. Vacuum decay container/closure integrity testing technology. Part 1. ASTM F2338-09 precision and bias studies.

    Science.gov (United States)

    Wolf, Heinz; Stauffer, Tony; Chen, Shu-Chen Y; Lee, Yoojin; Forster, Ronald; Ludzinski, Miron; Kamat, Madhav; Godorov, Phillip; Guazzo, Dana Morton

    2009-01-01

    ASTM F2338-09 Standard Test Method for Nondestructive Detection of Leaks in Packages by Vacuum Decay Method is applicable for leak-testing rigid and semi-rigid non-lidded trays; trays or cups sealed with porous barrier lidding materials; rigid, nonporous packages; and flexible, nonporous packages. Part 1 of this series describes the precision and bias studies performed in 2008 to expand this method's scope to include rigid, nonporous packages completely or partially filled with liquid. Round robin tests using three VeriPac 325/LV vacuum decay leak testers (Packaging Technologies & Inspection, LLC, Tuckahoe, NY) were performed at three test sites. Test packages were 1-mL glass syringes. Positive controls had laser-drilled holes in the barrel ranging from about 5 to 15 microm in nominal diameter. Two different leak tests methods were performed at each site: a "gas leak test" performed at 250 mbar (absolute) and a "liquid leak test" performed at about 1 mbar (absolute). The gas leak test was used to test empty, air-filled syringes. All defects with holes > or = 5.0 microm and all no-defect controls were correctly identified. The only false negative result was attributed to a single syringe with a ASTM F2338-09 test method and the precision and bias study report are available by contacting ASTM International in West Conshohocken, PA, USA (www.astm.org).

  4. Closure Issues with Families.

    Science.gov (United States)

    Craig, Steven E.; Bischof, Gary H.

    Closure of the counseling relationship constitutes both an ending and a beginning. Although closure signifies the ending of the present counseling relationship, many family counselors conceptualize closure as the start of a working relationship between counselor and family that may be summoned in future times of crisis or during a difficult life…

  5. Simple annulus power balance in EBT-I

    Energy Technology Data Exchange (ETDEWEB)

    Borowski, S.K.; Uckan, N.A.; Jaeger, E.F.; Kammash, T.

    1979-09-01

    An essential feature of the ELMO Bumpy Torus (EBT) concept is the presence of a relativistic electron annulus in each of the toroidal mirror sectors. These high beta annuli are formed and sustained by microwave heating and are of sufficient density and temperature that diamagnetic currents produce the necessary minimum in the magnetic field required for MHD stability of the toroidal core plasma. Because electron rings play an important role in confinement characteristics and performance of EBT, the trade-off between the quality of the confinement afforded by the rings and the power required to sustain the rings represents an important problem in a fusion reactor. Theoretical estimates of the microwave power required to sustain the annulus are found to be within a factor of 2 of the experimentally determined value. Scaling projections that are shown for both EBT-I and EBT-S enable one to examine the sensitivity of the annulus electron temperature as a function of core plasma density for various microwave power levels. The results are found to be sensitive to the details of the hot electron distribution function as well as geometric and scaling parameters. Improvements to the model are under way in order to increase its capability and accuracy in assessing the overall power balance.

  6. Closure The Definitive Guide

    CERN Document Server

    Bolin, Michael

    2010-01-01

    If you're ready to use Closure to build rich web applications with JavaScript, this hands-on guide has precisely what you need to learn this suite of tools in depth. Closure makes it easy for experienced JavaScript developers to write and maintain large and complex codebases -- as Google has demonstrated by using Closure with Gmail, Google Docs, and Google Maps. Author and Closure contributor Michael Bolin has included numerous code examples and best practices, as well as valuable information not available publicly until now. You'll learn all about Closure's Library, Compiler, Templates, tes

  7. Reliability assessment of underground shaft closure

    Energy Technology Data Exchange (ETDEWEB)

    Fossum, A.F. [RE/SPEC, Inc., Rapid City, SD (United States); Munson, D.E. [Sandia National Labs., Albuquerque, NM (United States)

    1994-12-31

    The intent of the WIPP, being constructed in the bedded geologic salt deposits of Southeastern New Mexico, is to provide the technological basis for the safe disposal of radioactive Transuranic (TRU) wastes generated by the defense programs of the United States. In determining this technological basis, advanced reliability and structural analysis techniques are used to determine the probability of time-to-closure of a hypothetical underground shaft located in an argillaceous salt formation and filled with compacted crushed salt. Before being filled with crushed salt for sealing, the shaft provides access to an underground facility. Reliable closure of the shaft depends upon the sealing of the shaft through creep closure and recompaction of crushed backfill. Appropriate methods are demonstrated to calculate cumulative distribution functions of the closure based on laboratory determined random variable uncertainty in salt creep properties.

  8. Project W-320 high vacuum 241-AY-102 annulus ventilation system operability test report

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, J.W.

    1998-03-12

    This report documents the test results of OTP-320-001, Tank 241-AY-102 Annulus Ventilation System Testing. Included in the appendices are: (1) Supporting documentation prepared to demonstrate the structural integrity of the tank at high annulus vacuum (<20 INWG), and (2) a report that identifies potential cross connections between the primary and annulus ventilation systems. These cross connections were verified to be eliminated prior to the start of testing.

  9. A technique of aortic annulus enlargement with a Freestyle stentless bioprosthesis.

    Science.gov (United States)

    Bical, Olivier M; Nutu, Ovidiu; Deleuze, Philippe

    2012-02-01

    We describe our surgical technique to manage a small aortic annulus during aortic valve replacement. Starting with the posterior annular enlargement incision described by Manouguian, a stentless porcine aortic root, with excision of the left and right porcine coronary segments and conservation of the mural wall (Freestyle MS design, Medtronic, Minneapolis, MN ), was used. The Freestyle bioprosthesis enlarges the aortic annulus using a direct suture of the valve on the enlarged annulus, and the aorta is closed by a direct suture of the mural wall of the bioprosthesis. Therefore, the aortic annulus enlargement is made only using the aortic bioprosthesis, without other material.

  10. Numerical analysis of laminar forced convection in a spherical annulus

    Energy Technology Data Exchange (ETDEWEB)

    Tuft, D.B.

    1980-07-21

    Calculations of steady laminar incompressible fluid-flow and heat transfer in a spherical annulus are presented. Steady pressures, temperatures, velocities, and heat transfer coefficients are calculated for an insulated outer sphere and a 0/sup 0/C isothermal inner sphere with 50/sup 0/C heated water flowing in the annulus. The inner sphere radius is 13.97 cm, the outer sphere radius is 16.83 cm and the radius ratio is 1.2. The transient axisymmetric equations of heat, mass, and momentum conservation are solved numerically in spherical coordinates. The transient solution is carried out in time until steady state is achieved. A variable mesh is used to improve resolution near the inner sphere where temperature and velocity gradients are steep. It is believed that this is the first fully two-dimensional analysis of forced flow in a spherical annulus. Local and bulk Nusselt numbers are presented for Reynolds numbers from 4.4 to 440. Computed bulk Nusselt numbers ranged from 2 to 50 and are compared to experimental results from the literature. Inlet flow jetting off the inner sphere and flow separation are predicted by the analysis. The location of wall jet separation was found to be a function of Reynolds number, indicating the location of separation depends upon the ratio of inertia to viscous forces. Wall jet separation has a pronounced effect on the distribution of local heat flux. The area between inlet and separation was found to be the most significant area for heat transfer. Radial distributions of azimuthal velocity and temperature are presented for various angles beginning at the inlet. Inner sphere pressure distribution is presented and the effect on flow separation is discussed.

  11. Closure Operators and Closure Systems on Quantaloid-Enriched Categories

    Institute of Scientific and Technical Information of China (English)

    Min LIU; Bin ZHAO

    2013-01-01

    In this paper,we introduce the fundamental notions of closure operator and closure system in the framework of quantaloid-enriched category.We mainly discuss the relationship between closure operators and adjunctions and establish the one-to-one correspondence between closure operators and closure systems on quantaloid-enriched categories.

  12. Magnetorotational Instability in a Rotating Liquid Metal Annulus

    Energy Technology Data Exchange (ETDEWEB)

    Hantao Ji; Jeremy Goodman; Akira Kageyama

    2001-03-10

    Although the magnetorotational instability (MRI) has been widely accepted as a powerful accretion mechanism in magnetized accretion disks, it has not been realized in the laboratory. The possibility of studying MRI in a rotating liquid-metal annulus (Couette flow) is explored by local and global stability analysis and magnetohydrodynamic (MHD) simulations. Stability diagrams are drawn in dimensionless parameters, and also in terms of the angular velocities at the inner and outer cylinders. It is shown that MRI can be triggered in a moderately rapidly rotating table-top apparatus, using easy-to-handle metals such as gallium. Practical issues of this proposed experiment are discussed.

  13. Fibre-matrix interaction in the human annulus fibrosus.

    Science.gov (United States)

    Guo, Zaoyang; Shi, Xiaohao; Peng, Xiongqi; Caner, Ferhun

    2012-01-01

    Although the mechanical behaviour of the human annulus fibrosus has been extensively studied, the interaction between the collagen fibres and the ground matrix has not been well understood and is therefore ignored by most constitutive models. The objective of this study is to identify the significance of the fibre-matrix interaction in the human annulus fibrosus by careful investigation of the experimental data, the theoretical constitutive models, and the numerical simulation results in the literature. Based on the experimental results from biaxial and uniaxial tests, it is shown that the mechanical behaviour of the matrix can be well simulated by an incompressible neo-Hookean type model, but the effective stiffness of the matrix depends on fibre stretch ratio, which can only be explained by fibre-matrix interaction. Furthermore, we find that this interaction takes place anisotropically between the matrix and the fibres distributed in different proportions in different directions. The dependence of the tangent stiffness of the matrix on the first invariant of the deformation tensor can also be explained by this fibre orientation dispersion.

  14. Nucleate boiling pressure drop in an annulus: Book 5

    Energy Technology Data Exchange (ETDEWEB)

    1992-11-01

    The application of the work described in this report is the production reactors at the Savannah River Site, and the context is nuclear reactor safety. The Loss of Coolant Accident (LOCA) scenario considered involves a double-ended break of a primary coolant pipe in the reactor. During a LOCA, the flow through portions of the reactor may reverse direction or be greatly reduced, depending upon the location of the break. The reduced flow rate of coolant (D{sub 2}O) through the fuel assembly channels of the reactor -- downflow in this situation -- can lead to boiling and to the potential for flow instabilities which may cause some of the fuel assembly channels to overheat and melt. That situation is to be avoided. The experimental approach is to provide a test annulus which simulates geometry, materials, and flow conditions in a Mark-22 fuel assembly (Coolant Channel 3) to the extent possible. The key analysis approaches are: To compare the minima in the measured demand curves with analytical criteria, in particular the Saha-Zuber (1974) model; and to compare the pressure and temperature as a function of length in the annulus with an integral model for flow boiling in a heated channel. Nineteen test series and a total of 178 tests were performed. Testing addressed the effects of: Heat flux; pressure; helium gas; power tilt; ribs; asymmetric heat flux. This document consists solely of the plato file index from 11/87 to 11/90.

  15. Dufour and Soret Effects on Square Porous Annulus

    Directory of Open Access Journals (Sweden)

    N. Nik-Ghazali

    2014-04-01

    Full Text Available A study on heat and mass transfer behaviour on porous medium embedded in a square annulus is conducted. The inner surface wall is considered to have a cool temperature Tc while the outer surface is exposed to a hot temperature Th. Finite element method (FEM is used to solve the governing partial differential equations. The results present the influences of the Dufour and Soret effects on the heat and mass transfer of a square annulus. The effects of various physical parameters on the temperature and concentration profiles together with the local Nusselt and Sherwood numbers are presented graphically. It is found that when Dufour parameter is increased, Nusselt number increases. Dufour effect has more influences on velocity profile, while it has no significant effect on the concentration and can be deemed negligible. It is observed that the local Nusselt number is highest at the bottom wall for low values of Dufour parameter; however, the top wall Nusselt number is highest for higher values of Dufour parameter. Soret effect tends to make more significant contribution to the concentration profile than Dufour effect.

  16. Aortic valve replacement with the Nicks annulus enlargement procedure 12 years after mitral valve replacement.

    Science.gov (United States)

    Kazama, S; Kurata, A; Yamashita, Y

    1999-10-01

    An aortic valve replacement was successfully performed employing the Nicks annulus enlargement procedure in a case of aortic valve stenosis with small annulus 12 years after mitral valve replacement. Previous mitral valve replacement does not preclude feasibility of the Nicks procedure.

  17. Design and analysis of annulus core few mode EDFA for modal gain equalization

    CERN Document Server

    Gaur, Ankita

    2016-01-01

    Few-mode fiber amplifier is widely under study to overcome the issue of internet traffic in optical communication. This article proposes annulus core few-mode erbium doped fiber (FM-EDF) with annulus or extra annulus doping for amplification of the LP01, LP11, LP21, and LP31 signal mode groups with low differential modal gain (DMG). Our simulations confirm that extra annulus doping helps in reducing DMG of higher order mode groups. We have achieved less than 2.2 dB DMG over C-band for 4-mode groups using extra annulus doping. The proposed EDF would be useful for space division multiplexing (SDM) based optical fiber communication system.

  18. Design and Analysis of Annulus Core Few Mode EDFA for Modal Gain Equalization

    Science.gov (United States)

    Gaur, Ankita; Rastogi, Vipul

    2016-05-01

    Few-mode fiber amplifier is widely under study to overcome the issue of internet traffic in optical communication. This article proposes annulus core few-mode erbium doped fiber (FM-EDF) with annulus or extra annulus doping for amplification of the LP01, LP11, LP21, and LP31 signal mode groups with low differential modal gain (DMG). Our simulations confirm that extra annulus doping helps in reducing DMG of higher order mode groups. We have achieved less than 2.2 dB DMG over C-band for 4-mode groups using extra annulus doping. The proposed EDF would be useful for space division multiplexing (SDM) based optical fiber communication system.

  19. In vivo dynamic deformation of the mitral valve annulus.

    Science.gov (United States)

    Eckert, Chad E; Zubiate, Brett; Vergnat, Mathieu; Gorman, Joseph H; Gorman, Robert C; Sacks, Michael S

    2009-09-01

    Though mitral valve (MV) repair surgical procedures have increased in the United States [Gammie, J. S., et al. Ann. Thorac. Surg. 87(5):1431-1437, 2009; Nowicki, E. R., et al. Am. Heart J. 145(6):1058-1062, 2003], studies suggest that altering MV stress states may have an effect on tissue homeostasis, which could impact the long-term outcome [Accola, K. D., et al. Ann. Thorac. Surg. 79(4):1276-1283, 2005; Fasol, R., et al. Ann. Thorac. Surg. 77(6):1985-1988, 2004; Flameng, W., P. Herijgers, and K. Bogaerts. Circulation 107(12):1609-1613, 2003; Gillinov, A. M., et al. Ann. Thorac. Surg. 69(3):717-721, 2000]. Improved computational modeling that incorporates structural and geometrical data as well as cellular components has the potential to predict such changes; however, the absence of important boundary condition information limits current efforts. In this study, novel high definition in vivo annular kinematic data collected from surgically implanted sonocrystals in sheep was fit to a contiguous 3D spline based on quintic-order hermite shape functions with C(2) continuity. From the interpolated displacements, the annular axial strain and strain rate, bending, and twist along the entire annulus were calculated over the cardiac cycle. Axial strain was shown to be regionally and temporally variant with minimum and maximum values of -10 and 4%, respectively, observed. Similarly, regionally and temporally variant strain rate values, up to 100%/s contraction and 120%/s elongation, were observed. Both annular bend and twist data showed little deviation from unity with limited regional variations, indicating that most of the energy for deformation was associated with annular axial strain. The regionally and temporally variant strain/strain rate behavior of the annulus are related to the varied fibrous-muscle structure and contractile behavior of the annulus and surrounding ventricular structures, although specific details are still unavailable. With the high resolution

  20. Dispersion phenomena in helical flow in a concentric annulus.

    Science.gov (United States)

    Song, Young Seok; Brenner, Howard

    2009-12-14

    We examined dispersion phenomena of solutes in helical flow in a concentric annulus through a multiscale approach. The helical flow was developed by the combination of the Poiseuille flow and Couette flow. Here, we present an analytic model that can address the multidimensional Taylor dispersion in the helical flow under a lateral field of thermophoresis (or thermal diffusion) in the gapwise direction. Macroscopic parameters including the average solute velocity and dispersivity were analyzed using relevant microscopic physicochemical properties. The mathematically obtained results were validated by the numerical simulation carried out in this study. The findings show that macrotransport processes are robust and straightforward to handle multidimensional dispersion phenomena of solutes in helical flow. This study is expected to provide a theoretical platform for applications of helical flow such as tube exchangers, oil drilling, and multidimensional field flow fractionations (e.g., helical flow field flow fractionation).

  1. Opposing flow in square porous annulus: Influence of Dufour effect

    Science.gov (United States)

    Athani, Abdulgaphur; Al-Rashed, Abdullah A. A. A.; Khaleed, H. M. T.

    2016-06-01

    Heat and mass transfer in porous medium is very important area of research which is also termed as double diffusive convection or thermo-solutal convection. The buoyancy ratio which is the ratio of thermal to concentration buoyancy can have negative values thus leading to opposing flow. This article is aimed to study the influence of Dufour effect on the opposing flow in a square porous annulus. The partial differential equations that govern the heat and mass transfer behavior inside porous medium are solved using finite element method. A three node triangular element is used to divide the porous domain into smaller elements. Results are presented with respect to geometric and physical parameters such as duct diameter ratio, Rayleigh number, radiation parameter etc. It is found that the heat transfer increase with increase in Rayleigh number and radiation parameter. It is observed that Dufour coefficient has more influence on velocity profile.

  2. On the flow in an annulus surrounding a whirling cylinder

    Science.gov (United States)

    Brennen, C.

    1976-01-01

    When fluid in an annulus between two cylinders is set in motion by whirling movements of one or both of the cylinders, dynamic forces are imposed by the fluid on the cylinders. Knowledge of these forces is frequently important, indeed often critical, to the engineer designing rotor systems or journal bearings. Quite general solutions of the Navier-Stokes equations are presented for this problem and are limited only by restrictions on the amplitude of the whirl motion. From these solutions, the forces are derived under a wide variety of circumstances, including large and small annular widths, high and low Reynolds numbers, and the presence and absence of a mean flow created by additional net rotation of one or both of the cylinders.

  3. Eyelid closure at death

    Directory of Open Access Journals (Sweden)

    A D Macleod

    2009-01-01

    Full Text Available Aim: To observe the incidence of full or partial eyelid closure at death. Materials and Methods: The presence of ptosis was recorded in 100 consecutive hospice patient deaths. Results: Majority (63% of the patients died with their eyes fully closed, however, 37% had bilateral ptosis at death, with incomplete eye closure. In this study, central nervous system tumor involvement and/or acute hepatic encephalopathy appeared to be pre-mortem risk factors of bilateral ptosis at death. Conclusion: Organicity and not psychogenicity is, therefore, the likely etiology of failure of full eyelid closure at death.

  4. New Annulus Testing Pipe String Development%新型环空测试工艺管柱研制

    Institute of Scientific and Technical Information of China (English)

    于洋洋; 高翔; 刘宇飞

    2016-01-01

    Annulus logging technology has the following advantage,less working procedure,high data accuracy,so it was favored by the oil field.With the development of oil field,but with the in-crease of the deepening of oilfield development and deep deviated well,the inadaptability of the annulus test technology is gradually emerging,cable winding has appeared,a crescent shaped space is insufficient,decentralized wellhead rebound and other issues.To solve these problems, small tubing ring empty testing pipe string was designed,and three kinds of supporting tools are researched,especially the downhole tubing rotator,effective solve the pipe string rotation prob-lems in deviated well.%针对环空测试工艺技术出现电缆缠绕、“月牙形”空间不足、偏心井口反弹等问题,设计了小油管环空测试工艺管柱,并研发了3种配套工具,特别是井下油管旋转器,有效解决了斜井管柱转不动的问题。

  5. HEAT TRANSFER ENHANCEMENT AND PRESSURE DROP OF GROOVED ANNULUS OF DOUBLE PIPE HEAT EXCHANGER

    Directory of Open Access Journals (Sweden)

    Putu Wijaya Sunu

    2017-05-01

    Full Text Available This investigation was performed to experimentally investigate the enhancement of heat transfer and the friction of an annulus in a double pipe heat exchanger system with rectangular grooves in the turbulent flow regime. The shell is made of acrylic and its diameter is 28 mm. The tube is made of aluminium and its diameter is 20 mm. Grooves were incised in the annulus room with a circumferential pattern, with a groove space of 2 mm, a distance between the grooves of 8mm and a groove height of 0.3 mm. The experiments consist of temperature and pressure measurement and a flow visualization. Throughout the investigation, the cold fluid flowed in the annulus room. The Reynold number of cold fluid varied from about 31981 to 43601 in a counter flow condition. The volume flow rate of hot fluid remains constant with Reynold number about 30904. Result showed the effect of grooves, which are applied in the annulus room. The grooves induce the pressure drop, the pressure drop in the grooved annulus was greater by about 15.88% to 16.72% than the one in the smooth annulus. The total heat transfer enhancement is of 1.09–1.11. Moreover, the use of grooves in the annulus of the heat exchanger not only increase the heat transfer process, but also increase the pressure drop, which is related to the friction factor.

  6. Application of Regent mechanical valve in patients with small aortic annulus: 3-year follow-up

    OpenAIRE

    Zhao Dong; Wang Chunsheng; Hong Tao; Pan Cuizhen; Guo Changfa

    2012-01-01

    Abstract Background Aortic valve replacement (AVR) with a small aortic annulus is always challenging for the cardiac surgeon. In this study, we sought to evaluate the midterm performance of implantation with a 17-mm or 19-mm St. Jude Medical Regent (SJM Regent) mechanical valve in retrospective consecutive cohort of patients with small aortic annulus (diameter ≤ 19 mm). Methods From January 2008 to April 2011, 40 patients (31 female, mean age = 47.2 ± 5.8 years) with small aortic annulus (≤19...

  7. analysis of flow in a concentric annulus using finite element method

    African Journals Online (AJOL)

    user

    ABSTRACT. This work presents the computational modelling of the velocity distribution of an incompressible fluid flowing in a ... concentric annulus with center body rotation. [9] used .... pipe at a glance with a very high accuracy compared to.

  8. The Cyclicity of the Period Annulus Around the Quadratic Isochronous Center

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The number of the limit cycles bifurcating in small quadratic perturbations of quadratic systems with an isochronous center is studied, it turns out that the cyclicity of the period annulus around one kind of quadratic isochronous center is two.

  9. Aortic valve replacement with concomitant annular enlargement for small aortic annulus of less than 19 mm.

    Science.gov (United States)

    Takakura, H; Sasaki, T; Hashimoto, K; Hachiya, T; Onoguchi, K; Oshiumi, M; Takeuchi, S

    2000-06-01

    Three female patients with aortic stenosis associated with a severely small annulus underwent aortic valve replacement. In intraoperative measurements, a 19-mm obtulator could not pass through the aortic annulus in each case. We therefore concluded that it would be difficult to implant an appropriate-sized prosthesis in a routine fashion, so we performed an annular enlargement in a modified Nicks procedure. By using a wide teardrop-shaped patch for enlargement and slightly tilting insertion of a prosthesis, a 21 mm bileaflet mechanical prosthesis could be inserted into the enlarged annulus. Despite being a simpler method than other enlarging procedures, a two- or three-sizes larger prosthesis than the native annulus can be inserted with relative ease. Thus, the use of a 19 mm mechanical prosthesis may be avoidable in most adult cases.

  10. Timing in resolution of left heart dilation according to the degree of mitral regurgitation in children with ventricular septal defect after surgical closure

    Directory of Open Access Journals (Sweden)

    Hwa Jin Cho

    2014-01-01

    Full Text Available OBJECTIVE: Children with ventricular septal defects (VSD can have chronic volume overload, which can result in changes of left heart echocardiographic parameters. To evaluate the changes before and after surgical closure, the children were divided into three groups according to the degree of mitral regurgitation (MR, and their echocardiographic characteristics were reviewed at serial follow-up after surgical closure. METHODS: The preoperative, and one-, three-, and 12-month postoperative echocardiographic data of 40 children who underwent surgical closure of VSD were retrospectively reviewed. Left ventricular end-diastolic volume (LVEDV, left ventricular end-diastolic dimension (LVEDD, left ventricular end-systolic dimension (LVESD, mitral valvular characteristics, including degree of MR and mitral valve annulus, and left atrial (LA characteristics, including volume and dimensions, were observed. RESULTS: Preoperative LVEDV, LVEDD, LVESD, mitral valvular annulus, LA volume, and LA dimensions were significantly larger in children with MR. Additionally, there were significant decreases in LVEDV, LVEDD, LA volume, and LA dimensions at one, three, and 12 months postoperatively. The degree of MR also improved to a lower grade after surgical closure of the VSD without additional mitral valve repair. CONCLUSION: The echocardiographic parameters of left heart dilation and MR in children with VSD improved within the first year after surgical closure without additional mitral valve repair. Furthermore, in all of the patients with VSD, regardless of MR, LA dilation was reduced within three months after surgical closure of the VSD; however, LV and mitral valve annular dilatation decreased within 12 months.

  11. Some exploratory experiments with a new type of rotating, differentially-heated fluid annulus

    OpenAIRE

    Davies, Peter A; Walin, Gösta

    2011-01-01

    Some experiments with a rotating differentially heated annulus are presented. It is demonstrated that with suitable construction of the annulus the strength of the zonal baroclinic motion may be chosen independently of the basic density stratification. In the experiment reported it was found that baroclinic instability occurred in a state characterized by small isotherm slopes. Certain aspects of the observed flow and temperature fields—in particular the basic stratification and the slope of ...

  12. Assessment of the frequency of sperm annulus defects in a large cohort of patients presenting asthenozoospermia

    OpenAIRE

    Dirami, Thassadite; Rode, Baptiste; Wolf, Jean-Philippe; Gacon, Gérard; Dulioust, Emmanuel; Touré, Aminata

    2015-01-01

    International audience; Background: The annulus is a ring-shaped structure located beneath the plasma membrane that connects the midpiece and the principal piece of mammalian sperm flagellum. It has been suggested that the annulus acts as a morphological organizer, guiding flagellum assembly during spermiogenesis, and as a diffusion barrier, confining proteins to distinct compartments of the flagellum in mature sperm. Previous studies on small cohorts of patients have attempted to correlate a...

  13. Collagen fibrillogenesis in the development of the annulus fibrosus of the intervertebral disc.

    Science.gov (United States)

    Hayes, Anthony J; Isaacs, Marc D; Hughes, C; Caterson, B; Ralphs, J R

    2011-10-11

    The annulus fibrosus of the intervertebral disc is a complex, radial-ply connective tissue consisting of concentric lamellae of oriented collagen. Whilst much is known of the structure of the mature annulus, less is known of how its complex collagenous architecture becomes established; an understanding of which could inform future repair/regenerative strategies. Here, using a rat disc developmental series, we describe events in the establishment of the collagenous framework of the annulus at light and electron microscopic levels and examine the involvement of class I and II small leucine rich proteoglycans (SLRPs) in the matrix assembly process. We show that a period of sustained, ordered matrix deposition follows the initial cellular differentiation/orientation phase within the foetal disc. Fibrillar matrix is deposited from recesses within the plasma membrane into compartments of interstitial space within the outer annulus - the orientation of the secreted collagen reflecting the initial cellular orientation of the laminae. Medially, we demonstrate the development of a reinforcing 'cage' of collagen fibre bundles around the foetal nucleus pulpous. This derives from the fusion of collagen bundles between presumptive end-plate and inner annulus. By birth, the distinct collagenous architectures are established and the disc undergoes considerable enlargement to maturity. We show that fibromodulin plays a prominent role in foetal development of the annulus and its attachment to vertebral bodies. With the exception of keratocan, the other SLRPs appear associated more with cartilage development within the vertebral column, but all become more prominent within the disc during its growth and differentiation.

  14. Quantifying the contributions of structure to annulus fibrosus mechanical function using a nonlinear, anisotropic, hyperelastic model.

    Science.gov (United States)

    Guerin, Heather Lynch; Elliott, Dawn M

    2007-04-01

    The annulus fibrosus of the intervertebral disc is comprised of concentric lamella of oriented collagen fibers embedded in a hydrated proteoglycan matrix with smaller amounts of minor collagens, elastin, and small proteoglycans. Its structure and composition enable the disc to withstand complex loads and result in inhomogeneous, anisotropic, and nonlinear mechanical behaviors. The specific contributions of the annulus fibrosus constituent structures to mechanical function remain unclear. Therefore, the objective of this study was to use a structurally motivated, anisotropic, nonlinear strain energy model of annulus fibrosus to determine the relative contributions of its structural components to tissue mechanical behavior. A nonlinear, orthotropic hyperelastic model was developed for the annulus fibrosus. Terms to describe fibers, matrix, and interactions between annulus fibrosus structures (shear and normal to the fiber directions) were explicitly included. The contributions of these structures were analyzed by including or removing terms and determining the effect on the fit to multidimensional experimental data. Correlation between experimental and model-predicted stress, a Bland-Altman analysis of bias and standard deviation of residuals, and the contribution of structural terms to overall tissue stress were calculated. Both shear and normal interaction terms were necessary to accurately model multidimensional behavior. Inclusion of shear interactions more accurately described annulus fibrosus nonlinearity. Fiber stretch and shear interactions dominated contributions to circumferential direction stress, while normal and shear interactions dominated axial stress. The results suggest that interactions between fibers and matrix, perhaps facilitated by crosslinks, elastin, or minor collagens, augment traditional (i.e., fiber-uncrimping) models of nonlinearity.

  15. Loewner Theory in annulus I: evolution families and differential equations

    CERN Document Server

    Contreras, Manuel D; Gumenyuk, Pavel

    2010-01-01

    Loewner Theory, based on dynamical viewpoint, is a powerful tool in Complex Analysis, which plays a crucial role in such important achievements as the proof of famous Bieberbach's conjecture and well-celebrated Schramm's Stochastic Loewner Evolution (SLE). Recently Bracci et al [Bracci et al, to appear in J. Reine Angew. Math. Available on ArXiv 0807.1594; Bracci et al, Math. Ann. 344(2009), 947--962; Contreras et al, Revista Matematica Iberoamericana 26(2010), 975--1012] have proposed a new approach bringing together all the variants of the (deterministic) Loewner Evolution in a simply connected reference domain. We construct an analogue of this theory for the annulus. In this paper, the first of two articles, we introduce a general notion of an evolution family over a system of annuli and prove that there is a 1-to-1 correspondence between such families and semicomplete weak holomorphic vector fields. Moreover, in the non-degenerate case, we establish a constructive characterization of these vector fields a...

  16. A Novel Method for Repeatable Failure Testing of Annulus Fibrosus.

    Science.gov (United States)

    Werbner, Benjamin; Zhou, Minhao; O'Connell, Grace

    2017-11-01

    Tears in the annulus fibrosus (AF) of the intervertebral disk can result in disk herniation and progressive degeneration. Understanding AF failure mechanics is important as research moves toward developing biological repair strategies for herniated disks. Unfortunately, failure mechanics of fiber-reinforced tissues, particularly tissues with fibers oriented off-axis from the applied load, is not well understood, partly due to the high variability in reported mechanical properties and a lack of standard techniques ensuring repeatable failure behavior. Therefore, the objective of this study was to investigate the effectiveness of midlength (ML) notch geometries in producing repeatable and consistent tissue failure within the gauge region of AF mechanical test specimens. Finite element models (FEMs) representing several notch geometries were created to predict the location of bulk tissue failure using a local strain-based criterion. FEM results were validated by experimentally testing a subset of the modeled specimen geometries. Mechanical testing data agreed with model predictions (∼90% agreement), validating the model's predictive power. Two of the modified dog-bone geometries ("half" and "quarter") effectively ensured tissue failure at the ML for specimens oriented along the circumferential-radial and circumferential-axial directions. The variance of measured mechanical properties was significantly lower for notched samples that failed at the ML, suggesting that ML notch geometries result in more consistent and reliable data. In addition, the approach developed in this study provides a framework for evaluating failure properties of other fiber-reinforced tissues, such as tendons and meniscus.

  17. Thermoconvective vortices in a cylindrical annulus with varying inner radius.

    Science.gov (United States)

    Castaño, D; Navarro, M C; Herrero, H

    2014-12-01

    This paper shows the influence of the inner radius on the stability and intensity of vertical vortices, qualitatively similar to dust devils and cyclones, generated in a cylindrical annulus non-homogeneously heated from below. Little relation is found between the intensity of the vortex and the magnitude of the inner radius. Strong stable vortices can be found for both small and large values of the inner radius. The Rankine combined vortex structure, that characterizes the tangential velocity in dust devils, is clearly observed when small values of the inner radius and large values of the ratio between the horizontal and vertical temperature differences are considered. A contraction on the radius of maximum azimuthal velocity is observed when the vortex is intensified by thermal mechanisms. This radius becomes then nearly stationary when frictional force balances the radial inflow generated by the pressure drop in the center, despite the vortex keeps intensifying. These results connect with the behavior of the radius of the maximum tangential wind associated with a hurricane.

  18. The myth of closure.

    Science.gov (United States)

    Boss, Pauline; Carnes, Donna

    2012-12-01

    Therapies for grief and loss have traditionally focused on the work of grieving. The goal was to reach an endpoint, now popularly called closure. There are, however, many people who, through no fault of their own, find a loss so unclear that there can be no end to grief. They have not failed in the work of grieving, but rather have suffered ambiguous loss, a type of loss that is inherently open ended. Instead of closure, the therapeutic goal is to help people find meaning despite the lack of definitive information and finality. Hope lies in increasing a family's tolerance for ambiguity, but first, professionals must increase their own comfort with unanswered questions. In this article, the authors, one a poet, the other a family therapist and theorist, offer a unique blending of theory, reflection, and poetry to experientially deepen the process of self-reflection about a kind of loss that defies closure. © FPI, Inc.

  19. Safety assessment and risk-benefit analysis of the use of azodicarbonamide in baby food jar closure technology: putting trace levels of semicarbazide exposure into perspective--a review.

    Science.gov (United States)

    Nestmann, E R; Lynch, B S; Musa-Veloso, K; Goodfellow, G H; Cheng, E; Haighton, L A; Lee-Brotherton, V M

    2005-09-01

    The discovery of trace levels of semicarbazide (SEM) in bottled foods (especially baby foods) led to a consideration of the safety of this hydrazine compound by regulatory agencies worldwide. Azodicarbonamide, which is used in the jar-sealing technology known as Press On-Twist Off (or Push-Twist/PT) closures for the formation of a hermetic, plastisol seal, partially degrades with the heat of processing to form trace amounts of SEM. This review has evaluated the potential toxicological risks of resulting exposure to SEM and also the benefit of the PT technology (with azodicarbonamide) in the context of possible microbial contamination. It also considers the potential impact on infant nutrition if parents come to the conclusion that commercial baby foods are unsafe. SEM shows limited genotoxicity in vitro that is largely prevented by the presence of mammalian metabolic enzymes. Negative results were found in vivo in DNA alkaline elution, unscheduled DNA synthesis and micronucleus assays. This pattern is in contrast to the genotoxic hydrazines that also have been shown to cause tumours. Carcinogenicity studies of SEM are of limited quality, show a questionable weak effect in mice at high doses, which are not relevant to human exposure at trace levels, and show no effect in the rat. The IARC has assigned SEM as Group 3, 'Not classifiable as to its carcinogenicity to humans'. Based on estimates of exposure to infants consuming baby foods (with the assumption of SEM levels at the 95th percentile of 20 ng g(-1) in all of the consumed 'ready-to-eat' foods) compared with a no observed adverse effect level (NOAEL) in developmental toxicity studies, the margin of safety is more than 21 000. Since the risk of an adverse effect is negligible, it is clear that any theoretical risk is outweighed by the benefits of continuing use of the PT closure (with azodicarbonamide blowing agent) to ensure both the microbial integrity and availability of commercial baby foods as a valuable

  20. Mail Office annual closure

    CERN Multimedia

    2013-01-01

    On the occasion of the annual closure of CERN, there will be no mail distributed on Friday 20 December 2013 but mail will be collected in the morning. Nevertheless, you will still be able to bring your outgoing mail to Building 555-R-002 until 12 noon.  

  1. MNC Subsidiary Closure

    DEFF Research Database (Denmark)

    de Faria, Pedro; Preto, Miguel Torres; Sofka, Wolfgang

    2013-01-01

    We investigate the consequences of MNC subsidiary closures for employees who lose their jobs. We ask to what degree the foreign knowledge that they were exposed to is valued in their new job. We argue theoretically that this foreign knowledge is both valuable and not readily available in the host...

  2. MNC Subsidiary Closure

    DEFF Research Database (Denmark)

    de Faria, Pedro; Sofka, Wolfgang; Torres Preto, Miguel

    We investigate the consequences of MNC subsidiary closures for employees who lose their jobs. We ask to what degree the foreign knowledge that they were exposed to is valued in their new job. We argue theoretically that this foreign knowledge is both valuable and not readily available in the host...

  3. Quantification of aortic annulus in computed tomography angiography: Validation of a fully automatic methodology.

    Science.gov (United States)

    Gao, Xinpei; Boccalini, Sara; Kitslaar, Pieter H; Budde, Ricardo P J; Attrach, Mohamed; Tu, Shengxian; de Graaf, Michiel A; Ondrus, Tomas; Penicka, Martin; Scholte, Arthur J H A; Lelieveldt, Boudewijn P F; Dijkstra, Jouke; Reiber, Johan H C

    2017-08-01

    Automatic accurate measuring of the aortic annulus and determination of the optimal angulation of X-ray projection are important for the trans-catheter aortic valve replacement (TAVR) procedure. The objective of this study was to present a novel fully automatic methodology for the quantification of the aortic annulus in computed tomography angiography (CTA) images. CTA datasets of 26 patients were analyzed retrospectively with the proposed methodology, which consists of a knowledge-based segmentation of the aortic root and detection of the orientation and size of the aortic annulus. The accuracy of the methodology was determined by comparing the automatically derived results with the reference standard obtained by semi-automatic delineation of the aortic root and manual definition of the annulus plane. The difference between the automatic annulus diameter and the reference standard by observer 1 was 0.2±1.0mm, with an inter-observer variability of 1.2±0.6mm. The Pearson correlation coefficient for the diameter was good (0.92 for observer 1). For the first time, a fully automatic tool to assess the optimal projection curves was presented and validated. The mean difference between the optimal projection curves calculated based on the automatically defined annulus plane and the reference standard was 6.4° in the cranial/caudal (CRA/CAU) direction. The mean computation time was short with around 60s per dataset. The new fully automatic and fast methodology described in this manuscript not only provided precise measurements about the aortic annulus size with results comparable to experienced observers, but also predicted optimal X-ray projection curves from CTA images. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Ring closure in actin polymers

    Science.gov (United States)

    Sinha, Supurna; Chattopadhyay, Sebanti

    2017-03-01

    We present an analysis for the ring closure probability of semiflexible polymers within the pure bend Worm Like Chain (WLC) model. The ring closure probability predicted from our analysis can be tested against fluorescent actin cyclization experiments. We also discuss the effect of ring closure on bend angle fluctuations in actin polymers.

  5. Knockdown of asporin affects transforming growth factor-β1-induced matrix synthesis in human intervertebral annulus cells

    Directory of Open Access Journals (Sweden)

    Xu Jiang

    2016-10-01

    Conclusion: Our results have verified a functional feedback loop between TGF-β1 and asporin in human intervertebral annulus cells indicating that TGF-β1-induced annulus matrix biosynthesis can be significantly upregulated by knockdown of asporin. Therefore, asporin could be a potential new therapeutic target and inhibition of asporin could be adopted to enhance the anabolic effect of TGF-β1 in human intervertebral annulus cells in degenerative IVD diseases.

  6. A case against closure

    Directory of Open Access Journals (Sweden)

    Olin, Doris

    2005-01-01

    Full Text Available Este artigo examina a objeção ao fechamento [dedutivo] que surge no contexto de certos paradoxos epistêmicos, paradoxos cuja conclusão é que a crença justificada pode ser inconsistente. É universalmente aceito que, se essa conclusão é correta, o fechamento deve ser rejeitado, para que se evite a crença justificada em enunciados contraditórios (P, ~P. Mas, mesmo que os argumentos desses paradoxos - o paradoxo da falibilidade (do prefácio e o paradoxo da loteria - seja mal sucedidos, eles, ainda assim, sugerem a existência de evidência independente para uma objeção mais direta contra o fechamento. O exame do argumento da falibilidade revela uma exigência de modéstia epistêmica que viola o fechamento a partir de múltiplas premissas. A reflexão sobre o paradoxo da loteria nos confronta com um dilema em que cada alternativa fornece um contra-exemplo ao fechamento a partir de uma única premissa. Seja ou não possível a inconsistência racional, há uma objeção contra o fechamento. This paper examines the case against closure that arises in the context of certain epistemic paradoxes, paradoxes whose conclusion is that it is possible for justified belief to be inconsistent. It is generally agreed that if this conclusion is correct, closure must be rejected in order to avoid justified belief in contradictory statements (P, ~P. But even if the arguments of these paradoxes – the fallibility (preface paradox and the lottery paradox – are unsuccessful, they nonetheless suggest independent grounds for a more direct case against closure. Examination of the fallibility argument reveals a requirement of epistemic modesty that violates multiple premise closure. Reflection on the lottery paradox presents us with a dilemma in which each alternative provides a counterexample to single premise closure. Whether or not rational inconsistency is possible, there is a case against closure.

  7. Simultaneous PIV and thermography measurements of partially blocked flow in a differentially heated rotating annulus

    Energy Technology Data Exchange (ETDEWEB)

    Harlander, Uwe; Alexandrov, Kiril; Wang, Yongtai; Egbers, Christoph [Brandenburg University of Technology Cottbus, Department of Aerodynamics and Fluid Mechanics, Cottbus (Germany); Wenzel, Julia [University of Leipzig, Institute of Meteorology, Leipzig (Germany)

    2012-04-15

    A radial barrier has been mounted in a differentially heated rotating annulus that partially blocks the azimuthal flow component. The experiment can be seen as an analog to geophysical flows with constrictions, e.g., the Antarctic Circumpolar Current. However, the experiment has been carried out without a particular natural flow in mind. The main interest was to observe a baroclinic annulus flow that does not become saturated. Hence, in contrast to the annulus flow without a barrier, the partially blocked flow remains transient and surface heat fluxes associated with baroclinic life cycles can be studied. The annulus can be subdivided into the upstream half of the barrier, where waves amplify, and the downstream half of the barrier, where waves decay. In the upstream half, the azimuthal mean flow is moderate but with a significant positive eddy radial heat flux. In the downstream half, we find a strong jet in the mean azimuthal flow and furthermore an increased radial mean temperature gradient. The latter points to a weakened or even reversed radial eddy heat flux in the lee side of the barrier. Temperature anomalies appear as large bulges in the outer part of the annulus. Moreover, an outward shift of vortex centers can be observed with respect to centers of temperature anomalies. This phase shift between pressure and temperature anomalies differs from that of classical Eady modes of baroclinic instability. (orig.)

  8. Study on Flow Characteristic of Non-Newtonian fluid in Eccentric Annulus

    Directory of Open Access Journals (Sweden)

    Li Mingzhong

    2013-08-01

    Full Text Available This study studied the flow characteristic of non-newtonian in eccentric annulus of highly-deviated well. On the basis of dimensionless analysis of motion equations and continuity equation, Hele-Shaw model suitable for fluid flow in the annulus was derived. Combined with H-B rheological model, velocity and stream distribution model were founded and calculated by numerical method. Furthermore, two-dimensional flow characteristic in eccentric annulus was got and the influence of different factors (such as yield stress, pressure gradient or eccentricity on velocity distribution in condition of laminar flow was analyzed. Width of flow core in the annular is proportional to yield stress and inversely proportional to pressure gradient. In eccentric annulus, eccentricity influences the stream distribution remarkably: with the increment of eccentricity, the contour lines of stream function gradually centralize in the widest annular gap, however distribute the most loosely in the narrowest annular gap. Axial velocity is the largest in the widest gap. The larger eccentricity is, the larger contrast of axial velocity between in the widest gap and in the narrowest gap is. There is the largest azimuthal velocity in an annular gap of a certain azimuthal angle, however which equals to zero in the widest and narrowest annular gap separately. The larger eccentricity is, the more homogeneous azimuthal velocity is. The velocity contrast in the entire annulus can be smoothed by increasing pressure gradient, power law index or decreasing yield stress.

  9. Aortic Valve Leaflet Replacement with Bovine Pericardium to Preserve Native Dynamic Capabilities of the Aortic Annulus

    Science.gov (United States)

    Kim, Kyung Hwa; Kim, Min Ho; Kim, Won Ho; Lee, Mi Kyung; Lee, Sam Youn

    2014-01-01

    Valve replacement is typically the most appropriate option for treating aortic valve stenotic insufficiency. However, neither mechanical nor bioprosthetic replacement components preserve the circumferential expansion and contraction of a native aortic annulus during the cardiac cycle, because the prosthetic ring is affixed to the annulus. A 64-year-old man presented with a bicuspid and stenotic aortic valve, and the native annulus was too small to accommodate a porcine replacement valve. We fashioned new aortic leaflets from bovine pericardium with use of a template, and we affixed the sinotubular junction with use of inner and outer stabilization rings. Postoperative echocardiograms revealed coaptation of the 3 new leaflets with no regurgitation. At the patient's 5.5-year follow-up examination, echocardiograms showed flexible leaflet movement with a coaptation height of 7 mm, and expansion and contraction of the aortic annulus similar to that of a normal native annulus. The transvalvular pressure gradient was insignificant. If long-term durability of the new leaflets is confirmed, this method of leaflet replacement and fixation of the sinotubular junction might serve as an acceptable alternative to valve replacement in the treatment of aortic valve stenosis. We describe the patient's case and present our methods and observations. PMID:24512414

  10. Aortic valve leaflet replacement with bovine pericardium to preserve native dynamic capabilities of the aortic annulus.

    Science.gov (United States)

    Kim, Kyung Hwa; Choi, Jong Bum; Kim, Min Ho; Kim, Won Ho; Lee, Mi Kyung; Lee, Sam Youn

    2014-02-01

    Valve replacement is typically the most appropriate option for treating aortic valve stenotic insufficiency. However, neither mechanical nor bioprosthetic replacement components preserve the circumferential expansion and contraction of a native aortic annulus during the cardiac cycle, because the prosthetic ring is affixed to the annulus. A 64-year-old man presented with a bicuspid and stenotic aortic valve, and the native annulus was too small to accommodate a porcine replacement valve. We fashioned new aortic leaflets from bovine pericardium with use of a template, and we affixed the sinotubular junction with use of inner and outer stabilization rings. Postoperative echocardiograms revealed coaptation of the 3 new leaflets with no regurgitation. At the patient's 5.5-year follow-up examination, echocardiograms showed flexible leaflet movement with a coaptation height of 7 mm, and expansion and contraction of the aortic annulus similar to that of a normal native annulus. The transvalvular pressure gradient was insignificant. If long-term durability of the new leaflets is confirmed, this method of leaflet replacement and fixation of the sinotubular junction might serve as an acceptable alternative to valve replacement in the treatment of aortic valve stenosis. We describe the patient's case and present our methods and observations.

  11. Technical assistance to Ohio closure sites; Technologies to address leachate from the on-site disposal facility at Fernald Environmental Management Project, Ohio

    Energy Technology Data Exchange (ETDEWEB)

    Hazen, Terry

    2002-08-26

    On August 6-7, 2002, a Technical Assistance Team (''Team'') from the U.S. Department of Energy (DOE) Subsurface Contaminants Focus Area (SCFA) met with Fernald Environmental Management Project (FEMP) personnel in Ohio to assess approaches to remediating uranium-contaminated leachate from the On-Site Disposal Facility (OSDF). The Team was composed of technical experts from national labs, technology centers, and industry and was assembled in response to a request from the FEMP Aquifer Restoration Project. Dave Brettschneider of Fluor Fernald, Inc., requested that a Team of experts be convened to review technologies for the removal of uranium in both brine ion exchange regeneration solution from the Advanced Wastewater Treatment facility and in the leachate from the OSDF. The Team was asked to identify one or more technologies for bench-scale testing as a cost effective alternative to remove uranium so that the brine regeneration solution from the Advanced Waste Water Treatment facility and the leachate from the OSDF can be discharged without further treatment. The Team was also requested to prepare a recommended development and demonstration plan for the alternative technologies. Finally, the Team was asked to make recommendations on the optimal technical solution for field implementation. The Site's expected outcomes for this effort are schedule acceleration, cost reduction, and better long-term stewardship implementation. To facilitate consideration of the most appropriate technologies, the Team was divided into two groups to consider the brine and the leachate separately, since they represent different sources with different constraints on solutions, e.g., short-term versus very long-term and concentrated versus dilute contaminant matrices. This report focuses on the technologies that are most appropriate for the leachate from the OSDF. Upon arriving at FEMP, project personnel asked the Team to concentrate its efforts on evaluating

  12. Summer season | Cafeteria closures

    CERN Multimedia

    2013-01-01

    Please note the following cafeteria closures over the summer season: Bldg. 54 closed from 29/07/2013 to 06/09/2013. Bldg. 13: closed from 13/07/2013 to 06/09/2013. Restaurant No. 2, table service (brasserie and restaurant): closed from 01/08/2013 to 06/09/2013. Bldg. 864: closed from 29/07/2013 to 06/09/2013. Bldg. 865: closed from 29/07/2013 to 06/09/2013.

  13. Summer season | Cafeteria closures

    CERN Multimedia

    2013-01-01

    Please note the following cafeteria closures over the summer season: Bldg. 54 closed from 29/07/2013 to 06/09/2013. Bldg. 13: closed from 13/07/2013 to 06/09/2013. Restaurant No. 2, table service (brasserie and restaurant): closed from 01/08/2013 to 06/09/2013. Bldg. 864: closed from 29/07/2013 to 06/09/2013. Bldg. 865: closed from 29/07/2013 to 06/09/2013.

  14. RELAP-7 Closure Correlations

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Ling [Idaho National Lab. (INL), Idaho Falls, ID (United States); Berry, R. A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Martineau, R. C. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Andrs, D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, H. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hansel, J. E. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Sharpe, J. P. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Johns, Russell C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-04-01

    The RELAP-7 code is the next generation nuclear reactor system safety analysis code being developed at the Idaho National Laboratory (INL). The code is based on the INL’s modern scientific software development framework, MOOSE (Multi-Physics Object Oriented Simulation Environment). The overall design goal of RELAP-7 is to take advantage of the previous thirty years of advancements in computer architecture, software design, numerical integration methods, and physical models. The end result will be a reactor systems analysis capability that retains and improves upon RELAP5’s and TRACE’s capabilities and extends their analysis capabilities for all reactor system simulation scenarios. The RELAP-7 code utilizes the well-posed 7-equation two-phase flow model for compressible two-phase flow. Closure models used in the TRACE code has been reviewed and selected to reflect the progress made during the past decades and provide a basis for the colure correlations implemented in the RELAP-7 code. This document provides a summary on the closure correlations that are currently implemented in the RELAP-7 code. The closure correlations include sub-grid models that describe interactions between the fluids and the flow channel, and interactions between the two phases.

  15. History of Sandia National Laboratories` auxiliary closure mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Weydert, J.C. [Sandia National Labs., Albuquerque, NM (United States); Ponder, G.M. [Geo-Centers, Inc., Albuquerque, NM (United States)

    1993-12-01

    An essential component of a horizontal, underground nuclear test setup at the Nevada Test Site is the auxiliary closure system. The massive gates that slam shut immediately after a device has been detonated allow the prompt radiation to pass, but block debris and hot gases from continuing down the tunnel. Thus, the gates protect experiments located in the horizontal line-of-sight steel pipe. Sandia National Laboratories has been the major designer and developer of these closure systems. This report records the history of SNL`s participation in and contributions to the technology of auxiliary closure systems used in horizontal tunnel tests in the underground test program.

  16. Technical Information to Support Double Shell Tank (DST) Emergency Annulus Pumping [SEC 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    REBERGER, D.W.

    2000-09-14

    This document provides the design calculations for the DST Annulus Emergency Pumping Project. This document also contains essential information relative to DST annulus emergency pumping that may not be found in other documents. This information consists of the following: Index drawing for annulus pumping; References to the Acceptance Test Report, DST Emergency Pumping Guide, Time Deployment study, etc.; Statements of work; and Reference CEIS and RMIS numbers. A Vendor Information document, VI-50121, is not included in this document, but a copy can be obtained by contacting Document Control Services. This document contains various information regarding the Hydrostar pumps, such as the air motor, cylinder size, pump installation and operation manual. It also contains information regarding the Flygt BS2060 submersible pump, such as parts list, pump handling, preventative maintenance, overhaul and repair. In addition, this document also has information on 3-way PM ball valves, electrical skid components and the alternate Gurman-Rupp stainless steel submersible pump.

  17. [Surgical technique of aortic valve replacement for small aortic annulus in elderly patients].

    Science.gov (United States)

    Hata, T; Fujiwara, K; Furukawa, H; Tsushima, Y; Yoshitaka, H; Kuinose, M; Minami, H; Ishida, A; Tamura, K; Totsugawa, T; Kanemitsu, H; Ozawa, M

    2006-04-01

    Recent reports have shown that aortic valve replacement in elderly patients over 65 years with atherosclerotic aortic stenosis and a small aortic annulus is possible by using a small sized bioprosthesis (Carpentier-Edwards pericardial valve). Here we present out surgical technique. Firstly, the native calcified aortic valve was removed completely to gain total exposure of the surrounding aortic root and sinus of Valsalva like Bentall procedure. Secondly, a small sized bioprosthesis was implanted with intermittent noneverting mattress 2-0 sutures with spaghetti and small polytetrafluoroethylene (PTFE) felt. Aortic annulus is the dilated by inserting Hegar dilator sizing from 25 to 27 mm. Therefore, aortic valve replacement for small aortic annulus in intra- or supra-annular position should be easily accomplished. Good surgical results and hemodynamic state were achieved in 25 consecutive cases using this technique.

  18. Flow resistance characteristics of water in narrow annulus during heat exchange

    Institute of Scientific and Technical Information of China (English)

    SUN Li-cheng; YAN Chang-qi; SUN Zhong-ning; ZHANG Qing-hua

    2003-01-01

    Considering the special resistance characteristics of fluids flowing through ducts with small gaps, experiments are performed to investigate the resistance characteristics of single-phase water, which is forced to flow through vertical annuli. The gap sizes are 0.9, 1.4 and 2.4mm, respectively. The experiments are conducted under condition of 1atm. The water in the annuli is heated by high temperature water reversely flowing through the inner tube and the outer annulus. The results show that the flow pattern begin to change from laminar to turbulent before Reynolds number approaches 2000, the flow resistance in annulus has little relations with the temperature difference and ways of being heated, but mainly depends on the ratio of mass flux to the width of annulus.

  19. Regimes of Axisymmetric Flow and Scaling Laws in a Rotating Annulus with Local Convective Forcing

    Directory of Open Access Journals (Sweden)

    Susie Wright

    2017-07-01

    Full Text Available We present a numerical study of axisymmetric flow in a rotating annulus in which local thermal forcing, via a heated annular ring on the outside of the base and a cooled circular disk in the centre of the top surface, drives convection. This new configuration is a variant of the classical thermally-driven annulus, where uniform heating and cooling are applied through the outer and inner sidewalls respectively. The annulus provides an analogue to a planetary circulation and the new configuration, with its more relaxed vertical thermal boundary conditions, is expected to better emulate vigorous convection in the tropics and polar regions as well as baroclinic instability in the mid-latitude baroclinic zone. Using the Met Office/Oxford Rotating Annulus Laboratory (MORALS code, we have investigated a series of equilibrated, two dimensional axisymmetric flows across a large region of parameter space. These are characterized in terms of their velocity and temperature fields. When rotation is applied several distinct flow regimes may be identified for different rotation rates and strengths of differential heating. These regimes are defined as a function of the ratio of the horizontal Ekman layer thickness to the non-rotating thermal boundary layer thickness and are found to be similar to those identified in previous annulus experiments. Convection without rotation is also considered and the scaling of the heat transport with Rayleigh number is calculated. This is then compared with existing work on the classical annulus as well as horizontal and Rayleigh-Bénard convection. As with previous studies on both rotating and non-rotating convection the system’s behaviour is found to be aspect ratio dependent. This dependence is seen in the scaling of the non-rotating Nusselt number and in transitions between regimes in the rotating case although further investigation is required to fully explain these observations.

  20. Collagen fibrillogenesis in the development of the annulus fibrosus of the intervertebral disc

    Directory of Open Access Journals (Sweden)

    AJ Hayes

    2011-10-01

    Full Text Available The annulus fibrosus of the intervertebral disc is a complex, radial-ply connective tissue consisting of concentric lamellae of oriented collagen. Whilst much is known of the structure of the mature annulus, less is known of how its complex collagenous architecture becomes established; an understanding of which could inform future repair/regenerative strategies. Here, using a rat disc developmental series, we describe events in the establishment of the collagenous framework of the annulus at light and electron microscopic levels and examine the involvement of class I and II small leucine rich proteoglycans (SLRPs in the matrix assembly process. We show that a period of sustained, ordered matrix deposition follows the initial cellular differentiation/orientation phase within the foetal disc. Fibrillar matrix is deposited from recesses within the plasma membrane into compartments of interstitial space within the outer annulus – the orientation of the secreted collagen reflecting the initial cellular orientation of the laminae. Medially, we demonstrate the development of a reinforcing ‘cage’ of collagen fibre bundles around the foetal nucleus pulpous. This derives from the fusion of collagen bundles between presumptive end-plate and inner annulus. By birth, the distinct collagenous architectures are established and the disc undergoes considerable enlargement to maturity. We show that fibromodulin plays a prominent role in foetal development of the annulus and its attachment to vertebral bodies. With the exception of keratocan, the other SLRPs appear associated more with cartilage development within the vertebral column, but all become more prominent within the disc during its growth and differentiation.

  1. Two-Dimensional Echo-cardiographic Estimation of the Size of the Mitral Valve Annulus

    Directory of Open Access Journals (Sweden)

    Shigenobu,Masaharu

    1982-12-01

    Full Text Available The diameter of the mitral annulus as measured on the long axis by two-dimensional echocardiogram was found to correlate well with the size of the sewing ring used to replace the mitral valve in 35 consecutive patients. The size of the prosthesis which was used could be predicted within 1 mm of error in 83% of the mitral stenosis (MS patients and in 76% of the mitral regurgitation (MR patients in the study. Preoperative echocardiographic estimation of the size of the mitral valve annulus and prediction of the sewing ring size of the prosthetic valve used could reduce the incidence of valve prosthesis-patient mismatch.

  2. Extraordinary acoustic transmission through annuluses in air and its applications in acoustic beam splitter and concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Yong; Liu, Shu-sen; Yuan, Shou-qi, E-mail: Shouqiy@ujs.edu.cn; Xia, Jian-ping; Guan, Yi-jun [Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013 (China); Sun, Hong-xiang, E-mail: jsdxshx@ujs.edu.cn [Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013 (China); Lab of Modern Acoustics, Institute of Acoustics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190 (China); Zhang, Shu-yi [Lab of Modern Acoustics, Institute of Acoustics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China)

    2016-08-15

    We report an extraordinary acoustic transmission through two layer annuluses made of metal cylinders in air both numerically and experimentally. The effect arises from the enhancement and reconstruction of the incident source induced by different Mie-resonance modes of the annuluses. The proposed system takes advantages of the consistency in the waveform between the input and output waves, the high amplitude amplification of output waves, and the easy adjustment of structure. More interestingly, we investigate the applications of the extraordinary acoustic transmission in the acoustic beam splitter and acoustic concentrator. Our finding should have an impact on ultrasonic applications.

  3. 40 CFR 265.280 - Closure and post-closure.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Closure and post-closure. 265.280 Section 265.280 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES... location, topography, and surrounding land use, with respect to the potential effects of pollutant...

  4. FINAL CLOSURE PLAN SURFACE IMPOUNDMENTS CLOSURE, SITE 300

    Energy Technology Data Exchange (ETDEWEB)

    Lane, J E; Scott, J E; Mathews, S E

    2004-09-29

    Lawrence Livermore National Laboratory of the University of California (LLNL) operates two Class II surface impoundments that store wastewater that is discharged from a number of buildings located on the Site 300 Facility (Site 300). The wastewater is the by-product of explosives processing. Reduction in the volume of water discharged from these buildings over the past several years has significantly reduced the wastewater storage needs. In addition, the impoundments were constructed in 1984, and the high-density polyethylene (HDPE) geomembrane liners are nearing the end of their service life. The purpose of this project is to clean close the surface impoundments and provide new wastewater storage using portable, above ground storage tanks at six locations. The tanks will be installed prior to closure of the impoundments and will include heaters for allowing evaporation during relatively cool weather. Golder Associates (Golder) has prepared this Final Closure Plan (Closure Plan) on behalf of LLNL to address construction associated with the clean closure of the impoundments. This Closure Plan complies with State Water Resources Control Board (SWRCB) Section 21400 of the California Code of Regulations Title 27 (27 CCR {section}21400). As required by these regulations and guidance, this Plan provides the following information: (1) A site characterization, including the site location, history, current operations, and geology and hydrogeology; (2) The regulatory requirements relevant to clean closure of the impoundments; (3) The closure procedures; and, (4) The procedures for validation and documentation of clean closure.

  5. Background Independent Open String Field Theory with Constant B field On the Annulus

    CERN Document Server

    Rashkov, R; Yang, Y

    2001-01-01

    We study Witten's background independent open-string field theory in the presence of a constant B-field at one loop level. The Green's function and the partition function with a constant B-field are evaluated for an annulus.

  6. Aortic annulus and ascending aorta: Comparison of preoperative and periooperative measurement in patients with aortic stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Smid, Michal [Cardiology Department of Internal Medicine, School of Medicine Plzen, Charles University Prague and University Hospital Plzen, alej Svobody 80, 304 60 Plzen (Czech Republic)], E-mail: kosvin@seznam.cz; Ferda, Jiri [Department of Radiology, School of Medicine Plzen, Charles University Prague and University Hospital Plzen, alej Svobody 80, 304 60 Plzen (Czech Republic)], E-mail: ferda@fnplzen.cz; Baxa, Jan [Department of Radiology, School of Medicine Plzen, Charles University Prague and University Hospital Plzen, alej Svobody 80, 304 60 Plzen (Czech Republic)], E-mail: baxaj@fnplzen.cz; Cech, Jakub [Cardiology Department of Internal Medicine, School of Medicine Plzen, Charles University Prague and University Hospital Plzen, alej Svobody 80, 304 60 Plzen (Czech Republic)], E-mail: cechj@fnplzen.cz; Hajek, Tomas [Department of Cardiac Surgery, School of Medicine Plzen, Charles University Prague and University Hospital Plzen, alej Svobody 80, 304 60 Plzen (Czech Republic)], E-mail: hajekt@fnplzen.cz; Kreuzberg, Boris [Department of Radiology, School of Medicine Plzen, Charles University Prague and University Hospital Plzen, alej Svobody 80, 304 60 Plzen (Czech Republic)], E-mail: kreuzberg@fnplzen.cz; Rokyta, Richard [Cardiology Department of Internal Medicine, School of Medicine Plzen, Charles University Prague and University Hospital Plzen, alej Svobody 80, 304 60 Plzen (Czech Republic)], E-mail: rokyta@fnplzen.cz

    2010-04-15

    Background: Precise determination of the aortic annulus size constitutes an integral part of the preoperative evaluation prior to aortic valve replacement. It enables the estimation of the size of prosthesis to be implanted. Knowledge of the size of the ascending aorta is required in the preoperative analysis and monitoring of its dilation enables the precise timing of the operation. Our goal was to compare the precision of measurement of the aortic annulus and ascending aorta using magnetic resonance (MR), multidetector-row computed tomography (MDCT), transthoracic echocardiography (TTE), and transoesophageal echocardiography (TEE) in patients with degenerative aortic stenosis. Methods and results: A total of 15 patients scheduled to have aortic valve replacement were enrolled into this prospective study. TTE was performed in all patients and was supplemented with TEE, CT and MR in the majority of patients. The values obtained were compared with perioperative measurements. For the measurement of aortic annulus, MR was found to be the most precise technique, followed by MDCT, TTE, and TEE. For the measurement of ascending aorta, MR again was found to be the most precise technique, followed by MDCT, TEE, and TTE. Conclusion: In our study, magnetic resonance was found to be the most precise technique for the measurement of aortic annulus and ascending aorta in patients with severe degenerative aortic stenosis.

  7. Surface hydrogenation regulated wrinkling and torque capability of hydrogenated graphene annulus under circular shearing

    Science.gov (United States)

    Li, Yinfeng; Liu, Silin; Datta, Dibakar; Li, Zhonghua

    2015-11-01

    Wrinkles as intrinsic topological feature have been expected to affect the electrical and mechanical properties of atomically thin graphene. Molecular dynamics simulations are adopted to investigate the wrinkling characteristics in hydrogenated graphene annulus under circular shearing at the inner edge. The amplitude of wrinkles induced by in-plane rotation around the inner edge is sensitive to hydrogenation, and increases quadratically with hydrogen coverage. The effect of hydrogenation on mechanical properties is investigated by calculating the torque capability of annular graphene with varying hydrogen coverage and inner radius. Hydrogenation-enhanced wrinkles cause the aggregation of carbon atoms towards the inner edge and contribute to the critical torque strength of annulus. Based on detailed stress distribution contours, a shear-to-tension conversion mechanism is proposed for the contribution of wrinkles on torque capacity. As a result, the graphane annulus anomalously has similar torque capacity to pristine graphene annulus. The competition between hydrogenation caused bond strength deterioration and wrinkling induced local stress state conversion leads to a U-shaped evolution of torque strength relative to the increase of hydrogen coverage from 0 to 100%. Such hydrogenation tailored topological and mechanical characteristics provides an innovative mean to develop novel graphene-based devices.

  8. Structural analysis and evaluation of the 241SY101 tank annulus heat-up

    Energy Technology Data Exchange (ETDEWEB)

    Ziada, H.H.

    1994-10-19

    This document provides the structural analysis (static and thermal loads) of the 241SY101 tank to determine the maximum allowable temperature and rate of heating that could be applied to tank 241SY101 through annulus air heating without detrimental effects to the structural integrity of the concrete and steel liner of the tank.

  9. Three-Dimensional Numerical Simulation of Natural Convection Heat Transfer in an Inclined Cylindrical Annulus

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    A numerical study of natural convection beat transfer in an inclined cylindrical annulus has been conducted.The inner cylinder of the annulus is maintained at uniform heat flux and the outer cylinder at constant temperature.the two end walls are assumed to be insulated.A numerical code has been developed to calculate the steady state three-dimensional natural convection in an inclined cylindrical annulus,and the research emphasis is placed on the influences of inclination angle α and modified Rayleigh number Ra on the natural convection heat transfer in the annulus.Computations were carried out in the ranges of 0°≤α≤90*,2.5×105≤Ra*≤7and Pr=0.7 with fixed aspect ratio of H=28.97 and radius ratio of K=3.33,The numerical results are compared with the experimental correlations from the literature and the inclination angle effect on heat transfer is found to be insignificant.Detailed results of heat transfer rate,temperature,and velocity fields are presented for the case of α=45° and discussion is also made concerning the comparison between the numerical and experimental results for the specific case of α=90°。

  10. Polyak type equations for virtual arrow diagram formulas in the annulus

    OpenAIRE

    Mortier, Arnaud

    2012-01-01

    21 pages, 15 figures; We describe the space of arrow diagram formulas for virtual knot diagrams in the annulus as the kernel of a linear map, inspired from a conjecture due to M. Polyak. As a main application, we slightly improve Grishanov-Vassiliev's theorem for planar chain invariants.

  11. Heat Transfer in Tubing-Casing Annulus during Production Process of Geothermal Systems

    Institute of Scientific and Technical Information of China (English)

    Fuzong Zhou; Xiuhua Zheng

    2015-01-01

    In geothermal systems, the temperature distribution of heat flow in the wellbore is de-pendent on the well structure and the geological conditions of the surrounding formation. Under-standing of heat transfer in the tubing-casing annulus can reduce the heat losses of wellbore fluid during the production process. The present study discusses the possible means of heat transfer in the annulus, and develops a piecewise equation for estimating the convective heat transfer coefficient with a wider valid condition of 0annulus. The results indicate that the annulus filled with gas can be utilized as a good thermal barrier for the fluid in the wellbore. Additionally, the contribution of radiation will increase to occupy a majority proportion in the total thermal conductivity when the annular size increases and the materials have high emissivity. Otherwise, thermal radiation is just the second fac-tor.

  12. Mechanical restoration and failure analyses of a hydrogel and scaffold composite strategy for annulus fibrosus repair

    NARCIS (Netherlands)

    Long, Rose G.; Buerki, Alexander; Zysset, Philippe; Eglin, David; Grijpma, Dirk W.; Blanquer, Sebastien B. G.; Hecht, Andrew C.; Iatridis, James C.

    2016-01-01

    Unrepaired defects in the annulus fibrosus of intervertebral disks are associated with degeneration and persistent back pain. A clinical need exists for a disk repair strategy that can seal annular defects, be easily delivered during surgical procedures, and restore biomechanics with low risk of her

  13. Damping of a fluid-conveying pipe surrounded by a viscous annulus fluid

    Science.gov (United States)

    Kjolsing, Eric J.; Todd, Michael D.

    2017-04-01

    To further the development of a downhole vibration based energy harvester, this study explores how fluid velocity affects damping in a fluid-conveying pipe stemming from a viscous annulus fluid. A linearized equation of motion is formed which employs a hydrodynamic forcing function to model the annulus fluid. The system is solved in the frequency domain through the use of the spectral element method. The three independent variables investigated are the conveyed fluid velocity, the rotational stiffness of the boundary (using elastic springs), and the annulus fluid viscosity. It was found that, due to the hydrodynamic functions frequency-dependence, increasing the conveyed fluid velocity increases the systems damping ratio. It was also noted that stiffer systems saw the damping ratio increase at a slower rate when compared to flexible systems as the conveyed fluid velocity was increased. The results indicate that overestimating the stiffness of a system can lead to underestimated damping ratios and that this error is made worse if the produced fluid velocity or annulus fluid viscosity is underestimated. A numeric example was provided to graphically illustrate these errors. Approved for publication, LA-UR-15-28006.

  14. On the Use of Biaxial Properties in Modeling Annulus as a Holzapfel-Gasser-Ogden Material

    Directory of Open Access Journals (Sweden)

    Narjes eMomeni Shahraki

    2015-06-01

    Full Text Available Besides the biology, stresses and strains within the tissue greatly influence the location of damage initiation and mode of failure in an intervertebral disc. Finite element models of a functional spinal unit (FSU that incorporate reasonably accurate geometry and appropriate material properties are suitable to investigate such issues. Different material models and techniques have been used to model the anisotropic annulus fibrosus, but the abilities of these models to predict damage initiation in the annulus and to explain clinically observed phenomena are unclear. In this study a hyperelastic anisotropic material model for the annulus with two different sets of material constants, experimentally determined using uniaxial and biaxial loading conditions, were incorporated in a 3D finite element model of a ligamentous FSU. The purpose of the study was to highlight the biomechanical differences (e.g., intradiscal pressure, motion, forces, stresses and strains, etc. due to the dissimilarity between the two sets of material properties (uniaxial and biaxial. Based on the analyses, the biaxial constants simulations resulted in better agreements with the in-vitro and in-vivo data, and thus are more suitable for future damage analysis and failure prediction of the annulus under complex multiaxial loading conditions.

  15. Measurement of the aortic annulus size by real-time three-dimensional transesophageal echocardiography.

    Science.gov (United States)

    Jánosi, Rolf Alexander; Kahlert, Philipp; Plicht, Björn; Wendt, Daniel; Eggebrecht, Holger; Erbel, Raimund; Buck, Thomas

    2011-04-01

    We sought to determine the level of agreement and the reproducibility of two-dimensional (2D) transthoracic (2D-TTE), 2D transesophageal (2D-TEE) and real-time three-dimensional (3D) transesophageal echocardiography (RT3D-TEE) for measurement of aortic annulus size in patients referred for transcatheter aortic valve implantation (TAVI). Accurate preoperative assessment of the dimensions of the aortic annulus is critical for patient selection and successful implantation in those undergoing TAVI for severe aortic stenosis (AS). Annulus size was measured using 2D-TTE, 2D-TEE and RT3D-TEE in 105 patients with severe AS referred for TAVI. Agreement between echocardiographic methods and interobserver variability was assessed using the Bland-Altman method and regression analysis, respectively. The mean aortic annuli were 21,7 ± 3 mm measured with 2D-TTE, 22,6 ± 2,8 mm with 2D-TEE and 22,3 ± 2,9 mm with RT3D-TEE. The results showed a small but significant mean difference and a strong correlation between the three measurement techniques (2D-TTE vs. 2D-TEE mean difference 0,84 ± 1,85 mm, r = 0,8, p annulus measured by 2D-TTE, 2D-TEE and RT3D-TEE. Thus, in patients referred for TAVI, the echocardiographic method used may have an impact on TAVI strategy.

  16. Genipin-crosslinked fibrin hydrogels as a potential adhesive to augment intervertebral disc annulus repair.

    Science.gov (United States)

    Schek, R M; Michalek, A J; Iatridis, J C

    2011-04-18

    Treatment of damaged intervertebral discs is a significant clinical problem and, despite advances in the repair and replacement of the nucleus pulposus, there are few effective strategies to restore defects in the annulus fibrosus. An annular repair material should meet three specifications: have a modulus similar to the native annulus tissue, support the growth of disc cells, and maintain adhesion to tissue under physiological strain levels. We hypothesized that a genipin crosslinked fibrin gel could meet these requirements. Our mechanical results showed that genipin crosslinked fibrin gels could be created with a modulus in the range of native annular tissue. We also demonstrated that this material is compatible with the in vitro growth of human disc cells, when genipin:fibrin ratios were 0.25:1 or less, although cell proliferation was slower and cell morphology more rounded than for fibrin alone. Finally, lap tests were performed to evaluate adhesion between fibrin gels and pieces of annular tissue. Specimens created without genipin had poor handling properties and readily delaminated, while genipin crosslinked fibrin gels remained adhered to the tissue pieces at strains exceeding physiological levels and failed at 15-30%. This study demonstrated that genipin crosslinked fibrin gels show promise as a gap-filling adhesive biomaterial with tunable material properties, yet the slow cell proliferation suggests this biomaterial may be best suited as a sealant for small annulus fibrosus defects or as an adhesive to augment large annulus repairs. Future studies will evaluate degradation rate, fatigue behaviors, and long-term biocompatibility.

  17. The Rhetoric of Culture as an Act of Closure in a Cross-National Software Development Department

    DEFF Research Database (Denmark)

    Jensen, Rasmus Eskild; Nardi, Bonnie

    2014-01-01

    of the word “culture” as an exclusionary act of closure. As theorized by Metiu, who builds on Weber, closure occurs when one group seeks to preserve the advantages of their situation relative to another group. We conducted an ethnographic study of a cross-national software department with members in Denmark...... used a “rhetoric of culture” as an act of closure, and we focus on technology choices and behavior as they were impacted by closure....

  18. The Lawn Hill annulus: An Ordovician meteorite impact into water-saturated dolomite

    Science.gov (United States)

    Darlington, Vicki; Blenkinsop, Tom; Dirks, Paul; Salisbury, Jess; Tomkins, Andrew

    2016-12-01

    The Lawn Hill Impact Structure (LHIS) is located 250 km N of Mt Isa in NW Queensland, Australia, and is marked by a highly deformed dolomite annulus with an outer diameter of 18 km, overlying low metamorphic grade siltstone, sandstone, and shale, along the NE margin of the Georgina Basin. This study provides detailed field observations from sections of the Lawn Hill annulus and adjacent areas that demonstrate a clear link between the deformation of the dolomite and the Lawn Hill impact. 40Ar-39Ar dating of impact-related melt particles provides a time of impact in the Ordovician (472 ± 8 Ma) when the Georgina Basin was an active depocenter. The timing and stratigraphic thickness of the dolomite sequence in the annulus suggest that there was possibly up to 300 m of additional sedimentary rocks on top of the currently exposed Thorntonia Limestone at the time of impact. The exposed annulus is remarkably well preserved, with preservation attributed to postimpact sedimentation. The LHIS has an atypical crater morphology with no central uplift. The heterogeneous target materials at Lawn Hill were probably low-strength, porous, and water-saturated, with all three properties affecting the crater morphology. The water-saturated nature of the carbonate unit at the time of impact is thought to have influenced the highly brecciated nature of the annulus, and restricted melt production. The impact timing raises the possibility that the Lawn Hill structure may be a member of a group of impacts resulting from an asteroid breakup that occurred in the mid-Ordovician (470 ± 6 Ma).

  19. Planning for integrated mine closure

    Energy Technology Data Exchange (ETDEWEB)

    Linda Starke (ed.)

    2008-07-01

    This document presents an Integrated Mine Closure Planning Toolkit for the mining and metals sector. The toolkit is intended to be used to promote a more disciplined approach to integrated closure planning and to increase the uniformity of good practices across the sector. The concepts apply equally well to both large and small companies. The document is not intended to be prescriptive; it provides a suite of tools that can be brought to bear in formulating well-considered decisions when planning for closure. It uses a risk and opportunity based process to guide the practitioner through the iterative process of preparing for planned closure. The first section, with head office and mine management personnel as the primary audience, describes the participants of effective closure planning. Sections 2 and 3 provide the frameworks for a conceptual closure plan and a detailed plan. The key audiences for these two sections are mine management and head office personnel, financial modellers and estimators, governments, academics and non-governmental organizations. The forth section addresses decommissioning and post closure planning, and Section 5 draws together the conclusions and outlines several unresolved issues. The five narrative sections are followed by Section 6 which outlines 13 tools, some of which are already available in earlier ICMM publications, member practices and other sector-affiliated publications. Others have been developed to cover identified gaps. These tools provide the practitioner with practical work processes, examples and contexts within which to apply closure planning discipline.

  20. Plastic compression technology and mold design of HDPE closures for beverage bottles%低磨损HDPE饮料瓶盖压塑成型模具设计

    Institute of Scientific and Technical Information of China (English)

    罗达; 梁文杰

    2013-01-01

    针对传统饮料瓶盖压塑成型模具中存在的内衬套与螺纹型芯采用滑动摩擦结构,摩擦表面容易拉毛、卡死,模具容易磨损等问题,将磨损小、运动阻力小的滚动摩擦技术应用到压塑成型模具中,开展了能否在内衬套与螺纹型芯之间加入一个滚动部件代替原来滑动摩擦的分析,建立了滑动摩擦、滚动摩擦与磨损速度之间的关系,提出了在内衬套与螺纹型芯之间加入一个钢球保持圈,将原来的滑动摩擦改为滚动摩擦的方法,以达到减少磨损、提高模具寿命的目的.在提高模具寿命、瓶盖质量上,对模具的结构、制造技术、经济效益等方面进行了评价.开展了新结构压塑成型模具的设计、制造工作,并在原制盖机上进行了长期试验.研究结果表明,该模具磨损非常小,瓶盖质量比以前更好;且与传统的压塑成型模具相比寿命可提高1倍以上.%Aiming that the sliding friction structure in the inner lining sleeve and the screw thread core of the traditional beverage bottle cap pressing forming mould caused the friction surfaces to nap,blocking,easy wear etc., the rolling friction technology with wear small, small movement resistance was applied to the compression molding mould. Whether a rolling member was inserted between the inner bushing and the screw thread core in place of the original sliding friction was discussed.The relationship between the sliding friction, rolling friction and the wear speed was established, a ball retainer ring was added between the inner bushing and the screw thread core. The original sliding friction was changed into the rolling friction, thereby reducing wear and improving the life of the mould. The mould structure, manufacturing technology, economic benefits etc. were evaluated on the mould life and the cap quality. New structure of compression molding mold was designed and manufactured, and the long term test was developed on the original

  1. Role of calcium signaling in down-regulation of aggrecan induced by cyclic tensile strain in annulus fibrosus cells

    Institute of Scientific and Technical Information of China (English)

    GUO Zhi-liang; ZHOU Yue; LI Hua-zhuang; CAO Guo-yong; TENG Hai-jun

    2006-01-01

    Objective:To study the role of intracellular calcium signal pathway in the down-regulation of aggrecan induced by cyclic tensile strain in the annulus fibrosus cells. Methods :The expression of aggrecan mRNA and core protein were respectively detected with RT-PCR and western blot after the channels transmitting calcium ions were blocked with EGTA, gadolinium and verapamil. Results:EGTA, gadolinium and verapamil partially prevented the effects of cyclic tensile strain on the expression of aggrecan in annulus fibrosus cells. Conclusion:The calcium signaling is involved in the down-regulation of proteoglycan resulting from cyclic tensile strain in the annulus fibrosus cells.

  2. Single-shell tank closure work plan. Revision A

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    In January 1994, the Hanford Federal Facility Agreement and Conset Order (Tri-Party Agreement) was amended to reflect a revised strategy for remediation of radioactive waste in underground storage tanks. These amendments include milestones for closure of the single-shell tank (SST) operable units, to be initiated by March 2012 and completed by September 2024. This SST-CWP has been prepared to address the principal topical areas identified in Tri-Party Agreement Milestone M-45-06 (i.e., regulatory pathway, operable unit characterization, waste retrieval, technology development, and a strategy for achieving closure). Chapter 2.0 of this SST-CWP provides a brief description of the environmental setting, SST System, the origin and characteristics of SST waste, and ancillary equipment that will be remediated as part of SST operable unit closure. Appendix 2A provides a description of the hydrogeology of the Hanford Site, including information on the unsaturated sediments (vadose zone) beneath the 200 Areas Plateau. Chapter 3.0 provides a discussion of the laws and regulations applicable to closure of the SST farm operable units. Chapter 4.0 provides a summary description of the ongoing characterization activities that best align with the proposed regulatory pathway for closure. Chapter 5.0 describes aspects of the SST waste retrieval program, including retrieval strategy, technology, and sequence, potential tank leakage during retrieval, and considerations of deployment of subsurface barriers. Chapter 6.0 outlines a proposed strategy for closure. Chapter 7.0 provides a summary of the programs underway or planned to develop technologies to support closure. Ca. 325 refs.

  3. Most recent developments for monitoring and controlling the annulus conditions of Marlim-Sul flexible risers

    Energy Technology Data Exchange (ETDEWEB)

    Rabelo, Alexandre S.; Motta, Antonio; Romero, Antonio; Nunes, Joao P.; Zaganelli Junior, Jose L.; Brack, Marcelo [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The main objective of this paper is to present the recent developments for monitoring and controlling the annulus conditions of flexible risers. PETROBRAS has been monitoring the pressure of permeated gas in the annulus region of some risers in order to infer the eventual occurrence of non-conformities as damage on the riser external sheath, for example. Such occurrence would affect the permeated gas flow pattern, the gas pressurization period and the relief valve opening frequencies. Furthermore, the mentioned occurrence would increase the susceptibility of the steel armors to experience the potential failure mechanism of corrosion. In PETROBRAS, the current monitoring method is characterized by visual and periodic manometer readings from a manometer set installed near each riser end-fitting. The data is recorded in a daily report and analyzed by personnel onshore, who are in charge of comparing data and requesting relief valve's actuation, whenever necessary. The paper illustrates Marlim-Sul Asset experience on monitoring and data processing to control the annulus conditions of flexible risers during operation. It presents the in-house developed methodology to data management and processing. This methodology is based on a daily analysis of the permeated gas data worksheet. Some examples are given to illustrate it. The paper also summarizes current developments, in progress, in order to improve riser integrity management. The first development is being done to implement, in the future, automatic data acquisition and control systems. The purpose of automating this process is to improve methods and techniques for data acquisition, transmission and processing. The second development focuses on applications in which riser top end-fittings are submerged. In this particular scenario, a special system - with a quick connection sub sea device - is under development to allow the connection, by divers, after the riser pull-in, of the riser annulus to the platform gas

  4. Closure report for N Reactor

    Energy Technology Data Exchange (ETDEWEB)

    1994-01-01

    This report has been prepared to satisfy Section 3156(b) of Public Law 101-189 (Reports in Connection with Permanent Closures of Department of Energy Defense Nuclear Facilities), which requires submittal of a Closure Report to Congress by the Secretary of Energy upon the permanent cessation of production operations at a US Department of Energy (DOE) defense nuclear facility (Watkins 1991). This closure report provides: (1) A complete survey of the environmental problems at the facility; (2) Budget quality data indicating the cost of environmental restoration and other remediation and cleanup efforts at the facility; (3) A proposed cleanup schedule.

  5. Stresses and Strains in a Cold-Worked Annulus

    Science.gov (United States)

    1988-09-01

    Airways Limited Ansett Airlines of Australia, Library BHP, Melbourne Research Laboratories Hawker de Havilland Aust Pty Ltd, Victoria, Library Hawker de...Library Statutory and State Authorities and Industry Aero-Space Technologies Australia, Manager/Librarian (2 copies) Australian Airlines, Library Qantas ...DOWNGRADING DARL APPROVAL 12. SECDARY DISTRIBUTION (OF THIS DoCUmr) Approved for public release. OVERSEAS ?2KQUIRIES OUTSIDE STATED LIMITATIONS SHOULD BE

  6. Laboratory experiments in a baroclinic annulus with heating and cooling on the horizontal boundaries

    Science.gov (United States)

    Miller, T. L.; Fowlis, W. W.

    1986-01-01

    Experiments have been performed in a cylindrical annulus with horizontal temperature gradients imposed upon the horizontal boundaries and in which the vertical depth was smaller than the width of the annulus. Qualitative observations were made by the use of small, suspended, reflective flakes in the liquid (water). Four basic regimes of flow were observed: (1) axisymmetric flow, (2) deep cellular convection, (3) boundary layer convective rolls, and (4) baroclinic waves. In some cases there was a mix of baroclinic and convective instabilities present. As a 'mean' interior Richardson number was decreased from a value greater than unity to one less than zero, axisymmetric baroclinic instability of the Solberg type was never observed. Rather, the transition was from non-axisymmetric baroclinic waves, to a mix of baroclinic and convective instability, to irregular cellular convection.

  7. From puncture to closure of the common femoral artery in endovascular aortic repair

    DEFF Research Database (Denmark)

    Lönn, Lars; Larzon, Thomas; Van Den Berg, Jos C

    2010-01-01

    or epidural anesthesia. The evolving stent-technology with smaller sheath sizes has broadened the scenario for alternative approaches for access and closure of the common femoral arteries. The following review presents an introduction on technical aspects of puncture of the femoral artery and closure...

  8. The cyclicity of the period annulus of a quadratic reversible system with one center of genus one

    OpenAIRE

    PENG, Linping; Sun, Yannan

    2014-01-01

    This paper is concerned with a quadratic reversible and non-Hamiltonian system with one center of genus one. By using the properties of related elliptic integrals and the geometry of some planar curves defined by them, we prove that the cyclicity of the period annulus of the considered system under small quadratic perturbations is two. This verifies Gautier's conjecture about the cyclicity of the related period annulus.

  9. The cyclicity of the period annulus of a quadratic reversible system with one center of genus one

    OpenAIRE

    PENG, Linping; Sun, Yannan

    2011-01-01

    This paper is concerned with a quadratic reversible and non-Hamiltonian system with one center of genus one. By using the properties of related elliptic integrals and the geometry of some planar curves defined by them, we prove that the cyclicity of the period annulus of the considered system under small quadratic perturbations is two. This verifies Gautier's conjecture about the cyclicity of the related period annulus.

  10. Hysteresis and the transition between axisymmetric flow and wave flow in the baroclinic annulus

    Science.gov (United States)

    Miller, Timothy L.; Butler, Karen A.

    1991-01-01

    A numerical model is employed to establish the transitions between axisymmetric flow and wave flow in the rotating, differentially heated annulus experiments of Fein for both rigid lid and free surface cases. It is shown that, for most of the transitions, the method of computing a steady axisymmetric flow and then testing its linear stability to wave disturbance results in good agreement with the experiments. Implications for the investigation of the dynamics of the earth's atmosphere are considered.

  11. Centrifugally driven convection in the rotating cylindrical annulus with modulated boundaries

    Directory of Open Access Journals (Sweden)

    M. Westerburg

    2003-01-01

    Full Text Available The effect of sinusoidally modulated conical end boundaries on convection in a rotating cylindrical annulus is investigated theoretically and experimentally. A quasiperiodic time dependence of convection in the form of thermal Rossby waves is found and semi-quantitative agreement between theory and measurements can be established. The results are relevant to convection in the Earth's outer core close to the tangent cylinder touching the inner core at its equator.

  12. The Influence of Horizontal Boundaries on Ekman Circulation and Angular Momentum Transport in a Cylindrical Annulus

    OpenAIRE

    Obabko, Aleksandr V.; Cattaneo, Fausto; Fischer, Paul F.

    2008-01-01

    We present numerical simulations of circular Couette flow in axisymmetric and fully three-dimensional geometry of a cylindrical annulus inspired by Princeton MRI liquid gallium experiment. The incompressible Navier-Stokes equations are solved with the spectral element code Nek5000 incorporating realistic horizontal boundary conditions of differentially rotating rings. We investigate the effect of changing rotation rates (Reynolds number) and of the horizontal boundary conditions on flow struc...

  13. A Fast Stble Marching Scheme for Calculating Mixed Convection in a Vertical Rotating Annulus

    Institute of Scientific and Technical Information of China (English)

    Chao-MinZhang; Zeng-YuanGuo

    1993-01-01

    An iterative simultanous solution method is developed to efficiently solve the Newton-Raphson linear equation set for velocity in three dimensions,pressure and temperature,The proposed method is demonstrated for several cases of the thermal drive in a vertical rotating annulus,and is shown to be insensitive to dimensionless time step,requiring significantly less computational effort to converge to the desired accuracy than SIMPLEC,even for low Prandtl number fluid flows.

  14. Genipin-crosslinked fibrin hydrogels as a potential adhesive to augment intervertebral disc annulus repair

    Directory of Open Access Journals (Sweden)

    RM Schek

    2011-04-01

    Full Text Available Treatment of damaged intervertebral discs is a significant clinical problem and, despite advances in the repair and replacement of the nucleus pulposus, there are few effective strategies to restore defects in the annulus fibrosus. An annular repair material should meet three specifications: have a modulus similar to the native annulus tissue, support the growth of disc cells, and maintain adhesion to tissue under physiological strain levels. We hypothesized that a genipin crosslinked fibrin gel could meet these requirements. Our mechanical results showed that genipin crosslinked fibrin gels could be created with a modulus in the range of native annular tissue. We also demonstrated that this material is compatible with the in vitro growth of human disc cells, when genipin:fibrin ratios were 0.25:1 or less, although cell proliferation was slower and cell morphology more rounded than for fibrin alone. Finally, lap tests were performed to evaluate adhesion between fibrin gels and pieces of annular tissue. Specimens created without genipin had poor handling properties and readily delaminated, while genipin crosslinked fibrin gels remained adhered to the tissue pieces at strains exceeding physiological levels and failed at 15-30%. This study demonstrated that genipin crosslinked fibrin gels show promise as a gap-filling adhesive biomaterial with tunable material properties, yet the slow cell proliferation suggests this biomaterial may be best suited as a sealant for small annulus fibrosus defects or as an adhesive to augment large annulus repairs. Future studies will evaluate degradation rate, fatigue behaviors, and long-term biocompatibility.

  15. [Evaluation of aortic valve replacement involving small severely calcified aortic annulus in elderly patients].

    Science.gov (United States)

    Iwahashi, M; Nishimura, Y; Hiramatsu, K; Komori, S; Shibata, M; Yuzaki, M; Okamura, Y

    2006-04-01

    We performed aortic valve replacement in 24 patients aged over 70 with small calcified valves. The surgical management of such patients remains controversial as the extensive calcification compromises implantation. Hence, we used an ultrasonic debridement instrument to remove calcium and selected a small prosthesis with the largest possible orifice without enlargement of the aortic annulus. Echocardiography showed significant reductions in left ventricular mass index compared with preoperative values. Early and mid-term prognosis has been relatively good.

  16. Closure and Sealing Design Calculation

    Energy Technology Data Exchange (ETDEWEB)

    T. Lahnalampi; J. Case

    2005-08-26

    The purpose of the ''Closure and Sealing Design Calculation'' is to illustrate closure and sealing methods for sealing shafts, ramps, and identify boreholes that require sealing in order to limit the potential of water infiltration. In addition, this calculation will provide a description of the magma that can reduce the consequences of an igneous event intersecting the repository. This calculation will also include a listing of the project requirements related to closure and sealing. The scope of this calculation is to: summarize applicable project requirements and codes relating to backfilling nonemplacement openings, removal of uncommitted materials from the subsurface, installation of drip shields, and erecting monuments; compile an inventory of boreholes that are found in the area of the subsurface repository; describe the magma bulkhead feature and location; and include figures for the proposed shaft and ramp seals. The objective of this calculation is to: categorize the boreholes for sealing by depth and proximity to the subsurface repository; develop drawing figures which show the location and geometry for the magma bulkhead; include the shaft seal figures and a proposed construction sequence; and include the ramp seal figure and a proposed construction sequence. The intent of this closure and sealing calculation is to support the License Application by providing a description of the closure and sealing methods for the Safety Analysis Report. The closure and sealing calculation will also provide input for Post Closure Activities by describing the location of the magma bulkhead. This calculation is limited to describing the final configuration of the sealing and backfill systems for the underground area. The methods and procedures used to place the backfill and remove uncommitted materials (such as concrete) from the repository and detailed design of the magma bulkhead will be the subject of separate analyses or calculations. Post-closure

  17. Hydraulic resistance of plane channels and annulus with different roughness on opposite walls

    Science.gov (United States)

    Korsun, A. S.; Kutsenko, K. V.; Pisarevsky, M. I.; Fedoseev, V. N.; Balberkina, Y. N.

    2017-03-01

    A new method for prediction of hydraulic resistance for a turbulent flow in plane channels and annulus is proposed. In spite of the importance of this issue, only very few publications devoted to the investigation into hydrodynamics in these channels are available, and there are no methods for predicting hydraulic resistance of a flow in these channels at all. The flow in channels with different roughness on the walls is described using the Prandtl semiempirical theory of a turbulent boundary layer. The flow in a channel cross-section is divided into two noninteracting layers of different thickness flowing along the walls with different roughness. The basic balance correlations are derived for a plane channel. To match the velocity profiles of both layers at the interface point, a logarithmic velocity profile is used. This yields a closed system of equations for predicting hydraulic resistance in plane channels with a given different roughness on opposite walls. It is demonstrated that the obtained correlation may be used for predicting hydraulic resistance in annulus as well. Experiments were carried out with a water flow in an annulus. Each annuli consisted of a pipe having a smooth wall into which a rod with artificial roughness on the surface was inserted coaxially. Two types of roughness were investigated: trapezoid and threadlike ones. Comparison of the predictions with the experimental data confirmed the validity of the proposed method. It can be used in designing flowpaths of various power installations.

  18. Annulus formation on scales of four species of coregonids reared under artificial conditions

    Science.gov (United States)

    Hogman, Walter J.

    1968-01-01

    Scales from known-age coregonids reared in the laboratory were examined to determine when annuli formed and to learn possible factors of their formation. Scales were taken monthly from marked fish for periods up to 21 months. Scales were also examined from fish that died and from preserved specimens of young-of-the-year for each species. Two marks formed on almost all scales each calender year. The stronger formed during March-April and the weaker in October-November. Both marks had all the usual characteristics of an annulus but the spring mark was considered the annulus and the fall mark an accessory check. The annulus formed during a period of constant temperatures and of little change in growth or increasing growth. The accessory check formed during a period of declining temperatures (1-5 degrees F, or 0.6-2.8 degrees C, per month) and of little change in growth or declining growth. Most fish grew throughout the winter; the only exceptions were one bloater (Coregonus hoyi) and several of the largest lake whitefish (C. clupeaformis). Fish were always given all the food they would eat to eliminate availability of food as a factor of mark formation. The temperature of the water during the winter (50 ±. 0.3 F; 10.0 ±. 0.2 C) did not arrest metabolic activity. The growth rate was related more closely to day length than to other variables examined.

  19. Cubic autocatalysis in a reaction-diffusion annulus: semi-analytical solutions

    Science.gov (United States)

    Alharthi, M. R.; Marchant, T. R.; Nelson, M. I.

    2016-06-01

    Semi-analytical solutions for cubic autocatalytic reactions are considered in a circularly symmetric reaction-diffusion annulus. The Galerkin method is used to approximate the spatial structure of the reactant and autocatalyst concentrations. Ordinary differential equations are then obtained as an approximation to the governing partial differential equations and analyzed to obtain semi-analytical results for this novel geometry. Singularity theory is used to determine the regions of parameter space in which the different types of steady-state diagram occur. The region of parameter space, in which Hopf bifurcations can occur, is found using a degenerate Hopf bifurcation analysis. A novel feature of this geometry is the effect, of varying the width of the annulus, on the static and dynamic multiplicity. The results show that for a thicker annulus, Hopf bifurcations and multiple steady-state solutions occur in a larger portion of parameter space. The usefulness and accuracy of the semi-analytical results are confirmed by comparison with numerical solutions of the governing partial differential equations.

  20. Localized strain measurements of the intervertebral disc annulus during biaxial tensile testing.

    Science.gov (United States)

    Karakolis, Thomas; Callaghan, Jack P

    2015-01-01

    Both inter-lamellar and intra-lamellar failures of the annulus have been described as potential modes of disc herniation. Attempts to characterize initial lamellar failure of the annulus have involved tensile testing of small tissue samples. The purpose of this study was to evaluate a method of measuring local surface strains through image analysis of a tensile test conducted on an isolated sample of annular tissue in order to enhance future studies of intervertebral disc failure. An annulus tissue sample was biaxial strained to 10%. High-resolution images captured the tissue surface throughout testing. Three test conditions were evaluated: submerged, non-submerged and marker. Surface strains were calculated for the two non-marker conditions based on motion of virtual tracking points. Tracking algorithm parameters (grid resolution and template size) were varied to determine the effect on estimated strains. Accuracy of point tracking was assessed through a comparison of the non-marker conditions to a condition involving markers placed on tissue surface. Grid resolution had a larger effect on local strain than template size. Average local strain error ranged from 3% to 9.25% and 0.1% to 2.0%, for the non-submerged and submerged conditions, respectively. Local strain estimation has a relatively high potential for error. Submerging the tissue provided superior strain estimates.

  1. Exogenous thymosin beta4 prevents apoptosis in human intervertebral annulus cells in vitro.

    Science.gov (United States)

    Tapp, H; Deepe, R; Ingram, J A; Yarmola, E G; Bubb, M R; Hanley, E N; Gruber, H E

    2009-12-01

    Loss of cells in the human disc due to programmed cell death (apoptosis) is a major factor in the aging and degenerating human intervertebral disc. Our objective here was to determine if thymosin beta(4) (TB4), a small, multifunctional 5 kDa protein with diverse activities, might block apoptosis in human annulus cells cultured in monolayer or three-dimensional (3D) culture. Apoptosis was induced in vitro using hydrogen peroxide or serum starvation. Annulus cells were processed for identification of apoptotic cells using the TUNEL method. The percentage of apoptotic cells was determined by cell counts. Annulus cells also were treated with TB4 for determination of proliferation, and proteoglycan production was assessed using cell titer and 1,2 dimethylmethylamine (DMB) assays and histological staining. A significant reduction in disc cell apoptosis occurred after TB4 treatment. The percentage of cells undergoing apoptosis decreased significantly in TB4 treated cells in both apoptosis induction designs. TB4 exposure did not alter proteoglycan production as assessed by either DMB measurement or histological staining. Our results indicate the need for further studies of the anti-apoptotic effect of TB4 and suggest that TB4 may have therapeutic application in future biological therapies for disc degeneration.

  2. Radiofrequency catheter ablation of idiopathic ventricular tachycardia and symptomatic premature ventricular contraction originating from valve annulus

    Institute of Scientific and Technical Information of China (English)

    WU Xiao-yu; LIANG Zhao-guang; TAN Zhen; GU Hong-yue; ZHANG Shu; LI Wei-min

    2008-01-01

    Background Radiofrequency catheter ablation (RFCA) has been established as an effective and curative therapy for ventricular tachycardia (VT) and severely symptomatic premature ventricular contraction (PVC) from the outflow tract in structurally normal hearts.This study aimed to investigate electrophysiologic characteristics and effects of RFCA for patients with idiopathic VT and symptomatic PVC originating from the valve annulus.Methods Characteristics of body surface electrocardiogram (ECG) and endocardiogram in a successful RFCA target were analyzed in 16 patients with idiopathic VT and symptomatic PVC originating from the valve annulus.Additionally,the ECG characteristics of vr or PVC were compared with those of manifest Wolff-Parkinson-White (WPW) syndrome originating from the same site of origin in 15 patients.Results Thirteen patients were successful,2 recurrent and 1 failed.The recurrent cases underwent successful ablation the second time guided by the Ensite 3000 mapping system.In all patients with the WPW syndrome,the characteristics of QRS morphology were well matched with those of the VT and PVC that originated from corresponding sites of origin.Conclusions RFCA is an effective curative therapy for VT and symptomatic PVC originating from the valve annulus.There are specific characteristics in ECG and the ablation site could be located by means of the WPW syndrome accessory pathway's algorithm.

  3. RCRA closure of mixed waste impoundments

    Energy Technology Data Exchange (ETDEWEB)

    Blaha, F.J. [Doty and Associates (United States); Greengard, T.C.; Arndt, M.B. [Rockwell International (United States)

    1989-11-01

    A case study of a RCRA closure action at the Rocky Flats Plant is presented. Closure of the solar evaporation ponds involves removal and immobilization of a mixed hazardous/radioactive sludge, treatment of impounded water, groundwater monitoring, plume delineation, and collection and treatment of contaminated groundwater. The site closure is described within the context of regulatory negotiations, project schedules, risk assessment, clean versus dirty closure, cleanup levels, and approval of closure plans and reports. Lessons learned at Rocky Flats are summarized.

  4. Interobserver variability of CT angiography for evaluation of aortic annulus dimensions prior to transcatheter aortic valve implantation (TAVI)

    Energy Technology Data Exchange (ETDEWEB)

    Schmidkonz, C., E-mail: christian.schmidkonz@gmail.com [Department of Internal Medicine 2 (Cardiology), University of Erlangen, Ulmenweg 18, D-91054 Erlangen (Germany); Marwan, M.; Klinghammer, L.; Mitschke, M.; Schuhbaeck, A.; Arnold, M. [Department of Internal Medicine 2 (Cardiology), University of Erlangen, Ulmenweg 18, D-91054 Erlangen (Germany); Lell, M. [Radiological Institute, University of Erlangen, Maximiliansplatz 1, D-91054 Erlangen (Germany); Achenbach, S.; Pflederer, T. [Department of Internal Medicine 2 (Cardiology), University of Erlangen, Ulmenweg 18, D-91054 Erlangen (Germany)

    2014-09-15

    Highlights: • Cardiac CT provides highly reproducible measurements of aortic annulus and root dimensions prior to TAVI. • The perimeter-derived aortic annulus diameter shows the lowest interobserver variability. • If all three CT sizing methods are considered and stated as a “consensus result”, mismatches in prosthesis size selection can be further reduced. - Abstract: Objective: Assessment of aortic annulus dimensions prior to transcatheter aortic valve implantation (TAVI) is crucial for accurate prosthesis sizing in order to avoid prosthesis–annulus-mismatch possibly resulting in complications like valve dislodgement, paravalvular regurgitation or annulus rupture. Contrast-enhanced multidetector computed tomography allows 3-dimensional assessment of aortic annulus dimensions. Only limited data exist about its interobserver variability. Methods: In 100 consecutive patients with symptomatic severe aortic stenosis (51 male, BMI 27 ± 5 kg/m{sup 2}, age 81 ± 7 years, heart rate 72 ± 15 bpm, Logistic Euroscore 31 ± 14%, STS-Score 7 ± 4%), pre-interventional aortic annulus assessment was performed by dual source computed tomography (collimation 2 × 128 × 0.6 mm, high pitch spiral data acquisition mode, 40–60 ml contrast agents, radiation dose 3.5 ± 0.9 mSv). The following aortic annulus characteristics were determined by three independent observers: aortic annulus maximum, minimum and mean diameters (D{sub max}, D{sub min}, D{sub mean}), eccentricity index (EI), effective aortic annulus diameter according to its circumference (D{sub circ}), effective aortic annulus diameter according to its area (D{sub area}), distance from the aortic annulus plane to the left (LCA) and right coronary artery (RCA) ostia, maximum (D{sub max}AR) and minimum aortic root diameter (D{sub min}AR), maximum (D{sub max}STJ) and minimum diameter of the sinotubular junction (D{sub min}STJ). Subsequently, interobserver variabilities were assessed. Results: Correlation between

  5. Flow regime transition criteria for two-phase flow in a vertical annulus

    Energy Technology Data Exchange (ETDEWEB)

    Julia, J. Enrique, E-mail: bolivar@emc.uji.es [Departamento de Ingenieria Mecanica y Construccion, Universitat Jaume I., Campus de Riu Sec, 12071 Castellon (Spain); Hibiki, Takashi [School of Nuclear Engineering, Purdue University, 400 Central Dr., West Lafayette, IN 47907-2017 (United States)

    2011-10-15

    Highlights: > Flow regime transition model is presented for two-phase flows in a vertical annulus. > The transition criteria is easy to be implemented in computational codes. > Final equations do not need experimental input. > New developed model shows better predicting capabilities than existing correlations. > New developed model shows good predicting capabilities in boiling flow. - Abstract: In this work, a new flow regime transition model is proposed for two-phase flows in a vertical annulus. Following previous works, the flow regimes considered are bubbly (B), slug (S) or cap-slug (CS), churn (C) and annular (A). The B to CS transition is modeled using the maximum bubble package criteria of small bubbles. The S to C transition takes place for small annulus perimeter flow channels and it is assumed to occur when the mean void fraction over the entire region exceeds that over the slug-bubble section. If the annulus perimeter is larger that the distorted bubble limit the cap-slug flow regime will be considered since in these conditions it is not possible to distinguish between cap and partial-slug bubbles. The CS to C transition is modeled using the maximum bubble package criteria. However, this transition considers the coalescence of cap and spherical bubbles in order to take into account the flow channel geometry. Finally, the C to A transition is modeled assuming two different mechanisms, (a) flow reversal in the liquid film section along large bubbles; (b) destruction on liquid slugs or large waves by entrainment or deformation. In the S to C and C to A flow regime transitions the annulus flow channel is considered as a rectangular flow channel with no side walls. In all the modeled transitions the drift-flux model is used to obtain the final correlations. The final equations for every flow regime transition are easy to be implemented in computational codes and not experimental input is needed. The prediction accuracy of the newly developed model has been

  6. INTEC CPP-603 Basin Water Treatment System Closure: Process Design

    Energy Technology Data Exchange (ETDEWEB)

    Kimmitt, Raymond Rodney; Faultersack, Wendell Gale; Foster, Jonathan Kay; Berry, Stephen Michael

    2002-09-01

    This document describes the engineering activities that have been completed in support of the closure plan for the Idaho Nuclear Technology and Engineering Center (INTEC) CPP-603 Basin Water Treatment System. This effort includes detailed assessments of methods and equipment for performing work in four areas: 1. A cold (nonradioactive) mockup system for testing equipment and procedures for vessel cleanout and vessel demolition. 2. Cleanout of process vessels to meet standards identified in the closure plan. 3. Dismantlement and removal of vessels, should it not be possible to clean them to required standards in the closure plan. 4. Cleanout or removal of pipelines and pumps associated with the CPP-603 basin water treatment system. Cleanout standards for the pipes will be the same as those used for the process vessels.

  7. Closure Plan for the Area 5 Radioactive Waste Management Site at the Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Management

    2008-09-01

    The Area 5 Radioactive Waste Management Site (RMWS) at the Nevada Test Site (NTS) is managed and operated by National Security Technologies, LLC (NSTec), for the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO). This document is the first update of the preliminary closure plan for the Area 5 RWMS at the NTS that was presented in the Integrated Closure and Monitoring Plan (DOE, 2005a). The major updates to the plan include a new closure schedule, updated closure inventory, updated site and facility characterization data, the Title II engineering cover design, and the closure process for the 92-Acre Area of the RWMS. The format and content of this site-specific plan follows the Format and Content Guide for U.S. Department of Energy Low-Level Waste Disposal Facility Closure Plans (DOE, 1999a). This interim closure plan meets closure and post-closure monitoring requirements of the order DOE O 435.1, manual DOE M 435.1-1, Title 40 Code of Federal Regulations (CFR) Part 191, 40 CFR 265, Nevada Administrative Code (NAC) 444.743, and Resource Conservation and Recovery Act (RCRA) requirements as incorporated into NAC 444.8632. The Area 5 RWMS accepts primarily packaged low-level waste (LLW), low-level mixed waste (LLMW), and asbestiform low-level waste (ALLW) for disposal in excavated disposal cells.

  8. Multi-detector computed tomography is equivalent to trans-oesophageal echocardiography for the assessment of the aortic annulus before transcatheter aortic valve implantation

    Energy Technology Data Exchange (ETDEWEB)

    Rixe, Johannes; Schmitt, Joern; Neumann, Thomas; Hamm, Christian W.; Rolf, Andreas [Kerckhoff Heart and Thorax Center, Department of Cardiology, Bad Nauheim (Germany); University Hospital of Giessen and Marburg, Site Giessen, Department of Internal Medicine I (Cardiology, Angiology), Giessen (Germany); Schuhbaeck, Annika; Nef, Holger M.; Achenbach, Stephan [University Hospital of Giessen and Marburg, Site Giessen, Department of Internal Medicine I (Cardiology, Angiology), Giessen (Germany); Liebetrau, Christoph; Moellmann, Helge; Szardien, Sebastian; Brandt, Roland [Kerckhoff Heart and Thorax Center, Department of Cardiology, Bad Nauheim (Germany); Schneider, Christian; Krombach, Gabriele [University Hospital of Giessen and Marburg, Department of Radiology, Giessen (Germany)

    2012-12-15

    In transcatheter aortic valve implantation (TAVI), assessment of the aortic annulus is mandatory. We sought to investigate the correlation between trans-oesophageal echocardiography (TEE) and multi-detector computed tomography (MDCT) for annulus diameter assessment before TAVI. A total of 122 patients (67 male, mean age 84 {+-} 6 years) underwent MDCT and TEE for TAVI planning. In TEE annulus diameters were obtained in a long-axis view at diastole. MDCT data were evaluated using MPR images, and corresponding projections were adjusted for MDCT and TEE. Patients were classified by the predominant localisation of aortic valve calcifications, and annulus diameters between TEE and MDCT were correlated. Additionally, the eccentricity of the aortic annulus was calculated. Mean eccentricity of the aortic annulus determined by MDCT was 0.34 {+-} 0.17, with no difference according to valve calcification. Regarding the aortic annulus diameter, the mean values measured were 24.3 {+-} 2.1 mm in MDCT and 24.0 {+-} 2.5 mm in TEE (P < 0.0001 for agreement). Independent of the pattern of aortic valve calcification, close correlation is found between CT and TEE measurements of the aortic annulus diameter. In addition, CT demonstrates the non-circular shape of the aortic annulus. (orig.)

  9. [Laparotomy closure in advanced peritonitis].

    Science.gov (United States)

    Bensman, V M; Savchenko, Yu P; Shcherba, S N; Golikov, I V; Triandafilov, K V; Chaykin, V V; Pyatakov, S N; Saakyan, A S; Saakyan, E A

    to improve the results of advanced peritonitis management. 743 patients with advanced peritonitis were studied. Patients were divided into 2 groups depending on treatment strategy. Programmed relaparotomy combined with removable draining musculoaponeurotic seams during laparotomy closure decreased mortality from 47.8±2.7% to 24.1±2.3% (pperitonitis management. Laparotomy closure with only cutaneous seams is indicated in case of persistent abdominal hypertension. Large eventration always requires abdominal wall repair. APACHE-III scale scores have significant prognostic value in patients with advanced peritonitis.

  10. Homogeneous orbit closures and applications

    CERN Document Server

    Lindenstrauss, Elon

    2011-01-01

    We give new classes of examples of orbits of the diagonal group in the space of unit volume lattices in R^d for d > 2 with nice (homogeneous) orbit closures, as well as examples of orbits with explicitly computable but irregular orbit closures. We give Diophantine applications to the former, for instance we show that if x is the cubic root of 2 then for any y,z in R liminf |n|=0 (as |n| goes to infinity), where denotes the distance of a real number c to the integers.

  11. Comparison of aortic annulus diameter measurement between multi-detector computed tomography and echocardiography: a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Ruifang Zhang

    Full Text Available BACKGROUND AND PURPOSE: Accurate measurement of aortic annulus diameter is crucial for choosing suitable prosthetic size for transcatheter aortic valve implantation (TAVI. Several imaging methods are available for the measurement, but significant variability between different modalities has been observed. The purpose of this study was to systematically compare the measurements of aortic annulus diameter between multi-detector computed tomography (MDCT, transthoracic echocardiography (TTE, and transesophegeal echocardiography (TEE. METHODS: PubMed and EMBASE databases between January 2000 and January 2012 were searched. We extracted data from eligible studies evaluating the aortic annulus diameter by MDCT and echocardiography (TTE, TEE, or both. We performed a random-effects meta-analysis to calculate the weighted mean differences of aortic annulus diameter measurement between MDCT, TTE, and TEE. RESULTS: A total of 10 eligible studies involving 581 subjects with aortic valve stenosis were included. Aortic annulus diameter measured on coronal view by MDCT (25.3±0.52 mm was respectively larger than that measured on sagittal view by MDCT (22.7±0.37 mm, TTE (22.6±0.28 mm, and TEE (23.1±0.32 mm. The weighted mean difference of aortic annulus diameter between coronal view by MDCT and TTE these two methods was 2.97 mm, followed by the weighted mean difference of 2.53 mm between coronal view and sagittal view by MDCT, and the mean difference of 1.74 mm between coronal view on MDCT and TEE (P<0.0001 for all. The weighted mean difference of aortic annulus diameter measurement between TEE and TTE was significant but somewhat small (0.45 mm, P = 0.007. CONCLUSION: Aortic annulus diameter measured on coronal view by MDCT was robustly and significantly larger than that obtained on sagittal view by MDCT, TTE, or TEE. Such variability of aortic annulus diameter measurement by different imaging modalities cannot be ignored when developing optimal

  12. Conjugated Conduction-Free Convection Heat Transfer in an Annulus Heated at Either Constant Wall Temperature or Constant Heat Flux

    Directory of Open Access Journals (Sweden)

    HAROON IMTIAZ

    2017-04-01

    Full Text Available In this paper, we investigate numerically the effect of thermal boundary conditions on conjugated conduction-free convection heat transfer in an annulus between two concentric cylinders using Fourier Spectral method. The inner wall of the annulus is heated and maintained at either CWT (Constant Wall Temperature or CHF (Constant Heat Flux, while the outer wall is maintained at constant temperature. CHF case is relatively more significant for high pressure industrial applications, but it has not received much attention. This study particularly focuses the latter case (CHF. The main influencing parameters on flow and thermal fields within the annulus are: Rayleigh number Ra; thickness of inner wall Rs; radius ratio Rr and inner wall-fluid thermal conductivity ratio Kr. The study has shown that the increase in Kr increases the heat transfer rate through the annulus for heating at CWT and decreases the inner wall dimensionless temperature for heating at CHF and vice versa. It has also been proved that as the Rs increases at fixed Ra and Rr, the heat transfer rate decreases for heating at CWT and the inner wall dimensionless temperature increases for heating at CHF at Kr 1 depends on Rr. It has been shown that for certain combinations of controlling parameters there will be a value of Rr at which heat transfer rate will be minimum in the annulus in case of heating at CWT, while

  13. The Influence of Horizontal Boundaries on Ekman Circulation and Angular Momentum Transport in a Cylindrical Annulus

    CERN Document Server

    Obabko, Aleksandr V; Fischer, Paul F

    2008-01-01

    We present numerical simulations of circular Couette flow in axisymmetric and fully three-dimensional geometry of a cylindrical annulus inspired by Princeton MRI liquid gallium experiment. The incompressible Navier-Stokes equations are solved with the spectral element code Nek5000 incorporating realistic horizontal boundary conditions of differentially rotating rings. We investigate the effect of changing rotation rates (Reynolds number) and of the horizontal boundary conditions on flow structure, Ekman circulation and associated transport of angular momentum through the onset of unsteadiness and three-dimensionality. A mechanism for the explanation of the dependence of the Ekman flows and circulation on horizontal boundary conditions is proposed.

  14. Cardiac valve annulus manual segmentation using computer assisted visual feedback in three-dimensional image data.

    Science.gov (United States)

    Casero, Ramon; Burton, Rebecca A B; Quinn, T; Bollensdorff, Christian; Hales, Patrick; Schneider, Jurgen E; Kohl, Peter; Grau, Vicente

    2010-01-01

    Annulus manual segmentation is an important tool for the study of valve anatomy and physiology, for the four main valves of the heart (mitral, tricuspid, aortic and pulmonary). In this paper we review two traditional manual segmentation approaches: slice-by-slice and interpolating a sparse set of landmarks with a spline curve. We propose a new Spline Tool for the open source software platform Seg3D, that is fast and improves spatial coherence by providing visual feedback of the segmentation in real time. The Spline Tool was tested successfully on 14 rat hearts, on all four valves.

  15. Modelling of flow boiling heat transfer in a cylindrical annulus mini gap

    Directory of Open Access Journals (Sweden)

    Piasecka Magdalena

    2017-01-01

    Full Text Available This paper presents the results of investigations into flow boiling heat transfer in a mini gap 1 mm wide. The mathematical approaches of the heat transfer coefficient determination were also proposed. It was considered two ways of describing layers in a measurement module with a cylindrical annulus mini gap. In the first approach, the measurement module was treated as a planar multilayer wall and in the second approach - as a multilayer cylindrical wall. The values of the local heat transfer coefficients, determined from two approaches, were compared. Both approaches gave similar results.

  16. Transportation of MHD nanofluid free convection in a porous semi annulus using numerical approach

    Science.gov (United States)

    Sheikholeslami, M.; Ganji, D. D.

    2017-02-01

    Nanofluid free convection in presence of Lorentz forces in a permeable semi annulus is simulated using Control Volume based Finite Element Method. Impact of porous media on governing equations is considered by means of Darcy law. Brownian motion impact on properties of nanofluid is taken into account using Koo-Kleinstreuer-Li (KKL) model. Important parameters are inclination angle (ξ) , CuO-water volume fraction (ϕ) , Hartmann (Ha) and Rayleigh (Ra) numbers for porous medium. A formula for Nuave is provided. Results indicated that temperature gradient detracts with enhance of Ha but it enhances with rise of ξ, Ra . Heat transfer augmentation enhances with rise of Lorentz forces.

  17. Mixed convection aiding flow in a vertical porous annulus-two temperature model

    Science.gov (United States)

    Salman Ahmed, N. J.; AAAl-Rashed, Abdullah A.; Kamangar, Sarfaraz; Khaleed, H. M. T.; YunusKhan, T. M.; Athani, Abdulgaphur

    2016-09-01

    The effect of convective heat transfer on mixed convection flow in a vertical porous annulus embedded with fluid saturated porous medium for aiding flow is studied. The inner surface of the annular cylinder is heated with constant temperature whereas the outer surface remains at ambient temperature. The governing partial differential equations are solved using Finite Element Method (FEM). It is assumed that the Darcy law is applicable and thermal nonequilibrium TNE exists between solid and fluid phases of porous medium. The aiding flow behavior of heat transfer with respect to Radius ratioRr, Aspect ratio ArandRadiation parameter Rd for different values of Peclet number Peare investigated.

  18. The influence of horizontal boundaries on Ekman circulation and angular momentum transport in a cylindrical annulus

    Energy Technology Data Exchange (ETDEWEB)

    Obabko, Aleksandr V; Cattaneo, Fausto [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States); F Fischer, Paul [Division of Mathematics and Computer Science, Argonne National Laboratory, Argonne, IL 60439 (United States)], E-mail: obabko@uchicago.edu

    2008-12-15

    We present numerical simulations of circular Couette flow in axisymmetric and fully three-dimensional geometry of a cylindrical annulus inspired by Princeton magnetorotational instability (MRI) liquid gallium experiment. The incompressible Navier-Stokes equations are solved with the spectral element code Nek5000 incorporating realistic horizontal boundary conditions of differentially rotating rings. We investigate the effect of changing rotation rates (Reynolds number) and of the horizontal boundary conditions on flow structure, Ekman circulation and associated transport of angular momentum through the onset of unsteadiness and three-dimensionality. A mechanism for the explanation of the dependence of the Ekman flows and circulation on horizontal boundary conditions is proposed.

  19. Telephone switchboard closure | 19 December

    CERN Multimedia

    2014-01-01

    Exceptionally, the telephone switchboard will close at 4 p.m. on Friday, 19 December, instead of the usual time of 6 p.m., to allow time for closing all systems properly before the annual closure. Therefore, switchboard operator assistance to transfer calls from/to external lines will stop. All other phone services will run as usual.

  20. Abdominal wound closure: current perspectives

    Directory of Open Access Journals (Sweden)

    Williams ZF

    2015-12-01

    Full Text Available Zachary F Williams, William W Hope Department of Surgery, South East Area Health Education Center, New Hanover Regional Medical Center, Wilmington, NC, USA Abstract: This review examines both early and late wound complications following laparotomy closure, with particular emphasis on technical aspects that reduce hernia formation. Abdominal fascial closure is an area of considerable variation within the field of general surgery. The formation of hernias following abdominal wall incisions continues to be a challenging problem. Ventral hernia repairs are among the most common surgeries performed by general surgeons, and despite many technical advances in the field, incisional hernia rates remain high. Much attention and research has been directed to the surgical management of hernias. Less focus has been placed on prevention of hernia formation despite its obvious importance. This review examines the effects of factors such as the type of incision, suture type and size, closure method, patient risk factors, and the use of prophylactic mesh. Keywords: incisional, abdominal, hernia, prevention, wound closure techniques 

  1. Vacuum assisted closure in coloproctology

    NARCIS (Netherlands)

    Bemelman, W.A.

    2009-01-01

    Vacuum-assisted closure has earned its indications in coloproctology. It has been described with variable results in the treatment of large perineal defects after abdominoperineal excision, in the treatment of stoma dehiscence and perirectal abscesses. The most promising indication for

  2. Does the mitral annulus shrink or enlarge during systole? A real-time 3D echocardiography study.

    Science.gov (United States)

    Kwan, Jun; Jeon, Min-Jae; Kim, Dae-Hyeok; Park, Keum-Soo; Lee, Woo-Hyung

    2009-04-01

    This study was conducted to explore the geometrical changes of the mitral annulus during systole. The 3D shape of the mitral annulus was reconstructed in 13 normal subjects who had normal structure of the mitral apparatus using real-time 3D echocardiography (RT3DE) and 3D computer software. The two orthogonal (antero-posterior and commissure-commissure) dimensions, the areas (2D projected and 3D surface) and the non-planarity of the mitral annulus were estimated during early, mid and late systole. We demonstrated that the MA had a "saddle shape" appearance and it consistently enlarged mainly in the antero-posterior direction from early to late systole with lessening of its non-planarity, as was determined by 3D reconstruction using RT3DE and 3D computer software.

  3. The break of shielding current at pulsed field magnetization of a superconducting annulus (experiment and model simulation)

    Science.gov (United States)

    Korotkov, V. S.; Krasnoperov, E. P.; Kartamyshev, A. A.

    2017-09-01

    During the pulsed field magnetization of a high-T c annulus in liquid nitrogen the shielding current drops abruptly, providing rapid penetration of the magnetic flux into the hole of the superconductor. After the break of current the trapped field in the hole is small and negative although the body of the annulus remains highly magnetized. In the present work the current breaking effect is investigated both experimentally and numerically. The influence of the pulse parameter on the shielding current evolution during the break is researched. A simple model for the qualitative description of this process is proposed. The model shows the development of heating localized on the inhomogeneity of the high-temperature superconductor annulus providing the formation of a high resistive channel with temperature near to T c. The appearance of this hot channel leads to the rapid reduction of the shielding current and presents a new scenario of flux jump at high temperature.

  4. Creeping gaseous flows through elastic tube and annulus micro-configurations

    Science.gov (United States)

    Elbaz, Shai; Jacob, Hila; Gat, Amir

    2016-11-01

    Gaseous flows in elastic micro-configurations is relevant to biological systems (e.g. alveolar ducts in the lungs) as well as to applications such as gas actuated soft micro-robots. We here examine the effect of low-Mach-number compressibility on creeping gaseous axial flows through linearly elastic tube and annulus micro-configurations. For steady flows, the leading-order effects of elasticity on the pressure distribution and mass-flux are obtained. For transient flow in a tube with small deformations, elastic effects are shown to be negligible in leading order due to compressibility. We then examine transient flows in annular configurations where the deformation is significant compared with the gap between the inner and outer cylinders defining the annulus. Both compressibility and elasticity are obtained as dominant terms interacting with viscosity. For a sudden flux impulse, the governing non-linear leading order diffusion equation is initially approximated by a porous-medium-equation of order 2.5 for the pressure square. However, as the fluid expand and the pressure decreases, the governing equation degenerates to a porous-medium-equation of order 2 for the pressure.

  5. Melting of a phase change material in a horizontal annulus with discrete heat sources

    Directory of Open Access Journals (Sweden)

    Mirzaei Hooshyar

    2015-01-01

    Full Text Available Phase change materials have found many industrial applications such as cooling of electronic devices and thermal energy storage. This paper investigates numerically the melting process of a phase change material in a two-dimensional horizontal annulus with different arrangements of two discrete heat sources. The sources are positioned on the inner cylinder of the annulus and assumed as constant-temperature boundary conditions. The remaining portion of the inner cylinder wall as well as the outer cylinder wall is considered to be insulated. The emphasis is mainly on the effects of the arrangement of the heat source pair on the fluid flow and heat transfer features. The governing equations are solved on a non-uniform O type mesh using a pressure-based finite volume method with an enthalpy porosity technique to trace the solid and liquid interface. The results are obtained at Ra=104 and presented in terms of streamlines, isotherms, melting phase front, liquid fraction and dimensionless heat flux. It is observed that, depending on the arrangement of heat sources, the liquid fraction increases both linearly and non-linearly with time but will slow down at the end of the melting process. It can also be concluded that proper arrangement of discrete heat sources has the great potential in improving the energy storage system. For instance, the arrangement C3 where the heat sources are located on the bottom part of the inner cylinder wall can expedite the melting process as compared to the other arrangements.

  6. Posterior enlargement of the small annulus during aortic valve replacement versus implantation of a small prosthesis.

    Science.gov (United States)

    Pugliese, P; Bernabei, M; Santi, C; Pasqué, A; Eufrate, S

    1984-07-01

    Twenty-two patients with a small aortic annulus were identified among 196 consecutive patients undergoing aortic valve replacement (AVR). The 11 patients in Group 1 underwent posterior enlargement aortic annuloplasty, and the 11 in Group 2 received a small aortic prosthesis (less than or equal to 21 mm). The two groups were unselected. Core hypothermia, cardioplegia, and local cooling were employed for all operations. Isolated AVR was performed in 3 patients in each group. In Group 1, the mean increase in diameter of the annulus was 4.82 mm, which resulted in a mean area increase of 169.91 mm2 (51.7%). Mean aortic cross-clamp times were 140.4 minutes and 93.5 minutes in Groups 1 and 2, respectively. There were 2 operative deaths in Group 1, and 1 operative and 1 late death in Group 2. Mean follow-up was 26.5 months for Group 1 and 43.4 months for Group 2. No thomboembolic or bleeding episodes have been recorded. Considerations and conclusions are offered from the study of this small series of patients.

  7. Application of Regent mechanical valve in patients with small aortic annulus: 3-year follow-up

    Directory of Open Access Journals (Sweden)

    Zhao Dong

    2012-09-01

    Full Text Available Abstract Background Aortic valve replacement (AVR with a small aortic annulus is always challenging for the cardiac surgeon. In this study, we sought to evaluate the midterm performance of implantation with a 17-mm or 19-mm St. Jude Medical Regent (SJM Regent mechanical valve in retrospective consecutive cohort of patients with small aortic annulus (diameter ≤ 19 mm. Methods From January 2008 to April 2011, 40 patients (31 female, mean age = 47.2 ± 5.8 years with small aortic annulus (≤19 mm in diameter underwent aortic valve replacement with a 17-mm or 19-mm St. Jude Medical Regent (SJM Regent mechanical valve. Preoperative mean body surface area, New York Heart Association class, and mean aortic annulus were 1.61 ± 0.26 m2, 3.2 ± 0.4, and 18 ± 1.4 mm respectively. Patients were divided into two groups, according to the implantation of 17 mm SJM Regent mechanical valve (group 1, n = 18 or 19 mm SJM Regent valve (group 2, n = 22. All patients underwent echocardiography examination preoperatively and at one year post-operation. Results There were no early deaths in either group. Follow-up time averaged 36 ± 17.6 months. The mean postoperative New York Heart Association class was 1.3 ± 0.6 (p 2/m2 to 69.8 ± 9.3%, 41.4 ± 8.3%, and 0.92 ± 0.10 cm2/m2 respectively (P 2, 46.1 ± 8.5 mmHg to 86.7 ± 18.2 g/m2 , 13.7 ± 5.2 mmHg respectively. In group 2, the LVEF, LVFS and EOAI increased from 45.9% ± 9.7%, 30.7% ± 8.0%, and 0.81 ± 0.09 cm2/m2 to 77.4% ± 9.7%, 44.5% ± 9.6%, and 1.27 ± 0.11 cm2/m2 respectively, while the LVMI, and the aortic transvalvular pressure gradient decreased from 118.3 ± 27.6 g/m2, 44.0 ± 6.7 mmHg to 80.1 ± 19.7 g/m2, 10.8 ± 4.1 mmHg as well. The prevalence of PPM was documented in 2 patients in Group 1. Conclusions Patients with small aortic annulus and body surface

  8. 40 CFR 265.112 - Closure plan; amendment of plan.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Closure plan; amendment of plan. 265... DISPOSAL FACILITIES Closure and Post-Closure § 265.112 Closure plan; amendment of plan. (a) Written plan... have a written closure plan. Until final closure is completed and certified in accordance with §...

  9. COMPARATIVE STUDY OF LAPAROSCOPIC CLOSURE OPEN PEPTIC PERFORATION CLOSURE

    Directory of Open Access Journals (Sweden)

    Vivek

    2015-10-01

    Full Text Available Laparoscopic closure of perforated duodenal ulcer was first performed in the year 1990 . Due to its advantage of better view of the peritoneal cavity an opportunity for thorough lavage and avoidance of upper abdominal incision, with its related complication, especially in high – ri sk patients, this procedure has gained popularity all over the world. Approximately 10 - 20% of patients suffering from peptic ulcer develop perforation of stomach or duodenum in which, chemical peritonitis develop initially from gastric secretion and duoden al secretion the condition is life threatening. Early diagnosis and treatment is extremely important. Mortality will increase up if perforation exists more than 24 to 48 hours. Usually surgical intervention of simple closure with omental patch of the perforation is required. this study aims at evaluating efficacy , safety and outcome of laparoscopic surgery for perforated duodenal ulcer patients admitted during period Jan 2009 to Dec 2012 at tertiary hospital in north Karnataka A total of 61cases diagnosed as peritonitis secondary to duodenal ulcer perforation were involved in the study 30underwent open perforation closure and 31 cases underwent lap closure. Peptic ulcers are focal defects in the gastric or duodenal mucosa which extend into the sub mucosa or deeper. they may be acute or chronic and ultimately are caused by on imbalance between the action of peptic acid and mucosal defenses peptic ulcer remains a common outpatient diagnosis, but the number of elective operations for peptic ul cer disease have decreased dramatically over the past 30 decades due to the advent of H2 blockers However the incidence of emergency surgeries, and death rate associated with peptic ulcer are same

  10. Three dimensional evaluation of the aortic annulus using multislice computer tomography: Are manufacturer's guidelines for sizing for percutaneous aortic valve replacement helpful?

    NARCIS (Netherlands)

    C.J. Schultz (Carl); A. Moelker (Adriaan); N. Piazza (Nicolo); A. Tzikas (Apostolos); A. Otten (Amber); R-J.M. Nuis (Rutger-Jan); L.A.E. Neefjes (Lisan); R.J.M. van Geuns (Robert Jan); P.J. de Feyter (Pim); G.P. Krestin (Gabriel); P.W.J.C. Serruys (Patrick); P.P.T. de Jaegere (Peter)

    2010-01-01

    textabstractAimsTo evaluate the effects of applying current sizing guidelines to different multislice computer tomography (MSCT) aortic annulus measurements on Corevalve (CRS) size selection.Methods and resultsMultislice computer tomography annulus diameters [minimum: Dmin; maximum: Dmax; mean: Dmea

  11. Generalized Convective Quasi-Equilibrium Closure

    Science.gov (United States)

    Yano, Jun-Ichi; Plant, Robert

    2016-04-01

    Arakawa and Schubert proposed convective quasi-equilibrium as a basic principle for closing their spectrum mass-flux convection parameterization. In deriving this principle, they show that the cloud work function is a key variable that controls the growth of convection. Thus, this closure hypothesis imposes a steadiness of the cloud work function tendency. This presentation shows how this principle can be generalized so that it can also encompasses both the CAPE and the moisture-convergence closures. Note that the majority of the current mass-flux convection parameterization invokes a CAPE closure, whereas the moisture-convergence closure was extremely popular historically. This generalization, in turn, includes both closures as special cases of convective quasi-equilibrium. This generalization further suggests wide range of alternative possibilities for convective closure. In general, a vertical integral of any function depending on both large-scale and convective-scale variables can be adopted as an alternative closure variables, leading to an analogous formulation as Arakawa and Schubert's convective quasi-equilibrium formulation. Among those, probably the most fascinating possibility is to take a vertical integral of the convective-scale moisture for the closure. Use of a convective-scale variable for closure has a particular appeal by not suffering from a loss of predictability of any large-scale variables. That is a main problem with any of the current convective closures, not only for the moisture-convergence based closure as often asserted.

  12. Closure constraints for hyperbolic tetrahedra

    CERN Document Server

    Charles, Christoph

    2015-01-01

    We investigate the generalization of loop gravity's twisted geometries to a q-deformed gauge group. In the standard undeformed case, loop gravity is a formulation of general relativity as a diffeomorphism-invariant SU(2) gauge theory. Its classical states are graphs provided with algebraic data. In particular closure constraints at every node of the graph ensure their interpretation as twisted geometries. Dual to each node, one has a polyhedron embedded in flat space R^3. One then glues them allowing for both curvature and torsion. It was recently conjectured that q-deforming the gauge group SU(2) would allow to account for a non-vanishing cosmological constant Lambda, and in particular that deforming the loop gravity phase space with real parameter q>0 would lead to a generalization of twisted geometries to a hyperbolic curvature. Following this insight, we look for generalization of the closure constraints to the hyperbolic case. In particular, we introduce two new closure constraints for hyperbolic tetrahe...

  13. The Synthesis of Force Closure Grasps in the Plane.

    Science.gov (United States)

    1985-09-01

    TASK U Artificial Inteligence Laboratory AREA A WORK UN IT "NMUIERS ~( 545 Technology Square Cambridge, MA 02139 SI. CONTROLLING OFICE NAME ANO... ARTIFICIAL INThLLIX’ ENCE LABORATORY A. 1. Memo 861 September, 1985 The Synthesis of Force-Closure Grasps In the Plane DTIC ’VeL% ,#ECTE 1 VnDcNguyenU Abstract... Artificial In- telligenmcc Liabomatory of thle Massachuset Is hInsttute of Teclhnolog3 . Support for the Lahoratot * s Artificial Intelligence research is

  14. Current perspectives in percutaneous atrial septal defect closure devices

    Directory of Open Access Journals (Sweden)

    Bissessor N

    2015-07-01

    Full Text Available N Bissessor1–4 1Department of Cardiology, The Epworth Hospital, Melbourne, VIC, Australia; 2Division of Interventional Cardiology, The Alfred Hospital, Melbourne, VIC, Australia; 3Department of Clinical Science, Charles Sturt University Albury Campus, NSW, Australia; 4Heart Foundation, Griffith University, QLD, Australia Abstract: In the last decade, percutaneous atrial septal defect (ASD closure has become the treatment of choice in most clinical presentations of ASD. Percutaneous ASD closure has established procedural safety through operator experience and improved device structure and deliverability. There have also been advances in diagnostic capabilities. Devices have evolved from large bulky meshes to repositionable, minimal residual mesh content that easily endothelializes and conforms well to surrounding structures. Biodegradable technology has been introduced and will be closely watched as a future option. The evolution of ASD closure device usage in the last four decades incorporates development that minimizes a wide range of serious side effects that have been reported over the years. Complications reported in the literature include thrombus formation, air embolization, device embolization, erosions, residual shunts, and nickel hypersensitivity. Modern devices have intermediate to long term data with outcomes that have been favorable. Devices are available in multiple sizes with improved delivery mechanisms to recapture, reposition, and safely close simple and complex ASDs amenable to percutaneous closure. In this review, commonly used devices and deployment procedures are discussed together with a look at devices that show promise for the future. Keywords: ASD, congenital, Amplatzer, Gore Helex, Biostar, Figulla

  15. Device Closure of Small Ventricular Septal Defects: When and Why?

    Directory of Open Access Journals (Sweden)

    IB Vijayalakshmi

    2014-10-01

    Full Text Available Ventricular septal defect (VSD accounts for approximately 20-30 % of all forms of congenital heart disease (CHD. They were traditionally closed surgically in the past. The surgery though safe carries the risk of morbidity, complete heart block, wound infection and thoracotomy scar on the chest. On weighing the risk and benefit, the small VSDs were not submitted to surgery in the past. So for many years it has been taught that the small VSDs are to be left alone and surgery is not recommended. Many clinicians believed in spontaneous closure of VSDs. Hence they advised the parents to wait for spontaneous closure till the child is 9 years old. But what if the VSD does not close by 10 years is the question. Are they normal as grown up congenital heart (GUCH. The Jane Somerville GUCH unit showed that spontaneous closure occurred only in 10% between the age of 17 and 45 (mean - 27 years in small VSDs in adults. What is worth noting is about 25% had serious complications: infective endocarditis (11%, progressive aortic regurgitation (5%, age-related symptomatic arrhythmias (8.5% like atrial fibrillation. This means that asymptomatic small VSDs in childhood is not necessarily benign during adult life. This raises the question, when we have a safe non-surgical device closure available to close the small VSDs, should we put the future lives of the young in danger by not giving the benefit of technology to them?

  16. Analysis of optical vortices with suppressed sidelobes using modified Bessel-like function and trapezoid annulus modulation structures.

    Science.gov (United States)

    Guo, Jian; Wei, Zhongchao; Liu, Yuebo; Huang, Aili

    2015-02-01

    Two amplitude modulation methods, including modified Bessel-like function modulation structure and trapezoid annulus structure, for suppressing sidelobes of optical vortices are studied. In the former approach, we propose that the order of the Bessel-like function can be an additional parameter to modulate diffraction patterns of optical vortices motivated by the idea of conventional annulus structures. Furthermore, new Bessel-like modulation functions are introduced to solve the problem of low diffraction efficiency of the original one. Trapezoid annulus structure is proposed as a compromise structure between the modified Bessel-like modulation structure and the conventional annulus one, and has advantages of both. It is demonstrated that these two approaches can achieve high-quality optical vortices with suppressed sidelobes effectively, and the relative structures behave as more flexible and applicable structures for producing optical vortices with large coverage of topological charges, which suggests great potential in simplifying the structure designing procedure. These reliable and generalized structures for generating high-quality optical vortices will help to promote the development of future optical communication and optical manipulation significantly.

  17. Transesophageal echocardiography measurements of aortic annulus diameter using biplane mode in patients undergoing transcatheter aortic valve implantation

    Directory of Open Access Journals (Sweden)

    Shahgaldi Kambiz

    2013-01-01

    Full Text Available Abstract Background Aortic stenosis (AS is a relevant common valve disorder. Severe AS and symptoms and/or left ventricular dysfunction (EF Aim of the study is to assess the aortic annulus diameter in patients undergoing TAVI by biplane (BP mode using transesophageal echocardiography (TEE and compare it to two-dimensional (2D transthoracic echocardiography (TTE and 2DTEE using three-dimensional (3D TEE as reference method. Methods The study population consisted of 50 patients retrospectively (24 men and 26 women, mean age 85±8 years of age who all had undergone echocardiography examination prior to TAVI. Results The mean aortic annulus diameter was 20.4±2.2 mm with TTE, 22.3±2.5 mm with 2DTEE, 22.9±1.9 mm with BP-mode and 23.1±1.9 mm with 3DTEE. TTE underestimated the mean aortic annulus diameter in comparison to transesophageal imaging modalities (p Conclusion A multi-dimensional method is preferred to assess aortic annulus diameter in TAVI patients since there is risk of underestimation using single plane. Biplane mode is the method of choice in view of speedy post-processing with no need for expensive dedicated software. Lastly, single plane methods lead to misclassification of patients as unsuitable for TAVI. This may be of major clinical importance.

  18. Penetrating annulus fibrosus injuries affect dynamic compressive behaviors of the intervertebral disc via altered fluid flow: an analytical interpretation.

    Science.gov (United States)

    Michalek, Arthur J; Iatridis, James C

    2011-08-01

    Extensive experimental work on the effects of penetrating annular injuries indicated that large injuries impact axial compressive properties of small animal intervertebral discs, yet there is some disagreement regarding the sensitivity of mechanical tests to small injury sizes. In order to understand the mechanism of injury size sensitivity, this study proposed a simple one dimensional model coupling elastic deformations in the annulus with fluid flow into and out of the nucleus through both porous boundaries and through a penetrating annular injury. The model was evaluated numerically in dynamic compression with parameters obtained by fitting the solution to experimental stress-relaxation data. The model predicted low sensitivity of mechanical changes to injury diameter at both small and large sizes (as measured by low and high ratios of injury diameter to annulus thickness), with a narrow range of high sensitivity in between. The size at which axial mechanics were most sensitive to injury size (i.e., critical injury size) increased with loading frequency. This study provides a quantitative hypothetical model of how penetrating annulus fibrosus injuries in discs with a gelatinous nucleus pulposus may alter disc mechanics by changing nucleus pulposus fluid pressurization through introduction of a new fluid transport pathway though the annulus. This model also explains how puncture-induced biomechanical changes depend on both injury size and test protocol.

  19. Aortic valve replacement for aortic stenosis with a small aortic annulus in a patient having Werner's syndrome and liver cirrhosis.

    Science.gov (United States)

    Sogawa, M; Kasuya, S; Yamamoto, K; Koshika, M; Oguma, F; Hayashi, J

    2001-12-01

    Werner's syndrome is a rare genetic disease characterized by premature aging and scleroderma-like involvement of the skin. We report a case of aortic valve replacement for severely calcified aortic valve stenosis with a small annulus in a patient suffering from Werner's syndrome and liver cirrhosis

  20. Burn-out, Circumferential Film Flow Distribution and Pressure Drop for an Eccentric Annulus with Heated Rod

    DEFF Research Database (Denmark)

    Andersen, P. S.; Jensen, A.; Mannov, G.

    1974-01-01

    Measurements of (1) burn-out, (2) circumferential film flow distribution, and (3) pressure drop in a 17 × 27.2 × 3500 mm concentric and eccentric annulus geometry are presented. The eccentric displacement was varied between 0 and 3 mm. The working fluid was water. Burn-out curves at 70 bar...... flow variation on burn-out is discussed....

  1. Numerical simulation of solidification in a horizontal cylindrical annulus charged with an aqueous salt solution

    Science.gov (United States)

    Neilson, D. G.; Incropera, F. D.; Bennon, W. D.

    1990-01-01

    A computational study of solidification of a binary Na2CO3 solution in a horizontal cylindrical annulus is performed using a continuum formulation with a control-volume based, finite-difference scheme. The initial conditions were selected to facilitate the study of counter thermal and solutal convection, accompanied by extensive mushy region growth. Numerical results are compared with experimental data with mixed success. Qualitative agreement is obtained for the overall solidification process and associated physical phenomena. However, the plume thickness calculated for the solutally-driven convective upflow is substantially smaller than the observed value. Evolution of double-diffusive layers is predicted, but over a time scale much smaller than that observed experimentally. Good agreement is obtained between predicted and measured results for solid growth, but the mushy region thickness is significantly overpredicted.

  2. Effects of nanoparticles on the peristaltic motion of tangent hyperbolic fluid model in an annulus

    Directory of Open Access Journals (Sweden)

    S. Nadeem

    2015-12-01

    Full Text Available In the present article, effects of nanoparticles on the peristaltic flow of tangent hyperbolic fluid in an annulus are described. The two-dimensional equations of tangent hyperbolic fluid are solved by using the assumptions of low Reynolds number and long wavelength. Analytical solution is obtained with the help of homotopy perturbation and Adomian decomposition method for velocity, temperature and nanoparticles concentration. Solutions are discussed through graphs. Solutions for pressure rise, temperature, nanoparticles concentration, pressure gradient and streamlines are plotted for various emerging parameters. It is found that the temperature profile increases with increase in Brownian motion and thermophoresis parameter. It is also found that the size of the trapped bolus in triangular wave is smaller as compared to other waves. Further, the comparison of both analytical solutions is presented.

  3. Experimental study on convective boiling heat transfer in narrow-gap annulus tubes

    Institute of Scientific and Technical Information of China (English)

    LI Bin; ZHAO Jian-Fu; ZHOU Fang-De; TANG Ze-Mei; HU Wen-Rui

    2004-01-01

    Since convective boiling or highly subcooled single-phase forced convection in micro-channels is an effective cooling mechanism with a wide range of applications, more experimental and theoretical studies are required to explain and verify the forced convection heat transfer phenomenon in narrow channels. In this experimental study, we model the convective boiling behavior of water with low latent heat substance Freon 113 (R-113), with the purpose of saving power consumption and visualizing experiments. Both heat transfer and pressure drop characteristics were measured in subcooled and saturated concentric narrow gap forced convection boiling. Data were obtained to qualitatively identify the effects of gap size, pressure, flow rate and wall superheat on boiling regimes and the transition between various regimes. Some significant differences from unconfined forced convection boiling were found,and also, the flow patterns in narrow vertical annulus tubes have been studied quantitatively.

  4. Curvature effects on axisymmetric instability of conduction regime in a tall air-filled annulus

    Science.gov (United States)

    Pécheux, J.; Le Quéré, P.; Abcha, F.

    1994-10-01

    This paper numerically studies curvature effects on the instability of the conduction regime of natural convection in a tall air-filled differentially heated annulus of vertical aspect ratio 16 by integrating the two-dimensional axisymmetric Navier-Stokes equations in the Boussinesq approximation. The numerical algorithm combines a pseudospectral Chebyshev space discretization with a second-order time-stepping scheme. It is shown that, in contrast with linear stability analysis of the conduction solution, the time-periodic cross-roll instability does not take place in finite aspect ratio cavities for small values of the radius ratio. For all values of the radius ratio transition to unsteadiness occurs through supercritical Hopf bifurcations. Extensive computations show very complex behaviors of the unsteady solutions depending on the radius ratio. The nature of the reverse transition to steady state that occurs for increasing value of the Rayleigh number is also found to depend strongly on the value of the radius ratio.

  5. Hydromagnetic convection in a rotating annulus with an azimuthal magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Kurt, E.; Busse, F.H.; Pesch, W. [University of Bayreuth, Institute of Physics, Bayreuth (Germany)

    2004-11-01

    The problem of convection induced by radial buoyancy in an electrically conducting fluid contained by a rotating cylindrical annulus (angular frequency, {omega}) in the presence of a homogeneous magnetic field (B) in the azimuthal direction is considered. The small gap approximation is used together with rigid cylindrical boundaries. The onset of convection occurs in the form of axial, axisymmetric or oblique rolls. The angle {psi} between the roll axis and the axis of rotation depends of the ratio between the Chandrasekhar number, Q{proportional_to}B{sup 2}, and the Coriolis number, {tau}{proportional_to}{omega}. Fully three-dimensional numerical simulations as well as Galerkin representations for roll patterns including the subsequent stability analysis are used in the theoretical investigation. At finite amplitudes, secondary transitions to 3D-hexarolls and to spatio-temporal chaos are found. Overlapping regions of pattern stability exist such that the asymptotically realized state may depend on the initial conditions. (orig.)

  6. Mixed Convection Opposing Flow in a Vertical Porous Annulus-Two Temperature Model

    Science.gov (United States)

    Al-Rashed, Abdullah A. AA; J, Salman Ahmed N.; Khaleed, H. M. T.; Yunus Khan, T. M.; NazimAhamed, K. S.

    2016-09-01

    The opposing flow in a porous medium refers to a condition when the forcing velocity flows in opposite direction to thermal buoyancy obstructing the buoyant force. The present research refers to the effect of opposing flow in a vertical porous annulus embedded with fluid saturated porous medium. The thermal non-equilibrium approach with Darcy modal is considered. The boundary conditions are such that the inner radius is heated with constant temperature Tw the outer radius is maintained at constant temperature Tc. The coupled nonlinear partial differential equations such as momentum equation, energy equation for fluid and energy equation for solid are solved using the finite element method. The opposing flow variation of average Nusselt number with respect to radius ratio Rr, Aspect ratioAr and Radiation parameter Rd for different values of Peclet number Pe are investigated. It is found that the flow behavior is quite different from that of aiding flow.

  7. A linear analysis of the transition curve for the baroclinic annulus

    Science.gov (United States)

    Miller, T. L.; Gall, R. L.

    1983-01-01

    A primitive equation linear model is shown to be capable of quantitatively predicting the neutral curve for a baroclinic annulus. Flows unstable to small nonaxisymmetric perturbations are assumed to lie on the nonaxisymmetric side of a transition curve, while the stable flows are on the axisymmetric side. The stability in the presence of perturbations is tested with linearized hydrostatic primitive equations. Attention is given to the fastest growing eigenmodes, demonstrating that the linear and nonlinear wave have similar structures at a particular point in the nonaxisymmetric regime. All the waves are similar to the Eddy wave except at the extreme to the transition curve, where the waves maintain little structure with height. The eddy kinetic energy is baroclinic with a potential energy suppresed by the large static stability of the basic state. Eddy dissipation is noted to be significant near all boundaries.

  8. Double-diffusive convection in a rotating cylindrical annulus with conical caps

    CERN Document Server

    Simitev, R D

    2011-01-01

    Double-diffusive convection driven by both thermal and compositional buoyancy in a rotating cylindrical annulus with conical caps is considered with the aim to establish whether a small fraction of compositional buoyancy added to the thermal buoyancy (or vice versa) can significantly reduce the critical Rayleigh number and amplify convection in planetary cores. It is shown that the neutral surface describing the onset of convection in the double-buoyancy case is essentially different from that of the well-studied purely thermal case, and does indeed allow the possibility of low-Rayleigh number convection. In particular, isolated islands of instability are formed by an additional "double-diffusive" eigenmode in certain regions of the parameter space. However, the amplitude of such low-Rayleigh number convection is relatively weak. At similar flow amplitudes purely compositional and double-diffusive cases are characterized by a stronger time dependence compared to purely thermal cases, and by a prograde mean zo...

  9. Automatic mitral annulus tracking in volumetric ultrasound using non-rigid image registration.

    Science.gov (United States)

    De Veene, Henri; Bertrand, Philippe B; Popovic, Natasa; Vandervoort, Pieter M; Claus, Piet; De Beule, Matthieu; Heyde, Brecht

    2015-01-01

    Analysis of mitral annular dynamics plays an important role in the diagnosis and selection of optimal valve repair strategies, but remains cumbersome and time-consuming if performed manually. In this paper we propose non-rigid image registration to automatically track the annulus in 3D ultrasound images for both normal and pathological valves, and compare the performance against manual tracing. Relevant clinical properties such as annular area, circumference and excursion could be extracted reliably by the tracking algorithm. The root-mean-square error, calculated as the difference between the manually traced landmarks (18 in total) and the automatic tracking, was 1.96 ± 0.46 mm over 10 valves (5 healthy and 5 diseased) which is within the clinically acceptable error range.

  10. A numerical study of entrance region in a curved annulus with an inward and outward eccentricity

    Directory of Open Access Journals (Sweden)

    M.R.H. Nobari

    2016-09-01

    Full Text Available In this article, developing incompressible fluid flow in a curved annulus with inward and outward eccentricities is studied numerically. To do so, a second order finite difference method based on the projection algorithm is employed to solve the governing equations written in a general bipolar–toroidal coordinate system using a three-dimensional staggered uniform grid. The effects of the governing dimensionless parameters such as the Dean number, Reynolds number, curvature ratio, aspect ratio, and eccentricity on the flow field pattern and friction factor are studied in the entrance region. The numerical results obtained indicate that the outward eccentricity significantly deforms the secondary flows and axial velocity profiles. Furthermore, as the eccentricity increases, the friction factor decreases due to the reduction of secondary flow intensity.

  11. Risk of Cerebral Embolization with Caseous Calcification of the Mitral Annulus: Review Article

    Science.gov (United States)

    Dietl, Charles A.; Hawthorn, Christopher M.; Raizada, Veena

    2016-01-01

    Background: Caseous calcification of the mitral annulus (CCMA) is believed to have a benign prognosis. Several authors have recommended conservative management in asymptomatic patients. However, the prevalence of cerebrovascular events (CVE) in patients with CCMA has never been evaluated before. The aims of this study are to investigate whether patients with CCMA are at increased risk of cerebral embolization, and to determine whether elective surgical resection of CCMA should be considered to prevent a cardioembolic stroke. Methods: A comprehensive literature search was obtained from MEDLINE via PubMed.gov, ScienceDirect.com, and Google Scholar using the following search queries: caseous calcification of the mitral annulus, intracardiac pseudotumor, mitral annular calcification, and cardioembolic stroke. Results: From our initial search that yielded 1,502 articles, we identified a total of 130 patients with CCMA reported in 86 publications. Literature review revealed that the prevalence of CVE associated with CCMA is 19.2% (25 of 130) which is significantly higher than the prevalence of CVE reported with mitral annular calcification (MAC), 11.8% (214 of 1818) (range 4.8% to 24.1%) (P = 0.01796) (odds ratio = 1.78; 0.95 confidence interval = 1.1278 – 2.8239). Only four of 25 (16.0%) patients with CCMA who suffered a CVE had history of atrial fibrillation (AF). Conclusion: Based on our review, it would be reasonable to consider elective surgical resection of CCMA in asymptomatic patients who are good surgical candidates, because patients with CCMA may be at increased risk of embolic strokes, which are unrelated to AF. PMID:27990181

  12. Association of mitral annulus calcification, aortic valve calcification with carotid intima media thickness

    Directory of Open Access Journals (Sweden)

    Scuteri Angelo

    2004-10-01

    Full Text Available Abstract Background Mitral annular calcification (MAC and aortic annular calcification (AVC may represent a manifestation of generalized atherosclerosis in the elederly. Alterations in vascular structure, as indexed by the intima media thickness (IMT, are also recognized as independent predictors of adverse cardiovascular outcomes. Aim To examine the relationship between the degree of calcification at mitral and/or aortic valve annulus and large artery structure (thickness. Methods We evaluated 102 consecutive patients who underwent transthoracic echocardiography and carotid artery echoDoppler for various indications; variables measured were: systemic blood pressure (BP, pulse pressure (PP=SBP-DBP, body mass index (BMI, fasting glucose, total, HDL, LDL chlolesterol, triglycerides, cIMT. The patients were divided according to a grading of valvular/annular lesions independent scores based on acoustic densitometry: 1 = annular/valvular sclerosis/calcification absence; 2 = annular/valvular sclerosis; 3 = annular calcification; 4 = annular-valvular calcification; 5 = valvular calcification with no recognition of the leaflets. Results Patient score was the highest observed for either valvular/annulus. Mean cIMT increased linearly with increasing valvular calcification score, ranging from 3.9 ± 0.48 mm in controls to 12.9 ± 1.8 mm in those subjects scored 5 (p 0.0001. Conclusion MAC and AVC score can identify subgroups of patients with different cIMT values which indicate different incidence and prevalence of systemic artery diseases. This data may confirm MAC-AVC as a useful important diagnostic parameter of systemic atherosclerotic disease.

  13. Pulmonary annulus preservation lowers the risk of late postoperative pulmonary valve implantation after the repair of tetralogy of Fallot.

    Science.gov (United States)

    Kim, Gwan Sic; Han, Seungbong; Yun, Tae-Jin

    2015-02-01

    The long-term benefits of pulmonary annulus preservation in tetralogy of Fallot (ToF) repair in patients with a marginally small pulmonary annulus are controversial. We sought to determine whether pulmonary annulus preservation (AP) is superior to transannular patching (TAP) in lowering the risk of pulmonary valve implantation (PVI) long after the repair of ToF. Of the 255 patients who underwent total correction of ToF during infancy between January 1989 and December 2005, 114 patients (AP group = 57, TAP group = 57) were selected by propensity score matching for various preoperative variables, such as age and body weight at operation, sex, pulmonary artery size, pre-repair palliation, anatomical types of ventricular septal defect, and Z-score of pulmonary valve annulus diameter (PVA-Z). The PVA-Z of the AP and TAP groups were -2.3 ± 1.3 and -2.1 ± 1.3, respectively (p = 0.547). The time to PVI was compared between the two groups. The median follow-up duration was 146 months (AP group: 141 months, TAP group: 147 months; p = 0.191). During the follow-up periods, there were 12 reoperations for the relief of right ventricular outflow tract obstruction (RVOTO), eight PVIs, and three late deaths. While freedom from reoperation for RVOTO was comparable between the two groups (p = 0.182), freedom from PVI at postoperative 15 years was significantly lower in the TAP group than in the AP group (74 and 100 %, p = 0.015). In repairing ToF with marginally small pulmonary valve annulus, AP is associated with a lower risk of late postoperative PVI.

  14. Targeting the annulus fibrosus of the intervertebral disc: Col1a2-Cre(ER)T mice show specific activity of Cre recombinase in the outer annulus fibrosus.

    Science.gov (United States)

    Bedore, Jake; Quesnel, Katherine; Quinonez, Diana; Séguin, Cheryle A; Leask, Andrew

    2016-06-01

    Degeneration of the intervertebral disc (IVD) is a major underlying contributor to back pain-the single leading cause of disability worldwide. However, we possess a limited understanding of the etiology underlying IVD degeneration. To date, there are a limited number of mouse models that have been used to target proteins in specific compartments of the IVD to explore their functions in disc development, homeostasis and disease. Furthermore, the majority of reports exploring the composition and function of the outer encapsulating annulus fibrosus (AF) of the IVD have considered it as one tissue, without considering the numerous structural and functional differences existing between the inner and outer AF. In addition, no mouse models have yet been reported that enable specific targeting of genes within the outer AF. In the current report, we discuss these issues and demonstrate the localized activity of Cre recombinase in the IVD of Col1a2-Cre(ER)T;ROSA26mTmG mice possessing a tamoxifen-dependent Cre recombinase driven by a Cola2 promoter and distal enhancer and the mTmG fluorescent reporter. Following tamoxifen injection of 3-week-old Col1a2-Cre(ER)T;ROSA26mTmG mice, we show Cre activity specifically in the outer AF of the IVD, as indicated by expression of the GFP reporter. Thus, Col1a2-Cre(ER)T;ROSA26mTmG mice may prove to be a valuable tool in delineating the function of proteins in this unique compartment of the IVD, and in further exploring the compositional differences between the inner and outer AF in disc homeostasis, aging and disease.

  15. 组织工程椎间盘纤维环:如何更接近于天然%How to build a tissue-engineered intervertebral disc annulus fibrosus that is more close to the natural one?

    Institute of Scientific and Technical Information of China (English)

    袁德超; 陈竹; 冯大雄; 冯刚

    2015-01-01

    BACKGROUND:Tissue-engineered intervertebral disc has provided a new biological therapeutic approach for intervertebral disc degeneration. Tissue-engineered annulus fibrosus is one key step of constructing a complete tissue-engineered intervertebral disc. OBJECTIVE:To sum up the research progress of tissue-engineered annulus fibrosus from the folowing aspects: structural features, scaffold materials, seed cels. METHODS:PubMed database and Wanfang database (2000-2015) were retrieved by the key words of “tissue engineering, intervertebral disc, annulus fibrosus, seed cel, scaffold, construction” in Chinese and in English, respectively. According to inclusion and exclusion criteria, 48 literatures were involved for summarization. RESULTS AND CONCLUSION: Previous studies about tissue-engineered annulus fibrosus only focused on cel adhesion, proliferation and extracelular matrix secretion on the scaffold. Currently, tissue-engineered annulus fibrosus exhibit similar features to the natural annulus fibrosus in the folowing aspects: cel function, tissue structure and mechanical features, and relevant animal experiments have achieved certain results in animal experiments. However, it is stil difficult to build a tissue-engineered annulus fibrosus entirely similar to the natural one, and we need to further improve scaffold materials, culture conditions, colection of seed cels. The current strategies of annulus fibrosus construction stil focus on single phase of scaffold, and the biphasic scaffold and complete intervertebral disc scaffold wil be the trend of the researches. Technology of induced differentiation of stem cels provides a broach source of seed cels for tissue-engineered annulus fibrosus.%背景:组织工程椎间盘为椎间盘退行性变疾病的生物治疗提供了新的方法,组织工程纤维环是构建组织工程椎间盘的关键之一。目的:从纤维环结构特点、材料支架、种子细胞3方面,归纳总结组织工程纤维环

  16. Closure constraints for hyperbolic tetrahedra

    Science.gov (United States)

    Charles, Christoph; Livine, Etera R.

    2015-07-01

    We investigate the generalization of loop gravity's twisted geometries to a q-deformed gauge group. In the standard undeformed case, loop gravity is a formulation of general relativity as a diffeomorphism-invariant SU(2) gauge theory. Its classical states are graphs provided with algebraic data. In particular, closure constraints at every node of the graph ensure their interpretation as twisted geometries. Dual to each node, one has a polyhedron embedded in flat space {{{R}}3}. One then glues them, allowing for both curvature and torsion. It was recently conjectured that q-deforming the gauge group SU(2) would allow us to account for a non-vanishing cosmological constant Λ \

  17. 100-D Ponds closure plan. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, S.W.

    1997-09-01

    The 100-D Ponds is a Treatment, Storage, and Disposal (TSD) unit on the Hanford Facility that received both dangerous and nonregulated waste. This Closure Plan (Rev. 1) for the 100-D Ponds TSD unit consists of a RCRA Part A Dangerous Waste Permit Application (Rev. 3), a RCRA Closure Plan, and supporting information contained in the appendices to the plan. The closure plan consists of eight chapters containing facility description, process information, waste characteristics, and groundwater monitoring data. There are also chapters containing the closure strategy and performance standards. The strategy for the closure of the 100-D Ponds TSD unit is clean closure. Appendices A and B of the closure plan demonstrate that soil and groundwater beneath 100-D Ponds are below cleanup limits. All dangerous wastes or dangerous waste constituents or residues associated with the operation of the ponds have been removed, therefore, human health and the environment are protected. Discharges to the 100-D Ponds, which are located in the 100-DR-1 operable unit, were discontinued in June 1994. Contaminated sediment was removed from the ponds in August 1996. Subsequent sampling and analysis demonstrated that there is no contamination remaining in the ponds, therefore, this closure plan is a demonstration of clean closure.

  18. 40 CFR 264.112 - Closure plan; amendment of plan.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Closure plan; amendment of plan. 264... Closure and Post-Closure § 264.112 Closure plan; amendment of plan. (a) Written plan. (1) The owner or operator of a hazardous waste management facility must have a written closure plan. In addition,...

  19. Structural determinants of hospital closure.

    Science.gov (United States)

    Longo, D R; Chase, G A

    1984-05-01

    In a retrospective case-control study, structural characteristics of hospitals that closed during the years 1976-1980 were contrasted with three comparison groups: hospitals that were acquired in a merger; hospitals that joined a multihospital system; and hospitals that remained autonomously opened, to investigate these characteristics as predictors of closure. Characteristics investigated included environmental, structural, and process variables. The independent variables were measured 5 years prior to outcome. Findings indicate that closed hospitals resemble hospitals acquired in a merger ("failure"), and likewise autonomous hospitals resemble hospitals that join a multihospital system ("success"). The most important predictors of hospital failure were the physician-to-population ratio, the East North Central and West North Central census regions, the level of diversification, low occupancy rate, location in a standard metropolitan statistical area, the chief executive officer's lack of affiliation in the American College of Hospital Administrators, profit status, bed size of less than 50, and presence in a state with a rate-setting agency. Surprisingly, this study shows the bed-to-population ratio to be unrelated to closure. In addition, the findings strongly support the open-system perspective, which, unlike the closed-system perspective, is concerned with the vulnerability of the organization to the uncontrollable and often unpredictable influences of the environment.

  20. Genetic, epigenetic, and environmental contributions to neural tube closure.

    Science.gov (United States)

    Wilde, Jonathan J; Petersen, Juliette R; Niswander, Lee

    2014-01-01

    The formation of the embryonic brain and spinal cord begins as the neural plate bends to form the neural folds, which meet and adhere to close the neural tube. The neural ectoderm and surrounding tissues also coordinate proliferation, differentiation, and patterning. This highly orchestrated process is susceptible to disruption, leading to neural tube defects (NTDs), a common birth defect. Here, we highlight genetic and epigenetic contributions to neural tube closure. We describe an online database we created as a resource for researchers, geneticists, and clinicians. Neural tube closure is sensitive to environmental influences, and we discuss disruptive causes, preventative measures, and possible mechanisms. New technologies will move beyond candidate genes in small cohort studies toward unbiased discoveries in sporadic NTD cases. This will uncover the genetic complexity of NTDs and critical gene-gene interactions. Animal models can reveal the causative nature of genetic variants, the genetic interrelationships, and the mechanisms underlying environmental influences.

  1. Biaxial testing of canine annulus fibrosus tissue under changing salt concentrations

    Directory of Open Access Journals (Sweden)

    Jacques M. Huyghe

    2010-03-01

    Full Text Available The in vivo mechanics of the annulus fibrosus of the intervertebral disc is one of biaxial rather than uniaxial loading. The material properties of the annulus are intimately linked to the osmolarity in the tissue. This paper presents biaxial relaxation experiments of canine annulus fibrosus tissue under stepwise changes of external salt concentration. The force tracings show that stresses are strongly dependent on time, salt concentration and orientation. The force tracing signature of are sponse to a change instrain, is one of a jumpin stress that relaxes partly as the new strain is maintained. The force tracing signature of a stepwise change in salt concentration is a progressive monotonous change in stress towards a new equilibrium value. Although the number of samples does not allow any definitive quantitative conclusions, the trends may shed light on the complex interaction among the directionality of forces, strains and fiber orientation on one hand, and on the other hand, the osmolarity of the tissue. The dual response to a change in strain is understood as an immediate response before fluid flows in or out of the tissue, followed by a progressive readjustment of the fluid content in time because of the gradient in fluid chemical potential between the tissue and the surrounding solution.A mecânica in vivo do anel fibroso do disco intervertebral é baseada em carregamento biaxial ao invés de uniaxial. As propriedades materiais do anel estão intimamente ligadas à osmolaridade no tecido. O artigo apresenta experimentos de relaxação biaxiais do anel fibroso de um tecido canino sob mudanças abruptas na concentração externa de sal. A assinatura da força devido à mudança brusca de salinidade resulta em uma progressiva e monótona mudança na tensão em direção a um novo valor de equilíbrio. Embora o número de amostras não permita nenhuma conclusão quantitativa, as tendências podem abrir uma luz no entendimento das intera

  2. 40 CFR 264.178 - Closure.

    Science.gov (United States)

    2010-07-01

    ... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Use and Management of Containers § 264.178 Closure. At closure, all hazardous waste and hazardous waste residues must be removed...

  3. 40 CFR 264.351 - Closure.

    Science.gov (United States)

    2010-07-01

    ... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Incinerators § 264.351 Closure. At closure the owner or operator must remove all hazardous waste and hazardous waste...

  4. 50 CFR 665.666 - Closures.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Closures. 665.666 Section 665.666 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION... § 665.666 Closures. (a) If the Regional Administrator determines that the harvest quota for any...

  5. Key financial ratios can foretell hospital closures.

    Science.gov (United States)

    Lynn, M L; Wertheim, P

    1993-11-01

    An analysis of various financial ratios sampled from open and closed hospitals shows that certain leverage, liquidity, capital efficiency, and resource availability ratios can predict hospital closure up to two years in advance of the closure with an accuracy of nearly 75 percent.

  6. Spontaneous closure of traumatic tympanic membrane perforations

    DEFF Research Database (Denmark)

    Jellinge, Marlene Ersgaard; Kristensen, S.; Larsen, K

    2015-01-01

    BACKGROUND: The treatment of traumatic tympanic membrane perforations varies in different investigations, ranging from observation to early surgical repair. The present study aimed to focus on the closure rate and the closure time in a group of patients treated with a watchful waiting policy. MET...

  7. Acute angle closure glaucoma following ileostomy surgery

    Directory of Open Access Journals (Sweden)

    Mariana Meirelles Lopes

    2015-02-01

    Full Text Available Angle-closure glaucoma can be induced by drugs that may cause pupillary dilatation. We report a case of a patient that developed bilateral angle closure glaucoma after an ileostomy surgery because of systemic atropine injection. This case report highlights the importance of a fast ophthalmologic evaluation in diseases with ocular involvement in order to make accurate diagnoses and appropriate treatments.

  8. 环空流体吸入式自激振荡脉冲射流大涡模拟研究%Large eddy simulation of self-oscillation pulsed water jet drawing in annulus fluid

    Institute of Scientific and Technical Information of China (English)

    杜玉昆; 王瑞和; 倪红坚

    2009-01-01

    发展新型破岩钻井技术对于促进油气田高效开发具有重要意义,高压水射流是提高破岩钻井效率的一个重要手段,脉冲射流是一种高效射流形式.为了充分利用井底水力能量,提出了一种环空流体吸入式脉冲射流的技术构想.基于自激振荡原理设计了相应射流调制工具,并对工具的流场和动力学特性进行了大涡模拟研究.研究结果分析揭示了环空流体吸入式自激振荡脉冲射流调制的机理,并发现合理的水力结构可以在振荡腔内实现局部负压,使得环空流体被吸入,参与调制生成高效脉冲射流.与非吸入式脉冲射流相比,吸入式脉冲射流振荡更加剧烈,破岩能力更强.研究结果得到了实验验证,为实际钻井工具的研制和相关工艺技术的开发提供了依据.%It is of great significance that developing new rock breaking drilling technology to promote efficient exploit of oil field. High pressure water jet drilling technology is an important method to promote the rock breaking drilling efficiency, and pulsed water jet is such a kind of high efficiency water jet. In order to take full advantage of hydraulic energy in bottom hole, a concept of new type of pulsed water jet drawing in annulus flow, is put forward. The pulsed water jet modulation tool is designed based on the self-exciting principle, and the large eddy simulation is adopted to simulate the flow field and the dynamic characteristics in this tool. This simulation shows the modulation mechanism of self-exciting pulsed water jet drawing in annulus flow. Partial negative pressure could be achieved in the oscillating cavity if the reasonable hydraulic structure is applied. The negative pressure formed in the drawing entrance of the oscillating cavity provides assurance to automatically draw enough fluid into annulus flow, which takes part in modulating the efficient pulsed water jet. The amplitude is larger and the rock breaking capacity of

  9. Characteristics of turbulent heat transfer in an annulus at supercritical pressure

    Science.gov (United States)

    Peeters, J. W. R.; Pecnik, R.; Rohde, M.; van der Hagen, T. H. J. J.; Boersma, B. J.

    2017-02-01

    Heat transfer to fluids at supercritical pressure is different from heat transfer at lower pressures due to strong variations of the thermophysical properties with the temperature. We present and analyze results of direct numerical simulations of heat transfer to turbulent CO2 at 8 MPa in an annulus. Periodic streamwise conditions are imposed so that mean streamwise acceleration due to variations in the density does not occur. The inner wall of the annulus is kept at a temperature of 323 K, while the outer wall is kept at a temperature of 303 K. The pseudocritical temperature Tp c=307.7 K, which is the temperature where the thermophysical properties vary the most, can be found close to the inner wall. This work is a continuation of an earlier study, in which turbulence attenuation due to the variable thermophysical properties of a fluid at supercritical pressure was studied. In the current work, the direct effects of variations in the specific heat capacity, thermal diffusivity, density, and the molecular Prandtl number on heat transfer are investigated using different techniques. Variations in the specific heat capacity cause significant differences between the mean nondimensionalized temperature and enthalpy profiles. Compared to the enthalpy fluctuations, temperature fluctuations are enhanced in regions with low specific heat capacity and diminished in regions with a large specific heat capacity. The thermal diffusivity causes local changes to the mean enthalpy gradient, which in turn affects molecular conduction of thermal energy. The turbulent heat flux is directly affected by the density, but it is also affected by the mean molecular Prandtl number and attenuated or enhanced turbulent motions. In general, enthalpy fluctuations are enhanced in regions with a large mean molecular Prandtl number, which enhances the turbulent heat flux. While analyzing the Nusselt numbers under different conditions it is found that heat transfer deterioration or enhancement can

  10. Multivariate statistical data analysis methods for detecting baroclinic wave interactions in the thermally driven rotating annulus

    Science.gov (United States)

    von Larcher, Thomas; Harlander, Uwe; Alexandrov, Kiril; Wang, Yongtai

    2010-05-01

    Experiments on baroclinic wave instabilities in a rotating cylindrical gap have been long performed, e.g., to unhide regular waves of different zonal wave number, to better understand the transition to the quasi-chaotic regime, and to reveal the underlying dynamical processes of complex wave flows. We present the application of appropriate multivariate data analysis methods on time series data sets acquired by the use of non-intrusive measurement techniques of a quite different nature. While the high accurate Laser-Doppler-Velocimetry (LDV ) is used for measurements of the radial velocity component at equidistant azimuthal positions, a high sensitive thermographic camera measures the surface temperature field. The measurements are performed at particular parameter points, where our former studies show that kinds of complex wave patterns occur [1, 2]. Obviously, the temperature data set has much more information content as the velocity data set due to the particular measurement techniques. Both sets of time series data are analyzed by using multivariate statistical techniques. While the LDV data sets are studied by applying the Multi-Channel Singular Spectrum Analysis (M - SSA), the temperature data sets are analyzed by applying the Empirical Orthogonal Functions (EOF ). Our goal is (a) to verify the results yielded with the analysis of the velocity data and (b) to compare the data analysis methods. Therefor, the temperature data are processed in a way to become comparable to the LDV data, i.e. reducing the size of the data set in such a manner that the temperature measurements would imaginary be performed at equidistant azimuthal positions only. This approach initially results in a great loss of information. But applying the M - SSA to the reduced temperature data sets enable us to compare the methods. [1] Th. von Larcher and C. Egbers, Experiments on transitions of baroclinic waves in a differentially heated rotating annulus, Nonlinear Processes in Geophysics

  11. Flow regime development analysis in adiabatic upward two-phase flow in a vertical annulus

    Energy Technology Data Exchange (ETDEWEB)

    Julia, J. Enrique [Departamento de Ingenieria Mecanica y Construccion, Universitat Jaume I, Campus de Riu Sec, Castellon 12071 (Spain); Ozar, Basar [School of Nuclear Engineering, Purdue University, 400 Central Dr., West Lafayette, IN 47907-2017 (United States); Jeong, Jae-Jun [Korea Atomic Energy Research Institute, 150 Dukjin, Yuseong, Daejeon 305-353 (Korea, Republic of); Hibiki, Takashi [School of Nuclear Engineering, Purdue University, 400 Central Dr., West Lafayette, IN 47907-2017 (United States); Ishii, Mamoru, E-mail: ishii@purdue.ed [School of Nuclear Engineering, Purdue University, 400 Central Dr., West Lafayette, IN 47907-2017 (United States)

    2011-02-15

    In this work radial and axial flow regime development in adiabatic upward air-water two-phase flow in a vertical annulus has been investigated. Local flow regimes have been identified using conductivity probes and neural networks techniques. The inner and outer diameters of the annulus are 19.1 mm and 38.1 mm, respectively. The equivalent hydraulic diameter of the flow channel, D{sub H}, is 19.0 mm and the total length is 4.37 m. The flow regime map includes 1080 local flow regimes identifications in 72 flow conditions within a range of 0.01 m/s < < 30 m/s and 0.2 m/s < < 3.5 m/s where and are, respectively, superficial gas and liquid velocities. The local flow regime has been classified into four categories: bubbly, cap-slug, churn-turbulent and annular flows. In order to study the radial and axial development of flow regime the measurements have been performed at five radial locations. The three axial positions correspond to z/D{sub H} = 52, 149 and 230, where z represents the axial position. The flow regime indicator has been chosen as some statistical parameters of local bubble chord length distributions and self-organized neural networks have been used as mapping system. This information has been also used to compare the results given by the existing flow regime transition models. The local flow regime is characterized basically by the void fraction and bubble chord length. The radial development of flow regime shows partial and complete local flow regime combinations. The radial development is controlled by axial location and superficial liquid velocity. The radial flow regime transition is always initiated in the center of the flow channel and it is propagated towards the channel boundaries. The axial development of flow regime is observed in all the flow maps and it is governed by superficial liquid velocity and radial location. The prediction results of the models are compared for each flow regime transition.

  12. [Dehiscence of the Pericardial Patch, after Surgical Treatment of Active Infective Aortic Valve Endocarditis with Reconstruction of the Aortic Annulus Using a Glutaraldehyde-treated Autologous Pericardium].

    Science.gov (United States)

    Yoshida, Kazufumi; Fukunaga, Naoto; Koizumi, Shigeki; Nishiya, Kenta; Matsuda, Yasuhiro; Ishigami, Masanosuke; Nagasawa, Atsushi; Sakata, Ryuzo; Koyama, Tadaaki

    2017-03-01

    A 50-year-old man was admitted with fever and chill sensation 6 months ago. Transthoracic echocardiography (TTE) showed left and right coronary cusp prolapses and a thickened tissue of the aortic curtain. Congestive heart failure due to active infective aortic valve endocarditis was diagnosed, and he underwent aortic valve replacement. The aortic annulus was reconstructed using a glutaraldehydetreated autologous pericardium. Six months after surgery, TTE showed severe aortic regurgitation and saccular change in the aortic annulus. Transesophageal echocargiography showed some echo free space from left to noncoronary cusp and abnormal movement of the prosthetic valve annulus. Intraoperative examination showed dehiscence of the pericardial patch from the aortic wall, but no finding of infection. Aortic valve rereplacement was performed with reconstruction of the aortic annulus using a bovine pericardium. To prevent the dehiscence of the pericardial patch from the aortic wall, sutures fixing the prosthetic valve were passed from outside of the aortic wall.

  13. Intermittent acute angle closure glaucoma and chronic angle closure following topiramate use with plateau iris configuration

    Directory of Open Access Journals (Sweden)

    Rajjoub LZ

    2014-07-01

    Full Text Available Lamise Z Rajjoub, Nisha Chadha, David A Belyea Department of Ophthalmology, The George Washington University, Washington, DC, USA Abstract: This is a case report describing recurrent intermittent acute angle closure episodes in the setting of topiramate use in a female suffering from migraines. Despite laser peripheral iridotomy placement for the pupillary block component, and the discontinuation of topiramate, the acute angle closure did not resolve in the left eye with chronic angle closure and the patient required urgent trabeculectomy. The right eye responded to laser peripheral iridotomy immediately and further improved after the cessation of topiramate. While secondary angle closure glaucoma due to topiramate use has been widely reported, its effects in patients with underlying primary angle closure glaucoma have not been discussed. Our report highlights the importance of recognizing the often multifactorial etiology of angle closure glaucoma to help guide clinical management. Keywords: angle closure glaucoma, plateau iris, topiramate, secondary glaucoma, drug-induced glaucoma

  14. INVESTIGATION ON THE FLOW STABILITY OF NEWTONIAN FLUID IN ECCENTRIC ANNULUS VIA THE AXIAL RECIPROCATION OF THE INNER TUBE

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The governing equation, together with the formulas of the averaged flux and the stability parameter for Newtonian fluid flowing in eccentric annulus via the axial reciprocation of the inner tube was established in the bipolar coordinate system. Numerical calculation was conducted for the measurement of water flow using the formulas above, of which the results agree well with the experimental data. It is shown that the flow instability can be induced by the increase of the stroke, the frequency, and the eccentricity of annulus, making the sucker rod more susceptible to partial abrasion. Some protecting methods, including adding centralizers, adjusting the stroke and frequency, are proposed to protect the sucker rod from the partial abrasion, and satisfactory results have been achieved in the oilfields.

  15. Recurrent discrete subaortic stenosis and small aortic annulus successfully repaired by the Konno procedure in a young woman.

    Science.gov (United States)

    Kashima, Ichiro; Ueda, Toshihiko; Katogi, Toshiyuki; Taguchi, Shinichi; Inoue, Yoshito; Koizumi, Kiyoshi

    2006-10-01

    A 24-year-old woman who had undergone excision of the membrane for discrete subaortic stenosis when 6 years old displayed recurrent subaortic stenosis and had a small aortic annulus, with a peak pressure gradient of 60mmHg. We chose to perform the Konno operation with a mechanical valve. This released the left ventricular outflow tract obstruction adequately, and she recovered uneventfully with New York Heart Association functional class I. In our experience, an aggressive strategy such as myectomy is an appropriate initial procedure for preventing recurrence when the geometry of the problem may lead to recurrence in the left ventricular outflow tract. The Konno operation is a good option for recurrent subaortic stenosis with small aortic annulus.

  16. Experimental research on heat transfer to liquid sodium and its incipient boiling wall superheat in an annulus

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Liquid sodium is mainly used as a cooling fluid in the liquid metal fast breeder reactor (LMFBR), whose heat transfer, whether convective heat transfer or boiling heat transfer, is different from that of water. So it is important for both normal and accidental operations of LMFBR to perform experimental research on heat transfer to liquid sodium and its boiling heat transfer. This study deals with heat transfer with high temperature (300-700℃) and low Pe number (20~70) and heat transfer with low temperature (250~270℃) and high Pe number (125~860), and its incipient boiling wall superheat in an annulus. Research on heat transfer involves theoretical research and experiments on heat transfer to liquid sodium. It also focuses on the theoretical analysis and experimental research on its incipient boiling wall superheat at positive pressure in an annulus. Semiempirical correlations were obtained and they were well coincident with the experimental data.

  17. Closure of Microcosm for refurbishment

    CERN Multimedia

    2014-01-01

    Since 1994, the Microcosm exhibition has given the opportunity to visitors of all ages and backgrounds to have a first glimpse into the secrets of physics.   To ensure that Microcosm can continue fulfilling its educational aims at the same level of quality for many years to come, it is closing for renovation work on 8 December 2014 and is expected to reopen during Summer 2015. During the closure, the “Fun with Physics” workshop will not take place, but the Universe of Particles exhibition in the Globe and the Passport to the Big Bang circuit will remain accessible to the public, free of charge and with no need to book in advance.  Guided tours of CERN are also available (advance booking required via this page).

  18. Closure for milliliter scale bioreactor

    Science.gov (United States)

    Klein, David L.; Laidlaw, Robert D.; Andronaco, Gregory; Boyer, Stephen G.

    2010-12-14

    A closure for a microreactor includes a cap that is configured to be inserted into a well of the microreactor. The cap, or at least a portion of the cap, is compliant so as to form a seal with the well when the cap is inserted. The cap includes an aperture that provides an airway between the inside of the well to the external environment when the cap is inserted into the well. A porous plug is inserted in the aperture, e.g., either directly or in tube that extends through the aperture. The porous plug permits gas within the well to pass through the aperture while preventing liquids from passing through to reduce evaporation and preventing microbes from passing through to provide a sterile environment. A one-way valve may also be used to help control the environment in the well.

  19. Cardiovascular magnetic resonance as a reliable alternative to cardiovascular computed tomography and transesophageal echocardiography for aortic annulus valve sizing.

    Science.gov (United States)

    Faletti, Riccardo; Gatti, Marco; Salizzoni, Stefano; Bergamasco, Laura; Bonamini, Rodolfo; Garabello, Domenica; Marra, Walter Grosso; La Torre, Michele; Morello, Mara; Veglia, Simona; Fonio, Paolo; Rinaldi, Mauro

    2016-08-01

    To assess the accuracy and reproducibly of cardiovascular magnetic resonance (CMR) in the measurement of the aortic annulus and in process of valve sizing as compared to intra-operative sizing, cardiovascular computed tomography (CCT) and transesophageal echocardiography (TEE). Retrospective study on 42 patients who underwent aortic valve replacement from September 2010 to September 2015, with available records of pre surgery annulus assessment by CMR, CCT and TEE and of peri-operative assessment. In CCT and CMR, the annular plane was considered a virtual ring formed by the lowest hinge points of the valvular attachments to the aorta. In TEE the annulus was measured at the base of leaflet insertion in the mid-esophageal long-axis view using the X-plane technique. Two double-blinded operators performed the assessments for each imaging technique. Intra-operative evaluation was performed using Hegar dilators. Continuous variables were studied with within-subject ANOVA, Bland-Altman (BA) plots, Wilcoxon's and Friedman's tests; trends were explored with scatter plots. Categorical variables were studied with Fisher's exact test. The intra- and inter-operator reliability was satisfying. There were no significant differences between the annulus dimensions measured by CMR and either one of the three references. Valve sizing for CoreValve by CMR had the same good agreement with CCT and TEE, with a 78 % match rate; for SAPIEN XT the agreement was slightly better (82 %) for CCT than for TEE (66 %). MR performs well when compared to the surgical reference of intra-operative sizing and stands up to the level of the most used imaging references (CCT and TEE).

  20. Penetrating Annulus Fibrosus Injuries Affect Dynamic Compressive Behaviors of the Intervertebral Disc Via Altered Fluid Flow: An Analytical Interpretation

    OpenAIRE

    Michalek, Arthur J.; Iatridis, James C.

    2011-01-01

    Extensive experimental work on the effects of penetrating annular injuries indicated that large injuries impact axial compressive properties of small animal intervertebral discs, yet there is some disagreement regarding the sensitivity of mechanical tests to small injury sizes. In order to understand the mechanism of injury size sensitivity, this study proposed a simple one dimensional model coupling elastic deformations in the annulus with fluid flow into and out of the nucleus through both ...

  1. Annulus Fibrosus Can Strip Hyaline Cartilage End Plate from Subchondral Bone: A Study of the Intervertebral Disk in Tension.

    Science.gov (United States)

    Balkovec, Christian; Adams, Michael A; Dolan, Patricia; McGill, Stuart M

    2015-10-01

    Study Design Biomechanical study on cadaveric spines. Objective Spinal bending causes the annulus to pull vertically (axially) on the end plate, but failure mechanisms in response to this type of loading are poorly understood. Therefore, the objective of this study was to identify the weak point of the intervertebral disk in tension. Methods Cadaveric motion segments (aged 79 to 88 years) were dissected to create midsagittal blocks of tissue, with ∼10 mm of bone superior and inferior to the disk. From these blocks, 14 bone-disk-bone slices (average 4.8 mm thick) were cut in the frontal plane. Each slice was gripped by its bony ends and stretched to failure at 1 mm/s. Mode of failure was recorded using a digital camera. Results Of the 14 slices, 10 failed by the hyaline cartilage being peeled off the subchondral bone, with the failure starting opposite the lateral annulus and proceeding medially. Two slices failed by rupturing of the trabecular bone, and a further two failed in the annulus. Conclusions The hyaline cartilage-bone junction is the disk's weak link in tension. These findings provide a plausible mechanism for the appearance of bone and cartilage fragments in herniated material. Stripping cartilage from the bony end plate would result in the herniated mass containing relatively stiff cartilage that does not easily resorb.

  2. The Development of a Gas-Liquid Two-Phase Flow Sensor Applicable to CBM Wellbore Annulus.

    Science.gov (United States)

    Wu, Chuan; Wen, Guojun; Han, Lei; Wu, Xiaoming

    2016-11-18

    The measurement of wellbore annulus gas-liquid two-phase flow in CBM (coalbed methane) wells is of great significance for reasonably developing gas drainage and extraction processes, estimating CBM output, judging the operating conditions of CBM wells and analyzing stratum conditions. Hence, a specially designed sensor is urgently needed for real-time measurement of gas-liquid two-phase flow in CBM wellbore annulus. Existing flow sensors fail to meet the requirements of the operating conditions of CBM wellbore annulus due to such factors as an inapplicable measurement principle, larger size, poor sealability, high installation accuracy, and higher requirements for fluid media. Therefore, based on the principle of a target flowmeter, this paper designs a new two-phase flow sensor that can identify and automatically calibrate different flow patterns of two-phase flows. Upon the successful development of the new flow sensor, lab and field tests were carried out, and the results show that the newly designed sensor, with a measurement accuracy of ±2.5%, can adapt to the operating conditions of CBM wells and is reliable for long-term work.

  3. Structure of recombinant capsids formed by the beta-annulus deletion mutant -- rCP (Delta48-59) of Sesbania mosaic virus.

    Science.gov (United States)

    Pappachan, Anju; Subashchandrabose, Chinnathambi; Satheshkumar, P S; Savithri, H S; Murthy, M R N

    2008-05-25

    A unique feature of several T=3 icosahedral viruses is the presence of a structure called the beta-annulus formed by extensive hydrogen bonding between protein subunits related by icosahedral three-fold axis of symmetry. This unique structure has been suggested as a molecular switch that determines the T=3 capsid assembly. In order to examine the importance of the beta-annulus, a deletion mutant of Sesbania mosaic virus coat protein in which residues 48-59 involved in the formation of the beta-annulus were deleted retaining the rest of the residues in the amino terminal segment (rCP (Delta48-59)) was constructed. When expressed in Escherichia coli, the mutant protein assembled into virus like particles of sizes close to that of the wild type virus particles. The purified capsids were crystallized and their three dimensional structure was determined at 3.6 A resolution by X-ray crystallography. The mutant capsid structure closely resembled that of the native virus particles. However, surprisingly, the structure revealed that the assembly of the particles has proceeded without the formation of the beta-annulus. Therefore, the beta-annulus is not essential for T=3 capsid assembly as speculated earlier and may be formed as a consequence of the particle assembly. This is the first structural demonstration that the virus particle morphology with and without the beta-annulus could be closely similar.

  4. CFD Calculation of Internal Natural Convection in the Annulus between Horizontal Concentric Cylinders

    Energy Technology Data Exchange (ETDEWEB)

    N.D. Francis, Jr; M.T. Itamura; S.W. Webb; D.L. James

    2002-10-01

    The objective of this heat transfer and fluid flow study is to assess the ability of a computational fluid dynamics (CFD) code to reproduce the experimental results, numerical simulation results, and heat transfer correlation equations developed in the literature for natural convection heat transfer within the annulus of horizontal concentric cylinders. In the literature, a variety of heat transfer expressions have been developed to compute average equivalent thermal conductivities. However, the expressions have been primarily developed for very small inner and outer cylinder radii and gap-widths. In this comparative study, interest is primarily focused on large gap widths (on the order of half meter or greater) and large radius ratios. From the steady-state CFD analysis it is found that the concentric cylinder models for the larger geometries compare favorably to the results of the Kuehn and Goldstein correlations in the Rayleigh number range of about 10{sup 5} to 10{sup 8} (a range that encompasses the laminar to turbulent transition). For Rayleigh numbers greater than 10{sup 8}, both numerical simulations and experimental data (from the literature) are consistent and result in slightly lower equivalent thermal conductivities than those obtained from the Kuehn and Goldstein correlations.

  5. Forced Convective Condensation of Nonazeotropic Refrigerant Mixtures in Horizontal Annulus with Petal Shaped Fin Tubes

    Institute of Scientific and Technical Information of China (English)

    WangShiping; ZhouXinqiu; 等

    1995-01-01

    In this paper,condensation performance in horizontal annulus was compared with a smooth tube,one Saw-Tooth Finned tube(STF tube),four Petal Shaped Fin tubes(PF tubes),using R113,R11 and their mixtures(vapor molar fractions of R11 at the test section inlet were 0.384,0.588and 0.809) as working fluid.The mass flux at the test section ranged from 15-220/m2s。Camera and video camera were used to shoot the flow pattern and condensation phenomena.The condensation transfer coefficient(hc) of mixtures were considerably lower than those of pure fluid,and did not change linearly with composition.The maximum degradation of measured hc from the ideal value were 23% for the smooth tube,65%for STF tube,67% for PF tubes,which occurred in the composition range of 0.4-0.6 vapor molar fraction of R11.For the condensation of mixture,R11 molar fraction from 38%to 81%,the PF tubes had the highest value of hc.which were 10-25% higher than those of STF tubes,and 480-580% higher than that of smooth tube,because the petal shaped fins of PF tubes could promote strong turbulence in the two phase flow,and reduce the mass transfer resistance.

  6. Identification of Mitral Annulus Hinge Point Based on Local Context Feature and Additive SVM Classifier

    Directory of Open Access Journals (Sweden)

    Jianming Zhang

    2015-01-01

    Full Text Available The position of the hinge point of mitral annulus (MA is important for segmentation, modeling and multimodalities registration of cardiac structures. The main difficulties in identifying the hinge point of MA are the inherent noisy, low resolution of echocardiography, and so on. This work aims to automatically detect the hinge point of MA by combining local context feature with additive support vector machines (SVM classifier. The innovations are as follows: (1 designing a local context feature for MA in cardiac ultrasound image; (2 applying the additive kernel SVM classifier to identify the candidates of the hinge point of MA; (3 designing a weighted density field of candidates which represents the blocks of candidates; and (4 estimating an adaptive threshold on the weighted density field to get the position of the hinge point of MA and exclude the error from SVM classifier. The proposed algorithm is tested on echocardiographic four-chamber image sequence of 10 pediatric patients. Compared with the manual selected hinge points of MA which are selected by professional doctors, the mean error is in 0.96 ± 1.04 mm. Additive SVM classifier can fast and accurately identify the MA hinge point.

  7. Identification of Mitral Annulus Hinge Point Based on Local Context Feature and Additive SVM Classifier.

    Science.gov (United States)

    Zhang, Jianming; Liu, Yangchun; Xu, Wei

    2015-01-01

    The position of the hinge point of mitral annulus (MA) is important for segmentation, modeling and multimodalities registration of cardiac structures. The main difficulties in identifying the hinge point of MA are the inherent noisy, low resolution of echocardiography, and so on. This work aims to automatically detect the hinge point of MA by combining local context feature with additive support vector machines (SVM) classifier. The innovations are as follows: (1) designing a local context feature for MA in cardiac ultrasound image; (2) applying the additive kernel SVM classifier to identify the candidates of the hinge point of MA; (3) designing a weighted density field of candidates which represents the blocks of candidates; and (4) estimating an adaptive threshold on the weighted density field to get the position of the hinge point of MA and exclude the error from SVM classifier. The proposed algorithm is tested on echocardiographic four-chamber image sequence of 10 pediatric patients. Compared with the manual selected hinge points of MA which are selected by professional doctors, the mean error is in 0.96 ± 1.04 mm. Additive SVM classifier can fast and accurately identify the MA hinge point.

  8. Age estimation for shovelnose sturgeon: A cautionary note based on annulus formation in pectoral fin rays

    Science.gov (United States)

    Whiteman, K.W.; Travnichek, V.H.; Wildhaber, M.L.; DeLonay, A.; Papoulias, D.; Tillett, D.

    2004-01-01

    Numerous studies have examined the age and growth of shovelnose sturgeon Scaphirhynchus platorynchus, but only one study attempted to validate age estimation techniques. Therefore, our objective was to use marginal increment analysis to validate annulus formation in pectoral fin rays of shovelnose sturgeon collected from the Missouri River. We also compared the precision of age estimates between two different readers. Marginal increment distance indicated that for most of the populations an opaque band was laid down in pectoral fin rays during the summer. However, opaque bands were formed throughout the year in some individuals, which could be problematic when using fin rays for age estimation. The agreement of age estimates by two readers for shovelnose sturgeon was only 18%, and differences in ages between the two readers increased for older fish. The presence of split annuli, false annuli, spawning bands, imbedded rays, and deteriorating sections made individual growth rings difficult to separate. Our findings verified that opaque bands are formed annually during the summer in the pectoral fin rays of most shovelnose sturgeon, but some individuals form opaque bands during other times. Pectoral fin rays will probably continue to be the most practical method of age estimation in shovelnose sturgeon, but ages estimated by this method should be used with caution.

  9. Chaotic micromixer utilizing electro-osmosis and induced charge electro-osmosis in eccentric annulus

    Science.gov (United States)

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

    2016-06-01

    Efficient mixing is of significant importance in numerous chemical and biomedical applications but difficult to realize rapidly in microgeometries due to the lack of turbulence. We propose to enhance mixing by introducing Lagrangian chaos through electro-osmosis (EO) or induced charge electro-osmosis (ICEO) in an eccentric annulus. The analysis reveals that the created Lagrangian chaos can achieve a homogeneous mixing much more rapidly than either the pure EO or the pure ICEO. Our systematic investigations on the key parameters, ranging from the eccentricity, the alternating time period, the number of flow patterns in one time period, to the specific flow patterns utilized for the Lagrangian chaos creation, present that the Lagrangian chaos is considerably robust. The system can obtain a good mixing effect with wide ranges of eccentricity, alternating time period, and specific flow patterns utilized for the Lagrangian chaos creation as long as the number of flow patterns in one time period is two. As the electric field increases, the time consumption for homogenous mixing is reduced more remarkably for the Lagrangian chaos of the ICEO than that of the EO.

  10. Ultrastructure of inclusion bodies in annulus cells in the degenerating human intervertebral disc.

    Science.gov (United States)

    Gruber, H E; Hanley, E N

    2009-06-01

    The rough endoplasmic reticulum (rER) of the cell has an architectural editing function that checks whether protein structure and three-dimensional assembly have occurred properly prior to export of newly synthesized material out of the cell. If these have been faulty, the material is retained within the rER as an inclusion body. Inclusion bodies have been identified previously in chondrocytes and osteoblasts in chondrodysplasias and osteogenesis imperfecta. Inclusion bodies in intervertebral disc cells, however, have only recently been recognized. Our objectives were to use transmission electron microscopy to analyze more fully inclusion bodies in the annulus pulposus and to study the extracellular matrix (ECM) surrounding cells containing inclusion bodies. ECM frequently encapsulated cells with inclusion bodies, and commonly contained prominent banded aggregates of Type VI collagen. Inclusion body material had several morphologies, including relatively smooth, homogeneous material, or a rougher, less homogeneous feature. Such findings expand our knowledge of the fine structure of the human disc cell and ECM during disc degeneration, and indicate the potential utility of ultrastructural identification of discs with intracellular inclusion bodies as a screening method for molecular studies directed toward identification of defective gene products in degenerating discs.

  11. Preclinical positron emission tomography scanner based on a monolithic annulus of scintillator: initial design study.

    Science.gov (United States)

    Stolin, Alexander V; Martone, Peter F; Jaliparthi, Gangadhar; Raylman, Raymond R

    2017-01-01

    Positron emission tomography (PET) scanners designed for imaging of small animals have transformed translational research by reducing the necessity to invasively monitor physiology and disease progression. Virtually all of these scanners are based on the use of pixelated detector modules arranged in rings. This design, while generally successful, has some limitations. Specifically, use of discrete detector modules to construct PET scanners reduces detection sensitivity and can introduce artifacts in reconstructed images, requiring the use of correction methods. To address these challenges, and facilitate measurement of photon depth-of-interaction in the detector, we investigated a small animal PET scanner (called AnnPET) based on a monolithic annulus of scintillator. The scanner was created by placing 12 flat facets around the outer surface of the scintillator to accommodate placement of silicon photomultiplier arrays. Its performance characteristics were explored using Monte Carlo simulations and sections of the NEMA NU4-2008 protocol. Results from this study revealed that AnnPET's reconstructed spatial resolution is predicted to be [Formula: see text] full width at half maximum in the radial, tangential, and axial directions. Peak detection sensitivity is predicted to be 10.1%. Images of simulated phantoms (mini-hot rod and mouse whole body) yielded promising results, indicating the potential of this system for enhancing PET imaging of small animals.

  12. Photobiomodulation on human annulus fibrosus cells during the intervertebral disk degeneration: extracellular matrix-modifying enzymes.

    Science.gov (United States)

    Hwang, Min Ho; Kim, Kyoung Soo; Yoo, Chang Min; Shin, Jae Hee; Nam, Hyo Geun; Jeong, Jin Su; Kim, Joo Han; Lee, Kwang Ho; Choi, Hyuk

    2016-05-01

    Destruction of extracellular matrix (ECM) leads to degeneration of the intervertebral disk (IVD), which is a major contributor to many spine disorders. IVD degeneration is induced by pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β), which are secreted by immune cells, including macrophages and neutrophils. The cytokines modulate ECM-modifying enzymes such as matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in human annulus fibrosus (AF) cells. The resulting imbalance in catabolic and anabolic enzymes can cause generalized back, neck, and low back pain (LBP). Photobiomodulation (PBM) is known to regulate inflammatory responses and wound healing. The aim of this study was to mimic the degenerative IVD microenvironment, and to investigate the effect of a variety of PBM conditions (wavelength: 635, 525, and 470 nm; energy density: 16, 32, and 64 J/cm(2)) on the production of ECM-modifying-enzymes by AF cells under degenerative conditions induced by macrophage-conditioned medium (MCM), which contains pro-inflammatory cytokines such as TNF-α and IL-β secreted by macrophage during the development of intervertebral disk inflammation. We showed that the MCM-stimulated AF cells express imbalanced ratios of TIMPs (TIMP-1 and TIMP-2) and MMPs (MMP-1 and MMP-3). PBM selectively modulated the production of ECM-modifying enzymes in AF cells. These results suggest that PBM can be a therapeutic tool for degenerative IVD disorders.

  13. Mechanics of oriented electrospun nanofibrous scaffolds for annulus fibrosus tissue engineering.

    Science.gov (United States)

    Nerurkar, Nandan L; Elliott, Dawn M; Mauck, Robert L

    2007-08-01

    Engineering a functional replacement for the annulus fibrosus (AF) of the intervertebral disc is contingent upon recapitulation of AF structure, composition, and mechanical properties. In this study, we propose a new paradigm for AF tissue engineering that focuses on the reconstitution of anatomic fiber architecture and uses constitutive modeling to evaluate construct function. A modified electrospinning technique was utilized to generate aligned nanofibrous polymer scaffolds for engineering the basic functional unit of the AF, a single lamella. Scaffolds were tested in uniaxial tension at multiple fiber orientations, demonstrating a nonlinear dependence of modulus on fiber angle that mimicked the nonlinearity and anisotropy of native AF. A homogenization model previously applied to native AF successfully described scaffold mechanical response, and parametric studies demonstrated that nonfibrillar matrix, along with fiber connectivity, are key contributors to tensile mechanics for engineered AF. We demonstrated that AF cells orient themselves along the aligned scaffolds and deposit matrix that contributes to construct mechanics under loading conditions relevant to the in vivo environment. The homogenization model was applied to cell-seeded constructs and provided quantitative measures for the evolution of matrix and interfibrillar interactions. Finally, the model demonstrated that at fiber angles of the AF (28 degrees -44 degrees ), engineered material behaved much like native tissue, suggesting that engineered constructs replicate the physiologic behavior of the single AF lamella. Constitutive modeling provides a powerful tool for analysis of engineered AF neo-tissue and native AF tissue alike, highlighting key mechanical design criteria for functional AF tissue engineering.

  14. 3D segmentation of annulus fibrosus and nucleus pulposus from T2-weighted magnetic resonance images

    Science.gov (United States)

    Castro-Mateos, Isaac; Pozo, Jose M.; Eltes, Peter E.; Del Rio, Luis; Lazary, Aron; Frangi, Alejandro F.

    2014-12-01

    Computational medicine aims at employing personalised computational models in diagnosis and treatment planning. The use of such models to help physicians in finding the best treatment for low back pain (LBP) is becoming popular. One of the challenges of creating such models is to derive patient-specific anatomical and tissue models of the lumbar intervertebral discs (IVDs), as a prior step. This article presents a segmentation scheme that obtains accurate results irrespective of the degree of IVD degeneration, including pathological discs with protrusion or herniation. The segmentation algorithm, employing a novel feature selector, iteratively deforms an initial shape, which is projected into a statistical shape model space at first and then, into a B-Spline space to improve accuracy. The method was tested on a MR dataset of 59 patients suffering from LBP. The images follow a standard T2-weighted protocol in coronal and sagittal acquisitions. These two image volumes were fused in order to overcome large inter-slice spacing. The agreement between expert-delineated structures, used here as gold-standard, and our automatic segmentation was evaluated using Dice Similarity Index and surface-to-surface distances, obtaining a mean error of 0.68 mm in the annulus segmentation and 1.88 mm in the nucleus, which are the best results with respect to the image resolution in the current literature.

  15. Fully automated software for mitral annulus evaluation in chronic mitral regurgitation by 3-dimensional transesophageal echocardiography.

    Science.gov (United States)

    Aquila, Iolanda; Fernández-Golfín, Covadonga; Rincon, Luis Miguel; González, Ariana; García Martín, Ana; Hinojar, Rocio; Jimenez Nacher, Jose Julio; Indolfi, Ciro; Zamorano, Jose Luis

    2016-12-01

    Three-dimensional (3D) transesophageal echocardiography (TEE) is the gold standard for mitral valve (MV) anatomic and functional evaluation. Currently, dedicated MV analysis software has limitations for its use in clinical practice. Thus, we tested here a complete and reproducible evaluation of a new fully automatic software to characterize MV anatomy in different forms of mitral regurgitation (MR) by 3D TEE.Sixty patients were included: 45 with more than moderate MR (28 organic MR [OMR] and 17 functional MR [FMR]) and 15 controls. All patients underwent TEE. 3D MV images obtained using 3D zoom were imported into the new software for automatic analysis. Different MV parameters were obtained and compared. Anatomic and dynamic differences between FMR and OMR were detected. A significant increase in systolic (859.75 vs 801.83 vs 607.78 mm; P = 0.002) and diastolic (1040.60 vs. 1217.83 and 859.74 mm; P software analysis automatically calculates several significant parameters that provide a correct and complete assessment of anatomy and dynamic mitral annulus geometry and displacement in the 3D space. This analysis allows a better characterization of MR pathophysiology and could be useful in designing new devices for MR repair or replacement.

  16. Two dimensional analysis of low pressure flows in the annulus region between two concentric cylinders.

    Science.gov (United States)

    Al-Kouz, Wael; Alshare, Aiman; Alkhalidi, Ammar; Kiwan, Suhil

    2016-01-01

    A numerical simulation of the steady two-dimensional laminar natural convection heat transfer for the gaseous low-pressure flows in the annulus region between two concentric horizontal cylinders is carried out. This type of flow occurs in "evacuated" solar collectors and in the receivers of the solar parabolic trough collectors. A finite volume code is used to solve the coupled set of governing equations. Boussinesq approximation is utilized to model the buoyancy effect. A correlation for the thermal conductivity ratio (k r = k eff/k) in terms of Knudsen number and the modified Rayleigh number is proposed for Prandtl number (Pr = 0.701). It is found that as Knudsen number increases then the thermal conductivity ratio decreases for a given Rayleigh number. Also, it is shown that the thermal conductivity ratio k r increases as Rayleigh number increases. It appears that there is no consistent trend for varying the dimensionless gap spacing between the inner and the outer cylinder ([Formula: see text]) on the thermal conductivity ratio (k r) for the considered spacing range.

  17. Subcooled flow boiling heat transfer of ethanol aqueous solutions in vertical annulus space

    Directory of Open Access Journals (Sweden)

    Sarafraz M.M.

    2012-01-01

    Full Text Available The subcooled flow boiling heat-transfer characteristics of water and ethanol solutions in a vertical annulus have been investigated up to heat flux 132kW/m2. The variations in the effects of heat flux and fluid velocity, and concentration of ethanol on the observed heat-transfer coefficients over a range of ethanol concentrations implied an enhanced contribution of nucleate boiling heat transfer in flow boiling, where both forced convection and nucleate boiling heat transfer occurred. Increasing the ethanol concentration led to a significant deterioration in the observed heat-transfer coefficient because of a mixture effect, that resulted in a local rise in the saturation temperature of ethanol/water solution at the vapor-liquid interface. The reduction in the heat-transfer coefficient with increasing ethanol concentration is also attributed to changes in the fluid properties (for example, viscosity and heat capacity of tested solutions with different ethanol content. The experimental data were compared with some well-established existing correlations. Results of comparisons indicate existing correlations are unable to obtain the acceptable values. Therefore a modified correlation based on Gnielinski correlation has been proposed that predicts the heat transfer coefficient for ethanol/water solution with uncertainty about 8% that is the least in comparison to other well-known existing correlations.

  18. Radiation effects on bifurcation and dual solutions in transient natural convection in a horizontal annulus

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Kang; Yi, Hong-Liang, E-mail: yihongliang@hit.edu.cn; Tan, He-Ping, E-mail: tanheping@hit.edu.cn [School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2014-05-15

    Transitions and bifurcations of transient natural convection in a horizontal annulus with radiatively participating medium are numerically investigated using the coupled lattice Boltzmann and direct collocation meshless (LB-DCM) method. As a hybrid approach based on a common multi-scale Boltzmann-type model, the LB-DCM scheme is easy to implement and has an excellent flexibility in dealing with the irregular geometries. Separate particle distribution functions in the LBM are used to calculate the density field, the velocity field and the thermal field. In the radiatively participating medium, the contribution of thermal radiation to natural convection must be taken into account, and it is considered as a radiative term in the energy equation that is solved by the meshless method with moving least-squares (MLS) approximation. The occurrence of various instabilities and bifurcative phenomena is analyzed for different Rayleigh number Ra and Prandtl number Pr with and without radiation. Then, bifurcation diagrams and dual solutions are presented for relevant radiative parameters, such as convection-radiation parameter Rc and optical thickness τ. Numerical results show that the presence of volumetric radiation changes the static temperature gradient of the fluid, and generally results in an increase in the flow critical value. Besides, the existence and development of dual solutions of transient convection in the presence of radiation are greatly affected by radiative parameters. Finally, the advantage of LB-DCM combination is discussed, and the potential benefits of applying the LB-DCM method to multi-field coupling problems are demonstrated.

  19. Chaotic micromixer utilizing electro-osmosis and induced charge electro-osmosis in eccentric annulus

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Huicheng; Wong, Teck Neng, E-mail: mtnwong@ntu.edu.sg; Marcos [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Che, Zhizhao [State Key Laboratory of Engines, Tianjin University, Tianjin 300072 (China)

    2016-06-15

    Efficient mixing is of significant importance in numerous chemical and biomedical applications but difficult to realize rapidly in microgeometries due to the lack of turbulence. We propose to enhance mixing by introducing Lagrangian chaos through electro-osmosis (EO) or induced charge electro-osmosis (ICEO) in an eccentric annulus. The analysis reveals that the created Lagrangian chaos can achieve a homogeneous mixing much more rapidly than either the pure EO or the pure ICEO. Our systematic investigations on the key parameters, ranging from the eccentricity, the alternating time period, the number of flow patterns in one time period, to the specific flow patterns utilized for the Lagrangian chaos creation, present that the Lagrangian chaos is considerably robust. The system can obtain a good mixing effect with wide ranges of eccentricity, alternating time period, and specific flow patterns utilized for the Lagrangian chaos creation as long as the number of flow patterns in one time period is two. As the electric field increases, the time consumption for homogenous mixing is reduced more remarkably for the Lagrangian chaos of the ICEO than that of the EO.

  20. Effect of Yield Power Law Fluid Rheological Properties on Cuttings Transport in Eccentric Horizontal Narrow Annulus

    Directory of Open Access Journals (Sweden)

    Titus Ntow Ofei

    2016-01-01

    Full Text Available Narrow annular drilling such as casing-while-drilling technique is gaining popularity due to its ability to mitigate nonproductive time during oil and gas drilling operations. However, very little is known about the flow dynamics in narrow annular drilling. In this study, the Eulerian-Eulerian two-fluid model was used to examine the influence of Yield Power Law fluid rheological properties on cuttings transport in eccentric horizontal narrow annulus. The flow was assumed as fully developed, laminar, and transient state. The present simulation model was validated against experimental data, where a mean percent error of −1.2% was recorded. Results revealed an increase in the radial distribution of cuttings transport velocity in the wide annular region as the consistency index, K, and the flow behavior index, n, increase. Nonetheless, increasing the yield stress, τo, had insignificant effect on the cuttings transport velocity. Three-dimensional profiles showed how cuttings preferred to travel in less resistant flow area, whereas cuttings concentration builds up in the narrow annular region. Furthermore, annular frictional pressure losses also increased as K, n, and τo increased. This study serves as a guide to properly optimize drilling fluid rheological properties for efficient cuttings transport and equivalent circulating density (ECD management in narrow annular drilling.

  1. [Long-term results of conventional aortic valve replacement for small aortic annulus].

    Science.gov (United States)

    Miura, Y; Miyairi, T; Kitamura, T; Kigawa, I; Fukuda, S

    2006-04-01

    We studied cardiac function, clinical outcome and quality of life (QOL) long after aortic valve replacement for pure aortic stenosis. Forty-four patients in small group [St. Jude Medical (SJM) 17 HP, 19 A], and 69 patients in non-small group (19 HP, 21 A, 23 A) operated on from 1984 to 2004 were enrolled in this study. We assessed the clinical data, aortic pressure gradient, left ventricular mass index (LVMI), and ejection fraction (EF) by preoperative and postoperative echocardiography. Moreover to evaluate QOL after the operation, we performed SF-36 used for the evaluation of health and QOL worldwide. Mean follow-up is 7.1 +/- 4.8 years in small group, and 6.8 +/- 4.6 years in non-small group. There were 2 hospital deaths in small group, and 1 in non-small group. The actual survival rate at 10-year were 89.2% in small group, and 85.6% in non-small group. There was no significant difference in hospital mortality, LVMI, long-term survival rate, and the scores of SF-36 between the 2 groups. The use of small sized prosthetic valves in patients with small aortic annulus might be justified when there is no patient-prosthesis mismatch.

  2. Enlargement of the aortic annulus during aortic valve replacement: a review.

    Science.gov (United States)

    Bortolotti, Uberto; Celiento, Michele; Milano, Aldo D

    2014-01-01

    The main goal of aortic valve replacement (AVR) is to obtain relief from the fixed left ventricular (LV) obstruction by replacing the aortic valve with a prosthesis, either mechanical or biological, of adequate size. Most currently available prostheses provide satisfactory hemodynamic performance, but small-sized prostheses may be associated with high transvalvular gradients and suboptimal effective orifice area that result in prosthesis-patient mismatch (PPM), and thus are far from ideal for use in young, active patients. The avoidance of PPM is advisable as it has been repeatedly associated with increased mortality, decreased exercise tolerance and an impaired regression of LV hypertrophy after AVR for severe aortic stenosis. Enlargement of the aortic annulus (EAA) has proved to be a valuable method to prevent PPM in the presence of a diminutive aortic root. This review outlines the various techniques described for EAA, presenting technical details, long-term results and major procedure-related complications, and discussing the current role of EAA in patients requiring AVR.

  3. Experiments on transitions of baroclinic waves in a differentially heated rotating annulus

    Directory of Open Access Journals (Sweden)

    Th. von Larcher

    2005-01-01

    Full Text Available Experiments of baroclinic waves in a rotating, baroclinic annulus of fluid are presented for two gap widths. The apparatus is a differentially heated cylindrical gap, rotated around its vertical axis of symmetry, cooled from within, with a free surface, and filled with de-ionised water as working fluid. The surface flow was observed with visualisation technique while thermographic measurements gave a detailed understanding of the temperature distribution and its time-dependent behaviour. We focus in particular on transitions between different flow regimes. Using a wide gap, the first transition from axisymmetric flow to the regular wave regime was characterised by complex flows. The transition to irregular flows was smooth, where a coexistence of the large-scale jet-stream and small-scale vortices was observed. Furthermore, temperature measurements showed a repetitive separation of cold vortices from the inner wall. Experiments using a narrow gap showed no complex flows but strong hysteresis in the steady wave regime, with up to five different azimuthal wave modes as potential steady and stable solutions.

  4. Benchmarking in a rotating annulus: a comparative experimental and numerical study of baroclinic wave dynamics

    Directory of Open Access Journals (Sweden)

    Miklos Vincze

    2015-01-01

    Full Text Available The differentially heated rotating annulus is a widely studied tabletop-size laboratory model of the general mid-latitude atmospheric circulation. The two most relevant factors of cyclogenesis, namely rotation and meridional temperature gradient are quite well captured in this simple arrangement. The radial temperature difference in the cylindrical tank and its rotation rate can be set so that the isothermal surfaces in the bulk tilt, leading to the formation of baroclinic waves. The signatures of these waves at the free water surface have been analyzed via infrared thermography in a wide range of rotation rates (keeping the radial temperature difference constant and under different initial conditions. In parallel to the laboratory experiments, five groups of the MetStröm collaboration have conducted numerical simulations in the same parameter regime using different approaches and solvers, and applying different initial conditions and perturbations. The experimentally and numerically obtained baroclinic wave patterns have been evaluated and compared in terms of their dominant wave modes, spatio-temporal variance properties and drift rates. Thus certain “benchmarks” have been created that can later be used as test cases for atmospheric numerical model validation.

  5. Optical and electrical investigations into cathode ignition and diode closure

    Energy Technology Data Exchange (ETDEWEB)

    Coogan, J.J.; Rose, E.A.; Shurter, R.P.

    1991-01-01

    The temporal behavior of high-power diodes is closely related to the impedance collapse caused by the movement of the cathode and/or anode plasmas. This impedance collapse can be especially problematic when a constant power electron beam is required. This is the case for the very large area (square meters) diodes used to pump the amplifiers within the Aurora KrF laser system. The electron beam technology development program at Los Alamos utilizes the Electron Beam Test Facility (EGTF) to study diode physics in an attempt to better understand the basic phenomenology of ignition and closure. A combination of optical and electric diagnostics has been fielded on the Electron Beam Test Facility to study ignition and closure in large area electron beam diodes. A four-channel framing camera is used to observe the formation of microplasmas on the surface of the cathode and the subsequent movement of these plasmas toward the anode. Additionally, a perveance model is used to extract information about this plasma from voltage and current profiles. Results from the two diagnostics are compared. Closure velocity measurements are presented showing little dependence on applied magnetic field for both velvet and carbon felt emitters. We also report the first observation of the screening effect in large area cold cathode diodes. 13 refs., 11 figs.

  6. Optical and electrical investigations into cathode ignition and diode closure

    Science.gov (United States)

    Coogan, J. J.; Rose, E. A.; Shurter, R. P.

    The temporal behavior of high-power diodes is closely related to the impedance collapse caused by the movement of the cathode and/or anode plasmas. This impedance collapse can be especially problematic when a constant power electron beam is required. This is the case for the very large area (square meters) diodes used to pump the amplifiers within the Aurora KrF laser system. The electron beam technology development program at Los Alamos utilizes the Electron Beam Test Facility (EGTF) to study diode physics in an attempt to better understand the basic phenomenology of ignition and closure. A combination of optical and electric diagnostics has been fielded on the Electron Beam Test Facility to study ignition and closure in large area electron beam diodes. A four-channel framing camera is used to observe the formation of microplasmas on the surface of the cathode and the subsequent movement of these plasmas toward the anode. Additionally, a perveance model is used to extract information about this plasma from voltage and current profiles. Results from the two diagnostics are compared. Closure velocity measurements are presented showing little dependence on applied magnetic field for both velvet and carbon felt emitters. We also report the first observation of the screening effect in large area cold cathode diodes.

  7. Subsidence crack closure: rate, magnitude and sequence

    Energy Technology Data Exchange (ETDEWEB)

    De Graff, J.V.; Romesburg, H.C.

    1981-06-01

    Tension cracks are a major surface disturbance resulting from subsidence and differential settlement above underground coal mines. Recent engineering studies of subsidence indicate that cracks may close where tensile stresses causing the cracks are reduced or relaxed. This stress reduction occurs as mining in the area is completed. Crack closure was confirmed by a study in the Wasatch Plateau coal field of central Utah. Cracks occurred in both exposed bedrock and regolith in an area with maximum subsidence of 3 m. Mean closure rate was 0.3 cm per week with individual crack closure rates between 0.2 cm and 1.0 cm per week. The mean crack closure magnitude was 80% with closure magnitudes varying between 31% and 100%. Actual magnitude values ranged from 0.6 cm to 6.5 cm with a mean value of 3.8 cm. Statistical analysis compared width change status among cracks over time. It was found that: 1) a 41% probability existed that a crack would exhibit decreasing width per weekly measurement, 2) closure state sequences seem random over time, and 3) real differences in closure state sequence existed among different cracks. (6 refs.) (In English)

  8. Analytic closures for M1 neutrino transport

    Science.gov (United States)

    Murchikova, E. M.; Abdikamalov, E.; Urbatsch, T.

    2017-08-01

    Carefully accounting for neutrino transport is an essential component of many astrophysical studies. Solving the full transport equation is too expensive for most realistic applications, especially those involving multiple spatial dimensions. For such cases, resorting to approximations is often the only viable option for obtaining solutions. One such approximation, which recently became popular, is the M1 method. It utilizes the system of the lowest two moments of the transport equation and closes the system with an ad hoc closure relation. The accuracy of the M1 solution depends on the quality of the closure. Several closures have been proposed in the literature and have been used in various studies. We carry out an extensive study of these closures by comparing the results of M1 calculations with precise Monte Carlo calculations of the radiation field around spherically symmetric protoneutron star models. We find that no closure performs consistently better or worse than others in all cases. The level of accuracy that a given closure yields depends on the matter configuration, neutrino type and neutrino energy. Given this limitation, the maximum entropy closure by Minerbo on average yields relatively accurate results in the broadest set of cases considered in this work.

  9. Yucca Mountain Waste Package Closure System

    Energy Technology Data Exchange (ETDEWEB)

    shelton-davis; Colleen Shelton-Davis; Greg Housley

    2005-10-01

    The current disposal path for high-level waste is to place the material into secure waste packages that are inserted into a repository. The Idaho National Laboratory has been tasked with the development, design, and demonstration of the waste package closure system for the repository project. The closure system design includes welding three lids and a purge port cap, four methods of nondestructive examination, and evacuation and backfill of the waste package, all performed in a remote environment. A demonstration of the closure system will be performed with a full-scale waste package.

  10. Yucca Mountain Waste Package Closure System

    Energy Technology Data Exchange (ETDEWEB)

    Herschel Smartt; Arthur Watkins; David Pace; Rodney Bitsoi; Eric Larsen; Timothy McJunkin; Charles Tolle

    2006-04-01

    The current disposal path for high-level waste is to place the material into secure waste packages that are inserted into a repository. The Idaho National Laboratory has been tasked with the development, design, and demonstration of the waste package closure system for the repository project. The closure system design includes welding three lids and a purge port cap, four methods of nondestructive examination, and evacuation and backfill of the waste package, all performed in a remote environment. A demonstration of the closure system will be performed with a full-scale waste package.

  11. Systematization of a set of closure techniques.

    Science.gov (United States)

    Hausken, Kjell; Moxnes, John F

    2011-11-01

    Approximations in population dynamics are gaining popularity since stochastic models in large populations are time consuming even on a computer. Stochastic modeling causes an infinite set of ordinary differential equations for the moments. Closure models are useful since they recast this infinite set into a finite set of ordinary differential equations. This paper systematizes a set of closure approximations. We develop a system, which we call a power p closure of n moments, where 0≤p≤n. Keeling's (2000a,b) approximation with third order moments is shown to be an instantiation of this system which we call a power 3 closure of 3 moments. We present an epidemiological example and evaluate the system for third and fourth moments compared with Monte Carlo simulations.

  12. Entropy production and collisionless fluid closure

    Energy Technology Data Exchange (ETDEWEB)

    Sarazin, Y; Zarzoso, D; Garbet, X; Ghendrih, Ph; Grandgirard, V [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Dif-Pradalier, G, E-mail: yanick.sarazin@cea.f [Center for Astrophysics and Space Science, U.C.S.D., La Jolla, CA 92093 (United States)

    2009-11-15

    A novel method is proposed to construct collisionless fluid closures accounting for some kinetic properties. The idea consists in optimizing the agreement between the fluid and kinetic quasi-linear entropy production rates, so as to constrain the closure coefficients. This procedure is applied to the slab branch of the ion temperature gradient driven instability. Focusing on the kinetic regime characterized by slow waves, the closure proposed by Hammett and Perkins (Hammett and Perkins 1990 Phys. Rev. Lett. 64 3019) naturally emerges from the systematic identification of the kinetic and fluid entropy production rates. This closure is revealed to be extremely powerful well beyond the kinetic regime. Besides, it reconciles the fluid and kinetic linear stability diagrams in the two-dimensional space of the density and temperature gradient lengths. Such a method is systematic and generic. As such, it is applicable to other models and classes of instabilities.

  13. Entropy production and collisionless fluid closure

    Science.gov (United States)

    Sarazin, Y.; Dif-Pradalier, G.; Zarzoso, D.; Garbet, X.; Ghendrih, Ph; Grandgirard, V.

    2009-11-01

    A novel method is proposed to construct collisionless fluid closures accounting for some kinetic properties. The idea consists in optimizing the agreement between the fluid and kinetic quasi-linear entropy production rates, so as to constrain the closure coefficients. This procedure is applied to the slab branch of the ion temperature gradient driven instability. Focusing on the kinetic regime characterized by slow waves, the closure proposed by Hammett and Perkins (Hammett and Perkins 1990 Phys. Rev. Lett. 64 3019) naturally emerges from the systematic identification of the kinetic and fluid entropy production rates. This closure is revealed to be extremely powerful well beyond the kinetic regime. Besides, it reconciles the fluid and kinetic linear stability diagrams in the two-dimensional space of the density and temperature gradient lengths. Such a method is systematic and generic. As such, it is applicable to other models and classes of instabilities.

  14. Testing turbulent closure models with convection simulations

    CERN Document Server

    Snellman, J E; Mantere, M J; Rheinhardt, M; Dintrans, B

    2012-01-01

    Aims: To compare simple analytical closure models of turbulent Boussinesq convection for stellar applications with direct three-dimensional simulations both in homogeneous and inhomogeneous (bounded) setups. Methods: We use simple analytical closure models to compute the fluxes of angular momentum and heat as a function of rotation rate measured by the Taylor number. We also investigate cases with varying angles between the angular velocity and gravity vectors, corresponding to locating the computational domain at different latitudes ranging from the pole to the equator of the star. We perform three-dimensional numerical simulations in the same parameter regimes for comparison. The free parameters appearing in the closure models are calibrated by two fit methods using simulation data. Unique determination of the closure parameters is possible only in the non-rotating case and when the system is placed at the pole. In the other cases the fit procedures yield somewhat differing results. The quality of the closu...

  15. Cyanoacrylate for Intraoral Wound Closure: A Possibility?

    Directory of Open Access Journals (Sweden)

    Parimala Sagar

    2015-01-01

    Full Text Available Wound closure is a part of any surgical procedure and the objective of laceration repair or incision closure is to approximate the edges of a wound so that natural healing process may occur. Over the years new biomaterials have been discovered as an alternate to conventional suture materials. Cyanoacrylate bioadhesives are one among them. They carry the advantages of rapid application, patient comfort, resistance to infection, hemostatic properties, and no suture removal anxiety. Hence this study was undertaken to study the effect of long chain cyanoacrylate as an adhesive for intraoral wound closure and also to explore its hemostatic and antibacterial effects. Isoamyl-2-cyanoacrylate (AMCRYLATE was used as the adhesive in the study. In conclusion isoamyl cyanoacrylate can be used for intraoral wound closure, as an alternative to sutures for gluing the mucoperiosteum to bone, for example, after impaction removal, periapical surgeries, and cleft repair. Its hemostatic and antibacterial activity has to be further evaluated.

  16. Educing the emission mechanism of internal gravity waves in the differentially heat rotating annulus

    Science.gov (United States)

    Rolland, Joran; Hien, Steffen; Achatz, Ulrich; Borchert, Sebastian; Fruman, Mark

    2016-04-01

    Understanding the lifecycle of gravity waves is fundamental to a good comprehension of the dynamics of the atmosphere. In this lifecycle, the emission mechanisms may be the most elusive. Indeed, while the emission of gravity waves by orography or convection is well understood, the so-called spontaneous emission is still a quite open topic of investigation [1]. This type of emission usually occur very near jet-front systems in the troposphere. In this abstract, we announce our numerical study of the question. Model systems of the atmosphere which can be easily simulated or built in a laboratory have always been an important part of the study of atmospheric dynamics, alongside global simulations, in situ measurements and theory. In the case of the study of the spontaneous emission of gravity waves near jet-front systems, the differentially heated rotating annulus set up has been proposed and extensively used. It comprises of an annular tank containing water: the inner cylinder is kept at a cold temperature while the outer cylinder is kept at a warm temperature. The whole system is rotating. Provided the values of the control parameters (temperature, rotation rate, gap between the cylinders, height of water) are well chosen, the resulting flow mimics the troposphere at midlatitudes: it has a jet stream, and a baroclinic lifecycle develops on top of it. A very reasonable ratio of Brunt-Väisälä frequency over rotation rate of the system can be obtained, so as to be as close to the atmosphere as possible. Recent experiments as well as earlier numerical simulations in our research group have shown that gravity waves are indeed emitted in this set up, in particular near the jet front system of the baroclinic wave [2]. After a first experimental stage of characterising the emitted wavepacket, we focused our work on testing hypotheses on the gravity wave emission mechanism: we have tested and validated the hypothesis of spontaneous imbalance generated by the flow in

  17. Empirical singular vectors of baroclinic flows deduced from experimental data of a differentially heated rotating annulus

    Directory of Open Access Journals (Sweden)

    Michael Hoff

    2015-01-01

    Full Text Available Instability is related to exponentially growing eigenmodes. Interestingly, when finite time intervals are considered, growth rates of certain initial perturbations can exceed the growth rates of the most unstable modes. Moreover, even when all modes are damped, such particular initial perturbations can still grow during finite time intervals. The perturbations with the largest growth rates are called singular vectors (SVs or optimal perturbations. They not only play an important role in atmospheric ensemble predictions, but also for the theory of instability and turbulence. Starting point for a classical SV-analysis is a linear dynamical system with a known system matrix. In contrast to this traditional approach, measured data are used here to estimate the linear propagator. For this estimation, a method is applied that uses the covariances of the measured time series to find the principal oscillation patterns (POPs that are the empirically estimated linear eigenmodes of the system. By using the singular value decomposition (SVD, we can estimate the modes of maximal growth of the propagator which are thus the empirically estimated SVs. These modes can be understood as a superposition of POPs that form a complete but in general non-orthogonal basis. The data used, originate from a differentially heated rotating annulus laboratory experiment. This experiment is an analogue of the earth's atmosphere and is used to study the development of baroclinic waves in a well controlled and reproducible way without the need of numerical approximations. Baroclinic waves form the background for many studies on SV growth and it is thus straight forward to apply the technique of empirical SV estimation to these laboratory data. To test the method of SV estimation, we use a quasi-geostrophic barotropic model and compare the known SVs from that model with SVs estimated from a surrogate data set that was generated with the help of the exact model propagator and some

  18. A novel culture platform for fast proliferation of human annulus fibrosus cells.

    Science.gov (United States)

    Xiao, Li; Ding, Mengmeng; Saadoon, Osama; Vess, Eric; Fernandez, Andrew; Zhao, Ping; Jin, Li; Li, Xudong

    2017-02-01

    Tissue engineering provides a promising approach to treat degenerative disc disease, which usually requires a large quantity of seed cells. A simple and reliable in vitro culture system to expand seed cells in a timely fashion is necessary to implement the application clinically. Here, we sought to establish a cost-effective culture system for expanding human annulus fibrosus cells using extracellular matrix (ECM) proteins as culture substrates. Cells were cultured onto a plastic surface coated with various types of ECMs, including fibronectin, vitronectin, collagen type I, gelatin and cell-free matrix deposited by human nucleus pulposus cells. AF cell morphology, growth, adhesion and phenotype (anabolic and catabolic markers) were assessed by microscopy, real-time RT-PCR, western blotting, zymography, immunofluorescence staining and biochemical assays. Fibronectin, collagen and gelatin promoted cell proliferation and adhesion in a dose-dependent manner. Fibronectin elevated mRNA expression of proteoglycan and enhanced glycosaminoglycan production. Both collagen and gelatin increased protein expression of type II collagen. Consistent with increased cell adhesion, collagen and fibronectin promoted formation of focal adhesion complexes in the cell-matrix junction, suggesting enhanced binding of the actin network with both ECM substrates. On the other hand, fibronectin, collagen and gelatin decreased expression of matrix metalloproteinase-2 and matrix metalloproteinase-9 in media. Finally, a mixture of fibronectin (1.7 μg/mL) and collagen (1.3 μg/mL) was identified as the most promising in vitro culture substrate system in promoting proliferation and maintaining anabolic-catabolic balance. Our method provides a simple and cost-effective platform for tissue engineering applications in intervertebral disc research.

  19. The safe removal of frozen air from the annulus of an LH2 storage tank

    Science.gov (United States)

    Krenn, A.; Starr, S.; Youngquist, R.; Nurge, M.; Sass, J.; Fesmire, J.; Cariker, C.; Bhattacharya, A.

    2015-12-01

    Large Liquid Hydrogen (LH2) storage tanks are vital infrastructure for NASA. Eventually, air may leak into the evacuated and perlite filled annular region of these tanks. Although the vacuum level is monitored in this region, the extremely cold temperature causes all but the helium and neon constituents of air to freeze. A small, often unnoticeable pressure rise is the result. As the leak persists, the quantity of frozen air increases, as does the thermal conductivity of the insulation system. Consequently, a notable increase in commodity boil-off is often the first indicator of an air leak. Severe damage can result from normal draining of the tank. The warming air will sublimate which will cause a pressure rise in the annulus. When the pressure increases above the triple point, the frozen air will begin to melt and migrate downward. Collection of liquid air on the carbon steel outer shell may chill it below its ductility range, resulting in fracture. In order to avoid a structural failure, as described above, a method for the safe removal of frozen air is needed. A thermal model of the storage tank has been created using SINDA/FLUINT modelling software. Experimental work is progressing in an attempt to characterize the thermal conductivity of a perlite/frozen nitrogen mixture. A statistical mechanics model is being developed in parallel for comparison to experimental work. The thermal model will be updated using the experimental/statistical mechanical data, and used to simulate potential removal scenarios. This paper will address methodologies and analysis techniques for evaluation of two proposed air removal methods.

  20. Atmospheric-like rotating annulus experiment: gravity wave emission from baroclinic jets

    Science.gov (United States)

    Rodda, Costanza; Borcia, Ion; Harlander, Uwe

    2017-04-01

    Large-scale balanced flows can spontaneously radiate meso-scale inertia-gravity waves (IGWs) and are thus in fact unbalanced. While flow-dependent parameterizations for the radiation of IGWs from orographic and convective sources do exist, the situation is less developed for spontaneously emitted IGWs. Observations identify increased IGW activity in the vicinity of jet exit regions. A direct interpretation of those based on geostrophic adjustment might be tempting. However, directly applying this concept to the parameterization of spontaneous imbalance is difficult since the dynamics itself is continuously re-establishing an unbalanced flow which then sheds imbalances by GW radiation. Examining spontaneous IGW emission in the atmosphere and validating parameterization schemes confronts the scientist with particular challenges. Due to its extreme complexity, GW emission will always be embedded in the interaction of a multitude of interdependent processes, many of which are hardly detectable from analysis or campaign data. The benefits of repeated and more detailed measurements, while representing the only source of information about the real atmosphere, are limited by the non-repeatability of an atmospheric situation. The same event never occurs twice. This argues for complementary laboratory experiments, which can provide a more focused dialogue between experiment and theory. Indeed, life cycles are also examined in rotating- annulus laboratory experiments. Thus, these experiments might form a useful empirical benchmark for theoretical and modelling work that is also independent of any sort of subgrid model. In addition, the more direct correspondence between experimental and model data and the data reproducibility makes lab experiments a powerful testbed for parameterizations. Joint laboratory experiment and numerical simulation have been conducted. The comparison between the data obtained from the experiment and the numerical simulations shows a very good

  1. The Safe Removal of Frozen Air from the Annulus of an LH2 Storage Tank

    Science.gov (United States)

    Krenn, A.; Starr, S.; Youngquist, R.; Nurge, M.; Sass, J.; Fesmire, J.; Cariker, C.; Bhattacharya, A.

    2015-01-01

    Large Liquid Hydrogen (LH2) storage tanks are vital infrastructure for NASA. Eventually, air may leak into the evacuated and perlite filled annular region of these tanks. Although the vacuum level is monitored in this region, the extremely cold temperature causes all but the helium and neon constituents of air to freeze. A small, often unnoticeable pressure rise is the result. As the leak persists, the quantity of frozen air increases, as does the thermal conductivity of the insulation system. Consequently, a notable increase in commodity boil-off is often the first indicator of an air leak. Severe damage can result from normal draining of the tank. The warming air will sublimate which will cause a pressure rise in the annulus. When the pressure increases above the triple point, the frozen air will begin to melt and migrate downward. Collection of liquid air on the carbon steel outer shell may chill it below its ductility range, resulting in fracture. In order to avoid a structural failure, as described above, a method for the safe removal of frozen air is needed. A thermal model of the storage tank has been created using SINDA/FLUINT modeling software. Experimental work is progressing in an attempt to characterize the thermal conductivity of a perlite/frozen nitrogen mixture. A statistical mechanics model is being developed in parallel for comparison to experimental work. The thermal model will be updated using the experimental/statistical mechanical data, and used to simulate potential removal scenarios. This paper will address methodologies and analysis techniques for evaluation of two proposed air removal methods.

  2. Fully automated software for mitral annulus evaluation in chronic mitral regurgitation by 3-dimensional transesophageal echocardiography

    Science.gov (United States)

    Aquila, Iolanda; Fernández-Golfín, Covadonga; Rincon, Luis Miguel; González, Ariana; García Martín, Ana; Hinojar, Rocio; Jimenez Nacher, Jose Julio; Indolfi, Ciro; Zamorano, Jose Luis

    2016-01-01

    Abstract Three-dimensional (3D) transesophageal echocardiography (TEE) is the gold standard for mitral valve (MV) anatomic and functional evaluation. Currently, dedicated MV analysis software has limitations for its use in clinical practice. Thus, we tested here a complete and reproducible evaluation of a new fully automatic software to characterize MV anatomy in different forms of mitral regurgitation (MR) by 3D TEE. Sixty patients were included: 45 with more than moderate MR (28 organic MR [OMR] and 17 functional MR [FMR]) and 15 controls. All patients underwent TEE. 3D MV images obtained using 3D zoom were imported into the new software for automatic analysis. Different MV parameters were obtained and compared. Anatomic and dynamic differences between FMR and OMR were detected. A significant increase in systolic (859.75 vs 801.83 vs 607.78 mm2; P = 0.002) and diastolic (1040.60 vs. 1217.83 and 859.74 mm2; P < 0.001) annular sizes was observed in both OMR and FMR compared to that in controls. FMR had a reduced mitral annular contraction compared to degenerative cases of OMR and to controls (17.14% vs 32.78% and 29.89%; P = 0.007). Good reproducibility was demonstrated along with a short analysis time (mean 4.30 minutes). Annular characteristics and dynamics are abnormal in both FMR and OMR. Full 3D software analysis automatically calculates several significant parameters that provide a correct and complete assessment of anatomy and dynamic mitral annulus geometry and displacement in the 3D space. This analysis allows a better characterization of MR pathophysiology and could be useful in designing new devices for MR repair or replacement. PMID:27930514

  3. [Percutaneous closure of patent ductus arteriosus: results and costs compared to surgical closure].

    Science.gov (United States)

    Vieu, T; Beaurain, S; Angel, C; Leriche, H; Petit, J; Conso, J F; Planché, C; Losay, J

    1995-10-01

    The comparison of the clinical results and costs of the two methods of closure of patient ductus arteriosus was undertaken in two comparable groups of 40 patients treated in the same period in the same hospital. After transcatheter closure there was a 9% residual shunt rate at 3 years, the 2 patients with a residual continuous murmur being operated secondarily. The only complication was severe haemolysis which regressed after transcatheter ablation of the prosthesis. After surgical closure, there were no residual shunt. Some postoperative complications were observed in 20% of cases, usually benign (ventilatory problems, dysphonia or urinary infection), but occasionally more serious (peroperative lesion of the pulmonary artery). Morbidity, inherent to the technique of closure, was very different and much less in catheter closure. The average cost (daily cost x average length of hospital stay) was much less with transcatheter closure 38,558 francs versus 11,240 francs. On the other hand, the direct cost of transcatheter closure was greater than that of surgery: 32,798 francs versus 20,903 francs, the difference being related to the actual price of the prosthesis. The authors conclude that the 3 year results of transcatheter closure of patent ductus arterious make this technique a reasonable therapeutic alternative to surgery. From the safety point of view, the two techniques are comparable bu patient confort is greater with transcatheter closure for an increase in cost of the initial procedure which should decrease in relation to the types and prices of the prosthesis used.

  4. Primary closure for postoperative mediastinitis in children.

    Science.gov (United States)

    Ohye, Richard G; Maniker, Robert B; Graves, Holly L; Devaney, Eric J; Bove, Edward L

    2004-09-01

    Mediastinitis affects approximately 1% of children undergoing median sternotomy. Conventional therapy involves debridement followed by open wound care with delayed closure, days to weeks of closed suction or antimicrobial irrigation, and vacuum-assisted closure or muscle flap closure. We hypothesized that primary closure without prolonged suction or irrigation is an effective, less traumatic treatment for mediastinitis in children. From January 1986 to July 2002, 6705 procedures involving median sternotomy were performed at the C. S. Mott Children's Hospital, resulting in 57 cases of mediastinitis (0.85%). Cases were divided into 2 groups, with 42 cases treated with primary closure and 15 cases treated with delayed or muscle flap closure. The 42 cases of primary closure comprised the primary study group of this institutional review board-approved, retrospective analysis. Patient demographics, surgical variables, mediastinitis-related parameters, and outcomes were evaluated. One patient had recurrent mediastinitis for an overall infection eradication rate of 97% (40/41). Three patients (7%) required re-exploration for suspected ongoing infection. Of these re-explorations, 1 patient had evidence of continued mediastinitis. The remaining 2 patients with sepsis of unclear cause had no clinical or culture evidence of recurrent infection. One of these patients ultimately died of sepsis without active mediastinitis for a hospital survival of 97% (41/42). No significant differences could be detected between the treatment successes and failures in this small cohort of patients. Simple primary closure is an effective means to treat selected cases of postoperative mediastinitis in children. The results compare favorably with other more lengthy or debilitating treatments.

  5. Exceptional closure of UNIQA office at CERN

    CERN Multimedia

    HR Department

    2009-01-01

    The UNIQA office at CERN will be closed from Wednesday 18 February to Friday 20 February due to painting work. During this closure, the Headquarters of UNIQA in Geneva will remain at the disposal of the members. See details https://cern.ch/chis/UNIQA_Offices.asp The CERN office will re-open on Monday 23 February according to the normal schedule. We apologise for any inconvenience caused by this closure.

  6. 自体心包补片修补主动脉瓣环辅助主动脉瓣置换★%Autologous pericardium patch repairs the aortic annulus to assist aortic valve replacement

    Institute of Scientific and Technical Information of China (English)

    夏冰; 文冰; 许华山; 付国伟; 赵文增

    2013-01-01

    patients with calcific aortic stenosis complicated by annulus calcification were selected from the First Affiliated Hospital of Zhengzhou University during January 2009 and January 2012. Their clinical data were retrospectively analyzed. The effective orifice area index of aortic valve, maximum transvalvular pressure gradient, peak blood flow velocity and left ventricular ejection fraction were analyzed with statistical software before and after pericardium patch repaired aortic annulus assisted aortic valve replacement, and then the effect of autologous pericardium patch repaired aortic annulus to assist aortic valve replacement was analyzed. RESULTS AND CONLUSION: There was no intraoperative death during the pericardium patch repaired aortic annulus assisted aortic valve replacement. The intraoperative aortic clamping time was 52-88 (63.0±18.1) minutes, and the cardiopulmonary bypass time was 78-122 (102.6±25.1) minutes. One patient appeared acute renal failure after replacement, and cured after the bedside hemodialysis treatment. The rest patients had no serious complications. The length of hospital stay was 7-20 (13.6±5.5) days. The postoperative Doppler echocardiography showed the heart valve prosthesis was good, and no paravalvular leaks were found. The orifice area index of aortic valve, maximum transvalvular pressure gradient, peak blood flow velocity and left ventricular ejection fraction were significantly improved at 6 months after replacement, and the differences were significant when compared with those before replacement (P < 0.05). In patients with appropriate surgical indications, the autologous pericardium patch repaired aortic annulus assisted aortic valve replacement surgery can achieve satisfactory effects, and the operation is safe and simple, which is considered as a practicable technology.

  7. HWMA/RCRA Closure Plan for the TRA Fluorinel Dissolution Process Mockup and Gamma Facilities Waste System

    Energy Technology Data Exchange (ETDEWEB)

    K. Winterholler

    2007-01-31

    This Hazardous Waste Management Act/Resource Conservation and Recovery Act closure plan was developed for the Test Reactor Area Fluorinel Dissolution Process Mockup and Gamma Facilities Waste System, located in Building TRA-641 at the Reactor Technology Complex (RTC), Idaho National Laboratory Site, to meet a further milestone established under the Voluntary Consent Order SITE-TANK-005 Action Plan for Tank System TRA-009. The tank system to be closed is identified as VCO-SITE-TANK-005 Tank System TRA-009. This closure plan presents the closure performance standards and methods for achieving those standards.

  8. 主动脉瓣环扩大术在主动脉瓣置换术中的应用%Aortic annulus enlargement in aortic valve replacement for small aortic annulus

    Institute of Scientific and Technical Information of China (English)

    朱水波; 殷桂林; 胡健才; 张殿堂; 张晓明; 王荣平; 谭焱; 高旭辉; 刘勇

    2012-01-01

    Objective To summarize the experiences of aortic annulus enlargement in aortic valve replacement for small aortic annulus. Methods From Jan. 2000 to Sept,2010,18 cases of aortic valve disease with small aortic annulus received improved Manouguian procedure to enlarge the small aortic annulus before implanting appropriate mechanical aortic valve. Complicated heart lesion were treated surgically simultaneously. Results Complications in early stage including ventricular arrhythmia, severe low cardiac output syndrome and cardiac tamponade were cured. All cases were discharged without operative mortality. All cases were improved in cardiac function and ventricular wall mass. No death or other severe events occurred in follow - up. Conclusion Aortic annulus enlargement with improved Manougnian method is effective and safe in patients with small aortic annulus in order to implant appropriate mechanical aortic valve.%目的 总结主动脉瓣置换术中处理小主动脉瓣环的体会.方法 我院在2000年至2010年期间收治主动脉瓣环细小的主动脉瓣病变18例,均采取改良Manouguian方法扩大主动脉瓣环,再置入较合适的机械主动脉瓣.同期行二尖瓣置换6例,室间隔修补1例,三尖瓣成形5例.结果 17例有效开口面积指数(EOAI)均达到0.85cm2/m2以上,1例0.80cm2/m2.术后严重低心排综合征1例,室性心律失常3例,心脏压塞1例.18例痊愈出院,随访1~10年,术后6个月复查发现EOAI为0.80cm2/m2的患者主动脉跨瓣压差较高,室间隔及左室壁厚度恢复较慢,左室射血分数较低;而比值在0.85~1.0之间与大于1.0的患者相比,主动脉跨瓣压差、室间隔及左室壁厚度平均值稍高,但差异无统计学意义.2例术后6年因身高、体重增加EOAI分别下降到0.79、0.81cm2/m2,出现活动后心慌,心电图提示左室高电压,经扩管等药物治疗和一般处理,症状明显改善.结论 改良Manouguian方法扩大主动脉瓣环安全、有效,可置入

  9. Image-based mass-spring model of mitral valve closure for surgical planning

    Science.gov (United States)

    Hammer, Peter E.; Perrin, Douglas P.; del Nido, Pedro J.; Howe, Robert D.

    2008-03-01

    Surgical repair of the mitral valve is preferred in most cases over valve replacement, but replacement is often performed instead due to the technical difficulty of repair. A surgical planning system based on patient-specific medical images that allows surgeons to simulate and compare potential repair strategies could greatly improve surgical outcomes. In such a surgical simulator, the mathematical model of mechanics used to close the valve must be able to compute the closed state quickly and to handle the complex boundary conditions imposed by the chords that tether the valve leaflets. We have developed a system for generating a triangulated mesh of the valve surface from volumetric image data of the opened valve. We then compute the closed position of the mesh using a mass-spring model of dynamics. The triangulated mesh is produced by fitting an isosurface to the volumetric image data, and boundary conditions, including the valve annulus and chord endpoints, are identified in the image data using a graphical user interface. In the mass-spring model, triangle sides are treated as linear springs, and sides shared by two triangles are treated as bending springs. Chords are treated as nonlinear springs, and self-collisions are detected and resolved. Equations of motion are solved using implicit numerical integration. Accuracy was assessed by comparison of model results with an image of the same valve taken in the closed state. The model exhibited rapid valve closure and was able to reproduce important features of the closed valve.

  10. 105-DR Large Sodium Fire Facility closure activities evaluation report

    Energy Technology Data Exchange (ETDEWEB)

    Adler, J.G.

    1996-04-22

    This report evaluates the closure activities at the 105-DR Large Sodium Fire Facility. The closure activities discussed include: the closure activities for the structures, equipment, soil, and gravel scrubber; decontamination methods; materials made available for recycling or reuse; and waste management. The evaluation compares these activities to the regulatory requirements and closure plan requirements. The report concludes that the areas identified in the closure plan can be clean closed.

  11. NPAR- products, applications and closure

    Energy Technology Data Exchange (ETDEWEB)

    Vora, J.P.

    1995-04-01

    Almost a decade ago the Office of Nuclear Regulatory Research (RES) developed and implemented a comprehensive research program (NUREG-1144) widely known as NPAR or Nuclear Plant Aging Research. The NPAR program is a structured research program specifically oriented to understanding significant age-related degradation mechanisms and their long term effects on properties and performance of important components and systems and ways to mitigate detrimental effects of aging. It provided a road map and a phased approach to research that is applicable to any structure, system, or component of interest. This hardware-oriented engineering research program led the industry worldwide and communicated a need to understand and manage age-related degradation effects in selected but important structures and components. At the conclusion (1995) of the NPAR program, 22 electrical and mechanical components, 13 safety-related systems, and 10 special topics will have been studied and results summarized in 160 technical reports. This reference library of information listed and summarized in NUREG-1377, Rev. No. 4 provides a foundation upon which individual programs can be built for the specific needs of a utility, a regulator, or equipment manufacturers. During the life of the NPAR program, it has provided technical bases and support for license renewal, codes and standards, resolution of generic safety issues, information notices, regulatory guides and the standard Review Plan, as well as the Office of Nuclear Reactor Regulation and The NRC Regions. All ongoing NPAR activities will either be completed or terminated by the end of 1995. No new initiative will be undertaken. This paper summarizes NPAR products and accomplishments, application of the research results, and its status and closure.

  12. Accelerating cleanup: Paths to closure

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-06-01

    This report describes the status of Environmental Management`s (EM`s) cleanup program and a direction forward to complete achievement of the 2006 vision. Achieving the 2006 vision results in significant benefits related to accomplishing EM program objectives. As DOE sites accelerate cleanup activities, risks to public health, the environment, and worker safety and health are all reduced. Finding more efficient ways to conduct work can result in making compliance with applicable environmental requirements easier to achieve. Finally, as cleanup activities at sites are completed, the EM program can focus attention and resources on the small number of sites with more complex cleanup challenges. Chapter 1 describes the process by which this report has been developed and what it hopes to accomplish, its relationship to the EM decision-making process, and a general background of the EM mission and program. Chapter 2 describes how the site-by-site projections were constructed, and summarizes, for each of DOE`s 11 Operations/Field Offices, the projected costs and schedules for completing the cleanup mission. Chapter 3 presents summaries of the detailed cleanup projections from three of the 11 Operations/Field Offices: Rocky Flats (Colorado), Richland (Washington), and Savannah River (South Carolina). The remaining eight Operations/Field Office summaries are in Appendix E. Chapter 4 reviews the cost drivers, budgetary constraints, and performance enhancements underlying the detailed analysis of the 353 projects that comprise EM`s accelerated cleanup and closure effort. Chapter 5 describes a management system to support the EM program. Chapter 6 provides responses to the general comments received on the February draft of this document.

  13. Vendor Assessment for the Waste Package Closure System (Yucca Mountain Project)

    Energy Technology Data Exchange (ETDEWEB)

    Shelton-Davis, C.V.

    2003-09-26

    The Idaho National Engineering and Environmental Laboratory (INEEL) has been tasked with developing, designing, constructing, and operating a full-scale prototype of the work package closure system. As a precursor to developing the conceptual design, all commercially available equipment was assessed to identify any existing technology gaps. This report presents the results of that assessment for all major equipment.

  14. Vendor Assessment for the Waste Package Closure System (Yucca Mtn. Project)

    Energy Technology Data Exchange (ETDEWEB)

    Colleen Shelton-Davis

    2003-09-01

    The Idaho National Engineering and Environmental Laboratory (INEEL) has been tasked with developing, designing, constructing, and operating a full-scale prototype of the work package closure system. As a precursor to developing the conceptual design, all commercially available equipment was assessed to identify any existing technology gaps. This report presents the results of that assessment for all major equipment.

  15. Aortic annulus eccentricity before and after transcatheter aortic valve implantation: Comparison of balloon-expandable and self-expanding prostheses

    Energy Technology Data Exchange (ETDEWEB)

    Schuhbaeck, Annika, E-mail: annika.schuhbaeck@uk-erlangen.de [Department of Cardiology, University of Erlangen, Erlangen (Germany); Weingartner, Christina [Department of Cardiology, University of Gießen, Giessen (Germany); Arnold, Martin; Schmid, Jasmin; Pflederer, Tobias; Marwan, Mohamed [Department of Cardiology, University of Erlangen, Erlangen (Germany); Rixe, Johannes; Nef, Holger [Department of Cardiology, University of Gießen, Giessen (Germany); Schneider, Christian [Department of Radiology, University of Gießen, Giessen (Germany); Lell, Michael; Uder, Michael [Department of Radiology, University of Erlangen, Erlangen (Germany); Ensminger, Stephan [Department of Thoracic and Cardiovascular Surgery, Heart and Diabetes Center NRW, Ruhr-University Bochum, Bad Oeynhausen (Germany); Feyrer, Richard; Weyand, Michael [Department of Cardiothoracic Surgery, University of Erlangen, Erlangen (Germany); Achenbach, Stephan [Department of Cardiology, University of Erlangen, Erlangen (Germany)

    2015-07-15

    Highlights: • Post-implant geometry of catheter-based aortic valve prostheses is influenced by aortic valve calcification. • Balloon-expandable prostheses are more circular as compared to self-expanding prostheses. • The impact of post-implant geometry on valve function needs to be investigated. - Abstract: Introduction: The geometry of the aortic annulus and implanted transcatheter aortic valve prosthesis might influence valve function. We investigated the influence of valve type and aortic valve calcification on post-implant geometry of catheter-based aortic valve prostheses. Methods: Eighty consecutive patients with severe aortic valve stenosis (mean age 82 ± 6 years) underwent computed tomography before and after TAVI. Aortic annulus diameters were determined. Influence of prosthesis type and degree of aortic valve calcification on post-implant eccentricity were analysed. Results: Aortic annulus eccentricity was reduced in patients after TAVI (0.21 ± 0.06 vs. 0.08 ± 0.06, p < 0.0001). Post-TAVI eccentricity was significantly lower in 65 patients following implantation of a balloon-expandable prosthesis as compared to 15 patients who received a self-expanding prosthesis (0.06 ± 0.05 vs. 0.15 ± 0.07, p < 0.0001), even though the extent of aortic valve calcification was not different. After TAVI, patients with a higher calcium amount retained a significantly higher eccentricity compared to patients with lower amounts of calcium. Conclusions: Patients undergoing TAVI with a balloon-expandable prosthesis show a more circular shape of the implanted prosthesis as compared to patients with a self-expanding prosthesis. Eccentricity of the deployed prosthesis is affected by the extent of aortic valve calcification.

  16. [New technique of concomitant replacement of the aortic valve and the ascending aorta with enlargement of the aortic annulus for congenital bicuspid aortic valve].

    Science.gov (United States)

    Takahara, Shingo; Fukasawa, Manabu; Kawahara, Yu; Suzuki, Kotaro; Kobayashi, Yuriko

    2012-12-01

    Congenital bicuspid aortic valve (BAV) is one of the most common congenital heart diseases, with a high incidence of associated valvular lesions and aortic abnormalities including aortic stenosis( AS), aortic regurgitation, aortic dilatation, and aortic dissection. Patients with BAV and AS often have a small aortic annulus. We encountered a case of BAV in which a 51-year-old woman with severe AS having a small aortic annulus and a dilated ascending aorta required surgical intervention. We performed the surgery using new technique that involved concomitant replacement of the aortic valve and the ascending aorta with enlargement of the aortic annulus using a single uniquely-shaped graft to avoid prosthesis patient mismatch. We trimmed the proximal end of the straight graft in shape of 2 teardrops hanging on it to fit the cut annulus. It requires only a single suture line to replace the ascending aorta and enlarge the aortic annulus, which entails a decreased risk of bleeding during surgery. We believe that it could be applicable to many cases requiring concomitant surgery.

  17. 沿同心环面层流流动的气体中颗粒的传热沉积物的预测:发展中的流动和已充分发展的流动的比较%Prediction of Thermophoretic Deposition Efficiency of Particles in a Laminar Gas Flow along a Concentric Annulus: A Comparison of Developing and Fully Developed Flows

    Institute of Scientific and Technical Information of China (English)

    Samira Hashemi; Ataallah Soltani Goharrizi

    2009-01-01

    Thermophoresis is an important mechanism of micro-particle transport due to temperature gradients in the surrounding medium. It has numerous applications, especially in the field of aerosol technology. This study has numerically investigated the thermophoretic deposition efficiency of particles in a laminar gas flow in a concentric annulus using the critical trajectory method. The governing equations are the momentum and energy equations for the gas and the particle equations of motion. The effects of the annulus size, particle diameter, the ratio of inner to outer radius of tube and wall temperature on the deposition efficiency were studied for both developing and fully-developed flows. Simulation results suggest that thermophoretic deposition increases by increasing thermal gradient, deposition distance, and the ratio of inner to outer radius, but decreases with increasing particle size. It has been found that by taking into account the effect of developing flow at the entrance region, higher deposition efficiency was obtained, than fully developed flow.

  18. An eddy closure for potential vorticity

    Energy Technology Data Exchange (ETDEWEB)

    Ringler, Todd D [Los Alamos National Laboratory

    2009-01-01

    The Gent-McWilliams (GM) parameterization is extended to include a direct influence in the momentum equation. The extension is carried out in two stages; an analysis of the inviscid system is followed by an analysis of the viscous system. In the inviscid analysis the momentum equation is modified such that potential vorticity is conserved along particle trajectories following a transport velocity that includes the Bolus velocity in a manner exactly analogous to the continuity and tracer equations. In addition (and in contrast to traditional GM closures), the new formulation of the inviscid momentum equation results in a conservative exchange between potential and kinetic forms of energy. The inviscid form of the eddy closure conserves total energy to within an error proportional to the time derivative of the Bolus velocity. The hypothesis that the viscous term in the momentum equation should give rise to potential vorticity being diffused along isopycnals in a manner analogous to other tracers is examined in detail. While the form of the momentum closure that follows from a strict adherence to this hypothesis is not immediately interpretable within the constructs of traditional momentum closures, three approximations to this hypothesis results in a form of dissipation that is consistent with traditional Laplacian diffusion. The first two approximations are that relative vorticity, not potential vorticity, is diffused along isopyncals and that the flow is in approximate geostrophic balance. An additional approximation to the Jacobian term is required when the dissipation coefficient varies in space. More importantly, the critique of this hypothesis results in the conclusion that the viscosity parameter in the momentum equation should be identical to the tradition GM closure parameter {Kappa}. Overall, we deem the viscous form of the eddy closure for potential vorticity as a viable closure for use in ocean circulation models.

  19. NUMERICAL SIMULATION OF UNSTEADY FLOW FOR VISCO-ELASTIC FLUID IN AN ECCENTRIC ANNULUS WITH INNER ROD RECIPROCATION

    Institute of Scientific and Technical Information of China (English)

    HE Feng-yun; YANG Shu-ren

    2008-01-01

    The equation governing the unsteady flow of viscoelastic fluids in an eccentric annulus was derived by using the common conversion Maxwell fluid constitutive equation and then discretized by the control volume method. The velocity distribution of flow field was computed by using the ADI method. The influences of the pressure gradient, eccentricity, stroke length, and stroke frequency on the velocity and flow capacity in the flow field was analyzed. The foundation for further research of the eccentric wear problem of the pumping rod in polymer-flood well was laid.

  20. Influence factors on stress corrosion cracking of P110 tubing steel under CO2 injection well annulus environment

    Institute of Scientific and Technical Information of China (English)

    刘然克; 贾静焕; 杜翠薇; 李晓刚

    2016-01-01

    Stress corrosion cracking (SCC) behavior of P110 tubing steel in simulated CO2 injection well annulus environments was investigated through three-point bent tests, potentiodynamic polarization and EIS measurements. The results demonstrate that SCC of P110 tubing steel could occur in acidulous simulated environment, and the sensitivity of SCC increases with the decrease of pH, as well as increase of sulfide concentration and total environmental pressure. Both anodic dissolution and hydrogen embrittlement make contributions to the SCC. Adequate concentration of corrosion inhibitor can inhibit the occurrence of SCC on account of the inhibition of localized anodic dissolution and cathodic hydrogen evolution.

  1. Effects of Slotted Structures on Nonlinear Characteristics of Natural Convection in a Cylinder with an Internal Concentric Slotted Annulus

    CERN Document Server

    Shen, Chunyun; Zhang, Yuwen; Li, Zheng

    2016-01-01

    Natural convection in a cylinder with an internally slotted annulus was solved by SIMPLE algorithm, and the effects of different slotted structures on nonlinear characteristics of natural convection were investigated. The results show that the equivalent thermal conductivity Keq increases with Rayleigh number, and reaches the maximum in the vertical orientation. Nonlinear results were obtained by simulating the fluid flow at different conditions. With increasing Rayleigh number, heat transfer is intensified and the state of heat transfer changes from the steady to unsteady. We investigated different slotted structures effects on natural convection, and analyze the corresponding nonlinear characteristics.

  2. Field test of a post-closure radiation monitor

    Energy Technology Data Exchange (ETDEWEB)

    Reed, S.E. [Babcock & Wilcox, Alliance, OH (United States); Christy, C.E. [Department of Energy, Morgantown, WV (United States); Heath, R.E. [FERMCO, Cincinnati, OH (United States)

    1995-10-01

    The DOE is conducting remedial actions at many sites contaminated with radioactive materials. After closure of these sites, long-term subsurface monitoring is typically required by law. This monitoring is generally labor intensive and expensive using conventional sampling and analysis techniques. The U.S. Department of Energy`s Morgantown Energy Technology Center (METC) has contracted with Babcock and Wilcox to develop a Long-Term Post-Closure Radiation Monitoring System (LPRMS) to reduce these monitoring costs. The system designed in Phase I of this development program monitors gamma radiation using a subsurface cesium iodide scintillator coupled to above-ground detection electronics using optical waveguide. The radiation probe can be installed to depths up to 50 meters using cone penetrometer techniques, and requires no downhole electrical power. Multiplexing, data logging and analysis are performed at a central location. A prototype LPRMS probe was built, and B&W and FERMCO field tested this monitoring probe at the Fernald Environmental Management Project in the fall of 1994 with funding from the DOE`s Office of Technology Development (EM-50) through METC. The system was used measure soil and water with known uranium contamination levels, both in drums and in situ depths up to 3 meters. For comparison purposes measurements were also performed using a more conventional survey probe with a sodium iodide scintillator directly butt-coupled to detection electronics.

  3. Fibrin-genipin annulus fibrosus sealant as a delivery system for anti-TNFα drug

    Science.gov (United States)

    Likhitpanichkul, Morakot; Kim, Yesul; Torre, Olivia M; See, Eugene; Kazezian, Zepur; Pandit, Abhay; Hecht, Andrew C

    2015-01-01

    Background context Intervertebral discs (IVD) are attractive targets for local drug delivery because they are avascular structures with limited transport. Painful IVDs are in a chronic inflammatory state. While anti-inflammatories show poor performance in clinical trials their efficacy treating IVD cells suggests that sustained, local drug delivery directly to painful IVDs may be beneficial. Purpose To determine if genipin crosslinked fibrin (FibGen) with collagen type I hollow spheres (CHS) can serve as a drug delivery carrier for the anti-TNFα drug, infliximab. Infliximab was chosen as a model drug because of the known role of TNFα in increasing downstream production of several pro-inflammatory cytokines and pain mediators. FibGen was used as drug carrier because it is adhesive injectable, slowly degrading hydrogel with potential to seal annulus fibrosus (AF) defects. CHS allow simple and non-damaging drug loading and could act as a drug reservoir to improve sustained delivery. Study Design/Setting Biomaterials and human AF cell culture study to determine drug release kinetics and efficacy. Methods Infliximab was delivered at low and high concentrations using FibGen with and without CHS. Gels were analyzed for structure, drug release kinetics, and efficacy treating human AF cells following release. This work was funded by grants from the NIAMS/NIH (R01 AR057397), AO Foundation, and from the Icahn School of Medicine at Mount Sinai. Results Fibrin showed rapid infliximab drug release but degraded quickly. CHS alone showed a sustained release profile but the small spheres may not remain in a degenerated IVD with fissures. FibGen showed steady and low levels of infliximab release that was increased when loaded with higher drug concentrations. Infliximab was bound in CHS when delivered within FibGen and was only released following enzymatic degradation. The infliximab released over 20 days retained its bioactivity as confirmed by the sustained reduction of IL-1

  4. INTERLEUKIN-6 PROTECTS ANNULUS FIBROSUS CELL FROM APOPTOSIS INDUCED BY INTERLEUKIN-1 IN VITRO

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective To investigate the effect of interleukin-6 (IL-6) on the apoptosis of annulus fibrosus (AF) cell induced by interleukin-1 β (IL-1 β).Methods Cultured AF cells were divided into 6 groups and treated with no drug, 10 ng/mL IL-6, 10 ng/mL IL1β, 10 ng/mL IL-1β and Z-VAD-FMK (a caspase-9 inhibitor), 10 ng/mL IL-1β and 10 ng/mL IL-6, 10 ng/mL IL-1β and 100 ng/mL IL-6, respectively. After three days of culture, the apoptosis rate, the positive rates of caspase3, -8, and -9 of AF cells were detected with flow cytometry.Results The apoptosis rates of cells in group 1 to 6 were 2. 67%±1.08%, 2.71%±0.53%, 20.37%±1.57%, 11.34%±0.67%, 18.17%±0.74%, and 9.42%±1.08%, respectively. There was no significant difference between group 1 and 2, while the apoptosis rates of group 4, 5, and 6 were significantly lower than group 3 (P=0.001, P=0.172, and P=0.001, respectively). Positive rates of caspase-3 in group 5 (12.35%± 0.64%) and 6(9.26%±0.36%) were significantly lower than group 3 (17.14%±0.72%; P=0.001 and P<0.001, respectively). And positive rates of caspase-9 in group 5 (15.13%±1.45%) and 6 (10.17%±2.50%) were significantly lower than group 3 (19.4%±0.98%;P=0.014 and P=0.004, respectively). But there was not obvious change of caspase-8 activity after IL-6 was added.Conclusion IL-6 is capable of protecting AF cells from IL-1 β induced apoptosis in vitro. Mechanism of the protection is related with the inhibition of caspase-3 and -9 activities.

  5. Constant-flux discrete heating in a unit aspect-ratio annulus

    Science.gov (United States)

    Lopez, J. M.; Sankar, M.; Do, Younghae

    2012-10-01

    Natural convection in an annulus with a discrete heat source on the inner cylinder is studied numerically. The outer cylinder is isothermally cooled at a fixed low temperature, and the top wall, the bottom wall and unheated portions of the inner cylinder are thermally insulated. For low applied heat flux through the heater, as measured non-dimensionally by a Grashof number, Gr, the flow in the annular gap consists of a single-cell overturning meridional flow driven by the radial temperature gradient between the heater on the inner cylinder and the cold outer cylinder. In this regime, the flow is very weak and heat is transported primarily via conduction. The flow structure does not change until Gr ˜ 104, although the flow strength steadily increases with Gr. As the nonlinear convection terms become more important, the meridional circulation sweeps the isotherms from being almost vertical near the outer cylinder to almost horizontal near the bottom wall. By the end of the transition from the conduction-dominated regime (Gr vertical levels below that of the bottom of the heater, an essentially cold stagnant pool develops, with the heat flux through the outer cylinder dropping to zero. (ii) At vertical levels between the bottom and the top of the heater, most of the region in between the two cylinders is stably stratified with a relatively weak radial flow from the cold to the heated cylinder. The horizontal isotherms adjust to the temperatures on the cylinders in thin buoyancy boundary layers which drive fluid down the cold cylinder and up the heated cylinder segment. The boundary layer on the heater is about half as thick as that on the cold cylinder, but about twice as intense. (iii) The third region is above the heater top. The boundary layer flow from the heater continues upward where it meets the top endwall and bounces off of it. A wavy jet bounces on its way radially outward between the top insulated wall and the stably stratified region below. Flow

  6. A Judge Model of the Impact of Lane Closure Incident on Individual Vehicles on Freeways Based on RFID Technology and FOA-GRNN Method%基于RFID技术和FOA-GRNN理论的高速公路道路关闭交通事件对车辆影响的判断模型

    Institute of Scientific and Technical Information of China (English)

    史东亚; 陆键; 陆林军

    2012-01-01

    In order to compensate the disadvantage of AID based on traditional traffic statistics technology can detect the incident but can't identify whether the individual vehicle is affected by the incident, this article presents a judge model of impact of lane closure incident on individual vehicles on freeways based on RFID technology and FOA-GRNN method. This model uses GRNN to classify the traffic information collected by RFID, uses FOA to optimize the spread value of GRNN. With VISSIM simulation, results shows that the model has the feature of high DR, low FAR, and can quickly detect the vehicle influenced by incident to support traffic evanesce.%为弥补基于传统交通信息采集技术的高速公路交通事件检测算法仅能判断交通事件发生与否而无法判断车辆个体是否受到交通事件影响的不足,作者提出了一种基于RFID和FOA-GRNN的高速公路交通事件对车辆影响的判断模型.该模型使用RFID获取关键交通信息,利用广义回归神经网络对交通信息进行归类,应用果蝇优化算法获取广义回归神经网络的最佳平滑参数值.用VISSIM进行了仿真,对模型进行了验证,结果表明该判断模型具有检测率高、误警率低的特点,能迅速判断出受到交通事件影响的车辆,为交通疏导工作提供支持.

  7. Technology.

    Science.gov (United States)

    Online-Offline, 1998

    1998-01-01

    Focuses on technology, on advances in such areas as aeronautics, electronics, physics, the space sciences, as well as computers and the attendant progress in medicine, robotics, and artificial intelligence. Describes educational resources for elementary and middle school students, including Web sites, CD-ROMs and software, videotapes, books,…

  8. PHASE CLOSURE NULLING: THEORY AND PRACTICE

    Directory of Open Access Journals (Sweden)

    A. Chelli

    2009-01-01

    Full Text Available We provide a complete theory of the phase closure of a binary system in which a small, feeble, and unresolved companion acts as a perturbing parameter on the spatial frequency spectrum of a dominant, bright, resolved source. We demonstrate that the in uence of the companion can be measured with precision by measuring the phase closure of the system near the nulls of the primary visibility function. In these regions of phase closure nulling, frequency intervals always exist where the phase closure signature of the companion is larger than any systematic error and can thus be measured. We show that this technique allows retrieval of many astrophysically relevant properties of faint and close companions such as ux, position, and in favorable cases, spectrum. As a proof of concept, using the AMBER/VLTI instrument with 3 auxiliary telescopes of 1.8 m and only 15 minutes of on-sky integration, we detected the ve magnitudes fainter companion of HD 59717 at only 3.5 stellar radii distance from the primary. This is one of the highest contrast detected by interferometry between a companion and its parent star. We conclude by a rapid study of the potentialities of phase closure nulling observations with current interferometers and explore the requirements for a new type of dedicated instrument.

  9. Space Station evolution study oxygen loop closure

    Science.gov (United States)

    Wood, M. G.; Delong, D.

    1993-01-01

    In the current Space Station Freedom (SSF) Permanently Manned Configuration (PMC), physical scars for closing the oxygen loop by the addition of oxygen generation and carbon dioxide reduction hardware are not included. During station restructuring, the capability for oxygen loop closure was deferred to the B-modules. As such, the ability to close the oxygen loop in the U.S. Laboratory module (LAB A) and the Habitation A module (HAB A) is contingent on the presence of the B modules. To base oxygen loop closure of SSF on the funding of the B-modules may not be desirable. Therefore, this study was requested to evaluate the necessary hooks and scars in the A-modules to facilitate closure of the oxygen loop at or subsequent to PMC. The study defines the scars for oxygen loop closure with impacts to cost, weight and volume and assesses the effects of byproduct venting. In addition, the recommended scenarios for closure with regard to topology and packaging are presented.

  10. Closure Strategy Nevada Test Site Area 5 Radioactive Waste Management Site

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Management

    2007-03-01

    This paper presents an overview of the strategy for closure of part of the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada Test Site (NTS), which is about 65 miles northwest of Las Vegas, Nevada (Figure 1). The Area 5 RWMS is in the northern part of Frenchman Flat, approximately 14 miles north of Mercury. The Area 5 RWMS encompasses 732 acres subdivided into quadrants, and is bounded by a 1,000-foot (ft)-wide buffer zone. The northwest and southwest quadrants have not been developed. The northeast and southeast quadrants have been used for disposal of unclassified low-level radioactive waste (LLW) and indefinite storage of classified materials. This paper focuses on closure of the 38 waste disposal and classified material storage units within the southeast quadrant of the Area 5 RWMS, called the ''92-Acre Area''. The U.S Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO) is currently planning to close the 92-Acre Area by 2011. Closure planning for this site must take into account the regulatory requirements for a diversity of waste streams, disposal and storage configurations, disposal history, and site conditions. For ease of discussion, the 92-Acre Area has been subdivided into six closure units defined by waste type, location, and similarity in regulatory requirements. Each of the closure units contains one or more waste disposal units; waste disposal units are also called waste disposal cells. The paper provides a brief background of the Area 5 RWMS, identifies key closure issues for the 92-Acre Area, recommends actions to address the issues, and provides the National Security Technologies, LLC (NSTec), schedule for closure.

  11. Median sternotomy closure: review and update research

    Institute of Scientific and Technical Information of China (English)

    Hua Kun; Yang Xiubin

    2009-01-01

    Cardiac surgery is a very common operation nowadays all over the world. Median stemotomy is a routine procedure required for cardiac access during open heart surgery. The complications of this procedure after the cardiac surgery range from 0.7% to 1.5% of all cases, and bear a high mortality rate if they occur. Every individual surgeon must pay great attention on every detail during the sternal closure. This article shows the details as to conventional information and updated progress on median sternotomy closure. The update contents involve in biomechanics, number of wires twists, biomaterial and so on.According to our experience, we recommend four peristernal single/double steel wires for sternal closure as our optimal choice.

  12. Biological constraints do not entail cognitive closure.

    Science.gov (United States)

    Vlerick, Michael

    2014-12-01

    From the premise that our biology imposes cognitive constraints on our epistemic activities, a series of prominent authors--most notably Fodor, Chomsky and McGinn--have argued that we are cognitively closed to certain aspects and properties of the world. Cognitive constraints, they argue, entail cognitive closure. I argue that this is not the case. More precisely, I detect two unwarranted conflations at the core of arguments deriving closure from constraints. The first is a conflation of what I will refer to as 'representation' and 'object of representation'. The second confuses the cognitive scope of the assisted mind for that of the unassisted mind. Cognitive closure, I conclude, cannot be established from pointing out the (uncontroversial) existence of cognitive constraints.

  13. Hanford Patrol Academy demolition sites closure plan

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-30

    The Hanford Site is owned by the U.S. Government and operated by the U.S. Department of Energy, Richland Operations Office. Westinghouse Hanford Company is a major contractor to the U.S. Department of Energy, Richland Operations Office and serves as co-operator of the Hanford Patrol Academy Demolition Sites, the unit addressed in this paper. This document consists of a Hanford Facility Dangerous Waste Part A Permit Application, Form 3 (Revision 4), and a closure plan for the site. An explanation of the Part A Form 3 submitted with this closure plan is provided at the beginning of the Part A section. This Hanford Patrol Academy Demolition Sites Closure Plan submittal contains information current as of December 15, 1994.

  14. Adapting MARSSIM for FUSRAP site closure.

    Science.gov (United States)

    Johnson, Robert; Durham, L; Rieman, C

    2003-06-01

    The Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) provides a coherent, technically defensible process for establishing that exposed surfaces satisfy site cleanup requirements. Unfortunately, many sites have complications that challenge a direct application of MARSSIM. Example complications include Record of Decision (ROD) requirements that are not MARSSIM-friendly, the potential for subsurface contamination, and incomplete characterization information. These types of complications are typically the rule, rather than the exception, for sites undergoing radiologically-driven remediation and closure. One such site is the Formerly Utilized Sites Remedial Action Program (FUSRAP) Linde site in Tonawanda, New York. Cleanup of the site is currently underway. The Linde site presented a number of challenges to designing and implementing a closure strategy consistent with MARSSIM. This paper discusses some of the closure issues confronted by the U.S. Army Corps of Engineers Buffalo District at the Linde site and describes how MARSSIM protocols were adapted to address these issues.

  15. Simultaneous effects of single wall carbon nanotube and effective variable viscosity for peristaltic flow through annulus having permeable walls

    Science.gov (United States)

    Shahzadi, Iqra; Nadeem, S.; Rabiei, Faranak

    The current article deals with the combine effects of single wall carbon nanotubes and effective viscosity for the peristaltic flow of nanofluid through annulus. The nature of the walls is assumed to be permeable. The present theoretical model can be considered as mathematical representation to the motion of conductive physiological fluids in the existence of the endoscope tube which has many biomedical applications such as drug delivery system. The outer tube has a wave of sinusoidal nature that is travelling along its walls while the inner tube is rigid and uniform. Lubrication approach is used for the considered analysis. An empirical relation for the effective variable viscosity of nanofluid is proposed here interestingly. The viscosity of nanofluid is the function of radial distance and the concentration of nanoparticles. Exact solution for the resulting system of equations is displayed for various quantities of interest. The outcomes show that the maximum velocity of SWCNT-blood nanofluid enhances for larger values of viscosity parameter. The pressure gradient in the more extensive part of the annulus is likewise found to increase as a function of variable viscosity parameter. The size of the trapped bolus is also influenced by variable viscosity parameter. The present examination also revealed that the carbon nanotubes have many applications related to biomedicine.

  16. Characterization of mechanics and cytocompatibility of fibrin-genipin annulus fibrosus sealant with the addition of cell adhesion molecules.

    Science.gov (United States)

    Guterl, Clare C; Torre, Olivia M; Purmessur, Devina; Dave, Khyati; Likhitpanichkul, Morakot; Hecht, Andrew C; Nicoll, Steven B; Iatridis, James C

    2014-09-01

    There is an unmet clinical need for a biomaterial sealant capable of repairing small annulus fibrosus (AF) defects. Causes of these defects include painful intervertebral disc herniations, microdiscectomy procedures, morbidity associated with needle puncture injury from discography, and future nucleus replacement procedures. This study describes the enhancements of a fibrin gel through genipin crosslinking (FibGen) and the addition of the cell adhesion molecules (CAMs), fibronectin and collagen. The gel's performance as a potential AF sealant is assessed using a series of in vitro tests. FibGen gels with CAMs had equivalent adhesive strength, gene expression, cytomorphology, and cell proliferation as fibrin alone. However, FibGen gels had enhanced material behaviors that were tunable to higher shear stiffness values and approximated human annulus tissue as compared with fibrin alone, were more dimensionally stable, and had a slower in vitro degradation rate. Cytomorphology of human AF cells cultured on FibGen gels exhibited increased elongation compared with fibrin alone, and the addition of CAMs to FibGen did not significantly affect elongation. This FibGen gel offers the promise of being used as a sealant material to repair small AF defects or to be used in combination with other biomaterials as an adhesive for larger defects.

  17. 2401-W Waste storage building closure plan

    Energy Technology Data Exchange (ETDEWEB)

    LUKE, S.M.

    1999-07-15

    This plan describes the performance standards met and closure activities conducted to achieve clean closure of the 2401-W Waste Storage Building (2401-W) (Figure I). In August 1998, after the last waste container was removed from 2401-W, the U.S. Department of Energy, Richland Operations Office (DOE-RL) notified Washington State Department of Ecology (Ecology) in writing that the 2401-W would no longer receive waste and would be closed as a Resource Conservation and Recovery Act (RCRA) of 1976 treatment, storage, and/or disposal (TSD) unit (98-EAP-475). Pursuant to this notification, closure activities were conducted, as described in this plan, in accordance with Washington Administrative Code (WAC) 173-303-610 and completed on February 9, 1999. Ecology witnessed the closure activities. Consistent with clean closure, no postclosure activities will be necessary. Because 2401-W is a portion of the Central Waste Complex (CWC), these closure activities become the basis for removing this building from the CWC TSD unit boundary. The 2401-W is a pre-engineered steel building with a sealed concrete floor and a 15.2-centimeter concrete curb around the perimeter of the floor. This building operated from April 1988 until August 1998 storing non-liquid containerized mixed waste. All waste storage occurred indoors. No potential existed for 2401-W operations to have impacted soil. A review of operating records and interviews with cognizant operations personnel indicated that no waste spills occurred in this building (Appendix A). After all waste containers were removed, a radiation survey of the 2401-W floor for radiological release of the building was performed December 17, 1998, which identified no radiological contamination (Appendix B).

  18. PRESSURE DISTRIBUTION ON THE WALL OF THE INNER CYLINDER RECIPROCATING AXIALLY TO THE UNSTEADY FLOW OF VISCOELASTIC FLUID IN ECCENTRIC ANNULUS

    Institute of Scientific and Technical Information of China (English)

    WANG Yan; CUI Hai-qing; YANG Yuan-jian; GUO Jun-hui; LI Nan

    2006-01-01

    In this article, the governing equations for the unsteady flow of viscoelastic fluid in the eccentric annulus with the inner cylinder reciprocating axially and the expression of the pressure distribution on the wall of the inner cylinder of the annulus are established and derived, respectively, under the bipolar coordinate system.The equations and the expression are solved and calculated numerically using the finite difference method, respectively.The curves of the pressure distribution on the wall of the inner cylinder of the aqueous solution of Hydrolyzed Polyacrylamide (HPAM) are plotted and the influences of annular eccentricity, stroke, and stroke frequency on the pressure distribution are analyzed.

  19. Histological observation of a gelatin sponge transplant loaded with bone marrow-derived mesenchymal stem cells combined with platelet-rich plasma in repairing an annulus defect

    Science.gov (United States)

    Xu, Xiang; Hu, Jianzhong; Lu, Hongbin

    2017-01-01

    Objective To research the histological characteristics of a gelatin sponge transplant loaded with goat BMSCs (bone marrow-derived mesenchymal stem cells) combined with PRP (platelet-rich plasma) in repairing an annulus defect. Method BMSCs were separated from the iliac crest of goats, sub-cultured and identified after the third generation. Then, PRP was obtained using blood from the jugular vein of goats via two degrees of centrifugation. In the animal experiments, the goats were divided into the following three groups: a sham group, an injury group and a therapeutic group. In the sham group, we decompressed the lamina and exposed the annulus fibrosus. In the injury group, we exposed the annulus fibrosus after decompression of the lamina and created a 1 × 1 cm defect in the annulus using surgical instruments. In the therapeutic group, after decompression of the lamina, we exposed the annulus, created a 1 × 1 cm defect using surgical instruments, and placed a gelatin sponge combined with BMSCs and PRP into the defect for a combined method of repair. Three, six and twelve weeks after the surgery, the previously damaged or undamaged annulus tissue was removed from the three groups. Then, the above tissue was assayed using HE (hematoxylin-eosin) staining, Masson trichrome staining, AB-PAS (Alcian blue-periodic acid Schiff) staining, and type II collagen staining and observed by microscopy. Results From the HE staining, we observed that the number of repair cells gradually increased. Compared to the injury group, the cell density and gross morphology of cells in the therapeutic group were closer to those of the sham group. As observed by Masson trichrome gelatin staining, many of the fibroblast cells or tissues were under repair, and as time progressed, the number of fibroblast cells and amount of tissue gradually increased. The results of the AB-PAS staining suggest that chondrocytes participated in the repair of the annulus. The level of type II collagen gradually

  20. Final Clean Closure Report Site 300 Surface Impoundments Closure Lawrence Livermore National Laboratory Livermore, California

    Energy Technology Data Exchange (ETDEWEB)

    Haskell, K

    2006-02-14

    Lawrence Livermore National Laboratory operated two Class II surface impoundments that stored wastewater that was discharged from a number of buildings located on the Site 300 Facility (Site 300). The wastewater was the by-product of explosives processing. Reduction in the volume of water discharged from these buildings over the past several years significantly reduced the wastewater storage needs. In addition, the impoundments were constructed in 1984, and the high-density polyethylene (HDPE) geomembrane liners were nearing the end of their service life. The purpose of this project was to clean close the surface impoundments and provide new wastewater storage using above ground storage tanks at six locations. The tanks were installed and put into service prior to closure of the impoundments. This Clean Closure Report (Closure Report) complies with State Water Resources Control Board (SWRCB) Section 21400 of the California Code of Regulations Title 27 (27 CCR section 21400). As required by these regulations and guidance, this Closure Report provides the following information: (1) a brief site description; (2) the regulatory requirements relevant to clean closure of the impoundments; (3) the closure procedures; and (4) the findings and documentation of clean closure.

  1. Closure properties of Watson-Crick grammars

    Science.gov (United States)

    Zulkufli, Nurul Liyana binti Mohamad; Turaev, Sherzod; Tamrin, Mohd Izzuddin Mohd; Azeddine, Messikh

    2015-12-01

    In this paper, we define Watson-Crick context-free grammars, as an extension of Watson-Crick regular grammars and Watson-Crick linear grammars with context-free grammar rules. We show the relation of Watson-Crick (regular and linear) grammars to the sticker systems, and study some of the important closure properties of the Watson-Crick grammars. We establish that the Watson-Crick regular grammars are closed under almost all of the main closure operations, while the differences between other Watson-Crick grammars with their corresponding Chomsky grammars depend on the computational power of the Watson-Crick grammars which still need to be studied.

  2. The effect of plant closure on crime

    OpenAIRE

    Rege, Mari; Skarðhamar, Torbjørn; Telle, Kjetil; Votruba, Mark

    2009-01-01

    We estimate the effect of exposure to plant closure on crime using an individual-level panel data set containing criminal charges for all unmarried and employed Norwegian men below the age of 40. Men originally employed in plants that subsequently closed are 14 percent more likely to be charged of a crime than comparable men in stable plants. There is no difference in charge rates prior to closure, supporting a causal interpretation of our result. Within crime categories, we find no effect of...

  3. Straight line closure of congenital macrostomia

    Directory of Open Access Journals (Sweden)

    Schwarz Richard

    2004-01-01

    Full Text Available The results of patients operated on by Nepal Cleft Lip and Palate Association (NECLAPA surgeons for congenital macrostomia were prospectively studied between January 2000 and December 2002. There were four males and three females with a median age of 10 years. Three had an associated branchial arch syndrome. In all patients an overlapping repair of orbicularis oris was done. Six patients had a straight line closure with excellent cosmetic results and one a Z-plasty with a more obvious scar. All had a normal appearing commissure. Overlapping orbicularis repair with straight line skin closure for this rare congenital anomaly is recommended.

  4. Technology

    Directory of Open Access Journals (Sweden)

    Xu Jing

    2016-01-01

    Full Text Available The traditional answer card reading method using OMR (Optical Mark Reader, most commonly, OMR special card special use, less versatile, high cost, aiming at the existing problems proposed a method based on pattern recognition of the answer card identification method. Using the method based on Line Segment Detector to detect the tilt of the image, the existence of tilt image rotation correction, and eventually achieve positioning and detection of answers to the answer sheet .Pattern recognition technology for automatic reading, high accuracy, detect faster

  5. 78 FR 20625 - Extension of Hearing Record Closure Date

    Science.gov (United States)

    2013-04-05

    ... From the Federal Register Online via the Government Publishing Office DEFENSE NUCLEAR FACILITIES SAFETY BOARD Extension of Hearing Record Closure Date AGENCY: Defense Nuclear Facilities Safety Board. ACTION: Extension of hearing record closure date. SUMMARY: The Defense Nuclear Facilities Safety...

  6. 77 FR 65871 - Extension of Hearing Record Closure Date

    Science.gov (United States)

    2012-10-31

    ... From the Federal Register Online via the Government Publishing Office DEFENSE NUCLEAR FACILITIES SAFETY BOARD Extension of Hearing Record Closure Date AGENCY: Defense Nuclear Facilities Safety Board. ACTION: Extension of hearing record closure date. SUMMARY: The Defense Nuclear Facilities Safety...

  7. Chemical master equation closure for computer-aided synthetic biology.

    Science.gov (United States)

    Smadbeck, Patrick; Kaznessis, Yiannis N

    2015-01-01

    With inexpensive DNA synthesis technologies, we can now construct biological systems by quickly piecing together DNA sequences. Synthetic biology is the promising discipline that focuses on the construction of these new biological systems. Synthetic biology is an engineering discipline, and as such, it can benefit from mathematical modeling. This chapter focuses on mathematical models of biological systems. These models take the form of chemical reaction networks. The importance of stochasticity is discussed and methods to simulate stochastic reaction networks are reviewed. A closure scheme solution is also presented for the master equation of chemical reaction networks. The master equation is a complete model of randomly evolving molecular populations. Because of its ambitious character, the master equation remained unsolved for all but the simplest of molecular interaction networks for over 70 years. With the first complete solution of chemical master equations, a wide range of experimental observations of biomolecular interactions may be mathematically conceptualized. We anticipate that models based on the closure scheme described herein may assist in rationally designing synthetic biological systems.

  8. Soil Vapor Extraction System Optimization, Transition, and Closure Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Truex, Michael J.; Becker, Dave; Simon, Michelle A.; Oostrom, Martinus; Rice, Amy K.; Johnson, Christian D.

    2013-02-08

    Soil vapor extraction (SVE) is a prevalent remediation approach for volatile contaminants in the vadose zone. A diminishing rate of contaminant extraction over time is typically observed due to 1) diminishing contaminant mass, and/or 2) slow rates of removal for contamination in low-permeability zones. After a SVE system begins to show indications of diminishing contaminant removal rate, SVE performance needs to be evaluated to determine whether the system should be optimized, terminated, or transitioned to another technology to replace or augment SVE. This guidance specifically addresses the elements of this type of performance assessment. While not specifically presented, the approach and analyses in this guidance could also be applied at the onset of remediation selection for a site as a way to evaluate current or future impacts to groundwater from vadose zone contamination. The guidance presented here builds from existing guidance for SVE design, operation, optimization, and closure from the U.S. Environmental Protection Agency, U.S. Army Corps of Engineers, and the Air Force Center for Engineering and the Environment. The purpose of the material herein is to clarify and focus on the specific actions and decisions related to SVE optimization, transition, and/or closure.

  9. 33 CFR 154.520 - Closure devices.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Closure devices. 154.520 Section 154.520 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... devices. (a) Except as provided in paragraph (b) of this section, each facility to which this part...

  10. Rural Primary School Closures in England.

    Science.gov (United States)

    Whitfield, Richard C.

    A three-phase interdisciplinary effort between educators and environmental planners is focusing on the social effects of rural primary school reorganization now occuring in England as a result of a declining birth rate and the resulting need for school closure. A questionnaire mailed nationally to rural Local Education Authorities, cross-community…

  11. The Story of a Charter School Closure.

    Science.gov (United States)

    Flynn, Susan L.; Arguelles, Lourdes

    2001-01-01

    The story of a charter school closure is told from the perspectives of students, parents, teachers, and community members, who felt that the sponsoring district revoked the charter for political reasons despite broad local support. The experience underscores the necessity of publicly subjecting the relationship of the public school system and the…

  12. Parallel hierarchical evaluation of transitive closure queries

    NARCIS (Netherlands)

    Houtsma, M.A.W.; Cacace, F.; Ceri, S.

    1991-01-01

    Presents a new approach to parallel computation of transitive closure queries using a semantic data fragmentation. Tuples of a large base relation denote edges in a graph, which models a transportation network. A fragmentation algorithm is proposed which produces a partitioning of the base relation

  13. End-of-year closure - Mail Office

    CERN Multimedia

    GS Department

    2010-01-01

    On the occasion of the annual closure of CERN, there will be no mail distributed on Tuesday 21 December 2010, but mail will be collected in the morning. Nevertheless, it will be possible for you to bring your mail for the departure until 12:00 at building 555-R-002. Mail Office

  14. The Triangle Closure is a Polyhedron

    CERN Document Server

    Basu, Amitabh; Köppe, Matthias

    2011-01-01

    Recently, cutting planes derived from maximal lattice-free convex sets have been studied intensively by the integer programming community. An important question in this research area has been to decide whether the closures associated with certain families of lattice-free sets are polyhedra. For a long time, the only result known was the celebrated theorem of Cook, Kannan and Schrijver who showed that the split closure is a polyhedron. Although some fairly general results were obtained by Andersen, Louveaux and Weismantel [An analysis of mixed integer linear sets based on lattice point free convex sets, Math. Oper. Res. 35, (2010) pp. 233--256], some basic questions have remained unresolved. For example, maximal lattice-free triangles are the natural family to study beyond the family of splits and it has been a standing open problem to decide whether the triangle closure is a polyhedron. In this paper, we resolve this by showing that the triangle closure is indeed a polyhedron, and its number of facets can be ...

  15. 300 Area Process Trenches Closure Plan

    Energy Technology Data Exchange (ETDEWEB)

    Luke, S.N.

    1994-08-15

    Since 1987, Westinghouse Hanford Company has been a major contractor to the US Department of Energy, Richland Operations Office and has served as co-operator of the 300 Area Process Trenches, the waste management unit addressed in this closure plan. For the purposes of the Resource Conservation and Recovery Act, Westinghouse Hanford Company is identified as ``co-operator.`` The 300 Area Process Trenches Closure Plan (Revision 0) consists of a Resource Conservation and Recovery Act Part A Dangerous Waste Permit Application, Form 3 and a Resource Conservation and Recovery Act Closure Plan. An explanation of the Part A Permit Application, Form 3 submitted with this document is provided at the beginning of the Part A Section. The closure plan consists of nine chapters and six appendices. The 300 Area Process Trenches received dangerous waste discharges from research and development laboratories in the 300 Area and from fuels fabrication processes. This waste consisted of state-only toxic (WT02), corrosive (D002), chromium (D007), spent halogenated solvents (F001, F002, and F003), and spent nonhalogented solvent (F005). Accurate records are unavailable concerning the amount of dangerous waste discharged to the trenches. The estimated annual quantity of waste (item IV.B) reflects the total quantity of both regulated and nonregulated waste water that was discharged to the unit.

  16. Opening up closure. Semiotics across scales

    Science.gov (United States)

    Lemke

    2000-01-01

    The dynamic emergence of new levels of organization in complex systems is related to the semiotic reorganization of discrete/continuous variety at the level below as continuous/discrete meaning for the level above. In this view both the semiotic and the dynamic closure of system levels is reopened to allow the development and evolution of greater complexity.

  17. Individual Consequences of Plant Closures and Cutbacks

    DEFF Research Database (Denmark)

    Andersen, Steen

    1991-01-01

    This thesis describes the segment of unemployment which has its origin in major closures and cutbacks. The argument for this is to make it possible to describe and to analyse a flow into and a flow out of a population of unemployed. Given a major dismissal the following questions are to be answer...

  18. Primary closure of equine laryngotomy incisions

    DEFF Research Database (Denmark)

    Lindegaard, C.; Karlsson, L.; Ekstrøm, C. T.;

    2016-01-01

    The objective was to report healing characteristics and complications after primary closure of equine laryngotomies and analyse factors potentially associated with complications. This retrospective case series of the medical records of horses (n = 180) undergoing laryngoplasty and laryngotomy inc...

  19. Parallel hierarchical evaluation of transitive closure queries

    NARCIS (Netherlands)

    Houtsma, M.A.W.; Houtsma, M.A.W.; Cacace, F.; Ceri, S.

    1991-01-01

    Presents a new approach to parallel computation of transitive closure queries using a semantic data fragmentation. Tuples of a large base relation denote edges in a graph, which models a transportation network. A fragmentation algorithm is proposed which produces a partitioning of the base relation

  20. 50 CFR 648.141 - Closure.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Closure. 648.141 Section 648.141 Wildlife... inaction of one or more states will cause the applicable target exploitation rate specified in § 648.140(a... state has been remedied by that state without causing the applicable specified target exploitation...

  1. Synthesis of azaphenanthridines via anionic ring closure

    DEFF Research Database (Denmark)

    Hansen, Henriette Møller; Lysén, M.; Begtrup, M.;

    2005-01-01

    A new and convergent synthesis of azaphenanthridines via an anionic ring closure is reported. Ortho-lithiation/in situ borylation of cyanopyridines produces the corresponding cyanopyridylboronic esters, which undergo a Suzuki-Miyaura cross-coupling to give the key intermediates. Addition of lithium...

  2. 50 CFR 635.28 - Closures.

    Science.gov (United States)

    2010-10-01

    ... for the shark species or complexes specified in § 635.27(b)(1) will remain open. (2) When NMFS..., provided the harvesting vessel does no fishing after the closure in the Atlantic Ocean north of 5 N. lat., and reports positions with a vessel monitoring system, as specified in § 635.69. Additionally,...

  3. Technical Review of Retrieval and Closure Plans for the INEEL INTEC Tank Farm Facility

    Energy Technology Data Exchange (ETDEWEB)

    Bamberger, Judith A.; Burks, Barry L.; Quigley, Keith D.; Butterworth, S. W.; Falter, Diedre D.

    2001-09-28

    The purpose of this report is to document the conclusions of a technical review of retrieval and closure plans for the Idaho National Energy and Environmental Laboratory (INEEL) Idaho Nuclear Technology and Engineering Center (INTEC) Tank Farm Facility. In addition to reviewing retrieval and closure plans for these tanks, the review process served as an information exchange mechanism so that staff in the INEEL High Level Waste (HLW) Program could become more familiar with retrieval and closure approaches that have been completed or are planned for underground storage tanks at the Oak Ridge National Laboratory (ORNL) and Hanford sites. This review focused not only on evaluation of the technical feasibility and appropriateness of the approach selected by INEEL but also on technology gaps that could be addressed through utilization of technologies or performance data available at other DOE sites and in the private sector. The reviewers, Judith Bamberger of Pacific Northwest National Laboratory (PNNL) and Dr. Barry Burks of The Providence Group Applied Technology, have extensive experience in the development and application of tank waste retrieval technologies for nuclear waste remediation.

  4. Technical Review of Retrieval and Closure Plans for the INEEL INTEC Tank Farm Facility

    Energy Technology Data Exchange (ETDEWEB)

    Bamberger, Judith A; Burks, Barry L; Quigley, Keith D; Falter, Diedre D

    2001-09-28

    The purpose of this report is to document the conclusions of a technical review of retrieval and closure plans for the Idaho National Energy and Environmental Laboratory (INEEL) Idaho Nuclear Technology and Engineering Center (INTEC) Tank Farm Facility. In addition to reviewing retrieval and closure plans for these tanks, the review process served as an information exchange mechanism so that staff in the INEEL High Level Waste (HLW) Program could become more familiar with retrieval and closure approaches that have been completed or are planned for underground storage tanks at the Oak Ridge National Laboratory (ORNL) and Hanford sites. This review focused not only on evaluation of the technical feasibility and appropriateness of the approach selected by INEEL but also on technology gaps that could be addressed through utilization of technologies or performance data available at other DOE sites and in the private sector. The reviewers, Judith Bamberger of Pacific Northwest National Laboratory (PNNL) and Dr. Barry Burks of The Providence Group Applied Technology, have extensive experience in the development and application of tank waste retrieval technologies for nuclear waste remediation.

  5. Permanent Closure of the TAN-664 Underground Storage Tank

    Energy Technology Data Exchange (ETDEWEB)

    Bradley K. Griffith

    2011-12-01

    This closure package documents the site assessment and permanent closure of the TAN-664 gasoline underground storage tank in accordance with the regulatory requirements established in 40 CFR 280.71, 'Technical Standards and Corrective Action Requirements for Owners and Operators of Underground Storage Tanks: Out-of-Service UST Systems and Closure.'

  6. 25 CFR 573.6 - Order of temporary closure.

    Science.gov (United States)

    2010-04-01

    ... or a customer. (7) A management contractor operates for business without a contract that the Chairman... 25 Indians 2 2010-04-01 2010-04-01 false Order of temporary closure. 573.6 Section 573.6 Indians... ENFORCEMENT § 573.6 Order of temporary closure. (a) When an order of temporary closure may issue...

  7. Pulmonary edema following transcatheter closure of atrial septal defect

    Directory of Open Access Journals (Sweden)

    Singhi Anil

    2010-01-01

    Full Text Available Pulmonary edema after device closure of atrial septal defect (ASD is a rare complication. We present illustrative images of a case of pulmonary edema after device closure of ASD in a 53 year old adult. Older patients undergoing ASD closure can benefit from their left atrial and left ventricular end diastolic pressures measurement before and after temporary balloon occlusion of ASD.

  8. A Simple Method for Thoracotomy Closure Avoiding Intercostal Nerve Damage

    Directory of Open Access Journals (Sweden)

    Ufuk Cagirici

    2016-09-01

    Full Text Available It is well known that intercostal nerve damage during thoracotomy closure causes severe postoperative pain. A simple closure technique is proposed for intercostal nerve-sparing during thoracotomy opening and closure. We think that this maneuver may avoid intercostal nerve compression.

  9. 27 CFR 28.102 - Bottles to have closures affixed.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bottles to have closures... Transportation to a Manufacturing Bonded Warehouse § 28.102 Bottles to have closures affixed. Every bottle containing distilled spirits to be withdrawn under the provisions of this subpart shall have a closure...

  10. 78 FR 1206 - Second Extension of Hearing Record Closure Date

    Science.gov (United States)

    2013-01-08

    ... SAFETY BOARD Second Extension of Hearing Record Closure Date AGENCY: Defense Nuclear Facilities Safety Board. ACTION: Second extension of hearing record closure date. SUMMARY: The Defense Nuclear Facilities... closure date to January 2, 2013 (77 FR 65871). Extension of Time: The Board now extends the period of...

  11. IDENTIFICATION OF DOE'S POST-CLOSURE MONITORING NEEDS AND REQUIREMENTS

    Energy Technology Data Exchange (ETDEWEB)

    M.A. Ebadian, Ph.D.

    1999-01-01

    The 2006 plan sets an ambitious agenda for the U.S. Department of Energy (DOE), Office of Environmental Management (EM) and the remediation of sites contaminated by decades of nuclear weapons production activities. The plan's primary objective is to reduce overall clean up costs by first eliminating the environmental problems that are most expensive to control and safely maintain. In the context of the 2006 Plan, closure refers to the completion of area or facility specific cleanup projects. The cleanup levels are determined by the planned future use of the site or facility. Use restrictions are still undecided for most sites but are highly probable to exclude residential or agricultural activities. Most of the land will be remediated to ''industrial use'' levels with access restrictions and some areas will be closed-off through containment. Portions of the site will be reserved for waste disposal, either as a waste repository or the in-situ immobilization of contaminated soil and groundwater, and land use will be restricted to waste disposal only. The land used for waste disposal will require monitoring and maintenance activities after closure. Most of the land used for industrial use may also require such postclosure activities. The required postclosure monitoring and maintenance activities will be imposed by regulators and stakeholders. Regulators will not approve closure plans without clearly defined monitoring methods using approved technologies. Therefore, among all other more costly and labor-intensive closure-related activities, inadequate planning for monitoring and lack of appropriate monitoring technologies can prevent closure. The purpose of this project is to determine, document, and track the current and evolving postclosure monitoring requirements at DOE-EM sites. This information will aid CMST-CP in guiding its postclosure technology development and deployment efforts.

  12. Automated 3D Analysis of Pre-Procedural MDCT to Predict Annulus Plane Angulation and C-Arm Positioning Benefit on Procedural Outcome in Patients Referred for TAVR

    NARCIS (Netherlands)

    Samim, Mariam; Stella, Pieter R.; Agostoni, Pierfrancesco; Kluin, Jolanda; Ramjankhan, Faiez; Budde, Ricardo P. J.; Sieswerda, Gertjan; Algeri, Emanuela; van Belle, Camille; Elkalioubie, Ahmed; Juthier, Francis; Belkacemi, Anouar; Bertrand, Michel E.; Doevendans, Pieter A.; Van Belle, Eric

    2013-01-01

    OBJECTIVES The aim of this study was to determine whether pre-procedural analysis of multidetector row computed tomography (MDCT) scans could accurately predict the "line of perpendicularity" (LP) of the aortic annulus and corresponding C-arm angulations required for prosthesis delivery and impact t

  13. An experimental study of regime transitions in a differentially heated baroclinic annulus with flat and sloping bottom topographies

    CERN Document Server

    Vincze, Miklos; von Larcher, Thomas; Egbers, Christoph

    2013-01-01

    A series of laboratory experiments has been carried out in a thermally driven rotating annulus to study the onset of baroclinic instability, using horizontal and uniformly sloping bottom topographies. Different wave flow regimes have been identified and their phase boundaries -- expressed in terms of appropriate non-dimensional parameters -- have been compared to the recent numerical results of \\citet{thomas_slope}. In the flat bottom case, the numerically predicted alignment of the boundary between the axisymmetric and the regular wave flow regime was found to be consistent with the experimental results. However, once the sloping bottom end wall was introduced, the detected behaviour was qualitatively different from that of the simulations. This disagreement is thought to be the consequence of nonlinear wave-wave interactions that could not be resolved in the framework of the numerical study. This argument is supported by the observed development of interference vacillation in the runs with sloping bottom, a...

  14. 77 FR 75186 - Notice of Closure, Target Shooting Public Safety Closure on the Lake Mountains in Utah County, UT

    Science.gov (United States)

    2012-12-19

    ... Bureau of Land Management Notice of Closure, Target Shooting Public Safety Closure on the Lake Mountains... approximately 900 acres of public land on the Lake Mountains in Utah County, Utah, to recreational target... Lake Mountains area. DATES: This target shooting closure within the described area will remain in...

  15. Temporary Closure of the Open Abdomen: A Systematic Review on Delayed Primary Fascial Closure in Patients with an Open Abdomen

    NARCIS (Netherlands)

    Boele van Hensbroek, P.; Wind, J.; Dijkgraaf, M.G.W.; Busch, O.R.C.; Goslings, J.C.

    2009-01-01

    Background This study was designed to systematically review the literature to assess which temporary abdominal closure (TAC) technique is associated with the highest delayed primary fascial closure (FC) rate. In some cases of abdominal trauma or infection, edema or packing precludes fascial closure

  16. Temporary Closure of the Open Abdomen: A Systematic Review on Delayed Primary Fascial Closure in Patients with an Open Abdomen

    NARCIS (Netherlands)

    Boele van Hensbroek, P.; Wind, J.; Dijkgraaf, M.G.W.; Busch, O.R.C.; Goslings, J.C.

    2009-01-01

    Background This study was designed to systematically review the literature to assess which temporary abdominal closure (TAC) technique is associated with the highest delayed primary fascial closure (FC) rate. In some cases of abdominal trauma or infection, edema or packing precludes fascial closure

  17. A new interferometer architecture combining nulling with phase closure measurements

    CERN Document Server

    Lacour, S; Monnier, J D; Kotani, T; Gauchet, L; Labeye, P

    2013-01-01

    Imaging the direct light signal from a faint exoplanet against the overwhelming glare of its host star presents one of the fundamental challenges to modern astronomical instrumentation. Achieving sufficient signal-to-noise for detection by direct imaging is limited by three basic physical processes: aberration of the wavefronts (both instrumental and atmospheric), photon noise, and detector noise. In this paper, we advance a novel optical setup which synthesizes the advantages of two different techniques: nulling interferometry to mitigate photon noise, and closure phase to combat optical aberrations. Our design, which employs technology from integrated optics and photonics, is intended to combine the advantageous aspects of both a coronagraph and a non-redundant interferometer. We show that such an instrument would allow readout noise limited detection of exoplanets, even in the presence of residual co-phasing errors. As a result, this concept would be ideal for space interferometry and for ground based obse...

  18. Study on solid liquid interface heat transfer of PCM under simultaneous charging and discharging (SCD) in horizontal cylinder annulus

    Science.gov (United States)

    Omojaro, Adebola Peter; Breitkopf, Cornelia

    2017-07-01

    Heat transfer performance during the simultaneous charging and discharging (SCD) operation process for phase change materials (PCM) contained inside the annulus of concentric horizontal cylinder was investigated. In the experimental set-up, the PCM inside the annulus serves as the heat sink along with an externally imposed forced cooling air. The obtained time wise temperature profile was used to determine the effects of different heat fluxes and the imposed forced convection cooling on the melt fraction values and the transition shift time from the observed conduction to natural convection heat transfer patterns. Furthermore, non-dimensional analysis was presented for the heat transfer at the interface to enable generalizing the result. Comparison of the results show that the SCD operation mode establish the condition that enables much PCM phase transition time and thus longer time of large latent heat transfer effect than the Partial and non simultaneous operations. Analysis results show that the variation of the heat flux for the SCD mode did not change the dominance of the natural convection over conduction heat transfers in the PCM. However, it significantly influences the commencement/transition shift time and melting rate while higher heat fluxes yields melt fraction that was 38-63% more for investigated process time. Variation with different cooling air flow rate shows more influences on the melt fraction than on the mode of heat transfer occurring in the PCM during melting. Available non-SCD modes correlation was shown to be insufficient to accurately predict interface heat transfer for the SCD modes.

  19. Three-dimensional development of tensile pre-strained annulus fibrosus cells for tissue regeneration: An in-vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Chuah, Yon Jin [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459 (Singapore); Lee, Wu Chean [University Hospital Conventry & Warwickshire NHS Trust, Clifford Bridge Road, West Midlands CV2, 2DX (United Kingdom); Wong, Hee Kit [Department of Orthopedic Surgery, National University Health System, NUHS Tower Block Level 11, 1E Kent Ridge Road, Singapore 119228 (Singapore); Kang, Yuejun, E-mail: yuejun.kang@ntu.edu.sg [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459 (Singapore); Hee, Hwan Tak, E-mail: HTHee@ntu.edu.sg [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459 (Singapore); Pinnacle Spine & Scoliosis Centre, 3 Mount Elizabeth, Mount Elizabeth Medical Centre, #04-07, Singapore 228510 (Singapore); School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637459 (Singapore)

    2015-02-01

    Prior research has investigated the immediate response after application of tensile strain on annulus fibrosus (AF) cells for the past decade. Although mechanical strain can produce either catabolic or anabolic consequences to the cell monolayer, little is known on how to translate these findings into further tissue engineering applications. Till to date, the application and effect of tensile pre-strained cells to construct a three-dimensional (3D) AF tissue remains unknown. This study aims to investigate the effect of tensile pre-strained exposure of 1 to 24 h on the development of AF pellet culture for 3 weeks. Equibiaxial cyclic tensile strain was applied on AF monolayer cells over a period of 24 h, which was subsequently developed into a cell pellet. Investigation on cellular proliferation, phenotypic gene expression, and histological changes revealed that tensile pre-strain for 24 h had significant and lasting effect on the AF tissue development, with enhanced cell proliferation, and up-regulation of collagen type I, II, and aggrecan expression. Our results demonstrated the regenerative ability of AF cell pellets subjected to 24 h tensile pre-straining. Knowledge on the effects of tensile pre-strain exposure is necessary to optimize AF development for tissue reconstruction. Moreover, the tensile pre-strained cells may further be utilized in either cell therapy to treat mild disc degeneration disease, or the development of a disc construct for total disc replacement. - Highlights: • Establishment of tensile pre-strained cell line population for annulus development. • Tensile strain limits collagen gene expression declination in monolayer culture. • Tensile pre-strained cells up-regulate their matrix protein in 3D pellet culture.

  20. The transmembrane heparan sulphate proteoglycan syndecan-4 is involved in establishment of the lamellar structure of the annulus fibrosus of the intervertebral disc.

    Science.gov (United States)

    Beckett, M C; Ralphs, J R; Caterson, B; Hayes, A J

    2015-08-14

    The annulus fibrosus of the intervertebral disc unites adjacent vertebral bodies along the length of the spine and provides tensile resistance towards compressive, twisting and bending movements arising through gait. It consists of a nested series of oriented collagenous lamellae, arranged in cross-ply circumferentially around the nucleus pulposus. The organisation of oriented collagen in the annulus is established during foetal development by an identical arrangement of oriented fibroblasts that are precisely organised into cell sheets, or laminae. These provide a template for ordered deposition of extracellular matrix material on cell surfaces, by means of a poorly understood mechanism involving the actin cytoskeleton. In this study, we investigate the role of two cell surface heparan sulphate proteoglycans (HSPGs), glypican-6 and syndecan-4, in the matrix assembly process in the developmental rat intervertebral disc. We compare their expression patterns with those of heparan sulphate and the interactive, cell-surface adhesive glycoprotein, fibronectin, and relate these to the stage-specific collagenous architectures present within the annulus at both light and electron microscopic levels. We show that both proteoglycans are strongly associated with the development, growth and aging of the intervertebral disc. Furthermore, the immunohistochemical labelling patterns suggest that syndecan-4, in particular, plays a potentially-significant role in annulus formation. We propose that this HSPG mediates interaction between the actin cytoskeleton and nascent extracellular matrix in the lamellar organisation of annulus tissue. These data add considerably towards an understanding of how cells organise and maintain complex, oriented extracellular matrices and has particular clinical relevance to the fields of tissue engineering and repair.

  1. Suitability of Exoseal Vascular Closure Device for Antegrade Femoral Artery Puncture Site Closure

    Energy Technology Data Exchange (ETDEWEB)

    Schmelter, Christopher, E-mail: christopher.schmelter@klinikum-ingolstadt.de; Liebl, Andrea; Poullos, Nektarios [Klinikum Ingolstadt, Department of Diagnostic and Interventional Radiology (Germany); Ruppert, Volker [Klinikum Ingolstadt, Department of Vascular Surgery (Germany); Vorwerk, Dierk [Klinikum Ingolstadt, Department of Diagnostic and Interventional Radiology (Germany)

    2013-06-15

    Purpose. To assess the efficacy and safety of the Exoseal vascular closure device for antegrade puncture of the femoral artery. Methods. In a prospective study from February 2011 to January 2012, a total of 93 consecutive patients received a total of 100 interventional procedures via an antegrade puncture of the femoral artery. An Exoseal vascular closure device (6F) was used for closure in all cases. Puncture technique, duration of manual compression, and use of compression bandages were documented. All patients were monitored by vascular ultrasound and color-coded duplex sonography of their respective femoral artery puncture site within 12 to 36 h after angiography to check for vascular complications. Results. In 100 antegrade interventional procedures, the Exoseal vascular closure device was applied successfully for closure of the femoral artery puncture site in 96 cases (96 of 100, 96.0 %). The vascular closure device could not be deployed in one case as a result of kinking of the vascular sheath introducer and in three cases because the bioabsorbable plug was not properly delivered to the extravascular space adjacent to the arterial puncture site, but instead fully removed with the delivery system (4.0 %). Twelve to 36 h after the procedure, vascular ultrasound revealed no complications at the femoral artery puncture site in 93 cases (93.0 %). Minor vascular complications were found in seven cases (7.0 %), with four cases (4.0 %) of pseudoaneurysm and three cases (3.0 %) of significant late bleeding, none of which required surgery. Conclusion. The Exoseal vascular closure device was safely used for antegrade puncture of the femoral artery, with a high rate of procedural success (96.0 %), a low rate of minor vascular complications (7.0 %), and no major adverse events.

  2. The proposal of the closure element pipe

    Directory of Open Access Journals (Sweden)

    Fojtášek Kamil

    2017-01-01

    Full Text Available The present paper summarizes the basic equations describing the behavior of butterfly valves during the fluid flow. Butterfly valves are used as a safety element in the energy industry, petrochemical industry, in steam lines etc. The paper describes the theoretical determination of the control torque on the closure element, the torque causes the opening and closing of butterfly valve. Determination of this torque depends on many factors, geometry of the closure element, misalignment to the axis of fluid flow, control method of valve, method of imposition of the moving member and of course on the operating parameters. Correct determination of the torque affects the proper design butterfly valves and ensure its functionality, which can prevent damage to other elements of the monitoring system.

  3. The proposal of the closure element pipe

    Science.gov (United States)

    Fojtášek, Kamil; Krutil, Jaroslav; Dvořák, Lukáš

    The present paper summarizes the basic equations describing the behavior of butterfly valves during the fluid flow. Butterfly valves are used as a safety element in the energy industry, petrochemical industry, in steam lines etc. The paper describes the theoretical determination of the control torque on the closure element, the torque causes the opening and closing of butterfly valve. Determination of this torque depends on many factors, geometry of the closure element, misalignment to the axis of fluid flow, control method of valve, method of imposition of the moving member and of course on the operating parameters. Correct determination of the torque affects the proper design butterfly valves and ensure its functionality, which can prevent damage to other elements of the monitoring system.

  4. A regenerative approach towards mucosal fenestration closure.

    Science.gov (United States)

    Gandi, Padma; Anumala, Naveen; Reddy, Amarender; Chandra, Rampalli Viswa

    2013-06-06

    Mucosal fenestration is an opening or an interstice through the oral mucosa. A lesion which occurs with greater frequency than generally realised, its occurrence is attributed to a myriad of causes. Mucogingival procedures including connective tissue grafts, free gingival grafts and lateral pedicle grafts are generally considered to be the treatment of choice in the closure of a mucosal fenestration. More often, these procedures are performed in conjunction with other procedures such as periradicular surgery and with bone grafts. However, the concomitant use of gingival grafts and bone grafts in mucosal fenestrations secondary to infections in sites exhibiting severe bone loss is highly debatable. In this article, we report two cases of mucosal fenestrations secondary to trauma and their management by regenerative periodontal surgery with the placement of guided tissue regeneration membrane and bone graft. The final outcome was a complete closure of the fenestration in both the cases.

  5. The Galois closure of Drinfeld modular towers

    DEFF Research Database (Denmark)

    Bassa, Alp; Beelen, Peter

    2011-01-01

    In this article we study Drinfeld modular curves X0(pn) associated to congruence subgroups Γ0(pn) of GL(2,Fq[T]) where p is a prime of Fq[T]. For n>r>0 we compute the extension degrees and investigate the structure of the Galois closures of the covers X0(pn)→X0(pr) and some of their variations. T...

  6. Notice of car park and road closures

    CERN Multimedia

    2006-01-01

    The arrival of one of the end caps of the CMS Tracker in Building 186 will result in the temporary closure of the following car parks: Building186: south entrance Building 613 Building 28 Building181: south entrance Building 600 Building 31 Route Oppenheimer The car parks concerned will be closed from Monday 30 October until the evening of Tuesday 31 October. Thank you for your cooperation. PH-CMT Group Tel. 164569

  7. Notice of car park and road closures

    CERN Multimedia

    2006-01-01

    The arrival of one of the end caps of the CMS Tracker in Building 186 will result in the temporary closure of the following car parks: Building186: south entrance Building 613 Building 28 Building181: south entrance Building 600 Building 31 Route Oppenheimer The car parks concerned will be closed from Sunday 22 October until the evening of Monday 23 October. Thank you for your cooperation. PH-CMT Group Tel. 164569

  8. Calcined solids storage facility closure study

    Energy Technology Data Exchange (ETDEWEB)

    Dahlmeir, M.M.; Tuott, L.C.; Spaulding, B.C. [and others

    1998-02-01

    The disposal of radioactive wastes now stored at the Idaho National Engineering and Environmental Laboratory is currently mandated under a {open_quotes}Settlement Agreement{close_quotes} (or {open_quotes}Batt Agreement{close_quotes}) between the Department of Energy and the State of Idaho. Under this agreement, all high-level waste must be treated as necessary to meet the disposal criteria and disposed of or made road ready to ship from the INEEL by 2035. In order to comply with this agreement, all calcined waste produced in the New Waste Calcining Facility and stored in the Calcined Solids Facility must be treated and disposed of by 2035. Several treatment options for the calcined waste have been studied in support of the High-Level Waste Environmental Impact Statement. Two treatment methods studied, referred to as the TRU Waste Separations Options, involve the separation of the high-level waste (calcine) into TRU waste and low-level waste (Class A or Class C). Following treatment, the TRU waste would be sent to the Waste Isolation Pilot Plant (WIPP) for final storage. It has been proposed that the low-level waste be disposed of in the Tank Farm Facility and/or the Calcined Solids Storage Facility following Resource Conservation and Recovery Act closure. In order to use the seven Bin Sets making up the Calcined Solids Storage Facility as a low-level waste landfill, the facility must first be closed to Resource Conservation and Recovery Act (RCRA) standards. This study identifies and discusses two basic methods available to close the Calcined Solids Storage Facility under the RCRA - Risk-Based Clean Closure and Closure to Landfill Standards. In addition to the closure methods, the regulatory requirements and issues associated with turning the Calcined Solids Storage Facility into an NRC low-level waste landfill or filling the bin voids with clean grout are discussed.

  9. A Quadratic Closure for Compressible Turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Futterman, J A

    2008-09-16

    We have investigated a one-point closure model for compressible turbulence based on third- and higher order cumulant discard for systems undergoing rapid deformation, such as might occur downstream of a shock or other discontinuity. In so doing, we find the lowest order contributions of turbulence to the mean flow, which lead to criteria for Adaptive Mesh Refinement. Rapid distortion theory (RDT) as originally applied by Herring closes the turbulence hierarchy of moment equations by discarding third order and higher cumulants. This is similar to the fourth-order cumulant discard hypothesis of Millionshchikov, except that the Millionshchikov hypothesis was taken to apply to incompressible homogeneous isotropic turbulence generally, whereas RDT is applied only to fluids undergoing a distortion that is 'rapid' in the sense that the interaction of the mean flow with the turbulence overwhelms the interaction of the turbulence with itself. It is also similar to Gaussian closure, in which both second and fourth-order cumulants are retained. Motivated by RDT, we develop a quadratic one-point closure for rapidly distorting compressible turbulence, without regard to homogeneity or isotropy, and make contact with two equation turbulence models, especially the K-{var_epsilon} and K-L models, and with linear instability growth. In the end, we arrive at criteria for Adaptive Mesh Refinement in Finite Volume simulations.

  10. Stochastic particle acceleration and statistical closures

    Energy Technology Data Exchange (ETDEWEB)

    Dimits, A.M.; Krommes, J.A.

    1985-10-01

    In a recent paper, Maasjost and Elsasser (ME) concluded, from the results of numerical experiments and heuristic arguments, that the Bourret and the direct-interaction approximation (DIA) are ''of no use in connection with the stochastic acceleration problem'' because (1) their predictions were equivalent to that of the simpler Fokker-Planck (FP) theory, and (2) either all or none of the closures were in good agreement with the data. Here some analytically tractable cases are studied and used to test the accuracy of these closures. The cause of the discrepancy (2) is found to be the highly non-Gaussian nature of the force used by ME, a point not stressed by them. For the case where the force is a position-independent Ornstein-Uhlenbeck (i.e., Gaussian) process, an effective Kubo number K can be defined. For K << 1 an FP description is adequate, and conclusion (1) of ME follows; however, for K greater than or equal to 1 the DIA behaves much better qualitatively than the other two closures. For the non-Gaussian stochastic force used by ME, all common approximations fail, in agreement with (2).

  11. Creativity & Cognitive Closure (Creatividad y cierre cognitivo

    Directory of Open Access Journals (Sweden)

    Melike Hazir

    2015-02-01

    Full Text Available Abstract The aim of this paper is to present the relationship between the need for cognitive closure (NFC and creativity. In light of previous research, a theoretical foundation is established for the term creativity. Next the social-cognitive phenomenon of the need for cognitive closure is explained based on the theory of Kruglanski and Webster, and considering the tendencies of urgency and permanency. Conclusion: The role of creativity is to control cognitive closure in order to solve problems that arise during the learning process and usually during the life. Resumen El objetivo de este trabajo es presentar la relación entre la necesidad de cierre cognitivo (NCC y la creatividad. A la luz de las investigaciones realizadas, se establece la base teórica para el término de creatividad y la explica del fenómeno socio-cognitivo de necesidad de cierre cognitivo en base a la teoría de Kruglanski y Webster, teniendo en cuenta las tendencias de urgencia y permanencia. Conclusión: La creatividad tiene un papel importante de control del cierre cognitivo con el fin de resolver los problemas que surjan durante el proceso de aprendizaje y en general durante la vida.

  12. Endonasal endoscopic closure of cerebrospinal fluid rhinorrhea.

    Science.gov (United States)

    Schmerber, S; Righini, C; Lavielle, J P; Passagia, J G; Reyt, E

    2001-02-01

    The authors review their experience with endoscopic repair of skull base defects associated with cerebrospinal fluid (CSF) rhinorrhea involving the paranasal sinuses. A total of 22 patients was treated endoscopically between 1992 and 1998. The repair method consisted of closure of the CSF fistula with a free autologous abdominal fat graft and fibrin glue, supported with a sheet of silastic. The primary closure rate was 82% (18/22), and the overall closure rate was 95.5% (21/22) without recurrence or complications within an average follow-up of 5 years (14-83 months). A single patient still complains of cerebrospinal rhinorrhea, although this was never proved by any clinical, endoscopic, or biological (beta(2)-transferrin) examination. The repair of ethmoidal-sphenoidal cerebrospinal fluid fistulae by endonasal endoscopic surgery is an excellent technique, both safe and effective. Fat is a material of choice, as it is tight and resists infection well. The technique and indications for endoscopic management of cerebrospinal fluid leaks are discussed.

  13. VR closure rates for two vocational models.

    Science.gov (United States)

    Fraser, Virginia V; Jones, Amanda M; Frounfelker, Rochelle; Harding, Brian; Hardin, Teresa; Bond, Gary R

    2008-01-01

    The Individual Placement and Support (IPS) model of supported employment is an evidence-based practice for individuals with psychiatric disabilities. To be financially viable, IPS programs require funding from the state-federal vocational rehabilitation (VR) system. However, some observers have questioned the compatibility of IPS and the VR system. Using a randomized controlled trial comparing IPS to a well-established vocational program called the Diversified Placement Approach (DPA), we examined rates of VR sponsorship and successful VR closures. We also describe the establishment of an active collaboration between a psychiatric rehabilitation agency and the state VR system to facilitate rapid VR sponsorship for IPS clients. Both IPS and DPA achieved a 44% rate of VR Status 26 closure when considering all clients entering the study. IPS and DPA averaged similar amount of time to achieve VR sponsorship. Time from vocational program entry to Status 26 was 51 days longer on average for IPS. Even though several IPS principles seem to run counter to VR practices, such as zero exclusion and rapid job search, we found IPS closure rates comparable to those for DPA, a vocational model that screens for readiness, provides prevocational preparation, and extensively uses agency-run businesses.

  14. TRANSCATHETER CLOSURE OF PATENT DUCTUS ARTERIOSUS

    Institute of Scientific and Technical Information of China (English)

    高伟; 周爱卿; 余志庆; 李奋; 王荣发; 黄美蓉

    2002-01-01

    Objective To explore the efficacy of transcatheter closure of patent ductus arteriosus (PDA) with detachable coil and Amplatzer duct occluder (ADO). Methods Transcatheter colsure of PDA was performed in 160 cases, aged 4.56±2.67 years, of whom 3 had residual shunt after surgical ligation, 2 had pulmomary stenosis (PS), 1 had coarctation of aorta (COA), 1 had right aortic arch, and 2 had atrial septal defect (ASD). Results Detachable coils (Duct Occlude pfm or Cook Inc) were successfully used in 51 patients with a smallest PDA diameter of 1.86±0.78mm. Amplatzer duct occluders were also successfully performed in other 109 with a moderate to large PDA diameter of 3.89±1.32mm, of whom 3 with PS or COA were performed balloon dilation firstly, and 2 with ASD were performed PDA occlusion firstly; 1 month to 4.8years follow-up coil or Amplatzer device closure of PDA showed that neither residual shunt nor any complication. Conclusion It is suggested that the detachable coil and Amplatzer duct occluder are simple and safe for the catheter closure from small to large sized PDA.

  15. Folate receptors and neural tube closure.

    Science.gov (United States)

    Saitsu, Hirotomo

    2017-02-28

    Neural tube defects (NTD) are among the most common human congenital malformations, affecting 0.5-8/1000 of live births. Human clinical trials have shown that periconceptional folate supplementation significantly decreases the occurrence of NTD in offspring. However, the mechanism by which folate acts on NTD remains largely unknown. Folate receptor (Folr) is one of the three membrane proteins that mediate cellular uptake of folates. Recent studies suggest that mouse Folr1 (formerly referred to as Fbp1) is essential for neural tube closure. Therefore, we examined spatial and temporal expression patterns of Folr1 in developing mouse embryos, showing a close association between Folr1 and anterior neural tube closure. Transient transgenic analysis was performed using lacZ as a reporter; we identified a 1.1-kb enhancer that directs lacZ expression in the neural tube and optic vesicle in a manner that is similar to endogenous Folr1. The 1.1-kb enhancer sequences were highly conserved between humans and mice, suggesting that human FOLR1 is associated with anterior neural tube closure in humans. Several experimental studies in mice and human epidemiological and genetics studies have suggested that folate receptor abnormalities are involved in a portion of human NTDs, although the solo defect of FOLR1 did not cause NTD.

  16. Hospital admissions before and after shipyard closure.

    Science.gov (United States)

    Bartley, M; Fagin, L

    1990-03-01

    "To determine the effect of job loss on health an investigation was made of admissions to hospitals in 887 men five years before and three years after the closure of a Danish shipyard. The control group comprised 441 men from another shipyard. The information on hospital admissions was obtained from the Danish national register of patients. The relative risk of admission in the control group dropped significantly in terms of the number of men admitted from the study group from 1.29 four to five years before closure to 0.74 in the three years after closure. This was especially true of admissions due to accidents (1.33 to 0.46) and diseases of the digestive system (4.53 to 1.03). For diseases of the circulatory system, particularly cardiovascular diseases, the relative risk increased from 0.8 to 1.60, and from 1.0 to 2.6 respectively. These changes in risk of illness after redundancy are probably a consequence of a change from the effects of a high risk work environment to the effects of psychosocial stresses such as job insecurity and unemployment."

  17. 3718-F Alkali Metal Treatment and Storage Facility Closure Plan

    Energy Technology Data Exchange (ETDEWEB)

    None

    1991-12-01

    Since 1987, Westinghouse Hanford Company has been a major contractor to the U.S. Department of Energy-Richland Operations Office and has served as co-operator of the 3718-F Alkali Metal Treatment and Storage Facility, the waste management unit addressed in this closure plan. The closure plan consists of a Part A Dangerous waste Permit Application and a RCRA Closure Plan. An explanation of the Part A Revision (Revision 1) submitted with this document is provided at the beginning of the Part A section. The closure plan consists of 9 chapters and 5 appendices. The chapters cover: introduction; facility description; process information; waste characteristics; groundwater; closure strategy and performance standards; closure activities; postclosure; and references.

  18. Role of Inclined Magnetic Field and Copper Nanoparticles on Peristaltic Flow of Nanofluid through Inclined Annulus: Application of the Clot Model

    Science.gov (United States)

    Shahzadi, Iqra; Nadeem, S.

    2017-06-01

    A genuine neurotic condition is experienced when some blood constituents accumulate on the wall of the artery get withdrew from the wall, again join the circulatory system and coagulation occur. Role of copper nanoparticles and inclined magnetic field on the peristaltic flow of a nanofluid in an annular region of inclined annulus is investigated. We represent the clot model by considering the small artery as an annulus whose outer tube has a wave of sinusoidal nature and inner tube has a clot on its walls. Lubrication approach is used to simplify the problem. Close form solutions are determined for temperature and velocity profile. Impact of related parameters on pressure rise, pressure gradient, velocity and streamlines are interpreted graphically. Comparison among the pure blood and copper blood is presented and analyzed. One main finding of the considered analysis is that the inclusion of copper nanoparticles enlarges the amplitude of the velocity. Therefore, the considered study plays a dominant role in biomedical applications.

  19. AN EXPERIMENTAL STUDY ON EFFECTS OF THE BETA TOPOGRAPHY ON SURFACE FLOWS IN A ROTATING ANNULUS SUBJECT TO RADIAL TEMPERATURE GRADIENT

    Institute of Scientific and Technical Information of China (English)

    LIN Shang-jing; WEI Gang; LIU Li-long; LIU Yu-di

    2005-01-01

    Beta effects on surface flows in a rotating annulus with a radial temperature gradient and a sloping bottom were studied experimentally. An azimuthal jet was produced by the action of the Coriolis force in the convective region between the two side walls of the annulus. Propagating velocity and patterns of the baroclinic wave on the surface were obtained by using a frequency-meter and a streak photograph respectively. It is shown that there exists the nonlinear interaction between the baroclinic and beta effects. The beta effect exerts little influence on the stratification flows and constrains the baroclinic instability, and it prompts the instability of the weak stratification flows and results in the surface pattern of waves with higher frequency. It is also indicated that the beta effect can reduce the propagating speed of the surface waves in the jet, and increase the thermal Rossby number for those same surface patterns under a given Taylor number.

  20. [A case report of aortic valvuloplasty by rasping technique for aortic stenosis with small annulus simultaneously performed with mitral valve replacement].

    Science.gov (United States)

    Taniyasu, N; Kou, E; Hiramatsu, T; Yokoyama, S; Takenaka, A; Ikawa, O

    1997-02-01

    The patient was a 48-year-old woman with aortic stenosis and regurgitation and mitral stenosis. Preoperative cardiac catheterization revealed LV-Ao pressure gradient of 30 mmHg and regurgitation of Sellers III. The aortic annulus was measured less than 19 mm. As operative findings, the aortic annulus seemed to be too small to be replaced with 19 mm prosthetic valve. Aortic valvuloplasty (AVP) with rasping technique was performed for the aortic valve and valve replacement was carried out for the mitral valve. After aortic declamping and occurring her beat, the transesophageal echocardiographic evaluation for AVP was effective. Postoperative course was uneventful. Postoperative cardiac catheterization have shown decreased transvalvular pressure gradient up to 10 mmHg and aortic regurgitation of Sellers I.

  1. Mechanism and Etiology of Primary Chronic Angle Closure Glaucoma

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    The ocular anatomic features, pupil-blocking force, status of angle synechiae closure and positivity of provocative tests were compared between the primary chronic angle closure glaucoma (PCACG) and primary a-cute angle closure glaucoma (PAACG) by using ultrasonic biometry, computerized anterior ocular segment image processing technique, gonioscopy and provocative tests. The studies showed that the anterior chamber depth of PAACG was shallower than that of PCACG; the pupil-blocking force of PAACG was st...

  2. Echocardiographic assessment and percutaneous closure of multiple atrial septal defects

    Directory of Open Access Journals (Sweden)

    Timperley Jonathan

    2004-07-01

    Full Text Available Abstract Atrial septal defect closure is now routinely performed using a percutaneous approach under echocardiographic guidance. Centrally located, secundum defects are ideal for device closure but there is considerable morphological variation in size and location of the defects. A small proportion of atrial septal defects may have multiple fenestrations and these are often considered unsuitable for device closure. We report three cases of multiple atrial septal defects successfully closed with two Amplatzer septal occluders.

  3. Rural pharmacy closures: implications for rural communities.

    Science.gov (United States)

    Todd, Kelli; Ullrich, Fred; Mueller, Keith

    2013-01-01

    Retail pharmacies provide essential services to residents of rural areas and serve many communities as the sole provider of pharmacist services. Losing the only retail pharmacy within a rural community (census designated city), and within a 10 mile radius based on driving distance ("sole community pharmacy"), may affect access to prescription and over-the-counter drugs and, in some cases, leave the community without proximate access to any clinical provider. This policy brief documents the closure of local retail pharmacies in which the pharmacist was the only clinical provider available in the community at the time the pharmacy closed. Characteristics of the community and the retail pharmacy are described. The findings may suggest future policy actions to minimize the risk or mitigate the negative consequences of pharmacy closures. Key Findings. (1) Between May 1, 2006, and October 31, 2010, 119 sole community pharmacies closed. (2) Of those 119 pharmacies, 31 were located in rural communities with no other health professionals or clinical providers. (3) In 16 states, at least 1 community lost a sole community retail pharmacy, and there was no other pharmacy within 10 miles (actual driving distance). (4) Of the 31 pharmacy closures in communities with no other providers, 17% were located in remote rural areas designated with a Rural-Urban Commuting Area (RUCA) score of 10 or higher. Such a score means that, on average, 60 minutes of travel time is required to reach an urbanized area, and 40 minutes is required to reach a large urban cluster of 20,000 population or more.

  4. Study on the post-closure surveillance methods at low- and intermediate-level radioactive waste disposal facility

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Joo Ho; Shin, Jin Seong; Lee, Jae Min; Choi, Won Cheol; Cheon, Tae Hoon [Kyunghee Univ., Seoul (Korea, Republic of)

    1996-02-15

    Presidential decree, of atomic energy act of Korea, number 233.3.9 requires that the repository, after closure, of low- and intermediate-level radioactive waste be controlled and monitored an Ministry of Science and Technology decides. This study emphasizes on establishing a direction of technical guides, considering rock cavern disposal as a domestic project. Other types of repositories will also be referred to for their technical matter. Review of domestic and foreign requirements, review of the objectives of post-closure surveillance, suggestion of surveillance methods and technical guides.

  5. Narrative Intelligibility and Closure in Interactive Systems

    DEFF Research Database (Denmark)

    Bruni, Luis Emilio; Baceviciute, Sarune

    2013-01-01

    ), which in turn can be seen as a function of Narrative Intelligibility. AAD can also be influenced by the intended or unintended level of abstractedness or didascalicity (i.e. figurativeness) of a given narrative. We define narrative intelligibility in complementarity with the related notion of Narrative...... Closure. We also make a distinction between the goals of the system and the goals of the narrative that it mediates, and consider the proposed parameters at two interrelated levels of analysis: the system level and the embedded narrative level, as the normative values and goals of these two levels should...

  6. 100-N Area underground storage tank closures

    Energy Technology Data Exchange (ETDEWEB)

    Rowley, C.A.

    1993-08-01

    This report describes the removal/characterization actions concerning underground storage tanks (UST) at the 100-N Area. Included are 105-N-LFT, 182-N-1-DT, 182-N-2-DT, 182-N-3-DT, 100-N-SS-27, and 100-N-SS-28. The text of this report gives a summary of remedial activities. In addition, correspondence relating to UST closures can be found in Appendix B. Appendix C contains copies of Unusual Occurrence Reports, and validated sampling data results comprise Appendix D.

  7. Defense Base Closure and Realignment Commission

    Science.gov (United States)

    1993-01-01

    international responsibilities with more limited resources. ýeS~ectfully yours , im Courter k,"Chairman CAPT Peter 𔃽owman, USN (Ret) C mBeverly Byr bea Cox...sub tania and, the forc tr- a clear decline in the period 1995-1999. Thus, turc plan and fial criteria and, therefore, theas te wrk clnes theexcss...restoration (cleanup) costs in the cost of closure, on the status of this request to the 1995 since DoD is obligated to clean up bases Commission. regardless

  8. Post Closure Safety of the Morsleben Repository

    Energy Technology Data Exchange (ETDEWEB)

    Preuss, J.; Eilers, G.; Mauke, R.; Moeller-Hoeppe, N.; Engelhardt, H.-J.; Kreienmeyer, M.; Lerch, C.; Schrimpf, C.

    2002-02-26

    After the completion of detailed studies of the suitability the twin-mine Bartensleben-Marie, situated in the Federal State of Saxony-Anhalt (Germany), was chosen in 1970 for the disposal of low and medium level radioactive waste. The waste emplacement started in 1978 in rock cavities at the mine's fourth level, some 500 m below the surface. Until the end of the operational phase in 1998 in total about 36,800 m{sup 3} of radioactive waste was disposed of. The Morsleben LLW/ILW repository (ERAM) is now under licensing for closure. After completing the licensing procedure the repository will be sealed and backfilled to exclude any undue future impact onto man or the environment. The main safety objective is to protect the biosphere from the harmful effects of the disposed radionuclides. Furthermore, classical or conventional requirements call for ruling out or minimizing other unfavorable environmental effects. The ERAM is an abandoned rock salt and potash mine. As a consequence it has a big void volume, however small parts of the cavities are backfilled with crushed salt rocks. Other goals of the closure concept are therefore a long-term stabilization of the cavities to prevent a dipping or buckling of the ground surface. In addition, groundwater protection shall be assured. For the sealing of the repository a closure concept was developed to ensure compliance with the safety protection objectives. The concept anticipates the backfilling of the cavities with hydraulically setting backfill materials (salt concretes). The reduction of the remaining void volume in the mine causes in the case of brine intrusions a limitation of the leaching processes of the exposed potash seams. However, during the setting process the hydration heat of the concrete will lead to an increase of the temperature and hence to thermally induced stresses of the concrete and the surrounding rocks. Therefore, the influence of these stresses and deformations on the stability of the salt body

  9. Multiple coil closure of isolated aortopulmonary collateral

    Directory of Open Access Journals (Sweden)

    Padhi Sumanta

    2010-01-01

    Full Text Available A 7-month-old girl was diagnosed to have large aortopulmonary collateral during evaluation for congestive heart failure. There was no other evidence of cardiopulmonary disease. The collateral was successfully closed with multiple coils delivered sequentially. We describe the issues associated during closure of the aortopulmonary collateral in this case. To the best of our knowledge, this is the first reported case of large aortopulmonary collateral presenting with heart failure in an otherwise structurally normal heart that was closed successfully with multiple coils delivered sequentially.

  10. Inspection and Gamma-Ray Dose Rate Measurements of the Annulus of the VSC-17 Concrete Spent Nuclear Fuel Storage Cask

    Energy Technology Data Exchange (ETDEWEB)

    P. L. Winston

    2007-09-01

    The air cooling annulus of the Ventilated Storage Cask (VSC)-17 spent fuel storage cask was inspected using a Toshiba 7 mm (1/4”) CCD video camera. The dose rates observed in the annular space were measured to provide a reference for the activity to which the camera(s) being tested were being exposed. No gross degradation, pitting, or general corrosion was observed.

  11. Performance of transonic fan stage with weight flow per unit annulus area of 208 kilograms per second per square meter (42.6 (lb/sec)/sq ft)

    Science.gov (United States)

    Urasek, D. C.; Kovich, G.; Moore, R. D.

    1973-01-01

    Performance was obtained for a 50-cm-diameter compressor designed for a high weight flow per unit annulus area of 208 (kg/sec)/sq m. Peak efficiency values of 0.83 and 0.79 were obtained for the rotor and stage, respectively. The stall margin for the stage was 23 percent, based on equivalent weight flow and total-pressure ratio at peak efficiency and stall.

  12. Effect of Thermo-Diffusion and Chemical Reaction on Mixed Convective Heat And Mass Transfer Through A Porous Medium In Cylindrical Annulus With Heat Source.

    Directory of Open Access Journals (Sweden)

    Dr.K.Gnaneswar

    2014-09-01

    Full Text Available A finite element study of combined heat and mass transfer flow through a porous medium in a circular cylindrical annulus with Soret and Dufour effects in the presence of heat sources has been analyzed. The coupled velocity, energy, and diffusion equations are solved numerically by using Galerkin- finite element technique. Shear stress, Nusslet number and Sherwood number are evaluated numerically for different values of the governing parameters under consideration and are shown in tabular form.

  13. CT-angiography-based evaluation of the aortic annulus for prosthesis sizing in transcatheter aortic valve implantation (TAVI-predictive value and optimal thresholds for major anatomic parameters.

    Directory of Open Access Journals (Sweden)

    Florian Schwarz

    Full Text Available BACKGROUND/OBJECTIVES: To evaluate the predictive value of CT-derived measurements of the aortic annulus for prosthesis sizing in transcatheter aortic valve implantation (TAVI and to calculate optimal cutoff values for the selection of various prosthesis sizes. METHODS: The local IRB waived approval for this single-center retrospective analysis. Of 441 consecutive TAVI-patients, 90 were excluded (death within 30 days: 13; more than mild aortic regurgitation: 10; other reasons: 67. In the remaining 351 patients, the CoreValve (Medtronic and the Edwards Sapien XT valve (Edwards Lifesciences were implanted in 235 and 116 patients. Optimal prosthesis size was determined during TAVI by inflation of a balloon catheter at the aortic annulus. All patients had undergone CT-angiography of the heart or body trunk prior to TAVI. Using these datasets, the diameter of the long and short axis as well as the circumference and the area of the aortic annulus were measured. Multi-Class Receiver-Operator-Curve analyses were used to determine the predictive value of all variables and to define optimal cutoff-values. RESULTS: Differences between patients who underwent implantation of the small, medium or large prosthesis were significant for all except the large vs. medium CoreValve (all p's<0.05. Furthermore, mean diameter, annulus area and circumference had equally high predictive value for prosthesis size for both manufacturers (multi-class AUC's: 0.80, 0.88, 0.91, 0.88, 0.88, 0.89. Using the calculated optimal cutoff-values, prosthesis size is predicted correctly in 85% of cases. CONCLUSION: CT-based aortic root measurements permit excellent prediction of the prosthesis size considered optimal during TAVI.

  14. U.S. Small Business HUBZone Base Closure Areas

    Data.gov (United States)

    Small Business Administration — HUBZone Qualitified Base Closure Areas - the lands within the boundaries of a military installation that was closed through a privatization process under the Federal...

  15. Effect of crack surface geometry on fatigue crack closure

    Energy Technology Data Exchange (ETDEWEB)

    Drury, W.J. [P and L Technologies, Inc., Atlanta, GA (United States); Gokhale, A.M. [Georgia Inst. of Tech., Atlanta, GA (United States). School of Materials Science and Engineering; Antolovich, S.D. [Washington State Univ., Pullman, WA (United States). School of Mechanical and Materials Engineering

    1995-10-01

    The geometry of crack faces often plays a critical role in reducing crack extension forces when crack closure occurs during fatigue crack growth. Most previous studies of fatigue crack closure are concerned with mechanical measure of closure as related to the crack growth rate; very little attention has been given to the geometry of the crack surfaces. The objective is to identify those aspects of crack surface geometry that are important in the closure process, to develop quantitative fractographic techniques to estimate such attributes in a statistically significant and robust manner, and to correlate them to the physical process of crack closure. For this purpose, fatigue crack propagation experiments were performed on a Ni-base superalloy and crack growth rates and crack closure loads were measured. Digital image profilometry and software-based analysis techniques were used for statistically reliable and detailed quantitative characterization of fatigue crack profiles. It is shown that the dimensionless, scale-independent attributes, such a height-to-width ratio of asperities, fractal dimensions, dimensionless roughness parameters, etc., do not represent the aspects of crack geometry that are of primary importance in the crack closure phenomena. Furthermore, it is shown that the scale-dependent characteristics, such as average asperity height, do represent the aspects of crack geometry that play an interactive role in the closure process. These observations have implications concerning the validity of geometry-dependent, closure-based models for fatigue crack growth.

  16. Transcatheter closure of patent ductus arteriosus: past, present and future.

    Science.gov (United States)

    Baruteau, Alban-Elouen; Hascoët, Sébastien; Baruteau, Julien; Boudjemline, Younes; Lambert, Virginie; Angel, Claude-Yves; Belli, Emre; Petit, Jérôme; Pass, Robert

    2014-02-01

    This review aims to describe the past history, present techniques and future directions in transcatheter treatment of patent ductus arteriosus (PDA). Transcatheter PDA closure is the standard of care in most cases and PDA closure is indicated in any patient with signs of left ventricular volume overload due to a ductus. In cases of left-to-right PDA with severe pulmonary arterial hypertension, closure may be performed under specific conditions. The management of clinically silent or very tiny PDAs remains highly controversial. Techniques have evolved and the transcatheter approach to PDA closure is now feasible and safe with current devices. Coils and the Amplatzer Duct Occluder are used most frequently for PDA closure worldwide, with a high occlusion rate and few complications. Transcatheter PDA closure in preterm or low-bodyweight infants remains a highly challenging procedure and further device and catheter design development is indicated before transcatheter closure is the treatment of choice in this delicate patient population. The evolution of transcatheter PDA closure from just 40 years ago with 18F sheaths to device delivery via a 3F sheath is remarkable and it is anticipated that further improvements will result in better safety and efficacy of transcatheter PDA closure techniques.

  17. A New Surgical Technique for Closure of Pilonidal Sinus Defects: Triangular Closure Technique

    Science.gov (United States)

    Mutaf, Mehmet; Temel, Metin; Koç, Mustafa Nihat

    2017-01-01

    Background We present a clinical experience with a new local flap procedure, namely the triangular closure technique, for reconstruction of sacrococcygeal skin defects resulting from excision of the pilonidal sinus. Material/Methods In this technique, the defect is surgically converted to a triangle in shape. Then, the triangular defect is closed by transposition of 2 skin flaps designed in an unequal z-plasty manner. Over 6 years, this technique has been used for closure of defects of chronic pilonidal sinus disease in 27 patients (6 females, 21 males). The size of the defect ranged between 3.5 cm and 12 cm in dimension. Results A tension-free defect closure was obtained in all patients. All flaps except one healed with no complications. A mean follow-up of 3.62±1.77 months revealed aesthetically and functionally acceptable results with the obliteration of the natal cleft in all patients. No recurrence was observed in the follow-up period. Conclusions The triangular closure technique was found to be a useful technique for the treatment of pilonidal sinus with favorable results regarding the time before return to work. PMID:28238003

  18. Iterative Learning of Transcatheter Mitral Valve Replacement in Mitral Valve Annulus Calcification: Management and Prevention of Transcatheter Mitral Valve Replacement Dislocation.

    Science.gov (United States)

    Hulman, Michal; Bena, Martin; Artemiou, Panagiotis; Gasparovic, Ivo; Hudec, Vladan; Rajani, Ronak; Bapat, Vinayak

    2016-10-01

    Transcatheter mitral valve replacement using balloon-expandable valves is an emerging technique for the treatment of patients with significant mitral regurgitation who have been judged to be inoperable owing to significant mitral valve annulus calcification. Although initial reports have been promising, there remains a lack of consensus as to how to plan for transcatheter mitral valve replacement deployment in terms of appropriateness, sizing, and positioning to mitigate the risks of valve displacement and paravalvular regurgitation. We describe two cases of transcatheter mitral valve replacement in patients with significant mitral valve annulus calcification. The first was complicated by valve displacement into the left atrium, which was successfully managed by surgical redeployment and fixation. The second case was thereafter performed successfully using iterative learning and the application of specific preprocedural planning techniques acquired from a root cause analysis of the first case. We describe our experience with both cases and the specific planning principles required to prevent transcatheter mitral valve replacement displacement in patients with mitral valve annulus calcification.

  19. Use of the Konno procedure in an 80-year-old woman with aortic stenosis, a narrow left ventricular outflow tract, and a small aortic annulus.

    Science.gov (United States)

    Misumi, Hiroyasu; Katayama, Yukihiro; Takaji, Kentaro; Oshitomi, Takashi; Uesugi, Hideyuki; Hirayama, Touitsu; Takeuchi, Takamasa

    2014-01-01

    This report describes a technique for repairing an aortic stenosis in an elderly patient with a small aortic annulus and a narrow left ventricular outflow tract. Preoperative echocardiography in an 80-year-old woman showed severe aortic stenosis with a narrow outflow tract: the aortic valve area was 0.48 cm(2), the aortic annular diameter was 14 mm, and the left ventricular outflow tract diameter was 14 mm. The Konno procedure was used to enlarge both the small aortic annulus and the left ventricular outflow tract, and a 19-mm Carpentier-Edwards bioprosthetic valve was implanted. The patient's postoperative course was uneventful. The left ventricular mass decreased from a preoperative value of 236 g to 96 g, 3 years after surgery. Only a few reports have described the use of the Konno operation in adult patients. In the present case, the Konno operation was demonstrated to be a good option for aortic stenosis accompanied by a small aortic annulus and a narrow left ventricular outflow tract, even in an elderly patient.

  20. Numerical Study of Laminar Forced Convection of Water/Al2o3 Nanofluid in an Annulus with Constant Wall Temperature

    Directory of Open Access Journals (Sweden)

    Amin Kashani

    2013-04-01

    Full Text Available Laminar forced convection of a nanofluid consisting of water and Al2O3 in a horizontal annulus has been studied numerically. Two-phase mixture model has been used to investigate thermal behaviors of the nanofluid over constant temperature thermal boundary condition and with different volume concentration of nanoparticles. Comparisons with previously published experimental and analytical works on flow behavior in horizontal annulus show good agreements between the results as volume fraction is zero. In general convective heat transfer coefficient increases with nanoparticle concentration. ABSTRAK: Kertaskerja ini mengkaji secara numerik olakan paksa bendalir lamina yang menganduangi air dan Al2O3 didalam anulus mendatar. Model campuran dua fasa digunakan bagi mengkaji tingkah laku haba bendalir nano pada keadaan suhu malar dengan kepekatan nanopartikel berbeza. Perbandingan dengan karya eksperimen dan analitikal yang telah diterbitkan menunjukkan bahawa kelakuan aliran didalm anulus mendatar adalah baik apabila pecahan isipadu adalah sifar. Pada amnya, pekali pemindahan haba olakan meningkat dengan kepekatan nanopartikel. KEYWORDS: nanofluid; volume concentration; heat transfer enhancement; laminar flow convection; annulus

  1. Protective effect of niacinamide on interleukin-1beta-induced annulus fibrosus type II collagen degeneration in vitro.

    Science.gov (United States)

    Duan, Deyu; Yang, Shuhua; Shao, Zengwu; Wang, Hong; Xiong, Xiaoqian

    2007-02-01

    The protective effect of niacinamide on interleukin-1beta (IL-1beta)-induced annulus fibrosus (AF) type II collagen degeneration in vitro and the mechanism were investigated. Chiba's intervertebral disc (IVD) culture models in rabbits were established and 48 IVDs from 12 adult Japanese white rabbits were randomly divided into 4 groups: normal control group, niacinamide-treated group, type II collagen degneration group (IL-1beta) and treatment group (niacinamide+IL-1beta). After culture for one week, AFs were collected for inducible nitric oxide synthase (iNOS), cysteine containing aspartate specific protease-3 (Caspase-3) and type II collagen immunohistochemical examination, and type II collagen reverse transcription polymerase chain reaction (RT-PCR). The results showed that rate of iNOS positive staining AF cells in the 4 groups was 17.6%, 10.9%, 73.9% and 19.3% respectively. The positive rate in treatment group was significantly lower than in the type II collagen degeneration group (Pniacinamide could effectively inhibit IL-1beta stimulated increase of iNOS and Caspase-3 in AF, and alleviate IL-1beta-caused destruction and synthesis inhibition of type II collagen. Niacinamide is of potential for clinical treatment of IVD degeneration.

  2. Inclusion of Zinc Oxide Nanoparticles into Virus-Like Peptide Nanocapsules Self-Assembled from Viral β-Annulus Peptide

    Directory of Open Access Journals (Sweden)

    Seiya Fujita

    2014-09-01

    Full Text Available A viral β-annulus peptide connected with a zinc oxide (ZnO-binding sequence (HCVAHR at its N-terminal was synthesized, and the inclusion behavior of quantum-sized ZnO nanoparticles into the peptide nanocapsules formed by self-assembly of the peptide in water was investigated. Dynamic light scattering (DLS measurements showed that ZnO nanoparticles (approximately 10 nm in the presence of the peptide (0.1 mM formed assemblies with an average size of 48 ± 24 nm, whereas ZnO nanoparticles in the absence of the peptide formed large aggregates. Transmission electron microscopy (TEM observations of the ZnO nanoparticles in the presence of the peptide revealed that ZnO nanoparticles were encapsulated into the peptide nanocapsules with a size of approximately 50 nm. Fluorescence spectra of a mixture of the peptide and ZnO nanoparticles suggested that the ZnO surface and the peptide interact. Template synthesis of ZnO nanoparticles with the peptide nanocapsules afforded larger nanoparticles (approximately 40 nm, which are not quantum-sized ZnO.

  3. Calculation Analysis of Pressure Wave Velocity in Gas and Drilling Mud Two-Phase Fluid in Annulus during Drilling Operations

    Directory of Open Access Journals (Sweden)

    Yuanhua Lin

    2013-01-01

    Full Text Available Investigation of propagation characteristics of a pressure wave is of great significance to the solution of the transient pressure problem caused by unsteady operations during management pressure drilling operations. With consideration of the important factors such as virtual mass force, drag force, angular frequency, gas influx rate, pressure, temperature, and well depth, a united wave velocity model has been proposed based on pressure gradient equations in drilling operations, gas-liquid two-fluid model, the gas-drilling mud equations of state, and small perturbation theory. Solved by adopting the Runge-Kutta method, calculation results indicate that the wave velocity and void fraction have different values with respect to well depth. In the annulus, the drop of pressure causes an increase in void fraction along the flow direction. The void fraction increases first slightly and then sharply; correspondingly the wave velocity first gradually decreases and then slightly increases. In general, the wave velocity tends to increase with the increase in back pressure and the decrease of gas influx rate and angular frequency, significantly in low range. Taking the virtual mass force into account, the dispersion characteristic of the pressure wave weakens obviously, especially at the position close to the wellhead.

  4. Comparison of phenotype characteristics of rat annulus fibrosus cells cultured on flexible silicone membrane and in plastic plate

    Institute of Scientific and Technical Information of China (English)

    GUO Zhi-liang; CHENG Min; CAO Guo-yong; LI Hua-zhuang; TENG Hai-jun; ZHOU Yue

    2006-01-01

    Objective:To compare the phenotype characteristics of rat annulus fibrosus (AF) cells cultured on flexible silicone membranes and those in plastic plates. Methods :The morphology of AF cells cultured in different substrates was examined. Proteoglycan was stained by toluidine blue. Contents of collagen type I , collagen type Ⅱ and aggrecan mRNAs were determined by reverse transcription-polymerase chain reaction (RT-PCR). The expression of integrin β1 was monitored by flow cytometry. By using propidium iodide (PI), the cell cycle in AF cells was analyzed. Cell adhesion to silicone membrane was also measured. Results:The AF cells cultured on different substrates were morphologically undistinguishable.Toluidine blue staining showed that there was also no difference between AF cells cultured on these 2 substrates. They still had the same expression levels of collagen type Ⅰ , collagen type Ⅱ , aggrecan mRNAs,and integrin β1. No significant difference was observed in the distribution of the cell cycle. AF cells grew well on silicone membrane. Conclusion:AF cells cultured on flexible silicone membrane maintain the stability of phenotype and may be appropriate for further studying the metabolic responses to mechanical stimuli at the cellular level.

  5. Self-assembly of aligned tissue-engineered annulus fibrosus and intervertebral disc composite via collagen gel contraction.

    Science.gov (United States)

    Bowles, Robby D; Williams, Rebecca M; Zipfel, Warren R; Bonassar, Lawrence J

    2010-04-01

    Many cartilaginous tissues such as intervertebral disc (IVD) display a heterogeneous collagen microstructure that results in mechanical anisotropy. These structures are responsible for mechanical function of the tissue and regulate cellular interactions and metabolic responses of cells embedded within these tissues. Using collagen gels seeded with ovine annulus fibrosus cells, constructs of varying structure and heterogeneity were created to mimic the circumferential alignment of the IVD. Alignment was induced within gels by contracting annular gels around an inner boundary using both a polyethylene center and alginate center to create a composite engineered IVD. Collagen alignment and heterogeneity were measured using second harmonic generation microscopy. Decreasing initial collagen density from 2.5 mg/mL to 1 mg/mL produced greater contraction of constructs, resulting in gels that were 55% and 6.2% of the original area after culture, respectively. As a result, more alignment occurred in annular-shaped 1 mg/mL gels compared with 2.5 mg/mL gels (p < 0.05). This alignment was also produced in a composite-engineered IVD with alginate nucleus pulposus. The resulting collagen alignment could promote further aligned collagen development necessary for the creation of a mechanically functional tissue-engineered IVD.

  6. Transient critical heat flux under flow coast-down in vertical annulus with non-uniform heat flux distribution

    Energy Technology Data Exchange (ETDEWEB)

    Moon, S.K.; Chun, S.Y.; Choi, K.Y.; Yang, S.K. [Korea Atomic Energy Research Inst., Taejon (Korea, Republic of)

    2001-07-01

    An experimental study on transient critical heat flux (CHF) under flow coast-down has been performed for water flow in a non-uniformly heated vertical annulus under low flow and a wide range of pressure conditions. The objectives of this study are to systematically investigate the effect of the flow transient on the CHF and to compare the transient CHF with steady state CHF. The transient CHF experiments have been performed for three kinds of flow transient modes based on the coast-down data of the Kori 3/4 nuclear power plant reactor coolant pump. Most of the CHFs occurred in the annular-mist flow regime. Thus, it means that the possible CHF mechanism might be the liquid film dryout in the annular-mist flow regime. For flow transient mode with the smallest flow reduction rate, the time-to-CHF is the largest. At the same inlet subcooling, system pressure and heat flux, the effect of the initial mass flux on the critical mass flux can be negligible. However, the effect of the initial mass flux on the time-to-CHF becomes large as the heat flux decreases. Usually, the critical mass flux is large for slow flow reduction. There is a pressure effect on the ratio of the transient CHF data to steady state CHF data. Some conventional correlations show relatively better CHF prediction results for high system pressure, high quality and slow transient modes than for low system pressure, low quality and fast transient modes. (author)

  7. A Novel Dynamic Model for Predicting Pressure Wave Velocity in Four-Phase Fluid Flowing along the Drilling Annulus

    Directory of Open Access Journals (Sweden)

    Xiangwei Kong

    2015-01-01

    Full Text Available A dynamic pressure wave velocity model is presented based on momentum equation, mass-balance equation, equation of state, and small perturbation theory. Simultaneously, the drift model was used to analyze the flow characteristics of oil, gas, water, and drilling fluid multiphase flow. In addition, the dynamic model considers the gas dissolution, virtual mass force, drag force, and relative motion of the interphase as well. Finite difference and Newton-Raphson iterative are introduced to the numerical simulation of the dynamic model. The calculation results indicate that the wave velocity is more sensitive to the increase of gas influx rate than the increase of oil/water influx rate. Wave velocity decreases significantly with the increase of gas influx. Influenced by the pressure drop of four-phase fluid flowing along the annulus, wave velocity tends to increase with respect to well depth, contrary to the gradual reduction of gas void fraction at different depths with the increase of backpressure (BP. Analysis also found that the growth of angular frequency will lead to an increase of wave velocity at low range. Comparison with the calculation results without considering virtual mass force demonstrates that the calculated wave velocity is relatively bigger by using the presented model.

  8. A comparison between porcine, ovine, and bovine intervertebral disc anatomy and single lamella annulus fibrosus tensile properties.

    Science.gov (United States)

    Monaco, Lauren A; DeWitte-Orr, Stephanie J; Gregory, Diane E

    2016-02-01

    This project aimed to compare gross anatomical measures and biomechanical properties of single lamellae from the annulus fibrosus of ovine and porcine lumbar vertebrae, and bovine tail vertebrae. The morphology of the vertebrae of these species differ significantly both from each other and from human, yet how these differences alter biomechanical properties is unknown. Geometric parameters measured in this study included: 1) absolute and relative intervertebral (IVD) and vertebral body height and 2) absolute and relative intervertebral disc (IVD) anterior-posterior (AP) and medial-lateral (ML) widths. Single lamella tensile properties included toe-region stress and stretch ratio, stiffness, and tensile strength. As expected, the bovine tail IVD revealed a more circular shape compared with both the ovine and porcine lumbar IVD. The bovine tail also had the largest IVD to vertebral body height ratio (due to having the highest absolute IVD height). Bovine tail lamellae were also found to be strongest and stiffest (in tension) while ovine lumbar lamellae were weakest and most compliant. Histological analysis revealed the greatest proportion of collagen in the bovine corroborating findings of increased strength and stiffness. The observed differences in anatomical shape, connective tissue composition, and tensile properties need to be considered when choosing an appropriate model for IVD research.

  9. Structure and mechanical function of the inter-lamellar matrix of the annulus fibrosus in the disc.

    Science.gov (United States)

    Tavakoli, Javad; Elliott, Dawn M; Costi, John J

    2016-08-01

    The inter-lamellar matrix (ILM) has an average thickness of less than 30 µm and lies between adjacent lamellae in the annulus fibrosus (AF). The microstructure and composition of the ILM have been studied in various anatomic regions of the disc; however, their contribution to AF mechanical properties and structural integrity is unknown. It was suggested that the ILM components, mainly elastic fibers and cross-bridges, play a role in providing mechanical integrity of the AF. Therefore, the manner in which they respond to different loadings and stabilize adjacent lamellae structure will influence AF tear formation and subsequent herniation. This review paper summarizes the composition, microstructure, and potential role of the ILM in the progression of disc herniation, clarifies the micromechanical properties of the ILM, and proposes critical areas for future studies. There are a number of unknown characteristics of the ILM, such as its mechanical role, impact on AF integrity, and ultrastructure of elastic fibers at the ILM-lamella boundary. Determining these characteristics will provide important information for tissue engineering, repair strategies, and the development of more-physiological computational models to study the initiation and propagation of AF tears that lead to herniation and degeneration. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1307-1315, 2016.

  10. Report for the HWMA/RCRA Post Closure Permit for the INTEC Waste Calcining Facility at the INL Site

    Energy Technology Data Exchange (ETDEWEB)

    Idaho Cleanup Project

    2006-06-01

    The Waste Calcining Facility (WCF) is located at the Idaho Nuclear Technology and Engineering Center. In 1998, the WCF was closed under an approved Hazardous Waste Management Act/Resource Conservation and Recovery Act (HWMA/RCRA) Closure Plan. Vessels and spaces were grouted and then covered with a concrete cap. The Idaho Department of Environmental Quality issued a final HWMA/RCRA post-closure permit on September 15, 2003, with an effective date of October 16, 2003. This permit sets forth procedural requirements for groundwater characterization and monitoring, maintenance, and inspections of the WCF to ensure continued protection of human health and the environment. The post-closure permit also includes semiannual reporting requirements under Permit Conditions III.H. and I.U. These reporting requirements have been combined into this single semiannual report.

  11. Vascular Closure Devices in Interventional Radiology Practice.

    Science.gov (United States)

    Patel, Rafiuddin; Muller-Hulsbeck, Stefan; Morgan, Robert; Uberoi, Raman

    2015-08-01

    Manual compression (MC) is a well-established technique for haemostasis following percutaneous arterial intervention. However, MC is labour and time intensive with potential limitations, particularly for patients who are coagulopathic, unable to comply with bed rest or obese and when large sheaths or anti-coagulants are used. There are a variety of vascular closure devices (VCDs) available to overcome these limitations. This review gives an overview of current VCDs, their mechanism of action, individual strengths and weaknesses, evidence base and utility in interventional radiology (IR) practice. The majority of the published evidence on VCDs is derived from patients undergoing cardiac interventions, which should be borne in mind when considering the applicability and transfer of this data for general IR practice. Overall, the evidence suggests that most VCDs are effective in achieving haemostasis with a similar rate of complications to MC although the complication profile associated with VCDs is distinct to that of MC. There is insufficient evidence to comparatively analyse the different types of VCDs currently available or reliably judge their cost-effectiveness. The interventional radiologist should have a thorough understanding of the available techniques for haemostasis and be able to identify and utilise the most appropriate strategy and closure technique for the individual patient.

  12. Distributed Programming via Safe Closure Passing

    Directory of Open Access Journals (Sweden)

    Philipp Haller

    2016-02-01

    Full Text Available Programming systems incorporating aspects of functional programming, e.g., higher-order functions, are becoming increasingly popular for large-scale distributed programming. New frameworks such as Apache Spark leverage functional techniques to provide high-level, declarative APIs for in-memory data analytics, often outperforming traditional "big data" frameworks like Hadoop MapReduce. However, widely-used programming models remain rather ad-hoc; aspects such as implementation trade-offs, static typing, and semantics are not yet well-understood. We present a new asynchronous programming model that has at its core several principles facilitating functional processing of distributed data. The emphasis of our model is on simplicity, performance, and expressiveness. The primary means of communication is by passing functions (closures to distributed, immutable data. To ensure safe and efficient distribution of closures, our model leverages both syntactic and type-based restrictions. We report on a prototype implementation in Scala. Finally, we present preliminary experimental results evaluating the performance impact of a static, type-based optimization of serialization.

  13. IT SERVICES AVAILABILITY DURING CERN ANNUAL CLOSURE

    CERN Multimedia

    2002-01-01

    Mail, NICE 2000, Web, EDMS (in collaboration with EST Division), General purpose databases, lxbatch, lxplus, Automated tape devices, Castor, Backups, Campus Network, Remedy, Security and VPN services will be available during the CERN annual closure. Problems developing on these services should be addressed within about half a day except on Christmas and New Year evenings, December 25, 2002 and January 1st, 2003. All other services will be left running mostly unattended. No interruptions are scheduled but restoration of the service in case of failure cannot be guaranteed. It should be noted that the Helpdesk will be closed, that no file restores from backups will be possible and damaged tapes will not be processed. An operator service will be maintained and can be reached at extension 75011 or by email to computer.operations@cern.ch. Please remember to shutdown and power off any equipment in your office which is not foreseen to be used during the annual closure before you leave for the holiday.

  14. Vascular Closure Devices in Interventional Radiology Practice

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Rafiuddin, E-mail: rafiuddin.patel@ouh.nhs.uk [John Radcliffe Hospital, Department of Radiology (United Kingdom); Muller-Hulsbeck, Stefan, E-mail: muehue@diako.de [Diakonissen Hospital, Diagnostic and Interventional Radiology/Neuroradiology (Germany); Morgan, Robert, E-mail: robert.morgan@stgeorges.nhs.uk [St George’s Hospital, Department of Radiology (United Kingdom); Uberoi, Raman, E-mail: raman.uberoi@orh.nhs.uk [John Radcliffe Hospital, Department of Radiology (United Kingdom)

    2015-08-15

    Manual compression (MC) is a well-established technique for haemostasis following percutaneous arterial intervention. However, MC is labour and time intensive with potential limitations, particularly for patients who are coagulopathic, unable to comply with bed rest or obese and when large sheaths or anti-coagulants are used. There are a variety of vascular closure devices (VCDs) available to overcome these limitations. This review gives an overview of current VCDs, their mechanism of action, individual strengths and weaknesses, evidence base and utility in interventional radiology (IR) practice. The majority of the published evidence on VCDs is derived from patients undergoing cardiac interventions, which should be borne in mind when considering the applicability and transfer of this data for general IR practice. Overall, the evidence suggests that most VCDs are effective in achieving haemostasis with a similar rate of complications to MC although the complication profile associated with VCDs is distinct to that of MC. There is insufficient evidence to comparatively analyse the different types of VCDs currently available or reliably judge their cost-effectiveness. The interventional radiologist should have a thorough understanding of the available techniques for haemostasis and be able to identify and utilise the most appropriate strategy and closure technique for the individual patient.

  15. On closure parameter estimation in chaotic systems

    Directory of Open Access Journals (Sweden)

    J. Hakkarainen

    2012-02-01

    Full Text Available Many dynamical models, such as numerical weather prediction and climate models, contain so called closure parameters. These parameters usually appear in physical parameterizations of sub-grid scale processes, and they act as "tuning handles" of the models. Currently, the values of these parameters are specified mostly manually, but the increasing complexity of the models calls for more algorithmic ways to perform the tuning. Traditionally, parameters of dynamical systems are estimated by directly comparing the model simulations to observed data using, for instance, a least squares approach. However, if the models are chaotic, the classical approach can be ineffective, since small errors in the initial conditions can lead to large, unpredictable deviations from the observations. In this paper, we study numerical methods available for estimating closure parameters in chaotic models. We discuss three techniques: off-line likelihood calculations using filtering methods, the state augmentation method, and the approach that utilizes summary statistics from long model simulations. The properties of the methods are studied using a modified version of the Lorenz 95 system, where the effect of fast variables are described using a simple parameterization.

  16. Closure Plan for the Area 3 Radioactive Waste Management Site at the Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Management

    2007-09-01

    The Area 3 Radioactive Waste Management Site (RMWS) at the Nevada Test Site (NTS) is managed and operated by National Security Technologies, LLC (NSTec) for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO). This document is the first update of the interim closure plan for the Area 3 RWMS, which was presented in the Integrated Closure and Monitoring Plan (ICMP) (DOE, 2005). The format and content of this plan follows the Format and Content Guide for U.S. Department of Energy Low-Level Waste Disposal Facility Closure Plans (DOE, 1999a). The major updates to the plan include a new closure date, updated closure inventory, the new institutional control policy, and the Title II engineering cover design. The plan identifies the assumptions and regulatory requirements, describes the disposal sites and the physical environment in which they are located, presents the design of the closure cover, and defines the approach and schedule for both closing and monitoring the site. The Area 3 RWMS accepts low-level waste (LLW) from across the DOE Complex in compliance with the NTS Waste Acceptance Criteria (NNSA/NSO, 2006). The Area 3 RWMS accepts both packaged and unpackaged unclassified bulk LLW for disposal in subsidence craters that resulted from deep underground tests of nuclear devices in the early 1960s. The Area 3 RWMS covers 48 hectares (119 acres) and comprises seven subsidence craters--U-3ax, U-3bl, U-3ah, U-3at, U-3bh, U-3az, and U-3bg. The area between craters U-3ax and U-3bl was excavated to form one large disposal unit (U-3ax/bl); the area between craters U-3ah and U-3at was also excavated to form another large disposal unit (U-3ah/at). Waste unit U-3ax/bl is closed; waste units U-3ah/at and U-3bh are active; and the remaining craters, although currently undeveloped, are available for disposal of waste if required. This plan specifically addresses the closure of the U-3ah/at and the U-3bh LLW units. A final closure

  17. 77 FR 55895 - Permanent Closure of Cincinnati Blue Ash Airport

    Science.gov (United States)

    2012-09-11

    ... Federal Aviation Administration Permanent Closure of Cincinnati Blue Ash Airport AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of permanent closure of Cincinnati Blue Ash Airport (ISZ). SUMMARY: The... Cincinnati advising that on August 29, 2012, it was permanently closing Cincinnati Blue Ash Airport...

  18. The use of paper tape in wound closures.

    Science.gov (United States)

    Danto, L A; Albertazzi, V J; Elliott, T E; Love, F G

    1986-12-01

    The techniques described using paper tape in wound closure have been found to be cosmetically equal to or better than other forms of wound closure. Paper tape provides better support, is more versatile and care free, while being easier to use and less expensive than Steri Strips.

  19. Managing waste exports when closure risks are endogenous

    OpenAIRE

    Stähler, Frank; Michaelis, Peter

    1993-01-01

    This paper provides a rationale for taxing waste exports when closure risks are endogenous in that they depend on the importing country's accumulated stock of waste. The paper shows that the optimal time path of waste exports requires a progressively increasing tax rate which even surmounts a Hotelling tax which tackles the problem by evaluating the expected closure stock.

  20. 30 CFR 57.4603 - Closure of valves.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Closure of valves. 57.4603 Section 57.4603... Control Welding/cutting/compressed Gases § 57.4603 Closure of valves. To prevent accidental release of... or manifold system valves shall be closed when— (a) The cylinders are moved; (b) The torch and...

  1. 30 CFR 56.4603 - Closure of valves.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Closure of valves. 56.4603 Section 56.4603... Control Welding/cutting/compressed Gases § 56.4603 Closure of valves. To prevent accidental release of... or manifold system valves shall be closed when— (a) The cylinders are moved; (b) The torch and...

  2. On the normality of orbit closures which are hypersurfaces

    Indian Academy of Sciences (India)

    Nguyen Quang Loc

    2016-02-01

    Let be a quiver representation with non-zero admissible annihilator. In this paper, we prove the normality of the orbit closure $\\bar{\\mathcal{O}}_{N}$ when it is a hypersurface. The result thus gives new examples of normal orbit closures of quiver representations.

  3. Biomechanics Strategies for Space Closure in Deep Overbite

    Directory of Open Access Journals (Sweden)

    Harryanto Wijaya

    2013-07-01

    Full Text Available Space closure is an interesting aspect of orthodontic treatment related to principles of biomechanics. It should be tailored individually based on patient’s diagnosis and treatment plan. Understanding the space closure biomechanics basis leads to achieve the desired treatment objective. Overbite deepening and losing posterior anchorage are the two most common unwanted side effects in space closure. Conventionally, correction of overbite must be done before space closure resulted in longer treatment. Application of proper space closure biomechanics strategies is necessary to achieve the desired treatment outcome. This cases report aimed to show the space closure biomechanics strategies that effectively control the overbite as well as posterior anchorage in deep overbite patients without increasing treatment time. Two patients who presented with class II division 1 malocclusion were treated with fixed orthodontic appliance. The primary strategies included extraction space closure on segmented arch that employed two-step space closure, namely single canine retraction simultaneously with incisors intrusion followed by enmasse retraction of four incisors by using differential moment concept. These strategies successfully closed the space, corrected deep overbite and controlled posterior anchorage simultaneously so that the treatment time was shortened. Biomechanics strategies that utilized were effective to achieve the desired treatment outcome.

  4. Localization of Tight Closure in Two-Dimensional Rings

    Indian Academy of Sciences (India)

    Kamran Divaani-Aazar; Massoud Tousi

    2005-02-01

    It is shown that tight closure commutes with localization in any two-dimensional ring of prime characteristic if either is a Nagata ring or possesses a weak test element. Moreover, it is proved that tight closure commutes with localization at height one prime ideals in any ring of prime characteristic.

  5. 40 CFR 267.142 - Cost estimate for closure.

    Science.gov (United States)

    2010-07-01

    ... dollars, or by using an inflation factor derived from the most recent Implicit Price Deflator for Gross... active life of the facility, the owner or operator must adjust the closure cost estimate for inflation... closure cost estimate must be updated for inflation within 30 days after the close of the firm's fiscal...

  6. WASTE PACKAGE OPERATIONS FY99 CLOSURE METHODS REPORT

    Energy Technology Data Exchange (ETDEWEB)

    M. C. Knapp

    1999-09-23

    The waste package (WP) closure weld development task is part of a larger engineering development program to develop waste package designs. The purpose of the larger waste package engineering development program is to develop nuclear waste package fabrication and closure methods that the Nuclear Regulatory Commission will find acceptable and will license for disposal of spent nuclear fuel (SNF), non-fuel components, and vitrified high-level waste within a Monitored Geologic Repository (MGR). Within the WP closure development program are several major development tasks, which, in turn, are divided into subtasks. The major tasks include: WP fabrication development, WP closure weld development, nondestructive examination (NDE) development, and remote in-service inspection development. The purpose of this report is to present the objectives, technical information, and work scope relating to the WP closure weld development.and NDE tasks and subtasks and to report results of the closure weld and NDE development programs for fiscal year 1999 (FY-99). The objective of the FY-99 WP closure weld development task was to develop requirements for closure weld surface and volumetric NDE performance demonstrations, investigate alternative NDE inspection techniques, and develop specifications for welding, NDE, and handling system integration. In addition, objectives included fabricating several flat plate mock-ups that could be used for NDE development, stress relief peening, corrosion testing, and residual stress testing.

  7. Guinea pig ductus arteriosus. II - Irreversible closure after birth.

    Science.gov (United States)

    Fay, F. S.; Cooke, P. H.

    1972-01-01

    To investigate the mechanism underlying irreversibility of ductal closure after birth, studies were undertaken to determine the exact time course for the onset of irreversible closure of the guinea pig ductus arteriosus. Parallel studies of the reactivity of ductal smooth muscle to oxygen and studies of the postpartum cellular changes within the vessel were also carried out.

  8. Fatigue Crack Closure Analysis Using Digital Image Correlation

    Science.gov (United States)

    Leser, William P.; Newman, John A.; Johnston, William M.

    2010-01-01

    Fatigue crack closure during crack growth testing is analyzed in order to evaluate the critieria of ASTM Standard E647 for measurement of fatigue crack growth rates. Of specific concern is remote closure, which occurs away from the crack tip and is a product of the load history during crack-driving-force-reduction fatigue crack growth testing. Crack closure behavior is characterized using relative displacements determined from a series of high-magnification digital images acquired as the crack is loaded. Changes in the relative displacements of features on opposite sides of the crack are used to generate crack closure data as a function of crack wake position. For the results presented in this paper, remote closure did not affect fatigue crack growth rate measurements when ASTM Standard E647 was strictly followed and only became a problem when testing parameters (e.g., load shed rate, initial crack driving force, etc.) greatly exceeded the guidelines of the accepted standard.

  9. On Conservation Equation Combinations and Closure Relations

    Directory of Open Access Journals (Sweden)

    William G. Gray

    2014-07-01

    Full Text Available Fundamental conservation equations for mass, momentum and energy of chemical species can be combined with thermodynamic relations to obtain secondary forms, such as conservation equations for phases, an internal energy balance and a mechanical energy balance. In fact, the forms of secondary equations are infinite and depend on the criteria used in determining which species-based equations to employ and how to combine them. If one uses these secondary forms in developing an entropy inequality to be used in formulating closure relations, care must be employed to ensure that the appropriate equations are used, or problematic results can develop for multispecies systems. We show here that the use of the fundamental forms minimizes the chance of an erroneous formulation in terms of secondary forms and also provides guidance as to which secondary forms should be used if one uses them as a starting point.

  10. Occupational closure in nursing work reconsidered

    DEFF Research Database (Denmark)

    Traynor, Michael; Nissen, Nina; Lincoln, Carol

    2015-01-01

    In healthcare, occupational groups have adopted tactics to maintain autonomy and control over their areas of work. Witz described a credentialist approach to occupational closure adopted by nursing in the United Kingdom during the 19th and early 20th centuries. However, the recent advancement...... = 59). The aim was to examine how these workers positioned themselves as professionals and accounted for professional boundaries. A thematic analysis revealed a complex situation in which participants were divided between articulating an acceptance of a subordinate role within traditional occupational......, while nurses abandon it for largely administrative roles. We conclude that the participants are the not unwilling agents of a managerially led project to reshape the workforce that cuts across existing occupational boundaries....

  11. Asymptotic Behavior of Integral Closures in Modules

    Institute of Scientific and Technical Information of China (English)

    R.Naghipour; P.Schenzel

    2007-01-01

    Let R be a commutative Noetherian Nagata ring,let M be a non-zero finitely generated R-module,and let I be an ideal of R such that height M I > O.In this paper,there is a definition of the integral closure Na for any submodule N of M extending Rees'definition for the case of a domain.As the main results,it is shown that the operation N →Na on the set of submodules N of M is a semi-prime operation,and for any submodule Nof M,the sequences Ass R M/(InN)a and hssR(InM)a/(InN)a (n=1,2,...) of associated prime ideals are increasing and ultimately constant for large n.

  12. Notice of car park and road closures

    CERN Multimedia

    2006-01-01

    The transfer of the two HF CMS detectors between Hall 186 and Point 5 (a convoy measuring 64 metres in length and weighing 440 tonnes) will result in the temporary closure of the following car parks: Building186: south entrance Building 613 Building 28 Building181 south entrance Building 600 Building 31 Route OPPENHEIMER The car parks concerned will be closed from Sunday 2 July until the evening of Tuesday 4 July and from Sunday 9 July until the evening of Tuesday 11 July 2006. Route FEYNMAN is also expected to be closed to traffic from mid-morning on Monday 3 July until the evening of Tuesday 4 July and from mid-morning on Monday 10 July until the evening of Tuesday 11 July (possible deviation via route FERMI and route RUTHERFORD). Thank you for your cooperation. TS-IC Group Tel. 163380 - 164043

  13. Notice of car park and road closures

    CERN Multimedia

    2006-01-01

    The transfer of the two HF CMS detectors between Hall 186 and Point 5 (a convoy measuring 64 metres in length and weighing 440 tonnes) will result in the temporary closure of the following car parks: Building186: south entrance Building 613 Building 28 Building181 south entrance Building 600 Building 31 Route OPPENHEIMER The car parks concerned will be closed from Sunday 2 July until the evening of Tuesday 4 July and from Sunday 9 July until the evening of Tuesday 11 July 2006.Route FEYNMAN is also expected to be closed to traffic from mid-morning on Monday 3 July until the evening of Tuesday 4 July and from mid-morning on Monday 10 July until the evening of Tuesday 11 July (possible deviation via route FERMI and route RUTHERFORD).Thank you for your cooperation. TS-IC GroupTel. 163380 - 164043

  14. Spontaneous closure of midline diastema following frenectomy

    Directory of Open Access Journals (Sweden)

    Koora Kiran

    2007-03-01

    Full Text Available Maxillary midline diastema is a common aesthetic problem in mixed and early permanent dentitions. The space can occur either as a transient malocclusion or created by developmental, pathological or iatrogenical factors. Many innovative therapies varying from restorative procedures such as composite build-up to surgery (frenectomies and orthodontics are available. Although literature says every frenectomy procedure should be preceded by orthodontic treatment, we opted for frenectomy technique without any orthodontic intervention. Presented herewith is a case report of a 9-year-old girl with a high frenal attachment that had caused spacing of the maxillary central incisors. A spontaneous closure of the midline diastema was noted within 2 months following frenectomy. The patient was followed up for 4 months after which the space remained closed and there was no necessity for an orthodontic treatment at a later stage.

  15. Spontaneous closure of midline diastema following frenectomy.

    Science.gov (United States)

    Koora, Kiran; Muthu, M S; Rathna, Prabhu V

    2007-03-01

    Maxillary midline diastema is a common aesthetic problem in mixed and early permanent dentitions. The space can occur either as a transient malocclusion or created by developmental, pathological or iatrogenical factors. Many innovative therapies varying from restorative procedures such as composite build-up to surgery (frenectomies) and orthodontics are available. Although literature says every frenectomy procedure should be preceded by orthodontic treatment, we opted for frenectomy technique without any orthodontic intervention. Presented herewith is a case report of a 9-year-old girl with a high frenal attachment that had caused spacing of the maxillary central incisors. A spontaneous closure of the midline diastema was noted within 2 months following frenectomy. The patient was followed up for 4 months after which the space remained closed and there was no necessity for an orthodontic treatment at a later stage.

  16. Dynamics of electrochemical flows 3 Closure models

    CERN Document Server

    Xu, Chengjun

    2013-01-01

    The electrolyte (comprising of solute ions and solvents) flow-through the porous media is frequently encountered in nature or in many engineering applications, such as the electrochemical systems, manufacturing of composites, oil production, geothermal engineering, nuclear thermal disposal, soil pollution. Our previous work derived the interfacial interaction terms between the solid and the fluid, which can be used to investigate the details of transports of mass, heat, electric flied, potential, or momentum in the process of the electrochemical flows-through porous electrode. In this work, we establish the closure models for these interfacial interaction terms to close the governing equations from mathematical algebra. The interfacial interaction terms regard to the electric field, potential and electric force are firstly revealed. Our new theory provides a new approach to describe the electrochemical flows-through porous media.

  17. ICPP tank farm closure study. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Spaulding, B.C.; Gavalya, R.A.; Dahlmeir, M.M. [and others

    1998-02-01

    The disposition of INEEL radioactive wastes is now under a Settlement Agreement between the DOE and the State of Idaho. The Settlement Agreement requires that existing liquid sodium bearing waste (SBW), and other liquid waste inventories be treated by December 31, 2012. This agreement also requires that all HLW, including calcined waste, be disposed or made road ready to ship from the INEEL by 2035. Sodium bearing waste (SBW) is produced from decontamination operations and HLW from reprocessing of SNF. SBW and HLW are radioactive and hazardous mixed waste; the radioactive constituents are regulated by DOE and the hazardous constituents are regulated by the Resource Conservation and Recovery Act (RCRA). Calcined waste, a dry granular material, is produced in the New Waste Calcining Facility (NWCF). Two primary waste tank storage locations exist at the ICPP: Tank Farm Facility (TFF) and the Calcined Solids Storage Facility (CSSF). The TFF has the following underground storage tanks: four 18,400-gallon tanks (WM 100-102, WL 101); four 30,000-gallon tanks (WM 103-106); and eleven 300,000+ gallon tanks. This includes nine 300,000-gallon tanks (WM 182-190) and two 318,000 gallon tanks (WM 180-181). This study analyzes the closure and subsequent use of the eleven 300,000+ gallon tanks. The 18,400 and 30,000-gallon tanks were not included in the work scope and will be closed as a separate activity. This study was conducted to support the HLW Environmental Impact Statement (EIS) waste separations options and addresses closure of the 300,000-gallon liquid waste storage tanks and subsequent tank void uses. A figure provides a diagram estimating how the TFF could be used as part of the separations options. Other possible TFF uses are also discussed in this study.

  18. Do mechanical strain and TNF-α interact to amplify pro-inflammatory cytokine production in human annulus fibrosus cells?

    Science.gov (United States)

    Likhitpanichkul, Morakot; Torre, Olivia M; Gruen, Jadry; Walter, Benjamin A; Hecht, Andrew C; Iatridis, James C

    2016-05-03

    During intervertebral disc (IVD) injury and degeneration, annulus fibrosus (AF) cells experience large mechanical strains in a pro-inflammatory milieu. We hypothesized that TNF-α, an initiator of IVD inflammation, modifies AF cell mechanobiology via cytoskeletal changes, and interacts with mechanical strain to enhance pro-inflammatory cytokine production. Human AF cells (N=5, Thompson grades 2-4) were stretched uniaxially on collagen-I coated chambers to 0%, 5% (physiological) or 15% (pathologic) strains at 0.5Hz for 24h under hypoxic conditions with or without TNF-α (10ng/mL). AF cells were treated with anti-TNF-α and anti-IL-6. ELISA assessed IL-1β, IL-6, and IL-8 production and immunocytochemistry measured F-actin, vinculin and α-tubulin in AF cells. TNF-α significantly increased AF cell pro-inflammatory cytokine production compared to basal conditions (IL-1β:2.0±1.4-84.0±77.3, IL-6:10.6±9.9-280.9±214.1, IL-8:23.9±26.0-5125.1±4170.8pg/ml for basal and TNF-α treatment, respectively) as expected, but mechanical strain did not. Pathologic strain in combination with TNF-α increased IL-1β, and IL-8 but not IL-6 production of AF cells. TNF-α treatment altered F-actin and α-tubulin in AF cells, suggestive of altered cytoskeletal stiffness. Anti-TNF-α (infliximab) significantly inhibited pro-inflammatory cytokine production while anti-IL-6 (atlizumab) did not. In conclusion, TNF-α altered AF cell mechanobiology with cytoskeletal remodeling that potentially sensitized AF cells to mechanical strain and increased TNF-α-induced pro-inflammatory cytokine production. Results suggest an interaction between TNF-α and mechanical strain and future mechanistic studies are required to validate these observations.

  19. Beta1 integrin inhibits apoptosis induced by cyclic stretch in annulus fibrosus cells via ERK1/2 MAPK pathway.

    Science.gov (United States)

    Zhang, Kai; Ding, Wei; Sun, Wei; Sun, Xiao-jiang; Xie, You-zhuan; Zhao, Chang-qing; Zhao, Jie

    2016-01-01

    Low back pain is associated with intervertebral disc degeneration (IVDD) due to cellular loss through apoptosis. Mechanical factors play an important role in maintaining the survival of the annulus fibrosus (AF) cells and the deposition of extracellular matrix. However, the mechanisms that excessive mechanical forces lead to AF cell apoptosis are not clear. The present study was to look for how AF cells sense mechanical changes. In vivo experiments, the involvement of mechanoreceptors in apoptosis was examined by RT-PCR and/or immunoblotting in the lumbar spine of rats subjected to unbalanced dynamic and static forces. In vitro experiments, we investigated apoptotic signaling pathways in untransfected and transfected AF cells with the lentivirus vector for rat β1 integrin overexpression after cyclic stretch. Apoptosis in AF cells was assessed using flow cytometry, Hoechst 33258 nuclear staining. Western blotting was used to analyze expression of β1 integrin and caspase-3 and ERK1/2 MAPK signaling molecules. In the rat IVDD model, unbalanced dynamic and static forces induced apoptosis of disc cells, which corresponded to decreased expression of β1 integrin. Cyclic stretch-induced apoptosis in rat AF cells correlated with the activation of caspase-3 and with decreased levels of β1 integrin and the phosphorylation levels of ERK1/2 activation level. However, the overexpression of β1 integrin in AF cells ameliorated cyclic stretch-induced apoptosis and decreased caspase-3 activation. Furthermore, ERK1/2-specific inhibitor promotes apoptosis in vector β1-infected AF cells. These results suggest that the disruption of β1 integrin signaling may underlie disc cell apoptosis induced by mechanical stress. Further work is necessary to fully elucidate the pathophysiological mechanisms that underlie IVDD caused by unbalanced dynamic and static forces.

  20. Formation of lamellar cross bridges in the annulus fibrosus of the intervertebral disc is a consequence of vascular regression.

    Science.gov (United States)

    Smith, Lachlan J; Elliott, Dawn M

    2011-05-01

    Cross bridges are radial structures within the highly organized lamellar structure of the annulus fibrosus of the intervertebral disc that connect two or more non-consecutive lamellae. Their origin and function are unknown. During fetal development, blood vessels penetrate deep within the AF and recede during postnatal growth. We hypothesized that cross bridges are the pathways left by these receding blood vessels. Initially, the presence of cross bridges was confirmed in cadaveric human discs aged 25 and 53 years. Next, L1-L2 intervertebral discs (n=4) from sheep ranging in age from 75 days fetal gestation to adult were processed for paraffin histology. Mid-sagittal sections were immunostained for endothelial cell marker PECAM-1. The anterior and posterior AF were imaged using differential interference contrast microscopy, and the following parameters were quantified: total number of distinct lamellae, total number of cross bridges, percentage of cross bridges staining positive for PECAM-1, cross bridge penetration depth (% total lamellae), and PECAM-1 positive cross bridge penetration depth. Cross bridges were first observed at 100 days fetal gestation. The overall number peaked in neonates then remained relatively unchanged. The percentage of PECAM-1 positive cross bridges declined progressively from almost 100% at 100 days gestation to less than 10% in adults. Cross bridge penetration depth peaked in neonates then remained unchanged at subsequent ages. Depth of PECAM-1 positive cross bridges decreased progressively after birth. Findings were similar for both the anterior and posterior. The AF lamellar architecture is established early in development. It later becomes disrupted as a consequence of vascularization. Blood vessels then recede, perhaps due to increasing mechanical stresses in the surrounding matrix. In this study we present evidence that the pathways left by receding blood vessels remain as lamellar cross bridges. It is unclear whether the presence

  1. Aortic annulus dimension assessment by computed tomography for transcatheter aortic valve implantation: differences between systole and diastole.

    Science.gov (United States)

    Bertaso, Angela G; Wong, Dennis T L; Liew, Gary Y H; Cunnington, Michael S; Richardson, James D; Thomson, Viji S; Lorraine, Brett; Kourlis, George; Leech, Diana; Worthley, Matthew I; Worthley, Stephen G

    2012-12-01

    Accurate assessment of aortic annular dimensions is essential for successful transcatheter aortic valve implantation (TAVI). Annular dimensions are conventionally measured in mid-systole by multidetector computed tomography (MDCT), echocardiography and angiography. Significant differences in systolic and diastolic aortic annular dimensions have been demonstrated in cohorts without aortic stenosis (AS), but it is unknown whether similar dynamic variation in annular dimensions exists in patients with severe calcific AS in whom aortic compliance is likely to be substantially reduced. We investigated the variation in aortic annular dimensions between systole and diastole in patients with severe calcific AS. Patients with severe calcific AS referred for TAVI were evaluated by 128-slice MDCT. Aortic annular diameter was measured during diastole and systole in the modified coronal, modified sagittal, and basal ring planes (maximal, minimal and mean diameters). Differences between systole and diastole were analysed by paired t test. Fifty-nine patients were included in the analysis. Three of the five aortic dimensions measured increased significantly during systole. The largest change was a 0.75 mm (3.4%) mean increase in the minimal diameter of the basal ring during systole (p = 0.004). This corresponds closely to the modified sagittal view, which also increased by mean 0.42 mm (1.9%) during systole (p = 0.008). There was no significant change in the maximal diameter of the basal ring or the modified coronal view during systole (p > 0.05). There is a small magnitude but statistically significant difference in aortic annulus dimensions of patients with severe AS referred for TAVI when measured in diastole and systole. This small difference is unlikely to alter clinical decisions regarding prosthesis size or suitability for TAVI.

  2. Protective Effect of Niacinamide on interleukin-1β-induced Annulus Fibrosus Type Ⅱ Collagen Degeneration in vitro

    Institute of Scientific and Technical Information of China (English)

    DUAN Deyu; YANG Shuhua; SHAO Zengwu; WANG Hong; XIONG Xiaoqian

    2007-01-01

    The protective effect of niacinamide on interleukin-1β (IL-1β)-induced annulus fibrosus (AF) type Ⅱ collagen degeneration in vitro and the mechanism were investigated. Chiba's intervertebrai disc (IVD) culture models in rabbits were established and 48 IVDs from 12 adult Japanese white rabbits were randomly divided into 4 groups: normal control group, niacinamide-treated group, type Ⅱ collagen degneration group (IL-1β) and treatment group (niacinamide+IL-1β). After culture for one week, AFs were collected for inducible nitric oxide synthase (iNOS), cysteine containing aspartate specific protease-3 (Caspase-3) and type Ⅱ collagen immunohistochemical examination, and type Ⅱ collagen reverse transcription polymerase chain reaction (RT-PCR). The results showed that rate of iNOS positive staining AF cells in the 4 groups was 17.6%, 10.9%, 73.9% and 19.3% respectively. The positive rate in treatment group was significantly lower than in the type Ⅱ collagen degeneration group (P<0.01). Rate of Caspase-3 positive staining AF cells in the 4 groups was 3.4%, 4.2%, 17.6% and 10.3% respectively. The positive rate in treatment group was lower than in the type Ⅱ collagen degeneration group (P<0.01). Type Ⅱ collagen staining demonstrated that lamellar structure and continuity of collagen in treatment group was better reversed than in the degeneration group. RT-PCR revealed that the expression of type Ⅱ collagen in treatment group was significantly stronger than that in type Ⅱ collagen degeneration group (P<0.01). It was concluded that niacinamide could effectively inhibit IL-1β stimulated increase of iNOS and Caspase-3 in AF, and alleviate IL-1β-caused destruction and synthesis inhibition of type Ⅱ collagen. Niacinamide is of potential for clinical treatment of IVD degeneration.

  3. Procedural method for the development of scenarios in the operational phase following closure of final repositories in deep geological formations. Report on the working package 1. Development of the international status of science and technology concerning methods and tools for operational and long-term safety cases; Vorgehensweise bei der Szenarienentwicklung in der Nachverschlussphase von Endlagern in tiefen geologieschen Formationen. Bericht zum Arbeitspaket 1. Weiterentwicklung des internationalen Stands von Wissenschaft und Technik zu Methoden und Werkzeugen fuer Betriebs- und Langzeitsicherheitsnachweise

    Energy Technology Data Exchange (ETDEWEB)

    Uhlmann, Stephan

    2016-09-15

    For the disposal of high-level radioactive wastes the disposal in deep geological formations is internationally favored. The safety cases include the scientific, technical, administrative and operational safety analyses and arguments, including the management system. According to IAEA the safety case includes site qualification, the design of the facility, construction and operation including an accident analysis, the closure phase and the post-closure phase. The safety case includes the evaluation of radiological risks for several scenarios. The report covers the methodology of scenario assumption in the post-closure phase of repositories in deep geological formations.

  4. Regulatory Closure Options for the Residue in the Hanford Site Single-Shell Tanks

    Energy Technology Data Exchange (ETDEWEB)

    Cochran, J.R. Shyr, L.J.

    1998-10-05

    Liquid, mixed, high-level radioactive waste (HLW) has been stored in 149 single-shell tanks (SSTS) located in tank farms on the U.S. Department of Energy's (DOE's) Hanford Site. The DOE is developing technologies to retrieve as much remaining HLW as technically possible prior to physically closing the tank farms. In support of the Hanford Tanks Initiative, Sandia National Laboratories has addressed the requirements for the regulatory closure of the radioactive component of any SST residue that may remain after physical closure. There is significant uncertainty about the end state of each of the 149 SSTS; that is, the nature and amount of wastes remaining in the SSTS after retrieval is uncertain. As a means of proceeding in the face of these uncertainties, this report links possible end-states with associated closure options. Requirements for disposal of HLW and low-level radioactive waste (LLW) are reviewed in detail. Incidental waste, which is radioactive waste produced incidental to the further processing of HLW, is then discussed. If the low activity waste (LAW) fraction from the further processing of HLW is determined to be incidental waste, then DOE can dispose of that incidental waste onsite without a license from the U.S. Nuclear Regulatory Commissions (NRC). The NRC has proposed three Incidental Waste Criteria for determining if a LAW fraction is incidental waste. One of the three Criteria is that the LAW fraction should not exceed the NRC's Class C limits.

  5. Regulatory Closure Options for the Residue in the Hanford Site Single-Shell Tanks

    Energy Technology Data Exchange (ETDEWEB)

    Cochran, J.R. Shyr, L.J.

    1998-10-05

    Liquid, mixed, high-level radioactive waste (HLW) has been stored in 149 single-shell tanks (SSTS) located in tank farms on the U.S. Department of Energy's (DOE's) Hanford Site. The DOE is developing technologies to retrieve as much remaining HLW as technically possible prior to physically closing the tank farms. In support of the Hanford Tanks Initiative, Sandia National Laboratories has addressed the requirements for the regulatory closure of the radioactive component of any SST residue that may remain after physical closure. There is significant uncertainty about the end state of each of the 149 SSTS; that is, the nature and amount of wastes remaining in the SSTS after retrieval is uncertain. As a means of proceeding in the face of these uncertainties, this report links possible end-states with associated closure options. Requirements for disposal of HLW and low-level radioactive waste (LLW) are reviewed in detail. Incidental waste, which is radioactive waste produced incidental to the further processing of HLW, is then discussed. If the low activity waste (LAW) fraction from the further processing of HLW is determined to be incidental waste, then DOE can dispose of that incidental waste onsite without a license from the U.S. Nuclear Regulatory Commissions (NRC). The NRC has proposed three Incidental Waste Criteria for determining if a LAW fraction is incidental waste. One of the three Criteria is that the LAW fraction should not exceed the NRC's Class C limits.

  6. Lip interactions and closure duration in labial consonants

    Science.gov (United States)

    Lofqvist, Anders

    2003-04-01

    This study examines interactions between the upper and lower lips in labial consonants where the duration of the oral closure is varied for linguistic purposes. Earlier work has shown that such interactions occur and that their magnitude is partly related to the duration of the oral closure. Lip movements were recorded in native Japanese speakers using a magnetometer system. Results show a positive correlation between the vertical positions of the upper and lower, when both are measured at the point in time where the lower lip reached its peak position during the oral closure. Since the peak vertical position of the lower lip increased with closure duration, the upper lip also had a higher vertical position at the same point in time for long than for short consonants. During the oral closure, the lower lip continued to move upward with a larger movement for long than for short consonants. Due to the mechanical interaction between the lips, the upper lip reversed its downward movement at the onset of the oral closure and also moved upward during the closure, again with a larger movement for long than for short consonants. [Work supported by NIH.

  7. Use of Amplatzer device for endobronchial closure of bronchopleural fistulas.

    Science.gov (United States)

    Kramer, Mordechai R; Peled, Nir; Shitrit, David; Atar, Eli; Saute, Milton; Shlomi, Dekel; Amital, Anat; Bruckheimer, Elchanan

    2008-06-01

    Bronchopulmonary fistula (BPF) is associated with high morbidity and mortality. It occurs as an uncommon but often severe complication of pneumonectomy. BPF may be treated by a range of surgical and medical techniques, including chest drain, Eloesser muscle flap, omental flap, transsternal bronchial closure, thoracoplasty, and prolonged therapy with antibiotic regimens. The use of bronchoscopy has been reported for the delivery of biological glue, coils, covered stents, and sealants. In this work, we describe a novel method of BPF closure using the Amplatzer device, which is commonly used for transcatheter closure of atrial septal defects.

  8. Coblation-assisted closure of persistent tracheocutaneous fistulae.

    Science.gov (United States)

    Walner, David L; Mularczyk, Chris; Kakodkar, Kedar

    2016-06-01

    Persistent tracheocutaneous fistulae (PTCFs) are sequelae of long-term tracheostomy tube use, and while many procedures exist to correct this issue, several are invasive and incur risk to the patient. This case study discusses a minimally invasive approach to closure of small PFTFs with a coblator device that may reduce the risks associated with other closure procedures. We demonstrated successful tracheocutaneous fistulae closure after coblation in all 4 patients that the operation was performed. We believe this technique can be considered for patients under select circumstances and can be part of a surgeon's armamentarium for the treatment of small PTCFs.

  9. PRECL: A new method for interferometry imaging from closure phase

    CERN Document Server

    Ikeda, Shiro; Akiyama, Kazunori; Hada, Kazuhiro; Honma, Mareki

    2016-01-01

    For short-wavelength VLBI observations, it is difficult to measure the phase of the visibility function accurately. The closure phases are reliable measurements under this situation, though it is not sufficient to retrieve all of the phase information. We propose a new method, Phase Retrieval from Closure Phase (PRECL). PRECL estimates all the visibility phases only from the closure phases. Combining PRECL with a sparse modeling method we have already proposed, imaging process of VLBI does not rely on dirty image nor self-calibration. The proposed method is tested numerically and the results are promising.

  10. Use of bipedicular advancement flaps for intrauterine closure of myeloschisis.

    Science.gov (United States)

    Mangels, K J; Tulipan, N; Bruner, J P; Nickolaus, D

    2000-01-01

    Several groups have begun to explore the feasibility and utility of intrauterine closure of myelomeningocele. A subset of these fetuses have defects which fall into the category of myeloschisis, and therefore have inadequate skin to enable primary closure. After considerable discussion, it was decided to utilize bipedicular flaps to close these lesions. The procedure is described, and representative examples are shown. To date, 13 of 56 fetuses have required this approach for closure in utero. While this technique generally provides adequate coverage of the dural sac, the cosmetic results have been less than optimal.

  11. Spurious Shell Closures in the Relativistic Mean Field Model

    CERN Document Server

    Geng, L S; Toki, H; Long, W H; Shen, G

    2006-01-01

    Following a systematic theoretical study of the ground-state properties of over 7000 nuclei from the proton drip line to the neutron drip line in the relativistic mean field model [Prog. Theor. Phys. 113 (2005) 785], which is in fair agreement with existing experimental data, we observe a few spurious shell closures, i.e. proton shell closures at Z=58 and Z=92. These spurious shell closures are found to persist in all the effective forces of the relativistic mean field model, e.g. TMA, NL3, PKDD and DD-ME2.

  12. Influence of St. Jude medical valve in patients with aortic stenosis and small aortic annulus on cardiac function and late survival result.

    Science.gov (United States)

    Natsuaki, Masafumi; Itoh, Tsuyoshi; Okazaki, Yukio; Takarabe, Kyoumi; Furukawa, Koujirou; Rikitake, Kazuhisa; Ohtubo, Satoshi

    2002-10-01

    This clinical study analyzes our experience of postoperative cardiac function and long-term survival rate in patients with aortic stenosis and small-size St. Jude Medical (SJM) valve. Sixty-eight patients who underwent aortic valve replacement by SJM valve were divided into two groups by preoperative aortic annulus diameter. Group 1 consisted of 44 patients with small aortic annulus and small-size SJM valve (19 mm or 21 mm). In Group 1, small SJM standard valves were implanted in 16 patients, and small SJM Hemodynamic Plus (HP) valves were implanted in 28 patients. Group 2 consisted of 24 patients with large-size SJM standard valve (23 mm or larger). Preoperative left ventricular mass index, left ventricular dimension, the dimension of ascending aorta, and body surface area were significantly smaller in Group 1 than in Group 2. Average age at surgery was older in Group 1 than in Group 2. Effective orifice area index of the SJM valve measured by the manufacturer's data was smaller in Group 1 than in Group 2. Postoperative left ventricular mass indexes of Group 1 (standard valve or HP valve) and Group 2 significantly decreased in comparison with the preoperative mass indexes. Postoperative left ventricular ejection fraction and the peak ejection rate of Group 1 were not different from those of Group 2. The 10 year survival rate of Group 1 was 79%, and the rate of Group 2 was 77%. At 10 years after surgery, freedom from valve-related complication of Group 1 was 80%, and freedom from complication of Group 2 was 81%. Our results demonstrated that small-size SJM valve afforded satisfactory long-term survival rate and valve-related event-free rate for elderly patients with small body surface area and small aortic annulus.

  13. Comparison of Outcomes between Early Fascial Closure and Delayed Abdominal Closure in Patients with Open Abdomen: A Systematic Review and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Yu Chen

    2014-01-01

    Full Text Available Up to the present, the optimal time to close an open abdomen remains controversial. This study was designed to evaluate whether early fascial abdominal closure had advantages over delayed approach for open abdomen populations. Medline, Embase, and Cochrane Library were searched until April 2013. Search terms included “open abdomen,” “abdominal compartment syndrome,” “laparostomy,” “celiotomy,” “abdominal closure,” “primary,” “delayed,” “permanent,” “fascial closure,” and “definitive closure.” Open abdomen was defined as “fail to close abdominal fascia after a laparotomy.” Mortality, complications, and length of stay were compared between early and delayed fascial closure. In total, 3125 patients were included for final analysis, and 1942 (62% patients successfully achieved early fascial closure. Vacuum assisted fascial closure had no impact on pooled fascial closure rate. Compared with delayed abdominal closure, early fascial closure significantly reduced mortality (12.3% versus 24.8%, RR, 0.53, P<0.0001 and complication incidence (RR, 0.68, P<0.0001. The mean interval from open abdomen to definitive closure ranged from 2.2 to 14.6 days in early fascial closure groups, but from 32.5 to 300 days in delayed closure groups. This study confirmed clinical advantages of early fascial closure over delayed approach in treatment of patients with open abdomen.

  14. AN EXPERIMENTAL STUDY ON THREE-DIMENSIONAL STRUCTURE OF BAROCLINIC WAVY JET STREAM IN A ROTATING ANNULUS SUBJECT TO RADIAL TEMPERATURE GRADIENT

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Three-dimensional structure of baroclinic wavy jet was experimentally studied in rotating annulus subject to a negative radial temperature gradient.General features of wavy surface jet in the system were obtained.Based on the precise measurements of velocity distribution of the jet with LDV and the three-dimensional temperature field in the convective system, three-dimensional thermodynamic structures of jet were gained, and by using a correlation of three-dimensional disturbed temperature, the unstable mechanism of disturbed temperature of baroclinic fluid in a rotating system was further discussed.

  15. Performance of transonic fan stage with weight flow per unit annulus area of 198 kilograms per second per square meter (40.6(lb/sec)/sq ft)

    Science.gov (United States)

    Kovich, G.; Moore, R. D.; Urasek, D. C.

    1973-01-01

    The overall and blade-element performance are presented for an air compressor stage designed to study the effect of weight flow per unit annulus area on efficiency and flow range. At the design speed of 424.8 m/sec the peak efficiency of 0.81 occurred at the design weight flow and a total pressure ratio of 1.56. Design pressure ratio and weight flow were 1.57 and 29.5 kg/sec (65.0 lb/sec), respectively. Stall margin at design speed was 19 percent based on the weight flow and pressure ratio at peak efficiency and at stall.

  16. Aortic valve annulus and sinus-tube joint diameters in normal adults of Chinese Han ethnic group

    Institute of Scientific and Technical Information of China (English)

    ZHU Dan; ZHAO Qiang

    2008-01-01

    Background The anatomic value of the aortic root is important for aortic valve repair.This study was to determine the normaI diameters of the aortic valve annulus (AVA) and sinus-tube ioint (STJ) in the healthy adults of Chinese Han ethnic group,and to provide a morphological foundation for potential clinical application.Methods Echocardiography was performed in 326 normal subjects,who were divided into 5 groups according to their age.The diameters of the AVA and STJ were measured in the parasternal long-axis view.and normalized to body surface area (BSA).They were averaged for each age group and for each gender.Differences were then determined between the normalized diameters for each age group and for both genders.Pearson's product-moment correlation coefficient was used to determine the differences between AVA and STJ diameters.It was also used to determine any positive or neqative correlations between the above two variables and age,BSA,weight,and height.Results The diameters of the AVA and STJ of Han nationality patients increased with an increase in age,BSA,weight,and height.The correlation coefficient between AVA diameter and BSA was 0.4944 (P<0.0001),between AVA diameter and age,0.1138 (P<0.05),between AVA diameter and weight,0.4521 (P<0.001),and between AVAdiameter and height,0.471 3 (P<0.001).The correlation coefficient between STJ diameter and BSA was 0.3910 (P<0.0001),between STJ diameter and age,0.3667 (P<0.0001),between STJ diameter and weight,0.4586 (P<0.0001),and between STJ diameter and height,0.3736 (P<0.0001).The difference between the above two diameters was statistically significant at 2.42±2.45 mm (paired t-test:t=-17.25;P<0.0001).AVA and STJ diameters were similar in both genders of each group when indexed to BSAConclusions The diameters of the AVA and STJ of adults of Chinese Han ethnic group increase with age,BSA,weight,and height.The diameters of the AVA and the STJ are similar in both genders.when indexed to BSA

  17. Case Report: Rapid staged abdominal closure using Gore-Tex® mesh as a bridge to primary omphalocele sac closure

    Directory of Open Access Journals (Sweden)

    William C. Kethman

    2016-06-01

    Full Text Available Omphaloceles present an ongoing challenge due to significant variations in presentation and associated co-morbidities. Diverse management strategies have been described to tackle many of the fundamental challenges of closure and reconstruction of the abdominal wall – this fact demonstrates a need for increasingly individualized management options for this complex disease. We describe a novel method of rapid staged abdominal wall closure using Gore-Tex® mesh as a bridge to primary omphalocele closure in an infant with partial Pentalogy of Cantrell and giant ruptured omphalocele. This strategy can be used in management of some of the most complex abdominal wall defects.

  18. Don’t call it a closure!

    CERN Multimedia

    Rosaria Marraffino

    2015-01-01

    During the Laboratory’s annual closure, some members of the personnel joined their families, others seized the chance to travel the world. The Restaurants were closed, the corridors were dark and the heating was turned off in most of the buildings. However, a lot of people spent the Christmas break working on site and the Bulletin would like to dedicate this first article of the new year to them all!   In the CERN Control Centre (CCC), each shift had two people in position to guarantee regular 24/7 service and to intervene in case of need. Gildas Langlois and Rodolphe Maillet, CCC operators from the Beams Department, spent Christmas Eve there and celebrated it with a cake. “I volunteered to work during the holidays in order to allow colleagues to stay with their families,” says Maillet. On New Year’s Eve, it was Julien Pache and Jean-Michel Nonglaton’s turn to spend the night at work. They had a nice dinner with a CCC-made fondue and some desse...

  19. Friction or Closure: Heritage as Loss

    Directory of Open Access Journals (Sweden)

    Mikela Lundahl

    2014-12-01

    Full Text Available Heritage is a discourse that aims at closure. It fixates the narrative of the past through the celebration of specific material (or sometimes immaterial non- objects. It organizes temporality and construct events and freezes time. How does this unfold in the case of the UNESCO World Heritage site of Stone Town, Zanzibar? It is a place of beauty and violence, of trade, slavery and tourism, and the World Heritage narrative does not accommodate all its significant historical facts and lived memories. In this article I will discuss some of these conflicting or competing historical facts. The anthropologist Anna Tsing has developed the concept-metaphor friction as a way to discuss the energy created when various actors narrate 'the same' event(s in different ways, and see the other participants' accounts as fantasies or even fabrications. I will use my position as researcher and my relations to different sources: informants, authorities and texts, and discuss how different accounts relate to and partly construct each other; and how I, in my own process as an analyst and listener, negotiate these conflicting stories, what I identify as valid and non valid accounts. The case in this article is Stone Town in Zanzibar and the development and dissolution going on under the shadow of the UNESCO World Heritage flag; a growing tourism; a global and local increase in islamisation; and the political tension within the Tanzanian union. My main focus is narratives of the identity of Zanzibar since heritagization constructs identity.

  20. IT Services availability during CERN annual closure

    CERN Multimedia

    2003-01-01

    Mail, Cern Windows (NICE ),  Web services,  LXPLUS, LXBATCH, Automated tape devices, Castor, Backups, software license servers, Sundev, CVS and Print Servers, CDS and Agenda-Maker, EDMS (in collaboration with EST Division), CMS disc servers, Campus Network,  Remedy, Security and VPN services will be available during the CERN annual closure. The physics database cluster, replication location service as well as accdb, cerndb and admsdb are the only databases available, CCDB will be closed for public access. Problems developing on scheduled services should be addressed within about half a day except around  Christmas Eve and Christmas Day ( 24 and 25th December ) and New Year's Eve and New Years Day (31st December and 1st Janauary. All other services will be left running mostly unattended. No interruptions are scheduled but restoration of the service in case of failure cannot be guaranteed. Please note that the Helpdesk will be closed, that no file restores from backups will be possible and damaged tapes wi...

  1. IT Services availability during CERN annual closure

    CERN Multimedia

    2003-01-01

    Mail, Cern Windows (NICE ),  Web services,  LXPLUS, LXBATCH, Automated tape devices, Castor, Backups, software license servers, Sundev, CVS and Print Servers, CDS and Agenda-Maker, EDMS (in collaboration with EST Division), CMS disc servers, Campus Network,  Remedy, Security and VPN services will be available during the CERN annual closure. The physics database cluster, replication location service as well as accdb, cerndb and admsdb are the only databases available, CCDB will be closed for public access. Problems developing on scheduled services should be addressed within about half a day except around  Christmas Eve and Christmas Day ( 24 and 25th December ) and New Year's Eve and New Years Day (31st December and 1st Janauary. All other services will be left running mostly unattended. No interruptions are scheduled but restoration of the service in case of failure cannot be guaranteed. Please note that the Helpdesk will be closed, that no file restores from backups will be possible and damaged tapes wi...

  2. Maximum-entropy closure of hydrodynamic moment hierarchies including correlations.

    Science.gov (United States)

    Hughes, Keith H; Burghardt, Irene

    2012-06-07

    Generalized hydrodynamic moment hierarchies are derived which explicitly include nonequilibrium two-particle and higher-order correlations. The approach is adapted to strongly correlated media and nonequilibrium processes on short time scales which necessitate an explicit treatment of time-evolving correlations. Closure conditions for the extended moment hierarchies are formulated by a maximum-entropy approach, generalizing related closure procedures for kinetic equations. A self-consistent set of nonperturbative dynamical equations are thus obtained for a chosen set of single-particle and two-particle (and possibly higher-order) moments. Analytical results are derived for generalized Gaussian closures including the dynamic pair distribution function and a two-particle correction to the current density. The maximum-entropy closure conditions are found to involve the Kirkwood superposition approximation.

  3. Autocracy bias in informal groups under need for closure.

    Science.gov (United States)

    Pierro, Antonio; Mannetti, Lucia; De Grada, Eraldo; Livi, Stefano; Kruglanski, Arie W

    2003-03-01

    Two experiments investigated the tendency of groups with members under high (vs. low) need for cognitive closure to develop an autocratic leadership structure in which some members dominate the discussion, constitute the "hubs" of communication, and influence the group more than other members. The first experiment found that high (vs. low) need for closure groups, as assessed via dispositional measure of the need for closure, manifested greater asymmetry of conversational floor control, such that members with autocratic interactional style were more conversationally dominant and influential than less autocratic members. The second experiment manipulated the need for closure via time pressure and utilized a social network analysis. Consistent with expectation, groups under time pressure (vs. no pressure) showed a greater asymmetry of participation, of centrality, and of prestige among the group members, such that the more focal members were perceived to exert the greater influence over the groups' decisions.

  4. Simultaneous oroantral communication closure, sinus‑lifting, and ...

    African Journals Online (AJOL)

    2015-10-10

    Oct 10, 2015 ... revealed healthy and functional implants in the teeth area. Key words: .... the development of several alternative treatment modalities by some ... 1. Lee BK. One‑stage operation of large oroantral fistula closure, sinus lifting,.

  5. Optical closure of parameterized bio-optical relationships

    Science.gov (United States)

    He, Shuangyan; Fischer, Jürgen; Schaale, Michael; He, Ming-xia

    2014-03-01

    An optical closure study on bio-optical relationships was carried out using radiative transfer model matrix operator method developed by Freie Universität Berlin. As a case study, the optical closure of bio-optical relationships empirically parameterized with in situ data for the East China Sea was examined. Remote-sensing reflectance ( R rs) was computed from the inherent optical properties predicted by these biooptical relationships and compared with published in situ data. It was found that the simulated R rs was overestimated for turbid water. To achieve optical closure, bio-optical relationships for absorption and scattering coefficients for suspended particulate matter were adjusted. Furthermore, the results show that the Fournier and Forand phase functions obtained from the adjusted relationships perform better than the Petzold phase function. Therefore, before bio-optical relationships are used for a local sea area, the optical closure should be examined.

  6. 40 CFR 264.119 - Post-closure notices.

    Science.gov (United States)

    2010-07-01

    ... disposal unit is located wishes to remove hazardous wastes and hazardous waste residues, the liner, if any, or contaminated soils, he must request a modification to the post-closure permit in accordance...

  7. 300 Area waste acid treatment system closure plan

    Energy Technology Data Exchange (ETDEWEB)

    LUKE, S.N.

    1999-05-17

    The Hanford Facility Dangerous Waste Permit Application is considered to be a single application organized into a General Information Portion (document number DOERL-91-28) and a Unit-Specific Portion. The scope of the Unit-Specific Portion includes closure plan documentation submitted for individual, treatment, storage, and/or disposal units undergoing closure, such as the 300 Area Waste Acid Treatment System. Documentation contained in the General Information Portion is broader in nature and could be used by multiple treatment, storage, and/or disposal units (e.g., the glossary provided in the General Information Portion). Whenever appropriate, 300 Area Waste Acid Treatment System documentation makes cross-reference to the General Information Portion, rather than duplicating text. This 300 Area Waste Acid Treatment System Closure Plan (Revision 2) includes a Hanford Facility Dangerous Waste Permit Application, Part A, Form 3. Information provided in this closure plan is current as of April 1999.

  8. EPIDERMAL DELETION OF HIF-2α STIMULATES WOUND CLOSURE

    Science.gov (United States)

    Cowburn, Andrew S.; Crotty Alexander, Laura E.; Southwood, Mark; Nizet, Victor; Chilvers, Edwin R.; Johnson, Randall S.

    2013-01-01

    Wound closure requires a complex series of micro-environmentally influenced events. A key aspect of wound closure is the migration of keratinocytes across the open wound. It has been found previously that the response to hypoxia via the HIF-1α transcription factor is a key feature of wound closure. The need for hypoxic response is likely due to interrupted wound vasculature as well as infection, and in this work, we investigated the need for a highly related hypoxic response transcription factor, HIF-2α. This factor was deleted tissue-specifically in mice, and the resulting mice were found to have an accelerated rate of wound closure. This is correlated with a reduced bacterial load and inflammatory response in these mice. This indicates that manipulating or reducing the HIF-2α response in keratinocytes could be a useful means to accelerate wound healing and tissue repair. PMID:24037341

  9. Procedures adopted by orthodontists for space closure and anchorage control

    Directory of Open Access Journals (Sweden)

    André da Costa Monini

    2013-12-01

    Full Text Available OBJECTIVE: The aim of this study was to identify the procedures adopted by Brazilian orthodontists in the following situations: extraction space closure, anchorage control in case of necessary anchorage for group A and frequency of skeletal anchorage use, especially in the upper jaw. METHOD: A questionnaire was sent to the e-mail address of all dentists registered in the Brazilian Federal Council of Dentistry. RESULTS: The results showed that most Brazilian orthodontists usually perform extraction space closure by means of sliding mechanics. The use of palatal bar, inclusion of second molars in the archwire and space closure performed in two phases are the most used techniques for anchorage control in the upper jaw. The skeletal anchorage is referenced by 36.5% of specialists as a routine practice for the upper jaw anchorage. CONCLUSIONS: There is a wide variety of procedures adopted by Brazilian orthodontists for orthodontic space closure and anchorage control.

  10. Nonlinear closures for scale separation in supersonic magnetohydrodynamic turbulence

    CERN Document Server

    Grete, Philipp; Schmidt, Wolfram; Schleicher, Dominik R G; Federrath, Christoph

    2015-01-01

    Turbulence in compressible plasma plays a key role in many areas of astrophysics and engineering. The extreme plasma parameters in these environments, e.g. high Reynolds numbers, supersonic and super-Alfvenic flows, however, make direct numerical simulations computationally intractable even for the simplest treatment -- magnetohydrodynamics (MHD). To overcome this problem one can use subgrid-scale (SGS) closures -- models for the influence of unresolved, subgrid-scales on the resolved ones. In this work we propose and validate a set of constant coefficient closures for the resolved, compressible, ideal MHD equations. The subgrid-scale energies are modeled by Smagorinsky-like equilibrium closures. The turbulent stresses and the electromotive force (EMF) are described by expressions that are nonlinear in terms of large scale velocity and magnetic field gradients. To verify the closures we conduct a priori tests over 137 simulation snapshots from two different codes with varying ratios of thermal to magnetic pre...

  11. Neural tube closure: cellular, molecular and biomechanical mechanisms.

    Science.gov (United States)

    Nikolopoulou, Evanthia; Galea, Gabriel L; Rolo, Ana; Greene, Nicholas D E; Copp, Andrew J

    2017-02-15

    Neural tube closure has been studied for many decades, across a range of vertebrates, as a paradigm of embryonic morphogenesis. Neurulation is of particular interest in view of the severe congenital malformations - 'neural tube defects' - that result when closure fails. The process of neural tube closure is complex and involves cellular events such as convergent extension, apical constriction and interkinetic nuclear migration, as well as precise molecular control via the non-canonical Wnt/planar cell polarity pathway, Shh/BMP signalling, and the transcription factors Grhl2/3, Pax3, Cdx2 and Zic2. More recently, biomechanical inputs into neural tube morphogenesis have also been identified. Here, we review these cellular, molecular and biomechanical mechanisms involved in neural tube closure, based on studies of various vertebrate species, focusing on the most recent advances in the field.

  12. Approximate maximum-entropy moment closures for gas dynamics

    Science.gov (United States)

    McDonald, James G.

    2016-11-01

    Accurate prediction of flows that exist between the traditional continuum regime and the free-molecular regime have proven difficult to obtain. Current methods are either inaccurate in this regime or prohibitively expensive for practical problems. Moment closures have long held the promise of providing new, affordable, accurate methods in this regime. The maximum-entropy hierarchy of closures seems to offer particularly attractive physical and mathematical properties. Unfortunately, several difficulties render the practical implementation of maximum-entropy closures very difficult. This work examines the use of simple approximations to these maximum-entropy closures and shows that physical accuracy that is vastly improved over continuum methods can be obtained without a significant increase in computational cost. Initially the technique is demonstrated for a simple one-dimensional gas. It is then extended to the full three-dimensional setting. The resulting moment equations are used for the numerical solution of shock-wave profiles with promising results.

  13. Patent Foramen Ovale Closure or Antiplatelet Therapy for Cryptogenic Stroke

    DEFF Research Database (Denmark)

    Søndergaard, Lars; Kasner, Scott E; Rhodes, John F

    2017-01-01

    Background The efficacy of closure of a patent foramen ovale (PFO) in the prevention of recurrent stroke after cryptogenic stroke is uncertain. We investigated the effect of PFO closure combined with antiplatelet therapy versus antiplatelet therapy alone on the risks of recurrent stroke and new...... brain infarctions. Methods In this multinational trial involving patients with a PFO who had had a cryptogenic stroke, we randomly assigned patients, in a 2:1 ratio, to undergo PFO closure plus antiplatelet therapy (PFO closure group) or to receive antiplatelet therapy alone (antiplatelet-only group......). Imaging of the brain was performed at the baseline screening and at 24 months. The coprimary end points were freedom from clinical evidence of ischemic stroke (reported here as the percentage of patients who had a recurrence of stroke) through at least 24 months after randomization and the 24-month...

  14. Threats and opportunities for post-closure development in dolomitic ...

    African Journals Online (AJOL)

    Threats and opportunities for post-closure development in dolomitic ... in the form of sinkholes and widespread radioactive pollution exacerbate such fears. ... developments such as aquaculture, agriculture and different forms of tourism relating ...

  15. 300 Area waste acid treatment system closure plan. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    This section provides a description of the Hanford Site, identifies the proposed method of 300 Area Waste Acid Treatment System (WATS) closure, and briefly summarizes the contents of each chapter of this plan.

  16. Economic evaluation of closure cap barrier materials study

    Energy Technology Data Exchange (ETDEWEB)

    Serrato, M.G.; Bhutani, J.S.; Mead, S.M.

    1993-09-01

    Volume II of the Economic Evaluation of the Closure Cap Barrier Materials, Revision I contains detailed cost estimates for closure cap barrier materials. The cost estimates incorporate the life cycle costs for a generic hazardous waste seepage basin closure cap under the RCRA Post Closure Period of thirty years. The economic evaluation assessed six barrier material categories. Each of these categories consists of several composite cover system configurations, which were used to develop individual cost estimates. The information contained in this report is not intended to be used as a cost estimating manual. This information provides the decision makers with the ability to screen barrier materials, cover system configurations, and identify cost-effective materials for further consideration.

  17. A closure relation to molecular theory of solvation for macromolecules

    Science.gov (United States)

    Kobryn, Alexander E.; Gusarov, Sergey; Kovalenko, Andriy

    2016-10-01

    We propose a closure to the integral equations of molecular theory of solvation, particularly suitable for polar and charged macromolecules in electrolyte solution. This includes such systems as oligomeric polyelectrolytes at a finite concentration in aqueous and various non-aqueous solutions, as well as drug-like compounds in solution. The new closure by Kobryn, Gusarov, and Kovalenko (KGK closure) imposes the mean spherical approximation (MSA) almost everywhere in the solvation shell but levels out the density distribution function to zero (with the continuity at joint boundaries) inside the repulsive core and in the spatial regions of strong density depletion emerging due to molecular associative interactions. Similarly to MSA, the KGK closure reduces the problem to a linear equation for the direct correlation function which is predefined analytically on most of the solvation shells and has to be determined numerically on a relatively small (three-dimensional) domain of strong depletion, typically within the repulsive core. The KGK closure leads to the solvation free energy in the form of the Gaussian fluctuation (GF) functional. We first test the performance of the KGK closure coupled to the reference interaction site model (RISM) integral equations on the examples of Lennard-Jones liquids, polar and nonpolar molecular solvents, including water, and aqueous solutions of simple ions. The solvation structure, solvation chemical potential, and compressibility obtained from RISM with the KGK closure favorably compare to the results of the hypernetted chain (HNC) and Kovalenko-Hirata (KH) closures, including their combination with the GF solvation free energy. We then use the KGK closure coupled to RISM to obtain the solvation structure and thermodynamics of oligomeric polyelectrolytes and drug-like compounds at a finite concentration in electrolyte solution, for which no convergence is obtained with other closures. For comparison, we calculate their solvation

  18. Patent Foramen Ovale Closure or Antiplatelet Therapy for Cryptogenic Stroke.

    Science.gov (United States)

    Søndergaard, Lars; Kasner, Scott E; Rhodes, John F; Andersen, Grethe; Iversen, Helle K; Nielsen-Kudsk, Jens E; Settergren, Magnus; Sjöstrand, Christina; Roine, Risto O; Hildick-Smith, David; Spence, J David; Thomassen, Lars

    2017-09-14

    The efficacy of closure of a patent foramen ovale (PFO) in the prevention of recurrent stroke after cryptogenic stroke is uncertain. We investigated the effect of PFO closure combined with antiplatelet therapy versus antiplatelet therapy alone on the risks of recurrent stroke and new brain infarctions. In this multinational trial involving patients with a PFO who had had a cryptogenic stroke, we randomly assigned patients, in a 2:1 ratio, to undergo PFO closure plus antiplatelet therapy (PFO closure group) or to receive antiplatelet therapy alone (antiplatelet-only group). Imaging of the brain was performed at the baseline screening and at 24 months. The coprimary end points were freedom from clinical evidence of ischemic stroke (reported here as the percentage of patients who had a recurrence of stroke) through at least 24 months after randomization and the 24-month incidence of new brain infarction, which was a composite of clinical ischemic stroke or silent brain infarction detected on imaging. We enrolled 664 patients (mean age, 45.2 years), of whom 81% had moderate or large interatrial shunts. During a median follow-up of 3.2 years, clinical ischemic stroke occurred in 6 of 441 patients (1.4%) in the PFO closure group and in 12 of 223 patients (5.4%) in the antiplatelet-only group (hazard ratio, 0.23; 95% confidence interval [CI], 0.09 to 0.62; P=0.002). The incidence of new brain infarctions was significantly lower in the PFO closure group than in the antiplatelet-only group (22 patients [5.7%] vs. 20 patients [11.3%]; relative risk, 0.51; 95% CI, 0.29 to 0.91; P=0.04), but the incidence of silent brain infarction did not differ significantly between the study groups (P=0.97). Serious adverse events occurred in 23.1% of the patients in the PFO closure group and in 27.8% of the patients in the antiplatelet-only group (P=0.22). Serious device-related adverse events occurred in 6 patients (1.4%) in the PFO closure group, and atrial fibrillation occurred in 29

  19. Flows in Concentric Annulus

    Directory of Open Access Journals (Sweden)

    Shuichi Torii

    1998-01-01

    stress turbulence model is employed to determine three normal components of the Reynolds stress and its off-diagonal one. The turbulent heat flux is expressed by Boussinesq approximation in which the eddy diffusivity.for heat is given as functions of the temperature variance t2¯ and the dissipation rate of temperate fluctuations εt. The governing boundarylayer equations are discretized by means of a control volume finite-difference technique and numerically solved using the marching procedure. An inner core rotation causes an amplification of the three normal components of the Reynolds stress over the whole cross section, resulting in a substantial enhancement in the Nusselt number.

  20. 303-K Storage Facility report on FY98 closure activities

    Energy Technology Data Exchange (ETDEWEB)

    Adler, J.G.

    1998-07-17

    This report summarizes and evaluates the decontamination activities, sampling activities, and sample analysis performed in support of the closure of the 303-K Storage Facility. The evaluation is based on the validated data included in the data validation package (98-EAP-346) for the 303-K Storage Facility. The results of this evaluation will be used for assessing contamination for the purpose of closing the 303-K Storage Facility as described in the 303-K Storage Facility Closure Plan, DOE/RL-90-04. The closure strategy for the 303-K Storage Facility is to decontaminate the interior of the north half of the 303-K Building to remove known or suspected dangerous waste contamination, to sample the interior concrete and exterior soils for the constituents of concern, and then to perform data analysis, with an evaluation to determine if the closure activities and data meet the closure criteria. The closure criteria for the 303-K Storage Facility is that the concentrations of constituents of concern are not present above the cleanup levels. Based on the evaluation of the decontamination activities, sampling activities, and sample data, determination has been made that the soils at the 303-K Storage Facility meet the cleanup performance standards (WMH 1997) and can be clean closed. The evaluation determined that the 303-K Building cannot be clean closed without additional closure activities. An additional evaluation will be needed to determine the specific activities required to clean close the 303-K Storage Facility. The radiological contamination at the 303-K Storage Facility is not addressed by the closure strategy.

  1. Synthesis of Pyridoacridines through Anionic Cascade Ring Closure

    DEFF Research Database (Denmark)

    Petersen, I.N.; Kristensen, Jesper Langgaard

    2014-01-01

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

  2. Techniques and materials for skin closure in caesarean section

    DEFF Research Database (Denmark)

    Mackeen, A Dhanya; Berghella, Vincenzo; Larsen, Mie-Louise

    2012-01-01

    Caesarean section is a common operation with no agreed upon standard regarding certain operative techniques or materials to use. With regard to skin closure, the skin incision can be re-approximated by a subcuticular suture immediately below the skin layer, by an interrupted suture, or by staples....... A great variety of materials and techniques are used for skin closure after caesarean section and there is a need to identify which provide the best outcomes for women....

  3. Apoptosis is not required for mammalian neural tube closure.

    Science.gov (United States)

    Massa, Valentina; Savery, Dawn; Ybot-Gonzalez, Patricia; Ferraro, Elisabetta; Rongvaux, Anthony; Cecconi, Francesco; Flavell, Richard; Greene, Nicholas D E; Copp, Andrew J

    2009-05-19

    Apoptotic cell death occurs in many tissues during embryonic development and appears to be essential for processes including digit formation and cardiac outflow tract remodeling. Studies in the chick suggest a requirement for apoptosis during neurulation, because inhibition of caspase activity was found to prevent neural tube closure. In mice, excessive apoptosis occurs in association with failure of neural tube closure in several genetic mutants, but whether regulated apoptosis is also necessary for neural tube closure in mammals is unknown. Here we investigate the possible role of apoptotic cell death during mouse neural tube closure. We confirm the presence of apoptosis in the neural tube before and during closure, and identify a correlation with 3 main events: bending and fusion of the neural folds, postfusion remodeling of the dorsal neural tube and surface ectoderm, and emigration of neural crest cells. Both Casp3 and Apaf1 null embryos exhibit severely reduced apoptosis, yet neurulation proceeds normally in the forebrain and spine. In contrast, the mutant embryos fail to complete neural tube closure in the midbrain and hindbrain. Application of the apoptosis inhibitors z-Vad-fmk and pifithrin-alpha to neurulation-stage embryos in culture suppresses apoptosis but does not prevent initiation or progression of neural tube closure along the entire neuraxis, including the midbrain and hindbrain. Remodeling of the surface ectoderm to cover the closed tube, as well as delamination and migration of neural crest cells, also appear to be normal in the apoptosis-suppressed embryos. We conclude that apoptosis is not required for neural tube closure in the mouse embryo.

  4. Primary fascial closure with laparoscopic ventral hernia repair: systematic review.

    Science.gov (United States)

    Nguyen, Duyen H; Nguyen, Mylan T; Askenasy, Erik P; Kao, Lillian S; Liang, Mike K

    2014-12-01

    Laparoscopic ventral hernia repair (LVHR) has grown in popularity. Typically, this procedure is performed with a mesh bridge technique that results in high rates of seroma, eventration (bulging), and patient dissatisfaction. In an effort to avoid these complications, there is growing interest in the role of laparoscopic primary fascial closure with intraperitoneal mesh placement. This systematic review evaluated the outcomes of closure of the central defect during LVHR. A literature search of PubMed, Cochrane databases, and Embase was conducted using PRISMA guidelines. MINORS was used to assess the methodologic quality. Primary outcome was hernia recurrence. Secondary outcomes were surgical-site infection, seroma formation, bulging, and patient-centered items (satisfaction, chronic pain, functional status). Eleven studies were identified, eight of which were case series (level 4 data). Three comparative studies examined the difference between closure and nonclosure of the fascial defect during laparoscopic ventral incisional hernia repairs (level 3 and 4 data). These studies suggested that primary fascial closure (n = 138) compared to nonclosure (n = 255) resulted in lower recurrence rates (0-5.7 vs. 4.8-16.7 %) and seroma formation rates (5.6-11.4 vs. 4.3-27.8 %). Follow-up periods for both groups were similar (1-108 months). Only one study evaluated patient function and clinical bulging. It showed better outcomes with primary fascial closure. Closure of the central defect during LVHR resulted in less recurrence, bulging, and seroma than nonclosure. Patients with closure were more satisfied with the results and had better functional status. The quality of the data was poor, however. A randomized controlled trial to evaluate the role of closure of the central defect during LVHR is warranted.

  5. HERA Mock Observations: Looking for Closure HERA Memorandum Number 13

    CERN Document Server

    Carilli, C L

    2016-01-01

    We investigate the use of closure phase as a method to detect the HI 21cm signal from the neutral IGM during cosmic reionzation. Closure quantities have the unique advantage of being independent of antenna-based calibration terms. We employ realistic, large area sky models from Sims et al. (2016). These include an estimate of the HI 21cm signal generated using 21cm FAST, plus continuum models of both the diffuse Galactic synchrotron emission and the extragalactic point sources. We employ the CASA simulator and adopt the Dillon-Parsons HERA configuration to generate a uv measurement set. We then use AIPS to calculate the closure phases as a function of frequency ('closure spectra'), and python scripts for subsequent analysis. We find that the closure spectra for the HI signal show dramatic structure in frequency, and based on thermal noise alone, the redundant HERA-331 array should detect these fluctuations easily. Comparatively, the frequency structure in the continuum closure spectra is much smoother than th...

  6. OCULAR BIOMETRY IN ANGLE CLOSURE GLAUCOMA AND SENILE CATARACT

    Institute of Scientific and Technical Information of China (English)

    WANG Yu-lan; SHENG Yao-hua; YE Xiang-yu

    2008-01-01

    Objective To compare ocular biometric values in angle closure glaucoma and cataract in senile population.Methods Ocular biometry was performed in eyes classified to have angle closure glaucoma (29 eyes) and senile cataract (31 eyes). Ocular biometry readings between two groups were compared and analyzed statistically. Intraocular pressure was also recorded before and after lens extraction.Results Anterior chamber depth was shallower in patients with angle closure glaucoma group [(1.79±0.56) mm] compared with senile cataract group [(2.69±0.40) mm] (P<0.01). Lens thickness was greater in angle closure glaucoma group [(5.30±0.61) mm] than that in senile cataract group [(3.84±0.61) mm] (P<0.01). Phacoemusification was performed in 5 patients with persistent acute attack of angle closure glaucoma. IOPs were controlled in all five cases after lens extraction.Conclusion Eyes with angle closure glaucoma seems to have significantly shallow anterior chamber and greater lens thickness compared to senile cataract eyes in the same age. Lens extraction might be effective in those cases with such anatomy features.

  7. Levels of control and closure in complex semiotic systems

    Science.gov (United States)

    Joslyn

    2000-01-01

    It is natural to advance closures as atomic processes of universal evolution, and to analyze this concept specifically. Real complex systems like organisms and complex mechanisms cannot exist at either extreme of complete closure or lack of closure, nevertheless we should consider the properties of closures in general, the introduction of boundaries, a corresponding stability, the establishment of system autonomy and identity, and thereby the introduction of emergent new system of potentially new types. Our focus should move from simple physical closure of common objects and classical self-organizing systems to semiotically closed systems that maintain cyclic relations of perception, interpretation, decision, and action with their environments. Thus, issues arise concerning the use and interpretation of symbols, representations, and/or internal models (whether explicit or implicit) by the system; and the syntactic, semantic, and pragmatic relations among the sign tokens, their interpretations, and their use or function for the systems in question. Primitive semiotic closures are hypothesized as equivalent to simple control systems, and in turn equivalent to simple organisms. This leads us directly to the grand hierarchical control theories of Turchin, Powers, and Albus, which provide an explicit mechanism for the formation of new levels within complex semiotically closed systems.

  8. Fresh Autologous Pericardium to Reconstruct the Pulmonary Valve at the Annulus When Tetralogy of Fallot Requires a Transannular Patch at Midterm.

    Science.gov (United States)

    Pande, Shantanu; Sharma, Jugal K; Siddartha, C R; Bansal, Anubhav; Agarwal, Surendra K; Tewari, Prabhat; Kapoor, Aditya

    2016-06-01

    Tetralogy of Fallot often requires reconstruction of the right ventricular outflow tract with a transannular patch (TAP), but this renders the pulmonary valve incompetent and eventually leads to right ventricular dysfunction. We retrospectively evaluated the efficacy of a reconstructed pulmonary valve and annulus in 70 patients who underwent, from December 2006 through December 2010, complete correction of tetralogy of Fallot. We divided the 70 patients into 2 groups in accordance with whether they required (n=50) or did not require (n=20) a TAP. We used autologous untreated pericardium to fashion the TAP and to create both an annulus of the correct size and a competent pulmonary valve with native leaflets. We evaluated the efficiency of this procedure both functionally and anatomically. The median age of the patients was 11 years (range, 2-38 yr). There were 56 males, with no significant difference in sexual distribution between groups. The clinical follow-up was 88% for 57.5 months, and the echocardiographic follow-up was 80% for 36 months. There was no significant difference in outflow gradient or in the occurrence of pulmonary insufficiency between the TAP group (none, 31; mild, 12; moderate, 6; and severe, 1) and the No-TAP group (none, 16; moderate, 2; and severe, 2) (P=0.59). Nor was there any thickening or calcification in the constructed valves. We conclude that pulmonary valves constructed of untreated autologous pericardium performed as well as native valves after total tetralogy of Fallot correction at midterm.

  9. The Gore-Tex Suture in Periareolar Closure: A Modified Closure Technique.

    Science.gov (United States)

    Chapman, Jade; Ingram, Scott

    2016-12-01

    In breast reduction and mastopexy procedures, the periareolar closure forms a vital component of the surgery. Periareolar closures completed with an absorbable suture may be prone to significant widening, hypertrophy and/or areolar distortion. In an effort to avoid this, some surgeons use a non-absorbable/permanent suture material [Franco (Arch Plast Surg 41 (6): 728-733, 2014)]. Hammond (Plast Reconstr Surg 119 (3):804-809, 2007) recommends the use of a Gore-Tex® suture for this purpose in view of the supple, pliable nature of the material; however, there remain at least occasional instances of infection and extrusion of the knot used to tie off the Gore-Tex "purse-string" [Franco (Arch Plast Surg 41 (6): 728-733, 2014); Salgarello (Aesthet Plast Surg 37 (5):1061-1062, 2013)]. We describe a method of securing the suture ends, which avoids the creation of a bulky knot, thus minimising the risk of infection and suture extrusion. Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

  10. CLOSURE REPORT FOR CORRECTIVE ACTION UNIT 528: POLYCHLORINATED BIPHENYLS CONTAMINATION NEVADA TEST SITE, NEVADA

    Energy Technology Data Exchange (ETDEWEB)

    BECHTEL NEVADA

    2006-09-01

    This Closure Report (CR) describes the closure activities performed at CAU 528, Polychlorinated Biphenyls Contamination, as presented in the Nevada Division of Environmental Protection (NDEP)-approved Corrective Action Plan (CAP) (US. Department of Energy, National Nuclear Security Administration Nevada Site Office [NNSAINSO], 2005). The approved closure alternative was closure in place with administrative controls. This CR provides a summary of the completed closure activities, documentation of waste disposal, and analytical data to confirm that the remediation goals were met.

  11. CLOSURE REPORT FOR CORRECTIVE ACTION UNIT 528: POLYCHLORINATED BIPHENYLS CONTAMINATION NEVADA TEST SITE, NEVADA

    Energy Technology Data Exchange (ETDEWEB)

    BECHTEL NEVADA

    2006-09-01

    This Closure Report (CR) describes the closure activities performed at CAU 528, Polychlorinated Biphenyls Contamination, as presented in the Nevada Division of Environmental Protection (NDEP)-approved Corrective Action Plan (CAP) (US. Department of Energy, National Nuclear Security Administration Nevada Site Office [NNSAINSO], 2005). The approved closure alternative was closure in place with administrative controls. This CR provides a summary of the completed closure activities, documentation of waste disposal, and analytical data to confirm that the remediation goals were met.

  12. Closure versus non-closure of the peritoneum at caesarean section: short- and long-term outcomes

    OpenAIRE

    Bamigboye, Anthony A; Hofmeyr, G Justus

    2014-01-01

    Background Caesarean section is a very common surgical procedure worldwide. Suturing the peritoneal layers at caesarean section may or may not confer benefit, hence the need to evaluate whether this step should be omitted or routinely performed. Objectives The objective of this review was to assess the effects of non-closure as an alternative to closure of the peritoneum at caesarean section on intraoperative and immediate- and long-term postoperative outcomes. Search methods We searched the ...

  13. 216-B-3 expansion ponds closure plan

    Energy Technology Data Exchange (ETDEWEB)

    1994-10-01

    This document describes the activities for clean closure under the Resource Conservation and Recovery Act of 1976 (RCRA) of the 216-B-3 Expansion Ponds. The 216-B-3 Expansion Ponds are operated by the US Department of Energy, Richland Operations Office (DOE-RL) and co-operated by Westinghouse Hanford Company (Westinghouse Hanford). The 216-B-3 Expansion Ponds consists of a series of three earthen, unlined, interconnected ponds that receive waste water from various 200 East Area operating facilities. The 3A, 3B, and 3C ponds are referred to as Expansion Ponds because they expanded the capability of the B Pond System. Waste water (primarily cooling water, steam condensate, and sanitary water) from various 200 East Area facilities is discharged to the Bypass pipe (Project X-009). Water discharged to the Bypass pipe flows directly into the 216-B-3C Pond. The ponds were operated in a cascade mode, where the Main Pond overflowed into the 3A Pond and the 3A Pond overflowed into the 3C Pond. The 3B Pond has not received waste water since May 1985; however, when in operation, the 3B Pond received overflow from the 3A Pond. In the past, waste water discharges to the Expansion Ponds had the potential to have contained mixed waste (radioactive waste and dangerous waste). The radioactive portion of mixed waste has been interpreted by the US Department of Energy (DOE) to be regulated under the Atomic Energy Act of 1954; the dangerous waste portion of mixed waste is regulated under RCRA.

  14. Microwave Tissue Soldering for Immediate Wound Closure

    Science.gov (United States)

    Arndt, G. Dickey; Ngo, Phong H.; Phan, Chau T.; Byerly, Diane; Dusl, John; Sognier, Marguerite A.; Carl, James

    2011-01-01

    A novel approach for the immediate sealing of traumatic wounds is under development. A portable microwave generator and handheld antenna are used to seal wounds, binding the edges of the wound together using a biodegradable protein sealant or solder. This method could be used for repairing wounds in emergency settings by restoring the wound surface to its original strength within minutes. This technique could also be utilized for surgical purposes involving solid visceral organs (i.e., liver, spleen, and kidney) that currently do not respond well to ordinary surgical procedures. A miniaturized microwave generator and a handheld antenna are used to deliver microwave energy to the protein solder, which is applied to the wound. The antenna can be of several alternative designs optimized for placement either in contact with or in proximity to the protein solder covering the wound. In either case, optimization of the design includes the matching of impedances to maximize the energy delivered to the protein solder and wound at a chosen frequency. For certain applications, an antenna could be designed that would emit power only when it is in direct contact with the wound. The optimum frequency or frequencies for a specific application would depend on the required depth of penetration of the microwave energy. In fact, a computational simulation for each specific application could be performed, which would then match the characteristics of the antenna with the protein solder and tissue to best effect wound closure. An additional area of interest with potential benefit that remains to be validated is whether microwave energy can effectively kill bacteria in and around the wound. Thus, this may be an efficient method for simultaneously sterilizing and closing wounds.

  15. CLOSURE OF HLW TANKS FORMULATION FOR A COOLING COIL GROUT

    Energy Technology Data Exchange (ETDEWEB)

    Harbour, J; Vickie Williams, V; Erich Hansen, E

    2008-05-23

    The Tank Closure and Technology Development Groups are developing a strategy for closing the High Level Waste (HLW) tanks at the Savannah River Site (SRS). Two Type IV tanks, 17 and 20 in the F-Area Tank Farm, have been successfully filled with grout. Type IV tanks at SRS do not contain cooling coils; on the other hand, the majority of the tanks (Type I, II, III and IIIA) do contain cooling coils. The current concept for closing tanks equipped with cooling coils is to pump grout into the cooling coils to prevent pathways for infiltrating water after tank closure. This task addresses the use of grout to fill intact cooling coils present in most of the remaining HLW tanks on Site. The overall task was divided into two phases. Phase 1 focused on the development of a grout formulation (mix design) suitable for filling the HLW tank cooling coils. Phase 2 will be a large-scale demonstration of the filling of simulated cooling coils under field conditions using the cooling coil grout mix design recommended from Phase 1. This report summarizes the results of Phase 1, the development of the cooling coil grout formulation. A grout formulation is recommended for the full scale testing at Clemson Environmental Technology Laboratory (CETL) that is composed by mass of 90% Masterflow (MF) 816 (a commercially available cable grout) and 10% blast furnace slag, with a water to cementitious material (MF 816 + slag) ratio of 0.33. This formulation produces a grout that meets the fresh and cured grout requirements detailed in the Task Technical Plan (2). The grout showed excellent workability under continuous mixing with minimal change in rheology. An alternative formulation using 90% MF 1341 and 10% blast furnace slag with a water to cementitious material ratio of 0.29 is also acceptable and generates less heat per gram than the MF 816 plus slag mix. However this MF 1341 mix has a higher plastic viscosity than the MF 816 mix due to the presence of sand in the MF 1341 cable grout and a

  16. Fracture mechanics analyses of partial crack closure in shell structures

    Science.gov (United States)

    Zhao, Jun

    2007-12-01

    This thesis presents the theoretical and finite element analyses of crack-face closure behavior in shells and its effect on the stress intensity factor under a bending load condition. Various shell geometries, such as spherical shell, cylindrical shell containing an axial crack, cylindrical shell containing a circumferential crack and shell with double curvatures, are all studied. In addition, the influence of material orthotropy on the crack closure effect in shells is also considered. The theoretical formulation is developed based on the shallow shell theory of Delale and Erdogan, incorporating the effect of crack-face closure at the compressive edges. The line-contact assumption, simulating the crack-face closure at the compressive edges, is employed so that the contact force at the closure edges is introduced, which can be translated to the mid-plane of the shell, accompanied by an additional distributed bending moment. The unknown contact force is computed by solving a mixed-boundary value problem iteratively, that is, along the crack length, either the normal displacement of the crack face at the compressive edges is equal to zero or the contact pressure is equal to zero. It is found that due to the curvature effects crack closure may not always occur on the entire length of the crack, depending on the direction of the bending load and the geometry of the shell. The crack-face closure influences significantly the magnitude of the stress intensity factors; it increases the membrane component but decreases the bending component. The maximum stress intensity factor is reduced by the crack-face closure. The significant influence of geometry and material orthotropy on rack closure behavior in shells is also predicted based on the analytical solutions. Three-dimensional FEA is performed to validate the theoretical solutions. It demonstrates that the crack face closure occurs actually over an area, not on a line, but the theoretical solutions of the stress intensity

  17. Epithelial gap closure governed by forces and geometry

    Science.gov (United States)

    Ladoux, Benoit

    The closure of gaps within epithelia is crucial to maintain the integrity and the homeostasis of the tissue during wound healing or cell extrusion processes. Cells mediate gap closure through either the assembly of multicellular actin-based contractile cables (purse-string contraction) or the protrusive activity of border cells into the gap (cell crawling). I will present experimental data and numerical modeling that show how these mechanisms can mutually interact to promote efficient epithelial gap closure and how mechanical constraints can regulate these mechanisms. I will first present how geometrical constraints dictate mechanisms of epithelial gap closure. We determine the importance of tissue shape during closure and the role of curvature of cell boundaries in this process. An essential difference between the two closure mechanisms is that cell crawling always pulls the edge of the tissue forward (i.e. towards the gap) while purse string pulls the edge forward or backwards depending on the local geometry. Our study demonstrates how the interplay between these two mechanisms is crucial for closing gaps and wounds, which naturally come in arbitrary shapes. Then I will focus on epithelial closure mechanism during cell extrusion. Within confluent cell layers, cellular motions coupled between neighbors are tightly regulated by the packing density of the epithelium inducing drastic changes in the dynamics of these tissues. I will show how cell density and tissue mechanics regulate the extrusion of cells within a confluent epithelial cell sheet, simultaneously measuring collective movements and traction forces. Epithelial packing and collective cell dynamics dictate the modes of cellular extrusions from lamellipodia crawling of the neighboring cells at low densities to coordinated actin-based contractile purse-string mechanism at higher density.

  18. Long-term cavity closure in non-linear rocks

    Science.gov (United States)

    Cornet, Jan; Dabrowski, Marcin; Schmid, Daniel Walter

    2017-08-01

    The time dependent closure of pressurized cavities in viscous rocks due to far-field loads is a problem encountered in many applications like drilling, cavity abandonment and porosity closure. The non-linear nature of the flow of rocks prevents the use of simple solutions for hole closure and calls for the development of appropriate expressions reproducing all the dependencies observed in nature. An approximate solution is presented for the closure velocity of a pressurized cylindrical cavity in a non-linear viscous medium subjected to a combined pressure and shear stress load in the far field. The embedding medium is treated as homogeneous, isotropic, and incompressible and follows a Carreau viscosity model. We derive analytical solutions for the end-member cases of the pressure and shear loads. The exact analytical solution for pressure loads shows that the closure velocity vR is given by the implicit expression {Δ p}/{2{μ _0D_{II}^*}} = - 1/2B( {{v_R^2}/{RD_{II^* + v_R^2}};1/2, - 1/{2n}} ), where Δp is the pressure load, R is the hole radius, B is the incomplete beta function, and μ0, D_{II}^*, n are, respectively, the threshold viscosity, transition rate and stress exponent of the Carreau model. The closure velocity is dominated by the linear mechanism under pressure loads smaller than 1.8{μ _0}D_{II}^* and by the non-linear one under large pressure loads. In the non-linear regime, pressure variations support an increasing part of the load with increasing degree of non-linearity. The decay of the stress perturbation in the non-linear zone varies as r- 2/n where r is the radial distance to the hole. A solution for the maximum closure velocity at the cavity rim vRmax under far-field shear is given: v_{R\\max} = ( 1 + {\\overline {M_s}} ^{-1/2})R\\overline D_{II}, where \\overline {M_s} = (1 + {\\overline {D_{II}} }^2 \\big/ {nD{_{II}^*}^2}) \\big/ ( 1 + {\\overline {D_{II}}^2} \\big/ D{_{II}^*}^2) and \\overline {D_{II}} is the second invariant of the far

  19. Fatigue testing of three peristernal median sternotomy closure techniques

    Directory of Open Access Journals (Sweden)

    Griffin Lanny V

    2008-09-01

    Full Text Available Abstract Background Failure of a sternotomy closure because of closure system fatigue is a complication that may result in dehiscence and put the individual at risk for serious complications. The purpose of this study was to assess the fatigue performance of three peristernal median sternotomy closure techniques (figure-of-eight stainless-steel wires, figure-of-eight stainless-steel cables, or Pectofix Dynamic Sternal Fixation [DSF] stainless-steel plates in order to quantify the potential risk of fatigue failure of these devices when subject to cyclic loads in physiologically relevant loading directions. Study Design All tests were conducted on polyurethane foam sternal models. A cardiothoracic surgeon divided each sternal model longitudinally and repaired it with a closure device. Tests were performed using a materials testing system that applied cyclic loading in a uniaxial direction until the test model catastrophically broke or data run-out occurred. For each loading direction (lateral distraction and longitudinal shear, five trials of each closure technique were tested. Life data and location of device failure (if present were evaluated. Statistical analysis was performed using regression with life data allowed for correlation between life data and the various closure techniques to develop risk assessment curves for each device. Results The data show that the figure-of-eight stainless-steel cable and the DSF plate systems are considerably less likely to fail under both lateral distraction and longitudinal shear cyclic loading conditions as compared to the figure-of-eight stainless-steel wire system. Moreover, the figure-of-eight stainless-steel cable system is the most resistant to failure, particularly for high cycle counts. Conclusion This study in addition to Cohen and Griffin's earlier published biomechanical comparison of the ultimate strength of these same three closure techniques provide extensive experimental evidence regarding the

  20. Transcatheter Closure of Patent Ductus Arteriosus: The Penang Hospital's Experience.

    Science.gov (United States)

    Amir Hamzah, A R; Tiow, C A; Koh, G T; Sharifah, A M

    2011-03-01

    Transcatheter closure of small and moderate sizes of Patent Ductus Arteriosus (PDA) is a standard and well accepted form of treatment. The aim of this study is to describe the experience of transcatheter closure of PDA in Penang Hospital. All patients who underwent transcatheter closure of PDA at our institution between 20th January 2006 and 27th June 2008 were retrospectively identified and studied. There were a total of 66 patients who had undergone transcatheter closure of PDA during this period which comprised of 24 male and 42 female. The PDA was closed by Amplatzer Duct Occluder (ADO) in 31 patients, Gianturco coil in 29 patients and other types of devices in 6 patients. There were 4 patients (6%) who had developed acute complication during the procedure (3 of them developed coil embolization and 1 had bleeding from puncture site). The PDA was successfully close in 95.5% of the study population without any residual PDA shunting. All the patients were alive but 5 of them (4.5%) have some abnormalities (2 has mild left pulmonary stenosis, 3 has small residual). Comparison between ADO and Gianturco coil revealed no significant difference in the outcome. Transcatheter closure of PDA has proven to be safe and effective with good midterm outcome. There was no significant difference between Amplatzer Ductal Occluder and Gianturco coil in term of the outcome.