Science.gov

Sample records for advanced ducted propulsor

  1. Cruise noise measurements of a scale model advanced ducted propulsor

    NASA Technical Reports Server (NTRS)

    Dittmar, James H.; Hughes, Christopher E.; Bock, Lawrence A.; Hall, David G.

    1993-01-01

    A scale model Advanced Ducted Propulsor (ADP) was tested in NASA Lewis Research Center's 8- by 6-Foot Wind Tunnel to obtain acoustic data at cruise conditions. The model, designed and manufactured by Pratt & Whitney Division of United Technologies, was tested with three inlet lengths. The model has 16 rotor blades and 22 stator vanes, which results in a cut-on condition with respect to rotor-stator interaction noise. Comparisons of the noise directivity of the ADP with that of a previously tested high-speed, unducted propeller showed that the ADP peak blade passing tone was about 30 dB below that of the propeller, and therefore, should not present a cabin or enroute noise problem. The maximum blade passing tone first increased with increasing helical tip Mach number, peaked, and then decreased at a higher Mach number. The ADP tests with the shortest inlet showed more noise in the inlet arc than did tests with either of the other two inlet lengths.

  2. Pratt & Whitney Advanced Ducted Propulsor (ADP) Engine Test in 40x80ft w.t.: Engineers Peter

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Pratt & Whitney Advanced Ducted Propulsor (ADP) Engine Test in 40x80ft w.t.: Engineers Peter Zell (left) and Dr Clifton Horne (right) are shown preparing a laser light sheet for a flow visualization test. Shown standing in the nacelle of the ADP is John Girvin, senior test engineer for Pratt & Whitney.

  3. Pratt & Whitney Advanced Ducted Propulsor (ADP) Engine Test in 40x80ft w.t.: Engineers Peter

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Pratt & Whitney Advanced Ducted Propulsor (ADP) Engine Test in 40x80ft w.t.: Engineers Peter Zell (left) and Dr Clifton Horne (right) are shown preparing for a laser light sheet for a flow visualization test. Shown standing in the nacelle of the ADP is John Girvin, senior test engineer for Pratt & Whitney.

  4. Some Acoustic Results from the Pratt and Whitney Advanced Ducted Propulsor: Fan 1

    NASA Technical Reports Server (NTRS)

    Dittmar, James H.; Elliott, David M.; Bock, Lawrence A.

    1999-01-01

    Noise measurements were obtained for the Advanced Ducted Propulsor (ADP) - Fan 1, with and without nacelle acoustic treatment. The fan was tested with no acoustic treatment (hard wall) and with acoustic treatment installed in three configurations in the nacelle (mid, mid plus aft, fully treated). The hard wall results showed that the radiated noise from the fan came primarily from the aft end of the nacelle. At takeoff and higher speeds, the noise measured at the inlet angles was also found to be dominated by noise from the aft end. Significant amounts of attenuation were observed with acoustic treatment installed and comparison with predictions showed the treatment gave more attenuation than predicted. Effective Perceived Noise Levels were determined for a large hypothetical 4 engine airplane. These levels showed that the installed acoustic treatment provided as much as 5 EPNdB of noise reduction. A traverse with a probe having three microphones, one above the other, showed azimuthal variations in the noise that need to be further investigated.

  5. Internal Acoustics Measurements of a Full Scale Advanced Ducted Propulsor Demonstrator

    NASA Technical Reports Server (NTRS)

    Santa Maria, O. L.; Soderman, P. T.; Horne, W. C.; Jones, M. G.; Bock, L. A.

    1995-01-01

    Acoustics measurements of a Pratt & Whitney full-scale ADP (Advanced Ducted Propulsor), an ultrahigh by-pass ratio engine, were conducted in the NASA Ames 40- by 80-Foot Wind Tunnel. This paper presents data from measurements taken from sensors on a fan exit guide vane in the ADP. Data from two sensors, one at mid-span and the other at the tip of the fan exit guide vane, are presented. At the blade passage frequency (BPF), the levels observed at the various engine and wind speeds were higher at the mid-span sensor than the tip sensor. The coherence between these internal sensors and external microphones were calculated and plotted as a function of angle (angles ranged from 5 degrees to 160 degrees) relative to the ADP longitudinal axis. At the highest engine and wind speeds, the coherence between the tip sensor and the external microphones was observed to decrease at higher multiples of the BPF. These results suggest that the rotor-stator interaction tones are stronger in the mid-span region than at the tip.

  6. Computational Aerodynamic Simulations of an 840 ft/sec Tip Speed Advanced Ducted Propulsor Fan System Model for Acoustic Methods Assessment and Development

    NASA Technical Reports Server (NTRS)

    Tweedt, Daniel L.

    2014-01-01

    Computational Aerodynamic simulations of an 840 ft/sec tip speed, Advanced Ducted Propulsor fan system were performed at five different operating points on the fan operating line, in order to provide detailed internal flow field information for use with fan acoustic prediction methods presently being developed, assessed and validated. The fan system is a sub-scale, lownoise research fan/nacelle model that has undergone extensive experimental testing in the 9- by 15- foot Low Speed Wind Tunnel at the NASA Glenn Research Center, resulting in quality, detailed aerodynamic and acoustic measurement data. Details of the fan geometry, the computational fluid dynamics methods, the computational grids, and various computational parameters relevant to the numerical simulations are discussed. Flow field results for three of the five operating conditions simulated are presented in order to provide a representative look at the computed solutions. Each of the five fan aerodynamic simulations involved the entire fan system, excluding a long core duct section downstream of the core inlet guide vane. As a result, only fan rotational speed and system bypass ratio, set by specifying static pressure downstream of the core inlet guide vane row, were adjusted in order to set the fan operating point, leading to operating points that lie on a fan operating line and making mass flow rate a fully dependent parameter. The resulting mass flow rates are in good agreement with measurement values. The computed blade row flow fields for all five fan operating points are, in general, aerodynamically healthy. Rotor blade and fan exit guide vane flow characteristics are good, including incidence and deviation angles, chordwise static pressure distributions, blade surface boundary layers, secondary flow structures, and blade wakes. Examination of the computed flow fields reveals no excessive boundary layer separations or related secondary-flow problems. A few spanwise comparisons between

  7. Model ducted propulsor noise characteristics at takeoff conditions

    NASA Technical Reports Server (NTRS)

    Woodward, Richard P.; Bock, Lawrence A.; Heidelberg, Laurence J.; Hall, David G.

    1994-01-01

    A model Advanced Ducted Propulsor (ADP) was tested in the NASA Lewis Low-Speed Anechoic Wind Tunnel at a simulated takeoff velocity of Mach 0.2. The model was designed and manufactured by Pratt & Whitney. The 16-blade rotor ADP was tested with 22- and 40-vane stators to achieve cut-on and cut-off criterion with respect to propagation of the fundamental rotor-stator interaction tone. Additional test parameters included three inlet lengths, three nozzle sizes, two spinner configurations, and two rotor rub strip configurations. The model was tested over a range of rotor blade setting angles and inlet angles of attack. Acoustic data were taken with a sideline translating microphone probe and with a unique inlet microphone probe that identified inlet rotating acoustic modes. The beneficial acoustic effects of cut-off were clearly demonstrated. A 10-dB fundamental tone reduction was associated with the long inlet and 40-vane stator. The fundamental tone level was essentially unaffected by inlet angle of attack at rotor speeds of above 96% design.

  8. Investigation of Pneumatic Inlet and Diffuser Blowing on a Ducted Fan Propulsor in Static Thrust Operation

    NASA Technical Reports Server (NTRS)

    Kondor, Shayne; Englar, Robert J.; Lee, Warren J.

    2003-01-01

    Tilting ducted fans present a solution for the lifting and forward flight propulsion requirements of VTOL aircraft. However, the geometry of the duct enshrouding the propeller has great a effect on the efficiency of the fan in various flight modes. Shroud geometry controls the velocity and pressure at the face of the fan, while maintaining a finite loading out at the tips of the fan blades. A duct tailored for most efficient generation of static lifting thrust will generally suffer from performance deficiencies in forward flight. The converse is true as well, leaving the designer with a difficult trade affecting the overall performance and sizing of the aircraft. Ideally, the shroud of a vertical lifting fan features a generous bell mouth inlet promoting acceleration of flow into the face of the fan, and terminating in a converging nozzle at the exit. Flow entering the inlet is accelerated into the fan by the circulation about the shroud, resulting in an overall increase in thrust compared to an open propeller operating under the same conditions . The accelerating shroud design is often employed in lifting ducted fans to benefit from the thrust augmentation; however, such shroud designs produce significant drag penalties in axial flight, thus are unsuitable for efficient forward flight applications. Decelerating, or diffusing, duct designs are employed for higher speed forward flight configurations. The lower circulation on the shroud tends to decelerate the flow into the face of the fan, which is detrimental to static thrust development; however, net thrust is developed on the shroud while the benefits of finite blade loading are retained. With judicious shroud design for intended flight speeds, a net increase in efficiency can be obtained over an open propeller. In this experiment, conducted under contract to NASA LaRC (contract NAG-1-02093) circulation control is being applied to a mildly diffusing shroud design, intended for improved forward flight performance

  9. Advanced Duct Sealing Testing

    SciTech Connect

    Sherman, Max H.; Walker, Iain S.

    2003-08-01

    Duct leakage has been identified as a major source of energy loss in residential buildings. Most duct leakage occurs at the connections to registers, plenums or branches in the duct system. At each of these connections a method of sealing the duct system is required. Typical sealing methods include tapes or mastics applied around the joints in the system. Field examinations of duct systems have typically shown that these seals tend to fail over extended periods of time. The Lawrence Berkeley National Laboratory has been testing sealant durability for several years. Typical duct tape (i.e. fabric backed tapes with natural rubber adhesives) was found to fail more rapidly than all other duct sealants. This report summarizes the results of duct sealant durability testing of five UL 181B-FX listed duct tapes (three cloth tapes, a foil tape and an Oriented Polypropylene (OPP) tape). One of the cloth tapes was specifically developed in collaboration with a tape manufacturer to perform better in our durability testing. The first test involved the aging of common ''core-to-collar joints'' of flexible duct to sheet metal collars, and sheet metal ''collar-to-plenum joints'' pressurized with 200 F (93 C) air. The second test consisted of baking duct tape specimens in a constant 212 F (100 C) oven following the UL 181B-FX ''Temperature Test'' requirements. Additional tests were also performed on only two tapes using sheet metal collar-to-plenum joints. Since an unsealed flexible duct joint can have a variable leakage depending on the positioning of the flexible duct core, the durability of the flexible duct joints could not be based on the 10% of unsealed leakage criteria. Nevertheless, the leakage of the sealed specimens prior to testing could be considered as a basis for a failure criteria. Visual inspection was also documented throughout the tests. The flexible duct core-to-collar joints were inspected monthly, while the sheet metal collar-to-plenum joints were inspected

  10. Tradespace Exploration of Distributed Propulsors for Advanced On-Demand Mobility Concepts

    NASA Technical Reports Server (NTRS)

    Borer, Nicholas K.; Moore, Mark D.; Turnbull, Andrew R.

    2014-01-01

    Combustion-based sources of shaft power tend to significantly penalize distributed propulsion concepts, but electric motors represent an opportunity to advance the use of integrated distributed propulsion on an aircraft. This enables use of propellers in nontraditional, non-thrust-centric applications, including wing lift augmentation, through propeller slipstream acceleration from distributed leading edge propellers, as well as wingtip cruise propulsors. Developing propellers for these applications challenges long-held constraints within propeller design, such as the notion of optimizing for maximum propulsive efficiency, or the use of constant-speed propellers for high-performance aircraft. This paper explores the design space of fixed-pitch propellers for use as (1) lift augmentation when distributed about a wing's leading edge, and (2) as fixed-pitch cruise propellers with significant thrust at reduced tip speeds for takeoff. A methodology is developed for evaluating the high-level trades for these types of propellers and is applied to the exploration of a NASA Distributed Electric Propulsion concept. The results show that the leading edge propellers have very high solidity and pitch well outside of the empirical database, and that the cruise propellers can be operated over a wide RPM range to ensure that thrust can still be produced at takeoff without the need for a pitch change mechanism. To minimize noise exposure to observers on the ground, both the leading edge and cruise propellers are designed for low tip-speed operation during takeoff, climb, and approach.

  11. Advanced Turbofan Duct Liner Concepts

    NASA Technical Reports Server (NTRS)

    Bielak, Gerald W.; Premo, John W.; Hersh, Alan S.

    1999-01-01

    The Advanced Subsonic Technology Noise Reduction Program goal is to reduce aircraft noise by 10 EPNdB by the year 2000 relative, to 1992 technology. The improvement goal for nacelle attenuation is 25% relative to 1992 technology by 1997 and 50% by 2000. The Advanced Turbofan Duct Liner Concepts Task work by Boeing presented in this document was in support of these goals. The basis for the technical approach was a Boeing study conducted in 1993-94 under NASA/FAA contract NAS1-19349, Task 6, investigating broadband acoustic liner concepts. As a result of this work, it was recommended that linear double layer, linear and perforate triple layer, parallel element, and bulk absorber liners be further investigated to improve nacelle attenuations. NASA LaRC also suggested that "adaptive" liner concepts that would allow "in-situ" acoustic impedance control also be considered. As a result, bias flow and high-temperature liner concepts were also added to the investigation. The major conclusion from the above studies is that improvements in nacelle liner average acoustic impedance characteristics alone will not result in 25% increased nacelle noise reduction relative to 1992 technology. Nacelle design advancements currently being developed by Boeing are expected to add 20-40% more acoustic lining to hardwall regions in current inlets, which is predicted to result in and additional 40-80% attenuation improvement. Similar advancements are expected to allow 10-30% more acoustic lining in current fan ducts with 10-30% more attenuation expected. In addition, Boeing is currently developing a scarf inlet concept which is expected to give an additional 40-80% attenuation improvement for equivalent lining areas.

  12. A Non-linear Lifting Line Model for Design and Analysis of Trochoidal Propulsors

    NASA Astrophysics Data System (ADS)

    Roesler, Bernard; Epps, Brenden

    2014-11-01

    Flapping wing propulsors may increase the propulsive efficiency of large shipping vessels. A comparison of the design of a notional propulsor for a large shipping vessel with (a) a conventional ducted propeller versus (b) a flapping wing propulsor is presented. Calculations for flapping wing propulsors are performed using an open-source MATLAB software suite developed by the authors, CyROD, implementing an unsteady lifting-line model with free vortex wake roll-up to study the non-linear effects of foil-wake, and foil-foil interactions. Improvements to the traditional lifting line theory are made using further discretization of the wake vortex ring spacing near the trailing edge. Considerations of packaging options for a flapping wing propulsor on a large shipping vessel are presented, and compared with those for a conventional ducted propeller.

  13. Counterrotating aircraft propulsor blades

    NASA Technical Reports Server (NTRS)

    Nelson, Joey L. (Inventor); Elston, III, Sidney B. (Inventor); Tseng, Wu-Yang (Inventor); Hemsworth, Martin C. (Inventor)

    1993-01-01

    A propulsor blade for an aircraft engine includes an airfoil section formed in the shape of a scimitar. A metallic blade spar is interposed between opposed surfaces of the blade and is bonded to the surfaces to establish structural integrity of the blade. The metallic blade spar includes a root end allowing attachment of the blade to the engine.

  14. Counterrotating aircraft propulsor blades

    NASA Technical Reports Server (NTRS)

    Nelson, Joey L. (Inventor); Elston, III, Sidney B. (Inventor); Tseng, Wu-Yang (Inventor); Hemsworth, Martin C. (Inventor)

    1988-01-01

    A propulsor blade for an aircraft engine includes an airfoil section formed in the shape of a scimitar. A metallic blade spar is interposed between opposed surfaces of the blade and is bonded to the surfaces to establish structural integrity of the blade. The metallic blade spar includes a root end allowing attachment of the blade to the engine.

  15. Technology readiness for advanced ducted engines

    SciTech Connect

    Eckardt, D.; Brines, G.L.

    1989-01-01

    The Advanced Ducted Engines (ADEs) currently undergoing development for next-generation passenger aircraft typically possess bypass ratios of the order of 12-25 and specific fuel consumption figures 12-17 percent lower than current advanced turbofans. An extensive technology-readiness program has been mounted on behalf of ADE design definition over the last two years, encompassing among its concerns aircraft/engine-installation interference, low pressure-ratio fan aerodynamics, fan/nacelle interactions (including windmilling and thrust-reversal), acoustic characteristics, transonic-drive turbines, and slender nacelle aerodynamic and mechanical design. Both turbine-driven and geared ADE fans, which may be of single-rotating or contrarotating type, are discussed. 5 refs.

  16. Large Eddy Simulation of Crashback in Marine Propulsors

    NASA Astrophysics Data System (ADS)

    Jang, Hyunchul

    Crashback is an operating condition to quickly stop a propelled vehicle, where the propeller is rotated in the reverse direction to yield negative thrust. The crashback condition is dominated by the interaction of the free stream flow with the strong reverse flow. This interaction forms a highly unsteady vortex ring, which is a very prominent feature of crashback. Crashback causes highly unsteady loads and flow separation on the blade surface. The unsteady loads can cause propulsor blade damage, and also affect vehicle maneuverability. Crashback is therefore well known as one of the most challenging propeller states to analyze. This dissertation uses Large-Eddy Simulation (LES) to predict the highly unsteady flow field in crashback. A non-dissipative and robust finite volume method developed by Mahesh et al. (2004) for unstructured grids is applied to flow around marine propulsors. The LES equations are written in a rotating frame of reference. The objectives of this dissertation are: (1) to understand the flow physics of crashback in marine propulsors with and without a duct, (2) to develop a finite volume method for highly skewed meshes which usually occur in complex propulsor geometries, and (3) to develop a sliding interface method for simulations of rotor-stator propulsor on parallel platforms. LES is performed for an open propulsor in crashback and validated against experiments performed by Jessup et al. (2004). The LES results show good agreement with experiments. Effective pressures for thrust and side-force are introduced to more clearly understand the physical sources of thrust and side-force. Both thrust and side-force are seen to be mainly generated from the leading edge of the suction side of the propeller. This implies that thrust and side-force have the same source---the highly unsteady leading edge separation. Conditional averaging is performed to obtain quantitative information about the complex flow physics of high- or low-amplitude events. The

  17. Efficient, Low Pressure Ratio Propulsor for Gas Turbine Engines

    NASA Technical Reports Server (NTRS)

    Gallagher, Edward J. (Inventor); Monzon, Byron R. (Inventor)

    2015-01-01

    A gas turbine engine includes a spool, a turbine coupled to drive the spool, and a propulsor that is coupled to be driven by the turbine through the spool. A gear assembly is coupled between the propulsor and the spool such that rotation of the turbine drives the propulsor at a different speed than the spool. The propulsor includes a hub and a row of propulsor blades that extends from the hub. The row includes no more than 20 of the propulsor blades.

  18. Simulation of hydrodynamic performance of drag and double reverse propeller podded propulsors

    NASA Astrophysics Data System (ADS)

    Guo, Chunyu; Dou, Pengfei; Jing, Tao; Zhao, Dagang

    2016-03-01

    The unsteady performance of drag and double reverse propeller podded propulsors in open water was numerically simulated using a computational fluid dynamics (CFD) method. A moving mesh method was used to more realistically simulate propulsor working conditions, and the thrust, torque, and lateral force coefficients of both propulsors were compared and analyzed. Forces acting on different parts of the propulsors along with the flow field distribution of steady and unsteady results at different advance coefficients were compared. Moreover, the change of the lateral force and the difference between the abovementioned two methods were mainly analyzed. It was shown that the thrust and torque results of both methods were similar, with the lateral force results having the highest deviation

  19. Analysis of an advanced ducted propeller subsonic inlet

    NASA Technical Reports Server (NTRS)

    Iek, Chanthy; Boldman, Donald R.; Ibrahim, Mounir

    1992-01-01

    It is shown that a time marching Navier-Stokes code called PARC can be utilized to provide a reasonable prediction of the flow field within an inlet for an advanced ducted propeller. The code validation was implemented for a nonseparated flow condition associated with the inlet functioning at angles-of-attack of zero and 25 deg. Comparison of the computational results with the test data shows that the PARC code with the propeller face fixed flow properties boundary conditions (BC) provided a better prediction of the inlet surface static pressures than the prediction when the mass flow BC was employed.

  20. Management of nasolacrimal duct injuries in mid-facial advancement

    PubMed Central

    Balaji, S. M.

    2015-01-01

    Nasolacrimal duct (NLD) may be injured following trauma. During certain surgical procedure, inadvertent damage to the nasolacrimal apparatus may occur as well. Such instances should be immediately managed to prevent any subsequent complications. The management of such inadvertent injuries may be accomplished only with a thorough anatomic comprehension and surgical expertise in the field of operation. It also requires the presence of armamentarium required for its management in situations when complications arise. The case report discusses one such rare complication of NLD injury during Le Fort III osteotomy and advancement effectively managed by bicanalicular stenting. PMID:26389043

  1. Propulsion efficiencies of magnetohydrodynamic propulsors considering electrical and magnetic end effects. Research and development report

    SciTech Connect

    Beatty, P.A.; Hughes, W.F.; Brown, S.H.; Walters, J.D.; Sondergaard, N.A.

    1992-04-01

    A mathematical theory for the performance of a direct current, rectangular duct magnetohydrodynamic (MBD) propulsion system propelling a marine vehicle is presented. The model accounts for the effects of spatially nonuniform magnetic fields and current distributions which are present at the ends of the propulsion unit. The theory is based on an approximate solution of the general NM duct flow problem in which the mutual interaction of the electric current and fluid flow in a strong magnetic field are considered in detail. For a specified vehicular steady state cruising speed, the propulsive efficiency and electrical power requirements can be calculated from the theory given the hydrodynamic drag of the vehicle and the properties of the fluid medium. Explicit electrical end loss factors are calculated to relate the performance of a propulsor with nonuniform field distributions to the performance of an idealized propulsor with no end losses operating under the same conditions. The power losses due to auxiliary equipment such as electrical generators, buswork, and magnetic cryogenic systems are not included in the study. Numerical results from the models for five design configurations for a nominal geometry under a reasonable range of operating parameters are presented. The numerical results, including the ideal propulsor with no end effects, indicate that the fringing magnetic and current distributions at the ends of the duct generally significantly degrade the propulsive efficiency. The degree of degradation depends on details of the design configuration of the rectangular duct.

  2. Vortex interaction between two tandem flexible propulsors

    NASA Astrophysics Data System (ADS)

    Park, Sung Goon; Sung, Hyung Jin; Flow Control Laboratory Team

    2015-11-01

    Schooling behaviors of flying and swimming animals are widespread phenomena in nature. Inspired by schooling behaviors of swimming jellyfish, self-propelling flexible bodies with a paddling-based locomotion were modeled in a tandem configuration. The interactions between surrounding fluids and propulsors were considered by using the immersed boundary method. The hydrodynamic patterns generated by the interactions between tandem flexible propulsors were analyzed in the presen study. As a result of the flow-mediated interactions between them, stable configurations were formed spontaneously in which the gap distance between propulsors increased and decreased during the contraction and relaxation phases of the upstream propulsor. The stable configuration was not affected by the initial gap distance but influenced by the phase difference in the flapping frequency between them. Both tandem propulsors benefited from the tandem configuration in terms of the locomotion as compared with an isolated propulsor. This study was supported by the Creative Research Initiatives (No. 2015-001828) program of the National Research Foundation of Korea (MSIP).

  3. CPI-613 in Treating Patients With Advanced or Metastatic Bile Duct Cancer That Cannot Be Removed By Surgery

    ClinicalTrials.gov

    2015-12-28

    Adult Primary Cholangiocellular Carcinoma; Advanced Adult Primary Liver Cancer; Cholangiocarcinoma of the Extrahepatic Bile Duct; Cholangiocarcinoma of the Gallbladder; Localized Unresectable Adult Primary Liver Cancer; Metastatic Extrahepatic Bile Duct Cancer; Recurrent Adult Primary Liver Cancer; Recurrent Extrahepatic Bile Duct Cancer; Unresectable Extrahepatic Bile Duct Cancer

  4. Analysis of an advanced ducted propeller subsonic inlet

    NASA Technical Reports Server (NTRS)

    Iek, Chanthy; Boldman, Donald R.; Ibrahim, Mounir

    1992-01-01

    A time marching Navier-Stokes code called PARC (PARC2D for 2-D/axisymmetric and PARC3D for 3-D flow simulations) was validated for an advanced ducted propeller (ADP) subsonic inlet. The code validation for an advanced ducted propeller (ADP) subsonic inlet. The code validation was implemented for a non-separated flow condition associated with the inlet operating at angles-of-attack of 0 and 25 degrees. The inlet test data were obtained in the 9 x 15 ft Low Speed Wind Tunnel at NASA Lewis Research Center as part of a cooperative study with Pratt and Whitney. The experimental study focused on the ADP inlet performance for take-off and approach conditions. The inlet was tested at a free stream Mach number of 0.2, at angles-of-attack between O and 35 degrees, and at a maximum propeller speed of 12,000 RPM which induced a corrected air flow rate of about 46 lb/sec based on standard day conditions. The computational grid and flow boundary conditions (BC) were based on the actual inlet geometry and the funnel flow conditions. At the propeller face, two types of BC's were applied: a mass flow BC and a fixed flow properties BC. The fixed flow properties BC was based on a combination of data obtained from the experiment and calculations using a potential flow code. Comparison of the computational results with the test data indicates that the PARC code with the propeller face fixed flow properties BC provided a better prediction of the inlet surface static pressures than the predictions when the mass flow BC was used. For an angle-of-attack of 0 degrees, the PARC2D code with the propeller face mass flow BC provided a good prediction of inlet static pressures except in the region of high pressure gradient. With the propeller face fixed flow properties BC, the PARC2D code provided a good prediction of the inlet static pressures. For an angle-of-attack of 25 degrees with the mass flow BC, the PARC3D code predicted statis pressures which deviated significantly from the test data

  5. Advanced Strategy Guideline: Air Distribution Basics and Duct Design

    SciTech Connect

    Burdick, A.

    2011-12-01

    This report discusses considerations for designing an air distribution system for an energy efficient house that requires less air volume to condition the space. Considering the HVAC system early in the design process will allow adequate space for equipment and ductwork and can result in cost savings. Principles discussed that will maximize occupant comfort include delivery of the proper amount of conditioned air for appropriate temperature mixing and uniformity without drafts, minimization of system noise, the impacts of pressure loss, efficient return air duct design, and supply air outlet placement, as well as duct layout, materials, and sizing.

  6. Cladding and Duct Materials for Advanced Nuclear Recycle Reactors

    SciTech Connect

    Allen, Todd R.; Busby, Jeremy T; Klueh, Ronald L; Maloy, S; Toloczko, M

    2008-01-01

    The expanded use of nuclear energy without risk of nuclear weapons proliferation and with safe nuclear waste disposal is a primary goal of the Global Nuclear Energy Partnership (GNEP). To achieve that goal the GNEP is exploring advanced technologies for recycling spent nuclear fuel that do not separate pure plutonium, and advanced reactors that consume transuranic elements from recycled spent fuel. The GNEP s objectives will place high demands on reactor clad and structural materials. This article discusses the materials requirements of the GNEP s advanced nuclear recycle reactors program.

  7. Radial inflow gas turbine engine with advanced transition duct

    SciTech Connect

    Wiebe, David J

    2015-03-17

    A gas turbine engine (10), including: a turbine having radial inflow impellor blades (38); and an array of advanced transition combustor assemblies arranged circumferentially about the radial inflow impellor blades (38) and having inner surfaces (34) that are adjacent to combustion gases (40). The inner surfaces (34) of the array are configured to accelerate and orient, for delivery directly onto the radial inflow impellor blades (38), a plurality of discrete flows of the combustion gases (40). The array inner surfaces (34) define respective combustion gas flow axes (20). Each combustion gas flow axis (20) is straight from a point of ignition until no longer bound by the array inner surfaces (34), and each combustion gas flow axis (20) intersects a unique location on a circumference defined by a sweep of the radial inflow impellor blades (38).

  8. Cholangiocarcinoma and malignant bile duct obstruction: A review of last decades advances in therapeutic endoscopy

    PubMed Central

    Bertani, Helga; Frazzoni, Marzio; Mangiafico, Santi; Caruso, Angelo; Manno, Mauro; Mirante, Vincenzo Giorgio; Pigò, Flavia; Barbera, Carmelo; Manta, Raffaele; Conigliaro, Rita

    2015-01-01

    In the last decades many advances have been achieved in endoscopy, in the diagnosis and therapy of cholangiocarcinoma, however blood test, magnetic resonance imaging, computed tomography scan may fail to detect neoplastic disease at early stage, thus the diagnosis of cholangiocarcinoma is achieved usually at unresectable stage. In the last decades the role of endoscopy has moved from a diagnostic role to an invaluable therapeutic tool for patients affected by malignant bile duct obstruction. One of the major issues for cholangiocarcinoma is bile ducts occlusion, leading to jaundice, cholangitis and hepatic failure. Currently, endoscopy has a key role in the work up of cholangiocarcinoma, both in patients amenable to surgical intervention as well as in those unfit for surgery or not amenable to immediate surgical curative resection owing to locally advanced or advanced disease, with palliative intention. Endoscopy allows successful biliary drainage and stenting in more than 90% of patients with malignant bile duct obstruction, and allows rapid reduction of jaundice decreasing the risk of biliary sepsis. When biliary drainage and stenting cannot be achieved with endoscopy alone, endoscopic ultrasound-guided biliary drainage represents an effective alternative method affording successful biliary drainage in more than 80% of cases. The purpose of this review is to focus on the currently available endoscopic management options in patients with cholangiocarcinoma. PMID:26078827

  9. Flapping dynamics of a flexible propulsor near ground

    NASA Astrophysics Data System (ADS)

    Ryu, Jaeha; Park, Sung Goon; Kim, Boyoung; Sung, Hyung Jin

    2016-06-01

    The flapping motion of a flexible propulsor near the ground was simulated using the immersed boundary method. The hydrodynamic benefits of the propulsor near the ground were explored by varying the heaving frequency (St) of the leading edge of the flexible propulsor. Propulsion near the ground had some advantages in generating thrust and propelling faster than propulsion away from the ground. The mode analysis and flapping amplitude along the Lagrangian coordinate were examined to analyze the kinematics as a function of the ground proximity (d) and St. The trailing edge amplitude (a_tail ) and the net thrust (overline{{F}}_x ) were influenced by St of the flexible propulsor. The vortical structures in the wake were analyzed for different flapping conditions.

  10. Influence of fins on tractor-type podded propulsor performance

    NASA Astrophysics Data System (ADS)

    Xie, Xue-Shen; Huang, Sheng

    2009-09-01

    A mathematical model of podded propulsors was established in order to investigate the influence of fins. The hydrodynamic performance of podded propulsors with and without fins was calculated, with interactions between propellers and pods and fins derived by iterative calculation. The differential equation based on velocity potential was adopted and hyperboloidal panels were used to avoid gaps between surface panels. The Newton-Raphson iterative procedure was used on the trailing edge to meet the pressure Kutta condition. The velocity distribution was calculated with the Yanagizawa method to eliminate the singularity caused by use of the numerical differential. Comparisons of the performance of podded propulsors with different fins showed that the thrust of propeller in a podded propulsor with fins is greater. The resistance of the pod is also reduced because of the thrust of the fin. The hydrodynamic performance of a podded propulsor with two fins is found to be best, the performance of a podded propulsor with one fin is not as good as two fins, and the performance of the common type is the worst.

  11. Common Bile Duct Stones Detected After Cholecystectomy:Advancement into the Duodenum via the Percutaneous Route

    SciTech Connect

    Ozcan, Nevzat Erdogan, Nuri; Baskol, Mevlut

    2003-04-15

    Purpose: To report our experience in the use of percutaneous extraction of common bile duct stones detected in the post-cholecystectomy period. Methods: Forty-two patients in whom endoscopic cannulation and/or sphincterotomy had failed or could not be done due to several reasons underwent balloon dilatation of the ampulla of Vater and subsequent advancement of the stones via the percutaneous transhepatic route or T-tube tract. Results: The procedure was successful in 42 cases. In three patients, stones were crushed in the common bile duct and pushed as fragments into the duodenum. In all cases transient adverse effects were observed. There were no major complications. All cases were checked with ultrasonography for 6 months after the procedure. Conclusion: Percutaneous extraction of common bile duct stones is an effective method of treatment with a high success rate,low complication rate and shorter hospital stay. It may serve as an alternative method in cases where endoscopic removal of stones fails.

  12. Selumetinib and Akt Inhibitor MK-2206 in Treating Patients With Refractory or Advanced Gallbladder or Bile Duct Cancer That Cannot Be Removed By Surgery

    ClinicalTrials.gov

    2014-09-08

    Adenocarcinoma of the Gallbladder; Adenocarcinoma With Squamous Metaplasia of the Gallbladder; Adult Primary Cholangiocellular Carcinoma; Advanced Adult Primary Liver Cancer; Cholangiocarcinoma of the Extrahepatic Bile Duct; Localized Unresectable Adult Primary Liver Cancer; Metastatic Extrahepatic Bile Duct Cancer; Recurrent Adult Primary Liver Cancer; Recurrent Extrahepatic Bile Duct Cancer; Stage II Gallbladder Cancer; Stage IIIA Gallbladder Cancer; Stage IIIB Gallbladder Cancer; Stage IVA Gallbladder Cancer; Stage IVB Gallbladder Cancer; Unresectable Extrahepatic Bile Duct Cancer

  13. Performance-based design and analysis of flexible composite propulsors

    NASA Astrophysics Data System (ADS)

    Motley, Michael R.; Young, Yin L.

    2011-11-01

    Advanced composite propellers, turbines, and jet engines have become increasingly popular in part because of their ability to provide improved performance over traditional metallic rotors through exploitation of the intrinsic bend-twist coupling characteristics of anisotropic composite materials. While these performance improvements can be significant from a conceptual perspective, the load-dependent deformation responses of adaptive blades make the design of these structures highly non-trivial. Hence, it is necessary to understand and predict the dependence of the deformations on the geometry, material constitution, and fluid-structure interaction responses across the entire range of expected loading conditions.The objective of this work is to develop a probabilistic performance-based design and analysis methodology for flexible composite propulsors. To demonstrate the method, it is applied for the design and analysis of two (rigid) metallic and (flexible) composite propellers for a twin-shafted naval combatant craft. The probabilistic operational space is developed by considering the variation of vessel thrust requirements as a function of the vessel speed and wave conditions along with the probabilistic speed profiles. The performance of the metallic and composite propellers are compared and discussed. The implications of load-dependent deformations of the flexible composite propeller on the operating conditions and the resulting performance with respect to propeller efficiency, power demand, and fluid cavitation are presented for both spatially uniform and varying flows. While the proposed framework is demonstrated for marine propellers, the methodology can be generally applied for any marine, aerospace, or wind energy structure that must operate in a wide range of loading conditions over its expected life.

  14. Advanced in-duct sorbent injection for SO{sub 2} control. Final technical report

    SciTech Connect

    Stouffer, M.R.; Withium, J.A.; Rosenhoover, W.A.; Maskew, J.T.

    1994-12-01

    The objective of this research project was to develop a second generation duct sorbent injection technology as a cost-effective compliance option for the 1990 Clean Air Act Amendments. Research and development work was focused on the Advanced Coolside process, which showed the potential for exceeding the original performance targets of 90% SO{sub 2} removal and 60% sorbent utilization. Process development was conducted in a 1000 acfm pilot plant. The pilot plant testing showed that the Advanced Coolside process can achieve 90% SO{sub 2} removal at sorbent utilizations up to 75%. The testing also showed that the process has the potential to achieve very high removal efficiency (90 to >99%). By conducting conceptual process design and economic evaluations periodically during the project, development work was focused on process design improvements which substantially lowered process capital and operating costs, A final process economic study projects capital costs less than one half of those for limestone forced oxidation wet FGD. Projected total SO{sub 2} control cost is about 25% lower than wet FGD for a 260 MWe plant burning a 2.5% sulfur coal. A waste management study showed the acceptability of landfill disposal; it also identified a potential avenue for by-product utilization which should be further investigated. Based on the pilot plant performance and on the above economic projections, future work to scale up the Advanced Coolside process is recommended.

  15. Measurements of Forward Flight Effects on the Advanced Ducted Propulsion Demonstrator Engine

    NASA Technical Reports Server (NTRS)

    Horne, W. C.; Soderman, P. T.; Larkin, M.; Bock, L.; Olson, Lawrence (Technical Monitor)

    1994-01-01

    The performance of the Pratt & Whitney Advanced Ducted Propulsion (ADP) UHB concept has been recently evaluated with studies of a 17 in. diameter fan simulator. Following the model scale tests, a 118 in. diameter demonstrator was tested at the NASA Ames 40- by 80-Foot Wind Tunnel. The 18 blade fan was driven by the low compressor shaft of a PW2037 core through a reduction gear system fabricated by Fiat with approximately 1:3.7 reduction ratio. ne variable pitch fan was hydraulically actuated with settings for take-off, cruise, feather, and reverse thrust. The low-pressure turbine was built by MTU to provide higher shaft power in comparison with the standard PW2037. The demonstrator was provided with 45 vanes located 2.6 fan chords downstream of the rotor, and 10 case struts approximately 1 fan chord downstream of the vanes. The inlet, mid-duct, and exhaust linings were acoustically treated. Acoustic surveys were taken in the for-ward thrust mode for fan speeds of 898, 1120, 1205, and 1302 R.P.M., and at tunnel speeds of 25, 50, 100, and 140 kts. The lowest speed was achieved with the wind tunnel fans at flat pitch, but with the engine pumping the test section Microphone signals were recorded for 30 seconds at 5 deg. increments. These measurements will be used to assess the effects of forward speed on UHB engines, to compare these effects with the corresponding characteristics of conventional bypass ratio engines, and to discuss the various aspects of testing large engines in the wind tunnel.

  16. Cavitation studies on axi-symmetric underwater body with pumpjet propulsor in cavitation tunnel

    NASA Astrophysics Data System (ADS)

    Suryanarayana, Ch.; Satyanarayana, B.; Ramji, K.; Rao, M. Nageswara

    2010-12-01

    A pumpjet propulsor (PJP) was designed for an underwater body (UWB) with axi-symmetric configuration. Its performance was predicted through CFD study and models were manufactured. The propulsor design was evaluated for its propulsion characteristics through model tests conducted in a Wind Tunnel (WT). In the concluding part of the study, evaluation of the cavitation performance of the pumpjet was undertaken in a cavitation tunnel (CT). In order to assess the cavitation free operation speeds and depths of the body, cavitation tests of the PJP were carried out in behind condition to determine the inception cavitation numbers for rotor, stator and cowl. The model test results obtained were corrected for full scale Reynolds number and subsequently analyzed for cavitation inception speeds at different operating depths. From model tests it was also found that the cavitation inception of the rotor takes place on the tip face side at higher advance ratios and cavitation shifts towards the suction side as the RPS increases whereas the stator and cowl are free from cavitation.

  17. Investigation of Advanced Counterrotation Blade Configuration Concepts for High Speed Turboprop Systems. Task 2: Unsteady Ducted Propfan Analysis

    NASA Technical Reports Server (NTRS)

    Hall, Edward J.; Delaney, Robert A.; Bettner, James L.

    1991-01-01

    The primary objective was the development of a time dependent 3-D Euler/Navier-Stokes aerodynamic analysis to predict unsteady compressible transonic flows about ducted and unducted propfan propulsion systems at angle of attack. The resulting computer codes are referred to as Advanced Ducted Propfan Analysis Codes (ADPAC). A computer program user's manual is presented for the ADPAC. Aerodynamic calculations were based on a four stage Runge-Kutta time marching finite volume solution technique with added numerical dissipation. A time accurate implicit residual smoothing operator was used for unsteady flow predictions. For unducted propfans, a single H-type grid was used to discretize each blade passage of the complete propeller. For ducted propfans, a coupled system of five grid blocks utilizing an embedded C grid about the cowl leading edge was used to discretize each blade passage. Grid systems were generated by a combined algebraic/elliptic algorithm developed specifically for ducted propfans. Numerical calculations were compared with experimental data for both ducted and unducted flows.

  18. Experimental evaluation of pumpjet propulsor for an axi-symmetric body in wind tunnel

    NASA Astrophysics Data System (ADS)

    Suryanarayana, Ch.; Satyanarayana, B.; Ramji, K.; Saiju, A.

    2010-03-01

    Design of a Pump-Jet Propulsor (PJP) was undertaken for an underwater body with axi-symmetric configuration using axial flow compressor design techniques supported by CFD analysis for performance prediction. Experimental evaluation of the PJP was carried out through experiments in Wind Tunnel Facility (WTF) using momentum defect principle for propulsive performance prior to proceeding with extensive experimental evaluation in towing tank and cavitation tunnel. Experiments were particularly conducted with respect to Self Propulsion Point (SPP), residual torque and thrust characteristics over a range of vehicle advance ratio in order to ascertain whether sufficient thrust is developed at the design condition with least possible imbalance torque left out due to residual swirl in the slip stream. Pumpjet and body models were developed for the propulsion tests using Aluminium alloy forged material. Tests were conducted from 0 m/s to 30 m/s at four rotational speeds of the PJP. SPP was determined confirming the thrust development capability of PJP. Estimation of residual torque was carried out at SPP corresponding to speeds of 15, 20 and 25 m/s to examine the effectiveness of the stator. Estimation of thrust and residual torque was also carried out at wind speeds 0 and 6 m/s for PJP RPMs corresponding to self propulsion tests to study the propulsion characteristics during the launch of the vehicle in water where advance ratios are close to Zero. These results are essential to assess the thrust performance at very low advance ratios to accelerate the body and to control the body during initial stages. This technique has turned out to be very useful and economical method for quick assessment of overall performance of the propulsor and generation of exhaustive fluid dynamic data to validate CFD techniques employed

  19. Duct wall impedance control as an advanced concept for acoustic impression

    NASA Technical Reports Server (NTRS)

    Dean, P. D.; Tester, B. J.

    1975-01-01

    Models and tests on an acoustic duct liner system which has the property of controlled-variable acoustic impedance are described. This is achieved by a novel concept which uses the effect of steady air flow through a multi-layer, locally reacting, resonant-cavity absorber. The scope of this work was limited to a 'proof of concept.' The test of the concept was implemented by means of a small-scale, square-section flow duct facility designed specifically for acoustic measurements, with one side of the duct acoustically lined. The test liners were designed with the aid of previously established duct acoustic theory and a semi-empirical impedance model of the liner system. Over the limited range tested, the liner behaved primarily as predicted, exhibiting significant changes in resistance and reactance, thus providing the necessary concept validation.

  20. Surgical monotherapy may be a suitable therapeutic strategy for advanced collecting (Bellini) duct carcinoma: A case report and literature review

    PubMed Central

    Zhu, Liang; Wang, Zijian; Pan, Cizhong; Peng, Ran; Wei, Xiong; Zhong, Zhaohui

    2016-01-01

    Collecting duct carcinoma (CDC), which is also known as Bellini duct carcinoma, accounts for less than 1% of all renal cell carcinoma, which has a poor prognosis. Predominantly, clinicians recognize this disease due to past experience and case reports, and a standard treatment is yet to be established. The present case report describes a 57-year-old male patient with CDC who was successfully treated with a left laparoscopic radical nephrectomy without any adjuvant therapy and compares the present patient's clinical presentation with previously reported cases. By analyzing the differences between these cases, the findings of the present case report and literature review suggested that surgery alone remains the only suitable choice for patients with advanced CDC. PMID:27446340

  1. Generation After Next Propulsor Research: Robust Design for Embedded Engine Systems

    NASA Technical Reports Server (NTRS)

    Arend, David J.; Tillman, Gregory; O'Brien, Walter F.

    2012-01-01

    The National Aeronautics and Space Administration, United Technologies Research Center and Virginia Polytechnic and State University have contracted to pursue multi-disciplinary research into boundary layer ingesting (BLI) propulsors for generation after next environmentally responsible subsonic fixed wing aircraft. This Robust Design for Embedded Engine Systems project first conducted a high-level vehicle system study based on a large commercial transport class hybrid wing body aircraft, which determined that a 3 to 5 percent reduction in fuel burn could be achieved over a 7,500 nanometer mission. Both pylon-mounted baseline and BLI propulsion systems were based on a low-pressure-ratio fan (1.35) in an ultra-high-bypass ratio engine (16), consistent with the next generation of advanced commercial turbofans. An optimized, coupled BLI inlet and fan system was subsequently designed to achieve performance targets identified in the system study. The resulting system possesses an inlet with total pressure losses less than 0.5%, and a fan stage with an efficiency debit of less than 1.5 percent relative to the pylon-mounted, clean-inflow baseline. The subject research project has identified tools and methodologies necessary for the design of next-generation, highly-airframe-integrated propulsion systems. These tools will be validated in future large-scale testing of the BLI inlet / fan system in NASA's 8 foot x 6 foot transonic wind tunnel. In addition, fan unsteady response to screen-generated total pressure distortion is being characterized experimentally in a JT15D engine test rig. These data will document engine sensitivities to distortion magnitude and spatial distribution, providing early insight into key physical processes that will control BLI propulsor design.

  2. Investigation of advanced counterrotation blade configuration concepts for high speed turboprop systems. Task 5: Unsteady counterrotation ducted propfan analysis

    NASA Technical Reports Server (NTRS)

    Hall, Edward J.; Delaney, Robert A.

    1993-01-01

    The primary objective of this study was the development of a time-marching three-dimensional Euler/Navier-Stokes aerodynamic analysis to predict steady and unsteady compressible transonic flows about ducted and unducted propfan propulsion systems employing multiple blade rows. The computer codes resulting from this study are referred to as ADPAC-AOAR\\CR (Advanced Ducted Propfan Analysis Codes-Angle of Attack Coupled Row). This document is the final report describing the theoretical basis and analytical results from the ADPAC-AOACR codes developed under task 5 of NASA Contract NAS3-25270, Unsteady Counterrotating Ducted Propfan Analysis. The ADPAC-AOACR Program is based on a flexible multiple blocked grid discretization scheme permitting coupled 2-D/3-D mesh block solutions with application to a wide variety of geometries. For convenience, several standard mesh block structures are described for turbomachinery applications. Aerodynamic calculations are based on a four-stage Runge-Kutta time-marching finite volume solution technique with added numerical dissipation. Steady flow predictions are accelerated by a multigrid procedure. Numerical calculations are compared with experimental data for several test cases to demonstrate the utility of this approach for predicting the aerodynamics of modern turbomachinery configurations employing multiple blade rows.

  3. Field Test of Advanced Duct-Sealing Technologies Within the Weatherization Assistance Program

    SciTech Connect

    Ternes, MP

    2001-12-05

    A field test of an aerosol-spray duct-sealing technology and a conventional, best-practice approach was performed in 80 homes to determine the efficacy and programmatic needs of the duct-sealing technologies as applied in the U.S. Department of Energy Weatherization Assistance Program. The field test was performed in five states: Iowa, Virginia, Washington, West Virginia, and Wyoming. The study found that, compared with the best-practice approach, the aerosol-spray technology is 50% more effective at sealing duct leaks and can potentially reduce labor time and costs for duct sealing by 70%, or almost 4 crew-hours. Further study to encourage and promote use of the aerosol-spray technology within the Weatherization Assistance Program is recommended. A pilot test of full production weatherization programs using the aerosol-spray technology is recommended to develop approaches for integrating this technology with other energy conservation measures and minimizing impacts on weatherization agency logistics. In order to allow or improve adoption of the aerosol spray technology within the Weatherization Assistance Program, issues must be addressed concerning equipment costs, use of the technology under franchise arrangements with Aeroseal, Inc. (the holders of an exclusive license to use this technology), software used to control the equipment, safety, and training. Application testing of the aerosol-spray technology in mobile homes is also recommended.

  4. A Biomimetic Propulsor for Active Noise Control. Part 2: Theory

    NASA Astrophysics Data System (ADS)

    Annaswamy Krol, A., Jr.; Bandyopadhyay, P. R.

    2000-11-01

    The alteration of radiated noise in underwater propulsors using biomimetic active control is considered. Wake momentum filling is carried out by introducing artificial muscles at the trailing edge of a stator blade of an upstream stator propulsor, and articulating them like a fish tail (see companion abstract Part 1). Using a systems framework, we derive a methodology for the articulation of the muscles with active control. The unsteady force produced on the rotor because of velocity perturbations due to actuator displacements, wake deficits caused by stator boundary layers, and blade rotation is modeled. Linear and adaptive nonlinear control strategies are described for articulating the tail using unsteady force measurements. This active control procedure can be viewed as the realization of “virtual” blades with different sweep and noise characteristics and can affect the noise spectrum due to direct radiation significantly. The work provides an understanding of the effect of nonuniform wakes on radiated noise and can lead to a general approach by which wakes can be altered.

  5. Follow-On Technology Requirement Study for Advanced Subsonic Transport

    NASA Technical Reports Server (NTRS)

    Wendus, Bruce E.; Stark, Donald F.; Holler, Richard P.; Funkhouser, Merle E.

    2003-01-01

    A study was conducted to define and assess the critical or enabling technologies required for a year 2005 entry into service (EIS) engine for subsonic commercial aircraft, with NASA Advanced Subsonic Transport goals used as benchmarks. The year 2005 EIS advanced technology engine is an Advanced Ducted Propulsor (ADP) engine. Performance analysis showed that the ADP design offered many advantages compared to a baseline turbofan engine. An airplane/ engine simulation study using a long range quad aircraft quantified the effects of the ADP engine on the economics of typical airline operation. Results of the economic analysis show the ADP propulsion system provides a 6% reduction in direct operating cost plus interest, with half the reduction resulting from reduced fuel consumption. Critical and enabling technologies for the year 2005 EIS ADP were identified and prioritized.

  6. Duct wall impedance control as an advanced concept for acoustic suppression enhancement. [engine noise reduction

    NASA Technical Reports Server (NTRS)

    Dean, P. D.

    1978-01-01

    A systems concept procedure is described for the optimization of acoustic duct liner design for both uniform and multisegment types. The concept was implemented by the use of a double reverberant chamber flow duct facility coupled with sophisticated computer control and acoustic analysis systems. The optimization procedure for liner insertion loss was based on the concept of variable liner impedance produced by bias air flow through a multilayer, resonant cavity liner. A multiple microphone technique for in situ wall impedance measurements was used and successfully adapted to produce automated measurements for all liner configurations tested. The complete validation of the systems concept was prevented by the inability to optimize the insertion loss using bias flow induced wall impedance changes. This inability appeared to be a direct function of the presence of a higher order energy carrying modes which were not influenced significantly by the wall impedance changes.

  7. Bile Flow Phantom Model and Animal Bile Duct Dilation Model for Evaluating Biliary Plastic Stents with Advanced Hydrophilic Coating

    PubMed Central

    Kwon, Chang-Il; Kim, Gwangil; Jeong, Seok; Lee, Won Seop; Lee, Don Haeng; Ko, Kwang Hyun; Hong, Sung Pyo; Hahm, Ki Baik

    2016-01-01

    Background/Aims The efforts to improve biliary plastic stents (PSs) for decreasing biofilm formation and overcome short patency time have been continued. The aim of this study is to evaluate the effect of advanced hydrophilic coating for patency and biodurability of PS. Methods Using an in vitro bile flow phantom model, we compared patency between prototype PS with hydrophilic coating (PS+HC) and prototype PS without hydrophilic coating (PS−HC). We performed an analysis of the degree of luminal narrowing by microscopic examination. Using an in vivo swine bile duct dilation model made by endoscopic papillary closure and stent insertion, we evaluated biodurability of hydrophilic coating. Results In the phantom model, PS+HC showed less biofilm formation and luminal narrowing than PS−HC at 8 weeks (p<0.05). A total of 31 stents were inserted into the dilated bile duct of seven swine models, and 24 stents were successfully retrieved 8 weeks later. There was no statistical difference of stent patency between the polyethylene PS+HC and the polyurethane PS+HC. The biodurability of hydrophilic coating was sustained up to 8 weeks, when assessing the coating layer by scanning electron microscopy examination. Conclusions Advanced hydrophilic coating technology may extend the patency of PS compared to uncoated PS. PMID:27021507

  8. Investigation of advanced counterrotation blade configuration concepts for high speed turboprop systems. Task 2: Unsteady ducted propfan analysis computer program users manual

    NASA Technical Reports Server (NTRS)

    Hall, Edward J.; Delaney, Robert A.; Bettner, James L.

    1991-01-01

    The primary objective of this study was the development of a time-dependent three-dimensional Euler/Navier-Stokes aerodynamic analysis to predict unsteady compressible transonic flows about ducted and unducted propfan propulsion systems at angle of attack. The computer codes resulting from this study are referred to as Advanced Ducted Propfan Analysis Codes (ADPAC). This report is intended to serve as a computer program user's manual for the ADPAC developed under Task 2 of NASA Contract NAS3-25270, Unsteady Ducted Propfan Analysis. Aerodynamic calculations were based on a four-stage Runge-Kutta time-marching finite volume solution technique with added numerical dissipation. A time-accurate implicit residual smoothing operator was utilized for unsteady flow predictions. For unducted propfans, a single H-type grid was used to discretize each blade passage of the complete propeller. For ducted propfans, a coupled system of five grid blocks utilizing an embedded C-grid about the cowl leading edge was used to discretize each blade passage. Grid systems were generated by a combined algebraic/elliptic algorithm developed specifically for ducted propfans. Numerical calculations were compared with experimental data for both ducted and unducted propfan flows. The solution scheme demonstrated efficiency and accuracy comparable with other schemes of this class.

  9. Initial test results of 40,000 horsepower fan drive gear system for advanced ducted propulsion systems

    NASA Astrophysics Data System (ADS)

    McCune, M. E.

    1993-06-01

    Analytical and model testing during the past several years by industry and NASA have shown projections for further improvements in the next generation of turbofan engines: the advanced ducted propulsion (ADP) system. The ADP offers the fundamental propulsive benefit of high bypass ratio resulting in significant reduction in fuel consumption and noise. One of the key enabling technologies for the ADP is the fan drive gear system (FDGS). After describing the FDGS configuration, the specific technical goals for a back-to-back rig test program are identified and results are presented from the 40,000 horsepower FDGS test program, which demonstrated operation with over 41,000 horsepower, efficiency in excess of the 99.3 percent goal, and successful completion of endurance testing.

  10. Trastuzumab in Treating Patients With Locally Advanced or Metastatic Gallbladder Cancer or Bile Duct Cancer That Cannot Be Removed by Surgery

    ClinicalTrials.gov

    2014-05-15

    Adenocarcinoma of the Extrahepatic Bile Duct; Adenocarcinoma of the Gallbladder; Malignant Neoplasm; Recurrent Extrahepatic Bile Duct Cancer; Recurrent Gallbladder Cancer; Unresectable Extrahepatic Bile Duct Cancer; Unresectable Gallbladder Cancer

  11. Maximizing the efficiency of a flexible propulsor using experimental optimization

    NASA Astrophysics Data System (ADS)

    Quinn, Daniel; Lauder, George; Smits, Alexander

    2014-11-01

    Experimental gradient-based optimization is used to maximize the propulsive efficiency of a heaving and pitching flexible panel. Optimum and near-optimum conditions are studied via direct force measurements and Particle Image Velocimetry (PIV). The net thrust and power are found to scale predictably with the frequency and amplitude of the leading edge, but the efficiency shows a complex multimodal response. Optimum pitch and heave motions are found to produce nearly twice the efficiencies of optimum heave-only motions. Efficiency is globally optimized when (1) the Strouhal number is within an optimal range that varies weakly with amplitude and boundary conditions; (2) the panel is actuated at a resonant frequency of the fluid-propulsor system; (3) heave amplitude is tuned such that trailing edge amplitude is maximized while flow along the body remains attached; and (4) the maximum pitch angle and phase lag are chosen so that the effective angle of attack is minimized. This work was supported by the Office of Naval Research under MURI Grant Number N00014-08-1-0642 (Program Director Dr. Bob Brizzolara), and the National Science Foundation under Grant DBI 1062052 (PI Lisa Fauci) and Grant EFRI-0938043 (PI George Lauder).

  12. Lensing duct

    DOEpatents

    Beach, R.J.; Benett, W.J.

    1994-04-26

    A lensing duct to condense (intensify) light using a combination of front surface lensing and reflective waveguiding is described. The duct tapers down from a wide input side to a narrow output side, with the input side being lens-shaped and coated with an antireflective coating for more efficient transmission into the duct. The four side surfaces are uncoated, preventing light from escaping by total internal reflection as it travels along the duct (reflective waveguiding). The duct has various applications for intensifying light, such as in the coupling of diode array pump light to solid state lasing materials, and can be fabricated from inexpensive glass and plastic. 3 figures.

  13. Lensing duct

    DOEpatents

    Beach, Raymond J. , Benett

    1994-01-01

    A lensing duct to condense (intensify) light using a combination of front surface lensing and reflective waveguiding. The duct tapers down from a wide input side to a narrow output side, with the input side being lens-shaped and coated with an antireflective coating for more efficient transmission into the duct. The four side surfaces are uncoated, preventing light from escaping by total internal reflection as it travels along the duct (reflective waveguiding). The duct has various applications for intensifying light, such as in the coupling of diode array pump light to solid state lasing materials, and can be fabricated from inexpensive glass and plastic.

  14. An introduction to the design of marine propulsors

    NASA Technical Reports Server (NTRS)

    Henderson, R. E.

    1974-01-01

    A summary of methods for marine propulsion design is presented. A list of reports dealing with the design of open propellers, ducted propellers or pumpjets, and waterjets is included. The major problems involved in marine propulsion design are discussed.

  15. Particle deposition in ventilation ducts

    SciTech Connect

    Sippola, Mark R.

    2002-09-01

    Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 {micro}m were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on

  16. Locomotion with flexible propulsors: I. Experimental analysis of pectoral fin swimming in sunfish.

    PubMed

    Lauder, George V; Madden, Peter G A; Mittal, Rajat; Dong, Haibo; Bozkurttas, Meliha

    2006-12-01

    A full understanding of the mechanics of locomotion can be achieved by incorporating descriptions of (1) three-dimensional kinematics of propulsor movement, (2) material properties of the propulsor, (3) power input and control and (4) the fluid dynamics effects of propulsor motion into (5) a three-dimensional computational framework that models the complexity of propulsors that deform and change area. In addition, robotic models would allow for further experimental investigation of changes to propulsor design and for testing of hypothesized relationships between movement and force production. Such a comprehensive suite of data is not yet available for any flexible propulsor. In this paper, we summarize our research program with the goal of producing a comprehensive data set for each of the five components noted above through a study of pectoral fin locomotion in one species of fish: the bluegill sunfish Lepomis macrochirus. Many fish use pectoral fins exclusively for locomotion, and pectoral fins in most fish are integral to generating force during maneuvering. Pectoral fins are complex structures composed of jointed bony supports that are under active control via pectoral fin musculature. During propulsion in sunfish, the fin deforms considerably, has two leading edges, and sunfish can rotate the whole fin or just control individual sections to vector thrust. Fin material properties vary along the length of fin rays and among rays. Experimental fluid dynamic analysis of sunfish pectoral fin locomotion reveals that the fin generates thrust throughout the fin beat cycle, and that the upper and lower edges each produce distinct simultaneous leading edge vortices. The following companion paper provides data on the computational approach taken to understand locomotion using flexible pectoral fins. PMID:17671315

  17. 3-D viscous flow CFD analysis of the propeller effect on an advanced ducted propeller subsonic inlet

    NASA Technical Reports Server (NTRS)

    Iek, Chanthy; Boldman, Donald R.; Ibrahim, Mounir

    1993-01-01

    The time-marching Navier-Stokes code PARC3D was used to study the 3D viscous flow associated with an advanced ducted propeller subsonic inlet at take-off operating conditions. At a free stream Mach number of 0.2, experimental data for the inlet-with-propeller test model indicated that the airflow was attached on the cowl windward lip at an angle of attack of 25 deg became unstable at 29 deg, and separated at 30 deg. An experimental study with a similar inlet and without propeller (through-flow) indicated that flow separation occurred at an angle of attack a few degrees below the value observed when the inlet was tested with the propeller, indicating the propeller's favorable effect on inlet performance. In the present numerical study, flow blockage analogous to the propeller was modeled via a PARC3D computational boundary condition (BC), the 'screen BC', based on 1-1/2 dimension actuator disk theory. The application of the screen BC in this numerical study provided results similar to those of past experimental efforts in which either the blockage device or the propeller was used.

  18. Analysis of Dual Rotating Rake Data from the NASA Glenn Advanced Noise Control Fan Duct with Artificial Sources

    NASA Technical Reports Server (NTRS)

    Dahl, Milo D.; Sutliff, Daniel L.

    2014-01-01

    The Rotating Rake mode measurement system was designed to measure acoustic duct modes generated by a fan stage. Initially, the mode amplitudes and phases were quantified from a single rake measurement at one axial location. To directly measure the modes propagating in both directions within a duct, a second rake was mounted to the rotating system with an offset in both the axial and the azimuthal directions. The rotating rake data analysis technique was then extended to include the data measured by the second rake. The analysis resulted in a set of circumferential mode levels at each of the two rake microphone locations. Radial basis functions were then least-squares fit to this data to obtain the radial mode amplitudes for the modes propagating in both directions within the duct. Validation experiments have been conducted using artificial acoustic sources. Results are shown for the measurement of the standing waves in the duct from sound generated by one and two acoustic sources that are separated into the component modes propagating in both directions within the duct. Measured reflection coefficients from the open end of the duct are compared to analytical predictions.

  19. The 3-D viscous flow CFD analysis of the propeller effect on an advanced ducted propeller subsonic inlet

    NASA Technical Reports Server (NTRS)

    Iek, Chanthy; Boldman, Donald R.; Ibrahim, Mounir

    1993-01-01

    A time marching Navier-Stokes code called PARC3D was used to study the 3-D viscous flow associated with an advanced ducted propeller (ADP) subsonic inlet at take-off operating conditions. At a free stream Mach number of 0.2, experimental data for the inlet-with-propeller test model indicated that the airflow was attached on the cowl windward lip at an angle of attack of 25 degrees became unstable at 29 degrees, and separated at 30 degrees. An experimental study with a similar inlet and with no propeller (through-flow) indicated that flow separation occurred at an angle of attack a few degrees below the value observed when the inlet was tested with the propeller. This tends to indicate that the propeller exerts a favorable effect on the inlet performance. During the through-flow experiment a stationary blockage device was used to successfully simulate the propeller effect on the inlet flow field at angles of attack. In the present numerical study, this flow blockage was modeled via a PARC3D computational boundary condition (BC) called the screen BC. The principle formulation of this BC was based on the one-and-half dimension actuator disk theory. This screen BC was applied at the inlet propeller face station of the computational grid. Numerical results were obtained with and without the screen BC. The application of the screen BC in this numerical study provided results which are similar to the results of past experimental efforts in which either the blockage device or the propeller was used.

  20. Fabrication process of a high temperature polymer matrix engine duct

    NASA Technical Reports Server (NTRS)

    Pratt, R. D.; Wilson, A. J.

    1985-01-01

    The process that was used in the molding of an advanced composite outer by-pass duct planned for the F404 engine is discussed. This duct was developed as a potential replacement for the existing titanium duct in order to reduce both the weight and cost of the duct. The composite duct is now going into the manufacturing technology portion of the program. The duct is fabricated using graphite cloth impregnated with the PMR-15 matrix system.

  1. Duct closure

    DOEpatents

    Vowell, Kennison L.

    1987-01-01

    A closure for an inclined duct having an open upper end and defining downwardly extending passageway. The closure includes a cap for sealing engagement with the open upper end of the duct. Associated with the cap are an array of vertically aligned plug members, each of which has a cross-sectional area substantially conforming to the cross-sectional area of the passageway at least adjacent the upper end of the passageway. The plug members are interconnected in a manner to provide for free movement only in the plane in which the duct is inclined. The uppermost plug member is attached to the cap means and the cap means is in turn connected to a hoist means which is located directly over the open end of the duct.

  2. Investigation of advanced counterrotation blade configuration concepts for high speed turboprop systems. Task 5: Unsteady counterrotation ducted propfan analysis. Computer program user's manual

    NASA Technical Reports Server (NTRS)

    Hall, Edward J.; Delaney, Robert A.; Adamczyk, John J.; Miller, Christopher J.; Arnone, Andrea; Swanson, Charles

    1993-01-01

    The primary objective of this study was the development of a time-marching three-dimensional Euler/Navier-Stokes aerodynamic analysis to predict steady and unsteady compressible transonic flows about ducted and unducted propfan propulsion systems employing multiple blade rows. The computer codes resulting from this study are referred to as ADPAC-AOACR (Advanced Ducted Propfan Analysis Codes-Angle of Attack Coupled Row). This report is intended to serve as a computer program user's manual for the ADPAC-AOACR codes developed under Task 5 of NASA Contract NAS3-25270, Unsteady Counterrotating Ducted Propfan Analysis. The ADPAC-AOACR program is based on a flexible multiple blocked grid discretization scheme permitting coupled 2-D/3-D mesh block solutions with application to a wide variety of geometries. For convenience, several standard mesh block structures are described for turbomachinery applications. Aerodynamic calculations are based on a four-stage Runge-Kutta time-marching finite volume solution technique with added numerical dissipation. Steady flow predictions are accelerated by a multigrid procedure. Numerical calculations are compared with experimental data for several test cases to demonstrate the utility of this approach for predicting the aerodynamics of modern turbomachinery configurations employing multiple blade rows.

  3. Thrust performance of unsteady propulsors using a novel measurement system, and corresponding wake patterns

    PubMed Central

    Clark, Richard P.; Smits, Alexander J.

    2009-01-01

    An apparatus is described for the measurement of unsteady thrust and propulsive efficiency produced by biologically inspired oscillating hydrodynamic propulsors. Force measurement is achieved using a strain-gauge-based force transducer, augmented with a lever to amplify or attenuate the applied force and control the measurement sensitivity and natural frequency of vibration. The lever can be used to tune the system to a specific application and it is shown that, using the lever, the stiffness can be made to increase more rapidly than the measurement sensitivity decreases. Efficiency is computed from measurements of the time-averaged power imparted to the fluid. The apparatus is applied to two different propulsors, demonstrating the versatility of the system; wake visualizations are examined, which provide insight into the physical mechanisms of efficient propulsion. PMID:19946574

  4. Investigation of advanced counterrotation blade configuration concepts for high speed turboprop systems, task 1: Ducted propfan analysis

    NASA Technical Reports Server (NTRS)

    Hall, Edward J.; Delaney, Robert A.; Bettner, James L.

    1990-01-01

    The time-dependent three-dimensional Euler equations of gas dynamics were solved numerically to study the steady compressible transonic flow about ducted propfan propulsion systems. Aerodynamic calculations were based on a four-stage Runge-Kutta time-marching finite volume solution technique with added numerical dissipation. An implicit residual smoothing operator was used to aid convergence. Two calculation grids were employed in this study. The first grid utilized an H-type mesh network with a branch cut opening to represent the axisymmetric cowl. The second grid utilized a multiple-block mesh system with a C-type grid about the cowl. The individual blocks were numerically coupled in the Euler solver. Grid systems were generated by a combined algebraic/elliptic algortihm developed specifically for ducted propfans. Numerical calculations were initially performed for unducted propfans to verify the accuracy of the three-dimensional Euler formulation. The Euler analyses were then applied for the calculation of ducted propfan flows, and predicted results were compared with experimental data for two cases. The three-dimensional Euler analyses displayed exceptional accuracy, although certain parameters were observed to be very sensitive to geometric deflections. Both solution schemes were found to be very robust and demonstrated nearly equal efficiency and accuracy, although it was observed that the multi-block C-grid formulation provided somewhat better resolution of the cowl leading edge region.

  5. Comprehensive Report of Fan Performance From Duct Rake Instrumentation on 1.294 Pressure Ratio, 806 ft/sec Tip Speed Turbofan Simulator Models

    NASA Technical Reports Server (NTRS)

    Jeracki, Robert J.

    2006-01-01

    A large scale model representative of an advanced ducted propulsor-type, low-noise, very high bypass ratio turbofan engine was tested for acoustics, aerodynamic performance, and off-design operability in the NASA Glenn 9- by 15-Foot Low-Speed Wind Tunnel. The test was part of NASA s Advanced Subsonic Technology Noise Reduction Program. The low tip speed fan, nacelle, and un-powered core passage were simulated. As might be expected, the effect of stall management casing treatment was a performance penalty. Reducing the recirculating flow at the fan tip reduced the penalty while still providing sufficient stall margin. Two fans were tested with the same aerodynamic design; one with graphite composite material, and the other with solid titanium. There were surprising performance differences between the two fans, though both blades showed some indication of transitional flow near the tips. Though the pressure and temperature ratios were low for this fan design, the techniques used to improve thermocouple measurement accuracy gave repeatable data with adiabatic efficiencies agreeing within 1 percent. The measured fan adiabatic efficiency at simulated takeoff conditions was 93.7 percent and matched the design intent.

  6. Complicated bile duct stones.

    PubMed

    Roy, Ashwin; Martin, Derrick

    2013-01-01

    Common bile duct stones (CBDSs) are solid deposits that can either form within the gallbladder or migrate to the common bile duct (CBD), or form de novo in the biliary tree. In the USA around 15% of the population have gallstones and of these, 3% present with symptoms annually. Because of this, there have been major advancements in the management of gallstones and related conditions. Management is based on the patient's risk profile; young and healthy patients are likely to be recommended for surgery and elderly patients with comorbidities are usually recommended for endoscopic procedures. Imaging of gallstones has advanced in the last 30 years with endoscopic retrograde cholangiopancreatography evolving from a diagnostic to a therapeutic procedure in removing CBDSs. We present a complicated case of a patient with a CBDS and periampullary diverticulum and discuss the techniques used to diagnose and remove the stone from the biliary system. PMID:23946532

  7. Complicated bile duct stones

    PubMed Central

    Roy, Ashwin; Martin, Derrick

    2013-01-01

    Common bile duct stones (CBDSs) are solid deposits that can either form within the gallbladder or migrate to the common bile duct (CBD), or form de novo in the biliary tree. In the USA around 15% of the population have gallstones and of these, 3% present with symptoms annually. Because of this, there have been major advancements in the management of gallstones and related conditions. Management is based on the patient's risk profile; young and healthy patients are likely to be recommended for surgery and elderly patients with comorbidities are usually recommended for endoscopic procedures. Imaging of gallstones has advanced in the last 30 years with endoscopic retrograde cholangiopancreatography evolving from a diagnostic to a therapeutic procedure in removing CBDSs. We present a complicated case of a patient with a CBDS and periampullary diverticulum and discuss the techniques used to diagnose and remove the stone from the biliary system. PMID:23946532

  8. Advanced in-duct sorbent injection for SO{sub 2} control. Topical report No. 2, Subtask 2.2: Design optimization

    SciTech Connect

    Rosenhoover, W.A.; Stouffer, M.R.; Withum, J.A.

    1994-12-01

    The objective of this research project is to develop second-generation duct injection technology as a cost-effective SO{sub 2} control option for the 1990 Clean Air Act Amendments. Research is focused on the Advanced Coolside process, which has shown the potential for achieving the performance targets of 90% SO{sub 2} removal and 60% sorbent utilization. In Subtask 2.2, Design Optimization, process improvement was sought by optimizing sorbent recycle and by optimizing process equipment for reduced cost. The pilot plant recycle testing showed that 90% SO{sub 2} removal could be achieved at sorbent utilizations up to 75%. This testing also showed that the Advanced Coolside process has the potential to achieve very high removal efficiency (90 to greater than 99%). Two alternative contactor designs were developed, tested and optimized through pilot plant testing; the improved designs will reduce process costs significantly, while maintaining operability and performance essential to the process. Also, sorbent recycle handling equipment was optimized to reduce cost.

  9. Computation of flows in a turn-around duct and a turbine cascade using advanced turbulence models

    NASA Technical Reports Server (NTRS)

    Lakshminarayana, B.; Luo, J.

    1993-01-01

    Numerical investigation has been carried out to evaluate the capability of the Algebraic Reynolds Stress Model (ARSM) and the Nonlinear Stress Model (NLSM) to predict strongly curved turbulent flow in a turn-around duct (TAD). The ARSM includes the near-wall damping term of pressure-strain correlation phi(sub ij,w), which enables accurate prediction of individual Reynolds stress components in wall flows. The TAD mean flow quantities are reasonably well predicted by various turbulence models. The ARSM yields better predictions for both the mean flow and the turbulence quantities than the NLSM and the k-epsilon (k = turbulent kinetic energy, epsilon = dissipation rate of k) model. The NLSM also shows slight improvement over the k-epsilon model. However, all the models fail to capture the recovery of the flow from strong curvature effects. The formulation for phi(sub ij,w) appears to be incorrect near the concave surface. The hybrid k-epsilon/ARSM, Chien's k-epsilon model, and Coakley's q-omega (q = the square root of k, omega = epsilon/k) model have also been employed to compute the aerodynamics and heat transfer of a transonic turbine cascade. The surface pressure distributions and the wake profiles are predicted well by all the models. The k-epsilon model and the k-epsilon/ARSM model provide better predictions of heat transfer than the q-omega model. The k-epsilon/ARSM solutions show significant differences in the predicted skin friction coefficients, heat transfer rates and the cascade performance parameters, as compared to the k-epsilon model. The k-epsilon/ARSM model appears to capture, qualitatively, the anisotropy associated with by-pass transition.

  10. Characterization of microstructure and property evolution in advanced cladding and duct: Materials exposed to high dose and elevated temperature

    DOE PAGESBeta

    Allen, Todd R.; Kaoumi, Djamel; Wharry, Janelle P.; Jiao, Zhijie; Topbasi, Cem; Kohnert, Aaron; Barnard, Leland; Certain, Alicia; Field, Kevin G.; Was, Gary S.; et al

    2015-05-20

    Designing materials for performance in high-radiation fields can be accelerated through a carefully chosen combination of advanced multiscale modeling paired with appropriate experimental validation. Here, the studies reported in this work, the combined efforts of six universities working together as the Consortium on Cladding and Structural Materials, use that approach to focus on improving the scientific basis for the response of ferritic–martensitic steels to irradiation. A combination of modern modeling techniques with controlled experimentation has specifically focused on improving the understanding of radiation-induced segregation, precipitate formation and growth under radiation, the stability of oxide nanoclusters, and the development of dislocationmore » networks under radiation. Experimental studies use both model and commercial alloys, irradiated with both ion beams and neutrons. Lastly, transmission electron microscopy and atom probe are combined with both first-principles and rate theory approaches to advance the understanding of ferritic–martensitic steels.« less

  11. Characterization of microstructure and property evolution in advanced cladding and duct: Materials exposed to high dose and elevated temperature

    SciTech Connect

    Allen, Todd R.; Kaoumi, Djamel; Wharry, Janelle P.; Jiao, Zhijie; Topbasi, Cem; Kohnert, Aaron; Barnard, Leland; Certain, Alicia; Field, Kevin G.; Was, Gary S.; Morgan, Dane L.; Motta, Arthur T.; Wirth, Brian D.; Yang, Y.

    2015-05-20

    Designing materials for performance in high-radiation fields can be accelerated through a carefully chosen combination of advanced multiscale modeling paired with appropriate experimental validation. Here, the studies reported in this work, the combined efforts of six universities working together as the Consortium on Cladding and Structural Materials, use that approach to focus on improving the scientific basis for the response of ferritic–martensitic steels to irradiation. A combination of modern modeling techniques with controlled experimentation has specifically focused on improving the understanding of radiation-induced segregation, precipitate formation and growth under radiation, the stability of oxide nanoclusters, and the development of dislocation networks under radiation. Experimental studies use both model and commercial alloys, irradiated with both ion beams and neutrons. Lastly, transmission electron microscopy and atom probe are combined with both first-principles and rate theory approaches to advance the understanding of ferritic–martensitic steels.

  12. Flue gas duct assembly

    SciTech Connect

    Montana, F.J.

    1984-08-28

    A length of longitudinally extending duct assembly for heated corrosive gases includes an outer support duct and a substantially gas-tight liner. The liner is spaced from the outer support duct by a relatively yielding spacer material that accommodates expansion of the liner in directions parallel to the inner surface of the outer support duct and in directions normal to the inner surface of the outer support duct without imposing any substantial resistance to such thermal expansion.

  13. Hydrodynamic analysis, performance assessment, and actuator design of a flexible tail propulsor in an artificial alligator

    NASA Astrophysics Data System (ADS)

    Philen, Michael; Neu, Wayne

    2011-09-01

    The overall objective of this research is to develop analysis tools for determining actuator requirements and assessing viable actuator technology for design of a flexible tail propulsor in an artificial alligator. A simple hydrodynamic model that includes both reactive and resistive forces along the tail is proposed and the calculated mean thrust agrees well with conventional estimates of drag. Using the hydrodynamic model forces as an input, studies are performed for an alligator ranging in size from 1 cm to 2 m at swimming speeds of 0.3-1.8 body lengths per second containing five antagonistic pairs of actuators distributed along the length of the tail. Several smart materials are considered for the actuation system, and preliminary analysis results indicate that the acrylic electroactive polymer and the flexible matrix composite actuators are potential artificial muscle technologies for the system.

  14. Ducted electromagnetic waves in the Martian ionosphere detected by the Mars Advanced Radar for Subsurface and Ionosphere Sounding radar

    NASA Astrophysics Data System (ADS)

    Zhang, Zhenfei; Orosei, Roberto; Huang, Qian; Zhang, Jie

    2016-07-01

    In the data of the Mars Advanced Radar for Subsurface and Ionosphere Sounding on board the European Space Agency (ESA) mission Mars Express (MEX), a distinctive type of signals (called the "epsilon signature"), which is similar to that previously detected during radio sounding of the terrestrial F region ionosphere, is found. The signature is interpreted to originate from multiple reflections of electromagnetic waves propagating along sounder pulse-created, crustal magnetic field-aligned plasma bubbles (waveguides). The signatures have a low (below 0.5%) occurrence rate and apparent cutoff frequencies 3-5 times higher than the theoretical one for an ordinary mode wave. These properties are explained by the influence of the perpendicular ionospheric plasma density gradient and the sounder pulse frequency on the formation of waveguides.

  15. Duct joining system

    DOEpatents

    Proctor, John P.; deKieffer, Robert C.

    2001-01-01

    A duct joining system for providing an air-tight seal and mechanical connection for ducts and fittings is disclosed. The duct joining system includes a flexible gasket affixed to a male end of a duct or fitting. The flexible gasket is affixed at an angle relative to normal of the male end of the duct. The female end of the other duct includes a raised bead in which the flexible gasket is seated when the ducts are properly joined. The angled flexible gasket seated in the raised bead forms an air-tight seal as well as fastens or locks the male end to the female end. Alternatively, when a flexible duct is used, a band clamp with a raised bead is clamped over the female end of the flexible duct and over the male end of a fitting to provide an air tight seal and fastened connection.

  16. Duct Joining System

    DOEpatents

    Proctor, John P.

    2001-02-27

    A duct joining system for providing an air-tight seal and mechanical connection for ducts and fittings is disclosed. The duct joining system includes a flexible gasket affixed to a male end of a duct or fitting. The flexible gasket is affixed at an angle relative to normal of the male end of the duct. The female end of the other duct includes a raised bead in which the flexible gasket is seated when the ducts are properly joined. The angled flexible gasket seated in the raised bead forms an air-tight seal as well as fastens or locks the male end to the female end. Alternatively, when a flexible duct is used, a band clamp with a raised bead is clamped over the female end of the flexible duct and over the male end of a fitting to provide an air tight seal and fastened connection.

  17. Laparoscopic common bile duct exploration.

    PubMed

    Vecchio, Rosario; MacFadyen, Bruce V

    2002-04-01

    In recent years, laparoscopic common bile duct exploration has become the procedure of choice in the management of choledocholithiasis in several laparoscopic centers. The increasing interest for this laparoscopic approach is due to the development of instrumentation and technique, allowing the procedure to be performed safely, and it is also the result of the revised role of endoscopic retrograde cholangiopancreatography, which has been questioned because of its cost, risk of complications and effectiveness. Many surgeons, however, are still not familiar with this technique. In this article we discuss the technique and results of laparoscopic common bile duct exploration. Both the laparoscopic transcystic approach and choledochotomy are discussed, together with the results given in the literature. When one considers the costs, morbidity, mortality and the time required before the patient can return to work, it would appear that laparoscopic cholecystectomy with common bile duct exploration is more favorable than open surgery or laparoscopic cholecystectomy with preoperative or postoperative endoscopic sphincterotomy. However, the technique requires advanced laparoscopic skills, including suturing, knot tying, the use of a choledochoscope, guidewire, dilators and balloon stone extractor. Although laparoscopic common bile duct exploration appears to be the most cost-effective method to treat common bile duct stones, it should be emphasized that this procedure is very challenging, and it should be performed by well-trained laparoscopic surgeons with experience in biliary surgery. PMID:11981684

  18. Microstructure and Property Evolution in Advanced Cladding and Duct Materials Under Long-Term Irradiation at Elevated Temperature: Critical Experiments

    SciTech Connect

    Was, Gary; Jiao, Zhijie; Allen, Todd; Yang, Yong

    2013-12-20

    The in-service degradation of reactor core materials is related to underlying changes in the irradiated microstructure. During reactor operation, structural components and cladding experience displacement of atoms by collisions with neutrons at temperatures at which the radiation-induced defects are mobile, leading to microstructure evolution under irradiation that can degrade material properties. At the doses and temperatures relevant to fast reactor operation, the microstructure evolves by microchemistry changes due to radiation-induced segregation, dislocation loop formation and growth, radiation induced precipitation, destabilization of the existing precipitate structure, as well as the possibility for void formation and growth. These processes do not occur independently; rather, their evolution is highly interlinked. Radiation-induced segregation of Cr and existing chromium carbide coverage in irradiated alloy T91 track each other closely. The radiation-induced precipitation of Ni-Si precipitates and RIS of Ni and Si in alloys T91 and HCM12A are likely related. Neither the evolution of these processes nor their coupling is understood under the conditions required for materials performance in fast reactors (temperature range 300-600°C and doses to 200 dpa and beyond). Further, predictive modeling is not yet possible, as models for microstructure evolution must be developed along with experiments to characterize these key processes and provide tools for extrapolation. To extend the range of operation of nuclear fuel cladding and structural materials in advanced nuclear energy and transmutation systems to that required for the fast reactor, the irradiation-induced evolution of the microstructure, microchemistry, and the associated mechanical properties at relevant temperatures and doses must be understood. This project builds upon joint work at the proposing institutions, under a NERI-C program that is scheduled to end in September, to understand the effects of

  19. Microstructure and Property Evolution in Advanced Cladding and Duct Materials Under Long-Term and Elevated Temperature Irradiation: Modeling and Experimental Investigation

    SciTech Connect

    Wirth, Brian; Morgan, Dane; Kaoumi, Djamel; Motta, Arthur

    2013-12-01

    irradiation. This project will focus on modeling microstructural and microchemical evolution of irradiated alloys by performing detailed modeling of such microstructure evolution processes coupled with well-designed in situ experiments that can provide validation and benchmarking to the computer codes. The broad scientific and technical objectives of this proposal are to evaluate the microstructure and microchemical evolution in advanced ferritic/martensitic and oxide dispersion strengthened (ODS) alloys for cladding and duct reactor materials under long-term and elevated temperature irradiation, leading to improved ability to model structural materials performance and lifetime. Specifically, we propose four research thrusts, namely Thrust 1: Identify the formation mechanism and evolution for dislocation loops with Burgers vector of a<100> and determine whether the defect microstructure (predominately dislocation loop/dislocation density) saturates at high dose. Thrust 2: Identify whether a threshold irradiation temperature or dose exists for the nucleation of growing voids that mark the beginning of irradiation-induced swelling, and begin to probe the limits of thermal stability of the tempered Martensitic structure under irradiation. Thrust 3: Evaluate the stability of nanometer sized Y- Ti-O based oxide dispersion strengthened (ODS) particles at high fluence/temperature. Thrust 4: Evaluate the extent to which precipitates form and/or dissolve as a function of irradiation temperature and dose, and how these changes are driven by radiation induced segregation and microchemical evolutions and determined by the initial microstructure.

  20. Experimental validation of a ducted propeller analysis method

    NASA Astrophysics Data System (ADS)

    Hughes, M. J.; Kinnas, S. A.; Kerwin, J. E.

    1992-06-01

    A ducted propeller model was tested in the MIT water tunnel. A hub apparatus was designed which allowed for the duct and propeller forces to be measured separately. The forces on the duct and propeller were measured over a range of advance coefficients. Velocities were measured upstream and downstream from the duct using a Laser Doppler Velocimetry system. Using these velocities the exprimental values for the spanwise distribution of circulation on the propeller blades were then calculated. The experimental results were compared to the results from a propeller lifting surface/duct and hub surface panel analysis code over the same range of advance coefficients showing very good agreement for the duct and propeller forces and the circulation in the region of attached flow.

  1. Lightweight Valve Closes Duct Quickly

    NASA Technical Reports Server (NTRS)

    Fournier, Walter L.; Burgy, N. Frank

    1991-01-01

    Expanding balloon serves as lightweight emergency valve to close wide duct. Uninflated balloon stored in housing of duct. Pad resting on burst diaphragm protects balloon from hot gases in duct. Once control system triggers valve, balloon inflates rapidly to block duct. Weighs much less than does conventional butterfly, hot-gas, or poppet valve capable of closing duct of equal diameter.

  2. The Potential Benefits of Advanced Casing Treatment for Noise Attenuation in Utra-High Bypass Ratio Turbofan Engines

    NASA Technical Reports Server (NTRS)

    Elliott, David

    2007-01-01

    In order to increase stall margin in a high-bypass ratio turbofan engine, an advanced casing treatment was developed that extracted a small amount of flow from the casing behind the fan and injected it back in front of the fan. Several different configurations of this casing treatment were designed by varying the distance of the extraction and injection points, as well as varying the amount of flow. These casing treatments were tested on a 55.9 cm (22 in.) scale model of the Pratt & Whitney Advanced Ducted Propulsor in the NASA Glenn 9 by 15 Low Speed Wind Tunnel. While all of the casing treatment configurations showed the expected increase in stall margin, a few of the designs showed a potential noise benefit for certain engine speeds. This paper will show the casing treatments and the results of the testing as well as propose further research in this area. With better prediction and design techniques, future casing treatment configurations could be developed that may result in an optimized casing treatment that could conceivably reduce the noise further.

  3. Ducted auroral kilometric radiation

    NASA Technical Reports Server (NTRS)

    Calvert, W.

    1982-01-01

    Certain discrete, intense wave signals attributed to auroral kilometric radiation (AKR) were observed with ISEE-l while it was within the plasmaspheric shadow zone for direct propagation. It is believed that wave ducting by thin depletions of the plasma density aligned with the magnetic field accounts for such signals, and that their discrete nature is caused by the satellite intercepting individual ducts. These ducts, which were also observed as coincident decreases of the upper hybrid resonance frequency, appeared to be twenty-percent depletions roughly one hundred kilometers across. The AKR, which is emitted approximately perpendicular to the magnetic field, apparently entered these ducts equatorward of the source after the waves had been refracted parallel to the duct axis. A diffuse background was also observed which is consistent with the leakage from similar ducts at lower L-values. These observations establish the existence of ducted AKR, its signature on the satellite wave spectrograms, and new evidence for depletion ducts within the plasmasphere.

  4. Loft duct project report

    SciTech Connect

    Reed, J.R.

    1993-06-01

    On October 16, 1992, during a routine examination of the loft of Building 332, the Building Coordinator observed cracks in the welds of the duct work that services the fume hoods for Rooms 1313, 1321, and 1329. Further examination revealed cracks in the weld of the duct work that services the gloveboxes in Rooms 1321 and 1329. Upon discovery of the cracked welds, facility management immediately took the following two actions: Because one crack in the fume hood exhaust extended 70% around the duct circumference, a 1-ton chain fall was used to secure the duct to the roof support structure to prevent the duct from falling if the duct completely fractured. The Facility Manager suspended plutonium handling operations in the gloveboxes and work in the fume hoods in the affected rooms until the situation could be thoroughly investigated. Building 332 is ventilated by drawing conditioned air from the building hallways into the laboratories, hoods, and gloveboxes. This air is filtered through two sets of high-efficiency particulate air (HEPA) filters before being exhausted from the facility. Figure 1 is a schematic of the typical air flow pattern for the facility. All affected duct work is located in the loft of the facility or pressure zone 4. This ducting is fabricated from 12-, 14- and 16-gauge, 304 stainless-steel sheet stock and joined by the Gas Tungsten Arc Welding (GTAW) process.

  5. Subsonic aerodynamic characteristic of semispan commercial transport model with wing-mounted advanced ducted propeller operating in reverse thrust. [conducted in the Langley 14 by 22 foot subsonic wind tunnel

    NASA Technical Reports Server (NTRS)

    Applin, Zachary T.; Jones, Kenneth M.; Gile, Brenda E.; Quinto, P. Frank

    1994-01-01

    A test was conducted in the Langley 14 by 22 Foot Subsonic Tunnel to determine the effect of the reverse-thrust flow field of a wing-mounted advanced ducted propeller on the aerodynamic characteristics of a semispan subsonic high-lift transport model. The advanced ducted propeller (ADP) model was mounted separately in position alongside the wing so that only the aerodynamic interference of the propeller and nacelle affected the aerodynamic performance of the transport model. Mach numbers ranged from 0.14 to 0.26; corresponding Reynolds numbers ranged from 2.2 to 3.9 x 10(exp 6). The reverse-thrust flow field of the ADP shielded a portion of the wing from the free-stream airflow and reduced both lift and drag. The reduction in lift and drag was a function of ADP rotational speed and free-stream velocity. Test results included ground effects data for the transport model and ADP configuration. The ground plane caused a beneficial increase in drag and an undesirable slight increase in lift. The ADP and transport model performance in ground effect was similar to performance trends observed for out of ground effect. The test results form a comprehensive data set that supports the application of the ADP engine and airplane concept on the next generation of advanced subsonic transports. Before this investigation, the engine application was predicted to have detrimental ground effect characteristics. Ground effect test measurements indicated no critical problems and were the first step in proving the viability of this engine and airplane configuration.

  6. Mean velocity and moments of turbulent velocity fluctuations in the wake of a model ship propulsor

    NASA Astrophysics Data System (ADS)

    Pêgo, J. P.; Lienhart, H.; Durst, F.

    2007-08-01

    ; Schneekluth and Bertram in Ship design for efficiency and economy, 1998), the co-rotating propellers model showed a much stronger swirl in the wake of the propulsor. The anisotropy of turbulence was analyzed using the anisotropy tensor introduced by Lumley and Newman (J Fluid Mech 82(1):161-178, 1977). The invariants of the anisotropy tensor of the wake flow were computed and were plotted in the Lumley-Newman-diagram. These measurements revealed that the anisotropy tensor in the wake of ship propellers is located near to the borders of the invariant map, showing a large degree of anisotropy. They will be presented and will be discussed with respect to applications of turbulence models to predict swirling flows.

  7. Salivary duct stones

    MedlinePlus

    ... glands. Salivary duct stones are a type of salivary gland disorder. ... 83. Jackson NM, Mitchell JL, Walvekar RR. Inflammatory disorders of the salivary glands. In: Flint PW, Haughey BH, Lund LJ, et ...

  8. Effect of yttrium additions on the elevated-temperature tensile properties and hardness of an advanced iron-nickel-chromium LMFBR cladding and duct alloy

    SciTech Connect

    Song, M.H.

    1981-10-01

    The effect of the addition of yttrium on the elevated temperature tensile properties and hardness of an Fe-34% Ni-12% Cr candidate LMFBR cladding and duct alloy was investigated. Tensile tests were performed from room temperature to 800/sup 0/C in 100/sup 0/C steps at strain rates of 2.2 x 10/sup -3/ and 2.2 x 10/sup -4/ sec/sup -1/. Hardness tests were performed from room temperature to 850/sup 0/C in 50/sup 0/C steps. The addition of 0.1% yttrium decreased the yield stress and ultimate tensile stress in the test temperature range employed. Hardness also decreased over this test temperature range. In tensile tests, dynamic strain aging behavior occurred both for the undoped and doped alloy in the temperature range from 200 to 600/sup 0/C and 300 to 600/sup 0/C for the lower and higher strain rate, respectively.

  9. Modern management of common bile duct stones.

    PubMed

    Buxbaum, James

    2013-04-01

    It is imperative for gastroenterologists to understand the different formations of bile duct stones and the various medical treatments available. To minimize the complications of endoscopic retrograde cholangiopancreatography (ERCP), it is critical to appropriately assess the risk of bile duct stones before intervention. Biliary endoscopists should be comfortable with the basic techniques of stone removal, including sphincterotomy, mechanical lithotripsy, and stent placement. It is important to be aware of advanced options, including laser and electrohydraulic stone fragmentation, and papillary dilatation for problematic cases. The timing and need for ERCP in those who require a cholecystectomy is also a consideration. PMID:23540960

  10. Buried and Encapsulated Ducts, Jacksonville, Florida (Fact Sheet)

    SciTech Connect

    Not Available

    2013-11-01

    Ductwork installed in unconditioned attics can significantly increase the overall heating and cooling costs of residential buildings. In fact, estimated duct thermal losses for single-family residential buildings with ductwork installed in unconditioned attics range from 10% to 45%. In a study of three single-story houses in Florida, the Building America research team Consortium for Advanced Residential Buildings (CARB) investigated the strategy of using buried and/or encapsulated ducts (BED) to reduce duct thermal losses in existing homes. The BED strategy consists of burying ducts in loose-fill insulation and/or encapsulating them in closed cell polyurethane spray foam (ccSPF) insulation. There are three possible combinations of BED strategies: (1) buried ducts; (2) encapsulated ducts (with ccSPF); and (3) buried and encapsulated ducts. The best solution for each situation depends on the climate, age of the house, and the configuration of the HVAC system and attic. For new construction projects, the team recommends that ducts be both encapsulated and buried as the minimal planning and costs required for this will yield optimal energy savings. The encapsulated/buried duct strategy, which utilizes ccSPF to address condensation concerns, is an approach that was developed specifically for humid climates.

  11. Advanced turboprop testbed systems study

    NASA Technical Reports Server (NTRS)

    Goldsmith, I. M.

    1982-01-01

    The proof of concept, feasibility, and verification of the advanced prop fan and of the integrated advanced prop fan aircraft are established. The use of existing hardware is compatible with having a successfully expedited testbed ready for flight. A prop fan testbed aircraft is definitely feasible and necessary for verification of prop fan/prop fan aircraft integrity. The Allison T701 is most suitable as a propulsor and modification of existing engine and propeller controls are adequate for the testbed. The airframer is considered the logical overall systems integrator of the testbed program.

  12. Patent arterial duct

    PubMed Central

    Forsey, Jonathan T; Elmasry, Ola A; Martin, Robin P

    2009-01-01

    Patent arterial duct (PAD) is a congenital heart abnormality defined as persistent patency in term infants older than three months. Isolated PAD is found in around 1 in 2000 full term infants. A higher prevalence is found in preterm infants, especially those with low birth weight. The female to male ratio is 2:1. Most patients are asymptomatic when the duct is small. With a moderate-to-large duct, a characteristic continuous heart murmur (loudest in the left upper chest or infraclavicular area) is typical. The precordium may be hyperactive and peripheral pulses are bounding with a wide pulse pressure. Tachycardia, exertional dyspnoea, laboured breathing, fatigue or poor growth are common. Large shunts may lead to failure to thrive, recurrent infection of the upper respiratory tract and congestive heart failure. In the majority of cases of PAD there is no identifiable cause. Persistence of the duct is associated with chromosomal aberrations, asphyxia at birth, birth at high altitude and congenital rubella. Occasional cases are associated with specific genetic defects (trisomy 21 and 18, and the Rubinstein-Taybi and CHARGE syndromes). Familial occurrence of PAD is uncommon and the usual mechanism of inheritance is considered to be polygenic with a recurrence risk of 3%. Rare families with isolated PAD have been described in which the mode of inheritance appears to be dominant or recessive. Familial incidence of PAD has also been linked to Char syndrome, familial thoracic aortic aneurysm/dissection associated with patent arterial duct, and familial patent arterial duct and bicuspid aortic valve associated with hand abnormalities. Diagnosis is based on clinical examination and confirmed with transthoracic echocardiography. Assessment of ductal blood flow can be made using colour flow mapping and pulsed wave Doppler. Antenatal diagnosis is not possible, as PAD is a normal structure during antenatal life. Conditions with signs and symptoms of pulmonary overcirculation

  13. Patent arterial duct.

    PubMed

    Forsey, Jonathan T; Elmasry, Ola A; Martin, Robin P

    2009-01-01

    Patent arterial duct (PAD) is a congenital heart abnormality defined as persistent patency in term infants older than three months. Isolated PAD is found in around 1 in 2000 full term infants. A higher prevalence is found in preterm infants, especially those with low birth weight. The female to male ratio is 2:1. Most patients are asymptomatic when the duct is small. With a moderate-to-large duct, a characteristic continuous heart murmur (loudest in the left upper chest or infraclavicular area) is typical. The precordium may be hyperactive and peripheral pulses are bounding with a wide pulse pressure. Tachycardia, exertional dyspnoea, laboured breathing, fatigue or poor growth are common. Large shunts may lead to failure to thrive, recurrent infection of the upper respiratory tract and congestive heart failure. In the majority of cases of PAD there is no identifiable cause. Persistence of the duct is associated with chromosomal aberrations, asphyxia at birth, birth at high altitude and congenital rubella. Occasional cases are associated with specific genetic defects (trisomy 21 and 18, and the Rubinstein-Taybi and CHARGE syndromes). Familial occurrence of PAD is uncommon and the usual mechanism of inheritance is considered to be polygenic with a recurrence risk of 3%. Rare families with isolated PAD have been described in which the mode of inheritance appears to be dominant or recessive. Familial incidence of PAD has also been linked to Char syndrome, familial thoracic aortic aneurysm/dissection associated with patent arterial duct, and familial patent arterial duct and bicuspid aortic valve associated with hand abnormalities. Diagnosis is based on clinical examination and confirmed with transthoracic echocardiography. Assessment of ductal blood flow can be made using colour flow mapping and pulsed wave Doppler. Antenatal diagnosis is not possible, as PAD is a normal structure during antenatal life. Conditions with signs and symptoms of pulmonary overcirculation

  14. Turbofan Duct Propagation Model

    NASA Technical Reports Server (NTRS)

    Lan, Justin H.; Posey, Joe W. (Technical Monitor)

    2001-01-01

    The CDUCT code utilizes a parabolic approximation to the convected Helmholtz equation in order to efficiently model acoustic propagation in acoustically treated, complex shaped ducts. The parabolic approximation solves one-way wave propagation with a marching method which neglects backwards reflected waves. The derivation of the parabolic approximation is presented. Several code validation cases are given. An acoustic lining design process for an example aft fan duct is discussed. It is noted that the method can efficiently model realistic three-dimension effects, acoustic lining, and flow within the computational capabilities of a typical computer workstation.

  15. What Is Bile Duct Cancer?

    MedlinePlus

    ... of bile duct cancer. The rest of this document refers only to cholangiocarcinomas. Benign bile duct tumors ... tumors, which aren’t discussed further in this document. Other cancers in the liver The most common ...

  16. Dynamic instability of ducts conveying fluid

    NASA Technical Reports Server (NTRS)

    Yu, Y. Y.

    1975-01-01

    A finite element analysis was used to study dynamic instability in ducts conveying high speed fluids. Ducts examined include cantilevered curved, flexibly supported, arbitrarily shaped, and composite duct systems. Partial differential equations were used to study the duct systems.

  17. Development of a 32 Inch Diameter Levitated Ducted Fan Conceptual Design

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.; Gallo, Christopher a.; Solano, Paul A.; Thompson, William K.; Vrnak, Daniel R.

    2006-01-01

    The NASA John H. Glenn Research Center has developed a revolutionary 32 in. diameter Levitated Ducted Fan (LDF) conceptual design. The objective of this work is to develop a viable non-contact propulsion system utilizing Halbach arrays for all-electric flight, and many other applications. This concept will help to reduce harmful emissions, reduce the Nation s dependence on fossil fuels, and mitigate many of the concerns and limitations encountered in conventional aircraft propulsors. The physical layout consists of a ducted fan drum rotor with blades attached at the outer diameter and supported by a stress tuner ring at the inner diameter. The rotor is contained within a stator. This concept exploits the unique physical dimensions and large available surface area to optimize a custom, integrated, electromagnetic system that provides both the levitation and propulsion functions. The rotor is driven by modulated electromagnetic fields between the rotor and the stator. When set in motion, the time varying magnetic fields interact with passive coils in the stator assembly to produce repulsive forces between the stator and the rotor providing magnetic suspension. LDF can provide significant improvements in aviation efficiency, reliability, and safety, and has potential application in ultra-efficient motors, computers, and space power systems.

  18. Duct Leakage Repeatability Testing

    SciTech Connect

    Walker, Iain; Sherman, Max

    2014-08-01

    The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques for duct leakage using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards. The three duct leak measurement methods assessed in this report are the two duct pressurization methods that are commonly used by many practitioners and the DeltaQ technique. These are methods B, C and A, respectively of the ASTM E1554 standard. Although it would be useful to evaluate other duct leak test methods, this study focused on those test methods that are commonly used and are required in various test standards, such as BPI (2010), RESNET (2014), ASHRAE 62.2 (2013), California Title 24 (CEC 2012), DOE Weatherization and many other energy efficiency programs.

  19. Cornice Duct System

    SciTech Connect

    Wayne Place; Chuck Ladd

    2004-10-29

    SYNERGETICS, INC., has designed, developed, and tested an air handling duct system that integrates the air duct with the cornice trim of interior spaces. The device has the advantage that the normal thermal losses from ducts into unconditioned attics and crawl spaces can be totally eliminated by bringing the ducts internal to the conditioned space. The following report details work conducted in the second budget period to develop the Cornice Duct System into a viable product for use in a variety of residential or small commercial building settings. A full-scale prototype has been fabricated and tested in a laboratory test building at the Daylighting Facility at North Carolina State University., Based on the results of that testing, the prototype design as been refined, fabricated, installed, and extensively tested in a residential laboratory house. The testing indicates that the device gives substantially superior performance to a standard air distribution system in terms of energy performance and thermal comfort. Patent Number US 6,511,373 B2 has been granted on the version of the device installed and tested in the laboratory house. (A copy of that patent is attached.) Refinements to the device have been carried through two additional design iterations, with a particular focus on reducing installation time and cost and refining the air control system. These new designs have been fabricated and tested and show substantial promise. Based on these design and testing iterations, a final design is proposed as part of this document. That final design is the basis for a continuation in part currently being filed with the U.5, Patent office.

  20. Remnant cystic duct adenocarcinoma presenting as gastric outlet obstruction

    PubMed Central

    Lo, Samuel Tsoon Wuan; Cheng, Yue; Cheung, Frances; Tang, Chung Ngai

    2016-01-01

    Only a few case reports of remnant cystic duct carcinoma exist. The presented case of remnant cystic duct carcinoma with invasion to pylorus and bulbus of duodenum leading to gastric outlet obstruction was the first of its kind. We reviewed all cases of remnant cystic duct carcinoma that we found in the literature and summarized its definition, presentation, extent of invasion and clinical outcome after operation. The diagnosis can be difficult due to the rarity of disease, locally advanced nature of disease and distorted postoperative anatomy. A high index of suspicion can increase the likelihood of a preoperative diagnosis. PMID:27154747

  1. BETTER DUCT SYSTEMS FOR HOME HEATING AND COOLING.

    SciTech Connect

    ANDREWS,J.

    2001-01-01

    This is a series of six guides intended to provide a working knowledge of residential heating and cooling duct systems, an understanding of the major issues concerning efficiency, comfort, health, and safety, and practical tips on installation and repair of duct systems. These guides are intended for use by contractors, system designers, advanced technicians, and other HVAC professionals. The first two guides are also intended to be accessible to the general reader.

  2. Lacrimal duct cyst abscess.

    PubMed

    Dharmasena, Aruna; Sobajo, Cassandra; Irion, Luciane; Ataullah, Sajid

    2014-12-01

    Cystic dilatation within the lacrimal gland is thought to be related to chronic inflammation and scarring of the lacrimal gland ductules. We review the literature and discuss a case and of lacrimal duct cyst suppuration presenting with visual loss, external ophthalmoplegia, proptosis and ptosis. To our knowledge, only one other report of a lacrimal ductal cyst abscess has been reported in the literature so far. PMID:25208223

  3. Generation of Higher Order Modes in a Rectangular Duct

    NASA Technical Reports Server (NTRS)

    Gerhold, Carl H.; Cabell, Randolph H.; Brown, Donald E.

    2004-01-01

    Advanced noise control methodologies to reduce sound emission from aircraft engines take advantage of the modal structure of the noise in the duct. This noise is caused by the interaction of rotor wakes with downstream obstructions such as exit guide vanes. Mode synthesis has been accomplished in circular ducts and current active noise control work has made use of this capability to cancel fan noise. The goal of the current effort is to examine the fundamental process of higher order mode propagation through an acoustically treated, curved duct. The duct cross-section is rectangular to permit greater flexibility in representation of a range of duct curvatures. The work presented is the development of a feedforward control system to generate a user-specified modal pattern in the duct. The multiple-error, filtered-x LMS algorithm is used to determine the magnitude and phase of signal input to the loudspeakers to produce a desired modal pattern at a set of error microphones. Implementation issues, including loudspeaker placement and error microphone placement, are discussed. Preliminary results from a 9-3/8 inch by 21 inch duct, using 12 loudspeakers and 24 microphones, are presented. These results demonstrate the ability of the control system to generate a user-specified mode while suppressing undesired modes.

  4. Measure Guideline: Buried and/or Encapsulated Ducts

    SciTech Connect

    Shapiro, C.; Zoeller, W.; Mantha, P.

    2013-08-01

    Buried and/or encapsulated ducts (BEDs) are a class of advanced, energy-efficiency strategies intended to address the significant ductwork thermal losses associated with ducts installed in unconditioned attics. BEDs are ducts installed in unconditioned attics that are covered in loose-fill insulation and/or encapsulated in closed cell polyurethane spray foam insulation. This Measure Guideline covers the technical aspects of BEDs as well as the advantages, disadvantages, and risks of BEDs compared to other alternative strategies. This guideline also provides detailed guidance on installation of BEDs strategies in new and existing homes through step-by-step installation procedures. Some of the procedures presented here, however, require specialized equipment or expertise. In addition, some alterations to duct systems may require a specialized license.

  5. Technology Solutions Case Study: Buried and Encapsulated Ducts, Jacksonville, Florida

    SciTech Connect

    2013-11-01

    Ductwork installed in unconditioned attics can significantly increase the overall heating and cooling costs of residential buildings. In fact, estimated duct thermal losses for single-family residential buildings with ductwork installed in unconditioned attics range from 10% to 45%. In a study of three single-story houses in Florida, the Building America research team Consortium for Advanced Residential Buildings (CARB) investigated the strategy of using buried and/or encapsulated ducts (BED) to reduce duct thermal losses in existing homes. The BED strategy consists of burying ducts in loose-fill insulation and/or encapsulating them in closed cell polyurethane spray foam (ccSPF) insulation; specifically for use in humid climates.

  6. Bile duct malignancies.

    PubMed

    Tucek, S; Tomasek, J; Halámkova, J; Kiss, I; Andrasina, T; Hemmelová, B; Adámková-Krákorová, D; Vyzula, R

    2010-01-01

    Bile duct malignancies include intrahepatic cholangiocarcinoma (ICC), extrahepatic cholangiocarcinoma (ECC), gall bladder carcinoma (GC) and carcinoma of Vater's ampulla (ampulloma). Bile duct neoplasms are rare tumours with overall poor prognosis. The overall incidence affects up to 12.5 per 100,000 persons in the Czech Republic. The mortality rate has risen recently to 9.5 per 100,000 persons. The incidence and mortality have been remarkably stable over the past 3 decades. The survival rate of patients with these tumours is poor, usually not exceeding 12 months. The diagnostic process is complex, uneasy and usually late. Most cases are diagnosed when unresectable, and palliative treatment is the main approach of medical care for these tumours. The treatment remains very challenging. New approaches have not brought much improvement in this field. Standards of palliative care are lacking and quality of life assessments are surprisingly not common. From the scarce data it seems, however, that multimodal individually tailored treatment can prolong patients'survival and improve the health-related quality of life. The care in specialized centres offers methods of surgery, interventional radiology, clinical oncology and high quality supportive care. These methods are discussed in the article in greater detail. Improvements in this field can be sought in new diagnostic methods and new procedures in surgery and interventional radiology. Understanding the tumour biology on the molecular level could shift the strategy to a more successful one, resulting in more cured patients. Further improvements in palliative care can be sought by defining new targets and new drug development. The lack of patients with bile duct neoplasms has been the limiting factor for any improvements. A new design of larger randomized international multicentric clinical trials with prompt data sharing could help to overcome this major problem. Defining standards of palliative care is a necessity

  7. Intrahepatic Transposition of Bile Ducts

    PubMed Central

    Delić, Jasmin; Savković, Admedina; Isaković, Eldar; Marković, Sergije; Bajtarevic, Alma; Denjalić, Amir

    2012-01-01

    Objective. To describe the intrahepatic bile duct transposition (anatomical variation occurring in intrahepatic ducts) and to determine the frequency of this variation. Material and Methods. The researches were performed randomly on 100 livers of adults, both sexes. Main research methods were anatomical macrodissection. As a criterion for determination of variations in some parts of bile tree, we used the classification of Segmentatio hepatis according to Couinaud (1957) according to Terminologia Anatomica, Thieme Stuugart: Federative Committee on Anatomical Terminology, 1988. Results. Intrahepatic transposition of bile ducts was found in two cases (2%), out of total examined cases (100): right-left transposition (right segmental bile duct, originating from the segment VIII, joins the left liver duct-ductus hepaticus sinister) and left-right intrahepatic transposition (left segmental bile duct originating from the segment IV ends in right liver duct-ductus hepaticus dexter). Conclusion. Safety and success in liver transplantation to great extent depends on knowledge of anatomy and some common embryological anomalies in bile tree. Variations in bile tree were found in 24–43% of cases, out of which 1–22% are the variations of intrahepatic bile ducts. Therefore, good knowledge on ductal anatomy enables good planning, safe performance of therapeutic and operative procedures, and decreases the risk of intraoperative and postoperative complications. PMID:22550601

  8. Ascariasis of the pancreatic duct.

    PubMed

    Klimovskij, Michail; Dulskas, Audrius; Kraulyte, Zita; Mikalauskas, Saulius

    2015-01-01

    Ascariasis is a common helminthic disease worldwide, although Lithuania and other European countries are not considered endemic areas. The presence of the Ascaris worm in the biliary tree causes choledocholithiasis-like symptoms. We report a case of pancreatic duct ascariasis causing such symptoms. A 73-year-old Lithuanian woman underwent endoscopic retrograde cholangiopancreatography (ERCP) suspecting choledocholithiasis. Contrast injection into the common bile duct demonstrated a slightly dilated biliary tree without any filling defects, and the tail of an Ascaris worm protruding from the opening of the papilla Vater. The worm was captured by a snare but escaped deep into the duct. After a small wirsungotomy the worm was retrieved from the pancreatic duct. The patient received a 150 mg dose of levamisole orally repeated 7 days later and was discharged after complete resolution of symptoms. This first reported sporadic case of pancreatic duct ascariasis in Lithuania was successfully treated with ERCP and Levamisole. PMID:26374772

  9. The impact of duct-to-duct interaction on the hex duct dilation

    SciTech Connect

    Lee, M.J.; Chang, L.K.; Lahm, C.E.; Porter, D.L.

    1992-07-01

    Dilation of the hex duct is an important factor in the operational lifetime of fuel subassemblies in liquid metal fast reactors. It is caused primarily by the irradiation-enhanced creep and void swelling of the hex duct material. Excessive dilation may jeopardize subassembly removal from the core or cause a subassembly storage problem where the grid size of the storage basket is limited. Dilation of the hex duct in Experimental Breeder Reactor II (EBR-II) limits useful lifetime because of these storage basket limitations. It is, therefore, important to understand the hex duct dilation behavior to guide the design and in-core management of fuel subassemblies in a way that excessive duct deformation can be avoided. To investigate the dilation phenomena, finite-element models of the hex duct have been developed. The inelastic analyses were performed using the structural analysis code, ANSYS. Both Type 316 and D9 austenitic stainless steel ducts are considered. The calculated dilations are in good agreement with profilometry measurements made after irradiation. The analysis indicates that subassembly interaction is an important parameter in addition to neutron fluence and temperature in determining hex duct dilation. 5 refs.

  10. Measure Guideline: Buried and/or Encapsulated Ducts

    SciTech Connect

    Shapiro, C.; Zoeller, W.; Mantha, P.

    2013-08-01

    Buried and/or encapsulated ducts (BEDs) are a class of advanced, energy-efficiency strategies intended to address the significant ductwork thermal losses associated with ducts installed in unconditioned attics. BEDs are ducts installed in unconditioned attics that are covered in loose-fill insulation and/or encapsulated in closed cell polyurethane spray foam insulation. This Measure Guideline covers the technical aspects of BEDs as well as the advantages, disadvantages, and risks of BEDs compared to other alternative strategies. This guideline also provides detailed guidance on installation of BEDs strategies in new and existing homes through step-by-step installation procedures. This Building America Measure Guideline synthesizes previously published research on BEDs and provides practical information to builders, contractors, homeowners, policy analysts, building professions, and building scientists. Some of the procedures presented here, however, require specialized equipment or expertise. In addition, some alterations to duct systems may require a specialized license. Persons implementing duct system improvements should not go beyond their expertise or qualifications. This guideline provides valuable information for a building industry that has struggled to address ductwork thermal losses in new and existing homes. As building codes strengthen requirements for duct air sealing and insulation, flexibility is needed to address energy efficiency goals. While ductwork in conditioned spaces has been promoted as the panacea for addressing ductwork thermal losses, BEDs installations approach - and sometimes exceed - the performance of ductwork in conditioned spaces.

  11. PMR Graphite Engine Duct Development

    NASA Technical Reports Server (NTRS)

    Stotler, C. L.; Yokel, S. A.

    1989-01-01

    The objective was to demonstrate the cost and weight advantages that could be obtained by utilizing the graphite/PMR15 material system to replace titanium in selected turbofan engine applications. The first component to be selected as a basis for evaluation was the outer bypass duct of the General Electric F404 engine. The operating environment of this duct was defined and then an extensive mechanical and physical property test program was conducted using material made by processing techniques which were also established by this program. Based on these properties, design concepts to fabricate a composite version of the duct were established and two complete ducts fabricated. One of these ducts was proof pressure tested and then run successfully on a factory test engine for over 1900 hours. The second duct was static tested to 210 percent design limit load without failure. An improved design was then developed which utilized integral composite end flanges. A complete duct was fabricated and successfully proof pressure tested. The net results of this effort showed that a composite version of the outer duct would be 14 percent lighter and 30 percent less expensive that the titanium duct. The other type of structure chosen for investigation was the F404 fan stator assembly, including the fan stator vanes. It was concluded that it was feasible to utilize composite materials for this type structure but that the requirements imposed by replacing an existing metal design resulted in an inefficient composite design. It was concluded that if composites were to be effectively used in this type structure, the design must be tailored for composite application from the outset.

  12. 14 CFR 29.1103 - Induction systems ducts and air duct systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Induction systems ducts and air duct... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Induction System § 29.1103 Induction systems ducts and air duct systems. (a) Each induction system duct upstream of the...

  13. Articulated transition duct in turbomachine

    DOEpatents

    Flanagan, James Scott; McMahan, Kevin Weston; LeBegue, Jeffrey Scott; Pentecost, Ronnie Ray

    2014-04-29

    Turbine systems are provided. A turbine system includes a transition duct comprising an inlet, an outlet, and a duct passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The duct passage includes an upstream portion and a downstream portion. The upstream portion extends from the inlet between an inlet end and an aft end. The downstream portion extends from the outlet between an outlet end and a head end. The turbine system further includes a joint coupling the aft end of the upstream portion and the head end of the downstream portion together. The joint is configured to allow movement of the upstream portion and the downstream portion relative to each other about or along at least one axis.

  14. Wave reflections from duct terminations.

    PubMed

    Selamet, A; Ji, Z L; Kach, R A

    2001-04-01

    The reflection coefficients and inertial end corrections of several duct terminations, including finite length duct extensions perpendicular to an infinite wall, as well as at a number of angles, curved interface surfaces, and annular cavities, are determined and analyzed in the absence of flow by employing the boundary element method. Predictions for the classical unflanged and flanged circular ducts show good agreement with analytical and computational results available in the literature. The predictions for curved interface surfaces (bellmouth or horn) are also consistent with the available experimental data. In view of its high reflection coefficient, the duct termination with an annular cavity may be suggested for the suppression of noise radiation in a specific frequency band or for an effective wave reflection from the termination. PMID:11325101

  15. Sound propagation in choked ducts

    NASA Technical Reports Server (NTRS)

    Hersh, A. S.; Liu, C. Y.

    1976-01-01

    The linearized equations describing the propagation of sound in variable area ducts containing flow are shown to be singular when the duct mean flow is sonic. The singularity is removed when previously ignored nonlinear terms are retained. The results of a numerical study, for the case of plane waves propagating in a one-dimensional converging-diverging duct, show that the sound field is adequately described by the linearized equations only when the axial mean flow Mach number at the duct throat M sub th 0.6. For M sub th 0.6, the numerical results showed that acoustic energy flux was not conserved. An attempt was made to extend the study to include the nonlinear behavior of the sound field. Meaningful results were not obtained due, primarily, to numerical difficulties.

  16. Flow duct for nuclear reactors

    DOEpatents

    Straalsund, Jerry L.

    1978-01-01

    Improved liquid sodium flow ducts for nuclear reactors are described wherein the improvement comprises varying the wall thickness of each of the walls of a polygonal tubular duct structure so that each of the walls is of reduced cross-section along the longitudinal center line and of a greater cross-section along wall junctions with the other walls to form the polygonal tubular configuration.

  17. TWO NEW DUCT LEAKAGE TESTS

    SciTech Connect

    ANDREWS,J.W.

    1998-12-01

    Two variations on the tests for duct leakage currently embodied in ASHRAE Standard 152P (Method of Test for Determining the Design and Seasonal Efficiencies of Residential Thermal Distribution Systems) are presented. Procedures are derived for calculating supply and return duct leakage to/from outside using these new variations. Results of these tests are compared with the original ones in Standard 152P on the basis of data collected in three New York State homes.

  18. Two New Duct Leakage Tests

    SciTech Connect

    Andrews, J.W.

    1998-12-01

    Two variations on the tests for duct leakage currently embodied in ASHRAE Standard 152P (Method of Test for Determining the Design and Seasonal Efficiencies of Residential Thermal Distribution Systems) are presented. Procedures are derived for calculating supply and return duct leakage to/from outside using these new variations. Results of these tests are compared with the original ones in Standard 152P on the basis of data collected in three New York State homes.

  19. Duct Leakage Repeatability Testing

    SciTech Connect

    Walker, Iain; Sherman, Max

    2014-01-01

    Duct leakage often needs to be measured to demonstrate compliance with requirements or to determine energy or Indoor Air Quality (IAQ) impacts. Testing is often done using standards such as ASTM E1554 (ASTM 2013) or California Title 24 (California Energy Commission 2013 & 2013b), but there are several choices of methods available within the accepted standards. Determining which method to use or not use requires an evaluation of those methods in the context of the particular needs. Three factors that are important considerations are the cost of the measurement, the accuracy of the measurement and the repeatability of the measurement. The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards.

  20. Turbofan aft duct suppressor study

    NASA Technical Reports Server (NTRS)

    Syed, A. A.; Motsinger, R. E.; Fiske, G. H.; Joshi, M. C.; Kraft, R. E.

    1983-01-01

    Suppressions due to acoustic treatment in the annular exhaust duct of a model fan were theoretically predicted and compared with measured suppressions. The predictions are based on the modal analysis of sound propagation in a straight annular flow duct with segmented treatment. Modal distributions of the fan noise source (fan-stator interaction only) were measured using in-duct modal probes. The flow profiles were also measured in the vicinity of the modal probes. The acoustic impedance of the single degree of freedom treatment was measured in the presence of grazing flow. The measured values of mode distribution of the fan noise source, the flow velocity profile and the acoustic impedance of the treatment in the duct were used as input to the prediction program. The predicted suppressions, under the assumption of uniform flow in the duct, compared well with the suppressions measured in the duct for all test conditions. The interaction modes generated by the rotor-stator interaction spanned a cut-off ratio range from nearly 1 to 7.

  1. Bile duct invasion can be an independent prognostic factor in early stage hepatocellular carcinoma

    PubMed Central

    Jang, Ye-Rang; Kim, Hyeyoung; Lee, Jeong-Moo; Yi, Nam-Joon; Suh, Kyung-Suk

    2015-01-01

    Backgrounds/Aims In hepatocellular carcinoma (HCC), bile duct invasion occurs far more rarely than vascular invasion and is not well characterized. In addition, the pathologic finding of bile duct invasion is not considered an independent prognostic factor for HCC following surgery. In this study, we determined the characteristics of HCC with bile duct invasion, and assessed the clinical significance of bile duct invasion. Methods We retrospectively reviewed the medical records of 363 patients who underwent hepatic resection for HCC at Seoul National University Hospital (SNUH) from January 2009 to December 2011. Preoperative, operative, and pathological data were collected. The risk factors for recurrence and survival were analyzed. Subsequently, the patients were divided into 2 groups according to disease stage (American Joint Committee on Cancer/International Union Against Cancer 7th edition): early stage (T1 and 2) and advanced stage (T3 and 4) group; and risk factors in the sub-groups were analyzed. Results Among 363 patients, 13 showed bile duct invasion on pathology. Patients with bile duct invasion had higher preoperative total bilirubin levels, greater microvascular invasion, and a higher death rate than those without bile duct invasion. In multivariate analysis, bile duct invasion was not an independent prognostic factor for survival for the entire cohort, but, was an independent prognostic factor for early stage. Conclusions Bile duct invasion accompanied microvascular invasion in most cases, and could be used as an independent prognostic factor for survival especially in early stage HCC (T1 and T2). PMID:26693236

  2. Evaporation duct communication: Test Plan

    NASA Astrophysics Data System (ADS)

    Anderson, K. D.

    1991-02-01

    The Evaporation Duct Communication (EDCOM) project is an effort to provide an alternative ship-to-ship communications channel using the natural environment. A microwave communication link can be used on an over-the-water, over-the-horizon path through the evaporation duct. This report shows how a microwave communication link, operating at a range separation of more than twice the line-of-sight range, can be constructed. This link can achieve about 80-percent availability at a transmission frequency of 14.5 GHz and can be constructed using off-the-shelf RF equipment. Operation of this link will provide the first set of measurements of channel capacity that can be critically dependent on the existence of an oceanic evaporation duct. Construction of this link presents a unique opportunity to study and evaluate an alternative communications channel that can be used to alleviate naval battlegroup communications load.

  3. Congenital Atresia of Wharton's Duct.

    PubMed

    Hseu, Anne; Anne, Premchand; Anne, Samantha

    2016-02-01

    This is a case report of a three-month-old male who presented to clinic with a cystic lesion under the tongue. On clinical examination, a cystic lesion was observed in the, floor-of-mouth. The patient was referred to Paediatric Otorhinolaryngology service for further management. The differential diagnoses for floor-of-mouth lesions should be reviewed with primary focus on the Wharton's duct atresia and its management. It is crucial to recognize submandibular duct atresia in the primary Paediatric clinic in order to expedite management of lesion before complications arise including infection, enlargement of cyst, and feeding and breathing difficulties. PMID:27042492

  4. General Information about Extrahepatic Bile Duct Cancer

    MedlinePlus

    ... Bile Duct Cancer Treatment (PDQ®)–Patient Version General Information About Bile Duct Cancer Go to Health Professional ... the PDQ Adult Treatment Editorial Board . Clinical Trial Information A clinical trial is a study to answer ...

  5. What Are the Key Statistics about Bile Duct Cancer?

    MedlinePlus

    ... for bile duct cancer? What are the key statistics about bile duct cancer? Bile duct cancer is ... it is when it is found. For survival statistics, see the section “ Survival statistics for bile duct ...

  6. Wind Turbine With Concentric Ducts

    NASA Technical Reports Server (NTRS)

    Muhonen, A. J.

    1983-01-01

    Wind Turbine device is relatively compact and efficient. Converging inner and outer ducts increase pressure difference across blades of wind turbine. Turbine shaft drives alternator housed inside exit cone. Suitable for installation on such existing structures as water towers, barns, houses, and commercial buildings.

  7. Vitellointestinal Duct Anomalies in Infancy

    PubMed Central

    Kadian, Yogender Singh; Verma, Anjali; Rattan, Kamal Nain; Kajal, Pardeep

    2016-01-01

    Background: Vitellointestinal duct (VID) or omphalomesenteric duct anomalies are secondary to the persistence of the embryonic vitelline duct, which normally obliterates by weeks 5–9 of intrauterine life. Methods: This is a retrospective analysis of a total of 16 patients of symptomatic remnants of vitellointestinal duct from period of Jan 2009 to May 2013. Results: Male to female ratio (M:F) was 4.3:1 and mean age of presentation was 2 months and their mode of presentation was: patent VID in 9 (56.25%) patients, umbilical cyst in 2(12.25%), umbilical granuloma in 2 (12.25%), and Meckel diverticulum as content of hernia sac in obstructed umbilical hernia in 1 (6.25%) patient. Two patients with umbilical fistula had severe electrolyte disturbance and died without surgical intervention. Conclusion: Persistent VID may have varied presentations in infancy. High output umbilical fistula and excessive bowel prolapse demand urgent surgical intervention to avoid morbidity and mortality. PMID:27433448

  8. Design and performance of duct acoustic treatment

    NASA Technical Reports Server (NTRS)

    Motsinger, R. E.; Kraft, R. E.

    1991-01-01

    The procedure for designing acoustic treatment panels used to line the walls of aircraft engine ducts and for estimating the resulting suppression of turbofan engine duct noise is discussed. This procedure is intended to be used for estimating noise suppression of existing designs or for designing new acoustic treatment panels and duct configurations to achieve desired suppression levels.

  9. 46 CFR 116.610 - Ventilation ducts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... requirements relative to the passage of smoke and flame as the fire control boundary penetrated; (2) A steel duct penetrating an A-Class fire control boundary must be of at least 11 USSG, and a steel duct... duct penetrating an A-Class fire control boundary and opening into a space formed by that boundary...

  10. 46 CFR 116.610 - Ventilation ducts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... requirements relative to the passage of smoke and flame as the fire control boundary penetrated; (2) A steel duct penetrating an A-Class fire control boundary must be of at least 11 USSG, and a steel duct... duct penetrating an A-Class fire control boundary and opening into a space formed by that boundary...

  11. Extrahepatic Bile Duct Obstruction and Erosive Disruption by Cavitating Porta Hepatis Nodal Metastasis, Treated by Uncovered Wallstent

    SciTech Connect

    Trambert, Jonathan J. Frost, Andrei; Malasky, Charlotte

    2004-08-15

    A 45-year-old woman with advanced gastric carcinoma presented with obstructive jaundice. Percutaneous transhepatic cholangiography (PTC) revealed erosive disruption of the extrahepatic bile ducts by a cavitating metastasis in the porta hepatis, as well as a biliary-duodenal fistula. External-internal biliary drainage via the fistula was plagued by recurrent drain occlusion by necrotic debris. This was ultimately alleviated by successful catheterization of the distal common bile duct (CBD) through the cavity, and linking the common hepatic duct (CHD) and CBD with a Wallstent, across the cavity. This succeeded in improving internal biliary drainage and isolating the exfoliating debris of the cavity from the bile ducts.

  12. Analytical screening of low emissions, high performance duct burners for supersonic cruise aircraft engines

    NASA Technical Reports Server (NTRS)

    Lohmann, R. A.; Riecke, G. T.

    1977-01-01

    An analytical screening study was conducted to identify duct burner concepts capable of providing low emissions and high performance in advanced supersonic engines. Duct burner configurations ranging from current augmenter technology to advanced concepts such as premix-prevaporized burners were defined. Aerothermal and mechanical design studies provided the basis for screening these configurations using the criteria of emissions, performance, engine compatibility, cost, weight and relative risk. Technology levels derived from recently defined experimental low emissions main burners are required to achieve both low emissions and high performance goals. A configuration based on the Vorbix (Vortex burning and mixing) combustor concept was analytically determined to meet the performance goals and is consistent with the fan duct envelope of a variable cycle engine. The duct burner configuration has a moderate risk level compatible with the schedule of anticipated experimental programs.

  13. Designing insulation for cryogenic ducts

    NASA Astrophysics Data System (ADS)

    Love, C. C.

    1984-03-01

    It is pointed out that the great temperature difference between the outside of a cryogenic duct and the liquified gas it carries can cause a high heat input unless blocked by a high thermal resistance. High thermal resistance for lines needing maximum insulation is provided by metal vacuum jackets. Low-density foam is satisfactory in cases in which higher heat input can be tolerated. Attention is given to the heat transfer through a duct vacuum jacket, the calculation of heat input and the exterior surface's steady-state temperature for various thicknesses of insulation, the calculation of the heat transfer through gimbal jackets, and design specifications regarding the allowable pressure rise in the jacket's annular space.

  14. Tear-ducts in wine

    NASA Astrophysics Data System (ADS)

    Bush, John W. M.

    1999-11-01

    We examine the radial spoke pattern evident in the meniscus region in glasses of strong alcoholic beverages exhibiting the `tears-in-wine' phenomenon. We demonstrate that the pattern results from ridge-like elevations of the free surface which are supported by evaporatively-driven Marangoni convection in the meniscus region. Vortices associated with the convective motions are aligned in the radial direction by the surface tension gradient responsible for the generation of tears. The radial flow is focussed into the ridges, which thus serve as the principal conduits of fluid for the tears; consequently, we refer to the ridges as `tear-ducts'. The phenomenon is examined experimentally, and a numerical model of evaporatively-driven Marangoni convection is developed which reproduces the salient features of the tear-duct phenomenon.

  15. HAARP-Induced Ionospheric Ducts

    SciTech Connect

    Milikh, Gennady; Vartanyan, Aram

    2011-01-04

    It is well known that strong electron heating by a powerful HF-facility can lead to the formation of electron and ion density perturbations that stretch along the magnetic field line. Those density perturbations can serve as ducts for ELF waves, both of natural and artificial origin. This paper presents observations of the plasma density perturbations caused by the HF-heating of the ionosphere by the HAARP facility. The low orbit satellite DEMETER was used as a diagnostic tool to measure the electron and ion temperature and density along the satellite orbit overflying close to the magnetic zenith of the HF-heater. Those observations will be then checked against the theoretical model of duct formation due to HF-heating of the ionosphere. The model is based on the modified SAMI2 code, and is validated by comparison with well documented experiments.

  16. Small duct primary sclerosing cholangitis without inflammatory bowel disease is genetically different from large duct disease

    PubMed Central

    Næss, Sigrid; Björnsson, Einar; Anmarkrud, Jarl A.; Al Mamari, Said; Juran, Brian D.; Lazaridis, Konstantinos N.; Chapman, Roger; Bergquist, Annika; Melum, Espen; Marsh, Steven G. E.; Schrumpf, Erik; Lie, Benedicte A.; Boberg, Kirsten Muri; Karlsen, Tom H.; Hov, Johannes R.

    2014-01-01

    Background & aims Small duct primary sclerosing cholangitis (PSC) is phenotypically a mild version of large duct PSC, but it is unknown whether these phenotypes share aetiology. We aimed to characterize their relationship by investigating genetic associations in the HLA complex, which represent the strongest genetic risk factors in large duct PSC. Methods Four classical HLA loci (HLA-A, HLA-B, HLA-C, HLA-DRB1) were genotyped in 87 small duct PSC patients, 485 large duct PSC patients and 1117 controls across three geographical regions. Results HLA-DRB1*13:01 (OR=2.0, 95% CI 1.2–3.4, P=0.01) and HLA-B*08 (OR=1.6, 95% CI 1.1–2.4, P=0.02) were significantly associated with small duct PSC compared with healthy controls. Based on the observed frequency of HLA-B*08 in small duct PSC, the strongest risk factor in large duct PSC, an estimated 32% (95% CI 4%–65%) of this population can be hypothesized to represent early stages or mild variants of large duct PSC. This subgroup may be constituted by small duct PSC patients with inflammatory bowel disease (IBD), which greatly resembled large duct PSC in its HLA association. In contrast, small duct PSC without IBD was only associated with HLA-DRB1*13:01(P=0.03) and was otherwise distinctly dissimilar from large duct PSC. Conclusions Small duct PSC with IBD resembles large duct PSC in its HLA association and may represent early stages or mild variants of large duct disease. Different HLA associations in small duct PSC without IBD could indicate that this subgroup is a different entity. HLA-DRB1*13:01 may represent a specific risk factor for inflammatory bile duct disease. PMID:24517468

  17. Modeling particle loss in ventilation ducts

    SciTech Connect

    Sippola, Mark R.; Nazaroff, William W.

    2003-04-01

    Empirical equations were developed and applied to predict losses of 0.01-100 {micro}m airborne particles making a single pass through 120 different ventilation duct runs typical of those found in mid-sized office buildings. For all duct runs, losses were negligible for submicron particles and nearly complete for particles larger than 50 {micro}m. The 50th percentile cut-point diameters were 15 {micro}m in supply runs and 25 {micro}m in return runs. Losses in supply duct runs were higher than in return duct runs, mostly because internal insulation was present in portions of supply duct runs, but absent from return duct runs. Single-pass equations for particle loss in duct runs were combined with models for predicting ventilation system filtration efficiency and particle deposition to indoor surfaces to evaluate the fates of particles of indoor and outdoor origin in an archetypal mechanically ventilated building. Results suggest that duct losses are a minor influence for determining indoor concentrations for most particle sizes. Losses in ducts were of a comparable magnitude to indoor surface losses for most particle sizes. For outdoor air drawn into an unfiltered ventilation system, most particles smaller than 1 {micro}m are exhausted from the building. Large particles deposit within the building, mostly in supply ducts or on indoor surfaces. When filters are present, most particles are either filtered or exhausted. The fates of particles generated indoors follow similar trends as outdoor particles drawn into the building.

  18. Ramjet bypass duct and preburner configuration

    NASA Technical Reports Server (NTRS)

    Orlando, Robert J. (Inventor)

    1994-01-01

    A combined turbofan and ramjet aircraft engine includes a forward bypass duct which allows the engine to operate more efficiently during the turbofan mode of operation. By mounting a ramjet preburner in the forward duct and isolating this duct from the turbofan bypass air, a transition from turbofan operation to ramjet operation can take place at lower flight Mach numbers without incurring pressure losses or blockage in the turbofan bypass air.

  19. Parotid salivary duct stenosis following caudal maxillectomy.

    PubMed

    Mestrinho, Lisa A; Faísca, Pedro B; Niza, Maria M R E

    2014-01-01

    Parotid salivary duct dilation was diagnosed in a 9-year-old male dog. The dog had undergone caudal maxillectomy on the ipsilateral side 2-years prior to presentation. Treatment consisted of parotid salivary duct excision and superficial parotidectomy that lead to the resolution of clinical signs. Transient facial neuropraxia was observed immediately after surgery and resolved spontaneously after 2-weeks. Parotid salivary duct dilation should be considered as a chronic postoperative complication following caudal maxillectomy. PMID:24902412

  20. Lightweight Forms for Epoxy/Aramid Ducts

    NASA Technical Reports Server (NTRS)

    Mix, E. W.; Anderson, A. N.; Bedford, Donald L., Sr.

    1986-01-01

    Aluminum mandrels easy to remove. Lightweight aluminum mandrel for shaping epoxy/aramid ducts simplifies and speeds production. In new process, glass-reinforced epoxy/aramid cloth wrapped on aluminum mandrel. Stainless-steel flanges and other hardware fitted on duct and held by simple tooling. Entire assembly placed in oven to cure epoxy. After curing, assembly placed in alkaline bath dissolves aluminum mandrel in about 4 hours. Epoxy/aramid shell ready for use as duct. Aluminum mandrel used to make ducts of various inside diameters up to 6 in. Standard aluminum forms used. Conventional tube-bending equipment produces requisite curves in mandrels.

  1. Traumatic injury of the thoracic duct.

    PubMed

    Guzman, A E; Rossi, L; Witte, C L; Smyth, S

    2002-03-01

    Injuries to the thoracic duct are infrequent but may become life-threatening when chylous leakage persists. This report describes 6 patients with such injuries in whom the leakage resolved spontaneously in one, was corrected using microsurgical lymphatic repair or lymphatic-venous anastomosis in two, successfully treated either by ligation of the thoracic duct or insertion of a peritoneovenous shunt in two, and was eventually controlled after bilateral pleurodesis and thoracic duct ligation by insertion of a peritoneo-venous shunt in one. Conventional lymphography is superior to lymphoscintigraphy and is usually required to document disruption of the thoracic duct. PMID:11939572

  2. Generator stator core vent duct spacer posts

    DOEpatents

    Griffith, John Wesley; Tong, Wei

    2003-06-24

    Generator stator cores are constructed by stacking many layers of magnetic laminations. Ventilation ducts may be inserted between these layers by inserting spacers into the core stack. The ventilation ducts allow for the passage of cooling gas through the core during operation. The spacers or spacer posts are positioned between groups of the magnetic laminations to define the ventilation ducts. The spacer posts are secured with longitudinal axes thereof substantially parallel to the core axis. With this structure, core tightness can be assured while maximizing ventilation duct cross section for gas flow and minimizing magnetic loss in the spacers.

  3. Locating and Quantifying Broadband Fan Sources Using In-Duct Microphones

    NASA Technical Reports Server (NTRS)

    Dougherty, Robert P.; Walker, Bruce E.; Sutliff, Daniel L.

    2010-01-01

    In-duct beamforming techniques have been developed for locating broadband noise sources on a low-speed fan and quantifying the acoustic power in the inlet and aft fan ducts. The NASA Glenn Research Center's Advanced Noise Control Fan was used as a test bed. Several of the blades were modified to provide a broadband source to evaluate the efficacy of the in-duct beamforming technique. Phased arrays consisting of rings and line arrays of microphones were employed. For the imaging, the data were mathematically resampled in the frame of reference of the rotating fan. For both the imaging and power measurement steps, array steering vectors were computed using annular duct modal expansions, selected subsets of the cross spectral matrix elements were used, and the DAMAS and CLEAN-SC deconvolution algorithms were applied.

  4. Wastefree in-duct FGD

    SciTech Connect

    Nelson, S. Jr.

    1995-12-31

    The first generation of easily-retrofitable duct-injection technologies experienced problems with modest performance, particulate non-compliance, and difficult waste disposal. A new sorbent concept, called Fluesorbent, has been developed specifically to address these problems. Based on a new lime sorbent material, the technology results in 80+% SO{sub 2} removal, net particulate reductions, and a valuable agricultural by-product instead of wastes. A 6,500 acfm, 2-MWe Fluesorbent pilot plant was recently constructed at Ohio Edison`s R.E. Burger station. This paper describes the technology and the Burger demonstration project.

  5. 14 CFR 29.1103 - Induction systems ducts and air duct systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Induction systems ducts and air duct systems. 29.1103 Section 29.1103 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Induction System § 29.1103 Induction systems ducts and air...

  6. Optimization of the mechanical performance of a two-duct semicircular duct system--part 1: dynamics and duct dimensions.

    PubMed

    Muller, M; Verhagen, J H G

    2002-06-21

    The classical representation of the semicircular duct system consists of three separate duct circuits. The ducts are, however, in reality, hydrodynamically interconnected. Muller & Verhagen (1988a,b) derived equations for the mechanical behaviour of an interconnected system with three ducts (anterior, posterior and horizontal). An analytical solution of these equations would, however, be too complex to provide surveyable formulae. A system of two interconnected ducts avoids this complexity whilst keeping the essentials of the coupling of ducts intact. The solution of the equation of motion leads to expressions for time constants and maximal endolymph excursions which are functions of morphological parameters, viz. the ratios of radii (gamma) and lengths (lambda) of the common vestibular part (crus commune or utriculus) and the ducts. The system possesses two short time constants which are shown to have similar values. The maximum endolymph displacements in the two ducts after a steplike stimulus are the products of the respective initial velocities and combinations of time constants. The initial velocities depend strongly on the position of the labyrinth with respect to the excitating rotation vector. Measured data of gamma and lambda are compared with the theoretical results. For gamma, excellent agreement was found. lambda is treated elsewhere. PMID:12151258

  7. Measure Guideline: Sealing and Insulating of Ducts in Existing Homes

    SciTech Connect

    Aldrich, R.; Puttagunta, S.

    2011-12-01

    This document begins with a discussion on potential cost and performance benefits of duct sealing and insulating. It continues with a review of typical duct materials and components and the overall procedures for assessing and improving the duct system.

  8. What's New in Bile Duct Cancer Research and Treatment?

    MedlinePlus

    ... Topic Additional resources for bile duct cancer What’s new in bile duct cancer research and treatment? Bile ... is tumor blood vessels. Bile duct tumors need new blood vessels to grow beyond a certain size. ...

  9. Measure Guideline. Sealing and Insulating Ducts in Existing Homes

    SciTech Connect

    Aldrich, R.; Puttagunta, S.

    2011-12-01

    This document begins with a discussion on potential cost and performance benefits of duct sealing and insulating. It continues with a review of typical duct materials and components and the overall procedures for assessing and improving the duct system.

  10. Do We Know What Causes Bile Duct Cancer?

    MedlinePlus

    ... duct cancer be prevented? Do we know what causes bile duct cancer? We don’t know the exact cause of ... to top » Guide Topics What Is Bile Duct Cancer? Causes, Risk Factors, and Prevention Early Detection, Diagnosis, and ...

  11. Salivary duct carcinoma of parotid gland.

    PubMed

    Kinnera, Vijay Sreedhar Babu; Mandyam, Kumaraswamy Reddy; Chowhan, Amit Kumar; Nandyala, Rukmangadha; Bobbidi, Venkata Phaneendra; Vutukuru, Venkatarami Reddy

    2009-07-01

    A 40-year old male presented with rapidly growing swelling in the right parotid region. Based on the fine needle aspiration cytology report of adenocarcinoma not otherwise specified, superficial parotidectomy was performed, which showed the features of salivary duct carcinoma by histopathological examination. The smears were reviewed to identify the potential pitfalls in the cytological diagnosis of salivary duct carcinoma. PMID:21887008

  12. Salivary duct carcinoma of parotid gland

    PubMed Central

    Kinnera, Vijay Sreedhar Babu; Mandyam, Kumaraswamy Reddy; Chowhan, Amit Kumar; Nandyala, Rukmangadha; Bobbidi, Venkata Phaneendra; Vutukuru, Venkatarami Reddy

    2009-01-01

    A 40-year old male presented with rapidly growing swelling in the right parotid region. Based on the fine needle aspiration cytology report of adenocarcinoma not otherwise specified, superficial parotidectomy was performed, which showed the features of salivary duct carcinoma by histopathological examination. The smears were reviewed to identify the potential pitfalls in the cytological diagnosis of salivary duct carcinoma. PMID:21887008

  13. Double-duct liquid metal magnetohydrodynamic engine

    DOEpatents

    Haaland, Carsten M.

    1995-01-01

    An internal combustion, liquid metal (LM) magnetohydrodynamic (MHD) engine and an alternating current (AC) magnetohydrodynamic generator, are used in combination to provide useful AC electric energy output. The engine design has-four pistons and a double duct configuration, with each duct containing sodium potassium liquid metal confined between free pistons located at either end of the duct. The liquid metal is forced to flow back and forth in the duct by the movement of the pistons, which are alternatively driven by an internal combustion process. In the MHD generator, the two LM-MHD ducts pass in close proximity through a Hartmann duct with output transformer. AC power is produced by operating the engine with the liquid metal in the two generator ducts always flowing in counter directions. The amount of liquid metal maintained in the ducts may be varied. This provides a variable stroke length for the pistons. The engine/generator provides variable AC power at variable frequencies that correspond to the power demands of the vehicular propulsion. Also the engine should maintain nearly constant efficiency throughout the range of power usage. Automobiles and trucks could be powered by the invention, with no transmission or power converter devices being required.

  14. Double-duct liquid metal magnetohydrodynamic engine

    DOEpatents

    Haaland, Carsten M.

    1997-01-01

    An internal combustion, liquid metal (LM) magnetohydrodynamic (MHD) engine and an alternating current (AC) magnetohydrodynamic generator, are used in combination to provide useful AC electric energy output. The engine design has four pistons and a double duct configuration, with each duct containing sodium potassium liquid metal confined between free pistons located at either end of the duct. The liquid metal is forced to flow back and forth in the duct by the movement of the pistons, which are alternatively driven by an internal combustion process. In the MHD generator, the two LM-MHD ducts pass in close proximity through a Hartmann duct with output transformer. AC power is produced by operating the engine with the liquid metal in the two generator ducts always flowing in counter directions. The amount of liquid metal maintained in the ducts may be varied. This provides a variable stroke length for the pistons. The engine/generator provides variable AC power at variable frequencies that correspond to the power demands of the vehicular propulsion. Also the engine should maintain nearly constant efficiency throughout the range of power usage. Automobiles and trucks could be powered by the invention, with no transmission or power converter devices being required.

  15. Tear-Duct Obstruction and Surgery

    MedlinePlus

    ... could block a duct, but reconstructive surgery right after the accident or injury may prevent this. Signs of Blocked Tear Ducts ... kids. It may take up to a week after surgery before symptoms improve. Your doctor will give you antibiotic ointment or drops along with ... Injuries Pinkeye (Conjunctivitis) Retinopathy of Prematurity Preparing Your Child ...

  16. Predicting vibrational failure of flexible ducting

    NASA Technical Reports Server (NTRS)

    Henry, R. H.

    1971-01-01

    Technique applies to liquid or gas transfer through flexible ducting and proves valuable in high velocity fluid flow cases. Fluid mechanism responsible for free bellows vibrational excitation also causes flexible hose oscillation. Static pressure stress influences flexible ducting fatigue life and is considered separately.

  17. Rocket-in-a-Duct Performance Analysis

    NASA Technical Reports Server (NTRS)

    Schneider, Steven J.; Reed, Brian D.

    1999-01-01

    An axisymmetric, 110 N class, rocket configured with a free expansion between the rocket nozzle and a surrounding duct was tested in an altitude simulation facility. The propellants were gaseous hydrogen and gaseous oxygen and the hardware consisted of a heat sink type copper rocket firing through copper ducts of various diameters and lengths. A secondary flow of nitrogen was introduced at the blind end of the duct to mix with the primary rocket mass flow in the duct. This flow was in the range of 0 to 10% of the primary massflow and its effect on nozzle performance was measured. The random measurement errors on thrust and massflow were within +/-1%. One dimensional equilibrium calculations were used to establish the possible theoretical performance of these rocket-in-a-duct nozzles. Although the scale of these tests was small, they simulated the relevant flow expansion physics at a modest experimental cost. Test results indicated that lower performance was obtained at higher free expansion area ratios and longer ducts, while, higher performance was obtained with the addition of secondary flow. There was a discernable peak in specific impulse efficiency at 4% secondary flow. The small scale of these tests resulted in low performance efficiencies, but prior numerical modeling of larger rocket-in-a-duct engines predicted performance that was comparable to that of optimized rocket nozzles. This remains to be proven in large-scale, rocket-in-a-duct tests.

  18. Navier-Stokes analysis and experimental data comparison of compressible flow within ducts

    NASA Technical Reports Server (NTRS)

    Harloff, G. J.; Reichert, B. A.; Sirbaugh, J. R.; Wellborn, S. R.

    1992-01-01

    Many aircraft employ ducts with centerline curvature or changing cross-sectional shape to join the engine with inlet and exhaust components. S-ducts convey air to the engine compressor from the intake and often decelerate the flow to achieve an acceptable Mach number at the engine compressor by increasing the cross-sectional area downstream. Circular-to-rectangular transition ducts are used on aircraft with rectangular exhaust nozzles to connect the engine and nozzle. To achieve maximum engine performance, the ducts should minimize flow total pressure loss and total pressure distortion at the duct exit. Changes in the curvature of the duct centerline or the duct cross-sectional shape give rise to streamline curvature which causes cross stream pressure gradients. Secondary flows can be caused by deflection of the transverse vorticity component of the boundary layer. This vortex tilting results in counter-rotating vortices. Additionally, the adverse streamwise pressure gradient caused by increasing cross-sectional area can lead to flow separation. Vortex pairs have been observed in the exit planes of both duct types. These vortices are due to secondary flows induced by pressure gradients resulting from streamline curvature. Regions of low total pressure are produced when the vortices convect boundary layer fluid into the main flow. The purpose of the present study is to predict the measured flow field in a diffusing S-duct and a circular-to-rectangular transition duct with a full Navier-Stokes computer program, PARC3D, and to compare the numerical predictions with new detailed experimental measurements. The work was undertaken to extend previous studies and to provide additional CFD validation data needed to help model flows with strong secondary flow and boundary layer separation. The S-duct computation extends the study of Smith et al, and Harloff et al, which concluded that the computation might be improved by using a finer grid and more advanced turbulence models

  19. Salivary Duct Cyst: Histo-pathologic Correlation

    PubMed Central

    Vinayachandran, Divya; Sankarapandian, Sathasivasubramanian

    2013-01-01

    Non-neoplastic cysts of the salivary glands are uncommon and represent 2-5% of all salivary gland lesions. They are mainly mucoceles or salivary duct cysts. Unlike a mucocele, which is surrounded by granulation tissue, the salivary duct cyst is lined by epithelium. Salivary duct cysts are more common in the oral minor salivary glands and rarely occur in the major salivary glands, show a marked predilection for the superficial lobe of the parotid, and represent 10% of all salivary gland cysts. Neoplastic differentiation of the lining of the salivary duct cyst has been reported. We report a case of a salivary duct cyst of the left parotid gland, with a review of radiographic and histopathologic features. PMID:23878772

  20. Salivary Duct Cyst: Histo-pathologic Correlation.

    PubMed

    Vinayachandran, Divya; Sankarapandian, Sathasivasubramanian

    2013-01-01

    Non-neoplastic cysts of the salivary glands are uncommon and represent 2-5% of all salivary gland lesions. They are mainly mucoceles or salivary duct cysts. Unlike a mucocele, which is surrounded by granulation tissue, the salivary duct cyst is lined by epithelium. Salivary duct cysts are more common in the oral minor salivary glands and rarely occur in the major salivary glands, show a marked predilection for the superficial lobe of the parotid, and represent 10% of all salivary gland cysts. Neoplastic differentiation of the lining of the salivary duct cyst has been reported. We report a case of a salivary duct cyst of the left parotid gland, with a review of radiographic and histopathologic features. PMID:23878772

  1. Electromagnetic propagation in PEC and absorbing curved S-ducts

    NASA Technical Reports Server (NTRS)

    Baumeister, Kenneth J.

    1988-01-01

    A finite-element Galerkin formulation has been developed to study transverse magnetic (TM) wave propagation in 2-D S-curved ducts with both perfectly conducting and absorbing walls. The reflection and transmission at the entrances and the exits of the curved ducts are determined by coupling the finite-element solutions in the curved ducts to the eigenfunctions of an infinite, uniform, perfectly conducting duct. Example solutions are presented for a double mitred and S-ducts of various lengths. The length of the S-duct is found to significantly effect the reflective characteristics of the duct. Also, the effect of curvature on an absorbing duct is illustrated.

  2. Technology Solutions Case Study: Ducts Sealing Using Injected Spray Sealant

    SciTech Connect

    2014-03-01

    In multifamily and attached buildings, traditional duct sealing methods are often impractical or costly and disruptive because of the difficulty in accessing leakage sites. In this project, the Raleigh Housing Authority worked with Building America team, the Advanced Residential Integrated Solutions Collaborative to determine the most cost-effective ways to reduce duct leakage in its low-rise housing units.Two retrofit duct sealing techniques—manually-applied sealants and injecting a spray sealant—were implemented in several low-rise multiunit buildings. An analysis on the cost and performance of the two methods are presented. Each method was used in twenty housing units: approximately half of each group of units are single story and the remainder two-story. Results show that duct leakage to the outside was reduced by an average of 59% through the use of manual methods, and by 90% in the units where the injected spray sealant was used. Ihe cost of manually-applying sealant ranged from $275 to $511 per unit and for the injected spray sealant the cost was $700 per unit. Modeling suggests a simple payback of 2.2 years for manual sealing and 4.7 years for the injected spray sealant system. Utility bills were collected for one year before and after the retrofits. Utility bill analysis shows 14% and 16% energy savings using injected spray sealant system and hand sealing procedure respectively in heating season whereas in cooling season, energy savings using injected spray sealant system and hand sealing were both 16%.

  3. Techniques of Fluorescence Cholangiography During Laparoscopic Cholecystectomy for Better Delineation of the Bile Duct Anatomy

    PubMed Central

    Kono, Yoshiharu; Ishizawa, Takeaki; Tani, Keigo; Harada, Nobuhiro; Kaneko, Junichi; Saiura, Akio; Bandai, Yasutsugu; Kokudo, Norihiro

    2015-01-01

    Abstract To evaluate the clinical and technical factors affecting the ability of fluorescence cholangiography (FC) using indocyanine green (ICG) to delineate the bile duct anatomy during laparoscopic cholecystectomy (LC). Application of FC during LC began after laparoscopic fluorescence imaging systems became commercially available. In 108 patients undergoing LC, FC was performed by preoperative intravenous injection of ICG (2.5 mg) during dissection of Calot's triangle, and clinical factors affecting the ability of FC to delineate the extrahepatic bile ducts were evaluated. Equipment-related factors associated with bile duct detectability were also assessed among 5 laparoscopic systems and 1 open fluorescence imaging system in ex vivo studies. FC delineated the confluence between the cystic duct and common hepatic duct (CyD–CHD) before and after dissection of Calot's triangle in 80 patients (74%) and 99 patients (92%), respectively. The interval between ICG injection and FC before dissection of Calot's triangle was significantly longer in the 80 patients in whom the CyD–CHD confluence was detected by fluorescence imaging before dissection (median, 90 min; range, 15–165 min) than in the remaining 28 patients in whom the confluence was undetectable (median, 47 min; range, 21–205 min; P < 0.01). The signal contrast on the fluorescence images of the bile duct samples was significantly different among the laparoscopic imaging systems and tended to decrease more steeply than those of the open imaging system as the target-laparoscope distance increased and porcine tissues covering the samples became thicker. FC is a simple navigation tool for obtaining a biliary roadmap to reach the “critical view of safety” during LC. Key factors for better bile duct identification by FC are administration of ICG as far in advance as possible before surgery, sufficient extension of connective tissues around the bile ducts, and placement of the tip of

  4. Duct Remediation Program: Remediation operations and implementation

    SciTech Connect

    Beckman, T.d.; Davis, M.M.; Karas, T.M.

    1992-11-01

    Plutonium holdup material has accumulated in the process ventilation duct systems at Rocky Flats. Non-Destructive Assay (NDA) measurements identified ducts containing this material. The Defense Nuclear Facility Safety Board and the Department of Energy established the criteria for remediation of these ducts. A remediation team was assembled and a program plan created. This program plan included activities such as fissile material accumulation identification, criticality safety assessments, radiation dose determinations, facility safety evaluations, prevention of future accumulation, and removal of holdup material. Several operational considerations had to be evaluated in determining completion of remediation.

  5. Magnetospheric whistler ducts observed by ISIS satellites

    NASA Technical Reports Server (NTRS)

    Ondoh, T.

    1976-01-01

    The latitudinal width of the magnetospheric whistler duct has been estimated by the first and final invariant latitudes of whistler echoes and the conservation of the magnetic flux for the centered dipole field, using 105 whistler echoes in ISIS VLF data received at Kashima, Japan for 1972-1973. The latitudinal distribution of whistler duct occurrence shows a maximum at invariant latitudes of 40-45 degrees near the maximum occurrence latitude of ground whistlers. The radial width of magnetospheric whistler duct in the geomagnetically equatorial plane increases with invariant latitude of the geomagnetic flux tube in which whistlers propagate.

  6. Lapatinib in Treating Patients With Locally Advanced or Metastatic Biliary Tract or Liver Cancer That Cannot Be Removed By Surgery

    ClinicalTrials.gov

    2014-12-18

    Adult Primary Hepatocellular Carcinoma; Advanced Adult Primary Liver Cancer; Localized Unresectable Adult Primary Liver Cancer; Recurrent Adult Primary Liver Cancer; Recurrent Extrahepatic Bile Duct Cancer; Recurrent Gallbladder Cancer; Unresectable Extrahepatic Bile Duct Cancer; Unresectable Gallbladder Cancer

  7. Transmission of wave energy in curved ducts

    NASA Technical Reports Server (NTRS)

    Rostafinski, W.

    1973-01-01

    A formation of wave energy flow was developed for motion in curved ducts. A parametric study over a range of frequencies determined the ability of circular bends to transmit energy for the case of perfectly rigid walls.

  8. How Is Bile Duct Cancer Diagnosed?

    MedlinePlus

    ... line through which a different kind of contrast dye (IV contrast) is injected. This helps better outline ... common bile duct. A small amount of contrast dye is injected through the tube to help outline ...

  9. Treatment Options for Extrahepatic Bile Duct Cancer

    MedlinePlus

    ... checked to measure the amounts of bilirubin and alkaline phosphatase released into the blood by the liver. ... which a stent (a thin, flexible tube or metal tube) is placed in the bile duct to ...

  10. Treatment Option Overview (Extrahepatic Bile Duct Cancer)

    MedlinePlus

    ... checked to measure the amounts of bilirubin and alkaline phosphatase released into the blood by the liver. ... which a stent (a thin, flexible tube or metal tube) is placed in the bile duct to ...

  11. Stages of Extrahepatic Bile Duct Cancer

    MedlinePlus

    ... checked to measure the amounts of bilirubin and alkaline phosphatase released into the blood by the liver. ... which a stent (a thin, flexible tube or metal tube) is placed in the bile duct to ...

  12. Bile Duct (Cholangiocarcinoma) Cancer: Radiation Therapy

    MedlinePlus

    ... form of radiation for bile duct cancer. External beam radiation therapy (EBRT) This type of radiation therapy ... determine the correct angles for aiming the radiation beams and the proper dose of radiation. The treatment ...

  13. Intraoperative cholangiography and bile duct injury.

    PubMed

    Sarli, L; Costi, R; Roncoroni, L

    2006-01-01

    We are not in agreement with the opinion that the credit for excellent results after laparoscopic cholecystectomy is to be attributed to the routine performing of intraoperative cholangiography. We performed 2538 laparoscopic cholecystectomies without routine intraoperative cholangiography and we obtained very low rate and severity of common bile duct injuries: there was a total of four common bile duct injuries (0.16%), in no case was the injury a major transaction, and injuries were detected intraoperatively and easily repaired with a T-tube. Cholangiography could prevent bile duct transaction, but that it is not necessary for intraoperative cholangiography to be routinely performed for this purpose. It is sufficient for intraoperative cholangiography to be performed whenever the surgeon is in doubt as to the biliary anatomy or common bile duct clearance, and that when dissection of the cholecystic peduncle proves difficult he does not hesitate to convert to open access. PMID:16333543

  14. Investigation of heat transfer in porous duct

    NASA Astrophysics Data System (ADS)

    Athani, Abdulgaphur; Khan, T. M. Yunus

    2016-05-01

    Investigation of heat transfer in a square porous duct is carried out. The porous medium is sandwiched between inner and outer surface of a square duct. The flow is assumed to follow the Darcy law. The governing momentum and energy equations are non-dimensionalised and then converted to algebraic form of equations using finite element method. Galerkin method is used to transform the partial differential equations into simpler algebraic equations then solved in a iterative manner to arrive at the solution. The results are presented with respect to various geometric and physical parameters such as depth of porous medium, Rayleigh number etc. It is found that the isotherms and the streamlines take symmetrical position along the vertical central line of square duct. The isotherms are penetrated into deeper area at upper half of duct as compared to lower half.

  15. Model for coal dust duct explosions

    SciTech Connect

    Pickles, J.H.

    1982-01-01

    A theoretical discussion is given of the propagation of a dust explosion in a linear duct or pipeline. The particular aim is to investigate the experimental observation that propagating explosions are much harder to initiate in small laboratory scale ducts than in, say, coal mine galleries. A model is proposed in which a turbulent mixing phenomenon first identified by G.I. Taylor gives, for large ducts, very high flame velocities, which in turn lead to large fluid velocities and further increases in flame velocity. In small ducts, the time scale of the turbulent mixing is less than the time needed for the burning of individual coal particles. The particle burning time becomes an additional constraint on the rate of flame propagation and the development of explosions is inhibited.

  16. Rotating Rake Turbofan Duct Mode Measurement System

    NASA Technical Reports Server (NTRS)

    Sutliff, Daniel L.

    2005-01-01

    An experimental measurement system was developed and implemented by the NASA Glenn Research Center in the 1990s to measure turbofan duct acoustic modes. The system is a continuously rotating radial microphone rake that is inserted into the duct. This Rotating Rake provides a complete map of the acoustic duct modes present in a ducted fan and has been used on a variety of test articles: from a low-speed, concept test rig, to a full-scale production turbofan engine. The Rotating Rake has been critical in developing and evaluating a number of noise reduction concepts as well as providing experimental databases for verification of several aero-acoustic codes. More detailed derivation of the unique Rotating Rake equations are presented in the appendix.

  17. [Isolated neurofibroma of the common bile duct].

    PubMed

    Carbia, S; Pagola, J; Flaster, N; Guida, A; Jufe, L; González, B; Caniparoli, A

    1995-01-01

    The neurogenic tumors in the biliary tract are rare and usually are amputation neuroma that occur after cholecystectomy. We describe a case of isolated neurofibroma of the common bile duct in a young man not cholecystectomized. The patient suffered recurrent episodes of abdominal pain, vomiting and weight loss without clinical signs of Von Recklinghausen's disease or jaundice. The hepatogram was normal. The echography indicated a solid formation with obstruction of the proximal common bile duct. In the ERCP the stenosis was found. Surgical excision of the tumor and anastomosis of bilateral hepatic ducts and jejunum were carried out. At microscopic examination intraparietal neurofibroma of the common bile duct was found. As isolated entity, we know of only one reported case. PMID:8731581

  18. INTERIOR DUCT SYSTEM DESIGN, CONSTRUCTION, AND PERFORMANCE

    SciTech Connect

    Janet E.R. Mcllvaine; David Beal; Philip Fairey

    2001-10-10

    By removing air distribution and conditioning equipment from unconditioned spaces, homeowners stand to benefit substantially with respect to both energy savings and indoor air quality. Duct leakage introduces: Greater heating and cooling loads from air at extreme temperatures and humidity levels; Outside air and air from unconditioned spaces that may contain air borne contaminants, combustion gases, pollen, mold spores, and/or particles of building materials; and Higher whole-house infiltration/exfiltration rates. Exemplary studies conducted since 1990 have demonstrated the prevalence of duct leakage throughout the United States and measured energy savings of approximately 20% during both heating and cooling seasons from leakage reduction. These all dealt with duct leakage to and/or from unconditioned spaces. In the building science community, leakage within the conditioned space is generally presumed to eliminate the negative consequences of duct leakage with the exception of possibly creating pressure imbalances in the house which relates to higher infiltration and/or exfiltration. The practical challenges of isolating ducts and air handlers from unconditioned spaces require builders to construct an air-tight environment for the ducts. Florida Solar Energy Center researchers worked with four builders in Texas, North Carolina, and Florida who build a furred-down chase located either in a central hallway or at the edges of rooms as an architectural detail. Some comparison homes with duct systems in attics and crawl spaces were included in the test group of more than 20 homes. Test data reveals that all of the duct/AHU systems built inside the conditioned space had lower duct leakage to unconditioned spaces than their conventional counterparts; however, none of the homes was completely free of duct leakage to unconditioned spaces. Common problems included wiring and plumbing penetrations of the chase, failure to treat the chase as an air tight space, and misguided

  19. Propagation Of Sound In Curved Ducts

    NASA Technical Reports Server (NTRS)

    Rostafinski, Wojciech

    1992-01-01

    Monograph presents concise, comprehensive summary of knowledge of propagation of acoustic waves in ducts and pipes including bends. Pulls together information from Lord Rayleigh's book Theory Of Sound, published in 1878, and from 33 papers scattered throughout various scientific journals published between 1945 and 1989. Monograph useful to scientists and engineers interested in such diverse topics as musical instruments, air-conditioning ducts, and jet engines. Material not available in current texts.

  20. Evaporation duct communication: Test plan, part 2

    NASA Astrophysics Data System (ADS)

    Anderson, K. D.; Rogers, L. T.

    1991-11-01

    This document is a continuation and expansion of an earlier study that examines the feasibility of using the evaporation duct to support an alternative high-speed communication system for Navy applications. This Evaporation Duct Communication (EDCOM) experiment is a unique opportunity to evaluate another communication channel that can alleviate Navy ship-to-ship communication problems. Therefore, it is strongly recommended to proceed with this measurement program.

  1. A Comparison of Simulation Capabilities for Ducts

    SciTech Connect

    Miller, William A.; Smith, Matt K.; Gu, Lixing; New, Joshua Ryan

    2014-11-01

    Typically, the cheapest way to install a central air conditioning system in residential buildings is to place the ductwork in the attic. Energy losses due to duct-attic interactions can be great, but current whole-house models are unable to capture the dynamic multi-mode physics of the interactions. The building industry is notoriously fragmented and unable to devote adequate research resources to solve this problem. Builders are going to continue to put ducts in the attic because floor space is too expensive to closet them within living space, and there are both construction and aesthetic issues with other approaches such as dropped ceilings. Thus, there is a substantial need to publicly document duct losses and the cost of energy used by ducts in attics so that practitioners, builders, homeowners and state and federal code officials can make informed decisions leading to changes in new construction and additional retrofit actions. Thus, the goal of this study is to conduct a comparison of AtticSim and EnergyPlus simulation algorithms to identify specific features for potential inclusion in EnergyPlus that would allow higher-fidelity modeling of HVAC operation and duct transport of conditioned air. It is anticipated that the resulting analysis from these simulation tools will inform energy decisions relating to the role of ducts in future building energy codes and standards.

  2. Mucoepidermoid carcinoma in a thyroglossal duct remnant

    PubMed Central

    Warner, E.; Ofo, E.; Connor, S.; Odell, E.; Jeannon, J.P.

    2015-01-01

    Introduction Thyroglossal duct cysts (TDC) are common midline neck swellings resulting from embryological remnants of the thyroglossal duct. They often contain ectopic thyroid tissue and malignant transformation has been reported, most commonly to papillary thyroid carcinoma. Mucoepidermoid carcinoma (MEC) usually occurs in the salivary glands and only rarely in the thyroid. This is the first case of a MEC occurring within a thyroglossal duct remnant. Presentation of a case A 73 year old lady presented with a thyroglossal duct cyst. She declined surgical excision, as she was adamant she wanted to avoid surgery. The neck mass rapidly enlarged at two years following initial diagnosis. Fine needle aspiration cytology was suspicious for carcinoma. She underwent total thyroidectomy and selective central compartment neck dissection with adjuvant radiotherapy. She remains alive and well two years post treatment. Discussion Mucoepidermoid carcinoma is the most common malignant neoplasm of salivary glands, although it has rarely been reported in diverse locations including the thyroid, lung and pancreas. To the best of our knowledge, this is the first reported case of mucoepidermoid carcinoma arising from a thyroglossal duct remnant. Conclusion This case adds weight to the literature favouring surgical excision of thyroglossal duct remnants due to the risk of malignant transformation. PMID:26101054

  3. Bile Duct Injury-from Injury to Repair: an Analysis of Management and Outcome.

    PubMed

    Mishra, Pramod Kumar; Saluja, Sundeep Singh; Nayeem, Mohammed; Sharma, Barjesh Chander; Patil, Nilesh

    2015-12-01

    Despite advances in speciality care, mortality and morbidity remain the most important issues in the management of post-cholecystectomy bile duct injuries. We analysed the peri-operative management of post-cholecystectomy bile duct injuries to assess their outcomes. Of 150 patients with post-cholecystectomy bile duct injuries, 13 patients who presented with strictured hepaticojejunostomy were excluded from the analysis. The records of the remaining 137 patients were analysed for type of presentation, management and follow-up. Of 137 injuries, 88 were open and 49 were laparoscopic. Various presentations include acute bile duct injury (n = 5), bile collection (n = 45), external biliary fistula (n = 46) and stricture (n = 41). After initial management, three patients died (sepsis, n = 2; pseudoaneurysmal bleed, n = 1). Of 107 patients who underwent definitive repair, three died (portal hypertension, n = 2; sepsis, n = 1). At median follow-up of 30 months, 100 patients had good outcome (grade A, B), and only 4 had bad outcome (grade C, D) as per McDonald grading. Peritonitis and sepsis in the early phase and portal hypertension and cirrhosis in the late phase are the main causes of mortality in patients sustaining bile duct injury during cholecystectomy. Successful management in a specialist hepatobiliary centre can limit the morbidity in more than 90 % cases. PMID:26730060

  4. Size limitations in semicircular duct systems

    PubMed

    Muller

    1999-06-01

    The present article discusses mechanical requirements and limitations which are applicable to the construction of the system of semicircular ducts, especially to its size. The simplified case of a single, uniform duct system has been considered which can be described by a second order equation of motion. The principal functional quantities for this rotation-sensor are: (1) response speed; (2) sensitivity; and (3) regular flow. The response speed of a single, uniform semicircular duct is characterized by the short time constant (T2) which is dependent on the duct radius (r). Its estimated range is from 0.04 ms in the smallest to 140 ms in the largest known labyrinth. The sensitivity is characterized by the maximal endolymph displacement after a step stimulus (xmax). Its estimated range is from 0.0016 &mgr;m to 5.97 mm (6.56 decades!), assuming an input angular velocity of omega=1 rad s-1. The Reynolds number is a measure for an undisturbed laminar flow. Its estimated range varies from 7.38.10(-4)to 45.1 for omega=1 rad s-1. The above data follow from graphs in which, for a single uniform duct, circuit radius (R) is plotted against duct radius (r) for labyrinths of 233 species belonging to different vertebrate-groups. A relation R =38.9. r1.60was determined. The smallest labyrinth was found in a carp larva (Cyprinus), the largest in a whale shark (Rhincodon). Large whales possess labyrinths of average mammalian size. It is revealed that semicircular duct size is bound by requirements concerning regular flow and by a too low response speed for large labyrinths, and by a too low sensitivity for small labyrinths. Other important quantities are mechanical amplification factors which are a consequence of more complex vestibular constructions than a single uniform duct circuit. Allometric relationships are interpreted as compromises between the quantities mentioned. A hypothesis for the relatively large semicircular duct sizes of fishes, especially Elasmobranchii, compared

  5. Remodeling of the Fetal Collecting Duct Epithelium

    PubMed Central

    Hiatt, Michael J.; Ivanova, Larissa; Toran, Nuria; Tarantal, Alice F.; Matsell, Douglas G.

    2010-01-01

    Congenital urinary tract obstruction induces changes to the renal collecting duct epithelium, including alteration and depletion of intercalated cells. To study the effects of obstruction on the ontogeny of intercalated cell development, we examined normal and obstructed human fetal and postnatal kidneys. In the normal human fetal kidney, intercalated cells originated in the medullary collecting duct at 8 weeks gestation and remained most abundant in the inner medulla throughout gestation. In the cortex, intercalated cells were rare at 18 and 26 weeks gestation and observed at low abundance at 36 weeks gestation. Although early intercalated cells exhibit an immature phenotype, Type A intercalated cells predominated in the inner and outer medullae at 26 and 36 weeks gestation with other intercalated cell subtypes observed rarely. Postnatally, the collecting duct epithelium underwent a remodeling whereby intercalated cells become abundant in the cortex yet absent from the inner medulla. In 18-week obstructed kidneys with mild to moderate injury, the intercalated cells became more abundant and differentiated than the equivalent age-matched normal kidney. In contrast, more severely injured ducts of the late obstructed kidney exhibited a significant reduction in intercalated cells. These studies characterize the normal ontogeny of human intercalated cell development and suggest that obstruction induces premature remodeling and differentiation of the fetal collecting duct epithelium. PMID:20035053

  6. Convolution seal for transition duct in turbine system

    SciTech Connect

    Flanagan, James Scott; LeBegue, Jeffrey Scott; McMahan, Kevin Weston; Dillard, Daniel Jackson; Pentecost, Ronnie Ray

    2015-05-26

    A turbine system is disclosed. In one embodiment, the turbine system includes a transition duct. The transition duct includes an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The transition duct further includes an interface feature for interfacing with an adjacent transition duct. The turbine system further includes a convolution seal contacting the interface feature to provide a seal between the interface feature and the adjacent transition duct.

  7. User's Manual for DuctE3D: A Program for 3D Euler Unsteady Aerodynamic and Aeroelastic Analysis of Ducted Fans

    NASA Technical Reports Server (NTRS)

    Srivastava, R.; Reddy, T. S. R.

    1997-01-01

    The program DuctE3D is used for steady or unsteady aerodynamic and aeroelastic analysis of ducted fans. This guide describes the input data required and the output files generated, in using DuctE3D. The analysis solves three dimensional unsteady, compressible Euler equations to obtain the aerodynamic forces. A normal mode structural analysis is used to obtain the aeroelastic equations, which are solved using either the time domain or the frequency domain solution method. Sample input and output files are included in this guide for steady aerodynamic analysis and aeroelastic analysis of an isolated fan row.

  8. Film condensation in a horizontal rectangular duct

    NASA Technical Reports Server (NTRS)

    Lu, Qing; Suryanarayana, N. V.

    1993-01-01

    Condensation heat transfer in a horizontal rectangular duct was experimentally and analytically investigated. To prevent the dripping of condensate on the film, the experiment was conducted inside a horizontal rectangular duct with vapor condensing only on the bottom cooled plate of the duct. R-113 and FC-72 (Fluorinert Electronic Fluid developed by the 3M Company) were used as the condensing fluids. The experimental program included measurements of film thickness, local and average heat transfer coefficients, wave length, wave speed, and a study of wave initiation. The measured film thickness was used to obtain the local heat transfer coefficient. The wave initiation was studied both with condensation and with an adiabatic air-liquid flow. The test sections used in both experiments were identical.

  9. "Mustache sign" due to Stensen duct dilation.

    PubMed

    Yoruk, O; Kılıc, K; Kantarcı, M

    2013-12-01

    An 80-year-old woman presented with a 5-year history of painless swellings of the left and right cheeks. The degree of swelling did not change with mastication. On palpation, the cheeks were soft, well defined, and movable. Compression and massage of the swollen areas caused increased salivary discharge from the orifices of the Stensen ducts. Three-dimensional computed tomography showed well-bordered, 15- to 20-mm wide, bilateral, tube-like dilatations of the ducts. The ductal origin of the swellings was explained to the patient, but she refused invasive procedures, thus no sialogram or surgical procedure was performed. We describe the clinical and radiographic features of a case of bilateral, congenital Stensen duct dilatation with bilateral swelling of the cheeks. PMID:24209996

  10. Acoustic energy in ducts - Further observations

    NASA Technical Reports Server (NTRS)

    Eversman, W.

    1979-01-01

    The transmission of acoustic energy in uniform ducts carrying uniform flow is investigated with the purpose of clarifying two points of interest. The two commonly used definitions of acoustic 'energy' flux are shown to be related by a Legendre transformation of the Lagrangian density exactly as in deriving the Hamiltonian density in mechanics. In the acoustic case the total energy density and the Hamiltonian density are not the same which accounts for two different 'energy' fluxes. When the duct has acoustically absorptive walls neither of the two flux expressions gives correct results. A reevaluation of the basis of derivation of the energy density and energy flux provides forms which yield consistent results for soft walled ducts.

  11. Computing Propagation Of Sound In Engine Ducts

    NASA Technical Reports Server (NTRS)

    Saylor, Silvia

    1995-01-01

    Frequency Domain Propagation Model (FREDOM) computer program accounts for acoustic loads applied to components of engines. Models propagation of noise through fluids in ducts between components and through passages within components. Used not only to analyze hardware problems, but also for design purposes. Updated version of FREQPL program easier to use. Devised specifically for use in analyzing acoustic loads in rocket engines. Underlying physical and mathematical concepts implemented also applicable to acoustic propagation in other enclosed spaces; analyzing process plumbing and ducts in industrial buildings with view toward reducing noise in work areas.

  12. Fundamental investigation of duct/ESP phenomena

    SciTech Connect

    Brown, C.A. ); Durham, M.D. ); Sowa, W.A. . Combustion Lab.); Himes, R.M. ); Mahaffey, W.A. )

    1991-10-21

    Radian Corporation was contracted to investigate duct injection and ESP phenomena in a 1.7 MW pilot plant constructed for this test program. This study was an attempt to resolve problems found in previous studies and answer remaining questions for the technology using an approach which concentrates on the fundamental mechanisms of the process. The goal of the study was to obtain a better understanding of the basic physical and chemical phenomena that control: (1) the desulfurization of flue gas by calcium-based reagent, and (2) the coupling of an existing ESP particulate collection device to the duct injection process. Process economics are being studied by others. (VC)

  13. Preconditioning the Helmholtz Equation for Rigid Ducts

    NASA Technical Reports Server (NTRS)

    Baumeister, Kenneth J.; Kreider, Kevin L.

    1998-01-01

    An innovative hyperbolic preconditioning technique is developed for the numerical solution of the Helmholtz equation which governs acoustic propagation in ducts. Two pseudo-time parameters are used to produce an explicit iterative finite difference scheme. This scheme eliminates the large matrix storage requirements normally associated with numerical solutions to the Helmholtz equation. The solution procedure is very fast when compared to other transient and steady methods. Optimization and an error analysis of the preconditioning factors are present. For validation, the method is applied to sound propagation in a 2D semi-infinite hard wall duct.

  14. Congenital Atresia of Wharton’s Duct

    PubMed Central

    Hseu, Anne; Anne, Premchand

    2016-01-01

    This is a case report of a three-month-old male who presented to clinic with a cystic lesion under the tongue. On clinical examination, a cystic lesion was observed in the, floor-of-mouth. The patient was referred to Paediatric Otorhinolaryngology service for further management. The differential diagnoses for floor-of-mouth lesions should be reviewed with primary focus on the Wharton’s duct atresia and its management. It is crucial to recognize submandibular duct atresia in the primary Paediatric clinic in order to expedite management of lesion before complications arise including infection, enlargement of cyst, and feeding and breathing difficulties. PMID:27042492

  15. Limits of Surgical Resection for Bile Duct Cancer

    PubMed Central

    Bartsch, Fabian; Heinrich, Stefan; Lang, Hauke

    2015-01-01

    Introduction Perihilar cholangiocarcinoma is the most frequent cholangiocarcinoma and poses difficulties in preoperative evaluation. For its therapy, often major hepatic resections as well as resection and reconstruction of the hepatic artery or the portal vein are necessary. In the last decades, great advances were made in both the surgical procedures and the perioperative anesthetic management. In this article, we describe from our point of view which facts represent the limits for curative (R0) resection in perihilar cholangiocarcinoma. Methods Retrospective data of a 6-year period (2008-2014) was collected in an SPSS 22 database and further analyzed with focus on the surgical approach and the postoperative as well as histological results. Results Out of 96 patients in total we were able to intend a curative resection in 73 patients (76%). In 58/73 (79.5%) resections an R0 situation could be reached (R1 n = 14; R2 n = 1). 23 patients were irresectable because of peritoneal carcinosis (n = 8), broad infiltration of major blood vessels (n = 8), bilateral advanced tumor growth to the intrahepatic bile ducts (n = 3), infiltration of the complete liver hilum (n = 2), infiltration of the gallbladder (n = 1), and liver cirrhosis (n = 1). Patients with a T4 stadium were treated with curative intention twice, and in each case an R1 resection was achieved. Most patients with irresectable tumors can be suspected to have a T4 stadium as well. In a T3 situation (n = 6) we could establish five R0 resections and one R1 resection. Conclusion The limit of surgical resection for bile duct cancer is the advanced tumor stage (T stadium). While in a T3 stadium an R0 resection is possible in most cases, we were not able to perform an R0 resection in a T4 stadium. From our point of view, early T stadium cannot usually be estimated through expanded diagnostics but only through surgical exploration. PMID:26468314

  16. What Should You Ask Your Doctor about Bile Duct Cancer?

    MedlinePlus

    ... treatment for bile duct cancer? What should you ask your doctor about bile duct cancer? It is ... your own. For instance, you might want to ask about clinical trials for which you may qualify. ...

  17. Experimental evaluation of a pilot multinozzle-duct apparatus

    NASA Technical Reports Server (NTRS)

    Puster, R. L.

    1979-01-01

    A pilot multinozzle and duct were tested at ambient enthalpy to evaluate the suitability of such apparatus for testing thermal protection system panels mounted in the sidewalls of the duct downstream of the nozzle array. The flow field in the duct was complex: effects of wakes and shock waves from the nozzle dominated the flow field; the wakes continually mixed with the surrounding fluid; the boundary layer on the sidewalls of the duct was nonuniform; and near the exit of the duct the sidewall pressure variation was as much as 8.5 percent about the mean wall pressure. Starting loads on the duct walls were higher than those of a similar conventional nozzle and duct. It was concluded that the multinozzle-duct apparatus was not suitable for testing TPS panels, although the design and flow-field information should be of interest to designers of high-energy gasdynamic lasers.

  18. Low-cost orbiting grinder for cutting ducts

    NASA Technical Reports Server (NTRS)

    Lang, E. J.

    1970-01-01

    Low-cost, portable machine cuts ducts made from heat-treated alloys. An abrasive wheel, powered by a high-speed air motor mounted on an expandible plug against the inner wall of the duct, gives precise cutting.

  19. Thyroglossal Duct Carcinoma in a Cat.

    PubMed

    Moorer, Jeremiah D; Breshears, Melanie A; Dugat, Danielle R

    2016-01-01

    A 14 yr old castrated domestic shorthair cat presented for a fluid-filled structure in the ventral cervical region that had been present for 1 yr and had not resolved after repeated aspiration and drainage. Cervical computed tomography showed an approximately 10 cm, fluid-filled, multilobulated mass located on the ventrolateral right side of the cervical region extending into the thoracic inlet. Cytologic examination of the fluid revealed cystic fluid with evidence of chronic hemorrhage. The mass was surgically removed, and histopathologic examination revealed a thyroglossal duct carcinoma. Thyroid and parathyroid gland origin were ruled out by negative immunohistochemical staining for thyroglobulin, parathyroid hormone, calcitonin, and synaptophysin. No adjunctive treatment was performed and no recurrence was noted at 14 mo. Thyroglossal duct carcinoma has not been previously reported in a cat. There are two previous reports of squamous cell carcinoma of the thyroglossal duct in dogs. In humans, with complete removal and no evidence of metastasis, carcinoma of the thyroglossal duct has a good prognosis for recovery. PMID:27259027

  20. Idea Bank: Duct Tape Note Twister

    ERIC Educational Resources Information Center

    McHenry, Molly

    2008-01-01

    In this article, the author relates how she observed a middle school math teacher deliver a miserable class. She realized that she did the same thing to her music students. To engage her students, she developed "Note Twister," a music reading game using duct tape to form musical notes and the basic premise behind the game, "Twister." She finds…

  1. Starting flow in regular polygonal ducts

    NASA Astrophysics Data System (ADS)

    Wang, C. Y.

    2016-06-01

    The starting flows in regular polygonal ducts of S = 3, 4, 5, 6, 8 sides are determined by the method of eigenfunction superposition. The necessary S-fold symmetric eigenfunctions and eigenvalues of the Helmholtz equation are found either exactly or by boundary point match. The results show the starting time is governed by the first eigenvalue.

  2. Thoracoscopic Ligation of the Thoracic Duct

    PubMed Central

    Teixeira, Julio A.

    2000-01-01

    Objective: When nonoperative treatment of chylothorax fails, thoracic duct ligation is usually performed through a thoracotomy. We describe two cases of persistent chylothorax, in a child and an adult, successfully treated with thoracoscopic ligation of the thoracic duct. Methods: A 4-year-old girl developed a right chylothorax following a Fontan procedure. Aggressive nonoperative management failed to eliminate the persistent chyle loss. A 72-year-old insulin-dependent diabetic man was involved in a motor vehicle accident, in which he sustained multiple fractured ribs, a right hemopneumothorax, a right femoral shaft fracture, and a T-11 thoracic vertebral fracture. Subsequently, he developed a right chylothorax, which did not respond to nonoperative management. Both patients were successfully treated with thoracoscopic ligation of the thoracic duct. Results: The child had significant decrease of chyle drainage following surgery. Increased drainage that appeared after the introduction of full feedings five days postoperatively was controlled with the somatostatin analog octreotide. The chest tube was removed two weeks after surgery. After two years' follow-up, she has had no recurrence of chylothorax. The adult had no chyle drainage following surgery. He was maintained on a medium-chain triglyceride diet postoperatively for two weeks. The chest tube was removed four days after surgery. After six months' follow-up, he has had no recurrence of chylothorax. Conclusions: Thoracoscopic ligation of the thoracic duct provides a safe and effective treatment of chylothorax and may avoid thoracotomy and its associated morbidity. PMID:10987402

  3. 46 CFR 116.610 - Ventilation ducts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... prevent corrosion; (4) Fire dampers must be capable of manual operation from outside the space served, be... damper, automatic damper, or vent cover, must be provided in an accessible location outside the space... duct penetrating an A-Class fire control boundary and opening into a space formed by that boundary...

  4. 46 CFR 116.610 - Ventilation ducts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... prevent corrosion; (4) Fire dampers must be capable of manual operation from outside the space served, be... damper, automatic damper, or vent cover, must be provided in an accessible location outside the space... duct penetrating an A-Class fire control boundary and opening into a space formed by that boundary...

  5. Detonation duct gas generator demonstration program

    NASA Technical Reports Server (NTRS)

    Wortman, Andrew; Brinlee, Gayl A.; Othmer, Peter; Whelan, Michael A.

    1991-01-01

    The feasibility of the generation of detonation waves moving periodically across high speed channel flow is experimentally demonstrated. Such waves are essential to the concept of compressing requirements and increasing the engine pressure compressor with the objective of reducing conventional compressor requirements and increasing the engine thermodynamic efficiency through isochoric energy addition. By generating transient transverse waves, rather than standing waves, shock wave losses are reduced by an order of magnitude. The ultimate objective is to use such detonation ducts downstream of a low pressure gas turbine compressor to produce a high overall pressure ratio thermodynamic cycle. A 4 foot long, 1 inch x 12 inch cross-section, detonation duct was operated in a blow-down mode using compressed air reservoirs. Liquid or vapor propane was injected through injectors or solenoid valves located in the plenum or the duct itself. Detonation waves were generated when the mixture was ignited by a row of spark plugs in the duct wall. Problems with fuel injection and mixing limited the air speeds to about Mach 0.5, frequencies to below 10 Hz, and measured pressure ratios of about 5 to 6. The feasibility of the gas dynamic compression was demonstrated and the critical problem areas were identified.

  6. Sound attenuation of fiberglass lined ventilation ducts

    NASA Astrophysics Data System (ADS)

    Albright, Jacob

    Sound attenuation is a crucial part of designing any HVAC system. Most ventilation systems are designed to be in areas occupied by one or more persons. If these systems do not adequately attenuate the sound of the supply fan, compressor, or any other source of sound, the affected area could be subject to an array of problems ranging from an annoying hum to a deafening howl. The goals of this project are to quantify the sound attenuation properties of fiberglass duct liner and to perform a regression analysis to develop equations to predict insertion loss values for both rectangular and round duct liners. The first goal was accomplished via insertion loss testing. The tests performed conformed to the ASTM E477 standard. Using the insertion loss test data, regression equations were developed to predict insertion loss values for rectangular ducts ranging in size from 12-in x 18-in to 48-in x 48-in in lengths ranging from 3ft to 30ft. Regression equations were also developed to predict insertion loss values for round ducts ranging in diameters from 12-in to 48-in in lengths ranging from 3ft to 30ft.

  7. Turbofan aft duct suppressor study program listing and user's guide

    NASA Technical Reports Server (NTRS)

    Joshi, M. C.; Kraft, R. E.

    1983-01-01

    A description of the structure of the Annular Flow Duct Program (AFDP) for the calculation of acoustic suppression due to treatment in a finite length annular duct carrying sheared flow is presented. Although most appropriate for engine exhaust ducts, this program can be used to study sound propagation in any duct that maintains annular geometry over a considerable length of the duct. The program is based on the modal analysis of sound propagation in ducts with axial segments of different wall impedances. For specified duct geometry, wall impedance, flow and acoustic conditions in the duct (including mode amplitude distribution of the source) and duct termination reflection characteristics, the program calculates the suppression due to the treatment in the duct. The presence of forward and backward traveling modes in the duct due to the reflection and redistribution of modes at segment interfaces and duct end terminations are taken into account in the calculations. The effects of thin wall boundary layers (with a linear or mean flow velocity profile) on the acoustic propagation are also included in the program. A functional description of the major subroutines is included and a sample run is provided with an explanation of the output.

  8. A bidirectional microphone for the measurement of duct noise

    NASA Astrophysics Data System (ADS)

    La Fontaine, R. F.; Shepherd, I. C.; Cabelli, A.

    1985-08-01

    A bidirectional microphone which resolves acoustic plane waves in ducts into forward and backward propagating components is described. The microphone has a flat frequency response and finds applications in the analysis of duct noise and in the determination of reflection coefficients for various duct configurations. It can also be employed as a unidirectional microphone in active noise attenuators.

  9. 14 CFR 25.1103 - Induction system ducts and air duct systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... between the air duct source and the airplane unit served by the air. (e) Each auxiliary power unit... other compartment or area of the airplane in which a hazard would be created resulting from the entry...

  10. 14 CFR 25.1103 - Induction system ducts and air duct systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... between the air duct source and the airplane unit served by the air. (e) Each auxiliary power unit... other compartment or area of the airplane in which a hazard would be created resulting from the entry...

  11. 14 CFR 25.1103 - Induction system ducts and air duct systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... the auxiliary power unit must be capable of resisting the maximum heat conditions likely to occur. (f) Each auxiliary power unit induction system duct must be constructed of materials that will not...

  12. 14 CFR 25.1103 - Induction system ducts and air duct systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... the auxiliary power unit must be capable of resisting the maximum heat conditions likely to occur. (f) Each auxiliary power unit induction system duct must be constructed of materials that will not...

  13. 14 CFR 29.1103 - Induction systems ducts and air duct systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... resisting the maximum heat conditions likely to occur. (f) Each auxiliary power unit induction system duct must be constructed of materials that will not absorb or trap hazardous quantities of flammable...

  14. 14 CFR 29.1103 - Induction systems ducts and air duct systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... resisting the maximum heat conditions likely to occur. (f) Each auxiliary power unit induction system duct must be constructed of materials that will not absorb or trap hazardous quantities of flammable...

  15. 14 CFR 25.1103 - Induction system ducts and air duct systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... the auxiliary power unit must be capable of resisting the maximum heat conditions likely to occur. (f) Each auxiliary power unit induction system duct must be constructed of materials that will not...

  16. 14 CFR 29.1103 - Induction systems ducts and air duct systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... resisting the maximum heat conditions likely to occur. (f) Each auxiliary power unit induction system duct must be constructed of materials that will not absorb or trap hazardous quantities of flammable...

  17. Combined Endoscopic and Laparoscopic Management of Postcholecystectomy Mirizzi Syndrome from a Remnant Cystic Duct Stone: Case Report and Review of the Literature.

    PubMed

    Amin, Arpit; Zhurov, Yuriy; Ibrahim, George; Maffei, Anthony; Giannone, Jonathan; Cerabona, Thomas; Kaul, Ashutosh

    2016-01-01

    Mirizzi syndrome has been defined in the literature as common bile duct obstruction resulting from calculi within Hartmann's pouch or cystic duct. We present a case of a 78-year-old female, who developed postcholecystectomy Mirizzi syndrome from a remnant cystic duct stone. Diagnosis of postcholecystectomy Mirizzi syndrome was made on endoscopic retrograde cholangiography (ERCP) performed postoperatively. The patient was treated with a novel strategy by combining advanced endoscopic and laparoscopic techniques in three stages as follows: Stage 1 (initial presentation): endoscopic sphincterotomy with common bile duct stent placement; Stage 2 (6 weeks after Stage 1): laparoscopic ultrasonography to locate the remnant cystic duct calculi followed by laparoscopic retrieval of the calculi and intracorporeal closure of cystic duct stump; Stage 3 (6 weeks after Stage 2): endoscopic removal of common bile duct stent along with performance of completion endoscopic retrograde cholangiogram. In addition, we have performed an extensive review of the various endoscopic and laparoscopic management techniques described in the literature for the treatment of postcholecystectomy syndrome occurring from retained cystic duct stones. PMID:27047698

  18. Combined Endoscopic and Laparoscopic Management of Postcholecystectomy Mirizzi Syndrome from a Remnant Cystic Duct Stone: Case Report and Review of the Literature

    PubMed Central

    Amin, Arpit; Zhurov, Yuriy; Ibrahim, George; Maffei, Anthony; Giannone, Jonathan; Cerabona, Thomas; Kaul, Ashutosh

    2016-01-01

    Mirizzi syndrome has been defined in the literature as common bile duct obstruction resulting from calculi within Hartmann's pouch or cystic duct. We present a case of a 78-year-old female, who developed postcholecystectomy Mirizzi syndrome from a remnant cystic duct stone. Diagnosis of postcholecystectomy Mirizzi syndrome was made on endoscopic retrograde cholangiography (ERCP) performed postoperatively. The patient was treated with a novel strategy by combining advanced endoscopic and laparoscopic techniques in three stages as follows: Stage 1 (initial presentation): endoscopic sphincterotomy with common bile duct stent placement; Stage 2 (6 weeks after Stage 1): laparoscopic ultrasonography to locate the remnant cystic duct calculi followed by laparoscopic retrieval of the calculi and intracorporeal closure of cystic duct stump; Stage 3 (6 weeks after Stage 2): endoscopic removal of common bile duct stent along with performance of completion endoscopic retrograde cholangiogram. In addition, we have performed an extensive review of the various endoscopic and laparoscopic management techniques described in the literature for the treatment of postcholecystectomy syndrome occurring from retained cystic duct stones. PMID:27047698

  19. Advanced Strategy Guideline. Air Distribution Basics and Duct Design

    SciTech Connect

    Burdick, Arlan

    2011-12-01

    This report discusses considerations for designing an air distribution system for an energy efficient house that requires less air volume to condition the space. Considering the HVAC system early in the design process will allow adequate space for equipment and ductwork and can result in cost savings.

  20. Heat Transfer in a Superelliptic Transition Duct

    NASA Technical Reports Server (NTRS)

    Poinsatte, Philip; Thurman, Douglas; Hippensteele, Steven

    2008-01-01

    Local heat transfer measurements were experimentally mapped using a transient liquid-crystal heat transfer technique on the surface of a circular-to-rectangular transition duct. The transition duct had a length-to-diameter ratio of 1.5 and an exit-plane aspect ratio of 3. The crosssectional geometry was defined by the equation of a superellipse. The cross-sectional area was the same at the inlet and exit but varied up to 15 percent higher through the transition. The duct was preheated to a uniform temperature (nominally 64 C) before allowing room temperature air to be suddenly drawn through it. As the surface cooled, the resulting isothermal contours on the duct surface were revealed using a surface coating of thermochromic liquid crystals that display distinctive colors at particular temperatures. A video record was made of the surface temperature and time data for all points on the duct surfaces during each test. Using this surface temperature-time data together with the temperature of the air flowing through the model and the initial temperature of the model wall, the heat transfer coefficient was calculated by employing the classic one-dimensional, semi-infinite wall heat transfer conduction model. Test results are reported for inlet diameter-based Reynolds numbers ranging from 0.4x106 to 2.4x106 and two grid-generated freestream turbulence intensities of about 1 percent, which is typical of wind tunnels, and up to 16 percent, which may be more typical of real engine conditions.

  1. Reducing Uncertainty for the DeltaQ Duct Leakage Test

    SciTech Connect

    Walker, Iain S.; Sherman, Max H.; Dickerhoff, Darryl J.

    2004-05-01

    The thermal distribution system couples the HVAC components to the building envelope, and shares many properties of the buildings envelope including moisture, conduction and most especially air leakage performance. Duct leakage has a strong influence on air flow rates through building envelopes (usually resulting in much greater flows than those due to natural infiltration) because unbalanced duct air flows and leaks result in building pressurization and depressurization. As a tool to estimate this effect, the DeltaQ duct leakage test has been developed over the past several years as an improvement to existing duct pressurization tests. It focuses on measuring the air leakage flows to outside at operating conditions that are required for envelope infiltration impacts and energy loss calculations for duct systems. The DeltaQ test builds on the standard envelope tightness blower door measurement techniques by repeating the tests with the system air handler off and on. The DeltaQ test requires several assumptions to be made about duct leakage and its interaction with the duct system and building envelope in order to convert the blower door results into duct leakage at system operating conditions. This study examined improvements to the DeltaQ test that account for some of these assumptions using a duct system and building envelope in a test laboratory. The laboratory measurements used a purpose-built test chamber coupled to a duct system typical of forced air systems in US homes. Special duct leaks with controlled air-flow were designed and installed into an airtight duct system. This test apparatus allowed the systematic variation of the duct and envelope leakage and accurate measurement of the duct leakage flows for comparison to DeltaQ test results. This paper will discuss the laboratory test apparatus design, construction and operation, the various analysis techniques applied to the calculation procedure and present estimates of uncertainty in measured duct

  2. Experimental testing and computational modeling of flat oval duct deflection

    SciTech Connect

    Smolinski, P.J.; Palmer, G.S.

    1998-10-01

    The deflection characteristics of spiral seam flat oval HVAC duct are examined in this study, and the effects of duct size, wall thickness, and the size spacing, and type of external reinforcement on the duct deformation are investigated. A duct test setup and a deflection measurement frame were developed for measuring the deformation of flat oval duct, and experimental testing was performed on a variety of duct configurations to measure the duct deflections at various positive and negative internal pressures. Finite element computer models of the ducts were developed to predict the deflections. The correlation between the predictions of the computer model and the data from the experimental testing is highly variable with differences ranging from a few percent to several hundred percent. In general, it was found that there was closer agreement between the finite element results and the experimental measurements for smaller duct and at locations of type 2 external reinforcements. This may be due to the fact that the finite element model assumed the idealized flat oval shape and this shape was better matched by smaller ducts and near the external reinforcement. It was also found that in some cases, unreinforced duct could achieve higher pressures than type 1 reinforced duct before exceeding the deflection limits. Sources of error include the uneven surface of the mastic in the measurement of the duct joint deflection and the variance of the actual duct shape from the idealized shape used in the finite element model. This study did not examine the variability of the experimental results due to differences in duct shape or manufacture.

  3. Performance Study and CFD Predictions of a Ducted Fan System

    NASA Technical Reports Server (NTRS)

    Abrego, Anita I.; Chang, I-Chung; Bulaga, Robert W.; Rutkowski, Michael (Technical Monitor)

    2002-01-01

    An experimental investigation was completed in the NASA Ames 7 by 10-Foot Wind Tunnel to study the performance characteristics of a ducted fan. The goal of this effort is to study the effect of ducted fan geometry and utilize Computational Fluid Dynamics (CFD) analysis to provide a baseline for correlation. A 38-inch diameter, 10-inch chord duct with a five-bladed fixed-pitch fan was tested. Duct performance data were obtained in hover, vertical climb, and forward flight test conditions. This paper will present a description of the test, duct performance results and correlation with CFD predictions.

  4. Transition duct with divided upstream and downstream portions

    SciTech Connect

    McMahan, Kevin Weston; LeBegue, Jeffrey Scott; Maldonado, Jaime Javier; Dillard, Daniel Jackson; Flanagan, James Scott

    2015-07-14

    Turbine systems are provided. In one embodiment, a turbine system includes a transition duct comprising an inlet, an outlet, and a duct passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The duct passage includes an upstream portion extending from the inlet and a downstream portion extending from the outlet. The turbine system further includes a rib extending from an outer surface of the duct passage, the rib dividing the upstream portion and the downstream portion.

  5. Particle deposition in ventilation ducts: Connectors, bends anddeveloping flow

    SciTech Connect

    Sippola, Mark R.; Nazaroff, William W.

    2004-03-01

    In ventilation duct flow the turbulent flow profile is commonly disturbed or not fully developed and these conditions are likely to influence particle deposition to duct surfaces. Particle deposition rates at eight S-connectors, in two 90{sup o} duct bends and in two ducts where the turbulent flow profile was not fully developed were measured in a laboratory duct system with both galvanized steel and internally insulated ducts with hydraulic diameters of 15.2 cm. In the steel duct system, experiments with nominal particle diameters of 1, 3, 5, 9 and 16 {micro}m were conducted at each of three nominal air speeds: 2.2, 5.3 and 9.0 m/s. In the insulated duct system, deposition of particles with nominal diameters of 1, 3, 5, 8 and 13 {micro}m was measured at nominal air speeds of 2.2, 5.3 and 8.8 m/s. Fluorescent techniques were used to directly measure the deposition velocities of monodisperse fluorescent particles to duct surfaces. Deposition at S-connectors, in bends and in straight ducts with developing turbulence was often greater than deposition in straight ducts with fully developed turbulence for equal particle sizes, air speeds and duct surface orientations. Deposition rates at all locations were found to increase with an increase in particle size or air speed. High deposition rates at S-connectors resulted from impaction and these rates were nearly independent of the orientation of the S-connector. Deposition rates in the two 90{sup o} bends differed by more than an order of magnitude in some cases, probably because of the difference in turbulence conditions at the bend inlets. In straight steel ducts where the turbulent flow profile was developing, the deposition enhancement relative to fully developed turbulence generally increased with air speed and decreased with downstream distance from the duct inlet. This enhancement was greater at the duct ceiling and wall than at the duct floor. In insulated ducts, deposition enhancement was less pronounced overall

  6. Acoustic radiation from lined, unflanged ducts: Acoustic source distribution program

    NASA Technical Reports Server (NTRS)

    Beckemeyer, R. J.; Sawdy, D. T.

    1971-01-01

    An acoustic radiation analysis was developed to predict the far-field characteristics of fan noise radiated from an acoustically lined unflanged duct. This analysis is comprised of three modular digital computer programs which together provide a capability of accounting for the impedance mismatch at the duct exit plane. Admissible duct configurations include circular or annular, with or without an extended centerbody. This variation in duct configurations provides a capability of modeling inlet and fan duct noise radiation. The computer programs are described in detail.

  7. Endoscopic Ultrasound (EUS)-Guided Pancreatic Duct Drainage: The Basics of When and How to Perform EUS-Guided Pancreatic Duct Interventions

    PubMed Central

    Chapman, Christopher G.; Waxman, Irving; Siddiqui, Uzma D.

    2016-01-01

    Despite the advances in endoscopy, endoscopic ultrasound-guided pancreatic duct drainage (EUS-PDD) remains a technically challenging procedure. Technical success rates are greater than 70%; however, the average rate of adverse events is nearly 20%, which increases to 55% when stent migration is included. Until recently, a significant difficulty with this technique was the absence of dedicated devices. Proper patient selection is of utmost importance, and EUS-PDD should be reserved for patients who have failed endoscopic retrograde pancreatography. Furthermore, EUS-PDD must be performed by experienced endoscopists who are familiar with the technique. The most common indications include chronic pancreatitis induced strictures and stones, disconnected pancreatic ducts, inaccessible ampulla, and post-surgical altered anatomy. This manuscript will review the accessories used, techniques employed, and published literature reporting outcomes as well as adverse events regarding EUS-PDD. PMID:27012290

  8. Endoscopic Ultrasound (EUS)-Guided Pancreatic Duct Drainage: The Basics of When and How to Perform EUS-Guided Pancreatic Duct Interventions.

    PubMed

    Chapman, Christopher G; Waxman, Irving; Siddiqui, Uzma D

    2016-03-01

    Despite the advances in endoscopy, endoscopic ultrasound-guided pancreatic duct drainage (EUS-PDD) remains a technically challenging procedure. Technical success rates are greater than 70%; however, the average rate of adverse events is nearly 20%, which increases to 55% when stent migration is included. Until recently, a significant difficulty with this technique was the absence of dedicated devices. Proper patient selection is of utmost importance, and EUS-PDD should be reserved for patients who have failed endoscopic retrograde pancreatography. Furthermore, EUS-PDD must be performed by experienced endoscopists who are familiar with the technique. The most common indications include chronic pancreatitis induced strictures and stones, disconnected pancreatic ducts, inaccessible ampulla, and post-surgical altered anatomy. This manuscript will review the accessories used, techniques employed, and published literature reporting outcomes as well as adverse events regarding EUS-PDD. PMID:27012290

  9. The Reduction of Ducted Fan Engine Noise Via a Boundary Integral Equation Method

    NASA Technical Reports Server (NTRS)

    Tweed, John

    2000-01-01

    Engineering studies for reducing ducted fan engine noise were conducted using the noise prediction code TBIEM3D. To conduct parametric noise reduction calculations, it was necessary to advance certain theoretical and computational aspects of the boundary integral equation method (BIEM) described in and implemented in TBIEM3D. Also, enhancements and upgrades to TBIEM3D were made for facilitating the code's use in this research and by the aeroacoustics engineering community.

  10. Coupled parametric design of flow control and duct shape

    NASA Technical Reports Server (NTRS)

    Florea, Razvan (Inventor); Bertuccioli, Luca (Inventor)

    2009-01-01

    A method for designing gas turbine engine components using a coupled parametric analysis of part geometry and flow control is disclosed. Included are the steps of parametrically defining the geometry of the duct wall shape, parametrically defining one or more flow control actuators in the duct wall, measuring a plurality of performance parameters or metrics (e.g., flow characteristics) of the duct and comparing the results of the measurement with desired or target parameters, and selecting the optimal duct geometry and flow control for at least a portion of the duct, the selection process including evaluating the plurality of performance metrics in a pareto analysis. The use of this method in the design of inter-turbine transition ducts, serpentine ducts, inlets, diffusers, and similar components provides a design which reduces pressure losses and flow profile distortions.

  11. Curved Duct Noise Prediction Using the Fast Scattering Code

    NASA Technical Reports Server (NTRS)

    Dunn, M. H.; Tinetti, Ana F.; Farassat, F.

    2007-01-01

    Results of a study to validate the Fast Scattering Code (FSC) as a duct noise predictor, including the effects of curvature, finite impedance on the walls, and uniform background flow, are presented in this paper. Infinite duct theory was used to generate the modal content of the sound propagating within the duct. Liner effects were incorporated via a sound absorbing boundary condition on the scattering surfaces. Simulations for a rectangular duct of constant cross-sectional area have been compared to analytical solutions and experimental data. Comparisons with analytical results indicate that the code can properly calculate a given dominant mode for hardwall surfaces. Simulated acoustic behavior in the presence of lined walls (using hardwall duct modes as incident sound) is consistent with expected trends. Duct curvature was found to enhance weaker modes and reduce pressure amplitude. Agreement between simulated and experimental results for a straight duct with hard walls (no flow) was excellent.

  12. Advanced ramjet concepts program

    NASA Technical Reports Server (NTRS)

    Leingang, J. L.

    1992-01-01

    Uniquely advantageous features, on both the performance and weight sides of the ledger, can be achieved through synergistic design integration of airbreathing and rocket technologies in the development of advanced orbital space transport propulsion systems of the combined cycle type. In the context of well understood advanced airbreathing and liquid rocket propulsion principles and practices, this precept of synergism is advanced mainly through six rather specific examples. These range from the detailed component level to the overall vehicle system level as follows: using jet compression; achieving a high area ratio rocket nozzle; ameliorating gas generator cycle rocket system deficiencies; using the in-duct special rocket thrust chamber assembly as the principal scramjet fuel injection operation; using the unstowed, covered fan as a duct closure for effecting high area ratio rocket mode operation; and creating a unique airbreathing rocket system via the onboard, cryogenic hydrogen induced air liquefaction process.

  13. SNM holdup assessment of Los Alamos exhaust ducts. Final report

    SciTech Connect

    Marshall, R.S.

    1994-02-01

    Fissile material holdup in glovebox and fume hood exhaust ducting has been quantified for all Los Alamos duct systems. Gamma-based, nondestructive measurements were used to quantify holdup. The measurements were performed during three measurement campaigns. The first campaign, Phase I, provided foot-by-foot, semiquantitative measurement data on all ducting. These data were used to identify ducting that required more accurate (quantitative) measurement. Of the 280 duct systems receiving Phase I measurements, 262 indicated less than 50 g of fissile holdup and 19 indicated fissile holdup of 50 or more grams. Seven duct systems were measured in a second campaign, called Series 1, Phase II. Holdup estimates on these ducts ranged from 421 g of {sup 235}U in a duct servicing a shut-down uranium-machining facility to 39 g of {sup 239}Pu in a duct servicing an active plutonium-processing facility. Measurements performed in the second campaign proved excessively laborious, so a third campaign was initiated that used more efficient instrumentation at some sacrifice in measurement quality. Holdup estimates for the 12 duct systems measured during this third campaign ranged from 70 g of {sup 235}U in a duct servicing analytical laboratories to 1 g of {sup 235}U and 1 g of {sup 239}Pu in a duct carrying exhaust air to a remote filter building. These quantitative holdup estimates support the conclusion made at the completion of the Phase I measurements that only ducts servicing shut-down uranium operations contain about 400 g of fissile holdup. No ventilation ducts at Los Alamos contain sufficient fissile material holdup to present a criticality safety concern.

  14. Periodic Time-Domain Nonlocal Nonreflecting Boundary Conditions for Duct Acoustics

    NASA Technical Reports Server (NTRS)

    Watson, Willie R.; Zorumski, William E.

    1996-01-01

    Periodic time-domain boundary conditions are formulated for direct numerical simulation of acoustic waves in ducts without flow. Well-developed frequency-domain boundary conditions are transformed into the time domain. The formulation is presented here in one space dimension and time; however, this formulation has an advantage in that its extension to variable-area, higher dimensional, and acoustically treated ducts is rigorous and straightforward. The boundary condition simulates a nonreflecting wave field in an infinite uniform duct and is implemented by impulse-response operators that are applied at the boundary of the computational domain. These operators are generated by convolution integrals of the corresponding frequency-domain operators. The acoustic solution is obtained by advancing the Euler equations to a periodic state with the MacCormack scheme. The MacCormack scheme utilizes the boundary condition to limit the computational space and preserve the radiation boundary condition. The success of the boundary condition is attributed to the fact that it is nonreflecting to periodic acoustic waves. In addition, transient waves can pass rapidly out of the solution domain. The boundary condition is tested for a pure tone and a multitone source in a linear setting. The effects of various initial conditions are assessed. Computational solutions with the boundary condition are consistent with the known solutions for nonreflecting wave fields in an infinite uniform duct.

  15. Optimization of the mechanical performance of a two-duct semicircular duct system--part 2: excitation of endolymph movements.

    PubMed

    Muller, M; Verhagen, J H G

    2002-06-21

    The endolymph flow inside the semicircular ducts is analytically investigated by considering a system of two hydrodynamically interconnected ducts. Rotation of this system adds an amount of motion (momentum) to parts of it. This results in an endolymph flow in generally all vestibular parts. The "external impulses" are the impulses which emerge by rotation of exclusively a particular vestibular part. The real impulses can be calculated from a set of equations which contain the external impulses. Analytical expressions are derived for the initial velocities in the ducts and for the maximum endolymph displacements. These formulae contain the external impulses and the ratios of: (1) the radii of crus commune and ducts (gamma), (2) the lengths of crus commune and ducts (lambda). It was proven that an interconnected system composed of two ducts, and also a system composed of two such semicircular duct systems, behaves as a pure rotation transducer (like a single duct does), also when it is rotated excentrically. Duct systems with polygonal and circular geometries were used to evaluate whether an optimal value of lambda would exist (gamma was already considered elsewhere). Optimum values of lambda in a range of about 0.10-0.52 were found. This rather wide range of values agrees with values from measurements. Optimization of an interconnected duct system appeared to be equal to optimization of a system composed of separate ducts. PMID:12151259

  16. Contrasting the efficiency of radiation belt losses caused by ducted and non-ducted whistler mode waves from manmade transmitters

    NASA Astrophysics Data System (ADS)

    Rodger, C. J.; Carson, Bonar; Cummer, Steven A.; Gamble, R. J.; Clilverd, Mark; Sauvaud, Jean-Andre; Parrot, Michel; Green, Janet

    Electromagnetic waves in the VLF range generated at or near the Earth's surface can penetrate the ionosphere and propagate through the plasmasphere. It has long been recognized that whistler-mode waves can be trapped in localized field-aligned enhancements in plasmaspheric ionization density termed "whistler ducts", which guide the waves from one hemisphere to the other. For the non-guided cases, the whistler mode waves are said to be "nonducted". The nature of wave-particle interactions are affected by the wave being ducted or non-ducted through influence on the wave-normal angles. In the field-aligned ducted case, the dominant resonance possible is first-order cyclotron, whereas non-ducted interactions open up a much wider range of energies through equatorial and off-equatorial gyro-resonance. Thus the significance of these VLF waves as drivers of radiation belt losses is strongly influenced by whether these waves are dominantly ducted or non-ducted. At this point there is conflicting information in the literature as to whether the most significant loss processes are driven by ducted or non-ducted waves. In this study we use loss cone observations from instruments onboard the DEMETER and POES low-altitude satellites to focus on losses driven by powerful VLF communications transmitters. We wish to better characterise the losses previously reported and explained through interactions with ducted VLF transmissions. We also plan to examine losses into the atmosphere driven by non-ducted transmissions.

  17. Theoretical analysis of HVAC duct hanger systems

    NASA Technical Reports Server (NTRS)

    Miller, R. D.

    1987-01-01

    Several methods are presented which, together, may be used in the analysis of duct hanger systems over a wide range of frequencies. The finite element method (FEM) and component mode synthesis (CMS) method are used for low- to mid-frequency range computations and have been shown to yield reasonably close results. The statistical energy analysis (SEA) method yields predictions which agree with the CMS results for the 800 to 1000 Hz range provided that a sufficient number of modes participate. The CMS approach has been shown to yield valuable insight into the mid-frequency range of the analysis. It has been demonstrated that it is possible to conduct an analysis of a duct/hanger system in a cost-effective way for a wide frequency range, using several methods which overlap for several frequency bands.

  18. Porokeratotic Eccrine Ostial and Dermal Duct Nevus

    PubMed Central

    Naraghi, Mona Masoumeh; Goodarzi, Azadeh

    2013-01-01

    PEODDN is a rare benign cutaneous disorder that clinically resembles comedo nevus but favors the palms and soles, where pilosebaceous follicles are absent. Widespread involvement along Blaschko's lines can also occur. It is a disorder of keratinization involving the intraepidermal eccrine duct (acrosyringium) and is characterized by eccrine hamartoma and cornoid lamellation in pathology. The patient is a 29-year-old man with an 8-year history of pruritic skin lesions on his right lateral ankle. In the pathologic examination, multiple small epidermal invagination with overlying parakeratotic cornoid lamellation, loss of granular layer, and few dyskeratotic cells at the base of epidermal invagination are revealed. After clinic-pathologic correlation, the diagnosis of porokeratotic eccrine ostial and dermal duct nevus (PEODDN) was made. Late-onset and rare clinical presentation as pruritic lesion are the characteristic features that make this patient an extraordinary presentation of PEODDN. PMID:24307955

  19. Sea echo in tropospheric ducting environments

    NASA Astrophysics Data System (ADS)

    Pappert, R. A.; Paulus, R. A.; Tappert, F. D.

    1992-04-01

    Path loss formulas for sea surface backscatter are developed for horizontally stratified tropospheric ducting environments. First-order Bragg backscatter results coupled with ray and waveguide formalism serve as the basis for the development. Two features of composite model formalism, namely shadowing and tilting of the surface normal in the plane of incidence, are included in the development. Though developed for hh polarization, conventional composite model modifications for vertical polarization and depolarization can be incorporated into the echo models. Comparisons are made with previously generated parabolic equation results and with empirical model results generated by Engineers Refractive Effects Prediction System. These comparisons are for a frequency of 9.6 GHz for the standard atmosphere and for 14- and 28-m evaporation ducts. Results apply to wind speeds of 10, 20, 30, and 40 knots (about 5, 10, 15, and 20 m/s).

  20. Evaporation duct assessment from meteorological buoys

    NASA Astrophysics Data System (ADS)

    Hitney, Herbert V.

    2002-07-01

    The evaporation duct over the sea is usually assessed using bulk meteorological measurements. This paper investigates the utility of meteorological buoys as a source for these bulk measurements and compares evaporation duct assessments using two buoys in southern California waters separated by 128 km. A simple radio propagation experiment at 2.4 GHz between one of the buoys and the coast on an 18.2 km path is described. Observed propagation loss from this experiment is compared to modeled loss based on the meteorological measurements at each buoy. The purpose of this paper is to investigate radio propagation effects using established and accepted methods already described in the literature. Accordingly, no discussion of atmospheric surface layer meteorology affecting radio propagation is given.

  1. Ontogeny of the nasopalatine duct in primates.

    PubMed

    Shimp, Kristin L; Bhatnagar, Kunwar P; Bonar, Christopher J; Smith, Timothy D

    2003-09-01

    Ecological explanations have been put forward to account for the precocious or delayed development of patency in ducts leading to the vomeronasal organ (VNO) in certain mammals. Perinatal function may be related, in part, to the patency or fusion of the vomeronasal and nasopalatine (NPD) ducts. However, few studies have focused on NPD development in primates, which generally have a prolonged period of dependence during infancy. In this study we examined 24 prenatal primates and 13 neonatal primates, and a comparative sample of fetal mice and insectivores. In embryonic and early fetal Microcebus murinus, the NPD was completely fused, whereas in fetuses of later stages the duct was partially fused or completely patent. M. myoxinus of all stages demonstrated some degree of NPD fusion. In all other prenatal primates, the NPD was fused to some extent. Four prenatal insectivores (Tenrec ecaudatus) showed some degree of NPD fusion. In Mus musculus at 19 days gestation, the NPD was patent, although the anatomically separate VNO duct was fused. T. ecaudatus and most of the neonatal primates revealed complete NPD patency. An exception was Saguinus geoffroyi, which exhibited fusion of the NPD near the VNO opening. These observations may relate to differences in perinatal VNO function. The differences noted in our study suggest that M. murinus and M. myoxinus may differ in perinatal VNO functionality and perhaps in related behavior. Observations of neonatal primates suggest that NPD patency may be relatively common at birth and could serve other purposes in addition to being an access route for VNO stimuli. PMID:12923897

  2. Acoustic-Liner Admittance in a Duct

    NASA Technical Reports Server (NTRS)

    Watson, W. R.

    1986-01-01

    Method calculates admittance from easily obtainable values. New method for calculating acoustic-liner admittance in rectangular duct with grazing flow based on finite-element discretization of acoustic field and reposing of unknown admittance value as linear eigenvalue problem on admittance value. Problem solved by Gaussian elimination. Unlike existing methods, present method extendable to mean flows with two-dimensional boundary layers as well. In presence of shear, results of method compared well with results of Runge-Kutta integration technique.

  3. Zero leakage separable and semipermanent ducting joints

    NASA Technical Reports Server (NTRS)

    Mischel, H. T.

    1973-01-01

    A study program has been conducted to explore new methods of achieving zero leakage, separable and semipermanent, ducting joints for space flight vehicles. The study consisted of a search of literature of existing zero leakage methods, the generation of concepts of new methods of achieving the desired zero leakage criteria and the development of detailed analysis and design of a selected concept. Other techniques of leak detection were explored with a view toward improving this area.

  4. Laminar heat transfer in annular sector ducts

    SciTech Connect

    Soliman, H.M. )

    1987-02-01

    The continuing interest in compact heat exchangeers has created the need for friction factor and Nusselt number data for different passage shapes. It has long been recognized that circular tube results are generally not applicable to noncircular passages even when the hydraulic diameter is used as the characteristic dimension. Hence, design data should be generated for each passage individually, and a good source of such information is Shah and London. One duct geometry for which complete design information does not appear to be available in the open literature is that of annular sector ducts. Such configuration is encountered in multipassage internally finned tubes and many other compact het exchanger applications. The fluid flow problem for this configuration has been solved by Sparrow et al., and more recently by Niida. However, to the beest of the author's knowledge, the heat transfer results are not available yet. The purpose of this note is to summarize the analysis and results of fluid flow and heat transfer in annular sector ducts.

  5. Autoignitions and detonations in engines and ducts.

    PubMed

    Bradley, Derek

    2012-02-13

    The origins of autoignition at hot spots are analysed and the pressure pulses that arise from them are related to knock in gasoline engines and to developing detonations in ducts. In controlled autoignition engines, autoignition is benign with little knock. There are several modes of autoignition and the existence of an operational peninsula, within which detonations can develop at a hot spot, helps to explain the performance of various engines. Earlier studies by Urtiew and Oppenheim of the development of autoignitions and detonations ahead of a deflagration in ducts are interpreted further, using a simple one-dimensional theory of the generation of shock waves ahead of a turbulent flame. The theory is able to indicate entry into the domain of autoignition in an 'explosion in the explosion'. Importantly, it shows the influence of the turbulent burning velocity, and particularly its maximum attainable value, upon autoignition. This value is governed by localized flame extinctions for both turbulent and laminar flames. The theory cannot show any details of the transition to a detonation, but regimes of eventually stable or unstable detonations can be identified on the operational peninsula. Both regimes exhibit transverse waves, triple points and a cellular structure. In the case of unstable detonations, transverse waves are essential to the continuing propagation. For hazard assessment, more needs to be known about the survival, or otherwise, of detonations that emerge from a duct into the same mixture at atmospheric pressure. PMID:22213665

  6. The transient response above an evaporation duct

    NASA Astrophysics Data System (ADS)

    Abo-Seliem, Adel A. S.

    1998-11-01

    The transient electromagnetic field generated by a vertical electric dipole above an evaporation duct is investigated theoretically. The evaporation duct model used is that previously described by Kahan and Eckart. A vertical electric dipole, above the surface layer, is taken as the source of the electromagnetic field. We determine the electrical field strength exactly at some fixed point above the duct layer, having chosen a certain polarization of the primary source whose moment is allowed to vary arbitrarily with time. A series expansion with respect to the images of the primary source permits us to apply the method first reported by Cagniard and later extended by de Hoop and Frankena to the case where the source is positioned in a medium of lesser permittivity. Hence, we can give a physically intuitive description of the polarization dependence of the time history of the electrical field strength. The distinction of different cases where the distances between the receiving and transmitting ends are greater or lesser than the total reflection distance is studied. The electrical field strength is evaluated for different excitation functions at some fixed but arbitrary positions of the point of observation in the half-space.

  7. Radiative interactions in laminar duct flows

    NASA Technical Reports Server (NTRS)

    Trivedi, P. A.; Tiwari, S. N.

    1990-01-01

    Analyses and numerical procedures are presented for infrared radiative energy transfer in gases when other modes of energy transfer occur simultaneously. Two types of geometries are considered, a parallel plate duct and a circular duct. Fully developed laminar incompressible flows of absorbing-emitting species in black surfaced ducts are considered under the conditions of uniform wall heat flux. The participating species considered are OH, CO, CO2, and H2O. Nongray as well as gray formulations are developed for both geometries. Appropriate limiting solutions of the governing equations are obtained and conduction-radiation interaction parameters are evaluated. Tien and Lowder's wide band model correlation was used in nongray formulation. Numerical procedures are presented to solve the integro-differential equations for both geometries. The range of physical variables considered are 300 to 2000 K for temperature, 0.1 to 100.0 atm for pressure, and 0.1 to 100 cm spacings between plates/radius of the tube. An extensive parametric study based on nongray formulation is presented. Results obtained for different flow conditions indicate that the radiative interactions can be quite significant in fully developed incompressible flows.

  8. Pronephric duct extension in amphibian embryos: migration and other mechanisms.

    PubMed

    Drawbridge, Julie; Meighan, Christopher M; Lumpkins, Rebecca; Kite, Mary E

    2003-01-01

    Initiation of excretory system development in all vertebrates requires (1) delamination of the pronephric and pronephric duct rudiments from intermediate mesoderm at the ventral border of anterior somites, and (2) extension of the pronephric duct to the cloaca. Pronephric duct extension is the central event in nephric system development; the pronephric duct differentiates into the tubule that carries nephric filtrate out of the body and induces terminal differentiation of adult kidneys. Early studies concluded that pronephric ducts formed by means of in situ segregation of pronephric duct tissue from lateral mesoderm ventral to the forming somites; more recent studies highlight caudal migration of the pronephric duct as the major morphogenetic mechanism. The purpose of this review is to provide the historical background on studies of the mechanisms of amphibian pronephric duct extension, to review evidence showing that different amphibians perform pronephric duct morphogenesis in different ways, and to suggest future studies that may help illuminate the molecular basis of the mechanisms that have evolved in amphibians to extend the pronephric duct to the cloaca. PMID:12508219

  9. Accessory Pancreatic Duct Patterns and Their Clinical Implications

    PubMed Central

    Prasanna, Lokadolalu Chandracharya; Rajagopal, KV; Thomas, Huban R

    2015-01-01

    Context and Objective: Accessory pancreatic duct (APD) designed to reduce the pressure of major pancreatic duct by forming a secondary drainage channel. Few studies have mentioned the variant types of accessory ducts and their mode of formation, some of these have a clear clinical significance. Present study is aimed to evaluate the possible variations in the APD and its terminations. Materials and Methods: Forty formalin fixed adult human pancreas with duodenum in situ specimens were studied by injecting 1% aqueous eosin, followed by piece meal dissection of the head of the pancreas from posterior surface. Formation, tributaries, relations, and the termination of the accessory pancreatic duct were noted and photographed. Results: Accessory ducts revealed 50% belonged to long type, 22.5% were of short and ansa pancreatica type each, and embryonic type of duct pattern was seen in 5% specimens. 75% of long type ducts showed positive patency with eosin dye, followed by ansa type (44.4%), and least patency was found in short type (22.2%). With regard to the patency of the accessory pancreatic ducts towards their termination, we found 52.5% of the accessory ducts and 5% of the embryonic type pancreatic ducts were patent and in 42.5% of the specimen the ducts were obliterated. In 85% of specimens the minor duodenal papillae was anterosuperior to the major papilla and superior to the major papillae in 10% of the cases, and in 5% minor papillae was absent. The average distance between the two papillae was 2.35 cm. Conclusion: The knowledge of the complex anatomical relations of the gland with its duct, duodenum and bile ducts are essential for the surgeons and sinologists to plan and perform both the diagnostic as well as therapeutic procedures effectively. PMID:25954609

  10. Optimizing Electrospray Interfaces Using Slowly Diverging Conical Duct (ConDuct) Electrodes

    PubMed Central

    Krutchinsky, Andrew N.; Padovan, Júlio C.; Cohen, Herbert; Chait, Brian T.

    2015-01-01

    We demonstrate that the efficiency of ion transmission from atmosphere to vacuum through stainless steel electrodes that contain slowly divergent conical duct (ConDuct) channels can be close to 100%. Here, we explore the properties of 2.5 cm long electrodes with angles of divergence of 0°, 1°, 2°, 3°, 5°, 8°, 13°, and 21°, respectively. The ion transmission efficiency was observed to jump from 10–20% for the 0° (straight) channels to 90–95% for channels with an angle of divergence as small as 1°. Furthermore, the 2–3° ConDuct electrodes produced extraordinarily low divergence ion beams that propagated in a laser-like fashion over long distances in vacuum. To take advantage of these newly discovered properties, we constructed a novel atmosphere-to-vacuum ion interface utilizing a 2° ConDuct as an inlet electrode and compared its ion transmission efficiency with that of the interface used in the commercial (Thermo) Velos Orbitrap and Q Exactive mass spectrometers. We observed that the ConDuct interface transmitted up to 17 times more ions than the commercial reference interface and also yielded improved signal-to-noise mass spectra of peptides. We infer from these results that the performance of many current atmosphere-tovacuum interfaces utilizing metal capillaries can be substantially improved by replacing them with 1° or 2° metal ConDuct electrodes, which should preserve the convenience of supplying ion desolvation energy by heating the electrode while greatly increasing the efficiency of ion transmission into the mass spectrometer. PMID:25667060

  11. Scaleup tests and supporting research for the development of duct injection technology: Topical report No. 3, Task 3. 2: Scale-up testing; Topical report No. 4, Task 3. 3: Advanced configurations; Topical report No. 5, Task 3. 4: Process controls; Topical report No. 6, Task 3. 5: Failure modes; Task 3. 6: Waste characterization, Duct Injection Test Facility, Muskingum River Power Plant, Beverly, Ohio

    SciTech Connect

    Felix, L.G.; Gooch, J.P.; Merritt, R.L. ); Klett, M.G.; Demian, A.G.; Hunt, J.E. )

    1992-08-01

    This document is the third interim report on tests that were conducted at the Duct Injection Test Facility (DITF) operated for the Department of Energy at Unit 5 of the Ohio Power Company's Muskingum River station in Beverly, Ohio. At the DITF dry calcium hydroxide (Ca(OH)2), an aqueous slurry of Ca(OH)[sub 2] (prepared by slaking quicklime), or a mixture of one of these sorbents with waste ash from earlier tests was injected into a slipstream of flue gas from the Unit 5 boiler to achieve partial removal of SO[sub 2] in the flue gas. Up to 50,000 acfm of flue gas was taken from the inlet to the Unit 5 electrostatic precipitator (ESP) for these tests. Water was injected separately with the dry sorbent or as part of the slurry to cool the flue gas and increase the water vapor content of the flue gas. The addition of water, either as a separate spray or in the slurry makes the reaction between the sorbent and the SO[sub 2] more complete; the presumption is that water is effective in the liquid state when it can physically wet the sorbent particles, and not especially effective in the vapor state. Higher values of calcium utilization were obtained with slurry injection than with dry sorbent injection and humidification. Slurries made from reagent slaked lime, mixtures of reagent slaked lime and recycle ash, and from recycle ash alone were injected through the same nozzles used for humidification. The focus of most of these tests was on the constant addition of recycle ash to reduce the amount of slaked lime required for SO[sub 2] removal (for best economics). Testing was continued until the amount of Ca(OH)[sub 2] in the recycle ash equaled that predicted for equilibrium Two test cases were evaluated: a low Ca/S ratio (1.0 reagent, 44[degrees]/F approach) for 50% SO[sub 2] removal and a high Ca/S ratio (1.7 reagent, 24[degrees]F approach) for 88% SO[sub 2] removal.

  12. Scaleup tests and supporting research for the development of duct injection technology: Topical report No. 3, Task 3.2: Scale-up testing; Topical report No. 4, Task 3.3: Advanced configurations; Topical report No. 5, Task 3.4: Process controls; Topical report No. 6, Task 3.5: Failure modes; Task 3.6: Waste characterization, Duct Injection Test Facility, Muskingum River Power Plant, Beverly, Ohio

    SciTech Connect

    Felix, L.G.; Gooch, J.P.; Merritt, R.L.; Klett, M.G.; Demian, A.G.; Hunt, J.E.

    1992-08-01

    This document is the third interim report on tests that were conducted at the Duct Injection Test Facility (DITF) operated for the Department of Energy at Unit 5 of the Ohio Power Company`s Muskingum River station in Beverly, Ohio. At the DITF dry calcium hydroxide (Ca(OH)2), an aqueous slurry of Ca(OH){sub 2} (prepared by slaking quicklime), or a mixture of one of these sorbents with waste ash from earlier tests was injected into a slipstream of flue gas from the Unit 5 boiler to achieve partial removal of SO{sub 2} in the flue gas. Up to 50,000 acfm of flue gas was taken from the inlet to the Unit 5 electrostatic precipitator (ESP) for these tests. Water was injected separately with the dry sorbent or as part of the slurry to cool the flue gas and increase the water vapor content of the flue gas. The addition of water, either as a separate spray or in the slurry makes the reaction between the sorbent and the SO{sub 2} more complete; the presumption is that water is effective in the liquid state when it can physically wet the sorbent particles, and not especially effective in the vapor state. Higher values of calcium utilization were obtained with slurry injection than with dry sorbent injection and humidification. Slurries made from reagent slaked lime, mixtures of reagent slaked lime and recycle ash, and from recycle ash alone were injected through the same nozzles used for humidification. The focus of most of these tests was on the constant addition of recycle ash to reduce the amount of slaked lime required for SO{sub 2} removal (for best economics). Testing was continued until the amount of Ca(OH){sub 2} in the recycle ash equaled that predicted for equilibrium Two test cases were evaluated: a low Ca/S ratio (1.0 reagent, 44{degrees}/F approach) for 50% SO{sub 2} removal and a high Ca/S ratio (1.7 reagent, 24{degrees}F approach) for 88% SO{sub 2} removal.

  13. Optimization of the mechanical performance of a two-duct semicircular duct system--part 3: the positioning of the ducts in the head.

    PubMed

    Muller, M; Verhagen, J H G

    2002-06-21

    In the majority of vertebrates, the horizontal duct of the vestibular system lies approximately in the yawing plane of the head. The positioning of the vertical ducts, however, is not in the pitch- and roll planes but the vertical ducts generally lie under an angle of about 30-45 degrees relative to the medial plane. Using the equations for a hydrodynamically interconnected two-duct system, optimal positions of the vertical and horizontal ducts in different vertebrate groups can be derived. It was stated that the mean response of the vertical ducts should be optimized. This leads to a symmetrical positioning of the vertical ducts with respect to the medial plane. In all observed vertebrate groups, a solution of mu =(pi-alpha)/2 is found (mu is the angle of the vertical ducts relative to the medial plane, alpha is the angle between the vertical duct planes). For alpha=90 degrees, this provides an equal sensitivity for pitch- and roll- movements. For alpha>90 degrees, a larger sensitivity for pitch movements is obtained, at the expense of a lower sensitivity for roll movements. It is argued that the angle alpha between the vertical ducts may vary from 90 to 120 degrees. In most vertebrates, the centre of mass is stabilized by e.g. fins, tri- or quadrupedal stability, a crawling body or upside-down resting positions (e.g. bats). Birds are generally biped, so in walking they are also rather sensitive to roll. These features are related to labyrinth positioning in the head. PMID:12151260

  14. The Advanced Noise Control Fan Baseline Measurements

    NASA Technical Reports Server (NTRS)

    McAllister, Joseph; Loew, Raymond A.; Lauer, Joel T.; Stuliff, Daniel L.

    2009-01-01

    The NASA Glenn Research Center s (NASA Glenn) Advanced Noise Control Fan (ANCF) was developed in the early 1990s to provide a convenient test bed to measure and understand fan-generated acoustics, duct propagation, and radiation to the farfield. As part of a complete upgrade, current baseline and acoustic measurements were documented. Extensive in-duct, farfield acoustic, and flow field measurements are reported. This is a follow-on paper to documenting the operating description of the ANCF.

  15. Patent vitellointestinal duct as paraumblical abcess: A rare presentation

    PubMed Central

    Rekhi, Harnam Singh; Mittal, Sushil; Singh, Gurtej; Rekhi, Balwinder Kaur; Dugg, Pankaj

    2015-01-01

    Introduction Umbilical and paraumblical abscess can occur in children with presenting complaint of discharge from umbilical region. However, patent vitello intestinal duct presenting as paraumblical abscess is rare phenomenon. Presentation of case One year old male child presented with complain of discharge from umbilical region since birth. Incision & drainage done twice thinking it to be paraumblical abscess. Discussion Vitellointestinal duct as abscess is rare presentation but it should be considered as a differential diagnosis of discharging umbilicus as management of abscess and patent duct are different. Conclusion Patent vitellointestinal duct can present as paraumbilical abscess, and it should be kept in differential diagnosis specifically in children. PMID:26301682

  16. BTS Fact Sheet: Improving the efficiency of your duct system

    SciTech Connect

    BNL

    1999-12-28

    The duct system, used in air heating and air cooling your home, is a collection of tubes that distributes the heated or cooled air to the various rooms. The duct system can have an important effect on health of the occupants through the distribution of indoor air pollution. Changes and repairs to a duct system should always be performed by a qualified professional. This brochure is meant to help you understand the problems that can affect the duct system and how you can save money, improve comfort, and protect against potential health hazards.

  17. Duct injection technology prototype development: Evaluation of engineering data

    SciTech Connect

    Not Available

    1990-07-01

    The objective of the Duct Injection Technology Prototype Development Project is to develop a sound design basis for applying duct injection technology as a post-combustion SO{sub 2}emissions control method to existing coal-fired power plants. The necessary engineering design and scale-up criteria will be developed for the commercialization of duct injection technology for the control of SO{sub 2} emissions from coal-fired boilers in the utility industry. The primary focus of the analyses summarized in this Topical Report is the review of the known technical and economic information associated with duct injection technology. (VC)

  18. Duct Remediation Program: Engineered access research and construction

    SciTech Connect

    Beckman, T.D.; Davis, M.M.; Karas, T.M.

    1992-11-01

    The Rocky Flats Plant, Duct Remediation mission concentrated on removing Plutonium Oxide from the process ductwork in the primary Plutonium processing facility. When possible, remediation took place from existing process gloveboxes. Fifteen locations were identified, however, that required accessing duct runs where no process gloveboxes existed. The building`s second floor utility areas had many locations where long, inaccessible duct runs were prevalent. Consequently, an extensive program for design, procurement and construction was initiated to contain and isolate ducts for penetration when existing glovebox sites were not present.

  19. Leaf seal for transition duct in turbine system

    SciTech Connect

    Flanagan, James Scott; LeBegue, Jeffrey Scott; McMahan, Kevin Weston; Dillard, Daniel Jackson; Pentecost, Ronnie Ray

    2013-06-11

    A turbine system is disclosed. In one embodiment, the turbine system includes a transition duct. The transition duct includes an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The transition duct further includes an interface member for interfacing with a turbine section. The turbine system further includes a leaf seal contacting the interface member to provide a seal between the interface member and the turbine section.

  20. Convolution seal for transition duct in turbine system

    SciTech Connect

    Flanagan, James Scott; LeBegue, Jeffrey Scott; McMahan, Kevin Weston; Dillard, Daniel Jackson; Pentecost, Ronnie Ray

    2015-03-10

    A turbine system is disclosed. In one embodiment, the turbine system includes a transition duct. The transition duct includes an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The transition duct further includes an interface member for interfacing with a turbine section. The turbine system further includes a convolution seal contacting the interface member to provide a seal between the interface member and the turbine section.

  1. Flexible metallic seal for transition duct in turbine system

    SciTech Connect

    Flanagan, James Scott; LeBegue, Jeffrey Scott; McMahan, Kevin Weston; Dillard, Daniel Jackson; Pentecost, Ronnie Ray

    2014-04-22

    A turbine system is disclosed. In one embodiment, the turbine system includes a transition duct. The transition duct includes an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The transition duct further includes an interface member for interfacing with a turbine section. The turbine system further includes a flexible metallic seal contacting the interface member to provide a seal between the interface member and the turbine section.

  2. Analysis of nephric duct specification in the avian embryo

    PubMed Central

    Attia, Lital; Yelin, Ronit; Schultheiss, Thomas M.

    2012-01-01

    Vertebrate kidney tissue exhibits variable morphology that in general increases in complexity when moving from anterior to posterior along the body axis. The nephric duct, a simple unbranched epithelial tube, is derived in the avian embryo from a rudiment located in the anterior intermediate mesoderm (IM) adjacent to somites 8 to 10. Using quail-chick chimeric embryos, the current study finds that competence to form nephric duct is fixed when IM precursor cells are still located in the primitive streak, significantly before the onset of duct differentiation. In the primitive streak, expression of the gene HoxB4 is associated with prospective duct IM, whereas expression of the more posterior Hox gene HoxA6 is associated with more posterior, non-duct-forming IM. Misexpression of HoxA6, but not of HoxB4, in prospective duct-forming regions of the IM resulted in repression of duct formation, suggesting a mechanism for the restriction of duct formation to the anterior-most IM. The results are discussed with respect to their implications for anterior-posterior patterning of kidney tissue and of mesoderm in general, and for the loss of duct-forming ability in more posterior regions of the IM that has occurred during vertebrate evolution. PMID:23034630

  3. Reducing Thermal Losses and Gains With Buried and Encapsulated Ducts in Hot-Humid Climates

    SciTech Connect

    Shapiro, C.; Magee, A.; Zoeller, W.

    2013-02-01

    The Consortium for Advanced Residential Buildings (CARB) monitored three houses in Jacksonville, FL, to investigate the effectiveness of encapsulated and encapsulated/buried ducts in reducing thermal losses and gains from ductwork in unconditioned attics. Burying ductwork beneath loose-fill insulation has been identified as an effective method of reducing thermal losses and gains from ductwork in dry climates, but it is not applicable in humid climates where condensation may occur on the outside of the duct jacket. By encapsulating the ductwork in closed cell polyurethane foam (ccSPF) before burial beneath loose-fill mineral fiber insulation, the condensation potential may be reduced while increasing the R-value of the ductwork.

  4. Postoperative Chemoradiotherapy for Extrahepatic Bile Duct Cancer

    SciTech Connect

    Park, Jin-hong; Choi, Eun Kyung; Ahn, Seung Do; Lee, Sang-wook; Song, Si Yeol; Yoon, Sang Min; Kim, Young Seok; Lee, Yu Sun; Lee, Sung-Gyu; Hwang, Shin; Lee, Young-Joo; Park, Kwang-Min; Kim, Tae Won; Chang, Heung Moon; Lee, Jae-Lyun; Kim, Jong Hoon

    2011-03-01

    Purpose: To evaluate the effect of postoperative concurrent chemoradiotherapy using three-dimensional conformal radiotherapy and to identify the prognostic factors that influence survival in patients with extrahepatic bile duct cancer. Methods and Materials: We retrospectively analyzed the data from 101 patients with extrahepatic bile duct cancer who had undergone postoperative concurrent chemoradiotherapy using three-dimensional conformal radiotherapy. Of the 101 patients, 52 (51%) had undergone complete resection (R0 resection) and 49 (49%) had microscopic or macroscopic residual tumors (R1 or R2 resection). The median radiation dose was 50 Gy. Also, 85 patients (84%) underwent concurrent chemotherapy with 5-fluorouracil. Results: The median follow-up period was 47 months for the surviving patients. The 5-year overall survival rate was 34% for all patients. A comparison between patients with R0 and R1 resection indicated no significant difference in the 5-year overall survival (44% vs. 33%, p = .2779), progression-free survival (35% vs. 22%, p = .3107), or locoregional progression-free survival (75% vs. 63%, p = .2784) rates. An analysis of the first failure site in the 89 patients with R0 or R1 resection indicated isolated locoregional recurrence in 7 patients. Elevated postoperative carbohydrate antigen 19-9 level was an independent prognostic factor for overall survival (p = .001) and progression-free survival (p = .033). A total of 3 patients developed Grade 3 or greater late toxicity. Conclusion: Adjuvant concurrent chemoradiotherapy using three-dimensional conformal radiotherapy appears to improve locoregional control and survival in extrahepatic bile duct cancer patients with R1 resection. The postoperative carbohydrate antigen 19-9 level might be a useful prognostic marker to select patients for more intensified adjuvant therapy.

  5. Radiation of sound from unflanged cylindrical ducts

    NASA Technical Reports Server (NTRS)

    Hartharan, S. L.; Bayliss, A.

    1983-01-01

    Calculations of sound radiated from unflanged cylindrical ducts are presented. The numerical simulation models the problem of an aero-engine inlet. The time dependent linearized Euler equations are solved from a state of rest until a harmonic solution is attained. A fourth order accurate finite difference scheme is used and solutions are obtained from a fully vectorized Cyber-203 computer program. Cases of both plane waves and spin modes are treated. Spin modes model the sound generated by a turbofan engine. Boundary conditions for both plane waves and spin modes are treated. Solutions obtained are compared with experiments conducted at NASA Langley Research Center.

  6. Levitated Duct Fan (LDF) Aircraft Auxiliary Generator

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.; Emerson, Dawn C.; Gallo, Christopher A.; Thompson, William K.

    2011-01-01

    This generator concept includes a novel stator and rotor architecture made from composite material with blades attached to the outer rotating shell of a ducted fan drum rotor, a non-contact support system between the stator and rotor using magnetic fields to provide levitation, and an integrated electromagnetic generation system. The magnetic suspension between the rotor and the stator suspends and supports the rotor within the stator housing using permanent magnets attached to the outer circumference of the drum rotor and passive levitation coils in the stator shell. The magnets are arranged in a Halbach array configuration.

  7. Anatomy of the nipple and breast ducts.

    PubMed

    Zucca-Matthes, Gustavo; Urban, Cícero; Vallejo, André

    2016-02-01

    Over time, variations of mastectomy came up and started allowing the oncological safety and the possibility of an immediate breast reconstruction. Nipple sparing mastectomy (NSM) procedures have strongly increased in frequency and have become one of the best alternatives to treat breast cancer, also improving overall aesthetic outcomes and the achievement of contralateral breast symmetry. The nipple areola-complex (NAC) must be considered the identity of the breast concerning self-esteem of patients. This paper will remind the main anatomical topics around the nipple and breast ducts. PMID:26855906

  8. [Carcinoma of the extrahepatic bile ducts].

    PubMed

    Cappelletti, F; Marzano, P F; Giacinti, I; Di Bello, M G; Maturo, A; Di Matteo, F M; Micacchi, M; Zaccagnino, P; Morucci, R; Petrassi, P; Ascenzi, P; Di Curzio, B

    1996-01-01

    In the last 5 years 25 patients (11 men, 14 women) with carcinoma of the extrahepatic biliary duct were studied. The most frequent localization of the carcinoma was the hepatic hilum. D.C.P. according to Whipple was possible only in one patient, while in 20 patients a palliative approach with external and internal biliary derivations was the choice. In the remaining 4 patients an explorative laparotomy with biopsy was performed. It is concluded that palliative resection allows for a better quality of life. PMID:9162182

  9. Porokeratotic eccrine ostial and dermal duct nevus

    PubMed Central

    Bandyopadhyay, Debabrata; Saha, Abanti; Das, Dipti; Das, Anupam

    2015-01-01

    Porokeratotic eccrine ostial and dermal duct nevus (PEODDN) is a rare nevoid condition characterized by asymptomatic grouped keratotic papules and plaques with a linear pattern on the extremities, having distinct porokeratotic histopathological features. The lesions usually present at birth or in childhood. We present here a case of late-onset PEODDN in a 23-year-old man who had lesions on the palm, forearm, arm and the chest along the lines of Blaschko, strictly localized to the left side of the body. PMID:25821735

  10. Anatomy of the nipple and breast ducts

    PubMed Central

    Urban, Cícero; Vallejo, André

    2016-01-01

    Over time, variations of mastectomy came up and started allowing the oncological safety and the possibility of an immediate breast reconstruction. Nipple sparing mastectomy (NSM) procedures have strongly increased in frequency and have become one of the best alternatives to treat breast cancer, also improving overall aesthetic outcomes and the achievement of contralateral breast symmetry. The nipple areola-complex (NAC) must be considered the identity of the breast concerning self-esteem of patients. This paper will remind the main anatomical topics around the nipple and breast ducts. PMID:26855906

  11. [Liver, bile ducts and pancreatic diseases].

    PubMed

    Kanno, T

    1995-06-01

    A fundamental guideline for the use of test results concerning liver, bile duct and pancreatic diseases was proposed in 1991 from the Japan Society of Clinical Pathology (JSCP). This guideline was principally based on the document of 1988 from the Committee on liver function tests of the Japanese Society of Gastroenterology (JSG). The document from the JSG was revised in May, 1994. Also a guideline for selection of markers of hepatitis virus in hepatic disorders, was proposed in January, 1994 from the same Committee of JSG. Here, we reevaluated and discussed the JSCP guideline as taking into consideration the two 1994 JSG documents. PMID:7602802

  12. Detonation duct gas generator demonstration program

    NASA Technical Reports Server (NTRS)

    Wortman, A.; Othmer, P.; Rostafinski, W.

    1992-01-01

    An experimental demonstration is presented for the generation of detonation waves that move periodically across high speed channel flow; these waves can compress the outflow from a low pressure compressor, and thereby both reduce the compressor requirements associated with conventional gas turbines and enhance thermodynamic efficiency through isochoric energy addition. By generating transient transverse waves, rather than standing waves, shock-wave losses are reduced by an order of magnitude; the result is a Humphrey cycle augmenting the basic Brayton-cycle gas turbine. Attention is presently given to results from an experimental detonation duct.

  13. Effectiveness of duct sealing and duct insulation in multi-family buildings. Final report

    SciTech Connect

    Karins, N.H.; Tuluca, A.; Modera, M.

    1997-07-01

    This research investigated the cost-effectiveness of sealing and insulating the accessible portions of duct systems exposed to unconditioned areas in multifamily housing. Airflow and temperature measurements were performed in 25 apartments served by 10 systems a 9 multi-family properties. The measurements were performed before and after each retrofit, and included apartment airflow (supply and return), duct system temperatures, system fan flow and duct leakage area. The costs for each retrofit were recorded. The data were analyzed and used to develop a prototypical multifamily house. This prototype was used in energy simulations (DOE-2.1E) and air infiltration simulations (COMIS 2.1). The simulations were performed for two climates: New York City and Albany. In each climate, one simulation was performed assuming the basement was tight, and another assuming the basement was leaky. Simulation results and average retrofit costs were used to calculate cost-effectiveness. The results of the analysis indicate that sealing leaks of the accessible ductwork is cost-effective under all conditions simulated (simple payback was between 3 and 4 years). Insulating the accessible ductwork, however, is only cost-effective for buildings with leaky basement, in both climates (simple paybacks were less than 5 years). The simple payback period for insulating the ducts in buildings with tight basements was greater than 10 years, the threshold of cost-effectiveness for this research. 13 refs., 5 figs., 27 tabs.

  14. Ultrasound imaging of the mouse pancreatic duct using lipid microbubbles

    NASA Astrophysics Data System (ADS)

    Banerjee, B.; McKeown, K. R.; Skovan, B.; Ogram, E.; Ingram, P.; Ignatenko, N.; Paine-Murrieta, G.; Witte, R.; Matsunaga, T. O.

    2012-03-01

    Research requiring the murine pancreatic duct to be imaged is often challenging due to the difficulty in selectively cannulating the pancreatic duct. We have successfully catheterized the pancreatic duct through the common bile duct in severe combined immune deficient (SCID) mice and imaged the pancreatic duct with gas filled lipid microbubbles that increase ultrasound imaging sensitivity due to exquisite scattering at the gas/liquid interface. A SCID mouse was euthanized by CO2, a midline abdominal incision made, the common bile duct cut at its midpoint, a 2 cm, 32 gauge tip catheter was inserted about 1 mm into the duct and tied with suture. The duodenum and pancreas were excised, removed in toto, embedded in agar and an infusion pump was used to instill normal saline or lipid-coated microbubbles (10 million / ml) into the duct. B-mode images before and after infusion of the duct with microbubbles imaged the entire pancreatic duct (~ 1 cm) with high contrast. The microbubbles were cavitated by high mechanical index (HMI) ultrasound for imaging to be repeated. Our technique of catheterization and using lipid microbubbles as a contrast agent may provide an effective, affordable technique of imaging the murine pancreatic duct; cavitation with HMI ultrasound would enable repeated imaging to be performed and clustering of targeted microbubbles to receptors on ductal cells would allow pathology to be localized accurately. This research was supported by the Experimental Mouse Shared Service of the AZ Cancer Center (Grant Number P30CA023074, NIH/NCI and the GI SPORE (NIH/NCI P50 CA95060).

  15. Seasonal variations of surface duct conditions in Ngaoundere, North Cameroon

    NASA Astrophysics Data System (ADS)

    Kaissassou, Samuel; Lenouo, André; Nzeukou, Armand; Tchawoua, Clément; Vondou, D. A.

    2015-12-01

    The seasonal variations of refractivity gradients from 104 to 3000 m above ground level in the troposphere layer are presented based on observations from the radiosonde station located in Ngaoundere (13.5°E, 7.3°N), a middle belt savannah region of Cameroon. Six years (2006-2011) of data from in situ measurements made by Agency for the Safety of Air Navigation in Africa and Madagascar (ASECNA) of the temperature, moisture, and pressure are used to determine the surface duct conditions over Ngaoundere region. Each time that a negative gradient from the Abel-retrieved refractivity profiles is seen, it implies the presence of a duct in this study. The occurrence of ducts strongly depends on the local climate and synoptic weather conditions which have an appreciable influence on the refractivity vertical profile, especially the seasonal north-south movement of the Inter Tropical Convergence Zone (ITCZ) which provides wet and dry seasons to the region. Monthly and seasonal variations of ducts were also determined from the measured data. The highest and the lowest occurrence rate of surface ducts were observed during the wet and the dry seasons, respectively. September appears as the month when most of the ducts occur at the rate of at least one duct per day. The median duct thickness and duct strength are high and strong during the wet season, whereas they are low and weak during the dry season. When the data are separated into stable and unstable atmospheric conditions, we noticed that surface duct characteristics show some seasonal differences. Surface ducts are found to be more frequent in a stable atmosphere than in an unstable atmosphere. Statistical results are discussed alongside with local meteorological conditions and weather systems affecting the town of Ngaoundere. Besides, comments are made on their prospective significance in the region.

  16. Collecting duct intercalated cell function and regulation.

    PubMed

    Roy, Ankita; Al-bataineh, Mohammad M; Pastor-Soler, Núria M

    2015-02-01

    Intercalated cells are kidney tubule epithelial cells with important roles in the regulation of acid-base homeostasis. However, in recent years the understanding of the function of the intercalated cell has become greatly enhanced and has shaped a new model for how the distal segments of the kidney tubule integrate salt and water reabsorption, potassium homeostasis, and acid-base status. These cells appear in the late distal convoluted tubule or in the connecting segment, depending on the species. They are most abundant in the collecting duct, where they can be detected all the way from the cortex to the initial part of the inner medulla. Intercalated cells are interspersed among the more numerous segment-specific principal cells. There are three types of intercalated cells, each having distinct structures and expressing different ensembles of transport proteins that translate into very different functions in the processing of the urine. This review includes recent findings on how intercalated cells regulate their intracellular milieu and contribute to acid-base regulation and sodium, chloride, and potassium homeostasis, thus highlighting their potential role as targets for the treatment of hypertension. Their novel regulation by paracrine signals in the collecting duct is also discussed. Finally, this article addresses their role as part of the innate immune system of the kidney tubule. PMID:25632105

  17. Evaporation duct effects at millimeter wavelengths

    NASA Astrophysics Data System (ADS)

    Anderson, K. D.

    1992-03-01

    The evaporation duct strongly influences low-altitude over-the-horizon propagation at millimeter wavelengths. Results from more than 2000 hours of propagation and meteorological measurements made at 94 GHz on a 40.6 km over-horizon, over-water path along the southern California coast show that the average received power was 63 dB greater than d for propagation in a nonducting, or standard, atmosphere; 90 percent of the measurements were at least 55 dB greater than diffraction. A numerical model of transmission loss based on the observed surface meteorology is discussed and results are compared to measured transmission loss. On average, modeling results underestimate observations by only 10 dB. In addition, results from modeling based on an independent climatology of evaporation duct heights for the area are shown to be adequate for most propagation assessment purposes. The reliability and reasonable accuracy of the numerical model provides a strong justification for utilizing the technique to assess millimeter wave communication and radar systems operating in many, if not all, ocean regions.

  18. Evaporation duct effects at millimeter wavelengths

    NASA Astrophysics Data System (ADS)

    Anderson, K. D.

    1990-03-01

    The evaporation duct strongly influences low-altitude over-the horizon propagation at millimeter wavelengths. Results from more than 2000 hours of propagation and meteorological measurements were made at 94 GHz on a 40.6 km over-horizon, over-water path along the southern California coast show that the average received power was 63 dB greater than expected for propagation in a nonconducting, or normal, atmosphere; 90 percent of the measurements were at least 55 dB greater than the normal atmosphere. A numerical model of transmission loss based on observed surface meteorology is discussed and results are compared to measured transmission loss. On average, modeling results underestimate the transmission loss by 10 dB. In addition, results from modeling based on an independent climatology of evaporation duct heights for the area are shown to be adequate for most propagation assessment purposes. The reliability and reasonable accuracy of the model provide a strong justification for utilizing the technique to assess millimeter wave communication and radar systems operating in many, if not all, ocean regions.

  19. 14 CFR 23.1103 - Induction system ducts.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Induction system ducts. 23.1103 Section 23.1103 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Induction System § 23.1103 Induction system ducts....

  20. 14 CFR 23.1103 - Induction system ducts.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Induction system ducts. 23.1103 Section 23.1103 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Induction System § 23.1103 Induction system ducts....

  1. 91. VIEW OF OBSOLETE AIRCONDITIONING DUCTS LOCATED IN NORTHWEST CORNER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    91. VIEW OF OBSOLETE AIR-CONDITIONING DUCTS LOCATED IN NORTHWEST CORNER OF ROOM, ABOVE SLC-3E AUTOPILOT EQUIPMENT. DIGITAL COUNTDOWN AND HOLD CLOCKS ON WALL LEFT OF DUCTS - Vandenberg Air Force Base, Space Launch Complex 3, Launch Operations Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  2. Sound waves in two-dimensional ducts with sinusoidal walls

    NASA Technical Reports Server (NTRS)

    Nayfeh, A. H.

    1974-01-01

    The method of multiple scales is used to analyze the wave propagation in two-dimensional hard-walled ducts with sinusoidal walls. For traveling waves, resonance occurs whenever the wall wavenumber is equal to the difference of the wavenumbers of any two duct acoustic modes. The results show that neither of these resonating modes could occur without strongly generating the other.

  3. 11. VIEW OF A HEATING DUCT SITUATED SOUTHWEST OF THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. VIEW OF A HEATING DUCT SITUATED SOUTHWEST OF THE FAN HOUSE, ALONG THE MINE ROAD. THE BURNED RUINS OF THE MINE OFFICE ARE LOCATED ON THE FAR SIDE OF THE HEATING DUCT, TO THE NORTHWEST. - Tower Hill No. 2 Mine, Approximately 0.47 mile Southwest of intersection of Stone Church Road & Township Route 561, Hibbs, Fayette County, PA

  4. Scale Model Experiments on Sound Propagation From a Mach 2.5 Cold Nitrogen Jet Flowing Through a Rigid-Walled Duct With a J-Deflector

    NASA Technical Reports Server (NTRS)

    Kandula, Max; Vu, Bruce

    2003-01-01

    The Launch Systems Testbed (LST) represents the evolution of vibroacoustics research and development work performed at NASA John F. Kennedy Space Center (KSC) over the last 15 years. The LST is located at the Launch Equipment Test Facility (LETF) in the KSC industrial complex. The LETF is operated by Sierra Lobo, Inc., as a member of University-Affiliated Technology Development Contract (USTDC) to KSC Spaceport and Engineering and Technology Directorate (YA), with ASRC Aerospace Corporation as a the prime contractor. Trajectory Simulation Mechanism (TSM) is a major component of the LST, developed specifically to simulate nonstationary acoustic loads on launch pad structures, vehicles, and payloads. TSM enhances the capabilities within LST for simulating launch environments of future vehicles. The scaled launch environments will be used to predict the full-scale launch environment via an appropriate scaling procedure. Air Force Research Laboratory (AFRL) has tasked NASA KSC to perform a basic technology test program in support of developing a low-cost clean pad (incorporating passive mitigation techniques) for future launch vehicles. The overall goal of the program is to develop innovative launch exhaust management systems, which effectively reduce launch acoustic environment with innovative duct designs, while eliminating traditional sound suppression water systems. Passive techniques, such as nontraditional duct geometries, resonators, and diffusers, etc., will be investigated. The overall goals are to advance innovative concepts for a clean pad while developing ideas to reduce transmitted sound via investigation and modeling of jet exhaust acoustic and flow field characteristics. The series of tests outlined in this report represent baseline tests and are geared towards defining the acoustic load environment on the TSM pad for open and closed duct configurations. This report summarizes the cold jet acoustic testing for Mach 2.5 supersonic nitrogen jet issuing

  5. Duct thermal performance models for large commercial buildings

    SciTech Connect

    Wray, Craig P.

    2003-10-01

    Despite the potential for significant energy savings by reducing duct leakage or other thermal losses from duct systems in large commercial buildings, California Title 24 has no provisions to credit energy-efficient duct systems in these buildings. A substantial reason is the lack of readily available simulation tools to demonstrate the energy-saving benefits associated with efficient duct systems in large commercial buildings. The overall goal of the Efficient Distribution Systems (EDS) project within the PIER High Performance Commercial Building Systems Program is to bridge the gaps in current duct thermal performance modeling capabilities, and to expand our understanding of duct thermal performance in California large commercial buildings. As steps toward this goal, our strategy in the EDS project involves two parts: (1) developing a whole-building energy simulation approach for analyzing duct thermal performance in large commercial buildings, and (2) using the tool to identify the energy impacts of duct leakage in California large commercial buildings, in support of future recommendations to address duct performance in the Title 24 Energy Efficiency Standards for Nonresidential Buildings. The specific technical objectives for the EDS project were to: (1) Identify a near-term whole-building energy simulation approach that can be used in the impacts analysis task of this project (see Objective 3), with little or no modification. A secondary objective is to recommend how to proceed with long-term development of an improved compliance tool for Title 24 that addresses duct thermal performance. (2) Develop an Alternative Calculation Method (ACM) change proposal to include a new metric for thermal distribution system efficiency in the reporting requirements for the 2005 Title 24 Standards. The metric will facilitate future comparisons of different system types using a common ''yardstick''. (3) Using the selected near-term simulation approach, assess the impacts of

  6. An electronically tunable duct silencer using dielectric elastomer actuators.

    PubMed

    Lu, Zhenbo; Godaba, Hareesh; Cui, Yongdong; Foo, Choon Chiang; Debiasi, Marco; Zhu, Jian

    2015-09-01

    A duct silencer with tunable acoustic characteristics is presented in this paper. Dielectric elastomer, a smart material with lightweight, high elastic energy density and large deformation under high direct current/alternating current voltages, was used to fabricate this duct silencer. The acoustic performances and tunable mechanisms of this duct silencer were experimentally investigated. It was found that all the resonance peaks of this duct silencer could be adjusted using external control signals without any additional mechanical part. The physics of the tunable mechanism is further discussed based on the electro-mechanical interactions using finite element analysis. The present promising results also provide insight into the appropriateness of the duct silencer for possible use as next generation acoustic treatment device to replace the traditional acoustic treatment. PMID:26428819

  7. Heat Transfer in Conical Corner and Short Superelliptical Transition Ducts

    NASA Technical Reports Server (NTRS)

    Poinsatte, Philip; Thurman, Douglas; Hippensteele, Steven

    2008-01-01

    Local surface heat transfer measurements were experimentally mapped using a transient liquid-crystal heat-transfer technique on the surface of two circular-to-rectangular transition ducts. One has a transition cross section defined by conical corners (Duct 1) and the other by an elliptical equation with changing coefficients (Duct 2). Duct 1 has a length-to-diameter ratio of 0.75 and an exit plane aspect ratio of 1.5. Duct 2 has a length-to-diameter ratio of 1.0 and an exit plane aspect ratio of 2.9. Test results are reported for various inlet-diameter-based Reynolds numbers ranging from 0.45 106 to 2.39 106 and two freestream turbulence intensities of about 1 percent, which is typical of wind tunnels, and up to 16 percent, which may be more typical of real engine conditions.

  8. Anicteric early bile duct carcinoma detection with magnetic resonance cholangiopancreatography.

    PubMed

    Oshikiri, Taro; Morita, Takayuki; Fujita, Miyoshi; Miyasaka, Yuji; Senmaru, Naoto; Yamada, Hidehisa; Kondo, Satoshi; Katoh, Hiroyuki

    2005-01-01

    The poor prognosis of extrahepatic bile duct carcinoma makes early detection and diagnosis essential for positive patient outcomes. We describe 2 cases of jaundice-free early extrahepatic bile duct carcinoma detected by magnetic resonance cholangiopancreatography. Extrahepatic bile duct carcinoma was discovered incidentally in patient 1 by magnetic resonance cholangiopancreatography during evaluation of a gallbladder stone. In patient 2, extrahepatic bile duct carcinoma was found during a routine health maintenance exam. Both patients underwent radical surgical intervention. Both patient 1 and 2 have remained in good health for over one year, 3.5 and one year, respectively, and have not exhibited any signs or symptoms of relapse or cancer recurrence. Based on these cases, it appears that magnetic resonance cholangiopancreatography can play a significant role in the early detection of extrahepatic bile duct carcinoma and improve disease prognosis. PMID:15816438

  9. Extravasation Mucocele Arising from a Lingual Thyroglossal Duct Remnant

    PubMed Central

    Nakahira, Mitsuhiko; Nakatani, Hiroaki

    2015-01-01

    Although a thyroglossal duct cyst is a congenital anomaly, it can also appear in adults. Despite the presence of embryological remnants, it is still unclear why the cyst should suddenly develop later in life. We report a case of a 46-year-old male with an extravasation mucocele arising from a long-standing lingual thyroglossal duct remnant. MRI demonstrated a lingual cystic lesion near the hyoid bone associated with a suprahyoid tract-like structure masquerading as a thyroglossal duct cyst. However, histopathological examination demonstrated a mucocele secondary to a rupture of a thyroglossal duct remnant with numerous intramural heterotopic salivary glands. We propose a new mechanism of an acquired cystic formation of this congenital disease that excessive production of mucus from heterotopic salivary glands and a physical trauma such as swallowing may lead to extravasation of mucus from the thyroglossal duct. PMID:25861502

  10. Extravasation mucocele arising from a lingual thyroglossal duct remnant.

    PubMed

    Nakahira, Mitsuhiko; Nakatani, Hiroaki

    2015-01-01

    Although a thyroglossal duct cyst is a congenital anomaly, it can also appear in adults. Despite the presence of embryological remnants, it is still unclear why the cyst should suddenly develop later in life. We report a case of a 46-year-old male with an extravasation mucocele arising from a long-standing lingual thyroglossal duct remnant. MRI demonstrated a lingual cystic lesion near the hyoid bone associated with a suprahyoid tract-like structure masquerading as a thyroglossal duct cyst. However, histopathological examination demonstrated a mucocele secondary to a rupture of a thyroglossal duct remnant with numerous intramural heterotopic salivary glands. We propose a new mechanism of an acquired cystic formation of this congenital disease that excessive production of mucus from heterotopic salivary glands and a physical trauma such as swallowing may lead to extravasation of mucus from the thyroglossal duct. PMID:25861502

  11. The surface evaporative duct height product: An evaluation

    NASA Astrophysics Data System (ADS)

    Thompson, William T.

    1987-12-01

    The existence of a surface evaporative duct has many serious operational implications. One of the most serious and obvious implications is that the extended range of the radar will allow distant hostile units to detect the radar (and to be detected by the radar). Thus, the existence of a surface evaporative duct is an important component of the decision on whether or not to radiate. Another consequence of the duct is that a radar hole will exist between the top of the duct and the base of the lobes unaffected by the duct (see figure 1). Hostile aircraft or missiles will thus be able to approach the radar undetected. Conversely, knowledge of the refractivity profile in the vicinity of enemy radars can be turned to tactical advantage.

  12. A new evaporation duct climatology over the South China Sea

    NASA Astrophysics Data System (ADS)

    Shi, Yang; Yang, Kunde; Yang, Yixin; Ma, Yuanliang

    2015-10-01

    The climatology of evaporation ducts is important for shipborne electromagnetic system design and application. The evaporation duct climatology that is currently used for such applications was developed in the mid 1980s; this study presents efforts to improve it over the South China Sea (SCS) by using a state-of-the-art evaporation duct model and an improved meteorology dataset. This new climatology provides better evaporation duct height (EDH) data over the SCS, at a higher resolution of 0.312°×0.313°. A comparison between the new climatology and the old one is performed. The monthly average EDH in the new climatology is between 10 and 12 m over the SCS, higher than that in the old climatology. The spatiotemporal characteristics of the evaporation duct over the SCS in different months are analyzed in detail, based on the new climatology.

  13. Regeneratively cooled transition duct with transversely buffered impingement nozzles

    SciTech Connect

    Morrison, Jay A; Lee, Ching-Pang; Crawford, Michael E

    2015-04-21

    A cooling arrangement (56) having: a duct (30) configured to receive hot gases (16) from a combustor; and a flow sleeve (50) surrounding the duct and defining a cooling plenum (52) there between, wherein the flow sleeve is configured to form impingement cooling jets (70) emanating from dimples (82) in the flow sleeve effective to predominately cool the duct in an impingement cooling zone (60), and wherein the flow sleeve defines a convection cooling zone (64) effective to cool the duct solely via a cross-flow (76), the cross-flow comprising cooling fluid (72) exhausting from the impingement cooling zone. In the impingement cooling zone an undimpled portion (84) of the flow sleeve tapers away from the duct as the undimpled portion nears the convection cooling zone. The flow sleeve is configured to effect a greater velocity of the cross-flow in the convection cooling zone than in the impingement cooling zone.

  14. Rhinosporidiosis in the parotid duct: a rare case report.

    PubMed

    Panda, Swagatika; Lenka, Sthitaprajna; Padhiary, Subrat K; Sahoo, Sujit R; Srivastava, Gunjan

    2013-11-01

    Endemic to South India and Sri Lanka, Rhinosporidiosis is a chronic granulomatous infection caused by an agent of uncertain taxonomy: Rhinosporidium seeberi. Although it commonly manifests as a proliferative nasal lesion, many cases of Rhinosporidiosis have been reported where it has appeared as an extranasal lesion. The reported extranasal sites include the eye, ear, trachea, and parotid duct. However, the involvement of the parotid duct is quite rare, even among extranasal sites. The case presented is an adult female from the non-endemic zone of East India with a proliferative mass in the parotid duct. Although Rhinosporidiosis was not taken into consideration in the clinical differential diagnosis, eventual histopathological diagnosis confirmed Rhinosporidiosis. As this appears to be the second case of Rhinosporidiosis in the parotid duct in East India in 4 years, we encourage clinicians to be flexible in the differential diagnosis of proliferative growth in the parotid duct, even in those from non-endemic areas. PMID:23371913

  15. [Salivary duct carcinoma--a clinicopathological analysis of five cases].

    PubMed

    Bień, Stanisław; Sygut, Jacek; Kopczyński, Janusz; Postuła, Sylwia; Ziółkowska, Magdalena

    2007-01-01

    The 5 cases of salivary duct carcinoma (SDC); very rare, but distinct group of highly malignant salivary gland tumor are presented, and difficulties with pathological and clinical diagnosis is discussed. The SDC developed in single cases in parotid salivary gland, submandibular salivary and in mucosa of maxillary sinus, pyriform fossa and oral cavity (check). In 3 cases the second malignant tumor was present--synchronously (SDC + pleomorphic adenoma in parotid gland; SDC + squamous cell carcinoma in hypopharynx) or metachroneously (squamous cell carcinoma of upper lip followed by SDC). In one case the high levels of PSA suggesting of metastases from unknown primary within the prostate gland, or PSA expression related to SDC was observed. The four patients received radical treatment - surgical resection followed by radiotherapy; in one case only palliative treatment was applied, due to patient's poor general condition and high advancement of the primary disease. The observation ranged from 10 to 77 months (average time--31 months). The one patient died 13 months after diagnosis and palliative treatment. The three patients are alive with distant metastases to the lung and bones (77, 38 and 18 months after primary treatment was completed). Only one patient with 10 months observation after treatment is living without symptoms of recurrence or metastases. PMID:17605416

  16. Jet noise characteristics of unsuppressed duct burning turbofan exhaust system

    NASA Technical Reports Server (NTRS)

    Packman, A. B.; Kozlowski, H.; Gutierrez, O.

    1976-01-01

    Recent aero-acoustic tests of model coannular nozzles have shown that less noise is generated if the higher-velocity jet is exhausted from the outer annular passage rather than from the primary nozzle. These findings are of particular significance to a duct-burning turbofan (DBTF) engine being studied for application to an advanced supersonic transport. Unlike conventional turbofan engines that have peak velocities from the primary nozzle, it is possible to design a DBTF engine to have a fan velocity higher than that of the primary flow. Results are presented for a NASA-sponsored model test program that covers a range of fan to primary-area ratios from 0.75 to 1.2, and a range of fan to primary-velocity ratios from 0.4 to 2.8. Correlations are given that relate radiated sound power to fan velocity, fan to primary-velocity ratio, and fan to primary-area ratio. Corresponding exhaust-plume velocity-traverse data are presented which suggest that the observed noise benefits may be due to the more rapid decay of the annular flow because of shear stresses on the inner surface that result from the lower-velocity primary flow.

  17. Aeroacoustic interaction in a corrugated duct

    NASA Astrophysics Data System (ADS)

    Kop'ev, V. F.; Mironov, M. A.; Solntseva, V. S.

    2008-03-01

    The sound generation by an air flow in a corrugated tube is studied experimentally for different values of the corrugation pitch and different tube lengths. The Strouhal numbers of sound generated in different tubes with different flow velocities lie within 0.4-0.6. As the flow velocity increases, the Strouhal number decreases. The effect of sound absorption by an air flow in a corrugated duct is described: in a corrugated tube with a flow, at frequencies below the generation frequency, the absorption of sound produced by an external source is observed. A semiempirical model of aeroacoustic interaction in a corrugated tube is proposed. The model provides a qualitative agreement with the experiment.

  18. Acoustic propagation in rigid ducts with blockage

    NASA Technical Reports Server (NTRS)

    El-Raheb, M.; Wagner, P.

    1982-01-01

    Acoustic levitation has been suggested for moving nonmagnetic material in furnaces for heat processing in space experiments. Basically, acoustic standing waves under resonant conditions are excited in the cavity of the furnace while the material blockage is located at a pressure node and thus at a maximum gradient. The position of the blockage is controlled by displacing the node as a result of frequency change. The present investigation is concerned with the effect of blockage on the longitudinal and transverse resonances of a cylindrical cavity, taking into account the results of a one-dimensional and three-dimensional (3-D) analysis. Based on a Green's function surface element method, 3-D analysis is tested experimentally and proved to be accurate over a wide range of geometric parameters and boundary shapes. The shift in resonance depends on the change in pressure gradient and duct shortening caused by the blockage.

  19. ADAM: An Axisymmetric Duct Aeroacoustic Modeling system

    NASA Astrophysics Data System (ADS)

    Abrahamson, A. L.

    1983-01-01

    An interconnected system of computer programs for analyzing the propagation and attenuation of sound in aeroengine ducts containing realistic compressible subsonic mean flows, ADAM was developed primarily for research directed towards the reduction of noise emitted from turbofan aircraft engines. The two basic components are a streamtube curvature program for determination of the mean flow, and a finite element code for solution of the acoustic propagation problem. The system, which has been specifically tailored for ease of use, is presently installed at NASA Langley Reseach Center on a Control Data Cyber 175 Computer under the NOS Operating system employing a Tektronix terminal for interactive graphics. The scope and organization of the ADAM system is described. A users guide, examples of input data, and results for selected cases are included.

  20. Live 3D image overlay for arterial duct closure with Amplatzer Duct Occluder II additional size.

    PubMed

    Goreczny, Sebstian; Morgan, Gareth J; Dryzek, Pawel

    2016-03-01

    Despite several reports describing echocardiography for the guidance of ductal closure, two-dimensional angiography remains the mainstay imaging tool; three-dimensional rotational angiography has the potential to overcome some of the drawbacks of standard angiography, and reconstructed image overlay provides reliable guidance for device placement. We describe arterial duct closure solely from venous approach guided by live three-dimensional image overlay. PMID:26358032

  1. An analytic Green's function for a lined circular duct containing uniform mean flow

    NASA Astrophysics Data System (ADS)

    Rienstra, Sjoerd W.; Tester, Brian J.

    2008-11-01

    An analytic Green's function is derived for a lined circular duct, both hollow and annular, containing uniform mean flow, from first principles by Fourier transformation. The derived result takes the form of a common mode series. We show that the analytic Green's function for a lined hollow circular duct, containing uniform mean flow, is essentially identical to that used by Tester et al. in the Cargill splice scattering model. The explicit form of the Green's function for the annular duct is new. A more comprehensive causality analysis suggests the possibility of certain upstream modes being really downstream instabilities. As their growth rates are usually exceptionally large, including these modes as instabilities is both not practical and in disagreement with most (not all) experiments. Therefore, we outline the possibility but do not include them in the presented examples. We follow the "modelling assumption" that all modes decay in their respective direction of propagation. To illustrate the advantages of our analytic result compared to the matrix inversion technique of Alonso et al., we compute the mode amplitudes from both methods for a typical aircraft engine intake condition. The comparisons show good agreement without flow, irrespective of how many modes are included in the matrix inversion for the numerical mode amplitudes. With flow, the mode amplitudes do not agree but as the number of modes included in the matrix inversion is increased, enough to include any important surface waves, the numerically obtained modal amplitudes of Alonso et al. appear to be converging to the present analytical result. In practical applications our closed form analytic Green's function will be computationally more efficient, especially at high frequencies of practical interest to aero-engine applications, and the analytic form for the mode amplitudes could permit future modelling advances not possible from the numerical equivalent. It also may have application to post

  2. Modeling low elevation GPS signal propagation in maritime atmospheric ducts

    NASA Astrophysics Data System (ADS)

    Zhang, Jinpeng; Wu, Zhensen; Wang, Bo; Wang, Hongguang; Zhu, Qinglin

    2012-05-01

    Using the parabolic wave equation (PWE) method, we model low elevation GPS L1 signal propagation in maritime atmospheric ducts. To consider sea surface impedance, roughness, and the effects of earth's curvature, we propose a new initial field model for the GPS PWE split-step solution. On the basis of the comparison between the proposed model and the conventional initial field model for a smooth, perfectly conducting sea surface on a planar earth, we conclude that both the amplitude and phase of the initial field are influenced by surface impedance and roughness, and that the interference behavior between direct and reflected GPS rays is affected by earth's curvature. The performance of the proposed model is illustrated with examples of low elevation GPS L1 signal propagation in three types of ducts: an evaporation duct, a surface-based duct, and an elevated duct. The GPS PWE is numerically implemented using the split-step discrete mixed Fourier transform algorithm to enforce impedance-type boundary conditions at the rough sea surface. Because the GPS signal is right hand circularly polarized, we calculate its power strength by combining the propagation predictions of the horizontally and the vertically polarized components. The effects of the maritime atmospheric ducts on low elevation GPS signal propagation are demonstrated according to the presented examples, and the potential applications of the GPS signals affected by ducts are discussed.

  3. Ducted fan type gas turbine engine power plants

    SciTech Connect

    Balzer, R.L.

    1992-02-25

    This patent describes a ducted fan type power plant which is cable of generating reverse thrust. It comprises: a gas turbine engine; a fan driven by the engine; an elongated bypass duct which is open at its front and rear ends and surrounds the fan, the bypass duct having a fixed forward section and a rear section which can be translated away from the fixed section as the pitch of the fan blades is reversed to reverse the flow of air through the bypass duct and generate a thrust directed from the front toward the rear of the power plant, thereby allowing air to be induced into the bypass duct through the downstream end thereof and also through the annular gap between the fixed and translated, rear sections of the bypass duct; means for generating a supply of high velocity fluid; means for injecting the high velocity fluid into the bypass duct from a locus to the rear means for delivering the high velocity fluid from the generating means to the injecting means.

  4. Aero-acoustic performance characteristics of duct burning turbofan exhaust nozzles

    NASA Technical Reports Server (NTRS)

    Kozlowski, H.; Packman, A. B.; Gutierrez, O.

    1976-01-01

    A recent experimental investigation has identified the aero/acoustic characteristics of exhaust nozzles for duct heating turbofan engines over a range of simulated flow conditions. Jet noise and performance levels are summarized for a series of coannular nozzles representing both acoustically suppressed and unsuppressed designs operating in a static environment. The basic coannular nozzles were found to provide inherent noise suppression. Multi-element suppressor nozzles provided additional noise suppression, but with appreciable thrust loss. The impact of these results on the advanced supersonic transport studies is also presented, indicating potentially large reductions in take-off gross weight or community noise footprints.

  5. In-Duct and Far-Field Experimental Measrements from the ANCF for the Purpose of Improved Broadband Liner Optimization

    NASA Technical Reports Server (NTRS)

    Sutliff, Daniel L.; Jones, Michael G.; Nark, Douglas M.

    2014-01-01

    A process for the design and evaluation of novel broadband acoustic liner concepts with limited fan source information is being evaluated. A pair of advanced broad-bandwidth liners were designed and manufactured for the NASA Glenn Research Center's Advanced Noise Control Fan (ANCF): (i) a constant impedance liner and (ii) a variable impedance liner. The insertion loss of both liners was measured in-duct utilizing the ANCF's Configurable Fan Artificial Noise System in a clean configuration with no-flow. Additionally, the acoustic characteristics of the Variable Impedance Liner were measured in the standard ANCF configuration with and without flow. The experimental setup, in-duct mode power levels, and far-field directivity are presented herein.

  6. Finite-amplitude waves in cylindrical lined ducts

    NASA Technical Reports Server (NTRS)

    Nayfeh, A. H.; Tsai, M.-S.

    1974-01-01

    A second-order uniformly valid expansion is obtained for nonlinear waves propagating in a cylindrical duct lined with a point-reacting acoustic material that consists of a porous sheet followed by honey-comb cavities and backed by the impervious walls of the duct. The effect of the liner is taken into account by coupling the waves in the duct with those in the liner. As in the two-dimensional case, the nonlinearity increases the attenuation rate at all frequencies except in narrow bandwidths around the resonant frequencies, irrespective of the geometrical dimensions of the liner or the acoustic properties of the porous sheet.

  7. Subsonic Flows through S-Ducts with Flow Control

    NASA Astrophysics Data System (ADS)

    Chen, Yi

    An inlet duct of an aircraft connects the air intake mounted on the fuselage to the engine within the aircraft body. The ideal outflow quality of the duct is steady, uniform and of high total pressure. Recently compact S-shaped inlet ducts are drawing more attention in the design of UAVs with short propulsion system. Compact ducts usually involve strong streamwise adverse pressure gradient and transverse secondary flow, leading to large-scale harmful vortical structures in the outflow. To improve the outflow quality modern flow control techniques have to be applied. Before designing successful flow control methods a solid understanding of the baseline flow field with the duct is crucial. In this work the fundamental mechanism of how the three dimensional flow topology evolves when the relevant parameters such as the duct geometry and boundary layer thickness are varied, is studied carefully. Two distinct secondary-flow patterns are identified. For the first time the sensitivity of the flow topology to the inflow boundary layer thickness in long ducts is clearly addressed. The interaction between the transverse motion induced by the transverse pressure gradient and the streamwise separation is revealed as the crucial reason for the various flow patterns existing in short ducts. A non-symmetric flow pattern is identified for the first time in both experiments and simulations in short ducts in which the intensity of the streamwise separation and the transverse invasion are in the same order of magnitude. A theory of energy accumulation and solution bifurcation is used to give a reasonable explanation for this non-symmetry. After gaining the knowledge of where and how the harmful vortical structures are generated several flow control techniques are tested to achieve a better outflow quality. The analysis of the flow control cases also provides a deeper insight into the behavior of the three-dimensional flow within the ducts. The conventional separation control method

  8. Modal density function and number of propagating modes in ducts

    NASA Technical Reports Server (NTRS)

    Rice, E. J.

    1976-01-01

    Often raised questions in duct sound propagation studies involve the total number of propagating modes, the number of propagating radial modes for a particular spinning lobe number, and the number of modes possible between two given values of cutoff ratio or eigenvalue. These questions can be answered approximately by using the modal distribution function which is the integral of the modal density function for ducts in a manner similar to that previously published for architectural acoustics. The modal density functions are derived for rectangular and circular ducts with a uniform steady flow. Results from this continuous theory are compared to the actual (discrete) modal distributions.

  9. Millimetre-wave propagation in the evaporation duct

    NASA Astrophysics Data System (ADS)

    Levy, M. F.; Craig, K. H.

    1990-03-01

    Recent developments in propagation modeling based on the Parabolic Equation Method allow the forecasting of two-dimensional antenna coverage diagrams at millimeter wavelengths, in a dispersive atmosphere with arbitrary two-dimensional variation of the refractive index. The model was applied successfully to mm-wave propagation in the evaporation duct. The evaporation duct height is not sufficient to characterize mm-wave propagation, and information on the water vapor content is essential for the correct modeling of atmospheric absorption. Turbulence simulations were carried out, showing marked scintillation, effects in the evaporation duct. The method can be applied to arbitrary refractivity spectra, and gives a complete numerical description of the field statistics.

  10. Influence of evaporation ducts on radar sea return

    NASA Astrophysics Data System (ADS)

    Reilly, J. P.; Dockery, G. D.

    1990-04-01

    Modeling of radar sea return is discussed with consideration of propagation conditions. Both the intensity and propagation direction of energy incident at the sea surface can be significantly affected by the refractive condition of the atmosphere. The paper describes and evaluates a model that incorporates both of these effects for the situation where the propagation conditions are characterized as evaporation ducts. Such ducts are the most persistent marine propagation environment on a worldwide basis for low-altitude propagation. It is shown that commonly encountered evaporation ducts can profoundly affect sea returns.

  11. Determination of the evaporation duct height from standard meteorological data

    NASA Astrophysics Data System (ADS)

    Ivanov, V. K.; Shalyapin, V. N.; Levadnyi, Yu. V.

    2007-02-01

    Four models used for evaluating the height of the evaporation duct from measured atmospheric pressure, water and air temperatures, and air humidity are considered.The calculated results are compared with the duct heights measured during two oceanographic expeditions in the tropical zone of the Atlantic Ocean and the equatorial zone of the Indian Ocean. The sensitivity of models to the errors in the meteorological parameters is investigated. It is shown that, in the case of unstable stratification, the heights of ducts in the 5 20-m range can be evaluated with an error of about 2.5 m. Recommendations for selection of optimal models are given.

  12. EFFECT OF AIRFLOW AND HEAT INPUT RATES ON DUCT EFFICIENCY.

    SciTech Connect

    ANDREWS,J.W.

    2003-05-28

    Reducing the airflow and heat input rates of a furnace that is connected to a duct system in thermal contact with unconditioned spaces can significantly reduce thermal distribution efficiency. This is a straightforward theoretical calculation based on the increased residence time of the air in the duct at the lower flow rate, which results in greater conduction losses. Experimental tests in an instrumented residential-size duct system have confirmed this prediction. Results are compared with the heat-loss algorithm in ASHRAE Standid 152P. The paper concludes with a discussion of possible remedies for this loss of efficiency in existing systems and optional design strategies in new construction.

  13. Duplicated extrahepatic bile duct identified following cholecystectomy injury

    PubMed Central

    Hoepfner, Lauren; Sweeney, Mary Katherine; White, Jared A.

    2016-01-01

    Though variations of intrahepatic biliary anatomy are quite common, duplication of the extrahepatic biliary system is extremely rare and reported infrequently in the literature. Laparoscopic cholecystectomy is one of the most common general surgery procedures performed. Unfortunately, iatrogenic bile duct injuries can contribute to significant morbidity including hospital readmissions, infectious complications and death. Anomalous extrahepatic biliary anatomy may be one of the factors, which increases the likelihood of bile duct injury during laparoscopic cholecystectomy. We present a case of an iatrogenic bile duct injury that occurred during a laparoscopic cholecystectomy, in which a duplicated extrahepatic biliary system was identified intraoperatively during the definitive operative repair. PMID:27141049

  14. Transition duct with late injection in turbine system

    SciTech Connect

    LeBegue, Jeffrey Scott; Pentecost, Ronnie Ray; Flanagan, James Scott; Kim, Won -Wook; McMahan, Kevin Weston

    2015-09-15

    A system for supplying an injection fluid to a combustor is disclosed. The system includes a transition duct comprising an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The passage defines a combustion chamber. The system further includes a tube providing fluid communication for the injection fluid to flow through the transition duct and into the combustion chamber.

  15. Advanced absorber assembly design for breeder reactors

    SciTech Connect

    Pitner, A.L.; Birney, K.R.

    1980-01-01

    An advanced absorber assembly design has been developed for breeder reactor control rod applications that provides for improved in-reactor performance, longer lifetimes, and reduced fabrication costs. The design comprises 19 vented pins arranged in a circular array inside of round duct tubes. The absorber material is boron carbide; cladding and duct components are constructed from the modified Type 316 stainless steel alloy. Analyses indicate that this design will scram 30 to 40% faster than the reference FFTF absorber assembly. The basic design characteristics of this advanced FFTF absorber assembly are applicable to large core breeder reactor design concepts.

  16. Observations of Strong Surface Radar Ducts over the Persian Gulf.

    NASA Astrophysics Data System (ADS)

    Brooks, Ian M.; Goroch, Andreas K.; Rogers, David P.

    1999-09-01

    Ducting of microwave radiation is a common phenomenon over the oceans. The height and strength of the duct are controlling factors for radar propagation and must be determined accurately to assess propagation ranges. A surface evaporation duct commonly forms due to the large gradient in specific humidity just above the sea surface; a deeper surface-based or elevated duct frequently is associated with the sudden change in temperature and humidity across the boundary layer inversion.In April 1996 the U.K. Meteorological Office C-130 Hercules research aircraft took part in the U.S. Navy Ship Antisubmarine Warfare Readiness/Effectiveness Measuring exercise (SHAREM-115) in the Persian Gulf by providing meteorological support and making measurements for the study of electromagnetic and electro-optical propagation. The boundary layer structure over the Gulf is influenced strongly by the surrounding desert landmass. Warm dry air flows from the desert over the cooler waters of the Gulf. Heat loss to the surface results in the formation of a stable internal boundary layer. The layer evolves continuously along wind, eventually forming a new marine atmospheric boundary layer. The stable stratification suppresses vertical mixing, trapping moisture within the layer and leading to an increase in refractive index and the formation of a strong boundary layer duct. A surface evaporation duct coexists with the boundary layer duct.In this paper the authors present aircraft- and ship-based observations of both the surface evaporation and boundary layer ducts. A series of sawtooth aircraft profiles map the boundary layer structure and provide spatially distributed estimates of the duct depth. The boundary layer duct is found to have considerable spatial variability in both depth and strength, and to evolve along wind over distances significant to naval operations (100 km). The depth of the evaporation duct is derived from a bulk parameterization based on Monin-Obukhov similarity theory

  17. Intraluminal measurement of papillary duct urine pH, in vivo: a pilot study in the swine kidney.

    PubMed

    Handa, Rajash K; Lingeman, James E; Bledsoe, Sharon B; Evan, Andrew P; Connors, Bret A; Johnson, Cynthia D

    2016-06-01

    We describe the in vivo use of an optic-chemo microsensor to measure intraluminal papillary duct urine pH in a large mammal. Fiber-optic pH microsensors have a tip diameter of 140-µm that allows insertion into papillary Bellini ducts to measure tubule urine proton concentration. Anesthetized adult pigs underwent percutaneous nephrolithotomy to access the lower pole of the urinary collecting system. A flexible nephroscope was advanced towards an upper pole papilla with the fiber-optic microsensor contained within the working channel. The microsensor was then carefully inserted into Bellini ducts to measure tubule urine pH in real time. We successfully recorded tubule urine pH values in five papillary ducts from three pigs (1 farm pig and 2 metabolic syndrome Ossabaw pigs). Our results demonstrate that optical microsensor technology can be used to measure intraluminal urine pH in real time in a living large mammal. This opens the possibility for application of this optical pH sensing technology in nephrolithiasis. PMID:26526044

  18. Enhanced Mixing in a Rectangular Duct

    NASA Technical Reports Server (NTRS)

    Liscinsky, D. S.; True, B.

    2003-01-01

    An experimental investigation of the mixing of non-reacting opposed rows of jets injected normal to a confined rectangular crossflow has been conducted. Planar Mie-scattering was used to measure the time-average concentration distribution of the jet fluid in planes perpendicular to the duct axis. Particular emphasis was placed on the study of closely spaced orifice configurations applicable to the mixing zone of an RQL combustor. Baseline studies were performed of mixing under "ideal" conditions, i.e., plenum fed jets injecting into a crossflow uniform in velocity and turbulence intensity. In addition, more practical ("non-ideal") issues encountered during hardware design were also studied. As in other studies, mixing effectiveness, determined using a spatial unmixedness parameter based on the variance of mean jet concentration distributions, was found to be optimum when the spacing-to-duct-height ratio was inversely proportional to the square root of the jet-to-mainstream momentum-flux ratio. This relationship is suitable for design under ideal flow conditions. Inlet flow boundary conditions of the jet and approach flow (mainstream) were found to strongly influence mixing performance, but no attempt was made to determine optimum performance under non-ideal conditions. The tests performed do offer some guidance as to expected mixing behavior for several common variables likely to be imposed by hardware constraints. Additionally, in this study it was found that for rows of orifices with opposite centerlines inline, mixing was similar for blockages up to 89 percent (previous crossflow mixing studies concerned with dilution zone configurations, blockages were typically less than 50 percent). Lower levels of unmixedness were obtained as a function of downstream location when axial injection length was minimized. Mixing may be enhanced if orifice centerlines of opposed rows are staggered, but blockage must be =50 percent in this configuration. Round hole and "square

  19. Method and apparatus for duct sealing using a clog-resistant insertable injector

    DOEpatents

    Wang, Duo; Modera, Mark P.

    2010-12-14

    A method for forming a duct access region through one side of a previously installed air duct, wherein the air duct has an air flow with an air flow direction by inserting an aerosol injector into a previously installed air duct through the access region. The aerosol injector includes a liquid tube having a liquid tube orifice for ejecting a liquid to be atomized; and a propellant cap. The method is accomplished by aligning the aerosol injector with the direction of air flow in the duct; activating an air flow within the duct; and spraying a sealant through the aerosol injector to seal the duct in the direction of the air flow.

  20. 14 CFR 23.1103 - Induction system ducts.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... duct and entering any other compartment of the airplane in which a hazard would be created by the entry... system must be suitably constructed of material that will not produce hazardous quantities of toxic...

  1. 14 CFR 23.1103 - Induction system ducts.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... duct and entering any other compartment of the airplane in which a hazard would be created by the entry... system must be suitably constructed of material that will not produce hazardous quantities of toxic...

  2. Flow field measurements in a 90 degree turning duct

    NASA Technical Reports Server (NTRS)

    Crawford, Roger A.; Peters, Carroll E.

    1985-01-01

    The objective of this investigation is the experimental evaluation of the influence of inlet turbulence intensity on secondary flow development in a turning duct. The existing 25.4 cm square turning duct (90) facility is being utilized to investigate of bulk turbulence levels on secondary flow development. The large scale duct flow facility allows detailed mean velocity and turbulence quantities to be measured at several streamwise planes in the curved duct. Non-intrusive laser velocimetry is being used to measure the mean and fluctuating components of velocity in all three orthogonal directions. To assure that the turbulence measurements are unbiased by particle lag and other effects, comparison hot wire data will be taken to validate the laser velocimetry system calibration.

  3. External linkage tie permits reduction in ducting system flange thickness

    NASA Technical Reports Server (NTRS)

    Pfleger, R. O.

    1966-01-01

    External linkage tie reduces flange thickness and increases seal efficiency in high pressure ducting and piping systems. The linkage transmits the pressure separating load to the tube wall behind the flange allowing the flange to support only the seal.

  4. Nasolacrimal Duct Mucocele: Case Report and Literature Review

    PubMed Central

    Britto, Fernanda Carneiro Corujeira de; Rosier, Vitor Veloso; Luz, Tovar Vicente; Verde, Raquel Crisóstomo Lima; Lima, Clara Mônica Figueiredo de; Lessa, Marcus Miranda

    2014-01-01

    Introduction Mucoceles are benign expansive cystic formations, composed of a mucus-secreting epithelium (respiratory or pseudostratified epithelium). Nasolacrimal mucocele occurs in a small proportion of children with nasolacrimal duct obstruction and is characterized by a cystic mass in the medial canthus with dilation of the nasolacrimal duct; although dacryocystoceles are rare in adults, they have been reported in patients with trachoma. Objective Discuss clinical aspects, diagnosis, and therapeutic management of mucocele of nasolacrimal duct based on literature review. Resumed Report The authors report a case of bilateral congenital nasolacrimal duct cysts in a 30-year-old man, identified as a tumor in the topography of both lacrimal sacs since birth without associated symptoms. The patient underwent successive surgical treatments, leading to recurrence of the tumor at the right side and recurrent local infections. Conclusion Endoscopic dacryocystorhinostomy has been increasingly used with good results and success rates similar to the external access. PMID:25992160

  5. Nasolacrimal duct mucocele: case report and literature review.

    PubMed

    Britto, Fernanda Carneiro Corujeira de; Rosier, Vitor Veloso; Luz, Tovar Vicente; Verde, Raquel Crisóstomo Lima; Lima, Clara Mônica Figueiredo de; Lessa, Marcus Miranda

    2015-01-01

    Introduction Mucoceles are benign expansive cystic formations, composed of a mucus-secreting epithelium (respiratory or pseudostratified epithelium). Nasolacrimal mucocele occurs in a small proportion of children with nasolacrimal duct obstruction and is characterized by a cystic mass in the medial canthus with dilation of the nasolacrimal duct; although dacryocystoceles are rare in adults, they have been reported in patients with trachoma. Objective Discuss clinical aspects, diagnosis, and therapeutic management of mucocele of nasolacrimal duct based on literature review. Resumed Report The authors report a case of bilateral congenital nasolacrimal duct cysts in a 30-year-old man, identified as a tumor in the topography of both lacrimal sacs since birth without associated symptoms. The patient underwent successive surgical treatments, leading to recurrence of the tumor at the right side and recurrent local infections. Conclusion Endoscopic dacryocystorhinostomy has been increasingly used with good results and success rates similar to the external access. PMID:25992160

  6. Diaphragm eliminates leakage in cryogenic fluid duct coupling

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Duct coupling with nickel steel diaphragm of low thermal expansivity is leakproof when used with cryogenic fluids. The diaphragm, located between the two flanges of the coupling, reduces axial shrinkage at the coupling flanges to a minimum.

  7. 54. DETAIL OF AIRCONDITIONING EXHAUST DUCTS ON NORTH FACE OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    54. DETAIL OF AIR-CONDITIONING EXHAUST DUCTS ON NORTH FACE OF ERECT UMBILICAL MAST - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  8. Numerical simulation of duct flow with fog droplets

    NASA Astrophysics Data System (ADS)

    Suryan, Abhilash; Lee, J. K.; Kim, D. S.; Kim, H. D.

    2010-12-01

    Evaporative cooling is a widely used air cooling technique. In this method, evaporation of a liquid in the surrounding air cools the air in contact with it. In the current investigation, numerical simulations are carried out to visualize the evaporation and dynamics of tiny water droplets of different diameters in a long air duct. The effect of initial droplet size on the temperature and relative humidity distribution of the air stream in the duct is investigated. Three different initial conditions of air are considered to verify the influence of ambient conditions. Droplet spray patterns are also analyzed to identify the suitable locations for the spray nozzles within the duct. The results obtained are displayed in a series of plots to provide a clear understanding of the evaporative cooling process as well as the droplet dynamics within the ducts.

  9. Materials for outlet ducts in wet FGD systems

    SciTech Connect

    Rosenberg, H.S.; Koch, G.H.; Kistler, C.W.; Beavers, J.A.; Meadows, M.L.; Stewart, D.A.; Dene, C.E.

    1985-01-01

    It was found that the major materials problems are occurring with outlet ducts and stack linings. Outlet ducts and stacks are critical components in that failures may require complete boiler shutdown and loss of generating capacity for lengthy periods due to the lack of standby components or bypass capability. Accordingly, EPRI funded a study by Battelle on the performance of candidate materials in the outlet ducts of FGD systems at two utility plants. Because of the impact of materials failures on FGD system reliability, EPRI is currently funding a study by Battelle on the causes of these failures. This study involves site visits for field evaluations of the failures, laboratory analyses of samples collected in the field, and analysis of the data to establish the causes of the failures. Information on outlet ducts is presented in this paper.

  10. 68. Credit FM. Detail showing operators. Note cooling duct (now ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    68. Credit FM. Detail showing operators. Note cooling duct (now removed), governor (now removed), hand-operated needle valve controls (now removed). - Battle Creek Hydroelectric System, Battle Creek & Tributaries, Red Bluff, Tehama County, CA

  11. Bile Duct Diseases - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Bile Duct Diseases URL of this page: https://medlineplus.gov/languages/bileductdiseases.html Other topics A-Z A B ...

  12. Ducting arrangement for cooling a gas turbine structure

    DOEpatents

    Lee, Ching-Pang; Morrison, Jay A.

    2015-07-21

    A ducting arrangement (10) for a can annular gas turbine engine, including: a duct (12, 14) disposed between a combustor (16) and a first row of turbine blades and defining a hot gas path (30) therein, the duct (12, 14) having raised geometric features (54) incorporated into an outer surface (80); and a flow sleeve (72) defining a cooling flow path (84) between an inner surface (78) of the flow sleeve (72) and the duct outer surface (80). After a cooling fluid (86) traverses a relatively upstream raised geometric feature (90), the inner surface (78) of the flow sleeve (72) is effective to direct the cooling fluid (86) toward a landing (94) separating the relatively upstream raised geometric feature (90) from a relatively downstream raised geometric feature (94).

  13. HVAC pipe/duct sizing using artificial neural networks

    SciTech Connect

    Yeh, S.J.D.; Wong, K.F.V.

    1995-12-31

    The main objective of this study is to demonstrate that artificial neural networks (ANN`s) serve as useful aids to Heating, Ventilating and Air-Conditioning (HVAC) system design. In the present work, the design process for sizing fluid systems in HVAC is simulated by using ANN`S. Four ANN`s have been constructed in a personal computer, one for air duct sizing and three for pipe sizing. The air duct network was trained to output the friction rate and duct size. The three pipe sizing neural networks product pressure drops and pipe diameters. By using the trained artificial neural networks, data can be obtained instantly with errors less than 3%. Thus, ANN`s have been shown to simplify traditional methods and procedures in HVAC pipe and air duct sizing.

  14. 12. SANDSORTING BUILDING, THIRD FLOOR, VIBRATING SCREENS ON RIGHT, DUCT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. SAND-SORTING BUILDING, THIRD FLOOR, VIBRATING SCREENS ON RIGHT, DUCT FOR DUST COLLECTION SYSTEM IN FOREGROUND, LOOKING NORTH - Mill "C" Complex, Sand-Sorting Building, South of Dee Bennet Road, near Illinois River, Ottawa, La Salle County, IL

  15. What Are the Risk Factors for Bile Duct Cancer?

    MedlinePlus

    ... the large intestine called ulcerative colitis. Bile duct stones , which are similar to, but much smaller than ... between ulcerative colitis and primary sclerosing cholangitis. Older age Older people are more likely than younger people ...

  16. Bile Duct Diseases - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Bile Duct Diseases URL of this page: https://www.nlm.nih.gov/medlineplus/languages/bileductdiseases.html Other topics A-Z A B ...

  17. High frequency sound attenuation in short flow ducts

    NASA Technical Reports Server (NTRS)

    Posey, J. W.

    1978-01-01

    A geometrical acoustics approach is proposed as a practical design tool for absorbent liners in such short flow ducts as may be found in turbofan engine nacelles. As an example, a detailed methodology is presented for three different types of sources in a parallel plate duct containing uniform ambient flow. A plane wave whose wavefronts are not normal to the duct walls, an arbitrarily located point source, and a spatially harmonic line source are each considered. Optimal wall admittance distributions are found, and it is shown how to estimate the insertion loss for any admittance distribution. The extension of the methodology to realistic source distributions in variable area cylindrical or annular ducts containing arbitrary flow is shown to be conceptually straightforward and computationally practical on a vector-hardware digital computer.

  18. DUCT RETROFIT STRATEGY TO COMPLEMENT A MODULATING FURNACE.

    SciTech Connect

    ANDREWS,J.W.

    2002-10-02

    Some recent work (Walker 2001, Andrews 2002) has indicated that installing a modulating furnace in a conventional duct system may, in many cases, result in a significant degradation in thermal distribution efficiency. The fundamental mechanism was pointed out nearly two decades ago (Andrews and Krajewski 1985). The problem occurs in duct systems that are less-than-perfectly insulated (e.g., R-4 duct wrap) and are located outside the conditioned space. It stems from the fact that when the airflow rate is reduced, as it will be when the modulating furnace reduces its heat output rate, the supply air will have a longer residence time in the ducts and will therefore lose a greater percentage of its heat by conduction than it did at the higher airflow rate. The impact of duct leakage, on the other hand, is not expected to change very much under furnace modulation. The pressures in the duct system will be reduced when the airflow rate is reduced, thus reducing the leakage per unit time. This is balanced by the fact that the operating time will increase in order to meet the same heating load as with the conventional furnace operating at higher output and airflow rates. The balance would be exact if the exponent in the pressure vs. airflow equation were the same as that in the pressure vs. duct leakage equation. Since the pressure-airflow exponent is usually {approx}0.5 and the pressure-leakage exponent is usually {approx}0.6, the leakage loss as a fraction of the load should be slightly lower for the modulating furnace. The difference, however, is expected to be small, determined as it is by a function with an exponent equal to the difference between the above two exponents, or {approx}0.1. The negative impact of increased thermal conduction losses from the duct system may be partially offset by improved efficiency of the modulating furnace itself. Also, the modulating furnace will cycle on and off less often than a single-capacity model, and this may add a small amount

  19. Compact Buried Ducts in a Hot-Humid Climate House

    SciTech Connect

    Mallay, D.

    2016-01-01

    A system of compact, buried ducts provides a high-performance and cost-effective solution for delivering conditioned air throughout the building. This report outlines research activities that are expected to facilitate adoption of compact buried duct systems by builders. The results of this research would be scalable to many new house designs in most climates and markets, leading to wider industry acceptance and building code and energy program approval.

  20. Beam loss by collimation in a neutralizer duct

    SciTech Connect

    Hamilton, G.W.; Willmann, P.A.

    1980-04-03

    Beam fractions lost by collimation in a neutralizer duct are computed in x-x' phase space by using three examples of slab beam distributions under a broad range of duct dimensions, beam half-widths, and beam divergences. The results can be used to design compact neutralizers and to specify beam requirements. The computer code ILOST can be used under a broad range of beam conditions to compute the fraction lost by collimation.

  1. Acoustic attenuation analysis program for ducts with mean flow

    NASA Technical Reports Server (NTRS)

    Kunze, R. K., Jr.

    1972-01-01

    A computerized acoustic attenuation prediction procedure has been developed to evaluate acoustically lined ducts for various geometric and environmental parameters. The analysis procedure is based on solutions to the acoustic wave equation, assuming uniform airflow on a duct cross section, combined with appropriate mathematical lining impedance models. The impedance models included in the analysis procedure are representative of either perforated sheet or porous polyimide impregnated fiberglass facing sheet coupled with a cellular backing space. Advantages and limitations of the analysis procedure are reviewed.

  2. Acoustic propagation in partially choked converging-diverging ducts

    NASA Astrophysics Data System (ADS)

    Kelly, J. J.; Nayfeh, A. H.; Watson, L. T.

    1982-04-01

    A computer model based on the wave-envelope technique is used to study acoustic propagation in converging-diverging hard walled and lined circular ducts carrying near sonic mean flows. The influences of the liner admittance, boundary layer thickness, spinning mode number, and mean Mach number are considered. The numerical results indicate that the diverging portion of the duct can have a strong reflective effect for partially choked flows.

  3. Tubulopapillary adenoma of the common bile duct presenting with jaundice

    PubMed Central

    Yusif-zade, Kenan; Musayev, Jamal; Yeler, Maryam

    2016-01-01

    In this report, an adult patient with tubulopapillary adenoma of the common bile duct that manifested with jaundice is presented. Diagnostic challenges were analyzed. Although adenomas of the common bile duct are rare, they should be kept in mind in the differentiation of lesions of this region. It should be remembered that these lesions radiologically could mimic carcinoma and choledocholithiasis. Endoscopic resection should be considered as the primary method for treatment. Histopathology is the gold standard in diagnosis. PMID:27528819

  4. AIR DUCTS STAND NEXT TO (AND OUTSIDE OF) REACTOR CABINET ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    AIR DUCTS STAND NEXT TO (AND OUTSIDE OF) REACTOR CABINET AT THE SOUTHWEST AND NORTHEAST CORNERS OF THE REACTOR'S THERMAL SHIELD. THEY WILL BE ENVELOPED IN BIOLOGICAL CONCRETE SHIELD. IN THE SUB-BASEMENT, THE TWO DUCTS WILL JOIN TOGETHER AND EXIT THE BUILDING TO THE FAN HOUSE. CAMERA FACING NORTH. INL NEGATIVE NO. 1625. Unknown Photographer, 3/6/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  5. Numerical techniques in linear duct acoustics - A status report

    NASA Technical Reports Server (NTRS)

    Baumeister, K. J.

    1980-01-01

    A review is presented covering both finite difference and finite element analysis of small amplitude (linear) sound propagation in straight and variable area ducts with flow, as might be found in a typical turbojet engine duct, muffer, or industrial ventilation system. Both 'steady' state and transient theories are discussed. Emphasis is placed on the advantages and limitations associated with the various numerical techniques. Examples of practical problems are given for which the numerical techniques have been applied.

  6. Persistent Mullerian Duct Syndrome with Transverse Testicular Ectopia

    PubMed Central

    Kumar, P. Naresh; Venugopala, Kandgal

    2015-01-01

    Persistent Mullerian duct syndrome (PMDS) is a rare form of male pseudohermaphroditism characterized by the presence of Mullerian duct structures in a normal male with 46, XY karyotype. Transverse testicular ectopia (TTE) is rare form of testicular ectopia in which two testes are located on one inguinal side. The opposite scrotum is empty. PMDS with TTE is rare. We report a case of PMDS with TTE discovered during surgery for a right inguinal hernia in a 25-year-old male. PMID:27512542

  7. Efficiency of shock wave attenuation in ducts by various methods

    NASA Astrophysics Data System (ADS)

    Frolov, S. M.

    1993-02-01

    Different methods of shock wave attenuation in ducts are compared in terms of efficiency. The methods investigated include expansion of the duct cross section, the use of perforated side walls, and the use of porous screens and screen cascades. The attentuation of air shock waves is estimated by using a unified approach which provides satisfactory agreement with experimental data. Based on the results of the study, a nomogram is plotted which can be used for practical calculations.

  8. Lidar description of the evaporative duct in ocean environments

    NASA Astrophysics Data System (ADS)

    Willitsford, Adam; Philbrick, C. R.

    2005-08-01

    The description of radar propagation in the presence of the evaporation duct has proven to be a difficult problem in both littoral and open ocean environments. To properly characterize the propagation of a radar beam at low elevation angles, the evaporation duct must be located and scattering properties quantified. The two key elements defining an evaporation duct are the gradients in density and specific humidity. The gradients of the neutral density are determined from the rotational Raman temperature profile. The profile of water vapor is measured directly from the vibrational Raman scattered returns. High spatial resolution and high temporal resolution measurements of water vapor and temperature are required to accurately describe the evaporation duct. Raman lidar techniques can provide these measurements continuously with high accuracy and high resolution so the development of the evaporation duct can be studied. A detailed simulation of a Raman lidar has been developed and applied to a near horizontal path, to examine the expected accuracy for high vertical resolution profiles. The simulation also allows various atmospheric scenarios to be investigated and analyzed. The evaporation duct is an atmospheric phenomenon that causes radar propagation to remain trapped in the surface layer. The duct can be thought of as a waveguide that bends and reflects the radar beam along a path effectively trapping it and guiding it over long distances. This is a major problem for radar propagation paths in both littoral and open ocean environments. Moreover, ducting skews details of radar returns such that radar objects are hidden, or are detected at unexpected distances, or may appear with apparent cross-sections and speeds much different than their actual values.

  9. Better Duct Systems for Home Heating and Cooling

    SciTech Connect

    Not Available

    2004-11-01

    Duct systems used in forced-air space-conditioning systems are a vital element in home energy efficiency. How well a system works makes a big difference in the cost and the effectiveness of heating and cooling a home. At the same time, a duct system that is poorly designed or maintained can have a detrimental effect on the health of the people who live in the house, through the unintended distribution of indoor air pollution.

  10. Benign disease of the common bile duct.

    PubMed

    Saxena, R; Pradeep, R; Chander, J; Kumar, P; Wig, J D; Yadav, R V; Kaushik, S P

    1988-08-01

    The incidence of common bile duct (CBD) pathology in a group of patients with benign biliary disease (n = 505) was found to be 23.2 per cent. The spectrum included 111 patients (90.2 per cent) with CBD stones, 37 of whom (33.3 per cent) had no symptoms or findings pre-operatively indicating CBD involvement. Five patients had papillary stenosis, three had postoperative CBD strictures, one had a choledochal cyst and one had an external biliary fistula. Of the 100 CBDs measuring more than 10 mm in diameter, 90 harboured calculi. In the remaining 23 CBDs measuring less than 10 mm, calculi were present in 21. The presence of CBD calculi was demonstrated by intra-operative cholangiography in 49 patients. In the remaining patients (n = 74), the diagnosis of CBD pathology was made either by percutaneous transhepatic cholangiography, endoscopic retrograde cholangio-pancreatography, T-tube cholangiography or peroperative palpation. The surgical procedures performed included choledochotomy and T-tube drainage (n = 74), transduodenal sphincteroplasty (n = 27) and choledochoduodenostomy (n = 18). The overall mortality and morbidity of CBD exploration was 3.3 per cent and 24.4 per cent respectively, which was significantly greater than that for cholecystectomy alone (0.3 per cent and 8.6 per cent respectively). Transduodenal sphincteroplasty carried a much higher mortality (11 per cent) and morbidity (52 per cent) when compared with other procedures. PMID:3167536

  11. Sarcoidosis of the liver and bile ducts.

    PubMed

    Ishak, K G

    1998-05-01

    In sarcoidosis, granulomas are frequently present in multiple organs, including the liver. Typically, epithelioid granulomas (noncaseating) are scattered throughout the liver, but confluent granulomas can be present in cases with severe hepatic involvement. The characteristic inclusions in giant cells (for example, Schaumann bodies and asteroid bodies) are not seen in all cases and are not pathognomonic. The granulomas of sarcoidosis may heal without a trace, but confluent granulomas can result in extensive, irregular scarring. Occlusion of intrahepatic portal vein branches by the granulomatous inflammation probably accounts for the development of portal hypertension in some cases. A granulomatous cholangitis leading to ductopenia seems to be the underlying pathogenetic mechanism of the chronic cholestatic syndrome of sarcoidosis. Recognition of this syndrome is important in the differential diagnosis of other chronic cholestatic diseases, such as primary biliary cirrhosis or primary sclerosing cholangitis. Other rare complications of sarcoidosis are the Budd-Chiari syndrome and obstructive jaundice attributable to hepatic hilar lymphadenopathy or strictures of the bile ducts. PMID:9581591

  12. Film condensation in a horizontal rectangular duct

    NASA Technical Reports Server (NTRS)

    Lu, Qing; Suryanarayana, N. V.

    1992-01-01

    Condensation heat transfer in an annular flow regime with and without interfacial waves was experimentally investigated. The study included measurements of heat transfer rate with condensation of vapor flowing inside a horizontal rectangular duct and experiments on the initiation of interfacial waves in condensation, and adiabatic air-liquid flow. An analytical model for the condensation was developed to predict condensate film thickness and heat transfer coefficients. Some conclusions drawn from the study are that the condensate film thickness was very thin (less than 0.6 mm). The average heat transfer coefficient increased with increasing the inlet vapor velocity. The local heat transfer coefficient decreased with the axial distance of the condensing surface, with the largest change at the leading edge of the test section. The interfacial shear stress, which consisted of the momentum shear stress and the adiabatic shear stress, appeared to have a significant effect on the heat transfer coefficients. In the experiment, the condensate flow along the condensing surface experienced a smooth flow, a two-dimensional wavy flow, and a three-dimensional wavy flow. In the condensation experiment, the local wave length decreased with the axial distance of the condensing surface and the average wave length decreased with increasing inlet vapor velocity, while the wave speed increased with increasing vapor velocity. The heat transfer measurements are reliable. And, the ultrasonic technique was effective for measuring the condensate film thickness when the surface was smooth or had waves of small amplitude.

  13. Improving Diffusing S-duct Performance by Secondary Flow Control

    NASA Technical Reports Server (NTRS)

    Reichert, Bruce A.; Wendt, Bruce J.

    1994-01-01

    The objective of this research was to study ways to reduce inlet flow distortion (i.e., total pressure nonuniformity) and improve total pressure recovery in a diffusing S-duct. This was accomplished by controlling the development of secondary flows within the duct through the use of tapered-fin type vortex generators. Reported are results for the bare duct and seven different configurations of vortex generators. Data presented for each configuration include surface static pressure, surface flow visualization, and exit plane total pressure and transverse velocity. The performance of each configuration was assessed by calculating total pressure recovery and inlet distortion descriptors from the data and comparing them to the values for the bare duct. The best configuration tested reduced distortion (as measured by the DC(45) and DC(90) descriptors) by more than 50 percent while improving total pressure recovery by 0.5 percent. These results should provide valuable guidance in designing vortex generator installations in ducts and for assessing the accuracy of computational fluid dynamics (CFD) methods to calculate duct flows with installed vortex generators.

  14. [Thoracic duct valves in man and albino rat].

    PubMed

    Petrenko, V M; Kruglov, S V

    2004-01-01

    The aim of this research was to determine the number, structure and position of valves along the whole length of thoracic duct in man and albino rat. The study was performed using the material obtained from 30 human corpses of men and women aged 17 to 60 years with no history of cardiovascular pathology and from 60 outbred albino rats of both sexes aged 5 to 12 months. Material was fixed in 10% neutral formalin. Anterior wall of thoracic duct was longitudinally dissected. Thoracic duct of 30 rats was stained with gallocyanin-chrome alum, in the remaining animals it was studied after its injection with blue Gerota's mass. In most cases, the valves consisted of two semilunar cusps. Thoracic duct was found to contain on the average 14.7+/-0.2 valves in man and 11.9+/-0.2 valves in rat. Most of all valves were found in the upper (anterior) 1/3 of the thoracic duct, least--in its middle part. This seems to be determined by anatomo-topographic features of the different parts of thoracic duct. PMID:15839250

  15. WAVE PROPAGATION in the HOT DUCT of VHTR

    SciTech Connect

    Richard Schultz; Jim C. P. Liou

    2013-07-01

    In VHTR, helium from the reactor vessel is conveyed to a power conversion unit through a hot duct. In a hypothesized Depressurized Conduction Cooldown event where a rupture of the hot duct occurs, pressure waves will be initiated and reverberate in the hot duct. A numerical model is developed to quantify the transients and the helium mass flux through the rupture for such events. The flow path of the helium forms a closed loop but only the hot duct is modeled in this study. The lower plum of the reactor vessel and the steam generator are treated as specified pressure and/or temperature boundary to the hot duct. The model is based on the conservation principles of mass, momentum and energy, and on the equations of state for helium. The numerical solution is based on the method of characteristics with specified time intervals with a predictor and corrector algorithm. The rupture sub-model gives reasonable results. Transients induced by ruptures with break area equaling 20%, 10%, and 5% of the duct cross-sectional area are described.

  16. Energy efficient engine: Turbine transition duct model technology report

    NASA Technical Reports Server (NTRS)

    Leach, K.; Thurlin, R.

    1982-01-01

    The Low-Pressure Turbine Transition Duct Model Technology Program was directed toward substantiating the aerodynamic definition of a turbine transition duct for the Energy Efficient Engine. This effort was successful in demonstrating an aerodynamically viable compact duct geometry and the performance benefits associated with a low camber low-pressure turbine inlet guide vane. The transition duct design for the flight propulsion system was tested and the pressure loss goal of 0.7 percent was verified. Also, strut fairing pressure distributions, as well as wall pressure coefficients, were in close agreement with analytical predictions. Duct modifications for the integrated core/low spool were also evaluated. The total pressure loss was 1.59 percent. Although the increase in exit area in this design produced higher wall loadings, reflecting a more aggressive aerodynamic design, pressure profiles showed no evidence of flow separation. Overall, the results acquired have provided pertinent design and diagnostic information for the design of a turbine transition duct for both the flight propulsion system and the integrated core/low spool.

  17. Remote sensing of evaporation ducts for Naval warfare

    NASA Astrophysics Data System (ADS)

    Geernaert, G. L.

    1989-11-01

    Areas critical to naval operations are the prediction and application of atmospheric refractivity gradients. This report describes the use of the evaporation duct over the ocean and a plan for obtaining information about the evaporation duct by space-borne sensors. There has been little research on the theory and modeling of lower atmospheric refractivity, particularly evaporation ducts over a nonhomogeneous ocean over the past five decades. Much is known about surface layer similarity theory and propagation model techniques, but little attention has been placed on the spatial variabilities in the turbulent propagation medium (such as the atmospheric surface layer) in regions of strategic Navy interest. These regions include the coastal shelf, Gulf Stream, marginal ice zone, and those places where sharp sea surface temperature fronts exist. For tomorrow's Navy, using remote sensing techniques to infer evaporative and tropospheric ducts are a requirement. Although research efforts on ducts must couple the tropospheric and surface layer components, this report summarizes the state of the art for the evaporative duct and assess the potential of new and future results on improving next generation naval warfare capabilities.

  18. A New Model of the Oceanic Evaporation Duct.

    NASA Astrophysics Data System (ADS)

    Babin, Steven M.; Young, George S.; Carton, James A.

    1997-03-01

    Failure to consider anomalous propagation of microwave radiation in the troposphere may result in erroneous meteorological radar measurements. The most commonly occurring anomalous propagation phenomenon over the ocean is the evaporation duct. The height of this duct is dependent on atmospheric variables and is a major input to microwave propagation prediction models. This evaporation duct height is determined from an evaporation duct model using bulk measurements. Two current evaporation duct models in widespread operational use are examined. We propose and test a new model that addresses deficiencies in these two models. The new model uses recently refined bulk similarity expressions developed for the determination of the ocean surface energy budget in the Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment. Comparison of these models is made using data collected from a boat off Wallops Island, Virginia, during a range of seasons and weather conditions and from the tidal Potomac River during June and August. Independent evaporation duct height determinations are made using profile measurements from the same boat and are corroborated with fade measurements made with a nearby microwave link whenever possible. The proposed model performs better than the other (operational) models for the cases examined and has advantages of internal consistency.

  19. Flow control in a diffusing S-Duct

    NASA Technical Reports Server (NTRS)

    Vakili, A. D.; Wu, J. M.; Liver, P.; Bhat, M. K.

    1985-01-01

    Accurate measurements have been made of secondary flow in a 1.51 area ratio diffusing 30 deg - 30 deg S-Duct with circulair cross section. Turbulent flow was entering the duct at Mach number of 0.6, the boundary layer thickness at the duct entrance was ten percent of the duct inlet diameter. Through measurements made, local flow velocity vector as well as static and total pressures mapping of the flow at several stations were obtained. Strong secondary flow was measured in the first bend which continued into the second bend with new vorticity produced in there in the opposite direction. Surface oil flow visualization and wall pressures indicated a region of separated flow starting at theta approximately equal to 22 deg on the inside of the first bend up to theta approximately equal to 44 deg on the outside of the second bend. The flow separated in 'cyclone' form and never reattached in the duct. As a result of the secondary flow and the flow separation, significant total pressure distortion was observed at the exit of the duct. Using flow control devices the separation was eliminated while the exit distortion was improved.

  20. Measure Guideline: Summary of Interior Ducts in New Construction, Including an Efficient, Affordable Method to Install Fur-Down Interior Ducts

    SciTech Connect

    Beal, D.; McIlvaine, J.; Fonorow, K.; Martin, E.

    2011-11-01

    This document illustrates guidelines for the efficient installation of interior duct systems in new housing, including the fur-up chase method, the fur-down chase method, and interior ducts positioned in sealed attics or sealed crawl spaces.

  1. An evaluation of methodology for seismic qualification of equipment, cable trays, and ducts in ALWR plants by use of experience data

    SciTech Connect

    Bandyopadhyay, K.K.; Kana, D.D.; Kennedy, R.P.; Schiff, A.J.

    1997-07-01

    Advanced Reactor Corporation (ARC) has developed a methodology for seismic qualification of equipment, cable trays and ducts in Advanced Light Water Reactor plants. A Panel (members of which acted as individuals) supported by the Office of Nuclear Regulatory Research of the Nuclear Regulatory Commission has evaluated this methodology. The review approach and observations are included in this report. In general, the Panel supports the ARC methodology with some exceptions and provides recommendations for further improvements. 26 refs., 10 figs., 1 tab.

  2. Endoscopic bile duct and/or pancreatic duct cannulation technique for patients with surgically altered gastrointestinal anatomy.

    PubMed

    Okabe, Yoshinobu; Ishida, Yusuke; Kuraoka, Kei; Ushijima, Tomoyuki; Tsuruta, Osamu

    2014-04-01

    There are two major hurdles to carrying out endoscopic retrograde cholangiopancreatography (ERCP) in patients with altered gastrointestinal anatomy (Billroth II gastrectomy [B-II], Roux-en-Y anastomosis [R-Y] etc.), post-pancreatoduodenectomy or post-choledochojejunostomy. These are: (i) the endoscopic approach to the afferent loop, blind end, and the site of bilio-pancreatic anastomosis; and (ii) bile duct and/or pancreatic duct cannulation. Balloon-assisted enteroscopy (BAE) became available in recent years and is now being actively used to overcome the first hurdle and, at least, the success rate has improved. However, room for improvement still remains in regards to the second hurdle (i.e. the success rate of cannulation of the bile duct and/or pancreatic duct), and there has been a desire for the development of dedicated devices (ERCP catheters, hoods etc.) and for improvement in the functionality of the enteroscopes etc. In the present review, we explain the basic procedure for bile duct and/or pancreatic duct cannulation with conventional endoscopes and BAE, and modifications of the basic procedure. PMID:24750161

  3. Estimating evaporation duct heights from radar sea echo

    NASA Astrophysics Data System (ADS)

    Rogers, L. Ted; Hattan, Claude P.; Stapleton, Janet K.

    2000-07-01

    The evaporation duct is a downward refracting layer that results from the rapid decrease in humidity with respect to altitude occurring in the atmospheric surface layer above bodies of water. The evaporation duct affects radar detection ranges at frequencies of approximately 1 GHz and above. Models based on Monin-Obukhov similarity theory are usually used to calculate evaporation duct refractivity profiles from bulk measurements of air temperature, humidity, wind speed, and the sea surface temperature. Modeling results by Pappert et al. [1992] indicated that the falloff of radar sea echo as a function of range was an increasing function of the evaporation duct height. On the basis of those results, the authors proposed inferring the evaporation duct height by a slope fit to modeled clutter power, a nonlinear least squares inversion procedure. Data for testing the inversion procedure were obtained using the S band Space Range Radar at Wallops Island, Virginia. Evaporation duct heights were inferred from the radar data on the basis of the assumption of a range-independent evaporation duct height and sea clutter radar cross section (σ°). Validation data consist of buoy and boat in situ bulk measurements. The result of comparing the radar-inferred evaporation duct heights and those calculated from bulk measurements indicates that the radar-inferred duct heights are strongly correlated with those from the in situ measurements, but there is some uncertainty as to whether they are biased or unbiased. That uncertainty arises from the assumed dependence of σ° on the grazing angle ψ. That dependence is currently a matter of debate in the open literature, with the lower and upper ends of modeling results being σ° ∝ ψ0; and σ° ∝ ψ4, respectively. We show results for both dependencies and note that the σ° ∝ ψ0; provides the best agreement with our measurements. It should be noted that inferring the evaporation duct height from radar sea echo is a problem

  4. Numerical investigation of tip clearance effects on the performance of ducted propeller

    NASA Astrophysics Data System (ADS)

    Yongle, Ding; Baowei, Song; Peng, Wang

    2015-09-01

    Tip clearance loss is a limitation of the improvement of turbomachine performance. Previous studies show the Tip clearance loss is generated by the leakage flow through the tip clearance, and is roughly linearly proportional to the gap size. This study investigates the tip clearance effects on the performance of ducted propeller. The investigation was carried out by solving the Navier-Stokes equations with the commercial Computational Fluid Dynamic (CFD) code CFX14.5. These simulations were carried out to determine the underlying mechanisms of the tip clearance effects. The calculations were performed at three different chosen advance ratios. Simulation results showed that the tip loss slope was not linearly at high advance due to the reversed pressure at the leading edge. Three type of vortical structures were observed in the tip clearance at different clearance size.

  5. Chlamydia muridarum Induction of Glandular Duct Dilation in Mice

    PubMed Central

    Sun, Xin; Yang, Zhangsheng; Zhang, Hongbo; Dai, Jin; Chen, Jianlin; Tang, Lingli; Rippentrop, Sheena; Xue, Min

    2015-01-01

    Although Chlamydia-induced hydrosalpinx in women and mice has been used as a surrogate marker for tubal infertility, the medical relevance of nontubal pathologies, such as uterine horn dilation, developed in mice following chlamydial infection remains unclear. We now report that the uterine horn dilation correlates with glandular duct dilation detected microscopically following Chlamydia muridarum infection. The dilated glandular ducts pushed the uterine horn lumen to closure or dilation and even broke through the myometrium to develop extrusion outside the uterine horn. The severity scores of uterine horn dilation observed macroscopically correlated well with the number of cross sections of the dilated glandular ducts counted under microscopy. Chlamydial infection was detected in the glandular epithelial cells, potentially leading to inflammation and dilation of the glandular ducts. Direct delivery of C. muridarum into the mouse uterus increased both uterine horn/glandular duct dilation and hydrosalpinx. However, the chlamydial plasmid, which is essential for the induction of hydrosalpinx, was not required for the induction of uterine horn/glandular duct dilation. Screening 12 strains of mice for uterine horn dilation following C. muridarum infection revealed that B10.D2, C57BL/10J, and C57BL/6J mice were most susceptible, followed by BALB/cJ and A/J mice. Deficiency in host genes involved in immune responses failed to significantly alter the C. muridarum induction of uterine horn dilation. Nevertheless, the chlamydial induction of uterine horn/glandular duct dilation may be used to evaluate plasmid-independent pathogenicity of Chlamydia in susceptible mice. PMID:25824829

  6. ATP release, generation and hydrolysis in exocrine pancreatic duct cells.

    PubMed

    Kowal, J M; Yegutkin, G G; Novak, I

    2015-12-01

    Extracellular adenosine triphosphate (ATP) regulates pancreatic duct function via P2Y and P2X receptors. It is well known that ATP is released from upstream pancreatic acinar cells. The ATP homeostasis in pancreatic ducts, which secrete bicarbonate-rich fluid, has not yet been examined. First, our aim was to reveal whether pancreatic duct cells release ATP locally and whether they enzymatically modify extracellular nucleotides/sides. Second, we wished to explore which physiological and pathophysiological factors may be important in these processes. Using a human pancreatic duct cell line, Capan-1, and online luminescence measurement, we detected fast ATP release in response to pH changes, bile acid, mechanical stress and hypo-osmotic stress. ATP release following hypo-osmotic stress was sensitive to drugs affecting exocytosis, pannexin-1, connexins, maxi-anion channels and transient receptor potential cation channel subfamily V member 4 (TRPV4) channels, and corresponding transcripts were expressed in duct cells. Direct stimulation of intracellular Ca(2+) and cAMP signalling and ethanol application had negligible effects on ATP release. The released ATP was sequentially dephosphorylated through ecto-nucleoside triphosphate diphosphohydrolase (NTPDase2) and ecto-5'-nucleotidase/CD73 reactions, with respective generation of adenosine diphosphate (ADP) and adenosine and their maintenance in the extracellular medium at basal levels. In addition, Capan-1 cells express counteracting adenylate kinase (AK1) and nucleoside diphosphate kinase (NDPK) enzymes (NME1, 2), which contribute to metabolism and regeneration of extracellular ATP and other nucleotides (ADP, uridine diphosphate (UDP) and uridine triphosphate (UTP)). In conclusion, we illustrate a complex regulation of extracellular purine homeostasis in a pancreatic duct cell model involving: ATP release by several mechanisms and subsequent nucleotide breakdown and ATP regeneration via counteracting nucleotide

  7. Intestinal disaccharidase activity following pancreatic duct occlusion in the rat.

    PubMed

    Hauer-Jensen, M; Christensen, K; Wilson, H D; Schedl, H P

    1987-01-01

    The influence of pancreatic secretions on growth and brush-border enzyme activity, throughout the entire small intestine, was examined in the rat. Pancreatic secretions were excluded from the gut lumen by stapling the pancreatic ducts, without interruption of bile flow. The entire small intestine was studied as four segments; the duodenum and three distal segments of equal length. Weight of intestine and mucosa, and mucosal sucrase, isomaltase, lactase, and alkaline phosphatase activity were measured 10-15 days following pancreatic duct occlusion, or sham-operation. The duodenum of pancreatic duct-occluded animals exhibited significant hypertrophy. In general, specific and total disaccharidase activities were greater in duct-occluded animals than in controls throughout the intestine. The increase was more pronounced in distal than in proximal segments. The sucrase/isomaltase ratio was significantly greater in pancreatic duct-occluded animals than in controls in the two distal segments. Alkaline phosphatase activity was not affected by pancreatic duct occlusion. The greater relative increase of disaccharidase activities and sucrase/isomaltase activity ratios in the distal segments of duct-occluded animals, indicates a more important regulatory role of pancreatic enzymes in the distal small intestine. It is concluded that regulation of intestinal brush-border enzyme activity by pancreatic secretion is selective for enzyme and site as follows: disaccharidases, but not alkaline phosphatase, are regulated; the sucrase subunit of the sucrase/isomaltase complex is most sensitive to regulation, while lactase is least sensitive; and the regulatory effect on disaccharidases is greater in distal than in proximal intestine. PMID:3114740

  8. Mechanical properties of the porcine bile duct wall

    PubMed Central

    Duch, Birgitte U; Andersen, Helle; Gregersen, Hans

    2004-01-01

    Background and Aim The function of the common bile duct is to transport bile from the liver and the gall bladder to the duodenum. Since the bile duct is a distensible tube consisting mainly of connective tissue, it is important to obtain data on the passive mechanical wall properties. The aims of this study were to study morphometric and biomechanical wall properties during distension of the bile duct. Methods Ten normal porcine common bile ducts were examined in vitro. A computer-controlled volume ramp infusion system with concomitant pressure recordings was constructed. A video camera provided simultaneous measurement of outer dimensions of the common bile duct. Wall stresses and strains were computed. Results The common bile duct length increased by 25% from 24.4 ± 1.8 mm at zero pressure to 30.5 ± 2.0 mm at 5 kPa (p < 0.01). The diameter increased less than 10% in the same pressure range from 8.6 ± 0.4 mm to 9.3 ± 0.4 mm (p < 0.01). The stress-strain relations showed an exponential behavior with a good fit to the equation: σ = α . (exp(βε) - 1). The circumferential stress-strain curve was shifted to the left when compared to the longitudinal stress-strain curve, i.e. the linear constants (α values) were different (p < 0.01) whereas the exponential constants (β values) did not differ (p > 0.5). Conclusion The porcine bile duct exhibited nonlinear anisotropic mechanical properties. PMID:15260881

  9. Parametric study of electromagnetic waves propagating in absorbing curved S ducts

    NASA Technical Reports Server (NTRS)

    Baumeister, Kenneth J.

    1989-01-01

    A finite-element Galerkin formulation has been developed to study attenuation of transverse magnetic (TM) waves propagating in two-dimensional S-curved ducts with absorbing walls. In the frequency range where the duct diameter and electromagnetic wave length are nearly equal, the effect of duct length, curvature (duct offset), and absorber wall thickness was examined. For a given offset in the curved duct, the length of the S-duct was found to significantly affect both the absorptive and reflective characteristics of the duct. For a straight and a curved duct with perfect electric conductor terminations, power attenuation contours were examined to determine electromagnetic wall properties associated with maximum input signal absorption. Offset of the S-duct was found to significantly affect the value of the wall permittivity associated with the optimal attenuation of the incident electromagnetic wave.

  10. Validation of the Predicted Circumferential and Radial Mode Sound Power Levels in the Inlet and Exhaust Ducts of a Fan Ingesting Distorted Inflow

    NASA Technical Reports Server (NTRS)

    Koch, L. Danielle

    2012-01-01

    Fan inflow distortion tone noise has been studied computationally and experimentally. Data from two experiments in the NASA Glenn Advanced Noise Control Fan rig have been used to validate acoustic predictions. The inflow to the fan was distorted by cylindrical rods inserted radially into the inlet duct one rotor chord length upstream of the fan. The rods were arranged in both symmetric and asymmetric circumferential patterns. In-duct and farfield sound pressure level measurements were recorded. It was discovered that for positive circumferential modes, measured circumferential mode sound power levels in the exhaust duct were greater than those in the inlet duct and for negative circumferential modes, measured total circumferential mode sound power levels in the exhaust were less than those in the inlet. Predicted trends in overall sound power level were proven to be useful in identifying circumferentially asymmetric distortion patterns that reduce overall inlet distortion tone noise, as compared to symmetric arrangements of rods. Detailed comparisons between the measured and predicted radial mode sound power in the inlet and exhaust duct indicate limitations of the theory.

  11. Advances in Therapeutic Cholangioscopy

    PubMed Central

    Moura, Renata Nobre; de Moura, Eduardo Guimarães Hourneaux

    2016-01-01

    Nowadays, cholangioscopy is an established modality in diagnostic and treatment of pancreaticobiliary diseases. The more widespread use and the recent development of new technologies and accessories had renewed the interest of endoscopic visualization of the biliary tract, increasing the range of indications and therapeutic procedures, such as diagnostic of indeterminate biliary strictures, lithotripsy of difficult bile duct stones, ablative techniques for intraductal malignancies, removal of foreign bodies and gallbladder drainage. These endoscopic interventions will probably be the last frontier in the near future. This paper presents the new advances in therapeutic cholangioscopy, focusing on the current clinical applications and on research areas. PMID:27403156

  12. Propagation of premixed laminar flames in 3D narrow open ducts using RBF-generated finite differences

    NASA Astrophysics Data System (ADS)

    Bayona, Victor; Kindelan, Manuel

    2013-10-01

    Laminar flame propagation is an important problem in combustion modelling for which great advances have been achieved both in its theoretical understanding and in the numerical solution of the governing equations in 2D and 3D. Most of these numerical simulations use finite difference techniques on simple geometries (channels, ducts, ...) with equispaced nodes. The objective of this work is to explore the applicability of the radial basis function generated finite difference (RBF-FD) method to laminar flame propagation modelling. This method is specially well suited for the solution of problems with complex geometries and irregular boundaries. Another important advantage is that the method is independent of the dimension of the problem and, therefore, it is very easy to apply in 3D problems with complex geometries. In this work we use the RBF-FD method to compute 2D and 3D numerical results that simulate premixed laminar flames with different Lewis numbers propagating in open ducts.

  13. Heterogeneity Between Ducts of the Same Nuclear Grade Involved by Duct Carcinoma In Situ (DCIS) of the Breast

    PubMed Central

    Miller, Naomi A.; Chapman, Judith-Anne W.; Qian, Jin; Christens-Barry, William A.; Fu, Yuejiao; Yuan, Yan; Lickley, H. Lavina A.; Axelrod, David E.

    2010-01-01

    Purpose Nuclear grade of breast DCIS is considered during patient management decision-making although it may have only a modest prognostic association with therapeutic outcome. We hypothesized that visual inspection may miss substantive differences in nuclei classified as having the same nuclear grade. To test this hypothesis, we measured subvisual nuclear features by quantitative image cytometry for nuclei with the same grade, and tested for statistical differences in these features. Experimental design and statistical analysis Thirty-nine nuclear digital image features of about 100 nuclei were measured in digital images of H&E stained slides of 81 breast biopsy specimens. One field with at least 5 ducts was evaluated for each patient. We compared features of nuclei with the same grade in multiple ducts of the same patient with ANOVA (or Welch test), and compared features of nuclei with the same grade in two ducts of different patients using 2-sided t-tests (P ≤ 0.05). Also, we compared image features for nuclei in patients with single grade to those with the same grade in patients with multiple grades using t-tests. Results Statistically significant differences were detected in nuclear features between ducts with the same nuclear grade, both in different ducts of the same patient, and between ducts in different patients with DCIS of more than one grade. Conclusion Nuclei in ducts visually described as having the same nuclear grade had significantly different subvisual digital image features. These subvisual differences may be considered additional manifestations of heterogeneity over and above differences that can be observed microscopically. This heterogeneity may explain the inconsistency of nuclear grading as a prognostic factor. PMID:20981137

  14. High-Performance Ducts in Hot-Dry Climates

    SciTech Connect

    Hoeschele, Marc; Chitwood, Rick; German, Alea; Weitzel, Elizabeth

    2015-07-30

    Duct thermal losses and air leakage have long been recognized as prime culprits in the degradation of heating, ventilating, and air-conditioning (HVAC) system efficiency. Both the U.S. Department of Energy’s Zero Energy Ready Home program and California’s proposed 2016 Title 24 Residential Energy Efficiency Standards require that ducts be installed within conditioned space or that other measures be taken to provide similar improvements in delivery effectiveness (DE). Pacific Gas & Electric Company commissioned a study to evaluate ducts in conditioned space and high-performance attics (HPAs) in support of the proposed codes and standards enhancements included in California’s 2016 Title 24 Residential Energy Efficiency Standards. The goal was to work with a select group of builders to design and install high-performance duct (HPD) systems, such as ducts in conditioned space (DCS), in one or more of their homes and to obtain test data to verify the improvement in DE compared to standard practice. Davis Energy Group (DEG) helped select the builders and led a team that provided information about HPD strategies to them. DEG also observed the construction process, completed testing, and collected cost data.

  15. [A case of lacrimal duct obstruction caused by capecitabine].

    PubMed

    Noguchi, Yusuke; Mitani, Takuya; Kawara, Hiroko; Tokuyama, Yoko; Tamura, Yoshiko; Uchiyama, Kiyoshi; Shimizu, Yoshihiro

    2015-01-01

    In recent years, the incidence of adverse ocular reactions, including corneal problems and lacrimal duct obstruction, due to antineoplastic agents such as S-1 has increased. Very few reports of adverse ocular reactions caused by capecitabine, a fluorinated pyrimidine antineoplastic agent like S-1, exist, and consequently, the mechanism underlying these reactions is not well understood. This report describes our recent experience with a case of lacrimal duct obstruction caused by capecitabine. The patient was a 71-year-old woman who was being administered trastuzumab plus capecitabine combination chemotherapy for breast cancer-related bone metastasis. She complained of epiphora 7 days after capecitabine was initiated. Thereafter, her capecitabine dose was reduced owing to exacerbation of hand-foot syndrome, but the epiphora persisted. Capecitabine was discontinued 287 days after initiation owing to exacerbation of the hand-foot syndrome. However, because the epiphora persisted, the patient visited the ophthalmology department. The ophthalmologist diagnosed the patient with binocular nasolacrimal duct obstruction and cataract, and prescribed a 0.3% gatifloxacin ophthalmic solution and 0.1% fluorometholone ophthalmic suspension. Thereafter, the epiphora reduced. When the patient returned to the ophthalmology department, symptom improvement was confirmed. In this case, lacrimal duct obstruction likely developed due to capecitabine. The symptoms were reversible with discontinuation of capecitabine and ophthalmic treatment. We believe that reporting this case could be valuable in discussing capecitabine-induced lacrimal duct obstruction. PMID:25596694

  16. Gastric metastasis from salivary duct carcinoma mimicking primary gastric cancer

    PubMed Central

    Yamashita, Kanefumi; Takeno, Shinsuke; Nimura, Satoshi; Sugiyama, Yoshikazu; Sueta, Takayuki; Maki, Kenji; Kayashima, Yoshiyuki; Shiwaku, Hironari; Kato, Daisuke; Hashimoto, Tatsuya; Sasaki, Takamitsu; Yamashita, Yuichi

    2016-01-01

    Introduction We present a very rare case of gastric metastasis mimicking primary gastric cancer in a patient who had undergone surgery for salivary duct carcinoma. Presentation of case A 67-year-old man had been diagnosed as having right parotid cancer and had undergone a right parotidectomy and lymph node dissection. The histological diagnosis was salivary duct carcinoma. One year after the surgery, a positron emission tomography–computed tomography scan using fluorodeoxyglucose (FDG) revealed an abnormal uptake of FDG in the left cervical, mediastinal, paraaortic, and cardiac lymph nodes; stomach; and pancreas. On gastroduodenoscopy, there was a huge, easily bleeding ulcer mimicking primary gastric cancer at the upper body of the stomach. Biopsy revealed poorly differentiated adenocarcinoma. Therefore, we were unable to differentiate between the primary gastric cancer and the metastatic tumor using gastroduodenoscopy and biopsy. Because of the uncontrollable bleeding from the gastric cancer, we performed an emergency palliative total gastrectomy. On histological examination, the gastric lesion was found to be metastatic carcinoma originating from the salivary duct carcinoma. Discussion In the presented case, we could not diagnose the gastric metastasis originating from the salivary duct carcinoma even by endoscopic biopsy. This is because the histological appearance of salivary duct carcinoma is similar to that of high-grade adenocarcinoma, thus, resembling primary gastric cancer. Conclusion When we perform endoscopic examination of patients with malignant neoplasias, a possibility of metastatic gastric cancer should be taken into consideration. PMID:27085106

  17. Comparison of evaporation duct and path loss models

    NASA Astrophysics Data System (ADS)

    Patterson, Wayne L.

    1985-09-01

    This paper will evaluate the current meteorological measurement techniques used to infer the evaporation-ducting process. Included within this study is a comparison of relative performance, sensitivities to meteorological inputs, and ease of computation for three standard evaporation duct models and two electromagnetic wave propagation models. The evaporation duct models performed reasonably and equally well when considering statistically averaged meteorological inputs, but all were extremely sensitive to point-observed meteorological input parameters. The measurement techniques employed by naval and transiting commercial vessels are not of sufficient quality to infer adequately the evaporation-ducting process. The theory behind calculation of path loss values based upon current evaporation duct inputs is statistically sound. For studies of propagation phenomena or development of electromagnetic systems, both of the compared models perform reasonably well and are accurate predictors. However, the use of either model for estimation of a single propagation range based upon a point meteorological observation is severely limited by the accuracy of the data.

  18. Ducts in the Attic? What Were They Thinking? Preprint

    SciTech Connect

    Roberts, D.; Winkler, J.

    2010-08-01

    As energy-efficiency efforts focus increasingly on existing homes, we scratch our heads about construction decisions made 30, 40, 50-years ago and ask: 'What were they thinking?' A logical follow-on question is: 'What will folks think in 2050 about the homes we're building today?' This question can lead to a lively discussion, but the current practice that we find most alarming is placing ducts in the attic. In this paper, we explore through literature and analysis the impact duct location has on cooling load, peak demand, and energy cost in hot climates. For a typical new home in these climates, we estimate that locating ducts in attics rather than inside conditioned space increases the cooling load 0.5 to 1 ton, increases cooling costs 15% and increases demand by 0.75 kW. The aggregate demand to service duct loss in homes built in Houston, Las Vegas, and Phoenix during the period 2000 through 2009 is estimated to be 700 MW. We present options for building homes with ducts in conditioned space and demonstrate that these options compare favorably with other common approaches to achieving electricity peak demand and consumption savings in homes.

  19. Management of excluded segmental bile duct leakage following liver resection

    PubMed Central

    Honoré, Charles; Vibert, Eric; Hoti, Emir; Azoulay, Daniel; Adam, René; Castaing, Denis

    2009-01-01

    Background: Postoperative bile leak secondary to a fistula is a known complication of hepatic surgery. Four different biliary fistula sub-types have been described: type A refers to minor leakage from the bile duct stump; type B to major leakage caused by insufficient closure of the bile duct stump; type C to major leakage caused by injury to the bile duct, and type D (the rarest) to the division and exclusion of a bile duct. This complication results from functional liver parenchyma in which bile drainage is excluded from the main duct. Methods: A retrospective review of the database for 163 patients diagnosed with post-hepatic surgery bile leak from April 1992 to June 2007 was performed. Results: Three patients were found to have type D biliary fistula, with durations of 3–21 months. The bile leak developed after a right hepatectomy in two patients and a right hepatectomy extending to segment IV in one patient. All three patients were rescheduled for surgical exploration, following failure of medical treatment. The procedure consisted of repeat resection of the independent liver parenchyma containing the fistula. One patient developed a postoperative leak from a hepaticojejunal anastomosis (treated conservatively) and the other two patients had an uneventful recovery. No recurrence of bile leak was encountered during their follow-up. Conclusions: Our experience indicates that conservative treatment is deceptive and not efficacious. For this condition, surgical intervention is the treatment of choice because it is very effective and is associated with a low morbidity. PMID:19718366

  20. The value of sonography in determining cystic duct patency.

    PubMed

    McGrath, F P; Gibney, R G; Burhenne, H J

    1992-07-01

    A prospective blinded comparison of ultrasonography (US) and oral cholecystography (OCG) was performed in 100 patients with symptomatic gall-stones to determine whether US would enable an accurate assessment of cystic duct patency to be made. Patency of the cystic duct was defined as gall-bladder opacification on OCG or a greater than 20% decrease in gall-bladder volume by US post-fatty meal. The ellipsoid method of volume measurement was used. Any patient who had a non-opacified gall-bladder on OCG but a greater than 20% volume decrease on US had cholescintigraphy performed (DISIDA). Oral cholecystography demonstrated cystic duct patency in 88 patients (88%), and fatty-meal gall-bladder US met the specified study criteria for patency in 86 patients (86%). False negative results were identified in four of the OCG and in six of the US examinations. The results of this study indicate that gall-bladder sonography with a post-fatty meal contraction of greater than 20% is a very accurate predictor of cystic duct patency. A contraction of less than 20%, however, cannot be considered a reliable predictor of cystic duct occlusion. PMID:1643780

  1. Measure Guideline: Optimizing the Configuration of Flexible Duct Junction Boxes

    SciTech Connect

    Beach, R.; Burdick, A.

    2014-03-01

    This measure guideline offers additional recommendations to heating, ventilation, and air conditioning (HVAC) system designers for optimizing flexible duct, constant-volume HVAC systems using junction boxes within Air Conditioning Contractors of America (ACCA) Manual D guidance (Rutkowski, H. Manual D -- Residential Duct Systems, 3rd edition, Version 1.00. Arlington, VA: Air Conditioning Contractors of America, 2009.). IBACOS used computational fluid dynamics software to explore and develop guidance to better control the airflow effects of factors that may impact pressure losses within junction boxes among various design configurations (Beach, R., Prahl, D., and Lange, R. CFD Analysis of Flexible Duct Junction Box Design. Golden, CO: National Renewable Energy Laboratory, submitted for publication 2013). These recommendations can help to ensure that a system aligns more closely with the design and the occupants' comfort expectations. Specifically, the recommendations described herein show how to configure a rectangular box with four outlets, a triangular box with three outlets, metal wyes with two outlets, and multiple configurations for more than four outlets. Designers of HVAC systems, contractors who are fabricating junction boxes on site, and anyone using the ACCA Manual D process for sizing duct runs will find this measure guideline invaluable for more accurately minimizing pressure losses when using junction boxes with flexible ducts.

  2. Evaluation of simplified evaporation duct refractivity models for inversion problems

    NASA Astrophysics Data System (ADS)

    Saeger, J. T.; Grimes, N. G.; Rickard, H. E.; Hackett, E. E.

    2015-10-01

    To assess a radar system's instantaneous performance on any given day, detailed knowledge of the meteorological conditions is required due to the dependency of atmospheric refractivity on thermodynamic properties such as temperature, water vapor, and pressure. Because of the significant challenges involved in obtaining these data, recent efforts have focused on development of methods to obtain the refractivity structure inversely using radar measurements and radar wave propagation models. Such inversion techniques generally use simplified refractivity models in order to reduce the parameter space of the solution. Here the accuracy of three simple refractivity models is examined for the case of an evaporation duct. The models utilize the basic log linear shape classically associated with evaporation ducts, but each model depends on various parameters that affect different aspects of the profile, such as its shape and duct height. The model parameters are optimized using radiosonde data, and their performance is compared to these atmospheric measurements. The optimized models and data are also used to predict propagation using a parabolic equation code with the refractivity prescribed by the models and measured data, and the resulting propagation patterns are compared. The results of this study suggest that the best log linear model formulation for an inversion problem would be a two-layer model that contains at least three parameters: duct height, duct curvature, and mixed layer slope. This functional form permits a reasonably accurate fit to atmospheric measurements as well as embodies key features of the profile required for correct propagation prediction with as few parameters as possible.

  3. [A case of primary neuroendocrine carcinoma of the bile duct].

    PubMed

    Hamanaka, Michiko; Nakahira, Shin; Takeda, Yutaka; Kawashima, Hiroshi; Mukai, Yosuke; Kanemura, Takeshi; Uchiyama, Chieko; Okishiro, Masatsugu; Takeno, Atsushi; Suzuki, Rei; Taniguchi, Hirokazu; Egawa, Chiyomi; Nakata, Ken; Miki, Hirofumi; Kato, Takeshi; Nagano, Teruaki; Nakatsuka, Shinichi; Tamura, Shigeyuki

    2012-11-01

    A 74-year-old man presented to a physician with a chief complaint of jaundice. He was diagnosed with bile duct carcinoma and admitted to our hospital. Laboratory data revealed abnormally elevated levels of total bilirubin, serum hepatic transaminase, and CA19-9. Endoscopic retrograde cholangiopancreatography revealed neoplastic stenosis from the hilus hepatis to the common bile duct. Abdominal computed tomography (CT) revealed an enhancing tumor in the hilus hepatis bile duct, and positron emission tomography-CT (PET-CT) revealed abnormal fluorodeoxyglucose accumulation in the tumor. Under a diagnosis of hilar cholangiocarcinoma, the patient underwent an extended right hepatectomy and left hepatico -jejunostomy. Immunohistochemically, the tumor cells were positive for neuroendocrine markers such as chromogranin A, synaptophysin, and CD56. The tumor was diagnosed as primary neuroendocrine carcinoma of the bile duct. The patient exhibited multiple liver metastasis 6 months after the operation. Transcatheter arterial chemoembolization (TACE) was performed for the liver metastasis. Although TACE exerted a cytoreductive effect temporarily, multiple liver abscesses developed. The patient died of liver failure 16 months after the operation. We report this rare case of primary neuroendocrine carcinoma of the bile duct. PMID:23267998

  4. Progenitor cell niches in the human pancreatic duct system and associated pancreatic duct glands: an anatomical and immunophenotyping study.

    PubMed

    Carpino, Guido; Renzi, Anastasia; Cardinale, Vincenzo; Franchitto, Antonio; Onori, Paolo; Overi, Diletta; Rossi, Massimo; Berloco, Pasquale Bartolomeo; Alvaro, Domenico; Reid, Lola M; Gaudio, Eugenio

    2016-03-01

    Pancreatic duct glands (PDGs) are tubule-alveolar glands associated with the pancreatic duct system and can be considered the anatomical counterpart of peribiliary glands (PBGs) found within the biliary tree. Recently, we demonstrated that endodermal precursor niches exist fetally and postnatally and are composed functionally of stem cells and progenitors within PBGs and of committed progenitors within PDGs. Here we have characterized more extensively the anatomy of human PDGs as novel niches containing cells with multiple phenotypes of committed progenitors. Human pancreata (n = 15) were obtained from cadaveric adult donors. Specimens were processed for histology, immunohistochemistry and immunofluorescence. PDGs were found in the walls of larger pancreatic ducts (diameters > 300 μm) and constituted nearly 4% of the duct wall area. All of the cells identified were negative for nuclear expression of Oct4, a pluripotency gene, and so are presumably committed progenitors and not stem cells. In the main pancreatic duct and in large interlobular ducts, Sox9(+) cells represented 5-30% of the cells within PDGs and were located primarily at the bottom of PDGs, whereas rare and scattered Sox9(+) cells were present within the surface epithelium. The expression of PCNA, a marker of cell proliferation, paralleled the distribution of Sox9 expression. Sox9(+) PDG cells proved to be Pdx1(+) /Ngn3(+/-) /Oct4A(-) . Nearly 10% of PDG cells were positive for insulin or glucagon. Intercalated ducts contained Sox9(+) /Pdx1(+) /Ngn3(+) cells, a phenotype that is presumptive of committed endocrine progenitors. Some intercalated ducts appeared in continuity with clusters of insulin-positive cells organized in small pancreatic islet-like structures. In summary, PDGs represent niches of a population of Sox9(+) cells exhibiting a pattern of phenotypic traits implicating a radial axis of maturation from the bottoms of the PDGs to the surface of pancreatic ducts. Our results complete the

  5. Mode Propagation in Nonuniform Circular Ducts with Potential Flow

    NASA Technical Reports Server (NTRS)

    Cho, Y. C.; Ingard, K. U.

    1982-01-01

    A previously reported closed form solution is expanded to determine effects of isentropic mean flow on mode propagation in a slowly converging-diverging duct, a circular cosh duct. On the assumption of uniform steady fluid density, the mean flow increases the power transmission coefficient. The increase is directly related to the increase of the cutoff ratio at the duct throat. With the negligible transverse gradients of the steady fluid variables, the conversion from one mode to another is negligible, and the power transmission coefficient remains unchanged with the mean flow direction reversed. With a proper choice of frequency parameter, many different modes can be made subject to a single value of the power transmission loss. A systematic method to include the effects of the gradients of the steady fluid variables is also described.

  6. Congenital absence of the gallbladder and the cystic duct.

    PubMed

    Bekele, Zenebe

    2002-04-01

    A 47 years old female with congenital absence of the gallbladder and the cystic duct was presented. The diagnosis was confirmed by exploratory laparatomy, common duct tube cholangiography, and ultrasonography. Most of the operated cases of congenital absence of the gallbladder are symptomatic, and they get relief after common duct exploration. Although the biliary tree is normal on inspection at exploration, it is believed that the symptomatology may have root in congenital abnormality of function. Treatment of the agenesis of the gallbladder as described in earlier days has been discussed. In the present situation, specially in a country like Ethiopia where long time care of internal drains is a worrisome problem, and a major point for concern, the author believes choledocho-enteric anastomosis to be a good solution. PMID:12240579

  7. Externalized decondensed neutrophil chromatin occludes pancreatic ducts and drives pancreatitis.

    PubMed

    Leppkes, Moritz; Maueröder, Christian; Hirth, Sebastian; Nowecki, Stefanie; Günther, Claudia; Billmeier, Ulrike; Paulus, Susanne; Biermann, Mona; Munoz, Luis E; Hoffmann, Markus; Wildner, Dane; Croxford, Andrew L; Waisman, Ari; Mowen, Kerri; Jenne, Dieter E; Krenn, Veit; Mayerle, Julia; Lerch, Markus M; Schett, Georg; Wirtz, Stefan; Neurath, Markus F; Herrmann, Martin; Becker, Christoph

    2016-01-01

    Ductal occlusion has been postulated to precipitate focal pancreatic inflammation, while the nature of the primary occluding agents has remained elusive. Neutrophils make use of histone citrullination by peptidyl arginine deiminase-4 (PADI4) in contact to particulate agents to extrude decondensed chromatin as neutrophil extracellular traps (NETs). In high cellular density, NETs form macroscopically visible aggregates. Here we show that such aggregates form inside pancreatic ducts in humans and mice occluding pancreatic ducts and thereby driving pancreatic inflammation. Experimental models indicate that PADI4 is critical for intraductal aggregate formation and that PADI4-deficiency abrogates disease progression. Mechanistically, we identify the pancreatic juice as a strong instigator of neutrophil chromatin extrusion. Characteristic single components of pancreatic juice, such as bicarbonate ions and calcium carbonate crystals, induce aggregated NET formation. Ductal occlusion by aggregated NETs emerges as a pathomechanism with relevance in a plethora of inflammatory conditions involving secretory ducts. PMID:26964500

  8. Endoscopic management of difficult common bile duct stones

    PubMed Central

    Trikudanathan, Guru; Navaneethan, Udayakumar; Parsi, Mansour A

    2013-01-01

    Endoscopy is widely accepted as the first treatment option in the management of bile duct stones. In this review we focus on the alternative endoscopic modalities for the management of difficult common bile duct stones. Most biliary stones can be removed with an extraction balloon, extraction basket or mechanical lithotripsy after endoscopic sphincterotomy. Endoscopic papillary balloon dilation with or without endoscopic sphincterotomy or mechanical lithotripsy has been shown to be effective for management of difficult to remove bile duct stones in selected patients. Ductal clearance can be safely achieved with peroral cholangioscopy guided laser or electrohydraulic lithotripsy in most cases where other endoscopic treatment modalities have failed. Biliary stenting may be an alternative treatment option for frail and elderly patients or those with serious co morbidities. PMID:23345939

  9. Probing of congenital nasolacrimal duct obstruction with dacryoendoscope

    PubMed Central

    Kato, Kumiko; Matsunaga, Koichi; Takashima, Yuko; Kondo, Mineo

    2014-01-01

    Background A congenital nasolacrimal duct obstruction (CNLDO) is a relatively common disease in infants. We evaluated the results of probing three patients with CNLDO, under direct view, with a dacryoendoscope. Methods Three cases of CNLDO were examined and treated by probing with a dacryoendoscope, under intravenous anesthesia. The diameter of the dacryoendoscope probe was 0.7 mm, and we were able to observe the inner walls of the lacrimal duct and able to guide the probe through the duct. Results In all cases, the site of obstruction was detected, and the probe was used to remove the obstruction. At 2 weeks after the removal of the obstruction, there was no epiphora or mucopurulent discharge in any of the cases. No complications were detected intra- and postoperatively. Conclusion Although only three cases were studied, we believe that probing with a dacryoendoscope is a safe and effective method of treating a CNLDO. More cases need to be studied. PMID:24876765

  10. Externalized decondensed neutrophil chromatin occludes pancreatic ducts and drives pancreatitis

    PubMed Central

    Leppkes, Moritz; Maueröder, Christian; Hirth, Sebastian; Nowecki, Stefanie; Günther, Claudia; Billmeier, Ulrike; Paulus, Susanne; Biermann, Mona; Munoz, Luis E.; Hoffmann, Markus; Wildner, Dane; Croxford, Andrew L.; Waisman, Ari; Mowen, Kerri; Jenne, Dieter E.; Krenn, Veit; Mayerle, Julia; Lerch, Markus M.; Schett, Georg; Wirtz, Stefan; Neurath, Markus F.; Herrmann, Martin; Becker, Christoph

    2016-01-01

    Ductal occlusion has been postulated to precipitate focal pancreatic inflammation, while the nature of the primary occluding agents has remained elusive. Neutrophils make use of histone citrullination by peptidyl arginine deiminase-4 (PADI4) in contact to particulate agents to extrude decondensed chromatin as neutrophil extracellular traps (NETs). In high cellular density, NETs form macroscopically visible aggregates. Here we show that such aggregates form inside pancreatic ducts in humans and mice occluding pancreatic ducts and thereby driving pancreatic inflammation. Experimental models indicate that PADI4 is critical for intraductal aggregate formation and that PADI4-deficiency abrogates disease progression. Mechanistically, we identify the pancreatic juice as a strong instigator of neutrophil chromatin extrusion. Characteristic single components of pancreatic juice, such as bicarbonate ions and calcium carbonate crystals, induce aggregated NET formation. Ductal occlusion by aggregated NETs emerges as a pathomechanism with relevance in a plethora of inflammatory conditions involving secretory ducts. PMID:26964500

  11. Thyroglossal duct cyst accompanied by laryngomalacia and pulmonary sequestration.

    PubMed

    Yagasaki, Hideaki; Makino, Koichi; Goto, Yusuke; Suzuki, Takeyuki; Oyachi, Noboru; Obana, Kazuko; Ko, Junichi; Komai, Takayuki

    2014-06-01

    A 2-month-old full-term female infant developed nasal stridor, which progressed to respiratory distress and poor sucking ability. Direct pharyngoscopy showed laryngomalacia and a midline cystic mass in the lingual region. The mass pressed on the epiglottis, causing dyspnea. Computed tomography incidentally revealed extralobar pulmonary sequestration. Direct deroofing of the lingual cyst and plication of the epiglottis were performed at 3 months of age, and the patient recovered from the respiratory distress. Histopathology of the cystic mass showed a thyroglossal duct cyst. Thoracoscopic resection of the pulmonary sequestration was then done at 17 months of age. Thyroglossal duct cysts in the lingual region may cause destabilization of the epiglottis and laryngomalacia, resulting in acquired respiratory obstruction. The combination of thyroglossal duct cyst, laryngomalacia, and pulmonary sequestration is rare; therefore, reports must be accumulated in order to explore the embryological origins of such cases. PMID:24894942

  12. Study of Relationship Between the Blood Supply of the Extrahepatic Bile Duct and Duct Supply Branches from Gastroduodenal Artery on Imaging and Anatomy

    PubMed Central

    Dai, Jie; Wu, Xiao-Feng; Yang, Chun; Li, Hong-Jun; Chen, Ya-Liang; Liu, Guo-Zhen; Song, Yi-Zhi; Wu, Huan-Huan; Ding, Jin-Li; Li, Ning

    2015-01-01

    Background: Liver transplantation has become the treatment of choice for patients with end-stage acute or chronic hepatic disease. Bile duct complications are common events after liver transplantation. The aim of this study was to evaluate the blood supply of the human bile duct and identify the underlying mechanisms of bile duct complications after liver transplantation. Methods: The duct supply branches from gastroduodenal artery and blood supply of extrahepatic bile duct system were re-evaluated through selective hepatic angiography from 600 patients. In addition, 33 cadavers were injected with latex casting material into the common hepatic artery, then the extrahepatic bile duct and the branches from the common hepatic artery were carefully dissected to visualize the gastroduodenal artery and its branching to the extrahepatic bile duct. Results: The bile duct artery arose from the branch of the gastroduodenal artery in 8.1% (49/600). Of these 49 individuals, the bile duct artery was supplied by the gastroduodenal artery (61.22%, 30/49), the proper hepatic artery (14.29%, 7/49), or both the gastroduodenal artery and the proper hepatic artery (24.49%, 12/49). In our study of 33 cadavers, the percentage that the bile duct artery arose from the gastroduodenal artery was 27.27%. The blood supply to the bile extrahepatic bile ducts was divided into different segments and formed longitudinal and arterial network anastomosed on the walls of the duct. Conclusions: There is a close relationship between the duct supply branches from gastroduodenal artery and the blood supplying patterns of the extrahepatic bile duct system. In liver transplant surgery, the initial part of the gastroduodenal artery is preferred to be preserved in the donor liver. It is of great significance to improve the success rate of operation and reduce complications. PMID:25635427

  13. CASE STUDY OF DUCT RETROFIT OF A 1985 HOME AND GUIDELINES FOR ATTIC AND CRAWL SPACE DUCT SEALING

    SciTech Connect

    Boudreaux, Philip R; Christian, Jeffrey E; Jackson, Roderick K

    2012-01-01

    The U.S. Department of Energy (DOE) is fully committed to research for developing the information and capabilities necessary to provide cost-effective residential retrofits yielding 50% energy savings within the next several years. Heating, ventilation, and air conditioning (HVAC) is the biggest energy end use in the residential sector, and a significant amount of energy can be wasted through leaky ductwork in unconditioned spaces such as attics and crawl spaces. A detailed duct sealing case study is presented for one house along with nine brief descriptions of other duct retrofits completed in the mixed-humid climate. Costs and estimated energy savings are reported for most of the ten houses. Costs for the retrofits ranged from $0.92/ft2 to $1.80/ft2 of living space and estimated yearly energy cost savings due to the duct retrofits range from 1.8% to 18.5%. Lessons learned and duct sealing guidelines based on these ten houses, as well as close work with the HVAC industry in the mixed-humid climate of East Tennessee, northern Georgia, and south-central Kentucky are presented. It is hoped that the lessons learned and guidelines will influence local HVAC contractors, energy auditors, and homeowners when diagnosing or repairing HVAC duct leakage and will be useful for steering DOE s future research in this area.

  14. Moulded calculus of common bile duct mimicking a stenosis

    PubMed Central

    Brocki, Marian; Śmigielski, Jacek

    2014-01-01

    Bile duct stenosis, in most cases, appears to be the consequence of pancreatic head, ampulla of Vater and bile duct tumours, cholangitis sclerosans, as well as iatrogenic damages, which may all be diagnosed during endoscopic retrograde cholangiopancreatography (ERCP). In very rare cases the restriction may result from an atypically shaped wedged stone. This situation creates many diagnostic problems, which in the majority of cases can be solved using imaging studies. However, in some patients even a significant extension of diagnostic procedures may not lead to a correct diagnosis. We present a diagnostically difficult case of a deposit imitating restriction. We present a 70-year-old woman with common bile duct restriction undiagnosed despite several ultrasound examinations (USG), computed tomography (CT), double magnetic resonance cholangiopancreatography (MRCP) and endoscopic retrograde cholangiopancreatography (ERCP). Only after the third ERCP examination a fragmented, by formerly introduced prosthesis, deposit, imitating narrowing, was revealed. Identification of bile duct deposits depends on their composition, localisation and the imaging techniques used. Pigment calculi with atypical shape, bile density, air density or surrounding tissue density are very difficult to diagnose. Thus, the sensitivity of common bile duct stone detection in USG, CT, MRCP and endoscopic ultrasound (EUS) is 5–88%; 6–88%; 73–97%; and 84–98%, respectively. Moreover, ERCP may not diagnose the character of the restriction even in 5.2% up to 30% of the patients. Consequently, assessment of diagnosis in a number of patients is difficult. A deposit imitating common bile duct (CBD) restriction is a rare, difficult to diagnose phenomenon, which should be taken into account during differential diagnosis of CBD restrictions. PMID:25061493

  15. Sound transmission in ducts containing nearly choked flows

    NASA Technical Reports Server (NTRS)

    Callegari, A. J.; Myers, M. K.

    1979-01-01

    The nonlinear theory previously developed by the authors (1977, 1978) is used to obtain numerical results for sound transmission through a nearly choked throat in a variable-area duct. Parametric studies are performed for different source locations, strengths and frequencies. It is shown that the nonlinear interactions in the throat region generate superharmonics of the fundamental (source) frequency throughout the duct. The amplitudes of these superharmonics increase as the source parameters (frequency and strength) are increased toward values leading to acoustic shocks. For a downstream source, superharmonics carry about 20% of the total acoustic power as shocking conditions are approached. For the source strength levels and frequencies considered, streaming effects are negligible.

  16. Sound propagation through a variable area duct - Experiment and theory

    NASA Technical Reports Server (NTRS)

    Silcox, R. J.; Lester, H. C.

    1981-01-01

    A comparison of experiment and theory has been made for the propagation of sound through a variable area axisymmetric duct with zero mean flow. Measurement of the acoustic pressure field on both sides of the constricted test section was resolved on a modal basis for various spinning mode sources. Transmitted and reflected modal amplitudes and phase angles were compared with finite element computations. Good agreement between experiment and computation was obtained over a wide range of frequencies and modal transmission variations. The study suggests that modal transmission through a variable area duct is governed by the throat modal cut-off ratio.

  17. Periductal mastitis and mammary duct ectasia in a male.

    PubMed Central

    Ashworth, M. T.; Corcoran, G. D.; Haqqani, M. T.

    1985-01-01

    A case of periductal mastitis and mammary duct ectasia is presented in a 50 year old male, with presenting symptoms similar to those of females, namely subareolar breast lump and mastalgia. As far as can be ascertained only 4 cases of mammary duct ectasia and periductal mastitis in males have been reported previously. Since this entity is not well known in males it is possible that it may be underdiagnosed or misdiagnosed clinically and histologically. Images Figure 1 Figure 2 Figure 3 PMID:4040633

  18. Turbulent jet flow in a duct with a circulation zone

    NASA Astrophysics Data System (ADS)

    Glebov, G. A.; Petrov, V. N.

    An approximation method is proposed for calculating flows resulting from the interaction between a turbulent jet and a slipstream inside a duct, including the case where a back stream is formed near the wall. In accordance with the approach proposed here, the velocity profile in the mixing region is determined using the well known method of the polynomial approximation of the Reynolds shear stress profile in the duct cross-sections. The flow parameters are then determined using integral equations of flow rate and momentum. The results obtained using the approximation method are found to be in good agreement with experiment data.

  19. Whistler propagation in ionospheric density ducts: Simulations and DEMETER observations

    NASA Astrophysics Data System (ADS)

    Woodroffe, J. R.; Streltsov, A. V.; Vartanyan, A.; Milikh, G. M.

    2013-11-01

    On 16 October 2009, the Detection of Electromagnetic Emissions Transmitted from Earthquake Regions (DEMETER) satellite observed VLF whistler wave activity coincident with an ionospheric heating experiment conducted at HAARP. At the same time, density measurements by DEMETER indicate the presence of multiple field-aligned enhancements. Using an electron MHD model, we show that the distribution of VLF power observed by DEMETER is consistent with the propagation of whistlers from the heating region inside the observed density enhancements. We also discuss other interesting features of this event, including coupling of the lower hybrid and whistler modes, whistler trapping in artificial density ducts, and the interference of whistlers waves from two adjacent ducts.

  20. Prediction of the acoustic impedance of duct liners

    NASA Technical Reports Server (NTRS)

    Zorumski, W. E.; Tester, B. J.

    1976-01-01

    Recent research which contributes to the prediction of the acoustic impedance of duct liners is reviewed. This review includes the linear and nonlinear properties of sheet and bulk type materials and methods for the measurement of these properties. It also includes the effect of grazing flow on the acoustic properties of materials. Methods for predicting the properties of single or multilayered, point reacting or extended reaction, and flat or curved liners are discussed. Based on this review, methods for predicting the properties of the duct liners which are typically used in aircraft engines are recommended. Some areas of needed research are discussed briefly.

  1. Bundle duct interaction studies for fuel assemblies. [LMFBR

    SciTech Connect

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

    1981-06-01

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

  2. Fundamental investigation of duct/ESP phenomena. Final report

    SciTech Connect

    Brown, C.A.; Durham, M.D.; Sowa, W.A.; Himes, R.M.; Mahaffey, W.A.

    1991-10-21

    Radian Corporation was contracted to investigate duct injection and ESP phenomena in a 1.7 MW pilot plant constructed for this test program. This study was an attempt to resolve problems found in previous studies and answer remaining questions for the technology using an approach which concentrates on the fundamental mechanisms of the process. The goal of the study was to obtain a better understanding of the basic physical and chemical phenomena that control: (1) the desulfurization of flue gas by calcium-based reagent, and (2) the coupling of an existing ESP particulate collection device to the duct injection process. Process economics are being studied by others. (VC)

  3. Effects of mean flow on duct mode optimum suppression rates

    NASA Technical Reports Server (NTRS)

    Kraft, R. E.; Wells, W. R.

    1976-01-01

    The nature of the solution to the convected acoustic wave equation and associated boundary conditions for rectangular ducts containing uniform mean flow is examined in terms of the complex mapping between the wall admittance and characteristic mode eigenvalues. It is shown that the Cremer optimum suppression criteria must be modified to account for the effects of flow below certain critical values of the nondimensional frequency parameter of duct height divided by sound wavelength. The implications of these results on the design of low frequency suppressors are considered.

  4. Giant submandibular gland duct sialolith mimicking an impacted canine tooth

    PubMed Central

    Bhullar, Ramandeep Singh; Dhawan, Amit; Bhullar, Kanwalpreet; Malhotra, Sonia

    2015-01-01

    Sialolithiasis is the most common disease affecting the salivary glands and accounts for 80% of salivary gland disorders. Chronic sialolithiasis promotes stone formation. Size of the salivary stones may range from 0.1 mm to 30 mm or be even bigger. Those salivary stones, the size of which exceeds 15 mm in any one dimension or 1 g in weight are classified as giant sialoliths. Giant sialoliths of the submandibular gland duct are rarely reported. Here, we report a case of a giant sialolith of the submandibular gland duct mimicking an impacted mandibular canine tooth on routine radiographic examination and its surgical management through an intraoral approach. PMID:26668461

  5. Case report of giant sialolith (megalith) of the Wharton's duct.

    PubMed

    Omezli, M M; Ayranci, F; Sadik, E; Polat, M E

    2016-01-01

    Sialolithiasis is the most common disease of salivary glands. Its estimated frequency is 1.2% in the adult population. Sialoliths most commonly occur in the submandibular glands. The sublingual gland and minor salivary glands are rarely affected. The sialolith usually measures from 1 to <10 mm. Giant sialoliths are classified as those exceeding 15 mm in any one dimension. In literature, large sialoliths or megalith (> mm) of Wharton's duct have rarely been reported. This case report describes a patient presenting with an unusually large sialolith (megalith) of Wharton's duct, which was 37 mm ×16 mm in the size, the subsequent patient management, the etiology, diagnosis, and its treatment. PMID:27022811

  6. Giant submandibular gland duct sialolith mimicking an impacted canine tooth.

    PubMed

    Bhullar, Ramandeep Singh; Dhawan, Amit; Bhullar, Kanwalpreet; Malhotra, Sonia

    2015-01-01

    Sialolithiasis is the most common disease affecting the salivary glands and accounts for 80% of salivary gland disorders. Chronic sialolithiasis promotes stone formation. Size of the salivary stones may range from 0.1 mm to 30 mm or be even bigger. Those salivary stones, the size of which exceeds 15 mm in any one dimension or 1 g in weight are classified as giant sialoliths. Giant sialoliths of the submandibular gland duct are rarely reported. Here, we report a case of a giant sialolith of the submandibular gland duct mimicking an impacted mandibular canine tooth on routine radiographic examination and its surgical management through an intraoral approach. PMID:26668461

  7. Salivary duct carcinoma of the parotid gland: A case report and review of the literature

    PubMed Central

    XIE, SHULE; YANG, HONGYU; BREDELL, MARIUS; SHEN, SHIYUE; YANG, HUIJUN; JIN, LONG; ZHANG, SHANSHAN

    2015-01-01

    Salivary duct carcinoma (SDC) is a rare and aggressive parotid malignancy that most commonly affects males in the fifth and sixth decades of life. Histopathology specimens obtained from SDC patients demonstrate a resemblance to ductal carcinoma of the breast. Therefore, to distinguish SDC from breast ductal carcinoma, several immunohistochemical markers exist that may enable surgeons to make an accurate diagnosis. In this study, the case of a 54-year-old male with salivary duct carcinoma of the right parotid gland is presented. The results of the present case study revealed that the SDC sample was positive for the expression of human epidermal growth factor 2 (Her-2), cytokeratin (CK) 8/CK 18, p63, high molecular weight CK and calponin, and negative for expression of the estrogen receptor and progesterone receptor. Based on the result, an ipsilateral selective neck dissection followed by adjuvant post-operative radiation therapy was suitable at the primary treatment stage. At one year of follow-up, the patient was alive and free of recurrence. In advanced cases of SDC, treatment with anti-HER-2 monoclonal antibodies, such as trastuzumab, is recommended. PMID:25435994

  8. Remote sensing of the evaporation duct using an X-band radar

    NASA Astrophysics Data System (ADS)

    Anderson, Kenneth D.

    1992-02-01

    Results from a unique analytical and measurement effort to assess low-altitude short-range radar detection capabilities in an evaporation ducting environment are presented. Although the measurement effort is ongoing, current results for unstable conditions validate propagation model predictions of reduced radar detection ranges within the radio horizon. In addition, discrepancies between measured and predicted radar data demand a close examination of both meteorological data and surface layer theory. At ranges near and beyond the horizon, radar detection capabilities crucially depend both on the surface layer refractivity profile and on the refractivity profile determined from upper-air observation. An empirical model to merge the surface layer with the mixed layer is discussed. Other discrepancies, which are thought to be caused either by inadequate surface layer modeling or by inadequate surface layer meteorological measurements, suggest the need for an improved surface layer model. Remote sensing of the evaporation duct by radar measurements is not a viable tactical tool. However, the combination of direct surface and upper-air meteorological measurements with remotely sensed radar measurements and with advanced numerical modeling capabilities does provide valuable insight for a better understanding of the atmospheric surface layer and its effects on low-altitude short-range radar detection.

  9. Building America Top Innovations 2013 Profile – Buried and Encapsulated Ducts

    SciTech Connect

    none,

    2013-09-01

    In this innovation profile, CARB research shows HVAC ducts that are encapsulated in closed-cell spray foam and buried in blown insulation in a vented attic meet the code requirements for ducts in conditioned space.

  10. Investigation of the tone-burst tube for duct lining attenuation measurement

    NASA Technical Reports Server (NTRS)

    Soffel, A. R.; Morrow, P. F.

    1972-01-01

    The tone burst technique makes practical the laboratory evaluation of potential inlet and discharge duct treatments. Tone burst apparatus requires only simple machined parts and standard components. Small, simply made, lining samples are quickly and easily installed in the system. Two small electromagnetric loudspeaker drivers produce peak sound pressure level of over 166 db in the 3-square-inch sample duct. Air pump available in most laboratories can produce air flows of over plus and minus Mach 0.3 in the sample duct. The technique uses short shaped pulses of sound propagated down a progressive wave tube containing the sample duct. The peak pressure level output of the treated duct is compared with the peak pressure level output of a substituted reference duct. The difference between the levels is the attenuation or insertion loss of the treated duct. Evaluations of resonant absorber linings by the tone burst technique check attenuation values predicted by empirical formulas based on full scale ducts.

  11. Building America Top Innovations 2012: Integration of HVAC System Design with Simplified Duct Distribution

    SciTech Connect

    none,

    2013-01-01

    This Building America Top Innovations profile describes work by Building America research teams who field tested simplified duct designs in hundreds of homes, confirming the performance of short compact duct runs, with supply registers near interior walls.

  12. ASSESSMENT OF FUNGAL (PENICILLIUM CHRYSOGENUM) GROWTH ON THREE HVAC DUCT MATERIALS

    EPA Science Inventory

    The article discusses laboratory experiments to evaluate the susceptibility of three ventilation duct materials (fibrous glass ductboard, galvanized steel, and insulated flexible duct) to fungal (P. chrysogenum) growth. [NOTE: Many building investigators have documented fungal bi...

  13. Effect of flow on the acoustic resonances of an open-ended duct

    NASA Technical Reports Server (NTRS)

    Ingard, U.; Singhal, V. K.

    1975-01-01

    The effect of flow on the acoustic resonances of an open-ended, hard-walled duct is analyzed. The flow produces acoustic losses both in the interior of the duct and at the ends. Unless the duct is very long, typically 100 times the diameter, the losses at the ends dominate. At flow Mach numbers in excess of 0.4 the losses are so large that axial duct resonances are almost completely suppressed. The plane-wave Green's function for the duct with flow is expressed in terms of the (experimentally determined) pressure reflection coefficients at the ends of the duct, and the flow dependence of the complex eigenfrequencies of the duct is obtained. Some observations concerning the noise produced by the flow in the duct are also reported.

  14. Minimum airflow reset of single-duct VAV terminal boxes

    NASA Astrophysics Data System (ADS)

    Cho, Young-Hum

    Single duct Variable Air Volume (VAV) systems are currently the most widely used type of HVAC system in the United States. When installing such a system, it is critical to determine the minimum airflow set point of the terminal box, as an optimally selected set point will improve the level of thermal comfort and indoor air quality (IAQ) while at the same time lower overall energy costs. In principle, this minimum rate should be calculated according to the minimum ventilation requirement based on ASHRAE standard 62.1 and maximum heating load of the zone. Several factors must be carefully considered when calculating this minimum rate. Terminal boxes with conventional control sequences may result in occupant discomfort and energy waste. If the minimum rate of airflow is set too high, the AHUs will consume excess fan power, and the terminal boxes may cause significant simultaneous room heating and cooling. At the same time, a rate that is too low will result in poor air circulation and indoor air quality in the air-conditioned space. Currently, many scholars are investigating how to change the algorithm of the advanced VAV terminal box controller without retrofitting. Some of these controllers have been found to effectively improve thermal comfort, indoor air quality, and energy efficiency. However, minimum airflow set points have not yet been identified, nor has controller performance been verified in confirmed studies. In this study, control algorithms were developed that automatically identify and reset terminal box minimum airflow set points, thereby improving indoor air quality and thermal comfort levels, and reducing the overall rate of energy consumption. A theoretical analysis of the optimal minimum airflow and discharge air temperature was performed to identify the potential energy benefits of resetting the terminal box minimum airflow set points. Applicable control algorithms for calculating the ideal values for the minimum airflow reset were developed and

  15. Measure Guideline: Summary of Interior Ducts in New Construction, Including an Efficient, Affordable Method to Install Fur-Down Interior Ducts

    SciTech Connect

    Beal, D.; McIlvaine , J.; Fonorow, K.; Martin, E.

    2011-11-01

    This document illustrates guidelines for the efficient installation of interior duct systems in new housing, including the fur-up chase method, the fur-down chase method, and interior ducts positioned in sealed attics or sealed crawl spaces. This document illustrates guidelines for the efficient installation of interior duct systems in new housing. Interior ducts result from bringing the duct work inside a home's thermal and air barrier. Architects, designers, builders, and new home buyers should thoroughly investigate any opportunity for energy savings that is as easy to implement during construction, such as the opportunity to construct interior duct work. In addition to enhanced energy efficiency, interior ductwork results in other important advantages, such as improved indoor air quality, increased system durability and increased homeowner comfort. While the advantages of well-designed and constructed interior duct systems are recognized, the implementation of this approach has not gained a significant market acceptance. This guideline describes a variety of methods to create interior ducts including the fur-up chase method, the fur-down chase method, and interior ducts positioned in sealed attics or sealed crawl spaces. As communication of the intent of an interior duct system, and collaboration on its construction are paramount to success, this guideline details the critical design, planning, construction, inspection, and verification steps that must be taken. Involved in this process are individuals from the design team; sales/marketing team; and mechanical, insulation, plumbing, electrical, framing, drywall and solar contractors.

  16. Conceptual design study of advanced acoustic-composite nacelles

    NASA Technical Reports Server (NTRS)

    Nordstrom, K. E.; Marsh, A. H.; Sargisson, D. F.

    1975-01-01

    Conceptual studies were conducted to assess the impact of incorporating advanced technologies in the nacelles of a current wide-bodied transport and an advanced technology transport. The improvement possible in the areas of fuel consumption, flyover noise levels, airplane weight, manufacturing costs, and airplane operating cost were evaluated for short and long-duct nacelles. Use of composite structures for acoustic duct linings in the fan inlet and exhaust ducts was considered as well as for other nacelle components. For the wide-bodied transport, the use of a long-duct nacelle with an internal mixer nozzle in the primary exhaust showed significant improvement in installed specific fuel consumption and airplane direct operating costs compared to the current short-duct nacelle. The long-duct mixed-flow nacelle is expected to achieve significant reductions in jet noise during takeoff and in turbo-machinery noise during landing approach. Recommendations were made of the technology development needed to achieve the potential fuel conservation and noise reduction benefits.

  17. On the propagation of long waves in acoustically treated, curved ducts

    NASA Technical Reports Server (NTRS)

    Rostafinski, W.

    1981-01-01

    A two dimensional study is presented on the behavior of long waves in lined, curved ducts. The analysis includes a comparison between the propagation in curved and straight lined ducts. A parametric study was conducted over a range of wall admittance and duct wall separation. The complex eigenvalues of the characteristic equation, which in the case of a curved duct are also the angular wavenumbers, were obtained by successive approximations.

  18. Wharton's Duct Sialolith of Unusual Size: A Case Report with a Review of the Literature

    PubMed Central

    Mathew Cherian, Nithin; Vichattu, Sankar Vinod; Thomas, Ninan; Varghese, Aabu

    2014-01-01

    There is an increased incidence of submandibular gland duct developing sialoliths. Among them the sialoliths attaining a size of more than 1.5 cms are rare. Here we present a case with an abnormally sized sialolith in Wharton's duct and a review of the literature about the abnormally sized sialoliths and various anatomical and physiological considerations of the duct which contribute to the higher incidence of sialolith in the duct. PMID:25405038

  19. Resolution of Congenital Nasolacrimal Duct Obstruction with Nonsurgical Management

    PubMed Central

    2012-01-01

    Objective To determine how often nasolacrimal duct obstruction (NLDO) resolves with 6 months of nonsurgical management in infants aged 6 to <10 months old. Methods As part of a randomized trial evaluating the cost effectiveness of immediate office probing versus observation with deferred probing for unresolved cases, 107 infants aged 6 to <10 months old who had NLDO and no history of prior nasolacrimal duct surgery were prescribed 6 months of nasolacrimal duct massage and topical antibiotics as needed. Resolution of the nasolacrimal duct obstruction was assessed 6 months after study entry and was defined as the absence of all clinical signs of NLDO (epiphora, increased tear lake, or mucous discharge) and not having undergone NLDO surgery. Exploratory analyses assessed whether baseline characteristics including age, gender, laterality, and prior treatment were associated with the probability of NLDO resolving without surgery. Results At the 6-month examination, which was completed for 117 of the 133 eyes (88%), the NLDO had resolved without surgery in 77 eyes (66%, 95% CI = 56% to 74%). None of the baseline characteristics we evaluated were found to be associated with resolution. Discussion In infants 6 to < 10 months of age, more than half of eyes with NLDO resolve within 6 months with nonsurgical management. Knowledge of the rate of NLDO resolution in infancy without surgery will help clinicians and parents effectively discuss treatment options. PMID:22801833

  20. 63. Historic detail drawing of inlet duct cone on exhaust ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    63. Historic detail drawing of inlet duct cone on exhaust scrubber at building 202, June 18, 1955. NASA GRC drawing no. CD-101266. (On file at NASA Glenn Research Center). - Rocket Engine Testing Facility, GRC Building No. 202, NASA Glenn Research Center, Cleveland, Cuyahoga County, OH

  1. Experimental study on the particles deposition in the sampling duct

    SciTech Connect

    Vendel, J.; Charuau, J.

    1995-02-01

    A high standard of protection against the harmful effects of radioactive aerosol dissemination requires a measurement, as representative as possible, of their concentration. This measurement depends on the techniques used for aerosol sampling and transfer to the detector, as well as on the location of the latter with respect to the potential sources. The aeraulic design of the apparatus is also an important factor. Once collected the aerosol particles often have to travel through a variably shaped duct to the measurement apparatus. This transport is responsible for losses due to the particles deposition on the walls, leading to a distortion on the concentration measurements and a change in the particle size distribution. To estimate and minimize measurement errors it is important to determine the optimal transport conditions when designing a duct; its diameter and material, the radius of curvature of the bends and the flow conditions must be defined in particular. This paper presents an experimental study in order to determine, for each deposition mechanism, the retained fraction, or the deposition velocity for different flow regimes. This study has pointed out that it exists a favourable flow regime for the particle transport through the sampling ducts (2 500 < Re < 5 000). It has been established, for any particle diameters, equations to predict the aerosol penetration in smooth-walled cylindrical metal ducts.

  2. The Detection of Radiated Modes from Ducted Fan Engines

    NASA Technical Reports Server (NTRS)

    Farassat, F.; Nark, Douglas M.; Thomas, Russell H.

    2001-01-01

    The bypass duct of an aircraft engine is a low-pass filter allowing some spinning modes to radiate outside the duct. The knowledge of the radiated modes can help in noise reduction, as well as the diagnosis of noise generation mechanisms inside the duct. We propose a nonintrusive technique using a circular microphone array outside the engine measuring the complex noise spectrum on an arc of a circle. The array is placed at various axial distances from the inlet or the exhaust of the engine. Using a model of noise radiation from the duct, an overdetermined system of linear equations is constructed for the complex amplitudes of the radial modes for a fixed circumferential mode. This system of linear equations is generally singular, indicating that the problem is illposed. Tikhonov regularization is employed to solve this system of equations for the unknown amplitudes of the radiated modes. An application of our mode detection technique using measured acoustic data from a circular microphone array is presented. We show that this technique can reliably detect radiated modes with the possible exception of modes very close to cut-off.

  3. Node retraction during patterning of the urinary collecting duct system.

    PubMed

    Lindström, Nils O; Chang, C-Hong; Valerius, M Todd; Hohenstein, Peter; Davies, Jamie A

    2015-01-01

    This report presents a novel mechanism for remodelling a branched epithelial tree. The mouse renal collecting duct develops by growth and repeated branching of an initially unbranched ureteric bud: this mechanism initially produces an almost fractal form with young branches connected to the centre of the kidney via a sequence of nodes (branch points) distributed widely throughout the developing organ. The collecting ducts of a mature kidney have a different form: from the nephrons in the renal cortex, long, straight lengths of collecting duct run almost parallel to one another through the renal medulla, and open together to the renal pelvis. Here we present time-lapse studies of E11.5 kidneys growing in culture: after about 5 days, the collecting duct trees show evidence of 'node retraction', in which the node of a 'Y'-shaped branch moves downwards, shortening the stalk of the 'Y', lengthening its arms and narrowing their divergence angle so that the 'Y' becomes a 'V'. Computer simulation suggests that node retraction can transform a spread tree, like that of an early kidney, into one with long, almost-parallel medullary rays similar to those seen in a mature real kidney. PMID:25292187

  4. Annular linear induction pump with an externally supported duct

    DOEpatents

    Craig, Edwin R.; Semken, Robert S.

    1979-01-01

    Several embodiments of an annular linear induction pump for pumping liquid metals are disclosed having the features of generally one pass flow of the liquid metal through the pump and an increased efficiency resulting from the use of thin duct walls to enclose the stator. The stator components of this pump are removable for repair and replacement.

  5. Perturbations From Ducts on the Modes of Acoustic Thermometers

    PubMed Central

    Gillis, K. A.; Lin, H.; Moldover, M. R.

    2009-01-01

    We examine the perturbations of the modes of an acoustic thermometer caused by circular ducts used either for gas flow or as acoustic waveguides coupled to remote transducers. We calculate the acoustic admittance of circular ducts using a model based on transmission line theory. The admittance is used to calculate the perturbations to the resonance frequencies and half-widths of the modes of spherical and cylindrical acoustic resonators as functions of the duct’s radius, length, and the locations of the transducers along the duct's length. To verify the model, we measured the complex acoustic admittances of a series of circular tubes as a function of length between 200 Hz and 10 kHz using a three-port acoustic coupler. The absolute magnitude of the specific acoustic admittance is approximately one. For a 1.4 mm inside-diameter, 1.4 m long tube, the root mean square difference between the measured and modeled specific admittances (both real and imaginary parts) over this frequency range was 0.018. We conclude by presenting design considerations for ducts connected to acoustic thermometers.

  6. Obstructive jaundice due to radiation-induced hepatic duct stricture

    SciTech Connect

    Chandrasekhara, K.L.; Iyer, S.K.

    1984-10-01

    A case of obstructive jaundice due to radiation-induced hepatic duct stricture is reported. The patient received postoperative radiation for left adrenal carcinoma, seven years prior to this admission. The sequelae of hepatobiliary radiation and their management are discussed briefly.

  7. Should You Have the Air Ducts in Your Home Cleaned?

    MedlinePlus

    ... heat exchangers) may improve the efficiency of your system, resulting in a longer operating life, as well as some energy and maintenance ... spraying or otherwise introducing these materials into the operating duct system may cause much of the material to be ...

  8. Design curves for circular and annular duct silencers

    NASA Technical Reports Server (NTRS)

    Watson, Willie R.; Ramakrishnan, R.

    1989-01-01

    Conventional models of sound propagation between porous walls (Scott, 1946) are adapted in order to calculate design curves for the lined circular and annular-duct silencers used in HVAC systems. The derivation of the governing equations is outlined, and results for two typical cases are presented graphically. Good agreement with published experimental data is demonstrated.

  9. 29. DETAIL OF OUTLET DUCTS FOR MST AIRCONDITIONING SYSTEM IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. DETAIL OF OUTLET DUCTS FOR MST AIR-CONDITIONING SYSTEM IN NORTHWEST CORNER OF SLC-3W MST STATION 70.5 (LOWEST PAYLOAD SERVICE STATION). NOTE RING ATTACHMENT FOR PERSONNEL SAFETY HARNESS IN LEFT FOREGROUND. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  10. Thyroglossal Duct Papillary Thyroid Carcinoma and Synchronous Lingual Thyroid Atypia

    PubMed Central

    Yoo, Timothy; Kim, Yohanan; Simental, Alfred; Inman, Jared C.

    2016-01-01

    Thyroglossal duct and lingual thyroid ectopic lesions are exceedingly rare synchronous findings. Papillary thyroid carcinoma of these ectopic thyroid sites is well understood but still a rare finding. This case points to some management nuances in regard to ectopic thyroid screening with imaging and also shows the effectiveness of minimally invasive transoral robotic surgery for lingual thyroid. PMID:27119036

  11. Models for gamma-ray holdup measurements at duct contact

    SciTech Connect

    Sheppard, G.A.; Russo, P.A.; Wenz, T.R.; Miller, M.C.; Piquette, E.C. ); Haas, F.X.; Glick, J.B.; Garrett, A.G. )

    1991-01-01

    The use of gamma-ray measurements to nondestructively assay special nuclear material holdup in DOE processing facilities has increased recently. A measurement approach that is relatively insensitive to deposit geometry involves withdrawing the detector from the holdup-bearing equipment far enough to validate an assumed point-, line-, or area-source deposit geometry. Because of facility constraints, these generalized geometry procedures are not always followed, and some ducts are measured at contact. Quantitative interpretation of contact measurements requires knowledge of the width of the deposit transverse to the duct axis. Rocky Flats personnel have introduced a method to obtain data from which this width can be deduced. It involves taking measurements in pairs, with the detector viewing the holdup deposit at contact from above and below the duct. The interpretation of the top and bottom measurements to give the deposit width at each location requires a model for the detector's response to radial source position and a model for the deposit geometry. We have derived a relationship between the top-to-bottom count rate ratio and the deposit width that approximates the detector response and models the deposit geometry as a uniform strip. The model was validated in controlled experiments that used thin foils of high-enriched uranium metal to simulate duct deposits. 4 refs., 5 figs., 1 tab.

  12. Pressure losses across multiple fittings in ventilation ducts.

    PubMed

    Ai, Z T; Mak, C M

    2013-01-01

    The accurate prediction of pressure losses across in-duct fittings is of significance in relation to the accurate sizing and good energy efficiency of air-delivery systems. Current design guides provide design methods and data for the prediction of pressure losses only for a single and isolated fitting. This study presents an investigation of pressure losses across multiple interactive in-duct fittings in a ventilation duct. A laboratory measurement of pressure losses across one fitting and multiple fittings in a ventilation duct is carried out. The pressure loss across multiple interactive fittings is lower than that across multiple similar individual fittings, while the percentage decrease is dependent on the configuration and combination of the fittings. This implies that the pressure loss across multiple closely mounted fittings calculated by summing the pressure losses across individual fittings, as provided in the ASHRAE handbook and the CIBSE guide, is overpredicted. The numerical prediction of the pressure losses across multiple fittings using the large-eddy simulation (LES) model shows good agreement with the measured data, suggesting that this model is a useful tool in ductwork design and can help to save experimental resources and improve experimental accuracy and reliability. PMID:24385871

  13. Aspect ratio effects in turbulent duct flows studied with DNS

    NASA Astrophysics Data System (ADS)

    Vinuesa, R.; Noorani, A.; Lozano-Durán, A.; Schlatter, P.; Fischer, P.; Nagib, H.

    2012-11-01

    Three-dimensional effects present in turbulent duct flows, i.e., side-wall boundary layers and secondary motions, are studied by means of direct numerical simulations (DNS). The spectral element code Nek5000, developed by Fischer et. al. (2008), is used to compute turbulent duct flows with aspect ratios 1 and 3 in streamwise-periodic boxes of length 25 h (long enough to capture the longest streamwise structures). The total number of grid points is 28 and 62 million respectively, and the inflow conditions were adjusted iteratively in order to keep the same bulk Reynolds number at the centerplane (Reb , c = 2800) in both cases. Spanwise variations in wall shear, mean-flow profiles and turbulence statistics were analyzed with aspect ratio, and also compared with the 2D channel. The simulations were started from a laminar duct profile, and transition to turbulence was triggered by means of trip-forcing in the wall-normal direction, applied at the two horizontal walls. In addition, we developed a convergence criterion aimed at assessing the necessary averaging time TA for converged statistics. We find that econdary motions present in duct flows require longer averaging times and the total shear-stress profile is not necessarily linear.

  14. 16. FOREGROUND (LEFT TO RIGHT) EXHAUST AND INTAKE DUCTS. SOUTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. FOREGROUND (LEFT TO RIGHT) EXHAUST AND INTAKE DUCTS. SOUTH SIDE AND WEST FRONT OF LAUNCH CONTROL SUPPORT BUILDING IN BACKGROUND. VIEW TO NORTH. - Minuteman III ICBM Launch Control Facility November-1, 1.5 miles North of New Raymer & State Highway 14, New Raymer, Weld County, CO

  15. Node retraction during patterning of the urinary collecting duct system

    PubMed Central

    Lindström, Nils O; Chang, C-Hong; Valerius, M Todd; Hohenstein, Peter; Davies, Jamie A

    2015-01-01

    This report presents a novel mechanism for remodelling a branched epithelial tree. The mouse renal collecting duct develops by growth and repeated branching of an initially unbranched ureteric bud: this mechanism initially produces an almost fractal form with young branches connected to the centre of the kidney via a sequence of nodes (branch points) distributed widely throughout the developing organ. The collecting ducts of a mature kidney have a different form: from the nephrons in the renal cortex, long, straight lengths of collecting duct run almost parallel to one another through the renal medulla, and open together to the renal pelvis. Here we present time-lapse studies of E11.5 kidneys growing in culture: after about 5 days, the collecting duct trees show evidence of ‘node retraction’, in which the node of a ‘Y’-shaped branch moves downwards, shortening the stalk of the ‘Y’, lengthening its arms and narrowing their divergence angle so that the ‘Y’ becomes a ‘V’. Computer simulation suggests that node retraction can transform a spread tree, like that of an early kidney, into one with long, almost-parallel medullary rays similar to those seen in a mature real kidney. PMID:25292187

  16. Thoracoscopic Pericardial Window Creation and Thoracic Duct Ligation in Neonates

    PubMed Central

    Ouzounian, Steven P.; Napoleon, Lori; Permut, Lester C.; Golombek, Sergio G.

    2003-01-01

    Objective: We describe 2 newborn infants with persistent pericardial effusion treated with thoracoscopic pericardial window and thoracic duct ligation. Methods: Patient 1 was a premature female newborn who presented with severe cardiac anomalies, including dextrocardia. She was treated with pulmonary artery banding and pacemaker placement for complete cardiac block. Postoperatively, she developed pericarditis with persistent symptomatic pericardial effusion. She did not improve despite pericardial drain placement. She was treated with a thoracoscopic pericardial window. Patient 2 was a newborn male who presented with cardiac tamponade secondary to congenital chylopericardium. He did not respond to pericardial drain placement or medical management with fasting, total parenteral nutrition, and octreotide. He was treated with thoracoscopic pericardial window and thoracic duct ligation. Results: Patient 1 improved rapidly. The pericardial effusion disappeared. The chest tube was removed 5 days following surgery. She died 6 weeks later of a cardiac arrhythmia secondary to pacemaker failure. The pericardial effusion had resolved. Patient 2 responded to the pericardial window and thoracic duct ligation. He was discharged 10 days following the procedure. Conclusions: Thoracoscopy provides an excellent approach to the pericardium. Pericardial windows and biopsy can be safely performed with this approach. The thoracic duct can be easily identified and ligated even in small babies. Recovery can be fast with minimal postoperative discomfort. Cosmetic results are excellent and length of hospitalization is minimized. PMID:14626403

  17. Porokeratotic eccrine ostial and dermal duct nevus - revisited.

    PubMed

    Bhunia, Deblina; Ghosh, Shouvik; Rudra, Olympia; Biswas, Surajit Kumar

    2014-09-01

    We hereby report a rare case of a 14-year-old girl presenting with asymptomatic pitted papules over the flexor aspect of her right 4th and 5th digits. This was histopathologically proven to be porokeratotic eccrine ostial and dermal duct nevus (PEODDN). PMID:25244169

  18. 27. DUCT LINES AND HOLES TO BE LEFT IN TRANSFORMER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. DUCT LINES AND HOLES TO BE LEFT IN TRANSFORMER ROOM AND GALLERY, MENTONE, MAR. 13, 1904. R.S. MASSON, CONSULTING ELECTRICAL ENGINEER, SAN FRANCISCO AND LOS ANGELES. SCE drawing no. 52319. - Santa Ana River Hydroelectric System, SAR-3 Powerhouse, San Bernardino National Forest, Redlands, San Bernardino County, CA

  19. An unusually large destructive nasopalatine duct cyst: a case report.

    PubMed

    Perumal, Colin Jerome

    2013-03-01

    A case of an unusually large expansile nasopalatine duct cyst (NPDC) causing extensive destruction of the hard palate with involvement of the nasal cavity, perforation of the alveolar process and mucosa of the maxilla by pressure of the maxillary anterior teeth is being presented. PMID:24431822

  20. Pressure Losses across Multiple Fittings in Ventilation Ducts

    PubMed Central

    Ai, Z. T.; Mak, C. M.

    2013-01-01

    The accurate prediction of pressure losses across in-duct fittings is of significance in relation to the accurate sizing and good energy efficiency of air-delivery systems. Current design guides provide design methods and data for the prediction of pressure losses only for a single and isolated fitting. This study presents an investigation of pressure losses across multiple interactive in-duct fittings in a ventilation duct. A laboratory measurement of pressure losses across one fitting and multiple fittings in a ventilation duct is carried out. The pressure loss across multiple interactive fittings is lower than that across multiple similar individual fittings, while the percentage decrease is dependent on the configuration and combination of the fittings. This implies that the pressure loss across multiple closely mounted fittings calculated by summing the pressure losses across individual fittings, as provided in the ASHRAE handbook and the CIBSE guide, is overpredicted. The numerical prediction of the pressure losses across multiple fittings using the large-eddy simulation (LES) model shows good agreement with the measured data, suggesting that this model is a useful tool in ductwork design and can help to save experimental resources and improve experimental accuracy and reliability. PMID:24385871

  1. Numerical techniques in linear duct acoustics, 1980-81 update

    NASA Technical Reports Server (NTRS)

    Baumeister, K. J.

    1981-01-01

    A review is presented covering finite element and finite difference analysis of small amplitude (linear) sound propagation in straight and variable area ducts. This review stresses the new work performed during the 1980-1981 time frame, although a brief discussion of earlier work is also included. Emphasis is placed on the latest state of the art in numerical techniques.

  2. Imaging of the pancreatic duct by linear endoscopic ultrasound

    PubMed Central

    Sharma, Malay; Rai, Praveer; Rameshbabu, Chittapuram Srinivasan; Arya, Shalini

    2015-01-01

    The current gold standard investigation for anatomic exploration of the pancreatic duct (PD) is endoscopic retrograde cholangiopancreatography. Magnetic resonance cholangiopancreatography is a noninvasive method for exploration of the PD. A comprehensive evaluation of the course of PD and its branches has not been described by endoscopic ultrasound (EUS). In this article, we describe the techniques of imaging of PD using linear EUS. PMID:26374577

  3. Evaporation duct refractivity profile from satellite meteorological data

    NASA Astrophysics Data System (ADS)

    Levadnyi, Iu.; Ivanov, V.; Shalyapin, V.

    The refractivity profile is initial data for the microwave propagation prediction models Evaporation duct height is usually used to characterize refractivity profile in the surface layer over sea The evaporation duct height is calculated using bulk measurement of air temperature wind speed humidity pressure at some level and sea surface temperature Four prevailing models LKB Liu-Katsaros-Businger RSHMU Russian State Hydro-Meteorological University optimized by us ECMWF European Center for Medium range Weather Forecast and COARE Coupled Ocean-Atmosphere Response Experiment were examined The results of computation using above mentioned models were compared with the direct refractometric measurements All measurements meteorological and refractometric were made by us during two marine expeditions First expedition was in the Atlantic ocean from March to May in latitude 22 circ-32° North and longitude 52 circ-65° West 29 measurements Second one was in the Indian ocean from December to February in latitude 0 circ-15° North and longitude 55 circ-80° East 94 measurements The approximation by least square-root method was carried out to compare the direct measurements of evaporation duct height with the results of computations The minimum square-root error is obtained for LKB model 2 59m for negative air-sea temperature difference 2 42m maximum - for ECMWF model 2 72m All models overestimate low evaporation duct heights and underestimate - high values This effect is least of all define in RSHMU

  4. Low-noise flow valve for air ducts

    NASA Technical Reports Server (NTRS)

    Gallo, E. A.

    1970-01-01

    Valve assembly controls air flow from feeder into main duct, with minimum of turbulence, friction, pressure differential, and noise. Valve consists of damper, deflector, and spring. Streamlining of damper and deflector merges flow smoothly, while spring keeps damper and deflector in contact and eliminates valve chatter and damping vibrations.

  5. Clear cell carcinoid tumor of the distal common bile duct

    PubMed Central

    Todoroki, Takeshi; Sano, Takaaki; Yamada, Shuji; Hirahara, Nobutsune; Toda, Naotaka; Tsukada, Katsuhiko; Motojima, Ryuji; Motojima, Teiji

    2007-01-01

    Background Carcinoid tumors rarely arise in the extrahepatic bile duct and can be difficult to distinguish from carcinoma. There are no reports of clear cell carcinoid (CCC) tumors in the distal bile duct (DBD) to the best of our knowledge. Herein, we report a CCC tumor in the DBD and review the literature concerning extrahepatic bile duct carcinoid tumors. Case presentation A 73-old man presented with fever and occult obstructive jaundice. Ultrasonography, computed tomography (CT) and magnetic resonance cholangiopancreaticography (MRCP) demonstrated a nodular tumor projection in the DBD without regional lymph node swelling. Under suspicion of carcinoma, we resected the head of the pancreas along with 2nd portion duodenectomy and a lymph node dissection. The surgical specimen showed a golden yellow polypoid tumor in the DBD (0.8 × 0.6 × 0.5 cm in size). The lesion was composed of clear polygonal cells arranged in nests and a trabecular pattern. The tumor invaded through the wall into the fibromuscular layer. Immunohistochemical stains showed that neoplastic cells were positive for neuron-specific enolase (NSE), chromogranin A, synaptophysin, and pancreatic polypeptide and negative for inhibin, keratin, CD56, serotonin, gastrin and somatostatin. The postoperative course was uneventful and he is living well without relapse 12 months after surgery. Conclusion Given the preoperative difficulty in differentiating carcinoid from carcinoma, the pancreaticoduodenectomy is an appropriate treatment choice for carcinoid tumors located within the intra-pancreatic bile duct. PMID:17227590

  6. Congenital dilatation of the intrahepatic bile ducts with cholangiocarcinoma

    PubMed Central

    Gallagher, P. J.; Millis, R. R.; Mitchinson, M. J.

    1972-01-01

    Intrahepatic cholangiocarcinomas were found at necropsy in two previously reported cases of congenital dilatation of the intrahepatic bile ducts. The nature of the developmental abnormality is discussed and compared with other forms of biliary dilatation. Slow-flowing bile for many years probably leads to cholangiocarcinoma. Images PMID:4343747

  7. Robotic assisted Roux-en-Y hepaticojejunostomy in a post-cholecystectomy type E2 bile duct injury

    PubMed Central

    Prasad, Arun; De, Sudipto; Mishra, Purak; Tiwari, Abhishek

    2015-01-01

    Roux-en-Y hepaticojejunostomy anastomosis is the treatment of choice for common hepatic duct injury type E2. It has been performed laparoscopically with the advancement of laparoscopic skill. Recently, a telemanipulative robotic surgical system was introduced, providing laparoscopic instruments with wrist-arm technology and 3-dimensional visualization of the operative field. We present a case of 36-year-old female patient who had undergone elective cholecystectomy 2 mo ago for gall stones and had a common bile duct injury during surgery. As the stricture was old and complete it could not be tackled endoscopically. We did a laparoscopic assisted adhesiolysis followed by robotic Roux-en-Y hepaticojejunostomy. No intraoperative complications or technical problems were encountered. Postoperative period was uneventful and she was discharged on the 4th postoperative day. At follow-up, she is doing well without evidence of jaundice or cholangitis. This is the first reported case of robotic hepaticojejunostomy following common bile duct injury. The hybrid technique gives the patient benefit of laparoscopic adhesiolysis and robotic suturing. PMID:25684934

  8. Extracorporeal abdominal massage may help prevent recurrent bile duct stones after endoscopic sphincterotomy

    PubMed Central

    Uchida, Naohito; Hamaya, Sae; Tatsuta, Miwa; Nakatsu, Toshiaki

    2016-01-01

    Background and study aims: Endoscopic sphincterotomy (EST) is effective, but recurrent bile duct stones are a common late complication. Because there are still no effective therapies for preventing this complication, some patients have experienced bile duct stone recurrence many times. We describe herein a method of abdominal massage to treat patients with prior cholecystectomy who have experienced recurrence of bile duct stones. PMID:27540575

  9. Cooling air recycling for gas turbine transition duct end frame and related method

    DOEpatents

    Cromer, Robert Harold; Bechtel, William Theodore; Sutcu, Maz

    2002-01-01

    A method of cooling a transition duct end frame in a gas turbine includes the steps of a) directing cooling air into the end frame from a region external of the transition duct and the impingement cooling sleeve; and b) redirecting the cooling air from the end frame into the annulus between the transition duct and the impingement cooling sleeve.

  10. Sertraline-Associated Cholestasis and Ductopenia Consistent with Vanishing Bile Duct Syndrome.

    PubMed

    Conrad, Máire A; Cui, Jiawei; Lin, Henry C

    2016-02-01

    An adolescent with depression treated with sertraline developed cholestasis and bile duct paucity, which resolved with medication discontinuation. Vanishing bile duct syndrome is an acquired destruction of interlobular bile ducts. This type of drug-induced liver injury has been associated with other medications and requires practitioners' awareness of potential hepatotoxicity. PMID:26597434

  11. Modified External Dacryocystorhinostomy in Primary Acquired Nasolacrimal Duct Obstruction

    PubMed Central

    Sharma, Ashok K.; Sharma, Rajni

    2015-01-01

    Background Epiphora secondary to acquired nasolacrimal duct obstruction is a common ophthalmic problem in adults requiring surgical management. External dacryocystorhinostomy (DCR) is a reliable but difficult surgical technique for the treatment of nasolacrimal duct obstruction. Purpose To evaluate the success rate and complications of modified external DCR in patients with primary acquired nasolacrimal duct obstruction. Materials and Methods This hospital based prospective interventional study included 56 patients with primary acquired nasolacrimal duct obstruction. Diagnosis of nasolacrimal duct obstruction was made through irrigation of the nasolacrimal drainage system. All patients were operated by modified technique of external DCR with anastomosis of the anterior lacrimal and nasal mucosal flaps only, whereas posterior mucosal flaps were excised. Patients were followed up for a period of 6 months. During the follow up, success rate and complications if any were recorded. Success was defined objectively by a patent lacrimal passage on irrigation and subjectively by the absence of watering or discharge. Results The mean age of the study population was 39.23 ± 10.66 years, and 78.6% of patients were females (male to female ratio 1:3.7). The average operation time was 36.48 ± 4.72 minutes. Objective and subjective success rates were 92.9% and 89.3%, respectively after a follow up period of 6 months. Intraoperatively, haemorrhage occurred in 3 patients (5.3%) and laceration of the nasal mucosa in 4 patients (7.1%). Postoperative complications included significant lid swelling and periorbital ecchymosis in 3 patients (5.3%), epistaxis in 2 patients (3.6%) and hypertrophic scar in 2 patients (3.6%). Conclusion These results suggest that modified external DCR with anterior flaps anastomosis only is a simple, safe, less time consuming surgical technique that is easy to perform, and the outcome is comparable to conventional DCR. PMID:26557549

  12. Effect of discharge duct geometry on centrifugal fan performance and noise emission

    NASA Astrophysics Data System (ADS)

    Nelson, David A.; Butrymowicz, William; Thomas, Christopher

    2005-09-01

    Non-ideal inlet and discharge duct geometries can cause significant changes to both the aerodynamic performance (``fan curve'') and specific sound power emission of a fan. A proper understanding of actual installed performance, as well as a good estimate of the system backpressure curve, is critical to achieving flow and acoustic goals as well as other criteria such as power consumption, mass and volume. To this end a battery of ISO 10302 tests was performed on a blower assembly which supports the Advanced Animal Habitat, being developed by ORBITEC for deployment on the International Space Station. The blower assembly consists of (4) identical centrifugal fans that, amongst themselves and across two prototypes, incorporated several discharge geometries. The inlet geometries were identical in all cases. Thus by comparing the dimensionless pressure-flow and noise emission characteristics across the cases, significant insight into the nature and potential magnitude of these effects is gained.

  13. Clinical aspects of nonsurgical percutaneous transhepatic bile drainage in obstructive lesions of the extrahepatic bile ducts.

    PubMed Central

    Hansson, J A; Hoevels, J; Simert, G; Tylén, U; Vang, J

    1979-01-01

    Percutaneous transhepatic cholangiography (PTC) with subsequent external bile drainage by nonsurgically established percutaneous transhepatic intubation of bile ducts was performed in 105 patients with obstructive jaundice. Recovery of liver function and improvement in the patients' general condition prior to radical or palliative surgery, nonsurgical palliation in advanced cases of malignancy as well as relief of postoperative leakage from a biliodigestive anastomosis are the indications for the bile drainage technique used in the present study. Clinical aspects such as optimal period of preoperative drainage, frequency of catheter dislodgement, and rate of complications such as cholangitis, bile leakage to the abdominal cavity and risk for peritoneal hemorrhage are discussed. Two deaths occurred within this series. PMID:758865

  14. Early T Stage Salivary Duct Carcinoma: Outcomes and Implications for Patient Counseling

    PubMed Central

    Schmitt, Nicole C.; Sharma, Arun; Gilbert, Mark R.; Kim, Seungwon

    2016-01-01

    Salivary duct carcinoma (SDC) is a rare salivary malignancy that often presents at advanced stage. Outcomes of low T stage patients with SDC have not been previously examined in detail. We queried our institution’s cancer database and identified 28 patients with SDC in situ or T1/T2 SDC. A retrospective chart review was performed, followed by comparison of clinicopathologic features with N stage, disease-free survival, and overall survival. Patients tended to be male, in their sixties, with a high incidence of regional metastases, as in prior reports. Five-year disease-free and overall survival were 49%. Median disease-free survival was 3.24 years, and overall survival was 4.65 years. Parotid location, vascular invasion, facial nerve sacrifice, and extracapsular extension were associated with worse survival. This study provides practical information for counseling of patients who undergo surgery for a parotid mass and are found to have this aggressive malignancy. PMID:26307577

  15. Acoustic imaging of a duct spinning mode by the use of an in-duct circular microphone array.

    PubMed

    Wei, Qingkai; Huang, Xun; Peers, Edward

    2013-06-01

    An imaging method of acoustic spinning modes propagating within a circular duct simply with surface pressure information is introduced in this paper. The proposed method is developed in a theoretical way and is demonstrated by a numerical simulation case. Nowadays, the measurements within a duct have to be conducted using in-duct microphone array, which is unable to provide information of complete acoustic solutions across the test section. The proposed method can estimate immeasurable information by forming a so-called observer. The fundamental idea behind the testing method was originally developed in control theory for ordinary differential equations. Spinning mode propagation, however, is formulated in partial differential equations. A finite difference technique is used to reduce the associated partial differential equations to a classical form in control. The observer method can thereafter be applied straightforwardly. The algorithm is recursive and, thus, could be operated in real-time. A numerical simulation for a straight circular duct is conducted. The acoustic solutions on the test section can be reconstructed with good agreement to analytical solutions. The results suggest the potential and applications of the proposed method. PMID:23742352

  16. Experiments measuring particle deposition from fully developed turbulent flow in ventilation ducts

    SciTech Connect

    Sippola, Mark R.; Nazaroff, William W.

    2003-08-01

    Particle deposition in ventilation ducts influences particle exposures of building occupants and may lead to a variety of indoor air quality concerns. Experiments have been performed in a laboratory to study the effects of particle size and air speed on deposition rates of particles from turbulent air flows in galvanized steel and internally insulated ducts with hydraulic diameters of 15.2 cm. The duct systems were constructed of materials typically found in commercial heating, ventilating and air conditioning (HVAC) systems. In the steel duct system, experiments with nominal particle sizes of 1, 3, 5, 9 and 16 {micro}m were conducted at each of three nominal air speeds: 2.2, 5.3 and 9.0 m/s. In the insulated duct system, deposition rates of particles with nominal sizes of 1, 3, 5, 8 and 13 {micro}m were measured at nominal air speeds of 2.2, 5.3 and 8.8 m/s. Fluorescent techniques were used to directly measure the deposition velocities of monodisperse fluorescent particles to duct surfaces (floor, wall and ceiling) at two straight duct sections where the turbulent flow profile was fully developed. In steel ducts, deposition rates were higher to the duct floor than to the wall, which were, in turn, greater than to the ceiling. In insulated ducts, deposition was nearly the same to the duct floor, wall and ceiling for a given particle size and air speed. Deposition to duct walls and ceilings was greatly enhanced in insulated ducts compared to steel ducts. Deposition velocities to each of the three duct surface orientations in both systems were found to increase with increasing particle size or air velocity over the ranges studied. Deposition rates measured in the current experiments were in general agreement with the limited observations of similar systems by previous researchers.

  17. Lhx1 is required in Müllerian duct epithelium for uterine development

    PubMed Central

    Huang, Cheng-Chiu; Orvis, Grant D.; Kwan, Kin Ming; Behringer, Richard R.

    2014-01-01

    The female reproductive tract organs of mammals, including the oviducts, uterus, cervix and upper vagina, are derived from the Müllerian ducts, a pair of epithelial tubes that form within the mesonephroi. The Müllerian ducts form in a rostral to caudal manner, guided by and dependent on the Wolffian ducts that have already formed. Experimental embryological studies indicate that caudal elongation of the Müllerian duct towards the urogenital sinus occurs in part by proliferation at the ductal tip. The molecular mechanisms that regulate the elongation of the Müllerian duct are currently unclear. Lhx1 encodes a LIM-homeodomain transcription factor that is essential for male and female reproductive tract development. Lhx1 is expressed in both the Wolffian and Müllerian ducts. Wolffian duct-specific knockout of Lhx1 results in degeneration of the Wolffian duct and consequently the non cell-autonomous loss of the Müllerian duct. To determine the role of Lhx1 specifically in the Müllerian duct epithelium, we performed a Müllerian duct-specific knockout study using Wnt7a-Cre mice. Loss of Lhx1 in the Müllerian duct epithelium led to a block in Müllerian duct elongation and uterine hypoplasia characterized by loss of the entire endometrium (luminal and glandular epithelium and stroma) and inner circular but not the outer longitudinal muscle layer. Time-lapse imaging and molecular analyses indicate that Lhx1 acts cell autonomously to maintain ductal progenitor cells for Müllerian duct elongation. These studies identify LHX1 as the first transcription factor that is essential in the Müllerian duct epithelial progenitor cells for female reproductive tract development. Furthermore, these genetic studies demonstrate the requirement of epithelial-mesenchymal interactions for uterine tissue compartment differentiation. PMID:24560999

  18. Design of power-plant installations pressure-loss characteristics of duct components

    NASA Technical Reports Server (NTRS)

    Henry, John R

    1944-01-01

    A correlation of what are believed to be the most reliable data available on duct components of aircraft power-plant installations is presented. The information is given in a convenient form and is offered as an aid in designing duct systems and, subject to certain qualifications, as a guide in estimating their performance. The design and performance data include those for straight ducts; simple bends of square, circular, and elliptical cross sections; compound bends; diverging and converging bends; vaned bends; diffusers; branch ducts; internal inlets; and an angular placement of heat exchangers. Examples are included to illustrate methods of applying these data in analyzing duct systems. (author)

  19. Papillary Carcinoma Within a Thyroglossal Duct Cyst in a 17-Year-Old Child.

    PubMed

    Cheon, Nam Ju; Lee, Young Man; Lee, Jun Ho; Han, Jong Kyu; Lee, Ji Hye

    2016-05-01

    Thyroglossal duct cyst is a frequent event; however, papillary carcinoma within a thyroglossal duct cyst is rare, particularly in children. A 17-year-old girl presented with an asymptomatic mid-submental mass for the last 2 months. The diagnosis of thyroglossal duct cyst was made based on physical examination and computed tomography finding. After performance of Sistrunk procedure, an incidental papillary carcinoma within the thyroglossal duct cyst was observed on pathology. We reviewed the pediatric cases of thyroglossal duct carcinoma, and then decided not to perform a concurrent thyroidectomy. We will continue close follow-up for future thyroid involvement. PMID:27054418

  20. Temporary Trans-jejunal Hepatic Duct Stenting in Roux-en-y Hepaticojejunostomy for Reconstruction of Iatrogenic Bile Duct Injuries

    PubMed Central

    Sadegh Fazeli, Mohammad; Kazemeini, Ali Reza; Jafarian, Ali; Bashashati, Mohammad; Keramati, Mohammad Reza

    2016-01-01

    Background Bile Duct Injuries (BDI) during cholecystectomy are now being recognized as major health problems. Objectives Herein, we present our experience with handling major BDIs and report long-term outcome of hepaticojejunostomies followed by trans-jejunal hepatic duct stenting performed to reconstruct extra-hepatic biliary tracts. Materials and Methods In this case series, we prospectively collected data of 22 patients, who underwent first time biliary reconstruction through Roux-en-y hepaticojejunostomy followed by hepatic duct stenting using a trans-jejunal bifurcated 6F tube drain. The long-term outcome was assessed and defined as excellent (asymptomatic, normal liver enzymes and bilirubin levels), good (asymptomatic, mild abnormality in liver enzyme and bilirubin levels), poor (symptomatic, abnormal liver enzymes and bilirubin level) and failure (requiring reoperation). Results A total of 22 patients including four males (18.1%) and 18 females (81.8%) were evaluated. The mean age was 42.71 (range: 23 - 74) years. Twelve patients had undergone open cholecystectomy (54.5%) and the rest had a history of laparoscopic cholecystectomy. The mean interval between the primary operation and reconstruction was 92.71 days. The mean follow-up period after biliary reconstruction was 42.33 (range: 1 - 96) months. No instance of anastomotic leakage or stenosis, biliary sepsis, thromboembolic event, or respiratory infection was noted in the long-term follow-up. The outcome was excellent in all patients. No case with poor or failure of result was noticed. Conclusions Although a devastating complication iatrogenic major bile duct injuries can be corrected surgically with a high rate of success. Temporary trans-jejunal stenting of the hepatic ducts can help in maintaining the integrity of anastomosis without stenosis or biliary sepsis. PMID:27626003

  1. Simultaneous Extensive Intraductal Papillary Neoplasm of the Bile Duct and Pancreas: A Very Rare Entity

    PubMed Central

    Luvira, Vor; Pugkhem, Ake; Tipwaratorn, Theerawee; Chamgramol, Yaovalux; Pairojkul, Chawalit; Bhudhisawasdi, Vajarabhongsa

    2016-01-01

    Intraductal papillary neoplasm of the bile duct (IPNB) is a specific type of bile duct tumor. It has been proposed that it could be the biliary counterpart of the intraductal papillary neoplasm of the pancreas (IPMN-P). This hypothesis is supported by the presence of simultaneous intraductal tumors of both the bile duct and pancreas. There have been five reports of patients with simultaneous IPNB and IPMN-P. In all of these cases, biliary involvement was limited to the intrahepatic and perihilar bile duct, which had characteristics similar to IPMN-P and usually had slow progression in nature. Herein, we present the first case of extensive intraductal neoplasm involving the extrahepatic bile duct, intrahepatic bile duct, and entire length of the pancreas with a poor outcome, even after being treated aggressively with radical surgery and adjuvant chemotherapy. Additionally, we summarize previous case reports of simultaneous intraductal lesions of the bile duct and pancreas. PMID:26925284

  2. Configuration Effects on Acoustic Performance of a Duct Liner

    NASA Technical Reports Server (NTRS)

    Gerhold, Carl H.; Brown, Martha C.; Jones, Michael G.; Nark, Douglas; Howerton, Brian M.

    2008-01-01

    Continued success in aircraft engine noise reduction necessitates ever more complete understanding of the effect that flow path geometry has on sound propagation in the engine. The Curved Duct Test Rig (CDTR) has been developed at NASA Langley Research Center to investigate sound propagation through a duct of comparable size (approximately the gap of GE90) and physical characteristics to the aft bypass duct of typical aircraft engines. The liner test section is designed to mimic the outer/inner walls of an engine exhaust bypass duct that has been unrolled circumferentially. Experiments to investigate the effect of curvature along the flow path on the acoustic performance of a test liner are performed in the CDTR and reported in this paper. Flow paths investigated include both straight and curved with offsets from the inlet to the discharge plane of and 1 duct width, respectively. The test liners are installed on the side walls of the liner test section. The liner samples are perforate over honeycomb core, which design is typical of liners installed in aircraft nacelles. In addition to fully treated side walls, combinations of treated and acoustically rigid walls are investigated. While curvature in the hard wall duct is found not to reduce the incident sound significantly, it does cause mode scattering. It is found that asymmetry of liner treatment causes scattering of the incident mode into less attenuated modes, which degrades the overall liner attenuation. It is also found that symmetry of liner treatment enhances liner performance by eliminating scattering into less attenuated modes. Comparisons of measured liner attenuation with numerical results predicted by an analytic model based on the parabolic approximation (CDUCT-LaRC) have also been made and are reported in this paper. The effect of curvature in the rigid wall configuration estimated by CDUCT-LaRC is similar to the observed results, and the mode scattering seen in the measurements also occurs in the

  3. Preneoplastic conditions underlying bile duct cancer

    PubMed Central

    Sibulesky, Lena; Nguyen, Justin; Patel, Tushar

    2012-01-01

    Background Malignancies arising from the biliary tract can arise from the epithelial lining of the biliary tract and surrounding tissues. Conditions that predispose to malignancy as well as preneoplastic changes in biliary tract epithelia have been identified. In this overview, we discuss preneoplastic conditions of the biliary tract and emphasize their clinical relevance. Results Chronic biliary tract inflammation predisposes to cancer in the biliary tract. Biliary tract carcinogenesis involves a multistep process as a consequence of chronic biliary epithelial injury or inflammation. Reminiscent of other gastrointestinal epithelial malignancies such as gastric, colon, and pancreatic cancer, biliary tract cancers may evolve via a multistep progression from epithelial hyperplasia and dysplasia to malignant transformation. The potential role of initiating cells is also becoming recognized. Conclusions In spite of improved risk factor recognition, and advances in diagnostic tools, the early diagnosis of pre-malignant or malignant biliary tract conditions is extremely challenging, and there is a paucity of evidence on which to base their management. As a result, the role of pre-emptive surgery remains largely undefined. PMID:22391777

  4. Flow Through a Rectangular-to-Semiannular Diffusing Transition Duct

    NASA Technical Reports Server (NTRS)

    Foster, Jeff; Wendt, Bruce J.; Reichert, Bruce A.; Okiishi, Theodore H.

    1997-01-01

    Rectangular-to-semiannular diffusing transition ducts are critical inlet components on supersonic airplanes having bifucated engine inlets. This paper documents measured details of the flow through a rectangular-to-semiannular transition duct having an expansion area ratio of 1.53. Three-dimensional velocity vectors and total pressures at the exit plane of the diffuser are presented. Surface oil-flow visualization and surface static pressure data are shown. The tests were conducted with an inlet Mach number of 0.786 and a Reynolds number based on the inlet centerline velocity and exit diameter of 3.2 x 10(exp 6). The measured data are compared with previously published computational results. The ability of vortex generators to reduce circumferential total pressure distortion is demonstrated.

  5. Refraction of acoustic duct waveguide modes by exhaust jets.

    NASA Technical Reports Server (NTRS)

    Mani, R.

    1973-01-01

    The refraction of acoustic duct waveguide modes emitted from the open end of a semiinfinite rectangular duct by a jet-like exhaust flow is studied theoretically. The problem is formulated as a Wiener-Hopf problem and is ultimately solved by an approximate method due to Carrier and Koiter. Continuity of transverse acoustic particle displacement and of acoustic pressure is assumed at the jet/still-air interface. The solution exhibits several features of the acoustics of moving media such as a source convection effect, zones of relative silence, and simple refraction. Plots of far-field directivity patterns are presented for several cases and show refraction effects to be important even at modest exhaust Mach numbers of order 0.3. Only subsonic exhaust Mach numbers are considered.

  6. Intrahepatic Duct Stones Harboring Ascariasis Ova: A Case Report.

    PubMed

    Lee, Chen-Fang; Lee, Wei-Chen; Wu, Ren-Chin; Chen, Tse-Ching

    2016-03-01

    Ascariasis lumbricoides is one of the most common helminthic infestations in humans. Despite the fact that the prevalence of ascariasis in developed countries has been decreasing, biliary ascariasis can cause serious complications, such as acute cholangitis, pancreatitis, and liver abscess. Here we presented a rare ascariasis-related complication-hepatolithiasis.A 60-year-old female patient had symptoms of recurrent cholangitis. Abdominal computed tomography scan revealed left intrahepatic duct stones with left liver lobe atrophy. Endoscopic retrograde cholangiopancreatography was performed, but the stones could not be removed due to left main intrahepatic duct stenosis. The patient was treated with left hemi-hepatectomy. Unexpectedly, Ascaris ova were found on the histopathological examination. She received antihelminthic therapy orally and was on regular follow-up without any complications.Our study indicates that clinicians should be aware of biliary ascariasis in patients with hepatolithiasis, though not living in endemic areas. PMID:27015193

  7. Transoral robotic resection of a lingual thyroglossal duct cyst.

    PubMed

    Kimple, Adam J; Eliades, Steven J; Richmon, Jeremy D

    2012-12-01

    Thyroglossal duct cysts (TGDCs) are epithelial rests of the thyroid gland left during embryologic descent from the tongue base. Thyroglossal duct cysts confined to the tongue base alone are even more unusual. We present a case of a 45-year-old woman who presented with complaints of sore throat, globus, and throat clearing for 10 years. On examination she was found to have a 2 × 1.5-cm cystic-appearing mass, left of midline in the vallecula. The patient had a transoral robotic resection of this vallecular cyst, which was subsequently found to be a lingual TGDC. We believe this is the first reported case of a TGDC that was successfully excised using a transoral robotic approach. PMID:25302082

  8. Transoral robotic resection of a lingual thyroglossal duct cyst

    PubMed Central

    Kimple, Adam J.; Eliades, Steven J.; Richmon, Jeremy D.

    2014-01-01

    Thyroglossal duct cysts (TGDCs) are epithelial rests of the thyroid gland left during embryologic descent from the tongue base. Thyroglossal duct cysts confined to the tongue base alone are even more unusual. We present a case of a 45-year-old woman who presented with complaints of sore throat, globus, and throat clearing for 10 years. On examination she was found to have a 2 × 1.5-cm cystic-appearing mass, left of midline in the vallecula. The patient had a transoral robotic resection of this vallecular cyst, which was subsequently found to be a lingual TGDC. We believe this is the first reported case of a TGDC that was successfully excised using a transoral robotic approach. PMID:25302082

  9. LABORATORY EVALUATION OF THE DELTA Q TEST FOR DUCT LEAKAGE

    SciTech Connect

    ANDREWS,J.W.

    2003-05-01

    Using a residential-size duct system in a controlled laboratory setting, the repeatability and accuracy of the Delta Q test for air leakage in residential duct systems have been measured. More than 100 Delta Q tests were performed. These were compared with results using fan pressurization and also with results of a procedure (Delta Q Plus) that uses leakage hole-size information to select the leakage pressures to be used in the Delta Q algorithm. The average error in supply or return leakage for the fan-pressurization test was 6.4% of system fan flow. For the Delta Q test it was 3.4% of fan flow, while for Delta Q Plus it was 1.9% of fan flow.

  10. Common Hepatic Duct Mixed Adenoneuroendocrine Carcinoma Masquerading as Cholangiocarcinoma.

    PubMed

    Priyanka Akhilesh, Sali; Kamal Sunder, Yadav; Chandralekha, Tampi; Samir, Parikh; Prasad Kashinath, Wagle

    2016-01-01

    Bile duct mixed adenoneuroendocrine carcinoma (MANEC) is a rare entity. It is defined as having mixed elements of both neuroendocrine tumors (NET) and an adenocarcinoma element, the lesser component forming at least 30% of the tumor. It is a subtype of neuroendocrine carcinoma (NEC) showing both gland-forming epithelial tumor cells and neuroendocrine cells. It is generally misdiagnosed as cholangiocarcinoma on imaging studies. The preoperative pathological workup from the endoscopic retrograde cholangiography brush cytology usually misses the NET/NEC component since it often lies deeper in the tumor. However, it is reported that it is the NEC component that defines the prognosis of the tumor; hence, it is vital to identify the NEC component. We present a rare case of common hepatic duct (CHD) MANEC that was preoperatively misdiagnosed as cholangiocarcinoma. PMID:27375908

  11. [Experience in thyroglossal duct pathology: clinical case series].

    PubMed

    Cieri, Patricio; Udaquiola, Julia E; Calello, Santiago E; Libero, Daniel H

    2016-10-01

    The thyroglossal duct cyst pathology represents the second cause of bening cervical anomalies in childhood. Diagnosis is mainly clinical. Sistrunk (1920) proposed a surgical technique that is still considered the gold standard for definitive treatment of this condition. A retrospective study was made including patients who underwent surgery for thyroglossal duct cyst pathology in our department between June 2008 and August 2015. In this period, we performed 54 procedures in 45 patients (39 primary cases). Median age was 4.7 years; 14/39 patients (31.1%) had pre-operative infection. All patients were studied with neck ultrasound. A Sistrunk's procedure was performed in all cases. The global recurrence rate was 17.8% (8/45). PMID:27606652

  12. Rupture of Right Hepatic Duct into Hydatid Cyst

    PubMed Central

    Laskou, Styliani; Papavramidis, Theodossis S.; Pliakos, Ioannis; Kotidis, Eustathios; Kesisoglou, Isaak; Papavramidis, Spiros T.

    2012-01-01

    Echinococcal disease can develop anywhere in the human body. The liver represents its most frequent location. Hepatic hydatid cysts may rupture into the biliary tract, thorax, peritoneum, viscera, digestive tract or skin. We report a rare case with rupture of the right hepatic duct into a hydatid cyst in a woman with known hydatid disease and choledocholithiasis. The increased intra-luminal pressure in the biliary tree caused the rupture into the adjacent hydatid cyst. The creation of the fistula between the right hepatic duct and the hydatid cyst decompressed the biliary tree, decreased the bilirubin levels and offered a temporary resolution of the obstructive jaundice. Rupture of a hydatid cyst into the biliary tree usually leads to biliary colic, cholangitis and jaundice. However, in case of obstructive jaundice due to choledocholithiasis, it is possible that the cyst may rupture by other way around while offering the patient a temporary relief from his symptoms. PMID:22876065

  13. Nasal endoscopy in the management of congenital nasolacrimal duct obstruction

    PubMed Central

    Al-Faky, Yasser H.

    2013-01-01

    Probing is a reliable surgical intervention for the management of congenital nasolacrimal duct obstruction (CNLDO). However, it is a blind procedure that carries the risk of false passage formation. Moreover, its success rate is variable, with unexplained causes of failure. Recent literature suggests the use of nasal endoscopic-assisted probing to minimize nasal mucosal trauma, decreases the chance of creating a false passage and provides the optimum management option of different congenital variants of nasolacrimal duct obstruction. Nasal endoscopic-assisted probing has more or less consistent success rates varied between 85% and 98% compared with probing success rates, which vary between 55% and 95% despite having almost the same age range. PMID:24526852

  14. Eosinophilic cholecystitis with common bile duct stricture: a rare disease.

    PubMed

    Mehanna, Daniel; Naseem, Zainab; Mustaev, Muslim

    2016-01-01

    Although the most common cause of cholecystitis is gallstones, other conditions may present as acute cholecystitis. We describe a case of eosinophilic cholecystitis with common bile duct stricture. A 36-year-old woman initially had generalised abdominal pain and peripheral eosinophilia. Diagnostic laparoscopy showed eosinophilic ascites and necrotic nodules on the posterior abdominal wall. She was treated with anthelminthics on presumption of toxacara infection based on borderline positivity of serological tests. She later presented with acute cholecystitis and had a cholecystectomy and choledocotomy. Day 9 T-tube cholangiogram showed irregular narrowing of the distal common bile duct. The patient's symptoms were improved with steroids and the T-tube was subsequently removed. PMID:27222280

  15. Early diagnosis of common bile duct obstruction using cholescintigraphy

    SciTech Connect

    Kaplun, L.; Weissmann, H.S.; Rosenblatt, R.R.; Freeman, L.M.

    1985-11-01

    The technetium Tc 99m-labeled iminodiacetic acid cholescintigram is an extremely accurate examination for detecting early obstruction of the common bile duct in acutely ill patients suspected of having acute cholecystitis or possible obstruction days to years after cholecystectomy. The examination accurately detected common bile duct obstruction in 63 of 65 patients in these two diagnostic categories. Sonographic evaluations in 43 of these patients failed to reveal ductal dilatation or other abnormality in 26 cases, and was nondiagnostic because of overlying bowel gas in two cases. The success of the radionuclide examination is attributed to its ability to detect functional impedance to bile flow hours to days before anatomic ductal dilatation occurs, and occasionally even before the alkaline phosphatase level and other liver chemistry values suggest the presence of an obstruction.

  16. Hysteroscopic treatment of Müllerian duct anomalies.

    PubMed

    DI Spiezio Sardo, Attilio; Spinelli, Marialuigia; DA Cunha Vieira, Mariana; Zizolfi, Brunella; Nappi, Carmine; Bifulco, Giuseppe

    2016-04-01

    Müllerian duct anomalies are a broad and complex spectrum of abnormalities that are often associated with infertility, obstetric complications as well as gynecological disorders among women of reproductive age. Operative hysteroscopy is the gold standard in the treatment of most of those anomalies amenable to surgical correction. The evidence to date shows an ongoing increase in the release of recommendations in favour of operative hysteroscopic treatment, in concert with the progressive refinement of hysteroscopic technologies and techniques. The aim of this paper was to describe and critically evaluate the role of the currently available hysteroscopic techniques for treating Müllerian duct anomalies, taking into account their indications, feasibility and efficacy as well as their impact on the reproductive outcome. Special attention will be paid to the most recently developed minimally invasive treatments for uterine and vaginal anomalies. PMID:26889788

  17. Sound power flux measurements in strongly exited ducts with flow.

    PubMed

    Holland, Keith R; Davies, Peter O A L; van der Walt, Danie C

    2002-12-01

    This contribution describes new robust procedures for the measurement of sound power flux at appropriate axial positions along a duct with flow, using pairs of flush wall mounted microphones, or pressure transducers. The technology includes the application of selective averaging, order tracking, and optimized sampling rate methods to identify the small fraction of the total fluctuating wave energy that is being propagated along the flow path in a reverberent, or highly reactive duct system. Such measurements can also be used to quantify the local acoustic characteristics that govern the generation, transfer, and propagation of wave energy in the system. Illustrative examples include the determination of the acoustic characteristics of individual silencing elements installed in IC engine intakes and exhausts both on the flow bench and during controlled acceleration or run down on a test bed, where the wave component spectral levels approached 170 dB. PMID:12509008

  18. Marginal turbulent magnetohydrodynamic flow in a square duct

    NASA Astrophysics Data System (ADS)

    Shatrov, Victor; Gerbeth, Gunter

    2010-08-01

    Direct numerical simulations using a high-order finite-difference method were performed of the turbulent flow in a straight square duct in a transverse magnetic field. Without magnetic field the turbulence can be maintained for values of the bulk Reynolds number above approximately Re=1077 [M. Uhlmann et al., "Marginally turbulent flow in a square duct," J. Fluid Mech. 588, 153 (2007)]. In the magnetohydrodynamic case this minimal value of the bulk Reynolds number increases with the Hartmann number. The flow is laminar at Re=3000 when the Hartmann number is larger than Ha=12.5 and the flow is turbulent for Ha≦12.0. The secondary mean flow structure at Re=3000 consists of eight vortices located mainly at the Hartmann walls.

  19. Common Hepatic Duct Mixed Adenoneuroendocrine Carcinoma Masquerading as Cholangiocarcinoma

    PubMed Central

    Priyanka Akhilesh, Sali; Kamal Sunder, Yadav; Chandralekha, Tampi; Samir, Parikh; Prasad Kashinath, Wagle

    2016-01-01

    Bile duct mixed adenoneuroendocrine carcinoma (MANEC) is a rare entity. It is defined as having mixed elements of both neuroendocrine tumors (NET) and an adenocarcinoma element, the lesser component forming at least 30% of the tumor. It is a subtype of neuroendocrine carcinoma (NEC) showing both gland-forming epithelial tumor cells and neuroendocrine cells. It is generally misdiagnosed as cholangiocarcinoma on imaging studies. The preoperative pathological workup from the endoscopic retrograde cholangiography brush cytology usually misses the NET/NEC component since it often lies deeper in the tumor. However, it is reported that it is the NEC component that defines the prognosis of the tumor; hence, it is vital to identify the NEC component. We present a rare case of common hepatic duct (CHD) MANEC that was preoperatively misdiagnosed as cholangiocarcinoma. PMID:27375908

  20. Iatrogenic Submandibular Duct Rupture Complicating Sialography: A Case Report

    PubMed Central

    Sharouny, Hadi; Omar, Rahmat Bin

    2014-01-01

    Introduction: Sialolithiasis is the most common disease of salivary glands. Sialography is particularly important for the assessment of the outflow tract and in diagnosing obstructive salivary gland lesions including calculi. Case Presentation: We report on a 38-year-old female with sialolithiasis whom had Wharton’s duct perforation, complicating the sialography. She was treated conservatively with a course of co-amoxiclav, oral prednisolone for three days and pain-killers. The patient was clinically well on follow-up reassessments at the end of the first week and three weeks post procedure. Conclusions: Perforation of salivary duct complicating the sialography is rare. Awareness of this potential complication and utilizing a good sialography technique need to be advocated amongst radiologists. Response to treatment by conservative management is preferred as illustrated in this case. PMID:25593739

  1. Surgical treatment for hepatocellular carcinoma with bile duct invasion

    PubMed Central

    Hu, Xu-guang; Mao, Wei; Hong, Sung Yeon; Kim, Bong-Wan; Xu, Wei-guang

    2016-01-01

    Purpose There is still some debate on surgical procedures for hepatocellular carcinoma (HCC) patients with bile duct tumor thrombi (BDTT, Ueda type 3 or 4). What is adequate extent of liver resection for curative treatment? Is extrahepatic bile duct resection mandatory for cure? The aim of this study is to answer these questions. Methods Between February 1994 and December 2012, 877 consecutive HCC patients underwent hepatic resection at Ajou University Hospital. Thirty HCC patients (3.4%) with BDTT (Ueda type 3 or 4) were retrospective reviewed in this study. Results In total, 20 patients enrolled in this study were divided into 2 groups: patients who underwent hemihepatectomy with extrahepatic bile duct resection (group 1, n = 10) and with only removal of BDTT (group 2, n = 10). The 1-, 3- and 5-year overall survival rates were 75.0%, 50.0%, and 27.8%, respectively. The 1-, 3-, and 5-year survival rates of group 1 were 100.0%, 80.0%, and 45.7%, and those of group 2 were 50.0%, 20.0%, and 10.0%, respectively (P = 0.014). The 1-, 3-, and 5-year recurrences free survival rates of group 1 were 90.0%, 70.0%, and 42.0%, and those of group 2 were 36.0%, 36.0%, and 0%, respectively (P = 0.014). Thrombectomy and infiltrative growth type (Ig) were found as independent prognostic factors for recurrence free survival by multivariate analysis. Thrombectomy, Ig, and high indocyanine green retention rate at 15 minutes were found as independent prognostic factors for overall survival by multivariate analysis. Conclusion We suggest that the appropriate surgical procedure for icteric HCC patients should be comprised of ipsilateral hemihepatectomy with caudate lobectomy and extrahepatic bile duct resection. PMID:26942157

  2. Propagation of spinning acoustic modes in partially choked converging ducts

    NASA Astrophysics Data System (ADS)

    Nayfeh, A. H.; Kelly, J. J.; Watson, L. T.

    1982-04-01

    A computer model based on the wave-envelope technique is used to study the propagation of spinning acoustic modes in converging hard-walled and lined circular ducts carrying near sonic mean flows. The results show that with increasing spinning mode number the intensification of the acoustic signal at the throat decreases for upstream propagation. The influence of the throat Mach number, frequency, boundary-layer thickness, and liner admittance on the propagation of spinning modes is considered.

  3. Atmospheric ducts can transport sound in two directions

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2014-07-01

    When conditions are right, temperature gradients and fast jets of wind can help to establish atmospheric ducts—pathways in the atmosphere that promote the propagation of low-frequency acoustic waves (infrasound)—across long distances. Atmospheric ducts are part of the basis behind over-the-horizon radar, the source of some particularly clear mirages, and a channel through which sounds can travel relatively unperturbed across vast distances.

  4. Monograph on propagation of sound waves in curved ducts

    NASA Technical Reports Server (NTRS)

    Rostafinski, Wojciech

    1991-01-01

    After reviewing and evaluating the existing material on sound propagation in curved ducts without flow, it seems strange that, except for Lord Rayleigh in 1878, no book on acoustics has treated the case of wave motion in bends. This monograph reviews the available analytical and experimental material, nearly 30 papers published on this subject so far, and concisely summarizes what has been learned about the motion of sound in hard-wall and acoustically lined cylindrical bends.

  5. Aldosterone Activates NF-κB in the Collecting Duct

    PubMed Central

    Leroy, Valérie; De Seigneux, Sophie; Agassiz, Victor; Hasler, Udo; Rafestin-Oblin, Marie-Edith; Vinciguerra, Manlio; Martin, Pierre-Yves; Féraille, Eric

    2009-01-01

    Besides its classical effects on salt homeostasis in renal epithelial cells, aldosterone promotes inflammation and fibrosis and modulates cell proliferation. The proinflammatory transcription factor NF-κB has been implicated in cell proliferation, apoptosis, and regulation of transepithelial sodium transport. The effect of aldosterone on the NF-κB pathway in principal cells of the cortical collecting duct, a major physiologic target of aldosterone, is unknown. Here, in both cultured cells and freshly isolated rat cortical collecting duct, aldosterone activated the canonical NF-κB signaling pathway, leading to increased expression of several NF-κB–targeted genes (IκBα, plasminogen activator inhibitor 1, monocyte chemoattractant protein 1, IL-1β, and IL-6). Small interfering RNA–mediated knockdown of the serum and glucocorticoid-inducible kinase SGK1, a gene induced early in the response to aldosterone, but not pharmacologic inhibition of extracellular signal–regulated kinase and p38 kinase, attenuated aldosterone-induced NF-κB activation. Pharmacologic antagonism or knockdown of the mineralocorticoid receptor prevented aldosterone-induced NF-κB activity. In addition, activation of the glucocorticoid receptor inhibited the transactivation of NF-κB by aldosterone. In agreement with these in vitro findings, spironolactone prevented NF-κB–induced transcriptional activation observed in cortical collecting ducts of salt-restricted rats. In summary, aldosterone activates the canonical NF-κB pathway in principal cells of the cortical collecting duct by activating the mineralocorticoid receptor and by inducing SGK1. PMID:18987305

  6. Euler/Navier-Stokes Solvers Applied to Ducted Fan Configurations

    NASA Technical Reports Server (NTRS)

    Keith, Theo G., Jr.; Srivastava, Rakesh

    1997-01-01

    Due to noise considerations, ultra high bypass ducted fans have become a more viable design. These ducted fans typically consist of a rotor stage containing a wide chord fan and a stator stage. One of the concerns for this design is the classical flutter that keeps occurring in various unducted fan blade designs. These flutter are catastrophic and are to be avoided in the flight envelope of the engine. Some numerical investigations by Williams, Cho and Dalton, have suggested that a duct around a propeller makes it more unstable. This needs to be further investigated. In order to design an engine to safely perform a set of desired tasks, accurate information of the stresses on the blade during the entire cycle of blade motion is required. This requirement in turn demands that accurate knowledge of steady and unsteady blade loading be available. Aerodynamic solvers based on unsteady three-dimensional analysis will provide accurate and fast solutions and are best suited for aeroelastic analysis. The Euler solvers capture significant physics of the flowfield and are reasonably fast. An aerodynamic solver Ref. based on Euler equations had been developed under a separate grant from NASA Lewis in the past. Under the current grant, this solver has been modified to calculate the aeroelastic characteristics of unducted and ducted rotors. Even though, the aeroelastic solver based on three-dimensional Euler equations is computationally efficient, it is still very expensive to investigate the effects of multiple stages on the aeroelastic characteristics. In order to investigate the effects of multiple stages, a two-dimensional multi stage aeroelastic solver was also developed under this task, in collaboration with Dr. T. S. R. Reddy of the University of Toledo. Both of these solvers were applied to several test cases and validated against experimental data, where available.

  7. Theoretical models for duct acoustic propagation and radiation

    NASA Technical Reports Server (NTRS)

    Eversman, Walter

    1991-01-01

    The development of computational methods in acoustics has led to the introduction of analysis and design procedures which model the turbofan inlet as a coupled system, simultaneously modeling propagation and radiation in the presence of realistic internal and external flows. Such models are generally large, require substantial computer speed and capacity, and can be expected to be used in the final design stages, with the simpler models being used in the early design iterations. Emphasis is given to practical modeling methods that have been applied to the acoustical design problem in turbofan engines. The mathematical model is established and the simplest case of propagation in a duct with hard walls is solved to introduce concepts and terminologies. An extensive overview is given of methods for the calculation of attenuation in uniform ducts with uniform flow and with shear flow. Subsequent sections deal with numerical techniques which provide an integrated representation of duct propagation and near- and far-field radiation for realistic geometries and flight conditions.

  8. The importance of anatomical topography in nasolacrimal duct stenosis.

    PubMed

    Vojniković, Bozo; Bajek, Snjezana; Bajek, Goran; Braut, Tamara

    2014-12-01

    In our previous study the inclination of nasolacrimal canal in relation to Frankfurt horizontal plane has been analysed on 71 anatomically preparated human skulls by introducing the probe through canal. The results of that study showed that the alpha angle in the frontalplane was greater than 91 degrees in 27% of cases, i.e., nasolacrimal canals descend diverging in relation to the median plane and both probes are intersected on glabella. In 55% of cases, the alpha angle was less than 89 degrees and probes diverge on glabella, and in 18% of cases the canals were parallel to the median plane. In this study nasolacrimal ducts in patients were visualised with Omnipaque contrast that was injected with probe through the superior lacrimal punctum. Thereafter radiography was performed. These in vivo results confirm our previous results obtained on the skulls. Minimal individual variations of values of the angle were observed. These findings are very important inprobing of stenosis of nasolacrimal duct in infants, as the operator would not have to forcefully probe with rigid instrument through gentle infant nasolacrimal duct. Difficult and serious consequences for infants arise when directing the probe "via falsa" and that often happened in practice. The authors therefore suggest when using this old method ofprobing, that this "surgical" act should be performed with "soft" probe made of nylon or silver that is very pliable and does not lead to nasal or temporal rupture of the canal. PMID:25842741

  9. Examination of Duct Physiology in the Human Mammary Gland

    PubMed Central

    Mills, Dixie; Gomberawalla, Ameer; Gordon, Eva J.; Tondre, Julie; Nejad, Mitra; Nguyen, Tinh; Pogoda, Janice M.; Rao, Jianyu; Chatterton, Robert; Henning, Susanne; Love, Susan M.

    2016-01-01

    Background The human breast comprise several ductal systems, or lobes, which contain a small amount of fluid containing cells, hormones, proteins and metabolites. The complex physiology of these ducts is likely a contributing factor to the development of breast cancer, especially given that the vast majority of breast cancers begin in a single lobular unit. Methods We examined the levels of total protein, progesterone, estradiol, estrone sulfate, dehydroepiandrosterone sulfate, and macrophages in ductal fluid samples obtained from 3 ducts each in 78 women, sampled twice over a 6 month period. Samples were processed for both cytological and molecular analysis. Intraclass correlation coefficients and mixed models were utilized to identify significant data. Results We found that the levels of these ductal fluid components were generally uncorrelated among ducts within a single breast and over time, suggesting that each lobe within the breast has a distinct physiology. However, we also found that estradiol was more correlated in women who were nulliparous or produced nipple aspirate fluid. Conclusions Our results provide evidence that the microenvironment of any given lobular unit is unique to that individual unit, findings that may provide clues about the initiation and development of ductal carcinomas. PMID:27073976

  10. Combined forced and free convection in a curved duct

    NASA Technical Reports Server (NTRS)

    Yam, Clement G.; Dwyer, Harry A.

    1992-01-01

    The purpose of this study is to investigate the flow and heat transfer characteristics of a combined forced and free convection flow in a curved duct. Solutions are obtained by solving the low Mach number model of the Navier-Stokes equation using a control volume method. The finite-volume method was developed with the use of a predictor-corrector numerical scheme and some new variations of the classical projection method. Solutions indicated that the existence of a buoyancy force has changed the entire flow structure inside a curved duct. Reversed flow at both inner and outer bend is observed. For moderate Reynolds number, the upstream section of the duct was significantly influenced by the free convection processes. In general, heat transfer is strong at the inner bend of the beginning of the heated section and at the outer bend on the last half of the heated section. The maximum velocity location is strongly influenced by the combined effects of buoyancy and centrifugal forces. A strong buoyancy force can reduce the strength of the secondary flow where it plays an important role in mixing.

  11. Apoptosis in Early Salivary Gland Duct Morphogenesis and Lumen Formation.

    PubMed

    Teshima, T H N; Wells, K L; Lourenço, S V; Tucker, A S

    2016-03-01

    Salivary glands are essential for the maintenance of oral health by providing lubrication and antimicrobial protection to the mucosal and tooth surfaces. Saliva is modified and delivered to the oral cavity by a complex multifunctional ductal system. During development, these ducts form as solid tubes, which undergo cavitation to create lumens. Apoptosis has been suggested to play a role in this cavitation process along with changes in cell polarity. Here, we show that apoptosis occurs from the very earliest stages of mouse salivary gland development, much earlier than previously reported. Apoptotic cells were observed in the center of the first epithelial stalk at early-stage embryonic day 12.5 (E12.5) according to both TUNEL staining and cleaved caspase 3 immunofluorescence. The presumptive lumen space was highlighted by the colocalization of a predictive lumen marker, cytokeratin 7. At E14.5, as lumens start to form throughout the glands, apoptotic expression decreased while cytokeratin 7 remained positive. In vitro inhibition of all caspases in E12.5 and E13.5 salivary glands resulted in wider ducts, as compared with the controls, and a defect in lumen formation. In contrast, no such defect in lumen formation was observed at E14.5. Our data indicate that apoptosis is involved during early stages of gland formation (E12.5 onward) and appears important for shaping the forming ducts. PMID:26628486

  12. Cholecystokinin cholescintigraphic findings in the cystic duct syndrome

    SciTech Connect

    Fink-Bennett, D.; DeRidder, P.; Kolozsi, W.; Gordon, R.; Rapp, J.

    1985-10-01

    Fourteen patients with a cystic duct syndrome (CDS) underwent cholecystokinin (CCK) cholescintigraphy. All patients presented with persistent postprandial right upper quadrant pain and biliary colic. None of the patients had an abnormal oral cholecystography, gallbladder (GB) ultrasound exam or upper GI series. Each patient received 5 mCi of technetium-99m disofenin. When the GB maximally filled, 0.02 microgram/kg CCK was administered (3 min) intravenously. Background corrected gallbladder ejection fractions (GBEFs) were determined every 5 min X 4 by rationing the pre-CCK GB counts minus post-CCK GB counts to pre-CCK GB counts. GBEFs were: 12% (3 patients), 17% (2), 0%, 1.3%, 3%, 4%, 6%, 11%, 14%, 18.5%, and 22% (1 each). All patients underwent a surgical exploration and all had macro- or microscopically abnormal cystic ducts with (12 patients) or without (2 patients) concomitant chronic cholecystitis. No patient with a partially occluded cystic duct with or without concomitant chronic cholecystitis had an ejection fraction that exceeded 22%. In an appropriate clinical setting, a low EF response to CCK should alert the physician to the presence of either chronic acalculous cholecystitis, CDS, or the combination of both.

  13. Measure Guideline: Optimizing the Configuration of Flexible Duct Junction Boxes

    SciTech Connect

    Beach, R.; Burdick, A.

    2014-03-01

    This measure guideline offers additional recommendations to heating, ventilation, and air conditioning (HVAC) system designers for optimizing flexible duct, constant-volume HVAC systems using junction boxes within Air Conditioning Contractors of America (ACCA) Manual D guidance. IBACOS used computational fluid dynamics software to explore and develop guidance to better control the airflow effects of factors that may impact pressure losses within junction boxes among various design configurations. These recommendations can help to ensure that a system aligns more closely with the design and the occupants' comfort expectations. Specifically, the recommendations described herein show how to configure a rectangular box with four outlets, a triangular box with three outlets, metal wyes with two outlets, and multiple configurations for more than four outlets. Designers of HVAC systems, contractors who are fabricating junction boxes on site, and anyone using the ACCA Manual D process for sizing duct runs will find this measure guideline invaluable for more accurately minimizing pressure losses when using junction boxes with flexible ducts.

  14. Imaging of müllerian duct anomalies.

    PubMed

    Behr, Spencer C; Courtier, Jesse L; Qayyum, Aliya

    2012-10-01

    The müllerian ducts are paired embryologic structures that undergo fusion and resorption in utero to give rise to the uterus, fallopian tubes, cervix, and upper two-thirds of the vagina. Interruption of normal development of the müllerian ducts can result in formation of müllerian duct anomalies (MDAs). MDAs are a broad and complex spectrum of abnormalities that are often associated with primary amenorrhea, infertility, obstetric complications, and endometriosis. MDAs are commonly associated with renal and other anomalies; thus, identification of both kidneys is important. However, MDAs are not associated with ovarian anomalies. Hysterosalpingography (HSG) is routinely used in evaluation of infertility. Because a key component of MDA characterization is the external uterine fundal contour, HSG is limited for this purpose. Patients suspected of having an MDA are often initially referred for pelvic ultrasonography (US). Magnetic resonance (MR) imaging is typically reserved for complex or indeterminate cases. MR imaging is the imaging standard of reference because it is noninvasive, does not involve ionizing radiation, has multiplanar capability, allows excellent soft-tissue characterization, and permits a greater field of interrogation than does US. Use of MR imaging for evaluation of MDAs reduces the number of invasive procedures and related costs by guiding management decisions. PMID:23065173

  15. Foxa1 is essential for mammary duct formation.

    PubMed

    Liu, Yi; Zhao, Yongbing; Skerry, Benjamin; Wang, Xiao; Colin-Cassin, Christelle; Radisky, Derek C; Kaestner, Klaus H; Li, Zhaoyu

    2016-05-01

    The transcription factor forkhead box protein A1 (FOXA1) plays a critical role in the proliferation of human breast cancer cells, particularly estrogen receptor alpha (ERα)-positive luminal breast cancer cells. However, genetic studies of the requirement for Foxa1 in mammary tumor formation in mice have been hampered by the lack of a conditional gene ablation. We examined three mouse models of mammary-specific ablation of Foxa1 in ductal epithelial cells to identify the best system for complete and mammary-specific ablation of Foxa1. We found that MMTV-Cre and MMTV-rtTA;Tet-On-Cre led to partial deletion of Foxa1 and attenuated mammary duct formation, whereas Krt14-Cre led to complete ablation of Foxa1 and abolished mammary duct formation, in Foxa1(loxP/loxP) mice. These results demonstrate that Foxa1 is essential for mammary duct formation, and reveal a series of mouse models in which mammary expression of Foxa1 can be attenuated or completely blocked. Our study also suggests a potentially powerful model for complete ablation of Foxa1 in mammary epithelial cells using Krt14-driven Cre expression in an inducible manner, such as Krt14-rtTA;Tet-On-Cre. This model system will facilitate further in vivo functional studies of Foxa1 or other factors in mammary gland development and tumor formation and progression. genesis 54:277-285, 2016. © 2016 Wiley Periodicals, Inc. PMID:26919034

  16. Molecular basis of potassium channels in pancreatic duct epithelial cells

    PubMed Central

    Hayashi, Mikio; Novak, Ivana

    2013-01-01

    Potassium channels regulate excitability, epithelial ion transport, proliferation, and apoptosis. In pancreatic ducts, K+ channels hyperpolarize the membrane potential and provide the driving force for anion secretion. This review focuses on the molecular candidates of functional K+ channels in pancreatic duct cells, including KCNN4 (KCa3.1), KCNMA1 (KCa1.1), KCNQ1 (Kv7.1), KCNH2 (Kv11.1), KCNH5 (Kv10.2), KCNT1 (KCa4.1), KCNT2 (KCa4.2), and KCNK5 (K2P5.1). We will give an overview of K+ channels with respect to their electrophysiological and pharmacological characteristics and regulation, which we know from other cell types, preferably in epithelia, and, where known, their identification and functions in pancreatic ducts and in adenocarcinoma cells. We conclude by pointing out some outstanding questions and future directions in pancreatic K+ channel research with respect to the physiology of secretion and pancreatic pathologies, including pancreatitis, cystic fibrosis, and cancer, in which the dysregulation or altered expression of K+ channels may be of importance. PMID:23962792

  17. Advances in cholangiocyte immunobiology

    PubMed Central

    Syal, Gaurav; Fausther, Michel

    2012-01-01

    Cholangiocytes, or bile duct epithelia, were once thought to be the simple lining of the conduit system comprising the intra- and extrahepatic bile ducts. Growing experimental evidence demonstrated that cholangiocytes are in fact the first line of defense of the biliary system against foreign substances. Experimental advances in recent years have unveiled previously unknown roles of cholangiocytes in both innate and adaptive immune responses. Cholangiocytes can release inflammatory modulators in a regulated fashion. Moreover, they express specialized pattern-recognizing molecules that identify microbial components and activate intracellular signaling cascades leading to a variety of downstream responses. The cytokines secreted by cholangiocytes, in conjunction with the adhesion molecules expressed on their surface, play a role in recruitment, localization, and modulation of immune responses in the liver and biliary tract. Cholangiocyte survival and function is further modulated by cytokines and inflammatory mediators secreted by immune cells and cholangiocytes themselves. Because cholangiocytes act as professional APCs via expression of major histocompatibility complex antigens and secrete antimicrobial peptides in bile, their role in response to biliary infection is critical. Finally, because cholangiocytes release mediators critical to myofibroblastic differentiation of portal fibroblasts and hepatic stellate cells, cholangiocytes may be essential in the pathogenesis of biliary cirrhosis. PMID:22961800

  18. Advances in cholangiocyte immunobiology.

    PubMed

    Syal, Gaurav; Fausther, Michel; Dranoff, Jonathan A

    2012-11-15

    Cholangiocytes, or bile duct epithelia, were once thought to be the simple lining of the conduit system comprising the intra- and extrahepatic bile ducts. Growing experimental evidence demonstrated that cholangiocytes are in fact the first line of defense of the biliary system against foreign substances. Experimental advances in recent years have unveiled previously unknown roles of cholangiocytes in both innate and adaptive immune responses. Cholangiocytes can release inflammatory modulators in a regulated fashion. Moreover, they express specialized pattern-recognizing molecules that identify microbial components and activate intracellular signaling cascades leading to a variety of downstream responses. The cytokines secreted by cholangiocytes, in conjunction with the adhesion molecules expressed on their surface, play a role in recruitment, localization, and modulation of immune responses in the liver and biliary tract. Cholangiocyte survival and function is further modulated by cytokines and inflammatory mediators secreted by immune cells and cholangiocytes themselves. Because cholangiocytes act as professional APCs via expression of major histocompatibility complex antigens and secrete antimicrobial peptides in bile, their role in response to biliary infection is critical. Finally, because cholangiocytes release mediators critical to myofibroblastic differentiation of portal fibroblasts and hepatic stellate cells, cholangiocytes may be essential in the pathogenesis of biliary cirrhosis. PMID:22961800

  19. Sound Radiation from a Supersonic Jet Passing Through a Partially Open Exhaust Duct

    NASA Technical Reports Server (NTRS)

    Kandula, Max

    2011-01-01

    The radiation of sound from a perfectly expanded Mach 2.5 cold supersonic jet of 25.4 mm exit diameter flowing through a partially open rigid-walled duct with an upstream i-deflector has been studied experimentally. In the experiments, the nozzle is mounted vertically, with the nozzle exit plane at a height of 73 jet diameters above ground level. Relative to the nozzle exit plane (NEP), the location of the duct inlet is varied at 10, 5, and -1 jet diameters. Far-field sound pressure levels were obtained at 54 jet diameters above ground with the aid of acoustic sensors equally spaced around a circular arc of radius equal to 80 jet diameters from the jet axis. Data on the jet acoustic field for the partially open duct were obtained and compared with those with a free jet and with a closed duct. The results suggest that for the partially open duct the overall sound pressure level (OASPL) decreases as the distance between the NEP and the duct inlet plane decreases, while the opposite trend is observed for the closed duct. It is also concluded that the observed peak frequency in the partially open duct increases above the free jet value as the angle from the duct axis is increased, and as the duct inlet plane becomes closer to the NEP.

  20. Effect of Ducting on Radio Occultation Measurements: An Assessment Based on High-Resolution Radiosonde Soundings

    NASA Technical Reports Server (NTRS)

    Ao, C. O

    2007-01-01

    Recent studies have shown that the presence of elevated ducts in the lower atmosphere has an adverse effect on the inversion of GPS radio occultation data. The problem arises because the microwave refractivity within and below an elevated duct is no longer uniquely determined by the bending angle profile. Applying Abel inversion without a priori knowledge of the duct will introduce a negative bias in the retrieved refractivity profile within and below the duct. In this work, high vertical resolution radiosonde data are used to give a quantitative assessment of the characteristics and effects of ducts, including their frequency of occurrences, heights, and thicknesses at different latitudes and seasons. The negative bias from the Abel-retrieved refractivity profiles resulting from these ducts is also computed. The results give a strong indication that ducting in the lower troposphere is a frequent phenomenon over the tropics and midlatitudes. The ducts are shown to be predominantly caused by sharp changes in the vertical structure of water vapor. The majority of the ducts are found to be below 2 km, with a median duct layer thickness of about 100 m. The negative refractivity bias is shown to be largest below 2 km, with a median value of about 0.5-1% in the tropics and 0.2-0.5% in midlatitudes. The bias is about a factor of 2-3 smaller between 2 to 3 km and is negligible above 4 km.